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Sample records for p75 neurotrophin receptor-positive

  1. p75 neurotrophin receptor regulates energy balance in obesity

    PubMed Central

    Baeza-Raja, Bernat; Sachs, Benjamin D.; Li, Pingping; Christian, Frank; Vagena, Eirini; Davalos, Dimitrios; Le Moan, Natacha; Ryu, Jae Kyu; Sikorski, Shoana L.; Chan, Justin P.; Scadeng, Miriam; Taylor, Susan S.; Houslay, Miles D.; Baillie, George S.; Saltiel, Alan R.; Olefsky, Jerrold M.; Akassoglou, Katerina

    2015-01-01

    Summary Obesity and metabolic syndrome reflect the dysregulation of molecular pathways that control energy homeostasis. Here we show that upon high-fat diet (HFD), the p75 neurotrophin receptor (p75NTR) controls energy expenditure in obese mice. Despite no changes in food intake, p75NTR-null mice were protected from HFD-induced obesity and remained lean due to increased energy expenditure, without developing insulin resistance or liver steatosis. p75NTR directly interacts with the catalytic subunit of protein kinase A (PKA) and regulates cAMP signaling in adipocytes, leading to decreased lipolysis and thermogenesis. Adipocyte-specific depletion of p75NTR or transplantation of p75NTR-null white adipose tissue (WAT) into wild-type mice fed a HFD protected against weight gain and insulin resistance. Our results reveal that signaling from p75NTR to cAMP/PKA regulates energy balance and suggest that non-neuronal functions of neurotrophin receptor signaling could be a new target for treating obesity and the metabolic syndrome. PMID:26748707

  2. Neurotrophins inhibit major histocompatibility class II inducibility of microglia: Involvement of the p75 neurotrophin receptor

    PubMed Central

    Neumann, Harald; Misgeld, Thomas; Matsumuro, Kenji; Wekerle, Hartmut

    1998-01-01

    Major histocompatibility complex (MHC) molecules are rare in the healthy brain tissue, but are heavily expressed on microglial cells after inflammatory or neurodegenerative processes. We studied the conditions leading to the induction of MHC class II molecules in microglia by using explant cultures of neonatal rat hippocampus, a model of interacting neuronal networks. Interferon-γ (IFN-γ)-dependent MHC class II inducibility in microglia cells was very low, but strongly increased in the hippocampal slices after the blockade of neuronal activity by neurotoxins [tetrodotoxin (TTX), ω-conotoxin] or glutamate antagonists. None of these agents acted directly on isolated microglia cells. We found that neurotrophins modulate microglial MHC class II expression. MHC class II inducibility was enhanced by neutralization of neurotrophins produced locally within the cultured tissues and was inhibited by the addition of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), or neurotrophin-3 (NT3). NGF and, to a lower extent, NT3 acted directly on isolated microglia via the p75 neurotrophin receptor and inhibited MHC class II inducibility as shown by blockade of the p75 neurotrophin receptor with antibodies. Our data suggest that neurotrophins secreted by electrically active neurons control the antigen-presenting potential of microglia cells, and indicate that this effect is mediated partly via the p75 neurotrophin receptor. PMID:9576961

  3. The p75 neurotrophin receptor localization in blood-CSF barrier: expression in choroid plexus epithelium

    PubMed Central

    2011-01-01

    Background The presence of neurotrophins and their receptors Trk family has been reported in the choroid plexus. High levels of Nerve Growth Factor (NGF), Neurotrophin-4 (NT-4) and TrkB receptor were detected, while nothing was know about p75 neurotrophin receptor (p75NTR) in the choroid plexus epithelial cells. In neurons, p75NTR receptor has a dual function: promoting survival together with TrkA in response to NGF, and inducing apoptotic signaling through p75NTR. We postulated that p75NTR may also affect the survival pathways in the choroid plexus and also undergoes regulated proteolysis with metalloproteases. Results Here, we demonstrated the presence of p75NTR receptor in the choroid plexus epithelial cells. The p75NTR receptor would be involved in cell death mechanisms and in the damaged induced by amyloid beta (Aβ) in the choroid plexus and finally, we propose an essential role of p75NTR in the Aβ transcytosis through out choroid plexus barrier. Conclusions The presence analysis reveals the new localization of p75NTR in the choroid plexus and, the distribution mainly in the cytoplasm and cerebrospinal fluid (CSF) side of the epithelial cells. We propose that p75NTR receptor plays a role in the survival pathways and Aβ-induced cell death. These data suggest that p75NTR dysfunction play an important role in the pathogenesis of brain diseases. The importance and novelty of this expression expands a new role of p75NTR. PMID:21569322

  4. Characterization of p75 neurotrophin receptor expression in human dental pulp stem cells.

    PubMed

    Pan, Wenru; Kremer, Karlea L; Kaidonis, Xenia; Ludlow, Victoria E; Rogers, Mary-Louise; Xie, Jianling; Proud, Christopher G; Koblar, Simon A

    2016-10-01

    Human adult dental pulp stem cells (DPSC) are a heterogeneous stem cell population, which are able to differentiate down neural, chondrocyte, osteocyte and adipocyte lineages. We studied the expression pattern of p75 neurotrophin receptors (p75NTR), a marker of neural stem cells, within human DPSC populations from eight donors. p75NTR are expressed at low levels (<10%) in DPSC. Importantly, p75(+) DPSC represent higher expression levels of SOX1 (neural precursor cell marker), SOX2 (cell pluripotency marker) and nestin (neural stem cell marker) in comparison to p75(-) DPSC. Our results suggest that p75(+) hDPSC may denote a subpopulation with greater neurogenic potential. PMID:27469433

  5. p75 neurotrophin receptor is involved in proliferation of undifferentiated mouse embryonic stem cells

    SciTech Connect

    Moscatelli, Ilana; Pierantozzi, Enrico; Camaioni, Antonella; Siracusa, Gregorio; Campagnolo, Luisa

    2009-11-01

    Neurotrophins and their receptors are known to play a role in the proliferation and survival of many different cell types of neuronal and non-neuronal lineages. In addition, there is much evidence in the literature showing that the p75 neurotrophin receptor (p75{sup NTR}), alone or in association with members of the family of Trk receptors, is expressed in a wide variety of stem cells, although its role in such cells has not been completely elucidated. In the present work we have investigated the expression of p75{sup NTR} and Trks in totipotent and pluripotent cells, the mouse pre-implantation embryo and embryonic stem and germ cells (ES and EG cells). p75{sup NTR} and TrkA can be first detected in the blastocyst from which ES cell lines are derived. Mouse ES cells retain p75{sup NTR}/TrkA expression. Nerve growth factor is the only neurotrophin able to stimulate ES cell growth in culture, without affecting the expression of stem cell markers, alkaline phosphatase, Oct4 and Nanog. Such proliferation effect was blocked by antagonizing either p75{sup NTR} or TrkA. Interestingly, immunoreactivity to anti-p75{sup NTR} antibodies is lost upon ES cell differentiation. The expression pattern of neurotrophin receptors in murine ES cells differs from human ES cells, that only express TrkB and C, and do not respond to NGF. In this paper we also show that, while primordial germ cells (PGC) do not express p75{sup NTR}, when they are made to revert to an ES-like phenotype, becoming EG cells, expression of p75{sup NTR} is turned on.

  6. Regulation of low affinity neurotrophin receptor (p75NTR) by early growth response (Egr) transcriptional regulators

    PubMed Central

    Gao, Xiaoguang; Daugherty, Rebecca L.; Tourtellotte, Warren G.

    2007-01-01

    The low affinity neurotrophin receptor p75NTR is a multifunctional receptor with important roles in neurotrophin signaling, axon outgrowth, and oligodendroglia and neuron survival. It is transcriptionally regulated with spatial and temporal precision during nervous system development, injury and regeneration. Very little is known about how p75NTR expression is dynamically regulated but it is likely to influence how p75NTR signals in particular cellular contexts. Here, we identify the early growth response (Egr) transcriptional regulators, Egr1 and Egr3, as direct modulators of p75NTR gene expression. Egr1 and Egr3 bind and transactivate the p75NTR promoter in vitro and in vivo, using distinct response elements on the p75NTR promoter. Consistent with these results, p75NTR expression is greatly diminished in muscle spindle stretch receptors and in peripheral nerve Schwann cells in Egr gene deficient mice. Taken together, the results elucidate a novel mechanism whereby Egr proteins can directly modulate p75NTR expression and signaling in vivo. PMID:17916431

  7. A novel inhibitor of p75-neurotrophin receptor improves functional outcomes in two models of traumatic brain injury.

    PubMed

    Delbary-Gossart, Sandrine; Lee, Sangmi; Baroni, Marco; Lamarche, Isabelle; Arnone, Michele; Canolle, Benoit; Lin, Amity; Sacramento, Jeffrey; Salegio, Ernesto A; Castel, Marie-Noelle; Delesque-Touchard, Nathalie; Alam, Antoine; Laboudie, Patricia; Ferzaz, Badia; Savi, Pierre; Herbert, Jean-Marc; Manley, Geoffrey T; Ferguson, Adam R; Bresnahan, Jacqueline C; Bono, Françoise; Beattie, Michael S

    2016-06-01

    The p75 neurotrophin receptor is important in multiple physiological actions including neuronal survival and neurite outgrowth during development, and after central nervous system injury. We have discovered a novel piperazine-derived compound, EVT901, which interferes with p75 neurotrophin receptor oligomerization through direct interaction with the first cysteine-rich domain of the extracellular region. Using ligand binding assays with cysteine-rich domains-fused p75 neurotrophin receptor, we confirmed that EVT901 interferes with oligomerization of full-length p75 neurotrophin receptor in a dose-dependent manner. Here we report that EVT901 reduces binding of pro-nerve growth factor to p75 neurotrophin receptor, blocks pro-nerve growth factor induced apoptosis in cells expressing p75 neurotrophin receptor, and enhances neurite outgrowth in vitro Furthermore, we demonstrate that EVT901 abrogates p75 neurotrophin receptor signalling by other ligands, such as prion peptide and amyloid-β. To test the efficacy of EVT901 in vivo, we evaluated the outcome in two models of traumatic brain injury. We generated controlled cortical impacts in adult rats. Using unbiased stereological analysis, we found that EVT901 delivered intravenously daily for 1 week after injury, reduced lesion size, protected cortical neurons and oligodendrocytes, and had a positive effect on neurological function. After lateral fluid percussion injury in adult rats, oral treatment with EVT901 reduced neuronal death in the hippocampus and thalamus, reduced long-term cognitive deficits, and reduced the occurrence of post-traumatic seizure activity. Together, these studies provide a new reagent for altering p75 neurotrophin receptor actions after injury and suggest that EVT901 may be useful in treatment of central nervous system trauma and other neurological disorders where p75 neurotrophin receptor signalling is affected. PMID:27084575

  8. A novel inhibitor of p75-neurotrophin receptor improves functional outcomes in two models of traumatic brain injury

    PubMed Central

    Delbary-Gossart, Sandrine; Lee, Sangmi; Baroni, Marco; Lamarche, Isabelle; Arnone, Michele; Canolle, Benoit; Lin, Amity; Sacramento, Jeffrey; Salegio, Ernesto A.; Castel, Marie-Noelle; Delesque-Touchard, Nathalie; Alam, Antoine; Laboudie, Patricia; Ferzaz, Badia; Savi, Pierre; Herbert, Jean-Marc; Manley, Geoffrey T.; Ferguson, Adam R.; Bresnahan, Jacqueline C.

    2016-01-01

    The p75 neurotrophin receptor is important in multiple physiological actions including neuronal survival and neurite outgrowth during development, and after central nervous system injury. We have discovered a novel piperazine-derived compound, EVT901, which interferes with p75 neurotrophin receptor oligomerization through direct interaction with the first cysteine-rich domain of the extracellular region. Using ligand binding assays with cysteine-rich domains-fused p75 neurotrophin receptor, we confirmed that EVT901 interferes with oligomerization of full-length p75 neurotrophin receptor in a dose-dependent manner. Here we report that EVT901 reduces binding of pro-nerve growth factor to p75 neurotrophin receptor, blocks pro-nerve growth factor induced apoptosis in cells expressing p75 neurotrophin receptor, and enhances neurite outgrowth in vitro. Furthermore, we demonstrate that EVT901 abrogates p75 neurotrophin receptor signalling by other ligands, such as prion peptide and amyloid-β. To test the efficacy of EVT901 in vivo, we evaluated the outcome in two models of traumatic brain injury. We generated controlled cortical impacts in adult rats. Using unbiased stereological analysis, we found that EVT901 delivered intravenously daily for 1 week after injury, reduced lesion size, protected cortical neurons and oligodendrocytes, and had a positive effect on neurological function. After lateral fluid percussion injury in adult rats, oral treatment with EVT901 reduced neuronal death in the hippocampus and thalamus, reduced long-term cognitive deficits, and reduced the occurrence of post-traumatic seizure activity. Together, these studies provide a new reagent for altering p75 neurotrophin receptor actions after injury and suggest that EVT901 may be useful in treatment of central nervous system trauma and other neurological disorders where p75 neurotrophin receptor signalling is affected. PMID:27084575

  9. The neurotrophin receptor p75 mediates gp120-induced loss of synaptic spines in aging mice.

    PubMed

    Bachis, Alessia; Wenzel, Erin; Boelk, Allyssia; Becker, Jodi; Mocchetti, Italo

    2016-10-01

    Human immunodeficiency virus 1 and its envelope protein gp120 reduce synaptodendritic complexity. However, the mechanisms contributing to this pathological feature are still not understood. The proneurotrophin brain-derived neurotrophic factor promotes synaptic simplification through the activation of the p75 neurotrophin receptor (p75NTR). Here, we have used gp120 transgenic (gp120tg) mice to investigate whether p75NTR has a role in gp120-mediated neurotoxicity. Old (∼10 months) gp120tg mice exhibited an increase in proneurotrophin brain-derived neurotrophic factor levels in the hippocampus as well as a decrease in the number of dendritic spines when compared to age-matched wild type. These effects were not observed in 3- or 6-month-old mice. To test if the reduction in spine density and morphology is caused by the activation of p75NTR, we crossed gp120tg mice with p75NTR null mice. We found that deletion of only 1 copy of the p75NTR gene in gp120tg mice is sufficient to normalize the number of hippocampal spines, strongly suggesting that the neurotoxic effect of gp120 is mediated by p75NTR. These data indicate that p75NTR antagonists could provide an adjunct therapy against synaptic simplification caused by human immunodeficiency virus 1. PMID:27498053

  10. 3,4-methylenedioxyamphetamine upregulates p75 neurotrophin receptor protein expression in the rat brain.

    PubMed

    Wang, Chaomin; Peng, Zugui; Kuang, Weihong; Zheng, Hanyu; Long, Jiang; Wang, Xue

    2012-04-25

    The p75 neurotrophin receptor, which is a member of the tumor necrosis factor receptor superfamily, facilitates apoptosis during development and following central nervous system injury. Previous studies have shown that programmed cell death is likely involved in the neurotoxic effects of 3, 4-methylenedioxy-N-methylamphetamine (MDMA), because MDMA induces apoptosis of immortalized neurons through regulation of proteins belonging to the Bcl-2 family. In the present study, intraperitoneal injection of different doses of MDMA (20, 50, and 100 mg/kg) induced significant behavioral changes, such as increased excitability, increased activity, and irritability in rats. Moreover, changes exhibited dose-dependent adaptation. Following MDMA injection in rat brain tissue, the number of apoptotic cells dose-dependently increased and p75 neurotrophin receptor expression significantly increased in the prefrontal cortex, cerebellum, and hippocampus. These findings confirmed that MDMA induced neuronal apoptosis, and results suggested that this effect was related by upregulated protein expression of the p75 neurotrophin receptor. PMID:25722682

  11. The p75 Neurotrophin Receptor Can Induce Autophagy and Death of Cerebellar Purkinje Neurons

    PubMed Central

    Florez-McClure, Maria L.; Linseman, Daniel A.; Chu, Charleen T.; Barker, Phil A.; Bouchard, Ron J.; Le, Shoshona S.; Laessig, Tracey A.; Heidenreich, Kim A.

    2007-01-01

    The cellular mechanisms underlying Purkinje neuron death in various neurodegenerative disorders of the cerebellum are poorly understood. Here we investigate an in vitro model of cerebellar neuronal death. We report that cerebellar Purkinje neurons, deprived of trophic factors, die by a form of programmed cell death distinct from the apoptotic death of neighboring granule neurons. Purkinje neuron death was characterized by excessive autophagic–lysosomal vacuolation. Autophagy and death of Purkinje neurons were inhibited by nerve growth factor (NGF) and were activated by NGF-neutralizing antibodies. Although treatment with antisense oligonucleotides to the p75 neurotrophin receptor (p75ntr) decreased basal survival of cultured cerebellar neurons, p75ntr-antisense decreased autophagy and completely inhibited death of Purkinje neurons induced by trophic factor withdrawal. Moreover, adenoviral expression of a p75ntr mutant lacking the ligand-binding domain induced vacuolation and death of Purkinje neurons. These results suggest that p75ntr is required for Purkinje neuron survival in the presence of trophic support; however, during trophic factor withdrawal, p75ntr contributes to Purkinje neuron autophagy and death. The autophagic morphology resembles that found in neurodegenerative disorders, suggesting a potential role for this pathway in neurological disease. PMID:15140920

  12. Cerebellar Expression of the Neurotrophin Receptor p75 in Naked-Ataxia Mutant Mouse

    PubMed Central

    Rahimi Balaei, Maryam; Jiao, Xiaodan; Ashtari, Niloufar; Afsharinezhad, Pegah; Ghavami, Saeid; Marzban, Hassan

    2016-01-01

    Spontaneous mutation in the lysosomal acid phosphatase 2 (Acp2) mouse (nax—naked-ataxia mutant mouse) correlates with severe cerebellar defects including ataxia, reduced size and abnormal lobulation as well as Purkinje cell (Pc) degeneration. Loss of Pcs in the nax cerebellum is compartmentalized and harmonized to the classic pattern of gene expression of the cerebellum in the wild type mouse. Usually, degeneration starts in the anterior and posterior zones and continues to the central and nodular zones of cerebellum. Studies have suggested that the p75 neurotrophin receptor (NTR) plays a role in Pc degeneration; thus, in this study, we investigated the p75NTR pattern and protein expression in the cerebellum of the nax mutant mouse. Despite massive Pc degeneration that was observed in the nax mouse cerebellum, p75NTR pattern expression was similar to the HSP25 pattern in nax mice and comparable with wild type sibling cerebellum. In addition, immunoblot analysis of p75NTR protein expression did not show any significant difference between nax and wild type sibling (p > 0.5). In comparison with wild type counterparts, p75NTR pattern expression is aligned with the fundamental cytoarchitecture organization of the cerebellum and is unchanged in the nax mouse cerebellum despite the severe neurodevelopmental disorder accompanied with Pc degeneration. PMID:26784182

  13. Structural basis of death domain signaling in the p75 neurotrophin receptor

    PubMed Central

    Lin, Zhi; Tann, Jason Y; Goh, Eddy TH; Kelly, Claire; Lim, Kim Buay; Gao, Jian Fang; Ibanez, Carlos F

    2015-01-01

    Death domains (DDs) mediate assembly of oligomeric complexes for activation of downstream signaling pathways through incompletely understood mechanisms. Here we report structures of complexes formed by the DD of p75 neurotrophin receptor (p75NTR) with RhoGDI, for activation of the RhoA pathway, with caspase recruitment domain (CARD) of RIP2 kinase, for activation of the NF-kB pathway, and with itself, revealing how DD dimerization controls access of intracellular effectors to the receptor. RIP2 CARD and RhoGDI bind to p75NTR DD at partially overlapping epitopes with over 100-fold difference in affinity, revealing the mechanism by which RIP2 recruitment displaces RhoGDI upon ligand binding. The p75NTR DD forms non-covalent, low-affinity symmetric dimers in solution. The dimer interface overlaps with RIP2 CARD but not RhoGDI binding sites, supporting a model of receptor activation triggered by separation of DDs. These structures reveal how competitive protein-protein interactions orchestrate the hierarchical activation of downstream pathways in non-catalytic receptors. DOI: http://dx.doi.org/10.7554/eLife.11692.001 PMID:26646181

  14. Glioma invasion mediated by the p75 neurotrophin receptor (p75NTR/CD271) requires regulated interaction with PDLIM1

    PubMed Central

    Ahn, B Y; Saldanha-Gama, R F G; Rahn, J J; Hao, X; Zhang, J; Dang, N-H; Alshehri, M; Robbins, S M; Senger, D L

    2016-01-01

    The invasive nature of glioblastoma renders them incurable by current therapeutic interventions. Using a novel invasive human glioma model, we previously identified the neurotrophin receptor p75NTR (aka CD271) as a mediator of glioma invasion. Herein, we provide evidence that preventing phosphorylation of p75NTR on S303 by pharmacological inhibition of PKA, or by a mutational strategy (S303G), cripples p75NTR-mediated glioma invasion resulting in serine phosphorylation within the C-terminal PDZ-binding motif (SPV) of p75NTR. Consistent with this, deletion (ΔSPV) or mutation (SPM) of the PDZ motif results in abrogation of p75NTR-mediated invasion. Using a peptide-based strategy, we identified PDLIM1 as a novel signaling adaptor for p75NTR and provide the first evidence for a regulated interaction via S425 phosphorylation. Importantly, PDLIM1 was shown to interact with p75NTR in highly invasive patient-derived glioma stem cells/tumor-initiating cells and shRNA knockdown of PDLIM1 in vitro and in vivo results in complete ablation of p75NTR-mediated invasion. Collectively, these data demonstrate a requirement for a regulated interaction of p75NTR with PDLIM1 and suggest that targeting either the PDZ domain interactions and/or the phosphorylation of p75NTR by PKA could provide therapeutic strategies for patients with glioblastoma. PMID:26119933

  15. Glioma invasion mediated by the p75 neurotrophin receptor (p75(NTR)/CD271) requires regulated interaction with PDLIM1.

    PubMed

    Ahn, B Y; Saldanha-Gama, R F G; Rahn, J J; Hao, X; Zhang, J; Dang, N-H; Alshehri, M; Robbins, S M; Senger, D L

    2016-03-17

    The invasive nature of glioblastoma renders them incurable by current therapeutic interventions. Using a novel invasive human glioma model, we previously identified the neurotrophin receptor p75(NTR) (aka CD271) as a mediator of glioma invasion. Herein, we provide evidence that preventing phosphorylation of p75(NTR) on S303 by pharmacological inhibition of PKA, or by a mutational strategy (S303G), cripples p75(NTR)-mediated glioma invasion resulting in serine phosphorylation within the C-terminal PDZ-binding motif (SPV) of p75(NTR). Consistent with this, deletion (ΔSPV) or mutation (SPM) of the PDZ motif results in abrogation of p75(NTR)-mediated invasion. Using a peptide-based strategy, we identified PDLIM1 as a novel signaling adaptor for p75(NTR) and provide the first evidence for a regulated interaction via S425 phosphorylation. Importantly, PDLIM1 was shown to interact with p75(NTR) in highly invasive patient-derived glioma stem cells/tumor-initiating cells and shRNA knockdown of PDLIM1 in vitro and in vivo results in complete ablation of p75(NTR)-mediated invasion. Collectively, these data demonstrate a requirement for a regulated interaction of p75(NTR) with PDLIM1 and suggest that targeting either the PDZ domain interactions and/or the phosphorylation of p75(NTR) by PKA could provide therapeutic strategies for patients with glioblastoma. PMID:26119933

  16. Modulation of p75 neurotrophin receptor under hypoxic conditions induces migration and invasion of C6 glioma cells.

    PubMed

    Wang, Ting-Chung; Luo, Sheng-Jie; Lin, Chun-Liang; Chang, Pey-Jium; Chen, Miao-Fen

    2015-01-01

    p75 neurotrophin receptor (p75NTR) has been reported to play important roles in various cancer types. However, the exact mechanism of tumorigenesis involving p75NTR is unknown. In this study, we investigated the relationship between the expression of p75NTR in malignant glioma and the impact on tumor cell migration and invasion. p75NTR and hypoxia-inducible factor-1α (HIF-1α) expression was down-regulated by short-hairpin RNA and up-regulated with expression vectors. By immunohistochemical staining and Western blot analysis, we found that p75NTR was expressed in both human and rat malignant gliomas. Knockdown of p75NTR increased the expression of vimentin, vascular endothelial growth factor, Matrix metalloproteinase 9, and TWIST, and enhanced the invasion and migration abilities assessed by transwell assay in the C6 tumor cells. Inverse expressions of p75NTR and HIF-1α were detected in glioma cell lines under hypoxic conditions, while increased HIF-1α significantly downregulated the expression of p75NTR, suggesting a HIF-1α-p75NTR-EMT pathway that may regulate glioma cells invasion and migration. Downregulation of p75NTR increased phosphorylation of Src, focal adhesion kinase (FAK) and paxillin. Knockdown of p75NTR also dysregulated β-catenin-mediated cell junctions, and up-regulated the expressions of fibronectin and L1CAM in the cell-cell junctions, thus suggesting that p75NTR knockdown contributed to a more aggressive migration phenotype via FAK signaling pathway. Our studies suggested that modulation of p75NTR under hypoxic condition could enhance C6 cells migration and invasion by induction of EMT, and activation of the FAK pathway. The HIF-1α-p75NTR-EMT axis may play a central role in glioma tumorigenesis. PMID:25527128

  17. In vivo knockdown of basal forebrain p75 neurotrophin receptor stimulates choline acetyltransferase activity in the mature hippocampus.

    PubMed

    Barrett, Graham L; Naim, Timur; Trieu, Jennifer; Huang, Mengjie

    2016-05-01

    This study seeks to determine whether knockdown of basal forebrain p75 neurotrophin receptor (p75(NTR) ) expression elicits increased hippocampal choline acetyltransferase (ChAT) activity in mature animals. Antisense (AS) oligonucleotides (oligos) targeting p75(NTR) were infused into the medial septal area of mature rats continuously for 4 weeks. In all rats, the cannula outlet was placed equidistant between the left and the right sides of the vertical diagonal band of Broca. We tested phosphorothioate (PS), morpholino (Mo), and gapmer (mixed PS/RNA) oligos. Gapmer AS infusions of 7.5 and 22 μg/day decreased septal p75(NTR) mRNA by 34% and 48%, respectively. The same infusions increased hippocampal ChAT activity by 41% and 55%. Increased hippocampal ChAT activity correlated strongly with septal p75(NTR) downregulation in individual rats. Infusions of PS and Mo AS oligos did not downregulate p75(NTR) mRNA or stimulate ChAT activity. These results demonstrate that p75(NTR) can dynamically regulate hippocampal ChAT activity in the mature CNS. They also reveal the different efficacies of three diverse AS oligo chemistries when infused intracerebrally. Among the three types, gapmer oligos worked best. PMID:26864466

  18. TAp73 knockout mice show morphological and functional nervous system defects associated with loss of p75 neurotrophin receptor.

    PubMed

    Niklison-Chirou, Maria Victoria; Steinert, Joern R; Agostini, Massimiliano; Knight, Richard A; Dinsdale, David; Cattaneo, Antonio; Mak, Tak W; Melino, Gerry

    2013-11-19

    Total and N-terminal isoform selective p73 knockout mice show a variety of central nervous system defects. Here we show that TAp73 is a transcriptional activator of p75 neurotrophin receptor (p75(NTR)) and that p75(NTR) mRNA and protein levels are strongly reduced in the central and peripheral nervous systems of p73 knockout mice. In parallel, primary cortical neurons from p73 knockout mice showed a reduction in neurite outgrowth and in nerve growth factor-mediated neuronal differentiation, together with reduced miniature excitatory postsynaptic current frequencies and behavioral defects. p73 null mice also have impairments in the peripheral nervous system with reduced thermal sensitivity, axon number, and myelin thickness. At least some of these morphological and functional impairments in p73 null cells can be rescued by p75(NTR) re-expression. Together, these data demonstrate that loss of p75(NTR) contributes to the neurological phenotype of p73 knockout mice. PMID:24190996

  19. Proneurotrophin-3 promotes cell cycle withdrawal of developing cerebellar granule cell progenitors via the p75 neurotrophin receptor

    PubMed Central

    Zanin, Juan Pablo; Abercrombie, Elizabeth; Friedman, Wilma J

    2016-01-01

    Cerebellar granule cell progenitors (GCP) proliferate extensively in the external granule layer (EGL) of the developing cerebellum prior to differentiating and migrating. Mechanisms that regulate the appropriate timing of cell cycle withdrawal of these neuronal progenitors during brain development are not well defined. The p75 neurotrophin receptor (p75NTR) is highly expressed in the proliferating GCPs, but is downregulated once the cells leave the cell cycle. This receptor has primarily been characterized as a death receptor for its ability to induce neuronal apoptosis following injury. Here we demonstrate a novel function for p75NTR in regulating proper cell cycle exit of neuronal progenitors in the developing rat and mouse EGL, which is stimulated by proNT3. In the absence of p75NTR, GCPs continue to proliferate beyond their normal period, resulting in a larger cerebellum that persists into adulthood, with consequent motor deficits. DOI: http://dx.doi.org/10.7554/eLife.16654.001 PMID:27434667

  20. Immunization Against Specific Fragments of Neurotrophin p75 Receptor Protects Forebrain Cholinergic Neurons in the Olfactory Bulbectomized Mice

    PubMed Central

    Bobkova, Natalia; Vorobyov, Vasily; Medvinskaya, Natalia; Nesterova, Inna; Tatarnikova, Olga; Nekrasov, Pavel; Samokhin, Alexander; Deev, Alexander; Sengpiel, Frank; Koroev, Dmitry; Volpina, Olga

    2016-01-01

    Alzheimer’s disease (AD) is characterized by progressive cognitive impairment associated with marked cholinergic neuron loss and amyloid-β (Aβ) peptide accumulation in the brain. The cytotoxicity in AD is mediated, at least in part, by Aβ binding with the extracellular domain of the p75 neurotrophin receptor (p75NTR), localized predominantly in the membranes of acetylcholine-producing neurons in the basal forebrain. Hypothesizing that an open unstructured loop of p75NTR might be the effective site for Aβ binding, we have immunized both olfactory bulbectomized (OBX) and sham-operated (SO) mice (n = 82 and 49, respectively) with synthetic peptides, structurally similar to different parts of the loops, aiming to block them by specific antibodies. OBX-mice have been shown in previous studies, and confirmed in the present one, to be characterized by typical behavioral, morphological, and biochemical AD hallmarks, including cholinergic deficits in forebrain neurons. Immunization of OBX- or SO-mice with KLH conjugated fragments of p75NTR induced high titers of specific serum antibodies for each of nine chosen fragments. However, maximal protective effects on spatial memory, evaluated in a Morris water maze, and on activity of choline acetyltransferase in forebrain neurons, detected by immunoreactivity to specific antibodies, were revealed only for peptides with amino acid residue sequences of 155–164 and 167–176. We conclude that the approach based on immunological blockade of specific p75NTR sites, linked with the cytotoxicity, is a useful and effective tool for study of AD-associated mechanisms and for development of highly selective therapy of cholinergic malfunctioning in AD patients. PMID:27163825

  1. LINGO-1 Protein Interacts with the p75 Neurotrophin Receptor in Intracellular Membrane Compartments*

    PubMed Central

    Meabon, James S.; De Laat, Rian; Ieguchi, Katsuaki; Wiley, Jesse C.; Hudson, Mark P.; Bothwell, Mark

    2015-01-01

    Axon outgrowth inhibition in response to trauma is thought to be mediated via the binding of myelin-associated inhibitory factors (e.g. Nogo-66, myelin-associated glycoprotein, oligodendrocyte myelin glycoprotein, and myelin basic protein) to a putative tripartite LINGO-1·p75NTR·Nogo-66 receptor (NgR) complex at the cell surface. We found that endogenous LINGO-1 expression in neurons in the cortex and cerebellum is intracellular. Mutation or truncation of the highly conserved LINGO-1 C terminus altered this intracellular localization, causing poor intracellular retention and increased plasma membrane expression. p75NTR associated predominantly with natively expressed LINGO-1 containing immature N-glycans, characteristic of protein that has not completed trans-Golgi-mediated processing, whereas mutant forms of LINGO-1 with enhanced plasma membrane expression did not associate with p75NTR. Co-immunoprecipitation experiments demonstrated that LINGO-1 and NgR competed for binding to p75NTR in a manner that is difficult to reconcile with the existence of a LINGO-1·p75NTR·NgR ternary complex. These findings contradict models postulating functional LINGO-1·p75NTR·NgR complexes in the plasma membrane. PMID:25666623

  2. A cytoplasmic peptide of the neurotrophin receptor p75NTR: induction of apoptosis and NMR determined helical conformation.

    PubMed

    Hileman, M R; Chapman, B S; Rabizadeh, S; Krishnan, V V; Bredesen, D; Assa-Munt, N; Plesniak, L A

    1997-09-29

    The neurotrophin receptor (NTR) and tumor necrosis factor receptor family of receptors regulate apoptotic cell death during development and in adult tissues [Beutler and van Huffel, Science 264 (1994) 667-668]. We have examined a fragment of p75NTR from the carboxyl terminus of the receptor and a variant form of this peptide via NMR techniques and in vitro assays for apoptotic activity. The wild type peptide induces apoptosis and adopts a helical conformation oriented parallel to the surface of lipid micelles, whereas the variant form adopts a non-helical conformation in the presence of lipid and shows no activity. These experiments suggest a link between structure and function of the two peptides. PMID:9350985

  3. Novel p75 neurotrophin receptor ligand stabilizes neuronal calcium, preserves mitochondrial movement and protects against HIV associated neuropathogenesis.

    PubMed

    Meeker, Rick B; Poulton, Winona; Clary, Gillian; Schriver, Michael; Longo, Frank M

    2016-01-01

    Human immunodeficiency virus (HIV) rapidly penetrates into the brain and establishes a persistent infection of macrophages/microglia. Activation of these cells by HIV results in the secretion of soluble factors that destabilize neuronal calcium homeostasis, encourage oxidative stress and result in neural damage. This damage is thought to underlie the cognitive-motor dysfunction that develops in many HIV-infected patients. Studies have suggested that neurotrophins may protect neurons from the toxic effects of HIV-associated proteins. To better understand the pathogenic mechanisms and the neuroprotective potential of neurotrophin ligands, we evaluated neuronal damage, calcium homeostasis and mitochondrial functions after exposure of cultured rat neurons directly to HIV gp120 or to conditioned medium from human monocyte-derived macrophages treated with gp120. We then assessed the ability of a new non-peptide p75 neurotrophin receptor ligand, LM11A-31, to stabilize calcium homeostasis and prevent the development of pathology. Each toxic challenge resulted in a delayed accumulation of intracellular calcium coupled to a decrease in the rate of calcium clearance from the cell. The delayed calcium accumulation correlated with the development of focal dendritic swellings (beading), cytoskeletal damage and impaired movement of mitochondria. Addition of LM11A-31 to the cultures at nanomolar concentrations eliminated cell death, significantly reduced the pathology, suppressed the delayed accumulation of calcium and restored mitochondrial movements. The potent neuroprotection and the stabilization of calcium homeostasis indicate that LM11A-31 may have excellent potential for the treatment of HIV-associated neurodegeneration. PMID:26424436

  4. Neurotrophin, p75, and Trk Signaling Module in the Developing Nervous System of the Marine Annelid Platynereis dumerilii

    PubMed Central

    Lauri, Antonella; Bertucci, Paola; Arendt, Detlev

    2016-01-01

    In vertebrates, neurotrophic signaling plays an important role in neuronal development, neural circuit formation, and neuronal plasticity, but its evolutionary origin remains obscure. We found and validated nucleotide sequences encoding putative neurotrophic ligands (neurotrophin, NT) and receptors (Trk and p75) in two annelids, Platynereis dumerilii (Errantia) and Capitella teleta (Sedentaria, for which some sequences were found recently by Wilson, 2009). Predicted protein sequences and structures of Platynereis neurotrophic molecules reveal a high degree of conservation with the vertebrate counterparts; some amino acids signatures present in the annelid Trk sequences are absent in the basal chordate amphioxus, reflecting secondary loss in the cephalochordate lineage. In addition, expression analysis of NT, Trk, and p75 during Platynereis development by whole-mount mRNA in situ hybridization supports a role of these molecules in nervous system and circuit development. These annelid data corroborate the hypothesis that the neurotrophic signaling and its involvement in shaping neural networks predate the protostome-deuterostome split and were present in bilaterian ancestors. PMID:27069919

  5. Neurotrophin, p75, and Trk Signaling Module in the Developing Nervous System of the Marine Annelid Platynereis dumerilii.

    PubMed

    Lauri, Antonella; Bertucci, Paola; Arendt, Detlev

    2016-01-01

    In vertebrates, neurotrophic signaling plays an important role in neuronal development, neural circuit formation, and neuronal plasticity, but its evolutionary origin remains obscure. We found and validated nucleotide sequences encoding putative neurotrophic ligands (neurotrophin, NT) and receptors (Trk and p75) in two annelids, Platynereis dumerilii (Errantia) and Capitella teleta (Sedentaria, for which some sequences were found recently by Wilson, 2009). Predicted protein sequences and structures of Platynereis neurotrophic molecules reveal a high degree of conservation with the vertebrate counterparts; some amino acids signatures present in the annelid Trk sequences are absent in the basal chordate amphioxus, reflecting secondary loss in the cephalochordate lineage. In addition, expression analysis of NT, Trk, and p75 during Platynereis development by whole-mount mRNA in situ hybridization supports a role of these molecules in nervous system and circuit development. These annelid data corroborate the hypothesis that the neurotrophic signaling and its involvement in shaping neural networks predate the protostome-deuterostome split and were present in bilaterian ancestors. PMID:27069919

  6. The p75 neurotrophin receptor augments survival signaling in the striatum of pre-symptomatic Q175(WT/HD) mice.

    PubMed

    Wehner, A B; Milen, A M; Albin, R L; Pierchala, B A

    2016-06-01

    Huntington's disease (HD) is a dominantly inherited neurodegenerative disorder characterized by a constellation of motor, cognitive, and psychiatric features. Striatal medium spiny neurons, one of the most affected populations, are dependent on brain-derived neurotrophic factor (BDNF) anterogradely transported from the cortex for proper function and survival. Recent studies suggest both receptors for BDNF, TrkB and p75 neurotrophin receptor (p75), are improperly regulated in the striata of HD patients and mouse models of HD. While BDNF-TrkB signaling almost exclusively promotes survival and metabolic function, p75 signaling is able to induce survival or apoptosis depending on the available ligand and associated co-receptor. We investigated the role of p75 in the Q175 knock-in mouse model of HD by examining the levels and activation of downstream signaling molecules, and subsequently examining Hdh(+/Q175);p75(-/-) mice to determine if p75 represents a promising therapeutic target. In Hdh(+/Q175);p75(+/+) mice, we observed enhanced survival signaling as evidenced by an increase in phosphorylation and activation of Akt and the p65 subunit of NFκB in the striatum at 5months of age and an increase in XIAP expression compared to Hdh(+/+);p75(+/+) mice; this increase was lost in Hdh(+/Q175);p75(-/-) mice. Hdh(+/Q175);p75(-/-) mice also showed a decrease in Bcl-XL expression by immunoblotting compared to Hdh(+/Q175);p75(+/+) and Hdh(+/+);p75(+/+) littermates. Consistent with diminished survival signaling, DARPP-32 expression decreased both by immunoblotting and by immunohistochemistry in Hdh(+/Q175);p75(-/-) mice compared to Hdh(+/+);p75(+/+), Hdh(+/Q175);p75(+/+), and Hdh(+/+);p75(-/-) littermates. Additionally, striatal volume declined to a greater extent in Hdh(+/Q175);p75(-/-) when compared to Hdh(+/Q175);p75(+/+) littermates at 12months, indicating a more aggressive onset of degeneration. These data suggest that p75 signaling plays an early role in augmenting pro

  7. The neurotrophin receptor p75NTR triggers endothelial cell apoptosis and inhibits angiogenesis: implications for diabetes-induced impairment of reparative neovascularization

    PubMed Central

    Caporali, Andrea; Pani, Elisabetta; Horrevoets, Anton J. G.; Kraenkel, Nicolle; Oikawa, Atsuhiko; Sala-Newby, Graciela B.; Meloni, Marco; Cristofaro, Brunella; Graiani, Gallia; Leroyer, Aurelie; Boulanger, Chantal; Herman, Andrew; Spinetti, Gaia; Yoon, Sung Ok; Madeddu, Paolo; Emanueli, Costanza

    2009-01-01

    Diabetes compromises endothelial function and inhibits reparative neovascularization. The neurotrophin receptor p75NTR is scarcely present in healthy endothelial cells (EC), but diabetes induces p75NTR in capillary EC of ischemic limb muscles. Here, we show that forced p75NTR expression impairs survival, proliferation, migration, and adhesion capacities of EC and endothelial progenitor cells (EPC) and inhibits EC tube formation. In EC, p75NTR depresses the VEGF-A/Akt/eNOS/NO pathway and reduces VEGF-A, ITGB1, BIRC5, PTTG1, and VEZF1 mRNA levels. Moreover, both diabetes and p75NTR transfer down-regulate VEGF-A, ITGB1, and VEZF1 in adductor muscles. Forced p75NTR expression by ischemic limb muscles impairs post-ischemic neovascularization and blood flow recovery in normoglycemic mice. Conversely, p75NTR inhibition in diabetic muscles restores proper post-ischemic neovascularization and prevents apoptosis of muscular capillary EC and bone marrow-resident Sca-1+Lin- progenitor cells. Collectively, our data identify the anti-angiogenic action of p75NTR and suggests the therapeutic potential of p75NTR inhibition to combat diabetes-induced microvascular liabilities. PMID:18566344

  8. A HaloTag® method for assessing the retrograde axonal transport of the p75 neurotrophin receptor and other proteins in compartmented cultures of rat sympathetic neurons.

    PubMed

    Mok, Sue-Ann; Lund, Karen; Lapointe, Paul; Campenot, Robert B

    2013-03-30

    We have adapted HaloTag® (HT) technology for use in compartmented cultures of rat sympathetic neurons in order to provide a technique that can be broadly applied to studies of the retrograde transport of molecules that play roles in neurotrophin signaling. Transfected neurons expressing HT protein alone, HT protein fused to the p75 neurotrophin receptor (p75NTR) or HT protein fused to tubulin α-1B were maintained in compartmented cultures in which cell bodies and proximal axons of rat sympathetic neurons reside in proximal compartments and their distal axons extend into distal compartments. HT ligand containing a fluorescent tetramethylrhodamine (TMR) label was applied either in the distal compartments or the proximal compartments, and the transport of labeled proteins was assayed by gel fluorescence imaging and TMR immunoblot. HT protein expressed alone displayed little or no retrograde transport. HT protein fused to either the intracellular C-terminus or the extracellular N-terminus of p75NTR was retrogradely transported. The retrograde transport of p75NTR was augmented when the distal axons were provided with nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) or antibodies to BDNF. The anterograde transport of HT protein fused to the N-terminus of tubulin α-1B was also demonstrated. We conclude that retrograde transport of HT fusion proteins provides a powerful and novel approach in studies of axonal transport. PMID:23348044

  9. p75 neurotrophin receptor expression is a characteristic of the mitotically quiescent cancer stem cell population present in esophageal squamous cell carcinoma.

    PubMed

    Yamaguchi, Tetsuji; Okumura, Tomoyuki; Hirano, Katsuhisa; Watanabe, Toru; Nagata, Takuya; Shimada, Yutaka; Tsukada, Kazuhiro

    2016-05-01

    Mitotically quiescent cancer stem cells (CSC) are hypothesized to exhibit a more aggressive phenotype involving greater therapeutic resistance and metastasis. The aim of our study was to develop a method for identifying quiescent CSC in esophageal squamous cell carcinoma (ESCC) based on their expression of the p75 neurotrophin receptor (p75NTR) and other proposed CSC markers, such as CD44 and CD90. Double immunostaining of surgical ESCC specimens revealed that the mean Ki-67-labeling index of the p75NTR-positive cells was significantly lower than that of the p75NTR-negative cells. Real-time PCR analysis of sorted fractions of ESCC cell lines (KYSE cells) revealed that stem cell-related genes (Nanog, p63 and Bmi-1) and epithelial-mesenchymal transition (EMT)-related genes (N-cadherin and fibronectin) were expressed at significantly higher levels in the p75NTR-positive fractions than in the CD44-positive or CD90-positive fractions. In addition, the p75NTR-positive fractions exhibited significantly higher colony formation in vitro, significantly enhanced tumor formation in mice, and significantly greater chemoresistance against cisplatin (CDDP) than the CD44‑positive or CD90‑positive fractions. Furthermore, in both the cultured cells and those from the mouse xenograft tumors, the p75NTR‑positive/CD44-negative and p75NTR‑positive/CD90-negative KYSE cell fractions contained significantly higher proportions of mitotically quiescent cells. These results suggest that the mitotically quiescent CSC population in ESCC can be identified and isolated based on their p75NTR expression, providing researchers with a novel diagnostic and therapeutic target. PMID:26984177

  10. p75 neurotrophin receptor regulates tissue fibrosis through inhibition of plasminogen activation via a PDE4/cAMP/PKA pathway

    PubMed Central

    Sachs, Benjamin D.; Baillie, George S.; McCall, Julianne R.; Passino, Melissa A.; Schachtrup, Christian; Wallace, Derek A.; Dunlop, Allan J.; MacKenzie, Kirsty F.; Klussmann, Enno; Lynch, Martin J.; Sikorski, Shoana L.; Nuriel, Tal; Tsigelny, Igor; Zhang, Jin; Houslay, Miles D.; Chao, Moses V.; Akassoglou, Katerina

    2007-01-01

    Clearance of fibrin through proteolytic degradation is a critical step of matrix remodeling that contributes to tissue repair in a variety of pathological conditions, such as stroke, atherosclerosis, and pulmonary disease. However, the molecular mechanisms that regulate fibrin deposition are not known. Here, we report that the p75 neurotrophin receptor (p75NTR), a TNF receptor superfamily member up-regulated after tissue injury, blocks fibrinolysis by down-regulating the serine protease, tissue plasminogen activator (tPA), and up-regulating plasminogen activator inhibitor-1 (PAI-1). We have discovered a new mechanism in which phosphodiesterase PDE4A4/5 interacts with p75NTR to enhance cAMP degradation. The p75NTR-dependent down-regulation of cAMP results in a decrease in extracellular proteolytic activity. This mechanism is supported in vivo in p75NTR-deficient mice, which show increased proteolysis after sciatic nerve injury and lung fibrosis. Our results reveal a novel pathogenic mechanism by which p75NTR regulates degradation of cAMP and perpetuates scar formation after injury. PMID:17576803

  11. p75 Neurotrophin Receptor Signaling Activates Sterol Regulatory Element-binding Protein-2 in Hepatocyte Cells via p38 Mitogen-activated Protein Kinase and Caspase-3.

    PubMed

    Pham, Dan Duc; Do, Hai Thi; Bruelle, Céline; Kukkonen, Jyrki P; Eriksson, Ove; Mogollón, Isabel; Korhonen, Laura T; Arumäe, Urmas; Lindholm, Dan

    2016-05-13

    Nerve growth factor (NGF) influences the survival and differentiation of a specific population of neurons during development, but its role in non-neuronal cells has been less studied. We observed here that NGF and its pro-form, pro-NGF, are elevated in fatty livers from leptin-deficient mice compared with controls, concomitant with an increase in low density lipoprotein receptors (LDLRs). Stimulation of mouse primary hepatocytes with NGF or pro-NGF increased LDLR expression through the p75 neurotrophin receptor (p75NTR). Studies using Huh7 human hepatocyte cells showed that the neurotrophins activate the sterol regulatory element-binding protein-2 (SREBP2) that regulates genes involved in lipid metabolism. The mechanisms for this were related to stimulation of p38 mitogen-activated protein kinase (p38 MAPK) and activation of caspase-3 and SREBP2 cleavage following NGF and pro-NGF stimulations. Cell fractionation experiments showed that caspase-3 activity was increased particularly in the membrane fraction that harbors SREBP2 and caspase-2. Experiments showed further that caspase-2 interacts with pro-caspase-3 and that p38 MAPK reduced this interaction and caused caspase-3 activation. Because of the increased caspase-3 activity, the cells did not undergo cell death following p75NTR stimulation, possibly due to concomitant activation of nuclear factor-κB (NF-κB) pathway by the neurotrophins. These results identify a novel signaling pathway triggered by ligand-activated p75NTR that via p38 MAPK and caspase-3 mediate the activation of SREBP2. This pathway may regulate LDLRs and lipid uptake particularly after injury or during tissue inflammation accompanied by an increased production of growth factors, including NGF and pro-NGF. PMID:26984409

  12. Establishing a cellular FRET-based fluorescence plate reader assay to monitor proNGF-induced cross-linking of sortilin and the neurotrophin receptor p75NTR

    PubMed Central

    Skeldal, Sune; Kjaergaard, Maj M; Alwasel, Saleh; Nyengaard, Jens R

    2015-01-01

    Whereas the proform of the nerve growth factor (proNGF) is crucial for eliminating superfluous cells during neuronal development it also promotes apoptosis following brain trauma and neuronal injury. The apoptotic signal is elicited upon formation of a trimeric receptor complex also containing the vps10p domain receptor sortilin and the neurotrophin receptor p75NTR. However, proNGF-induced receptor complex formation has been difficult to directly assess other than by western blotting. We here describe a fluorescence resonance energy transfer (FRET) based fluorescence plate reader assay to monitor the interaction between fluorescently tagged sortilin and p75NTR in live cells. The method is based on a standard fluorescent plate reader found in many biochemical laboratories and the results are evaluated using a microscopy-based quantified sensitized acceptor emission FRET approach making use of a pair of FRET standard constructs. As a result, the effect of proNGF on the interaction between sortilin and p75NTR can be evaluated in live cells allowing for screening and selection of therapeutic compounds interfering with proNGF-induced cell death. PMID:26823987

  13. Establishing a cellular FRET-based fluorescence plate reader assay to monitor proNGF-induced cross-linking of sortilin and the neurotrophin receptor p75(NTR).

    PubMed

    Skeldal, Sune; Kjaergaard, Maj M; Alwasel, Saleh; Nyengaard, Jens R

    2015-01-01

    Whereas the proform of the nerve growth factor (proNGF) is crucial for eliminating superfluous cells during neuronal development it also promotes apoptosis following brain trauma and neuronal injury. The apoptotic signal is elicited upon formation of a trimeric receptor complex also containing the vps10p domain receptor sortilin and the neurotrophin receptor p75(NTR). However, proNGF-induced receptor complex formation has been difficult to directly assess other than by western blotting. We here describe a fluorescence resonance energy transfer (FRET) based fluorescence plate reader assay to monitor the interaction between fluorescently tagged sortilin and p75(NTR) in live cells. The method is based on a standard fluorescent plate reader found in many biochemical laboratories and the results are evaluated using a microscopy-based quantified sensitized acceptor emission FRET approach making use of a pair of FRET standard constructs. As a result, the effect of proNGF on the interaction between sortilin and p75(NTR) can be evaluated in live cells allowing for screening and selection of therapeutic compounds interfering with proNGF-induced cell death. PMID:26823987

  14. Effect of electro-acupuncture on ovarian expression of α (1)- and β (2)-adrenoceptors, and p75 neurotrophin receptors in rats with steroid-induced polycystic ovaries

    PubMed Central

    Manni, Luigi; Lundeberg, Thomas; Holmäng, Agneta; Aloe, Luigi; Stener-Victorin, Elisabet

    2005-01-01

    Background Estradiol valerate (EV)-induced polycystic ovaries (PCO) in rats is associated with an increase in ovarian sympathetic outflow. Low-frequency (2 Hz) electro-acupuncture (EA) has been shown to modulate sympathetic markers as well as ovarian blood flow as a reflex response via the ovarian sympathetic nerves, in rats with EV-induced PCO. Methods In the present study, we further tested the hypothesis that repeated 2 Hz EA treatments modulate ovarian sympathetic outflow in rats with PCO, induced by a single i.m. injection of EV, by investigating the mRNA expression, the amount and distribution of proteins of α1a-, α1b-, α1d-, and β2-adrenoceptors (ARs), as well as the low-affinity neurotrophin receptor (p75NTR). Results It was found that EV injection results in significantly higher mRNA expression of ovarian α1b- and α1d-AR in PCO rats compared to control rats. The p75NTR and β2-ARs mRNA expression were unchanged in the PCO ovary. Low-frequency EA resulted in a significantly lower expression of β2-ARs mRNA expression in PCO rats. The p75NTR mRNA was unaffected in both PCO and control rats. PCO ovaries displayed significantly higher amount of protein of α1a-, α1b- and α1d-ARs, and of p75NTR, compared to control rats, that were all counteracted by repeated low-frequency EA treatments, except for α1b-AR. Conclusion The present study shows that EA normalizes most of the EV-induced changes in ovarian ARs. Furthermore, EA was able to prevent the EV-induced up regulation of p75NTR, probably by normalizing the sympathetic ovarian response to NGF action. Our data indicate a possible role of EA in the regulation of ovarian responsiveness to sympathetic inputs and depict a possible complementary therapeutic approach to overcoming sympathetic-related anovulation in women with PCOS. PMID:15941472

  15. Alterations of p75 neurotrophin receptor and Myelin transcription factor 1 in the hippocampus of perinatal phencyclidine treated rats.

    PubMed

    Andrews, Jessica L; Newell, Kelly A; Matosin, Natalie; Huang, Xu-Feng; Fernandez-Enright, Francesca

    2015-12-01

    Postnatal administration of phencyclidine (PCP) in rodents causes major disturbances to neurological processes resulting in severe modifications to normal behavioral traits into adulthood. It is routinely used to model psychiatric disorders such as schizophrenia, producing many of the dysfunctional processes in the brain that are present in this devastating disorder, including elevated levels of apoptosis during neurodevelopment and disruptions to myelin and plasticity processes. Lingo-1 (or Leucine-rich repeat and immunoglobulin domain-containing protein) is responsible for negatively regulating neurite outgrowth and the myelination of axons. Recent findings using a postmortem human brain cohort showed that Lingo-1 signaling partners in the Nogo receptor (NgR)/p75/TNF receptor orphan Y (TROY) signaling complex, and downstream signaling partners With No Lysine (K) (WNK1) and Myelin transcription factor 1 (Myt1), play a significant part in schizophrenia pathophysiology. Here we have examined the implication of Lingo-1 and its signaling partners in a neurodevelopmental model of schizophrenia using PCP to determine if these pathways are altered in the hippocampus throughout different stages of neurodevelopment. Male Sprague-Dawley rats were injected subcutaneously with PCP (10mg/kg) or saline solution on postnatal days (PN) 7, 9, and 11. Rats (n=6/group) were sacrificed at PN12, 5weeks, or 14weeks. Relative expression levels of Lingo-1 signaling proteins were examined in the hippocampus of the treated rats. p75 and Myt1 were decreased (0.001≤p≤0.011) in the PCP treated rats at PN12. There were no significant changes in any of the tested proteins at 5weeks (p>0.05). At 14weeks, p75, TROY, and Myt1 were increased in the PCP treated rats (0.014≤p≤0.022). This is the first report of an alteration in Lingo-1 signaling proteins in the rat hippocampus, both directly after PCP treatment in early development and in adulthood. Based on our results, we propose that

  16. INHIBITION OF PAN NEUROTROPHIN RECEPTOR P75 ATTENUATES DIESEL PARTICULATE-INDUCED ENHANCEMENT OF ALLERGIC AIRWAY RESPONSES IN C57/BL6J MICE

    EPA Science Inventory

    Recent investigations have linked neurotrophins including nerve growth factor (NGF), neurotrophin-3 (NT-3), and brain-derived neurotrophic factor (BDNF) to allergic airways diseases. Antibody blockade of NGF attenuates airway resistance in allergic mice. Diesel exhaust particle...

  17. BLOCKADE OF TRKA OR P75 NEUROTROPHIN RECEPTORS ATTENUATES DIESEL PARTICULATE-INDUCED ENHANCEMENT OF ALLERGIC AIRWAYS RESPONSES IN BALB/C MICE

    EPA Science Inventory

    Neurotrophins, including nerve growth factor (NGF) partially mediate many features of allergic airways disease including airway resistance. Exposure to diesel exhaust particles (DEP) associated with the combustion of diesel fuel exacerbates allergic airways responses. We tested t...

  18. Recent advances in understanding neurotrophin signaling

    PubMed Central

    Bothwell, Mark

    2016-01-01

    The nerve growth factor family of growth factors, collectively known as neurotrophins, are evolutionarily ancient regulators with an enormous range of biological functions. Reflecting this long history and functional diversity, mechanisms for cellular responses to neurotrophins are exceptionally complex. Neurotrophins signal through p75 NTR, a member of the TNF receptor superfamily member, and through receptor tyrosine kinases (TrkA, TrkB, TrkC), often with opposite functional outcomes. The two classes of receptors are activated preferentially by proneurotrophins and mature processed neurotrophins, respectively. However, both receptor classes also possess neurotrophin-independent signaling functions. Signaling functions of p75 NTR and Trk receptors are each influenced by the other class of receptors. This review focuses on the mechanisms responsible for the functional interplay between the two neurotrophin receptor signaling systems. PMID:27540475

  19. Neurotrophin signalling pathways regulating neuronal apoptosis.

    PubMed

    Miller, F D; Kaplan, D R

    2001-07-01

    Recent evidence indicates that naturally occurring neuronal death in mammals is regulated by the interplay between receptor-mediated prosurvival and proapoptotic signals. The neurotrophins, a family of growth factors best known for their positive effects on neuronal biology, have now been shown to mediate both positive and negative survival signals, by signalling through the Trk and p75 neurotrophin receptors, respectively. The mechanisms whereby these two neurotrophin receptors interact to determine neuronal survival have been difficult to decipher, largely because both can signal independently or coincidentally, depending upon the cell or developmental context. Nonetheless, the past several years have seen significant advances in our understanding of this receptor signalling system. In this review, we focus on the proapoptotic actions of the p75 neurotrophin receptor (p75NTR), and on the interplay between Trk and p75NTR that determines neuronal survival. PMID:11529497

  20. Structural Basis of p75 Transmembrane Domain Dimerization.

    PubMed

    Nadezhdin, Kirill D; García-Carpio, Irmina; Goncharuk, Sergey A; Mineev, Konstantin S; Arseniev, Alexander S; Vilar, Marçal

    2016-06-01

    Dimerization of single span transmembrane receptors underlies their mechanism of activation. p75 neurotrophin receptor plays an important role in the nervous system, but the understanding of p75 activation mechanism is still incomplete. The transmembrane (TM) domain of p75 stabilizes the receptor dimers through a disulfide bond, essential for the NGF signaling. Here we solved by NMR the three-dimensional structure of the p75-TM-WT and the functionally inactive p75-TM-C257A dimers. Upon reconstitution in lipid micelles, p75-TM-WT forms the disulfide-linked dimers spontaneously. Under reducing conditions, p75-TM-WT is in a monomer-dimer equilibrium with the Cys(257) residue located on the dimer interface. In contrast, p75-TM-C257A forms dimers through the AXXXG motif on the opposite face of the α-helix. Biochemical and cross-linking experiments indicate that AXXXG motif is not on the dimer interface of p75-TM-WT, suggesting that the conformation of p75-TM-C257A may be not functionally relevant. However, rather than mediating p75 homodimerization, mutagenesis of the AXXXG motif reveals its functional role in the regulated intramembrane proteolysis of p75 catalyzed by the γ-secretase complex. Our structural data provide an insight into the key role of the Cys(257) in stabilization of the weak transmembrane dimer in a conformation required for the NGF signaling. PMID:27056327

  1. Neurotrophins and B-cell malignancies.

    PubMed

    Hillis, Jennifer; O'Dwyer, Michael; Gorman, Adrienne M

    2016-01-01

    Neurotrophins and their receptors act as important proliferative and pro-survival factors in a variety of cell types. Neurotrophins are produced by multiple cell types in both pro- and mature forms, and can act in an autocrine or paracrine fashion. The p75(NTR) and Trk receptors can elicit signalling in response to the presence or absence of their corresponding neurotrophin ligands. This signalling, along with neurotrophin and receptor expression, varies between different cell types. Neurotrophins and their receptors have been shown to be expressed by and elicit signalling in B lymphocytes. In general, most neurotrophins are expressed by activated B-cells and memory B-cells. Likewise, the TrkB95 receptor is seen on activated B-cells, while TrkA and p75(NTR) are expressed by both resting and active B-cells as well as memory B-cells. Nerve growth factor stimulates B-cell proliferation, memory B-cell survival, antibody production and CD40 expression. Brain-derived neurotrophic factor is involved in B-cell maturation in the bone marrow through TrkB95. Overall neurotrophins and their receptors have been shown to be involved in B-cell proliferation, development, differentiation, antibody secretion and survival. As well as expression and activity in healthy B-cells, the neurotrophins and their receptors can contribute to B-cell malignancies including acute lymphoblastic leukaemia, diffuse large B-cell lymphoma, Burkitt's lymphoma and multiple myeloma. They are involved in B-cell malignancy survival and potentially in drug resistance. PMID:26399960

  2. Update on the role of p75NTR in neurological disorders: A novel therapeutic target.

    PubMed

    Shu, Ya-Hai; Lu, Xiu-Min; Wei, Jing-Xiang; Xiao, Lan; Wang, Yong-Tang

    2015-12-01

    As a low-affinity neurotrophins receptor, p75 neurotrophin receptor (p75NTR) is a transmembrane receptor involved in a diverse array of cellular responses, including apoptosis, survival, neurite outgrowth, migration, and cell cycle arrest, which may be related to some neurological disorders, such as Alzheimer's disease (AD), schizophrenia, major depressive disorder (MDD), posttraumatic stress disorder (PTSD), amyotrophic lateral sclerosis (ALS), and Parkinson's disease (PD). Indeed, a series of studies during the last decade has demonstrated that the p75NTR signaling plays key roles in most aspects of the neurological disorder diseases. In spite of the limited information available, this review still tried to summary the relationship between p75NTR and diverse neurological disorder diseases, and tried to further clarify the possible mechanism, which may provide a novel therapeutic target for the treatment of neurological disorders. PMID:26653545

  3. Each Sensory Nerve Arising From the Geniculate Ganglion Expresses a Unique Fingerprint of Neurotrophin and Neurotrophin Receptor Genes

    PubMed Central

    Farbman, Albert I.; Guagliardo, Nick; Sollars, Suzanne I.; Hill, David L.

    2009-01-01

    Neurons in the geniculate ganglion, like those in other sensory ganglia, are dependent on neurotrophins for survival. Most geniculate ganglion neurons innervate taste buds in two regions of the tongue and two regions of the palate; the rest are cutaneous nerves to the skin of the ear. We investigated the expression of four neurotrophins, nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT-3), and NT-4, and five neurotrophin receptors, trkA, trkB, trkC, p75, and truncated trkB (Trn-B) in single sensory neurons of the adult rat geniculate ganglion associated with the five innervation fields. For fungiform papillae, a glass pipette containing biotinylated dextran was placed over the target papilla and the tracer was iontophoresed into the target papilla. For the other target fields, Fluoro-Gold was microinjected. After 3 days, geniculate ganglia were harvested, sectioned, and treated histochemically (for biotinylated dextran) or immunohistochemically (for Fluoro-Gold) to reveal the neurons containing the tracer. Single labeled neurons were harvested from the slides and subjected to RNA amplification and RT-PCR to reveal the neurotrophin or neurotrophin receptor genes that were expressed. Neurons projecting from the geniculate ganglion to each of the five target fields had a unique expression profile of neurotrophin and neurotrophic receptor genes. Several individual neurons expressed more than one neurotrophin receptor or more than one neurotrophin gene. Although BDNF is significantly expressed in taste buds, its primary high affinity receptor, trkB, was not prominently expressed in the neurons. The results are consistent with the interpretation that at least some, perhaps most, of the trophic influence on the sensory neurons is derived from the neuronal somata, and the trophic effect is paracrine or autocrine, rather than target derived. The BDNF in the taste bud may also act in a paracrine or autocrine manner on the trkB expressed

  4. Molecular and Structural Insight into proNGF Engagement of p75NTR and Sortilin

    PubMed Central

    Feng, Dan; Kim, Taeho; Özkan, Engin; Light, Matthew; Torkin, Risa; Teng, Kenneth K.; Hempstead, Barbara L.; Garcia, K. Christopher

    2010-01-01

    Nerve growth factor is initially synthesized as a precursor, proNGF, which is cleaved to release its C-terminal mature form. Recent studies suggest that proNGF is not an inactive precursor, but acts as a signaling ligand distinct from its mature counterpart. Pro- and mature NGF initiate opposing biological responses by utilizing both distinct and shared receptor components. Here, we carry out a structural and biochemical characterization of proNGF interactions with p75NTR and sortilin. We have crystallized proNGF complexed to p75NTR, and present the structure at 3.75 Å resolution. The structure reveals a 2:2 symmetric binding mode, as compared to the asymmetric structure of a previously reported crystal structure of mature NGF complexed to p75NTR, and the 2:2 symmetric complex of Neurotrophin-3 and p75NTR. Here we discuss the possible origins and implications of the different stoichiometries. In the proNGF/p75NTR complex, the pro regions of proNGF are mostly disordered, and two hairpin loops (L2) at the top of NGF dimer have undergone conformational changes in comparison to mature neurotrophin structures, suggesting possible interactions with the pro-peptide. We further explore the binding characteristics of proNGF to sortilin using surface plasmon resonance and cell-based assays, and determine that calcium ions promote the formation of a stable ternary complex of proNGF/sortilin/p75NTR. These results, together with previous structural and mechanistic studies of neurotrophin-receptor interactions, suggest the potential for distinct signaling activities through p75NTR mediated by different neurotrophin-induced conformational changes. PMID:20036257

  5. p75NTR-mediated signaling promotes the survival of myoblasts and influences muscle strength.

    PubMed

    Reddypalli, Shailaja; Roll, Kristin; Lee, Hyung-Kook; Lundell, Martha; Barea-Rodriguez, Edwin; Wheeler, Esther F

    2005-09-01

    During muscle development, the p75(NTR) is expressed transiently on myoblasts. The temporal expression pattern of the receptor raises the possibility that the receptor is influencing muscle development. To test this hypothesis, p75(NTR)-deficient mutant mice were tested for muscle strength by using a standard wire gripe strength test and were found to have significantly decreased strength relative to that of normal mice. When normal mybolasts were examined in vivo for expression of NGF receptors, p75(NTR) was detected on myoblasts but the high affinity NGF receptor, trk A, was not co-expressed with p75(NTR). In vitro, proliferating C2C12 and primary myoblasts co-expressed the p75(NTR) and MyoD, but immunofluorescent analysis of primary myoblasts and RT-PCR analysis of C2C12 mRNA revealed that myoblasts were devoid of trk A. In contrast to the cell death functions that characterize the p75(NTR) in neurons, p75(NTR)-positive primary and C2C12 myoblasts did not differentiate or undergo apoptosis in response to neurotrophins. Rather, myoblasts survived and even proliferated when grown at subconfluent densities in the presence of the neurotrophins. Furthermore, when myoblasts treated with NGF were lysed and immunoprecipitated with antibodies against phosphorylated I-kappaB and AKT, the cells contained increased levels of both phospho-proteins, both of which promote cell survival. By contrast, neurotrophin-treated myoblasts did not induce phosphorylation of Map Kinase p42/44 or p38, indicating the survival was not mediated by the trk A receptor. Taken together, the data indicate that the p75(NTR) mediates survival of myoblasts prior to differentiation and that the activity of this receptor during myogenesis is important for developing muscle. PMID:15754321

  6. Nuclear pore complex remodeling by p75NTR cleavage controls TGF-β signaling and astrocyte functions

    PubMed Central

    Schachtrup, Christian; Ryu, Jae Kyu; Mammadzada, Könül; Khan, Abdullah S.; Carlton, Peter M.; Perez, Alex; Christian, Frank; Le Moan, Natacha; Vagena, Eirini; Baeza-Raja, Bernat; Rafalski, Victoria; Chan, Justin P.; Nitschke, Roland; Houslay, Miles D.; Ellisman, Mark H.; Wyss-Coray, Tony; Palop, Jorge J.; Akassoglou, Katerina

    2016-01-01

    Astrocytes play critical roles in neuronal activity and inhibition of regeneration. Here we show that the cleaved p75 neurotrophin receptor (p75NTR) is a component of the nuclear pore complex (NPC) required for glial scar formation and reduced gamma oscillations in mice via regulation of TGF-β signaling. The cleaved p75NTR interacts with nucleoporins to promote Smad2 nucleocytoplasmic shuttling. Thus, NPC remodeling by regulated intramembrane cleavage of p75NTR controls astrocyte-neuronal communication in response to profibrotic factors. PMID:26120963

  7. Spiral ganglion outgrowth and hearing development in p75-deficient mice.

    PubMed

    Brors, Dominik; Hansen, Stefan; Mlynski, Robert; Volkenstein, Stefan; Aletsee, Christoph; Sendtner, Michael; Ryan, Allen F; Dazert, Stefan

    2008-01-01

    To explore the role of nerve growth factor receptor p75(NTR) during the terminal neuronal development of the mammalian cochlea the onset of hearing and the in vitro response of spiral ganglion neurites to neurotrophin 3 (NT-3), which is known to play a critical role during neonatal inner ear development, were investigated in p75(NTR)-deficient mice (p75(NTR)-/-). Auditory-evoked brain stem response recordings from p75(NTR)-/- and wild-type (WT) littermates were measured from postnatal days (PD) 8 to 23. Additionally, spiral ganglion explants from p75(NTR)-/- and WT animals were dissected and cultured in an organotypic tissue culture system. In both groups, spiral ganglion neurite outgrowth was analyzed with and without NT-3 supplementation. No significant differences in the onset of hearing of mutant mice compared to the WT mice were detected, and both groups showed a similar development of hearing until PD 23. After stimulation with NT-3, neurite outgrowth was enhanced in both p75(NTR)-/- and WT mice. However, neurites from p75(NTR)-/- spiral ganglion explants were longer in both culture conditions. Moreover, NT-3 did not significantly enhance neurite number in p75(NTR)-/-, as it did in WT mice. P75(NTR) has a remarkable influence on spiral ganglion neurite growth behavior. However, p75(NTR) does not seem to be essential for the development of basic hearing function in the first 3 postnatal weeks. PMID:18663291

  8. Toll-6 and Toll-7 function as neurotrophin receptors in the Drosophila central nervous system

    PubMed Central

    McIlroy, Graham; Foldi, Istvan; Aurikko, Jukka; Wentzell, Jill S.; Lim, Mei Ann; Fenton, Janine C.; Gay, Nicholas J.; Hidalgo, Alicia

    2015-01-01

    Neurotrophin receptors corresponding to vertebrate Trk, p75NTR or Sortilin have not been identified in Drosophila, thus it is unknown how neurotrophism may be implemented in insects. Two Drosophila neurotrophins, DNT1 and DNT2, have nervous system functions, but their receptors are unknown. The Toll receptor superfamily has ancient evolutionary origins and a universal function in innate immunity. Here we show that Toll paralogues unrelated to the mammalian neurotrophin receptors function as neurotrophin receptors in fruit-flies. Toll-6 and Toll-7 are expressed in the central nervous system throughout development, and regulate locomotion, motoraxon targeting and neuronal survival. DNT1 and 2 interact genetically with Toll-6 and 7, bind to Toll-7 and 6 promiscuously, and are distributed in vivo in complementary or overlapping domains. We conclude that in fruit-flies, Tolls are not only involved in development and immunity but also in neurotrophism, revealing an unforeseen relationship between the neurotrophin and Toll protein families. PMID:23892553

  9. p75NTR ectodomain is a physiological neuroprotective molecule against amyloid-beta toxicity in the brain of Alzheimer's disease.

    PubMed

    Yao, X-Q; Jiao, S-S; Saadipour, K; Zeng, F; Wang, Q-H; Zhu, C; Shen, L-L; Zeng, G-H; Liang, C-R; Wang, J; Liu, Y-H; Hou, H-Y; Xu, X; Su, Y-P; Fan, X-T; Xiao, H-L; Lue, L-F; Zeng, Y-Q; Giunta, B; Zhong, J-H; Walker, D G; Zhou, H-D; Tan, J; Zhou, X-F; Wang, Y-J

    2015-11-01

    In Alzheimer's disease (AD), neurodegenerative signals such as amyloid-beta (Aβ) and the precursors of neurotrophins, outbalance neurotrophic signals, causing synaptic dysfunction and neurodegeneration. The neurotrophin receptor p75 (p75NTR) is a receptor of Aβ and mediates Aβ-induced neurodegenerative signals. The shedding of its ectodomain from the cell surface is physiologically regulated; however, the function of the diffusible p75NTR ectodomain (p75ECD) after shedding remains largely not known. Here, we show that p75ECD levels in cerebrospinal fluid and in the brains of Alzheimer's patients and amyloid-beta precursor protein (APP)/PS1 transgenic mice were significantly reduced, due to inhibition of the sheddase-tumor necrosis factor-alpha-converting enzyme by Aβ. Restoration of p75ECD to the normal level by brain delivery of the gene encoding human p75ECD before or after Aβ deposition in the brain of APP/PS1 mice reversed the behavioral deficits and AD-type pathologies, such as Aβ deposit, apoptotic events, neuroinflammation, Tau phosphorylation and loss of dendritic spine, neuronal structures and synaptic proteins. Furthermore, p75ECD can also reduce amyloidogenesis by suppressing β-secretase expression and activities. Our data demonstrate that p75ECD is a physiologically neuroprotective molecule against Aβ toxicity and would be a novel therapeutic target and biomarker for AD. PMID:25917367

  10. p75NTR ectodomain is a physiological neuroprotective molecule against amyloid-beta toxicity in the brain of Alzheimer's disease

    PubMed Central

    Yao, X-Q; Jiao, S-S; Saadipour, K; Zeng, F; Wang, Q-H; Zhu, C; Shen, L-L; Zeng, G-H; Liang, C-R; Wang, J; Liu, Y-H; Hou, H-Y; Xu, X; Su, Y-P; Fan, X-T; Xiao, H-L; Lue, L-F; Zeng, Y-Q; Giunta, B; Zhong, J-H; Walker, D G; Zhou, H-D; Tan, J; Zhou, X-F; Wang, Y-J

    2015-01-01

    In Alzheimer's disease (AD), neurodegenerative signals such as amyloid-beta (Aβ) and the precursors of neurotrophins, outbalance neurotrophic signals, causing synaptic dysfunction and neurodegeneration. The neurotrophin receptor p75 (p75NTR) is a receptor of Aβ and mediates Aβ-induced neurodegenerative signals. The shedding of its ectodomain from the cell surface is physiologically regulated; however, the function of the diffusible p75NTR ectodomain (p75ECD) after shedding remains largely not known. Here, we show that p75ECD levels in cerebrospinal fluid and in the brains of Alzheimer's patients and amyloid-beta precursor protein (APP)/PS1 transgenic mice were significantly reduced, due to inhibition of the sheddase-tumor necrosis factor-alpha-converting enzyme by Aβ. Restoration of p75ECD to the normal level by brain delivery of the gene encoding human p75ECD before or after Aβ deposition in the brain of APP/PS1 mice reversed the behavioral deficits and AD-type pathologies, such as Aβ deposit, apoptotic events, neuroinflammation, Tau phosphorylation and loss of dendritic spine, neuronal structures and synaptic proteins. Furthermore, p75ECD can also reduce amyloidogenesis by suppressing β-secretase expression and activities. Our data demonstrate that p75ECD is a physiologically neuroprotective molecule against Aβ toxicity and would be a novel therapeutic target and biomarker for AD. PMID:25917367

  11. NRAGE, a p75NTR adaptor protein, is required for developmental apoptosis in vivo.

    PubMed

    Bertrand, M J M; Kenchappa, R S; Andrieu, D; Leclercq-Smekens, M; Nguyen, H N T; Carter, B D; Muscatelli, F; Barker, P A; De Backer, O

    2008-12-01

    NRAGE (also known as Maged1, Dlxin) is a member of the MAGE gene family that may play a role in the neuronal apoptosis that is regulated by the p75 neurotrophin receptor (p75NTR). To test this hypothesis in vivo, we generated NRAGE knockout mice and found that NRAGE deletion caused a defect in developmental apoptosis of sympathetic neurons of the superior cervical ganglia, similar to that observed in p75NTR knockout mice. Primary sympathetic neurons derived from NRAGE knockout mice were resistant to apoptosis induced by brain-derived neurotrophic factor (BDNF), a pro-apoptotic p75NTR ligand, and NRAGE-deficient sympathetic neurons show attenuated BDNF-dependent JNK activation. Hair follicle catagen is an apoptosis-like process that is dependent on p75NTR signaling; we show that NRAGE and p75NTR show regulated co-expression in the hair follicle and that identical defects in hair follicle catagen are present in NRAGE and p75NTR knockout mice. Interestingly, NRAGE knockout mice have severe defects in motoneuron apoptosis that are not observed in p75NTR knockout animals, raising the possibility that NRAGE may facilitate apoptosis induced by receptors other than p75NTR. Together, these studies demonstrate that NRAGE plays an important role in apoptotic-signaling in vivo. PMID:18772898

  12. Bicaudal-D1 regulates the intracellular sorting and signalling of neurotrophin receptors

    PubMed Central

    Terenzio, Marco; Golding, Matthew; Russell, Matthew R G; Wicher, Krzysztof B; Rosewell, Ian; Spencer-Dene, Bradley; Ish-Horowicz, David; Schiavo, Giampietro

    2014-01-01

    We have identified a new function for the dynein adaptor Bicaudal D homolog 1 (BICD1) by screening a siRNA library for genes affecting the dynamics of neurotrophin receptor-containing endosomes in motor neurons (MNs). Depleting BICD1 increased the intracellular accumulation of brain-derived neurotrophic factor (BDNF)-activated TrkB and p75 neurotrophin receptor (p75NTR) by disrupting the endosomal sorting, reducing lysosomal degradation and increasing the co-localisation of these neurotrophin receptors with retromer-associated sorting nexin 1. The resulting re-routing of active receptors increased their recycling to the plasma membrane and altered the repertoire of signalling-competent TrkB isoforms and p75NTR available for ligand binding on the neuronal surface. This resulted in attenuated, but more sustained, AKT activation in response to BDNF stimulation. These data, together with our observation that Bicd1 expression is restricted to the developing nervous system when neurotrophin receptor expression peaks, indicate that BICD1 regulates neurotrophin signalling by modulating the endosomal sorting of internalised ligand-activated receptors. PMID:24920579

  13. NMR Dynamics of Transmembrane and Intracellular Domains of p75NTR in Lipid-Protein Nanodiscs.

    PubMed

    Mineev, Konstantin S; Goncharuk, Sergey A; Kuzmichev, Pavel K; Vilar, Marçal; Arseniev, Alexander S

    2015-08-18

    P75NTR is a type I integral membrane protein that plays a key role in neurotrophin signaling. However, structural data for the receptor in various functional states are sparse and controversial. In this work, we studied the spatial structure and mobility of the transmembrane and intracellular parts of p75NTR, incorporated into lipid-protein nanodiscs of various sizes and compositions, by solution NMR spectroscopy. Our data reveal a high level of flexibility and disorder in the juxtamembrane chopper domain of p75NTR, which results in the motions of the receptor death domain being uncoupled from the motions of the transmembrane helix. Moreover, none of the intracellular domains of p75NTR demonstrated a propensity to interact with the membrane or to self-associate under the experimental conditions. The obtained data are discussed in the context of the receptor activation mechanism. PMID:26287629

  14. Reduced Anxiety-Like Behavior and Altered Hippocampal Morphology in Female p75NTRexon IV−/− Mice

    PubMed Central

    Puschban, Zoe; Sah, Anupam; Grutsch, Isabella; Singewald, Nicolas; Dechant, Georg

    2016-01-01

    The presence of the p75 neurotrophin receptor (p75NTR) in adult basal forebrain cholinergic neurons, precursor cells in the subventricular cell layer and the subgranular cell layer of the hippocampus has been linked to alterations in learning as well as anxiety- and depression- related behaviors. In contrast to previous studies performed in a p75NTRexon III−/− model still expressing the short isoform of the p75NTR, we focused on locomotor and anxiety–associated behavior in p75NTRexon IV−/− mice lacking both p75NTR isoforms. Comparing p75NTRexon IV−/− and wildtype mice for both male and female animals showed an anxiolytic-like behavior as evidenced by increased central activities in the open field paradigm and flex field activity system as well as higher numbers of open arm entries in the elevated plus maze test in female p75NTR knockout mice. Morphometrical analyses of dorsal and ventral hippocampus revealed a reduction of width of the dentate gyrus and the granular cell layer in the dorsal but not ventral hippocampus in male and female p75NTRexon IV−/− mice. We conclude that germ-line deletion of p75NTR seems to differentially affect morphometry of dorsal and ventral dentate gyrus and that p75NTR may play a role in anxiety-like behavior, specifically in female mice. PMID:27313517

  15. The Role of Rab Proteins in Neuronal Cells and in the Trafficking of Neurotrophin Receptors

    PubMed Central

    Bucci, Cecilia; Alifano, Pietro; Cogli, Laura

    2014-01-01

    Neurotrophins are a family of proteins that are important for neuronal development, neuronal survival and neuronal functions. Neurotrophins exert their role by binding to their receptors, the Trk family of receptor tyrosine kinases (TrkA, TrkB, and TrkC) and p75NTR, a member of the tumor necrosis factor (TNF) receptor superfamily. Binding of neurotrophins to receptors triggers a complex series of signal transduction events, which are able to induce neuronal differentiation but are also responsible for neuronal maintenance and neuronal functions. Rab proteins are small GTPases localized to the cytosolic surface of specific intracellular compartments and are involved in controlling vesicular transport. Rab proteins, acting as master regulators of the membrane trafficking network, play a central role in both trafficking and signaling pathways of neurotrophin receptors. Axonal transport represents the Achilles' heel of neurons, due to the long-range distance that molecules, organelles and, in particular, neurotrophin-receptor complexes have to cover. Indeed, alterations of axonal transport and, specifically, of axonal trafficking of neurotrophin receptors are responsible for several human neurodegenerative diseases, such as Huntington’s disease, Alzheimer’s disease, amyotrophic lateral sclerosis and some forms of Charcot-Marie-Tooth disease. In this review, we will discuss the link between Rab proteins and neurotrophin receptor trafficking and their influence on downstream signaling pathways. PMID:25295627

  16. The p75{sup NTR} tumor suppressor induces cell cycle arrest facilitating caspase mediated apoptosis in prostate tumor cells

    SciTech Connect

    Khwaja, Fatima; Tabassum, Arshia; Allen, Jeff; Djakiew, Daniel . E-mail: djakiewd@georgetown.edu

    2006-03-24

    The p75 neurotrophin receptor (p75{sup NTR}) is a death receptor which belongs to the tumor necrosis factor receptor super-family of membrane proteins. This study shows that p75{sup NTR} retarded cell cycle progression by induced accumulation of cells in G0/G1 and a reduction in the S phase of the cell cycle. The rescue of tumor cells from cell cycle progression by a death domain deleted ({delta}DD) dominant-negative antagonist of p75{sup NTR} showed that the death domain transduced anti-proliferative activity in a ligand-independent manner. Conversely, addition of NGF ligand rescued retardation of cell cycle progression with commensurate changes in components of the cyclin/cdk holoenzyme complex. In the absence of ligand, p75{sup NTR}-dependent cell cycle arrest facilitated an increase in apoptotic nuclear fragmentation of the prostate cancer cells. Apoptosis of p75{sup NTR} expressing cells occurred via the intrinsic mitochondrial pathway leading to a sequential caspase-9 and -7 cascade. Since the death domain deleted dominant-negative antagonist of p75{sup NTR} rescued intrinsic caspase associated apoptosis in PC-3 cells, this shows p75{sup NTR} was integral to ligand independent induction of apoptosis. Moreover, the ability of ligand to ameliorate the p75{sup NTR}-dependent intrinsic apoptotic cascade indicates that NGF functioned as a survival factor for p75{sup NTR} expressing prostate cancer cells.

  17. Characterization of p75{sup +} ectomesenchymal stem cells from rat embryonic facial process tissue

    SciTech Connect

    Wen, Xiujie; Liu, Luchuan; Deng, Manjing; Zhang, Li; Liu, Rui; Xing, Yongjun; Zhou, Xia; Nie, Xin

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer Ectomesenchymal stem cells (EMSCs) were found to migrate to rat facial processes at E11.5. Black-Right-Pointing-Pointer We successfully sorted p75NTR positive EMSCs (p75{sup +} EMSCs). Black-Right-Pointing-Pointer p75{sup +} EMSCs up to nine passages showed relative stable proliferative activity. Black-Right-Pointing-Pointer We examined the in vitro multilineage potential of p75{sup +} EMSCs. Black-Right-Pointing-Pointer p75{sup +}EMSCs provide an in vitro model for tooth morphogenesis. -- Abstract: Several populations of stem cells, including those from the dental pulp and periodontal ligament, have been isolated from different parts of the tooth and periodontium. The characteristics of such stem cells have been reported as well. However, as a common progenitor of these cells, ectomesenchymal stem cells (EMSCs), derived from the cranial neural crest have yet to be fully characterized. The aim of this study was to better understand the characteristics of EMSCs isolated from rat embryonic facial processes. Immunohistochemical staining showed that EMSCs had migrated to rat facial processes at E11.5, while the absence of epithelial invagination or tooth-like epithelium suggested that any epithelial-mesenchymal interactions were limited at this stage. The p75 neurotrophin receptor (p75NTR), a typical neural crest marker, was used to select p75NTR-positive EMSCs (p75{sup +} EMSCs), which were found to show a homogeneous fibroblast-like morphology and little change in the growth curve, proliferation capacity, and cell phenotype during cell passage. They also displayed the capacity to differentiate into diverse cell types under chemically defined conditions in vitro. p75{sup +} EMSCs proved to be homogeneous, stable in vitro and potentially capable of multiple lineages, suggesting their potential for application in dental or orofacial tissue engineering.

  18. Neurotrophins and the immune system

    PubMed Central

    Vega, José A; García-Suárez, Olivia; Hannestad, Jonas; Pérez-Pérez, Marta; Germanà, Antonino

    2003-01-01

    The neurotrophins are a family of polypeptide growth factors that are essential for the development and maintenance of the vertebrate nervous system. In recent years, data have emerged indicating that neurotrophins could have a broader role than their name might suggest. In particular, the putative role of NGF and its receptor TrkA in immune system homeostasis has become a much studied topic, whereas information on the other neurotrophins is scarce in this regard. This paper reviews what is known about the expression and possible functions of neurotrophins and their receptors in different immune tissues and cells, as well as recent data obtained from studies of transgenic mice in our laboratory. Results from studies to date support the idea that neurotrophins may regulate some immune functions. They also play an important role in the development of the thymus and in the survival of thymocytes. PMID:12892403

  19. Neurotrophin-receptor immunoreactive neurons in mesopontine regions involved in the control of behavioral states.

    PubMed

    Yamuy, J; Sampogna, S; Chase, M H

    2000-06-01

    The microinjection of nerve growth factor (NGF) and neurotrophin-3 (NT-3) into the rostral pontine tegmentum of adult cats rapidly induces long-lasting episodes of rapid eye movement (REM) sleep [J. Yamuy, F.R. Morales, M.H. Chase, Induction of rapid eye movement sleep by the microinjection of nerve growth factor into the pontine reticular formation of the cat, Neuroscience 66 (1995) 9-13]. Because this effect may be mediated by neurotrophin receptors, we sought to determine the distribution of neurons that contain low- and high-affinity neurotrophin receptors in regions of the feline pons and mesencephalon which are involved in the generation of REM sleep as well as neuronal groups that are involved in the control of REM sleep-related patterns of physiological activity. Using antibodies directed against p75, trkA, trkB and trkC, immunolabeled neurons were present in the latero-dorsal and pedunculo-pontine tegmental nuclei, the peribrachial nuclei, medial and lateral pontine reticular formation, the raphe nuclei, and the locus coeruleus. Giant reticular cells and large neurons in the mesencephalic trigeminal nucleus were immunoreactive for p75 and all trk receptors. Neurons that were devoid of neurotrophin-receptor immunoreactivity were intermingled with immunostained neurons in all explored structures. Thus, both low- and high-affinity neurotrophin receptors are conspicuously present in neurons located in mesopontine regions of adult cats. These data underscore the importance of neurotrophin-induced trophic actions on mesopontine neurons. Furthermore, the results support the hypothesis that NGF and NT-3 may modulate the electrical activity of neurons in the rostral pontine tegmentum that are responsible for the generation of REM sleep by acting on one or more of the neurotrophin receptors. PMID:10825475

  20. Neurotrophin and Neurotrophin Receptors in Vascular Smooth Muscle Cells

    PubMed Central

    Donovan, Michael J.; Miranda, Rajesh C.; Kraemer, Rosemary; McCaffrey, Timothy A.; Tessarollo, Lino; Mahadeo, Debbie; Sharif, Setareh; Kaplan, David R.; Tsoulfas, Pantelis; Parada, Luis; Toran-Allerand, C. Dominique; Hajjar, David P.; Hempstead, Barbara L.

    1995-01-01

    The neurotrophins, a family of related polypeptide growth factors including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin (NT)-3 and NT-4/5 promote the survival and differentiation of distinctive sets of embryonic neurons. Here we define a new functional role for neurotrophins, as autocrine or local paracrine mediators of vascular smooth muscle cell migration. We have identified neurotrophins, and their cognate receptors, the trk tyrosine kinases, in human and rat vascular smooth muscle cells in vivo. In vitro, cultured human smooth muscle cells express BDNF; NT-3; and trk A, B, and C Similarly, rat smooth muscle cells expressed all three trk receptors as well as all four neurotrophins. Moreover, NGF induces cultured human smooth muscle cell migration at subnanomolar concentrations. In the rat aortic balloon deendothelialization model of vascular injury, the expression of NGF, BDNF, and their receptors trk A and trk B increased dramatically in the area of injury within 3 days and persisted during the formation of the neointima. In human coronary atherosclerotic lesions, BDNF, NT-3, and NT-4/5, and the trk B and trk C receptors could be demonstrated in smooth muscle cells. These findings suggest that neurotrophins play an important role in regulating the response of vascular smooth muscle cells to injury. ImagesFigure 1Figure 2Figure 3Figure 5Figure 6Figure 7Figure 8 PMID:7639328

  1. Intramuscular delivery of p75NTR ectodomain by an AAV vector attenuates cognitive deficits and Alzheimer's disease-like pathologies in APP/PS1 transgenic mice.

    PubMed

    Wang, Qing-Hua; Wang, Ye-Ran; Zhang, Tao; Jiao, Shu-Sheng; Liu, Yu-Hui; Zeng, Fan; Li, Jing; Yao, Xiu-Qing; Zhou, Hua-Dong; Zhou, Xin-Fu; Wang, Yan-Jiang

    2016-07-01

    The neurotrophin receptor p75 (p75NTR) is a receptor for amyloid-beta (Aβ) and mediates Aβ-induced neurodegenerative signals. The ectodomain of p75NTR (p75ECD) is a physiological protective factor against Aβ in Alzheimer's disease (AD). We have previously demonstrated that the shedding of p75ECD from the cell surface is down-regulated in AD brains and restoration of the p75ECD level in the brain, through intracranial administration of p75ECD by adeno-associated virus vectors, attenuates AD-like pathologies in an AD mouse model. In this study, we further investigated the feasibility and efficacy of peripheral administration of AAV-p75ECD on brain amyloid burden and associated pathogenesis. We found that intramuscular delivery of AAV-p75ECD increased the level of p75ECD in the blood, significantly improved the behavioral phenotype of amyloid precursor protein/PS1 transgenic mice, and reduced brain amyloid burden, attenuated Tau hyperphosphorylation, and neuroinflammation. Furthermore, intramuscular delivery of AAV-p75ECD was well tolerated. Our results indicate that peripheral delivery of p75ECD represents a safe and effective therapeutic strategy for AD. The ectodomain of p75NTR (p75ECD) is a physiological protective factor against amyloid-beta (Aβ) in Alzheimer's disease (AD). Intramuscular delivery of AAV-p75ECD increased the p75ECD levels in the blood, reduced brain amyloid burden through a 'peripheral sink' mechanism and alleviates AD-type pathologies. Peripheral delivery of p75ECD represents a promising therapeutic strategy for AD. PMID:26991827

  2. Phytochemicals That Regulate Neurodegenerative Disease by Targeting Neurotrophins: A Comprehensive Review

    PubMed Central

    Venkatesan, Ramu; Ji, Eunhee; Kim, Sun Yeou

    2015-01-01

    Alzheimer's disease (AD), characterized by progressive dementia and deterioration of cognitive function, is an unsolved social and medical problem. Age, nutrition, and toxins are the most common causes of AD. However, currently no credible treatment is available for AD. Traditional herbs and phytochemicals may delay its onset and slow its progression and also allow recovery by targeting multiple pathological causes by antioxidative, anti-inflammatory, and antiamyloidogenic properties. They also regulate mitochondrial stress, apoptotic factors, free radical scavenging system, and neurotrophic factors. Neurotrophins such as BDNF, NGF, NT3, and NT4/5 play a vital role in neuronal and nonneuronal responses to AD. Neurotrophins depletion accelerates the progression of AD and therefore, replacing such neurotrophins may be a potential treatment for neurodegenerative disease. Here, we review the phytochemicals that mediate the signaling pathways involved in neuroprotection specifically neurotrophin-mediated activation of Trk receptors and members of p75NTR superfamily. We focus on representative phenolic derivatives, iridoid glycosides, terpenoids, alkaloids, and steroidal saponins as regulators of neurotrophin-mediated neuroprotection. Although these phytochemicals have attracted attention owing to their in vitro neurotrophin potentiating activity, their in vivo and clinical efficacy trials has yet to be established. Therefore, further research is necessary to prove the neuroprotective effects in preclinical models and in humans. PMID:26075266

  3. Peripheral axon crush elevates transport of p75NTR in the central projection of sensory neurones of rats.

    PubMed

    Delcroix, Jean-Dominique; Patel, Jyoti; Averill, Sharon; Tomlinson, David R; Priestley, John V; Fernyhough, Paul

    2003-11-20

    The effect of peripheral axon crush on the axonal transport of the neurotrophin receptors, p75(NTR) and trkA, was studied in dorsal roots of adult rats. Lumbar dorsal roots were crushed for 3-6 h to cause accumulation of p75(NTR) and trkA. Immunohistochemistry showed the presence of the NGF receptors in axons, indicating retrograde and anterograde axonal transport in the dorsal root. Western blots confirmed that the time course of accumulation of p75(NTR) was consistent with fast axonal transport. However, trkA accumulation was too low to indicate significant levels of axonal transport. Sciatic nerve crush induced a 2-fold increase (P<0.05) in the bidirectional axonal transport of p75(NTR) in the dorsal root while trkA transport remained below detectable levels. PMID:14623136

  4. Selection of human p75NTR tag SNPs and its biological significance for clinical association studies.

    PubMed

    Wang, Yong-Tang; Lu, Xiu-Min; Shu, Ya-Hai; Xiao, Lan; Chen, Kai-Ting

    2014-01-01

    To select tag single nucleotide polymorphisms (SNPs) within and around human p75 neurotrophin receptor (p75NTR) gene in Chinese Han population, the sequence involving p75NTR gene as well as the upstream and downstream of the gene was identified according to the data from National Center for Biotechnology Information (NCBI) GenBank database, and the SNP genotype data involving 63 SNPs in the regions were obtained from Chinese Han Beijing (CHB) population of HapMap database. Then, Haploview (version 4.2) was used to calculate linkage disequilibrium (LD) statistics for the selected 32 common SNPs with a minor allele frequence (MAF) more than 0.05. Haplotype blocks were constructed throughout the p75NTR gene according to the upper and the lower 95% confidence bound of D' value, and the tag SNPs were selected based on the r2 and LOD values between SNPs as well as the results of bioinformatics analysis. The results indicated that five haplotype blocks were constructed within and around p75NTR gene and 12 tag SNPs including rs2537710, rs603769, rs614455, rs2537706, rs534561, rs2072445, rs2072446, rs7219709, rs734194, rs741071, rs741073 and rs2671641 were selected to represent the other 51 SNPs in p75NTR gene. Therefore, the 12 selected SNPs may act as tag SNPs for the entire p75NTR gene in Chinese Han population, which will provide an effective way to select tag SNPs in a whole gene, and its biological significance is to further guide the clinical association studies between the candidate gene and disease susceptibility. PMID:25227100

  5. Changes in Spontaneous Firing Patterns of Cerebellar Purkinje Cells in p75 Knockout Mice

    PubMed Central

    Tian, Jinbin; Tep, Chhavy; Zhu, Michael X.; Yoon, Sung Ok

    2013-01-01

    The p75 neurotrophin receptor is highly expressed in the developing nervous system and is required for neuronal survival, growth and synaptic transmission. In young mice, p75 is present in both granular cells and Purkinje cells of the cerebellum. Although p75 has been implicated in modulation of neuronal excitability in several neuronal types, whether and how it affects the excitability of cerebellar Purkinje neurons remained unclear. Using extracellular recordings of spontaneous firing of Purkinje neurons in cerebellar slices prepared from wild type and p75 knockout mice, we measured intrinsic firing properties in the presence of fast synaptic blockers of more than 200 Purkinje cells, each for a period of 5 min, for each genotype. We detected a significant increase in the mean firing frequency in p75−/− neurons comparing to the wild type littermates. Upon separating tonically firing from phasically firing cells, i.e. cells with firing pauses of longer than 300 msec, we observed that the change mainly arose from phasic firing cells and can be explained by an increase in the firing/silence ratio and a decrease in the number of long pauses during the 5-min recording period. We conclude that p75 plays an important role in regulating the firing-to-silence transition during the phasic firing period of the spontaneous firing of Purkinje cells. Thus, p75 exerts a modulatory function on Purkinje cell firing patterns, through which it may act as a key player in motor coordination and other cerebellum-regulated activities since Purkinje cells represent the sole neuronal output of the cerebellar cortex. PMID:23307658

  6. Ligand-Induced Dynamics of Neurotrophin Receptors Investigated by Single-Molecule Imaging Approaches

    PubMed Central

    Marchetti, Laura; Luin, Stefano; Bonsignore, Fulvio; de Nadai, Teresa; Beltram, Fabio; Cattaneo, Antonino

    2015-01-01

    Neurotrophins are secreted proteins that regulate neuronal development and survival, as well as maintenance and plasticity of the adult nervous system. The biological activity of neurotrophins stems from their binding to two membrane receptor types, the tropomyosin receptor kinase and the p75 neurotrophin receptors (NRs). The intracellular signalling cascades thereby activated have been extensively investigated. Nevertheless, a comprehensive description of the ligand-induced nanoscale details of NRs dynamics and interactions spanning from the initial lateral movements triggered at the plasma membrane to the internalization and transport processes is still missing. Recent advances in high spatio-temporal resolution imaging techniques have yielded new insight on the dynamics of NRs upon ligand binding. Here we discuss requirements, potential and practical implementation of these novel approaches for the study of neurotrophin trafficking and signalling, in the framework of current knowledge available also for other ligand-receptor systems. We shall especially highlight the correlation between the receptor dynamics activated by different neurotrophins and the respective signalling outcome, as recently revealed by single-molecule tracking of NRs in living neuronal cells. PMID:25603178

  7. Differential levels of p75NTR ectodomain in CSF and blood in patients with Alzheimer's disease: a novel diagnostic marker

    PubMed Central

    Jiao, S-S; Bu, X-L; Liu, Y-H; Wang, Q-H; Liu, C-H; Yao, X-Q; Zhou, X-F; Wang, Y-J

    2015-01-01

    Alzheimer's disease (AD) is the primary cause of dementia in the elderly. The ectodomain of p75 neurotrophin receptor (p75NTR-ECD) has been suggested to play important roles in regulating beta-amyloid (Aβ) deposition and in protecting neurons from the toxicity of soluble Aβ. However, whether and how the serum and cerebrospinal fluid (CSF) levels of p75NTR-ECD change in patients with AD are not well documented. In the present study, we determined the concentrations of serum p75NTR-ECD in an AD group, a Parkinson disease group and a stroke group, as well as in a group of elderly controls without neurological disorders (EC). We also determined the levels of CSF p75NTR-ECD in a subset of the AD and EC groups. Our data showed that a distinct p75NTR-ECD profile characterized by a decreased CSF level and an increased serum level was present concomitantly with AD patients but not with other diseases. p75NTR-ECD levels in both the serum and CSF were strongly correlated with Mini-Mental State Examination (MMSE) scores and showed sound differential diagnostic value for AD. Moreover, when combining CSF Aβ42, CSF Aβ42/40, CSF ptau181 or CSF ptau181/Aβ42 with CSF p75NTR-ECD, the area under the receiver operating characteristic curve (AUC) and diagnostic accuracies improved. These findings indicate that p75NTR-ECD can serve as a specific biomarker for AD and the determination of serum and CSF p75NTR-ECD levels is likely to be helpful in monitoring AD progression. PMID:26440538

  8. Cell Line-Dependent Variability of Coordinate Expression of p75NTR and CRABP1 and Modulation of Effects of Fenretinide on Neuroblastoma Cells

    PubMed Central

    Yang, Yaoli Pu; Wang, Simeng; Li, Xingguo; Schor, Nina F.

    2016-01-01

    Neuroblastoma is a childhood neural crest tumor. Fenretinide, a retinoic acid analogue, induces accumulation of mitochondrial reactive oxygen species and consequent apoptosis in neuroblastoma cells. The p75 neurotrophin receptor (p75NTR) enhances the antineuroblastoma cell efficacy of fenretinide in vitro. We examined the role of the retinoid binding protein, CRABP1, in p75NTR-mediated potentiation of the efficacy of fenretinide. Knockdown and overexpression, respectively, of either p75NTR or CRABP1 were effected in neuroblastoma cell lines using standard techniques. Expression was determined by qRT-PCR and confirmed at the protein level by Western blot. Metabolic viability was determined by Alamar blue assay. While protein content of CRABP1 correlated roughly with that of p75NTR in the three neuroblastoid or epithelioid human neuroblastoma cell lines studied, manipulation of p75NTR expression resulted in cell line-dependent, variable change in CRABP1 expression. Furthermore, in some cell lines, induced expression of CRABP1 in the absence of p75NTR did not alter cell sensitivity to fenretinide treatment. The effects of manipulation of p75NTR expression on CRABP1 expression and the effects of CRABP1 expression on fenretinide efficacy are therefore neuroblastoma cell line-dependent. Potentiation of the antineuroblastoma cell effects of fenretinide by p75NTR is not mediated solely through CRABP1. PMID:26843908

  9. Cholesterol biosynthesis and the pro-apoptotic effects of the p75 nerve growth factor receptor in PC12 pheochromocytoma cells.

    PubMed

    Yan, Chaohua; Mirnics, Zeljka Korade; Portugal, Carmel F; Liang, Ye; Nylander, Karen D; Rudzinski, Marcelo; Zaccaro, Clara; Saragovi, H Uri; Schor, Nina Felice

    2005-10-01

    Neocarzinostatin (NCS), an enediyne antimitotic agent, induces cell death in both p75NTR neurotrophin receptor (NTR)-positive and p75NTR-negative PC12 cells in a concentration-dependent fashion. However, p75NTR-positive cells demonstrate a higher susceptibility to NCS-induced cell damage. Furthermore, treatment of p75NTR-positive cells with the p75NTR-specific ligand, MC192, resulted in apoptosis, while treatment of these cells with the TrkA-specific ligand, NGF-mAbNGF30, protected them from NCS-induced death, implying that both the naked and liganded p75NTR receptors have a pro-apoptotic effect on PC12 cells. Microarray studies aimed at examining differential gene expression between p75NTR-positive and p75NTR-negative cells suggested that enzymes of the cholesterol biosynthetic pathway are differentially expressed. We therefore tested the hypothesis that altered cholesterol biosynthesis contributes directly to the pro-apoptotic effects of p75NTR in this PC12 cell-NCS model. Subsequent Northern blotting studies confirmed that the expression of p75NTR is associated with the upregulation of cholesterol biosynthetic enzymes including 3-hydroxy-3-methylglutaryl CoA reductase (HMG CoA reductase), farnesyl-diphosphate synthase, and 7-dehydro-cholesterol reductase. Mevastatin, an HMG CoA reductase inhibitor, converts the apoptosis susceptibility of p75NTR-positive cells to that of p75NTR-negative cells. It does so at concentrations that do not themselves alter cell survival. These studies provide evidence that the pro-apoptotic effects of p75NTR in PC12 cells are related to the upregulation of cholesterol biosynthetic enzymes and consequent increased cholesterol biosynthesis. PMID:15967538

  10. Palbociclib in Combination With Tamoxifen as First Line Therapy for Metastatic Hormone Receptor Positive Breast Cancer

    ClinicalTrials.gov

    2016-07-05

    Hormone Receptor Positive Malignant Neoplasm of Breast; Human Epidermal Growth Factor 2 Negative Carcinoma of Breast; Estrogen Receptor Positive Breast Cancer; Progesterone Receptor Positive Tumor; Metastatic Breast Cancer

  11. Expression of neurotrophins and their receptors in human CD34+ bone marrow cells.

    PubMed

    Paczkowska, E; Piecyk, K; Luczkowska, K; Kotowski, M; Roginska, D; Pius-Sadowska, E; Oronowicz, K; Ostrowski, M; Machalinski, B

    2016-02-01

    Bone marrow (BM) CD34+ cells have the ability to secrete growth factors, cytokines, and chemotactic factors. We sought to better characterize this population and to investigate whether human BM CD34+ cells express neurotrophins (NTs) and their relevant receptors. We also compared their expression levels with BM nucleated cells (NCs). BM CD34+ cells were evaluated with respect to the expression levels of neurotrophins using qRT-PCR, immunofluorescent staining, and Western blotting. Next, the expression of specific (TrkA, TrkB, TrkC) and non-specific (p75NTR) neurotrophin receptors was detected by qRT-PCR and immunofluorescent staining in BM CD34+ cells. Using qRT- PCR, we show that even in the absence of inducing factors, CD34+ cells spontaneously express neurotrophins such as NGF, BDNF, NT-3, and NT-4. In addition, the NT expression levels in BM CD34+ cells are considerably higher than in NCs. Furthermore, we confirmed intracellular NT expression in BM CD34+ cells at the protein level using immunofluorescent staining and Western blotting. Using qRT-PCR, we found that immunomagnetically separated BM CD34+ cells spontaneously express high-affinity neurotrophin receptors (TrkA, TrkB, and TrkC) and the low-affinity receptor p75NTR at higher levels than NCs. Immunomagnetic CD34+ cell separation enables for the rapid and gentle sorting of stem/progenitor cells (SPCs) to prepare specific cell types for use in research and clinical applications. Our study suggests that BM CD34+ cells have the potential to support trophic factors for neural tissue and could contribute towards the protection and regeneration of neural cells. PMID:27010904

  12. Finding ATF4/p75NTR/IL-8 Signal Pathway in Endothelial–Mesenchymal Transition by Safrole Oxide

    PubMed Central

    Zhao, Wenbo; Yue, Hongwei; Su, Le; Zhang, ShangLi; Zhao, Jing

    2014-01-01

    Targeting the endothelial-to-mesenchymal transition (EndoMT) may be a novel therapeutic strategy for cancer and various diseases induced by fibrosis. We aimed to identify a small chemical molecule as an inducer of EndoMT and find a new signal pathway by using the inducer. Safrole oxide (SFO), 50 µg/ml, could most effectively induce EndoMT within 12 h. To understand the underlying molecular mechanism, we performed microarray, quantitative real-time PCR and western blot analysis to find key factors involved in SFO-induced EndoMT and demonstrated the involvement of the factors by RNAi. The expression of activating transcription factor 4 (ATF4), p75 neurotrophin receptor (p75NTR), and interleukin 8 (IL-8) was greatly increased in SFO-induced EndoMT. Knockdown of ATF4 inhibited the SFO-induced EndoMT completely, and knockdown of p75NTR or IL-8 partially inhibited the EndoMT, which suggests that all three factors were involved in the process. Furthermore, knockdown of p75NTR inhibited the SFO-increased IL-8 expression and secretion, and knockdown of ATF4 inhibited SFO-increased p75NTR level significantly. The ATF4/p75NTR/IL-8 signal pathway may have an important role in EndoMT induced by SFO. Our findings support potential novel targets for the therapeutics of cancer and fibrosis disease. PMID:24905361

  13. Acute administration of a small molecule p75NTR ligand does not prevent hippocampal neuron loss nor development of spontaneous seizures after pilocarpine-induced status epilepticus

    PubMed Central

    Grabenstatter, H.L.; Carlsen, J.; Raol, Y.H.; Yang, T.; Hund, D.; Del Angel, Y. Cruz; White, A.M.; Gonzalez, M.I.; Longo, F.M.; Russek, S.J.; Brooks-Kayal, A.R.

    2014-01-01

    Neurotrophins, such as brain-derived neurotrophic factor (BDNF), are initially expressed in a precursor form (e.g., proBDNF) and cleaved to form mature BDNF (mBDNF). Following pilocarpine-induced status epilepticus (SE), increases in neurotrophins regulate a wide variety of cell signaling pathways including pro-survival and cell-death machinery in a receptor-specific manner. ProBDNF preferentially binds to the p75 neurotrophin receptor (p75NTR), while mBDNF is the major ligand of the tropomyosin related kinase receptor (TrkB). To elucidate a potential role of p75NTR in acute stages of epileptogenesis, rats were injected prior to and at onset of SE with LM11A-31, a small molecule ligand that binds to p75NTR to promote survival signaling and inhibit neuronal cell death. Modulation of early p75NTR signaling and its effects on (1) electrographic SE, (2) SE-induced neurodegeneration, and (3) subsequent spontaneous seizures were examined following LM11A-31 administration. Despite an established neuroprotective effect of LM11A-31 in several animal models of neurodegenerative disorders (e.g., Alzheimer’s disease, traumatic brain injury, and spinal cord injury), high-dose LM11A-31 administration prior to and at onset of SE did not reduce the intensity of electrographic SE, prevent SE-induced neuronal cell injury, nor inhibit the progression of epileptogenesis. Further studies are required to understand the role of p75NTR activation during epileptogenesis and in seizure-induced cell injury in the hippocampus among other potential cellular pathologies contributing to the onset of spontaneous seizures. Additional studies utilizing more prolonged treatment with LM11A-31 are required to reach a definite conclusion on its potential neuroprotective role in epilepsy. PMID:24801281

  14. Prognostic Significance of Single Progesterone Receptor Positivity

    PubMed Central

    Fan, Ying; Ding, Xiaoyan; Xu, Binghe; Ma, Fei; Yuan, Peng; Wang, Jiayu; Zhang, Pin; Li, Qing; Luo, Yang

    2015-01-01

    Abstract Single progesterone receptor positive (PgR+), especially in form of ER−/PgR+/HER2−, is a nonnegligible phenomenon. Little is known about the characteristics and the role of single PgR positive in this phenotype. Therefore, we explore the significance of single PgR positivity by comparing ER−/PgR+/HER2− breast cancers with triple negative breast cancers (TNBCs). Three thousand nine hundred sixty-six cases of primary invasive breast carcinoma operated consecutively from January 2005 to May 2008 in Cancer Hospital, Chinese Academy of Medical Sciences were examined. Two hundred forty (6%) cases were identified as ER−/PgR+/HER2− breast cancers and 348 (8.8%) cases as TNBCs. Clinicopathological characteristics and survivals were analyzed respectively and then compared between 2 subtypes. Compared with patients with TNBCs, ER−/PgR+/HER2− tumor tended to have lower tumor grade (Grade 3: 45.7% vs. 37.5%, P = 0.051) and smaller tumor size (P = 0.036). However, no differences were found between ER−/PgR+/HER2− and TNBC patients in relapse-free survival (RFS) and OS. The 5-year RFS rates were 80.7% and 77.4%, respectively (P = 0.330) and the 5-year OS rates were 88.0% and 85.2%, respectively (P = 0.290). ER−/PgR+/HER2− patients receiving adjuvant endocrine treatment had better RFS (P = 0.016) and overall survival (OS) (P < 0.0001) than patients receiving no endocrine therapy. This exclusive analysis of patients with ER−/PgR+/HER2− breast cancers showed that this subtype exhibited an aggressive behavior as TNBC, suggesting that it should also be regarded as biologically distinctive group and single PgR positive itself is not a good prognostic factor. However, adjuvant endocrine therapy could still benefit this group of patients. Further investigations should be done to elucidate the underlying mechanism. PMID:26579819

  15. Identification of a Linear Epitope in Sortilin That Partakes in Pro-neurotrophin Binding*

    PubMed Central

    Serup Andersen, Olga; Boisguerin, Prisca; Glerup, Simon; Skeldal, Sune; Volkmer, Rudolf; Willnow, Thomas E.; Nykjær, Anders; Andersen, Olav M.

    2010-01-01

    Sortilin acts as a cell surface receptor for pro-neurotrophins (pro-NT) that upon complex formation with the p75 neurotrophin receptor (p75NTR) is able to signal neuronal cell death. Here we screened a sortilin peptide library comprising 16-mer overlapping sequences for binding of the pro-domains of nerve growth factor and brain-derived neurotrophic factor. We find that a linear surface-exposed sequence, 163RIFRSSDFAKNF174, constitutes an important pro-NT binding epitope in sortilin. Systematic mutational analysis revealed residues Arg163, Phe165, Arg166, and Phe170 to be critical for the interaction. Expression of a sortilin mutant in which these four amino acids were substituted by alanines disrupted pro-NT binding without affecting receptor heterodimerization with p75NTR or binding of ligands that selectively engages the centrally located tunnel in the β-propeller of sortilin. We furthermore demonstrate that a peptide comprising the ligand-binding epitope can prevent pro-NT-induced apoptosis in RN22 schwannoma cells. PMID:20159974

  16. Desmoplastic melanoma, neurotropism, and neurotrophin receptors--what we know and what we do not.

    PubMed

    Frydenlund, Noah; Mahalingam, Meera

    2015-07-01

    Desmoplastic melanoma (DM) is a relatively rare cytomorphologic variant of melanoma with a marked propensity for perineural invasion (PNI). Historically, DMs that display PNI have been grouped under the umbrella term of neurotropic melanoma (NM). However, definitions for NM and desmoplastic NM are not consistent in the literature, presenting a barrier to a comprehensive understanding of these lesions. In this review, we parse the literature on DM, NM, and desmoplastic NM, to clarify definitions and ascertain the incidence of PNI, with a view toward understanding its prognostic relevance. Neurotrophins, which represent a family of signaling peptides important to the development and maintenance of the peripheral nervous system, have been implicated in the pathogenesis of PNI in select lineage-unrelated malignancies. Given this, we also detail evidence linking neurotrophins and their receptors (TrkA, RET, p75NGFR, and NCAM) to the pathogenesis of PNI in melanoma. PMID:26050260

  17. Neurotrophin signaling endosomes: biogenesis, regulation, and functions.

    PubMed

    Yamashita, Naoya; Kuruvilla, Rejji

    2016-08-01

    In the nervous system, communication between neurons and their post-synaptic target cells is critical for the formation, refinement and maintenance of functional neuronal connections. Diffusible signals secreted by target tissues, exemplified by the family of neurotrophins, impinge on nerve terminals to influence diverse developmental events including neuronal survival and axonal growth. Key mechanisms of action of target-derived neurotrophins include the cell biological processes of endocytosis and retrograde trafficking of their Trk receptors from growth cones to cell bodies. In this review, we summarize the molecular mechanisms underlying this endosome-mediated signaling, focusing on the instructive role of neurotrophin signaling itself in directing its own trafficking. Recent studies have linked impaired neurotrophin trafficking to neurodevelopmental disorders, highlighting the relevance of neurotrophin endosomes in human health. PMID:27327126

  18. In vitro cementoblast-like differentiation of postmigratory neural crest-derived p75{sup +} stem cells with dental follicle cell conditioned medium

    SciTech Connect

    Wen, Xiujie; Liu, Luchuan; Deng, Manjing; Liu, Rui; Zhang, Li; Nie, Xin

    2015-09-10

    Cranial neural crest-derived cells (CNCCs) play important role in epithelial–mesenchymal interactions during tooth morphogenesis. However, the heterogeneity of CNCCs and their tendency to spontaneously differentiate along smooth muscle or osteoblast lineages in vitro limit further understanding of their biological properties. We studied the differentiation properties of isolated rat embryonic postmigratory CNCCs, expressing p75 neurotrophin receptor (p75NTR). These p75NTR positive (p75{sup +}) CNCCs, isolated using fluorescence activated cell sorter, exhibited fibroblast-like morphology and characteristics of mesenchymal stem cells. Incubation of p75{sup +} CNCCs in dental follicle cell conditioned medium (DFCCM) combined with dentin non-collagenous proteins (dNCPs), altered their morphological features to cementoblast-like appearance. These cells also showed low proliferative activity, high ALP activity and significantly increased calcified nodule formation. Markers related to mineralization or specific to cementoblast lineage were highly expressed in dNCPs/DFCCM-treated p75{sup +} cells, suggesting their differentiation along cementoblast-like lineage. p75{sup +} stem cells selected from postmigratory CNCCs represent a pure stem cell population and could be used as a stem cell model for in vitro studies due to their intrinsic ability to differentiate to neuronal cells and transform from neuroectoderm to ectomesenchyme. They can provide a potential stem cell resource for tooth engineering studies and help to further investigate mechanisms of epithelial–mesenchymal interactions in tooth morphogenesis. - Highlights: • Cranial neural crest-derived cells (CNCCs) take part in tooth morphogenesis. • positive (p75{sup +}) CNCCs are fibroblast-like and resemble mesenchymal stem cells. • p75{sup +} CNCCs in dental follicle cell medium (DFCCM/dNCP) appear like cementoblasts. • DFCCM/dNCP-treated p75{sup +} cells express cementoblast specific mineralization

  19. Neurotrophins and spinal circuit function

    PubMed Central

    Boyce, Vanessa S.; Mendell, Lorne M.

    2014-01-01

    Work early in the last century emphasized the stereotyped activity of spinal circuits based on studies of reflexes. However, the last several decades have focused on the plasticity of these spinal circuits. These considerations began with studies of the effects of monoamines on descending and reflex circuits. In recent years new classes of compounds called growth factors that are found in peripheral nerves and the spinal cord have been shown to affect circuit behavior in the spinal cord. In this review we will focus on the effects of neurotrophins, particularly nerve growth factor (NGF), brain derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3), on spinal circuits. We also discuss evidence that these molecules can modify functions including nociceptive behavior, motor reflexes and stepping behavior. Since these substances and their receptors are normally present in the spinal cord, they could potentially be useful in improving function in disease states and after injury. Here we review recent findings relevant to these translational issues. PMID:24926235

  20. Neurotrophins and the control of axonal outgrowth.

    PubMed

    Tucker, K L

    2002-12-01

    The neurotrophins NGF, BDNF, NT-3, and NT-4/5 are well known for their neuron survival-promoting functions. This review focuses upon a less-investigated function of this gene family, namely that of controlling the growth of axons in vivo. Recent evidence is discussed that reveals a definitive requirement for neurotrophin signaling in the elongation of peripheral nerves during embryonic development. PMID:12434114

  1. Neurotrophins, their receptors and KI-67 in human GH-secreting pituitary adenomas: an immunohistochemical analysis.

    PubMed

    Artico, M; Bianchi, E; Magliulo, G; De Vincentiis, M; De Santis, E; Orlandi, A; Santoro, A; Pastore, F S; Giangaspero, F; Caruso, R; Re, M; Fumagalli, L

    2012-01-01

    Pituitary adenomas are a diverse group of tumors arising from the pituitary gland. Typically, they are small, slow-growing, hormonally inactive lesions that come to light as incidental findings on radiologic or postmortem examinations, although some small, slow-growing lesions with excessive hormonal activity may manifest with a clinical syndrome. The family of neurotrophins plays a key role in the development and maintenance of the pituitary endocrine cell function and in the regulation of hypothalamo-pituitary-adrenocortical axis activity. The objective of our experimental study is to investigate the localization of the neurotrophins, their relative receptors and to detect the expression level of Ki-67 to determine whether all these factors participate in the transformation and development of human pituitary adenomas. A very strong expression of Neurotrophin-3 (NT-3) and its receptor TrKC was observed in the extracellular matrix (ECM) and vessel endothelium, together with a clear/marked presence of Brain-derived neurotrophic factor (BDNF), and its receptor TrKB, thus confirming their direct involvement in the progression of pituitary adenomas. On the contrary, NGF (Nerve growth factor) and its receptor TrKA and p75NTR were weakly expressed in the epithelial gland cells and the ECM. PMID:22507324

  2. Neurotrophins and their receptors in human lingual tonsil: an immunohistochemical analysis.

    PubMed

    Artico, Marco; Bronzetti, Elena; Felici, Laura M; Alicino, Valentina; Ionta, Brunella; Bronzetti, Benedetto; Magliulo, Giuseppe; Grande, Claudia; Zamai, Loris; Pasquantonio, Guido; De Vincentiis, Marco

    2008-11-01

    Lymphoid organs are supplied by many nerve endings associated with different kinds of cells and macrophages. The role of this innervation on the release of locally active molecules is still unclear. Lingual tonsils belong to Waldeyer's Ring, in close association with palatine tonsils and nasopharyngeal (adenoids) tonsils, thus constituting part of NALT (nasal-associated lymphoid tissue) together with the tubal tonsils and lateral pharyngeal bands. In this study, we focused our attention on the expression of some neurotrophins (NTs) and their high- and low-affinity receptors in human lingual tonsils. Light immunohistochemistry showed that human tonsillar samples were generally positive for all the NTs investigated (NGF, BDNF, NT-3, NT-4) and their receptors (TrKA, TrKB, TrKC and p75) with some different expression levels. NGF and TrKC were strongly expressed in macrophages, but weakly in lymphocytes. However, BDNF and TrKB was highly expressed in lymphocytes and weaker in macrophages. The low-affinity receptor for NGF, p75, was mainly moderately expressed in the analysed samples. These results suggest the presence of a pattern of neurotrophin innervation in the human lingual tonsil which may play a role in sustaining inflammatory conditions and in modulating a close interaction between the nervous system and the different immune cellular subtypes. PMID:18949422

  3. Amelioration of Cisplatin-Induced Experimental Peripheral Neuropathy by a Small Molecule Targeting p75NTR

    PubMed Central

    Friesland, Amy; Weng, Zhiying; Duenas, Maria; Massa, Stephen M.; Longo, Frank M.; Lu, Qun

    2014-01-01

    Cisplatin is an effective and widely used first-line chemotherapeutic drug for treating cancers. However, many patients sustain cisplatin-induced peripheral neuropathy (CIPN), often leading to a reduction in drug dosages or complete cessation of treatment altogether. Therefore, it is important to understand cisplatin mechanisms in peripheral nerve tissue mediating its toxicity and identify signaling pathways for potential intervention. Rho GTPase activation is increased following trauma in several models of neuronal injury. Thus, we investigated whether components of the Rho signaling pathway represent important neuroprotective targets with the potential to ameliorate CIPN and thereby optimize current chemotherapy treatment regimens. We have developed a novel CIPN model in the mouse. Using this model and primary neuronal culture, we determined whether LM11A-31, a small-molecule, orally bioavailable ligand of the p75 neurotrophin receptor (p75NTR), can modulate Rho GTPase signaling and reduce CIPN. Von Frey filament analysis of sural nerve function showed that LM11A-31 treatment prevented decreases in peripheral nerve sensation seen with cisplatin treatment. Morphometric analysis of harvested sural nerves revealed that cisplatin-induced abnormal nerve fiber morphology and the decreases in fiber area were alleviated with concurrent LM11A-31 treatment. Cisplatin treatment increased RhoA activity accompanied by the reduced tyrosine phosphorylation of SHP-2, which was reversed by LM11A-31. LM11A-31 also countered the effects of calpeptin, which activated RhoA by inhibiting SHP-2 tyrosine phosphatase. Therefore, suppression of RhoA signaling by LM11A-31 that blocks proNGF binding to p75NTR or activates SHP-2 tyrosine phosphatase downstream of NGF receptor enhances neuroprotection in experimental CIPN in mouse model. PMID:25277379

  4. Functional interactions between steroid hormones and neurotrophin BDNF.

    PubMed

    Numakawa, Tadahiro; Yokomaku, Daisaku; Richards, Misty; Hori, Hiroaki; Adachi, Naoki; Kunugi, Hiroshi

    2010-05-26

    Brain-derived neurotrophic factor (BDNF), a critical neurotrophin, regulates many neuronal aspects including cell differentiation, cell survival, neurotransmission, and synaptic plasticity in the central nervous system (CNS). Though BDNF has two types of receptors, high affinity tropomyosin-related kinase (Trk)B and low affinity p75 receptors, BDNF positively exerts its biological effects on neurons via activation of TrkB and of resultant intracellular signaling cascades including mitogen-activated protein kinase/extracellular signal-regulated protein kinase, phospholipase Cγ, and phosphoinositide 3-kinase pathways. Notably, it is possible that alteration in the expression and/or function of BDNF in the CNS is involved in the pathophysiology of various brain diseases such as stroke, Parkinson's disease, Alzheimer's disease, and mental disorders. On the other hand, glucocorticoids, stress-induced steroid hormones, also putatively contribute to the pathophysiology of depression. Interestingly, in addition to the reduction in BDNF levels due to increased glucocorticoid exposure, current reports demonstrate possible interactions between glucocorticoids and BDNF-mediated neuronal functions. Other steroid hormones, such as estrogen, are involved in not only sexual differentiation in the brain, but also numerous neuronal events including cell survival and synaptic plasticity. Furthermore, it is well known that estrogen plays a role in the pathophysiology of Parkinson's disease, Alzheimer's disease, and mental illness, while serving to regulate BDNF expression and/or function. Here, we present a broad overview of the current knowledge concerning the association between BDNF expression/function and steroid hormones (glucocorticoids and estrogen). PMID:21540998

  5. Small Molecule p75NTR Ligands Reduce Pathological Phosphorylation and Misfolding of Tau, Inflammatory Changes, Cholinergic Degeneration, and Cognitive Deficits in AβPPL/S Transgenic Mice

    PubMed Central

    Nguyen, Thuy-Vi V.; Shen, Lin; Griend, Lilith Vander; Quach, Lisa N.; Belichenko, Nadia P.; Saw, Nay; Yang, Tao; Shamloo, Mehrdad; Wyss-Coray, Tony; Massa, Stephen M.; Longo, Frank M.

    2014-01-01

    The p75 neurotrophin receptor (p75NTR ) is involved in degenerative mechanisms related to Alzheimer’s disease (AD). In addition, p75NTR levels are increased in AD and the receptor is expressed by neurons that are particularly vulnerable in the disease. Therefore, modulating p75NTR function may be a significant disease-modifying treatment approach. Prior studies indicated that the non-peptide, small molecule p75NTR ligands LM11A-31, and chemically unrelated LM11A-24, could block amyloid-β-induced deleterious signaling and neurodegeneration in vitro, and LM11A-31 was found to mitigate neuritic degeneration and behavioral deficits in a mouse model of AD. In this study, we determined whether these in vivo findings represent class effects of p75NTR ligands by examining LM11A-24 effects. In addition, the range of compound effects was further examined by evaluating tau pathology and neuroinflammation. Following oral administration, both ligands reached brain concentrations known to provide neuroprotection in vitro. Compound induction of p75NTR cleavage provided evidence for CNS target engagement. LM11A-31 and LM11A-24 reduced excessive phosphorylation of tau, and LM11A-31 also inhibited its aberrant folding. Both ligands decreased activation of microglia, while LM11A-31 attenuated reactive astrocytes. Along with decreased inflammatory responses, both ligands reduced cholinergic neurite degeneration. In addition to the amelioration of neuropathology in AD model mice, LM11A-31, but not LM11A-24, prevented impairments in water maze performance, while both ligands prevented deficits in fear conditioning. These findings support a role for p75NTR ligands in preventing fundamental tau-related pathologic mechanisms in AD, and further validate the development of these small molecules as a new class of therapeutic compounds. PMID:24898660

  6. SORT1 Mutation Resulting in Sortilin Deficiency and p75(NTR) Upregulation in a Family With Essential Tremor.

    PubMed

    Sánchez, Elena; Bergareche, Alberto; Krebs, Catharine E; Gorostidi, Ana; Makarov, Vladimir; Ruiz-Martinez, Javier; Chorny, Alejo; Lopez de Munain, Adolfo; Marti-Masso, Jose Felix; Paisán-Ruiz, Coro

    2015-01-01

    *These authors contributed equally to this work.Essential tremor (ET) is the most prevalent movement disorder affecting millions of people in the United States. Although a positive family history is one of the most important risk factors for ET, the genetic causes of ET remain unknown. In this study, whole exome sequencing and subsequent approaches were performed in a family with an autosomal dominant form of early-onset ET. Functional analyses including mutagenesis, cell culture, gene expression, enzyme-linked immunosorbent, and apoptosis assays were also performed. A disease-segregating mutation (p.Gly171Ala), absent in normal population, was identified in the SORT1 gene. The p.Gly171Ala mutation was shown not only to impair the expression of its encoding protein sortilin but also the mRNA levels of its binding partner p75 neurotrophin receptor that is known to be implicated in brain injury, neuronal apoptosis, and neurotransmission. PMID:26297037

  7. SORT1 Mutation Resulting in Sortilin Deficiency and p75NTR Upregulation in a Family With Essential Tremor

    PubMed Central

    Sánchez, Elena; Bergareche, Alberto; Krebs, Catharine E.; Gorostidi, Ana; Makarov, Vladimir; Ruiz-Martinez, Javier; Chorny, Alejo; Lopez de Munain, Adolfo; Marti-Masso, Jose Felix

    2015-01-01

    *These authors contributed equally to this work.Essential tremor (ET) is the most prevalent movement disorder affecting millions of people in the United States. Although a positive family history is one of the most important risk factors for ET, the genetic causes of ET remain unknown. In this study, whole exome sequencing and subsequent approaches were performed in a family with an autosomal dominant form of early-onset ET. Functional analyses including mutagenesis, cell culture, gene expression, enzyme-linked immunosorbent, and apoptosis assays were also performed. A disease-segregating mutation (p.Gly171Ala), absent in normal population, was identified in the SORT1 gene. The p.Gly171Ala mutation was shown not only to impair the expression of its encoding protein sortilin but also the mRNA levels of its binding partner p75 neurotrophin receptor that is known to be implicated in brain injury, neuronal apoptosis, and neurotransmission. PMID:26297037

  8. Impact of a deletion of the full-length and short isoform of p75NTR on cholinergic innervation and the population of postmitotic doublecortin positive cells in the dentate gyrus

    PubMed Central

    Poser, Robert; Dokter, Martin; von Bohlen und Halbach, Viola; Berger, Stefan M.; Busch, Ruben; Baldus, Marian; Unsicker, Klaus; von Bohlen und Halbach, Oliver

    2015-01-01

    Analyses of mice carrying a deletion of the pan-neurotrophin receptor p75NTR have allowed identifying p75NTR as an important structural regulator of the hippocampus. Most of the previous analyses were done using p75NTRExIII knockout mice which still express the short isoform of p75NTR. To scrutinize the role of p75NTR in the hippocampus, we analyzed adult and aged p75NTRExIV knockout mice, in which both, the short and the full-length isoform are deleted. Deletion of these isoforms induced morphological alterations in the adult dentate gyrus (DG), leading to an increase in the thickness of the molecular and granular layer. Based on these observations, we next determined the morphological substrates that might contribute to this phenotype. The cholinergic innervation of the molecular and granular layer of the DG was found to be significantly increased in the knockout mice. Furthermore, adult neurogenesis in the DG was found to be significantly altered with increased numbers of doublecortin (DCX) positive cells and reduced numbers of apoptotic cells in p75NTRExIV knockout mice. However, cell proliferation as measured by phosphohiston H3 (PH3) positive cell numbers was not affected. These morphological alterations (number of DCX-positive cells and increased cholinergic fiber densities) as well as reduced cell death in the DG are likely to contribute to the observed thickening of the granular layer in p75NTRExIV knockout mice. In addition, Sholl-analysis of DCX-positive neurons revealed a higher dendritic complexity and could thus be a possible morphological correlate for the increased thickness of the molecular layer in p75NTR deficient animals. Our data clearly demonstrate that deletion of both, the short and the full-length isoform of p75NTR affects DG morphology, due to alterations of the cholinergic system and an imbalance between neurogenesis and programmed cell death within the subgranular zone. PMID:26074780

  9. Studies of neurotrophin biology in the developing trigeminal system

    PubMed Central

    DAVIES, ALUN M.

    1997-01-01

    The accessibility of the primary sensory neurons of the trigeminal system at stages throughout their development in avian and mammalian embryos and the ease with which these neurons can be studied in vivo has facilitated investigation of several fundamental aspects of neurotrophin biology. Studies of the timing and sequence of action of neurotrophins and the expression of neurotrophins and their receptors in this well characterised neuronal system have led to a detailed understanding of the functions of neurotrophins in neuronal development. The concepts of neurotrophin independent survival, neurotrophin switching and neurotrophin cooperativity have largely arisen from work on the trigeminal system. Moreover, in vitro studies of trigeminal neurons provided some of the first evidence that the neurotrophin requirements of sensory neurons are related to sensory modality. The developing trigeminal system has been studied most extensively in mice and chickens, each of which has particular advantages for understanding different aspects of neurotrophin biology. In this review, I will outline these advantages and describe some of the main findings that have arisen from this work. PMID:9449067

  10. Ameliorative Effects of p75NTR-ED-Fc on Axonal Regeneration and Functional Recovery in Spinal Cord-Injured Rats.

    PubMed

    Wang, Yong-Tang; Lu, Xiu-Min; Zhu, Feng; Huang, Peng; Yu, Ying; Long, Zai-Yun; Wu, Ya-Min

    2015-12-01

    As a co-receptor of Nogo-66 receptor (NgR) and a critical receptor for paired immunoglobulin-like receptor (PirB), p75 neurotrophin receptor (p75NTR) mediates the inhibitory effects of myelin-associated inhibitors on axonal regeneration after spinal cord injury. Therefore, the p75NTR antagonist, such as recombinant p75NTR protein or its homogenates may block the inhibitory effects of myelin and promote the axonal regeneration and functional recovery. The purposes of this study are to subclone and express the extracellular domain gene of human p75NTR with IgG-Fc (hp75NTR-ED-Fc) in prokaryotic expression system and investigate the effects of the recombinant protein on axonal regeneration and functional recovery in spinal cord-injured rats. The hp75NTR-ED-Fc coding sequence was amplified from pcDNA-hp75NTR-ED-Fc by polymerase chain reaction (PCR) and subcloned into vector pET32a (+), then the effects of the purified recombinant protein on neurite outgrowth of dorsal root ganglion (DRG) neurons cultured with myelin-associated glycoprotein (MAG) were determined, and the effects of the fusion protein on axonal regeneration, functional recovery, and its possible mechanisms in spinal cord-injured rats were further investigated. The results indicated that the purified infusion protein could promote neurite outgrowth of DRG neurons, promote axonal regeneration and functional recovery, and decrease RhoA activation in spinal cord-injured rats. Taken together, the findings revealed that p75NTR still may be a potential and novel target for therapeutic intervention for spinal cord injury and that the hp75NTR-ED-Fc fusion protein treatment enhances functional recovery by limiting tissue loss and stimulating axonal growth in spinal cord-injured rats, which may result from decreasing the activation of RhoA. PMID:25394381

  11. Changes in expression of BDNF and its receptors TrkB and p75NTR in the hippocampus of a dog model of chronic alcoholism and abstinence.

    PubMed

    Xu, R; Duan, S R; Zhao, J W; Wang, C Y

    2015-08-01

    Chronic ethanol consumption can produce learning and memory deficits. Brain-derived neurotrophic factor (BDNF) and its receptors affect the pathogenesis of alcoholism. In this study, we examined the expression of BDNF, tropomyosin receptor kinase B (TrkB) and p75 neurotrophin receptor (p75NTR) in the hippocampus of a dog model of chronic alcoholism and abstinence. Twenty domestic dogs (9-10 months old, 15-20 kg; 10 males and 10 females) were obtained from Harbin Medical University. A stable alcoholism model was established through ad libitum feeding, and anti-alcohol drug treatment (Zhong Yao Jie Jiu Ling, the main ingredient was the stems of watermelon; developed in our laboratory), at low- and high-doses, was carried out. The Zhong Yao Jie Jiu Ling was effective for the alcoholism in dogs. The morphology of hippocampal neurons was evaluated using hematoxylin-eosin staining. The number and morphological features of BDNF, TrkB and p75NTR-positive neurons in the dentate gyrus (DG), and the CA1, CA3 and CA4 regions of the hippocampus were observed using immunohistochemistry. One-way ANOVA was used to determine differences in BDNF, TrkB and p75NTR expression. BDNF, TrkB and p75NTR-positive cells were mainly localized in the granular cell layer of the DG and in the pyramidal cell layer of the CA1, CA3 and CA4 regions (DG>CA1>CA3>CA4). Expression levels of both BDNF and TrkB were decreased in chronic alcoholism, and increased after abstinence. The CA4 region appeared to show the greatest differences. Changes in p75NTR expression were the opposite of those of BDNF and TrkB, with the greatest differences observed in the DG and CA4 regions. PMID:26108098

  12. Neurotrophin and neurotrophin receptor proteins in medulloblastomas and other primitive neuroectodermal tumors of the pediatric central nervous system.

    PubMed Central

    Washiyama, K.; Muragaki, Y.; Rorke, L. B.; Lee, V. M.; Feinstein, S. C.; Radeke, M. J.; Blumberg, D.; Kaplan, D. R.; Trojanowski, J. Q.

    1996-01-01

    Primitive neuroectodermal tumors (PNETs) of the central nervous system (CNS) are poorly understood childhood neoplasms, and medulloblastomas are the most common pediatric PNETs. Neoplastic cells in medulloblastomas and other PNETs resemble progenitor cells of the developing central nervous system, but they also may exhibit the molecular phenotype of immature neurons or glia. As neurotrophins play a role in regulating differentiation, proliferation, and cell death in the normal developing central nervous system, and recent evidence suggests that neurotrophins may influence the behavior of medulloblastomas, we studied 29 PNET biopsy samples (27 of which were posterior fossa medulloblastomas) by immunobistochemistry using antibodies specific for each of the major high affinity neurotrophin receptor proteins, ie, TrkA, TrkB, and TrkC. A subset of these tumors also was examined by Western blot. Immunoreactive TrkA, TrkB, and TrkC were observed in neoplastic cells in 8 (27%), 18 (62%), and 14 (48%) of these PNETs, respectively. Additional immunohistochemical studies of a subset of these PNETs using antibodies to neurotrophins that primarily activate TrkB and TrkC, ie, brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4/5, showed that immunoreactive brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4/5 were detected in 22, 9, and 19% of these PNET biopsies, respectively. Finally, 19 pediatric brain tumors other than these PNETs also were studied here, and they expressed these neurotrophins and their receptors to a variable extent. The demonstration here that neurotrophins and their cognate receptor proteins are expressed in PNETs as well as in other pediatric brain tumors may imply that signal transduction pathways mediated by neurotrophins and/or their receptors influence the induction or progression of these common childhood neoplasms. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:8774147

  13. The trk family of receptors mediates nerve growth factor and neurotrophin-3 effects in melanocytes.

    PubMed Central

    Yaar, M; Eller, M S; DiBenedetto, P; Reenstra, W R; Zhai, S; McQuaid, T; Archambault, M; Gilchrest, B A

    1994-01-01

    We have recently shown that (a) human melanocytes express the p75 nerve growth factor (NGF) receptor in vitro; (b) that melanocyte dendricity and migration, among other behaviors, are regulated at least in part by NGF; and (c) that cultured human epidermal keratinocytes produce NGF. We now report that melanocyte stimulation with phorbol 12-tetra decanoate 13-acetate (TPA), previously reported to induce p75 NGF receptor, also induces trk in melanocytes, and TPA effect is further potentiated by the presence of keratinocytes in culture. Moreover, trk in melanocytes becomes phosphorylated within minutes after NGF stimulation. As well, cultures of dermal fibroblasts express neurotrophin-3 (NT-3) mRNA; NT-3 mRNA levels in cultured fibroblasts are modulated by mitogenic stimulation, UV irradiation, and exposure to melanocyte-conditioned medium. Moreover, melanocytes constitutively express low levels of trk-C, and its expression is downregulated after TPA stimulation. NT-3 supplementation to cultured melanocytes maintained in Medium 199 alone prevents cell death. These combined data suggest that melanocyte behavior in human skin may be influenced by neurotrophic factors, possibly of keratinocyte and fibroblast origin, which act through high affinity receptors. Images PMID:7929831

  14. Drosophila Neurotrophins Reveal a Common Mechanism for Nervous System Formation

    PubMed Central

    McQuilton, Peter; Forero, Manuel G; Mizuguchi, Kenji; Sutcliffe, Ben; Gu, Chun-Jing; Fenton, Janine C; Hidalgo, Alicia

    2008-01-01

    Neurotrophic interactions occur in Drosophila, but to date, no neurotrophic factor had been found. Neurotrophins are the main vertebrate secreted signalling molecules that link nervous system structure and function: they regulate neuronal survival, targeting, synaptic plasticity, memory and cognition. We have identified a neurotrophic factor in flies, Drosophila Neurotrophin (DNT1), structurally related to all known neurotrophins and highly conserved in insects. By investigating with genetics the consequences of removing DNT1 or adding it in excess, we show that DNT1 maintains neuronal survival, as more neurons die in DNT1 mutants and expression of DNT1 rescues naturally occurring cell death, and it enables targeting by motor neurons. We show that Spätzle and a further fly neurotrophin superfamily member, DNT2, also have neurotrophic functions in flies. Our findings imply that most likely a neurotrophin was present in the common ancestor of all bilateral organisms, giving rise to invertebrate and vertebrate neurotrophins through gene or whole-genome duplications. This work provides a missing link between aspects of neuronal function in flies and vertebrates, and it opens the opportunity to use Drosophila to investigate further aspects of neurotrophin function and to model related diseases. PMID:19018662

  15. GABAB Receptor-Positive Modulators: Brain Region-Dependent Effects

    PubMed Central

    Advani, Tushar; Burke, Teresa F.; Cheng, Kejun; Rice, Kenner C.; Koek, Wouter

    2012-01-01

    This study examined the positive modulatory properties of 2,6-di-tert-butyl-4-(3-hydroxy-2,2-dimethyl-propyl)-phenol (CGP7930) and (R,S)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3H-benzofuran-2-one (rac-BHFF) at γ-aminobutyric acid B (GABAB) receptors in different brain regions. Using quantitative autoradiography, we measured GABAB receptor-stimulated binding of guanosine 5′-O-(3-[35S]thiotriphosphate) ([35S]GTPγS) to G proteins in medial prefrontal cortex (mPFC), hippocampus, and cerebellum. CGP7930 and rac-BHFF enhanced baclofen-stimulated [35S]GTPγS binding similarly in mPFC and hippocampus, but were more effective in cerebellum. CGP7930 (100 μM) increased [35S]GTPγS binding stimulated by baclofen (30 μM) from 29 to 241% above basal in mPFC and from 13 to 1530% above basal in cerebellum. Likewise, rac-BHFF (10 μM) increased baclofen-stimulated [35S]GTPγS binding more in cerebellum (from 13 to 1778% above basal) than in mPFC (from 29 to 514% above basal). rac-BHFF (10 μM) in combination with γ-hydroxybutyrate (20 mM) increased [35S]GTPγS binding in cerebellum but not in mPFC. rac-BHFF also enhanced the effects of 3-aminopropyl(diethoxymethyl)phosphinic acid (CGP35348). Consistent with its partial agonist properties, CGP35348 stimulated [35S]GTPγS binding in mPFC when given alone (to 18% above basal), but less extensively than baclofen (140% above basal), and antagonized baclofen when given together. CGP35348 (1 mM) in combination with rac-BHFF (100 μM) produced an increase in [35S]GTPγS binding that was larger in cerebellum (from 61 to 1260% above basal) than in mPFC (from 18 to 118% above basal). Taken together, the results show that GABAB receptor-positive modulators enhance [35S]GTPγS binding stimulated by GABAB receptor agonists in a brain region-dependent manner. This regionally selective enhancement is further evidence of pharmacologically distinct GABAB receptor populations, possibly allowing for more selective therapeutic targeting

  16. Fulvestrant radiosensitizes human estrogen receptor-positive breast cancer cells

    SciTech Connect

    Wang, Jing; Yang, Qifeng; Haffty, Bruce G.; Li, Xiaoyan; Moran, Meena S.

    2013-02-08

    Highlights: ► Fulvestrant radiosensitizes MCF-7 cells. ► Fulvestrant increases G1 arrest and decreases S phase in MCF-7 cells. ► Fulvestrant down-regulates DNA-PKcs and RAD51 in MCF-7 cells. -- Abstract: The optimal sequencing for hormonal therapy and radiation are yet to be determined. We utilized fulvestrant, which is showing promise as an alternative to other agents in the clinical setting of hormonal therapy, to assess the cellular effects of concomitant anti-estrogen therapy (fulvestrant) with radiation (F + RT). This study was conducted to assess the effects of fulvestrant alone vs. F + RT on hormone-receptor positive breast cancer to determine if any positive or negative combined effects exist. The effects of F + RT on human breast cancer cells were assessed using MCF-7 clonogenic and tetrazolium salt colorimetric (MTT) assays. The assays were irradiated with a dose of 0, 2, 4, 6 Gy ± fulvestrant. The effects of F + RT vs. single adjuvant treatment alone on cell-cycle distribution were assessed using flow cytometry; relative expression of repair proteins (Ku70, Ku80, DNA-PKcs, Rad51) was assessed using Western Blot analysis. Cell growth for radiation alone vs. F + RT was 0.885 ± 0.013 vs. 0.622 ± 0.029 @2 Gy, 0.599 ± 0.045 vs. 0.475 ± 0.054 @4 Gy, and 0.472 ± 0.021 vs. 0.380 ± 0.018 @6 Gy RT (p = 0.003). While irradiation alone induced G2/M cell cycle arrest, the combination of F + RT induced cell redistribution in the G1 phase and produced a significant decrease in the proportion of cells in G2 phase arrest and in the S phase in breast cancer cells (p < 0.01). Furthermore, levels of repair proteins DNA-PKcs and Rad51 were significantly decreased in the cells treated with F + RT compared with irradiation alone. F + RT leads to a decrease in the surviving fraction, increased cell cycle arrest, down regulating of nonhomologous repair protein DNA-PKcs and homologous recombination repair protein RAD51. Thus, our findings suggest that F + RT

  17. Serum Neurotrophin Profile in Systemic Sclerosis

    PubMed Central

    Lise, Marie-Claude; Sparsa, Agnès; Marie, Isabelle; Lalloué, Fabrice; Ly, Kim; Martel, Clothilde; Bezanahary, Holy; Gondran, Guillaume; Loustaud-Ratti, Véronique; Bonnetblanc, Jean-Marie; Vidal, Elisabeth; Jauberteau, Marie-Odile; Fauchais, Anne-Laure

    2010-01-01

    Background Neurotrophins (NTs) are able to activate lymphocytes and fibroblasts; they can modulate angiogenesis and sympathic vascular function. Thus, they can be implicated in the three pathogenic processes of systemic sclerosis (SSc). The aims of this study are to determine blood levels of Nerve Growth Factor (NGF), Brain-Derived Neurotrophic Factor (BDNF) and Neurotrophin-3 (NT-3) in SSc and to correlate them with clinical and biological data. Methods Serum samples were obtained from 55 SSc patients and 32 control subjects to measure NTs levels by ELISA and to determine their relationships with SSc profiles. Findings Serum NGF levels were higher in SSc patients (288.26±170.34 pg/mL) than in control subjects (170.34±50.8 pg/mL, p<0.001) and correlated with gammaglobulins levels and the presence of both anti-cardiolipin and anti-Scl-70 antibodies (p<0.05). In contrast, BDNF levels were lower in SSc patients than in controls (1121.9±158.1 vs 1372.9±190.9 pg/mL, p<0.0001), especially in pulmonary arterial hypertension and diffuse SSc as compared to limited forms (all p<0.05). NT-3 levels were similar in SSc and in the control group (2657.2±2296 vs 2959.3±2555 pg/mL, NS). BDNF levels correlated negatively with increased NGF levels in the SSc group (and not in controls). Conclusion Low BDNF serum levels were not previously documented in SSc, particularly in the diffuse SSc subset and in patients with pulmonary hypertension or anti-Scl-70 antibodies. The negative correlation between NGF and BDNF levels observed in SSc and not in healthy controls could be implicated in sympathic vascular dysfunction in SSc. PMID:21085492

  18. Brain-derived neurotrophic factor: the neurotrophin hypothesis of psychopathology.

    PubMed

    Stein, Dan J; Daniels, Willie M U; Savitz, Jonathan; Harvey, Brian H

    2008-11-01

    While monoaminergic hypotheses of psychopathology remain popular, there has been growing interest in the role of neurotrophins in neuropsychiatric disorders. Basic laboratory work has documented the importance of neurotrophins in neuronal survival and synaptic plasticity, and a range of clinical studies has provided analogous evidence of their role in neuropathology. Work on gene variants in brain-derived neurotrophic factor, and associated changes in structural and function brain imaging, have further contributed to our understanding of this area. Much remains to be done to delineate fully the relevant mechanisms by which brain-derived neurotrophic factor and other neurotrophins contribute to psychopathology, and to develop targeted therapeutic interventions. Nevertheless, the neurotrophin hypothesis has already given impetus to a range of valuable research. PMID:19037180

  19. Neurotrophin regulation of neural circuit development and function.

    PubMed

    Park, Hyungju; Poo, Mu-ming

    2013-01-01

    Brain-derived neurotrophic factor (BDNF)--a member of a small family of secreted proteins that includes nerve growth factor, neurotrophin 3 and neurotrophin 4--has emerged as a key regulator of neural circuit development and function. The expression, secretion and actions of BDNF are directly controlled by neural activity, and secreted BDNF is capable of mediating many activity-dependent processes in the mammalian brain, including neuronal differentiation and growth, synapse formation and plasticity, and higher cognitive functions. This Review summarizes some of the recent progress in understanding the cellular and molecular mechanisms underlying neurotrophin regulation of neural circuits. The focus of the article is on BDNF, as this is the most widely expressed and studied neurotrophin in the mammalian brain. PMID:23254191

  20. Immunohistochemical profile of some neurotransmitters and neurotrophins in the seminiferous tubules of rats treated by lonidamine.

    PubMed

    Artico, M; Bronzetti, E; Saso, L; Felici, L M; D'Ambrosio, A; Forte, F; Grande, C; Ortolani, F

    2007-01-01

    Lonidamine (LND) or [1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxylic acid] is an anticancer and antispermatogenic drug that exerts a large number of effects on tumor cells and germ cells. Sexually mature male Sprague-Dawley rats were housed at 22 degrees C on a 12-h light/12-h dark cycle 1 week before the experiments, with free access to food and water. LND was suspended in 0.5% methylcellulose at a concentration of 10 mg/mL and administered orally at the dose of 10 mL/kg (b.w.) as a single dose. Control rats received an equal amount of vehicle. Testes were removed, fixed for 24 h in 2% glutaraldehyde and 2% paraformaldehyde in 0.1 M sodium phosphate (pH 7.2 at 22 degrees C), rinsed with the same buffer, and stored at room temperature. From each sample, a block of tissue was removed by sectioning through the organ. After dehydration in ethanol at increasing concentrations (70-100%), each block was embedded in paraffin and serial 5 mm thick sections were cut using a rotatory microtome. The immunoreactivity for NTs has been observed in spermatogonia of untreated rats, while the rats treated with LND showed an immunohistochemical localization in all the stages of germinal cells. The generally well-expressed immunoreactivity for the neurotrophins receptors in treated rats observed in our study is presumably attributable to alterations of the receptors' structure and/or expression leading to changes of the activity, affinity, localization or protein interactions that may depend on sensitization of ion channels (induced by LND). Neurotrophins (NTs) appear to be interesting proteins for the modulation of sperm maturation and motility with a prominent role for the nerve growth factor (NGF), that may exert an autocrine or paracrine role. We therefore investigated the location and distribution of immunoreactivity for some neurotransmitters (SP, VIP, CGRP, nNOS, Chat), neurotrophins (NGF, BDNF, NT-3) and their own receptors (TrKA, TrKB, TrKC, p75) in the seminiferous tubules

  1. Brain-derived neurotrophic factor, neurotrophin-3 and neurotrophin-4/5 maintain functional tolerance to ethanol.

    PubMed

    Szabò, G; Hoffman, P L

    1995-12-01

    Neurotrophins and growth factors not only affect neuronal development, but also maintain neuronal survival and influence neuronal function in the adult brain, and affect various cognitive processes related to learning and memory. Functional tolerance to ethanol represents an adaptive change in the central nervous system that has been hypothesized to have mechanisms in common with those underlying learning or memory. In the present work, the effects of neurotrophins on ethanol tolerance were compared to the effect of the neuropeptide, arginine vasopressin, which maintains (reduces the rate of dissipation of) both ethanol tolerance and memory. Functional tolerance to ethanol was induced in C57BL/6J mice by feeding them an ethanol-containing liquid diet, and the effect of neurotrophins on the rate of dissipation of tolerance to the hypnotic effect of ethanol was assessed. Human recombinant brain-derived neutrophic factor, neurotrophin-3 and neurotrophin-4/5, injected intracerebroventricularly once daily following ethanol withdrawal, maintained ethanol tolerance, while tolerance dissipated in ethanol-fed mice injected with vehicle (artificial cerebrospinal fluid) or with basic fibroblast growth factor. The results demonstrate that some neurotrophins can modulate neuroadaptation to ethanol, supporting the hypothesis that these factors can influence the function of postmitotic neurons in the adult brain. PMID:8666023

  2. Human gallbladder carcinoma: Role of neurotrophins, MIB-1, CD34 and CA15-3.

    PubMed

    Artico, M; Bronzetti, E; Alicino, V; Ionta, B; Bosco, S; Grande, C; Bruno, M; Tranquilli Leali, F M; Ionta, G; Fumagalli, L

    2010-01-01

    Gallbladder carcinoma is the most common biliary tract tumor and the fifth most common gastrointestinal tract cancer .The prognosis of gallbladder carcinoma is poor and less than 5% of the patients are still alive five years postoperatively. Gallbladder specimens were obtained during surgical operations performed in eleven patients for resection of a gallbladder carcinoma, and during five autopsies (control cases selected among patients who died from for other causes, excluding those suffering from biliary or hepatic diseases). Immunohistochemical characterization and distribution of neurotrophins, with their respective receptors, were analyzed. The actual role played by these neurotrophic factors in the general regulation, vascular permeability, algic responsiveness, release of locally active substances and potential tumorigenesis in the gallbladder and biliary ducts compartment remains controversial. Our study revealed an increased immunohistochemical expression of NGF and TrKA in the epithelium and in the epithelial glands of the gallbladder carcinoma together with an evident immunoreactivity for BDNF in the same neoplastic areas. An evident immunoreactivity for NGF, TrKA and BDNF was observed in control specimens of gallbladder obtained during autopsies, whereas a weak or quite absent immunoreactivity was observed in the same specimens for NT4, TrKC and p75. On the contrary an appreciable immunoreactivity for p75 was observed in the specimens harvested from patients with gallbladder carcinoma. We also investigated the expression of some known tumor markers such as MIB-1 (anti Ki-67), CD34 and CA15-3, to identify a possible correlation between the expression of these molecular factors and the prognosis of gallbladder carcinoma. They resulted highly expressed in the stroma (CD34 and CA 15-3) and in the epithelium/epithelial glands (MIB-1) of the neoplastic areas and appeared to be almost absent in the control cases, suggesting that these markers, taken together

  3. Human gallbladder carcinoma: Role of neurotrophins, MIB-1, CD34 and CA15-3

    PubMed Central

    Artico, M.; Bronzetti, E.; Alicino, V.; Ionta, B.; Bosco, S.; Grande, C.; Bruno, M.; Tranquilli Leali, F. M.; Ionta, G.; Fumagalli, L.

    2010-01-01

    Gallbladder carcinoma is the most common biliary tract tumor and the fifth most common gastrointestinal tract cancer. The prognosis of gallbladder carcinoma is poor and less than 5% of the patients are still alive five years postoperatively. Gallbladder specimens were obtained during surgical operations performed in eleven patients for resection of a gallbladder carcinoma, and during five autopsies (control cases selected among patients who died from for other causes, excluding those suffering from biliary or hepatic diseases). Immunohistochemical characterization and distribution of neurotrophins, with their respective receptors, were analyzed. The actual role played by these neurotrophic factors in the general regulation, vascular permeability, algic responsiveness, release of locally active substances and potential tumorigenesis in the gallbladder and biliary ducts compartment remains controversial. Our study revealed an increased immunohistochemical expression of NGF and TrKA in the epithelium and in the epithelial glands of the gallbladder carcinoma together with an evident immunoreactivity for BDNF in the same neoplastic areas. An evident immunoreactivity for NGF, TrKA and BDNF was observed in control specimens of gallbladder obtained during autopsies, whereas a weak or quite absent immunoreactivity was observed in the same specimens for NT4, TrKC and p75. On the contrary an appreciable immunoreactivity for p75 was observed in the specimens harvested from patients with gallbladder carcinoma. We also investigated the expression of some known tumor markers such as MIB-1 (anti Ki-67), CD34 and CA15-3, to identify a possible correlation between the expression of these molecular factors and the prognosis of gallbladder carcinoma. They resulted highly expressed in the stroma (CD34 and CA 15-3) and in the epithelium/epithelial glands (MIB-1) of the neoplastic areas and appeared to be almost absent in the control cases, suggesting that these markers, taken together

  4. Mammalian neurotrophin-4: structure, chromosomal localization, tissue distribution, and receptor specificity.

    PubMed Central

    Ip, N Y; Ibáñez, C F; Nye, S H; McClain, J; Jones, P F; Gies, D R; Belluscio, L; Le Beau, M M; Espinosa, R; Squinto, S P

    1992-01-01

    Nerve growth factor, brain-derived neurotrophic factor, and neurotrophin-3 (NT-3) are the three members of the neurotrophin family known to exist in mammals. Recently, a fourth neurotrophin (designated neurotrophin-4 or NT-4), which shares all of the features found in the mammalian neurotrophins, has been identified in Xenopus and viper. We used sequences specific to the Xenopus/viper NT-4 to isolate a neurotrophin from both human and rat genomic DNA that appears to represent the mammalian counterpart of Xenopus/viper NT-4. Human NT-4 as well as a human NT-4 pseudogene colocalize to chromosome 19 band q13.3. Mammalian NT-4 has many unusual features compared to the previously identified neurotrophins and is less conserved evolutionarily than the other neurotrophins. However, mammalian NT-4 displays bioactivity and trk receptor specificity similar to that of Xenopus NT-4. Images PMID:1313578

  5. Chronic Stress Induces Neurotrophin-3 in Rat Submandibular Gland

    PubMed Central

    Saruta, Juri; Iida, Michitaro; Kondo, Yusuke; To, Masahiro; Hayashi, Takashi; Hori, Mayumi; Sato, Sadao

    2012-01-01

    Purpose Plasma neurotrophin-3 (NT-3) levels are associated with several neural disorders. We previously reported that neurotrophins were released from salivary glands following acute immobilization stress. While the salivary glands were the source of plasma neurotrophins in that situation, the association between the expression of neurotrophins and the salivary gland under chronic stress conditions is not well understood. In the present study, we investigated whether NT-3 levels in the salivary gland and plasma were influenced by chronic stress. Materials and Methods Expressions of NT-3 mRNA and protein were characterized, using real-time polymerase chain reactions, enzyme-linked immunosorbent assay, and immunohistochemistry, in the submandibular glands of male rats exposed to chronic stress (12 h daily for 22 days). Results Plasma NT-3 levels were significantly increased by chronic stress (p<0.05), and remained elevated in bilaterally sialoadenectomized rats under the same condition. Since chronic stress increases plasma NT-3 levels in the sialoadenectomized rat model, plasma NT-3 levels were not exclusively dependent on salivary glands. Conclusion While the salivary gland was identified in our previous study as the source of plasma neurotrophins during acute stress, the exposure to long-term stress likely affects a variety of organs capable of releasing NT-3 into the bloodstream. In addition, the elevation of plasma NT-3 levels may play important roles in homeostasis under stress conditions. PMID:23074106

  6. Nanoparticles carrying neurotrophin-3-modified Schwann cells promote repair of sciatic nerve defects

    PubMed Central

    Zong, Haibin; Zhao, Hongxing; Zhao, Yilei; Jia, Jingling; Yang, Libin; Ma, Chao; Zhang, Yang; Dong, Yuzhen

    2013-01-01

    Schwann cells and neurotrophin-3 play an important role in neural regeneration, but the secretion of neurotrophin-3 from Schwann cells is limited, and exogenous neurotrophin-3 is inactived easily in vivo. In this study, we have transfected neurotrophin-3 into Schwann cells cultured in vitro using nanoparticle liposomes. Results showed that neurotrophin-3 was successfully transfected into Schwann cells, where it was expressed effectively and steadily. A composite of Schwann cells transfected with neurotrophin-3 and poly(lactic-co-glycolic acid) biodegradable conduits was transplanted into rats to repair 10-mm sciatic nerve defects. Transplantation of the composite scaffold could restore the myoelectricity and wave amplitude of the sciatic nerve by electrophysiological examination, promote nerve axonal and myelin regeneration, and delay apoptosis of spinal motor neurons. Experimental findings indicate that neurotrophin-3 transfected Schwann cells combined with bridge grafting can promote neural regeneration and functional recovery after nerve injury. PMID:25206420

  7. Exemestane With or Without Entinostat in Treating Patients With Recurrent Hormone Receptor-Positive Breast Cancer That is Locally Advanced or Metastatic

    ClinicalTrials.gov

    2016-09-15

    Estrogen Receptor Positive; HER2/Neu Negative; Male Breast Carcinoma; Progesterone Receptor Positive; Recurrent Breast Carcinoma; Stage IIIB Breast Cancer; Stage IIIC Breast Cancer; Stage IV Breast Cancer

  8. Regulation of Neurotrophin-Induced Axonal Responses via Rho GTPases

    PubMed Central

    HANDEÖZDINLER, P.; ERZURUMLU, REHA S.

    2014-01-01

    Nerve growth factor (NGF) and related neurotrophins induce differential axon growth patterns from embryonic sensory neurons. In wholemount explant cultures of embryonic rat trigeminal ganglion and brainstem or in dissociated cell cultures of the trigeminal ganglion, exogenous supply of NGF leads to axonal elongation, whereas neurotrophin-3 (NT-3) treatment leads to short branching and arborization. Axonal responses to neurotrophins might be mediated via the Rho GTPases. To investigate this possibility, we prepared wholemount trigeminal pathway cultures from E15 rats. We infected the ganglia with recombinant vaccinia viruses that express GFP-tagged dominant negative Rac, Rho, or constitutively active Rac or treated the cultures with lysophosphatitic acid (LPA) to activate Rho. We then examined axonal responses to NGF by use of the lipophilic tracer DiI. Rac activity induced longer axonal growth from the central trigeminal tract, whereas the dominant negative construct of Rac eliminated NGF-induced axon outgrowth. Rho activity also significantly reduced, and the Rho dominant negative construct increased, axon growth from the trigeminal tract. Similar alterations in axonal responses to NT-3 and brain-derived neurotrophic factor were also noted. Our results demonstrate that Rho GTPases play a major role in neurotrophin-induced axonal differentiation of embryonic trigeminal axons. PMID:11559894

  9. METHYLMERCURY IMPAIRS NEURONAL DIFFERENTIATION BY ALTERING NEUROTROPHIN SIGNALING.

    EPA Science Inventory

    In previous in vivo studies, we observed that developmental exposure to CH3Hg can alter neocortical morphology and neurotrophin signaling. Using primed PC12 cells as a model system for neuronal differentiation, we examined the hypothesis that the developmental effects of CH3Hg ma...

  10. INCREASED PRODUCTION OF NERVE GROWTH FACTOR, NEUROTROPHIN-3, AND NEUROTROPHIN-4 IN A PENICILLIUM CHRYSOGENUM -INDUCED ALLERGIC ASTHMA MODEL IN MICE

    EPA Science Inventory

    Increased levels of neurotrophins (nerve growth factor [NGF], brain-derived neurotrophic factor [BDNF], neurotrophin [NT]-3, and/or NT-4) have been associated with asthmatics and in animal models of allergic asthma. In our mouse model for fungal allergic asthma, repeated pulmona...

  11. DOSE-DEPENDENT INCREASE IN THE PRODUCTION OF NERVE GROWTH FACTOR, NEUROTROPHIN-3, AND NEUROTROPHIN-4 IN A PENICILLIUM CHRYSOGENUM-INDUCED ALLERGIC ASTHMA MODEL

    EPA Science Inventory


    Increased levels of neurotrophins (nerve growth factor [NGF], brain-derived neurotrophic factor [BDNF], neurotrophin [NT]-3, and/or NT-4) have been associated with asthma as well as in animal models of allergic asthma. In our mouse model for fungal allergic asthma, repeated ...

  12. Local Effect of Neurotrophin-3 in Neuronal Inflammation of Allergic Rhinitis: Preliminary Report

    PubMed Central

    İsmi, Onur; Özcan, Cengiz; Karabacak, Tuba; Polat, Gürbüz; Vayisoğlu, Yusuf; Güçlütürk, Taylan; Görür, Kemal

    2015-01-01

    Background: Allergic rhinitis is a common inflammatory nasal mucosal disease characterized by sneezing, watery nasal discharge, nasal obstruction and itching. Although allergen-specific antibodies play a main role in the allergic airway inflammation, neuronal inflammation may also contribute to the symptoms of allergic rhinitis. Neuronal inflammation is primarily caused by the stimulation of sensory nerve endings with histamine. It has been shown that neurotrophins may also have a role in allergic reactions and neuronal inflammation. Nerve growth factor, neurotrophin 3 (NT-3), neurotrophin 4/5 and brain-derived neurotrophic factor are members of the neurotrophin family. Although nerve growth factor and brain-derived neurotrophic factor are well studied in allergic rhinitis patients, the exact role of Neurotrophin-3 is not known. Aims: To investigate the possible roles of neurotrophin-3 in allergic rhinitis patients. Study Design: Case-control study. Methods: Neurotrophin-3 levels were studied in the inferior turbinate and serum samples of 20 allergic rhinitis and 13 control patients. Neurotrophin-3 staining of nasal tissues was evaluated by immunohistochemistry and ELISA was used for the determination of serum Neurotrophin-3 levels. Results: Neurotrophin-3 staining scores were statistically higher in the study group than in the control patients (p=0.001). Regarding serum Neurotrophin-3 levels, no statistically significant difference could be determined between allergic rhinitis and control patients (p=0.156). When comparing the serum NT-3 levels with tissue staining scores, there were no statistically significant differences in the allergic rhinitis and control groups (p=0.254 for allergic rhinitis and p=0.624 for control groups). Conclusion: We suggest that Neurotrophin-3 might affect the nasal mucosa locally without being released into the systemic circulation in allergic rhinitis patients. PMID:26740895

  13. Kissing reduces allergic skin wheal responses and plasma neurotrophin levels.

    PubMed

    Kimata, Hajime

    2003-11-01

    The effect of kissing on allergen-induced skin wheal responses and plasma neurotrophin levels were studied in 30 normal subjects, 30 patients with allergic rhinitis (AR), and 30 patients with atopic dermatitis (AD). All of the patients with AR or AD are allergic to house dust mite (HDM) and Japanese cedar pollen (JCP). They are all Japanese and they do not kiss habitually. The subject kissed freely during 30 min with their lover or spouse alone in a room with closed doors while listening to soft music. Before and after kissing, skin prick tests were performed using commercial HDM allergen, JCP allergen, as well as histamine and control solution, and wheal responses were measured. Simultaneously, plasma levels of neurotrophin, including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and -4 (NT-4) were measured. Kissing significantly reduced wheal responses induced by HDM and JCP, but not by histamine, and decreased plasma levels of NGF, BDNF, NT-3, and NT-4 in patients with AR or AD, while it failed to do so in normal subjects. These finding indicate that kissing have some implication in the study of neuroimmunology in allergic patients. PMID:14637240

  14. The Neurotrophins and Their Role in Alzheimer’s Disease

    PubMed Central

    Allen, Shelley J; Watson, Judy J; Dawbarn, David

    2011-01-01

    Besides being essential for correct development of the vertebrate nervous system the neurotrophins also play a vital role in adult neuron survival, maintenance and regeneration. In addition they are implicated in the pathogenesis of certain neurodegenerative diseases, and may even provide a therapeutic solution for some. In particular there have been a number of studies on the involvement of nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF) in the development of Alzheimer’s disease. This disease is of growing concern as longevity increases worldwide, with little treatment available at the moment to alleviate the condition. Memory loss is one of the earliest symptoms associated with Alzheimer’s disease. The brain regions first affected by pathology include the hippocampus, and also the entorhinal cortex and basal cholinergic nuclei which project to the hippocampus; importantly, all these areas are required for memory formation. Both NGF and BDNF are affected early in the disease and this is thought to initiate a cascade of events which exacerbates pathology and leads to the symptoms of dementia. This review briefly describes the pathology, symptoms and molecular processes associated with Alzheimer’s disease; it discusses the involvement of the neurotrophins, particularly NGF and BDNF, and their receptors, with changes in BDNF considered particularly in the light of its importance in synaptic plasticity. In addition, the possibilities of neurotrophin-based therapeutics are evaluated. PMID:22654716

  15. Differential regulation of axon outgrowth and reinnervation by neurotrophin-3 and neurotrophin-4 in the hippocampal formation.

    PubMed

    Hechler, Daniel; Boato, Francesco; Nitsch, Robert; Hendrix, Sven

    2010-08-01

    In this study, we investigated the hypothesis whether neurotrophins have a differential influence on neurite growth from the entorhinal cortex depending on the presence or absence of hippocampal target tissue. We investigated organotypic brain slices derived from the entorhinal-hippocampal system to analyze the effects of endogenous and recombinant neurotrophin-3 (NT-3) and neurotrophin-4 (NT-4) on neurite outgrowth and reinnervation. In the reinnervation assay, entorhinal cortex explants of transgenic mice expressing enhanced green fluorescent protein (EGFP) were co-cultured with wild-type hippocampi under the influence of recombinant NT-3 and NT-4 (500 ng/ml). Both recombinant NT-3 and NT-4 significantly increased the growth of EGFP+ nerve fibers into the target tissue. Consistently, reinnervation of the hippocampi of NT-4(-/-) and NT-3(+/-)NT-4(-/-) mice was substantially reduced. In contrast, the outgrowth assay did not exhibit reduction in axon outgrowth of NT-4(-/-) or NT-3(+/-)NT-4(-/-) cortex explants, while the application of recombinant NT-3 (500 ng/ml) induced a significant increase in the neurite extension of cortex explants. Recombinant NT-4 had no effect. In summary, only recombinant NT-3 stimulates axon outgrowth from cortex explants, while both endogenous and recombinant NT-3 and NT-4 synergistically promote reinnervation of the denervated hippocampus. These results suggest that endogenous and exogenous NT-3 and NT-4 differentially influence neurite growth depending on the presence or absence of target tissue. PMID:20640412

  16. PTEN downregulates p75NTR expression by decreasing DNA-binding activity of Sp1

    SciTech Connect

    Rankin, Sherri L.; Guy, Clifford S.; Mearow, Karen M.

    2009-02-13

    p75NTR is expressed throughout the nervous system and its dysregulation is associated with pathological conditions. We have recently demonstrated a signalling cascade initiated by laminin (LN), which upregulates PTEN and downregulates p75NTR. Here we investigate the mechanism by which PTEN modulates p75NTR. Studies using PTEN mutants show that its protein phosphatase activity directly modulates p75NTR protein expression. Nuclear relocalization of PTEN subsequent to LN stimulation suggests transcriptional control of p75NTR expression, which was confirmed following EMSA and ChIP analysis of Sp1 transcription factor binding activity. LN and PTEN independently decrease the DNA-binding ability of PTEN to the p75NTR promoter. Sp1 regulation of p75NTR occurs via dephosphorylation of Sp1, thus reducing p75NTR transcription and protein expression. This mechanism represents a novel regulatory pathway which controls the expression level of a receptor with broad implications not only for the development of the nervous system but also for progression of pathological conditions.

  17. Helix-loop-helix transcription factors mediate activation and repression of the p75LNGFR gene.

    PubMed Central

    Chiaramello, A; Neuman, K; Palm, K; Metsis, M; Neuman, T

    1995-01-01

    Sequence analysis of rat and human low-affinity nerve growth factor receptor p75LNGFR gene promoter regions revealed a single E-box cis-acting element, located upstream of the major transcription start sites. Deletion analysis of the E-box sequence demonstrated that it significantly contributes to p75LNGFR promoter activity. This E box has a dual function; it mediates either activation or repression of the p75LNGFR promoter activity, depending on the interacting transcription factors. We showed that the two isoforms of the class A basic helix-loop-helix (bHLH) transcription factor ME1 (ME1a and ME1b), the murine homolog of the human HEB transcription factor, specifically repress p75LNGFR promoter activity. This repression can be released by coexpression of the HLH Id2 transcriptional regulator. In vitro analyses demonstrated that ME1a forms a stable complex with the p75LNGFR E box and likely competes with activating E-box-binding proteins. By using ME1a-overexpressing PC12 cells, we showed that the endogenous p75LNGFR gene is a target of ME1a repression. Together, these data demonstrate that the p75LNGFR E box and the interacting bHLH transcription factors are involved in the regulation of p75LNGFR gene expression. These results also show that class A bHLH transcription factors can repress and Id-like negative regulators can stimulate gene expression. PMID:7565756

  18. BMP7-induced dendritic growth in sympathetic neurons requires p75(NTR) signaling.

    PubMed

    Courter, Lauren A; Shaffo, Frances C; Ghogha, Atefeh; Parrish, Diana J; Lorentz, Christina U; Habecker, Beth A; Lein, Pamela J

    2016-09-01

    Dendritic morphology is a critical determinant of neuronal connectivity, and in postganglionic sympathetic neurons, tonic activity correlates directly with the size of the dendritic arbor. Thus, identifying signaling mechanisms that regulate dendritic arborization of sympathetic neurons is important to understanding how functional neural circuitry is established and maintained in the sympathetic nervous system. Bone morphogenetic proteins (BMPs) promote dendritic growth in sympathetic neurons; however, downstream signaling events that link BMP receptor activation to dendritic growth are poorly characterized. We previously reported that BMP7 upregulates p75(NTR) mRNA in cultured sympathetic neurons. This receptor is implicated in controlling dendritic growth in central neurons but whether p75(NTR) regulates dendritic growth in peripheral neurons is not known. Here, we demonstrate that BMP7 increases p75(NTR) protein in cultured sympathetic neurons, and this effect is blocked by pharmacologic inhibition of signaling via BMP type I receptor. BMP7 does not trigger dendritic growth in sympathetic neurons dissociated from superior cervical ganglia (SCG) of p75(NTR) nullizygous mice, and overexpression of p75(NTR) in p75(NTR) -/- neurons is sufficient to cause dendritic growth even in the absence of BMP7. Morphometric analyses of SCG from wild-type versus p75(NTR) nullizygous mice at 3, 6, and 12 to 16 weeks of age indicated that genetic deletion of p75(NTR) does not prevent dendritic growth but does stunt dendritic maturation in sympathetic neurons. These data support the hypotheses that p75(NTR) is involved in downstream signaling events that mediate BMP7-induced dendritic growth in sympathetic neurons, and suggest that p75(NTR) signaling positively modulates dendritic complexity in sympathetic neurons in vivo. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 76: 1003-1013, 2016. PMID:26663679

  19. Cytokine Spatzle binds to the Drosophila immunoreceptor Toll with a neurotrophin-like specificity and couples receptor activation.

    PubMed

    Lewis, Miranda; Arnot, Christopher J; Beeston, Helen; McCoy, Airlie; Ashcroft, Alison E; Gay, Nicholas J; Gangloff, Monique

    2013-12-17

    Drosophila Toll functions in embryonic development and innate immunity and is activated by an endogenous ligand, Spätzle (Spz). The related Toll-like receptors in vertebrates also function in immunity but are activated directly by pathogen-associated molecules such as bacterial endotoxin. Here, we present the crystal structure at 2.35-Å resolution of dimeric Spz bound to a Toll ectodomain encompassing the first 13 leucine-rich repeats. The cystine knot of Spz binds the concave face of the Toll leucine-rich repeat solenoid in an area delineated by N-linked glycans and induces a conformational change. Mutagenesis studies confirm that the interface observed in the crystal structure is relevant for signaling. The asymmetric binding mode of Spz to Toll is similar to that of nerve growth factor (NGF) in complex with the p75 neurotrophin receptor but is distinct from that of microbial ligands bound to the Toll-like receptors. Overall, this study indicates an allosteric signaling mechanism for Toll in which ligand binding to the N terminus induces a conformational change that couples to homodimerization of juxtamembrane structures in the Toll ectodomain C terminus. PMID:24282309

  20. Differential expression of neurotrophins in postnatal C57BL/6 mice striatum

    PubMed Central

    Zermeño, V.; Espindola, S.; Mendoza, E.; Hernández-Echeagaray, E.

    2009-01-01

    Neurotrophin expression in early stages of development is crucial for brain assembly and function. In particular, postnatal expression of neurotrophins has not been well documented in the neostriatum and in general neurotrophins or their receptor mRNA's are normally reported, but not protein expression. In the present study, immunocytochemical expression of BDNF, NT-3 and NT-4/5 was characterized in striatal tissue of C57BL/6 mice at postnatal days 10th (P10), 21st (P21), 42nd (P42) and 80th (P80). We found that the expression of BDNF diminished along the postnatal time course we evaluated, while staining for NT-4 increased up to age P42 and remained constant, thereafter in the cell's soma. In contrast, NT-3 was first expressed in the neostriatal bundles and later on, in neostriatal cell somas. These results provide information about differences in the spatial and temporal expression of each neurotrophin in the neostriatum during the first 80th postnatal days. RT-PCR procedures were also carried out to further determine whether protein levels of neurotrophins observed in the neostriatum were under control of gene expression. All neurotrophin mRNAs were expressed and only mRNABDNF was reduced during the postnatal evaluated days. Differences in temporal expression of neurotrophins may be related to the heterochronic development of neostriatal cell populations, but also with the specificity of each neurotrophin modulating different neuronal targets. PMID:19173033

  1. Multiple cellular proteins interact with LEDGF/p75 through a conserved unstructured consensus motif.

    PubMed

    Tesina, Petr; Čermáková, Kateřina; Hořejší, Magdalena; Procházková, Kateřina; Fábry, Milan; Sharma, Subhalakshmi; Christ, Frauke; Demeulemeester, Jonas; Debyser, Zeger; De Rijck, Jan; Veverka, Václav; Řezáčová, Pavlína

    2015-01-01

    Lens epithelium-derived growth factor (LEDGF/p75) is an epigenetic reader and attractive therapeutic target involved in HIV integration and the development of mixed lineage leukaemia (MLL1) fusion-driven leukaemia. Besides HIV integrase and the MLL1-menin complex, LEDGF/p75 interacts with various cellular proteins via its integrase binding domain (IBD). Here we present structural characterization of IBD interactions with transcriptional repressor JPO2 and domesticated transposase PogZ, and show that the PogZ interaction is nearly identical to the interaction of LEDGF/p75 with MLL1. The interaction with the IBD is maintained by an intrinsically disordered IBD-binding motif (IBM) common to all known cellular partners of LEDGF/p75. In addition, based on IBM conservation, we identify and validate IWS1 as a novel LEDGF/p75 interaction partner. Our results also reveal how HIV integrase efficiently displaces cellular binding partners from LEDGF/p75. Finally, the similar binding modes of LEDGF/p75 interaction partners represent a new challenge for the development of selective interaction inhibitors. PMID:26245978

  2. Regulation of Neurogenesis by Neurotrophins during Adulthood: Expected and Unexpected Roles

    PubMed Central

    Vilar, Marçal; Mira, Helena

    2016-01-01

    The subventricular zone (SVZ) of the anterolateral ventricle and the subgranular zone (SGZ) of the hippocampal dentate gyrus are the two main regions of the adult mammalian brain in which neurogenesis is maintained throughout life. Because alterations in adult neurogenesis appear to be a common hallmark of different neurodegenerative diseases, understanding the molecular mechanisms controlling adult neurogenesis is a focus of active research. Neurotrophic factors are a family of molecules that play critical roles in the survival and differentiation of neurons during development and in the control of neural plasticity in the adult. Several neurotrophins and neurotrophin receptors have been implicated in the regulation of adult neurogenesis at different levels. Here, we review the current understanding of neurotrophin modulation of adult neurogenesis in both the SVZ and SGZ. We compile data supporting a variety of roles for neurotrophins/neurotrophin receptors in different scenarios, including both expected and unexpected functions. PMID:26903794

  3. Regulation of Neurogenesis by Neurotrophins during Adulthood: Expected and Unexpected Roles.

    PubMed

    Vilar, Marçal; Mira, Helena

    2016-01-01

    The subventricular zone (SVZ) of the anterolateral ventricle and the subgranular zone (SGZ) of the hippocampal dentate gyrus are the two main regions of the adult mammalian brain in which neurogenesis is maintained throughout life. Because alterations in adult neurogenesis appear to be a common hallmark of different neurodegenerative diseases, understanding the molecular mechanisms controlling adult neurogenesis is a focus of active research. Neurotrophic factors are a family of molecules that play critical roles in the survival and differentiation of neurons during development and in the control of neural plasticity in the adult. Several neurotrophins and neurotrophin receptors have been implicated in the regulation of adult neurogenesis at different levels. Here, we review the current understanding of neurotrophin modulation of adult neurogenesis in both the SVZ and SGZ. We compile data supporting a variety of roles for neurotrophins/neurotrophin receptors in different scenarios, including both expected and unexpected functions. PMID:26903794

  4. Fulvestrant With or Without Lapatinib in Treating Postmenopausal Women With Stage III or Stage IV Breast Cancer That is Hormone Receptor-Positive

    ClinicalTrials.gov

    2016-07-25

    Estrogen Receptor Positive; HER2 Positive Breast Carcinoma; HER2/Neu Negative; Progesterone Receptor Positive; Recurrent Breast Carcinoma; Stage IIIB Breast Cancer; Stage IIIC Breast Cancer; Stage IV Breast Cancer

  5. Docetaxel, Carboplatin, Trastuzumab, and Pertuzumab With or Without Estrogen Deprivation in Treating Patients With Hormone Receptor-Positive, HER2-Positive Operable or Locally Advanced Breast Cancer

    ClinicalTrials.gov

    2016-09-15

    Estrogen Receptor Positive; HER2/Neu Positive; Progesterone Receptor Positive; Stage IB Breast Cancer; Stage IIA Breast Cancer; Stage IIB Breast Cancer; Stage IIIA Breast Cancer; Stage IIIB Breast Cancer; Stage IIIC Breast Cancer

  6. Effects of cure temperature, electron radiation, and thermal cycling on P75/930 composites

    NASA Technical Reports Server (NTRS)

    Funk, Joan G.

    1990-01-01

    Graphite/epoxy composites are candidates for future space structures due to high stiffness and dimensional stability requirements of these structures. Typical graphite/epoxy composites are brittle and have high residual stresses which often result in microcracking during the thermal cycling typical of the space environment. Composite materials used in geosynchronous orbit applications will also be exposed to high levels of radiation. The purpose of the present study was to determine the effects of cure temperature and radiation exposure on the shear strength and thermal cycling-induced microcrack density of a high modulus, 275 F cure epoxy, P75/930. The results from the P75/930 are compared to previously reported data on P75/934 and T300/934 where 934 is a standard 350 F cure epoxy. The results of this study reveal that P75/930 is significantly degraded by total doses of electron radiation greater than 10(exp 8) rads and by thermally cycling between -250 F and 150 F. The P75/930 did not have improved microcrack resistance over the P75/934, and the 930 resin system appears to be more sensitive to electron radiation-induced degradation than the 934 resin system.

  7. p75NTR, but not proNGF, is upregulated following status epilepticus in mice.

    PubMed

    VonDran, Melissa W; LaFrancois, John; Padow, Victoria A; Friedman, Wilma J; Scharfman, Helen E; Milner, Teresa A; Hempstead, Barbara L

    2014-01-01

    ProNGF and p75(NTR) are upregulated and induce cell death following status epilepticus (SE) in rats. However, less is known about the proneurotrophin response to SE in mice, a more genetically tractable species where mechanisms can be more readily dissected. We evaluated the temporal- and cell-specific induction of the proneurotrophins and their receptors, including p75(NTR), sortilin, and sorCS2, following mild SE induced with kainic acid (KA) or severe SE induced by pilocarpine. We found that mature NGF, p75(NTR), and proBDNF were upregulated following SE, while proNGF was not altered, indicating potential mechanistic differences between rats and mice. ProBDNF was localized to mossy fibers and microglia following SE. p75(NTR) was transiently induced primarily in axons and axon terminals following SE, as well as in neuron and astrocyte cell bodies. ProBDNF and p75(NTR) increased independently of cell death and their localization was different depending on the severity of SE. We also examined the expression of proneurotrophin co-receptors, sortilin and sorCS2. Following severe SE, sorCS2, but not sortilin, was elevated in neurons and astrocytes. These data indicate that important differences exist between rat and mouse in the proneurotrophin response following SE. Moreover, the proBDNF and p75(NTR) increase after seizures in the absence of significant cell death suggests that proneurotrophin signaling may play other roles following SE. PMID:25290065

  8. State of the art of the neurotrophin hypothesis in psychiatric disorders: implications and limitations.

    PubMed

    Lang, U E; Jockers-Scherübl, M C; Hellweg, R

    2004-03-01

    The neurotrophin hypothesis proposes that repetitive neuronal activity enhances the expression, secretion and actions of neurotrophins to modify synaptic transmission and connectivity thereby providing a connection between neuronal activity and synaptic plasticity. Moreover, there is ample evidence that neurotrophins have numerous neuroprotective effects under pathological conditions, which might be important in particular for neurodegenerative diseases such as Alzheimer' disease. Current research postulates that effects during brain development lead to defective neural connectivity and altered biochemical functioning resulting in cognitive, emotional and intentional dysfunction later in life. This implicates a possible role in most psychiatric diseases including affective and schizophrenic disorders. This hypothesis is mainly based on new experimental evidence showing that psychiatric disorders are associated with neuronal atrophy and cell loss, impairments of structural plasticity and cellular resilience due to neurodevelopmental disturbances and morphological abnormalities of the brain. Thus, the potential role of neurotrophins in psychiatric disorders has been studied in different ways. Animal studies indicate the involvement of neurotrophins in psychopharmacological therapies and they show that gene expression of cerebral neurotrophins is changed in animal models of several psychiatric disorders. Whether such alterations are causatively associated with increased neural plasticity, improved cognitive function and decreased depressive mood states remains to be elucidated in further studies including man (e.g. in postmortem studies of patients). Association studies tried to link different variants in genes coding for neurotrophins, they have not been conclusive however. They partially allow to separate different subgroups of patients with differing therapy response profiles or indicate an increased vulnerability for a specific disorder. Finally, neurotrophin

  9. Clinical significance of SPRR1A expression in progesterone receptor-positive breast cancer.

    PubMed

    Chen, Guanglei; Li, Gang; Luo, Minna; Wei, Xiaofei; Wang, Dan; Zhang, Hao; Zhao, Xinhan; Chen, Bo; Liu, Caigang

    2015-04-01

    Small proline-rich repeat protein 1A (SPRR1A) is a marker for terminal squamous cell differentiation. Previous studies showed that SPRR1A expression increases in squamous cell carcinoma of the skin, but decreases in esophageal squamous cell carcinoma. This study focuses on the expression of SPRR1A protein in breast cancers (BCs) in China. A total of 111 patients with histologically confirmed BC, who underwent radical surgery between January 2006 and September 2007 in China Medical University, were enrolled. The relationship between SPRR1A expression and clinicopathological factors as well as BC prognoses was also determined. Overall, SPRR1A expression was detected in more than half of the BC specimens by immunohistochemistry (56/111, 53.8%), but there was no significant difference between age groups (≥50 vs. <50 years) in terms of SPRR1A expression (P = 0.915), as well as no differences between SPRR1A expression and the clinical stage (0-I vs. II-III) or nodal status (P = 0.234 and 0.632, respectively). Moreover, human epidermal growth factor receptor 2 overexpression was not correlated with SPRR1A expression, whereas Ki67 was associated with SPRR1A expression (P = 0.155 and 0.028, respectively). Interestingly, SPRR1A expression was significantly associated with progesterone receptor-positive (P = 0.010) rather than estrogen receptor-positive (0.778) BCs. The 5-year survival rate in patients did not differ with the presence or absence of SPRR1A expression (P = 0.753), whereas the combination of SPRR1A expression, progesterone receptor status, and menopausal status allowed identification of a subgroup of BC patients with a good long-term prognosis. Thus, the SPRR1A status might play an important role in the prognosis of postmenopausal breast carcinoma patients, especially that of progesterone receptor-positive subgroups. PMID:25424702

  10. Current status of hormone therapy in patients with hormone receptor positive (HR+) advanced breast cancer.

    PubMed

    Dalmau, Elsa; Armengol-Alonso, Alejandra; Muñoz, Montserrat; Seguí-Palmer, Miguel Ángel

    2014-12-01

    The natural history of HR+ breast cancer tends to be different from hormone receptor-negative disease in terms of time to recurrence, site of recurrence and overall aggressiveness of the disease. The developmental strategies of hormone therapy for the treatment of breast cancer have led to the classes of selective estrogen receptor modulators, selective estrogen receptor downregulators, and aromatase inhibitors. These therapeutic options have improved breast cancer outcomes in the metastatic setting, thereby delaying the need for chemotherapy. However, a subset of hormone receptor-positive breast cancers do not benefit from endocrine therapy (intrinsic resistance), and all HR+ metastatic breast cancers ultimately develop resistance to hormonal therapies (acquired resistance). Considering the multiple pathways involved in the HR network, targeting other components of pathologically activated intracellular signaling in breast cancer may prove to be a new direction in clinical research. This review focuses on current and emerging treatments for HR+ metastatic breast cancer. PMID:25311296

  11. Modern reproductive patterns associated with estrogen receptor positive but not negative breast cancer susceptibility

    PubMed Central

    Aktipis, C. Athena; Ellis, Bruce J.; Nishimura, Katherine K.; Hiatt, Robert A.

    2015-01-01

    It has long been accepted that modern reproductive patterns are likely contributors to breast cancer susceptibility because of their influence on hormones such as estrogen and the importance of these hormones in breast cancer. We conducted a meta-analysis to assess whether this ‘evolutionary mismatch hypothesis’ can explain susceptibility to both estrogen receptor positive (ER-positive) and estrogen receptor negative (ER-negative) cancer. Our meta-analysis includes a total of 33 studies and examines parity, age of first birth and age of menarche broken down by estrogen receptor status. We found that modern reproductive patterns are more closely linked to ER-positive than ER-negative breast cancer. Thus, the evolutionary mismatch hypothesis for breast cancer can account for ER-positive breast cancer susceptibility but not ER-negative breast cancer. PMID:25389105

  12. GABAB Receptor-Positive Modulators: Enhancement of GABAB Receptor Agonist Effects In Vivo

    PubMed Central

    France, Charles P.; Cheng, Kejun; Rice, Kenner C.

    2010-01-01

    In vivo effects of GABAB receptor-positive modulators suggest that they have therapeutic potential for treating central nervous system disorders such as anxiety, depression, and drug abuse. Although these effects generally are thought to be mediated by positive modulation of GABAB receptors, such modulation has been examined primarily in vitro. The present study was aimed at further examining the in vivo positive modulatory properties of the GABAB receptor-positive modulators, 2,6-di-tert-butyl-4-(3-hydroxy-2,2-dimethylpropyl) phenol (CGP7930) and (R,S)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3H-benzofuran-2-one (rac-BHFF). Both compounds enhanced loss of righting induced by baclofen in mice. However, CGP7930 was less effective and rac-BHFF was less potent for enhancing loss of righting induced by γ-hydroxybutyrate (GHB), which, like baclofen, has GABAB receptor agonist properties. In contrast with baclofen- and GHB-induced loss of righting, the hypothermic effects of baclofen and GHB were not enhanced by rac-BHFF but were enhanced by CGP7930 only at doses that produced hypothermia when given alone. CGP7930-induced hypothermia was not attenuated by the GABAB receptor antagonist 3-aminopropyl(diethoxymethyl)phosphinic acid (CGP35348), at doses that blocked baclofen-induced hypothermia, and was not increased by the nitric-oxide synthase inhibitor Nω-nitro-l-arginine methyl ester, at doses that increased the hypothermic effects of baclofen and GHB. The results provide evidence that CGP7930 and rac-BHFF act in vivo as positive modulators at GABAB receptors mediating loss of righting, but not at GABAB receptors mediating hypothermia. Conceivably, CGP7930, but not rac-BHFF, acts as an allosteric agonist at these latter receptors. Taken together, the results provide further evidence of pharmacologically distinct GABAB receptor subtypes, possibly allowing for a more selective therapeutic interference with the GABAB system. PMID:20628000

  13. Placental Kisspeptins Differentially Modulate Vital Parameters of Estrogen Receptor-Positive and -Negative Breast Cancer Cells.

    PubMed

    Rasoulzadeh, Zahra; Ghods, Roya; Kazemi, Tohid; Mirzadegan, Ebrahim; Ghaffari-Tabrizi-Wizsy, Nassim; Rezania, Simin; Kazemnejad, Somaieh; Arefi, Soheila; Ghasemi, Jamileh; Vafaei, Sedigheh; Mahmoudi, Ahmad-Reza; Zarnani, Amir-Hassan

    2016-01-01

    Kisspeptins (KPs) are major regulators of trophoblast and cancer invasion. Thus far, limited and conflicting data are available on KP-mediated modulation of breast cancer (BC) metastasis; mostly based on synthetic KP-10, the most active fragment of KP. Here, we report for the first time comprehensive functional effects of term placental KPs on proliferation, adhesion, Matrigel invasion, motility, MMP activity and pro-inflammatory cytokine production in MDA-MB-231 (estrogen receptor-negative) and MCF-7 (estrogen receptor-positive). KPs were expressed at high level by term placental syncytiotrophoblasts and released in soluble form. Placental explant conditioned medium containing KPs (CM) significantly reduced proliferation of both cell types compared to CM without (w/o) KP (CM-w/o KP) in a dose- and time-dependent manner. In MDA-MB-231 cells, placental KPs significantly reduced adhesive properties, while increased MMP9 and MMP2 activity and stimulated invasion. Increased invasiveness of MDA-MB-231 cells after CM treatment was inhibited by KP receptor antagonist, P-234. CM significantly reduced motility of MCF-7 cells at all time points (2-30 hr), while it stimulated motility of MDA-MB-231 cells. These effects were reversed by P-234. Co-treatment with selective ER modulators, Tamoxifen and Raloxifene, inhibited the effect of CM on motility of MCF-7 cells. The level of IL-6 in supernatant of MCF-7 cells treated with CM was higher compared to those treated with CM-w/o KP. Both cell types produced more IL-8 after treatment with CM compared to those treated with CM-w/o KP. Taken together, our observations suggest that placental KPs differentially modulate vital parameters of estrogen receptor-positive and -negative BC cells possibly through modulation of pro-inflammatory cytokine production. PMID:27101408

  14. Optimal management of hormone receptor positive metastatic breast cancer in 2016

    PubMed Central

    Reinert, Tomas; Barrios, Carlos H.

    2015-01-01

    Hormone receptor positive tumors represent the most common form of breast cancer and account for most of the deaths from the disease. Endocrine therapy represents the main initial therapeutic strategy for these patients and has been associated with significant clinical benefits in a majority of patients. While in early stages endocrine therapy is administered as part of a curative approach once clinical metastases develop, the disease is considered incurable and the main management objectives are tumor control and quality of life. The two major clinical paradigms of always indicating endocrine therapy in the absence of visceral crises and sequencing endocrine treatments have been guiding our therapeutic approach to these patients. However, for many decades, we have delivered endocrine therapy with a ‘one size fits all’ approach by applying agents that interfere with hormone receptor signaling equally in every clinical patient scenario. We have been unable to incorporate the well-known biologic principle of different degrees of hormone receptor dependency in our therapeutic recommendations. Recent developments in the understanding of molecular interactions of hormone signaling with other important growth factor, metabolic and cell division pathways have opened the possibility of improving results by modulating hormone signaling and interfering with resistance mechanisms yet to be fully understood. Unfortunately, limitations in the design of trials conducted in this area have made it difficult to develop predictive biomarkers and most of the new combinations with targeted agents, even though showing improvements in clinical endpoints, have been directed to an unselected population of patients. In this review we explore some of the current and most relevant literature in the management of hormone receptor positive advance breast cancer. PMID:26557899

  15. Outcomes of Estrogen Receptor Negative and Progesterone Receptor Positive Breast Cancer

    PubMed Central

    Chan, Melissa; Chang, Martin C.; González, Rosa; Lategan, Belinda; del Barco, Elvira; Vera-Badillo, Francisco; Quesada, Paula; Goldstein, Robyn; Cruz, Ignacio; Ocana, Alberto; Cruz, Juan J.; Amir, Eitan

    2015-01-01

    Purpose To describe the clinical features and outcomes of estrogen receptor negative (ER-) and progesterone receptor positive (PgR+) breast cancer. Methods We retrospectively reviewed a well-characterized database of sequential patients diagnosed with early stage invasive breast carcinoma. Outcomes of interest were time to relapse (TTR) and overall survival (OS). Multivariable Cox proportional hazards analysis was conducted to assess the association of ER-/PgR+ with TTR and OS in comparison to ER+ and to ER- and PgR negative (ER-/PgR-) tumors irrespective of HER2 status. ER and PgR expression was conservatively defined as 10% or greater staining of cancer cells. Results 815 patients were followed for a median of 40.5 months; 56 patients (7%) had ER-/PgR+, 624 (77%) had ER+ and 136 (17%) had ER-/PgR- phenotypes. Compared with ER+ tumors, ER-/PgR+ tumors were associated with younger age (50 versus 59 years, p=0.03), high grade (50% versus 24%, p<0.001) and more frequent HER2 overexpression/amplification (43% versus 14%, p<0.001). TTR for ER-/PgR+ was intermediate between ER+ and ER-/PgR- tumors, but was not significantly different from ER+ tumors. Recurrences in the ER-/PgR+ and ER-/PgR- groups occurred early in follow-up while in ER+ tumors recurrences continued to occur over the duration of follow-up. OS of ER-/PgR+ was similar to ER+ tumors and better than that of ER-/PgR- tumors. Conclusions The ER-/PgR+ phenotype is associated with higher grade with HER2 overexpression/amplification and occurs more commonly in younger women. Risk of relapse and death more closely resembles ER+ than ER-/PgR- tumors suggesting this phenotype represents a group of more aggressive hormone receptor positive tumors. PMID:26161666

  16. Placental Kisspeptins Differentially Modulate Vital Parameters of Estrogen Receptor-Positive and -Negative Breast Cancer Cells

    PubMed Central

    Rasoulzadeh, Zahra; Ghods, Roya; Kazemi, Tohid; Mirzadegan, Ebrahim; Ghaffari-Tabrizi-Wizsy, Nassim; Rezania, Simin; Kazemnejad, Somaieh; Arefi, Soheila; Ghasemi, Jamileh; Vafaei, Sedigheh; Mahmoudi, Ahmad-Reza; Zarnani, Amir-Hassan

    2016-01-01

    Kisspeptins (KPs) are major regulators of trophoblast and cancer invasion. Thus far, limited and conflicting data are available on KP-mediated modulation of breast cancer (BC) metastasis; mostly based on synthetic KP-10, the most active fragment of KP. Here, we report for the first time comprehensive functional effects of term placental KPs on proliferation, adhesion, Matrigel invasion, motility, MMP activity and pro-inflammatory cytokine production in MDA-MB-231 (estrogen receptor-negative) and MCF-7 (estrogen receptor-positive). KPs were expressed at high level by term placental syncytiotrophoblasts and released in soluble form. Placental explant conditioned medium containing KPs (CM) significantly reduced proliferation of both cell types compared to CM without (w/o) KP (CM-w/o KP) in a dose- and time-dependent manner. In MDA-MB-231 cells, placental KPs significantly reduced adhesive properties, while increased MMP9 and MMP2 activity and stimulated invasion. Increased invasiveness of MDA-MB-231 cells after CM treatment was inhibited by KP receptor antagonist, P-234. CM significantly reduced motility of MCF-7 cells at all time points (2–30 hr), while it stimulated motility of MDA-MB-231 cells. These effects were reversed by P-234. Co-treatment with selective ER modulators, Tamoxifen and Raloxifene, inhibited the effect of CM on motility of MCF-7 cells. The level of IL-6 in supernatant of MCF-7 cells treated with CM was higher compared to those treated with CM-w/o KP. Both cell types produced more IL-8 after treatment with CM compared to those treated with CM-w/o KP. Taken together, our observations suggest that placental KPs differentially modulate vital parameters of estrogen receptor-positive and -negative BC cells possibly through modulation of pro-inflammatory cytokine production. PMID:27101408

  17. Role of Neurotrophins in the Development and Function of Neural Circuits that Regulate Energy Homeostasis

    PubMed Central

    Fargali, Samira; Sadahiro, Masato; Jiang, Cheng; Frick, Amy L.; Indall, Tricia; Cogliani, Valeria; Welagen, Jelle; Lin, Wei-jye; Salton, Stephen R.

    2012-01-01

    Members of the neurotrophin family, including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4/5 (NT-4/5), and other neurotrophic growth factors such as ciliary neurotrophic factor (CNTF) and artemin, regulate peripheral and central nervous system development and function. A subset of the neurotrophin-dependent pathways in the hypothalamus, brainstem, and spinal cord, and those that project via the sympathetic nervous system to peripheral metabolic tissues including brown and white adipose tissue (BAT and WAT), muscle and liver, regulate feeding, energy storage, and energy expenditure. We briefly review the role that neurotrophic growth factors play in energy balance, as regulators of neuronal survival and differentiation, neurogenesis, and circuit formation and function, and as inducers of critical gene products that control energy homeostasis. PMID:22581449

  18. NEUROTROPHIN MEDIATION OF ALLERGIC AIRWAYS RESPONSES TO INHALED DIESEL PARTICLES IN MICE

    EPA Science Inventory

    Neurotrophins, including nerve growth factor (NGF) partially mediate many features of allergic airways disease including airway hyper-responsiveness. Diesel exhaust particulates (DEP) associated with the combustion of diesel fuel exacerbate many of these allergic airways respons...

  19. Pharmacologic management of bone-related complications and bone metastases in postmenopausal women with hormone receptor-positive breast cancer

    PubMed Central

    Yardley, Denise A

    2016-01-01

    There is a high risk for bone loss and skeletal-related events, including bone metastases, in postmenopausal women with hormone receptor-positive breast cancer. Both the disease itself and its therapeutic treatments can negatively impact bone, resulting in decreases in bone mineral density and increases in bone loss. These negative effects on the bone can significantly impact morbidity and mortality. Effective management and minimization of bone-related complications in postmenopausal women with hormone receptor-positive breast cancer remain essential. This review discusses the current understanding of molecular and biological mechanisms involved in bone turnover and metastases, increased risk for bone-related complications from breast cancer and breast cancer therapy, and current and emerging treatment strategies for managing bone metastases and bone turnover in postmenopausal women with hormone receptor-positive breast cancer. PMID:27217795

  20. The Neurotrophin-Inducible Gene Vgf Regulates Hippocampal Function and Behavior Through a BDNF-Dependent Mechanism

    PubMed Central

    Bozdagi, Ozlem; Rich, Erin; Tronel, Sophie; Sadahiro, Masato; Patterson, Kamara; Shapiro, Matthew L.; Alberini, Cristina M.; Huntley, George W.; Salton, Stephen R. J.

    2009-01-01

    VGF is a neurotrophin-inducible, activity-regulated gene product that is expressed in CNS and PNS neurons, where it is processed into peptides and secreted. VGF synthesis is stimulated by BDNF, a critical regulator of hippocampal development and function, and two VGF C-terminal peptides increase synaptic activity in cultured hippocampal neurons. To assess VGF function in the hippocampus, we tested heterozygous and homozygous VGF knockout mice in two different learning tasks, assessed long-term potentiation (LTP) and depression (LTD) in hippocampal slices from VGF mutant mice, and investigated how VGF C-terminal peptides modulate synaptic plasticity. Treatment of rat hippocampal slices with the VGF-derived peptide TLQP62 resulted in transient potentiation through a mechanism that was selectively blocked by the BDNF scavenger TrkB-Fc, the Trk tyrosine kinase inhibitor K252a (100 nM), and by tPASTOP, an inhibitor of tissue plasminogen activator (tPA), an enzyme involved in pro-BDNF cleavage to BDNF, but was not blocked by the NMDA receptor antagonist APV, anti-p75NTR function-blocking antiserum, nor by prior tetanic stimulation. Although LTP was normal in slices from VGF knockout mice, LTD could not be induced, and VGF mutant mice were impaired in hippocampal-dependent spatial learning and contextual fear conditioning tasks. Our studies indicate that the VGF C-terminal peptide TLQP62 modulates hippocampal synaptic transmission through a BDNF-dependent mechanism, and that VGF deficiency in mice impacts synaptic plasticity and memory in addition to depressive behavior. PMID:18815270

  1. The pro-domains of neurotrophins, including BDNF, are linked to Alzheimer's disease through a toxic synergy with Aβ.

    PubMed

    Lim, Jung Yeon; Reighard, Charles P; Crowther, Damian C

    2015-07-15

    Brain-derived neurotrophic factor (BDNF) has a crucial role in learning and memory by promoting neuronal survival and modulating synaptic connectivity. BDNF levels are lower in the brains of individuals with Alzheimer's disease (AD), suggesting a pathogenic involvement. The Drosophila orthologue of BDNF is the highly conserved Neurotrophin 1 (DNT1). BDNF and DNT1 have the same overall protein structure and can be cleaved, resulting in the conversion of a full-length polypeptide into separate pro- and mature-domains. While the BDNF mature-domain is neuroprotective, the role of the pro-domain is less clear. In flies and mammalian cells, we have identified a synergistic toxic interaction between the amyloid-β peptide (Aβ1-42) and the pro-domains of both DNT1 and BDNF. Specifically, we show that DNT1 pro-domain acquires a neurotoxic activity in the presence of Aβ1-42. In contrast, DNT1 mature-domain is protective against Aβ1-42 toxicity. Likewise, in SH-SY5Y cell culture, BDNF pro-domain is toxic only in the presence of Aβ1-42. Western blots indicate that this synergistic interaction likely results from the Aβ1-42-induced upregulation of the BDNF pro-domain receptor p75(NTR). The clinical relevance of these findings is underlined by a greater than thirty fold increase in the ratio of BDNF pro- to mature-domains in the brains of individuals with AD. This unbalanced BDNF pro:mature-domain ratio in patients represents a possible biomarker of AD and may offer a target for therapeutic intervention. PMID:25954034

  2. The pro-domains of neurotrophins, including BDNF, are linked to Alzheimer's disease through a toxic synergy with Aβ

    PubMed Central

    Lim, Jung Yeon; Reighard, Charles P.; Crowther, Damian C.

    2015-01-01

    Brain-derived neurotrophic factor (BDNF) has a crucial role in learning and memory by promoting neuronal survival and modulating synaptic connectivity. BDNF levels are lower in the brains of individuals with Alzheimer's disease (AD), suggesting a pathogenic involvement. The Drosophila orthologue of BDNF is the highly conserved Neurotrophin 1 (DNT1). BDNF and DNT1 have the same overall protein structure and can be cleaved, resulting in the conversion of a full-length polypeptide into separate pro- and mature-domains. While the BDNF mature-domain is neuroprotective, the role of the pro-domain is less clear. In flies and mammalian cells, we have identified a synergistic toxic interaction between the amyloid-β peptide (Aβ1–42) and the pro-domains of both DNT1 and BDNF. Specifically, we show that DNT1 pro-domain acquires a neurotoxic activity in the presence of Aβ1–42. In contrast, DNT1 mature-domain is protective against Aβ1–42 toxicity. Likewise, in SH-SY5Y cell culture, BDNF pro-domain is toxic only in the presence of Aβ1–42. Western blots indicate that this synergistic interaction likely results from the Aβ1–42-induced upregulation of the BDNF pro-domain receptor p75NTR. The clinical relevance of these findings is underlined by a greater than thirty fold increase in the ratio of BDNF pro- to mature-domains in the brains of individuals with AD. This unbalanced BDNF pro:mature-domain ratio in patients represents a possible biomarker of AD and may offer a target for therapeutic intervention. PMID:25954034

  3. Aromatase inhibition remodels the clonal architecture of estrogen-receptor-positive breast cancers.

    PubMed

    Miller, Christopher A; Gindin, Yevgeniy; Lu, Charles; Griffith, Obi L; Griffith, Malachi; Shen, Dong; Hoog, Jeremy; Li, Tiandao; Larson, David E; Watson, Mark; Davies, Sherri R; Hunt, Kelly; Suman, Vera J; Snider, Jacqueline; Walsh, Thomas; Colditz, Graham A; DeSchryver, Katherine; Wilson, Richard K; Mardis, Elaine R; Ellis, Matthew J

    2016-01-01

    Resistance to oestrogen-deprivation therapy is common in oestrogen-receptor-positive (ER+) breast cancer. To better understand the contributions of tumour heterogeneity and evolution to resistance, here we perform comprehensive genomic characterization of 22 primary tumours sampled before and after 4 months of neoadjuvant aromatase inhibitor (NAI) treatment. Comparing whole-genome sequencing of tumour/normal pairs from the two time points, with coincident tumour RNA sequencing, reveals widespread spatial and temporal heterogeneity, with marked remodelling of the clonal landscape in response to NAI. Two cases have genomic evidence of two independent tumours, most obviously an ER- 'collision tumour', which was only detected after NAI treatment of baseline ER+ disease. Many mutations are newly detected or enriched post treatment, including two ligand-binding domain mutations in ESR1. The observed clonal complexity of the ER+ breast cancer genome suggests that precision medicine approaches based on genomic analysis of a single specimen are likely insufficient to capture all clinically significant information. PMID:27502118

  4. Characterization of macrophage - cancer cell crosstalk in estrogen receptor positive and triple-negative breast cancer

    PubMed Central

    Hollmén, Maija; Roudnicky, Filip; Karaman, Sinem; Detmar, Michael

    2015-01-01

    Tumor heterogeneity may broadly influence the activation of tumor-associated macrophages. We aimed to dissect how breast cancer cells of different molecular characteristics contribute to macrophage phenotype and function. Therefore, we performed whole transcriptome sequencing of human monocytes that were co-cultured with estrogen receptor positive (ER+) or triple-negative (TNBC) breast cancer cell lines and studied the biological responses related to the differential gene activation in both monocytes and cancer cells by pathway analysis. ER+ and TNBC cancer cell lines induced distinctly different macrophage phenotypes with different biological functions, cytokine and chemokine secretion, and morphology. Conversely, ER+ and TNBC breast cancer cell lines were distinctly influenced by the presence of macrophages. ER+ cells demonstrated up-regulation of an acute phase inflammatory response, IL-17 signaling and antigen presentation pathway, whereas thioredoxin and vitamin D3 receptor pathways were down-regulated in the respective macrophages. The TNBC educated macrophages down-regulated citrulline metabolism and differentiated into M2-like macrophages with increased MMR protein expression and CCL2 secretion. These data demonstrate how different cancer cells educate the host cells to support tumor growth and might explain why high infiltration of macrophages in TNBC tumors associates with poor prognosis. PMID:25776849

  5. Targeted Therapies Overcoming Endocrine Resistance in Hormone Receptor-Positive Breast Cancer

    PubMed Central

    Almstedt, Katrin; Schmidt, Marcus

    2015-01-01

    Summary Breast cancer is a heterogeneous disease with different molecular subtypes. Most tumours are hormone receptor positive (luminal subtype) with potential endocrine responsiveness. Endocrine therapy is commonly used in these patients. Disease progression caused by endocrine resistance represents a significant challenge in the treatment of breast cancer. To understand the mechanisms of resistance of long-term oestrogen-deprived breast cancer cells, it is important to focus on cross-talk between steroid receptor signalling and other growth factor receptors and intracellular pathways. (Pre-)clinical trials showed that co-targeting these pathways can restore endocrine sensitivity. The focus of the current review is on the intracellular PI3K/AKT/mTOR signalling pathway and cyclin-dependant kinases (CDKs) in oestrogen receptor (ER)-positive breast cancer. Study results clearly show that both inhibition of the PI3K/AKT/mTOR pathway and CDK4/6 are promising ways to improve the efficacy of endocrine treatment in ER-positive breast cancer patients with comparably few side effects. Further clinical trials are needed to identify the patient population who would benefit most from a dual inhibition. PMID:26557821

  6. Aromatase inhibition remodels the clonal architecture of estrogen-receptor-positive breast cancers

    PubMed Central

    Miller, Christopher A.; Gindin, Yevgeniy; Lu, Charles; Griffith, Obi L; Griffith, Malachi; Shen, Dong; Hoog, Jeremy; Li, Tiandao; Larson, David E.; Watson, Mark; Davies, Sherri R; Hunt, Kelly; Suman, Vera J.; Snider, Jacqueline; Walsh, Thomas; Colditz, Graham A.; DeSchryver, Katherine; Wilson, Richard K.; Mardis, Elaine R.; Ellis, Matthew J.

    2016-01-01

    Resistance to oestrogen-deprivation therapy is common in oestrogen-receptor-positive (ER+) breast cancer. To better understand the contributions of tumour heterogeneity and evolution to resistance, here we perform comprehensive genomic characterization of 22 primary tumours sampled before and after 4 months of neoadjuvant aromatase inhibitor (NAI) treatment. Comparing whole-genome sequencing of tumour/normal pairs from the two time points, with coincident tumour RNA sequencing, reveals widespread spatial and temporal heterogeneity, with marked remodelling of the clonal landscape in response to NAI. Two cases have genomic evidence of two independent tumours, most obviously an ER− ‘collision tumour', which was only detected after NAI treatment of baseline ER+ disease. Many mutations are newly detected or enriched post treatment, including two ligand-binding domain mutations in ESR1. The observed clonal complexity of the ER+ breast cancer genome suggests that precision medicine approaches based on genomic analysis of a single specimen are likely insufficient to capture all clinically significant information. PMID:27502118

  7. Targeting BCL-2 to enhance vulnerability to therapy in estrogen receptor-positive breast cancer.

    PubMed

    Merino, D; Lok, S W; Visvader, J E; Lindeman, G J

    2016-04-14

    The last three decades have seen significant progress in our understanding of the role of the pro-survival protein BCL-2 and its family members in apoptosis and cancer. BCL-2 and other pro-survival family members including Mcl-1 and BCL-XL have been shown to have a key role in keeping pro-apoptotic 'effector' proteins BAK and BAX in check. They also neutralize a group of 'sensor' proteins (such as BIM), which are triggered by cytotoxic stimuli such as chemotherapy. BCL-2 proteins therefore have a central role as guardians against apoptosis, helping cancer cells to evade cell death. More recently, an increasing number of BH3 mimetics, which bind and neutralize BCL-2 and/or its pro-survival relatives, have been developed. The utility of targeting BCL-2 in hematological malignancies has become evident in early-phase studies, with remarkable clinical responses seen in heavily pretreated patients. As BCL-2 is overexpressed in ~75% of breast cancer, there has been growing interest in determining whether this new class of drug could show similar promise in breast cancer. This review summarizes our current understanding of the role of BCL-2 and its family members in mammary gland development and breast cancer, recent progress in the development of new BH3 mimetics as well as their potential for targeting estrogen receptor-positive breast cancer. PMID:26257067

  8. Optimal management of the premenopausal patient with estrogen receptor-positive breast cancer.

    PubMed

    Chojecki, Aleksander; Wong, Serena; Toppmeyer, Deborah

    2014-01-01

    Tamoxifen is the standard of care in the adjuvant treatment of premenopausal women with estrogen receptor-positive (ER+) breast cancer. Ovarian suppression (OS) is another method of endocrine therapy and has been shown to decrease the risk of recurrence and confer a survival advantage when used as the sole source of hormone therapy. However, there is no evidence that OS is superior to treatment with tamoxifen. Studies comparing OS with or without tamoxifen compared with chemotherapy have demonstrated comparable effects. There does not appear to be any additional benefit when OS is combined with chemotherapy, although there is a suggestion that there may be an effect in the subgroup of young women (aged younger than 40 years) who are least likely to experience chemotherapy-induced cessation of ovarian function. Interpretation of existing data is hampered by the lack of studies incorporating modern chemotherapy regimens and the absence of molecular analyses that would allow us to better define populations most likely to benefit from endocrine therapy. Last, the role of aromatase inhibitors (AI) in the premenopausal setting remains undefined. Two recent studies, SOFT and TEXT, aim to shed light on the effect of OS and AI in premenopausal ER+ breast cancer and are pending analysis. PMID:24857090

  9. The Intestinal Microbiome and Estrogen Receptor-Positive Female Breast Cancer.

    PubMed

    Kwa, Maryann; Plottel, Claudia S; Blaser, Martin J; Adams, Sylvia

    2016-08-01

    The huge communities of residential microbes, including bacteria, viruses, Archaea, and Eukaryotes, that colonize humans are increasingly recognized as playing important roles in health and disease. A complex populous ecosystem, the human gastrointestinal (GI) tract harbors up to 10(11) bacterial cells per gram of luminal content, whose collective genome, the gut metagenome, contains a vastly greater number of individual genes than the human genome. In health, the function of the microbiome might be considered to be in dynamic equilibrium with the host, exerting both local and distant effects. However, 'disequilibrium' may contribute to the emergence of disease, including malignancy. In this review, we discuss how the intestinal bacterial microbiome and in particular how an 'estrobolome,' the aggregate of enteric bacterial genes capable of metabolizing estrogens, might affect women's risk of developing postmenopausal estrogen receptor-positive breast cancer. Estrobolome composition is impacted by factors that modulate its functional activity. Exploring variations in the composition and activities of the estrobolome in healthy individuals and in women with estrogen-driven breast cancer may lead to development of microbiome-based biomarkers and future targeted interventions to attenuate cancer risk. PMID:27107051

  10. Vaginal estrogen products in hormone receptor-positive breast cancer patients on aromatase inhibitor therapy.

    PubMed

    Sulaica, Elisabeth; Han, Tiffany; Wang, Weiqun; Bhat, Raksha; Trivedi, Meghana V; Niravath, Polly

    2016-06-01

    Atrophic vaginitis represents a major barrier to compliance with aromatase inhibitor (AI) therapy in breast cancer (BC) survivors. While local estrogen therapy is effective for postmenopausal vaginal dryness, the efficacy of such therapies has not been evaluated systematically in hormone receptor-positive (HR+) BC patients on AI therapy. Furthermore, the potential risk of breast cancer recurrence with vaginal estrogen therapy represents a long-term safety concern for the patients with HR + BC. Unfortunately, there is no standardized assay to measure very low concentrations of estradiol (E2) in these women being treated with AI therapy. This makes it difficult to evaluate even indirectly the potential risk of BC recurrence with vaginal estrogen therapy in HR + BC patients on AI therapy. In this review, we describe available assays to measure very low concentrations of E2, discuss the Food and Drug Administration-approved vaginal estrogen products on the market, and summarize published and ongoing clinical trials evaluating the safety and efficacy of vaginal estrogen in HR + BC patients on AI therapy. In the absence of any randomized controlled clinical trials, this review serves as a summary of available clinical data and ongoing studies to aid clinicians in selecting the best available option for their patients. PMID:27178335

  11. The immune system and hormone-receptor positive breast cancer: Is it really a dead end?

    PubMed

    Dieci, Maria Vittoria; Griguolo, Gaia; Miglietta, Federica; Guarneri, Valentina

    2016-05-01

    Even if breast cancer has not been traditionally considered an immunogenic tumor, recent data suggest that immunity, and its interaction with tumor cells and tumor microenvironment, might play an important role in this malignancy, in particular in triple negative and HER2+ subtypes. As no consistent data on the potential clinical relevance of tumor infiltrating lymphocytes have been produced in hormone receptor positive (HR+) HER2- breast cancer, the interest in studying immune aspects in this subtype has become less appealing. Nevertheless, some scattered evidence indicates that immunity and inflammation may be implicated in the biology of this subtype as well. In HR+ breast cancer, the interaction between tumor cells and the immune milieu might rely on different mechanisms than in other BC subtypes, involving the modulation of the tumor microenvironment by mutual interplays of endocrine factors, pro-inflammatory status and immune cells. These subtle mechanisms may require more refined methods of evaluation, such as the assessment of tumor infiltrating lymphocytes subpopulations or gene signatures. In this paper we aim to perform a comprehensive review of pre-clinical and clinical data on the interplay between the immune system and breast cancer in the HR+ subtype, to guide further research in the field. PMID:27055087

  12. Functional Analysis of the p40 and p75 Proteins from Lactobacillus casei BL23

    PubMed Central

    Bäuerl, Christine; Pérez-Martínez, Gaspar; Yan, Fang; Polk, D. Brent; Monedero, Vicente

    2011-01-01

    The genomes of Lactobacillus casei/paracasei and Lactobacillus rhamnosus strains carry two genes encoding homologues of p40 and p75 from L. rhamnosus GG, two secreted proteins which display anti-apoptotic and cell protective effects on human intestinal epithelial cells. p40 and p75 carry cysteine, histidine-dependent aminohydrolase/peptidase (CHAP) and NLPC/P60 domains, respectively, which are characteristic of proteins with cell-wall hydrolase activity. In L. casei BL23 both proteins were secreted to the growth medium and were also located at the bacterial cell surface. The genes coding for both proteins were inactivated in this strain. Inactivation of LCABL_00230 (encoding p40) did not result in a significant difference in phenotype, whereas a mutation in LCABL_02770 (encoding p75) produced cells that formed very long chains. Purified glutathione-S-transferase (GST)-p40 and -p75 fusion proteins were able to hydrolyze the muropeptides from L. casei cell walls. Both fusions bound to mucin, collagen and to intestinal epithelial cells and, similar to L. rhamnosus GG p40, stimulated epidermal growth factor receptor phosphorylation in mouse intestine ex vivo. These results indicate that extracellular proteins belonging to the machinery of cell-wall metabolism in the closely related L. casei/paracasei-L. rhamnosus group are most likely involved in the probiotic effects described for these bacteria PMID:21178363

  13. Functional analysis of the p40 and p75 proteins from Lactobacillus casei BL23.

    PubMed

    Bäuerl, Christine; Pérez-Martínez, Gaspar; Yan, Fang; Polk, D Brent; Monedero, Vicente

    2010-01-01

    The genomes of Lactobacillus casei/paracasei and Lactobacillus rhamnosus strains carry two genes encoding homologues of p40 and p75 from L. rhamnosus GG, two secreted proteins which display anti-apoptotic and cell protective effects on human intestinal epithelial cells. p40 and p75 carry cysteine, histidine-dependent aminohydrolase/peptidase (CHAP) and NLPC/P60 domains, respectively, which are characteristic of proteins with cell-wall hydrolase activity. In L. casei BL23 both proteins were secreted to the growth medium and were also located at the bacterial cell surface. The genes coding for both proteins were inactivated in this strain. Inactivation of LCABL_00230 (encoding p40) did not result in a significant difference in phenotype, whereas a mutation in LCABL_02770 (encoding p75) produced cells that formed very long chains. Purified glutathione-S-transferase (GST)-p40 and -p75 fusion proteins were able to hydrolyze the muropeptides from L. casei cell walls. Both fusions bound to mucin, collagen and to intestinal epithelial cells and, similar to L. rhamnosus GG p40, stimulated epidermal growth factor receptor phosphorylation in mouse intestine ex vivo. These results indicate that extracellular proteins belonging to the machinery of cell-wall metabolism in the closely related L. casei/paracasei-L. rhamnosus group are most likely involved in the probiotic effects described for these bacteria. PMID:21178363

  14. Nuclear protein LEDGF/p75 recognizes supercoiled DNA by a novel DNA-binding domain

    PubMed Central

    Tsutsui, Kimiko M.; Sano, Kuniaki; Hosoya, Osamu; Miyamoto, Tadashi; Tsutsui, Ken

    2011-01-01

    Lens epithelium-derived growth factor (LEDGF) or p75 is a co-activator of general transcription and also involved in insertion of human immunodeficiency virus type I (HIV-1) cDNA into host cell genome, which occurs preferentially to active transcription units. These phenomena may share an underlying molecular mechanism in common. We report here that LEDGF/p75 binds negatively supercoiled DNA selectively over unconstrained DNA. We identified a novel DNA-binding domain in the protein and termed it ‘supercoiled DNA-recognition domain’ (SRD). Recombinant protein fragments containing SRD showed a preferential binding to supercoiled DNA in vitro. SRD harbors a characteristic cluster of lysine and glutamic/aspartic acid residues. A polypeptide mimicking the cluster (K9E9K9) also showed this specificity, suggesting that the cluster is an essential element for the supercoil recognition. eGFP-tagged LEDGF/p75 expressed in the nucleus distributed partially in transcriptionally active regions that were identified by immunostaining of methylated histone H3 (H3K4me3) or incorporation of Br-UTP. This pattern of localization was observed with SRD alone but abolished if the protein lacked SRD. Thus, these results imply that LEDGF/p75 guides its binding partners, including HIV-1 integrase, to the active transcription site through recognition of negative supercoils generated around it. PMID:21345933

  15. Recent Advances in the Development of Small-Molecular Inhibitors Target HIV Integrase-LEDGF/p75 Interaction.

    PubMed

    Zhao, Yu; Luo, Zaigang

    2015-01-01

    Lens epithelium-derived growth factor (LEDGF/p75) plays an essential role in the HIV-1 replication. It acts by tethering integrase (IN) into the host cellular chromatin. Due to its significance of the IN-LEDGF/p75 interaction affords a novel therapeutic approach for the design of new classes of antiretroviral agents. To date, many small molecules have been found to be the inhibitors of INLEDGF/ p75 interaction. This review summarizes recent advances in the development of potential structure-based IN-LEDGF/p75 interaction inhibitors. The work will be helpful to shed light on the antiretroviral drug development pipeline in the next future. PMID:26156421

  16. Cytokine/neurotrophin interaction in the aged central nervous system

    PubMed Central

    MACDONALD, NANCY J.; DECORTI, FRANCESCO; PAPPAS, TODD C.; TAGLIALATELA, GIULIO

    2000-01-01

    Age-associated neurodegenerative diseases such as Alzheimer's disease are characterised by neuronal impairment that leads to cognitive deficits. As certain affected neurons depend on trophic factors such as neurotrophins (NTs), impairment in NT function has been suggested to be a component of neuronal damage associated with such disorders. Age-related neurodegenerative diseases are also characterised by high levels of proinflammatory cytokines such as tumour necrosis factor alpha (TNFα) in the CNS. Because TNFα receptors and certain NT receptors share a high degree of homology and are capable of activating similar signalling pathways, one possibility is that altered cytokine levels may affect NT function in the aged or diseased CNS. Here we wish briefly to review the evidence suggesting a role for cytokine and NT in the onset of age-associated neurodegenerative diseases. We propose that cytokine/NT interactions may alter neuronal homeostasis, thus possibly contributing to some of the neuronal degeneration occurring during such age-associated CNS diseases. PMID:11197527

  17. Matrix interactions modulate neurotrophin-mediated neurite outgrowth and pathfinding

    PubMed Central

    Madl, Christopher M.; Heilshorn, Sarah C.

    2015-01-01

    Both matrix biochemistry and neurotrophic factors are known to modulate neurite outgrowth and pathfinding; however, the interplay between these two factors is less studied. While previous work has shown that the biochemical identity of the matrix can alter the outgrowth of neurites in response to neurotrophins, the importance of the concentration of cell-adhesive ligands is unknown. Using engineered elastin-like protein matrices, we recently demonstrated a synergistic effect between matrix-bound cell-adhesive ligand density and soluble nerve growth factor treatment on neurite outgrowth from dorsal root ganglia. This synergism was mediated by Schwann cell-neurite contact through L1CAM. Cell-adhesive ligand density was also shown to alter the pathfinding behavior of dorsal root ganglion neurites in response to a gradient of nerve growth factor. While more cell-adhesive matrices promoted neurite outgrowth, less cell-adhesive matrices promoted more faithful neurite pathfinding. These studies emphasize the importance of considering both matrix biochemistry and neurotrophic factors when designing biomaterials for peripheral nerve regeneration. PMID:26170800

  18. HER-2/neu protein-receptor-positive breast carcinoma: an immunologic perspective.

    PubMed

    Brown, R E; Bernath, A M; Lewis, G O

    2000-07-01

    Immunotherapy using a monoclonal antibody against the human epidermal growth factor receptor 2 protein, HER-2/neu, has proven to be clinically efficacious in about one-half of breast cancer patients who exhibit strong (3+) plasmalemmal immunoreactivity for this protein. The tumoricidal effect of this antibody relies in part upon antibody-dependent cell-mediated cytotoxicity. This report provides observations on certain factors or circumstances which could have an impact on this aspect of the therapeutic approach. These include: (1) concurrent medications; (2) the composition (immunophenotype) of peritumoral lymphocytes and the generally limited numbers of intratumoral T-lymphocytes/natural killer (NK) cells, monocytes, and neutrophilic granulocytes; (3) the presence of circulating HER-2/neu antigens which might bind the exogenous antibody and lead to immune complex formation; (4) the variable co-expression in the tumor of cytokines known to downregulate NK cell function (ie, transforming growth factor-beta1 [TGF-beta1] and platelet-derived growth factor [PDGF]-AB); and (5) the tumoral and/or stromal immunoreactivity for angiotensin-converting enzyme, which forms a part of one of the pathways for the activation of latent TGF-beta1 and for the biosynthesis of PDGF-AB. These observations provide an immunologic perspective for the use of monoclonal antibody therapy in HER-2/neu protein-receptor-positive breast carcinoma and suggest a role for the clinical laboratory in identifying potential avenues for additional manipulations of the immune system in individual cases in order to enhance the therapeutic response. PMID:10945564

  19. Endocrine therapy initiation among Medicaid-insured breast cancer survivors with hormone receptor-positive tumors

    PubMed Central

    Wheeler, Stephanie Brooke; Kohler, Racquel Elizabeth; Reeder-Hayes, Katherine Elizabeth; Goyal, Ravi K.; Lich, Kristen Hassmiller; Moore, Alexis; Smith, Timothy W.; Melvin, Cathy L.; Muss, Hyman Bernard

    2016-01-01

    Purpose Hormone receptor positive (HR+) cancers account for most breast cancer diagnoses and deaths. Among survivors with HR+ breast cancers, endocrine therapy (ET) reduces 5-year risk of recurrence by up to 40%. Observational studies in Medicare and privately-insured survivors suggest under-utilization of ET. We sought to characterize ET use in a low-income Medicaid-insured population in North Carolina. Methods Medicaid claims data were matched to state cancer registry records for survivors ages 18–64 diagnosed with stage 0-II HR+ breast cancer from 2003–2007, eligible for ET, and enrolled in Medicaid for at least 12 of 15 months post-diagnosis. We used multivariable logistic regression to model receipt of any ET medication during 15-months post-diagnosis controlling for age, race, tumor characteristics, receipt of other treatments, co-morbidity, residence, reason for Medicaid eligibility, involvement in the Breast and Cervical Cancer Control Program (BCCCP), and diagnosis year. Results Of 222 women meeting inclusion criteria, only 50% filled a prescription for ET. Involvement in BCCCP and earlier year of diagnoses were associated with significantly higher odds of initiating guideline-recommended ET (Adjusted Odds Ratio [AOR] for BCCCP: 3.76, 95%CI: 1.67–8.48; AOR for 2004 relative to 2007: 2.80, 95%CI: 1.03–7.62; AOR for 2005 relative to 2007: 2.11, 95%CI: 0.92–4.85). Conclusions Results suggest substantial under-utilization of ET in this population. Interventions are needed to improve timely receipt of ET and to better support survivors taking ET. Implications of cancer survivors Low-income survivors should be counseled on the importance of ET and offered support services to promote initiation and long-term adherence. PMID:24866922

  20. Glycone-rich Soy Isoflavone Extracts Promote Estrogen Receptor Positive Breast Cancer Cell Growth.

    PubMed

    Johnson, Kailee A; Vemuri, Sravan; Alsahafi, Sameerh; Castillo, Rudy; Cheriyath, Venugopalan

    2016-01-01

    Due to the association of hormone replacement therapy (HRT) with breast cancer risk, estrogenically active soy isoflavones are considered as an HRT alternative to alleviate menopausal symptoms. However, several recent reports challenged the health benefits of soy isoflavones and associated them with breast cancer promotion. While glyconic isoflavones are the major constituents of soybean seeds, due to their low cell permeability, they are considered to be biologically inactive. The glyconic isoflavones may exert their effects on membrane-bound estrogen receptors or could be converted to aglycones by extracellular β-glucosidases. Therefore, we hypothesized that despite their low cell permeability, soybean cultivars with high glyconic isoflavones may promote breast cancer cell growth. To test this, composition and estrogenic activity of isoflavones from 54 commercial soybean cultivars were determined. Soybean seeds produced in identical climate and growth conditions were used to minimize the effects of extraneous factors on isoflavone profile and concentrations. The glyconic daidzin concentration negatively correlated with genistin and with other aglycones. Relative to control, isoflavone extracts from 51 cultivars were estrogenic and promoted the growth of estrogen receptor positive (ER+) breast cancer cell line MCF-7 from 1.14 to 4.59 folds and other three cultivars slightly reduced the growth. Among these, extracts from three cultivars were highly estrogenic and promoted MCF-7 cell growth by 2.59-4.64 folds (P<0.005). Among six isoflavones, daidzin was positively associated with MCF-7 cell growth (P<0.005, r = 0.13966), whereas the negative correlation between genistin and MCF-7 cell growth was nearly significant (P≤0.0562, r = -0.026141). Furthermore, in drug interaction studies daidzin-rich isoflavone extracts antagonized tamoxifen, an ER inhibitor. Taken together, our results suggest that the glyconic daidzin-rich soy isoflavone extracts may exert estrogenic

  1. Predicting prognosis using molecular profiling in estrogen receptor-positive breast cancer treated with tamoxifen

    PubMed Central

    Loi, Sherene; Haibe-Kains, Benjamin; Desmedt, Christine; Wirapati, Pratyaksha; Lallemand, Françoise; Tutt, Andrew M; Gillet, Cheryl; Ellis, Paul; Ryder, Kenneth; Reid, James F; Daidone, Maria G; Pierotti, Marco A; Berns, Els MJJ; Jansen, Maurice PHM; Foekens, John A; Delorenzi, Mauro; Bontempi, Gianluca; Piccart, Martine J; Sotiriou, Christos

    2008-01-01

    Background Estrogen receptor positive (ER+) breast cancers (BC) are heterogeneous with regard to their clinical behavior and response to therapies. The ER is currently the best predictor of response to the anti-estrogen agent tamoxifen, yet up to 30–40% of ER+BC will relapse despite tamoxifen treatment. New prognostic biomarkers and further biological understanding of tamoxifen resistance are required. We used gene expression profiling to develop an outcome-based predictor using a training set of 255 ER+ BC samples from women treated with adjuvant tamoxifen monotherapy. We used clusters of highly correlated genes to develop our predictor to facilitate both signature stability and biological interpretation. Independent validation was performed using 362 tamoxifen-treated ER+ BC samples obtained from multiple institutions and treated with tamoxifen only in the adjuvant and metastatic settings. Results We developed a gene classifier consisting of 181 genes belonging to 13 biological clusters. In the independent set of adjuvantly-treated samples, it was able to define two distinct prognostic groups (HR 2.01 95%CI: 1.29–3.13; p = 0.002). Six of the 13 gene clusters represented pathways involved in cell cycle and proliferation. In 112 metastatic breast cancer patients treated with tamoxifen, one of the classifier components suggesting a cellular inflammatory mechanism was significantly predictive of response. Conclusion We have developed a gene classifier that can predict clinical outcome in tamoxifen-treated ER+ BC patients. Whilst our study emphasizes the important role of proliferation genes in prognosis, our approach proposes other genes and pathways that may elucidate further mechanisms that influence clinical outcome and prediction of response to tamoxifen. PMID:18498629

  2. Identification and clinical implications of circulating microRNAs for estrogen receptor-positive breast cancer.

    PubMed

    Park, In Hae; Kang, Joo Hyun; Lee, Keun Seok; Nam, Seungyoon; Ro, Jungsil; Kim, Joo-Hang

    2014-12-01

    Cancer-associated microRNAs have been stably detected in blood. The objective of this study was to identify a panel of circulating microRNAs with the potential to serve as biomarkers for estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2 (HER2)- breast cancer. We used microarray-based expression profiling to compare the levels of circulating microRNAs in blood samples from 11 ER+/HER2- advanced breast cancer patients plus 5 age-matched controls. MicroRNA levels were validated by reverse transcription quantitative polymerase chain reaction in 40 control subjects, 187 early breast cancer patients, and 45 metastatic breast cancer patients. Then, we assessed the association between the levels of microRNA and clinical outcomes of ER+/HER2- metastatic breast cancer. Initially, we found that miR-1280, miR-1260, and miR-720 were up-regulated in blood from breast cancer patients (P < 0.05). In validation, miR-1280 levels significantly increased in breast cancer patients and reflected tumor status (control

  3. Neuroprotection trek--the next generation: neuromodulation II. Applications--epilepsy, nerve regeneration, neurotrophins

    NASA Technical Reports Server (NTRS)

    Andrews, Russell J.

    2003-01-01

    Three examples of neuroprotective applications of electrical stimulation-neuromodulation-are considered: (1) the diagnosis and treatment of epilepsy, (2) the augmentation of peripheral nerve regeneration after transection, and (3) the interaction between electrical stimulation and neurotrophins (notably brain derived neurotrophic factor [BDNF]) in various neuroprotective situations. The research cited demonstrates clear benefit from appropriate electrical stimulation in the treatment of (1) certain patients with medication-refractory epilepsy, and (2) the functional regeneration of peripheral nerves after transection and surgical repair. Furthermore, neuromodulation of peripheral nerve regeneration has been associated with an increase in the neurotrophin BDNF. The roles of BDNF and other neurotrophins in several disorders of the nervous system are discussed in the context of neuromodulation and its augmentation of neurotrophins. Neuromodulation-at least in part through its effect on BDNF and other neurotrophins-will likely play a major role in the treatment (and possibly prevention) of disorders of the nervous system for which neuroproteive pharmacologic agents have traditionally been sought.

  4. Schwann cells genetically modified to express neurotrophins promote spiral ganglion neuron survival in vitro

    PubMed Central

    Pettingill, Lisa N.; Minter, Ricki L.; Shepherd, Robert K.

    2009-01-01

    The intracochlear infusion of neurotrophic factors via a mini-osmotic pump has been shown to prevent deafness-induced spiral ganglion neuron (SGN) degeneration; however, the use of pumps may increase the incidence of infection within the cochlea, making this technique unsuitable for neurotrophin administration in a clinical setting. Cell- and gene-based therapies are potential therapeutic options. This study investigated whether Schwann cells which were genetically modified to over-express the neurotrophins brain-derived neurotrophic factor (BDNF) or neurotrophin 3 (Ntf3, formerly NT-3) could support SGN survival in an in vitro model of deafness. Co-culture of either BDNF over-expressing Schwann cells or Ntf3 over-expressing Schwann cells with SGNs from early postnatal rats significantly enhanced neuronal survival in comparison to both control Schwann cells and conventional recombinant neurotrophin proteins. Transplantation of neurotrophin over-expressing Schwann cells into the cochlea may provide an alternative means of delivering neurotrophic factors to the deaf cochlea for therapeutic purposes. PMID:18304740

  5. Neurotrophin-3 mRNA a putative target of miR21 following status epilepticus

    PubMed Central

    Risbud, Rashmi M.; Lee, Carolyn; Porter, Brenda E.

    2014-01-01

    Status epilepticus induces a cascade of protein expression changes contributing to the subsequent development of epilepsy. By identifying the cascade of molecular changes that contribute to the development of epilepsy we hope to be able to design therapeutics for preventing epilepsy. MicroRNAs influence gene expression by altering mRNA stability and/or translation and have been implicated in the pathology of multiple diseases. MiR21 and its co-transcript miR21*, microRNAs produced from either the 5″ or 3′ ends of the same precursor RNA strand, are increased in the hippocampus following status epilepticus. We have identified a miR21 binding site, in the 3′ UTR of neurotrophin-3 that inhibits translation. Neurotrophin-3 mRNA levels decrease in the hippocampus following SE concurrent with the increase in miR21. MiR21 levels in cultured hippocampal neurons inversely correlate with neurotrophin-3 mRNA levels. Treatment of hippocampal neuronal cultures with excess K+Cl−, a depolarizing agent mimicking the episode of status epilepticus, also results in an increase in miR21 and a decrease in neurotrophin-3 mRNA. MiR21 is a candidate for regulating neurotrophin-3 signaling in the hippocampus following status epilepticus. PMID:22019057

  6. Cytokine Spätzle binds to the Drosophila immunoreceptor Toll with a neurotrophin-like specificity and couples receptor activation

    PubMed Central

    Lewis, Miranda; Arnot, Christopher J.; Beeston, Helen; McCoy, Airlie; Ashcroft, Alison E.; Gay, Nicholas J.; Gangloff, Monique

    2013-01-01

    Drosophila Toll functions in embryonic development and innate immunity and is activated by an endogenous ligand, Spätzle (Spz). The related Toll-like receptors in vertebrates also function in immunity but are activated directly by pathogen-associated molecules such as bacterial endotoxin. Here, we present the crystal structure at 2.35-Å resolution of dimeric Spz bound to a Toll ectodomain encompassing the first 13 leucine-rich repeats. The cystine knot of Spz binds the concave face of the Toll leucine-rich repeat solenoid in an area delineated by N-linked glycans and induces a conformational change. Mutagenesis studies confirm that the interface observed in the crystal structure is relevant for signaling. The asymmetric binding mode of Spz to Toll is similar to that of nerve growth factor (NGF) in complex with the p75 neurotrophin receptor but is distinct from that of microbial ligands bound to the Toll-like receptors. Overall, this study indicates an allosteric signaling mechanism for Toll in which ligand binding to the N terminus induces a conformational change that couples to homodimerization of juxtamembrane structures in the Toll ectodomain C terminus. PMID:24282309

  7. Bilirubin as an endogenous modulator of neurotrophin redox signaling.

    PubMed

    Mancuso, Cesare; Capone, Caterina; Ranieri, Sofia Chiatamone; Fusco, Salvatore; Calabrese, Vittorio; Eboli, Maria Luisa; Preziosi, Paolo; Galeotti, Tommaso; Pani, Giovambattista

    2008-08-01

    Bilirubin is neurotoxic upon excess accumulation in the brain, but it also plays important physiological roles related to its antioxidant properties. Here we report that exposure of PC12 and primary rat cerebellar granule neurons to bilirubin (0.5-10 microM) drastically decreases nerve growth factor (NGF)/brain-derived neurotrophic factor signaling to Akt and extracellular signal-regulated kinases (ERKs), indicating a direct interference of the molecule with crucial prosurvival signaling pathways. This effect likely involves the scavenging capacity of bilirubin, the latter being able to inhibit, in PC12 cells, accumulation of intracellular reactive oxygen species and phosphorylation of Akt and ERKs in response to extracellular hydrogen peroxide. Interestingly, in the absence of exogenous growth factor, bilirubin elicited the phosphorylation of ERKs and of the cAMP responsive element binding (CREB) transcription factor, a signature of NGF-dependent survival signaling. These growth factor-like signaling effects were paralleled by the induction of the neuronal nitric oxide synthase (nNOS) and generation of nitric oxide (NO). Pharmacological dissection of the signaling cascade triggered by bilirubin revealed that phosphorylation of ERKs requires NO signaling through soluble guanylyl cyclase, and, further upstream, influx of extracellular calcium is necessary for nNOS induction and NO release, likely through calcium-dependent phosphorylation of CREB. Importantly, the cascade elicited by bilirubin through NO and ERK is cytoprotective, as revealed by exacerbated bilirubin toxicity in cultures treated by either NOS or MEK inhibitors. Taken together, these observations indicate an important action of bilirubin on redox signaling by neurotrophins, with either inhibitory or agonistic effects based on growth factor availability. PMID:18338802

  8. Physical activity and memory functions: are neurotrophins and cerebral gray matter volume the missing link?

    PubMed

    Flöel, A; Ruscheweyh, R; Krüger, K; Willemer, C; Winter, B; Völker, K; Lohmann, H; Zitzmann, M; Mooren, F; Breitenstein, C; Knecht, S

    2010-02-01

    Epidemiological studies reveal better cognitive function in physically active individuals. Possible mediators for this effect are neurotrophins, which are up-regulated through physical exercise and induce neuronal growth and synaptogenesis in the animal model. Here we cross-sectionally assessed 75 healthy older individuals for levels of physical activity, aerobic fitness, and memory encoding, as well as neurotrophin levels and cerebral gray matter volume. We found that physical activity, but not cardiovascular fitness, was associated with better memory encoding after controlling for age, sex, education, depression, alcohol consumption, and smoking. Higher levels of physical activity were associated with higher levels of the neurotrophin granulocyte colony stimulating factor (G-CSF) and increased cerebral gray matter volume in prefrontal and cingulate cortex as assessed by magnetic resonance voxel-based morphometry. While mediating factors will need to be further elucidated, these findings indicate that even low-level physical activity exerts beneficial effects on memory functions in older individuals. PMID:19853041

  9. Expression of neurotransmitters and neurotrophins in neurogenic inflammation of the rat retina.

    PubMed

    Bronzetti, Elena; Artico, M; Kovacs, I; Felici, L M; Magliulo, G; Vignone, D; D'Ambrosio, A; Forte, F; Di Liddo, R; Feher, J

    2007-01-01

    Antidromic stimulation of the rat trigeminal ganglion triggers the release of substance P (SP) and calcitonin gene-related peptide (CGRP) from sensory nerve terminals of the capsaicin sensitive C-fibers. These pro-inflammatory neuropeptides produce a marked hyperemia in the anterior segment of the eye, accompanied by increased intraocular pressure, breakdown of the blood-aqueous barrier and myosis. To assess the effects of neurogenic inflammation on the retina, specifically on the immunostaining of neurotransmitters and neurotrophins, as well as on the expression of neurotrophin receptors in the retina. RT-PCR was also accomplished in control and stimulated animals to confirm the immunohistochemical results. In the electrically stimulated eyes, immunostaining for SP, CGRP, VIP and nNOS demonstrated a marked increase in the RPE/POS (Retinal Pigment Epithelium/Photoreceptor Outer Segments), in the inner and outer granular layers and in the ganglion cells in comparison to the control eyes. CGRP and SP were found increased in stimulated animals and this result has been confirmed by RT- PCR. Changes in neurotrophin immunostaining and in receptor expression were also observed after electric stimulation of trigeminal ganglia. Decrease of BDNF and NT4 in the outer and inner layers and in ganglion cells was particularly marked. In stimulated rat retinas immunostaining and RT-PCR showed a NGF expression increase. Neurotrophin receptors remained substantially unchanged. These studies demonstrated, for the first time, that antidromic stimulation of the trigeminal ganglion and subsequent neurogenic inflammation affect immunostaining of retinal cell neurotransmitter/neuropeptides and neurotrophins as well as the expression of neurotrophin receptors. PMID:18162454

  10. Association of p75NTR and α9β1 integrin modulates NGF-dependent cellular responses

    PubMed Central

    Ventresca, Erin M.; Lecht, Shimon; Jakubowski, Piotr; Chiaverelli, Rachel A.; Weaver, Michael; Del Valle, Luis; Ettinger, Keren; Gincberg, Galit; Priel, Avi; Braiman, Alex; Lazarovici, Philip; Lelkes, Peter I.; Marcinkiewicz, Cezary

    2015-01-01

    Direct interaction of α9βl integrin with nerve growth factor (NGF) has been previously reported to induce pro-proliferative and pro-survival activities of non-neuronal cells. We investigated participation of p75NTR in α9βl integrin-dependent cellular response to NGF stimulation. Using selective transfection of glioma cell lines with these receptors, we showed a strong, cation-independent association of α9 integrin subunit with p75NTR on the cellular membrane by selective immunoprecipitation experiments. Presence of the α9/p75NTR complex increases NGF-dependent cell adhesion, proliferation and migration. Other integrin subunits including β1 were not found in complex with p75NTR. FRET analysis indicated that p75NTR and α9 integrin subunit are not closely associated through their cytoplasmic domains, most probably because of the molecular interference with other cytoplasmic proteins such as paxillin. Interaction of α9βl integrin with another ligand, VCAM-1 was not modulated by the p75NTR. α9/p75NTR complex elevated NGF-dependent activation of MAPK Erk1/2 arty for integrin that may create active complexes with other types of receptors belonging to the TNF superfamily. PMID:25748048

  11. Association of p75(NTR) and α9β1 integrin modulates NGF-dependent cellular responses.

    PubMed

    Ventresca, Erin M; Lecht, Shimon; Jakubowski, Piotr; Chiaverelli, Rachel A; Weaver, Michael; Del Valle, Luis; Ettinger, Keren; Gincberg, Galit; Priel, Avi; Braiman, Alex; Lazarovici, Philip; Lelkes, Peter I; Marcinkiewicz, Cezary

    2015-06-01

    Direct interaction of α9β1 integrin with nerve growth factor (NGF) has been previously reported to induce pro-proliferative and pro-survival activities of non-neuronal cells. We investigated participation of p75(NTR) in α9β1 integrin-dependent cellular response to NGF stimulation. Using selective transfection of glioma cell lines with these receptors, we showed a strong, cation-independent association of α9 integrin subunit with p75(NTR) on the cellular membrane by selective immunoprecipitation experiments. The presence of the α9/p75(NTR) complex increases NGF-dependent cell adhesion, proliferation and migration. Other integrin subunits including β1 were not found in complex with p75(NTR). FRET analysis indicated that p75(NTR) and α9 integrin subunit are not closely associated through their cytoplasmic domains, most probably because of the molecular interference with other cytoplasmic proteins such as paxillin. Interaction of α9β1 integrin with another ligand, VCAM-1 was not modulated by the p75(NTR). α9/p75(NTR) complex elevated NGF-dependent activation of MAPK Erk1/2 arty for integrin that may create active complexes with other types of receptors belonging to the TNF superfamily. PMID:25748048

  12. Structure, mechanics, and binding mode heterogeneity of LEDGF/p75-DNA nucleoprotein complexes revealed by scanning force microscopy

    NASA Astrophysics Data System (ADS)

    Vanderlinden, Willem; Lipfert, Jan; Demeulemeester, Jonas; Debyser, Zeger; de Feyter, Steven

    2014-04-01

    LEDGF/p75 is a transcriptional coactivator implicated in the pathogenesis of AIDS and leukemia. In these contexts, LEDGF/p75 acts as a cofactor by tethering protein cargo to transcriptionally active regions in the human genome. Our study - based on scanning force microscopy (SFM) imaging - is the first to provide structural information on the interaction of LEDGF/p75 with DNA. Two novel approaches that allow obtaining insights into the DNA conformation inside nucleoprotein complexes revealed (1) that LEDGF/p75 can bind at least in three different binding modes, (2) how DNA topology and protein dimerization affect these binding modes, and (3) geometrical and mechanical aspects of the nucleoprotein complexes. These structural and mechanical details will help us to better understand the cellular mechanisms of LEDGF/p75 as a transcriptional coactivator and as a cofactor in disease.LEDGF/p75 is a transcriptional coactivator implicated in the pathogenesis of AIDS and leukemia. In these contexts, LEDGF/p75 acts as a cofactor by tethering protein cargo to transcriptionally active regions in the human genome. Our study - based on scanning force microscopy (SFM) imaging - is the first to provide structural information on the interaction of LEDGF/p75 with DNA. Two novel approaches that allow obtaining insights into the DNA conformation inside nucleoprotein complexes revealed (1) that LEDGF/p75 can bind at least in three different binding modes, (2) how DNA topology and protein dimerization affect these binding modes, and (3) geometrical and mechanical aspects of the nucleoprotein complexes. These structural and mechanical details will help us to better understand the cellular mechanisms of LEDGF/p75 as a transcriptional coactivator and as a cofactor in disease. Electronic supplementary information (ESI) available: SFM topographs of phage lambda DNA in situ, in the absence and presence of LEDGF/p75; model-independent tests for DNA chain equilibration in 2D; SFM topographs of

  13. Semaphorin 3A and neurotrophins: a balance between apoptosis and survival signaling in embryonic DRG neurons.

    PubMed

    Ben-Zvi, Ayal; Yagil, Zohar; Hagalili, Yamit; Klein, Hagit; Lerman, Omer; Behar, Oded

    2006-01-01

    Large numbers of neurons are eliminated by apoptosis during nervous system development. For instance, in the mouse dorsal root ganglion (DRG), the highest incidence of cell death occurs between embryonic days 12 and 14 (E12-E14). While the cause of cell death and its biological significance in the nervous system is not entirely understood, it is generally believed that limiting quantities of neurotrophins are responsible for neuronal death. Between E12 and E14, developing DRG neurons pass through tissues expressing high levels of axonal guidance molecules such as Semaphorin 3A (Sema3A) while navigating to their targets. Here, we demonstrate that Sema3A acts as a death-inducing molecule in neurotrophin-3 (NT-3)-, brain-derived neurotrophic factor (BDNF)- and nerve growth factor (NGF)-dependent E12 and E13 cultured DRG neurons. We show that Sema3A most probably induces cell death through activation of the c-Jun N-terminal kinase (JNK)/c-Jun signaling pathway, and that this cell death is blocked by a moderate increase in NGF concentration. Interestingly, increasing concentrations of other neurotrophic factors, such as NT-3 or BDNF, do not elicit similar effects. Our data suggest that the number of DRG neurons is determined by a fine balance between neurotrophins and Semaphorin 3A, and not only by neurotrophin levels. PMID:16336628

  14. NEUROTROPHIN RECEPTOR BLOCKADE ATTENUATES DIESEL EXHAUST PARTICULATE MATTER (DEP) ENHANCEMENT OF ALLERGIC RESPONSES

    EPA Science Inventory

    ABSTRACT BODY:
    Recent investigations have linked neurotrophins including NGF, NT-3, and BDNF to allergic airways diseases. Antibody blockade of NGF attenuates airway resistance associated with allergic airway responses in mice. Mice administered an antibody against the low aff...

  15. Electrical Stimulation Promotes Peripheral Axon Regeneration By Enhanced Neuronal Neurotrophin Signaling

    PubMed Central

    English, Arthur W.; Schwartz, Gail; Meador, William; Sabatier, Manning J.; Mulligan, Amanda

    2016-01-01

    Electrical stimulation of cut peripheral nerves at the time of their surgical repair results in an enhancement of axon regeneration. Regeneration of axons through nerve allografts was used to evaluate whether this effect is due to an augmentation of cell autonomous neurotrophin signaling in the axons or signaling from neurotrophins produced in the surrounding environment. In the thy-1-YFP-H mouse, a single one hour application of electrical stimulation at the time of surgical repair of the cut common fibular nerve results in a significant increase in the proportion of YFP+ dorsal root ganglion neurons that were also immunoreactive for BDNF or trkB as well as an increase in the length of regenerating axons through allografts from wild type litter mates, both one and two weeks later. Axon growth through allografts from neurotrophin-4/5 knockout mice or grafts made acellular by repeated cycles of freezing and thawing is normally very poor, but electrical stimulation results in a growth of axons through these grafts which is similar to that observed through grafts from wild type mice after electrical stimulation. When cut nerves in NT-4/5 knockout mice were electrically stimulated, no enhancement of axon regeneration was found. Electrical stimulation thus produces a potent enhancement of the regeneration of axons in cut peripheral nerves which is independent of neurotrophin production by cells in their surrounding environment but is dependent on stimulation of trkB and its ligands in the regenerating axons themselves. PMID:17443780

  16. Expression of the TrkB neurotrophin receptor by thymic macrophages.

    PubMed Central

    García-Suárez, O; Hannestad, J; Esteban, I; Sainz, R; Naves, F J; Vega, J A

    1998-01-01

    Increasing evidence suggests that some members of the neurotrophic factor family of neurotrophins could be implicated in the regulation of immune responses. Neurotrophins, as well as their tyrosine kinase signal-transducing receptors (the so-called Trk neurotrophin receptors), have been detected in different lymphoid tissues, although their cellular localization is not well known. In this study we used single and double immunohistochemistry to localize TrkB in situ in the rat thymus (in animals from 0 days to 2 years of age), in cytospin preparations of rat thymic cells, and in two mouse monocyte-macrophage cell lines (RAW 264.7 and J774A.1). We found TrkB protein expression in a subpopulation of cells in the corticomedullary junction, which simultaneously expressed the rat macrophage marker ED1. The density of TrkB-expressing cells increased with age, reaching maximal values at 2 years. Conversely, no evidence of TrkB protein expression could be found in dendritic cells, epithelial cells or thymocytes. Thymic macrophages in cytospin preparations, as well as in the mouse monocyte macrophage cell lines, also expressed TrkB protein. Although the possible function of TrkB in the thymic macrophage remains to be clarified, present findings add further evidence to the proposed role of neurotrophins in the immune system. Images Figure 1 Figure 2 Figure 3 Figures 4 and 5 PMID:9741346

  17. Electrical and Neurotrophin Enhancement of Neurite Outgrowth within a 3D Collagen Scaffold

    PubMed Central

    Adams, Robert D.; Rendell, Sara R.; Counts, Lauren R.; Papke, Jason B.; Willits, Rebecca K.; Harkins, Amy B.

    2016-01-01

    Electrical and chemical stimulation have been studied as potent mechanisms of enhancing nerve regeneration and wound healing. However, it remains unclear how electrical stimuli affect nerve growth, particularly in the presence of neurotrophic factors. The objective of this study was to explore (1) the effect of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) supplementation to support neurite outgrowth in a 3D scaffold, and (2) the effect of brief, low voltage, electrical stimulation (ES) on neurite outgrowth prior to neurotrophin supplementation. Dissociated E11 chick dorsal root ganglia (DRG) were seeded within a 1.5 mg/mL type-I collagen scaffold. For neurotrophin treatments, scaffolds were incubated for 24 hrs in culture media containing nerve growth factor (NGF, 10 ng/mL) or BDNF (200 ng/mL), or both. For ES groups, scaffolds containing neurons were stimulated for 10 min at 8–10 V/m DC, then incubated for 24 hrs with neurotrophin. Fixed and labeled neurons were imaged to measure neurite growth and directionality. BDNF supplementation was not as effective as NGF at supporting DRG neurite outgrowth. ES prior to NGF supplementation improved DRG neurite outgrowth compared to NGF alone. This combination of brief ES with NGF treatment was the most effective treatment compared to NGF or BDNF alone. Brief ES had no impact on neurite directionality in the 3D scaffolds. These results demonstrate that ES improves neurite outgrowth in the presence of neurotrophins, and could provide a potential therapeutic approach to improve nerve regeneration when coupled with neurotrophin treatment. PMID:24710795

  18. Identification of an evolutionarily conserved domain in human lens epithelium-derived growth factor/transcriptional co-activator p75 (LEDGF/p75) that binds HIV-1 integrase.

    PubMed

    Cherepanov, Peter; Devroe, Eric; Silver, Pamela A; Engelman, Alan

    2004-11-19

    Human lens epithelium-derived growth factor/transcriptional co-activator p75 (LEDGF/p75) protein was recently identified as a binding partner for HIV-1 integrase (IN) in human cells. In this work, we used biochemical and bioinformatic approaches to define the domain organization of LEDGF/p75. Using limited proteolysis and deletion mutagenesis we show that the protein contains a pair of evolutionarily conserved domains, assuming about 35% of its sequence. Whereas the N-terminal PWWP domain had been recognized previously, the second domain is novel. It is comprised of approximately 80 amino acid residues and is both necessary and sufficient for binding to HIV-1 IN. Strikingly, the integrase binding domain (IBD) is not unique to LEDGF/p75, as a second human protein, hepatoma-derived growth factor-related protein 2 (HRP2), contains a homologous sequence. LEDGF/p75 and HRP2 IBDs avidly bound HIV-1 IN in an in vitro GST pull-down assay and each full-length protein potently stimulated HIV-1 IN activity in vitro. LEDGF/p75 and HRP2 are predicted to share a similar domain organization and have an evident evolutionary and likely functional relationship. PMID:15371438

  19. Breast density and parenchymal texture measures as potential risk factors for estrogen-receptor positive breast cancer

    NASA Astrophysics Data System (ADS)

    Keller, Brad M.; Chen, Jinbo; Conant, Emily F.; Kontos, Despina

    2014-03-01

    Accurate assessment of a woman's risk to develop specific subtypes of breast cancer is critical for appropriate utilization of chemopreventative measures, such as with tamoxifen in preventing estrogen-receptor positive breast cancer. In this context, we investigate quantitative measures of breast density and parenchymal texture, measures of glandular tissue content and tissue structure, as risk factors for estrogen-receptor positive (ER+) breast cancer. Mediolateral oblique (MLO) view digital mammograms of the contralateral breast from 106 women with unilateral invasive breast cancer were retrospectively analyzed. Breast density and parenchymal texture were analyzed via fully-automated software. Logistic regression with feature selection and was performed to predict ER+ versus ER- cancer status. A combined model considering all imaging measures extracted was compared to baseline models consisting of density-alone and texture-alone features. Area under the curve (AUC) of the receiver operating characteristic (ROC) and Delong's test were used to compare the models' discriminatory capacity for receptor status. The density-alone model had a discriminatory capacity of 0.62 AUC (p=0.05). The texture-alone model had a higher discriminatory capacity of 0.70 AUC (p=0.001), which was not significantly different compared to the density-alone model (p=0.37). In contrast the combined density-texture logistic regression model had a discriminatory capacity of 0.82 AUC (p<0.001), which was statistically significantly higher than both the density-alone (p<0.001) and texture-alone regression models (p=0.04). The combination of breast density and texture measures may have the potential to identify women specifically at risk for estrogen-receptor positive breast cancer and could be useful in triaging women into appropriate risk-reduction strategies.

  20. Differential Effect of Phosphorylation-Defective Survivin on Radiation Response in Estrogen Receptor-Positive and -Negative Breast Cancer

    PubMed Central

    Li, Li; Larson, Richard; Xu, Wei; Woodward, Wendy A.

    2015-01-01

    Survivin is a key member of the inhibitor of apoptosis protein family, and is considered a promising therapeutic target due to its universal overexpression in cancers. Survivin is implicated in cellular radiation response through its role in apoptosis, cell division, and DNA damage response. In the present study, analysis of publically available data sets showed that survivin gene expression increased with breast cancer stage (p < 0.00001) and was significantly higher in estrogen receptor-negative cancers as compared to estrogen receptor-positive cancers (p = 9e-46). However, survivin was prognostic in estrogen receptor-positive tumors (p = 0.03) but not in estrogen receptor-negative tumors (p = 0.28). We assessed the effect of a survivin dominant-negative mutant on colony-formation (2D) and mammosphere-formation (3D) efficiency, and radiation response in the estrogen receptor-positive MCF7 and estrogen receptor-negative SUM149 breast cancer cell lines. The colony-formation efficiency was significantly lower in the dominant-negative survivin-transduced cells versus control MCF7 cells (0.42 vs. 0.58, p < 0.01), but it was significantly higher in dominant-negative population versus control-transduced SUM149 cells (0.29 vs. 0.20, p < 0.01). A similar, non-significant, trend in mammosphere-formation efficiency was observed. We compared the radiosensitivity of cells stably expressing dominant-negative survivin with their controls in both cell lines under 2D and 3D culture conditions following exposure to increasing doses of radiation. We found that the dominant-negative populations were radioprotective in MCF7 cells but radiosensitive in SUM149 cells compared to the control-transduced population; further, Taxol was synergistic with the survivin mutant in SUM149 but not MCF7. Our data suggests that survivin modulation influences radiation response differently in estrogen receptor-positive and estrogen receptor-negative breast cancer subtypes, warranting further

  1. FLT PET in Measuring Treatment Response in Patients With Newly Diagnosed Estrogen Receptor-Positive, HER2-Negative Stage I-III Breast Cancer

    ClinicalTrials.gov

    2016-06-02

    Estrogen Receptor Positive; HER2/Neu Negative; Male Breast Carcinoma; Stage IA Breast Cancer; Stage IB Breast Cancer; Stage IIA Breast Cancer; Stage IIB Breast Cancer; Stage IIIA Breast Cancer; Stage IIIB Breast Cancer; Stage IIIC Breast Cancer

  2. Tolerability of Therapies Recommended for the Treatment of Hormone Receptor-Positive Locally Advanced or Metastatic Breast Cancer.

    PubMed

    Ohno, Shinji

    2016-08-01

    For women with hormone receptor-positive advanced breast cancer, endocrine therapies, including the selective estrogen receptor modulator tamoxifen, the aromatase inhibitors anastrozole, letrozole, and exemestane, and the selective estrogen receptor degrader fulvestrant, are recommended in clinical guidelines. The addition of targeted agents such as everolimus or palbociclib to aromatase inhibitors are also recommended as treatment options. Chemotherapy remains an option, although clinical guidelines have recommended these agents be reserved for patients with immediately life-threatening disease or if resistance to endocrine therapy is known or suspected. The present review has consolidated the tolerability profiles of the agents approved for use in the treatment of hormone receptor-positive advanced or metastatic breast cancer based on phase III registration trial data. Endocrine therapies are generally well tolerated, although the addition of targeted therapies to aromatase inhibitors or fulvestrant appears to increase the proportion of patients experiencing adverse events, and palbociclib and chemotherapy appear to be more closely associated with serious adverse events, including neutropenia. PMID:27151773

  3. DIESEL PARTICLE INSTILLATION ENHANCES INFLAMMATORY AND NEUROTROPHIN RESPONSES IN THE LUNGS OF ALLERGIC BALB/C MICE

    EPA Science Inventory

    Neurotrophins, including nerve growth factor (NGF) partially mediate many features of allergic airways disease including airways resistance and inflammation. Antibody blockade of NGF attenuates airways resistance associated with the allergen-specific airways responses in mice. ...

  4. State-dependent increase in the levels of neurotrophin-3 and neurotrophin-4/5 in patients with bipolar disorder: A meta-analysis.

    PubMed

    Tseng, Ping-Tao; Chen, Yen-Wen; Tu, Kun-Yu; Wang, Hung-Yu; Chung, Weilun; Wu, Ching-Kuan; Hsu, Shih-Pin; Kuo, Hung-Chang; Lin, Pao-Yen

    2016-08-01

    Bipolar disorder (BD) is one of the most serious psychiatric disorders in the world, but its pathophysiology is still unclear. Regulation of neurotrophic factors have been thought to play a role in this process. There have been inconsistent findings regarding the differences in blood neurotrophin-3 (NT-3) and neurotrophin-4/5 (NT-4/5) between patients with BD and healthy controls (HCs). The aim of the current meta-analysis is to examine the changes in the levels of NT-3 and NT-4/5 in BD patients at different affective states. Eight articles (including 465 BD patients and 353 HCs) were included in the analysis, and their results were pooled by using a random effects model. We found the levels of both NT-3 (p = 0.0046) and NT-4/5 (p = 0.0003) were significantly increased in BD patients, compared to HCs. Through subgroup analysis, this increase persisted only in patients in depressed state (p = 0.0038 for NT-3 and p = 0.0001 for NT-4/5), but not in manic or euthymic state. In addition, we found the differences in NT-3 and NT-4/5 were significantly associated with the duration of illness, but not by the mean age or female proportion. Our results suggest a state-dependent increase in NT-3 and NT-4/5 levels in patients with BD. Further studies are needed to examine dynamic changes of these neurotrophins in BD patients along the disease course. PMID:27214525

  5. Cell-based neurotrophin treatment supports long-term auditory neuron survival in the deaf guinea pig.

    PubMed

    Gillespie, Lisa N; Zanin, Mark P; Shepherd, Robert K

    2015-01-28

    The cochlear implant provides auditory cues to profoundly deaf patients by electrically stimulating the primary auditory neurons (ANs) of the cochlea. However, ANs degenerate in deafness; the preservation of a robust AN target population, in combination with advances in cochlear implant technology, may provide improved hearing outcomes for cochlear implant patients. The exogenous delivery of neurotrophins such as brain-derived neurotrophic factor (BDNF) and neurotrophin-3 is well known to support AN survival in deafness, and cell-based therapies provide a potential clinically viable option for delivering neurotrophins into the deaf cochlea. This study utilized cells that were genetically modified to express BDNF and encapsulated in alginate microspheres, and investigated AN survival in the deaf guinea pig following (a) cell-based neurotrophin treatment in conjunction with chronic electrical stimulation from a cochlear implant, and (b) long-term cell-based neurotrophin delivery. In comparison to deafened controls, there was significantly greater AN survival following the cell-based neurotrophin treatment, and there were ongoing survival effects for at least six months. In addition, functional benefits were observed following cell-based neurotrophin treatment and chronic electrical stimulation, with a statistically significant decrease in electrically evoked auditory brainstem response thresholds observed during the experimental period. This study demonstrates that cell-based therapies, in conjunction with a cochlear implant, shows potential as a clinically transferable means of providing neurotrophin treatment to support AN survival in deafness. This technology also has the potential to deliver other therapeutic agents, and to be used in conjunction with other biomedical devices for the treatment of a variety of neurodegenerative conditions. PMID:25481440

  6. Electroactive biodegradable polyurethane significantly enhanced Schwann cells myelin gene expression and neurotrophin secretion for peripheral nerve tissue engineering.

    PubMed

    Wu, Yaobin; Wang, Ling; Guo, Baolin; Shao, Yongpin; Ma, Peter X

    2016-05-01

    Myelination of Schwann cells (SCs) is critical for the success of peripheral nerve regeneration, and biomaterials that can promote SCs' neurotrophin secretion as scaffolds are beneficial for nerve repair. Here we present a biomaterials-approach, specifically, a highly tunable conductive biodegradable flexible polyurethane by polycondensation of poly(glycerol sebacate) and aniline pentamer, to significantly enhance SCs' myelin gene expression and neurotrophin secretion for peripheral nerve tissue engineering. SCs are cultured on these conductive polymer films, and the biocompatibility of these films and their ability to enhance myelin gene expressions and sustained neurotrophin secretion are successfully demonstrated. The mechanism of SCs' neurotrophin secretion on conductive films is demonstrated by investigating the relationship between intracellular Ca(2+) level and SCs' myelination. Furthermore, the neurite growth and elongation of PC12 cells are induced by adding the neurotrophin medium suspension produced from SCs-laden conductive films. These data suggest that these conductive degradable polyurethanes that enhance SCs' myelin gene expressions and sustained neurotrophin secretion perform great potential for nerve regeneration applications. PMID:26897537

  7. Alternative splicing and caspase-mediated cleavage generate antagonistic variants of the stress oncoprotein LEDGF/p75.

    PubMed

    Brown-Bryan, Terry A; Leoh, Lai S; Ganapathy, Vidya; Pacheco, Fabio J; Mediavilla-Varela, Melanie; Filippova, Maria; Linkhart, Thomas A; Gijsbers, Rik; Debyser, Zeger; Casiano, Carlos A

    2008-08-01

    There is increasing evidence that an augmented state of cellular oxidative stress modulates the expression of stress genes implicated in diseases associated with health disparities such as certain cancers and diabetes. Lens epithelium-derived growth factor p75 (LEDGF/p75), also known as DFS70 autoantigen, is emerging as a survival oncoprotein that promotes resistance to oxidative stress-induced cell death and chemotherapy. We previously showed that LEDGF/p75 is targeted by autoantibodies in prostate cancer patients and is overexpressed in prostate tumors, and that its stress survival activity is abrogated during apoptosis. LEDGF/p75 has a COOH-terminally truncated splice variant, p52, whose role in stress survival and apoptosis has not been thoroughly investigated. We observed unbalanced expression of these proteins in a panel of tumor cell lines, with LEDGF/p75 generally expressed at higher levels. During apoptosis, caspase-3 cleaved p52 to generate a p38 fragment that lacked the NH(2)-terminal PWWP domain and failed to transactivate the Hsp27 promoter in reporter assays. However, p38 retained chromatin association properties and repressed the transactivation potential of LEDGF/p75. Overexpression of p52 or its variants with truncated PWWP domains in several tumor cell lines induced apoptosis, an activity that was linked to the presence of an intron-derived COOH-terminal sequence. These results implicate the PWWP domain of p52 in transcription function but not in chromatin association and proapoptotic activities. Consistent with their unbalanced expression in tumor cells, LEDGF/p75 and p52 seem to play antagonistic roles in the cellular stress response and could serve as targets for novel antitumor therapies. PMID:18708362

  8. Chronic Inflammation and Pain in a TNFR (p55/p75-/-) Dual Deficient Murine Model

    PubMed Central

    Westlund, Karin N.; Zhang, Liping; Ma, Fei; Oz, Helieh S.

    2012-01-01

    Many aspects of tissue damage following acute or chronic inflammatory reactions can be directly attributed to the concomitant biosynthesis and release of inducible early pro-inflammatory cytokine tumor necrosis factor alpha (TNFα). Conversely, systemic inflammation is impacted by consequences of tissue damage. Dysregulated TNFα contributes to numerous pathophysiological conditions including inflammatory bowel disease (IBD) and arthritis. Inflammatory stimuli trigger proteolytic cleavage and shedding of extracellular domains of TNFα receptors giving rise to two soluble fragments (p55 sTNFR1 and p75 sTNFR2) that block further binding, activity and synthesis of TNFα. We hypothesized that absence of sTNFR inhibitory feedback control would result in accumulated high levels of TNFα and other inflammatory factors promoting the cardinal signs of chronic inflammation and pain. The present study reports a translational murine model of chronic arthritis precipitated by two consecutive inflammatory insults. The “double hit” procedures provoke a chronic inflammatory response and pain related behaviors in mice that are dually deficient in p55 (TNFR1) and p75 (TNFR2). The inflammation and pain related behaviors are transient in similarly treated wild type (WT) mice. The complete Freund's adjuvant (CFA) method was used initially to induce knee joint inflammation, tactile mechanical and heat hypersensitivity, and gait disturbance. After these transient effects of the insult were resolved, a recrudescence persisting at least through 23 weeks was promoted by gastrointestinal (GI) insult with dilute intra-colonic mustard oil (MO) only in the mutant mice and was reversed by a P2X7 antagonist. Serum Proteome Profiling analysis revealed high levels of serum inflammatory factors TNFα, RANTES, CXCL9 (MIG), CXCL10 (IP-10), and CCL2 (MCP-1). In conclusion, these data suggest that impaired signaling of TNFα due to deficit of the two protective soluble p55 and p75 sTNFR inhibitory

  9. Functional recovery from sciatic nerve crush injury is delayed because of increased distal atrophy in mice lacking the p75 receptor.

    PubMed

    Chen, Xiaojuan; Zhang, Jianguo; Wang, Xianjun; Bi, Jianzhong

    2016-08-17

    Peripheral nerve injuries are becoming more common, but without effective treatment, the outcome is often very poor. Recent research shows that p75 plays an important role in nerve regeneration, but its mechanisms of action during behavioral recovery and axon regrowth remain unclear. To investigate these mechanisms, we examined recovery from sciatic nerve crush injury in wild-type and p75 knockout mice. We found that sciatic nerve crush injury upregulates mRNA and protein expressions of p75 and p75 deficiency alters gene and protein expression of molecules associated with distal portion atrophy. However, p75 deletion did not alter gene and protein expression in the spinal cord of molecules related to neuronal intrinsic growth capacity. Behavioral testing showed that functional recovery was delayed in mice lacking p75. These results suggest that p75 regulates gene and protein expression that limits the distal atrophy after sciatic nerve injury, thereby regulating axonal growth and functional recovery. PMID:27348017

  10. Role of Neurotrophins in Mediating the Effect of Altered Gravity on the Developing Rat Cerebellum.

    NASA Astrophysics Data System (ADS)

    Sajdel-Sulkowska, Elizabeth

    We previously reported that perinatal exposure to hypergravity resulted in oxidative stress that may contribute to the decrease in Purkinje cell number and the impairment of motor coordination in hypergravity-exposed rat neonates. However, the increase in oxidative stress markers was not uniformly observed in males and females. In the present study we explored the possibility that exposure to hypergravity may result in altered level of neurotrophins, which have been recognized as mediators of both neurodegenerative and neuroprotective mechanisms in the central nervous system. An elevation of neurotrophin-3 (NT-3) has been observed in animal models of hypoxia. To test this hypothesis we compared cerebellar levels of NT-3 between stationary control (SC) and rat neonates exposed perinatally to 1.65 G on a 24-ft centrifuge. The levels of NT-3 were determined by specific ELISA. Preliminary data suggests a 123

  11. Ephrin-A5 Suppresses Neurotrophin Evoked Neuronal Motility, ERK Activation and Gene Expression

    PubMed Central

    Meier, Christin; Anastasiadou, Sofia; Knöll, Bernd

    2011-01-01

    During brain development, growth cones respond to attractive and repulsive axon guidance cues. How growth cones integrate guidance instructions is poorly understood. Here, we demonstrate a link between BDNF (brain derived neurotrophic factor), promoting axonal branching and ephrin-A5, mediating axonal repulsion via Eph receptor tyrosine kinase activation. BDNF enhanced growth cone filopodial dynamics and neurite branching of primary neurons. We show that ephrin-A5 antagonized this BDNF-evoked neuronal motility. BDNF increased ERK phosphorylation (P-ERK) and nuclear ERK entry. Ephrin-A5 suppressed BDNF-induced ERK activity and might sequester P-ERK in the cytoplasm. Neurotrophins are well established stimulators of a neuronal immediate early gene (IEG) response. This is confirmed in this study by e.g. c-fos, Egr1 and Arc upregulation upon BDNF application. This BDNF-evoked IEG response required the transcription factor SRF (serum response factor). Notably, ephrin-A5 suppressed a BDNF-evoked neuronal IEG response, suggesting a role of Eph receptors in modulating gene expression. In opposite to IEGs, long-term ephrin-A5 application induced cytoskeletal gene expression of tropomyosin and actinin. To uncover specific Eph receptors mediating ephrin-As impact on neurotrophin signaling, EphA7 deficient mice were analyzed. In EphA7 deficient neurons alterations in growth cone morphology were observed. However, ephrin-A5 still counteracted neurotrophin signaling suggesting that EphA7 is not required for ephrin and BDNF crosstalk. In sum, our data suggest an interaction of ephrin-As and neurotrophin signaling pathways converging at ERK signaling and nuclear gene activity. As ephrins are involved in development and function of many organs, such modulation of receptor tyrosine kinase signaling and gene expression by Ephs might not be limited to the nervous system. PMID:22022520

  12. Increased expression and activity of p75NTR are crucial events in azacitidine-induced cell death in prostate cancer.

    PubMed

    Gravina, Giovanni Luca; Marampon, Francesco; Sanità, Patrizia; Mancini, Andrea; Colapietro, Alessandro; Scarsella, Luca; Jitariuc, Ana; Biordi, Leda; Ficorella, Corrado; Festuccia, Claudio

    2016-07-01

    The high affinity nerve growth factor (NGF) NGF receptor, p75NTR, is a member of the tumor necrosis factor (TNF) receptor superfamily that shares a conserved intracellular death domain capable of inducing apoptosis and suppressing growth in prostate epithelial cells. Expression of this receptor is lost as prostate cancer progresses and is minimal in established prostate cancer cell lines. We aimed to verify the role of p75NTR in the azacitidine-mediated antitumor effects on 22Rv1 and PC3 androgen-independent prostate cancer cells. In the present study, we reported that the antiproliferative and pro-apoptotic effects of 5-azacytidine (azacitidine) were more marked in the presence of physiological concentrations of NGF and were reduced when a blocking p75NTR antibody or the selective p75NTR inhibitor, Ro 08-2750, were used. Azacitidine increased the expression of p75NTR without interfering with the expression of the low affinity NGF receptor TrkA and induced caspase 9-dependent caspase 3 activity. Taken together, our results suggest that the NGF network could be a candidate for future pharmacological manipulation in aggressive prostate cancer. PMID:27222100

  13. Expression of Nerve Growth Factor (NGF), TrkA, and p75NTR in Developing Human Fetal Teeth

    PubMed Central

    Mitsiadis, Thimios A.; Pagella, Pierfrancesco

    2016-01-01

    Nerve growth factor (NGF) is important for the development and the differentiation of neuronal and non-neuronal cells. NGF binds to specific low- and high-affinity cell surface receptors, respectively, p75NTR and TrkA. In the present study, we examined by immunohistochemistry the expression patterns of the NGF, p75NTR, and TrkA proteins during human fetal tooth development, in order to better understand the mode of NGF signaling action in dental tissues. The results obtained show that these molecules are expressed in a wide range of dental cells of both epithelial and mesenchymal origin during early stages of odontogenesis, as well as in nerve fibers that surround the developing tooth germs. At more advanced developmental stages, NGF and TrkA are localized in differentiated cells with secretory capacities such as preameloblasts/ameloblasts secreting enamel matrix and odontoblasts secreting dentine matrix. In contrast, p75NTR expression is absent from these secretory cells and restricted in proliferating cells of the dental epithelium. The temporospatial distribution of NGF and p75NTR in fetal human teeth is similar, but not identical, with that observed previously in the developing rodent teeth, thus indicating that the genetic information is well-conserved during evolution. The expression patterns of NGF, p75NTR, and TrkA during odontogenesis suggest regulatory roles for NGF signaling in proliferation and differentiation of epithelial and mesenchymal cells, as well as in attraction and sprouting of nerve fibers within dental tissues. PMID:27536251

  14. Neurotrophins are not required for normal embryonic development of olfactory neurons.

    PubMed

    Nef, S; Lush, M E; Shipman, T E; Parada, L F

    2001-06-01

    Neurons of the vertebrate olfactory epithelium (OE) regenerate continuously throughout life. The capacity of these neurons to regenerate and make new and precise synaptic connections in the olfactory bulb provides a useful model to study factors that may control or mediate neuronal regeneration. Expression and in vitro studies have suggested potential roles for the neurotrophins in the olfactory system. To directly examine whether neurotrophins are required for olfactory neuron development, we characterized in vivo the role of the neurotrophins in the primary olfactory system. For this, we generated mutant mice for TrkA, TrkB, TrkC, and also for BDNF and NT3 together with P2-IRES-tau-LacZ trangenic mice. Histochemical staining for beta-galactosidase at birth allowed in vivo analysis of the P2 subpopulation of olfactory neurons as well as their projections to the olfactory bulb. Our data indicate that Trk signaling is not required for normal embryonic development of the olfactory system. PMID:11356021

  15. Interleukin-1 beta and neurotrophin-3 synergistically promote neurite growth in vitro.

    PubMed

    Boato, Francesco; Hechler, Daniel; Rosenberger, Karen; Lüdecke, Doreen; Peters, Eva M; Nitsch, Robert; Hendrix, Sven

    2011-01-01

    Pro-inflammatory cytokines such as interleukin-1 beta (IL-1β) are considered to exert detrimental effects during brain trauma and in neurodegenerative disorders. Consistently, it has been demonstrated that IL-1β suppresses neurotrophin-mediated neuronal cell survival rendering neurons vulnerable to degeneration. Since neurotrophins are also well known to strongly influence axonal plasticity, we investigated here whether IL-1β has a similar negative impact on neurite growth. We analyzed neurite density and length of organotypic brain and spinal cord slice cultures under the influence of the neurotrophins NGF, BDNF, NT-3 and NT-4. In brain slices, only NT-3 significantly promoted neurite density and length. Surprisingly, a similar increase of neurite growth was induced by IL-1β. Additionally, both factors increased the number of brain slices displaying maximal neurite growth. Furthermore, the co-administration of IL-1β and NT-3 significantly increased the number of brain slices displaying maximal neurite growth compared to single treatments. These data indicate that these two factors synergistically stimulate two distinct aspects of neurite outgrowth, namely neurite density and neurite length from acute organotypic brain slices. PMID:22200088

  16. Interleukin-1 beta and neurotrophin-3 synergistically promote neurite growth in vitro

    PubMed Central

    2011-01-01

    Pro-inflammatory cytokines such as interleukin-1 beta (IL-1β) are considered to exert detrimental effects during brain trauma and in neurodegenerative disorders. Consistently, it has been demonstrated that IL-1β suppresses neurotrophin-mediated neuronal cell survival rendering neurons vulnerable to degeneration. Since neurotrophins are also well known to strongly influence axonal plasticity, we investigated here whether IL-1β has a similar negative impact on neurite growth. We analyzed neurite density and length of organotypic brain and spinal cord slice cultures under the influence of the neurotrophins NGF, BDNF, NT-3 and NT-4. In brain slices, only NT-3 significantly promoted neurite density and length. Surprisingly, a similar increase of neurite growth was induced by IL-1β. Additionally, both factors increased the number of brain slices displaying maximal neurite growth. Furthermore, the co-administration of IL-1β and NT-3 significantly increased the number of brain slices displaying maximal neurite growth compared to single treatments. These data indicate that these two factors synergistically stimulate two distinct aspects of neurite outgrowth, namely neurite density and neurite length from acute organotypic brain slices. PMID:22200088

  17. Neurotrophin-3 regulates ribbon synapse density in the cochlea and induces synapse regeneration after acoustic trauma

    PubMed Central

    Wan, Guoqiang; Gómez-Casati, Maria E; Gigliello, Angelica R; Liberman, M Charles; Corfas, Gabriel

    2014-01-01

    Neurotrophin-3 (Ntf3) and brain derived neurotrophic factor (Bdnf) are critical for sensory neuron survival and establishment of neuronal projections to sensory epithelia in the embryonic inner ear, but their postnatal functions remain poorly understood. Using cell-specific inducible gene recombination in mice we found that, in the postnatal inner ear, Bbnf and Ntf3 are required for the formation and maintenance of hair cell ribbon synapses in the vestibular and cochlear epithelia, respectively. We also show that supporting cells in these epithelia are the key endogenous source of the neurotrophins. Using a new hair cell CreERT line with mosaic expression, we also found that Ntf3's effect on cochlear synaptogenesis is highly localized. Moreover, supporting cell-derived Ntf3, but not Bbnf, promoted recovery of cochlear function and ribbon synapse regeneration after acoustic trauma. These results indicate that glial-derived neurotrophins play critical roles in inner ear synapse density and synaptic regeneration after injury. DOI: http://dx.doi.org/10.7554/eLife.03564.001 PMID:25329343

  18. Involvement of Nitric Oxide, Neurotrophins and HPA Axis in Neurobehavioural Alterations Induced by Prenatal Stress.

    PubMed

    Maur, Damian G; Pascuan, Cecilia G; Genaro, Ana M; Zorrilla-Zubilete, Maria A

    2015-01-01

    Several studies suggest that negative emotions during pregnancy generate adverse effects on the cognitive, behavioural and emotional development of the descendants. The psychoneuroendocrine pathways involve the transplacentary passage of maternal glucocorticoids in order to influence directly on fetal growth and brain development.Nitric oxide is a gaseous neurotransmitter that plays an important role in the control of neural activity by diffusing into neurons and participates in learning and memory processes. It has been demonstrated that nitric oxide is involved in the regulation of corticosterone secretion. Thus, it has been found that the neuronal isoform of nitric oxide synthase (nNOS) is an endogenous inhibitor of glucocorticoid receptor (GR) in the hippocampus and that nNOS in the hippocampus may participate in the modulation of hypothalamic-pituitary-adrenal axis activity via GR.Neurotrophins are a family of secreted growth factors consisting of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT3) and NT4. Although initially described in the nervous system, they regulate processes such as cell survival, proliferation and differentiation in several other compartments. It has been demonstrated that the NO-citrulline cycle acts together with BDNF in maintaining the progress of neural differentiation.In the present chapter, we explore the interrelation between nitric oxide, glucocorticoids and neurotrophins in brain areas that are key structures in learning and memory processes. The participation of this interrelation in the behavioural and cognitive alterations induced in the offspring by maternal stress is also addressed. PMID:25287536

  19. Ki67 Heterogeneity in Estrogen Receptor-Positive Breast Cancers: Which Tumor Type Has the Most Heterogeneity?

    PubMed

    Himuro, Takanori; Horimoto, Yoshiya; Arakawa, Atsushi; Tanabe, Masahiko; Saito, Mitsue

    2016-04-01

    Heterogeneity of Ki67 expression, often seen in breast cancer, can make evaluation of the expression of this marker difficult and give rise to confusion when considering adjuvant treatments for patients. Herein, we investigated estrogen receptor-positive breast cancers to reveal the tumor characteristics associated with Ki67 heterogeneity. Surgical specimens from 85 invasive ductal carcinomas of no special type and 13 invasive lobular carcinomas were examined. We first calculated the differences between Ki67 expression in a hot spot and those in 4 random fields on the same slide. We then evaluated Ki67 heterogeneity within the tumor, based on these differences. Among clinicopathological factors, solid-tubular carcinoma, an architectural growth pattern subtype of invasive ductal carcinoma, correlated with high Ki67 heterogeneity (P < .05). Our results indicate that we might need to be aware of histological patterns when selecting appropriate microscopic fields for evaluating Ki67 expression. PMID:26353854

  20. Establishment and characterization of a new human oestradiol- and progesterone-receptor-positive mammary carcinoma serially transplantable in nude mice.

    PubMed

    Naundorf, H; Fichtner, I; Büttner, B; Frege, J

    1992-01-01

    A human mammary carcinoma originating from a postmenopausal patient was successfully transplanted into nude mice. According to the adopted criteria the tumour proved to be oestradiol- and progesterone-receptor-positive. Histological studies of the patient tumour revealed a ductal invasive mammary carcinoma with 80% tubular growth pattern. Following transplantation the adenoid structures decreased to 30%; the mitosis rate and grade of malignancy increased. Treatment of the nude mice with 20 micrograms oestradiol benzoate/mouse caused a loss of the oestradiol receptor of the mammary carcinoma. The mammary carcinoma 3366 can be used for testing of antineoplastic substances, antihormones and for studies in regard to down-regulation or blocking of hormone receptors and possible consequences for therapies. PMID:1400563

  1. Evaluating the Survival Benefit Following Ovarian Function Suppression in Premenopausal Patients with Hormone Receptor Positive Early Breast Cancer

    PubMed Central

    Qiu, Lin; Fu, Fangmeng; Huang, Meng; Lin, Yuxiang; chen, Yazhen; Chen, Minyan; Wang, Chuan

    2016-01-01

    There are divergent opinions regarding the use of ovarian function suppression or ablation (hereafter, OFS) in hormone receptor positive early breast cancer patients. In order to clarify the survival benefit of OFS, a meta-analysis was performed. The result is that use of OFS was more effective than no OFS on DFS (the pooled relative risk (pRR) = 0.86; 95% CI: 0.75–0.96) and on OS (pRR = 0.79; 95% CI: 0.70–0.89). In subgroup analysis, we found that increased DFS was positively associated with patients who had received chemotherapy (pRR = 0.85; 95% CI: 0.74–0.96), who were lymph node negative (pRR = 0.74; 95% CI: 0.61–0.91) and were less than 40 years old (pRR = 0.71; 95% CI: 0.59–0.83). There was a significant difference in OS between the groups receiving chemotherapy (pRR = 0.73; 95% CI: 0.58–0.89) or for patients less than 40 years old (pRR = 0.52; 95% CI: 0.18–0.87). The use of OFS also produces statistical differences in the occurrence of the side-effects; severe hot flashes (pRR = 2.32; 95% CI: 1.36–3.97), and hypertension (pRR = 1.54; 95% CI: 1.12–2.12). In general, OFS should be considered as one treatment for hormone receptor positive premenopausal early breast cancer patients who have received chemotherapy and are less than 40 years old. We also should pay attention to the side-effects and weigh the advantages and disadvantages before deciding on using OFS. PMID:27230285

  2. Evaluating the Survival Benefit Following Ovarian Function Suppression in Premenopausal Patients with Hormone Receptor Positive Early Breast Cancer.

    PubMed

    Qiu, Lin; Fu, Fangmeng; Huang, Meng; Lin, Yuxiang; Chen, Yazhen; Chen, Minyan; Wang, Chuan

    2016-01-01

    There are divergent opinions regarding the use of ovarian function suppression or ablation (hereafter, OFS) in hormone receptor positive early breast cancer patients. In order to clarify the survival benefit of OFS, a meta-analysis was performed. The result is that use of OFS was more effective than no OFS on DFS (the pooled relative risk (pRR) = 0.86; 95% CI: 0.75-0.96) and on OS (pRR = 0.79; 95% CI: 0.70-0.89). In subgroup analysis, we found that increased DFS was positively associated with patients who had received chemotherapy (pRR = 0.85; 95% CI: 0.74-0.96), who were lymph node negative (pRR = 0.74; 95% CI: 0.61-0.91) and were less than 40 years old (pRR = 0.71; 95% CI: 0.59-0.83). There was a significant difference in OS between the groups receiving chemotherapy (pRR = 0.73; 95% CI: 0.58-0.89) or for patients less than 40 years old (pRR = 0.52; 95% CI: 0.18-0.87). The use of OFS also produces statistical differences in the occurrence of the side-effects; severe hot flashes (pRR = 2.32; 95% CI: 1.36-3.97), and hypertension (pRR = 1.54; 95% CI: 1.12-2.12). In general, OFS should be considered as one treatment for hormone receptor positive premenopausal early breast cancer patients who have received chemotherapy and are less than 40 years old. We also should pay attention to the side-effects and weigh the advantages and disadvantages before deciding on using OFS. PMID:27230285

  3. Differential Phosphorylation of Smad1 Integrates BMP and Neurotrophin Pathways through Erk/Dusp in Axon Development

    PubMed Central

    Finelli, Mattéa J.; Murphy, Kevin J.; Chen, Lei; Zou, Hongyan

    2013-01-01

    SUMMARY Sensory axon development requires concerted actions of growth factors for the precise control of axonal outgrowth and target innervation. How developing sensory neurons integrate different cues is poorly understood. We demonstrate here that Smad1 activation is required for neurotrophin-mediated sensory axon growth in vitro and in vivo. Through differential phosphorylation, Smad1 exerts transcriptional selectivity to regulate the expression and activity of Erk1 and Erk2—two key neurotrophin effectors. Specifically, BMPs signal through carboxy-terminal phosphorylation of Smad1 (pSmad1C) to induce Erk1/2 transcription for enhanced neurotrophin responsiveness. Meanwhile, neurotrophin signaling results in linker phosphorylation of Smad1 (pSmad1L), which in turn upregulates an Erk-specific dual-specificity phosphatase, Dusp6, leading to reduced pErk1/2, and constituting a negative feedback loop to prevent axon overgrowth. Together, BMP and neurotrophin pathways are integrated in a tightly regulated signaling network with balanced ratio of Erk1/2 and pErk1/2 to direct the precise connections between sensory neurons and peripheral targets. PMID:23665221

  4. Dynamics of the Ternary Complex Formed by c-Myc Interactor JPO2, Transcriptional Co-activator LEDGF/p75, and Chromatin*

    PubMed Central

    Hendrix, Jelle; van Heertum, Bart; Vanstreels, Els; Daelemans, Dirk; De Rijck, Jan

    2014-01-01

    Lens epithelium-derived growth factor (LEDGF/p75) is a transcriptional co-activator involved in targeting human immunodeficiency virus (HIV) integration and the development of MLL fusion-mediated acute leukemia. A previous study revealed that LEDGF/p75 dynamically scans the chromatin, and upon interaction with HIV-1 integrase, their complex is locked on chromatin. At present, it is not known whether LEDGF/p75-mediated chromatin locking is typical for interacting proteins. Here, we employed continuous photobleaching and fluorescence correlation and cross-correlation spectroscopy to investigate in vivo chromatin binding of JPO2, a LEDGF/p75- and c-Myc-interacting protein involved in transcriptional regulation. In the absence of LEDGF/p75, JPO2 performs chromatin scanning inherent to transcription factors. However, whereas the dynamics of JPO2 chromatin binding are decelerated upon interaction with LEDGF/p75, very strong locking of their complex onto chromatin is absent. Similar results were obtained with the domesticated transposase PogZ, another cellular interaction partner of LEDGF/p75. We furthermore show that diffusive JPO2 can oligomerize; that JPO2 and LEDGF/p75 interact directly and specifically in vivo through the specific interaction domain of JPO2 and the C-terminal domain of LEDGF/p75, comprising the integrase-binding domain; and that modulation of JPO2 dynamics requires a functional PWWP domain in LEDGF/p75. Our results suggest that the dynamics of the LEDGF/p75-chromatin interaction depend on the specific partner and that strong chromatin locking is not a property of all LEDGF/p75-binding proteins. PMID:24634210

  5. Structural Basis for the Recognition Between HIV-1 Integrase and Transcriptional Coactivator p75

    SciTech Connect

    Cherepanov,P.; Ambrosio, A.; Rahman, S.; Ellenberger, T.; Engelman, A.

    2005-01-01

    Integrase (IN) is an essential retroviral enzyme, and human transcriptional coactivator p75, which is also referred to as lens epithelium-derived growth factor (LEDGF), is the dominant cellular binding partner of HIV-1 IN. Here, we report the crystal structure of the dimeric catalytic core domain of HIV-1 IN complexed to the IN-binding domain of LEDGF. Previously identified LEDGF hotspot residues anchor the protein to both monomers at the IN dimer interface. The principal structural features of IN that are recognized by the host factor are the backbone conformation of residues 168-171 from one monomer and a hydrophobic patch that is primarily comprised of {alpha}-helices 1 and 3 of the second IN monomer. Inspection of diverse retroviral primary and secondary sequence elements helps to explain the apparent lentiviral tropism of the LEDGF-IN interaction. Because the lethal phenotypes of HIV-1 mutant viruses unable to interact with LEDGF indicate that IN function is highly sensitive to perturbations of the structure around the LEDGF-binding site, we propose that small molecule inhibitors of the protein-protein interaction might similarly disrupt HIV-1 replication.

  6. Tumor necrosis factor in traumatic brain injury: effects of genetic deletion of p55 or p75 receptor

    PubMed Central

    Longhi, Luca; Perego, Carlo; Ortolano, Fabrizio; Aresi, Silvia; Fumagalli, Stefano; Zanier, Elisa R; Stocchetti, Nino; De Simoni, Maria-Grazia

    2013-01-01

    The role of tumor necrosis factor (TNF) and its receptors after traumatic brain injury (TBI) remains unclear. We evaluated the effects of genetic deletion of either p55 or p75 TNF receptor on neurobehavioral outcome, histopathology, DNA damage and apoptosis-related cell death/survival gene expression (bcl-2/bax), and microglia/macrophage (M/M) activation in wild-type (WT) and knockout mice after TBI. Injured p55 (−/−) mice showed a significant attenuation while p75 (−/−) mice showed a significant worsening of sensorimotor deficits compared with WT mice over 4 weeks postinjury. At the same time point, contusion volume in p55 (−/−) mice (11.1±3.3 mm3) was significantly reduced compared with WT (19.7±3.4 mm3) and p75 (−/−) mice (20.9±3.2 mm3). At 4 hours postinjury, bcl-2/bax ratio mRNA expression was increased in p55 (−/−) compared with p75 (−/−) mice and was associated with reduced DNA damage terminal deoxynucleotidyl transferaseYmediated dUTP nick end labeling (TUNEL-positivity), reduced CD11b expression and increased Ym1 expression at 24 hours postinjury in p55 (−/−) compared with p75 (−/−) mice, indicative of a protective M/M response. These data suggest that TNF may exacerbate neurobehavioral deficits and tissue damage via p55 TNF receptor whose inhibition may represent a specific therapeutic target after TBI. PMID:23611870

  7. p75NTR is highly expressed in vestibular schwannomas and promotes cell survival by activating NF-κB

    PubMed Central

    Ahmad, Iram; Yue, Wei Ying; Fernando, Augusta; Clark, J. Jason; Woodson, Erika A.; Hansen, Marlan R.

    2014-01-01

    Vestibular schwannomas (VSs) arise from Schwann cells (SCs) and result from the loss of function of merlin, the protein product of the NF2 tumor suppressor gene. In contrast to non-neoplastic SCs, VS cells survive long-term in the absence of axons. We find that p75NTR is over-expressed in VSs compared with normal nerves, both at the transcript and protein level, similar to the response of non-neoplastic SCs following axotomy. Despite elevated p75NTR expression, VS cells are resistant to apoptosis due to treatment with pro-NGF, a high affinity ligand for p75NTR. Furthermore, treatment with proNGF protects VS cells from apoptosis due to c-Jun N-terminal kinase (JNK) inhibition indicating that p75NTR promotes VS cell survival. Treatment of VS cells with proNGF activated NF-κB while inhibition of JNK with SP600125 or siRNA-mediated knockdown reduced NF-κB activity. Significantly, proNGF also activated NF-κB in cultures treated with JNK inhibitors. Thus, JNK activity appears to be required for basal levels of NF-κB activity, but not for proNGF-induced NF-κB activity. To confirm that the increase in NF-κB activity contributes to the prosurvival effect of proNGF, we infected VS cultures with Ad.IκB.SerS32/36A virus, which inhibits NF-κB activation. Compared to control virus, Ad.IκB.SerS32/36A significantly increased apoptosis including in VS cells treated with proNGF. Thus, in contrast to non-neoplastic SCs, p75NTR signaling provides a prosurvival response in VS cells by activating NF-κB independent of JNK. Such differences may contribute to the ability of VS cells to survive long-term in the absence of axons. PMID:24976126

  8. Characterization of a tissue-specific CDP/Cux isoform, p75, activated in breast tumor cells.

    PubMed

    Goulet, Brigitte; Watson, Peter; Poirier, Madeleine; Leduy, Lam; Bérubé, Ginette; Meterissian, Sarkis; Jolicoeur, Paul; Nepveu, Alain

    2002-11-15

    Two isoforms of the CCAAT-displacement protein/cut homeobox (CDP/Cux) transcription factor have been characterized thus far. The full length protein, p200, which contains four DNA binding domains, transiently binds to DNA and carries the CCAAT-displacement activity. The p110 isoform is generated by proteolytic processing at the G1-S transition and is capable of stable interaction with DNA. Here we demonstrate the existence of a shorter CDP/Cux isoform, p75, which contains only two DNA binding domains, Cut repeat 3 and the Cut homeodomain, and binds more stably to DNA. CDP/Cux p75 was able to repress a reporter carrying the promoter for the cyclin-dependent kinase inhibitor p21 gene and to activate a DNA polymerase alpha gene reporter. Expression of CDP/Cux p75 involved a novel mechanism: transcription initiation within intron 20. The intron 20-initiated mRNA (I20-mRNA) was expressed at higher level in the thymus and in CD4+/CD8+ and CD4+ T cells. I20-mRNA was expressed only weakly or not at all in normal human mammary epithelial cells and normal breast tissues but was detected in many breast tumor cells lines and breast tumors. In invasive tumors a significant association was established between higher I20-mRNA expression and a diffuse infiltrative growth pattern (n = 41, P = 0.0137). In agreement with these findings, T47D breast cancer cells stably expressing p75 could not form tubule structures in collagen but rather developed as solid undifferentiated aggregates of cells. Taken together, these results suggest that aberrant expression of the CDP/Cux p75 isoform in mammary epithelial cells may be associated with the process of tumorigenesis in breast cancer. PMID:12438259

  9. From Molecular to Nanotechnology Strategies for Delivery of Neurotrophins: Emphasis on Brain-Derived Neurotrophic Factor (BDNF)

    PubMed Central

    Géral, Claire; Angelova, Angelina; Lesieur, Sylviane

    2013-01-01

    Neurodegenerative diseases represent a major public health problem, but beneficial clinical treatment with neurotrophic factors has not been established yet. The therapeutic use of neurotrophins has been restrained by their instability and rapid degradation in biological medium. A variety of strategies has been proposed for the administration of these leading therapeutic candidates, which are essential for the development, survival and function of human neurons. In this review, we describe the existing approaches for delivery of brain-derived neurotrophic factor (BDNF), which is the most abundant neurotrophin in the mammalian central nervous system (CNS). Biomimetic peptides of BDNF have emerged as a promising therapy against neurodegenerative disorders. Polymer-based carriers have provided sustained neurotrophin delivery, whereas lipid-based particles have contributed also to potentiation of the BDNF action. Nanotechnology offers new possibilities for the design of vehicles for neuroprotection and neuroregeneration. Recent developments in nanoscale carriers for encapsulation and transport of BDNF are highlighted. PMID:24300402

  10. Network-based approach to identify prognostic biomarkers for estrogen receptor-positive breast cancer treatment with tamoxifen.

    PubMed

    Liu, Rong; Guo, Cheng-Xian; Zhou, Hong-Hao

    2015-01-01

    This study aims to identify effective gene networks and prognostic biomarkers associated with estrogen receptor positive (ER+) breast cancer using human mRNA studies. Weighted gene coexpression network analysis was performed with a complex ER+ breast cancer transcriptome to investigate the function of networks and key genes in the prognosis of breast cancer. We found a significant correlation of an expression module with distant metastasis-free survival (HR = 2.25; 95% CI .21.03-4.88 in discovery set; HR = 1.78; 95% CI = 1.07-2.93 in validation set). This module contained genes enriched in the biological process of the M phase. From this module, we further identified and validated 5 hub genes (CDK1, DLGAP5, MELK, NUSAP1, and RRM2), the expression levels of which were strongly associated with poor survival. Highly expressed MELK indicated poor survival in luminal A and luminal B breast cancer molecular subtypes. This gene was also found to be associated with tamoxifen resistance. Results indicated that a network-based approach may facilitate the discovery of biomarkers for the prognosis of ER+ breast cancer and may also be used as a basis for establishing personalized therapies. Nevertheless, before the application of this approach in clinical settings, in vivo and in vitro experiments and multi-center randomized controlled clinical trials are still needed. PMID:25756514

  11. In vivo use of a radioiodinated somatostatin analogue: dynamics, metabolism, and binding to somatostatin receptor-positive tumors in man

    SciTech Connect

    Bakker, W.H.; Krenning, E.P.; Breeman, W.A.; Kooij, P.P.; Reubi, J.C.; Koper, J.W.; de Jong, M.; Lameris, J.S.; Visser, T.J.; Lamberts, S.W. )

    1991-06-01

    Somatostatin analogues, labeled with gamma-emitting radionuclides, are of potential value in the localization of somatostatin receptor-positive tumors with gamma camera imaging. We investigated the application in man of a radioiodinated analogue of somatostatin, 123I-Tyr-3-octreotide, which has similar biologic characteristics as the native peptide. The radiopharmaceutical is cleared rapidly from the circulation (up to 85% of the dose after 10 min) mainly by the liver. Liver radioactivity is rapidly excreted into the biliary system. Until 3 hr after injection, radioactivity in the circulation is mainly in the form of 123I-Tyr-3-octreotide. Thereafter, plasma samples contain increasing proportions of free iodide. Similarly, during the first hours after injection, radioactivity in the urine exists mainly in the form of the unchanged peptide. Thereafter, a progressive increase in radioiodide excretion is observed, indicating degradation of the radiopharmaceutical in vivo. Fecal excretion of radioactivity amounts to only a few percent of the dose. The calculated median effective dose equivalent is comparable with values for applications of other 123I-radiopharmaceuticals (0.019 mSv/MBq).

  12. Effects of alpha-7 nicotinic acetylcholine receptor positive allosteric modulator on lipopolysaccharide-induced neuroinflammatory pain in mice.

    PubMed

    Abbas, Muzaffar; Rahman, Shafiqur

    2016-07-15

    Evidence indicates that microglial activation contributes to the pathophysiology and maintenance of neuroinflammatory pain involving central nervous system alpha-7 nicotinic acetylcholine receptors. The objective of the present study was to determine the effects of 3a,4,5,9b-Tetrahydro-4-(1-naphthalenyl)-3H-cyclopentan[c]quinoline-8-sulfonamide (TQS), an alpha-7 nicotinic acetylcholine receptor positive allosteric modulator (PAM), on tactile allodynia and thermal hyperalgesia following lipopolysaccharide (LPS)-induced microglial activation in hippocampus, a neuroinflammatory pain model in mice. In addition, we examined the effects of TQS on microglial activation marker, an ionized calcium-binding adapter molecule 1 (Iba-1), in the hippocampus may be associated with neuroinflammatory pain. Pretreatment of TQS (4mg/kg) significantly reduced LPS (1mg/kg)-induced tactile allodynia and thermal hyperalgesia. Moreover, pretreatment of methyllycaconitine (3mg/kg) significantly reversed TQS-induced antiallodynic and antihyperalgesic responses indicating the involvement of alpha-7 nicotinic acetylcholine receptor. Pretreatment of TQS significantly decreased LPS-induced increased in hippocampal Iba-1 expression. Overall, these results suggest that TQS reduces LPS-induced neuroinflammatory pain like symptoms via modulating microglial activation likely in the hippocampus and/or other brain region by targeting alpha-7 nicotinic acetylcholine receptor. Therefore, alpha-7 nicotinic acetylcholine receptor PAM such as TQS could be a potential drug candidate for the treatment of neuroinflammatory pain. PMID:27154173

  13. Recurrent ESR1-CCDC170 rearrangements in an aggressive subset of estrogen-receptor positive breast cancers

    PubMed Central

    Veeraraghavan, Jamunarani; Tan, Ying; Cao, Xi-Xi; Kim, Jin-Ah; Wang, Xian; Chamness, Gary C.; Maiti, Sourindra N.; Cooper, Laurence J. N.; Edwards, Dean P.; Contreras, Alejandro; Hilsenbeck, Susan G.; Chang, Eric C.; Schiff, Rachel; Wang, Xiao-Song

    2014-01-01

    Characterizing the genetic alterations leading to the more aggressive forms of estrogen receptor positive (ER+) breast cancers are of critical significance in breast cancer management. Here we identify recurrent rearrangements between estrogen receptor gene ESR1 and its neighbor CCDC170, which are enriched in the more aggressive and endocrine-resistant luminal-B tumors, through large-scale analyses of breast cancer transcriptome and copy number alterations. Further screening of 200 ER+ breast cancers identifies eight ESR1-CCDC170 positive tumors. These fusions encode N-terminally truncated CCDC170 proteins (ΔCCDC170). When introduced into ER+ breast cancer cells, ΔCCDC170 leads to markedly increased cell motility and anchorage-independent growth, reduced endocrine sensitivity, and enhanced xenograft tumor formation. Mechanistic studies suggest that ΔCCDC170 engages Gab1 signalosome to potentiate growth factor signaling and enhance cell motility. Together, this study identifies neoplastic ESR1-CCDC170 fusions in a more aggressive subset of ER+ breast cancer, which suggests a new concept of ER pathobiology in breast cancer. PMID:25099679

  14. Neurotrophin-dependent plasticity of neurotransmitter segregation in the rat superior cervical ganglion in vivo.

    PubMed

    Vega, A; Cancino-Rodezno, A; Valle-Leija, P; Sánchez-Tafolla, B M; Elinos, D; Cifuentes, F; Morales, M A

    2016-08-01

    Neurons are able to segregate transmitters to different axon endings. Segregation is a plastic neuronal feature; it can be modulated by synaptic environment. We have demonstrated that neurotrophin and other cellular factors regulate segregation in sympathetic neurons in culture. Herein we tested the hypothesis that sympathetic neurons in vivo are also capable to exhibit neurotrophin-dependent plasticity of segregation. To explore the effect of neurotrophin on segregation, we reduced ganglionic NGF content by the transection of postganglionic nerves (axotomy) of the superior cervical ganglia. By immunohistochemistry, Western blot, and PCR analyses, we explored the effect of axotomy on the NGF and BDNF content of ganglionic neurons, and on the segregation extent of vesicular acetylcholine transporter (VAChT) and methionine enkephalin (mENK) in pre-ganglionic varicosities. We analyzed NGF-dependence of the changes found by applying exogenous NGF. Axotomy reduced ganglionic NGF and BDNF content, increased NGF transcripts, and increased VAChT-mENK segregation. Axotomy also increased the number of VAChT immunopositive varicosities, and caused the appearance of a population of VAChT-, mENK- or SV2-containing varicosities lacking Synaptophysin (Syn). Administration of NGF prevented changes in NGF content, kept NGF transcripts increased, and counteracted changes in segregation and in the number of cholinergic varicosities. The exogenous NGF did not preclude change in BDNF content or in the occurrence of the VAChT- or mENK-containing varicosities lacking Syn. Data demonstrate that segregation of transmitters in vivo is plastic and it is modulated by environmental signals like NGF. We propose a possible functional correlate of segregation plasticity in the sympathetic ganglia. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 832-846, 2016. PMID:26562219

  15. Temporary Neurotrophin Treatment Prevents Deafness-Induced Auditory Nerve Degeneration and Preserves Function.

    PubMed

    Ramekers, Dyan; Versnel, Huib; Strahl, Stefan B; Klis, Sjaak F L; Grolman, Wilko

    2015-09-01

    After substantial loss of cochlear hair cells, exogenous neurotrophins prevent degeneration of the auditory nerve. Because cochlear implantation, the current therapy for profound sensorineural hearing loss, depends on a functional nerve, application of neurotrophins is being investigated. We addressed two questions important for fundamental insight into the effects of exogenous neurotrophins on a degenerating neural system, and for translation to the clinic. First, does temporary treatment with brain-derived neurotrophic factor (BDNF) prevent nerve degeneration on the long term? Second, how does a BDNF-treated nerve respond to electrical stimulation? Deafened guinea pigs received a cochlear implant, and their cochleas were infused with BDNF for 4 weeks. Up to 8 weeks after treatment, their cochleas were analyzed histologically. Electrically evoked compound action potentials (eCAPs) were recorded using stimulation paradigms that are informative of neural survival. Spiral ganglion cell (SGC) degeneration was prevented during BDNF treatment, resulting in 1.9 times more SGCs than in deafened untreated cochleas. Importantly, SGC survival was almost complete 8 weeks after treatment cessation, when 2.6 times more SGCs were observed. In four eCAP characteristics (three involving alteration of the interphase gap of the biphasic current pulse and one involving pulse trains), we found large and statistically significant differences between normal-hearing and deaf controls. Importantly, for BDNF-treated animals, these eCAP characteristics were near normal, suggesting healthy responsiveness of BDNF-treated SGCs. In conclusion, clinically practicable short-term neurotrophin treatment is sufficient for long-term survival of SGCs, and it can restore or preserve SGC function well beyond the treatment period. Significance statement: Successful restoration of hearing in deaf subjects by means of a cochlear implant requires a healthy spiral ganglion cell population. Deafness

  16. STANDARDIZATION AND VALIDATION OF ADENOVIRAL TRANSDUCTION OF AN ANDROGEN RECEPTOR POSITIVE CELL LINE WITH AN MMTV-LUC REPORTER FOR ENDOCRINE SCREENING

    EPA Science Inventory

    Standardization and Validation of Adenoviral Transduction of an Androgen Receptor Positive Cell Line with an MMTV-Luc Reporter for Endocrine Screening P. Hartig, K . Bobseine,
    M. Cardon, C. Lambright and L. E. Gray, Jr. USEPA, Reproductive Toxicology Division, NHEERL, RTP, NC...

  17. THE ROLE OF TNF-α RECEPTORS p55 AND p75 IN ACUTE MYOCARDIAL ISCHEMIA/REPERFUSION INJURY AND LATE PRECONDITIONING

    PubMed Central

    Flaherty, Michael P.; Guo, Yiru; Tiwari, Sumit; Rezazadeh, Arash; Hunt, Greg; Sanganalmath, Santosh K.; Tang, Xian-Liang; Bolli, Roberto; Dawn, Buddhadeb

    2008-01-01

    The specific role of TNF-α receptor I (TNFR-I, p55) and II (TNFR-II, p75) in myocardial ischemic injury remains unclear. Using genetically engineered mice, we examined the relative effects of TNF-α signaling via p55 and p75 in acute myocardial ischemia/reperfusion injury under basal conditions and in late preconditioning (PC). Wild-type (WT) (C57BL/6 and B6,129) mice and mice lacking TNF-α (TNF-α−/−), p55 (p55−/−), p75 (p75−/−), or both receptors (p55−/−/p75−/−) underwent 30 min of coronary occlusion and 24 h of reperfusion with or without six cycles of 4-min coronary occlusion/4-min reperfusion (O/R) 24 h earlier (ischemic PC). Six cycles of O/R reduced infarct size 24 h later in WT mice, indicating a late PC effect. This late PC-induced infarct-sparing effect was abolished not only in TNF-α−/− and p55−/−/p75−/− mice, but also in p55−/− and p75−/− mice, indicating that TNF-α signaling via both p55 and p75 is necessary for the development of protection. In nonpreconditioned TNF-α−/−, p55−/−/p75−/−, and p75−/− mice, infarct size was similar to strain-matched WT mice. In contrast, infarct size in nonpreconditioned p55−/− mice was reduced compared with nonpreconditioned WT mice. We conclude that (i) unopposed p75 signaling (in the absence of p55) reduces infarct size following acute ischemia/reperfusion injury in naïve myocardium, whereas unopposed p55 signaling (in the absence of p75) has no effect; and (ii) the development of the infarct-sparing effects of the late phase of PC requires nonredundant signaling via both p55 and p75 receptors. These findings reveal a fundamental, heretofore unrecognized, difference between the two TNF-α receptors in the setting of myocardial ischemia/reperfusion injury: that is, both p55 and p75 are necessary for the development of protection during late PC, but only signaling via p75 is protective in nonpreconditioned myocardium. PMID:18824172

  18. p75NTR enhances PC12 cell tumor growth by a non-receptor mechanism involving downregulation of cyclin D2

    SciTech Connect

    Fritz, Melinda D.; Mirnics, Zeljka K.; Nylander, Karen D.; Schor, Nina F. . E-mail: nfschor@pitt.edu

    2006-10-15

    p75NTR is a member of the tumor necrosis superfamily of proteins which is variably associated with induction of apoptosis and proliferation. Cyclin D2 is one of the mediators of cellular progression through G1 phase of the cell cycle. The present study demonstrates the inverse relationship between expression of cyclin D2 and expression of p75NTR in PC12 cells. Induction of p75NTR expression in p75NTR-negative PC12 cells results in downregulation of cyclin D2; suppression of p75NTR expression with siRNA in native PC12 cells results in upregulation of cyclin D2. The effects of p75NTR on cyclin D2 expression are mimicked in p75NTR-negative cells by transfection with the intracellular domain of p75NTR. Cyclin-D2-positive PC12 cell cultures grow more slowly than cyclin-D2-negative cultures, and induction of expression of cyclin D2 slows the culture growth rate of cyclin-D2-negative cells. Finally, subcutaneous murine xenografts of cyclin-D2-negative, p75NTR-positive PC12 cells more frequently and more rapidly produce tumors than the analogous xenografts of cyclin-D2-positive, p75NTR-negative cells. These results suggest that p75NTR suppresses cyclin D2 expression in PC12 cells by a mechanism distinct from its function as a nerve growth factor receptor and that cyclin D2 expression decreases cell culture and xenografted tumor growth.

  19. Discriminative Stimulus Effects of the GABAB Receptor-Positive Modulator rac-BHFF: Comparison with GABAB Receptor Agonists and Drugs of Abuse

    PubMed Central

    Cheng, Kejun; Rice, Kenner C.

    2013-01-01

    GABAB receptor-positive modulators are thought to have advantages as potential medications for anxiety, depression, and drug addiction. They may have fewer side effects than GABAB receptor agonists, because selective enhancement of activated receptors could have effects different from nonselective activation of all receptors. To examine this, pigeons were trained to discriminate the GABAB receptor-positive modulator (R,S)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3H-benzofuran-2-one (rac-BHFF) from its vehicle. The discriminative stimulus effects of rac-BHFF were not mimicked by the GABAB receptor agonists baclofen and γ-hydroxybutyrate (GHB), not by diazepam, and not by alcohol, cocaine, and nicotine, whose self-administration has been reported to be attenuated by GABAB receptor-positive modulators. The discriminative stimulus effects of rac-BHFF were not antagonized by the GABAB receptor antagonist 3-aminopropyl (diethoxymethyl)phosphinic acid (CGP35348) but were attenuated by the less efficacious GABAB receptor-positive modulator 2,6-di-tert-butyl-4-(3-hydroxy-2,2-dimethylpropyl)phenol (CGP7930), suggesting the possibility that rac-BHFF produces its discriminative stimulus effects by directly activating GABAB2 subunits of GABAB receptors. At a dose 10-fold lower than the training dose, rac-BHFF enhanced the discriminative stimulus effects of baclofen, but not of GHB. This study provides evidence that the effects of GABAB receptor-positive modulators are not identical to those of GABAB receptor agonists. In addition, the results suggest that positive modulation of GABAB receptors does not produce discriminative stimulus effects similar to those of benzodiazepines, alcohol, cocaine, and nicotine. Finally, the finding that rac-BHFF enhanced effects of baclofen but not of GHB is consistent with converging evidence that the populations of GABAB receptors mediating the effects of baclofen and GHB are not identical. PMID:23275067

  20. Tumor necrosis factor receptor p75 mediates cell-specific activation of nuclear factor kappa B and induction of human cytomegalovirus enhancer.

    PubMed

    Laegreid, A; Medvedev, A; Nonstad, U; Bombara, M P; Ranges, G; Sundan, A; Espevik, T

    1994-03-11

    The functional role of human tumor necrosis factor receptor (TNFR) p75 was studied by the use of TNFR p75-specific agonistic antibodies. Human SW480T adenocarcinoma cells, stably transfected with a reporter construct containing beta-galactosidase under the control of human cytomegalovirus immediate early enhancer, were stimulated with anti-TNFR p75 polyclonal antiserum or monoclonal antibodies followed by measurement of beta-galactosidase activity and analysis by electrophoretic mobility shift assays. It was found that cross-linking of TNFR p75 led to strong induction of the human cytomegalovirus enhancer as well as activation of nuclear factor-kappa B (NF-kappa B). Stimulation of TNFR p75 also mediated activation of NF-kappa B in human KYM-1 rhabdomyosarcoma cells but not in other cell types such as U937 and HL-60 monocytic cells or in Eahy 926 endothelial cells. NF-kappa B activation induced by TNFR p75 was delayed approximately 15 min compared with NF-kappa B activation induced by TNFR p55, indicating that the two TNFRs activate NF-kappa B through different signaling pathways. The data presented in this study identify intracellular responses mediated by TNFR p75 which have not been reported previously and suggest that TNFR p75-induced activation of NF-kappa B is strictly cell type-specific. PMID:8126005

  1. LEDGF/p75-Independent HIV-1 Replication Demonstrates a Role for HRP-2 and Remains Sensitive to Inhibition by LEDGINs

    PubMed Central

    Schrijvers, Rik; De Rijck, Jan; Demeulemeester, Jonas; Adachi, Noritaka; Vets, Sofie; Ronen, Keshet; Christ, Frauke; Bushman, Frederic D.; Debyser, Zeger; Gijsbers, Rik

    2012-01-01

    Lens epithelium–derived growth factor (LEDGF/p75) is a cellular cofactor of HIV-1 integrase (IN) that interacts with IN through its IN binding domain (IBD) and tethers the viral pre-integration complex to the host cell chromatin. Here we report the generation of a human somatic LEDGF/p75 knockout cell line that allows the study of spreading HIV-1 infection in the absence of LEDGF/p75. By homologous recombination the exons encoding the LEDGF/p75 IBD (exons 11 to 14) were knocked out. In the absence of LEDGF/p75 replication of laboratory HIV-1 strains was severely delayed while clinical HIV-1 isolates were replication-defective. The residual replication was predominantly mediated by the Hepatoma-derived growth factor related protein 2 (HRP-2), the only cellular protein besides LEDGF/p75 that contains an IBD. Importantly, the recently described IN-LEDGF/p75 inhibitors (LEDGINs) remained active even in the absence of LEDGF/p75 by blocking the interaction with the IBD of HRP-2. These results further support the potential of LEDGINs as allosteric integrase inhibitors. PMID:22396646

  2. Analysis of Paired Primary-Metastatic Hormone-Receptor Positive Breast Tumors (HRPBC) Uncovers Potential Novel Drivers of Hormonal Resistance

    PubMed Central

    Manso, Luis; Mourón, Silvana; Tress, Michael; Gómez-López, Gonzalo; Morente, Manuel; Ciruelos, Eva; Rubio-Camarillo, Miriam; Rodriguez-Peralto, Jose Luis; Pujana, Miguel A.; Pisano, David G.; Quintela-Fandino, Miguel

    2016-01-01

    We sought to identify genetic variants associated with disease relapse and failure to hormonal treatment in hormone-receptor positive breast cancer (HRPBC). We analyzed a series of HRPBC with distant relapse, by sequencing pairs (n = 11) of tumors (primary and metastases) at >800X. Comparative genomic hybridization was performed as well. Top hits, based on the frequency of alteration and severity of the changes, were tested in the TCGA series. Genes determining the most parsimonious prognostic signature were studied for their functional role in vitro, by performing cell growth assays in hormonal-deprivation conditions, a setting that mimics treatment with aromatase inhibitors. Severe alterations were recurrently found in 18 genes in the pairs. However, only MYC, DNAH5, CSFR1, EPHA7, ARID1B, and KMT2C preserved an independent prognosis impact and/or showed a significantly different incidence of alterations between relapsed and non-relapsed cases in the TCGA series. The signature composed of MYC, KMT2C, and EPHA7 best discriminated the clinical course, (overall survival 90,7 vs. 144,5 months; p = 0.0001). Having an alteration in any of the genes of the signature implied a hazard ratio of death of 3.25 (p<0.0001), and early relapse during the adjuvant hormonal treatment. The presence of the D348N mutation in KMT2C and/or the T666I mutation in the kinase domain of EPHA7 conferred hormonal resistance in vitro. Novel inactivating mutations in KMT2C and EPHA7, which confer hormonal resistance, are linked to adverse clinical course in HRPBC. PMID:27195705

  3. Contribution of Estrone Sulfate to Cell Proliferation in Aromatase Inhibitor (AI) -Resistant, Hormone Receptor-Positive Breast Cancer

    PubMed Central

    Hanamura, Toru; Gohno, Tatsuyuki; Niwa, Toshifumi; Yamaguchi, Yuri; Horiguchi, Jun; Hayashi, Shin-ichi

    2016-01-01

    Aromatase inhibitors (AIs) effectively treat hormone receptor-positive postmenopausal breast cancer, but some patients do not respond to treatment or experience recurrence. Mechanisms of AI resistance include ligand-independent activation of the estrogen receptor (ER) and signaling via other growth factor receptors; however, these do not account for all forms of resistance. Here we present an alternative mechanism of AI resistance. We ectopically expressed aromatase in MCF-7 cells expressing green fluorescent protein as an index of ER activity. Aromatase-overexpressing MCF-7 cells were cultured in estrogen-depleted medium supplemented with testosterone and the AI, letrozole, to establish letrozole-resistant (LR) cell lines. Compared with parental cells, LR cells had higher mRNA levels of steroid sulfatase (STS), which converts estrone sulfate (E1S) to estrone, and the organic anion transporter peptides (OATPs), which mediate the uptake of E1S into cells. LR cells proliferated more in E1S-supplemented medium than did parental cells, and LR proliferation was effectively inhibited by an STS inhibitor in combination with letrozole and by ER-targeting drugs. Analysis of ER-positive primary breast cancer tissues showed a significant correlation between the increases in the mRNA levels of STS and the OATPs in the LR cell lines, which supports the validity of this AI-resistant model. This is the first study to demonstrate the contribution of STS and OATPs in E1S metabolism to the proliferation of AI-resistant breast cancer cells. We suggest that E1S metabolism represents a new target in AI-resistant breast cancer treatment. PMID:27228187

  4. Tetramethylenedisulfotetramine Alters Ca2+ Dynamics in Cultured Hippocampal Neurons: Mitigation by NMDA Receptor Blockade and GABAA Receptor-Positive Modulation

    PubMed Central

    Pessah, Isaac N.

    2012-01-01

    Tetramethylenedisulfotetramine (TETS) is a potent convulsant that is considered a chemical threat agent. We characterized TETS as an activator of spontaneous Ca2+ oscillations and electrical burst discharges in mouse hippocampal neuronal cultures at 13–17 days in vitro using FLIPR Fluo-4 fluorescence measurements and extracellular microelectrode array recording. Acute exposure to TETS (≥ 2µM) reversibly altered the pattern of spontaneous neuronal discharges, producing clustered burst firing and an overall increase in discharge frequency. TETS also dramatically affected Ca2+ dynamics causing an immediate but transient elevation of neuronal intracellular Ca2+ followed by decreased frequency of Ca2+ oscillations but greater peak amplitude. The effect on Ca2+ dynamics was similar to that elicited by picrotoxin and bicuculline, supporting the view that TETS acts by inhibiting type A gamma-aminobutyric acid (GABAA) receptor function. The effect of TETS on Ca2+ dynamics requires activation of N-methyl-d-aspartic acid (NMDA) receptors, because the changes induced by TETS were prevented by MK-801 block of NMDA receptors, but not nifedipine block of L-type Ca2+ channels. Pretreatment with the GABAA receptor-positive modulators diazepam and allopregnanolone partially mitigated TETS-induced changes in Ca2+ dynamics. Moreover, low, minimally effective concentrations of diazepam (0.1µM) and allopregnanolone (0.1µM), when administered together, were highly effective in suppressing TETS-induced alterations in Ca2+ dynamics, suggesting that the combination of positive modulators of synaptic and extrasynaptic GABAA receptors may have therapeutic potential. These rapid throughput in vitro assays may assist in the identification of single agents or combinations that have utility in the treatment of TETS intoxication. PMID:22889812

  5. The GABA(B) receptor positive modulator BHF177 attenuated anxiety, but not conditioned fear, in rats.

    PubMed

    Li, Xia; Kaczanowska, Katarzyna; Finn, M G; Markou, Athina; Risbrough, Victoria B

    2015-10-01

    GABAB (γ-aminobutyric acid B) receptors may be a therapeutic target for anxiety disorders. Here we characterized the effects of the GABAB receptor positive allosteric modulator (PAM) BHF177 on conditioned and unconditioned physiological responses to threat in the light-enhanced startle (LES), stress-induced hyperthermia, and fear-potentiated startle (FPS) procedures in rats. The effects of BHF177 on LES were compared with those of the GABAB receptor agonists baclofen and CGP44532, and the positive control buspirone, a 5-HT1A receptor partial agonist with anxiolytic activity in humans. Baclofen (0.4, 0.9 and 1.25 mg/kg) and CGP44532 (0.065, 0.125 and 0.25 mg/kg) administration had significant sedative, but not anxiolytic, activity reflected in overall decrease in the startle response in the LES tests. BHF177 (10, 20 and 40 mg/kg) had no effect on LES, nor did it produce an overall sedative effect. Interesting, however, when rats were grouped by high and low LES responses, BHF177 had anxiolytic-like effects only on LES in high, but not low, LES responding rats. BHF177 also blocked stress-induced hyperthermia, but had no effect on conditioned fear responses in the FPS test. Buspirone (1 and 3 mg/kg) had an anxiolytic-like profile in both LES and FPS tests. These results indicate that BHF177 may specifically attenuate unconditioned anxiety in individuals that exhibit a high anxiety state, and has fewer sedative effects than direct agonists. Thus, BHF177 or other GABAB receptor PAMs may be promising compounds for alleviating increased anxiety seen in various psychiatric disorders with a superior side-effect profile compared to GABAB receptor agonists. PMID:26002628

  6. Dosing and Safety Implications for Oncologists When Administering Everolimus to Patients With Hormone Receptor-Positive Breast Cancer.

    PubMed

    Rugo, Hope S

    2016-02-01

    Aberrations in the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin pathway are common abnormalities in breast cancer and are associated with the development of resistance to endocrine- and human epidermal growth factor receptor (HER)2-targeted therapies. Because of the significant improvement in progression-free survival for everolimus plus exemestane compared with exemestane plus placebo, everolimus, an mTOR inhibitor, was approved in the United States for the treatment of patients with hormone receptor-positive (HR+), HER-negative, advanced breast cancer whose disease had progressed while receiving letrozole or anastrozole. To provide optimal prevention and management strategies, it is crucial that clinicians are aware of the adverse events (AEs) associated with mTOR inhibition. Understanding the appropriate dose modifications will help reduce toxicity and improve drug tolerance, thus achieving the optimal benefit from everolimus. Analyses of data from the Breast Cancer Trials of Oral Everolimus 2 trial have shown that, despite a greater frequency of AEs in the everolimus plus exemestane treatment arm, the AEs were effectively managed with temporary dose reductions or interruptions. In some cases, the full dose of everolimus could be resumed. Despite a lower mean dose and duration of exposure in patients aged ≥ 70 versus < 70 years, everolimus plus exemestane was similarly efficacious, suggesting that appropriate dose reductions for toxicity will not adversely impact efficacy. Appropriate modification of the everolimus dose and dose delay according to the severity of AEs, with resumption of the optimal dose of everolimus when toxicity has improved, will positively affect patient outcomes in HR+ advanced breast cancer. PMID:26507507

  7. The 5p12 breast cancer susceptibility locus affects MRPS30 expression in estrogen-receptor positive tumors

    PubMed Central

    Quigley, David A.; Fiorito, Elisa; Nord, Silje; Van Loo, Peter; Alnæs, Grethe Grenaker; Fleischer, Thomas; Tost, Jorg; Vollan, Hans Kristian Moen; Tramm, Trine; Overgaard, Jens; Bukholm, Ida R; Hurtado, Antoni; Balmain, Allan; Børresen-Dale, Anne-Lise; Kristensen, Vessela

    2014-01-01

    Genome-wide association studies have identified numerous loci linked to breast cancer susceptibility, but the mechanism by which variations at these loci influence susceptibility is usually unknown. Some variants are only associated with particular clinical subtypes of breast cancer. Understanding how and why these variants influence subtype-specific cancer risk contributes to our understanding of cancer etiology. We conducted a genome-wide expression Quantitative Trait Locus (eQTL) study in a discovery set of 287 breast tumors and 97 normal mammary tissue samples and a replication set of 235 breast tumors. We found that the risk-associated allele of rs7716600 in the 5p12 estrogen receptor-positive (ER-positive) susceptibility locus was associated with elevated expression of the nearby gene MRPS30 exclusively in ER-positive tumors. We replicated this finding in 235 independent tumors. Further, we showed the rs7716600 risk genotype was associated with decreased MRPS30 promoter methylation exclusively in ER-positive breast tumors. In vitro studies in MCF-7 cells carrying the protective genotype showed that estrogen stimulation decreased MRPS30 promoter chromatin availability and mRNA levels. In contrast, in 600MPE cells carrying the risk genotype, estrogen increased MRPS30 expression and did not affect promoter availability. Our data suggest the 5p12 risk allele affects MRPS30 expression in estrogen-responsive tumor cells after tumor initiation by a mechanism affecting chromatin availability. These studies emphasize that the genetic architecture of breast cancer is context-specific, and integrated analysis of gene expression and chromatin remodeling in normal and tumor tissues will be required to explain the mechanisms of risk alleles. PMID:24388359

  8. Analysis of Paired Primary-Metastatic Hormone-Receptor Positive Breast Tumors (HRPBC) Uncovers Potential Novel Drivers of Hormonal Resistance.

    PubMed

    Manso, Luis; Mourón, Silvana; Tress, Michael; Gómez-López, Gonzalo; Morente, Manuel; Ciruelos, Eva; Rubio-Camarillo, Miriam; Rodriguez-Peralto, Jose Luis; Pujana, Miguel A; Pisano, David G; Quintela-Fandino, Miguel

    2016-01-01

    We sought to identify genetic variants associated with disease relapse and failure to hormonal treatment in hormone-receptor positive breast cancer (HRPBC). We analyzed a series of HRPBC with distant relapse, by sequencing pairs (n = 11) of tumors (primary and metastases) at >800X. Comparative genomic hybridization was performed as well. Top hits, based on the frequency of alteration and severity of the changes, were tested in the TCGA series. Genes determining the most parsimonious prognostic signature were studied for their functional role in vitro, by performing cell growth assays in hormonal-deprivation conditions, a setting that mimics treatment with aromatase inhibitors. Severe alterations were recurrently found in 18 genes in the pairs. However, only MYC, DNAH5, CSFR1, EPHA7, ARID1B, and KMT2C preserved an independent prognosis impact and/or showed a significantly different incidence of alterations between relapsed and non-relapsed cases in the TCGA series. The signature composed of MYC, KMT2C, and EPHA7 best discriminated the clinical course, (overall survival 90,7 vs. 144,5 months; p = 0.0001). Having an alteration in any of the genes of the signature implied a hazard ratio of death of 3.25 (p<0.0001), and early relapse during the adjuvant hormonal treatment. The presence of the D348N mutation in KMT2C and/or the T666I mutation in the kinase domain of EPHA7 conferred hormonal resistance in vitro. Novel inactivating mutations in KMT2C and EPHA7, which confer hormonal resistance, are linked to adverse clinical course in HRPBC. PMID:27195705

  9. Round-window delivery of neurotrophin 3 regenerates cochlear synapses after acoustic overexposure.

    PubMed

    Suzuki, Jun; Corfas, Gabriel; Liberman, M Charles

    2016-01-01

    In acquired sensorineural hearing loss, such as that produced by noise or aging, there can be massive loss of the synaptic connections between cochlear sensory cells and primary sensory neurons, without loss of the sensory cells themselves. Because the cell bodies and central projections of these cochlear neurons survive for months to years, there is a long therapeutic window in which to re-establish functional connections and improve hearing ability. Here we show in noise-exposed mice that local delivery of neurotrophin-3 (NT-3) to the round window niche, 24 hours after an exposure that causes an immediate loss of up to 50% loss of synapses in the cochlear basal region, can regenerate pre- and post-synaptic elements at the hair cell / cochlear nerve interface. This synaptic regeneration, as documented by confocal microscopy of immunostained cochlear sensory epithelia, was coupled with a corresponding functional recovery, as seen in the suprathreshold amplitude of auditory brainstem response Wave 1. Cochlear delivery of neurotrophins in humans is likely achievable as an office procedure via transtympanic injection, making our results highly significant in a translational context. PMID:27108594

  10. Round-window delivery of neurotrophin 3 regenerates cochlear synapses after acoustic overexposure

    PubMed Central

    Suzuki, Jun; Corfas, Gabriel; Liberman, M. Charles

    2016-01-01

    In acquired sensorineural hearing loss, such as that produced by noise or aging, there can be massive loss of the synaptic connections between cochlear sensory cells and primary sensory neurons, without loss of the sensory cells themselves. Because the cell bodies and central projections of these cochlear neurons survive for months to years, there is a long therapeutic window in which to re-establish functional connections and improve hearing ability. Here we show in noise-exposed mice that local delivery of neurotrophin-3 (NT-3) to the round window niche, 24 hours after an exposure that causes an immediate loss of up to 50% loss of synapses in the cochlear basal region, can regenerate pre- and post-synaptic elements at the hair cell / cochlear nerve interface. This synaptic regeneration, as documented by confocal microscopy of immunostained cochlear sensory epithelia, was coupled with a corresponding functional recovery, as seen in the suprathreshold amplitude of auditory brainstem response Wave 1. Cochlear delivery of neurotrophins in humans is likely achievable as an office procedure via transtympanic injection, making our results highly significant in a translational context. PMID:27108594

  11. Neurotrophins and their Trk-receptors in the cerebellum of zebrafish.

    PubMed

    Gatta, Claudia; Altamura, Gennaro; Avallone, Luigi; Castaldo, Luciana; Corteggio, Annunziata; D'Angelo, Livia; de Girolamo, Paolo; Lucini, Carla

    2016-06-01

    Neurotrophins (NTs) and their specific Trk-receptors are key molecules involved in the regulation of survival, proliferation, and differentiation of central nervous system during development and adulthood in vertebrates. In the present survey, we studied the expression and localization of neurotrophins and their Trk-receptors in the cerebellum of teleost fish Danio rerio (zebrafish). Teleostean cerebellum is composed of a valvula, body and vestibulolateral lobe. Valvula and body show the same three-layer structure as cerebellar cortex in mammals. The expression of NTs and Trk-receptors in the whole brain of zebrafish has been studied by Western blotting analysis. By immunohistochemistry, the localization of NTs has been observed mainly in Purkinje cells; TrkA and TrkB-receptors in cells and fibers of granular and molecular layers. TrkC was faintly detected. The occurrence of NTs and Trk-receptors suggests that they could have a synergistic action in the cerebellum of zebrafish. J. Morphol. 277:725-736, 2016. © 2016 Wiley Periodicals, Inc. PMID:27197756

  12. Neurotrophins and specific receptors in the oviduct tracts of Japanese quail (Coturnix coturnix japonica).

    PubMed

    Maruccio, L; Castaldo, L; D'Angelo, L; Gatta, C; Lucini, C; Cotea, C; Solcan, C; Nechita, E L

    2016-09-01

    Neurotrophins (NGF, BDNF and NT-3) and their specific receptors (TrkA, TrkB and TrkC) were studied in the oviduct of egg laying quails. Neurotrophins (NTs) are mainly involved in the development and maintenance of neuronal populations in the central and peripheral nervous system, but also in reproductive system. In this survey, we first studied the morphological organization of the quail oviduct, distinguished in infundibulum, magnum, isthmus, uterus and vagina, and then we analyzed the expression and localization of NTs and Trks receptors in the whole tracts. By western blotting we detected that the investigated NTs and Trks receptors are expressed in all oviductal tracts. By immunohistochemistry we were able to define the distribution of NTs and Trks. Specifically, NGF, BDNF and NT3 were localized in lining and ductal epithelial cells, and NGF was also detected in secretory cells of tubular glands and in nervous fibers of vessel wall. TrkA and TrkB were present in the lining and ductal epithelium; TrkA and TrkC were present in nervous fibers of vessel wall in all oviductal tracts. Furthermore, we also observed NGF and BDNF co-localized with TrkA and TrkB in cells of the lining and ductal epithelium, suggesting an autocrine mechanism of action. PMID:27167968

  13. Immunohistochemical profile of neurotrophins in human cranial dura mater and meningiomas.

    PubMed

    Artico, Marco; Bronzetti, Elena; Pompili, Elena; Ionta, Brunella; Alicino, Valentina; D'Ambrosio, Anna; Santoro, Antonio; Pastore, Francesco S; Elenkov, Ilia; Fumagalli, Lorenzo

    2009-06-01

    The immunohistochemical profile of neurotrophins and their receptors in the human cranial dura mater was studied by examining certain dural zones in specimens harvested from different regions (frontal, temporal, parietal and occipital). Dural specimens were obtained during neurosurgical operations performed in ten patients for surgical treatment of intracranial lesions (meningiomas, traumas, gliomas, vascular malformations). The dural fragments were taken from the area of the craniotomy at least 8 cm from the lesion as well as from the area in which the meningioma had its dural attachment. Immunohistochemical characterization and distribution of neurotrophins, with their receptors, were analyzed. The concrete role played by these neurotrophic factors in general regulation, vascular permeability, algic responsivity and release of locally active substances in the human dura mater is still controversial. Our study revealed a general structural alteration of dural tissue due to the invasivity of meningiomatous lesions, together with an improved expression of brain derived neurotrophic factor (BDNF) in highly proliferating neoplastic cells and an evident production of nerve growth factor (NGF) in inflammatory cells, suggesting that BDNF has a role in supporting the proliferation rate of neoplastic cells, while NGF is involved in the activation of a chronic inflammatory response in neoplastic areas. PMID:19424612

  14. The major secreted protein Msp1/p75 is O-glycosylated in Lactobacillus rhamnosus GG

    PubMed Central

    2012-01-01

    Background Although the occurrence, biosynthesis and possible functions of glycoproteins are increasingly documented for pathogens, glycoproteins are not yet widely described in probiotic bacteria. Nevertheless, knowledge of protein glycosylation holds important potential for better understanding specific glycan-mediated interactions of probiotics and for glycoengineering in food-grade microbes. Results Here, we provide evidence that the major secreted protein Msp1/p75 of the probiotic Lactobacillus rhamnosus GG is glycosylated. Msp1 was shown to stain positive with periodic-acid Schiff staining, to be susceptible to chemical deglycosylation, and to bind with the mannose-specific Concanavalin A (ConA) lectin. Recombinant expression in Escherichia coli resulted in a significant reduction in molecular mass, loss of ConA reactivity and increased sensitivity towards pronase E and proteinase K. Mass spectrometry showed that Msp1 is O-glycosylated and identified a glycopeptide TVETPSSA (amino acids 101-108) bearing hexoses presumably linked to the serine residues. Interestingly, these serine residues are not present in the homologous protein of several Lactobacillus casei strains tested, which also did not bind to ConA. The role of the glycan substitutions in known functions of Msp1 was also investigated. Glycosylation did not seem to impact significantly on the peptidoglycan hydrolase activity of Msp1. In addition, the glycan chain appeared not to be required for the activation of Akt signaling in intestinal epithelial cells by Msp1. On the other hand, examination of different cell extracts showed that Msp1 is a glycosylated protein in the supernatant, but not in the cell wall and cytosol fraction, suggesting a link between glycosylation and secretion of this protein. Conclusions In this study we have provided the first evidence of protein O-glycosylation in the probiotic L rhamnosus GG. The major secreted protein Msp1 is glycosylated with ConA reactive sugars at the

  15. An extended surface of binding to Trk tyrosine kinase receptors in NGF and BDNF allows the engineering of a multifunctional pan-neurotrophin.

    PubMed Central

    Ibáñez, C F; Ilag, L L; Murray-Rust, J; Persson, H

    1993-01-01

    Neurotrophin-mediated cell survival and differentiation of vertebrate neurons is caused by ligand-specific binding to the Trk family of tyrosine kinase receptors. However, sites in the neurotrophins responsible for the binding to Trk receptors and the mechanisms whereby this interaction results in receptor activation and biological activity are unknown. Here we show that in nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), discontinuous stretches of amino acid residues group together on one side of the neurotrophin dimer forming a continuous surface responsible for binding to and activation of TrkA and TrkB receptors. Two symmetrical surfaces are formed along the two-fold axis of the neurotrophin dimer providing a model for ligand-mediated receptor dimerization. Mutated neurotrophins inducing similar levels of receptor phosphorylation showed different biological activities, suggesting that structural differences in a ligand may result in dissimilar responses in a given tyrosine kinase receptor. Our results allowed us to combine structural elements from NGF, BDNF and neurotrophin-3 to engineer a pan-neurotrophin that efficiently activates all Trk receptors and displays multiple neurotrophic specificities. Images PMID:8508763

  16. The role of tropomyosin-related kinase receptors in neurotrophin-induced rapid eye movement sleep in the cat.

    PubMed

    Yamuy, J; Ramos, O; Torterolo, P; Sampogna, S; Chase, M H

    2005-01-01

    The microinjection of nerve growth factor and neurotrophin-3 into the rostro-dorsal pontine tegmentum of the cat evokes a state that is comparable to naturally-occurring rapid eye movement sleep. Using two experimental paradigms, we tested the hypothesis that neurotrophin high-affinity receptors (trkA and trkC, tropomyosin-related kinase A and C, respectively) mediate this effect. First, trk and fos immunohistochemistry were combined to determine whether tyrosine kinase receptor-containing neurons in the dorsal pontine tegmentum are active in cats that exhibit long-lasting periods of rapid eye movement sleep following the local microinjection of nerve growth factor. During approximately two hours of recording, nerve growth factor-treated cats spent 59.8% of the time in a rapid eye movement sleep-like state; vehicle-injected (control) animals remained in quiet wakefulness and non-rapid eye movement sleep. Whereas control and nerve growth factor-treated cats exhibited a similar mean number of trkA- and trkC-immunoreactive neurons in the dorsal pontine tegmentum, the number of trkA- and trkC-immunoreactive neurons that expressed Fos, i.e. double-labeled cells that are presumably activated, was significantly larger in cats that were injected with nerve growth factor. Axon terminals contained tyrosine kinase receptor immunoreactivity in this region; many were apposed to Fos-immunoreactive neurons. In addition, patterns of tyrosine kinase receptor and Fos immunoreactivity similar to those observed in nerve growth factor-injected cats were present, in conjunction with long-lasting rapid eye movement sleep, following the microinjection of carbachol into the dorsal pons. In a second series of studies, nerve growth factor or neurotrophin-3 was injected alone or after K-252a, a blocker of tyrosine kinase receptors, into the rostro-dorsal pontine tegmentum. Nerve growth factor or neurotrophin-3 alone produced, with a mean latency of 4 min, a rapid eye movement sleep-like state

  17. Cost-effectiveness analysis of everolimus plus exemestane versus exemestane alone for treatment of hormone receptor positive metastatic breast cancer.

    PubMed

    Diaby, Vakaramoko; Adunlin, Georges; Zeichner, Simon B; Avancha, Kiran; Lopes, Gilberto; Gluck, Stefan; Montero, Alberto J

    2014-09-01

    Everolimus in combination with exemestane significantly improved progression-free survival compared to exemestane alone in patients previously treated with non-steroidal aromatase inhibitors in the BOLERO-2 trial. As a result, this combination has been approved by the food and drug administration to treat postmenopausal women with hormone receptor positive and HER2 negative metastatic breast cancer. A cost-effectiveness analysis was conducted to determine whether everolimus represents good value for money, utilizing data from BOLERO-2. A decision-analytic model was used to estimate the incremental cost-effectiveness ratio between treatment arms of the BOLERO-2 trial. Costs were obtained from the Center for Medicare Services drug payment table and physician fee schedule. Benefits were expressed as quality-adjusted progression-free survival weeks (QAPFW) and quality-adjusted progression-free years (QAPFY), with utilities/disutilities derived from the literature. Deterministic and probabilistic sensitivity analyses were performed. A willingness to pay threshold of 1-3 times the per capita gross domestic product was adopted, as per the definition of the World Health Organization. The U.S. per capita gross domestic product in 2013 was $49,965; thus, a threshold varying between $49,965 and $149,895 was considered. Everolimus/exemestane had an incremental benefit of 11.88 QAPFW (0.22 QAPFY) compared to exemestane and an incremental cost of $60,574. This translated into an ICER of $265,498.5/QAPFY. Univariate sensitivity analyses showed important variations of the ICER, ranging between $189,836.4 and $530,947/QAPFY. A tornado analysis suggested that the key drivers of our model, by order of importance, included health utility value for stable disease, everolimus acquisition costs, and transition probabilities from the stable to the progression states. The Monte-Carlo simulation showed results that were similar to the base-case analysis. This cost-effectiveness analysis

  18. Hormonal-receptor positive breast cancer: IL-6 augments invasion and lymph node metastasis via stimulating cathepsin B expression.

    PubMed

    Ibrahim, Sherif A; El-Ghonaimy, Eslam A; Hassan, Hebatallah; Mahana, Noha; Mahmoud, Mahmoud Abdelbaky; El-Mamlouk, Tahani; El-Shinawi, Mohamed; Mohamed, Mona M

    2016-09-01

    Hormonal-receptor positive (HRP) breast cancer patients with positive metastatic axillary lymph nodes are characterized by poor prognosis and increased mortality rate. The mechanisms by which cancer cells invade lymph nodes have not yet been fully explored. Several studies have shown that expression of IL-6 and the proteolytic enzyme cathepsin B (CTSB) was associated with breast cancer poor prognosis. In the present study, the effect of different concentrations of recombinant human IL-6 on the invasiveness capacity of HRP breast cancer cell line MCF-7 was tested using an in vitro invasion chamber assay. The impact of IL-6 on expression and activity of CTSB was also investigated. IL-6 treatment promoted the invasiveness potential of MCF-7 cells in a dose-dependent manner. Furthermore, MCF-7 cells displayed elevated CTSB expression and activity associated with loss of E-cadherin and upregulation of vimentin protein levels upon IL-6 stimulation. To validate these results in vivo, the level of expression of IL-6 and CTSB in the carcinoma tissues of HRP-breast cancer patients with positive and negative axillary metastatic lymph nodes (pLNs and nLNs) was assessed. Western blot and immunohistochemical staining data showed that expression of IL-6 and CTSB was higher in carcinoma tissues in HRP-breast cancer with pLNs than those with nLNs patients. ELISA results showed carcinoma tissues of HRP-breast cancer with pLNs exhibited significantly elevated IL-6 protein levels by approximately 2.8-fold compared with those with nLNs patients (P < 0.05). Interestingly, a significantly positive correlation between IL-6 and CTSB expression was detected in clinical samples of HRP-breast cancer patients with pLNs (r = 0.78, P < 0.01). Collectively, this study suggests that IL-6-induced CTSB may play a role in lymph node metastasis, and that may possess future therapeutic implications for HRP-breast cancer patients with pLNs. Further studies are necessary to fully identify IL-6/CTSB

  19. Abiraterone acetate, exemestane or the combination in postmenopausal patients with estrogen receptor-positive metastatic breast cancer†

    PubMed Central

    O'Shaughnessy, J.; Campone, M.; Brain, E.; Neven, P.; Hayes, D.; Bondarenko, I.; Griffin, T. W.; Martin, J.; De Porre, P.; Kheoh, T.; Yu, M. K.; Peng, W.; Johnston, S.

    2016-01-01

    Background Androgen receptor (AR) signaling and incomplete inhibition of estrogen signaling may contribute to metastatic breast cancer (MBC) resistance to a nonsteroidal aromatase inhibitor (NSAI; letrozole or anastrozole). We assessed whether combined inhibition of androgen biosynthesis with abiraterone acetate plus prednisone and estradiol synthesis with exemestane (E) may be of clinical benefit to postmenopausal patients with NSAI-pretreated estrogen receptor-positive (ER+) MBC. Patients and methods Patients (N = 297) were stratified by the number of prior therapies for metastatic disease (0–1 versus 2) and by prior NSAI use (adjuvant versus metastatic), and randomized (1 : 1 : 1) to receive oral once daily 1000 mg abiraterone acetate plus 5 mg prednisone (AA) versus AA with 25 mg E (AAE) versus 25 mg E alone (E). Each treatment arm was well balanced with regard to the proportion of patients with AR-positive breast cancer. The primary end point was progression-free survival (PFS). Secondary end points included overall survival, clinical benefit rate, duration of response, and overall response rate. Results There was no significant difference in PFS with AA versus E (3.7 versus 3.7 months; hazard ratio [HR] = 1.1; 95% confidence interval [CI] 0.82–1.60; P = 0.437) or AAE versus E (4.5 versus 3.7 months; HR = 0.96; 95% CI 0.70–1.32; P = 0.794). Increased serum progesterone concentrations were observed in both arms receiving AA, but not with E. Grade 3 or 4 treatment-emergent adverse events associated with AA, including hypokalemia and hypertension, were less common in patients in the E (2.0% and 2.9%, respectively) and AA arms (3.4% and 1.1%, respectively) than in the AAE arm (5.8% for both). Conclusions Adding AA to E in NSAI-pretreated ER+ MBC patients did not improve PFS compared with treatment with E. An AA-induced progesterone increase may have contributed to this lack of clinical activity. ClinicalTrials.gov NCT01381874. PMID:26504153

  20. A pooled analysis of post-diagnosis lifestyle factors in association with late estrogen-receptor-positive breast cancer prognosis.

    PubMed

    Nechuta, Sarah; Chen, Wendy Y; Cai, Hui; Poole, Elizabeth M; Kwan, Marilyn L; Flatt, Shirley W; Patterson, Ruth E; Pierce, John P; Caan, Bette J; Ou Shu, Xiao

    2016-05-01

    Lifestyle factors have been well studied in relation to breast cancer prognosis overall; however, associations of lifestyle and late outcomes (>5 years after diagnosis) have been much less studied, and no studies have focused on estrogen receptor-positive (ER+) breast cancer survivors, who may have high risk of late recurrence and mortality. We utilized a large prospective pooling study to evaluate the associations of lifestyle factors with late recurrence and all-cause mortality among 6,295 5-year ER+ Stage I-III breast cancer survivors. Pooled and harmonized data were available on clinical factors and lifestyle factors (pre- to post-diagnosis weight change, body mass index (BMI) (kg/m(2)), recreational physical activity, alcohol intake and smoking history), measured on average 2.1 years after diagnosis. Updated information for weight only was available. Study heterogeneity was evaluated by the Q-statistic. Multivariable Cox regression models were stratified by study. Adjusting for clinical factors and potential confounders, ≥ 10% weight gain and obesity (BMI, 30-34.99 and ≥ 35) were associated with increased risk of late recurrence (hazard ratios (95% confidence intervals): 1.24 (1.00-1.53), 1.40 (1.05-1.86) and 1.41 (1.02-1.93), respectively). Daily alcohol intake was associated with late recurrence, 1.28 (1.01-1.62). Physical activity was inversely associated with late all-cause mortality (0.81 (0.71-0.93) and 0.71 (0.61-0.82) for 4.9 to <17.4 and ≥ 17.4 metabolic equivalent-hr/week). A U-shaped association was observed for late all-cause mortality and BMI using updated weight (1.42 (1.15-1.74) and 1.40 (1.09-1.81), <21.5 and ≥ 35, respectively). Smoking was associated with increased risk of late outcomes. In this large prospective pooling project, modifiable lifestyle factors were associated with late outcomes among long-term ER+ breast cancer survivors. PMID:26606746

  1. Neurotrophin-3 Enhances the Synaptic Organizing Function of TrkC-Protein Tyrosine Phosphatase σ in Rat Hippocampal Neurons.

    PubMed

    Ammendrup-Johnsen, Ina; Naito, Yusuke; Craig, Ann Marie; Takahashi, Hideto

    2015-09-01

    Neurotrophin-3 (NT-3) and its high-affinity receptor TrkC play crucial trophic roles in neuronal differentiation, axon outgrowth, and synapse development and plasticity in the nervous system. We demonstrated previously that postsynaptic TrkC functions as a glutamatergic synapse-inducing (synaptogenic) cell adhesion molecule trans-interacting with presynaptic protein tyrosine phosphatase σ (PTPσ). Given that NT-3 and PTPσ bind distinct domains of the TrkC extracellular region, here we tested the hypothesis that NT-3 modulates TrkC/PTPσ binding and synaptogenic activity. NT-3 enhanced PTPσ binding to cell surface-expressed TrkC and facilitated the presynapse-inducing activity of TrkC in rat hippocampal neurons. Imaging of recycling presynaptic vesicles combined with TrkC knockdown and rescue approaches demonstrated that NT-3 rapidly potentiates presynaptic function via binding endogenous postsynaptic TrkC in a tyrosine kinase-independent manner. Thus, NT-3 positively modulates the TrkC-PTPσ complex for glutamatergic presynaptic assembly and function independently from TrkC kinase activation. Our findings provide new insight into synaptic roles of neurotrophin signaling and mechanisms controlling synaptic organizing complexes. Significance statement: Although many synaptogenic adhesion complexes have been identified in recent years, little is known about modulatory mechanisms. Here, we demonstrate a novel role of neurotrophin-3 in synaptic assembly and function as a positive modulator of the TrkC-protein tyrosine phosphatase σ complex. This study provides new insight into the involvement of neurotrophin signaling in synapse development and plasticity, presenting a molecular mechanism that may underlie previous observations of short- and long-term enhancement of presynaptic function by neurotrophin. Given the links of synaptogenic adhesion molecules to autism and schizophrenia, this study might also contribute to a better understanding of the pathogenesis of

  2. In vivo application of ( sup 111 In-DTPA-D-Phe sup 1 )-octreotide for detection of somatostatin receptor-positive tumors in rats

    SciTech Connect

    Bakker, W.H.; Krenning, E.P.; Reubi, J.C.; Breeman, W.A.P.; Setyono-Han, B.; de Jong, M.; Kooij, P.P.M.; Bruns, C.; van Hagen, P.M.; Marbach, P.; Visser, T.J.; Pless, J.; Lamberts, S.W.J. Sandoz Research Inst., Berne Dr. Daniel den Hoed Cancer Centre, Rotterdam Sandoz Pharma AG, Basel )

    1991-01-01

    In this study the authors investigated its in vivo application in the visualization of somatostatin receptor-positive tumors in rats. The distribution of the radiopharmaceutical was investigated after intravenous injection in normal rats and in rats bearing the somatostatin receptor-positive rat pancreatic carcinoma CA 20948. Ex vivo autoradiographic studies showed that specific accumulation of radioactivity occurred in somatostatin receptor-containing tissue (anterior pituitary gland). However, in contrast to the adrenals and pituitary, the tracer accumulation in the kidneys was not mediated by somatostatin receptors. Increasing radioactivity over the somatostatin receptor-positive tumors was measured rapidly after injection and the tumors were clearly visualized by gamma camera scintigraphy. In rats pretreated with 1 mg octreotide accumulation of ({sup 111}In-DPTA-D-Phe{sup 1})-octreotide in the tumors was prevented. Because of its relatively long effective half-life, ({sup 111}In-DTPA-D-Phe{sup 1})-octreotide is a radionuclide-coupled somatostatin analogue which can be used to visualize somatostatin receptor-bearing tumors efficiently after 24 hr, when interfering background radioactivity is minimized by renal clearance.

  3. p75, a polypeptide component of karyoskeletal protein-enriched fractions associated with transcriptionally active loci of Drosophila melanogaster polytene chromosomes.

    PubMed Central

    Benton, B M; Berrios, S; Fisher, P A

    1988-01-01

    A 75-kilodalton polypeptide has been identified which copurifies with karyoskeletal protein-enriched fractions prepared from Drosophila melanogaster embryos. Results of indirect immunofluorescence experiments suggest that this protein, here designated p75, is primarily associated with puffed regions of larval salivary gland polytene chromosomes. In nonpolytenized Schneider 2 tissue culture cells, p75 appeared to be localized throughout the nuclear interior during interphase. In mitotic cells, p75 was redistributed diffusely. A possible role for karyoskeletal elements in transcriptional regulation is discussed. Images PMID:3133549

  4. Minocycline inhibits the production of the precursor form of nerve growth factor by retinal microglial cells☆

    PubMed Central

    Yang, Xiaochun; Duan, Xuanchu

    2013-01-01

    A rat model of acute ocular hypertension was established by enhancing the perfusion of balanced salt solution in the anterior chamber of the right eye. Minocycline (90 mg/kg) was administered intraperitoneally into rats immediately after the operation for 3 consecutive days. Immunofluorescence, western blot assay and PCR detection revealed that the expression of the precursor form of nerve growth factor, nerve growth factor and the p75 neurotrophin receptor, and the mRNA expression of nerve growth factor and the p75 neurotrophin receptor, increased after acute ocular hypertension. The number of double-labeled CD11B- and precursor form of nerve growth factor-positive cells, glial fibrillary acidic protein- and p75 neurotrophin receptor-positive cells, glial fibrillary acidic protein- and caspase-3-positive cells in the retina markedly increased after acute ocular hypertension. The above-described expression decreased after minocycline treatment. These results suggested that minocycline inhibited the increased expression of the precursor form of nerve growth factor in microglia, the p75 neurotrophin receptor in astroglia, and protected cells from apoptosis. PMID:25206672

  5. Deletion of a kinesin I motor unmasks a mechanism of homeostatic branching control by neurotrophin-3.

    PubMed

    Auer, Thomas O; Xiao, Tong; Bercier, Valerie; Gebhardt, Christoph; Duroure, Karine; Concordet, Jean-Paul; Wyart, Claire; Suster, Maximiliano; Kawakami, Koichi; Wittbrodt, Joachim; Baier, Herwig; Del Bene, Filippo

    2015-01-01

    Development and function of highly polarized cells such as neurons depend on microtubule-associated intracellular transport, but little is known about contributions of specific molecular motors to the establishment of synaptic connections. In this study, we investigated the function of the Kinesin I heavy chain Kif5aa during retinotectal circuit formation in zebrafish. Targeted disruption of Kif5aa does not affect retinal ganglion cell differentiation, and retinal axons reach their topographically correct targets in the tectum, albeit with a delay. In vivo dynamic imaging showed that anterograde transport of mitochondria is impaired, as is synaptic transmission. Strikingly, disruption of presynaptic activity elicits upregulation of Neurotrophin-3 (Ntf3) in postsynaptic tectal cells. This in turn promotes exuberant branching of retinal axons by signaling through the TrkC receptor (Ntrk3). Thus, our study has uncovered an activity-dependent, retrograde signaling pathway that homeostatically controls axonal branching. PMID:26076409

  6. Immune and neurotrophin stimulation by electroconvulsive therapy: is some inflammation needed after all?

    PubMed

    van Buel, E M; Patas, K; Peters, M; Bosker, F J; Eisel, U L M; Klein, H C

    2015-01-01

    A low-grade inflammatory response is commonly seen in the peripheral blood of major depressive disorder (MDD) patients, especially those with refractory and chronic disease courses. However, electroconvulsive therapy (ECT), the most drastic intervention reserved for these patients, is closely associated with an enhanced haematogenous as well as neuroinflammatory immune response, as evidenced by both human and animal studies. A related line of experimental evidence further shows that inflammatory stimulation reinforces neurotrophin expression and may even mediate dramatic neurogenic and antidepressant-like effects following exposure to chronic stress. The current review therefore attempts a synthesis of our knowledge on the neurotrophic and immunological aspects of ECT and other electrically based treatments in psychiatry. Perhaps contrary to contemporary views, we conclude that targeted potentiation, rather than suppression, of inflammatory responses may be of therapeutic relevance to chronically depressed patients or a subgroup thereof. PMID:26218851

  7. Differential Cortical Neurotrophin and Cytogenetic Adaptation after Voluntary Exercise in Normal and Amnestic Rats

    PubMed Central

    Hall, Joseph M.; Vetreno, Ryan P.; Savage, Lisa M.

    2013-01-01

    Voluntary exercise (VEx) has profound effects on neural and behavioral plasticity, including recovery of CNS trauma and disease. However, the unique regional cortical adaption to VEx has not been elucidated. In a series of experiments, we first examined whether VEx would restore and retain neurotrophin levels in several cortical regions (frontal cortex [FC], retrosplenial cortex [RSC], occipital cortex [OC]) in an animal model (pyrithiamine-induced thiamine deficiency [PTD]) of the amnestic disorder Wernicke-Korsakoff syndrome. In addition, we assessed the time-dependent effect of VEx to rescue performance on a spontaneous alternation task. Following 2-weeks of VEx or stationary housing conditions (Stat), rats were behaviorally tested and brains were harvested either the day after VEx (24-h) or after an additional two-week period (2-wk). In both control pair-fed (PF) rats and PTD rats, all neurotrophin levels (brain-derived neurotrophic factor [BDNF], nerve growth factor [NGF], and vascular endothelial growth factor [VEGF]) increased at the 24-h period after VEx in the FC and RSC, but not OC. Two-weeks following VEx, BDNF remained elevated in both FC and RSC, whereas NGF remained elevated in only the FC. Interestingly, VEx only recovered cognitive performance in amnestic rats when there was an additional 2-wk adaptation period after VEx. Given this unique temporal profile, Experiment 2 examined the cortical cytogenetic responses in all three cortical regions following a 2-wk adaptation period after VEx. In healthy (PF) rats, VEx increased the survival of progenitor cells in both the FC and RSC, but only increased oligodendrocyte precursor cells in the FC. Furthermore, VEx had a selective effect of only recovering oligodendrocyte precursor cells in the FC in PTD rats. These data reveal the therapeutic potential of exercise to restore cortical plasticity in the amnestic brain, and that the FC is one of the most responsive cortical regions to VEx. PMID:24215977

  8. Differential cortical neurotrophin and cytogenetic adaptation after voluntary exercise in normal and amnestic rats.

    PubMed

    Hall, J M; Vetreno, R P; Savage, L M

    2014-01-31

    Voluntary exercise (VEx) has profound effects on neural and behavioral plasticity, including recovery of CNS trauma and disease. However, the unique regional cortical adaption to VEx has not been elucidated. In a series of experiments, we first examined whether VEx would restore and retain neurotrophin levels in several cortical regions (frontal cortex [FC], retrosplenial cortex [RSC], occipital cortex [OC]) in an animal model (pyrithiamine-induced thiamine deficiency [PTD]) of the amnestic disorder Wernicke-Korsakoff syndrome. In addition, we assessed the time-dependent effect of VEx to rescue performance on a spontaneous alternation task. Following 2-weeks of VEx or stationary housing conditions (Stat), rats were behaviorally tested and brains were harvested either the day after VEx (24-h) or after an additional 2-week period (2-wk). In both control pair-fed (PF) rats and PTD rats, all neurotrophin levels (brain-derived neurotrophic factor [BDNF], nerve growth factor [NGF], and vascular endothelial growth factor) increased at the 24-h period after VEx in the FC and RSC, but not OC. Two-weeks following VEx, BDNF remained elevated in both FC and RSC, whereas NGF remained elevated in only the FC. Interestingly, VEx only recovered cognitive performance in amnestic rats when there was an additional 2-wk adaptation period after VEx. Given this unique temporal profile, Experiment 2 examined the cortical cytogenetic responses in all three cortical regions following a 2-wk adaptation period after VEx. In healthy (PF) rats, VEx increased the survival of progenitor cells in both the FC and RSC, but only increased oligodendrocyte precursor cells (OLPs) in the FC. Furthermore, VEx had a selective effect of only recovering OLPs in the FC in PTD rats. These data reveal the therapeutic potential of exercise to restore cortical plasticity in the amnestic brain, and that the FC is one of the most responsive cortical regions to VEx. PMID:24215977

  9. Discriminative stimulus effects of the GABAB receptor-positive modulator rac-BHFF: comparison with GABAB receptor agonists and drugs of abuse.

    PubMed

    Koek, Wouter; Cheng, Kejun; Rice, Kenner C

    2013-03-01

    GABA(B) receptor-positive modulators are thought to have advantages as potential medications for anxiety, depression, and drug addiction. They may have fewer side effects than GABA(B) receptor agonists, because selective enhancement of activated receptors could have effects different from nonselective activation of all receptors. To examine this, pigeons were trained to discriminate the GABA(B) receptor-positive modulator (R,S)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3H-benzofuran-2-one (rac-BHFF) from its vehicle. The discriminative stimulus effects of rac-BHFF were not mimicked by the GABA(B) receptor agonists baclofen and γ-hydroxybutyrate (GHB), not by diazepam, and not by alcohol, cocaine, and nicotine, whose self-administration has been reported to be attenuated by GABA(B) receptor-positive modulators. The discriminative stimulus effects of rac-BHFF were not antagonized by the GABA(B) receptor antagonist 3-aminopropyl (diethoxymethyl)phosphinic acid (CGP35348) but were attenuated by the less efficacious GABA(B) receptor-positive modulator 2,6-di-tert-butyl-4-(3-hydroxy-2,2-dimethylpropyl)phenol (CGP7930), suggesting the possibility that rac-BHFF produces its discriminative stimulus effects by directly activating GABA(B2) subunits of GABA(B) receptors. At a dose 10-fold lower than the training dose, rac-BHFF enhanced the discriminative stimulus effects of baclofen, but not of GHB. This study provides evidence that the effects of GABA(B) receptor-positive modulators are not identical to those of GABA(B) receptor agonists. In addition, the results suggest that positive modulation of GABA(B) receptors does not produce discriminative stimulus effects similar to those of benzodiazepines, alcohol, cocaine, and nicotine. Finally, the finding that rac-BHFF enhanced effects of baclofen but not of GHB is consistent with converging evidence that the populations of GABA(B) receptors mediating the effects of baclofen and GHB are not identical. PMID:23275067

  10. The stress oncoprotein LEDGF/p75 interacts with the methyl CpG binding protein MeCP2 and influences its transcriptional activity.

    PubMed

    Leoh, Lai Sum; van Heertum, Bart; De Rijck, Jan; Filippova, Maria; Rios-Colon, Leslimar; Basu, Anamika; Martinez, Shannalee R; Tungteakkhun, Sandy S; Filippov, Valeri; Christ, Frauke; De Leon, Marino; Debyser, Zeger; Casiano, Carlos A

    2012-03-01

    The lens epithelium-derived growth factor p75 (LEDGF/p75) is a transcription coactivator that promotes resistance to oxidative stress- and chemotherapy-induced cell death. LEDGF/p75 is also known as the dense fine speckles autoantigen of 70 kDa (DFS70) and has been implicated in cancer, HIV-AIDS, autoimmunity, and inflammation. To gain insights into mechanisms by which LEDGF/p75 protects cancer cells against stress, we initiated an analysis of its interactions with other transcription factors and the influence of these interactions on stress gene activation. We report here that both LEDGF/p75 and its short splice variant LEDGF/p52 interact with MeCP2, a methylation-associated transcriptional modulator, in vitro and in various human cancer cells. These interactions were established by several complementary approaches: transcription factor protein arrays, pull-down and AlphaScreen assays, coimmunoprecipitation, and nuclear colocalization by confocal microscopy. MeCP2 was found to interact with the N-terminal region shared by LEDGF/p75 and p52, particularly with the PWWP-CR1 domain. Like LEDGF/p75, MeCP2 bound to and transactivated the Hsp27 promoter (Hsp27pr). LEDGF/p75 modestly enhanced MeCP2-induced Hsp27pr transactivation in U2OS osteosarcoma cells, whereas this effect was more pronounced in PC3 prostate cancer cells. LEDGF/p52 repressed Hsp27pr activity in U2OS cells. Interestingly, siRNA-induced silencing of LEDGF/p75 in U2OS cells dramatically elevated MeCP2-mediated Hsp27pr transactivation, whereas this effect was less pronounced in PC3 cells depleted of LEDGF/p75. These results suggest that the LEDGF/p75-MeCP2 interaction differentially influences Hsp27pr activation depending on the cellular and molecular context. These findings are of significance in understanding the contribution of this interaction to the activation of stress survival genes. PMID:22275515

  11. LEDGF/p75 Overexpression Attenuates Oxidative Stress-Induced Necrosis and Upregulates the Oxidoreductase ERP57/PDIA3/GRP58 in Prostate Cancer

    PubMed Central

    Basu, Anamika; Cajigas-Du Ross, Christina K.; Rios-Colon, Leslimar; Mediavilla-Varela, Melanie; Daniels-Wells, Tracy R.; Leoh, Lai Sum; Rojas, Heather; Banerjee, Hiya; Martinez, Shannalee R.; Acevedo-Martinez, Stephanny; Casiano, Carlos A.

    2016-01-01

    Prostate cancer (PCa) mortality is driven by highly aggressive tumors characterized by metastasis and resistance to therapy, and this aggressiveness is mediated by numerous factors, including activation of stress survival pathways in the pro-inflammatory tumor microenvironment. LEDGF/p75, also known as the DFS70 autoantigen, is a stress transcription co-activator implicated in cancer, HIV-AIDS, and autoimmunity. This protein is targeted by autoantibodies in certain subsets of patients with PCa and inflammatory conditions, as well as in some apparently healthy individuals. LEDGF/p75 is overexpressed in PCa and other cancers, and promotes resistance to chemotherapy-induced cell death via the transactivation of survival proteins. We report in this study that overexpression of LEDGF/p75 in PCa cells attenuates oxidative stress-induced necrosis but not staurosporine-induced apoptosis. This finding was consistent with the observation that while LEDGF/p75 was robustly cleaved in apoptotic cells into a p65 fragment that lacks stress survival activity, it remained relatively intact in necrotic cells. Overexpression of LEDGF/p75 in PCa cells led to the upregulation of transcript and protein levels of the thiol-oxidoreductase ERp57 (also known as GRP58 and PDIA3), whereas its depletion led to ERp57 transcript downregulation. Chromatin immunoprecipitation and transcription reporter assays showed LEDGF/p75 binding to and transactivating the ERp57 promoter, respectively. Immunohistochemical analysis revealed significantly elevated co-expression of these two proteins in clinical prostate tumor tissues. Our results suggest that LEDGF/p75 is not an inhibitor of apoptosis but rather an antagonist of oxidative stress-induced necrosis, and that its overexpression in PCa leads to ERp57 upregulation. These findings are of significance in clarifying the role of the LEDGF/p75 stress survival pathway in PCa. PMID:26771192

  12. The effects of neurotrophin-3 and brain-derived neurotrophic factor on cerebellar granule cell movement and neurite extension in vitro.

    PubMed

    Tanaka, S; Sekino, Y; Shirao, T

    2000-01-01

    Migration of the granule cells is a major stage of cerebellar maturation. Granule cells express neurotrophins and their receptors; however, their role in cell migration has not been defined. In this study we investigated the effects of exogenous neurotrophins on the movement and neurite extension of granule cells from glial-free cerebellar cell reaggregates in vitro. Our results provide direct evidence that neurotrophin-3 and brain-derived neurotrophic factor differentially affect the granule cells. Neurotrophin-3 significantly affected granule cell movements by decreasing the migration index (the ratio of the number of cells that moved further than half the neurite length) and the speed of cell soma movement, but did not affect neurite length or growth cone migration. In contrast, brain-derived neurotrophic factor and neurotrophin-4 acted on growing neurites and growth cones by significantly increasing neurite length and the speed of growth cone migration, but had no effect either on the migration index or on the speed of the cell soma movement. The results suggest that neurotrophins differentially affect neurite extension and the movements of cerebellar granule cells. PMID:10842017

  13. Sodium Phenylbutyrate Enhances Astrocytic Neurotrophin Synthesis via Protein Kinase C (PKC)-mediated Activation of cAMP-response Element-binding Protein (CREB)

    PubMed Central

    Corbett, Grant T.; Roy, Avik; Pahan, Kalipada

    2013-01-01

    Neurotrophins, such as brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3), are believed to be genuine molecular mediators of neuronal growth and homeostatic synapse activity. However, levels of these neurotrophic factors decrease in different brain regions of patients with Alzheimer disease (AD). Induction of astrocytic neurotrophin synthesis is a poorly understood phenomenon but represents a plausible therapeutic target because neuronal neurotrophin production is aberrant in AD and other neurodegenerative diseases. Here, we delineate that sodium phenylbutyrate (NaPB), a Food and Drug Administration-approved oral medication for hyperammonemia, induces astrocytic BDNF and NT-3 expression via the protein kinase C (PKC)-cAMP-response element-binding protein (CREB) pathway. NaPB treatment increased the direct association between PKC and CREB followed by phosphorylation of CREB (Ser133) and induction of DNA binding and transcriptional activation of CREB. Up-regulation of markers for synaptic function and plasticity in cultured hippocampal neurons by NaPB-treated astroglial supernatants and its abrogation by anti-TrkB blocking antibody suggest that NaPB-induced astroglial neurotrophins are functionally active. Moreover, oral administration of NaPB increased the levels of BDNF and NT-3 in the CNS and improved spatial learning and memory in a mouse model of AD. Our results highlight a novel neurotrophic property of NaPB that may be used to augment neurotrophins in the CNS and improve synaptic function in disease states such as AD. PMID:23404502

  14. BDNF-induced nitric oxide signals in cultured rat hippocampal neurons: time course, mechanism of generation, and effect on neurotrophin secretion

    PubMed Central

    Kolarow, Richard; Kuhlmann, Christoph R. W.; Munsch, Thomas; Zehendner, Christoph; Brigadski, Tanja; Luhmann, Heiko J.; Lessmann, Volkmar

    2014-01-01

    BDNF and nitric oxide signaling both contribute to plasticity at glutamatergic synapses. However, the role of combined signaling of both pathways at the same synapse is largely unknown. Using NO imaging with diaminofluoresceine in cultured hippocampal neurons we analyzed the time course of neurotrophin-induced NO signals. Application of exogenous BDNF, NT-4, and NT-3 (but not NGF) induced NO signals in the soma and in proximal dendrites of hippocampal neurons that were sensitive to NO synthase activity, TrkB signaling, and intracellular calcium elevation. The effect of NO signaling on neurotrophin secretion was analyzed in BDNF-GFP, and NT-3-GFP transfected hippocampal neurons. Exogenous application of the NO donor sodium-nitroprusside markedly inhibited neurotrophin secretion. However, endogenously generated NO in response to depolarization and neurotrophin stimulation, both did not result in a negative feedback on neurotrophin secretion. These results suggest that a negative feedback of NO signaling on synaptic secretion of neurotrophins operates only at high intracellular levels of nitric oxide that are under physiological conditions not reached by depolarization or BDNF signaling. PMID:25426021

  15. Seasonal changes in expression of nerve growth factor and its receptors TrkA and p75 in the ovary of wild ground squirrel (Citellus dauricus Brandt)

    PubMed Central

    2014-01-01

    The aim of this study was to investigate the presence of nerve growth factor (NGF) and its receptors tyrosine kinase A (TrkA) and p75 in the ovaries of the wild ground squirrels during the breeding and nonbreeding seasons. In the breeding period, NGF, TrkA and p75 were immunolocalized in granulosa cells, thecal cells, interstitial cells and luteal cells whereas in the nonbreeding period, both of them were detected only in granulosa cells, thecal cells and interstitial cells. Stronger immunostaining of NGF, TrkA and p75 were observed in granulosa cells, thecal cells and interstitial cells in the breeding season compared to the nonbreeding season. Corresponding for the immunohistochemical results, immunoreactivities of NGF and its two receptors were greater in the ovaries of the breeding season then decreased to a relatively low level in the nonbreeding season. The mean mRNA levels of NGF, TrkA and p75 were significantly higher in the breeding season than in the nonbreeding season. In addition, plasma gonadotropins, estradiol-17β and progesterone concentrations were significantly higher in the breeding season than in the nonbreeding season, suggesting that the expression patterns of NGF, and TrkA and p75 were correlated with changes in plasma gonadotropins, estradiol-17β and progesterone concentrations. These results indicated that NGF and its receptors, TrkA and p75 may be involved in the regulation of seasonal changes in the ovarian functions of the wild ground squirrel. PMID:24405743

  16. Seasonal changes in expression of nerve growth factor and its receptors TrkA and p75 in the ovary of wild ground squirrel (Citellus dauricus Brandt).

    PubMed

    Li, Ben; Sheng, Xia; Bao, Lihong; Huang, Shiyang; Li, Qinglin; Liu, Yuning; Han, Yingying; Watanabe, Gen; Taya, Kazuyoshi; Weng, Qiang

    2014-01-01

    The aim of this study was to investigate the presence of nerve growth factor (NGF) and its receptors tyrosine kinase A (TrkA) and p75 in the ovaries of the wild ground squirrels during the breeding and nonbreeding seasons. In the breeding period, NGF, TrkA and p75 were immunolocalized in granulosa cells, thecal cells, interstitial cells and luteal cells whereas in the nonbreeding period, both of them were detected only in granulosa cells, thecal cells and interstitial cells. Stronger immunostaining of NGF, TrkA and p75 were observed in granulosa cells, thecal cells and interstitial cells in the breeding season compared to the nonbreeding season. Corresponding for the immunohistochemical results, immunoreactivities of NGF and its two receptors were greater in the ovaries of the breeding season then decreased to a relatively low level in the nonbreeding season. The mean mRNA levels of NGF, TrkA and p75 were significantly higher in the breeding season than in the nonbreeding season. In addition, plasma gonadotropins, estradiol-17β and progesterone concentrations were significantly higher in the breeding season than in the nonbreeding season, suggesting that the expression patterns of NGF, and TrkA and p75 were correlated with changes in plasma gonadotropins, estradiol-17β and progesterone concentrations. These results indicated that NGF and its receptors, TrkA and p75 may be involved in the regulation of seasonal changes in the ovarian functions of the wild ground squirrel. PMID:24405743

  17. LEDGIN-mediated Inhibition of Integrase-LEDGF/p75 Interaction Reduces Reactivation of Residual Latent HIV.

    PubMed

    Vranckx, Lenard S; Demeulemeester, Jonas; Saleh, Suha; Boll, Annegret; Vansant, Gerlinde; Schrijvers, Rik; Weydert, Caroline; Battivelli, Emilie; Verdin, Eric; Cereseto, Anna; Christ, Frauke; Gijsbers, Rik; Debyser, Zeger

    2016-06-01

    Persistence of latent, replication-competent Human Immunodeficiency Virus type 1 (HIV-1) provirus is the main impediment towards a cure for HIV/AIDS (Acquired Immune Deficiency Syndrome). Therefore, different therapeutic strategies to eliminate the viral reservoirs are currently being explored. We here propose a novel strategy to reduce the replicating HIV reservoir during primary HIV infection by means of drug-induced retargeting of HIV integration. A novel class of integration inhibitors, referred to as LEDGINs, inhibit the interaction between HIV integrase and the LEDGF/p75 host cofactor, the main determinant of lentiviral integration site selection. We show for the first time that LEDGF/p75 depletion hampers HIV-1 reactivation in cell culture. Next we demonstrate that LEDGINs relocate and retarget HIV integration resulting in a HIV reservoir that is refractory to reactivation by different latency-reversing agents. Taken together, these results support the potential of integrase inhibitors that modulate integration site targeting to reduce the likeliness of viral rebound. PMID:27428435

  18. [The Role of Neurotrophins and Neurexins Genes in the Risk of Paranoid Schizophrenia in Russians and Tatars].

    PubMed

    Gareeva, A E; Traks, T; Koks, S; Khusnutdinova, E K

    2015-07-01

    Schizophrenia affects about 1% of the population. Its etiology is not fully understood. Environmental conditions certainly contribute to the development of schizophrenia, but the determining factor is genetic predisposition: the coefficient of heritability of schizophrenia is about 80%, which is typical for the most highly heritable multifactorial diseases. Polymorphic loci of genes of enzymes and receptors involved in the processes of neuroprotection and neurotrophia play significant role in the development of this disease. In this paper we investigated 48 polymorphic variants of genes of the neurotrophins and neurexins family (BDNF, NTRK2, NTRK3, NGF, NXPH1, and NRXN1) in Russian and Tatar cases and in a control group living in the Republic of Bashkortostan. The results of this study confirm the important role of neurotrophin and neurexin genes in paranoid schizophrenia development. PMID:26410934

  19. Nerve growth factor and neurotrophin-3 mediate survival of pulmonary plasma cells during the allergic airway inflammation.

    PubMed

    Abram, Melanie; Wegmann, Michael; Fokuhl, Verena; Sonar, Sanchaita; Luger, Elke Olga; Kerzel, Sebastian; Radbruch, Andreas; Renz, Harald; Zemlin, Michael

    2009-04-15

    Allergen-specific Abs play a pivotal role in the induction and maintenance of allergic airway inflammation. During secondary immune responses, plasma cell survival and Ab production is mediated by extrinsic factors provided by the local environment (survival niches). It is unknown whether neurotrophins, a characteristic marker of allergic airway inflammation, influence plasma cell survival in the lung. Using a mouse model of allergic asthma, we found that plasma cells from the lung and spleen are distinct subpopulations exhibiting differential expression patterns of neurotrophins and their receptors (Trks). In vitro, the nerve growth factor (NGF) and neurotrophin-3 (NT3) led to a dose-dependent increase in viability of isolated pulmonary plasma cells due to up-regulation of the antiapoptotic Bcl2 pathway. In parallel, the expression of transcription factors that stimulate the production of immunoglobulins (X-box binding protein 1 and NF-kappaB subunit RelA) was enhanced in plasma cells treated with NGF and NT3. These findings were supported in vivo. When the NGF pathway was blocked by intranasal application of a selective TrkA inhibitor, sensitized mice showed reduced numbers of pulmonary plasma cells and developed lower levels of allergen-specific and total serum IgE in response to OVA inhalation. This suggests that in the allergic airway inflammation, NGF/TrkA-mediated pulmonary IgE production contributes significantly to serum-IgE levels. We conclude that the neurotrophins NGF and NT3 act as survival factors for pulmonary plasma cells and thus are important regulators of the local Ab production in the allergic airway disease. PMID:19342646

  20. Effects of the GABAB Receptor-Positive Modulators CGP7930 and rac-BHFF in Baclofen- and γ-Hydroxybutyrate-Discriminating Pigeons

    PubMed Central

    France, Charles P.; Cheng, Kejun; Rice, Kenner C.

    2012-01-01

    In vivo effects of GABAB receptor-positive modulators suggest them to have therapeutic potential to treat central nervous system disorders such as anxiety and drug abuse. Although these effects are thought to be mediated by positive modulation of GABAB receptors, such modulation has been examined primarily in vitro. This study further examined the in vivo properties of the GABAB receptor-positive modulators 2,6-di-tert-butyl-4-(3-hydroxy-2,2-dimethylpropyl) phenol (CGP7930) and (R,S)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3H-benzofuran-2-one (rac-BHFF). In pigeons discriminating baclofen from saline, γ-hydroxybutyrate (GHB) produced 100% baclofen-appropriate responding, and the GABAB antagonist 3-aminopropyl(dimethoxymethyl) phosphinic acid (CGP35348) blocked the effects of both drugs. CGP7930 and rac-BHFF produced at most 41 and 74% baclofen-appropriate responding, respectively, and enhanced the discriminative stimulus effects of baclofen, but not of GHB. In pigeons discriminating GHB from saline, CGP7930 and rac-BHFF produced at most 1 and 49% GHB-appropriate responding, respectively, and enhanced the effects of baclofen, but not of GHB. Enhancement of the discriminative stimulus effects of baclofen by rac-BHFF and CGP7930 is further evidence of their effectiveness as GABAB receptor-positive modulators in vivo. Furthermore, lack of complete substitution of the positive modulators rac-BHFF and CGP7930 for baclofen and GHB suggests that their discriminative stimulus effects differ from those of GABAB receptor agonists. Finally, together with converging evidence that the GABAB receptor populations mediating the effects of baclofen and GHB are not identical, the present findings suggest that these populations differ in their susceptibility to positive modulatory effects. Such differences could allow for more selective therapeutic targeting of the GABAB system. PMID:22319197

  1. Effects of the GABAB receptor-positive modulators CGP7930 and rac-BHFF in baclofen- and γ-hydroxybutyrate-discriminating pigeons.

    PubMed

    Koek, Wouter; France, Charles P; Cheng, Kejun; Rice, Kenner C

    2012-05-01

    In vivo effects of GABA(B) receptor-positive modulators suggest them to have therapeutic potential to treat central nervous system disorders such as anxiety and drug abuse. Although these effects are thought to be mediated by positive modulation of GABA(B) receptors, such modulation has been examined primarily in vitro. This study further examined the in vivo properties of the GABA(B) receptor-positive modulators 2,6-di-tert-butyl-4-(3-hydroxy-2,2-dimethylpropyl) phenol (CGP7930) and (R,S)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3H-benzofuran-2-one (rac-BHFF). In pigeons discriminating baclofen from saline, γ-hydroxybutyrate (GHB) produced 100% baclofen-appropriate responding, and the GABA(B) antagonist 3-aminopropyl(dimethoxymethyl) phosphinic acid (CGP35348) blocked the effects of both drugs. CGP7930 and rac-BHFF produced at most 41 and 74% baclofen-appropriate responding, respectively, and enhanced the discriminative stimulus effects of baclofen, but not of GHB. In pigeons discriminating GHB from saline, CGP7930 and rac-BHFF produced at most 1 and 49% GHB-appropriate responding, respectively, and enhanced the effects of baclofen, but not of GHB. Enhancement of the discriminative stimulus effects of baclofen by rac-BHFF and CGP7930 is further evidence of their effectiveness as GABA(B) receptor-positive modulators in vivo. Furthermore, lack of complete substitution of the positive modulators rac-BHFF and CGP7930 for baclofen and GHB suggests that their discriminative stimulus effects differ from those of GABA(B) receptor agonists. Finally, together with converging evidence that the GABA(B) receptor populations mediating the effects of baclofen and GHB are not identical, the present findings suggest that these populations differ in their susceptibility to positive modulatory effects. Such differences could allow for more selective therapeutic targeting of the GABA(B) system. PMID:22319197

  2. Identification of the HeLa tumor-associated antigen, p75/150, as intestinal alkaline phosphatase and evidence for its transcriptional regulation.

    PubMed Central

    Latham, K M; Stanbridge, E J

    1990-01-01

    Prior studies identified a cell-surface antigen, p75/150, that exclusively associated with the tumorigenic phenotype of the HeLa parent and the tumorigenic phenotype of the HeLa parent and the tumorigenic segregants of suppressed, nontumorigenic HeLa x human fibroblast cell hybrids. Candidate p75/150 cDNA clones were isolated from a D98/AH.2 (HeLa) cDNA library using oligonucleotide probes derived from p75/150 partial peptide sequence data. A data base search revealed close similarity of p75/150 with intestinal alkaline phosphatase (IAP) [Berger, J., Garantini, E., Hua, J. C. & Udenfriend, S. (1987) Proc. Natl. Acad. Sci. USA 84, 695-698]. We demonstrate that p75/150 is identical to HeLa IAP by the following criteria: (i) 47/49 amino acid identity of p75 peptide sequence with IAP, (ii) restriction maps for the p75/150 candidate cDNA clone and IAP are identical, (iii) partial DNA sequence analysis of p75/150 candidate cDNA clones revealed complete nucleotide identity with IAP, except for a single nucleotide substitution in the 5' untranslated region, (iv) transfection of a p75/150 cDNA expression vector into the nontumorigenic hybrid, CGL1, yielded p75/150 antibody-positive transfectants that also expressed partially heat-resistant alkaline phosphatase activity. Northern blot analysis demonstrated that high levels of HeLa IAP mRNA were expressed in D98/AH.2 and the tumorigenic segregant CGL4; however, no mRNA was detected in CGL1. Nuclear run-on analyses indicate that HeLa IAP mRNA expression in the HeLa x fibroblast hybrids is regulated at the level of transcription initiation. Furthermore, evidence is discussed supporting the involvement of a chromosome 11 tumor suppressor locus in the regulation of HeLa IAP gene expression. Images PMID:2304898

  3. Identification of Potentially Neuroprotective Genes Upregulated by Neurotrophin Treatment of CA3 Neurons in the Injured Brain

    PubMed Central

    Malik, Saafan Z.; Motamedi, Shahab; Royo, Nicolas C.; LeBold, David

    2011-01-01

    Abstract Specific neurotrophic factors mediate histological and/or functional improvement in animal models of traumatic brain injury (TBI). In previous work, several lines of evidence indicated that the mammalian neurotrophin NT-4/5 is neuroprotective for hippocampal CA3 pyramidal neurons after experimental TBI. We hypothesized that NT-4/5 neuroprotection is mediated by changes in the expression of specific sets of genes, and that NT-4/5-regulated genes are potential therapeutic targets for blocking delayed neuronal death after TBI. In this study, we performed transcription profiling analysis of CA3 neurons to identify genes regulated by lateral fluid percussion injury, or by treatment with the trkB ligands NT-4/5 or brain-derived neurotrophic factor (BDNF). The results indicate extensive overlap between genes upregulated by neurotrophins and genes upregulated by injury, suggesting that the mechanism behind neurotrophin neuroprotection may mimic the brain's endogenous protective response. A subset of genes selected for further study in vitro exhibited neuroprotection against glutamate excitotoxicity. The neuroprotective genes identified in this study were upregulated at 30 h post-injury, and are thus expected to act during a clinically useful time frame of hours to days after injury. Modulation of these factors and pathways by genetic manipulation or small molecules may confer hippocampal neuroprotection in vivo in preclinical models of TBI. PMID:21083427

  4. Brain-derived neurotrophic factor and neurotrophin receptors modulate glutamate-induced phase shifts of the suprachiasmatic nucleus

    PubMed Central

    Michel, S.; Clark, J. P.; Ding, J. M.; Colwell, C. S.

    2008-01-01

    Light information reaches the suprachiasmatic nucleus (SCN) through a subpopulation of retinal ganglion cells. Previous work raised the possibility that brain-derived neurotrophic factor (BDNF) and its high-affinity tropomyosin-related receptor kinase may be important as modulators of this excitatory input into the SCN. In order to test this possibility, we used whole-cell patch-clamp methods to measure spontaneous excitatory currents in mouse SCN neurons. We found that the amplitude and frequency of these currents were increased by BDNF and decreased by the neurotrophin receptor inhibitor K252a. The neurotrophin also increased the magnitude of currents evoked by application of N-methyl-D-aspartate and amino-methyl proprionic acid. Next, we measured the rhythms in action potential discharge from the SCN brain slice preparation. We found that application of K252a dramatically reduced the magnitude of phase shifts of the electrical activity rhythm generated by the application of glutamate. By itself, BDNF caused phase shifts that resembled those produced by glutamate and were blocked by K252a. The results demonstrate that BDNF and neurotrophin receptors can enhance glutamatergic synaptic transmission within a subset of SCN neurons and potentiate glutamate-induced phase shifts of the circadian rhythm of neural activity in the SCN. PMID:16930436

  5. Immunohistochemical profile of neurotrophins and MIB-1 in jugulotympanic paragangliomas: prognostic value and review of the literature.

    PubMed

    Artico, M; De Vincentiis, M; Ionta, B; Bianchi, E; Bosco, S; Onteleone, M; Fumagalli, L; Magliulo, G

    2012-01-01

    Jugulo-tympanic paragangliomas are the most common primary neoplasm of the middle ear, but little is still known about the histological features differentiating the benign and malignant forms. We investigated, with an immunohistochemical procedure, the expression of neurotrophins with their receptors, in fifteen samples of paragangliomas, and MIB-1 in order to consider them as prognostic factors of malignancy. We observed a general positivity for NGF - TrKA - NT4 - TrKC in the cytoplasm, and a strong expression for BDNF in the extracellular space. MIB-1 was moderate in the nucleus of neoplastic cells, weak in the cytoplasm and totally absent in the extracellular space. The comparison between the clinical recurrences and the rate of cytoplasmatic neurotrophins showed strong immunoreactivity in recurrent patients. It should be emphasized that 2 of the 3 recurrences had a wider distribution of the neutrophins, leading to hypothesize the involvement of these substances in the cell proliferation of glomus tumors. Malignant forms of these rare glomus tumors cannot be clearly identified using MIB-1 as a prognostic marker, although we can affirm that neurotrophins and their receptors can be considered as a panel of potential diagnostic markers to monitor the development of such malignancies. Although the small number of patients does not allow definitive conclusions to be made, our findings showed a possible trend towards significance which requires a more powerful study to evaluate this further. PMID:22507331

  6. NGF Modulates trkANGFR/p75NTR in αSMA-Expressing Conjunctival Fibroblasts from Human Ocular Cicatricial Pemphigoid (OCP)

    PubMed Central

    Di Zazzo, Antonio; Sgrulletta, Roberto; Cortes, Magdalena; Normando, Eduardo Maria; Lambiase, Alessandro; Bonini, Stefano

    2015-01-01

    Objective In a previous study, we reported the upregulation of Nerve Growth Factor (NGF) and trkANGFR expression in Ocular Cicatricial Pemphigoid (OCP), an inflammatory and remodeling eye disease. Herein, we hypothesize a potential NGF-driven mechanism on fibroblasts (FBs) during OCP remodeling events. To verify, human derived OCP-FBs were isolated and characterized either at baseline or after NGF exposure. Materials and Methods Conjunctival biopsies were obtained from 7 patients having OCP and 6 control subjects (cataract surgery). Both conjunctivas and primary FB cultures were characterised for αSMA, NGF and trkANGFR/p75NTR expression. Subcultures were exposed to NGF and evaluated for αSMA, NGF, trkANGFR/p75NTR expression as well as TGFβ1/IL4 release. For analysis, early and advanced subgroups were defined according to clinical parameters. Results OCP-conjunctivas showed αSMA-expressing FBs and high NGF levels. Advanced OCP-FBs showed higher αSMA expression associated with higher p75NTR and lower trkANGFR expression, as compared to early counterparts. αSMA expression was in keeping with disease severity and correlated to p75NTR. NGF exposure did not affect trkANGFR levels in early OCP-FBs while decreased both αSMA/p75NTR expression and TGFβ1/IL4 release. These effects were not observed in advanced OCP-FBs. Conclusions Taken together, these data are suggestive for a NGF/p75NTR task in the potential modulation of OCP fibrosis and encourages further studies to fully understand the underlying mechanism occurring in fibrosis. NGF/p75NTR might be viewed as a potential therapeutic target. PMID:26569118

  7. A Case of Disease Improvement after Treatment with Everolimus plus Exemestane in a Patient with Hormone Receptor-Positive Metastatic Breast Cancer with Bone Metastases

    PubMed Central

    Beck, J. Thaddeus; Mantooth, Ryan

    2015-01-01

    Breast cancer is one of the most frequently diagnosed cancers and a leading cause of death in women worldwide. Despite significant advances in the treatment of hormone receptor-positive breast cancer, tumor metastasis occurs frequently and is associated with poor long-term prognosis. The mammalian target of rapamycin (mTOR) pathway plays a central role in cancer cell growth, proliferation, and resistance to endocrine therapies. Therefore, mTOR inhibitors such as everolimus in combination with nonsteroidal aromatase inhibitors might reverse endocrine resistance and improve clinical outcomes in patients. Here, we report on a case of infiltrating lobular carcinoma of the breast with metastases to the bone. Histopathologic analysis showed that the patient was estrogen and progesterone receptor positive and human epidermal growth factor-2 negative. This case represents the clinical spectrum of complications caused by metastasis: the patient experienced a considerable amount of skeletal-related complications, had previously received chemotherapy, and experienced disease progression while taking nonsteroidal aromatase inhibitors. After treatment with oral everolimus 10 mg daily plus oral exemestane 25 mg daily, the patient's disease was ameliorated. Combination therapy was well tolerated, with minimal adverse effects that were manageable with concomitant medications. Although further analyses in larger populations are necessary, the addition of everolimus to exemestane might provide an effective new treatment option for patients with bone metastasis. PMID:25848360

  8. Investigation of the effect of low-velocity impacts on P75/934 graphite/epoxy composites. Technical report

    SciTech Connect

    Schurr, J.N.; Quinn, M.T.; Hawkins, G.F.

    1991-04-01

    The low velocity impact testing of the P75/934 laminate plates revealed that this graphite/epoxy composite system is damaged very easily by impact. Impact energies to initiate damage as low as 6 ft-lb per inch thickness of composite were measured in drop-weight-type impact tests with edge supported, clamped specimens. Nondestructive evaluation (NDE) techniques, in particular, ultrasonic C-scan and dye enhanced X-ray radiography, confirmed that the damaged area increased with increased impact energy. The surface damage to the composite was detected visually only upon close inspection. Another promising NDE technique that was used to detect the presence of damage was thermal acoustic emission testing. Further study of this technique would be worthwhile pursuing.

  9. Intervertebral disc, sensory nerves and neurotrophins: who is who in discogenic pain?

    PubMed Central

    García-Cosamalón, José; del Valle, Miguel E; Calavia, Marta G; García-Suárez, Olivia; López-Muñiz, Alfonso; Otero, Jesús; Vega, José A

    2010-01-01

    The normal intervertebral disc (IVD) is a poorly innervated organ supplied only by sensory (mainly nociceptive) and postganglionic sympathetic (vasomotor efferents) nerve fibers. Interestingly, upon degeneration, the IVD becomes densely innervated even in regions that in normal conditions lack innervation. This increased innervation has been associated with pain of IVD origin. The mechanisms responsible for nerve growth and hyperinnervation of pathological IVDs have not been fully elucidated. Among the molecules that are presumably involved in this process are some members of the family of neurotrophins (NTs), which are known to have both neurotrophic and neurotropic properties and regulate the density and distribution of nerve fibers in peripheral tissues. NTs and their receptors are expressed in healthy IVDs but much higher levels have been observed in pathological IVDs, thus suggesting a correlation between levels of expression of NTs and density of innervation in IVDs. In addition, NTs also play a role in inflammatory responses and pain transmission by increasing the expression of pain-related peptides and modulating synapses of nociceptive neurons at the spinal cord. This article reviews current knowledge about the innervation of IVDs, NTs and NT receptors, expression of NTs and their receptors in IVDs as well as in the sensory neurons innervating the IVDs, the proinflammatory role of NTs, NTs as nociception regulators, and the potential network of discogenic pain involving NTs. PMID:20456524

  10. Role of Neurotrophins in Recovery of Phrenic Motor Function Following Spinal Cord Injury

    PubMed Central

    Sieck, Gary C.; Mantilla, Carlos B.

    2009-01-01

    Many individuals who sustain a cervical spinal cord injury are unable to maintain adequate ventilation due to diaphragm muscle paralysis. These patients become dependent on mechanical ventilators and this situation is associated with ongoing problems with pulmonary clearance, infections, and lung injury leading to significant morbidity and reduced life expectancy. Therefore, functional recovery of rhythmic phrenic activity and the ability to generate expulsive forces would dramatically affect the quality of life of patients with cervical spinal cord injury. Neurotrophins are very promising in that they have been shown to play an important role in modulating functional neuroplasticity. Specifically, brain-derived neurotrophic factor (BDNF) acting via the tropomyosin-related kinase receptor type B (TrkB) has been implicated in neuroplasticity following spinal cord injury. Our central hypothesis is that functional recovery of rhythmic phrenic activity after cervical spinal cord injury is enhanced by an increase in BDNF/TrkB signaling in phrenic motoneurons, providing a novel therapeutic target for patients. PMID:19703592

  11. Modulation of cultured neural networks using neurotrophin release from hydrogel-coated microelectrode arrays

    NASA Astrophysics Data System (ADS)

    Jun, Sang Beom; Hynd, Matthew R.; Dowell-Mesfin, Natalie M.; Al-Kofahi, Yousef; Roysam, Badrinath; Shain, William; Kim, Sung June

    2008-06-01

    Polyacrylamide and poly(ethylene glycol) diacrylate hydrogels were synthesized and characterized for use as drug release and substrates for neuron cell culture. Protein release kinetics was determined by incorporating bovine serum albumin (BSA) into hydrogels during polymerization. To determine if hydrogel incorporation and release affect bioactivity, alkaline phosphatase was incorporated into hydrogels and a released enzyme activity determined using the fluorescence-based ELF-97 assay. Hydrogels were then used to deliver a brain-derived neurotrophic factor (BDNF) from hydrogels polymerized over planar microelectrode arrays (MEAs). Primary hippocampal neurons were cultured on both control and neurotrophin-containing hydrogel-coated MEAs. The effect of released BDNF on neurite length and process arborization was investigated using automated image analysis. An increased spontaneous activity as a response to the released BDNF was recorded from the neurons cultured on the top of hydrogel layers. These results demonstrate that proteins of biological interest can be incorporated into hydrogels to modulate development and function of cultured neural networks. These results also set the stage for development of hydrogel-coated neural prosthetic devices for local delivery of various biologically active molecules.

  12. The trk Tyrosine Protein Kinase Mediates the Mitogenic Properties of Nerve Growth Factor and Neurotrophin-3

    PubMed Central

    Cordon-Cardo, Carlos; Tapley, Peter; Jing, Shuqian; Nanduri, Venkata; O’Rourke, Edward; Lamballe, Fabienne; Kovary, Karla; Klein, Rüdiger; Jones, Kevin R.; Reichardt, Louis F.; Barbacid, Mariano

    2009-01-01

    Summary The product of the trk proto-oncogene encodes a receptor for nerve growth factor (NGF). Here we show that NGF is a powerful mitogen that can induce resting NIH 3T3 cells to enter S phase, grow in semisolid medium, and become morphologically transformed. These mitogenic effects are absolutely dependent on expression of gp140trk receptors, but do not require the presence of the previously described low affinity NGF receptor. gp140trk also serves as a receptor for the related factor neurotrophin-3 (NT-3), but not for brain-derived neurotrophic factor. Both NGF and NT-3 induce the rapid phosphorylation of gp140trk receptors and the transient expression of c-Fos proteins. However, NT-3 appears to elicit more limited mitogenic responses than NGF. These results indicate that the product of the trk proto-oncogene is sufficient to mediate signal transduction processes induced by NGF and NT-3, at least in proliferating cells. PMID:1649007

  13. Pre-reproductive maternal enrichment influences offspring developmental trajectories: motor behavior and neurotrophin expression

    PubMed Central

    Caporali, Paola; Cutuli, Debora; Gelfo, Francesca; Laricchiuta, Daniela; Foti, Francesca; De Bartolo, Paola; Mancini, Laura; Angelucci, Francesco; Petrosini, Laura

    2014-01-01

    Environmental enrichment is usually applied immediately after weaning or in adulthood, with strong effects on CNS anatomy and behavior. To examine the hypothesis that a pre-reproductive environmental enrichment of females could affect the motor development of their offspring, female rats were reared in an enriched environment from weaning to sexual maturity, while other female rats used as controls were reared under standard conditions. Following mating with standard-reared males, all females were housed individually. To evaluate the eventual transgenerational influence of positive pre-reproductive maternal experiences, postural and motor development of male pups was analyzed from birth to weaning. Moreover, expression of Brain Derived Neurotrophic Factor and Nerve Growth Factor in different brain regions was evaluated at birth and weaning. Pre-reproductive environmental enrichment of females affected the offspring motor development, as indicated by the earlier acquisition of complex motor abilities displayed by the pups of enriched females. The earlier acquisition of motor abilities was associated with enhanced neurotrophin levels in striatum and cerebellum. In conclusion, maternal positive experiences were transgenerationally transmitted, and influenced offspring phenotype at both behavioral and biochemical levels. PMID:24910599

  14. Effects of omega-3 supplementation on interleukin and neurotrophin levels in an animal model of schizophrenia.

    PubMed

    Zugno, Alexandra I; Canever, Lara; Mastella, Gustavo; Heylmann, Alexandra S; Oliveira, Mariana B; Steckert, Amanda V; Castro, Adalberto A; dal Pizzol, Felipe; Quevedo, João; Gama, Clarissa S

    2015-08-01

    New studies suggest that polyunsaturated fatty acids, such as omega-3, may reduce the symptoms of schizophrenia. The present study evaluated the preventive effect of omega-3 on interleukines (IL) and neurotrophin brain-derived neurotrophic factor (BDNF) levels in the brains of young rats subjected to a model of schizophrenia. Treatment was performed over 21 days, starting on the 30th day of rat's life. After 14 days of treatment with omega-3 or vehicle, a concomitant treatment with saline or ketamine (25 mg/kg) was started and maintained until the last day of the experiment. BDNF levels in the rat's prefrontal cortex were decreased at 1 h and 24 h after the last administration of ketamine, whereas the group administered with ketamine and omega-3 showed a decrease in BDNF levels only after 24 h. In contrast, both interventions induced similar responses in levels of IL-1β and IL6. These findings suggest that the similarity of IL-1β and IL6 levels in our experimental groups is due to the mechanism of action of ketamine on the immune system. More studies have to be carried out to explain this pathology. In conclusion, according to previous studies and considering the current study, we could suggest a prophylactic role of omega-3 against the outcome of symptoms associated with schizophrenia. PMID:26397829

  15. Sonic hedgehog and neurotrophin-3 increase oligodendrocyte numbers and myelination after spinal cord injury

    PubMed Central

    Goodman, Ashley G.; Kukushliev, Todor V.; Hassani, Donna M.; Cummings, Brian J.; Anderson, Aileen J.; Shea, Lonnie D.

    2014-01-01

    Spinal cord injury (SCI) results in loss of sensory and motor function below the level of injury and has limited available therapies. Multiple channel bridges have been investigated as a means to create a permissive environment for regeneration, with channels supporting axonal growth through the injury. Bridges support robust axon growth with myelination of the axons, and herein we investigated the cell types that are myelinating the axons and whether trophic factors can enhance myelination. Lentivirus encoding for neurotrophin-3 (NT3), sonic hedgehog (SHH) and the combination of these factors was delivered from bridges implanted into a lateral hemisection defect at T9/T10 in mice, and the response of endogenous progenitor cells within the spinal cord was investigated. Relative to control, the localized sustained expression of these factors significantly increased growth of regenerating axons into the bridge and enhanced axon myelination 8 weeks after injury. SHH decreased Sox2+ cells and increased Olig2+ cells, whereas NT3 alone or in combination with SHH enhanced GFAP+ and Olig2+ cells relative to control. For delivery of lentivirus encoding for either factor, we identified cells at various stages of differentiation along the oligodendrocyte lineage (e.g., O4+, GalC+). Expression of NT3 enhanced myelination primarily by infiltrating Schwann cells, whereas SHH over-expression substantially increased myelination by oligodendrocytes. Gene delivery represents a promising tool to direct activation and differentiation of endogenous progenitor cells for applications in regenerative medicine. PMID:24873988

  16. Deletion of a kinesin I motor unmasks a mechanism of homeostatic branching control by neurotrophin-3

    PubMed Central

    Auer, Thomas O; Xiao, Tong; Bercier, Valerie; Gebhardt, Christoph; Duroure, Karine; Concordet, Jean-Paul; Wyart, Claire; Suster, Maximiliano; Kawakami, Koichi; Wittbrodt, Joachim; Baier, Herwig; Del Bene, Filippo

    2015-01-01

    Development and function of highly polarized cells such as neurons depend on microtubule-associated intracellular transport, but little is known about contributions of specific molecular motors to the establishment of synaptic connections. In this study, we investigated the function of the Kinesin I heavy chain Kif5aa during retinotectal circuit formation in zebrafish. Targeted disruption of Kif5aa does not affect retinal ganglion cell differentiation, and retinal axons reach their topographically correct targets in the tectum, albeit with a delay. In vivo dynamic imaging showed that anterograde transport of mitochondria is impaired, as is synaptic transmission. Strikingly, disruption of presynaptic activity elicits upregulation of Neurotrophin-3 (Ntf3) in postsynaptic tectal cells. This in turn promotes exuberant branching of retinal axons by signaling through the TrkC receptor (Ntrk3). Thus, our study has uncovered an activity-dependent, retrograde signaling pathway that homeostatically controls axonal branching. DOI: http://dx.doi.org/10.7554/eLife.05061.001 PMID:26076409

  17. Neurotrophin receptor homolog (NRH1) proteins regulate mesoderm formation and apoptosis during early Xenopus development.

    PubMed

    Knapp, Dunja; Messenger, Nigel; Ahmed Rana, Amer; Smith, James C

    2006-12-15

    Recent experiments suggest that Xenopus Neurotrophin Receptor Homolog 1 (NRH1) proteins act through the planar cell polarity pathway to regulate convergent extension movements during gastrulation and neurulation. We show in this paper that NRH1 proteins are also required for the proper expression of mesodermally expressed genes such as Xbra and Chordin, and to a lesser extent, of Xwnt11. Loss of NRH1 function is followed, during gastrula and neurula stages, by a dramatic increase in apoptosis. Apoptosis is delayed by injection of Xbra RNA, suggesting that cell death is a consequence, at least in part, of the down-regulation of this gene, and it is also delayed by expression of activated forms of Rho, Rac and Cdc42. These small GTPases have previously been implicated in the planar cell polarity pathway in Xenopus and, in other systems, in the regulation of apoptosis. We conclude that the effects of NRH1 proteins include the regulation of mesodermal gene expression and that the disruption of gastrulation that is caused by their loss of function is a consequence of the down-regulation of Xbra and other genes, in addition to direct interference with the planar cell polarity pathway. The apoptosis observed in embryos lacking NRH1 function is not an indirect consequence of the disruption of gastrulation, and indeed it may contribute to the observed morphological defects. PMID:17055478

  18. Coseeded Schwann cells myelinate neurites from differentiated neural stem cells in neurotrophin-3-loaded PLGA carriers.

    PubMed

    Xiong, Yi; Zhu, Ji-Xiang; Fang, Zheng-Yu; Zeng, Cheng-Guang; Zhang, Chao; Qi, Guo-Long; Li, Man-Hui; Zhang, Wei; Quan, Da-Ping; Wan, Jun

    2012-01-01

    Biomaterials and neurotrophic factors represent promising guidance for neural repair. In this study, we combined poly-(lactic acid-co-glycolic acid) (PLGA) conduits and neurotrophin-3 (NT-3) to generate NT-3-loaded PLGA carriers in vitro. Bioactive NT-3 was released stably and constantly from PLGA conduits for up to 4 weeks. Neural stem cells (NSCs) and Schwann cells (SCs) were coseeded into an NT-releasing scaffold system and cultured for 14 days. Immunoreactivity against Map2 showed that most of the grafted cells (>80%) were differentiated toward neurons. Double-immunostaining for synaptogenesis and myelination revealed the formation of synaptic structures and myelin sheaths in the coculture, which was also observed under electron microscope. Furthermore, under depolarizing conditions, these synapses were excitable and capable of releasing synaptic vesicles labeled with FM1-43 or FM4-64. Taken together, coseeding NSCs and SCs into NT-3-loaded PLGA carriers increased the differentiation of NSCs into neurons, developed synaptic connections, exhibited synaptic activities, and myelination of neurites by the accompanying SCs. These results provide an experimental basis that supports transplantation of functional neural construction in spinal cord injury. PMID:22619535

  19. Local Delivery of Neurotrophin-3 and Anti-NogoA Promotes Repair After Spinal Cord Injury.

    PubMed

    Elliott Donaghue, Irja; Tator, Charles H; Shoichet, Molly S

    2016-05-01

    Tissue and functional repair after spinal cord injury (SCI) continue to elude researchers. Neurotrophin-3 (NT-3) and anti-NogoA have been shown to promote axonal regeneration in animal models of SCI; however, localized and sustained delivery to the central nervous system (CNS) remains a critical challenge for these and other macromolecular therapeutics. An injectable drug delivery system (DDS) has previously been developed, which can provide safe local delivery to the spinal cord. This DDS, composed of poly(lactic-co-glycolic acid) (PLGA) nanoparticles (nps) dispersed in a hyaluronan methylcellulose hydrogel, was adapted for the tunable bioactive delivery of NT-3 and anti-NogoA. Furthermore, the combined delivery of NT-3 and anti-NogoA from the DDS in an impact/compression model of SCI increases axon density and improves locomotor function. The benefits of this np/hydrogel DDS observed for NT-3 and anti-NogoA demonstrate the utility of the DDS as a local delivery strategy for protein therapeutics to the CNS. PMID:27056081

  20. Neurotrophin-mediated degradation of histone methyltransferase by S-nitrosylation cascade regulates neuronal differentiation

    PubMed Central

    Sen, Nilkantha; Snyder, Solomon H.

    2011-01-01

    Epigenetic regulation of histones mediates neurotrophin actions with histone acetylation enhancing cAMP response element-binding (CREB)-associated transcription elicited by brain-derived neurotrophic factor (BDNF) and nerve-growth factor (NGF). Roles for histone methylation in CREB's transcriptional activity have not been well characterized. We show that depletion of the histone methyltransferase suppressor of variegation 3–9 homolog 1 (SUV39H1) selectively augments BDNF- and NGF-mediated neurite outgrowth. SUV39H1 is the principal enzyme responsible for trimethylation of histone H3 at lysine 9, a molecular mark associated with transcriptional silencing. BDNF and NGF act via a signaling cascade wherein degradation of SUV39H1 down-regulates trimethylation of H3K9 in a nitric oxide-dependent pathway. BDNF activates neuronal NOS with the nitrosylated GAPDH/seven in absentia (Siah) homolog complex translocating to the nucleus. Degradation of SUV39H1 by Siah facilitates histone H3 on lysine 9 acetylation, CREB binding to DNA, enhanced expression of CREB-regulated genes and neurite outgrowth. PMID:22123949

  1. Macrophage migration inhibitory factor acts as a neurotrophin in the developing inner ear.

    PubMed

    Bank, Lisa M; Bianchi, Lynne M; Ebisu, Fumi; Lerman-Sinkoff, Dov; Smiley, Elizabeth C; Shen, Yu-chi; Ramamurthy, Poornapriya; Thompson, Deborah L; Roth, Therese M; Beck, Christine R; Flynn, Matthew; Teller, Ryan S; Feng, Luming; Llewellyn, G Nicholas; Holmes, Brandon; Sharples, Cyrrene; Coutinho-Budd, Jaeda; Linn, Stephanie A; Chervenak, Andrew P; Dolan, David F; Benson, Jennifer; Kanicki, Ariane; Martin, Catherine A; Altschuler, Richard; Koch, Alisa E; Koch, Alicia E; Jewett, Ethan M; Germiller, John A; Barald, Kate F

    2012-12-01

    This study is the first to demonstrate that macrophage migration inhibitory factor (MIF), an immune system 'inflammatory' cytokine that is released by the developing otocyst, plays a role in regulating early innervation of the mouse and chick inner ear. We demonstrate that MIF is a major bioactive component of the previously uncharacterized otocyst-derived factor, which directs initial neurite outgrowth from the statoacoustic ganglion (SAG) to the developing inner ear. Recombinant MIF acts as a neurotrophin in promoting both SAG directional neurite outgrowth and neuronal survival and is expressed in both the developing and mature inner ear of chick and mouse. A MIF receptor, CD74, is found on both embryonic SAG neurons and adult mouse spiral ganglion neurons. Mif knockout mice are hearing impaired and demonstrate altered innervation to the organ of Corti, as well as fewer sensory hair cells. Furthermore, mouse embryonic stem cells become neuron-like when exposed to picomolar levels of MIF, suggesting the general importance of this cytokine in neural development. PMID:23172918

  2. Delayed intramuscular human neurotrophin-3 improves recovery in adult and elderly rats after stroke

    PubMed Central

    Duricki, Denise A.; Hutson, Thomas H.; Kathe, Claudia; Soleman, Sara; Gonzalez-Carter, Daniel; Petruska, Jeffrey C.; Shine, H. David; Chen, Qin; Wood, Tobias C.; Bernanos, Michel; Cash, Diana; Williams, Steven C. R.; Gage, Fred H.

    2016-01-01

    There is an urgent need for a therapy that reverses disability after stroke when initiated in a time frame suitable for the majority of new victims. We show here that intramuscular delivery of neurotrophin-3 (NT3, encoded by NTF3) can induce sensorimotor recovery when treatment is initiated 24 h after stroke. Specifically, in two randomized, blinded preclinical trials, we show improved sensory and locomotor function in adult (6 months) and elderly (18 months) rats treated 24 h following cortical ischaemic stroke with human NT3 delivered using a clinically approved serotype of adeno-associated viral vector (AAV1). Importantly, AAV1-hNT3 was given in a clinically-feasible timeframe using a straightforward, targeted route (injections into disabled forelimb muscles). Magnetic resonance imaging and histology showed that recovery was not due to neuroprotection, as expected given the delayed treatment. Rather, treatment caused corticospinal axons from the less affected hemisphere to sprout in the spinal cord. This treatment is the first gene therapy that reverses disability after stroke when administered intramuscularly in an elderly body. Importantly, phase I and II clinical trials by others show that repeated, peripherally administered high doses of recombinant NT3 are safe and well tolerated in humans with other conditions. This paves the way for NT3 as a therapy for stroke. PMID:26614754

  3. Polybutylcyanoacrylate nanoparticle-mediated neurotrophin-3 gene delivery for differentiating iPS cells into neurons.

    PubMed

    Chung, Chiu-Yen; Yang, Jen-Tsung; Kuo, Yung-Chih

    2013-07-01

    Guided neuronal differentiation of induced pluripotent stem cells (iPSCs) with genetic regulation is an important issue in biomedical research and in clinical practice for nervous regeneration and repair. To enhance the intracellular delivery of plasmid DNA (pDNA), polybutylcyanoacrylate (PBCA) nanoparticles (NPs) were employed to mediate the transport of neurotrophin-3 (NT-3) into iPSCs. The ability of iPSCs to differentiate into neuronal lineages was shown by immunofluorescent staining, western blotting, and flow cytometry. By transmission electron microscopy, we found that PBCA NPs could efficiently grasp pDNA, thereby increasing the particle size and conferring a negative surface charge. In addition, the treatments with PBCA NP/NT-3 complexes enhanced the expression of NT-3, TrkC, NH-H, NSE, and PSD95 by differentiating iPSCs. Neurons produced from iPSCs were incapable of returning to pluripotency, demonstrating with a series of differentiation scheme for adipogenesis and osteogenesis. The pretreatment with PBCA NP/NT-3 complexes can be one of critical biotechnologies and effective delivery systems in gene transfection to accelerate the differentiation of iPSCs into neurons. PMID:23623427

  4. Delayed intramuscular human neurotrophin-3 improves recovery in adult and elderly rats after stroke.

    PubMed

    Duricki, Denise A; Hutson, Thomas H; Kathe, Claudia; Soleman, Sara; Gonzalez-Carter, Daniel; Petruska, Jeffrey C; Shine, H David; Chen, Qin; Wood, Tobias C; Bernanos, Michel; Cash, Diana; Williams, Steven C R; Gage, Fred H; Moon, Lawrence D F

    2016-01-01

    There is an urgent need for a therapy that reverses disability after stroke when initiated in a time frame suitable for the majority of new victims. We show here that intramuscular delivery of neurotrophin-3 (NT3, encoded by NTF3) can induce sensorimotor recovery when treatment is initiated 24 h after stroke. Specifically, in two randomized, blinded preclinical trials, we show improved sensory and locomotor function in adult (6 months) and elderly (18 months) rats treated 24 h following cortical ischaemic stroke with human NT3 delivered using a clinically approved serotype of adeno-associated viral vector (AAV1). Importantly, AAV1-hNT3 was given in a clinically-feasible timeframe using a straightforward, targeted route (injections into disabled forelimb muscles). Magnetic resonance imaging and histology showed that recovery was not due to neuroprotection, as expected given the delayed treatment. Rather, treatment caused corticospinal axons from the less affected hemisphere to sprout in the spinal cord. This treatment is the first gene therapy that reverses disability after stroke when administered intramuscularly in an elderly body. Importantly, phase I and II clinical trials by others show that repeated, peripherally administered high doses of recombinant NT3 are safe and well tolerated in humans with other conditions. This paves the way for NT3 as a therapy for stroke. PMID:26614754

  5. Immunohistochemical profile of various neurotransmitters, neurotrophins and MIB-1 in cholesteatomas of the petrous bone.

    PubMed

    Artico, Marco; Bronzetti, Elena; Lo Vasco, Vincenza Rita; Ionta, Brunella; Alicino, Valentina; D'Ambrosio, Anna; Magliulo, Giuseppe

    2008-01-01

    Compared to the normal epidermal epithelium, cholesteatomas have altered growth properties characterized by the excessive growth of keratinocytes leading to mucosal destruction. Either congenital or acquired, these lesions, which grow in the middle ear space, the petrous apex or the mastoid of temporal bones, are mostly considered benign skin tumoral lesions. However, many questions remain concerning their pathophysiology. Numerous studies have been proposed to identify those cholesteatoma lesions at risk of recurrence, a possible event that may cause hearing loss. We examined patients with petrous apex or mastoid cholesteatoma in order to analyze the expression of various neurotransmitters, neurotrophins and their receptors and the Ki-67 antigen for identification of a possible relationship between clinical outcome and histopathological behaviour in terms of the proliferative activity of cholesteatomas. Expression of the analyzed molecules was studied using immunohistochemical methods in seven adult patients with petrous apex cholesteatoma who underwent surgical removal of the lesion. Our results, in accordance with published data, confirm that Molecular Immunology Borstel-1 (MIB-1) and certain neurotransmitters could be useful in the prognostic evaluation of the risk of recurrence of aggressive forms of cholesteatoma. PMID:21479416

  6. Neurotrophin expression and laryngeal muscle pathophysiology following recurrent laryngeal nerve transection

    PubMed Central

    WANG, BAOXIN; YUAN, JUNJIE; XU, JIAFENG; XIE, JIN; WANG, GUOLIANG; DONG, PIN

    2016-01-01

    Laryngeal palsy often occurs as a result of recurrent laryngeal or vagal nerve injury during oncological surgery of the head and neck, affecting quality of life and increasing economic burden. Reinnervation following recurrent laryngeal nerve (RLN) injury is difficult despite development of techniques, such as neural anastomosis, nerve grafting and creation of a laryngeal muscle pedicle. In the present study, due to the limited availability of human nerve tissue for research, a rat model was used to investigate neurotrophin expression and laryngeal muscle pathophysiology in RLN injury. Twenty-five male Sprague-Dawley rats underwent right RLN transection with the excision of a 5-mm segment. Vocal fold movements, vocalization, histology and immunostaining were evaluated at different time-points (3, 6, 10 and 16 weeks). Although vocalization was restored, movement of the vocal fold failed to return to normal levels following RLN injury. The expression of brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor differed in the thyroarytenoid (TA) and posterior cricoarytenoid muscles. The number of axons did not increase to baseline levels over time. Furthermore, normal muscle function was unlikely with spontaneous reinnervation. During regeneration following RLN injury, differences in the expression levels of neurotrophic factors may have resulted in preferential reinnervation of the TA muscles. Data from the present study indicated that neurotrophic factors may be applied for restoring the function of the laryngeal nerve following recurrent injury. PMID:26677138

  7. Mast cell-derived neurotrophin 4 mediates allergen-induced airway hyperinnervation in early life

    PubMed Central

    Patel, Kruti R.; Aven, Linh; Shao, Fengzhi; Krishnamoorthy, Nandini; Duvall, Melody G.; Levy, Bruce D.; Ai, Xingbin

    2016-01-01

    Asthma often progresses from early episodes of insults. How early life events connect to long-term airway dysfunction remains poorly understood. We demonstrated previously that increased neurotrophin 4 (NT4) levels following early life allergen exposure cause persistent changes in airway smooth muscle (ASM) innervation and airway hyper-reactivity (AHR) in mice. Herein, we identify pulmonary mast cells as a key source of aberrant NT4 expression following early insults. NT4 is selectively expressed by ASM and mast cells in mice, nonhuman primates and humans. We show in mice that mast cell-derived NT4 is dispensable for ASM innervation during development. However, upon insults, mast cells expand in number and degranulate to release NT4 and thus become the major source of NT4 under pathological condition. Adoptive transfer of wild type mast cells, but not NT4−/− mast cells restores ASM hyperinnervation and AHR in KitW-sh/W-sh mice following early life insults. Notably, an infant nonhuman primate model of asthma also exhibits ASM hyperinnervation associated with the expansion and degranulation of mast cells. Together, these findings identify an essential role of mast cells in mediating ASM hyperinnervation following early life insults by producing NT4. This role may be evolutionarily conserved in linking early insults to long-term airway dysfunction. PMID:26860818

  8. Expression of TNF and TNF receptors (p55 and p75) in the rat brain after focal cerebral ischemia.

    PubMed Central

    Botchkina, G. I.; Meistrell, M. E.; Botchkina, I. L.; Tracey, K. J.

    1997-01-01

    Cerebral ischemia induces a rapid and dramatic up-regulation of tumor necrosis factor (TNF) protein and mRNA, but the cellular sources of TNF in the ischemic brain have not been defined. The diverse activities of TNF are mediated via ligand interaction with two distinct receptors, p55 and p75, which activate separate intracellular signal transduction pathways, leading to distinct biological effects. Since the effects of cerebral ischemia on TNF receptor (TNFR) expression are unknown, we examined the cellular localization and protein expression of TNF and its two receptors in the rat cerebral cortex in response to permanent middle cerebral artery (MCA) occlusion. The results indicate that focal. cerebral ischemia up-regulates expression of TNF and both TNFRs within the ischemic cortex. The most abundant type of TNF immunoreactivity (IR) was a punctate and filamentous pattern of transected cellular processes; however, cell bodies of neurons, astrocytes, and microglia, as well as infiltrating polymorphonuclear (PMN) leukocytes also showed TNF IR. Brain vasculature displayed TNF IR not only within endothelial cells but also in the perivascular space. MCA occlusion induced significant up-regulation of TNF receptors, with p55 IR appearing within 6 hr, significantly before the appearance of p75 IR at 24 hr after the onset of ischemia. Since p55 has been implicated in transducing cytotoxic signalling of TNF, these results support the proposed injurious role of excessive TNF produced during the acute response to cerebral ischemia. Images FIG. 7 FIG. 3 FIG. 1 FIG. 2 FIG. 4 FIG. 5 FIG. 6 FIG. 8 FIG. 9 PMID:9407552

  9. Therapeutic Non-Toxic Doses of TNF Induce Significant Regression in TNFR2-p75 Knockdown Lewis Lung Carcinoma Tumor Implants

    PubMed Central

    Sasi, Sharath P.; Bae, Sanggyu; Song, Jin; Perepletchikov, Aleksandr; Schneider, Douglas; Carrozza, Joseph; Yan, Xinhua; Kishore, Raj; Enderling, Heiko; Goukassian, David A.

    2014-01-01

    Tumor necrosis factor-alpha (TNF) binds to two receptors: TNFR1/p55-cytotoxic and TNFR2/p75-pro-survival. We have shown that tumor growth in p75 knockout (KO) mice was decreased more than 2-fold in Lewis lung carcinoma (LLCs). We hypothesized that selective blocking of TNFR2/p75 LLCs may sensitize them to TNF-induced apoptosis and affect the tumor growth. We implanted intact and p75 knockdown (KD)-LLCs (>90%, using shRNA) into wild type (WT) mice flanks. On day 8 post-inoculation, recombinant murine (rm) TNF-α (12.5 ng/gr of body weight) or saline was injected twice daily for 6 days. Tumor volumes (tV) were measured daily and tumor weights (tW) on day 15, when study was terminated due to large tumors in LLC+TNF group. Tubular bones, spleens and peripheral blood (PB) were examined to determine possible TNF toxicity. There was no significant difference in tV or tW between LLC minus (-) TNF and p75KD/LLC-TNF tumors. Compared to 3 control groups, p75KD/LLC+TNF showed >2-5-fold decreases in tV (p<0.001) and tW (p<0.0001). There was no difference in tV or tW end of study vs. before injections in p75KD/LLC+TNF group. In 3 other groups tV and tW were increased 2.7-4.5-fold (p<0.01, p<0.0002 and p<0.0001). Pathological examination revealed that 1/3 of p75KD/LLC+rmTNF tumors were 100% necrotic, the remaining revealed 40-60% necrosis. No toxicity was detected in bone marrow, spleen and peripheral blood. We concluded that blocking TNFR2/p75 in LLCs combined with intra-tumoral rmTNF injections inhibit LLC tumor growth. This could represent a novel and effective therapy against lung neoplasms and a new paradigm in cancer therapeutics. PMID:24664144

  10. D77, one benzoic acid derivative, functions as a novel anti-HIV-1 inhibitor targeting the interaction between integrase and cellular LEDGF/p75

    SciTech Connect

    Du Li; Zhao Yaxue; Chen, Jing; Yang Liumeng; Zheng Yongtang; Tang Yun Shen Xu Jiang Hualiang

    2008-10-10

    Integration of viral-DNA into host chromosome mediated by the viral protein HIV-1 integrase (IN) is an essential step in the HIV-1 life cycle. In this process, Lens epithelium-derived growth factor (LEDGF/p75) is discovered to function as a cellular co-factor for integration. Since LEDGF/p75 plays an important role in HIV integration, disruption of the LEDGF/p75 interaction with IN has provided a special interest for anti-HIV agent discovery. In this work, we reported that a benzoic acid derivative, 4-[(5-bromo-4-{l_brace}[2,4-dioxo-3-(2-oxo-2-phenylethyl) -1,3-thiazolidin-5-ylidene]methyl{r_brace}-2-ethoxyphenoxy)methyl]benzoic acid (D77) could potently inhibit the IN-LEDGF/p75 interaction and affect the HIV-1 IN nuclear distribution thus exhibiting antiretroviral activity. Molecular docking with site-directed mutagenesis analysis and surface plasmon resonance (SPR) binding assays has clarified possible binding mode of D77 against HIV-1 integrase. As the firstly discovered small molecular compound targeting HIV-1 integrase interaction with LEDGF/p75, D77 might supply useful structural information for further anti-HIV agent discovery.

  11. The Transcriptional Response of Neurotrophins and Their Tyrosine Kinase Receptors in Lumbar Sensorimotor Circuits to Spinal Cord Contusion is Affected by Injury Severity and Survival Time

    PubMed Central

    Hougland, M. Tyler; Harrison, Benjamin J.; Magnuson, David S. K.; Rouchka, Eric C.; Petruska, Jeffrey C.

    2013-01-01

    Traumatic spinal cord injury (SCI) results in changes to the anatomical, neurochemical, and physiological properties of cells in the central and peripheral nervous system. Neurotrophins, acting by binding to their cognate Trk receptors on target cell membranes, contribute to modulation of anatomical, neurochemical, and physiological properties of neurons in sensorimotor circuits in both the intact and injured spinal cord. Neurotrophin signaling is associated with many post-SCI changes including maladaptive plasticity leading to pain and autonomic dysreflexia, but also therapeutic approaches such as training-induced locomotor improvement. Here we characterize expression of mRNA for neurotrophins and Trk receptors in lumbar dorsal root ganglia (DRG) and spinal cord after two different severities of mid-thoracic injury and at 6 and 12 weeks post-SCI. There was complex regulation that differed with tissue, injury severity, and survival time, including reversals of regulation between 6 and 12 weeks, and the data suggest that natural regulation of neurotrophins in the spinal cord may continue for months after birth. Our assessments determined that a coordination of gene expression emerged at the 12-week post-SCI time point and bioinformatic analyses address possible mechanisms. These data can inform studies meant to determine the role of the neurotrophin signaling system in post-SCI function and plasticity, and studies using this signaling system as a therapeutic approach. PMID:23316162

  12. Treatment challenges for community oncologists treating postmenopausal women with endocrine-resistant, hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer.

    PubMed

    Gradishar, William J

    2016-01-01

    Community-based oncologists are faced with challenges and opportunities when delivering quality patient care, including high patient volumes and diminished resources; however, there may be the potential to deliver increased patient education and subsequently improve outcomes. This review discusses the treatment of postmenopausal women with endocrine-resistant, hormone receptor-positive, human epidermal growth factor receptor 2- negative advanced breast cancer in order to illustrate considerations in the provision of pertinent quality education in the treatment of these patients and the management of therapy-related adverse events. An overview of endocrine-resistant breast cancer and subsequent treatment challenges is also provided. Approved treatment options for endocrine-resistant breast cancer include hormonal therapies and mammalian target of rapamycin inhibitors. Compounds under clinical investigation are also discussed. PMID:27468248

  13. Treatment challenges for community oncologists treating postmenopausal women with endocrine-resistant, hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer

    PubMed Central

    Gradishar, William J

    2016-01-01

    Community-based oncologists are faced with challenges and opportunities when delivering quality patient care, including high patient volumes and diminished resources; however, there may be the potential to deliver increased patient education and subsequently improve outcomes. This review discusses the treatment of postmenopausal women with endocrine-resistant, hormone receptor-positive, human epidermal growth factor receptor 2- negative advanced breast cancer in order to illustrate considerations in the provision of pertinent quality education in the treatment of these patients and the management of therapy-related adverse events. An overview of endocrine-resistant breast cancer and subsequent treatment challenges is also provided. Approved treatment options for endocrine-resistant breast cancer include hormonal therapies and mammalian target of rapamycin inhibitors. Compounds under clinical investigation are also discussed. PMID:27468248

  14. trkC encodes multiple neurotrophin-3 receptors with distinct biological properties and substrate specificities.

    PubMed Central

    Lamballe, F; Tapley, P; Barbacid, M

    1993-01-01

    The trkC gene product gp145trkC is a high affinity signaling receptor for neurotrophin-3 (NT-3), a member of the NGF family of neurotrophic factors. We now report that trkC encodes at least two additional tyrosine protein kinase receptors. These receptors, designated TrkC K2 and TrkC K3, have the same amino acid sequences as gp145trkC (now designated TrkC K1) except for the presence of 14 and 25 additional amino acid residues between kinase subdomains VII and VIII, just downstream from the TDYYR motif which encompasses the putative autophosphorylation site of the Trk receptor family. Upon interaction with their cognate ligand, NT-3, all three TrkC receptor isoforms become rapidly phosphorylated on tyrosine residues and induce DNA synthesis in quiescent cells. However, only TrkC K1 has mitogenic activity in NIH3T3 cells and induces neuronal differentiation of PC12 cells. The different biological properties of these TrkC receptor isoforms probably result from their engagement with different signaling pathways. Whereas TrkC K1 phosphorylates phospholipase C gamma 1 and phosphatidylinositol-3 kinase, TrkC K2 and TrkC K3 do not. TrkC K2 and transcripts encoding TrkC K3 have been identified in various structures of the adult murine brain. These observations suggest that the trophic activities of NT-3 in the mammalian nervous system might be mediated by different TrkC receptor isoforms. Images PMID:8344249

  15. Overexpression of neurotrophin-3 in skeletal muscle alters normal and injury-induced limb control.

    PubMed

    Taylor, M D; Vancura, R; Williams, J M; Riekhof, J T; Taylor, B K; Wright, D E

    2001-01-01

    Transgenic overexpression of neurotrophin-3 (NT-3) in mice increases the number of surviving proprioceptive sensory components, including primary sensory neurons, gamma motoneurons and muscle spindles. The numbers of surviving alpha motoneurons are not affected by NT-3 overexpression (Wright et al., Neuron 19: 503-517, 1997). We have assessed the consequences NT-3-stimulated increase in the proprioceptive sensory system by measuring locomotive abilities of mice that overexpress NT-3 in all skeletal muscles (myo/NT-3 mice). In adulthood, one myo/NT-3 transgenic line continues to express NT-3 at high levels in muscle and maintains a hypertrophied proprioceptive system (high-OE myo/NT-3 mice). Compared to wildtypes, high-OE myo/NT-3 mice have nine times the amount of NT-3 protein in the medial gastrocnemius at six weeks of age. Although appearing normal during ordinary activity, high-OE myo/NT-3 mice display a distinct clasping phenotype when lifted by the tail. High-OE myo/NT-3 mice show severe locomotor deficits when performing beam walking and rotorod testing. These mice also demonstrate aberrant foot positioning during normal walking. However, following sciatic nerve crush, overexpression of NT-3 prevents further abnormalities in paw positioning, suggesting NT-3 may attenuate sensorimotor deficits that occur in response to sciatic nerve injury. Our results suggest that increases in proprioceptive sensory neurons, spindles and gamma motoneurons, along with continued postnatal NT-3 overexpression in muscle significantly disrupt normal locomotor control. Importantly, however, NT-3 may lessen initial deficits and thus improve functional recovery after peripheral nerve injury, suggesting these mice may serve as a good model to study NT-3's role in neuroprotection of proprioceptive afferents. PMID:11794730

  16. Unmasking of Spiral Ganglion Neuron Firing Dynamics by Membrane Potential and Neurotrophin-3

    PubMed Central

    Crozier, Robert A.

    2014-01-01

    Type I spiral ganglion neurons have a unique role relative to other sensory afferents because, as a single population, they must convey the richness, complexity, and precision of auditory information as they shape signals transmitted to the brain. To understand better the sophistication of spiral ganglion response properties, we compared somatic whole-cell current-clamp recordings from basal and apical neurons obtained during the first 2 postnatal weeks from CBA/CaJ mice. We found that during this developmental time period neuron response properties changed from uniformly excitable to differentially plastic. Low-frequency, apical and high-frequency basal neurons at postnatal day 1 (P1)–P3 were predominantly slowly accommodating (SA), firing at low thresholds with little alteration in accommodation response mode induced by changes in resting membrane potential (RMP) or added neurotrophin-3 (NT-3). In contrast, P10–P14 apical and basal neurons were predominately rapidly accommodating (RA), had higher firing thresholds, and responded to elevation of RMP and added NT-3 by transitioning to the SA category without affecting the instantaneous firing rate. Therefore, older neurons appeared to be uniformly less excitable under baseline conditions yet displayed a previously unrecognized capacity to change response modes dynamically within a remarkably stable accommodation framework. Because the soma is interposed in the signal conduction pathway, these specializations can potentially lead to shaping and filtering of the transmitted signal. These results suggest that spiral ganglion neurons possess electrophysiological mechanisms that enable them to adapt their response properties to the characteristics of incoming stimuli and thus have the capacity to encode a wide spectrum of auditory information. PMID:25031408

  17. Dysregulated brain immunity and neurotrophin signaling in Rett syndrome and autism spectrum disorders.

    PubMed

    Theoharides, Theoharis C; Athanassiou, Marianna; Panagiotidou, Smaro; Doyle, Robert

    2015-02-15

    Rett syndrome is a neurodevelopmental disorder, which occurs in about 1:15,000 females and presents with neurologic and communication defects. It is transmitted as an X-linked dominant linked to mutations of the methyl-CpG-binding protein (MeCP2), a gene transcription suppressor, but its definitive pathogenesis is unknown thus hindering development of effective treatments. Almost half of children with Rett syndrome also have behavioral symptoms consistent with those of autism spectrum disorders (ASDs). PubMed was searched (2005-2014) using the terms: allergy, atopy, brain, brain-derived neurotrophic factor (BDNF), corticotropin-releasing hormone (CRH), cytokines, gene mutations, inflammation, mast cells (MCs), microglia, mitochondria, neurotensin (NT), neurotrophins, seizures, stress, and treatment. There are a number of intriguing differences and similarities between Rett syndrome and ASDs. Rett syndrome occurs in females, while ASDs more often in males, and the former has neurologic disabilities unlike ASDs. There is evidence of dysregulated immune system early in life in both conditions. Lack of microglial phagocytosis and decreased levels of BDNF appear to distinguish Rett syndrome from ASDs, in which there is instead microglia activation and/or proliferation and possibly defective BDNF signaling. Moreover, brain mast cell (MC) activation and focal inflammation may be more prominent in ASDs than Rett syndrome. The flavonoid luteolin blocks microglia and MC activation, provides BDNF-like activity, reverses Rett phenotype in mouse models, and has a significant benefit in children with ASDs. Appropriate formulations of luteolin or other natural molecules may be useful in the treatment of Rett syndrome. PMID:25669997

  18. Effect of neurotrophin-3 precursor on glutamate-induced calcium homeostasis deregulation in rat cerebellum granule cells.

    PubMed

    Safina, Dina R; Surin, Alexander M; Pinelis, Vsevolod G; Kostrov, Sergey V

    2015-12-01

    Neurotrophin-3 (NT-3) belongs to the family of highly conserved dimeric growth factors that controls the differentiation and activity of various neuronal populations. Mammals contain both the mature (NT-3) and the precursor (pro-NT-3) forms of neurotrophin. Members of the neurotrophin family are involved in the regulation of calcium homeostasis in neurons; however, the role of NT-3 and pro-NT-3 in this process remains unclear. The current study explores the effects of NT-3 and pro-NT-3 on disturbed calcium homeostasis and decline of mitochondrial potential induced by a neurotoxic concentration of glutamate (Glu; 100 µM) in the primary culture of rat cerebellar granule cells. In this Glu excitotoxicity model, mature NT-3 had no effect on the induced changes in Ca²⁺ homeostasis. In contrast, pro-NT-3 decreased the period of delayed calcium deregulation (DCD) and concurrent strong mitochondrial depolarization. According to the amplitude of the increase in the intracellular free Ca²⁺ concentration ([Ca²⁺]i ) and Fura-2 fluorescence quenching by Mn²⁺ within the first 20 sec of exposure to Glu, pro-NT-3 had no effect on the initial rate of Ca²⁺ entry into neurons. During the lag period preceding DCD, the mean amplitude of [Ca²⁺]i rise was 1.2-fold greater in the presence of pro-NT-3 than in the presence of Glu alone (1.67 ±  0.07 and 1.39 ± 0.04, respectively, P < 0.05). The Glu-induced changes in Са²⁺ homeostasis in the presence of pro-NT-3 likely are due to the decreased rate of Са²⁺ removal from the cytosol during the DCD latency period. PMID:26346533

  19. Ethnic differences in initiation and timing of adjuvant endocrine therapy among older women with hormone receptor-positive breast cancer enrolled in Medicare Part D

    PubMed Central

    Du, Xianglin L.

    2016-01-01

    The aim of this study was to determine whether there are racial/ethnic differences in initiation and timing of adjuvant endocrine therapy (AET) after Medicare Part D drug coverage. We conducted a retrospective cohort study using data from the Surveillance, Epidemiology, and End Results-Medicare-linked data to assess ethnic, socio-demographic, and tumor characteristic variations in the initiation of AET among patients ≥65 with hormone receptor-positive breast cancer in 2007–2009 enrolled in Medicare Part D through 2010. Logistic regression models were performed to assess the association between race/ethnicity and the initiation of tamoxifen, aromatase inhibitors (AIs), and overall AET (tamoxifen or AIs) within the first 12 months of diagnosis. Of the 12,198 women with hormone receptor-positive breast cancer, 74.8 % received AET within 12 months of diagnosis, of which 17.3 % received tamoxifen and 82.8 % received AIs. After controlling for all variables, only Asian women were found to have a greater odds of initiation of overall AET compared to non-Hispanic white women (odds ratio (OR): 1.28, 95 % CI: 1.03–1.58). Hispanic Mexicans and non-Hispanic black patients had a significantly lower odds of tamoxifen initiation (0.70, 0.54–0.91; 0.25, 0.10–0.62). For AI initiation, Hispanic Mexicans and Asians had a higher odds compared to non-Hispanic white women (2.06, 1.34–3.10; 1.33, 1.11–1.61). A suboptimal proportion of women (25.2 %) did not initiate AET within 12 months of diagnosis and therefore did not receive the full benefits of treatment to reduce the risk of breast cancer recurrence and mortality. Racial/ethnic differences in the initiation of tamoxifen and AIs have important implications that require further investigation. PMID:26786154

  20. Testicular expression of NGF, TrkA and p75 during seasonal spermatogenesis of the wild ground squirrel (Citellus dauricus Brandt).

    PubMed

    Zhang, H; Wang, Y; Zhang, J; Wang, L; Li, Q; Sheng, X; Han, Y; Yuan, Z; Weng, Q

    2015-01-01

    The nerve growth factor (NGF) not only has an essential effect on the nervous system, but also plays an important role in a variety of non-neuronal systems, such as the reproductive system. The aim of this study was to investigate the seasonal changes in expression of NGF and its receptors (TrkA and p75) in testes of the wild ground squirrel during the breeding and nonbreeding seasons. Immunolocalization for NGF was detected mainly in Leydig cells and Sertoli cells in testes of the breeding and nonbreeding seasons. The immunoreactivity of TrkA was highest in the elongated spermatids, whereas p75 in spermatogonia and spermatocytes in testes of the breeding season. In the nonbreeding season testes, TrkA showed positive immunostainings in Leydig cells, spermatogonia and primary spermatocytes, while p75 showed positive signals in spermatogonia and primary spermatocytes. Consistent with the immunohistochemical results, the mean mRNA and protein level of NGF and TrkA were higher in the testes of the breeding season, and then decreased to a relatively low level in the nonbreeding season. In addition, the concentration of plasma gonadotropins and testosterone were assayed by radioimmunoassay (RIA), and the results showed a significant seasonal change between the breeding and nonbreeding seasons. To conclude, these results of this study provide the first evidence on the potential involvement of NGF and its receptor, TrkA and p75 in the seasonal spermatogenesis and testicular function change of the wild ground squirrel. PMID:26428886

  1. Virtual-screening targeting Human Immunodeficiency Virus type 1 integrase-lens epithelium-derived growth factor/p75 interaction for drug development.

    PubMed

    Gu, Wan-Gang; Liu, Bai-Nan; Yuan, Jun-Fa

    2015-02-01

    Three integrase (IN) inhibitors have been approved by FDA for clinical treatment of Human Immunodeficiency Virus (HIV) infection. This stimulates more researchers to focus their studies on this target for anti-HIV drug development. Three steps regarding of IN activity have been validated for inhibitor discovery: strand transfer, 3'-terminal processing, and IN-lens epithelium-derived growth factor (LEDGF)/p75 interaction. Among them, IN-LEDGF/p75 interaction is a new target validated in recent years. Emergence of drug-resistant virus strains makes this target appealing to pharmacologists. Compared with the traditional screening methods such as AlphaScreen and cell-based screening developed for IN inhibitor discovery, virtual screening is a powerful technique in modern drug discovery. Here we summarized the recent advances of virtual-screening targeting IN-LEDFG/p75 interaction. The combined application of virtual screening and experiments in drug discovery against IN-LEDFG/p75 interaction sheds light on anti-HIV research and drug discovery. PMID:25230778

  2. High affinity binding proteins for the regulatory subunit of cAMP-dependent protein kinase: Cloning, characterization and expression of P150 and P75

    SciTech Connect

    Bregman, D.B.

    1989-01-01

    cAMP-dependent protein kinase II-B appears to be adapted for function in the mammalian central nervous system (CNS) via the properties of its regulatory subunit (RII-B). RII-B is selectively expressed in brain, tightly associated with cerebral cortex membranes and avidly complexed by the bovine brain calmodulin-binding protein designated P75. Complexes of RII-B and P75 polypeptides can be purified to near-homogeneity from either membrane or cytosolic fractions of brain homogenates, suggested that the binding protein plays a role in determining the subcellular localization and/or other CNS-specific properties of protein kinase II-B. In general, a single high-affinity RII-B binding protein is expressed in the brains of mammals, but the size of the protein varies (e.g., cow: 75 kDa; rat: 150 kDa). To investigate these non-abundant and CNS-enriched RII-B binding proteins, cDNAs for bovine brain P75 and rat brain P150, the homologue of P75, have been cloned and characterized. The cDNAs were retrieved from bovine and rat lambda gt11 expression libraries using {sup 32}P-RII-B as a functional probe. cDNA inserts subcloned into pIN-IA2 or pET-3b expression plasmids directed the production of partial P75 and P150 polypeptides in E. coli that exhibited RII-B binding activity. P150 cDNAs hybridize with 3 rat mRNAs (7.3, 5.0, 4.2 kb) that are present in brain and lung, but not other tissues. These mRNAs are not detected in fetal brain, but are expressed during the period of post-natal synaptogenesis and in adult rats. The P75 cDNA hybridizes to a 6 kb bovine brain mRNA. Finally, 3'-deletion analysis demonstrated that the C-terminal 15-25 amino acids of P150 or P75 are essential for binding with RII-B.

  3. Amyloid beta₁₋₄₂ (Aβ₄₂) up-regulates the expression of sortilin via the p75(NTR)/RhoA signaling pathway.

    PubMed

    Saadipour, Khalil; Yang, Miao; Lim, Yoon; Georgiou, Kristen; Sun, Ying; Keating, Damien; Liu, Jia; Wang, Ye-Ran; Gai, Wei-Ping; Zhong, Jin-Hua; Wang, Yan-Jiang; Zhou, Xin-Fu

    2013-10-01

    Sortilin, a Golgi sorting protein and a member of the VPS10P family, is the co-receptor for proneurotrophins, regulates protein trafficking, targets proteins to lysosomes, and regulates low density lipoprotein metabolism. The aim of this study was to investigate the expression and regulation of sortilin in Alzheimer's disease (AD). A significantly increased level of sortilin was found in human AD brain and in the brains of 6-month-old swedish-amyloid precursor protein/PS1dE9 transgenic mice. Aβ₄₂ enhanced the protein and mRNA expression levels of sortilin in a dose- and time-dependent manner in SH-SY5Y cells, but had no effect on sorLA. In addition, proBDNF also significantly increased the protein and mRNA expression of sortilin in these cells. The recombinant extracellular domain of p75(NTR) (P75ECD-FC), or the antibody against the extracellular domain of p75(NTR), blocked the up-regulation of sortilin induced by Amyloid-β protein (Aβ), suggesting that Aβ₄₂ increased the expression level of sortilin and mRNA in SH-SY5Y via the p75(NTR) receptor. Inhibition of ROCK, but not Jun N-terminal kinase, suppressed constitutive and Aβ₄₂-induced expression of sortilin. In conclusion, this study shows that sortilin expression is increased in the AD brain in human and mice and that Aβ₄₂ oligomer increases sortilin gene and protein expression through p75(NTR) and RhoA signaling pathways, suggesting a potential physiological interaction of Aβ₄₂ and sortilin in Alzheimer's disease. PMID:23895422

  4. Transgenic mice expressing the p75 CCAAT-displacement protein/Cut homeobox isoform develop a myeloproliferative disease-like myeloid leukemia.

    PubMed

    Cadieux, Chantal; Fournier, Sylvie; Peterson, Alan C; Bédard, Christian; Bedell, Barry J; Nepveu, Alain

    2006-10-01

    The p75 CCAAT-displacement protein/Cut homeobox (CDP/Cux) isoform was previously reported to be overexpressed in human breast cancers. To investigate its oncogenic potential, we engineered two transgenic mouse lines expressing p75 CDP/Cux under the control of the mouse mammary tumor virus-long terminal repeat. The FVB strain of mouse is generally used in the generation of mouse models for breast cancer. The transgene was introduced into the hprt locus of 129/Ola embryonic stem cells and, following germ line passage, was backcrossed onto the FVB and C57BL/6 mouse strains. Here, we describe the phenotype of p75 CDP/Cux transgenic virgin female mice of the first backcross generations. We report that after a long latency period, approximately 33% of mice from two independent transgenic lines and from backcrosses into either the FVB or the C57BL/6 strains succumbed to a similar disease characterized by splenomegaly, hepatomegaly, and frequent infiltration of leukocytes into nonhematopoietic organs like the kidneys and lungs. Although an excess of B or T cells was observed in three diseased mice, in 17 other cases, histologic and flow cytometry analyses revealed the expansion of a population of neutrophils in the blood, spleen, and bone marrow. The increase in neutrophils correlated with signs of anemia and thrombocytopenia, whereas there was no indication of a reactive process. Therefore, p75 CDP/Cux transgenic mice displayed heightened susceptibility to a disease defined as a myeloproliferative disease-like myeloid leukemia. These results indicate that the overexpression of p75 CDP/Cux could alter homeostasis in the hematopoietic compartment. PMID:17018605

  5. Binding of neurotrophin-3 to its neuronal receptors and interactions with nerve growth factor and brain-derived neurotrophic factor.

    PubMed Central

    Rodríguez-Tébar, A; Dechant, G; Götz, R; Barde, Y A

    1992-01-01

    Neurotrophin-3 (NT-3) has low-affinity (Kd = 8 x 10(-10) M), as well as high-affinity receptors (Kd = 1.8 x 10(-11) M) on embryonic chick sensory neurons, the latter in surprisingly high numbers. Like the structurally related proteins nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), NT-3 also binds to the low-affinity NGF receptor, a molecule that we suggest to designate low-affinity neurotrophin receptor (LANR). NT-3 dissociates from the LANR much more rapidly than BDNF, and more slowly than NGF. The binding of labelled NT-3 to the LANR can be reduced by half using a concentration of BDNF corresponding to the Kd of BDNF to the LANR. In contrast, the binding of NT-3 to its high-affinity neuronal receptors can only be prevented by BDNF or NGF when used at concentrations several thousand-fold higher than those corresponding to their Kd to their high-affinity neuronal receptors. Thus, specific high-affinity NT-3 receptors exist on sensory neurons that can readily discriminate between three structurally related ligands. These findings, including the remarkable property of the LANR to bind three related ligands with similar affinity, but different rate constants, are discussed. PMID:1547788

  6. Rapid Trimming of Cell Surface Polysialic Acid (PolySia) by Exovesicular Sialidase Triggers Release of Preexisting Surface Neurotrophin.

    PubMed

    Sumida, Mizuki; Hane, Masaya; Yabe, Uichiro; Shimoda, Yasushi; Pearce, Oliver M T; Kiso, Makoto; Miyagi, Taeko; Sawada, Makoto; Varki, Ajit; Kitajima, Ken; Sato, Chihiro

    2015-05-22

    As acidic glycocalyx on primary mouse microglial cells and a mouse microglial cell line Ra2, expression of polysialic acid (polySia/PSA), a polymer of the sialic acid Neu5Ac (N-acetylneuraminic acid), was demonstrated. PolySia is known to modulate cell adhesion, migration, and localization of neurotrophins mainly on neural cells. PolySia on Ra2 cells disappeared very rapidly after an inflammatory stimulus. Results of knockdown and inhibitor studies indicated that rapid surface clearance of polySia was achieved by secretion of endogenous sialidase Neu1 as an exovesicular component. Neu1-mediated polySia turnover was accompanied by the release of brain-derived neurotrophic factor normally retained by polySia molecules. Introduction of a single oxygen atom change into polySia by exogenous feeding of the non-neural sialic acid Neu5Gc (N-glycolylneuraminic acid) caused resistance to Neu1-induced polySia turnover and also inhibited the associated release of brain-derived neurotrophic factor. These results indicate the importance of rapid turnover of the polySia glycocalyx by exovesicular sialidases in neurotrophin regulation. PMID:25750127

  7. Repeated exposure to neurotoxic levels of chlorpyrifos alters hippocampal expression of neurotrophins and neuropeptides.

    PubMed

    Lee, Young S; Lewis, John A; Ippolito, Danielle L; Hussainzada, Naissan; Lein, Pamela J; Jackson, David A; Stallings, Jonathan D

    2016-01-18

    Chlorpyrifos (CPF), an organophosphorus pesticide (OP), is one of the most widely used pesticides in the world. Subchronic exposures to CPF that do not cause cholinergic crisis are associated with problems in cognitive function (i.e., learning and memory deficits), but the biological mechanism(s) underlying this association remain speculative. To identify potential mechanisms of subchronic CPF neurotoxicity, adult male Long Evans (LE) rats were administered CPF at 3 or 10mg/kg/d (s.c.) for 21 days. We quantified mRNA and non-coding RNA (ncRNA) expression profiles by RNA-seq, microarray analysis and small ncRNA sequencing technology in the CA1 region of the hippocampus. Hippocampal slice immunohistochemistry was used to determine CPF-induced changes in protein expression and localization patterns. Neither dose of CPF caused overt clinical signs of cholinergic toxicity, although after 21 days of exposure, cholinesterase activity was decreased to 58% or 13% of control levels in the hippocampus of rats in the 3 or 10mg/kg/d groups, respectively. Differential gene expression in the CA1 region of the hippocampus was observed only in the 10mg/kg/d dose group relative to controls. Of the 1382 differentially expressed genes identified by RNA-seq and microarray analysis, 67 were common to both approaches. Differential expression of six of these genes (Bdnf, Cort, Crhbp, Nptx2, Npy and Pnoc) was verified in an independent CPF exposure study; immunohistochemistry demonstrated that CRHBP and NPY were elevated in the CA1 region of the hippocampus at 10mg/kg/d CPF. Gene ontology enrichment analysis suggested association of these genes with receptor-mediated cell survival signaling pathways. miR132/212 was also elevated in the CA1 hippocampal region, which may play a role in the disruption of neurotrophin-mediated cognitive processes after CPF administration. These findings identify potential mediators of CPF-induced neurobehavioral deficits following subchronic exposure to CPF at

  8. Knockout of the norepinephrine transporter and pharmacologically diverse antidepressants prevent behavioral and brain neurotrophin alterations in two chronic stress models of depression

    PubMed Central

    Haenisch, Britta; Bilkei-Gorzo, Andras; Caron, Marc G.; Bönisch, Heinz

    2009-01-01

    Diverse factors such as changes in neurotrophins and brain plasticity have been proposed to be involved in the actions of antidepressant drugs (ADs). However, in mouse models of depression based on chronic stress, it is still unclear whether simultaneous changes in behavior and neurotrophin expression occur and whether these changes can be corrected or prevented comparably by chronic administration of ADs or genetic manipulations that produce antidepressant-like effects such as the knockout (KO) of the norepinephrine transporter (NET) gene. Here we show that chronic restraint or social defeat stress induce comparable effects on behavior and changes in the expression of neurotrophins in depression-related brain regions. Chronic stress caused down-regulation of BDNF, NGF and NT-3 in hippocampus and cerebral cortex and up-regulation of these targets in striatal regions. In wild-type mice, these effects could be prevented by concomitant chronic administration of five pharmacologically diverse ADs. In contrast, NETKO mice were resistant to stress-induced depressive-like changes in behavior and brain neurotrophin expression. Thus, the resistance of the NETKO mice to the stress-induced depression-associated behaviors and biochemical changes highlight the importance of noradrenergic pathways in the maintenance of mood. In addition, these mice represent a useful model to study depression-resistant behaviors, and they might help to provide deeper insights into the identification of downstream targets involved in the mechanisms of antidepressants. PMID:19694905

  9. Spatial Navigation in Complex and Radial Mazes in APP23 Animals and Neurotrophin Signaling as a Biological Marker of Early Impairment

    ERIC Educational Resources Information Center

    Hellweg, Rainer; Huber, Roman; Kuhl, Alexander; Riepe, Matthias W.; Lohmann, Peter

    2006-01-01

    Impairment of hippocampal function precedes frontal and parietal cortex impairment in human Alzheimer's disease(AD). Neurotrophins are critical for behavioral performance and neuronal survival in AD. We used complex and radial mazes to assess spatial orientation and learning in wild-type and B6-Tg(ThylAPP)23Sdz (APP23) animals, a transgenic mouse…

  10. Adjuvant Surgical Oophorectomy Plus Tamoxifen in Premenopausal Women With Operable Hormone Receptor-Positive Breast Cancer: A Global Treatment Option.

    PubMed

    Love, Richard R

    2016-08-01

    One third of annual new cases of breast cancer globally are now hormone receptor-positive tumors in premenopausal women from low- and middle-income countries. For this subgroup of women with breast cancer, high-income country guidelines suggest impractical and unaffordable adjuvant treatments. The balance of clinical trial evidence now suggests that surgical oophorectomy plus tamoxifen is a safe and practical treatment for these women in low- and middle-income countries. Additionally, new randomized trial data suggest that women in the second half of an anovulatory cycle benefit minimally from surgical oophorectomy done at this time, which implies that regularly cycling women will benefit more than has been shown from this procedure. Allred scoring of levels of hormone receptors is a practical and inexpensive approach to the assessment of magnitudes of response to oophorectomy plus tamoxifen. These circumstances suggest that more detailed consideration of this option should characterize clinical practice guidelines in high-income countries because of their global impact. PMID:27117241

  11. Identification of Potential Glycoprotein Biomarkers in Estrogen Receptor Positive (ER+) and Negative (ER-) Human Breast Cancer Tissues by LC-LTQ/FT-ICR Mass Spectrometry

    PubMed Central

    Semaan, Suzan M.; Wang, Xu; Marshall, Alan G.; Sang, Qing-Xiang Amy

    2012-01-01

    Breast cancer is the second most fatal cancer in American women. To increase the life expectancy of patients with breast cancer new diagnostic and prognostic biomarkers and drug targets must be identified. A change in the glycosylation on a glycoprotein often causes a change in the function of that glycoprotein; such a phenomenon is correlated with cancerous transformation. Thus, glycoproteins in human breast cancer estrogen receptor positive (ER+) tissues and those in the more advanced stage of breast cancer, estrogen receptor negative (ER-) tissues, were compared. Glycoproteins showing differences in glycosylation were examined by 2-dimensional gel electrophoresis with double staining (glyco- and total protein staining) and identified by reversed-phase nano-liquid chromatography coupled with a hybrid linear quadrupole ion trap/ Fourier transform ion cyclotron resonance mass spectrometer. Among the identified glycosylated proteins are alpha 1 acid glycoprotein, alpha-1-antitrypsin, calmodulin, and superoxide dismutase mitochondrial precursor that were further verified by Western blotting for both ER+ and ER- human breast tissues. Results show the presence of a possible glycosylation difference in alpha-1-antitrypsin, a potential tumor-derived biomarker for breast cancer progression, which was expressed highest in the ER- samples. PMID:22773931

  12. NHE-RF, a Merlin-Interacting Protein, Is Primarily Expressed in Luminal Epithelia, Proliferative Endometrium, and Estrogen Receptor-Positive Breast Carcinomas

    PubMed Central

    Stemmer-Rachamimov, Anat O.; Wiederhold, Thorsten; Nielsen, G. Petur; James, Marianne; Pinney-Michalowski, Denise; Roy, Jennifer E.; Cohen, Wendy A.; Ramesh, Vijaya; Louis, David N.

    2001-01-01

    NHE-RF, a regulatory cofactor for NHE (Na+-H+ exchanger) type 3, interacts with ion transporters and receptors through its PDZ domains and with the MERM proteins (merlin, ezrin, radixin and moesin) via its carboxyl terminus. Thus, NHE-RF may act as a multifunctional adaptor protein and play a role in the assembly of signal transduction complexes, linking ion channels and receptors to the actin cytoskeleton. NHE-RF expression is up-regulated in response to estrogen in estrogen receptor-positive breast carcinoma cell lines, suggesting that it may be involved in estrogen signaling. To further understand NHE-RF function and its possible role in estrogen signaling, we analyzed NHE-RF expression in normal human tissues, including cycling endometrium, and in breast carcinomas, tissues in which estrogen plays an important role in regulating cell growth and proliferation. NHE-RF is expressed in many epithelia, especially in cells specialized in ion transport or absorption, and is often localized to apical (luminal) membranes. NHE-RF expression varies markedly in proliferative versus secretory endometrium, with high expression in proliferative (estrogen-stimulated) endometrium. Furthermore, estrogen receptor status and NHE-RF expression correlate closely in breast carcinoma specimens. These findings support a role for NHE-RF in estrogen signaling. PMID:11141479

  13. ( sup 111 In-DTPA-D-Phe sup 1 )-octreotide, a potential radiopharmaceutical for imaging of somatostatin receptor-positive tumors: Synthesis, radiolabeling and in vitro validation

    SciTech Connect

    Bakker, W.H.; Albert, R.; Bruns, C.; Breeman, W.A.P.; Hofland, L.J.; Marbach, P.; Pless, J.; Pralet, D.; Stolz, B.; Koper, J.W.; Lamberts, S.W.J.; Visser, T.J.; Krenning, E.P. Sandoz Pharma AG, Basel )

    1991-01-01

    As starting material for a potentially convenient radiopharmaceutical, a diethylenetriaminopentaacetic acid (DTPA) conjugated derivative of octreotide (SMS 201-995) was prepared. This peptide, (DTPA-D-Phe{sup 1})-octreotide (SDZ 215-811) binds more than 95% of added {sup 111}In in an easy, single-step labeling procedure without necessity of further purification. The specific somatostatin-like biologic effect of these analogues was proven by the inhibition of growth hormone secretion by cultured rat pituitary cells in a dose-dependent fashion by octreotide, (DTPA-D-Phe{sup 1})-octreotide and non-radioactive ({sup 115}In-DTPA-D-Phe{sup 1})-octreotide. The binding of ({sup 111}In-DTPA-D-Phe{sup 1})-octreotide to rat brain cortex membranes proved to be displaced similarly by natural somatosatin as well as by octreotide, suggesting specific binding of ({sup 111}In-DTPA-D-Phe{sup 1})-octreotide to somatostatin receptors. The binding of the indium-labeled compound showed a somewhat lower affinity when compared with the iodinated (Tyr{sup 3})-octreotide, but indium-labeled (DTPA-D-Phe{sup 1})-octreotide still binds with nanomolar affinity. In conjunction with in vivo studies, these results suggest that ({sup 111}In-DTPA-D-Phe{sup 1})-octreotide is a promising radiopharmaceutical for scintigraphic imaging of somatostatin receptor-positive tumors.

  14. Seribantumab, an Anti-ERBB3 Antibody, Delays the Onset of Resistance and Restores Sensitivity to Letrozole in an Estrogen Receptor-Positive Breast Cancer Model.

    PubMed

    Curley, Michael D; Sabnis, Gauri J; Wille, Lucia; Adiwijaya, Bambang S; Garcia, Gabriela; Moyo, Victor; Kazi, Armina A; Brodie, Angela; MacBeath, Gavin

    2015-11-01

    Heregulin-driven ERBB3 signaling has been implicated as a mechanism of resistance to cytotoxic and antiendocrine therapies in preclinical breast cancer models. In this study, we evaluated the effects of seribantumab (MM-121), a heregulin-blocking anti-ERBB3 monoclonal antibody, alone and in combination with the aromatase inhibitor letrozole, on cell signaling and tumor growth in a preclinical model of postmenopausal estrogen receptor-positive (ER(+)) breast cancer. In vitro, heregulin treatment induced estrogen receptor phosphorylation in MCF-7Ca cells, and long-term letrozole-treated (LTLT-Ca) cells had increased expression and activation levels of EGFR, HER2, and ERBB3. Treatment with seribantumab, but not letrozole, inhibited basal and heregulin-mediated ERBB receptor phosphorylation and downstream effector activation in letrozole-sensitive (MCF-7Ca) and -refractory (LTLT-Ca) cells. Notably, in MCF-7Ca-derived xenograft tumors, cotreatment with seribantumab and letrozole had increased antitumor activity compared with letrozole alone, which was accompanied by downregulated PI3K/MTOR signaling both prior to and after the development of resistance to letrozole. Moreover, the addition of an MTOR inhibitor to this treatment regimen did not improve antitumor activity and was not well tolerated. Our results demonstrate that heregulin-driven ERBB3 signaling mediates resistance to letrozole in a preclinical model of ER(+) breast cancer, suggesting that heregulin-expressing ER(+) breast cancer patients may benefit from the addition of seribantumab to antiendocrine therapy. PMID:26310543

  15. Peroxisome proliferator-activated receptor δ (PPARδ) induces estrogen receptor-positive mammary neoplasia through an inflammatory and metabolic phenotype linked to mTor activation

    PubMed Central

    Yuan, Hongyan; Lu, Jin; Xiao, Junfeng; Upadhyay, Geeta; Umans, Rachel; Kallakury, Bhaskar; Yin, Yuhzi; Fant, Michael E.; Kopelovich, Levy; Glazer, Robert I.

    2013-01-01

    The peroxisome proliferator-activated receptor-δ (PPARδ) regulates a multitude of physiological processes associated with glucose and lipid metabolism, inflammation and proliferation. One or more of these processes are potential risk factors for the ability of PPARδ agonists to promote tumorigenesis in the mammary gland. In the present study, we describe a new transgenic mouse model in which activation of PPARδ in the mammary epithelium by endogenous or synthetic ligands resulted in progressive histopathological changes that culminated in the appearance of estrogen receptor- and progesterone receptor-positive and ErbB2-negative infiltrating ductal carcinomas. Multiparous mice presented with mammary carcinomas after a latency of 12 months, and administration of the PPARδ ligand GW501516 reduced tumor latency to five months. Histopathological changes occurred concurrently with an increase in an inflammatory, invasive, metabolic and proliferative gene signature, including expression of the trophoblast gene, Plac1, beginning one week after GW501516 treatment, and remained elevated throughout tumorigenesis. The appearance of malignant changes correlated with a pronounced increase in phosphatidylcholine and lysophosphatidic acid metabolites, which coincided with activation of Akt and mTor signaling that were attenuated by treatment with the mTor inhibitor everolimus. Our findings are the first to demonstrate a direct role of PPARδ in the pathogenesis of mammary tumorigenesis, and suggest a rationale for therapeutic approaches to prevent and treat this disease. PMID:23811944

  16. Orally Active Metabotropic Glutamate Subtype 2 Receptor Positive Allosteric Modulators: Structure-Activity Relationships and Assessment in a Rat Model of Nicotine Dependence

    PubMed Central

    Sidique, Shyama; Dhanya, Raveendra-Panickar; Sheffler, Douglas J.; Nickols, Hilary Highfield; Yang, Li; Dahl, Russell; Mangravita-Novo, Arianna; Smith, Layton H.; D’Souza, Manoranjan S.; Semenova, Svetlana; Conn, P. Jeffrey; Markou, Athina; Cosford, Nicholas D. P.

    2012-01-01

    Compounds that modulate metabotropic glutamate subtype 2 (mGlu2) receptors have the potential to treat several disorders of the central nervous system (CNS) including drug dependence. Herein we describe the synthesis and structure-activity relationship (SAR) studies around a series of mGlu2 receptor positive allosteric modulators (PAMs). The effects of N-substitution (R1) and substitutions on the aryl ring (R2) were identified as key areas for SAR exploration (Figure 3). Investigation of the effects of varying substituents in both the isoindolinone (2) and benzisothiazolone (3) series led to compounds with improved in vitro potency and/or efficacy. In addition, several analogues exhibited promising pharmacokinetic (PK) properties. Furthermore, compound 2 was shown to dose-dependently decrease nicotine self-administration in rats following oral administration. Our data, showing for the first time efficacy of an mGlu2 receptor PAM in this in vivo model, suggest potential utility for the treatment of nicotine dependence in humans. PMID:23009245

  17. Oxidative stress-mediated apoptosis induced by ethanolic mango seed extract in cultured estrogen receptor positive breast cancer MCF-7 cells.

    PubMed

    Abdullah, Al-Shwyeh Hussah; Mohammed, Abdulkarim Sabo; Rasedee, Abdullah; Mirghani, Mohamed Elwathig Saeed

    2015-01-01

    Breast cancer has become a global health issue requiring huge expenditures for care and treatment of patients. There is a need to discover newer cost-effective alternatives for current therapeutic regimes. Mango kernel is a waste product with potential as a source of anti-cancer phytochemicals, especially since it is non-toxic towards normal breast cell lines at concentrations for which it induces cell death in breast cancer cells. In this study, the anti-cancer effect of mango kernel extract was determined on estrogen receptor-positive human breast carcinoma (MCF-7) cells. The MCF-7 cells were cultured and treated with 5, 10 and 50 μg/mL of mango kernel extract for 12 and 24 h. In response to treatment, there were time- and dose-dependent increases in oxidative stress markers and pro-apoptotic factors; Bcl-2-like protein 4 (BAX), p53, cytochrome c and caspases (7, 8 and 9) in the MCF-7 cells treated with the extract. At the same time, there were decreases in pro-survival markers (Bcl-2 and glutathione) as the result of the treatments. The changes induced in the MCF-7 cells by mango kernel extract treatment suggest that the extract can induce cancer cell apoptosis, likely via the activation of oxidative stress. These findings need to be evaluated further to determine whether mango kernel extract can be developed as an anti-breast cancer agent. PMID:25664859

  18. Testicular Expression of NGF, TrkA and p75 During Seasonal Spermatogenesis of the Wild Ground Squirrel (Citellus Dauricus Brandt)

    PubMed Central

    Zhang, H.; Wang, Y.; Zhan, J.; Wang, L.; Li, Q.; Sheng, X.; Han, Y.; Yuan, Z.; Weng, Q.

    2015-01-01

    The nerve growth factor (NGF) not only has an essential effect on the nervous system, but also plays an important role in a variety of non-neuronal systems, such as the reproductive system. The aim of this study was to compare the quality and quantity in expression of NGF and its receptors (TrkA and p75) in testes of the wild ground squirrel during the breeding and nonbreeding seasons. Immunolocalization for NGF was detected mainly in Leydig cells and Sertoli cells in testes of the breeding and nonbreeding seasons. The immunoreactivity of TrkA was highest in the elongated spermatids, whereas p75 in spermatogonia and spermatocytes in testes of the breeding season. In the nonbreeding season testes, TrkA showed positive immunostainings in Leydig cells, spermatogonia and primary spermatocytes, while p75 showed positive signals in spermatogonia and primary spermatocytes. Consistent with the immunohistochemical results, the mean mRNA and protein level of NGF and TrkA were higher in the testes of the breeding season than in non-breeding season, and then decreased to a relatively low level in the nonbreeding season. In addition, the concentration of plasma gonadotropins and testosterone were assayed by radioimmunoassay (RIA), and the results showed a significant difference between the breeding and nonbreeding seasons with higher concentrations in breeding season. In conclusion, these results of this study provide the first evidence on the potential involvement of NGF and its receptor, TrkA and p75 in the seasonal spermatogenesis and testicular function change of the wild ground squirrel. PMID:26428886

  19. Involvement of TrkB- and p75NTR-signaling pathways in two contrasting forms of long-lasting synaptic plasticity

    PubMed Central

    Sakuragi, Shigeo; Tominaga-Yoshino, Keiko; Ogura, Akihiko

    2013-01-01

    The repetition of experience is often necessary to establish long-lasting memory. However, the cellular mechanisms underlying this repetition-dependent consolidation of memory remain unclear. We previously observed in organotypic slice cultures of the rodent hippocampus that repeated inductions of long-term potentiation (LTP) led to a slowly developing long-lasting synaptic enhancement coupled with synaptogenesis. We also reported that repeated inductions of long-term depression (LTD) produced a long-lasting synaptic suppression coupled with synapse elimination. We proposed these phenomena as useful in vitro models for analyzing repetition-dependent consolidation. Here, we hypothesized that the enhancement and suppression are mediated by the brain-derived neurotrophic factor (BDNF)-TrkB signaling pathway and the proBDNF-p75NTR pathway, respectively. When we masked the respective pathways, reversals of the enhancement and suppression resulted. These results suggest the alternative activation of the p75NTR pathway by BDNF under TrkB-masking conditions and of the TrkB pathway by proBDNF under p75NTR-masking conditions, thus supporting the aforementioned hypothesis. PMID:24212565

  20. Small-Molecule Inhibitors of the LEDGF/p75 Binding Site of Integrase Block HIV Replication and Modulate Integrase Multimerization

    PubMed Central

    Christ, Frauke; Shaw, Stephen; Demeulemeester, Jonas; Desimmie, Belete A.; Marchand, Arnaud; Butler, Scott; Smets, Wim; Chaltin, Patrick; Westby, Mike

    2012-01-01

    Targeting the HIV integrase (HIV IN) is a clinically validated approach for designing novel anti-HIV therapies. We have previously described the discovery of a novel class of integration inhibitors, 2-(quinolin-3-yl)acetic acid derivatives, blocking HIV replication at a low micromolar concentration through binding in the LEDGF/p75 binding pocket of HIV integrase, hence referred to as LEDGINs. Here we report the detailed characterization of their mode of action. The design of novel and more potent analogues with nanomolar activity enabled full virological evaluation and a profound mechanistic study. As allosteric inhibitors, LEDGINs bind to the LEDGF/p75 binding pocket in integrase, thereby blocking the interaction with LEDGF/p75 and interfering indirectly with the catalytic activity of integrase. Detailed mechanism-of-action studies reveal that the allosteric mode of inhibition is likely caused by an effect on HIV-1 integrase oligomerization. The multimodal inhibition by LEDGINs results in a block in HIV integration and in a replication deficiency of progeny virus. The allosteric nature of LEDGINs leads to synergy in combination with the clinically approved active site HIV IN strand transfer inhibitor (INSTI) raltegravir, and cross-resistance profiling proves the distinct mode of action of LEDGINs and INSTIs. The allosteric nature of inhibition and compatibility with INSTIs underline an interest in further (clinical) development of LEDGINs. PMID:22664975

  1. Involvement of TrkB- and p75NTR-signaling pathways in two contrasting forms of long-lasting synaptic plasticity

    NASA Astrophysics Data System (ADS)

    Sakuragi, Shigeo; Tominaga-Yoshino, Keiko; Ogura, Akihiko

    2013-11-01

    The repetition of experience is often necessary to establish long-lasting memory. However, the cellular mechanisms underlying this repetition-dependent consolidation of memory remain unclear. We previously observed in organotypic slice cultures of the rodent hippocampus that repeated inductions of long-term potentiation (LTP) led to a slowly developing long-lasting synaptic enhancement coupled with synaptogenesis. We also reported that repeated inductions of long-term depression (LTD) produced a long-lasting synaptic suppression coupled with synapse elimination. We proposed these phenomena as useful in vitro models for analyzing repetition-dependent consolidation. Here, we hypothesized that the enhancement and suppression are mediated by the brain-derived neurotrophic factor (BDNF)-TrkB signaling pathway and the proBDNF-p75NTR pathway, respectively. When we masked the respective pathways, reversals of the enhancement and suppression resulted. These results suggest the alternative activation of the p75NTR pathway by BDNF under TrkB-masking conditions and of the TrkB pathway by proBDNF under p75NTR-masking conditions, thus supporting the aforementioned hypothesis.

  2. Neurotrophin-4 is up-regulated in ragged-red fibers associated with pathogenic mitochondrial DNA mutations.

    PubMed

    Walker, U A; Schon, E A

    1998-04-01

    Ragged-red fibers (RRFs) are found more frequently in highly oxidative type I fibers than in glycolytic type II fibers in the muscle of many patients with mitochondrial myopathies. Neurotrophin-4 (NT-4), a neuronal signaling molecule, is also expressed in skeletal muscle, predominantly in type I fibers. We found that NT-4 protein and mRNA were present in both type I and type II fibers but were up-regulated in RRFs of patients with mitochondrial encephalomyopathies; it is noteworthy that NT-4 was not up-regulated in muscle fibers from healthy aerobically trained athletes. Thus, NT-4 might represent a member of a new class of candidate molecules involved in the compensatory adjustments of muscle fibers to oxidative dysfunction, and may even play a role as a signaling molecule for mitochondrial proliferation. PMID:9546339

  3. RCAN1 links impaired neurotrophin trafficking to aberrant development of the sympathetic nervous system in Down syndrome

    PubMed Central

    Patel, Ami; Yamashita, Naoya; Ascaño, Maria; Bodmer, Daniel; Boehm, Erica; Bodkin-Clarke, Chantal; Ryu, Yun Kyoung; Kuruvilla, Rejji

    2015-01-01

    Down syndrome is the most common chromosomal disorder affecting the nervous system in humans. To date, investigations of neural anomalies in Down syndrome have focused on the central nervous system, although dysfunction of the peripheral nervous system is a common manifestation. The molecular and cellular bases underlying peripheral abnormalities have remained undefined. Here, we report the developmental loss of sympathetic innervation in human Down syndrome organs and in a mouse model. We show that excess regulator of calcineurin 1 (RCAN1), an endogenous inhibitor of the calcineurin phosphatase that is triplicated in Down syndrome, impairs neurotrophic support of sympathetic neurons by inhibiting endocytosis of the nerve growth factor (NGF) receptor, TrkA. Genetically correcting RCAN1 levels in Down syndrome mice markedly improves NGF-dependent receptor trafficking, neuronal survival and innervation. These results uncover a critical link between calcineurin signalling, impaired neurotrophin trafficking and neurodevelopmental deficits in the peripheral nervous system in Down syndrome. PMID:26658127

  4. Postnatal exposure to trichloroethylene alters glutathione redox homeostasis, methylation potential, and neurotrophin expression in the mouse hippocampus

    PubMed Central

    Blossom, Sarah J.; Melnyk, Stepan; Cooney, Craig A.; Gilbert, Kathleen M.; James, S. Jill

    2012-01-01

    Previous studies have shown that continuous exposure throughout gestation until the juvenile period to environmentally-relevant doses of trichloroethylene (TCE) in the drinking water of MRL+/+ mice promoted adverse behavior associated with glutathione depletion in the cerebellum indicating increased sensitivity to oxidative stress. The purpose of this study was to extend our findings and further characterize the impact of TCE exposure on redox homeostasis and biomarkers of oxidative stress in the hippocampus, a brain region prone to oxidative stress. Instead of a continuous exposure, the mice were exposed to water only or two environmentally relevant doses of TCE in the drinking water postnatally from birth until 6 weeks of age. Biomarkers of plasma metabolites in the transsulfuration pathway and the transmethylation pathway of the methionine cycle were also examined. Gene expression of neurotrophins was examined to investigate a possible relationship between oxidative stress, redox imbalance and neurotrophic factor expression with TCE exposure. Our results show that hippocampi isolated from male mice exposed to TCE showed altered glutathione redox homeostasis indicating a more oxidized state. Also observed was a significant, dose dependent increase in glutathione precursors. Plasma from the TCE treated mice showed alterations in metabolites in the transsulfuration and transmethylation pathways indicating redox imbalance and altered methylation capacity. 3-Nitrotyrosine, a biomarker of protein oxidative stress, was also significantly higher in plasma and hippocampus of TCE-exposed mice compared to controls. In contrast, expression of key neurotrophic factors in the hippocampus (BDNF, NGF, and NT-3) was significantly reduced compared to controls. Our results demonstrate that low-level postnatal and early life TCE exposure modulates neurotrophin gene expression in the mouse hippocampus and may provide a mechanism for TCE-mediated neurotoxicity. PMID:22421312

  5. Combination of Engineered Schwann Cell Grafts to Secrete Neurotrophin and Chondroitinase Promotes Axonal Regeneration and Locomotion after Spinal Cord Injury

    PubMed Central

    Pressman, Yelena; Moody, Alison; Berg, Randall; Muir, Elizabeth M.; Rogers, John H.; Ozawa, Hiroshi; Itoi, Eiji; Pearse, Damien D.; Bunge, Mary Bartlett

    2014-01-01

    Transplantation of Schwann cells (SCs) is a promising therapeutic strategy for spinal cord repair. SCs introduced into lesions support axon regeneration, but because these axons do not exit the transplant, additional approaches with SCs are needed. Here, we transplanted SCs genetically modified to secrete a bifunctional neurotrophin (D15A) and chondroitinase ABC (ChABC) into a subacute contusion injury in rats. We examined the effects of these modifications on graft volume, SC number, degradation of chondroitin sulfate proteoglycans (CSPGs), astrogliosis, SC myelination of axons, propriospinal and supraspinal axon numbers, locomotor outcome (BBB scoring, CatWalk gait analysis), and mechanical and thermal sensitivity on the hind paws. D15A secreted from transplanted SCs increased graft volume and SC number and myelinated axon number. SCs secreting ChABC significantly decreased CSPGs, led to some egress of SCs from the graft, and increased propriospinal and 5-HT-positive axons in the graft. SCs secreting both D15A and ChABC yielded the best responses: (1) the largest number of SC myelinated axons, (2) more propriospinal axons in the graft and host tissue around and caudal to it, (3) more corticospinal axons closer to the graft and around and caudal to it, (4) more brainstem neurons projecting caudal to the transplant, (5) increased 5-HT-positive axons in the graft and caudal to it, (6) significant improvement in aspects of locomotion, and (7) improvement in mechanical and thermal allodynia. This is the first evidence that the combination of SC transplants engineered to secrete neurotrophin and chondroitinase further improves axonal regeneration and locomotor and sensory function. PMID:24478364

  6. The Role of Leptin, Melanocortin, and Neurotrophin System Genes on Body Weight in Anorexia Nervosa and Bulimia Nervosa

    PubMed Central

    Yilmaz, Zeynep; Kaplan, Allan S.; Tiwari, Arun K.; Levitan, Robert D.; Piran, Sara; Bergen, Andrew W.; Kaye, Walter H.; Hakonarson, Hakon; Wang, Kai; Berrettini, Wade H.; Brandt, Harry A.; Bulik, Cynthia M.; Crawford, Steve; Crow, Scott; Fichter, Manfred M.; Halmi, Katherine A.; Johnson, Craig L.; Keel, Pamela K.; Klump, Kelly L.; Magistretti, Pierre; Mitchell, James E.; Strober, Michael; Thornton, Laura M.; Treasure, Janet; Woodside, D. Blake; Knight, Joanne; Kennedy, James L.

    2014-01-01

    Objective Although low weight is a key factor contributing to the high mortality in anorexia nervosa (AN), it is unclear how AN patients sustain low weight compared with bulimia nervosa (BN) patients with similar psychopathology. Studies of genes involved in appetite and weight regulation in eating disorders have yielded variable findings in part due to small sample size and clinical heterogeneity. This study: (1) assessed the role of leptin, melanocortin, and neurotrophin genetic variants in conferring risk for AN and BN and (2) explored the involvement of these genes in body mass index (BMI) variations within AN and BN. Method Our sample consisted of 745 individuals with AN without a history of BN, 245 with BN without a history of AN, and 321 controls. We genotyped 20 markers with known or putative function among genes selected from leptin, melanocortin, and neurotrophin systems. Results There were no significant differences in allele frequencies among individuals with AN, BN, and controls. AGRP rs13338499 polymorphism was associated with lowest illness-related BMI in those with AN (p=0.0013), and NTRK2 rs1042571 was associated with highest BMI in those with BN (p=0.0018). Discussion To our knowledge, this is the first study to address the issue of clinical heterogeneity in eating disorder genetics and to explore the role of known or putatively functional markers in genes regulating appetite and weight in individuals with AN and BN. If replicated, our results may serve as an important first step toward gaining a better understanding of weight regulation in eating disorders. PMID:24831852

  7. Caffeic Acid Phenethyl Ester Increases Radiosensitivity of Estrogen Receptor-Positive and -Negative Breast Cancer Cells by Prolonging Radiation-Induced DNA Damage

    PubMed Central

    Khoram, Nastaran Masoudi; Bigdeli, Bahareh; Nikoofar, Alireza

    2016-01-01

    Purpose Breast cancer is an important cause of death among women. The development of radioresistance in breast cancer leads to recurrence after radiotherapy. Caffeic acid phenethyl ester (CAPE), a polyphenolic compound of honeybee propolis, is known to have anticancer properties. In this study, we examined whether CAPE enhanced the radiation sensitivity of MDA-MB-231 (estrogen receptor-negative) and T47D (estrogen receptor-positive) cell lines. Methods The cytotoxic effect of CAPE on MDA-MB-231 and T47D breast cancer cells was evaluated by performing an 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay. To assess clonogenic ability, MDA-MB-231 and T47D cells were treated with CAPE (1 µM) for 72 hours before irradiation, and then, a colony assay was performed. A comet assay was used to determine the number of DNA strand breaks at four different times. Results CAPE decreased the viability of both cell lines in a dose- and time-dependent manner. In the clonogenic assay, pretreatment of cells with CAPE before irradiation significantly reduced the surviving fraction of MDA-MB-231 cells at doses of 6 and 8 Gy. A reduction in the surviving fraction of T47D cells was observed relative to MDA-MB-231 at lower doses of radiation. Additionally, CAPE maintained radiation-induced DNA damage in T47D cells for a longer period than in MDA-MB-231 cells. Conclusion Our results indicate that CAPE impairs DNA damage repair immediately after irradiation. The induction of radiosensitivity by CAPE in radioresistant breast cancer cells may be caused by prolonged DNA damage. PMID:27066092

  8. Shu-Gan-Liang-Xue Decoction Simultaneously Down-regulates Expressions of Aromatase and Steroid Sulfatase in Estrogen Receptor Positive Breast Cancer Cells

    PubMed Central

    Fu, Xue-song; Li, Ping-ping

    2011-01-01

    Objective Estradiol (E2) plays an important role in the development of breast cancer. In postmenopausal women, the estrogen can be synthesized via aromatase (CYP19) pathway and steroid-sulfatase (STS) pathway in peripheral tissues, when the production in ovary has ceased. The objective of our study was to explore the effects of Shu-Gan-Liang-Xue Decoction (SGLXD) on the expressions of CYP19 and STS in estrogen receptor positive breast cancer MCF-7 and T47D cells. Methods The effects of SGLXD on the cell viability of MCF-7 and T47D were analyzed by MTT assay. By quantitative real-time RT-PCR and Western blot, we evaluated the mRNA and protein expressions of CYP19 and STS in MCF-7 and T47D cells after SGLXD treatment. Results By MTT assay, the cell viability rates of MCF-7 and T47D were significantly inhibited by SGLXD in a dose-dependent manner, the IC50 values were 40.07 mg/ml for MCF-7 cells and 25.62 mg/ml for T47D cells, respectively. As evidenced by real-time PCR and Western blot, the high concentrations of SGLXD significantly down-regulated the expressions of CYP19 and STS both in the transcript level and the protein level. Conclusion The results suggest that SGLXD is a potential dual aromatase-sulfatase inhibitor by simultaneously down-regulating the expressions of CYP19 and STS in MCF-7 and T47D cells. PMID:23467843

  9. Antiproliferative activity and induction of apoptosis in estrogen receptor-positive and negative human breast carcinoma cell lines by Gmelina asiatica roots

    PubMed Central

    Balijepalli, Madhu Katyayani; Tandra, Satyanarayana; Pichika, Mallikarjuna Rao

    2010-01-01

    Low risk of breast cancer has been proposed to be associated with high intake of lignans. We have reported the presence of lignans in Gmelina asiatica roots. There are no scientific reports on the antiproliferative activity of G. asiatica roots. The objective of the present study was to evaluate the effect of ethyl acetate extract from G. asiatica roots (EGAR) on estrogen receptor-positive (MCF-7) and negative (MDA-MB-231) human breast cancer cell lines. The effects of 50% inhibitory concentrations (IC50) of EGAR on MCF-7 and MDA-MB-231 cells were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay kit. The mode of cell death caused by EGAR was determined using dual apoptosis assay kit by observing the cells under fluorescent microscope. The quantification of apoptosis and necrosis in cells caused by EGAR was determined using cell death detection kit through ELISA. Down-regulation of the proliferative activity occurred in a clear dose-dependent response with IC50 values of 32.9 ± 3.8 μg/mL in MCF-7 and 19.9 ± 2.3 μg/mL in MDA-MB-231 cell lines. Treatment of breast cancer cells with EGAR resulted in significant apoptosis. The EGAR contain lignans and flavonoids. The antiproliferative activity of the extract is attributed to the presence of these secondary metabolites. The results suggest the efficacy of G. asiatica roots as antiproliferative agents on human breast cancer cells, supporting the hypothesis that plants containing lignans have beneficial effects on human breast cancer. PMID:21808551

  10. Incidence and time course of everolimus-related adverse events in postmenopausal women with hormone receptor-positive advanced breast cancer: insights from BOLERO-2

    PubMed Central

    Rugo, H. S.; Pritchard, K. I.; Gnant, M.; Noguchi, S.; Piccart, M.; Hortobagyi, G.; Baselga, J.; Perez, A.; Geberth, M.; Csoszi, T.; Chouinard, E.; Srimuninnimit, V.; Puttawibul, P.; Eakle, J.; Feng, W.; Bauly, H.; El-Hashimy, M.; Taran, T.; Burris, H. A.

    2014-01-01

    Background In the BOLERO-2 trial, everolimus (EVE), an inhibitor of mammalian target of rapamycin, demonstrated significant clinical benefit with an acceptable safety profile when administered with exemestane (EXE) in postmenopausal women with hormone receptor-positive (HR+) advanced breast cancer. We report on the incidence, time course, severity, and resolution of treatment-emergent adverse events (AEs) as well as incidence of dose modifications during the extended follow-up of this study. Patients and methods Patients were randomized (2:1) to receive EVE 10 mg/day or placebo (PBO), with open-label EXE 25 mg/day (n = 724). The primary end point was progression-free survival. Secondary end points included overall survival, objective response rate, and safety. Safety evaluations included recording of AEs, laboratory values, dose interruptions/adjustments, and study drug discontinuations. Results The safety population comprised 720 patients (EVE + EXE, 482; PBO + EXE, 238). The median follow-up was 18 months. Class-effect toxicities, including stomatitis, pneumonitis, and hyperglycemia, were generally of mild or moderate severity and occurred relatively early after treatment initiation (except pneumonitis); incidence tapered off thereafter. EVE dose reduction and interruption (360 and 705 events, respectively) required for AE management were independent of patient age. The median duration of dose interruption was 7 days. Discontinuation of both study drugs because of AEs was higher with EVE + EXE (9%) versus PBO + EXE (3%). Conclusions Most EVE-associated AEs occur soon after initiation of therapy, are typically of mild or moderate severity, and are generally manageable with dose reduction and interruption. Discontinuation due to toxicity was uncommon. Understanding the time course of class-effect AEs will help inform preventive and monitoring strategies as well as patient education. Trial registration number NCT00863655. PMID:24615500

  11. Multi-field-of-view strategy for image-based outcome prediction of multi-parametric estrogen receptor-positive breast cancer histopathology: Comparison to Oncotype DX.

    PubMed

    Basavanhally, Ajay; Feldman, Michael; Shih, Natalie; Mies, Carolyn; Tomaszewski, John; Ganesan, Shridar; Madabhushi, Anant

    2011-01-01

    In this paper, we attempt to quantify the prognostic information embedded in multi-parametric histologic biopsy images to predict disease aggressiveness in estrogen receptor-positive (ER+) breast cancers (BCa). The novel methodological contribution is in the use of a multi-field-of-view (multi-FOV) framework for integrating image-based information from differently stained histopathology slides. The multi-FOV approach involves a fixed image resolution while simultaneously integrating image descriptors from many FOVs corresponding to different sizes. For each study, the corresponding risk score (high scores reflecting aggressive disease and vice versa), predicted by a molecular assay (Oncotype DX), is available and serves as the surrogate ground truth for long-term patient outcome. Using the risk scores, a trained classifier is used to identify disease aggressiveness for each FOV size. The predictions for each FOV are then combined to yield the final prediction of disease aggressiveness (good, intermediate, or poor outcome). Independent multi-FOV classifiers are constructed for (1) 50 image features describing the spatial arrangement of cancer nuclei (via Voronoi diagram, Delaunay triangulation, and minimum spanning tree graphs) in H and E stained histopathology and (2) one image feature describing the vascular density in CD34 IHC stained histopathology. In a cohort of 29 patients, the multi-FOV classifiers obtained by combining information from the H and E and CD34 IHC stained channels were able to distinguish low- and high-risk patients with an accuracy of 0.91 ± 0.02 and a positive predictive value of 0.94 ± 0.10, suggesting that a purely image-based assay could potentially replace more expensive molecular assays for making disease prognostic predictions. PMID:22811953

  12. CDK9 inhibitors selectively target estrogen receptor-positive breast cancer cells through combined inhibition of MYB and MCL-1 expression

    PubMed Central

    Mitra, Partha; Yang, Ren-Ming; Sutton, James; Ramsay, Robert G.; Gonda, Thomas J.

    2016-01-01

    Our previous studies showed that MYB is required for proliferation of, and confers protection against apoptosis on, estrogen receptor-positive (ER+ve) breast cancer cells, which are almost invariably also MYB+ve. We have also shown that MYB expression in ER+ve breast cancer cells is regulated at the level of transcriptional elongation and as such, is suppressed by CDK9i. Here we examined the effects of CDK9i on breast cancer cells and the involvement of MYB in these effects. ER+ve breast cancer cell lines including MCF-7 were much more sensitive (> 10 times) to killing by CDK9i than ER−ve/MYB−ve cells. Moreover, surviving cells showed a block at the G2/M phase of the cell cycle. Importantly, ectopic MYB expression conferred resistance to apoptosis induction, cell killing and G2/M accumulation. Expression of relevant MYB target genes including BCL2 and CCNB1 was suppressed by CDK9 inhibition, and this too was reversed by ectopic MYB expression. Nevertheless, inhibition of BCL2 alone either by MYB knockdown or by ABT-199 treatment was insufficient for significant induction of apoptosis. Further studies implied that suppression of MCL-1, a well-documented target of CDK9 inhibition, was additionally required for apoptosis induction, while maximal levels of apoptosis induced by CDK9i are likely to also involve inhibition of BCL2L1 expression. Taken together these data suggest that MYB regulation of BCL2 underlies the heightened sensitivity of ER+ve compared to ER−ve breast cancer cells to CDK9 inhibition, and that these compounds represent a potential therapeutic for ER+ve breast cancers and possibly other MYB-dependent cancers. PMID:26812885

  13. Efficacy and safety of an adjunctive mGlu2 receptor positive allosteric modulator to a SSRI/SNRI in anxious depression.

    PubMed

    Kent, Justine M; Daly, Ella; Kezic, Iva; Lane, Rosanne; Lim, Pilar; De Smedt, Heidi; De Boer, Peter; Van Nueten, Luc; Drevets, Wayne C; Ceusters, Marc

    2016-06-01

    This phase 2a, randomized, multicenter, double-blind, proof-of-concept study was designed to evaluate, efficacy, safety and tolerability of JNJ-40411813/ADX71149, a novel metabotropic glutamate 2 receptor positive allosteric modulator as an adjunctive treatment for major depressive disorder (MDD) with significant anxiety symptoms. Eligible patients (18-64years) had a DSM-IV diagnosis of MDD, Hamilton Depression Rating Scale-17 (HDRS17) score of ≥18, HDRS17 anxiety/somatization factor score of ≥7, and an insufficient response to current treatment with a selective serotonin reuptake inhibitor or serotonin-norepinephrine reuptake inhibitor. The doubly-randomized, 8-week double-blind treatment phase was comprised of two 4-week periods, from which a combined test statistic was generated, with pre-determined weights assigned to each of the 2 treatment periods. Period 1: patients (n=121) were randomly assigned (1:1) to JNJ-40411813 (n=62; 50mg to 150mg b.i.d, flexibly dosed) or placebo (n=59); Period 2: placebo-treated patients (n=22) who continued to meet entry severity criteria were re-randomized (1:1) to JNJ-40411813 or placebo, while other patients underwent sham re-randomization and continued on their same treatment. Of 121 randomized patients, 100 patients (82.6%) were completers. No efficacy signal was detected on the primary endpoint, the 6-item Hamilton Anxiety Subscale (HAM-A6, p=0.51). Efficacy signals (based on prespecified 1-sided p<0.20) were evident on several secondary outcome measures of both depression (HDRS17 total score, 6-item subscale of HDRS17 assessing core depressive symptoms [HAM-D6], and Inventory of Depressive Symptomatology [IDS-C30]) and anxiety (HDRS17 anxiety/somatization factor, IDS-C30 anxiety subscale). Although well-tolerated, the results do not suggest efficacy for JNJ-40411813 as an adjunctive treatment for patients with MDD with significant anxious symptoms in the dose range studied. PMID:26804646

  14. CYP19A1 polymorphisms and clinical outcomes in postmenopausal women with hormone receptor-positive breast cancer in the BIG 1–98 trial

    PubMed Central

    Gray, Kathryn P.; Abramovitz, Mark; Bouzyk, Mark; Young, Brandon; Long, Bradley; Kammler, Roswitha; Dell'Orto, Patrizia; Biasi, Maria Olivia; Thürlimann, Beat; Lyng, Maria B.; Ditzel, Henrik J.; Harvey, Vernon J.; Neven, Patrick; Treilleux, Isabelle; Rasmussen, Birgitte Bruun; Maibach, Rudolf; Price, Karen N.; Coates, Alan S.; Goldhirsch, Aron; Pagani, Olivia; Viale, Giuseppe; Rae, James M.; Regan, Meredith M.

    2016-01-01

    To determine whether CYP19A1 polymorphisms are associated with abnormal activity of aromatase and with musculoskeletal and bone side effects of aromatase inhibitors. DNA was isolated from tumor specimens of 4861 postmenopausal women with hormone receptor-positive breast cancer enrolled in the BIG 1–98 trial to receive tamoxifen and/or letrozole for 5 years. Tumors were genotyped for six CYP19A1 polymorphisms using PCR-based methods. Associations with breast cancer-free interval (BCFI), distant recurrence-free interval (DRFI), musculoskeletal and bone adverse events (AEs) were assessed using Cox proportional hazards models. All statistical tests were two-sided. No association between the CYP19A1 genotypes and BCFI or DRFI was observed overall. A reduced risk of a breast cancer event for tamoxifen-treated patients with rs700518 variants was observed (BCFI CC/TC vs. TT: HR 0.53, 95 % CI 0.34–0.82, interaction P = 0.08), but not observed for letrozole-treated patients. There was an increased risk of musculoskeletal AEs for patients with rs700518 variants CC/TC versus TT (HR 1.22, 95 % CI 1.03–1.45, P = 0.02), regardless of treatment. Tamoxifen-treated patients with rs4646 variants had a reduced risk of bone AEs (AA/CA vs. CC: HR 0.76, 95 % CI 0.59–0.98), whereas an increase of minor allele (C) of rs10046 was associated with an increased risk of bone AEs (HR 1.28, 95 % CI 1.07–1.52). rs936308 variants were associated with a reduced risk of bone AEs in letrozole-treated patients (GG/GC vs. CC: HR 0.73, 95 % CI 0.54–0.99), different from in tamoxifen-treated patients (GG/GC vs. CC: HR 1.32, 95 % CI 0.92–1.90, interaction P = 0.01). CYP19A1 rs700518 variants showed associations with BCFI, DRFI, in tamoxifen treated patients and musculoskeletal AEs regardless of treatment. SNPs rs4646, rs10046, and rs936308 were associated with bone AEs. PMID:25935582

  15. CYP19A1 polymorphisms and clinical outcomes in postmenopausal women with hormone receptor-positive breast cancer in the BIG 1-98 trial.

    PubMed

    Leyland-Jones, Brian; Gray, Kathryn P; Abramovitz, Mark; Bouzyk, Mark; Young, Brandon; Long, Bradley; Kammler, Roswitha; Dell'Orto, Patrizia; Biasi, Maria Olivia; Thürlimann, Beat; Lyng, Maria B; Ditzel, Henrik J; Harvey, Vernon J; Neven, Patrick; Treilleux, Isabelle; Rasmussen, Birgitte Bruun; Maibach, Rudolf; Price, Karen N; Coates, Alan S; Goldhirsch, Aron; Pagani, Olivia; Viale, Giuseppe; Rae, James M; Regan, Meredith M

    2015-06-01

    To determine whether CYP19A1 polymorphisms are associated with abnormal activity of aromatase and with musculoskeletal and bone side effects of aromatase inhibitors. DNA was isolated from tumor specimens of 4861 postmenopausal women with hormone receptor-positive breast cancer enrolled in the BIG 1-98 trial to receive tamoxifen and/or letrozole for 5 years. Tumors were genotyped for six CYP19A1 polymorphisms using PCR-based methods. Associations with breast cancer-free interval (BCFI), distant recurrence-free interval (DRFI), musculoskeletal and bone adverse events (AEs) were assessed using Cox proportional hazards models. All statistical tests were two-sided. No association between the CYP19A1 genotypes and BCFI or DRFI was observed overall. A reduced risk of a breast cancer event for tamoxifen-treated patients with rs700518 variants was observed (BCFI CC/TC vs. TT: HR 0.53, 95 % CI 0.34-0.82, interaction P = 0.08), but not observed for letrozole-treated patients. There was an increased risk of musculoskeletal AEs for patients with rs700518 variants CC/TC versus TT (HR 1.22, 95 % CI 1.03-1.45, P = 0.02), regardless of treatment. Tamoxifen-treated patients with rs4646 variants had a reduced risk of bone AEs (AA/CA vs. CC: HR 0.76, 95 % CI 0.59-0.98), whereas an increase of minor allele (C) of rs10046 was associated with an increased risk of bone AEs (HR 1.28, 95 % CI 1.07-1.52). rs936308 variants were associated with a reduced risk of bone AEs in letrozole-treated patients (GG/GC vs. CC: HR 0.73, 95 % CI 0.54-0.99), different from in tamoxifen-treated patients (GG/GC vs. CC: HR 1.32, 95 % CI 0.92-1.90, interaction P = 0.01). CYP19A1 rs700518 variants showed associations with BCFI, DRFI, in tamoxifen treated patients and musculoskeletal AEs regardless of treatment. SNPs rs4646, rs10046, and rs936308 were associated with bone AEs. PMID:25935582

  16. (±)3,4-Methylenedioxymethamphetamine (“Ecstasy”) Treatment Modulates Expression of Neurotrophins and Their Receptors in Multiple Regions of Adult Rat Brain

    PubMed Central

    Hemmerle, Ann M.; Dickerson, Jonathan W.; Herring, Nicole R.; Schaefer, Tori L.; Vorhees, Charles V.; Williams, Michael T.; Seroogy, Kim B.

    2014-01-01

    (±)3,4-Methylenedioxymethamphetamine (MDMA), a widely used drug of abuse, rapidly reduces serotonin levels in the brain when ingested or administered in sufficient quantities, resulting in deficits in complex route-based learning, spatial learning, and reference memory. Neurotrophins are important for survival and preservation of neurons in the adult brain, including serotonergic neurons. In this study, we examined the effects of MDMA on the expression of brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) and their respective high-affinity receptors, tropomyosin receptor kinase (trk)B and trkC, in multiple regions of the rat brain. A serotonergic-depleting dose of MDMA (10 mg/kg × 4 at 2-hour intervals on a single day) was administered to adult Sprague-Dawley rats, and brains were examined 1, 7, or 24 hours after the last dose. Messenger RNA levels of BDNF, NT-3, trkB, and trkC were analyzed by using in situ hybridization with cRNA probes. The prefrontal cortex was particularly vulnerable to MDMA-induced alterations in that BDNF, NT-3, trkB, and trkC mRNAs were all upregulated at multiple time points. MDMA-treated animals had increased BDNF expression in the frontal, parietal, piriform, and entorhinal cortices, increased NT-3 expression in the anterior cingulate cortex, and elevated trkC in the entorhinal cortex. In the nigrostriatal system, BDNF expression was upregulated in the substantia nigra pars compacta, and trkB was elevated in the striatum in MDMA-treated animals. Both neurotrophins and trkB were differentially regulated in several regions of the hippocampal formation. These findings suggest a possible role for neurotrophin signaling in the learning and memory deficits seen following MDMA treatment. PMID:22237931

  17. TNF-TNFR2/p75 Signaling Inhibits Early and Increases Delayed Nontargeted Effects in Bone Marrow-derived Endothelial Progenitor Cells*

    PubMed Central

    Sasi, Sharath P.; Song, Jin; Park, Daniel; Enderling, Heiko; McDonald, J. Tyson; Gee, Hannah; Garrity, Brittany; Shtifman, Alexander; Yan, Xinhua; Walsh, Kenneth; Natarajan, Mohan; Kishore, Raj; Goukassian, David A.

    2014-01-01

    TNF-α, a pro-inflammatory cytokine, is highly expressed after being irradiated (IR) and is implicated in mediating radiobiological bystander responses (RBRs). Little is known about specific TNF receptors in regulating TNF-induced RBR in bone marrow-derived endothelial progenitor cells (BM-EPCs). Full body γ-IR WT BM-EPCs showed a biphasic response: slow decay of p-H2AX foci during the initial 24 h and increase between 24 h and 7 days post-IR, indicating a significant RBR in BM-EPCs in vivo. Individual TNF receptor (TNFR) signaling in RBR was evaluated in BM-EPCs from WT, TNFR1/p55KO, and TNFR2/p75KO mice, in vitro. Compared with WT, early RBR (1–5 h) were inhibited in p55KO and p75KO EPCs, whereas delayed RBR (3–5 days) were amplified in p55KO EPCs, suggesting a possible role for TNFR2/p75 signaling in delayed RBR. Neutralizing TNF in γ-IR conditioned media (CM) of WT and p55KO BM-EPCs largely abolished RBR in both cell types. ELISA protein profiling of WT and p55KO EPC γ-IR-CM over 5 days showed significant increases in several pro-inflammatory cytokines, including TNF-α, IL-1α (Interleukin-1 alpha), RANTES (regulated on activation, normal T cell expressed and secreted), and MCP-1. In vitro treatments with murine recombinant (rm) TNF-α and rmIL-1α, but not rmMCP-1 or rmRANTES, increased the formation of p-H2AX foci in nonirradiated p55KO EPCs. We conclude that TNF-TNFR2 signaling may induce RBR in naïve BM-EPCs and that blocking TNF-TNFR2 signaling may prevent delayed RBR in BM-EPCs, conceivably, in bone marrow milieu in general. PMID:24711449

  18. Effect of actual long-term spaceflight on BDNF, TrkB, p75, BAX and BCL-XL genes expression in mouse brain regions.

    PubMed

    Naumenko, V S; Kulikov, A V; Kondaurova, E M; Tsybko, A S; Kulikova, E A; Krasnov, I B; Shenkman, B S; Sychev, V N; Bazhenova, E Y; Sinyakova, N A; Popova, N K

    2015-01-22

    Mice of C57BL/6J strain were exposed to 1-month spaceflight on Russian biosatellite Bion-M1 to determine the effect of long-term actual spaceflight on the expression of genes involved in the processes of neurogenesis and apoptosis. Specifically, we focused on the genes encoding proapoptotic factor BAX, antiapoptotic factor BCL-XL, brain-derived neurotrophic factor (BDNF) and BDNF receptors TrkB and p75. Spaceflight reduced the expression of the antiapoptotic BCL-XL gene in the striatum and hypothalamus, but increased it in the hippocampus. To estimate environmental stress contribution into spaceflight effects we analyzed spaceflight-responsive genes in mice housed for 1 month on Earth in the same shuttle cabins that were used for spaceflight, and in mice of the laboratory control group. It was shown that 1-month shuttle cabin housing decreased BCL-XL gene expression in the striatum but failed to alter BCL-XL mRNA levels in the hippocampus or hypothalamus. Spaceflight failed to alter the expression of the proapoptotic BAX gene in all investigated brain structures, although the insignificant increase of the BAX mRNA level in the hippocampus of spaceflight mice was found. At the same time, shuttle cabin housing produced insignificant decrease in BAX gene expression in the hippocampus. In contrast to the BCL-XL gene, genes encoding BAX, BDNF as well as TrkB and p75 receptors did not respond to 30-day spaceflight. Thus, long-term spaceflight (1) did not affect the expression of genes encoding BDNF as well as TrkB and p75 receptors, (2) produced dysregulation in genetic control of the neuronal apoptosis, (3) implicated BCL-XL as the risk factor for spaceflight-induced behavioral abnormalities. PMID:25451288

  19. Coexpression of SOX10/CD271 (p75NTR) and β-Galactosidase in Large to Giant Congenital Melanocytic Nevi of Pediatric Patients

    PubMed Central

    Barysch, Marjam J.; Levesque, Mitchell P.; Cheng, Phil; Karpova, Maria B.; Mihic-Probst, Daniela; Civenni, Gianluca; Shakhova, Olga; Sommer, Lukas; Biedermann, Thomas; Schiestl, Clemens; Dummer, Reinhard

    2014-01-01

    Background Congenital melanocytic nevi (CMNs) are melanocytic neoplasms that can transform into melanoma. However, this development is impeded in the majority of cases and mostly affects patients with large or giant CMNs. Methods To elucidate mechanisms that keep CMNs from malignant transformation, CMN tissue biopsies were investigated for p-ERK and senescence markers by immunohistochemistry and for SOX10/CD271 (p75NTR) by immunofluorescence. CMN cells were cultivated, and MTT assays were performed for evaluating cell viability. Mutation status for NRAS and BRAF was performed by real-time PCR. Results 13 CMNs (from patients aged 0.5-11.8 years, mean: 2.7) showed immunoreactivity for SOX10/CD271 (p75NTR) in 34.2%. p-ERK was immunoreactive in 80% (4/5); β-galactosidase was significantly stronger expressed in CMNs compared to melanocytic nevi of patients over 70 years (p = 0.0085). The 5 CMN cultures were immunoreactive for SOX10/CD271 (p75NTR) in 36.7%. By silencing SOX10 by siRNA in 2 CMN cell cultures, cell viability decreased significantly. NRASQ61K mutation was found in 91.7% (11/12) and BRAFV600E in 6.3% of all analyzable CMNs (1/16). Conclusions Oncogene-induced senescence might prevent malignant transformation through activation of the mitogen-activated protein kinase pathway. SOX10 is necessary for the viability of human CMN cell cultures and may be responsible for clinical changes during aging. PMID:27047921

  20. Fingolimod (FTY720) enhances hippocampal synaptic plasticity and memory in Huntington's disease by preventing p75NTR up-regulation and astrocyte-mediated inflammation.

    PubMed

    Miguez, Andrés; García-Díaz Barriga, Gerardo; Brito, Verónica; Straccia, Marco; Giralt, Albert; Ginés, Silvia; Canals, Josep M; Alberch, Jordi

    2015-09-01

    Huntington's disease (HD) is a hereditary neurodegenerative disorder characterized by motor and cognitive impairments, involving striatum, cortex and hippocampus. Synaptic and memory dysfunction in HD mouse models have been related to low levels of brain-derived neurotrophic factor (BDNF) and imbalance between TrkB and p75(NTR) receptors. In addition, astrocyte over-activation has also been suggested to contribute to HD cognitive deficits. Fingolimod (FTY720), a modulator of sphingosine-1 phosphate (S1P) receptors, has been shown to increase BDNF levels and to reduce astrogliosis, proving its potential to regulate trophic support and inflammatory response. In this view, we have investigated whether FTY720 improves synaptic plasticity and memory in the R6/1 mouse model of HD, through regulation of BDNF signaling and astroglial reactivity. Chronic administration of FTY720 from pre-symptomatic stages ameliorated long-term memory deficits and dendritic spine loss in CA1 hippocampal neurons from R6/1 mice. Furthermore, FTY720 delivery prevented astrogliosis and over-activation of nuclear factor kappa beta (NF-κB) signaling in the R6/1 hippocampus, reducing tumor necrosis factor alpha (TNFα) and induced nitric oxide synthase (iNOS) levels. TNFα decrease correlated with the normalization of p75(NTR) expression in the hippocampus of FTY720-treated R6/1 mice, thus preventing p75(NTR)/TrkB imbalance. In addition, FTY720 increased cAMP levels and promoted phosphorylation of CREB and RhoA in the hippocampus of R6/1 mice, further supporting its role in the enhancement of synaptic plasticity. Our findings provide new insights into the mechanism of action of FTY720 and reveal a novel therapeutic strategy to treat memory deficits in HD. PMID:26063761

  1. Enhanced CREB phosphorylation in immature dentate gyrus granule cells precedes neurotrophin expression and indicates a specific role of CREB in granule cell differentiation

    PubMed Central

    Bender, R. A.; Lauterborn, J. C.; Gall, C. M.; Cariaga, W.; Baram, T. Z.

    2011-01-01

    Differentiation and maturation of dentate gyrus granule cells requires coordinated interactions of numerous processes. These must be regulated by protein factors capable of integrating signals mediated through diverse signalling pathways. Such integrators of inter and intracellular physiological stimuli include the cAMP-response element binding protein (CREB), a leucine-zipper class transcription factor that is activated through phosphorylation. Neuronal activity and neurotrophic factors, known to be involved in granule cell differentiation, are major physiologic regulators of CREB function. To examine whether CREB may play a role in governing coordinated gene transcription during granule cell differentiation, we determined the spatial and temporal profiles of phosphorylated (activated) CREB throughout postnatal development in immature rat hippocampus. We demonstrate that CREB activation is confined to discrete, early stages of granule cell differentiation. In addition, CREB phosphorylation occurs prior to expression of the neurotrophins BDNF and NT-3. These data indicate that in a signal transduction cascade connecting CREB and neurotrophins in the process of granule cell maturation, CREB is located upstream of neurotrophins. Importantly, CREB may be a critical component of the machinery regulating the coordinated transcription of genes contributing to the differentiation of granule cells and their integration into the dentate gyrus network. PMID:11207803

  2. Comparative binding of biotinylated neurotrophins to alpha(2)-macroglobulin family of proteins: relationship between cytokine-binding and neuro-modulatory activities of the macroglobulins.

    PubMed

    Skornicka, Erin L; Shi, Xiaoqing; Koo, Peter H

    2002-02-01

    Human alpha(2)-macroglobulin (alpha(2)M), pregnancy zone protein (PZP), rat alpha(1)M and acute-phase rat alpha(2)M belong to the alpha(2)M gene family of proteins, which can react covalently with nucleophilic monoamines to yield monoamine-activated (MA) macroglobulins. The MA forms of human alpha(2)M, PZP and rat alpha(2)M have been demonstrated previously to inhibit various neurotrophin-promoted neuronal activities, whereas MA-alpha(1)M is neurostimulatory and all native macroglobulins are generally inactive. The mechanism of neuromodulation is unknown, but it has been postulated that MA macroglobulins might inhibit neurons via their binding and sequestration of neurotrophins. This study employed a novel biotinylation-Western blot technique to compare the neurotrophin-binding properties of the four macroglobulins, and to correlate their binding activities with their known neuro-modulatory activities. In comparison with their respective native counterparts, human and rat MA-alpha(2)M bound slightly more NGF, but significantly less BDNF or NT-3. Native human alpha(2)M and PZP in general have no neuro-modulatory activity, but native PZP bound significantly more NGF, BDNF or NT-3 than either native alpha(2)M or MA-alpha(2)M, which is neuro-inhibitory. It is known that MA-PZP is neuro-inhibitory, but it fails to bind more NGF, BDNF, or NT-3 than native PZP. MA-alpha(1)M is the only macroglobulin known to stimulate NGF-promoted neurite outgrowth, but it bound NGF with similar affinities as native alpha(1)M and rat alpha(2)M; in addition, it bound significantly less BDNF or NT-3 than native alpha(1)M. All the bindings were non-covalent and appeared specific. In conclusion, PZP and rat macroglobulins are versatile carriers of neurotrophins with diverse binding capacities, and the neurotrophin-binding property does not appear to mediate the neuro-modulatory activity of these human and rat macroglobulins. PMID:11813239

  3. p75NTR-dependent activation of NF-κB regulates microRNA-503 transcription and pericyte–endothelial crosstalk in diabetes after limb ischaemia

    PubMed Central

    Caporali, Andrea; Meloni, Marco; Nailor, Audrey; Mitić, Tijana; Shantikumar, Saran; Riu, Federica; Sala-Newby, Graciela B.; Rose, Lorraine; Besnier, Marie; Katare, Rajesh; Voellenkle, Christine; Verkade, Paul; Martelli, Fabio; Madeddu, Paolo; Emanueli, Costanza

    2015-01-01

    The communication between vascular endothelial cells (ECs) and pericytes in the microvasculature is fundamental for vascular growth and homeostasis; however, these processes are disrupted by diabetes. Here we show that modulation of p75NTR expression in ECs exposed to high glucose activates transcription of miR-503, which negatively affects pericyte function. p75NTR activates NF-κB to bind the miR-503 promoter and upregulate miR-503 expression in ECs. NF-κB further induces activation of Rho kinase and shedding of endothelial microparticles carrying miR-503, which transfer miR-503 from ECs to vascular pericytes. The integrin-mediated uptake of miR-503 in the recipient pericytes reduces expression of EFNB2 and VEGFA, resulting in impaired migration and proliferation. We confirm operation of the above mechanisms in mouse models of diabetes, in which EC-derived miR-503 reduces pericyte coverage of capillaries, increased permeability and impaired post-ischaemic angiogenesis in limb muscles. Collectively, our data demonstrate that miR-503 regulates pericyte–endothelial crosstalk in microvascular diabetic complications. PMID:26268439

  4. Effects of exogenous neurotrophin-3 on myocyte apoptosis and Ca2+-ATP enzyme levels following nerve injury in rats

    PubMed Central

    Dong, Yu-Zhen; Yang, Lin; Lu, Tan; Zhao, Hong-Xing; Ma, Chao; Zhao, Yi-Lei

    2015-01-01

    This study aims to determine the influence of neurotrophin-3 (NT-3) plasmids on neuronal apoptosis and Ca2+-ATP enzyme levels in injured muscles. We also investigated the mechanism underlying the role of NT-3 in delaying muscle atrophy following a peripheral nerve injury. Sixty adult Wistar rats were used to generate the peripheral nerve injury models. The rats were randomly assigned to the saline and NT-3 groups. Related indicators, such as caspase-3 protein expression, skeletal muscle cell apoptosis, and Ca2+-ATP enzyme expression were quantified. The expression levels of caspase-3 and the histone-muscle cell apoptosis rate in the NT-3 group decreased at different post-operative times following peripheral nerve injury, whereas NT-3 expression and the sarcoplasmic reticulum Ca2+-ATP enzyme levels increased. Statistically significant differences were observed in the NT-3 group as compared to the saline group (P < 0.05). NT-3 mitigated muscle atrophy following peripheral nerve damage by inhibiting caspase-3 gene expression and increasing Ca2+-ATP enzymatic activity, ultimately reducing muscle apoptosis. PMID:26770627

  5. Neurotrophin-3 Is Involved in the Formation of Apical Dendritic Bundles in Cortical Layer 2 of the Rat

    PubMed Central

    Wintzer, Marie; Kurotani, Tohru; Konishi, Tomokazu; Ichinohe, Noritaka; Rockland, Kathleen S.

    2010-01-01

    Apical dendritic bundles from pyramidal neurons are a prominent feature of cortical neuropil but with significant area specializations. Here, we investigate mechanisms of bundle formation, focusing on layer (L) 2 bundles in rat granular retrosplenial cortex (GRS), a limbic area implicated in spatial memory. By using microarrays, we first searched for genes highly and specifically expressed in GRS L2 at postnatal day (P) 3 versus GRS L2 at P12 (respectively, before and after bundle formation), versus GRS L5 (at P3), and versus L2 in barrel field cortex (BF) (at P3). Several genes, including neurotrophin-3 (NT-3), were identified as transiently and specifically expressed in GRS L2. Three of these were cloned and confirmed by in situ hybridization. To test that NT-3–mediated events are causally involved in bundle formation, we used in utero electroporation to overexpress NT-3 in other cortical areas. This produced prominent bundles of dendrites originating from L2 neurons in BF, where L2 bundles are normally absent. Intracellular biocytin fills, after physiological recording in vitro, revealed increased dendritic branching in L1 of BF. The controlled ectopic induction of dendritic bundles identifies a new role for NT-3 and a new in vivo model for investigating dendritic bundles and their formation. PMID:19447860

  6. Effects of acute and chronic treatment elicited by lamotrigine on behavior, energy metabolism, neurotrophins and signaling cascades in rats.

    PubMed

    Abelaira, Helena M; Réus, Gislaine Z; Ribeiro, Karine F; Zappellini, Giovanni; Ferreira, Gabriela K; Gomes, Lara M; Carvalho-Silva, Milena; Luciano, Thais F; Marques, Scherolin O; Streck, Emilio L; Souza, Cláudio T; Quevedo, João

    2011-12-01

    The present study was aimed to investigate the behavioral and molecular effects of lamotrigine. To this aim, Wistar rats were treated with lamotrigine (10 and 20 mg/kg) or imipramine (30 mg/kg) acutely and chronically. The behavior was assessed using forced swimming test. Brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), Proteina Kinase B (PKB, AKT), glycogen synthase kinase 3 (GSK-3) and B-cell lymphoma 2 (Bcl-2) levels, citrate synthase, creatine kinase and mitochondrial chain (I, II, II-III and IV) activities were assessed in the brain. The results showed that both treatments reduced the immobility time. The BDNF were increased in the prefrontal after acute treatment with lamotrigine (20 mg/kg), and the BDNF and NGF were increased in the prefrontal after chronic treatment with lamotrigine in all doses. The AKT increased and Bcl-2 and GSK-3 decreased after both treatments in all brain areas. The citrate synthase and creatine kinase increased in the amygdala after acute treatment with imipramine. Chronic treatment with imipramine and lamotrigine (10 mg/kg) increased the creatine kinase in the hippocampus. The complex I was reduced and the complex II, II-III and IV were increased, but related with treatment and brain area. In conclusion, lamotrigine exerted antidepressant-like, which can be attributed to its effects on pathways related to depression, such as neurotrophins, metabolism energy and signaling cascade. PMID:22044672

  7. Spontaneous Wheel Running Exercise Induces Brain Recovery via Neurotrophin-3 Expression Following Experimental Traumatic Brain Injury in Rats.

    PubMed

    Koo, Hyun Mo; Lee, Sun Min; Kim, Min Hee

    2013-09-01

    [Purpose] The aim of the present study was to investigate the expression of neurotrophin-3 (NT-3) after applying spontaneous wheel running exercises (SWR) after experimental traumatic brain injury (TBI). [Subjects and Methods] Thirty male Sprague-Dawley rats were divided into 3 groups; 20 rats were subjected to controlled cortical impact for TBI, and then, animals were randomly collected from the SWR group and subjected to wheel running exercise for 3 weeks. Ten rats were not subjected to any injury or running exercise to compare with the effect of TBI and SWR. Immunohistochemistry, Western blotting, skilled ladder rung walking test, and 2,3,5-triphenyltetrazolium chloride staining analysis for the evaluation of NT-3 expression were used to assess brain damage and recovery. [Results] The TBI-induced decrease in NT-3 expression was recovered by wheel running exercise. Moreover, decreased ischemic volume and progressive neurobehavioral outcome were observed in the SWR group. [Conclusion] Spontaneous running exercise promotes brain recovery and motor function through an increase in expression of NT-3. PMID:24259924

  8. The trkB Tyrosine Protein Kinase Is a Receptor for Brain-Derived Neurotrophic Factor and Neurotrophin-3

    PubMed Central

    Klein, Rüdiger; Nanduri, Venkata; Jing, Shuqian; Lamballe, Fabienne; Tapley, Peter; Bryant, Sherri; Cordon-Cardo, Carlos; Jones, Kevin R.; Reichardt, Louis F.; Barbacid, Mariano

    2009-01-01

    Summary trkB is a tyrosine protein kinase gene highly related to trk, a proto-oncogene that encodes a receptor for nerve growth factor (NGF) and neurotrophin-3 (NT-3). trkB expression is confined to structures of the central and peripheral nervous systems, suggesting it also encodes a receptor for neurotrophic factors. Here we show that brain-derived neurotrophic factor (BDNF) and NT-3, but not NGF, can induce rapid phosphorylation on tyrosine of gp145trkB, one of the receptors encoded by trkB. BDNF and NT-3 can induce DNA synthesis in quiescent NIH 3T3 cells that express gp145trkB. Cotransfection of plasmids encoding gp145trkB and BDNF or NT-3 leads to transformation of recipient NIH 3T3 cells. In these assays, BDNF elicits a response at least two orders of magnitude higher than NT-3. Finally, 125I-NT-3 binds to NIH 3T3 cells expressing gp145trkB; binding can be competed by NT-3 and BDNF but not by NGF. These findings indicate that gp145trkB may function as a neurotrophic receptor for BDNF and NT-3. PMID:1649702

  9. Effects of Electroacupuncture at Governor Vessel Acupoints on Neurotrophin-3 in Rats with Experimental Spinal Cord Injury

    PubMed Central

    Lv, Wei; Song, Liang-yu; Song, Hong-tao; Yuan, Xiao-chen; Mao, Ying-qiu; Jing, Quan-kai

    2016-01-01

    In an effort to explore new, noninvasive treatment options for spinal cord injuries (SCI), this study investigated the effects of electroacupuncture (EA) for SCI rat models. SCI was induced by a modified Allen's weight-drop method. We investigated the response of EA at Dazhui (GV 14) and Mingmen (GV 4) acupoints to understand the effects and mechanisms of EA in neuroprotection and neuronal function recovery after SCI. BBB testing was used to detect motor function of rats' hind limbs among groups, and EA was shown to promote the recovery of SCI rats' motor function. Nissl staining showed a restored neural morphology and an increase in the quantity of neurons after EA. Also, the antiapoptosis role was exposed by TUNEL staining. Western blotting analysis was used to determine the protein expression of neurotrophin-3 (NT-3) in spinal cord tissue. Compared to the sham group, the expression levels of NT-3 were significantly decreased and EA was shown to upregulate the expression of NT-3. The present study suggests that the role of EA in neuroprotection and dorsal neuronal function recovery after SCI in rats, especially EA stimulation at GV 14 and GV 4, can greatly promote neuronal function recovery, which may result from upregulating the expression of NT-3. PMID:27597902

  10. Nucleotide sequence variation within the human tyrosine kinase B neurotrophin receptor gene: association with antisocial alcohol dependence.

    PubMed

    Xu, K; Anderson, T R; Neyer, K M; Lamparella, N; Jenkins, G; Zhou, Z; Yuan, Q; Virkkunen, M; Lipsky, R H

    2007-12-01

    To identify sequence variants in genes that may have roles in neuronal responses to alcohol, we resequenced the 5' region of tyrosine kinase B neurotrophin receptor gene (NTRK2) and determined linkage disequilibrium (LD) values, haplotype structure, and performed association analyses using 43 single nucleotide polymorphisms (SNPs) covering the entire NTRK2 region in a Finnish Caucasian sample of 229 alcohol-dependent subjects with antisocial personality disorder (ASPD) and 287 healthy controls. Individually, three SNPs were associated with alcohol dependence and alcohol abuse (AD) (P-value from 0.0019 to 0.0059, significance level was set at P

  11. Neuromuscular interaction is required for neurotrophins-mediated locomotor recovery following treadmill training in rat spinal cord injury

    PubMed Central

    Wu, Qinfeng; Cao, Yana; Dong, Chuanming; Wang, Hongxing; Wang, Qinghua; Tong, Weifeng; Li, Xiangzhe

    2016-01-01

    Recent results have shown that exercise training promotes the recovery of injured rat distal spinal cords, but are still unclear about the function of skeletal muscle in this process. Herein, rats with incomplete thoracic (T10) spinal cord injuries (SCI) with a dual spinal lesion model were subjected to four weeks of treadmill training and then were treated with complete spinal transection at T8. We found that treadmill training allowed the retention of hind limb motor function after incomplete SCI, even with a heavy load after complete spinal transection. Moreover, treadmill training alleviated the secondary injury in distal lumbar spinal motor neurons, and enhanced BDNF/TrkB expression in the lumbar spinal cord. To discover the influence of skeletal muscle contractile activity on motor function and gene expression, we adopted botulinum toxin A (BTX-A) to block the neuromuscular activity of the rat gastrocnemius muscle. BTX-A treatment inhibited the effects of treadmill training on motor function and BDNF/TrKB expression. These results indicated that treadmill training through the skeletal muscle-motor nerve-spinal cord retrograde pathway regulated neuralplasticity in the mammalian central nervous system, which induced the expression of related neurotrophins and promoted motor function recovery. PMID:27190721

  12. Role of the conformational versatility of the neurotrophin N-terminal regions in their recognition by Trk receptors.

    PubMed

    Stanzione, Francesca; Esposito, Luciana; Paladino, Antonella; Pedone, Carlo; Morelli, Giancarlo; Vitagliano, Luigi

    2010-10-01

    Neurotrophins (NTs) represent a family of proteins that play an important role in the survival, development, and function of neurons. Extensive efforts are currently being made to develop small molecules endowed with agonist or antagonist NT activity. The structurally versatile N-termini of these proteins are considered regions of interest for the design of new molecules. By combining experimental and computational approaches, we analyzed the intrinsic conformational preferences of the N-termini of two of the most important NTs: NGF (NGF-Nter) and NT4 (NT4-Nter). Circular dichroism spectra clearly indicate that both peptides show a preference for random coil states. Because this finding does not preclude the possibility that structured forms may occur in solution as minor conformational states, we performed molecular-dynamics simulations to gain insights into the structural features of populated species. In line with the circular dichroism analysis, the simulations show a preference for unstructured states for both peptides. However, the simulations also show that for NT4-Nter, and to a lesser extent for NGF-Nter, helical conformations, which are required for binding to the Trk receptor, are present in the repertoire of structures that are intrinsically accessible to these peptides. Accordingly, molecular recognition of NTs by the Trk receptor is accomplished by the general mechanism known as population shift. These findings provide a structural rationale for the observed activity of synthetic peptides based on these NT regions. They also suggest strategies for the development of biologically active peptide-based compounds. PMID:20923662

  13. Effects of Electroacupuncture at Governor Vessel Acupoints on Neurotrophin-3 in Rats with Experimental Spinal Cord Injury.

    PubMed

    Mo, Yu-Ping; Yao, Hai-Jiang; Lv, Wei; Song, Liang-Yu; Song, Hong-Tao; Yuan, Xiao-Chen; Mao, Ying-Qiu; Jing, Quan-Kai; Shi, Su-Hua; Li, Zhi-Gang

    2016-01-01

    In an effort to explore new, noninvasive treatment options for spinal cord injuries (SCI), this study investigated the effects of electroacupuncture (EA) for SCI rat models. SCI was induced by a modified Allen's weight-drop method. We investigated the response of EA at Dazhui (GV 14) and Mingmen (GV 4) acupoints to understand the effects and mechanisms of EA in neuroprotection and neuronal function recovery after SCI. BBB testing was used to detect motor function of rats' hind limbs among groups, and EA was shown to promote the recovery of SCI rats' motor function. Nissl staining showed a restored neural morphology and an increase in the quantity of neurons after EA. Also, the antiapoptosis role was exposed by TUNEL staining. Western blotting analysis was used to determine the protein expression of neurotrophin-3 (NT-3) in spinal cord tissue. Compared to the sham group, the expression levels of NT-3 were significantly decreased and EA was shown to upregulate the expression of NT-3. The present study suggests that the role of EA in neuroprotection and dorsal neuronal function recovery after SCI in rats, especially EA stimulation at GV 14 and GV 4, can greatly promote neuronal function recovery, which may result from upregulating the expression of NT-3. PMID:27597902

  14. Neuromuscular interaction is required for neurotrophins-mediated locomotor recovery following treadmill training in rat spinal cord injury.

    PubMed

    Wu, Qinfeng; Cao, Yana; Dong, Chuanming; Wang, Hongxing; Wang, Qinghua; Tong, Weifeng; Li, Xiangzhe; Shan, Chunlei; Wang, Tong

    2016-01-01

    Recent results have shown that exercise training promotes the recovery of injured rat distal spinal cords, but are still unclear about the function of skeletal muscle in this process. Herein, rats with incomplete thoracic (T10) spinal cord injuries (SCI) with a dual spinal lesion model were subjected to four weeks of treadmill training and then were treated with complete spinal transection at T8. We found that treadmill training allowed the retention of hind limb motor function after incomplete SCI, even with a heavy load after complete spinal transection. Moreover, treadmill training alleviated the secondary injury in distal lumbar spinal motor neurons, and enhanced BDNF/TrkB expression in the lumbar spinal cord. To discover the influence of skeletal muscle contractile activity on motor function and gene expression, we adopted botulinum toxin A (BTX-A) to block the neuromuscular activity of the rat gastrocnemius muscle. BTX-A treatment inhibited the effects of treadmill training on motor function and BDNF/TrKB expression. These results indicated that treadmill training through the skeletal muscle-motor nerve-spinal cord retrograde pathway regulated neuralplasticity in the mammalian central nervous system, which induced the expression of related neurotrophins and promoted motor function recovery. PMID:27190721

  15. Diabetic Schwann cells suffer from nerve growth factor and neurotrophin-3 underproduction and poor associability with axons.

    PubMed

    Dey, Indranil; Midha, Nisha; Singh, Geeta; Forsyth, Amanda; Walsh, Sarah K; Singh, Bhagat; Kumar, Ranjan; Toth, Cory; Midha, Rajiv

    2013-12-01

    Schwann cells (SCs) are integral to peripheral nerve biology, contributing to saltatory conduction along axons, nerve and axon development, and axonal regeneration. SCs also provide a microenvironment favoring neural regeneration partially due to production of several neurotrophic factors. Dysfunction of SCs may also play an important role in the pathogenesis of peripheral nerve diseases such as diabetic peripheral neuropathy where hyperglycemia is often considered pathogenic. In order to study the impact of diabetes mellitus (DM) upon the regenerative capacity of adult SCs, we investigated the differential production of the neurotrophic factors nerve growth factor (NGF) and neurotrophin-3 (NT3) by SCs harvested from the sciatic nerves of murine models of type 1 DM (streptozotocin treated C57BL/6J mice) and type 2 DM (LepR(-/-) or db/db mice) or non-diabetic cohorts. In vitro, SCs from diabetic and control mice were maintained under similar hyperglycemic and euglycemic conditions respectively. Mature SCs from diabetic mice produced lower levels of NGF and NT3 under hyperglycemic conditions when compared to SCs in euglycemia. In addition, SCs from both DM and non-DM mice appear to be incapable of insulin production, but responded to exogenous insulin with greater proliferation and heightened myelination potentiation. Moreover, SCs from diabetic animals showed poorer association with co-cultured axons. Hyperglycemia had significant impact upon SCs, potentially contributing to the pathogenesis of diabetic peripheral neuropathy. PMID:24123456

  16. The Competitive Interplay between Allosteric HIV-1 Integrase Inhibitor BI/D and LEDGF/p75 during the Early Stage of HIV-1 Replication Adversely Affects Inhibitor Potency.

    PubMed

    Feng, Lei; Dharmarajan, Venkatasubramanian; Serrao, Erik; Hoyte, Ashley; Larue, Ross C; Slaughter, Alison; Sharma, Amit; Plumb, Matthew R; Kessl, Jacques J; Fuchs, James R; Bushman, Frederic D; Engelman, Alan N; Griffin, Patrick R; Kvaratskhelia, Mamuka

    2016-05-20

    Allosteric HIV-1 integrase inhibitors (ALLINIs) have recently emerged as a promising class of antiretroviral agents and are currently in clinical trials. In infected cells, ALLINIs potently inhibit viral replication by impairing virus particle maturation but surprisingly exhibit a reduced EC50 for inhibiting HIV-1 integration in target cells. To better understand the reduced antiviral activity of ALLINIs during the early stage of HIV-1 replication, we investigated the competitive interplay between a potent representative ALLINI, BI/D, and LEDGF/p75 with HIV-1 integrase. While the principal binding sites of BI/D and LEDGF/p75 overlap at the integrase catalytic core domain dimer interface, we show that the inhibitor and the cellular cofactor induce markedly different multimerization patterns of full-length integrase. LEDGF/p75 stabilizes an integrase tetramer through the additional interactions with the integrase N-terminal domain, whereas BI/D induces protein-protein interactions in C-terminal segments that lead to aberrant, higher-order integrase multimerization. We demonstrate that LEDGF/p75 binds HIV-1 integrase with significantly higher affinity than BI/D and that the cellular protein is able to reverse the inhibitor induced aberrant, higher-order integrase multimerization in a dose-dependent manner in vitro. Consistent with these observations, alterations of the cellular levels of LEDGF/p75 markedly affected BI/D EC50 values during the early steps of HIV-1 replication. Furthermore, genome-wide sequencing of HIV-1 integration sites in infected cells demonstrate that LEDGF/p75-dependent integration site selection is adversely affected by BI/D treatment. Taken together, our studies elucidate structural and mechanistic details of the interplay between LEDGF/p75 and BI/D during the early stage of HIV-1 replication. PMID:26910179

  17. Association of Single Nucleotide Polymorphisms in the Lens Epithelium-Derived Growth Factor (LEDGF/p75) with HIV-1 Infection Outcomes in Brazilian HIV-1+ Individuals

    PubMed Central

    Caetano, Diogo Gama; Teixeira, Sylvia Lopes Maia; Guimarães, Monick Lindenmeyer; Campos, Dayse Pereira; Veloso, Valdilea Gonçalves; Babic, Dunja Z.; Stevenson, Mario; Moraes, Milton Ozório; Morgado, Mariza Gonçalves

    2014-01-01

    The lens epithelium-derived growth factor p75 (LEDGF/p75), coded by the PSIP1 gene, is an important host co-factor that interacts with HIV-1 integrase to target integration of viral cDNA into active genes. The aim of this study was to investigate the association of SNPs in the PSIP1 gene with disease outcome in HIV-1 infected patients. We performed a genetic association study in a cohort of 171 HIV-1 seropositive Brazilian individuals classified as rapid progressors (RP, n = 69), typical progressors (TP, n = 79) and long-term nonprogressors (LTNP, n = 23). The exonic SNP rs61744944 and 9 tag SNPs were genotyped. A group of 192 healthy subjects was analyzed to determine the frequency of SNPs and haplotypes in the general population. Linkage disequilibrium (LD) analyses indicated that the SNPs analyzed were not in high LD (r2<0.8). Logistic regression models suggested that patients carrying the T allele rs61744944 (472L) were more likely to develop a LTNP phenotype (OR = 4.98; p = 0.05) as compared to TP group. The same trend was observed when LTNPs were compared to the RP group (OR = 3.26). Results of haplotype analyses reinforced this association, since the OR values obtained for the haplotype carrying allele T at rs61744944 also reflected an association with LTNP status (OR = 6.05; p = 0.08 and OR = 3.44; p = 0.12 for comparisons to TP and RP, respectively). The rare missense variations Ile436Ser and Thr473Ile were not identified in the patients enrolled in this study. Gene expression analyses showed lower LEDGF/p75 mRNA levels in peripheral blood mononuclear cells obtained from HIV-1 infected individuals. However, these levels were not influenced by any of the SNPs investigated. In spite of the limited number of LTNPs, these data suggest that the PSIP1 gene could be associated with the outcome of HIV-1 infection. Further analyses of this gene may guide the identification of causative variants to help predict disease course

  18. Furospinosulin-1, Marine Spongean Furanosesterterpene, Suppresses the Growth of Hypoxia-Adapted Cancer Cells by Binding to Transcriptional Regulators p54(nrb) and LEDGF/p75.

    PubMed

    Arai, Masayoshi; Kawachi, Takashi; Kotoku, Naoyuki; Nakata, Chiaki; Kamada, Haruhiko; Tsunoda, Shin-ichi; Tsutsumi, Yasuo; Endo, Hiroko; Inoue, Masahiro; Sato, Hiroki; Kobayashi, Motomasa

    2016-01-01

    Hypoxia-adapted cancer cells in tumors contribute to the pathological progression of cancer. Cancer research has therefore focused on the identification of molecules responsible for hypoxia adaptation in cancer cells, as well as the development of new compounds with action against hypoxia-adapted cancer cells. The marine natural product furospinosulin-1 (1) has displayed hypoxia-selective growth inhibition against cultured cancer cells, and has shown in vivo anti-tumor activity, although its precise mode of action and molecular targets remain unclear. In this study, we found that 1 is selectively effective against hypoxic regions of tumors, and that it directly binds to the transcriptional regulators p54(nrb) and LEDGF/p75, which have not been previously identified as mediators of hypoxia adaptation in cancer cells. PMID:26561285

  19. Differential stimulation of neurotrophin release by the biocompatible nano-material (carbon nanotube) in primary cultured neurons.

    PubMed

    Kim, Yun Gi; Kim, Jong Wan; Pyeon, Hee Jang; Hyun, Jung Keun; Hwang, Ji-Young; Choi, Seong-Jun; Lee, Ja-Yeon; Deák, Ferenc; Kim, Hae-Won; Lee, Young Il

    2014-01-01

    In order to develop novel, effective therapies for central nervous system regeneration, it is essential to better understand the role of neurotrophic factors and to design, accordingly, better artificial scaffolds to support both neurite outgrowth and synapse formation. Both nerve growth factor and brain-derived neurotrophic factor are major factors in neural survival, development, synaptogenesis, and synaptic connectivity of primary cultured neurons. As a prime candidate coating material for such neural cultures, carbon nanotubes offer unique structural, mechanical, and electrical properties. In this study, carbon nanotubes coated glass-coverslips were used as the matrix of a primary neural culture system used to investigate the effects of carbon nanotubes on neurite outgrowth and nerve growth factor/brain-derived neurotrophic factor release and expression. For these purposes, we performed comparative analyses of primary cultured neurons on carbon nanotubes coated, non-coated, and Matrigel-coated coverslips. The morphological findings showed definite carbon nanotubes effects on the neurite outgrowths and synaptogenic figures in both cortical and hippocampal neurons when compared with the non-coated negative control. Although the carbon nanotubes did not change neurotrophin expression levels, it stimulated brain-derived neurotrophic factor release into the media from both types of neurons. Accordingly, we suggest a different mechanism of action between carbon nanotubes and Matrigel in relation to the specific neurotrophic factors. Since carbon nanotubes supply long-term extracellular molecular cues for the survival and neurite outgrowths of cultured neurons, the results from this study will contribute to an understanding of carbon nanotubes biological effects and provide new insight into their role in the secretion of neurotrophic factors. PMID:23559662

  20. Neurotrophins and cognitive functions in T1D compared with healthy controls: effects of a high-intensity exercise.

    PubMed

    Tonoli, Cajsa; Heyman, Elsa; Buyse, Luk; Roelands, Bart; Piacentini, Maria Francesca; Bailey, Stephen; Pattyn, Nathalie; Berthoin, Serge; Meeusen, Romain

    2015-01-01

    Exercise is known to have beneficial effects on cognitive function. This effect is greatly favored by an exercise-induced increase in neurotrophic factors, such as brain-derived neurotrophic factor (BDNF) and insulin-like growth factor-1 (IGF-1), especially with high-intensity exercises (HIE). As a complication of type 1 diabetes (T1D), a cognitive decline may occur, mostly ascribed to hypoglycaemia and chronic hyperglycaemia. Therefore, the purpose of this study was to examine the effects of acute HIE on cognitive function and neurotrophins in T1D and matched controls. Ten trained T1D (8 males, 2 females) participants and their matched (by age, sex, fitness level) controls were evaluated on 2 occasions after familiarization: a maximal test to exhaustion and an HIE bout (10 intervals of 60 s at 90% of their maximal wattage followed by 60 s at 50 W). Cognitive tests and analyses of serum BDNF, IGF-1, and free insulin were performed before and after HIE and following 30 min of recovery. At baseline, cognitive performance was better in the controls compared with the T1D participants (p < 0.05). After exercise, no significant differences in cognitive performance were detected. BDNF levels were significantly higher and IGF-1 levels were significantly lower in T1D compared with the control group (p < 0.05) at all time points. Exercise increased BDNF and IGF-1 levels in a comparable percentage in both groups (p < 0.05). In conclusion, although resting levels of serum BDNF and IGF-1 were altered by T1D, comparable increasing effects on BDNF and IGF-1 in T1D and healthy participants were found. Therefore, regularly repeating acute HIE could be a promising strategy for brain health in T1D. PMID:25525862

  1. Contrasting effects of basic fibroblast growth factor and neurotrophin 3 on cell cycle kinetics of mouse cortical stem cells

    PubMed Central

    Lukaszewicz, Agnès; Savatier, Pierre; Cortay, Véronique; Kennedy, Henry; Dehay, Colette

    2002-01-01

    Basic fibroblast growth factor (bFGF) exerts a mitogenic effect on cortical neuroblasts, whereas neurotrophin 3 (NT3) promotes differentiation in these cells. Here we provide evidence that both the mitogenic effect of bFGF and the differentiation-promoting effect of NT3 are linked with modifications of cell cycle kinetics in mouse cortical precursor cells. We adapted an in vitro assay, which makes it possible to evaluate (1) the speed of progression of the cortical precursors through the cell cycle, (2) the duration of individual phases of the cell cycle, (3) the proportion of proliferative versus differentiative divisions, and (4) the influence on neuroglial differentiation. Contrary to what has been claimed previously, bFGF promotes proliferation via a change in cell cycle kinetics by simultaneously decreasing G1 duration and increasing the proportion of proliferative divisions. In contrast, NT3 lengthens G1 and promotes differentiative divisions. We investigated the molecular foundations of these effects and show that bFGF downregulates p27kip1 and upregulates cyclin D2 expression. This contrasts with NT3, which upregulates p27kip1 and downregulates cyclin D2 expression. Neither bFGF nor NT3 influences the proportion of glia or neurons in short to medium term cultures. The data point to links between the length of the G1 phase and the type of division of cortical precursors: differentiative divisions are correlated with long G1 durations, whereas proliferative divisions correlate with short G1 durations. The present results suggest that concerted mechanisms control the progressive increase in the cell cycle duration and proportion of differentiative divisions that is observed as corticogenesis proceeds. PMID:12151540

  2. Polybutylcyanoacrylate nanoparticles for delivering hormone response element-conjugated neurotrophin-3 to the brain of intracerebral hemorrhagic rats.

    PubMed

    Chung, Chiu-Yen; Yang, Jen-Tsung; Kuo, Yung-Chih

    2013-12-01

    Hypertensive intracerebral hemorrhage (ICH) is a rapidly evolutional pathology, inducing necrotic cell death followed by apoptosis, and alters gene expression levels in surrounding tissue of an injured brain. For ICH therapy by controlled gene release, the development of intravenously administrable delivery vectors to promote the penetration across the blood-brain barrier (BBB) is a critical challenge. To enhance transfer efficiency of genetic materials under hypoxic conditions, polybutylcyanoacrylate (PBCA) nanoparticles (NPs) were used to mediate the intracellular transport of plasmid neurotrophin-3 (NT-3) containing hormone response element (HRE) with a cytomegalovirus (cmv) promoter and to differentiate induced pluripotent stem cells (iPSCs). The differentiation ability of iPSCs to neurons was justified by various immunological stains for protein fluorescence. The effect of PBCA NP/cmvNT-3-HRE complexes on treating ICH rats was studied by immunostaining, western blotting and Nissl staining. We found that the treatments with PBCA NP/cmvNT-3-HRE complexes increased the capability of differentiating iPSCs to express NT-3, TrkC and MAP-2. Moreover, PBCA NPs could protect cmvNT-3-HRE against degradation with EcoRI/PstI and DNase I in vitro and raise the delivery across the BBB in vivo. The administration of PBCA NP/cmvNT-3-HRE complexes increased the expression of NT-3, inhibited the expression of apoptosis-inducing factor, cleaved caspase-3 and DNA fragmentation, and reduced the cell death rate after ICH in vivo. PBCA NPs are demonstrated as an appropriate delivery system for carrying cmvNT-3-HRE to the brain for ICH therapy. PMID:24034503

  3. Sustained release of neurotrophin-3 via calcium phosphate-coated sutures promotes axonal regeneration after spinal cord injury.

    PubMed

    Hanna, Amgad; Thompson, Daniel L; Hellenbrand, Daniel J; Lee, Jae-Sung; Madura, Casey J; Wesley, Meredith G; Dillon, Natalie J; Sharma, Tapan; Enright, Connor J; Murphy, William L

    2016-07-01

    Because of the dynamics of spinal cord injury (SCI), the optimal treatment will almost certainly be a combination approach to control the environment and promote axonal growth. This study uses peripheral nerve grafts (PNGs) as scaffolds for axonal growth while delivering neurotrophin-3 (NT-3) via calcium phosphate (CaP) coatings on surgical sutures. CaP coating was grown on sutures, and NT-3 binding and release were characterized in vitro. Then, the NT-3-loaded sutures were tested in a complete SCI model. Rats were analyzed for functional improvement and axonal growth into the grafts. The CaP-coated sutures exhibited a burst release of NT-3, followed by a sustained release for at least 20 days. Functionally, the rats with PNGs + NT-3-loaded sutures and the rats treated with PNGs scored significantly higher than controls on day 56 postoperatively. However, functional scores in rats treated with PNGs + NT-3-loaded suture were not significantly different from those of rats treated with PNGs alone. Cholera toxin subunit B (CTB) labeling rostral to the graft was not observed in any controls, but CTB labeling rostral to the graft was observed in almost all rats that had had a PNG. Neurofilament labeling on transverse sections of the graft revealed that the rats treated with the NT-3-loaded sutures had significantly more axons per graft than rats treated with an NT-3 injection and rats without NT-3. These data demonstrate that PNGs serve as scaffolds for axonal growth after SCI and that CaP-coated sutures can efficiently release NT-3 to increase axonal regeneration. © 2016 Wiley Periodicals, Inc. PMID:27015737

  4. Alteration of neurotrophins in the hippocampus and cerebral cortex of young rats exposed to chlorpyrifos and methyl parathion.

    PubMed

    Betancourt, Angela M; Filipov, Nikolay M; Carr, Russell L

    2007-12-01

    Exposure to either chlorpyrifos (CPS) or methyl parathion (MPS) results in the inhibition of acetylcholinesterase and leads to altered neuronal activity which normally regulates critical genes such as the neurotrophins nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF). The effects of postnatal exposure to CPS and MPS on the expression of messenger RNA (mRNA) and protein levels for NGF and BDNF were investigated in the frontal cerebral cortex (cortex) and hippocampus of rats. Oral administration of CPS (4.0 or 6.0 mg/kg), MPS (0.6 or 0.9 mg/kg), or the safflower oil vehicle was performed daily from postnatal day 10 (PND10) through PND20. Exposure induced significant effects on growth and cholinesterase activity. Increased NGF protein levels were observed in the hippocampus but not the cortex on PND20 with some reduction occurring on PND28 in both regions. These changes did not correlate with the changes in NGF mRNA. BDNF mRNA was increased in both regions on PND20 and PND28, whereas BDNF protein levels were increased on PND20. On PND12, c-fos mRNA, a marker of neuronal activation, was increased in both regions. Total BDNF protein was increased in the hippocampus but decreased in the cortex. No changes in NGF protein were observed. These results indicate that repeated developmental OP exposure during the postnatal period alters NGF and BDNF in the cortex and the hippocampus and the patterns of these alterations differ between regions. PMID:17893397

  5. Stimulation of the protein tyrosine kinase c-Yes but not c-Src by neurotrophins in human brain-metastatic melanoma cells.

    PubMed

    Marchetti, D; Parikh, N; Sudol, M; Gallick, G E

    1998-06-25

    The c-Yes proto-oncogene (pp62c-Yes) encodes a non-receptor-type protein tyrosine kinase (NRPTK) of the Src family. c-Yes activities and protein levels are elevated in human melanoma and melanocyte cell lines. Because the neurotrophins (NT) are important in the progression of melanoma to the brain-metastatic phenotype, we determined whether NT stimulate c-Yes activity in human MeWo melanoma cells and two variant sublines with opposite metastatic capabilities, 3 S 5 and 70W. The highly brain-metastatic 70W subline had an intrinsically higher c-Yes activity than parental MeWo or poorly metastatic 3 S 5 cells. c-Yes kinase was further induced by the prototypic human NT, nerve growth factor (NGF) in a dose and time-dependent manner. In contrast, c-Src activity (pp60-Src) was similar in all these cells and unaffected by NGF exposure. Additionally, human NGF and neurotrophin-3 stimulated c-Yes in brain-metastatic 70W cells. The magnitude of c-Yes activation correlated with the degree of invasion of 70 W cells following incubation of these neurotrophins. To further examine NT stimulation of c-Yes in melanoma cells, three additional cell lines were examined. Metastatic TXM-13 and TXM-18 increased c-Yes activity in response to NGF. In contrast, no increase was observed in low-metastatic TXM-40 cells. Together, these data suggest that altered c-Yes expression may play a role in the malignant progression of the human melanocyte towards the brain-metastatic phenotype and that NT enhance the activity of c-Yes in signaling penetration into the matrix of NT-rich stromal microenvironments such as the brain. PMID:9681823

  6. Myelin-associated glycoprotein modulates apoptosis of motoneurons during early postnatal development via NgR/p75NTR receptor-mediated activation of RhoA signaling pathways

    PubMed Central

    Palandri, A; Salvador, V R; Wojnacki, J; Vivinetto, A L; Schnaar, R L; Lopez, P H H

    2015-01-01

    Myelin-associated glycoprotein (MAG) is a minor constituent of nervous system myelin, selectively expressed on the periaxonal myelin wrap. By engaging multiple axonal receptors, including Nogo-receptors (NgRs), MAG exerts a nurturing and protective effect the axons it ensheaths. Pharmacological activation of NgRs has a modulatory role on p75NTR-dependent postnatal apoptosis of motoneurons (MNs). However, it is not clear whether this reflects a physiological role of NgRs in MN development. NgRs are part of a multimeric receptor complex, which includes p75NTR, Lingo-1 and gangliosides. Upon ligand binding, this multimeric complex activates RhoA/ROCK signaling in a p75NTR-dependent manner. The aim of this study was to analyze a possible modulatory role of MAG on MN apoptosis during postnatal development. A time course study showed that Mag-null mice suffer a loss of MNs during the first postnatal week. Also, these mice exhibited increased susceptibility in an animal model of p75NTR-dependent MN apoptosis induced by nerve-crush injury, which was prevented by treatment with a soluble form of MAG (MAG-Fc). The protective role of MAG was confirmed in in vitro models of p75NTR-dependent MN apoptosis using the MN1 cell line and primary cultures. Lentiviral expression of shRNA sequences targeting NgRs on these cells abolished protection by MAG-Fc. Analysis of RhoA activity using a FRET-based RhoA biosensor showed that MAG-Fc activates RhoA. Pharmacological inhibition of p75NTR/RhoA/ROCK pathway, or overexpression of a p75NTR mutant unable to activate RhoA, completely blocked MAG-Fc protection against apoptosis. The role of RhoA/ROCK signaling was further confirmed in the nerve-crush model, where pretreatment with ROCK inhibitor Y-27632 blocked the pro-survival effect of MAG-Fc. These findings identify a new protective role of MAG as a modulator of apoptosis of MNs during postnatal development by a mechanism involving the p75NTR/RhoA/ROCK signaling pathway. Also, our results

  7. Neurotransmitters, neuromodulators, and neurotrophin receptors in the gut of pantex, a hybrid sparid fish (Pagrus major x Dentex dentex). Localizations in the enteric nervous and endocrine systems.

    PubMed

    Radaelli, G; Domeneghini, C; Arrighi, S; Castaldo, L; Lucini, C; Mascarello, F

    2001-07-01

    The gut of Pantex, a sparid hybrid fish (Pagrus major x Dentex dentex) with a great potential importance for the Italian aquaculture, was histochemically and immunohistochemically investigated in order to evidence components of the intramural nervous and diffuse endocrine systems. The general structural aspects of the intramural nervous system were shown by the Nissl-thionin staining. As in most other fish, it was only organized in the myenteric plexus. Acetylcholinesterase (AChE) activity was observed in both nerve cell bodies and terminals all along the gut. The NADPH-diaphorase reactivity too, possibly linked to the synthesis and release of nitric oxide, was present in nerve cell bodies and nerve terminals of the oesophagus, stomach and intestine. In addition, the intramural nervous system was shown to contain Trk (tyrosinekinase) receptors for neurotrophin, as evidenced by Trk A-, Trk B- and Trk C-like immunoreactivities, thus suggesting an involvement of neurotrophin in the function of this system. Trk B- and Trk C-like immunoreactivities were detected in epithelial endocrine cells, too. The additional presence of serotonin- and metenkephalin-like immunoreactivities in numerous endocrine cells in the epithelial layers of the stomach and intestine was showed. PMID:11510976

  8. Amitriptyline Improves Motor Function via Enhanced Neurotrophin Signaling and Mitochondrial Functions in the Murine N171-82Q Huntington Disease Model*

    PubMed Central

    Cong, Wei-Na; Chadwick, Wayne; Wang, Rui; Daimon, Caitlin M.; Cai, Huan; Amma, Jennifer; Wood, William H.; Becker, Kevin G.; Martin, Bronwen; Maudsley, Stuart

    2015-01-01

    Huntington disease (HD) is a neurodegenerative disorder characterized by progressive motor impairment and cognitive alterations. Hereditary HD is primarily caused by the expansion of a CAG trinucleotide repeat in the huntingtin (Htt) gene, which results in the production of mutant huntingtin protein (mHTT) with an expanded amino-terminal polyglutamine (poly(Q)) stretch. Besides pathological mHTT aggregation, reduced brain-derived neurotrophic factor (BDNF) levels, impaired neurotrophin signaling, and compromised mitochondrial functions also contribute to the deleterious progressive etiology of HD. As a well tolerated Food and Drug Administration-approved antidepressant, amitriptyline (AMI) has shown efficacy in treating neurodegenerative murine models via potentiation of BDNF levels and amelioration of alterations in neurotrophin signaling pathways. In this study, we observed profound improvements in the motor coordination of AMI-treated N171-82Q HD model mice. The beneficial effects of AMI treatment were associated with its ability to reduce mHTT aggregation, potentiation of the BDNF-TrkB signaling system, and support of mitochondrial integrity and functionality. Our study not only provides preclinical evidence for the therapeutic potency of AMI in treating HD, but it also represents an important example of the usefulness of additional pharmacogenomic profiling of pre-existing drugs for novel therapeutic effects with often intractable pathological scenarios. PMID:25505248

  9. The pro-neurotrophin receptor sortilin is a major neuronal APOE receptor for catabolism of amyloid-β peptide in the brain

    PubMed Central

    Carlo, Anne-Sophie; Gustafsen, Camilla; Mastrobuoni, Guido; Nielsen, Morten S.; Burgert, Tilman; Hartl, Daniela; Rohe, Michael; Nykjaer, Anders; Herz, Joachim; Heeren, Joerg; Kempa, Stefan; Petersen, Claus Munck; Willnow, Thomas E.

    2013-01-01

    Apolipoprotein (APO) E is the major risk factor for sporadic Alzheimer disease. Among other functions, APOE is proposed to sequester neurotoxic amyloid-β peptides (Aβ) in the brain, delivering them to cellular catabolism via neuronal APOE receptors. Still, the receptors involved in this process remain controversial. Here, we identified the pro-neurotrophin receptor sortilin as major endocytic pathway for clearance of APOE/Aβ complexes in neurons. Sortilin binds APOE with high affinity. Lack of receptor expression in mice results in accumulation of APOE and of Aβ in the brain, and in aggravated plaque burden. Also, primary neurons lacking sortilin exhibit significantly impaired uptake of APOE/Aβ complexes despite proper expression of other APOE receptors. In spite of higher than normal brain APOE levels, sortilin-deficient animals display anomalies in brain lipid metabolism (e.g., accumulation of sulfatides) seen in APOE-deficient mice, indicating functional deficiency in cellular APOE uptake pathways. Taken together, our findings identified sortilin as an essential neuronal pathway for APOE-containing lipoproteins in vivo and suggest an intriguing link between Aβ catabolism and pro-neurotrophin signaling converging on this receptor. PMID:23283348

  10. Evaluation of oral care to prevent oral mucositis in estrogen receptor-positive metastatic breast cancer patients treated with everolimus (Oral Care-BC): randomized controlled phase III trial.

    PubMed

    Niikura, Naoki; Ota, Yoshihide; Hayashi, Naoki; Naito, Mariko; Kashiwabara, Kosuke; Watanabe, Ken-Ichi; Yamashita, Toshinari; Mukai, Hirofumi; Umeda, Masahiro

    2016-09-01

    This is a randomized, multi-center, open-label, phase III study to evaluate the efficacy of professional oral care in preventing oral mucositis induced by everolimus in postmenopausal estrogen receptor-positive metastatic breast cancer. Patients will be randomized into professional oral care and control groups (1:1 ratio). All patients will receive everolimus with exemestane and will continue everolimus until disease progression. In the professional oral care group, patients will receive teeth surface cleaning, scaling and tongue cleaning before starting everolimus, and will continue to receive professional oral care weekly from oral surgeons throughout the 8 week treatment. In the control group, patients will brush their own teeth and gargle with 0.9% sodium chloride solution or water. The primary endpoint is the incidence of all grades of oral mucositis. Target accrual is 200 patients with a two-sided type I error rate of 5% and 80% power to detect 25% risk reduction. PMID:27365521

  11. Dissociation of TNF-alpha cytotoxic and proinflammatory activities by p55 receptor- and p75 receptor-selective TNF-alpha mutants.

    PubMed Central

    Barbara, J A; Smith, W B; Gamble, J R; Van Ostade, X; Vandenabeele, P; Tavernier, J; Fiers, W; Vadas, M A; Lopez, A F

    1994-01-01

    Human tumour necrosis factor alpha (TNF-alpha) is a pleiotropic cytokine capable of killing mammalian tumour cells in vitro and in vivo, and of enhancing the proinflammatory activity of leucocytes and endothelium, the latter effects limiting its usage as an antitumour agent in humans. Using TNF-alpha mutants with a selective capacity to bind to the TNF p55 receptor (TNFR55) or to the p75 receptor (TNFR75) we show here that these two major activities of TNF-alpha can be dissociated. The TNFR55-selective mutants (R32W, E146K and R32W-S86T) which bind poorly to TNFR75 displayed similar potency to wild-type TNF in causing cytotoxicity of a human laryngeal carcinoma-derived cell line (HEp-2) and cytostasis in a human leukaemic cell line (U937). However, these TNFR55-selective mutants exhibited lower proinflammatory activity than wild-type TNF. Specifically, TNF-alpha's priming of human neutrophils for superoxide production and antibody-dependent cell-mediated cytotoxicity, platelet-activating factor synthesis and adhesion to endothelium were reduced by up to 170-fold. Activation of human endothelial cell functions represented by human umbilical venular endothelial cell (HUVEC) adhesiveness for neutrophils, E-selectin expression, neutrophil transmigration and IL-8 secretion were also reduced by up to 280-fold. On the other hand, D143F, a TNFR75-selective mutant tested either alone or in combination with TNFR55-selective mutants, did not stimulate these activities despite being able to cause cytokine production in TNFR75-transfected PC60 cells.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7509279

  12. Tumor necrosis factor alpha and interleukin-1 alpha stimulate late shedding of p75 TNF receptors but not p55 TNF receptors from human monocytes.

    PubMed

    Joyce, D A; Steer, J H

    1995-11-01

    Soluble receptors for TNF (sTNF-R) are present at elevated concentrations in the synovial fluid of patients with rheumatoid arthritis. They are presumably released by cells of the synovial membrane, including the monocyte-derived synovial macrophages. Cytokines from the synovium, including IL-1 and TNF-alpha, may stimulate release. We therefore examined the release of sTNF-R from monocytes exposed to IL-1 and TNF-alpha. Elutriator-purified human blood monocytes spontaneously released both the p75 and the p55 sTNF-R (1011 +/- 199 and 177 +/- 20 pg/10(6) cells, respectively, mean +/- SEM) during 48 h of in vitro culture. TNF-alpha and IL-1 alpha induced time- and concentration-dependent increases in the release of sTNF-R75 from monocytes, but neither had a measurable effect on the release of sTNF-R55. The release of sTNF-R75 was inhibited by cycloheximide. Neither lymphocytes nor polymorphonuclear leukocytes (PMN) released measurable sTNF-R spontaneously or in response to stimulation with IL-1 alpha, but TNF-alpha stimulated the release of small amounts of sTNF-R75 by PMN. The timing, cycloheximide sensitivity, and selectivity of stimulated release of TNF-R75 by monocytes are consistent with previous observations on other cell types of late (8-20 h) increased synthesis and turnover of cell surface TNF-R75, but not TNF-R55, after stimulation with TNF-alpha or IL-1. These observations help to explain why elevated levels of sTNF-R in synovial fluid coexist with enhanced expression of cell surface TNF-R on synovial macrophages in rheumatoid arthritis. PMID:8590306

  13. Dtrk, a Drosophila gene related to the trk family of neurotrophin receptors, encodes a novel class of neural cell adhesion molecule.

    PubMed Central

    Pulido, D; Campuzano, S; Koda, T; Modolell, J; Barbacid, M

    1992-01-01

    We report the identification and molecular characterization of Dtrk, a Drosophila gene encoding a receptor tyrosine kinase highly related to the trk family of mammalian neurotrophin receptors. The product of the Dtrk gene, gp160Dtrk, is dynamically expressed during Drosophila embryogenesis in several areas of the developing nervous system, including neurons and fasciculating axons. gp160Dtrk has structural homology with neural cell adhesion molecules of the immunoglobulin superfamily and promotes cell adhesion in a homophilic, Ca2+ independent manner. More importantly, this adhesion process specifically activates its tyrosine protein kinase activity. These findings suggest that gp160Dtrk represents a new class of neural cell adhesion molecules that may regulate neuronal recognition and axonal guidance during the development of the Drosophila nervous system. Images PMID:1371458

  14. Neurotrophins Acting Via TRKB Receptors Activate the JAGGED1-NOTCH2 Cell-Cell Communication Pathway to Facilitate Early Ovarian Development

    PubMed Central

    Dorfman, Mauricio D.; Kerr, Bredford; Garcia-Rudaz, Cecilia; Paredes, Alfonso H.; Dissen, Gregory A.

    2011-01-01

    Tropomyosin-related kinase (TRK) receptor B (TRKB) mediates the supportive actions of neurotrophin 4/5 and brain-derived neurotrophic factor on early ovarian follicle development. Absence of TRKB receptors reduces granulosa cell (GC) proliferation and delays follicle growth. In the present study, we offer mechanistic insights into this phenomenon. DNA array and quantitative PCR analysis of ovaries from TrkB-null mice revealed that by the end of the first week of postnatal life, Jagged1, Hes1, and Hey2 mRNA abundance is reduced in the absence of TRKB receptors. Although Jagged1 encodes a NOTCH receptor ligand, Hes1 and Hey2 are downstream targets of the JAGGED1-NOTCH2 signaling system. Jagged1 is predominantly expressed in oocytes, and the abundance of JAGGED1 is decreased in TrkB−/− oocytes. Lack of TRKB receptors also resulted in reduced expression of c-Myc, a NOTCH target gene that promotes entry into the cell cycle, but did not alter the expression of genes encoding core regulators of cell-cycle progression. Selective restoration of JAGGED1 synthesis in oocytes of TrkB−/− ovaries via lentiviral-mediated transfer of the Jagged1 gene under the control of the growth differentiation factor 9 (Gdf9) promoter rescued c-Myc expression, GC proliferation, and follicle growth. These results suggest that neurotrophins acting via TRKB receptors facilitate early follicle growth by supporting a JAGGED1-NOTCH2 oocyte-to-GC communication pathway, which promotes GC proliferation via a c-MYC-dependent mechanism. PMID:22028443

  15. Molecular evolution of vertebrate neurotrophins: co-option of the highly conserved nerve growth factor gene into the advanced snake venom arsenalf.

    PubMed

    Sunagar, Kartik; Fry, Bryan Grieg; Jackson, Timothy N W; Casewell, Nicholas R; Undheim, Eivind A B; Vidal, Nicolas; Ali, Syed A; King, Glenn F; Vasudevan, Karthikeyan; Vasconcelos, Vitor; Antunes, Agostinho

    2013-01-01

    Neurotrophins are a diverse class of structurally related proteins, essential for neuronal development, survival, plasticity and regeneration. They are characterized by major family members, such as the nerve growth factors (NGF), brain-derived neurotrophic factors (BDNF) and neurotrophin-3 (NT-3), which have been demonstrated here to lack coding sequence variations and follow the regime of negative selection, highlighting their extremely important conserved role in vertebrate homeostasis. However, in stark contrast, venom NGF secreted as part of the chemical arsenal of the venomous advanced snake family Elapidae (and to a lesser extent Viperidae) have characteristics consistent with the typical accelerated molecular evolution of venom components. This includes a rapid rate of diversification under the significant influence of positive-selection, with the majority of positively-selected sites found in the secreted β-polypeptide chain (74%) and on the molecular surface of the protein (92%), while the core structural and functional residues remain highly constrained. Such focal mutagenesis generates active residues on the toxin molecular surface, which are capable of interacting with novel biological targets in prey to induce a myriad of pharmacological effects. We propose that caenophidian NGFs could participate in prey-envenoming by causing a massive release of chemical mediators from mast cells to mount inflammatory reactions and increase vascular permeability, thereby aiding the spread of other toxins and/or by acting as proapoptotic factors. Despite their presence in reptilian venom having been known for over 60 years, this is the first evidence that venom-secreted NGF follows the molecular evolutionary pattern of other venom components, and thus likely participates in prey-envenomation. PMID:24312363

  16. Molecular Evolution of Vertebrate Neurotrophins: Co-Option of the Highly Conserved Nerve Growth Factor Gene into the Advanced Snake Venom Arsenalf

    PubMed Central

    Sunagar, Kartik; Fry, Bryan Grieg; Jackson, Timothy N. W.; Casewell, Nicholas R.; Undheim, Eivind A. B.; Vidal, Nicolas; Ali, Syed A.; King, Glenn F.; Vasudevan, Karthikeyan; Vasconcelos, Vitor; Antunes, Agostinho

    2013-01-01

    Neurotrophins are a diverse class of structurally related proteins, essential for neuronal development, survival, plasticity and regeneration. They are characterized by major family members, such as the nerve growth factors (NGF), brain-derived neurotrophic factors (BDNF) and neurotrophin-3 (NT-3), which have been demonstrated here to lack coding sequence variations and follow the regime of negative selection, highlighting their extremely important conserved role in vertebrate homeostasis. However, in stark contrast, venom NGF secreted as part of the chemical arsenal of the venomous advanced snake family Elapidae (and to a lesser extent Viperidae) have characteristics consistent with the typical accelerated molecular evolution of venom components. This includes a rapid rate of diversification under the significant influence of positive-selection, with the majority of positively-selected sites found in the secreted β-polypeptide chain (74%) and on the molecular surface of the protein (92%), while the core structural and functional residues remain highly constrained. Such focal mutagenesis generates active residues on the toxin molecular surface, which are capable of interacting with novel biological targets in prey to induce a myriad of pharmacological effects. We propose that caenophidian NGFs could participate in prey-envenoming by causing a massive release of chemical mediators from mast cells to mount inflammatory reactions and increase vascular permeability, thereby aiding the spread of other toxins and/or by acting as proapoptotic factors. Despite their presence in reptilian venom having been known for over 60 years, this is the first evidence that venom-secreted NGF follows the molecular evolutionary pattern of other venom components, and thus likely participates in prey-envenomation. PMID:24312363

  17. Spinal electro-magnetic stimulation combined with transgene delivery of neurotrophin NT-3 and exercise: novel combination therapy for spinal contusion injury.

    PubMed

    Petrosyan, Hayk A; Alessi, Valentina; Hunanyan, Arsen S; Sisto, Sue A; Arvanian, Victor L

    2015-11-01

    Our recent terminal experiments revealed that administration of a single train of repetitive spinal electromagnetic stimulation (sEMS; 35 min) enhanced synaptic plasticity in spinal circuitry following lateral hemisection spinal cord injury. In the current study, we have examined effects of repetitive sEMS applied as a single train and chronically (5 wk, every other day) following thoracic T10 contusion. Chronic studies involved examination of systematic sEMS administration alone and combined with exercise training and transgene delivery of neurotrophin [adeno-associated virus 10-neurotrophin 3 (AAV10-NT3)]. Electrophysiological intracellular/extracellular recordings, immunohistochemistry, behavioral testing, and anatomical tracing were performed to assess effects of treatments. We found that administration of a single sEMS train induced transient facilitation of transmission through preserved lateral white matter to motoneurons and hindlimb muscles in chronically contused rats with effects lasting for at least 2 h. These physiological changes associated with increased immunoreactivity of GluR1 and GluR2/3 glutamate receptors in lumbar neurons. Systematic administration of sEMS alone for 5 wk, however, was unable to induce cumulative improvements of transmission in spinomuscular circuitry or improve impaired motor function following thoracic contusion. Encouragingly, chronic administration of sEMS, followed by exercise training (running in an exercise ball and swimming), induced the following: 1) sustained strengthening of transmission to lumbar motoneurons and hindlimb muscles, 2) better retrograde transport of anatomical tracer, and 3) improved locomotor function. Greatest improvements were seen in the group that received exercise combined with sEMS and AAV-NT3. PMID:26424579

  18. Prospective Clinical Utility Study of the Use of the 21-Gene Assay in Adjuvant Clinical Decision Making in Women With Estrogen Receptor-Positive Early Invasive Breast Cancer: Results From the SWITCH Study

    PubMed Central

    Pivot, Xavier B.; Jacot, William; Naman, Hervé L.; Spaeth, Dominique; Misset, Jean-Louis; Largillier, Rémy; Sautiere, Jean-Loup; de Roquancourt, Anne; Pomel, Christophe; Rouanet, Philippe; Rouzier, Roman; Penault-Llorca, Frederique M.

    2015-01-01

    Background. The 21-gene Oncotype DX Recurrence Score assay is a validated assay to help decide the appropriate treatment for estrogen receptor-positive (ER+), early-stage breast cancer (EBC) in the adjuvant setting. The choice of adjuvant treatments might vary considerably in different countries according to various treatment guidelines. This prospective multicenter study is the first to assess the impact of the Oncotype DX assay in the French clinical setting. Methods. A total of 100 patients with ER+, human epidermal growth factor receptor 2-negative EBC, and node-negative (pN0) disease or micrometastases in up to 3 lymph nodes (pN1mi) were enrolled. Treatment recommendations, physicians’ confidence before and after knowing the Recurrence Score value, and physicians’ perception of the assay were recorded. Results. Of the 100 patients, 95 were evaluable (83 pN0, 12 pN1mi). Treatment recommendations changed in 37% of patients, predominantly from chemoendocrine to endocrine treatment alone. The proportion of patients recommended chemotherapy decreased from 52% pretest to 25% post-test. Of patients originally recommended chemotherapy, 61% were recommended endocrine treatment alone after receiving the Recurrence Score result. For both pN0 and pN1mi patients, post-test recommendations appeared to follow the Recurrence Score result for low and high values. Physicians’ confidence improved significantly. Conclusion. These are the first prospective data on the impact of the Oncotype DX assay on adjuvant treatment decisions in France. Using the assay was associated with a significant change in treatment decisions and an overall reduction in chemotherapy use. These data are consistent with those presented from European and non-European studies. Implications for Practice: This study shows that in estrogen receptor-positive, human epidermal growth factor receptor 2-negative early breast cancer (either node-negative or with micrometastases in up to 3 lymph nodes

  19. Lower-dose (6 mg Daily) versus High-dose (30 mg Daily) Oral Estradiol Therapy of Hormone-receptor-positive, Aromatase-inhibitor-resistant Advanced Breast Cancer: A Randomized Phase 2 Study

    PubMed Central

    Ellis, Matthew J.; Gao, Feng; Dehdashti, Farrokh; Jeffe, Donna B.; Marcom, P. Kelly; Carey, Lisa A.; Dickler, Maura N.; Silverman, Paula; Fleming, Gini F.; Kommareddy, Aruna; Jamalabadi-Majidi, Shohreh; Crowder, Robert; Siegel, Barry A

    2012-01-01

    Context Estrogen deprivation therapy with aromatase inhibitors (AI) has been hypothesized to paradoxically sensitize hormone-receptor-positive breast cancer tumor cells to low-dose estradiol therapy. Objective To determine if estradiol 6-mg daily is a viable endocrine therapy for postmenopausal women with advanced AI-resistant hormone-receptor-positive breast cancer. Design, Setting and Patients A randomized Phase 2 trial of 6-mg versus 30-mg oral estradiol daily opened in April 2004 and was closed to enrollment in February 2008 (NCT00324259). Eligible patients had metastatic breast cancer treated with an AI with at least 24 weeks progression-free survival, or relapse after two or more years of adjuvant AI. Patients at high risk of estradiol-related adverse events were excluded. Main Outcome Measures The primary endpoint was clinical benefit rate – CBR (response plus stable disease at 24 weeks). Secondary outcomes included toxicity, progression-free survival (PFS), time to treatment failure (TTF), quality of life (QOL) and the predictive properties of the FDG-PET metabolic flare reaction. Results 66 patients were enrolled. The grade 3+ adverse event rate on the 30-mg arm (11/32; 95% CI: 23%–47%) was higher than that in 6-mg arm (4/34; 95% CI: 5%–22%) (P=.03). CBRs were 28% (9/32; 95% CI: 18% – 41%) on the 30-mg arm and 29% (10/34; 95% CI: 19% – 42%) on the 6-mg arm. An estradiol44 stimulated increase in FDG uptake of ≥12% (prospectively defined) was predictive of response (positive predictive value of 80%; 95% CI: 61%–92%). Seven patients with estradiol-sensitive disease were retreated with AI upon estradiol progression, with two PR and one SD, suggesting resensitization to estrogen deprivation. Conclusions In women with advanced breast cancer and acquired resistance to AI, an estradiol dose of 6-mg daily provided a similar CBR as 30-mg daily, with fewer serious adverse events. The efficacy of treatment with the lower dose should be further examined

  20. Inverse relationship between heat stable enterotoxin-b induced fluid accumulation and adherence of F4ac-positive enterotoxigenic Escherichia coli in ligated jejunal loops of F4ab/ac fimbria receptor-positive swine.

    PubMed

    Erume, Joseph; Wijemanne, Prageeth; Berberov, Emil M; Kachman, Stephen D; Oestmann, Daniel J; Francis, David H; Moxley, Rodney A

    2013-01-25

    Heat-labile enterotoxin (LT) produced by enterotoxigenic Escherichia coli (ETEC) increases bacterial adherence to porcine enterocytes in vitro and enhances small intestinal colonization in swine. Heat-stable enterotoxin-b (STb) is not known to affect colonization; however, through an induction of net fluid accumulation it might reduce bacterial adherence. The relationship between fluid accumulation and bacterial adherence in jejunal loops inoculated with ETEC strains that produce LT, STb, both, or neither toxin was studied. Ligated jejunal loops were constructed in weaned Yorkshire pigs in two independent experiments (Exp. 1, n=5, 8-week-old; Exp. 2, n=6, 6-8-week-old). Each pig was inoculated with six F4ac(+)E. coli strains: (1) LT(+), STb(+) parent (WAM2317); (2) STb(-) (ΔestB) mutant (MUN297); (3) MUN297 complemented with STb (MUN298); (4) LT(-) STb(-) (ΔeltAB ΔestB) mutant (MUN300); (5) MUN300 complemented with LT (MUN301); and (6) 1836-2 (non-enterotoxigenic, wild-type). Pigs were confirmed to be K88 (F4)ab/ac receptor-positive in Exp. 2 by testing for intestinal mucin-type glycoproteins and inferred to be receptor-positive in both Exp. 1 and 2 based on histopathologic evidence of bacterial adherence. Strains that produced STb induced marked fluid accumulation with the response (ml/cm) to WAM2317 and MUN298 significantly greater than that to the other strains (P<0.0001). Conversely, bacterial adherence scores based on immunohistochemistry and CFU/g of washed mucosa were both lowest in the strains that expressed STb and highest in those that did not. For the two experiments combined, the Pearson correlation coefficient (R) between fluid volume (ml/cm) and log CFU per gram was -0.57021 (P<0.0001); R(2)=0.3521 (n=197). These results support the hypothesis that enterotoxin-induced fluid accumulation flushes progeny organisms into the lumen of the bowel, thereby increasing the likelihood of fecal shedding and transmission of the pathogen to new hosts. PMID

  1. Targeted Radiotherapy of Estrogen Receptor Positive Tumors

    SciTech Connect

    Raghavan Rajagopalan

    2006-08-31

    The overall objectives of the proposal were to develop estrogen receptor (ER) binding small molecule radiopharmaceuticals for targeted radiotherapy of ER positive (ER+) tumors. In particular, this proposal focused on embedding a {sup 186,188}Re or a {sup 32}P radionuclide into an estrogen steroidal framework by isosteric substitution such that the resulting structure is topologically similar to the estrogen (estrogen mimic). The estrogen mimic molecules expected to bind to the ER and exhibit biodistribution akin to that of native estrogen due to structural mimicry. It is anticipated that the {sup 186,188}Re- or a {sup 32}P-containing estrogen mimics will be useful for targeted molecular radiotherapy of ER+ tumors. It is well established that the in vivo target tissue uptake of estrogen like steroidal molecules is related to the binding of the steroids to sex hormone binding globulin (SHBG). SHBG is important in the uptake of estrogens and testosterone in target tissues by SHBG receptors on the cell surface. However, hitherto the design of estrogen like small molecule radiopharmaceuticals was focused on optimizing ER binding characteristics without emphasis on SHBG binding properties. Consequently, even the molecules with good ER affinity in vitro, performed poorly in biodistribution studies. Based on molecular modeling studies the proposal focused on developing estrogen mimics 1-3 which were topologically similar to native estrogens, and form hydrogen bonds in ER and SHBG in the same manner as those of native estrogens. To this end the technical objectives of the proposal focused on synthesizing the rhenium-estrone and estradiol mimics 1 and 2 respectively, and phosphorous estradiol mimic 3 and to assess their stability and in vitro binding characteristics to ER and SHBG.

  2. Learning receptor positions from imperfectly known motions

    NASA Technical Reports Server (NTRS)

    Ahumada, Albert J., Jr.; Mulligan, Jeffrey B.

    1990-01-01

    An algorithm is described for learning image interpolation functions for sensor arrays whose sensor positions are somewhat disordered. The learning is based on failures of translation invariance, so it does not require knowledge of the images being presented to the visual system. Previously reported implementations of the method assumed the visual system to have precise knowledge of the translations. It is demonstrated that translation estimates computed from the imperfectly interpolated images can have enough accuracy to allow the learning process to converge to a correct interpolation.

  3. Design and Synthesis of Systemically Active Metabotropic Glutamate Subtype-2 and -3 (mGlu2/3) Receptor Positive Allosteric Modulators (PAMs): Pharmacological Characterization and Assessment in a Rat Model of Cocaine Dependence

    PubMed Central

    2015-01-01

    As part of our ongoing small-molecule metabotropic glutamate (mGlu) receptor positive allosteric modulator (PAM) research, we performed structure–activity relationship (SAR) studies around a series of group II mGlu PAMs. Initial analogues exhibited weak activity as mGlu2 receptor PAMs and no activity at mGlu3. Compound optimization led to the identification of potent mGlu2/3 selective PAMs with no in vitro activity at mGlu1,4–8 or 45 other CNS receptors. In vitro pharmacological characterization of representative compound 44 indicated agonist-PAM activity toward mGlu2 and PAM activity at mGlu3. The most potent mGlu2/3 PAMs were characterized in assays predictive of ADME/T and pharmacokinetic (PK) properties, allowing the discovery of systemically active mGlu2/3 PAMs. On the basis of its overall profile, compound 74 was selected for behavioral studies and was shown to dose-dependently decrease cocaine self-administration in rats after intraperitoneal administration. These mGlu2/3 receptor PAMs have significant potential as small molecule tools for investigating group II mGlu pharmacology. PMID:24735492

  4. Calcineurin-NFAT Signaling and Neurotrophins Control Transformation of Myosin Heavy Chain Isoforms in Rat Soleus Muscle in Response to Aerobic Treadmill Training

    PubMed Central

    Liu, Wenfeng; Chen, Gan; Li, Fanling; Tang, Changfa; Yin, Dazhong

    2014-01-01

    This study elucidated the role of CaN-NFAT signaling and neurotrophins on the transformation of myosin heavy chain isoforms in the rat soleus muscle fiber following aerobic exercise training. To do so, we examined the content and distribution of myosin heavy chain (MyHC) isoforms in the rat soleus muscle fiber, the activity of CaN and expression of NFATc1 in these fibers, and changes in the expression of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neutrophin-3 (NT-3) in the soleus and striatum following high-and medium-intensity aerobic treadmill training. Specific pathogen-free 2 month old male Sprague-Dawley (SD) rats were randomly divided into three groups: Control group (Con, n = 8), moderate-intensity aerobic exercise group (M-Ex, n = 8) and high-intensity aerobic exercise group (H-Ex, n = 8). We used ATPase staining to identify the muscle fiber type I and II, SDS-PAGE to separate and analyze the isoforms MyHCI, MyHCIIA, MyHCIIB and MyHCIIx, and performed western blots to determine the expression of NFATc1, NGF, BDNF and NT-3. CaN activity was measured using a colorimetric assay. In the soleus muscle, 8 weeks of moderate-intensity exercise can induce transformation of MyHC IIA and MyHC IIB to MyHC IIX and MyHC I (p < 0.01), while high-intensity treadmill exercise can induce transform MyHC IIx to MyHC IIB, MyHC IIA and MyHC I (p < 0.01). In comparison to the control group, CaN activity and NFATcl protein level were significantly increased in both the M-Ex and H-Ex groups (p < 0.05, p < 0.01), with a more pronounced upregulation in the M-Ex group (p < 0.05). Eight weeks of moderate- and high-intensity aerobic exercise induced the expression of NGF, BDNF and NT-3 in the soleus muscle and the striatum (p < 0.01), with the most significant increase in the H-Ex group (p < 0.01). In the rat soleus muscle, (1) CaN–NFATcl signaling contributes to the conversion of MyHC I isoform in response to moderate-intensity exercise; (2) Neurotrophins

  5. Survival, Differentiation, and Neuroprotective Mechanisms of Human Stem Cells Complexed With Neurotrophin-3-Releasing Pharmacologically Active Microcarriers in an Ex Vivo Model of Parkinson’s Disease

    PubMed Central

    Daviaud, Nicolas; Garbayo, Elisa; Sindji, Laurence; Martínez-Serrano, Alberto; Schiller, Paul C.

    2015-01-01

    Stem cell-based regenerative therapies hold great potential for the treatment of degenerative disorders such as Parkinson’s disease (PD). We recently reported the repair and functional recovery after treatment with human marrow-isolated adult multilineage inducible (MIAMI) cells adhered to neurotrophin-3 (NT3) releasing pharmacologically active microcarriers (PAMs) in hemiparkinsonian rats. In order to comprehend this effect, the goal of the present work was to elucidate the survival, differentiation, and neuroprotective mechanisms of MIAMI cells and human neural stem cells (NSCs), both adhering to NT3-releasing PAMs in an ex vivo organotypic model of nigrostriatal degeneration made from brain sagittal slices. It was shown that PAMs led to a marked increase in MIAMI cell survival and neuronal differentiation when releasing NT3. A significant neuroprotective effect of MIAMI cells adhering to PAMs was also demonstrated. NSCs barely had a neuroprotective effect and differentiated mostly into dopaminergic neuronal cells when adhering to PAM-NT3. Moreover, those cells were able to release dopamine in a sufficient amount to induce a return to baseline levels. Reverse transcription-quantitative polymerase chain reaction and enzyme-linked immunosorbent assay analyses identified vascular endothelial growth factor (VEGF) and stanniocalcin-1 as potential mediators of the neuroprotective effect of MIAMI cells and NSCs, respectively. It was also shown that VEGF locally stimulated tissue vascularization, which might improve graft survival, without excluding a direct neuroprotective effect of VEGF on dopaminergic neurons. These results indicate a prospective interest of human NSC/PAM and MIAMI cell/PAM complexes in tissue engineering for PD. Significance Stem cell-based regenerative therapies hold great potential for the treatment of degenerative disorders such as Parkinson’s disease (PD). The present work elucidates and compares the survival, differentiation, and

  6. Neurotrophin-3 Induces BMP-2 and VEGF Activities and Promotes the Bony Repair of Injured Growth Plate Cartilage and Bone in Rats.

    PubMed

    Su, Yu-Wen; Chung, Rosa; Ruan, Chun-Sheng; Chim, Shek Man; Kuek, Vincent; Dwivedi, Prem P; Hassanshahi, Mohammadhossein; Chen, Ke-Ming; Xie, Yangli; Chen, Lin; Foster, Bruce K; Rosen, Vicki; Zhou, Xin-Fu; Xu, Jiake; Xian, Cory J

    2016-06-01

    Injured growth plate is often repaired by bony tissue causing bone growth defects, for which the mechanisms remain unclear. Because neurotrophins have been implicated in bone fracture repair, here we investigated their potential roles in growth plate bony repair in rats. After a drill-hole injury was made in the tibial growth plate and bone, increased injury site mRNA expression was observed for neurotrophins NGF, BDNF, NT-3, and NT-4 and their Trk receptors. NT-3 and its receptor TrkC showed the highest induction. NT-3 was localized to repairing cells, whereas TrkC was observed in stromal cells, osteoblasts, and blood vessel cells at the injury site. Moreover, systemic NT-3 immunoneutralization reduced bone volume at injury sites and also reduced vascularization at the injured growth plate, whereas recombinant NT-3 treatment promoted bony repair with elevated levels of mRNA for osteogenic markers and bone morphogenetic protein (BMP-2) and increased vascularization and mRNA for vascular endothelial growth factor (VEGF) and endothelial cell marker CD31 at the injured growth plate. When examined in vitro, NT-3 promoted osteogenesis in rat bone marrow stromal cells, induced Erk1/2 and Akt phosphorylation, and enhanced expression of BMPs (particularly BMP-2) and VEGF in the mineralizing cells. It also induced CD31 and VEGF mRNA in rat primary endothelial cell culture. BMP activity appears critical for NT-3 osteogenic effect in vitro because it can be almost completely abrogated by co-addition of the BMP inhibitor noggin. Consistent with its angiogenic effect in vivo, NT-3 promoted angiogenesis in metatarsal bone explants, an effect abolished by co-treatment with anti-VEGF. This study suggests that NT-3 may be an osteogenic and angiogenic factor upstream of BMP-2 and VEGF in bony repair, and further studies are required to investigate whether NT-3 may be a potential target for preventing growth plate faulty bony repair or for promoting bone fracture healing. © 2016

  7. Impact of palbociclib plus letrozole on pain severity and pain interference with daily activities in patients with estrogen receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer as first-line treatment.

    PubMed

    Bell, T; Crown, J P; Lang, I; Bhattacharyya, H; Zanotti, G; Randolph, S; Kim, S; Huang, X; Huang Bartlett, C; Finn, R S; Slamon, D

    2016-05-01

    Background Palbociclib is a recently approved drug for use in combination with letrozole as initial endocrine-based therapy for the treatment of postmenopausal women with advanced estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) breast cancer. This report assesses the impact of palbociclib in combination with letrozole versus letrozole alone on patient-reported outcomes of pain. Methods Palbociclib was evaluated in an open-label, randomized, phase II study (PALOMA-1/TRIO-18) among postmenopausal women with advanced ER+/HER2- breast cancer who had not received prior systemic treatment for their advanced disease. Patients received continuous oral letrozole 2.5 mg daily alone or the same letrozole dose and schedule plus oral palbociclib 125 mg, given once daily for 3 weeks followed by 1 week off over repeated 28-day cycles. The primary study endpoint was investigator-assessed progression-free survival in the intent-to-treat population, and these results have recently been published (Finn et al., Lancet Oncol 2015;16:25-35). One of the key secondary endpoints was the evaluation of pain, as measured using the Brief Pain Inventory (BPI) patient-reported outcome tool. The BPI was administered at baseline and on day 1 of every cycle thereafter until disease progression and/or treatment discontinuation. Clinical trial registration This study is registered with ClinicalTrials.gov (NCT00721409). Results There were no statistically significant differences in Pain Severity or Pain Interference scores of the BPI between the two treatment groups for the overall population or among those with any bone disease at baseline. A limitation of the study is that results were not adjusted for the concomitant use of opioids or other medications used to control pain. Conclusions The addition of palbociclib to letrozole was associated with increased efficacy without negatively impacting pain severity or pain interference with daily activities

  8. Cost-effectiveness of a 21-gene recurrence score assay versus Canadian clinical practice in women with early-stage estrogen- or progesterone-receptor-positive, axillary lymph-node negative breast cancer

    PubMed Central

    2012-01-01

    Background A 21-gene recurrence score (RS) assay may inform adjuvant systematic treatment decisions in women with early stage breast cancer. We sought to investigate the cost effectiveness of using the RS-assay versus current clinical practice (CCP) in women with early-stage estrogen- or progesterone-receptor-positive, axilliary lymph-node negative breast cancer (ER+/ PR + LN- ESBC) from the perspective of the Canadian public healthcare system. Methods We developed a Markov model to project the lifetime clinical and economic consequences of ESBC. We evaluated adjuvant therapy separately in post- and pre-menopausal women with ER+/ PR + LN- ESBC. We assumed that the RS-assay would reclassify pre- and post-menopausal women among risk levels (low, intermediate and high) and guide adjuvant systematic treatment decisions. The model was parameterized using 7 year follow up data from the Manitoba Cancer Registry, cost data from Manitoba administrative databases, and secondary sources. Costs are presented in 2010 CAD. Future costs and benefits were discounted at 5%. Results The RS-assay compared to CCP generated cost-savings in pre-menopausal women and had an ICER of $60,000 per QALY gained in post-menopausal women. The cost effectiveness was most sensitive to the proportion of women classified as intermediate risk by the RS-assay who receive adjuvant chemotherapy and the risk of relapse in the RS-assay model. Conclusions The RS-assay is likely to be cost effective in the Canadian healthcare system and should be considered for adoption in women with ER+/ PR + LN- ESBC. However, ongoing assessment and validation of the assay in real-world clinical practice is warranted. PMID:23031196

  9. Changes over time in the impact of gene-expression profiles on the administration of adjuvant chemotherapy in estrogen receptor positive early stage breast cancer patients: A nationwide study.

    PubMed

    Kuijer, A; Drukker, C A; Elias, S G; Smorenburg, C H; Th Rutgers, E J; Siesling, S; van Dalen, Th

    2016-08-15

    Ten years ago gene-expression profiles were introduced to aid adjuvant chemotherapy decision making in breast cancer. Since then subsequent national guidelines gradually expanded the indication area for adjuvant chemotherapy. In this nation-wide study the evolution of the proportion of patients with estrogen-receptor positive (ER+) tumors receiving adjuvant chemotherapy in relation to gene-expression profile use in patient groups that became newly eligible for chemotherapy according to national guideline changes over time is assessed. Data on all surgically treated early breast cancer patients diagnosed between 2004-2006 and 2012-2014 were obtained from the Netherlands Cancer Registry. ER+/Her2- patients with tumor-characteristics making them eligible for gene-expression testing in both cohorts and a discordant chemotherapy recommendation over time (2004 guideline not recommending and 2012 guideline recommending chemotherapy) were identified. We identified 3,864 patients eligible for gene-expression profile use during both periods. Gene-expression profiles were deployed in 5% and 35% of the patients in the respective periods. In both periods the majority of patients was assigned to a low genomic risk-profile (67% and 69%, respectively) and high adherence rates to the test result were observed (86% and 91%, respectively). Without deploying a gene-expression profile 8% and 52% (p <0.001) of the respective cohorts received chemotherapy while 21% and 28% of these patients received chemotherapy when a gene-expression profile was used (p 0.191). In conclusion, in ER+/Her2- early stage breast cancer patients gene-expression profile use was associated with a consistent proportion of patients receiving chemotherapy despite an adjusted guideline-based recommendation to administer chemotherapy. PMID:27062369

  10. Targeting the cyclin D-cyclin-dependent kinase (CDK) 4/6-retinoblastoma pathway with selective CDK 4/6 inhibitors in hormone receptor-positive breast cancer: rationale, current status, and future directions.

    PubMed

    Spring, Laura; Bardia, Aditya; Modi, Shanu

    2016-01-01

    Dysregulation of the cyclin D-cyclin-dependent kinase (CDK) 4/6-INK4-retinoblastoma (Rb) pathway is an important contributor to endocrine therapy resistance. Recent clinical development of selective inhibitors of CDK4 and CDK6 kinases has led to renewed interest in cell cycle regulators, following experience with relatively non-selective pan-CDK inhibitors that often resulted in limited activity and poor safety profiles in the clinic. The highly selective oral CDK 4/6 inhibitors palbociclib (PD0332991), ribociclib (LEE011), and abemaciclib (LY2835219) are able to inhibit the proliferation of Rb-positive tumor cells and have demonstrated dose-dependent growth inhibition in ER+ breast cancer models. In metastatic breast cancer, all three agents are being explored in combination with endocrine therapy in Phase III studies. Results so far indicated promising efficacy and manageable safety profiles, and led to the FDA approval of palbociclib. Phase II-III studies of these agents, in combination with endocrine therapy, are also underway in early breast cancer in the neoadjuvant and adjuvant settings. Selective CDK 4/6 inhibitors are also being investigated with other targeted agents or chemotherapy in the advanced setting. This article reviews the rationale for targeting cyclin D-CDK 4/6 in hormone receptor-positive (HR+) breast cancer, provides an overview of the available preclinical and clinical data with CDK 4/6 inhibitors in breast cancer to date, and summarizes the main features of ongoing clinical trials of these new agents in breast cancer. Future trials evaluating further combination strategies with CDK 4/6 backbone and translational studies refining predictive biomarkers are needed to help personalize the optimal treatment regimen for individual patients with ER+ breast cancer. PMID:26896604

  11. Endocrine therapy for postmenopausal women with hormone receptor-positive her2-negative advanced breast cancer after progression or recurrence on nonsteroidal aromatase inhibitor therapy: a Canadian consensus statement.

    PubMed

    Pritchard, K I; Gelmon, K A; Rayson, D; Provencher, L; Webster, M; McLeod, D; Verma, S

    2013-02-01

    Approximately 22,700 Canadian women were expected to be diagnosed with breast cancer in 2012. Despite improvements in screening and adjuvant treatment options, a substantial number of postmenopausal women with hormone receptor positive (hr+) breast cancer will continue to develop metastatic disease during or after adjuvant endocrine therapy. Guidance on the selection of endocrine therapy for patients with hr+ disease that is negative for the human epidermal growth factor receptor 2 (her2-) and that has relapsed or progressed on earlier nonsteroidal aromatase inhibitor (nsai) therapy is of increasing clinical importance. Exemestane, fulvestrant, and tamoxifen are approved therapeutic options in this context. Four phase iii trials involving 2876 patients-efect, sofea, confirm, and bolero-2-have assessed the efficacy of various treatment options in this clinical setting. Data from those trials suggest that standard-dose fulvestrant (250 mg monthly) and exemestane are of comparable efficacy, that doubling the dose of fulvestrant from 250 mg to 500 mg monthly results in a 15% reduction in the risk of progression, and that adding everolimus to exemestane (compared with exemestane alone) results in a 57% reduction in the risk of progression, albeit with increased toxicity. Multiple treatment options are now available to women with hr+ her2- advanced breast cancer recurring or progressing on earlier nsai therapy, although current clinical trial data suggest more robust clinical efficacy with everolimus plus exemestane. Consideration should be given to the patient's age, functional status, and comorbidities during selection of an endocrine therapy, and use of a proactive everolimus safety management strategy is encouraged. PMID:23443928

  12. Regulation of Neurotrophin-3 and Interleukin-1β and Inhibition of Spinal Glial Activation Contribute to the Analgesic Effect of Electroacupuncture in Chronic Neuropathic Pain States of Rats

    PubMed Central

    Tu, Wenzhan; Wang, Wansheng; Xi, Haiyan; He, Rong; Gao, Liping; Jiang, Songhe

    2015-01-01

    Growing evidence indicates that neurotrophin-3, interleukin-1β, and spinal glia are involved in neuropathic pain derived from dorsal root ganglia to spinal cord. Electroacupuncture is widely accepted to treat chronic pain, but the precise mechanism underlying the analgesic effect of EA has not been fully demonstrated. In this study, the mechanical withdrawal threshold and thermal withdrawal latency were recorded. We used immunofluorescence and western blots methods to investigate the effect of EA on the expression of NT-3 and IL-1β in DRG and spinal cord of CCI rats; we also examined the expression of spinal GFAP and OX-42 in spinal cord. In present study, the MWT and TWL of CCI group rats were lower than those in the Sham CCI group rats, but EA treatment increased the pain thresholds. Furtherly, we found that EA upregulates the expression of NT-3 in DRG and spinal cord of CCI rats, while EA downregulates the expression of IL-1β. Additionally, immunofluorescence exhibited that CCI-induced activation of microglia and astrocytes was inhibited significantly by EA treatment. These results demonstrated that the analgesic effect of EA may be achieved through promoting the neural protection of NT-3 as well as the inhibition of IL-1β production and spinal glial activity. PMID:26161124

  13. Increased Chondroitin Sulfate Proteoglycan Expression in Denervated Brainstem Targets Following Spinal Cord Injury Creates a Barrier to Axonal Regeneration Overcome by Chondroitinase ABC and Neurotrophin-3

    PubMed Central

    Massey, James M.; Amps, Jeremy; Viapiano, Mariano S.; Matthews, Russell. T.; Wagoner, Michelle R.; Whitaker, Christopher M.; Alilain, Warren; Yonkof, Alicia L.; Khalyfa, Abdelnaby; Cooper, Nigel G. F.; Silver, Jerry; Onifer, Stephen M.

    2008-01-01

    Increased chondroitin sulfate proteoglycan (CSPG) expression in the vicinity of a spinal cord injury (SCI) is a primary participant in axonal regeneration failure. However, the presence of similar increases of CSPG expression in denervated synaptic targets well away from the primary lesion and the subsequent impact on regenerating axons attempting to approach deafferented neurons has not been studied. Constitutively expressed CSPGs within the extracellular matrix and perineuronal nets of the adult rat dorsal column nuclei (DCN) were characterized using real-time PCR, western blot analysis and immunohistochemistry. We show for the first time that by 2 days and through 3 weeks following SCI, the levels of NG2, neurocan and brevican associated with reactive glia throughout the DCN were dramatically increased throughout the DCN despite being well beyond areas of trauma-induced blood brain barrier breakdown. Importantly, regenerating axons from adult sensory neurons microtransplanted 2 weeks following SCI between the injury site and the DCN were able to regenerate rapidly within white matter (as shown previously by Davies et al., 1999) but were unable to enter the denervated DCN. Application of chondroitinase ABC or neurotrophin 3-expressing lentivirus in the DCN partially overcame this inhibition. When the treatments were combined, entrance by regenerating axons into the DCN was significantly augmented. These results demonstrate both an additional challenge and potential treatment strategy for successful functional pathway reconstruction after SCI. PMID:17540369

  14. Clinical and genomic analysis of a randomised phase II study evaluating anastrozole and fulvestrant in postmenopausal patients treated for large operable or locally advanced hormone-receptor-positive breast cancer

    PubMed Central

    Quenel-Tueux, Nathalie; Debled, Marc; Rudewicz, Justine; MacGrogan, Gaetan; Pulido, Marina; Mauriac, Louis; Dalenc, Florence; Bachelot, Thomas; Lortal, Barbara; Breton-Callu, Christelle; Madranges, Nicolas; de Lara, Christine Tunon; Fournier, Marion; Bonnefoi, Hervé; Soueidan, Hayssam; Nikolski, Macha; Gros, Audrey; Daly, Catherine; Wood, Henry; Rabbitts, Pamela; Iggo, Richard

    2015-01-01

    Background: The aim of this study was to assess the efficacy of neoadjuvant anastrozole and fulvestrant treatment of large operable or locally advanced hormone-receptor-positive breast cancer not eligible for initial breast-conserving surgery, and to identify genomic changes occurring after treatment. Methods: One hundred and twenty post-menopausal patients were randomised to receive 1 mg anastrozole (61 patients) or 500 mg fulvestrant (59 patients) for 6 months. Genomic DNA copy number profiles were generated for a subgroup of 20 patients before and after treatment. Results: A total of 108 patients were evaluable for efficacy and 118 for toxicity. The objective response rate determined by clinical palpation was 58.9% (95% CI=45.0–71.9) in the anastrozole arm and 53.8% (95% CI=39.5–67.8) in the fulvestrant arm. The breast-conserving surgery rate was 58.9% (95% CI=45.0–71.9) in the anastrozole arm and 50.0% (95% CI=35.8–64.2) in the fulvestrant arm. Pathological responses >50% occurred in 24 patients (42.9%) in the anastrozole arm and 13 (25.0%) in the fulvestrant arm. The Ki-67 score fell after treatment but there was no significant difference between the reduction in the two arms (anastrozole 16.7% (95% CI=13.3–21.0) before, 3.2% (95% CI=1.9–5.5) after, n=43; fulvestrant 17.1% (95%CI=13.1–22.5) before, 3.2% (95% CI=1.8–5.7) after, n=38) or between the reduction in Ki-67 in clinical responders and non-responders. Genomic analysis appeared to show a reduction of clonal diversity following treatment with selection of some clones with simpler copy number profiles. Conclusions: Both anastrozole and fulvestrant were effective and well-tolerated, enabling breast-conserving surgery in over 50% of patients. Clonal changes consistent with clonal selection by the treatment were seen in a subgroup of patients. PMID:26171933

  15. Quality of life with palbociclib plus fulvestrant in previously treated hormone receptor-positive, HER2-negative metastatic breast cancer: patient-reported outcomes from the PALOMA-3 trial

    PubMed Central

    Harbeck, N.; Iyer, S.; Turner, N.; Cristofanilli, M.; Ro, J.; André, F.; Loi, S.; Verma, S.; Iwata, H.; Bhattacharyya, H.; Puyana Theall, K.; Bartlett, C. H.; Loibl, S.

    2016-01-01

    Background In the PALOMA-3 study, palbociclib plus fulvestrant demonstrated improved progression-free survival compared with fulvestrant plus placebo in hormone receptor-positive, HER2− endocrine-resistant metastatic breast cancer (MBC). This analysis compared patient-reported outcomes (PROs) between the two treatment groups. Patients and methods Patients were randomized 2 : 1 to receive palbociclib 125 mg/day orally for 3 weeks followed by 1 week off (n = 347) plus fulvestrant (500 mg i.m. per standard of care) or placebo plus fulvestrant (n = 174). PROs were assessed on day 1 of cycles 1–4 and of every other subsequent cycle starting with cycle 6 using the EORTC QLQ-C30 and its breast cancer module, QLQ-BR23. High scores (range 0–100) could indicate better functioning/quality of life (QoL) or worse symptom severity. Repeated-measures mixed-effect analyses were carried out to compare on-treatment overall scores and changes from baseline between treatment groups while controlling for baseline. Between-group comparisons of time to deterioration in global QoL and pain were made using an unstratified log-rank test and Cox proportional hazards model. Results Questionnaire completion rates were high at baseline and during treatment (from baseline to cycle 14, ≥95.8% in each group completed ≥1 question on the EORTC QLQ-C30). On treatment, estimated overall global QoL scores significantly favored the palbociclib plus fulvestrant group [66.1, 95% confidence interval (CI) 64.5–67.7 versus 63.0, 95% CI 60.6–65.3; P = 0.0313]. Significantly greater improvement from baseline in pain was also observed in this group (−3.3, 95% CI −5.1 to −1.5 versus 2.0, 95% CI −0.6 to 4.6; P = 0.0011). No significant differences were observed for other QLQ-BR23 functioning domains, breast or arm symptoms. Treatment with palbociclib plus fulvestrant significantly delayed deterioration in global QoL (P < 0.025) and pain (P < 0.001) compared with fulvestrant alone. Conclusion

  16. Lettuce glycoside B ameliorates cerebral ischemia reperfusion injury by increasing nerve growth factor and neurotrophin-3 expression of cerebral cortex in rats

    PubMed Central

    Zhan, Heqin; Li, Shengying; Sun, Juan; Liu, Ruili; Yan, Fulin; Niu, Bingxuan; Zhang, Haifang; Wang, Xinyao

    2014-01-01

    Aims: The aim of the study was to investigate the effects of LGB on cerebral ischemia-reperfusion (I/R) injury in rats and the mechanisms of action of LGB. Materials and Methods: The study involved extracting LGB from P. laciniata, exploring affects of LGB on brain ischemia and action mechanism at the molecular level. The cerebral ischemia reperfusion injury of middle cerebral artery occlusion was established. We measured brain histopathology and brain infarct rate to evaluate the effects of LGB on brain ischemia injury. The expressions of nerve growth factor (NGF) and neurotrophin-3 (NT-3) were also measured to investigate the mechanisms of action by the real-time polymerase chain reaction and immunohistochemistry. Statistical analysis: All results were mentioned as mean ± standard deviation. One-way analysis of variance was used to determine statistically significant differences among the groups. Values of P < 0.05 were considered to be statistically significant. Results: Intraperitoneal injection of LGB at the dose of 12, 24, and 48 mg/kg after brain ischemia injury remarkably ameliorated the morphology of neurons and brain infarct rate (P < 0.05, P < 0.01). LGB significantly increased NGF and NT-3 mRNA (messenger RNA) and both protein expression in cerebral cortex at the 24 and 72 h after drug administration (P < 0.05, P < 0.01). Conclusions: LGB has a neuroprotective effect in cerebral I/R injury and this effect might be attributed to its upregulation of NGF and NT-3 expression ability in the brain cortex during the latter phase of brain ischemia. PMID:24550587

  17. Human autoantibodies specific for neurotrophin receptors TrkA, TrkB, and TrkC protect against lethal Trypanosoma cruzi infection in mice.

    PubMed

    Lu, Bo; Alroy, Joseph; Luquetti, Alejandro O; PereiraPerrin, Mercio

    2008-11-01

    Patients with Chagas' disease remain asymptomatic for many years, presumably by keeping the etiological agent Trypanosoma cruzi in check through protective immunity against. Recently, we found that T. cruzi uses TrkA, a receptor tyrosine kinase responsive to neurotrophin nerve growth factor in vertebrate nervous systems, to invade cells. We also found that TrkA, TrkB, and TrkC, but not T. cruzi, are targets of specific autoantibodies present in the sera of patients with chronic Chagas' disease. Here we show that TrkA-, TrkB-, and TrkC-specific autoantibodies isolated from the sera of four individuals with chronic indeterminate (asymptomatic) Chagas' disease potently blocked invasion of Trk-bearing neuronal PC12 cells, neuroglial astrocytes, enteroglial cells, and Schwann cells and Trk-expressing non-neural smooth muscle and dendritic cells. However, these autoantibodies did not inhibit T. cruzi invasion of mutant PC12 cells lacking TrkA or of normal cells lacking Trk receptors, suggesting that autoantibodies interfered with parasite/Trk cross talk to access the intracellular milieu. Passive immunization of susceptible and resistant mouse strains with very small doses of these autoantibodies reduced parasitemia and transferred resistance to an otherwise lethal trypanosome infection. Hence, this exquisitely sensitive and unique regulatory immunity against the host (instead of parasite) could benefit infected individuals by blocking cellular invasion of the obligatory intracellular pathogen, resulting in attenuation of tissue infection and clinical manifestations. Such action is contrary to the horror autotoxicus frequently associated with microbe-related autoimmune responses. PMID:18832578

  18. Combinatorial treatment of tart cherry extract and essential fatty acids reduces cognitive impairments and inflammation in the mu-p75 saporin-induced mouse model of Alzheimer's disease.

    PubMed

    Matchynski, Jessica J; Lowrance, Steven A; Pappas, Colleen; Rossignol, Julien; Puckett, Nicole; Sandstrom, Michael; Dunbar, Gary L

    2013-04-01

    Alzheimer's disease (AD) is a progressive neurodegenerative disorder that affects more than five million Americans and is characterized by a progressive loss of memory, loss of cholinergic neurons in the basal forebrain, formation of amyloid plaques and neurofibrillary tangles, and an increase in oxidative stress. Recent studies indicate that dietary supplements of antioxidants and omega-3 and omega-6 fatty acids may reduce the cognitive deficits in AD patients. The current study tested a combinatorial treatment of antioxidants from tart cherry extract and essential fatty acids from Nordic fish and emu oils for reducing cognitive deficits in the mu-p75 saporin (SAP)-induced mouse model of AD. Mice were given daily gavage treatments of Cerise(®) Total-Body-Rhythm™ (TBR; containing tart cherry extract, Nordic fish oil, and refined emu oil) or vehicle (methylcellulose) for 2 weeks before intracerebroventricular injections of the cholinergic toxin, mu-p75 SAP, or phosphate-buffered saline. The TBR treatments continued for an additional 17 days, when the mice were tested on a battery of cognitive and motor tasks. Results indicate that TBR decreased the SAP-induced cognitive deficits assessed by the object-recognition, place-recognition, and Morris-water-maze tasks. Histological examination of the brain tissue indicated that TBR protected against SAP-induced inflammatory response and loss of cholinergic neurons in the area around the medial septum. These findings indicate that TBR has the potential to serve as an adjunctive treatment which may help reduce the severity of cognitive deficits in disorders involving cholinergic deficits, such as AD. PMID:23566055

  19. Compound danshen tablet ameliorated aβ25-35-induced spatial memory impairment in mice via rescuing imbalance between cytokines and neurotrophins

    PubMed Central

    2014-01-01

    mice by rescuing imbalance between cytokines and neurotrophins. PMID:24422705

  20. Tumor necrosis factor-alpha inhibits stem cell factor-induced proliferation of human bone marrow progenitor cells in vitro. Role of p55 and p75 tumor necrosis factor receptors.

    PubMed Central

    Rusten, L S; Smeland, E B; Jacobsen, F W; Lien, E; Lesslauer, W; Loetscher, H; Dubois, C M; Jacobsen, S E

    1994-01-01

    Stem cell factor (SCF), a key regulator of hematopoiesis, potently synergizes with a number of hematopoietic growth factors. However, little is known about growth factors capable of inhibiting the actions of SCF. TNF-alpha has been shown to act as a bidirectional regulator of myeloid cell proliferation and differentiation. This study was designed to examine interactions between TNF-alpha and SCF. Here, we demonstrate that TNF-alpha potently and directly inhibits SCF-stimulated proliferation of CD34+ hematopoietic progenitor cells. Furthermore, TNF-alpha blocked all colony formation stimulated by SCF in combination with granulocyte colony-stimulating factor (CSF) or CSF-1. The synergistic effect of SCF observed in combination with GM-CSF or IL-3 was also inhibited by TNF-alpha, resulting in colony numbers similar to those obtained in the absence of SCF. These effects of TNF-alpha were mediated through the p55 TNF receptor, whereas little or no inhibition was signaled through the p75 TNF receptor. Finally, TNF-alpha downregulated c-kit cell-surface expression on CD34+ bone marrow cells, and this was predominantly a p55 TNF receptor-mediated event as well. Images PMID:7518828

  1. Production of granulocyte/macrophage-colony-stimulating factor by human natural killer cells. Modulation by the p75 subunit of the interleukin 2 receptor and by the CD2 receptor.

    PubMed

    Levitt, L J; Nagler, A; Lee, F; Abrams, J; Shatsky, M; Thompson, D

    1991-07-01

    Resting natural killer (NK) cells express the p75 chain of the IL-2 receptor (IL-2R beta) and most NK cells express the CD2 (erythrocyte rosette) receptor. The cell adhesion molecule, LFA-3, is a natural co-ligand for CD2. Tac antigen (IL-2R alpha), a p55 IL-2R subunit, can be expressed after NK activation and may play a role in IL-2-induced NK proliferation. Little is known of the molecular mechanisms underlying cytokine production in NK cells. We investigated the roles of IL-2R alpha, IL-2R beta, and CD2/LFA-3 in the molecular regulation of NK cell granulocyte/macrophage-colony-stimulating factor (GM-CSF) production. Enriched populations of peripheral blood NK cells were separated into CD16-positive and CD16-negative fractions by flow cytometry; positively selected cells were greater than 97% positive for CD16 (the FcIII receptor for IgG which is present on almost all NK cells), less than 1% positive for the T cell antigen CD3, and did not demonstrate rearrangement of the T cell receptor beta chain gene by Southern blot. NK cell supernatants were harvested after 3-4 d of incubation with 0-100 U/ml IL-2, or after incubation with anti-CD2 (T11(3] MAb and sheep red blood cells (SRBC are a homologue for LFA-3). Parallel cell aliquots were harvested at 3-16 h for transcriptional run-on assays, S1 nuclease assays, and actinomycin D mRNA t1/2 determinations. IL-2-activated NK supernatants contained large amounts of GM-CSF (178 +/- 35 pg/ml) by ELISA as did supernatants from CD2-activated NK cells (T11(3) MAb + SRBC: 212 +/- 42) vs. less than 20 pg/ml for NK cells incubated alone or with either SRBC or T11(3) MAb alone. Sepharose-linked anti-CD3 MAb did not induce GM-CSF release from NK cells. By S1 analysis, both IL-2 and CD2 stimulation markedly augmented GM-CSF mRNA expression but with very different latencies of onset. IL-2R beta MAb inhibited greater than 85% of GM-CSF release from IL-2-activated NK cells and markedly suppressed IL-2-induced GM-CSF mRNA expression

  2. Current medical treatment of estrogen receptor-positive breast cancer

    PubMed Central

    Lumachi, Franco; Santeufemia, Davide A; Basso, Stefano MM

    2015-01-01

    Approximately 80% of breast cancers (BC) are estrogen receptor (ER)-positive and thus endocrine therapy (ET) should be considered complementary to surgery in the majority of patients. The advantages of oophorectomy, adrenalectomy and hypophysectomy in women with advanced BC have been demonstrated many years ago, and currently ET consist of (1) ovarian function suppression (OFS), usually obtained using gonadotropin-releasing hormone agonists (GnRHa); (2) selective estrogen receptor modulators or down-regulators (SERMs or SERDs); and (3) aromatase inhibitors (AIs), or a combination of two or more drugs. For patients aged less than 50 years and ER+ BC, there is no conclusive evidence that the combination of OFS and SERMs (i.e., tamoxifen) or chemotherapy is superior to OFS alone. Tamoxifen users exhibit a reduced risk of BC, both invasive and in situ, especially during the first 5 years of therapy, and extending the treatment to 10 years further reduced the risk of recurrences. SERDs (i.e., fulvestrant) are especially useful in the neoadjuvant treatment of advanced BC, alone or in combination with either cytotoxic agents or AIs. There are two types of AIs: type I are permanent steroidal inhibitors of aromatase, while type II are reversible nonsteroidal inhibitors. Several studies demonstrated the superiority of the third-generation AIs (i.e., anastrozole and letrozole) compared with tamoxifen, and adjuvant therapy with AIs reduces the recurrence risk especially in patients with advanced BC. Unfortunately, some cancers are or became ET-resistant, and thus other drugs have been suggested in combination with SERMs or AIs, including cyclin-dependent kinase 4/6 inhibitors (palbociclib) and mammalian target of rapamycin (mTOR) inhibitors, such as everolimus. Further studies are required to confirm their real usefulness. PMID:26322178

  3. Somatostatin-receptor positive brain stem glioma visualized by octreoscan.

    PubMed

    Pichler, Robert; Pichler, Josef; Mustafa, Hamdy; Nussbaumer, Karin; Zaunmüller, Thomas; Topakian, Raffi

    2007-06-01

    In diffuse brainstem gliomas often surgical biopsies cannot be obtained. The diagnosis relies upon imaging criteria, first line being MRI. Gliomas generally express somatostatin receptors (SSTR), which might enable receptor imaging. We present the case of a female adolescent with acute onset of hallucinations, dysphagia and diplopia. MRI detected a suggestive large pontine glioma. This lesion presented with marked In-111-pentreotide tracer uptake. SSTR-scan provided information about SSTR-expression, tumour viability and extension. Radiopeptide therapy for selected patients might be discussed. PMID:17627256

  4. Are AMPA receptor positive allosteric modulators potential pharmacotherapeutics for addiction?

    PubMed

    Watterson, Lucas R; Olive, M Foster

    2013-01-01

    Positive allosteric modulators (PAMs) of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors are a diverse class of compounds that increase fast excitatory transmission in the brain. AMPA PAMs have been shown to facilitate long-term potentiation, strengthen communication between various cortical and subcortical regions, and some of these compounds increase the production and release of brain-derived neurotrophic factor (BDNF) in an activity-dependent manner. Through these mechanisms, AMPA PAMs have shown promise as broad spectrum pharmacotherapeutics in preclinical and clinical studies for various neurodegenerative and psychiatric disorders. In recent years, a small collection of preclinical animal studies has also shown that AMPA PAMs may have potential as pharmacotherapeutic adjuncts to extinction-based or cue-exposure therapies for the treatment of drug addiction. The present paper will review this preclinical literature, discuss novel data collected in our laboratory, and recommend future research directions for the possible development of AMPA PAMs as anti-addiction medications. PMID:24380895

  5. Are AMPA Receptor Positive Allosteric Modulators Potential Pharmacotherapeutics for Addiction?

    PubMed Central

    Watterson, Lucas R.; Olive, M. Foster

    2013-01-01

    Positive allosteric modulators (PAMs) of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors are a diverse class of compounds that increase fast excitatory transmission in the brain. AMPA PAMs have been shown to facilitate long-term potentiation, strengthen communication between various cortical and subcortical regions, and some of these compounds increase the production and release of brain-derived neurotrophic factor (BDNF) in an activity-dependent manner. Through these mechanisms, AMPA PAMs have shown promise as broad spectrum pharmacotherapeutics in preclinical and clinical studies for various neurodegenerative and psychiatric disorders. In recent years, a small collection of preclinical animal studies has also shown that AMPA PAMs may have potential as pharmacotherapeutic adjuncts to extinction-based or cue-exposure therapies for the treatment of drug addiction. The present paper will review this preclinical literature, discuss novel data collected in our laboratory, and recommend future research directions for the possible development of AMPA PAMs as anti-addiction medications. PMID:24380895

  6. Differential effects of Th1, monocyte/macrophage and Th2 cytokine mixtures on early gene expression for glial and neural-related molecules in central nervous system mixed glial cell cultures: neurotrophins, growth factors and structural proteins

    PubMed Central

    Lisak, Robert P; Benjamins, Joyce A; Bealmear, Beverly; Nedelkoska, Liljana; Yao, Bin; Land, Susan; Studzinski, Diane

    2007-01-01

    Background In multiple sclerosis, inflammatory cells are found in both active and chronic lesions, and it is increasingly clear that cytokines are involved directly and indirectly in both formation and inhibition of lesions. We propose that cytokine mixtures typical of Th1 or Th2 lymphocytes, or monocyte/macrophages each induce unique molecular changes in glial cells. Methods To examine changes in gene expression that might occur in glial cells exposed to the secreted products of immune cells, we have used gene array analysis to assess the early effects of different cytokine mixtures on mixed CNS glia in culture. We compared the effects of cytokines typical of Th1 and Th2 lymphocytes and monocyte/macrophages (M/M) on CNS glia after 6 hours of treatment. Results In this paper we focus on changes with potential relevance for neuroprotection and axon/glial interactions. Each mixture of cytokines induced a unique pattern of changes in genes for neurotrophins, growth and maturation factors and related receptors; most notably an alternatively spliced form of trkC was markedly downregulated by Th1 and M/M cytokines, while Th2 cytokines upregulated BDNF. Genes for molecules of potential importance in axon/glial interactions, including cell adhesion molecules, connexins, and some molecules traditionally associated with neurons showed significant changes, while no genes for myelin-associated genes were regulated at this early time point. Unexpectedly, changes occurred in several genes for proteins initially associated with retina, cancer or bone development, and not previously reported in glial cells. Conclusion Each of the three cytokine mixtures induced specific changes in gene expression that could be altered by pharmacologic strategies to promote protection of the central nervous system. PMID:18088439

  7. A Hydroxylated Metabolite of Flame-Retardant PBDE-47 Decreases the Survival, Proliferation, and Neuronal Differentiation of Primary Cultured Adult Neural Stem Cells and Interferes with Signaling of ERK5 MAP Kinase and Neurotrophin 3

    PubMed Central

    Xia, Zhengui

    2013-01-01

    Polybrominated diphenyl ethers (PBDEs) are a group of organobromine compounds widely used as flame retardants. PBDE-47 is one of the most prominent PBDE congeners found in human tissues, and it can be transformed into several metabolites, including 6-OH-PBDE-47. Recent studies have shown that PBDE-47 is neurotoxic to animals and possibly humans. However, the basis for the neurotoxicity of PBDEs and their metabolites is unclear. For example, it is not known whether PBDEs affect adult neurogenesis, a process implicated in learning and memory and in olfactory behavior. In this study, we examined the toxicity of PBDEs for primary adult neural stem/progenitor cells (aNSCs) isolated from the subventricular zone (SVZ) of adult mice. We discovered that 6-OH-PBDE-47, but not its parent compound PBDE-47, is cytotoxic for aNCSs using MTS metabolism and cell number as a measure of cytotoxicity. Interestingly, 6-OH-PBDE-47 induced apoptosis at concentrations above 7.5μM inhibited proliferation at 2.5–5μM while suppressing neuronal and oligodendrocyte differentiation at submicromolar concentrations (≤ 1μM). The effect on proliferation was reversed upon removal of 6-OH-PBDE-47 and correlated with selective but reversible inhibition of ERK5 activation by mitogenic growth factors EGF and bFGF. 6-OH-PBDE-47 also inhibited the proneuronal differentiation effect of neurotrophin 3 (NT3) and NT3 activation of ERK5. Together, these data show that 6-OH-PBDE-47 is more toxic than its parent compound for SVZ-derived aNSCs and that it inhibits multiple aspects of adult neurogenesis. Furthermore, inhibition of ERK5 signaling may underlie the adverse effect of 6-OH-PBDE-47 on proliferation and neuronal differentiation. Our data suggest that exposure to PBDE-based flame retardants could cause neurotoxicity in the adult brain by interfering with adult neurogenesis. PMID:23564643

  8. Assessment of non-BDNF neurotrophins and GDNF levels after depression treatment with sertraline and transcranial direct current stimulation in a factorial, randomized, sham-controlled trial (SELECT-TDCS): An exploratory analysis

    PubMed Central

    Brunoni, André R.; Machado-Vieira, Rodrigo; Zarate, Carlos A.; Vieira, Erica L. M.; Valiengo, Leandro; Benseñor, Isabela M.; Lotufo, Paulo A.; Gattaz, Wagner F.; Teixeira, Antonio L.

    2014-01-01

    The neurotrophic hypothesis of depression states that the major depressive episode is associated with lower neurotrophic factors levels, which increase with amelioration of depressive symptoms. However, this hypothesis has not been extended to investigate neurotrophic factors other than the brain-derived neurotrophic factor (BDNF). We therefore explored whether plasma levels of neurotrophins 3 (NT-3) and 4 (NT-4), nerve growth factor (NGF) and glial cell line derived neurotrophic factor (GDNF) changed after antidepressant treatment and correlated with treatment response. Seventy-three patients with moderate-to-severe, antidepressant-free unipolar depression were assigned to a pharmacological (sertraline) and a non-pharmacological (transcranial direct current stimulation, tDCS) intervention in a randomized, 2 × 2, placebo-controlled design. The plasma levels of NT-3, NT-4, NGF and GDNF were determined by enzyme-linked immunosorbent assay before and after a 6-week treatment course and analyzed according to clinical response and allocation group. We found that tDCS and sertraline (separately and combined) produced significant improvement in depressive symptoms. Plasma levels of all neurotrophic factors were similar across groups at baseline and remained significantly unchanged regardless of the intervention and of clinical response. Also, baseline plasma levels were not associated with clinical response. To conclude, in this 6-week placebo-controlled trial, NT-3, NT-4, NGF and GDNF plasma levels did not significantly change with sertraline or tDCS. These data suggest that these neurotrophic factors are not surrogate biomarkers of treatment response or involved in the antidepressant mechanisms of tDCS. PMID:25172025

  9. Phase I/II dose-escalation study of PI3K inhibitors pilaralisib or voxtalisib in combination with letrozole in patients with hormone-receptor-positive and HER2-negative metastatic breast cancer refractory to a non-steroidal aromatase inhibitor.

    PubMed

    Blackwell, Kimberly; Burris, Howard; Gomez, Patricia; Lynn Henry, N; Isakoff, Steven; Campana, Frank; Gao, Lei; Jiang, Jason; Macé, Sandrine; Tolaney, Sara M

    2015-11-01

    This phase I/II dose-escalation study evaluated the efficacy, safety, and pharmacokinetics of pilaralisib (SAR245408), a pan-class I phosphoinositide 3-kinase (PI3K) inhibitor, or voxtalisib (SAR245409), a PI3K and mammalian target of rapamycin inhibitor, in combination with letrozole in hormone-receptor-positive (HR+), human epidermal growth factor receptor 2 (HER2)-negative, non-steroidal aromatase inhibitor-refractory, recurrent or metastatic breast cancer. Maximum tolerated doses (MTDs) were determined using a 3 + 3 design in phase I. Efficacy was evaluated at the MTDs in phase II. Twenty-one patients were enrolled in phase I; MTDs were determined to be pilaralisib tablets 400 mg once daily (QD) or voxtalisib capsules 50 mg twice daily in combination with letrozole tablets 2.5 mg QD. Fifty-one patients were enrolled in phase II; one patient had a partial response in the pilaralisib arm. Rates of progression-free survival at 6 months were 17 and 8 % in the pilaralisib and voxtalisib arms, respectively. The most frequently reported treatment-related grade ≥ 3 adverse events were aspartate aminotransferase increased (5 %) and rash (5 %) in the pilaralisib arm, and alanine aminotransferase increased (11 %) and rash (9 %) in the voxtalisib arm. Pilaralisib and voxtalisib did not interact pharmacokinetically with letrozole. Pilaralisib had a greater pharmacodynamic impact than voxtalisib, as demonstrated by its impact on glucose homeostasis. There was no association between molecular alterations in the PI3K pathway and efficacy. In summary, pilaralisib or voxtalisib, in combination with letrozole, was associated with an acceptable safety profile and limited efficacy in endocrine therapy-resistant HR+ , HER2-negative metastatic breast cancer. PMID:26497877

  10. Prognostic ability of EndoPredict compared to research-based versions of the PAM50 risk of recurrence (ROR) scores in node-positive, estrogen receptor-positive, and HER2-negative breast cancer. A GEICAM/9906 sub-study.

    PubMed

    Martin, Miguel; Brase, Jan C; Ruiz, Amparo; Prat, Aleix; Kronenwett, Ralf; Calvo, Lourdes; Petry, Christoph; Bernard, Philip S; Ruiz-Borrego, Manuel; Weber, Karsten E; Rodriguez, César A; Alvarez, Isabel M; Segui, Miguel A; Perou, Charles M; Casas, Maribel; Carrasco, Eva; Caballero, Rosalía; Rodriguez-Lescure, Alvaro

    2016-02-01

    There are several prognostic multigene-based tests for managing breast cancer (BC), but limited data comparing them in the same cohort. We compared the prognostic performance of the EndoPredict (EP) test (standardized for pathology laboratory) with the research-based PAM50 non-standardized qRT-PCR assay in node-positive estrogen receptor-positive (ER+) and HER2-negative (HER2-) BC patients receiving adjuvant chemotherapy followed by endocrine therapy (ET) in the GEICAM/9906 trial. EP and PAM50 risk of recurrence (ROR) scores [based on subtype (ROR-S) and on subtype and proliferation (ROR-P)] were compared in 536 ER+/HER2- patients. Scores combined with clinical information were evaluated: ROR-T (ROR-S, tumor size), ROR-PT (ROR-P, tumor size), and EPclin (EP, tumor size, nodal status). Patients were assigned to risk-categories according to prespecified cutoffs. Distant metastasis-free survival (MFS) was analyzed by Kaplan-Meier. ROR-S, ROR-P, and EP scores identified a low-risk group with a relative better outcome (10-year MFS: ROR-S 87 %; ROR-P 89 %; EP 93 %). There was no significant difference between tests. Predictors including clinical information showed superior prognostic performance compared to molecular scores alone (10-year MFS, low-risk group: ROR-T 88 %; ROR-PT 92 %; EPclin 100 %). The EPclin-based risk stratification achieved a significantly improved prediction of MFS compared to ROR-T, but not ROR-PT. All signatures added prognostic information to common clinical parameters. EPclin provided independent prognostic information beyond ROR-T and ROR-PT. ROR and EP can reliably predict risk of distant metastasis in node-positive ER+/HER2- BC patients treated with chemotherapy and ET. Addition of clinical parameters into risk scores improves their prognostic ability. PMID:26909792

  11. Imbalance of the Nerve Growth Factor and Its Precursor: Implication in Diabetic Retinopathy

    PubMed Central

    Mohamed, Riyaz; El-Remessy, Azza B

    2015-01-01

    Diabetic retinopathy is the leading cause of blindness in working age in US and worldwide. Neurotrophins including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and neurotrophin-4 (NT-4) are known to be essential for growth, differentiation and survival of neurons in the developing and mature retina. Nevertheless, a growing body of evidence supports an emerging role of neurotrophins in retinal diseases and in particular, diabetic retinopathy. Neurotrophins are initially synthesized in a pro-form and undergo proteolytic cleavage to produce the mature form that activates two distinctive receptors, the tyrosine kinase tropomycin receptor (Trk) and, to lesser extent, the common low affinity p75 neurotrophin receptor (p75NTR). Despite tight glycemic and metabolic control, many diabetic patients continue to experience progressive retinal damage. Understanding the molecular events involved in diabetic retinopathy is extremely important to identify novel therapeutic strategies to halt the disease progression. Diabetes induces imbalance in neurotrophins by increasing its proform, which is associated with upregulation of the p75NTR receptor in the retina. A growing body of evidence supports a link between the imbalance of pro-neurotrophins and early retinal inflammation, neuro-and microvascular degeneration. Therefore, examining changes in the levels of neurotrophins and its receptors might provide a therapeutically beneficial target to combat disease progression in diabetic patients. This commentary aims to highlight the impact of diabetes-impaired balance of neurotrophins and in particular, the NGF and its receptors; TrkA and p75NTR in the pathology of DR. PMID:26807305

  12. Proneurotrophin-3 may induce Sortilin dependent death in inner ear neurons

    PubMed Central

    Tauris, Jacob; Gustafsen, Camilla; Christensen, Erik Ilsø; Jansen, Pernille; Nykjaer, Anders; Nyengaard, Jens R.; Teng, Kenneth K.; Schwarz, Elisabeth; Ovesen, Therese; Madsen, Peder; Petersen, Claus Munck

    2010-01-01

    The precursor of the neurotrophin NGF (proNGF) serves physiological functions distinct from its mature counterpart as it induces neuronal apoptosis through activation of a p75 neurotrophin receptor (p75NTR) and Sortilin death-signalling complex. The neurotrophins BDNF and NT3 provide essential trophic support to auditory neurons. Injury to the neurotrophin secreting cells in the inner ear is followed by irreversible degeneration of spiral ganglion neurons with consequences such as impaired hearing or deafness. Lack of mature neurotrophins may explain the degeneration of spiral ganglion neurons, but another mechanism is possible since unprocessed proNTs released from the injured cells may contribute to the degeneration by induction of apoptosis. Recent studies demonstrate that proBDNF, like proNGF, is a potent inducer of Sortilin:p75NTR mediated apoptosis. In addition, a coincident upregulation of proBDNF and p75NTR has been observed in degenerating spiral ganglion neurons, but the Sortilin expression in the inner ear is unresolved. Here we demonstrate that Sortilin and p75NTR are coexpressed in neurons of the neonatal inner ear. Furthermore, we establish that proNT3 exhibits high affinity binding to Sortilin and has the capacity to enhance cell surface Sortilin:p75NTR complex formation as well as to mediate apoptosis in neurons coexpressing p75NTR and Sortilin. Based on examination of wt and Sortilin deficient mouse embryos, Sortilin does not significantly influence the developmental selection of spiral ganglion neurons. However, our results suggest that proNT3 and proBDNF may play important roles in the response to noise-induced injuries or ototoxic damage via the Sortilin:p75NTR death-signalling complex. PMID:21261755

  13. Ubiquitin-specific Protease 36 (USP36) Controls Neuronal Precursor Cell-expressed Developmentally Down-regulated 4-2 (Nedd4-2) Actions over the Neurotrophin Receptor TrkA and Potassium Voltage-gated Channels 7.2/3 (Kv7.2/3).

    PubMed

    Anta, Begoña; Martín-Rodríguez, Carlos; Gomis-Perez, Carolina; Calvo, Laura; López-Benito, Saray; Calderón-García, Andrés A; Vicente-García, Cristina; Villarroel, Álvaro; Arévalo, Juan C

    2016-09-01

    Ubiquitination of the TrkA neurotrophin receptor in response to NGF is critical in the regulation of TrkA activation and functions. TrkA is ubiquitinated, among other E3 ubiquitin ligases, by Nedd4-2. To understand mechanistically how TrkA ubiquitination is regulated, we performed a siRNA screening to identify deubiquitinating enzymes and found that USP36 acts as an important regulator of TrkA activation kinetics and ubiquitination. However, USP36 action on TrkA was indirect because it does not deubiquitinate TrkA. Instead, USP36 binds to Nedd4-2 and regulates the association of TrkA and Nedd4-2. In addition, depletion of USP36 increases TrkA·Nedd4-2 complex formation, whereas USP36 expression disrupts the complex, resulting in an enhancement or impairment of Nedd4-2-dependent TrkA ubiquitination, respectively. Moreover, USP36 depletion leads to enhanced total and surface TrkA expression that results in increased NGF-mediated TrkA activation and signaling that augments PC12 cell differentiation. USP36 actions extend beyond TrkA because the presence of USP36 interferes with Nedd4-2-dependent Kv7.2/3 channel regulation. Our results demonstrate that USP36 binds to and regulates the actions of Nedd4-2 over different substrates affecting their expression and functions. PMID:27445338

  14. Ly49Q, an ITIM-bearing NK receptor, positively regulates osteoclast differentiation

    SciTech Connect

    Hayashi, Mikihito; Nakashima, Tomoki; Kodama, Tatsuhiko; Makrigiannis, Andrew P.; Toyama-Sorimachi, Noriko; Takayanagi, Hiroshi

    2010-03-12

    Osteoclasts, multinucleated cells that resorb bone, play a key role in bone remodeling. Although immunoreceptor tyrosine-based activation motif (ITAM)-mediated signaling is critical for osteoclast differentiation, the significance of immunoreceptor tyrosine-based inhibitory motif (ITIM) has not been well understood. Here we report the function of Ly49Q, an Ly49 family member possessing an ITIM motif, in osteoclastogenesis. Ly49Q is selectively induced by receptor activator of nuclear factor-{kappa}B (NF-{kappa}B) ligand (RANKL) stimulation in bone marrow-derived monocyte/macrophage precursor cells (BMMs) among the Ly49 family of NK receptors. The knockdown of Ly49Q resulted in a significant reduction in the RANKL-induced formation of tartrate-resistance acid phosphatase (TRAP)-positive multinucleated cells, accompanied by a decreased expression of osteoclast-specific genes such as Nfatc1, Tm7sf4, Oscar, Ctsk, and Acp5. Osteoclastogenesis was also significantly impaired in Ly49Q-deficient cells in vitro. The inhibitory effect of Ly49Q-deficiency may be explained by the finding that Ly49Q competed for the association of Src-homology domain-2 phosphatase-1 (SHP-1) with paired immunoglobulin-like receptor-B (PIR-B), an ITIM-bearing receptor which negatively regulates osteoclast differentiation. Unexpectedly, Ly49Q deficiency did not lead to impaired osteoclast formation in vivo, suggesting the existence of a compensatory mechanism. This study provides an example in which an ITIM-bearing receptor functions as a positive regulator of osteoclast differentiation.

  15. CXCR4 receptor positive spheroid forming cells are responsible for tumor invasion in vitro.

    PubMed

    Krohn, Alexander; Song, Yao-Hua; Muehlberg, Fabian; Droll, Lilly; Beckmann, Christoph; Alt, Eckhard

    2009-07-18

    Stem cells have been found to be involved in breast cancer growth, but the specific contribution of cancer stem cells in tumor biology, including metastasis, is still uncertain. We found that murine breast cancer cell lines 4T1, 4TO7, 167Farn and 67NR contains cancer stem cells defined by CXCR4 expression and their capability of forming spheroids in suspension culture. Importantly, we showed that CXCR4 expression is essential for tumor invasiveness because both CXCR4 neutralizing antibody and shRNA knockdown of the CXCR4 receptor significantly reduced tumor cell invasion. PMID:19286309

  16. Reproductive factors and risk of hormone receptor positive and negative breast cancer: a cohort study

    PubMed Central

    2013-01-01

    Background The association of reproductive factors with hormone receptor (HR)-negative breast tumors remains uncertain. Methods Within the EPIC cohort, Cox proportional hazards models were used to describe the relationships of reproductive factors (menarcheal age, time between menarche and first pregnancy, parity, number of children, age at first and last pregnancies, time since last full-term childbirth, breastfeeding, age at menopause, ever having an abortion and use of oral contraceptives [OC]) with risk of ER-PR- (n = 998) and ER+PR+ (n = 3,567) breast tumors. Results A later first full-term childbirth was associated with increased risk of ER+PR+ tumors but not with risk of ER-PR- tumors (≥35 vs. ≤19 years HR: 1.47 [95% CI 1.15-1.88] ptrend < 0.001 for ER+PR+ tumors; ≥35 vs. ≤19 years HR: 0.93 [95% CI 0.53-1.65] ptrend = 0.96 for ER-PR- tumors; P het = 0.03). The risk associations of menarcheal age, and time period between menarche and first full-term childbirth with ER-PR-tumors were in the similar direction with risk of ER+PR+ tumors (phet = 0.50), although weaker in magnitude and statistically only borderline significant. Other parity related factors such as ever a full-term birth, number of births, age- and time since last birth were associated only with ER+PR+ malignancies, however no statistical heterogeneity between breast cancer subtypes was observed. Breastfeeding and OC use were generally not associated with breast cancer subtype risk. Conclusion Our study provides possible evidence that age at menarche, and time between menarche and first full-term childbirth may be associated with the etiology of both HR-negative and HR-positive malignancies, although the associations with HR-negative breast cancer were only borderline significant. PMID:24321460

  17. Size controlled protein nanoemulsions for active targeting of folate receptor positive cells.

    PubMed

    Loureiro, Ana; Nogueira, Eugénia; Azoia, Nuno G; Sárria, Marisa P; Abreu, Ana S; Shimanovich, Ulyana; Rollett, Alexandra; Härmark, Johan; Hebert, Hans; Guebitz, Georg; Bernardes, Gonçalo J L; Preto, Ana; Gomes, Andreia C; Cavaco-Paulo, Artur

    2015-11-01

    Bovine serum albumin (BSA) nanoemulsions were produced by high pressure homogenization with a tri-block copolymer (Poloxamer 407), which presents a central hydrophobic chain of polyoxypropylene (PPO) and two identical lateral hydrophilic chains of polyethylene glycol (PEG). We observed a linear correlation between tri-block copolymer concentration and size - the use of 5mg/mL of Poloxamer 407 yields nanoemulsions smaller than 100nm. Molecular dynamics and fluorescent tagging of the tri-block copolymer highlight their mechanistic role on the size of emulsions. This novel method enables the fabrication of highly stable albumin emulsions in the nano-size range, highly desirable for controlled drug delivery. Folic Acid (FA)-tagged protein nanoemulsions were shown to promote specific folate receptor (FR)-mediated targeting in FR positive cells. The novel strategy presented here enables the construction of size controlled, functionalized protein-based nanoemulsions with excellent characteristics for active targeting in cancer therapy. PMID:26241920

  18. Recombinant epoetins do not stimulate tumor growth in erythropoietin receptor-positive breast carcinoma models.

    PubMed

    LaMontagne, Kenneth R; Butler, Jeannene; Marshall, Deborah J; Tullai, Jennifer; Gechtman, Ze'ev; Hall, Chassidy; Meshaw, Alan; Farrell, Francis X

    2006-02-01

    We investigated the significance of erythropoietin receptor (EPOR) expression following treatment with recombinant human erythropoietin (rHuEPO; epoetin alpha) and the effect of recombinant epoetins (epoetin alpha, epoetin beta, and darbepoetin alpha) alone or in combination with anticancer therapy on tumor growth in two well-established preclinical models of breast carcinoma (MDA-MB-231 and MCF-7 cell lines). Expression and localization of EPOR under hypoxic and normoxic conditions in MDA-MB-231 and MCF-7 cells were evaluated by immunoblotting, flow cytometry, and immunohistochemistry. EPOR binding was evaluated using [125I]rHuEPO. Proliferation, migration, and signaling in MDA-MB-231 and MCF-7 cells following treatment with rHuEPO were evaluated. Tumor growth was assessed following administration of recombinant epoetins alone and in combination with paclitaxel (anticancer therapy) in orthotopically implanted MDA-MB-231 and MCF-7 breast carcinoma xenograft models in athymic mice. EPOR expression was detected in both tumor cell lines. EPOR localization was found to be exclusively cytosolic and no specific [125I]rHuEPO binding was observed. There was no stimulated migration, proliferation, or activation of mitogen-activated protein kinase and AKT following rHuEPO treatment. In mice, treatment with recombinant epoetins alone and in combination with paclitaxel resulted in equivalent tumor burdens compared with vehicle-treated controls. Results from our study suggest that although EPOR expression was observed in two well-established breast carcinoma cell lines, it was localized to a cytosolic distribution and did not transduce a signaling cascade in tumors that leads to tumor growth. The addition of recombinant epoetins to paclitaxel did not affect the outcome of paclitaxel therapy in breast carcinoma xenograft models. These results show that recombinant epoetins do not evoke a physiologic response on EPOR-bearing tumor cells as assessed by numerous variables, including growth, migration, and cytotoxic challenge in preclinical in vivo tumor models. PMID:16505108

  19. Phospholipase A2 Receptor-Positive Idiopathic Membranous Glomerulonephritis with Onset at 95 Years: Case Report

    PubMed Central

    Kubota, Keiichi; Hoshino, Junichi; Ueno, Toshiharu; Mise, Koki; Hazue, Ryo; Sekine, Akinari; Yabuuchi, Junko; Yamanouchi, Masayuki; Suwabe, Tatsuya; Kikuchi, Koichi; Sumida, Keiichi; Hayami, Noriko; Sawa, Naoki; Takaichi, Kenmei; Fujii, Takeshi; Ohashi, Kenichi; Akiyama, Shinichi; Maruyama, Shoichi; Ubara, Yoshifumi

    2016-01-01

    A 95-year-old woman was admitted to our hospital for evaluation of bilateral lower-limb edema persisting for 3 months. Serum creatinine was 1.55 mg/dl, and urinary protein excretion was 9.1 g/day. Renal biopsy revealed stage 1 membranous glomerulonephritis (MGN) with immunoglobulin G4-dominant staining. This patient did not have any underlying disease such as infection with hepatitis B or C virus or malignancy, and anti-phospholipase A2 receptor (PLA2R) antibody was detected in the serum. Accordingly, idiopathic MGN was diagnosed. Corticosteroid therapy was avoided, but hemodialysis was required to treat generalized edema. The patient is currently doing well. This is the oldest reported case of idiopathic MGN with positivity for anti-PLA2R antibody. PMID:27390744

  20. Prognostic and Predictive Biomarkers of Endocrine Responsiveness for Estrogen Receptor Positive Breast Cancer.

    PubMed

    Ma, Cynthia X; Bose, Ron; Ellis, Matthew J

    2016-01-01

    The estrogen-dependent nature of breast cancer is the fundamental basis for endocrine therapy. The presence of estrogen receptor (ER), the therapeutic target of endocrine therapy, is a prerequisite for this therapeutic approach. However, estrogen-independent growth often exists de novo at diagnosis or develops during the course of endocrine therapy. Therefore ER alone is insufficient in predicting endocrine therapy efficacy. Several RNA-based multigene assays are now available in clinical practice to assess distant recurrence risk, with majority of these assays evaluated in patients treated with 5 years of adjuvant endocrine therapy. While MammaPrint and Oncotype Dx are most predictive of recurrence risk within the first 5 years of diagnosis, Prosigna, Breast Cancer Index (BCI), and EndoPredict Clin have also demonstrated utility in predicting late recurrence. In addition, PAM50, or Prosigna, provides further biological insights by classifying breast cancers into intrinsic molecular subtypes. Additional strategies are under investigation in prospective clinical trials to differentiate endocrine sensitive and resistant tumors and include on-treatment Ki-67 and Preoperative Endocrine Prognostic Index (PEPI) score in the setting of neoadjuvant endocrine therapy. These biomarkers have become important tools in clinical practice for the identification of low risk patients for whom chemotherapy could be avoided. However, there is much work ahead toward the development of a molecular classification that informs the biology and novel therapeutic targets in high-risk disease as chemotherapy has only modest benefit in this population. The recognition of somatic mutations and their relationship to endocrine therapy responsiveness opens important opportunities toward this goal. PMID:26987533

  1. Targeting Sindbis virus-based vectors to Fc receptor-positive cell types

    SciTech Connect

    Klimstra, William B.; Williams, Jacqueline C.; Ryman, Kate D.; Heidner, Hans W. . E-mail: hans.heidner@utsa.edu

    2005-07-20

    Some viruses display enhanced infection for Fc receptor (FcR)-positive cell types when complexed with virus-specific immunoglobulin (Ig). This process has been termed antibody-dependent enhancement of viral infection (ADE). We reasoned that the mechanism of ADE could be exploited and adapted to target alphavirus-based vectors to FcR-positive cell types. Towards this goal, recombinant Sindbis viruses were constructed that express 1 to 4 immunoglobulin-binding domains of protein L (PpL) as N-terminal extensions of the E2 glycoprotein. PpL is a bacterial protein that binds the variable region of antibody kappa light chains from a range of mammalian species. The recombinant viruses incorporated PpL/E2 fusion proteins into the virion structure and recapitulated the species-specific Ig-binding phenotypes of native PpL. Virions reacted with non-immune serum or purified IgG displayed enhanced binding and ADE for several species-matched FcR-positive murine and human cell lines. ADE required virus expression of a functional PpL Ig-binding domain, and appeared to be Fc{gamma}R-mediated. Specifically, ADE did not occur with Fc{gamma}R-negative cells, did not require active complement proteins, and did not occur on Fc{gamma}R-positive murine cell lines when virions were bound by murine IgG-derived F(ab'){sub 2} fragments.

  2. Lanreotide-conjugated PEG-DSPE micelles: an efficient nanocarrier targeting to somatostatin receptor positive tumors.

    PubMed

    Zheng, Nan; Dai, Wenbing; Zhang, Hua; Wang, Xueqing; Wang, Jiancheng; Zhang, Xuan; Wang, Kun; Li, Jian; Zhang, Qiang

    2015-01-01

    Lanreotide is an octapeptide analog of endogenous somatostatin, specifically binding with tumors over-express somatostatin receptor 2 (SSTR2). In this study, we conjugated lanreotide to 1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (poly-(ethylene glycol))-2000] (PEG-DSPE), constructed active targeted micelles (lanreotide-PM), characterized their in vitro and in vivo targeting effect, and explored the receptor mediated transportion. The uptake of lanreotide-PM was found to be related to the expression level of SSTR2 in different cell lines and the competitive inhibition phenomenon indicated that the cellular uptake of lanreotide-PM was via a receptor meditated mechanism. In vivo, more lanreotide-PM accumulated in SSTR2 high expression tumor xenografts, endocytosed by the tumor cells, induced more apoptosis of tumor cells, and suppressed tumor growth efficiently. In conclusion, lanreotide-modified micelles containing antitumor drugs provide a promising strategy for the treatment of SSTR-expressing tumors. PMID:25366085

  3. Aromatase Expression Increases the Survival and Malignancy of Estrogen Receptor Positive Breast Cancer Cells

    PubMed Central

    Bandyopadhyay, Abhik; Kirma, Nameer B.; Tekmal, Rajeshwar R.; Wang, Shui; Sun, Lu-Zhe

    2015-01-01

    In postmenopausal women, local estrogen produced by adipose stromal cells in the breast is believed to support estrogen receptor alpha (ERα) positive breast cancer cell survival and growth. This raises the question of how the ERα positive metastatic breast cancer cells survive after they enter blood and lymph circulation, where estrogen level is very low in postmenopausal women. In this study, we show that the aromatase expression increased when ERα positive breast cancer cells were cultured in suspension. Furthermore, treatment with the aromatase substrate, testosterone, inhibited suspension culture-induced apoptosis whereas an aromatase inhibitor attenuated the effect of testosterone suggesting that suspended circulating ERα positive breast cancer cells may up-regulate intracrine estrogen activity for survival. Consistent with this notion, a moderate level of ectopic aromatase expression rendered a non-tumorigenic ERα positive breast cancer cell line not only tumorigenic but also metastatic in female nude mice without exogenous estrogen supplementation. The increased malignant phenotype was confirmed to be due to aromatase expression as the growth of orthotopic tumors regressed with systemic administration of an aromatase inhibitor. Thus, our study provides experimental evidence that aromatase plays an important role in the survival of metastatic ERα breast cancer cells by suppressing anoikis. PMID:25837259

  4. TOP2A RNA Expression and Recurrence in Estrogen Receptor-Positive Breast Cancer

    PubMed Central

    Sparano, Joseph A.; Goldstein, Lori J.; Davidson, Nancy E.; Sledge, George W.; Gray, Robert

    2016-01-01

    The purpose of this study is to evaluate the relationship between TOP2A RNA expression and recurrence in patients with operable estrogen receptor (ER) positive breast cancer. We evaluated TOP2A expression in a pooled analysis of 4 independent data sets with gene expression data including 752 patients with early stage, ER-positive, HER2-negative breast cancer, most of whom received either no adjuvant therapy or endocrine therapy without chemotherapy. We also used an algorithm to simulate the Oncotype DX Recurrence Score (simRS) and the proliferation component of the Recurrence Score (simPS). Results are expressed as the hazard ratio (HR) for estimates of the effect of a one standard deviation increase in the value of the log gene expression (x + 1SD vs. x) as a continuous function. TOP2A expression was significantly associated with recurrence (HR 1.56, p<0.0001), and after adjustment for simRS (HR 1.26, p=0.003). TOP2A correlated somewhat with simRS (0.45), but more strongly with simPS (0.69). For those with an intermediate simRS, high TOP2A expression (above the median) was associated with significantly higher relapse rates at five years (HR 1.82, p=0.007). TOP2A expression provides prognostic information in patients with ER-positive, HER2-negative breast cancer, a population known to have low incidence of TOP2A gene alterations. These findings confirm prior reports indicating that TOP2A expression provides prognostic information in ER-positive breast cancer. TOP2A expression may also be useful for identifying those with an intermediate RS who are more likely to relapse, although additional validation in datasets including measured rather than simulated RS will be required. PMID:22706628

  5. In vitro evaluation of actively targetable superparamagnetic nanoparticles to the folate receptor positive cancer cells.

    PubMed

    Nasiri, Rozita; Hamzehalipour Almaki, Javad; Idris, Ani Binti; Abdul Majid, Fadzilah Adibah; Nasiri, Mahtab; Salouti, Mojtaba; Irfan, Muhammad; Amini, Neda; Marvibaigi, Mohsen

    2016-12-01

    Engineering of a physiologically compatible, stable and targetable SPIONs-CA-FA formulation was reported. Initially fabricated superparamagnetic iron oxide nanoparticles (SPIONs) were coated with citric acid (CA) to hamper agglomeration as well as to ameliorate biocompatibility. Folic acid (FA) as a targeting agent was then conjugated to the citric acid coated SPIONs (SPIONs-CA) for targeting the specific receptors expressed on the FAR+ cancer cells. Physiochemical characterizations were then performed to assure required properties like stability, size, phase purity, surface morphology, chemical integrity and magnetic properties. In vitro evaluations (MTT assay) were performed on HeLa, HSF 1184, MDA-MB-468 and MDA-MB-231cell lines to ensure the biocompatibility of SPIONs-CA-FA. There were no morphological changes and lysis in contact with erythrocytes recorded for SPIONs-CA-FA and SPIONs-CA. High level of SPIONs-CA-FA binding to FAR+ cell lines was assured via qualitative and quantitative in vitro binding studies. Hence, SPIONs-CA-FA was introduced as a promising tool for biomedical applications like magnetic hyperthermia and drug delivery. The in vitro findings presented in this study need to be compared with those of in vivo studies. PMID:27612812

  6. Body Mass Index is Associated with Gene Methylation in Estrogen Receptor-Positive Breast Tumors

    PubMed Central

    Hair, Brionna Y.; Troester, Melissa A.; Edmiston, Sharon N.; Parrish, Eloise A.; Robinson, Whitney R.; Wu, Michael C.; Olshan, Andrew F.; Swift-Scanlan, Theresa; Conway, Kathleen

    2015-01-01

    Background Although obesity is associated with breast cancer incidence and prognosis, the underlying mechanisms are poorly understood. Identification of obesity-associated epigenetic changes in breast tissue may advance mechanistic understanding of breast cancer initiation and progression. The goal of this study, therefore, was to investigate associations between obesity and gene methylation in breast tumors. Methods Using the Illumina GoldenGate Cancer I Panel, we estimated the association between body mass index (BMI) and gene methylation in 345 breast tumor samples from Phase I of the Carolina Breast Cancer Study, a population based case-control study. Multivariable linear regression was used to identify sites that were differentially methylated by BMI. Stratification by tumor estrogen receptor status was also conducted. Results In the majority of the 935 probes analyzed (87%), the average beta value increased with obesity (BMI ≥ 30). Obesity was significantly associated with differential methylation (false discovery rate q-value < 0.05) in just 2 gene loci in breast tumor tissue overall and in 21 loci among estrogen receptor (ER)-positive tumors. Obesity was associated with methylation of genes that function in immune response, cell growth, and DNA repair. Conclusions Obesity is associated with altered methylation overall, and with hypermethylation among ER-positive tumors in particular, suggesting that obesity may influence the methylation of genes with known relevance to cancer. Some of these differences in methylation by obese status may influences levels of gene expression within breast cells. Impact If our results are validated, obesity-associated methylation sites could serve as targets for prevention and treatment research. PMID:25583948

  7. Oestrogen receptor positive breast cancer metastasis to bone: inhibition by targeting the bone microenvironment in vivo.

    PubMed

    Holen, I; Walker, M; Nutter, F; Fowles, A; Evans, C A; Eaton, C L; Ottewell, P D

    2016-03-01

    Clinical trials have shown that adjuvant Zoledronic acid (ZOL) reduces the development of bone metastases irrespective of ER status. However, post-menopausal patients show anti-tumour benefit with ZOL whereas pre-menopausal patients do not. Here we have developed in vivo models of spontaneous ER+ve breast cancer metastasis to bone and investigated the effects of ZOL and oestrogen on tumour cell dissemination and growth. ER+ve (MCF7, T47D) or ER-ve (MDA-MB-231) cells were administered by inter-mammary or inter-cardiac injection into female nude mice ± estradiol. Mice were administered saline or 100 μg/kg ZOL weekly. Tumour growth, dissemination of tumour cells in blood, bone and bone turnover were monitored by luciferase imaging, histology, flow cytometry, two-photon microscopy, micro-CT and TRAP/P1NP ELISA. Estradiol induced metastasis of ER+ve cells to bone in 80-100 % of animals whereas bone metastases from ER-ve cells were unaffected. Administration of ZOL had no effect on tumour growth in the fat pad but significantly inhibited dissemination of ER+ve tumour cells to bone and frequency of bone metastasis. Estradiol and ZOL increased bone volume via different mechanisms: Estradiol increased activity of bone forming osteoblasts whereas administration of ZOL to estradiol supplemented mice decreased osteoclast activity and returned osteoblast activity to levels comparable to that of saline treated mice. ER-ve cells require increased osteoclast activity to grow in bone whereas ER+ve cells do not. Zol does not affect ER+ve tumour growth in soft tissue, however, inhibition of bone turnover by ZOL reduced dissemination and growth of ER+ve breast cancer cells in bone. PMID:26585891

  8. Phospholipase A2 receptor positive membranous nephropathy long after living donor kidney transplantation between identical twins.

    PubMed

    Saito, Hisako; Hamasaki, Yoshifumi; Tojo, Akihiro; Shintani, Yukako; Shimizu, Akira; Nangaku, Masaomi

    2015-07-01

    Although membranous nephropathy (MN) is a commonly observed cause of post-transplant glomerulonephritis, distinguishing de novo from recurrent MN in kidney allograft is often difficult. Phospholipase A2 receptor (PLA2R) staining is useful for diagnosing recurrent MN in allografts similarly to idiopathic MN in native kidney. No specific treatment strategy has been established for MN, especially when accompanied with HCV infection in kidney transplant recipients. This report describes a 66-year-old man who was diagnosed as having PLA2R positive membranous nephropathy accompanied with already-known IgA nephropathy and HCV infection 26 years after kidney transplantation conducted between identical twins. PLA2R was detected along capillary loops, implying that this patient is affected by the same pathogenic mechanism as idiopathic MN, not secondary MN associated with other disorders such as HCV infection. The patient successfully achieved clinical remission after steroid therapy. PMID:26031599

  9. 11q13 is a Susceptibility Locus for Hormone Receptor Positive Breast Cancer†

    PubMed Central

    Lambrechts, Diether; Truong, Therese; Justenhoven, Christina; Humphreys, Manjeet K.; Wang, Jean; Hopper, John L.; Dite, Gillian S.; Apicella, Carmel; Southey, Melissa C.; Schmidt, Marjanka K.; Broeks, Annegien; Cornelissen, Sten; van Hien, Richard; Sawyer, Elinor; Tomlinson, Ian; Kerin, Michael; Miller, Nicola; Milne, Roger L.; Zamora, M. Pilar; Arias Pérez, José Ignacio; Benítez, Javier; Hamann, Ute; Ko, Yon-Dschun; Brüning, Thomas; Chang-Claude, Jenny; Eilber, Ursel; Hein, Rebecca; Nickels, Stefan; Flesch-Janys, Dieter; Wang-Gohrke, Shan; John, Esther M.; Miron, Alexander; Winqvist, Robert; Pylkäs, Katri; Jukkola-Vuorinen, Arja; Grip, Mervi; Chenevix-Trench, Georgia; Beesley, Jonathan; Chen, Xiaoqing; Menegaux, Florence; Cordina-Duverger, Emilie; Shen, Chen-Yang; Yu, Jyh-Cherng; Wu, Pei-Ei; Hou, Ming-Feng; Andrulis, Irene L.; Selander, Teresa; Glendon, Gord; Mulligan, Anna Marie; Anton-Culver, Hoda; Ziogas, Argyrios; Muir, Kenneth R.; Lophatananon, Artitaya; Rattanamongkongul, Suthee; Puttawibul, Puttisak; Jones, Michael; Orr, Nicholas; Ashworth, Alan; Swerdlow, Anthony; Severi, Gianluca; Baglietto, Laura; Giles, Graham; Southey, Melissa; Marmé, Federik; Schneeweiss, Andreas; Sohn, Christof; Burwinkel, Barbara; Yesilyurt, Betul T.; Neven, Patrick; Paridaens, Robert; Wildiers, Hans; Brenner, Hermann; Müller, Heiko; Arndt, Volker; Stegmaier, Christa; Meindl, Alfons; Schott, Sarah; Bartram, Claus R.; Schmutzler, Rita K.; Cox, Angela; Brock, Ian W.; Elliott, Graeme; Cross, Simon S.; Fasching, Peter A.; Schulz-Wendtland, Ruediger; Ekici, Arif B.; Beckmann, Matthias W.; Fletcher, Olivia; Johnson, Nichola; Silva, Isabel dos Santos; Peto, Julian; Nevanlinna, Heli; Muranen, Taru A.; Aittomäki, Kristiina; Blomqvist, Carl; Dörk, Thilo; Schürmann, Peter; Bremer, Michael; Hillemanns, Peter; Bogdanova, Natalia V.; Antonenkova, Natalia N.; Rogov, Yuri I.; Karstens, Johann H.; Khusnutdinova, Elza; Bermisheva, Marina; Prokofieva, Darya; Gancev, Shamil; Jakubowska, Anna; Lubinski, Jan; Jaworska, Katarzyna; Durda, Katarzyna; Nordestgaard, Børge G.; Bojesen, Stig E.; Lanng, Charlotte; Mannermaa, Arto; Kataja, Vesa; Kosma, Veli-Matti; Hartikainen, Jaana M.; Radice, Paolo; Peterlongo, Paolo; Manoukian, Siranoush; Bernard, Loris; Couch, Fergus J.; Olson, Janet E.; Wang, Xianshu; Fredericksen, Zachary; Alnæs, Grethe Grenaker; Kristensen, Vessela; Børresen-Dale, Anne-Lise; Devilee, Peter; Tollenaar, Robert A.E.M.; Seynaeve, Caroline M.; Hooning, Maartje J.; García-Closas, Montserrat; Chanock, Stephen J.; Lissowska, Jolanta; Sherman, Mark E.; Hall, Per; Liu, Jianjun; Czene, Kamila; Kang, Daehee; Yoo, Keun-Young; Noh, Dong-Young; Lindblom, Annika; Margolin, Sara; Dunning, Alison M.; Pharoah, Paul D.P.; Easton, Douglas F.; Guénel, Pascal; Brauch, Hiltrud

    2012-01-01

    A recent two-stage genome-wide association study (GWAS) identified five novel breast cancer susceptibility loci on chromosomes 9, 10 and 11. To provide more reliable estimates of the relative risk associated with these loci and investigate possible heterogeneity by subtype of breast cancer, we genotyped the variants rs2380205, rs1011970, rs704010, rs614367, rs10995190 in 39 studies from the Breast Cancer Association Consortium (BCAC), involving 49,608 cases and 48,772 controls of predominantly European ancestry. Four of the variants showed clear evidence of association (P ≤ 3 × 10−9) and weak evidence was observed for rs2380205 (P = 0.06). The strongest evidence was obtained for rs614367, located on 11q13 (per-allele odds ratio 1.21, P = 4 × 10−39). The association for rs614367 was specific to estrogen receptor (ER)-positive disease and strongest for ER plus progesterone receptor (PR)-positive breast cancer, whereas the associations for the other three loci did not differ by tumor subtype. PMID:22461340

  10. Selective activity of deguelin identifies therapeutic targets for androgen receptor-positive breast cancer.

    PubMed

    Robles, Andrew J; Cai, Shengxin; Cichewicz, Robert H; Mooberry, Susan L

    2016-06-01

    Triple-negative breast cancers (TNBC) are aggressive malignancies with no effective targeted therapies. Recent gene expression profiling of these heterogeneous cancers and the classification of cell line models now allows for the identification of compounds with selective activities against molecular subtypes of TNBC. The natural product deguelin was found to have selective activity against MDA-MB-453 and SUM-185PE cell lines, which both model the luminal androgen receptor (LAR) subtype of TNBC. Deguelin potently inhibited proliferation of these cells with GI50 values of 30 and 61 nM, in MDA-MB-453 and SUM-185PE cells, respectively. Deguelin had exceptionally high selectivity, 197 to 566-fold, for these cell lines compared to cell lines representing other TNBC subtypes. Deguelin's mechanisms of action were investigated to determine how it produced these potent and selective effects. Our results show that deguelin has dual activities, inhibiting PI3K/Akt/mTOR signaling, and decreasing androgen receptor levels and nuclear localization. Based on these data, we hypothesized that the combination of the mTOR inhibitor rapamycin and the antiandrogen enzalutamide would have efficacy in LAR models. Rapamycin and enzalutamide showed additive effects in MDA-MB-453 cells, and both drugs had potent antitumor efficacy in a LAR xenograft model. These results suggest that the combination of antiandrogens and mTOR inhibitors might be an effective strategy for the treatment of androgen receptor-expressing TNBC. PMID:27255535

  11. Lectin-based Isolation and Culture of Mouse Embryonic Motoneurons

    PubMed Central

    Conrad, Rebecca; Jablonka, Sibylle; Sczepan, Teresa; Sendtner, Michael; Wiese, Stefan; Klausmeyer, Alice

    2011-01-01

    Spinal motoneurons develop towards postmitotic stages through early embryonic nervous system development and subsequently grow out dendrites and axons. Neuroepithelial cells of the neural tube that express Nkx6.1 are the unique precursor cells for spinal motoneurons1. Though postmitotic motoneurons move towards their final position and organize themselves into columns along the spinal tract2,3. More than 90% of all these differentiated and positioned motoneurons express the transcription factors Islet 1/2. They innervate the muscles of the limbs as well as those of the body and the inner organs. Among others, motoneurons typically express the high affinity receptors for brain derived neurotrophic factor (BDNF) and Neurotrophin-3 (NT-3), the tropomyosin-related kinase B and C (TrkB, TrkC). They do not express the tropomyosin-related kinase A (TrkA)4. Beside the two high affinity receptors, motoneurons do express the low affinity neurotrophin receptor p75NTR. The p75NTR can bind all neurotrophins with similar but lower affinity to all neurotrophins than the high affinity receptors would bind the mature neurotrophins. Within the embryonic spinal cord, the p75NTR is exclusively expressed by the spinal motoneurons5. This has been used to develop motoneuron isolation techniques to purify the cells from the vast majority of surrounding cells6. Isolating motoneurons with the help of specific antibodies (panning) against the extracellular domains of p75NTR has turned out to be an expensive method as the amount of antibody used for a single experiment is high due to the size of the plate used for panning. A much more economical alternative is the use of lectin. Lectin has been shown to specifically bind to p75NTR as well7. The following method describes an alternative technique using wheat germ agglutinin for a preplating procedure instead of the p75NTR antibody. The lectin is an extremely inexpensive alternative to the p75NTR antibody and the purification grades using

  12. PARTICULATE MATTER (PM) INHIBITS NEUROTROPHIN RELEASE FROM A549 CELLS

    EPA Science Inventory

    Several investigations have linked PM exposure to the exacerbation of allergic lung diseases. Many PM effects are mediated by cells within the lung including the airway epithelium, eosinophils, and lymphocytes. These cells also produce neurotophins such as NGF and/or express neur...

  13. Neurotrophins, cytokines, oxidative parameters and funcionality in Progressive Muscular Dystrophies.

    PubMed

    Comim, Clarissa M; Mathia, Gisiane B; Hoepers, Andreza; Tuon, Lisiane; Kapczinski, Flávio; Dal-Pizzol, Felipe; Quevedo, João; Rosa, Maria I

    2015-09-01

    We investigated the levels of brain derived-neurotrophic factor (BDNF), cytokines and oxidative parameters in serum and tried to correlate them with the age and functionality of patients with Progressive Muscle Dystrophies (PMD). The patients were separated into six groups (case and controls pared by age and gender), as follows: Duchenne Muscular Dystrophy (DMD); Steinert Myotonic Dystrophy (SMD); and Limb-girdle Muscular Dystrophy type-2A (LGMD2A). DMD patients (± 17.9 years old) had a decrease of functionality, an increase in the IL-1β and TNF-α levels and a decrease of IL-10 levels and superoxide dismutase activity in serum. SMD patients (± 25.8 years old) had a decrease of BDNF and IL-10 levels and superoxide dismutase activity and an increase of IL-1β levels in serum. LGMD2A patients (± 27.7 years old) had an decrease only in serum levels of IL-10. This research showed the first evidence of BDNF involvement in the SMD patients and a possible unbalance between pro-inflammatory and anti-inflammatory cytokine levels, along with decreased superoxide dismutase activity in serum of DMD and SMD patients. PMID:25910175

  14. A possible role of BDNF in prostate cancer detection.

    PubMed

    Bronzetti, E; Artico, M; Forte, F; Pagliarella, G; Felici, L M; D'Ambrosio, A; Vespasiani, G; Bronzetti, B

    2008-04-01

    Many studies have demonstrated that both normal and malignant prostate cells respond to a variety of growth factors, while several significant differences were found between normal and tumoural cells. The aim of this study was to focus on the localization and distribution of the immuno-reactivity for neurotrophins (NTs) and neurotrophin receptors (NTRs) in normal, hyperplastic and prostate cancer cells, obtained from 40 subjects. We studied samples obtained from 16 prostate cancer (PC, retropubic radical prostatectomy), 20 benign prostatic hyperplasia (BPH, supra-pubic prostatectomy) and normal peripheral prostate tissue from four fresh male cadavers. Samples were examined via immunohistochemical techniques in order to detect the expression of nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), neurotrophin 3 (NT3) and their own receptors TrkA, p75, TrkB and TrkC. We observed a high expression of BDNF and TrkB in PC and BPH, though no immuno-reactivity was found for p75. Low expression was reported by other NTs and NTRs in the normal peripheral prostate zone, BPH and PC. These data suggest a possible predictive role for NTs and NTRs, especially for BDNF and TrkB, in the diagnosis and/or management of prostate cancer. The absence of p75 expression confirms its supposed role in apoptotic phenomenon. PMID:18357383

  15. Complete genome sequence of Thermaerobacter marianensis type strain (7p75aT)

    SciTech Connect

    Han, Cliff; Gu, Wei; Hackett, M.; Zhang, Xiaojing; Lapidus, Alla L.; Nolan, Matt; Copeland, A; Lucas, Susan; Glavina Del Rio, Tijana; Tice, Hope; Cheng, Jan-Fang; Tapia, Roxanne; Goodwin, Lynne A.; Pitluck, Sam; Pagani, Ioanna; Ivanova, N; Mavromatis, K; Mikhailova, Natalia; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Land, Miriam L; Hauser, Loren John; Chang, Yun-Juan; Jeffries, Cynthia; Schneider, Susan; Rohde, Manfred; Goker, Markus; Pukall, Rudiger; Woyke, Tanja; Bristow, James; Eisen, Jonathan; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter; Detter, J. Chris

    2010-01-01

    Thermaerobacter marianensis Takai et al. 1999 is the type species of the genus Thermaerobacter, which belongs to the Clostridiales family Incertae Sedis XVII. The species is of special interest because T. marianensis is an aerobic, thermophilic marine bacterium, originally isolated from the deepest part in the western Pacific Ocean (Mariana Trench) at the depth of 10.897m. Interestingly, the taxonomic status of the genus has not been clarified until now. The genus Thermaerobacter may represent a very deep group within the Firmicutes or potentially a novel phylum. The 2,844,696 bp long genome with its 2,375 protein-coding and 60 RNA genes consists of one circular chromosome and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  16. FDA Approval: Palbociclib for the Treatment of Postmenopausal Patients with Estrogen Receptor-Positive, HER2-Negative Metastatic Breast Cancer.

    PubMed

    Beaver, Julia A; Amiri-Kordestani, Laleh; Charlab, Rosane; Chen, Wei; Palmby, Todd; Tilley, Amy; Zirkelbach, Jeanne Fourie; Yu, Jingyu; Liu, Qi; Zhao, Liang; Crich, Joyce; Chen, Xiao Hong; Hughes, Minerva; Bloomquist, Erik; Tang, Shenghui; Sridhara, Rajeshwari; Kluetz, Paul G; Kim, Geoffrey; Ibrahim, Amna; Pazdur, Richard; Cortazar, Patricia

    2015-11-01

    On February 3, 2015, the FDA granted accelerated approval to palbociclib (IBRANCE, Pfizer Inc.), an inhibitor of cyclin-dependent kinases 4 and 6 (CDK4 and CDK6), for use in combination with letrozole for the treatment of postmenopausal women with estrogen receptor (ER)-positive, HER2-negative advanced breast cancer as initial endocrine-based therapy for their metastatic disease. The approval is based on a randomized, multicenter, open-label phase I/II trial (PALOMA-1) in 165 patients randomized to palbociclib (125 mg orally daily for 21 consecutive days, followed by 7 days off treatment) plus letrozole (2.5 mg orally daily) or letrozole alone. The phase II portion of the trial was divided into two cohorts: cohort 1 enrolled 66 biomarker-unselected patients and cohort 2 enrolled 99 biomarker-positive patients. The major efficacy outcome measure was investigator-assessed progression-free survival (PFS). A large magnitude of improvement in PFS was observed in patients receiving palbociclib plus letrozole compared with patients receiving letrozole alone (HR, 0.488; 95% confidence interval, 0.319-0.748). Multiple sensitivity analyses were supportive of clinical benefit. The most common adverse reaction in patients receiving palbociclib plus letrozole was neutropenia. This article summarizes the FDA thought process and data supporting accelerated approval based on PALOMA-1 that may be contingent upon verification and description of clinical benefit in the ongoing and fully accrued confirmatory trial PALOMA-2. PMID:26324739

  17. Characterization of a Novel M1 Muscarinic Acetylcholine Receptor Positive Allosteric Modulator Radioligand, [3H]PT-1284.

    PubMed

    Smith, Deborah L; Davoren, Jennifer E; Edgerton, Jeremy R; Lazzaro, John T; Lee, Che-Wah; Neal, Sarah; Zhang, Lei; Grimwood, Sarah

    2016-09-01

    Selective activation of the M1 muscarinic acetylcholine receptor (mAChR) via a positive allosteric modulator (PAM) is a new approach for the treatment of the cognitive impairments associated with schizophrenia and Alzheimer's disease. Herein, we describe the characterization of an M1 PAM radioligand, 8-((1S,2S)-2-hydroxycyclohexyl)-5-((6-(methyl-t3)pyridin-3-yl)methyl)-8,9-dihydro-7H-pyrrolo[3,4-hour]quinolin-7-one ([(3)H]PT-1284), as a tool for characterizing the M1 allosteric binding site, as well as profiling novel M1 PAMs. 8-((1S,2S)-2-Hydroxycyclohexyl)-5-((6-methylpyridin-3-yl)methyl)-8,9-dihydro-7H-pyrrolo[3,4-hour]quinolin-7-one (PT-1284 ( 1: )) was shown to potentiate acetylcholine (ACh) in an M1 fluorometric imaging plate reader (FLIPR) functional assay (EC50, 36 nM) and carbachol in a hippocampal slice electrophysiology assay (EC50, 165 nM). PT-1284 ( 1: ) also reduced the concentration of ACh required to inhibit [(3)H]N-methylscopolamine ([(3)H]NMS) binding to M1, left-shifting the ACh Ki approximately 19-fold at 10 μM. Saturation analysis of a human M1 mAChR stable cell line showed that [(3)H]PT-1284 bound to M1 mAChR in the presence of 1 mM ACh with Kd, 4.23 nM, and saturable binding capacity (Bmax), 6.38 pmol/mg protein. M1 selective PAMs were shown to inhibit [(3)H]PT-1284 binding in a concentration-responsive manner, whereas M1 allosteric and orthosteric agonists showed weak affinity (>30 μM). A strong positive correlation (R(2) = 0.86) was found to exist between affinity values generated for nineteen M1 PAMs in the [(3)H]PT-1284 binding assay and the EC50 values of these ligands in a FLIPR functional potentiation assay. These data indicate that there is a strong positive correlation between M1 PAM binding affinity and functional activity, and that [(3)H]PT-1284 can serve as a tool for pharmacological investigation of M1 mAChR PAMs. PMID:27382013

  18. Early Adaptation and Acquired Resistance to CDK4/6 Inhibition in Estrogen Receptor-Positive Breast Cancer.

    PubMed

    Herrera-Abreu, Maria Teresa; Palafox, Marta; Asghar, Uzma; Rivas, Martín A; Cutts, Rosalind J; Garcia-Murillas, Isaac; Pearson, Alex; Guzman, Marta; Rodriguez, Olga; Grueso, Judit; Bellet, Meritxell; Cortés, Javier; Elliott, Richard; Pancholi, Sunil; Baselga, José; Dowsett, Mitch; Martin, Lesley-Ann; Turner, Nicholas C; Serra, Violeta

    2016-04-15

    Small-molecule inhibitors of the CDK4/6 cell-cycle kinases have shown clinical efficacy in estrogen receptor (ER)-positive metastatic breast cancer, although their cytostatic effects are limited by primary and acquired resistance. Here we report that ER-positive breast cancer cells can adapt quickly to CDK4/6 inhibition and evade cytostasis, in part, via noncanonical cyclin D1-CDK2-mediated S-phase entry. This adaptation was prevented by cotreatment with hormone therapies or PI3K inhibitors, which reduced the levels of cyclin D1 (CCND1) and other G1-S cyclins, abolished pRb phosphorylation, and inhibited activation of S-phase transcriptional programs. Combined targeting of both CDK4/6 and PI3K triggered cancer cell apoptosis in vitro and in patient-derived tumor xenograft (PDX) models, resulting in tumor regression and improved disease control. Furthermore, a triple combination of endocrine therapy, CDK4/6, and PI3K inhibition was more effective than paired combinations, provoking rapid tumor regressions in a PDX model. Mechanistic investigations showed that acquired resistance to CDK4/6 inhibition resulted from bypass of cyclin D1-CDK4/6 dependency through selection of CCNE1 amplification or RB1 loss. Notably, although PI3K inhibitors could prevent