Endothelial Notch signalling limits angiogenesis via control of artery formation

PubMed Central

Hasan, Sana S.; Tsaryk, Roman; Lange, Martin; Wisniewski, Laura; Moore, John C.; Lawson, Nathan D.; Wojciechowska, Karolina; Schnittler, Hans; Siekmann, Arndt F.

2017-01-01

Angiogenic sprouting needs to be tightly controlled. It has been suggested that the Notch ligand dll4 expressed in leading tip cells restricts angiogenesis by activating Notch signalling in trailing stalk cells. Here, we show using live imaging in zebrafish that activation of Notch signalling is rather required in tip cells. Notch activation initially triggers expression of the chemokine receptor cxcr4a. This allows for proper tip cell migration and connection to the pre-existing arterial circulation, ultimately establishing functional arterial-venous blood flow patterns. Subsequently, Notch signalling reduces cxcr4a expression, thereby preventing excessive blood vessel growth. Finally, we find that Notch signalling is dispensable for limiting blood vessel growth during venous plexus formation that does not generate arteries. Together, these findings link the role of Notch signalling in limiting angiogenesis to its role during artery formation and provide a framework for our understanding of the mechanisms underlying blood vessel network expansion and maturation. PMID:28714969

Sall1-dependent signals affect Wnt signaling and ureter tip fate to initiate kidney development.

PubMed

Kiefer, Susan M; Robbins, Lynn; Stumpff, Kelly M; Lin, Congxing; Ma, Liang; Rauchman, Michael

2010-09-01

Development of the metanephric kidney depends on precise control of branching of the ureteric bud. Branching events represent terminal bifurcations that are thought to depend on unique patterns of gene expression in the tip compared with the stalk and are influenced by mesenchymal signals. The metanephric mesenchyme-derived signals that control gene expression at the ureteric bud tip are not well understood. In mouse Sall1 mutants, the ureteric bud grows out and invades the metanephric mesenchyme, but it fails to initiate branching despite tip-specific expression of Ret and Wnt11. The stalk-specific marker Wnt9b and the beta-catenin downstream target Axin2 are ectopically expressed in the mutant ureteric bud tips, suggesting that upregulated canonical Wnt signaling disrupts ureter branching in this mutant. In support of this hypothesis, ureter arrest is rescued by lowering beta-catenin levels in the Sall1 mutant and is phenocopied by ectopic expression of a stabilized beta-catenin in the ureteric bud. Furthermore, transgenic overexpression of Wnt9b in the ureteric bud causes reduced branching in multiple founder lines. These studies indicate that Sall1-dependent signals from the metanephric mesenchyme are required to modulate ureteric bud tip Wnt patterning in order to initiate branching.

Regulatory RNAs and the HptB/RetS signalling pathways fine-tune Pseudomonas aeruginosa pathogenesis

PubMed Central

Bordi, Christophe; Lamy, Marie-Cécile; Ventre, Isabelle; Termine, Elise; Hachani, Abderrahman; Fillet, Sandy; Roche, Béatrice; Bleves, Sophie; Méjean, Vincent; Lazdunski, Andrée; Filloux, Alain

2010-01-01

Bacterial pathogenesis often depends on regulatory networks, two-component systems and small RNAs (sRNAs). In Pseudomonas aeruginosa, the RetS sensor pathway downregulates expression of two sRNAs, rsmY and rsmZ. Consequently, biofilm and the Type Six Secretion System (T6SS) are repressed, whereas the Type III Secretion System (T3SS) is activated. We show that the HptB signalling pathway controls biofilm and T3SS, and fine-tunes P. aeruginosa pathogenesis. We demonstrate that RetS and HptB intersect at the GacA response regulator, which directly controls sRNAs production. Importantly, RetS controls both sRNAs, whereas HptB exclusively regulates rsmY expression. We reveal that HptB signalling is a complex regulatory cascade. This cascade involves a response regulator, with an output domain belonging to the phosphatase 2C family, and likely an anti-anti-σ factor. This reveals that the initial input in the Gac system comes from several signalling pathways, and the final output is adjusted by a differential control on rsmY and rsmZ. This is exemplified by the RetS-dependent but HptB-independent control on T6SS. We also demonstrate a redundant action of the two sRNAs on T3SS gene expression, while the impact on pel gene expression is additive. These features underpin a novel mechanism in the fine-tuned regulation of gene expression. PMID:20398205

ERECTA signaling controls Arabidopsis inflorescence architecture through chromatin-mediated activation of PRE1 expression.

PubMed

Cai, Hanyang; Zhao, Lihua; Wang, Lulu; Zhang, Man; Su, Zhenxia; Cheng, Yan; Zhao, Heming; Qin, Yuan

2017-06-01

Flowering plants display a remarkable diversity in inflorescence architecture, and pedicel length is one of the key contributors to this diversity. In Arabidopsis thaliana, the receptor-like kinase ERECTA (ER) mediated signaling pathway plays important roles in regulating inflorescence architecture by promoting cell proliferation. However, the regulating mechanism remains elusive in the pedicel. Genetic interactions between ERECTA signaling and the chromatin remodeling complex SWR1 in the control of inflorescence architecture were studied. Comparative transcriptome analysis was applied to identify downstream components. Chromatin immunoprecipitation and nucleosome occupancy was further investigated. The results indicated that the chromatin remodeler SWR1 coordinates with ERECTA signaling in regulating inflorescence architecture by activating the expression of PRE1 family genes and promoting pedicel elongation. It was found that SWR1 is required for the incorporation of the H2A.Z histone variant into nucleosomes of the whole PRE1 gene family and the ERECTA controlled expression of PRE1 gene family through regulating nucleosome dynamics. We propose that utilization of a chromatin remodeling complex to regulate gene expression is a common theme in developmental control across kingdoms. These findings shed light on the mechanisms through which chromatin remodelers orchestrate complex transcriptional regulation of gene expression in coordination with a developmental cue. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Retrograde Semaphorin-Plexin Signaling Drives Homeostatic Synaptic Plasticity

PubMed Central

Orr, Brian O.; Fetter, Richard D.; Davis, Graeme W.

2017-01-01

Homeostatic signaling systems ensure stable, yet flexible neural activity and animal behavior1–4. Defining the underlying molecular mechanisms of neuronal homeostatic signaling will be essential in order to establish clear connections to the causes and progression of neurological disease. Presynaptic homeostatic plasticity (PHP) is a conserved form of neuronal homeostatic signaling, observed in organisms ranging from Drosophila to human1,5. Here, we demonstrate that Semaphorin2b (Sema2b) is target-derived signal that acts upon presynaptic PlexinB (PlexB) receptors to mediate the retrograde, homeostatic control of presynaptic neurotransmitter release at the Drosophila neuromuscular junction. Sema2b-PlexB signaling regulates the expression of PHP via the cytoplasmic protein Mical and the oxoreductase-dependent control of presynaptic actin6,7. During neural development, Semaphorin-Plexin signaling instructs axon guidance and neuronal morphogenesis8–10. Yet, Semaphorins and Plexins are also expressed in the adult brain11–16. Here we demonstrate that Semaphorin-Plexin signaling controls presynaptic neurotransmitter release. We propose that Sema2b-PlexB signaling is an essential platform for the stabilization of synaptic transmission throughout life. PMID:28953869

Expression of bvg-repressed genes in Bordetella pertussis is controlled by RisA through a novel c-di-GMP signaling pathway

USDA-ARS?s Scientific Manuscript database

The BvgAS two component system of Bordetella pertussis controls virulence factor expression. In addition, BvgAS controls expression of the bvg-repressed genes through the action of the repressor, BvgR. The transcription factor RisA is inhibited by BvgR, and when BvgR is not expressed RisA induces th...

An entomopathogenic bacterium, Xenorhabdus nematophila, suppresses expression of antimicrobial peptides controlled by Toll and Imd pathways by blocking eicosanoid biosynthesis.

PubMed

Hwang, Jihyun; Park, Youngjin; Kim, Yonggyun; Hwang, Jihyun; Lee, Daeweon

2013-07-01

Immune-associated genes of the beet armyworm, Spodoptera exigua, were predicted from 454 pyrosequencing transcripts of hemocytes collected from fifth instar larvae challenged with bacteria. Out of 22,551 contigs and singletons, 36% of the transcripts had at least one significant hit (E-value cutoff of 1e-20) and used to predict immune-associated genes implicated in pattern recognition, prophenoloxidase activation, intracellular signaling, and antimicrobial peptides (AMPs). Immune signaling and AMP genes were further confirmed in their expression patterns in response to different types of microbial challenge. To discriminate the AMP expression signaling between Toll and Imd pathways, RNA interference was applied to specifically knockdown each signal pathway; the separate silencing treatments resulted in differential suppression of AMP genes. An entomopathogenic bacterium, Xenorhabdus nematophila, suppressed expression of most AMP genes controlled by Toll and Imd pathways, while challenge with heat-killed X. nematophila induced expression of all AMPs in experimental larvae. Benzylideneacetone (BZA), a metabolite of X. nematophila, suppressed the AMP gene inductions when it was co-injected with the heat-killed X. nematophila. However, arachidonic acid, a catalytic product of PLA2 , significantly reversed the inhibitory effect of BZA on the AMP gene expression. This study suggests that X. nematophila suppresses AMP production controlled by Toll and Imd pathways by inhibiting eicosanoid biosynthesis in S. exigua. © 2013 Wiley Periodicals, Inc.

Ecdysone triggered PGRP-LC expression controls Drosophila innate immunity.

PubMed

Rus, Florentina; Flatt, Thomas; Tong, Mei; Aggarwal, Kamna; Okuda, Kendi; Kleino, Anni; Yates, Elisabeth; Tatar, Marc; Silverman, Neal

2013-05-29

Throughout the animal kingdom, steroid hormones have been implicated in the defense against microbial infection, but how these systemic signals control immunity is unclear. Here, we show that the steroid hormone ecdysone controls the expression of the pattern recognition receptor PGRP-LC in Drosophila, thereby tightly regulating innate immune recognition and defense against bacterial infection. We identify a group of steroid-regulated transcription factors as well as two GATA transcription factors that act as repressors and activators of the immune response and are required for the proper hormonal control of PGRP-LC expression. Together, our results demonstrate that Drosophila use complex mechanisms to modulate innate immune responses, and identify a transcriptional hierarchy that integrates steroid signalling and immunity in animals.

Wnt signaling inhibits cementoblast differentiation and promotes proliferation.

PubMed

Nemoto, Eiji; Koshikawa, Yohei; Kanaya, Sousuke; Tsuchiya, Masahiro; Tamura, Masato; Somerman, Martha J; Shimauchi, Hidetoshi

2009-05-01

Cementoblasts, tooth root lining cells, are responsible for laying down cementum on the root surface, a process that is indispensable for establishing a functional periodontal ligament. Cementoblasts share phenotypical features with osteoblasts. Wnt signaling has been implicated in increased bone formation by controlling mesenchymal stem cell or osteoblastic cell functions; however the role of Wnt signaling on cementogenesis has not been examined. In this study, we have identified a consistent expression profile of Wnt signaling molecules in cementoblasts, in vitro by RT-PCR. Exposure of cells to LiCl, which promotes canonical Wnt signaling by inhibiting GSK-3beta, increased beta-catenin nuclear translocation and up-regulated the transcriptional activity of a canonical Wnt-responsive promoters, suggesting that an endogenous canonical Wnt pathway functions in cementoblasts. Activation of endogenous canonical Wnt signaling with LiCl suppressed alkaline phosphatase (ALP) activity and expression of genes associated with cementum function; ALP, bone sialoprotein (BSP), and osteocalcin (OCN). Exposure to Wnt3a, as a representative canonical Wnt member, also inhibited the expression of ALP, BSP, and OCN gene. This effect was accompanied by decreased gene expression of Runx2 and Osterix and by increased gene expression of lymphoid enhancer factor-1. Pretreatment with Dickkopf (Dkk)-1, a potent canonical Wnt antagonist, which binds to a low-density lipoprotein-receptor-related protein (LRP)-5/6 co-receptor, attenuated the suppressive effects of Wnt3a on mRNA expression of Runx2 and OCN on cementoblasts. These findings suggest that canonical Wnt signaling inhibits cementoblast differentiation via regulation of expression of selective transcription factors. Wnt3a also increased the expression of cyclin D1, known as a cell cycle regulator, as well as cell proliferation. In conclusion, these observations suggest that Wnt signaling inhibits cementoblast differentiation and promotes cell proliferation. Elucidating the role of Wnt in controlling cementoblast function will provide new tools needed to improve on existing periodontal regeneration therapies.

Hepatic Expression of Adenovirus 36 E4ORF1 Improves Glycemic Control and Promotes Glucose Metabolism Through AKT Activation

PubMed Central

McMurphy, Travis B.; Huang, Wei; Xiao, Run; Liu, Xianglan; Dhurandhar, Nikhil V.

2017-01-01

Considering that impaired proximal insulin signaling is linked with diabetes, approaches that enhance glucose disposal independent of insulin signaling are attractive. In vitro data indicate that the E4ORF1 peptide derived from human adenovirus 36 (Ad36) interacts with cells from adipose tissue, skeletal muscle, and liver to enhance glucose disposal, independent of proximal insulin signaling. Adipocyte-specific expression of Ad36E4ORF1 improves hyperglycemia in mice. To determine the hepatic interaction of Ad36E4ORF1 in enhancing glycemic control, we expressed E4ORF1 of Ad36 or Ad5 or fluorescent tag alone by using recombinant adeno-associated viral vector in the liver of three mouse models. In db/db or diet-induced obesity (DIO) mice, hepatic expression of Ad36E4ORF1 but not Ad5E4ORF1 robustly improved glycemic control. In normoglycemic wild-type mice, hepatic expression of Ad36E4ORF1 lowered nonfasting blood glucose at a high dose of expression. Of note, Ad36E4ORF1 significantly reduced insulin levels in db/db and DIO mice. The improvement in glycemic control was observed without stimulation of the proximal insulin signaling pathway. Collectively, these data indicate that Ad36E4ORF1 is not a typical sensitizer, mimetic, or secretagogue of insulin. Instead, it may have insulin-sparing action, which seems to reduce the need for insulin and, hence, to reduce insulin levels. PMID:27903748

Hepatic Expression of Adenovirus 36 E4ORF1 Improves Glycemic Control and Promotes Glucose Metabolism Through AKT Activation.

PubMed

McMurphy, Travis B; Huang, Wei; Xiao, Run; Liu, Xianglan; Dhurandhar, Nikhil V; Cao, Lei

2017-02-01

Considering that impaired proximal insulin signaling is linked with diabetes, approaches that enhance glucose disposal independent of insulin signaling are attractive. In vitro data indicate that the E4ORF1 peptide derived from human adenovirus 36 (Ad36) interacts with cells from adipose tissue, skeletal muscle, and liver to enhance glucose disposal, independent of proximal insulin signaling. Adipocyte-specific expression of Ad36E4ORF1 improves hyperglycemia in mice. To determine the hepatic interaction of Ad36E4ORF1 in enhancing glycemic control, we expressed E4ORF1 of Ad36 or Ad5 or fluorescent tag alone by using recombinant adeno-associated viral vector in the liver of three mouse models. In db/db or diet-induced obesity (DIO) mice, hepatic expression of Ad36E4ORF1 but not Ad5E4ORF1 robustly improved glycemic control. In normoglycemic wild-type mice, hepatic expression of Ad36E4ORF1 lowered nonfasting blood glucose at a high dose of expression. Of note, Ad36E4ORF1 significantly reduced insulin levels in db/db and DIO mice. The improvement in glycemic control was observed without stimulation of the proximal insulin signaling pathway. Collectively, these data indicate that Ad36E4ORF1 is not a typical sensitizer, mimetic, or secretagogue of insulin. Instead, it may have insulin-sparing action, which seems to reduce the need for insulin and, hence, to reduce insulin levels. © 2017 by the American Diabetes Association.

Detection and inhibition of bacterial cell-cell communication.

PubMed

Rice, Scott A; McDougald, Diane; Givskov, Michael; Kjelleberg, Staffan

2008-01-01

Bacteria communicate with other members of their community through the secretion and perception of small chemical cues or signals. The recognition of a signal normally leads to the expression of a large suite of genes, which in some bacteria are involved in the regulation of virulence factors, and as a result, these signaling compounds are key regulatory factors in many disease processes. Thus, it is of interest when studying pathogens to understand the mechanisms used to control the expression of virulence genes so that strategies might be devised for the control of those pathogens. Clearly, the ability to interfere with this process of signaling represents a novel approach for the treatment of bacterial infections. There is a broad range of compounds that bacteria can use for signaling purposes, including fatty acids, peptides, N-acylated homoserine lactones, and the signals collectively called autoinducer 2 (AI-2). This chapter will focus on the latter two signaling systems as they are present in a range of medically relevant bacteria, and here we describe assays for determining whether an organism produces a particular signal and assays that can be used to identify inhibitors of the signaling cascade. Lastly, the signal detection and inhibition assays will be directly linked to the expression of virulence factors of specific pathogens.

Transcriptome Wide Annotation of Eukaryotic RNase III Reactivity and Degradation Signals

PubMed Central

Gagnon, Jules; Lavoie, Mathieu; Catala, Mathieu; Malenfant, Francis; Elela, Sherif Abou

2015-01-01

Detection and validation of the RNA degradation signals controlling transcriptome stability are essential steps for understanding how cells regulate gene expression. Here we present complete genomic and biochemical annotations of the signals required for RNA degradation by the dsRNA specific ribonuclease III (Rnt1p) and examine its impact on transcriptome expression. Rnt1p cleavage signals are randomly distributed in the yeast genome, and encompass a wide variety of sequences, indicating that transcriptome stability is not determined by the recurrence of a fixed cleavage motif. Instead, RNA reactivity is defined by the sequence and structural context in which the cleavage sites are located. Reactive signals are often associated with transiently expressed genes, and their impact on RNA expression is linked to growth conditions. Together, the data suggest that Rnt1p reactivity is triggered by malleable RNA degradation signals that permit dynamic response to changes in growth conditions. PMID:25680180

BMP signaling is required for development of the ciliary body.

PubMed

Zhao, Shulei; Chen, Qin; Hung, Fang-Cheng; Overbeek, Paul A

2002-10-01

The ciliary body in the eye secretes aqueous humor and glycoproteins of the vitreous body and maintains the intraocular pressure. The ciliary muscle controls the shape of the lens through the ciliary zonules to focus the image onto the retina. During embryonic development, the ciliary epithelium is derived from the optic vesicle, but the molecular signals that control morphogenesis of the ciliary body are unknown. We report that lens-specific expression of a transgenic protein, Noggin, can block BMP signaling in the mouse eye and result in failure in formation of the ciliary processes. Co-expression of transgenic BMP7 restores normal development of the ciliary epithelium. Ectopic expression of Noggin also promotes differentiation of retinal ganglion cells. These results indicate that BMP signaling is required for development of the ciliary body and may also play a role in regulation of neuronal differentiation in the developing eye.

[Differentially expressed genes of cell signal transduction associated with benzene poisoning by cDNA microarray].

PubMed

Wang, Hong; Bi, Yongyi; Tao, Ning; Wang, Chunhong

2005-08-01

To detect the differential expression of cell signal transduction genes associated with benzene poisoning, and to explore the pathogenic mechanisms of blood system damage induced by benzene. Peripheral white blood cell gene expression profile of 7 benzene poisoning patients, including one aplastic anemia, was determined by cDNA microarray. Seven chips from normal workers were served as controls. Cluster analysis of gene expression profile was performed. Among the 4265 target genes, 176 genes associated with cell signal transduction were differentially expressed. 35 up-regulated genes including PTPRC, STAT4, IFITM1 etc were found in at least 6 pieces of microarray; 45 down-regulated genes including ARHB, PPP3CB, CDC37 etc were found in at least 5 pieces of microarray. cDNA microarray technology is an effective technique for screening the differentially expressed genes of cell signal transduction. Disorder in cell signal transduction may play certain role in the pathogenic mechanism of benzene poisoning.

Expression of the JAK/STAT Signaling Pathway in Bullous Pemphigoid and Dermatitis Herpetiformis

PubMed Central

Wozniacka, A.; Waszczykowska, E.; Zebrowska, A.

2017-01-01

A family of eleven proteins comprises the Janus kinases (JAK) and signal transducers and activators of transcription (STAT) signaling pathway, which enables transduction of signal from cytokine receptor to the nucleus and activation of transcription of target genes. Irregular functioning of the cascade may contribute to pathogenesis of autoimmune diseases; however, there are no reports concerning autoimmune bullous diseases yet to be published. The aim of this study was to evaluate the expression of proteins constituting the JAK/STAT signaling pathway in skin lesions and perilesional area in dermatitis herpetiformis (DH) and bullous pemphigoid (BP), as well as in the control group. Skin biopsies were collected from 21 DH patients, from 20 BP patients, and from 10 healthy volunteers. The localization and expression of selected STAT and JAK proteins were examined by immunohistochemistry and immunoblotting. We found significantly higher expression of JAK/STAT proteins in skin lesions in patients with BP and DH, in comparison to perilesional skin and the control group, which may be related to proinflammatory cytokine network and induction of inflammatory infiltrate in tissues. Our findings suggest that differences in the JAK and STAT expression may be related to distinct cytokines activating them and mediating neutrophilic and/or eosinophilic infiltrate. PMID:29203970

Intercellular and intracellular signalling systems that globally control the expression of virulence genes in plant pathogenic bacteria.

PubMed

Ham, Jong Hyun

2013-04-01

Plant pathogenic bacteria utilize complex signalling systems to control the expression of virulence genes at the cellular level and within populations. Quorum sensing (QS), an important intercellular communication mechanism, is mediated by different types of small molecules, including N-acyl homoserine lactones (AHLs), fatty acids and small proteins. AHL-mediated signalling systems dependent on the LuxI and LuxR family proteins play critical roles in the virulence of a wide range of Gram-negative plant pathogenic bacteria belonging to the Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria. Xanthomonas spp. and Xylella fastidiosa, members of the Gammaproteobacteria, however, possess QS systems that are mediated by fatty acid-type diffusible signal factors (DSFs). Recent studies have demonstrated that Ax21, a 194-amino-acid protein in Xanthomonas oryzae pv. oryzae, plays dual functions in activating a rice innate immune pathway through binding to the rice XA21 pattern recognition receptor and in regulating bacterial virulence and biofilm formation as a QS signal molecule. In xanthomonads, DSF-mediated QS systems are connected with the signalling pathways mediated by cyclic diguanosine monophosphate (c-di-GMP), which functions as a second messenger for the control of virulence gene expression in these bacterial pathogens. © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

Stable transformation of Pleurotus ostreatus to hygromycin B resistance using Lentinus edodes GPD expression signals.

PubMed

Irie, T; Honda, Y; Hirano, T; Sato, T; Enei, H; Watanabe, T; Kuwahara, M

2001-09-01

It was reported that Pleurotus ostreatus was transformed unstably using recombinant plasmids containing a hygromycin B phosphotransferase gene (hph) under the control of Aspergillus nidulans expression signals, and that the plasmids were maintained extrachromosomally in the transformants. Here we report a stable and integrative transformation of the fungus to hygromycin B resistance, using a recombinant hph fused with Lentinus edodes glyceraldehyde-3-phosphate dehydrogenase expression signals. Restriction-enzyme-mediated integration (REMI) was also tried and increased the transformation efficiency about ten-fold.

Wnt Signaling Cross-Talks with JH Signaling by Suppressing Met and gce Expression

PubMed Central

Abdou, Mohamed; Peng, Cheng; Huang, Jianhua; Zyaan, Ola; Wang, Sheng; Li, Sheng; Wang, Jian

2011-01-01

Juvenile hormone (JH) plays key roles in controlling insect growth and metamorphosis. However, relatively little is known about the JH signaling pathways. Until recent years, increasing evidence has suggested that JH modulates the action of 20-hydroxyecdysone (20E) by regulating expression of broad (br), a 20E early response gene, through Met/Gce and Kr-h1. To identify other genes involved in JH signaling, we designed a novel Drosophila genetic screen to isolate mutations that derepress JH-mediated br suppression at early larval stages. We found that mutations in three Wnt signaling negative regulators in Drosophila, Axin (Axn), supernumerary limbs (slmb), and naked cuticle (nkd), caused precocious br expression, which could not be blocked by exogenous JHA. A similar phenotype was observed when armadillo (arm), the mediator of Wnt signaling, was overexpressed. qRT-PCR revealed that Met, gce and Kr-h1expression was suppressed in the Axn, slmb and nkd mutants as well as in arm gain-of-function larvae. Furthermore, ectopic expression of gce restored Kr-h1 expression but not Met expression in the arm gain-of-function larvae. Taken together, we conclude that Wnt signaling cross-talks with JH signaling by suppressing transcription of Met and gce, genes that encode for putative JH receptors. The reduced JH activity further induces down-regulation of Kr-h1expression and eventually derepresses br expression in the Drosophila early larval stages. PMID:22087234

TGFβ signaling supports survival and metastasis of endometrial cancer cells

PubMed Central

Lei, XiuFen; Wang, Long; Yang, Junhua; Sun, Lu-Zhe

2009-01-01

The association of mutation of the transforming growth factor beta (TGFβ) type II receptor (RII) with microsatellite instability revealed a significant molecular mechanism of tumorigenesis and tumor progression in gastrointestinal carcinomas with DNA replication error. However, mutation of RII is rare in other types of carcinomas with microsatellite instability including endometrial adenocarcinoma suggesting that TGFβ receptor signaling may be necessary for tumor progression. To test this hypothesis, we abrogated TGFβ signaling with ectopic expression of a dominant-negative RII (DNRII) in human endometrial carcinoma HEC-1-A cells with microsatellite instability. Our study showed that over-expression of DNRII blocked the TGFβ signaling, inhibited anchorage-dependent and -independent growth, and stimulated apoptosis in vitro. Interestingly, the expression of DNRII expression showed little effect on tumor growth of subcutaneously inoculated cells in vivo. On the other hand, the DNRII cells showed more epithelial features whereas the control cells showed more mesenchymal features suggesting a reversal of autocrine TGFβ-induced epithelial–mesenchymal transition (EMT). Consistent with these findings, DNRII cells were much less migratory and invasive in vitro and metastatic in vivo than the control cells. Therefore, an intact TGFβ signaling pathway appears necessary for the metastatic phenotypes of this carcinoma model. PMID:20622970

Overactivation of hedgehog signaling alters development of the ovarian vasculature in mice.

PubMed

Ren, Yi; Cowan, Robert G; Migone, Fernando F; Quirk, Susan M

2012-06-01

The hedgehog (HH) signaling pathway is critical for ovarian function in Drosophila, but its role in the mammalian ovary has not been defined. Previously, expression of a dominant active allele of the HH signal transducer protein smoothened (SMO) in Amhr2(cre/+)SmoM2 mice caused anovulation in association with a lack of smooth muscle in the theca of developing follicles. The current study examined events during the first 2 wk of life in Amhr2(cre/+)SmoM2 mice to gain insight into the cause of anovulation. Expression of transcriptional targets of HH signaling, Gli1, Ptch1, and Hhip, which are used as measures of pathway activity, were elevated during the first several days of life in Amhr2(cre/+)SmoM2 mice compared to controls but were similar to controls in older mice. Microarray analysis showed that genes with increased expression in 2-day-old mutants compared to controls were enriched for the processes of vascular and tube development and steroidogenesis. The density of platelet endothelial cell adhesion molecule (PECAM)-labeled endothelial tubes was increased in the cortex of newborn ovaries of mutant mice. Costaining of preovulatory follicles for PECAM and smooth muscle actin showed that muscle-type vascular support cells are deficient in theca of mutant mice. Expression of genes for steroidogenic enzymes that are normally expressed in the fetal adrenal gland were elevated in newborn ovaries of mutant mice. In summary, overactivation of HH signaling during early life alters gene expression and vascular development and this is associated with the lifelong development of anovulatory follicles in which the thecal vasculature fails to mature appropriately.

Overactivation of Hedgehog Signaling Alters Development of the Ovarian Vasculature in Mice1

PubMed Central

Ren, Yi; Cowan, Robert G.; Migone, Fernando F.; Quirk, Susan M.

2012-01-01

ABSTRACT The hedgehog (HH) signaling pathway is critical for ovarian function in Drosophila, but its role in the mammalian ovary has not been defined. Previously, expression of a dominant active allele of the HH signal transducer protein smoothened (SMO) in Amhr2cre/+SmoM2 mice caused anovulation in association with a lack of smooth muscle in the theca of developing follicles. The current study examined events during the first 2 wk of life in Amhr2cre/+SmoM2 mice to gain insight into the cause of anovulation. Expression of transcriptional targets of HH signaling, Gli1, Ptch1, and Hhip, which are used as measures of pathway activity, were elevated during the first several days of life in Amhr2cre/+SmoM2 mice compared to controls but were similar to controls in older mice. Microarray analysis showed that genes with increased expression in 2-day-old mutants compared to controls were enriched for the processes of vascular and tube development and steroidogenesis. The density of platelet endothelial cell adhesion molecule (PECAM)-labeled endothelial tubes was increased in the cortex of newborn ovaries of mutant mice. Costaining of preovulatory follicles for PECAM and smooth muscle actin showed that muscle-type vascular support cells are deficient in theca of mutant mice. Expression of genes for steroidogenic enzymes that are normally expressed in the fetal adrenal gland were elevated in newborn ovaries of mutant mice. In summary, overactivation of HH signaling during early life alters gene expression and vascular development and this is associated with the lifelong development of anovulatory follicles in which the thecal vasculature fails to mature appropriately. PMID:22402963

ABA signaling in stress-response and seed development.

PubMed

Nakashima, Kazuo; Yamaguchi-Shinozaki, Kazuko

2013-07-01

KEY MESSAGE : We review the recent progress on ABA signaling, especially ABA signaling for ABA-dependent gene expression, including the AREB/ABF regulon, SnRK2 protein kinase, 2C-type protein phosphatases and ABA receptors. Drought negatively impacts plant growth and the productivity of crops. Drought causes osmotic stress to organisms, and the osmotic stress causes dehydration in plant cells. Abscisic acid (ABA) is produced under osmotic stress conditions, and it plays an important role in the stress response and tolerance of plants. ABA regulates many genes under osmotic stress conditions. It also regulates gene expression during seed development and germination. The ABA-responsive element (ABRE) is the major cis-element for ABA-responsive gene expression. ABRE-binding protein (AREB)/ABRE-binding factor (ABF) transcription factors (TFs) regulate ABRE-dependent gene expression. Other TFs are also involved in ABA-responsive gene expression. SNF1-related protein kinases 2 are the key regulators of ABA signaling including the AREB/ABF regulon. Recently, ABA receptors and group A 2C-type protein phosphatases were shown to govern the ABA signaling pathway. Moreover, recent studies have suggested that there are interactions between the major ABA signaling pathway and other signaling factors in stress-response and seed development. The control of the expression of ABA signaling factors may improve tolerance to environmental stresses.

Hypoxic regulation of the expression of genes encoded estrogen related proteins in U87 glioma cells: eff ect of IRE1 inhibition.

PubMed

Minchenko, D O; Riabovol, O O; Ratushna, O O; Minchenko, O H

2017-01-01

The aim of the present study was to examine the effect of inhibition of endoplasmic reticulum stress signaling, mediated by IRE1 (inositol requiring enzyme 1), which is a central mediator of the unfolded protein response on the expression of genes encoded estrogen related proteins (NRIP1/RIP140, TRIM16/EBBP, ESRRA/NR3B1, FAM162A/E2IG5, PGRMC2/PMBP, and SLC39A6/LIV-1) and their hypoxic regulation in U87 glioma cells for evaluation of their possible significance in the control of glioma cells proliferation. The expression of NRIP1, EBBP, ESRRA, E2IG5, PGRMC2, and SLC39A6 genes in U87 glioma cells, transfected by empty vector pcDNA3.1 (control) and cells without IRE1 signaling enzyme function (transfected by dnIRE1) upon hypoxia, was studied by a quantitative polymerase chain reaction. Inhibition of both enzymatic activities (kinase and endoribonuclease) of IRE1 signaling enzyme function up-regulates the expression of EBBP, E2IG5, PGRMC2, and SLC39A6 genes is in U87 glioma cells in comparison with the control glioma cells, with more significant changes for E2IG5 and PGRMC2 genes. At the same time, the expression of NRIP1 and ESRRA genes is strongly down-regulated in glioma cells upon inhibition of IRE1. We also showed that hypoxia increases the expression of E2IG5, PGRMC2, and EBBP genes and decreases NRIP1 and ESRRA genes expression in control glioma cells. Furthermore, the inhibition of IRE1 in U87 glioma cells decreases the eff ect of hypoxia on the expression of E2IG5 and PGRMC2 genes, eliminates hypoxic regulation of NRIP1 gene, and enhances the sensitivity of ESRRA gene to hypoxic condition. Furthermore, the expression of SLC39A6 gene is resistant to hypoxia in both the glioma cells with and without IRE1 signaling enzyme function. Results of this investigation demonstrate that inhibition of IRE1 signaling enzyme function affects the expression of NRIP1, EBBP, ESRRA, E2IG5, PGRMC2, and SLC39A6 genes in U87 glioma cells in gene specific manner and these changes possibly contribute to the suppression of the cell proliferation. Most of these genes are regulated by hypoxia and preferentially through IRE1 signaling pathway of endoplasmic reticulum stress.

A portable expression resource for engineering cross-species genetic circuits and pathways

PubMed Central

Kushwaha, Manish; Salis, Howard M.

2015-01-01

Genetic circuits and metabolic pathways can be reengineered to allow organisms to process signals and manufacture useful chemicals. However, their functions currently rely on organism-specific regulatory parts, fragmenting synthetic biology and metabolic engineering into host-specific domains. To unify efforts, here we have engineered a cross-species expression resource that enables circuits and pathways to reuse the same genetic parts, while functioning similarly across diverse organisms. Our engineered system combines mixed feedback control loops and cross-species translation signals to autonomously self-regulate expression of an orthogonal polymerase without host-specific promoters, achieving nontoxic and tuneable gene expression in diverse Gram-positive and Gram-negative bacteria. Combining 50 characterized system variants with mechanistic modelling, we show how the cross-species expression resource's dynamics, capacity and toxicity are controlled by the control loops' architecture and feedback strengths. We also demonstrate one application of the resource by reusing the same genetic parts to express a biosynthesis pathway in both model and non-model hosts. PMID:26184393

Tumor necrosis factor-alpha activates signal transduction in hypothalamus and modulates the expression of pro-inflammatory proteins and orexigenic/anorexigenic neurotransmitters.

PubMed

Amaral, Maria E; Barbuio, Raquel; Milanski, Marciane; Romanatto, Talita; Barbosa, Helena C; Nadruz, Wilson; Bertolo, Manoel B; Boschero, Antonio C; Saad, Mario J A; Franchini, Kleber G; Velloso, Licio A

2006-07-01

Tumor necrosis factor-alpha (TNF-alpha) is known to participate in the wastage syndrome that accompanies cancer and severe infectious diseases. More recently, a role for TNF-alpha in the pathogenesis of type 2 diabetes mellitus and obesity has been shown. Much of the regulatory action exerted by TNF-alpha upon the control of energy stores depends on its action on the hypothalamus. In this study, we show that TNF-alpha activates canonical pro-inflammatory signal transduction pathways in the hypothalamus of rats. These signaling events lead to the transcriptional activation of an early responsive gene and to the induction of expression of cytokines and a cytokine responsive protein such as interleukin-1beta, interleukin-6, interleukin-10 and suppressor of cytokine signalling-3, respectively. In addition, TNF-alpha induces the expression of neurotransmitters involved in the control of feeding and thermogenesis. Thus, TNF-alpha may act directly in the hypothalamus inducing a pro-inflammatory response and the modulation of expression of neurotransmitters involved in energy homeostasis.

Activation of the GP130-STAT3 axis and its potential implications in nonalcoholic fatty liver disease

PubMed Central

Min, Hae-Ki; Mirshahi, Faridoddin; Verdianelli, Aurora; Pacana, Tommy; Patel, Vaishali; Park, Chun-Geon; Choi, Aejin; Lee, Jeong-Hoon; Park, Chung-Berm; Ren, Shunlin

2015-01-01

The status of the GP130-STAT3 signaling pathway in humans with nonalcoholic fatty liver disease (NAFLD) and its relevance to disease pathogenesis are unknown. The expression of the gp130-STAT3 axis and gp130 cytokine receptors were studied in subjects with varying phenotypes of NAFLD including nonalcoholic steatohepatitis (NASH) and compared with lean and weight-matched controls without NAFLD. Gp130 and its downstream signaling element (Tyk2 and STAT3) expression were inhibited in obese controls whereas they were increased in NAFLD. IL-6 levels were increased in NASH and correlated with gp130 expression (P < 0.01). Palmitate inhibited gp130-STAT3 expression and signaling. IL-6 and palmitate inhibited hepatic insulin signaling via STAT3-dependent and independent mechanisms, respectively. STAT3 overexpression reversed palmitate-induced lipotoxicity by increasing autophagy (ATG7) and decreasing endoplasmic reticulum stress. These data demonstrate that the STAT3 pathway is activated in NAFLD and can worsen insulin resistance while protecting against other lipotoxic mechanisms of disease pathogenesis. PMID:25747354

MyD88-dependent dendritic and epithelial cell crosstalk orchestrates immune responses to allergens.

PubMed

Thomas, S Y; Whitehead, G S; Takaku, M; Ward, J M; Xu, X; Nakano, K; Lyons-Cohen, M R; Nakano, H; Gowdy, K M; Wade, P A; Cook, D N

2018-05-01

Sensitization to inhaled allergens is dependent on activation of conventional dendritic cells (cDCs) and on the adaptor molecule, MyD88. However, many cell types in the lung express Myd88, and it is unclear how signaling in these different cell types reprograms cDCs and leads to allergic inflammation of the airway. By combining ATAC-seq with RNA profiling, we found that MyD88 signaling in cDCs maintained open chromatin at select loci even at steady state, allowing genes to be rapidly induced during allergic sensitization. A distinct set of genes related to metabolism was indirectly controlled in cDCs through MyD88 signaling in airway epithelial cells (ECs). In mouse models of asthma, Myd88 expression in ECs was critical for eosinophilic inflammation, whereas Myd88 expression in cDCs was required for Th17 cell differentiation and consequent airway neutrophilia. Thus, both cell-intrinsic and cell-extrinsic MyD88 signaling controls gene expression in cDCs and orchestrates immune responses to inhaled allergens.

The Importance of NADPH Oxidases and Redox Signaling in Angiogenesis

PubMed Central

Prieto-Bermejo, Rodrigo; Hernández-Hernández, Angel

2017-01-01

Eukaryotic cells have to cope with the constant generation of reactive oxygen species (ROS). Although the excessive production of ROS might be deleterious for cell biology, there is a plethora of evidence showing that moderate levels of ROS are important for the control of cell signaling and gene expression. The family of the nicotinamide adenine dinucleotide phosphate oxidases (NADPH oxidases or Nox) has evolved to produce ROS in response to different signals; therefore, they fulfil a central role in the control of redox signaling. The role of NADPH oxidases in vascular physiology has been a field of intense study over the last two decades. In this review we will briefly analyze how ROS can regulate signaling and gene expression. We will address the implication of NADPH oxidases and redox signaling in angiogenesis, and finally, the therapeutic possibilities derived from this knowledge will be discussed. PMID:28505091

Participation of ghrelin signalling in the reciprocal regulation of hypothalamic NPY/POMC-mediated appetite control in amphetamine-treated rats.

PubMed

Yu, Ching-Han; Chu, Shu-Chen; Chen, Pei-Ni; Hsieh, Yih-Shou; Kuo, Dong-Yih

2017-06-01

Hypothalamic neuropeptide Y (NPY) and proopiomelanocortin (POMC) have been documented to participate in amphetamine (AMPH)-induced appetite suppression. This study investigated whether ghrelin signalling is associated with changes in NPY/POMC-mediated appetite control. Rats were given AMPH daily for four days, and changes in food intake, body weight, plasma ghrelin, hypothalamic NPY, melanocortin 3 receptor (MC3R), ghrelin O-acyltransferase (GOAT), acyl ghrelin (AG) and ghrelin receptor (GHSR1a) were examined and compared. Food intake, body weight and NPY expression decreased, while MC3R expression increased and expressed reciprocally to NPY expression during AMPH treatment. Plasma ghrelin and hypothalamic AG/GOAT/GHSR1a expression decreased on Day 1 and Day 2, which was associated with the positive energy metabolism, and returned to normal levels on Day 3 and Day 4, which was associated with the negative energy metabolism; this expression pattern was similar to that of NPY. Infusion with a GHSR1a antagonist or an NPY antisense into the brain enhanced the decrease in NPY and AG/GOAT/GHSR1a expression and the increase in MC3R expression compared to the AMPH-treated group. Peripheral ghrelin and the central ghrelin system participated in the regulation in AMPH-induced appetite control. These results shed light on the involvement of ghrelin signalling in reciprocal regulation of NPY/POMC-mediated appetite control and may prove useful for the development of anti-obesity drugs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Apoptosis gene expression and death receptor signaling in mitomycin-C-treated human tenon capsule fibroblasts.

PubMed

Crowston, Jonathan G; Chang, Lydia H; Constable, Peter H; Daniels, Julie T; Akbar, Arne N; Khaw, Peng T

2002-03-01

To examine the effect of mitomycin-C on the expression of apoptosis genes in human Tenon capsule fibroblasts and to evaluate whether death receptor signaling modulates mitomycin-C cytotoxicity. Bcl-2, Bax, Bcl-x, Fas (CD95) and tumor necrosis factor (TNF) receptor expression was determined by flow cytometry in control and mitomycin-C-treated Tenon fibroblasts. Fibroblast death was quantified using a lactate dehydrogenase release assay. The effect of Fas and TNF-receptor signaling was evaluated using Fas-specific antibodies and soluble TNF-alpha. Tenon fibroblasts constitutively express Bcl-2, Bax, and Bcl-x in culture. Mitomycin-C (0.4 mg/mL) induced a small but consistent increase in the expression of all three proteins. Tenon fibroblasts express low levels of Fas but are resistant to the effects of Fas-receptor ligation. Mitomycin-C (0.01-1.0 mg/mL) led to a significant increase in Fas expression at all concentrations tested (P < 0.01). Pretreatment with mitomycin-C (0.4 mg/mL) rendered fibroblasts susceptible to agonistic anti-Fas monoclonal IgM antibodies (50-500 ng/mL) and led to a further 50% reduction in viable fibroblasts at 48 hours, compared with mitomycin-C alone (P < 0.05). Antibodies that block the Fas receptor did not inhibit mitomycin-C-induced apoptosis. Mitomycin-C alters apoptosis gene expression and primes fibroblasts to the effects of Fas receptor ligation. Factors other than the level of Fas receptor expression modulate the response to Fas receptor signaling. Determining the signals that regulate fibroblast apoptosis may help to refine therapeutic strategies for switching off the subconjunctival healing response and maintaining intraocular pressure control.

A Bmp/Admp regulatory circuit controls maintenance and regeneration of dorsal-ventral polarity in planarians

PubMed Central

Gaviño, Michael A.; Reddien, Peter W.

2011-01-01

Animal embryos have diverse anatomy and vary greatly in size. It is therefore remarkable that a common signaling pathway – BMP signaling – controls development of the dorsoventral (DV) axis throughout the Bilateria [1-8]. In vertebrates, spatially opposed expression of the BMP-family signaling proteins Bmp4 and Admp (anti-dorsalizing morphogenetic protein) can promote restoration of DV pattern following tissue removal [9-11]. bmp4 orthologs have been identified in all three groups of the Bilateria (deuterostomes, ecdysozoans, and lophotrochozoans) [12]. By contrast, the absence of admp orthologs in ecdysozoans such as Drosophila and C. elegans has suggested that a DV regulatory circuit of oppositely expressed bmp4 and admp genes represents an innovation specific to deuterostomes. Here we describe the existence of spatially opposed bmp and admp expression in a protostome. An admp ortholog (Smed-admp) is expressed at the ventral pole and laterally in adult Schmidtea mediterranea planarians, spatially opposing the dorsal-pole domain of Smed-bmp4 expression. Smed-admp is required for planarian regeneration following parasagittal amputation. Furthermore, Smed-admp promotes Smed-bmp4 expression and Smed-bmp4 inhibits Smed-admp expression, generating a regulatory circuit that buffers against perturbations of Bmp signaling. These results suggest that a Bmp/Admp regulatory circuit is a central feature of the Bilateria, used broadly for the establishment, maintenance, and regeneration of the DV axis. PMID:21295483

Control of somite patterning by Sonic hedgehog and its downstream signal response genes.

PubMed

Borycki, A G; Mendham, L; Emerson, C P

1998-02-01

In the avian embryo, previous work has demonstrated that the notochord provides inductive signals to activate myoD and pax1 regulatory genes, which are expressed in the dorsal and ventral somite cells that give rise to myotomal and sclerotomal lineages. Here, we present bead implantation and antisense inhibition experiments that show that Sonic hedgehog is both a sufficient and essential notochord signal molecule for myoD and pax1 activation in somites. Furthermore, we show that genes of the Sonic hedgehog signal response pathway, specifically patched, the Sonic hedgehog receptor, and gli and gli2/4, zinc-finger transcription factors, are activated in coordination with somite formation, establishing that Sonic hedgehog response genes play a regulatory role in coordinating the response of somites to the constitutive notochord Sonic hedgehog signal. Furthermore, the expression of patched, gli and gli2/4 is differentially patterned in the somite, providing mechanisms for differentially transducing the Sonic hedgehog signal to the myotomal and sclerotomal lineages. Finally, we show that the activation of gli2/4 is controlled by the process of somite formation and signals from the surface ectoderm, whereas upregulation of patched and activation of gli is controlled by the process of somite formation and a Sonic hedgehog signal. The Sonic hedgehog signal response genes, therefore, have important functions in regulating the initiation of the Sonic hedgehog response in newly forming somites and in regulating the patterned expression of myoD and pax1 in the myotomal and sclerotomal lineages following somite formation.

Glycolysis Controls Plasma Membrane Glucose Sensors To Promote Glucose Signaling in Yeasts

PubMed Central

Cairey-Remonnay, Amélie; Deffaud, Julien; Wésolowski-Louvel, Micheline; Lemaire, Marc

2014-01-01

Sensing of extracellular glucose is necessary for cells to adapt to glucose variation in their environment. In the respiratory yeast Kluyveromyces lactis, extracellular glucose controls the expression of major glucose permease gene RAG1 through a cascade similar to the Saccharomyces cerevisiae Snf3/Rgt2/Rgt1 glucose signaling pathway. This regulation depends also on intracellular glucose metabolism since we previously showed that glucose induction of the RAG1 gene is abolished in glycolytic mutants. Here we show that glycolysis regulates RAG1 expression through the K. lactis Rgt1 (KlRgt1) glucose signaling pathway by targeting the localization and probably the stability of Rag4, the single Snf3/Rgt2-type glucose sensor of K. lactis. Additionally, the control exerted by glycolysis on glucose signaling seems to be conserved in S. cerevisiae. This retrocontrol might prevent yeasts from unnecessary glucose transport and intracellular glucose accumulation. PMID:25512610

Gibberellins modulate auxin responses during tomato (Solanum lycopersicum L.) fruit development.

PubMed

Mignolli, Francesco; Vidoz, Maria L; Picciarelli, Piero; Mariotti, Lorenzo

2018-06-10

In tomato, auxin and gibberellins (GAs) interact with each other to drive fruit growth and development. While the role of auxin in directing GA biosynthesis and signal is already known, very little information has been obtained about GA-mediated control of auxin signalling and response. Interestingly, we show that GA 3 is able to modify the expression of several auxin signalling genes in the partial auxin-insensitive diageotropica (dgt) mutant, suggesting that GAs may override the control of DGT on auxin signal. Procera (pro) mutation, which confers a constitutively active GA signal, enhances the effects of exogenous auxin, indicating that PRO may act as a negative effector of auxin responses in fruits. Indeed, transcript modulation of some Aux/IAA and ARF genes in auxin-treated dgt/pro fruits, suggests that PRO controls their expression possibly bypassing DGT. It was also shown that GA biosynthesis, in response to auxin treatment, is largely controlled by DGT. It is therefore conceivable that the DGT-mediated increase of active GAs in auxin-treated or pollinated fruits, would promote PRO degradation, which in turn activates part of the auxin signalling cascade. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Wnt/β-catenin signaling cascade down-regulation following massive small bowel resection in a rat.

PubMed

Sukhotnik, Igor; Roitburt, Alex; Pollak, Yulia; Dorfman, Tatiana; Matter, Ibrahim; Mogilner, Jorge G; Bejar, Jacob; Coran, Arnold G

2014-02-01

Growing evidence suggests that the Wnt/β-catenin signaling cascade is implicated in the control of stem cell activity, cell proliferation, lineage commitment, and cell survival during normal development and tissue regeneration of the gastrointestinal epithelium. The roles of this signaling cascade in stimulation of cell proliferation after massive small bowel resection are unknown. The purpose of this study was to evaluate the role of Wnt/β-catenin signaling during late stages of intestinal adaptation in a rat model of short bowel syndrome (SBS). Male rats were divided into two groups: sham rats underwent bowel transection and SBS rats underwent a 75 % bowel resection. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined 2 weeks after operation. Illumina's digital gene expression analysis was used to determine Wnt/β-catenin signaling gene expression profiling. Twelve Wnt/β-catenin-related genes and β-catenin protein expression were determined using real-time PCR, western blotting and immunohistochemistry. From the total number of 20,000 probes, 20 genes related to Wnt/β-catenin signaling were investigated. From these genes, seven genes were found to be up-regulated and eight genes to be down-regulated in SBS vs. sham animals with a relative change in gene expression level of 20 % or more. From 12 genes determined by real-time PCR, nine genes were down-regulated in SBS rats compared to control animals including target gene c-Myc. SBS rats also showed a significant decrease in β-catenin protein compared to control animals. Two weeks following massive bowel resection in rats, Wnt/β-catenin signaling pathway is inhibited. In addition, it appears that cell differentiation rather than proliferation is most important in the late stages of intestinal adaptation.

A method for studying the hunting oscillations of an airplane with a simple type of automatic control

NASA Technical Reports Server (NTRS)

Jones, R. T.

1976-01-01

A method is presented for predicting the amplitude and frequency, under certain simplifying conditions, of the hunting oscillations of an automatically controlled aircraft with lag in the control system or in the response of the aircraft to the controls. If the steering device is actuated by a simple right-left type of signal, the series of alternating fixed amplitude signals occuring during the hunting may ordinarily be represented by a square wave. Formulas are given expressing the response to such a variation of signal in terms of the response to a unit signal.

Stability analysis of dynamic collaboration model with control signals on two lanes

NASA Astrophysics Data System (ADS)

Li, Zhipeng; Zhang, Run; Xu, Shangzhi; Qian, Yeqing; Xu, Juan

2014-12-01

In this paper, the influence of control signals on the stability of two-lane traffic flow is mainly studied by applying control theory with lane changing behaviors. We present the two-lane dynamic collaboration model with lateral friction and the expressions of feedback control signals. What is more, utilizing the delayed feedback control theory to the two-lane dynamic collaboration model with control signals, we investigate the stability of traffic flow theoretically and the stability conditions for both lanes are derived with finding that the forward and lateral feedback signals can improve the stability of traffic flow while the backward feedback signals cannot achieve it. Besides, direct simulations are conducted to verify the results of theoretical analysis, which shows that the feedback signals have a significant effect on the running state of two vehicle groups, and the results are same with the theoretical analysis.

Nitric Oxide Mediates the Hormonal Control of Crassulacean Acid Metabolism Expression in Young Pineapple Plants1[W][OA

PubMed Central

Freschi, Luciano; Rodrigues, Maria Aurineide; Domingues, Douglas Silva; Purgatto, Eduardo; Van Sluys, Marie-Anne; Magalhaes, Jose Ronaldo; Kaiser, Werner M.; Mercier, Helenice

2010-01-01

Genotypic, developmental, and environmental factors converge to determine the degree of Crassulacean acid metabolism (CAM) expression. To characterize the signaling events controlling CAM expression in young pineapple (Ananas comosus) plants, this photosynthetic pathway was modulated through manipulations in water availability. Rapid, intense, and completely reversible up-regulation in CAM expression was triggered by water deficit, as indicated by the rise in nocturnal malate accumulation and in the expression and activity of important CAM enzymes. During both up- and down-regulation of CAM, the degree of CAM expression was positively and negatively correlated with the endogenous levels of abscisic acid (ABA) and cytokinins, respectively. When exogenously applied, ABA stimulated and cytokinins repressed the expression of CAM. However, inhibition of water deficit-induced ABA accumulation did not block the up-regulation of CAM, suggesting that a parallel, non-ABA-dependent signaling route was also operating. Moreover, strong evidence revealed that nitric oxide (NO) may fulfill an important role during CAM signaling. Up-regulation of CAM was clearly observed in NO-treated plants, and a conspicuous temporal and spatial correlation was also evident between NO production and CAM expression. Removal of NO from the tissues either by adding NO scavenger or by inhibiting NO production significantly impaired ABA-induced up-regulation of CAM, indicating that NO likely acts as a key downstream component in the ABA-dependent signaling pathway. Finally, tungstate or glutamine inhibition of the NO-generating enzyme nitrate reductase completely blocked NO production during ABA-induced up-regulation of CAM, characterizing this enzyme as responsible for NO synthesis during CAM signaling in pineapple plants. PMID:20147491

Alx4 relays sequential FGF signaling to induce lacrimal gland morphogenesis

PubMed Central

Garg, Ankur; Gotoh, Noriko; Feng, Gen-Sheng; Zhong, Jian; Wang, Fen; Kariminejad, Ariana; Brooks, Steven

2017-01-01

The sequential use of signaling pathways is essential for the guidance of pluripotent progenitors into diverse cell fates. Here, we show that Shp2 exclusively mediates FGF but not PDGF signaling in the neural crest to control lacrimal gland development. In addition to preventing p53-independent apoptosis and promoting the migration of Sox10-expressing neural crests, Shp2 is also required for expression of the homeodomain transcription factor Alx4, which directly controls Fgf10 expression in the periocular mesenchyme that is necessary for lacrimal gland induction. We show that Alx4 binds an Fgf10 intronic element conserved in terrestrial but not aquatic animals, underlying the evolutionary emergence of the lacrimal gland system in response to an airy environment. Inactivation of ALX4/Alx4 causes lacrimal gland aplasia in both human and mouse. These results reveal a key role of Alx4 in mediating FGF-Shp2-FGF signaling in the neural crest for lacrimal gland development. PMID:29028795

Alx4 relays sequential FGF signaling to induce lacrimal gland morphogenesis.

PubMed

Garg, Ankur; Bansal, Mukesh; Gotoh, Noriko; Feng, Gen-Sheng; Zhong, Jian; Wang, Fen; Kariminejad, Ariana; Brooks, Steven; Zhang, Xin

2017-10-01

The sequential use of signaling pathways is essential for the guidance of pluripotent progenitors into diverse cell fates. Here, we show that Shp2 exclusively mediates FGF but not PDGF signaling in the neural crest to control lacrimal gland development. In addition to preventing p53-independent apoptosis and promoting the migration of Sox10-expressing neural crests, Shp2 is also required for expression of the homeodomain transcription factor Alx4, which directly controls Fgf10 expression in the periocular mesenchyme that is necessary for lacrimal gland induction. We show that Alx4 binds an Fgf10 intronic element conserved in terrestrial but not aquatic animals, underlying the evolutionary emergence of the lacrimal gland system in response to an airy environment. Inactivation of ALX4/Alx4 causes lacrimal gland aplasia in both human and mouse. These results reveal a key role of Alx4 in mediating FGF-Shp2-FGF signaling in the neural crest for lacrimal gland development.

YAP regulates neuronal differentiation through Sonic hedgehog signaling pathway

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

Lin, Yi-Ting; Ding, Jing-Ya; Li, Ming-Yang

2012-09-10

Tight regulation of cell numbers by controlling cell proliferation and apoptosis is important during development. Recently, the Hippo pathway has been shown to regulate tissue growth and organ size in Drosophila. In mammalian cells, it also affects cell proliferation and differentiation in various tissues, including the nervous system. Interplay of several signaling cascades, such as Notch, Wnt, and Sonic Hedgehog (Shh) pathways, control cell proliferation during neuronal differentiation. However, it remains unclear whether the Hippo pathway coordinates with other signaling cascades in regulating neuronal differentiation. Here, we used P19 cells, a mouse embryonic carcinoma cell line, as a model tomore » study roles of YAP, a core component of the Hippo pathway, in neuronal differentiation. P19 cells can be induced to differentiate into neurons by expressing a neural bHLH transcription factor gene Ascl1. Our results showed that YAP promoted cell proliferation and inhibited neuronal differentiation. Expression of Yap activated Shh but not Wnt or Notch signaling activity during neuronal differentiation. Furthermore, expression of Yap increased the expression of Patched homolog 1 (Ptch1), a downstream target of the Shh signaling. Knockdown of Gli2, a transcription factor of the Shh pathway, promoted neuronal differentiation even when Yap was over-expressed. We further demonstrated that over-expression of Yap inhibited neuronal differentiation in primary mouse cortical progenitors and Gli2 knockdown rescued the differentiation defect in Yap over-expressing cells. In conclusion, our study reveals that Shh signaling acts downstream of YAP in regulating neuronal differentiation. -- Highlights: Black-Right-Pointing-Pointer YAP promotes cell proliferation and inhibits neuronal differentiation in P19 cells. Black-Right-Pointing-Pointer YAP promotes Sonic hedgehog signaling activity during neuronal differentiation. Black-Right-Pointing-Pointer Knockdown of Gli2 rescues the Yap-overexpression phenotype in P19 cells. Black-Right-Pointing-Pointer Knockdown of Gli2 rescues the Yap-overexpression phenotype in cortical progenitors.« less

EMMPRIN regulates tumor growth and metastasis by recruiting bone marrow-derived cells through paracrine signaling of SDF-1 and VEGF.

PubMed

Chen, Yanke; Gou, Xingchun; Kong, Derek Kai; Wang, Xiaofei; Wang, Jianhui; Chen, Zeming; Huang, Chen; Zhou, Jiangbing

2015-10-20

EMMPRIN, a cell adhesion molecule highly expressed in a variety of tumors, is associated with poor prognosis in cancer patients. Mechanistically, EMMPRIN has been characterized to contribute to tumor development and progression by controlling the expression of MMPs and VEGF. In the present study, by using fluorescently labeled bone marrow-derived cells (BMDCs), we found that the down-regulation of EMMPRIN expression in cancer cells reduces tumor growth and metastasis, and is associated with the reduced recruitment of BMDCs. Further protein profiling studies suggest that EMMPRIN controls BMDC recruitment through regulating the secretion of soluble factors, notably, VEGF and SDF-1. We demonstrate that the expression and secretion of SDF-1 in tumor cells are regulated by EMMPRIN. This study reveals a novel mechanism by which EMMPRIN promotes tumor growth and metastasis by recruitment of BMDCs through controlling secretion and paracrine signaling of SDF-1 and VEGF.

Computational design of a Zn2+ receptor that controls bacterial gene expression

NASA Astrophysics Data System (ADS)

Dwyer, M. A.; Looger, L. L.; Hellinga, H. W.

2003-09-01

The control of cellular physiology and gene expression in response to extracellular signals is a basic property of living systems. We have constructed a synthetic bacterial signal transduction pathway in which gene expression is controlled by extracellular Zn2+. In this system a computationally designed Zn2+-binding periplasmic receptor senses the extracellular solute and triggers a two-component signal transduction pathway via a chimeric transmembrane protein, resulting in transcriptional up-regulation of a -galactosidase reporter gene. The Zn2+-binding site in the designed receptor is based on a four-coordinate, tetrahedral primary coordination sphere consisting of histidines and glutamates. In addition, mutations were introduced in a secondary coordination sphere to satisfy the residual hydrogen-bonding potential of the histidines coordinated to the metal. The importance of the secondary shell interactions is demonstrated by their effect on metal affinity and selectivity, as well as protein stability. Three designed protein sequences, comprising two distinct metal-binding positions, were all shown to bind Zn2+ and to function in the cell-based assay, indicating the generality of the design methodology. These experiments demonstrate that biological systems can be manipulated with computationally designed proteins that have drastically altered ligand-binding specificities, thereby extending the repertoire of genetic control by extracellular signals.

Expression profiles of miRNAs from bovine mammary glands in response to Streptococcus agalactiae-induced mastitis.

PubMed

Pu, Junhua; Li, Rui; Zhang, Chenglong; Chen, Dan; Liao, Xiangxiang; Zhu, Yihui; Geng, Xiaohan; Ji, Dejun; Mao, Yongjiang; Gong, Yunchen; Yang, Zhangping

2017-08-01

This study aimed to describe the expression profiles of microRNAs (miRNAs) from mammary gland tissues collected from dairy cows with Streptococcus agalactiae-induced mastitis and to identify differentially expressed miRNAs related to mastitis. The mammary glands of Chinese Holstein cows were challenged with Streptococcus agalactiae to induce mastitis. Small RNAs were isolated from the mammary tissues of the test and control groups and then sequenced using the Solexa sequencing technology to construct two small RNA libraries. Potential target genes of these differentially expressed miRNAs were predicted using the RNAhybrid software, and KEGG pathways associated with these genes were analysed. A total of 18 555 913 and 20 847 000 effective reads were obtained from the test and control groups, respectively. In total, 373 known and 399 novel miRNAs were detected in the test group, and 358 known and 232 novel miRNAs were uncovered in the control group. A total of 35 differentially expressed miRNAs were identified in the test group compared to the control group, including 10 up-regulated miRNAs and 25 down-regulated miRNAs. Of these miRNAs, miR-223 exhibited the highest degree of up-regulation with an approximately 3-fold increase in expression, whereas miR-26a exhibited the most decreased expression level (more than 2-fold). The RNAhybrid software predicted 18 801 genes as potential targets of these 35 miRNAs. Furthermore, several immune response and signal transduction pathways, including the RIG-I-like receptor signalling pathway, cytosolic DNA sensing pathway and Notch signal pathway, were enriched in these predicted targets. In summary, this study provided experimental evidence for the mechanism underlying the regulation of bovine mastitis by miRNAs and showed that miRNAs might be involved in signal pathways during S. agalactiae-induced mastitis.

Reduced expression of G protein-coupled receptor kinases in schizophrenia but not in schizoaffective disorder

PubMed Central

Bychkov, ER; Ahmed, MR; Gurevich, VV; Benovic, JL; Gurevich, EV

2011-01-01

Alterations of multiple G protein-mediated signaling pathways are detected in schizophrenia. G protein-coupled receptor kinases (GRKs) and arrestins terminate signaling by G protein-coupled receptors exerting powerful influence on receptor functions. Modifications of arrestin and/or GRKs expression may contribute to schizophrenia pathology. Cortical expression of arrestins and GRKs was measured postmortem in control and subjects with schizophrenia or schizoaffective disorder. Additionally, arrestin/GRK expression was determined in elderly patients with schizophrenia and age-matched control. Patients with schizophrenia, but not schizoaffective disorder, displayed reduced concentration of arrestin and GRK mRNAs and GRK3 protein. Arrestins and GRK significantly decreased with age. In elderly patients, GRK6 was reduced, with other GRKs and arrestins unchanged. Reduced cortical concentration of GRKs in schizophrenia (resembling that in aging) may result in altered G protein-dependent signaling, thus contributing to prefrontal deficits in schizophrenia. The data suggest distinct molecular mechanisms underlying schizophrenia and schizoaffective disorder. PMID:21784156

The interaction and integration of auxin signaling components.

PubMed

Hayashi, Ken-ichiro

2012-06-01

IAA, a naturally occurring auxin, is a simple signaling molecule that regulates many diverse steps of plant development. Auxin essentially coordinates plant development through transcriptional regulation. Auxin binds to TIR1/AFB nuclear receptors, which are F-box subunits of the SCF ubiquitin ligase complex. The auxin signal is then modulated by the quantitative and qualitative responses of the Aux/IAA repressors and the auxin response factor (ARF) transcription factors. The specificity of the auxin-regulated gene expression profile is defined by several factors, such as the expression of these regulatory proteins, their post-transcriptional regulation, their stability and the affinity between these regulatory proteins. Auxin-binding protein 1 (ABP1) is a candidate protein for an auxin receptor that is implicated in non-transcriptional auxin signaling. ABP1 also affects TIR1/AFB-mediated auxin-responsive gene expression, implying that both the ABP1 and TIR1/AFB signaling machineries coordinately control auxin-mediated physiological events. Systematic approaches using the comprehensive mapping of the expression and interaction of signaling modules and computational modeling would be valuable for integrating our knowledge of auxin signals and responses.

Differential Expression of microRNAs in the Ovaries from Letrozole-Induced Rat Model of Polycystic Ovary Syndrome.

PubMed

Li, Dandan; Li, Chunjin; Xu, Ying; Xu, Duo; Li, Hongjiao; Gao, Liwei; Chen, Shuxiong; Fu, Lulu; Xu, Xin; Liu, Yongzheng; Zhang, Xueying; Zhang, Jingshun; Ming, Hao; Zheng, Lianwen

2016-04-01

Polycystic ovary syndrome (PCOS) is a complex and heterogeneous endocrine disorder. To understand the pathogenesis of PCOS, we established rat models of PCOS induced by letrozole and employed deep sequencing to screen the differential expression of microRNAs (miRNAs) in PCOS rats and control rats. We observed vaginal smear and detected ovarian pathological alteration and hormone level changes in PCOS rats. Deep sequencing showed that a total of 129 miRNAs were differentially expressed in the ovaries from letrozole-induced rat model compared with the control, including 49 miRNAs upregulated and 80 miRNAs downregulated. Furthermore, the differential expression of miR-201-5p, miR-34b-5p, miR-141-3p, and miR-200a-3p were confirmed by real-time polymerase chain reaction. Bioinformatic analysis revealed that these four miRNAs were predicted to target a large set of genes with different functions. Pathway analysis supported that the miRNAs regulate oocyte meiosis, mitogen-activated protein kinase (MAPK) signaling, phosphoinositide 3-kinase/Akt (PI3K-Akt) signaling, Rap1 signaling, and Notch signaling. These data indicate that miRNAs are differentially expressed in rat PCOS model and the differentially expressed miRNA are involved in the etiology and pathophysiology of PCOS. Our findings will help identify miRNAs as novel diagnostic markers and therapeutic targets for PCOS.

Bit-1 is an essential regulator of myogenic differentiation

PubMed Central

Griffiths, Genevieve S.; Doe, Jinger; Jijiwa, Mayumi; Van Ry, Pam; Cruz, Vivian; de la Vega, Michelle; Ramos, Joe W.; Burkin, Dean J.; Matter, Michelle L.

2015-01-01

Muscle differentiation requires a complex signaling cascade that leads to the production of multinucleated myofibers. Genes regulating the intrinsic mitochondrial apoptotic pathway also function in controlling cell differentiation. How such signaling pathways are regulated during differentiation is not fully understood. Bit-1 (also known as PTRH2) mutations in humans cause infantile-onset multisystem disease with muscle weakness. We demonstrate here that Bit-1 controls skeletal myogenesis through a caspase-mediated signaling pathway. Bit-1-null mice exhibit a myopathy with hypotrophic myofibers. Bit-1-null myoblasts prematurely express muscle-specific proteins. Similarly, knockdown of Bit-1 expression in C2C12 myoblasts promotes early differentiation, whereas overexpression delays differentiation. In wild-type mice, Bit-1 levels increase during differentiation. Bit-1-null myoblasts exhibited increased levels of caspase 9 and caspase 3 without increased apoptosis. Bit-1 re-expression partially rescued differentiation. In Bit-1-null muscle, Bcl-2 levels are reduced, suggesting that Bcl-2-mediated inhibition of caspase 9 and caspase 3 is decreased. Bcl-2 re-expression rescued Bit-1-mediated early differentiation in Bit-1-null myoblasts and C2C12 cells with knockdown of Bit-1 expression. These results support an unanticipated yet essential role for Bit-1 in controlling myogenesis through regulation of Bcl-2. PMID:25770104

Tbx6-mediated Notch signaling controls somite-specific Mesp2 expression.

PubMed

Yasuhiko, Yukuto; Haraguchi, Seiki; Kitajima, Satoshi; Takahashi, Yu; Kanno, Jun; Saga, Yumiko

2006-03-07

Mesp2 is a transcription factor that plays fundamental roles in somitogenesis, and its expression is strictly restricted to the anterior presomitic mesoderm just before segment border formation. The transcriptional on-off cycle is linked to the segmentation clock. In our current study, we show that a T-box transcription factor, Tbx6, is essential for Mesp2 expression. Tbx6 directly binds to the Mesp2 gene upstream region and mediates Notch signaling, and subsequent Mesp2 transcription, in the anterior presomitic mesoderm. Our data therefore reveal that a mechanism, via Tbx6-dependent Notch signaling, acts on the transcriptional regulation of Mesp2. This finding uncovers an additional component of the interacting network of various signaling pathways that are involved in somitogenesis.

Control of germline stem cell self-renewal and differentiation in the Drosophila ovary: concerted actions of niche signals and intrinsic factors.

PubMed

Xie, Ting

2013-01-01

In the Drosophila ovary, germline stem cells (GSCs) physically interact with their niche composed of terminal filament cells, cap cells, and possibly GSC-contacting escort cells (ECs). A GSC divides to generate a self-renewing stem cell that remains in the niche and a differentiating daughter that moves away from the niche. The GSC niche provides a bone morphogenetic protein (BMP) signal that maintains GSC self-renewal by preventing stem cell differentiation via repression of the differentiation-promoting gene bag of marbles (bam). In addition, it expresses E-cadherin, which mediates cell adhesion for anchoring GSCs in the niche, enabling continuous self-renewal. GSCs themselves also express different classes of intrinsic factors, including signal transducers, transcription factors, chromatin remodeling factors, translation regulators, and miRNAs, which control self-renewal by strengthening interactions with the niche and repressing various differentiation pathways. Differentiated GSC daughters, known as cystoblasts (CBs), also express distinct classes of intrinsic factors to inhibit self-renewal and promote germ cell differentiation. Surprisingly, GSC progeny are also dependent on their surrounding ECs for proper differentiation at least partly by preventing BMP from diffusing to the differentiated germ cell zone and by repressing ectopic BMP expression. Therefore, both GSC self-renewal and CB differentiation are controlled by collaborative actions of extrinsic signals and intrinsic factors. Copyright © 2012 Wiley Periodicals, Inc.

Nutrient sensing and insulin signaling in neuropeptide-expressing immortalized, hypothalamic neurons: A cellular model of insulin resistance.

PubMed

Fick, Laura J; Belsham, Denise D

2010-08-15

Obesity and type 2 diabetes mellitus represent a significant global health crisis. These two interrelated diseases are typified by perturbed insulin signaling in the hypothalamus. Using novel hypothalamic cell lines, we have begun to elucidate the molecular and intracellular mechanisms involved in the hypothalamic control of energy homeostasis and insulin resistance. In this review, we present evidence of insulin and glucose signaling pathways that lead to changes in neuropeptide gene expression. We have identified some of the molecular mechanisms involved in the control of de novo hypothalamic insulin mRNA expression. And finally, we have defined key mechanisms involved in the etiology of cellular insulin resistance in hypothalamic neurons that may play a fundamental role in cases of high levels of insulin or saturated fatty acids, often linked to the exacerbation of obesity and diabetes.

Notch signaling genes

PubMed Central

Terragni, Jolyon; Zhang, Guoqiang; Sun, Zhiyi; Pradhan, Sriharsa; Song, Lingyun; Crawford, Gregory E; Lacey, Michelle; Ehrlich, Melanie

2014-01-01

Notch intercellular signaling is critical for diverse developmental pathways and for homeostasis in various types of stem cells and progenitor cells. Because Notch gene products need to be precisely regulated spatially and temporally, epigenetics is likely to help control expression of Notch signaling genes. Reduced representation bisulfite sequencing (RRBS) indicated significant hypomethylation in myoblasts, myotubes, and skeletal muscle vs. many nonmuscle samples at intragenic or intergenic regions of the following Notch receptor or ligand genes: NOTCH1, NOTCH2, JAG2, and DLL1. An enzymatic assay of sites in or near these genes revealed unusually high enrichment of 5-hydroxymethylcytosine (up to 81%) in skeletal muscle, heart, and cerebellum. Epigenetics studies and gene expression profiles suggest that hypomethylation and/or hydroxymethylation help control expression of these genes in heart, brain, myoblasts, myotubes, and within skeletal muscle myofibers. Such regulation could promote cell renewal, cell maintenance, homeostasis, and a poised state for repair of tissue damage. PMID:24670287

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

Dai, Ziyu; Hooker, Brian S.; Anderson, Daniel B.

Optimization of Acidothermus cellulolyticus endoglucanase (E1) gene expression in transgenic potato (Solanum tuberosum L.) was examined in this study, where the E1 coding sequence was transcribed under control of a leaf specific promoter (tomato RbcS-3C) or the Mac promoter (a hybrid promoter of mannopine synthase promoter and cauliflower mosaic virus 35S promoter enhancer region). Average E1 activity in leaf extracts of potato transformants, in which E1 protein was targeted by a chloroplast signal peptide and an apoplast signal peptide were much higher than those by an E1 native signal peptide and a vacuole signal peptide. E1 protein accumulated up tomore » 2.6% of total leaf soluble protein, where E1 gene was under control of the RbcS-3C promoter, alfalfa mosaic virus 5-untranslated leader, and RbcS-2A signal peptide. E1 protein production, based on average E1 activity and E1 protein accumulation in leaf extracts, is higher in potato than those measured previously in transgenic tobacco bearing the same transgene constructs. Comparisons of E1 activity, protein accumulation, and relative mRNA levels showed that E1 expression under control of tomato RbcS-3C promoter was specifically localized in leaf tissues, while E1 gene was expressed in both leaf and tuber tissues under control of Mac promoter. This suggests dual-crop applications in which potato vines serve as enzyme production `bioreactors' while tubers are preserved for culinary applications.« less

Up-regulated expression of WNT5a increases inflammation and oxidative stress via PI3K/AKT/NF-κB signaling in the granulosa cells of PCOS patients.

PubMed

Zhao, Yue; Zhang, Chunmei; Huang, Ying; Yu, Yang; Li, Rong; Li, Min; Liu, Nana; Liu, Ping; Qiao, Jie

2015-01-01

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disorder accompanied by chronic low-grade inflammation, but the molecular mechanism remains unclear. We investigated the action of WNT5a in the development of chronic inflammation in PCOS and the related molecular signaling pathways. This was a prospective study conducted at the Division of Reproduction Center, Peking University Third Hospital. A total of 35 PCOS patients and 87 control women who reported to the clinic for the in vitro procedure and the cause of marital infertility was male azoospermia were included. Mural granulosa cells (GCs) of 35 PCOS patients and 37 controls were collected during oocyte retrieval and gene expression was analyzed. The human KGN cells and mural GCs from 50 control subjects (six to eight samples were pooled together for each experiment) were cultured in vitro. The regulation of inflammation and oxidative stress was confirmed by quantitative PCR, flow-cytometric assay, and dual-luciferase reporter assay after inflammatory stimuli or WNT5a overexpression. Relevant signaling pathways were identified using specific inhibitors. Our data demonstrate significantly elevated WNT5a expression in the mural GCs of PCOS patients compared with the controls. Lipopolysaccharide stimulation increased WNT5a expression in KGN cells and mural GCs, and BAY-117082 and pyrrolidinedithiocarbamic acid [nuclear factor-κB (NF-κB) inhibitor] treatments suppressed WNT5a mRNA below the control level. WNT5a overexpression also enhanced the expression of inflammation-related genes and increased intracellular reactive oxygen species, whereas both BAY-117082 and LY-294002 (phosphatidylinositol 3-kinase inhibitor) significantly inhibited WNT5a-induced inflammation and oxidative stress. WNT5a acts as a proinflammatory factor in human ovarian GCs. The up-regulated expression of WNT5a in PCOS increases inflammation and oxidative stress predominantly via the phosphatidylinositol 3-kinase/AKT/NF-κB signaling pathway. The proinflammatory cytokines induced might further enhance WNT5a expression via NF-κB-dependent regulation, indicating a novel regulatory system for chronic inflammation in PCOS.

Hedgehog Signaling Regulates the Survival of Gastric Cancer Cells by Regulating the Expression of Bcl-2

PubMed Central

Han, Myoung-Eun; Lee, Young-Suk; Baek, Sun-Yong; Kim, Bong-Seon; Kim, Jae-Bong; Oh, Sae-Ock

2009-01-01

Gastric cancer is the second most common cause of cancer deaths worldwide. The underlying molecular mechanisms of its carcinogenesis are relatively poorly characterized. Hedgehog (Hh) signaling, which is critical for development of various organs including the gastrointestinal tract, has been associated with gastric cancer. The present study was undertaken to reveal the underlying mechanism by which Hh signaling controls gastric cancer cell proliferation. Treatment of gastric cancer cells with cyclopamine, a specific inhibitor of Hh signaling pathway, reduced proliferation and induced apoptosis of gastric cancer cells. Cyclopamine treatment induced cytochrome c release from mitochondria and cleavage of caspase 9. Moreover, Bcl-2 expression was significantly reduced by cyclopamine treatment. These results suggest that Hh signaling regulates the survival of gastric cancer cells by regulating the expression of Bcl-2. PMID:19742123

Tissue Inhibitor of Metalloproteinase-2 (TIMP-2) expression is regulated by multiple neural differentiation signals

PubMed Central

Jaworski, Diane M.; Pérez-Martínez, Leonor

2010-01-01

Neuronal differentiation requires exquisitely timed cell cycle arrest for progenitors to acquire an appropriate neuronal cell fate and is achieved by communication between soluble signals, such as growth factors and extracellular matrix molecules. Here we report that the expression of TIMP-2, a matrix metalloproteinase inhibitor, is up-regulated by signals that control proliferation (bFGF and EGF) and differentiation (retinoic acid and NGF) in neural progenitor and neuroblastoma cell lines. TIMP-2 expression coincides with the appearance of neurofilament-positive neurons, indicating that TIMP-2 may play a role in neurogenesis. The up-regulation of TIMP-2 expression by proliferative signals suggests a role in the transition from proliferation to neuronal differentiation. Live labeling experiments demonstrate TIMP-2 expression only on α3 integrin-positive cells. Thus, TIMP-2 function may be mediated via interaction with integrin receptor(s). We propose that TIMP-2 represents a component of the neurogenic signaling cascade induced by mitogenic stimuli that may withdraw progenitor cells from the cell cycle permitting their terminal neuronal differentiation. PMID:16805810

NADPH oxidase 4 induces cardiac fibrosis and hypertrophy through activating Akt/mTOR and NFκB signaling pathways.

PubMed

Zhao, Qingwei David; Viswanadhapalli, Suryavathi; Williams, Paul; Shi, Qian; Tan, Chunyan; Yi, Xiaolan; Bhandari, Basant; Abboud, Hanna E

2015-02-17

NADPH oxidase 4 (Nox4) has been implicated in cardiac remodeling, but its precise role in cardiac injury remains controversial. Furthermore, little is known about the downstream effector signaling pathways activated by Nox4-derived reactive oxygen species in the myocardium. We investigated the role of Nox4 and Nox4-associated signaling pathways in the development of cardiac remodeling. Cardiac-specific human Nox4 transgenic mice (c-hNox4Tg) were generated. Four groups of mice were studied: (1) control mice, littermates that are negative for hNox4 transgene but Cre positive; (2) c-hNox4 Tg mice; (3) angiotensin II (AngII)-infused control mice; and (4) c-hNox4Tg mice infused with AngII. The c-hNox4Tg mice exhibited an ≈10-fold increase in Nox4 protein expression and an 8-fold increase in the production of reactive oxygen species, and manifested cardiac interstitial fibrosis. AngII infusion to control mice increased cardiac Nox4 expression and induced fibrosis and hypertrophy. The Tg mice receiving AngII exhibited more advanced cardiac remodeling and robust elevation in Nox4 expression, indicating that AngII worsens cardiac injury, at least in part by enhancing Nox4 expression. Moreover, hNox4 transgene and AngII infusion induced the expression of cardiac fetal genes and activated the Akt-mTOR and NFκB signaling pathways. Treatment of AngII-infused c-hNox4Tg mice with GKT137831, a Nox4/Nox1 inhibitor, abolished the increase in oxidative stress, suppressed the Akt-mTOR and NFκB signaling pathways, and attenuated cardiac remodeling. Upregulation of Nox4 in the myocardium causes cardiac remodeling through activating Akt-mTOR and NFκB signaling pathways. Inhibition of Nox4 has therapeutic potential to treat cardiac remodeling. © 2015 American Heart Association, Inc.

Hedgehog signaling plays roles in epithelial cell proliferation in neonatal mouse uterus and vagina.

PubMed

Nakajima, Tadaaki; Iguchi, Taisen; Sato, Tomomi

2012-04-01

Both the uterus and vagina develop from the Müllerian duct but are quite distinct in morphology and function. To investigate factors controlling epithelial differentiation and cell proliferation in neonatal uterus and vagina, we focused on Hedgehog (HH) signaling. In neonatal mice, Sonic hh (Shh) was localized in the vaginal epithelium and Indian hh (Ihh) was slightly expressed in the uterus and vagina, whereas all Glioma-associated oncogene homolog (Gli) genes were mainly expressed in the stroma. The expression of target genes of HH signaling was high in the neonatal vagina and in the uterus, it increased with growth. Thus, in neonatal mice, Shh in the vaginal epithelium and Ihh in the uterus and vagina activated HH signaling in the stroma. Tissue recombinants showed that vaginal Shh expression was inhibited by the vaginal stroma and uterine Ihh expression was stimulated by the uterine stroma. Addition of a HH signaling inhibitor decreased epithelial cell proliferation in organ-cultured uterus and vagina and increased stromal cell proliferation in organ-cultured uterus. However, it did not affect epithelial differentiation or the expression of growth factors in organ-cultured uterus and vagina. Thus, activated HH signaling stimulates epithelial cell proliferation in neonatal uterus and vagina but inhibits stromal cell proliferation in neonatal uterus.

Fibrin-Enhanced Canonical Wnt Signaling Directs Plasminogen Expression in Cementoblasts

PubMed Central

Rahman, Saeed Ur; Ryoo, Hyun-Mo

2017-01-01

Cementum is a mineralized layer on the tooth’s root surface and facilitates the biomechanical anchoring of fibrous connective tissues as a part of tooth-supportive complexes. Previously, we observed that OCCM30 cementoblasts cultured on fibrin matrices underwent apoptosis due to fibrin degradation through the expression of proteases. Here, we demonstrated that OCCM30 on fibrin matrices (OCCM30-fibrin) enhanced canonical Wnt signaling, which directed to plasminogen expression. The OCCM30-fibrin showed higher levels of Wnt3a expression, nuclear translocation of β-catenin, and T-cell factor (TCF) optimal motif (TOP) reporter activity than the cells on tissue culture dishes (OCCM30-TCD), indicating that the OCCM30-fibrin enhanced canonical Wnt/β-catenin signaling. Also, OCCM30-fibrin expressed biomineralization-associated markers at higher levels than OCCM30-TCD, of which levels were further increased with LiCl, a Wnt signaling activator. The OCCM30 cementoblasts simultaneously showed that high levels of plasminogen, a critical component of fibrinolysis, were expressed in the OCCM30-fibrin. Activation of canonical Wnt signaling with LiCl treatment or with forced lymphoid enhancer factor 1 (LEF1)-expression increased the expression of plasminogen. On the contrary, the inhibition of canonical Wnt signaling with siRNAs against Wnt3a or β-catenin abrogated fibrin-enhanced plasminogen expression. Furthermore, there are three conserved putative response elements for the LEF1/β-catenin complex in the plasminogen proximal promoter regions (−900 to +54). Site-directed mutations and chromatin immunoprecipitation indicated that canonical Wnt signaling directed plasminogen expression. Taken together, this study suggests that fibrin-based materials can modulate functional periodontal formations in controlling cementoblast differentiation and fibrin degradation. PMID:29120400

An integrated mechanism of cardiomyocyte nuclear Ca(2+) signaling.

PubMed

Ibarra, Cristián; Vicencio, Jose Miguel; Varas-Godoy, Manuel; Jaimovich, Enrique; Rothermel, Beverly A; Uhlén, Per; Hill, Joseph A; Lavandero, Sergio

2014-10-01

In cardiomyocytes, Ca(2+) plays a central role in governing both contraction and signaling events that regulate gene expression. Current evidence indicates that discrimination between these two critical functions is achieved by segregating Ca(2+) within subcellular microdomains: transcription is regulated by Ca(2+) release within nuclear microdomains, and excitation-contraction coupling is regulated by cytosolic Ca(2+). Accordingly, a variety of agonists that control cardiomyocyte gene expression, such as endothelin-1, angiotensin-II or insulin-like growth factor-1, share the feature of triggering nuclear Ca(2+) signals. However, signaling pathways coupling surface receptor activation to nuclear Ca(2+) release, and the phenotypic responses to such signals, differ between agonists. According to earlier hypotheses, the selective control of nuclear Ca(2+) signals by activation of plasma membrane receptors relies on the strategic localization of inositol trisphosphate receptors at the nuclear envelope. There, they mediate Ca(2+) release from perinuclear Ca(2+) stores upon binding of inositol trisphosphate generated in the cytosol, which diffuses into the nucleus. More recently, identification of such receptors at nuclear membranes or perinuclear sarcolemmal invaginations has uncovered novel mechanisms whereby agonists control nuclear Ca(2+) release. In this review, we discuss mechanisms for the selective control of nuclear Ca(2+) signals with special focus on emerging models of agonist receptor activation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Multiple Notch signaling events control Drosophila CNS midline neurogenesis, gliogenesis and neuronal identity

PubMed Central

Wheeler, Scott R.; Stagg, Stephanie B.; Crews, Stephen T.

2009-01-01

The study of how transcriptional control and cell signaling influence neurons and glia to acquire their differentiated properties is fundamental to understanding CNS development and function. The Drosophila CNS midline cells are an excellent system for studying these issues because they consist of a small population of diverse cells with well-defined gene expression profiles. In this paper, the origins and differentiation of midline neurons and glia were analyzed. Midline precursor (MP) cells each divide once giving rise to two neurons; here, we use a combination of single-cell gene expression mapping and time-lapse imaging to identify individual MPs, their locations, movements and stereotyped patterns of division. The role of Notch signaling was investigated by analyzing 37 midline-expressed genes in Notch pathway mutant and misexpression embryos. Notch signaling had opposing functions: it inhibited neurogenesis in MP1,3,4 and promoted neurogenesis in MP5,6. Notch signaling also promoted midline glial and median neuroblast cell fate. This latter result suggests that the median neuroblast resembles brain neuroblasts that require Notch signaling, rather than nerve cord neuroblasts, the formation of which is inhibited by Notch signaling. Asymmetric MP daughter cell fates also depend on Notch signaling. One member of each pair of MP3–6 daughter cells was responsive to Notch signaling. By contrast, the other daughter cell asymmetrically acquired Numb, which inhibited Notch signaling, leading to a different fate choice. In summary, this paper describes the formation and division of MPs and multiple roles for Notch signaling in midline cell development, providing a foundation for comprehensive molecular analyses. PMID:18701546

Dkk2/Frzb in the dermal papillae regulates feather regeneration

PubMed Central

Chu, Qiqi; Cai, Linyan; Fu, Yu; Chen, Xi; Yan, Zhipeng; Lin, Xiang; Zhou, Guixuan; Han, Hao; Widelitz, Randall B.; Chuong, Cheng-ming; Wu, Wei; Yue, Zhicao

2015-01-01

Avian feathers have robust growth and regeneration capability. To evaluate the contribution of signaling molecules and pathways in these processes, we profiled gene expression in the feather follicle using an absolute quantification approach. We identified hundreds of genes that mark specific components of the feather follicle: the dermal papillae (DP) which controls feather regeneration and axis formation, the pulp mesenchyme (Pp) which is derived from DP cells and nourishes the feather follicle, and the ramogenic zone epithelium (Erz) where a feather starts to branch. The feather DP is enriched in BMP/TGF-β signaling molecules and inhibitors for Wnt signaling including Dkk2/Frzb. Wnt ligands are mainly expressed in the feather epithelium and pulp. We find that while Wnt signaling is required for the maintenance of DP marker gene expression and feather regeneration, excessive Wnt signaling delays regeneration and reduces pulp formation. Manipulating Dkk2/Frzb expression by lentiviral-mediated overexpression, shRNA-knockdown, or by antibody neutralization resulted in dual feather axes formation. Our results suggest that the Wnt signaling in the proximal feather follicle is fine-tuned to accommodate feather regeneration and axis formation. PMID:24463139

Systems approach identifies an organic nitrogen-responsive gene network that is regulated by the master clock control gene CCA1.

PubMed

Gutiérrez, Rodrigo A; Stokes, Trevor L; Thum, Karen; Xu, Xiaodong; Obertello, Mariana; Katari, Manpreet S; Tanurdzic, Milos; Dean, Alexis; Nero, Damion C; McClung, C Robertson; Coruzzi, Gloria M

2008-03-25

Understanding how nutrients affect gene expression will help us to understand the mechanisms controlling plant growth and development as a function of nutrient availability. Nitrate has been shown to serve as a signal for the control of gene expression in Arabidopsis. There is also evidence, on a gene-by-gene basis, that downstream products of nitrogen (N) assimilation such as glutamate (Glu) or glutamine (Gln) might serve as signals of organic N status that in turn regulate gene expression. To identify genome-wide responses to such organic N signals, Arabidopsis seedlings were transiently treated with ammonium nitrate in the presence or absence of MSX, an inhibitor of glutamine synthetase, resulting in a block of Glu/Gln synthesis. Genes that responded to organic N were identified as those whose response to ammonium nitrate treatment was blocked in the presence of MSX. We showed that some genes previously identified to be regulated by nitrate are under the control of an organic N-metabolite. Using an integrated network model of molecular interactions, we uncovered a subnetwork regulated by organic N that included CCA1 and target genes involved in N-assimilation. We validated some of the predicted interactions and showed that regulation of the master clock control gene CCA1 by Glu or a Glu-derived metabolite in turn regulates the expression of key N-assimilatory genes. Phase response curve analysis shows that distinct N-metabolites can advance or delay the CCA1 phase. Regulation of CCA1 by organic N signals may represent a novel input mechanism for N-nutrients to affect plant circadian clock function.

Automatic decoding of facial movements reveals deceptive pain expressions

PubMed Central

Bartlett, Marian Stewart; Littlewort, Gwen C.; Frank, Mark G.; Lee, Kang

2014-01-01

Summary In highly social species such as humans, faces have evolved to convey rich information for social interaction, including expressions of emotions and pain [1–3]. Two motor pathways control facial movement [4–7]. A subcortical extrapyramidal motor system drives spontaneous facial expressions of felt emotions. A cortical pyramidal motor system controls voluntary facial expressions. The pyramidal system enables humans to simulate facial expressions of emotions not actually experienced. Their simulation is so successful that they can deceive most observers [8–11]. Machine vision may, however, be able to distinguish deceptive from genuine facial signals by identifying the subtle differences between pyramidally and extrapyramidally driven movements. Here we show that human observers could not discriminate real from faked expressions of pain better than chance, and after training, improved accuracy to a modest 55%. However a computer vision system that automatically measures facial movements and performs pattern recognition on those movements attained 85% accuracy. The machine system’s superiority is attributable to its ability to differentiate the dynamics of genuine from faked expressions. Thus by revealing the dynamics of facial action through machine vision systems, our approach has the potential to elucidate behavioral fingerprints of neural control systems involved in emotional signaling. PMID:24656830

Long noncoding RNA derived from CD244 signaling epigenetically controls CD8+ T-cell immune responses in tuberculosis infection

PubMed Central

Wang, Yang; Zhong, Huiling; Xie, Xiaodan; Chen, Crystal Y.; Huang, Dan; Shen, Ling; Zhang, Hui; Chen, Zheng W.; Zeng, Gucheng

2015-01-01

Molecular mechanisms for T-cell immune responses modulated by T cell-inhibitory molecules during tuberculosis (TB) infection remain unclear. Here, we show that active human TB infection up-regulates CD244 and CD244 signaling-associated molecules in CD8+ T cells and that blockade of CD244 signaling enhances production of IFN-γ and TNF-α. CD244 expression/signaling in TB correlates with high levels of a long noncoding RNA (lncRNA)-BC050410 [named as lncRNA-AS-GSTT1(1-72) or lncRNA-CD244] in the CD244+CD8+ T-cell subpopulation. CD244 signaling drives lncRNA-CD244 expression via sustaining a permissive chromatin state in the lncRNA-CD244 locus. By recruiting polycomb protein enhancer of zeste homolog 2 (EZH2) to infg/tnfa promoters, lncRNA-CD244 mediates H3K27 trimethylation at infg/tnfa loci toward repressive chromatin states and inhibits IFN-γ/TNF-α expression in CD8+ T cells. Such inhibition can be reversed by knock down of lncRNA-CD244. Interestingly, adoptive transfer of lncRNA-CD244–depressed CD8+ T cells to Mycobacterium tuberculosis (MTB)-infected mice reduced MTB infection and TB pathology compared with lncRNA-CD244–expressed controls. Thus, this work uncovers previously unidentified mechanisms in which T cell-inhibitory signaling and lncRNAs regulate T-cell responses and host defense against TB infection. PMID:26150504

Expression of Magnaporthe grisea Avirulence Gene ACE1 Is Connected to the Initiation of Appressorium-Mediated Penetration▿

PubMed Central

Fudal, Isabelle; Collemare, Jérôme; Böhnert, Heidi U.; Melayah, Delphine; Lebrun, Marc-Henri

2007-01-01

Magnaporthe grisea is responsible for a devastating fungal disease of rice called blast. Current control of this disease relies on resistant rice cultivars that recognize M. grisea signals corresponding to specific secreted proteins encoded by avirulence genes. The M. grisea ACE1 avirulence gene differs from others, since it controls the biosynthesis of a secondary metabolite likely recognized by rice cultivars carrying the Pi33 resistance gene. Using a transcriptional fusion between ACE1 promoter and eGFP, we showed that ACE1 is only expressed in appressoria during fungal penetration into rice and barley leaves, onion skin, and cellophane membranes. ACE1 is almost not expressed in appressoria differentiated on Teflon and Mylar artificial membranes. ACE1 expression is not induced by cellophane and plant cell wall components, demonstrating that it does not require typical host plant compounds. Cyclic AMP (cAMP) signaling mutants ΔcpkA and Δmac1 sum1-99 and tetraspanin mutant Δpls1::hph differentiate melanized appressoria with normal turgor but are unable to penetrate host plant leaves. ACE1 is normally expressed in these mutants, suggesting that it does not require cAMP signaling or a successful penetration event. ACE1 is not expressed in appressoria of the buf1::hph mutant defective for melanin biosynthesis and appressorial turgor. The addition of hyperosmotic solutes to buf1::hph appressoria restores appressorial development and ACE1 expression. Treatments of young wild-type appressoria with actin and tubulin inhibitors reduce both fungal penetration and ACE1 expression. These experiments suggest that ACE1 appressorium-specific expression does not depend on host plant signals but is connected to the onset of appressorium-mediated penetration. PMID:17142568

Cathelicidin Signaling via the Toll-Like Receptor Protects Against Colitis in Mice

PubMed Central

Koon, Hon Wai; Shih, David Quan; Chen, Jeremy; Bakirtzi, Kyriaki; Hing, Tressia C; Law, Ivy; Ho, Samantha; Ichikawa, Ryan; Zhao, Dezheng; Xu, Hua; Gallo, Richard; Dempsey, Paul; Cheng, Genhong; Targan, Stephan R; Pothoulakis, Charalabos

2011-01-01

Background & Aims Cathelicidin (encoded by Camp) is an anti-microbial peptide in the innate immune system. We examined whether macrophages express cathelicidin in colons of mice with experimental colitis and patients with inflammatory bowel disease; we investigated its signaling mechanisms. Methods Quantitative, real-time, reverse transcription PCR, bacterial 16S PCR, immunofluorescence, and small interfering (si)RNA analyses were performed. Colitis was induced in mice using sodium dextran sulfate (DSS); levels of cathelicidin were measured in human primary monocytes. Results Expression of cathelicidin increased in the inflamed colonic mucosa of mice with DSS-induced colitis, compared with controls. Cathelicidin expression localized to mucosal macrophages in inflamed colon tissues of patients and mice. Exposure of human primary monocytes to E coli DNA induced expression of Camp mRNA, which required signaling by ERK; expression was reduced by siRNAs against toll-like receptor (TLR)9 and MyD88. Intracolonic administration of bacterial DNA to wild-type mice induced expression of cathelicidin in colons of control mice and mice with DSS-induced colitis. Colon expression of cathelicidin was significantly reduced in TLR9 −/− mice with DSS-induced colitis. Compared with wild-type mice, Camp −/− mice developed a more severe form of DSS-induced colitis, particularly after intracolonic administration of E coli DNA. Expression of cathelicidin from bone marrow-derived immune cells regulated DSS induction of colitis in transplantation studies in mice. Conclusions Cathelicidin protects against colitis induction in mice. Increased expression of cathelicidin in monocytes and experimental models of colitis involves activation of TLR9–ERK signaling by bacterial DNA. This pathway might be involved in pathogenesis of ulcerative colitis. PMID:21762664

Control, responses and modularity of cellular regulatory networks: a control analysis perspective.

PubMed

Bruggeman, F J; Snoep, J L; Westerhoff, H V

2008-11-01

Cells adapt to changes in environmental conditions through the concerted action of signalling, gene expression and metabolic subsystems. The authors will discuss a theoretical framework addressing such integrated systems. This 'hierarchical analysis' was first developed as an extension to a metabolic control analysis. It builds on the phenomenon that often the communication between signalling, gene expression and metabolic subsystems is almost exclusively via regulatory interactions and not via mass flow interactions. This allows for the treatment of the said subsystems as 'levels' in a hierarchical view of the organisation of the molecular reaction network of cells. Such a hierarchical approach has as a major advantage that levels can be analysed conceptually in isolation of each other (from a local intra-level perspective) and at a later stage integrated via their interactions (from a global inter-level perspective). Hereby, it allows for a modular approach with variable scope. A number of different approaches have been developed for the analysis of hierarchical systems, for example hierarchical control analysis and modular response analysis. The authors, here, review these methods and illustrate the strength of these types of analyses using a core model of a system with gene expression, metabolic and signal transduction levels.

Redox control of protein-DNA interactions: from molecular mechanisms to significance in signal transduction, gene expression, and DNA replication.

PubMed

Shlomai, Joseph

2010-11-01

Protein-DNA interactions play a key role in the regulation of major cellular metabolic pathways, including gene expression, genome replication, and genomic stability. They are mediated through the interactions of regulatory proteins with their specific DNA-binding sites at promoters, enhancers, and replication origins in the genome. Redox signaling regulates these protein-DNA interactions using reactive oxygen species and reactive nitrogen species that interact with cysteine residues at target proteins and their regulators. This review describes the redox-mediated regulation of several master regulators of gene expression that control the induction and suppression of hundreds of genes in the genome, regulating multiple metabolic pathways, which are involved in cell growth, development, differentiation, and survival, as well as in the function of the immune system and cellular response to intracellular and extracellular stimuli. It also discusses the role of redox signaling in protein-DNA interactions that regulate DNA replication. Specificity of redox regulation is discussed, as well as the mechanisms providing several levels of redox-mediated regulation, from direct control of DNA-binding domains through the indirect control, mediated by release of negative regulators, regulation of redox-sensitive protein kinases, intracellular trafficking, and chromatin remodeling.

Cognitive Endophenotypes Inform Genome-Wide Expression Profiling in Schizophrenia

PubMed Central

Zheutlin, Amanda B.; Viehman, Rachael W.; Fortgang, Rebecca; Borg, Jacqueline; Smith, Desmond J.; Suvisaari, Jaana; Therman, Sebastian; Hultman, Christina M.; Cannon, Tyrone D.

2015-01-01

OBJECTIVE We performed a whole-genome expression study to clarify the nature of the biological processes mediating between inherited genetic variations and cognitive dysfunction in schizophrenia. METHOD Gene expression was assayed from peripheral blood mononuclear cells using Illumina Human WG6 v3.0 chips in twins discordant for schizophrenia or bipolar disorder and control twins. After quality control, expression levels of 18,559 genes were screened for association with California Verbal Learning Test (CVLT) performance, and any memory-related probes were then evaluated for variation by diagnostic status in the discovery sample (N = 190), and in an independent replication sample (N = 73). Heritability of gene expression using the twin design was also assessed. RESULTS After Bonferroni correction (p < 2.69 × 10−6), CVLT performance was significantly related to expression levels for 76 genes, 43 of which were differentially expressed in schizophrenia patients, with comparable effect sizes in the same direction in the replication sample. For 41 of these 43 transcripts, expression levels were heritable. Nearly all identified genes contain common or de novo mutations associated with schizophrenia in prior studies. CONCLUSION Genes increasing risk for schizophrenia appear to do so in part via effects on signaling cascades influencing memory. The genes implicated in these processes are enriched for those related to RNA processing and DNA replication and include genes influencing G-protein coupled signal transduction, cytokine signaling, and oligodendrocyte function. PMID:26710095

Cognitive endophenotypes inform genome-wide expression profiling in schizophrenia.

PubMed

Zheutlin, Amanda B; Viehman, Rachael W; Fortgang, Rebecca; Borg, Jacqueline; Smith, Desmond J; Suvisaari, Jaana; Therman, Sebastian; Hultman, Christina M; Cannon, Tyrone D

2016-01-01

We performed a whole-genome expression study to clarify the nature of the biological processes mediating between inherited genetic variations and cognitive dysfunction in schizophrenia. Gene expression was assayed from peripheral blood mononuclear cells using Illumina Human WG6 v3.0 chips in twins discordant for schizophrenia or bipolar disorder and control twins. After quality control, expression levels of 18,559 genes were screened for association with the California Verbal Learning Test (CVLT) performance, and any memory-related probes were then evaluated for variation by diagnostic status in the discovery sample (N = 190), and in an independent replication sample (N = 73). Heritability of gene expression using the twin design was also assessed. After Bonferroni correction (p < 2.69 × 10-6), CVLT performance was significantly related to expression levels for 76 genes, 43 of which were differentially expressed in schizophrenia patients, with comparable effect sizes in the same direction in the replication sample. For 41 of these 43 transcripts, expression levels were heritable. Nearly all identified genes contain common or de novo mutations associated with schizophrenia in prior studies. Genes increasing risk for schizophrenia appear to do so in part via effects on signaling cascades influencing memory. The genes implicated in these processes are enriched for those related to RNA processing and DNA replication and include genes influencing G-protein coupled signal transduction, cytokine signaling, and oligodendrocyte function. (c) 2015 APA, all rights reserved).

Leptin signaling and leptin resistance

PubMed Central

Zhou, Yingjiang; Rui, Liangyou

2014-01-01

Leptin is secreted into the bloodstream by adipocytes and is required for the maintenance of energy homeostasis and body weight. Leptin deficiency or genetic defects in the components of the leptin signaling pathways causes obesity. Leptin controls energy balance and body weight primarily by targeting LEPRb-expressing neurons in the brain, particularly in the hypothalamus. These LEPRb-expressing neurons function as the first-order neurons that project to the second-order neurons located within and outside the hypothalamus, forming a neural network that controls the energy homeostasis and body weight. Multiple factors, including inflammation and ER stress, contribute to leptin resistance, and leptin resistance is the key risk factor for obesity. This review is focused on recent advance about leptin action, leptin signaling, and leptin resistance. PMID:23580174

Tbx6-mediated Notch signaling controls somite-specific Mesp2 expression

PubMed Central

Yasuhiko, Yukuto; Haraguchi, Seiki; Kitajima, Satoshi; Takahashi, Yu; Kanno, Jun; Saga, Yumiko

2006-01-01

Mesp2 is a transcription factor that plays fundamental roles in somitogenesis, and its expression is strictly restricted to the anterior presomitic mesoderm just before segment border formation. The transcriptional on–off cycle is linked to the segmentation clock. In our current study, we show that a T-box transcription factor, Tbx6, is essential for Mesp2 expression. Tbx6 directly binds to the Mesp2 gene upstream region and mediates Notch signaling, and subsequent Mesp2 transcription, in the anterior presomitic mesoderm. Our data therefore reveal that a mechanism, via Tbx6-dependent Notch signaling, acts on the transcriptional regulation of Mesp2. This finding uncovers an additional component of the interacting network of various signaling pathways that are involved in somitogenesis. PMID:16505380

Formation and differentiation of the avian sclerotome.

PubMed

Christ, Bodo; Huang, Ruijin; Scaal, Martin

2004-08-01

The avian sclerotome forms by epitheliomesenchymal transition of the ventral half-somite. Sclerotome development is characterized by a craniocaudal polarization, resegmentation, and axial identity. Its formation is controlled by signals from the notochord, the neural tube, the lateral plate mesoderm, and the myotome. These signals and crosstalk between somite cells lead to the separation of various subdomains, such as the central and ventral sclerotomes that express Pax1 under the control of Sonic hedgehog and Noggin, and the dorsal and lateral sclerotome that do not express Pax1 and are controlled by Bmp-4. Further subdomains that give rise to specific derivatives are the syndetome, neurotome, meningotome, and arthrotome. The molecular control of subdomain formation and cell type specification is discussed. Copyright 2004 Springer-Verlag

Congenitally learned helpless rats show abnormalities in intracellular signaling.

PubMed

Kohen, Ruth; Neumaier, John F; Hamblin, Mark W; Edwards, Emmeline

2003-03-15

Affective disorders and the drugs used to treat them lead to changes in intracellular signaling. We used a genetic animal model to investigate to what extent changes in intracellular signal transduction confer a vulnerability to mood or anxiety disorders. Levels of gene expression in a selectively bred strain of rats with a high vulnerability to develop congenitally learned helplessness (cLH), a strain highly resistant to the same behavior (cNLH) and outbred Sprague-Dawley (SD) control animals were compared using quantitative reverse transcription polymerase chain reaction. Congenitally learned helpless animals had a 24%-30% reduced expression of the cyclic adenosine monophosphate response element binding protein messenger ribonucleic acid (mRNA) in the hippocampus and a 40%-41% increased level of the antiapoptotic protein bcl-2 mRNA in the prefrontal cortex compared to cNLH and SD rats. Other significant changes included changes in the expression levels of the alpha catalytic subunit of protein kinase A, glycogen synthase kinase 3beta, and protein kinase C epsilon. Congenitally learned helpless animals show evidence of altered signal transduction and regulation of apoptosis compared to cNLH and SD control animals.

Xenopus Zic3 controls notochord and organizer development through suppression of the Wnt/β-catenin signaling pathway.

PubMed

Fujimi, Takahiko J; Hatayama, Minoru; Aruga, Jun

2012-01-15

Zic3 controls neuroectodermal differentiation and left-right patterning in Xenopus laevis embryos. Here we demonstrate that Zic3 can suppress Wnt/β-catenin signaling and control development of the notochord and Spemann's organizer. When we overexpressed Zic3 by injecting its RNA into the dorsal marginal zone of 2-cell-stage embryos, the embryos lost mesodermal dorsal midline structures and showed reduced expression of organizer markers (Siamois and Goosecoid) and a notochord marker (Xnot). Co-injection of Siamois RNA partially rescued the reduction of Xnot expression caused by Zic3 overexpression. Because the expression of Siamois in the organizer region is controlled by Wnt/β-catenin signaling, we subsequently examined the functional interaction between Zic3 and Wnt signaling. Co-injection of Xenopus Zic RNAs and β-catenin RNA with a reporter responsive to the Wnt/β-catenin cascade indicated that Zic1, Zic2, Zic3, Zic4, and Zic5 can all suppress β-catenin-mediated transcriptional activation. In addition, co-injection of Zic3 RNA inhibited the secondary axis formation caused by ventral-side injection of β-catenin RNA in Xenopus embryos. Zic3-mediated Wnt/β-catenin signal suppression required the nuclear localization of Zic3, and involved the reduction of β-catenin nuclear transport and enhancement of β-catenin degradation. Furthermore, Zic3 co-precipitated with Tcf1 (a β-catenin co-factor) and XIC (I-mfa domain containing factor required for dorsoanterior development). The findings in this report produce a novel system for fine-tuning of Wnt/β-catenin signaling. Copyright © 2011. Published by Elsevier Inc.

Effects of gene knockdown of CNP on ventricular remodeling after myocardial ischemia-reperfusion injury through NPRB/Cgmp signaling pathway in rats.

PubMed

Wu, Lian-He; Zhang, Qi; Zhang, Shen; Meng, Lu-Yu; Wang, Yan-Chi; Sheng, Cun-Jian

2018-02-01

This study aimed to explore effects of CNP on ventricular remodeling following myocardial ischemia-reperfusion (I/R) injury through the NPRB/cGMP signaling pathway. Rat cardiomyocytes were assigned into: control, I/R, I/R + CNP, and I/R + 8-Br-cGMP groups. ELISA, qRT-PCR, and Western blotting were used to detect cGMP content and expression, respectively. After model establishment of I/R rats, normal control, CNP -/- control, I/R, and CNP -/- groups were set. Indexes of heart were detected using echocardiography and hemodynamics. ELISA was used to measure serum CNP, cGMP, LDH, cTn I, CK-MB, TNF-α, and IL-6 levels. Myocardial infarct was identified by TTC staining, and apoptosis conditions by TUNEL staining. QRT-PCR and Western blotting were adopted to detect expressions of CNP, NPRB, cGMP, and apoptosis-related genes. Compared with control group, cGMP contents and expression in the I/R, I/R + CNP and I/R + 8-Br-cGMP groups were decreased. Levels of LVEDV, LVESV, LVDS, LVDD, IVSD, LVM, LVEDP, and LVSP were higher in the I/R, CNP -/- control, and CNP -/- groups than normal control group while LVEF, SV, CO, and ±dp/dtmax were lower. Compared with the normal control group, LDH, cTn I, CK-MB, TNF-α, and IL-6 were higher in the I/R, CNP -/- control and CNP -/- groups; pathological changes and myocardial infarction were observed in the I/R, CNP -/- control, and CNP -/- groups; expressions of apoptosis-related genes in those groups were higher; while CNP, NPRB, cGMP, and Bcl-2 expressions were decreased. We came to the conclusion that gene knockdown of CNP blocks the NPRB/cGMP signaling pathway, thereby aggravating myocardial I/R injury and causing ventricular remodeling in rats. © 2017 Wiley Periodicals, Inc.

In tobacco BY-2 cells xyloglucan oligosaccharides alter the expression of genes involved in cell wall metabolism, signalling, stress responses, cell division and transcriptional control.

PubMed

González-Pérez, Lien; Perrotta, Lara; Acosta, Alexis; Orellana, Esteban; Spadafora, Natasha; Bruno, Leonardo; Bitonti, Beatrice M; Albani, Diego; Cabrera, Juan Carlos; Francis, Dennis; Rogers, Hilary J

2014-10-01

Xyloglucan oligosaccharides (XGOs) are breakdown products of XGs, the most abundant hemicelluloses of the primary cell walls of non-Poalean species. Treatment of cell cultures or whole plants with XGOs results in accelerated cell elongation and cell division, changes in primary root growth, and a stimulation of defence responses. They may therefore act as signalling molecules regulating plant growth and development. Previous work suggests an interaction with auxins and effects on cell wall loosening, however their mode of action is not fully understood. The effect of an XGO extract from tamarind (Tamarindus indica) on global gene expression was therefore investigated in tobacco BY-2 cells using microarrays. Over 500 genes were differentially regulated with similar numbers and functional classes of genes up- and down-regulated, indicating a complex interaction with the cellular machinery. Up-regulation of a putative XG endotransglycosylase/hydrolase-related (XTH) gene supports the mechanism of XGO action through cell wall loosening. Differential expression of defence-related genes supports a role for XGOs as elicitors. Changes in the expression of genes related to mitotic control and differentiation also support previous work showing that XGOs are mitotic inducers. XGOs also affected expression of several receptor-like kinase genes and transcription factors. Hence, XGOs have significant effects on expression of genes related to cell wall metabolism, signalling, stress responses, cell division and transcriptional control.

Atorvastatin attenuates experimental contrast-induced acute kidney injury: a role for TLR4/MyD88 signaling pathway.

PubMed

Yue, Rongzheng; Zuo, Chuan; Zeng, Jing; Su, Baihai; Tao, Ye; Huang, Songmin; Zeng, Rui

2017-11-01

To investigate the protective effect of different atorvastatin doses on contrast-induced acute kidney injury and the related mechanism. Healthy male Sprague-Dawley (SD) rats were randomly divided into the blank control group, experimental control group and different-dose atorvastatin groups. A rat model of contrast-induced acute kidney injury was established. We detected changes in serum creatinine (Scr) and blood urea nitrogen (BUN) before and after model establishment, observed and scored renal tubular injury, analyzed rat renal cell apoptosis, and measure the expression of signal pathway proteins and downstream inflammatory factors. After contrast agent injection, the Scr and BUN levels of the experimental control group were significantly increased, the different doses applied in the atorvastatin group significantly reduced the Scr and BUN levels (p < .05) and ameliorated the contrast-induced acute kidney injury (p < .05) and significantly reduced Toll-like receptor 4 (TLR4), Myeloid differentiation factor 88 (Myd88), and Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) protein expression and relative mRNA expression levels (p < .05) and significantly decreased expression levels of downstream inflammatory factors (p < .05). Different atorvastatin doses have protective effects on contrast-induced acute renal tubular injury in rats, possibly by targeting TLR4, suppressing TLR4 expression, regulating the TLR4/Myd88 signaling pathway, and inhibiting the expression of downstream inflammatory factors.

Traditional Chinese medicine suppresses left ventricular hypertrophy by targeting extracellular signal-regulated kinases signaling pathway in spontaneously hypertensive rats

PubMed Central

Xiong, Xingjiang; Yang, Xiaochen; Duan, Lian; Liu, Wei; Zhang, Yun; Liu, Yongmei; Wang, Pengqian; Li, Shengjie; Li, Xiaoke

2017-01-01

Chinese herbal medicine Bu-Shen-Jiang-Ya decoction (BSJYD) is reported to be beneficial for hypertension. Over expression of extracellular signal regulated kinases (ERK) pathway plays an important role in left ventricular hypertrophy (LVH). This study aimed to observe effects of BSJYD on LVH in spontaneously hypertensive rats (SHRs) and explore its possible mechanism on regulation of ERK pathway. Sixty 12-week-old SHRs were randomly allocated into 5 groups: BSJYD high dose group, middle dose group, low dose group, captopril group, and control group. Besides, a control group of Wistar-Kyoto rats was established. All rats were treated for 8 weeks. Systolic blood pressure (SBP), heart rate (HR), pathology, and left ventricular mass index (LVMI) were measured. Western blotting and Real-time PCR were used to assess the expressions of BDNF, Ras, ERK1/2, and c-fox levels. SBP and HR were significantly decreased compared with the control group and LVMI was markedly improved by BSJYD treatment in a dose-dependent manner. BSJYD inhibited the expression of BDNF, Ras, ERK1/2, and c-fox mRNA in LVH. In conclusion, BSJYD suppressed hypertension-induced cardiac hypertrophy by inhibiting the expression of ERK pathway. These changes in gene expression may be a possible mechanism by which BSJYD provides myocardial protection from hypertension. PMID:28225023

Effect of saw palmetto extract on PI3K cell signaling transduction in human glioma.

PubMed

Yang, Yang; Hui, Lv; Yuqin, Che; Jie, Li; Shuai, Hou; Tiezhu, Zhou; Wei, Wang

2014-08-01

Saw palmetto extract can induce the apoptosis of prostate cancer cells. The aim of the present study was to investigate the effect of saw palmetto extract on the phosphatidylinositol 3-kinase (PI3K)/Akt signaling transduction pathway in human glioma U87 and U251 cell lines. Suspensions of U87 and U251 cells in a logarithmic growth phase were seeded into six-well plates at a density of 10 4 cells/well. In the experimental group, 1 μl/ml saw palmetto extract was added, while the control group was cultured without a drug for 24 h. The expression levels of PI3K, B-cell lymphoma-extra large (Bcl-xL) and p53 were evaluated through western blot analysis. In the experimental group, the U87 and U251 cells exhibited a lower expression level of PI3K protein as compared with the control group (t=6.849; P<0.001). In addition, the two cell lines had a higher expression level of p53 protein in the experimental group as compared with the control group (t=40.810; P<0.001). Protein expression levels of Bcl-xL decreased significantly in the experimental group as compared with the control group (t=19.640; P=0.000). Therefore, saw palmetto extract induces glioma cell growth arrest and apoptosis via decreasing PI3K/Akt signal transduction.

EMMPRIN regulates tumor growth and metastasis by recruiting bone marrow-derived cells through paracrine signaling of SDF-1 and VEGF

PubMed Central

Chen, Yanke; Gou, Xingchun; Kong, Derek Kai; Wang, Xiaofei; Wang, Jianhui; Chen, Zeming; Huang, Chen; Zhou, Jiangbing

2015-01-01

EMMPRIN, a cell adhesion molecule highly expressed in a variety of tumors, is associated with poor prognosis in cancer patients. Mechanistically, EMMPRIN has been characterized to contribute to tumor development and progression by controlling the expression of MMPs and VEGF. In the present study, by using fluorescently labeled bone marrow-derived cells (BMDCs), we found that the down-regulation of EMMPRIN expression in cancer cells reduces tumor growth and metastasis, and is associated with the reduced recruitment of BMDCs. Further protein profiling studies suggest that EMMPRIN controls BMDC recruitment through regulating the secretion of soluble factors, notably, VEGF and SDF-1. We demonstrate that the expression and secretion of SDF-1 in tumor cells are regulated by EMMPRIN. This study reveals a novel mechanism by which EMMPRIN promotes tumor growth and metastasis by recruitment of BMDCs through controlling secretion and paracrine signaling of SDF-1 and VEGF. PMID:26416452

Alendronate promotes osteoblast differentiation and bone formation in ovariectomy-induced osteoporosis through interferon-β/signal transducer and activator of transcription 1 pathway

PubMed Central

Ma, Xiaoqing; Xu, Zhongyang; Ding, Shaofeng; Yi, Guangkun; Wang, Qian

2018-01-01

Alendronate is commonly used for the treatment of postmenopausal osteoporosis; however, the underlying pathological molecular mechanisms of its action remain unclear. In the present study, the alendronate-treated signaling pathway in bone metabolism in rats with ovariectomy induced by osteoporosis was investigated. Rats with osteoporosis were orally administered alendronate or phosphate-buffered saline (control). In addition, the interferon-β (IFN-β)/signal transducer and activator of transcription 1 (STAT1) signaling pathway was investigated in osteoblasts following treatment with alendronate in vitro and in vivo. During the differentiation period, IFN-β (100 ng/ml) was used to treat the osteoblast cells, and the activity, viability and bone metabolism-associated gene expression levels (STAT1, p-STAT1, Fra1, TRAF6 and SOCS1) were analyzed in osteoblast cells. Histopathological changes were used to evaluate osteoblasts, osteoclasts, inflammatory phase of bone healing and osteonecrotic areas. The results demonstrated that alendronate significantly inhibited the activity of osteoporotic osteoclasts by stimulating expression of IFN-β, as well as markedly improved the viability and activity of osteoblasts compared with the control group. In addition, alendronate increased the expression and phosphorylation levels of STAT1 in osteoclasts, enhanced osteoblast differentiation, upregulated the expression levels of alkaline phosphatase and osteocalcin, and increased the expression of osteoblast differentiation-associated genes (osteocalcin, osterix and Runx2). Inhibition of IFN-β expression canceled the benefits of alendronate-mediated osteoblast differentiation. Notably, alendronate enhanced bone formation in rats with osteoporosis induced by ovariectomy. In conclusion, these findings suggest that alendronate can regulate osteoblast differentiation and bone formation in rats with osteoporosis induced by ovariectomy through upregulation of IFN-β/STAT1 signaling pathway. PMID:29375681

Transcriptome Analysis of Orbital Adipose Tissue in Active Thyroid Eye Disease Using Next Generation RNA Sequencing Technology

PubMed Central

Lee, Bradford W.; Kumar, Virender B.; Biswas, Pooja; Ko, Audrey C.; Alameddine, Ramzi M.; Granet, David B.; Ayyagari, Radha; Kikkawa, Don O.; Korn, Bobby S.

2018-01-01

Objective: This study utilized Next Generation Sequencing (NGS) to identify differentially expressed transcripts in orbital adipose tissue from patients with active Thyroid Eye Disease (TED) versus healthy controls. Method: This prospective, case-control study enrolled three patients with severe, active thyroid eye disease undergoing orbital decompression, and three healthy controls undergoing routine eyelid surgery with removal of orbital fat. RNA Sequencing (RNA-Seq) was performed on freshly obtained orbital adipose tissue from study patients to analyze the transcriptome. Bioinformatics analysis was performed to determine pathways and processes enriched for the differential expression profile. Quantitative Reverse Transcriptase-Polymerase Chain Reaction (qRT-PCR) was performed to validate the differential expression of selected genes identified by RNA-Seq. Results: RNA-Seq identified 328 differentially expressed genes associated with active thyroid eye disease, many of which were responsible for mediating inflammation, cytokine signaling, adipogenesis, IGF-1 signaling, and glycosaminoglycan binding. The IL-5 and chemokine signaling pathways were highly enriched, and very-low-density-lipoprotein receptor activity and statin medications were implicated as having a potential role in TED. Conclusion: This study is the first to use RNA-Seq technology to elucidate differential gene expression associated with active, severe TED. This study suggests a transcriptional basis for the role of statins in modulating differentially expressed genes that mediate the pathogenesis of thyroid eye disease. Furthermore, the identification of genes with altered levels of expression in active, severe TED may inform the molecular pathways central to this clinical phenotype and guide the development of novel therapeutic agents. PMID:29760827

Expression profiles of mRNA and long noncoding RNA in the ovaries of letrozole-induced polycystic ovary syndrome rat model through deep sequencing.

PubMed

Fu, Lu-Lu; Xu, Ying; Li, Dan-Dan; Dai, Xiao-Wei; Xu, Xin; Zhang, Jing-Shun; Ming, Hao; Zhang, Xue-Ying; Zhang, Guo-Qing; Ma, Ya-Lan; Zheng, Lian-Wen

2018-05-30

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in reproductive-aged women. However, the exact pathophysiology of PCOS remains largely unclear. We performed deep sequencing to investigate the mRNA and long noncoding RNA (lncRNA) expression profiles in the ovarian tissues of letrozole-induced PCOS rat model and control rats. A total of 2147 mRNAs and 158 lncRNAs were differentially expressed between the PCOS models and control. Gene ontology analysis indicated that differentially expressed mRNAs were associated with biological adhesion, reproduction, and metabolic process. Pathway analysis results indicated that these aberrantly expressed mRNAs were related to several specific signaling pathways, including insulin resistance, steroid hormone biosynthesis, PPAR signaling pathway, cell adhesion molecules, autoimmune thyroid disease, and AMPK signaling pathway. The relative expression levels of mRNAs and lncRNAs were validated through qRT-PCR. LncRNA-miRNA-mRNA network was constructed to explore ceRNAs involved in the PCOS model and were also verified by qRTPCR experiment. These findings may provide insight into the pathogenesis of PCOS and clues to find key diagnostic and therapeutic roles of lncRNA in PCOS. Copyright © 2018 Elsevier B.V. All rights reserved.

Selecting antagonistic antibodies that control differentiation through inducible expression in embryonic stem cells

PubMed Central

Melidoni, Anna N.; Dyson, Michael R.; Wormald, Sam; McCafferty, John

2013-01-01

Antibodies that modulate receptor function have great untapped potential in the control of stem cell differentiation. In contrast to many natural ligands, antibodies are stable, exquisitely specific, and are unaffected by the regulatory mechanisms that act on natural ligands. Here we describe an innovative system for identifying such antibodies by introducing and expressing antibody gene populations in ES cells. Following induced antibody expression and secretion, changes in differentiation outcomes of individual antibody-expressing ES clones are monitored using lineage-specific gene expression to identify clones that encode and express signal-modifying antibodies. This in-cell expression and reporting system was exemplified by generating blocking antibodies to FGF4 and its receptor FGFR1β, identified through delayed onset of ES cell differentiation. Functionality of the selected antibodies was confirmed by addition of exogenous antibodies to three different ES reporter cell lines, where retained expression of pluripotency markers Oct4, Nanog, and Rex1 was observed. This work demonstrates the potential for discovery and utility of functional antibodies in stem cell differentiation. This work is also unique in constituting an example of ES cells carrying an inducible antibody that causes a functional protein “knock-down” and allows temporal control of stable signaling components at the protein level. PMID:24082130

Innately activated TLR4 signal in the nucleus accumbens is sustained by CRF amplification loop and regulates impulsivity.

PubMed

Balan, Irina; Warnock, Kaitlin T; Puche, Adam; Gondre-Lewis, Marjorie C; Aurelian, Laure

2018-03-01

Cognitive impulsivity is a heritable trait believed to represent the behavior that defines the volition to initiate alcohol drinking. We have previously shown that a neuronal Toll-like receptor 4 (TLR4) signal located in the central amygdala (CeA) and ventral tegmental area (VTA) controls the initiation of binge drinking in alcohol-preferring P rats, and TLR4 expression is upregulated by alcohol-induced corticotropin-releasing factor (CRF) at these sites. However, the function of the TLR4 signal in the nucleus accumbens shell (NAc-shell), a site implicated in the control of reward, drug-seeking behavior and impulsivity and the contribution of other signal-associated genes, are still poorly understood. Here we report that P rats have an innately activated TLR4 signal in NAc-shell neurons that co-express the α2 GABA A receptor subunit and CRF prior to alcohol exposure. This signal is not present in non-alcohol drinking NP rats. The TLR4 signal is sustained by a CRF amplification loop, which includes TLR4-mediated CRF upregulation through PKA/CREB activation and CRF-mediated TLR4 upregulation through the CRF type 1 receptor (CRFR1) and the MAPK/ERK pathway. NAc-shell Infusion of a neurotropic, non-replicating herpes simplex virus vector for TLR4-specific small interfering RNA (pHSVsiTLR4) inhibits TLR4 expression and cognitive impulsivity, implicating the CRF-amplified TLR4 signal in impulsivity regulation. Copyright © 2017 Elsevier Inc. All rights reserved.

A role for Runx transcription factor signaling in dorsal root ganglion sensory neuron diversification.

PubMed

Kramer, Ina; Sigrist, Markus; de Nooij, Joriene C; Taniuchi, Ichiro; Jessell, Thomas M; Arber, Silvia

2006-02-02

Subpopulations of sensory neurons in the dorsal root ganglion (DRG) can be characterized on the basis of sensory modalities that convey distinct peripheral stimuli, but the molecular mechanisms that underlie sensory neuronal diversification remain unclear. Here, we have used genetic manipulations in the mouse embryo to examine how Runx transcription factor signaling controls the acquisition of distinct DRG neuronal subtype identities. Runx3 acts to diversify an Ngn1-independent neuronal cohort by promoting the differentiation of proprioceptive sensory neurons through erosion of TrkB expression in prospective TrkC+ sensory neurons. In contrast, Runx1 controls neuronal diversification within Ngn1-dependent TrkA+ neurons by repression of neuropeptide CGRP expression and controlling the fine pattern of laminar termination in the dorsal spinal cord. Together, our findings suggest that Runx transcription factor signaling plays a key role in sensory neuron diversification.

Induction of CXC chemokines in human mesenchymal stem cells by stimulation with secreted frizzled-related proteins through non-canonical Wnt signaling.

PubMed

Bischoff, David S; Zhu, Jian-Hua; Makhijani, Nalini S; Yamaguchi, Dean T

2015-12-26

To investigate the effect of secreted frizzled-related proteins (sFRPs) on CXC chemokine expression in human mesenchymal stem cells (hMSCs). CXC chemokines such as CXCL5 and CXCL8 are induced in hMSCs during differentiation with osteogenic differentiation medium (OGM) and may be involved in angiogenic stimulation during bone repair. hMSCs were treated with conditioned medium (CM) from L-cells expressing non-canonical Wnt5a protein, or with control CM from wild type L-cells, or directly with sFRPs for up to 10 d in culture. mRNA expression levels of both CXCL5 and CXCL8 were quantitated by real-time reverse transcriptase-polymerase chain reaction and secreted protein levels of these proteins determined by ELISA. Dose- (0-500 ng/mL) and time-response curves were generated for treatment with sFRP1. Signal transduction pathways were explored by western blot analysis with pan- or phosphorylation-specific antibodies, through use of specific pathway inhibitors, and through use of siRNAs targeting specific frizzled receptors (Fzd)-2 and 5 or the receptor tyrosine kinase-like orphan receptor-2 (RoR2) prior to treatment with sFRPs. CM from L-cells expressing Wnt5a, a non-canonical Wnt, stimulated an increase in CXCL5 mRNA expression and protein secretion in comparison to control L-cell CM. sFRP1, which should inhibit both canonical and non-canonical Wnt signaling, surprisingly enhanced the expression of CXCL5 at 7 and 10 d. Dickkopf1, an inhibitor of canonical Wnt signaling prevented the sFRP-stimulated induction of CXCL5 and actually inhibited basal levels of CXCL5 expression at 7 but not at 10 d post treatment. In addition, all four sFRPs isoforms induced CXCL8 expression in a dose- and time-dependent manner with maximum expression at 7 d with treatment at 150 ng/mL. The largest increases in CXCL5 expression were seen from stimulation with sFRP1 or sFRP2. Analysis of mitogen-activated protein kinase signaling pathways in the presence of OGM showed sFRP1-induced phosphorylation of extracellular signal-regulated kinase (ERK) (p44/42) maximally at 5 min after sFRP1 addition, earlier than that found in OGM alone. Addition of a phospholipase C (PLC) inhibitor also prevented sFRP-stimulated increases in CXCL8 mRNA. siRNA technology targeting the Fzd-2 and 5 and the non-canonical Fzd co-receptor RoR2 also significantly decreased sFRP1/2-stimulated CXCL8 mRNA levels. CXC chemokine expression in hMSCs is controlled in part by sFRPs signaling through non-canonical Wnt involving Fzd2/5 and the ERK and PLC pathways.

Induction of CXC chemokines in human mesenchymal stem cells by stimulation with secreted frizzled-related proteins through non-canonical Wnt signaling

PubMed Central

Bischoff, David S; Zhu, Jian-Hua; Makhijani, Nalini S; Yamaguchi, Dean T

2015-01-01

AIM: To investigate the effect of secreted frizzled-related proteins (sFRPs) on CXC chemokine expression in human mesenchymal stem cells (hMSCs). METHODS: CXC chemokines such as CXCL5 and CXCL8 are induced in hMSCs during differentiation with osteogenic differentiation medium (OGM) and may be involved in angiogenic stimulation during bone repair. hMSCs were treated with conditioned medium (CM) from L-cells expressing non-canonical Wnt5a protein, or with control CM from wild type L-cells, or directly with sFRPs for up to 10 d in culture. mRNA expression levels of both CXCL5 and CXCL8 were quantitated by real-time reverse transcriptase-polymerase chain reaction and secreted protein levels of these proteins determined by ELISA. Dose- (0-500 ng/mL) and time-response curves were generated for treatment with sFRP1. Signal transduction pathways were explored by western blot analysis with pan- or phosphorylation-specific antibodies, through use of specific pathway inhibitors, and through use of siRNAs targeting specific frizzled receptors (Fzd)-2 and 5 or the receptor tyrosine kinase-like orphan receptor-2 (RoR2) prior to treatment with sFRPs. RESULTS: CM from L-cells expressing Wnt5a, a non-canonical Wnt, stimulated an increase in CXCL5 mRNA expression and protein secretion in comparison to control L-cell CM. sFRP1, which should inhibit both canonical and non-canonical Wnt signaling, surprisingly enhanced the expression of CXCL5 at 7 and 10 d. Dickkopf1, an inhibitor of canonical Wnt signaling prevented the sFRP-stimulated induction of CXCL5 and actually inhibited basal levels of CXCL5 expression at 7 but not at 10 d post treatment. In addition, all four sFRPs isoforms induced CXCL8 expression in a dose- and time-dependent manner with maximum expression at 7 d with treatment at 150 ng/mL. The largest increases in CXCL5 expression were seen from stimulation with sFRP1 or sFRP2. Analysis of mitogen-activated protein kinase signaling pathways in the presence of OGM showed sFRP1-induced phosphorylation of extracellular signal-regulated kinase (ERK) (p44/42) maximally at 5 min after sFRP1 addition, earlier than that found in OGM alone. Addition of a phospholipase C (PLC) inhibitor also prevented sFRP-stimulated increases in CXCL8 mRNA. siRNA technology targeting the Fzd-2 and 5 and the non-canonical Fzd co-receptor RoR2 also significantly decreased sFRP1/2-stimulated CXCL8 mRNA levels. CONCLUSION: CXC chemokine expression in hMSCs is controlled in part by sFRPs signaling through non-canonical Wnt involving Fzd2/5 and the ERK and PLC pathways. PMID:26730270

Differential insulin and steroidogenic signaling in insulin resistant and non-insulin resistant human luteinized granulosa cells-A study in PCOS patients.

PubMed

Belani, Muskaan; Deo, Abhilash; Shah, Preeti; Banker, Manish; Singal, Pawan; Gupta, Sarita

2018-04-01

Insulin resistance (IR) is one of the significant aberrations in polycystic ovarian syndrome (PCOS), however is only observed in 70%-80% of obese PCOS and 20%-25% of lean PCOS. Hyperinsulinemia accompanies PCOS-IR along with hyperandrogenemia against normal insulin and androgen levels in PCOS-non insulin resistance (NIR). This could possibly be due to defects in the downstream signaling pathways. The study thus aims to unravel insulin and steroidogenic signaling pathways in luteinized granulosa cells isolated from PCOS-IR and NIR vs matched controls. Luteinized granulosa cells from 30 controls and 39 PCOS were classified for IR based on a novel method of down regulation of protein expression of insulin receptor-β (INSR- β) as shown in our previous paper. We evaluated expression of molecules involved in insulin, steroidogenic signaling and lipid metabolism in luteinized granulosa cells followed by analysis of estradiol, progesterone and testosterone in follicular fluid. Protein expression of INSR- β, pIRS (ser 307), PI(3)K, PKC-ζ, pAkt, ERK1/2, pP38MAPK and gene expression of IGF showed differential expression in the two groups. Increased protein expression of PPAR-γ was accompanied by up regulation in SREBP1c, FAS, CPT-1 and ACC-1 genes in PCOS-IR group. Expression of StAR, CYP19A1, 17 β- HSD and 3 β- HSD demonstrated significant decrease along with increase in CYP11A1, FSH-R and LH-R in both the groups. Follicular fluid testosterone increased and progesterone decreased in PCOS-IR group. This study shows how candidate molecules that were differentially expressed, aid in designing targeted therapy against the two phenotypes of PCOS. Copyright © 2018 Elsevier Ltd. All rights reserved.

Neurotrophic regulation of epidermal dedifferentiation during wound healing and limb regeneration in the axolotl (Ambystoma mexicanum).

PubMed

Satoh, A; Graham, G M C; Bryant, S V; Gardiner, D M

2008-07-15

Adult urodeles (salamanders) are unique in their ability to regenerate complex organs perfectly. The recently developed Accessory Limb Model (ALM) in the axolotl provides an opportunity to identify and characterize the essential signaling events that control the early steps in limb regeneration. The ALM demonstrates that limb regeneration progresses in a stepwise fashion that is dependent on signals from the wound epidermis, nerves and dermal fibroblasts from opposite sides of the limb. When all the signals are present, a limb is formed de novo. The ALM thus provides an opportunity to identify and characterize the signaling pathways that control blastema morphogenesis and limb regeneration. In the present study, we have utilized the ALM to identity the buttonhead-like zinc-finger transcription factor, Sp9, as being involved in the formation of the regeneration epithelium. Sp9 expression is induced in basal keratinocytes of the apical blastema epithelium in a pattern that is comparable to its expression in developing limb buds, and it thus is an important marker for dedifferentiation of the epidermis. Induction of Sp9 expression is nerve-dependent, and we have identified KGF as an endogenous nerve factor that induces expression of Sp9 in the regeneration epithelium.

Transcriptome Analysis Provides a Preliminary Regulation Route of the Ethylene Signal Transduction Component, SlEIN2, during Tomato Ripening.

PubMed

Wang, Rui-Heng; Yuan, Xin-Yu; Meng, Lan-Huan; Zhu, Ben-Zhong; Zhu, Hong-Liang; Luo, Yun-Bo; Fu, Da-Qi

2016-01-01

Ethylene is crucial in climacteric fruit ripening. The ethylene signal pathway regulates several physiological alterations such as softening, carotenoid accumulation and sugar level reduction, and production of volatile compounds. All these physiological processes are controlled by numerous genes and their expression simultaneously changes at the onset of ripening. Ethylene insensitive 2 (EIN2) is a key component for ethylene signal transduction, and its mutation causes ethylene insensitivity. In tomato, silencing SlEIN2 resulted in a non-ripening phenotype and low ethylene production. RNA sequencing of SlEIN2-silenced and wild type tomato, and differential gene expression analyses, indicated that silencing SlEIN2 caused changes in more than 4,000 genes, including those related to photosynthesis, defense, and secondary metabolism. The relative expression level of 28 genes covering ripening-associated transcription factors, ethylene biosynthesis, ethylene signal pathway, chlorophyll binding proteins, lycopene and aroma biosynthesis, and defense pathway, showed that SlEIN2 influences ripening inhibitor (RIN) in a feedback loop, thus controlling the expression of several other genes. SlEIN2 regulates many aspects of fruit ripening, and is a key factor in the ethylene signal transduction pathway. Silencing SlEIN2 ultimately results in lycopene biosynthesis inhibition, which is the reason why tomato does not turn red, and this gene also affects the expression of several defense-associated genes. Although SlEIN2-silenced and green wild type fruits are similar in appearance, their metabolism is significantly different at the molecular level.

Notch/Delta signaling constrains reengineering of pro-T cells by PU.1

PubMed Central

Franco, Christopher B.; Scripture-Adams, Deirdre D.; Proekt, Irina; Taghon, Tom; Weiss, Angela H.; Yui, Mary A.; Adams, Stephanie L.; Diamond, Rochelle A.; Rothenberg, Ellen V.

2006-01-01

PU.1 is essential for early stages of mouse T cell development but antagonizes it if expressed constitutively. Two separable mechanisms are involved: attenuation and diversion. Dysregulated PU.1 expression inhibits pro-T cell survival, proliferation, and passage through β-selection by blocking essential T cell transcription factors, signaling molecules, and Rag gene expression, which expression of a rearranged T cell antigen receptor transgene cannot rescue. However, Bcl2 transgenic cells are protected from this attenuation and may even undergo β-selection, as shown by PU.1 transduction of defined subsets of Bcl2 transgenic fetal thymocytes with differentiation in OP9-DL1 and OP9 control cultures. The outcome of PU.1 expression in these cells depends on Notch/Delta signaling. PU.1 can efficiently divert thymocytes toward a myeloid-like state with multigene regulatory changes, but Notch/Delta signaling vetoes diversion. Gene expression analysis distinguishes sets of critical T lineage regulatory genes with different combinatorial responses to PU.1 and Notch/Delta signals, suggesting particular importance for inhibition of E proteins, Myb, and/or Gfi1 (growth factor independence 1) in diversion. However, Notch signaling only protects against diversion of cells that have undergone T lineage specification after Thy-1 and CD25 up-regulation. The results imply that in T cell precursors, Notch/Delta signaling normally acts to modulate and channel PU.1 transcriptional activities during the stages from T lineage specification until commitment. PMID:16880393

Preface: cardiac control pathways: signaling and transport phenomena.

PubMed

Sideman, Samuel

2008-03-01

Signaling is part of a complex system of communication that governs basic cellular functions and coordinates cellular activity. Transfer of ions and signaling molecules and their interactions with appropriate receptors, transmembrane transport, and the consequent intracellular interactions and functional cellular response represent a complex system of interwoven phenomena of transport, signaling, conformational changes, chemical activation, and/or genetic expression. The well-being of the cell thus depends on a harmonic orchestration of all these events and the existence of control mechanisms that assure the normal behavior of the various parameters involved and their orderly expression. The ability of cells to sustain life by perceiving and responding correctly to their microenvironment is the basis for development, tissue repair, and immunity, as well as normal tissue homeostasis. Natural deviations, or human-induced interference in the signaling pathways and/or inter- and intracellular transport and information transfer, are responsible for the generation, modulation, and control of diseases. The present overview aims to highlight some major topics of the highly complex cellular information transfer processes and their control mechanisms. Our goal is to contribute to the understanding of the normal and pathophysiological phenomena associated with cardiac functions so that more efficient therapeutic modalities can be developed. Our objective in this volume is to identify and enhance the study of some basic passive and active physical and chemical transport phenomena, physiological signaling pathways, and their biological consequences.

Rab11-FIP3 Regulation of Lck Endosomal Traffic Controls TCR Signal Transduction.

PubMed

Bouchet, Jérôme; Del Río-Iñiguez, Iratxe; Vázquez-Chávez, Elena; Lasserre, Rémi; Agüera-González, Sonia; Cuche, Céline; McCaffrey, Mary W; Di Bartolo, Vincenzo; Alcover, Andrés

2017-04-01

The role of endosomes in receptor signal transduction is a long-standing question, which remains largely unanswered. The T cell Ag receptor and various components of its proximal signaling machinery are associated with distinct endosomal compartments, but how endosomal traffic affects T cell signaling remains ill-defined. In this article, we demonstrate in human T cells that the subcellular localization and function of the protein tyrosine kinase Lck depends on the Rab11 effector FIP3 (Rab11 family interacting protein-3). FIP3 overexpression or silencing and its ability to interact with Rab11 modify Lck subcellular localization and its delivery to the immunological synapse. Importantly, FIP3-dependent Lck localization controls early TCR signaling events, such as tyrosine phosphorylation of TCRζ, ZAP70, and LAT and intracellular calcium concentration, as well as IL-2 gene expression. Interestingly, FIP3 controls both steady-state and poststimulation phosphotyrosine and calcium levels. Finally, our findings indicate that FIP3 modulates TCR-CD3 cell surface expression via the regulation of steady-state Lck-mediated TCRζ phosphorylation, which in turn controls TCRζ protein levels. This may influence long-term T cell activation in response to TCR-CD3 stimulation. Therefore, our data underscore the importance of finely regulated endosomal traffic in TCR signal transduction and T cell activation leading to IL-2 production. Copyright © 2017 by The American Association of Immunologists, Inc.

Hepatocyte growth factor (HGF) upregulates heparanase expression via the PI3K/Akt/NF-κB signaling pathway for gastric cancer metastasis.

PubMed

Hao, Ning-Bo; Tang, Bo; Wang, Guo-Zheng; Xie, Rui; Hu, Chang-Jiang; Wang, Su-Min; Wu, Yu-Yun; Liu, En; Xie, Xia; Yang, Shi-Ming

2015-05-28

Heparanase (HPA) is an endoglucuronidase that can promote the shedding of associated cytokines in several types of tumors. However, little is known about what controls the expression of HPA or its role in gastric cancer. In this study, we report for the first time that HGF regulates HPA expression to promote gastric cancer metastasis. In this study, HGF and HPA were found to be significantly expressed in 58 gastric cancer patients. High expression of both HGF and HPA was positively associated with TNM stage, invasion depth and poor prognosis. In MKN74 cells, exogenous HGF significantly increased HPA expression at both the mRNA and protein levels. Further study revealed that HGF first activated PI3K/Akt signaling. NF-κB signaling was activated downstream of PI3K/Akt and promoted HPA expression. However, when c-met, PI3K/Akt or NF-κB signal inhibitors were used, HPA expression was significantly decreased. All of these results indicate that HGF regulates HPA expression by PI3K/Akt and downstream NF-κB signaling. Using bioinformatics and the ChIP assay, p65 was observed to bind to the HPA promoter. Furthermore, HGF significantly induced tumor cell migration, whereas treatment with an NF-κB inhibitor decreased migration. Moreover, when HPA was overexpressed in MKN74 cells, migration was significantly enhanced, and the HGF concentration was increased. However, when HPA was down-regulated in MKN45 cells, migration and HGF levels decreased. Together, these results demonstrate that HGF/c-met can activate PI3K/Akt and downstream NF-κB signaling to promote HPA expression and subsequent tumor metastasis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Heterologous expression of bovine lactoferricin in Pichia methanolica.

PubMed

Wang, Haikuan; Zhao, Xinhuai; Lu, Fuping

2007-06-01

According to the bias of codon utilization of Pichia methanolica, a fragment encoding bovine lactoferricin has been cloned and expressed in the P. methanolica under the control of the alcohol oxidase promoter, which was followed by the Saccharomyces cerevisiae alpha-factor signal peptide. The alpha-factor signal peptide efficiently directed the secretion of bovine lactoferricin from the recombinant yeast cell. The recombinant bovine lactoferricin appears to be successfully expressed, as it displays antibacterial activity (antibacterial assay). Moreover, the identity of the recombinant product was estimated by Tricine-SDS-PAGE.

A Bmp/Admp regulatory circuit controls maintenance and regeneration of dorsal-ventral polarity in planarians.

PubMed

Gaviño, Michael A; Reddien, Peter W

2011-02-22

Animal embryos have diverse anatomy and vary greatly in size. It is therefore remarkable that a common signaling pathway, BMP signaling, controls development of the dorsoventral (DV) axis throughout the Bilateria. In vertebrates, spatially opposed expression of the BMP family proteins Bmp4 and Admp (antidorsalizing morphogenetic protein) can promote restoration of DV pattern following tissue removal. bmp4 orthologs have been identified in all three groups of the Bilateria (deuterostomes, ecdysozoans, and lophotrochozoans). By contrast, the absence of admp orthologs in ecdysozoans such as Drosophila and C. elegans has suggested that a regulatory circuit of oppositely expressed bmp4 and admp genes represents a deuterostome-specific innovation. Here we describe the existence of spatially opposed bmp and admp expression in a protostome. An admp ortholog (Smed-admp) is expressed ventrally and laterally in adult Schmidtea mediterranea planarians, opposing the dorsal-pole expression of Smed-bmp4. Smed-admp is required for regeneration following parasagittal amputation. Furthermore, Smed-admp promotes Smed-bmp4 expression and Smed-bmp4 inhibits Smed-admp expression, generating a regulatory circuit that buffers against perturbations of Bmp signaling. These results suggest that a Bmp/Admp regulatory circuit is a central feature of the Bilateria, used broadly for the establishment, maintenance, and regeneration of the DV axis. Copyright © 2011 Elsevier Ltd. All rights reserved.

Myostatin: a novel insight into its role in metabolism, signal pathways, and expression regulation.

PubMed

Huang, Zhiqing; Chen, Xiaoling; Chen, Daiwen

2011-09-01

Myostatin, a member of the transforming growth factor-β (TGF-β) superfamily, is a critical autocrine/paracrine inhibitor of skeletal muscle growth. Since the first observed double-muscling phenotype was reported in myostatin-null animals, a functional role of myostatin has been demonstrated in the control of skeletal muscle development. However, beyond the confines of its traditional role in muscle growth inhibition, myostatin has recently been shown to play an important role in metabolism. During the past several years, it has been well established that Smads are canonical mediators of signals for myostatin from the receptors to the nucleus. However, growing evidence supports the notion that Non-Smad signal pathways also participate in myostatin signaling. Myostatin expression is increased in muscle atrophy and metabolic disorders, suggesting that changes in endogenous expression of myostatin may provide therapeutic benefit for these diseases. MicroRNAs (miRNAs) are a class of non-coding RNAs that negatively regulate gene expression and recent evidence has accumulated supporting a role for miRNAs in the regulation of myostatin expression. This review highlights some of these areas in myostatin research: a novel role in metabolism, signal pathways, and miRNA-mediated expression regulation. Copyright © 2011 Elsevier Inc. All rights reserved.

mAKAP – A Master Scaffold for Cardiac Remodeling

PubMed Central

Passariello, Catherine L.; Li, Jinliang; Dodge-Kafka, Kimberly; Kapiloff, Michael S.

2014-01-01

Cardiac remodeling is regulated by an extensive intracellular signal transduction network. Each of the many signaling pathways in this network contributes uniquely to the control of cellular adaptation. In the last few years, it has become apparent that multimolecular signaling complexes or ‘signalosomes’ are important for fidelity in intracellular signaling and for mediating crosstalk between the different signaling pathways. These complexes integrate upstream signals and control downstream effectors. In the cardiac myocyte, the protein mAKAPβ serves as a scaffold for a large signalosome that is responsive to cAMP, calcium, hypoxia, and mitogen-activated protein kinase signaling. The main function of mAKAPβ signalosomes is to modulate stress-related gene expression regulated by the transcription factors NFATc, MEF2 and HIF-1α and type II histone deacetylases that control pathological cardiac hypertrophy. PMID:25551320

Systematical analysis of cutaneous squamous cell carcinoma network of microRNAs, transcription factors, and target and host genes.

PubMed

Wang, Ning; Xu, Zhi-Wen; Wang, Kun-Hao

2014-01-01

MicroRNAs (miRNAs) are small non-coding RNA molecules found in multicellular eukaryotes which are implicated in development of cancer, including cutaneous squamous cell carcinoma (cSCC). Expression is controlled by transcription factors (TFs) that bind to specific DNA sequences, thereby controlling the flow (or transcription) of genetic information from DNA to messenger RNA. Interactions result in biological signal control networks. Molecular components involved in cSCC were here assembled at abnormally expressed, related and global levels. Networks at these three levels were constructed with corresponding biological factors in term of interactions between miRNAs and target genes, TFs and miRNAs, and host genes and miRNAs. Up/down regulation or mutation of the factors were considered in the context of the regulation and significant patterns were extracted. Participants of the networks were evaluated based on their expression and regulation of other factors. Sub-networks with two core TFs, TP53 and EIF2C2, as the centers are identified. These share self-adapt feedback regulation in which a mutual restraint exists. Up or down regulation of certain genes and miRNAs are discussed. Some, for example the expression of MMP13, were in line with expectation while others, including FGFR3, need further investigation of their unexpected behavior. The present research suggests that dozens of components, miRNAs, TFs, target genes and host genes included, unite as networks through their regulation to function systematically in human cSCC. Networks built under the currently available sources provide critical signal controlling pathways and frequent patterns. Inappropriate controlling signal flow from abnormal expression of key TFs may push the system into an incontrollable situation and therefore contributes to cSCC development.

Maternal protein restriction in the rat inhibits placental insulin, mTOR, and STAT3 signaling and down-regulates placental amino acid transporters.

PubMed

Rosario, Fredrick J; Jansson, Nina; Kanai, Yoshikatsu; Prasad, Puttur D; Powell, Theresa L; Jansson, Thomas

2011-03-01

The mechanisms underlying reduced fetal growth in response to maternal protein restriction are not well established. Maternal levels of insulin, IGF-I, and leptin are decreased in rats fed a low protein (LP) diet. Because these hormones stimulate placental amino acid transporters in vitro, we hypothesized that maternal protein restriction inhibits placental leptin, insulin/IGF-I, and mammalian target of rapamycin signaling and down-regulates the expression and activity of placental amino acid transporters. Pregnant rats were fed either an isocaloric low protein (LP, 4% protein) or control diet (18% protein) and studied at gestational day (GD)15, GD19, or GD21 (term 23). At GD19 and GD21, placental expression of phosphorylated eukaryotic initiation factor 4E binding protein 1 (Thr-36/46 or Thr-70) and phosphorylated S6 ribosomal protein (Ser-235/236) was decreased in the LP group. In addition, placental expression of phosphorylated S6 kinase 1 (Thr-389), phosphorylated Akt (Thr-308), and phosphorylated signal transducer and activator of transcription 3 (Tyr-705) was reduced at GD21. In microvillous plasma membranes (MVM) isolated from placentas of LP animals, protein expression of the sodium-coupled neutral amino acid transporter (SNAT)2 and the large neutral amino acid transporters 1 and 2 was reduced at GD19 and GD21. MVM SNAT1 protein expression was reduced at GD21 in LP rats. SNAT4 and 4F2 heavy chain expression in MVM was unaltered. System A and L amino acid transporter activity was decreased in MVM from LP animals at GD19 and GD21. In conclusion, maternal protein restriction inhibits placental insulin, mammalian target of rapamycin signaling, and signal transducer and activator of transcription 3 signaling, which is associated with a down-regulation of placental amino acid transporters. We speculate that maternal endocrine and metabolic control of placental nutrient transport reduces fetal growth in response to protein restriction.

Hypothalamic growth hormone receptor (GHR) controls hepatic glucose production in nutrient-sensing leptin receptor (LepRb) expressing neurons.

PubMed

Cady, Gillian; Landeryou, Taylor; Garratt, Michael; Kopchick, John J; Qi, Nathan; Garcia-Galiano, David; Elias, Carol F; Myers, Martin G; Miller, Richard A; Sandoval, Darleen A; Sadagurski, Marianna

2017-05-01

The GH/IGF-1 axis has important roles in growth and metabolism. GH and GH receptor (GHR) are active in the central nervous system (CNS) and are crucial in regulating several aspects of metabolism. In the hypothalamus, there is a high abundance of GH-responsive cells, but the role of GH signaling in hypothalamic neurons is unknown. Previous work has demonstrated that the Ghr gene is highly expressed in LepRb neurons. Given that leptin is a key regulator of energy balance by acting on leptin receptor (LepRb)-expressing neurons, we tested the hypothesis that LepRb neurons represent an important site for GHR signaling to control body homeostasis. To determine the importance of GHR signaling in LepRb neurons, we utilized Cre/loxP technology to ablate GHR expression in LepRb neurons (Lepr EYFPΔGHR ). The mice were generated by crossing the Lepr cre on the cre-inducible ROSA26-EYFP mice to GHR L/L mice. Parameters of body composition and glucose homeostasis were evaluated. Our results demonstrate that the sites with GHR and LepRb co-expression include ARH, DMH, and LHA neurons. Leptin action was not altered in Lepr EYFPΔGHR mice; however, GH-induced pStat5-IR in LepRb neurons was significantly reduced in these mice. Serum IGF-1 and GH levels were unaltered, and we found no evidence that GHR signaling regulates food intake and body weight in LepRb neurons. In contrast, diminished GHR signaling in LepRb neurons impaired hepatic insulin sensitivity and peripheral lipid metabolism. This was paralleled with a failure to suppress expression of the gluconeogenic genes and impaired hepatic insulin signaling in Lepr EYFPΔGHR mice. These findings suggest the existence of GHR-leptin neurocircuitry that plays an important role in the GHR-mediated regulation of glucose metabolism irrespective of feeding.

The expression of the Slit-Robo signal in the retina of diabetic rats and the vitreous or fibrovascular retinal membranes of patients with proliferative diabetic retinopathy.

PubMed

Zhou, Weiyan; Wang, Hongya; Yu, Wenzhen; Xie, Wankun; Zhao, Min; Huang, Lvzhen; Li, Xiaoxin

2017-01-01

The Slit-Robo signal has an important role in vasculogenesis and angiogenesis. Our study examined the expression of Slit2 and its receptor, Robo1, in a rat model of streptozotocin-induced diabetes and in patients with proliferative diabetic retinopathy. Diabetes was induced in male Sprague-Dawley rats via a single, intraperitoneal injection of streptozotocin. The rats were sacrificed 1, 3 or 6 months after the injection. The expression of Slit2 and Robo1 in retinal tissue was measured by real-time reverse transcription polymerase chain reaction (RT-PCR), and protein levels were measured by western blotting and immunohistochemistry. Recombinant N-Slit2 protein was used to study the effects of Slit2 on the expression of VEGF in vivo. The concentration of Slit2 protein in human eyes was measured by enzyme-linked immunosorbent assay in 27 eyes with proliferative diabetic retinopathy and 28 eyes in control group. The expression of Slit2, Robo1 and VEGF in the excised human fibrovascular membranes was examined by fluorescence immunostaining and semi-quantitative RT-PCR. The expression of Slit2 and Robo1 in the retina was altered after STZ injection. Recombinant N-Slit2 protein did not increase the retinal VEGF expression. Vitreous concentrations of Slit2 were significantly higher in the study group than in the control group. In the human fibrovascular membranes of the study group, the co-localization of VEGF with the markers for Slit2 and Robo1was observed. The expression of Slit2 mRNA, Robo1 mRNA, and VEGF mRNA was significantly higher in human fibrovascular proliferative diabetic retinopathy membranes than in the control membranes. The alteration of Slit2 and Robo1 expression in the retinas of diabetic rats and patients with proliferative diabetic retinopathy suggests a role for the Slit-Robo signal in the various stages diabetic retinopathy. Further studies should address the possible involvement of the Slit-Robo signal in the pathophysiological progress of diabetic retinopathy.

Cashmere growth control in Liaoning cashmere goat by ovarian carcinoma immunoreactive antigen-like protein 2 and decorin genes

PubMed Central

2018-01-01

Objective The study investigated the biological functions and mechanisms for controlling cashmere growth of Liaoning cashmere goat by ovarian carcinoma immunoreactive antigen-like protein 2 (OCIAD2) and decorin (DCN) genes. Methods cDNA library of Liaoning cashmere goat was constructed in early stages. OCIAD2 and DCN genes related to cashmere growth were identified by homology analysis comparison. The expression location of OCIAD2 and DCN genes in primary and secondary hair follicles (SF) was performed using in situ hybridization. The expression of OCIAD2 and DCN genes in primary and SF was performed using real-time polymerase chain reaction (PCR). Results In situ hybridization revealed that OCIAD2 and DCN were expressed in the inner root sheath of Liaoning cashmere goat hair follicles. Real-time quantitative PCR showed that these genes were highly expressed in SF during anagen, while these genes were highly expressed in primary hair follicle in catagen phase. Melatonin (MT) inhibited the expression of OCIAD2 and promoted the expression of DCN. Insulin-like growth factors-1 (IGF-1) inhibited the expression of OCIAD2 and DCN, while fibroblast growth factors 5 (FGF5) promoted the expression of these genes. MT and IGF-1 promoted OCIAD2 synergistically, while MT and FGF5 inhibited the genes simultaneously. MT+IGF-1/MT+FGF5 inhibited DCN gene. RNAi technology showed that OCIAD2 expression was promoted, while that of DCN was inhibited. Conclusion Activation of bone morphogenetic protein (BMP) signaling pathway up-regulated OCIAD2 expression and stimulated SF to control cell proliferation. DCN gene affected hair follicle morphogenesis and periodic changes by promoting transforming growth factor-β (TGF-β) and BMP signaling pathways. OCIAD2 and DCN genes have opposite effects on TGF-β signaling pathway and inhibit each other to affect the hair growth. PMID:29514440

Protein Kinase Cι Drives a NOTCH3-dependent Stem-like Phenotype in Mutant KRAS Lung Adenocarcinoma.

PubMed

Ali, Syed A; Justilien, Verline; Jamieson, Lee; Murray, Nicole R; Fields, Alan P

2016-03-14

We report that the protein kinase Cι (PKCι) oncogene controls expression of NOTCH3, a key driver of stemness, in KRAS-mediated lung adenocarcinoma (LADC). PKCι activates NOTCH3 expression by phosphorylating the ELF3 transcription factor and driving ELF3 occupancy on the NOTCH3 promoter. PKCι-ELF3-NOTCH3 signaling controls the tumor-initiating cell phenotype by regulating asymmetric cell division, a process necessary for tumor initiation and maintenance. Primary LADC tumors exhibit PKCι-ELF3-NOTCH3 signaling, and combined pharmacologic blockade of PKCι and NOTCH synergistically inhibits tumorigenic behavior in vitro and LADC growth in vivo demonstrating the therapeutic potential of PKCι-ELF3-NOTCH3 signal inhibition to more effectively treat KRAS LADC. Copyright © 2016 Elsevier Inc. All rights reserved.

Signal transduction in the carnivorous plant Sarracenia purpurea. Regulation of secretory hydrolase expression during development and in response to resources.

PubMed Central

Gallie, D R; Chang, S C

1997-01-01

Carnivory in plants has developed as an evolutionary adaptation to nutrient-poor environments. A significant investment of the resources of a carnivorous plant is committed to producing the traps, attractants, and digestive enzymes needed for the carnivory. The cost:benefit ratio of carnivory can be improved by either maximizing the prey capture rate or by reducing the metabolic commitment toward carnivory. Using the pitcher plant Sarracenia purpurea, we have investigated whether the expression of the hydrolytic enzymes needed for digestion is regulated in response to the presence of prey. Expression of protease, RNase, nuclease, and phosphatase activities could be induced in the fluid of nonactive traps by the addition of nucleic acids, protein, or reduced nitrogen, suggesting that hydrolase expression is induced upon perception of the appropriate chemical signal. Hydrolase expression was also developmentally controlled since expression commenced upon opening of a trap, increased for several days, and in the absence of prey largely ceased within 2 weeks. Nevertheless, the traps remained competent to induce expression in response to the appropriate signals. These data suggest that in young traps hydrolase expression is developmentally regulated, which is later replaced by a signal transduction mechanism, and they demonstrate the ability of a carnivorous species to respond to the availability of resources. PMID:9414556

Signal transduction in the carnivorous plant Sarracenia purpurea. Regulation of secretory hydrolase expression during development and in response to resources.

PubMed

Gallie, D R; Chang, S C

1997-12-01

Carnivory in plants has developed as an evolutionary adaptation to nutrient-poor environments. A significant investment of the resources of a carnivorous plant is committed to producing the traps, attractants, and digestive enzymes needed for the carnivory. The cost:benefit ratio of carnivory can be improved by either maximizing the prey capture rate or by reducing the metabolic commitment toward carnivory. Using the pitcher plant Sarracenia purpurea, we have investigated whether the expression of the hydrolytic enzymes needed for digestion is regulated in response to the presence of prey. Expression of protease, RNase, nuclease, and phosphatase activities could be induced in the fluid of nonactive traps by the addition of nucleic acids, protein, or reduced nitrogen, suggesting that hydrolase expression is induced upon perception of the appropriate chemical signal. Hydrolase expression was also developmentally controlled since expression commenced upon opening of a trap, increased for several days, and in the absence of prey largely ceased within 2 weeks. Nevertheless, the traps remained competent to induce expression in response to the appropriate signals. These data suggest that in young traps hydrolase expression is developmentally regulated, which is later replaced by a signal transduction mechanism, and they demonstrate the ability of a carnivorous species to respond to the availability of resources.

Social Alienation in Schizophrenia Patients: Association with Insula Responsiveness to Facial Expressions of Disgust

PubMed Central

Lindner, Christian; Dannlowski, Udo; Walhöfer, Kirsten; Rödiger, Maike; Maisch, Birgit; Bauer, Jochen; Ohrmann, Patricia; Lencer, Rebekka; Zwitserlood, Pienie; Kersting, Anette; Heindel, Walter; Arolt, Volker

2014-01-01

Introduction Among the functional neuroimaging studies on emotional face processing in schizophrenia, few have used paradigms with facial expressions of disgust. In this study, we investigated whether schizophrenia patients show less insula activation to macro-expressions (overt, clearly visible expressions) and micro-expressions (covert, very brief expressions) of disgust than healthy controls. Furthermore, departing from the assumption that disgust faces signal social rejection, we examined whether perceptual sensitivity to disgust is related to social alienation in patients and controls. We hypothesized that high insula responsiveness to facial disgust predicts social alienation. Methods We used functional magnetic resonance imaging to measure insula activation in 36 schizophrenia patients and 40 healthy controls. During scanning, subjects passively viewed covert and overt presentations of disgust and neutral faces. To measure social alienation, a social loneliness scale and an agreeableness scale were administered. Results Schizophrenia patients exhibited reduced insula activation in response to covert facial expressions of disgust. With respect to macro-expressions of disgust, no between-group differences emerged. In patients, insula responsiveness to covert faces of disgust was positively correlated with social loneliness. Furthermore, patients' insula responsiveness to covert and overt faces of disgust was negatively correlated with agreeableness. In controls, insula responsiveness to covert expressions of disgust correlated negatively with agreeableness. Discussion Schizophrenia patients show reduced insula responsiveness to micro-expressions but not macro-expressions of disgust compared to healthy controls. In patients, low agreeableness was associated with stronger insula response to micro- and macro-expressions of disgust. Patients with a strong tendency to feel uncomfortable with social interactions appear to be characterized by a high sensitivity for facial expression signaling social rejection. Given the associations of insula responsiveness to covert disgust expression with low agreeableness in healthy individuals, insula responsiveness to expressions of disgust might be in general a neural marker of the personality trait of agreeableness. PMID:24465469

Social alienation in schizophrenia patients: association with insula responsiveness to facial expressions of disgust.

PubMed

Lindner, Christian; Dannlowski, Udo; Walhöfer, Kirsten; Rödiger, Maike; Maisch, Birgit; Bauer, Jochen; Ohrmann, Patricia; Lencer, Rebekka; Zwitserlood, Pienie; Kersting, Anette; Heindel, Walter; Arolt, Volker; Kugel, Harald; Suslow, Thomas

2014-01-01

Among the functional neuroimaging studies on emotional face processing in schizophrenia, few have used paradigms with facial expressions of disgust. In this study, we investigated whether schizophrenia patients show less insula activation to macro-expressions (overt, clearly visible expressions) and micro-expressions (covert, very brief expressions) of disgust than healthy controls. Furthermore, departing from the assumption that disgust faces signal social rejection, we examined whether perceptual sensitivity to disgust is related to social alienation in patients and controls. We hypothesized that high insula responsiveness to facial disgust predicts social alienation. We used functional magnetic resonance imaging to measure insula activation in 36 schizophrenia patients and 40 healthy controls. During scanning, subjects passively viewed covert and overt presentations of disgust and neutral faces. To measure social alienation, a social loneliness scale and an agreeableness scale were administered. Schizophrenia patients exhibited reduced insula activation in response to covert facial expressions of disgust. With respect to macro-expressions of disgust, no between-group differences emerged. In patients, insula responsiveness to covert faces of disgust was positively correlated with social loneliness. Furthermore, patients' insula responsiveness to covert and overt faces of disgust was negatively correlated with agreeableness. In controls, insula responsiveness to covert expressions of disgust correlated negatively with agreeableness. Schizophrenia patients show reduced insula responsiveness to micro-expressions but not macro-expressions of disgust compared to healthy controls. In patients, low agreeableness was associated with stronger insula response to micro- and macro-expressions of disgust. Patients with a strong tendency to feel uncomfortable with social interactions appear to be characterized by a high sensitivity for facial expression signaling social rejection. Given the associations of insula responsiveness to covert disgust expression with low agreeableness in healthy individuals, insula responsiveness to expressions of disgust might be in general a neural marker of the personality trait of agreeableness.

Secreted expression of Leuconostoc mesenteroides glucansucrase in Lactococcus lactis for the production of insoluble glucans

USDA-ARS?s Scientific Manuscript database

We expressed a glucansucrase, DsrI, from Leuconostoc mesenteroides that catalyzes formation of water-insoluble glucans from sucrose in Lactococcus lactis using a nisin-controlled gene expression system. Production of DsrI was optimized using several different background vectors, signal peptides, str...

Repression of Ccr9 transcription in mouse T lymphocyte progenitors by the Notch signaling pathway.

PubMed

Krishnamoorthy, Veena; Carr, Tiffany; de Pooter, Renee F; Emanuelle, Akinola Olumide; Akinola, Emanuelle Olumide; Gounari, Fotini; Kee, Barbara L

2015-04-01

The chemokine receptor CCR9 controls the immigration of multipotent hematopoietic progenitor cells into the thymus to sustain T cell development. Postimmigration, thymocytes downregulate CCR9 and migrate toward the subcapsular zone where they recombine their TCR β-chain and γ-chain gene loci. CCR9 is subsequently upregulated and participates in the localization of thymocytes during their selection for self-tolerant receptor specificities. Although the dynamic regulation of CCR9 is essential for early T cell development, the mechanisms controlling CCR9 expression have not been determined. In this article, we show that key regulators of T cell development, Notch1 and the E protein transcription factors E2A and HEB, coordinately control the expression of Ccr9. E2A and HEB bind at two putative enhancers upstream of Ccr9 and positively regulate CCR9 expression at multiple stages of T cell development. In contrast, the canonical Notch signaling pathway prevents the recruitment of p300 to the putative Ccr9 enhancers, resulting in decreased acetylation of histone H3 and a failure to recruit RNA polymerase II to the Ccr9 promoter. Although Notch signaling modestly modulates the binding of E proteins to one of the two Ccr9 enhancers, we found that Notch signaling represses Ccr9 in T cell lymphoma lines in which Ccr9 transcription is independent of E protein function. Our data support the hypothesis that activation of Notch1 has a dominant-negative effect on Ccr9 transcription and that Notch1 and E proteins control the dynamic expression of Ccr9 during T cell development. Copyright © 2015 by The American Association of Immunologists, Inc.

Resistin increases the expression of NOD2 in mouse monocytes.

PubMed

Ren, Yi; Wan, Taomei; Zuo, Zhicai; Cui, Hengmin; Peng, Xi; Fang, Jing; Deng, Junliang; Hu, Yanchun; Yu, Shuming; Shen, Liuhong; Ma, Xiaoping; Wang, Ya; Ren, Zhihua

2017-05-01

Previous studies have indicated that resistin, a type of adipokine, contributes to the development of insulin resistance and type 2 diabetes mellitus, and mediates inflammatory reactions. However, a specific receptor for resistin has not yet been identified. In this study, the relationship between resistin and nucleotide-binding oligomerization domain-like receptors, as well as resistin signal transduction, was examined through transfection, quantitative polymerase chain reaction, western blot analysis and ELISA. The mRNA expression of nucleotide-binding oligomerization domain-containing protein 2 (NOD2), a key immune receptor related to insulin resistance, was significantly increased by resistin treatment at concentrations of 100, 150 and 200 ng/ml (P<0.05, P<0.01 and P<0.01, respectively). The mRNA expression of downstream signaling molecules in the NOD2 signaling pathway, receptor-interacting serine/threonine-protein kinase 2 (RIP2; P<0.01 at 6, 12 and 24 h) and inhibitor of NF-κB kinase subunit beta (P<0.01 at 3, 6, 12 and 24 h) were significantly increased by resistin treatment compared with the control. The mRNA expression of key proinflammatory cytokines, tumor necrosis factor α, IL (interleukin)-6 and IL-1β, were also significantly increased by resistin treatment compared with the control (P<0.01). NOD2 knockdown by small interfering RNA (siRNA) significantly decreased the expression of NOD2 and RIP2 (P<0.01), and there was no significant increase in the levels of cytokines, as compared with treatment with control siRNA. These findings indicate that the inflammatory reaction induced by resistin involves the NOD2-nuclear factor (NF)-κB signaling pathway. The inhibition of NF-κB significantly decreased the secretion of key inflammatory cytokines (P<0.01), suggesting that NF-κB signaling mechanisms are essential to the resistin-induced inflammatory response.

Deregulated expression of TANK in glioblastomas triggers pro-tumorigenic ERK1/2 and AKT signaling pathways.

PubMed

Stellzig, J; Chariot, A; Shostak, K; Ismail Göktuna, S; Renner, F; Acker, T; Pagenstecher, A; Schmitz, M L

2013-11-11

Signal transmission by the noncanonical IkappaB kinases (IKKs), TANK-binding kinase 1 (TBK1) and IKKɛ, requires interaction with adapter proteins such as TRAF associated NF-κB activator (TANK). Although increased expression or dysregulation of both kinases has been described for a variety of human cancers, this study shows that deregulated expression of the TANK protein is frequently occurring in glioblastomas (GBMs). The functional relevance of TANK was analyzed in a panel of GBM-derived cell lines and revealed that knockdown of TANK arrests cells in the S-phase and prohibits tumor cell migration. Deregulated TANK expression affects several signaling pathways controlling cell proliferation and the inflammatory response. Interference with stoichiometrically assembled signaling complexes by overexpression or silencing of TANK prevented constitutive interferon-regulatory factor 3 (IRF3) phosphorylation. Knockdown of TANK frequently prevents constitutive activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2). TANK-mediated ERK1/2 activation is independent from the canonical MAP kinase or ERK kinase (MEK) 1/2-mediated pathway and utilizes an alternative pathway that uses a TBK1/IKKɛ/Akt signaling axis, thus identifying a novel pathway suitable to block constitutive ERK1/2 activity.

OVOL2 antagonizes TGF-β signaling to regulate epithelial to mesenchymal transition during mammary tumor metastasis

PubMed Central

Wu, Di; Liu, Na; Liu, Qing-Feng; Wu, Qiu-Wan; Xie, Yuan-Yuan; Liu, Yun-Jia; Zheng, Zhong-Zheng; Chan, Err-Cheng; Zhang, Zhi-Ming; Li, Bo-An

2017-01-01

Great progress has been achieved in the study of the role of TGF-β signaling in triggering epithelial-mesenchymal transition (EMT) in a variety of cancers; however, the regulation of TGF-β signaling during EMT in mammary tumor metastasis has not been completely defined. In the present study, we demonstrated that OVOL2, a zinc finger transcription factor, inhibits TGF-β signaling-induced EMT in mouse and human mammary tumor cells, as well as in mouse tumor models. Data from the Oncomine databases indicated a strong negative relationship between OVOL2 expression and breast cancer progression. Moreover, our experiments revealed that OVOL2 inhibits TGF-β signaling at multiple levels, including inhibiting Smad4 mRNA expression and inducing Smad7 mRNA expression, blocking the binding between Smad4 and target DNA, and interfering with complex formation between Smad4 and Smad2/3. These findings reveal a novel mechanism that controls the TGF-β signaling output level in vitro and in vivo. The modulation of these molecular processes may represent a strategy for inhibiting breast cancer invasion by restoring OVOL2 expression. PMID:28455959

Deregulated expression of TANK in glioblastomas triggers pro-tumorigenic ERK1/2 and AKT signaling pathways

PubMed Central

Stellzig, J; Chariot, A; Shostak, K; Ismail Göktuna, S; Renner, F; Acker, T; Pagenstecher, A; Schmitz, M L

2013-01-01

Signal transmission by the noncanonical IkappaB kinases (IKKs), TANK-binding kinase 1 (TBK1) and IKKɛ, requires interaction with adapter proteins such as TRAF associated NF-κB activator (TANK). Although increased expression or dysregulation of both kinases has been described for a variety of human cancers, this study shows that deregulated expression of the TANK protein is frequently occurring in glioblastomas (GBMs). The functional relevance of TANK was analyzed in a panel of GBM-derived cell lines and revealed that knockdown of TANK arrests cells in the S-phase and prohibits tumor cell migration. Deregulated TANK expression affects several signaling pathways controlling cell proliferation and the inflammatory response. Interference with stoichiometrically assembled signaling complexes by overexpression or silencing of TANK prevented constitutive interferon-regulatory factor 3 (IRF3) phosphorylation. Knockdown of TANK frequently prevents constitutive activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2). TANK-mediated ERK1/2 activation is independent from the canonical MAP kinase or ERK kinase (MEK) 1/2-mediated pathway and utilizes an alternative pathway that uses a TBK1/IKKɛ/Akt signaling axis, thus identifying a novel pathway suitable to block constitutive ERK1/2 activity. PMID:24217713

Recognizing emotion in faces: developmental effects of child abuse and neglect.

PubMed

Pollak, Seth D; Cicchetti, Dante; Hornung, Katherine; Reed, Alex

2000-09-01

The contributions to the recognition of emotional signals of (a) experience and learning versus (b) internal predispositions are difficult to investigate because children are virtually always exposed to complex emotional experiences from birth. The recognition of emotion among physically abused and physically neglected preschoolers was assessed in order to examine the effects of atypical experience on emotional development. In Experiment 1, children matched a facial expression to an emotional situation. Neglected children had more difficulty discriminating emotional expressions than did control or physically abused children. Physically abused children displayed a response bias for angry facial expressions. In Experiment 2, children rated the similarity of facial expressions. Control children viewed discrete emotions as dissimilar, neglected children saw fewer distinctions between emotions, and physically abused children showed the most variance across emotions. These results suggest that to the extent that children's experience with the world varies, so too will their interpretation and understanding of emotional signals.

Correct Hox gene expression established independently of position in Caenorhabditis elegans.

PubMed

Cowing, D; Kenyon, C

1996-07-25

The Hox genes are expressed in a conserved sequence of spatial domains along the anteroposterior (A/P) body axes of many organisms. In Drosophila, position-specific signals located along the A/P axis establish the pattern of Hox gene expression. In the nematode Caenorhabditis elegans, it is not known how the pattern of Hox gene expression is established. C. elegans uses lineal control mechanisms and local cell interactions to specify early blastomere identities. However, many cells expressing the same Hox gene are unrelated by lineage, suggesting that, as in Drosophila, domains of Hox gene expression may be defined by cell-extrinsic A/P positional signals. To test this, we have investigated whether posterior mesodermal and ectodermal cells will express their normal posterior Hox gene when they are mispositioned in the anterior. Surprisingly, we find that correct Hox gene expression does not depend on cell position, but is highly correlated with cell lineage. Thus, although the most striking feature of Hox gene expression is its positional specificity, in C. elegans the pattern is achieved, at least in part, by a lineage-specific control system that operates without regard to A/P position.

zic-1 Expression in Planarian Neoblasts after Injury Controls Anterior Pole Regeneration

PubMed Central

Vásquez-Doorman, Constanza; Petersen, Christian P.

2014-01-01

Mechanisms that enable injury responses to prompt regenerative outgrowth are not well understood. Planarians can regenerate essentially any tissue removed by wounding, even after decapitation, due to robust regulation of adult pluripotent stem cells of the neoblast population. Formation of pole signaling centers involving Wnt inhibitors or Wnt ligands promotes head or tail regeneration, respectively, and this process requires the use of neoblasts early after injury. We used expression profiling of purified neoblasts to identify factors needed for anterior pole formation. Using this approach, we identified zic-1, a Zic-family transcription factor, as transcriptionally activated in a subpopulation of neoblasts near wound sites early in head regeneration. As head regeneration proceeds, the Wnt inhibitor notum becomes expressed in the newly forming anterior pole in zic-1-expressing cells descended from neoblasts. Inhibition of zic-1 by RNAi resulted in a failure to express notum at the anterior pole and to regenerate a head, but did not affect tail regeneration. Both injury and canonical Wnt signaling inhibition are required for zic-1 expression, and double-RNAi experiments suggest zic-1 inhibits Wnt signaling to allow head regeneration. Analysis of neoblast fate determinants revealed that zic-1 controls specification of notum-expressing cells from foxD-expressing neoblasts to form the anterior pole, which organizes subsequent outgrowth. Specialized differentiation programs may in general underlie injury-dependent formation of tissue organizing centers used for regenerative outgrowth. PMID:24992682

Expression of WNT5A in Idiopathic Pulmonary Fibrosis and Its Control by TGF-β and WNT7B in Human Lung Fibroblasts.

PubMed

Newman, Donna R; Sills, W Shane; Hanrahan, Katherine; Ziegler, Amanda; Tidd, Kathleen McGinnis; Cook, Elizabeth; Sannes, Philip L

2016-02-01

The wingless (Wnt) family of signaling ligands contributes significantly to lung development and is highly expressed in patients with usual interstitial pneumonia (UIP). We sought to define the cellular distribution of Wnt5A in the lung tissue of patients with idiopathic pulmonary fibrosis (IPF) and the signaling ligands that control its expression in human lung fibroblasts and IPF myofibroblasts. Tissue sections from 40 patients diagnosed with IPF or UIP were probed for the immunolocalization of Wnt5A. Further, isolated lung fibroblasts from normal or IPF human lungs, adenovirally transduced for the overexpression or silencing of Wnt7B or treated with TGF-β1 or its inhibitor, were analyzed for Wnt5A protein expression. Wnt5A was expressed in IPF lungs by airway and alveolar epithelium, smooth muscle cells, endothelium, and myofibroblasts of fibroblastic foci and throughout the interstitium. Forced overexpression of Wnt7B with or without TGF-β1 treatment significantly increased Wnt5A protein expression in normal human smooth muscle cells and fibroblasts but not in IPF myofibroblasts where Wnt5A was already highly expressed. The results demonstrate a wide distribution of Wnt5A expression in cells of the IPF lung and reveal that it is significantly increased by Wnt7B and TGF-β1, which, in combination, could represent key signaling pathways that modulate the pathogenesis of IPF. © 2016 The Histochemical Society.

Anterior Gradient 2 (AGR2) Induced Epidermal Growth Factor Receptor (EGFR) Signaling Is Essential for Murine Pancreatitis-Associated Tissue Regeneration

PubMed Central

Wodziak, Dariusz; Dong, Aiwen; Basin, Michael F.; Lowe, Anson W.

2016-01-01

A recently published study identified Anterior Gradient 2 (AGR2) as a regulator of EGFR signaling by promoting receptor presentation from the endoplasmic reticulum to the cell surface. AGR2 also promotes tissue regeneration in amphibians and fish. Whether AGR2-induced EGFR signaling is essential for tissue regeneration in higher vertebrates was evaluated using a well-characterized murine model for pancreatitis. The impact of AGR2 expression and EGFR signaling on tissue regeneration was evaluated using the caerulein-induced pancreatitis mouse model. EGFR signaling and cell proliferation were examined in the context of the AGR2-/- null mouse or with the EGFR-specific tyrosine kinase inhibitor, AG1478. In addition, the Hippo signaling coactivator YAP1 was evaluated in the context of AGR2 expression during pancreatitis. Pancreatitis-induced AGR2 expression enabled EGFR translocation to the plasma membrane, the initiation of cell signaling, and cell proliferation. EGFR signaling and tissue regeneration were partially inhibited by the tyrosine kinase inhibitor AG1478, but absent in the AGR2-/- null mouse. AG1478-treated and AGR2-/- null mice with pancreatitis died whereas all wild-type controls recovered. YAP1 activation was also dependent on pancreatitis-induced AGR2 expression. AGR2-induced EGFR signaling was essential for tissue regeneration and recovery from pancreatitis. The results establish tissue regeneration as a major function of AGR2-induced EGFR signaling in adult higher vertebrates. Enhanced AGR2 expression and EGFR signaling are also universally present in human pancreatic cancer, which support a linkage between tissue injury, regeneration, and cancer pathogenesis. PMID:27764193

PCA3 noncoding RNA is involved in the control of prostate-cancer cell survival and modulates androgen receptor signaling

PubMed Central

2012-01-01

Background PCA3 is a non-coding RNA (ncRNA) that is highly expressed in prostate cancer (PCa) cells, but its functional role is unknown. To investigate its putative function in PCa biology, we used gene expression knockdown by small interference RNA, and also analyzed its involvement in androgen receptor (AR) signaling. Methods LNCaP and PC3 cells were used as in vitro models for these functional assays, and three different siRNA sequences were specifically designed to target PCA3 exon 4. Transfected cells were analyzed by real-time qRT-PCR and cell growth, viability, and apoptosis assays. Associations between PCA3 and the androgen-receptor (AR) signaling pathway were investigated by treating LNCaP cells with 100 nM dihydrotestosterone (DHT) and with its antagonist (flutamide), and analyzing the expression of some AR-modulated genes (TMPRSS2, NDRG1, GREB1, PSA, AR, FGF8, CdK1, CdK2 and PMEPA1). PCA3 expression levels were investigated in different cell compartments by using differential centrifugation and qRT-PCR. Results LNCaP siPCA3-transfected cells significantly inhibited cell growth and viability, and increased the proportion of cells in the sub G0/G1 phase of the cell cycle and the percentage of pyknotic nuclei, compared to those transfected with scramble siRNA (siSCr)-transfected cells. DHT-treated LNCaP cells induced a significant upregulation of PCA3 expression, which was reversed by flutamide. In siPCA3/LNCaP-transfected cells, the expression of AR target genes was downregulated compared to siSCr-transfected cells. The siPCA3 transfection also counteracted DHT stimulatory effects on the AR signaling cascade, significantly downregulating expression of the AR target gene. Analysis of PCA3 expression in different cell compartments provided evidence that the main functional roles of PCA3 occur in the nuclei and microsomal cell fractions. Conclusions Our findings suggest that the ncRNA PCA3 is involved in the control of PCa cell survival, in part through modulating AR signaling, which may raise new possibilities of using PCA3 knockdown as an additional therapeutic strategy for PCa control. PMID:23130941

Prolactin gene expression in the pituitary of rats subjected to vaginocervical stimulation requires Erk-1/2 signaling.

PubMed

Reuquen, Patricia; Guajardo-Correa, Emanuel; Oróstica, María L; Curotto, Constanza; Parada-Bustamante, Alexis; Cardenas, Hugo; Orihuela, Pedro A

2017-12-01

Vaginocervical stimulation (VCS) induces twice-daily prolactin (PRL) surges resulting in pseudopregnancy in the rat. Furthermore, activation of the extracellular signal-regulated kinase-1/2 (Erk-1/2) is involved in the effect of estradiol (E 2 ) on the Prl gene expression in pituitary cells. Herein, we investigated whether Erk-1/2 signaling is involved in the control of Prl expression in the pituitary of VCS rats and whether VCS regulates the effect of E 2 on Erk-1/2 and Prl in the pituitary. Estrous rats were assigned as control or VCS groups and 0, 6, 12 or 24h later the levels and localization of phosphorylated Erk-1/2 (p-Erk-1/2) were analyzed in the pituitary. The effect of an Erk-1/2 inhibitor PD98059 on the Prl level in the pituitary of control or VCS rats was also analyzed. Other control or VCS rats were treated with E 2 and the level of p-Erk-1/2 and Prl were measured in the pituitary. In control rats, p-Erk-1/2 decreased at 6 and 12h and increased at 24h while Erk-1/2 was phosphorylated at all time points in VCS rats. p-Erk-1/2 was localized only in the anterior pituitary. PD98059 decreased Prl level in VCS, but not in control rats. Estradiol decreased Erk-1/2 phosphorylation although did not change Prl level in the pituitary of control or VCS rats. These findings show that prolonged activation of Erk-1/2 is necessary to induce Prl expression in the pituitary of VCS rats; however, VCS does not influence the role of E 2 on the activation of Erk-1/2 and Prl expression the pituitary. Copyright © 2017 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Molecular Analysis of Erection Regulatory Factors in Sickle Cell Disease-Associated Priapism in Human Penis

PubMed Central

Lagoda, Gwen; Sezen, Sena F.; Cabrini, Marcelo R.; Musicki, Biljana; Burnett, Arthur L.

2015-01-01

Purpose Priapism is a vasculopathy occurring in approximately 40% of patients with SCD. Mouse models have suggested that dysregulated NOS and RhoA/ROCK signaling as well as increased oxidative stress may contribute to mechanisms of SCD-associated priapism. We examined changes in protein expressions of NOS and ROCK signaling pathways and a source of oxidative stress, NADPH oxidase, in penile erectile tissue from patients with priapism histories, etiologically related and unrelated to SCD. Materials and Methods Human penile erectile tissue was obtained from patients with SCD-associated priapism (SCD, n=5) and priapism of other etiologies (non-SCD, n=6) during non-emergent penile prosthesis surgery for ED or priapism management and urethroplasty, and from control patients without priapism histories (Control, n=5) during penectomy for penile cancer. Samples were collected, immediately placed in cold buffer and then frozen in liquid nitrogen. Expressions of PDE5, eNOS, nNOS, iNOS, RhoA, ROCK1, ROCK2, p47phox, p67phox, gp91phox and β-actin were determined by Western blot analysis and NO amount was measured using the Griess reaction. Results In the SCD group, PDE5 (p<0.05), eNOS (p<0.01) and RhoA (p<0.01) expressions were significantly decreased while gp91phox (p<0.05) expression was significantly increased compared to Control group values. In the non-SCD group, eNOS (p<0.05), ROCK1 (p<0.05) and p47phox (p<0.05) expressions were significantly decreased compared to Control group values. Total NO levels were not significantly different across study groups. Conclusions The mechanisms of SCD-associated priapism in the human penis may involve dysfunctional NOS and ROCK signaling and increased oxidative stress associated with NADPH oxidase-mediated signaling. PMID:22982429

A method for studying the hunting oscillations of an airplane with a simple type of automatic control

NASA Technical Reports Server (NTRS)

Jones, Robert T

1944-01-01

A method is presented for predicting the amplitude and frequency, under certain simplifying conditions, of the hunting oscillations of an automatically controlled aircraft with lag in the control system or in the response of the aircraft to the controls. If the steering device is actuated by a simple right-left type of signal, the series of alternating fixed-amplified signals occurring during the hunting may ordinarily be represented by a "square wave." Formulas are given expressing the response to such a variations of signal in terms of the response to a unit signal. A more complex type of hunting, which may involve cyclic repetition of signals of varying duration, has not been treated and requires further analysis. Several examples of application of the method are included and the results discussed.

Slit/Robo1 signaling regulates neural tube development by balancing neuroepithelial cell proliferation and differentiation

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

Wang, Guang; Li, Yan; Wang, Xiao-yu

2013-05-01

Formation of the neural tube is the morphological hallmark for development of the embryonic central nervous system (CNS). Therefore, neural tube development is a crucial step in the neurulation process. Slit/Robo signaling was initially identified as a chemo-repellent that regulated axon growth cone elongation, but its role in controlling neural tube development is currently unknown. To address this issue, we investigated Slit/Robo1 signaling in the development of chick neCollege of Life Sciences Biocentre, University of Dundee, Dundee DD1 5EH, UKural tube and transgenic mice over-expressing Slit2. We disrupted Slit/Robo1 signaling by injecting R5 monoclonal antibodies into HH10 neural tubes tomore » block the Robo1 receptor. This inhibited the normal development of the ventral body curvature and caused the spinal cord to curl up into a S-shape. Next, Slit/Robo1 signaling on one half-side of the chick embryo neural tube was disturbed by electroporation in ovo. We found that the morphology of the neural tube was dramatically abnormal after we interfered with Slit/Robo1 signaling. Furthermore, we established that silencing Robo1 inhibited cell proliferation while over-expressing Robo1 enhanced cell proliferation. We also investigated the effects of altering Slit/Robo1 expression on Sonic Hedgehog (Shh) and Pax7 expression in the developing neural tube. We demonstrated that over-expressing Robo1 down-regulated Shh expression in the ventral neural tube and resulted in the production of fewer HNK-1{sup +} migrating neural crest cells (NCCs). In addition, Robo1 over-expression enhanced Pax7 expression in the dorsal neural tube and increased the number of Slug{sup +} pre-migratory NCCs. Conversely, silencing Robo1 expression resulted in an enhanced Shh expression and more HNK-1{sup +} migrating NCCs but reduced Pax7 expression and fewer Slug{sup +} pre-migratory NCCs were observed. In conclusion, we propose that Slit/Robo1 signaling is involved in regulating neural tube development by tightly coordinating cell proliferation and differentiation during neurulation. - Highlights: ► The role of Slit/Robo1 signaling was investigated with chick and mouse models. ► Disturbance of Slit/Robo1 signaling resulted in neural tube defects. ► Slit/Robo1 signaling regulated the proliferation of neural tube cells. ► Slit/Robo1 signaling modulated the differentiation of neural tube cells. ► Slit/Robo1 signaling balanced the proliferation and differentiation of neural tube.« less

Emotional expressions beyond facial muscle actions. A call for studying autonomic signals and their impact on social perception

PubMed Central

Kret, Mariska E.

2015-01-01

Humans are well adapted to quickly recognize and adequately respond to another’s emotions. Different theories propose that mimicry of emotional expressions (facial or otherwise) mechanistically underlies, or at least facilitates, these swift adaptive reactions. When people unconsciously mimic their interaction partner’s expressions of emotion, they come to feel reflections of those companions’ emotions, which in turn influence the observer’s own emotional and empathic behavior. The majority of research has focused on facial actions as expressions of emotion. However, the fact that emotions are not just expressed by facial muscles alone is often still ignored in emotion perception research. In this article, I therefore argue for a broader exploration of emotion signals from sources beyond the face muscles that are more automatic and difficult to control. Specifically, I will focus on the perception of implicit sources such as gaze and tears and autonomic responses such as pupil-dilation, eyeblinks and blushing that are subtle yet visible to observers and because they can hardly be controlled or regulated by the sender, provide important “veridical” information. Recently, more research is emerging about the mimicry of these subtle affective signals including pupil-mimicry. I will here review this literature and suggest avenues for future research that will eventually lead to a better comprehension of how these signals help in making social judgments and understand each other’s emotions. PMID:26074855

The Response of wnt/ ß-Catenin Signaling Pathway in Osteocytes Under Simulated Microgravity

NASA Astrophysics Data System (ADS)

Yang, Xiao; Sun, Lian-Wen; Liang, Meng; Wang, Xiao-Nan; Fan, Yu-Bo

2015-11-01

Osteocytes were considered as potential sensors of mechanical loading and orchestrate the bone remodeling adapted to mechanical loading. On the other hand, osteocytes are also considered as the unloading sensors in vivo. Previous studies showed that the mechanosensation and mechanotransduction of osteocytes may play an essential role in mediating bone response to microgravity, and one of the most important molecular signaling pathway involved in the mechanotransduction is the Wnt/ ß-catenin signaling pathway. In order to investigate the effect of simulated microgravity on the Wnt/ ß-catenin signaling pathway in osteocytes, MLO-Y4 cells (an osteocyte-like cell line) were cultured under controlled rotation to simulate microgravity for 5 days. The cytoskeleton and ß-catenin nuclear translocation of MLO-Y4 cells were detected by laser scanning confocal microscope and the fluorescence intensity was quantified; the mRNA expressions of upstream and downstream key components in Wnt canonical signaling were detected with RT-PCR. Two regulators of the Wnt/ ß-catenin pathway, NMP4/CIZ and Smads, were also investigated by RT-PCR; finally the expression of Wnt target genes and Sost protein level were detected with the absence or presence of the Sclerostin antibody (Scl-AbI) under simulated microgravity. The results showed that under simulated microgravity, (1) F-actin filaments were disassembled and some short dendritic processes appeared at the cell periphery; (2) the gene expression of Wnt3a, Wnt5a, DKK1, CyclinD1, LEF-1 and CX43 in the simulated microgravity group were significantly lower whereas Wnt1 and Sost in the simulated microgravity group were significantly higher than the control group; (3) the gene and protein level of ß-catenin were reduced, and no ß-catenin nuclear translocation observed; (4) the gene expression of Smad1, Smad4 and Smad7 were significantly lower whereas NMP4/CIZ and Smad3 in the simulated microgravity were significantly higher than the control group; (5) Scl-AbI partially inhibited the down-regulation of simulated microgravity to Wnt target gene expression and Sclerostin protein expression. The results suggested that firstly the cytoskeleton was disturbed in MLO-Y4 by simulated microgravity; secondly the activity of Wnt/ ß-catenin signaling pathway was depressed, with the nuclear translocation of ß-catenin suppressed by simulated microgravity; thirdly the Wnt/ ß-catenin signaling pathway positive regulators (Smads) were decreased, while the negative regulator (NMP4/CIZ) was increased under simulated microgravity; finally Scl-AbI could partially restore the adverse effect of simulated microgravity to Wnt signaling. This study may help us to understand the mechanotransduction alteration of Wnt/ ß-catenin signaling pathway in osteocytes under simulated microgravity, and further may partly clarify the mechanism of microgravity-induced osteoporosis.

Effect of saw palmetto extract on PI3K cell signaling transduction in human glioma

PubMed Central

YANG, YANG; HUI, LV; YUQIN, CHE; JIE, LI; SHUAI, HOU; TIEZHU, ZHOU; WEI, WANG

2014-01-01

Saw palmetto extract can induce the apoptosis of prostate cancer cells. The aim of the present study was to investigate the effect of saw palmetto extract on the phosphatidylinositol 3-kinase (PI3K)/Akt signaling transduction pathway in human glioma U87 and U251 cell lines. Suspensions of U87 and U251 cells in a logarithmic growth phase were seeded into six-well plates at a density of 104 cells/well. In the experimental group, 1 μl/ml saw palmetto extract was added, while the control group was cultured without a drug for 24 h. The expression levels of PI3K, B-cell lymphoma-extra large (Bcl-xL) and p53 were evaluated through western blot analysis. In the experimental group, the U87 and U251 cells exhibited a lower expression level of PI3K protein as compared with the control group (t=6.849; P<0.001). In addition, the two cell lines had a higher expression level of p53 protein in the experimental group as compared with the control group (t=40.810; P<0.001). Protein expression levels of Bcl-xL decreased significantly in the experimental group as compared with the control group (t=19.640; P=0.000). Therefore, saw palmetto extract induces glioma cell growth arrest and apoptosis via decreasing PI3K/Akt signal transduction. PMID:25009620

Constitutive overexpression of Norrin activates Wnt/β-catenin and endothelin-2 signaling to protect photoreceptors from light damage.

PubMed

Braunger, Barbara M; Ohlmann, Andreas; Koch, Marcus; Tanimoto, Naoyuki; Volz, Cornelia; Yang, Ying; Bösl, Michael R; Cvekl, Ales; Jägle, Herbert; Seeliger, Mathias W; Tamm, Ernst R

2013-02-01

Norrin is a retinal signaling molecule which is expressed in Müller glia and binds to Frizzled-4 to activate canonical Wnt/β-catenin signaling. Norrin is part of an essential signaling system that controls the formation of retinal capillaries during development. To evaluate neuroprotective properties of Norrin independently from its function during retinal angiogenesis, we generated transgenic mice (Rpe65-Norrin) that constitutively express Norrin in the retinal pigmented epithelium. Substantial amounts of Norrin were secreted into the outer retina, which triggered retinal Wnt/β-catenin signaling in conjunction with an increase in the expression of endothelin-2 (EDN2), endothelin receptor B (EDNRB), and glial fibrillary acidic protein (GFAP). Photoreceptors of Norrin-overexpressing mice were significantly less vulnerable to light-induced damage compared to their wild-type littermates. Following light damage, we observed less apoptotic death of photoreceptors and a better retinal function than in controls. The protective effects were abolished if either Wnt/β-catenin or EDN2 signaling was blocked by intravitreal injection of Dickkopf-1 or BQ788, respectively. Light-damaged retinae from transgenic mice contained higher amounts of brain-derived neurotrophic factor (BDNF) and pAkt than those of wild-type littermates. We conclude that constitutive overexpression of Norrin protects photoreceptors from light damage, an effect that is mediated by Wnt/β-catenin and EDN2 signaling and involves neurotrophic activities of BDNF. The findings suggest that Norrin and its associated signaling pathways have strong potentials to attenuate photoreceptor death following injury. Copyright © 2012 Elsevier Inc. All rights reserved.

Ly49H signaling through DAP10 is essential for optimal natural killer cell responses to mouse cytomegalovirus infection

PubMed Central

Orr, Mark T.; Sun, Joseph C.; Hesslein, David G.T.; Arase, Hisashi; Phillips, Joseph H.; Takai, Toshiyuki

2009-01-01

The activating natural killer (NK) cell receptor Ly49H recognizes the mouse cytomegalovirus (MCMV) m157 glycoprotein expressed on the surface of infected cells and is required for protection against MCMV. Although Ly49H has previously been shown to signal via DAP12, we now show that Ly49H must also associate with and signal via DAP10 for optimal function. In the absence of DAP12, DAP10 enables Ly49H-mediated killing of m157-bearing target cells, proliferation in response to MCMV infection, and partial protection against MCMV. DAP10-deficient Ly49H+ NK cells, expressing only Ly49H–DAP12 receptor complexes, are partially impaired in their ability to proliferate during MCMV infection, display diminished ERK1/2 activation, produce less IFN-γ upon Ly49H engagement, and demonstrate reduced control of MCMV infection. Deletion of both DAP10 and DAP12 completely abrogates Ly49H surface expression and control of MCMV infection. Thus, optimal NK cell–mediated immunity to MCMV depends on Ly49H signaling through both DAP10 and DAP12. PMID:19332875

JMJD1C Ensures Mouse Embryonic Stem Cell Self-Renewal and Somatic Cell Reprogramming through Controlling MicroRNA Expression.

PubMed

Xiao, Feng; Liao, Bing; Hu, Jing; Li, Shuang; Zhao, Haixin; Sun, Ming; Gu, Junjie; Jin, Ying

2017-09-12

The roles of histone demethylases (HDMs) for the establishment and maintenance of pluripotency are incompletely characterized. Here, we show that JmjC-domain-containing protein 1c (JMJD1C), an H3K9 demethylase, is required for mouse embryonic stem cell (ESC) self-renewal. Depletion of Jmjd1c leads to the activation of ERK/MAPK signaling and epithelial-to-mesenchymal transition (EMT) to induce differentiation of ESCs. Inhibition of ERK/MAPK signaling rescues the differentiation phenotype caused by Jmjd1c depletion. Mechanistically, JMJD1C, with the help of pluripotency factor KLF4, maintains ESC identity at least in part by regulating the expression of the miR-200 family and miR-290/295 cluster to suppress the ERK/MAPK signaling and EMT. Additionally, we uncover that JMJD1C ensures efficient generation and maintenance of induced pluripotent stem cells, at least partially through controlling the expression of microRNAs. Collectively, we propose an integrated model of epigenetic and transcriptional control mediated by the H3K9 demethylase for ESC self-renewal and somatic cell reprogramming. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Genome-Wide Identification and Expression Analysis of the Mitogen-Activated Protein Kinase Gene Family in Cassava

PubMed Central

Yan, Yan; Wang, Lianzhe; Ding, Zehong; Tie, Weiwei; Ding, Xupo; Zeng, Changying; Wei, Yunxie; Zhao, Hongliang; Peng, Ming; Hu, Wei

2016-01-01

Mitogen-activated protein kinases (MAPKs) play central roles in plant developmental processes, hormone signaling transduction, and responses to abiotic stress. However, no data are currently available about the MAPK family in cassava, an important tropical crop. Herein, 21 MeMAPK genes were identified from cassava. Phylogenetic analysis indicated that MeMAPKs could be classified into four subfamilies. Gene structure analysis demonstrated that the number of introns in MeMAPK genes ranged from 1 to 10, suggesting large variation among cassava MAPK genes. Conserved motif analysis indicated that all MeMAPKs had typical protein kinase domains. Transcriptomic analysis suggested that MeMAPK genes showed differential expression patterns in distinct tissues and in response to drought stress between wild subspecies and cultivated varieties. Interaction networks and co-expression analyses revealed that crucial pathways controlled by MeMAPK networks may be involved in the differential response to drought stress in different accessions of cassava. Expression of nine selected MAPK genes showed that these genes could comprehensively respond to osmotic, salt, cold, oxidative stressors, and abscisic acid (ABA) signaling. These findings yield new insights into the transcriptional control of MAPK gene expression, provide an improved understanding of abiotic stress responses and signaling transduction in cassava, and lead to potential applications in the genetic improvement of cassava cultivars. PMID:27625666

Single cell RNA Seq reveals dynamic paracrine control of cellular variation

PubMed Central

Shalek, Alex K.; Satija, Rahul; Shuga, Joe; Trombetta, John J.; Gennert, Dave; Lu, Diana; Chen, Peilin; Gertner, Rona S.; Gaublomme, Jellert T.; Yosef, Nir; Schwartz, Schraga; Fowler, Brian; Weaver, Suzanne; Wang, Jing; Wang, Xiaohui; Ding, Ruihua; Raychowdhury, Raktima; Friedman, Nir; Hacohen, Nir; Park, Hongkun; May, Andrew P.; Regev, Aviv

2014-01-01

High-throughput single-cell transcriptomics offers an unbiased approach for understanding the extent, basis, and function of gene expression variation between seemingly identical cells. Here, we sequence single-cell RNA-Seq libraries prepared from over 1,700 primary mouse bone marrow derived dendritic cells (DCs) spanning several experimental conditions. We find substantial variation between identically stimulated DCs, in both the fraction of cells detectably expressing a given mRNA and the transcript’s level within expressing cells. Distinct gene modules are characterized by different temporal heterogeneity profiles. In particular, a “core” module of antiviral genes is expressed very early by a few “precocious” cells, but is later activated in all cells. By stimulating cells individually in sealed microfluidic chambers, analyzing DCs from knockout mice, and modulating secretion and extracellular signaling, we show that this response is coordinated via interferon-mediated paracrine signaling. Surprisingly, preventing cell-to-cell communication also substantially reduces variability in the expression of an early-induced “peaked” inflammatory module, suggesting that paracrine signaling additionally represses part of the inflammatory program. Our study highlights the importance of cell-to-cell communication in controlling cellular heterogeneity and reveals general strategies that multicellular populations use to establish complex dynamic responses. PMID:24919153

Wingless, decapentaplegic and EGF receptor signaling pathways interact to specify dorso-ventral pattern in the adult abdomen of Drosophila.

PubMed

Kopp, A; Blackman, R K; Duncan, I

1999-08-01

Adult abdominal segments of Drosophila are subdivided along the dorso-ventral axis into a dorsal tergite, a ventral sternite and ventro-lateral pleural cuticle. We report that this pattern is largely specified during the pupal stage by Wingless (Wg), Decapentaplegic (Dpp) and Drosophila EGF Receptor (DER) signaling. Expression of wg and dpp is activated at the posterior edge of the anterior compartment by Hedgehog signaling. Within this region, wg and dpp are expressed in domains that are mutually exclusive along the dorso-ventral axis: wg is expressed in the sternite and medio-lateral tergite, whereas dpp expression is confined to the pleura and the dorsal midline. Neither gene is expressed in the lateral tergite. Shirras and Couso (1996, Dev. Biol. 175, 24-36) have shown that tergite and sternite cell fates are specified by Wg signaling. We find that DER acts synergistically with Wg to promote tergite and sternite identities, and that Wg and DER activities are opposed by Dpp signaling, which promotes pleural identity. Wg and Dpp interact antagonistically at two levels. First, their expression is confined to complementary domains by mutual transcriptional repression. Second, Wg and Dpp compete directly with one another by exerting opposite effects on cell fate. DER signaling does not affect the expression of wg or dpp, indicating that it interacts with Wg and Dpp at the level of cell fate determination. Within the tergite, the requirements for Wg and DER function are roughly complementary: Wg is required mainly in the medial region, whereas DER is most important laterally. Finally, we show that Dpp signaling at the dorsal midline controls dorso-ventral patterning within the tergite by promoting pigmentation in the medial region.

Insulin-like growth factor (IGF) signalling is required for early dorso-anterior development of the zebrafish embryo.

PubMed

Eivers, Edward; McCarthy, Karena; Glynn, Catherine; Nolan, Catherine M; Byrnes, Lucy

2004-12-01

The insulin-like growth factor (IGF) signalling pathway has been highly conserved in animal evolution and, in mammals and Xenopus, plays a key role in embryonic growth and development, with the IGF-1 receptor (IGF-1R) being a crucial regulator of the signalling cascade. Here we report the first functional role for the IGF pathway in zebrafish. Expression of mRNA coding for a dominant negative IGF-1R resulted in embryos that were small in size compared to controls and had disrupted head and CNS development. At its most extreme, this phenotype was characterized by a complete loss of head and eye structures, an absence of notochord and the presence of abnormal somites. In contrast, up-regulation of IGF signalling following injection of IGF-1 mRNA, resulted in a greatly expanded development of anterior structures at the expense of trunk and tail. IGF-1R knockdown caused a significant decrease in the expression of Otx2, Rx3, FGF8, Pax6.2 and Ntl, while excess IGF signalling expanded Otx2 expression in presumptive forebrain tissue and widened the Ntl expression domain in the developing notochord. The observation that IGF-1R knockdown reduced expression of two key organizer genes (chordin and goosecoid) suggests that IGF signalling plays a role in regulating zebrafish organizer activity. This is supported by the expression of IGF-1, IGF-2 and IGF-1R in shield-stage zebrafish embryos and the demonstration that IGF signalling influences expression of BMP2b, a gene that plays an important role in zebrafish pattern formation. Our data is consistent with a common pathway for integration of IGF, FGF8 and anti-BMPs in early vertebrate development.

FGF receptors control vitamin D and phosphate homeostasis by mediating renal FGF-23 signaling and regulating FGF-23 expression in bone.

PubMed

Wöhrle, Simon; Bonny, Olivier; Beluch, Noemie; Gaulis, Swann; Stamm, Christelle; Scheibler, Marcel; Müller, Matthias; Kinzel, Bernd; Thuery, Anne; Brueggen, Joseph; Hynes, Nancy E; Sellers, William R; Hofmann, Francesco; Graus-Porta, Diana

2011-10-01

The functional interaction between fibroblast growth factor 23 (FGF-23) and Klotho in the control of vitamin D and phosphate homeostasis is manifested by the largely overlapping phenotypes of Fgf23- and Klotho-deficient mouse models. However, to date, targeted inactivation of FGF receptors (FGFRs) has not provided clear evidence for an analogous function of FGFRs in this process. Here, by means of pharmacologic inhibition of FGFRs, we demonstrate their involvement in renal FGF-23/Klotho signaling and elicit their role in the control of phosphate and vitamin D homeostasis. Specifically, FGFR loss of function counteracts renal FGF-23/Klotho signaling, leading to deregulation of Cyp27b1 and Cyp24a1 and the induction of hypervitaminosis D and hyperphosphatemia. In turn, this initiates a feedback response leading to high serum levels of FGF-23. Further, we show that FGFR inhibition blocks Fgf23 transcription in bone and that this is dominant over vitamin D-induced Fgf23 expression, ultimately impinging on systemic FGF-23 protein levels. Additionally, we identify Fgf23 as a specific target gene of FGF signaling in vitro. Thus, in line with Fgf23- and Klotho-deficient mouse models, our study illustrates the essential function of FGFRs in the regulation of vitamin D and phosphate levels. Further, we reveal FGFR signaling as a novel in vivo control mechanism for Fgf23 expression in bone, suggesting a dual function of FGFRs in the FGF-23/Klotho pathway leading to vitamin D and phosphate homeostasis. Copyright © 2011 American Society for Bone and Mineral Research.

Elevated Expression of the NLRP3 Inflammasome and Its Correlation with Disease Activity in Adult-onset Still Disease.

PubMed

Hsieh, Chia-Wei; Chen, Yi-Ming; Lin, Chi-Chen; Tang, Kuo-Tung; Chen, Hsin-Hua; Hung, Wei-Ting; Lai, Kuo-Lung; Chen, Der-Yuan

2017-08-01

The dysregulation of the NLRP3 (NLR containing a pyrin domain) inflammasome is involved in autoinflammatory diseases. Adult-onset Still disease (AOSD) is regarded as an autoinflammatory disease. However, the pathogenic involvement of NLRP3 inflammasome in AOSD remains unclear and NLRP3 activators in AOSD are currently unknown. The mRNA expression of NLRP3 inflammasome signaling in peripheral blood mononuclear cells (PBMC) from 34 patients with AOSD and 14 healthy subjects was determined using quantitative-PCR (qPCR). The changes in mRNA and protein levels of NLRP3 inflammasome signaling in PBMC treated with the potential activator [imiquimod (IMQ)] or inhibitor of NLRP3 were evaluated using qPCR and immunoblotting, respectively. The supernatant levels of interleukin (IL)-1β and IL-18 were determined by ELISA. Significantly higher mRNA levels of NLRP3 inflammasome signaling were observed in patients with AOSD compared with healthy controls. NLRP3 expressions were positively correlated with disease activity in patients with AOSD. IMQ (an effective Toll-like receptor 7 ligand; 10 µ g/ml and 25 µ g/ml) stimulation of PBMC from patients with AOSD induced dose-dependent increases of mRNA expression of NLRP3 (mean ± standard error of the mean, 2.06 ± 0.46 and 6.05 ± 1.84, respectively), caspase-1 (1.81 ± 0.23 and 4.25 ± 0.48), IL-1β (5.68 ± 1.51 and 12.13 ± 3.71), and IL-18 (2.32 ± 0.37 and 4.81 ± 0.51) compared with controls (all p < 0.005). IMQ stimulation of PBMC from patients similarly induced greater increases in protein expressions of NLRP3 inflammasome compared with controls. The protein expressions of NLRP3, IL-1β, and IL-18 on PBMC significantly decreased after treatment with NLRP3 inhibitor in patients with AOSD. Increased expression of NLRP3 inflammasome and its positive correlation with disease activity in AOSD suggest its involvement in disease pathogenesis. IMQ upregulated expressions of NLRP3 inflammasome signaling, and IMQ might be an activator of NLRP3 inflammasome in AOSD.

Aberrant Chromatin Modification as a Mechanism of Prostate Cancer Progression

DTIC Science & Technology

2004-12-01

mediated control of gene expression. Using the antibody generated against phosphorylated histone H3 (from either Upstate Biotech or Cell Signaling), we...C4-2B cells (Fig 3 of Appendix 2). Interestingly, depletion of AR and ACTR affects the expression of distinct cell cycle genes. As shown in Fig 4A and...coactivator ACTR regulate the expression of different genes that are involved in control of cell cycle , suggesting that distinct mechanisms evolves

Dysregulation of hepatic microRNA expression profiles with Clonorchis sinensis infection.

PubMed

Han, Su; Tang, Qiaoran; Lu, Xi; Chen, Rui; Li, Yihong; Shu, Jing; Zhang, Xiaoli; Cao, Jianping

2016-11-30

Clonorchiasis remains an important zoonotic parasitic disease worldwide. The molecular mechanisms of host-parasite interaction are not fully understood. Non-coding microRNAs (miRNAs) are considered to be key regulators in parasitic diseases. The regulation of miRNAs and host micro-environment may be involved in clonorchiasis, and require further investigation. MiRNA microarray technology and bioinformatic analysis were used to investigate the regulatory mechanisms of host miRNA and to compare miRNA expression profiles in the liver tissues of control and Clonorchis sinensis (C. sinensis)-infected rats. A total of eight miRNAs were downregulated and two were upregulated, which showed differentially altered expression profiles in the liver tissue of C. sinensis-infected rats. Further analysis of the differentially expressed miRNAs revealed that many important signal pathways were triggered after infection with C. sinensis, which were related to clonorchiasis pathogenesis, such as cell apoptosis and inflammation, as well as genes involved in signal transduction mechanisms, such as pathways in cancer and the Wnt and Mitogen-activated protein kinases (MAPK) signaling pathways. The present study revealed that the miRNA expression profiles of the host were changed by C. sinensis infection. This dysregulation in miRNA expression may contribute to the etiology and pathophysiology of clonorchiasis. These results also provide new insights into the regulatory mechanisms of miRNAs in clonorchiasis, which may present potential targets for future C. sinensis control strategies.

Therapeutic Potential for Targeting the Suppressor of Cytokine Signaling-1 pathway for the treatment of SLE

PubMed Central

Sukka-Ganesh, Bhagyalaxmi; Larkin, Joseph

2016-01-01

Although the specific events dictating systemic lupus erythematosus (SLE) pathology remain unclear, abundant evidence indicates a critical role for dysregulated cytokine signaling in disease progression. Notably, the suppressor of cytokine signaling (SOCS) family of intracellular proteins, in particular the kinase inhibitory region (KIR) bearing SOCS1 and SOCS3, play a critical role in regulating cytokine signaling. To assess a relationship between SOCS1/SOCS3 expression and SLE, the goals of this study were to: 1) evaluate the time kinetics of SOCS1/SOCS3 message and protein expression based on SLE associated stimulations, 2) compare levels of SOCS1 and SOCS3 present in SLE patients and healthy controls by message and protein, 3) relate SOCS1/SOCS3 expression to inflammatory markers in SLE patients, and 4) correlate SOCS1/SOCS3 levels to current treatments. We found that SOCS1 and SOCS3 were most abundant in murine splenic samples at 48 hours subsequent to stimulation by anti-CD3, LPS, or interferon gamma. In addition, significant reductions in SOCS1 and SOCS3 were present within PMBC’s of SLE patients compared to controls by both mRNA and protein expression. We also found that decreased levels of SOCS1 in SLE patients were correlated to enhanced levels of inflammatory markers and up-regulated expression of MHC class II. Finally, we show that patients receiving steroid treatment possessed higher levels SOCS1 compared to SLE patient counterparts, and that steroid administration to human PBMCs up-regulated SOCS1 message in a dose and time dependent manner. Together, these results suggest that therapeutic strategies focused on SOCS1 signaling may have efficacy in the treatment of SLE. PMID:27781323

MEMBRANE-TYPE 1 MATRIX METALLOPROTEINASE DOWNREGULATES FIBROBLAST GROWTH FACTOR-2 BINDING TO THE CELL SURFACE AND INTRACELLULAR SIGNALING

PubMed Central

Tassone, Evelyne; Valacca, Cristina; Mignatti, Paolo

2014-01-01

Membrane-type 1 matrix metalloproteinase (MT1-MMP, MMP-14), a transmembrane proteinase with an extracellular catalytic domain and a short cytoplasmic tail, degrades extracellular matrix components and controls diverse cell functions through proteolytic and non-proteolytic interactions with extracellular, intracellular and transmembrane proteins. Here we show that in tumor cells MT1-MMP downregulates fibroblast growth factor-2 (FGF-2) signaling by reducing the amount of FGF-2 bound to the cell surface with high and low affinity. FGF-2 induces weaker activation of ERK1/2 MAP kinase in MT1-MMP expressing cells than in cells devoid of MT1-MMP. This effect is abolished in cells that express proteolytically inactive MT1-MMP but persists in cells expressing MT1-MMP mutants devoid of hemopexin-like or cytoplasmic domain, showing that FGF-2 signaling is downregulated by MT1-MMP proteolytic activity. MT1-MMP expression results in downregulation of FGFR-1 and -4, and in decreased amount of cell surface-associated FGF-2. In addition, MT1-MMP strongly reduces the amount of FGF-2 bound to the cell surface with low affinity. Because FGF-2 association with low-affinity binding sites is a prerequisite for binding to its high-affinity receptors, downregulation of low-affinity binding to the cell surface results in decreased FGF-2 signaling. Consistent with this conclusion, FGF-2 induction of tumor cell migration and invasion in vitro is stronger in cells devoid of MT1-MMP than in MT1-MMP expressing cells. Thus, MT1-MMP controls FGF-2 signaling by a proteolytic mechanism that decreases the cell’s biological response to FGF-2. PMID:24986796

Histone deacetylase 3 supports endochondral bone formation by controlling cytokine signaling and matrix remodeling

PubMed Central

Carpio, Lomeli R.; Bradley, Elizabeth W.; McGee-Lawrence, Meghan E.; Weivoda, Megan M.; Poston, Daniel D.; Dudakovic, Amel; Xu, Ming; Tchkonia, Tamar; Kirkland, James L.; van Wijnen, Andre J.; Oursler, Merry Jo; Westendorf, Jennifer J.

2017-01-01

Histone deacetylase (HDAC) inhibitors are efficacious epigenetic-based therapies for some cancers and neurological disorders; however, each of these drugs inhibits multiple HDACs and has detrimental effects on the skeleton. To better understand how HDAC inhibitors affect endochondral bone formation, we conditionally deleted one of their targets, Hdac3, pre- and postnatally in type II collagen α1 (Col2α1)–expressing chondrocytes. Embryonic deletion was lethal, but postnatal deletion of Hdac3 delayed secondary ossification center formation, altered maturation of growth plate chondrocytes, and increased osteoclast activity in the primary spongiosa. HDAC3-deficient chondrocytes exhibited increased expression of cytokine and matrix-degrading genes (Il-6, Mmp3, Mmp13, and Saa3) and a reduced abundance of genes related to extracellular matrix production, bone development, and ossification (Acan, Col2a1, Ihh, and Col10a1). Histone acetylation increased at and near genes that had increased expression. The acetylation and activation of nuclear factor κB (NF-κB) were also increased in HDAC3-deficient chondrocytes. Increased cytokine signaling promoted autocrine activation of Janus kinase (JAK)–signal transducer and activator of transcription (STAT) and NF-κB pathways to suppress chondrocyte maturation, as well as paracrine activation of osteoclasts and bone resorption. Blockade of interleukin-6 (IL-6)–JAK–STAT signaling, NF-κB signaling, and bromodomain extraterminal proteins, which recognize acetylated lysines and promote transcriptional elongation, significantly reduced Il-6 and Mmp13 expression in HDAC3-deficient chondrocytes and secondary activation in osteoclasts. The JAK inhibitor ruxolitinib also reduced osteoclast activity in Hdac3 conditional knockout mice. Thus, HDAC3 controls the temporal and spatial expression of tissue-remodeling genes and inflammatory responses in chondrocytes to ensure proper endochondral ossification during development. PMID:27507649

Gene expression in gastrointestinal stromal tumors is distinguished by KIT genotype and anatomic site.

PubMed

Antonescu, Cristina R; Viale, Agnes; Sarran, Lisa; Tschernyavsky, Sylvia J; Gonen, Mithat; Segal, Neil H; Maki, Robert G; Socci, Nicholas D; DeMatteo, Ronald P; Besmer, Peter

2004-05-15

Gastrointestinal stromal tumors (GISTs) are specific KIT expressing and KIT-signaling driven mesenchymal tumors of the human digestive tract, many of which have KIT-activating mutations. Previous studies have found a relatively homogeneous gene expression profile in GIST, as compared with other histological types of sarcomas. Transcriptional heterogeneity within clinically or molecularly defined subsets of GISTs has not been previously reported. We tested the hypothesis that the gene expression profile in GISTs might be related to KIT genotype and possibly to other clinicopathological factors. An HG-U133A Affymetrix chip (22,000 genes) platform was used to determine the variability of gene expression in 28 KIT-expressing GIST samples from 24 patients. A control group of six intra-abdominal leiomyosarcomas was also included for comparison. Statistical analyses (t tests) were performed to identify discriminatory gene lists among various GIST subgroups. The levels of expression of various GIST subsets were also linked to a modified version of the growth factor/KIT signaling pathway to analyze differences at various steps in signal transduction. Genes involved in KIT signaling were differentially expressed among wild-type and mutant GISTs. High gene expression of potential drug targets, such as VEGF, MCSF, and BCL2 in the wild-type group, and Mesothelin in exon 9 GISTs were found. There was a striking difference in gene expression between stomach and small bowel GISTs. This finding was validated in four separate tumors, two gastric and two intestinal, from a patient with familial GIST with a germ-line KIT W557R substitution. GISTs have heterogeneous gene expression depending on KIT genotype and tumor location, which is seen at both the genomic level and the KIT signaling pathway in particular. These findings may explain their variable clinical behavior and response to therapy.

Mediation of oxidative stress in hypothalamic ghrelin-associated appetite control in rats treated with phenylpropanolamine.

PubMed

Yu, C-H; Chu, S-C; Chen, P-N; Hsieh, Y-S; Kuo, D-Y

2017-04-01

Phenylpropanolamine (PPA)-induced appetite control is associated with oxidative stress in the hypothalamus. This study explored whether hypothalamic antioxidants participated in hypothalamic ghrelin system-associated appetite control in PPA-treated rats. Rats were given PPA daily for 4 days, and changes in food intake and the expression of neuropeptide Y (NPY), the cocaine- and amphetamine-regulated transcript (CART), superoxide dismutase, catalase, ghrelin, acyl ghrelin (AG), ghrelin O-acyltransferase (GOAT) and the ghrelin receptor (GHSR1a) were examined and compared. Results showed that both food intake and the expression of NPY and ghrelin/AG/GOAT/GHSR1a decreased in response to PPA treatment with maximum decrease on Day 2 of the treatment. In contrast, the expression of antioxidants and CART increased, with the maximum increase on Day 2, with the expression opposite to that of NPY and ghrelin. A cerebral infusion of either a GHSR1a antagonist or reactive oxygen species scavenger modulated feeding behavior and NPY, CART, antioxidants and ghrelin system expression, showing the involvement of ghrelin signaling and oxidative stress in regulating PPA-mediated appetite control. We suggest that hypothalamic ghrelin signaling system, with the help of antioxidants, may participate in NPY/CART-mediated appetite control in PPA-treated rats. © 2016 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

From deep-sea volcanoes to human pathogens: a conserved quorum-sensing signal in Epsilonproteobacteria.

PubMed

Pérez-Rodríguez, Ileana; Bolognini, Marie; Ricci, Jessica; Bini, Elisabetta; Vetriani, Costantino

2015-05-01

Chemosynthetic Epsilonproteobacteria from deep-sea hydrothermal vents colonize substrates exposed to steep thermal and redox gradients. In many bacteria, substrate attachment, biofilm formation, expression of virulence genes and host colonization are partly controlled via a cell density-dependent mechanism involving signal molecules, known as quorum sensing. Within the Epsilonproteobacteria, quorum sensing has been investigated only in human pathogens that use the luxS/autoinducer-2 (AI-2) mechanism to control the expression of some of these functions. In this study we showed that luxS is conserved in Epsilonproteobacteria and that pathogenic and mesophilic members of this class inherited this gene from a thermophilic ancestor. Furthermore, we provide evidence that the luxS gene is expressed--and a quorum-sensing signal is produced--during growth of Sulfurovum lithotrophicum and Caminibacter mediatlanticus, two Epsilonproteobacteria from deep-sea hydrothermal vents. Finally, we detected luxS transcripts in Epsilonproteobacteria-dominated biofilm communities collected from deep-sea hydrothermal vents. Taken together, our findings indicate that the epsiloproteobacterial lineage of the LuxS enzyme originated in high-temperature geothermal environments and that, in vent Epsilonproteobacteria, luxS expression is linked to the production of AI-2 signals, which are likely produced in situ at deep-sea vents. We conclude that the luxS gene is part of the ancestral epsilonproteobacterial genome and represents an evolutionary link that connects thermophiles to human pathogens.

NADPH Oxidase 1 Modulates WNT and NOTCH1 Signaling To Control the Fate of Proliferative Progenitor Cells in the Colon▿

PubMed Central

Coant, Nicolas; Ben Mkaddem, Sanae; Pedruzzi, Eric; Guichard, Cécile; Tréton, Xavier; Ducroc, Robert; Freund, Jean-Noel; Cazals-Hatem, Dominique; Bouhnik, Yoram; Woerther, Paul-Louis; Skurnik, David; Grodet, Alain; Fay, Michèle; Biard, Denis; Lesuffleur, Thécla; Deffert, Christine; Moreau, Richard; Groyer, André; Krause, Karl-Heinz; Daniel, Fanny; Ogier-Denis, Eric

2010-01-01

The homeostatic self-renewal of the colonic epithelium requires coordinated regulation of the canonical Wnt/β-catenin and Notch signaling pathways to control proliferation and lineage commitment of multipotent stem cells. However, the molecular mechanisms by which the Wnt/β-catenin and Notch1 pathways interplay in controlling cell proliferation and fate in the colon are poorly understood. Here we show that NADPH oxidase 1 (NOX1), a reactive oxygen species (ROS)-producing oxidase that is highly expressed in colonic epithelial cells, is a pivotal determinant of cell proliferation and fate that integrates Wnt/β-catenin and Notch1 signals. NOX1-deficient mice reveal a massive conversion of progenitor cells into postmitotic goblet cells at the cost of colonocytes due to the concerted repression of phosphatidylinositol 3-kinase (PI3K)/AKT/Wnt/β-catenin and Notch1 signaling. This conversion correlates with the following: (i) the redox-dependent activation of the dual phosphatase PTEN, causing the inactivation of the Wnt pathway effector β-catenin, and (ii) the downregulation of Notch1 signaling that provokes derepression of mouse atonal homolog 1 (Math1) expression. We conclude that NOX1 controls the balance between goblet and absorptive cell types in the colon by coordinately modulating PI3K/AKT/Wnt/β-catenin and Notch1 signaling. This finding provides the molecular basis for the role of NOX1 in cell proliferation and postmitotic differentiation. PMID:20351171

Tomato Lycopene Extract Prevents Lipopolysaccharide-Induced NF-κB Signaling but Worsens Dextran Sulfate Sodium-Induced Colitis in NF-κBEGFP Mice

PubMed Central

Joo, Young-Eun; Karrasch, Thomas; Mühlbauer, Marcus; Allard, Brigitte; Narula, Acharan; Herfarth, Hans H.; Jobin, Christian

2009-01-01

Background The impact of tomato lycopene extract (TLE) on intestinal inflammation is currently unknown. We investigated the effect of TLE on lipopolysaccharide (LPS)-induced innate signaling and experimental colitis. Methodology/Principal Findings Mice were fed a diet containing 0.5 and 2% TLE or isoflavone free control (AIN-76). The therapeutic efficacy of TLE diet was assessed using dextran sulfate sodium (DSS) exposed mice and IL-10−/−;NF-κBEGFP mice, representing an acute and spontaneous chronic colitis model respectively. A mini-endoscope was used to determine the extent of macroscopic mucosal lesions. Murine splenocytes and intestinal epithelial cells were used to determine the in vitro impact of TLE on LPS-induced NF-κB signaling. In vitro, TLE blocked LPS-induced IκBα degradation, RelA translocation, NF-κB transcriptional activity and MIP-2 mRNA accumulation in IEC-18 cells. Moreover, LPS-induced IL-12p40 gene expression was dose-dependently inhibited in TLE-treated splenocytes. Interestingly, DSS-induced acute colitis worsened in TLE-fed NF-κBEGFP mice compared to control diet as measured by weight loss, colonoscopic analysis and histological scores. In contrast, TLE-fed IL-10−/−;NF-κBEGFP mice displayed decreased colonic EGFP expression compared to control diet. IL-6, TNFα, and MCP-1 mRNA expression were increased in the colon of TLE-fed, DSS-exposed NF-κBEGFP mice compared to the control diet. Additionally, caspase-3 activation and TUNEL positive cells were enhanced in TLE diet-fed, DSS-exposed mice as compared to DSS control mice. Conclusions/ Significance These results indicate that TLE prevents LPS-induced proinflammatory gene expression by blocking of NF-κB signaling, but aggravates DSS-induced colitis by enhancing epithelial cell apoptosis. PMID:19234608

Bystander signaling in C. elegans: proton microbeam studies

PubMed Central

Nelson, Gregory; Jones, Tamako; Ortloff, Leticia; Ford, John; Nuñez, Delia; Braby, Leslie

2014-01-01

Biological model: In this project, we investigated the control of radiation-induced genotoxic damage expression in somatic cells of the nematode Caenorhabditis elegans. We measured genotoxic damage in the C. elegans intestine by irradiating young larvae with 20 intestinal cells. Fourteen of these cells undergo exactly one nuclear division without cytoplasmic division leading to 14 binucleate cells. This nuclear division is synchronized and occurs at the first larval molt. Irradiation induces chromosome aberrations including dicentrics which we can quantify as stable anaphase bridges in the binucleate cells of young adult intestines. The endpoint is dose- and LET-dependent and we have demonstrated that individual intestinal cells have unique radiosensitivities. Results: The project has two components, a genetic screen for genes that control cell sensitivity and a microbeam component to directly probe individual cells. The genetic screen has identified several genes in NHEJ repair and telomere metabolism that modulate overall bridge frequency. Knockout mutants of cku-70, cku-80 and lig-4 greatly sensitize animals for anaphase bridge induction. A statistical method was used to determine whether induction of bridges was strictly random and cell autonomous and we determined that expression of bridges in pairs of cells was, in fact, non-random which suggested that signaling between cells affected the pattern of bridge expression. This allowed us to conduct an RNAi and mutation screen for genes that control the signaling (block non-random distributions) and several candidates have been identified. To directly test the notion that signaling of genotoxic damage occurs, we conducted experiments with alpha particles collimated through slits in metal foils and showed that genotoxic damage could be expressed many cell diameters away from a partial body exposure site. Thus, an in vivo bystander effect was demonstrated. Dose targeting was then improved to small regional exposures and eventually to individual cell targeting using 2 MeV protons from the microbeam facility at Texas A&M University. We now employ a green fluorescent protein (GFP)-expressing transgenic worm (rrIs1[elt-2::GFP]) to target GFP-positive gut cells via the gut-specific transcription factor elt-2. This allows alignment of the cell of interest over the microbeam aperture under appropriate fluorescence illumination. Microbeam irradiation experiments for many pairwise combinations of cell signal transmission and reception (observed as expression of anaphase bridges) have been conducted and several interesting patterns emerge. (i) The signaling pattern is cell-specific and does not simply reflect cell–cell distance or require direct contact between cell pairs. (ii) The signal range can be as far as from cell pair 2 to cell pair 8 (>100 µm). (iii) There appears to be a functional compartment boundary at the pharynx/intestine valve as even high-dose exposures to the posterior pharyngeal bulb fail to induce bridges in nearby intestinal cells. (iv) The frequency of signal transmission and reception corresponds broadly to the overall frequency of bridges observed during whole-body irradiations which suggests that direct irradiation and ‘out-of-field’ effects may be additive. These patterns have been analyzed in terms of a cellular logic circuit map for signal transmission and reception. A dose–response for a subset of microbeam-targeted cells was measured over the range of 5–20 Gy. Controlled cell pair targeting was used to test the potential additivity of signals and we found that effects were supra-additive. Finally, preliminary measurements were conducted on GFP-expressing transgenic strains that bore cku-70(tm1524) III and smk-1(mn156) V mutations which confer enhanced radiosensitivity. Cku-70 is a Ku-70 ortholog while smk-1 is orthologous to the mammalian and Dictyostelium discoideum SMEK (suppressor of MEK null) protein. In the cku-70(0/0) strain, the severity of the bridges in bystander cells was enhanced, suggesting that signal recipient cells employ NHEJ repair pathways in the expression of anaphase bridges. Clinical trial registration number: Not applicable.

Suppressor of cytokine signalling (SOCS) 1 and 3 enhance cell adhesion and inhibit migration towards the chemokine eotaxin/CCL11.

PubMed

Stevenson, Nigel J; McFarlane, Cheryl; Ong, Seow Theng; Nahlik, Krystyna; Kelvin, Alyson; Addley, Mark R; Long, Aideen; Greaves, David R; O'Farrelly, Cliona; Johnston, James A

2010-11-05

Suppressors of cytokine signalling (SOCS) proteins regulate signal transduction, but their role in responses to chemokines remains poorly understood. We report that cells expressing SOCS1 and 3 exhibit enhanced adhesion and reduced migration towards the chemokine CCL11. Focal adhesion kinase (FAK) and the GTPase RhoA, control cell adhesion and migration and we show the presence of SOCS1 or 3 regulates expression and tyrosine phosphorylation of FAK, while also enhancing activation of RhoA. Our novel findings suggest that SOCS1 and 3 may control chemotaxis and adhesion by significantly enhancing both FAK and RhoA activity, thus localizing immune cells to the site of allergic inflammation. Copyright © 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Activated Notch signaling cascade is correlated with stem cell differentiation toward absorptive progenitors after massive small bowel resection in a rat.

PubMed

Sukhotnik, Igor; Coran, Arnold G; Pollak, Yulia; Kuhnreich, Eviatar; Berkowitz, Drora; Saxena, Amulya K

2017-09-01

Notch signaling is thought to act to drive cell versification in the lining of the small intestine. The purpose of the present study was to evaluate the role of the Notch signaling pathway in stem cell differentiation in the late stages of intestinal adaptation after massive small bowel resection in a rat. Male Sprague-Dawley rats were randomly assigned to one of two experimental groups of eight rats each: Sham rats underwent bowel transection and reanastomosis, while SBS rats underwent 75% small bowel resection. Rats were euthanized on day 14 Illumina's Digital Gene Expression (DGE) analysis was used to determine Notch signaling gene expression profiling. Notch-related gene and protein expression was determined using real-time PCR, Western blot analysis, and immunohistochemistry. From seven investigated Notch-related (by DGE analysis) genes, six genes were upregulated in SBS vs. control animals with a relative change in gene expression level of 20% or more. A significant upregulation of Notch signaling-related genes in resected animals was accompanied by a significant increase in Notch-1 protein levels (Western blot analysis) and a significant increase in the number of Notch1 and Hes1 (target gene)-positive cells (immunohistochemistry) compared with sham animals. Evaluation of cell differentiation has shown a strong increase in total number of absorptive cells (unchanged secretory cells) compared with control rats. In conclusion, 2 wk after bowel resection in rats, stimulated Notch signaling directs the crypt cell population toward absorptive progenitors. NEW & NOTEWORTHY This study provides novel insight into the mechanisms of cell proliferation following massive small bowel resection. We show that 2 wk after bowel resection in rats, enhanced stem cell activity was associated with stimulated Notch signaling pathway. We demonstrate that activated Notch signaling cascade directs the crypt cell population toward absorptive progenitors. Copyright © 2017 the American Physiological Society.

BMP regulates regional gene expression in the dorsal otocyst through canonical and non-canonical intracellular pathways

PubMed Central

2016-01-01

The inner ear consists of two otocyst-derived, structurally and functionally distinct components: the dorsal vestibular and ventral auditory compartments. BMP signaling is required to form the vestibular compartment, but how it complements other required signaling molecules and acts intracellularly is unknown. Using spatially and temporally controlled delivery of signaling pathway regulators to developing chick otocysts, we show that BMP signaling regulates the expression of Dlx5 and Hmx3, both of which encode transcription factors essential for vestibular formation. However, although BMP regulates Dlx5 through the canonical SMAD pathway, surprisingly, it regulates Hmx3 through a non-canonical pathway involving both an increase in cAMP-dependent protein kinase A activity and the GLI3R to GLI3A ratio. Thus, both canonical and non-canonical BMP signaling establish the precise spatiotemporal expression of Dlx5 and Hmx3 during dorsal vestibular development. The identification of the non-canonical pathway suggests an intersection point between BMP and SHH signaling, which is required for ventral auditory development. PMID:27151948

Functional characterization of TRAP1-like protein involved in modulating fibrotic processes mediated by TGF-β/Smad signaling in hypertrophic scar fibroblasts

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

Wang, X.; Department of Pediatric Surgery, Shanghai Children’s Medical Center, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200127; Chu, J.

2015-03-15

The transforming growth factor-β1 (TGF-β)-mediated signaling pathway is believed to be closely associated with wound healing and scar formation, in which TRAP1-like protein (TLP) plays a role in regulating the balance of Smad2 vs. Smad3 signaling. Our previous study revealed the relation between TLP and collagen synthesis in normal human skin fibroblasts. Here, we present a detailed analysis of the effects of TLP on the process of hypertrophic scar formation and contraction. To explore and verify a contribution of TLP to the pathological mechanism of hypertrophic scar fibroblasts (HSFb), we constructed lentiviral vectors that either overexpressed TLP or encoded smallmore » hairpin RNAs (shRNAs) targeting TLP, then we transfected them into HSFb. TLP knockdown in HSFb resulted in reduced levels of cell contraction, type I and type III collagen mRNA transcripts and protein expression, and higher levels of fibronectin (FN) compared to control groups. In addition, knockdown of TLP promoted the phosphorylation of Smad3 but repressed Smad2 and Erk-1/2 phosphorylation in human hypertrophic scar fibroblasts compared to control groups. The reduction of TLP did not interfere with HSF proliferative ability, but exogenous TLP cooperated with TGF-β1 to increase cell viability. Together, our findings demonstrate evidence for a contribution of TLP expression in hypertrophic scar formation and contraction. - Highlights: • TLP acted different roles in the activating of Smad2- and Smad3-dependent signaling. • TLP may induce TGF-β1-mediated collagens expression through Smad signalings and MAPK signaling. • TLP may enhance HSFb contraction by increasing the expression of α-SMA. • Exogenous TLP can cooperate with TGF-β1 to increase cell viability.« less

Transforming growth factor-beta regulates mammary carcinoma cell survival and interaction with the adjacent microenvironment.

PubMed

Bierie, Brian; Stover, Daniel G; Abel, Ty W; Chytil, Anna; Gorska, Agnieszka E; Aakre, Mary; Forrester, Elizabeth; Yang, Li; Wagner, Kay-Uwe; Moses, Harold L

2008-03-15

Transforming growth factor (TGF)-beta signaling has been associated with early tumor suppression and late tumor progression; however, many of the mechanisms that mediate these processes are not known. Using Cre/LoxP technology, with the whey acidic protein promoter driving transgenic expression of Cre recombinase (WAP-Cre), we have now ablated the type II TGF-beta receptor (T beta RII) expression specifically within mouse mammary alveolar progenitors. Transgenic expression of the polyoma virus middle T antigen, under control of the mouse mammary tumor virus enhancer/promoter, was used to produce mammary tumors in the absence or presence of Cre (T beta RII((fl/fl);PY) and T beta RII((fl/fl);PY;WC), respectively). The loss of TGF-beta signaling significantly decreased tumor latency and increased the rate of pulmonary metastasis. The loss of TGF-beta signaling was significantly correlated with increased tumor size and enhanced carcinoma cell survival. In addition, we observed significant differences in stromal fibrovascular abundance and composition accompanied by increased recruitment of F4/80(+) cell populations in T beta RII((fl/fl);PY;WC) mice when compared with T beta RII((fl/fl);PY) controls. The recruitment of F4/80(+) cells correlated with increased expression of known inflammatory genes including Cxcl1, Cxcl5, and Ptgs2 (cyclooxygenase-2). Notably, we also identified an enriched K5(+) dNp63(+) cell population in primary T beta RII((fl/fl);PY;WC) tumors and corresponding pulmonary metastases, suggesting that loss of TGF-beta signaling in this subset of carcinoma cells can contribute to metastasis. Together, our current results indicate that loss of TGF-beta signaling in mammary alveolar progenitors may affect tumor initiation, progression, and metastasis through regulation of both intrinsic cell signaling and adjacent stromal-epithelial interactions in vivo.

Proteolytic degradation of regulator of G protein signaling 2 facilitates temporal regulation of Gq/11 signaling and vascular contraction.

PubMed

Kanai, Stanley M; Edwards, Alethia J; Rurik, Joel G; Osei-Owusu, Patrick; Blumer, Kendall J

2017-11-24

Regulator of G protein signaling 2 (RGS2) controls signaling by receptors coupled to the G q/11 class heterotrimeric G proteins. RGS2 deficiency causes several phenotypes in mice and occurs in several diseases, including hypertension in which a proteolytically unstable RGS2 mutant has been reported. However, the mechanisms and functions of RGS2 proteolysis remain poorly understood. Here we addressed these questions by identifying degradation signals in RGS2, and studying dynamic regulation of G q/11 -evoked Ca 2+ signaling and vascular contraction. We identified a novel bipartite degradation signal in the N-terminal domain of RGS2. Mutations disrupting this signal blunted proteolytic degradation downstream of E3 ubiquitin ligase binding to RGS2. Analysis of RGS2 mutants proteolyzed at various rates and the effects of proteasome inhibition indicated that proteolytic degradation controls agonist efficacy by setting RGS2 protein expression levels, and affecting the rate at which cells regain agonist responsiveness as synthesis of RGS2 stops. Analyzing contraction of mesenteric resistance arteries supported the biological relevance of this mechanism. Because RGS2 mRNA expression often is strikingly and transiently up-regulated and then down-regulated upon cell stimulation, our findings indicate that proteolytic degradation tightly couples RGS2 transcription, protein levels, and function. Together these mechanisms provide tight temporal control of G q/11 -coupled receptor signaling in the cardiovascular, immune, and nervous systems. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

[Expression of ICAT and Wnt signaling-related proteins in the monocytic differentiation of HL-60 cells induced by a new steroidal drug NSC67657].

PubMed

Wang, J S; Wang, W J; Wang, T; Zhang, Y

2016-04-01

To investigate the expression of mRNA and proteins of β-catenin, TCF-4 (ICAT) and Wnt signaling pathway-related genes in the monocytic differentiation of acute myeloid leukemia HL-60 cells induced by a new steroidal drug NSC67657. Wright's staining and α-NBE staining were used to observe the differentiation of HL-60 cells after 5 days of 10 μmol/L NSC67657 treatment. Flow cytometry (FCM) was used to detect the differentiation and cell cycles. The expressions of mRNA and proteins of ICAT and Wnt signaling pathway-related factors, including β-catenin, TCF-4, c-myc, cyclin D1 and TCF-1 before and after differentiation, were detected by RT-PCR and Western blot. Morphological observation showed that NSC67657 induced monocytic differentiation of HL-60 cells. At 5 days after 10 μmol/L NSC67657 treatment, the number of CD14(+) HL-60 cells was (94.37±2.84)%, significantly higher than the (1.31±0.09)% in control group (P<0.01). The flow cytometry assay revealed that NSC67657 induced (76.46±2.83)% of G1/G0 phase arrest, significantly higher than that of (59.40±5.42)% in the control group (P<0.05), while the S phase cells were of (18.76±0.98)%, significantly lower than that of (34.38±2.61) % in the control group (P<0.05). The NSC67657 treatment also up-regulated the expression of ICAT mRNA and protein, and down-regulated the expression of β-catenin mRNA and protin (P<0.01 for all). However, the nuclear expression of β-catenin was down-regulated (P<0.01). The NSC67657 treatment induced nonsignificant alterations of TCF-4 mRNA, total protein and nuclear protein in the HL-60 cells (P>0.05 for all). The target genes of Wnt signaling pathway, including c-myc, cyclinD1 and TCF-1 mRNA and proteins in the HL-60 cells were significantly down-regulated after NSC67657 treatment (P<0.05). The new steroidal drug NSC67657 induces monocytic differentiation of HL-60 cells, and down-regulates the expression of β-catenin and target genes of Wnt signaling pathway. These results indicate that Wnt signaling pathway may be directly or indirectly involved in the monocytic differentiation process of HL-60 cells.

Altered gene expression in tree shrew retina and retinal pigment epithelium produced by short periods of minus-lens wear.

PubMed

He, Li; Frost, Michael R; Siegwart, John T; Norton, Thomas T

2018-03-01

Hyperopic refractive error is detected by retinal neurons, which generate GO signals through a direct emmetropization signaling cascade: retinal pigment epithelium (RPE) into choroid and then into sclera, thereby increasing axial elongation. To examine signaling early in this cascade, we measured gene expression in the retina and RPE after short exposure to hyperopia produced by minus-lens wear. Gene expression in each tissue was compared with gene expression in combined retina + RPE. Starting 24 days after normal eye opening, three groups of juvenile tree shrews (n = 7 each) wore a monocular -5 D lens. The untreated fellow eye served as a control. The "6h" group wore the lens for 6 h; the "24h" group wore the lens for 24 h; each group provided separate retina and RPE tissues. Group "24hC" wore the lens for 24 h and provided combined retina + RPE tissue. Quantitative PCR was used to measure the relative differences (treated eye vs. control eye) in mRNA levels for 66 candidate genes. In the retina after 6 h, mRNA levels for seven genes were significantly regulated: EGR1 and FOS (early intermediate genes) were down-regulated in the treated eyes. Genes with secreted protein products, BMP2 and CTGF, were down-regulated, whilst FGF10, IL18, and SST were up-regulated. After 24 h the pattern changed; only one of the seven genes still showed differential expression; BMP2 was still down-regulated. Two new genes with secreted protein products, IGF2 and VIP, were up-regulated. In the RPE, consistent with its role in receiving, processing, and transmitting GO signaling, differential expression was found for genes whose protein products are at the cell surface, intracellular, in the nucleus, and are secreted. After 6 h, mRNA levels for 17 genes were down-regulated in the treated eyes, whilst four genes (GJA1, IGF2R, LRP2, and IL18) were up-regulated. After 24 h the pattern was similar; mRNA levels for 14 of the same genes were still down-regulated; only LRP2 remained up-regulated. mRNA levels for six genes no longer showed differential expression, whilst nine genes, not differentially expressed at 6 h, now showed differential expression. In the combined retina + RPE after 24 h, mRNA levels for only seven genes were differentially regulated despite the differential expression of many genes in the RPE. Four genes showed the same expression in combined tissue as in retina alone, including up-regulation of VIP despite significant VIP down-regulation in RPE. Thus, hyperopia-induced GO signaling, as measured by differential gene expression, differs in the retina and the RPE. Retinal gene expression changed between 6 h and 24 h of treatment, suggesting evolution of the retinal response. Gene expression in the RPE was similar at both time points, suggesting sustained signaling. The combined retina + RPE does not accurately represent gene expression in either retina or, especially, RPE. When gene expression signatures were compared with those in choroid and sclera, GO signaling, as encoded by differential gene expression, differs in each compartment of the direct emmetropization signaling cascade. Copyright © 2018 Elsevier Ltd. All rights reserved.

Digital signaling decouples activation probability and population heterogeneity.

PubMed

Kellogg, Ryan A; Tian, Chengzhe; Lipniacki, Tomasz; Quake, Stephen R; Tay, Savaş

2015-10-21

Digital signaling enhances robustness of cellular decisions in noisy environments, but it is unclear how digital systems transmit temporal information about a stimulus. To understand how temporal input information is encoded and decoded by the NF-κB system, we studied transcription factor dynamics and gene regulation under dose- and duration-modulated inflammatory inputs. Mathematical modeling predicted and microfluidic single-cell experiments confirmed that integral of the stimulus (or area, concentration × duration) controls the fraction of cells that activate NF-κB in the population. However, stimulus temporal profile determined NF-κB dynamics, cell-to-cell variability, and gene expression phenotype. A sustained, weak stimulation lead to heterogeneous activation and delayed timing that is transmitted to gene expression. In contrast, a transient, strong stimulus with the same area caused rapid and uniform dynamics. These results show that digital NF-κB signaling enables multidimensional control of cellular phenotype via input profile, allowing parallel and independent control of single-cell activation probability and population heterogeneity.

Spatiotemporal control of opioid signaling and behavior

PubMed Central

Siuda, Edward R.; Copits, Bryan A.; Schmidt, Martin J.; Baird, Madison A.; Al-Hasani, Ream; Planer, William J.; Funderburk, Samuel C.; McCall, Jordan G.; Gereau, Robert W.; Bruchas, Michael R.

2015-01-01

Summary Optogenetics is now a widely accepted tool for spatiotemporal manipulation of neuronal activity. However, a majority of optogenetic approaches use binary on/off control schemes. Here we extend the optogenetic toolset by developing a neuromodulatory approach using a rationale-based design to generate a Gi-coupled, optically-sensitive, mu-opioid-like receptor, we term opto-MOR. We demonstrate that opto-MOR engages canonical mu-opioid signaling through inhibition of adenylyl cyclase, activation of MAPK and G protein-gated inward rectifying potassium (GIRK) channels, and internalizes with similar kinetics as the mu-opioid receptor. To assess in vivo utility we expressed a Cre-dependent viral opto-MOR in RMTg/VTA GABAergic neurons, which led to a real-time place preference. In contrast, expression of opto-MOR in GABAergic neurons of the ventral pallidum hedonic cold spot, led to real-time place aversion. This tool has generalizable application for spatiotemporal control of opioid signaling and, furthermore, can be used broadly for mimicking endogenous neuronal inhibition pathways. PMID:25937173

Discovery of new candidate genes for rheumatoid arthritis through integration of genetic association data with expression pathway analysis.

PubMed

Shchetynsky, Klementy; Diaz-Gallo, Lina-Marcella; Folkersen, Lasse; Hensvold, Aase Haj; Catrina, Anca Irinel; Berg, Louise; Klareskog, Lars; Padyukov, Leonid

2017-02-02

Here we integrate verified signals from previous genetic association studies with gene expression and pathway analysis for discovery of new candidate genes and signaling networks, relevant for rheumatoid arthritis (RA). RNA-sequencing-(RNA-seq)-based expression analysis of 377 genes from previously verified RA-associated loci was performed in blood cells from 5 newly diagnosed, non-treated patients with RA, 7 patients with treated RA and 12 healthy controls. Differentially expressed genes sharing a similar expression pattern in treated and untreated RA sub-groups were selected for pathway analysis. A set of "connector" genes derived from pathway analysis was tested for differential expression in the initial discovery cohort and validated in blood cells from 73 patients with RA and in 35 healthy controls. There were 11 qualifying genes selected for pathway analysis and these were grouped into two evidence-based functional networks, containing 29 and 27 additional connector molecules. The expression of genes, corresponding to connector molecules was then tested in the initial RNA-seq data. Differences in the expression of ERBB2, TP53 and THOP1 were similar in both treated and non-treated patients with RA and an additional nine genes were differentially expressed in at least one group of patients compared to healthy controls. The ERBB2, TP53. THOP1 expression profile was successfully replicated in RNA-seq data from peripheral blood mononuclear cells from healthy controls and non-treated patients with RA, in an independent collection of samples. Integration of RNA-seq data with findings from association studies, and consequent pathway analysis implicate new candidate genes, ERBB2, TP53 and THOP1 in the pathogenesis of RA.

BRCA1 Mutation Status and Follicular Fluid Exposure Alters NFκB Signaling and ISGylation in Human Fallopian Tube Epithelial Cells.

PubMed

Hollingsworth, Julia; Lau, Angela; Tone, Alicia; Kollara, Alexandra; Allen, Lisa; Colgan, Terence J; Dube, Valerie; Rosen, Barry; Murphy, K Joan; Greenblatt, Ellen M; Feigenberg, Tomer; Virtanen, Carl; Brown, Theodore J

2018-05-28

Germline BRCA1 or BRCA2 mutations (mtBRCA1 and mtBRCA2) increase risk for high-grade serous ovarian cancer (HGSOC), the most commonly diagnosed epithelial ovarian cancer histotype. Other identified risk factors for this cancer, which originates primarily in the distal fallopian tube epithelium (FTE), implicate ovulation, during which the FTE cells become transiently exposed to follicular fluid (FF). To test whether mtBRCA1 or mtBRCA2 nonmalignant FTE cells respond differently to periovulatory FF exposure than control patient FTE cells, gene expression profiles from primary FTE cultures derived from BRCA1 or BRCA2 mutation carriers or control patients were compared at baseline, 24 hours after FF exposure, and 24 hours after FF replacement with culture medium. Hierarchical clustering revealed both FF exposure and BRCA mutation status affect gene expression, with BRCA1 mutation having the greatest impact. Gene set enrichment analysis revealed increased NFκB and EGFR signaling at baseline in mtBRCA1 samples, with increased interferon target gene expression, including members of the ISGylation pathway, observed after recovery from FF exposure. Gene set enrichment analysis did not identify altered pathway signaling in mtBRCA2 samples. An inverse relationship between EGFR signaling and ISGylation with BRCA1 protein levels was verified in an immortalized FTE cell line, OE-E6/E7, stably transfected with BRCA1 cDNA. Suppression of ISG15 and ISGylated protein levels by increased BRCA1 expression was found to be mediated by decreased NFκB signaling. These studies indicate that increased NFκB signaling associated with decreased BRCA1 expression results in increased ISG15 and protein ISGylation following FF exposure, which may be involved in predisposition to HGSOC. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Notch1-STAT3-ETBR signaling axis controls reactive astrocyte proliferation after brain injury.

PubMed

LeComte, Matthew D; Shimada, Issei S; Sherwin, Casey; Spees, Jeffrey L

2015-07-14

Defining the signaling network that controls reactive astrogliosis may provide novel treatment targets for patients with diverse CNS injuries and pathologies. We report that the radial glial cell antigen RC2 identifies the majority of proliferating glial fibrillary acidic protein-positive (GFAP(+)) reactive astrocytes after stroke. These cells highly expressed endothelin receptor type B (ETB(R)) and Jagged1, a Notch1 receptor ligand. To study signaling in adult reactive astrocytes, we developed a model based on reactive astrocyte-derived neural stem cells isolated from GFAP-CreER-Notch1 conditional knockout (cKO) mice. By loss- and gain-of-function studies and promoter activity assays, we found that Jagged1/Notch1 signaling increased ETB(R) expression indirectly by raising the level of phosphorylated signal transducer and activator of transcription 3 (STAT3), a previously unidentified EDNRB transcriptional activator. Similar to inducible transgenic GFAP-CreER-Notch1-cKO mice, GFAP-CreER-ETB(R)-cKO mice exhibited a defect in reactive astrocyte proliferation after cerebral ischemia. Our results indicate that the Notch1-STAT3-ETB(R) axis connects a signaling network that promotes reactive astrocyte proliferation after brain injury.

Notch1–STAT3–ETBR signaling axis controls reactive astrocyte proliferation after brain injury

PubMed Central

LeComte, Matthew D.; Shimada, Issei S.; Sherwin, Casey; Spees, Jeffrey L.

2015-01-01

Defining the signaling network that controls reactive astrogliosis may provide novel treatment targets for patients with diverse CNS injuries and pathologies. We report that the radial glial cell antigen RC2 identifies the majority of proliferating glial fibrillary acidic protein-positive (GFAP+) reactive astrocytes after stroke. These cells highly expressed endothelin receptor type B (ETBR) and Jagged1, a Notch1 receptor ligand. To study signaling in adult reactive astrocytes, we developed a model based on reactive astrocyte-derived neural stem cells isolated from GFAP-CreER-Notch1 conditional knockout (cKO) mice. By loss- and gain-of-function studies and promoter activity assays, we found that Jagged1/Notch1 signaling increased ETBR expression indirectly by raising the level of phosphorylated signal transducer and activator of transcription 3 (STAT3), a previously unidentified EDNRB transcriptional activator. Similar to inducible transgenic GFAP-CreER-Notch1-cKO mice, GFAP-CreER-ETBR-cKO mice exhibited a defect in reactive astrocyte proliferation after cerebral ischemia. Our results indicate that the Notch1–STAT3–ETBR axis connects a signaling network that promotes reactive astrocyte proliferation after brain injury. PMID:26124113

Neuropeptides: Developmental Signals in Placode Progenitor Formation

PubMed Central

Lleras-Forero, Laura; Tambalo, Monica; Christophorou, Nicolas; Chambers, David; Houart, Corinne; Streit, Andrea

2013-01-01

Summary Few families of signaling factors have been implicated in the control of development. Here, we identify the neuropeptides nociceptin and somatostatin, a neurotransmitter and neuroendocrine hormone, as a class of developmental signals in both chick and zebrafish. We show that signals from the anterior mesendoderm are required for the formation of anterior placode progenitors, with one of the signals being somatostatin. Somatostatin controls ectodermal expression of nociceptin, and both peptides regulate Pax6 in lens and olfactory progenitors. Consequently, loss of somatostatin and nociceptin signaling leads to severe reduction of lens formation. Our findings not only uncover these neuropeptides as developmental signals but also identify a long-sought-after mechanism that initiates Pax6 in placode progenitors and may explain the ancient evolutionary origin of neuropeptides, predating a complex nervous system. PMID:23906067

ERK signaling pathway regulates sleep duration through activity-induced gene expression during wakefulness.

PubMed

Mikhail, Cyril; Vaucher, Angélique; Jimenez, Sonia; Tafti, Mehdi

2017-01-24

Wakefulness is accompanied by experience-dependent synaptic plasticity and an increase in activity-regulated gene transcription. Wake-induced genes are certainly markers of neuronal activity and may also directly regulate the duration of and need for sleep. We stimulated murine cortical cultures with the neuromodulatory signals that are known to control wakefulness in the brain and found that norepinephrine alone or a mixture of these neuromodulators induced activity-regulated gene transcription. Pharmacological inhibition of the various signaling pathways involved in the regulation of gene expression indicated that the extracellular signal-regulated kinase (ERK) pathway is the principal one mediating the effects of waking neuromodulators on gene expression. In mice, ERK phosphorylation in the cortex increased and decreased with wakefulness and sleep. Whole-body or cortical neuron-specific deletion of Erk1 or Erk2 significantly increased the duration of wakefulness in mice, and pharmacological inhibition of ERK phosphorylation decreased sleep duration and increased the duration of wakefulness bouts. Thus, this signaling pathway, which is highly conserved from Drosophila to mammals, is a key pathway that links waking experience-induced neuronal gene expression to sleep duration and quality. Copyright © 2017, American Association for the Advancement of Science.

Hedgehog participates in the establishment of left-right asymmetry during amphioxus development by controlling Cerberus expression.

PubMed

Hu, Guangwei; Li, Guang; Wang, Hui; Wang, Yiquan

2017-12-15

Correct patterning of left-right (LR) asymmetry is essential during the embryonic development of bilaterians. Hedgehog (Hh) signaling is known to play a role in LR asymmetry development of mouse, chicken and sea urchin embryos by regulating Nodal expression. In this study, we report a novel regulatory mechanism for Hh in LR asymmetry development of amphioxus embryos. Our results revealed that Hh -/- embryos abolish Cerberus ( Cer ) transcription, with bilaterally symmetric expression of Nodal , Lefty and Pitx In consequence, Hh -/- mutants duplicated left-side structures and lost right-side characters, displaying an abnormal bilaterally symmetric body plan. These LR defects in morphology and gene expression could be rescued by Hh mRNA injection. Our results indicate that Hh participates in amphioxus LR patterning by controlling Cer gene expression. Curiously, however, upregulation of Hh signaling failed to alter the Cer expression pattern or LR morphology in amphioxus embryos, indicating that Hh might not provide an asymmetric cue for Cer expression. In addition, Hh is required for mouth opening in amphioxus, hinting at a homologous relationship between amphioxus and vertebrate mouth development. © 2017. Published by The Company of Biologists Ltd.

Glucocorticoid and cytokine crosstalk: Feedback, feedforward, and co-regulatory interactions determine repression or resistance

PubMed Central

Shah, Suharsh; Altonsy, Mohammed O.; Gerber, Antony N.

2017-01-01

Inflammatory signals induce feedback and feedforward systems that provide temporal control. Although glucocorticoids can repress inflammatory gene expression, glucocorticoid receptor recruitment increases expression of negative feedback and feedforward regulators, including the phosphatase, DUSP1, the ubiquitin-modifying enzyme, TNFAIP3, or the mRNA-destabilizing protein, ZFP36. Moreover, glucocorticoid receptor cooperativity with factors, including nuclear factor-κB (NF-κB), may enhance regulator expression to promote repression. Conversely, MAPKs, which are inhibited by glucocorticoids, provide feedforward control to limit expression of the transcription factor IRF1, and the chemokine, CXCL10. We propose that modulation of feedback and feedforward control can determine repression or resistance of inflammatory gene expression toglucocorticoid. PMID:28283576

Type I γ Phosphatidylinositol Phosphate 5-Kinase i5 Controls the Ubiquitination and Degradation of the Tumor Suppressor Mitogen-inducible Gene 6*

PubMed Central

Sun, Ming; Cai, Jinyang; Anderson, Richard A.; Sun, Yue

2016-01-01

Mitogen-inducible gene 6 (Mig6) is a tumor suppressor, and the disruption of Mig6 expression is associated with cancer development. Mig6 directly interacts with epidermal growth factor receptor (EGFR) to suppress the activation and downstream signaling of EGFR. Therefore, loss of Mig6 enhances EGFR-mediated signaling and promotes EGFR-dependent carcinogenesis. The molecular mechanism modulating Mig6 expression in cancer remains unclear. Here we demonstrate that type I γ phosphatidylinositol phosphate 5-kinase i5 (PIPKIγi5), an enzyme producing phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2), stabilizes Mig6 expression. Knockdown of PIPKIγi5 leads to the loss of Mig6 expression, which dramatically enhances and prolongs EGFR-mediated cell signaling. Loss of PIPKIγi5 significantly promotes Mig6 protein degradation via proteasomes, but it does not affect the Mig6 mRNA level. PIPKIγi5 directly interacts with the E3 ubiquitin ligase neuronal precursor cell-expressed developmentally down-regulated 4-1 (NEDD4-1). The C-terminal domain of PIPKIγi5 and the WW1 and WW2 domains of NEDD4-1 are required for their interaction. The C2 domain of NEDD4-1 is required for its interaction with PtdIns(4,5)P2. By binding with NEDD4-1 and producing PtdIns(4,5)P2, PIPKIγi5 perturbs NEDD4-1-mediated Mig6 ubiquitination and the subsequent proteasomal degradation. Thus, loss of NEDD4-1 can rescue Mig6 expression in PIPKIγi5 knockdown cells. In this way, PIPKIγi5, NEDD4-1, and Mig6 form a novel molecular nexus that controls EGFR activation and downstream signaling. PMID:27557663

Extracellular Calcium Has Multiple Targets to Control Cell Proliferation.

PubMed

Capiod, Thierry

2016-01-01

Calcium channels and the two G-protein coupled receptors sensing extracellular calcium, calcium-sensing receptor (CaSR) and GPRC6a, are the two main means by which extracellular calcium can signal to cells and regulate many cellular processes including cell proliferation, migration and invasion of tumoral cells. Many intracellular signaling pathways are sensitive to cytosolic calcium rises and conversely intracellular signaling pathways can modulate calcium channel expression and activity. Calcium channels are undoubtedly involved in the former while the CaSR and GPRC6a are most likely to interfere with the latter. As for neurotransmitters, calcium ions use plasma membrane channels and GPCR to trigger cytosolic free calcium concentration rises and intracellular signaling and regulatory pathways activation. Calcium sensing GPCR, CaSR and GPRC6a, allow a supplemental degree of control and as for metabotropic receptors, they not only modulate calcium channel expression but they may also control calcium-dependent K+ channels. The multiplicity of intracellular signaling pathways involved, their sensitivity to local and global intracellular calcium increase and to CaSR and GPRC6a stimulation, the presence of membrane signalplex, all this confers the cells the plasticity they need to convert the effects of extracellular calcium into complex physiological responses and therefore determine their fate.

Constitutive Activity among Orphan Class-A G Protein Coupled Receptors.

PubMed

Martin, Adam L; Steurer, Michael A; Aronstam, Robert S

2015-01-01

The purpose of this study was to evaluate the extent of constitutive activity among orphan class-A G protein coupled receptors within the cAMP signaling pathway. Constitutive signaling was revealed by changes in gene expression under control of the cAMP response element. Gene expression was measured in Chinese hamster ovary cells transiently co-transfected with plasmids containing a luciferase reporter and orphan receptor. Criteria adopted for defining constitutive activation were: 1) 200% elevation over baseline reporter gene expression; 2) 40% inhibition of baseline expression; and 3) 40% inhibition of expression stimulated by 3 μM forskolin. Five patterns of activity were noted: 1) inhibition under both baseline and forskolin stimulated expression (GPR15, GPR17, GPR18, GPR20, GPR25, GPR27, GPR31, GPR32, GPR45, GPR57, GPR68, GPR83, GPR84, GPR132, GPR150, GPR176); 2) no effect on baseline expression, but inhibition of forskolin stimulated expression (GPR4, GPR26, GPR61, GPR62, GPR78, GPR101, GPR119); 3) elevation of baseline signaling coupled with inhibition of forskolin stimulated expression (GPR6, GPR12); 4) elevation of baseline signaling without inhibition of forskolin stimulated expression (GPR3, GPR21, GPR52, GPR65); and 5) no effect on expression (GPR1, GPR19, GPR22, GPR34, GPR35, GPR39, GPR63, GPR82, GPR85, GPR87). Constitutive activity was observed in 75% of the orphan class-A receptors examined (30 of 40). This constitutive signaling cannot be explained by simple overexpression of the receptor. Inhibition of cAMP mediated expression was far more common (65%) than stimulation of expression (15%). Orphan receptors that were closely related based on amino acid homology tended to have similar effects on gene expression. These results suggest that identification of inverse agonists may be a fruitful approach for categorizing these orphan receptors and targeting them for pharmacological intervention.

Constitutive Activity among Orphan Class-A G Protein Coupled Receptors

PubMed Central

Martin, Adam L.; Steurer, Michael A.; Aronstam, Robert S.

2015-01-01

The purpose of this study was to evaluate the extent of constitutive activity among orphan class-A G protein coupled receptors within the cAMP signaling pathway. Constitutive signaling was revealed by changes in gene expression under control of the cAMP response element. Gene expression was measured in Chinese hamster ovary cells transiently co-transfected with plasmids containing a luciferase reporter and orphan receptor. Criteria adopted for defining constitutive activation were: 1) 200% elevation over baseline reporter gene expression; 2) 40% inhibition of baseline expression; and 3) 40% inhibition of expression stimulated by 3 μM forskolin. Five patterns of activity were noted: 1) inhibition under both baseline and forskolin stimulated expression (GPR15, GPR17, GPR18, GPR20, GPR25, GPR27, GPR31, GPR32, GPR45, GPR57, GPR68, GPR83, GPR84, GPR132, GPR150, GPR176); 2) no effect on baseline expression, but inhibition of forskolin stimulated expression (GPR4, GPR26, GPR61, GPR62, GPR78, GPR101, GPR119); 3) elevation of baseline signaling coupled with inhibition of forskolin stimulated expression (GPR6, GPR12); 4) elevation of baseline signaling without inhibition of forskolin stimulated expression (GPR3, GPR21, GPR52, GPR65); and 5) no effect on expression (GPR1, GPR19, GPR22, GPR34, GPR35, GPR39, GPR63, GPR82, GPR85, GPR87). Constitutive activity was observed in 75% of the orphan class-A receptors examined (30 of 40). This constitutive signaling cannot be explained by simple overexpression of the receptor. Inhibition of cAMP mediated expression was far more common (65%) than stimulation of expression (15%). Orphan receptors that were closely related based on amino acid homology tended to have similar effects on gene expression. These results suggest that identification of inverse agonists may be a fruitful approach for categorizing these orphan receptors and targeting them for pharmacological intervention. PMID:26384023

[Endoplasmic reticulum stress in INS-1-3 cell associated with the expression changes of MODY gene pathway].

PubMed

Liu, Y T; Li, S R; Wang, Z; Xiao, J Z

2016-09-13

Objective: To profile the gene expression changes associated with endoplasmic reticulum stress in INS-1-3 cells induced by thapsigargin (TG) and tunicamycin (TM). Methods: Normal cultured INS-1-3 cells were used as a control. TG and TM were used to induce endoplasmic reticulum stress in INS-1-3 cells. Digital gene expression profiling technique was used to detect differentially expressed gene. The changes of gene expression were detected by expression pattern clustering analysis, gene ontology (GO) function and pathway enrichment analysis. Real time polymerase chain reaction (RT-PCR) was used to verify the key changes of gene expression. Results: Compared with the control group, there were 57 (45 up-regulated, 12 down-regulated) and 135 (99 up-regulated, 36 down-regulated) differentially expressed genes in TG and TM group, respectively. GO function enrichment analyses indicated that the main enrichment was in the endoplasmic reticulum. In signaling pathway analysis, the identified pathways were related with endoplasmic reticulum stress, antigen processing and presentation, protein export, and most of all, the maturity onset diabetes of the young (MODY) pathway. Conclusion: Under the condition of endoplasmic reticulum stress, the related expression changes of transcriptional factors in MODY signaling pathway may be related with the impaired function in islet beta cells.

Notch signalling in cardiovasculogenesis: insight into their role in early cardiovascular development.

PubMed

Saravanakumar, Marimuthu; Devaraj, Halagowder

2013-05-01

The role of Notch signalling in congenital cardiovascular disease is evident by the identification of human mutations in several Notch signalling components, which also indicates the importance of activated Notch pathway in cardiovascular biology. Therefore, the aim of the present study is to investigate the expression pattern of the components of Notch signalling molecules and their role in mice embryonic heart and vascular development. Group A: normal control pregnant mice, group B: pregnant mice were injected with DMSO, group C: DAPT were subcutaneously injected to pregnant mice. The morphological and molecular changes of trabeculation-defective phenotype were analysed using histological, scanning electron microscope, immunoblot, immunolocalization and reverse transcriptase-PCR. E15.5 DAPT-treated mice revealed that there was a major reduction in the formation of septal walls between the ventricular chambers compared with normal control pregnant mice. VEGF expression was found in the DAPT treated and wild-type embryonic artery, whereas notch target genes GATA4, Hey1 expression were not found in the DAPT treated mice embryo. The role of Notch in ventricular development is supported by the trabeculation-defective phenotype seen in standard and endocardial-specific inhibition of Notch targets. The present study reveals the significant role of Notch signalling during the formation of ventricular septum and proper development of endothelial cell lineage and its precursor in mice cardiogenesis.

BMP signaling and podocyte markers are decreased in human diabetic nephropathy in association with CTGF overexpression.

PubMed

Turk, Tamara; Leeuwis, Jan Willem; Gray, Julia; Torti, Suzy V; Lyons, Karen M; Nguyen, Tri Q; Goldschmeding, Roel

2009-07-01

Diabetic nephropathy is characterized by decreased expression of bone morphogenetic protein-7 (BMP-7) and decreased podocyte number and differentiation. Extracellular antagonists such as connective tissue growth factor (CTGF; CCN-2) and sclerostin domain-containing-1 (SOSTDC1; USAG-1) are important determinants of BMP signaling activity in glomeruli. We studied BMP signaling activity in glomeruli from diabetic patients and non-diabetic individuals and from control and diabetic CTGF(+/+) and CTGF(+/-) mice. BMP signaling activity was visualized by phosphorylated Smad1, -5, and -8 (pSmad1/5/8) immunostaining, and related to expression of CTGF, SOSTDC1, and the podocyte differentiation markers WT1, synaptopodin, and nephrin. In control and diabetic glomeruli, pSmad1/5/8 was mainly localized in podocytes, but both number of positive cells and staining intensity were decreased in diabetes. Nephrin and synaptopodin were decreased in diabetic glomeruli. Decrease of pSmad1/5/8 was only partially explained by decrease in podocyte number. SOSTDC1 and CTGF were expressed exclusively in podocytes. In diabetic glomeruli, SOSTDC1 decreased in parallel with podocyte number, whereas CTGF was strongly increased. In diabetic CTGF(+/-) mice, pSmad1/5/8 was preserved, compared with diabetic CTGF(+/+) mice. In conclusion, in human diabetic nephropathy, BMP signaling activity is diminished, together with reduction of podocyte markers. This might relate to concomitant overexpression of CTGF but not SOSTDC1.

Receptors and Other Signaling Proteins Required for Serotonin Control of Locomotion in Caenorhabditis elegans

PubMed Central

Gürel, Güliz; Gustafson, Megan A.; Pepper, Judy S.; Horvitz, H. Robert; Koelle, Michael R.

2012-01-01

A better understanding of the molecular mechanisms of signaling by the neurotransmitter serotonin is required to assess the hypothesis that defects in serotonin signaling underlie depression in humans. Caenorhabditis elegans uses serotonin as a neurotransmitter to regulate locomotion, providing a genetic system to analyze serotonin signaling. From large-scale genetic screens we identified 36 mutants of C. elegans in which serotonin fails to have its normal effect of slowing locomotion, and we molecularly identified eight genes affected by 19 of the mutations. Two of the genes encode the serotonin-gated ion channel MOD-1 and the G-protein-coupled serotonin receptor SER-4. mod-1 is expressed in the neurons and muscles that directly control locomotion, while ser-4 is expressed in an almost entirely non-overlapping set of sensory and interneurons. The cells expressing the two receptors are largely not direct postsynaptic targets of serotonergic neurons. We analyzed animals lacking or overexpressing the receptors in various combinations using several assays for serotonin response. We found that the two receptors act in parallel to affect locomotion. Our results show that serotonin functions as an extrasynaptic signal that independently activates multiple receptors at a distance from its release sites and identify at least six additional proteins that appear to act with serotonin receptors to mediate serotonin response. PMID:23023001

Translational Regulation in Nutrigenomics12

PubMed Central

Liu, Botao; Qian, Shu-Bing

2011-01-01

The emergence of genome-wide analysis to interrogate cellular DNA, RNA, and protein content has revolutionized the study of the control network that mediates cellular homeostasis. Nutrigenomics addresses the effect of nutrients on gene expression, which provides a basis for understanding the biological activity of dietary components. Translation of mRNAs represents the last step of genetic flow and primarily defines the proteome. Translational regulation is thus critical for gene expression, in particular, under nutrient excess or deficiency. Until recently, it was unclear how the global effects of translational control are influenced by nutrient signaling. An emerging concept of translational reprogramming addresses how to maintain the expression of specific proteins during pathophysiological conditions by translation of selective mRNAs. Here we describe recent advances in our understanding of translational control, nutrient signaling, and their dysregulation in aging and cancer. The mechanistic understanding of translational regulation in response to different nutrient conditions may help identify potential dietary and therapeutic targets to improve human health. PMID:22332093

Application of Gene Expression Trajectories Initiated from ErbB Receptor Activation Highlights the Dynamics of Divergent Promoter Usage.

PubMed

Carbajo, Daniel; Magi, Shigeyuki; Itoh, Masayoshi; Kawaji, Hideya; Lassmann, Timo; Arner, Erik; Forrest, Alistair R R; Carninci, Piero; Hayashizaki, Yoshihide; Daub, Carsten O; Okada-Hatakeyama, Mariko; Mar, Jessica C

2015-01-01

Understanding how cells use complex transcriptional programs to alter their fate in response to specific stimuli is an important question in biology. For the MCF-7 human breast cancer cell line, we applied gene expression trajectory models to identify the genes involved in driving cell fate transitions. We modified trajectory models to account for the scenario where cells were exposed to different stimuli, in this case epidermal growth factor and heregulin, to arrive at different cell fates, i.e. proliferation and differentiation respectively. Using genome-wide CAGE time series data collected from the FANTOM5 consortium, we identified the sets of promoters that were involved in the transition of MCF-7 cells to their specific fates versus those with expression changes that were generic to both stimuli. Of the 1,552 promoters identified, 1,091 had stimulus-specific expression while 461 promoters had generic expression profiles over the time course surveyed. Many of these stimulus-specific promoters mapped to key regulators of the ERK (extracellular signal-regulated kinases) signaling pathway such as FHL2 (four and a half LIM domains 2). We observed that in general, generic promoters peaked in their expression early on in the time course, while stimulus-specific promoters tended to show activation of their expression at a later stage. The genes that mapped to stimulus-specific promoters were enriched for pathways that control focal adhesion, p53 signaling and MAPK signaling while generic promoters were enriched for cell death, transcription and the cell cycle. We identified 162 genes that were controlled by an alternative promoter during the time course where a subset of 37 genes had separate promoters that were classified as stimulus-specific and generic. The results of our study highlighted the degree of complexity involved in regulating a cell fate transition where multiple promoters mapping to the same gene can demonstrate quite divergent expression profiles.

Suppression of mTOR signaling pathway promotes bone marrow mesenchymal stem cells differentiation into osteoblast in degenerative scoliosis: in vivo and in vitro.

PubMed

Wang, Yu; Yi, Xiao-Dong; Li, Chun-De

2017-02-01

To investigate the role of mTOR signaling pathway in bone marrow mesenchymal stem cells (BMSCs) differentiation into osteoblast in degenerative scoliosis (DS). The rat model of DS was established. Thirty-two Sprague-Dawley (SD) rats were selected and divided into the normal control group, the positive control group (normal rats injected with rapamycin), the negative control group (DS rats injected with PBS) and the experiment group (DS rats injected with rapamycin). H&E staining was performed to observe the osteogenesis of scoliosis. The BMSCs were obtained and assigned into seven groups: the normal control group, the positive control group, the negative control group and 1.0/10.0/100.0/1000.0 nmol/L experiment groups. Flow cytometry was conducted to testify cell cycle. The mRNA and protein expressions of mTOR and osteoblastic differentiation markers were measured by qRT-PCR and western blotting. In vivo, compared with the negative control group, bone trabecular area and the number of differentiated bone cells were significantly increased in the experiment groups. In vitro, at 24 and 48 h after rapamycin treatment, compared with the negative control group, BMSCs at G0/G1 stage increased, but BMSCs at S stage decreased in the 1.0/10.0/100.0/1000.0 nmol/L experiment groups; the expressions of mTOR and p70-S6K1 proteins were reduced in the 1.0/10.0/100.0/1000.0 nmol/L experiment groups, while ALP activity, OC levels, calcium deposition, Co1-I protein expression and the mRNA expressions of OC and Co1-I were significantly increased. Suppression of mTOR signaling pathway by rapamycin could promote BMSCs differentiation into osteoblast in DS.

PTEN and PI-3 kinase inhibitors control LPS signaling and the lymphoproliferative response in the CD19+ B cell compartment

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

Singh, Alok R.; Peirce, Susan K.; Joshi, Shweta

Pattern recognition receptors (PRRs), e.g. toll receptors (TLRs) that bind ligands within the microbiome have been implicated in the pathogenesis of cancer. LPS is a ligand for two TLR family members, TLR4 and RP105 which mediate LPS signaling in B cell proliferation and migration. Although LPS/TLR/RP105 signaling is well-studied; our understanding of the underlying molecular mechanisms controlling these PRR signaling pathways remains incomplete. Previous studies have demonstrated a role for PTEN/PI-3K signaling in B cell selection and survival, however a role for PTEN/PI-3K in TLR4/RP105/LPS signaling in the B cell compartment has not been reported. Herein, we crossed a CD19cremore » and PTEN{sup fl/fl} mouse to generate a conditional PTEN knockout mouse in the CD19+ B cell compartment. These mice were further crossed with an IL-14α transgenic mouse to study the combined effect of PTEN deletion, PI-3K inhibition and expression of IL-14α (a cytokine originally identified as a B cell growth factor) in CD19+ B cell lymphoproliferation and response to LPS stimulation. Targeted deletion of PTEN and directed expression of IL-14α in the CD19+ B cell compartment (IL-14+PTEN-/-) lead to marked splenomegaly and altered spleen morphology at baseline due to expansion of marginal zone B cells, a phenotype that was exaggerated by treatment with the B cell mitogen and TLR4/RP105 ligand, LPS. Moreover, LPS stimulation of CD19+ cells isolated from these mice display increased proliferation, augmented AKT and NFκB activation as well as increased expression of c-myc and cyclinD1. Interestingly, treatment of LPS treated IL-14+PTEN-/- mice with a pan PI-3K inhibitor, SF1126, reduced splenomegaly, cell proliferation, c-myc and cyclin D1 expression in the CD19+ B cell compartment and normalized the splenic histopathologic architecture. These findings provide the direct evidence that PTEN and PI-3K inhibitors control TLR4/RP105/LPS signaling in the CD19+ B cell compartment and that pan PI-3 kinase inhibitors reverse the lymphoproliferative phenotype in vivo. - Highlights: • First genetic evidence that PTEN controls LPS/TLR4 signaling in B lymphocytes. • Evidence that PTEN regulates LPS induced lymphoproliferation in vivo. • PI-3 kinase inhibitors block LPS induced lymphoproliferation in vivo.« less

Ectopic Expression of Xylella fastidiosa rpfF Conferring Production of Diffusible Signal Factor in Transgenic Tobacco and Citrus Alters Pathogen Behavior and Reduces Disease Severity.

PubMed

Caserta, R; Souza-Neto, R R; Takita, M A; Lindow, S E; De Souza, A A

2017-11-01

The pathogenicity of Xylella fastidiosa is associated with its ability to colonize the xylem of host plants. Expression of genes contributing to xylem colonization are suppressed, while those necessary for insect vector acquisition are increased with increasing concentrations of diffusible signal factor (DSF), whose production is dependent on RpfF. We previously demonstrated that transgenic citrus plants ectopically expressing rpfF from a citrus strain of X. fastidiosa subsp. pauca exhibited less susceptibility to Xanthomonas citri subsp. citri, another pathogen whose virulence is modulated by DSF accumulation. Here, we demonstrate that ectopic expression of rpfF in both transgenic tobacco and sweet orange also confers a reduction in disease severity incited by X. fastidiosa and reduces its colonization of those plants. Decreased disease severity in the transgenic plants was generally associated with increased expression of genes conferring adhesiveness to the pathogen and decreased expression of genes necessary for active motility, accounting for the reduced population sizes achieved in the plants, apparently by limiting pathogen dispersal through the plant. Plant-derived DSF signal molecules in a host plant can, therefore, be exploited to interfere with more than one pathogen whose virulence is controlled by DSF signaling.

Mitochondrial Energy and Redox Signaling in Plants

PubMed Central

Schwarzländer, Markus

2013-01-01

Abstract Significance: For a plant to grow and develop, energy and appropriate building blocks are a fundamental requirement. Mitochondrial respiration is a vital source for both. The delicate redox processes that make up respiration are affected by the plant's changing environment. Therefore, mitochondrial regulation is critically important to maintain cellular homeostasis. This involves sensing signals from changes in mitochondrial physiology, transducing this information, and mounting tailored responses, by either adjusting mitochondrial and cellular functions directly or reprogramming gene expression. Recent Advances: Retrograde (RTG) signaling, by which mitochondrial signals control nuclear gene expression, has been a field of very active research in recent years. Nevertheless, no mitochondrial RTG-signaling pathway is yet understood in plants. This review summarizes recent advances toward elucidating redox processes and other bioenergetic factors as a part of RTG signaling of plant mitochondria. Critical Issues: Novel insights into mitochondrial physiology and redox-regulation provide a framework of upstream signaling. On the other end, downstream responses to modified mitochondrial function have become available, including transcriptomic data and mitochondrial phenotypes, revealing processes in the plant that are under mitochondrial control. Future Directions: Drawing parallels to chloroplast signaling and mitochondrial signaling in animal systems allows to bridge gaps in the current understanding and to deduce promising directions for future research. It is proposed that targeted usage of new technical approaches, such as quantitative in vivo imaging, will provide novel leverage to the dissection of plant mitochondrial signaling. Antioxid. Redox Signal. 18, 2122–2144. PMID:23234467

Nitric oxide mediates antimicrobial peptide gene expression by activating eicosanoid signaling

PubMed Central

Sadekuzzaman, Md.

2018-01-01

Nitric oxide (NO) mediates both cellular and humoral immune responses in insects. Its mediation of cellular immune responses uses eicosanoids as a downstream signal. However, the cross-talk with two immune mediators was not known in humoral immune responses. This study focuses on cross-talk between two immune mediators in inducing gene expression of anti-microbial peptides (AMPs) of a lepidopteran insect, Spodoptera exigua. Up-regulation of eight AMPs was observed in S. exigua against bacterial challenge. However, the AMP induction was suppressed by injection of an NO synthase inhibitor, L-NAME, while little expressional change was observed on injecting its enantiomer, D-NAME. The functional association between NO biosynthesis and AMP gene expression was further supported by RNA interference (RNAi) against NO synthase (SeNOS), which suppressed AMP gene expression under the immune challenge. The AMP induction was also mimicked by NO alone because injecting an NO analog, SNAP, without bacterial challenge significantly induced the AMP gene expression. Interestingly, an eicosanoid biosynthesis inhibitor, dexamethasone (DEX), suppressed the NO induction of AMP expression. The inhibitory activity of DEX was reversed by the addition of arachidonic acid, a precursor of eicosanoid biosynthesis. AMP expression of S. exigua was also controlled by the Toll/IMD signal pathway. The RNAi of Toll receptors or Relish suppressed AMP gene expression by suppressing NO levels and subsequently reducing PLA2 enzyme activity. These results suggest that eicosanoids are a downstream signal of NO mediation of AMP expression against bacterial challenge. PMID:29466449

Alterations in NMDA receptor expression during retinal degeneration in the RCS rat.

PubMed

Gründer, T; Kohler, K; Guenther, E

2001-01-01

To determine how a progressive loss of photoreceptor cells and the concomitant loss of glutamatergic input to second-order neurons can affect inner-retinal signaling, glutamate receptor expression was analyzed in the Royal College of Surgeons (RCS) rat, an animal model of retinitis pigmentosa. Immunohistochemistry was performed on retinal sections of RCS rats and congenic controls between postnatal (P) day 3 and the aged adult (up to P350) using specific antibodies against N-methyl-D-aspartate (NMDA) subunits. All NMDA subunits (NR1, NR2A-2D) were expressed in control and dystrophic retinas at all ages, and distinct patterns of labeling were found in horizontal cells, subpopulations of amacrine cells and ganglion cells, as well as in the outer and inner plexiform layer (IPL). NRI immunoreactivity in the inner plexiform layer of adult control retinas was concentrated in two distinct bands, indicating a synaptic localization of NMDA receptors in the OFF and ON signal pathways. In the RCS retina, these bands of NRI immunoreactivity in the IPL were much weaker in animals older than P40. In parallel, NR2B immunoreactivity in the outer plexiform layer (OPL) of RCS rats was always reduced compared to controls and vanished between P40 and P120. The most striking alteration observed in the degenerating retina, however, was a strong expression of NRI immunoreactivity in Müller cell processes in the inner retina which was not observed in control animals and which was present prior to any visible sign of photoreceptor degeneration. The results suggest functional changes in glutamatergic receptor signaling in the dystrophic retina and a possible involvement of Müller cells in early processes of this disease.

Cutting edge: A transcriptional repressor and corepressor induced by the STAT3-regulated anti-inflammatory signaling pathway.

PubMed

El Kasmi, Karim C; Smith, Amber M; Williams, Lynn; Neale, Geoffrey; Panopoulos, Athanasia D; Panopolous, Athanasia; Watowich, Stephanie S; Häcker, Hans; Foxwell, Brian M J; Murray, Peter J

2007-12-01

IL-10 regulates anti-inflammatory signaling via the activation of STAT3, which in turn controls the induction of a gene expression program whose products execute inhibitory effects on proinflammatory mediator production. In this study we show that IL-10 induces the expression of an ETS family transcriptional repressor, ETV3, and a helicase family corepressor, Strawberry notch homologue 2 (SBNO2), in mouse and human macrophages. IL-10-mediated induction of ETV3 and SBNO2 expression was dependent upon both STAT3 and a stimulus through the TLR pathway. We also observed that ETV3 expression was strongly induced by the STAT3 pathway regulated by IL-10 but not by STAT3 signaling activated by IL-6, which cannot activate the anti-inflammatory signaling pathway. ETV3 and SBNO2 repressed NF-kappaB- but not IFN regulatory factor 7 (IRF7)-activated transcriptional reporters. Collectively our data suggest that ETV3 and SBNO2 are components of the pathways that contribute to the downstream anti-inflammatory effects of IL-10.

Elevated ATF4 Expression, in the Absence of Other Signals, Is Sufficient for Transcriptional Induction via CCAAT Enhancer-binding Protein-activating Transcription Factor Response Elements*

PubMed Central

Shan, Jixiu; Örd, Daima; Örd, Tõnis; Kilberg, Michael S.

2009-01-01

Protein limitation in vivo or amino acid deprivation of cells in culture causes a signal transduction cascade consisting of activation of the kinase GCN2 (general control nonderepressible 2), phosphorylation of eukaryotic initiation factor 2, and increased synthesis of activating transcription factor (ATF) 4 by a translational control mechanism. In a self-limiting transcriptional program, ATF4 transiently activates a wide range of downstream target genes involved in transport, cellular metabolism, and other cell functions. Simultaneous activation of other signal transduction pathways by amino acid deprivation led to the question of whether or not the increased abundance of ATF4 alone was sufficient to trigger the transcriptional control mechanisms. Using 293 cells that ectopically express ATF4 in a tetracycline-inducible manner showed that ATF4 target genes were activated in the absence of amino acid deprivation. Ectopic expression of ATF4 alone resulted in effective recruitment of the general transcription machinery, but some reduction in histone modification was observed. These data document that ATF4 alone is sufficient to trigger the amino acid-responsive transcriptional control program. However, the absolute amount of ectopic ATF4 required to achieve the same degree of transcriptional activation observed after amino acid limitation was greater, suggesting that other factors may serve to enhance ATF4 function. PMID:19509279

Disruption of the bone morphogenetic protein receptor 2 pathway in nitrofen-induced congenital diaphragmatic hernia.

PubMed

Gosemann, Jan-Hendrik; Friedmacher, Florian; Fujiwara, Naho; Alvarez, Luis A J; Corcionivoschi, Nicolae; Puri, Prem

2013-08-01

Congenital diaphragmatic hernia (CDH) remains a major therapeutic challenge despite advances in neonatal resuscitation and intensive care. The high mortality and morbidity in CDH has been attributed to pulmonary hypoplasia and persistent pulmonary hypertension (PH). Bone morphogenetic protein receptor 2 (BMPR2) plays a key role in pulmonary vasculogenesis during the late stages of fetal lung development. BMPR2 is essential for control of endothelial and smooth muscle cell proliferation. Dysfunction of BMPR2 and downstream signaling have been shown to disturb the crucial balance of proliferation of smooth muscle cells contributing to the pathogenesis of human and experimental PH. We designed this study to investigate the hypothesis that BMPR2 signaling is disrupted in nitrofen-induced CDH. Pregnant rats were treated with nitrofen or vehicle on gestational day 9 (D9). Fetuses were sacrificed on D21 and divided into CDH and control. Quantitative real-time polymerase chain reaction, Western blotting, and confocal-immunofluorescence were performed to determine pulmonary gene expression levels and protein expression of BMPR2 and related proteins. Pulmonary Bmpr2 gene expression levels were significantly decreased in nitrofen-induced CDH compared to controls. Western blotting and confocal microscopy revealed decreased pulmonary BMPR2 protein expression and increased activation of p38(MAPK) in CDH compared to controls. The observed disruption of the BMPR2 signaling pathway may lead to extensive vascular remodeling and contribute to PH in the nitrofen-induced CDH model. BMPR2 may therefore represent a potential target for the treatment of PH in CDH. © 2013 Wiley Periodicals, Inc.

Programmed Death-1 Inhibition of Phosphatidylinositol 3-Kinase/AKT/Mechanistic Target of Rapamycin Signaling Impairs Sarcoidosis CD4+ T Cell Proliferation.

PubMed

Celada, Lindsay J; Rotsinger, Joseph E; Young, Anjuli; Shaginurova, Guzel; Shelton, Debresha; Hawkins, Charlene; Drake, Wonder P

2017-01-01

Patients with progressive sarcoidosis exhibit increased expression of programmed death-1 (PD-1) receptor on their CD4 + T cells. Up-regulation of this marker of T cell exhaustion is associated with a reduction in the proliferative response to T cell receptor (TCR) stimulation, a defect that is reversed by PD-1 pathway blockade. Genome-wide association studies and microarray analyses have correlated signaling downstream from the TCR with sarcoidosis disease severity, but the mechanism is not yet known. Reduced phosphatidylinositol 3-kinase (PI3K)/AKT expression inhibits proliferation by inhibiting cell cycle progression. To test the hypothesis that PD-1 expression attenuates TCR-dependent activation of PI3K/AKT activity in progressive systemic sarcoidosis, we analyzed PI3K/AKT/mechanistic target of rapamycin (mTOR) expression at baseline and after PD-1 pathway blockade in CD4 + T cells isolated from patients with sarcoidosis and healthy control subjects. We confirmed an increased percentage of PD-1 + CD4 + T cells and reduced proliferative capacity in patients with sarcoidosis compared with healthy control subjects (P < 0.001). There was a negative correlation with PD-1 expression and proliferative capacity (r = -0.70, P < 0.001). Expression of key mediators of cell cycle progression, including PI3K and AKT, were significantly decreased. Gene and protein expression levels reverted to healthy control levels after PD-1 pathway blockade. Reduction in sarcoidosis CD4 + T cell proliferative capacity is secondary to altered expression of key mediators of cell cycle progression, including the PI3K/AKT/mTOR pathway, via PD-1 up-regulation. This supports the concept that PD-1 up-regulation drives the immunologic deficits associated with sarcoidosis severity by inducing signaling aberrancies in key mediators of cell cycle progression.

Programmed Death-1 Inhibition of Phosphatidylinositol 3-Kinase/AKT/Mechanistic Target of Rapamycin Signaling Impairs Sarcoidosis CD4+ T Cell Proliferation

PubMed Central

Celada, Lindsay J.; Rotsinger, Joseph E.; Young, Anjuli; Shaginurova, Guzel; Shelton, Debresha; Hawkins, Charlene

2017-01-01

Patients with progressive sarcoidosis exhibit increased expression of programmed death-1 (PD-1) receptor on their CD4+ T cells. Up-regulation of this marker of T cell exhaustion is associated with a reduction in the proliferative response to T cell receptor (TCR) stimulation, a defect that is reversed by PD-1 pathway blockade. Genome-wide association studies and microarray analyses have correlated signaling downstream from the TCR with sarcoidosis disease severity, but the mechanism is not yet known. Reduced phosphatidylinositol 3-kinase (PI3K)/AKT expression inhibits proliferation by inhibiting cell cycle progression. To test the hypothesis that PD-1 expression attenuates TCR-dependent activation of PI3K/AKT activity in progressive systemic sarcoidosis, we analyzed PI3K/AKT/mechanistic target of rapamycin (mTOR) expression at baseline and after PD-1 pathway blockade in CD4+ T cells isolated from patients with sarcoidosis and healthy control subjects. We confirmed an increased percentage of PD-1+ CD4+ T cells and reduced proliferative capacity in patients with sarcoidosis compared with healthy control subjects (P < 0.001). There was a negative correlation with PD-1 expression and proliferative capacity (r = −0.70, P < 0.001). Expression of key mediators of cell cycle progression, including PI3K and AKT, were significantly decreased. Gene and protein expression levels reverted to healthy control levels after PD-1 pathway blockade. Reduction in sarcoidosis CD4+ T cell proliferative capacity is secondary to altered expression of key mediators of cell cycle progression, including the PI3K/AKT/mTOR pathway, via PD-1 up-regulation. This supports the concept that PD-1 up-regulation drives the immunologic deficits associated with sarcoidosis severity by inducing signaling aberrancies in key mediators of cell cycle progression. PMID:27564547

[Down-regulatory effect of Nucleostemin expression on signal molecule of PI3K/AKT/mTOR pathway in HL-60 cells].

PubMed

Jia, Yu; Wei, Yuan-Yu; Zhang, Fan; Li, Zhao-Bo; Liu, Shuai; Yue, Bao-Hong

2014-02-01

This study was purpose to explore the down-regulatory effect of nucleostemin (NS) expression on signal molecules of PI3K/AKT/mTOR pathway belonged to candidate ways of p53-independent signal pathway in the leukemia cells. The expression of NS was interfered by using recombinant lentivirus expression vector NS-RNAi-GV248 to transfect HL-60 cells of p53 deficiency. The expression of NS and signal molecules of PI3K/AKT/mTOR pathway were detected by using Real-time PCR. The results of showed that the HL-60 cells were transfected by recombinant lentivirus vector NS-RNAi-GV248 successfully and with transfection rate up to 80%. According to results of Real-time PCR detection, the inhibition rate of NS gene was 56.5% in HL-60 cells. And the expression levels of PI3K,AKT and GβL mRNA (0.491 ± 0.084,0.398 ± 0.164, 0.472 ± 0.097 respectively) were obviously down-regulated by silencing NS, and showed statistical difference (P < 0.05) in comparison with control (1.002 ± 0.171, 1.000 ± 0.411, 1.001 ± 0.206 respectively) . It is concluded that the changes of signal molecules of PI3K/AKT/mTOR pathway positively correlate with NS down-regulation, which provides evidence for confirming PI3K/AKT/mTOR signal pathway possible as a type of NS p53-independent pathway.

Mitochondrial Quality Control via the PGC1α-TFEB Signaling Pathway Is Compromised by Parkin Q311X Mutation But Independently Restored by Rapamycin.

PubMed

Siddiqui, Almas; Bhaumik, Dipa; Chinta, Shankar J; Rane, Anand; Rajagopalan, Subramanian; Lieu, Christopher A; Lithgow, Gordon J; Andersen, Julie K

2015-09-16

Following its activation by PINK1, parkin is recruited to depolarized mitochondria where it ubiquitinates outer mitochondrial membrane proteins, initiating lysosomal-mediated degradation of these organelles. Mutations in the gene encoding parkin, PARK2, result in both familial and sporadic forms of Parkinson's disease (PD) in conjunction with reductions in removal of damaged mitochondria. In contrast to what has been reported for other PARK2 mutations, expression of the Q311X mutation in vivo in mice appears to involve a downstream step in the autophagic pathway at the level of lysosomal function. This coincides with increased PARIS expression and reduced expression of a reciprocal signaling pathway involving the master mitochondrial regulator peroxisome proliferator-activated receptor-gamma coactivator (PGC1α) and the lysosomal regulator transcription factor EB (TFEB). Treatment with rapamycin was found to independently restore PGC1α-TFEB signaling in a manner not requiring parkin activity and to abrogate impairment of mitochondrial quality control and neurodegenerative features associated with this in vivo model. Losses in PGC1α-TFEB signaling in cultured rat DAergic cells expressing the Q311X mutation associated with reduced mitochondrial function and cell viability were found to be PARIS-dependent and to be independently restored by rapamycin in a manner requiring TFEB. Studies in human iPSC-derived neurons demonstrate that TFEB induction can restore mitochondrial function and cell viability in a mitochondrially compromised human cell model. Based on these data, we propose that the parkin Q311X mutation impacts on mitochondrial quality control via PARIS-mediated regulation of PGC1α-TFEB signaling and that this can be independently restored via upregulation of TFEB function. Mutations in PARK2 are generally associated with loss in ability to interact with PINK1, impacting on autophagic initiation. Our data suggest that, in the case of at least one parkin mutation, Q311X, detrimental effects are due to inhibition at the level of downstream lysosomal function. Mechanistically, this involves elevations in PARIS protein levels and subsequent effects on PGC1α-TFEB signaling that normally regulates mitochondrial quality control. Treatment with rapamycin independently restores PGC1α-TFEB signaling in a manner not requiring parkin activity and abrogates subsequent mitochondrial impairment and neuronal cell loss. Taken in total, our data suggest that the parkin Q311X mutation impacts on mitochondrial quality control via PARIS-mediated regulation of PGC1α-TFEB signaling and that this can be independently restored via rapamycin. Copyright © 2015 the authors 0270-6474/15/3512833-12$15.00/0.

Effect of hypoxia on the expression of nuclear genes encoding mitochondrial proteins in U87 glioma cells.

PubMed

Minchenko, O H; Riabovol, O O; Tsymbal, D O; Minchenko, D O; Ratushna, O O

2016-01-01

We have studied the effect of hypoxia on the expression of nuclear genes encoding mitochondrial proteins in U87 glioma cells under the inhibition of IRE1 (inositol requiring enzyme-1), which controls cell proliferation and tumor growth as a central mediator of endoplasmic reticulum stress. It was shown that hypoxia down-regulated gene expression of malate dehydrogenase 2 (MDH2), malic enzyme 2 (ME2), mitochondrial aspartate aminotransferase (GOT2), and subunit B of succinate dehydrogenase (SDHB) in control (transfected by empty vector) glioma cells in a gene specific manner. At the same time, the expression level of mitochondrial NADP+-dependent isocitrate dehydrogenase 2 (IDH2) and subunit D of succinate dehydrogenase (SDHD) genes in these cells does not significantly change in hypoxic conditions. It was also shown that the inhibition of ІRE1 signaling enzyme function in U87 glioma cells decreases the effect of hypoxia on the expression of ME2, GOT2, and SDHB genes and introduces the sensitivity of IDH2 gene to hypoxia. Furthermore, the expression of all studied genes depends on IRE1-mediated endoplasmic reticulum stress signaling in gene specific manner, because ІRE1 knockdown significantly decreases their expression in normoxic conditions, except for IDH2 gene, which expression level is strongly up-regulated. Therefore, changes in the expression level of nuclear genes encoding ME2, MDH2, IDH2, SDHB, SDHD, and GOT2 proteins possibly reflect metabolic reprogramming of mitochondria by hypoxia and IRE1-mediated endoplasmic reticulum stress signaling and correlate with suppression of glioma cell proliferation under inhibition of the IRE1 enzyme function.

Blood pathway analyses reveal differences between prediabetic subjects with or without dyslipidaemia. The Cardiovascular Risk in Young Finns Study.

PubMed

Laaksonen, Jaakko; Taipale, Tuukka; Seppälä, Ilkka; Raitoharju, Emma; Mononen, Nina; Lyytikäinen, Leo-Pekka; Waldenberger, Melanie; Illig, Thomas; Hutri-Kähönen, Nina; Rönnemaa, Tapani; Juonala, Markus; Viikari, Jorma; Kähönen, Mika; Raitakari, Olli; Lehtimäki, Terho

2017-10-01

Prediabetes often occurs together with dyslipidaemia, which is paradoxically treated with statins predisposing to type 2 diabetes mellitus. We examined peripheral blood pathway profiles in prediabetic subjects with (PR D ) and without dyslipidaemia (PR 0 ) and compared these to nonprediabetic controls without dyslipidaemia (C 0 ). The participants were from the Cardiovascular Risk in Young Finns Study, including 1240 subjects aged 34 to 49 years. Genome-wide expression data of peripheral blood and gene set enrichment analysis were used to investigate the differentially expressed genes and enriched pathways between different subtypes of prediabetes. Pathways for cholesterol synthesis, interleukin-12-mediated signalling events, and downstream signalling in naïve CD8+ T-cells were upregulated in the PR 0 group in comparison with controls (C 0 ). The upregulation of these pathways was independent of waist circumference, blood pressure, smoking status, and insulin. Adjustment for CRP left the CD8+ T-cell signalling and interleukin-12-mediated signalling event pathway upregulated. The cholesterol synthesis pathway was also upregulated when all prediabetic subjects (PR 0 and PR D ) were compared with the nonprediabetic control group. No pathways were upregulated or downregulated when the PR D group was compared with the C 0 group. Five genes in the PR 0 group and 1 in the PR D group were significantly differentially expressed in comparison with the C 0 group. Blood cell gene expression profiles differ significantly between prediabetic subjects with and without dyslipidaemia. Whether this classification may be used in detection of prediabetic individuals at a high risk of cardiovascular complications remains to be examined. Copyright © 2017 John Wiley & Sons, Ltd.

A Nodal-independent and tissue-intrinsic mechanism controls heart-looping chirality

NASA Astrophysics Data System (ADS)

Noël, Emily S.; Verhoeven, Manon; Lagendijk, Anne Karine; Tessadori, Federico; Smith, Kelly; Choorapoikayil, Suma; den Hertog, Jeroen; Bakkers, Jeroen

2013-11-01

Breaking left-right symmetry in bilateria is a major event during embryo development that is required for asymmetric organ position, directional organ looping and lateralized organ function in the adult. Asymmetric expression of Nodal-related genes is hypothesized to be the driving force behind regulation of organ laterality. Here we identify a Nodal-independent mechanism that drives asymmetric heart looping in zebrafish embryos. In a unique mutant defective for the Nodal-related southpaw gene, preferential dextral looping in the heart is maintained, whereas gut and brain asymmetries are randomized. As genetic and pharmacological inhibition of Nodal signalling does not abolish heart asymmetry, a yet undiscovered mechanism controls heart chirality. This mechanism is tissue intrinsic, as explanted hearts maintain ex vivo retain chiral looping behaviour and require actin polymerization and myosin II activity. We find that Nodal signalling regulates actin gene expression, supporting a model in which Nodal signalling amplifies this tissue-intrinsic mechanism of heart looping.

Hypoxic Conditioned Medium From Human Adipose-Derived Stem Cells Promotes Mouse Liver Regeneration Through JAK/STAT3 Signaling

PubMed Central

Lee, Sang Chul; Jeong, Hye Jin; Lee, Sang Kuon

2016-01-01

Adipose-derived stem cells (ASCs) mainly exert their function by secreting materials that are collectively termed the secretome. Despite recent attention to the secretome as an alternative to stem cell therapy, the culture conditions for generating optimal secretome contents have not been determined. Therefore, we investigated the role of hypoxic-conditioned media (HCM) from ASCs. Normoxic-conditioned media (NCM) and HCM were obtained after culturing ASCs in 20% O2 or 1% O2 for 24 hours, respectively. Subsequently, partially hepatectomized mice were infused with saline, control medium, NCM, or HCM, and then sera and liver specimens were obtained for analyses. Hypoxia (1% O2) significantly increased mRNA expression of mediators from ASCs, including interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), hepatocyte growth factor (HGF), and vascular endothelial growth factor (VEGF). HCM infusion significantly increased the number of Ki67-positive cells in the liver (p < .05). HCM infusion significantly increased phospho-signal transducer and activator of transcription 3 (STAT3) and decreased suppressor of cytokine signaling 3 (SOCS3) expression in the liver (p < .05). To determine the role of IL-6 in liver regeneration, we then performed IL-6 RNA interference study. Conditioned media (CM) obtained from ASCs, which were transfected with either siIL-6 or siControl, were administered to partially hepatectomized mice. The siIL-6 CM groups exhibited lower liver proliferation (Ki67-positive cells) and markers of regeneration (protein expression of proliferating cell nuclear antigen, p-STAT3, HGF, and VEGF and liver weights) than the siControl CM groups (p < .05). Taken together, hypoxic preconditioning of ASCs increased expression of mediators promoting anti-inflammatory and regenerative responses. The liver regenerative effects of HCM appear to be mediated by persistent and uninhibited expression of STAT3 in the liver, which results from decreased expression of SOCS3. Significance In this study, it was found that treatment with the medium from hypoxic-preconditioned adipose-derived stem cells (ASCs) increased the viability of hepatotoxic hepatocytes and enhance liver regeneration in partially hepatectomized mice. In addition, the researchers first revealed that the hepatoprotective effects of hypoxic-conditioned media are mediated by persistent and uninhibited expression of signal transducer and activator of transcription 3 in the liver, which result from a decreased expression of suppressor of cytokine signaling 3. Therefore, the hypoxic preconditioning of ASCs is expected to play a crucial role in regenerative medicine by optimizing the production of a highly effective secretome from ASCs. PMID:27102647

Normal p21Ras/MAP kinase pathway expression and function in PBMC from patients with polycystic ovary disease.

PubMed

Buchs, A; Chagag, P; Weiss, M; Kish, E; Levinson, R; Aharoni, D; Rapoport, M J

2004-04-01

Polycystic ovary disease (PCOD) is associated with insulin resistance and increased prevalence of type II diabetes mellitus (T2DM). The p21Ras/MAP kinase is a major intracellular signaling pathway mediating insulin signaling in insulin responsive tissues. The expression, regulation and function of the p21Ras/MAP kinase pathway in PCOD patients were examined. Peripheral blood mononuclear cells (PBMC) were isolated from ten patients with PCOD and ten controls. The expression of p21Ras and its regulatory proteins; hSOS1 and p120GAP were studied. The basal and phytohemaglutinin (PHA) or insulin stimulated phosphorylation of MAP kinase was determined. Expression of p21Ras, and its regulatory proteins hSOS1 and p120GAP were similar in PCOD patients and controls. Basal, PHA and insulin stimulated phosphorylation of MAP kinase, were also comparable in the two groups as well as their PBMC proliferative response. These data indicate that the expression and overall function of the p21Ras/MAP kinase pathway remain intact in non-diabetic patients with PCOD.

Detailed expression profile of the six Glypicans and their modifying enzyme, Notum during chick limb and feather development.

PubMed

Saad, Kawakeb; Theis, Susanne; Otto, Anthony; Luke, Graham; Patel, Ketan

2017-04-30

The development of vertebrate appendages, especially the limb and feather buds are orchestrated by numerous secreted signalling molecules including Sonic Hedgehog, Bone Morphogenetic Proteins, Fibroblast Growth Factors and Wnts. These proteins coordinate the growth and patterning of ectodermal and mesenchymal cells. The influence of signalling molecules is affected over large distances by their concentration (morphogen activity) but also at local levels by the presence of proteins that either attenuate or promote their activity. Glypicans are cell surface molecules that regulate the activity of the major secreted signalling molecules expressed in the limb and feather bud. Here we investigated the expression of all Glypicans during chick limb and feather development. In addition we profiled the expression of Notum, an enzyme that regulates Glypican activity. We show that five of the six Glypicans and Notum are expressed in a dynamic manner during the development of limbs and feathers. We also investigated the expression of key Glypicans and show that they are controlled by signalling molecules highlighting the presence of feedback loops. Lastly we show that Glypicans and Notum are expressed in a tissue specific manner in adult chicken tissues. Our results strongly suggest that the Glypicans and Notum have many as yet undiscovered roles to play during the development of vertebrate appendages. Copyright © 2017 Elsevier B.V. All rights reserved.

The chloroplast division mutant caa33 of Arabidopsis thaliana reveals a crucial impact of chloroplast homeostasis on stress acclimation and retrograde plastid-to-nucleus signaling

PubMed Central

Šimková, Klára; Kim, Chanhong; Gacek, Katarzyna; Baruah, Aiswarya; Laloi, Christophe; Apel, Klaus

2011-01-01

SUMMARY Retrograde plastid-to-nucleus signaling tightly controls and coordinates nuclear and plastid gene expression that is required for plastid biogenesis and chloroplast activities. As chloroplasts act as sensors of environmental changes, plastid-derived signaling also modulates stress responses of plants by transferring stress-related signals and altering nuclear gene expression. Various mutant screens have been undertaken to identify constituents of plastid signaling pathways. Almost all mutations identified in these screens have in common that they target plastid-specific but not extra-plastidic functions. They have been suggested to define either genuine constituents of retrograde signaling pathways or components required for the synthesis of plastid signals. Here we report the characterization of the caa33 (constitutive activator of AAA-ATPase) mutant, which reveals another way of how mutations that affect plastid functions may modulate retrograde plastid signaling. caa33 disturbs a plastid-specific function by impeding plastid division thereby perturbing plastid homeostasis. This results in pre-conditioning plants by activating the expression of stress genes, enhancing pathogen resistance and attenuating the plant’s capacity to respond to plastid signals. Our study reveals an intimate link between chloroplast activity and the plant’s susceptibility to stress and emphasizes the need to consider the possible impact of pre-conditioning on retrograde plastid-to-nucleus signaling. PMID:22014227

Antioxidant and signal modulation properties of plant polyphenols in controlling vascular inflammation.

PubMed

Kostyuk, Vladimir A; Potapovich, Alla I; Suhan, Tatyana O; de Luca, Chiara; Korkina, Liudmila G

2011-05-11

Oxidized low-density lipoproteins (oxLDL) play a critical role in the initiation of atherosclerosis through activation of inflammatory signaling. In the present work we investigated the role of antioxidant and signal modulation properties of plant polyphenols in controlling vascular inflammation. Significant decrease in intracellular NO level and superoxide overproduction was found in human umbilical vein endothelial cells (HUVEC) treated with oxLDL, but not with LDL. The redox imbalance was prevented by the addition of quercetin or resveratrol. Expression analysis of 14 genes associated with oxidative stress and inflammation revealed oxLDL-mediated up-regulation of genes specifically involved in leukocyte recruitment and adhesion. This up-regulation could be partially avoided by the addition of verbascoside or resveratrol, while treatment with quercetin resulted in a further increase in the expression of these genes. Lipopolysaccharide (LPS)-treated HUVEC were also used for the evaluation of anti-inflammatory potency of plant polyphenols. Significant differences between HUVEC treaded with oxLDL and LPS were found in both the expression pattern of inflammation-related genes and the effects of plant polyphenols on cellular responses. The present data indicate that plant polyphenols may affect vascular inflammation not only as antioxidants but also as modulators of inflammatory redox signaling pathways. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

EXPRESSION OF REELIN, ITS RECEPTORS AND ITS INTRACELLULAR SIGNALING PROTEIN, DISABLED-1 (DAB-1) IN THE CANARY BRAIN: RELATIONSHIPS WITH THE SONG CONTROL SYSTEM

PubMed Central

BALTHAZART, JACQUES; VOIGT, CORNELIA; BOSERET, GÉRALDINE; BALL, GREGORY F

2008-01-01

Songbirds produce learned vocalizations that are controlled by a specialized network of neural structures, the song control system. Several nuclei in this song control system demonstrate a marked degree of adult seasonal plasticity. Nucleus volume varies seasonally based on changes in cell size or spacing, and in the case of nucleus HVC and area X on the incorporation of new neurons. Reelin, a large glycoprotein defective in reeler mice, is assumed to determine the final location of migrating neurons in the developing brain. In mammals, reelin is also expressed in the adult brain but its functions are less well characterized. We investigated the relationships between the expression of reelin and/or its receptors and the dramatic seasonal plasticity in the canary (Serinus canaria) brain. We detected a broad distribution of the reelin protein, its messenger RNA and the mRNAs encoding for the reelin receptors (VLDLR and ApoER2) as well as for its intracellular signaling protein, Dab1. These different mRNAs and proteins did not display the same neuroanatomical distribution and were not clearly associated, in an exclusive manner, with telencephalic brain areas that incorporate new neurons in adulthood. Song control nuclei were associated with a particular specialized expression of reelin and its mRNA, with the reelin signal being either denser or lighter in the song nucleus than in the surrounding tissue. The density of reelin-ir structures did not seem to be affected by four weeks of treatment with exogenous testosterone. These observations do not provide conclusive evidence that reelin plays a prominent role in the positioning of new neurons in the adult canary brain but call for additional work on this protein analyzing its expression comparatively during development and in adulthood with a better temporal resolution at critical points in the reproductive cycle when brain plasticity is known to occur. PMID:18448255

Msx homeobox genes critically regulate embryo implantation by controlling paracrine signaling between uterine stroma and epithelium.

PubMed

Nallasamy, Shanmugasundaram; Li, Quanxi; Bagchi, Milan K; Bagchi, Indrani C

2012-01-01

The mammalian Msx homeobox genes, Msx1 and Msx2, encode transcription factors that control organogenesis and tissue interactions during embryonic development. We observed overlapping expression of these factors in uterine epithelial and stromal compartments of pregnant mice prior to embryo implantation. Conditional ablation of both Msx1 and Msx2 in the uterus resulted in female infertility due to a failure in implantation. In these mutant mice (Msx1/2(d/d)), the uterine epithelium exhibited persistent proliferative activity and failed to attach to the embryos. Gene expression profiling of uterine epithelium and stroma of Msx1/2(d/d) mice revealed an elevated expression of several members of the Wnt gene family in the preimplantation uterus. Increased canonical Wnt signaling in the stromal cells activated β-catenin, stimulating the production of a subset of fibroblast growth factors (FGFs) in these cells. The secreted FGFs acted in a paracrine manner via the FGF receptors in the epithelium to promote epithelial proliferation, thereby preventing differentiation of this tissue and creating a non-receptive uterus refractory to implantation. Collectively, these findings delineate a unique signaling network, involving Msx1/2, Wnts, and FGFs, which operate in the uterus at the time of implantation to control the mesenchymal-epithelial dialogue critical for successful establishment of pregnancy.

Branched-Chain Amino Acid Negatively Regulates KLF15 Expression via PI3K-AKT Pathway

PubMed Central

Liu, Yunxia; Dong, Weibing; Shao, Jing; Wang, Yibin; Zhou, Meiyi; Sun, Haipeng

2017-01-01

Recent studies have linked branched-chain amino acid (BCAA) with numerous metabolic diseases. However, the molecular basis of BCAA's roles in metabolic regulation remains to be established. KLF15 (Krüppel-like factor 15) is a transcription factor and master regulator of glycemic, lipid, and amino acids metabolism. In the present study, we found high concentrations of BCAA suppressed KLF15 expression while BCAA starvation induced KLF15 expression, suggesting KLF15 expression is negatively controlled by BCAA.Interestingly, BCAA starvation induced PI3K-AKT signaling. KLF15 induction by BCAA starvation was blocked by PI3K and AKT inhibitors, indicating the activation of PI3K-AKT signaling pathway mediated the KLF15 induction. BCAA regulated KLF15 expression at transcriptional level but not post-transcriptional level. However, BCAA starvation failed to increase the KLF15-promoter-driven luciferase expression, suggesting KLF15 promoter activity was not directly controlled by BCAA. Finally, fasting reduced BCAA abundance in mice and KLF15 expression was dramatically induced in muscle and white adipose tissue, but not in liver. Together, these data demonstrated BCAA negatively regulated KLF15 expression, suggesting a novel molecular mechanism underlying BCAA's multiple functions in metabolic regulation. PMID:29118722

Branched-Chain Amino Acid Negatively Regulates KLF15 Expression via PI3K-AKT Pathway.

PubMed

Liu, Yunxia; Dong, Weibing; Shao, Jing; Wang, Yibin; Zhou, Meiyi; Sun, Haipeng

2017-01-01

Recent studies have linked branched-chain amino acid (BCAA) with numerous metabolic diseases. However, the molecular basis of BCAA's roles in metabolic regulation remains to be established. KLF15 (Krüppel-like factor 15) is a transcription factor and master regulator of glycemic, lipid, and amino acids metabolism. In the present study, we found high concentrations of BCAA suppressed KLF15 expression while BCAA starvation induced KLF15 expression, suggesting KLF15 expression is negatively controlled by BCAA.Interestingly, BCAA starvation induced PI3K-AKT signaling. KLF15 induction by BCAA starvation was blocked by PI3K and AKT inhibitors, indicating the activation of PI3K-AKT signaling pathway mediated the KLF15 induction. BCAA regulated KLF15 expression at transcriptional level but not post-transcriptional level. However, BCAA starvation failed to increase the KLF15-promoter-driven luciferase expression, suggesting KLF15 promoter activity was not directly controlled by BCAA. Finally, fasting reduced BCAA abundance in mice and KLF15 expression was dramatically induced in muscle and white adipose tissue, but not in liver. Together, these data demonstrated BCAA negatively regulated KLF15 expression, suggesting a novel molecular mechanism underlying BCAA's multiple functions in metabolic regulation.

Mesenchymal stem cells promote the sustained expression of CD69 on activated T lymphocytes: roles of canonical and non-canonical NF-κB signalling

PubMed Central

Saldanha-Araujo, Felipe; Haddad, Rodrigo; de Farias, Kelen C R Malmegrim; Souza, Alessandra de Paula Alves; Palma, Patrícia V; Araujo, Amélia G; Orellana, Maristela D; Voltarelli, Julio C; Covas, Dimas T; Zago, Marco A; Panepucci, Rodrigo A

2012-01-01

Abstract Mesenchymal stem cells (MSCs) are known to induce the conversion of activated T cells into regulatory T cells in vitro. The marker CD69 is a target of canonical nuclear factor kappa-B (NF-κB) signalling and is transiently expressed upon activation; however, stable CD69 expression defines cells with immunoregulatory properties. Given its enormous therapeutic potential, we explored the molecular mechanisms underlying the induction of regulatory cells by MSCs. Peripheral blood CD3+ T cells were activated and cultured in the presence or absence of MSCs. CD4+ cell mRNA expression was then characterized by microarray analysis. The drug BAY11-7082 (BAY) and a siRNA against v-rel reticuloendotheliosis viral oncogene homolog B (RELB) were used to explore the differential roles of canonical and non-canonical NF-κB signalling, respectively. Flow cytometry and real-time PCR were used for analyses. Genes with immunoregulatory functions, CD69 and non-canonical NF-κB subunits (RELB and NFKB2) were all expressed at higher levels in lymphocytes co-cultured with MSCs. The frequency of CD69+ cells among lymphocytes cultured alone progressively decreased after activation. In contrast, the frequency of CD69+ cells increased significantly following activation in lymphocytes co-cultured with MSCs. Inhibition of canonical NF-κB signalling by BAY immediately following activation blocked the induction of CD69; however, inhibition of canonical NF-κB signalling on the third day further induced the expression of CD69. Furthermore, late expression of CD69 was inhibited by RELB siRNA. These results indicate that the canonical NF-κB pathway controls the early expression of CD69 after activation; however, in an immunoregulatory context, late and sustained CD69 expression is promoted by the non-canonical pathway and is inhibited by canonical NF-κB signalling. PMID:21777379

Targeted repression of AXIN2 and MYC gene expression using designer TALEs

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

Rennoll, Sherri A.; Scott, Samantha A.; Yochum, Gregory S., E-mail: gsy3@psu.edu

Highlights: • We designed TALE–SID fusion proteins to target AXIN2 and MYC. • TALE–SIDs bound the chromosomal AXIN2 and MYC genes and repressed their expression. • TALE–SIDs repress β-catenin{sup S45F}-dependent AXIN2 and MYC transcription. - Abstract: Designer TALEs (dTALEs) are chimeric transcription factors that can be engineered to regulate gene expression in mammalian cells. Whether dTALEs can block gene transcription downstream of signal transduction cascades, however, has yet to be fully explored. Here we tested whether dTALEs can be used to target genes whose expression is controlled by Wnt/β-catenin signaling. TALE DNA binding domains were engineered to recognize sequences adjacentmore » to Wnt responsive enhancer elements (WREs) that control expression of axis inhibition protein 2 (AXIN2) and c-MYC (MYC). These custom DNA binding domains were linked to the mSin3A interaction domain (SID) to generate TALE–SID chimeric repressors. The TALE–SIDs repressed luciferase reporter activity, bound their genomic target sites, and repressed AXIN2 and MYC expression in HEK293 cells. We generated a novel HEK293 cell line to determine whether the TALE–SIDs could function downstream of oncogenic Wnt/β-catenin signaling. Treating these cells with doxycycline and tamoxifen stimulates nuclear accumulation of a stabilized form of β-catenin found in a subset of colorectal cancers. The TALE–SIDs repressed AXIN2 and MYC expression in these cells, which suggests that dTALEs could offer an effective therapeutic strategy for the treatment of colorectal cancer.« less

The aryl hydrocarbon receptor suppresses osteoblast proliferation and differentiation through the activation of the ERK signaling pathway

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

Yu, Haitao; Du, Yuxuan; Zhang, Xulong

Ahr activation is known to be associated with synovitis and exacerbated rheumatoid arthritis (RA), but its contributions to bone loss have not been completely elucidated. Osteoblast proliferation and differentiation are abnormal at the erosion site in RA. Here, we reported that the expression of Ahr was increased in the hind paws' bone upon collagen-induced arthritis (CIA) in mice, and the levels of Ahr were negatively correlated with bone mineral density (BMD). In addition, immunofluorescent staining showed that the high expression of Ahr was mainly localized in osteoblasts from the CIA mice compared to normal controls. Moreover, the luciferase intensity ofmore » Ahr in the nucleus increased by 12.5% in CIA osteoblasts compared to that in normal controls. In addition, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) activation of the Ahr inhibited pre-osteoblast MC3T3-E1 cellular proliferation and differentiation in a dose-dependent manner. Interestingly, the levels of alkaline phosphatase (ALP) mRNA expression in the osteoblasts of CIA mice were reduced compared to normal controls. In contrast, decreased ALP expression by activated Ahr was completely reversed after pretreatment with an Ahr inhibitor (CH-223191) in MC3T3-E1 cell lines and primary osteoblasts on day 5. Our data further showed that activation of Ahr promoted the phosphorylation of ERK after 5 days. Moreover, Ahr-dependent activation of the ERK signaling pathway decreased the levels of proliferation cells and inhibited ALP activity in MC3T3-E1 cells. These results demonstrated that the high expression of Ahr may suppress osteoblast proliferation and differentiation through activation of the ERK signaling pathway, further enabling bone erosion in CIA mice. - Highlights: • The upregulation of Ahr was localized in osteoblasts of CIA mice. • The overexpression of Ahr suppressed osteoblast development. • The Ahr activated ERK signaling pathway to exacerbate bone erosion.« less

MiR-21 is an Ngf-modulated microRNA that supports Ngf signaling and regulates neuronal degeneration in PC12 cells.

PubMed

Montalban, Enrica; Mattugini, Nicola; Ciarapica, Roberta; Provenzano, Claudia; Savino, Mauro; Scagnoli, Fiorella; Prosperini, Gianluca; Carissimi, Claudia; Fulci, Valerio; Matrone, Carmela; Calissano, Pietro; Nasi, Sergio

2014-06-01

The neurotrophins Ngf, Bdnf, NT-3, NT4-5 have key roles in development, survival, and plasticity of neuronal cells. Their action involves broad gene expression changes at the level of transcription and translation. MicroRNAs (miRs)-small RNA molecules that control gene expression post-transcriptionally-are increasingly implicated in regulating development and plasticity of neural cells. Using PC12 cells as a model system, we show that Ngf modulates changes in expression of a variety of microRNAs, including miRs known to be modulated by neurotrophins-such as the miR-212/132 cluster-and several others, such as miR-21, miR-29c, miR-30c, miR-93, miR-103, miR-207, miR-691, and miR-709. Pathway analysis indicates that Ngf-modulated miRs may regulate many protein components of signaling pathways involved in neuronal development and disease. In particular, we show that miR-21 enhances neurotrophin signaling and controls neuronal differentiation induced by Ngf. Notably, in a situation mimicking neurodegeneration-differentiated neurons deprived of Ngf-this microRNA is able to preserve the neurite network and to support viability of the neurons. These findings uncover a broad role of microRNAs in regulating neurotrophin signaling and suggest that aberrant expression of one or more Ngf-modulated miRs may be involved in neurodegenerative diseases.

Differential Binding of Human ApoE Isoforms to Insulin Receptor is Associated with Aberrant Insulin Signaling in AD Brain Samples.

PubMed

Chan, Elizabeth S; Chen, Christopher; Soong, Tuck Wah; Wong, Boon-Seng

2018-03-01

Apolipoprotein E4 (ApoE4) is the strongest genetic risk factor for sporadic Alzheimer's disease (AD), where inheritance of this isoform predisposes development of AD in a gene dose-dependent manner. Although the mode of action of ApoE4 on AD onset and progression remains unknown, we have previously shown that ApoE4, and not ApoE3 expression, resulted in insulin signaling deficits in the presence of amyloid beta (Aβ). However, these reports were not conducted with clinical samples that more accurately reflect human disease. In this study, we investigated the effect of ApoE genotype on the insulin signaling pathway in control and AD human brain samples. We found that targets of the insulin signaling pathway were attenuated in AD cases, regardless of ApoE isoform. We also found a decrease in GluR1 subunit expression, and an increase NR2B subunit expression in AD cases, regardless of ApoE isoform. Lastly, we observed that more insulin receptor (IR) was immunoprecipitated in control cases, and more Aβ was immunoprecipitated with AD cases. But, when comparing among AD cases, we found that more IR was immunoprecipitated with ApoE3 than ApoE4, and more Aβ was immunoprecipitated with ApoE4 than ApoE3. Our results suggest that the difference in IR binding and effect on protein expression downstream of the IR may affect onset and progression of AD.

Experimentally-Derived Fibroblast Gene Signatures Identify Molecular Pathways Associated with Distinct Subsets of Systemic Sclerosis Patients in Three Independent Cohorts

PubMed Central

Johnson, Michael E.; Mahoney, J. Matthew; Taroni, Jaclyn; Sargent, Jennifer L.; Marmarelis, Eleni; Wu, Ming-Ru; Varga, John; Hinchcliff, Monique E.; Whitfield, Michael L.

2015-01-01

Genome-wide expression profiling in systemic sclerosis (SSc) has identified four ‘intrinsic’ subsets of disease (fibroproliferative, inflammatory, limited, and normal-like), each of which shows deregulation of distinct signaling pathways; however, the full set of pathways contributing to this differential gene expression has not been fully elucidated. Here we examine experimentally derived gene expression signatures in dermal fibroblasts for thirteen different signaling pathways implicated in SSc pathogenesis. These data show distinct and overlapping sets of genes induced by each pathway, allowing for a better understanding of the molecular relationship between profibrotic and immune signaling networks. Pathway-specific gene signatures were analyzed across a compendium of microarray datasets consisting of skin biopsies from three independent cohorts representing 80 SSc patients, 4 morphea, and 26 controls. IFNα signaling showed a strong association with early disease, while TGFβ signaling spanned the fibroproliferative and inflammatory subsets, was associated with worse MRSS, and was higher in lesional than non-lesional skin. The fibroproliferative subset was most strongly associated with PDGF signaling, while the inflammatory subset demonstrated strong activation of innate immune pathways including TLR signaling upstream of NF-κB. The limited and normal-like subsets did not show associations with fibrotic and inflammatory mediators such as TGFβ and TNFα. The normal-like subset showed high expression of genes associated with lipid signaling, which was absent in the inflammatory and limited subsets. Together, these data suggest a model by which IFNα is involved in early disease pathology, and disease severity is associated with active TGFβ signaling. PMID:25607805

Korean Red Ginseng inhibits apoptosis in neuroblastoma cells via estrogen receptor β-mediated phosphatidylinositol-3 kinase/Akt signaling

PubMed Central

Nguyen, Cuong Thach; Luong, Truc Thanh; Kim, Gyu-Lee; Pyo, Suhkneung; Rhee, Dong-Kwon

2014-01-01

Background Ginseng has been shown to exert antistress effects both in vitro and in vivo. However, the effects of ginseng on stress in brain cells are not well understood. This study investigated how Korean Red Ginseng (KRG) controls hydrogen peroxide-induced apoptosis via regulation of phosphatidylinositol-3 kinase (PI3K)/Akt and estrogen receptor (ER)-β signaling. Methods Human neuroblastoma SK-N-SH cells were pretreated with KRG and subsequently exposed to H2O2. The ability of KRG to inhibit oxidative stress-induced apoptosis was assessed in MTT cytotoxicity assays. Apoptotic protein expression was examined by Western blot analysis. The roles of ER-β, PI3K, and p-Akt signaling in KRG regulation of apoptosis were studied using small interfering RNAs and/or target antagonists. Results Pretreating SK-N-SH cells with KRG decreased expression of the proapoptotic proteins p-p53 and caspase-3, but increased expression of the antiapoptotic protein BCL2. KRG pretreatment was also associated with increased ER-β, PI3K, and p-Akt expression. Conversely, ER-β inhibition with small interfering RNA or inhibitor treatment increased p-p53 and caspase-3 levels, but decreased BCL2, PI3K, and p-Akt expression. Moreover, inhibition of PI3K/Akt signaling diminished p-p53 and caspase-3 levels, but increased BCL2 expression. Conclusion Collectively, the data indicate that KRG represses oxidative stress-induced apoptosis by enhancing PI3K/Akt signaling via upregulation of ER-β expression. PMID:25535479

Differential Anoxic Expression of Sugar-Regulated Genes Reveals Diverse Interactions between Sugar and Anaerobic Signaling Systems in Rice

PubMed Central

Lim, Mi-na; Lee, Sung-eun; Yim, Hui-kyeong; Kim, Jeong Hoe; Yoon, In Sun; Hwang, Yong-sic

2013-01-01

The interaction between the dual roles of sugar as a metabolic fuel and a regulatory molecule was unveiled by examining the changes in sugar signaling upon oxygen deprivation, which causes the drastic alteration in the cellular energy status. In our study, the expression of anaerobically induced genes is commonly responsive to sugar, either under the control of hexokinase or non-hexokinase mediated signaling cascades. Only sugar regulation via the hexokinase pathway was susceptible for O2 deficiency or energy deficit conditions evoked by uncoupler. Examination of sugar regulation of those genes under anaerobic conditions revealed the presence of multiple paths underlying anaerobic induction of gene expression in rice, subgrouped into three distinct types. The first of these, which was found in type-1 genes, involved neither sugar regulation nor additional anaerobic induction under anoxia, indicating that anoxic induction is a simple result from the release of sugar repression by O2-deficient conditions. In contrast, type-2 genes also showed no sugar regulation, albeit with enhanced expression under anoxia. Lastly, expression of type-3 genes is highly enhanced with sugar regulation sustained under anoxia. Intriguingly, the inhibition of the mitochondrial ATP synthesis can reproduce expression pattern of a specific set of anaerobically induced genes, implying that rice cells may sense O2 deprivation, partly via perception of the perturbed cellular energy status. Our study of interaction between sugar signaling and anaerobic conditions has revealed that sugar signaling and the cellular energy status are likely to communicate with each other and influence anaerobic induction of gene expression in rice. PMID:23852132

Higher Matrix Stiffness Upregulates Osteopontin Expression in Hepatocellular Carcinoma Cells Mediated by Integrin β1/GSK3β/β-Catenin Signaling Pathway.

PubMed

You, Yang; Zheng, Qiongdan; Dong, Yinying; Wang, Yaohui; Zhang, Lan; Xue, Tongchun; Xie, Xiaoying; Hu, Chao; Wang, Zhiming; Chen, Rongxin; Wang, Yanhong; Cui, Jiefeng; Ren, Zhenggang

2015-01-01

Increased stromal stiffness is associated with hepatocellular carcinoma (HCC) development and progression. However, the molecular mechanism by which matrix stiffness stimuli modulate HCC progress is largely unknown. In this study, we explored whether matrix stiffness-mediated effects on osteopontin (OPN) expression occur in HCC cells. We used a previously reported in vitro culture system with tunable matrix stiffness and found that OPN expression was remarkably upregulated in HCC cells with increasing matrix stiffness. Furthermore, the phosphorylation level of GSK3β and the expression of nuclear β-catenin were also elevated, indicating that GSK3β/β-catenin pathway might be involved in OPN regulation. Knock-down analysis of integrin β1 showed that OPN expression and p-GSK3β level were downregulated in HCC cells grown on high stiffness substrate compared with controls. Simultaneously, inhibition of GSK-3β led to accumulation of β-catenin in the cytoplasm and its enhanced nuclear translocation, further triggered the rescue of OPN expression, suggesting that the integrin β1/GSK-3β/β-catenin pathway is specifically activated for matrix stiffness-mediated OPN upregulation in HCC cells. Tissue microarray analysis confirmed that OPN expression was positively correlated with the expression of LOX and COL1. Taken together, high matrix stiffness upregulated OPN expression in HCC cells via the integrin β1/GSK-3β/β-catenin signaling pathway. It highlights a new insight into a pathway involving physical mechanical signal and biochemical signal molecules which contributes to OPN expression in HCC cells.

KIT Signaling Promotes Growth of Colon Xenograft Tumors in Mice and Is Up-Regulated in a Subset of Human Colon Cancers.

PubMed

Chen, Evan C; Karl, Taylor A; Kalisky, Tomer; Gupta, Santosh K; O'Brien, Catherine A; Longacre, Teri A; van de Rijn, Matt; Quake, Stephen R; Clarke, Michael F; Rothenberg, Michael E

2015-09-01

Receptor tyrosine kinase (RTK) inhibitors have advanced colon cancer treatment. We investigated the role of the RTK KIT in development of human colon cancer. An array of 137 patient-derived colon tumors and their associated xenografts were analyzed by immunohistochemistry to measure levels of KIT and its ligand KITLG. KIT and/or KITLG was stably knocked down by expression of small hairpin RNAs from lentiviral vectors in DLD1, HT29, LS174T, and COLO320 DM colon cancer cell lines, and in UM-COLON#8 and POP77 xenografts; cells transduced with only vector were used as controls. Cells were analyzed by real-time quantitative reverse transcription polymerase chain reaction, single-cell gene expression analysis, flow cytometry, and immunohistochemical, immunoblot, and functional assays. Xenograft tumors were grown from control and KIT-knockdown DLD1 and UM-COLON#8 cells in immunocompromised mice and compared. Some mice were given the RTK inhibitor imatinib after injection of cancer cells; tumor growth was measured based on bioluminescence. We assessed tumorigenicity using limiting dilution analysis. KIT and KITLG were expressed heterogeneously by a subset of human colon tumors. Knockdown of KIT decreased proliferation of colon cancer cell lines and growth of xenograft tumors in mice compared with control cells. KIT knockdown cells had increased expression of enterocyte markers, decreased expression of cycling genes, and, unexpectedly, increased expression of LGR5 associated genes. No activating mutations in KIT were detected in DLD1, POP77, or UM-COLON#8 cells. However, KITLG-knockdown DLD1 cells formed smaller xenograft tumors than control cells. Gene expression analysis of single CD44(+) cells indicated that KIT can promote growth via KITLG autocrine and/or paracrine signaling. Imatinib inhibited growth of KIT(+) colon cancer organoids in culture and growth of xenograft tumors in mice. Cancer cells with endogenous KIT expression were more tumorigenic in mice. KIT and KITLG are expressed by a subset of human colon tumors. KIT signaling promotes growth of colon cancer cells and organoids in culture and xenograft tumors in mice via its ligand, KITLG, in an autocrine or paracrine manner. Patients with KIT-expressing colon tumors can benefit from KIT RTK inhibitors. Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights reserved.

KIT Signaling Promotes Growth of Colon Xenograft Tumors in Mice and is Upregulated in a Subset of Human Colon Cancers

PubMed Central

Chen, Evan C.; Karl, Taylor A.; Kalisky, Tomer; Gupta, Santosh K.; O’Brien, Catherine A.; Longacre, Teri A.; van de Rijn, Matt; Quake, Stephen R.; Clarke, Michael F.; Rothenberg, Michael E.

2015-01-01

Background & Aims Receptor tyrosine kinase (RTK) inhibitors have advanced colon cancer treatment. We investigated the role of the RTK KIT in development of human colon cancer. Methods An array of 137 patient-derived colon tumors and their associated xenografts were analyzed by immunohistochemistry to measure levels of KIT and its ligand KITLG. KIT and/or KITLG was stably knocked down by expression of small hairpin RNAs from lentiviral vectors in DLD1, HT29, LS174T, and COLO320 colon cancer cell lines, and in UM-COLON#8 and POP77 xenografts; cells transduced with only vector were used as controls. Cells were analyzed by real-time quantitative reverse transcription PCR, single-cell gene expression analysis, flow cytometry, and immunohistochemical, immunoblot, and functional assays. Xenograft tumors were grown from control and KIT-knockdown DLD1 and UM-COLON#8 cells in immunocompromised mice and compared. Some mice were given the RTK inhibitor imatinib following injection of cancer cells; tumor growth was measured based on bioluminescence. We assessed tumorigenicity using limiting dilution analysis. Results KIT and KITLG were expressed heterogeneously by a subset of human colon tumors. Knockdown of KIT decreased proliferation of colon cancer cell lines and growth of xenograft tumors in mice, compared with control cells. KIT knockdown cells had increased expression of enterocyte markers, decreased expression of cycling genes, and, unexpectedly, increased expression of LGR5-associated genes. No activating mutations in KIT were detected in DLD1, POP77, or UM-COLON#8 cell lines. However, KITLG-knockdown DLD1 cells formed smaller xenograft tumors than control cells. Gene expression analysis of single CD44+ cells indicated that KIT may promote growth via KITLG autocrine and/or paracrine signaling. Imatinib inhibited growth of KIT+ colon cancer organoids in culture and growth of xenograft tumors in mice. Cancer cells with endogenous KIT expression were more tumorigenic in mice. Conclusions KIT and KITLG are expressed by a subset of human colon tumors. KIT signaling promotes growth of colon cancer cells and organoids in culture and xenograft tumors in mice via its ligand, KITLG, in an autocrine or paracrine manner. Patients with KIT-expressing colon tumors may benefit from KIT RTK inhibitors. PMID:26026391

Analysis of the expression and function of Wnt-5a and Wnt-5b in developing and regenerating axolotl (Ambystoma mexicanum) limbs.

PubMed

Ghosh, Sukla; Roy, Stéphane; Séguin, Carl; Bryant, Susan V; Gardiner, David M

2008-05-01

Urodele amphibians are unique adult vertebrates because they are able to regenerate body parts after amputation. Studies of urodele limb regeneration, the key model system for vertebrate regeneration, have led to an understanding of the origin of blastema cells and the importance of positional interactions between blastema cells in the control of growth and pattern formation. Progress is now being made in the identification of the signaling pathways that regulate dedifferentiation, blastema morphogenesis, growth and pattern formation. Members of the Wnt family of secreted proteins are expressed in developing and regenerating limbs, and have the potential to control growth, pattern formation and differentiation. We have studied the expression of two non-canonical Wnt genes, Wnt-5a and Wnt-5b. We report that they are expressed in equivalent patterns during limb development and limb regeneration in the axolotl (Ambystoma mexicanum), and during limb development in other tetrapods, implying conservation of function. Our analysis of the effects of ectopic Wnt-5a expression is consistent with the hypothesis that canonical Wnt signaling functions during the early stages of regeneration to control the dedifferentiation of stump cells giving rise to the regeneration-competent cells of the blastema.

RNA sequencing identifies upregulated kyphoscoliosis peptidase and phosphatidic acid signaling pathways in muscle hypertrophy generated by transgenic expression of myostatin propeptide.

PubMed

Miao, Yuanxin; Yang, Jinzeng; Xu, Zhong; Jing, Lu; Zhao, Shuhong; Li, Xinyun

2015-04-09

Myostatin (MSTN), a member of the transforming growth factor-β superfamily, plays a crucial negative role in muscle growth. MSTN mutations or inhibitions can dramatically increase muscle mass in most mammal species. Previously, we generated a transgenic mouse model of muscle hypertrophy via the transgenic expression of the MSTN N-terminal propeptide cDNA under the control of the skeletal muscle-specific MLC1 promoter. Here, we compare the mRNA profiles between transgenic mice and wild-type littermate controls with a high-throughput RNA sequencing method. The results show that 132 genes were significantly differentially expressed between transgenic mice and wild-type control mice; 97 of these genes were up-regulated, and 35 genes were down-regulated in the skeletal muscle. Several genes that had not been reported to be involved in muscle hypertrophy were identified, including up-regulated myosin binding protein H (mybph), and zinc metallopeptidase STE24 (Zmpste24). In addition, kyphoscoliosis peptidase (Ky), which plays a vital role in muscle growth, was also up-regulated in the transgenic mice. Interestingly, a pathway analysis based on grouping the differentially expressed genes uncovered that cardiomyopathy-related pathways and phosphatidic acid (PA) pathways (Dgki, Dgkz, Plcd4) were up-regulated. Increased PA signaling may increase mTOR signaling, resulting in skeletal muscle growth. The findings of the RNA sequencing analysis help to understand the molecular mechanisms of muscle hypertrophy caused by MSTN inhibition.

Reduction of Syndecan Transcript Levels in the Insulin-Producing Cells Affects Glucose Homeostasis in Adult Drosophila melanogaster.

PubMed

Warren, Jonathan L; Hoxha, Eneida; Jumbo-Lucioni, Patricia; De Luca, Maria

2017-11-01

Signaling by direct cell-matrix interactions has been shown to impact the transcription, secretion, and storage of insulin in mammalian β cells. However, more research is still needed in this area. Syndecans are transmembrane heparan sulfate proteoglycans that function independently and in synergy with integrin-mediated signaling to mediate cell adhesion to the extracellular matrix. In this study, we used the model organism Drosophila melanogaster to determine whether knockdown of the Syndecan (Sdc) gene expression specifically in the insulin-producing cells (IPCs) might affect insulin-like peptide (ILP) production and secretion. IPCs of adult flies produce three ILPs (ILP2, ILP3, and ILP5), which have significant homology to mammalian insulin. We report that flies with reduced Sdc expression in the IPCs did not show any difference in the expression of ilp genes compared to controls. However, they had significantly reduced levels of the circulating ILP2 protein, higher circulating carbohydrates, and were less glucose tolerant than control flies. Finally, we found that IPCs-specific Sdc knockdown led to reduced levels of head Glucose transporter1 gene expression, extracellular signal-regulated kinase phosphorylation, and reactive oxygen species. Taken together, our findings suggest a cell autonomous role for Sdc in insulin release in D. melanogaster.

The effect of mepiquat chloride on elongation of cotton (Gossypium hirsutum L.) internode is associated with low concentration of gibberellic acid.

PubMed

Wang, Li; Mu, Chun; Du, Mingwei; Chen, Yin; Tian, Xiaoli; Zhang, Mingcai; Li, Zhaohu

2014-08-01

The growth regulator mepiquat chloride (MC) is globally used in cotton (Gossypium hirsutum L.) canopy manipulation to avoid excess growth and yield loss. However, little information is available as to whether the modification of plant architecture by MC is related to alterations in gibberellic acid (GA) metabolism and signaling. Here, the role of GA metabolism and signaling was investigated in cotton seedlings treated with MC. The MC significantly decreased endogenous GA3 and GA4 levels in the elongating internode, which inhibited cell elongation by downregulating GhEXP and GhXTH2, and then reducing plant height. Biosynthetic and metabolic genes of GA were markedly suppressed within 2-10d of MC treatment, which also downregulated the expression of DELLA-like genes. A remarkable feedback regulation was observed at the early stage of MC treatment when GA biosynthetic and metabolic genes expression was evidently upregulated. Mepiquat chloride action was controlled by temporal translocation and spatial accumulation which regulated GA biosynthesis and signal expression for maintaining GA homeostasis. The results suggested that MC application could reduce endogenous GA levels in cotton through controlled GA biosynthetic and metabolic genes expression, which might inhibit cell elongation, thereby shortening the internode and reducing plant height. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Akt1 Controls the Timing and Amplitude of Vascular Circadian Gene Expression

PubMed Central

Luciano, Amelia K.; Santana, Jeans M.; Velazquez, Heino; Sessa, William C.

2017-01-01

The AKT signaling pathway is important for circadian rhythms in mammals and flies (Drosophila). However, AKT signaling in mammals is more complicated since there are 3 isoforms of AKT, each performing slightly different functions. Here we study the most ubiquitous AKT isoform, Akt1, and its role at the organismal level in the central and vascular peripheral clocks. Akt1−/− mice exhibit relatively normal behavioral rhythms with only minor differences in circadian gene expression in the liver and heart. However, circadian gene expression in the Akt1−/− aorta, compared with control aorta, follows a distinct pattern. In the Akt1−/− aorta, positive regulators of circadian transcription have lower amplitude rhythms and peak earlier in the day, and negative circadian regulators are expressed at higher amplitudes and peak later in the day. In endothelial cells, negative circadian regulators exhibit an increased amplitude of expression, while the positive circadian regulators are arrhythmic with a decreased amplitude of expression. This indicates that Akt1 conditions the normal circadian rhythm in the vasculature more so than in other peripheral tissues where other AKT isoforms or kinases might be important for daily rhythms. PMID:28452287

Akt1 Controls the Timing and Amplitude of Vascular Circadian Gene Expression.

PubMed

Luciano, Amelia K; Santana, Jeans M; Velazquez, Heino; Sessa, William C

2017-06-01

The AKT signaling pathway is important for circadian rhythms in mammals and flies ( Drosophila). However, AKT signaling in mammals is more complicated since there are 3 isoforms of AKT, each performing slightly different functions. Here we study the most ubiquitous AKT isoform, Akt1, and its role at the organismal level in the central and vascular peripheral clocks. Akt1 -/- mice exhibit relatively normal behavioral rhythms with only minor differences in circadian gene expression in the liver and heart. However, circadian gene expression in the Akt1 -/- aorta, compared with control aorta, follows a distinct pattern. In the Akt1 -/- aorta, positive regulators of circadian transcription have lower amplitude rhythms and peak earlier in the day, and negative circadian regulators are expressed at higher amplitudes and peak later in the day. In endothelial cells, negative circadian regulators exhibit an increased amplitude of expression, while the positive circadian regulators are arrhythmic with a decreased amplitude of expression. This indicates that Akt1 conditions the normal circadian rhythm in the vasculature more so than in other peripheral tissues where other AKT isoforms or kinases might be important for daily rhythms.

Glucocorticoid and cytokine crosstalk: Feedback, feedforward, and co-regulatory interactions determine repression or resistance.

PubMed

Newton, Robert; Shah, Suharsh; Altonsy, Mohammed O; Gerber, Antony N

2017-04-28

Inflammatory signals induce feedback and feedforward systems that provide temporal control. Although glucocorticoids can repress inflammatory gene expression, glucocorticoid receptor recruitment increases expression of negative feedback and feedforward regulators, including the phosphatase, DUSP1, the ubiquitin-modifying enzyme, TNFAIP3, or the mRNA-destabilizing protein, ZFP36. Moreover, glucocorticoid receptor cooperativity with factors, including nuclear factor-κB (NF-κB), may enhance regulator expression to promote repression. Conversely, MAPKs, which are inhibited by glucocorticoids, provide feedforward control to limit expression of the transcription factor IRF1, and the chemokine, CXCL10. We propose that modulation of feedback and feedforward control can determine repression or resistance of inflammatory gene expression toglucocorticoid. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

The intracellular carboxyl tail of the PAR-2 receptor controls intracellular signaling and cell death.

PubMed

Zhu, Zhihui; Stricker, Rolf; Li, Rong yu; Zündorf, Gregor; Reiser, Georg

2015-03-01

The protease-activated receptors are a group of unique G protein-coupled receptors, including PAR-1, PAR-2, PAR-3 and PAR-4. PAR-2 is activated by multiple trypsin-like serine proteases, including trypsin, tryptase and coagulation proteases. The clusters of phosphorylation sites in the PAR-2 carboxyl tail are suggested to be important for the binding of adaptor proteins to initiate intracellular signaling to Ca(2+) and mitogen-activated protein kinases. To explore the functional role of PAR-2 carboxyl tail in controlling intracellular Ca(2+), ERK and AKT signaling, a series of truncated mutants containing different clusters of serines/threonines were generated and expressed in HEK293 cells. Firstly, we observed that lack of the complete C-terminus of PAR-2 in a mutated receptor gave a relatively low level of localization on the cell plasma membrane. Secondly, the shortened carboxyl tail containing 13 amino acids was sufficient for receptor internalization. Thirdly, the cells expressing truncation mutants showed deficits in their capacity to couple to intracellular Ca(2+) and ERK and AKT signaling upon trypsin challenge. In addition, HEK293 cells carrying different PAR-2 truncation mutants displayed decreased levels of cell survival after long-lasting trypsin stimulation. In summary, the PAR-2 carboxyl tail was found to control the receptor localization, internalization, intracellular Ca(2+) responses and signaling to ERK and AKT. The latter can be considered to be important for cell death control.

Differentially Expressed Long Non-Coding RNAs Were Predicted to Be Involved in the Control of Signaling Pathways in Pediatric Astrocytoma.

PubMed

Ruiz Esparza-Garrido, Ruth; Rodríguez-Corona, Juan Manuel; López-Aguilar, Javier Enrique; Rodríguez-Florido, Marco Antonio; Velázquez-Wong, Ana Claudia; Viedma-Rodríguez, Rubí; Salamanca-Gómez, Fabio; Velázquez-Flores, Miguel Ángel

2017-10-01

Expression changes for long non-coding RNAs (lncRNAs) have been identified in adult glioblastoma multiforme (GBM) and in a mixture of adult and pediatric astrocytoma. Since adult and pediatric astrocytomas are molecularly different, the mixture of both could mask specific features in each. We determined the global expression patterns of lncRNAs and messenger RNA (mRNAs) in pediatric astrocytoma of different histological grades. Transcript expression changes were determined with an HTA 2.0 array. lncRNA interactions with microRNAs and mRNAs were predicted by using an algorithm and the LncTar tool, respectively. Interactomes were constructed with the HIPPIE database and visualized with the Cytoscape platform. The array showed expression changes in 156 and 207 lncRNAs in tumors (versus the control) and in pediatric GBM (versus low-grade astrocytoma), respectively. Predictions identified lncRNAs that have putative microRNA binding sites, which might suggest that they function as sponges in these tumors. Also, lncRNAs were shown to interact with many mRNAs, such as Pleckstrin homology-like domain, family A, member 1 (PHLDA1) and sulfatase 2 (SULF2). For example, qPCR found long intergenic non-coding RNA regulator of reprogramming (linc-RoR) expression levels upregulated in pediatric GBM when they were compared with control tissues or with low-grade tumors. Meanwhile, PHLDA1 and ELAV-like RNA binding protein 1 (ELAV1) showed expression changes in tumors relative to the control. Our data showed many lncRNAs with expression changes in pediatric astrocytoma, which might be involved in the regulation of different signaling pathways.

Downregulation of toll-like receptor-mediated signalling pathways in oral lichen planus.

PubMed

Sinon, Suraya H; Rich, Alison M; Parachuru, Venkata P B; Firth, Fiona A; Milne, Trudy; Seymour, Gregory J

2016-01-01

The objective of this study was to investigate the expression of Toll-like receptors (TLR) and TLR-associated signalling pathway genes in oral lichen planus (OLP). Initially, immunohistochemistry was used to determine TLR expression in 12 formalin-fixed archival OLP tissues with 12 non-specifically inflamed oral tissues as controls. RNA was isolated from further fresh samples of OLP and non-specifically inflamed oral tissue controls (n = 6 for both groups) and used in qRT(2)-PCR focused arrays to determine the expression of TLRs and associated signalling pathway genes. Genes with a statistical significance of ±two-fold regulation (FR) and a P-value < 0.05 were considered as significantly regulated. Significantly more TLR4(+) cells were present in the inflammatory infiltrate in OLP compared with the control tissues (P < 0.05). There was no statistically significant difference in the numbers of TLR2(+) and TLR8(+) cells between the groups. TLR3 was significantly downregulated in OLP (P < 0.01). TLR8 was upregulated in OLP, but the difference between the groups was not statistically significant. The TLR-mediated signalling-associated protein genes MyD88 and TIRAP were significantly downregulated (P < 0.01 and P < 0.05), as were IRAK1 (P < 0.05), MAPK8 (P < 0.01), MAP3K1 (P < 0.05), MAP4K4 (P < 0.05), REL (P < 0.01) and RELA (P < 0.01). Stress proteins HMGB1 and the heat shock protein D1 were significantly downregulated in OLP (P < 0.01). These findings suggest a downregulation of TLR-mediated signalling pathways in OLP lesions. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

IRE1 inhibition affects the expression of insulin-like growth factor binding protein genes and modifies its sensitivity to glucose deprivation in U87 glioma cells.

PubMed

Minchenko, D O; Kharkova, A P; Tsymbal, D O; Karbovskyi, L L; Minchenko, O H

2015-10-01

The aim of the present study was to investigate the effect of inhibition of endoplasmic reticulum stress signaling mediated by IRE1/ERN1 (inositol-requiring enzyme 1/endoplasmic reticulum to nucleus signaling 1) on the expression of genes encoding different groups of insulin-like growth binding proteins (IGFBP6 and IGFBP7) and CCN family (IGFBP8/CTGF/CCN2, IGFBP9/NOV/CCN3, IGFBP10/CYR61/CCN1, WISP1/CCN4, and WISP2/CCN5) and its sensitivity to glucose deprivation in U87 glioma cells. The expression of IGFBP6, IGFBP7, IGFBP8, IGFBP9, IGFBP10, WISP1, and WISP2 genes was studied by qPCR in control U87 glioma cells (wild-type) and its subline with IRE1 signaling enzyme loss of function upon glucose deprivation. The expression of IGFBP8, IGFBP9, and WISP2 genes was up-regulated in control glioma cells upon glucose deprivation with most significant changes for IGFBP9 gene. At the same time, the expression of IGFBP6, IGFBP10, and WISP1 genes was resistant to glucose deprivation in these glioma cells, but the IGFBP7 gene expression was down-regulated. The inhibition of both enzymatic activities (kinase and endoribonuclease) of IRE1 in glioma cells modified the sensitivity of most studied gene expressions to glucose deprivation condition: introduced sensitivity of IGFBP10 and WISP1 genes to glucose deprivation, enhanced the effect of this deprivation on IGFBP7 and IGFBP9 gene expressions, and reduced this effect on WISP2 gene and induced suppressive effect of glucose deprivation on the expression of IGFBP8 gene. Furthermore, the inhibition of IRE1 strongly affected the expression of all studied genes in glioma cells upon regular growing condition in gene specific manner: up-regulated the expression levels of IGFBP7, IGFBP8, IGFBP10, WISP1, and WISP2 genes and down-regulated the IGFBP6 and IGFBP9 genes. The data of this investigation demonstrate that the expression of IGFBP7, IGFBP8, IGFBP9, and WISP2 genes are sensitive to glucose deprivation in U87 glioma cells and that inhibition of IRE1 signaling enzyme function may significantly affect the expression of all studied genes in the presence of glucose as well as modify the effect of glucose deprivation on the expression of most studied genes. These data also show that proteins encoded by these genes may participate in the regulation of metabolic and proliferative processes via IGF/INS receptors and possibly other signaling pathways as well, via IRE1 signaling, which is a central mediator of the unfolded protein response and an important component of the tumor growth and metabolic diseases.

Calcium signalling from the type I inositol 1,4,5-trisphosphate receptor is required at early phase of liver regeneration.

PubMed

Oliveira, André G; Andrade, Viviane A; Guimarães, Erika S; Florentino, Rodrigo M; Sousa, Pedro A; Marques, Pedro E; Melo, Flávia M; Ortega, Miguel J; Menezes, Gustavo B; Leite, M Fatima

2015-04-01

Liver regeneration is a multistage process that unfolds gradually, with different mediators acting at different stages of regeneration. Calcium (Ca(2+) ) signalling is essential for liver regeneration. In hepatocytes, Ca(2+) signalling results from the activation of inositol 1,4,5-trisphosphate receptors (InsP3 R) of which two of the three known isoforms are expressed (InsP3 R-I and InsP3 R-II). Here, we investigated the role of the InsP3 R-I-dependent Ca(2+) signals in hepatic proliferation during liver regeneration. Partial hepatectomy (HX) in combination with knockdown of InsP3 R-I (AdsiRNA-I) was used to evaluate the role of InsP3 R-I on liver regeneration and hepatocyte proliferation, as assessed by liver to body mass ratio, PCNA expression, immunoblots and measurements of intracellular Ca(2+) signalling. AdsiRNA-I efficiently infected the liver as demonstrated by the expression of β-galactosidase throughout the liver lobules. Moreover, this construct selectively and efficiently reduced the expression of InsP3 R-I, as evaluated by immunoblots. Expression of AdsiRNA-I in liver decreased peak Ca(2+) amplitude induced by vasopressin in isolated hepatocytes 2 days after HX. Reduced InsP3 R-I expression prior to HX also delayed liver regeneration, as measured by liver to body weight ratio, and reduced hepatocyte proliferation, as evaluated by PCNA staining, at the same time point. At later stages of regeneration, control hepatocytes showed a decreased expression of InsP3 R, as well as reduced InsP3 R-mediated Ca(2+) signalling, events that did not affect liver growth. Together, these results show that InsP3 R-I-dependent Ca(2+) signalling is an early triggering pathway required for liver regeneration. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Expression of Wnt and Notch signaling pathways in inflammatory bowel disease treated with mesenchymal stem cell transplantation: evaluation in a rat model.

PubMed

Xing, Yanfen; Chen, Xiaojie; Cao, Yanwen; Huang, Jianyun; Xie, Xuhong; Wei, Yaming

2015-05-22

The purpose of this study was to investigate the expression of Wnt and Notch signaling pathway-related genes in inflammatory bowel disease (IBD) treated with mesenchymal stem cell transplantation (MSCT). TNBS (2,4,6-trinitrobenzene sulfonic acid) was used to establish IBD in a rat model. Mesenchymal stem cells (MSCs) were transplanted via tail vein transfusion. Saline water was used in a control group. The expression of Wnt and Notch main signaling molecules was screened by gene chips and verified by quantitative reverse transcription-polymerase chain reaction in the IBD rat model on day 14 and day 28 after transplantation. The IBD rat models were successfully established and MSCs were transplanted into those models. Genome-wide expression profile chips identified a total of 388 differentially expressive genes, of which 191 were upregulated and 197 were downregulated in the MSC-transplanted group in comparison with the IBD control group. Real-time quantitative polymerase chain reaction results showed that the level of Olfm4 mRNA expression in the IBD group (2.54±0.20) was significantly increased compared with the MSCT group (1.39±0.54) and the normal group (1.62±0.25) (P <0.05). The Wnt3a mRNA was more highly expressed in IBD rats (2.92±0.94) and decreased in MSCT rats (0.17±0.63, P <0.05). The expression of GSK-3β mRNA was decreased in the setting of inflammation (0.65±0.04 versus 1.00±0.01 in normal group, P <0.05) but returned to normal levels after MSCT (0.81±0.17). The expression of β-catenin was observed to increase in IBD tissues (1.76±0.44) compared with normal tissues (1.00±0.01, P <0.05), but no difference was found in the MSCT group (1.12±0.36). Wnt11 declined at 14 days and returned to normal levels at 28 days in the IBD group; in comparison, a significantly lower expression was found in MSCT rats. There were no differences in the expression of Fzd3, c-myc, TCF4, and Wnt5a in inflammation, but all of those genes declined after MSCT treatment. The canonical Wnt and Notch signaling pathways are activated in IBD and may be suppressed by stem cell transplantation to differentiate into intestinal epithelium after MSCT. Moreover, the non-canonical Wnt signaling may be inhibited by canonical Wnt signaling in the setting of inflammation and may also be suppressed by MSCT.

Toll like receptor 4: A novel signaling pathway during renal fibrogenesis

PubMed Central

Campbell, Matthew T.; Hile, Karen L; Zhang, Hongji; Asanuma, Hiroshi; Vanderbrink, Brian A.; Rink, Richard R.; Meldrum, Kirstan K.

2010-01-01

Background The toll like receptor (TLR) family serves an important regulatory role in the innate immune system, and recent evidence has implicated TLR signaling in the pro-inflammatory response of a variety of endogenous and exogenous stimuli within the kidney. The role of TLR signaling in fibrotic renal injury; however, remains unknown. Materials and Methods C3H/HeJ TLR4 hyporesponsive mice (TLR4Lps-d) or WT controls (C3H/Heou/J) underwent either sham operation or 1 week of unilateral ureteral obstruction (UUO). The kidneys were harvested and tissues were analyzed for TLR4 expression (Western Blot; RTPCR), E-cadherin and α-SMA expression (Western Blot), fibroblast accumulation (fibroblast specific protein (FSP-1+) staining), renal fibrosis (collagen I RTPCR, total collagen assay, Masson's trichrome staining), cytokine gene expression (tumor necrosis factor-α (TNF-α) and transforming growth factor-beta1 (TGF-β1) RTPCR), and pSMAD2 and integrin α1 expression (Western Blot). Results Mice with intact TLR4 signaling demonstrate a significant increase in TLR4 expression, α-SMA expression, fibroblast accumulation, collagen deposition, and interstitial fibrosis, and a significant decrease in E-cadherin expression in response to UUO. TLR4 deficient mice; however, exhibit a significant reduction in obstruction-induced α-SMA expression, fibroblast accumulation, and renal fibrosis, with preservation of E-cadherin expression. TLR4's influence on fibroblast accumulation and renal fibrosis occurred independent of any alterations in TNF-α,TGF-β1, or pSMAD2 expression, but did involve alterations integrin α1 expression. Conclusion TLR4 appears to be a significant mediator of fibrotic renal injury. While TLR4 signaling is recognized as a critical component of the innate immune response, this is the first study to demonstrate a novel role for TLR4 in renal fibroblast accumulation and tubulointerstitial fibrosis. PMID:20089260

Closed-form expressions for flip angle variation that maximize total signal in T1-weighted rapid gradient echo MRI.

PubMed

Drobnitzky, Matthias; Klose, Uwe

2017-03-01

Magnetization-prepared rapid gradient-echo (MPRAGE) sequences are commonly employed for T1-weighted structural brain imaging. Following a contrast preparation radiofrequency (RF) pulse, the data acquisition proceeds under nonequilibrium conditions of the relaxing longitudinal magnetization. Variation of the flip angle can be used to maximize total available signal. Simulated annealing or greedy algorithms have so far been published to numerically solve this problem, with signal-to-noise ratios optimized for clinical imaging scenarios by adhering to a predefined shape of the signal evolution. We propose an unconstrained optimization of the MPRAGE experiment that employs techniques from resource allocation theory. A new dynamic programming solution is introduced that yields closed-form expressions for optimal flip angle variation. Flip angle series are proposed that maximize total transverse magnetization (Mxy) for a range of physiologic T1 values. A 3D MPRAGE sequence is modified to allow for a controlled variation of the excitation angle. Experiments employing a T1 contrast phantom are performed at 3T. 1D acquisitions without phase encoding permit measurement of the temporal development of Mxy. Image mean signal and standard deviation for reference flip angle trains are compared in 2D measurements. Signal profiles at sharp phantom edges are acquired to access image blurring related to nonuniform Mxy development. A novel closed-form expression for flip angle variation is found that constitutes the optimal policy to reach maximum total signal. It numerically equals previously published results of other authors when evaluated under their simplifying assumptions. Longitudinal magnetization (Mz) is exhaustively used without causing abrupt changes in the measured MR signal, which is a prerequisite for artifact free images. Phantom experiments at 3T verify the expected benefit for total accumulated k-space signal when compared with published flip angle series. Describing the MR signal collection in MPRAGE sequences as a Bellman problem is a new concept. By means of recursively solving a series of overlapping subproblems, this leads to an elegant solution for the problem of maximizing total available MR signal in k-space. A closed-form expression for flip angle variation avoids the complexity of numerical optimization and eases access to controlled variation in an attempt to identify potential clinical applications. © 2017 American Association of Physicists in Medicine.

Inhibition of Wnt/β-Catenin Signaling by a Soluble Collagen-Derived Frizzled Domain Interacting with Wnt3a and the Receptors Frizzled 1 and 8

PubMed Central

Hendaoui, Ismaïl; Lavergne, Elise; Lee, Heun-Sik; Hong, Seong Hyun; Kim, Hak-Zoo; Parent, Christelle; Heuzé-Vourc'h, Nathalie; Clément, Bruno; Musso, Orlando

2012-01-01

The Wnt/β-catenin pathway controls cell proliferation, death and differentiation. Several families of extracellular proteins can antagonize Wnt/β-catenin signaling, including the decoy receptors known as secreted frizzled related proteins (SFRPs), which have a cysteine-rich domain (CRD) structurally similar to the extracellular Wnt-binding domain of the frizzled receptors. SFRPs inhibit Wnt signaling by sequestering Wnts through the CRD or by forming inactive complexes with the frizzled receptors. Other endogenous molecules carrying frizzled CRDs inhibit Wnt signaling, such as V3Nter, which is proteolytically derived from the cell surface component collagen XVIII and contains a biologically active frizzled domain (FZC18) inhibiting in vivo cell proliferation and tumor growth in mice. We recently showed that FZC18 expressing cells deliver short-range signals to neighboring cells, decreasing their proliferation in vitro and in vivo through the Wnt/β-catenin signaling pathway. Here, using low concentrations of soluble FZC18 and Wnt3a, we show that they physically interact in a cell-free system. In addition, soluble FZC18 binds the frizzled 1 and 8 receptors' CRDs, reducing cell sensitivity to Wnt3a. Conversely, inhibition of Wnt/β-catenin signaling was partially rescued by the expression of full-length frizzled 1 and 8 receptors, but enhanced by the expression of a chimeric cell-membrane-tethered frizzled 8 CRD. Moreover, soluble, partially purified recombinant FZC18_CRD inhibited Wnt3a-induced β-catenin activation. Taken together, the data indicate that collagen XVIII-derived frizzled CRD shifts Wnt sensitivity of normal cells to a lower pitch and controls their growth. PMID:22303445

NANOS2 acts downstream of glial cell line-derived neurotrophic factor signaling to suppress differentiation of spermatogonial stem cells.

PubMed

Sada, Aiko; Hasegawa, Kazuteru; Pin, Pui Han; Saga, Yumiko

2012-02-01

Stem cells are maintained by both stem cell-extrinsic niche signals and stem cell-intrinsic factors. During murine spermatogenesis, glial cell line-derived neurotrophic factor (GDNF) signal emanated from Sertoli cells and germ cell-intrinsic factor NANOS2 represent key regulators for the maintenance of spermatogonial stem cells. However, it remains unclear how these factors intersect in stem cells to control their cellular state. Here, we show that GDNF signaling is essential to maintain NANOS2 expression, and overexpression of Nanos2 can alleviate the stem cell loss phenotype caused by the depletion of Gfra1, a receptor for GDNF. By using an inducible Cre-loxP system, we show that NANOS2 expression is downregulated upon the conditional knockout (cKO) of Gfra1, while ectopic expression of Nanos2 in GFRA1-negative spermatogonia does not induce de novo GFRA1 expression. Furthermore, overexpression of Nanos2 in the Gfra1-cKO testes prevents precocious differentiation of the Gfra1-knockout stem cells and partially rescues the stem cell loss phenotypes of Gfra1-deficient mice, indicating that the stem cell differentiation can be suppressed by NANOS2 even in the absence of GDNF signaling. Taken together, we suggest that NANOS2 acts downstream of GDNF signaling to maintain undifferentiated state of spermatogonial stem cells. Copyright © 2011 AlphaMed Press.

Canonical Wnt signaling in megakaryocytes regulates proplatelet formation

PubMed Central

Macaulay, Iain C.; Thon, Jonathan N.; Tijssen, Marloes R.; Steele, Brian M.; MacDonald, Bryan T.; Meade, Gerardene; Burns, Philippa; Rendon, Augusto; Salunkhe, Vishal; Murphy, Ronan P.; Bennett, Cavan; Watkins, Nicholas A.; He, Xi; Fitzgerald, Desmond J.; Italiano, Joseph E.

2013-01-01

Wnt signaling is involved in numerous aspects of vertebrate development and homeostasis, including the formation and function of blood cells. Here, we show that canonical and noncanonical Wnt signaling pathways are present and functional in megakaryocytes (MKs), with several Wnt effectors displaying MK-restricted expression. Using the CHRF288-11 cell line as a model for human MKs, the canonical Wnt3a signal was found to induce a time and dose-dependent increase in β-catenin expression. β-catenin accumulation was inhibited by the canonical antagonist dickkopf-1 (DKK1) and by the noncanonical agonist Wnt5a. Whole genome expression analysis demonstrated that Wnt3a and Wnt5a regulated distinct patterns of gene expression in MKs, and revealed a further interplay between canonical and noncanonical Wnt pathways. Fetal liver cells derived from low-density-lipoprotein receptor-related protein 6-deficient mice (LRP6−/−), generated dramatically reduced numbers of MKs in culture of lower ploidy (2N and 4N) than wild-type controls, implicating LRP6-dependent Wnt signaling in MK proliferation and maturation. Finally, in wild-type mature murine fetal liver-derived MKs, Wnt3a potently induced proplatelet formation, an effect that could be completely abrogated by DKK1. These data identify novel extrinsic regulators of proplatelet formation, and reveal a profound role for Wnt signaling in platelet production. PMID:23160460

Histone deacetylase is required for the activation of Wnt/β-catenin signaling crucial for heart valve formation in zebrafish embryos.

PubMed

Kim, Young-Seop; Kim, Myoung-Jin; Koo, Tae-Hee; Kim, Jun-Dae; Koun, Soonil; Ham, Hyung Jin; Lee, You Mie; Rhee, Myungchull; Yeo, Sang-Yeob; Huh, Tae-Lin

2012-06-22

During vertebrate heart valve formation, Wnt/β-catenin signaling induces BMP signals in atrioventricular canal (AVC) myocardial cells and underlying AVC endocardial cells then undergo endothelial-mesenchymal transdifferentiation (EMT) by receiving this BMP signals. Histone deacetylases (HDACs) have been implicated in numerous developmental processes by regulating gene expression. However, their specific roles in controlling heart valve development are largely unexplored. To investigate the role of HDACs in vertebrate heart valve formation, we treated zebrafish embryos with trichostatin A (TSA), an inhibitor of class I and II HDACs, from 36 to 48 h post-fertilization (hpf) during which heart looping and valve formation occur. Following TSA treatment, abnormal linear heart tube development was observed. In these embryos, expression of AVC myocardial bmp4 and AVC endocardial notch1b genes was markedly reduced with subsequent failure of EMT in the AVC endocardial cells. However, LiCl-mediated activation of Wnt/β-catenin signaling was able to rescue defective heart tube formation, bmp4 and notch1b expression, and EMT in the AVC region. Taken together, our results demonstrated that HDAC activity plays a pivotal role in vertebrate heart tube formation by activating Wnt/β-catenin signaling which induces bmp4 expression in AVC myocardial cells. Copyright © 2012 Elsevier Inc. All rights reserved.

The effect of inhibitory signals on the priming of drug-hapten-specific T-cells that express distinct Vβ receptors

PubMed Central

Gibson, Andrew; Faulkner, Lee; Lichtenfels, Maike; Ogese, Monday; Al-Attar, Zaid; Alfirevic, Ana; Esser, Philipp R.; Martin, Stefan F.; Pirmohamed, Munir; Park, B. Kevin; Naisbitt, Dean J.

2017-01-01

Drug hypersensitivity involves the activation of T-cells in an HLA allele-restricted manner. Since the majority of individuals who carry HLA risk alleles do not develop hypersensitivity, other parameters must control development of the drug-specific T-cell response. Thus, we have utilized a T-cell priming assay and nitroso sulfamethoxazole (SMX-NO) as a model antigen to investigate (1) the activation of specific T-cell receptor (TCR)Vβ subtypes, (2) the impact of PD-1, CTLA4 and TIM-3 co-inhibitory signalling on activation of naïve and memory T-cells and (3) the ability of Tregs to prevent responses. An expansion of the TCR repertoire was observed for nine different Vβ subtypes, while spectratyping revealed that SMX-NO-specific T-cell responses are controlled by public TCRs present in all individuals alongside private TCR repertoires specific to each individual. We proceeded to evaluate the extent to which the activation of these TCR Vβ-restricted antigen-specific T-cell responses is governed by regulatory signals. Blockade of PDL-1/CTLA4 signalling dampened activation of SMX-NO-specific naïve and memory T-cells, while blockade of TIM-3 produced no effect. PD-1, CTLA4, and TIM-3 displayed discrete expression profiles during drug-induced T-cell activation and expression of each receptor was enhanced on dividing T-cells. As these receptors are also expressed on Tregs, Treg-mediated suppression of SMX-NO-induced T-cell activation was investigated. Tregs significantly dampened the priming of T-cells. In conclusion, our findings demonstrate that distinct TCR Vβ subtypes, dysregulation of co-inhibitory signalling pathways and dysfunctional Tregs may influence predisposition to hypersensitivity. PMID:28687658

Epithelial control of gut-associated lymphoid tissue formation through p38α-dependent restraint of NF-κB signaling

PubMed Central

Caballero-Franco, Celia; Guma, Monica; Choo, Min-Kyung; Sano, Yasuyo; Enzler, Thomas; Karin, Michael; Mizoguchi, Atsushi; Park, Jin Mo

2015-01-01

The protein kinase p38α mediates cellular responses to environmental and endogenous cues that direct tissue homeostasis and immune responses. Studies of mice lacking p38α in several different cell types have demonstrated that p38α signaling is essential to maintaining the proliferation-differentiation balance in developing and steady-state tissues. The mechanisms underlying these roles involve cell-autonomous control of signaling and gene expression by p38α. Here we show that p38α regulates gut-associated lymphoid tissue (GALT) formation in a non-cell-autonomous manner. From an investigation of mice with intestinal epithelial cell-specific deletion of the p38α gene, we find that p38α serves to limit NF-κB signaling and thereby attenuate GALT-promoting chemokine expression in the intestinal epithelium. Loss of this regulation results in GALT hyperplasia and, in some animals, mucosa-associated B cell lymphoma. These anomalies occur independently of luminal microbial stimuli and are likely driven by direct epithelial-lymphoid interactions. Our study illustrates a novel p38α-dependent mechanism preventing excessive generation of epithelial-derived signals that drive lymphoid tissue overgrowth and malignancy. PMID:26792803

Custos controls β-catenin to regulate head development during vertebrate embryogenesis.

PubMed

Komiya, Yuko; Mandrekar, Noopur; Sato, Akira; Dawid, Igor B; Habas, Raymond

2014-09-09

Precise control of the canonical Wnt pathway is crucial in embryogenesis and all stages of life, and dysregulation of this pathway is implicated in many human diseases including cancers and birth defect disorders. A key aspect of canonical Wnt signaling is the cytoplasmic to nuclear translocation of β-catenin, a process that remains incompletely understood. Here we report the identification of a previously undescribed component of the canonical Wnt signaling pathway termed Custos, originally isolated as a Dishevelled-interacting protein. Custos contains casein kinase phosphorylation sites and nuclear localization sequences. In Xenopus, custos mRNA is expressed maternally and then widely throughout embryogenesis. Depletion or overexpression of Custos produced defective anterior head structures by inhibiting the formation of the Spemann-Mangold organizer. In addition, Custos expression blocked secondary axis induction by positive signaling components of the canonical Wnt pathway and inhibited β-catenin/TCF-dependent transcription. Custos binds to β-catenin in a Wnt responsive manner without affecting its stability, but rather modulates the cytoplasmic to nuclear translocation of β-catenin. This effect on nuclear import appears to be the mechanism by which Custos inhibits canonical Wnt signaling. The function of Custos is conserved as loss-of-function and gain-of-function studies in zebrafish also demonstrate a role for Custos in anterior head development. Our studies suggest a role for Custos in fine-tuning canonical Wnt signal transduction during embryogenesis, adding an additional layer of regulatory control in the Wnt-β-catenin signal transduction cascade.

Extracellular signal-regulated kinase 1 and 2 are not required for GnRH neuron development and normal female reproductive axis function in mice.

PubMed

Wierman, Margaret E; Xu, Mei; Pierce, A; Bliesner, B; Bliss, S P; Roberson, M S

2012-01-01

Selective deletion of extracellular signal-regulated kinase (ERK) 1 and ERK2 in the pituitary gonadotrope and ovarian granulosa cells disrupts female reproductive axis function. Thus, we asked if ERK1 and ERK2 are critical for GnRH neuron ontogeny or the central control of female reproductive function. GnRH-Cre-recombinase (Cre+) expressing mice were crossed with mice with a global deletion of ERK1 and a floxed ERK2 allele (Erk1-/Erk2fl/fl) to selectively delete ERK2 in GnRH neurons. Cre-recombinase mRNA was selectively expressed in the brain of Cre+ mice. GnRH neuron number and location were determined during embryogenesis and in the adult. GnRH neuron counts at E15 did not differ between experimental and control groups (1,198 ± 65 and 1,160 ± 80 respectively, p = NS). In adults, numbers of GnRH neurons in the GnRHCre+Erk1-/Erk2- mice (741 ± 157) were similar to those in controls (756 ± 7), without alteration in their distribution across the forebrain. ERK1 and 2 deficiency did not alter the timing of vaginal opening, age at first estrus, or estrous cyclicity. Although ERK1 and 2 are components of a dominant signaling pathway in GnRH neuronal cells that modulates survival and control of GnRH gene expression, other signaling pathways compensate for their deletion in vivo to allow GnRH neuron survival and targeting and normal onset of female sexual maturation and reproductive function. In contrast to effects at the pituitary and the ovary, ERK1 and ERK2 are dispensable at the level of the GnRH neuron. Copyright © 2011 S. Karger AG, Basel.

Stress-response transcription factors Msn2 and Msn4 couple TORC2-Ypk1 signaling and mitochondrial respiration to ATG8 gene expression and autophagy.

PubMed

Vlahakis, Ariadne; Lopez Muniozguren, Nerea; Powers, Ted

2017-01-01

Macroautophagy/autophagy is a starvation and stress-induced catabolic process critical for cellular homeostasis and adaptation. Several Atg proteins are involved in the formation of the autophagosome and subsequent degradation of cytoplasmic components, a process termed autophagy flux. Additionally, the expression of several Atg proteins, in particular Atg8, is modulated transcriptionally, yet the regulatory mechanisms involved remain poorly understood. Here we demonstrate that the AGC kinase Ypk1, target of the rapamycin-insensitive TORC2 signaling pathway, controls ATG8 expression by repressing the heterodimeric Zinc-finger transcription factors Msn2 and Msn4. We find that Msn2 and Msn4 promote ATG8 expression downstream of the histone deacetylase complex (HDAC) subunit Ume6, a previously identified negative regulator of ATG8 expression. Moreover, we demonstrate that TORC2-Ypk1 signaling is functionally linked to distinct mitochondrial respiratory complexes. Surprisingly, we find that autophagy flux during amino acid starvation is also dependent upon Msn2-Msn4 activity, revealing a broad role for these transcription factors in the autophagy response.

Secretory Overexpression of Bacillus thermocatenulatus Lipase in Saccharomyces cerevisiae Using Combinatorial Library Strategy.

PubMed

Kajiwara, Shota; Yamada, Ryosuke; Ogino, Hiroyasu

2018-04-10

Simple and cost-effective lipase expression host microorganisms are highly desirable. A combinatorial library strategy is used to improve the secretory expression of lipase from Bacillus thermocatenulatus (BTL2) in the culture supernatant of Saccharomyces cerevisiae. A plasmid library including expression cassettes composed of sequences encoding one of each 15 promoters, 15 secretion signals, and 15 terminators derived from yeast species, S. cerevisiae, Pichia pastoris, and Hansenula polymorpha, is constructed. The S. cerevisiae transformant YPH499/D4, comprising H. polymorpha GAP promoter, S. cerevisiae SAG1 secretion signal, and P. pastoris AOX1 terminator, is selected by high-throughput screening. This transformant expresses BTL2 extra-cellularly with a 130-fold higher than the control strain, comprising S. cerevisiae PGK1 promoter, S. cerevisiae α-factor secretion signal, and S. cerevisiae PGK1 terminator, after cultivation for 72 h. This combinatorial library strategy holds promising potential for application in the optimization of the secretory expression of proteins in yeast. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Secretory expression of nattokinase from Bacillus subtilis YF38 in Escherichia coli.

PubMed

Liang, Xiaobo; Jia, Shifang; Sun, Yufang; Chen, Meiling; Chen, Xiuzhu; Zhong, Jin; Huan, Liandong

2007-11-01

Nattokinase producing bacterium, B. subtilis YF38, was isolated from douchi, using the fibrin plate method. The gene encoding this enzyme was cloned by polymerase chain reaction (PCR). Cytoplasmic expression of this enzyme in E. coli resulted in inactive inclusion bodies. But with the help of two different signal peptides, the native signal peptide of nattokinase and the signal peptide of PelB, active nattokinase was successfully expressed in E. coli with periplasmic secretion, and the nattokinase in culture medium displayed high fibrinolytic activity. The fibrinolytic activity of the expressed enzyme in the culture was determined to reach 260 urokinase units per micro-liter when the recombinant strain was induced by 0.7 mmol l(-1) isopropyl-beta-D- thiogalactopyranoside (IPTG) at 20 degrees C for 20 h, resulting 49.3 mg active enzyme per liter culture. The characteristic of this recombinant nattokinase is comparable to the native nattokinase from B. subtilis YF38. Secretory expression of nattokinase in E. coli would facilitate the development of this enzyme into a therapeutic product for the control and prevention of thrombosis diseases.

Crossroads of Wnt and Hippo in epithelial tissues.

PubMed

Bernascone, Ilenia; Martin-Belmonte, Fernando

2013-08-01

Epithelial tissues undergo constant growth and differentiation during embryonic development and to replace damaged tissue in adult organs. These processes are governed by different signaling pathways that ultimately control the expression of genes associated with cell proliferation, patterning, and death. One essential pathway is Wnt, which controls tubulogenesis in several epithelial organs. Recently, Wnt has been closely linked to other signaling pathways, such as Hippo, that orchestrate proliferation and apoptosis to control organ size. There is evidence that epithelial cell junctions may sequester the transcription factors that act downstream of these signaling pathways, which would represent an important aspect of their functional regulation and their influence on cell behavior. Here, we review the transcriptional control exerted by the Wnt and Hippo signaling pathways during epithelial growth, patterning, and differentiation and recent advances in understanding of the regulation and crosstalk of these pathways in epithelial tissues. Copyright © 2013 Elsevier Ltd. All rights reserved.

Revisiting the X:A signal that specifies Caenorhabditis elegans sexual fate.

PubMed

Gladden, John M; Farboud, Behnom; Meyer, Barbara J

2007-11-01

In Caenorhabditis elegans, sex is determined by the opposing actions of X-signal elements (XSEs) and autosomal signal elements (ASEs), which communicate the ratio of X chromosomes to sets of autosomes (X:A signal). This study delves more deeply into the mechanism by which XSEs transmit X chromosome dose. We determined the relative contributions of individual XSEs to the X:A signal and showed the order of XSE strength to be sex-1 > sex-2 > fox-1 > ceh-39 >/= region 1 XSE. sex-1 exerts a more potent influence on sex determination and dosage compensation than any other XSE by functioning in two separate capacities in the pathway: sex-1 acts upstream as an XSE to repress xol-1 and downstream as an activator of hermaphrodite development and dosage compensation. Furthermore, the process of dosage compensation affects expression of the very XSEs that control it; XSEs become fully dosage compensated once sex is determined. The X:A signal is then equivalent between XO and XX animals, causing sexual differentiation to be controlled by genes downstream of xol-1 in the sex-determination pathway. Prior to the onset of dosage compensation, the difference in XSE expression between XX and XO embryos appears to be greater than twofold, making X chromosome counting a robust process.

Fibroblast growth factor (Fgf) signaling pathway regulates liver homeostasis in zebrafish.

PubMed

Tsai, Su-Mei; Liu, Da-Wei; Wang, Wen-Pin

2013-04-01

In mammals, fibroblast growth factor (FGF) signaling controls liver specification and regulates the metabolism of lipids, cholesterol, and bile acids. FGF signaling also promotes hepatocyte proliferation, and helps detoxify hepatotoxin during liver regeneration after partial hepatectomy. However, the function of Fgf in zebrafish liver is not yet well understood, specifically for postnatal homeostasis. The current study analyzed the expression of fgf receptors (fgfrs) in the liver of zebrafish. We then investigated the function of Fgf signaling in the zebrafish liver by expressing a dominant-negative Fgf receptor in hepatocytes (lfabp:dnfgfr1-egfp, lf:dnfr). Histological analysis showed that our genetic intervention resulted in a small liver size with defected medial expansion of developing livers in transgenic (Tg) larvae. Morphologically, the liver lobe of lf:dnfr adult fish was shorter than that of control. Ballooning degeneration of hepatocytes was observed in fish as young as 3 months. Further examination revealed the development of hepatic steatosis and cholestasis. In adult Tg fish, we unexpectedly observed increased liver-to-body-weight ratios, with higher percentages of proliferating hepatocytes. Considering all these findings, we concluded that as in mammals, in adult zebrafish the metabolism of lipid and bile acids in the liver are regulated by Fgf signaling. Disruption of the Fgf signal-mediated metabolism might indirectly affect hepatocyte proliferation.

CAR T cell therapy for breast cancer: harnessing the tumor milieu to drive T cell activation.

PubMed

Bajgain, Pradip; Tawinwung, Supannikar; D'Elia, Lindsey; Sukumaran, Sujita; Watanabe, Norihiro; Hoyos, Valentina; Lulla, Premal; Brenner, Malcolm K; Leen, Ann M; Vera, Juan F

2018-05-10

The adoptive transfer of T cells redirected to tumor via chimeric antigen receptors (CARs) has produced clinical benefits for the treatment of hematologic diseases. To extend this approach to breast cancer, we generated CAR T cells directed against mucin1 (MUC1), an aberrantly glycosylated neoantigen that is overexpressed by malignant cells and whose expression has been correlated with poor prognosis. Furthermore, to protect our tumor-targeted cells from the elevated levels of immune-inhibitory cytokines present in the tumor milieu, we co-expressed an inverted cytokine receptor linking the IL4 receptor exodomain with the IL7 receptor endodomain (4/7ICR) in order to transform the suppressive IL4 signal into one that would enhance the anti-tumor effects of our CAR T cells at the tumor site. First (1G - CD3ζ) and second generation (2G - 41BB.CD3ζ) MUC1-specific CARs were constructed using the HMFG2 scFv. Following retroviral transduction transgenic expression of the CAR±ICR was assessed by flow cytometry. In vitro CAR/ICR T cell function was measured by assessing cell proliferation and short- and long-term cytotoxic activity using MUC1+ MDA MB 468 cells as targets. In vivo anti-tumor activity was assessed using IL4-producing MDA MB 468 tumor-bearing mice using calipers to assess tumor volume and bioluminescence imaging to track T cells. In the IL4-rich tumor milieu, 1G CAR.MUC1 T cells failed to expand or kill MUC1+ tumors and while co-expression of the 4/7ICR promoted T cell expansion, in the absence of co-stimulatory signals the outgrowing cells exhibited an exhausted phenotype characterized by PD-1 and TIM3 upregulation and failed to control tumor growth. However, by co-expressing 2G CAR.MUC1 (signal 1 - activation + signal 2 - co-stimulation) and 4/7ICR (signal 3 - cytokine), transgenic T cells selectively expanded at the tumor site and produced potent and durable tumor control in vitro and in vivo. Our findings demonstrate the feasibility of targeting breast cancer using transgenic T cells equipped to thrive in the suppressive tumor milieu and highlight the importance of providing transgenic T cells with signals that recapitulate physiologic TCR signaling - [activation (signal 1), co-stimulation (signal 2) and cytokine support (signal 3)] - to promote in vivo persistence and memory formation.

The Kto-Skd complex can regulate ptc expression by interacting with Cubitus interruptus (Ci) in the Hedgehog signaling pathway.

PubMed

Mao, Feifei; Yang, Xiaofeng; Fu, Lin; Lv, Xiangdong; Zhang, Zhao; Wu, Wenqing; Yang, Siqi; Zhou, Zhaocai; Zhang, Lei; Zhao, Yun

2014-08-08

The hedgehog (Hh) signaling pathway plays a very important role in metazoan development by controlling pattern formation. Drosophila imaginal discs are subdivided into anterior and posterior compartments that derive from adjacent cell populations. The anterior/posterior (A/P) boundaries, which are critical to maintaining the position of organizers, are established by a complex mechanism involving Hh signaling. Here, we uncover the regulation of ptc in the Hh signaling pathway by two subunits of mediator complex, Kto and Skd, which can also regulate boundary location. Collectively, we provide further evidence that Kto-Skd affects the A/P-axial development of the whole wing disc. Kto can interact with Cubitus interruptus (Ci), bind to the Ci-binding region on ptc promoter, which are both regulated by Hh signals to down-regulate ptc expression. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Expansion of banana (Musa acuminata) gene families involved in ethylene biosynthesis and signalling after lineage-specific whole-genome duplications.

PubMed

Jourda, Cyril; Cardi, Céline; Mbéguié-A-Mbéguié, Didier; Bocs, Stéphanie; Garsmeur, Olivier; D'Hont, Angélique; Yahiaoui, Nabila

2014-05-01

Whole-genome duplications (WGDs) are widespread in plants, and three lineage-specific WGDs occurred in the banana (Musa acuminata) genome. Here, we analysed the impact of WGDs on the evolution of banana gene families involved in ethylene biosynthesis and signalling, a key pathway for banana fruit ripening. Banana ethylene pathway genes were identified using comparative genomics approaches and their duplication modes and expression profiles were analysed. Seven out of 10 banana ethylene gene families evolved through WGD and four of them (1-aminocyclopropane-1-carboxylate synthase (ACS), ethylene-insensitive 3-like (EIL), ethylene-insensitive 3-binding F-box (EBF) and ethylene response factor (ERF)) were preferentially retained. Banana orthologues of AtEIN3 and AtEIL1, two major genes for ethylene signalling in Arabidopsis, were particularly expanded. This expansion was paralleled by that of EBF genes which are responsible for control of EIL protein levels. Gene expression profiles in banana fruits suggested functional redundancy for several MaEBF and MaEIL genes derived from WGD and subfunctionalization for some of them. We propose that EIL and EBF genes were co-retained after WGD in banana to maintain balanced control of EIL protein levels and thus avoid detrimental effects of constitutive ethylene signalling. In the course of evolution, subfunctionalization was favoured to promote finer control of ethylene signalling. © 2014 CIRAD New Phytologist © 2014 New Phytologist Trust.

miR-126 contributes to Parkinson disease by dysregulating IGF-1/PI3K signaling

PubMed Central

Kim, Woori; Lee, Yenarae; McKenna, Noah D.; Yi, Ming; Simunovic, Filip; Wang, Yulei; Kong, Benjamin; Rooney, Robert J.; Seo, Hyemyung; Stephens, Robert; Sonntag, Kai C.

2014-01-01

Dopamine (DA) neurons in sporadic Parkinson disease (PD) display dysregulated gene expression networks and signaling pathways that are implicated in PD pathogenesis. Micro (mi)RNAs are regulators of gene expression, which could be involved in neurodegenerative diseases. We determined the miRNA profiles in laser microdissected DA neurons from postmortem sporadic PD patients’ brains and age-matched controls. DA neurons had a distinctive miRNA signature and a set of miRNAs was dysregulated in PD. Bioinformatics analysis provided evidence for correlations of miRNAs with signaling pathways relevant to PD, including an association of miR-126 with insulin/IGF-1/PI3K signaling. In DA neuronal cell systems, enhanced expression of miR-126 impaired IGF-1 signaling and increased vulnerability to the neurotoxin 6-OHDA by downregulating factors in IGF-1/PI3K signaling, including its targets p85β, IRS-1, and SPRED1. Blocking of miR-126 function increased IGF-1 trophism and neuroprotection to 6-OHDA. Our data imply that elevated levels of miR-126 may play a functional role in DA neurons and in PD pathogenesis by downregulating IGF-1/PI3K/AKT signaling and that its inhibition could be a mechanism of neuroprotection. PMID:24559646

House dust mite-specific immunotherapy alters the basal expression of T regulatory and FcεRI pathway genes.

PubMed

Pevec, Branko; Radulovic Pevec, Mira; Stipic Markovic, Asja; Batista, Irena; Rijavec, Matija; Silar, Mira; Kosnik, Mitja; Korosec, Peter

2012-01-01

Regulatory T (Treg) cells and IgE-mediated signaling pathways could play important roles in the induction of allergen tolerance during house dust mite-specific subcutaneous immunotherapy (HDM-SCIT). Our aim was to compare the basal expression levels of Treg, T helper 1 (Th1) and Th2 transcription factors and components involved in IgE-mediated signaling in healthy subjects with those in HDM-allergic patients both untreated and successfully treated with HDM-SCIT. Thirty-nine HDM-allergic patients who completed a 3- to 5-year course of mite extract SCIT, 20 mite-allergic controls and 25 healthy controls participated in this study. The efficacy of SCIT was monitored using skin-prick tests (SPTs), total immunoglobulin E (tIgE), specific IgE (sIgE), sIgG(4), nasal challenge and visual analog scale (VAS) scores at several time points. The mRNA levels of forkhead box protein 3 (FOXP3), T-BET, GATA-3, FcεRI, spleen tyrosine kinase (Syk), phosphatidylinositol 3 kinase (PI3K) and SH2 domain-containing inositol phosphatase (SHIP) were quantified by real-time RT-PCR using nonstimulated whole blood samples. Decreased wheal sizes and VAS scores, negative challenges and increased sIgG(4) levels indicated that SCIT was effective in the treated patients. Basal expression levels of FOXP3 and GATA-3 decreased and T-BET levels increased in both treated patients and in healthy controls compared to untreated patients. The IgE-mediated pathway kinases Syk and PI3K exhibited reduced expression, whereas SHIP phosphatase levels were elevated in both treated patients and healthy controls relative to untreated patients. The expression levels of FcεRI were not significantly altered. Immunotherapy using HDM extracts results in a modification of the basal expression levels of several IgE-related signaling factors and induces a highly significant upregulation of Th1-response and downregulation of Th2-response transcription factors. Interestingly, this therapy also appears to reduce the basal expression of FOXP3. Copyright © 2012 S. Karger AG, Basel.

Prenatal exposure to lambda-cyhalothrin alters brain dopaminergic signaling in developing rats.

PubMed

Dhuriya, Yogesh K; Srivastava, Pranay; Shukla, Rajendra K; Gupta, Richa; Singh, Dhirendra; Parmar, Devendra; Pant, Aditya B; Khanna, Vinay K

2017-07-01

The present study is focused to decipher the molecular mechanisms associated with dopaminergic alterations in corpus striatum of developing rats exposed prenatally to lambda-cyhalothrin (LCT), a new generation type II synthetic pyrethroid. There was no significant change in the mRNA and protein expression of DA-D1 receptors at any of the doses of LCT (0.5, 1 and 3mg/kg body weight) in corpus striatum of developing rats exposed prenatally to LCT on PD22 and PD45. Prenatal exposure to LCT (1 and 3mg/kg body weight) resulted to decrease the levels of mRNA and protein of DA-D2 receptors in corpus stratum of developing rats on PD22 as compared to controls. Decrease in the binding of 3H-Spiperone in corpus striatum, known to label DA-D2 receptors was also distinct in developing rats on PD22. These rats also exhibited decrease in the expression of proteins - TH, DAT and VMAT2 involved in pre-dopaminergic signaling. Further, decrease in the expression of DARPP-32 and pCREB associated with increased expression of PP1α was evident in developing rats on PD22 as compared to controls. Interestingly, a trend of recovery in the expression of these proteins was observed in developing rats exposed to LCT at moderate dose (1.0mg/kg body weight) while alteration in the expression of these proteins continued to persist in those exposed at high dose (3.0mg/kg body weight) on PD45 as compared to respective controls. No significant change in the expression of any of these proteins was observed in corpus striatum of developing rats prenatally exposed to LCT at low dose (0.5mg/kg body weight) on PD22 and PD45 as compared to respective controls. The results provide interesting evidence that alterations in dopaminergic signaling on LCT exposure are due to selective changes in DA-D2 receptors in corpus striatum of developing rats. Further, these changes could be attributed to impairment in spontaneous motor activity on LCT exposure in developing rats. Copyright © 2017 Elsevier B.V. All rights reserved.

Regulation of cytokine signaling by B cell antigen receptor and CD40-controlled expression of heparan sulfate proteoglycans.

PubMed

van der Voort, R; Keehnen, R M; Beuling, E A; Spaargaren, M; Pals, S T

2000-10-16

Recently, biochemical, cell biological, and genetic studies have converged to reveal that integral membrane heparan sulfate proteoglycans (HSPGs) are critical regulators of growth and differentiation of epithelial and connective tissues. As a large number of cytokines involved in lymphoid tissue homeostasis or inflammation contain potential HS-binding domains, HSPGs presumably also play important roles in the regulation of the immune response. In this report, we explored the expression, regulation, and function of HSPGs on B lymphocytes. We demonstrate that activation of the B cell antigen receptor (BCR) and/or CD40 induces a strong transient expression of HSPGs on human tonsillar B cells. By means of these HSPGs, the activated B cells can bind hepatocyte growth factor (HGF), a cytokine that regulates integrin-mediated B cell adhesion and migration. This interaction with HGF is highly selective since the HSPGs did not bind the chemokine stromal cell-derived factor (SDF)-1 alpha, even though the affinities of HGF and SDF-1alpha for heparin are similar. On the activated B cells, we observed induction of a specific HSPG isoform of CD44 (CD44-HS), but not of other HSPGs such as syndecans or glypican-1. Interestingly, the expression of CD44-HS on B cells strongly promotes HGF-induced signaling, resulting in an HS-dependent enhanced phosphorylation of Met, the receptor tyrosine kinase for HGF, as well as downstream signaling molecules including Grb2-associated binder 1 (Gab1) and Akt/protein kinase B (PKB). Our results demonstrate that the BCR and CD40 control the expression of HSPGs, specifically CD44-HS. These HSPGs act as functional coreceptors that selectively promote cytokine signaling in B cells, suggesting a dynamic role for HSPGs in antigen-specific B cell differentiation.

Transforming growth factor-β-mediated CD44/STAT3 signaling contributes to the development of atrial fibrosis and fibrillation.

PubMed

Chang, Shang-Hung; Yeh, Yung-Hsin; Lee, Jia-Lin; Hsu, Yu-Juei; Kuo, Chi-Tai; Chen, Wei-Jan

2017-09-04

Atrial fibrillation (AF) is associated with atrial fibrosis. Inhibition of atrial fibrosis might be a plausible approach for AF prevention and therapy. This study is designed to evaluate the potential role of CD44, a membrane receptor known to regulate fibrosis, and its related signaling in the pathogenesis of atrial fibrosis and AF. Treatment of cultured rat atrial fibroblasts with transforming growth factor-β (TGF-β, a key mediator of atrial fibrosis) led to a higher expression of hyaluronan (HA), CD44, STAT3, and collagen (a principal marker of fibrosis) than that of ventricular fibroblasts. In vivo, TGF-β transgenic mice and AF patients exhibited a greater expression of HA, CD44, STAT3, and collagen in their atria than wild-type mice and sinus rhythm subjects, respectively. Treating TGF-β transgenic mice with an anti-CD44 blocking antibody resulted in a lower expression of STAT3 and collagen in their atria than those with control IgG antibody. Programmed stimulation triggered less AF episodes in TGF-β transgenic mice treated with anti-CD44 blocking antibody than in those with control IgG. Blocking CD44 signaling with anti-CD44 antibody and mutated CD44 plasmids attenuated TGF-β-induced STAT3 activation and collagen expression in cultured atrial fibroblasts. Deletion and mutational analysis of the collagen promoter along with chromatin immunoprecipitation demonstrated that STAT3 served as a vital transcription factor in collagen expression. TGF-β-mediated HA/CD44/STAT3 pathway plays a crucial role in the development of atrial fibrosis and AF. Blocking CD44-dependent signaling may be a feasible way for AF management.

NR4A orphan nuclear receptors influence retinoic acid and docosahexaenoic acid signaling via up-regulation of fatty acid binding protein 5

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

Volakakis, Nikolaos; Joodmardi, Eliza; Perlmann, Thomas, E-mail: thomas.perlmann@licr.ki.se

2009-12-25

The orphan nuclear receptor (NR) Nurr1 is expressed in the developing and adult nervous system and is also induced as an immediate early gene in a variety of cell types. In silico analysis of human promoters identified fatty acid binding protein 5 (FABP5), a protein shown to enhance retinoic acid-mediated PPAR{beta}/{delta} signaling, as a potential Nurr1 target gene. Nurr1 has previously been implicated in retinoid signaling via its heterodimerization partner RXR. Since NRs are commonly involved in cross-regulatory control we decided to further investigate the regulatory relationship between Nurr1 and FABP5. FABP5 expression was up-regulated by Nurr1 and other NR4Amore » NRs in HEK293 cells, and Nurr1 was shown to activate and bind to the FABP5 promoter, supporting that FABP5 is a direct downstream target of NR4A NRs. We also show that the RXR ligand docosahexaenoic acid (DHA) can induce nuclear translocation of FABP5. Moreover, via up-regulation of FABP5 Nurr1 can enhance retinoic acid-induced signaling of PPAR{beta}/{delta} and DHA-induced activation of RXR. We also found that other members of the NR4A orphan NRs can up-regulate FABP5. Thus, our findings suggest that NR4A orphan NRs can influence signaling events of other NRs via control of FABP5 expression levels.« less

The Arabidopsis LAZY1 Family Plays a Key Role in Gravity Signaling within Statocytes and in Branch Angle Control of Roots and Shoots[OPEN

PubMed Central

Taniguchi, Masatoshi; Furutani, Masahiko; Nishimura, Takeshi; Nakamura, Moritaka; Fushita, Toyohito; Iijima, Kohta; Baba, Kenichiro; Toyota, Masatsugu

2017-01-01

During gravitropism, the directional signal of gravity is perceived by gravity-sensing cells called statocytes, leading to asymmetric distribution of auxin in the responding organs. To identify the genes involved in gravity signaling in statocytes, we performed transcriptome analyses of statocyte-deficient Arabidopsis thaliana mutants and found two candidates from the LAZY1 family, AtLAZY1/LAZY1-LIKE1 (LZY1) and AtDRO3/AtNGR1/LZY2. We showed that LZY1, LZY2, and a paralog AtDRO1/AtNGR2/LZY3 are redundantly involved in gravitropism of the inflorescence stem, hypocotyl, and root. Mutations of LZY genes affected early processes in gravity signal transduction without affecting amyloplast sedimentation. Statocyte-specific expression of LZY genes rescued the mutant phenotype, suggesting that LZY genes mediate gravity signaling in statocytes downstream of amyloplast displacement, leading to the generation of asymmetric auxin distribution in gravity-responding organs. We also found that lzy mutations reversed the growth angle of lateral branches and roots. Moreover, expression of the conserved C-terminal region of LZY proteins also reversed the growth direction of primary roots in the lzy mutant background. In lateral root tips of lzy multiple mutants, asymmetric distribution of PIN3 and auxin response were reversed, suggesting that LZY genes regulate the direction of polar auxin transport in response to gravity through the control of asymmetric PIN3 expression in the root cap columella. PMID:28765510

BMP Signaling and Podocyte Markers Are Decreased in Human Diabetic Nephropathy in Association With CTGF Overexpression

PubMed Central

Turk, Tamara; Leeuwis, Jan Willem; Gray, Julia; Torti, Suzy V.; Lyons, Karen M.; Nguyen, Tri Q.; Goldschmeding, Roel

2009-01-01

Diabetic nephropathy is characterized by decreased expression of bone morphogenetic protein-7 (BMP-7) and decreased podocyte number and differentiation. Extracellular antagonists such as connective tissue growth factor (CTGF; CCN-2) and sclerostin domain-containing-1 (SOSTDC1; USAG-1) are important determinants of BMP signaling activity in glomeruli. We studied BMP signaling activity in glomeruli from diabetic patients and non-diabetic individuals and from control and diabetic CTGF+/+ and CTGF+/− mice. BMP signaling activity was visualized by phosphorylated Smad1, -5, and -8 (pSmad1/5/8) immunostaining, and related to expression of CTGF, SOSTDC1, and the podocyte differentiation markers WT1, synaptopodin, and nephrin. In control and diabetic glomeruli, pSmad1/5/8 was mainly localized in podocytes, but both number of positive cells and staining intensity were decreased in diabetes. Nephrin and synaptopodin were decreased in diabetic glomeruli. Decrease of pSmad1/5/8 was only partially explained by decrease in podocyte number. SOSTDC1 and CTGF were expressed exclusively in podocytes. In diabetic glomeruli, SOSTDC1 decreased in parallel with podocyte number, whereas CTGF was strongly increased. In diabetic CTGF+/− mice, pSmad1/5/8 was preserved, compared with diabetic CTGF+/+ mice. In conclusion, in human diabetic nephropathy, BMP signaling activity is diminished, together with reduction of podocyte markers. This might relate to concomitant overexpression of CTGF but not SOSTDC1. (J Histochem Cytochem 57:623–631, 2009) PMID:19255250

Serum miRNAs Signature Plays an Important Role in Keloid Disease.

PubMed

Luan, Y; Liu, Y; Liu, C; Lin, Q; He, F; Dong, X; Xiao, Z

2016-01-01

The molecular mechanism underlying the pathogenesis of keloid is largely unknown. MicroRNA (miRNA) is a class of small regulatory RNA that has emerged as a group of posttranscriptional gene repressors, participating in diverse pathophysiological processes of skin diseases. We investigated the expression profiles of miRNAs in the sera of patients to decipher the complicated factors involved in the development of keloid disease. MiRNA expression profiling in the sera from 9 keloid patients and 7 normal controls were characterized using a miRNA microarray containing established human mature and precursor miRNA sequences. Quantitative real-time PCR was performed to confirm the expression of miRNAs. The putative targets of differentially expressed miRNAs were functionally annotated by bioinformatics. MiRNA microarray analysis identified 37 differentially expressed miRNAs (17 upregulated and 20 downregulated) in keloid patients, compared to the healthy controls. Functional annotations revealed that the targets of those differentially expressed miRNAs were enriched in signaling pathways essential for scar formation and wound healing. The expression profiling of miRNAs is altered in the keloid, providing a clue for the molecular mechanisms underlying its initiation and progression. MiRNAs may partly contribute to the etiology of keloids by affecting the critical signaling pathways relevant to keloid pathogenesis.

Gene expression profiling reveals different molecular patterns in G-protein coupled receptor signaling pathways between early- and late-onset preeclampsia.

PubMed

Liang, Mengmeng; Niu, Jianmin; Zhang, Liang; Deng, Hua; Ma, Jian; Zhou, Weiping; Duan, Dongmei; Zhou, Yuheng; Xu, Huikun; Chen, Longding

2016-04-01

Early-onset preeclampsia and late-onset preeclampsia have been regarded as two different phenotypes with heterogeneous manifestations; To gain insights into the pathogenesis of the two traits, we analyzed the gene expression profiles in preeclamptic placentas. A whole genome-wide microarray was used to determine the gene expression profiles in placental tissues from patients with early-onset (n = 7; <34 weeks), and late-onset (n = 8; >36 weeks) preeclampsia and their controls who delivered preterm (n = 5; <34 weeks) or at term (n = 5; >36 weeks). Genes were termed differentially expressed if they showed a fold-change ≥ 2 and q-value < 0.05. Quantitative real-time reverse transcriptase PCR was used to verify the results. Western blotting was performed to verify the expressions of secreted genes at the protein level. Six hundred twenty-seven genes were differentially expressed in early-compared with late-onset preeclampsia (177 genes were up-regulated and 450 were down-regulated). Gene ontology analysis identified significant alterations in several biological processes; the top two were immune response and cell surface receptor linked signal transduction. Among the cell surface receptor linked signal transduction-related, differentially expressed genes, those involved in the G-protein coupled receptor protein signaling pathway were significantly enriched. G-protein coupled receptor signaling pathway related genes, such as GPR124 and MRGPRF, were both found to be down-regulated in early-onset preeclampsia. The results were consistent with those of western blotting that the abundance of GPR124 was lower in early-onset compared with late-onset preeclampsia. The different gene expression profiles reflect the different levels of transcription regulation between the two conditions and supported the hypothesis that they are separate disease entities. Moreover, the G-protein coupled receptor signaling pathway related genes may contribute to the mechanism underlying early- and late-onset preeclampsia. Copyright © 2016 Elsevier Ltd. All rights reserved.

WNT signaling controls expression of pro-apoptotic BOK and BAX in intestinal cancer

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

Zeilstra, Jurrit; Joosten, Sander P.J.; Wensveen, Felix M.

Research highlights: {yields} Intestinal adenomas initiated by aberrant activation of the WNT pathway displayed an increased sensitivity to apoptosis. {yields} Expression profiling of apoptosis-related genes in Apc{sup Min/+} mice revealed the differential expression of pro-apoptotic Bok and Bax. {yields} APC-mutant adenomatous crypts in FAP patients showed strongly increased BAX immunoreactivity. {yields} Blocking of {beta}-catenin/TCF-4-mediated signaling in colon cancer cells reduced the expression of BOK and BAX. -- Abstract: In a majority of cases, colorectal cancer is initiated by aberrant activation of the WNT signaling pathway. Mutation of the genes encoding the WNT signaling components adenomatous polyposis coli or {beta}-catenin causesmore » constitutively active {beta}-catenin/TCF-mediated transcription, driving the transformation of intestinal crypts to cancer precursor lesions, called dysplastic aberrant crypt foci. Deregulated apoptosis is a hallmark of adenomatous colon tissue. However, the contribution of WNT signaling to this process is not fully understood. We addressed this role by analyzing the rate of epithelial apoptosis in aberrant crypts and adenomas of the Apc{sup Min/+} mouse model. In comparison with normal crypts and adenomas, aberrant crypts displayed a dramatically increased rate of apoptotic cell death. Expression profiling of apoptosis-related genes along the crypt-villus axis and in Apc mutant adenomas revealed increased expression of two pro-apoptotic Bcl-2 family members in intestinal adenomas, Bok and Bax. Analysis of the colon of familial adenomatous polyposis (FAP) patients along the crypt-to-surface axis, and of dysplastic crypts, corroborated this expression pattern. Disruption of {beta}-catenin/TCF-4-mediated signaling in the colorectal cancer cell line Ls174T significantly decreased BOK and BAX expression, confirming WNT-dependent regulation in intestinal epithelial cells. Our results suggest a feedback mechanism by which uncontrolled epithelial cell proliferation in the stem cell compartment can be counterbalanced by an increased propensity to undergo cell death.« less

Assessing the osteoblast transcriptome in a model of enhanced bone formation due to constitutive G{sub s}–G protein signaling in osteoblasts

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

Wattanachanya, Lalita, E-mail: lalita_md@yahoo.com; Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok; Wang, Liping, E-mail: lipingwang05@yahoo.com

G protein-coupled receptor (GPCR) signaling in osteoblasts (OBs) is an important regulator of bone formation. We previously described a mouse model expressing Rs1, an engineered constitutively active G{sub s}-coupled GPCR, under the control of the 2.3 kb Col I promoter. These mice showed a dramatic age-dependent increase in trabecular bone of femurs. Here, we further evaluated the effects of enhanced G{sub s} signaling in OBs on intramembranous bone formation by examining calvariae of 1- and 9-week-old Col1(2.3)/Rs1 mice and characterized the in vivo gene expression specifically occurring in osteoblasts with activated G{sub s} G protein-coupled receptor signaling, at the cellularmore » level rather than in a whole bone. Rs1 calvariae displayed a dramatic increase in bone volume with partial loss of cortical structure. By immunohistochemistry, Osterix was detected in cells throughout the inter-trabecular space while Osteocalcin was expressed predominantly in cells along bone surfaces, suggesting the role of paracrine mediators secreted from OBs driven by 2.3 kb Col I promoter could influence early OB commitment, differentiation, and/or proliferation. Gene expression analysis of calvarial OBs revealed that genes affected by Rs1 signaling include those encoding proteins important for cell differentiation, cytokines and growth factors, angiogenesis, coagulation, and energy metabolism. The set of G{sub s}-GPCRs and other GPCRs that may contribute to the observed skeletal phenotype and candidate paracrine mediators of the effect of G{sub s} signaling in OBs were also determined. Our results identify novel detailed in vivo cellular changes of the anabolic response of the skeleton to G{sub s} signaling in mature OBs. - Highlights: • OB expression of an engineered G{sub s}-coupled receptor dramatically increases bone mass. • We investigated the changes in gene expression in vivo in enhanced OB G{sub s} signaling. • Genes in cell cycle and transcription were increased in enhanced OB G{sub s} signaling. • GPCRs and paracrine mediators of the effect of G{sub s} signaling in OBs were determined.« less

Spatiotemporal control of opioid signaling and behavior.

PubMed

Siuda, Edward R; Copits, Bryan A; Schmidt, Martin J; Baird, Madison A; Al-Hasani, Ream; Planer, William J; Funderburk, Samuel C; McCall, Jordan G; Gereau, Robert W; Bruchas, Michael R

2015-05-20

Optogenetics is now a widely accepted tool for spatiotemporal manipulation of neuronal activity. However, a majority of optogenetic approaches use binary on/off control schemes. Here, we extend the optogenetic toolset by developing a neuromodulatory approach using a rationale-based design to generate a Gi-coupled, optically sensitive, mu-opioid-like receptor, which we term opto-MOR. We demonstrate that opto-MOR engages canonical mu-opioid signaling through inhibition of adenylyl cyclase, activation of MAPK and G protein-gated inward rectifying potassium (GIRK) channels and internalizes with kinetics similar to that of the mu-opioid receptor. To assess in vivo utility, we expressed a Cre-dependent viral opto-MOR in RMTg/VTA GABAergic neurons, which led to a real-time place preference. In contrast, expression of opto-MOR in GABAergic neurons of the ventral pallidum hedonic cold spot led to real-time place aversion. This tool has generalizable application for spatiotemporal control of opioid signaling and, furthermore, can be used broadly for mimicking endogenous neuronal inhibition pathways. Copyright © 2015 Elsevier Inc. All rights reserved.

Spatially resolved RNA-sequencing of the embryonic heart identifies a role for Wnt/β-catenin signaling in autonomic control of heart rate

PubMed Central

Burkhard, Silja Barbara

2018-01-01

Development of specialized cells and structures in the heart is regulated by spatially -restricted molecular pathways. Disruptions in these pathways can cause severe congenital cardiac malformations or functional defects. To better understand these pathways and how they regulate cardiac development we used tomo-seq, combining high-throughput RNA-sequencing with tissue-sectioning, to establish a genome-wide expression dataset with high spatial resolution for the developing zebrafish heart. Analysis of the dataset revealed over 1100 genes differentially expressed in sub-compartments. Pacemaker cells in the sinoatrial region induce heart contractions, but little is known about the mechanisms underlying their development. Using our transcriptome map, we identified spatially restricted Wnt/β-catenin signaling activity in pacemaker cells, which was controlled by Islet-1 activity. Moreover, Wnt/β-catenin signaling controls heart rate by regulating pacemaker cellular response to parasympathetic stimuli. Thus, this high-resolution transcriptome map incorporating all cell types in the embryonic heart can expose spatially restricted molecular pathways critical for specific cardiac functions. PMID:29400650

Scleral gene expression during recovery from myopia compared with expression during myopia development in tree shrew.

PubMed

Guo, Lin; Frost, Michael R; Siegwart, John T; Norton, Thomas T

2014-01-01

During postnatal refractive development, the sclera receives retinally generated signals that regulate its biochemical properties. Hyperopic refractive error causes the retina to produce "GO" signals that, through the direct emmetropization pathway, cause scleral remodeling that increases the axial elongation rate of the eye, reducing the hyperopia. Myopia causes the retina to generate "STOP" signals that produce scleral remodeling, slowing the axial elongation rate and reducing the myopia. Our aim was to compare the pattern of gene expression produced in the sclera by the STOP signals with the GO gene expression signature we described previously. The GO gene expression signature was produced by monocular -5 diopter (D) lens wear for 2 days (ML-2) or 4 days (ML-4); an additional "STAY" condition was examined after eyes had fully compensated for a -5 D lens after 11 days of lens wear (ML-11). After 11 days of -5 D lens wear had produced full refractive compensation, gene expression in the STOP condition was examined during recovery (without the lens) for 2 days (REC-2) or 4 days (REC-4). The untreated contralateral eyes served as a control in all groups. Two age-matched normal groups provided a comparison with the treated groups. Quantitative real-time PCR was used to measure mRNA levels for 55 candidate genes. The STAY group compensated fully for the lens (treated eye versus control eye, -5.1±0.2 D). Wearing the lens, the hyperopic signal for elongation had dissipated (-0.3±0.3 D). In the STOP groups, the refraction in the recovering eyes became less myopic relative to the control eyes (REC-2, +1.3±0.3 D; REC-4, +2.6±0.4 D). In the STAY group, three genes showed significant downregulation. However, many genes that were significantly altered in GO showed smaller, nonsignificant, expression differences in the same direction in STAY, suggesting the gene expression signature in STAY is a greatly weakened form of the GO signature. In the STOP groups, a different gene expression pattern was observed, characterized by mostly upregulation with larger fold differences after 4 days than after 2 days of recovery. Eleven of the 55 genes examined showed significant bidirectional GO/STOP regulation in the ML-2 and REC-2 groups, and 13 genes showed bidirectional regulation in the ML-4 and REC-4 groups. Eight of these genes (NPR3, CAPNS1, NGEF, TGFB1, CTGF, NOV, TIMP1, and HS6ST1) were bidirectionally regulated at both time points in the GO and STOP conditions. An additional 15 genes showed significant regulation in either GO or STOP conditions but not in both. Many genes are involved in scleral remodeling and the control of axial length. The STOP (recovery) gene expression signature in the sclera involves some of the same genes, bidirectionally regulated, as the GO signature. However, other genes, regulated in GO, are not differentially regulated in STOP, and others show differential regulation only in STOP.

Genome-Wide Identification of Destruxin A-Responsive Immunity-Related MicroRNAs in Diamondback Moth, Plutella xylostella.

PubMed

Shakeel, Muhammad; Xu, Xiaoxia; Xu, Jin; Li, Shuzhong; Yu, Jialin; Zhou, Xianqiang; Xu, Xiaojing; Hu, Qiongbo; Yu, Xiaoqiang; Jin, Fengliang

2018-01-01

Plutella xylostella , a global key pest, is one of the major lepidopteran pests of cruciferous vegetables owing to its strong ability of resistance development to a wide range of insecticides. Destruxin A, a mycotoxin of the entomopathogenic fungus, Metarhizium anisopliae , has broad-spectrum insecticidal effects and has been used as an alternative control strategy to reduce harmful effects of insecticides. However, microRNA (miRNA)-regulated reactions against destruxin A have not been elucidated yet. Therefore, here, to identify immunity-related miRNAs, we constructed four small RNA libraries from destruxin A-injected larvae of P. xylostella at three different time courses (2, 4, and 6 h) with a control, and sequenced by Illumina. Our results showed that totally 187 known and 44 novel miRNAs were identified in four libraries by bioinformatic analysis. Interestingly, among differentially expressed known miRNAs, some conserved miRNAs, such as miR-263, miR-279, miR-306, miR-2a, and miR-308, predicted to be involved in regulating immunity-related genes, were also identified. Worthy to mention, miR-306 and miR-279 were also listed as common abundantly expressed miRNA in all treatments. The Kyoto Encyclopedia of Genes and Genomes pathway analysis also indicated that differentially expressed miRNAs were involved in several immunity-related signaling pathways, including toll signaling pathway, IMD signaling pathway, JAK-STAT signaling pathway, and cell adhesion molecules signaling pathway. To the best of our knowledge, this is the first comprehensive report of destruxin A-responsive immunity-related miRNAs in P. xylostella . Our findings will improve in understanding the role of destruxin A-responsive miRNAs in the host immune system and would be useful to develop biological control strategies for controlling P. xylostella .

Genome-Wide Identification of Destruxin A-Responsive Immunity-Related MicroRNAs in Diamondback Moth, Plutella xylostella

PubMed Central

Shakeel, Muhammad; Xu, Xiaoxia; Xu, Jin; Li, Shuzhong; Yu, Jialin; Zhou, Xianqiang; Xu, Xiaojing; Hu, Qiongbo; Yu, Xiaoqiang; Jin, Fengliang

2018-01-01

Plutella xylostella, a global key pest, is one of the major lepidopteran pests of cruciferous vegetables owing to its strong ability of resistance development to a wide range of insecticides. Destruxin A, a mycotoxin of the entomopathogenic fungus, Metarhizium anisopliae, has broad-spectrum insecticidal effects and has been used as an alternative control strategy to reduce harmful effects of insecticides. However, microRNA (miRNA)-regulated reactions against destruxin A have not been elucidated yet. Therefore, here, to identify immunity-related miRNAs, we constructed four small RNA libraries from destruxin A-injected larvae of P. xylostella at three different time courses (2, 4, and 6 h) with a control, and sequenced by Illumina. Our results showed that totally 187 known and 44 novel miRNAs were identified in four libraries by bioinformatic analysis. Interestingly, among differentially expressed known miRNAs, some conserved miRNAs, such as miR-263, miR-279, miR-306, miR-2a, and miR-308, predicted to be involved in regulating immunity-related genes, were also identified. Worthy to mention, miR-306 and miR-279 were also listed as common abundantly expressed miRNA in all treatments. The Kyoto Encyclopedia of Genes and Genomes pathway analysis also indicated that differentially expressed miRNAs were involved in several immunity-related signaling pathways, including toll signaling pathway, IMD signaling pathway, JAK–STAT signaling pathway, and cell adhesion molecules signaling pathway. To the best of our knowledge, this is the first comprehensive report of destruxin A-responsive immunity-related miRNAs in P. xylostella. Our findings will improve in understanding the role of destruxin A-responsive miRNAs in the host immune system and would be useful to develop biological control strategies for controlling P. xylostella. PMID:29472927

Characterization of a novel rice gene OsATX and modulation of its expression by components of the stress signalling pathways.

PubMed

Agrawal, Ganesh K; Rakwal, Randeep; Jwa, N-S; Agrawal, Vishwanath P

2002-09-01

In our search to identify gene(s) involved in the rice self-defense responses, we cloned a novel rice (Oryza sativa L. cv. Nipponbare) gene, OsATX, a single copy gene, from the JA treated rice seedling leaves cDNA library. This gene encodes a 69 amino acid polypeptide with a predicted molecular mass of 7649.7 and a pI of 5.6. OsATX was responsive to cutting (wounding by cutting the excised leaf), over its weak constitutive expression in the healthy leaves. The critical signalling molecules, jasmonic acid (JA), salicylic acid (SA), abscisic acid (ABA), and hydrogen peroxide, together with protein phosphatase inhibitors, effectively up-regulated the OsATX expression with time, over the excised leaf cut control, whereas ethylene had no affect. Furthermore, copper, a heavy metal, also up-regulated OsATX expression. Moreover, induced expression of OsATX mRNA was influenced by light signal(s), and showed a requirement for de novo synthesized protein factors. Additionally, co-application of either JA or ABA with SA drastically suppressed the induced OsATX mRNA level. Finally, the blast pathogen, Magnaporthe grisea, triggered OsATX mRNA accumulation. These results strongly suggest a function/role(s) for OsATX in defense/stress responses in rice.

Examining the Genetic Background of Porcine Muscle Growth and Development Based on Transcriptome and miRNAome Data.

PubMed

Ropka-Molik, Katarzyna; Pawlina-Tyszko, Klaudia; Żukowski, Kacper; Piórkowska, Katarzyna; Żak, Grzegorz; Gurgul, Artur; Derebecka, Natalia; Wesoły, Joanna

2018-04-16

Recently, selection in pigs has been focused on improving the lean meat content in carcasses; this focus has been most evident in breeds constituting a paternal component in breeding. Such sire-breeds are used to improve the meat quantity of cross-breed pig lines. However, even in one breed, a significant variation in the meatiness level can be observed. In the present study, the comprehensive analysis of genes and microRNA expression profiles in porcine muscle tissue was applied to identify the genetic background of meat content. The comparison was performed between whole gene expression and miRNA profiles of muscle tissue collected from two sire-line pig breeds (Pietrain, Hampshire). The RNA-seq approach allowed the identification of 627 and 416 differentially expressed genes (DEGs) between pig groups differing in terms of loin weight between Pietrain and Hampshire breeds, respectively. The comparison of miRNA profiles showed differential expression of 57 microRNAs for Hampshire and 34 miRNAs for Pietrain pigs. Next, 43 genes and 18 miRNAs were selected as differentially expressed in both breeds and potentially related to muscle development. According to Gene Ontology analysis, identified DEGs and microRNAs were involved in the regulation of the cell cycle, fatty acid biosynthesis and regulation of the actin cytoskeleton. The most deregulated pathways dependent on muscle mass were the Hippo signalling pathway connected with the TGF-β signalling pathway and controlling organ size via the regulation of ubiquitin-mediated proteolysis, cell proliferation and apoptosis. The identified target genes were also involved in pathways such as the FoxO signalling pathway, signalling pathways regulating pluripotency of stem cells and the PI3K-Akt signalling pathway. The obtained results indicate molecular mechanisms controlling porcine muscle growth and development. Identified genes ( SOX2 , SIRT1 , KLF4 , PAX6 and genes belonging to the transforming growth factor beta superfamily) could be considered candidate genes for determining muscle mass in pigs.

c-Ski overexpression promotes tumor growth and angiogenesis through inhibition of transforming growth factor-beta signaling in diffuse-type gastric carcinoma.

PubMed

Kiyono, Kunihiko; Suzuki, Hiroshi I; Morishita, Yasuyuki; Komuro, Akiyoshi; Iwata, Caname; Yashiro, Masakazu; Hirakawa, Kosei; Kano, Mitsunobu R; Miyazono, Kohei

2009-10-01

c-Ski, originally identified as a proto-oncogene product, is an important negative regulator of transforming growth factor (TGF)-beta family signaling through interaction with Smad2, Smad3, and Smad4. High expression of c-Ski has been found in some cancers, including gastric cancer. We previously showed that disruption of TGF-beta signaling by dominant-negative TGF-beta type II receptor in a diffuse-type gastric carcinoma model accelerated tumor growth through induction of tumor angiogenesis by decreased expression of the anti-angiogenic factor thrombospondin (TSP)-1. Here, we examined the function of c-Ski in human diffuse-type gastric carcinoma OCUM-2MLN cells. Overexpression of c-Ski inhibited TGF-beta signaling in OCUM-2MLN cells. Interestingly, c-Ski overexpression resulted in extensive acceleration of the growth of subcutaneous xenografts in BALB/c nu/nu female mice (6 weeks of age). Similar to tumors expressing dominant-negative TGF-beta type II receptor, histochemical studies revealed less fibrosis and increased angiogenesis in xenografted tumors expressing c-Ski compared to control tumors. Induction of TSP-1 mRNA by TGF-beta was attenuated by c-Ski in vitro, and expression of TSP-1 mRNA was decreased in tumors expressing c-Ski in vivo. These findings suggest that c-Ski overexpression promotes the growth of diffuse-type gastric carcinoma through induction of angiogenesis.

Deficiency of PTP1B in leptin receptor-expressing neurons leads to decreased body weight and adiposity in mice.

PubMed

Tsou, Ryan C; Zimmer, Derek J; De Jonghe, Bart C; Bence, Kendra K

2012-09-01

Protein tyrosine phosphatase 1B (PTP1B) is a ubiquitously expressed tyrosine phosphatase implicated in the negative regulation of leptin and insulin receptor signaling. PTP1B(-/-) mice possess a lean metabolic phenotype attributed at least partially to improved hypothalamic leptin sensitivity. Interestingly, mice lacking both leptin and PTP1B (ob/ob:PTP1B(-/-)) have reduced body weight compared with mice lacking leptin only, suggesting that PTP1B may have important leptin-independent metabolic effects. We generated mice with PTP1B deficiency specifically in leptin receptor (LepRb)-expressing neurons (LepRb-PTP1B(-/-)) and compared them with LepRb-Cre-only wild-type (WT) controls and global PTP1B(-/-) mice. Consistent with PTP1B's role as a negative regulator of leptin signaling, our results show that LepRb-PTP1B(-/-) mice are leptin hypersensitive and have significantly reduced body weight when maintained on chow or high-fat diet (HFD) compared with WT controls. LepRb-PTP1B(-/-) mice have a significant decrease in adiposity on HFD compared with controls. Notably, the extent of attenuated body weight gain on HFD, as well as the extent of leptin hypersensitivity, is similar between LepRb-PTP1B(-/-) mice and global PTP1B(-/-) mice. Overall, these results demonstrate that PTP1B deficiency in LepRb-expressing neurons results in reduced body weight and adiposity compared with WT controls and likely underlies the improved metabolic phenotype of global and brain-specific PTP1B-deficient models. Subtle phenotypic differences between LepRb-PTP1B(-/-) and global PTP1B(-/-) mice, however, suggest that PTP1B independent of leptin signaling may also contribute to energy balance in mice.

Endothelial follistatin-like-1 regulates the postnatal development of the pulmonary vasculature by modulating BMP/Smad signaling

PubMed Central

Tania, Navessa P.; Maarsingh, Harm; T. Bos, I. Sophie; Mattiotti, Andrea; Prakash, Stuti; Timens, Wim; Gunst, Quinn D.; Jimenez-Borreguero, Luis J.; Schmidt, Martina; van den Hoff, Maurice J.B.; Gosens, Reinoud

2017-01-01

Bone morphogenetic protein (BMP) signaling regulates vascular smooth muscle maturation, endothelial cell proliferation, and tube formation. The endogenous BMP antagonist Follistatin-like 1 (Fstl1) is highly expressed in pulmonary vascular endothelium of the developing mouse lung, suggesting a role in pulmonary vascular formation and vascular homeostasis. The aim of this study was to investigate the role of Fstl1 in the pulmonary vascular endothelium. To this aim, Fstl1 was conditionally deleted from endothelial and endothelial-derived cells using Tie2-cre driven Fstl1-KO mice (Fstl1-eKO mice). Endothelial-specific Fstl1 deletion was postnatally lethal, as ∼70% of Fstl1-eKO mice died at three weeks after birth. Deletion of Fstl1 from endothelium resulted in a reduction of right ventricular output at three weeks after birth compared with controls. This was associated with pulmonary vascular remodeling, as the percentage of actin-positive small pulmonary vessels was increased at three weeks in Fstl1-eKO mice compared with controls. Endothelial deletion of Fstl1 resulted in activation of Smad1/5/8 signaling and increased BMP/Smad-regulated gene expression of Jagged1, Endoglin, and Gata2 at one week after birth compared with controls. In addition, potent vasoconstrictor Endothelin-1, the expression of which is driven by Gata2, was increased in expression, both on the mRNA and protein levels, at one week after birth compared with controls. At three weeks, Jagged1 was reduced in the Fstl1-eKO mice whereas Endoglin and Endothelin-1 were unchanged. In conclusion, loss of endothelial Fstl1 in the lung is associated with elevated BMP-regulated genes, impaired small pulmonary vascular remodeling, and decreased right ventricular output. PMID:28680581

Endothelial follistatin-like-1 regulates the postnatal development of the pulmonary vasculature by modulating BMP/Smad signaling.

PubMed

Tania, Navessa P; Maarsingh, Harm; T Bos, I Sophie; Mattiotti, Andrea; Prakash, Stuti; Timens, Wim; Gunst, Quinn D; Jimenez-Borreguero, Luis J; Schmidt, Martina; van den Hoff, Maurice J B; Gosens, Reinoud

2017-03-01

Bone morphogenetic protein (BMP) signaling regulates vascular smooth muscle maturation, endothelial cell proliferation, and tube formation. The endogenous BMP antagonist Follistatin-like 1 (Fstl1) is highly expressed in pulmonary vascular endothelium of the developing mouse lung, suggesting a role in pulmonary vascular formation and vascular homeostasis. The aim of this study was to investigate the role of Fstl1 in the pulmonary vascular endothelium. To this aim, Fstl1 was conditionally deleted from endothelial and endothelial-derived cells using Tie2-cre driven Fstl1 -KO mice ( Fstl1 -eKO mice). Endothelial-specific Fstl1 deletion was postnatally lethal, as ∼70% of Fstl1 -eKO mice died at three weeks after birth. Deletion of Fstl1 from endothelium resulted in a reduction of right ventricular output at three weeks after birth compared with controls. This was associated with pulmonary vascular remodeling, as the percentage of actin-positive small pulmonary vessels was increased at three weeks in Fstl1 -eKO mice compared with controls. Endothelial deletion of Fstl1 resulted in activation of Smad1/5/8 signaling and increased BMP/Smad-regulated gene expression of Jagged1, Endoglin, and Gata2 at one week after birth compared with controls. In addition, potent vasoconstrictor Endothelin-1, the expression of which is driven by Gata2, was increased in expression, both on the mRNA and protein levels, at one week after birth compared with controls. At three weeks, Jagged1 was reduced in the Fstl1 -eKO mice whereas Endoglin and Endothelin-1 were unchanged. In conclusion, loss of endothelial Fstl1 in the lung is associated with elevated BMP-regulated genes, impaired small pulmonary vascular remodeling, and decreased right ventricular output.

[MAPK signaling pathways involved in aluminum-induced apoptosis and necroptosis in SH-SY5Y cells].

PubMed

Jia, Xiaofang; Zhang, Qinli; Niu, Qiao

2014-11-01

To explore the role of MAPK signaling pathway in apoptosis and necroptosis induced by aluminum in SH-SY5Y cells. To imitate neural cell death induced by aluminium, AlCl3 x 6H2O (4 mmol/L) was used to treat SH-SY5Y cells. Necrostatin-1 (Nec-1,60 μmol/L), the specific inhibitor for necroptosis, and zVAD-fmk (20 μmol/L), the specific inhibitor for apoptosis, were added into cultures for inhibiting the occurrence of necroptosis and apoptosis. CCK-8 was performed to measure cell viability, flow cytometry was used to test the difference of apoptosis rate and necrosis rate between groups, and western-blot was used to detect the change of MAPK protein. Compared with blank control group, solvent control group, Nec-1 control group and zVAD-fmk control group, cell viabiligy of Al(3+) exposed group, Al(3+) plus Nec-1 group and Al(3+) plus zVAD-fmk group decreaced (P < 0.05). Compared with Al(3+) exposed group, cell viability of Al(3+) plus Nec-1 group and Al(3+) plus zVAD-fmk group increased (P < 0.05). Necrotic rate and apoptotic rate in Al(3+) exposed group, Al(3+) plus Nec-1 group and Al(3+) plus zVAD-fmk group obviously increased compared with blank control group, solvent control group, Nec-1 control group and zVAD-fmk control group (P < 0.05). Compared with Al(3+) exposed group, necrotic and apaptotic rate of Al(3+) plus zVAD-fmk group and Al(3+) plus Nec-1 group were statistically significant decreased (P < 0.05). Compared with blank control group, solvent control group, Nec-1 control group and zVAD-fmk control group, expression of p-p38 in Al(3+) exposed group, Al(3+) plus Nec-1 group and Al(3+) plus zVAD-fmk group increased obviously (P < 0.05), and expression of p-ERK decreased significantly (P < 0.05). Compared with Al(3+) exposed group, expression of p-p38 decreased (P < 0.05), but p-ERK increased in Al(3+) plus Nec-1 group (P < 0.05). The ERK and p38 MAPK signaling pathways are involved in aluminum-induced necroptosis in SH-SY5Y cells, but only ERK signaling pathway is involved in aluminum-induced apoptosis, and JNK signaling pathway is not involved in aluminum-induced cell death.

Endothelial Snail Regulates Capillary Branching Morphogenesis via Vascular Endothelial Growth Factor Receptor 3 Expression

PubMed Central

Park, Jeong Ae; Kim, Dong Young; Kim, Young-Myeong; Kwon, Young-Guen

2015-01-01

Vascular branching morphogenesis is activated and maintained by several signaling pathways. Among them, vascular endothelial growth factor receptor 2 (VEGFR2) signaling is largely presented in arteries, and VEGFR3 signaling is in veins and capillaries. Recent reports have documented that Snail, a well-known epithelial-to-mesenchymal transition protein, is expressed in endothelial cells, where it regulates sprouting angiogenesis and embryonic vascular development. Here, we identified Snail as a regulator of VEGFR3 expression during capillary branching morphogenesis. Snail was dramatically upregulated in sprouting vessels in the developing retinal vasculature, including the leading-edged vessels and vertical sprouting vessels for capillary extension toward the deep retina. Results from in vitro functional studies demonstrate that Snail expression colocalized with VEGFR3 and upregulated VEGFR3 mRNA by directly binding to the VEGFR3 promoter via cooperating with early growth response protein-1. Snail knockdown in postnatal mice attenuated the formation of the deep capillary plexus, not only by impairing vertical sprouting vessels but also by downregulating VEGFR3 expression. Collectively, these data suggest that the Snail-VEGFR3 axis controls capillary extension, especially in vessels expressing VEGFR2 at low levels. PMID:26147525

Gene expression analysis of colorectal cancer by bioinformatics strategy.

PubMed

Cui, Meng; Yuan, Junhua; Li, Jun; Sun, Bing; Li, Tao; Li, Yuantao; Wu, Guoliang

2014-10-01

We used bioinformatics technology to analyze gene expression profiles involved in colorectal cancer tissue samples and healthy controls. In this paper, we downloaded the gene expression profile GSE4107 from Gene Expression Omnibus (GEO) database, in which a total of 22 chips were available, including normal colonic mucosa tissue from normal healthy donors (n=10), colorectal cancer tissue samples from colorectal patients (n=33). To further understand the biological functions of the screened DGEs, the KEGG pathway enrichment analysis were conducted. Then we built a transcriptome network to study differentially co-expressed links. A total of 3151 DEGs of CRC were selected. Besides, total 164 DCGs (Differentially Coexpressed Gene, DCG) and 29279 DCLs (Differentially Co-expressed Link, DCL) were obtained. Furthermore, the significantly enriched KEGG pathways were Endocytosis, Calcium signaling pathway, Vascular smooth muscle contraction, Linoleic acid metabolism, Arginine and proline metabolism, Inositol phosphate metabolism and MAPK signaling pathway. Our results show that the generation of CRC involves multiple genes, TFs and pathways. Several signal and immune pathways are linked to CRC and give us more clues in the process of CRC. Hence, our work would pave ways for novel diagnosis of CRC, and provided theoretical guidance into cancer therapy.

Global regulation by the seven-component Pi signaling system.

PubMed

Hsieh, Yi-Ju; Wanner, Barry L

2010-04-01

This review concerns how Escherichia coli detects environmental inorganic orthophosphate (P(i)) to regulate genes of the phosphate (Pho) regulon by the PhoR/PhoB two-component system (TCS). P(i) control by the PhoR/PhoB TCS is a paradigm of a bacterial signal transduction pathway in which occupancy of a cell surface receptor(s) controls gene expression in the cytoplasm. The P(i) signaling pathway requires seven proteins, all of which probably interact in a membrane-associated signaling complex. Our latest studies show that P(i) signaling involves three distinct processes, which appear to correspond to different states of the sensory histidine kinase PhoR: an inhibition state, an activation state, and a deactivation state. We describe a revised model for P(i) signal transduction of the E. coli Pho regulon. Copyright 2010 Elsevier Ltd. All rights reserved.

Gpr124 controls CNS angiogenesis and blood-brain barrier integrity by promoting ligand-specific canonical wnt signaling.

PubMed

Zhou, Yulian; Nathans, Jeremy

2014-10-27

Canonical Wnt signaling in endothelial cells (ECs) is required for vascularization of the central nervous system (CNS) and for formation and maintenance of barrier properties unique to CNS vasculature. Gpr124 is an orphan member of the adhesion G protein-coupled receptor family that is expressed in ECs and is essential for CNS angiogenesis and barrier formation via an unknown mechanism. Using canonical Wnt signaling assays in cell culture and genetic loss- and gain-of-function experiments in mice, we show that Gpr124 functions as a coactivator of Wnt7a- and Wnt7b-stimulated canonical Wnt signaling via a Frizzled receptor and Lrp coreceptor and that Gpr124-stimulated signaling functions in concert with Norrin/Frizzled4 signaling to control CNS vascular development. These experiments identify Gpr124 as a ligand-specific coactivator of canonical Wnt signaling.

GCN5L1 modulates cross-talk between mitochondria and cell signaling to regulate FoxO1 stability and gluconeogenesis.

PubMed

Wang, Lingdi; Scott, Iain; Zhu, Lu; Wu, Kaiyuan; Han, Kim; Chen, Yong; Gucek, Marjan; Sack, Michael N

2017-09-12

The mitochondrial enriched GCN5-like 1 (GCN5L1) protein has been shown to modulate mitochondrial protein acetylation, mitochondrial content and mitochondrial retrograde signaling. Here we show that hepatic GCN5L1 ablation reduces fasting glucose levels and blunts hepatic gluconeogenesis without affecting systemic glucose tolerance. PEPCK and G6Pase transcript levels are downregulated in hepatocytes from GCN5L1 liver specific knockout mice and their upstream regulator, FoxO1 protein levels are decreased via proteasome-dependent degradation and via reactive oxygen species mediated ERK-1/2 phosphorylation. ERK inhibition restores FoxO1, gluconeogenic enzyme expression and glucose production. Reconstitution of mitochondrial-targeted GCN5L1 blunts mitochondrial ROS, ERK activation and increases FoxO1, gluconeogenic enzyme expression and hepatocyte glucose production. We suggest that mitochondrial GCN5L1 modulates post-translational control of FoxO1, regulates gluconeogenesis and controls metabolic pathways via mitochondrial ROS mediated ERK activation. Exploring mechanisms underpinning GCN5L1 mediated ROS signaling may expand our understanding of the role of mitochondria in gluconeogenesis control.Hepatic gluconeogenesis is tightly regulated at transcriptional level and is essential for survival during prolonged fasting. Here Wang et al. show that the mitochondrial enriched GCN5-like 1 protein controls hepatic glucose production by regulating FoxO1 protein levels via proteasome-dependent degradation and, in turn, gluconeogenic gene expression.

The influence of stereolithographic scaffold architecture and composition on osteogenic signal expression with rat bone marrow stromal cells

PubMed Central

Kim, Kyobum; Dean, David; Wallace, Jonathan; Breithaupt, Rob; Mikos, Antonios G.; Fisher, John P.

2011-01-01

Scaffold design parameters, especially physical construction factors such as mechanical stiffness of substrate materials, pore size of 3D porous scaffolds, and channel geometry, are known to influence the osteogenic signal expression and subsequent differentiation of a transplanted cell population. In this study of photocrosslinked poly(propylene fumarate) (PPF) and diethyl fumarate (DEF) scaffolds, the effect of DEF incorporation ratio and pore size on the osteogenic signal expression of rat bone marrow stromal cells (BMSCs) was investigated. Results demonstrated that DEF concentrations and pore sizes that led to increased scaffold mechanical stiffness also upregulated osteogenic signal expression, including bone morphogenic protein-2 (BMP-2), fibroblast growth factors-2 (FGF-2), transforming growth factor-β1 (TGF-β1), vascular endothelial growth factor (VEGF), and Runx2 transcriptional factor. Similar scaffold fabrication parameters supported rapid BMSC osteoblastic differentiation, as demonstrated by increased alkaline phosphatase (ALP) and osteocalcin expression. When scaffolds with random architecture, fabricated by porogen leaching, were compared to those with controlled architecture, fabricated by stereolithography (SLA), results showed that SLA scaffolds with the highly permeable and porous channels also have significantly higher expression of FGF-2, TGF-β1, and VEGF. Subsequent ALP expression and osteopontin secretion were also significantly increased in SLA scaffolds. Based upon these results, we conclude that scaffold properties provided by additive manufacturing techniques such as SLA fabrication, particularly increased mechanical stiffness and high permeability, may stimulate dramatic BMSC responses that promote rapid bone tissue regeneration. PMID:21396709

Pathway-based outlier method reveals heterogeneous genomic structure of autism in blood transcriptome

PubMed Central

2013-01-01

Background Decades of research strongly suggest that the genetic etiology of autism spectrum disorders (ASDs) is heterogeneous. However, most published studies focus on group differences between cases and controls. In contrast, we hypothesized that the heterogeneity of the disorder could be characterized by identifying pathways for which individuals are outliers rather than pathways representative of shared group differences of the ASD diagnosis. Methods Two previously published blood gene expression data sets – the Translational Genetics Research Institute (TGen) dataset (70 cases and 60 unrelated controls) and the Simons Simplex Consortium (Simons) dataset (221 probands and 191 unaffected family members) – were analyzed. All individuals of each dataset were projected to biological pathways, and each sample’s Mahalanobis distance from a pooled centroid was calculated to compare the number of case and control outliers for each pathway. Results Analysis of a set of blood gene expression profiles from 70 ASD and 60 unrelated controls revealed three pathways whose outliers were significantly overrepresented in the ASD cases: neuron development including axonogenesis and neurite development (29% of ASD, 3% of control), nitric oxide signaling (29%, 3%), and skeletal development (27%, 3%). Overall, 50% of cases and 8% of controls were outliers in one of these three pathways, which could not be identified using group comparison or gene-level outlier methods. In an independently collected data set consisting of 221 ASD and 191 unaffected family members, outliers in the neurogenesis pathway were heavily biased towards cases (20.8% of ASD, 12.0% of control). Interestingly, neurogenesis outliers were more common among unaffected family members (Simons) than unrelated controls (TGen), but the statistical significance of this effect was marginal (Chi squared P < 0.09). Conclusions Unlike group difference approaches, our analysis identified the samples within the case and control groups that manifested each expression signal, and showed that outlier groups were distinct for each implicated pathway. Moreover, our results suggest that by seeking heterogeneity, pathway-based outlier analysis can reveal expression signals that are not apparent when considering only shared group differences. PMID:24063311

Diet-induced obesity mediated by the JNK/DIO2 signal transduction pathway

PubMed Central

Vernia, Santiago; Cavanagh-Kyros, Julie; Barrett, Tamera; Jung, Dae Young; Kim, Jason K.; Davis, Roger J.

2013-01-01

The cJun N-terminal kinase (JNK) signaling pathway is a key mediator of metabolic stress responses caused by consuming a high-fat diet, including the development of obesity. To test the role of JNK, we examined diet-induced obesity in mice with targeted ablation of Jnk genes in the anterior pituitary gland. These mice exhibited an increase in the pituitary expression of thyroid-stimulating hormone (TSH), an increase in the blood concentration of thyroid hormone (T4), increased energy expenditure, and markedly reduced obesity compared with control mice. The increased amount of pituitary TSH was caused by reduced expression of type 2 iodothyronine deiodinase (Dio2), a gene that is required for T4-mediated negative feedback regulation of TSH expression. These data establish a molecular mechanism that accounts for the regulation of energy expenditure and the development of obesity by the JNK signaling pathway. PMID:24186979

UniVIO: A Multiple Omics Database with Hormonome and Transcriptome Data from Rice

PubMed Central

Sakurai, Tetsuya; Sakakibara, Hitoshi

2013-01-01

Plant hormones play important roles as signaling molecules in the regulation of growth and development by controlling the expression of downstream genes. Since the hormone signaling system represents a complex network involving functional cross-talk through the mutual regulation of signaling and metabolism, a comprehensive and integrative analysis of plant hormone concentrations and gene expression is important for a deeper understanding of hormone actions. We have developed a database named Uniformed Viewer for Integrated Omics (UniVIO: http://univio.psc.riken.jp/), which displays hormone-metabolome (hormonome) and transcriptome data in a single formatted (uniformed) heat map. At the present time, hormonome and transcriptome data obtained from 14 organ parts of rice plants at the reproductive stage and seedling shoots of three gibberellin signaling mutants are included in the database. The hormone concentration and gene expression data can be searched by substance name, probe ID, gene locus ID or gene description. A correlation search function has been implemented to enable users to obtain information of correlated substance accumulation and gene expression. In the correlation search, calculation method, range of correlation coefficient and plant samples can be selected freely. PMID:23314752

Functional redundancy in the control of seedling growth by the karrikin signaling pathway.

PubMed

Stanga, John P; Morffy, Nicholas; Nelson, David C

2016-06-01

SMAX1 and SMXL2 control seedling growth, demonstrating functional redundancy within a gene family that mediates karrikin and strigolactone responses. Strigolactones (SLs) are plant hormones with butenolide moieties that control diverse aspects of plant growth, including shoot branching. Karrikins (KARs) are butenolide molecules found in smoke that enhance seed germination and seedling photomorphogenesis. In Arabidopsis thaliana, SLs and KARs signal through the α/β hydrolases D14 and KAI2, respectively. The F-box protein MAX2 is essential for both signaling pathways. SUPPRESSOR OF MAX2 1 (SMAX1) plays a prominent role in KAR-regulated growth downstream of MAX2, and SMAX1-LIKE genes SMXL6, SMXL7, and SMXL8 mediate SL responses. We previously found that smax1 loss-of-function mutants display constitutive KAR response phenotypes, including reduced seed dormancy and hypersensitive growth responses to light in seedlings. However, smax1 seedlings remain slightly responsive to KARs, suggesting that there is functional redundancy in karrikin signaling. SMXL2 is a strong candidate for this redundancy because it is the closest paralog of SMAX1, and because its expression is regulated by KAR signaling. Here, we present evidence that SMXL2 controls hypocotyl growth and expression of the KAR/SL transcriptional markers KUF1, IAA1, and DLK2 redundantly with SMAX1. Hypocotyl growth in the smax1 smxl2 double mutant is insensitive to KAR and SL, and etiolated smax1 smxl2 seedlings have reduced hypocotyl elongation. However, smxl2 has little or no effect on seed germination, leaf shape, or petiole orientation, which appear to be predominantly controlled by SMAX1. Neither SMAX1 nor SMXL2 affect axillary branching or inflorescence height, traits that are under SL control. These data support the model that karrikin and strigolactone responses are mediated by distinct subclades of the SMXL family, and further the case for parallel butenolide signaling pathways that evolved through ancient KAI2 and SMXL duplications.

Phytohormonal Networks Promote Differentiation of Fiber Initials on Pre-Anthesis Cotton Ovules Grown In Vitro and In Planta

PubMed Central

Kim, Hee Jin; Hinchliffe, Doug J.; Triplett, Barbara A.; Chen, Z. Jeffrey; Stelly, David M.; Yeater, Kathleen M.; Moon, Hong S.; Gilbert, Matthew K.; Thyssen, Gregory N.; Turley, Rickie B.; Fang, David D.

2015-01-01

The number of cotton (Gossypium sp.) ovule epidermal cells differentiating into fiber initials is an important factor affecting cotton yield and fiber quality. Despite extensive efforts in determining the molecular mechanisms regulating fiber initial differentiation, only a few genes responsible for fiber initial differentiation have been discovered. To identify putative genes directly involved in the fiber initiation process, we used a cotton ovule culture technique that controls the timing of fiber initial differentiation by exogenous phytohormone application in combination with comparative expression analyses between wild type and three fiberless mutants. The addition of exogenous auxin and gibberellins to pre-anthesis wild type ovules that did not have visible fiber initials increased the expression of genes affecting auxin, ethylene, ABA and jasmonic acid signaling pathways within 1 h after treatment. Most transcripts expressed differentially by the phytohormone treatment in vitro were also differentially expressed in the ovules of wild type and fiberless mutants that were grown in planta. In addition to MYB25-like, a gene that was previously shown to be associated with the differentiation of fiber initials, several other differentially expressed genes, including auxin/indole-3-acetic acid (AUX/IAA) involved in auxin signaling, ACC oxidase involved in ethylene biosynthesis, and abscisic acid (ABA) 8'-hydroxylase an enzyme that controls the rate of ABA catabolism, were co-regulated in the pre-anthesis ovules of both wild type and fiberless mutants. These results support the hypothesis that phytohormonal signaling networks regulate the temporal expression of genes responsible for differentiation of cotton fiber initials in vitro and in planta. PMID:25927364

Pancreatic polypeptide controls energy homeostasis via Npy6r signaling in the suprachiasmatic nucleus in mice.

PubMed

Yulyaningsih, Ernie; Loh, Kim; Lin, Shu; Lau, Jackie; Zhang, Lei; Shi, Yanchuan; Berning, Britt A; Enriquez, Ronaldo; Driessler, Frank; Macia, Laurence; Khor, Ee Cheng; Qi, Yue; Baldock, Paul; Sainsbury, Amanda; Herzog, Herbert

2014-01-07

Y-receptors control energy homeostasis, but the role of Npy6 receptors (Npy6r) is largely unknown. Young Npy6r-deficient (Npy6r(-/-)) mice have reduced body weight, lean mass, and adiposity, while older and high-fat-fed Npy6r(-/-) mice have low lean mass with increased adiposity. Npy6r(-/-) mice showed reduced hypothalamic growth hormone releasing hormone (Ghrh) expression and serum insulin-like growth factor-1 (IGF-1) levels relative to WT. This is likely due to impaired vasoactive intestinal peptide (VIP) signaling in the suprachiasmatic nucleus (SCN), where we found Npy6r coexpressed in VIP neurons. Peripheral administration of pancreatic polypeptide (PP) increased Fos expression in the SCN, increased energy expenditure, and reduced food intake in WT, but not Npy6r(-/-), mice. Moreover, intraperitoneal (i.p.) PP injection increased hypothalamic Ghrh mRNA expression and serum IGF-1 levels in WT, but not Npy6r(-/-), mice, an effect blocked by intracerebroventricular (i.c.v.) Vasoactive Intestinal Peptide (VPAC) receptors antagonism. Thus, PP-initiated signaling through Npy6r in VIP neurons regulates the growth hormone axis and body composition. Copyright © 2014 Elsevier Inc. All rights reserved.

Reassessing ecdysteroidogenic cells from the cell membrane receptors' perspective.

PubMed

Alexandratos, Alexandros; Moulos, Panagiotis; Nellas, Ioannis; Mavridis, Konstantinos; Dedos, Skarlatos G

2016-02-05

Ecdysteroids secreted by the prothoracic gland (PG) cells of insects control the developmental timing of their immature life stages. These cells have been historically considered as carrying out a single function in insects, namely the biochemical conversion of cholesterol to ecdysteroids and their secretion. A growing body of evidence shows that PG cells receive multiple cues during insect development so we tested the hypothesis that they carry out more than just one function in insects. We characterised the molecular nature and developmental profiles of cell membrane receptors in PG cells of Bombyx mori during the final larval stage and determined what receptors decode nutritional, developmental and physiological signals. Through iterative approaches we identified a complex repertoire of cell membrane receptors that are expressed in intricate patterns and activate previously unidentified signal transduction cascades in PG cells. The expression patterns of some of these receptors explain precisely the mechanisms that are known to control ecdysteroidogenesis. However, the presence of receptors for the notch, hedgehog and wingless signalling pathways and the expression of innate immunity-related receptors such as phagocytosis receptors, receptors for microbial ligands and Toll-like receptors call for a re-evaluation of the role these cells play in insects.

Downregulation of insulin-like growth factor binding protein 3 and 5 in nitrofen-induced pulmonary hypoplasia.

PubMed

Ruttenstock, Elke; Doi, Takashi; Dingemann, Jens; Puri, Prem

2010-01-01

The high mortality in congenital diaphragmatic hernia (CDH) is mainly attributed to pulmonary hypoplasia. Recent studies suggest that retinoid signaling pathway (RSP) is inhibited in the nitrofen-induced hypoplastic lung. The insulin-like growth factor (IGF) system plays a crucial role in fetal lung development by interaction of IGFBP-3 and IGFBP-5 with RSP. We hypothesized that pulmonary IGFBP-3 and IGFBP-5 gene expression levels are downregulated in the nitrofen-induced pulmonary hypoplasia. Pregnant rats were exposed to either olive oil or 100 mg nitrofen on day 9.5 (D9.5) of gestation. Fetal lungs were harvested on D18 and D21 and divided into control and nitrofen groups. IGFBP-3 and IGFBP-5 pulmonary gene and protein expression were determined using real-time RT-PCR and immunohistochemistry. Relative levels of IGFBP-3 mRNA were significantly decreased in the nitrofen group (8.00 +/- 14.44) in D21 compared to controls (14.81 +/- 16.11; p < 0.05). Expression levels of IGFBP-5 mRNA were also significantly decreased in nitrofen group (10.66 +/- 4.83) on D18 compared to controls (17.92 +/- 4.77). Immunohistochemistry showed decreased IGFBP-3 expression on D21 and decreased IGFBP-5 immunoreactivity on D18 in hypoplastic lungs compared to controls. Downregulation of IGFBP-3 and IGFBP-5 gene expression may cause pulmonary hypoplasia in the nitrofen-induced CDH model by interfering with retinoid signaling pathway.

CXCL14 is a candidate biomarker for Hedgehog signalling in idiopathic pulmonary fibrosis.

PubMed

Jia, Guiquan; Chandriani, Sanjay; Abbas, Alexander R; DePianto, Daryle J; N'Diaye, Elsa N; Yaylaoglu, Murat B; Moore, Heather M; Peng, Ivan; DeVoss, Jason; Collard, Harold R; Wolters, Paul J; Egen, Jackson G; Arron, Joseph R

2017-09-01

Idiopathic pulmonary fibrosis (IPF) is associated with aberrant expression of developmental pathways, including Hedgehog (Hh). As Hh signalling contributes to multiple pro-fibrotic processes, Hh inhibition may represent a therapeutic option for IPF. However, no non-invasive biomarkers are available to monitor lung Hh activity. We assessed gene and protein expression in IPF and control lung biopsies, mouse lung, fibroblasts stimulated in vitro with sonic hedgehog (SHh), and plasma in IPF patients versus controls, and cancer patients before and after treatment with vismodegib, a Hh inhibitor. Lung tissue from IPF patients exhibited significantly greater expression of Hh-related genes versus controls. The gene most significantly upregulated in both IPF lung biopsies and fibroblasts stimulated in vitro with SHh was CXCL14 , which encodes a soluble secreted chemokine whose expression is inhibited in vitro by the addition of vismodegib. CXCL14 expression was induced by SHh overexpression in mouse lung. Circulating CXCL14 protein levels were significantly higher in plasma from IPF patients than controls. In cancer patients, circulating CXCL14 levels were significantly reduced upon vismodegib treatment. CXCL14 is a systemic biomarker that could be used to identify IPF patients with increased Hh pathway activity and monitor the pharmacodynamic effects of Hh antagonist therapy in IPF. Post-results, NCT00968981. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Mind-controlled transgene expression by a wireless-powered optogenetic designer cell implant.

PubMed

Folcher, Marc; Oesterle, Sabine; Zwicky, Katharina; Thekkottil, Thushara; Heymoz, Julie; Hohmann, Muriel; Christen, Matthias; Daoud El-Baba, Marie; Buchmann, Peter; Fussenegger, Martin

2014-11-11

Synthetic devices for traceless remote control of gene expression may provide new treatment opportunities in future gene- and cell-based therapies. Here we report the design of a synthetic mind-controlled gene switch that enables human brain activities and mental states to wirelessly programme the transgene expression in human cells. An electroencephalography (EEG)-based brain-computer interface (BCI) processing mental state-specific brain waves programs an inductively linked wireless-powered optogenetic implant containing designer cells engineered for near-infrared (NIR) light-adjustable expression of the human glycoprotein SEAP (secreted alkaline phosphatase). The synthetic optogenetic signalling pathway interfacing the BCI with target gene expression consists of an engineered NIR light-activated bacterial diguanylate cyclase (DGCL) producing the orthogonal second messenger cyclic diguanosine monophosphate (c-di-GMP), which triggers the stimulator of interferon genes (STING)-dependent induction of synthetic interferon-β promoters. Humans generating different mental states (biofeedback control, concentration, meditation) can differentially control SEAP production of the designer cells in culture and of subcutaneous wireless-powered optogenetic implants in mice.

Dihydrotestosterone deteriorates cardiac insulin signaling and glucose transport in the rat model of polycystic ovary syndrome.

PubMed

Tepavčević, Snežana; Vojnović Milutinović, Danijela; Macut, Djuro; Žakula, Zorica; Nikolić, Marina; Božić-Antić, Ivana; Romić, Snježana; Bjekić-Macut, Jelica; Matić, Gordana; Korićanac, Goran

2014-05-01

It is supposed that women with polycystic ovary syndrome (PCOS) are prone to develop cardiovascular disease as a consequence of multiple risk factors that are mostly related to the state of insulin resistance and consequent hyperinsulinemia. In the present study, we evaluated insulin signaling and glucose transporters (GLUT) in cardiac cells of dihydrotestosterone (DHT) treated female rats as an animal model of PCOS. Expression of proteins involved in cardiac insulin signaling pathways and glucose transporters, as well as their phosphorylation or intracellular localization were studied by Western blot analysis in DHT-treated and control rats. Treatment with DHT resulted in increased body mass, absolute mass of the heart, elevated plasma insulin concentration, dyslipidemia and insulin resistance. At the molecular level, DHT treatment did not change protein expression of cardiac insulin receptor and insulin receptor substrate 1, while phosphorylation of the substrate at serine 307 was increased. Unexpectedly, although expression of downstream Akt kinase and its phosphorylation at threonine 308 were not altered, phosphorylation of Akt at serine 473 was increased in the heart of DHT-treated rats. In contrast, expression and phosphorylation of extracellular signal regulated kinases 1/2 were decreased. Plasma membrane contents of GLUT1 and GLUT4 were decreased, as well as the expression of GLUT4 in cardiac cells at the end of androgen treatment. The obtained results provide evidence for alterations in expression and especially in functional characteristics of insulin signaling molecules and glucose transporters in the heart of DHT-treated rats with PCOS, indicating impaired cardiac insulin action. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hypoxia enhances periodontal ligament stem cell proliferation via the MAPK signaling pathway.

PubMed

He, Y; Jian, C X; Zhang, H Y; Zhou, Y; Wu, X; Zhang, G; Tan, Y H

2016-11-21

There is high incidence of periodontal disease in high-altitude environments; hypoxia may influence the proliferation and clone-forming ability of periodontal ligament stem cells (PDLSCs). The MAPK signaling pathway is closely correlated with cell proliferation, differentiation, and apoptosis. Thus, we isolated and cultured PDLSCs under hypoxic conditions to clarify the impact of hypoxia on PDLSC proliferation and the underlying mechanism. PDLSCs were separated and purified by the limiting dilution method and identified by flow cytometry. PDLSCs were cultured under hypoxic or normoxic conditions to observe their cloning efficiency. PDLSC proliferation at different oxygen concentrations was evaluated by MTT assay. Expression of p38/MAPK and MAPK/ERK signaling pathway members was detected by western blotting. Inhibitors for p38/MAPK or ERK were applied to PDLSCs to observe their impacts on clone formation and proliferation. Isolated PDLSCs exhibited typical stem cell morphological characteristics, strong abilities of globular clone formation and proliferation, and upregulated expression of mesenchymal stem cell markers. Stem cell marker expression was not statistically different between PDLSCs cultured under hypoxia and normoxia (P > 0.05). The clone number in the hypoxia group was significantly higher than that in the control (P < 0.05). PDLSC proliferation under hypoxia was higher than that of the control (P < 0.001). p38 and ERK1/2 phosphorylation in hypoxic PDLSCs was markedly enhanced compared to that in the control (P < 0.05). Either P38/MAPK inhibitor or ERK inhibitor treatment reduced clone formation and proliferation. Therefore, hypoxia enhanced PDLSC clone formation and proliferation by activating the p38/MAPK and ERK/MAPK signaling pathways.

Thyroid hormones and skeletal muscle — new insights and potential implications

PubMed Central

Salvatore, Domenico; Simonides, Warner S.; Dentice, Monica; Zavacki, Ann Marie; Larsen, P. Reed

2014-01-01

Thyroid hormone signalling regulates crucial biological functions, including energy expenditure, thermogenesis, development and growth. The skeletal muscle is a major target of thyroid hormone signalling. The type two (DIO2) and three (DIO3) iodothyronine deiodinases have been identified in skeletal muscle. DIO2 expression is tightly regulated and catalyzes outer ring monodeiodination of the secreted prohormone tetraiodothyronine (T4) to generate the active hormone triiodothyronine (T3). T3 may remain in the myocyte to signal through nuclear receptors or exit the cell to mix with the extracellular pool. By contrast, DIO3 inactivates T3 through removal of an inner ring iodine. Regulation of the expression and activity of deiodinases constitutes a cell-autonomous, pre-receptor mechanism for controlling the intracellular concentration of T3. This local control of T3 activity is crucial during the various phases of myogenesis. Here, we review the roles of T3 in skeletal muscle development and homeostasis, with a focus on the emerging local deiodinase-mediated control of T3 signalling. Moreover, we discuss these novel findings in the context of both muscle homeostasis and pathology, and examine how they can be therapeutically harnessed to improve satellite cell-mediated muscle repair in patients with skeletal muscle disorders, muscle atrophy or injury. PMID:24322650

Differential Expression of IL-17, 22 and 23 in the Progression of Colorectal Cancer in Patients with K-ras Mutation: Ras Signal Inhibition and Crosstalk with GM-CSF and IFN-γ

PubMed Central

Petanidis, Savvas; Anestakis, Doxakis; Argyraki, Maria; Hadzopoulou-Cladaras, Margarita; Salifoglou, Athanasios

2013-01-01

Recent studies have suggested that aberrant K-ras signaling is responsible for triggering immunological responses and inflammation-driven tumorigenesis. Interleukins IL-17, IL-22, and IL-23 have been reported in various types of malignancies, but the exact mechanistic role of these molecules remains to be elucidated. Given the role of K-ras and the involvement of interleukins in colorectal tumorigenesis, research efforts are reported for the first time, showing that differentially expressed interleukin IL-17, IL-22, and IL-23 levels are associated with K-ras in a stage-specific fashion along colorectal cancer progression. Specifically, a) the effect of K-ras signaling was investigated in the overall expression of interleukins in patients with colorectal cancer and healthy controls, and b) an association was established between mutant K-ras and cytokines GM-CSF and IFN-γ. The results indicate that specific interleukins are differentially expressed in K-ras positive patients and the use of K-ras inhibitor Manumycin A decreases both interleukin levels and apoptosis in Caco-2 cells by inhibiting cell viability. Finally, inflammation-driven GM-CSF and IFN-γ levels are modulated through interleukin expression in tumor patients, with interleukin expression in the intestinal lumen and cancerous tissue mediated by aberrant K-ras signaling. Collectively, the findings a) indicate that interleukin expression is influenced by ras signaling and specific interleukins play an oncogenic promoter role in colorectal cancer, highlighting the molecular link between inflammation and tumorigenesis, and b) accentuate the interwoven molecular correlations as leads to new therapeutic approaches in the future. PMID:24040001

Differences in gene expression profiles and signaling pathways in rhabdomyolysis-induced acute kidney injury.

PubMed

Geng, Xiaodong; Wang, Yuanda; Hong, Quan; Yang, Jurong; Zheng, Wei; Zhang, Gang; Cai, Guangyan; Chen, Xiangmei; Wu, Di

2015-01-01

Rhabdomyolysis is a threatening syndrome because it causes the breakdown of skeletal muscle. Muscle destruction leads to the release of myoglobin, intracellular proteins, and electrolytes into the circulation. The aim of this study was to investigate the differences in gene expression profiles and signaling pathways upon rhabdomyolysis-induced acute kidney injury (AKI). In this study, we used glycerol-induced renal injury as a model of rhabdomyolysis-induced AKI. We analyzed data and relevant information from the Gene Expression Omnibus database (No: GSE44925). The gene expression data for three untreated mice were compared to data for five mice with rhabdomyolysis-induced AKI. The expression profiling of the three untreated mice and the five rhabdomyolysis-induced AKI mice was performed using microarray analysis. We examined the levels of Cyp3a13, Rela, Aldh7a1, Jun, CD14. And Cdkn1a using RT-PCR to determine the accuracy of the microarray results. The microarray analysis showed that there were 1050 downregulated and 659 upregulated genes in the rhabdomyolysis-induced AKI mice compared to the control group. The interactions of all differentially expressed genes in the Signal-Net were analyzed. Cyp3a13 and Rela had the most interactions with other genes. The data showed that Rela and Aldh7a1 were the key nodes and had important positions in the Signal-Net. The genes Jun, CD14, and Cdkn1a were also significantly upregulated. The pathway analysis classified the differentially expressed genes into 71 downregulated and 48 upregulated pathways including the PI3K/Akt, MAPK, and NF-κB signaling pathways. The results of this study indicate that the NF-κB, MAPK, PI3K/Akt, and apoptotic pathways are regulated in rhabdomyolysis-induced AKI.

Stress exposure alters brain mRNA expression of the genes involved in insulin signalling, an effect modified by a high fat/high fructose diet and cinnamon supplement

PubMed Central

Qin, Bolin; Arvy, Nathalie; Poulet, Laurent; Batandier, Cécile; Roussel, Anne-Marie; Anderson, Richard A.

2018-01-01

In occidental societies, high fat and high sugar diets often coincide with episodes of stress. The association is likely to modify brain energy control. Brain insulin signalling is rarely studied in stressed individuals consuming high fat diets. Furthermore the effects of cinnamon supplement are not known in these conditions. Therefore, we exposed rats, over a 12-week period, to a control (C) or a high fat/high fructose (HF/HFr) diet that induces peripheral insulin resistance. A cinnamon supplement (C+CN and HF/HFr +CN) was added or not. After diet exposure, one group of rats was exposed to a 30-min restraint followed by a 10-min open-field test, their combination featuring a moderate stressor, the other rats staying unstressed in their home cages. The insulin signalling in hippocampus and frontal cortex was studied through the mRNA expression of the following genes: insulin receptor (Ir), insulin receptor substrate (Irs1), glucose transporters (Glut1 and Glut3), glycogen synthase (Gys1) and their modulators, Akt1 and Pten. In C rats, stress enhanced the expression of Ir, Irs1, Glut1, Gys1 and Akt1 mRNA. In C+CN rats, stress induced an increase in Pten but a decrease in Gys1 mRNA expression. In HF/HFr rats, stress was associated with an increase in Pten mRNA expression. In HF/HFr+CN rats, stress increased Pten mRNA expression but also decreased Gys1 mRNA expression. This suggests that a single moderate stress favours energy refilling mechanisms, an effect blunted by a previous HF/HFr diet and cinnamon supplement. PMID:29813096

Stress exposure alters brain mRNA expression of the genes involved in insulin signalling, an effect modified by a high fat/high fructose diet and cinnamon supplement.

PubMed

Canini, Frédéric; Qin, Bolin; Arvy, Nathalie; Poulet, Laurent; Batandier, Cécile; Roussel, Anne-Marie; Anderson, Richard A

2018-01-01

In occidental societies, high fat and high sugar diets often coincide with episodes of stress. The association is likely to modify brain energy control. Brain insulin signalling is rarely studied in stressed individuals consuming high fat diets. Furthermore the effects of cinnamon supplement are not known in these conditions. Therefore, we exposed rats, over a 12-week period, to a control (C) or a high fat/high fructose (HF/HFr) diet that induces peripheral insulin resistance. A cinnamon supplement (C+CN and HF/HFr +CN) was added or not. After diet exposure, one group of rats was exposed to a 30-min restraint followed by a 10-min open-field test, their combination featuring a moderate stressor, the other rats staying unstressed in their home cages. The insulin signalling in hippocampus and frontal cortex was studied through the mRNA expression of the following genes: insulin receptor (Ir), insulin receptor substrate (Irs1), glucose transporters (Glut1 and Glut3), glycogen synthase (Gys1) and their modulators, Akt1 and Pten. In C rats, stress enhanced the expression of Ir, Irs1, Glut1, Gys1 and Akt1 mRNA. In C+CN rats, stress induced an increase in Pten but a decrease in Gys1 mRNA expression. In HF/HFr rats, stress was associated with an increase in Pten mRNA expression. In HF/HFr+CN rats, stress increased Pten mRNA expression but also decreased Gys1 mRNA expression. This suggests that a single moderate stress favours energy refilling mechanisms, an effect blunted by a previous HF/HFr diet and cinnamon supplement.

Transplacental exposure to inorganic arsenic at a hepatocarcinogenic dose induces fetal gene expression changes in mice indicative of aberrant estrogen signaling and disrupted steroid metabolism

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

Liu Jie; Xie Yaxiong; Cooper, Ryan

Exposure to inorganic arsenic in utero in C3H mice produces hepatocellular carcinoma in male offspring when they reach adulthood. To help define the molecular events associated with the fetal onset of arsenic hepatocarcinogenesis, pregnant C3H mice were given drinking water containing 0 (control) or 85 ppm arsenic from day 8 to 18 of gestation. At the end of the arsenic exposure period, male fetal livers were removed and RNA isolated for microarray analysis using 22K oligo chips. Arsenic exposure in utero produced significant (p < 0.001) alterations in expression of 187 genes, with approximately 25% of aberrantly expressed genes relatedmore » to either estrogen signaling or steroid metabolism. Real-time RT-PCR on selected genes confirmed these changes. Various genes controlled by estrogen, including X-inactive-specific transcript, anterior gradient-2, trefoil factor-1, CRP-ductin, ghrelin, and small proline-rich protein-2A, were dramatically over-expressed. Estrogen-regulated genes including cytokeratin 1-19 and Cyp2a4 were over-expressed, although Cyp3a25 was suppressed. Several genes involved with steroid metabolism also showed remarkable expression changes, including increased expression of 17{beta}-hydroxysteroid dehydrogenase-7 (HSD17{beta}7; involved in estradiol production) and decreased expression of HSD17{beta}5 (involved in testosterone production). The expression of key genes important in methionine metabolism, such as methionine adenosyltransferase-1a, betaine-homocysteine methyltransferase and thioether S-methyltransferase, were suppressed. Thus, exposure of mouse fetus to inorganic arsenic during a critical period in development significantly alters the expression of various genes encoding estrogen signaling and steroid or methionine metabolism. These alterations could disrupt genetic programming at the very early life stage, which could impact tumor formation much later in adulthood.« less

MicroRNA-140 Suppresses Human Chondrocytes Hypertrophy by Targeting SMAD1 and Controlling the Bone Morphogenetic Protein Pathway in Osteoarthritis.

PubMed

Li, Canfeng; Hu, Qinshen; Chen, Zhuo; Shen, Bin; Yang, Jing; Kang, Pengde; Zhou, Zongke; Pei, Fuxing

2018-05-01

This study aimed to investigate the expression levels and relationship of bone morphogenetic proteins (BMPs) signaling molecules and microRNA-140 (miR-140) in human osteoarthritis (OA) chondrocytes. Different stage chondrocytes (normal cartilage, mid-stage OA and advanced-stage OA) were isolated from cartilage samples according to Kellgren and Lawrence criteria. The effect of miR-140 on BMPs signaling was evaluated by transfecting miR-140 mimic or inhibitor into chondrocytes. The expression of responsive genes was measured using real-time polymerase chain reaction and Western blotting analysis. There was a significant reduction in miR-140 and SOX9 expression in OA groups compared to the normal group, and there was a further reduction in the severe OA group compared to the moderate OA group. Compared with the normal group, the expression of ALK1, SMAD1, COL10A1 and MMP3 was higher in the OA groups, whereas the expression of COL2A1 was lower in the OA groups. In the moderate OA group, transfection with miR-140 mimic increased SMAD1, SOX9 and COL2A1 expression, but decreased COL10A1 expression. However, there was an opposite effect after transfecting miR-140 inhibitor with decreased SMAD1, SOX9 and COL2A1 expression, and increased COL10A1 expression. Interestingly, the biological effect of transfecting miR-140 mimic or inhibitor was similar in the severe OA group. SMAD1 and COL2A1 protein production followed the same pattern as their expression profile. miR-140 suppresses chondrocytes hypertrophy by controlling the BMPs signaling pathway, which highlights the importance of miR-140 in the maintenance of chondrocyte homeostasis and opens up novel avenues in OA therapeutic strategies. Copyright © 2018 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

Role of fractalkine/CX3CR1 signaling pathway in the recovery of neurological function after early ischemic stroke in a rat model.

PubMed

Liu, Yan-Zhi; Wang, Chun; Wang, Qian; Lin, Yong-Zhong; Ge, Yu-Song; Li, Dong-Mei; Mao, Geng-Sheng

2017-09-01

This study aims to explore the role of fractalkine/CX3C chemokine receptor 1 (CX3CR1) signaling pathway in the recovery of neurological functioning after an early ischemic stroke in rats. After establishment of permanent middle cerebral artery occlusion (pMCAO) models, 50 rats were divided into blank, sham, model, positive control and CX3CR1 inhibitor groups. Neurological impairment, walking and grip abilities, and cortical and hippocampal infarctions were evaluated by Zea Longa scoring criterion, beam-walking assay and grip strength test, and diffusion-weighted magnetic resonance imaging. qRT-PCR and Western blotting were performed to detect mRNA and protein expressions. ELISA was conducted to measure concentration of sFractalkine (sFkn), interleukin-1β (IL-1β) and TNF-α. The recovery rate of neurological functioning impairment and reduced walking and grip abilities was faster in the positive control and CX3CR1 inhibitor groups than the model group. The model, positive control and CX3CR1 inhibitor groups showed increased mRNA and protein expression of chemokine C-X3-C motif ligand 1 (CX3CL1) and CX3CR1, concentration of sFkn, IL-1β and TNF-α, and size of cortical and cerebral infarctions while decreased expression of NGF and BDNF compared with the blank and sham groups. Compared with the model group, the mRNA and protein expression of CX3CL1 and CX3CR1, concentration of sFkn, IL-1β and TNF-α, and size of cortical and cerebral infarctions decreased while expression of NGF and BDNF increased in the positive control and CX3CR1 inhibitor groups. Thus, the study suggests that inhibition of fractalkine/CX3CR1 signaling pathway promotes the recovery of neurological functioning after the occurrence of an early ischemic stroke. Copyright © 2017 Elsevier Inc. All rights reserved.

Optimized invertase expression and secretion cassette for improving Yarrowia lipolytica growth on sucrose for industrial applications.

PubMed

Lazar, Zbigniew; Rossignol, Tristan; Verbeke, Jonathan; Crutz-Le Coq, Anne-Marie; Nicaud, Jean-Marc; Robak, Małgorzata

2013-11-01

Yarrowia lipolytica requires the expression of a heterologous invertase to grow on a sucrose-based substrate. This work reports the construction of an optimized invertase expression cassette composed of Saccharomyces cerevisiae Suc2p secretion signal sequence followed by the SUC2 sequence and under the control of the strong Y. lipolytica pTEF promoter. This new construction allows a fast and optimal cleavage of sucrose into glucose and fructose and allows cells to reach the maximum growth rate. Contrary to pre-existing constructions, the expression of SUC2 is not sensitive to medium composition in this context. The strain JMY2593, expressing this new cassette with an optimized secretion signal sequence and a strong promoter, produces 4,519 U/l of extracellular invertase in bioreactor experiments compared to 597 U/l in a strain expressing the former invertase construction. The expression of this cassette strongly improved production of invertase and is suitable for simultaneously high production level of citric acid from sucrose-based media.

Hypothalamic Integration of Metabolic, Endocrine, and Circadian Signals in Fish: Involvement in the Control of Food Intake

PubMed Central

Delgado, María J.; Cerdá-Reverter, José M.; Soengas, José L.

2017-01-01

The regulation of food intake in fish is a complex process carried out through several different mechanisms in the central nervous system (CNS) with hypothalamus being the main regulatory center. As in mammals, a complex hypothalamic circuit including two populations of neurons: one co-expressing neuropeptide Y (NPY) and Agouti-related peptide (AgRP) and the second one population co-expressing pro-opiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript (CART) is involved in the integration of information relating to food intake control. The production and release of these peptides control food intake, and the production results from the integration of information of different nature such as levels of nutrients and hormones as well as circadian signals. The present review summarizes the knowledge and recent findings about the presence and functioning of these mechanisms in fish and their differences vs. the known mammalian model. PMID:28694769

Gene expression analysis by cDNA-AFLP highlights a set of new signaling networks and translational control during seed dormancy breaking in Nicotiana plumbaginifolia.

PubMed

Bove, Jérôme; Lucas, Philippe; Godin, Béatrice; Ogé, Laurent; Jullien, Marc; Grappin, Philippe

2005-03-01

Seed dormancy in Nicotiana plumbaginifolia is characterized by an abscisic acid accumulation linked to a pronounced germination delay. Dormancy can be released by 1 year after-ripening treatment. Using a cDNA-amplified fragment length polymorphism (cDNA-AFLP) approach we compared the gene expression patterns of dormant and after-ripened seeds, air-dry or during one day imbibition and analyzed 15,000 cDNA fragments. Among them 1020 were found to be differentially regulated by dormancy. Of 412 sequenced cDNA fragments, 83 were assigned to a known function by search similarities to public databases. The functional categories of the identified dormancy maintenance and breaking responsive genes, give evidence that after-ripening turns in the air-dry seed to a new developmental program that modulates, at the RNA level, components of translational control, signaling networks, transcriptional control and regulated proteolysis.

Bone morphogenetic protein Smads signaling in mesenchymal stem cells affected by osteoinductive calcium phosphate ceramics.

PubMed

Tang, Zhurong; Wang, Zhe; Qing, Fangzhu; Ni, Yilu; Fan, Yujiang; Tan, Yanfei; Zhang, Xingdong

2015-03-01

Porous calcium phosphate ceramics (CaP ceramics) could induce ectopic bone formation which was regulated by various signal molecules. In this work, bone marrow mesenchymal stem cells (MSCs) were cultured on the surface of osteoinductive hydroxyapatite (HA) and biphasic calcium phosphate (BCP) ceramics in comparison with control (culture plate) for up to 14 days to detect the signal molecules which might be affected by the CaP ceramics. Without adding osteogenic factors, MSCs cultured on HA and BCP both expressed higher Runx2, Osterix, collagen type I, osteopontin, bone sialoprotein, and osteocalcin at various stages compared with control, thus confirmed the osteoblastic differentiation of MSCs. Later study demonstrated the messenger RNA level of bone morphogenetic protein 2 (BMP2) and BMP4 were also significantly enhanced by HA and BCP. Furthermore, Smad1, 4, 5, and Dlx5, the main molecules in the BMP/Smads signaling pathway, were upregulated by HA and BCP. Moreover, the higher expression of Smads and BMP2, 4 in BCP over HA, corresponded to the better performance of BCP in stimulating in vitro osteoblastic differentiation of MSCs. This was in accordance with the better osteoinductivity of BCP over HA in vivo. Altogether, these results implied that the CaP ceramics may initiate the osteoblastic differentiation of MSCs by influencing the expression of molecules in BMP/Smads pathway. © 2014 Wiley Periodicals, Inc.

The Nuclear Receptor AhR Controls Bone Homeostasis by Regulating Osteoclast Differentiation via the RANK/c-Fos Signaling Axis

PubMed Central

Izawa, Takashi; Arakaki, Rieko; Mori, Hiroki; Tsunematsu, Takaaki; Kudo, Yasusei; Tanaka, Eiji

2016-01-01

The aryl hydrocarbon receptor (AhR) pathway plays a key role in receptor activator of NF-κB ligand (RANKL)–mediated osteoclastogenesis. However, the mechanism underlying the regulation of AhR expression in osteoclasts and the signaling pathway through which AhR controls osteoclastogenesis remain unclear. We found that the expression of AhR in bone marrow–derived osteoclasts was upregulated by RANKL at an earlier stage than was the expression of signature osteoclast genes such as those encoding cathepsin K and NFAT, cytoplasmic, calcineurin-dependent 1. In response to RANKL, bone marrow macrophages isolated from AhR−/− mice exhibited impaired phosphorylation of Akt and MAPK as well as NF-κB, whereas their response to M-CSF remained unchanged. Osteoclast differentiation mediated by the AhR signaling pathway was also regulated in an RANKL/c-Fos–dependent manner. Furthermore, ligand activation of AhR by the smoke toxin benzo[a]pyrene accelerated osteoclast differentiation in a receptor-dependent manner, and AhR-dependent regulation of mitochondrial biogenesis in osteoclasts was observed. Moreover, AhR−/− mice exhibited impaired bone healing with delayed endochondral ossification. Taken together, the present results suggest that the RANKL/AhR/c-Fos signaling axis plays a critical role in osteoclastogenesis, thereby identifying the potential of AhR in treating pathological, inflammatory, or metabolic disorders of the bone. PMID:27849171

From deep-sea volcanoes to human pathogens: a conserved quorum-sensing signal in Epsilonproteobacteria

PubMed Central

Pérez-Rodríguez, Ileana; Bolognini, Marie; Ricci, Jessica; Bini, Elisabetta; Vetriani, Costantino

2015-01-01

Chemosynthetic Epsilonproteobacteria from deep-sea hydrothermal vents colonize substrates exposed to steep thermal and redox gradients. In many bacteria, substrate attachment, biofilm formation, expression of virulence genes and host colonization are partly controlled via a cell density-dependent mechanism involving signal molecules, known as quorum sensing. Within the Epsilonproteobacteria, quorum sensing has been investigated only in human pathogens that use the luxS/autoinducer-2 (AI-2) mechanism to control the expression of some of these functions. In this study we showed that luxS is conserved in Epsilonproteobacteria and that pathogenic and mesophilic members of this class inherited this gene from a thermophilic ancestor. Furthermore, we provide evidence that the luxS gene is expressed—and a quorum-sensing signal is produced—during growth of Sulfurovum lithotrophicum and Caminibacter mediatlanticus, two Epsilonproteobacteria from deep-sea hydrothermal vents. Finally, we detected luxS transcripts in Epsilonproteobacteria-dominated biofilm communities collected from deep-sea hydrothermal vents. Taken together, our findings indicate that the epsiloproteobacterial lineage of the LuxS enzyme originated in high-temperature geothermal environments and that, in vent Epsilonproteobacteria, luxS expression is linked to the production of AI-2 signals, which are likely produced in situ at deep-sea vents. We conclude that the luxS gene is part of the ancestral epsilonproteobacterial genome and represents an evolutionary link that connects thermophiles to human pathogens. PMID:25397946

Structure of Peptide Sex Pheromone Receptor PrgX and PrgX/Pheromone Complexes and Regulation of Conjugation in Enterococcus faecalis

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

Shi,K.; Brown, C.; Gu, Z.

2005-01-01

Many bacterial activities, including expression of virulence factors, horizontal genetic transfer, and production of antibiotics, are controlled by intercellular signaling using small molecules. To date, understanding of the molecular mechanisms of peptide-mediated cell-cell signaling has been limited by a dearth of published information about the molecular structures of the signaling components. Here, we present the molecular structure of PrgX, a DNA- and peptide-binding protein that regulates expression of the conjugative transfer genes of the Enterococcus faecalis plasmid pCF10 in response to an intercellular peptide pheromone signal. Comparison of the structures of PrgX and the PrgX/pheromone complex suggests that pheromone bindingmore » destabilizes PrgX tetramers, opening a 70-bp pCF10 DNA loop required for conjugation repression.« less

Stage-specific control of early B cell development by the transcription factor Ikaros

PubMed Central

Gültekin, Sinan; Dakic, Aleksandar; Axelsson, Elin; Minnich, Martina; Ebert, Anja; Werner, Barbara; Roth, Mareike; Cimmino, Luisa; Dickins, Ross A.; Zuber, Johannes; Jaritz, Markus; Busslinger, Meinrad

2018-01-01

Ikaros is an essential regulator of lymphopoiesis. Here, we studied the B-cell-specific function of Ikaros by conditional Ikzf1 inactivation in pro-B cells. B-cell development was arrested at an aberrant ‘pro-B’ cell stage characterized by increased cell adhesion and loss of pre-B cell receptor signaling. Ikaros was found to activate genes coding for pre-BCR signal transducers and to repress genes involved in the downregulation of pre-BCR signaling and upregulation of the integrin signaling pathway. Unexpectedly, derepression of Aiolos expression could not compensate for the loss of Ikaros in pro-B cells. Ikaros induced or suppressed active chromatin at regulatory elements of activated or repressed target genes. Notably, Ikaros binding and target gene expression was dynamically regulated at distinct stages of early B-lymphopoiesis. PMID:24509509

Faster embryonic segmentation through elevated Delta-Notch signalling

PubMed Central

Liao, Bo-Kai; Jörg, David J.; Oates, Andrew C.

2016-01-01

An important step in understanding biological rhythms is the control of period. A multicellular, rhythmic patterning system termed the segmentation clock is thought to govern the sequential production of the vertebrate embryo's body segments, the somites. Several genetic loss-of-function conditions, including the Delta-Notch intercellular signalling mutants, result in slower segmentation. Here, we generate DeltaD transgenic zebrafish lines with a range of copy numbers and correspondingly increased signalling levels, and observe faster segmentation. The highest-expressing line shows an altered oscillating gene expression wave pattern and shortened segmentation period, producing embryos with more, shorter body segments. Our results reveal surprising differences in how Notch signalling strength is quantitatively interpreted in different organ systems, and suggest a role for intercellular communication in regulating the output period of the segmentation clock by altering its spatial pattern. PMID:27302627

Dact2 is expressed in the developing ureteric bud/collecting duct system of the kidney and controls morphogenetic behavior of collecting duct cells.

PubMed

Lee, Wen-Chin; Hough, Melinda T; Liu, Weijia; Ekiert, Robert; Lindström, Nils O; Hohenstein, Peter; Davies, Jamie A

2010-10-01

The overall pattern of the developing kidney is set in large part by the developing ureteric bud/collecting duct system, and dysgenesis of this system accounts for a variety of clinically significant renal diseases. Understanding how the behavior of cells in the developing ureteric bud/collecting duct is controlled is therefore important to understanding the normal and abnormal kidney. Dact proteins have recently been identified as cytoplasmic regulators of intracellular signaling. Dact1 inhibits Wnt signaling, and Dact2 inhibits transforming growth factor (TGF)-β signaling. Here, we report that Dact2 is expressed in developing and adult mouse kidneys, specifically in the ureteric bud/collecting duct epithelium, a structure whose morphogenesis is controlled partially by TGF-β. When small interfering RNA is used to knock down Dact2 expression in collecting duct cells, they show some constitutive phospho-Smad2, undetectable in controls, and elevated phospho-Smad2 in response to TGF-β. They also show defective migration and, in a monolayer wound-healing assay, they fail to assemble a leading edge "cable" of actomyosin and advance instead as a disorganized mass of lamellipodium-bearing cells. This effect is seriously exacerbated by exogenous TGF-β, although control cells tolerate it well. In three-dimensional culture, Dact2 knockdown cells form cysts and branching tubules, but the outlines of the cysts made by knockdown cells are ragged rather than smooth and the branching tubules are decorated with many fine spikes not seen in controls. These data suggest Dact2 plays a role in regulating morphogenesis by renal collecting duct cells, probably by protecting cells from overly strong TGF-β pathway activation.

Hsa-miR-195 targets PCMT1 in hepatocellular carcinoma that increases tumor life span.

PubMed

Amer, Marwa; Elhefnawi, M; El-Ahwany, Eman; Awad, A F; Gawad, Nermen Abdel; Zada, Suher; Tawab, F M Abdel

2014-11-01

MicroRNAs are small 19-25 nucleotides which have been shown to play important roles in the regulation of gene expression in many organisms. Downregulation or accumulation of miRNAs implies either tumor suppression or oncogenic activation. In this study, differentially expressed hsa-miR-195 in hepatocellular carcinoma (HCC) was identified and analyzed. The prediction was done using a consensus approach of tools. The validation steps were done at two different levels in silico and in vitro. FGF7, GHR, PCMT1, CITED2, PEX5, PEX13, NOVA1, AXIN2, and TSPYL2 were detected with high significant (P < 0.005). These genes are involved in important pathways in cancer like MAPK signaling pathway, Jak-STAT signaling pathways, regulation of actin cytoskeleton, angiogenesis, Wnt signaling pathway, and TGF-beta signaling pathway. In vitro target validation was done for protein-L-isoaspartate (D-aspartate) O-methyltransferase (PCMT1). The co-transfection of pmirGLO-PCMT1 and pEGP-miR-195 showed highly significant results. Firefly luciferase was detected using Lumiscensor and t test analysis was done. Firefly luciferase expression was significantly decreased (P < 0.001) in comparison to the control. The low expression of firefly luciferase validates the method of target prediction that we used in this work by working on PCMT1 as a target for miR-195. Furthermore, the rest of the predicted genes are suspected to be real targets for hsa-miR-195. These target genes control almost all the hallmarks of liver cancer which can be used as therapeutic targets in cancer treatment.

Cardiomyocyte Overexpression of FABP4 Aggravates Pressure Overload-Induced Heart Hypertrophy.

PubMed

Zhang, Ji; Qiao, Congzhen; Chang, Lin; Guo, Yanhong; Fan, Yanbo; Villacorta, Luis; Chen, Y Eugene; Zhang, Jifeng

2016-01-01

Fatty acid binding protein 4 (FABP4) is a member of the intracellular lipid-binding protein family, responsible for the transportation of fatty acids. It is considered to express mainly in adipose tissues, and be strongly associated with inflammation, obesity, diabetes and cardiovasculardiseases. Here we report that FABP4 is also expressed in cardiomyocytes and plays an important role in regulating heart function under pressure overload. We generated heart-specific transgenic FABP4 (FABP4-TG) mice using α myosin-heavy chain (α-MHC) promoter and human FABP4 sequence, resulting in over-expression of FABP4 in cardiomyocytes. The FABP4-TG mice displayed normal cardiac morphology and contractile function. When they were subjected to the transverse aorta constriction (TAC) procedure, the FABP4-TG mice developed more cardiac hypertrophy correlated with significantly increased ERK phosphorylation, compared with wild type controls. FABP4 over-expression in cardiomyocytes activated phosphor-ERK signal and up-regulate the expression of cardiac hypertrophic marker genes. Conversely, FABP4 induced phosphor-ERK signal and hypertrophic gene expressions can be markedly inhibited by an ERK inhibitor PD098059 as well as the FABP4 inhibitor BMS309403. These results suggest that FABP4 over-expression in cardiomyocytes can aggravate the development of cardiac hypertrophy through the activation of ERK signal pathway.

Cardiomyocyte Overexpression of FABP4 Aggravates Pressure Overload-Induced Heart Hypertrophy

PubMed Central

Zhang, Ji; Qiao, Congzhen; Chang, Lin; Guo, Yanhong; Fan, Yanbo; Villacorta, Luis; Chen, Y. Eugene; Zhang, Jifeng

2016-01-01

Fatty acid binding protein 4 (FABP4) is a member of the intracellular lipid-binding protein family, responsible for the transportation of fatty acids. It is considered to express mainly in adipose tissues, and be strongly associated with inflammation, obesity, diabetes and cardiovasculardiseases. Here we report that FABP4 is also expressed in cardiomyocytes and plays an important role in regulating heart function under pressure overload. We generated heart-specific transgenic FABP4 (FABP4-TG) mice using α myosin-heavy chain (α-MHC) promoter and human FABP4 sequence, resulting in over-expression of FABP4 in cardiomyocytes. The FABP4-TG mice displayed normal cardiac morphology and contractile function. When they were subjected to the transverse aorta constriction (TAC) procedure, the FABP4-TG mice developed more cardiac hypertrophy correlated with significantly increased ERK phosphorylation, compared with wild type controls. FABP4 over-expression in cardiomyocytes activated phosphor-ERK signal and up-regulate the expression of cardiac hypertrophic marker genes. Conversely, FABP4 induced phosphor-ERK signal and hypertrophic gene expressions can be markedly inhibited by an ERK inhibitor PD098059 as well as the FABP4 inhibitor BMS309403. These results suggest that FABP4 over-expression in cardiomyocytes can aggravate the development of cardiac hypertrophy through the activation of ERK signal pathway. PMID:27294862

PDGF-BB induces vascular smooth muscle cell expression of high molecular weight FGF-2, which accumulates in the nucleus.

PubMed

Pintucci, Giuseppe; Yu, Pey-Jen; Saponara, Fiorella; Kadian-Dodov, Daniella L; Galloway, Aubrey C; Mignatti, Paolo

2005-08-15

Basic fibroblast growth factor (FGF-2) and platelet-derived growth factor (PDGF) are implicated in vascular remodeling secondary to injury. Both growth factors control vascular endothelial and smooth muscle cell proliferation, migration, and survival through overlapping intracellular signaling pathways. In vascular smooth muscle cells PDGF-BB induces FGF-2 expression. However, the effect of PDGF on the different forms of FGF-2 has not been elucidated. Here, we report that treatment of vascular aortic smooth muscle cells with PDGF-BB rapidly induces expression of 20.5 and 21 kDa, high molecular weight (HMW) FGF-2 that accumulates in the nucleus and nucleolus. Conversely, PDGF treatment has little or no effect on 18 kDa, low-molecular weight FGF-2 expression. PDGF-BB-induced upregulation of HMW FGF-2 expression is controlled by sustained activation of extracellular signal-regulated kinase (ERK)-1/2 and is abolished by actinomycin D. These data describe a novel interaction between PDGF-BB and FGF-2, and indicate that the nuclear forms of FGF-2 may mediate the effect of PDGF activity on vascular smooth muscle cells.

Elevated Peritoneal Fluid TNF-α Incites Ovarian Early Growth Response Factor 1 Expression and Downstream Protease Mediators

PubMed Central

Birt, Julie A.; Nabli, Henda; Stilley, Julie A.; Windham, Emma A.; Frazier, Shellaine R.

2013-01-01

Endometriosis-associated infertility manifests itself via multiple, poorly understood mechanisms. Our goal was to characterize signaling pathways, between peritoneal endometriotic lesions and the ovary, leading to failed ovulation. Genome-wide microarray analysis comparing ovarian tissue from an in vivo endometriosis model in the rat (Endo) with controls (Sham) identified 22 differentially expressed genes, including transiently expressed early growth response factor 1 (Egr1). The Egr1 regulates gene requisites for ovulation. The Egr1 promoter is responsive to tumor necrosis factor-alpha (TNF-α) signaling. We hypothesized that altered expression of ovarian EGR1 is induced by elevated peritoneal fluid TNF-α which is upregulated by the presence of peritoneal endometriosis. Endo rats, compared to controls, had more peritoneal fluid TNF-α and quantitative, spatial differences in Egr1 mRNA and EGR1 protein localization in follicular compartments. Interactions between elevated peritoneal fluid TNF-α and overexpression of follicular Egr1/EGR1 expression may affect downstream protease pathways impeding ovulation in endometriosis. Preliminary studies identified similar patterns of EGR1 protein localization in human ovaries from women with endometriosis and compared to those without endometriosis. PMID:23427178

STAT5 Activation in the Dermal Papilla Is Important for Hair Follicle Growth Phase Induction.

PubMed

Legrand, Julien M D; Roy, Edwige; Ellis, Jonathan J; Francois, Mathias; Brooks, Andrew J; Khosrotehrani, Kiarash

2016-09-01

Hair follicles are skin appendages that undergo periods of growth (anagen), regression (catagen), and rest (telogen) regulated by their mesenchymal component, the dermal papilla (DP). On the basis of the reports of its specific expression in the DP, we investigated signal transducer and activator of transcription (STAT5) activation during hair development and cycling. STAT5 activation in the DP began in late catagen, reaching a peak in early anagen before disappearing for the rest of the cycle. This was confirmed by the expression profile of suppressor of cytokine signaling 2, a STAT5 target in the DP. This pattern of expression starts after the first postnatal hair cycle. Quantification of hair cycling using the Flash canonical Wnt signaling in vivo bioluminescence reporter found that conditional knockout of STAT5A/B in the DP targeted through Cre-recombinase under the control of the Sox18 promoter resulted in delayed anagen entry compared with control. Microarray analysis of STAT5 deletion versus control revealed key changes in tumor necrosis factor-α, Wnt, and fibroblast growth factor ligands, known for their role in inducing anagen entry. We conclude that STAT5 activation acts as a mesenchymal switch to trigger natural anagen entry in postdevelopmental hair follicle cycling. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Msx Homeobox Genes Critically Regulate Embryo Implantation by Controlling Paracrine Signaling between Uterine Stroma and Epithelium

PubMed Central

Nallasamy, Shanmugasundaram; Li, Quanxi; Bagchi, Milan K.; Bagchi, Indrani C.

2012-01-01

The mammalian Msx homeobox genes, Msx1 and Msx2, encode transcription factors that control organogenesis and tissue interactions during embryonic development. We observed overlapping expression of these factors in uterine epithelial and stromal compartments of pregnant mice prior to embryo implantation. Conditional ablation of both Msx1 and Msx2 in the uterus resulted in female infertility due to a failure in implantation. In these mutant mice (Msx1/2 d/d), the uterine epithelium exhibited persistent proliferative activity and failed to attach to the embryos. Gene expression profiling of uterine epithelium and stroma of Msx1/2 d/d mice revealed an elevated expression of several members of the Wnt gene family in the preimplantation uterus. Increased canonical Wnt signaling in the stromal cells activated β-catenin, stimulating the production of a subset of fibroblast growth factors (FGFs) in these cells. The secreted FGFs acted in a paracrine manner via the FGF receptors in the epithelium to promote epithelial proliferation, thereby preventing differentiation of this tissue and creating a non-receptive uterus refractory to implantation. Collectively, these findings delineate a unique signaling network, involving Msx1/2, Wnts, and FGFs, which operate in the uterus at the time of implantation to control the mesenchymal-epithelial dialogue critical for successful establishment of pregnancy. PMID:22383889

Role of enteric nerves in immune-mediated changes in protease activated receptor 2 effects on gut function

USDA-ARS?s Scientific Manuscript database

Protease activated receptors (PARs) are expressed on structural cells and immune cells. Control of the initiation, duration, and magnitude of the PAR effects are linked to the level of receptor expression, the availability of proteases, and the intracellular signal transduction machinery. We inve...

Cortistatin Is a Key Factor Regulating the Sex-Dependent Response of the GH and Stress Axes to Fasting in Mice.

PubMed

Cordoba-Chacón, José; Gahete, Manuel D; Pozo-Salas, Ana I; de Lecea, Luis; Castaño, Justo P; Luque, Raúl M

2016-07-01

Cortistatin (CORT) shares high structural and functional similarities with somatostatin (SST) but displays unique sex-dependent pituitary actions. Indeed, although female CORT-knockout (CORT-KO) mice exhibit enhanced GH expression/secretion, Proopiomelanocortin expression, and circulating ACTH/corticosterone/ghrelin levels, male CORT-KO mice only display increased plasma GH/corticosterone levels. Changes in peripheral ghrelin and SST (rather than hypothalamic levels) seem to regulate GH/ACTH axes in CORT-KOs under fed conditions. Because changes in GH/ACTH axes during fasting provide important adaptive mechanisms, we sought to determine whether CORT absence influences GH/ACTH axes during fasting. Accordingly, fed and fasted male/female CORT-KO were compared with littermate controls. Fasting increased circulating GH levels in male/female controls but not in CORT-KO, suggesting that CORT can be a relevant regulator of GH secretion during fasting. However, GH levels were already higher in CORT-KO than in controls in fed state, which might preclude a further elevation in GH levels. Interestingly, although fasting-induced pituitary GH expression was elevated in both male/female controls, GH expression only increased in fasted female CORT-KOs, likely owing to specific changes observed in key factors controlling somatotrope responsiveness (ie, circulating ghrelin and IGF-1, and pituitary GHRH and ghrelin receptor expression). Fasting increased corticosterone levels in control and, most prominently, in CORT-KO mice, which might be associated with a desensitization to SST signaling and to an augmentation in CRH and ghrelin-signaling regulating corticotrope function. Altogether, these results provide compelling evidence that CORT plays a key, sex-dependent role in the regulation of the GH/ACTH axes in response to fasting.

Small RNAs, big impact: small RNA pathways in transposon control and their effect on the host stress response.

PubMed

Wheeler, Bayly S

2013-12-01

Transposons are mobile genetic elements that are a major constituent of most genomes. Organisms regulate transposable element expression, transposition, and insertion site preference, mitigating the genome instability caused by uncontrolled transposition. A recent burst of research has demonstrated the critical role of small non-coding RNAs in regulating transposition in fungi, plants, and animals. While mechanistically distinct, these pathways work through a conserved paradigm. The presence of a transposon is communicated by the presence of its RNA or by its integration into specific genomic loci. These signals are then translated into small non-coding RNAs that guide epigenetic modifications and gene silencing back to the transposon. In addition to being regulated by the host, transposable elements are themselves capable of influencing host gene expression. Transposon expression is responsive to environmental signals, and many transposons are activated by various cellular stresses. TEs can confer local gene regulation by acting as enhancers and can also confer global gene regulation through their non-coding RNAs. Thus, transposable elements can act as stress-responsive regulators that control host gene expression in cis and trans.

Prox1 and fibroblast growth factor receptors form a novel regulatory loop controlling lens fiber differentiation and gene expression

PubMed Central

Audette, Dylan S.; Anand, Deepti; So, Tammy; Rubenstein, Troy B.; Lachke, Salil A.; Lovicu, Frank J.; Duncan, Melinda K.

2016-01-01

Lens epithelial cells differentiate into lens fibers (LFs) in response to a fibroblast growth factor (FGF) gradient. This cell fate decision requires the transcription factor Prox1, which has been hypothesized to promote cell cycle exit in differentiating LF cells. However, we find that conditional deletion of Prox1 from mouse lenses results in a failure in LF differentiation despite maintenance of normal cell cycle exit. Instead, RNA-seq demonstrated that Prox1 functions as a global regulator of LF cell gene expression. Intriguingly, Prox1 also controls the expression of fibroblast growth factor receptors (FGFRs) and can bind to their promoters, correlating with decreased downstream signaling through MAPK and AKT in Prox1 mutant lenses. Further, culturing rat lens explants in FGF increased their expression of Prox1, and this was attenuated by the addition of inhibitors of MAPK. Together, these results describe a novel feedback loop required for lens differentiation and morphogenesis, whereby Prox1 and FGFR signaling interact to mediate LF differentiation in response to FGF. PMID:26657765

Prox1 and fibroblast growth factor receptors form a novel regulatory loop controlling lens fiber differentiation and gene expression.

PubMed

Audette, Dylan S; Anand, Deepti; So, Tammy; Rubenstein, Troy B; Lachke, Salil A; Lovicu, Frank J; Duncan, Melinda K

2016-01-15

Lens epithelial cells differentiate into lens fibers (LFs) in response to a fibroblast growth factor (FGF) gradient. This cell fate decision requires the transcription factor Prox1, which has been hypothesized to promote cell cycle exit in differentiating LF cells. However, we find that conditional deletion of Prox1 from mouse lenses results in a failure in LF differentiation despite maintenance of normal cell cycle exit. Instead, RNA-seq demonstrated that Prox1 functions as a global regulator of LF cell gene expression. Intriguingly, Prox1 also controls the expression of fibroblast growth factor receptors (FGFRs) and can bind to their promoters, correlating with decreased downstream signaling through MAPK and AKT in Prox1 mutant lenses. Further, culturing rat lens explants in FGF increased their expression of Prox1, and this was attenuated by the addition of inhibitors of MAPK. Together, these results describe a novel feedback loop required for lens differentiation and morphogenesis, whereby Prox1 and FGFR signaling interact to mediate LF differentiation in response to FGF. © 2016. Published by The Company of Biologists Ltd.

Correlation of the expression of CD32 and CD180 receptors on CLL cells and MEC1 cell line.

PubMed

Tsertsvadze, T; Mitskevich, N; Ghirdaladze, D; Porakishvili, N

2015-03-01

Chronic Lymphocytic Leukemia (CLL) presents with clonal expansion and accumulation of CD5+CD19+CD23+ cells in peripheral lymphoid organs and tissues and in bone marrow. CLL is supposedly driven by exogenous and/or endogenous (auto)antigen(s) and there is increasing evidence that CLL cells receive microenvironmental signals which support their growth, survival and expansion in vivo. We have previously shown that powerful signals are received by CLL cells through CD180 orphan toll-like receptor. Additional accessory signals could be generated through FcγRII (CD32), since both are expressed on CLL cells as well as on control B cells. Here we studied correlation of the expression of CD32 and CD180 on CLL cells as well as on MEC1 cell line. Peripheral blood mononuclear cells (PBMC) from CLL patients and age-matched healthy volunteers were separated, stained with appropriate antibodies to CD19, CD32 and CD180 and analysed by flow cytometry. CD32 and CD180 expression on MEC1 cells was studied at different time-points. The data was statistically analysed using the Mann-Whitney non-parametrical test. Our data indicates that expression of CD32 is significantly increased on CLL cells compared to control B cells as well as in long-term MEC1 cell culture. In contrast, CD180 expression on MEC1 cells significantly decreased throughout 0-96h of MEC1 cell culture. We have recently shown that CD180 ligation can redirect sIgM-mediated signaling from pro-survival to pro-apoptotic. This data indicates that a drop in the expression of CD180 on cycling CLL cells might lead to a weakening of this effect and enhance further survival and expansion of CLL cells in proliferative centres of lymphoid tissues. Since MEC1 cells are derived from a CLL patient with mutated IGVH genes (M-CLL) negative correlation between CD180 and CD32 expression on cycling MEC1 cells could be limited to M-CLL.

Decreased miR-199 augments visceral pain in patients with IBS through translational upregulation of TRPV1.

PubMed

Zhou, QiQi; Yang, Liuqing; Larson, Scott; Basra, Sapreet; Merwat, Shehzad; Tan, Alai; Croce, Carlo; Verne, G Nicholas

2016-05-01

Many patients with irritable bowel syndrome IBS not only have abdominal pain but also may suffer from visceral hypersensitivity and heighted visceral nociception. Moreover, IBS has few effective therapeutic agents and mechanisms of disease are unclear. Our goals were to (i) identify microRNA (miRNA) expression, signalling and targets in human colon (controls; patients with IBS); (ii) verify in vitro, IBS-associated changes in miRNAs, especially miR-199, which is complementary to the transient receptor potential vanilloid type 1 (TRPV1) gene; and (iii) determine whether modulating the expression of miRNAs in vivo, especially miR-199, reverses associated changes and pathological hallmarks of visceral hypersensitivity via TRPV1 signalling. We evaluated 45 patients with diarrhoea-predominant IBS (IBS-D) and 40 controls with (1) visceral pain severity score and (2) colonoscopy with biopsies. miRNA expression was evaluated in human colon following miRNA array analysis. Luciferase assays were done to confirm relationships between miR-199 and TRPV1 expression. A rat model of visceral hypersensitivity was used to study miR-199 and its target gene (TRPV1) expression in dorsal root ganglion (DRG) and colon in vivo. Gut miR-199a/b expression in IBS-D was significantly decreased, which correlated directly with both increased visceral pain scores and TRPV1 expression. In vivo upregulation of miR-199a by intraperitoneal injection of lenti-miR-199a precursors decreased visceral hypersensitivity via diminished TRPV1 signalling. Decreased colonic miR-199a/b correlates with visceral pain in patients with IBS-D. Similarly, reduced miR-199a expression in rat DRG and colon tissue is associated with heightened visceral hypersensitivity. In vivo upregulation of miR-199a decreases visceral pain via inhibition of TRPV1 signalling. Thus, miR-199 precursors may be promising therapeutic candidates for the treatment in patients with visceral pain. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

The expression and crucial roles of BMP signaling in development of smooth muscle progenitor cells in the mouse embryonic gut.

PubMed

Torihashi, Shigeko; Hattori, Takako; Hasegawa, Hirotaka; Kurahashi, Masaaki; Ogaeri, Takunori; Fujimoto, Toyoshi

2009-03-01

Bone morphogenetic protein (BMP) signaling is essential for normal development of the gastrointestinal (GI) tract. BMPs also play multiple roles in vascular smooth muscle cells; however, the BMP signaling in the development of the GI musculature remains to be clarified. We investigated the expression of BMPs and their receptors in mouse embryonic GI tracts by immunohistochemistry and in situ hybridization. We demonstrated that BMP2, BMP receptor Ib and BMP receptor II were expressed in the smooth muscle progenitors from E12 to E13 for the first time. BMP signaling on smooth muscle differentiation was examined by implantation of agarose beads soaked with BMPs in the in vitro developmental model that is gut-like structures from mouse embryonic stem (ES) cells. BMP2 rather than BMP4 beads enhanced smooth muscle differentiation, and increased gut-like structures showing spontaneous contractions and expressing intensive alpha-smooth muscle actin immunoreactivity. This increase was confirmed by up-regulation of SM22 mRNA shown by real-time PCR. By addition of noggin beads or noggin to the medium at BMP2 bead implantation, the ratio of contractive gut-like structures decreased. Implantation of BMP2 beads at EB7 (EB--embryoid bodies) (corresponding to E12 or E13 of mouse embryo) showed the highest effects and up-regulation of transcription factors msx-1 after 24h. This increase was blocked by noggin, and msx-1 decreased to almost the control level after 60 h. BMP2 beads at EB7 increased platelet-derived growth factor-A (PDGF-A) in the differentiating smooth muscle cells. We have recently reported that PDGF-A is expressed in the developing inner circular smooth muscle and is crucial for the longitudinal smooth muscle differentiation. Taken together, BMP signaling was expressed for a short window in the smooth muscle progenitors and the signal, especially BMP2, plays an essential role in smooth muscle differentiation in cooperation with PDGF signaling.

Type I γ Phosphatidylinositol Phosphate 5-Kinase i5 Controls the Ubiquitination and Degradation of the Tumor Suppressor Mitogen-inducible Gene 6.

PubMed

Sun, Ming; Cai, Jinyang; Anderson, Richard A; Sun, Yue

2016-10-07

Mitogen-inducible gene 6 (Mig6) is a tumor suppressor, and the disruption of Mig6 expression is associated with cancer development. Mig6 directly interacts with epidermal growth factor receptor (EGFR) to suppress the activation and downstream signaling of EGFR. Therefore, loss of Mig6 enhances EGFR-mediated signaling and promotes EGFR-dependent carcinogenesis. The molecular mechanism modulating Mig6 expression in cancer remains unclear. Here we demonstrate that type I γ phosphatidylinositol phosphate 5-kinase i5 (PIPKIγi5), an enzyme producing phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P 2 ), stabilizes Mig6 expression. Knockdown of PIPKIγi5 leads to the loss of Mig6 expression, which dramatically enhances and prolongs EGFR-mediated cell signaling. Loss of PIPKIγi5 significantly promotes Mig6 protein degradation via proteasomes, but it does not affect the Mig6 mRNA level. PIPKIγi5 directly interacts with the E3 ubiquitin ligase neuronal precursor cell-expressed developmentally down-regulated 4-1 (NEDD4-1). The C-terminal domain of PIPKIγi5 and the WW1 and WW2 domains of NEDD4-1 are required for their interaction. The C2 domain of NEDD4-1 is required for its interaction with PtdIns(4,5)P 2 By binding with NEDD4-1 and producing PtdIns(4,5)P 2 , PIPKIγi5 perturbs NEDD4-1-mediated Mig6 ubiquitination and the subsequent proteasomal degradation. Thus, loss of NEDD4-1 can rescue Mig6 expression in PIPKIγi5 knockdown cells. In this way, PIPKIγi5, NEDD4-1, and Mig6 form a novel molecular nexus that controls EGFR activation and downstream signaling. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

T Cell Receptor Signaling in the Control of Regulatory T Cell Differentiation and Function

PubMed Central

Li, Ming O.; Rudensky, Alexander Y.

2016-01-01

Regulatory T cells (TReg cells), a specialized T cell lineage, have a pivotal function in the control of self-tolerance and inflammatory responses. Recent studies have revealed a discrete mode of TCR signaling that regulates Treg cell differentiation, maintenance and function and that impacts on gene expression, metabolism, cell adhesion and migration of these cells. Here, we discuss the emerging understanding of TCR-guided differentiation of Treg cells in the context of their function in health and disease. PMID:27026074

Integration of Nuclear- and Extranuclear-Initiated Estrogen Receptor Signaling in Breast Cancer Cells

ERIC Educational Resources Information Center

Madak Erdogan, Zeynep

2009-01-01

Estrogenic hormones exert their effects through binding to Estrogen Receptors (ERs), which work in concert with coregulators and extranuclear signaling pathways to control gene expression in normal as well as cancerous states, including breast tumors. In this thesis, we have used multiple genome-wide analysis tools to elucidate various ways that…

Transcriptional response of dermal fibroblasts in direct current electric fields.

PubMed

Jennings, Jessica; Chen, Dongquan; Feldman, Dale

2008-07-01

During the course of normal wound healing, fibroblasts at the wound edge are exposed to electric fields (EFs) ranging from 40 to 200 mV/mm. Various forms of EFs influence fibroblast migration, proliferation, and protein synthesis. Thus, EFs may contribute to fibroblast activation during wound repair. To elucidate the role of EFs during the normal progression of healing, this study compares gene expression in normal adult dermal fibroblasts exposed to a 100 mV/mm EF for 1 h to non-stimulated controls. Significantly increased expression of 162 transcripts and decreased expression of 302 transcripts was detected using microarrays, with 126 transcripts above the level of 1.4-fold increases or decreases compared to the controls. Above the level of twofold, only 11 genes were significantly increased or decreased compared to controls. Many of these significantly regulated genes are associated with wound repair through the processes of matrix production, cellular signaling, and growth. Activity within specific cellular signaling pathways is noted, including TGF-beta, G-proteins, and inhibition of apoptosis. In addition, RT-PCR analysis of the expression of KLF6, FN1, RGS2, and JMJD1C over continued stimulation and at different field strengths suggests that there are specific windows of field characteristics for maximum induction of these genes. EFs thus appear to have an important role in controlling fibroblast activity in the process of wound healing.

Partial Müllerian Duct Retention in Smad4 Conditional Mutant Male Mice.

PubMed

Petit, Fabrice G; Deng, Chuxia; Jamin, Soazik P

2016-01-01

Müllerian duct regression is a complex process which involves the AMH signalling pathway. We have previously demonstrated that besides AMH and its specific type II receptor (AMHRII), BMPR-IA and Smad5 are two essential factors implicated in this mechanism. Mothers against decapentaplegic homolog 4 (Smad4) is a transcription factor and the common Smad (co-Smad) involved in transforming growth factor beta (TGF-β) signalling pathway superfamily. Since Smad4 null mutants die early during gastrulation, we have inactivated Smad4 in the Müllerian duct mesenchyme. Specific inactivation of Smad4 in the urogenital ridge leads to the partial persistence of the Müllerian duct in adult male mice. Careful examination of the urogenital tract reveals that the Müllerian duct retention is randomly distributed either on one side or both sides. Histological analysis shows a uterus-like structure, which is confirmed by the expression of estrogen receptor α. As previously described in a β-catenin conditional mutant mouse model, β-catenin contributes to Müllerian duct regression. In our mutant male embryos, it appears that β-catenin expression is locally reduced along the urogenital ridge as compared to control mice. Moreover, the expression pattern is similar to those observed in control female mice. This study shows that reduced Smad4 expression disrupts the Wnt/β-catenin signalling leading to the partial persistence of Müllerian duct.

Impaired insulin signaling pathway in ovarian follicles of cows with cystic ovarian disease.

PubMed

Hein, G J; Panzani, C G; Rodríguez, F M; Salvetti, N R; Díaz, P U; Gareis, N C; Benítez, G A; Ortega, H H; Rey, F

2015-05-01

Cystic ovarian disease (COD) is an important cause of infertility in dairy cattle. Follicular cell steroidogenesis and proliferation in ovulatory follicles is stimulated by hormones such as insulin and its necessary post-receptor response. The aim of this study was to determine the expression of insulin receptor (IR), IR substrate-1 (IRS1) and phosphatidylinositol 3-kinase (PI3K), key intermediates in the insulin pathway, in control cows and cows with spontaneous COD and ACTH-induced COD. IR and IRS1 mRNA levels were greater in granulosa cells and lower in follicular cysts than in control tertiary follicles. PI3K mRNA levels were similar in all follicles evaluated, whereas the expression of IR, IRS1 and PI3K was similar in theca cells. Protein expression of IR was higher in control tertiary follicles than in the same structures in animals with COD and with cysts. IRS1 and PI3K protein expression showed the same pattern in tertiary and cystic follicles. However, the protein expression of subunit alpha p85 of PI3K was greater in theca cells from tertiary follicles than in cystic follicles. These results provide new insights into the insulin response in cows with COD. The lower gene and protein expressions of some insulin downstream effectors at an early stage of the signaling pathway could negatively influence the functionality of ovaries and contribute to follicle persistence. Copyright © 2015 Elsevier B.V. All rights reserved.

crm-1 facilitates BMP signaling to control body size in Caenorhabditis elegans.

PubMed

Fung, Wong Yan; Fat, Ko Frankie Chi; Eng, Cheah Kathryn Song; Lau, Chow King

2007-11-01

We have identified in Caenorhabditis elegans a homologue of the vertebrate Crim1, crm-1, which encodes a putative transmembrane protein with multiple cysteine-rich (CR) domains known to have bone morphogenetic proteins (BMPs) binding activity. Using the body morphology of C. elegans as an indicator, we showed that attenuation of crm-1 activity leads to a small body phenotype reminiscent of that of BMP pathway mutants. We showed that the crm-1 loss-of-function phenotype can be rescued by constitutive supply of sma-4 activity. crm-1 can enhance BMP signaling and this activity is dependent on the presence of the DBL-1 ligand and its receptors. crm-1 is expressed in neurons at the ventral nerve cord, where the DBL-1 ligand is produced. However, ectopic expression experiments reveal that crm-1 gene products act outside the DBL-1 producing cells and function non-autonomously to facilitate dbl/sma pathway signaling to control body size.

PAF-Myc-Controlled Cell Stemness Is Required for Intestinal Regeneration and Tumorigenesis.

PubMed

Kim, Moon Jong; Xia, Bo; Suh, Han Na; Lee, Sung Ho; Jun, Sohee; Lien, Esther M; Zhang, Jie; Chen, Kaifu; Park, Jae-Il

2018-03-12

The underlying mechanisms of how self-renewing cells are controlled in regenerating tissues and cancer remain ambiguous. PCNA-associated factor (PAF) modulates DNA repair via PCNA. Also, PAF hyperactivates Wnt/β-catenin signaling independently of PCNA interaction. We found that PAF is expressed in intestinal stem and progenitor cells (ISCs and IPCs) and markedly upregulated during intestinal regeneration and tumorigenesis. Whereas PAF is dispensable for intestinal homeostasis, upon radiation injury, genetic ablation of PAF impairs intestinal regeneration along with the severe loss of ISCs and Myc expression. Mechanistically, PAF conditionally occupies and transactivates the c-Myc promoter, which induces the expansion of ISCs/IPCs during intestinal regeneration. In mouse models, PAF knockout inhibits Apc inactivation-driven intestinal tumorigenesis with reduced tumor cell stemness and suppressed Wnt/β-catenin signaling activity, supported by transcriptome profiling. Collectively, our results unveil that the PAF-Myc signaling axis is indispensable for intestinal regeneration and tumorigenesis by positively regulating self-renewing cells. Copyright © 2018 Elsevier Inc. All rights reserved.

A cascade of morphogenic signaling initiated by the meninges controls corpus callosum formation.

PubMed

Choe, Youngshik; Siegenthaler, Julie A; Pleasure, Samuel J

2012-02-23

The corpus callosum is the most prominent commissural connection between the cortical hemispheres, and numerous neurodevelopmental disorders are associated with callosal agenesis. By using mice either with meningeal overgrowth or selective loss of meninges, we have identified a cascade of morphogenic signals initiated by the meninges that regulates corpus callosum development. The meninges produce BMP7, an inhibitor of callosal axon outgrowth. This activity is overcome by the induction of expression of Wnt3 by the callosal pathfinding neurons, which antagonize the inhibitory effects of BMP7. Wnt3 expression in the cingulate callosal pathfinding axons is developmentally regulated by another BMP family member, GDF5, which is produced by the adjacent Cajal-Retzius neurons and turns on before outgrowth of the callosal axons. The effects of GDF5 are in turn under the control of a soluble GDF5 inhibitor, Dan, made by the meninges. Thus, the meninges and medial neocortex use a cascade of signals to regulate corpus callosum development. Copyright © 2012 Elsevier Inc. All rights reserved.

A cascade of morphogenic signaling initiated by the meninges controls corpus callosum formation

PubMed Central

Choe, Youngshik; Siegenthaler, Julie A.; Pleasure, Samuel J.

2012-01-01

Summary The corpus callosum is the most prominent commissural connection between the cortical hemispheres, and numerous neurodevelopmental disorders are associated with callosal agenesis. Using mice with either meningeal overgrowth or selective loss of meninges, we’ve identified a cascade of morphogenic signals initiated by the meninges that regulates corpus callosum development. The meninges produce BMP7, an inhibitor of callosal axon outgrowth. This activity is overcome by the induction of expression of Wnt3 by the callosal pathfinding neurons, which antagonizes the inhibitory effects of BMP7. Wnt3 expression in the cingulate callosal pathfinding axons is developmentally regulated by another BMP family member, GDF5, produced by the adjacent Cajal-Retzius neurons and turns on before outgrowth of the callosal axons. The effects of GDF5 are in turn under the control of a soluble GDF5 inhibitor, Dan, made by the meninges. Thus, the meninges and medial neocortex use a cascade of signals to regulate corpus callosum development. PMID:22365545

Methylation-reprogrammed Wnt/β-catenin signalling mediated prenatal hypoxia-induced brain injury in foetal and offspring rats.

PubMed

Zhang, Yingying; Zhang, Mengshu; Li, Lingjun; Wei, Bin; He, Axin; Lu, Likui; Li, Xiang; Zhang, Lubo; Xu, Zhice; Sun, Miao

2018-05-28

Prenatal hypoxia (PH) is a common pregnancy complication, harmful to brain development. This study investigated whether and how PH affected Wnt pathway in the brain. Pregnant rats were exposed to hypoxia (10.5% O 2 ) or normoxia (21% O 2 ; Control). Foetal brain weight and body weight were decreased in the PH group, the ratio of brain weight to body weight was increased significantly. Prenatal hypoxia increased mRNA expression of Wnt3a, Wnt7a, Wnt7b and Fzd4, but not Lrp6. Activated β-catenin protein and Fosl1 expression were also significantly up-regulated. Increased Hif1a expression was found in the PH group associated with the higher Wnt signalling. Among 5 members of the Sfrp family, Sfrp4 was down-regulated. In the methylation-regulating genes, higher mRNA expressions of Dnmt1 and Dnmt3b were found in the PH group. Sodium bisulphite and sequencing revealed hyper-methylation in the promoter region of Sfrp4 gene in the foetal brain, accounting for its decreased expression and contributing to the activation of the Wnt-Catenin signalling. The study of PC12 cells treated with 5-aza further approved that decreased methylation could result in the higher Sfrp4 expression. In the offspring hippocampus, protein levels of Hif1a and mRNA expression of Sfrp4 were unchanged, whereas Wnt signal pathway was inhibited. The data demonstrated that PH activated the Wnt pathway in the foetal brain, related to the hyper-methylation of Sfrp4 as well as Hif1a signalling. Activated Wnt signalling might play acute protective roles to the foetal brain in response to hypoxia, also would result in disadvantageous influence on the offspring in long-term. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

The merged basins of signal transduction pathways in spatiotemporal cell biology.

PubMed

Hou, Yingchun; Hou, Yang; He, Siyu; Ma, Caixia; Sun, Mengyao; He, Huimin; Gao, Ning

2014-03-01

Numerous evidences have indicated that a signal system is composed by signal pathways, each pathway is composed by sub-pathways, and the sub-pathway is composed by the original signal terminals initiated with a protein/gene. We infer the terminal signals merged signal transduction system as "signal basin". In this article, we discussed the composition and regulation of signal basins, and the relationship between the signal basin control and triple W of spatiotemporal cell biology. Finally, we evaluated the importance of the systemic regulation to gene expression by signal basins under triple W. We hope our discussion will be the beginning to cause the attention for this area from the scientists of life science. © 2013 Wiley Periodicals, Inc.

Transcript Profiling Identifies Gene Cohorts Controlled by Each Signal Regulating Trans-Differentiation of Epidermal Cells of Vicia faba Cotyledons to a Transfer Cell Phenotype

PubMed Central

Zhang, Hui-Ming; Wheeler, Simon L.; Xia, Xue; Colyvas, Kim; Offler, Christina E.; Patrick, John W.

2017-01-01

Transfer cells (TCs) support high rates of membrane transport of nutrients conferred by a plasma membrane area amplified by lining a wall labyrinth comprised of an uniform wall layer (UWL) upon which intricate wall ingrowth (WI) papillae are deposited. A signal cascade of auxin, ethylene, extracellular hydrogen peroxide (H2O2) and cytosolic Ca2+ regulates wall labyrinth assembly. To identify gene cohorts regulated by each signal, a RNA- sequencing study was undertaken using Vicia faba cotyledons. When cotyledons are placed in culture, their adaxial epidermal cells spontaneously undergo trans-differentiation to epidermal TCs (ETCs). Expressed genes encoding proteins central to wall labyrinth formation (signaling, intracellular organization, cell wall) and TC function of nutrient transport were assembled. Transcriptional profiles identified 9,742 annotated ETC-specific differentially expressed genes (DEGs; Log2fold change > 1; FDR p ≤ 0.05) of which 1,371 belonged to signaling (50%), intracellular organization (27%), cell wall (15%) and nutrient transporters (9%) functional categories. Expression levels of 941 ETC-specific DEGs were found to be sensitive to the known signals regulating ETC trans-differentiation. Significantly, signals acting alone, or in various combinations, impacted similar numbers of ETC-specific DEGs across the four functional gene categories. Amongst the signals acting alone, H2O2 exerted most influence affecting expression levels of 56% of the ETC-specific DEGs followed by Ca2+ (21%), auxin (18%) and ethylene (5%). The dominance by H2O2 was evident across all functional categories, but became more attenuated once trans-differentiation transitioned into WI papillae formation. Amongst the eleven signal combinations, H2O2/Ca2+ elicited the greatest impact across all functional categories accounting for 20% of the ETC-specific DEG cohort. The relative influence of the other signals acting alone, or in various combinations, varied across the four functional categories and two phases of wall labyrinth construction. These transcriptome data provide a powerful information platform from which to examine signal transduction pathways and how these regulate expression of genes encoding proteins engaged in intracellular organization, cell wall construction and nutrient transport. PMID:29234338

Transcript Profiling Identifies Gene Cohorts Controlled by Each Signal Regulating Trans-Differentiation of Epidermal Cells of Vicia faba Cotyledons to a Transfer Cell Phenotype.

PubMed

Zhang, Hui-Ming; Wheeler, Simon L; Xia, Xue; Colyvas, Kim; Offler, Christina E; Patrick, John W

2017-01-01

Transfer cells (TCs) support high rates of membrane transport of nutrients conferred by a plasma membrane area amplified by lining a wall labyrinth comprised of an uniform wall layer (UWL) upon which intricate wall ingrowth (WI) papillae are deposited. A signal cascade of auxin, ethylene, extracellular hydrogen peroxide (H 2 O 2 ) and cytosolic Ca 2+ regulates wall labyrinth assembly. To identify gene cohorts regulated by each signal, a RNA- sequencing study was undertaken using Vicia faba cotyledons. When cotyledons are placed in culture, their adaxial epidermal cells spontaneously undergo trans -differentiation to epidermal TCs (ETCs). Expressed genes encoding proteins central to wall labyrinth formation (signaling, intracellular organization, cell wall) and TC function of nutrient transport were assembled. Transcriptional profiles identified 9,742 annotated ETC-specific differentially expressed genes (DEGs; Log 2 fold change > 1; FDR p ≤ 0.05) of which 1,371 belonged to signaling (50%), intracellular organization (27%), cell wall (15%) and nutrient transporters (9%) functional categories. Expression levels of 941 ETC-specific DEGs were found to be sensitive to the known signals regulating ETC trans -differentiation. Significantly, signals acting alone, or in various combinations, impacted similar numbers of ETC-specific DEGs across the four functional gene categories. Amongst the signals acting alone, H 2 O 2 exerted most influence affecting expression levels of 56% of the ETC-specific DEGs followed by Ca 2+ (21%), auxin (18%) and ethylene (5%). The dominance by H 2 O 2 was evident across all functional categories, but became more attenuated once trans -differentiation transitioned into WI papillae formation. Amongst the eleven signal combinations, H 2 O 2 /Ca 2+ elicited the greatest impact across all functional categories accounting for 20% of the ETC-specific DEG cohort. The relative influence of the other signals acting alone, or in various combinations, varied across the four functional categories and two phases of wall labyrinth construction. These transcriptome data provide a powerful information platform from which to examine signal transduction pathways and how these regulate expression of genes encoding proteins engaged in intracellular organization, cell wall construction and nutrient transport.

A systems-based approach to analyse the host response in murine lung macrophages challenged with respiratory syncytial virus

PubMed Central

2013-01-01

Background Respiratory syncytial virus (RSV) is an important cause of lower respiratory tract infection in young children. The degree of disease severity is determined by the host response to infection. Lung macrophages play an important early role in the host response to infection and we have used a systems-based approach to examine the host response in RSV-infected lung-derived macrophage cells. Results Lung macrophage cells could be efficiently infected (>95%) with RSV in vitro, and the expression of several virus structural proteins could be detected. Although we failed to detect significant levels of virus particle production, virus antigen could be detected up until 96 hours post-infection (hpi). Microarray analysis indicated that 20,086 annotated genes were expressed in the macrophage cells, and RSV infection induced an 8.9% and 11.3% change in the global gene transcriptome at 4 hpi and 24 hpi respectively. Genes showing up-regulated expression were more numerous and exhibited higher changes in expression compared to genes showing down-regulated expression. Based on gene ontology, genes with cytokine, antiviral, cell death, and signal transduction functions showed the highest increases in expression, while signalling transduction, RNA binding and protein kinase genes showed the greatest reduction in expression levels. Analysis of the global gene expression profile using pathway enrichment analysis confirmed that up-regulated expression of pathways related to pathogen recognition, interferon signalling and antigen presentation occurred in the lung macrophage cells challenged with RSV. Conclusion Our data provided a comprehensive analysis of RSV-induced gene expression changes in lung macrophages. Although virus gene expression was detected, our data was consistent with an abortive infection and this correlated with the activation of several antivirus signalling pathways such as interferon type I signalling and cell death signalling. RSV infection induced a relatively large increase in pro-inflammatory cytokine expression, however the maintenance of this pro-inflammatory response was not dependent on the production of infectious virus particles. The sustained pro-inflammatory response even in the absence of a productive infection suggests that drugs that control the pro-inflammatory response may be useful in the treatment of patients with severe RSV infection. PMID:23506210

An Effective Model of the Retinoic Acid Induced HL-60 Differentiation Program.

PubMed

Tasseff, Ryan; Jensen, Holly A; Congleton, Johanna; Dai, David; Rogers, Katharine V; Sagar, Adithya; Bunaciu, Rodica P; Yen, Andrew; Varner, Jeffrey D

2017-10-30

In this study, we present an effective model All-Trans Retinoic Acid (ATRA)-induced differentiation of HL-60 cells. The model describes reinforcing feedback between an ATRA-inducible signalsome complex involving many proteins including Vav1, a guanine nucleotide exchange factor, and the activation of the mitogen activated protein kinase (MAPK) cascade. We decomposed the effective model into three modules; a signal initiation module that sensed and transformed an ATRA signal into program activation signals; a signal integration module that controlled the expression of upstream transcription factors; and a phenotype module which encoded the expression of functional differentiation markers from the ATRA-inducible transcription factors. We identified an ensemble of effective model parameters using measurements taken from ATRA-induced HL-60 cells. Using these parameters, model analysis predicted that MAPK activation was bistable as a function of ATRA exposure. Conformational experiments supported ATRA-induced bistability. Additionally, the model captured intermediate and phenotypic gene expression data. Knockout analysis suggested Gfi-1 and PPARg were critical to the ATRAinduced differentiation program. These findings, combined with other literature evidence, suggested that reinforcing feedback is central to hyperactive signaling in a diversity of cell fate programs.

Ambient pH Controls Glycogen Levels by Regulating Glycogen Synthase Gene Expression in Neurospora crassa. New Insights into the pH Signaling Pathway

PubMed Central

Cupertino, Fernanda Barbosa; Freitas, Fernanda Zanolli; de Paula, Renato Magalhães; Bertolini, Maria Célia

2012-01-01

Glycogen is a polysaccharide widely distributed in microorganisms and animal cells and its metabolism is under intricate regulation. Its accumulation in a specific situation results from the balance between glycogen synthase and glycogen phosphorylase activities that control synthesis and degradation, respectively. These enzymes are highly regulated at transcriptional and post-translational levels. The existence of a DNA motif for the Aspergillus nidulans pH responsive transcription factor PacC in the promoter of the gene encoding glycogen synthase (gsn) in Neurospora crassa prompted us to investigate whether this transcription factor regulates glycogen accumulation. Transcription factors such as PacC in A. nidulans and Rim101p in Saccharomyces cerevisiae play a role in the signaling pathway that mediates adaptation to ambient pH by inducing the expression of alkaline genes and repressing acidic genes. We showed here that at pH 7.8 pacC was over-expressed and gsn was down-regulated in wild-type N. crassa coinciding with low glycogen accumulation. In the pacCKO strain the glycogen levels and gsn expression at alkaline pH were, respectively, similar to and higher than the wild-type strain at normal pH (5.8). These results characterize gsn as an acidic gene and suggest a regulatory role for PACC in gsn expression. The truncated recombinant protein, containing the DNA-binding domain specifically bound to a gsn DNA fragment containing the PacC motif. DNA-protein complexes were observed with extracts from cells grown at normal and alkaline pH and confirmed by ChIP-PCR analysis. The PACC present in these extracts showed equal molecular mass, indicating that the protein is already processed at normal pH, in contrast to A. nidulans. Together, these results show that the pH signaling pathway controls glycogen accumulation by regulating gsn expression and suggest the existence of a different mechanism for PACC activation in N. crassa. PMID:22952943

Decreased PD-1 expression on circulating CD4+T cell and PD-L1 expression on myeloid dendritic cell correlate with clinical manifestations in systemic juvenile idiopathic arthritis.

PubMed

Cai, Li; Zhang, Chenxing; Wu, Jing; Zhou, Wei; Chen, Tongxin

2018-03-30

Programmed cell death-1 (PD-1) and its ligand (PD-L1) mediate negative signal in autoimmune diseases. While little is known about its role in juvenile idiopathic arthritis (JIA). The study aimed to reveal the circulating cell profile and the relative PD-1/PD-L1 expression of JIA subsets, elucidating their underlying immunomodulatory mechanisms. We detected the circulating cells and the relative PD-1/PD-L1 signaling in 101 JIA patients and 50 controls by flow cytometry and analyzed their association with disease activity and clinical manifestations. Different from other JIA types, active systemic JIA (sJIA) patients had lower percentage and count of CD4 + T cells and lower PD-1 expression on them compared with healthy controls (P<0.05), active polyarthritis (P<0.05) and enthesitis-related arthritis (ERA) patients (P<0.05). Also, they had higher percentage and count of myeloid dendritic cell (mDC) and lower PD-L1 expression on mDC compared with healthy controls (P<0.05). Both PD-1 on CD4 + T cell and PD-L1 on mDC were negatively correlated with JADAS-27 in sJIA patients (P<0.05). In addition, PD-1 expression on CD4 + T cell was negatively associated with the number of involved joints (P<0.05) and PD-L1 on mDC was lower in patients with fever (P<0.01), which could further divide patients into two groups of different manifestations. Our finding displayed decreased CD4 + T cell, increased mDC and reduced PD-1/PD-L1 signal in sJIA PBMC comparing with other JIA subsets, which might be helpful in JIA differential diagnosis and responsible for distinct clinical manifestations via different mechanisms. Copyright © 2018 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

[Effect of ERK1/2 Signaling Pathway Inhibitor PD98059 on the Expression of Ras, BRaf, MEK, ERK1/2 in Marrow Nucleated Red Blood Cells of CMS Patients].

PubMed

Han, Yuan-Fang; Ji, Lin-Hua; Feng, Ting-Ting; Liu, Fang; Cui, Sen; Su, Juan

2017-10-01

To investigate the effect of ERK1 / 2 signaling pathway inhibitor PD98059 on Ras, Raf, MEK, ERK1, ERK2 expression in order to explore a new way for basic research and clinical treatment of the chronic mountain sickness(CMS). Sixteen CMS patients were selected, the bone marrow was collected for isolation of monomuclear cells (MNC), the cells were sorted by using CD71 and CD235a antibody magnetic beads, then positive cells were diveded into 5 groups: blank control, DMSO and PD98059 5, 10 and 20 µmol/L, and were cultured in hypoxid condition for 72 hours. The Ras-GTP levels in supernatant was detected by ELISA, the RT-PCR was used to determine the expression of BRaf, MEK, ERK1, ERK2 mRNA in nucleated red blood cells, and the Western blot method was used to detect expression of BRaf, MEK, ERK1, ERK2 protein. PD98059 had no effect on the level of Ras-GTP in each groups. Compared with the blank control group, the expression levels of BRaf, MEK mRNA in DMSO group were not statistically significant (P values were 0.826, 0.298). Compared with the PD98059 20 mol/L group, the expression level of ERK1/2 mRNA was statistically significant (P=0.001, 0.002). Compared with the blank control group, expression levels of p-BRaf, p-MEK protein in DMSO group were not statistically significant (P=0.370, 0.351). Compared with the PD98059 20 mol/L group, the difference of p-ERK1/2 protein level in other 4 groups were statistically significant (P values were <0.001, 0.007). PD98059 can up-regulate the expressions of ERK1/2 miRNA and p-ERK1/2 protein in bone marrow nucleated red blood cells, the Ras / Raf / MEK / ERK 1/2 pathway is the main signal transduction pathway in regulating bone marrow nucleated red blood cells, suggesting that Ras/Raf /MEK /ERK 1/2 pathway may be involved in the pathogenesis of chronic mountain sickness process.

The Intersection of the Extrinsic Hedgehog and WNT/Wingless Signals with the Intrinsic Hox Code Underpins Branching Pattern and Tube Shape Diversity in the Drosophila Airways

PubMed Central

Matsuda, Ryo; Hosono, Chie; Saigo, Kaoru; Samakovlis, Christos

2015-01-01

The tubular networks of the Drosophila respiratory system and our vasculature show distinct branching patterns and tube shapes in different body regions. These local variations are crucial for organ function and organismal fitness. Organotypic patterns and tube geometries in branched networks are typically controlled by variations of extrinsic signaling but the impact of intrinsic factors on branch patterns and shapes is not well explored. Here, we show that the intersection of extrinsic hedgehog(hh) and WNT/wingless (wg) signaling with the tube-intrinsic Hox code of distinct segments specifies the tube pattern and shape of the Drosophila airways. In the cephalic part of the airways, hh signaling induces expression of the transcription factor (TF) knirps (kni) in the anterior dorsal trunk (DTa1). kni represses the expression of another TF spalt major (salm), making DTa1 a narrow and long tube. In DTa branches of more posterior metameres, Bithorax Complex (BX-C) Hox genes autonomously divert hh signaling from inducing kni, thereby allowing DTa branches to develop as salm-dependent thick and short tubes. Moreover, the differential expression of BX-C genes is partly responsible for the anterior-to-posterior gradual increase of the DT tube diameter through regulating the expression level of Salm, a transcriptional target of WNT/wg signaling. Thus, our results highlight how tube intrinsic differential competence can diversify tube morphology without changing availabilities of extrinsic factors. PMID:25615601

Control of asgE Expression during Growth and Development of Myxococcus xanthus

PubMed Central

Garza, Anthony G.; Harris, Baruch Z.; Greenberg, Brandon M.; Singer, Mitchell

2000-01-01

One of the earliest events in the Myxococcus xanthus developmental cycle is production of an extracellular cell density signal called A-signal (or A-factor). Previously, we showed that cells carrying an insertion in the asgE gene fail to produce normal levels of this cell-cell signal. In this study we found that expression of asgE is growth phase regulated and developmentally regulated. Several lines of evidence indicate that asgE is cotranscribed with an upstream gene during development. Using primer extension analyses, we identified two 5′ ends for this developmental transcript. The DNA sequence upstream of one 5′ end has similarity to the promoter regions of several genes that are A-signal dependent, whereas sequences located upstream of the second 5′ end show similarity to promoter elements identified for genes that are C-signal dependent. Consistent with this result is our finding that mutants failing to produce A-signal or C-signal are defective for developmental expression of asgE. In contrast to developing cells, the large majority of the asgE transcript found in vegetative cells appears to be monocistronic. This finding suggests that asgE uses different promoters for expression during vegetative growth and development. Growth phase regulation of asgE is abolished in a relA mutant, indicating that this vegetative promoter is induced by starvation. The data presented here, in combination with our previous results, indicate that the level of AsgE in vegetative cells is sufficient for this protein to carry out its function during development. PMID:11073904

Death receptor 3 signaling enhances proliferation of human regulatory T cells.

PubMed

Bittner, Sebastian; Knoll, Gertrud; Ehrenschwender, Martin

2017-04-01

Exploiting regulatory T cells (Tregs) to control aberrant immune reactions is a promising therapeutic approach, but is hampered by their relative paucity. In mice, activation of death receptor 3 (DR3), a member of the TNF-receptor superfamily (TNFRSF), increases Treg frequency and efficiently controls exuberant immune activation. For human Tregs, neither DR3 expression nor potential functions have been described. Here, we show that human Tregs express DR3 and demonstrate DR3-mediated activation of p38, ERK, and NFκB. DR3 stimulation enhances Treg expansion ex vivo while retaining their suppressive capacity. In summary, our results establish a functional role for DR3 signaling in human Tregs and could potentially help to tailor Treg-based therapies. © 2017 Federation of European Biochemical Societies.

Identification of mechanosensitive genes during skeletal development: alteration of genes associated with cytoskeletal rearrangement and cell signalling pathways.

PubMed

Rolfe, Rebecca A; Nowlan, Niamh C; Kenny, Elaine M; Cormican, Paul; Morris, Derek W; Prendergast, Patrick J; Kelly, Daniel; Murphy, Paula

2014-01-20

Mechanical stimulation is necessary for regulating correct formation of the skeleton. Here we test the hypothesis that mechanical stimulation of the embryonic skeletal system impacts expression levels of genes implicated in developmentally important signalling pathways in a genome wide approach. We use a mutant mouse model with altered mechanical stimulation due to the absence of limb skeletal muscle (Splotch-delayed) where muscle-less embryos show specific defects in skeletal elements including delayed ossification, changes in the size and shape of cartilage rudiments and joint fusion. We used Microarray and RNA sequencing analysis tools to identify differentially expressed genes between muscle-less and control embryonic (TS23) humerus tissue. We found that 680 independent genes were down-regulated and 452 genes up-regulated in humeri from muscle-less Spd embryos compared to littermate controls (at least 2-fold; corrected p-value ≤0.05). We analysed the resulting differentially expressed gene sets using Gene Ontology annotations to identify significant enrichment of genes associated with particular biological processes, showing that removal of mechanical stimuli from muscle contractions affected genes associated with development and differentiation, cytoskeletal architecture and cell signalling. Among cell signalling pathways, the most strongly disturbed was Wnt signalling, with 34 genes including 19 pathway target genes affected. Spatial gene expression analysis showed that both a Wnt ligand encoding gene (Wnt4) and a pathway antagonist (Sfrp2) are up-regulated specifically in the developing joint line, while the expression of a Wnt target gene, Cd44, is no longer detectable in muscle-less embryos. The identification of 84 genes associated with the cytoskeleton that are down-regulated in the absence of muscle indicates a number of candidate genes that are both mechanoresponsive and potentially involved in mechanotransduction, converting a mechanical stimulus into a transcriptional response. This work identifies key developmental regulatory genes impacted by altered mechanical stimulation, sheds light on the molecular mechanisms that interpret mechanical stimulation during skeletal development and provides valuable resources for further investigation of the mechanistic basis of mechanoregulation. In particular it highlights the Wnt signalling pathway as a potential point of integration of mechanical and molecular signalling and cytoskeletal components as mediators of the response.

Identification of mechanosensitive genes during skeletal development: alteration of genes associated with cytoskeletal rearrangement and cell signalling pathways

PubMed Central

2014-01-01

Background Mechanical stimulation is necessary for regulating correct formation of the skeleton. Here we test the hypothesis that mechanical stimulation of the embryonic skeletal system impacts expression levels of genes implicated in developmentally important signalling pathways in a genome wide approach. We use a mutant mouse model with altered mechanical stimulation due to the absence of limb skeletal muscle (Splotch-delayed) where muscle-less embryos show specific defects in skeletal elements including delayed ossification, changes in the size and shape of cartilage rudiments and joint fusion. We used Microarray and RNA sequencing analysis tools to identify differentially expressed genes between muscle-less and control embryonic (TS23) humerus tissue. Results We found that 680 independent genes were down-regulated and 452 genes up-regulated in humeri from muscle-less Spd embryos compared to littermate controls (at least 2-fold; corrected p-value ≤0.05). We analysed the resulting differentially expressed gene sets using Gene Ontology annotations to identify significant enrichment of genes associated with particular biological processes, showing that removal of mechanical stimuli from muscle contractions affected genes associated with development and differentiation, cytoskeletal architecture and cell signalling. Among cell signalling pathways, the most strongly disturbed was Wnt signalling, with 34 genes including 19 pathway target genes affected. Spatial gene expression analysis showed that both a Wnt ligand encoding gene (Wnt4) and a pathway antagonist (Sfrp2) are up-regulated specifically in the developing joint line, while the expression of a Wnt target gene, Cd44, is no longer detectable in muscle-less embryos. The identification of 84 genes associated with the cytoskeleton that are down-regulated in the absence of muscle indicates a number of candidate genes that are both mechanoresponsive and potentially involved in mechanotransduction, converting a mechanical stimulus into a transcriptional response. Conclusions This work identifies key developmental regulatory genes impacted by altered mechanical stimulation, sheds light on the molecular mechanisms that interpret mechanical stimulation during skeletal development and provides valuable resources for further investigation of the mechanistic basis of mechanoregulation. In particular it highlights the Wnt signalling pathway as a potential point of integration of mechanical and molecular signalling and cytoskeletal components as mediators of the response. PMID:24443808

CsPLDalpha1 and CsPLDgamma1 are differentially induced during leaf and fruit abscission and diurnally regulated in Citrus sinensis.

PubMed

Malladi, Anish; Burns, Jacqueline K

2008-01-01

Understanding leaf and fruit abscission is essential in order to develop strategies for controlling the process in fruit crops. Mechanisms involved in signalling leaf and fruit abscission upon induction by abscission agents were investigated in Citrus sinensis cv. 'Valencia'. Previous studies have suggested a role for phospholipid signalling; hence, two phospholipase D cDNA sequences, CsPLDalpha1 and CsPLDgamma1, were isolated and their role was examined. CsPLDalpha1 expression was reduced in leaves but unaltered in fruit peel tissue treated with an ethylene-releasing compound (ethephon), or a fruit-specific abscission agent, 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMNP). By contrast, CsPLDgamma1 expression was up-regulated within 6 h (leaves) and 24 h (fruit peel) after treatment with ethephon or CMNP, respectively. CsPLDalpha1 expression was diurnally regulated in leaf blade but not fruit peel. CsPLDgamma1 exhibited strong diurnal oscillation in expression in leaves and fruit peel with peak expression around midday. While diurnal fluctuation in CsPLDalpha1 expression appeared to be light-entrained in leaves, CsPLDgamma1 expression was regulated by light and the circadian clock. The diurnal expression of both genes was modulated by ethylene-signalling. The ethephon-induced leaf abscission and the ethephon- and CMNP-induced decrease in fruit detachment force were enhanced by application during rising diurnal expression of CsPLDgamma1. The results indicate differential regulation of CsPLDalpha1 and CsPLDgamma1 in leaves and fruit, and suggest possible roles for PLD-dependent signalling in regulating abscission responses in citrus.

TGF-β induction of FGF-2 expression in stromal cells requires integrated smad3 and MAPK pathways.

PubMed

Strand, Douglas W; Liang, Yao-Yun; Yang, Feng; Barron, David A; Ressler, Steven J; Schauer, Isaiah G; Feng, Xin-Hua; Rowley, David R

2014-01-01

Transforming Growth Factor-β (TGF-β) regulates the reactive stroma microenvironment associated with most carcinomas and mediates expression of many stromal derived factors important for tumor progression, including FGF-2 and CTGF. TGF-β is over-expressed in most carcinomas, and FGF-2 action is important in tumor-induced angiogenesis. The signaling mechanisms of how TGF-β regulates FGF-2 expression in the reactive stroma microenvironment are not understood. Accordingly, we have assessed key signaling pathways that mediate TGF-β1-induced FGF-2 expression in prostate stromal fibroblasts and mouse embryo fibroblasts (MEFs) null for Smad2 and Smad3. TGF-β1 induced phosphorylation of Smad2, Smad3, p38 and ERK1/2 proteins in both control MEFs and prostate fibroblasts. Of these, Smad3, but not Smad2 was found to be required for TGF-β1 induction of FGF-2 expression in stromal cells. ChIP analysis revealed a Smad3/Smad4 complex was associated with the -1.9 to -2.3 kb upstream proximal promoter of the FGF-2 gene, further suggesting a Smad3-specific regulation. In addition, chemical inhibition of p38 or ERK1/2 MAPK activity also blocked TGF-β1-induced FGF-2 expression in a Smad3-independent manner. Conversely, inhibition of JNK signaling enhanced FGF-2 expression. Together, these data indicate that expression of FGF-2 in fibroblasts in the tumor stromal cell microenvironment is coordinately dependent on both intact Smad3 and MAP kinase signaling pathways. These pathways and key downstream mediators of TGF-β action in the tumor reactive stroma microenvironment, may evolve as putative targets for therapeutic intervention.

CsPLDα1 and CsPLDγ1 are differentially induced during leaf and fruit abscission and diurnally regulated in Citrus sinensis

PubMed Central

Malladi, Anish; Burns, Jacqueline K.

2008-01-01

Understanding leaf and fruit abscission is essential in order to develop strategies for controlling the process in fruit crops. Mechanisms involved in signalling leaf and fruit abscission upon induction by abscission agents were investigated in Citrus sinensis cv. ‘Valencia’. Previous studies have suggested a role for phospholipid signalling; hence, two phospholipase D cDNA sequences, CsPLDα1 and CsPLDγ1, were isolated and their role was examined. CsPLDα1 expression was reduced in leaves but unaltered in fruit peel tissue treated with an ethylene-releasing compound (ethephon), or a fruit-specific abscission agent, 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMNP). By contrast, CsPLDγ1 expression was up-regulated within 6 h (leaves) and 24 h (fruit peel) after treatment with ethephon or CMNP, respectively. CsPLDα1 expression was diurnally regulated in leaf blade but not fruit peel. CsPLDγ1 exhibited strong diurnal oscillation in expression in leaves and fruit peel with peak expression around midday. While diurnal fluctuation in CsPLDα1 expression appeared to be light-entrained in leaves, CsPLDγ1 expression was regulated by light and the circadian clock. The diurnal expression of both genes was modulated by ethylene-signalling. The ethephon-induced leaf abscission and the ethephon- and CMNP-induced decrease in fruit detachment force were enhanced by application during rising diurnal expression of CsPLDγ1. The results indicate differential regulation of CsPLDα1 and CsPLDγ1 in leaves and fruit, and suggest possible roles for PLD-dependent signalling in regulating abscission responses in citrus. PMID:18799715

A distinct regulatory region of the Bmp5 locus activates gene expression following adult bone fracture or soft tissue injury.

PubMed

Guenther, Catherine A; Wang, Zhen; Li, Emma; Tran, Misha C; Logan, Catriona Y; Nusse, Roel; Pantalena-Filho, Luiz; Yang, George P; Kingsley, David M

2015-08-01

Bone morphogenetic proteins (BMPs) are key signaling molecules required for normal development of bones and other tissues. Previous studies have shown that null mutations in the mouse Bmp5 gene alter the size, shape and number of multiple bone and cartilage structures during development. Bmp5 mutations also delay healing of rib fractures in adult mutants, suggesting that the same signals used to pattern embryonic bone and cartilage are also reused during skeletal regeneration and repair. Despite intense interest in BMPs as agents for stimulating bone formation in clinical applications, little is known about the regulatory elements that control developmental or injury-induced BMP expression. To compare the DNA sequences that activate gene expression during embryonic bone formation and following acute injuries in adult animals, we assayed regions surrounding the Bmp5 gene for their ability to stimulate lacZ reporter gene expression in transgenic mice. Multiple genomic fragments, distributed across the Bmp5 locus, collectively coordinate expression in discrete anatomic domains during normal development, including in embryonic ribs. In contrast, a distinct regulatory region activated expression following rib fracture in adult animals. The same injury control region triggered gene expression in mesenchymal cells following tibia fracture, in migrating keratinocytes following dorsal skin wounding, and in regenerating epithelial cells following lung injury. The Bmp5 gene thus contains an "injury response" control region that is distinct from embryonic enhancers, and that is activated by multiple types of injury in adult animals. Copyright © 2015 Elsevier Inc. All rights reserved.

Loss of neurotrophin-3 from smooth muscle disrupts vagal gastrointestinal afferent signaling and satiation

PubMed Central

Biddinger, Jessica E.; Baquet, Zachary C.; Jones, Kevin R.; McAdams, Jennifer

2013-01-01

A large proportion of vagal afferents are dependent on neurotrophin-3 (NT-3) for survival. NT-3 is expressed in developing gastrointestinal (GI) smooth muscle, a tissue densely innervated by vagal mechanoreceptors, and thus could regulate their survival. We genetically ablated NT-3 from developing GI smooth muscle and examined the pattern of loss of NT-3 expression in the GI tract and whether this loss altered vagal afferent signaling or feeding behavior. Meal-induced c-Fos activation was reduced in the solitary tract nucleus and area postrema in mice with a smooth muscle-specific NT-3 knockout (SM-NT-3KO) compared with controls, suggesting a decrease in vagal afferent signaling. Daily food intake and body weight of SM-NT-3KO mice and controls were similar. Meal pattern analysis revealed that mutants, however, had increases in average and total daily meal duration compared with controls. Mutants maintained normal meal size by decreasing eating rate compared with controls. Although microstructural analysis did not reveal a decrease in the rate of decay of eating in SM-NT-3KO mice, they ate continuously during the 30-min meal, whereas controls terminated feeding after 22 min. This led to a 74% increase in first daily meal size of SM-NT-3KO mice compared with controls. The increases in meal duration and first meal size of SM-NT-3KO mice are consistent with reduced satiation signaling by vagal afferents. This is the first demonstration of a role for GI NT-3 in short-term controls of feeding, most likely involving effects on development of vagal GI afferents that regulate satiation. PMID:24068045

BRCA1-IRIS regulates cyclin D1 expression in breast cancer cells

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

Nakuci, Enkeleda; Mahner, Sven; DiRenzo, James

2006-10-01

The regulator of cell cycle progression, cyclin D1, is up-regulated in breast cancer cells; its expression is, in part, dependent on ER{alpha} signaling. However, many ER{alpha}-negative tumors and tumor cell lines (e.g., SKBR3) also show over-expression of cyclin D1. This suggests that, in addition to ER{alpha} signaling, cyclin D1 expression is under the control of other signaling pathways; these pathways may even be over-expressed in the ER{alpha}-negative cells. We previously noticed that both ER{alpha}-positive and -negative cell lines over-express BRCA1-IRIS mRNA and protein. Furthermore, the level of over-expression of BRCA1-IRIS in ER{alpha}-negative cell lines even exceeded its over-expression level inmore » ER{alpha}-positive cell lines. In this study, we show that: (1) BRCA1-IRIS forms complex with two of the nuclear receptor co-activators, namely, SRC1 and SRC3 (AIB1) in an ER{alpha}-independent manner. (2) BRCA1-IRIS alone, or in connection with co-activators, is recruited to the cyclin D1 promoter through its binding to c-Jun/AP1 complex; this binding activates the cyclin D1 expression. (3) Over-expression of BRCA1-IRIS in breast cells over-activates JNK/c-Jun; this leads to the induction of cyclin D1 expression and cellular proliferation. (4) BRCA1-IRIS activation of JNK/c-Jun/AP1 appears to account for this, because in cells that were depleted from BRCA1-IRIS, JNK remained inactive. However, depletion of SRC1 or SRC3 instead reduced c-Jun expression. Our data suggest that this novel signaling pathway links BRCA1-IRIS to cellular proliferation through c-Jun/AP1 nuclear pathway; finally, this culminates in the increased expression of the cyclin D1 gene.« less

Interaction between hormonal and mitochondrial signalling during growth, development and in plant defence responses.

PubMed

Berkowitz, Oliver; De Clercq, Inge; Van Breusegem, Frank; Whelan, James

2016-05-01

Mitochondria play a central role in plant metabolism as they are a major source of ATP through synthesis by the oxidative phosphorylation pathway and harbour key metabolic reactions such as the TCA cycle. The energy and building blocks produced by mitochondria are essential to drive plant growth and development as well as to provide fuel for responses to abiotic and biotic stresses. The majority of mitochondrial proteins are encoded in the nuclear genome and have to be imported into the organelle. For the regulation of the corresponding genes intricate signalling pathways exist to adjust their expression. Signals directly regulate nuclear gene expression (anterograde signalling) to adjust the protein composition of the mitochondria to the needs of the cell. In parallel, mitochondria communicate back their functional status to the nucleus (retrograde signalling) to prompt transcriptional regulation of responsive genes via largely unknown signalling mechanisms. Plant hormones are the major signalling components regulating all layers of plant development and cellular functions. Increasing evidence is now becoming available that plant hormones are also part of signalling networks controlling mitochondrial function and their biogenesis. This review summarizes recent advances in understanding the interaction of mitochondrial and hormonal signalling pathways. © 2016 John Wiley & Sons Ltd.

Down-regulation of Wt1 activates Wnt/β-catenin signaling through modulating endocytic route of LRP6 in podocyte dysfunction in vitro.

PubMed

Jing, Zhou; Wei-jie, Yuan; Yi-Feng, Zhu-ge

2015-09-01

Podocyte dysfunction plays important roles in the pathogenesis of chronic kidney disease, and Wt1 has long been considered to be a marker of podocyte, whereas its roles and mechanisms in podocyte injury are still unclear though Wt1 mutations are reported to be involved in the development of glomerular disease in human and mice. Here we show that down-regulation of Wt1 could induce podocyte dysfunction and apoptosis through activating Wnt/β-catenin signaling. Podocytes treated with adriamycin demonstrated decreased expression of Wt1, coupled with activated Wnt/β-catenin signaling in vitro. Reduced expression of Wt1 in podocytes transfected with Wt1 siRNA is correlated with activated Wnt/β-catenin signaling, increased podocyte apoptosis, as well as suppressed expression of nephrin. Blockade of Wnt/β-catenin signaling with Dickkopf-1 ameliorated podocyte injury and apoptosis induced by Wt1 siRNA. We also found that membrane LRP6 was increased dramatically in podocytes transfected with Wt1 siRNA compared with control siRNA, while no significant change was found in total LRP6. Caveolin- and clathrin-dependent endocytosis were both involved in the regulation of β-catenin signaling. And we found that down-regulation of Wt1 in podocytes mediates activation of Wnt/β-catenin signaling by recruiting LRP6 to the caveolin-mediated endocytosis route, thereby sequestering it from clathrin-dependent endocytosis. As a result, we concluded that Wt1 expression levels in podocytes regulate Wnt/β-catenin signaling through modulating the endocytic fate of LRP6, and this indicates a potential target for the therapy of CKD. Copyright © 2015 Elsevier Inc. All rights reserved.

[CD22 signal abnormalities in the pathogenesis of immune related pancytopenia].

PubMed

Wu, Xiaojing; Shao, Zonghong; Ruan, Erbao; Fu, Rong; Wang, Guojin; Liu, Hong; Wu, Yuhong; Song, Jia; Xing, Limin; Qu, Wen; Cuan, Jing; Li, Lijuan; Wang, Xiaoming; Liu, Hui; Wang, Yihao; Wang, Huaquan

2015-07-14

To investigate the expression of CD22 and its downstream signal molecule spleen tyrosine kinase (SYK) and their phosphorylation of B lymphocytes in patients with immune related pancytopenia(IRP), and to explore the role of CD22 in pathogenesis of IRP. The expression of CD22, SYK and their phosphorylation, along with the expression of IgG and IgM, which obtained from B lymphocytes in peripheral blood of 46 patients with IRP(22 new diagnosed and 24 remitted patients returned to normal after treatment), 22 healthy controls and 12 chronic lymphocytic leukemia(CLL) patients from February to December 2014 were analyzed by flow cytometry. And the mRNA expression of CD22 in peripheral blood mononuclear cell was determined by real-time quantitative PCR. The ratios of CD22+ cells and phosphorylated CD22(pCD22)+ cells of B lymphocytes in new diagnosed group (60. 03% ± 20. 94% 71. 32% ± 11. 16%) were significantly higher than those in remission group (46. 92% ± 20. 04%, 55. 82% ± 14. 42%), normal control group (46. 86% ± 17. 78%, 53. 28% ± 14. 76%) and CLL group (39. 74% ± 18. 96%, 59. 07% ± 17.09%) (all P <0.05). The ratios of phosphorylated SYK( pSYK) + cells in the four groups had the same trend (all P <0. 05). The ratio of pCD22+ cells/pSYK+ cells in new diagnosed group was significantly lower than that in normal control group and CLL group (27. 39 (5. 06 - 102. 70) vs 55. 95 (15. 25 - 298. 53), 56. 92(5. 60 - 228. 96), both P <0. 05), and pCD22+ cells positively correlated to pSYK+ cells ( r = 0. 341, P < 0. 05). The expression of IgG in new diagnosed group and remission group was significantly higher than that in normal control group, and the expression of IgM in new diagnosed group was significantly higher than that in normal control group and CLL group (all P <0. 05). The expression levels of CD22 mRNA in new diagnosed group was significantly higher than that in remission group, normal control group and CLL group (all P <0. 05). The BCR signal pathway of B lymphocyte in IRP patients is enhanced, and the quantity and function of CD22 are increased, while which are still insufficient to inhibit B cell proliferation, and these may have some relationships with the pathogenesis of IRP. [Key words] Pancytopenia; Antigens, CD22; Immune related pancytopenia; Spleen tyrosine kinase; Phosphorylation

C/EBPβ and Nuclear Factor of Activated T Cells Differentially Regulate Adamts-1 Induction by Stimuli Associated with Vascular Remodeling

PubMed Central

Oller, Jorge; Alfranca, Arántzazu; Méndez-Barbero, Nerea; Villahoz, Silvia; Lozano-Vidal, Noelia; Martín-Alonso, Mara; Arroyo, Alicia G.; Escolano, Amelia; Armesilla, Angel Luis

2015-01-01

Emerging evidence indicates that the metalloproteinase Adamts-1 plays a significant role in the pathophysiology of vessel remodeling, but little is known about the signaling pathways that control Adamts-1 expression. We show that vascular endothelial growth factor (VEGF), angiotensin-II, interleukin-1β, and tumor necrosis factor α, stimuli implicated in pathological vascular remodeling, increase Adamts-1 expression in endothelial and vascular smooth muscle cells. Analysis of the intracellular signaling pathways implicated in this process revealed that VEGF and angiotensin-II upregulate Adamts-1 expression via activation of differential signaling pathways that ultimately promote functional binding of the NFAT or C/EBPβ transcription factors, respectively, to the Adamts-1 promoter. Infusion of mice with angiotensin-II triggered phosphorylation and nuclear translocation of C/EBPβ proteins in aortic cells concomitantly with an increase in the expression of Adamts-1, further underscoring the importance of C/EBPβ signaling in angiotensin-II-induced upregulation of Adamts-1. Similarly, VEGF promoted NFAT activation and subsequent Adamts-1 induction in aortic wall in a calcineurin-dependent manner. Our results demonstrate that Adamts-1 upregulation by inducers of pathological vascular remodeling is mediated by specific signal transduction pathways involving NFAT or C/EBPβ transcription factors. Targeting of these pathways may prove useful in the treatment of vascular disease. PMID:26217013

MarvelD3 regulates the c-Jun N-terminal kinase pathway during eye development in Xenopus

PubMed Central

Vacca, Barbara; Sanchez-Heras, Elena; Steed, Emily; Balda, Maria S.; Ohnuma, Shin-Ichi; Sasai, Noriaki; Mayor, Roberto

2016-01-01

ABSTRACT Ocular morphogenesis requires several signalling pathways controlling the expression of transcription factors and cell-cycle regulators. However, despite a well-known mechanism, the dialogue between those signals and factors remains to be unveiled. Here, we identify a requirement for MarvelD3, a tight junction transmembrane protein, in eye morphogenesis in Xenopus. MarvelD3 depletion led to an abnormally pigmented eye or even an eye-less phenotype, which was rescued by ectopic MarvelD3 expression. Altering MarvelD3 expression led to deregulated expression of cell-cycle regulators and transcription factors required for eye development. The eye phenotype was rescued by increased c-Jun terminal Kinase activation. Thus, MarvelD3 links tight junctions and modulation of the JNK pathway to eye morphogenesis. PMID:27870636

Progesterone-dependent Regulation of Endometrial Cannabinoid Receptor Type 1 (CB1-R) Expression is Disrupted in Women with Endometriosis and in Isolated Stromal Cells Exposed to TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin)

PubMed Central

Resuehr, David; Glore, Dana R.; Taylor, Hugh S.; Bruner-Tran, Kaylon L.; Osteen, Kevin G.

2012-01-01

Objective To examine the differentiation-related expression of CB1-R mRNA and protein in endometrial tissue obtained from women with and without endometriosis and to determine the impact of acute TCDD exposure on CB1-R gene expression in isolated endometrial stromal cells. Design Laboratory-based study Setting University-affiliated medical center Patients Women with and without endometriosis undergoing volunteer endometrial biopsies after informed consent. Interventions None Main Outcome Measures Analysis of in vivo CB1-R mRNA and protein expression in human endometrial tissues and mRNA expression in isolated stromal cells following exposure to TCDD or a progesterone receptor antagonist (Onapristone). Results CB1-R mRNA and protein expression was highest during the progesterone-dominated secretory phase in control women, while expression was minimal in endometrial tissues acquired from women with endometriosis, regardless of the cycle phase. Although progesterone was found to induce CB1-R mRNA expression in endometrial stromal cells from control donors, steroid-induced expression of this gene was inhibited by co-treatment with either TCDD or Onapristone. Conclusions Our studies reveal a role for the anti-inflammatory actions of progesterone in regulating endometrial cannabinoid signaling, which is disrupted in women with endometriosis. Significantly, our studies demonstrate, for the first time, that acute TCDD exposure disrupts cannabinoid signaling in the human endometrium. PMID:22789143

The expression of Longus type 4 pilus of enterotoxigenic Escherichia coli is regulated by LngR and LngS and by H-NS, CpxR and CRP global regulators.

PubMed

De la Cruz, Miguel A; Ruiz-Tagle, Alejandro; Ares, Miguel A; Pacheco, Sabino; Yáñez, Jorge A; Cedillo, Lilia; Torres, Javier; Girón, Jorge A

2017-05-01

Enterotoxigenic Escherichia coli produces a long type 4 pilus called Longus. The regulatory elements and the environmental signals controlling the expression of Longus-encoding genes are unknown. We identified two genes lngR and lngS in the Longus operon, whose predicted products share homology with transcriptional regulators. Isogenic lngR and lngS mutants were considerably affected in transcription of lngA pilin gene. The expression of lngA, lngR and lngS genes was optimally expressed at 37°C at pH 7.5. The presence of glucose and sodium chloride had a positive effect on Longus expression. The presence of divalent ions, particularly calcium, appears to be an important stimulus for Longus production. In addition, we studied H-NS, CpxR and CRP global regulators, on Longus expression. The response regulator CpxR appears to function as a positive regulator of lng genes as the cpxR mutant showed reduced levels of lngRSA expression. In contrast, H-NS and CRP function as negative regulators since expression of lngA was up-regulated in isogenic hns and crp mutants. H-NS and CRP were required for salt- and glucose-mediated regulation of Longus. Our data suggest the existence of a complex regulatory network controlling Longus expression, involving both local and global regulators in response to different environmental signals. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

Ectopic application of recombinant BMP-2 and BMP-4 can change patterning of developing chick facial primordia.

PubMed

Barlow, A J; Francis-West, P H

1997-01-01

The facial primordia initially consist of buds of undifferentiated mesenchyme, which give rise to a variety of tissues including cartilage, muscle and nerve. These must be arranged in a precise spatial order for correct function. The signals that control facial outgrowth and patterning are largely unknown. The bone morphogenetic proteins Bmp-2 and Bmp-4 are expressed in discrete regions at the distal tips of the early facial primordia suggesting possible roles for BMP-2 and BMP-4 during chick facial development. We show that expression of Bmp-4 and Bmp-2 is correlated with the expression of Msx-1 and Msx-2 and that ectopic application of BMP-2 and BMP-4 can activate Msx-1 and Msx-2 gene expression in the developing facial primordia. We correlate this activation of gene expression with changes in skeletal development. For example, activation of Msx-1 gene expression across the distal tip of the mandibular primordium is associated with an extension of Fgf-4 expression in the epithelium and bifurcation of Meckel's cartilage. In the maxillary primordium, extension of the normal domain of Msx-1 gene expression is correlated with extended epithelial expression of shh and bifurcation of the palatine bone. We also show that application of BMP-2 can increase cell proliferation of the mandibular primordia. Our data suggest that BMP-2 and BMP-4 are part of a signalling cascade that controls outgrowth and patterning of the facial primordia.

[Controlling effect of bushen huatan compound on the insulin signal conducting molecule inside ovaries in polycystic ovary syndrome model rats].

PubMed

Liang, Chen; Cong, Jing; Chang, Hui

2011-12-01

To study the effects of Bushen Huatan Compound (BHC) on the glycolipid metabolism and the expressions of the insulin signal conducting molecules inside ovaries in polycystic ovary syndrome (PCOS) model rats. Female Wistar rats were subcutaneously injected with 2.5 mg/kg testosterone propionate (Their female offspring were randomly divided into the medication group and the model group, 10 in each.) or neutral tea oil of the same dose (Ten female offspring was taken as the control group.) on the 16th day of pregnancy, once daily, for 3 successive days. BHC was given to rats in the medication group by gastrogavage, while equal volume of distilled water was given to rats in the model group and the control group by gastrogavage, both once daily for 20 successive days. The body weight and ovary weight were weighed to calculate the ratio of wet fat weight/body weight. The blood glucose levels were detected at 0, 0.5, 1, and 2 h using oral glucose tolerance test (OGTT). The serum concentrations of high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), fasting blood glucose (FBG), and insulin were detected to calculate homeostasis model assessment of insulin resistance (HOMA-IR). The expressions of protein kinase B (AKT2), glycogen synthase kinase-3beta (GSK3beta), glucose transporter-4 (GLUT4), extracellular signal regulated kinase-1 (ERK1) protein, P-AKT2, P-GSK3beta, and P-ERK1 in ovaries were detected using Western blot. Compared with the control group, the ratio of wet fat weight/ body weight, the blood glucose levels at 0.5 and 2 h in OGTT, and HOMA-IR all obviously increased, and the HDL-C level obviously decreased in the model group (P < 0.05). Compared with the model group, the ratio of wet fat weight/body weight and the blood glucose levels at 2 h in OGTT obviously decreased, and the HDL-C level obviously increased in the medication group (P < 0.05). The expressions of AKT2, P-AKT2, GSK3beta, P-GSK3beta, GLUT4, and ERK1 in the ovary tissue were obviously lower in the model group than in the control group (P < 0.05). The expressions of GSK3beta, P-GSK3beta, and GLUT4 were more obviously enhanced in the medication group than in the model group (P < 0.05). Insulin resistance and glucolipid metabolism dysfunction existed in female PCOS rats. Besides, abnormal insulin signaling pathway existed in the ovary tissue. BHC could remarkably ameliorate the IR degree and glucolipid metabolism functions, and might be correlated with regulating the protein expressions of insulin signal conducting molecules.

Somato-Dendritic Localization and Signaling by Leptin Receptors in Hypothalamic POMC and AgRP Neurons

PubMed Central

Ha, Sangdeuk; Baver, Scott; Huo, Lihong; Gata, Adriana; Hairston, Joyce; Huntoon, Nicholas; Li, Wenjing; Zhang, Thompson; Benecchi, Elizabeth J.; Ericsson, Maria; Hentges, Shane T.; Bjørbæk, Christian

2013-01-01

Leptin acts via neuronal leptin receptors to control energy balance. Hypothalamic pro-opiomelanocortin (POMC) and agouti-related peptide (AgRP)/Neuropeptide Y (NPY)/GABA neurons produce anorexigenic and orexigenic neuropeptides and neurotransmitters, and express the long signaling form of the leptin receptor (LepRb). Despite progress in the understanding of LepRb signaling and function, the sub-cellular localization of LepRb in target neurons has not been determined, primarily due to lack of sensitive anti-LepRb antibodies. Here we applied light microscopy (LM), confocal-laser scanning microscopy (CLSM), and electron microscopy (EM) to investigate LepRb localization and signaling in mice expressing a HA-tagged LepRb selectively in POMC or AgRP/NPY/GABA neurons. We report that LepRb receptors exhibit a somato-dendritic expression pattern. We further show that LepRb activates STAT3 phosphorylation in neuronal fibers within several hypothalamic and hindbrain nuclei of wild-type mice and rats, and specifically in dendrites of arcuate POMC and AgRP/NPY/GABA neurons of Leprb +/+ mice and in Leprb db/db mice expressing HA-LepRb in a neuron specific manner. We did not find evidence of LepRb localization or STAT3-signaling in axon-fibers or nerve-terminals of POMC and AgRP/NPY/GABA neurons. Three-dimensional serial EM-reconstruction of dendritic segments from POMC and AgRP/NPY/GABA neurons indicates a high density of shaft synapses. In addition, we found that the leptin activates STAT3 signaling in proximity to synapses on POMC and AgRP/NPY/GABA dendritic shafts. Taken together, these data suggest that the signaling-form of the leptin receptor exhibits a somato-dendritic expression pattern in POMC and AgRP/NPY/GABA neurons. Dendritic LepRb signaling may therefore play an important role in leptin’s central effects on energy balance, possibly through modulation of synaptic activity via post-synaptic mechanisms. PMID:24204898

[Effect of Shugan Jianpi Recipe on LXRα/FAS signaling pathway mediated hepatocyte fatty deposits in NAFLD rats].

PubMed

Gong, Xiang-Wen; Yang-Qin-He; Yan, Hai-Zhen; Zhang, Yu-Pei; Huang, Jin; Xu, Yong-Jian; Zhang, Jin-Wen; Lin, Chun-Mei

2014-12-01

To explore the effect of Shugan Jianpi Recipe (SJR) on LXRα/FAS signaling pathway mediated hepatocyte fatty deposits in nonalcoholic fatty liver disease (NAFLD) rats. Totally 75 SPF grade male SD rats were randomly divided into 5 groups, i.e., the normal control group, the model group, the Shugan Recipe (SR) treatment groups, the Jianpi Recipe (JR) treatment group, and the SJR group. Except rats in the normal control group, the NAFLD rat model was duplicated using high fat diet (HFD). SR (Chaihu Shugan Powder) was administered to rats in the SR group. JR (Shenlin Baizhu Powder) was administered to rats in the JR group. SJR (Chaihu Shugan Powder plus Shenlin Baizhu Powder) was administered to rats in the SJR group. Changes of liver fat were analyzed using automatic biochemical analyzer. Liver cells were separated by low-speed centrifugation. Their activities and purities were identify using Typan blue and flow cytometry (FCM). Expression levels of LXRα and FAS mRNA in hepatocytes detected by Real-time quantitative PCR. Expression levels of LXRα and FAS protein were detected by Western blot. (1) Pathological results showed in the model group, hepatocytes were swollen with nucleus locating at the cell edge after oil red O staining; unequal sized small vacuoles could be seen inside cytoplasm. Some small vacuoles merged big vacuoles. All these indi- cated a NAFLD rat model was successfully established by high fat diet. Pathological structural changes could be impaired to some degree in all medicated groups, especially in the SR group. (2) Compared with the normal control group, expression levels of LXRα and FAS genes and proteins obviously increased in the model group (P < 0.01). Compared with the model group, their expression levels were obviously down-regulated in the JR group and the SR group (P < 0.01, P < 0.05). LXRα/FAS signaling pathway was an important signaling pathway for mediating lipid metabolism disorders of NAFLD rats. SJR could make hepatocyte fatty deposits tend to repair by adjusting the LXRα/FAS signaling pathway in NAFLD rats, which might be one of important mechanisms for SJR to prevent and cure NAFLD.

Tobacco mosaic virus Movement Protein Enhances the Spread of RNA Silencing

PubMed Central

Vogler, Hannes; Kwon, Myoung-Ok; Dang, Vy; Sambade, Adrian; Fasler, Monika; Ashby, Jamie; Heinlein, Manfred

2008-01-01

Eukaryotic cells restrain the activity of foreign genetic elements, including viruses, through RNA silencing. Although viruses encode suppressors of silencing to support their propagation, viruses may also exploit silencing to regulate host gene expression or to control the level of their accumulation and thus to reduce damage to the host. RNA silencing in plants propagates from cell to cell and systemically via a sequence-specific signal. Since the signal spreads between cells through plasmodesmata like the viruses themselves, virus-encoded plasmodesmata-manipulating movement proteins (MP) may have a central role in compatible virus:host interactions by suppressing or enhancing the spread of the signal. Here, we have addressed the propagation of GFP silencing in the presence and absence of MP and MP mutants. We show that the protein enhances the spread of silencing. Small RNA analysis indicates that MP does not enhance the silencing pathway but rather enhances the transport of the signal through plasmodesmata. The ability to enhance the spread of silencing is maintained by certain MP mutants that can move between cells but which have defects in subcellular localization and do not support the spread of viral RNA. Using MP expressing and non-expressing virus mutants with a disabled silencing suppressing function, we provide evidence indicating that viral MP contributes to anti-viral silencing during infection. Our results suggest a role of MP in controlling virus propagation in the infected host by supporting the spread of silencing signal. This activity of MP involves only a subset of its properties implicated in the spread of viral RNA. PMID:18389061

The Arabidopsis LAZY1 Family Plays a Key Role in Gravity Signaling within Statocytes and in Branch Angle Control of Roots and Shoots.

PubMed

Taniguchi, Masatoshi; Furutani, Masahiko; Nishimura, Takeshi; Nakamura, Moritaka; Fushita, Toyohito; Iijima, Kohta; Baba, Kenichiro; Tanaka, Hirokazu; Toyota, Masatsugu; Tasaka, Masao; Morita, Miyo Terao

2017-08-01

During gravitropism, the directional signal of gravity is perceived by gravity-sensing cells called statocytes, leading to asymmetric distribution of auxin in the responding organs. To identify the genes involved in gravity signaling in statocytes, we performed transcriptome analyses of statocyte-deficient Arabidopsis thaliana mutants and found two candidates from the LAZY1 family, AtLAZY1 / LAZY1-LIKE1 ( LZY1 ) and AtDRO3 / AtNGR1 / LZY2 We showed that LZY1 , LZY2 , and a paralog AtDRO1/AtNGR2/LZY3 are redundantly involved in gravitropism of the inflorescence stem, hypocotyl, and root. Mutations of LZY genes affected early processes in gravity signal transduction without affecting amyloplast sedimentation. Statocyte-specific expression of LZY genes rescued the mutant phenotype, suggesting that LZY genes mediate gravity signaling in statocytes downstream of amyloplast displacement, leading to the generation of asymmetric auxin distribution in gravity-responding organs. We also found that lzy mutations reversed the growth angle of lateral branches and roots. Moreover, expression of the conserved C-terminal region of LZY proteins also reversed the growth direction of primary roots in the lzy mutant background. In lateral root tips of lzy multiple mutants, asymmetric distribution of PIN3 and auxin response were reversed, suggesting that LZY genes regulate the direction of polar auxin transport in response to gravity through the control of asymmetric PIN3 expression in the root cap columella. © 2017 American Society of Plant Biologists. All rights reserved.

An Evolutionarily Conserved DOF-CONSTANS Module Controls Plant Photoperiodic Signaling1[OPEN

PubMed Central

2015-01-01

The response to daylength is a crucial process that evolved very early in plant evolution, entitling the early green eukaryote to predict seasonal variability and attune its physiological responses to the environment. The photoperiod responses evolved into the complex signaling pathways that govern the angiosperm floral transition today. The Chlamydomonas reinhardtii DNA-Binding with One Finger (CrDOF) gene controls transcription in a photoperiod-dependent manner, and its misexpression influences algal growth and viability. In short days, CrDOF enhances CrCO expression, a homolog of plant CONSTANS (CO), by direct binding to its promoter, while it reduces the expression of cell division genes in long days independently of CrCO. In Arabidopsis (Arabidopsis thaliana), transgenic plants overexpressing CrDOF show floral delay and reduced expression of the photoperiodic genes CO and FLOWERING LOCUS T. The conservation of the DOF-CO module during plant evolution could be an important clue to understanding diversification by the inheritance of conserved gene toolkits in key developmental programs. PMID:25897001

Prenatal retinoic acid upregulates pulmonary gene expression of PI3K and AKT in nitrofen-induced pulmonary hypoplasia.

PubMed

Doi, Takashi; Sugimoto, Kaoru; Ruttenstock, Elke; Dingemann, Jens; Puri, Prem

2010-10-01

The precise mechanism of pulmonary hypoplasia associated with congenital diaphragmatic hernia (CDH) still remains unclear. Recently, prenatal treatment with retinoic acid (RA) has been reported to stimulate alveologenesis in hypoplastic lungs in the nitrofen model of CDH. The serine/threonine protein kinase B (AKT) plays a key role in lung morphogenesis through epithelial-mesenchymal interaction in phosphatidylinositide 3-kinase (PI3K)-dependent manner. It has been reported that the lung morphogenesis in explants in mice is interfered by inhibitors of PI3K-AKT signaling pathway. Furthermore, we have recently shown that nitrofen inhibits PI3K-AKT signaling during mid-to-late lung morphogenesis in the nitrofen-induced hypoplastic lung. We hypothesized that prenatal administration of RA upregulates pulmonary gene expression of PI3K and AKT in the nitrofen-induced hypoplastic lung. Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). 5 mg/kg of RA was given on D18, D19 and D20. The fetuses were harvested on D21, and fetal lungs were obtained and divided into four groups: control, control + RA, nitrofen, nitrofen + RA. The mRNA expression levels of PI3K and AKT were analyzed in each lung by real-time RT-PCR and statistically analyzed. Immunohistochemistry was also performed to evaluate protein expression of PI3K and AKT in the fetal lungs at D21. The pulmonary gene expression levels of PI3K and AKT were significantly upregulated in nitrofen + RA group compared to nitrofen group and control + RA group (p < 0.05), whereas there were no significant differences between controls and control + RA group. Immunoreactivity of PI3K and AKT was markedly increased in nitrofen + RA lungs compared to nitrofen-induced hypoplastic lungs. Upregulation of PI3K and AKT genes after prenatal treatment with RA in the nitrofen-induced hypoplastic lung suggests that RA may have a therapeutic potential in modulating lung alveologenesis by stimulating epithelial-mesenchymal interaction via PI3K-AKT signaling.

IL-6-Type Cytokine Signaling in Adipocytes Induces Intestinal GLP-1 Secretion.

PubMed

Wueest, Stephan; Laesser, Céline I; Böni-Schnetzler, Marianne; Item, Flurin; Lucchini, Fabrizio C; Borsigova, Marcela; Müller, Werner; Donath, Marc Y; Konrad, Daniel

2018-01-01

We recently showed that interleukin (IL)-6-type cytokine signaling in adipocytes induces free fatty acid release from visceral adipocytes, thereby promoting obesity-induced hepatic insulin resistance and steatosis. In addition, IL-6-type cytokines may increase the release of leptin from adipocytes and by those means induce glucagon-like peptide 1 (GLP-1) secretion. We thus hypothesized that IL-6-type cytokine signaling in adipocytes may regulate insulin secretion. To this end, mice with adipocyte-specific knockout of gp130, the signal transducer protein of IL-6, were fed a high-fat diet for 12 weeks. Compared with control littermates, knockout mice showed impaired glucose tolerance and circulating leptin, GLP-1, and insulin levels were reduced. In line, leptin release from isolated adipocytes was reduced, and intestinal proprotein convertase subtilisin/kexin type 1 ( Pcsk1 ) expression, the gene encoding PC1/3, which controls GLP-1 production, was decreased in knockout mice. Importantly, treatment with the GLP-1 receptor antagonist exendin 9-39 abolished the observed difference in glucose tolerance between control and knockout mice. Ex vivo, supernatant collected from isolated adipocytes of gp130 knockout mice blunted Pcsk1 expression and GLP-1 release from GLUTag cells. In contrast, glucose- and GLP-1-stimulated insulin secretion was not affected in islets of knockout mice. In conclusion, adipocyte-specific IL-6 signaling induces intestinal GLP-1 release to enhance insulin secretion, thereby counteracting insulin resistance in obesity. © 2017 by the American Diabetes Association.

Ubx dynamically regulates Dpp signaling by repressing Dad expression during copper cell regeneration in the adult Drosophila midgut

PubMed Central

Li, Hongjie; Qi, Yanyan; Jasper, Heinrich

2016-01-01

The gastrointestinal (GI) tract of metazoans is lined by a series of regionally distinct epithelia. To maintain structure and function of the GI tract, regionally diversified differentiation of somatic stem cell (SC) lineages is critical. The adult Drosophila midgut provides an accessible model to study SC regulation and specification in a regionally defined manner. SCs of the posterior midgut (PM) have been studied extensively, but the control of SCs in the middle midgut (MM) is less well understood. The MM contains a stomach-like copper cell region (CCR) that is regenerated by gastric stem cells (GSSCs) and contains acid-secreting copper cells (CCs). Bmp-like Decapentaplegic (Dpp) signaling determines the identity of GSSCs, and is required for CC regeneration, yet the precise control of Dpp signaling activity in this lineage remains to be fully established. Here, we show that Dad, a negative feedback regulator of Dpp signaling, is dynamically regulated in the GSSC lineage to allow CC differentiation. Dad is highly expressed in GSSCs and their first daughter cells, the gastroblasts (GBs), but has to be repressed in differentiating CCs to allow Dpp-mediated differentiation into CCs. We find that the Hox gene ultrabithorax (Ubx) is required for this regulation. Loss of Ubx prevents Dad repression in the CCR, resulting in defective CC regeneration. Our study highlights the need for dynamic control of Dpp signaling activity in the differentiation of the GSSC lineage and identifies Ubx as a critical regulator of this process. PMID:27570230

Unbiased RNAi screen for hepcidin regulators links hepcidin suppression to proliferative Ras/RAF and nutrient-dependent mTOR signaling

PubMed Central

Mleczko-Sanecka, Katarzyna; Roche, Franziska; Rita da Silva, Ana; Call, Debora; D’Alessio, Flavia; Ragab, Anan; Lapinski, Philip E.; Ummanni, Ramesh; Korf, Ulrike; Oakes, Christopher; Damm, Georg; D’Alessandro, Lorenza A.; Klingmüller, Ursula; King, Philip D.; Boutros, Michael; Hentze, Matthias W.

2014-01-01

The hepatic hormone hepcidin is a key regulator of systemic iron metabolism. Its expression is largely regulated by 2 signaling pathways: the “iron-regulated” bone morphogenetic protein (BMP) and the inflammatory JAK-STAT pathways. To obtain broader insights into cellular processes that modulate hepcidin transcription and to provide a resource to identify novel genetic modifiers of systemic iron homeostasis, we designed an RNA interference (RNAi) screen that monitors hepcidin promoter activity after the knockdown of 19 599 genes in hepatocarcinoma cells. Interestingly, many of the putative hepcidin activators play roles in signal transduction, inflammation, or transcription, and affect hepcidin transcription through BMP-responsive elements. Furthermore, our work sheds light on new components of the transcriptional machinery that maintain steady-state levels of hepcidin expression and its responses to the BMP- and interleukin-6–triggered signals. Notably, we discover hepcidin suppression mediated via components of Ras/RAF MAPK and mTOR signaling, linking hepcidin transcriptional control to the pathways that respond to mitogen stimulation and nutrient status. Thus using a combination of RNAi screening, reverse phase protein arrays, and small molecules testing, we identify links between the control of systemic iron homeostasis and critical liver processes such as regeneration, response to injury, carcinogenesis, and nutrient metabolism. PMID:24385536

Epithelial Control of Gut-Associated Lymphoid Tissue Formation through p38α-Dependent Restraint of NF-κB Signaling.

PubMed

Caballero-Franco, Celia; Guma, Monica; Choo, Min-Kyung; Sano, Yasuyo; Enzler, Thomas; Karin, Michael; Mizoguchi, Atsushi; Park, Jin Mo

2016-03-01

The protein kinase p38α mediates cellular responses to environmental and endogenous cues that direct tissue homeostasis and immune responses. Studies of mice lacking p38α in several different cell types have demonstrated that p38α signaling is essential to maintaining the proliferation-differentiation balance in developing and steady-state tissues. The mechanisms underlying these roles involve cell-autonomous control of signaling and gene expression by p38α. In this study, we show that p38α regulates gut-associated lymphoid tissue (GALT) formation in a noncell-autonomous manner. From an investigation of mice with intestinal epithelial cell-specific deletion of the p38α gene, we find that p38α serves to limit NF-κB signaling and thereby attenuate GALT-promoting chemokine expression in the intestinal epithelium. Loss of this regulation results in GALT hyperplasia and, in some animals, mucosa-associated B cell lymphoma. These anomalies occur independently of luminal microbial stimuli and are most likely driven by direct epithelial-lymphoid interactions. Our study illustrates a novel p38α-dependent mechanism preventing excessive generation of epithelial-derived signals that drive lymphoid tissue overgrowth and malignancy. Copyright © 2016 by The American Association of Immunologists, Inc.

A universal reference sample derived from clone vector for improved detection of differential gene expression

PubMed Central

Khan, Rishi L; Gonye, Gregory E; Gao, Guang; Schwaber, James S

2006-01-01

Background Using microarrays by co-hybridizing two samples labeled with different dyes enables differential gene expression measurements and comparisons across slides while controlling for within-slide variability. Typically one dye produces weaker signal intensities than the other often causing signals to be undetectable. In addition, undetectable spots represent a large problem for two-color microarray designs and most arrays contain at least 40% undetectable spots even when labeled with reference samples such as Stratagene's Universal Reference RNAs™. Results We introduce a novel universal reference sample that produces strong signal for all spots on the array, increasing the average fraction of detectable spots to 97%. Maximizing detectable spots on the reference image channel also decreases the variability of microarray data allowing for reliable detection of smaller differential gene expression changes. The reference sample is derived from sequence contained in the parental EST clone vector pT7T3D-Pac and is called vector RNA (vRNA). We show that vRNA can also be used for quality control of microarray printing and PCR product quality, detection of hybridization anomalies, and simplification of spot finding and segmentation tasks. This reference sample can be made inexpensively in large quantities as a renewable resource that is consistent across experiments. Conclusion Results of this study show that vRNA provides a useful universal reference that yields high signal for almost all spots on a microarray, reduces variation and allows for comparisons between experiments and laboratories. Further, it can be used for quality control of microarray printing and PCR product quality, detection of hybridization anomalies, and simplification of spot finding and segmentation tasks. This type of reference allows for detection of small changes in differential expression while reference designs in general allow for large-scale multivariate experimental designs. vRNA in combination with reference designs enable systems biology microarray experiments of small physiologically relevant changes. PMID:16677381

Quantification of shape and cell polarity reveals a novel mechanism underlying malformations resulting from related FGF mutations during facial morphogenesis

PubMed Central

Li, Xin; Young, Nathan M.; Tropp, Stephen; Hu, Diane; Xu, Yanhua; Hallgrímsson, Benedikt; Marcucio, Ralph S.

2013-01-01

Fibroblast growth factor (FGF) signaling mutations are a frequent contributor to craniofacial malformations including midfacial anomalies and craniosynostosis. FGF signaling has been shown to control cellular mechanisms that contribute to facial morphogenesis and growth such as proliferation, survival, migration and differentiation. We hypothesized that FGF signaling not only controls the magnitude of growth during facial morphogenesis but also regulates the direction of growth via cell polarity. To test this idea, we infected migrating neural crest cells of chicken embryos with  replication-competent avian sarcoma virus expressing either FgfR2C278F, a receptor mutation found in Crouzon syndrome or the ligand Fgf8. Treated embryos exhibited craniofacial malformations resembling facial dysmorphologies in craniosynostosis syndrome. Consistent with our hypothesis, ectopic activation of FGF signaling resulted in decreased cell proliferation, increased expression of the Sprouty class of FGF signaling inhibitors, and repressed phosphorylation of ERK/MAPK. Furthermore, quantification of cell polarity in facial mesenchymal cells showed that while orientation of the Golgi body matches the direction of facial prominence outgrowth in normal cells, in FGF-treated embryos this direction is randomized, consistent with aberrant growth that we observed. Together, these data demonstrate that FGF signaling regulates cell proliferation and cell polarity and that these cell processes contribute to facial morphogenesis. PMID:23906837

Ectopic Activation of Wnt/β-Catenin Signaling in Lens Fiber Cells Results in Cataract Formation and Aberrant Fiber Cell Differentiation

PubMed Central

Antosova, Barbora; Smolikova, Jana; Borkovcova, Romana; Strnad, Hynek; Lachova, Jitka; Machon, Ondrej; Kozmik, Zbynek

2013-01-01

The Wnt/β-catenin signaling pathway controls many processes during development, including cell proliferation, cell differentiation and tissue homeostasis, and its aberrant regulation has been linked to various pathologies. In this study we investigated the effect of ectopic activation of Wnt/β-catenin signaling during lens fiber cell differentiation. To activate Wnt/β-catenin signaling in lens fiber cells, the transgenic mouse referred to as αA-CLEF was generated, in which the transactivation domain of β-catenin was fused to the DNA-binding protein LEF1, and expression of the transgene was controlled by αA-crystallin promoter. Constitutive activation of Wnt/β-catenin signaling in lens fiber cells of αA-CLEF mice resulted in abnormal and delayed fiber cell differentiation. Moreover, adult αA-CLEF mice developed cataract, microphthalmia and manifested downregulated levels of γ-crystallins in lenses. We provide evidence of aberrant expression of cell cycle regulators in embryonic lenses of αA-CLEF transgenic mice resulting in the delay in cell cycle exit and in the shift of fiber cell differentiation to the central fiber cell compartment. Our results indicate that precise regulation of the Wnt/β-catenin signaling activity during later stages of lens development is essential for proper lens fiber cell differentiation and lens transparency. PMID:24205179

Endothelial cell expression of haemoglobin α regulates nitric oxide signalling.

PubMed

Straub, Adam C; Lohman, Alexander W; Billaud, Marie; Johnstone, Scott R; Dwyer, Scott T; Lee, Monica Y; Bortz, Pamela Schoppee; Best, Angela K; Columbus, Linda; Gaston, Benjamin; Isakson, Brant E

2012-11-15

Models of unregulated nitric oxide (NO) diffusion do not consistently account for the biochemistry of NO synthase (NOS)-dependent signalling in many cell systems. For example, endothelial NOS controls blood pressure, blood flow and oxygen delivery through its effect on vascular smooth muscle tone, but the regulation of these processes is not adequately explained by simple NO diffusion from endothelium to smooth muscle. Here we report a new model for the regulation of NO signalling by demonstrating that haemoglobin (Hb) α (encoded by the HBA1 and HBA2 genes in humans) is expressed in human and mouse arterial endothelial cells and enriched at the myoendothelial junction, where it regulates the effects of NO on vascular reactivity. Notably, this function is unique to Hb α and is abrogated by its genetic depletion. Mechanistically, endothelial Hb α haem iron in the Fe(3+) state permits NO signalling, and this signalling is shut off when Hb α is reduced to the Fe(2+) state by endothelial cytochrome b5 reductase 3 (CYB5R3, also known as diaphorase 1). Genetic and pharmacological inhibition of CYB5R3 increases NO bioactivity in small arteries. These data reveal a new mechanism by which the regulation of the intracellular Hb α oxidation state controls NOS signalling in non-erythroid cells. This model may be relevant to haem-containing globins in a broad range of NOS-containing somatic cells.

Differentiating Human Multipotent Mesenchymal Stromal Cells Regulate microRNAs: Prediction of microRNA Regulation by PDGF During Osteogenesis

PubMed Central

Goff, Loyal A.; Boucher, Shayne; Ricupero, Christopher L.; Fenstermacher, Sara; Swerdel, Mavis; Chase, Lucas; Adams, Christopher; Chesnut, Jonathan; Lakshmipathy, Uma; Hart, Ronald P.

2009-01-01

Objective Human multipotent mesenchymal stromal cells (MSC) have the potential to differentiate into multiple cell types, although little is known about factors that control their fate. Differentiation-specific microRNAs may play a key role in stem cell self renewal and differentiation. We propose that specific intracellular signalling pathways modulate gene expression during differentiation by regulating microRNA expression. Methods Illumina mRNA and NCode microRNA expression analyses were performed on MSC and their differentiated progeny. A combination of bioinformatic prediction and pathway inhibition was used to identify microRNAs associated with PDGF signalling. Results The pattern of microRNA expression in MSC is distinct from that in pluripotent stem cells such as human embryonic stem cells. Specific populations of microRNAs are regulated in MSC during differentiation targeted towards specific cell types. Complementary mRNA expression analysis increases the pool of markers characteristic of MSC or differentiated progeny. To identify microRNA expression patterns affected by signalling pathways, we examined the PDGF pathway found to be regulated during osteogenesis by microarray studies. A set of microRNAs bioinformatically predicted to respond to PDGF signalling was experimentally confirmed by direct PDGF inhibition. Conclusion Our results demonstrate that a subset of microRNAs regulated during osteogenic differentiation of MSCs is responsive to perturbation of the PDGF pathway. This approach not only identifies characteristic classes of differentiation-specific mRNAs and microRNAs, but begins to link regulated molecules with specific cellular pathways. PMID:18657893

Parabolic flight induces changes in gene expression patterns in Arabidopsis thaliana.

PubMed

Paul, Anna-Lisa; Manak, Michael S; Mayfield, John D; Reyes, Matthew F; Gurley, William B; Ferl, Robert J

2011-10-01

Our primary objective was to evaluate gene expression changes in Arabidopsis thaliana in response to parabolic flight as part of a comprehensive approach to the molecular biology of spaceflight-related adaptations. In addition, we wished to establish parabolic flight as a tractable operations platform for molecular biology studies. In a succession of experiments on NASA's KC-135 and C-9 parabolic aircraft, Arabidopsis plants were presented with replicated exposure to parabolic flight. Transcriptome profiling revealed that parabolic flight caused changes in gene expression patterns that stood the statistical tests of replication on three different flight days. The earliest response, after 20 parabolas, was characterized by a prominence of genes associated with signal transduction. After 40 parabolas, this prominence was largely replaced by genes associated with biotic and abiotic stimuli and stress. Among these responses, three metabolic processes stand out in particular: the induction of auxin metabolism and signaling, the differential expression of genes associated with calcium-mediated signaling, and the repression of genes associated with disease resistance and cell wall biochemistry. Many, but not all, of these responses are known to be involved in gravity sensing in plants. Changes in auxin-related gene expression were also recorded by reporter genes tuned to auxin signal pathways. These data demonstrate that the parabolic flight environment is appropriate for molecular biology research involving the transition to microgravity, in that with replication, proper controls, and analyses, gene expression changes can be observed in the time frames of typical parabolic flight experiments.

Gene Expression Profiling and Molecular Signaling of Various Cells in Response to Tricalcium Silicate Cements: A Systematic Review.

PubMed

Rathinam, Elanagai; Rajasekharan, Sivaprakash; Chitturi, Ravi Teja; Declercq, Heidi; Martens, Luc; De Coster, Peter

2016-12-01

The aim of this study was to present a systematic review investigating the gene expression of various cells (other than dental pulp cells) in response to different variants of tricalcium silicate cements (TSCs). A systematic search of the literature was performed by 2 independent reviewers followed by article selection and data extraction. Studies analyzing any cell type except dental pulp stem cells and any variant of tricalcium silicate cement either as the experimental or as the control group were included. A total of 41 relevant articles were included in this review. Among the included studies, ProRoot MTA (Dentsply, Tulsa, OK) was the most commonly studied (69.1%) TSC variant, and 11 cell types were identified, with 13 articles investigating gene expression in osteoblasts. A total of 39 different genes/molecules expressed were found in the selected studies. The experimental group (irrespective of the TSC variant) was identified to express significantly increased gene expression compared with the control group (untreated) in all included studies. Recent studies have provided useful insight into the gene expression and molecular signaling of various cells in response to TSCs, and new elements have been supplied on the pathways activated in this process. TSCs are capable of eliciting a favorable cellular response in periapical regeneration. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Ephrin type-A receptor 2 regulates sensitivity to paclitaxel in nasopharyngeal carcinoma via the phosphoinositide 3-kinase/Akt signalling pathway

PubMed Central

WANG, YUNYUN; LIU, YONG; LI, GUO; SU, ZHONGWU; REN, SHULING; TAN, PINGQING; ZHANG, XIN; QIU, YUANZHENG; TIAN, YONGQUAN

2015-01-01

Ephrin type-A receptor 2 (EphA2) is a receptor tyrosine kinase that is associated with cancer cell metastasis. There has been little investigation into its impact on the regulation of sensitivity to paclitaxel in nasopharyngeal carcinoma (NPC). In the present study, upregulation of EphA2 expression enhanced the survival of NPC 5-8F cells, compared with control cells exposed to the same concentrations of paclitaxel. Flow cytometry and western blot analysis demonstrated that over-expression of EphA2 decreased NPC cancer cell sensitivity to paclitaxel by regulating paclitaxel-mediated cell cycle progression but not apoptosis in vitro. This was accompanied by alterations in the expression of cyclin-dependent kinase inhibitors, p21 and p27, and of inactive phosphorylated-retinoblastoma protein. Furthermore, paclitaxel stimulation and EphA2 over-expression resulted in activation of the phosphoinositide 3-kinase (PI3K)/Akt signalling pathway in NPC cells. Inhibition of the PI3K/Akt signalling pathway restored sensitivity to paclitaxel in 5-8F cells over-expressing EphA2, which indicated that the PI3K/Akt pathway is involved in EphA2-mediated paclitaxel sensitivity. The current study demonstrated that EphA2 mediates sensitivity to paclitaxel via the regulation of the PI3K/Akt signalling pathway in NPC. PMID:25351620

Hepatic stellate cell and myofibroblast-like cell gene expression in the explanted cirrhotic livers of patients undergoing liver transplantation.

PubMed

Estep, J Michael; O'Reilly, Linda; Grant, Geraldine; Piper, James; Jonsson, Johann; Afendy, Arian; Chandhoke, Vikas; Younossi, Zobair M

2010-02-01

Hepatic stellate cells (HSC) are involved in hepatic fibrogenesis. Cell signaling associated with an insult to the liver affects an HSC transdifferentiation to fibrogenic myofibroblast-like cells. To investigate the transcriptional expression distinguishing HSC and myofibroblast-like cells between livers with and without cirrhosis. Tissue from ten cirrhotic livers (undergoing transplant) and four non-cirrhotic livers from the National Disease Research Interchange underwent cell separation to extract HSC and myofibroblast-like cell populations. Separated cell types as well as LI-90 cells were subjected to microarray analysis. Selected microarray results were verified by quantitative real-time PCR. Differential expression of some genes, such as IL-1beta, IL-1alpha, and IL-6, was associated with both transdifferentiation and disease. Other genes, such as fatty acid 2-hydroxylase only show differential expression in association with disease. Functional analysis supported these findings, indicating some signal transduction pathways (IL-6) are involved in disease and activation, whereas retinoid X receptor signaling in HSC from cirrhotic and non-cirrhotic livers varies in scope and quality. These findings indicate distinct phenotypes for HSC from cirrhotic and non-cirrhotic livers. Furthermore, coordinated differential expression between genes involved in the same signal transduction pathways provides some insight into the mechanisms that may control the balance between fibrogenesis and fibrolysis.

PDF Receptor Expression Reveals Direct Interactions between Circadian Oscillators in Drosophila

PubMed Central

Im, Seol Hee; Taghert, Paul H.

2010-01-01

Daily rhythms of behavior are controlled by a circuit of circadian pacemaking neurons. In Drosophila, 150 pacemakers participate in this network, and recent observations suggest the network is divisible into M and E oscillators which normally interact and synchronize. Sixteen oscillator neurons (the small and large LNvs) express a neuropeptide called pigment dispersing factor (PDF) whose signaling is often equated with M oscillator output. Given the significance of PDF signaling to numerous aspects of behavioral and molecular rhythms, determining precisely where and how signaling via the PDF receptor (PDFR) occurs is now a central question in the field. Here we show that GAL4-mediated rescue of pdfr phenotypes using a UAS-PDFR transgene is insufficient to provide complete behavioral rescue. In contrast, we describe a ~70 kB PDF receptor (pdfr) transgene which does rescue the entire pdfr circadian behavioral phenotype. The transgene is widely but heterogeneously expressed among pacemakers, and also among a limited number of non-pacemakers. Our results support an important hypothesis: the small LNv cells directly target a subset of the other crucial pacemaker neurons cells. Furthermore, expression of the transgene confirms an autocrine feedback signaling by PDF back to PDF-expressing cells. Finally, the results present an unexpected PDF receptor site: the large LNv cells appear to target a population of non-neuronal cells that resides at the base of the eye. PMID:20394051

Cinnamon extract regulates glucose transporter and insulin-signaling gene expression in mouse adipocytes.

PubMed

Cao, Heping; Graves, Donald J; Anderson, Richard A

2010-11-01

Cinnamon extracts (CE) are reported to have beneficial effects on people with normal and impaired glucose tolerance, the metabolic syndrome, type 2 diabetes, and insulin resistance. However, clinical results are controversial. Molecular characterization of CE effects is limited. This study investigated the effects of CE on gene expression in cultured mouse adipocytes. Water-soluble CE was prepared from ground cinnamon (Cinnamomum burmannii). Quantitative real-time PCR was used to investigate CE effects on the expression of genes coding for adipokines, glucose transporter (GLUT) family, and insulin-signaling components in mouse 3T3-L1 adipocytes. CE (100 μg/ml) increased GLUT1 mRNA levels 1.91±0.15, 4.39±0.78, and 6.98±2.18-fold of the control after 2-, 4-, and 16-h treatments, respectively. CE decreased the expression of further genes encoding insulin-signaling pathway proteins including GSK3B, IGF1R, IGF2R, and PIK3R1. This study indicates that CE regulates the expression of multiple genes in adipocytes and this regulation could contribute to the potential health benefits of CE. Published by Elsevier GmbH.

Notch Signaling Is Involved in Neurogenic Commitment of Human Periodontal Ligament-Derived Mesenchymal Stem Cells

PubMed Central

Osathanon, Thanaphum; Manokawinchoke, Jeeranan; Nowwarote, Nunthawan; Aguilar, Panuroot; Palaga, Tanapat

2013-01-01

Notch signaling plays critical roles in stem cells by regulating cell fate determination and differentiation. The aim of this study was to evaluate the participation of Notch signaling in neurogenic commitment of human periodontal ligament-derived mesenchymal stem cells (hPDLSCs) and to examine the ability to control differentiation of these cells using modified surfaces containing affinity immobilized Notch ligands. Neurogenic induction of hPDLSCs was performed via neurosphere formation. Cells were aggregated and form spheres as early 1 day in culture. In addition, the induced cells exhibited increased mRNA and protein expression of neuronal markers that is, β3-tubulin and neurofilament. During neuronal differentiation, a significant increase of Hes1 and Hey1 mRNA expression was noted. Using pharmacological inhibition (γ-secretase inhibitor) or genetic manipulation (overexpression of dominant negative mastermind-like transcription co-activators), neurosphere formation was attenuated and a marked decrease in neurogenic mRNA expression was observed. To confirm the role of Notch signaling in neuronal differentiation of hPDLSCs, the Notch ligand, Jagged-1, is bound to the surface using an affinity immobilization technique. The hPDLSC cultured on a Jagged-1-modified surface had increased expression of Notch signaling target genes, Hes-1 and Hey-1, confirming the activity and potency of surface-bound Jagged-1. Further, hPDLSC on surface-bound Jagged-1 under serum-free conditions showed multiple long and thin neurite-like extensions, and an increase in the expression of neurogenic mRNA markers was observed. Pretreatment of the cells with γ-secretase inhibitor, DAPT, before seeding on the Jagged-1-modified surface blocked development of the neurite-like morphology. Together, the results in this study suggest the involvement of Notch signaling in neurogenic commitment of hPDLSCs. PMID:23379739

Fetal alcohol exposure disrupts metabolic signaling in hypothalamic proopiomelanocortin neurons via a circadian mechanism in male mice.

PubMed

Agapito, Maria A; Zhang, Changqing; Murugan, Sengottuvelan; Sarkar, Dipak K

2014-07-01

Early-life ethanol feeding (ELAF) alters the metabolic function of proopiomelanocortin (POMC)-producing neurons and the circadian expression of clock regulatory genes in the hypothalamus. We investigated whether the circadian mechanisms control the action of ELAF on metabolic signaling genes in POMC neurons. Gene expression measurements of Pomc and a selected group of metabolic signaling genes, Stat3, Sirt1, Pgc1-α, and Asb4 in laser-captured microdissected POMC neurons in the hypothalamus of POMC-enhanced green fluorescent protein mice showed circadian oscillations under light/dark and constant darkness conditions. Ethanol programmed these neurons such that the adult expression of Pomc, Stat3, Sirt, and Asb4 gene transcripts became arrhythmic. In addition, ELAF dampened the circadian peak of gene expression of Bmal1, Per1, and Per2 in POMC neurons. We crossed Per2 mutant mice with transgenic POMC-enhanced green fluorescent protein mice to determine the role of circadian mechanism in ELAF-altered metabolic signaling in POMC neurons. We found that ELAF failed to alter arrhythmic expression of most circadian genes, with the exception of the Bmal1 gene and metabolic signaling regulating genes in Per2 mutant mice. Comparison of the ELAF effects on the circadian blood glucose in wild-type and Per2 mutant mice revealed that ELAF dampened the circadian peak of glucose, whereas the Per2 mutation shifted the circadian cycle and prevented the ELAF dampening of the glucose peak. These data suggest the possibility that the Per2 gene mutation may regulate the ethanol actions on Pomc and the metabolic signaling genes in POMC neurons in the hypothalamus by blocking circadian mechanisms.

A review of hedgehog signaling in cranial bone development

PubMed Central

Pan, Angel; Chang, Le; Nguyen, Alan; James, Aaron W.

2013-01-01

During craniofacial development, the Hedgehog (HH) signaling pathway is essential for mesodermal tissue patterning and differentiation. The HH family consists of three protein ligands: Sonic Hedgehog (SHH), Indian Hedgehog (IHH), and Desert Hedgehog (DHH), of which two are expressed in the craniofacial complex (IHH and SHH). Dysregulations in HH signaling are well documented to result in a wide range of craniofacial abnormalities, including holoprosencephaly (HPE), hypotelorism, and cleft lip/palate. Furthermore, mutations in HH effectors, co-receptors, and ciliary proteins result in skeletal and craniofacial deformities. Cranial suture morphogenesis is a delicate developmental process that requires control of cell commitment, proliferation and differentiation. This review focuses on both what is known and what remains unknown regarding HH signaling in cranial suture morphogenesis and intramembranous ossification. As demonstrated from murine studies, expression of both SHH and IHH is critical to the formation and fusion of the cranial sutures and calvarial ossification. SHH expression has been observed in the cranial suture mesenchyme and its precise function is not fully defined, although some postulate SHH to delay cranial suture fusion. IHH expression is mainly found on the osteogenic fronts of the calvarial bones, and functions to induce cell proliferation and differentiation. Unfortunately, neonatal lethality of IHH deficient mice precludes a detailed examination of their postnatal calvarial phenotype. In summary, a number of basic questions are yet to be answered regarding domains of expression, developmental role, and functional overlap of HH morphogens in the calvaria. Nevertheless, SHH and IHH ligands are integral to cranial suture development and regulation of calvarial ossification. When HH signaling goes awry, the resultant suite of morphologic abnormalities highlights the important roles of HH signaling in cranial development. PMID:23565096

Expression profiling and structural characterization of microRNAs in adipose tissues of hibernating ground squirrels.

PubMed

Wu, Cheng-Wei; Biggar, Kyle K; Storey, Kenneth B

2014-12-01

MicroRNAs (miRNAs) are small non-coding RNAs that are important in regulating metabolic stress. In this study, we determined the expression and structural characteristics of 20 miRNAs in brown (BAT) and white adipose tissue (WAT) during torpor in thirteen-lined ground squirrels. Using a modified stem-loop technique, we found that during torpor, expression of six miRNAs including let-7a, let-7b, miR-107, miR-150, miR-222 and miR-31 was significantly downregulated in WAT (P<0.05), which was 16%-54% of euthermic non-torpid control squirrels, whereas expression of three miRNAs including miR-143, miR-200a and miR-519d was found to be upregulated by 1.32-2.34-fold. Similarly, expression of more miRNAs was downregulated in BAT during torpor. We detected reduced expression of 6 miRNAs including miR-103a, miR-107, miR-125b, miR-21, miR-221 and miR-31 (48%-70% of control), while only expression of miR-138 was significantly upregulated (2.91±0.8-fold of the control, P<0.05). Interestingly, miRNAs found to be downregulated in WAT during torpor were similar to those dysregulated in obese humans for increased adipogenesis, whereas miRNAs with altered expression in BAT during torpor were linked to mitochondrial β-oxidation. miRPath target prediction analysis showed that miRNAs downregulated in both WAT and BAT were associated with the regulation of mitogen-activated protein kinase (MAPK) signaling, while the miRNAs upregulated in WAT were linked to transforming growth factor β (TGFβ) signaling. Compared to mouse sequences, no unique nucleotide substitutions within the stem-loop region were discovered for the associated pre-miRNAs for the miRNAs used in this study, suggesting no structure-influenced changes in pre-miRNA processing efficiency in the squirrel. As well, the expression of miRNA processing enzyme Dicer remained unchanged in both tissues during torpor. Overall, our findings suggest that changes of miRNA expression in adipose tissues may be linked to distinct biological roles in WAT and BAT during hibernation and may involve the regulation of signaling cascades. Copyright © 2014 The Authors. Production and hosting by Elsevier Ltd.. All rights reserved.

Genome-Wide Expression Profiling of Complex Regional Pain Syndrome

PubMed Central

Jin, Eun-Heui; Zhang, Enji; Ko, Youngkwon; Sim, Woo Seog; Moon, Dong Eon; Yoon, Keon Jung; Hong, Jang Hee; Lee, Won Hyung

2013-01-01

Complex regional pain syndrome (CRPS) is a chronic, progressive, and devastating pain syndrome characterized by spontaneous pain, hyperalgesia, allodynia, altered skin temperature, and motor dysfunction. Although previous gene expression profiling studies have been conducted in animal pain models, there genome-wide expression profiling in the whole blood of CRPS patients has not been reported yet. Here, we successfully identified certain pain-related genes through genome-wide expression profiling in the blood from CRPS patients. We found that 80 genes were differentially expressed between 4 CRPS patients (2 CRPS I and 2 CRPS II) and 5 controls (cut-off value: 1.5-fold change and p<0.05). Most of those genes were associated with signal transduction, developmental processes, cell structure and motility, and immunity and defense. The expression levels of major histocompatibility complex class I A subtype (HLA-A29.1), matrix metalloproteinase 9 (MMP9), alanine aminopeptidase N (ANPEP), l-histidine decarboxylase (HDC), granulocyte colony-stimulating factor 3 receptor (G-CSF3R), and signal transducer and activator of transcription 3 (STAT3) genes selected from the microarray were confirmed in 24 CRPS patients and 18 controls by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). We focused on the MMP9 gene that, by qRT-PCR, showed a statistically significant difference in expression in CRPS patients compared to controls with the highest relative fold change (4.0±1.23 times and p = 1.4×10−4). The up-regulation of MMP9 gene in the blood may be related to the pain progression in CRPS patients. Our findings, which offer a valuable contribution to the understanding of the differential gene expression in CRPS may help in the understanding of the pathophysiology of CRPS pain progression. PMID:24244504

Gallic acid inhibits gastric cancer cells metastasis and invasive growth via increased expression of RhoB, downregulation of AKT/small GTPase signals and inhibition of NF-κB activity

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

Ho, Hsieh-Hsun; Chang, Chi-Sen; Division of Gastroenterology, Taichung Veterans General Hospital, Taichung 402, Taiwan

2013-01-01

Our previous study demonstrated the therapeutic potential of gallic acid (GA) for controlling tumor metastasis through its inhibitory effect on the motility of AGS cells. A noteworthy finding in our previous experiment was increased RhoB expression in GA-treated cells. The aim of this study was to evaluate the role of RhoB expression on the inhibitory effects of GA on AGS cells. By applying the transfection of RhoB siRNA into AGS cells and an animal model, we tested the effect of GA on inhibition of tumor growth and RhoB expression. The results confirmed that RhoB-siRNA transfection induced GA to inhibit AGSmore » cells’ invasive growth involving blocking the AKT/small GTPase signals pathway and inhibition of NF-κB activity. Finally, we evaluated the effect of GA on AGS cell metastasis by colonization of tumor cells in nude mice. It showed GA inhibited tumor cells growth via the expression of RhoB. These data support the inhibitory effect of GA which was shown to inhibit gastric cancer cell metastasis and invasive growth via increased expression of RhoB, downregulation of AKT/small GTPase signals and inhibition of NF-κB activity. Thus, GA might be a potential agent in treating gastric cancer. Highlights: ► GA could downregulate AKT signal via increased expression of RhoB. ► GA inhibits metastasis in vitro in gastric carcinoma. ► GA inhibits tumor growth in nude mice model.« less

Molecular analysis of erection regulatory factors in sickle cell disease associated priapism in the human penis.

PubMed

Lagoda, Gwen; Sezen, Sena F; Cabrini, Marcelo R; Musicki, Biljana; Burnett, Arthur L

2013-02-01

Priapism is a vasculopathy that occurs in approximately 40% of patients with sickle cell disease. Mouse models suggest that dysregulated nitric oxide synthase and RhoA/ROCK signaling as well as increased oxidative stress may contribute to the mechanisms of sickle cell disease associated priapism. We examined changes in the protein expression of nitric oxide synthase and ROCK signaling pathways, and a source of oxidative stress, NADPH oxidase, in penile erectile tissue from patients with a priapism history etiologically related and unrelated to sickle cell disease. Human penile erectile tissue was obtained from 5 patients with sickle cell disease associated priapism and from 6 with priapism of other etiologies during nonemergent penile prosthesis surgery for erectile dysfunction or priapism management and urethroplasty. Tissue was also obtained from 5 control patients without a priapism history during penectomy for penile cancer. Samples were collected, immediately placed in cold buffer and then frozen in liquid nitrogen. The expression of phosphodiesterase 5, endothelial nitric oxide synthase, neuronal nitric oxide synthase, inducible nitric oxide synthase, RhoA, ROCK1, ROCK2, p47(phox), p67(phox), gp91(phox) and β-actin were determined by Western blot analysis. Nitric oxide was measured using the Griess reaction. In the sickle cell disease group phosphodiesterase 5 (p <0.05), endothelial nitric oxide synthase (p <0.01) and RhoA (p <0.01) expression was significantly decreased, while gp91(phox) expression (p <0.05) was significantly increased compared to control values. In the nonsickle cell disease group endothelial nitric oxide synthase, ROCK1 and p47(phox) expression (each p <0.05) was significantly decreased compared to control values. Total nitric oxide levels were not significantly different between the study groups. Mechanisms of sickle cell disease associated priapism in the human penis may involve dysfunctional nitric oxide synthase and ROCK signaling, and increased oxidative stress associated with NADPH oxidase mediated signaling. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

A postsynaptic PI3K-cII dependent signaling controller for presynaptic homeostatic plasticity

PubMed Central

Hauswirth, Anna G; Ford, Kevin J; Wang, Tingting; Fetter, Richard D; Tong, Amy

2018-01-01

Presynaptic homeostatic plasticity stabilizes information transfer at synaptic connections in organisms ranging from insect to human. By analogy with principles of engineering and control theory, the molecular implementation of PHP is thought to require postsynaptic signaling modules that encode homeostatic sensors, a set point, and a controller that regulates transsynaptic negative feedback. The molecular basis for these postsynaptic, homeostatic signaling elements remains unknown. Here, an electrophysiology-based screen of the Drosophila kinome and phosphatome defines a postsynaptic signaling platform that includes a required function for PI3K-cII, PI3K-cIII and the small GTPase Rab11 during the rapid and sustained expression of PHP. We present evidence that PI3K-cII localizes to Golgi-derived, clathrin-positive vesicles and is necessary to generate an endosomal pool of PI(3)P that recruits Rab11 to recycling endosomal membranes. A morphologically distinct subdivision of this platform concentrates postsynaptically where we propose it functions as a homeostatic controller for retrograde, trans-synaptic signaling. PMID:29303480

Activin Signaling Targeted by Insulin/dFOXO Regulates Aging and Muscle Proteostasis in Drosophila

PubMed Central

Bai, Hua; Kang, Ping; Hernandez, Ana Maria; Tatar, Marc

2013-01-01

Reduced insulin/IGF signaling increases lifespan in many animals. To understand how insulin/IGF mediates lifespan in Drosophila, we performed chromatin immunoprecipitation-sequencing analysis with the insulin/IGF regulated transcription factor dFOXO in long-lived insulin/IGF signaling genotypes. Dawdle, an Activin ligand, is bound and repressed by dFOXO when reduced insulin/IGF extends lifespan. Reduced Activin signaling improves performance and protein homeostasis in muscles of aged flies. Activin signaling through the Smad binding element inhibits the transcription of Autophagy-specific gene 8a (Atg8a) within muscle, a factor controlling the rate of autophagy. Expression of Atg8a within muscle is sufficient to increase lifespan. These data reveal how insulin signaling can regulate aging through control of Activin signaling that in turn controls autophagy, representing a potentially conserved molecular basis for longevity assurance. While reduced Activin within muscle autonomously retards functional aging of this tissue, these effects in muscle also reduce secretion of insulin-like peptides at a distance from the brain. Reduced insulin secretion from the brain may subsequently reinforce longevity assurance through decreased systemic insulin/IGF signaling. PMID:24244197

Specific serum and CSF microRNA profiles distinguish sporadic behavioural variant of frontotemporal dementia compared with Alzheimer patients and cognitively healthy controls

PubMed Central

Oberhauser, Felix; Kornhuber, Johannes; Wiltfang, Jens; Fassbender, Klaus; Schroeter, Matthias L.; Volk, Alexander E.; Diehl-Schmid, Janine; Prudlo, Johannes; Danek, Adrian; Landwehrmeyer, Bernhard; Lauer, Martin; Otto, Markus; Jahn, Holger

2018-01-01

Information on circulating miRNAs in frontotemporal lobar degeneration is very limited and conflicting results have complicated an interpretation in Alzheimer’s disease thus far. In the present study we I) collected samples from multiple clinical centers across Germany, II) defined 3 homogenous patient groups with high sample sizes (bvFTD n = 48, AD n = 48 and cognitively healthy controls n = 44), III) compared expression levels in both CSF and serum samples and IV) detected a limited set of miRNAs by using a MIQE compliant protocol based on SYBR-green miRCURY assays that have proven reliable to generate reproducible results. We included several quality controls that identified and reduced technical variation to increase the reliability of our data. We showed that the expression levels of circulating miRNAs measured in CSF did not correlate with levels in serum. Using cluster analysis we found expression pattern in serum that, in part, reflects the genomic organization and affiliation to a specific miRNA family and that were specifically altered in bvFTD, AD, and control groups. Applying factor analysis we identified a 3-factor model characterized by a miRNA signature that explained 80% of the variance classifying healthy controls with 97%, bvFTD with 77% and AD with 72% accuracy. MANOVA confirmed signals like miR-320a and miR-26b-5p at BH corrected significance that contributed most to discriminate bvFTD cases with 96% sensitivity and 90% specificity and AD cases with 89% sensitivity and specificity compared to healthy controls, respectively. Correlation analysis revealed that miRNAs from the 3-factor model also correlated with levels of protein biomarker amyloid-beta1-42 and phosphorylated neurofilament heavy chain, indicating their potential role in the monitoring of progressive neuronal degeneration. Our data show that miRNAs can be reproducibly measured in serum and CSF without pre-amplification and that serum includes higher expressed signals that demonstrate an overall better ability to classify bvFTD, AD and healthy controls compared to signals detected in CSF. PMID:29746584

Pre-announcement of symbiotic guests: transcriptional reprogramming by mycorrhizal lipochitooligosaccharides shows a strict co-dependency on the GRAS transcription factors NSP1 and RAM1.

PubMed

Hohnjec, Natalija; Czaja-Hasse, Lisa F; Hogekamp, Claudia; Küster, Helge

2015-11-23

More than 80 % of all terrestrial plant species establish an arbuscular mycorrhiza (AM) symbiosis with Glomeromycota fungi. This plant-microbe interaction primarily improves phosphate uptake, but also supports nitrogen, mineral, and water aquisition. During the pre-contact stage, the AM symbiosis is controled by an exchange of diffusible factors from either partner. Amongst others, fungal signals were identified as a mix of sulfated and non-sulfated lipochitooligosaccharides (LCOs), being structurally related to rhizobial nodulation (Nod)-factor LCOs that in legumes induce the formation of nitrogen-fixing root nodules. LCO signals are transduced via a common symbiotic signaling pathway (CSSP) that activates a group of GRAS transcription factors (TFs). Using complex gene expression fingerprints as molecular phenotypes, this study primarily intended to shed light on the importance of the GRAS TFs NSP1 and RAM1 for LCO-activated gene expression during pre-symbiotic signaling. We investigated the genome-wide transcriptional responses in 5 days old primary roots of the Medicago truncatula wild type and four symbiotic mutants to a 6 h challenge with LCO signals supplied at 10(-7/-8) M. We were able to show that during the pre-symbiotic stage, sulfated Myc-, non-sulfated Myc-, and Nod-LCO-activated gene expression almost exclusively depends on the LysM receptor kinase NFP and is largely controled by the CSSP, although responses independent of this pathway exist. Our results show that downstream of the CSSP, gene expression activation by Myc-LCOs supplied at 10(-7/-8) M strictly required both the GRAS transcription factors RAM1 and NSP1, whereas those genes either co- or specifically activated by Nod-LCOs displayed a preferential NSP1-dependency. RAM1, a central regulator of root colonization by AM fungi, controled genes activated by non-sulfated Myc-LCOs during the pre-symbiotic stage that are also up-regulated in areas with early physical contact, e.g. hyphopodia and infecting hyphae; linking responses to externally applied LCOs with early root colonization. Since both RAM1 and NSP1 were essential for the pre-symbiotic transcriptional reprogramming by Myc-LCOs, we propose that downstream of the CSSP, these GRAS transcription factors act synergistically in the transduction of those diffusible signals that pre-announce the presence of symbiotic fungi.

Enhanced urothelial expression of human chorionic gonadotropin beta (hCGβ) in bladder pain syndrome/interstitial cystitis (BPS/IC).

PubMed

Schwalenberg, Thilo; Stolzenburg, Jens-Uwe; Ho, Thi Phuc; Mallock, Tobias; Hartenstein, Siegurd; Alexander, Henry; Zimmermann, Gerolf; Hohenfellner, Rudolf; Denzinger, Stefan; Burger, Maximilian; Horn, Lars-Christian; Neuhaus, Jochen

2012-06-01

Bladder pain syndrome/interstitial cystitis (BPS/IC) is associated with urothelial lesions. Pathomechanisms of urothelial damage and factors for urothelial restoration are unknown. hCG is a factor for cellular differentiation, angiogenesis and immune competence of the endometrium during pregnancy. Clinical observations demonstrate improvement of BPS/IC symptoms during pregnancy or during infertility treatment with hCG. Our research aims were to examine the expression of hCG and luteinizing hormone receptor (LHR) in the urothelium of BPS/IC patients and compare the levels of hCGβ with healthy controls. Bladder biopsies of BPS/IC (CLSM: n = 10; qPCR: n = 15); Tumour-free control tissue from cystectomies (n = 12). hCGα, hCGβ and LHR expression were examined by confocal laser scanning microscopy (CLSM), and hCGβ expression was quantified. hCGβ5 and hCGβ7 mRNA splice variants were quantified in real-time polymerase chain reaction. We found constitutive expression of hCGα, hCGβ and LHR in healthy controls. HCGβ was significantly upregulated in BPS/IC patients in CLSM. PCR analysis revealed higher levels of hCGβ7 than hCGβ5 in controls and BPS/IC patients. The constitutive expression of hCG and LHR speaks in favour for a functional signalling in urothelial cells without any association with either pregnancy or tumour. We show for the first time that hCGβ is upregulated in BPS/IC urothelium and that hCGβ7 is the dominant splice variant in those cells. Our findings imply a major role of hCG for urothelial integrity and a disturbance of hCG signalling in case of BPS/IC. We conclude that hCG could gain therapeutical relevance in the future.

Neuronal expression of a thyroid hormone receptor α mutation alters mouse behaviour.

PubMed

Richard, S; Aguilera, N; Thévenet, M; Dkhissi-Benyahya, O; Flamant, F

2017-03-15

In humans, alterations in thyroid hormone signalling are associated with mood and anxiety disorders, but the neural mechanisms underlying such association are poorly understood. The present study investigates the involvement of neuronal thyroid hormone receptor α (TRα) in anxiety, using mouse genetics and Cre/loxP technology to specifically alter TRα signalling in neurons. We evaluated the behaviour of mice expressing a dominant negative, neuron-specific mutation of TRα (TRα AMI /Cre3 mice), using the elevated-plus maze, light-dark box and open-field tests. In a first experiment, mice were housed individually, and the behaviour of TRα AMI /Cre3 mice differed significantly from that of control littermates in these 3 tests, suggesting heightened anxiety. In a second experiment, designed to evaluate the robustness of the results with the same 3 tests, mice were housed in groups. In these conditions, the behaviour of TRα AMI /Cre3 mice differed from that of control littermates only in the light-dark box. Thus, TRα AMI /Cre3 mice appear to be more likely to develop anxiety under stressful housing conditions than control mice. These results suggest that in adult mice, thyroid hormone signalling in neurons, via TRα, is involved in the control of anxiety behaviour. Copyright © 2016 Elsevier B.V. All rights reserved.

Low-intensity vibrations normalize adipogenesis-induced morphological and molecular changes of adult mesenchymal stem cells.

PubMed

Baskan, Oznur; Mese, Gulistan; Ozcivici, Engin

2017-02-01

Bone marrow mesenchymal stem cells that are committed to adipogenesis were exposed daily to high-frequency low-intensity mechanical vibrations to understand molecular, morphological and ultrastructural adaptations to mechanical signals during adipogenesis. D1-ORL-UVA mouse bone marrow mesenchymal stem cells were cultured with either growth or adipogenic medium for 1 week. Low-intensity vibration signals (15 min/day, 90 Hz, 0.1 g) were applied to one group of adipogenic cells, while the other adipogenic group served as a sham control. Cellular viability, lipid accumulation, ultrastructure and morphology were determined with MTT, Oil-Red-O staining, phalloidin staining and atomic force microscopy. Semiquantitative reverse transcription polymerase chain reaction showed expression profile of the genes responsible for adipogenesis and ultrastructure of cells. Low-intensity vibration signals increased viability of the cells in adipogenic culture that was reduced significantly compared to quiescent controls. Low-intensity vibration signals also normalized the effects of adipogenic condition on cell morphology, including area, perimeter, circularization and actin cytoskeleton. Furthermore, low-intensity vibration signals reduced the expression of some adipogenic markers significantly. Mesenchymal stem cells are sensitive and responsive to mechanical loads, but debilitating conditions such as aging or obesity may steer mesenchymal stem cells toward adipogenesis. Here, daily application of low-intensity vibration signals partially neutralized the effects of adipogenic induction on mesenchymal stem cells, suggesting that these signals may provide an alternative and/or complementary option to reduce fat deposition.

The Influence of Facial Signals on the Automatic Imitation of Hand Actions

PubMed Central

Butler, Emily E.; Ward, Robert; Ramsey, Richard

2016-01-01

Imitation and facial signals are fundamental social cues that guide interactions with others, but little is known regarding the relationship between these behaviors. It is clear that during expression detection, we imitate observed expressions by engaging similar facial muscles. It is proposed that a cognitive system, which matches observed and performed actions, controls imitation and contributes to emotion understanding. However, there is little known regarding the consequences of recognizing affective states for other forms of imitation, which are not inherently tied to the observed emotion. The current study investigated the hypothesis that facial cue valence would modulate automatic imitation of hand actions. To test this hypothesis, we paired different types of facial cue with an automatic imitation task. Experiments 1 and 2 demonstrated that a smile prompted greater automatic imitation than angry and neutral expressions. Additionally, a meta-analysis of this and previous studies suggests that both happy and angry expressions increase imitation compared to neutral expressions. By contrast, Experiments 3 and 4 demonstrated that invariant facial cues, which signal trait-levels of agreeableness, had no impact on imitation. Despite readily identifying trait-based facial signals, levels of agreeableness did not differentially modulate automatic imitation. Further, a Bayesian analysis showed that the null effect was between 2 and 5 times more likely than the experimental effect. Therefore, we show that imitation systems are more sensitive to prosocial facial signals that indicate “in the moment” states than enduring traits. These data support the view that a smile primes multiple forms of imitation including the copying actions that are not inherently affective. The influence of expression detection on wider forms of imitation may contribute to facilitating interactions between individuals, such as building rapport and affiliation. PMID:27833573

The N-terminal region of the dopamine D2 receptor, a rhodopsin-like GPCR, regulates correct integration into the plasma membrane and endocytic routes

PubMed Central

Cho, DI; Min, C; Jung, KS; Cheong, SY; Zheng, M; Cheong, SJ; Oak, MH; Cheong, JH; Lee, BK; Kim, KM

2012-01-01

BACKGROUND AND PURPOSE Functional roles of the N-terminal region of rhodopsin-like GPCR family remain unclear. Using dopamine D2 and D3 receptors as a model system, we probed the roles of the N-terminal region in the signalling, intracellular trafficking of receptor proteins, and explored the critical factors that determine the functionality of the N-terminal region. EXPERIMENTAL APPROACH The N-terminal region of the D2 receptor was gradually shortened or switched with that of the D3 receptor or a non-specific sequence (FLAG), or potential N-terminal glycosylation sites were mutated. Effects of these manipulations on surface expression, internalization, post-endocytic behaviours and signalling were determined. KEY RESULTS Shortening the N-terminal region of the D2 receptor enhanced receptor internalization and impaired surface expression and signalling; ligand binding, desensitization and down-regulation were not affected but their association with a particular microdomain, caveolae, was disrupted. Replacement of critical residues within the N-terminal region with the FLAG epitope failed to restore surface expression but partially restored the altered internalization and signalling. When the N-terminal regions were switched between D2 and D3 receptors, cell surface expression pattern of each receptor was switched. Mutations of potential N-terminal glycosylation sites inhibited surface expression but enhanced internalization of D2 receptors. CONCLUSIONS AND IMPLICATIONS Shortening of N-terminus or mutation of glycosylation sites located within the N-terminus enhanced receptor internalization but impaired the surface expression of D2 receptors. The N-terminal region of the D2 receptor, in a sequence-specific manner, controls the receptor's conformation and integration into the plasma membrane, which determine its subcellular localization, intracellular trafficking and signalling properties. PMID:22117524

The Influence of Facial Signals on the Automatic Imitation of Hand Actions.

PubMed

Butler, Emily E; Ward, Robert; Ramsey, Richard

2016-01-01

Imitation and facial signals are fundamental social cues that guide interactions with others, but little is known regarding the relationship between these behaviors. It is clear that during expression detection, we imitate observed expressions by engaging similar facial muscles. It is proposed that a cognitive system, which matches observed and performed actions, controls imitation and contributes to emotion understanding. However, there is little known regarding the consequences of recognizing affective states for other forms of imitation, which are not inherently tied to the observed emotion. The current study investigated the hypothesis that facial cue valence would modulate automatic imitation of hand actions. To test this hypothesis, we paired different types of facial cue with an automatic imitation task. Experiments 1 and 2 demonstrated that a smile prompted greater automatic imitation than angry and neutral expressions. Additionally, a meta-analysis of this and previous studies suggests that both happy and angry expressions increase imitation compared to neutral expressions. By contrast, Experiments 3 and 4 demonstrated that invariant facial cues, which signal trait-levels of agreeableness, had no impact on imitation. Despite readily identifying trait-based facial signals, levels of agreeableness did not differentially modulate automatic imitation. Further, a Bayesian analysis showed that the null effect was between 2 and 5 times more likely than the experimental effect. Therefore, we show that imitation systems are more sensitive to prosocial facial signals that indicate "in the moment" states than enduring traits. These data support the view that a smile primes multiple forms of imitation including the copying actions that are not inherently affective. The influence of expression detection on wider forms of imitation may contribute to facilitating interactions between individuals, such as building rapport and affiliation.

Competing signals drive telencephalon diversity.

PubMed

Sylvester, J B; Rich, C A; Yi, C; Peres, J N; Houart, C; Streelman, J T

2013-01-01

The telencephalon is the most complex brain region, controlling communication, emotion, movement and memory. Its adult derivatives develop from the dorsal pallium and ventral subpallium. Despite knowledge of genes required in these territories, we do not understand how evolution has shaped telencephalon diversity. Here, using rock- and sand-dwelling cichlid fishes from Lake Malawi, we demonstrate that differences in strength and timing of opposing Hedgehog and Wingless signals establish evolutionary divergence in dorsal-ventral telencephalon patterning. Rock dwellers exhibit early, extensive Hedgehog activity in the ventral forebrain resulting in expression of foxg1 before dorsal Wingless signals, and a larger subpallium. Sand dwellers show rapid deployment of Wingless, later foxg1 expression and a larger pallium. Manipulation of the Hedgehog and Wingless pathways in cichlid and zebrafish embryos is sufficient to mimic differences between rock- versus sand-dweller brains. Our data suggest that competing ventral Hedgehog and dorsal Wingless signals mediate evolutionary diversification of the telencephalon.

Immune signaling by RIG-I-like receptors

PubMed Central

Loo, Yueh-Ming; Gale, Michael

2011-01-01

The RIG-I-like receptors (RLRs) RIG-I, MDA5, and LGP2 play a major role in pathogen sensing of RNA virus infection to initiate and modulate antiviral immunity. The RLRs detect viral RNA ligands or processed self RNA in the cytoplasm to triggers innate immunity and inflammation and to impart gene expression that serves to control infection. Importantly, RLRs cooperate in signaling crosstalk networks with Toll-like receptors and other factors to impart innate immunity and to modulate the adaptive immune response. RLR regulation occurs at a variety of levels ranging from autoregulation to ligand and co-factor interactions and post-translational modifications. Abberant RLR signaling or dysregulation of RLR expression is now implicated in the development of autoimmune diseases. Understanding the processes of RLR signaling and response will provide insights to guide RLR-targeted therapeutics for antiviral and immune modifying applications. PMID:21616437

p38 MAP kinase is required for Wnt3a-mediated osterix expression independently of Wnt-LRP5/6-GSK3β signaling axis in dental follicle cells

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

Sakisaka, Yukihiko; Kanaya, Sousuke; Liason Center for Innovative Dentistry, Tohoku University Graduate School of Dentistry, Sendai 980-8575

Wnt3a is a secreted glycoprotein that activates the glycogen synthase kinase-3β (GSK3β)/β-catenin signaling pathway through low-density-lipoprotein receptor-related protein (LRP)5/6 co-receptors. Wnt3a has been implicated in periodontal development and homeostasis, as well as in cementum formation. Recently, we have reported that Wnt3a increases alkaline phosphatase expression through the induction of osterix (Osx) expression in dental follicle cells, a precursor of cementoblasts. However, the molecular mechanism by which Wnt3a induces Osx expression is still unknown. In this study, we show that Wnt3a-induced Osx expression was inhibited in the presence of p38 mitogen-activated protein kinase (MAPK) inhibitors (SB203580 and SB202190) at gene andmore » protein levels, as assessed by real-time PCR and immunocytohistochemistry, respectively. Pretreatment of cells with Dickkopf-1, a potent canonical Wnt antagonist binding to LRP5/6 co-receptors, did not influence Wnt3a-mediated p38 MAPK phosphorylation, suggesting that Wnt3a activates p38 MAPK through LRP5/6-independent signaling. On the other hand, pretreatment with p38 MAPK inhibitors had no effects on the phosphorylated status of GSK3β and β-catenin as well as β-catenin nuclear translocation, but inhibited Wnt3a-mediated β-catenin transcriptional activity. These findings suggest that p38 MAPK modulates canonical Wnt signaling at the β-catenin transcriptional level without any crosstalk with the Wnt3a-mediated LRP5/6-GSK3β signaling axis and subsequent β-catenin nuclear translocation. These findings expand our knowledge of the mechanisms controlling periodontal development and regeneration. - Highlights: • Wnt3a induces Osx expression via p38 MAPK signaling in dental follicle cells. • p38 MAPK has no crosstalk with Wnt3a-mediated LRP5/6 and GSK3β signaling. • p38 MAPK is required for Wnt signaling at the β-catenin transcriptional level.« less

Inhibition of p38 mitogen-activated protein kinase impairs influenza virus-induced primary and secondary host gene responses and protects mice from lethal H5N1 infection.

PubMed

Börgeling, Yvonne; Schmolke, Mirco; Viemann, Dorothee; Nordhoff, Carolin; Roth, Johannes; Ludwig, Stephan

2014-01-03

Highly pathogenic avian influenza viruses (HPAIV) induce severe inflammation in poultry and men. One characteristic of HPAIV infections is the induction of a cytokine burst that strongly contributes to viral pathogenicity. This cell-intrinsic hypercytokinemia seems to involve hyperinduction of p38 mitogen-activated protein kinase. Here we investigate the role of p38 MAPK signaling in the antiviral response against HPAIV in mice as well as in human endothelial cells, the latter being a primary source of cytokines during systemic infections. Global gene expression profiling of HPAIV-infected endothelial cells in the presence of the p38-specific inhibitor SB 202190 revealed that inhibition of p38 MAPK leads to reduced expression of IFNβ and other cytokines after H5N1 and H7N7 infection. More than 90% of all virus-induced genes were either partially or fully dependent on p38 signaling. Moreover, promoter analysis confirmed a direct impact of p38 on the IFNβ promoter activity. Furthermore, upon treatment with IFN or conditioned media from HPAIV-infected cells, p38 controls interferon-stimulated gene expression by coregulating STAT1 by phosphorylation at serine 727. In vivo inhibition of p38 MAPK greatly diminishes virus-induced cytokine expression concomitant with reduced viral titers, thereby protecting mice from lethal infection. These observations show that p38 MAPK acts on two levels of the antiviral IFN response. Initially the kinase regulates IFN induction and, at a later stage, p38 controls IFN signaling and thereby expression of IFN-stimulated genes. Thus, inhibition of MAP kinase p38 may be an antiviral strategy that protects mice from lethal influenza by suppressing excessive cytokine expression.

Association of microRNA 146 with middle ear hyperplasia in pediatric otitis media.

PubMed

Samuels, Tina L; Yan, Justin; Khampang, Pawjai; MacKinnon, Alexander; Hong, Wenzhou; Johnston, Nikki; Kerschner, Joseph E

2016-09-01

Toll-like receptor signaling activated by bacterial otitis media pathogens in the middle ear has been shown to play a key role in OM susceptibility, pathogenesis and recovery. Recent studies implicate microRNA 146 (miR-146) in regulation of inflammation via negative feedback of toll-like receptor signaling (TLR) in a wide variety of tissues, however its involvement in otitis media is unknown. Human middle ear epithelial cells were stimulated with proinflammatory cytokines, interleukin 1 beta or tumor necrosis factor alpha, for two to twenty-four hours. Middle ear biopsies were collected from children with otitis media with effusion (n = 20), recurrent otitis media (n = 9), and control subjects undergoing cochlear implantation (n = 10). miR-146a, miR-146b expression was assayed by quantitative PCR (qPCR). Expression of miR-146 targets involved in TLR signaling, IRAK1 and TRAF6, was assayed by qPCR in middle ear biopsies. Middle ear biopsies were cryosectioned and epithelial thickness measured by a certified pathologist. Proinflammatory cytokines induced expression of miR-146 in middle ear epithelial cells in vitro. Middle ear miR-146a and miR-146b expression was elevated in otitis media patients relative to control subjects and correlated with middle ear epithelial thickness. A trend towards inverse correlation was observed between miR-146 and TRAF6 expression in the clinical population. This report is the first to assess miRNA expression in a clinical population with OM. Findings herein suggest miR-146 may play a role in OM. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The effects of pleiotrophin in proliferative vitreoretinopathy.

PubMed

Ding, Xue; Bai, Yujing; Zhu, Xuemei; Li, Tianqi; Jin, Enzhong; Huang, Lvzhen; Yu, Wenzhen; Zhao, Mingwei

2017-05-01

The purpose of our study was to investigate the effects of pleiotrophin (PTN) in proliferative vitreoretinopathy (PVR) both in vitro and in vivo. Immunofluorescence was used to observe the PTN expression in periretinal membrane samples from patients with PVR and controls. ARPE-19 cells were exposed to TGF-β1. The epithelial-to-mesenchymal transition (EMT) of the ARPE-19 cells was confirmed by observed morphological changes and the increased expression of α-SMA and fibronectin at both the mRNA and protein levels. We used specific small interfering (si)RNA to knock down the expression of PTN. The subsequent effects of PTN inhibition were assessed with regard to the EMT, migration, proliferation, cytoskeletal arrangement, TGF-β signaling, PTN signaling, integral tight junction protein expression (e.g., claudin-1 and occludin), and p38 MAPK and p-p38 MAPK levels. Additionally, a PVR rat model was established by the intravitreal injection of ARPE-19 cells transfected with PTN-siRNA and was evaluated accordingly. PTN was highly expressed in PVR membranes compared to controls. PTN knockdown attenuated the TGF-β1-induced migration, proliferation, cytoskeletal rearrangement, and expression of EMT markers such as α-SMA and fibronectin in the ARPE-19 cells, and these effects may have been mediated through p38 MAPK signaling pathway activation. PTN silencing inhibited the up-regulation of claudin-1 and occludin stimulated by TGF-β1, and PTN knockdown inhibited the proliferative aspects of severe PVR in vivo. PTN is involved in the process of EMT induced by TGF-β1 in human ARPE-19 cells in vitro, and PTN knockdown attenuated the progression of experimental PVR in vivo. These findings provide new insights into the pathogenesis of PVR.

Cell surface expression of channel catfish leukocyte immune-type receptors (IpLITRs) and recruitment of both Src homology 2 domain-containing protein tyrosine phosphatase (SHP)-1 and SHP-2.

PubMed

Montgomery, Benjamin C S; Mewes, Jacqueline; Davidson, Chelsea; Burshtyn, Deborah N; Stafford, James L

2009-04-01

Channel catfish leukocyte immune-type receptors (IpLITRs) are immunoglobulin superfamily (IgSF) members believed to play a role in the control and coordination of cellular immune responses in teleost. Putative stimulatory and inhibitory IpLITRs are co-expressed by different types of catfish immune cells (e.g. NK cells, T cells, B cells, and macrophages) but their signaling potential has not been determined. Following cationic polymer-mediated transfections into human cell lines we examined the surface expression, tyrosine phosphorylation, and phosphatase recruitment potential of two types of putative inhibitory IpLITRs using 'chimeric' expression constructs and an epitope-tagged 'native' IpLITR. We also cloned and expressed the teleost Src homology 2 domain-containing protein tyrosine phosphatases (SHP)-1 and SHP-2 and examined their expression in adult tissues and developing zebrafish embryos. Co-immunoprecipitation experiments support the inhibitory signaling potential of distinct IpLITR-types that bound both SHP-1 and SHP-2 following the phosphorylation of tyrosine residues within their cytoplasmic tail (CYT) regions. Phosphatase recruitment by IpLITRs represents an important first step in understanding their influence on immune cell effector functions and suggests that certain inhibitory signaling pathways are conserved among vertebrates.

The Notch ligand Delta-like 4 negatively regulates endothelial tip cell formation and vessel branching

PubMed Central

Suchting, Steven; Freitas, Catarina; le Noble, Ferdinand; Benedito, Rui; Bréant, Christiane; Duarte, Antonio; Eichmann, Anne

2007-01-01

Delta-like 4 (Dll4) is a transmembrane ligand for Notch receptors that is expressed in arterial blood vessels and sprouting endothelial cells. Here we show that Dll4 regulates vessel branching during development by inhibiting endothelial tip cell formation. Heterozygous deletion of dll4 or pharmacological inhibition of Notch signaling using γ-secretase inhibitor revealed a striking vascular phenotype, with greatly increased numbers of filopodia-extending endothelial tip cells and increased expression of tip cell marker genes compared with controls. Filopodia extension in dll4+/− retinal vessels required the vascular growth factor VEGF and was inhibited when VEGF signaling was blocked. Although VEGF expression was not significantly altered in dll4+/− retinas, dll4+/− vessels showed increased expression of VEGF receptor 2 and decreased expression of VEGF receptor 1 compared with wild-type, suggesting they could be more responsive to VEGF stimulation. In addition, expression of dll4 in wild-type tip cells was itself decreased when VEGF signaling was blocked, indicating that dll4 may act downstream of VEGF as a “brake” on VEGF-mediated angiogenic sprouting. Taken together, these data reveal Dll4 as a negative regulator of vascular sprouting and vessel branching that is required for normal vascular network formation during development. PMID:17296941

The Notch ligand Delta-like 4 negatively regulates endothelial tip cell formation and vessel branching.

PubMed

Suchting, Steven; Freitas, Catarina; le Noble, Ferdinand; Benedito, Rui; Bréant, Christiane; Duarte, Antonio; Eichmann, Anne

2007-02-27

Delta-like 4 (Dll4) is a transmembrane ligand for Notch receptors that is expressed in arterial blood vessels and sprouting endothelial cells. Here we show that Dll4 regulates vessel branching during development by inhibiting endothelial tip cell formation. Heterozygous deletion of dll4 or pharmacological inhibition of Notch signaling using gamma-secretase inhibitor revealed a striking vascular phenotype, with greatly increased numbers of filopodia-extending endothelial tip cells and increased expression of tip cell marker genes compared with controls. Filopodia extension in dll4(+/-) retinal vessels required the vascular growth factor VEGF and was inhibited when VEGF signaling was blocked. Although VEGF expression was not significantly altered in dll4(+/-) retinas, dll4(+/-) vessels showed increased expression of VEGF receptor 2 and decreased expression of VEGF receptor 1 compared with wild-type, suggesting they could be more responsive to VEGF stimulation. In addition, expression of dll4 in wild-type tip cells was itself decreased when VEGF signaling was blocked, indicating that dll4 may act downstream of VEGF as a "brake" on VEGF-mediated angiogenic sprouting. Taken together, these data reveal Dll4 as a negative regulator of vascular sprouting and vessel branching that is required for normal vascular network formation during development.

High-throughput microfluidics to control and measure signaling dynamics in single yeast cells

PubMed Central

Hansen, Anders S.; Hao, Nan; O'Shea, Erin K.

2015-01-01

Microfluidics coupled to quantitative time-lapse fluorescence microscopy is transforming our ability to control, measure, and understand signaling dynamics in single living cells. Here we describe a pipeline that incorporates multiplexed microfluidic cell culture, automated programmable fluid handling for cell perturbation, quantitative time-lapse microscopy, and computational analysis of time-lapse movies. We illustrate how this setup can be used to control the nuclear localization of the budding yeast transcription factor Msn2. Using this protocol, we generate oscillations of Msn2 localization and measure the dynamic gene expression response of individual genes in single cells. The protocol allows a single researcher to perform up to 20 different experiments in a single day, whilst collecting data for thousands of single cells. Compared to other protocols, the present protocol is relatively easy to adopt and higher-throughput. The protocol can be widely used to control and monitor single-cell signaling dynamics in other signal transduction systems in microorganisms. PMID:26158443

FGF signaling supports Drosophila fertility by regulating development of ovarian muscle tissues

PubMed Central

Irizarry, Jihyun; Stathopoulos, Angelike

2015-01-01

The thisbe (ths) gene encodes a Drosophila fibroblast growth factor (FGF), and mutant females are viable but sterile suggesting a link between FGF signaling and fertility. Ovaries exhibit abnormal morphology including lack of epithelial sheaths, muscle tissues that surround ovarioles. Here we investigated how FGF influences Drosophila ovary morphogenesis and identified several roles. Heartless (Htl) FGF receptor was found expressed within somatic cells at the larval and pupal stages, and phenotypes were uncovered using RNAi. Differentiation of terminal filament cells was affected, but this effect did not alter ovariole number. In addition, proliferation of epithelial sheath progenitors, the apical cells, was decreased in both htl and ths mutants, while ectopic expression of the Ths ligand led to these cells’ over-proliferation suggesting that FGF signaling supports ovarian muscle sheath formation by controlling apical cell number in the developing gonad. Additionally, live imaging of adult ovaries was used to show that htl RNAi mutants, hypomorphic mutants in which epithelial sheaths are present, exhibit abnormal muscle contractions. Collectively, our results demonstrate that proper formation of ovarian muscle tissues is regulated by FGF signaling in the larval and pupal stages through control of apical cell proliferation and is required to support fertility. PMID:25958090

ROBUSTNESS OF SIGNALING GRADIENT IN DROSOPHILA WING IMAGINAL DISC

PubMed Central

Lei, Jinzhi; Wan, Frederic Y. M.; Lander, Arthur D.; Nie, Qing

2012-01-01

Quasi-stable gradients of signaling protein molecules (known as morphogens or ligands) bound to cell receptors are known to be responsible for differential cell signaling and gene expressions. From these follow different stable cell fates and visually patterned tissues in biological development. Recent studies have shown that the relevant basic biological processes yield gradients that are sensitive to small changes in system characteristics (such as expression level of morphogens or receptors) or environmental conditions (such as temperature changes). Additional biological activities must play an important role in the high level of robustness observed in embryonic patterning for example. It is natural to attribute observed robustness to various type of feedback control mechanisms. However, our own simulation studies have shown that feedback control is neither necessary nor sufficient for robustness of the morphogen decapentaplegic (Dpp) gradient in wing imaginal disc of Drosophilas. Furthermore, robustness can be achieved by substantial binding of the signaling morphogen Dpp with nonsignaling cell surface bound molecules (such as heparan sulfate proteoglygans) and degrading the resulting complexes at a sufficiently rapid rate. The present work provides a theoretical basis for the results of our numerical simulation studies. PMID:24098092

Rho-associated Kinase Connects a Cell Cycle-controlling Anchorage Signal to the Mammalian Target of Rapamycin Pathway*

PubMed Central

Park, Jung-ha; Arakawa-Takeuchi, Shiho; Jinno, Shigeki; Okayama, Hiroto

2011-01-01

When deprived of anchorage to the extracellular matrix, fibroblasts arrest in G1 phase at least in part due to inactivation of G1 cyclin-dependent kinases. Despite great effort, how anchorage signals control the G1-S transition of fibroblasts remains highly elusive. We recently found that the mammalian target of rapamycin (mTOR) cascade might convey an anchorage signal that regulates S phase entry. Here, we show that Rho-associated kinase connects this signal to the TSC1/TSC2-RHEB-mTOR pathway. Expression of a constitutively active form of ROCK1 suppressed all of the anchorage deprivation effects suppressible by tsc2 mutation in rat embryonic fibroblasts. TSC2 contains one evolutionarily conserved ROCK target-like sequence, and an alanine substitution for Thr1203 in this sequence severely impaired the ability of ROCK1 to counteract the anchorage loss-imposed down-regulation of both G1 cell cycle factors and mTORC1 activity. Moreover, TSC2 Thr1203 underwent ROCK-dependent phosphorylation in vivo and could be phosphorylated by bacterially expressed active ROCK1 in vitro, providing biochemical evidence for a direct physical interaction between ROCK and TSC2. PMID:21561859

Identification and characterization of lbpA, an indigoidine biosynthetic gene in the γ-butyrolactone signaling system of Streptomyces lavendulae FRI-5.

PubMed

Pait, Ivy Grace Umadhay; Kitani, Shigeru; Kurniawan, Yohanes Novi; Asa, Maeda; Iwai, Takashi; Ikeda, Haruo; Nihira, Takuya

2017-10-01

Streptomyces lavendulae FRI-5 produces the blue pigment indigoidine and other secondary metabolites (d-cycloserine and nucleoside antibiotics). The production of these useful compounds is controlled by a signaling cascade mediated by the γ-butyrolactone autoregulator IM-2. Previously we revealed that the far regulatory island includes the IM-2 receptor, the IM-2 biosynthetic enzyme, and several transcriptional regulators, and that it contributes to the regulation of indigoidine production in response to the signaling molecule. Here, we found that the vicinity of the far regulatory island includes the putative gene cluster for the biosynthesis of indigoidine and unidentified compounds, and demonstrated that the expression of the gene cluster is under the control of the IM-2 regulatory system. Heterologous expression of lbpA, encoding a plausible nonribosomal peptide synthetase, in the versatile model host Streptomyces avermitilis SUKA22 led to indigoidine production, which was enhanced dramatically by feeding of the indigoidine precursor l-glutamine. These results confirmed that LbpA is an indigoidine biosynthetic enzyme in the IM-2 signaling cascade. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Death receptor Fas (CD95) signaling in the central nervous system: tuning neuroplasticity?

PubMed

Reich, Arno; Spering, Christopher; Schulz, Jörg B

2008-09-01

For over a decade, neuroscientific research has focused on processes of apoptosis and its contribution to the pathophysiology of neurological diseases. In the central nervous system, the degree of intrinsic mitochondrial-mediated apoptotic signaling expresses a cell's individual metabolic stress, whereas activation of the extrinsic death receptor-induced cascade is regarded as a sign of imbalanced cellular networks. Under physiological conditions, most neurons possess death receptors without being sensitive to receptor-mediated apoptosis. This paradox raises two questions: what is the evolutionary advantage of expressing potentially harmful proteins? How is their signaling controlled? This review summarizes the functional relevance of FasL-Fas signaling--a quintessential death ligand/receptor system--in different neurological disease models ranging from traumatic, inflammatory and ischemic to neurodegenerative processes. Furthermore, it outlines alternative non-apoptotic Fas signaling, shedding new light on its neuroplastic capacity. Finally, receptor-proximal regulatory proteins are introduced and identified as potential protagonists of disease-modifying neurological therapies.

Domestication-driven Gossypium profilin 1 (GhPRF1) gene transduces early flowering phenotype in tobacco by spatial alteration of apical/floral-meristem related gene expression.

PubMed

Pandey, Dhananjay K; Chaudhary, Bhupendra

2016-05-13

Plant profilin genes encode core cell-wall structural proteins and are evidenced for their up-regulation under cotton domestication. Notwithstanding striking discoveries in the genetics of cell-wall organization in plants, little is explicit about the manner in which profilin-mediated molecular interplay and corresponding networks are altered, especially during cellular signalling of apical meristem determinacy and flower development. Here we show that the ectopic expression of GhPRF1 gene in tobacco resulted in the hyperactivation of apical meristem and early flowering phenotype with increased flower number in comparison to the control plants. Spatial expression alteration in CLV1, a key meristem-determinacy gene, is induced by the GhPRF1 overexpression in a WUS-dependent manner and mediates cell signalling to promote flowering. But no such expression alterations are recorded in the GhPRF1-RNAi lines. The GhPRF1 transduces key positive flowering regulator AP1 gene via coordinated expression of FT4, SOC1, FLC1 and FT1 genes involved in the apical-to-floral meristem signalling cascade which is consistent with our in silico profilin interaction data. Remarkably, these positive and negative flowering regulators are spatially controlled by the Actin-Related Protein (ARP) genes, specifically ARP4 and ARP6 in proximate association with profilins. This study provides a novel and systematic link between GhPRF1 gene expression and the flower primordium initiation via up-regulation of the ARP genes, and an insight into the functional characterization of GhPRF1 gene acting upstream to the flowering mechanism. Also, the transgenic plants expressing GhPRF1 gene show an increase in the plant height, internode length, leaf size and plant vigor. Overexpression of GhPRF1 gene induced early and increased flowering in tobacco with enhanced plant vigor. During apical meristem determinacy and flower development, the GhPRF1 gene directly influences key flowering regulators through ARP-genes, indicating for its role upstream in the apical-to-floral meristem signalling cascade.

Leptin Signaling Is Not Required for Anorexigenic Estradiol Effects in Female Mice.

PubMed

Kim, Joon S; Rizwan, Mohammed Z; Clegg, Deborah J; Anderson, Greg M

2016-05-01

Estradiol and leptin are critical hormones in the regulation of body weight. The aim of this study was to determine whether this cross talk between leptin receptor (LepRb) and estrogen receptor-α (ERα) signaling is critical for estradiol's anorexigenic effects. Leprb-Cre mice were crossed with Cre-dependent Tau-green fluorescent protein (GFP) reporter, Stat3-flox or Erα-flox mice to generate female mice with GFP expression, signal transducer and activator of transcription 3 (STAT3) knockout (KO), or ERα KO, specifically in LepRb-expressing cells. The proportion of Leprb-GFP cells colocalizing ERα was high (∼80%) in the preoptic area but low (∼10%) in the mediobasal hypothalamus, suggesting that intracellular cross talk between these receptors is minimal for metabolic regulation. To test whether estradiol enhanced arcuate leptin sensitivity, ovarectomized mice received varying levels of estradiol replacement. Increasing estrogenic states did not increase the degree of leptin-induced STAT3 phosphorylation. LepRb-specific STAT3 KO mice and controls were ovarectomized and given either chronic estradiol or vehicle treatment to test whether STAT3 is required for estrogen-induced body weight suppression. Both groups of estradiol-treated mice showed an equivalent reduction in body weight and fat content compared with vehicle controls. Finally, mice lacking ERα specifically in LepRb-expressing neurons also showed no increase in body weight or impairments in metabolic function compared with controls, indicating that estradiol acts independently of leptin-responsive cells to regulate body weight. However, fecundity was impaired in in Leprb-ERα KO females. Contrary to the current dogma, we report that estradiol has minimal direct actions on LepRb cells in the mediodasal hypothalamus and that its anorexigenic effects can occur entirely independently of LepRb-STAT3 signaling in female mice.

INHIBITION OF ERN1 SIGNALING ENZYME AFFECTS HYPOXIC REGULATION OF THE EXPRESSION OF E2F8, EPAS1, HOXC6, ATF3, TBX3 AND FOXF1 GENES IN U87 GLIOMA CELLS.

PubMed

Minchenko, O H; Tsymbal, D O; Minchenko, D O; Kovalevska, O V; Karbovskyi, L L; Bikfalvi, A

2015-01-01

Hypoxia as well as the endoplasmic reticulum stress are important factors of malignant tumor growth and control of the expression of genes, which regulate numerous metabolic processes and cell proliferation. Furthermore, blockade of ERN1 (endoplasmic reticulum to nucleus 1) suppresses cell proliferation and tumor growth. We studied the effect of hypoxia on the expression of genes encoding the transcription factors such as E2F8 (E2F transcription factor 8), EPAS1 (endothelial PAS domain protein 1), TBX3 (T-box 3), ATF3 (activating transcription factor 3), FOXF1 (forkhead box F), and HOXC6 (homeobox C6) in U87 glioma cells with and without ERN1 signaling enzyme function. We have established that hypoxia enhances the expression of HOXC6, E2F8, ATF3, and EPAS1 genes but does not change TBX3 and FOXF1 gene expression in glioma cells with ERNI function. At the same time, the expression level of all studied genes is strongly decreased, except for TBX3 gene, in glioma cells without ERN1 function. Moreover, the inhibition of ERN1 signaling enzyme function significantly modifies the effect of hypoxia on the expression of these transcription factor genes. removes or introduces this regulation as well as changes a direction or magnitude of hypoxic regulation. Present study demonstrates that fine-tuning of the expression of proliferation related genes depends upon hypoxia and ERN1-mediated endoplasmic reticulum stress signaling and correlates with slower proliferation rate of glioma cells without ERN1 function.

Protein expression vector and secretion signal peptide optimization to drive the production, secretion, and functional expression of the bacteriocin enterocin A in lactic acid bacteria.

PubMed

Borrero, Juan; Jiménez, Juan J; Gútiez, Loreto; Herranz, Carmen; Cintas, Luis M; Hernández, Pablo E

2011-10-20

Replacement of the leader sequence (LS) of the bacteriocin enterocin A (LS(entA)) by the signal peptides (SP) of the protein Usp45 (SP(usp45)), and the bacteriocins enterocin P (SP(entP)), and hiracin JM79 (SP(hirJM79)) permits the production, secretion, and functional expression of EntA by different lactic acid bacteria (LAB). Chimeric genes encoding the SP(usp45), the SP(entP), and the SP(hirJM79) fused to mature EntA plus the EntA immunity genes (entA+entiA) were cloned into the expression vectors pNZ8048 and pMSP3545, under control of the inducible P(nisA) promoter, and in pMG36c, under control of the constitutive P(32) promoter. The amount, antimicrobial activity, and specific antimicrobial activity of the EntA produced by the recombinant Lactococcus lactis, Enterococcus faecium, E. faecalis, Lactobacillus sakei and Pediococcus acidilactici hosts varied depending on the signal peptide, the expression vector, and the host strain. However, the antimicrobial activity and the specific antimicrobial activity of the EntA produced by most of the LAB transformants was lower than expected from their production. The supernatants of the recombinant L. lactis NZ9000 (pNZUAI) and L. lactis NZ9000 (pNZHAI), overproducers of EntA, showed a 1.2- to 5.1-fold higher antimicrobial activity than that of the natural producer E. faecium T136 against different Listeria spp. Copyright © 2011 Elsevier B.V. All rights reserved.

The thrombopoietin/MPL/Bcl-xL pathway is essential for survival and self-renewal in human preleukemia induced by AML1-ETO

PubMed Central

Chou, Fu-Sheng; Griesinger, Andrea; Wunderlich, Mark; Lin, Shan; Link, Kevin A.; Shrestha, Mahesh; Goyama, Susumu; Mizukawa, Benjamin; Shen, Shuhong; Marcucci, Guido

2012-01-01

AML1-ETO (AE) is a fusion product of translocation (8;21) that accounts for 40% of M2 type acute myeloid leukemia (AML). In addition to its role in promoting preleukemic hematopoietic cell self-renewal, AE represses DNA repair genes, which leads to DNA damage and increased mutation frequency. Although this latter function may promote leukemogenesis, concurrent p53 activation also leads to an increased baseline apoptotic rate. It is unclear how AE expression is able to counterbalance this intrinsic apoptotic conditioning by p53 to promote survival and self-renewal. In this report, we show that Bcl-xL is up-regulated in AE cells and plays an essential role in their survival and self-renewal. Further investigation revealed that Bcl-xL expression is regulated by thrombopoietin (THPO)/MPL-signaling induced by AE expression. THPO/MPL-signaling also controls cell cycle reentry and mediates AE-induced self-renewal. Analysis of primary AML patient samples revealed a correlation between MPL and Bcl-xL expression specifically in t(8;21) blasts. Taken together, we propose that survival signaling through Bcl-xL is a critical and intrinsic component of a broader self-renewal signaling pathway downstream of AML1-ETO–induced MPL. PMID:22337712

Indirect immobilized Jagged1 suppresses cell cycle progression and induces odonto/osteogenic differentiation in human dental pulp cells.

PubMed

Manokawinchoke, Jeeranan; Nattasit, Praphawi; Thongngam, Tanutchaporn; Pavasant, Prasit; Tompkins, Kevin A; Egusa, Hiroshi; Osathanon, Thanaphum

2017-08-31

Notch signaling regulates diverse biological processes in dental pulp tissue. The present study investigated the response of human dental pulp cells (hDPs) to the indirect immobilized Notch ligand Jagged1 in vitro. The indirect immobilized Jagged1 effectively activated Notch signaling in hDPs as confirmed by the upregulation of HES1 and HEY1 expression. Differential gene expression profiling using an RNA sequencing technique revealed that the indirect immobilized Jagged1 upregulated genes were mainly involved in extracellular matrix organization, disease, and signal transduction. Downregulated genes predominantly participated in the cell cycle, DNA replication, and DNA repair. Indirect immobilized Jagged1 significantly reduced cell proliferation, colony forming unit ability, and the number of cells in S phase. Jagged1 treated hDPs exhibited significantly higher ALP enzymatic activity, osteogenic marker gene expression, and mineralization compared with control. Pretreatment with a γ-secretase inhibitor attenuated the Jagged1-induced ALP activity and mineral deposition. NOTCH2 shRNA reduced the Jagged1-induced osteogenic marker gene expression, ALP enzymatic activity, and mineral deposition. In conclusion, indirect immobilized Jagged1 suppresses cell cycle progression and induces the odonto/osteogenic differentiation of hDPs via the canonical Notch signaling pathway.

The scaffolding and signaling functions of a localization factor impact polar development

PubMed Central

Curtis, Patrick D.; Quardokus, Ellen M.; Lawler, Melanie L.; Guo, Xiaoyun; Klein, David; Chen, Joseph C.; Arnold, Randy J.; Brun, Yves V.

2012-01-01

SUMMARY In the differentiating alphaproteobacterium Caulobacter crescentus, organelle synthesis at cell poles is critical to forming different progeny after cell division. Coordination of polar organelle synthesis, including pili and holdfast, and flagellum ejection, is mediated in part by the scaffolding protein PodJ. At the time of cell division, PodJ undergoes regulated processing to a short form that persists at the flagellar pole of swarmer cells. This study analyzes how PodJ’s role in structural and signaling protein localization impacts organelle synthesis. A PodJ mutant with an internal deletion exhibits reduced sensitivity to pili-tropic phage ΦCbK, resulting from reduced pilA gene expression, which can be linked to altered signaling protein localization. The phage sensitivity defect of a ΔpodJ mutant can be partially suppressed by ectopic pilA expression. Induction of PodJ processing, by manipulation of podJ itself or controlled perP expression, resulted in decreased pilus biogenesis and, when coupled with a podJ mutation that reduced pilA expression, led to complete loss of phage sensitivity. As a whole, the results show that PodJ’s scaffolding role for structural and signaling proteins both contribute to flagellar pole organelle development. PMID:22512778

Alternate bearing in citrus: changes in the expression of flowering control genes and in global gene expression in ON- versus OFF-crop trees.

PubMed

Shalom, Liron; Samuels, Sivan; Zur, Naftali; Shlizerman, Lyudmila; Zemach, Hanita; Weissberg, Mira; Ophir, Ron; Blumwald, Eduardo; Sadka, Avi

2012-01-01

Alternate bearing (AB) is the process in fruit trees by which cycles of heavy yield (ON crop) one year are followed by a light yield (OFF crop) the next. Heavy yield usually reduces flowering intensity the following year. Despite its agricultural importance, how the developing crop influences the following year's return bloom and yield is not fully understood. It might be assumed that an 'AB signal' is generated in the fruit, or in another organ that senses fruit presence, and moves into the bud to determine its fate-flowering or vegetative growth. The bud then responds to fruit presence by altering regulatory and metabolic pathways. Determining these pathways, and when they are altered, might indicate the nature of this putative AB signal. We studied bud morphology, the expression of flowering control genes, and global gene expression in ON- and OFF-crop buds. In May, shortly after flowering and fruit set, OFF-crop buds were already significantly longer than ON-crop buds. The number of differentially expressed genes was higher in May than at the other tested time points. Processes differentially expressed between ON- and OFF-crop trees included key metabolic and regulatory pathways, such as photosynthesis and secondary metabolism. The expression of genes of trehalose metabolism and flavonoid metabolism was validated by nCounter technology, and the latter was confirmed by metabolomic analysis. Among genes induced in OFF-crop trees was one homologous to SQUAMOSA PROMOTER BINDING-LIKE (SPL), which controls juvenile-to-adult and annual phase transitions, regulated by miR156. The expression pattern of SPL-like, miR156 and other flowering control genes suggested that fruit load affects bud fate, and therefore development and metabolism, a relatively long time before the flowering induction period. Results shed light on some of the metabolic and regulatory processes that are altered in ON and OFF buds.

Selenoprotein W controls epidermal growth factor receptor surface expression, activation and degradation via receptor ubiquitination

USDA-ARS?s Scientific Manuscript database

Epidermal growth factor (EGF) receptor (EGFR) is the founding member of the ErbB family of growth factor receptors that modulate a complex network of intracellular signaling pathways controlling growth, proliferation and differentiation. Selenoprotein W (SEPW1) is a diet-regulated, highly conserved...

Protective effect of tanshinone IIA against cardiac hypertrophy in spontaneously hypertensive rats through inhibiting the Cys-C/Wnt signaling pathway

PubMed Central

Feng, Jun; Chen, Hua-Wen; Pi, Li-Juan; Wang, Jin; Zhan, Da-Qian

2017-01-01

The study aimed to investigate the protective effect of tanshinone IIA against cardiac hypertrophy in spontaneously hypertensive rats (SHRs) through the Cys-C/Wnt signaling pathway. Thirty SHRs were randomly divided into cardiac hypertrophy, low- and high-dose tanshinone IIA groups. Ten Wistar-Kyoto rats were selected as control group. The systolic blood pressure (SBP), heart weight (HW), left ventricular weight (LVW) and body weight (BW) of all rats were recorded. HE staining and qRT-PCR were applied to observe the morphology of myocardial tissue and mRNA expressions of COL1A1 and COL3A1. ELISA and Western blotting were used to measure the serum asymmetric dimethylarginine (ADMA), nitric oxide (NO) and cardiac troponin I (cTnI) levels, and the expressions of the Cys-C/Wnt signaling pathway-related proteins, eNOS and Nox4. Compared with the cardiac hypertrophy group, the SBP, HW/BW, LVW/BW, swelling degree of myocardial cells, COL1A1 and COL3A1 mRNA expressions, serum cTnI and ADMA levels, and the Cys-C/Wnt signaling pathway-related proteins and Nox4 expressions in the low- and high-dose tanshinone IIA groups were decreased, but the endothelial NO synthase (eNOS), phosphorylated eNOS (Ser1177) and NO expressions were increased. No significant difference was found between the low- and high-dose tanshinone IIA groups. Our study indicated a protective effect of tanshinone IIA against cardiac hypertrophy in SHRs through inhibiting the Cys-C/Wnt signaling pathway. PMID:28053285

Evidence for Alterations in Stimulatory G proteins and Oxytocin Levels in Children with Autism

PubMed Central

Jacobson, Jill D.; Ellerbeck, Kathryn A.; Kelly, Kelsie A.; Fleming, Kandace K.; Jamison, T. Rene; Coffey, Charles W.; Smith, Catherine M.; Reese, R. Matthew; Sands, Scott A.

2014-01-01

The neurotransmitter oxytocin plays an important role in social affiliation. Low oxytocin levels and defects in the oxytocin receptor have been reported in childhood autism. However, little is known about oxytocin’s post-receptor signaling pathways in autism. Oxytocin signals via stimulatory and inhibitory G proteins. c-fos mRNA expression has been used as a marker of OT signaling as well as of G protein signaling. Herein, we hypothesized that oxytocin and its signaling pathways would be altered in children with autism. We measured plasma oxytocin levels by ELISA, G-protein and c-fos mRNA by PCR, and G proteins by immunoblot in cultured peripheral blood mononuclear cells (PBMCs) in children with autism and in age-matched controls. Males with autism displayed elevated oxytocin levels compared to controls (p<0.05). Children with autism displayed significantly higher mRNA for stimulatory G proteins compared to controls (p<0.05). Oxytocin levels correlated strongly positively with c-fos mRNA levels, but only in control participants (p<0.01). Oxytocin, G-protein, and c-fos mRNA levels correlated inversely with measures of social and emotional behaviors, but only in control participants. These data suggest that children with autism may exhibit a dysregulation in oxytocin and/or its signaling pathways. PMID:24485488

Differential adipokine receptor expression on circulating leukocyte subsets in lean and obese children.

PubMed

Keustermans, Genoveva; van der Heijden, Laila B; Boer, Berlinda; Scholman, Rianne; Nuboer, Roos; Pasterkamp, Gerard; Prakken, Berent; de Jager, Wilco; Kalkhoven, Eric; Janse, Arieke J; Schipper, Henk S

2017-01-01

Childhood obesity prevalence has increased worldwide and is an important risk factor for type 2 diabetes (T2D) and cardiovascular disease (CVD). The production of inflammatory adipokines by obese adipose tissue contributes to the development of T2D and CVD. While levels of circulating adipokines such as adiponectin and leptin have been established in obese children and adults, the expression of adiponectin and leptin receptors on circulating immune cells can modulate adipokine signalling, but has not been studied so far. Here, we aim to establish the expression of adiponectin and leptin receptors on circulating immune cells in obese children pre and post-lifestyle intervention compared to normal weight control children. 13 obese children before and after a 1-year lifestyle intervention were compared with an age and sex-matched normal weight control group of 15 children. Next to routine clinical and biochemical parameters, circulating adipokines were measured, and flow cytometric analysis of adiponectin receptor 1 and 2 (AdipoR1, AdipoR2) and leptin receptor expression on peripheral blood mononuclear cell subsets was performed. Obese children exhibited typical clinical and biochemical characteristics compared to controls, including a higher BMI-SD, blood pressure and circulating leptin levels, combined with a lower insulin sensitivity index (QUICKI). The 1-year lifestyle intervention resulted in stabilization of their BMI-SD. Overall, circulating leukocyte subsets showed distinct adipokine receptor expression profiles. While monocytes expressed high levels of all adipokine receptors, NK and iNKT cells predominantly expressed AdipoR2, and B-lymphocytes and CD4+ and CD8+ T-lymphocyte subsets expressed AdipoR2 as well as leptin receptor. Strikingly though, leukocyte subset numbers and adipokine receptor expression profiles were largely similar in obese children and controls. Obese children showed higher naïve B-cell numbers, and pre-intervention also higher numbers of immature transition B-cells and intermediate CD14++CD16+ monocytes combined with lower total monocyte numbers, compared to controls. Furthermore, adiponectin receptor 1 expression on nonclassical CD14+CD16++ monocytes was consistently upregulated in obese children pre-intervention, compared to controls. However, none of the differences in leukocyte subset numbers and adipokine receptor expression profiles between obese children and controls remained significant after multiple testing correction. First, the distinct adipokine receptor profiles of circulating leukocyte subsets may partly explain the differential impact of adipokines on leukocyte subsets. Second, the similarities in adipokine receptor expression profiles between obese children and normal weight controls suggest that adipokine signaling in childhood obesity is primarily modulated by circulating adipokine levels, instead of adipokine receptor expression.

Calcineurin signaling and PGC-1alpha expression are suppressed during muscle atrophy due to diabetes.

PubMed

Roberts-Wilson, Tiffany K; Reddy, Ramesh N; Bailey, James L; Zheng, Bin; Ordas, Ronald; Gooch, Jennifer L; Price, S Russ

2010-08-01

PGC-1alpha is a transcriptional coactivator that controls energy homeostasis through regulation of glucose and oxidative metabolism. Both PGC-1alpha expression and oxidative capacity are decreased in skeletal muscle of patients and animals undergoing atrophy, suggesting that PGC-1alpha participates in the regulation of muscle mass. PGC-1alpha gene expression is controlled by calcium- and cAMP-sensitive pathways. However, the mechanism regulating PGC-1alpha in skeletal muscle during atrophy remains unclear. Therefore, we examined the mechanism responsible for decreased PGC-1alpha expression using a rodent streptozotocin (STZ) model of chronic diabetes and atrophy. After 21days, the levels of PGC-1alpha protein and mRNA were decreased. We examined the activation state of CREB, a potent activator of PGC-1alpha transcription, and found that phospho-CREB was paradoxically high in muscle of STZ-rats, suggesting that the cAMP pathway was not involved in PGC-1alpha regulation. In contrast, expression of calcineurin (Cn), a calcium-dependent phosphatase, was suppressed in the same muscles. PGC-1alpha expression is regulated by two Cn substrates, MEF2 and NFATc. Therefore, we examined MEF2 and NFATc activity in muscles from STZ-rats. Target genes MRF4 and MCIP1.4 mRNAs were both significantly reduced, consistent with reduced Cn signaling. Moreover, levels of MRF4, MCIP1.4, and PGC-1alpha were also decreased in muscles of CnAalpha-/- and CnAbeta-/- mice without diabetes indicating that decreased Cn signaling, rather than changes in other calcium- or cAMP-sensitive pathways, were responsible for decreased PGC-1alpha expression. These findings demonstrate that Cn activity is a major determinant of PGC-1alpha expression in skeletal muscle during diabetes and possibly other conditions associated with loss of muscle mass.

Calcineurin signaling and PGC-1α expression are suppressed during muscle atrophy due to diabetes

PubMed Central

Roberts-Wilson, Tiffany K.; Reddy, Ramesh N.; Bailey, James L.; Zheng, Bin; Ordas, Ronald; Gooch, Jennifer L.; Price, S. Russ

2010-01-01

PGC-1α is a transcriptional coactivator that controls energy homeostasis through regulation of glucose and oxidative metabolism. Both PGC-1α expression and oxidative capacity are decreased in skeletal muscle of patients and animals undergoing atrophy, suggesting that PGC-1α participates in the regulation of muscle mass. PGC-1α gene expression is controlled by calcium- and cAMP-sensitive pathways. However, the mechanism regulating PGC-1α in skeletal muscle during atrophy remains unclear. Therefore, we examined the mechanism responsible for decreased PGC-1α expression using a rodent streptozotocin (STZ) model of chronic diabetes and atrophy. After 21d, the levels of PGC-1α protein and mRNA were decreased. We examined the activation state of CREB, a potent activator of PGC-1α transcription, and found that phospho-CREB was paradoxically high in muscle of STZ-rats, suggesting that the cAMP pathway was not involved in PGC-1α regulation. In contrast, expression of calcineurin (Cn), a calcium-dependent phosphatase, was suppressed in the same muscles. PGC-1α expression is regulated by two Cn substrates, MEF2 and NFATc. Therefore, we examined MEF2 and NFATc activity in muscles from STZ-rats. Target genes MRF4 and MCIP1.4 were both significantly reduced, consistent with reduced Cn signaling. Moreover, levels of MRF4, MCIP1.4, and PGC-1α were also decreased in muscles of CnAα-/- and CnAβ-/- mice without diabetes indicating that decreased Cn signaling, rather than changes in other calcium- or cAMP-sensitive pathways, were responsible for decreased PGC-1α expression. These findings demonstrate that Cn activity is a major determinant of PGC-1α expression in skeletal muscle during diabetes and possibly other conditions associated with loss of muscle mass. PMID:20359506

Hedgehog signaling is synergistically enhanced by nutritional deprivation and ligand stimulation in human fibroblasts of Gorlin syndrome.

PubMed

Mizuochi, Hiromi; Fujii, Katsunori; Shiohama, Tadashi; Uchikawa, Hideki; Shimojo, Naoki

2015-02-13

Hedgehog signaling is a pivotal developmental pathway that comprises hedgehog, PTCH1, SMO, and GLI proteins. Mutations in PTCH1 are responsible for Gorlin syndrome, which is characterized by developmental defects and tumorigenicity. Although the hedgehog pathway has been investigated extensively in Drosophila and mice, its functional roles have not yet been determined in human cells. In order to elucidate the mechanism by which transduction of the hedgehog signal is regulated in human tissues, we employed human fibroblasts derived from three Gorlin syndrome patients and normal controls. We investigated GLI1 transcription, downstream of hedgehog signaling, to assess native signal transduction, and then treated fibroblasts with a recombinant human hedgehog protein with or without serum deprivation. We also examined the transcriptional levels of hedgehog-related genes under these conditions. The expression of GLI1 mRNA was significantly higher in Gorlin syndrome-derived fibroblasts than in control cells. Hedgehog stimulation and nutritional deprivation synergistically enhanced GLI1 transcription levels, and this was blocked more efficiently by vismodegib, a SMO inhibitor, than by the natural compound, cyclopamine. Messenger RNA profiling revealed the increased expression of Wnt signaling and morphogenetic molecules in these fibroblasts. These results indicated that the hedgehog stimulation and nutritional deprivation synergistically activated the hedgehog signaling pathway in Gorlin syndrome fibroblasts, and this was associated with increments in the transcription levels of hedgehog-related genes such as those involved in Wnt signaling. These fibroblasts may become a significant tool for predicting the efficacies of hedgehog molecular-targeted therapies such as vismodegib. Copyright © 2015 Elsevier Inc. All rights reserved.

Unexpected role for dosage compensation in the control of dauer arrest, insulin-like signaling, and FoxO transcription factor activity in Caenorhabditis elegans.

PubMed

Dumas, Kathleen J; Delaney, Colin E; Flibotte, Stephane; Moerman, Donald G; Csankovszki, Gyorgyi; Hu, Patrick J

2013-07-01

During embryogenesis, an essential process known as dosage compensation is initiated to equalize gene expression from sex chromosomes. Although much is known about how dosage compensation is established, the consequences of modulating the stability of dosage compensation postembryonically are not known. Here we define a role for the Caenorhabditis elegans dosage compensation complex (DCC) in the regulation of DAF-2 insulin-like signaling. In a screen for dauer regulatory genes that control the activity of the FoxO transcription factor DAF-16, we isolated three mutant alleles of dpy-21, which encodes a conserved DCC component. Knockdown of multiple DCC components in hermaphrodite and male animals indicates that the dauer suppression phenotype of dpy-21 mutants is due to a defect in dosage compensation per se. In dpy-21 mutants, expression of several X-linked genes that promote dauer bypass is elevated, including four genes encoding components of the DAF-2 insulin-like pathway that antagonize DAF-16/FoxO activity. Accordingly, dpy-21 mutation reduced the expression of DAF-16/FoxO target genes by promoting the exclusion of DAF-16/FoxO from nuclei. Thus, dosage compensation enhances dauer arrest by repressing X-linked genes that promote reproductive development through the inhibition of DAF-16/FoxO nuclear translocation. This work is the first to establish a specific postembryonic function for dosage compensation in any organism. The influence of dosage compensation on dauer arrest, a larval developmental fate governed by the integration of multiple environmental inputs and signaling outputs, suggests that the dosage compensation machinery may respond to external cues by modulating signaling pathways through chromosome-wide regulation of gene expression.

A2B Adenosine Receptor Agonist Improves Erectile Function in Diabetic Rats.

PubMed

Wen, Jiaming; Wang, Bohan; Du, Chuanjun; Xu, Gang; Zhang, Zhewei; Li, Yi; Zhang, Nan

2015-10-01

Diabetes is an important risk factor for erectile dysfunction (ED). Recent studies have indicated that A2B adenosine receptor (ADORA2B) signaling is essential for penile erection. Thus, we hypothesize that diabetic ED may be attributed to impaired A2B adenosine signaling. To test this hypothesis, we generated diabetic rats by injecting streptozocin as animal model. After 12 weeks, immunohistochemistry staining was used to localize the expression of ADORA2B. Western Blot and quantitative PCR were employed to determine ADORA2B expression level. Intracavernosal pressure (ICP) measurement was used to evaluate erectile function. Diabetic rats received a single intravenous injection of BAY 60-6583, an ADORA2B agonist, or vehicle solution, at 60 min before the ICP measurement. The results showed that ADORA2B expressed in the nerve bundle, smooth muscle, and endothelium in penile tissue of control mice. Western Blot and quantitative PCR results indicated that the expression levels of ADORA2B protein and mRNA were significantly reduced in penile tissues of diabetic rats. Functional studies showed that the erectile response induced by electrical stimulation was remarkably decreased in diabetic rats, compared with age-matched control rats. However, at 60 min after BAY 60-6583 treatment, the erectile function was improved in diabetic rats, suggesting that enhancement of ADORA2B signaling may improve erectile function in diabetic ED. This preclinical study has revealed a previously unrecognized therapeutic possibility of BAY 60-6583 as an effective and mechanism-based drug to treat diabetic ED. In conclusion, we propose that impaired A2B adenosine signaling is one of the pathological mechanisms of diabetic ED.

Identification of several circulating microRNAs from a genome-wide circulating microRNA expression profile as potential biomarkers for impaired glucose metabolism in polycystic ovarian syndrome.

PubMed

Jiang, Linlin; Huang, Jia; Chen, Yaxiao; Yang, Yabo; Li, Ruiqi; Li, Yu; Chen, Xiaoli; Yang, Dongzi

2016-07-01

This study aimed to detect serum microRNAs (miRNAs) differentially expressed between polycystic ovary syndrome (PCOS) patients with impaired glucose metabolism (IGM), PCOS patients with normal glucose tolerance (NGT), and healthy controls. A TaqMan miRNA array explored serum miRNA profiles as a pilot study, then selected miRNAs were analyzed in a validation cohort consisting of 65 PCOS women with IGM, 65 PCOS women with NGT, and 45 healthy women The relative expression of miR-122, miR-193b, and miR-194 was up-regulated in PCOS patients compared with controls, whereas that of miR-199b-5p was down-regulated. Furthermore, miR-122, miR-193b, and miR-194 were increased in the PCOS-IGM group compared with the PCOS-NGT group. Multiple linear regression analyses revealed that miR-193b and body mass index contributed independently to explain 43.7 % (P < 0.0001) of homeostasis model assessment-insulin resistance after adjustment for age. Investigation of diagnostic values confirmed the optimal combination of BMI and miR-193b to explore the possibility of IGM in PCOS women with area under the curve of 0.752 (95 % CI 0.667-0.837, P < 0.001). Bioinformatics analysis indicated that the predicted target functions of these miRNAs mainly involved glycometabolism and ovarian follicle development pathways, including the insulin signaling pathway, the neurotrophin signaling pathway, the PI3K-AKT signaling pathway, and regulation of actin cytoskeleton. This study expands our knowledge of the serum miRNA expression profiles of PCOS patients with IGM and the predicted target signal pathways involved in disease pathophysiology.

Reciprocal repression between Fgf8 and miR-133 regulates cardiac induction through Bmp2 signaling.

PubMed

Lopez-Sanchez, Carmen; Franco, Diego; Bonet, Fernando; Garcia-Lopez, Virginio; Aranega, Amelia; Garcia-Martinez, Virginio

2015-12-01

This data article contains complementary figures and results related to the research article entitled "Negative Fgf8-Bmp2 feed-back is controlled by miR-130 during early cardiac specification" [15], which reveals what specific role miR-130 plays during the cardiac induction process. This study evidenced miR-130 a putative microRNA that targets Erk1/2 (Mapk1) 3'UTR- as a necessary linkage in the control of Fgf8 signaling, mediated by Bmp2. Thus, miR-130 regulates a negative Fgf8-Bmp2 feed-back loop responsible to achieve early cardiac specification. A significant aspect supporting our conclusions is given by the expression pattern of miR-130 during early cardiac specification, as well as by those results obtained after the designed experimental procedures. The data presented here reveal that miR-133 is also expressed within the precardiac areas during early cardiogenesis, pattern which is comparable to that of FGFR1, receptor involved in the Fgf8/ERK signaling pathway. Interestingly, our miR-133 overexpression experiments resulted in a decrease of Fgf8 expression, whereas we observed an increase of Bmp2 and subsequently of cardiac specific markers Nkx-2.5 and Gata4. Additionally, our loss-of-function experiments -through Fgf8 siRNA electroporation- showed an increase of miR-133 expression. Finally, after our Bmp2 experiments, we observed that miR-133 is upstream-regulated by Bmp2. All those results suggest that miR-133 also constitutes a crucial linkage in the crosstalk between Fgf8 and Bmp2 signaling by regulating the Fgf8/ERK pathway during cardiac induction.

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.

Light-up and FRET aptamer reporters; evaluating their applications for imaging transcription in eukaryotic cells

DOE PAGES

Ilgu, Muslum; Ray, Judhajeet; Bendickson, Lee; ...

2015-12-17

The regulation of RNA transcription is central to cellular function. Changes in gene expression drive differentiation and cellular responses to events such as injury. RNA trafficking can also have a large impact on protein expression and its localization. Thus, the ability to image RNA transcription and trafficking in real time and in living cells is a worthwhile goal that has been difficult to achieve. The availability of “light-up” aptamers that cause an increase in fluorescence of their ligands when bound by the aptamer have shown promise for reporting on RNA production and localization in vivo. Here we have investigated twomore » light-up aptamers (the malachite green aptamer and the Spinach aptamers) for their suitabilities as reporters of RNA expression in vivo using two eukaryotic cell types, yeast and mammalian. Our analysis focused on the aptamer ligands, their contributions to background noise, and the impact of tandem aptamer strings on signal strength and ligand affinity. Whereas the background fluorescence is very low in vitro, this is not always true for cell imaging. Our results suggest the need for caution in using light-up aptamers as reporters for imaging RNA. In particular, images should be collected and analyzed by operators blinded to the sample identities. The appropriate control condition of ligand with the cells in the absence of aptamer expression must be included in each experiment. This control condition establishes that the specific interaction of ligand with aptamer, rather than nonspecific interactions with unknown cell elements, is responsible for the observed fluorescent signals. As a result, high background signals due to nonspecific interactions of aptamer ligands with cell components can be minimized by using IMAGEtags (Intracellular Multiaptamer GEnetic tags), which signal by FRET and are promising RNA reporters for imaging transcription.« less

Genetic and epigenetic mechanisms of gene regulation during lens development

PubMed Central

Cvekl, Ales; Duncan, Melinda K.

2007-01-01

Recent studies demonstrated a number of links between chromatin structure, gene expression, extracellular signaling and cellular differentiation during lens development. Lens progenitor cells originate from a pool of common progenitor cells, the pre-placodal region (PPR) which is formed due to a complex exchange of extracellular signals between the neural plate, naïve ectoderm and mesendoderm. A specific commitment to the lens program over alternate choices such as the formation of olfactory epithelium or the anterior pituitary is manifested by the formation of a thickened surface ectoderm, the lens placode. Mouse lens progenitor cells are characterized by the expression of a complement of lens lineage-specific transcription factors including Pax6, Six3 and Sox2, controlled by FGF and BMP signaling, followed later by c-Maf, Mab21like1, Prox1 and FoxE3. Proliferation of lens progenitors together with their morphogenetic movements results in the formation of the lens vesicle. This transient structure, comprised of lens precursor cells, is polarized with its anterior cells retaining their epithelial morphology and proliferative capacity, whereas the posterior lens precursor cells initiate terminal differentiation forming the primary lens fibers. Lens differentiation is marked by expression and accumulation of crystallins and other structural proteins. The transcriptional control of crystallin genes is characterized by the reiterative use of transcription factors required for the establishment of lens precursors in combination with more ubiquitously expressed factors (e.g. AP-1, AP-2α, CREB and USF) and recruitment of histone acetyltransferases (HATs) CBP and p300, and chromatin remodeling complexes SWI/SNF and ISWI. These studies have poised the study of lens development at the forefront of efforts to understand the connections between development, cell signaling, gene transcription and chromatin remodeling. PMID:17905638

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

Human cytomegalovirus UL76 induces chromosome aberrations

PubMed Central

2009-01-01

Background Human cytomegalovirus (HCMV) is known to induce chromosome aberrations in infected cells, which can lead to congenital abnormalities in infected fetuses. HCMV UL76 belongs to a conserved protein family from herpesviruses. Some reported roles among UL76 family members include involvement in virulence determination, lytic replication, reactivation of latent virus, modulation of gene expression, induction of apoptosis, and perturbation of cell cycle progression, as well as potential nuclease activity. Previously, we have shown that stable expression of UL76 inhibits HCMV replication in glioblastoma cells. Methods To examine chromosomal integrity and the DNA damage signal γ-H2AX in cells constitutively expressing UL76, immunofluorescent cell staining and Western blotting were performed. The comet assay was employed to assess DNA breaks in cells transiently expressing UL76. Results We report that stably transfected cells expressing UL76 developed chromosome aberrations including micronuclei and misaligned chromosomes, lagging and bridging. In mitotic cells expressing UL76, aberrant spindles were increased compared to control cells. However, cells with supernumerary centrosomes were marginally increased in UL76-expressing cells relative to control cells. We further demonstrated that UL76-expressing cells activated the DNA damage signal γ-H2AX and caused foci formation in nuclei. In addition, the number of cells with DNA breaks increased in proportion to UL76 protein levels. Conclusion Our findings suggest that the virus-associated protein UL76 induces DNA damage and the accumulation of chromosome aberrations. PMID:19930723

Gene expression disorders of innate antibacterial signaling pathway in pancreatic cancer patients: implications for leukocyte dysfunction and tumor progression

PubMed Central

Dąbrowska, Aleksandra; Lech, Gustaw; Słodkowski, Maciej; Słotwińska, Sylwia M.

2014-01-01

The study was carried out to investigate changes in gene expression of innate antibacterial signaling pathways in patients with pancreatic cancer. Expression of the following genes was measured in peripheral blood leukocytes of 55 patients with pancreatic adenocarcinoma using real-time polymerase chain reaction (RT-PCR): TLR4, NOD1, MyD88, TRAF6 and HMGB1. The levels of expression of TLR4, NOD1 and TRAF6 genes were significantly elevated (p = 0.007; p = 0.001 and p = 0.01, respectively), while MyD88 expression was markedly reduced (p = 0.0002), as compared to controls. Expression of TLR4 and NOD1 exceeded the normal level more than 3.5-fold and there was a significant correlation found between the expression of these genes (r = 0.558, p < 0.001). TLR4, NOD1 and MyD88 genes were expressed at a similar level both before and after surgery. No significant changes in the expression of HMGB1 gene were observed. The results of the study clearly indicate abnormal expression of genes belonging to innate antibacterial signaling pathways in peripheral blood leukocytes of patients with pancreatic cancer, which may lead to leukocyte dysfunction. Overexpression of TLR4, NOD1 and TRAF6 genes, and decreased MyD88 gene expression may contribute to chronic inflammation and tumor progression by up-regulation of the innate antibacterial response. The parameters tested are useful for monitoring innate immunity gene disorders and pancreatic cancer progression. PMID:26155170

Disruption of THY-1 signaling in alveolar lipofibroblasts in experimentally induced congenital diaphragmatic hernia.

PubMed

Friedmacher, Florian; Hofmann, Alejandro Daniel; Takahashi, Hiromizu; Takahashi, Toshiaki; Gosemann, Jan-Hendrik; Puri, Prem

2014-02-01

Pulmonary hypoplasia (PH), characterized by alveolar immaturity, remains the main cause of neonatal mortality and long-term morbidity in infants with congenital diaphragmatic hernia (CDH). Lipid-containing interstitial fibroblasts (LIFs) are critically important for normal alveolar development. Thymocyte antigen 1 (Thy-1) is a highly expressed cell-surface protein in this specific subset of lung fibroblasts, which plays a key role in fetal alveolarization by coordinating the differentiation and lipid homeostasis of alveolar LIFs. Thy-1 increases the lipid content of LIFs by upregulation of adipocyte differentiation-related protein (ADRP), a lipogenic molecular marker characterizing pulmonary LIFs. Thy-1 (-/-) mice further show impaired alveolar development with reduced proliferation of pulmonary LIFs, resulting in a PH-similar phenotype. We hypothesized that pulmonary Thy-1 signaling is disrupted in experimentally induced CDH, which may has an adverse effect on the lipid content of alveolar LIFs. Timed-pregnant Sprague-Dawley rats were treated with either 100 mg nitrofen or vehicle on embryonic day 9.5 (E9.5). Fetuses were killed on E21.5, and lungs were divided into controls (n = 14) and CDH-associated PH (n = 14). Pulmonary gene expression levels of Thy-1 and ADRP were assessed by quantitative real-time PCR. ADRP immunohistochemistry and oil-red-O staining were used to localize alveolar LIF expression and lipid droplets. Immunofluorescence double staining for Thy-1 and oil-red-O was performed to evaluate Thy-1 expression and lipid content in alveolar LIFs. Radial alveolar count was significantly reduced in CDH-associated PH with significant downregulation of pulmonary Thy-1 and ADRP mRNA expression compared to controls. ADRP immunoreactivity and lipid droplets were markedly diminished in alveolar interstitial cells, which coincided with decreased alveolar LIF expression in CDH-associated PH compared to controls. Confocal laser scanning microscopy confirmed markedly decreased Thy-1 expression and lipid content in alveolar LIFs of CDH-associated PH compared to controls. Our study provides strong evidence that disruption of pulmonary Thy-1 signaling results in reduced lipid droplets in alveolar LIFs and may thus contribute to PH in the nitrofen-induced CDH model. Treatment modalities aimed at increasing lipid content in alveolar LIFs may therefore have a therapeutic potential in attenuating CDH-associated PH.

TGF-β1 resulting in differential microRNA expression in bovine granulosa cells.

PubMed

Xu, Yefen; Niu, Jiaqiang; Xi, Guangying; Niu, Xuezhi; Wang, Yuheng; Guo, Ming; Yangzong, Qiangba; Yao, Yilong; Sizhu, Suo Lang; Tian, Jianhui

2018-07-15

To explore the expression profile of the cellular miRNAs in bovine ovarian granulosa cells responding to transforming growth factor-β1 (TGF-β1), the effect of TGF-β1 on cell proliferation was firstly investigated by CCK-8 method and the results showed that there was a significant inhibitory effect on bovine granulosa cell proliferation treated with 5/10 ng/mL human recombinant TGF-β1 for 24 h compared to the control (P < 0.05). Then, we performed high-throughput sequencing of two small RNA libraries prepared from cultured bovine granulosa cells stimulated with or without 10 ng/mL human recombinant TGF-β1. A total of 13,257,248 and 138,726,391 clean reads per library were obtained from TGF-β1 and control groups, respectively. There were 498 and 499 bovine-specific exist miRNAs (exist miRNAs), 627 and 570 conserved known miRNAs (known miRNAs), and 593 and 585 predicted novel miRNAs in TGF-β1 and control groups, respectively. A total of 78 miRNAs with significant differential expression, including 39 up-regulated miRNAs and 39 down-regulated miRNAs were identified in the TGF-β1 group compared with the control. Real-time quantitative PCR analyses of bta-miR-106a and bta-miR-1434-5p showed that their up-expressions were interrupted by SB431542, an inhibitor that blocks TGFβ1/Smad signaling, which supported the sequencing data. GO analysis showed involvement of the predicted genes of the differentially expressed miRNAs in a broad spectrum of cell biological processes, cell components, and molecular functions. KEGG pathway analysis of the predicted miRNA targets further indicated that these differentially expressed miRNAs are involved in various signaling pathways, such as Wnt, MAPK, and TGF-β signaling, which might be involved in follicular development. These results provide valuable information on the composition, expression, and function of miRNAs in bovine granulosa cells responding to TGF-β1, and will aid in understanding the molecular mechanisms of TGF-β1 in granulosa cells. Copyright © 2018 Elsevier B.V. All rights reserved.

Identification of signaling pathways associated with cancer protection in Laron syndrome.

PubMed

Lapkina-Gendler, Lena; Rotem, Itai; Pasmanik-Chor, Metsada; Gurwitz, David; Sarfstein, Rive; Laron, Zvi; Werner, Haim

2016-05-01

The growth hormone (GH)-insulin-like growth factor-1 (IGF1) pathway emerged in recent years as a critical player in cancer biology. Enhanced expression or activation of specific components of the GH-IGF1 axis, including the IGF1 receptor (IGF1R), is consistently associated with a transformed phenotype. Recent epidemiological studies have shown that patients with Laron syndrome (LS), the best-characterized entity among the congenital IGF1 deficiencies, seem to be protected from cancer development. To identify IGF1-dependent genes and signaling pathways associated with cancer protection in LS, we conducted a genome-wide analysis using immortalized lymphoblastoid cells derived from LS patients and healthy controls of the same gender, age range, and ethnic origin. Our analyses identified a collection of genes that are either over- or under-represented in LS-derived lymphoblastoids. Gene differential expression occurs in several gene families, including cell cycle, metabolic control, cytokine-cytokine receptor interaction, Jak-STAT signaling, and PI3K-AKT signaling. Major differences between LS and healthy controls were also noticed in pathways associated with cell cycle distribution, apoptosis, and autophagy. Our results highlight the key role of the GH-IGF1 axis in the initiation and progression of cancer. Furthermore, data are consistent with the concept that homozygous congenital IGF1 deficiency may confer protection against future tumor development. © 2016 Society for Endocrinology.

Characterization of New Otic Enhancers of the Pou3f4 Gene Reveal Distinct Signaling Pathway Regulation and Spatio-Temporal Patterns

PubMed Central

Robert-Moreno, Àlex; Naranjo, Silvia; de la Calle-Mustienes, Elisa; Gómez-Skarmeta, José Luis; Alsina, Berta

2010-01-01

POU3F4 is a member of the POU-homedomain transcription factor family with a prominent role in inner ear development. Mutations in the human POU3F4 coding unit leads to X-linked deafness type 3 (DFN3), characterized by conductive hearing loss and progressive sensorineural deafness. Microdeletions found 1 Mb 5′ upstream of the coding region also displayed the same phenotype, suggesting that cis-regulatory elements might be present in that region. Indeed, we and others have recently identified several enhancers at the 1 Mb 5′ upstream interval of the pou3f4 locus. Here we characterize the spatio-temporal patterns of these regulatory elements in zebrafish transgenic lines. We show that the most distal enhancer (HCNR 81675) is activated earlier and drives GFP reporter expression initially to a broad ear domain to progressively restrict to the sensory patches. The proximal enhancer (HCNR 82478) is switched later during development and promotes expression, among in other tissues, in sensory patches from its onset. The third enhancer (HCNR 81728) is also active at later stages in the otic mesenchyme and in the otic epithelium. We also characterize the signaling pathways regulating these enhancers. While HCNR 81675 is regulated by very early signals of retinoic acid, HCNR 82478 is regulated by Fgf activity at a later stage and the HCNR 81728 enhancer is under the control of Hh signaling. Finally, we show that Sox2 and Pax2 transcription factors are bound to HCNR 81675 genomic region during otic development and specific mutations to these transcription factor binding sites abrogates HCNR 81675 enhancer activity. Altogether, our results suggest that pou3f4 expression in inner ear might be under the control of distinct regulatory elements that fine-tune the spatio-temporal activity of this gene and provides novel data on the signaling mechanisms controlling pou3f4 function. PMID:21209840

Leptin receptor expression in hindbrain Glp-1 neurons regulates food intake and energy balance in mice.

PubMed

Scott, Michael M; Williams, Kevin W; Rossi, Jari; Lee, Charlotte E; Elmquist, Joel K

2011-06-01

Leptin is an adipose-derived hormone that signals to inform the brain of nutrient status; loss of leptin signaling results in marked hyperphagia and obesity. Recent work has identified several groups of neurons that contribute to the effects of leptin to regulate energy balance, but leptin receptors are distributed throughout the brain, and the function of leptin signaling in discrete neuronal populations outside of the hypothalamus has not been defined. In the current study, we produced mice in which the long form of the leptin receptor (Lepr) was selectively ablated using Cre-recombinase selectively expressed in the hindbrain under control of the paired-like homeobox 2b (Phox2b) promoter (Phox2b Cre Lepr(flox/flox) mice). In these mice, Lepr was deleted from glucagon-like 1 peptide-expressing neurons resident in the nucleus of the solitary tract. Phox2b Cre Lepr(flox/flox) mice were hyperphagic, displayed increased food intake after fasting, and gained weight at a faster rate than wild-type controls. Paradoxically, Phox2b Cre Lepr(flox/flox) mice also exhibited an increased metabolic rate independent of a change in locomotor activity that was dependent on food intake, and glucose homeostasis was normal. Together, these data support a physiologically important role of direct leptin action in the hindbrain.

Effect of testosterone on the proliferation and collagen synthesis of cardiac fibroblasts induced by angiotensin II in neonatal rat

PubMed Central

Yang, Xiaocun; Wang, Ying; Yan, Shuxun; Sun, Lina; Yang, Guojie; Li, Yuan; Yu, Chaonan

2017-01-01

ABSTRACT The objective is to explore the effect of testosterone on the proliferation and collagen synthesis of neonatal rat cardiac fibroblasts (CF) induced by Angiotensin II (Ang II) and the underlying mechanisms. Derived from neonatal rats, the CFs were divided into 4 groups: the control group, Ang II group, testosterone group, and testosterone + Ang II group in vitro. Cell cycle distribution, collagen counts, and phosphorylated extracellular signal-regulated kinase (ERK1/2) (p - ERK1/2) expression were assessed by flow cytometry, VG staining, and immunocytochemistry, respectively. The Ang II group had a much higher proportion of cells in the S-phase, higher collagen contents, and a higher p - ERK1/2 expression level than either the control or testosterone group. However, these factors were significantly reduced in the testosterone + Ang II group as compared to the Ang II group. In terms of cells in the S-phase and the collagen contents, there was not a significant difference between the testosterone group and the control. However, the protein expression of p-ERK1/2 was significantly increased in the testosterone group as compared to the control. Testosterone inhibits the proliferation and collagen synthesis of CF induced by Ang II. The underlying mechanism may involve the ERK1/2 signaling pathway. PMID:27791460

Leptin regulation of bone resorption by the sympathetic nervous system and CART.

PubMed

Elefteriou, Florent; Ahn, Jong Deok; Takeda, Shu; Starbuck, Michael; Yang, Xiangli; Liu, Xiuyun; Kondo, Hisataka; Richards, William G; Bannon, Tony W; Noda, Masaki; Clement, Karine; Vaisse, Christian; Karsenty, Gerard

2005-03-24

Bone remodelling, the mechanism by which vertebrates regulate bone mass, comprises two phases, namely resorption by osteoclasts and formation by osteoblasts; osteoblasts are multifunctional cells also controlling osteoclast differentiation. Sympathetic signalling via beta2-adrenergic receptors (Adrb2) present on osteoblasts controls bone formation downstream of leptin. Here we show, by analysing Adrb2-deficient mice, that the sympathetic nervous system favours bone resorption by increasing expression in osteoblast progenitor cells of the osteoclast differentiation factor Rankl. This sympathetic function requires phosphorylation (by protein kinase A) of ATF4, a cell-specific CREB-related transcription factor essential for osteoblast differentiation and function. That bone resorption cannot increase in gonadectomized Adrb2-deficient mice highlights the biological importance of this regulation, but also contrasts sharply with the increase in bone resorption characterizing another hypogonadic mouse with low sympathetic tone, the ob/ob mouse. This discrepancy is explained, in part, by the fact that CART ('cocaine amphetamine regulated transcript'), a neuropeptide whose expression is controlled by leptin and nearly abolished in ob/ob mice, inhibits bone resorption by modulating Rankl expression. Our study establishes that leptin-regulated neural pathways control both aspects of bone remodelling, and demonstrates that integrity of sympathetic signalling is necessary for the increase in bone resorption caused by gonadal failure.

Compensation of the AKT signaling by ERK signaling in transgenic mice hearts overexpressing TRIM72

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

Ham, Young-Mi, E-mail: youngmi_ham@hms.harvard.edu; Department of Cell Biology, Harvard Medical School, Boston, MA 02115; Mahoney, Sarah Jane

The AKT and ERK signaling pathways are known to be involved in cell hypertrophy, proliferation, survival and differentiation. Although there is evidence for crosstalk between these two signaling pathways in cellulo, there is less evidence for cross talk in vivo. Here, we show that crosstalk between AKT and ERK signaling in the hearts of TRIM72-overexpressing transgenic mice (TRIM72-Tg) with alpha-MHC promoter regulates and maintains their heart size. TRIM72, a heart- and skeletal muscle-specific protein, downregulates AKT-mTOR signaling via IRS-1 degradation and reduces the size of rat cardiomyocytes and the size of postnatal TRIM72-Tg hearts. TRIM72 expression was upregulated by hypertrophicmore » inducers in cardiomyocytes, while IRS-1 was downregulated by IGF-1. TRIM72 specifically regulated IGF-1-dependent AKT-mTOR signaling, resulting in a reduction of the size of cardiomyocytes. Postnatal TRIM72-Tg hearts were smaller than control-treated hearts with inhibition of AKT-mTOR signaling. However, adult TRIM72-Tg hearts were larger than of control despite the suppression of AKT-mTOR signaling. Activation of ERK, PKC-α, and JNK were observed to be elevated in adult TRIM72-Tg, and these signals were mediated by ET-1 via the ET receptors A and B. Altogether, these results suggest that AKT signaling regulates cardiac hypertrophy in physiological conditions, and ERK signaling compensates for the absence of AKT signaling during TRIM72 overexpression, leading to pathological hypertrophy. -- Highlights: • TRIM72 inhibits AKT signaling through ubiquitination of IRS-1 in cardiac cells. • TRIM72 regulates the size of cardiac cells. • TRIM72 regulates size of postnatal TRIM72-overexpressing transgenic mice hearts. • Adult TRIM72-overexpressing transgenic mice hearts showed cardiac dysfunction. • Adult TRIM72 transgenic mice hearts showed higher expression of endothelin receptors.« less

The Nuclear Receptor AhR Controls Bone Homeostasis by Regulating Osteoclast Differentiation via the RANK/c-Fos Signaling Axis.

PubMed

Izawa, Takashi; Arakaki, Rieko; Mori, Hiroki; Tsunematsu, Takaaki; Kudo, Yasusei; Tanaka, Eiji; Ishimaru, Naozumi

2016-12-15

The aryl hydrocarbon receptor (AhR) pathway plays a key role in receptor activator of NF-κB ligand (RANKL)-mediated osteoclastogenesis. However, the mechanism underlying the regulation of AhR expression in osteoclasts and the signaling pathway through which AhR controls osteoclastogenesis remain unclear. We found that the expression of AhR in bone marrow-derived osteoclasts was upregulated by RANKL at an earlier stage than was the expression of signature osteoclast genes such as those encoding cathepsin K and NFAT, cytoplasmic, calcineurin-dependent 1. In response to RANKL, bone marrow macrophages isolated from AhR -/- mice exhibited impaired phosphorylation of Akt and MAPK as well as NF-κB, whereas their response to M-CSF remained unchanged. Osteoclast differentiation mediated by the AhR signaling pathway was also regulated in an RANKL/c-Fos-dependent manner. Furthermore, ligand activation of AhR by the smoke toxin benzo[a]pyrene accelerated osteoclast differentiation in a receptor-dependent manner, and AhR-dependent regulation of mitochondrial biogenesis in osteoclasts was observed. Moreover, AhR -/- mice exhibited impaired bone healing with delayed endochondral ossification. Taken together, the present results suggest that the RANKL/AhR/c-Fos signaling axis plays a critical role in osteoclastogenesis, thereby identifying the potential of AhR in treating pathological, inflammatory, or metabolic disorders of the bone. Copyright © 2016 by The American Association of Immunologists, Inc.

HCV-induced miR146a controls SOCS1/STAT3 and cytokine expression in monocytes to promote regulatory T cell development

PubMed Central

Ren, Jun P; Ying, Rue S; Cheng, Yong Q.; Wang, Ling; Elgazzar, Mohamed A.; Li, Guang Y.; Ning, Shun B.; Moorman, Jonathan P.; Yao, Zhi Q.

2016-01-01

Host innate and adaptive immune responses must be tightly regulated by an intricate balance between positive and negative signals to ensure their appropriate onset and termination while fighting pathogens and avoiding autoimmunity; persistent pathogens may usurp these regulatory machineries to dampen host immune responses for their persistence in vivo. Here we demonstrate that miR146a is up-regulated in monocytes from hepatitis C virus (HCV)-infected individuals compared to control subjects. Interestingly, miR146a expression in monocytes without HCV infection increased, whereas its level in monocytes with HCV infection decreased, following Toll-like receptor (TLR) stimulation. This miR146a induction by HCV infection and differential response to TLR stimulation were recapitulated in vitro in monocytes co-cultured with hepatocytes with or without HCV infection. Importantly, inhibition of miR146a in monocytes from HCV-infected patients led to a decrease in IL-23, IL-10, and TGF-β expressions through induction of suppressor of cytokine signaling 1 (SOCS1) and inhibition of signal transducer and activator transcription 3 (STAT3), and this subsequently resulted in a decrease in regulatory T cells (Tregs) accumulated during HCV infection. These results suggest that miR146a may regulate SOCS1/STAT3 and cytokine signaling in monocytes, directing T cell differentiation and balancing immune clearance and immune injury during chronic viral infection. PMID:27004559

Positional signaling and expression of ENHANCER OF TRY AND CPC1 are tuned to increase root hair density in response to phosphate deficiency in Arabidopsis thaliana.

PubMed

Savage, Natasha; Yang, Thomas J W; Chen, Chung Ying; Lin, Kai-Lan; Monk, Nicholas A M; Schmidt, Wolfgang

2013-01-01

Phosphate (Pi) deficiency induces a multitude of responses aimed at improving the acquisition of Pi, including an increased density of root hairs. To understand the mechanisms involved in Pi deficiency-induced alterations of the root hair phenotype in Arabidopsis (Arabidopsis thaliana), we analyzed the patterning and length of root epidermal cells under control and Pi-deficient conditions in wild-type plants and in four mutants defective in the expression of master regulators of cell fate, CAPRICE (CPC), ENHANCER OF TRY AND CPC 1 (ETC1), WEREWOLF (WER) and SCRAMBLED (SCM). From this analysis we deduced that the longitudinal cell length of root epidermal cells is dependent on the correct perception of a positional signal ('cortical bias') in both control and Pi-deficient plants; mutants defective in the receptor of the signal, SCM, produced short cells characteristic of root hair-forming cells (trichoblasts). Simulating the effect of cortical bias on the time-evolving probability of cell fate supports a scenario in which a compromised positional signal delays the time point at which non-hair cells opt out the default trichoblast pathway, resulting in short, trichoblast-like non-hair cells. Collectively, our data show that Pi-deficient plants increase root hair density by the formation of shorter cells, resulting in a higher frequency of hairs per unit root length, and additional trichoblast cell fate assignment via increased expression of ETC1.

Positional Signaling and Expression of ENHANCER OF TRY AND CPC1 Are Tuned to Increase Root Hair Density in Response to Phosphate Deficiency in Arabidopsis thaliana

PubMed Central

Savage, Natasha; Yang, Thomas J. W.; Chen, Chung Ying; Lin, Kai-Lan; Monk, Nicholas A. M.; Schmidt, Wolfgang

2013-01-01

Phosphate (Pi) deficiency induces a multitude of responses aimed at improving the acquisition of Pi, including an increased density of root hairs. To understand the mechanisms involved in Pi deficiency-induced alterations of the root hair phenotype in Arabidopsis (Arabidopsis thaliana), we analyzed the patterning and length of root epidermal cells under control and Pi-deficient conditions in wild-type plants and in four mutants defective in the expression of master regulators of cell fate, CAPRICE (CPC), ENHANCER OF TRY AND CPC 1 (ETC1), WEREWOLF (WER) and SCRAMBLED (SCM). From this analysis we deduced that the longitudinal cell length of root epidermal cells is dependent on the correct perception of a positional signal (‘cortical bias’) in both control and Pi-deficient plants; mutants defective in the receptor of the signal, SCM, produced short cells characteristic of root hair-forming cells (trichoblasts). Simulating the effect of cortical bias on the time-evolving probability of cell fate supports a scenario in which a compromised positional signal delays the time point at which non-hair cells opt out the default trichoblast pathway, resulting in short, trichoblast-like non-hair cells. Collectively, our data show that Pi-deficient plants increase root hair density by the formation of shorter cells, resulting in a higher frequency of hairs per unit root length, and additional trichoblast cell fate assignment via increased expression of ETC1. PMID:24130712

LYSOPHOSPHATIDIC ACID INHIBITS CD8 T CELL ACTIVATION AND CONTROL OF TUMOR PROGRESSION

PubMed Central

Oda, Shannon K.; Strauch, Pamela; Fujiwara, Yuko; Al-Shami, Amin; Oravecz, Tamas; Tigyi, Gabor; Pelanda, Roberta; Torres, Raul M.

2013-01-01

CD8 T lymphocytes are able to eliminate nascent tumor cells through a process referred to as immune surveillance. However, multiple inhibitory mechanisms within the tumor microenvironment have been described that impede tumor rejection by CD8 T cells, including increased signaling by inhibitory receptors. Lysophosphatidic acid (LPA) is a bioactive lysophospholipid that has been shown repeatedly to promote diverse cellular processes benefiting tumorigenesis. Accordingly, the increased expression of LPA and LPA receptors is a common feature of diverse tumor cell lineages and can result in elevated systemic LPA levels. LPA is recognized by at least 6 distinct G-protein-coupled receptors and several of which are expressed by T cells, although the precise role of LPA signaling in CD8 T cell activation and function has not been defined. Here, we demonstrate that LPA signaling via the LPA5 receptor expressed by CD8 T cells suppresses antigen receptor signaling, cell activation and proliferation in vitro and in vivo. Importantly, in a mouse melanoma model tumor-specific CD8 T cells that are LPA5-deficient are able to control tumor growth significantly better than wild-type tumor-specific CD8 T cells. Together, these data suggest that the production of LPA by tumors serves not only in an autocrine manner to promote tumorigenesis but also as a mechanism to suppress adaptive immunity and highlights a potential novel target for cancer treatment. PMID:24455753

PDGF-BB induces PRMT1 expression through ERK1/2 dependent STAT1 activation and regulates remodeling in primary human lung fibroblasts.

PubMed

Sun, Qingzhu; Liu, Li; Mandal, Jyotshna; Molino, Antonio; Stolz, Daiana; Tamm, Michael; Lu, Shemin; Roth, Michael

2016-04-01

Tissue remodeling of sub-epithelial mesenchymal cells is a major pathology occurring in chronic obstructive pulmonary disease (COPD) and asthma. Fibroblasts, as a major source of interstitial connective tissue extracellular matrix, contribute to the fibrotic and inflammatory changes in these airways diseases. Previously, we described that protein arginine methyltransferase-1 (PRMT1) participates in airway remodeling in a rat model of pulmonary inflammation. In this study we investigated the mechanism by which PDGF-BB regulates PRMT1 in primary lung fibroblasts, isolated from human lung biopsies. Fibroblasts were stimulated with PDGF-BB for up-to 48h and the regulatory and activation of signaling pathways controlling PRMT1 expression were determined. PRMT1 was localized by immuno-histochemistry in human lung tissue sections and by immunofluorescence in isolated fibroblasts. PRMT1 activity was suppressed by the pan-PRMT inhibitor AMI1. ERK1/2 mitogen activated protein kinase (MAPK) was blocked by PD98059, p38 MAPK by SB203580, and STAT1 by small interference (si) RNA treatment. The results showed that PDGF-BB significantly increased PRMT1 expression after 1h lasting over 48h, through ERK1/2 MAPK and STAT1 signaling. The inhibition of ERK1/2 MAPK or of PRMT1 activity decreased PDGF-BB induced fibroblast proliferation, COX2 production, collagen-1A1 secretion, and fibronectin production. These findings suggest that PRMT1 is a central regulator of tissue remodeling and that the signaling sequence controlling its expression in primary human lung fibroblast is PDGF-ERK-STAT1. Therefore, PRMT1 presents a novel therapeutic and diagnostic target for the control of airway wall remodeling in chronic lung diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

Toll-Like Receptor 4 Is an Essential Upstream Regulator of On-Time Parturition and Perinatal Viability in Mice.

PubMed

Wahid, Hanan H; Dorian, Camilla L; Chin, Peck Yin; Hutchinson, Mark R; Rice, Kenner C; Olson, David M; Moldenhauer, Lachlan M; Robertson, Sarah A

2015-10-01

An inflammatory response is instrumental in the physiological process of parturition but the upstream signals initiating inflammation are undefined. Because endogenous ligands for Toll-like receptor 4 (TLR4) are released in late gestation, we hypothesized that on-time labor requires TLR4 signaling, to trigger a cytokine and leukocyte response and accelerate the parturition cascade. In pregnant TLR4-deficient (Tlr4-/-) mice, average gestation length was extended by 13 hours and increased perinatal mortality was seen compared with wild-type controls. Quantification of cytokine and uterine activation gene expression showed that late gestation induction of Il1b, Il6, Il12b, and Tnf expression seen in control placenta and fetal membranes was disrupted in Tlr4-/- mice, and accompanied by a transient delay in expression of uterine activation genes, including prostaglandin F receptor, oxytocin receptor, and connexin-43. Leukocyte populations were altered before birth in TLR4-deficient females, with fewer neutrophils and macrophages in the placenta, and fewer dendritic cells and more regulatory T cells in the myometrium. Administration of TLR4 ligand lipopolysaccharide to pregnant wild-type mice induced cytokine expression and fetal loss, whereas Tlr4-/- pregnancies were protected. The small molecule TLR4 antagonist (+)-naloxone increased mean duration of gestation by 16 hours in wild-type mice. Collectively, these data demonstrate that TLR4 is a key upstream regulator of the inflammatory response acting to drive uterine activation and control the timing of labor. Because causal pathways for term and preterm labor converge with TLR4, interventions to manipulate TLR4 signaling may have therapeutic utility for women at risk of preterm labor, or in postterm pregnancy.

Toll-Like Receptor 4 Is an Essential Upstream Regulator of On-Time Parturition and Perinatal Viability in Mice

PubMed Central

Wahid, Hanan H.; Dorian, Camilla L.; Chin, Peck Yin; Hutchinson, Mark R.; Rice, Kenner C.; Olson, David M.; Moldenhauer, Lachlan M.

2015-01-01

An inflammatory response is instrumental in the physiological process of parturition but the upstream signals initiating inflammation are undefined. Because endogenous ligands for Toll-like receptor 4 (TLR4) are released in late gestation, we hypothesized that on-time labor requires TLR4 signaling, to trigger a cytokine and leukocyte response and accelerate the parturition cascade. In pregnant TLR4-deficient (Tlr4−/−) mice, average gestation length was extended by 13 hours and increased perinatal mortality was seen compared with wild-type controls. Quantification of cytokine and uterine activation gene expression showed that late gestation induction of Il1b, Il6, Il12b, and Tnf expression seen in control placenta and fetal membranes was disrupted in Tlr4−/− mice, and accompanied by a transient delay in expression of uterine activation genes, including prostaglandin F receptor, oxytocin receptor, and connexin-43. Leukocyte populations were altered before birth in TLR4-deficient females, with fewer neutrophils and macrophages in the placenta, and fewer dendritic cells and more regulatory T cells in the myometrium. Administration of TLR4 ligand lipopolysaccharide to pregnant wild-type mice induced cytokine expression and fetal loss, whereas Tlr4−/− pregnancies were protected. The small molecule TLR4 antagonist (+)-naloxone increased mean duration of gestation by 16 hours in wild-type mice. Collectively, these data demonstrate that TLR4 is a key upstream regulator of the inflammatory response acting to drive uterine activation and control the timing of labor. Because causal pathways for term and preterm labor converge with TLR4, interventions to manipulate TLR4 signaling may have therapeutic utility for women at risk of preterm labor, or in postterm pregnancy. PMID:26151355

Inhibition of Thrombopoietin/Mpl Signaling in Adult Hematopoiesis Identifies New Candidates for Hematopoietic Stem Cell Maintenance.

PubMed

Kohlscheen, Saskia; Wintterle, Sabine; Schwarzer, Adrian; Kamp, Christel; Brugman, Martijn H; Breuer, Daniel C; Büsche, Guntram; Baum, Christopher; Modlich, Ute

2015-01-01

Thrombopoietin (Thpo) signals via its receptor Mpl and regulates megakaryopoiesis, hematopoietic stem cell (HSC) maintenance and post-transplant expansion. Mpl expression is tightly controlled and deregulation of Thpo/Mpl-signaling is linked to hematological disorders. Here, we constructed an intracellular-truncated, signaling-deficient Mpl protein which is presented on the cell surface (dnMpl). The transplantation of bone marrow cells retrovirally transduced to express dnMpl into wildtype mice induced thrombocytopenia, and a progressive loss of HSC. The aplastic BM allowed the engraftment of a second BM transplant without further conditioning. Functional analysis of the truncated Mpl in vitro and in vivo demonstrated no internalization after Thpo binding and the inhibition of Thpo/Mpl-signaling in wildtype cells due to dominant-negative (dn) effects by receptor competition with wildtype Mpl for Thpo binding. Intracellular inhibition of Mpl could be excluded as the major mechanism by the use of a constitutive-dimerized dnMpl. To further elucidate the molecular changes induced by Thpo/Mpl-inhibition on the HSC-enriched cell population in the BM, we performed gene expression analysis of Lin-Sca1+cKit+ (LSK) cells isolated from mice transplanted with dnMpl transduced BM cells. The gene expression profile supported the exhaustion of HSC due to increased cell cycle progression and identified new and known downstream effectors of Thpo/Mpl-signaling in HSC (namely TIE2, ESAM1 and EPCR detected on the HSC-enriched LSK cell population). We further compared gene expression profiles in LSK cells of dnMpl mice with human CD34+ cells of aplastic anemia patients and identified similar deregulations of important stemness genes in both cell populations. In summary, we established a novel way of Thpo/Mpl inhibition in the adult mouse and performed in depth analysis of the phenotype including gene expression profiling.

Inhibition of Thrombopoietin/Mpl Signaling in Adult Hematopoiesis Identifies New Candidates for Hematopoietic Stem Cell Maintenance

PubMed Central

Schwarzer, Adrian; Kamp, Christel; Brugman, Martijn H.; Breuer, Daniel C.; Büsche, Guntram; Baum, Christopher; Modlich, Ute

2015-01-01

Thrombopoietin (Thpo) signals via its receptor Mpl and regulates megakaryopoiesis, hematopoietic stem cell (HSC) maintenance and post-transplant expansion. Mpl expression is tightly controlled and deregulation of Thpo/Mpl-signaling is linked to hematological disorders. Here, we constructed an intracellular-truncated, signaling-deficient Mpl protein which is presented on the cell surface (dnMpl). The transplantation of bone marrow cells retrovirally transduced to express dnMpl into wildtype mice induced thrombocytopenia, and a progressive loss of HSC. The aplastic BM allowed the engraftment of a second BM transplant without further conditioning. Functional analysis of the truncated Mpl in vitro and in vivo demonstrated no internalization after Thpo binding and the inhibition of Thpo/Mpl-signaling in wildtype cells due to dominant-negative (dn) effects by receptor competition with wildtype Mpl for Thpo binding. Intracellular inhibition of Mpl could be excluded as the major mechanism by the use of a constitutive-dimerized dnMpl. To further elucidate the molecular changes induced by Thpo/Mpl-inhibition on the HSC-enriched cell population in the BM, we performed gene expression analysis of Lin-Sca1+cKit+ (LSK) cells isolated from mice transplanted with dnMpl transduced BM cells. The gene expression profile supported the exhaustion of HSC due to increased cell cycle progression and identified new and known downstream effectors of Thpo/Mpl-signaling in HSC (namely TIE2, ESAM1 and EPCR detected on the HSC-enriched LSK cell population). We further compared gene expression profiles in LSK cells of dnMpl mice with human CD34+ cells of aplastic anemia patients and identified similar deregulations of important stemness genes in both cell populations. In summary, we established a novel way of Thpo/Mpl inhibition in the adult mouse and performed in depth analysis of the phenotype including gene expression profiling. PMID:26147434

Reduced TCR signaling potential impairs negative selection but does not result in autoimmune disease

PubMed Central

Hwang, SuJin; Song, Ki-Duk; Lesourne, Renaud; Lee, Jan; Pinkhasov, Julia; Li, LiQi; El-Khoury, Dalal

2012-01-01

Negative selection and regulatory T (T reg) cell development are two thymus-dependent processes necessary for the enforcement of self-tolerance, and both require high-affinity interactions between the T cell receptor (TCR) and self-ligands. However, it remains unclear if they are similarly impacted by alterations in TCR signaling potential. We generated a knock-in allele (6F) of the TCR ζ chain gene encoding a mutant protein lacking signaling capability whose expression is controlled by endogenous ζ regulatory sequences. Although negative selection was defective in 6F/6F mice, leading to the survival of autoreactive T cells, 6F/6F mice did not develop autoimmune disease. We found that 6F/6F mice generated increased numbers of thymus-derived T reg cells. We show that attenuation of TCR signaling potential selectively impacts downstream signaling responses and that this differential effect favors Foxp3 expression and T reg cell lineage commitment. These results identify a potential compensatory pathway for the enforcement of immune tolerance in response to defective negative selection caused by reduced TCR signaling capability. PMID:22945921

Essential Roles of Epithelial Bone Morphogenetic Protein Signaling During Prostatic Development

PubMed Central

Omori, Akiko; Miyagawa, Shinichi; Ogino, Yukiko; Harada, Masayo; Ishii, Kenichiro; Sugimura, Yoshiki; Ogino, Hajime; Nakagata, Naomi

2014-01-01

Prostate is a male sex-accessory organ. The prostatic epithelia consist primarily of basal and luminal cells that differentiate from embryonic urogenital sinus epithelia. Prostate tumors are believed to originate in the basal and luminal cells. However, factors that promote normal epithelial differentiation have not been well elucidated, particularly for bone morphogenetic protein (Bmp) signaling. This study shows that Bmp signaling prominently increases during prostatic differentiation in the luminal epithelia, which is monitored by the expression of phosphorylated Smad1/5/8. To elucidate the mechanism of epithelial differentiation and the function of Bmp signaling during prostatic development, conditional male mutant mouse analysis for the epithelial-specific Bmp receptor 1a (Bmpr1a) was performed. We demonstrate that Bmp signaling is indispensable for luminal cell maturation, which regulates basal cell proliferation. Expression of the prostatic epithelial regulatory gene Nkx3.1 was significantly reduced in the Bmpr1a mutants. These results indicate that Bmp signaling is a key factor for prostatic epithelial differentiation, possibly by controlling the prostatic regulatory gene Nkx3.1. PMID:24731097

A novel DLX3-PKC integrated signaling network drives keratinocyte differentiation.

PubMed

Palazzo, Elisabetta; Kellett, Meghan D; Cataisson, Christophe; Bible, Paul W; Bhattacharya, Shreya; Sun, Hong-Wei; Gormley, Anna C; Yuspa, Stuart H; Morasso, Maria I

2017-04-01

Epidermal homeostasis relies on a well-defined transcriptional control of keratinocyte proliferation and differentiation, which is critical to prevent skin diseases such as atopic dermatitis, psoriasis or cancer. We have recently shown that the homeobox transcription factor DLX3 and the tumor suppressor p53 co-regulate cell cycle-related signaling and that this mechanism is functionally involved in cutaneous squamous cell carcinoma development. Here we show that DLX3 expression and its downstream signaling depend on protein kinase C α (PKCα) activity in skin. We found that following 12-O-tetradecanoyl-phorbol-13-acetate (TPA) topical treatment, DLX3 expression is significantly upregulated in the epidermis and keratinocytes from mice overexpressing PKCα by transgenic targeting (K5-PKCα), resulting in cell cycle block and terminal differentiation. Epidermis lacking DLX3 (DLX3cKO), which is linked to the development of a DLX3-dependent epidermal hyperplasia with hyperkeratosis and dermal leukocyte recruitment, displays enhanced PKCα activation, suggesting a feedback regulation of DLX3 and PKCα. Of particular significance, transcriptional activation of epidermal barrier, antimicrobial peptide and cytokine genes is significantly increased in DLX3cKO skin and further increased by TPA-dependent PKC activation. Furthermore, when inhibiting PKC activity, we show that epidermal thickness, keratinocyte proliferation and inflammatory cell infiltration are reduced and the PKC-DLX3-dependent gene expression signature is normalized. Independently of PKC, DLX3 expression specifically modulates regulatory networks such as Wnt signaling, phosphatase activity and cell adhesion. Chromatin immunoprecipitation sequencing analysis of primary suprabasal keratinocytes showed binding of DLX3 to the proximal promoter regions of genes associated with cell cycle regulation, and of structural proteins and transcription factors involved in epidermal differentiation. These results indicate that Dlx3 potentially regulates a set of crucial genes necessary during the epidermal differentiation process. Altogether, we demonstrate the existence of a robust DLX3-PKCα signaling pathway in keratinocytes that is crucial to epidermal differentiation control and cutaneous homeostasis.

A novel DLX3–PKC integrated signaling network drives keratinocyte differentiation

PubMed Central

Palazzo, Elisabetta; Kellett, Meghan D; Cataisson, Christophe; Bible, Paul W; Bhattacharya, Shreya; Sun, Hong-wei; Gormley, Anna C; Yuspa, Stuart H; Morasso, Maria I

2017-01-01

Epidermal homeostasis relies on a well-defined transcriptional control of keratinocyte proliferation and differentiation, which is critical to prevent skin diseases such as atopic dermatitis, psoriasis or cancer. We have recently shown that the homeobox transcription factor DLX3 and the tumor suppressor p53 co-regulate cell cycle-related signaling and that this mechanism is functionally involved in cutaneous squamous cell carcinoma development. Here we show that DLX3 expression and its downstream signaling depend on protein kinase C α (PKCα) activity in skin. We found that following 12-O-tetradecanoyl-phorbol-13-acetate (TPA) topical treatment, DLX3 expression is significantly upregulated in the epidermis and keratinocytes from mice overexpressing PKCα by transgenic targeting (K5-PKCα), resulting in cell cycle block and terminal differentiation. Epidermis lacking DLX3 (DLX3cKO), which is linked to the development of a DLX3-dependent epidermal hyperplasia with hyperkeratosis and dermal leukocyte recruitment, displays enhanced PKCα activation, suggesting a feedback regulation of DLX3 and PKCα. Of particular significance, transcriptional activation of epidermal barrier, antimicrobial peptide and cytokine genes is significantly increased in DLX3cKO skin and further increased by TPA-dependent PKC activation. Furthermore, when inhibiting PKC activity, we show that epidermal thickness, keratinocyte proliferation and inflammatory cell infiltration are reduced and the PKC-DLX3-dependent gene expression signature is normalized. Independently of PKC, DLX3 expression specifically modulates regulatory networks such as Wnt signaling, phosphatase activity and cell adhesion. Chromatin immunoprecipitation sequencing analysis of primary suprabasal keratinocytes showed binding of DLX3 to the proximal promoter regions of genes associated with cell cycle regulation, and of structural proteins and transcription factors involved in epidermal differentiation. These results indicate that Dlx3 potentially regulates a set of crucial genes necessary during the epidermal differentiation process. Altogether, we demonstrate the existence of a robust DLX3–PKCα signaling pathway in keratinocytes that is crucial to epidermal differentiation control and cutaneous homeostasis. PMID:28186503

iTRAQ proteomics analysis reveals that PI3K is highly associated with bupivacaine-induced neurotoxicity pathways.

PubMed

Zhao, Wei; Liu, Zhongjie; Yu, Xujiao; Lai, Luying; Li, Haobo; Liu, Zipeng; Li, Le; Jiang, Shan; Xia, Zhengyuan; Xu, Shi-yuan

2016-02-01

Bupivacaine, a commonly used local anesthetic, has potential neurotoxicity through diverse signaling pathways. However, the key mechanism of bupivacaine-induced neurotoxicity remains unclear. Cultured human SH-SY5Y neuroblastoma cells were treated (bupivacaine) or untreated (control) with bupivacaine for 24 h. Compared to the control group, bupivacaine significantly increased cyto-inhibition, cellular reactive oxygen species, DNA damage, mitochondrial injury, apoptosis (increased TUNEL-positive cells, cleaved caspase 3, and Bcl-2/Bax), and activated autophagy (enhanced LC3II/LC3I ratio). To explore changes in protein expression and intercommunication among the pathways involved in bupivacaine-induced neurotoxicity, an 8-plex iTRAQ proteomic technique and bioinformatics analysis were performed. Compared to the control group, 241 differentially expressed proteins were identified, of which, 145 were up-regulated and 96 were down-regulated. Bioinformatics analysis of the cross-talk between the significant proteins with altered expression in bupivacaine-induced neurotoxicity indicated that phosphatidyl-3-kinase (PI3K) was the most frequently targeted protein in each of the interactions. We further confirmed these results by determining the downstream targets of the identified signaling pathways (PI3K, Akt, FoxO1, Erk, and JNK). In conclusion, our study demonstrated that PI3K may play a central role in contacting and regulating the signaling pathways that contribute to bupivacaine-induced neurotoxicity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Central insulin-mediated regulation of hepatic glucose production [Review].

PubMed

Inoue, Hiroshi

2016-01-01

Insulin controls hepatic glucose production (HGP) and maintains glucose homeostasis through the direct action of hepatic insulin receptors, as well as the indirect action of insulin receptors in the central nervous system. Insulin acts on insulin receptors in the hypothalamic arcuate nucleus, activates ATP-sensitive potassium channels in a phosphoinositide 3-kinase (PI3K)-dependent manner, induces hyperpolarization of the hypothalamic neurons, and regulates HGP via the vagus nerve. In the liver, central insulin action augments IL-6 expression in Kupffer cells and activates STAT3 transcription factors in hepatocytes. Activated STAT3 suppresses the gene expression of gluconeogenic enzymes, thereby reducing HGP. It has become evident that nutrients such as glucose, fatty acids, and amino acids act upon the hypothalamus together with insulin, affecting HGP. On the other hand, HGP control by central insulin action is impeded in obesity and impeded by insulin resistance due to disturbance of PI3K signaling and inflammation in the hypothalamus or inhibition of STAT3 signaling in the liver. Although the mechanism of control of hepatic gluconeogenic gene expression by central insulin action is conserved across species, its importance in human glucose metabolism has not been made entirely clear and its elucidation is anticipated in the future.

Leptin controls ketone body utilization in hypothalamic neuron.

PubMed

Narishima, Ryota; Yamasaki, Masahiro; Hasegawa, Shinya; Yoshida, Saki; Tanaka, Shinya; Fukui, Tetsuya

2011-03-03

Leptin is an appetite-controlling peptide secreted from adipose tissue. Previously, we showed that the gene expression of acetoacetyl-CoA synthetase (AACS), the ketone body-utilizing enzyme for lipid synthesis, was suppressed by leptin deficiency-induced obesity in white adipose tissue. In this study, to clarify the effects of leptin on ketone body utilization in the central nervous system, we examined the effects of leptin signaling on AACS expression. In situ hybridization analysis of ob/ob and db/db mice revealed that AACS mRNA level was reduced by leptin deficiency in the arcuate nucleus (Arc) and ventromedial hypothalamic nucleus (VMH) in hypothalamus but not in other brain regions. Moreover, AACS mRNA level was increased by leptin treatment both in primary cultured neural cells and in N41 neural-like cells. In N41 cells, AACS level was decreased by AMPK inducer but increased by AMPK inhibitor. These results suggest that the up-regulation of AACS expression by leptin is due to the suppression of AMPK activity via neural leptin signaling and that the deficiency of this regulation may be responsible for neurological disorders in central appetite control. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Expression of multiple sexual signals by fathers and sons in the East-Mediterranean barn swallow: are advertising strategies heritable?

PubMed

Vortman, Yoni; Safran, Rebecca J; Reiner Brodetzki, Tali; Dor, Roi; Lotem, Arnon

2015-01-01

The level of expression of sexually selected traits is generally determined by genes, environment and their interaction. In species that use multiple sexual signals which may be costly to produce, investing in the expression of one sexual signal may limit the expression of the other, favoring the evolution of a strategy for resource allocation among signals. As a result, even when the expression of sexual signals is condition dependent, the relative level of expression of each signal may be heritable. We tested this hypothesis in the East-Mediterranean barn swallow (Hirundo rustica transitiva), in which males have been shown to express two uncorrelated sexual signals: red-brown ventral coloration, and long tail streamers. We show that variation in both signals may partially be explained by age, as well as by paternal origin (genetic father-son regressions), but that the strongest similarity between fathers and sons is the relative allocation towards one trait or the other (relative expression index), rather than the expression of the traits themselves. These results suggest that the expression of one signal is not independent of the other, and that genetic strategies for resource allocation among sexual signals may be selected for during the evolution of multiple sexual signals.

Expression of Multiple Sexual Signals by Fathers and Sons in the East-Mediterranean Barn Swallow: Are Advertising Strategies Heritable?

PubMed Central

Vortman, Yoni; Safran, Rebecca J.; Reiner Brodetzki, Tali; Dor, Roi; Lotem, Arnon

2015-01-01

The level of expression of sexually selected traits is generally determined by genes, environment and their interaction. In species that use multiple sexual signals which may be costly to produce, investing in the expression of one sexual signal may limit the expression of the other, favoring the evolution of a strategy for resource allocation among signals. As a result, even when the expression of sexual signals is condition dependent, the relative level of expression of each signal may be heritable. We tested this hypothesis in the East-Mediterranean barn swallow (Hirundo rustica transitiva), in which males have been shown to express two uncorrelated sexual signals: red-brown ventral coloration, and long tail streamers. We show that variation in both signals may partially be explained by age, as well as by paternal origin (genetic father-son regressions), but that the strongest similarity between fathers and sons is the relative allocation towards one trait or the other (relative expression index), rather than the expression of the traits themselves. These results suggest that the expression of one signal is not independent of the other, and that genetic strategies for resource allocation among sexual signals may be selected for during the evolution of multiple sexual signals. PMID:25679206

Identification of Hedgehog signaling outcomes in mouse testis development using a hanging drop-culture system.

PubMed

Szczepny, Anette; Hogarth, Cathryn A; Young, Julia; Loveland, Kate L

2009-02-01

The Hedgehog (Hh) signaling pathway affects fetal testis growth. Recently, we described the dynamic cellular production of Hh signaling pathway components in juvenile and adult rodent testes. The Hh signaling is understood to regulate cord formation in the fetal testis, but minimal knowledge exists regarding how Hh signaling impacts the postnatal testis. To investigate this, we employed hanging drop cultures, which are used routinely in embryoid body formation. This approach has the advantage of using small media volume, and we examined its suitability for short-term culture of both murine embryonic gonads and adult testis tubules. The effects of cyclopamine, a specific Hh signaling inhibitor, were examined following culture of Embryonic Day 11.5 urogenital ridges (as control) and adult seminiferous tubule fragments for 24-48 h using histological, cell proliferation, and gene expression analyses. Cultured embryonic testes displayed generally normal cord structure, anti-Müllerian hormone (Amh) expression, and cell proliferation; known Hh target gene expression (Gli1, osteopontin, official symbol Spp1, and Amh) was altered in response to cyclopamine. Cultured adult tubules exhibited some loss of seminiferous epithelium organization over 48 h. Spermatogonia continued to proliferate, however, and no significant loss of viability was noted overall. Addition of cyclopamine significantly affected levels of Gli1, Igfbp6, Ccnd2 (cyclin D2), Ccnb1 (cyclin B1), Spp1, Kit, and Amh mRNAs; these genes have been shown previously to be expressed in Sertoli and germ cells. These novel results identify Hh target genes in the testis and demonstrate this signaling pathway likely affects cell survival and differentiation in the context of normal adult testis.

Identification of Hedgehog Signaling Outcomes in Mouse Testis Development Using a Hanging Drop-Culture System1

PubMed Central

Szczepny, Anette; Hogarth, Cathryn A.; Young, Julia; Loveland, Kate L.

2008-01-01

The Hedgehog (Hh) signaling pathway affects fetal testis growth. Recently, we described the dynamic cellular production of Hh signaling pathway components in juvenile and adult rodent testes. The Hh signaling is understood to regulate cord formation in the fetal testis, but minimal knowledge exists regarding how Hh signaling impacts the postnatal testis. To investigate this, we employed hanging drop cultures, which are used routinely in embryoid body formation. This approach has the advantage of using small media volume, and we examined its suitability for short-term culture of both murine embryonic gonads and adult testis tubules. The effects of cyclopamine, a specific Hh signaling inhibitor, were examined following culture of Embryonic Day 11.5 urogenital ridges (as control) and adult seminiferous tubule fragments for 24–48 h using histological, cell proliferation, and gene expression analyses. Cultured embryonic testes displayed generally normal cord structure, anti-Müllerian hormone (Amh) expression, and cell proliferation; known Hh target gene expression (Gli1, osteopontin, official symbol Spp1, and Amh) was altered in response to cyclopamine. Cultured adult tubules exhibited some loss of seminiferous epithelium organization over 48 h. Spermatogonia continued to proliferate, however, and no significant loss of viability was noted overall. Addition of cyclopamine significantly affected levels of Gli1, Igfbp6, Ccnd2 (cyclin D2), Ccnb1 (cyclin B1), Spp1, Kit, and Amh mRNAs; these genes have been shown previously to be expressed in Sertoli and germ cells. These novel results identify Hh target genes in the testis and demonstrate this signaling pathway likely affects cell survival and differentiation in the context of normal adult testis. PMID:18843087

Melatonin and associated signaling pathways that control normal breast epithelium and breast cancer.

PubMed

Hill, Steven M; Blask, David E; Xiang, Shulin; Yuan, Lin; Mao, Lulu; Dauchy, Robert T; Dauchy, Erin M; Frasch, Tripp; Duplesis, Tamika

2011-09-01

This review article discusses recent work on the melatonin-mediated circadian regulation and integration of molecular and metabolic signaling mechanisms involved in human breast cancer growth and the associated consequences of circadian disruption by exposure to light-at-night (LAN). The anti-proliferative effects of the circadian melatonin signal are, in general, mediated through mechanisms involving the activation of MT(1) melatonin receptors expressed in human breast cancer cell lines and xenografts. In estrogen receptor-positive (ERα+) human breast cancer cells, melatonin suppresses both ERα mRNA expression and estrogen-induced transcriptional activity of the ERα via MT(1)-induced activation of G(αi2) signaling and reduction of cAMP levels. Melatonin also regulates the transcriptional activity of additional members of the nuclear receptor super-family, enzymes involved in estrogen metabolism, and the expression of core clock and clock-related genes. The anti-invasive/anti-metastatic actions of melatonin involve the blockade of p38 phosphorylation and matrix metalloproteinase expression. Melatonin also inhibits the growth of human breast cancer xenografts via MT(1)-mediated suppression of cAMP leading to a blockade of linoleic acid (LA) uptake and its metabolism to the mitogenic signaling molecule 13-hydroxyoctadecadienoic acid (13-HODE). Down-regulation of 13-HODE reduces the activation of growth factor pathways supporting cell proliferation and survival. Finally, studies in both rats and humans indicate that light-at-night (LAN) induced circadian disruption of the nocturnal melatonin signal activates human breast cancer growth, metabolism, and signaling, providing the strongest mechanistic support, thus far, for epidemiological studies demonstrating the elevated breast cancer risk in night shift workers and other individuals increasingly exposed to LAN.

Axonal/Glial Upregulation of EphB/ephrin-B Signaling in Mouse Experimental Ocular Hypertension

PubMed Central

Tran, Tony; Sretavan, David

2010-01-01

Purpose. To use a laser-induced ocular hypertension (LIOH) mouse model to examine the optic nerve head (ONH) expression of EphB/ephrin-B, previously shown to be upregulated in glaucomatous DBA/2J mice. To relate ephrin-B reverse signaling with states of axonal response to disease. Methods. LIOH was induced unilaterally in CD-1 mice by laser photocoagulation of limbal and episcleral veins. Intraocular pressure (IOP) was measured with a tonometer. EphB/ephrin-B mRNA expression was assessed by in situ hybridization on eyecup cryosections and real-time PCR. Cell specific markers were used to identify the cellular origin of EphB/ephrin-B expression. Activation of ephrin-B signaling was investigated with a phosphospecific antibody on cryosections and retinal whole-mounts. Results. Upregulation of EphB/ephrin-B expression occurred early within a day of IOP elevation. A transient increase of phosphorylation-dependent ephrin-B (pEB) reverse signaling was observed in ONH axons, microglia, and some astrocytes. Morphologically unaffected retinal ganglion cell (RGC) axons differed from axons with reactive aberrant trajectories by exhibiting increased pEB activation, whereas pEB levels in morphologically affected axons were comparable to those of controls. Conclusions. An Eph-ephrin signaling network is activated at the ONH after LIOH in CD-1 mice, either before or coincident with the initial morphologic signs of RGC axon damage reported previously. Of note, ephrin-B reverse signaling was transiently upregulated in RGC axons at the ONH early in their response to IOP elevation but was downregulated in axons that had been damaged by glaucomatous injury and exhibited aberrant trajectories. Ephrin-B reverse signaling may mark RGC axons for damage or confer a protective advantage against injury. PMID:19815726

Assessing the osteoblast transcriptome in a model of enhanced bone formation due to constitutive Gs-G protein signaling in osteoblasts

PubMed Central

Wattanachanya, Lalita; Wang, Liping; Millard, Susan M.; Lu, Wei-Dar; O’Carroll, Dylan; Hsiao, Edward C.; Conklin, Bruce R.; Nissenson, Robert A.

2015-01-01

G protein–coupled receptor (GPCR) signaling in osteoblasts (OBs) is an important regulator of bone formation. We previously described a mouse model expressing Rs1, an engineered constitutively active Gs-coupled GPCR, under the control of the 2.3-kb Col I promoter. These mice showed a dramatic age-dependent increase in trabecular bone of femurs. Here, we further evaluated the effects of enhanced Gs signaling in OBs on intramembranous bone formation by examining calvariae of 1- and 9-week-old Col1(2.3)/Rs1 mice and characterized the in vivo gene expression specifically occurring in osteoblasts with activated Gs G protein–coupled receptor signaling, at the cellular level rather than in a whole bone. Rs1 calvariae displayed a dramatic increase in bone volume with partial loss of cortical structure. By immunohistochemistry, Osterix was detected in cells throughout the inter-trabecular space while Osteocalcin was expressed predominantly in cells along bone surfaces, suggesting the role of paracrine mediators secreted from OBs driven by 2.3-kb Col I promoter could influence early OB commitment, differentiation, and/or proliferation. Gene expression analysis of calvarial OBs revealed that genes affected by Rs1 signaling include those encoding proteins important for cell differentiation, cytokines and growth factors, angiogenesis, coagulation, and energy metabolism. The set of Gs-GPCRs and other GPCRs that may contribute to the observed skeletal phenotype and candidate paracrine mediators of the effect of Gs signaling in OBs were also determined. Our results identify novel detailed in vivo cellular changes of the anabolic response of the skeleton to Gs signaling in mature OBs. PMID:25704759

[Effect of Inhibiting and Activating Wnt Signalling Pathway on NSC67657-inducing Monocytic Differentiation of HL-60 Cells].

PubMed

Wang, Wei-Jia; Zhang, Xiu-Ming; Zhang, Yan; Wang, Jin-Shu

2016-04-01

To investigate the effect of inhibiting and activating Wnt signalling pathway on monocyte differentiation of HL-60 cells induced with a new steroidal drug NSC67657 and its possible mechamism. The HL-60 cells were treated with 5, 10 and 20 µmol/L XAV-939 (inhibitor of Wnt signalling pathway) for 3 days, and with 10, 20 and 30 mmol/L LiCl (activator of Wnt signalling pathway) for 1 day; the expression levels of down-stream genes and proteins of Wnt signolling pathway were detected by RT-PCR and Western blot, respectively; the expression of cell surface differentiation antigen CD14 and early apoptosis of HL-60 cells was detected by flow cytometry, moreover the most suitable concentration of Wnt inhibitor and activator for HL-60 cells was determined. Then the HL-60 cells with inhibited and activated Wnt pathway were treated with NSC67657 of 10 µmol/L for 3 days; the expression levels of CD14 and down-stream target proteins of Wnt signalling pathway in blank control (culture mediam) group, simple NSC67657-treated group, NSC67657 combined with inhibitor group and NSC67657 combined activator group were compared and analyzed. 20 µmol/L XAV-939 and 20 mmol/L LiCl could effectively inhibit and activate Wnt signalling pathway of HL-60 cells respectively, could significantly down- and up-regulate the expression of cyclinD1, TCF1 and c-Jun genes (P < 0.05) and proteins (P < 0.05); moreover, the number of CD10(+) HL-60 cells in these conditions was below 1%, no early apoptosis of HL-60 cells was found. In the simple NSC67657-treated groups, the expression of cyclinD1, TCF1 and c-Jun proteins was down-regulated (P < 0.05), and the percentage of CD14(+) HL-60 cells accounted for 62.13 ± 9.44; after the HL-60 cells were treated with XAV-939, the NSC67657 could more significantly down-regulate the expression of cyclinD1, TCF1 and c-Jun proteins and the percentage of CD14(+) HL-60 cell accounted for 84.17 ± 5.39%, as compared with simple NSC67657-treated group; as compared with blank controls group, the expression of cyclinD1, TCF1 and c-Jun proteins was more obviously down-regulated and the percentage of CD14(+) HL-60 cells decreased to 33.99 ± 8.37% in NSC67657 combined LiC1 streated group, but which were higher than those in simple NSC67657-treated group (P < 0.05). 20 µmol/L XAV-939 and 20 mmol/L LiCl as effective inhabitor and activator of Wnt signalling pathway respectively can significantly down- and up-regulate the expression of Wnt down-stream pathway target genes and proteins. The influence of XAV-939 and LiC1 on differentiation of HL-60 cells induced by NSC67657 suggests that Wnt signalling pathway plays a key role in monocyte differentiction of HL-60 cells induced by NSC67657.

Calcineurin/NFAT signaling in osteoblasts regulates bone mass.

PubMed

Winslow, Monte M; Pan, Minggui; Starbuck, Michael; Gallo, Elena M; Deng, Lei; Karsenty, Gerard; Crabtree, Gerald R

2006-06-01

Development and repair of the vertebrate skeleton requires the precise coordination of bone-forming osteoblasts and bone-resorbing osteoclasts. In diseases such as osteoporosis, bone resorption dominates over bone formation, suggesting a failure to harmonize osteoclast and osteoblast function. Here, we show that mice expressing a constitutively nuclear NFATc1 variant (NFATc1(nuc)) in osteoblasts develop high bone mass. NFATc1(nuc) mice have massive osteoblast overgrowth, enhanced osteoblast proliferation, and coordinated changes in the expression of Wnt signaling components. In contrast, viable NFATc1-deficient mice have defects in skull bone formation in addition to impaired osteoclast development. NFATc1(nuc) mice have increased osteoclastogenesis despite normal levels of RANKL and OPG, indicating that an additional NFAT-regulated mechanism influences osteoclastogenesis in vivo. Calcineurin/NFATc signaling in osteoblasts controls the expression of chemoattractants that attract monocytic osteoclast precursors, thereby coupling bone formation and bone resorption. Our results indicate that NFATc1 regulates bone mass by functioning in both osteoblasts and osteoclasts.

Glycogen synthase kinase 3 has a limited role in cell cycle regulation of cyclin D1 levels.

PubMed

Yang, Ke; Guo, Yang; Stacey, William C; Harwalkar, Jyoti; Fretthold, Jonathan; Hitomi, Masahiro; Stacey, Dennis W

2006-08-30

The expression level of cyclin D1 plays a vital role in the control of proliferation. This protein is reported to be degraded following phosphorylation by glycogen synthase kinase 3 (GSK3) on Thr-286. We recently showed that phosphorylation of Thr-286 is responsible for a decline in cyclin D1 levels during S phase, an event required for efficient DNA synthesis. These studies were undertaken to test the possibility that phosphorylation by GSK3 is responsible for the S phase specific decline in cyclin D1 levels, and that this event is regulated by the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway which controls GSK3. We found, however, that neither PI3K, AKT, GSK3, nor proliferative signaling activity in general is responsible for the S phase decline in cyclin D1 levels. In fact, the activity of these signaling kinases does not vary through the cell cycle of proliferating cells. Moreover, we found that GSK3 activity has little influence over cyclin D1 expression levels during any cell cycle phase. Inhibition of GSK3 activity by siRNA, LiCl, or other chemical inhibitors failed to influence cyclin D1 phosphorylation on Thr-286, even though LiCl efficiently blocked phosphorylation of beta-catenin, a known substrate of GSK3. Likewise, the expression of a constitutively active GSK3 mutant protein failed to influence cyclin D1 phosphorylation or total protein expression level. Because we were unable to identify any proliferative signaling molecule or pathway which is regulated through the cell cycle, or which is able to influence cyclin D1 levels, we conclude that the suppression of cyclin D1 levels during S phase is regulated by cell cycle position rather than signaling activity. We propose that this mechanism guarantees the decline in cyclin D1 levels during each S phase; and that in so doing it reduces the likelihood that simple over expression of cyclin D1 can lead to uncontrolled cell growth.

Building the Vertebrate Spine

NASA Astrophysics Data System (ADS)

Pourquié, Olivier

2008-03-01

The vertebrate body can be subdivided along the antero-posterior (AP) axis into repeated structures called segments. This periodic pattern is established during embryogenesis by the somitogenesis process. Somites are generated in a rhythmic fashion from the paraxial mesoderm and subsequently differentiate to give rise to the vertebrae and skeletal muscles of the body. Somite formation involves an oscillator-the segmentation clock-whose periodic signal is converted into the periodic array of somite boundaries. This clock drives the dynamic expression of cyclic genes in the presomitic mesoderm and requires Notch and Wnt signaling. Microarray studies of the mouse presomitic mesoderm transcriptome reveal that the segmentation clock drives the periodic expression of a large network of cyclic genes involved in cell signaling. Mutually exclusive activation of the Notch/FGF and Wnt pathways during each cycle suggests that coordinated regulation of these three pathways underlies the clock oscillator. In humans, mutations in the genes associated to the function of this oscillator such as Dll3 or Lunatic Fringe result in abnormal segmentation of the vertebral column such as those seen in congenital scoliosis. Whereas the segmentation clock is thought to set the pace of vertebrate segmentation, the translation of this pulsation into the reiterated arrangement of segment boundaries along the AP axis involves dynamic gradients of FGF and Wnt signaling. The FGF signaling gradient is established based on an unusual mechanism involving mRNA decay which provides an efficient means to couple the spatio-temporal activation of segmentation to the posterior elongation of the embryo. Another striking aspect of somite production is the strict bilateral symmetry of the process. Retinoic acid was shown to control aspects of this coordination by buffering destabilizing effects from the embryonic left-right machinery. Defects in this embryonic program controlling vertebral symmetry might lead to scoliosis in humans. Finally, the subsequent regional differentiation of the precursors of the vertebrae is controlled by Hox genes, whose collinear expression controls both gastrulation of somite precursors and their subsequent patterning into region-specific types of structures. Therefore somite development provides an outstanding paradigm to study patterning and differentiation in vertebrate embryos.

Attention to gaze and emotion in schizophrenia.

PubMed

Schwartz, Barbara L; Vaidya, Chandan J; Howard, James H; Deutsch, Stephen I

2010-11-01

Individuals with schizophrenia have difficulty interpreting social and emotional cues such as facial expression, gaze direction, body position, and voice intonation. Nonverbal cues are powerful social signals but are often processed implicitly, outside the focus of attention. The aim of this research was to assess implicit processing of social cues in individuals with schizophrenia. Patients with schizophrenia or schizoaffective disorder and matched controls performed a primary task of word classification with social cues in the background. Participants were asked to classify target words (LEFT/RIGHT) by pressing a key that corresponded to the word, in the context of facial expressions with eye gaze averted to the left or right. Although facial expression and gaze direction were irrelevant to the task, these facial cues influenced word classification performance. Participants were slower to classify target words (e.g., LEFT) that were incongruent to gaze direction (e.g., eyes averted to the right) compared to target words (e.g., LEFT) that were congruent to gaze direction (e.g., eyes averted to the left), but this only occurred for expressions of fear. This pattern did not differ for patients and controls. The results showed that threat-related signals capture the attention of individuals with schizophrenia. These data suggest that implicit processing of eye gaze and fearful expressions is intact in schizophrenia. (c) 2010 APA, all rights reserved

[Role of p38MAPK/eNOS signaling pathway in the inhibition of AGEs-induced apoptosis of human umbilical vein endothelial cells by glucagon-like peptide-1].

PubMed

Zeng, Hailong; Huang, Zhiqiu; Zhang, Yineng; Sun, Huilin

2016-01-01

To investigate the role of p38MAPK signaling pathway in the mechanism by which glucagon-like peptide-1 (GLP-1) inhibits endothelial cell damage induced by AGEs. Human umbilical vein endothelial cells were divided into control group, AGEs group, GLP-1 group, AGEs+GLP-1 group, AGEs+inhibitor group, and AGEs+GLP-1+inhibitor group. The expressions of p-p38MAPK/p38MAPK and p-eNOS/eNOS protein were examined by Western blotting, and the cell apoptosis rates were tested by flow cytometry. Compared with the control group, AGEs significantly enhanced the expression of p-p38 MAPK protein (P=0.001) while GLP-1 significantly inhibited its expression (P<0.001). AGEs significantly inhibited the expression of p-eNOS protein (P=0.007), which was enhanced by GLP-1 and p38 MAPK inhibitor (SB203580) (P=0.004). Both SB203580 and GLP-1 treatment decreased the apoptosis rate of AGEs-treated cells (P<0.001). GLP-1 can protect human umbilical vein endothelial cells against AGEs-induced apoptosis partially by inhibiting the phosphorylation of p38MAPK protein and promoting the expression of p-eNOS protein.

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

Peres, Elodie A.; Valable, Samuel; Guillamo, Jean-Sebastien

Hypoxia has been shown to be one of the major events involved in EPO expression. Accordingly, EPO might be expressed by cerebral neoplastic cells, especially in glioblastoma, known to be highly hypoxic tumours. The expression of EPOR has been described in glioma cells. However, data from the literature remain descriptive and controversial. On the basis of an endogenous source of EPO in the brain, we have focused on a potential role of EPOR in brain tumour growth. In the present study, with complementary approaches to target EPO/EPOR signalling, we demonstrate the presence of a functional EPO/EPOR system on glioma cellsmore » leading to the activation of the ERK pathway. This EPO/EPOR system is involved in glioma cell proliferation in vitro. In vivo, we show that the down-regulation of EPOR expression on glioma cells reduces tumour growth and enhances animal survival. Our results support the hypothesis that EPOR signalling in tumour cells is involved in the control of glioma growth.« less

PKCδ inhibition normalizes the wound-healing capacity of diabetic human fibroblasts.

PubMed

Khamaisi, Mogher; Katagiri, Sayaka; Keenan, Hillary; Park, Kyoungmin; Maeda, Yasutaka; Li, Qian; Qi, Weier; Thomou, Thomas; Eschuk, Danielle; Tellechea, Ana; Veves, Aris; Huang, Chenyu; Orgill, Dennis Paul; Wagers, Amy; King, George L

2016-03-01

Abnormal fibroblast function underlies poor wound healing in patients with diabetes; however, the mechanisms that impair wound healing are poorly defined. Here, we evaluated fibroblasts from individuals who had type 1 diabetes (T1D) for 50 years or more (Medalists, n = 26) and from age-matched controls (n = 7). Compared with those from controls, Medalist fibroblasts demonstrated a reduced migration response to insulin, lower VEGF expression, and less phosphorylated AKT (p-AKT), but not p-ERK, activation. Medalist fibroblasts were also functionally less effective at wound closure in nude mice. Activation of the δ isoform of protein kinase C (PKCδ) was increased in postmortem fibroblasts from Medalists, fibroblasts from living T1D subjects, biopsies of active wounds of living T1D subjects, and granulation tissues from mice with streptozotocin-induced diabetes. Diabetes-induced PKCD mRNA expression was related to a 2-fold increase in the mRNA half-life. Pharmacologic inhibition and siRNA-mediated knockdown of PKCδ or expression of a dominant-negative isoform restored insulin signaling of p-AKT and VEGF expression in vitro and improved wound healing in vivo. Additionally, increasing PKCδ expression in control fibroblasts produced the same abnormalities as those seen in Medalist fibroblasts. Our results indicate that persistent PKCδ elevation in fibroblasts from diabetic patients inhibits insulin signaling and function to impair wound healing and suggest PKCδ inhibition as a potential therapy to improve wound healing in diabetic patients.

Increased expression of endosomal members of toll-like receptor family abrogates wound healing in patients with type 2 diabetes mellitus.

PubMed

Singh, Kanhaiya; Agrawal, Neeraj K; Gupta, Sanjeev K; Mohan, Gyanendra; Chaturvedi, Sunanda; Singh, Kiran

2016-10-01

The inflammatory phase of wound healing cascade is an important determinant of the fate of the wound. Acute inflammation is necessary to initiate proper wound healing, while chronic inflammation abrogates wound healing. Different endosomal members of toll-like receptor (TLR) family initiate inflammatory signalling via a range of different inflammatory mediators such as interferons, internal tissue damaged-associated molecular patterns (DAMPs) and hyperactive effector T cells. Sustained signalling of TLR9 and TLR7 contributes to chronic inflammation by activating the plasmacytoid dendritic cells. Diabetic wounds are also characterised by sustained inflammatory phase. The objective of this study was to analyse the differential expression of endosomal TLRs in human diabetic wounds compared with control wounds. We analysed the differential expression of TLR7 and TLR9 both at transcriptional and translational levels in wounds of 84 patients with type 2 diabetes mellitus (T2DM) and 6 control subjects without diabetes using quantitative real-time polymerase chain reaction (RT-PCR), western blot and immunohistochemistry. TLR7 and TLR9 were significantly up-regulated in wounds of the patients with T2DM compared with the controls and were dependent on the infection status of the diabetic wounds, and wounds with microbial infection exhibited lower expression levels of endosomal TLRs. Altered endosomal TLR expression in T2DM subjects might be associated with wound healing impairment. © 2015 Medicalhelplines.com Inc and John Wiley & Sons Ltd.