Muscle Stem Cells Undergo Extensive Clonal Drift during Tissue Growth via Meox1-Mediated Induction of G2 Cell-Cycle Arrest.

PubMed

Nguyen, Phong Dang; Gurevich, David Baruch; Sonntag, Carmen; Hersey, Lucy; Alaei, Sara; Nim, Hieu Tri; Siegel, Ashley; Hall, Thomas Edward; Rossello, Fernando Jaime; Boyd, Sarah Elizabeth; Polo, Jose Maria; Currie, Peter David

2017-07-06

Organ growth requires a careful balance between stem cell self-renewal and lineage commitment to ensure proper tissue expansion. The cellular and molecular mechanisms that mediate this balance are unresolved in most organs, including skeletal muscle. Here we identify a long-lived stem cell pool that mediates growth of the zebrafish myotome. This population exhibits extensive clonal drift, shifting from random deployment of stem cells during development to reliance on a small number of dominant clones to fuel the vast majority of muscle growth. This clonal drift requires Meox1, a homeobox protein that directly inhibits the cell-cycle checkpoint gene ccnb1. Meox1 initiates G 2 cell-cycle arrest within muscle stem cells, and disrupting this G 2 arrest causes premature lineage commitment and the resulting defects in muscle growth. These findings reveal that distinct regulatory mechanisms orchestrate stem cell dynamics during organ growth, beyond the G 0 /G 1 cell-cycle inhibition traditionally associated with maintaining tissue-resident stem cells. Copyright © 2017. Published by Elsevier Inc.

Genetic modification through oligonucleotide-mediated mutagenesis. A GMO regulatory challenge?

PubMed

Breyer, Didier; Herman, Philippe; Brandenburger, Annick; Gheysen, Godelieve; Remaut, Erik; Soumillion, Patrice; Van Doorsselaere, Jan; Custers, René; Pauwels, Katia; Sneyers, Myriam; Reheul, Dirk

2009-01-01

In the European Union, the definition of a GMO is technology-based. This means that a novel organism will be regulated under the GMO regulatory framework only if it has been developed with the use of defined techniques. This approach is now challenged with the emergence of new techniques. In this paper, we describe regulatory and safety issues associated with the use of oligonucleotide-mediated mutagenesis to develop novel organisms. We present scientific arguments for not having organisms developed through this technique fall within the scope of the EU regulation on GMOs. We conclude that any political decision on this issue should be taken on the basis of a broad reflection at EU level, while avoiding discrepancies at international level.

Constitutive Smad linker phosphorylation in melanoma: A mechanism of resistance to Transforming Growth Factor-β-mediated growth inhibition

PubMed Central

Cohen-Solal, Karine A.; Merrigan, Kim T.; Chan, Joseph L.-K.; Goydos, James S.; Chen, Wenjin; Foran, David J.; Liu, Fang; Lasfar, Ahmed; Reiss, Michael

2011-01-01

SUMMARY Melanoma cells are resistant to Transforming Growth Factor-β (TGFβ)-induced cell cycle arrest. In this study, we investigated a mechanism of resistance involving a regulatory domain, called linker region, in Smad2 and Smad3, main downstream effectors of TGFβ. Melanoma cells in culture and in tumor samples exhibited constitutive Smad2 and Smad3 linker phosphorylation. Treatment of melanoma cells with the MEK1/2 inhibitor, U0126, or the two pan-CDK and GSK3 inhibitors, Flavopiridol and R547, resulted in decreased linker phosphorylation of Smad2 and Smad3. Overexpression of the linker phosphorylation-resistant Smad3 EPSM mutant in melanoma cells resulted in an increase in expression of p15INK4B and p21WAF1, as compared with cells transfected with wild-type Smad3. In addition, the cell numbers of EPSM Smad3-expressing melanoma cells were significantly reduced compared to wild-type Smad3-expressing cells. These results suggest that the linker phosphorylation of Smad3 contributes to the resistance of melanoma cells to TGFβ-mediated growth inhibition. PMID:21477078

Genome-wide analysis of the regulatory function mediated by the small regulatory psm-mec RNA of methicillin-resistant Staphylococcus aureus.

PubMed

Cheung, Gordon Y C; Villaruz, Amer E; Joo, Hwang-Soo; Duong, Anthony C; Yeh, Anthony J; Nguyen, Thuan H; Sturdevant, Daniel E; Queck, S Y; Otto, M

2014-07-01

Several methicillin resistance (SCCmec) clusters characteristic of hospital-associated methicillin-resistant Staphylococcus aureus (MRSA) strains harbor the psm-mec locus. In addition to encoding the cytolysin, phenol-soluble modulin (PSM)-mec, this locus has been attributed gene regulatory functions. Here we employed genome-wide transcriptional profiling to define the regulatory function of the psm-mec locus. The immune evasion factor protein A emerged as the primary conserved and strongly regulated target of psm-mec, an effect we show is mediated by the psm-mec RNA. Furthermore, the psm-mec locus exerted regulatory effects that were more moderate in extent. For example, expression of PSM-mec limited expression of mecA, thereby decreasing methicillin resistance. Our study shows that the psm-mec locus has a rare dual regulatory RNA and encoded cytolysin function. Furthermore, our findings reveal a specific mechanism underscoring the recently emerging concept that S. aureus strains balance pronounced virulence and high expression of antibiotic resistance. Published by Elsevier GmbH.

GSK3 controls axon growth via CLASP-mediated regulation of growth cone microtubules

PubMed Central

Hur, Eun-Mi; Saijilafu; Lee, Byoung Dae; Kim, Seong-Jin; Xu, Wen-Lin; Zhou, Feng-Quan

2011-01-01

Suppression of glycogen synthase kinase 3 (GSK3) activity in neurons yields pleiotropic outcomes, causing both axon growth promotion and inhibition. Previous studies have suggested that specific GSK3 substrates, such as adenomatous polyposis coli (APC) and collapsin response mediator protein 2 (CRMP2), support axon growth by regulating the stability of axonal microtubules (MTs), but the substrate(s) and mechanisms conveying axon growth inhibition remain elusive. Here we show that CLIP (cytoplasmic linker protein)-associated protein (CLASP), originally identified as a MT plus end-binding protein, displays both plus end-binding and lattice-binding activities in nerve growth cones, and reveal that the two MT-binding activities regulate axon growth in an opposing manner: The lattice-binding activity mediates axon growth inhibition induced by suppression of GSK3 activity via preventing MT protrusion into the growth cone periphery, whereas the plus end-binding property supports axon extension via stabilizing the growing ends of axonal MTs. We propose a model in which CLASP transduces GSK3 activity levels to differentially control axon growth by coordinating the stability and configuration of growth cone MTs. PMID:21937714

Regulatory design governing progression of population growth phases in bacteria.

PubMed

Martínez-Antonio, Agustino; Lomnitz, Jason G; Sandoval, Santiago; Aldana, Maximino; Savageau, Michael A

2012-01-01

It has long been noted that batch cultures inoculated with resting bacteria exhibit a progression of growth phases traditionally labeled lag, exponential, pre-stationary and stationary. However, a detailed molecular description of the mechanisms controlling the transitions between these phases is lacking. A core circuit, formed by a subset of regulatory interactions involving five global transcription factors (FIS, HNS, IHF, RpoS and GadX), has been identified by correlating information from the well- established transcriptional regulatory network of Escherichia coli and genome-wide expression data from cultures in these different growth phases. We propose a functional role for this circuit in controlling progression through these phases. Two alternative hypotheses for controlling the transition between the growth phases are first, a continuous graded adjustment to changing environmental conditions, and second, a discontinuous hysteretic switch at critical thresholds between growth phases. We formulate a simple mathematical model of the core circuit, consisting of differential equations based on the power-law formalism, and show by mathematical and computer-assisted analysis that there are critical conditions among the parameters of the model that can lead to hysteretic switch behavior, which--if validated experimentally--would suggest that the transitions between different growth phases might be analogous to cellular differentiation. Based on these provocative results, we propose experiments to test the alternative hypotheses.

Expression of Genes Involved in Bacteriocin Production and Self-Resistance in Lactobacillus brevis 174A Is Mediated by Two Regulatory Proteins.

PubMed

Noda, Masafumi; Miyauchi, Rumi; Danshiitsoodol, Narandalai; Matoba, Yasuyuki; Kumagai, Takanori; Sugiyama, Masanori

2018-04-01

We have previously shown that the lactic acid bacterium Lactobacillus brevis 174A, isolated from Citrus iyo fruit, produces a bacteriocin designated brevicin 174A, which is comprised of two antibacterial polypeptides (designated brevicins 174A-β and 174A-γ). We have also found a gene cluster, composed of eight open reading frames (ORFs), that contains genes for the biosynthesis of brevicin 174A, self-resistance to its own bacteriocin, and two transcriptional regulatory proteins. Some lactic acid bacterial strains have a system to start the production of bacteriocin at an adequate stage of growth. Generally, the system consists of a membrane-bound histidine protein kinase (HPK) that senses a specific environmental stimulus and a corresponding response regulator (RR) that mediates the cellular response. We have previously shown that although the HPK- and RR-encoding genes are not found on the brevicin 174A biosynthetic gene cluster in the 174A strain, two putative regulatory genes, designated breD and breG , are in the gene cluster. In the present study, we demonstrate that the expression of brevicin 174A production and self-resistance is positively controlled by two transcriptional regulatory proteins, designated BreD and BreG. BreD is expressed together with BreE as the self-resistance determinant of L. brevis 174A. DNase I footprinting analysis and a promoter assay demonstrated that BreD binds to the breED promoter as a positive autoregulator. The present study also demonstrates that BreG, carrying a transmembrane domain, binds to the common promoter of breB and breC , encoding brevicins 174A-β and 174A-γ, respectively, for positive regulation. IMPORTANCE The problem of the appearance of bacteria that are resistant to practical antibiotics and the increasing demand for safe foods have increased interest in replacing conventional antibiotics with bacteriocin produced by the lactic acid bacteria. This antibacterial substance can inhibit the growth of pathogenic

Constitutive Smad linker phosphorylation in melanoma: a mechanism of resistance to transforming growth factor-β-mediated growth inhibition.

PubMed

Cohen-Solal, Karine A; Merrigan, Kim T; Chan, Joseph L-K; Goydos, James S; Chen, Wenjin; Foran, David J; Liu, Fang; Lasfar, Ahmed; Reiss, Michael

2011-06-01

Melanoma cells are resistant to transforming growth factor-β (TGFβ)-induced cell-cycle arrest. In this study, we investigated a mechanism of resistance involving a regulatory domain, called linker region, in Smad2 and Smad3, main downstream effectors of TGFβ. Melanoma cells in culture and tumor samples exhibited constitutive Smad2 and Smad3 linker phosphorylation. Treatment of melanoma cells with the MEK1/2 inhibitor, U0126, or the two pan-CDK and GSK3 inhibitors, Flavopiridol and R547, resulted in decreased linker phosphorylation of Smad2 and Smad3. Overexpression of the linker phosphorylation-resistant Smad3 EPSM mutant in melanoma cells resulted in an increase in expression of p15(INK4B) and p21(WAF1) , as compared with cells transfected with wild-type (WT) Smad3. In addition, the cell numbers of EPSM Smad3-expressing melanoma cells were significantly reduced compared with WT Smad3-expressing cells. These results suggest that the linker phosphorylation of Smad3 contributes to the resistance of melanoma cells to TGFβ-mediated growth inhibition. 2011 John Wiley & Sons A/S.

Uncovering MicroRNA and Transcription Factor Mediated Regulatory Networks in Glioblastoma

PubMed Central

Sun, Jingchun; Gong, Xue; Purow, Benjamin; Zhao, Zhongming

2012-01-01

Glioblastoma multiforme (GBM) is the most common and lethal brain tumor in humans. Recent studies revealed that patterns of microRNA (miRNA) expression in GBM tissue samples are different from those in normal brain tissues, suggesting that a number of miRNAs play critical roles in the pathogenesis of GBM. However, little is yet known about which miRNAs play central roles in the pathology of GBM and their regulatory mechanisms of action. To address this issue, in this study, we systematically explored the main regulation format (feed-forward loops, FFLs) consisting of miRNAs, transcription factors (TFs) and their impacting GBM-related genes, and developed a computational approach to construct a miRNA-TF regulatory network. First, we compiled GBM-related miRNAs, GBM-related genes, and known human TFs. We then identified 1,128 3-node FFLs and 805 4-node FFLs with statistical significance. By merging these FFLs together, we constructed a comprehensive GBM-specific miRNA-TF mediated regulatory network. Then, from the network, we extracted a composite GBM-specific regulatory network. To illustrate the GBM-specific regulatory network is promising for identification of critical miRNA components, we specifically examined a Notch signaling pathway subnetwork. Our follow up topological and functional analyses of the subnetwork revealed that six miRNAs (miR-124, miR-137, miR-219-5p, miR-34a, miR-9, and miR-92b) might play important roles in GBM, including some results that are supported by previous studies. In this study, we have developed a computational framework to construct a miRNA-TF regulatory network and generated the first miRNA-TF regulatory network for GBM, providing a valuable resource for further understanding the complex regulatory mechanisms in GBM. The observation of critical miRNAs in the Notch signaling pathway, with partial verification from previous studies, demonstrates that our network-based approach is promising for the identification of new and important

Regulatory Focus as a Mediator of the Influence of Initiating Structure and Servant Leadership on Employee Behavior

ERIC Educational Resources Information Center

Neubert, Mitchell J.; Kacmar, K. Michele; Carlson, Dawn S.; Chonko, Lawrence B.; Roberts, James A.

2008-01-01

In this research, the authors test a model in which the regulatory focus of employees at work mediates the influence of leadership on employee behavior. In a nationally representative sample of 250 workers who responded over 2 time periods, prevention focus mediated the relationship of initiating structure to in-role performance and deviant…

Hypothalamic AMP-activated protein kinase mediates counter-regulatory responses to hypoglycaemia in rats.

PubMed

Han, S-M; Namkoong, C; Jang, P G; Park, I S; Hong, S W; Katakami, H; Chun, S; Kim, S W; Park, J-Y; Lee, K-U; Kim, M-S

2005-10-01

Appropriate counter-regulatory hormonal responses are essential for recovery from hypoglycaemia. Although the hypothalamus is known to be involved in these responses, the molecular mechanisms have not been fully elucidated. AMP-activated protein kinase (AMPK) functions as a cellular energy sensor, being activated during energy depletion. As AMPK is expressed in the hypothalamus, an important site of neuroendocrine regulation, the present study was undertaken to determine whether hypothalamic AMPK mediates counter-regulatory responses to hypoglycaemia. Hypoglycaemia was induced by i.p. injection of regular insulin (6 U/kg) in Sprague-Dawley rats. Hypothalamic AMPK phosphorylation and activities were determined 1 h after i.p. insulin injection. To investigate the role of hypothalamic AMPK activation in mediating counter-regulatory responses, an AMPK inhibitor, compound C, was pre-administered intracerebroventricularly (i.c.v.) or dominant-negative (DN)-AMPK was overexpressed in the hypothalamus before induction of hypoglycaemia. Insulin-induced hypoglycaemia increased hypothalamic AMPK phosphorylation and alpha2-AMPK activities in rats. The change was significant in the arcuate nucleus/ventromedial hypothalamus (ARC/VMH) and paraventricular nuclei (PVN). Prior i.c.v. administration of compound C attenuated hypoglycaemia-induced increases in plasma concentrations of corticosterone, glucagon and catecholamines, resulting in severe and prolonged hypoglycaemia. ARC/VMH DN-AMPK overexpression impaired early counter-regulation, as evidenced by reduced glucagon and catecholamine responses. In contrast, PVN DN-AMPK overexpression attenuated late counter-regulation and corticosterone responses. Systemic hypoglycaemia causes hypothalamic AMPK activation, which is important for counter-regulatory hormonal responses. Our data indicate that hypothalamic AMPK acts as a fuel gauge, sensing the whole-body energy state and regulating not only energy homeostasis but also

Tumor-secreted miR-214 induces regulatory T cells: a major link between immune evasion and tumor growth

PubMed Central

Yin, Yuan; Cai, Xing; Chen, Xi; Liang, Hongwei; Zhang, Yujing; Li, Jing; Wang, Zuoyun; Chen, Xiulan; Zhang, Wen; Yokoyama, Seiji; Wang, Cheng; Li, Liang; Li, Limin; Hou, Dongxia; Dong, Lei; Xu, Tao; Hiroi, Takachika; Yang, Fuquan; Ji, Hongbin; Zhang, Junfeng; Zen, Ke; Zhang, Chen-Yu

2014-01-01

An increased population of CD4+CD25highFoxp3+ regulatory T cells (Tregs) in the tumor-associated microenvironment plays an important role in cancer immune evasion. However, the underlying mechanism remains unclear. Here we observed an increased secretion of miR-214 in various types of human cancers and mouse tumor models. Tumor-secreted miR-214 was sufficiently delivered into recipient T cells by microvesicles (MVs). In targeted mouse peripheral CD4+ T cells, tumor-derived miR-214 efficiently downregulated phosphatase and tensin homolog (PTEN) and promoted Treg expansion. The miR-214-induced Tregs secreted higher levels of IL-10 and promoted tumor growth in nude mice. Furthermore, in vivo studies indicated that Treg expansion mediated by cancer cell-secreted miR-214 resulted in enhanced immune suppression and tumor implantation/growth in mice. The MV delivery of anti-miR-214 antisense oligonucleotides (ASOs) into mice implanted with tumors blocked Treg expansion and tumor growth. Our study reveals a novel mechanism through which cancer cell actively manipulates immune response via promoting Treg expansion. PMID:25223704

Immune Tolerance to Apoptotic Self Is Mediated Primarily by Regulatory B1a Cells.

PubMed

Miles, Katherine; Simpson, Joanne; Brown, Sheila; Cowan, Graeme; Gray, David; Gray, Mohini

2017-01-01

The chronic autoimmune inflammatory diseases, systemic lupus erythematosus and Sjogren's syndrome, develop when tolerance to apoptotic cells (ACs) is lost. We have previously reported that this tolerance is maintained by innate-like, IL-10 secreting regulatory B cells. Two questions remained. First, do these regulatory B cells belong predominantly to a single subset of steady-state B cells and second, what is their specificity? We report here that innate-like B cells with markers characteristic for B1a cells (CD43 +ve CD19 hi CD5 +ve IgM hi IgD lo ) constitute 80% of splenic and 96% of peritoneal B cells that respond to ACs by secreting IL-10. AC responsive B1a cells secrete self-reactive natural antibodies (NAbs) and IL-10, which is augmented by toll-like receptor (TLR) 7 or TLR9 stimulation. In so doing, they both accelerate the clearance of dying cells by macrophages and inhibit their potential to mount proinflammatory immune responses. While B1a cells make prolonged contact with ACs, they do not require TIM1 or complement to mediate their regulatory function. In an animal model of neural inflammation (experimental autoimmune encephalomyelitis), just 10 5 activated B1a B cells was sufficient to restrain inflammation. Activated B1a B cells also induced antigen-specific T cells to secrete IL-10. Hence, regulatory B1a cells specifically recognize and augment tolerance to apoptotic self via IL-10 and NAbs; but once activated, can also prevent autoimmune mediated inflammation.

Growth and stress response mechanisms underlying post-feeding regenerative organ growth in the Burmese python.

PubMed

Andrew, Audra L; Perry, Blair W; Card, Daren C; Schield, Drew R; Ruggiero, Robert P; McGaugh, Suzanne E; Choudhary, Amit; Secor, Stephen M; Castoe, Todd A

2017-05-02

Previous studies examining post-feeding organ regeneration in the Burmese python (Python molurus bivittatus) have identified thousands of genes that are significantly differentially regulated during this process. However, substantial gaps remain in our understanding of coherent mechanisms and specific growth pathways that underlie these rapid and extensive shifts in organ form and function. Here we addressed these gaps by comparing gene expression in the Burmese python heart, liver, kidney, and small intestine across pre- and post-feeding time points (fasted, one day post-feeding, and four days post-feeding), and by conducting detailed analyses of molecular pathways and predictions of upstream regulatory molecules across these organ systems. Identified enriched canonical pathways and upstream regulators indicate that while downstream transcriptional responses are fairly tissue specific, a suite of core pathways and upstream regulator molecules are shared among responsive tissues. Pathways such as mTOR signaling, PPAR/LXR/RXR signaling, and NRF2-mediated oxidative stress response are significantly differentially regulated in multiple tissues, indicative of cell growth and proliferation along with coordinated cell-protective stress responses. Upstream regulatory molecule analyses identify multiple growth factors, kinase receptors, and transmembrane receptors, both within individual organs and across separate tissues. Downstream transcription factors MYC and SREBF are induced in all tissues. These results suggest that largely divergent patterns of post-feeding gene regulation across tissues are mediated by a core set of higher-level signaling molecules. Consistent enrichment of the NRF2-mediated oxidative stress response indicates this pathway may be particularly important in mediating cellular stress during such extreme regenerative growth.

Underpotential deposition-mediated layer-by-layer growth of thin films

DOEpatents

Wang, Jia Xu; Adzic, Radoslav R.

2015-05-19

A method of depositing contiguous, conformal submonolayer-to-multilayer thin films with atomic-level control is described. The process involves the use of underpotential deposition of a first element to mediate the growth of a second material by overpotential deposition. Deposition occurs between a potential positive to the bulk deposition potential for the mediating element where a full monolayer of mediating element forms, and a potential which is less than, or only slightly greater than, the bulk deposition potential of the material to be deposited. By cycling the applied voltage between the bulk deposition potential for the mediating element and the material to be deposited, repeated desorption/adsorption of the mediating element during each potential cycle can be used to precisely control film growth on a layer-by-layer basis. This process is especially suitable for the formation of a catalytically active layer on core-shell particles for use in energy conversion devices such as fuel cells.

Regulatory T cells decrease invariant natural killer T cell-mediated pregnancy loss in mice.

PubMed

Li, L; Tu, J; Jiang, Y; Zhou, J; Schust, D J

2017-05-01

Pregnancy loss is the commonest complication of pregnancy. The causes of pregnancy loss are poorly understood. It has been reported that stimulation of invariant natural killer T (iNKT) cells using α-galactosylceramide (αGC) induces pregnancy loss in mice. Here we investigated the mechanisms, especially the role of regulatory T (Treg) cells, in iNKT cell-mediated pregnancy loss. We found that injection of αGC rapidly induced fetal resorption, activated decidual iNKT cells, decreased the percentage of decidual Treg cells and their interleukin (IL)-10 and transforming growth factor (TGF)-β production, and upregulated the levels of interferon (IFN)-γ, tumor necrosis factor-α, IL-4, and IL-10 in serum. Adoptive transfer of iNKT cells from wild-type (WT) and IL-4 -/- mice but not IFN-γ -/- mice into αGC-treated iNKT cell-deficient Jα18 -/- mice restored αGC-induced pregnancy loss. Adoptive transfer of Treg cells downregulated α-GC-induced pregnancy loss in WT mice. Finally, co-culture with αGC-stimulated decidual iNKT cells decreased the production of IL-10 and TGF-β in decidual Treg cells and inhibited their suppressive activity. These findings suggest that activation of iNKT cells induces pregnancy loss in mice in an IFN-γ-dependent manner. In addition, inhibition of the function of decidual Treg cells has an important role in iNKT cell-mediated pregnancy loss.

Ultrasound-mediated interferon {beta} gene transfection inhibits growth of malignant melanoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamaguchi, Kazuki; Department of Anatomy, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka City 814-0180; Feril, Loreto B., E-mail: ferilism@yahoo.com

2011-07-22

Highlights: {yields} Successful ultrasound-mediated transfection of melanoma (C32) cells with IFN-{beta} genes both in vitro and in vivo. {yields} Ultrasound-mediated IFN-{beta} transfection inhibited proliferation of melanoma cells in vitro. {yields} Ultrasound-mediated IFN-{beta} transfection inhibited melanoma tumor growth in vivo. -- Abstract: We investigated the effects of ultrasound-mediated transfection (sonotransfection) of interferon {beta} (IFN-{beta}) gene on melanoma (C32) both in vitro and in vivo. C32 cells were sonotransfected with IFN-{beta} in vitro. Subcutaneous C32 tumors in mice were sonicated weekly immediately after intra-tumor injection with IFN-{beta} genes mixed with microbubbles. Successful sonotransfection with IFN-{beta} gene in vitro was confirmed by ELISA,more » which resulted in C32 growth inhibition. In vivo, the growth ratio of tumors transfected with IFN-{beta} gene was significantly lower than the other experimental groups. These results may lead to a new method of treatment against melanoma and other hard-to-treat cancers.« less

Impulsivity, perceived self-regulatory success in dieting, and body mass in children and adolescents: A moderated mediation model.

PubMed

Meule, Adrian; Hofmann, Johannes; Weghuber, Daniel; Blechert, Jens

2016-12-01

Impulsivity has been suggested to contribute to overeating and obesity. However, findings are inconsistent and it appears that only specific facets of impulsivity are related to eating-related variables and to body mass. In the current study, relationships between self-reported impulsivity, perceived self-regulatory success in dieting, and objectively measured body mass were examined in N = 122 children and adolescents. Scores on attentional and motor impulsivity interactively predicted perceived self-regulatory success in dieting, but not body mass: Higher attentional impulsivity was associated with lower perceived self-regulatory success at high levels of motor impulsivity, but not at low levels of motor impulsivity. A moderated mediation model revealed an indirect effect of attentional and motor impulsivity on body mass, which was mediated by perceived self-regulatory success in dieting. Thus, results show that only specific facets of impulsivity are relevant in eating- and weight-regulation and interact with each other in the prediction of these variables. These facets of impulsivity, however, are not directly related to higher body mass, but indirectly via lower success in eating-related self-regulation in children and adolescents. Copyright © 2016 Elsevier Ltd. All rights reserved.

Alk5-Mediated Transforming Growth Factor β Signaling Acts Upstream of Fibroblast Growth Factor 10 To Regulate the Proliferation and Maintenance of Dental Epithelial Stem Cells▿

PubMed Central

Zhao, Hu; Li, Sha; Han, Dong; Kaartinen, Vesa; Chai, Yang

2011-01-01

Mouse incisors grow continuously throughout life. This growth is supported by the division of dental epithelial stem cells that reside in the cervical loop region. Little is known about the maintenance and regulatory mechanisms of dental epithelial stem cells. In the present study, we investigated how transforming growth factor β (TGF-β) signaling-mediated mesenchymal-epithelial cell interactions control dental epithelial stem cells. We designed two approaches using incisor organ culture and bromodeoxyuridine (BrdU) pulse-chase experiments to identify and evaluate stem cell functions. We show that the loss of the TGF-β type I receptor (Alk5) in the cranial neural crest-derived dental mesenchyme severely affects the proliferation of TA (transit-amplifying) cells and the maintenance of dental epithelial stem cells. Incisors of Wnt1-Cre; Alk5fl/fl mice lost their ability to continue to grow in vitro. The number of BrdU label-retaining cells (LRCs) was dramatically reduced in Alk5 mutant mice. Fgf10, Fgf3, and Fgf9 signals in the dental mesenchyme were downregulated in Wnt1-Cre; Alk5fl/fl incisors. Strikingly, the addition of exogenous fibroblast growth factor 10 (FGF10) into cultured incisors rescued dental epithelial stem cells in Wnt1-Cre; Alk5fl/fl mice. Therefore, we propose that Alk5 functions upstream of Fgf10 to regulate TA cell proliferation and stem cell maintenance and that this signaling mechanism is crucial for stem cell-mediated tooth regeneration. PMID:21402782

Actin growth profile in clathrin-mediated endocytosis

NASA Astrophysics Data System (ADS)

Tweten, D. J.; Bayly, P. V.; Carlsson, A. E.

2017-05-01

Clathrin-mediated endocytosis in yeast is driven by a protein patch containing close to 100 different types of proteins. Among the proteins are 5000 -10 000 copies of polymerized actin, and successful endocytosis requires growth of the actin network. Since it is not known exactly how actin network growth drives endocytosis, we calculate the spatial distribution of actin growth required to generate the force that drives the process. First, we establish the force distribution that must be supplied by actin growth, by combining membrane-bending profiles obtained via electron microscopy with established theories of membrane mechanics. Next, we determine the profile of actin growth, using a continuum mechanics approach and an iterative procedure starting with an actin growth profile obtained from a linear analysis. The profile has fairly constant growth outside a central hole of radius 45-50 nm, but very little growth in this hole. This growth profile can reproduce the required forces if the actin shear modulus exceeds 80 kPa, and the growing filaments can exert very large polymerization forces. The growth profile prediction could be tested via electron-microscopy or super-resolution experiments in which the turgor pressure is suddenly turned off.

Feline glycoprotein A repetitions predominant anchors transforming growth factor beta on the surface of activated CD4(+)CD25(+) regulatory T cells and mediates AIDS lentivirus-induced T cell immunodeficiency.

PubMed

Miller, Michelle M; Fogle, Jonathan E; Ross, Peter; Tompkins, Mary B

2013-04-01

Using the feline immunodeficiency virus (FIV) model for AIDS-lentivirus infection, our laboratory has previously demonstrated that T regulatory (Treg) cell-mediated immune T and B cell dysfunction contributes to lentivirus persistence and chronic disease through membrane bound transforming growth factor beta (mTGFb). Studying Treg cells in the context of infection has been problematic as no inducible marker for activated Treg cells had been identified. However, recent reports in human Treg studies have described a novel protein, glycoprotein A repetitions predominant (GARP), as a unique marker of activated human Treg cells that anchors mTGFb. Herein we extend these studies to the feline Treg system, identifying feline GARP and demonstrating that human and feline GARP proteins are homologous in structure, expression pattern, and ability to form a complex with TGFb. We further demonstrate that GARP and TGFb form a complex on the surface of activated Treg cells and that these GARP(+)TGFb(+) Treg cells are highly efficient suppressor cells. Analysis of expression of this Treg activation marker in the FIV-AIDS model reveals an up-regulation of GARP expressing Treg cells during chronic FIV infection. We demonstrate that the GARP(+) Treg cells from FIV-infected cats suppress T helper cells in vivo and that blocking GARP or TGFb eliminates this suppression. These data suggest that GARP is expressed in complex with TGFb on the surface of activated Treg cells and plays an important role in TGFb(+) Treg-mediated T cell immune suppression during lentivirus infection.

Shaping skeletal growth by modular regulatory elements in the Bmp5 gene.

PubMed

Guenther, Catherine; Pantalena-Filho, Luiz; Kingsley, David M

2008-12-01

Cartilage and bone are formed into a remarkable range of shapes and sizes that underlie many anatomical adaptations to different lifestyles in vertebrates. Although the morphological blueprints for individual cartilage and bony structures must somehow be encoded in the genome, we currently know little about the detailed genomic mechanisms that direct precise growth patterns for particular bones. We have carried out large-scale enhancer surveys to identify the regulatory architecture controlling developmental expression of the mouse Bmp5 gene, which encodes a secreted signaling molecule required for normal morphology of specific skeletal features. Although Bmp5 is expressed in many skeletal precursors, different enhancers control expression in individual bones. Remarkably, we show here that different enhancers also exist for highly restricted spatial subdomains along the surface of individual skeletal structures, including ribs and nasal cartilages. Transgenic, null, and regulatory mutations confirm that these anatomy-specific sequences are sufficient to trigger local changes in skeletal morphology and are required for establishing normal growth rates on separate bone surfaces. Our findings suggest that individual bones are composite structures whose detailed growth patterns are built from many smaller lineage and gene expression domains. Individual enhancers in BMP genes provide a genomic mechanism for controlling precise growth domains in particular cartilages and bones, making it possible to separately regulate skeletal anatomy at highly specific locations in the body.

Self-Regulatory Processes Mediating between Career Calling and Perceived Employability and Life Satisfaction in Emerging Adults

ERIC Educational Resources Information Center

Praskova, Anna; Creed, Peter A.; Hood, Michelle

2015-01-01

We tested a cross-sectional, mediation model of career calling, in which career calling was associated positively with life satisfaction and perceptions of future employability, and these relationships were explained by the self-regulatory mechanisms of work effort, career strategies, and emotional regulation. Using a sample of 664 emerging adults…

The transcriptional regulator BZR1 mediates trade-off between plant innate immunity and growth.

PubMed

Lozano-Durán, Rosa; Macho, Alberto P; Boutrot, Freddy; Segonzac, Cécile; Somssich, Imre E; Zipfel, Cyril

2013-12-31

The molecular mechanisms underlying the trade-off between plant innate immunity and steroid-mediated growth are controversial. Here, we report that activation of the transcription factor BZR1 is required and sufficient for suppression of immune signaling by brassinosteroids (BR). BZR1 induces the expression of several WRKY transcription factors that negatively control early immune responses. In addition, BZR1 associates with WRKY40 to mediate the antagonism between BR and immune signaling. We reveal that BZR1-mediated inhibition of immunity is particularly relevant when plant fast growth is required, such as during etiolation. Thus, BZR1 acts as an important regulator mediating the trade-off between growth and immunity upon integration of environmental cues. DOI: http://dx.doi.org/10.7554/eLife.00983.001.

The Relationship Between Regulatory Emotional Self-Efficacy and Core Self-Evaluation of College Students: The Mediation Effects of Suicidal Attitude.

PubMed

Zhao, Xiaojun; Shi, Changxiu

2018-01-01

This study analyzed the mediation effect of a suicidal attitude from regulatory emotional self-efficacy to core self-evaluation. A measurement study was conducted among 438 college students using the Regulatory Emotional Self-Efficacy Scale, the Core Self-Evaluation Scale, and the Suicide Attitude Questionnaire. Results from the plug-in process in SPSS and the bootstrap method showed that the attitude toward suicidal behavior and the attitude toward family members of an individual who has committed suicide played a double-mediation role, from perceived self-efficacy in managing happiness to core self-evaluation. The results also showed that the attitude toward a person who committed suicide or attempted suicide played a mediation effect from perceived self-efficacy in managing curiousness to core self-evaluation. This research has great significance for improving the understanding of college students' sense of happiness and prevention for self-evaluation.

The Relationship Between Regulatory Emotional Self-Efficacy and Core Self-Evaluation of College Students: The Mediation Effects of Suicidal Attitude

PubMed Central

Zhao, Xiaojun; Shi, Changxiu

2018-01-01

This study analyzed the mediation effect of a suicidal attitude from regulatory emotional self-efficacy to core self-evaluation. A measurement study was conducted among 438 college students using the Regulatory Emotional Self-Efficacy Scale, the Core Self-Evaluation Scale, and the Suicide Attitude Questionnaire. Results from the plug-in process in SPSS and the bootstrap method showed that the attitude toward suicidal behavior and the attitude toward family members of an individual who has committed suicide played a double-mediation role, from perceived self-efficacy in managing happiness to core self-evaluation. The results also showed that the attitude toward a person who committed suicide or attempted suicide played a mediation effect from perceived self-efficacy in managing curiousness to core self-evaluation. This research has great significance for improving the understanding of college students’ sense of happiness and prevention for self-evaluation. PMID:29740378

Feline Glycoprotein A Repetitions Predominant Anchors Transforming Growth Factor Beta on the Surface of Activated CD4+CD25+ Regulatory T Cells and Mediates AIDS Lentivirus-Induced T Cell Immunodeficiency

PubMed Central

Miller, Michelle M.; Fogle, Jonathan E.; Ross, Peter

2013-01-01

Abstract Using the feline immunodeficiency virus (FIV) model for AIDS-lentivirus infection, our laboratory has previously demonstrated that T regulatory (Treg) cell-mediated immune T and B cell dysfunction contributes to lentivirus persistence and chronic disease through membrane bound transforming growth factor beta (mTGFb). Studying Treg cells in the context of infection has been problematic as no inducible marker for activated Treg cells had been identified. However, recent reports in human Treg studies have described a novel protein, glycoprotein A repetitions predominant (GARP), as a unique marker of activated human Treg cells that anchors mTGFb. Herein we extend these studies to the feline Treg system, identifying feline GARP and demonstrating that human and feline GARP proteins are homologous in structure, expression pattern, and ability to form a complex with TGFb. We further demonstrate that GARP and TGFb form a complex on the surface of activated Treg cells and that these GARP+TGFb+ Treg cells are highly efficient suppressor cells. Analysis of expression of this Treg activation marker in the FIV-AIDS model reveals an up-regulation of GARP expressing Treg cells during chronic FIV infection. We demonstrate that the GARP+ Treg cells from FIV-infected cats suppress T helper cells in vivo and that blocking GARP or TGFb eliminates this suppression. These data suggest that GARP is expressed in complex with TGFb on the surface of activated Treg cells and plays an important role in TGFb+ Treg-mediated T cell immune suppression during lentivirus infection. PMID:23373523

Twin-mediated crystal growth: an enigma resolved

PubMed Central

Shahani, Ashwin J.; Gulsoy, E. Begum; Poulsen, Stefan O.; Xiao, Xianghui; Voorhees, Peter W.

2016-01-01

During crystal growth, faceted interfaces may be perturbed by defects, leading to a rich variety of polycrystalline growth forms. One such defect is the coherent Σ3 {111} twin boundary, which is widely known to catalyze crystal growth. These defects have a profound effect on the properties of many materials: for example, electron-hole recombination rates strongly depend on the character of the twin boundaries in polycrystalline Si photovoltaic cells. However, the morphology of the twinned interface during growth has long been a mystery due to the lack of four-dimensional (i.e., space and time resolved) experiments. Many controversial mechanisms have been proposed for this process, most of which lack experimental verification. Here, we probe the real-time interfacial dynamics of polycrystalline Si particles growing from an Al-Si-Cu liquid via synchrotron-based X-ray tomography. Our novel analysis of the time evolution of the interfacial normals allows us to quantify unambiguously the habit plane and grain boundary orientations during growth. This, when combined with direct measurements of the interfacial morphology provide the first confirmation of twin-mediated growth, proposed over 50 years ago. Using the insights provided by these experiments, we have developed a unified picture of the phenomena responsible for the dynamics of faceted Si growth. PMID:27346073

Twin-mediated crystal growth: an enigma resolved

NASA Astrophysics Data System (ADS)

Shahani, Ashwin J.; Gulsoy, E. Begum; Poulsen, Stefan O.; Xiao, Xianghui; Voorhees, Peter W.

2016-06-01

During crystal growth, faceted interfaces may be perturbed by defects, leading to a rich variety of polycrystalline growth forms. One such defect is the coherent Σ3 {111} twin boundary, which is widely known to catalyze crystal growth. These defects have a profound effect on the properties of many materials: for example, electron-hole recombination rates strongly depend on the character of the twin boundaries in polycrystalline Si photovoltaic cells. However, the morphology of the twinned interface during growth has long been a mystery due to the lack of four-dimensional (i.e., space and time resolved) experiments. Many controversial mechanisms have been proposed for this process, most of which lack experimental verification. Here, we probe the real-time interfacial dynamics of polycrystalline Si particles growing from an Al-Si-Cu liquid via synchrotron-based X-ray tomography. Our novel analysis of the time evolution of the interfacial normals allows us to quantify unambiguously the habit plane and grain boundary orientations during growth. This, when combined with direct measurements of the interfacial morphology provide the first confirmation of twin-mediated growth, proposed over 50 years ago. Using the insights provided by these experiments, we have developed a unified picture of the phenomena responsible for the dynamics of faceted Si growth.

14-3-3 sigma and 14-3-3 zeta plays an opposite role in cell growth inhibition mediated by transforming growth factor-beta 1.

PubMed

Hong, Hye-Young; Jeon, Woo-Kwang; Bae, Eun-Jin; Kim, Shin-Tae; Lee, Ho-Jae; Kim, Seong-Jin; Kim, Byung-Chul

2010-03-01

The expression of 14-3-3 proteins is dysregulated in various types of cancer. This study was undertaken to investigate the effects of 14-3-3 zeta and 14-3-3 sigma on cell growth inhibition mediated by transforming growth factor-beta 1 (TGF-beta1). Mouse mammary epithelial cells (Eph4) that are transformed with oncogenic c-H-Ras (EpRas) and no longer sensitive to TGF-beta1-mediated growth inhibition displayed increased expression of 14-3-3 zeta and decreased expression of 14-3-3 sigma compared with parental Eph4 cells. Using small interfering RNA-mediated knockdown and overexpression of 14-3-3 sigma or 14-3-3 zeta, we showed that 14-3-3 sigma is required for TGF-beta1-mediated growth inhibition whereas 14-3-3 zeta negatively modulates this growth inhibitory response. Notably, overexpression of 14-3-3 zeta increased the level of Smad3 protein that is phosphorylated at linker regions and cannot mediate the TGF-beta1 growth inhibitory response. Consistent with this finding, mutation of the 14-3-3 zeta phosphorylation sites in Smad3 markedly reduced the 14-3-3 zeta-mediated inhibition of TGF-beta1-induced p15 promoter-reporter activity and cell cycle arrest, suggesting that these residues are critical targets of 14-3-3 zeta in the suppression of TGF-beta1-mediated growth. Taken together, our findings indicate that dysregulation of 14-3-3 sigma or 14-3-3 zeta contributes to TGF-beta1 resistance in cancer cells.

Regulatory elements involved in tax-mediated transactivation of the HTLV-I LTR.

PubMed

Seeler, J S; Muchardt, C; Podar, M; Gaynor, R B

1993-10-01

HTLV-I is the etiologic agent of adult T-cell leukemia. In this study, we investigated the regulatory elements and cellular transcription factors which function in modulating HTLV-I gene expression in response to the viral transactivator protein, tax. Transfection experiments into Jurkat cells of a variety of site-directed mutants in the HTLV-1 LTR indicated that each of the three motifs A, B, and C within the 21-bp repeats, the binding sites for the Ets family of proteins, and the TATA box all influenced the degree of tax-mediated activation. Tax is also able to activate gene expression of other viral and cellular promoters. Tax activation of the IL-2 receptor and the HIV-1 LTR is mediated through NF-kappa B motifs. Interestingly, sequences in the 21-bp repeat B and C motifs contain significant homology with NF-kappa B regulatory elements. We demonstrated that an NF-kappa B binding protein, PRDII-BF1, but not the rel protein, bound to the B and C motifs in the 21-bp repeat. PRDII-BF1 was also able to stimulate activation of HTLV-I gene expression by tax. The role of the Ets proteins on modulating tax activation was also studied. Ets 1 but not Ets 2 was capable of increasing the degree of tax activation of the HTLV-I LTR. These results suggest that tax activates gene expression by either direct or indirect interaction with several cellular transcription factors that bind to the HTLV-I LTR.

Neuropilin 1 deficiency on CD4+Foxp3+ regulatory T cells impairs mouse melanoma growth

PubMed Central

Hutzler, Marina; Abel, Simone; Alter, Christina; Stockmann, Christian; Kliche, Stefanie; Albert, Juliane; Sparwasser, Tim; Sakaguchi, Shimon; Westendorf, Astrid M.; Schadendorf, Dirk; Buer, Jan; Helfrich, Iris

2012-01-01

Infiltration of Foxp3+ regulatory T (T reg) cells is considered to be a critical step during tumor development and progression. T reg cells supposedly suppress locally an effective anti-tumor immune response within tumor tissues, although the precise mechanism by which T reg cells infiltrate the tumor is still unclear. We provide evidence that Neuropilin 1 (Nrp-1), highly expressed by Foxp3+ T reg cells, regulates the immunological anti-tumor control by guiding T reg cells into the tumor in response to tumor-derived vascular endothelial growth factor (VEGF). We demonstrate for the first time that T cell–specific ablation of Nrp-1 expression results in a significant breakdown in tumor immune escape in various transplantation models and in a spontaneous, endogenously driven melanoma model associated with strongly reduced tumor growth and prolonged tumor-free survival. Strikingly, numbers of tumor-infiltrating Foxp3+ T reg cells were significantly reduced accompanied by enhanced activation of CD8+ T cells within tumors of T cell–specific Nrp-1–deficient mice. This phenotype can be reversed by adoptive transfer of Nrp-1+ T reg cells from wild-type mice. Thus, our data strongly suggest that Nrp-1 acts as a key mediator of Foxp3+ T reg cell infiltration into the tumor site resulting in a dampened anti-tumor immune response and enhanced tumor progression. PMID:23045606

Hepatic carcinoma-associated fibroblasts induce IDO-producing regulatory dendritic cells through IL-6-mediated STAT3 activation

PubMed Central

Cheng, J-t; Deng, Y-n; Yi, H-m; Wang, G-y; Fu, B-s; Chen, W-j; Liu, W; Tai, Y; Peng, Y-w; Zhang, Q

2016-01-01

Although carcinoma-associated fibroblasts (CAFs) in tumor microenvironments have a critical role in immune cell modulation, their effects on the generation of regulatory dendritic cells (DCs) are still unclear. In this study, we initially show that CAFs derived from hepatocellular carcinoma (HCC) tumors facilitate the generation of regulatory DCs, which are characterized by low expression of costimulatory molecules, high suppressive cytokines production and enhanced regulation of immune responses, including T-cell proliferation impairment and promotion of regulatory T-cell (Treg) expansion via indoleamine 2,3-dioxygenase (IDO) upregulation. Our findings also indicate that STAT3 activation in DCs, as mediated by CAF-derived interleukin (IL)-6, is essential to IDO production. Moreover, IDO inhibitor, STAT3 and IL-6 blocking antibodies can reverse this hepatic CAF-DC regulatory function. Therefore, our results provide new insights into the mechanisms by which CAFs induce tumor immune escape as well as a novel cancer immunotherapeutic approach (for example, targeting CAFs, IDO or IL-6). PMID:26900950

Sheep skeletal muscle transcriptome analysis reveals muscle growth regulatory lncRNAs.

PubMed

Chao, Tianle; Ji, Zhibin; Hou, Lei; Wang, Jin; Zhang, Chunlan; Wang, Guizhi; Wang, Jianmin

2018-01-01

As widely distributed domestic animals, sheep are an important species and the source of mutton. In this study, we aimed to evaluate the regulatory lncRNAs associated with muscle growth and development between high production mutton sheep (Dorper sheep and Qianhua Mutton Merino sheep) and low production mutton sheep (Small-tailed Han sheep). In total, 39 lncRNAs were found to be differentially expressed. Using co-expression analysis and functional annotation, 1,206 co-expression interactions were found between 32 lncRNAs and 369 genes, and 29 of these lncRNAs were found to be associated with muscle development, metabolism, cell proliferation and apoptosis. lncRNA-mRNA interactions revealed 6 lncRNAs as hub lncRNAs. Moreover, three lncRNAs and their associated co-expressed genes were demonstrated by cis-regulatory gene analyses, and we also found a potential regulatory relationship between the pseudogene lncRNA LOC101121401 and its parent gene FTH1. This study provides a genome-wide resolution of lncRNA and mRNA regulation in muscles from mutton sheep.

Sheep skeletal muscle transcriptome analysis reveals muscle growth regulatory lncRNAs

PubMed Central

Chao, Tianle; Ji, Zhibin; Hou, Lei; Wang, Jin; Zhang, Chunlan

2018-01-01

As widely distributed domestic animals, sheep are an important species and the source of mutton. In this study, we aimed to evaluate the regulatory lncRNAs associated with muscle growth and development between high production mutton sheep (Dorper sheep and Qianhua Mutton Merino sheep) and low production mutton sheep (Small-tailed Han sheep). In total, 39 lncRNAs were found to be differentially expressed. Using co-expression analysis and functional annotation, 1,206 co-expression interactions were found between 32 lncRNAs and 369 genes, and 29 of these lncRNAs were found to be associated with muscle development, metabolism, cell proliferation and apoptosis. lncRNA–mRNA interactions revealed 6 lncRNAs as hub lncRNAs. Moreover, three lncRNAs and their associated co-expressed genes were demonstrated by cis-regulatory gene analyses, and we also found a potential regulatory relationship between the pseudogene lncRNA LOC101121401 and its parent gene FTH1. This study provides a genome-wide resolution of lncRNA and mRNA regulation in muscles from mutton sheep. PMID:29666768

Modifications to the algal growth inhibition test for use as a regulatory assay

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geis, S.W.; Fleming, K.L.; Korthals, E.T.

2000-01-01

Biological assays using aquatic invertebrates and fish do not necessarily predict protection levels for primary producers such as algae and aquatic macrophytes. State regulatory programs may not be protecting the environment from many phytotoxic compounds. Recent modifications of the US Environmental Protection Agency's algal test were evaluated for their potential use as a regulatory assay. Primary goals of this investigation were to downsize the algal assay and to evaluate various methods of automation. Disposable microplates with 2-ml sample wells were evaluated as an alternative testing chamber for the 96-h growth inhibition test with Raphidocelis subcapitata (formerly known as Selenastrum capricornutum).more » The authors compared the standardized Erlenmeyer {reg_sign} flask test to the microplate test using CuCl{sub 2}, NaCl, phenol, ZnCl{sub 2}, and a surfactant. They noted improved control performance with the microplate test, whereas median inhibitory concentration values were similar for both methods. Other procedures they addressed included the use of EDTA, filtration of samples, and the effect of colored samples on algal growth. They also evaluated growth estimates by comparing manual cell counting to more automated growth estimates using fluorescence and absorbance endpoints. The use of fluorescence and absorbance measurements demonstrated reductions in replicate variability over manual counting and may offer time-saving alternatives for laboratory analysts.« less

LPS-treated bone marrow-derived dendritic cells induce immune tolerance through modulating differentiation of CD4+ regulatory T cell subpopulations mediated by 3G11 and CD127.

PubMed

Zhou, Fang; Zhang, Guang-Xian; Rostami, Abdolmohamad

2017-06-01

Intravenous transfer of LPS-treated bone marrow-derived dendritic cells blocks development of autoimmunity induced by CD4 + T cells in vivo. However, cellular mechanisms of dendritic cell-mediated immune tolerance have not yet been fully elucidated. Here, we report that there are two new subpopulations of CD4 + CD25 + FoxP3 + GITR + regulatory T cells (CD127 + 3G11 + and CD127 + 3G11 - cells). LPS-treated dendritic cells facilitate development of CD4 + CD127 + 3G11 - regulatory T cells but inhibit that of CD4 + CD127 + 3G11 + regulatory T cells. LPS-induced tolerogenic dendritic cells may cause immune tolerance through modulating balance of different subsets of CD4 + regulatory T cells mediated by CD127 and 3G11. Our results imply a new potential cellular mechanism of dendritic cell-mediated immune tolerance.

Control of regulatory T cell lineage commitment and maintenance.

PubMed

Josefowicz, Steven Z; Rudensky, Alexander

2009-05-01

Foxp3-expressing regulatory T (Treg) cells suppress pathology mediated by immune responses against self and foreign antigens and commensal microorganisms. Sustained expression of the transcription factor Foxp3, a key distinguishing feature of Treg cells, is required for their differentiation and suppressor function. In addition, Foxp3 expression prevents deviation of Treg cells into effector T cell lineages and confers dependence of Treg cell survival and expansion on growth factors, foremost interleukin-2, provided by activated effector T cells. In this review we discuss Treg cell differentiation and maintenance with a particular emphasis on molecular regulation of Foxp3 expression, arguably a key to mechanistic understanding of biology of regulatory T cells.

Underpotential deposition-mediated layer-by-layer growth of thin films

DOEpatents

Wang, Jia Xu; Adzic, Radoslav R.

2017-06-27

A method of depositing contiguous, conformal submonolayer-to-multilayer thin films with atomic-level control is described. The process involves electrochemically exchanging a mediating element on a substrate with a noble metal film by alternatingly sweeping potential in forward and reverse directions for a predetermined number of times in an electrochemical cell. By cycling the applied voltage between the bulk deposition potential for the mediating element and the material to be deposited, repeated desorption/adsorption of the mediating element during each potential cycle can be used to precisely control film growth on a layer-by-layer basis.

Why are people with high self-control happier? The effect of trait self-control on happiness as mediated by regulatory focus

PubMed Central

Cheung, Tracy T. L.; Gillebaart, Marleen; Kroese, Floor; De Ridder, Denise

2014-01-01

Background: While self-control has often been related to positive outcomes in life such as higher academic achievements and better health, recent insights reveal that people with high trait self-control (TSC) may even experience greater life satisfaction or happiness. Objective: The current study further scrutinizes this potential association between TSC and happiness, and examines how regulatory focus, defined as the way people frame and direct their goal pursuit strategies, plays a role in this relationship. Accordingly, the present study examines the mediating role of regulatory-focus (promotion and prevention focus) on the relationship between TSC and happiness. Method: Data was collected from 545 individuals (65.9% female, Mage = 27.52 years) regarding their TSC, regulatory focus, and happiness. Results: Mediation analyses demonstrate that TSC positively predicts happiness, while this effect was partially mediated by relatively more promotion focus and less prevention focus. Conclusion: Results suggest that people with higher TSC are happier possibly because they are: (1) more promotion-focused on acquiring positive gains thereby facilitating more approach-oriented behaviors, and (2) less prevention-focused on avoiding losses thereby reducing avoidance-oriented behaviors. These findings are relevant for topical scientific debates regarding the underlying mechanisms of self-control regarding initiatory and inhibitory behaviors. PMID:25071683

Curcumin Inhibits CD4+ T Cell Activation, but Augments CD69 Expression and TGF-β1-Mediated Generation of Regulatory T Cells at Late Phase

PubMed Central

Kim, Girak; Jang, Mi Seon; Son, Young Min; Seo, Min Ji; Ji, Sang Yun; Han, Seung Hyun; Jung, In Duk; Park, Yeong-Min; Jung, Hyun Jung; Yun, Cheol-Heui

2013-01-01

Background Curcumin is a promising candidate for a natural medicinal agent to treat chronic inflammatory diseases. Although CD4+ T cells have been implicated in the pathogenesis of chronic inflammation, whether curcumin directly regulates CD4+ T cells has not been definitively established. Here, we showed curcumin-mediated regulation of CD2/CD3/CD28-initiated CD4+ T cell activation in vitro. Methodology/Principal Findings Primary human CD4+ T cells were stimulated with anti-CD2/CD3/CD28 antibody-coated beads as an in vitro surrogate system for antigen presenting cell-T cell interaction and treated with curcumin. We found that curcumin suppresses CD2/CD3/CD28-initiated CD4+ T cell activation by inhibiting cell proliferation, differentiation and cytokine production. On the other hand, curcumin attenuated the spontaneous decline of CD69 expression and indirectly increased expression of CCR7, L-selectin and Transforming growth factor-β1 (TGF-β1) at the late phase of CD2/CD3/CD28-initiated T cell activation. Curcumin-mediated up-regulation of CD69 at late phase was associated with ERK1/2 signaling. Furthermore, TGF-β1 was involved in curcumin-mediated regulation of T cell activation and late-phase generation of regulatory T cells. Conclusions/Significance Curcumin not merely blocks, but regulates CD2/CD3/CD28-initiated CD4+ T cell activation by augmenting CD69, CCR7, L-selectin and TGF-β1 expression followed by regulatory T cell generation. These results suggest that curcumin could directly reduce T cell-dependent inflammatory stress by modulating CD4+ T cell activation at multiple levels. PMID:23658623

Advantages of mixing bioinformatics and visualization approaches for analyzing sRNA-mediated regulatory bacterial networks

PubMed Central

Bourqui, Romain; Benchimol, William; Gaspin, Christine; Sirand-Pugnet, Pascal; Uricaru, Raluca; Dutour, Isabelle

2015-01-01

The revolution in high-throughput sequencing technologies has enabled the acquisition of gigabytes of RNA sequences in many different conditions and has highlighted an unexpected number of small RNAs (sRNAs) in bacteria. Ongoing exploitation of these data enables numerous applications for investigating bacterial transacting sRNA-mediated regulation networks. Focusing on sRNAs that regulate mRNA translation in trans, recent works have noted several sRNA-based regulatory pathways that are essential for key cellular processes. Although the number of known bacterial sRNAs is increasing, the experimental validation of their interactions with mRNA targets remains challenging and involves expensive and time-consuming experimental strategies. Hence, bioinformatics is crucial for selecting and prioritizing candidates before designing any experimental work. However, current software for target prediction produces a prohibitive number of candidates because of the lack of biological knowledge regarding the rules governing sRNA–mRNA interactions. Therefore, there is a real need to develop new approaches to help biologists focus on the most promising predicted sRNA–mRNA interactions. In this perspective, this review aims at presenting the advantages of mixing bioinformatics and visualization approaches for analyzing predicted sRNA-mediated regulatory bacterial networks. PMID:25477348

Advantages of mixing bioinformatics and visualization approaches for analyzing sRNA-mediated regulatory bacterial networks.

PubMed

Thébault, Patricia; Bourqui, Romain; Benchimol, William; Gaspin, Christine; Sirand-Pugnet, Pascal; Uricaru, Raluca; Dutour, Isabelle

2015-09-01

The revolution in high-throughput sequencing technologies has enabled the acquisition of gigabytes of RNA sequences in many different conditions and has highlighted an unexpected number of small RNAs (sRNAs) in bacteria. Ongoing exploitation of these data enables numerous applications for investigating bacterial transacting sRNA-mediated regulation networks. Focusing on sRNAs that regulate mRNA translation in trans, recent works have noted several sRNA-based regulatory pathways that are essential for key cellular processes. Although the number of known bacterial sRNAs is increasing, the experimental validation of their interactions with mRNA targets remains challenging and involves expensive and time-consuming experimental strategies. Hence, bioinformatics is crucial for selecting and prioritizing candidates before designing any experimental work. However, current software for target prediction produces a prohibitive number of candidates because of the lack of biological knowledge regarding the rules governing sRNA-mRNA interactions. Therefore, there is a real need to develop new approaches to help biologists focus on the most promising predicted sRNA-mRNA interactions. In this perspective, this review aims at presenting the advantages of mixing bioinformatics and visualization approaches for analyzing predicted sRNA-mediated regulatory bacterial networks. © The Author 2014. Published by Oxford University Press.

Fibroblast growth factor receptor mediates fibroblast-dependent growth in EMMPRIN-depleted head and neck cancer tumor cells.

PubMed

Liu, Zhiyong; Hartman, Yolanda E; Warram, Jason M; Knowles, Joseph A; Sweeny, Larissa; Zhou, Tong; Rosenthal, Eben L

2011-08-01

Head and neck squamous cell carcinoma tumors (HNSCC) contain a dense fibrous stroma which is known to promote tumor growth, although the mechanism of stroma-mediated growth remains unclear. As dysplastic mucosal epithelium progresses to cancer, there is incremental overexpression of extracellular matrix metalloprotease inducer (EMMPRIN) which is associated with tumor growth and metastasis. Here, we present evidence that gain of EMMPRIN expression allows tumor growth to be less dependent on fibroblasts by modulating fibroblast growth factor receptor-2 (FGFR2) signaling. We show that silencing EMMPRIN in FaDu and SCC-5 HNSCC cell lines inhibits cell growth, but when EMMPRIN-silenced tumor cells were cocultured with fibroblasts or inoculated with fibroblasts into severe combined immunodeficient mice, the growth inhibition by silencing EMMPRIN was blunted by the presence of fibroblasts. Coculture experiments showed fibroblast-dependent tumor cell growth occurred via a paracrine signaling. Analysis of tumor gene expression revealed expression of FGFR2 was inversely related to EMMPRIN expression. To determine the role of FGFR2 signaling in EMMPRIN-silenced tumor cells, ligands and inhibitors of FGFR2 were assessed. Both FGF1 and FGF2 enhanced tumor growth in EMMPRIN-silenced cells compared with control vector-transfected cells, whereas inhibition of FGFR2 with blocking antibody or with a synthetic inhibitor (PD173074) inhibited tumor cell growth in fibroblast coculture, suggesting the importance of FGFR2 signaling in fibroblast-mediated tumor growth. Analysis of xenografted tumors revealed that EMMPRIN-silenced tumors had a larger stromal compartment compared with control. Taken together, these results suggest that EMMPRIN acquired during tumor progression promotes fibroblast-independent tumor growth.

Fibroblast growth factor receptor mediates fibroblast-dependent growth in EMMPRIN depleted head and neck cancer tumor cells

PubMed Central

Liu, Zhiyong; Hartman, Yolanda E.; Warram, Jason M.; Knowles, Joseph A.; Sweeny, Larrisa; Zhou, Tong; Rosenthal, Eben L.

2011-01-01

Head and neck squamous cell carcinoma tumors (HNSCC) contain a dense fibrous stroma which is known to promote tumor growth, although the mechanism of stroma mediated growth remains unclear. As dysplastic mucosal epithelium progresses to cancer there is incremental overexpression of extracellular matrix metalloprotease inducer (EMMPRIN) which is associated with tumor growth and metastasis. Here we present evidence that gain of EMMPRIN expression allows tumor growth to be less dependent on fibroblasts by modulating fibroblast growth factor receptor-2 (FGFR2) signaling. We show that silencing EMMPRIN in FaDu and SCC-5 HNSCC cell lines inhibits cell growth, but when EMMPRIN-silenced tumor cells were co-cultured with fibroblasts or inoculated with fibroblasts into SCID mice, the growth inhibition by silencing EMMPRIN was blunted by the presence of fibroblasts. Co-culture experiments demonstrated fibroblast-dependent tumor cell growth occurred via a paracrine signaling. Analysis of tumor gene expression revealed expression of FGFR2 was inversely related to EMMPRIN expression. To determine the role of FGFR2 signaling in EMMPRIN silenced tumor cells, ligands and inhibitors of FGFR2 were assessed. Both FGF1 and FGF2 enhanced tumor growth in EMMPRIN silenced cells compared to control vector transfected cells, while inhibition of FGFR2 with blocking antibody or with a synthetic inhibitor (PD173074) inhibited tumor cell growth in fibroblast co-culture, suggesting the importance of FGFR2 signaling in fibroblast mediated tumor growth. Analysis of xenografted tumors revealed EMMPRIN silenced tumors had a larger stromal compartment compared to control. Taken together, these results suggest that EMMPRIN acquired during tumor progression promotes fibroblast independent tumor growth. PMID:21665938

Microenvironmental cues enhance mesenchymal stem cell-mediated immunomodulation and regulatory T-cell expansion.

PubMed

Kadle, Rohini L; Abdou, Salma A; Villarreal-Ponce, Alvaro P; Soares, Marc A; Sultan, Darren L; David, Joshua A; Massie, Jonathan; Rifkin, William J; Rabbani, Piul; Ceradini, Daniel J

2018-01-01

Mesenchymal stem cells (MSCs) are known to both have powerful immunosuppressive properties and promote allograft tolerance. Determining the environmental oxygen tension and inflammatory conditions under which MSCs are optimally primed for this immunosuppressive function is essential to their utilization in promoting graft tolerance. Of particular interest is the mechanisms governing the interaction between MSCs and regulatory T cells (Tregs), which is relatively unknown. We performed our experiments utilizing rat bone marrow derived MSCs. We observed that priming MSCs in hypoxia promotes maintenance of stem-like characteristics, with greater expression of typical MSC cell-surface markers, increased proliferation, and maintenance of differentiation potential. Addition of autologous MSCs to CD4+/allogeneic endothelial cell (EC) co-culture increases regulatory T cell (Treg) proliferation, which is further enhanced when MSCs are primed in hypoxia. Furthermore, MSC-mediated Treg expansion does not require direct cell-cell contact. The expression of indolamine 2,3-dioxygenase, a mediator of MSC immunomodulation, increases when MSCs are primed in hypoxia, and inhibition of IDO significantly decreases the expansion of Tregs. Priming with inflammatory cytokines IFNγ and TNFα increases also expression of markers associated with MSC immunomodulatory function, but decreases MSC proliferation. The expression of IDO also increases when MSCs are primed with inflammatory cytokines. However, there is no increase in Treg expansion when MSCs are primed with IFNγ, suggesting an alternate mechanism for inflammatory-stimulated MSC immunomodulation. Overall, these results suggest that MSCs primed in hypoxia or inflammatory conditions are optimally primed for immunosuppressive function. These results provide a clearer picture of how to enhance MSC immunomodulation for clinical use.

Regulatory RNAs in Bacillus subtilis: a Gram-Positive Perspective on Bacterial RNA-Mediated Regulation of Gene Expression.

PubMed

Mars, Ruben A T; Nicolas, Pierre; Denham, Emma L; van Dijl, Jan Maarten

2016-12-01

Bacteria can employ widely diverse RNA molecules to regulate their gene expression. Such molecules include trans-acting small regulatory RNAs, antisense RNAs, and a variety of transcriptional attenuation mechanisms in the 5' untranslated region. Thus far, most regulatory RNA research has focused on Gram-negative bacteria, such as Escherichia coli and Salmonella. Hence, there is uncertainty about whether the resulting insights can be extrapolated directly to other bacteria, such as the Gram-positive soil bacterium Bacillus subtilis. A recent study identified 1,583 putative regulatory RNAs in B. subtilis, whose expression was assessed across 104 conditions. Here, we review the current understanding of RNA-based regulation in B. subtilis, and we categorize the newly identified putative regulatory RNAs on the basis of their conservation in other bacilli and the stability of their predicted secondary structures. Our present evaluation of the publicly available data indicates that RNA-mediated gene regulation in B. subtilis mostly involves elements at the 5' ends of mRNA molecules. These can include 5' secondary structure elements and metabolite-, tRNA-, or protein-binding sites. Importantly, sense-independent segments are identified as the most conserved and structured potential regulatory RNAs in B. subtilis. Altogether, the present survey provides many leads for the identification of new regulatory RNA functions in B. subtilis. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Regulatory RNAs in Bacillus subtilis: a Gram-Positive Perspective on Bacterial RNA-Mediated Regulation of Gene Expression

PubMed Central

Mars, Ruben A. T.; Nicolas, Pierre; Denham, Emma L.

2016-01-01

SUMMARY Bacteria can employ widely diverse RNA molecules to regulate their gene expression. Such molecules include trans-acting small regulatory RNAs, antisense RNAs, and a variety of transcriptional attenuation mechanisms in the 5′ untranslated region. Thus far, most regulatory RNA research has focused on Gram-negative bacteria, such as Escherichia coli and Salmonella. Hence, there is uncertainty about whether the resulting insights can be extrapolated directly to other bacteria, such as the Gram-positive soil bacterium Bacillus subtilis. A recent study identified 1,583 putative regulatory RNAs in B. subtilis, whose expression was assessed across 104 conditions. Here, we review the current understanding of RNA-based regulation in B. subtilis, and we categorize the newly identified putative regulatory RNAs on the basis of their conservation in other bacilli and the stability of their predicted secondary structures. Our present evaluation of the publicly available data indicates that RNA-mediated gene regulation in B. subtilis mostly involves elements at the 5′ ends of mRNA molecules. These can include 5′ secondary structure elements and metabolite-, tRNA-, or protein-binding sites. Importantly, sense-independent segments are identified as the most conserved and structured potential regulatory RNAs in B. subtilis. Altogether, the present survey provides many leads for the identification of new regulatory RNA functions in B. subtilis. PMID:27784798

Mediation Analysis in a Latent Growth Curve Modeling Framework

ERIC Educational Resources Information Center

von Soest, Tilmann; Hagtvet, Knut A.

2011-01-01

This article presents several longitudinal mediation models in the framework of latent growth curve modeling and provides a detailed account of how such models can be constructed. Logical and statistical challenges that might arise when such analyses are conducted are also discussed. Specifically, we discuss how the initial status (intercept) and…

Insulin-like growth factor-mediated muscle differentiation: collaboration between phosphatidylinositol 3-kinase-Akt-signaling pathways and myogenin.

PubMed

Tureckova, J; Wilson, E M; Cappalonga, J L; Rotwein, P

2001-10-19

The differentiation and maturation of skeletal muscle require interactions between signaling pathways activated by hormones and growth factors and an intrinsic regulatory network controlled by myogenic transcription factors. Insulin-like growth factors (IGFs) play key roles in muscle development in the embryo and in regeneration in the adult. To study mechanisms of IGF action in muscle, we developed a myogenic cell line that overexpresses IGF-binding protein-5. C2BP5 cells remain quiescent in low serum differentiation medium until the addition of IGF-I. Here we use this cell line to identify signaling pathways controlling IGF-mediated differentiation. Induction of myogenin by IGF-I and myotube formation were prevented by the phosphatidylinositol (PI) 3-kinase inhibitor, LY294002, even when included 2 days after growth factor addition, whereas expression of active PI 3-kinase could promote differentiation in the absence of IGF-I. Differentiation also was induced by myogenin but was blocked by LY294002. The differentiation-promoting effects of IGF-I were mimicked by a modified membrane-targeted inducible Akt-1 (iAkt), and iAkt was able to stimulate differentiation of C2 myoblasts and primary mouse myoblasts incubated with otherwise inhibitory concentrations of LY294002. These results show that an IGF-regulated PI 3-kinase-Akt pathway controls muscle differentiation by mechanisms acting both upstream and downstream of myogenin.

The Pollen Receptor Kinase LePRK2 Mediates Growth-Promoting Signals and Positively Regulates Pollen Germination and Tube Growth

USDA-ARS?s Scientific Manuscript database

In flowering plants, the process of pollen germination and tube growth is required for successful fertilization. A pollen receptor kinase from tomato, LePRK2, has been implicated in signaling during pollen germination and tube growth as well as in mediating pollen (tube)-pistil communication. Here w...

Deficient Activity in the Neural Systems That Mediate Self-regulatory Control in Bulimia Nervosa

PubMed Central

Marsh, Rachel; Steinglass, Joanna E.; Gerber, Andrew J.; O’Leary, Kara Graziano; Wang, Zhishun; Murphy, David; Walsh, B. Timothy; Peterson, Bradley S.

2009-01-01

Context Disturbances in neural systems that mediate voluntary self-regulatory processes may contribute to bulimia nervosa (BN) by releasing feeding behaviors from regulatory control. Objective To study the functional activity in neural circuits that subserve self-regulatory control in women with BN. Design We compared functional magnetic resonance imaging blood oxygenation level–dependent responses in patients with BN with healthy controls during performance of the Simon Spatial Incompatibility task. Setting University research institute. Participants Forty women: 20 patients with BN and 20 healthy control participants. Main Outcome Measure We used general linear modeling of Simon Spatial Incompatibility task–related activations to compare groups on their patterns of brain activation associated with the successful or unsuccessful engagement of self-regulatory control. Results Patients with BN responded more impulsively and made more errors on the task than did healthy controls; patients with the most severe symptoms made the most errors. During correct responding on incongruent trials, patients failed to activate frontostriatal circuits to the same degree as healthy controls in the left inferolateral prefrontal cortex (Brodmann area [BA] 45), bilateral inferior frontal gyrus (BA 44), lenticular and caudate nuclei, and anterior cingulate cortex (BA 24/32). Patients activated the dorsal anterior cingulate cortex (BA 32) more when making errors than when responding correctly. In contrast, healthy participants activated the anterior cingulate cortex more during correct than incorrect responses, and they activated the striatum more when responding incorrectly, likely reflecting an automatic response tendency that, in the absence of concomitant anterior cingulate cortex activity, produced incorrect responses. Conclusions Self-regulatory processes are impaired in women with BN, likely because of their failure to engage frontostriatal circuits appropriately. These

Sex steroids, the insulin-like growth factor regulatory system, and aging: implications for the management of older postmenopausal women.

PubMed

Rosen, C J; Glowacki, J; Craig, W

1998-01-01

Aging is associated with profound changes in the growth hormone/insulin-like growth factor (IGF) regulatory system. These include reductions in growth hormone, IGF-I, IGFBP3, and IGFBP-5 and an increase in IGFBP-4. These changes, coupled with rather marked declines in sex steroid production from both the ovary and adrenals may combine to have very deleterious effects on several organ systems in the postmenopausal woman. In particular, the prevalence of two very common diseases, osteoporosis and coronary artery disease, increase dramatically after the cessation of gonadal steroid production. The complex interrelationship between the IGF regulatory system and estrogens/androgens in the postmenopausal period may provide important clues as to the pathophysiology of both these disorders. In this paper, we begin to define the role of IGF-I (and its constituent IGF binding proteins) in skeletal and vascular tissue. Recent experimental data show the effects of estrogen on circulating and tissue IGFs in older individuals. Finally, estrogen replacement therapy affects the IGF regulatory system in postmenopausal women. Although conclusions from early studies remain somewhat preliminary, it is likely that the IGF regulatory system will be a prime target for future studies into the pathogenesis of several age and sex hormone related degenerative disorders.

Systematic comparison of the response properties of protein and RNA mediated gene regulatory motifs.

PubMed

Iyengar, Bharat Ravi; Pillai, Beena; Venkatesh, K V; Gadgil, Chetan J

2017-05-30

We present a framework enabling the dissection of the effects of motif structure (feedback or feedforward), the nature of the controller (RNA or protein), and the regulation mode (transcriptional, post-transcriptional or translational) on the response to a step change in the input. We have used a common model framework for gene expression where both motif structures have an activating input and repressing regulator, with the same set of parameters, to enable a comparison of the responses. We studied the global sensitivity of the system properties, such as steady-state gain, overshoot, peak time, and peak duration, to parameters. We find that, in all motifs, overshoot correlated negatively whereas peak duration varied concavely with peak time. Differences in the other system properties were found to be mainly dependent on the nature of the controller rather than the motif structure. Protein mediated motifs showed a higher degree of adaptation i.e. a tendency to return to baseline levels; in particular, feedforward motifs exhibited perfect adaptation. RNA mediated motifs had a mild regulatory effect; they also exhibited a lower peaking tendency and mean overshoot. Protein mediated feedforward motifs showed higher overshoot and lower peak time compared to the corresponding feedback motifs.

Microenvironmental cues enhance mesenchymal stem cell-mediated immunomodulation and regulatory T-cell expansion

PubMed Central

Abdou, Salma A.; Villarreal-Ponce, Alvaro P.; Soares, Marc A.; Sultan, Darren L.; David, Joshua A.; Massie, Jonathan; Rabbani, Piul

2018-01-01

Mesenchymal stem cells (MSCs) are known to both have powerful immunosuppressive properties and promote allograft tolerance. Determining the environmental oxygen tension and inflammatory conditions under which MSCs are optimally primed for this immunosuppressive function is essential to their utilization in promoting graft tolerance. Of particular interest is the mechanisms governing the interaction between MSCs and regulatory T cells (Tregs), which is relatively unknown. We performed our experiments utilizing rat bone marrow derived MSCs. We observed that priming MSCs in hypoxia promotes maintenance of stem-like characteristics, with greater expression of typical MSC cell-surface markers, increased proliferation, and maintenance of differentiation potential. Addition of autologous MSCs to CD4+/allogeneic endothelial cell (EC) co-culture increases regulatory T cell (Treg) proliferation, which is further enhanced when MSCs are primed in hypoxia. Furthermore, MSC-mediated Treg expansion does not require direct cell-cell contact. The expression of indolamine 2,3-dioxygenase, a mediator of MSC immunomodulation, increases when MSCs are primed in hypoxia, and inhibition of IDO significantly decreases the expansion of Tregs. Priming with inflammatory cytokines IFNγ and TNFα increases also expression of markers associated with MSC immunomodulatory function, but decreases MSC proliferation. The expression of IDO also increases when MSCs are primed with inflammatory cytokines. However, there is no increase in Treg expansion when MSCs are primed with IFNγ, suggesting an alternate mechanism for inflammatory-stimulated MSC immunomodulation. Overall, these results suggest that MSCs primed in hypoxia or inflammatory conditions are optimally primed for immunosuppressive function. These results provide a clearer picture of how to enhance MSC immunomodulation for clinical use. PMID:29513756

Small regulatory RNA-induced growth rate heterogeneity of Bacillus subtilis.

PubMed

Mars, Ruben A T; Nicolas, Pierre; Ciccolini, Mariano; Reilman, Ewoud; Reder, Alexander; Schaffer, Marc; Mäder, Ulrike; Völker, Uwe; van Dijl, Jan Maarten; Denham, Emma L

2015-03-01

Isogenic bacterial populations can consist of cells displaying heterogeneous physiological traits. Small regulatory RNAs (sRNAs) could affect this heterogeneity since they act by fine-tuning mRNA or protein levels to coordinate the appropriate cellular behavior. Here we show that the sRNA RnaC/S1022 from the Gram-positive bacterium Bacillus subtilis can suppress exponential growth by modulation of the transcriptional regulator AbrB. Specifically, the post-transcriptional abrB-RnaC/S1022 interaction allows B. subtilis to increase the cell-to-cell variation in AbrB protein levels, despite strong negative autoregulation of the abrB promoter. This behavior is consistent with existing mathematical models of sRNA action, thus suggesting that induction of protein expression noise could be a new general aspect of sRNA regulation. Importantly, we show that the sRNA-induced diversity in AbrB levels generates heterogeneity in growth rates during the exponential growth phase. Based on these findings, we hypothesize that the resulting subpopulations of fast- and slow-growing B. subtilis cells reflect a bet-hedging strategy for enhanced survival of unfavorable conditions.

Posttraumatic growth and parental bonding in young adults of parents with physical disabilites: testing mediation model of resilience.

PubMed

Li, Yuli; Xing, Aihong; Chen, Xiaoyun; Lou, Fenglan; Cao, Fenglin

2018-07-01

Positive parent-child relationships are associated with positive youth development, but little is known about the relationships between parental bonding, resilience, and posttraumatic growth, which is positive change resulting from the struggle with trauma. This study examined a mediation model among 119 female young adults with disabled parents. The model included resilience as a mediator of the relationship between the paternal Care and posttraumatic growth. The results revealed that resilience did mediate the relationship between the paternal Care and posttraumatic growth. The findings indicate that paternal Care helps to foster female young adults' resilience, which benefits their growth after suffering adversities.

Membrane-bound Dickkopf-1 in Foxp3+ regulatory T cells suppresses T-cell-mediated autoimmune colitis.

PubMed

Chae, Wook-Jin; Park, Jong-Hyun; Henegariu, Octavian; Yilmaz, Saliha; Hao, Liming; Bothwell, Alfred L M

2017-10-01

Induction of tolerance is a key mechanism to maintain or to restore immunological homeostasis. Here we show that Foxp3 + regulatory T (Treg) cells use Dickkopf-1 (DKK-1) to regulate T-cell-mediated tolerance in the T-cell-mediated autoimmune colitis model. Treg cells from DKK-1 hypomorphic doubleridge mice failed to control CD4 + T-cell proliferation, resulting in CD4 T-cell-mediated autoimmune colitis. Thymus-derived Treg cells showed a robust expression of DKK-1 but not in naive or effector CD4 T cells. DKK-1 expression in Foxp3 + Treg cells was further increased upon T-cell receptor stimulation in vitro and in vivo. Interestingly, Foxp3 + Treg cells expressed DKK-1 in the cell membrane and the functional inhibition of DKK-1 using DKK-1 monoclonal antibody abrogated the suppressor function of Foxp3 + Treg cells. DKK-1 expression was dependent on de novo protein synthesis and regulated by the mitogen-activated protein kinase pathway but not by the canonical Wnt pathway. Taken together, our results highlight membrane-bound DKK-1 as a novel Treg-derived mediator to maintain immunological tolerance in T-cell-mediated autoimmune colitis. © 2017 The Authors. Immunology Published by John Wiley & Sons Ltd.

Essential Cell-Autonomous Role for Interferon (IFN) Regulatory Factor 1 in IFN-γ-Mediated Inhibition of Norovirus Replication in Macrophages

PubMed Central

Maloney, Nicole S.; Thackray, Larissa B.; Goel, Gautam; Hwang, Seungmin; Duan, Erning; Vachharajani, Punit; Xavier, Ramnik

2012-01-01

Noroviruses (NVs) cause the majority of cases of epidemic nonbacterial gastroenteritis worldwide and contribute to endemic enteric disease. However, the molecular mechanisms responsible for immune control of their replication are not completely understood. Here we report that the transcription factor interferon regulatory factor 1 (IRF-1) is required for control of murine NV (MNV) replication and pathogenesis in vivo. This led us to studies documenting a cell-autonomous role for IRF-1 in gamma interferon (IFN-γ)-mediated inhibition of MNV replication in primary macrophages. This role of IRF-1 in the inhibition of MNV replication by IFN-γ is independent of IFN-αβ signaling. While the signal transducer and activator of transcription STAT-1 was also required for IFN-γ-mediated inhibition of MNV replication in vitro, class II transactivator (CIITA), interferon regulatory factor 3 (IRF-3), and interferon regulatory factor 7 (IRF-7) were not required. We therefore hypothesized that there must be a subset of IFN-stimulated genes (ISGs) regulated by IFN-γ in a manner dependent only on STAT-1 and IRF-1. Analysis of transcriptional profiles of macrophages lacking various transcription factors confirmed this hypothesis. These studies identify a key role for IRF-1 in IFN-γ-dependent control of norovirus infection in mice and macrophages. PMID:22973039

Inhibition of phosphoantigen-mediated gammadelta T-cell proliferation by CD4+ CD25+ FoxP3+ regulatory T cells.

PubMed

Kunzmann, Volker; Kimmel, Brigitte; Herrmann, Thomas; Einsele, Hermann; Wilhelm, Martin

2009-02-01

Tumour growth promotes the expansion of CD4(+) CD25(+) FoxP3(+) regulatory T cells (Tregs) which suppress various arms of immune responses and might therefore contribute to tumour immunosurveillance. In this study, we found an inverse correlation between circulating Treg frequencies and phosphoantigen-induced gammadelta T-cell proliferation in cancer patients, which prompted us to address the role of Tregs in controlling the gammadelta T-cell arm of innate immune responses. In vitro, human Treg-peripheral blood mononuclear cell (PBMC) co-cultures strongly inhibited phosphoantigen-induced proliferation of gammadelta T cells and depletion of Tregs restored the impaired phosphoantigen-induced gammadelta T-cell proliferation of cancer patients. Tregs did not suppress other effector functions of gammadelta T cells such as cytokine production or cytotoxicity. Our experiments indicate that Tregs do not mediate their suppressive activity via a cell-cell contact-dependent mechanism, but rather secrete a soluble non-proteinaceous factor, which is independent of known soluble factors interacting with amino acid depletion (e.g. arginase-diminished arginine and indolamine 2,3-dioxygenase-diminished tryptophan) or nitric oxide (NO) production. However, the proliferative activity of alphabeta T cells was not affected by this cell-cell contact-independent suppressive activity induced by Tregs. In conclusion, these findings indicate a potential new mechanism by which Tregs can specifically suppress gammadelta T cells and highlight the strategy of combining Treg inhibition with subsequent gammadelta T-cell activation to enhance gammadelta T cell-mediated immunotherapy.

GATA3 acts upstream of FOXA1 in mediating ESR1 binding by shaping enhancer accessibility.

PubMed

Theodorou, Vasiliki; Stark, Rory; Menon, Suraj; Carroll, Jason S

2013-01-01

Estrogen receptor (ESR1) drives growth in the majority of human breast cancers by binding to regulatory elements and inducing transcription events that promote tumor growth. Differences in enhancer occupancy by ESR1 contribute to the diverse expression profiles and clinical outcome observed in breast cancer patients. GATA3 is an ESR1-cooperating transcription factor mutated in breast tumors; however, its genomic properties are not fully defined. In order to investigate the composition of enhancers involved in estrogen-induced transcription and the potential role of GATA3, we performed extensive ChIP-sequencing in unstimulated breast cancer cells and following estrogen treatment. We find that GATA3 is pivotal in mediating enhancer accessibility at regulatory regions involved in ESR1-mediated transcription. GATA3 silencing resulted in a global redistribution of cofactors and active histone marks prior to estrogen stimulation. These global genomic changes altered the ESR1-binding profile that subsequently occurred following estrogen, with events exhibiting both loss and gain in binding affinity, implying a GATA3-mediated redistribution of ESR1 binding. The GATA3-mediated redistributed ESR1 profile correlated with changes in gene expression, suggestive of its functionality. Chromatin loops at the TFF locus involving ESR1-bound enhancers occurred independently of ESR1 when GATA3 was silenced, indicating that GATA3, when present on the chromatin, may serve as a licensing factor for estrogen-ESR1-mediated interactions between cis-regulatory elements. Together, these experiments suggest that GATA3 directly impacts ESR1 enhancer accessibility, and may potentially explain the contribution of mutant-GATA3 in the heterogeneity of ESR1+ breast cancer.

GATA3 acts upstream of FOXA1 in mediating ESR1 binding by shaping enhancer accessibility

PubMed Central

Theodorou, Vasiliki; Stark, Rory; Menon, Suraj; Carroll, Jason S.

2013-01-01

Estrogen receptor (ESR1) drives growth in the majority of human breast cancers by binding to regulatory elements and inducing transcription events that promote tumor growth. Differences in enhancer occupancy by ESR1 contribute to the diverse expression profiles and clinical outcome observed in breast cancer patients. GATA3 is an ESR1-cooperating transcription factor mutated in breast tumors; however, its genomic properties are not fully defined. In order to investigate the composition of enhancers involved in estrogen-induced transcription and the potential role of GATA3, we performed extensive ChIP-sequencing in unstimulated breast cancer cells and following estrogen treatment. We find that GATA3 is pivotal in mediating enhancer accessibility at regulatory regions involved in ESR1-mediated transcription. GATA3 silencing resulted in a global redistribution of cofactors and active histone marks prior to estrogen stimulation. These global genomic changes altered the ESR1-binding profile that subsequently occurred following estrogen, with events exhibiting both loss and gain in binding affinity, implying a GATA3-mediated redistribution of ESR1 binding. The GATA3-mediated redistributed ESR1 profile correlated with changes in gene expression, suggestive of its functionality. Chromatin loops at the TFF locus involving ESR1-bound enhancers occurred independently of ESR1 when GATA3 was silenced, indicating that GATA3, when present on the chromatin, may serve as a licensing factor for estrogen–ESR1-mediated interactions between cis-regulatory elements. Together, these experiments suggest that GATA3 directly impacts ESR1 enhancer accessibility, and may potentially explain the contribution of mutant-GATA3 in the heterogeneity of ESR1+ breast cancer. PMID:23172872

Repeated cis-regulatory tuning of a metabolic bottleneck gene during evolution.

PubMed

Kuang, Meihua Christina; Kominek, Jacek; Alexander, William G; Cheng, Jan-Fang; Wrobel, Russell L; Hittinger, Chris Todd

2018-05-21

Repeated evolutionary events imply underlying genetic constraints that can make evolutionary mechanisms predictable. Morphological traits are thought to evolve frequently through cis-regulatory changes because these mechanisms bypass constraints in pleiotropic genes that are reused during development. In contrast, the constraints acting on metabolic traits during evolution are less well studied. Here we show how a metabolic bottleneck gene has repeatedly adopted similar cis-regulatory solutions during evolution, likely due to its pleiotropic role integrating flux from multiple metabolic pathways. Specifically, the genes encoding phosphoglucomutase activity (PGM1/PGM2), which connect GALactose catabolism to glycolysis, have gained and lost direct regulation by the transcription factor Gal4 several times during yeast evolution. Through targeted mutations of predicted Gal4-binding sites in yeast genomes, we show this galactose-mediated regulation of PGM1/2 supports vigorous growth on galactose in multiple yeast species, including Saccharomyces uvarum and Lachancea kluyveri. Furthermore, the addition of galactose-inducible PGM1 alone is sufficient to improve the growth on galactose of multiple species that lack this regulation, including Saccharomyces cerevisiae. The strong association between regulation of PGM1/2 by Gal4 even enables remarkably accurate predictions of galactose growth phenotypes between closely related species. This repeated mode of evolution suggests that this specific cis-regulatory connection is a common way that diverse yeasts can govern flux through the pathway, likely due to the constraints imposed by this pleiotropic bottleneck gene. Since metabolic pathways are highly interconnected, we argue that cis-regulatory evolution might be widespread at pleiotropic genes that control metabolic bottlenecks and intersections.

Profiling CCK-mediated pancreatic growth: the dynamic genetic program and the role of STATs as potential regulators.

PubMed

Gurda, Grzegorz T; Wang, Jackie Y; Guo, LiLi; Ernst, Stephen A; Williams, John A

2012-01-18

Feeding mice with protease inhibitor (PI) leads to increased endogenous cholecystokinin (CCK) release and results in pancreatic growth. This adaptive response requires calcineurin (CN)-NFAT and AKT-mTOR pathways, but the genes involved, the dynamics of their expression, and other regulatory pathways remain unknown. Here, we examined the early (1-8 h) transcriptional program that underlies pancreatic growth. We found 314 upregulated and 219 downregulated genes with diverse temporal and functional profiles. Several new identifications include the following: stress response genes Gdf15 and Txnip, metabolic mediators Pitpnc1 and Hmges2, as well as components of growth factor response Fgf21, Atf3, and Egr1. The genes fell into seven self-organizing clusters, each with a distinct pattern of expression; a representative gene within each of the upregulated clusters (Egr1, Gadd45b, Rgs2, and Serpinb1a) was validated by qRT-PCR. Genes up at any point throughout the time course and CN-dependent genes were subjected to further bioinformatics-based networking and promoter analysis, yielding STATs as potential transcriptional regulators. As shown by PCR, qPCR, and Western blots, the active phospho-form of STAT3 and the Jak-STAT feedback inhibitor Socs2 were both increased throughout early pancreatic growth. Moreover, immunohistochemistry showed a CCK-dependent and acinar cell-specific increase in nuclear localization of p-STAT3, with >75% nuclear occupancy in PI-fed mice vs. <0.1% in controls. Thus, the study identified novel genes likely to be important for CCK-driven pancreatic growth, characterized and biologically validated the dynamic pattern of their expression and investigated STAT-Socs signaling as a new player in this trophic response.

Identification of a regulatory T cell specific cell surface molecule that mediates suppressive signals and induces Foxp3 expression.

PubMed

Wang, Rui; Wan, Qi; Kozhaya, Lina; Fujii, Hodaka; Unutmaz, Derya

2008-07-16

Regulatory T (T(reg)) cells control immune activation and maintain tolerance. How T(regs) mediate their suppressive function is unclear. Here we identified a cell surface molecule, called GARP, (or LRRC32), which within T cells is specifically expressed in T(regs) activated through the T cell receptor (TCR). Ectopic expression of GARP in human naïve T (T(N)) cells inhibited their proliferation and cytokine secretion upon TCR activation. Remarkably, GARP over-expression in T(N) cells induced expression of T(reg) master transcription factor Foxp3 and endowed them with a partial suppressive function. The extracellular but not the cytoplasmic region of GARP, was necessary for these functions. Silencing Foxp3 in human T(reg) cells reduced expression of GARP and attenuated their suppressive function. However, GARP function was not affected when Foxp3 was downregulated in GARP-overexpressing cells, while silencing GARP in Foxp3-overexpressing cells reduced their suppressive activity. These findings reveal a novel cell surface molecule-mediated regulatory mechanism, with implications for modulating aberrant immune responses.

Network-directed cis-mediator analysis of normal prostate tissue expression profiles reveals downstream regulatory associations of prostate cancer susceptibility loci.

PubMed

Larson, Nicholas B; McDonnell, Shannon K; Fogarty, Zach; Larson, Melissa C; Cheville, John; Riska, Shaun; Baheti, Saurabh; Weber, Alexandra M; Nair, Asha A; Wang, Liang; O'Brien, Daniel; Davila, Jaime; Schaid, Daniel J; Thibodeau, Stephen N

2017-10-17

Large-scale genome-wide association studies have identified multiple single-nucleotide polymorphisms associated with risk of prostate cancer. Many of these genetic variants are presumed to be regulatory in nature; however, follow-up expression quantitative trait loci (eQTL) association studies have to-date been restricted largely to cis -acting associations due to study limitations. While trans -eQTL scans suffer from high testing dimensionality, recent evidence indicates most trans -eQTL associations are mediated by cis -regulated genes, such as transcription factors. Leveraging a data-driven gene co-expression network, we conducted a comprehensive cis -mediator analysis using RNA-Seq data from 471 normal prostate tissue samples to identify downstream regulatory associations of previously identified prostate cancer risk variants. We discovered multiple trans -eQTL associations that were significantly mediated by cis -regulated transcripts, four of which involved risk locus 17q12, proximal transcription factor HNF1B , and target trans -genes with known HNF response elements ( MIA2 , SRC , SEMA6A , KIF12 ). We additionally identified evidence of cis -acting down-regulation of MSMB via rs10993994 corresponding to reduced co-expression of NDRG1 . The majority of these cis -mediator relationships demonstrated trans -eQTL replicability in 87 prostate tissue samples from the Gene-Tissue Expression Project. These findings provide further biological context to known risk loci and outline new hypotheses for investigation into the etiology of prostate cancer.

Hormone-mediated growth dynamics of the barley pericarp as revealed by magnetic resonance imaging and transcript profiling

PubMed Central

Pielot, Rainer; Kohl, Stefan; Manz, Bertram; Rutten, Twan; Weier, Diana; Tarkowská, Danuše; Rolčík, Jakub; Strnad, Miroslav; Volke, Frank; Weber, Hans

2015-01-01

The shape of the maternal pericarp affects cereal grain mass and yield. Pericarp growth was analysed by magnetic resonance imaging (MRI), revealing topological maps of mobile water in developing pericarp of barley (Hordeum vulgare) and displaying tissue regions actively elongating in specific temporal–spatial patterns. Correlation analysis of MRI signals and growth rates reveals that growth in length is mediated by dorsal and also lateral rather than ventral regions. Growth in thickness is related to ventral regions. Switching from dorsal to ventral growth is associated with differential expression of axial regulators of the HD-ZipIII and Kanadi/Ettin types, and NPH3 photoreceptors, suggesting light-mediated auxin re-distribution. Auxin increases with the highest levels in the basal pericarp at 6 days after fertilization (DAF), together with transcriptionally up-regulated auxin transport and signalling. Gibberellin biosynthesis is transcriptionally up-regulated only later, and levels of bioactive gibberellins increase from 7 to 13 DAF, with higher levels in ventral than dorsal regions. Differential gene expression related to cell expansion indicates genes related to apoplast acidification, wall relaxation, sugar cleavage, water transport, and cell wall biosynthesis. Candidate genes potentially involved in pericarp extension are distinguished by their temporal expression, representing potential isoforms responsible for dorsal-mediated early growth in length or ventral-mediated late growth in thickness. PMID:26276866

Gene Targets in Prostate Tumor Cells that Mediate Aberrant Growth and Invasiveness

DTIC Science & Technology

2005-02-01

Craig A. Hauser , Ph.D. Gabriele Foos, Ph.D. CONTRACTING ORGANIZATION: The Burnham Institute La Jolla, California 92037 REPORT DATE: February 2005 TYPE...NUMBERS Gene Targets in Prostate Tumor Cells that Mediate DAMD17-02-1-0019 Aberrant Growth and Invasiveness 6. AUTHOR(S) Craig A. Hauser , Ph.D. Gabriele...REPORTABLE OUTCOMES Foos G, Hauser CA (2004) The role of Ets transcription factors in mediating cellular transformation. In: Handbook of Experimental

Cycles of Ubiquitination and Deubiquitination Critically Regulate Growth Factor-Mediated Activation of Akt Signaling

PubMed Central

Yang, Wei-Lei; Jin, Guoxiang; Li, Chien-Feng; Jeong, Yun Seong; Moten, Asad; Xu, Dazhi; Feng, Zizhen; Chen, Wei; Cai, Zhen; Darnay, Bryant; Gu, Wei; Lin, Hui-Kuan

2013-01-01

K63-linked ubiquitination of Akt is a posttranslational modification that plays a critical role in growth factor-mediated membrane recruitment and activation of Akt. Although E3 ligases involved in growth factor-induced Akt ubiquitination have been defined, the deubiquitinating enzyme (DUB) that triggers deubiquitination of Akt and the function of Akt deubiquitination remain largely unclear. Here, we showed that CYLD was a DUB for Akt and suppressed growth factor-mediated Akt ubiquitination and activation. CYLD directly removed ubiquitin moieties on Akt under serum-starved conditions. CYLD dissociated from Akt upon growth factor stimulation, thereby allowing E3 ligases to induce ubiquitination and activation of Akt. CYLD deficiency also promoted cancer cell proliferation, survival, glucose uptake and growth of prostate tumors. Our findings reveal the crucial role of cycles of ubiquitination and deubiquitination of Akt in its membrane recruitment and activation, and further identifies CYLD as a molecular switch for these processes. PMID:23300340

Resilience mediated the association between acculturation and psychological growth in college students from Hong Kong to Guangzhou, China.

PubMed

Yu, Nancy Xiaonan; Liu, Chang; Yue, Zhenzhu

2017-08-01

The number of Hong Kong citizens living in mainland China is increasing. The process of acculturation may create opportunities for psychological growth. This study aimed at examining whether resilience mediated the effects of acculturation on psychological growth in college students from Hong Kong to Guangzhou. In this cross-sectional survey, 164 college students in Guangzhou who were Hong Kong permanent residents (female: 46%, age: 21.09 ± 1.50) joined the study. The integration group reported more psychological growth than the assimilation, separation, and marginalization groups. Resilience partially mediated the effect of integration on psychological growth and fully mediated the effect of marginalization on psychological growth. Resilience represents one of the mechanisms to explain beneficial effects of integration on psychological growth in college students from Hong Kong to Guangzhou. Theoretical considerations to rethink the acculturation model, implications for developing intervention programs, and recommendations for future research are discussed.

Epigenetic profiling of growth plate chondrocytes sheds insight into regulatory genetic variation influencing height.

PubMed

Guo, Michael; Liu, Zun; Willen, Jessie; Shaw, Cameron P; Richard, Daniel; Jagoda, Evelyn; Doxey, Andrew C; Hirschhorn, Joel; Capellini, Terence D

2017-12-05

GWAS have identified hundreds of height-associated loci. However, determining causal mechanisms is challenging, especially since height-relevant tissues (e.g. growth plates) are difficult to study. To uncover mechanisms by which height GWAS variants function, we performed epigenetic profiling of murine femoral growth plates. The profiled open chromatin regions recapitulate known chondrocyte and skeletal biology, are enriched at height GWAS loci, particularly near differentially expressed growth plate genes, and enriched for binding motifs of transcription factors with roles in chondrocyte biology. At specific loci, our analyses identified compelling mechanisms for GWAS variants. For example, at CHSY1 , we identified a candidate causal variant (rs9920291) overlapping an open chromatin region. Reporter assays demonstrated that rs9920291 shows allelic regulatory activity, and CRISPR/Cas9 targeting of human chondrocytes demonstrates that the region regulates CHSY1 expression. Thus, integrating biologically relevant epigenetic information (here, from growth plates) with genetic association results can identify biological mechanisms important for human growth.

The kinases MEKK2 and MEKK3 regulate transforming growth factor-β-mediated helper T cell differentiation.

PubMed

Chang, Xing; Liu, Fang; Wang, Xiaofang; Lin, Aiping; Zhao, Hongyu; Su, Bing

2011-02-25

Mitogen-activated protein kinases (MAPKs) are key mediators of the T cell receptor (TCR) signals but their roles in T helper (Th) cell differentiation are unclear. Here we showed that the MAPK kinase kinases MEKK2 (encoded by Map3k2) and MEKK3 (encoded by Map3k3) negatively regulated transforming growth factor-β (TGF-β)-mediated Th cell differentiation. Map3k2(-/-)Map3k3(Lck-Cre/-) mice showed an abnormal accumulation of regulatory T (Treg) and Th17 cells in the periphery, consistent with Map3k2(-/-)Map3k3(Lck-Cre/-) naive CD4(+) T cells' differentiation into Treg and Th17 cells with a higher frequency than wild-type (WT) cells after TGF-β stimulation in vitro. In addition, Map3k2(-/-)Map3k3(Lck-Cre/-) mice developed more severe experimental autoimmune encephalomyelitis. Map3k2(-/-)Map3k3(Lck-Cre/-) T cells exhibited impaired phosphorylation of SMAD2 and SMAD3 proteins at their linker regions, which negatively regulated the TGF-β responses in T cells. Thus, the crosstalk between TCR-induced MAPK and the TGF-β signaling pathways is important in regulating Th cell differentiation. Copyright © 2011 Elsevier Inc. All rights reserved.

MEK inhibition prevents tumour-shed transforming growth factor-β-induced T-regulatory cell augmentation in tumour milieu.

PubMed

Hossain, Dewan M S; Panda, Abir K; Chakrabarty, Sreeparna; Bhattacharjee, Pushpak; Kajal, Kirti; Mohanty, Suchismita; Sarkar, Irene; Sarkar, Diptendra K; Kar, Santosh K; Sa, Gaurisankar

2015-04-01

Tumour progression is associated with immune-suppressive conditions that facilitate the escape of tumour cells from the regimen of immune cells, subsequently paralysing the host defence mechanisms. Induction of CD4(+)  CD25(+)  FoxP3(+) T regulatory (Treg) cells has been implicated in the tumour immune escape mechanism, although the novel anti-cancer treatment strategies targeting Treg cells remain unknown. The focus of this study is to define the interaction between tumour and immune system, i.e. how immune tolerance starts and gradually leads to the induction of adaptive Treg cells in the tumour microenvironment. Our study identified hyperactivated mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) -signalling as a potential target for reversing Treg cell augmentation in breast cancer patients. In more mechanistic detail, pharmacological inhibitors of MEK/ERK signalling inhibited transforming growth factor-β (TGF-β) production in tumour cells that essentially blocked TGF-β-SMAD3/SMAD4-mediated induction of CD25/interleukin-2 receptor α on CD4(+) T-cell surface. As a result high-affinity binding of interleukin-2 on those cells was prohibited, causing lack of Janus kinase 1 (JAK1)/JAK3-mediated signal transducer and activator of transcription 3 (STAT3)/STAT5 activation required for FoxP3 expression. Finally, for a more radical approach towards a safe MEK inhibitor, we validate the potential of multi-kinase inhibitor curcumin, especially the nano-curcumin made out of pure curcumin with greater bioavailability; in repealing tumour-shed TGF-β-induced Treg cell augmentation. © 2014 Bose Institute.

MEK inhibition prevents tumour-shed transforming growth factor-β-induced T-regulatory cell augmentation in tumour milieu

PubMed Central

Hossain, Dewan M S; Panda, Abir K; Chakrabarty, Sreeparna; Bhattacharjee, Pushpak; Kajal, Kirti; Mohanty, Suchismita; Sarkar, Irene; Sarkar, Diptendra K; Kar, Santosh K; Sa, Gaurisankar

2015-01-01

Tumour progression is associated with immune-suppressive conditions that facilitate the escape of tumour cells from the regimen of immune cells, subsequently paralysing the host defence mechanisms. Induction of CD4+ CD25+ FoxP3+ T regulatory (Treg) cells has been implicated in the tumour immune escape mechanism, although the novel anti-cancer treatment strategies targeting Treg cells remain unknown. The focus of this study is to define the interaction between tumour and immune system, i.e. how immune tolerance starts and gradually leads to the induction of adaptive Treg cells in the tumour microenvironment. Our study identified hyperactivated mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) -signalling as a potential target for reversing Treg cell augmentation in breast cancer patients. In more mechanistic detail, pharmacological inhibitors of MEK/ERK signalling inhibited transforming growth factor-β (TGF-β) production in tumour cells that essentially blocked TGF-β-SMAD3/SMAD4-mediated induction of CD25/interleukin-2 receptor α on CD4+ T-cell surface. As a result high-affinity binding of interleukin-2 on those cells was prohibited, causing lack of Janus kinase 1 (JAK1)/JAK3-mediated signal transducer and activator of transcription 3 (STAT3)/STAT5 activation required for FoxP3 expression. Finally, for a more radical approach towards a safe MEK inhibitor, we validate the potential of multi-kinase inhibitor curcumin, especially the nano-curcumin made out of pure curcumin with greater bioavailability; in repealing tumour-shed TGF-β-induced Treg cell augmentation. PMID:25284464

Ral-Arf6 crosstalk regulates Ral dependent exocyst trafficking and anchorage independent growth signalling.

PubMed

Pawar, Archana; Meier, Jeremy A; Dasgupta, Anwesha; Diwanji, Neha; Deshpande, Neha; Saxena, Kritika; Buwa, Natasha; Inchanalkar, Siddhi; Schwartz, Martin Alexander; Balasubramanian, Nagaraj

2016-09-01

Integrin dependent regulation of growth factor signalling confers anchorage dependence that is deregulated in cancers. Downstream of integrins and oncogenic Ras the small GTPase Ral is a vital mediator of adhesion dependent trafficking and signalling. This study identifies a novel regulatory crosstalk between Ral and Arf6 that controls Ral function in cells. In re-adherent mouse fibroblasts (MEFs) integrin dependent activation of RalA drives Arf6 activation. Independent of adhesion constitutively active RalA and RalB could both however activate Arf6. This is further conserved in oncogenic H-Ras containing bladder cancer T24 cells, which express anchorage independent active Ral that supports Arf6 activation. Arf6 mediates active Ral-exocyst dependent delivery of raft microdomains to the plasma membrane that supports anchorage independent growth signalling. Accordingly in T24 cells the RalB-Arf6 crosstalk is seen to preferentially regulate anchorage independent Erk signalling. Active Ral we further find uses a Ral-RalBP1-ARNO-Arf6 pathway to mediate Arf6 activation. This study hence identifies Arf6, through this regulatory crosstalk, to be a key downstream mediator of Ral isoform function along adhesion dependent pathways in normal and cancer cells. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Investigation of Mediational Processes Using Parallel Process Latent Growth Curve Modeling.

ERIC Educational Resources Information Center

Cheong, JeeWon; MacKinnon, David P.; Khoo, Siek Toon

2003-01-01

Investigated a method to evaluate mediational processes using latent growth curve modeling and tested it with empirical data from a longitudinal steroid use prevention program focusing on 1,506 high school football players over 4 years. Findings suggest the usefulness of the approach. (SLD)

Nitrogen modulation of legume root architecture signaling pathways involves phytohormones and small regulatory molecules.

PubMed

Mohd-Radzman, Nadiatul A; Djordjevic, Michael A; Imin, Nijat

2013-10-01

Nitrogen, particularly nitrate is an important yield determinant for crops. However, current agricultural practice with excessive fertilizer usage has detrimental effects on the environment. Therefore, legumes have been suggested as a sustainable alternative for replenishing soil nitrogen. Legumes can uniquely form nitrogen-fixing nodules through symbiotic interaction with specialized soil bacteria. Legumes possess a highly plastic root system which modulates its architecture according to the nitrogen availability in the soil. Understanding how legumes regulate root development in response to nitrogen availability is an important step to improving root architecture. The nitrogen-mediated root development pathway starts with sensing soil nitrogen level followed by subsequent signal transduction pathways involving phytohormones, microRNAs and regulatory peptides that collectively modulate the growth and shape of the root system. This review focuses on the current understanding of nitrogen-mediated legume root architecture including local and systemic regulations by different N-sources and the modulations by phytohormones and small regulatory molecules.

Reappraisal and suppression mediate the contribution of regulatory focus to anxiety in healthy adults.

PubMed

Llewellyn, Nicole; Dolcos, Sanda; Iordan, Alexandru D; Rudolph, Karen D; Dolcos, Florin

2013-08-01

Theory and research link regulatory focus (RF) in the form of promotion and prevention goal orientation with internalizing symptoms (e.g., anxiety), but the relevant mechanisms are not well understood. This study investigated the role of two emotion regulation (ER) strategies (cognitive reappraisal and expressive suppression) as possible mediators. Path analysis using data from 179 healthy young participants (110 women, 69 men) revealed that stronger promotion orientation was significantly associated with less anxiety, and that the use of reappraisal and suppression partially mediated this association. Prevention was associated with more suppression but was not directly associated with anxiety. There were no gender differences in these effects. Collectively, these findings suggest that effective ER, through heightened use of reappraisal and dampened use of suppression, serves as a mechanism through which promotion confers protection against anxiety. This research provides empirical support to initiatives aimed at promoting healthy psychological adjustment and preventing anxiety, by optimizing ER strategies with respect to RF goal orientations. PsycINFO Database Record (c) 2013 APA, all rights reserved.

The function of the Mediator complex in plant immunity.

PubMed

An, Chuanfu; Mou, Zhonglin

2013-03-01

Upon pathogen infection, plants undergo dramatic transcriptome reprogramming to shift from normal growth and development to immune response. During this rapid process, the multiprotein Mediator complex has been recognized as an important player to fine-tune gene-specific and pathway-specific transcriptional reprogramming by acting as an adaptor/coregulator between sequence-specific transcription factor and RNA polymerase II (RNAPII). Here, we review current understanding of the role of five functionally characterized Mediator subunits (MED8, MED15, MED16, MED21 and MED25) in plant immunity. All these Mediator subunits positively regulate resistance against leaf-infecting biotrophic bacteria or necrotrophic fungi. While MED21 appears to regulate defense against fungal pathogens via relaying signals from upstream regulators and chromatin modification to RNAPII, the other four Mediator subunits locate at different positions of the defense network to convey phytohormone signal(s). Fully understanding the role of Mediator in plant immunity needs to characterize more Mediator subunits in both Arabidopsis and other plant species. Identification of interacting proteins of Mediator subunits will further help to reveal their specific regulatory mechanisms in plant immunity.

A domesticated transposon mediates the effects of a single-nucleotide polymorphism responsible for enhanced muscle growth.

PubMed

Butter, Falk; Kappei, Dennis; Buchholz, Frank; Vermeulen, Michiel; Mann, Matthias

2010-04-01

Single-nucleotide polymorphisms (SNPs) in the regulatory regions of the genome can have a profound impact on phenotype. The G3072A polymorphism in intron 3 of insulin-like growth factor 2 (IGF2) is implicated in higher muscle content and reduced fat in European pigs and is bound by a putative repressor. Here, we identify this repressor--which we call muscle growth regulator (MGR)--by using a DNA protein interaction screen based on quantitative mass spectrometry. MGR has a bipartite nuclear localization signal, two BED-type zinc fingers and is highly conserved between placental mammals. Surprisingly, the gene is located in an intron and belongs to the hobo-Ac-Tam3 transposase superfamily, suggesting regulatory use of a formerly parasitic element. In transactivation assays, MGR differentially represses the expression of the two SNP variants. Knockdown of MGR in C2C12 myoblast cells upregulates Igf2 expression and mild overexpression retards growth. Thus, MGR is the repressor responsible for enhanced muscle growth in the IGF2 G3072A polymorphism in commercially bred pigs.

Regulatory effects of ferritin on angiogenesis

PubMed Central

Coffman, Lan G.; Parsonage, Derek; D'Agostino, Ralph; Torti, Frank M.; Torti, Suzy V.

2009-01-01

Angiogenesis, the synthesis of new blood vessels from preexisting vessels, plays a critical role in normal wound healing and tumor growth. HKa (cleaved high molecular weight kininogen) is an endogenous inhibitor of angiogenesis formed by the cleavage of kininogen on endothelial cells. Ferritin is a protein principally known for its central role in iron storage. Here, we demonstrate that ferritin binds to HKa with high affinity (Kd 13 nM). Further, ferritin antagonizes the antiangiogenic effects of HKa, enhancing the migration, assembly, and survival of HKa-treated endothelial cells. Effects of ferritin were independent of its iron content. Peptide mapping revealed that ferritin binds to a 22-aa subdomain of HKa that is critical to its antiangiogenic activity. In vivo, ferritin opposed HKa's antiangiogenic effects in a human prostate cancer xenograft, restoring tumor-dependent vessel growth. Ferritin-mediated regulation of angiogenesis represents a new angiogenic regulatory pathway, and identifies a new role for ferritin in cell biology. PMID:19126685

The Hippo effector Yorkie controls normal tissue growth by antagonizing scalloped-mediated default repression.

PubMed

Koontz, Laura M; Liu-Chittenden, Yi; Yin, Feng; Zheng, Yonggang; Yu, Jianzhong; Huang, Bo; Chen, Qian; Wu, Shian; Pan, Duojia

2013-05-28

The Hippo tumor suppressor pathway restricts tissue growth by inactivating the transcriptional coactivator Yki. Although Sd has been implicated as a DNA-binding transcription factor partner for Yki and can genetically account for gain-of-function Yki phenotypes, how Yki regulates normal tissue growth remains a long-standing puzzle because Sd, unlike Yki, is dispensable for normal growth in most Drosophila tissues. Here we show that the yki mutant phenotypes in multiple developmental contexts are rescued by inactivation of Sd, suggesting that Sd functions as a default repressor and that Yki promotes normal tissue growth by relieving Sd-mediated default repression. We further identify Tgi as a cofactor involved in Sd's default repressor function and demonstrate that the mammalian ortholog of Tgi potently suppresses the YAP oncoprotein in transgenic mice. These findings fill a major gap in Hippo-mediated transcriptional regulation and open up possibilities for modulating the YAP oncoprotein in cancer and regenerative medicine. Copyright © 2013 Elsevier Inc. All rights reserved.

The SnRK2-APC/CTE regulatory module mediates the antagonistic action of gibberellic acid and abscisic acid pathways

PubMed Central

Lin, Qibing; Wu, Fuqing; Sheng, Peike; Zhang, Zhe; Zhang, Xin; Guo, Xiuping; Wang, Jiulin; Cheng, Zhijun; Wang, Jie; Wang, Haiyang; Wan, Jianmin

2015-01-01

Abscisic acid (ABA) and gibberellic acid (GA) antagonistically regulate many developmental processes and responses to biotic or abiotic stresses in higher plants. However, the molecular mechanism underlying this antagonism is still poorly understood. Here, we show that loss-of-function mutation in rice Tiller Enhancer (TE), an activator of the APC/CTE complex, causes hypersensitivity and hyposensitivity to ABA and GA, respectively. We find that TE physically interacts with ABA receptor OsPYL/RCARs and promotes their degradation by the proteasome. Genetic analysis also shows OsPYL/RCARs act downstream of TE in mediating ABA responses. Conversely, ABA inhibits APC/CTE activity by phosphorylating TE through activating the SNF1-related protein kinases (SnRK2s), which may interrupt the interaction between TE and OsPYL/RCARs and subsequently stabilize OsPYL/RCARs. In contrast, GA can reduce the level of SnRK2s and may promote APC/CTE-mediated degradation of OsPYL/RCARs. Thus, we propose that the SnRK2-APC/CTE regulatory module represents a regulatory hub underlying the antagonistic action of GA and ABA in plants. PMID:26272249

LC3-mediated fibronectin mRNA translation induces fibrosarcoma growth by increasing connective tissue growth factor

PubMed Central

Ying, Lihua; Lau, Agatha; Alvira, Cristina M.; West, Robert; Cann, Gordon M.; Zhou, Bin; Kinnear, Caroline; Jan, Eric; Sarnow, Peter; Van de Rijn, Matt; Rabinovitch, Marlene

2009-01-01

Summary Previously, we related fibronectin (Fn1) mRNA translation to an interaction between an AU-rich element in the Fn1 3′ UTR and light chain 3 (LC3) of microtubule-associated proteins 1A and 1B. Since human fibrosarcoma (HT1080) cells produce little fibronectin and LC3, we used these cells to investigate how LC3-mediated Fn1 mRNA translation might alter tumor growth. Transfection of HT1080 cells with LC3 enhanced fibronectin mRNA translation. Using polysome analysis and RNA-binding assays, we show that elevated levels of translation depend on an interaction between a triple arginine motif in LC3 and the AU-rich element in Fn1 mRNA. Wild-type but not mutant LC3 accelerated HT1080 cell growth in culture and when implanted in SCID mice. Comparison of WT LC3 with vector-transfected HT1080 cells revealed increased fibronectin-dependent proliferation, adhesion and invasion. Microarray analysis of genes differentially expressed in WT and vector-transfected control cells indicated enhanced expression of connective tissue growth factor (CTGF). Using siRNA, we show that enhanced expression of CTGF is fibronectin dependent and that LC3-mediated adhesion, invasion and proliferation are CTGF dependent. Expression profiling of soft tissue tumors revealed increased expression of both LC3 and CTGF in some locally invasive tumor types. PMID:19366727

Methionine-Mediated Repression in Saccharomyces cerevisiae: a Pleiotropic Regulatory System Involving Methionyl Transfer Ribonucleic Acid and the Product of Gene eth2

PubMed Central

Cherest, H.; Surdin-Kerjan, Y.; De Robichon-Szulmajster, H.

1971-01-01

Detailed study of methionine-mediated repression of enzymes involved in methionine biosynthesis in Saccharomyces cerevisiae led to classification of these enzymes into two distinct regulatory groups. Group I comprises four enzymes specifically involved in different parts of methionine biosynthesis, namely, homoserine-O-transacetylase, homocysteine synthetase, adenosine triphosphate sulfurylase, and sulfite reductase. Repressibility of these enzymes is greatly decreased in strains carrying a genetically impaired methionyl-transfer ribonucleic acid (tRNA) synthetase (mutation ts− 296). Conditions leading to absence of repression in the mutant strain have been correlated with a sharp decrease in bulk tRNAmet charging, whereas conditions which restore repressibility of group I enzymes also restore tRNAmet charging. These findings implicate methionyl-tRNA in the regulatory process. However, the absence of a correlation in the wild type between methionyl-tRNA charging and the levels of methionine group I enzymes suggests that only a minor iso accepting species of tRNAmet may be devoted with a regulatory function. Repressibility of the same four enzymes (group I) was also decreased in strains carrying the regulatory mutation eth2r. Although structural genes coding for two of these enzymes, as well as mutations ts− 296 and eth2r segregate independently to each other, synthesis of group I enzymes is coordinated. The pleiotropic regulatory system involved seems then to comprise beside a “regulatory methionyl tRNAmet,” another element, product of gene eth2, which might correspond either to an aporepressor protein or to the “regulatory tRNAmet” itself. Regulation of group II enzymes is defined by response to exogenous methionine, absence of response to either mutations ts− 296 and eth2r, and absence of coordinacy with group I enzymes. However, the two enzymes which belong to this group and are both involved in threonine and methionine biosynthesis undergo

Growth Inhibition by Bupivacaine Is Associated with Inactivation of Ribosomal Protein S6 Kinase 1

PubMed Central

Beigh, Mushtaq Ahmad; Showkat, Mehvish; Bashir, Basharat; Bashir, Asma; Hussain, Mahboob ul; Andrabi, Khurshid Iqbal

2014-01-01

Bupivacaine is an amide type long acting local anesthetic used for epidural anesthesia and nerve blockade in patients. Use of bupivacaine is associated with severe cytotoxicity and apoptosis along with inhibition of cell growth and proliferation. Although inhibition of Erk, Akt, and AMPK seemingly appears to mediate some of the bupivacaine effects, potential downstream targets that mediate its effect remain unknown. S6 kinase 1 is a common downstream effector of several growth regulatory pathways involved in cell growth and proliferation known to be affected by bupivacaine. We have accordingly attempted to relate the growth inhibitory effects of bupivacaine with the status of S6K1 activity and we present evidence that decrease in cell growth and proliferation by bupivacaine is mediated through inactivation of S6 kinase 1 in a concentration and time dependent manner. We also show that ectopic expression of constitutively active S6 kinase 1 imparts substantial protection from bupivacaine induced cytotoxicity. Inactivation of S6K1 though associated with loss of putative mTOR mediated phosphorylation did not correspond with loss of similar phosphorylations in 4EBP1 indicating that S6K1 inhibition was not mediated through inactivation of mTORC1 signaling pathway or its down regulation. PMID:24605337

Adenoviral vector-mediated GM-CSF gene transfer improves anti-mycobacterial immunity in mice - role of regulatory T cells.

PubMed

Singpiel, Alena; Kramer, Julia; Maus, Regina; Stolper, Jennifer; Bittersohl, Lara Friederike; Gauldie, Jack; Kolb, Martin; Welte, Tobias; Sparwasser, Tim; Maus, Ulrich A

2018-03-01

Granulocyte macrophage-colony stimulating factor (GM-CSF) is a hematopoietic growth factor involved in differentiation, survival and activation of myeloid and non-myeloid cells with important implications for lung antibacterial immunity. Here we examined the effect of pulmonary adenoviral vector-mediated delivery of GM-CSF (AdGM-CSF) on anti-mycobacterial immunity in M. bovis BCG infected mice. Exposure of M. bovis BCG infected mice to AdGM-CSF either applied on 6h, or 6h and 7days post-infection substantially increased alveolar recruitment of iNOS and IL-12 expressing macrophages, and significantly increased accumulation of IFNγ pos T cells and particularly regulatory T cells (Tregs). This was accompanied by significantly reduced mycobacterial loads in the lungs of mice. Importantly, diphtheria toxin-induced depletion of Tregs did not influence mycobacterial loads, but accentuated immunopathology in AdGM-CSF-exposed mice infected with M. bovis BCG. Together, the data demonstrate that AdGM-CSF therapy improves lung protective immunity against M. bovis BCG infection in mice independent of co-recruited Tregs, which however critically contribute to limit lung immunopathology in BCG-infected mice. These data may be relevant to the development of immunomodulatory strategies to limit immunopathology-based lung injury in tuberculosis in humans. Copyright © 2017 Elsevier GmbH. All rights reserved.

Both positive and negative regulatory elements mediate expression of a photoregulated CAB gene from Nicotiana plumbaginifolia.

PubMed Central

Castresana, C; Garcia-Luque, I; Alonso, E; Malik, V S; Cashmore, A R

1988-01-01

We have analyzed promoter regulatory elements from a photoregulated CAB gene (Cab-E) isolated from Nicotiana plumbaginifolia. These studies have been performed by introducing chimeric gene constructs into tobacco cells via Agrobacterium tumefaciens-mediated transformation. Expression studies on the regenerated transgenic plants have allowed us to characterize three positive and one negative cis-acting elements that influence photoregulated expression of the Cab-E gene. Within the upstream sequences we have identified two positive regulatory elements (PRE1 and PRE2) which confer maximum levels of photoregulated expression. These sequences contain multiple repeated elements related to the sequence-ACCGGCCCACTT-. We have also identified within the upstream region a negative regulatory element (NRE) extremely rich in AT sequences, which reduces the level of gene expression in the light. We have defined a light regulatory element (LRE) within the promoter region extending from -396 to -186 bp which confers photoregulated expression when fused to a constitutive nopaline synthase ('nos') promoter. Within this region there is a 132-bp element, extending from -368 to -234 bp, which on deletion from the Cab-E promoter reduces gene expression from high levels to undetectable levels. Finally, we have demonstrated for a full length Cab-E promoter conferring high levels of photoregulated expression, that sequences proximal to the Cab-E TATA box are not replaceable by corresponding sequences from a 'nos' promoter. This contrasts with the apparent equivalence of these Cab-E and 'nos' TATA box-proximal sequences in truncated promoters conferring low levels of photoregulated expression. Images PMID:2901343

Mouse regulatory DNA landscapes reveal global principles of cis-regulatory evolution.

PubMed

Vierstra, Jeff; Rynes, Eric; Sandstrom, Richard; Zhang, Miaohua; Canfield, Theresa; Hansen, R Scott; Stehling-Sun, Sandra; Sabo, Peter J; Byron, Rachel; Humbert, Richard; Thurman, Robert E; Johnson, Audra K; Vong, Shinny; Lee, Kristen; Bates, Daniel; Neri, Fidencio; Diegel, Morgan; Giste, Erika; Haugen, Eric; Dunn, Douglas; Wilken, Matthew S; Josefowicz, Steven; Samstein, Robert; Chang, Kai-Hsin; Eichler, Evan E; De Bruijn, Marella; Reh, Thomas A; Skoultchi, Arthur; Rudensky, Alexander; Orkin, Stuart H; Papayannopoulou, Thalia; Treuting, Piper M; Selleri, Licia; Kaul, Rajinder; Groudine, Mark; Bender, M A; Stamatoyannopoulos, John A

2014-11-21

To study the evolutionary dynamics of regulatory DNA, we mapped >1.3 million deoxyribonuclease I-hypersensitive sites (DHSs) in 45 mouse cell and tissue types, and systematically compared these with human DHS maps from orthologous compartments. We found that the mouse and human genomes have undergone extensive cis-regulatory rewiring that combines branch-specific evolutionary innovation and loss with widespread repurposing of conserved DHSs to alternative cell fates, and that this process is mediated by turnover of transcription factor (TF) recognition elements. Despite pervasive evolutionary remodeling of the location and content of individual cis-regulatory regions, within orthologous mouse and human cell types the global fraction of regulatory DNA bases encoding recognition sites for each TF has been strictly conserved. Our findings provide new insights into the evolutionary forces shaping mammalian regulatory DNA landscapes. Copyright © 2014, American Association for the Advancement of Science.

Regulation of cell growth by redox-mediated extracellular proteolysis of platelet-derived growth factor receptor beta.

PubMed

Okuyama, H; Shimahara, Y; Kawada, N; Seki, S; Kristensen, D B; Yoshizato, K; Uyama, N; Yamaoka, Y

2001-07-27

Redox-regulated processes are important elements in various cellular functions. Reducing agents, such as N-acetyl-l-cysteine (NAC), are known to regulate signal transduction and cell growth through their radical scavenging action. However, recent studies have shown that reactive oxygen species are not always involved in ligand-stimulated intracellular signaling. Here, we report a novel mechanism by which NAC blocks platelet-derived growth factor (PDGF)-induced signaling pathways in hepatic stellate cells, a fibrogenic player in the liver. Unlike in vascular smooth muscle cells, we found that reducing agents, including NAC, triggered extracellular proteolysis of PDGF receptor-beta, leading to desensitization of hepatic stellate cells toward PDGF-BB. This effect was mediated by secreted mature cathepsin B. In addition, type II transforming growth factor-beta receptor was also down-regulated. Furthermore, these events seemed to cause a dramatic improvement of rat liver fibrosis. These results indicated that redox processes impact the cell's response to growth factors by regulating the turnover of growth factor receptors and that "redox therapy" is promising for fibrosis-related disease.

Gallium-mediated growth of multiwall carbon nanotubes

NASA Astrophysics Data System (ADS)

Pan, Zheng Wei; Dai, Sheng; Beach, David B.; Evans, Neal D.; Lowndes, Douglas H.

2003-03-01

Liquid gallium was used as a viable and effective solvent and template for high-yield growth of multiwall carbon nanotubes. The gallium-mediated nanotubes thus obtained differ morphologically from nanotubes obtained by using transition metals as catalysts. The nanotubes have a pin-like morphology, generally composed of an oval-shaped tip filled with liquid gallium and a tapered hollow body. The inner diameter of the tube is so large that the inner/outer diameter ratio is usually larger than 0.9. The tubes are naturally opened at both ends. These gallium-filled nanotubes may be used as a nanothermometer in the temperature range of 30 to 550 °C. This study opens an interesting route for carbon nanotube synthesis.

Fatal autoimmune hepatitis induced by concurrent loss of naturally arising regulatory T cells and PD-1-mediated signaling.

PubMed

Kido, Masahiro; Watanabe, Norihiko; Okazaki, Taku; Akamatsu, Takuji; Tanaka, Junya; Saga, Kazuyuki; Nishio, Akiyoshi; Honjo, Tasuku; Chiba, Tsutomu

2008-10-01

Because of the lack of animal models developing spontaneous autoimmune hepatitis (AIH), the molecular mechanisms involved in the development of AIH are still unclear. This study aims to examine the regulatory roles of naturally arising CD4(+)CD25(+) regulatory T (Treg) cells and programmed cell death 1 (PD-1)-mediated signaling in the development of AIH. To induce a concurrent loss of Treg cells and PD-1-mediated signaling, neonatal thymectomy (NTx), which severely reduces the number of Treg cells, was performed on PD-1(-/-) mice. After the NTx, we performed histologic examination, assessed autoantibody production and infiltrating cells in the liver, and conducted adoptive transfer experiments. In contrast to NTx mice and PD-1(-/-) mice, NTx-PD-1(-/-) mice produced antinuclear antibodies and developed fatal hepatitis characterized by a CD4(+) and CD8(+) T-cell infiltration invading the parenchyma with massive lobular necrosis. Induction of AIH in NTx-PD-1(-/-) mice was suppressed by transfer of Treg cells, even derived from PD-1(-/-) mice. Transfer of total but not CD4(+) T-cell-depleted splenocytes from NTx-PD-1(-/-) mice into RAG2(-/-) mice induced the development of severe hepatitis. In contrast, the transfer of CD8(+) T-cell-depleted splenocytes triggered only mononuclear infiltrates without massive necrosis of the parenchyma. NTx-PD-1(-/-) mice are the first mouse model of spontaneous fatal AIH. The concurrent loss of Treg cells and PD-1-mediated signaling can induce the development of fatal AIH. Autoreactive CD4(+) T cells are essential for induction of AIH, whereas CD8(+) T cells play an important role in progression to fatal hepatic damage.

Pulmonary stromal cells induce the generation of regulatory DC attenuating T-cell-mediated lung inflammation.

PubMed

Li, Qian; Guo, Zhenhong; Xu, Xiongfei; Xia, Sheng; Cao, Xuetao

2008-10-01

The tissue microenvironment may affect the development and function of immune cells such as DC. Whether and how the pulmonary stromal microenvironment can affect the development and function of lung DC need to be investigated. Regulatory DC (DCreg) can regulate T-cell response. We wondered whether such regulatory DC exist in the lung and what is the effect of the pulmonary stromal microenvironment on the generation of DCreg. Here we demonstrate that murine pulmonary stromal cells can drive immature DC, which are regarded as being widely distributed in the lung, to proliferate and differentiate into a distinct subset of DCreg, which express high levels of CD11b but low levels of MHC class II (I-A), CD11c, secrete high amounts of IL-10, NO and prostaglandin E2 (PGE2) and suppress T-cell proliferation. The natural counterpart of DCreg in the lung with similar phenotype and regulatory function has been identified. Pulmonary stroma-derived TGF-beta is responsible for the differentiation of immature DC to DCreg, and DCreg-derived PGE2 contributes to their suppression of T-cell proliferation. Moreover, DCreg can induce the generation of CD4+CD25+Foxp3+ Treg. Importantly, infusion with DCreg attenuates T-cell-mediated eosinophilic airway inflammation in vivo. Therefore, the pulmonary microenvironment may drive the generation of DCreg, thus contributing to the maintenance of immune homoeostasis and the control of inflammation in the lung.

Adenosine A(2B) receptor antagonist PSB603 suppresses tumor growth and metastasis by inhibiting induction of regulatory T cells.

PubMed

Kaji, Wakako; Tanaka, Satomi; Tsukimoto, Mitsutoshi; Kojima, Shuji

2014-04-01

Regulatory T cells (Treg) play a role in suppression of immune response, including anti-tumor immunity. We have recently reported that treatment of naïve CD4 T cells with adenosine A(2B) receptor antagonist PSB603 under Treg-skewing conditions inhibits expression of Foxp3, a marker of differentiation to Treg, without blocking IL-2 production or CD25 expression, which are activation markers, in CD4 T cells. We hypothesized that PSB603 suppresses cancer growth and metastasis by inhibiting induction of Treg, thereby facilitating anti-tumor immunity. In this study, we first examined the effect of PSB603 on tumor growth in B16 melanoma-bearing C57BL/6 mice. Administration of PSB603 significantly suppressed the increase of tumor volume as well as the increase of Treg population in these mice. The populations of CD4 and CD8 T cells were higher and splenic lymphocyte-mediated cytotoxicity towards B16 melanoma was significantly increased in PSB603-treated mice. We confirmed that PSB603 did not reduce the viability of B16 melanoma cells in vitro. Moreover, we also examined the effect of PSB603 on tumor metastasis in pulmonary metastasis model mice intravenously injected with B16 melanoma cells. The metastasis was also suppressed in PSB603-treated mice, in which the population of Treg was significantly lower. Overall, our results suggest that A(2B) receptor antagonist PSB603 enhances anti-tumor immunity by inhibiting differentiation to Treg, resulting in a delay of tumor growth and a suppression of metastasis.

Regulatory T cells protect mice against coxsackievirus-induced myocarditis through the transforming growth factor beta-coxsackie-adenovirus receptor pathway.

PubMed

Shi, Yu; Fukuoka, Masahiro; Li, Guohua; Liu, Youan; Chen, Manyin; Konviser, Michael; Chen, Xin; Opavsky, Mary Anne; Liu, Peter P

2010-06-22

Coxsackievirus B3 infection is an excellent model of human myocarditis and dilated cardiomyopathy. Cardiac injury is caused either by a direct cytopathic effect of the virus or through immune-mediated mechanisms. Regulatory T cells (Tregs) play an important role in the negative modulation of host immune responses and set the threshold of autoimmune activation. This study was designed to test the protective effects of Tregs and to determine the underlying mechanisms. Carboxyfluorescein diacetate succinimidyl ester-labeled Tregs or naïve CD4(+) T cells were injected intravenously once every 2 weeks 3 times into mice. The mice were then challenged with intraperitoneal coxsackievirus B3 immediately after the last cell transfer. Transfer of Tregs showed higher survival rates than transfer of CD4(+) T cells (P=0.0136) but not compared with the PBS injection group (P=0.0589). Interestingly, Tregs also significantly decreased virus titers and inflammatory scores in the heart. Transforming growth factor-beta and phosphorylated AKT were upregulated in Tregs-transferred mice and coxsackie-adenovirus receptor expression was decreased in the heart compared with control groups. Transforming growth factor-beta decreased coxsackie-adenovirus receptor expression and inhibited coxsackievirus B3 infection in HL-1 cells and neonatal cardiac myocytes. Splenocytes collected from Treg-, CD4(+) T-cell-, and PBS-treated mice proliferated equally when stimulated with heat-inactivated virus, whereas in the Treg group, the proliferation rate was reduced significantly when stimulated with noninfected heart tissue homogenate. Adoptive transfer of Tregs protected mice from coxsackievirus B3-induced myocarditis through the transforming growth factor beta-coxsackie-adenovirus receptor pathway and thus suppresses the immune response to cardiac tissue, maintaining the antiviral immune response.

Smad7 Protein Induces Interferon Regulatory Factor 1-dependent Transcriptional Activation of Caspase 8 to Restore Tumor Necrosis Factor-related Apoptosis-inducing Ligand (TRAIL)-mediated Apoptosis

PubMed Central

Hong, Suntaek; Kim, Hye-Youn; Kim, Jooyoung; Ha, Huyen Trang; Kim, Young-Mi; Bae, Eunjin; Kim, Tae Hyung; Lee, Kang Choon; Kim, Seong-Jin

2013-01-01

Smad7 has been known as a negative regulator for the transforming growth factor-β (TGF-β) signaling pathway through feedback regulation. However, Smad7 has been suspected to have other biological roles through the regulation of gene transcription. By screening differentially regulated genes, we found that the caspase 8 gene was highly up-regulated in Smad7-expressing cells. Smad7 was able to activate the caspase 8 promoter through recruitment of the interferon regulatory factor 1 (IRF1) transcription factor to the interferon-stimulated response element (ISRE) site. Interaction of Smad7 on the caspase 8 promoter was confirmed with electrophoretic mobility shift assay and chromatin immunoprecipitation experiment. Interestingly, Smad7 did not directly interact with the ISRE site, but it increased the binding activity of IRF1 with ISRE. These results support that Smad7 recruits IRF1 protein on the caspase 8 promoter and functions as a transcriptional coactivator. To confirm the biological significance of caspase 8 up-regulation, we tested tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL)-mediated cell death assay in breast cancer cells. Smad7 in apoptosis-resistant MCF7 cells markedly sensitized the cells to TRAIL-induced cell death by restoring the caspase cascade. Furthermore, restoration of caspase 8-mediated apoptosis pathway repressed the tumor growth in the xenograft model. In conclusion, we suggest a novel role for Smad7 as a transcriptional coactivator for caspase 8 through the interaction with IRF1 in regulation of the cell death pathway. PMID:23255602

β-Arrestins: Regulatory Role and Therapeutic Potential in Opioid and Cannabinoid Receptor-Mediated Analgesia

PubMed Central

Bohn, Laura M.

2016-01-01

Pain is a complex disorder with neurochemical and psychological components contributing to the severity, the persistence, and the difficulty in adequately treating the condition. Opioid and cannabinoids are two classes of analgesics that have been used to treat pain for centuries and are arguably the oldest of “pharmacological” interventions used by man. Unfortunately, they also produce several adverse side effects that can complicate pain management. Opioids and cannabinoids act at G protein-coupled receptors (GPCRs), and much of their effects are mediated by the mu-opioid receptor (MOR) and cannabinoid CB1 receptor (CB1R), respectively. These receptors couple to intracellular second messengers and regulatory proteins to impart their biological effects. In this chapter, we review the role of the intracellular regulatory proteins, β-arrestins, in modulating MOR and CB1R and how they influence the analgesic and side-effect profiles of opioid and cannabinoid drugs in vivo. This review of the literature suggests that the development of opioid and cannabinoid agonists that bias MOR and CB1R toward G protein signaling cascades and away from β-arrestin interactions may provide a novel mechanism by which to produce analgesia with less severe adverse effects. PMID:24292843

Shape-dependent control of cell growth, differentiation, and apoptosis: switching between attractors in cell regulatory networks

NASA Technical Reports Server (NTRS)

Huang, S.; Ingber, D. E.

2000-01-01

Development of characteristic tissue patterns requires that individual cells be switched locally between different phenotypes or "fates;" while one cell may proliferate, its neighbors may differentiate or die. Recent studies have revealed that local switching between these different gene programs is controlled through interplay between soluble growth factors, insoluble extracellular matrix molecules, and mechanical forces which produce cell shape distortion. Although the precise molecular basis remains unknown, shape-dependent control of cell growth and function appears to be mediated by tension-dependent changes in the actin cytoskeleton. However, the question remains: how can a generalized physical stimulus, such as cell distortion, activate the same set of genes and signaling proteins that are triggered by molecules which bind to specific cell surface receptors. In this article, we use computer simulations based on dynamic Boolean networks to show that the different cell fates that a particular cell can exhibit may represent a preprogrammed set of common end programs or "attractors" which self-organize within the cell's regulatory networks. In this type of dynamic network model of information processing, generalized stimuli (e.g., mechanical forces) and specific molecular cues elicit signals which follow different trajectories, but eventually converge onto one of a small set of common end programs (growth, quiescence, differentiation, apoptosis, etc.). In other words, if cells use this type of information processing system, then control of cell function would involve selection of preexisting (latent) behavioral modes of the cell, rather than instruction by specific binding molecules. Importantly, the results of the computer simulation closely mimic experimental data obtained with living endothelial cells. The major implication of this finding is that current methods used for analysis of cell function that rely on characterization of linear signaling pathways or

Rapid formin-mediated actin-filament elongation is essential for polarized plant cell growth.

PubMed

Vidali, Luis; van Gisbergen, Peter A C; Guérin, Christophe; Franco, Paula; Li, Ming; Burkart, Graham M; Augustine, Robert C; Blanchoin, Laurent; Bezanilla, Magdalena

2009-08-11

Formins are present in all eukaryotes and are essential for the creation of actin-based structures responsible for diverse cellular processes. Because multicellular organisms contain large formin gene families, establishing the physiological functions of formin isoforms has been difficult. Using RNAi, we analyzed the function of all 9 formin genes within the moss Physcomitrella patens. We show that plants lacking class II formins (For2) are severely stunted and composed of spherical cells with disrupted actin organization. In contrast, silencing of all other formins results in normal elongated cell morphology and actin organization. Consistent with a role in polarized growth, For2 are apically localized in growing cells. We show that an N-terminal phosphatase tensin (PTEN)-like domain mediates apical localization. The PTEN-like domain is followed by a conserved formin homology (FH)1-FH2 domain, known to promote actin polymerization. To determine whether apical localization of any FH1-FH2 domain mediates polarized growth, we performed domain swapping. We found that only the class II FH1-FH2, in combination with the PTEN-like domain, rescues polarized growth, because it cannot be replaced with a similar domain from a For1. We used in vitro polymerization assays to dissect the functional differences between these FH1-FH2 domains. We found that both the FH1 and the FH2 domains from For2 are required to mediate exceptionally rapid rates of actin filament elongation, much faster than any other known formin. Thus, our data demonstrate that rapid rates of actin elongation are critical for driving the formation of apical filamentous actin necessary for polarized growth.

Emerging functions of multi-protein complex Mediator with special emphasis on plants.

PubMed

Malik, Naveen; Agarwal, Pinky; Tyagi, Akhilesh

2017-10-01

Mediator is a multi-subunit protein complex which is involved in transcriptional regulation in yeast and other eukaryotes. As a co-activator, it connects information from transcriptional activators/repressors to transcriptional machinery including RNA polymerase II and general transcription factors. It is not only involved in transcription initiation but also has important roles to play in transcription elongation and termination. Functional attributes of different Mediator subunits have been largely defined in yeast and mammalian systems earlier, while such studies in plants have gained momentum recently. Mediator regulates various processes related to plant development and is also involved in biotic and abiotic stress response. Thus, plant Mediator, like yeast and mammalian Mediator complex, is indispensable for plant growth and survival. Interaction of its multiple subunits with other regulatory proteins and their ectopic expression or knockdown in model plant like Arabidopsis and certain crop plants are paving the way to biochemical analysis and unravel molecular mechanisms of action of Mediator in plants.

10 CFR 4.333 - Mediation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Mediation. 4.333 Section 4.333 Energy NUCLEAR REGULATORY... Investigation, Conciliation, and Enforcement Procedures § 4.333 Mediation. (a) Referral of complaints for mediation. NRC will refer to a mediation agency designated by the Secretary of the Department of Health and...

Fibroblast Growth Factor Signaling Mediates Pulmonary Endothelial Glycocalyx Reconstitution

PubMed Central

Yang, Yimu; Haeger, Sarah M.; Suflita, Matthew A.; Zhang, Fuming; Dailey, Kyrie L.; Colbert, James F.; Ford, Joshay A.; Picon, Mario A.; Stearman, Robert S.; Lin, Lei; Liu, Xinyue; Han, Xiaorui; Linhardt, Robert J.

2017-01-01

The endothelial glycocalyx is a heparan sulfate (HS)–rich endovascular structure critical to endothelial function. Accordingly, endothelial glycocalyx degradation during sepsis contributes to tissue edema and organ injury. We determined the endogenous mechanisms governing pulmonary endothelial glycocalyx reconstitution, and if these reparative mechanisms are impaired during sepsis. We performed intravital microscopy of wild-type and transgenic mice to determine the rapidity of pulmonary endothelial glycocalyx reconstitution after nonseptic (heparinase-III mediated) or septic (cecal ligation and puncture mediated) endothelial glycocalyx degradation. We used mass spectrometry, surface plasmon resonance, and in vitro studies of human and mouse samples to determine the structure of HS fragments released during glycocalyx degradation and their impact on fibroblast growth factor receptor (FGFR) 1 signaling, a mediator of endothelial repair. Homeostatic pulmonary endothelial glycocalyx reconstitution occurred rapidly after nonseptic degradation and was associated with induction of the HS biosynthetic enzyme, exostosin (EXT)-1. In contrast, sepsis was characterized by loss of pulmonary EXT1 expression and delayed glycocalyx reconstitution. Rapid glycocalyx recovery after nonseptic degradation was dependent upon induction of FGFR1 expression and was augmented by FGF-promoting effects of circulating HS fragments released during glycocalyx degradation. Although sepsis-released HS fragments maintained this ability to activate FGFR1, sepsis was associated with the downstream absence of reparative pulmonary endothelial FGFR1 induction. Sepsis may cause vascular injury not only via glycocalyx degradation, but also by impairing FGFR1/EXT1–mediated glycocalyx reconstitution. PMID:28187268

The effects of anxiety and depression on stress-related growth among Chinese army recruits: Resilience and coping as mediators.

PubMed

Yu, Yongju; Peng, Li; Liu, Botao; Liu, Yunbo; Li, Min; Chen, Long; Xie, Junrun; Li, Jing; Li, Jiawen

2016-09-01

Stress-related growth can occur after various traumas or stressful events. In order to investigate how anxiety and depression relate to stress-related growth, this study was conducted with 443 Chinese army recruits who had just finished a 3-month recruit training program. Path analyses revealed that resilience and positive/negative coping partially mediated the effect of anxiety on perceived stress-related growth, while negative coping fully mediated the relationship between depression and perceived stress-related growth. Moreover, positive coping partially carried the influence of resilience on perceived stress-related growth. Anxiety and depression may be potential targets for intervention to enhance the development of stress-related growth among Chinese army recruits. © The Author(s) 2015.

Amplification of TLO Mediator Subunit Genes Facilitate Filamentous Growth in Candida Spp.

PubMed Central

Liu, Zhongle; Moran, Gary P.; Myers, Lawrence C.

2016-01-01

Filamentous growth is a hallmark of C. albicans pathogenicity compared to less-virulent ascomycetes. A multitude of transcription factors regulate filamentous growth in response to specific environmental cues. Our work, however, suggests the evolutionary history of C. albicans that resulted in its filamentous growth plasticity may be tied to a change in the general transcription machinery rather than transcription factors and their specific targets. A key genomic difference between C. albicans and its less-virulent relatives, including its closest relative C. dubliniensis, is the unique expansion of the TLO (TeLOmere-associated) gene family in C. albicans. Individual Tlo proteins are fungal-specific subunits of Mediator, a large multi-subunit eukaryotic transcriptional co-activator complex. This amplification results in a large pool of ‘free,’ non-Mediator associated, Tlo protein present in C. albicans, but not in C. dubliniensis or other ascomycetes with attenuated virulence. We show that engineering a large ‘free’ pool of the C. dubliniensis Tlo2 (CdTlo2) protein in C. dubliniensis, through overexpression, results in a number of filamentation phenotypes typically associated only with C. albicans. The amplitude of these phenotypes is proportional to the amount of overexpressed CdTlo2 protein. Overexpression of other C. dubliniensis and C. albicans Tlo proteins do result in these phenotypes. Tlo proteins and their orthologs contain a Mediator interaction domain, and a potent transcriptional activation domain. Nuclear localization of the CdTlo2 activation domain, facilitated naturally by the Tlo Mediator binding domain or artificially through an appended nuclear localization signal, is sufficient for the CdTlo2 overexpression phenotypes. A C. albicans med3 null mutant causes multiple defects including the inability to localize Tlo proteins to the nucleus and reduced virulence in a murine systemic infection model. Our data supports a model in which the

Amplification of TLO Mediator Subunit Genes Facilitate Filamentous Growth in Candida Spp.

PubMed

Liu, Zhongle; Moran, Gary P; Sullivan, Derek J; MacCallum, Donna M; Myers, Lawrence C

2016-10-01

Filamentous growth is a hallmark of C. albicans pathogenicity compared to less-virulent ascomycetes. A multitude of transcription factors regulate filamentous growth in response to specific environmental cues. Our work, however, suggests the evolutionary history of C. albicans that resulted in its filamentous growth plasticity may be tied to a change in the general transcription machinery rather than transcription factors and their specific targets. A key genomic difference between C. albicans and its less-virulent relatives, including its closest relative C. dubliniensis, is the unique expansion of the TLO (TeLOmere-associated) gene family in C. albicans. Individual Tlo proteins are fungal-specific subunits of Mediator, a large multi-subunit eukaryotic transcriptional co-activator complex. This amplification results in a large pool of 'free,' non-Mediator associated, Tlo protein present in C. albicans, but not in C. dubliniensis or other ascomycetes with attenuated virulence. We show that engineering a large 'free' pool of the C. dubliniensis Tlo2 (CdTlo2) protein in C. dubliniensis, through overexpression, results in a number of filamentation phenotypes typically associated only with C. albicans. The amplitude of these phenotypes is proportional to the amount of overexpressed CdTlo2 protein. Overexpression of other C. dubliniensis and C. albicans Tlo proteins do result in these phenotypes. Tlo proteins and their orthologs contain a Mediator interaction domain, and a potent transcriptional activation domain. Nuclear localization of the CdTlo2 activation domain, facilitated naturally by the Tlo Mediator binding domain or artificially through an appended nuclear localization signal, is sufficient for the CdTlo2 overexpression phenotypes. A C. albicans med3 null mutant causes multiple defects including the inability to localize Tlo proteins to the nucleus and reduced virulence in a murine systemic infection model. Our data supports a model in which the activation

Antisense oligonucleotide–mediated MDM4 exon 6 skipping impairs tumor growth

PubMed Central

Dewaele, Michael; Tabaglio, Tommaso; Willekens, Karen; Bezzi, Marco; Teo, Shun Xie; Low, Diana H.P.; Koh, Cheryl M.; Rambow, Florian; Fiers, Mark; Rogiers, Aljosja; Radaelli, Enrico; Al-Haddawi, Muthafar; Tan, Soo Yong; Hermans, Els; Amant, Frederic; Yan, Hualong; Lakshmanan, Manikandan; Koumar, Ratnacaram Chandrahas; Lim, Soon Thye; Derheimer, Frederick A.; Campbell, Robert M.; Bonday, Zahid; Tergaonkar, Vinay; Shackleton, Mark; Blattner, Christine; Marine, Jean-Christophe; Guccione, Ernesto

2015-01-01

MDM4 is a promising target for cancer therapy, as it is undetectable in most normal adult tissues but often upregulated in cancer cells to dampen p53 tumor-suppressor function. The mechanisms that underlie MDM4 upregulation in cancer cells are largely unknown. Here, we have shown that this key oncogenic event mainly depends on a specific alternative splicing switch. We determined that while a nonsense-mediated, decay-targeted isoform of MDM4 (MDM4-S) is produced in normal adult tissues as a result of exon 6 skipping, enhanced exon 6 inclusion leads to expression of full-length MDM4 in a large number of human cancers. Although this alternative splicing event is likely regulated by multiple splicing factors, we identified the SRSF3 oncoprotein as a key enhancer of exon 6 inclusion. In multiple human melanoma cell lines and in melanoma patient–derived xenograft (PDX) mouse models, antisense oligonucleotide–mediated (ASO-mediated) skipping of exon 6 decreased MDM4 abundance, inhibited melanoma growth, and enhanced sensitivity to MAPK-targeting therapeutics. Additionally, ASO-based MDM4 targeting reduced diffuse large B cell lymphoma PDX growth. As full-length MDM4 is enhanced in multiple human tumors, our data indicate that this strategy is applicable to a wide range of tumor types. We conclude that enhanced MDM4 exon 6 inclusion is a common oncogenic event and has potential as a clinically compatible therapeutic target. PMID:26595814

Hormone-Mediated Pattern Formation in Seedling of Plants: a Competitive Growth Dynamics Model

NASA Astrophysics Data System (ADS)

Kawaguchi, Satoshi; Mimura, Masayasu; Ohya, Tomoyuki; Oikawa, Noriko; Okabe, Hirotaka; Kai, Shoichi

2001-10-01

An ecologically relevant pattern formation process mediated by hormonal interactions among growing seedlings is modeled based on the experimental observations on the effects of indole acetic acid, which can act as an inhibitor and activator of root growth depending on its concentration. In the absence of any lateral root with constant hormone-sensitivity, the edge effect phenomenon is obtained depending on the secretion rate of hormone from the main root. Introduction of growth-stage-dependent hormone-sensitivity drastically amplifies the initial randomness, resulting in spatially irregular macroscopic patterns. When the lateral root growth is introduced, periodic patterns are obtained whose periodicity depends on the length of lateral roots. The growth-stage-dependent hormone-sensitivity and the lateral root growth are crucial for macroscopic periodic-pattern formation.

Integrin-Mediated Transforming Growth Factor-β Activation Regulates Homeostasis of the Pulmonary Epithelial-Mesenchymal Trophic Unit

PubMed Central

Araya, Jun; Cambier, Stephanie; Morris, Alanna; Finkbeiner, Walter; Nishimura, Stephen L.

2006-01-01

Trophic interactions between pulmonary epithelial and mesenchymal cell types, known as the epithelial-mesenchymal trophic unit (EMTU), are crucial in lung development and lung disease. Transforming growth factor (TGF)-β is a key factor in mediating these interactions, but it is expressed in a latent form that requires activation to be functional. Using intact fetal tracheal tissue and primary cultures of fetal tracheal epithelial cells and fibroblasts, we demonstrate that a subset of integrins, αvβ6 and αvβ8, are responsible for almost all of the TGF-β activation in the EMTU. Both αvβ8 and αvβ6 contribute to fetal tracheal epithelial activation of TGF-β, whereas only αvβ8 contributes to fetal tracheal fibroblast activation of TGF-β. Interestingly, fetal tracheal epithelial αvβ8-mediated TGF-β activation can be enhanced by phorbol esters, likely because of the increased activity of MT1-MMP, an essential co-factor in αvβ8-mediated activation of TGF-β. Autocrine αvβ8-mediated TGF-β activation by fetal tracheal fibroblasts results in suppression of both transcription and secretion of hepatocyte growth factor, which is sufficient to affect phosphorylation of the airway epithelial hepatocyte growth factor receptor, c-Met, as well as airway epithelial proliferation in a co-culture model of the EMTU. These findings elucidate the function and complex regulation of integrin-mediated activation of TGF-β within the EMTU. PMID:16877343

Integrin-mediated transforming growth factor-beta activation regulates homeostasis of the pulmonary epithelial-mesenchymal trophic unit.

PubMed

Araya, Jun; Cambier, Stephanie; Morris, Alanna; Finkbeiner, Walter; Nishimura, Stephen L

2006-08-01

Trophic interactions between pulmonary epithelial and mesenchymal cell types, known as the epithelial-mesenchymal trophic unit (EMTU), are crucial in lung development and lung disease. Transforming growth factor (TGF)-beta is a key factor in mediating these interactions, but it is expressed in a latent form that requires activation to be functional. Using intact fetal tracheal tissue and primary cultures of fetal tracheal epithelial cells and fibroblasts, we demonstrate that a subset of integrins, alpha(v)beta(6) and alpha(v)beta(8), are responsible for almost all of the TGF-beta activation in the EMTU. Both alpha(v)beta(8) and alpha(v)beta(6) contribute to fetal tracheal epithelial activation of TGF-beta, whereas only alpha(v)beta(8) contributes to fetal tracheal fibroblast activation of TGF-beta. Interestingly, fetal tracheal epithelial alpha(v)beta(8)-mediated TGF-beta activation can be enhanced by phorbol esters, likely because of the increased activity of MT1-MMP, an essential co-factor in alpha(v)beta(8)-mediated activation of TGF-beta. Autocrine alpha(v)beta(8)-mediated TGF-beta activation by fetal tracheal fibroblasts results in suppression of both transcription and secretion of hepatocyte growth factor, which is sufficient to affect phosphorylation of the airway epithelial hepatocyte growth factor receptor, c-Met, as well as airway epithelial proliferation in a co-culture model of the EMTU. These findings elucidate the function and complex regulation of integrin-mediated activation of TGF-beta within the EMTU.

Adeno-associated virus type 2 rep gene-mediated inhibition of basal gene expression of human immunodeficiency virus type 1 involves its negative regulatory functions.

PubMed Central

Oelze, I; Rittner, K; Sczakiel, G

1994-01-01

Adeno-associated virus type 2 (AAV-2), a human parvovirus which is apathogenic in adults, inhibits replication and gene expression of human immunodeficiency virus type 1 (HIV-1) in human cells. The rep gene of AAV-2, which was shown earlier to be sufficient for this negative interference, also down-regulated the expression of heterologous sequences driven by the long terminal repeat (LTR) of HIV-1. This effect was observed in the absence of the HIV-1 transactivator Tat, i.e., at basal levels of LTR-driven transcription. In this work, we studied the involvement of functional subsequences of the HIV-1 LTR in rep-mediated inhibition in the absence of Tat. Mutated LTRs driving an indicator gene (cat) were cointroduced into human SW480 cells together with rep alone or with double-stranded DNA fragments or RNA containing sequences of the HIV-1 LTR. The results indicate that rep strongly enhances the function of negative regulatory elements of the LTR. In addition, the experiments revealed a transcribed sequence element located within the TAR-coding sequence termed AHHH (AAV-HIV homology element derived from HIV-1) which is involved in rep-mediated inhibition. The AHHH element is also involved in down-regulation of basal expression levels in the absence of rep, suggesting that AHHH also contributes to negative regulatory functions of the LTR of HIV-1. In contrast, positive regulatory elements of the HIV-1 LTR such as the NF kappa B and SP1 binding sites have no significant influence on the rep-mediated inhibition. Images PMID:8289357

Insect growth regulatory activity of Vitex trifolia and Vitex agnus-castus essential oils against Spilosoma obliqua.

PubMed

Tandon, Shishir; Mittal, Ashutosh K; Pant, A K

2008-06-01

Essential oils of Vitex trifolia and Vitex agnus-castus were evaluated against Vth instar larvae of Spilosoma obliqua, when applied topically on the dorsal side of mesothoracic region, for insect growth regulatory activity. This treatment caused extended larval period and pupal period, increase in larval mortality and adult deformity and decrease in adult emergence, fecundity of female and egg fertility of test insect.

Diet and Energy-Sensing Inputs Affect TorC1-Mediated Axon Misrouting but Not TorC2-Directed Synapse Growth in a Drosophila Model of Tuberous Sclerosis

PubMed Central

Dimitroff, Brian; Lee, Hyun-Gwan; Zhao, Na; O'Connor, Michael B.; Neufeld, Thomas P.; Selleck, Scott B.

2012-01-01

The Target of Rapamycin (TOR) growth regulatory system is influenced by a number of different inputs, including growth factor signaling, nutrient availability, and cellular energy levels. While the effects of TOR on cell and organismal growth have been well characterized, this pathway also has profound effects on neural development and behavior. Hyperactivation of the TOR pathway by mutations in the upstream TOR inhibitors TSC1 (tuberous sclerosis complex 1) or TSC2 promotes benign tumors and neurological and behavioral deficits, a syndrome known as tuberous sclerosis (TS). In Drosophila, neuron-specific overexpression of Rheb, the direct downstream target inhibited by Tsc1/Tsc2, produced significant synapse overgrowth, axon misrouting, and phototaxis deficits. To understand how misregulation of Tor signaling affects neural and behavioral development, we examined the influence of growth factor, nutrient, and energy sensing inputs on these neurodevelopmental phenotypes. Neural expression of Pi3K, a principal mediator of growth factor inputs to Tor, caused synapse overgrowth similar to Rheb, but did not disrupt axon guidance or phototaxis. Dietary restriction rescued Rheb-mediated behavioral and axon guidance deficits, as did overexpression of AMPK, a component of the cellular energy sensing pathway, but neither was able to rescue synapse overgrowth. While axon guidance and behavioral phenotypes were affected by altering the function of a Tor complex 1 (TorC1) component, Raptor, or a TORC1 downstream element (S6k), synapse overgrowth was only suppressed by reducing the function of Tor complex 2 (TorC2) components (Rictor, Sin1). These findings demonstrate that different inputs to Tor signaling have distinct activities in nervous system development, and that Tor provides an important connection between nutrient-energy sensing systems and patterning of the nervous system. PMID:22319582

Photoperiod- and temperature-mediated control of growth cessation and dormancy in trees: a molecular perspective.

PubMed

Maurya, Jay P; Bhalerao, Rishikesh P

2017-09-01

How plants adapt their developmental patterns to regular seasonal changes is an important question in biology. The annual growth cycle in perennial long-lived trees is yet another example of how plants can adapt to seasonal changes. The two main signals that plants rely on to respond to seasonal changes are photoperiod and temperature, and these signals have critical roles in the temporal regulation of the annual growth cycle of trees. This review presents the latest findings to provide insight into the molecular mechanisms that underlie how photoperiodic and temperature signals regulate seasonal growth in trees. The results point to a high level of conservation in the signalling pathways that mediate photoperiodic control of seasonal growth in trees and flowering in annual plants such as arabidopsis. Furthermore, the data indicate that symplastic communication may mediate certain aspects of seasonal growth. Although considerable insight into the control of phenology in model plants such as poplar and spruce has been obtained, the future challenge is extending these studies to other, non-model trees. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Webinar Presentation: Exposures to Polycyclic Aromatic Hydrocarbons and Childhood Growth Trajectories and Body Composition: Linkages to Disrupted Self-Regulatory Processes

EPA Pesticide Factsheets

This presentation, Exposures to Polycyclic Aromatic Hydrocarbons and Childhood Growth Trajectories and Body Composition: Linkages to Disrupted Self-Regulatory Processes, was given at the NIEHS/EPA Children's Centers 2016 Webinar Series: Childhood Obesity

Ethylene Mediates Alkaline-Induced Rice Growth Inhibition by Negatively Regulating Plasma Membrane H+-ATPase Activity in Roots

PubMed Central

Chen, Haifei; Zhang, Quan; Cai, Hongmei; Xu, Fangsen

2017-01-01

pH is an important factor regulating plant growth. Here, we found that rice was better adapted to low pH than alkaline conditions, as its growth was severely inhibited at high pH, with shorter root length and an extreme biomass reduction. Under alkaline stress, the expression of genes for ethylene biosynthesis enzymes in rice roots was strongly induced by high pH and exogenous ethylene precursor ACC and ethylene overproduction in etol1-1 mutant aggravated the alkaline stress-mediated inhibition of rice growth, especially for the root elongation with decreased cell length in root apical regions. Conversely, the ethylene perception antagonist silver (Ag+) and ein2-1 mutants could partly alleviate the alkaline-induced root elongation inhibition. The H+-ATPase activity was extremely inhibited by alkaline stress and exogenous ACC. However, the H+-ATPase-mediated rhizosphere acidification was enhanced by exogenous Ag+, while H+ efflux on the root surface was extremely inhibited by exogenous ACC, suggesting that ethylene negatively regulated H+-ATPase activity under high-pH stress. Our results demonstrate that H+-ATPase is involved in ethylene-mediated inhibition of rice growth under alkaline stress. PMID:29114258

ResDE Two-Component Regulatory System Mediates Oxygen Limitation-Induced Biofilm Formation by Bacillus amyloliquefaciens SQR9.

PubMed

Zhou, Xuan; Zhang, Nan; Xia, Liming; Li, Qing; Shao, Jiahui; Shen, Qirong; Zhang, Ruifu

2018-04-15

Efficient biofilm formation and root colonization capabilities facilitate the ability of beneficial plant rhizobacteria to promote plant growth and antagonize soilborne pathogens. Biofilm formation by plant-beneficial Bacillus strains is triggered by environmental cues, including oxygen deficiency, but the pathways that sense these environmental signals and regulate biofilm formation have not been thoroughly elucidated. In this study, we showed that the ResDE two-component regulatory system in the plant growth-promoting rhizobacterium Bacillus amyloliquefaciens strain SQR9 senses the oxygen deficiency signal and regulates biofilm formation. ResE is activated by sensing the oxygen limitation-induced reduction of the NAD + /NADH pool through its PAS domain, stimulating its kinase activity, and resulting in the transfer of a phosphoryl group to ResD. The phosphorylated ResD directly binds to the promoter regions of the qoxABCD and ctaCDEF operons to improve the biosynthesis of terminal oxidases, which can interact with KinB to activate biofilm formation. These results not only revealed the novel regulatory function of the ResDE two-component system but also contributed to the understanding of the complicated regulatory network governing Bacillus biofilm formation. This research may help to enhance the root colonization and the plant-beneficial efficiency of SQR9 and other Bacillus rhizobacteria used in agriculture. IMPORTANCE Bacillus spp. are widely used as bioinoculants for plant growth promotion and disease suppression. The exertion of their plant-beneficial functions is largely dependent on their root colonization, which is closely related to their biofilm formation capabilities. On the other hand, Bacillus is the model bacterium for biofilm study, and the process and molecular network of biofilm formation are well characterized (B. Mielich-Süss and D. Lopez, Environ Microbiol 17:555-565, 2015, https://doi.org/10.1111/1462-2920.12527; L. S. Cairns, L. Hobley, and

Regulatory T cells: mechanisms of differentiation and function.

PubMed

Josefowicz, Steven Z; Lu, Li-Fan; Rudensky, Alexander Y

2012-01-01

The immune system has evolved to mount an effective defense against pathogens and to minimize deleterious immune-mediated inflammation caused by commensal microorganisms, immune responses against self and environmental antigens, and metabolic inflammatory disorders. Regulatory T (Treg) cell-mediated suppression serves as a vital mechanism of negative regulation of immune-mediated inflammation and features prominently in autoimmune and autoinflammatory disorders, allergy, acute and chronic infections, cancer, and metabolic inflammation. The discovery that Foxp3 is the transcription factor that specifies the Treg cell lineage facilitated recent progress in understanding the biology of regulatory T cells. In this review, we discuss cellular and molecular mechanisms in the differentiation and function of these cells.

Maternal care mediates the effects of nutrition and responsive stimulation interventions on young children's growth.

PubMed

Brown, N; Finch, J E; Obradović, J; Yousafzai, A K

2017-07-01

Undernutrition contributes to at least half the estimated six million annual childhood deaths worldwide. Furthermore, one in three children fails to meet their developmental potential because of risks including stunting, illness, under-stimulation, poor responsive interactions and maternal depressive symptoms. Our study investigates the role of caregiving processes on children's height-for-age at 2 and 4 years. The Pakistan Early Child Development Scale-up study assessed the longitudinal effectiveness of early nutrition and responsive stimulation interventions on growth and development at 4 years of age. In total, 1302 children were followed up from birth to 4 years. We leveraged path analyses to explore potential mediators of early intervention effects on children's height-for-age at 4 years, including maternal depressive symptoms, mother-child interaction quality, diarrhoeal illness and height-for-age at 2 years. Our final model had excellent model fit (comparative fix index = 0.999, Tucker-Lewis index = 0.998, root mean square error of approximation = 0.008) and showed that mother-child interaction quality mediated the effects of both enhanced nutrition and responsive stimulation interventions on height-for-age at 4 years via its longitudinal stability from 2 years of age (β = 0.016, p = 0.005; β = 0.048, p < 0.001, respectively). Further, diarrhoeal illness mediated the effects of maternal depressive symptoms at 1 year post partum on children's height-for-age at 4 years via the longitudinal stability of height-for-age z-score from 2 years of age onwards (β = -0.007, p = 0.019). The quality of early caregiving experience mediated the association between both interventions and height-for-age. The effect of maternal depressive symptoms on growth was mediated by diarrhoeal illness. Programmatic approaches to child nutrition and growth must address all these potentially modifiable factors. © 2017 John Wiley & Sons Ltd.

Analysis of a Gene Regulatory Cascade Mediating Circadian Rhythm in Zebrafish

PubMed Central

Wang, Haifang; Du, Jiulin; Yan, Jun

2013-01-01

In the study of circadian rhythms, it has been a puzzle how a limited number of circadian clock genes can control diverse aspects of physiology. Here we investigate circadian gene expression genome-wide using larval zebrafish as a model system. We made use of a spatial gene expression atlas to investigate the expression of circadian genes in various tissues and cell types. Comparison of genome-wide circadian gene expression data between zebrafish and mouse revealed a nearly anti-phase relationship and allowed us to detect novel evolutionarily conserved circadian genes in vertebrates. We identified three groups of zebrafish genes with distinct responses to light entrainment: fast light-induced genes, slow light-induced genes, and dark-induced genes. Our computational analysis of the circadian gene regulatory network revealed several transcription factors (TFs) involved in diverse aspects of circadian physiology through transcriptional cascade. Of these, microphthalmia-associated transcription factor a (mitfa), a dark-induced TF, mediates a circadian rhythm of melanin synthesis, which may be involved in zebrafish's adaptation to daily light cycling. Our study describes a systematic method to discover previously unidentified TFs involved in circadian physiology in complex organisms. PMID:23468616

Beta-type transforming growth factor specifies organizational behavior in vascular smooth muscle cell cultures

PubMed Central

1987-01-01

In culture, vascular smooth muscle cells (SMC) grow in a "hill-and- valley" (multilayered) pattern of organization. We have studied the growth, behavioral organization, and biosynthetic phenotype of rat aortic SMC exposed to purified platelet-derived growth regulatory molecules. We show that multilayered growth is not a constitutive feature of cultured SMC, and that beta-type transforming growth factor (TGF-beta) is the primary determinant of multilayered growth and the hill-and-valley pattern of organization diagnostic for SMC in culture. TGF-beta inhibited, in a dose-dependent manner, the serum- or platelet- derived growth factor-mediated proliferation of these cells in two- dimensional culture, but only when cells were plated at subconfluent densities. The ability of TGF-beta to inhibit SMC growth was inversely correlated to plating cell density. When SMC were plated at monolayer density (5 X 10(4) cells/cm2) to allow maximal cell-to-cell contact, TGF-beta potentiated cell growth. This differential response of SMC to TGF-beta may contribute to the hill-and-valley pattern of organization. Unlike its effect on other cell types, TGF-beta did not enhance the synthesis of fibronectin or its incorporation into the extracellular matrix. However, the synthesis of a number of other secreted proteins was altered by TGF-beta treatment. SMC treated with TGF-beta for 4 or 8 h secreted markedly enhanced amounts of an Mr 38,000-D protein doublet whose synthesis is known to be increased by heparin (another inhibitor of SMC growth), suggesting metabolic similarities between heparin- and TGF-beta-mediated SMC growth inhibition. The data suggest that TGF-beta may play an important and complex regulatory role in SMC proliferation and organization during development and after vascular injury. PMID:3475277

Regulatory T cells in atherosclerosis: critical immune regulatory function and therapeutic potential.

PubMed

Spitz, Charlotte; Winkels, Holger; Bürger, Christina; Weber, Christian; Lutgens, Esther; Hansson, Göran K; Gerdes, Norbert

2016-03-01

Atherosclerosis is a chronic inflammatory disease that is mediated by innate and adaptive immune responses. The disease is characterized by sub-endothelial accumulation and modification of lipids in the artery wall triggering an inflammatory reaction which promotes lesion progression and eventual plaque rupture, thrombus formation, and the respective clinical sequelae such as myocardial infarction or stroke. During the past decade, T-cell-mediated immune responses, especially control of pro-inflammatory signals by regulatory T cells (Tregs), have increasingly attracted the interest of experimental and clinical researchers. By suppression of T cell proliferation and secretion of anti-inflammatory cytokines, such as interleukin-10 (IL-10) and transforming growth factor-β, Tregs exert their atheroprotective properties. Atherosclerosis-prone, hyperlipidemic mice harbor systemically less Tregs compared to wild-type mice, suggesting an imbalance of immune cells which affects local and systemic inflammatory and potentially metabolic processes leading to atherogenesis. Restoring or increasing Treg frequency and enhancing their suppressive capacity by various modulations may pose a promising approach for treating inflammatory conditions such as cardiovascular diseases. In this review, we briefly summarize the immunological basics of atherosclerosis and introduce the role and contribution of different subsets of T cells. We then discuss experimental data and current knowledge pertaining to Tregs in atherosclerosis and perspectives on manipulating the adaptive immune system to alleviate atherosclerosis and cardiovascular disease.

Plasticity and innovation of regulatory mechanisms underlying seed oil content mediated by duplicated genes in the palaeopolyploid soybean.

PubMed

Zhang, Dajian; Zhao, Meixia; Li, Shuai; Sun, Lianjun; Wang, Weidong; Cai, Chunmei; Dierking, Emily C; Ma, Jianxin

2017-06-01

Many plants have undergone whole genome duplication (WGD). However, how regulatory networks underlying a particular trait are reshaped in polyploids has not been experimentally investigated. Here we show that the regulatory pathways modulating seed oil content, which involve WRINKLED1 (WRI1), LEAFY COTYLEDON1 (LEC1), and LEC2 in Arabidopsis, have been modified in the palaeopolyploid soybean. Such modifications include functional reduction of GmWRI1b of the GmWRI1a/GmWRI1b homoeologous pair relevant to WRI1, complementary non-allelic dosage effects of the GmLEC1a/GmLEC1b homoeologous pair relevant to LEC1, pseudogenization of the singleton GmLEC2 relevant to LEC2, and the rise of the LEC2-like function of GmABI3b, contrasting to its homoeolog GmABI3a, which maintains the ABSCISIC ACID INSENSITIVE 3 (ABI3)-like function in modulating seed maturation and dormancy. The function of GmABI3b in modulating seed oil biosynthesis was fulfilled by direct binding to a RY (CATGCA) cis-regulatory element in the GmWRI1a promoter, which was absent in the GmWRI1b promoter, resulting in reduction of the GmWRI1b expression. Nevertheless, the three regulators each exhibited similar intensities of purifying selection to their respective duplicates since these pairs were formed by a WGD event that is proposed to have occurred approximately 13 million years ago (mya), suggesting that the differentiation in spatiotemporal expression between the duplicated genes is more likely to be the outcome of neutral variation in regulatory sequences. This study thus exemplifies the plasticity, dynamics, and novelty of regulatory networks mediated by WGD. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Intrauterine growth restriction and prematurity influence regulatory T cell development in newborns.

PubMed

Mukhopadhyay, Dhriti; Weaver, Laura; Tobin, Richard; Henderson, Stephanie; Beeram, Madhava; Newell-Rogers, M Karen; Perger, Lena

2014-05-01

The aim of this study was to determine the relationship of birth weight and gestational age with regulatory T cells (Tregs) in cord blood of human newborns. Cord blood mononuclear cells (CBMCs) of 210 newborns were analyzed using flow cytometry to identify Tregs (CD3(+), CD4(+), CD25(high), FoxP3(high)) and measure FoxP3 mean fluorescence intensity (MFI). Suppressive index (SI) was calculated as FoxP3 MFI per Treg. Mode of delivery had no significant effect on Tregs at birth. Term babies with growth restriction had fewer Tregs than their appropriate weight counterparts but equivalent SI. Preterm babies had higher percentages of Tregs, but lower SI than term controls. SI steadily increased through gestation. Intrauterine growth restriction is correlated with fewer circulating Tregs and prematurity with decreased functionality of Tregs compared to term appropriate weight infants. This may have implications in diseases such as necrotizing enterocolitis that disproportionately affect premature and lower birth weight infants. Copyright © 2014 Elsevier Inc. All rights reserved.

Polymer-mediated growth of crystals and mesocrystals.

PubMed

Cölfen, Helmut

2013-01-01

Polymers are important additives for the control of mineralization reactions in both biological and bioinspired mineralization. The reason is that they allow for a number of interactions with the growing crystals and even amorphous minerals. These can substantially influence the way the mineral grows on several levels. Already in the prenucleation phase, polymers can control the formation of prenucleation clusters and subsequently the nucleation event. Also, polymers can control whether the further crystallization follows a classical or nonclassical particle-mediated growth path. In this chapter, the main ways in which polymers can be used to control a crystallization reaction will be highlighted. In addition, polymers that are useful for this purpose and the experimental conditions suitable for directing a crystallization reaction into the desired direction through the use of polymers will be described. © 2013 Elsevier Inc. All rights reserved.

Personality and Post-traumatic Growth of Adolescents 42 Months after the Wenchuan Earthquake: A Mediated Model.

PubMed

An, Yuanyuan; Ding, Xu; Fu, Fang

2017-01-01

The aim of this study was to examine the relationship of teenagers' post-traumatic growth (PTG) and personality and coping style by developing a mediating model with matched data from 772 adolescents. The sample consisted of 772 adolescents (mean age = 12.93, SD = 1.80) from several middle schools located in the areas that were most severely affected by the earthquake. Five factor model of personality, Coping Style Scale and Post-traumatic Growth Inventory were used to measure personality, coping and PTG of adolescents respectively. The results showed that the mean of PTG is 2.87 ( SD = 0.93). Moreover, the relationship between personality and PTG is mediated by cognitive coping. The model's fit indices indicated a good fit (CFI = 0.996, TLI = 0.962, NFI = 0.994, RMSEA = 0.055). Results showed that a positive cognition coping style mediated the relationship between personality and PTG.

Role of Rho/ROCK and p38 MAP kinase pathways in transforming growth factor-beta-mediated Smad-dependent growth inhibition of human breast carcinoma cells in vivo.

PubMed

Kamaraju, Anil K; Roberts, Anita B

2005-01-14

TGF-beta is a multifunctional cytokine known to exert its biological effects through a variety of signaling pathways of which Smad signaling is considered to be the main mediator. At present, the Smad-independent pathways, their interactions with each other, and their roles in TGF-beta-mediated growth inhibitory effects are not well understood. To address these questions, we have utilized a human breast cancer cell line MCF10CA1h and demonstrate that p38 MAP kinase and Rho/ROCK pathways together with Smad2 and Smad3 are necessary for TGF-beta-mediated growth inhibition of this cell line. We show that Smad2/3 are indispensable for TGF-beta-mediated growth inhibition, and that both p38 and Rho/ROCK pathways affect the linker region phosphorylation of Smad2/3. Further, by using Smad3 mutated at the putative phosphorylation sites in the linker region, we demonstrate that phosphorylation at Ser203 and Ser207 residues is required for the full transactivation potential of Smad3, and that these residues are targets of the p38 and Rho/ROCK pathways. We demonstrate that activation of the p38 MAP kinase pathway is necessary for the full transcriptional activation potential of Smad2/Smad3 by TGF-beta, whereas activity of Rho/ROCK is necessary for both down-regulation of c-Myc protein and up-regulation of p21waf1 protein, directly interfering with p21waf1 transcription. Our results not only implicate Rho/ROCK and p38 MAPK pathways as necessary for TGF-beta-mediated growth inhibition, but also demonstrate their individual contributions and the basis for their cooperation with each other.

The molecular mechanism of mediation of adsorbed serum proteins to endothelial cells adhesion and growth on biomaterials.

PubMed

Yang, Dayun; Lü, Xiaoying; Hong, Ying; Xi, Tingfei; Zhang, Deyuan

2013-07-01

To explore molecular mechanism of mediation of adsorbed proteins to cell adhesion and growth on biomaterials, this study examined endothelial cell adhesion, morphology and viability on bare and titanium nitride (TiN) coated nickel titanium (NiTi) alloys and chitosan film firstly, and then identified the type and amount of serum proteins adsorbed on the three surfaces by proteomic technology. Subsequently, the mediation role of the identified proteins to cell adhesion and growth was investigated with bioinformatics analyses, and further confirmed by a series of cellular and molecular biological experiments. Results showed that the type and amount of adsorbed serum proteins associated with cell adhesion and growth was obviously higher on the alloys than on the chitosan film, and these proteins mediated endothelial cell adhesion and growth on the alloys via four ways. First, proteins such as adiponectin in the adsorbed protein layer bound with cell surface receptors to generate signal transduction, which activated cell surface integrins through increasing intracellular calcium level. Another way, thrombospondin 1 in the adsorbed protein layer promoted TGF-β signaling pathway activation and enhanced integrins expression. The third, RGD sequence containing proteins such as fibronectin 1, vitronectin and thrombospondin 1 in the adsorbed protein layer bound with activated integrins to activate focal adhesion pathway, increased focal adhesion formation and actin cytoskeleton organization and mediated cell adhesion and spreading. In addition, the activated focal adhesion pathway promoted the expression of cell growth related genes and resulted in cell proliferation. The fourth route, coagulation factor II (F2) and fibronectin 1 in the adsorbed protein layer bound with cell surface F2 receptor and integrin, activated regulation of actin cytoskeleton pathway and regulated actin cytoskeleton organization. Copyright © 2013 Elsevier Ltd. All rights reserved.

Induction of regulatory cells by helminth parasites: exploitation for the treatment of inflammatory diseases.

PubMed

Finlay, Conor M; Walsh, Kevin P; Mills, Kingston H G

2014-05-01

Helminth parasites are highly successful pathogens, chronically infecting a quarter of the world's population, causing significant morbidity but rarely causing death. Protective immunity and expulsion of helminths is mediated by T-helper 2 (Th2) cells, type 2 (M2) macrophages, type 2 innate lymphoid cells, and eosinophils. Failure to mount these type 2 immune responses can result in immunopathology mediated by Th1 or Th17 cells. Helminths have evolved a wide variety of approaches for immune suppression, especially the generation of regulatory T cells and anti-inflammatory cytokines interleukin-10 and transforming growth factor-β. This is a very effective strategy for subverting protective immune responses to prolong their survival in the host but has the bystander effect of modulating immune responses to unrelated antigens. Epidemiological studies in humans have shown that infection with helminth parasites is associated with a low incidence of allergy/asthma and autoimmunity in developing countries. Experimental studies in mice have demonstrated that regulatory immune responses induced by helminth can suppress Th2 and Th1/Th17 responses that mediate allergy and autoimmunity, respectively. This has provided a rational explanation of the 'hygiene hypothesis' and has also led to the exploitation of helminths or their immunomodulatory products in the development of new immunosuppressive therapies for inflammatory diseases in humans. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Aldosterone mediates its rapid effects in vascular endothelial cells through GPER activation.

PubMed

Gros, Robert; Ding, Qingming; Liu, Bonan; Chorazyczewski, Jozef; Feldman, Ross D

2013-03-01

The importance of the rapid vascular effects of aldosterone is increasingly appreciated. Through these rapid pathways, aldosterone has been shown to regulate vascular contractility, cell growth, and apoptosis. In our most recent studies, we demonstrated the effects of aldosterone on cell growth and contractility in vascular smooth muscle cells. We showed that these effects could occur via activation of the classic mineralocorticoid receptor, as well the recently characterized G protein-coupled estrogen receptor (GPER), initially characterized as an estrogen-specific receptor. However, the mechanisms underlying aldosterone's endothelium-dependent actions are unknown. Furthermore, the ERK regulatory and proapoptotic effects of aldosterone mediated by GPER activation in cultured vascular smooth muscle cells were only apparent when GPER was reintroduced into these cells by gene transfer. Whether GPER activation via aldosterone might be an important regulator in native vascular cells has been questioned. Therefore, to determine the role of GPER in mediating aldosterone's effects on cell growth and vascular reactivity in native cells, we examined rat aortic vascular endothelial cells, a model characterized by persistent robust expression of GPER, but without detectable mineralocorticoid receptor expression. In these endothelial cells, the GPER agonist G1 mediates a rapid increase in ERK phosphorylation that is wholly GPER-dependent, paralleling the actions of aldosterone. The effects of G1 and aldosterone to stimulate ERK phosphorylation paralleled their proapoptotic and antiproliferative effects. In previous studies, we reported that aldosterone mediates a rapid endothelium-dependent vasodilatory effect, antagonistic to its direct vasoconstrictor effect in endothelium-denuded preparations. Using a rat aortic ring/organ bath preparation to determine the GPER dependence of aldosterone's endothelium-dependent vasodilator effects, we demonstrate that aldosterone inhibits

A role for small RNA in regulating innate immunity during plant growth

PubMed Central

Deng, Yingtian; Wang, Jubin; Tung, Jeffrey; Liu, Dan; Zhou, Yingjia; He, Shuang; Baker, Barbara

2018-01-01

Plant genomes encode large numbers of nucleotide-binding (NB) leucine-rich repeat (LRR) immune receptors (NLR) that mediate effector triggered immunity (ETI) and play key roles in protecting crops from diseases caused by devastating pathogens. Fitness costs are associated with plant NLR genes and regulation of NLR genes by micro(mi)RNAs and phased small interfering RNAs (phasiRNA) is proposed as a mechanism for reducing these fitness costs. However, whether NLR expression and NLR-mediated immunity are regulated during plant growth is unclear. We conducted genome-wide transcriptome analysis and showed that NLR expression gradually increased while expression of their regulatory small RNAs (sRNA) gradually decreased as plants matured, indicating that sRNAs could play a role in regulating NLR expression during plant growth. We further tested the role of miRNA in the growth regulation of NLRs using the tobacco mosaic virus (TMV) resistance gene N, which was targeted by miR6019 and miR6020. We showed that N-mediated resistance to TMV effectively restricted this virus to the infected leaves of 6-week old plants, whereas TMV infection was lethal in 1- and 3-week old seedlings due to virus-induced systemic necrosis. We further found that N transcript levels gradually increased while miR6019 levels gradually decreased during seedling maturation that occurs in the weeks after germination. Analyses of reporter genes in transgenic plants showed that growth regulation of N expression was post-transcriptionally mediated by MIR6019/6020 whereas MIR6019/6020 was regulated at the transcriptional level during plant growth. TMV infection of MIR6019/6020 transgenic plants indicated a key role for miR6019-triggered phasiRNA production for regulation of N-mediated immunity. Together our results demonstrate a mechanistic role for miRNAs in regulating innate immunity during plant growth. PMID:29293695

PAH1-encoded Phosphatidate Phosphatase Plays a Role in the Growth Phase- and Inositol-mediated Regulation of Lipid Synthesis in Saccharomyces cerevisiae*

PubMed Central

Pascual, Florencia; Soto-Cardalda, Aníbal; Carman, George M.

2013-01-01

In the yeast Saccharomyces cerevisiae, the synthesis of phospholipids in the exponential phase of growth occurs at the expense of the storage lipid triacylglycerol. As exponential phase cells progress into the stationary phase, the synthesis of triacylglycerol occurs at the expense of phospholipids. Early work indicates a role of the phosphatidate phosphatase (PAP) in this metabolism; the enzyme produces the diacylglycerol needed for the synthesis of triacylglycerol and simultaneously controls the level of phosphatidate for the synthesis of phospholipids. Four genes (APP1, DPP1, LPP1, and PAH1) encode PAP activity in yeast, and it has been unclear which gene is responsible for the synthesis of triacylglycerol throughout growth. An analysis of lipid synthesis and composition, as well as PAP activity in various PAP mutant strains, showed the essential role of PAH1 in triacylglycerol synthesis throughout growth. Pah1p is a phosphorylated enzyme whose in vivo function is dependent on its dephosphorylation by the Nem1p-Spo7p protein phosphatase complex. nem1Δ mutant cells exhibited defects in triacylglycerol synthesis and lipid metabolism that mirrored those imparted by the pah1Δ mutation, substantiating the importance of Pah1p dephosphorylation throughout growth. An analysis of cells bearing PPAH1-lacZ and PPAH1-DPP1 reporter genes showed that PAH1 expression was induced throughout growth and that the induction in the stationary phase was stimulated by inositol supplementation. A mutant analysis indicated that the Ino2p/Ino4p/Opi1p regulatory circuit and transcription factors Gis1p and Rph1p mediated this regulation. PMID:24196957

Analysis of tomato plasma membrane H(+)-ATPase gene family suggests a mycorrhiza-mediated regulatory mechanism conserved in diverse plant species.

PubMed

Liu, Junli; Liu, Jianjian; Chen, Aiqun; Ji, Minjie; Chen, Jiadong; Yang, Xiaofeng; Gu, Mian; Qu, Hongye; Xu, Guohua

2016-10-01

In plants, the plasma membrane H(+)-ATPase (HA) is considered to play a crucial role in regulating plant growth and respoding to environment stresses. Multiple paralogous genes encoding different isozymes of HA have been identified and characterized in several model plants, while limited information of the HA gene family is available to date for tomato. Here, we describe the molecular and expression features of eight HA-encoding genes (SlHA1-8) from tomato. All these genes are interrupted by multiple introns with conserved positions. SlHA1, 2, and 4 were widely expressed in all tissues, while SlHA5, 6, and 7 were almost only expressed in flowers. SlHA8, the transcripts of which were barely detectable under normal or nutrient-/salt-stress growth conditions, was strongly activated in arbuscular mycorrhizal (AM) fungal-colonized roots. Extreme lack of SlHA8 expression in M161, a mutant defective to AM fungal colonization, provided genetic evidence towards the dependence of its expression on AM symbiosis. A 1521-bp SlHA8 promoter could direct the GUS reporter expression specifically in colonized cells of transgenic tobacco, soybean, and rice mycorrhizal roots. Promoter deletion assay revealed a 223-bp promoter fragment of SlHA8 containing a variant of AM-specific cis-element MYCS (vMYCS) sufficient to confer the AM-induced activity. Targeted deletion of this motif in the corresponding promoter region causes complete abolishment of GUS staining in mycorrhizal roots. Together, these results lend cogent evidence towards the evolutionary conservation of a potential regulatory mechanism mediating the activation of AM-responsive HA genes in diverse mycorrhizal plant species.

Platelet-derived growth factor-receptor alpha strongly inhibits melanoma growth in vitro and in vivo.

PubMed

Faraone, Debora; Aguzzi, Maria Simona; Toietta, Gabriele; Facchiano, Angelo M; Facchiano, Francesco; Magenta, Alessandra; Martelli, Fabio; Truffa, Silvia; Cesareo, Eleonora; Ribatti, Domenico; Capogrossi, Maurizio C; Facchiano, Antonio

2009-08-01

Cutaneous melanoma is the most aggressive skin cancer; it is highly metastatic and responds poorly to current therapies. The expression of platelet-derived growth factor receptors (PDGF-Rs) is reported to be reduced in metastatic melanoma compared with benign nevi or normal skin; we then hypothesized that PDGF-Ralpha may control growth of melanoma cells. We show here that melanoma cells overexpressing PDGF-Ralpha respond to serum with a significantly lower proliferation compared with that of controls. Apoptosis, cell cycle arrest, pRb dephosphorylation, and DNA synthesis inhibition were also observed in cells overexpressing PDGF-Ralpha. Proliferation was rescued by PDGF-Ralpha inhibitors, allowing to exclude nonspecific toxic effects and indicating that PDGF-Ralpha mediates autocrine antiproliferation signals in melanoma cells. Accordingly, PDGF-Ralpha was found to mediate staurosporine cytotoxicity. A protein array-based analysis of the mitogen-activated protein kinase pathway revealed that melanoma cells overexpressing PDGF-Ralpha show a strong reduction of c-Jun phosphorylated in serine 63 and of protein phosphatase 2A/Balpha and a marked increase of p38gamma, mitogen-activated protein kinase kinase 3, and signal regulatory protein alpha1 protein expression. In a mouse model of primary melanoma growth, infection with the Ad-vector overexpressing PDGF-Ralpha reached a significant 70% inhibition of primary melanoma growth (P < .001) and a similar inhibition of tumor angiogenesis. All together, these data demonstrate that PDGF-Ralpha strongly impairs melanoma growth likely through autocrine mechanisms and indicate a novel endogenous mechanism involved in melanoma control.

Phosphoproteomics Reveals Regulatory T Cell-Mediated DEF6 Dephosphorylation That Affects Cytokine Expression in Human Conventional T Cells

PubMed Central

Joshi, Rubin N.; Binai, Nadine A.; Marabita, Francesco; Sui, Zhenhua; Altman, Amnon; Heck, Albert J. R.; Tegnér, Jesper; Schmidt, Angelika

2017-01-01

Regulatory T cells (Tregs) control key events of immune tolerance, primarily by suppression of effector T cells. We previously revealed that Tregs rapidly suppress T cell receptor (TCR)-induced calcium store depletion in conventional CD4+CD25− T cells (Tcons) independently of IP3 levels, consequently inhibiting NFAT signaling and effector cytokine expression. Here, we study Treg suppression mechanisms through unbiased phosphoproteomics of primary human Tcons upon TCR stimulation and Treg-mediated suppression, respectively. Tregs induced a state of overall decreased phosphorylation as opposed to TCR stimulation. We discovered novel phosphosites (T595_S597) in the DEF6 (SLAT) protein that were phosphorylated upon TCR stimulation and conversely dephosphorylated upon coculture with Tregs. Mutation of these DEF6 phosphosites abrogated interaction of DEF6 with the IP3 receptor and affected NFAT activation and cytokine transcription in primary Tcons. This novel mechanism and phosphoproteomics data resource may aid in modifying sensitivity of Tcons to Treg-mediated suppression in autoimmune disease or cancer. PMID:28993769

A regulatory governance perspective on health technology assessment (HTA) in France: the contextual mediation of common functional pressures.

PubMed

Barron, Anthony J G; Klinger, Corinna; Shah, Sara Mehmood Birchall; Wright, John S F

2015-02-01

The new regulatory governance perspective has introduced several insights to the study of health technology assessment (HTA): it has broadened the scope for the analysis of HTA; it has provided a more sophisticated account of national diversity and the potential for cross-border policy learning; and, it has dissolved the distinction between HTA assessment and appraisal processes. In this paper, we undertake a qualitative study of the French process for HTA with a view to introducing a fourth insight: that the emergence and continuing function of national agencies for HTA follows a broadly evolutionary pattern in which contextual factors play an important mediating role. We demonstrate that the French process for HTA is characterised by distinctive institutions, processes and evidential requirements. Consistent with the mediating role of this divergent policy context, we argue that even initiatives for the harmonisation of national approaches to HTA are likely to meet with divergent national policy responses. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The Role of Nuclear Receptor Coactivator A1B1 in Growth Factor-Mediated Mammary Tumorigenesis

DTIC Science & Technology

2007-03-01

study display dwarfism and the retardation of mammary gland growth [9]. At the 4-month time point, I similarly observed an overall decrease in mammary...Coactivator A1B1 in Growth Factor- Mediated Mammary Tumorigenesis PRINCIPAL INVESTIGATOR: Mark P Fereshteh (BS) CONTRACTING ORGANIZATION...U.S. Army Medical Research and Materiel Command Fort Detrick, Maryland 21702-5012 DISTRIBUTION

Epidermal Growth Factor Enhances Cellular Uptake of Polystyrene Nanoparticles by Clathrin-Mediated Endocytosis

PubMed Central

Phuc, Le Thi Minh; Taniguchi, Akiyoshi

2017-01-01

The interaction between nanoparticles and cells has been studied extensively, but most research has focused on the effect of various nanoparticle characteristics, such as size, morphology, and surface charge, on the cellular uptake of nanoparticles. In contrast, there have been very few studies to assess the influence of cellular factors, such as growth factor responses, on the cellular uptake efficiency of nanoparticles. The aim of this study was to clarify the effects of epidermal growth factor (EGF) on the uptake efficiency of polystyrene nanoparticles (PS NPs) by A431 cells, a human carcinoma epithelial cell line. The results showed that EGF enhanced the uptake efficiency of A431 cells for PS NPs. In addition, inhibition and localization studies of PS NPs and EGF receptors (EGFRs) indicated that cellular uptake of PS NPs is related to the binding of EGF–EGFR complex and PS NPs. Different pathways are used to enter the cells depending on the presence or absence of EGF. In the presence of EGF, cellular uptake of PS NPs is via clathrin-mediated endocytosis, whereas, in the absence of EGF, uptake of PS NPs does not involve clathrin-mediated endocytosis. Our findings indicate that EGF enhances cellular uptake of PS NPs by clathrin-mediated endocytosis. This result could be important for developing safe nanoparticles and their safe use in medical applications. PMID:28629179

Epidermal Growth Factor Enhances Cellular Uptake of Polystyrene Nanoparticles by Clathrin-Mediated Endocytosis.

PubMed

Phuc, Le Thi Minh; Taniguchi, Akiyoshi

2017-06-19

The interaction between nanoparticles and cells has been studied extensively, but most research has focused on the effect of various nanoparticle characteristics, such as size, morphology, and surface charge, on the cellular uptake of nanoparticles. In contrast, there have been very few studies to assess the influence of cellular factors, such as growth factor responses, on the cellular uptake efficiency of nanoparticles. The aim of this study was to clarify the effects of epidermal growth factor (EGF) on the uptake efficiency of polystyrene nanoparticles (PS NPs) by A431 cells, a human carcinoma epithelial cell line. The results showed that EGF enhanced the uptake efficiency of A431 cells for PS NPs. In addition, inhibition and localization studies of PS NPs and EGF receptors (EGFRs) indicated that cellular uptake of PS NPs is related to the binding of EGF-EGFR complex and PS NPs. Different pathways are used to enter the cells depending on the presence or absence of EGF. In the presence of EGF, cellular uptake of PS NPs is via clathrin-mediated endocytosis, whereas, in the absence of EGF, uptake of PS NPs does not involve clathrin-mediated endocytosis. Our findings indicate that EGF enhances cellular uptake of PS NPs by clathrin-mediated endocytosis. This result could be important for developing safe nanoparticles and their safe use in medical applications.

E3Net: a system for exploring E3-mediated regulatory networks of cellular functions.

PubMed

Han, Youngwoong; Lee, Hodong; Park, Jong C; Yi, Gwan-Su

2012-04-01

Ubiquitin-protein ligase (E3) is a key enzyme targeting specific substrates in diverse cellular processes for ubiquitination and degradation. The existing findings of substrate specificity of E3 are, however, scattered over a number of resources, making it difficult to study them together with an integrative view. Here we present E3Net, a web-based system that provides a comprehensive collection of available E3-substrate specificities and a systematic framework for the analysis of E3-mediated regulatory networks of diverse cellular functions. Currently, E3Net contains 2201 E3s and 4896 substrates in 427 organisms and 1671 E3-substrate specific relations between 493 E3s and 1277 substrates in 42 organisms, extracted mainly from MEDLINE abstracts and UniProt comments with an automatic text mining method and additional manual inspection and partly from high throughput experiment data and public ubiquitination databases. The significant functions and pathways of the extracted E3-specific substrate groups were identified from a functional enrichment analysis with 12 functional category resources for molecular functions, protein families, protein complexes, pathways, cellular processes, cellular localization, and diseases. E3Net includes interactive analysis and navigation tools that make it possible to build an integrative view of E3-substrate networks and their correlated functions with graphical illustrations and summarized descriptions. As a result, E3Net provides a comprehensive resource of E3s, substrates, and their functional implications summarized from the regulatory network structures of E3-specific substrate groups and their correlated functions. This resource will facilitate further in-depth investigation of ubiquitination-dependent regulatory mechanisms. E3Net is freely available online at http://pnet.kaist.ac.kr/e3net.

Escherichia coli growth changes by the mediated effects after low-intensity electromagnetic irradiation of extremely high frequencies.

PubMed

Torgomyan, Heghine; Hovnanyan, Karlen; Trchounian, Armen

2013-04-01

Water is the major constituent of environmental medium and biological systems. The effects occurring in water as a result of low-intensity electromagnetic irradiation (EMI) in extremely high frequencies are supposed to be the primary mechanism to create conditions for biological responses. The EMI effects on Escherichia coli, after irradiation of their suspension, are most probably water-mediated. Indirect effects of EMI at 51.8, 53, 70.6, and 73 GHz frequencies on bacteria, through water, assay buffer (Tris-phosphate buffer with inorganic salts at low or moderate concentrations), or peptone growth medium were studied. The mediated effects of 70.6 and 73 GHz irradiated water, assay buffer, and growth medium on E. coli growth characteristics were insignificant. But the results were different for 51.8 and 53 GHz. EMI mediated effects on bacterial growth were clearly demonstrated. The effects were more strongly expressed with 53 GHz. Moreover, it was shown that 70.6 and 73 GHz similarly suppressed the cell growth after direct irradiation of E. coli in water or on solid medium. Interestingly, for 51.8 and 53 GHz the bacterial growth decreases after suspension irradiation was less, compared to the direct irradiation of bacteria on solid medium. Especially, it was also more expressed in case of 53 GHz. Also with electron microscopy, EMI-induced bacterial cell sizes and structure different changes were detected. In addition, the distinguished changes in surface tension, oxidation-reduction potential and pH of water, assay buffer, growth medium, and bacterial suspension were determined. They depended on EMI frequency used. The differences could be associated with the partial absorbance of EMI energy by the surrounding medium, which depends on a specific frequency. The results are crucial to understand biophysical mechanisms of EMI effects on bacteria.

Spiritual Growth or Decline and Meaning-Making as Mediators of Anxiety and Satisfaction with Life During Religious Struggle.

PubMed

Zarzycka, Beata; Zietek, Pawel

2018-03-14

A number of studies have demonstrated links between spiritual struggles and health problems. As yet, however, only a few studies have investigated what makes religious struggle a source of mental problems or a source of well-being. We determined whether spiritual growth, spiritual decline, and meaning-making mediated the relationship between religious struggle and anxiety and satisfaction with life. Of the 180 respondents, 92 were women, and mean (SD) age was 24 (8.2) years. Each respondent completed the Religious and Spiritual Struggles Scale, the Meaning-Making Scale, the Spiritual Transformation Scale, the State-Trait Anxiety Inventory, and the Satisfaction with Life Scale. Religious struggle correlated positively with anxiety and negatively with satisfaction with life. Spiritual growth mediated the relationship between moral and demonic struggle with satisfaction with life, and spiritual decline mediated the relationship between demonic, moral, and interpersonal struggle with anxiety. Finally, meaning-making mediated the relationship between religious doubt and satisfaction with life.

Selective role for RGS12 as a Ras/Raf/MEK scaffold in nerve growth factor-mediated differentiation

PubMed Central

Willard, Melinda D; Willard, Francis S; Li, Xiaoyan; Cappell, Steven D; Snider, William D; Siderovski, David P

2007-01-01

Regulator of G-protein signaling (RGS) proteins accelerate GTP hydrolysis by heterotrimeric G-protein α subunits and thus inhibit signaling by many G protein-coupled receptors. Several RGS proteins have a multidomain architecture that adds further complexity to their roles in cell signaling in addition to their GTPase-accelerating activity. RGS12 contains a tandem repeat of Ras-binding domains but, to date, the role of this protein in Ras-mediated signal transduction has not been reported. Here, we show that RGS12 associates with the nerve growth factor (NGF) receptor tyrosine kinase TrkA, activated H-Ras, B-Raf, and MEK2 and facilitates their coordinated signaling to prolonged ERK activation. RGS12 is required for NGF-mediated neurite outgrowth of PC12 cells, but not outgrowth stimulated by basic fibroblast growth factor. siRNA-mediated knockdown of RGS12 expression also inhibits NGF-induced axonal growth in dissociated cultures of primary dorsal root ganglia neurons. These data suggest that RGS12 may play a critical, and receptor-selective, role in coordinating Ras-dependent signals that are required for promoting and/or maintaining neuronal differentiation. PMID:17380122

Mediators involved in the immunomodulatory effects of apoptotic cells.

PubMed

Saas, Philippe; Bonnefoy, Francis; Kury-Paulin, Stephanie; Kleinclauss, François; Perruche, Sylvain

2007-07-15

Immunomodulatory properties are attributed to apoptotic cells. These properties have been used to modulate allogeneic immune responses in experimental transplantation settings. In independent studies, apoptotic cell infusion has been shown to favor hematopoietic cell engraftment, to increase heart graft survival, and to delay the lethal onset of graft-versus-host disease (GVHD). The goal of this review was to discuss how apoptotic cell infusion interferes with graft rejection or host rejection (i.e., GVHD) and to focus on the potential mediators or "perpetuators" involved in apoptotic cell-induced immunomodulation. Particular emphasis on apoptotic cell phagocytosis, transforming growth factor (TGF)-beta secretion, and regulatory T cell induction was performed. Stimulating "naturally" immunosuppressive molecules (i.e., TGF-beta) or immunomodulatory cells ("alternatively-activated" macrophages, certain dendritic cell subsets, or regulatory T cells) in a physiological manner by using apoptotic cell infusion can be a promising way to induce tolerance.

Inhibitory Effects of Polyacetylene Compounds from Panax ginseng on Neurotrophin Receptor-Mediated Hair Growth.

PubMed

Suzuki, Aoi; Matsuura, Daisuke; Kanatani, Hirotoshi; Yano, Shingo; Tsunakawa, Mitsuo; Matsuyama, Shigeru; Shigemori, Hideyuki

2017-01-01

Neurotrophins play an important role in the control of the hair growth cycle. Therefore, neurotrophin receptor antagonists have therapeutic potential for the treatment of hair growth disorders. In this study, we investigated the inhibitory effect of Panax ginseng, a medicinal plant commonly used to treat alopecia, on the binding of neurotrophins to their receptors. In addition, we isolated and characterized the bioactive compounds of P. ginseng extracts. P. ginseng hexane extracts strongly inhibited brain-derived neurotrophic factor (BDNF)-TrkB and β-nerve growth factor (β-NGF)-p75 neurotrophin receptor (p75NTR) binding. Furthermore, we identified the following 6 polyacetylene compounds as the bioactive components in P. ginseng hexane extract: panaxynol (1), panaxydol (2), panaxydol chlorohydrin (3), 1,8-heptadecadiene-4,6-diyne-3,10-diol (4), panaxytriol (5), and dihydropanaxacol (6). In particular, compounds 4, 5, and 6 significantly inhibited BDNF-TrkB binding in a dose-dependent manner. To identify the structural component mediating the inhibitory effect, we investigated the effects of the hydroxyl moiety in these compounds. We found that the inhibitory effect of panaxytriol (5) was strong, whereas the inhibitory effect of Ac-panaxytriol (7) was relatively weak. Our findings suggest that P. ginseng-derived polyacetylenes with a hydroxyl moiety might provide therapeutic benefits to patients with hair growth disorders such as alopecia by inhibiting the binding of neurotrophins to their receptors. Although saponins have been proposed to be the primary mediators of the effects of P. ginseng on hair growth, this study revealed that polyacetylene compounds exert similar effects.

ROLES OF EPIDERMAL GROWTH FACTOR (EGF) AND TRANSFORMING GROWTH FACTOR-ALPHA (TGF-A) IN MEDIATION OF DIOXIN (TCDD)-INDUCED DELAYS IN DEVELOPMENT OF THE MOUSE MAMMARY GLAND

EPA Science Inventory

Roles of Epidermal Growth Factor (EGF) and Transforming Growth Factor-alpha (TGF-a) in Mediation of Dioxin (TCDD)-Induced Delays in Development of the Mouse Mammary Gland.
Suzanne E. Fenton, Barbara Abbott, Lamont Bryant, and Angela Buckalew. U.S. EPA, NHEERL, Reproductive Tox...

Mediator structure and rearrangements required for holoenzyme formation.

PubMed

Tsai, Kuang-Lei; Yu, Xiaodi; Gopalan, Sneha; Chao, Ti-Chun; Zhang, Ying; Florens, Laurence; Washburn, Michael P; Murakami, Kenji; Conaway, Ronald C; Conaway, Joan W; Asturias, Francisco J

2017-04-13

The conserved Mediator co-activator complex has an essential role in the regulation of RNA polymerase II transcription in all eukaryotes. Understanding the structure and interactions of Mediator is crucial for determining how the complex influences transcription initiation and conveys regulatory information to the basal transcription machinery. Here we present a 4.4 Å resolution cryo-electron microscopy map of Schizosaccharomyces pombe Mediator in which conserved Mediator subunits are individually resolved. The essential Med14 subunit works as a central backbone that connects the Mediator head, middle and tail modules. Comparison with a 7.8 Å resolution cryo-electron microscopy map of a Mediator-RNA polymerase II holoenzyme reveals that changes in the structure of Med14 facilitate a large-scale Mediator rearrangement that is essential for holoenzyme formation. Our study suggests that access to different conformations and crosstalk between structural elements are essential for the Mediator regulation mechanism, and could explain the capacity of the complex to integrate multiple regulatory signals.

Molecular mechanisms of intrauterine growth restriction.

PubMed

Gurugubelli Krishna, Rao; Vishnu Bhat, B

2017-07-10

Intrauterine growth restriction (IUGR) is a pregnancy specific disease characterized by decreased growth rate of fetus than the normal growth potential at particular gestational age. In the current scenario it is a leading cause of fetal and neonatal morbidity and mortality. In the last decade exhilarating experimental studies from several laboratories have provided fascinating proof for comprehension of molecular basis of IUGR. Atypical expression of enzymes governed by TGFβ causes the placental apoptosis and altered expression of TGFβ due to hyper alimentation causes impairment of lung function. Crosstalk of cAMP with protein kinases plays a prominent role in the regulation of cortisol levels. Increasing levels of NOD1 proteins leads to development of IUGR by increasing the levels of inflammatory mediators. Increase in leptin synthesis in placental trophoblast cells is associated with IUGR. In this review, we emphasize on the regulatory mechanisms of IUGR and its associated diseases. They may help improve the in-utero fetal growth and provide a better therapeutic intervention for prevention and treatment of IUGR.

Polarized Growth in the Absence of F-Actin in Saccharomyces cerevisiae Exiting Quiescence

PubMed Central

Sahin, Annelise; Daignan-Fornier, Bertrand; Sagot, Isabelle

2008-01-01

Background Polarity establishment and maintenance are crucial for morphogenesis and development. In budding yeast, these two intricate processes involve the superposition of regulatory loops between polarity landmarks, RHO GTPases, actin-mediated vesicles transport and endocytosis. Deciphering the chronology and the significance of each molecular step of polarized growth is therefore very challenging. Principal Findings We have taken advantage of the fact that yeast quiescent cells display actin bodies, a non polarized actin structure, to evaluate the role of F-actin in bud emergence. Here we show that upon exit from quiescence, actin cables are not required for the first steps of polarized growth. We further show that polarized growth can occur in the absence of actin patch-mediated endocytosis. We finally establish, using latrunculin-A, that the first steps of polarized growth do not require any F-actin containing structures. Yet, these structures are required for the formation of a bona fide daughter cell and cell cycle completion. We propose that upon exit from quiescence in the absence of F-actin, secretory vesicles randomly reach the plasma membrane but preferentially dock and fuse where polarity cues are localized, this being sufficient to trigger polarized growth. PMID:18596916

Trauma or growth after a natural disaster? The mediating role of rumination processes

PubMed Central

García, Felipe E.; Cova, Félix; Rincón, Paulina; Vázquez, Carmelo

2015-01-01

The aim of this study was to test a cognitive model of posttraumatic symptoms (PTS) and posttraumatic growth (PTG) after exposure to a natural disaster. It was hypothesized that although subjective severity of trauma would be related to the severity of PTS, this relation would be mediated by brooding and cognitive strategies related to the presence of repetitive negative content in thoughts. Furthermore, the relation between severity and PTG would be fully mediated by deliberate rumination (DR), cognitive strategies related to conscious efforts focused on handling the event. To evaluate the cognitive model, adults (N=351) who lost their homes as a result of the earthquake and tsunami that occurred in Chile on February 27, 2010, were selected. Structural equation modeling was used to analyze the data. The resulting model had adequate indices of goodness adjustment and showed that brooding completely mediated the relation between subjective severity and PTS, and DR completely mediated the relation between subjective severity, brooding, and PTG. These results highlight the role of both the content and process of rumination in mediating the association between subjective severity of trauma, PTS, and PTG. The implications of these results for a more comprehensive model of symptom severity that occurs after trauma are discussed. PMID:26234365

A Novel Gibberellin-Induced Gene from Rice and Its Potential Regulatory Role in Stem Growth1

PubMed Central

van der Knaap, Esther; Kim, Jeong Hoe; Kende, Hans

2000-01-01

Os-GRF1 (Oryza sativa-GROWTH-REGULATING FACTOR1) was identified in a search for genes that are differentially expressed in the intercalary meristem of deepwater rice (Oryza sativa L.) internodes in response to gibberellin (GA). Os-GRF1 displays general features of transcription factors, contains a functional nuclear localization signal, and has three regions with similarities to sequences in the database. One of these regions is similar to a protein interaction domain of SWI2/SNF2, which is a subunit of a chromatin-remodeling complex in yeast. The two other domains are novel and found only in plant proteins of unknown function. To study its role in plant growth, Os-GRF1 was expressed in Arabidopsis. Stem elongation of transformed plants was severely inhibited, and normal growth could not be recovered by the application of GA. Our results indicate that Os-GRF1 belongs to a novel class of plant proteins and may play a regulatory role in GA-induced stem elongation. PMID:10712532

The regulation of reproductive neuroendocrine function by insulin and insulin-like growth factor-1 (IGF-1)

PubMed Central

Wolfe, Andrew; Divall, Sara; Wu, Sheng

2014-01-01

The mammalian reproductive hormone axis regulates gonadal steroid hormone levels and gonadal function essential for reproduction. The neuroendocrine control of the axis integrates signals from a wide array of inputs. The regulatory pathways important for mediating these inputs have been the subject of numerous studies. One class of proteins that have been shown to mediate metabolic and growth signals to the CNS includes Insulin and IGF-1. These proteins are structurally related and can exert endocrine and growth factor like action via related receptor tyrosine kinases. The role that insulin and IGF-1 play in controlling the hypothalamus and pituitary and their role in regulating puberty and nutritional control of reproduction has been studied extensively. This review summarizes the in vitro and in vivo models that have been used to study these neuroendocrine structures and the influence of these growth factors on neuroendocrine control of reproduction. PMID:24929098

The Hippo-YAP signaling pathway and contact inhibition of growth

PubMed Central

Gumbiner, Barry M.; Kim, Nam-Gyun

2014-01-01

ABSTRACT The Hippo-YAP pathway mediates the control of cell proliferation by contact inhibition as well as other attributes of the physical state of cells in tissues. Several mechanisms sense the spatial and physical organization of cells, and function through distinct upstream modules to stimulate Hippo-YAP signaling: adherens junction or cadherin–catenin complexes, epithelial polarity and tight junction complexes, the FAT-Dachsous morphogen pathway, as well as cell shape, actomyosin or mechanotransduction. Soluble extracellular factors also regulate Hippo pathway signaling, often inhibiting its activity. Indeed, the Hippo pathway mediates a reciprocal relationship between contact inhibition and mitogenic signaling. As a result, cells at the edges of a colony, a wound in a tissue or a tumor are more sensitive to ambient levels of growth factors and more likely to proliferate, migrate or differentiate through a YAP and/or TAZ-dependent process. Thus, the Hippo-YAP pathway senses and responds to the physical organization of cells in tissues and coordinates these physical cues with classic growth-factor-mediated signaling pathways. This Commentary is focused on the biological significance of Hippo-YAP signaling and how upstream regulatory modules of the pathway interact to produce biological outcomes. PMID:24532814

Deliberate Rumination and Positive Reappraisal as Serial Mediators Between Life Impact and Posttraumatic Growth in Victims of State Terrorism in Chile (1973-1990).

PubMed

Cárdenas Castro, Manuel; Arnoso Martínez, Maitane; Faúndez Abarca, Ximena

2016-04-06

This study examines the role of coping strategies related to positive reappraisal versus other cognitive strategies (deliberate rumination) as mediators between life impact and posttraumatic growth in survivors of the military dictatorship in Chile between 1973 and 1990 (tortured political prisoners and family members of political prisoners executed and missing). Survey data from 251 political violence survivors were analyzed using the SPSS PROCESS macro for bootstrapping indirect effects (Hayes, 2013). Results indicated that positive reappraisal (or reframing) coping mediated the relationship between life impact and posttraumatic growth. A serial multiple mediation model indicates that in the life impact to growth moderation process, rumination must be followed by positive reappraisal to drive this growth. These findings suggest that positive reappraisal of the traumatic experience is essential to achieve growth reports. Implications of these more complex relations are discussed for both counseling interventions and further research. © The Author(s) 2016.

Antitumor action of 3-bromopyruvate implicates reorganized tumor growth regulatory components of tumor milieu, cell cycle arrest and induction of mitochondria-dependent tumor cell death.

PubMed

Yadav, Saveg; Kujur, Praveen Kumar; Pandey, Shrish Kumar; Goel, Yugal; Maurya, Babu Nandan; Verma, Ashish; Kumar, Ajay; Singh, Rana Pratap; Singh, Sukh Mahendra

2018-01-15

Evidences demonstrate that metabolic inhibitor 3-bromopyruvate (3-BP) exerts a potent antitumor action against a wide range of malignancies. However, the effect of 3-BP on progression of the tumors of thymic origin remains unexplored. Although, constituents of tumor microenvironment (TME) plays a pivotal role in regulation of tumor progression, it remains unclear if 3-BP can alter the composition of the crucial tumor growth regulatory components of the external surrounding of tumor cells. Thus, the present investigation attempts to understand the effect of 3-BP administration to a host bearing a progressively growing tumor of thymic origin on tumor growth regulatory soluble, cellular and biophysical components of tumor milieu vis-à-vis understanding its association with tumor progression, accompanying cell cycle events and mode of cell death. Further, the expression of cell survival regulatory molecules and hemodynamic characteristics of the tumor milieu were analysed to decipher mechanisms underlying the antitumor action of 3-BP. Administration of 3-BP to tumor-bearing hosts retarded tumor progression accompanied by induction of tumor cell death, cell cycle arrest, declined metabolism, inhibited mitochondrial membrane potential, elevated release of cytochrome c and altered hemodynamics. Moreover, 3-BP reconstituted the external milieu, in concurrence with deregulated glucose and pH homeostasis and increased tumor infiltration by NK cells, macrophages, and T lymphocytes. Further, 3-BP administration altered the expression of key regulatory molecules involved in glucose uptake, intracellular pH and tumor cell survival. The outcomes of this study will help in optimizing the therapeutic application of 3-BP by targeting crucial tumor growth regulatory components of tumor milieu. Copyright © 2017 Elsevier Inc. All rights reserved.

Genes uniquely expressed in human growth plate chondrocytes uncover a distinct regulatory network.

PubMed

Li, Bing; Balasubramanian, Karthika; Krakow, Deborah; Cohn, Daniel H

2017-12-20

Chondrogenesis is the earliest stage of skeletal development and is a highly dynamic process, integrating the activities and functions of transcription factors, cell signaling molecules and extracellular matrix proteins. The molecular mechanisms underlying chondrogenesis have been extensively studied and multiple key regulators of this process have been identified. However, a genome-wide overview of the gene regulatory network in chondrogenesis has not been achieved. In this study, employing RNA sequencing, we identified 332 protein coding genes and 34 long non-coding RNA (lncRNA) genes that are highly selectively expressed in human fetal growth plate chondrocytes. Among the protein coding genes, 32 genes were associated with 62 distinct human skeletal disorders and 153 genes were associated with skeletal defects in knockout mice, confirming their essential roles in skeletal formation. These gene products formed a comprehensive physical interaction network and participated in multiple cellular processes regulating skeletal development. The data also revealed 34 transcription factors and 11,334 distal enhancers that were uniquely active in chondrocytes, functioning as transcriptional regulators for the cartilage-selective genes. Our findings revealed a complex gene regulatory network controlling skeletal development whereby transcription factors, enhancers and lncRNAs participate in chondrogenesis by transcriptional regulation of key genes. Additionally, the cartilage-selective genes represent candidate genes for unsolved human skeletal disorders.

Hormonal and Nutritional Features in Contrasting Rootstock-mediated Tomato Growth under Low-phosphorus Nutrition.

PubMed

Martínez-Andújar, Cristina; Ruiz-Lozano, Juan M; Dodd, Ian C; Albacete, Alfonso; Pérez-Alfocea, Francisco

2017-01-01

Grafting provides a tool aimed to increase low-P stress tolerance of crops, however, little is known about the mechanism (s) by which rootstocks can confer resistance to P deprivation. In this study, 4 contrasting groups of rootstocks from different genetic backgrounds ( Solanum lycopersicum var. cerasiforme and introgression and recombinant inbred lines derived from the wild relatives S. pennellii and S. pimpinellifolium ) were grafted to a commercial F1 hybrid scion and cultivated under control (1 mM, c ) and P deficient (0.1 mM, p ) conditions for 30 days, to analyze rootstocks-mediated traits that impart low ( L , low shoot dry weight, SDW) or high ( H , high SDW) vigor. Xylem sap ionic and hormonal anlyses leaf nutritional status suggested that some physiological traits can explain rootstocks impacts on shoot growth. Although xylem P concentration increased with root biomass under both growing conditions, shoot biomass under low-P was explained by neither changes in root growth nor P transport and assimilation. Indeed, decreased root P export only explained the sensitivity of the HcLp rootstocks, while leaf P status was similarly affected in all graft combinations. Interestingly, most of the nutrients analyzed in the xylem sap correlated with root biomass under standard fertilization but only Ca was consistently related to shoot biomass under both control and low-P, suggesting an important role for this nutrient in rootstock-mediated vigor. Moreover, foliar Ca, S, and Mn concentrations were (i) specifically correlated with shoot growth under low-P and (ii) positively and negatively associated to the root-to-shoot transport of the cytokinin trans -zeatin ( t -Z) and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC), respectively. Indeed, those hormones seem to play an antagonistic positive ( t -Z) and negative (ACC) role in the rootstock-mediated regulation of shoot growth in response to P nutrition. The use of Hp -type rootstocks seems to

Sociocognitive self-regulatory mechanisms governing transgressive behavior.

PubMed

Bandura, A; Caprara, G V; Barbaranelli, C; Pastorelli, C; Regalia, C

2001-01-01

This longitudinal research examined a structural model of the self-regulatory mechanisms governing transgressive conduct. Perceived academic and self-regulatory efficacy concurrently and longitudinally deterred transgressiveness both directly and by fostering prosocialness and adherence to moral self-sanctions for harmful conduct. The impact of perceived social self-efficacy was mediated through prosocialness. Moral disengagement and prosocialness affected transgressiveness through the mediating influence of irascible affectivity and hostile rumination. Ruminative affectivity, in turn, both concurrently and longitudinally affected transgressiveness. Moral disengagement also contributed independently to variance in transgressiveness over time. This pattern of relations was obtained after controlling for prior transgressiveness. The structural model was replicated across gender and provided a better fit to the data than did several alternative models.

Posttraumatic growth in patients who survived cardiac surgery: the predictive and mediating roles of faith-based factors.

PubMed

Ai, Amy L; Hall, Daniel; Pargament, Kenneth; Tice, Terrence N

2013-04-01

Despite the growing knowledge of posttraumatic growth, only a few studies have examined personal growth in the context of cardiac health. Similarly, longitudinal research is lacking on the implications of religion/spirituality for patients with advanced cardiac diseases. This paper aims to explore the effect of preoperative religious coping on long-term postoperative personal growth and potential mediation in this effect. Analyses capitalized on a preoperative survey and medical indices from the Society of Thoracic Surgeons' National Database of patients undergoing cardiac surgery. Participants in the current follow-up study completed a mailed survey 30 months after surgery. Hierarchical regression analysis was performed to evaluate the extent to which preoperative use of religious coping predicted growth at follow-up, after controlling for key demographics, medical indices, mental health, and protective factors. Predictors of posttraumatic growth at follow-up were positive religious coping and a living status without a partner. Medical indices, optimistic expectations, social support, and other religious factors were unrelated to posttraumatic growth. Including religious factors diminished effects of gender, age, and race. Including perceived spiritual support completely eliminated the role of positive religious coping, indicating mediation. Preoperative positive religious coping may have a long-term effect on postoperative personal growth, explainable by higher spiritual connections as a part of significance-making. These results suggest that spirituality may play a favorable role in cardiac patients' posttraumatic growth after surviving a life-altering operation. The elimination of demographic effects may help explain previously mixed findings concerning the association between these factors and personal growth.

Twin-mediated epitaxial growth of highly lattice-mismatched Cu/Ag core-shell nanowires.

PubMed

Weng, Wei-Lun; Hsu, Chin-Yu; Lee, Jheng-Syun; Fan, Hsin-Hsin; Liao, Chien-Neng

2018-05-31

Lattice-mismatch is an important factor for the heteroepitaxial growth of core-shell nanostructures. A large lattice-mismatch usually leads to a non-coherent interface or a polycrystalline shell layer. In this study, a conformal Ag layer is coated on Cu nanowires with dense nanoscale twin boundaries through a galvanic replacement reaction. Despite a large lattice mismatch between Ag and Cu (∼12.6%), the Ag shell replicates the twinning structure in Cu nanowires and grows epitaxially on the nanotwinned Cu nanowire. A twin-mediated growth mechanism is proposed to explain the epitaxy of high lattice-mismatch bimetallic systems in which the misfit dislocations are accommodated by coherent twin boundaries.

Volatile-Mediated Effects Predominate in Paraburkholderia phytofirmans Growth Promotion and Salt Stress Tolerance of Arabidopsis thaliana

PubMed Central

Ledger, Thomas; Rojas, Sandy; Timmermann, Tania; Pinedo, Ignacio; Poupin, María J.; Garrido, Tatiana; Richter, Pablo; Tamayo, Javier

2016-01-01

Abiotic stress has a growing impact on plant growth and agricultural activity worldwide. Specific plant growth promoting rhizobacteria have been reported to stimulate growth and tolerance to abiotic stress in plants, and molecular mechanisms like phytohormone synthesis and 1-aminocyclopropane-1-carboxylate deamination are usual candidates proposed to mediate these bacterial effects. Paraburkholderia phytofirmans PsJN is able to promote growth of several plant hosts, and improve their tolerance to chilling, drought and salinity. This work investigated bacterial determinants involved in PsJN stimulation of growth and salinity tolerance in Arabidopsis thaliana, showing bacteria enable plants to survive long-term salinity treatment, accumulating less sodium within leaf tissues relative to non-inoculated controls. Inactivation of specific bacterial genes encoding ACC deaminase, auxin catabolism, N-acyl-homoserine-lactone production, and flagellin synthesis showed these functions have little influence on bacterial induction of salinity tolerance. Volatile organic compound emission from strain PsJN was shown to reproduce the effects of direct bacterial inoculation of roots, increasing plant growth rate and tolerance to salinity evaluated both in vitro and in soil. Furthermore, early exposure to VOCs from P. phytofirmans was sufficient to stimulate long-term effects observed in Arabidopsis growth in the presence and absence of salinity. Organic compounds were analyzed in the headspace of PsJN cultures, showing production of 2-undecanone, 7-hexanol, 3-methylbutanol and dimethyl disulfide. Exposure of A. thaliana to different quantities of these molecules showed that they are able to influence growth in a wide range of added amounts. Exposure to a blend of the first three compounds was found to mimic the effects of PsJN on both general growth promotion and salinity tolerance. To our knowledge, this is the first report on volatile compound-mediated induction of plant abiotic

[Regulatory Mechanisms of PD-L1 Expression and Its Role in Immune Evasion].

PubMed

Kataoka, Keisuke

2017-11-01

Immune checkpoint blockade therapy using anti-PD-1 or anti-PD-L1 antibodies can unleash anti-tumor immunity and induce durable remission in a variety ofhuman cancers. However, the regulatory mechanisms of PD-L1 expression mediating immune evasion ofcancer cells have not been fully elucidated, including the genetic alterations causing PD-L1 overexpression. Recently, we have reported a novel genetic mechanism ofimmune evasion associated with structural variations(SVs)disrupting the 3'-untranslated region(UTR)ofthe PD-L1 gene in various malignancies, such as aggressive lymphomas and gastrointestinal cancers. Despite a heterogenous nature ofthese SVs, they are closely associated with a marked upregulation of PD-L1 expression, which augments tumor growth and escape from anti-tumor immunity. Here we present an overview of the regulatory mechanisms of PD-L1 expression in cancer cells, highlighting the genetic mechanisms of PD-L1 constitutive activation, with specific focus on PD-L1 3'-UTR disruption.

Treating atherosclerosis with regulatory T cells.

PubMed

Foks, Amanda C; Lichtman, Andrew H; Kuiper, Johan

2015-02-01

Regulatory T cells (Tregs) play an important role in the regulation of T-cell-mediated immune responses through suppression of T-cell proliferation and secretion of inhibitory cytokines, such as interleukin-10 and transforming growth factor-β. Impaired Treg numbers and function have been associated with numerous diseases, and an imbalance between proinflammatory/proatherogenic cells and Tregs promotes atherosclerotic disease. Restoration of this balance by inducing Tregs has great therapeutic potential to prevent cardiovascular disease. In addition to suppressing differentiation and function of effector T cells, Tregs have been shown to induce anti-inflammatory macrophages, inhibit foam cell formation and to influence cholesterol metabolism. Furthermore, Tregs suppress immune responses of endothelial cells and innate lymphoid cells. In this review, we focus on the recent knowledge on Treg subsets, their activity and function in atherosclerosis, and discuss promising strategies to use Tregs as a therapeutic tool to prevent cardiovascular disease. © 2014 American Heart Association, Inc.

Axl as a mediator of cellular growth and survival

PubMed Central

Axelrod, Haley; Pienta, Kenneth J.

2014-01-01

The control of cellular growth and proliferation is key to the maintenance of homeostasis. Survival, proliferation, and arrest are regulated, in part, by Growth Arrest Specific 6 (Gas6) through binding to members of the TAM receptor tyrosine kinase family. Activation of the TAM receptors leads to downstream signaling through common kinases, but the exact mechanism within each cellular context varies and remains to be completely elucidated. Deregulation of the TAM family, due to its central role in mediating cellular proliferation, has been implicated in multiple diseases. Axl was cloned as the first TAM receptor in a search for genes involved in the progression of chronic to acute-phase leukemia, and has since been established as playing a critical role in the progression of cancer. The oncogenic nature of Axl is demonstrated through its activation of signaling pathways involved in proliferation, migration, inhibition of apoptosis, and therapeutic resistance. Despite its recent discovery, significant progress has been made in the development of effective clinical therapeutics targeting Axl. In order to accurately define the role of Axl in normal and diseased processes, it must be analyzed in a cell type-specific context. PMID:25344858

Axl as a mediator of cellular growth and survival.

PubMed

Axelrod, Haley; Pienta, Kenneth J

2014-10-15

The control of cellular growth and proliferation is key to the maintenance of homeostasis. Survival, proliferation, and arrest are regulated, in part, by Growth Arrest Specific 6 (Gas6) through binding to members of the TAM receptor tyrosine kinase family. Activation of the TAM receptors leads to downstream signaling through common kinases, but the exact mechanism within each cellular context varies and remains to be completely elucidated. Deregulation of the TAM family, due to its central role in mediating cellular proliferation, has been implicated in multiple diseases. Axl was cloned as the first TAM receptor in a search for genes involved in the progression of chronic to acute-phase leukemia, and has since been established as playing a critical role in the progression of cancer. The oncogenic nature of Axl is demonstrated through its activation of signaling pathways involved in proliferation, migration, inhibition of apoptosis, and therapeutic resistance. Despite its recent discovery, significant progress has been made in the development of effective clinical therapeutics targeting Axl. In order to accurately define the role of Axl in normal and diseased processes, it must be analyzed in a cell type-specific context.

Social support influences on eating awareness in children and adolescents: the mediating effect of self-regulatory strategies.

PubMed

Gaspar de Matos, Margarida; Palmeira, Antonio L; Gaspar, Tania; De Wit, John B F; Luszczynska, Aleksandra

2016-01-01

The impact of the social environment on healthy eating awareness results from complex interactions among physical, economic, cultural, interpersonal and individual characteristics. This study investigated the impact of social support and social influence on healthy eating awareness, controlling for socio-economic status, gender and age. Additionally, the mediating effect of self-regulation strategies was examined. A total of 2764 children and adolescents aged 10-17 from four European countries completed self-report measures on healthy eating awareness, social influence and the use of self-regulation strategies. Healthy eating awareness and the use of self-regulation strategies were more likely to occur among younger participants. An interaction between gender and age was related to the use of some self-regulation strategies; compared to girls, boys decreased the use of self-regulation strategies more from pre-adolescence to adolescence. Peer social influence was associated with more unhealthy eating in older participants. Results suggest a need to promote self-regulatory competences among young people in order to assist them with regulating their eating behaviours, especially in the presence of peers. Both school-based interventions and family-based interventions, focusing on self-regulation cognitions and social (peer) influence, could help children and adolescents to use self-regulatory strategies which are essential to eat healthier.

Sphingosine kinase-1 mediates androgen-induced osteoblast cell growth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Claire; Universite de Toulouse, UPS, IPBS, Toulouse F-31000; Lafosse, Jean-Michel

Herein we report that the lipid kinase sphingosine kinase-1 (SphK1) is instrumental in mediating androgen-induced cell proliferation in osteoblasts. Dihydrotestosterone (DHT) triggered cell growth in steroid-deprived MC3T3 cells, which was associated with a rapid stimulation of SphK1 and activation of both Akt and ERK signaling pathways. This mechanism relied on functional androgen receptor/PI3K/Akt nongenotropic signaling as pharmacological antagonists could block SphK1 stimulation by DHT and its consequences. Finally, SphK1 inhibition not only abrogated DHT-induced ERK activation but also blocked cell proliferation, while ERK inhibition had no impact, suggesting that SphK1 was critical for DHT signaling yet independently of the ERK.

Sustaining self-regulatory efficacy and psychological outcome expectations for postnatal exercise: effects of a group-mediated cognitive behavioural intervention.

PubMed

Cramp, A G; Brawley, L R

2009-09-01

The objective of the current investigation was to examine if the effects of a group-mediated cognitive behavioural counselling plus exercise intervention were superior to the effects of a standard exercise care condition on postnatal mothers' self-regulatory efficacy (SRE), outcome expectations (OEs) and self-directed physical activity (PA). The design of the study consisted of two intervention conditions; group-mediated cognitive behavioural counselling plus exercise (GMCB) and standard exercise (SE). Each condition consisted of two phases; a 4-week supervised, centre-based intensive exercise training phase followed by a 4-week home-based phase. Participants were 57 postnatal women randomly assigned to conditions (SE: N=31; GMCB: N=26). Measures of SRE and OEs were assessed prior to and following the centre-based aspect of the intervention. Physical activity was measured following the intensive exercise training phase as well as the home-based phase. GMCB participants' SRE and OEs were sustained during the intervention whereas those of SE participants declined. GMCB participants also reported significantly greater time spent engaging in self-directed PA at the conclusion of the intensive and home-based phases. Mediation analysis revealed that SRE partially mediated the relationship between intervention condition and post home-based PA as confirmed by a significant sobel test. These findings suggest that a theory-based GMCB counselling plus exercise intervention is superior to the SE condition in sustaining SRE and OEs, and in promoting greater self-directed PA. SRE partially mediated the relationship between intervention condition and post home-based PA supporting the targeting of that variable for change as part of the intervention.

Growth phase-dependent control of R27 conjugation is mediated by the interplay between the plasmid-encoded regulatory circuit TrhR/TrhY-HtdA and the cAMP regulon.

PubMed

Gibert, Marta; Paytubi, Sonia; Beltrán, Sergi; Juárez, Antonio; Balsalobre, Carlos; Madrid, Cristina

2016-12-01

Plasmids of the incompatibility group HI1 (IncHI1) have been isolated from several Gram-negative pathogens and are associated with the spread of multidrug resistance. Their conjugation is tightly regulated and it is inhibited at temperatures higher than 30°C, indicating that conjugation occurs outside warm-blooded hosts. Using R27, the prototype of IncHI1 plasmids, we report that plasmid transfer efficiency in E. coli strongly depends on the physiological state of the donor cells. Conjugation frequency is high when cells are actively growing, dropping sharply when cells enter the stationary phase of growth. Accordingly, our transcriptomic assays show significant downregulation of numerous R27 genes during the stationary phase, including several tra (transfer) genes. Growth phase-dependent regulation of tra genes transcription is independent of H-NS, a silencer of horizontal gene transfer, and ppGpp and RpoS, regulators of the stationary phase, but highly dependent on the plasmid-encoded regulatory circuit TrhR/TrhY-HtdA. The metabolic sensor cAMP, whose synthesis is chromosomally encoded, is also involved in the growth phase regulation of R27 conjugation by modulating htdA expression. Our data suggest that the involvement of regulators encoded by both chromosome and plasmid are required for efficient physiological control of IncHI1 plasmid conjugation. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

The regulation of reproductive neuroendocrine function by insulin and insulin-like growth factor-1 (IGF-1).

PubMed

Wolfe, Andrew; Divall, Sara; Wu, Sheng

2014-10-01

The mammalian reproductive hormone axis regulates gonadal steroid hormone levels and gonadal function essential for reproduction. The neuroendocrine control of the axis integrates signals from a wide array of inputs. The regulatory pathways important for mediating these inputs have been the subject of numerous studies. One class of proteins that have been shown to mediate metabolic and growth signals to the CNS includes Insulin and IGF-1. These proteins are structurally related and can exert endocrine and growth factor like action via related receptor tyrosine kinases. The role that insulin and IGF-1 play in controlling the hypothalamus and pituitary and their role in regulating puberty and nutritional control of reproduction has been studied extensively. This review summarizes the in vitro and in vivo models that have been used to study these neuroendocrine structures and the influence of these growth factors on neuroendocrine control of reproduction. Copyright © 2014 Elsevier Inc. All rights reserved.

Methionine enkephalin (MENK) inhibits tumor growth through regulating CD4+Foxp3+ regulatory T cells (Tregs) in mice.

PubMed

Li, Xuan; Meng, Yiming; Plotnikoff, Nicolas P; Youkilis, Gene; Griffin, Noreen; Wang, Enhua; Lu, Changlong; Shan, Fengping

2015-01-01

Methionine enkephalin (MENK), an endogenous neuropeptide, plays an crucial role in both neuroendocrine and immune systems. CD4+Foxp3+ regulatory T cells (Tregs) are identified as a major subpopulation of T lymphocytes in suppressing immune system to keep balanced immunity. The aim of this research work was to elucidate the mechanisms via which MENK interacts with Tregs in cancer situation. The influence of MENK on transforming growth factor-β (TGF-β) mediated conversion from naïve CD4+CD25- T cells to CD4+CD25+ Tregs was determined and the data from flow cytometry (FCM) analysis indicated that MENK effectively inhibited the expression of Foxp3 during the process of TGF-βinduction. Furthermore, this inhibiting process was accompanied by diminishing phosphorylation and nuclear translocation of Smad2/3, confirmed by western blot (WB) analysis and immunofluorescence (IF) at molecular level. We established sarcoma mice model with S180 to investigate whether MENK could modulate Tregs in tumor circumstance. Our findings showed that MENK delayed the development of tumor in S180 tumor bearing mice and down-regulated level of Tregs. Together, these novel findings reached a conclusion that MENK could inhibit Tregs activity directly and retard tumor development through down-regulating Tregs in mice. This work advances the deepening understanding of the influence of MENK on Tregs in cancer situation, and relation of MENK with immune system, supporting the implication of MENK as a new strategy for cancer immunotherapy.

Counter-regulatory paracrine actions of FGF-23 and 1,25(OH)2D in macrophages

PubMed Central

Han, Xiaobin; Li, Linqiang; Yang, Jiancheng; King, Gwendalyn; Xiao, Zhousheng; Quarles, Leigh Darryl

2016-01-01

Mechanisms underlying the association between fibroblastic growth factor 23 (FGF-23) and inflammation are uncertain. We found that FGF-23 was markedly up-regulated in LPS/INF-γ-induced proinflammatory M1 macrophages and Hyp mouse-derived peritoneal macrophages, but not in IL-4-induced M2 anti-inflammatory macrophages. NF-κB and JAK/STAT1 pathways mediated the increased transcription of FGF-23 in response to M1 polarization. FGF-23 stimulated TNF-α, but not IL-6, expression in M0 macrophages and suppressed Arginase-1 expression in M2 macrophages through FGFR-mediated mechanisms. 1,25(OH)2D stimulated Arginase-1 expression and inhibited FGF-23 stimulation of TNF-α. FGF-23 has proinflammatory paracrine functions and counter-regulatory actions to 1,25(OH)2D on innate immune responses. PMID:26762170

Malleable machines in transcription regulation: the mediator complex.

PubMed

Tóth-Petróczy, Agnes; Oldfield, Christopher J; Simon, István; Takagi, Yuichiro; Dunker, A Keith; Uversky, Vladimir N; Fuxreiter, Monika

2008-12-01

The Mediator complex provides an interface between gene-specific regulatory proteins and the general transcription machinery including RNA polymerase II (RNAP II). The complex has a modular architecture (Head, Middle, and Tail) and cryoelectron microscopy analysis suggested that it undergoes dramatic conformational changes upon interactions with activators and RNAP II. These rearrangements have been proposed to play a role in the assembly of the preinitiation complex and also to contribute to the regulatory mechanism of Mediator. In analogy to many regulatory and transcriptional proteins, we reasoned that Mediator might also utilize intrinsically disordered regions (IDRs) to facilitate structural transitions and transmit transcriptional signals. Indeed, a high prevalence of IDRs was found in various subunits of Mediator from both Saccharomyces cerevisiae and Homo sapiens, especially in the Tail and the Middle modules. The level of disorder increases from yeast to man, although in both organisms it significantly exceeds that of multiprotein complexes of a similar size. IDRs can contribute to Mediator's function in three different ways: they can individually serve as target sites for multiple partners having distinctive structures; they can act as malleable linkers connecting globular domains that impart modular functionality on the complex; and they can also facilitate assembly and disassembly of complexes in response to regulatory signals. Short segments of IDRs, termed molecular recognition features (MoRFs) distinguished by a high protein-protein interaction propensity, were identified in 16 and 19 subunits of the yeast and human Mediator, respectively. In Saccharomyces cerevisiae, the functional roles of 11 MoRFs have been experimentally verified, and those in the Med8/Med18/Med20 and Med7/Med21 complexes were structurally confirmed. Although the Saccharomyces cerevisiae and Homo sapiens Mediator sequences are only weakly conserved, the arrangements of the

Platelet-Derived Growth Factor-BB Protects Mesenchymal Stem Cells (MSCs) Derived From Immune Thrombocytopenia Patients Against Apoptosis and Senescence and Maintains MSC-Mediated Immunosuppression

PubMed Central

Zhang, Jia-min; Feng, Fei-er; Wang, Qian-ming; Zhu, Xiao-lu; Fu, Hai-xia; Xu, Lan-ping; Liu, Kai-yan

2016-01-01

Immune thrombocytopenia (ITP) is characterized by platelet destruction and megakaryocyte dysfunction. Mesenchymal stem cells (MSCs) from ITP patients (MSC-ITP) do not exhibit conventional proliferative abilities and thus exhibit defects in immunoregulation, suggesting that MSC impairment might be a mechanism involved in ITP. Platelet-derived growth factor (PDGF) improves growth and survival in various cell types. Moreover, PDGF promotes MSC proliferation. The aim of the present study was to analyze the effects of PDGF-BB on MSC-ITP. We showed that MSC-ITP expanded more slowly and appeared flattened and larger. MSC-ITP exhibited increased apoptosis and senescence compared with controls. Both the intrinsic and extrinsic pathways account for the enhanced apoptosis. P53 and p21 expression were upregulated in MSC-ITP, but inhibition of p53 with pifithrin-α markedly inhibited apoptosis and senescence. Furthermore, MSCs from ITP patients showed a lower capacity for inhibiting the proliferation of activated T cells inducing regulatory T cells (Tregs) and suppressing the synthesis of anti-glycoprotein (GP)IIb-IIIa antibodies. PDGF-BB treatment significantly decreased the expression of p53 and p21 and increased survivin expression in MSC-ITP. In addition, the apoptotic rate and number of senescent cells in ITP MSCs were reduced. Their impaired ability for inhibiting activated T cells, inducing Tregs, and suppressing the synthesis of anti-GPIIb-IIIa antibodies was restored after PDGF-BB treatment. In conclusion, we have demonstrated that PDGF-BB protects MSCs derived from ITP patients against apoptosis, senescence, and immunomodulatory defects. This protective effect of PDGF-BB is likely mediated via the p53/p21 pathway, thus potentially providing a new therapeutic approach for ITP. Significance Immune thrombocytopenia (ITP) is characterized by platelet destruction and megakaryocyte dysfunction. Platelet-derived growth factor (PDGF) improves growth and survival in various

The Mediating Effect of Regulatory Emotional Self-Efficacy on the Association between Self-Esteem and School Bullying in Middle School Students: A Cross-Sectional Study.

PubMed

Wang, Xiaoqin; Zhang, Yue; Hui, Zhaozhao; Bai, Wanyue; Terry, Paul D; Ma, Mei; Li, Yang; Cheng, Li; Gu, Wei; Wang, Mingxu

2018-05-15

School bullying is negatively associated with self-esteem, but psychological mediators of bullying have yet to be clarified. We examined regulatory emotional self-efficacy (RESE) as a possible mediator in the association between self-esteem and school bullying. A cross-sectional study of 995 adolescents was conducted in two middle schools of Xi'an. All of the participants completed the Chinese version of the School Bullying Experience Questionnaire (C-SBEQ), Self-Esteem Scale (SES), and Regulatory Emotional Self-Efficacy Scale (RESE). Descriptive statistics analysis, the bias corrected percentile Bootstrap CI method, and structural equation modelling were used to analyze the data. The results showed that 418 students (42.0%) reported that they were involved in school bullying in the past year. Self-esteem was negatively associated with school bullying (total effect: β = -0.275, 95% CI = -0.381⁻-0.034), and RESE mediated the association between self-esteem and school bullying (indirect effect: β = -0.136, 95% CI = -0.245⁻-0.037). Furthermore, self-esteem had an indirect effect through perceived self-efficacy in managing negative affect, while self-esteem had no indirect effect through self-efficacy in the expression of positive affect. The present study suggests that school authorities and the related education departments should not only focus on improving students' self-esteem, but should also pay more attention to students' RESE, in order to mitigate, and potentially reduce, the occurrence of bullying.

RITA inhibits multiple myeloma cell growth through induction of p53-mediated caspase-dependent apoptosis and synergistically enhances nutlin-induced cytotoxic responses.

PubMed

Saha, Manujendra N; Jiang, Hua; Mukai, Asuka; Chang, Hong

2010-11-01

Mutations or deletions of p53 are relatively rare in multiple myeloma (MM), at least in newly diagnosed patients. Thus, restoration of p53 tumor suppressor function in MM by blocking the inhibitory role of murine double minute 2 (MDM2) is a promising and applicable therapeutic strategy. RITA and nutlin are two new classes of small molecule MDM2 inhibitors that prevent the p53-MDM2 interaction. Earlier reports showed p53-dependent activity of RITA in solid tumors as well as in leukemias. We and others recently described nutlin-induced apoptosis in MM cells, but it remains unclear whether RITA exerts antimyeloma activity. Here, we found that RITA activates the p53 pathway and induces apoptosis in MM cell lines and primary MM samples, preferentially killing myeloma cells. The activation of p53 induced by RITA was mediated through modulation of multiple apoptotic regulatory proteins, including upregulation of a proapoptotic protein (NOXA), downregulation of an antiapoptotic protein, Mcl-1, and activation of caspases through extrinsic pathways. Moreover, a number of key p53-mediated apoptotic target genes were identified by gene expression profiling and further validated by quantitative real-time PCR. Importantly, the combination of RITA with nutlin displayed a strong synergism on growth inhibition with the combination index ranging from 0.56 to 0.82 in MM cells. Our data support further clinical evaluation of RITA as a potential novel therapeutic intervention in MM. ©2010 AACR.

Epidermal growth factor regulation of glutathione S-transferase gene expression in the rat is mediated by class Pi glutathione S-transferase enhancer I.

PubMed

Matsumoto, M; Imagawa, M; Aoki, Y

2000-07-01

Using chloramphenicol acetyltransferase assays we showed that epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha), and 3,3',4,4',5-pentachlorobiphenyl (PenCB) induce class Pi glutathione S-transferase (GSTP1) in primary cultured rat liver parenchymal cells. GSTP1 enhancer I (GPEI), which is required for the stimulation of GSTP1 expression by PenCB, also mediates EGF and TGF alpha stimulation of GSTP1 gene expression. However, hepatocyte growth factor and insulin did not stimulate GPEI-mediated gene expression. On the other hand, the antioxidant reagents butylhydroxyanisole and t-butylhydroquinone, stimulated GPEI-mediated gene expression, but the level of GSTP1 mRNA was not elevated. Our observations suggest that EGF and TGF alpha induce GSTP1 by the same signal transduction pathway as PenCB. Since the sequence of GPEI is similar to that of the antioxidant responsive element (ARE), some factors which bind to ARE might play a role in GPEI-mediated gene expression.

Epidermal growth factor regulation of glutathione S-transferase gene expression in the rat is mediated by class Pi glutathione S-transferase enhancer I.

PubMed Central

Matsumoto, M; Imagawa, M; Aoki, Y

2000-01-01

Using chloramphenicol acetyltransferase assays we showed that epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha), and 3,3',4,4',5-pentachlorobiphenyl (PenCB) induce class Pi glutathione S-transferase (GSTP1) in primary cultured rat liver parenchymal cells. GSTP1 enhancer I (GPEI), which is required for the stimulation of GSTP1 expression by PenCB, also mediates EGF and TGF alpha stimulation of GSTP1 gene expression. However, hepatocyte growth factor and insulin did not stimulate GPEI-mediated gene expression. On the other hand, the antioxidant reagents butylhydroxyanisole and t-butylhydroquinone, stimulated GPEI-mediated gene expression, but the level of GSTP1 mRNA was not elevated. Our observations suggest that EGF and TGF alpha induce GSTP1 by the same signal transduction pathway as PenCB. Since the sequence of GPEI is similar to that of the antioxidant responsive element (ARE), some factors which bind to ARE might play a role in GPEI-mediated gene expression. PMID:10861232

Alu-mediated deletion of SOX10 regulatory elements in Waardenburg syndrome type 4

PubMed Central

Bondurand, Nadége; Fouquet, Virginie; Baral, Viviane; Lecerf, Laure; Loundon, Natalie; Goossens, Michel; Duriez, Benedicte; Labrune, Philippe; Pingault, Veronique

2012-01-01

Waardenburg syndrome type 4 (WS4) is a rare neural crest disorder defined by the combination of Waardenburg syndrome (sensorineural hearing loss and pigmentation defects) and Hirschsprung disease (intestinal aganglionosis). Three genes are known to be involved in this syndrome, that is, EDN3 (endothelin-3), EDNRB (endothelin receptor type B), and SOX10. However, 15–35% of WS4 remains unexplained at the molecular level, suggesting that other genes could be involved and/or that mutations within known genes may have escaped previous screenings. Here, we searched for deletions within recently identified SOX10 regulatory sequences and describe the first characterization of a WS4 patient presenting with a large deletion encompassing three of these enhancers. Analysis of the breakpoint region suggests a complex rearrangement involving three Alu sequences that could be mediated by a FosTes/MMBIR replication mechanism. Taken together with recent reports, our results demonstrate that the disruption of highly conserved non-coding elements located within or at a long distance from the coding sequences of key genes can result in several neurocristopathies. This opens up new routes to the molecular dissection of neural crest disorders. PMID:22378281

Alu-mediated deletion of SOX10 regulatory elements in Waardenburg syndrome type 4.

PubMed

Bondurand, Nadége; Fouquet, Virginie; Baral, Viviane; Lecerf, Laure; Loundon, Natalie; Goossens, Michel; Duriez, Benedicte; Labrune, Philippe; Pingault, Veronique

2012-09-01

Waardenburg syndrome type 4 (WS4) is a rare neural crest disorder defined by the combination of Waardenburg syndrome (sensorineural hearing loss and pigmentation defects) and Hirschsprung disease (intestinal aganglionosis). Three genes are known to be involved in this syndrome, that is, EDN3 (endothelin-3), EDNRB (endothelin receptor type B), and SOX10. However, 15-35% of WS4 remains unexplained at the molecular level, suggesting that other genes could be involved and/or that mutations within known genes may have escaped previous screenings. Here, we searched for deletions within recently identified SOX10 regulatory sequences and describe the first characterization of a WS4 patient presenting with a large deletion encompassing three of these enhancers. Analysis of the breakpoint region suggests a complex rearrangement involving three Alu sequences that could be mediated by a FosTes/MMBIR replication mechanism. Taken together with recent reports, our results demonstrate that the disruption of highly conserved non-coding elements located within or at a long distance from the coding sequences of key genes can result in several neurocristopathies. This opens up new routes to the molecular dissection of neural crest disorders.

Salicylic acid mediated growth, physiological and proteomic responses in two wheat varieties under drought stress.

PubMed

Sharma, Marisha; Gupta, Sunil K; Majumder, Baisakhi; Maurya, Vivek K; Deeba, Farah; Alam, Afroz; Pandey, Vivek

2017-06-23

Salicylic acid (SA) induced drought tolerance can be a key trait for increasing and stabilizing wheat production. These SA induced traits were studied in two Triticum aestivum L. varieties; drought tolerant, Kundan and drought sensitive, Lok1 under two different water deficit regimes: and rehydration at vegetative and flowering stages. SA alleviated the negative effects of water stress on photosynthesis more in Kundan. SA induced defense responses against drought by increasing antioxidative enzymes and osmolytes (proline and total soluble sugars). Differential proteomics revealed major role of carbon metabolism and signal transduction in enhancing drought tolerance in Kundan which was shifted towards defense, energy production and protection in Lok1. Thioredoxins played important role between SA and redox signaling in activating defense responses. SA showed substantial impact on physiology and carbon assimilation in tolerant variety for better growth under drought. Lok1 exhibited SA induced drought tolerance through enhanced defense system and energy metabolism. Plants after rehydration showed complete recovery of physiological functions under SA treatment. SA mediated constitutive defense against water stress did not compromise yield. These results suggest that exogenously applied SA under drought stress confer growth promoting and stress priming effects on wheat plants thus alleviating yield limitation. Studies have shown morphological, physiological and biochemical aspects associated with the SA mediated drought tolerance in wheat while understanding of molecular mechanism is limited. Herein, proteomics approach has identified significantly changed proteins and their potential relevance to SA mediated drought stress responses in drought tolerant and sensitive wheat varieties. SA regulates wide range of processes such as photosynthesis, carbon assimilation, protein metabolism, amino acid and energy metabolism, redox homeostasis and signal transduction under

Fibroblast growth factor represses Smad-mediated myofibroblast activation in aortic valvular interstitial cells

PubMed Central

Cushing, Melinda C.; Mariner, Peter D.; Liao, Jo-Tsu; Sims, Evan A.; Anseth, Kristi S.

2008-01-01

This study aimed to identify signaling pathways that oppose connective tissue fibrosis in the aortic valve. Using valvular interstitial cells (VICs) isolated from porcine aortic valve leaflets, we show that basic fibroblast growth factor (FGF-2) effectively blocks transforming growth factor-β1 (TGF-β1)-mediated myofibroblast activation. FGF-2 prevents the induction of α-smooth muscle actin (αSMA) expression and the exit of VICs from the cell cycle, both of which are hallmarks of myofibroblast activation. By blocking the activity of the Smad transcription factors that serve as the downstream nuclear effectors of TGF-β1, FGF-2 treatment inhibits fibrosis in VICs. Using an exogenous Smad-responsive transcriptional promoter reporter, we show that Smad activity is repressed by FGF-2, likely an effect of the fact that FGF-2 treatment prevents the nuclear localization of Smads in these cells. This appears to be a direct effect of FGF signaling through mitogen-activated protein kinase (MAPK) cascades as the treatment of VICs with the MAPK/extracellular regulated kinase (MEK) inhibitor U0126 acted to induce fibrosis and blocked the ability of FGF-2 to inhibit TGF-β1 signaling. Furthermore, FGF-2 treatment of VICs blocks the development of pathological contractile and calcifying phenotypes, suggesting that these pathways may be utilized in the engineering of effective treatments for valvular disease.—Cushing, M. C., Mariner, P. D., Liao, J. T., Sims, E. A., Anseth, K. S. Fibroblast growth factor represses Smad-mediated myofibroblast activation in aortic valvular interstitial cells. PMID:18218921

Study of surfactant mediated growth of Ni/V superlattices

NASA Astrophysics Data System (ADS)

Amir, S. M.; Gupta, Mukul; Potdar, Satish; Gupta, Ajay; Stahn, Jochen

2013-07-01

The Ni/V multilayers are useful as soft x-ray mirrors, polarizers, and phase retarders. For these applications, it is necessary that the interfaces roughness and interdiffusion must be as small as possible. The V-on-Ni and Ni-on-V interfaces are asymmetric due to the difference in the surface free energy of Ni and V. In this work, we report Ag surfactant mediated growth of Ni/V superlattices prepared using ion beam sputter deposition technique. These superlattices were studied using x-ray and neutron scattering techniques. It was found that when added in an optimum amount, Ag surfactant results in reduced interface roughness and interdiffusion across the interfaces. Obtained results can be understood with the surfactant floating-off mechanism leading to a balance in the surface free energy of Ni and V.

Connective tissue growth factor mediates TGF-β1-induced low-grade serous ovarian tumor cell apoptosis.

PubMed

Cheng, Jung-Chien; Chang, Hsun-Ming; Leung, Peter C K

2017-10-17

Ovarian low-grade serous carcinoma (LGSC) is a rare disease and is now considered to be a distinct entity from high-grade serous carcinoma (HGSC), which is the most common and malignant form of epithelial ovarian cancer. Connective tissue growth factor (CTGF) is a secreted matricellular protein that has been shown to modulate many biological functions by interacting with multiple molecules in the microenvironment. Increasing evidence indicates that aberrant expression of CTGF is associated with cancer development and progression. Transforming growth factor-β1 (TGF-β1) is a well-known molecule that can strongly up-regulate CTGF expression in different types of normal and cancer cells. Our previous study demonstrated that TGF-β1 induces apoptosis of LGSC cells. However, the effect of TGF-β1 on CTGF expression in LGSC needs to be defined. In addition, whether CTGF mediates TGF-β1-induced LGSC cell apoptosis remains unknown. In the present study, we show that TGF-β1 treatment up-regulates CTGF expression by activating SMAD3 signaling in two human LGSC cell lines. Additionally, siRNA-mediated CTGF knockdown attenuates TGF-β1-induced cell apoptosis. Moreover, our results show that the inhibitory effect of the CTGF knockdown on TGF-β1-induced cell apoptosis is mediated by down-regulating SMAD3 expression. This study demonstrates an important role for CTGF in mediating the pro-apoptotic effects of TGF-β1 on LGCS.

A Guide to Approaching Regulatory Considerations for Lentiviral-Mediated Gene Therapies.

PubMed

White, Michael; Whittaker, Roger; Gándara, Carolina; Stoll, Elizabeth A

2017-08-01

Lentiviral vectors are increasingly the gene transfer tool of choice for gene or cell therapies, with multiple clinical investigations showing promise for this viral vector in terms of both safety and efficacy. The third-generation vector system is well characterized, effectively delivers genetic material and maintains long-term stable expression in target cells, delivers larger amounts of genetic material than other methods, is nonpathogenic, and does not cause an inflammatory response in the recipient. This report aims to help academic scientists and regulatory managers negotiate the governance framework to achieve successful translation of a lentiviral vector-based gene therapy. The focus is on European regulations and how they are administered in the United Kingdom, although many of the principles will be similar for other regions, including the United States. The report justifies the rationale for using third-generation lentiviral vectors to achieve gene delivery for in vivo and ex vivo applications; briefly summarizes the extant regulatory guidance for gene therapies, categorized as advanced therapeutic medicinal products (ATMPs); provides guidance on specific regulatory issues regarding gene therapies; presents an overview of the key stakeholders to be approached when pursuing clinical trials authorization for an ATMP; and includes a brief catalogue of the documentation required to submit an application for regulatory approval of a new gene therapy.

Developmental risk and young children's regulatory strategies: predicting behavior problems at age five.

PubMed

Gerstein, Emily D; Pedersen Y Arbona, Anita; Crnic, Keith A; Ryu, Ehri; Baker, Bruce L; Blacher, Jan

2011-04-01

Children with early developmental delays are at heightened risk for behavior problems and comorbid psychopathology. This study examined the trajectories of regulatory capabilities and their potentially mediating role in the development of behavior problems for children with and without early developmental delays. A sample of 231 children comprised of 137 typically developing children and 94 children with developmental delays were examined during mildly frustrating laboratory tasks across the preschool period (ages 3-5). Results indicated that children with delays had greater use of maladaptive strategies (distraction, distress venting) and lower use of adaptive strategies (constructive coping) than typically developing children. For both groups, strategies had similar rates of growth across time; maladaptive strategies decreased and adaptive strategies increased. The intercept of strategy use, but not the slope, was found to mediate the relation between developmental risk and externalizing behaviors. Findings support that dysregulation, rather than the developmental risk, may be responsible for the high levels of comorbid psychopathology.

Androgen Receptor-Mediated Growth Suppression of HPr-1AR and PC3-Lenti-AR Prostate Epithelial Cells

PubMed Central

Bolton, Eric C.

2015-01-01

The androgen receptor (AR) mediates the developmental, physiologic, and pathologic effects of androgens including 5α-dihydrotestosterone (DHT). However, the mechanisms whereby AR regulates growth suppression and differentiation of luminal epithelial cells in the prostate gland and proliferation of malignant versions of these cells are not well understood, though they are central to prostate development, homeostasis, and neoplasia. Here, we identify androgen-responsive genes that restrain cell cycle progression and proliferation of human prostate epithelial cell lines (HPr-1AR and PC3-Lenti-AR), and we investigate the mechanisms through which AR regulates their expression. DHT inhibited proliferation of HPr-1AR and PC3-Lenti-AR, and cell cycle analysis revealed a prolonged G1 interval. In the cell cycle, the G1/S-phase transition is initiated by the activity of cyclin D and cyclin-dependent kinase (CDK) complexes, which relieve growth suppression. In HPr-1AR, cyclin D1/2 and CDK4/6 mRNAs were androgen-repressed, whereas CDK inhibitor, CDKN1A, mRNA was androgen-induced. The regulation of these transcripts was AR-dependent, and involved multiple mechanisms. Similar AR-mediated down-regulation of CDK4/6 mRNAs and up-regulation of CDKN1A mRNA occurred in PC3-Lenti-AR. Further, CDK4/6 overexpression suppressed DHT-inhibited cell cycle progression and proliferation of HPr-1AR and PC3-Lenti-AR, whereas CDKN1A overexpression induced cell cycle arrest. We therefore propose that AR-mediated growth suppression of HPr-1AR involves cyclin D1 mRNA decay, transcriptional repression of cyclin D2 and CDK4/6, and transcriptional activation of CDKN1A, which serve to decrease CDK4/6 activity. AR-mediated inhibition of PC3-Lenti-AR proliferation occurs through a similar mechanism, albeit without down-regulation of cyclin D. Our findings provide insight into AR-mediated regulation of prostate epithelial cell proliferation. PMID:26372468

The multitalented Mediator complex.

PubMed

Carlsten, Jonas O P; Zhu, Xuefeng; Gustafsson, Claes M

2013-11-01

The Mediator complex is needed for regulated transcription of RNA polymerase II (Pol II)-dependent genes. Initially, Mediator was only seen as a protein bridge that conveyed regulatory information from enhancers to the promoter. Later studies have added many other functions to the Mediator repertoire. Indeed, recent findings show that Mediator influences nearly all stages of transcription and coordinates these events with concomitant changes in chromatin organization. We review the multitude of activities associated with Mediator and discuss how this complex coordinates transcription with other cellular events. We also discuss the inherent difficulties associated with in vivo characterization of a coactivator complex that can indirectly affect diverse cellular processes via changes in gene transcription. Copyright © 2013 Elsevier Ltd. All rights reserved.

RNA-Binding Proteins in Trichomonas vaginalis: Atypical Multifunctional Proteins Involved in a Posttranscriptional Iron Regulatory Mechanism

PubMed Central

Figueroa-Angulo, Elisa E.; Calla-Choque, Jaeson S.; Mancilla-Olea, Maria Inocente; Arroyo, Rossana

2015-01-01

Iron homeostasis is highly regulated in vertebrates through a regulatory system mediated by RNA-protein interactions between the iron regulatory proteins (IRPs) that interact with an iron responsive element (IRE) located in certain mRNAs, dubbed the IRE-IRP regulatory system. Trichomonas vaginalis, the causal agent of trichomoniasis, presents high iron dependency to regulate its growth, metabolism, and virulence properties. Although T. vaginalis lacks IRPs or proteins with aconitase activity, possesses gene expression mechanisms of iron regulation at the transcriptional and posttranscriptional levels. However, only one gene with iron regulation at the transcriptional level has been described. Recently, our research group described an iron posttranscriptional regulatory mechanism in the T. vaginalis tvcp4 and tvcp12 cysteine proteinase mRNAs. The tvcp4 and tvcp12 mRNAs have a stem-loop structure in the 5'-coding region or in the 3'-UTR, respectively that interacts with T. vaginalis multifunctional proteins HSP70, α-Actinin, and Actin under iron starvation condition, causing translation inhibition or mRNA stabilization similar to the previously characterized IRE-IRP system in eukaryotes. Herein, we summarize recent progress and shed some light on atypical RNA-binding proteins that may participate in the iron posttranscriptional regulation in T. vaginalis. PMID:26703754

Genetic analysis of conidiation regulatory pathways in koji-mold Aspergillus oryzae.

PubMed

Ogawa, Masahiro; Tokuoka, Masafumi; Jin, Feng Jie; Takahashi, Tadashi; Koyama, Yasuji

2010-01-01

Conidia of koji-mold Aspergillus oryzae are often used as starters in the fermented food industry. However, little is known about conidiation regulation in A. oryzae. To improve the productivity of conidia in A. oryzae, it is necessary to understand conidiation regulation in the strain. Therefore, we analyzed the conidiation regulatory system in A. oryzae using 10 kinds of conidiation regulatory gene disruptants. The phenotypes of AorfluG, AorflbA, AorflbB, AorflbC, AorflbD, AorflbE, AorbrlA, AorabaA, AorwetA, and AorfadA mutants are almost identical to those of the corresponding mutants in Aspergillus nidulans. The results indicated that the functions of conidiation regulatory genes are almost conserved between A. oryzae and A. nidulans. However, the severely reduced conidiation phenotype of the AorfluG disruptant in A. oryzae differs from the phenotype of the corresponding mutant in Aspergillus fumigatus in air-exposed culture conditions. These results suggest that A. oryzae, A. nidulans, and A. fumigatus have a G-protein signaling pathway and brlA orthologs in common, and only A. fumigatus has particular brlA activation pathways that are independent of the fluG ortholog. Furthermore, the analyses of AorflbA disruptant and AorfadA dominant-active mutants implicated that AorFadA-mediated G-protein signaling suppresses vegetative growth of A. oryzae.

Engineered Interleukin-2 Antagonists for the Inhibition of Regulatory T cells

PubMed Central

Liu, David V.; Maier, Lisa M.; Hafler, David A.; Wittrup, K. Dane

2014-01-01

The immunosuppressive effects of CD4+ CD25high regulatory T cells interfere with anti-tumor immune responses in cancer patients. Here, we present a novel class of engineered human Interleukin (IL)-2 analogues that antagonize the IL-2 receptor, for inhibiting regulatory T cell suppression. These antagonists have been engineered for high affinity to the α subunit of the IL-2 receptor and very low affinity to either the β or γ subunit, resulting in a signaling-deficient IL-2 analogue that sequesters the IL-2 receptor α subunit from wild type IL-2. Two variants, “V91R” and “Q126T” with residue substitutions that disrupt the β and γ subunit binding interfaces, respectively, have been characterized in both a T cell line and in human primary regulatory T cells. These mutants retain their high affinity binding to IL-2 receptor α subunit, but do not activate STAT5 phosphorylation or stimulate T cell growth. The two mutants competitively antagonize wild-type IL-2 signaling through the IL-2 receptor with similar efficacy, with inhibition constants of 183 pM for V91R and 216 pM for Q126T. Here, we present a novel approach to CD25-mediated Treg inhibition, with the use of an engineered human IL-2 analogue that antagonizes the IL-2 receptor. PMID:19816193

A Guide to Approaching Regulatory Considerations for Lentiviral-Mediated Gene Therapies

PubMed Central

White, Michael; Whittaker, Roger; Gándara, Carolina; Stoll, Elizabeth A.

2017-01-01

Lentiviral vectors are increasingly the gene transfer tool of choice for gene or cell therapies, with multiple clinical investigations showing promise for this viral vector in terms of both safety and efficacy. The third-generation vector system is well characterized, effectively delivers genetic material and maintains long-term stable expression in target cells, delivers larger amounts of genetic material than other methods, is nonpathogenic, and does not cause an inflammatory response in the recipient. This report aims to help academic scientists and regulatory managers negotiate the governance framework to achieve successful translation of a lentiviral vector-based gene therapy. The focus is on European regulations and how they are administered in the United Kingdom, although many of the principles will be similar for other regions, including the United States. The report justifies the rationale for using third-generation lentiviral vectors to achieve gene delivery for in vivo and ex vivo applications; briefly summarizes the extant regulatory guidance for gene therapies, categorized as advanced therapeutic medicinal products (ATMPs); provides guidance on specific regulatory issues regarding gene therapies; presents an overview of the key stakeholders to be approached when pursuing clinical trials authorization for an ATMP; and includes a brief catalogue of the documentation required to submit an application for regulatory approval of a new gene therapy. PMID:28817344

Direct and indirect effects of Growth Hormone Deficiency (GHD) on lung function in children: A mediation analysis.

PubMed

Cilluffo, Giovanna; Ferrante, Giuliana; Fasola, Salvatore; Ciresi, Alessandro; Cardillo, Irene; Tancredi, Giancarlo; Viegi, Giovanni; Giordano, Carla; Scichilone, Nicola; La Grutta, Stefania

2018-04-01

Studies on pulmonary function tests (PFTs) in Growth Hormone Deficiency (GHD) children are lacking. The aims of this study were: (i) to investigate PFTs in GHD pre-pubertal children with respect to Controls, before starting Growth Hormone Therapy (GHT) (T0); (ii) to evaluate changes of PFTs in GHD vs Controls, after 1-year GHT (T1). For both aims the mediation analysis (MA) was applied to evaluate the extent to which the relationship between GHD and PFTs could be ascribed to a height-mediated (indirect) or a GH direct effect. 47 pre-pubertal GHD children (aged 5-14 years) underwent PFTs at T0 and T1. At T0, 47 healthy children matched for age and sex were enrolled as Controls. A MA was performed to assess the relationship between GHD and PFTs and height. Statistical analyses were performed using the statistical software R (https://cran.r-project.org/mirrors.html). A p-value <0.05 was considered significant. At T0, PFTs indices were significantly lower in GHD than in Controls. From T0 to T1 a significant improvement was found in PFTs. The percentages of the mediated effect on FVC, FEV 1 , FEF 25-75% and TLC were <50% at T0, suggesting that the direct effect was prevalent. At T1, the percentages of the mediated effect for spirometry indices were ≥50%, indicating that the indirect (height-mediated) effect was the most relevant. The study shows that pre-pubertal children with GHD have an impairment of lung function not exclusively attributable to the indirect (height-mediated) effect, but also to the direct GH action which is mitigated after 1-year of GHT. Copyright © 2018 Elsevier Ltd. All rights reserved.

Growth Arrest of Epithelial Cells during Measles Virus Infection Is Caused by Upregulation of Interferon Regulatory Factor 1

PubMed Central

Yokota, Shin-ichi; Okabayashi, Tamaki; Yokosawa, Noriko; Fujii, Nobuhiro

2004-01-01

Natural infection with measles virus (MeV) is initiated when the virus reaches epithelial cells in the respiratory tract, oropharynx, or conjunctivae. Human epithelial cells infected with MeV frequently show growth suppression. In this study, we investigated the possible mechanisms for this suppression. The bronchiolar epithelial cell A549 showed growth arrest in G0/G1 following MeV infection or treatment with gamma interferon (IFN-γ). IFN regulatory factor-1 (IRF-1) was upregulated during MeV infection, although A549 did not produce IFN-γ. Cells of the cervical squamous cell line SiHa persistently infected with various strains of MeV displayed slower growth than uninfected SiHa cells, although the growth rates varied depending on the MeV strain. Transfection of antisense-oriented IRF-1 cDNA released the MeV-infected SiHa cells from growth suppression. Although these infected cells did not produce IFN-γ and suppressed IFN-α/β-induced Jak1 phosphorylation, Jak1 was constitutively phosphorylated. The growth rates negatively correlated with levels of both IRF-1 expression and constitutively phosphorylated Jak1. These results indicate that MeV upregulates IRF-1 in a manner that is independent of IFN but dependent on the JAK/STAT pathway. This induction of IRF-1 appears to suppress cell growth, although the extent seems to vary among MeV strains. PMID:15078941

Adenoviral mediated interferon-alpha 2b gene therapy suppresses the pro-angiogenic effect of vascular endothelial growth factor in superficial bladder cancer.

PubMed

Adam, Liana; Black, Peter C; Kassouf, Wassim; Eve, Beryl; McConkey, David; Munsell, Mark F; Benedict, William F; Dinney, Colin P N

2007-05-01

Intravesical adenovirus mediated interferon-alpha gene transfer has a potent therapeutic effect against superficial human bladder carcinoma xenografts growing in the bladder of athymic nude mice. We determined whether the inhibition of angiogenesis might contribute to the antitumor effect. We treated several human urothelial carcinoma cells with adenovirus mediated interferon-alpha 2b and monitored its effects on the production of angiogenic factors using real-time reverse-transcription polymerase chain reaction, Western blotting, and immunohistochemical analysis and a gel shift based transcription factor array. To assess the role of adenovirus mediated interferon 2b in angiogenic activity we used in vitro invasion assays and evaluated the anti-angiogenic effects of adenovirus mediated interferon gene therapy in an orthotopic murine model of human superficial bladder cancer. In adenovirus mediated interferon-alpha infected 253J B-V cells vascular endothelial growth factor was decreased and anti-angiogenic interferon-gamma inducible protein 10 was up-regulated. In contrast, the addition of as much as 100,000 IU recombinant interferon had no apparent effect on vascular endothelial growth factor production. Conditioned medium derived from adenovirus mediated interferon 2b infected 253J B-V cells greatly decreased the invasive potential of human endothelial cells and down-regulated their matrix metalloproteinase 2 expression compared to controls. Furthermore, adenovirus mediated interferon 2b blocked pro-angiogenic nuclear signals, such as the transcription factors activating protein-1 and 2, stimulating protein-1, nuclear factor kappaB and c-myb. In vivo experiments revealed significant vascular endothelial growth factor down-regulation and decreased tumor vessel density in the adenovirus mediated interferon 2b treated group compared to controls. Treatment with adenovirus mediated interferon 2b increases the angiostatic activity of the bladder cancer microenvironment

Phytochrome-mediated agravitropism in Arabidopsis hypocotyls requires GIL1 and confers a fitness advantage.

PubMed

Allen, Trudie; Ingles, Patricia J; Praekelt, Uta; Smith, Harry; Whitelam, Garry C

2006-05-01

Plants use specialized photoreceptors to detect the amount, quality, periodicity and direction of light and to modulate their growth and development accordingly. These regulatory light signals often interact with other environmental cues. Exposure of etiolated Arabidopsis seedlings to red (R) or far-red (FR) light causes hypocotyls to grow in random orientations with respect to the gravitational vector, thus overcoming the signal from gravity to grow upwards. This light response, mediated by either phytochrome A or phytochrome B, represents a prime example of cross-talk between environmental signalling systems. Here, we report the isolation the mutant gil1 (for gravitropic in the light) in which hypocotyls continue to grow upwards after exposure of seedlings to R or FR light. The gil1 mutant displays no other phenotypic alterations in response to gravity or light. Cloning of GIL1 has identified a novel gene that is necessary for light-dependent randomization of hypocotyl growth orientation. Using gil1, we have demonstrated that phytochrome-mediated randomization of Arabidopsis hypocotyl orientation provides a fitness advantage to seedlings developing in patchy, low-light environments.

p27 Nuclear localization and growth arrest caused by perlecan knockdown in human endothelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakai, Katsuya; Oka, Kiyomasa; Matsumoto, Kunio

2010-02-12

Perlecan, a secreted heparan sulfate proteoglycan, is a major component of the vascular basement membrane and participates in angiogenesis. Here, we used small interference RNA-mediated knockdown of perlecan expression to investigate the regulatory function of perlecan in the growth of human vascular endothelial cells. Basic fibroblast growth factor (bFGF)-induced ERK phosphorylation and cyclin D1 expression were unchanged by perlecan deficiency in endothelial cells; however, perlecan deficiency inhibited the Rb protein phosphorylation and DNA synthesis induced by bFGF. By contrast to cytoplasmic localization of the cyclin-dependent kinase inhibitor p27 in control endothelial cells, p27 was localized in the nucleus and itsmore » expression increased in perlecan-deficient cells, which suggests that p27 mediates inhibition of Rb phosphorylation. In addition to the well-characterized function of perlecan as a co-receptor for heparin-binding growth factors such as bFGF, our results suggest that perlecan plays an indispensible role in endothelial cell proliferation and acts through a mechanism that involves subcellular localization of p27.« less

Mediator Complex Subunits MED2, MED5, MED16, and MED23 Genetically Interact in the Regulation of Phenylpropanoid Biosynthesis.

PubMed

Dolan, Whitney L; Dilkes, Brian P; Stout, Jake M; Bonawitz, Nicholas D; Chapple, Clint

2017-12-01

The phenylpropanoid pathway is a major global carbon sink and is important for plant fitness and the engineering of bioenergy feedstocks. In Arabidopsis thaliana , disruption of two subunits of the transcriptional regulatory Mediator complex, MED5a and MED5b, results in an increase in phenylpropanoid accumulation. By contrast, the semidominant MED5b mutation reduced epidermal fluorescence4-3 ( ref4-3 ) results in dwarfism and constitutively repressed phenylpropanoid accumulation. Here, we report the results of a forward genetic screen for suppressors of ref4-3. We identified 13 independent lines that restore growth and/or phenylpropanoid accumulation in the ref4-3 background. Two of the suppressors restore growth without restoring soluble phenylpropanoid accumulation, indicating that the growth and metabolic phenotypes of the ref4-3 mutant can be genetically disentangled. Whole-genome sequencing revealed that all but one of the suppressors carry mutations in MED5b or other Mediator subunits. RNA-seq analysis showed that the ref4-3 mutation causes widespread changes in gene expression, including the upregulation of negative regulators of the phenylpropanoid pathway, and that the suppressors reverse many of these changes. Together, our data highlight the interdependence of individual Mediator subunits and provide greater insight into the transcriptional regulation of phenylpropanoid biosynthesis by the Mediator complex. © 2017 American Society of Plant Biologists. All rights reserved.

Control of leptin by metabolic state and its regulatory interactions with pituitary growth hormone and hepatic growth hormone receptors and insulin like growth factors in the tilapia (Oreochromis mossambicus).

PubMed

Douros, Jonathan D; Baltzegar, David A; Mankiewicz, Jamie; Taylor, Jordan; Yamaguchi, Yoko; Lerner, Darren T; Seale, Andre P; Grau, E Gordon; Breves, Jason P; Borski, Russell J

2017-01-01

Leptin is an important cytokine for regulating energy homeostasis, however, relatively little is known about its function and control in teleost fishes or other ectotherms, particularly with regard to interactions with the growth hormone (GH)/insulin-like growth factors (IGFs) growth regulatory axis. Here we assessed the regulation of LepA, the dominant paralog in tilapia (Oreochromis mossambicus) and other teleosts under altered nutritional state, and evaluated how LepA might alter pituitary growth hormone (GH) and hepatic insulin-like growth factors (IGFs) that are known to be disparately regulated by metabolic state. Circulating LepA, and lepa and lepr gene expression increased after 3-weeks fasting and declined to control levels 10days following refeeding. This pattern of leptin regulation by metabolic state is similar to that previously observed for pituitary GH and opposite that of hepatic GHR and/or IGF dynamics in tilapia and other fishes. We therefore evaluated if LepA might differentially regulate pituitary GH, and hepatic GH receptors (GHRs) and IGFs. Recombinant tilapia LepA (rtLepA) increased hepatic gene expression of igf-1, igf-2, ghr-1, and ghr-2 from isolated hepatocytes following 24h incubation. Intraperitoneal rtLepA injection, on the other hand, stimulated hepatic igf-1, but had little effect on hepatic igf-2, ghr1, or ghr2 mRNA abundance. LepA suppressed GH accumulation and gh mRNA in pituitaries in vitro, but had no effect on GH release. We next sought to test if abolition of pituitary GH via hypophysectomy (Hx) affects the expression of hepatic lepa and lepr. Hypophysectomy significantly increases hepatic lepa mRNA abundance, while GH replacement in Hx fish restores lepa mRNA levels to that of sham controls. Leptin receptor (lepr) mRNA was unchanged by Hx. In in vitro hepatocyte incubations, GH inhibits lepa and lepr mRNA expression at low concentrations, while higher concentration stimulates lepa expression. Taken together, these findings

Activated carbon decreases invasive plant growth by mediating plant–microbe interactions

PubMed Central

Nolan, Nicole E.; Kulmatiski, Andrew; Beard, Karen H.; Norton, Jeanette M.

2015-01-01

There is growing appreciation for the idea that plant–soil interactions (e.g. allelopathy and plant–microbe feedbacks) may explain the success of some non-native plants. Where this is the case, native plant restoration may require management tools that change plant–soil interactions. Activated carbon (AC) is one such potential tool. Previous research has shown the potential for high concentrations of AC to restore native plant growth to areas dominated by non-natives on a small scale (1 m × 1 m plots). Here we (i) test the efficacy of different AC concentrations at a larger scale (15 m × 15 m plots), (ii) measure microbial responses to AC treatment and (iii) use a greenhouse experiment to identify the primary mechanism, allelopathy versus microbial changes, through which AC impacts native and non-native plant growth. Three years after large-scale applications, AC treatments decreased non-native plant cover and increased the ratio of native to non-native species cover, particularly at concentrations >400 g m−2. Activated carbon similarly decreased non-native plant growth in the greenhouse. This effect, however, was only observed in live soils, suggesting that AC effects were microbially mediated and not caused by direct allelopathy. Bacterial community analysis of field soils indicated that AC increased the relative abundance of an unidentified bacterium and an Actinomycetales and decreased the relative abundance of a Flavobacterium, suggesting that these organisms may play a role in AC effects on plant growth. Results support the idea that manipulations of plant–microbe interactions may provide novel and effective ways of directing plant growth and community development (e.g. native plant restoration). PMID:25387751

Conflict Resolution in Chinese Adolescents' Friendship: Links with Regulatory Focus and Friendship Satisfaction.

PubMed

Gao, Qin; Bian, Ran; Liu, Ru-de; He, Yili; Oei, Tian-Po

2017-04-03

It is generally acknowledged that people adopt different resolution strategies when facing conflicts with others. However, the mechanisms of conflict resolution are still unclear and under researched, in particular within the context of Chinese adolescents' same-sex friendship relations. Thus, the present study investigated the mediator role of conflict resolution strategies in the relationship between regulatory foci and friendship satisfaction for the first time. 653 Chinese adolescents completed the regulatory foci, conflict resolution style, and friendship satisfaction measures. The results of the structure equation modeling showed that while promotion focus was positively associated with problem-solving and compliance, prevention focus was positively associated with withdrawal and conflict engagement. In addition, problem-solving mediated the relationship between promotion focus and friendship satisfaction, and conflict engagement mediated the relationship between prevention focus and friendship satisfaction. These findings contribute to understanding Chinese adolescents' use of conflict resolution strategies as well as the relationship between regulatory foci and behavioral strategies in negative situations.

Does social status within a dominance hierarchy mediate individual growth, residency and relocation?

PubMed

Akbaripasand, Abbas; Ramezani, J; Krkosek, Martin; Lokman, P Mark; Closs, Gerard P

2014-11-01

The availability of food, and hence energy, is known to influence the abundance, habitat choice and growth of individuals. In contrast, there is a paucity of knowledge on how the interaction of energy supply and social status determines patterns of residency and movement. This study tests whether the presence of conspecifics and an individual's social status in relation to food supply influence the fitness and movement of a drift-feeding fish (Galaxias fasciatus). Using an information-theoretic approach (AIC), our analysis indicated that the most parsimonious model of fish movement among pools was one that included food supply, social rank and fish relative growth rate. Our results indicated that subordinate fish relocated more frequently compared to dominant fish, most likely as a consequence of intra-specific competition that limited the access of these smaller fish to resources and constrained their growth. Our results suggest that energy constraints may force individuals to explore new habitats in an effort to find more energetically profitable patches. We conclude that intra-specific competition mediated through the social hierarchy amongst closely interacting individuals plays a key role in determining individual growth, residency and relocation.

From core belief challenge to posttraumatic growth in para sport athletes: moderated mediation by needs satisfaction and deliberate rumination.

PubMed

Hammer, Chris; Podlog, Leslie; Wadey, Ross; Galli, Nick; Forber-Pratt, Anjali J; Newton, Maria

2018-04-25

To examine how deliberate rumination and psychological need satisfaction interact to facilitate posttraumatic growth for para sport athletes with acquired disability. Utilizing a sample of 70 para sport athletes, the hypothesized mediating role of deliberate rumination was examined via a simple mediation model. The interaction between needs satisfaction and deliberate rumination and their effect on posttraumatic growth was examined utilizing a moderated mediation procedure. Disruption to one's core beliefs was significantly associated with posttraumatic growth. This relationship, was in part, explained by the deliberate rumination engaged in soon after the trauma. Needs satisfaction, while a significant predictor of posttraumatic growth, did not moderate the indirect effect. Although deliberate rumination at both timeframes and needs satisfaction were independently associated with posttraumatic growth, they did not interact in the hypothesized manner to influence posttraumatic growth. There remains a need to better understand how the experience of posttraumatic growth is achieved amongst individuals with acquired disability, and the role that para sport may play in this process. Implications for rehabilitation The disruption to one's core beliefs caused by acquiring a physical disability is not only a natural experience but also a necessary antecedent to posttraumatic growth. As such, rehabilitation practitioners ought to normalize these types of challenges when working with individuals with acquired disability. Practitioners may help to facilitate growth outcomes by encouraging individuals to deliberately ruminate about their acquired disability. That is, practitioners can help those with acquired disability to seek meaning and understanding about their disability or the precipitating event. For those who struggle to deliberately ruminate in the immediate disability aftermath, practitioners may encourage para sport participation to potentially prompt constructive

Sphingosine-1-phosphate mediates epidermal growth factor-induced muscle satellite cell activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagata, Yosuke, E-mail: cynagata@mail.ecc.u-tokyo.ac.jp; Ohashi, Kazuya; Wada, Eiji

2014-08-01

Skeletal muscle can regenerate repeatedly due to the presence of resident stem cells, called satellite cells. Because satellite cells are usually quiescent, they must be activated before participating in muscle regeneration in response to stimuli such as injury, overloading, and stretch. Although satellite cell activation is a crucial step in muscle regeneration, little is known of the molecular mechanisms controlling this process. Recent work showed that the bioactive lipid sphingosine-1-phosphate (S1P) plays crucial roles in the activation, proliferation, and differentiation of muscle satellite cells. We investigated the role of growth factors in S1P-mediated satellite cell activation. We found that epidermalmore » growth factor (EGF) in combination with insulin induced proliferation of quiescent undifferentiated mouse myoblast C2C12 cells, which are also known as reserve cells, in serum-free conditions. Sphingosine kinase activity increased when reserve cells were stimulated with EGF. Treatment of reserve cells with the D-erythro-N,N-dimethylsphingosine, Sphingosine Kinase Inhibitor, or siRNA duplexes specific for sphingosine kinase 1, suppressed EGF-induced C2C12 activation. We also present the evidence showing the S1P receptor S1P2 is involved in EGF-induced reserve cell activation. Moreover, we demonstrated a combination of insulin and EGF promoted activation of satellite cells on single myofibers in a manner dependent on SPHK and S1P2. Taken together, our observations show that EGF-induced satellite cell activation is mediated by S1P and its receptor. - Highlights: • EGF in combination with insulin induces proliferation of quiescent C2C12 cells. • Sphingosine kinase activity increases when reserve cells are stimulated with EGF. • EGF-induced activation of reserve cells is dependent on sphingosine kinase and ERK. • The S1P receptor S1P2 is involved in EGF-induced reserve cell activation. • EGF-induced reserve cell activation is mediated by S1P and

CD22 expression mediates the regulatory functions of peritoneal B-1a cells during the remission phase of contact hypersensitivity reactions.

PubMed

Nakashima, Hiroko; Hamaguchi, Yasuhito; Watanabe, Rei; Ishiura, Nobuko; Kuwano, Yoshihiro; Okochi, Hitoshi; Takahashi, Yoshimasa; Tamaki, Kunihiko; Sato, Shinichi; Tedder, Thomas F; Fujimoto, Manabu

2010-05-01

Although contact hypersensitivity (CHS) has been considered a prototype of T cell-mediated immune reactions, recently a significant contribution of regulatory B cell subsets in the suppression of CHS has been demonstrated. CD22, one of the sialic acid-binding immunoglobulin-like lectins, is a B cell-specific molecule that negatively regulates BCR signaling. To clarify the roles of B cells in CHS, CHS in CD22(-/-) mice was investigated. CD22(-/-) mice showed delayed recovery from CHS reactions compared with that of wild-type mice. Transfer of wild-type peritoneal B-1a cells reversed the prolonged CHS reaction seen in CD22(-/-) mice, and this was blocked by the simultaneous injection with IL-10 receptor Ab. Although CD22(-/-) peritoneal B-1a cells were capable of producing IL-10 at wild-type levels, i.p. injection of differentially labeled wild-type/CD22(-/-) B cells demonstrated that a smaller number of CD22(-/-) B cells resided in lymphoid organs 5 d after CHS elicitation, suggesting a defect in survival or retention in activated CD22(-/-) peritoneal B-1 cells. Thus, our study reveals a regulatory role for peritoneal B-1a cells in CHS. Two distinct regulatory B cell subsets cooperatively inhibit CHS responses. Although splenic CD1d(hi)CD5(+) B cells have a crucial role in suppressing the acute exacerbating phase of CHS, peritoneal B-1a cells are likely to suppress the late remission phase as "regulatory B cells." CD22 deficiency results in disturbed CHS remission by impaired retention or survival of peritoneal B-1a cells that migrate into lymphoid organs.

Metalloproteinase pregnancy-associated plasma protein A is a critical growth regulatory factor during fetal development.

PubMed

Conover, Cheryl A; Bale, Laurie K; Overgaard, Michael T; Johnstone, Edward W; Laursen, Ulla H; Füchtbauer, Ernst-Martin; Oxvig, Claus; van Deursen, Jan

2004-03-01

Pregnancy-associated plasma protein A (PAPPA) is a metzincin superfamily metalloproteinase in the insulin-like growth factor (IGF) system. PAPPA increases IGF bioavailability and mitogenic effectiveness in vitro through regulated cleavage of IGF-binding protein 4 (IGFBP4). To determine its function in vivo, we generated PAPPA-null mice by gene targeting. Mice homozygous for targeted disruption of the PAPPA gene were viable but 60% the size of wild-type littermates at birth. The impact of the mutation was exerted during the early embryonic period prior to organogenesis, resulting in proportional dwarfism. PAPPA, IGF2 and IGFBP4 transcripts co-localized in wild-type embryos, and expression of IGF2 and IGFBP4 mRNA was not altered in PAPPA-deficient embryos. However, IGFBP4 proteolytic activity was completely lacking in fibroblasts derived from PAPPA-deficient embryos, and IGFBP4 effectively inhibited IGF-stimulated mitogenesis in these cells. These results provide the first direct evidence that PAPPA is an essential growth regulatory factor in vivo, and suggest a novel mechanism for regulated IGF bioavailability during early fetal development.

CNPY2 inhibits MYLIP-mediated AR protein degradation in prostate cancer cells.

PubMed

Ito, Saya; Ueno, Akihisa; Ueda, Takashi; Nakagawa, Hideo; Taniguchi, Hidefumi; Kayukawa, Naruhiro; Fujihara-Iwata, Atsuko; Hongo, Fumiya; Okihara, Koji; Ukimura, Osamu

2018-04-03

The androgen receptor (AR) is a ligand-dependent transcription factor that promotes prostate cancer (PC) cell growth through control of target gene expression. This report suggests that Canopy FGF signaling regulator 2 (CNPY2) controls AR protein levels in PC cells. We found that AR was ubiquitinated by an E3 ubiquitin ligase, myosin regulatory light chain interacting protein (MYLIP) and then degraded through the ubiquitin-proteasome pathway. CNPY2 decreased the ubiquitination activity of MYLIP by inhibition of interaction between MYLIP and UBE2D1, an E2 ubiquitin ligase. CNPY2 up-regulated gene expression of AR target genes such as KLK3 gene which encodes the prostate specific antigen (PSA) and promoted cell growth of PC cells. The cell growth inhibition by CNPY2 knockdown was rescued by AR overexpression. Furthermore, positive correlation of expression levels between CNPY2 and AR/AR target genes was observed in tissue samples from human prostate cancer patients. Together, these results suggested that CNPY2 promoted cell growth of PC cells by inhibition of AR protein degradation through MYLIP-mediated AR ubiquitination.

Signaling molecules involved in the transition of growth to development of Dictyostelium discoideum.

PubMed

Mir, Hina A; Rajawat, Jyotika; Pradhan, Shalmali; Begum, Rasheedunnisa

2007-03-01

The social amoeba Dictyostelium discoideum, a powerful paradigm provides clear insights into the regulation of growth and development. In addition to possessing complex individual cellular functions like a unicellular eukaryote, D. discoideum cells face the challenge of multicellular development. D. discoideum undergoes a relatively simple differentiation process mainly by cAMP mediated pathway. Despite this relative simplicity, the regulatory signaling pathways are as complex as those seen in metazoan development. However, the introduction of restriction-enzyme-mediated integration (REMI) technique to produce developmental gene knockouts has provided novel insights into the discovery of signaling molecules and their role in D. discoideum development. Cell cycle phase is an important aspect for differentiation of D. discoideum, as cells must reach a specific stage to enter into developmental phase and specific cell cycle regulators are involved in arresting growth phase genes and inducing the developmental genes. In this review, we present an overview of the signaling molecules involved in the regulation of growth to differentiation transition (GDT), molecular mechanism of early developmental events leading to generation of cAMP signal and components of cAMP relay system that operate in this paradigm.

IL-35 promotes pancreas cancer growth through enhancement of proliferation and inhibition of apoptosis: evidence for a role as an autocrine growth factor.

PubMed

Nicholl, Michael B; Ledgewood, Chelsea L; Chen, Xuhui; Bai, Qian; Qin, Chenglu; Cook, Kathryn M; Herrick, Elizabeth J; Diaz-Arias, Alberto; Moore, Bradley J; Fang, Yujiang

2014-12-01

Interleukin-35 (IL-35), an IL-12 cytokine family member, mediates the immune inhibitory function of regulatory T cells (Treg). We assayed the presence of IL-35 in paraffin-embedded human pancreas cancer (PCAN) and unexpectedly found IL-35 was expressed mainly by epithelial derived PCAN cells, but not by Treg. We further examined the expression and effect of exogenous IL-35 in human PCAN cell lines and found IL-35 promoted growth and inhibited apoptosis in PCAN cell lines. IL-35 induced proliferation correlated with an increase in cyclin B, cyclin D, cdk2, and cdk4 and a decrease in p27 expression, while inhibition of apoptosis was associated with an increase in Bcl-2 and a decrease in TRAILR1. We conclude IL-35 is produced by PCAN in vivo and promotes PCAN cell line growth in vitro. These results might indicate an important new role for IL-35 as an autocrine growth factor in PCAN growth. Copyright © 2014 Elsevier Ltd. All rights reserved.

Temporal transcriptional response to ethylene gas drives growth hormone cross-regulation in Arabidopsis

DOE PAGES

Chang, Katherine Noelani; Zhong, Shan; Weirauch, Matthew T.; ...

2013-06-11

The gaseous plant hormone ethylene regulates a multitude of growth and developmental processes. How the numerous growth control pathways are coordinated by the ethylene transcriptional response remains elusive. We characterized the dynamic ethylene transcriptional response by identifying targets of the master regulator of the ethylene signaling pathway, ETHYLENE INSENSITIVE3 (EIN3), using chromatin immunoprecipitation sequencing and transcript sequencing during a timecourse of ethylene treatment. Ethylene-induced transcription occurs in temporal waves regulated by EIN3, suggesting distinct layers of transcriptional control. EIN3 binding was found to modulate a multitude of downstream transcriptional cascades, including a major feedback regulatory circuitry of the ethylene signalingmore » pathway, as well as integrating numerous connections between most of the hormone mediated growth response pathways. These findings provide direct evidence linking each of the major plant growth and development networks in novel ways.« less

Small interfering RNA mediated knockdown of irisin suppresses food intake and modulates appetite regulatory peptides in zebrafish.

PubMed

Sundarrajan, Lakshminarasimhan; Unniappan, Suraj

2017-10-01

Irisin is a myokine encoded in fibronectin type III domain containing 5 (FNDC5). FNDC5 forms an integral part of the muscle post-exercise, and causes an increase in energy expenditure in mammals. Irisin is abundantly expressed in cardiac and skeletal muscles and is secreted upon activation of peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1 alpha). Irisin regulates feeding behaviour and cardiovascular function in mammals. More recently, irisin has gained importance as a potential biomarker for myocardial infarction due to its abundance in cardiac muscle. The goal of this research was to determine whether irisin influences feeding, and regulates appetite regulatory peptides in zebrafish. Intraperitoneal injection of irisin [0.1, 1, 10 and 100ng/g body weight (BW)] did not affect feeding, but its knockdown using siRNA (10ng/g BW) caused a significant reduction in food intake. Knockdown of irisin reduced ghrelin and orexin-A mRNA expression, and increased cocaine and amphetamine regulated transcript mRNA expression in zebrafish brain and gut. siRNA mediated knockdown of irisin also downregulated brain derived neurotrophic factor mRNA in zebrafish. The role of endogenous irisin on food intake is likely mediated by its actions on other metabolic peptides. Collectively, these results indicate that unaltered endogenous irisin is required to maintain food intake in zebrafish. Copyright © 2017 Elsevier Inc. All rights reserved.

Transforming growth factor-beta1 mediates cellular response to DNA damage in situ

NASA Technical Reports Server (NTRS)

Ewan, Kenneth B.; Henshall-Powell, Rhonda L.; Ravani, Shraddha A.; Pajares, Maria Jose; Arteaga, Carlos; Warters, Ray; Akhurst, Rosemary J.; Barcellos-Hoff, Mary Helen

2002-01-01

Transforming growth factor (TGF)-beta1 is rapidly activated after ionizing radiation, but its specific role in cellular responses to DNA damage is not known. Here we use Tgfbeta1 knockout mice to show that radiation-induced apoptotic response is TGF-beta1 dependent in the mammary epithelium, and that both apoptosis and inhibition of proliferation in response to DNA damage decrease as a function of TGF-beta1 gene dose in embryonic epithelial tissues. Because apoptosis in these tissues has been shown previously to be p53 dependent, we then examined p53 protein activation. TGF-beta1 depletion, by either gene knockout or by using TGF-beta neutralizing antibodies, resulted in decreased p53 Ser-18 phosphorylation in irradiated mammary gland. These data indicate that TGF-beta1 is essential for rapid p53-mediated cellular responses that mediate cell fate decisions in situ.

Revealing critical mechanisms of BR-mediated apple nursery tree growth using iTRAQ-based proteomic analysis.

PubMed

Zheng, Liwei; Ma, Juanjuan; Zhang, Lizhi; Gao, Cai; Zhang, Dong; Zhao, Caiping; Han, Mingyu

2018-02-20

Brassinosteroid is identified as an important hormone. However, information about brassinosteroid has not been fully elucidated, and few studies concerned its role in apple. The aim of this work was to study the role of brassinosteroid for apple tree growth. In our study, the effect of brassinosteroid on apple nursery tree was analyzed. The biomass, cell size and xylem content of apple nursery tree were obviously evaluated by brassinosteroid treatment; mineral elements contents, photosynthesis indexes, carbohydrate level and hormone contents were significantly high in brassinosteroid treated trees. To explore the molecular mechanisms of these phenotypic differences, iTRAQ-based quantitative proteomics were used to identify the expression profiles of proteins in apple nursery tree shoot tips in response to brassinosteroid at a key period (14days after brassinosteroid treatment). A total of 175 differentially expressed proteins were identified. They were mainly involved in chlorophyII biosynthesis, photosynthesis, carbohydrate metabolism, glycolysis, citric acid cycle, respiratory action, hormone signal, cell growth and ligin metabolism. The findings in this study indicate that brassinosteroid mediating apple nursery tree growth may be mainly through energy metabolism. Important biological processes identified here can be useful theoretical basis and provide new insights into the molecular mechanisms of brassinosteroid. Brassinosteroid is very important for plant growth and development. However, the molecular mechanism of brassinosteroid mediating growth process is not perfectly clear in plant, especially in apple nursery tree. We used a combination of physiological and bioinformatics analysis to investigate the effects of brassinosteroid on apple nursery tree growth and development. The data reported here demonstrated that brassinosteroid regulates apple nursery tree growth mainly through energy metabolism. Therefore it can provide a theoretical basis from energy

Seed-Mediated Growth of Gold Nanocrystals: Changes to the Crystallinity or Morphology as Induced by the Treatment of Seeds with a Sulfur Species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Yiqun; Luo, Ming; Tao, Jing

We report our observation of changes to the crystallinity or morphology during seed-mediated growth of Au nanocrystals. When single-crystal Au seeds with a spherical or rod-like shape were treated with a chemical species such as S₂O₃²⁻ ions, twin defects were developed during the growth process to generate multiply twinned nanostructures. X-ray photoelectron spectroscopy analysis indicated that the S₂O₃²⁻ ions were chemisorbed on the surfaces of the seeds during the treatment. The chemisorbed S₂O₃²⁻ ions somehow influenced the crystallization of Au atoms added onto the surface during a growth process, leading to the formation of twin defects. In contrast to themore » spherical and rod-like Au seeds, the single-crystal structure was retained to generate a concave morphology when single-crystal Au seeds with a cubic or octahedral shape were used for a similar treatment and then seed-mediated growth. The different outcomes are likely related to the difference in spatial distribution of S₂O₃²⁻ ions chemisorbed on the surface of a seed. This approach based on surface modification is potentially extendable to other noble metals for engineering the crystallinity and morphology of nanocrystals formed via seed-mediated growth.« less

Seed-Mediated Growth of Gold Nanocrystals: Changes to the Crystallinity or Morphology as Induced by the Treatment of Seeds with a Sulfur Species

DOE PAGES

Zheng, Yiqun; Luo, Ming; Tao, Jing; ...

2014-12-11

We report our observation of changes to the crystallinity or morphology during seed-mediated growth of Au nanocrystals. When single-crystal Au seeds with a spherical or rod-like shape were treated with a chemical species such as S₂O₃²⁻ ions, twin defects were developed during the growth process to generate multiply twinned nanostructures. X-ray photoelectron spectroscopy analysis indicated that the S₂O₃²⁻ ions were chemisorbed on the surfaces of the seeds during the treatment. The chemisorbed S₂O₃²⁻ ions somehow influenced the crystallization of Au atoms added onto the surface during a growth process, leading to the formation of twin defects. In contrast to themore » spherical and rod-like Au seeds, the single-crystal structure was retained to generate a concave morphology when single-crystal Au seeds with a cubic or octahedral shape were used for a similar treatment and then seed-mediated growth. The different outcomes are likely related to the difference in spatial distribution of S₂O₃²⁻ ions chemisorbed on the surface of a seed. This approach based on surface modification is potentially extendable to other noble metals for engineering the crystallinity and morphology of nanocrystals formed via seed-mediated growth.« less

Regulatory Response to Carbon Starvation in Caulobacter crescentus

PubMed Central

Britos, Leticia; Abeliuk, Eduardo; Taverner, Thomas; Lipton, Mary; McAdams, Harley; Shapiro, Lucy

2011-01-01

Bacteria adapt to shifts from rapid to slow growth, and have developed strategies for long-term survival during prolonged starvation and stress conditions. We report the regulatory response of C. crescentus to carbon starvation, based on combined high-throughput proteome and transcriptome analyses. Our results identify cell cycle changes in gene expression in response to carbon starvation that involve the prominent role of the FixK FNR/CAP family transcription factor and the CtrA cell cycle regulator. Notably, the SigT ECF sigma factor mediates the carbon starvation-induced degradation of CtrA, while activating a core set of general starvation-stress genes that respond to carbon starvation, osmotic stress, and exposure to heavy metals. Comparison of the response of swarmer cells and stalked cells to carbon starvation revealed four groups of genes that exhibit different expression profiles. Also, cell pole morphogenesis and initiation of chromosome replication normally occurring at the swarmer-to-stalked cell transition are uncoupled in carbon-starved cells. PMID:21494595

Transcription Profiles Reveal Sugar and Hormone Signaling Pathways Mediating Flower Induction in Apple (Malus domestica Borkh.).

PubMed

Xing, Li-Bo; Zhang, Dong; Li, You-Mei; Shen, Ya-Wen; Zhao, Cai-Ping; Ma, Juan-Juan; An, Na; Han, Ming-Yu

2015-10-01

Flower induction in apple (Malus domestica Borkh.) is regulated by complex gene networks that involve multiple signal pathways to ensure flower bud formation in the next year, but the molecular determinants of apple flower induction are still unknown. In this research, transcriptomic profiles from differentiating buds allowed us to identify genes potentially involved in signaling pathways that mediate the regulatory mechanisms of flower induction. A hypothetical model for this regulatory mechanism was obtained by analysis of the available transcriptomic data, suggesting that sugar-, hormone- and flowering-related genes, as well as those involved in cell-cycle induction, participated in the apple flower induction process. Sugar levels and metabolism-related gene expression profiles revealed that sucrose is the initiation signal in flower induction. Complex hormone regulatory networks involved in cytokinin (CK), abscisic acid (ABA) and gibberellic acid pathways also induce apple flower formation. CK plays a key role in the regulation of cell formation and differentiation, and in affecting flowering-related gene expression levels during these processes. Meanwhile, ABA levels and ABA-related gene expression levels gradually increased, as did those of sugar metabolism-related genes, in developing buds, indicating that ABA signals regulate apple flower induction by participating in the sugar-mediated flowering pathway. Furthermore, changes in sugar and starch deposition levels in buds can be affected by ABA content and the expression of the genes involved in the ABA signaling pathway. Thus, multiple pathways, which are mainly mediated by crosstalk between sugar and hormone signals, regulate the molecular network involved in bud growth and flower induction in apple trees. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

Temporal global expression data reveal known and novel salicylate-impacted processes and regulators mediating powdery mildew growth and reproduction on Arabidopsis.

PubMed

Chandran, Divya; Tai, Yu Chuan; Hather, Gregory; Dewdney, Julia; Denoux, Carine; Burgess, Diane G; Ausubel, Frederick M; Speed, Terence P; Wildermuth, Mary C

2009-03-01

Salicylic acid (SA) is a critical mediator of plant innate immunity. It plays an important role in limiting the growth and reproduction of the virulent powdery mildew (PM) Golovinomyces orontii on Arabidopsis (Arabidopsis thaliana). To investigate this later phase of the PM interaction and the role played by SA, we performed replicated global expression profiling for wild-type and SA biosynthetic mutant isochorismate synthase1 (ics1) Arabidopsis from 0 to 7 d after infection. We found that ICS1-impacted genes constitute 3.8% of profiled genes, with known molecular markers of Arabidopsis defense ranked very highly by the multivariate empirical Bayes statistic (T(2) statistic). Functional analyses of T(2)-selected genes identified statistically significant PM-impacted processes, including photosynthesis, cell wall modification, and alkaloid metabolism, that are ICS1 independent. ICS1-impacted processes include redox, vacuolar transport/secretion, and signaling. Our data also support a role for ICS1 (SA) in iron and calcium homeostasis and identify components of SA cross talk with other phytohormones. Through our analysis, 39 novel PM-impacted transcriptional regulators were identified. Insertion mutants in one of these regulators, PUX2 (for plant ubiquitin regulatory X domain-containing protein 2), results in significantly reduced reproduction of the PM in a cell death-independent manner. Although little is known about PUX2, PUX1 acts as a negative regulator of Arabidopsis CDC48, an essential AAA-ATPase chaperone that mediates diverse cellular activities, including homotypic fusion of endoplasmic reticulum and Golgi membranes, endoplasmic reticulum-associated protein degradation, cell cycle progression, and apoptosis. Future work will elucidate the functional role of the novel regulator PUX2 in PM resistance.

Methylglyoxal, a glycolysis side-product, induces Hsp90 glycation and YAP-mediated tumor growth and metastasis

PubMed Central

Nokin, Marie-Julie; Durieux, Florence; Peixoto, Paul; Chiavarina, Barbara; Peulen, Olivier; Blomme, Arnaud; Turtoi, Andrei; Costanza, Brunella; Smargiasso, Nicolas; Baiwir, Dominique; Scheijen, Jean L; Schalkwijk, Casper G; Leenders, Justine; De Tullio, Pascal; Bianchi, Elettra; Thiry, Marc; Uchida, Koji; Spiegel, David A; Cochrane, James R; Hutton, Craig A; De Pauw, Edwin; Delvenne, Philippe; Belpomme, Dominique; Castronovo, Vincent; Bellahcène, Akeila

2016-01-01

Metabolic reprogramming toward aerobic glycolysis unavoidably induces methylglyoxal (MG) formation in cancer cells. MG mediates the glycation of proteins to form advanced glycation end products (AGEs). We have recently demonstrated that MG-induced AGEs are a common feature of breast cancer. Little is known regarding the impact of MG-mediated carbonyl stress on tumor progression. Breast tumors with MG stress presented with high nuclear YAP, a key transcriptional co-activator regulating tumor growth and invasion. Elevated MG levels resulted in sustained YAP nuclear localization/activity that could be reverted using Carnosine, a scavenger for MG. MG treatment affected Hsp90 chaperone activity and decreased its binding to LATS1, a key kinase of the Hippo pathway. Cancer cells with high MG stress showed enhanced growth and metastatic potential in vivo. These findings reinforce the cumulative evidence pointing to hyperglycemia as a risk factor for cancer incidence and bring renewed interest in MG scavengers for cancer treatment. DOI: http://dx.doi.org/10.7554/eLife.19375.001 PMID:27759563

Primary inhibition of hypocotyl growth and phototropism depend differently on phototropin-mediated increases in cytoplasmic calcium induced by blue light.

PubMed

Folta, Kevin M; Lieg, Erin J; Durham, Tessa; Spalding, Edgar P

2003-12-01

The phototropin photoreceptors transduce blue-light signals into several physiological and developmental responses in plants. A transient rise in cytoplasmic calcium (Ca2+) that begins within seconds of phototropin 1 (phot1) excitation is believed to be an important element in the transduction pathways leading to one or more of the phot1-dependent responses. The goal of the present work was to determine whether the Ca2+ response was necessary for (a). the inhibition of hypocotyl elongation that develops within minutes of the irradiation, and (b). hypocotyl phototropism (curved growth of the stem in response to asymmetric illumination). After determining that pulses of light delivering photon fluences of between 1 and 1000 micromol m-2 induced growth inhibition mediated by phot1 without significant interference from other photosensory pathways, the effect of blocking the Ca2+ rise was assessed. Treatment of seedlings with a Ca2+ chelator prevented the rise in cytoplasmic Ca2+ and prevented phot1-mediated growth inhibition. However, the same chelator treatment did not impair phot1-mediated phototropism. Thus, it appears that the early, transient rise in cytoplasmic Ca2+ is an important intermediary process in at least one but not all phot1-signaling pathways.

Epidermal growth factor induction of front–rear polarity and migration in keratinocytes is mediated by integrin-linked kinase and ELMO2

PubMed Central

Ho, Ernest; Dagnino, Lina

2012-01-01

Epidermal growth factor (EGF) is a potent chemotactic and mitogenic factor for epidermal keratinocytes, and these properties are central for normal epidermal regeneration after injury. The involvement of mitogen-activated protein kinases as mediators of the proliferative effects of EGF is well established. However, the molecular mechanisms that mediate motogenic responses to this growth factor are not clearly understood. An obligatory step for forward cell migration is the development of front–rear polarity and formation of lamellipodia at the leading edge. We show that stimulation of epidermal keratinocytes with EGF, but not with other growth factors, induces development of front–rear polarity and directional migration through a pathway that requires integrin-linked kinase (ILK), Engulfment and Cell Motility-2 (ELMO2), integrin β1, and Rac1. Furthermore, EGF induction of front–rear polarity and chemotaxis require the tyrosine kinase activity of the EGF receptor and are mediated by complexes containing active RhoG, ELMO2, and ILK. Our findings reveal a novel link between EGF receptor stimulation, ILK-containing complexes, and activation of small Rho GTPases necessary for acquisition of front–rear polarity and forward movement. PMID:22160594

Epidermal growth factor induction of front-rear polarity and migration in keratinocytes is mediated by integrin-linked kinase and ELMO2.

PubMed

Ho, Ernest; Dagnino, Lina

2012-02-01

Epidermal growth factor (EGF) is a potent chemotactic and mitogenic factor for epidermal keratinocytes, and these properties are central for normal epidermal regeneration after injury. The involvement of mitogen-activated protein kinases as mediators of the proliferative effects of EGF is well established. However, the molecular mechanisms that mediate motogenic responses to this growth factor are not clearly understood. An obligatory step for forward cell migration is the development of front-rear polarity and formation of lamellipodia at the leading edge. We show that stimulation of epidermal keratinocytes with EGF, but not with other growth factors, induces development of front-rear polarity and directional migration through a pathway that requires integrin-linked kinase (ILK), Engulfment and Cell Motility-2 (ELMO2), integrin β1, and Rac1. Furthermore, EGF induction of front-rear polarity and chemotaxis require the tyrosine kinase activity of the EGF receptor and are mediated by complexes containing active RhoG, ELMO2, and ILK. Our findings reveal a novel link between EGF receptor stimulation, ILK-containing complexes, and activation of small Rho GTPases necessary for acquisition of front-rear polarity and forward movement.

Dual Role of GM-CSF as a Pro-Inflammatory and a Regulatory Cytokine: Implications for Immune Therapy

PubMed Central

Bhattacharya, Palash; Budnick, Isadore; Singh, Medha; Thiruppathi, Muthusamy; Alharshawi, Khaled; Elshabrawy, Hatem; Holterman, Mark J.

2015-01-01

Granulocyte macrophage colony stimulating factor (GM-CSF) is generally recognized as an inflammatory cytokine. Its inflammatory activity is primarily due its role as a growth and differentiation factor for granulocyte and macrophage populations. In this capacity, among other clinical applications, it has been used to bolster anti-tumor immune responses. GM-CSF-mediated inflammation has also been implicated in certain types of autoimmune diseases, including rheumatoid arthritis and multiple sclerosis. Thus, agents that can block GM-CSF or its receptor have been used as anti-inflammatory therapies. However, a review of literature reveals that in many situations GM-CSF can act as an anti-inflammatory/regulatory cytokine. We and others have shown that GM-CSF can modulate dendritic cell differentiation to render them “tolerogenic,” which, in turn, can increase regulatory T-cell numbers and function. Therefore, the pro-inflammatory and regulatory effects of GM-CSF appear to depend on the dose and the presence of other relevant cytokines in the context of an immune response. A thorough understanding of the various immunomodulatory effects of GM-CSF will facilitate more appropriate use and thus further enhance its clinical utility. PMID:25803788

Arabidopsis JAGGED links floral organ patterning to tissue growth by repressing Kip-related cell cycle inhibitors.

PubMed

Schiessl, Katharina; Muiño, Jose M; Sablowski, Robert

2014-02-18

Plant morphogenesis requires coordinated cytoplasmic growth, oriented cell wall extension, and cell cycle progression, but it is debated which of these processes are primary drivers for tissue growth and directly targeted by developmental genes. Here, we used ChIP high-throughput sequencing combined with transcriptome analysis to identify global target genes of the Arabidopsis transcription factor JAGGED (JAG), which promotes growth of the distal region of floral organs. Consistent with the roles of JAG during organ initiation and subsequent distal organ growth, we found that JAG directly repressed genes involved in meristem development, such as CLAVATA1 and HANABA TARANU, and genes involved in the development of the basal region of shoot organs, such as BLADE ON PETIOLE 2 and the GROWTH REGULATORY FACTOR pathway. At the same time, JAG regulated genes involved in tissue polarity, cell wall modification, and cell cycle progression. In particular, JAG directly repressed KIP RELATED PROTEIN 4 (KRP4) and KRP2, which control the transition to the DNA synthesis phase (S-phase) of the cell cycle. The krp2 and krp4 mutations suppressed jag defects in organ growth and in the morphology of petal epidermal cells, showing that the interaction between JAG and KRP genes is functionally relevant. Our work reveals that JAG is a direct mediator between genetic pathways involved in organ patterning and cellular functions required for tissue growth, and it shows that a regulatory gene shapes plant organs by releasing a constraint on S-phase entry.

Mediation of wound-related Rous sarcoma virus tumorigenesis by TFG (transforming growth factor)-. beta

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sieweke, M.H.; Bissell, M.J.; Thompson, N.L.

1990-06-29

In Rous sarcoma virus (RSV)-infected chickens, wounding leads to tumor formation with nearly 100% frequency in tissues that would otherwise remain tumor-free. Identifying molecular mediators of this phenomenon should yield important clues to the mechanisms involved in RSV tumorigenesis. Immunohistochemical staining showed that TGF-{beta} is present locally shortly after wounding, but not in unwounded controls. In addition, subcutaneous administration of recombinant transforming growth factor {beta}1 (TGF-{beta}1) could substitute completely for wounding in tumor induction. A treatment protocol of four doses of 800 nanograms of TGF-{beta} resulted in v-src-expressing tumors with 100% frequency; four doses of only 10 nanograms still ledmore » to tumor formation in 80% of the animals. This effect was specific, as other growth factors with suggested roles in would healing did not elicit the same response. Epidermal growth factor (EGF) or TGF-{alpha} had no effect, and platelet-derived growth factor (PDGF) or insulin-like growth factor-1 (IGF-1) yielded only occasional tumors after longer latency. TGF-{beta} release during the would-healing response may thus be a critical event that creates a conducive environment for RSV tumorigenesis and may act as a cofactor for transformation in this system. 31 refs., 3 figs., 2 tabs.« less

Four regulatory elements in the human c-fos promoter mediate transactivation by HTLV-1 Tax protein.

PubMed

Alexandre, C; Verrier, B

1991-04-01

Expression of the human c-fos proto-oncogene is activated in trans by the Tax protein encoded by human T-cell leukemia virus type-1 (HTLV-1). Indeed, we show here that a HeLa clone stably transfected by Tax expresses Fos at a high level. We also show that multiple elements of the human c-fos promoter, i.e. the v-sis conditioned medium inducible element (SIE), the dyad symmetry element (DSE) necessary for growth factor induction, the octanucleotide direct repeat element (DR), and the cyclic AMP response element (CRE) centred at -60, can all mediate Tax transactivation. In the DSE, the 10bp central core that binds the serum response factor (SRF) is, by itself, sufficient to mediate Tax transactivation. Moreover, a CRE-binding protein is involved in Tax activation through the CRE-60 element. Since Fos is a transregulator of cellular genes, our results suggest that the oncoprotein plays a crucial role in T-cell transformation by HTLV-1 in conjunction with other Tax-inducible genes.

The putative guanine nucleotide exchange factor RicA mediates upstream signaling for growth and development in Aspergillus.

PubMed

Kwon, Nak-Jung; Park, Hee-Soo; Jung, Seunho; Kim, Sun Chang; Yu, Jae-Hyuk

2012-11-01

Heterotrimeric G proteins (G proteins) govern growth, development, and secondary metabolism in various fungi. Here, we characterized ricA, which encodes a putative GDP/GTP exchange factor for G proteins in the model fungus Aspergillus nidulans and the opportunistic human pathogen Aspergillus fumigatus. In both species, ricA mRNA accumulates during vegetative growth and early developmental phases, but it is not present in spores. The deletion of ricA results in severely impaired colony growth and the total (for A. nidulans) or near (for A. fumigatus) absence of asexual sporulation (conidiation). The overexpression (OE) of the A. fumigatus ricA gene (AfricA) restores growth and conidiation in the ΔAnricA mutant to some extent, indicating partial conservation of RicA function in Aspergillus. A series of double mutant analyses revealed that the removal of RgsA (an RGS protein of the GanB Gα subunit), but not sfgA, flbA, rgsB, or rgsC, restored vegetative growth and conidiation in ΔAnricA. Furthermore, we found that RicA can physically interact with GanB in yeast and in vitro. Moreover, the presence of two copies or OE of pkaA suppresses the profound defects caused by ΔAnricA, indicating that RicA-mediated growth and developmental signaling is primarily through GanB and PkaA in A. nidulans. Despite the lack of conidiation, brlA and vosA mRNAs accumulated to normal levels in the ΔricA mutant. In addition, mutants overexpressing fluG or brlA (OEfluG or OEbrlA) failed to restore development in the ΔAnricA mutant. These findings suggest that the commencement of asexual development requires unknown RicA-mediated signaling input in A. nidulans.

The Putative Guanine Nucleotide Exchange Factor RicA Mediates Upstream Signaling for Growth and Development in Aspergillus

PubMed Central

Kwon, Nak-Jung; Park, Hee-Soo; Jung, Seunho; Kim, Sun Chang

2012-01-01

Heterotrimeric G proteins (G proteins) govern growth, development, and secondary metabolism in various fungi. Here, we characterized ricA, which encodes a putative GDP/GTP exchange factor for G proteins in the model fungus Aspergillus nidulans and the opportunistic human pathogen Aspergillus fumigatus. In both species, ricA mRNA accumulates during vegetative growth and early developmental phases, but it is not present in spores. The deletion of ricA results in severely impaired colony growth and the total (for A. nidulans) or near (for A. fumigatus) absence of asexual sporulation (conidiation). The overexpression (OE) of the A. fumigatus ricA gene (AfricA) restores growth and conidiation in the ΔAnricA mutant to some extent, indicating partial conservation of RicA function in Aspergillus. A series of double mutant analyses revealed that the removal of RgsA (an RGS protein of the GanB Gα subunit), but not sfgA, flbA, rgsB, or rgsC, restored vegetative growth and conidiation in ΔAnricA. Furthermore, we found that RicA can physically interact with GanB in yeast and in vitro. Moreover, the presence of two copies or OE of pkaA suppresses the profound defects caused by ΔAnricA, indicating that RicA-mediated growth and developmental signaling is primarily through GanB and PkaA in A. nidulans. Despite the lack of conidiation, brlA and vosA mRNAs accumulated to normal levels in the ΔricA mutant. In addition, mutants overexpressing fluG or brlA (OEfluG or OEbrlA) failed to restore development in the ΔAnricA mutant. These findings suggest that the commencement of asexual development requires unknown RicA-mediated signaling input in A. nidulans. PMID:23002107

The effect of regulatory mode on procrastination: Bi-stable parahippocampus connectivity with dorsal anterior cingulate and anterior prefrontal cortex.

PubMed

Zhang, Chenyan; Ni, Yan; Feng, Tingyong

2017-06-30

Previous research has elucidated that procrastination can be influenced by regulatory mode orientations. However, the neural mechanism of regulatory modes affecting procrastination is not well understood. To address this question, we employed resting-state functional magnetic resonance imaging (RS-fMRI) to test the influence of two regulatory modes (assessment and locomotion) on procrastination. The behavioral results showed that procrastination was positively correlated with assessment orientation but negatively correlated with locomotion orientation. Neuroimaging results indicated that the functional connectivity between parahippocampal cortex (PHC) and dorsal anterior cingulate (dACC) was negatively correlated with assessment scores, while the functional connectivity between anterior prefrontal cortex (aPFC) and parahippocampal cortex (PHC) was negatively correlated with locomotion scores. Critically, mediation analysis showed that the different effects of two distinct regulatory modes on procrastination were mediated by PHC-dACC and aPFC-PHC functional connectivity respectively. These results suggested that people's procrastination could be predicted by regulatory mode orientations, which is mediated by PHC connectivity with dACC and aPFC respectively. The present study extends our knowledge on procrastination and provides neural mechanism for understanding the link between regulatory mode orientations and procrastination. Copyright © 2017. Published by Elsevier B.V.

Nanos-mediated repression of hid protects larval sensory neurons after a global switch in sensitivity to apoptotic signals

PubMed Central

Bhogal, Balpreet; Plaza-Jennings, Amara

2016-01-01

Dendritic arbor morphology is a key determinant of neuronal function. Once established, dendrite branching patterns must be maintained as the animal develops to ensure receptive field coverage. The translational repressors Nanos (Nos) and Pumilio (Pum) are required to maintain dendrite growth and branching of Drosophila larval class IV dendritic arborization (da) neurons, but their specific regulatory role remains unknown. We show that Nos-Pum-mediated repression of the pro-apoptotic gene head involution defective (hid) is required to maintain a balance of dendritic growth and retraction in class IV da neurons and that upregulation of hid results in decreased branching because of an increase in caspase activity. The temporal requirement for nos correlates with an ecdysone-triggered switch in sensitivity to apoptotic stimuli that occurs during the mid-L3 transition. We find that hid is required during pupariation for caspase-dependent pruning of class IV da neurons and that Nos and Pum delay pruning. Together, these results suggest that Nos and Pum provide a crucial neuroprotective regulatory layer to ensure that neurons behave appropriately in response to developmental cues. PMID:27256879

Penfluridol suppresses glioblastoma tumor growth by Akt-mediated inhibition of GLI1

PubMed Central

Ranjan, Alok; Srivastava, Sanjay K.

2017-01-01

Glioblastoma (GBM) is the most common brain tumor with poor survival rate. Our results show that penfluridol, an antipsychotic drug significantly reduced the survival of ten adult and pediatric glioblastoma cell lines with IC50 ranging 2–5 μM after 72 hours of treatment and induced apoptosis. Penfluridol treatment suppressed the phosphorylation of Akt at Ser473 and reduced the expression of GLI1, OCT4, Nanog and Sox2 in several glioblastoma cell lines in a concentration-dependent manner. Inhibiting Akt with LY294002 and siRNA, or inhibiting GLI1 using GANT61, cyclopamine, siRNA and CRISPR/Cas9 resulted in enhanced cell growth suppressive effects of penfluridol. On the other hand, overexpression of GLI1 significantly attenuated the effects of penfluridol. Our results further demonstrated that penfluridol treatment inhibited the growth of U87MG tumors by 65% and 72% in subcutaneous and intracranial in vivo glioblastoma tumor models respectively. Immunohistochemical and western blot analysis of tumors revealed reduced pAkt (Ser 473), GLI1, OCT4 and increase in caspase-3 cleavage and TUNEL staining, confirming in vitro findings. Taken together, our results indicate that overall glioblastoma tumor growth suppression by penfluridol was associated with Akt-mediated inhibition of GLI1. PMID:28380428

Executive functioning as a mediator of conduct problems prevention in children of homeless families residing in temporary supportive housing: a parallel process latent growth modeling approach.

PubMed

Piehler, Timothy F; Bloomquist, Michael L; August, Gerald J; Gewirtz, Abigail H; Lee, Susanne S; Lee, Wendy S C

2014-01-01

A culturally diverse sample of formerly homeless youth (ages 6-12) and their families (n = 223) participated in a cluster randomized controlled trial of the Early Risers conduct problems prevention program in a supportive housing setting. Parents provided 4 annual behaviorally-based ratings of executive functioning (EF) and conduct problems, including at baseline, over 2 years of intervention programming, and at a 1-year follow-up assessment. Using intent-to-treat analyses, a multilevel latent growth model revealed that the intervention group demonstrated reduced growth in conduct problems over the 4 assessment points. In order to examine mediation, a multilevel parallel process latent growth model was used to simultaneously model growth in EF and growth in conduct problems along with intervention status as a covariate. A significant mediational process emerged, with participation in the intervention promoting growth in EF, which predicted negative growth in conduct problems. The model was consistent with changes in EF fully mediating intervention-related changes in youth conduct problems over the course of the study. These findings highlight the critical role that EF plays in behavioral change and lends further support to its importance as a target in preventive interventions with populations at risk for conduct problems.

Immunosuppressive Environment in Basal Cell Carcinoma: The Role of Regulatory T Cells.

PubMed

Omland, Silje H; Nielsen, Patricia S; Gjerdrum, Lise M R; Gniadecki, Robert

2016-11-02

Interaction between tumour survival tactics and anti-tumour immune response is a major determinant for cancer growth. Regulatory T cells (T-regs) contribute to tumour immune escape, but their role in basal cell carcinoma (BCC) is not understood. The fraction of T-regs among T cells was analysed by immunohistochemistry followed by automated image analysis in facial BCC, peritumoural skin and normal, buttock skin. Quantitative real-time PCR (qRT-PCR) was performed for FOXP3 and cytokines involved in T-reg attraction and T-cell activation. T-regs comprised 45% of CD4-cells surrounding BCC. FOXP3 was highly expressed in BCC, but absent in buttock skin. Unexpectedly, expression of FOXP3 was increased in peritumoural skin, with the FOXP3/CD3 fractions exceeding those of BCC (p?=?0.0065). Transforming growth factor (TGF)-? and T-reg chemokine expression was increased in BCC and peritumoural skin, but not in buttock skin, with expression levels correlating with FOXP3. T-regs are abundantly present both in BCC and in peritumoural skin, mediating an immunosuppressed microenvironment permissive for skin cancer.

Tail and Kinase Modules Differently Regulate Core Mediator Recruitment and Function In Vivo.

PubMed

Jeronimo, Célia; Langelier, Marie-France; Bataille, Alain R; Pascal, John M; Pugh, B Franklin; Robert, François

2016-11-03

Mediator is a highly conserved transcriptional coactivator organized into four modules, namely Tail, Middle, Head, and Kinase (CKM). Previous work suggests regulatory roles for Tail and CKM, but an integrated model for these activities is lacking. Here, we analyzed the genome-wide distribution of Mediator subunits in wild-type and mutant yeast cells in which RNA polymerase II promoter escape is blocked, allowing detection of transient Mediator forms. We found that although all modules are recruited to upstream activated regions (UAS), assembly of Mediator within the pre-initiation complex is accompanied by the release of CKM. Interestingly, our data show that CKM regulates Mediator-UAS interaction rather than Mediator-promoter association. In addition, although Tail is required for Mediator recruitment to UAS, Tailless Mediator nevertheless interacts with core promoters. Collectively, our data suggest that the essential function of Mediator is mediated by Head and Middle at core promoters, while Tail and CKM play regulatory roles. Copyright © 2016 Elsevier Inc. All rights reserved.

The OXI1 Kinase Pathway Mediates Piriformospora indica-Induced Growth Promotion in Arabidopsis

PubMed Central

Camehl, Iris; Drzewiecki, Corinna; Vadassery, Jyothilakshmi; Shahollari, Bationa; Sherameti, Irena; Forzani, Celine; Munnik, Teun; Hirt, Heribert; Oelmüller, Ralf

2011-01-01

Piriformospora indica is an endophytic fungus that colonizes roots of many plant species and promotes growth and resistance to certain plant pathogens. Despite its potential use in agriculture, little is known on the molecular basis of this beneficial plant-fungal interaction. In a genetic screen for plants, which do not show a P. indica- induced growth response, we isolated an Arabidopsis mutant in the OXI1 (Oxidative Signal Inducible1) gene. OXI1 has been characterized as a protein kinase which plays a role in pathogen response and is regulated by H2O2 and PDK1 (3-PHOSPHOINOSITIDE-DEPENDENT PROTEIN KINASE1). A genetic analysis showed that double mutants of the two closely related PDK1.1 and PDK1.2 genes are defective in the growth response to P. indica. While OXI1 and PDK1 gene expression is upregulated in P. indica-colonized roots, defense genes are downregulated, indicating that the fungus suppresses plant defense reactions. PDK1 is activated by phosphatidic acid (PA) and P. indica triggers PA synthesis in Arabidopsis plants. Under beneficial co-cultivation conditions, H2O2 formation is even reduced by the fungus. Importantly, phospholipase D (PLD)α1 or PLDδ mutants, which are impaired in PA synthesis do not show growth promotion in response to fungal infection. These data establish that the P. indica-stimulated growth response is mediated by a pathway consisting of the PLD-PDK1-OXI1 cascade. PMID:21625539

Temporal transcriptional response to ethylene gas drives growth hormone cross-regulation in Arabidopsis

PubMed Central

Chang, Katherine Noelani; Zhong, Shan; Weirauch, Matthew T; Hon, Gary; Pelizzola, Mattia; Li, Hai; Huang, Shao-shan Carol; Schmitz, Robert J; Urich, Mark A; Kuo, Dwight; Nery, Joseph R; Qiao, Hong; Yang, Ally; Jamali, Abdullah; Chen, Huaming; Ideker, Trey; Ren, Bing; Bar-Joseph, Ziv; Hughes, Timothy R; Ecker, Joseph R

2013-01-01

The gaseous plant hormone ethylene regulates a multitude of growth and developmental processes. How the numerous growth control pathways are coordinated by the ethylene transcriptional response remains elusive. We characterized the dynamic ethylene transcriptional response by identifying targets of the master regulator of the ethylene signaling pathway, ETHYLENE INSENSITIVE3 (EIN3), using chromatin immunoprecipitation sequencing and transcript sequencing during a timecourse of ethylene treatment. Ethylene-induced transcription occurs in temporal waves regulated by EIN3, suggesting distinct layers of transcriptional control. EIN3 binding was found to modulate a multitude of downstream transcriptional cascades, including a major feedback regulatory circuitry of the ethylene signaling pathway, as well as integrating numerous connections between most of the hormone mediated growth response pathways. These findings provide direct evidence linking each of the major plant growth and development networks in novel ways. DOI: http://dx.doi.org/10.7554/eLife.00675.001 PMID:23795294

Glycogen Synthase Kinase 3 Inactivation Induces Cell Senescence through Sterol Regulatory Element Binding Protein 1-Mediated Lipogenesis in Chang Cells.

PubMed

Kim, You-Mie; Song, Insun; Seo, Yong-Hak; Yoon, Gyesoon

2013-12-01

Enhanced lipogenesis plays a critical role in cell senescence via induction of expression of the mature form of sterol regulatory element binding protein 1 (SREBP1), which contributes to an increase in organellar mass, one of the indicators of senescence. We investigated the molecular mechanisms by which signaling molecules control SREBP1-mediated lipogenesis and senescence. We developed cellular models for stress-induced senescence, by exposing Chang cells, which are immortalized human liver cells, to subcytotoxic concentrations (200 µM) of deferoxamine (DFO) and H2O2. In this model of stress-induced cell senescence using DFO and H2O2, the phosphorylation profile of glycogen synthase kinase 3α (GSK3α) and β corresponded closely to the expression profile of the mature form of SREBP-1 protein. Inhibition of GSK3 with a subcytotoxic concentration of the selective GSK3 inhibitor SB415286 significantly increased mature SREBP1 expression, as well as lipogenesis and organellar mass. In addition, GSK3 inhibition was sufficient to induce senescence in Chang cells. Suppression of GSK3 expression with siRNAs specific to GSK3α and β also increased mature SREBP1 expression and induced senescence. Finally, blocking lipogenesis with fatty acid synthase inhibitors (cerulenin and C75) and siRNA-mediated silencing of SREBP1 and ATP citrate lyase (ACL) significantly attenuated GSK3 inhibition-induced senescence. GSK3 inactivation is an important upstream event that induces SREBP1-mediated lipogenesis and consequent cell senescence.

Drug-device combination products: regulatory landscape and market growth.

PubMed

Bayarri, L

2015-08-01

Combination products are therapeutic and diagnostic products that combine drugs, devices and/or biological products, leading to safer and more effective treatments thanks to careful and precise drug targeting, local administration and individualized therapy. These technologies can especially benefit patients suffering from serious diseases and conditions such as cancer, heart disease, multiple sclerosis and diabetes, among others. On the other hand, drug-device combination products have also introduced a new dynamic in medical product development, regulatory approval and corporate interaction. Due to the increasing integration of drugs and devices observed in the latest generation of combination products, regulatory agencies have developed specific competences and regulations over the last decade. Manufacturers are required to fully understand the specific requirements in each country in order to ensure timely and accurate market access of new combination products, and the development of combination products involves a very specific pattern of interactions between manufacturers and regulatory agencies. The increased sophistication of the products brought to market over the last couple of decades has accentuated the need to develop drugs and devices collaboratively using resources from both industries, fostering the need of business partnering and technology licensing. This review will provide a global overview of the market trends, as well as (in the last section) an analysis of the drug-device combination products approved by the FDA during the latest 5 years. Copyright 2015 Prous Science, S.A.U. or its licensors. All rights reserved.

The Mediator complex of Caenorhabditis elegans: insights into the developmental and physiological roles of a conserved transcriptional coregulator

PubMed Central

Grants, Jennifer M.; Goh, Grace Y. S.; Taubert, Stefan

2015-01-01

The Mediator multiprotein complex (‘Mediator’) is an important transcriptional coregulator that is evolutionarily conserved throughout eukaryotes. Although some Mediator subunits are essential for the transcription of all protein-coding genes, others influence the expression of only subsets of genes and participate selectively in cellular signaling pathways. Here, we review the current knowledge of Mediator subunit function in the nematode Caenorhabditis elegans, a metazoan in which established and emerging genetic technologies facilitate the study of developmental and physiological regulation in vivo. In this nematode, unbiased genetic screens have revealed critical roles for Mediator components in core developmental pathways such as epidermal growth factor (EGF) and Wnt/β-catenin signaling. More recently, important roles for C. elegans Mediator subunits have emerged in the regulation of lipid metabolism and of systemic stress responses, engaging conserved transcription factors such as nuclear hormone receptors (NHRs). We emphasize instances where similar functions for individual Mediator subunits exist in mammals, highlighting parallels between Mediator subunit action in nematode development and in human cancer biology. We also discuss a parallel between the association of the Mediator subunit MED12 with several human disorders and the role of its C. elegans ortholog mdt-12 as a regulatory hub that interacts with numerous signaling pathways. PMID:25634893

Pharmacological inhibition of fibroblast growth factor (FGF) receptor signaling ameliorates FGF23-mediated hypophosphatemic rickets.

PubMed

Wöhrle, Simon; Henninger, Christine; Bonny, Olivier; Thuery, Anne; Beluch, Noemie; Hynes, Nancy E; Guagnano, Vito; Sellers, William R; Hofmann, Francesco; Kneissel, Michaela; Graus Porta, Diana

2013-04-01

Fibroblast growth factor 23 (FGF23) is a circulating factor secreted by osteocytes that is essential for phosphate homeostasis. In kidney proximal tubular cells FGF23 inhibits phosphate reabsorption and leads to decreased synthesis and enhanced catabolism of 1,25-dihydroxyvitamin D3 (1,25[OH]2 D3 ). Excess levels of FGF23 cause renal phosphate wasting and suppression of circulating 1,25(OH)2 D3 levels and are associated with several hereditary hypophosphatemic disorders with skeletal abnormalities, including X-linked hypophosphatemic rickets (XLH) and autosomal recessive hypophosphatemic rickets (ARHR). Currently, therapeutic approaches to these diseases are limited to treatment with activated vitamin D analogues and phosphate supplementation, often merely resulting in partial correction of the skeletal aberrations. In this study, we evaluate the use of FGFR inhibitors for the treatment of FGF23-mediated hypophosphatemic disorders using NVP-BGJ398, a novel selective, pan-specific FGFR inhibitor currently in Phase I clinical trials for cancer therapy. In two different hypophosphatemic mouse models, Hyp and Dmp1-null mice, resembling the human diseases XLH and ARHR, we find that pharmacological inhibition of FGFRs efficiently abrogates aberrant FGF23 signaling and normalizes the hypophosphatemic and hypocalcemic conditions of these mice. Correspondingly, long-term FGFR inhibition in Hyp mice leads to enhanced bone growth, increased mineralization, and reorganization of the disturbed growth plate structure. We therefore propose NVP-BGJ398 treatment as a novel approach for the therapy of FGF23-mediated hypophosphatemic diseases. Copyright © 2013 American Society for Bone and Mineral Research.

Regulatory system reform of occupational health and safety in China.

PubMed

Wu, Fenghong; Chi, Yan

2015-01-01

With the explosive economic growth and social development, China's regulatory system of occupational health and safety now faces more and more challenges. This article reviews the history of regulatory system of occupational health and safety in China, as well as the current reform of this regulatory system in the country. Comprehensive, a range of laws, regulations and standards that promulgated by Chinese government, duties and responsibilities of the regulatory departments are described. Problems of current regulatory system, the ongoing adjustments and changes for modifying and improving regulatory system are discussed. The aim of reform and the incentives to drive forward more health and safety conditions in workplaces are also outlined.

Blocking IL-2 Signal In Vivo with an IL-2 Antagonist Reduces Tumor Growth through the Control of Regulatory T Cells.

PubMed

Carmenate, Tania; Ortíz, Yaquelín; Enamorado, Michel; García-Martínez, Karina; Avellanet, Janet; Moreno, Ernesto; Graça, Luis; León, Kalet

2018-05-15

IL-2 is critical for peripheral tolerance mediated by regulatory T (Treg) cells, which represent an obstacle for effective cancer immunotherapy. Although IL-2 is important for effector (E) T cell function, it has been hypothesized that therapies blocking IL-2 signals weaken Treg cell activity, promoting immune responses. This hypothesis has been partially tested using anti-IL-2 or anti-IL-2R Abs with antitumor effects that cannot be exclusively attributed to lack of IL-2 signaling in vivo. In this work, we pursued an alternative strategy to block IL-2 signaling in vivo, taking advantage of the trimeric structure of the IL-2R. We designed an IL-2 mutant that conserves the capacity to bind to the αβ-chains of the IL-2R but not to the γ c -chain, thus having a reduced signaling capacity. We show our IL-2 mutein inhibits IL-2 Treg cell-dependent differentiation and expansion. Moreover, treatment with IL-2 mutein reduces Treg cell numbers and impairs tumor growth in mice. A mathematical model was used to better understand the effect of the mutein on Treg and E T cells, suggesting suitable strategies to improve its design. Our results show that it is enough to transiently inhibit IL-2 signaling to bias E and Treg cell balance in vivo toward immunity. Copyright © 2018 by The American Association of Immunologists, Inc.

Involvement of hexokinase1 in plant growth promotion as mediated by Burkholderia phytofirmans.

PubMed

Park, Jae Min; Lazarovits, George

2014-06-01

Potato plantlets inoculated with strain PsJN of the bacterium Burkholderia phytofirmans exhibit consistent and significant increases in plant growth under in vitro conditions, when compared with uninoculated plants. The greatest influence on the degree and type of growth enhancement that develops has been shown to be mediated by the sugar concentration in the agar media. Bacterial growth promotion has been suggested in other studies to be regulated by the sugar sensor enzyme hexokinase1, the role of which is activation of glucose phosphorylation. In this present study, we examined the co-relationship between root and stem development in potato plants treated with PsJN and the activity of hexokinase1. Plants grown in the presence of 1.5% and 3% sucrose showed increased levels of hexokinase1 activity only in the roots of inoculated plants, suggesting that the increased enzyme levels may be associated with root growth. Analysis for mRNA using reverse transcriptase did not reveal any significant differences in transcription levels of the gene between inoculated and uninoculated plants. When PsJN-inoculated plants were grown in 1.5% and 3% concentrations of glucose and fructose, stem height and mass, leaf number, root mass, and overall biomass increased. No growth promotion occurred when PsJN-inoculated plants were grown in 3% maltose. Subsequently, a hexokinase1 activity assay showed that PsJN-induced growth of potato plants was found to only occur when plants were grown in the presence of sugars that are recognized by the plant hexokinase1. The results suggest that PsJN may enhance sugar uptake in plants by direct or indirect stimulation of hexokinase1 activity in roots and this results in enhanced overall plant growth.

Primary Inhibition of Hypocotyl Growth and Phototropism Depend Differently on Phototropin-Mediated Increases in Cytoplasmic Calcium Induced by Blue Light1

PubMed Central

Folta, Kevin M.; Lieg, Erin J.; Durham, Tessa; Spalding, Edgar P.

2003-01-01

The phototropin photoreceptors transduce blue-light signals into several physiological and developmental responses in plants. A transient rise in cytoplasmic calcium (Ca2+) that begins within seconds of phototropin 1 (phot1) excitation is believed to be an important element in the transduction pathways leading to one or more of the phot1-dependent responses. The goal of the present work was to determine whether the Ca2+ response was necessary for (a) the inhibition of hypocotyl elongation that develops within minutes of the irradiation, and (b) hypocotyl phototropism (curved growth of the stem in response to asymmetric illumination). After determining that pulses of light delivering photon fluences of between 1 and 1,000 μmol m-2 induced growth inhibition mediated by phot1 without significant interference from other photosensory pathways, the effect of blocking the Ca2+ rise was assessed. Treatment of seedlings with a Ca2+ chelator prevented the rise in cytoplasmic Ca2+ and prevented phot1-mediated growth inhibition. However, the same chelator treatment did not impair phot1-mediated phototropism. Thus, it appears that the early, transient rise in cytoplasmic Ca2+ is an important intermediary process in at least one but not all phot1-signaling pathways. PMID:14645723

Specific recruitment of regulatory T cells in ovarian carcinoma fosters immune privilege and predicts reduced survival.

PubMed

Curiel, Tyler J; Coukos, George; Zou, Linhua; Alvarez, Xavier; Cheng, Pui; Mottram, Peter; Evdemon-Hogan, Melina; Conejo-Garcia, Jose R; Zhang, Lin; Burow, Matthew; Zhu, Yun; Wei, Shuang; Kryczek, Ilona; Daniel, Ben; Gordon, Alan; Myers, Leann; Lackner, Andrew; Disis, Mary L; Knutson, Keith L; Chen, Lieping; Zou, Weiping

2004-09-01

Regulatory T (T(reg)) cells mediate homeostatic peripheral tolerance by suppressing autoreactive T cells. Failure of host antitumor immunity may be caused by exaggerated suppression of tumor-associated antigen-reactive lymphocytes mediated by T(reg) cells; however, definitive evidence that T(reg) cells have an immunopathological role in human cancer is lacking. Here we show, in detailed studies of CD4(+)CD25(+)FOXP3(+) T(reg) cells in 104 individuals affected with ovarian carcinoma, that human tumor T(reg) cells suppress tumor-specific T cell immunity and contribute to growth of human tumors in vivo. We also show that tumor T(reg) cells are associated with a high death hazard and reduced survival. Human T(reg) cells preferentially move to and accumulate in tumors and ascites, but rarely enter draining lymph nodes in later cancer stages. Tumor cells and microenvironmental macrophages produce the chemokine CCL22, which mediates trafficking of T(reg) cells to the tumor. This specific recruitment of T(reg) cells represents a mechanism by which tumors may foster immune privilege. Thus, blocking T(reg) cell migration or function may help to defeat human cancer.

Dynamics of the job search process: developing and testing a mediated moderation model.

PubMed

Sun, Shuhua; Song, Zhaoli; Lim, Vivien K G

2013-09-01

Taking a self-regulatory perspective, we develop a mediated moderation model explaining how within-person changes in job search efficacy and chronic regulatory focus interactively affect the number of job interview offers and whether job search effort mediates the cross-level interactive effects. A sample of 184 graduating college students provided monthly reports of their job search activities over a period of 8 months. Findings supported the hypothesized relationships. Specifically, at the within-person level, job search efficacy was positively related with the number of interview offers for job seekers with strong prevention focus and negatively related with the number of interview offers for job seekers with strong promotion focus. Results show that job search effort mediated the moderated relationships. Findings enhance understandings of the complex self-regulatory processes underlying job search. PsycINFO Database Record (c) 2013 APA, all rights reserved

Metalloproteinase-dependent transforming growth factor-alpha release mediates neurotensin-stimulated MAP kinase activation in human colonic epithelial cells.

PubMed

Zhao, Dezheng; Zhan, Yanai; Koon, Hon Wai; Zeng, Huiyan; Keates, Sarah; Moyer, Mary P; Pothoulakis, Charalabos

2004-10-15

Expression of the neuropeptide neurotensin (NT) and its high affinity receptor (NTR1) is increased during the course of Clostridium difficile toxin A-induced acute colitis, and NTR1 antagonism attenuates the severity of toxin A-induced inflammation. We recently demonstrated in non-transformed human colonic epithelial NCM460 cells that NT treatment caused activation of a Ras-mediated MAP kinase pathway that significantly contributes to NT-induced interleukin-8 (IL-8) secretion. Here we used NCM460 cells, which normally express low levels of NTR1, and NCM460 cells stably transfected with NTR1 to identify the upstream signaling molecules involved in NT-NTR1-mediated MAP kinase activation. We found that inhibition of the epidermal growth factor receptor (EGFR) by either an EGFR neutralizing antibody or by its specific inhibitor AG1478 (0.2 microm) blocked NT-induced MAP kinase activation. Moreover, NT stimulated tyrosine phosphorylation of the EGFR, and pretreatment with a broad spectrum metalloproteinase inhibitor batimastat reduced NT-induced MAP kinase activation. Using neutralizing antibodies against the EGFR ligands EGF, heparin-binding-EGF, transforming growth factor-alpha (TGFalpha), or amphiregulin we have shown that only the anti-TGFalpha antibody significantly decreases NT-induced phosphorylation of EGFR and MAP kinases. Furthermore, inhibition of the EGF receptor by AG1478 significantly reduced NT-induced IL-8 promoter activity and IL-8 secretion. This is the first report demonstrating that NT binding to NTR1 transactivates the EGFR and that this response is linked to NT-mediated proinflammatory signaling. Our findings indicate that matrix metalloproteinase-mediated release of TGFalpha and subsequent EGFR transactivation triggers a NT-mediated MAP kinase pathway that leads to IL-8 gene expression in human colonic epithelial cells.

CNPY2 inhibits MYLIP-mediated AR protein degradation in prostate cancer cells

PubMed Central

Ito, Saya; Ueno, Akihisa; Ueda, Takashi; Nakagawa, Hideo; Taniguchi, Hidefumi; Kayukawa, Naruhiro; Fujihara-Iwata, Atsuko; Hongo, Fumiya; Okihara, Koji; Ukimura, Osamu

2018-01-01

The androgen receptor (AR) is a ligand-dependent transcription factor that promotes prostate cancer (PC) cell growth through control of target gene expression. This report suggests that Canopy FGF signaling regulator 2 (CNPY2) controls AR protein levels in PC cells. We found that AR was ubiquitinated by an E3 ubiquitin ligase, myosin regulatory light chain interacting protein (MYLIP) and then degraded through the ubiquitin-proteasome pathway. CNPY2 decreased the ubiquitination activity of MYLIP by inhibition of interaction between MYLIP and UBE2D1, an E2 ubiquitin ligase. CNPY2 up-regulated gene expression of AR target genes such as KLK3 gene which encodes the prostate specific antigen (PSA) and promoted cell growth of PC cells. The cell growth inhibition by CNPY2 knockdown was rescued by AR overexpression. Furthermore, positive correlation of expression levels between CNPY2 and AR/AR target genes was observed in tissue samples from human prostate cancer patients. Together, these results suggested that CNPY2 promoted cell growth of PC cells by inhibition of AR protein degradation through MYLIP-mediated AR ubiquitination. PMID:29707137

Mss11p Is a Central Element of the Regulatory Network That Controls FLO11 Expression and Invasive Growth in Saccharomyces cerevisiae

PubMed Central

van Dyk, Dewald; Pretorius, Isak S.; Bauer, Florian F.

2005-01-01

The invasive and filamentous growth forms of Saccharomyces cerevisiae are adaptations to specific environmental conditions, under particular conditions of limited nutrient availability. Both growth forms are dependent on the expression of the FLO11 gene, which encodes a cell-wall-associated glycoprotein involved in cellular adhesion. A complex regulatory network consisting of signaling pathways and transcription factors has been associated with the regulation of FLO11. Mss11p has been identified as a transcriptional activator of this gene, and here we present an extensive genetic analysis to identify functional relationships between Mss11p and other FLO11 regulators. The data show that Mss11p is absolutely required for the activation of FLO11 by most proteins that have previously been shown to affect FLO11 expression, including the signaling proteins Ras2p, Kss1p, and Tpk2p, the activators Tec1p, Flo8p, and Phd1p, and the repressors Nrg1p, Nrg2p, Sok2p, and Sfl1p. The genetic evidence furthermore suggests that Mss11p activity is not dependent on the presence of any of the above-mentioned factors and that the protein also regulates other genes involved in cellular adhesion phenotypes. Taken together, the data strongly suggest a central role for Mss11p in the regulatory network controlling FLO11 expression, invasive growth, and pseudohyphal differentiation. PMID:15466424

A Systems' Biology Approach to Study MicroRNA-Mediated Gene Regulatory Networks

PubMed Central

Kunz, Manfred; Vera, Julio; Wolkenhauer, Olaf

2013-01-01

MicroRNAs (miRNAs) are potent effectors in gene regulatory networks where aberrant miRNA expression can contribute to human diseases such as cancer. For a better understanding of the regulatory role of miRNAs in coordinating gene expression, we here present a systems biology approach combining data-driven modeling and model-driven experiments. Such an approach is characterized by an iterative process, including biological data acquisition and integration, network construction, mathematical modeling and experimental validation. To demonstrate the application of this approach, we adopt it to investigate mechanisms of collective repression on p21 by multiple miRNAs. We first construct a p21 regulatory network based on data from the literature and further expand it using algorithms that predict molecular interactions. Based on the network structure, a detailed mechanistic model is established and its parameter values are determined using data. Finally, the calibrated model is used to study the effect of different miRNA expression profiles and cooperative target regulation on p21 expression levels in different biological contexts. PMID:24350286

Co-Targeting Prostate Cancer Epithelium and Bone Stroma by Human Osteonectin-Promoter-Mediated Suicide Gene Therapy Effectively Inhibits Androgen-Independent Prostate Cancer Growth.

PubMed

Sung, Shian-Ying; Chang, Junn-Liang; Chen, Kuan-Chou; Yeh, Shauh-Der; Liu, Yun-Ru; Su, Yen-Hao; Hsueh, Chia-Yen; Chung, Leland W K; Hsieh, Chia-Ling

2016-01-01

Stromal-epithelial interaction has been shown to promote local tumor growth and distant metastasis. We sought to create a promising gene therapy approach that co-targets cancer and its supporting stromal cells for combating castration-resistant prostate tumors. Herein, we demonstrated that human osteonectin is overexpressed in the prostate cancer epithelium and tumor stroma in comparison with their normal counterpart. We designed a novel human osteonectin promoter (hON-522E) containing positive transcriptional regulatory elements identified in both the promoter and exon 1 region of the human osteonectin gene. In vitro reporter assays revealed that the hON-522E promoter is highly active in androgen receptor negative and metastatic prostate cancer and bone stromal cells compared to androgen receptor-positive prostate cancer cells. Moreover, in vivo prostate-tumor-promoting activity of the hON-522E promoter was confirmed by intravenous administration of an adenoviral vector containing the hON-522E promoter-driven luciferase gene (Ad-522E-Luc) into mice bearing orthotopic human prostate tumor xenografts. In addition, an adenoviral vector with the hON-522E-promoter-driven herpes simplex virus thymidine kinase gene (Ad-522E-TK) was highly effective against the growth of androgen-independent human prostate cancer PC3M and bone stromal cell line in vitro and in pre-established PC3M tumors in vivo upon addition of the prodrug ganciclovir. Because of the heterogeneity of human prostate tumors, hON-522E promoter-mediated gene therapy has the potential for the treatment of hormone refractory and bone metastatic prostate cancers.

Regulatory system reform of occupational health and safety in China

PubMed Central

WU, Fenghong; CHI, Yan

2015-01-01

With the explosive economic growth and social development, China’s regulatory system of occupational health and safety now faces more and more challenges. This article reviews the history of regulatory system of occupational health and safety in China, as well as the current reform of this regulatory system in the country. Comprehensive, a range of laws, regulations and standards that promulgated by Chinese government, duties and responsibilities of the regulatory departments are described. Problems of current regulatory system, the ongoing adjustments and changes for modifying and improving regulatory system are discussed. The aim of reform and the incentives to drive forward more health and safety conditions in workplaces are also outlined. PMID:25843565

Expression profiles and associations of muscle regulatory factor (MRF) genes with growth traits in Tibetan chickens.

PubMed

Zhang, R; Li, R; Zhi, L; Xu, Y; Lin, Y; Chen, L

2018-02-01

1. Muscle regulatory factors (MRFs), including Myf5, Myf6 (MRF4/herculin), MyoD and MyoG (myogenin), play pivotal roles in muscle growth and development. Therefore, they are considered as candidate genes for meat production traits in livestock and poultry. 2. The objective of this study was to investigate the expression profiles of these genes in skeletal muscles (breast muscle and thigh muscle) at 5 developmental stages (0, 81, 119, 154 and 210 d old) of Tibetan chickens. Relationships between expressions of these genes and growth and carcass traits in these chickens were also estimated. 3. The expression profiles showed that in the breast muscle of both genders the mRNA levels of MRF genes were highest on the day of hatching, then declined significantly from d 0 to d 81, and fluctuated in a certain range from d 81 to d 210. However, the expression of Myf5, Myf6 and MyoG reached peaks in the thigh muscle in 118-d-old females and for MyoD in 154-d-old females, whereas the mRNA amounts of MRF genes in the male thigh muscle were in a narrow range from d 0 to d 210. 4. Correlation analysis suggested that gender had an influence on the relationships of MRF gene expression with growth traits. The RNA levels of MyoD, Myf5 genes in male breast muscle were positively related with several growth traits of Tibetan chickens (P < 0.05). No correlation was found between expressions of MRF genes and carcass traits of the chickens. 5. These results will provide a base for functional studies of MRF genes on growth and development of Tibetan chickens, as well as selective breeding and resource exploration.

Identification of Regulatory T Cells in Tolerated Allografts

PubMed Central

Graca, Luis; Cobbold, Stephen P.; Waldmann, Herman

2002-01-01

Induction of transplantation tolerance with certain therapeutic nondepleting monoclonal antibodies can lead to a robust state of peripheral “dominant” tolerance. Regulatory CD4+ T cells, which mediate this form of “dominant” tolerance, can be isolated from spleens of tolerant animals. To determine whether there were any extra-lymphoid sites that might harbor regulatory T cells we sought their presence in tolerated skin allografts and in normal skin. When tolerated skin grafts are retransplanted onto T cell–depleted hosts, graft-infiltrating T cells exit the graft and recolonize the new host. These colonizing T cells can be shown to contain members with regulatory function, as they can prevent nontolerant lymphocytes from rejecting fresh skin allografts, without hindrance of rejection of third party skin. Our results suggest that T cell suppression of graft rejection is an active process that operates beyond secondary lymphoid tissue, and involves the persistent presence of regulatory T cells at the site of the tolerated transplant. PMID:12070291

The Mediator complex of Caenorhabditis elegans: insights into the developmental and physiological roles of a conserved transcriptional coregulator.

PubMed

Grants, Jennifer M; Goh, Grace Y S; Taubert, Stefan

2015-02-27

The Mediator multiprotein complex ('Mediator') is an important transcriptional coregulator that is evolutionarily conserved throughout eukaryotes. Although some Mediator subunits are essential for the transcription of all protein-coding genes, others influence the expression of only subsets of genes and participate selectively in cellular signaling pathways. Here, we review the current knowledge of Mediator subunit function in the nematode Caenorhabditis elegans, a metazoan in which established and emerging genetic technologies facilitate the study of developmental and physiological regulation in vivo. In this nematode, unbiased genetic screens have revealed critical roles for Mediator components in core developmental pathways such as epidermal growth factor (EGF) and Wnt/β-catenin signaling. More recently, important roles for C. elegans Mediator subunits have emerged in the regulation of lipid metabolism and of systemic stress responses, engaging conserved transcription factors such as nuclear hormone receptors (NHRs). We emphasize instances where similar functions for individual Mediator subunits exist in mammals, highlighting parallels between Mediator subunit action in nematode development and in human cancer biology. We also discuss a parallel between the association of the Mediator subunit MED12 with several human disorders and the role of its C. elegans ortholog mdt-12 as a regulatory hub that interacts with numerous signaling pathways. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Positive and Negative Regulatory Mechanisms for Fine-Tuning Cellularity and Functions of Medullary Thymic Epithelial Cells.

PubMed

Akiyama, Taishin; Tateishi, Ryosuke; Akiyama, Nobuko; Yoshinaga, Riko; Kobayashi, Tetsuya J

2015-01-01

Self-tolerant T cells and regulatory T cells develop in the thymus. A wide variety of cell-cell interactions in the thymus is required for the differentiation, proliferation, and repertoire selection of T cells. Various secreted and cell surface molecules expressed in thymic epithelial cells (TECs) mediate these processes. Moreover, cytokines expressed by cells of hematopoietic origin regulate the cellularity of TECs. Tumor necrosis factor (TNF) family RANK ligand, lymphotoxin, and CD40 ligand, expressed in T cells and innate lymphoid cells (ILCs), promote the differentiation and proliferation of medullary TECs (mTECs) that play critical roles in the induction of immune tolerance. A recent study suggests that interleukin-22 (IL-22) produced by ILCs promotes regeneration of TECs after irradiation. Intriguingly, tumor growth factor-β and osteoprotegerin limit cellularity of mTECs, thereby attenuating regulatory T cell generation. We will review recent insights into the molecular basis for cell-cell interactions regulating differentiation and proliferation of mTECs and also discuss about a perspective on use of mathematical models for understanding this complicated system.

Coordinate regulation of estrogen-mediated fibronectin matrix assembly and epidermal growth factor receptor transactivation by the G protein-coupled receptor, GPR30.

PubMed

Quinn, Jeffrey A; Graeber, C Thomas; Frackelton, A Raymond; Kim, Minsoo; Schwarzbauer, Jean E; Filardo, Edward J

2009-07-01

Estrogen promotes changes in cytoskeletal architecture not easily attributed to the biological action of estrogen receptors, ERalpha and ERbeta. The Gs protein-coupled transmembrane receptor, GPR30, is linked to specific estrogen binding and rapid estrogen-mediated release of heparin-bound epidermal growth factor. Using marker rescue and dominant interfering mutant strategies, we show that estrogen action via GPR30 promotes fibronectin (FN) matrix assembly by human breast cancer cells. Stimulation with 17beta-estradiol or the ER antagonist, ICI 182, 780, results in the recruitment of FN-engaged integrin alpha5beta1 conformers to fibrillar adhesions and the synthesis of FN fibrils. Concurrent with this cellular response, GPR30 promotes the formation of Src-dependent, Shc-integrin alpha5beta1 complexes. Function-blocking antibodies directed against integrin alpha5beta1 or soluble Arg-Gly-Asp peptide fragments derived from FN specifically inhibited GPR30-mediated epidermal growth factor receptor transactivation. Estrogen-mediated FN matrix assembly and epidermal growth factor receptor transactivation were similarly disrupted in integrin beta1-deficient GE11 cells, whereas reintroduction of integrin beta1 into GE11 cells restored these responses. Mutant Shc (317Y/F) blocked GPR30-induced FN matrix assembly and tyrosyl phosphorylation of erbB1. Interestingly, relative to recombinant wild-type Shc, 317Y/F Shc was more readily retained in GPR30-induced integrin alpha5beta1 complexes, yet this mutant did not prevent endogenous Shc-integrin alpha5beta1 complex formation. Our results suggest that GPR30 coordinates estrogen-mediated FN matrix assembly and growth factor release in human breast cancer cells via a Shc-dependent signaling mechanism that activates integrin alpha5beta1.

How can we make plants grow faster? A source–sink perspective on growth rate

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, Angela C.; Rogers, Alistair; Rees, Mark

Growth is a major component of fitness in all organisms, an important mediator of competitive interactions in plant communities, and a central determinant of yield in crops. Understanding what limits plant growth is therefore of fundamental importance to plant evolution, ecology, and crop science, but each discipline views the process from a different perspective. This review highlights the importance of source–sink interactions as determinants of growth. The evidence for source- and sink-limitation of growth, and the ways in which regulatory molecular feedback systems act to maintain an appropriate source:sink balance, are first discussed. Evidence clearly shows that future increases inmore » crop productivity depend crucially on a quantitative understanding of the extent to which sources or sinks limit growth, and how this changes during development. In addition, to identify bottlenecks limiting growth and yield, a holistic view of growth is required at the whole-plant scale, incorporating mechanistic interactions between physiology, resource allocation, and plant development. Such a holistic perspective on source–sink interactions will allow the development of a more integrated, whole-system level understanding of growth, with benefits across multiple disciplines.« less

How can we make plants grow faster? A source–sink perspective on growth rate

DOE PAGES

White, Angela C.; Rogers, Alistair; Rees, Mark; ...

2015-10-14

Growth is a major component of fitness in all organisms, an important mediator of competitive interactions in plant communities, and a central determinant of yield in crops. Understanding what limits plant growth is therefore of fundamental importance to plant evolution, ecology, and crop science, but each discipline views the process from a different perspective. This review highlights the importance of source–sink interactions as determinants of growth. The evidence for source- and sink-limitation of growth, and the ways in which regulatory molecular feedback systems act to maintain an appropriate source:sink balance, are first discussed. Evidence clearly shows that future increases inmore » crop productivity depend crucially on a quantitative understanding of the extent to which sources or sinks limit growth, and how this changes during development. In addition, to identify bottlenecks limiting growth and yield, a holistic view of growth is required at the whole-plant scale, incorporating mechanistic interactions between physiology, resource allocation, and plant development. Such a holistic perspective on source–sink interactions will allow the development of a more integrated, whole-system level understanding of growth, with benefits across multiple disciplines.« less

Additive effects of inflammation and stress reaction on Toll-like receptor 4-mediated growth of endometriotic stromal cells.

PubMed

Khan, Khaleque Newaz; Kitajima, Michio; Inoue, Tsuneo; Tateishi, Seiko; Fujishita, Akira; Nakashima, Masahiro; Masuzaki, Hideaki

2013-10-01

Is there any combined effect between inflammation and stress reaction on Toll-like receptor 4 (TLR4)-mediated growth of endometriotic cells? A combined effect of local inflammation and stress reaction in the pelvic environment may be involved in TLR4-mediated growth of endometriotic stromal cells. In endometriosis, higher endotoxin levels in the menstrual fluid (MF) and peritoneal fluid (PF) and higher tissue concentrations of human heat shock protein 70 (HSP70) in the eutopic and ectopic endometria promote TLR4-mediated growth of endometriotic cells. This is a case-controlled research study with prospective collection and retrospective evaluation of sera, MF, PF and endometrial tissues from 43 women with and 20 women without endometriosis. PF was collected from 43 women with endometriosis and 20 control women during laparoscopy. Sera and endometrial biopsy specimens were collected from a proportion of these women. MF was collected from a separate population of 20 women with endometriosis and 15 control women. HSP70 concentrations in sera, MF, PF and in culture media were measured by ELISA. Gene expression of HSP70 by endometrial cells in response to lipopolysaccharide (LPS) was examined by qRT-PCR. The individual and combined effects of LPS and HSP70 on the secretion of interleukin-6 (IL-6) and tumor necrosis factor α (TNFα) by PF-derived macrophages (M[Symbol: see text]) were examined by ELISA, while their effects on endometrial cell proliferation were examined by bromodeoxyuridine and [(3)H]-thymidine incorporation assay. Concentrations of HSP70 were maximal in MF, intermediate in PF and the lowest in sera. In MF and PF, HSP70 levels were higher in women with endometriosis than in controls. LPS stimulated gene expression and secretion of HSP70 by eutopic endometrial stromal cells (ESCs) and this effect was abrogated after pretreatment of cells with an anti-TLR4 antibody. This effect was significantly higher for ESCs derived from women with endometriosis than

The p85α regulatory subunit of PI3K mediates cAMP-PKA and retinoic acid biological effects on MCF7 cell growth and migration.

PubMed

Donini, Caterina F; Di Zazzo, Erika; Zuchegna, Candida; Di Domenico, Marina; D'Inzeo, Sonia; Nicolussi, Arianna; Avvedimento, Enrico V; Coppa, Anna; Porcellini, Antonio

2012-05-01

Phosphoinositide-3-OH kinase (PI3K) signalling regulates various cellular processes, including cell survival, growth, proliferation and motility, and is among the most frequently mutated pathways in cancer. Although the involvement of p85αPI3K SH2 domain in signal transduction has been extensively studied, the function of the SH3 domain at the N-terminus remains elusive. A serine (at codon 83) adjacent to the N-terminal SH3 domain in the PI3K regulatory subunit p85αPI3K that is phosphorylated by protein kinase A (PKA) in vivo and in vitro has been identified. Virtually all receptors binding p85αPI3K can cooperate with cAMP-PKA signals via phosphorylation of p85αPI3KSer83. To analyse the role of p85αPI3KSer83 in retinoic acid (RA) and cAMP signalling, in MCF7 cells, we used p85αPI3K mutated forms, in which Ser83 has been substituted with alanine (p85A) to prevent phosphorylation or with aspartic acid (p85D) to mimic the phosphorylated residue. We demonstrated that p85αPI3KSer83 is crucial for the synergistic enhancement of RARα/p85αPI3K binding induced by cAMP/RA co-treatment in MCF7 cells. Growth curves, colorimetric MTT assay and cell cycle analysis demonstrated that phosphorylation of p85αPI3KSer83 plays an important role in the control of MCF7 cell proliferation and in RA-induced inhibition of proliferation. Wound healing and transwell experiments demonstrated that p85αPI3KSer83 was also essential both for the control of migratory behaviour and for the reduction of motility induced by RA. This study points to p85αPI3KSer83 as the physical link between different pathways (cAMP-PKA, RA and FAK), and as an important regulator of MCF7 cell proliferation and migration.

A mathematical model for IL-6-mediated, stem cell driven tumor growth and targeted treatment

PubMed Central

Nör, Jacques Eduardo

2018-01-01

Targeting key regulators of the cancer stem cell phenotype to overcome their critical influence on tumor growth is a promising new strategy for cancer treatment. Here we present a modeling framework that operates at both the cellular and molecular levels, for investigating IL-6 mediated, cancer stem cell driven tumor growth and targeted treatment with anti-IL6 antibodies. Our immediate goal is to quantify the influence of IL-6 on cancer stem cell self-renewal and survival, and to characterize the subsequent impact on tumor growth dynamics. By including the molecular details of IL-6 binding, we are able to quantify the temporal changes in fractional occupancies of bound receptors and their influence on tumor volume. There is a strong correlation between the model output and experimental data for primary tumor xenografts. We also used the model to predict tumor response to administration of the humanized IL-6R monoclonal antibody, tocilizumab (TCZ), and we found that as little as 1mg/kg of TCZ administered weekly for 7 weeks is sufficient to result in tumor reduction and a sustained deceleration of tumor growth. PMID:29351275

Interleukin-35 induces regulatory B cells that suppress autoimmune disease.

PubMed

Wang, Ren-Xi; Yu, Cheng-Rong; Dambuza, Ivy M; Mahdi, Rashid M; Dolinska, Monika B; Sergeev, Yuri V; Wingfield, Paul T; Kim, Sung-Hye; Egwuagu, Charles E

2014-06-01

Interleukin-10 (IL-10)-producing regulatory B (Breg) cells suppress autoimmune disease, and increased numbers of Breg cells prevent host defense to infection and promote tumor growth and metastasis by converting resting CD4(+) T cells to regulatory T (Treg) cells. The mechanisms mediating the induction and development of Breg cells remain unclear. Here we show that IL-35 induces Breg cells and promotes their conversion to a Breg subset that produces IL-35 as well as IL-10. Treatment of mice with IL-35 conferred protection from experimental autoimmune uveitis (EAU), and mice lacking IL-35 (p35 knockout (KO) mice) or defective in IL-35 signaling (IL-12Rβ2 KO mice) produced less Breg cells endogenously or after treatment with IL-35 and developed severe uveitis. Adoptive transfer of Breg cells induced by recombinant IL-35 suppressed EAU when transferred to mice with established disease, inhibiting pathogenic T helper type 17 (TH17) and TH1 cells while promoting Treg cell expansion. In B cells, IL-35 activates STAT1 and STAT3 through the IL-35 receptor comprising the IL-12Rβ2 and IL-27Rα subunits. As IL-35 also induced the conversion of human B cells into Breg cells, these findings suggest that IL-35 may be used to induce autologous Breg and IL-35(+) Breg cells and treat autoimmune and inflammatory disease.

Strong Surface Diffusion Mediated Glancing-Angle Deposition: Growth, Recrystallization and Reorientation of Tin Nanorods

NASA Astrophysics Data System (ADS)

Wang, Huan-Hua; Shi, Yi-Jian; William, Chu; Yigal, Blum

2008-01-01

Different from usual glancing-angle deposition where low surface diffusion is necessary to form nanorods, strong surface diffusion mediated glancing-angle deposition is exemplified by growing tin nanorod films on both silicon and glass substrates simultaneously via thermal evaporation. During growth, the nanorods were simultaneously baked by the high-temperature evaporator, and therefore re-crystallized into single crystals in consequence of strong surface diffusion. The monocrystalline tin nanorods have a preferred orientation perpendicular to the substrate surface, which is quite different from the usual uniformly oblique nanorods without recrystallization.

Basic Fibroblast Growth Factor Activates Serum Response Factor Gene Expression by Multiple Distinct Signaling Mechanisms

PubMed Central

Spencer, Jeffrey A.; Major, Michael L.; Misra, Ravi P.

1999-01-01

Serum response factor (SRF) plays a central role in the transcriptional response of mammalian cells to a variety of extracellular signals. It is a key regulator of many cellular early response genes which are believed to be involved in cell growth and differentiation. The mechanism by which SRF activates transcription in response to mitogenic agents has been extensively studied; however, significantly less is known about regulation of the SRF gene itself. Previously, we identified distinct regulatory elements in the SRF promoter that play a role in activation, including a consensus ETS domain binding site, a consensus overlapping Sp/Egr-1 binding site, and two SRF binding sites. We further showed that serum induces SRF by a mechanism that requires an intact SRF binding site, also termed a CArG box. In the present study we demonstrate that in response to stimulation of cells by a purified growth factor, basic fibroblast growth factor (bFGF), the SRF promoter is upregulated by a complex pathway that involves at least two independent mechanisms: a CArG box-independent mechanism that is mediated by an ETS binding site, and a novel CArG box-dependent mechanism that requires both an Sp factor binding site and the CArG motifs for maximal stimulation. Our analysis indicates that the CArG/Sp element activation mechanism is mediated by distinct signaling pathways. The CArG box-dependent component is targeted by a Rho-mediated pathway, and the Sp binding site-dependent component is targeted by a Ras-mediated pathway. Both SRF and bFGF have been implicated in playing an important role in mediating cardiogenesis during development. The implications of our findings for SRF expression during development are discussed. PMID:10330138

Regulatory functions of SnRK1 in stress-responsive gene expression and in plant growth and development.

PubMed

Cho, Young-Hee; Hong, Jung-Woo; Kim, Eun-Chul; Yoo, Sang-Dong

2012-04-01

Sucrose-nonfermentation1-related protein kinase1 (SnRK1) is an evolutionarily conserved energy sensor protein that regulates gene expression in response to energy depletion in plants. Efforts to elucidate the functions and mechanisms of this protein kinase are hampered, however, by inherent growth defects of snrk1-null mutant plants. To overcome these limitations and study SnRK1 functions in vivo, we applied a method combining transient expression in leaf mesophyll protoplasts and stable expression in transgenic plants. We found that both rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana) SnRK1 activities critically influence stress-inducible gene expression and the induction of stress tolerance. Genetic, molecular, and chromatin immunoprecipitation analyses further revealed that the nuclear SnRK1 modulated target gene transcription in a submergence-dependent manner. From early seedling development through late senescence, SnRK1 activities appeared to modulate developmental processes in the plants. Our findings offer insight into the regulatory functions of plant SnRK1 in stress-responsive gene regulation and in plant growth and development throughout the life cycle.

Role of the retinoblastoma protein in cell cycle arrest mediated by a novel cell surface proliferation inhibitor

NASA Technical Reports Server (NTRS)

Enebo, D. J.; Fattaey, H. K.; Moos, P. J.; Johnson, T. C.; Spooner, B. S. (Principal Investigator)

1994-01-01

A novel cell regulatory sialoglycopeptide (CeReS-18), purified from the cell surface of bovine cerebral cortex cells has been shown to be a potent and reversible inhibitor of proliferation of a wide array of fibroblasts as well as epithelial-like cells and nontransformed and transformed cells. To investigate the possible mechanisms by which CeReS-18 exerts its inhibitory action, the effect of the inhibitor on the posttranslational regulation of the retinoblastoma susceptibility gene product (RB), a tumor suppressor gene, has been examined. It is shown that CeReS-18 mediated cell cycle arrest of both human diploid fibroblasts (HSBP) and mouse fibroblasts (Swiss 3T3) results in the maintenance of the RB protein in the hypophosphorylated state, consistent with a late G1 arrest site. Although their normal nontransformed counterparts are sensitive to cell cycle arrest mediated by CeReS-18, cell lines lacking a functional RB protein, through either genetic mutation or DNA tumor virus oncoprotein interaction, are less sensitive. The refractory nature of these cells is shown to be independent of specific surface receptors for the inhibitor, and another tumor suppressor gene (p53) does not appear to be involved in the CeReS-18 inhibition of cell proliferation. The requirement for a functional RB protein product, in order for CeReS-18 to mediate cell cycle arrest, is discussed in light of regulatory events associated with density-dependent growth inhibition.

Luteolin Inhibits Human Prostate Tumor Growth by Suppressing Vascular Endothelial Growth Factor Receptor 2-Mediated Angiogenesis

PubMed Central

Pratheeshkumar, Poyil; Son, Young-Ok; Budhraja, Amit; Wang, Xin; Ding, Songze; Wang, Lei; Hitron, Andrew; Lee, Jeong-Chae; Kim, Donghern; Divya, Sasidharan Padmaja; Chen, Gang; Zhang, Zhuo; Luo, Jia; Shi, Xianglin

2012-01-01

Angiogenesis, the formation of new blood vessels from pre-existing vascular beds, is essential for tumor growth, invasion, and metastasis. Luteolin is a common dietary flavonoid found in fruits and vegetables. We studied the antiangiogenic activity of luteolin using in vitro, ex vivo, and in vivo models. In vitro studies using rat aortic ring assay showed that luteolin at non-toxic concentrations significantly inhibited microvessel sprouting and proliferation, migration, invasion and tube formation of endothelial cells, which are key events in the process of angiogenesis. Luteolin also inhibited ex vivo angiogenesis as revealed by chicken egg chorioallantoic membrane assay (CAM) and matrigel plug assay. Gelatin zymographic analysis demonstrated the inhibitory effect of luteolin on the activation of matrix metalloproteinases MMP-2 and MMP-9. Western blot analysis showed that luteolin suppressed VEGF induced phosphorylation of VEGF receptor 2 and their downstream protein kinases AKT, ERK, mTOR, P70S6K, MMP-2, and MMP-9 in HUVECs. Proinflammatory cytokines such as IL-1β, IL-6, IL-8, and TNF-α level were significantly reduced by the treatment of luteolin in PC-3 cells. Luteolin (10 mg/kg/d) significantly reduced the volume and the weight of solid tumors in prostate xenograft mouse model, indicating that luteolin inhibited tumorigenesis by targeting angiogenesis. CD31 and CD34 immunohistochemical staining further revealed that the microvessel density could be remarkably suppressed by luteolin. Moreover, luteolin reduced cell viability and induced apoptosis in prostate cancer cells, which were correlated with the downregulation of AKT, ERK, mTOR, P70S6K, MMP-2, and MMP-9 expressions. Taken together, our findings demonstrate that luteolin inhibits human prostate tumor growth by suppressing vascular endothelial growth factor receptor 2-mediated angiogenesis. PMID:23300633

Donor CD4+ Foxp3+ regulatory T cells are necessary for posttransplantation cyclophosphamide-mediated protection against GVHD in mice

PubMed Central

Ganguly, Sudipto; Ross, Duncan B.; Panoskaltsis-Mortari, Angela; Kanakry, Christopher G.; Blazar, Bruce R.; Levy, Robert B.

2014-01-01

Posttransplantation cyclophosphamide (PTCy) is an effective prophylaxis against graft-versus-host disease (GVHD). However, it is unknown whether PTCy works singularly by eliminating alloreactive T cells via DNA alkylation or also by restoring the conventional (Tcon)/regulatory (Treg) T-cell balance. We studied the role of Tregs in PTCy-mediated GVHD prophylaxis in murine models of allogeneic blood or marrow transplantation (alloBMT). In 2 distinct MHC-matched alloBMT models, infusing Treg-depleted allografts abrogated the GVHD-prophylactic activity of PTCy. Using allografts in which Foxp3+ Tregs could be selectively depleted in vivo, either pre- or post-PTCy ablation of donor thymus–derived Tregs (tTregs) abolished PTCy protection against GVHD. PTCy treatment was associated with relative preservation of donor Tregs. Experiments using combinations of Foxp3– Tcons and Foxp3+ Tregs sorted from different Foxp3 reporter mice indicated that donor Treg persistence after PTCy treatment was predominantly caused by survival of functional tTregs that retained Treg-specific demethylation and also induction of peripherally derived Tregs. Finally, adoptive transfer of tTregs retrieved from PTCy-treated chimeras rescued PTCy-treated, Treg-depleted recipients from lethal GVHD. Our findings indicate that PTCy-mediated protection against GVHD is not singularly dependent on depletion of donor alloreactive T cells but also requires rapidly recovering donor Tregs to initiate and maintain alloimmune regulation. PMID:25139358

Intracellular mediators of transforming growth factor beta superfamily signaling localize to endosomes in chicken embryo and mouse lenses in vivo.

PubMed

Rajagopal, Ramya; Ishii, Shunsuke; Beebe, David C

2007-06-25

Endocytosis is a key regulator of growth factor signaling pathways. Recent studies showed that the localization to endosomes of intracellular mediators of growth factor signaling may be required for their function. Although there is substantial evidence linking endocytosis and growth factor signaling in cultured cells, there has been little study of the endosomal localization of signaling components in intact tissues or organs. Proteins that are downstream of the transforming growth factor-beta superfamily signaling pathway were found on endosomes in chicken embryo and postnatal mouse lenses, which depend on signaling by members of the TGFbeta superfamily for their normal development. Phosphorylated Smad1 (pSmad1), pSmad2, Smad4, Smad7, the transcriptional repressors c-Ski and TGIF and the adapter molecules Smad anchor for receptor activation (SARA) and C184M, localized to EEA-1- and Rab5-positive vesicles in chicken embryo and/or postnatal mouse lenses. pSmad1 and pSmad2 also localized to Rab7-positive late endosomes. Smad7 was found associated with endosomes, but not caveolae. Bmpr1a conditional knock-out lenses showed decreased nuclear and endosomal localization of pSmad1. Many of the effectors in this pathway were distributed differently in vivo from their reported distribution in cultured cells. Based on the findings reported here and data from other signaling systems, we suggest that the localization of activated intracellular mediators of the transforming growth factor-beta superfamily to endosomes is important for the regulation of growth factor signaling.

Genetic analysis of ectopic growth suppression during planar growth of integuments mediated by the Arabidopsis AGC protein kinase UNICORN.

PubMed

Enugutti, Balaji; Schneitz, Kay

2013-01-02

The coordination of growth within a tissue layer is of critical importance for tissue morphogenesis. For example, cells within the epidermis undergo stereotypic cell divisions that are oriented along the plane of the layer (planar growth), thereby propagating the layered epidermal structure. Little is known about the developmental control that regulates such planar growth in plants. Recent evidence suggested that the Arabidopsis AGC VIII protein kinase UNICORN (UCN) maintains planar growth by suppressing the formation of ectopic multicellular protrusions in several floral tissues including integuments. In the current model UCN controls this process during integument development by directly interacting with the ABERRANT TESTA SHAPE (ATS) protein, a member of the KANADI (KAN) family of transcription factors, thereby repressing its activity. Here we report on the further characterization of the UCN mechanism. Phenotypic analysis of flowers of ucn-1 plants impaired in floral homeotic gene activity revealed that any of the four floral whorls could produce organs carrying ucn-1 protrusions. The ectopic outgrowths of ucn integuments did not accumulate detectable signals of the auxin and cytokinin reporters DR5rev::GFP and ARR5::GUS, respectively. Furthermore, wild-type and ucn-1 seedlings showed similarly strong callus formation upon in vitro culture on callus-inducing medium. We also show that ovules of ucn-1 plants carrying the dominant ats allele sk21-D exhibited more pronounced protrusion formation. Finally ovules of ucn-1 ett-1 double mutants and ucn-1 ett-1 arf4-1 triple mutants displayed an additive phenotype. These data deepen the molecular insight into the UCN-mediated control of planar growth during integument development. The presented evidence indicates that UCN downstream signaling does not involve the control of auxin or cytokinin homeostasis. The results also reveal that UCN interacts with ATS independently of an ATS/ETT complex required for integument

Genetic analysis of ectopic growth suppression during planar growth of integuments mediated by the Arabidopsis AGC protein kinase UNICORN

PubMed Central

2013-01-01

Background The coordination of growth within a tissue layer is of critical importance for tissue morphogenesis. For example, cells within the epidermis undergo stereotypic cell divisions that are oriented along the plane of the layer (planar growth), thereby propagating the layered epidermal structure. Little is known about the developmental control that regulates such planar growth in plants. Recent evidence suggested that the Arabidopsis AGC VIII protein kinase UNICORN (UCN) maintains planar growth by suppressing the formation of ectopic multicellular protrusions in several floral tissues including integuments. In the current model UCN controls this process during integument development by directly interacting with the ABERRANT TESTA SHAPE (ATS) protein, a member of the KANADI (KAN) family of transcription factors, thereby repressing its activity. Here we report on the further characterization of the UCN mechanism. Results Phenotypic analysis of flowers of ucn-1 plants impaired in floral homeotic gene activity revealed that any of the four floral whorls could produce organs carrying ucn-1 protrusions. The ectopic outgrowths of ucn integuments did not accumulate detectable signals of the auxin and cytokinin reporters DR5rev::GFP and ARR5::GUS, respectively. Furthermore, wild-type and ucn-1 seedlings showed similarly strong callus formation upon in vitro culture on callus-inducing medium. We also show that ovules of ucn-1 plants carrying the dominant ats allele sk21-D exhibited more pronounced protrusion formation. Finally ovules of ucn-1 ett-1 double mutants and ucn-1 ett-1 arf4-1 triple mutants displayed an additive phenotype. Conclusions These data deepen the molecular insight into the UCN-mediated control of planar growth during integument development. The presented evidence indicates that UCN downstream signaling does not involve the control of auxin or cytokinin homeostasis. The results also reveal that UCN interacts with ATS independently of an ATS

Oxide mediated liquid-solid growth of high aspect ratio aligned gold silicide nanowires on Si(110) substrates.

PubMed

Bhatta, Umananda M; Rath, Ashutosh; Dash, Jatis K; Ghatak, Jay; Yi-Feng, Lai; Liu, Chuan-Pu; Satyam, P V

2009-11-18

Silicon nanowires grown using the vapor-liquid-solid method are promising candidates for nanoelectronics applications. The nanowires grow from an Au-Si catalyst during silicon chemical vapor deposition. In this paper, the effect of temperature, oxide at the interface and substrate orientation on the nucleation and growth kinetics during formation of nanogold silicide structures is explained using an oxide mediated liquid-solid growth mechanism. Using real time in situ high temperature transmission electron microscopy (with 40 ms time resolution), we show the formation of high aspect ratio ( approximately 15.0) aligned gold silicide nanorods in the presence of native oxide at the interface during in situ annealing of gold thin films on Si(110) substrates. Steps observed in the growth rate and real time electron diffraction show the existence of liquid Au-Si nano-alloy structures on the surface besides the un-reacted gold nanostructures. These results might enable us to engineer the growth of nanowires and similar structures with an Au-Si alloy as a catalyst.

The Mediator complex: a central integrator of transcription

PubMed Central

Allen, Benjamin L.; Taatjes, Dylan J.

2016-01-01

The RNA polymerase II (pol II) enzyme transcribes all protein-coding and most non-coding RNA genes and is globally regulated by Mediator, a large, conformationally flexible protein complex with variable subunit composition (for example, a four-subunit CDK8 module can reversibly associate). These biochemical characteristics are fundamentally important for Mediator's ability to control various processes important for transcription, including organization of chromatin architecture and regulation of pol II pre-initiation, initiation, re-initiation, pausing, and elongation. Although Mediator exists in all eukaryotes, a variety of Mediator functions appear to be specific to metazoans, indicative of more diverse regulatory requirements. PMID:25693131

The cell biology of bone growth.

PubMed

Price, J S; Oyajobi, B O; Russell, R G

1994-02-01

The field of bone cell biology is clearly of relevance to the problem of stunting in children, as in the final analysis the cells of the growing long bone are the ultimate 'regulators'. It is the alterations in the functions of these cells that manifests as a reduction in height. Normal longitudinal growth is achieved by the coordinated recruitment, proliferation, differentiation, maturation and eventual death of the cells of growth plate and bone. Cellular activity is closely regulated by endocrine factors acting directly or indirectly, with factors produced locally and stored within the bone and cartilage microenvironment having a critical role in intercellular communication. Disruption of any of these processes can lead to growth disturbances, since it only requires a defect in a single gene to have profound effects. Studies in recent years have shed light on the biochemical and molecular effects of cytokines and growth factors and have shown that these regulatory molecules may mediate the effects of certain hormones important in controlling growth. However, the complex interrelationship of these molecules is still not clear. Notwithstanding, understanding of the mechanisms involved in bone remodelling is increasing, as this area attracts much research because of the high incidence of metabolic bone disease in Western society. Although studies of adult bone remodelling are of relevance, there is a requirement for increased research directed specifically at the mechanisms of endochondral ossification and its regulation. Longitudinal bone growth is a challenge to the cell biologist, since it is an accelerated cycle of cellular division and differentiation, within which it is not easy to separate events temporally and spatially. In addition, different regulatory mechanisms are probably important at different stages of growth. Another difficulty impeding progress in this field is the lack of appropriate animal models for research. Much information has come from

Dynamic Control of Excitatory Synapse Development by a Rac1 GEF/GAP Regulatory Complex

PubMed Central

Um, Kyongmi; Niu, Sanyong; Duman, Joseph G.; Cheng, Jinxuan; Tu, Yen-Kuei; Schwechter, Brandon; Liu, Feng; Hiles, Laura; Narayanan, Anjana; Ash, Ryan T.; Mulherkar, Shalaka; Alpadi, Kannan; Smirnakis, Stelios M.; Tolias, Kimberley F.

2014-01-01

SUMMARY The small GTPase Rac1 orchestrates actin-dependent remodeling essential for numerous cellular processes including synapse development. While precise spatiotemporal regulation of Rac1 is necessary for its function, little is known about the mechanisms that enable Rac1 activators (GEFs) and inhibitors (GAPs) to act in concert to regulate Rac1 signaling. Here we identify a regulatory complex composed of a Rac-GEF (Tiam1) and a Rac-GAP (Bcr) that cooperate to control excitatory synapse development. Disruption of Bcr function within this complex increases Rac1 activity and dendritic spine remodeling, resulting in excessive synaptic growth that is rescued by Tiam1 inhibition. Notably, EphB receptors utilize the Tiam1-Bcr complex to control synaptogenesis. Following EphB activation, Tiam1 induces Rac1-dependent spine formation, whereas Bcr prevents Rac1-mediated receptor internalization, promoting spine growth over retraction. The finding that a Rac-specific GEF/GAP complex is required to maintain optimal levels of Rac1 signaling provides an important insight into the regulation of small GTPases. PMID:24960694

Regulatory T Cells in Autoimmune and Viral Chronic Hepatitis

PubMed Central

Lapierre, Pascal; Lamarre, Alain

2015-01-01

In both autoimmune liver disease and chronic viral hepatitis, the injury results from an immune-mediated cytotoxic T cell response to liver cells. As such, it is not surprising that CD4+ regulatory T cells, a key regulatory population of T cells able to curb immune responses, could be involved in both autoimmune hepatitis and chronic viral hepatitis. The liver can induce the conversion of naïve CD4+ T cells to CD4+ regulatory T cells and induce tolerance to locally expressed antigens. This tolerance mechanism is carefully regulated in physiological conditions but any imbalance could be pathological. An overly tolerant immune response can lead to chronic infections while an overreactive and unbridled immune response can lead to autoimmune hepatitis. With the recent advent of monoclonal antibodies able to target regulatory T cells (daclizumab) and improve immune responses and several ongoing clinical trials analysing the impact of regulatory T cell infusion on autoimmune liver disease or liver transplant tolerance, modulation of immunological tolerance through CD4+ regulatory T cells could be a key element of future immunotherapies for several liver diseases allowing restoring the balance between proper immune responses and tolerance.   PMID:26106627

GPR30 Activation Opposes Estrogen-Dependent Uterine Growth via Inhibition of Stromal ERK1/2 and Estrogen Receptor Alpha (ERα) Phosphorylation Signals

PubMed Central

Gao, Fei; Ma, Xinghong; Ostmann, Alicia B.

2011-01-01

Although estradiol-17β (E2)-regulated early and late phase uterine responses have been well defined, the molecular mechanisms linking the phases remain poorly understood. We have previously shown that E2-regulated early signals mediate cross talk with estrogen receptor (ER)-α to elicit uterine late growth responses. G protein-coupled receptor (GPR30) has been implicated in early nongenomic signaling mediated by E2, although its role in E2-dependent uterine biology is unclear. Using selective activation of GPR30 by G-1, we show here a new function of GPR30 in regulating early signaling events, including the inhibition of ERK1/2 and ERα (Ser118) phosphorylation signals and perturbation of growth regulation under the direction of E2 in the mouse uterus. We observed that GPR30 primarily localizes in the uterine epithelial cells, and its activation alters gene expression and mediates inhibition of ERK1/2 and ERα (Ser118) phosphorylation signals in the stromal compartment, suggesting a paracrine signaling is involved. Importantly, viral-driven manipulation of GPR30 or pharmacological inhibition of ERK1/2 activation effectively alters E2-dependent uterine growth responses. Overall, GPR30 is a negative regulator of ERα-dependent uterine growth in response to E2. Our work has uncovered a novel GPR30-regulated inhibitory event, which may be physiologically relevant in both normal and pathological situations to negatively balance ERα-dependent uterine growth regulatory functions induced by E2. PMID:21303939

Nanos-mediated repression of hid protects larval sensory neurons after a global switch in sensitivity to apoptotic signals.

PubMed

Bhogal, Balpreet; Plaza-Jennings, Amara; Gavis, Elizabeth R

2016-06-15

Dendritic arbor morphology is a key determinant of neuronal function. Once established, dendrite branching patterns must be maintained as the animal develops to ensure receptive field coverage. The translational repressors Nanos (Nos) and Pumilio (Pum) are required to maintain dendrite growth and branching of Drosophila larval class IV dendritic arborization (da) neurons, but their specific regulatory role remains unknown. We show that Nos-Pum-mediated repression of the pro-apoptotic gene head involution defective (hid) is required to maintain a balance of dendritic growth and retraction in class IV da neurons and that upregulation of hid results in decreased branching because of an increase in caspase activity. The temporal requirement for nos correlates with an ecdysone-triggered switch in sensitivity to apoptotic stimuli that occurs during the mid-L3 transition. We find that hid is required during pupariation for caspase-dependent pruning of class IV da neurons and that Nos and Pum delay pruning. Together, these results suggest that Nos and Pum provide a crucial neuroprotective regulatory layer to ensure that neurons behave appropriately in response to developmental cues. © 2016. Published by The Company of Biologists Ltd.

Growth suppression of Leydig TM3 cells mediated by aryl hydrocarbon receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iseki, Minoru; Department of Regulation Biology, Faculty of Science, Saitama University, Saitama; Ikuta, Togo

2005-06-17

Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin induces developmental toxicity in reproductive organs. To elucidate the function of AhR, we generated stable transformants of TM3 cells overexpressing wild-type aryl hydrocarbon receptor (AhR) or its mutants which carried mutations in nuclear localization signal or nuclear export signal. In the presence of 3-methylcholanthrene (MC), proliferation of the cells transfected with wild-type AhR was completely suppressed, whereas cells expressing AhR mutants proliferated in a manner equivalent to control TM3 cells, suggesting AhR-dependent growth inhibition. The suppression was associated with up-regulation of cyclin-dependent kinase inhibitor p21{sup Cip1}, which was abolished by pretreatment with actinomycin D. A p38 MAPKmore » specific inhibitor, SB203580, blocked the increase of p21{sup Cip1} mRNA in response to MC. Treatment with indigo, another AhR ligand, failed to increase of p21{sup Cip1} mRNA, although up-regulation of mRNA for CYP1A1 was observed. These data suggest AhR in Leydig cells mediates growth inhibition by inducing p21{sup Cip1}.« less

Vesicle-mediated growth of tubular branches and centimeter-long microtubes from a single molecule.

PubMed

Abbas, Abdennour; Brimer, Andrew; Tian, Limei; d'Avignon, D André; Hameed, Abdulrahman Shahul; Vittal, Jagadese J; Singamaneni, Srikanth

2013-08-12

The mechanism by which small molecules assemble into microscale tubular structures in aqueous solution remains poorly understood, particularly when the initial building blocks are non-amphiphilic molecules and no surfactant is used. It is here shown how a subnanometric molecule, namely p-aminothiophenol (p-ATP), prepared in normal water with a small amount of ethanol, spontaneously assembles into a new class of nanovesicle. Due to Brownian motion, these nanostructures rapidly grow into micrometric vesicles and start budding to yield macroscale tubular branches with a remarkable growth rate of ∼20 μm s⁻¹. A real-time visualization by optical microscopy reveals that tubular growth proceeds by vesicle walk and fusion on the apex (growth cone) and sides of the branches and ultimately leads to the generation of centimeter-long microtubes. This unprecedented growth mechanism is triggered by a pH-activated proton switch and maintained by hydrogen bonding. The vesicle fusion-mediated synthesis suggests that functional microtubes with biological properties can be efficiently prepared with a mixture of appropriate diaminophenyl blocks and the desired macromolecule. The reversibility, timescale, and very high yield (90%) of this synthetic approach make it a valuable model for the investigation of hierarchical and structural transition between organized assemblies with different size scales and morphologies. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tumorigenic properties of iron regulatory protein 2 (IRP2) mediated by its specific 73-amino acids insert.

PubMed

Maffettone, Carmen; Chen, Guohua; Drozdov, Ignat; Ouzounis, Christos; Pantopoulos, Kostas

2010-04-13

Iron regulatory proteins, IRP1 and IRP2, bind to mRNAs harboring iron responsive elements and control their expression. IRPs may also perform additional functions. Thus, IRP1 exhibited apparent tumor suppressor properties in a tumor xenograft model. Here we examined the effects of IRP2 in a similar setting. Human H1299 lung cancer cells or clones engineered for tetracycline-inducible expression of wild type IRP2, or the deletion mutant IRP2(Delta73) (lacking a specific insert of 73 amino acids), were injected subcutaneously into nude mice. The induction of IRP2 profoundly stimulated the growth of tumor xenografts, and this response was blunted by addition of tetracycline in the drinking water of the animals, to turnoff the IRP2 transgene. Interestingly, IRP2(Delta73) failed to promote tumor growth above control levels. As expected, xenografts expressing the IRP2 transgene exhibited high levels of transferrin receptor 1 (TfR1); however, the expression of other known IRP targets was not affected. Moreover, these xenografts manifested increased c-MYC levels and ERK1/2 phosphorylation. A microarray analysis identified distinct gene expression patterns between control and tumors containing IRP2 or IRP1 transgenes. By contrast, gene expression profiles of control and IRP2(Delta73)-related tumors were more similar, consistently with their growth phenotype. Collectively, these data demonstrate an apparent pro-oncogenic activity of IRP2 that depends on its specific 73 amino acids insert, and provide further evidence for a link between IRPs and cancer biology.

Tumorigenic Properties of Iron Regulatory Protein 2 (IRP2) Mediated by Its Specific 73-Amino Acids Insert

PubMed Central

Maffettone, Carmen; Chen, Guohua; Drozdov, Ignat; Ouzounis, Christos; Pantopoulos, Kostas

2010-01-01

Iron regulatory proteins, IRP1 and IRP2, bind to mRNAs harboring iron responsive elements and control their expression. IRPs may also perform additional functions. Thus, IRP1 exhibited apparent tumor suppressor properties in a tumor xenograft model. Here we examined the effects of IRP2 in a similar setting. Human H1299 lung cancer cells or clones engineered for tetracycline-inducible expression of wild type IRP2, or the deletion mutant IRP2Δ73 (lacking a specific insert of 73 amino acids), were injected subcutaneously into nude mice. The induction of IRP2 profoundly stimulated the growth of tumor xenografts, and this response was blunted by addition of tetracycline in the drinking water of the animals, to turnoff the IRP2 transgene. Interestingly, IRP2Δ73 failed to promote tumor growth above control levels. As expected, xenografts expressing the IRP2 transgene exhibited high levels of transferrin receptor 1 (TfR1); however, the expression of other known IRP targets was not affected. Moreover, these xenografts manifested increased c-MYC levels and ERK1/2 phosphorylation. A microarray analysis identified distinct gene expression patterns between control and tumors containing IRP2 or IRP1 transgenes. By contrast, gene expression profiles of control and IRP2Δ73-related tumors were more similar, consistently with their growth phenotype. Collectively, these data demonstrate an apparent pro-oncogenic activity of IRP2 that depends on its specific 73 amino acids insert, and provide further evidence for a link between IRPs and cancer biology. PMID:20405006

Selective regulation of clathrin-mediated epidermal growth factor receptor signaling and endocytosis by phospholipase C and calcium

PubMed Central

Delos Santos, Ralph Christian; Bautista, Stephen; Lucarelli, Stefanie; Bone, Leslie N.; Dayam, Roya M.; Abousawan, John; Botelho, Roberto J.; Antonescu, Costin N.

2017-01-01

Clathrin-mediated endocytosis is a major regulator of cell-surface protein internalization. Clathrin and other proteins assemble into small invaginating structures at the plasma membrane termed clathrin-coated pits (CCPs) that mediate vesicle formation. In addition, epidermal growth factor receptor (EGFR) signaling is regulated by its accumulation within CCPs. Given the diversity of proteins regulated by clathrin-mediated endocytosis, how this process may distinctly regulate specific receptors is a key question. We examined the selective regulation of clathrin-dependent EGFR signaling and endocytosis. We find that perturbations of phospholipase Cγ1 (PLCγ1), Ca2+, or protein kinase C (PKC) impair clathrin-mediated endocytosis of EGFR, the formation of CCPs harboring EGFR, and EGFR signaling. Each of these manipulations was without effect on the clathrin-mediated endocytosis of transferrin receptor (TfR). EGFR and TfR were recruited to largely distinct clathrin structures. In addition to control of initiation and assembly of CCPs, EGF stimulation also elicited a Ca2+- and PKC-dependent reduction in synaptojanin1 recruitment to clathrin structures, indicating broad control of CCP assembly by Ca2+ signals. Hence EGFR elicits PLCγ1-calcium signals to facilitate formation of a subset of CCPs, thus modulating its own signaling and endocytosis. This provides evidence for the versatility of CCPs to control diverse cellular processes. PMID:28814502

3C Protease of Enterovirus D68 Inhibits Cellular Defense Mediated by Interferon Regulatory Factor 7

PubMed Central

Xiang, Zichun; Liu, Lulu; Lei, Xiaobo; Zhou, Zhuo

2015-01-01

ABSTRACT Human enterovirus 68 (EV-D68) is a member of the EV-D species, which belongs to the EV genus of the Picornaviridae family. Over the past several years, clusters of EV-D68 infections have occurred worldwide. A recent outbreak in the United States is the largest one associated with severe respiratory illness and neurological complication. Although clinical symptoms are recognized, the virus remains poorly understood. Here we report that EV-D68 inhibits innate antiviral immunity by downregulation of interferon regulatory factor 7 (IRF7), an immune factor with a pivotal role in viral pathogenesis. This process depends on 3Cpro, an EV-D68-encoded protease, to mediate IRF7 cleavage. When expressed in host cells, 3Cpro targets Q167 and Q189 within the constitutive activation domain, resulting in cleavage of IRF7. Accordingly, wild-type IRF7 is fully active. However, IRF7 cleavage abrogated its capacity to activate type I interferon expression and limit replication of EV-D68. Notably, IRF7 cleavage strictly requires the protease activity of 3Cpro. Together, these results suggest that a dynamic interplay between 3Cpro and IRF7 may determine the outcome of EV-D68 infection. IMPORTANCE EV-D68 is a globally emerging pathogen, but the molecular basis of EV-D68 pathogenesis is unclear. Here we report that EV-D68 inhibits innate immune responses by targeting an immune factor, IRF7. This involves the 3C protease encoded by EV-D68, which mediates the cleavage of IRF7. These observations suggest that the 3Cpro-IRF7 interaction may represent an interface that dictates EV-D68 infection. PMID:26608321

SKI knockdown inhibits human melanoma tumor growth in vivo.

PubMed

Chen, Dahu; Lin, Qiushi; Box, Neil; Roop, Dennis; Ishii, Shunsuke; Matsuzaki, Koichi; Fan, Tao; Hornyak, Thomas J; Reed, Jon A; Stavnezer, Ed; Timchenko, Nikolai A; Medrano, Estela E

2009-12-01

The SKI protein represses the TGF-beta tumor suppressor pathway by associating with the Smad transcription factors. SKI is upregulated in human malignant melanoma tumors in a disease-progression manner and its overexpression promotes proliferation and migration of melanoma cells in vitro. The mechanisms by which SKI antagonizes TGF-beta signaling in vivo have not been fully elucidated. Here we show that human melanoma cells in which endogenous SKI expression was knocked down by RNAi produced minimal orthotopic tumor xenograft nodules that displayed low mitotic rate and prominent apoptosis. These minute tumors exhibited critical signatures of active TGF-beta signaling including high levels of nuclear Smad3 and p21(Waf-1), which are not found in the parental melanomas. To understand how SKI promotes tumor growth we used gain- and loss-of-function approaches and found that simultaneously to blocking the TGF-beta-growth inhibitory pathway, SKI promotes the switch of Smad3 from tumor suppression to oncogenesis by favoring phosphorylations of the Smad3 linker region in melanoma cells but not in normal human melanocytes. In this context, SKI is required for preventing TGF-beta-mediated downregulation of the oncogenic protein c-MYC, and for inducing the plasminogen activator inhibitor-1, a mediator of tumor growth and angiogenesis. Together, the results indicate that SKI exploits multiple regulatory levels of the TGF-beta pathway and its deficiency restores TGF-beta tumor suppressor and apoptotic activities in spite of the likely presence of oncogenic mutations in melanoma tumors.

Nitric oxide-mediated modulation of iron regulatory proteins: implication for cellular iron homeostasis.

PubMed

Kim, Sangwon; Ponka, Prem

2002-01-01

Iron regulatory proteins (IRP1 and IRP2) control the synthesis of transferrin receptors (TfR) and ferritin by binding to iron-responsive elements (IREs) that are located in the 3' untranslated region (UTR) and the 5' UTR of their respective mRNAs. Cellular iron levels affect binding of IRPs to IREs and consequently expression of TfR and ferritin. Moreover, NO(.), a redox species of nitric oxide that interacts primarily with iron, can activate IRP1 RNA-binding activity resulting in an increase in TfR mRNA levels and a decrease in ferritin synthesis. We have shown that treatment of RAW 264.7 cells (a murine macrophage cell line) with NO(+) (nitrosonium ion, which causes S-nitrosylation of thiol groups) resulted in a rapid decrease in RNA-binding of IRP2, followed by IRP2 degradation, and these changes were associated with a decrease in TfR mRNA levels and a dramatic increase in ferritin synthesis. Moreover, we demonstrated that stimulation of RAW 264.7 cells with lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) increased IRP1 binding activity, whereas RNA-binding of IRP2 decreased and was followed by a degradation of this protein. Furthermore, the decrease of IRP2 binding/protein levels was associated with a decrease in TfR mRNA levels and an increase in ferritin synthesis in LPS/IFN-gamma-treated cells, and these changes were prevented by inhibitors of inducible nitric oxide synthase. These results suggest that NO(+)-mediated degradation of IRP2 plays a major role in iron metabolism during inflammation.

Growth Coordination During Drosophila melanogaster Imaginal Disc Regeneration Is Mediated by Signaling Through the Relaxin Receptor Lgr3 in the Prothoracic Gland.

PubMed

Jaszczak, Jacob S; Wolpe, Jacob B; Bhandari, Rajan; Jaszczak, Rebecca G; Halme, Adrian

2016-10-01

Damage to Drosophila melanogaster imaginal discs activates a regeneration checkpoint that (1) extends larval development and (2) coordinates the regeneration of the damaged disc with the growth of undamaged discs. These two systemic responses to damage are both mediated by Dilp8, a member of the insulin/insulin-like growth factor/relaxin family of peptide hormones, which is released by regenerating imaginal discs. Growth coordination between regenerating and undamaged imaginal discs is dependent on Dilp8 activation of nitric oxide synthase (NOS) in the prothoracic gland (PG), which slows the growth of undamaged discs by limiting ecdysone synthesis. Here we demonstrate that the Drosophila relaxin receptor homolog Lgr3, a leucine-rich repeat-containing G-protein-coupled receptor, is required for Dilp8-dependent growth coordination and developmental delay during the regeneration checkpoint. Lgr3 regulates these responses to damage via distinct mechanisms in different tissues. Using tissue-specific RNA-interference disruption of Lgr3 expression, we show that Lgr3 functions in the PG upstream of NOS, and is necessary for NOS activation and growth coordination during the regeneration checkpoint. When Lgr3 is depleted from neurons, imaginal disc damage no longer produces either developmental delay or growth inhibition. To reconcile these discrete tissue requirements for Lgr3 during regenerative growth coordination, we demonstrate that Lgr3 activity in both the CNS and PG is necessary for NOS activation in the PG following damage. Together, these results identify new roles for a relaxin receptor in mediating damage signaling to regulate growth and developmental timing. Copyright © 2016 by the Genetics Society of America.

Environmental toxicants perturb human Sertoli cell adhesive function via changes in F-actin organization mediated by actin regulatory proteins

PubMed Central

Xiao, Xiang; Mruk, Dolores D.; Tang, Elizabeth I.; Wong, Chris K.C.; Lee, Will M.; John, Constance M.; Turek, Paul J.; Silvestrini, Bruno; Cheng, C. Yan

2014-01-01

STUDY QUESTION Can human Sertoli cells cultured in vitro and that have formed an epithelium be used as a model to monitor toxicant-induced junction disruption and to better understand the mechanism(s) by which toxicants disrupt cell adhesion at the Sertoli cell blood–testis barrier (BTB)? SUMMARY ANSWER Our findings illustrate that human Sertoli cells cultured in vitro serve as a reliable system to monitor the impact of environmental toxicants on the BTB function. WHAT IS KNOWN ALREADY Suspicions of a declining trend in semen quality and a concomitant increase in exposures to environmental toxicants over the past decades reveal the need of an in vitro system that efficiently and reliably monitors the impact of toxicants on male reproductive function. Furthermore, studies in rodents have confirmed that environmental toxicants impede Sertoli cell BTB function in vitro and in vivo. STUDY DESIGN, SIZE AND DURATION We examined the effects of two environmental toxicants: cadmium chloride (0.5–20 µM) and bisphenol A (0.4–200 µM) on human Sertoli cell function. Cultured Sertoli cells from three men were used in this study, which spanned an 18-month period. PARTICIPANTS/MATERIALS, SETTING, METHODS Human Sertoli cells from three subjects were cultured in F12/DMEM containing 5% fetal bovine serum. Changes in protein expression were monitored by immunoblotting using specific antibodies. Immunofluorescence analyses were used to assess changes in the distribution of adhesion proteins, F-actin and actin regulatory proteins following exposure to two toxicants: cadmium chloride and bisphenol A (BPA). MAIN RESULTS AND THE ROLE OF CHANCE Human Sertoli cells were sensitive to cadmium and BPA toxicity. Changes in the localization of cell adhesion proteins were mediated by an alteration of the actin-based cytoskeleton. This alteration of F-actin network in Sertoli cells as manifested by truncation and depolymerization of actin microfilaments at the Sertoli cell BTB was caused by

What dictates which ion, I- or Br-, mediates the growth of cubic Pd nanocrystals?

PubMed

Wang, Ze-Hong; Wu, Ya-Jiao; Xue, Huan-Huan; Zhou, Lin-Nan; Geng, Wen-Chao; Yi, Hai-Bo; Li, Yong-Jun

2018-04-25

Cubic Pd nanocrystals (CPNCs) as one of typical nanostructures are generally fabricated using I- or Br- as capping ions. However, which ion, I- or Br-, exclusively mediates the growth of CPNCs in a given reaction system is not well understood. Herein, regardless of I- or Br- as the capping ion, we successfully achieved CPNCs in the same reaction system simply by adjusting the pH. Based on the Finke-Watzky kinetic model, an increase in pH accelerates the overall reduction rate of Pd2+, and the formation of CPNCs only occurs over the range of specific solution reduction rate constants (k1). This kinetically illuminates that the reduction rate of Pd2+ is the physicochemical parameter that determines which ion, I- or Br-, dictates the growth of CPNCs. Also, density functional theory (DFT) calculations further elucidate the dependence of the reduction rate of Pd2+ on pH and the configuration of the activated Pd2+ complex.

Suppression of polymorphonuclear (PMN) and monocyte-mediated inhibition of Candida albicans growth by delta-9-tetrahydrocannabinol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Djeu, J.Y.; Parapanios, A.; Halkias, D.

This study was an in vitro attempt to identify the effector cells responsible for growth inhibition of the opportunistic fungus, candida albicans, and to determine if THC or another marijuana derivatives, 11-hydroxyTHC, would adversely affect their function. Using a 24h radiolabel assay, the authors found that growth inhibition of C. albicans was primarily mediated by PMN and monocytes that could be isolated normal human peripheral blood. Both effector cell types caused almost complete inhibition of Candida growth at effector/target ratio of 300/1 and inhibition was often still seen at 30/1-. Incubation of PMN, PBL, or monocytes for 1 hr atmore » 37C with THC or 11-hydroxyTHC caused a marked suppression of function in all 3 cell populations. Maximal suppression was obtained with 7.5-10..mu..g/ml of the drugs in medium containing 10% fetal bovine serum (FBS) or with 2-4..mu..g/ml in 1% FBS. These drug concentrations did not affect lymphoid cell viability or candida growth in the absence of lymphoid effector cells. Marijuana derivatives, therefore, are doubly dangerous in that opportunistic fungi such as C. albicans can grow in their presence while the effector cells that control fungal growth are readily inactivated.« less

The association of birth weight and infant growth with childhood autonomic nervous system activity and its mediating effects on energy-balance-related behaviours-the ABCD study.

PubMed

van Deutekom, Arend W; Chinapaw, Mai Jm; Gademan, Maaike Gj; Twisk, Jos Wr; Gemke, Reinoud Jbj; Vrijkotte, Tanja Gm

2016-08-01

The purpose of this study was to examine the association of birth weight and infant growth with childhood autonomic nervous system (ANS) activity and to assess whether ANS activity mediates the associations of birth weight and infant growth with energy-balance-related behaviours, including energy intake, satiety response, physical activity and screen time. In 2089 children, we prospectively collected birth weight, infant growth defined as conditional weight and height gain between birth and 12 months and-at 5 years-indices of cardiac ANS activity and parent-reported energy-balance-related behaviours. A mediation analysis was conducted, based on MacKinnon's multivariate extension of the product-of-coefficients strategy. Birth weight and infant height gain were inversely associated with sympathetic, but not parasympathetic, activity at age 5. Infant weight gain was not associated with childhood ANS activity. Infant weight gain was predictive of increased childhood screen time and infant height gain of diminished childhood energy intake, but sympathetic activity did not mediate these associations. Low-birth-weight children have higher sympathetic activity, which is considered a risk factor for cardiovascular disease. Height gain in infancy seems to be beneficial for childhood sympathetic activity. However, sympathetic activity was no mediator of the associations of infant growth with childhood energy-balance-related behaviours. As individual differences in ANS activity predict increased risk of cardiovascular disease, these differences may offer insight into the early-life origins of chronic diseases and provide further basis for public health strategies to optimize birth weight and infant growth. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

Ipilimumab-dependent cell-mediated cytotoxicity of regulatory T cells ex vivo by nonclassical monocytes in melanoma patients

PubMed Central

Romano, Emanuela; Kusio-Kobialka, Monika; Foukas, Periklis G.; Baumgaertner, Petra; Meyer, Christiane; Ballabeni, Pierluigi; Michielin, Olivier; Weide, Benjamin; Romero, Pedro; Speiser, Daniel E.

2015-01-01

Enhancing immune responses with immune-modulatory monoclonal antibodies directed to inhibitory immune receptors is a promising modality in cancer therapy. Clinical efficacy has been demonstrated with antibodies blocking inhibitory immune checkpoints such as cytotoxic T lymphocyte–associated antigen 4 (CTLA-4) or PD-1/PD-L1. Treatment with ipilimumab, a fully human CTLA-4–specific mAb, showed durable clinical efficacy in metastatic melanoma; its mechanism of action is, however, only partially understood. This is a study of 29 patients with advanced cutaneous melanoma treated with ipilimumab. We analyzed peripheral blood mononuclear cells (PBMCs) and matched melanoma metastases from 15 patients responding and 14 not responding to ipilimumab by multicolor flow cytometry, antibody-dependent cell-mediated cytotoxicity (ADCC) assay, and immunohistochemistry. PBMCs and matched tumor biopsies were collected 24 h before (i.e., baseline) and up to 4 wk after ipilimumab. Our findings show, to our knowledge for the first time, that ipilimumab can engage ex vivo FcγRIIIA (CD16)-expressing, nonclassical monocytes resulting in ADCC-mediated lysis of regulatory T cells (Tregs). In contrast, classical CD14++CD16− monocytes are unable to do so. Moreover, we show that patients responding to ipilimumab display significantly higher baseline peripheral frequencies of nonclassical monocytes compared with nonresponder patients. In the tumor microenvironment, responders have higher CD68+/CD163+ macrophage ratios at baseline and show decreased Treg infiltration after treatment. Together, our results suggest that anti–CTLA-4 therapy may target Tregs in vivo. Larger translational studies are, however, warranted to substantiate this mechanism of action of ipilimumab in patients. PMID:25918390

"Letting myself go forward past wrongs": How regulatory modes affect self-forgiveness

PubMed Central

Giannini, Anna Maria; Higgins, E. Tory; Kruglanski, Arie W.

2018-01-01

The present research addresses the question of whether regulatory-mode orientations affect self-forgiveness. We expected that people with a strong locomotion orientation would be more inclined to self-forgiveness because of their tendencies toward movement and change, which focus them on the future, whereas people with a strong assessment orientation would refrain from self-forgiveness due to their evaluative tendencies which focus them on the past. These hypotheses were supported by the results in four studies that tested the relation between regulatory modes and self-forgiveness by measuring (Studies 1, 3 and 4) and manipulating (Study 2) regulatory-mode-orientations. Finally, in Study 4 we examined more closely our hypothesis that the relation between self-forgiveness and regulatory modes is mediated by past and future temporal foci. The implications of the results for regulatory mode theory are also discussed. PMID:29529065

"Letting myself go forward past wrongs": How regulatory modes affect self-forgiveness.

PubMed

Pierro, Antonio; Pica, Gennaro; Giannini, Anna Maria; Higgins, E Tory; Kruglanski, Arie W

2018-01-01

The present research addresses the question of whether regulatory-mode orientations affect self-forgiveness. We expected that people with a strong locomotion orientation would be more inclined to self-forgiveness because of their tendencies toward movement and change, which focus them on the future, whereas people with a strong assessment orientation would refrain from self-forgiveness due to their evaluative tendencies which focus them on the past. These hypotheses were supported by the results in four studies that tested the relation between regulatory modes and self-forgiveness by measuring (Studies 1, 3 and 4) and manipulating (Study 2) regulatory-mode-orientations. Finally, in Study 4 we examined more closely our hypothesis that the relation between self-forgiveness and regulatory modes is mediated by past and future temporal foci. The implications of the results for regulatory mode theory are also discussed.

Reactive Oxygen Species/Hypoxia-Inducible Factor-1α/Platelet-Derived Growth Factor-BB Autocrine Loop Contributes to Cocaine-Mediated Alveolar Epithelial Barrier Damage

PubMed Central

Yang, Lu; Chen, Xufeng; Simet, Samantha M.; Hu, Guoku; Cai, Yu; Niu, Fang; Kook, Yeonhee

2016-01-01

Abuse of psychostimulants, such as cocaine, has been shown to be closely associated with complications of the lung, such as pulmonary hypertension, edema, increased inflammation, and infection. However, the mechanism by which cocaine mediates impairment of alveolar epithelial barrier integrity that underlies various pulmonary complications has not been well determined. Herein, we investigate the role of cocaine in disrupting the alveolar epithelial barrier function and the associated signaling cascade. Using the combinatorial electric cell–substrate impedance sensing and FITC-dextran permeability assays, we demonstrated cocaine-mediated disruption of the alveolar epithelial barrier, as evidenced by increased epithelial monolayer permeability with a concomitant loss of the tight junction protein zonula occludens-1 (Zo-1) in both mouse primary alveolar epithelial cells and the alveolar epithelial cell line, L2 cells. To dissect the signaling pathways involved in this process, we demonstrated that cocaine-mediated induction of permeability factors, platelet-derived growth factor (PDGF-BB) and vascular endothelial growth factor, involved reactive oxygen species (ROS)-dependent induction of hypoxia-inducible factor (HIF)-1α. Interestingly, we demonstrated that ROS-dependent induction of another transcription factor, nuclear factor erythroid-2–related factor-2, that did not play a role in cocaine-mediated barrier dysfunction. Importantly, this study identifies, for the first time, that ROS/HIF-1α/PDGF-BB autocrine loop contributes to cocaine-mediated barrier disruption via amplification of oxidative stress and downstream signaling. Corroboration of these cell culture findings in vivo demonstrated increased permeability of the alveolar epithelial barrier, loss of expression of Zo-1, and a concomitantly increased expression of both HIF-1α and PDGF-BB. Pharmacological blocking of HIF-1α significantly abrogated cocaine-mediated loss of Zo-1. Understanding the

Transforming growth factor beta mediates the progesterone suppression of an epithelial metalloproteinase by adjacent stroma in the human endometrium.

PubMed Central

Bruner, K L; Rodgers, W H; Gold, L I; Korc, M; Hargrove, J T; Matrisian, L M; Osteen, K G

1995-01-01

Unlike most normal adult tissues, cyclic growth and tissue remodeling occur within the uterine endometrium throughout the reproductive years. The matrix metalloproteinases (MMPs), a family of structurally related enzymes that degrade specific components of the extracellular matrix are thought to be the physiologically relevant mediators of extracellular matrix composition and turnover. Our laboratory has identified MMPs of the stromelysin family in the cycling human endometrium, implicating these enzymes in mediating the extensive remodeling that occurs in this tissue. While the stromelysins are expressed in vivo during proliferation-associated remodeling and menstruation-associated endometrial breakdown, none of the stromelysins are expressed during the progesterone-dominated secretory phase of the cycle. Our in vitro studies of isolated cell types have confirmed progesterone suppression of stromal MMPs, but a stromal-derived paracrine factor was found necessary for suppression of the epithelial-specific MMP matrilysin. In this report, we demonstrate that transforming growth factor beta (TGF-beta) is produced by endometrial stroma in response to progesterone and can suppress expression of epithelial matrilysin independent of progesterone. Additionally, we find that an antibody directed against the mammalian isoforms of TGF-beta abolishes progesterone suppression of matrilysin in stromal-epithelial cocultures, implicating TGF-beta as the principal mediator of matrilysin suppression in the human endometrium. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:7638197

Cigarette smoke-induced cell cycle arrest in spermatocytes [GC-2spd(ts)] is mediated through crosstalk between Ahr-Nrf2 pathway and MAPK signaling.

PubMed

Esakky, Prabagaran; Hansen, Deborah A; Drury, Andrea M; Moley, Kelle H

2015-02-01

Our earlier studies have demonstrated that the cigarette smoke in the form of cigarette smoke condensate (CSC) causes growth arrest of a mouse spermatocyte cell line [GC-2spd(ts)] through activation of the AHR-NRF2 pathway. The present study demonstrates the CSC-activated p38 and ERK MAPK signaling in GC-2spd(ts) via arylhydrocarbon receptor (AHR). Pharmacological inhibition by using AHR-antagonist, or p38 MAPK and ERK (MEK1) inhibitors significantly abrogates CSC-induced growth arrest by AHR and MAPK inactivation. QRT-PCR, western blot, and immunofluorescence of Ahr-target of Nrf2, and stress-inducible growth suppressive Atf3 and E2f4 following treatments indicate a crosstalk among these pathways. Regulation of Atf3 by Nrf2 and Ahr through RNA interference suggests the existence of a cross-regulatory loop between the targets. CSC induction of E2f4 via Atf3 and its regulation by pharmacological inhibitors reveal a possible regulatory mechanism of growth inhibitory CSC. SiRNA silencing of Ahr, Nrf2, Atf3, and E2f4 genes and downregulation of cyclins by CSC corroborate the growth inhibitory effect of cigarette smoke. Thus, the data obtained suggest that the CSC-mediated MAPKs and AHR-NRF2 crosstalks lay the molecular basis for the growth arrest and cell death of spermatocytes. © The Author (2014). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, IBCB, SIBS, CAS. All rights reserved.

The Moderated Mediating Effect of Self-Efficacy on Exercise Among Older Adults in an Online Bone Health Intervention Study: A Parallel Process Latent Growth Curve Model.

PubMed

Zhu, Shijun; Nahm, Eun-Shim; Resnick, Barbara; Friedmann, Erika; Brown, Clayton; Park, Jumin; Cheon, Jooyoung; Park, DoHwan

2017-07-01

This secondary data analyses of a longitudinal study assessed whether self-efficacy for exercise (SEE) mediated online intervention effects on exercise among older adults and whether age (50-64 vs. ≥65 years) moderated the mediation. Data were from an online bone health intervention study. Eight hundred sixty-six older adults (≥50 years) were randomized to three arms: Bone Power (n = 301), Bone Power Plus (n = 302), or Control (n = 263). Parallel process latent growth curve modeling (LGCM) was used to jointly model growths in SEE and in exercise and to assess the mediating effect of SEE on the effect of intervention on exercise. SEE was a significant mediator in 50- to 64-year-old adults (0.061, 95 BCI: 0.011, 0.163) but not in the ≥65 age group (-0.004, 95% BCI: -0.047, 0.025). Promotion of SEE is critical to improve exercise among 50- to 64-year-olds.

Coordination of the Arc Regulatory System and Pheromone-Mediated Positive Feedback in Controlling the Vibrio fischeri lux Operon

PubMed Central

Septer, Alecia N.; Stabb, Eric V.

2012-01-01

Bacterial pheromone signaling is often governed both by environmentally responsive regulators and by positive feedback. This regulatory combination has the potential to coordinate a group response among distinct subpopulations that perceive key environmental stimuli differently. We have explored the interplay between an environmentally responsive regulator and pheromone-mediated positive feedback in intercellular signaling by Vibrio fischeri ES114, a bioluminescent bacterium that colonizes the squid Euprymna scolopes. Bioluminescence in ES114 is controlled in part by N-(3-oxohexanoyl)-L-homoserine lactone (3OC6), a pheromone produced by LuxI that together with LuxR activates transcription of the luxICDABEG operon, initiating a positive feedback loop and inducing luminescence. The lux operon is also regulated by environmentally responsive regulators, including the redox-responsive ArcA/ArcB system, which directly represses lux in culture. Here we show that inactivating arcA leads to increased 3OC6 accumulation to initiate positive feedback. In the absence of positive feedback, arcA-mediated control of luminescence was only ∼2-fold, but luxI-dependent positive feedback contributed more than 100 fold to the net induction of luminescence in the arcA mutant. Consistent with this overriding importance of positive feedback, 3OC6 produced by the arcA mutant induced luminescence in nearby wild-type cells, overcoming their ArcA repression of lux. Similarly, we found that artificially inducing ArcA could effectively repress luminescence before, but not after, positive feedback was initiated. Finally, we show that 3OC6 produced by a subpopulation of symbiotic cells can induce luminescence in other cells co-colonizing the host. Our results suggest that even transient loss of ArcA-mediated regulation in a sub-population of cells can induce luminescence in a wider community. Moreover, they indicate that 3OC6 can communicate information about both cell density and the state of

Investigating the use of in situ liquid cell scanning transmission electron microscopy to explore DNA-mediated gold nanoparticle growth

NASA Astrophysics Data System (ADS)

Nguy, Amanda

Engineering nanoparticles with desired shape-dependent properties is the key to many applications in nanotechnology. Although many synthetic procedures exist to produce anisotropic gold nanoparticles, the dynamics of growth are typically unknown or hypothetical. In the case of seed-mediated growth in the presence of DNA into anisotropic nanoparticles, it is not known exactly how DNA directs growth into specific morphologies. A series of preliminary experiments were carried out to contribute to the investigation of the possible mechanism of DNA-mediated growth of gold nanoprisms into gold nanostars using liquid cell scanning transmission electron microscopy (STEM). Imaging in the liquid phase was achieved through the use of a liquid cell platform and liquid cell holder that allow the sample to be contained within a “chip sandwich” between two electron transparent windows. Ex situ growth experiments were performed using Au-T30 NPrisms (30-base thymine oligonucleotide-coated gold nanoprisms) that are expected to grow into gold nanostars. Growth to form these nanostars were imaged using TEM (transmission electron microscopy) and liquid cell STEM (scanning transmission electron microscopy). An attempt to perform in situ growth experiments with the same Au-T30 nanoprisms revealed challenges in obtaining desired morphology results due to the environmental differences within the liquid cell compared to the ex situ environment. Different parameters in the experimental method were explored including fluid line set up, simultaneous and alternating reagent addition, and the effect of different liquid cell volumes to ensure adequate flow of reagents into the liquid cell. Lastly, the binding affinities were compared for T30 and A30 DNA incubated with gold nanoparticles using zeta potential measurements, absorption spectroscopy, and isothermal titration calorimetry (ITC). It was previously reported thymine bases have a lower binding affinity to gold surfaces than

Insulin-like growth factor-I, physical activity, and control of cellular anabolism.

PubMed

Nindl, Bradley C

2010-01-01

The underlying mechanisms responsible for mediating the beneficial outcomes of exercise undoubtedly are many, but the insulin-like growth factor-I (IGF-I) system is emerging as an important and central hormonal axis that plays a significant role concerning cellular anabolism. This introductory article summarizes the intent and the content for papers presented as part of a 2008 American College of Sports Medicine national symposium entitled "Insulin-like Growth Factor-I, Physical Activity, and Control of Cellular Anabolism." The individual authors and their papers are as follows: Jan Frystyk authoring "The relationship between exercise and the growth hormone/insulin-like growth factor-I axis," Greg Adams authoring "IGF-I signaling in skeletal muscle and the potential for cytokine interactions," and Brad Nindl authoring "Insulin-like growth factor-I as a biomarker of health, fitness, and training status." These papers focus on 1) different assay methodologies for IGF-I within the paradigm of exercise studies, 2) research demonstrating that intracellular signaling components associated with several proinflammatory cytokines have the potential to interact with anabolic signaling processes in skeletal muscle, and 3) an overview of IGF-I as a biomarker related to exercise training, muscle and bone remodeling, body composition, cognition, and cancer. When summed in total, the contribution that these papers will make will undoubtedly involve bringing attention to the vast regulatory complexity of the IGF-I system and will hopefully convince the reader that the IGF-I system warrants further detailed scientific inquiry to resolve many unanswered questions and paradoxical experimental findings. The IGF-I system remains one of the most intriguing and captivating marvels of human physiology that seems central in mediating numerous adaptations from physical activity.

Synthesis and characterization of gold nanodogbones by the seeded mediated growth method

NASA Astrophysics Data System (ADS)

Huang, Chien-Jung; Chiu, Pin-Hsiang; Wang, Yeong-Her; Meen, Teen-Hang; Yang, Cheng-Fu

2007-10-01

Novel gold nanodogbones (GDBs) are successfully fabricated using a simple seeded mediated growth (SMG) method. The shapes of GDBs depend on the amount of added vitamin C solvent. The amount of vitamin C solvent was varied from 10 to 40 µl to investigate the influence of vitamin C solvent on the GDBs. It is found that the aspect ratios (R) of GDBs were in the range from 2.34 to 1.46, and the UV-vis absorption measurement revealed a pronounced blueshift on the longitudinal surface plasmon resonance (SPR) band from 713 to 676 nm. The GDBs were determined by x-ray diffraction (XRD) to be single-crystalline with a face-centered cubic (fcc) structure. The lattice constant calculated from this selected-area electron diffraction (SAED) pattern is 4.068 Å.

BPM-CUL3 E3 ligase modulates thermotolerance by facilitating negative regulatory domain-mediated degradation of DREB2A in Arabidopsis.

PubMed

Morimoto, Kyoko; Ohama, Naohiko; Kidokoro, Satoshi; Mizoi, Junya; Takahashi, Fuminori; Todaka, Daisuke; Mogami, Junro; Sato, Hikaru; Qin, Feng; Kim, June-Sik; Fukao, Yoichiro; Fujiwara, Masayuki; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

2017-10-03

DEHYDRATION-RESPONSIVE ELEMENT BINDING PROTEIN 2A (DREB2A) acts as a key transcription factor in both drought and heat stress tolerance in Arabidopsis and induces the expression of many drought- and heat stress-inducible genes. Although DREB2A expression itself is induced by stress, the posttranslational regulation of DREB2A, including protein stabilization, is required for its transcriptional activity. The deletion of a 30-aa central region of DREB2A known as the negative regulatory domain (NRD) transforms DREB2A into a stable and constitutively active form referred to as DREB2A CA. However, the molecular basis of this stabilization and activation has remained unknown for a decade. Here we identified BTB/POZ AND MATH DOMAIN proteins (BPMs), substrate adaptors of the Cullin3 (CUL3)-based E3 ligase, as DREB2A-interacting proteins. We observed that DREB2A and BPMs interact in the nuclei, and that the NRD of DREB2A is sufficient for its interaction with BPMs. BPM -knockdown plants exhibited increased DREB2A accumulation and induction of DREB2A target genes under heat and drought stress conditions. Genetic analysis indicated that the depletion of BPM expression conferred enhanced thermotolerance via DREB2A stabilization. Thus, the BPM-CUL3 E3 ligase is likely the long-sought factor responsible for NRD-dependent DREB2A degradation. Through the negative regulation of DREB2A stability, BPMs modulate the heat stress response and prevent an adverse effect of excess DREB2A on plant growth. Furthermore, we found the BPM recognition motif in various transcription factors, implying a general contribution of BPM-mediated proteolysis to divergent cellular responses via an accelerated turnover of transcription factors.

BPM-CUL3 E3 ligase modulates thermotolerance by facilitating negative regulatory domain-mediated degradation of DREB2A in Arabidopsis

PubMed Central

Morimoto, Kyoko; Ohama, Naohiko; Kidokoro, Satoshi; Mizoi, Junya; Takahashi, Fuminori; Todaka, Daisuke; Mogami, Junro; Sato, Hikaru; Qin, Feng; Kim, June-Sik; Fukao, Yoichiro; Fujiwara, Masayuki; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

2017-01-01

DEHYDRATION-RESPONSIVE ELEMENT BINDING PROTEIN 2A (DREB2A) acts as a key transcription factor in both drought and heat stress tolerance in Arabidopsis and induces the expression of many drought- and heat stress-inducible genes. Although DREB2A expression itself is induced by stress, the posttranslational regulation of DREB2A, including protein stabilization, is required for its transcriptional activity. The deletion of a 30-aa central region of DREB2A known as the negative regulatory domain (NRD) transforms DREB2A into a stable and constitutively active form referred to as DREB2A CA. However, the molecular basis of this stabilization and activation has remained unknown for a decade. Here we identified BTB/POZ AND MATH DOMAIN proteins (BPMs), substrate adaptors of the Cullin3 (CUL3)-based E3 ligase, as DREB2A-interacting proteins. We observed that DREB2A and BPMs interact in the nuclei, and that the NRD of DREB2A is sufficient for its interaction with BPMs. BPM-knockdown plants exhibited increased DREB2A accumulation and induction of DREB2A target genes under heat and drought stress conditions. Genetic analysis indicated that the depletion of BPM expression conferred enhanced thermotolerance via DREB2A stabilization. Thus, the BPM-CUL3 E3 ligase is likely the long-sought factor responsible for NRD-dependent DREB2A degradation. Through the negative regulation of DREB2A stability, BPMs modulate the heat stress response and prevent an adverse effect of excess DREB2A on plant growth. Furthermore, we found the BPM recognition motif in various transcription factors, implying a general contribution of BPM-mediated proteolysis to divergent cellular responses via an accelerated turnover of transcription factors. PMID:28923951

Arf6 Guanine Nucleotide Exchange Factor Cytohesin-2 Binds to CCDC120 and Is Transported Along Neurites to Mediate Neurite Growth*

PubMed Central

Torii, Tomohiro; Miyamoto, Yuki; Tago, Kenji; Sango, Kazunori; Nakamura, Kazuaki; Sanbe, Atsushi; Tanoue, Akito; Yamauchi, Junji

2014-01-01

The mechanism of neurite growth is complicated, involving continuous cytoskeletal rearrangement and vesicular trafficking. Cytohesin-2 is a guanine nucleotide exchange factor for Arf6, an Arf family molecular switch protein, controlling cell morphological changes such as neuritogenesis. Here, we show that cytohesin-2 binds to a protein with a previously unknown function, CCDC120, which contains three coiled-coil domains, and is transported along neurites in differentiating N1E-115 cells. Transfection of the small interfering RNA (siRNA) specific for CCDC120 into cells inhibits neurite growth and Arf6 activation. When neurites start to extend, vesicles containing CCDC120 and cytohesin-2 are transported in an anterograde manner rather than a retrograde one. As neurites continue extension, anterograde vesicle transport decreases. CCDC120 knockdown inhibits cytohesin-2 localization into vesicles containing CCDC120 and diffuses cytohesin-2 in cytoplasmic regions, illustrating that CCDC120 determines cytohesin-2 localization in growing neurites. Reintroduction of the wild type CCDC120 construct into cells transfected with CCDC120 siRNA reverses blunted neurite growth and Arf6 activity, whereas the cytohesin-2-binding CC1 region-deficient CCDC120 construct does not. Thus, cytohesin-2 is transported along neurites by vesicles containing CCDC120, and it mediates neurite growth. These results suggest a mechanism by which guanine nucleotide exchange factor for Arf6 is transported to mediate neurite growth. PMID:25326380

RNA-mediated regulation in Gram-positive pathogens: an overview punctuated with examples from the group A Streptococcus

PubMed Central

Miller, Eric W.; Cao, Tram N.; Pflughoeft, Kathryn J.; Sumby, Paul

2014-01-01

RNA-based mechanisms of regulation represent a ubiquitous class of regulators that are associated with diverse processes including nutrient sensing, stress response, modulation of horizontal gene transfer, and virulence factor expression. While better studied in Gram-negative bacteria, the literature is replete with examples of the importance of RNA-mediated regulatory mechanisms to the virulence and fitness of Gram-positives. Regulatory RNAs are classified as cis-acting, e.g. riboswitches, which modulate the transcription, translation, or stability of co-transcribed RNA, or trans-acting, e.g. small regulatory RNAs, which target separate mRNAs or proteins. The group A Streptococcus (GAS, Streptococcus pyogenes) is a Gram-positive bacterial pathogen from which several regulatory RNA mechanisms have been characterized. The study of RNA-mediated regulation in GAS has uncovered novel concepts with respect to how small regulatory RNAs may positively regulate target mRNA stability, and to how CRISPR RNAs are processed from longer precursors. This review provides an overview of RNA-mediated regulation in Gram-positive bacteria, and is highlighted with specific examples from GAS research. The key roles that these systems play in regulating bacterial virulence are discussed and future perspectives outlined. PMID:25091277

Chromatin Accessibility Mapping Identifies Mediators of Basal Transcription and Retinoid-Induced Repression of OTX2 in Medulloblastoma

PubMed Central

Zhang, Monica; Song, Lingyun; Lee, Bum-Kyu; Iyer, Vishwanath R.; Furey, Terrence S.; Crawford, Gregory E.; Yan, Hai; He, Yiping

2014-01-01

Despite an emerging understanding of the genetic alterations giving rise to various tumors, the mechanisms whereby most oncogenes are overexpressed remain unclear. Here we have utilized an integrated approach of genomewide regulatory element mapping via DNase-seq followed by conventional reporter assays and transcription factor binding site discovery to characterize the transcriptional regulation of the medulloblastoma oncogene Orthodenticle Homeobox 2 (OTX2). Through these studies we have revealed that OTX2 is differentially regulated in medulloblastoma at the level of chromatin accessibility, which is in part mediated by DNA methylation. In cell lines exhibiting chromatin accessibility of OTX2 regulatory regions, we found that autoregulation maintains OTX2 expression. Comparison of medulloblastoma regulatory elements with those of the developing brain reveals that these tumors engage a developmental regulatory program to drive OTX2 transcription. Finally, we have identified a transcriptional regulatory element mediating retinoid-induced OTX2 repression in these tumors. This work characterizes for the first time the mechanisms of OTX2 overexpression in medulloblastoma. Furthermore, this study establishes proof of principle for applying ENCODE datasets towards the characterization of upstream trans-acting factors mediating expression of individual genes. PMID:25198066

Solution-mediated growth of NBA-ZSM-5 crystals retarded by gel entrapment

NASA Astrophysics Data System (ADS)

Aguilar-Mamani, Wilson; Akhtar, Farid; Hedlund, Jonas; Mouzon, Johanne

2018-04-01

The synthesis of flat tablet-shaped ZSM-5 crystals from a gel using metakaolin as aluminosilicate source and n-butyl amine as structure directing agent was investigated. The evolution inside the solid phase was characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, thermogravimetry and mass spectrometry. A kinetic study indicated that the nucleation of the majority crystals occurred concurrently with the formation of the gel upon heating the starting liquid suspension. Microstructural evidences undeniably showed that the gel precipitated on ZSM-5 crystals and mineral impurities originating from kaolin. As a result, crystal growth was retarded by gel entrapment, as indicated by the configuration and morphology of the embedded crystals. The results presented herein are harmonized with a solution-mediated nucleation and growth mechanism. Our observations differ from the autocatalytic model that suggests that the nuclei rest inside the gel until released when the gel is consumed. Our results show instead that it is crystals that formed in an early stage before entrapment inside the gel that rest inside the gel until exposed at the gel surface. These results illustrate the limitation of the classical method used in the field to determine nucleation profiles when the crystals become trapped inside the gel.

[Lentiviral vector-mediated short hairpin RNA targeting survivin inhibits abdominal growth of human endometrium xenograft in nude mice].

PubMed

Peng, Dongxian; He, Yuanli

2015-02-01

To investigate the inhibitory effect of lentiviral vector-mediated short hairpin RNA targeting survivin (LV-survivin shRNA) on the growth of human endometrium xenograft in the abdominal cavity of nude mice. The endometrium xenografts from 8 women with endometriosis were injected into the peritoneal cavities of 45 nude mice. The mice were then randomly assigned to receive intraperitoneal injection of LV-survivin shRNA, pGCL-NC-GFP (negative control) or PBS (blank control). Two weeks later, the number and morphometry of endometriotic lesions were quantified and the expression of survivin protein were detected by immunohistochemistry. The formation of endometriotic lesions was significantly suppressed in mice receiving LV-survivin shRNA injection as compared with those in the two control groups (P/0.001). The mice in LV-survivin-shRNA group showed significantly down-regulated expression levels of survivin protein compared with those in the negative and blank control groups, presenting also necrosis in the endometriosis-like lesions in microscopic observation. Lentiviral vector-mediated shRNA can effectively inhibit the expression of survivin in human endometrium xengrafts and suppress the formation and growth of endometriotic lesions in the abdominal cavities of nude mice.

Regulatory role of calpain in neuronal death

PubMed Central

Cheng, Si-ying; Wang, Shu-chao; Lei, Ming; Wang, Zhen; Xiong, Kun

2018-01-01

Calpains are a group of calcium-dependent proteases that are over activated by increased intracellular calcium levels under pathological conditions. A wide range of substrates that regulate necrotic, apoptotic and autophagic pathways are affected by calpain. Calpain plays a very important role in neuronal death and various neurological disorders. This review introduces recent research progress related to the regulatory mechanisms of calpain in neuronal death. Various neuronal programmed death pathways including apoptosis, autophagy and regulated necrosis can be divided into receptor interacting protein-dependent necroptosis, mitochondrial permeability transition-dependent necrosis, pyroptosis and poly (ADP-ribose) polymerase 1-mediated parthanatos. Calpains cleave series of key substrates that may lead to cell death or participate in cell death. Regarding the investigation of calpain-mediated programed cell death, it is necessary to identify specific inhibitors that inhibit calpain mediated neuronal death and nervous system diseases. PMID:29623944

Intrinsic catch-up growth of hypoplastic fetal lungs is mediated by interleukin-6.

PubMed

Nogueira-Silva, Cristina; Moura, Rute S; Esteves, Nuno; Gonzaga, Sílvia; Correia-Pinto, Jorge

2008-07-01

Fetal lung hypoplasia is a common finding in several fetal conditions such as congenital diaphragmatic hernia (CDH). Interestingly, previous studies have demonstrated that hypoplastic lungs have the ability to recover to normal size, when relieved from mechanical factors. However, the underlying mechanisms remain largely unknown. Recently, interleukin-6 (IL-6) has been involved in catch-up growth phenomenon in children. Thus, we hypothesized that IL-6 could mediate fetal growth recover from hypoplastic lungs. Control and nitrofen-induced hypoplastic lung explants were cultured either in normal conditions or with IL-6 neutralizing antibodies. The total number of peripheral airway buds, epithelial perimeter, and total explant area were analyzed and daily branching rates were calculated. Additionally, IL-6 mRNA and protein expression was assessed both in qualitative (by in situ hybridization and immunohistochemistry) and in quantitative (by real-time PCR and Western blot) approaches, in control and hypoplastic lungs (nitrofen and CDH groups). Nitrofen-induced hypoplastic lungs showed in vitro, out of systemic environment, the ability to recover from hypoplasia and presented daily branching rates significantly higher than controls. Blocking IL-6 activity significantly diminished the intrinsic capacity of hypoplastic fetal lungs to recover from hypoplasia and attenuated their daily branching rates. Although more exacerbated in CDH, both nitrofen-exposed lungs presented significant IL-6 mRNA and protein over-expression throughout all studied gestational ages. The present study suggests, for the first time, that fetal lung is able to recover from growth retardation through a way that resembles the catch-up growth phenomenon, and it seems to be, at least partially, orchestrated by intrinsic mechanisms implicating IL-6.

Hopf Bifurcation Analysis of a Gene Regulatory Network Mediated by Small Noncoding RNA with Time Delays and Diffusion

NASA Astrophysics Data System (ADS)

Li, Chengxian; Liu, Haihong; Zhang, Tonghua; Yan, Fang

2017-12-01

In this paper, a gene regulatory network mediated by small noncoding RNA involving two time delays and diffusion under the Neumann boundary conditions is studied. Choosing the sum of delays as the bifurcation parameter, the stability of the positive equilibrium and the existence of spatially homogeneous and spatially inhomogeneous periodic solutions are investigated by analyzing the corresponding characteristic equation. It is shown that the sum of delays can induce Hopf bifurcation and the diffusion incorporated into the system can effect the amplitude of periodic solutions. Furthermore, the spatially homogeneous periodic solution always exists and the spatially inhomogeneous periodic solution will arise when the diffusion coefficients of protein and mRNA are suitably small. Particularly, the small RNA diffusion coefficient is more robust and its effect on model is much less than protein and mRNA. Finally, the explicit formulae for determining the direction of Hopf bifurcation and the stability of the bifurcating periodic solutions are derived by employing the normal form theory and center manifold theorem for partial functional differential equations. Finally, numerical simulations are carried out to illustrate our theoretical analysis.

The Stilbenoid Tyrosine Kinase Inhibitor, G6, Suppresses Jak2-V617F-mediated Human Pathological Cell Growth in Vitro and in Vivo*

PubMed Central

Kirabo, Annet; Embury, Jennifer; Kiss, Róbert; Polgár, Tímea; Gali, Meghanath; Majumder, Anurima; Bisht, Kirpal S.; Cogle, Christopher R.; Keserű, György M.; Sayeski, Peter P.

2011-01-01

Using structure-based virtual screening, we previously identified a novel stilbenoid inhibitor of Jak2 tyrosine kinase named G6. Here, we hypothesized that G6 suppresses Jak2-V617F-mediated human pathological cell growth in vitro and in vivo. We found that G6 inhibited proliferation of the Jak2-V617F expressing human erythroleukemia (HEL) cell line by promoting marked cell cycle arrest and inducing apoptosis. The G6-dependent increase in apoptosis levels was concomitant with increased caspase 3/7 activity and cleavage of PARP. G6 also selectively inhibited phosphorylation of STAT5, a downstream signaling target of Jak2. Using a mouse model of Jak2-V617F-mediated hyperplasia, we found that G6 significantly decreased the percentage of blast cells in the peripheral blood, reduced splenomegaly, and corrected a pathologically low myeloid to erythroid ratio in the bone marrow by eliminating HEL cell engraftment in this tissue. In addition, drug efficacy correlated with the presence of G6 in the plasma, marrow, and spleen. Collectively, these data demonstrate that the stilbenoid compound, G6, suppresses Jak2-V617F-mediated aberrant cell growth. As such, G6 may be a potential therapeutic lead candidate against Jak2-mediated, human disease. PMID:21127060

[Regulatory T cells].

PubMed

Marinić, Igor; Gagro, Alenka; Rabatić, Sabina

2006-12-01

Regulatory T-cells are a subset of T cells that have beene extensively studied in modern immunology. They are important for the maintenance of peripheral tolerance, and have an important role in various clinical conditions such as allergy, autoimmune disorders, tumors, infections, and in transplant medicine. Basically, this population has a suppressive effect on the neighboring immune cells, thus contributing to the local modulation and control of immune response. There are two main populations of regulatory T cells - natural regulatory T cells, which form a distinct cellular lineage, develop in thymus and perform their modulatory action through direct intercellular contact, along with the secreted cytokines; and inducible regulatory T cells, which develop in the periphery after contact with the antigen that is presented on the antigen presenting cell, and their primary mode of action is through the interleukin 10 (IL-10) and transforming growth factor beta (TGF-alpha) cytokines. Natural regulatory T cells are activated through T cell receptor after contact with specific antigen and inhibit proliferation of other T cells in an antigen independent manner. One of the major difficulties in the research of regulatory T cells is the lack of specific molecular markers that would identify these cells. Natural regulatory T cells constitutively express surface molecule CD25, but many other surface and intracellular molecules (HLA-DR, CD122, CD45RO, CD62, CTLA-4, GITR, PD-1, Notch, FOXP3, etc.) are being investigated for further phenotypic characterization of these cells. Because regulatory T cells have an important role in establishing peripheral tolerance, their importance is manifested in a number of clinical conditions. In the IPEX syndrome (immunodysregulation, polyendocrinopathy and enteropathy, X-linked), which is caused by mutation in Foxp3 gene that influences the development and function of regulatory T cells, patients develop severe autoimmune reactions that

Water-Vapor-Mediated Close-Spaced Vapor Transport Growth of Epitaxial Gallium Indium Phosphide Films on Gallium Arsenide Substrates

DOE PAGES

Greenaway, Ann L.; Bachman, Benjamin F.; Boucher, Jason W.; ...

2018-01-12

Ga 1–xIn xP is a technologically important III–V ternary semiconductor widely utilized in commercial and record-efficiency solar cells. We report the growth of Ga 1–xIn xP by water-vapor-mediated close-spaced vapor transport. Because growth of III–V semiconductors in this system is controlled by diffusion of metal oxide species, we find that congruent transport from the mixed powder source requires complete annealing to form a single alloy phase. Growth from a fully alloyed source at water vapor concentrations of ~7000 ppm in H 2 at 850 °C affords smooth films with electron mobility of 1070 cm 2 V –1 s –1 andmore » peak internal quantum efficiency of ~90% for carrier collection in a nonaqueous photoelectrochemical test cell.« less

Water-Vapor-Mediated Close-Spaced Vapor Transport Growth of Epitaxial Gallium Indium Phosphide Films on Gallium Arsenide Substrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greenaway, Ann L.; Bachman, Benjamin F.; Boucher, Jason W.

Ga 1–xIn xP is a technologically important III–V ternary semiconductor widely utilized in commercial and record-efficiency solar cells. We report the growth of Ga 1–xIn xP by water-vapor-mediated close-spaced vapor transport. Because growth of III–V semiconductors in this system is controlled by diffusion of metal oxide species, we find that congruent transport from the mixed powder source requires complete annealing to form a single alloy phase. Growth from a fully alloyed source at water vapor concentrations of ~7000 ppm in H 2 at 850 °C affords smooth films with electron mobility of 1070 cm 2 V –1 s –1 andmore » peak internal quantum efficiency of ~90% for carrier collection in a nonaqueous photoelectrochemical test cell.« less

Mitogen-Inducible Gene-6 Mediates Feedback Inhibition from Mutated BRAF towards the Epidermal Growth Factor Receptor and Thereby Limits Malignant Transformation

PubMed Central

Milewska, Malgorzata; Romano, David; Herrero, Ana; Guerriero, Maria Luisa; Birtwistle, Marc; Quehenberger, Franz; Hatzl, Stefan; Kholodenko, Boris N.; Segatto, Oreste; Kolch, Walter; Zebisch, Armin

2015-01-01

BRAF functions in the RAS-extracellular signal-regulated kinase (ERK) signaling cascade. Activation of this pathway is necessary to mediate the transforming potential of oncogenic BRAF, however, it may also cause a negative feedback that inhibits the epidermal growth factor receptor (EGFR). Mitogen-inducible gene-6 (MIG-6) is a potent inhibitor of the EGFR and has been demonstrated to function as a tumor suppressor. As MIG-6 can be induced via RAS-ERK signaling, we investigated its potential involvement in this negative regulatory loop. Focus formation assays were performed and demonstrated that MIG-6 significantly reduces malignant transformation induced by oncogenic BRAF. Although this genetic interaction was mirrored by a physical interaction between MIG-6 and BRAF, we did not observe a direct regulation of BRAF kinase activity by MIG-6. Interestingly, a selective chemical EGFR inhibitor suppressed transformation to a similar degree as MIG-6, whereas combining these approaches had no synergistic effect. By analyzing a range of BRAF mutated and wildtype cell line models, we could show that BRAF V600E causes a strong upregulation of MIG-6, which was mediated at the transcriptional level via the RAS-ERK pathway and resulted in downregulation of EGFR activation. This feedback loop is operational in tumors, as shown by the analysis of almost 400 patients with papillary thyroid cancer (PTC). Presence of BRAF V600E correlated with increased MIG-6 expression on the one hand, and with inactivation of the EGFR and of PI3K/AKT signaling on the other hand. Importantly, we also observed a more aggressive disease phenotype when BRAF V600E coexisted with low MIG-6 expression. Finally, analysis of methylation data was performed and revealed that higher methylation of MIG-6 correlated to its decreased expression. Taken together, we demonstrate that MIG-6 efficiently reduces cellular transformation driven by oncogenic BRAF by orchestrating a negative feedback circuit directed

Hydroquinone induces TK6 cell growth arrest and apoptosis through PARP-1/p53 regulatory pathway.

PubMed

Luo, Hao; Liang, Hairong; Chen, Jiajia; Xu, Yongchun; Chen, Yuting; Xu, Longmei; Yun, Lin; Liu, Jiaxian; Yang, Hui; Liu, Linhua; Peng, Jianming; Liu, Zhidong; Tang, Lin; Chen, Wen; Tang, Huanwen

2017-09-01

Hydroquinone (HQ), one of the most important metabolites derived from benzene, induces cell cycle arrest and apoptosis. Poly(ADP-ribose) polymerase-1 (PARP-1) participates in various biological processes, including DNA repair and cell cycle regulation. To explore whether PARP-1 regulatory pathway mediated HQ-induced cell cycle arrest and apoptosis, we assessed the effect of PARP-1 suppression on induction of apoptosis analyzed by FACSCalibur flow cytometer in PARP-1 deficientTK6 cells (TK6-shPARP-1). We observed an increase in the fraction of cells in G1 phase by 7.6% and increased apoptosis by 4.5% in PARP-1-deficient TK6 cells (TK6-shPARP-1) compared to those negative control cells (TK6-shNC cells) in response to HQ treatment. Furthermore, HQ might activate the extrinsic pathways of apoptosis via up-regulation of Fas expression, followed by caspase-3 activation, apoptotic body, and sub G1 accumulation. Enhanced p53 expression was observed in TK6-shPARP-1 cells than in TK6-shNC cells after HQ treatment. In contrast, Fas expression was lower in TK6-shPARP-1 cells than in TK6-shNC cells. Therefore, we conclude that HQ may activate apoptotic signals via Fas up-regulation and p53-mediated apoptosis in TK6-shNC cells. The reduction of PARP-1 expression further intensified up-regulation of p53 in TK6-shPARP-1 cells, resulting in an increased G1→S phase cell arrest and apoptosis in TK6-shPARP-1 cells compared to TK6-shNC cells. © 2017 Wiley Periodicals, Inc.

Redox-mediated activation of latent transforming growth factor-beta 1

NASA Technical Reports Server (NTRS)

Barcellos-Hoff, M. H.; Dix, T. A.; Chatterjee, A. (Principal Investigator)

1996-01-01

Transforming growth factor beta 1 (TGF beta) is a multifunctional cytokine that orchestrates response to injury via ubiquitous cell surface receptors. The biological activity of TGF beta is restrained by its secretion as a latent complex (LTGF beta) such that activation determines the extent of TGF beta activity during physiological and pathological events. TGF beta action has been implicated in a variety of reactive oxygen-mediated tissue processes, particularly inflammation, and in pathologies such as reperfusion injury, rheumatoid arthritis, and atherosclerosis. It was recently shown to be rapidly activated after in vivo radiation exposure, which also generates reactive oxygen species (ROS). In the present studies, the potential for redox-mediated LTGF beta activation was investigated using a cell-free system in which ROS were generated in solution by ionizing radiation or metal ion-catalyzed ascorbate reaction. Irradiation (100 Gray) of recombinant human LTGF beta in solution induced 26% activation compared with that elicited by standard thermal activation. Metal-catalyzed ascorbate oxidation elicited extremely efficient recombinant LTGF beta activation that matched or exceeded thermal activation. The efficiency of ascorbate activation depended on ascorbate concentrations and the presence of transition metal ions. We postulate that oxidation of specific amino acids in the latency-conferring peptide leads to a conformation change in the latent complex that allows release of TGF beta. Oxidative activation offers a novel route for the involvement of TGF beta in tissue processes in which ROS are implicated and endows LTGF beta with the ability to act as a sensor of oxidative stress and, by releasing TGF beta, to function as a signal for orchestrating the response of multiple cell types. LTGF beta redox sensitivity is presumably directed toward recovery of homeostasis; however, oxidation may also be a mechanism of LTGF beta activation that can be deleterious during

The chemokine CXCL12 mediates the anti-amyloidogenic action of painless human nerve growth factor.

PubMed

Capsoni, Simona; Malerba, Francesca; Carucci, Nicola Maria; Rizzi, Caterina; Criscuolo, Chiara; Origlia, Nicola; Calvello, Mariantonietta; Viegi, Alessandro; Meli, Giovanni; Cattaneo, Antonino

2017-01-01

Nerve growth factor is a therapeutic candidate for Alzheimer's disease. Due to its pain-inducing activity, in current clinical trials nerve growth factor is delivered locally into the brain by neurosurgery, but data on the efficacy of local nerve growth factor delivery in decreasing amyloid-β deposition are not available. To reduce the nerve growth factor pain-inducing side effects, thus avoiding the need for local brain injection, we developed human painless nerve growth factor (hNGFp), inspired by the human genetic disease hereditary sensory and autonomic neuropathy type V. hNGFp has identical neurotrophic potency as wild-type human nerve growth factor, but a 10-fold lower pain sensitizing activity. In this study we first mimicked, in the 5xFAD mouse model, the intraparenchymal delivery of hNGFp used in clinical trials and found it to be ineffective in decreasing amyloid-β plaque load. On the contrary, the same dose of hNGFp delivered intranasally, which was widely biodistributed in the brain and did not induce pain, showed a potent anti-amyloidogenic action and rescued synaptic plasticity and memory deficits. We found that hNGFp acts on glial cells, modulating inflammatory proteins such as the soluble TNFα receptor II and the chemokine CXCL12. We further established that the rescuing effect by hNGFp is mediated by CXCL12, as pharmacological inhibition of CXCL12 receptor CXCR4 occludes most of hNGFp effects. These findings have significant therapeutic implications: (i) we established that a widespread exposure of the brain is required for nerve growth factor to fully exert its neuroprotective actions; and (ii) we have identified a new anti-neurodegenerative pathway as a broad target for new therapeutic opportunities for neurodegenerative diseases. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain.

c-MAF-dependent regulatory T cells mediate immunological tolerance to a gut pathobiont.

PubMed

Xu, Mo; Pokrovskii, Maria; Ding, Yi; Yi, Ren; Au, Christy; Harrison, Oliver J; Galan, Carolina; Belkaid, Yasmine; Bonneau, Richard; Littman, Dan R

2018-02-15

Both microbial and host genetic factors contribute to the pathogenesis of autoimmune diseases. There is accumulating evidence that microbial species that potentiate chronic inflammation, as in inflammatory bowel disease, often also colonize healthy individuals. These microorganisms, including the Helicobacter species, can induce pathogenic T cells and are collectively referred to as pathobionts. However, how such T cells are constrained in healthy individuals is not yet understood. Here we report that host tolerance to a potentially pathogenic bacterium, Helicobacter hepaticus, is mediated by the induction of RORγt + FOXP3 + regulatory T (iT reg ) cells that selectively restrain pro-inflammatory T helper 17 (T H 17) cells and whose function is dependent on the transcription factor c-MAF. Whereas colonization of wild-type mice by H. hepaticus promoted differentiation of RORγt-expressing microorganism-specific iT reg cells in the large intestine, in disease-susceptible IL-10-deficient mice, there was instead expansion of colitogenic T H 17 cells. Inactivation of c-MAF in the T reg cell compartment impaired differentiation and function, including IL-10 production, of bacteria-specific iT reg cells, and resulted in the accumulation of H. hepaticus-specific inflammatory T H 17 cells and spontaneous colitis. By contrast, RORγt inactivation in T reg cells had only a minor effect on the bacteria-specific T reg and T H 17 cell balance, and did not result in inflammation. Our results suggest that pathobiont-dependent inflammatory bowel disease is driven by microbiota-reactive T cells that have escaped this c-MAF-dependent mechanism of iT reg -T H 17 homeostasis.

CD4+CD25+ regulatory T cells suppress allograft rejection mediated by memory CD8+ T cells via a CD30-dependent mechanism.

PubMed

Dai, Zhenhua; Li, Qi; Wang, Yinong; Gao, Ge; Diggs, Lonnette S; Tellides, George; Lakkis, Fadi G

2004-01-01

CD4(+)CD25(+) regulatory T (Treg) cells suppress naive T cell responses, prevent autoimmunity, and delay allograft rejection. It is not known, however, whether Treg cells suppress allograft rejection mediated by memory T cells, as the latter mount faster and stronger immune responses than their naive counterparts. Here we show that antigen-induced, but not naive, Treg cells suppress allograft rejection mediated by memory CD8(+) T cells. Suppression was allospecific, as Treg cells induced by third-party antigens did not delay allograft rejection. In vivo and in vitro analyses revealed that the apoptosis of allospecific memory CD8(+) T cells is significantly increased in the presence of antigen-induced Treg cells, while their proliferation remains unaffected. Importantly, neither suppression of allograft rejection nor enhanced apoptosis of memory CD8(+) T cells was observed when Treg cells lacked CD30 or when CD30 ligand-CD30 interaction was blocked with anti-CD30 ligand Ab. This study therefore provides direct evidence that pathogenic memory T cells are amenable to suppression in an antigen-specific manner and identifies CD30 as a molecule that is critical for the regulation of memory T cell responses.

CD4+CD25+ regulatory T cells suppress allograft rejection mediated by memory CD8+ T cells via a CD30-dependent mechanism

PubMed Central

Dai, Zhenhua; Li, Qi; Wang, Yinong; Gao, Ge; Diggs, Lonnette S.; Tellides, George; Lakkis, Fadi G.

2004-01-01

CD4+CD25+ regulatory T (Treg) cells suppress naive T cell responses, prevent autoimmunity, and delay allograft rejection. It is not known, however, whether Treg cells suppress allograft rejection mediated by memory T cells, as the latter mount faster and stronger immune responses than their naive counterparts. Here we show that antigen-induced, but not naive, Treg cells suppress allograft rejection mediated by memory CD8+ T cells. Suppression was allospecific, as Treg cells induced by third-party antigens did not delay allograft rejection. In vivo and in vitro analyses revealed that the apoptosis of allospecific memory CD8+ T cells is significantly increased in the presence of antigen-induced Treg cells, while their proliferation remains unaffected. Importantly, neither suppression of allograft rejection nor enhanced apoptosis of memory CD8+ T cells was observed when Treg cells lacked CD30 or when CD30 ligand–CD30 interaction was blocked with anti–CD30 ligand Ab. This study therefore provides direct evidence that pathogenic memory T cells are amenable to suppression in an antigen-specific manner and identifies CD30 as a molecule that is critical for the regulation of memory T cell responses. PMID:14722622

miRNA and mRNA Expression Profiles Reveal Insight into Chitosan-Mediated Regulation of Plant Growth.

PubMed

Zhang, Xiaoqian; Li, Kecheng; Xing, Ronge; Liu, Song; Chen, Xiaolin; Yang, Haoyue; Li, Pengcheng

2018-04-18

Chitosan has been numerously studied as a plant growth regulator and stress tolerance inducer. To investigate the roles of chitosan as bioregulator on plant and unravel its possible metabolic responses mechanisms, we simultaneously investigated mRNAs and microRNAs (miRNAs) expression profiles of wheat seedlings in response to chitosan heptamer. We found 400 chitosan-responsive differentially expressed genes, including 268 up-regulated and 132 down-regulated mRNAs, many of which were related to photosynthesis, primary carbon and nitrogen metabolism, defense responses, and transcription factors. Moreover, miRNAs also participate in chitosan-mediated regulation on plant growth. We identified 87 known and 21 novel miRNAs, among which 56 miRNAs were induced or repressed by chitosan heptamer, such as miRNA156, miRNA159a, miRNA164, miRNA171a, miRNA319, and miRNA1127. The integrative analysis of miRNA and mRNA expression profiles in this case provides fundamental information for further investigation of regulation mechanisms of chitosan on plant growth and will facilitate its application in agriculture.

Detection of neurotransmitters by a light scattering technique based on seed-mediated growth of gold nanoparticles

NASA Astrophysics Data System (ADS)

Shang, Li; Dong, Shaojun

2008-03-01

A simple light scattering detection method for neurotransmitters has been developed, based on the growth of gold nanoparticles. Neurotransmitters (dopamine, L-dopa, noradrenaline and adrenaline) can effectively function as active reducing agents for generating gold nanoparticles, which result in enhanced light scattering signals. The strong light scattering of gold nanoparticles then allows the quantitative detection of the neurotransmitters simply by using a common spectrofluorometer. In particular, Au-nanoparticle seeds were added to facilitate the growth of nanoparticles, which was found to enhance the sensing performance greatly. Using this light scattering technique based on the seed-mediated growth of gold nanoparticles, detection limits of 4.4 × 10-7 M, 3.5 × 10-7 M, 4.1 × 10-7 M, and 7.7 × 10-7 M were achieved for dopamine, L-dopa, noradrenaline and adrenaline, respectively. The present strategy can be extended to detect other biologically important molecules in a very fast, simple and sensitive way, and may have potential applications in a wide range of fields.

Shoot bending promotes flower bud formation by miRNA-mediated regulation in apple (Malus domestica Borkh.).

PubMed

Xing, Libo; Zhang, Dong; Zhao, Caiping; Li, Youmei; Ma, Juanjuan; An, Na; Han, Mingyu

2016-02-01

Flower induction in apple (Malus domestica Borkh.) trees plays an important life cycle role, but young trees produce fewer and inferior quality flower buds. Therefore, shoot bending has become an important cultural practice, significantly promoting the capacity to develop more flower buds during the growing seasons. Additionally, microRNAs (miRNAs) play essential roles in plant growth, flower induction and stress responses. In this study, we identified miRNAs potentially involved in the regulation of bud growth, and flower induction and development, as well as in the response to shoot bending. Of the 195 miRNAs identified, 137 were novel miRNAs. The miRNA expression profiles revealed that the expression levels of 68 and 27 known miRNAs were down-regulated and up-regulated, respectively, in response to shoot bending, and that the 31 differentially expressed novel miRNAs between them formed five major clusters. Additionally, a complex regulatory network associated with auxin, cytokinin, abscisic acid (ABA) and gibberellic acid (GA) plays important roles in cell division, bud growth and flower induction, in which related miRNAs and targets mediated regulation. Among them, miR396, 160, 393, and their targets associated with AUX, miR159, 319, 164, and their targets associated with ABA and GA, and flowering-related miRNAs and genes, regulate bud growth and flower bud formation in response to shoot bending. Meanwhile, the flowering genes had significantly higher expression levels during shoot bending, suggesting that they are involved in this regulatory process. This study provides a framework for the future analysis of miRNAs associated with multiple hormones and their roles in the regulation of bud growth, and flower induction and formation in response to shoot bending in apple trees. © 2015 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

The Mediator Complex and Lipid Metabolism.

PubMed

Zhang, Yi; Xiaoli; Zhao, Xiaoping; Yang, Fajun

2013-03-01

The precise control of gene expression is essential for all biological processes. In addition to DNA-binding transcription factors, numerous transcription cofactors contribute another layer of regulation of gene transcription in eukaryotic cells. One of such transcription cofactors is the highly conserved Mediator complex, which has multiple subunits and is involved in various biological processes through directly interacting with relevant transcription factors. Although the current understanding on the biological functions of Mediator remains incomplete, research in the past decade has revealed an important role of Mediator in regulating lipid metabolism. Such function of Mediator is dependent on specific transcription factors, including peroxisome proliferator-activated receptor-gamma (PPARγ) and sterol regulatory element-binding proteins (SREBPs), which represent the master regulators of lipid metabolism. The medical significance of these findings is apparent, as aberrant lipid metabolism is intimately linked to major human diseases, such as type 2 diabetes and cardiovascular disease. Here, we briefly review the functions and molecular mechanisms of Mediator in regulation of lipid metabolism.

Immune-Regulatory Molecule CD69 Controls Peritoneal Fibrosis

PubMed Central

Liappas, Georgios; González-Mateo, Guadalupe Tirma; Sánchez-Díaz, Raquel; Lazcano, Juan José; Lasarte, Sandra; Matesanz-Marín, Adela; Zur, Rafal; Ferrantelli, Evelina; Ramírez, Laura García; Aguilera, Abelardo; Fernández-Ruiz, Elena; Beelen, Robert H.J.; Selgas, Rafael; Sánchez-Madrid, Francisco

2016-01-01

Patients with ESRD undergoing peritoneal dialysis develop progressive peritoneal fibrosis, which may lead to technique failure. Recent data point to Th17-mediated inflammation as a key contributor in peritoneal damage. The leukocyte antigen CD69 modulates the setting and progression of autoimmune and inflammatory diseases by controlling the balance between Th17 and regulatory T cells (Tregs). However, the relevance of CD69 in tissue fibrosis remains largely unknown. Thus, we explored the role of CD69 in fibroproliferative responses using a mouse model of peritoneal fibrosis induced by dialysis fluid exposure under either normal or uremic status. We found that cd69−/− mice compared with wild-type (WT) mice showed enhanced fibrosis, mesothelial to mesenchymal transition, IL-17 production, and Th17 cell infiltration in response to dialysis fluid treatment. Uremia contributed partially to peritoneal inflammatory and fibrotic responses. Additionally, antibody–mediated CD69 blockade in WT mice mimicked the fibrotic response of cd69−/− mice. Finally, IL-17 blockade in cd69−/− mice decreased peritoneal fibrosis to the WT levels, and mixed bone marrow from cd69−/− and Rag2−/−γc−/− mice transplanted into WT mice reproduced the severity of the response to dialysis fluid observed in cd69−/− mice, showing that CD69 exerts its regulatory function within the lymphocyte compartment. Overall, our results indicate that CD69 controls tissue fibrosis by regulating Th17-mediated inflammation. PMID:27151919

Nutritionally mediated programming of the developing immune system.

PubMed

Palmer, Amanda C

2011-09-01

A growing body of evidence highlights the importance of a mother's nutrition from preconception through lactation in programming the emerging organ systems and homeostatic pathways of her offspring. The developing immune system may be particularly vulnerable. Indeed, examples of nutrition-mediated immune programming can be found in the literature on intra-uterine growth retardation, maternal micronutrient deficiencies, and infant feeding. Current models of immune ontogeny depict a "layered" expansion of increasingly complex defenses, which may be permanently altered by maternal malnutrition. One programming mechanism involves activation of the maternal hypothalamic-pituitary-adrenal axis in response to nutritional stress. Fetal or neonatal exposure to elevated stress hormones is linked in animal studies to permanent changes in neuroendocrine-immune interactions, with diverse manifestations such as an attenuated inflammatory response or reduced resistance to tumor colonization. Maternal malnutrition may also have a direct influence, as evidenced by nutrient-driven epigenetic changes to developing T regulatory cells and subsequent risk of allergy or asthma. A 3rd programming pathway involves placental or breast milk transfer of maternal immune factors with immunomodulatory functions (e.g. cytokines). Maternal malnutrition can directly affect transfer mechanisms or influence the quality or quantity of transferred factors. The public health implications of nutrition-mediated immune programming are of particular importance in the developing world, where prevalent maternal undernutrition is coupled with persistent infectious challenges. However, early alterations to the immune system, resulting from either nutritional deficiencies or excesses, have broad relevance for immune-mediated diseases, such as asthma, and chronic inflammatory conditions like cardiovascular disease.

Zcchc11 Uridylates Mature miRNAs to Enhance Neonatal IGF-1 Expression, Growth, and Survival

PubMed Central

Kozlowski, Elyse; Matsuura, Kori Y.; Ferrari, Joseph D.; Morris, Samantha A.; Powers, John T.; Daley, George Q.; Quinton, Lee J.; Mizgerd, Joseph P.

2012-01-01

The Zcchc11 enzyme is implicated in microRNA (miRNA) regulation. It can uridylate let-7 precursors to decrease quantities of the mature miRNA in embryonic stem cell lines, suggested to mediate stem cell maintenance. It can uridylate mature miR-26 to relieve silencing activity without impacting miRNA content in cancer cell lines, suggested to mediate cytokine and growth factor expression. Broader roles of Zcchc11 in shaping or remodeling the miRNome or in directing biological or physiological processes remain entirely speculative. We generated Zcchc11-deficient mice to address these knowledge gaps. Zcchc11 deficiency had no impact on embryogenesis or fetal development, but it significantly decreased survival and growth immediately following birth, indicating a role for this enzyme in early postnatal fitness. Deep sequencing of small RNAs from neonatal livers revealed roles of this enzyme in miRNA sequence diversity. Zcchc11 deficiency diminished the lengths and terminal uridine frequencies for diverse mature miRNAs, but it had no influence on the quantities of any miRNAs. The expression of IGF-1, a liver-derived protein essential to early growth and survival, was enhanced by Zcchc11 expression in vitro, and miRNA silencing of IGF-1 was alleviated by uridylation events observed to be Zcchc11-dependent in the neonatal liver. In neonatal mice, Zcchc11 deficiency significantly decreased IGF-1 mRNA in the liver and IGF-1 protein in the blood. We conclude that the Zcchc11-mediated terminal uridylation of mature miRNAs is pervasive and physiologically significant, especially important in the neonatal period for fostering IGF-1 expression and enhancing postnatal growth and survival. We propose that the miRNA 3′ terminus is a regulatory node upon which multiple enzymes converge to direct silencing activity and tune gene expression. PMID:23209448

Cellular uptake mediated by epidermal growth factor receptor facilitates the intracellular activity of phosphorothioate-modified antisense oligonucleotides

PubMed Central

Wang, Shiyu; Allen, Nickolas; Vickers, Timothy A; Revenko, Alexey S; Sun, Hong; Liang, Xue-hai; Crooke, Stanley T

2018-01-01

Abstract Chemically modified antisense oligonucleotides (ASOs) with phosphorothioate (PS) linkages have been extensively studied as research and therapeutic agents. PS-ASOs can enter the cell and trigger cleavage of complementary RNA by RNase H1 even in the absence of transfection reagent. A number of cell surface proteins have been identified that bind PS-ASOs and mediate their cellular uptake; however, the mechanisms that lead to productive internalization of PS-ASOs are not well understood. Here, we characterized the interaction between PS-ASOs and epidermal growth factor receptor (EGFR). We found that PS-ASOs trafficked together with EGF and EGFR into clathrin-coated pit structures. Their co-localization was also observed at early endosomes and inside enlarged late endosomes. Reduction of EGFR decreased PS-ASO activity without affecting EGF-mediated signaling pathways and overexpression of EGFR increased PS-ASO activity in cells. Furthermore, reduction of EGFR delays PS-ASO trafficking from early to late endosomes. Thus, EGFR binds to PS-ASOs at the cell surface and mediates essential steps for active (productive) cellular uptake of PS-ASOs through its cargo-dependent trafficking processes which migrate PS-ASOs from early to late endosomes. This EGFR-mediated process can also serve as an additional model to better understand the mechanism of intracellular uptake and endosomal release of PS-ASOs. PMID:29514240

Stoichiometric Mismatch between Consumers and Resources Mediates the Growth of Rocky Intertidal Suspension Feeders

PubMed Central

Bracken, Matthew E. S.

2017-01-01

stoichiometry as a mediator of consumer-resource interactions in rocky intertidal communities. I show that resource quality and quantity interact to determine consumer growth, highlighting the utility of ecological stoichiometry in understanding spatial subsidies in benthic marine systems. PMID:28747903

Radical-Mediated Enzymatic Polymerizations

PubMed Central

Zavada, Scott R.; Battsengel, Tsatsral; Scott, Timothy F.

2016-01-01

Polymerization reactions are commonly effected by exposing monomer formulations to some initiation stimulus such as elevated temperature, light, or a chemical reactant. Increasingly, these polymerization reactions are mediated by enzymes―catalytic proteins―owing to their reaction efficiency under mild conditions as well as their environmental friendliness. The utilization of enzymes, particularly oxidases and peroxidases, for generating radicals via reduction-oxidation mechanisms is especially common for initiating radical-mediated polymerization reactions, including vinyl chain-growth polymerization, atom transfer radical polymerization, thiol–ene step-growth polymerization, and polymerization via oxidative coupling. While enzyme-mediated polymerization is useful for the production of materials intended for subsequent use, it is especially well-suited for in situ polymerizations, where the polymer is formed in the place where it will be utilized. Such polymerizations are especially useful for biomedical adhesives and for sensing applications. PMID:26848652

Optimal bioprocess design through a gene regulatory network - growth kinetic hybrid model: Towards Replacing Monod kinetics.

PubMed

Tsipa, Argyro; Koutinas, Michalis; Usaku, Chonlatep; Mantalaris, Athanasios

2018-05-02

Currently, design and optimisation of biotechnological bioprocesses is performed either through exhaustive experimentation and/or with the use of empirical, unstructured growth kinetics models. Whereas, elaborate systems biology approaches have been recently explored, mixed-substrate utilisation is predominantly ignored despite its significance in enhancing bioprocess performance. Herein, bioprocess optimisation for an industrially-relevant bioremediation process involving a mixture of highly toxic substrates, m-xylene and toluene, was achieved through application of a novel experimental-modelling gene regulatory network - growth kinetic (GRN-GK) hybrid framework. The GRN model described the TOL and ortho-cleavage pathways in Pseudomonas putida mt-2 and captured the transcriptional kinetics expression patterns of the promoters. The GRN model informed the formulation of the growth kinetics model replacing the empirical and unstructured Monod kinetics. The GRN-GK framework's predictive capability and potential as a systematic optimal bioprocess design tool, was demonstrated by effectively predicting bioprocess performance, which was in agreement with experimental values, when compared to four commonly used models that deviated significantly from the experimental values. Significantly, a fed-batch biodegradation process was designed and optimised through the model-based control of TOL Pr promoter expression resulting in 61% and 60% enhanced pollutant removal and biomass formation, respectively, compared to the batch process. This provides strong evidence of model-based bioprocess optimisation at the gene level, rendering the GRN-GK framework as a novel and applicable approach to optimal bioprocess design. Finally, model analysis using global sensitivity analysis (GSA) suggests an alternative, systematic approach for model-driven strain modification for synthetic biology and metabolic engineering applications. Copyright © 2018. Published by Elsevier Inc.

Combining inferred regulatory and reconstructed metabolic networks enhances phenotype prediction in yeast.

PubMed

Wang, Zhuo; Danziger, Samuel A; Heavner, Benjamin D; Ma, Shuyi; Smith, Jennifer J; Li, Song; Herricks, Thurston; Simeonidis, Evangelos; Baliga, Nitin S; Aitchison, John D; Price, Nathan D

2017-05-01

Gene regulatory and metabolic network models have been used successfully in many organisms, but inherent differences between them make networks difficult to integrate. Probabilistic Regulation Of Metabolism (PROM) provides a partial solution, but it does not incorporate network inference and underperforms in eukaryotes. We present an Integrated Deduced And Metabolism (IDREAM) method that combines statistically inferred Environment and Gene Regulatory Influence Network (EGRIN) models with the PROM framework to create enhanced metabolic-regulatory network models. We used IDREAM to predict phenotypes and genetic interactions between transcription factors and genes encoding metabolic activities in the eukaryote, Saccharomyces cerevisiae. IDREAM models contain many fewer interactions than PROM and yet produce significantly more accurate growth predictions. IDREAM consistently outperformed PROM using any of three popular yeast metabolic models and across three experimental growth conditions. Importantly, IDREAM's enhanced accuracy makes it possible to identify subtle synthetic growth defects. With experimental validation, these novel genetic interactions involving the pyruvate dehydrogenase complex suggested a new role for fatty acid-responsive factor Oaf1 in regulating acetyl-CoA production in glucose grown cells.

Transcription regulation by the Mediator complex.

PubMed

Soutourina, Julie

2018-04-01

Alterations in the regulation of gene expression are frequently associated with developmental diseases or cancer. Transcription activation is a key phenomenon in the regulation of gene expression. In all eukaryotes, mediator of RNA polymerase II transcription (Mediator), a large complex with modular organization, is generally required for transcription by RNA polymerase II, and it regulates various steps of this process. The main function of Mediator is to transduce signals from the transcription activators bound to enhancer regions to the transcription machinery, which is assembled at promoters as the preinitiation complex (PIC) to control transcription initiation. Recent functional studies of Mediator with the use of structural biology approaches and functional genomics have revealed new insights into Mediator activity and its regulation during transcription initiation, including how Mediator is recruited to transcription regulatory regions and how it interacts and cooperates with PIC components to assist in PIC assembly. Novel roles of Mediator in the control of gene expression have also been revealed by showing its connection to the nuclear pore and linking Mediator to the regulation of gene positioning in the nuclear space. Clear links between Mediator subunits and disease have also encouraged studies to explore targeting of this complex as a potential therapeutic approach in cancer and fungal infections.

Parasite-mediated nuclear factor κB regulation in lymphoproliferation caused by Theileria parva infection

PubMed Central

Palmer, Guy H.; Machado, Joel; Fernandez, Paula; Heussler, Volker; Perinat, Therese; Dobbelaere, Dirk A. E.

1997-01-01

Infection of cattle with the protozoan Theileria parva results in uncontrolled T lymphocyte proliferation resulting in lesions resembling multicentric lymphoma. Parasitized cells exhibit autocrine growth characterized by persistent translocation of the transcriptional regulatory factor nuclear factor κB (NFκB) to the nucleus and consequent enhanced expression of interleukin 2 and the interleukin 2 receptor. How T. parva induces persistent NFκB activation, required for T cell activation and proliferation, is unknown. We hypothesized that the parasite induces degradation of the IκB molecules which normally sequester NFκB in the cytoplasm and that continuous degradation requires viable parasites. Using T. parva-infected T cells, we showed that the parasite mediates continuous phosphorylation and proteolysis of IκBα. However, IκBα reaccumulated to high levels in parasitized cells, which indicated that T. parva did not alter the normal NFκB-mediated positive feedback loop which restores cytoplasmic IκBα. In contrast, T. parva mediated continuous degradation of IκBβ resulting in persistently low cytoplasmic IκBβ levels. Normal IκBβ levels were only restored following T. parva killing, indicating that viable parasites are required for IκBβ degradation. Treatment of T. parva-infected cells with pyrrolidine dithiocarbamate, a metal chelator, blocked both IκB degradation and consequent enhanced expression of NFκB dependent genes. However treatment using the antioxidant N-acetylcysteine had no effect on either IκB levels or NFκB activation, indicating that the parasite subverts the normal IκB regulatory pathway downstream of the requirement for reactive oxygen intermediates. Identification of the critical points regulated by T. parva may provide new approaches for disease control as well as increase our understanding of normal T cell function. PMID:9356483

N-methyl-N'-nitro-N-nitrosoguanidine interferes with the epidermal growth factor receptor-mediated signaling pathway.

PubMed

Gao, Zhihua; Yang, Jun; Huang, Yun; Yu, Yingnian

2005-03-01

Many environmental factors, such as ultraviolet (UV) and arsenic, can induce the clustering of cell surface receptors, including epidermal growth factor receptor (EGFR). This is accompanied by the phosphorylation of the receptors and the activation of ensuing cellular signal transduction pathways, which are implicated in the various cellular responses caused by the exposure to these factors. In this study, we have shown that N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), an alkylating agent, also induced the clustering of EGFR in human amnion FL cells, which was similar in morphology to that of epidermal growth factor treatment. However, MNNG treatment did not activate Ras, the downstream mediator in EGFR signaling pathway, as compared to EGF treatment. The autophosphorylation of tyrosine residues Y1068 and Y1173 at the intracellular domain of EGFR, which is related to Ras activation under EGF treatment, was also not observed by MNNG exposure. Interestingly, although MNNG did not affect the binding of EGF to EGFR, MNNG can interfere with EGF function. For instance, pre-incubating FL cells with MNNG inhibited the autophosphorylation of EGFR by EGF treatment, as well as the activation of Ras. In addition, the phosphorylation of Y845 on EGFR by EGF, which is mediated through c-Src or related kinases but not autophosphorylation, was also affected by MNNG. Therefore, MNNG may influence the tyrosine kinase activity as well as the phosphorylation of EGFR through its interaction with EGFR.

The role of regulatory T cells in the control of natural killer cells: relevance during tumor progression.

PubMed

Ghiringhelli, Francois; Ménard, Cédric; Martin, Francois; Zitvogel, Laurence

2006-12-01

Tumor immunosurveillance relies on cognate immune effectors [lymphocytes and interferon-gamma (IFN-gamma)] and innate immunity [natural killer (NK) cells, natural killer group 2, member D (NKG2D) ligands, perforin/granzyme, and tumor necrosis factor-related apoptosis-inducing ligand]. In parallel, tumor cells promote the expansion of CD4(+)CD25(+) regulatory T cells (Tregs) that counteract T-cell-based anti-tumor immunity. Moreover, accumulating evidence points to a critical role for Tregs in dampening NK cell immune responses. This review summarizes the findings showing that Tregs suppress NK cell effector functions in vitro and in vivo, i.e. homeostatic proliferation, cytotoxicity, and interleukin-12-mediated IFN-gamma production. The molecular mechanism involve selective expression of membrane-bound transforming growth factor-beta on Tregs, which downregulate NKG2D expression on NK cells in vitro and in vivo. The regulatory events dictating NK cell suppression by Tregs have been studied and are discussed. The pathological relevance of the Treg-NK cell interaction has been brought up in tumor models and in patients with cancer. Consequently, inhibition of Tregs through pharmacological interventions should be considered during NK-cell-based immunotherapy of cancer.

Drosophila Big bang regulates the apical cytocortex and wing growth through junctional tension.

PubMed

Tsoumpekos, Giorgos; Nemetschke, Linda; Knust, Elisabeth

2018-03-05

Growth of epithelial tissues is regulated by a plethora of components, including signaling and scaffolding proteins, but also by junctional tension, mediated by the actomyosin cytoskeleton. However, how these players are spatially organized and functionally coordinated is not well understood. Here, we identify the Drosophila melanogaster scaffolding protein Big bang as a novel regulator of growth in epithelial cells of the wing disc by ensuring proper junctional tension. Loss of big bang results in the reduction of the regulatory light chain of nonmuscle myosin, Spaghetti squash. This is associated with an increased apical cell surface, decreased junctional tension, and smaller wings. Strikingly, these phenotypic traits of big bang mutant discs can be rescued by expressing constitutively active Spaghetti squash. Big bang colocalizes with Spaghetti squash in the apical cytocortex and is found in the same protein complex. These results suggest that in epithelial cells of developing wings, the scaffolding protein Big bang controls apical cytocortex organization, which is important for regulating cell shape and tissue growth. © 2018 Tsoumpekos et al.

Current status of herbal product: Regulatory overview

PubMed Central

Sharma, Sanjay

2015-01-01

A review of the regulatory status of herbal drugs/products was done for few countries forming part of Asia, Africa, America, Europe, and Australia, to understand various categories under which the trade of herbal products is permitted and their premarketing requirements. A critical assessment was done, to know the hindrances in the process of harmonization of herbal products. It has been found that there is a lack of harmonization in the regulatory requirements of herbal products internationally, besides the issues of availability of herbs and their conservation. These are hindering the international trade and growth of the herbal products segment. PMID:26681886

Current status of herbal product: Regulatory overview.

PubMed

Sharma, Sanjay

2015-01-01

A review of the regulatory status of herbal drugs/products was done for few countries forming part of Asia, Africa, America, Europe, and Australia, to understand various categories under which the trade of herbal products is permitted and their premarketing requirements. A critical assessment was done, to know the hindrances in the process of harmonization of herbal products. It has been found that there is a lack of harmonization in the regulatory requirements of herbal products internationally, besides the issues of availability of herbs and their conservation. These are hindering the international trade and growth of the herbal products segment.

HSV-mediated gene transfer of vascular endothelial growth factor to dorsal root ganglia prevents diabetic neuropathy

PubMed Central

Chattopadhyay, M; Krisky, D; Wolfe, D; Glorioso, JC; Mata, M; Fink, DJ

2005-01-01

We examined the utility of herpes simplex virus (HSV) vector-mediated gene transfer of vascular endothelial growth factor (VEGF) in a mouse model of diabetic neuropathy. A replication-incompetent HSV vector with VEGF under the control of the HSV ICP0 promoter (vector T0VEGF) was constructed. T0VEGF expressed and released VEGF from primary dorsal root ganglion (DRG) neurons in vitro, and following subcutaneous inoculation in the foot, expressed VEGF in DRG and nerve in vivo. At 2 weeks after induction of diabetes, subcutaneous inoculation of T0VEGF prevented the reduction in sensory nerve amplitude characteristic of diabetic neuropathy measured 4 weeks later, preserved autonomic function measured by pilocarpine-induced sweating, and prevented the loss of nerve fibers in the skin and reduction of neuropeptide calcitonin gene-related peptide and substance P in DRG neurons of the diabetic mice. HSV-mediated transfer of VEGF to DRG may prove useful in treatment of diabetic neuropathy. PMID:15843809

Cloning and analysis of the positively acting regulatory gene amdR from Aspergillus nidulans.

PubMed Central

Andrianopoulos, A; Hynes, M J

1988-01-01

The positively acting regulatory gene amdR of Aspergillus nidulans coordinately regulates the expression of four unlinked structural genes involved in acetamide (amdS), omega amino acid (gatA and gabA), and lactam (lamA) catabolism. By the use of DNA-mediated transformation of A. nidulans, the amdR regulatory gene was cloned from a genomic cosmid library. Southern blot analysis of DNA from various loss-of-function amdR mutants revealed the presence of four detectable DNA rearrangements, including a deletion, an insertion, and a translocation. No detectable DNA rearrangements were found in several constitutive amdRc mutants. Analysis of the fate of amdR-bearing plasmids in transformants showed that 10 to 20% of the transformation events were homologous integrations or gene conversions, and this phenomenon was exploited in developing a strategy by which amdRc and amdR- alleles can be readily cloned and analyzed. Examination of the transcription of amdR by Northern blot (RNA blot) analysis revealed the presence of two mRNAs (2.7 and 1.8 kilobases) which were constitutively synthesized at a very low level. In addition, amdR transcription did not appear to depend on the presence of a functional amdR product nor was it altered in amdRc mutants. The dosage effects of multiple copies of amdR in transformants were examined, and it was shown that such transformants exhibited stronger growth than did the wild type on acetamide and pyrrolidinone media, indicating increased expression of the amdS and lamA genes, respectively. These results were used to formulate a model for amdR-mediated regulation of gene expression in which the low constitutive level of amdR product sets the upper limits of basal and induced transcription of the structural genes. Multiple copies of 5' sequences from the amdS gene can result in reduced growth on substrates whose utilization is dependent on amdR-controlled genes. This has been attributed to titration of limiting amdR gene product. Strong

Generation and function of immunosuppressive human and murine CD8+ T cells by transforming growth factor-β and retinoic acid

PubMed Central

Fleissner, Diana; Frede, Annika; Knott, Markus; Knuschke, Torben; Geffers, Robert; Hansen, Wiebke; Dobos, Gustav; Langhorst, Jost; Buer, Jan; Westendorf, Astrid M

2011-01-01

The intestinal immune system is constantly challenged by foreign antigens and commensal bacteria. Therefore, proper control of the intestinal microenvironment is required. One important arm of this regulatory network consists of regulatory T cells. In contrast to CD4+ Foxp3+ regulatory T cells, which have been well characterized, immunomodulatory CD8+ T cells that express Foxp3 are less well defined in terms of their generation and function. Failures of these regulatory mechanisms contribute to the development of inflammatory bowel disease. In this study we demonstrate that the frequency of CD8+ Foxp3+ T cells is reduced in the peripheral blood of patients with ulcerative colitis. As these cells might play a currently underestimated role in the maintenance of intestinal homeostasis, we have investigated human and murine CD8+ Foxp3+ T cells generated by stimulating naive CD8+ T cells in the presence of transforming growth factor-β and retinoic acid, mediators that are abundantly produced in the intestinal mucosa. These CD8+ Foxp3+ fully competent regulatory T cells show strong expression of regulatory molecules CD25, Gpr83 and CTLA-4 and exhibit cell–cell contact-dependent immunosuppressive activity in vitro. Our study illustrates a previously unappreciated critical role of CD8+ Foxp3+ T cells in controlling potentially dangerous T cells and in the maintenance of intestinal homeostasis. PMID:21711349

Exacerbation of spontaneous autoimmune nephritis following regulatory T cell depletion in B cell lymphoma 2-interacting mediator knock-out mice.

PubMed

Wang, Y M; Zhang, G Y; Wang, Y; Hu, M; Zhou, J J; Sawyer, A; Cao, Q; Wang, Y; Zheng, G; Lee, V W S; Harris, D C H; Alexander, S I

2017-05-01

Regulatory T cells (T regs ) have been recognized as central mediators for maintaining peripheral tolerance and limiting autoimmune diseases. The loss of T regs or their function has been associated with exacerbation of autoimmune disease. However, the temporary loss of T regs in the chronic spontaneous disease model has not been investigated. In this study, we evaluated the role of T regs in a novel chronic spontaneous glomerulonephritis model of B cell lymphoma 2-interacting mediator (Bim) knock-out mice by transient depleting T regs . Bim is a pro-apoptotic member of the B cell lymphoma 2 (Bcl-2) family. Bim knock-out (Bim -/- ) mice fail to delete autoreactive T cells in thymus, leading to chronic spontaneous autoimmune kidney disease. We found that T reg depletion in Bim -/- mice exacerbated the kidney injury with increased proteinuria, impaired kidney function, weight loss and greater histological injury compared with wild-type mice. There was a significant increase in interstitial infiltrate of inflammatory cells, antibody deposition and tubular damage. Furthermore, the serum levels of cytokines interleukin (IL)-2, IL-4, IL-6, IL-10, IL-17α, interferon (IFN)-γ and tumour necrosis factor (TNF)-α were increased significantly after T reg depletion in Bim -/- mice. This study demonstrates that transient depletion of T regs leads to enhanced self-reactive T effector cell function followed by exacerbation of kidney disease in the chronic spontaneous kidney disease model of Bim-deficient mice. © 2017 British Society for Immunology.

Cross-regulatory circuit between AHR and microbiota.

PubMed

Ji, Jian; Qu, Hao

2018-01-29

The gut microbes have a close symbiotic relationship with their host. Interactions between host and the microbiota affect the nutritional, immunological, and physiological status of the host. The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor that mediates the toxicity of xenobiotics. Recently, the relationship between the gut microbiota and AHR has attracted the attention of many researchers. The AHR influences the intestinal microbiota population and mediates host-microbe homeostasis. Interestingly, the gut microbiota also produces ligands of AHR from bacterial metabolism and thereby activates the AHR signaling pathway. This review presents current knowledge of the cross-regulatory circuit between the AHR and intestinal microbiota. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Choroidal retinoic acid synthesis: a possible mediator between refractive error and compensatory eye growth.

PubMed

Mertz, J R; Wallman, J

2000-04-01

Research over the past two decades has shown that the growth of young eyes is guided by vision. If near- or far-sightedness is artificially imposed by spectacle lenses, eyes of primates and chicks compensate by changing their rate of elongation, thereby growing back to the pre-lens optical condition. Little is known about what chemical signals might mediate between visual effects on the retina and alterations of eye growth. We present five findings that point to choroidal retinoic acid possibly being such a mediator. First, the chick choroid can convert retinol into all-trans-retinoic acid at the rate of 11 +/- 3 pmoles mg protein(-1) hr(-1), compared to 1.3 +/- 0.3 for retina/RPE and no conversion for sclera. Second, those visual conditions that cause increased rates of ocular elongation (diffusers or negative lens wear) produce a sharp decrease in all-trans-retinoic acid synthesis to levels barely detectable with our assay. In contrast, visual conditions which result in decreased rates of ocular elongation (recovery from diffusers or positive lens wear) produce a four- to five-fold increase in the formation of all-trans-retinoic acid. Third, the choroidal retinoic acid is found bound to a 28-32 kD protein. Fourth, a large fraction of the choroidal retinoic acid synthesized in culture is found in a nucleus-enriched fraction of sclera. Finally, application of retinoic acid to cultured sclera at physiological concentrations produced an inhibition of proteoglycan production (as assessed by measuring sulfate incorporation) with a EC50 of 8 x 10(-7) M. These results show that the synthesis of choroidal retinoic acid is modulated by those visual manipulations that influence ocular elongation and that this retinoic acid may reach the sclera in concentrations adequate to modulate scleral proteoglycan formation.

MATRIX METALLOPROTEINS (MMP)-MEDIATED PHOSPHORYLATION OF THE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR) IN HUMAN AIRWAY EPITHELIAL CELLS (HAEC) EXPOSED TO ZINC (ZN)

EPA Science Inventory

Matrix Metalloproteinase (MMP)-Mediated Phosphorylation of The Epidermal Growth Factor Receptor (EGFR) in Human Airway Epithelial Cells (HAEC) Exposed to Zinc (Zn)
Weidong Wu, James M. Samet, Robert Silbajoris, Lisa A. Dailey, Lee M. Graves, and Philip A. Bromberg
Center fo...

GARP: a surface molecule of regulatory T cells that is involved in the regulatory function and TGF-β releasing.

PubMed

Sun, Liping; Jin, Hao; Li, Hui

2016-07-05

There are many molecules that define regulatory T cells (Tregs) phenotypically and functionally. Glycoprotein A repetitions predominant (GARP) is a transmembrane protein containing leucine rich repeats. Recently, GARP is found to express highly on the surface of activated Tregs. The combination of GARP and other surface molecules isolates Tregs with higher purity. Besides, GARP is a cell surface molecule of Tregs that maintains their regulatory function and homeosatsis. GARP has also been proved to promote the activation and secretion of transforming growth factor β (TGF-β). Moreover, its potential value in cancer immunotherapy is also discussed in this work.

Knockout maternal adiponectin increases fetal growth in mice: potential role for trophoblast IGFBP-1.

PubMed

Qiao, Liping; Wattez, Jean-Sebastien; Lee, Samuel; Guo, Zhuyu; Schaack, Jerome; Hay, William W; Zita, Matteo Moretto; Parast, Mana; Shao, Jianhua

2016-11-01

The main objective of this study was to investigate whether maternal adiponectin regulates fetal growth through the endocrine system in the fetal compartment. Adiponectin knockout (Adipoq (-/-) ) mice and in vivo adenovirus-mediated reconstitution were used to study the regulatory effect of maternal adiponectin on fetal growth. Primary human trophoblast cells were treated with adiponectin and a specific peroxisome proliferator-activated receptor α (PPARα) agonist or antagonist to study the underlying mechanism through which adiponectin regulates fetal growth. The body weight of fetuses from Adipoq (-/-) dams was significantly greater than that of wild-type dams at both embryonic day (E)14.5 and E18.5. Adenoviral vector-mediated maternal adiponectin reconstitution attenuated the increased fetal body weight induced by maternal adiponectin deficiency. Significantly increased blood glucose, triacylglycerol and NEFA levels were observed in Adipoq (-/-) dams, suggesting that nutrient supply contributes to maternal adiponectin-regulated fetal growth. Although fetal blood IGF-1 concentrations were comparable in fetuses from Adipoq (-/-) and wild-type dams, remarkably low levels of IGF-binding protein 1 (IGFBP-1) were observed in the serum of fetuses from Adipoq (-/-) dams. IGFBP-1 was identified in the trophoblast cells of human and mouse placentas. Maternal fasting robustly increased IGFBP-1 levels in mouse placentas, while reducing fetal weight. Significantly low IGFBP-1 levels were found in placentas of Adipoq (-/-) dams. Adiponectin treatment increased IGFBP-1 levels in primary cultured human trophoblast cells, while the PPARα antagonist, MK886, abolished this stimulatory effect. These results indicate that, in addition to nutrient supply, maternal adiponectin inhibits fetal growth by increasing IGFBP-1 expression in trophoblast cells.

Knockout maternal adiponectin increases fetal growth in mice: potential role for trophoblast IGFBP-1

PubMed Central

Qiao, Liping; Wattez, Jean-Sebastien; Lee, Samuel; Guo, Zhuyu; Schaack, Jerome; Hay, William W.; Moretto Zita, Matteo; Parast, Mana; Shao, Jianhua

2016-01-01

Aims/hypothesis The main objective of this study was to investigate whether maternal adiponectin regulates fetal growth through the endocrine system in the fetal compartment. Methods Adiponectin knockout (Adipoq−/−) mice and in vivo adenovirus-mediated reconstitution were used to study the regulatory effect of maternal adiponectin on fetal growth. Primary human trophoblast cells were treated with adiponectin and a specific peroxisome proliferator-activated receptor α (PPARα) agonist or antagonist to study the underlying mechanism through which adiponectin regulates fetal growth. Results The body weight of fetuses from Adipoq−/− dams was significantly greater than that of wild-type dams at both embryonic day (E)14.5 and E18.5. Adenoviral vector-mediated maternal adiponectin reconstitution attenuated the increased fetal body weight induced by maternal adiponectin deficiency. Significantly increased blood glucose, triacylglycerol and NEFA levels were observed in Adipoq−/− dams, suggesting that nutrient supply contributes to maternal adiponectin-regulated fetal growth. Although fetal blood IGF-1 concentrations were comparable in fetuses from Adipoq−/− and wild-type dams, remarkably low levels of IGF-binding protein 1 (IGFBP-1) were observed in the serum of fetuses from Adipoq−/− dams. IGFBP-1 was identified in the trophoblast cells of human and mouse placentas. Maternal fasting robustly increased IGFBP-1 levels in mouse placentas, while reducing fetal weight. Significantly low IGFBP-1 levels were found in placentas of Adipoq−/− dams. Adiponectin treatment increased IGFBP-1 levels in primary cultured human trophoblast cells, while the PPARα antagonist, MK886, abolished this stimulatory effect. Conclusions/interpretation These results indicate that, in addition to nutrient supply, maternal adiponectin inhibits fetal growth by increasing IGFBP-1 expression in trophoblast cells. PMID:27495989

Beyond the functional matrix hypothesis: a network null model of human skull growth for the formation of bone articulations

PubMed Central

Esteve-Altava, Borja; Rasskin-Gutman, Diego

2014-01-01

Craniofacial sutures and synchondroses form the boundaries among bones in the human skull, providing functional, developmental and evolutionary information. Bone articulations in the skull arise due to interactions between genetic regulatory mechanisms and epigenetic factors such as functional matrices (soft tissues and cranial cavities), which mediate bone growth. These matrices are largely acknowledged for their influence on shaping the bones of the skull; however, it is not fully understood to what extent functional matrices mediate the formation of bone articulations. Aiming to identify whether or not functional matrices are key developmental factors guiding the formation of bone articulations, we have built a network null model of the skull that simulates unconstrained bone growth. This null model predicts bone articulations that arise due to a process of bone growth that is uniform in rate, direction and timing. By comparing predicted articulations with the actual bone articulations of the human skull, we have identified which boundaries specifically need the presence of functional matrices for their formation. We show that functional matrices are necessary to connect facial bones, whereas an unconstrained bone growth is sufficient to connect non-facial bones. This finding challenges the role of the brain in the formation of boundaries between bones in the braincase without neglecting its effect on skull shape. Ultimately, our null model suggests where to look for modified developmental mechanisms promoting changes in bone growth patterns that could affect the development and evolution of the head skeleton. PMID:24975579

Beyond the functional matrix hypothesis: a network null model of human skull growth for the formation of bone articulations.

PubMed

Esteve-Altava, Borja; Rasskin-Gutman, Diego

2014-09-01

Craniofacial sutures and synchondroses form the boundaries among bones in the human skull, providing functional, developmental and evolutionary information. Bone articulations in the skull arise due to interactions between genetic regulatory mechanisms and epigenetic factors such as functional matrices (soft tissues and cranial cavities), which mediate bone growth. These matrices are largely acknowledged for their influence on shaping the bones of the skull; however, it is not fully understood to what extent functional matrices mediate the formation of bone articulations. Aiming to identify whether or not functional matrices are key developmental factors guiding the formation of bone articulations, we have built a network null model of the skull that simulates unconstrained bone growth. This null model predicts bone articulations that arise due to a process of bone growth that is uniform in rate, direction and timing. By comparing predicted articulations with the actual bone articulations of the human skull, we have identified which boundaries specifically need the presence of functional matrices for their formation. We show that functional matrices are necessary to connect facial bones, whereas an unconstrained bone growth is sufficient to connect non-facial bones. This finding challenges the role of the brain in the formation of boundaries between bones in the braincase without neglecting its effect on skull shape. Ultimately, our null model suggests where to look for modified developmental mechanisms promoting changes in bone growth patterns that could affect the development and evolution of the head skeleton. © 2014 Anatomical Society.

A HLA class I cis-regulatory element whose activity can be modulated by hormones.

PubMed

Sim, B C; Hui, K M

1994-12-01

To elucidate the basis of the down-regulation in major histocompatibility complex (MHC) class I gene expression and to identify possible DNA-binding regulatory elements that have the potential to interact with class I MHC genes, we have studied the transcriptional regulation of class I HLA genes in human breast carcinoma cells. A 9 base pair (bp) negative cis-regulatory element (NRE) has been identified using band-shift assays employing DNA sequences derived from the 5'-flanking region of HLA class I genes. This 9-bp element, GTCATGGCG, located within exon I of the HLA class I gene, can potently inhibit the expression of a heterologous thymidine kinase (TK) gene promoter and the HLA enhancer element. Furthermore, this regulatory element can exert its suppressive function in either the sense or anti-sense orientation. More interestingly, NRE can suppress dexamethasone-mediated gene activation in the context of the reported glucocorticoid-responsive element (GRE) in MCF-7 cells but has no influence on the estrogen-mediated transcriptional activation of MCF-7 cells in the context of the reported estrogen-responsive element (ERE). Furthermore, the presence of such a regulatory element within the HLA class I gene whose activity can be modulated by hormones correlates well with our observation that the level of HLA class I gene expression can be down-regulated by hormones in human breast carcinoma cells. Such interactions between negative regulatory elements and specific hormone trans-activators are novel and suggest a versatile form of transcriptional control.

A multiphase model for tissue construct growth in a perfusion bioreactor.

PubMed

O'Dea, R D; Waters, S L; Byrne, H M

2010-06-01

The growth of a cell population within a rigid porous scaffold in a perfusion bioreactor is studied, using a three-phase continuum model of the type presented by Lemon et al. (2006, Multiphase modelling of tissue growth using the theory of mixtures. J. Math. Biol., 52, 571-594) to represent the cell population (and attendant extracellular matrix), culture medium and porous scaffold. The bioreactor system is modelled as a 2D channel containing the cell-seeded rigid porous scaffold (tissue construct) which is perfused with culture medium. The study concentrates on (i) the cell-cell and cell-scaffold interactions and (ii) the impact of mechanotransduction mechanisms on construct composition. A numerical and analytical analysis of the model equations is presented and, depending upon the relative importance of cell aggregation and repulsion, markedly different cell movement is revealed. Additionally, mechanotransduction effects due to cell density, pressure and shear stress-mediated tissue growth are shown to generate qualitative differences in the composition of the resulting construct. The results of our simulations indicate that this model formulation (in conjunction with appropriate experimental data) has the potential to provide a means of identifying the dominant regulatory stimuli in a cell population.

Potent Synergistic Effect of Doxycycline with Fluconazole against Candida albicans Is Mediated by Interference with Iron Homeostasis

PubMed Central

2012-01-01

Doxycycline was found to act synergistically with the antifungal fluconazole against Candida albicans. Combination with doxycycline converts fluconazole from fungistatic to fungicidal, prevents the onset of drug resistance, and is also effective against a clinical isolate characterized by elevated resistance to fluconazole. Investigation of the interactions between the two drugs by way of checkerboard assays indicated that doxycycline had an influence on the MIC for fluconazole, as defined by CLSI standards, only at high concentrations (200 μg/ml). However, lower concentrations were effective at eliminating residual cell growth at supra-MICs of fluconazole. Using MIC-0, defined as a drug combination resulting in optically clear wells, as an endpoint, doxycycline was found to be synergistic with fluconazole at a concentration as low as 25 μg/ml, with a fractional inhibitory concentration index of <0.5. Doxycycline-mediated growth inhibition can be reversed by externally added iron, indicating that iron depletion may account for the synergism. Consistently, we confirmed old literature data about iron-chelating activity of doxycycline. Synergism of fluconazole with doxycycline does not appear to be mediated by calcineurin, since doxycycline further aggravates the susceptibility to fluconazole of mutants lacking the catalytic or the regulatory subunits of calcineurin. Growth in the presence of fluconazole and doxycycline is restored by an elevated dosage of ERG11 in Saccharomyces cerevisiae but not in C. albicans, despite the full competence of the pathogen's protein to act as a suppressor in baker's yeast. PMID:22564841

Growth factors in the anterior segment: role in tissue maintenance, wound healing and ocular pathology.

PubMed

Klenkler, Bettina; Sheardown, Heather

2004-11-01

A number of growth factors and their associated receptors, including epidermal growth factor, transforming growth factor-beta, keratinocyte growth factor, hepatocyte growth factor, fibroblast growth factor and platelet-derived growth factor have been detected in the anterior segment of the eye. On binding to cellular receptors, these factors activate signalling cascades, which regulate functions including mitosis, differentiation, motility and apoptosis. Production of growth factors by corneal cells and their presence in the tear fluid and aqueous humour is essential for maintenance and renewal of normal tissue in the anterior eye and the prevention of undesirable immune or angiogenic reactions. Growth factors also play a vital role in corneal wound healing, mediating the proliferation of epithelial and stromal tissue and affecting the remodelling of the extracellular matrix (ECM). These functions depend on a complex interplay between growth factors of different types, the ECM, and regulatory mechanisms of the affected cells. Imbalances may lead to deficient wound healing and various ocular pathologies, including edema, neovascularization and glaucoma. Growth factors may be targeted in therapeutic ophthalmic applications, through exogenous application or selective inhibition, and may be used to elicit specific cellular responses to ophthalmic materials. A thorough understanding of the mechanism and function of growth factors and their actions in the complex environment of the anterior eye is required for these purposes. Growth factors, their function and mechanisms of action as well as the interplay between different growth factors based on recent in vitro and in vivo studies are presented.

Human myostatin negatively regulates human myoblast growth and differentiation

PubMed Central

McFarlane, Craig; Hui, Gu Zi; Amanda, Wong Zhi Wei; Lau, Hiu Yeung; Lokireddy, Sudarsanareddy; XiaoJia, Ge; Mouly, Vincent; Butler-Browne, Gillian; Gluckman, Peter D.; Sharma, Mridula

2011-01-01

Myostatin, a member of the transforming growth factor-β superfamily, has been implicated in the potent negative regulation of myogenesis in murine models. However, little is known about the mechanism(s) through which human myostatin negatively regulates human skeletal muscle growth. Using human primary myoblasts and recombinant human myostatin protein, we show here that myostatin blocks human myoblast proliferation by regulating cell cycle progression through targeted upregulation of p21. We further show that myostatin regulates myogenic differentiation through the inhibition of key myogenic regulatory factors including MyoD, via canonical Smad signaling. In addition, we have for the first time demonstrated the capability of myostatin to regulate the Notch signaling pathway during inhibition of human myoblast differentiation. Treatment with myostatin results in the upregulation of Hes1, Hes5, and Hey1 expression during differentiation; moreover, when we interfere with Notch signaling, through treatment with the γ-secretase inhibitor L-685,458, we find enhanced myotube formation despite the presence of excess myostatin. Therefore, blockade of the Notch pathway relieves myostatin repression of differentiation, and myostatin upregulates Notch downstream target genes. Immunoprecipitation studies demonstrate that myostatin treatment of myoblasts results in enhanced association of Notch1-intracellular domain with Smad3, providing an additional mechanism through which myostatin targets and represses the activity of the myogenic regulatory factor MyoD. On the basis of these results, we suggest that myostatin function and mechanism of action are very well conserved between species, and that myostatin regulation of postnatal myogenesis involves interactions with numerous downstream signaling mediators, including the Notch pathway. PMID:21508334

Human myostatin negatively regulates human myoblast growth and differentiation.

PubMed

McFarlane, Craig; Hui, Gu Zi; Amanda, Wong Zhi Wei; Lau, Hiu Yeung; Lokireddy, Sudarsanareddy; Xiaojia, Ge; Mouly, Vincent; Butler-Browne, Gillian; Gluckman, Peter D; Sharma, Mridula; Kambadur, Ravi

2011-07-01

Myostatin, a member of the transforming growth factor-β superfamily, has been implicated in the potent negative regulation of myogenesis in murine models. However, little is known about the mechanism(s) through which human myostatin negatively regulates human skeletal muscle growth. Using human primary myoblasts and recombinant human myostatin protein, we show here that myostatin blocks human myoblast proliferation by regulating cell cycle progression through targeted upregulation of p21. We further show that myostatin regulates myogenic differentiation through the inhibition of key myogenic regulatory factors including MyoD, via canonical Smad signaling. In addition, we have for the first time demonstrated the capability of myostatin to regulate the Notch signaling pathway during inhibition of human myoblast differentiation. Treatment with myostatin results in the upregulation of Hes1, Hes5, and Hey1 expression during differentiation; moreover, when we interfere with Notch signaling, through treatment with the γ-secretase inhibitor L-685,458, we find enhanced myotube formation despite the presence of excess myostatin. Therefore, blockade of the Notch pathway relieves myostatin repression of differentiation, and myostatin upregulates Notch downstream target genes. Immunoprecipitation studies demonstrate that myostatin treatment of myoblasts results in enhanced association of Notch1-intracellular domain with Smad3, providing an additional mechanism through which myostatin targets and represses the activity of the myogenic regulatory factor MyoD. On the basis of these results, we suggest that myostatin function and mechanism of action are very well conserved between species, and that myostatin regulation of postnatal myogenesis involves interactions with numerous downstream signaling mediators, including the Notch pathway.

Gibberllin driven growth in elf3 mutants requires PIF4 and PIF5

USDA-ARS?s Scientific Manuscript database

The regulatory connections between the circadian clock and hormone signaling are essential to understand, as these two regulatory processes work together to time growth processes relative to predictable environmental events. Gibberellins (GAs) are phytohormones that control many growth processes thr...

The effect of myostatin silencing by lentiviral-mediated RNA interference on goat fetal fibroblasts.

PubMed

Lu, Jian; Wei, Caihong; Zhang, Xiaoning; Xu, Lingyang; Zhang, Shifang; Liu, Jiasen; Cao, Jiaxue; Zhao, Fuping; Zhang, Li; Li, Bichun; Du, Lixin

2013-06-01

Myostatin is a transforming growth factor-β family member that acts as a negative regulator of skeletal muscle mass. To identify possible myostatin inhibitors that may promote muscle growth, we used RNA interference mediated by a lentiviral vector to knockdown myostatin in goat fetal fibroblast cells. We also investigated the expression changes in relevant myogenic regulatory factors (MRFs) and adipogenic regulatory factors in the absence of myostatin in goat fetal fibroblasts. Quantitative RT-PCR revealed that myostatin transcripts were significantly reduced by 75 % (P < 0.01). Western blot showed that myostatin protein expression was reduced by 95 % (P < 0.01). We also found that the mRNA expression of activin receptor IIB (ACVR2B) significantly increased by 350 % (P < 0.01), and p21 increased 172 % (P < 0.01). Furthermore, myostatin inhibition decreased Myf5 and increased MEF2C mRNA expression in goat fetal fibroblasts, suggesting that myostatin regulates MRFs differently in fibroblasts compared to muscle. In addition, the expression of adipocyte marker genes peroxisome proliferator-activated receptor (PPAR) γ and leptin, but not CCAAT/enhance-binding protein (C/EBP) α and C/EBPβ, were upregulated at the transcript level after myostatin silencing. These results suggest that we have generated a novel way to block myostatin in vitro, which could be used to improve livestock meat production and gene therapy of musculoskeletal diseases. This also suggests that myostatin plays a negative role in regulating the expression of adipogenesis related genes in goat fetal fibroblasts.

Contrasting mechanisms of growth in two model rod-shaped bacteria

PubMed Central

Billaudeau, Cyrille; Chastanet, Arnaud; Yao, Zhizhong; Cornilleau, Charlène; Mirouze, Nicolas; Fromion, Vincent; Carballido-López, Rut

2017-01-01

How cells control their shape and size is a long-standing question in cell biology. Many rod-shaped bacteria elongate their sidewalls by the action of cell wall synthesizing machineries that are associated to actin-like MreB cortical patches. However, little is known about how elongation is regulated to enable varied growth rates and sizes. Here we use total internal reflection fluorescence microscopy and single-particle tracking to visualize MreB isoforms, as a proxy for cell wall synthesis, in Bacillus subtilis and Escherichia coli cells growing in different media and during nutrient upshift. We find that these two model organisms appear to use orthogonal strategies to adapt to growth regime variations: B. subtilis regulates MreB patch speed, while E. coli may mainly regulate the production capacity of MreB-associated cell wall machineries. We present numerical models that link MreB-mediated sidewall synthesis and cell elongation, and argue that the distinct regulatory mechanism employed might reflect the different cell wall integrity constraints in Gram-positive and Gram-negative bacteria. PMID:28589952

Drosophila growth cones: a genetically tractable platform for the analysis of axonal growth dynamics.

PubMed

Sánchez-Soriano, Natalia; Gonçalves-Pimentel, Catarina; Beaven, Robin; Haessler, Ulrike; Ofner-Ziegenfuss, Lisa; Ballestrem, Christoph; Prokop, Andreas

2010-01-01

The formation of neuronal networks, during development and regeneration, requires outgrowth of axons along reproducible paths toward their appropriate postsynaptic target cells. Axonal extension occurs at growth cones (GCs) at the tips of axons. GC advance and navigation requires the activity of their cytoskeletal networks, comprising filamentous actin (F-actin) in lamellipodia and filopodia as well as dynamic microtubules (MTs) emanating from bundles of the axonal core. The molecular mechanisms governing these two cytoskeletal networks, their cross-talk, and their response to extracellular signaling cues are only partially understood, hindering our conceptual understanding of how regulated changes in GC behavior are controlled. Here, we introduce Drosophila GCs as a suitable model to address these mechanisms. Morphological and cytoskeletal readouts of Drosophila GCs are similar to those of other models, including mammals, as demonstrated here for MT and F-actin dynamics, axonal growth rates, filopodial structure and motility, organizational principles of MT networks, and subcellular marker localization. Therefore, we expect fundamental insights gained in Drosophila to be translatable into vertebrate biology. The advantage of the Drosophila model over others is its enormous amenability to combinatorial genetics as a powerful strategy to address the complexity of regulatory networks governing axonal growth. Thus, using pharmacological and genetic manipulations, we demonstrate a role of the actin cytoskeleton in a specific form of MT organization (loop formation), known to regulate GC pausing behavior. We demonstrate these events to be mediated by the actin-MT linking factor Short stop, thus identifying an essential molecular player in this context.

Selective regulation of clathrin-mediated epidermal growth factor receptor signaling and endocytosis by phospholipase C and calcium.

PubMed

Delos Santos, Ralph Christian; Bautista, Stephen; Lucarelli, Stefanie; Bone, Leslie N; Dayam, Roya M; Abousawan, John; Botelho, Roberto J; Antonescu, Costin N

2017-10-15

Clathrin-mediated endocytosis is a major regulator of cell-surface protein internalization. Clathrin and other proteins assemble into small invaginating structures at the plasma membrane termed clathrin-coated pits (CCPs) that mediate vesicle formation. In addition, epidermal growth factor receptor (EGFR) signaling is regulated by its accumulation within CCPs. Given the diversity of proteins regulated by clathrin-mediated endocytosis, how this process may distinctly regulate specific receptors is a key question. We examined the selective regulation of clathrin-dependent EGFR signaling and endocytosis. We find that perturbations of phospholipase Cγ1 (PLCγ1), Ca 2+ , or protein kinase C (PKC) impair clathrin-mediated endocytosis of EGFR, the formation of CCPs harboring EGFR, and EGFR signaling. Each of these manipulations was without effect on the clathrin-mediated endocytosis of transferrin receptor (TfR). EGFR and TfR were recruited to largely distinct clathrin structures. In addition to control of initiation and assembly of CCPs, EGF stimulation also elicited a Ca 2+ - and PKC-dependent reduction in synaptojanin1 recruitment to clathrin structures, indicating broad control of CCP assembly by Ca 2+ signals. Hence EGFR elicits PLCγ1-calcium signals to facilitate formation of a subset of CCPs, thus modulating its own signaling and endocytosis. This provides evidence for the versatility of CCPs to control diverse cellular processes. © 2017 Delos Santos et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

CAREGIVER-CHILD INTERACTION, CAREGIVER TRANSITIONS, AND GROUP SIZE AS MEDIATORS BETWEEN INTERVENTION CONDITION AND ATTACHMENT AND PHYSICAL GROWTH OUTCOMES IN INSTITUTIONALIZED CHILDREN.

PubMed

Warner, Hilary A; McCall, Robert B; Groark, Christina J; Kim, Kevin H; Muhamedrahimov, Rifkat J; Palmov, Oleg I; Nikiforova, Natalia V

2017-09-01

This report describes a secondary analysis of data from a comprehensive intervention project which included training and structural changes in three Baby Homes in St. Petersburg, Russian Federation. Multiple mediator models were tested according to the R.M. Baron and D.A. Kenny () causal-steps approach to examine whether caregiver-child interaction quality, number of caregiver transitions, and group size mediated the effects of the intervention on children's attachment behaviors and physical growth. The study utilized a subsample of 163 children from the original Russian Baby Home project, who were between 11 and 19 months at the time of assessment. Results from comparisons of the training and structural changes versus no intervention conditions are presented. Caregiver-child interaction quality and number of caregiver transitions fully mediated the association between intervention condition and attachment behavior. No other mediation was found. Results suggest that the quality of interaction between caregivers and children in institutional care is of primary importance to children's development, but relationship context may play a less direct mediational role, supporting caregiver-child interactions. © 2017 Michigan Association for Infant Mental Health.

BAG3 down-modulation reduces anaplastic thyroid tumor growth by enhancing proteasome-mediated degradation of BRAF protein.

PubMed

Chiappetta, Gennaro; Basile, Anna; Arra, Claudio; Califano, Daniela; Pasquinelli, Rosa; Barbieri, Antonio; De Simone, Veronica; Rea, Domenica; Giudice, Aldo; Pezzullo, Luciano; De Laurenzi, Vincenzo; Botti, Gerardo; Losito, Simona; Conforti, Daniela; Turco, Maria Caterina

2012-01-01

Anaplastic thyroid tumors (ATC) express high levels of BAG3, a member of the BAG family of cochaperone proteins that is involved in regulating cell apoptosis through multiple mechanisms. The objective of the study was the investigation of the influence of B-cell lymphoma-2-associated athanogene 3 (BAG3) on ATC growth. We investigated the effects of BAG3 down-modulation, obtained by using a specific small interfering RNA, on in vitro and in vivo growth of the human ATC cell line 8505C. Because BRAF protein plays an important role in ATC cell growth, we analyzed the effects of BAG3 down-modulation on BRAF protein levels. Furthermore, by using a proteasome inhibitor, we verified whether BAG3-mediated regulation of BRAF levels involved a proteasome-dependent mechanism. BAG3 down-modulation significantly inhibits ATC growth in vitro and in vivo. BAG3 coimmunoprecipitates with BRAF protein, and its down-modulation results in a significant reduction of BRAF protein levels, which can be reverted by incubation with the proteasome inhibitor MG132. BAG3 protein sustains ATC growth in vitro and in vivo. The underlying molecular mechanism appears to rely on BAG3 binding to BRAF, thus protecting it from proteasome-dependent degradation. These results are in line with the reported ability of BAG3 to interfere with the proteasomal delivery of a number of other client proteins.

Two Distinct Families of Protein Kinases Are Required for Plant Growth under High External Mg2+ Concentrations in Arabidopsis1

PubMed Central

Mogami, Junro; Fujita, Yasunari; Yoshida, Takuya; Tsukiori, Yoshifumi; Nakagami, Hirofumi; Nomura, Yuko; Fujiwara, Toru; Nishida, Sho; Yanagisawa, Shuichi; Ishida, Tetsuya; Takahashi, Fuminori; Morimoto, Kyoko; Kidokoro, Satoshi; Mizoi, Junya; Shinozaki, Kazuo

2015-01-01

Protein phosphorylation events play key roles in maintaining cellular ion homeostasis in higher plants, and the regulatory roles of these events in Na+ and K+ transport have been studied extensively. However, the regulatory mechanisms governing Mg2+ transport and homeostasis in higher plants remain poorly understood, despite the vital roles of Mg2+ in cellular function. A member of subclass III sucrose nonfermenting-1-related protein kinase2 (SnRK2), SRK2D/SnRK2.2, functions as a key positive regulator of abscisic acid (ABA)-mediated signaling in response to water deficit stresses in Arabidopsis (Arabidopsis thaliana). Here, we used immunoprecipitation coupled with liquid chromatography-tandem mass spectrometry analyses to identify Calcineurin B-like-interacting protein kinase26 (CIPK26) as a novel protein that physically interacts with SRK2D. In addition to CIPK26, three additional CIPKs (CIPK3, CIPK9, and CIPK23) can physically interact with SRK2D in planta. The srk2d/e/i triple mutant lacking all three members of subclass III SnRK2 and the cipk26/3/9/23 quadruple mutant lacking CIPK26, CIPK3, CIPK9, and CIPK23 showed reduced shoot growth under high external Mg2+ concentrations. Similarly, several ABA biosynthesis-deficient mutants, including aba2-1, were susceptible to high external Mg2+ concentrations. Taken together, our findings provided genetic evidence that SRK2D/E/I and CIPK26/3/9/23 are required for plant growth under high external Mg2+ concentrations in Arabidopsis. Furthermore, we showed that ABA, a key molecule in water deficit stress signaling, also serves as a signaling molecule in plant growth under high external Mg2+ concentrations. These results suggested that SRK2D/E/I- and CIPK26/3/9/23-mediated phosphorylation signaling pathways maintain cellular Mg2+ homeostasis. PMID:25614064

Genetic Tools for Self-Organizing Culture of Mouse Embryonic Stem Cells via Small Regulatory RNA-Mediated Technologies, CRISPR/Cas9, and Inducible RNAi.

PubMed

Takata, Nozomu; Sakakura, Eriko; Sakuma, Tetsushi; Yamamoto, Takashi

2017-01-01

Approaches to investigate gene functions in experimental biology are becoming more diverse and reliable. Furthermore, several kinds of tissues and organs that possess their original identities can be generated in petri dishes from stem cells including embryonic, adult and induced pluripotent stem cells. Researchers now have several choices of experimental methods and their combinations to analyze gene functions in various biological systems. Here, as an example we describe one of the better protocols, which combines three-dimensional embryonic stem cell culture with small regulatory RNA-mediated technologies, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9), and inducible RNA interference (RNAi). This protocol allows investigation of genes of interest to better understand gene functions in target tissues (or organs) during in vitro development.

Differential identity of Filopodia and Tunneling Nanotubes revealed by the opposite functions of actin regulatory complexes.

PubMed

Delage, Elise; Cervantes, Diégo Cordero; Pénard, Esthel; Schmitt, Christine; Syan, Sylvie; Disanza, Andrea; Scita, Giorgio; Zurzolo, Chiara

2016-12-23

Tunneling Nanotubes (TNTs) are actin enriched filopodia-like protrusions that play a pivotal role in long-range intercellular communication. Different pathogens use TNT-like structures as "freeways" to propagate across cells. TNTs are also implicated in cancer and neurodegenerative diseases, making them promising therapeutic targets. Understanding the mechanism of their formation, and their relation with filopodia is of fundamental importance to uncover their physiological function, particularly since filopodia, differently from TNTs, are not able to mediate transfer of cargo between distant cells. Here we studied different regulatory complexes of actin, which play a role in the formation of both these structures. We demonstrate that the filopodia-promoting CDC42/IRSp53/VASP network negatively regulates TNT formation and impairs TNT-mediated intercellular vesicle transfer. Conversely, elevation of Eps8, an actin regulatory protein that inhibits the extension of filopodia in neurons, increases TNT formation. Notably, Eps8-mediated TNT induction requires Eps8 bundling but not its capping activity. Thus, despite their structural similarities, filopodia and TNTs form through distinct molecular mechanisms. Our results further suggest that a switch in the molecular composition in common actin regulatory complexes is critical in driving the formation of either type of membrane protrusion.

Distinct gene regulatory programs define the inhibitory effects of liver X receptors and PPARG on cancer cell proliferation.

PubMed

Savic, Daniel; Ramaker, Ryne C; Roberts, Brian S; Dean, Emma C; Burwell, Todd C; Meadows, Sarah K; Cooper, Sara J; Garabedian, Michael J; Gertz, Jason; Myers, Richard M

2016-07-11

The liver X receptors (LXRs, NR1H2 and NR1H3) and peroxisome proliferator-activated receptor gamma (PPARG, NR1C3) nuclear receptor transcription factors (TFs) are master regulators of energy homeostasis. Intriguingly, recent studies suggest that these metabolic regulators also impact tumor cell proliferation. However, a comprehensive temporal molecular characterization of the LXR and PPARG gene regulatory responses in tumor cells is still lacking. To better define the underlying molecular processes governing the genetic control of cellular growth in response to extracellular metabolic signals, we performed a comprehensive, genome-wide characterization of the temporal regulatory cascades mediated by LXR and PPARG signaling in HT29 colorectal cancer cells. For this analysis, we applied a multi-tiered approach that incorporated cellular phenotypic assays, gene expression profiles, chromatin state dynamics, and nuclear receptor binding patterns. Our results illustrate that the activation of both nuclear receptors inhibited cell proliferation and further decreased glutathione levels, consistent with increased cellular oxidative stress. Despite a common metabolic reprogramming, the gene regulatory network programs initiated by these nuclear receptors were widely distinct. PPARG generated a rapid and short-term response while maintaining a gene activator role. By contrast, LXR signaling was prolonged, with initial, predominantly activating functions that transitioned to repressive gene regulatory activities at late time points. Through the use of a multi-tiered strategy that integrated various genomic datasets, our data illustrate that distinct gene regulatory programs elicit common phenotypic effects, highlighting the complexity of the genome. These results further provide a detailed molecular map of metabolic reprogramming in cancer cells through LXR and PPARG activation. As ligand-inducible TFs, these nuclear receptors can potentially serve as attractive therapeutic

Nutritionally Mediated Programming of the Developing Immune System12

PubMed Central

Palmer, Amanda C.

2011-01-01

A growing body of evidence highlights the importance of a mother’s nutrition from preconception through lactation in programming the emerging organ systems and homeostatic pathways of her offspring. The developing immune system may be particularly vulnerable. Indeed, examples of nutrition-mediated immune programming can be found in the literature on intra-uterine growth retardation, maternal micronutrient deficiencies, and infant feeding. Current models of immune ontogeny depict a “layered” expansion of increasingly complex defenses, which may be permanently altered by maternal malnutrition. One programming mechanism involves activation of the maternal hypothalamic-pituitary-adrenal axis in response to nutritional stress. Fetal or neonatal exposure to elevated stress hormones is linked in animal studies to permanent changes in neuroendocrine-immune interactions, with diverse manifestations such as an attenuated inflammatory response or reduced resistance to tumor colonization. Maternal malnutrition may also have a direct influence, as evidenced by nutrient-driven epigenetic changes to developing T regulatory cells and subsequent risk of allergy or asthma. A 3rd programming pathway involves placental or breast milk transfer of maternal immune factors with immunomodulatory functions (e.g. cytokines). Maternal malnutrition can directly affect transfer mechanisms or influence the quality or quantity of transferred factors. The public health implications of nutrition-mediated immune programming are of particular importance in the developing world, where prevalent maternal undernutrition is coupled with persistent infectious challenges. However, early alterations to the immune system, resulting from either nutritional deficiencies or excesses, have broad relevance for immune-mediated diseases, such as asthma, and chronic inflammatory conditions like cardiovascular disease. PMID:22332080

Modified Clonidine Testing for Growth Hormone Stimulation Reveals α2-Adrenoreceptor Sub Sensitivity in Children with Idiopathic Growth Hormone Deficiency.

PubMed

Willaschek, Christian; Meint, Sebastian; Rager, Klaus; Buchhorn, Reiner

2015-01-01

The association between short stature and increased risk of ischemic heart disease has been subject to studies for decades. The recent discussion of cardiovascular risk during growth hormone therapy has given new importance to this question. We have hypothesized that the autonomic system is a crucial element relating to this subject. Heart rate variability calculated from 24-hour electrocardiogram data is providing insight into the regulatory state of the autonomous nervous system and is an approved surrogate parameter for estimating cardiovascular risk. We have calculated heart rate variability during clonidine testing for growth hormone stimulation of 56 children. As clonidine is a well-known effector of the autonomous system, stimulating vagal tone and decreasing sympathetic activity, we compared the autonomous reactions of children with constitutional growth delay (CGD), growth hormone deficiency (GHD) and former small for gestational age (SGA). During clonidine testing children with CGD showed the expected α2-adrenoreceptor mediated autonomous response of vagal stimulation for several hours. This vagal reaction was significantly reduced in the SGA group and nearly non- existent in the GHD group. Children with GHD show a reduced autonomous response to clonidine indicating α2-adrenoreceptor sub sensitivity. This can be found prior to the start of growth hormone treatment. Since reduction of HRV is an approved surrogate parameter, increased cardiovascular risk has to be assumed for patients with GHD. In the SGA group a similar but less severe reduction of the autonomous response to clonidine was found. These findings may enrich the interpretation of the data on growth hormone therapy, which are being collected by the SAGhE study group.

Stromal Tissue Rigidity Promotes Mesenchymal Stem Cell-Mediated Corneal Wound Healing Through the Transforming Growth Factor β Signaling Pathway.

PubMed

Yang, Yun-Hsiang; Hsieh, Ting-Lieh; Ji, Andrea Tung-Qian; Hsu, Wei-Tse; Liu, Chia-Yu; Lee, Oscar Kuang-Sheng; Ho, Jennifer Hui-Chun

2016-10-01

The healing of a corneal epithelial defect is essential for preventing infectious corneal ulcers and subsequent blindness. We previously demonstrated that mesenchymal stem cells (MSCs) in the corneal stroma, through a paracrine mechanism, yield a more favorable therapeutic benefit for corneal wound re-epithelialization than do MSCs in the corneal epithelium. In this study, MSCs were grown on a matrix with the rigidity of the physiological human vitreous (1 kPa), corneal epithelium (8 kPa), or corneal stroma (25 kPa) for investigating the role of corneal tissue rigidity in MSC functions regarding re-epithelialization promotion. MSC growth on a 25-kPa dish significantly promoted the wound healing of human corneal epithelial (HCE-T) cells. Among growth factors contributing to corneal epithelial wound healing, corneal stromal rigidity selectively enhanced transforming growth factor-beta (TGF-β) secretion from MSCs. Inhibitors of TGF-β pan receptor, TGF-β receptor 1, and Smad2 dose dependently abrogated MSC-mediated HCE-T wound healing. Furthermore, MSCs growth on a matrix with corneal stromal rigidity enhanced the ability of themselves to promote corneal re-epithelialization by activating matrix metalloproteinase (MMP) expression and integrin β1 production in HCE-T cells through TGF-β signaling pathway activation. Smad2 activation resulted in the upregulation of MMP-2 and -13 expression in HCE-T cells, whereas integrin β1 production favored a Smad2-independent TGF-β pathway. Altogether, we conclude that corneal stromal rigidity is a critical factor for MSC-induced promotion of corneal re-epithelialization. The activation of the TGF-β signaling pathway, which maintains the balance between integrin and MMP expression, in HCE-T cells is the major pathway responsible for MSC-mediated wound healing. Stem Cells 2016;34:2525-2535. © 2016 AlphaMed Press.

Nuclear organization mediates cancer-compromised genetic and epigenetic control.

PubMed

Zaidi, Sayyed K; Fritz, Andrew; Tracy, Kirsten; Gordon, Jonathan; Tye, Coralee; Boyd, Joseph; Van Wijnen, Andre; Nickerson, Jeffrey; Imbalzano, Anthony; Lian, Jane; Stein, Janet; Stein, Gary

2018-05-09

Nuclear organization is functionally linked to genetic and epigenetic regulation of gene expression for biological control and is modified in cancer. Nuclear organization supports cell growth and phenotypic properties of normal and cancer cells by facilitating physiologically responsive interactions of chromosomes, genes and regulatory complexes at dynamic three-dimensional microenvironments. We will review nuclear structure/function relationships that include: 1. Epigenetic bookmarking of genes by phenotypic transcription factors to control fidelity and plasticity of gene expression as cells enter and exit mitosis; 2. Contributions of chromatin remodeling to breast cancer nuclear morphology, metabolism and effectiveness of chemotherapy; 3. Relationships between fidelity of nuclear organization and metastasis of breast cancer to bone; 4. Dynamic modifications of higher-order inter- and intra-chromosomal interactions in breast cancer cells; 5. Coordinate control of cell growth and phenotype by tissue-specific transcription factors; 6. Oncofetal epigenetic control by bivalent histone modifications that are functionally related to sustaining the stem cell phenotype; and 7. Noncoding RNA-mediated regulation in the onset and progression of breast cancer. The discovery of components to nuclear organization that are functionally related to cancer and compromise gene expression have the potential for translation to innovative cancer diagnosis and targeted therapy. Copyright © 2018 Elsevier Ltd. All rights reserved.

Insulin-like growth factor-1 is a mediator of age-related decline of bone health status in men.

PubMed

Chin, Kok-Yong; Ima-Nirwana, Soelaiman; Mohamed, Isa Naina; Hanapi Johari, Mohamad; Ahmad, Fairus; Mohamed Ramli, Elvy Suhana; Wan Ngah, Wan Zurinah

2014-06-01

The role of insulin-like growth factor-1 (IGF-1) in bone health in men is debatable. This study aimed to determine whether IGF-1 is a mediator in age-related decline of bone health status measured by calcaneal speed of sound (SOS) in Malaysian men. The study recruited 279 Chinese and Malay men. Their demographic data, weight, height, calcaneal SOS were taken and fasting blood was collected for total testosterone, sex-hormone binding globulin and IGF-1 assays. The associations between the studied variables were assessed using multiple linear regression (MLR) analysis. Mediator analysis was performed using Sobel test. There was a significant and parallel decrease of IGF-1 and SOS with age (p < 0.05). Serum IGF-1 was significantly and positively associated with SOS (p < 0.05) but after further adjustment for age, the significance was lost (p > 0.05). The strength of the association between age and SOS decreased after adjusting for IGF-1 level but it remained significant (p < 0.05). Sobel test revealed that IGF-1 was a significant partial mediator in the relationship between age and SOS (z = -4.3). Serum IGF-1 is a partial mediator in the age-related decline of bone health in men as determined by calcaneal ultrasound. A prospective study should be performed to validate this relationship.

Polyethylene Glycol Mediated Colorectal Cancer Chemoprevention: Roles of Epidermal Growth Factor Receptor and Snail

PubMed Central

Wali, Ramesh K.; Kunte, Dhananjay P.; Koetsier, Jennifer L.; Bissonnette, Marc; Roy, Hemant K.

2008-01-01

Polyethylene glycol (PEG) is a clinically widely used agent with profound chemopreventive properties in experimental colon carcinogenesis. We previously reported that Snail/β-catenin signaling may mediate the suppression of epithelial proliferation by PEG, although the upstream events remain unclear. We report herein the role of epidermal growth factor receptor (EGFR), a known mediator of Snail and overepressed in ~80% of human colorectal cancers (CRC), on PEG-mediated anti-proliferative and hence anti-neoplastic effects in azoxymethane (AOM)-rats and HT-29 colon cancer cells. AOM-rats were randomized to either standard diet or one with 10% PEG 3350 and euthanized 8 weeks later. The colonic samples were subjected to immunohistochemical or Western blot analyses. PEG decreased mucosal EGFR by 60% (p<0.001). Similar PEG effects were obtained in HT-29 cells. PEG suppressed EGFR protein via lysosmal degradation with no change in mRNA levels. To show that EGFR antagonism per se was responsible for the antiproliferative effect, we inhibited EGFR by either pre-treating cells with gefitinib or stably transfecting with EGFR-shRNA and measured the effect of PEG on proliferation. In either case PEG effect was blunted suggesting a vital role of EGFR. Flow cytometric analysis revealed that EGFR-shRNA cells, besides having reduced membrane EGFR also expressed low Snail levels (40%), corroborating a strong association. Furthermore, in EGFR silenced cells PEG effect on EGFR or Snail was muted, similar to that on proliferation. In conclusion, we show that EGFR is the proximate membrane signaling molecule through which PEG initiates antiproliferative activity with Snail/β-catenin pathway playing the central intermediary function. PMID:18790788

Polyethylene glycol-mediated colorectal cancer chemoprevention: roles of epidermal growth factor receptor and Snail.

PubMed

Wali, Ramesh K; Kunte, Dhananjay P; Koetsier, Jennifer L; Bissonnette, Marc; Roy, Hemant K

2008-09-01

Polyethylene glycol (PEG) is a clinically widely used agent with profound chemopreventive properties in experimental colon carcinogenesis. We reported previously that Snail/beta-catenin signaling may mediate the suppression of epithelial proliferation by PEG, although the upstream events remain unclear. We report herein the role of epidermal growth factor receptor (EGFR), a known mediator of Snail and overexpressed in approximately 80% of human colorectal cancers, on PEG-mediated antiproliferative and hence antineoplastic effects in azoxymethane (AOM) rats and HT-29 colon cancer cells. AOM rats were randomized to either standard diet or one with 10% PEG-3350 and euthanized 8 weeks later. The colonic samples were subjected to immunohistochemical or Western blot analyses. PEG decreased mucosal EGFR by 60% (P < 0.001). Similar PEG effects were obtained in HT-29 cells. PEG suppressed EGFR protein via lysosmal degradation with no change in mRNA levels. To show that EGFR antagonism per se was responsible for the antiproliferative effect, we inhibited EGFR by either pretreating cells with gefitinib or stably transfecting with EGFR-short hairpin RNA and measured the effect of PEG on proliferation. In either case, PEG effect was blunted, suggesting a vital role of EGFR. Flow cytometric analysis revealed that EGFR-short hairpin RNA cells, besides having reduced membrane EGFR, also expressed low Snail levels (40%), corroborating a strong association. Furthermore, in EGFR silenced cells, PEG effect on EGFR or Snail was muted, similar to that on proliferation. In conclusion, we show that EGFR is the proximate membrane signaling molecule through which PEG initiates antiproliferative activity with Snail/beta-catenin pathway playing the central intermediary function.

Epidermal growth factor receptor signaling mediates aldosterone-induced profibrotic responses in kidney

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheng, Lili; Yang, Min; Ding, Wei

Aldosterone has been recognized as a risk factor for the development of chronic kidney disease (CKD). Studies have indicated that enhanced activation of epidermal growth factor receptor (EGFR) is associated with the development and progression of renal fibrosis. But if EGFR is involved in aldosterone-induced renal fibrosis is less investigated. In the present study, we examined the effect of erlotinib, an inhibitor of EGFR tyrosine kinase activity, on the progression of aldosterone-induced renal profibrotic responses in a murine model underwent uninephrectomy. Erlotinib-treated rats exhibited relieved structural lesion comparing with rats treated with aldosterone alone, as characterized by glomerular hypertrophy, mesangialmore » cell proliferation and expansion. Also, erlotinib inhibited the expression of TGF-β, α-SMA and mesangial matrix proteins such as collagen Ⅳ and fibronectin. In cultured mesangial cells, inhibition of EGFR also abrogated aldosterone-induced expression of extracellular matrix proteins, cell proliferation and migration. We also demonstrated that aldosterone induced the phosphorylation of EGFR through generation of ROS. And the activation of EGFR resulted in the phosphorylation of ERK1/2, leading to the activation of profibrotic pathways. Taken together, we concluded that aldosterone-mediated tissue fibrosis relies on ROS induced EGFR/ERK activation, highlighting EGFR as a potential therapeutic target for modulating renal fibrosis. - Highlights: • EGFR was involved in aldosterone-induced renal profibrotic responses. • Aldosterone-induced EGFR activation was mediated by MR-dependent ROS generation. • EGFR activated the MAPK/ERK1/2 signaling to promote renal fibrosis.« less

Ligand Receptor-Mediated Regulation of Growth in Plants.

PubMed

Haruta, Miyoshi; Sussman, Michael R

2017-01-01

Growth and development of multicellular organisms are coordinately regulated by various signaling pathways involving the communication of inter- and intracellular components. To form the appropriate body patterns, cellular growth and development are modulated by either stimulating or inhibiting these pathways. Hormones and second messengers help to mediate the initiation and/or interaction of the various signaling pathways in all complex multicellular eukaryotes. In plants, hormones include small organic molecules, as well as larger peptides and small proteins, which, as in animals, act as ligands and interact with receptor proteins to trigger rapid biochemical changes and induce the intracellular transcriptional and long-term physiological responses. During the past two decades, the availability of genetic and genomic resources in the model plant species, Arabidopsis thaliana, has greatly helped in the discovery of plant hormone receptors and the components of signal transduction pathways and mechanisms used by these immobile but highly complex organisms. Recently, it has been shown that two of the most important plant hormones, auxin and abscisic acid (ABA), act through signaling pathways that have not yet been recognized in animals. For example, auxins stimulate cell elongation by bringing negatively acting transcriptional repressor proteins to the proteasome to be degraded, thus unleashing the gene expression program required for increasing cell size. The "dormancy" inducing hormone, ABA, binds to soluble receptor proteins and inhibits a specific class of protein phosphatases (PP2C), which activates phosphorylation signaling leading to transcriptional changes needed for the desiccation of the seeds prior to entering dormancy. While these two hormone receptors have no known animal counterparts, there are also many similarities between animal and plant signaling pathways. For example, in plants, the largest single gene family in the genome is the protein kinase

Human microRNA-1245 down-regulates the NKG2D receptor in natural killer cells and impairs NKG2D-mediated functions

PubMed Central

Espinoza, J. Luis; Takami, Akiyoshi; Yoshioka, Katsuji; Nakata, Katsuya; Sato, Tokiharu; Kasahara, Yoshihito; Nakao, Shinji

2012-01-01

Background NKG2D is an activating receptor expressed by natural killer and T cells, which have crucial functions in tumor and microbial immunosurveillance. Several cytokines have been identified as modulators of NKG2D receptor expression. However, little is known about NKG2D gene regulation. In this study, we found that microRNA 1245 attenuated the expression of NKG2D in natural killer cells. Design and Methods We investigated the potential interactions between the 3′-untranslated region of the NKG2D gene and microRNA as well as their functional roles in the regulation of NKG2D expression and cytotoxicity in natural killer cells. Results Transforming growth factor-β1, a major negative regulator of NKG2D expression, post-transcriptionally up-regulated mature microRNA-1245 expression, thus down-regulating NKG2D expression and impairing NKG2D-mediated immune responses in natural killer cells. Conversely, microRNA-1245 down-regulation significantly increased the expression of NKG2D expression in natural killer cells, resulting in more efficient NKG2D-mediated cytotoxicity. Conclusions These results reveal a novel NKG2D regulatory pathway mediated by microRNA-1245, which may represent one of the mechanisms used by transforming growth factor-β1 to attenuate NKG2D expression in natural killer cells. PMID:22491735

Regulatory T cells ameliorate tissue plasminogen activator-induced brain haemorrhage after stroke.

PubMed

Mao, Leilei; Li, Peiying; Zhu, Wen; Cai, Wei; Liu, Zongjian; Wang, Yanling; Luo, Wenli; Stetler, Ruth A; Leak, Rehana K; Yu, Weifeng; Gao, Yanqin; Chen, Jun; Chen, Gang; Hu, Xiaoming

2017-07-01

studies demonstrated that regulatory T cells completely abolished the tPA-induced elevation of MMP9 and CCL2 after stroke. Using MMP9 and CCL2 knockout mice, we discovered that both molecules partially contributed to the protective actions of regulatory T cells. In an in vitro endothelial cell-based model of the blood-brain barrier, we confirmed that regulatory T cells inhibited tPA-induced endothelial expression of CCL2 and preserved blood-brain barrier integrity after an ischaemic challenge. Lentivirus-mediated CCL2 knockdown in endothelial cells completely abolished the blood-brain barrier protective effect of regulatory T cells in vitro. Altogether, our studies suggest that regulatory T cell adoptive transfer may alleviate thrombolytic treatment-induced haemorrhage in stroke victims. Furthermore, regulatory T cell-afforded protection in the tPA-treated stroke model is mediated by two inhibitory mechanisms involving CCL2 and MMP9. Thus, regulatory T cell adoptive transfer may be useful as a cell-based therapy to improve the efficacy and safety of thrombolytic treatment for ischaemic stroke. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Local Epidermal Growth Factor Receptor Signaling Mediates the Systemic Pathogenic Effects of Staphylococcus aureus Toxic Shock Syndrome.

PubMed

Breshears, Laura M; Gillman, Aaron N; Stach, Christopher S; Schlievert, Patrick M; Peterson, Marnie L

2016-01-01

Secreted factors of Staphylococcus aureus can activate host signaling from the epidermal growth factor receptor (EGFR). The superantigen toxic shock syndrome toxin-1 (TSST-1) contributes to mucosal cytokine production through a disintegrin and metalloproteinase (ADAM)-mediated shedding of EGFR ligands and subsequent EGFR activation. The secreted hemolysin, α-toxin, can also induce EGFR signaling and directly interacts with ADAM10, a sheddase of EGFR ligands. The current work explores the role of EGFR signaling in menstrual toxic shock syndrome (mTSS), a disease mediated by TSST-1. The data presented show that TSST-1 and α-toxin induce ADAM- and EGFR-dependent cytokine production from human vaginal epithelial cells. TSST-1 and α-toxin also induce cytokine production from an ex vivo porcine vaginal mucosa (PVM) model. EGFR signaling is responsible for the majority of IL-8 production from PVM in response to secreted toxins and live S. aureus. Finally, data are presented demonstrating that inhibition of EGFR signaling with the EGFR-specific tyrosine kinase inhibitor AG1478 significantly increases survival in a rabbit model of mTSS. These data indicate that EGFR signaling is critical for progression of an S. aureus exotoxin-mediated disease and may represent an attractive host target for therapeutics.

Exacerbation of spontaneous autoimmune nephritis following regulatory T cell depletion in B cell lymphoma 2‐interacting mediator knock‐out mice

PubMed Central

Wang, Y. M.; Zhang, G. Y.; Wang, Y.; Hu, M.; Zhou, J. J.; Sawyer, A.; Cao, Q.; Wang, Y.; Zheng, G.; Lee, V. W. S.; Harris, D. C. H.

2017-01-01

Summary Regulatory T cells (Tregs) have been recognized as central mediators for maintaining peripheral tolerance and limiting autoimmune diseases. The loss of Tregs or their function has been associated with exacerbation of autoimmune disease. However, the temporary loss of Tregs in the chronic spontaneous disease model has not been investigated. In this study, we evaluated the role of Tregs in a novel chronic spontaneous glomerulonephritis model of B cell lymphoma 2‐interacting mediator (Bim) knock‐out mice by transient depleting Tregs. Bim is a pro‐apoptotic member of the B cell lymphoma 2 (Bcl‐2) family. Bim knock‐out (Bim–/–) mice fail to delete autoreactive T cells in thymus, leading to chronic spontaneous autoimmune kidney disease. We found that Treg depletion in Bim–/– mice exacerbated the kidney injury with increased proteinuria, impaired kidney function, weight loss and greater histological injury compared with wild‐type mice. There was a significant increase in interstitial infiltrate of inflammatory cells, antibody deposition and tubular damage. Furthermore, the serum levels of cytokines interleukin (IL)−2, IL‐4, IL‐6, IL‐10, IL‐17α, interferon (IFN)‐γ and tumour necrosis factor (TNF)‐α were increased significantly after Treg depletion in Bim–/– mice. This study demonstrates that transient depletion of Tregs leads to enhanced self‐reactive T effector cell function followed by exacerbation of kidney disease in the chronic spontaneous kidney disease model of Bim‐deficient mice. PMID:28152566

Loop III region of platelet-derived growth factor (PDGF) B-chain mediates binding to PDGF receptors and heparin.

PubMed Central

Schilling, D; Reid IV, J D; Hujer, A; Morgan, D; Demoll, E; Bummer, P; Fenstermaker, R A; Kaetzel, D M

1998-01-01

Site-directed mutagenesis of the platelet-derived growth factor (PDGF) B-chain was conducted to determine the importance of cationic amino acid residues (Arg160-Lys161-Lys162; RKK) located within the loop III region in mediating the biological and cell-association properties of the molecule. Binding to both PDGF alpha-and beta-receptors was inhibited by the conversion of all three cationic residues into anionic glutamates (RKK-->EEE), whereas an RKK-->SSS mutant also exhibited a modest loss in affinity for beta-receptors. Replacements with serine at either Arg160 (RKK-->SKK) or at all three positions (RKK-->SSS) had little effect on binding to alpha-receptors. Replacements with either glutamic or serine residues at any of the three positions also resulted in significant inhibition of heparin-binding activity. Furthermore, the RKK-->EEE mutant exhibited decreased association with the cell surface and accumulated in the culture medium as 29-32 kDa forms. Stable transfection of U87 astrocytoma cells with RKK-->EEE mutants of either the A-chain or the B-chain inhibited malignant growth in athymic nude mice. Despite altered receptor-binding activities, each of the loop III mutants retained full mitogenic activity when applied to cultured Swiss 3T3 cells. CD spectrophotometric analysis of the RKK-->EEE mutant revealed a secondary structure indistinguishable from the wild type, with a high degree of beta-sheet structure and random coil content (50% and 43% respectively). These findings indicate an important role of the Arg160-Lys161-Lys162 sequence in mediating the biological and cell-associative activities of the PDGF-BB homodimer, and reveal that the mitogenic activity of PDGF-BB is insufficient to mediate its full oncogenic properties. PMID:9677323

Regeneration of hyaline cartilage by cell-mediated gene therapy using transforming growth factor beta 1-producing fibroblasts.

PubMed

Lee, K H; Song, S U; Hwang, T S; Yi, Y; Oh, I S; Lee, J Y; Choi, K B; Choi, M S; Kim, S J

2001-09-20

Transforming growth factor beta (TGF-beta) has been considered as a candidate for gene therapy of orthopedic diseases. The possible application of cell-mediated TGF-beta gene therapy as a new treatment regimen for degenerative arthritis was investigated. In this study, fibroblasts expressing active TGF-beta 1 were injected into the knee joints of rabbits with artificially made cartilage defects to evaluate the feasibility of this therapy for orthopedic diseases. Two to 3 weeks after the injection there was evidence of cartilage regeneration, and at 4 to 6 weeks the cartilage defect was completely filled with newly grown hyaline cartilage. Histological analyses of the regenerated cartilage suggested that it was well integrated with the adjacent normal cartilage at the sides of the defect and that the newly formed tissue was indeed hyaline cartilage. Our findings suggest that cell-mediated TGF-beta 1 gene therapy may be a novel treatment for orthopedic diseases in which hyaline cartilage damage has occurred.

The Mediator complex and transcription regulation

PubMed Central

Poss, Zachary C.; Ebmeier, Christopher C.

2013-01-01

The Mediator complex is a multi-subunit assembly that appears to be required for regulating expression of most RNA polymerase II (pol II) transcripts, which include protein-coding and most non-coding RNA genes. Mediator and pol II function within the pre-initiation complex (PIC), which consists of Mediator, pol II, TFIIA, TFIIB, TFIID, TFIIE, TFIIF and TFIIH and is approximately 4.0 MDa in size. Mediator serves as a central scaffold within the PIC and helps regulate pol II activity in ways that remain poorly understood. Mediator is also generally targeted by sequence-specific, DNA-binding transcription factors (TFs) that work to control gene expression programs in response to developmental or environmental cues. At a basic level, Mediator functions by relaying signals from TFs directly to the pol II enzyme, thereby facilitating TF-dependent regulation of gene expression. Thus, Mediator is essential for converting biological inputs (communicated by TFs) to physiological responses (via changes in gene expression). In this review, we summarize an expansive body of research on the Mediator complex, with an emphasis on yeast and mammalian complexes. We focus on the basics that underlie Mediator function, such as its structure and subunit composition, and describe its broad regulatory influence on gene expression, ranging from chromatin architecture to transcription initiation and elongation, to mRNA processing. We also describe factors that influence Mediator structure and activity, including TFs, non-coding RNAs and the CDK8 module. PMID:24088064

Regulatory T Cells in Patients with Idiopathic Thrombocytopenic Purpura.

PubMed

Akyol Erikçi, Alev; Karagöz, Bülent; Bilgi, Oğuz

2016-06-05

Immune thrombocytopenic purpura (ITP) is an immune-mediated bleeding disorder in which platelets are opsonized by autoantibodies and destroyed by an Fc receptor-mediated phagocytosis by the reticuloendothelial system within the spleen. Autoimmune processes are also considered in the pathogenesis of this disorder. CD4+CD25+FoxP3+ regulatory T (Treg) cells and CD8+CD28- Treg cells have roles in autoimmune diseases. We investigated these regulatory cells in ITP patients. We included 22 ITP patients and 16 age-matched healthy subjects. CD4+CD25+FoxP3+ Treg cells and CD8+CD28- cells were investigated by three-color flow cytometry. The ratios of these cell populations to total lymphocytes were calculated. Statistical analysis was carried out with the Mann-Whitney U test. CD4+CD25+ Treg cells were 9.69±3.70% and 12.99±5.58% in patients with ITP and controls, respectively. CD4+CD25highFoxP3+ cells were 27.72±19.74% and 27.55±23.98% in ITP patients and controls, respectively. The percentages of both of these cell types were not statistically significant when compared to the control group. We did not find any differences in ratios of CD4+CD25+FoxP3+ Treg cells or CD8+CD28- T cells in lymphocytes between patients and healthy subjects. We conclude that these circulatory cells are not different in ITP, but further studies are needed to explore the putative roles of these regulatory cells.

Growth inhibition mediated by PSP94 or CRISP-3 is prostate cancer cell line specific.

PubMed

Pathak, Bhakti R; Breed, Ananya A; Nakhawa, Vaishali H; Jagtap, Dhanashree D; Mahale, Smita D

2010-09-01

The prostate secretory protein of 94 amino acids (PSP94) has been shown to interact with cysteine-rich secretory protein 3 (CRISP-3) in human seminal plasma. Interestingly, PSP94 expression is reduced or lost in the majority of the prostate tumours, whereas CRISP-3 expression is upregulated in prostate cancer compared with normal prostate tissue. To obtain a better understanding of the individual roles these proteins have in prostate tumourigenesis and the functional relevance of their interaction, we ectopically expressed either PSP94 or CRISP-3 alone or PSP94 along with CRISP-3 in three prostate cell lines (PC3, WPE1-NB26 and LNCaP) and performed growth inhibition assays. Reverse transcription-polymerase chain reaction and Western blot analysis were used to screen prostate cell lines for PSP94 and CRISP-3 expression. Mammalian expression constructs for human PSP94 and CRISP-3 were also generated and the expression, localization and secretion of recombinant protein were assayed by transfection followed by Western blot analysis and immunofluorescence assay. The effect that ectopic expression of PSP94 or CRISP-3 had on cell growth was studied by clonogenic survival assay following transfection. To evaluate the effects of co-expression of the two proteins, stable clones of PC3 that expressed PSP94 were generated. They were subsequently transfected with a CRISP-3 expression construct and subjected to clonogenic survival assay. Our results showed that PSP94 and CRISP-3 could each induce growth inhibition in a cell line specific manner. Although the growth of CRISP-3-positive cell lines was inhibited by PSP94, growth inhibition mediated by CRISP-3 was not affected by the presence or absence of PSP94. This suggests that CRISP-3 may participate in PSP94-independent activities during prostate tumourigenesis.

IL2RG, identified as overexpressed by RNA-seq profiling of pancreatic intraepithelial neoplasia, mediates pancreatic cancer growth

PubMed Central

Ayars, Michael; O’Sullivan, Eileen; Macgregor-Das, Anne; Shindo, Koji; Kim, Haeryoung; Borges, Michael; Yu, Jun; Hruban, Ralph H.; Goggins, Michael

2017-01-01

Pancreatic ductal adenocarcinoma evolves from precursor lesions, the most common of which is pancreatic intraepithelial neoplasia (PanIN). We performed RNA-sequencing analysis of laser capture microdissected PanINs and normal pancreatic duct cells to identify differentially expressed genes between PanINs and normal pancreatic duct, and between low-grade and high-grade PanINs. One of the most highly overexpressed transcripts identified in PanIN is interleukin-2 receptor subunit gamma (IL2RG) encoding the common gamma chain, IL2Rγ. CRISPR-mediated knockout of IL2RG in orthotopically implanted pancreatic cancer cells resulted in attenuated tumor growth in mice and reduced JAK3 expression in orthotopic tumors. These results indicate that IL2Rγ/JAK3 signaling contributes to pancreatic cancer cell growth in vivo. PMID:29137350

Aggressive melanoma cells escape from BMP7-mediated autocrine growth inhibition through coordinated Noggin upregulation

PubMed Central

Hsu, Mei-Yu; Rovinsky, Sherry; Lai, Chiou-Yan; Qasem, Shadi; Liu, Xiaoming; How, Joan; Engelhardt, John F.; Murphy, George F.

2009-01-01

Bone morphogenetic proteins (BMPs) are members of the TGF-β superfamily responsible for mediating a diverse array of cellular functions both during embryogenesis and in adult life. Previously, we reported that upregulation of BMP7 in human melanoma correlates with tumor progression. However, melanoma cells are either inhibited by or become resistant to BMP7 as a function of tumor progression, with normal melanocytes being most susceptible. Herein, real-time quantitative reverse transcriptase-polymerase chain reactions and Western blotting revealed that the expression of BMP antagonist, Noggin, correlates with resistance to BMP7 in advanced melanoma cells. To test the hypothesis that coordinated upregulation of Noggin protects advanced melanoma cells from autocrine inhibition by BMP7, functional expression of Noggin in susceptible melanoma cells was achieved by adenoviral gene transfer. The Noggin-overexpressing cells exhibited a growth advantage in response to subsequent BMP7 transduction in vitro under anchorage-dependent and -independent conditions, in three-dimensional skin reconstructs, as well as in vivo in severe combined immune-deficiency mice. In concordance, Noggin knockdown by lentiviral shRNA confers sensitivity to BMP7-induced growth inhibition in advanced melanoma cells. Our findings suggest that, like TGF-β, BMP7 acts as an autocrine growth inhibitor in melanocytic cells, and that advanced melanoma cells may escape from BMP7-induced inhibition through concomitant aberrant expression of Noggin. PMID:18560367

α -Actinin TvACTN3 of Trichomonas vaginalis is an RNA-binding protein that could participate in its posttranscriptional iron regulatory mechanism.

PubMed

Calla-Choque, Jaeson Santos; Figueroa-Angulo, Elisa Elvira; Ávila-González, Leticia; Arroyo, Rossana

2014-01-01

Trichomonas vaginalis is a sexually transmitted flagellated protist parasite responsible for trichomoniasis. This parasite is dependent on high levels of iron, favoring its growth and multiplication. Iron also differentially regulates some trichomonad virulence properties by unknown mechanisms. However, there is evidence to support the existence of gene regulatory mechanisms at the transcriptional and posttranscriptional levels that are mediated by iron concentration in T. vaginalis. Thus, the goal of this study was to identify an RNA-binding protein in T. vaginalis that interacts with the tvcp4 RNA stem-loop structure, which may participate in a posttranscriptional iron regulatory mechanism mediated by RNA-protein interactions. We performed RNA electrophoretic mobility shift assay (REMSA) and supershift, UV cross-linking, Northwestern blot, and western blot (WB) assays using cytoplasmic protein extracts from T. vaginalis with the tvcp4 RNA hairpin structure as a probe. We identified a 135-kDa protein isolated by the UV cross-linking assays as α-actinin 3 (TvACTN3) by MALDI-TOF-MS that was confirmed by LS-MS/MS and de novo sequencing. TvACTN3 is a cytoplasmic protein that specifically binds to hairpin RNA structures from trichomonads and humans when the parasites are grown under iron-depleted conditions. Thus, TvACTN3 could participate in the regulation of gene expression by iron in T. vaginalis through a parallel posttranscriptional mechanism similar to that of the IRE/IRP system.

α-Actinin TvACTN3 of Trichomonas vaginalis Is an RNA-Binding Protein That Could Participate in Its Posttranscriptional Iron Regulatory Mechanism

PubMed Central

Calla-Choque, Jaeson Santos; Figueroa-Angulo, Elisa Elvira; Ávila-González, Leticia; Arroyo, Rossana

2014-01-01

Trichomonas vaginalis is a sexually transmitted flagellated protist parasite responsible for trichomoniasis. This parasite is dependent on high levels of iron, favoring its growth and multiplication. Iron also differentially regulates some trichomonad virulence properties by unknown mechanisms. However, there is evidence to support the existence of gene regulatory mechanisms at the transcriptional and posttranscriptional levels that are mediated by iron concentration in T. vaginalis. Thus, the goal of this study was to identify an RNA-binding protein in T. vaginalis that interacts with the tvcp4 RNA stem-loop structure, which may participate in a posttranscriptional iron regulatory mechanism mediated by RNA-protein interactions. We performed RNA electrophoretic mobility shift assay (REMSA) and supershift, UV cross-linking, Northwestern blot, and western blot (WB) assays using cytoplasmic protein extracts from T. vaginalis with the tvcp4 RNA hairpin structure as a probe. We identified a 135-kDa protein isolated by the UV cross-linking assays as α-actinin 3 (TvACTN3) by MALDI-TOF-MS that was confirmed by LS-MS/MS and de novo sequencing. TvACTN3 is a cytoplasmic protein that specifically binds to hairpin RNA structures from trichomonads and humans when the parasites are grown under iron-depleted conditions. Thus, TvACTN3 could participate in the regulation of gene expression by iron in T. vaginalis through a parallel posttranscriptional mechanism similar to that of the IRE/IRP system. PMID:24719864

Targeting Sphingosine Kinase Isoforms Effectively Reduces Growth and Survival of Neoplastic Mast Cells With D816V-KIT

PubMed Central

Bandara, Geethani; Muñoz-Cano, Rosa; Tobío, Araceli; Yin, Yuzhi; Komarow, Hirsh D.; Desai, Avanti; Metcalfe, Dean D.; Olivera, Ana

2018-01-01

Mastocytosis is a disorder resulting from an abnormal mast cell (MC) accumulation in tissues that is often associated with the D816V mutation in KIT, the tyrosine kinase receptor for stem cell factor. Therapies available to treat aggressive presentations of mastocytosis are limited, thus exploration of novel pharmacological targets that reduce MC burden is desirable. Since increased generation of the lipid mediator sphingosine-1-phosphate (S1P) by sphingosine kinase (SPHK) has been linked to oncogenesis, we studied the involvement of the two SPHK isoforms (SPHK1 and SPHK2) in the regulation of neoplastic human MC growth. While SPHK2 inhibition prevented entry into the cell cycle in normal and neoplastic human MCs with minimal effect on cell survival, SPHK1 inhibition caused cell cycle arrest in G2/M and apoptosis, particularly in D816V-KIT MCs. This was mediated via activation of the DNA damage response (DDR) cascade, including phosphorylation of the checkpoint kinase 2 (CHK2), CHK2-mediated M-phase inducer phosphatase 3 depletion, and p53 activation. Combination treatment of SPHK inhibitors with KIT inhibitors showed greater growth inhibition of D816V-KIT MCs than either inhibitor alone. Furthermore, inhibition of SPHK isoforms reduced the number of malignant bone marrow MCs from patients with mastocytosis and the growth of D816V-KIT MCs in a xenograft mouse model. Our results reveal a role for SPHK isoforms in the regulation of growth and survival in normal and neoplastic MCs and suggest a regulatory function for SPHK1 in the DDR in MCs with KIT mutations. The findings also suggest that targeting the SPHK/S1P axis may provide an alternative to tyrosine kinase inhibitors, alone or in combination, for the treatment of aggressive mastocytosis and other hematological malignancies associated with the D816V-KIT mutation. PMID:29643855

Targeting Sphingosine Kinase Isoforms Effectively Reduces Growth and Survival of Neoplastic Mast Cells With D816V-KIT.

PubMed

Bandara, Geethani; Muñoz-Cano, Rosa; Tobío, Araceli; Yin, Yuzhi; Komarow, Hirsh D; Desai, Avanti; Metcalfe, Dean D; Olivera, Ana

2018-01-01

Mastocytosis is a disorder resulting from an abnormal mast cell (MC) accumulation in tissues that is often associated with the D816V mutation in KIT, the tyrosine kinase receptor for stem cell factor. Therapies available to treat aggressive presentations of mastocytosis are limited, thus exploration of novel pharmacological targets that reduce MC burden is desirable. Since increased generation of the lipid mediator sphingosine-1-phosphate (S1P) by sphingosine kinase (SPHK) has been linked to oncogenesis, we studied the involvement of the two SPHK isoforms (SPHK1 and SPHK2) in the regulation of neoplastic human MC growth. While SPHK2 inhibition prevented entry into the cell cycle in normal and neoplastic human MCs with minimal effect on cell survival, SPHK1 inhibition caused cell cycle arrest in G2/M and apoptosis, particularly in D816V-KIT MCs. This was mediated via activation of the DNA damage response (DDR) cascade, including phosphorylation of the checkpoint kinase 2 (CHK2), CHK2-mediated M-phase inducer phosphatase 3 depletion, and p53 activation. Combination treatment of SPHK inhibitors with KIT inhibitors showed greater growth inhibition of D816V-KIT MCs than either inhibitor alone. Furthermore, inhibition of SPHK isoforms reduced the number of malignant bone marrow MCs from patients with mastocytosis and the growth of D816V-KIT MCs in a xenograft mouse model. Our results reveal a role for SPHK isoforms in the regulation of growth and survival in normal and neoplastic MCs and suggest a regulatory function for SPHK1 in the DDR in MCs with KIT mutations. The findings also suggest that targeting the SPHK/S1P axis may provide an alternative to tyrosine kinase inhibitors, alone or in combination, for the treatment of aggressive mastocytosis and other hematological malignancies associated with the D816V-KIT mutation.

Melanoma induced immunosuppression is mediated by hematopoietic dysregulation.

PubMed

Kamran, Neha; Li, Youping; Sierra, Maria; Alghamri, Mahmoud S; Kadiyala, Padma; Appelman, Henry D; Edwards, Marta; Lowenstein, Pedro R; Castro, Maria G

2018-01-01

Tumors are associated with expansion of immunosuppressive cells such as tumor associated macrophages (TAMs), regulatory T cells (Tregs) and myeloid derived suppressor cells (MDSCs). These cells promote tumor growth, angiogenesis, metastasis and immune escape. Cancer patients frequently present symptoms such as anemia, leukocytosis and/or cytopenia; associated with poor prognosis. To uncover tumor-mediated hematopoietic abnormalities and identify novel targets that can be harnessed to improve tumor-specific immune responses, we investigated the hematopoietic stem and progenitor cell compartment in melanoma bearing mice. We show that melanoma growth results in expansion of myeloid lineages such as MDSCs, macrophages and DCs along with a reduction in mature RBCs and platelets. Mature B lymphocytes in the blood and BM of melanoma mice were also reduced. Mice bearing melanoma showed extramedullary hematopoiesis in the spleen. Increased expansion of myeloid lineages occurred directly at the level of stem and progenitor cells. The reduction in mature B lymphocytes resulted from a block at the Pro-B cell stage in the bone marrow. Addition of recombinant IL-3 to bone marrow cells resulted in the expansion of committed myeloid progenitors including common myeloid precursors, granulocyte-monocyte precursors and megakaryocyte-erythrocyte precursors. In vivo , IL-3 receptor stimulation in melanoma bearing mice using an IL-3 antibody also resulted in a robust expansion of committed myeloid progenitors and hematopoietic stem cells. Collectively our findings demonstrate that tumor growth plays a pivotal role in reprogramming the host immune system by impacting hematopoiesis directly at the level of stem cell compartment.

Online Self-Regulatory Learning Behaviors as a Mediator in the Relationship between Online Course Perceptions with Achievement

ERIC Educational Resources Information Center

Barnard, Lucy; Paton, Valerie; Lan, William

2008-01-01

Positive perceptions of online course communication and collaboration have been associated with better academic outcomes, while self-regulatory learning behaviors have also been linked to academic achievement and other positive learning outcomes. In the current study, we examined whether self-regulatory learning behaviors may be considered as…

Salt stress differentially affects growth-mediating β-expansins in resistant and sensitive maize (Zea mays L.).

PubMed

Geilfus, Christoph-Martin; Zörb, Christian; Mühling, Karl H

2010-12-01

Salinity mainly reduces shoot growth by the inhibition of cell division and elongation. Expansins loosen plant cell walls. Moreover, the expression of some isoforms is clearly correlated with growth. Effects of salinity on β-expansin transcripts protein abundance were recently reported for different crop species. This study provides a broad analysis of the impact of an 8-day 100mM NaCl stress treatment on the mRNA expression of different maize (Zea mays L.) β-Expansin isoforms using real-time quantitative RT-PCR. The composite β-expansin protein expression was analyzed by western blotting using an anti-peptide antibody raised against a conserved 15-amino-acid region shared by vegetatively expressed β-expansin isoforms. For the first time, changes in β-expansin transcript and protein abundance have been analyzed together with the salinity-induced inhibition of shoot growth. A salt-resistant and a salt-sensitive cultivar were compared in order to elucidate physiological changes. Genotypic differences in the relative concentration of six β-expansin transcripts together with differences in the abundance β-expansin protein are shown in response NaCl stress. In salt-sensitive Lector, reduced β-expansin protein expression was found to correlate positively with reduced shoot growth under stress. A down-regulation of ZmExpB2, ZmExpB6, and ZmExpB8 transcripts possibly contribute to this decrease in protein abundance. In contrast, the maintenance of shoot growth in salt-resistant SR03 might be related to an unaffected abundance of growth-mediating β-expansin proteins in the shoot. Our data suggest that the up-regulation of ZmExpB2, ZmExpB6, and ZmExpB8 may sustain the stable expression of β-expansin protein under conditions of salt stress. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

A feedback regulatory model for RifQ-mediated repression of rifamycin export in Amycolatopsis mediterranei.

PubMed

Lei, Chao; Wang, Jingzhi; Liu, Yuanyuan; Liu, Xinqiang; Zhao, Guoping; Wang, Jin

2018-01-29

Due to the important role of rifamycin in curing tuberculosis infection, the study on rifamycin has never been stopped. Although RifZ, which locates within the rifamycin biosynthetic cluster, has recently been characterized as a pathway-specific regulator for rifamycin biosynthesis, little is known about the regulation of rifamycin export. In this work, we proved that the expression of the rifamycin efflux pump (RifP) was regulated by RifQ, a TetR-family transcriptional regulator. Deletion of rifQ had little impact on bacterial growth, but resulted in improved rifamycin production, which was consistent with the reverse transcription PCR results that RifQ negatively regulated rifP's transcription. With electrophoretic mobility shift assay and DNase I Footprinting assay, RifQ was found to directly bind to the promoter region of rifP, and a typical inverted repeat was identified within the RifQ-protected sequences. The transcription initiation site of rifP was further characterized and found to be upstream of the RifQ binding sites, well explaining the RifQ-mediated repression of rifP's transcription in vivo. Moreover, rifamycin B (the end product of rifamycin biosynthesis) remarkably decreased the DNA binding affinity of RifQ, which led to derepression of rifamycin export, reducing the intracellular concentration of rifamycin B as well as its toxicity against the host. Here, we proved that the export of rifamycin B was repressed by RifQ in Amycolatopsis mediterranei, and the RifQ-mediated repression could be specifically relieved by rifamycin B, the end product of rifamycin biosynthesis, based on which a feedback model was proposed for regulation of rifamycin export. With the findings here, one could improve the antibiotic yield by simply inactivating the negative regulator of the antibiotic transporter.

Transforming growth factor alpha is a critical mediator of radiation lung injury.

PubMed

Chung, Eun Joo; Hudak, Kathryn; Horton, Jason A; White, Ayla; Scroggins, Bradley T; Vaswani, Shiva; Citrin, Deborah

2014-09-01

Radiation fibrosis of the lung is a late toxicity of thoracic irradiation. Epidermal growth factor (EGF) signaling has previously been implicated in radiation lung injury. We hypothesized that TGF-α, an EGF receptor ligand, plays a key role in radiation-induced fibrosis in lung. Mice deficient in transforming growth factor (TGF-α(-/-)) and control C57Bl/6J (C57-WT) mice were exposed to thoracic irradiation in 5 daily fractions of 6 Gy. Cohorts of mice were followed for survival (n ≥ 5 per group) and tissue collection (n = 3 per strain and time point). Collagen accumulation in irradiated lungs was assessed by Masson's trichrome staining and analysis of hydroxyproline content. Cytokine levels in lung tissue were assessed with ELISA. The effects of TGF-α on pneumocyte and fibroblast proliferation and collagen production were analyzed in vitro. Lysyl oxidase (LOX) expression and activity were measured in vitro and in vivo. Irradiated C57-WT mice had a median survival of 24.4 weeks compared to 48.2 weeks for irradiated TGF-α(-/-) mice (P = 0.001). At 20 weeks after irradiation, hydroxyproline content was markedly increased in C57-WT mice exposed to radiation compared to TGF-α(-/-) mice exposed to radiation or unirradiated C57-WT mice (63.0, 30.5 and 37.6 μg/lung, respectively, P = 0.01). C57-WT mice exposed to radiation had dense foci of subpleural fibrosis at 20 weeks after exposure, whereas the lungs of irradiated TGF-α (-/-) mice were largely devoid of fibrotic foci. Lung tissue concentrations of IL-1β, IL-4, TNF-α, TGF-β and EGF at multiple time points after irradiation were similar in C57-WT and TGF-α(-/-) mice. TGF-α in lung tissue of C57-WT mice rose rapidly after irradiation and remained elevated through 20 weeks. TGF-α(-/-) mice had lower basal LOX expression than C57-WT mice. Both LOX expression and LOX activity were increased after irradiation in all mice but to a lesser degree in TGF-α(-/-) mice. Treatment of NIH-3T3 fibroblasts with TGF

Skeletal muscle hypertrophy and regeneration: interplay between the myogenic regulatory factors (MRFs) and insulin-like growth factors (IGFs) pathways.

PubMed

Zanou, Nadège; Gailly, Philippe

2013-11-01

Adult skeletal muscle can regenerate in response to muscle damage. This ability is conferred by the presence of myogenic stem cells called satellite cells. In response to stimuli such as injury or exercise, these cells become activated and express myogenic regulatory factors (MRFs), i.e., transcription factors of the myogenic lineage including Myf5, MyoD, myogenin, and Mrf4 to proliferate and differentiate into myofibers. The MRF family of proteins controls the transcription of important muscle-specific proteins such as myosin heavy chain and muscle creatine kinase. Different growth factors are secreted during muscle repair among which insulin-like growth factors (IGFs) are the only ones that promote both muscle cell proliferation and differentiation and that play a key role in muscle regeneration and hypertrophy. Different isoforms of IGFs are expressed during muscle repair: IGF-IEa, IGF-IEb, or IGF-IEc (also known as mechano growth factor, MGF) and IGF-II. MGF is expressed first and is observed in satellite cells and in proliferating myoblasts whereas IGF-Ia and IGF-II expression occurs at the state of muscle fiber formation. Interestingly, several studies report the induction of MRFs in response to IGFs stimulation. Inversely, IGFs expression may also be regulated by MRFs. Various mechanisms are proposed to support these interactions. In this review, we describe the general process of muscle hypertrophy and regeneration and decipher the interactions between the two groups of factors involved in the process.

Adenosine production by human B cells and B cell–mediated suppression of activated T cells

PubMed Central

Saze, Zenichiro; Schuler, Patrick J.; Hong, Chang-Sook; Cheng, Dongmei; Jackson, Edwin K.

2013-01-01

Antibody-independent role of B cells in modulating T-cell responses is incompletely understood. Freshly isolated or cultured B cells isolated from the peripheral blood of 30 normal donors were evaluated for CD39 and CD73 coexpression, the ability to produce adenosine 5′-monophosphate (AMP) and adenosine (ADO) in the presence of exogenous adenosine triphosphate (ATP) as well as A1, A2A, A2B, and A3 adenosine receptor (ADOR) expression. Human circulating B cells coexpress ectonucleotidases CD39 and CD73, hydrolyze exogenous ATP to 5′-AMP and ADO, and express messenger RNA for A1R, A2AR, and A3R. 2-chloroadenosine inhibited B-cell proliferation and cytokine expression, and only A3R selective antagonist restored B-cell functions. This suggested that B cells use the A3R for autocrine signaling and self-regulation. Mediated effects on B-cell growth ± ADOR antagonists or agonists were tested in carboxyfluorescein diacetate succinimidyl ester assays. In cocultures, resting B cells upregulated functions of CD4+ and CD8+ T cells. However, in vitro–activated B cells downregulated CD73 expression, mainly produced 5′-AMP, and inhibited T-cell proliferation and cytokine production. These B cells acquire the ability to restrict potentially harmful effects of activated T cells. Thus, B cells emerge as a key regulatory component of T cell–B cell interactions, and their dual regulatory activity is mediated by the products of ATP hydrolysis, 5′-AMP, and ADO. PMID:23678003

Progesterone receptor (PR) polyproline domain (PPD) mediates inhibition of epidermal growth factor receptor (EGFR) signaling in non-small cell lung cancer cells.

PubMed

Kawprasertsri, Sornsawan; Pietras, Richard J; Marquez-Garban, Diana C; Boonyaratanakornkit, Viroj

2016-05-01

Recent evidence has suggested a possible role for progesterone receptor (PR) in the progression of non-small cell lung cancer (NSCLC). However, little is known concerning roles of PR in NSCLC. PR contains a polyproline domain (PPD), which directly binds to the SH3 domain of signaling molecules. Because PPD-SH3 interactions are essential for EGFR signaling, we hypothesized that the presence of PR-PPD interfered with EGFR-mediated signaling and cell proliferation. We examined the role of PR-PPD in cell proliferation and signaling by stably expressing PR-B, or PR-B with disrupting mutations in the PPD (PR-BΔSH3), from a tetracycline-regulated promoter in A549 NSCLC cells. PR-B dose-dependently inhibited cell growth in the absence of ligand, and progestin (R5020) treatment further suppressed the growth. Treatment with RU486 abolished PR-B- and R5020-mediated inhibition of cell proliferation. Expression of PR-BΔSH3 and treatment with R5020 or RU486 had no effect on cell proliferation. Furthermore, PR-B expression but not PR-BΔSH3 expression reduced EGF-induced A549 proliferation and activation of ERK1/2, in the absence of ligand. Taken together, our data demonstrated the significance of PR extranuclear signaling through PPD interactions in EGFR-mediated proliferation and signaling in NSCLC. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Role of Flightless-I (Drosophila) homolog in the transcription activation of type I collagen gene mediated by transforming growth factor beta

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lim, Mi-Sun; Jeong, Kwang Won, E-mail: kwjeong@gachon.ac.kr

Highlights: • FLII activates TGFβ-mediated expression of COL1A2 gene. • TGFβ induces the association of FLII with SMAD3 and BRG1 in A549 cells. • FLII is required for the recruitment of SWI/SNF complex and chromatin accessibility to COL1A2 promoter. - Abstract: Flightless-I (Drosophila) homolog (FLII) is a nuclear receptor coactivator that is known to interact with other transcriptional regulators such as the SWI/SNF complex, an ATP-dependent chromatin-remodeling complex, at the promoter or enhancer region of estrogen receptor (ER)-α target genes. However, little is known about the role of FLII during transcription initiation in the transforming growth factor beta (TGFβ)/SMAD-dependent signalingmore » pathway. Here, we demonstrate that FLII functions as a coactivator in the expression of type I collagen gene induced by TGFβ in A549 cells. FLII activates the reporter gene driven by COL1A2 promoter in a dose-dependent manner. Co-expression of GRIP1, CARM1, or p300 did not show any synergistic activation of transcription. Furthermore, the level of COL1A2 expression correlated with the endogenous level of FLII mRNA level. Depletion of FLII resulted in a reduction of TGFβ-induced expression of COL1A2 gene. In contrast, over-expression of FLII caused an increase in the endogenous expression of COL1A2. We also showed that FLII is associated with Brahma-related gene 1 (BRG1) as well as SMAD in A549 cells. Notably, the recruitment of BRG1 to the COL1A2 promoter region was decreased in FLII-depleted A549 cells, suggesting that FLII is required for TGFβ-induced chromatin remodeling, which is carried out by the SWI/SNF complex. Furthermore, formaldehyde-assisted isolation of regulatory elements (FAIRE)-quantitative polymerase chain reaction (qPCR) experiments revealed that depletion of FLII caused a reduction in chromatin accessibility at the COL1A2 promoter. These results suggest that FLII plays a critical role in TGFβ/SMAD-mediated transcription of the COL1A2

RBPJ maintains brain tumor–initiating cells through CDK9-mediated transcriptional elongation

PubMed Central

Xie, Qi; Wu, Qiulian; Kim, Leo; Miller, Tyler E.; Liau, Brian B.; Mack, Stephen C.; Yang, Kailin; Factor, Daniel C.; Fang, Xiaoguang; Huang, Zhi; Zhou, Wenchao; Alazem, Kareem; Wang, Xiuxing; Bernstein, Bradley E.; Bao, Shideng; Rich, Jeremy N.

2016-01-01

Glioblastomas co-opt stem cell regulatory pathways to maintain brain tumor–initiating cells (BTICs), also known as cancer stem cells. NOTCH signaling has been a molecular target in BTICs, but NOTCH antagonists have demonstrated limited efficacy in clinical trials. Recombining binding protein suppressor of hairless (RBPJ) is considered a central transcriptional mediator of NOTCH activity. Here, we report that pharmacologic NOTCH inhibitors were less effective than targeting RBPJ in suppressing tumor growth. While NOTCH inhibitors decreased canonical NOTCH gene expression, RBPJ regulated a distinct profile of genes critical to BTIC stemness and cell cycle progression. RBPJ was preferentially expressed by BTICs and required for BTIC self-renewal and tumor growth. MYC, a key BTIC regulator, bound the RBPJ promoter and treatment with a bromodomain and extraterminal domain (BET) family bromodomain inhibitor decreased MYC and RBPJ expression. Proteomic studies demonstrated that RBPJ binds CDK9, a component of positive transcription elongation factor b (P-TEFb), to target gene promoters, enhancing transcriptional elongation. Collectively, RBPJ links MYC and transcriptional control through CDK9, providing potential nodes of fragility for therapeutic intervention, potentially distinct from NOTCH. PMID:27322055

A scabies mite serpin interferes with complement-mediated neutrophil functions and promotes staphylococcal growth.

PubMed

Swe, Pearl M; Fischer, Katja

2014-06-01

Scabies is a contagious skin disease caused by the parasitic mite Sarcoptes scabiei. The disease is highly prevalent worldwide and known to predispose to secondary bacterial infections, in particular by Streptococcus pyogenes and Staphylococcus aureus. Reports of scabies patients co-infected with methicillin resistant S. aureus (MRSA) pose a major concern for serious down-stream complications. We previously reported that a range of complement inhibitors secreted by the mites promoted the growth of S. pyogenes. Here, we show that a recently characterized mite serine protease inhibitor (SMSB4) inhibits the complement-mediated blood killing of S. aureus. Blood killing of S. aureus was measured in whole blood bactericidal assays, counting viable bacteria recovered after treatment in fresh blood containing active complement and phagocytes, treated with recombinant SMSB4. SMSB4 inhibited the blood killing of various strains of S. aureus including methicillin-resistant and methicillin-sensitive isolates. Staphylococcal growth was promoted in a dose-dependent manner. We investigated the effect of SMSB4 on the complement-mediated neutrophil functions, namely phagocytosis, opsonization and anaphylatoxin release, by flow cytometry and in enzyme linked immuno sorbent assays (ELISA). SMSB4 reduced phagocytosis of S. aureus by neutrophils. It inhibited the deposition of C3b, C4b and properdin on the bacteria surface, but did not affect the depositions of C1q and MBL. SMSB4 also inhibited C5 cleavage as indicated by a reduced C5b-9 deposition. We postulate that SMSB4 interferes with the activation of all three complement pathways by reducing the amount of C3 convertase formed. We conclude that SMSB4 interferes with the complement-dependent killing function of neutrophils, thereby reducing opsonization, phagocytosis and further recruitment of neutrophils to the site of infection. As a consequence secreted scabies mites complement inhibitors, such as SMSB4, provide favorable

Coated Pit-mediated Endocytosis of the Type I Transforming Growth Factor-β (TGF-β) Receptor Depends on a Di-leucine Family Signal and Is Not Required for Signaling*

PubMed Central

Shapira, Keren E.; Gross, Avner; Ehrlich, Marcelo; Henis, Yoav I.

2012-01-01

The roles of transforming growth factor-β (TGF-β) receptor endocytosis in signaling have been investigated in numerous studies, mainly through the use of endocytosis inhibitory treatments, yielding conflicting results. Two potential sources for these discrepancies were the pleiotropic effects of a general blockade of specific internalization pathways and the scarce information on the regulation of the endocytosis of the signal-transducing type I TGF-β receptor (TβRI). Here, we employed extracellularly tagged myc-TβRI (wild type, truncation mutants, and a series of endocytosis-defective and endocytosis-enhanced mutants) to directly investigate the relationship between TβRI endocytosis and signaling. Our findings indicate that TβRI is targeted for constitutive clathrin-mediated endocytosis via a di-leucine (Leu180-Ile181) signal and an acidic cluster motif. Using Smad-dependent transcriptional activation assays and following Smad2/3 nuclear translocation in response to TGF-β stimulation, we show that TβRI endocytosis is dispensable for TGF-β signaling and may play a role in signal termination. Alanine replacement of Leu180-Ile181 led to partial constitutive activation of TβRI, resulting in part from its retention at the plasma membrane and in part from potential alterations of TβRI regulatory interactions in the vicinity of the mutated residues. PMID:22707720

Ferulic Acid Exerts Anti-Angiogenic and Anti-Tumor Activity by Targeting Fibroblast Growth Factor Receptor 1-Mediated Angiogenesis.

PubMed

Yang, Guang-Wei; Jiang, Jin-Song; Lu, Wei-Qin

2015-10-12

Most anti-angiogenic therapies currently being evaluated target the vascular endothelial growth factor (VEGF) pathway; however, the tumor vasculature can acquire resistance to VEGF-targeted therapy by shifting to other angiogenesis mechanisms. Therefore, other therapeutic agents that block non-VEGF angiogenic pathways need to be evaluated. Here, we identified ferulic acid as a novel fibroblast growth factor receptor 1 (FGFR1) inhibitor and a novel agent with potential anti-angiogenic and anti-cancer activities. Ferulic acid demonstrated inhibition of endothelial cell proliferation, migration and tube formation in response to basic fibroblast growth factor 1 (FGF1). In ex vivo and in vivo angiogenesis assays, ferulic acid suppressed FGF1-induced microvessel sprouting of rat aortic rings and angiogenesis. To understand the underlying molecular basis, we examined the effects of ferulic acid on different molecular components and found that ferulic acid suppressed FGF1-triggered activation of FGFR1 and phosphatidyl inositol 3-kinase (PI3K)-protein kinase B (Akt) signaling. Moreover, ferulic acid directly inhibited proliferation and blocked the PI3K-Akt pathway in melanoma cell. In vivo, using a melanoma xenograft model, ferulic acid showed growth-inhibitory activity associated with inhibition of angiogenesis. Taken together, our results indicate that ferulic acid targets the FGFR1-mediated PI3K-Akt signaling pathway, leading to the suppression of melanoma growth and angiogenesis.

Aging and the Mammalian Regulatory Triumvirate

PubMed Central

Rollo, C. David

2010-01-01

A temporal framework linking circadian rhythms and clocks to aging rates identifies a specific window of target of rapamycin (TOR) signaling associated with growth hormone (GH) and insulin-like growth factor (IGF-1) (largely exclusive of insulin) in early sleep. IGF-1 signaling is released by growth hormone secretory peaks and downregulation of IGF-1 binding protein-1 resulting in activation of the mitogen activated protein kinase/extracellular signal response kinase (MAPK/ERK) and phosphoinositide 3-kinase-protein kinase B (PI3K-PKB/Akt) signaling pathways. Phosphorylation of Akt activates TOR which mediates the protein synthesis and growth functions of the GH axis. TOR activity is also associated with downregulated stress resistance, faster aging and reduced lifespan. IGF-1 signaling is terminated by falling GH and upregulation of IGF-1 binding proteins mediated by somatostatin and rising corticosteroids in later sleep. This suppresses PI3K-Akt signaling, thus activating the forkhead transcription factors (FOXOs) and stress-resistance pathways involved in promoting longevity. Thus, sleep appears to encompass both pathways currently identified as most relevant to aging and they toggle successively on the phosphorylation status of Akt. I propose a modified version of Pearl’s rate of living theory emphasizing the hard-wired antagonism of growth (TOR) and stress resistance (FOXO). The sleep association of TOR and FOXO in temporally separated windows and their sequential temporal deployment may change much of the way we think about aging and how to manipulate it. PMID:22396860

The miR-199-dynamin regulatory axis controls receptor-mediated endocytosis.

PubMed

Aranda, Juan F; Canfrán-Duque, Alberto; Goedeke, Leigh; Suárez, Yajaira; Fernández-Hernando, Carlos

2015-09-01

Small non-coding RNAs (microRNAs) are important regulators of gene expression that modulate many physiological processes; however, their role in regulating intracellular transport remains largely unknown. Intriguingly, we found that the dynamin (DNM) genes, a GTPase family of proteins responsible for endocytosis in eukaryotic cells, encode the conserved miR-199a and miR-199b family of miRNAs within their intronic sequences. Here, we demonstrate that miR-199a and miR-199b regulate endocytic transport by controlling the expression of important mediators of endocytosis such as clathrin heavy chain (CLTC), Rab5A, low-density lipoprotein receptor (LDLR) and caveolin-1 (Cav-1). Importantly, miR-199a-5p and miR-199b-5p overexpression markedly inhibits CLTC, Rab5A, LDLR and Cav-1 expression, thus preventing receptor-mediated endocytosis in human cell lines (Huh7 and HeLa). Of note, miR-199a-5p inhibition increases target gene expression and receptor-mediated endocytosis. Taken together, our work identifies a new mechanism by which microRNAs regulate intracellular trafficking. In particular, we demonstrate that the DNM, miR-199a-5p and miR-199b-5p genes act as a bifunctional locus that regulates endocytosis, thus adding an unexpected layer of complexity in the regulation of intracellular trafficking. © 2015. Published by The Company of Biologists Ltd.

The BAFF receptor TACI controls IL-10 production by regulatory B cells and CLL B cells.

PubMed

Saulep-Easton, D; Vincent, F B; Quah, P S; Wei, A; Ting, S B; Croce, C M; Tam, C; Mackay, F

2016-01-01

Interleukin (IL)-10-producing B cells (B10 cells) have emerged as important regulatory elements with immunosuppressive roles. Chronic lymphocytic leukemia (CLL) B cells also secrete IL-10 and share features of B10 cells, suggesting a possible contribution of CLL B cells to immunosuppression in CLL patients. Factors controlling the emergence of B10 cells are not known. B-cell-activating factor of the tumor necrosis factor (TNF) family (BAFF) is critical for B-cell maturation and survival, and is implicated in the development and progression of CLL. We sought to investigate the role of BAFF in the emergence of IL-10-producing regulatory B cells in healthy donors and CLL patients. Here, we report that BAFF signaling promotes IL-10 production by CLL B cells in a mouse model of CLL and in CLL patients. Moreover, BAFF-mediated IL-10 production by normal and CLL B cells is mediated via its receptor transmembrane activator and cyclophilin ligand interactor. Our work uncovered a major targetable pathway important for the generation of regulatory B cells that is detrimental to immunity in CLL.

A Field Experiment Testing the Utility of Regulatory Fit Messages for Promoting Physical Activity.

PubMed

Latimer, Amy E; Rivers, Susan E; Rench, Tara A; Katulak, Nicole A; Hicks, Althea; Hodorowski, Julie Keany; Higgins, E Tory; Salovey, Peter

2008-05-01

Guided by regulatory focus theory, we examined whether messages tailored to individuals' promotion- or prevention-goal orientation (regulatory focus) elicit positive thoughts and feelings about physical activity and increase participation in physical activity. Inactive participants (N = 206) were assigned randomly to receive either promotion-focused or prevention-focused messages encouraging physical activity. Two weeks after message exposure, we assessed participants' thoughts and feelings about physical activity and physical activity behavior. Tailored messages that fit individuals' regulatory focus led to greater physical activity participation and more positive feelings than non-fit messages, particularly in the promotion-focused condition. Furthermore, positive retrospective feelings about physical activity mediated the effects of the tailored messages on behavior. These findings provide support for regulatory focus theory and direction for enhancing the effectiveness of messages encouraging physical activity and other health behaviors.

Electroporation driven delivery of both an IL-12 expressing plasmid and cisplatin synergizes to inhibit B16 melanoma tumor growth through an NK cell mediated tumor killing mechanism.

PubMed

Kim, Ha; Sin, Jeong-Im

2012-11-01

Combined therapy using chemotherapeutic drugs and immunotherapeutics offers some promise for treating patients with cancer. In this study, we evaluated whether cisplatin delivered by intratumoral (IT)-electroporation (EP) might enhance antitumor activity against established B16 melanoma and whether further addition of intramuscular (IM)-EP of IL-12 cDNA to IT-EP of cisplatin might augment antitumor therapeutic activity, with a focus on the underlining antitumor mechanism(s). When tumor (7 mm)-bearing animals were treated locally with cisplatin by IT-EP, they showed tumor growth inhibition significantly more than those without IT-EP. Moreover, IL-12 cDNA delivered by IM-EP was also able to inhibit tumor growth significantly more than control vector delivery. This tumor growth inhibition was mediated by NK cells, but not CD4+ T or CD8+ T cells, as determined by immune cell subset depletion and IFN-γ induction. Moreover, concurrent therapy using IT-EP of cisplatin plus IM-EP of IL-12 cDNA displayed antitumor therapeutic synergy. This therapeutic synergy appeared to be mediated by increased sensitivity of cisplatin-treated tumors to NK cell-mediated tumor killing. Taken together, these data support that cisplatin delivery by IT-EP plus IL-12 gene delivery by IM-EP are more effective at inducing antitumor therapeutic responses through increased sensitivity of cisplatin-treated tumors to NK cell-mediated tumor killing. This combined approach might have some implication for treating melanoma in patients.