scholarly journals Paraspeckles are subpopulation-specific nuclear bodies that are not essential in mice

2011 ◽  
Vol 193 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Shinichi Nakagawa ◽  
Takao Naganuma ◽  
Go Shioi ◽  
Tetsuro Hirose
Keyword(s):  
Adult Mouse ◽  
Expression Patterns ◽  
Physiological Role ◽  
Growth Conditions ◽  
Nuclear Bodies ◽  
Cellular Functions ◽  
Mouse Tissues

Nuclei of higher organisms are well structured and have multiple, distinct nuclear compartments or nuclear bodies. Paraspeckles are recently identified mammal-specific nuclear bodies ubiquitously found in most cells cultured in vitro. To investigate the physiological role of paraspeckles, we examined the in vivo expression patterns of two long noncoding RNAs, NEAT1_1 and NEAT1_2, which are essential for the architectural integrity of nuclear bodies. Unexpectedly, these genes were only strongly expressed in a particular subpopulation of cells in adult mouse tissues, and prominent paraspeckle formation was observed only in the cells highly expressing NEAT1_2. To further investigate the cellular functions of paraspeckles, we created an animal model lacking NEAT1 by gene targeting. These knockout mice were viable and fertile under laboratory growth conditions, showing no apparent phenotypes except for the disappearance of paraspeckles. We propose that paraspeckles are nonessential, subpopulation-specific nuclear bodies formed secondary to particular environmental triggers.

scholarly journals Cables2 Is a Novel Smad2-Regulatory Factor Essential for Early Embryonic Development in Mice

2019 ◽  
Author(s):  
Tra Thi Huong Dinh ◽  
Hiroyoshi Iseki ◽  
Seiya Mizuno ◽  
Saori Iijima-Mizuno ◽  
Yoko Tanimoto ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Expression Patterns ◽  
Physiological Role ◽  
Primitive Streak ◽  
Early Embryonic Development ◽  
Visceral Endoderm ◽  
Tetraploid Complementation ◽  
Mouse Tissues

ABSTRACTCDK5 and Abl enzyme substrate 2 (Cables2), a member of the Cables family that has a C-terminal cyclin box-like domain, is widely expressed in adult mouse tissues. However, the physiological role of Cables2 in vivo is unknown. We show here that Cables2-deficiency causes post-gastrulation embryonic lethality in mice. The mutant embryos progress to gastrulation, but then arrest, and fail to grow. Analysis of gene expression patterns reveals that formation of the anterior visceral endoderm and the primitive streak is impaired in Cables2-deficient embryos. Tetraploid complementation analyses support the critical requirement of Cables2 in both the epiblast and visceral endoderm for progression of embryogenesis. In addition, we show that Cables2 physically interacts with a key mediator of the canonical Nodal pathway, Smad2, and augments its transcriptional activity. These findings provide novel insights into the essential role of Cables2 in the early embryonic development in mice.

scholarly journals Purinergic Modulation of Interleukin-1β Release from Microglial Cells Stimulated with Bacterial Endotoxin

1997 ◽  
Vol 185 (3) ◽  
pp. 579-582 ◽  
Author(s):  
Davide Ferrari ◽  
Paola Chiozzi ◽  
Simonetta Falzoni ◽  
Stefania Hanau ◽  
Francesco Di  Virgilio
Keyword(s):  
Plasma Membrane ◽  
P2x7 Receptor ◽  
Purinergic Receptor ◽  
Present Report ◽  
Physiological Role ◽  
Bacterial Endotoxin ◽  
Microglial Cells

Microglial cells express a peculiar plasma membrane receptor for extracellular ATP, named P2Z/P2X7 purinergic receptor, that triggers massive transmembrane ion fluxes and a reversible permeabilization of the plasma membrane to hydrophylic molecules of up to 900 dalton molecule weight and eventual cell death (Di Virgilio, F. 1995. Immunol. Today. 16:524–528). The physiological role of this newly cloned (Surprenant, A., F. Rassendren, E. Kawashima, R.A. North and G. Buell. 1996. Science (Wash. DC). 272:735–737) cytolytic receptor is unknown. In vitro and in vivo activation of the macrophage and microglial cell P2Z/P2X7 receptor by exogenous ATP causes a large and rapid release of mature IL-1β. In the present report we investigated the role of microglial P2Z/P2X7 receptor in IL-1β release triggered by LPS. Our data suggest that LPS-dependent IL-1β release involves activation of this purinergic receptor as it is inhibited by the selective P2Z/P2X7 blocker oxidized ATP and modulated by ATP-hydrolyzing enzymes such as apyrase or hexokinase. Furthermore, microglial cells release ATP when stimulated with LPS. LPS-dependent release of ATP is also observed in monocyte-derived human macrophages. It is suggested that bacterial endotoxin activates an autocrine/paracrine loop that drives ATP-dependent IL-1β secretion.

scholarly journals Increased Fitness of Pseudomonas fluorescens Pf0-1 Leucine Auxotrophs in Soil

2008 ◽  
Vol 74 (12) ◽  
pp. 3644-3651 ◽  
Author(s):  
Wook Kim ◽  
Stuart B. Levy
Keyword(s):  
Pseudomonas Fluorescens ◽  
Bacterial Genome ◽  
Physiological Role ◽  
Underlying Mechanism ◽  
Growth Conditions ◽  
Soil Environment ◽  
Fitness Advantage ◽  
Gene Structures

ABSTRACT The annotation process of a newly sequenced bacterial genome is largely based on algorithms derived from databases of previously defined RNA and protein-encoding gene structures. This process generally excludes the possibility that the two strands of a given stretch of DNA can each harbor a gene in an overlapping manner. While the presence of such structures in eukaryotic genomes is considered to be relatively common, their counterparts in prokaryotic genomes are just beginning to be recognized. Application of an in vivo expression technology has previously identified 22 discrete genetic loci in Pseudomonas fluorescens Pf0-1 that were specifically activated in the soil environment, of which 10 were present in an antisense orientation relative to previously annotated genes. This observation led to the hypothesis that the physiological role of overlapping genetic structures may be relevant to growth conditions outside artificial laboratory media. Here, we examined the role of one of the overlapping gene pairs, iiv19 and leuA2, in soil. Although iiv19 was previously demonstrated to be preferentially activated in the soil environment, its absence did not alter the ability of P. fluorescens to colonize or survive in soil. Surprisingly, the absence of the leuA2 gene conferred a fitness advantage in the soil environment when leucine was supplied exogenously. This effect was determined to be independent of the iiv19 gene, and further analyses revealed that amino acid antagonism was the underlying mechanism behind the observed fitness advantage of the bacterium in soil. Our findings provide a potential mechanism for the frequent occurrence of auxotrophic mutants of Pseudomonas spp. in the lungs of cystic fibrosis patients.

Immunomodulation by 17β-estradiol in bivalve hemocytes

2006 ◽  
Vol 291 (3) ◽  
pp. R664-R673 ◽  
Author(s):  
Laura Canesi ◽  
Caterina Ciacci ◽  
Lucia Cecilia Lorusso ◽  
Michele Betti ◽  
Tiziana Guarnieri ◽  
...  
Keyword(s):  
Kinase Inhibitors ◽  
Hydrolytic Enzymes ◽  
Physiological Role ◽  
Estrogen Receptor Α ◽  
Nitrite Accumulation ◽  
No Production ◽  
17Β Estradiol

In mammals, estrogens have dose- and cell-type-specific effects on immune cells and may act as pro- and anti-inflammatory stimuli, depending on the setting. In the bivalve mollusc Mytilus, the natural estrogen 17β-estradiol (E2) has been shown to affect neuroimmune functions. We have investigated the immunomodulatory role of E2 in Mytilus hemocytes, the cells responsible for the innate immune response. E2 at 5–25 nM rapidly stimulated phagocytosis and oxyradical production in vitro; higher concentrations of E2 inhibited phagocytosis. E2-induced oxidative burst was prevented by the nitric oxide (NO) synthase inhibitor NG-monomethyl-l-arginine and superoxide dismutase, indicating involvement of NO and O2−; NO production was confirmed by nitrite accumulation. The effects of E2 were prevented by the antiestrogen tamoxifen and by specific kinase inhibitors, indicating a receptor-mediated mechanism and involvement of p38 MAPK and PKC. E2 induced rapid and transient increases in the phosphorylation state of PKC, as well as of a aCREB-like (cAMP responsive element binding protein) transcription factor, as indicated by Western blot analysis with specific anti-phospho-antibodies. Localization of estrogen receptor-α- and -β-like proteins in hemocytes was investigated by immunofluorescence confocal microscopy. The effects of E2 on immune function were also investigated in vivo at 6 and 24 h in hemocytes of E2-injected mussels. E2 significantly affected hemocyte lysosomal membrane stability, phagocytosis, and extracellular release of hydrolytic enzymes: lower concentrations of E2 resulted in immunostimulation, and higher concentrations were inhibitory. Our data indicate that the physiological role of E2 in immunomodulation is conserved from invertebrates to mammals.

A role for the EphA family in the topographic targeting of vomeronasal axons

Development ◽  
2001 ◽  
Vol 128 (6) ◽  
pp. 895-906
Author(s):  
B. Knoll ◽  
K. Zarbalis ◽  
W. Wurst ◽  
U. Drescher
Keyword(s):  
Tyrosine Kinases ◽  
Expression Patterns ◽  
Eph Receptors ◽  
Accessory Olfactory Bulb ◽  
In Vivo Experiments ◽  
Receptor Concentration ◽  
High Ligand

We have investigated the role of the Eph family of receptor tyrosine kinases and their ligands in the establishment of the vomeronasal projection in the mouse. Our data show intriguing differential expression patterns of ephrin-A5 on vomeronasal axons and of EphA6 in the accessory olfactory bulb (AOB), such that axons with high ligand concentration project onto regions of the AOB with high receptor concentration and vice versa. These data suggest a mechanism for development of this projection that is the opposite of the repellent interaction between Eph receptors and ligands observed in other systems. In support of this idea, when given the choice of whether to grow on lanes containing EphA-F(c)/laminin or F(c)/laminin protein (in the stripe assay), vomeronasal axons prefer to grow on EphA-F(c)/laminin. Analysis of ephrin-A5 mutant mice revealed a disturbance of the topographic targeting of vomeronasal axons to the AOB. In summary, these data, which are derived from in vitro and in vivo experiments, indicate an important role of the EphA family in setting up the vomeronasal projection.

scholarly journals Escherichia coli NsrR Regulates a Pathway for the Oxidation of 3-Nitrotyramine to 4-Hydroxy-3-Nitrophenylacetate

2008 ◽  
Vol 190 (18) ◽  
pp. 6170-6177 ◽  
Author(s):  
Linda D. Rankin ◽  
Diane M. Bodenmiller ◽  
Jonathan D. Partridge ◽  
Shirley F. Nishino ◽  
Jim C. Spain ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Physiological Role ◽  
Growth Conditions ◽  
Growth Defect ◽  
E Coli ◽  
Mutant Phenotypes ◽  
Culture Supernatants ◽  
Chip Chip

ABSTRACT Chromatin immunoprecipitation and microarray (ChIP-chip) analysis showed that the nitric oxide (NO)-sensitive repressor NsrR from Escherichia coli binds in vivo to the promoters of the tynA and feaB genes. These genes encode the first two enzymes of a pathway that is required for the catabolism of phenylethylamine (PEA) and its hydroxylated derivatives tyramine and dopamine. Deletion of nsrR caused small increases in the activities of the tynA and feaB promoters in cultures grown on PEA. Overexpression of nsrR severely retarded growth on PEA and caused a marked repression of the tynA and feaB promoters. Both the growth defect and the promoter repression were reversed in the presence of a source of NO. These results are consistent with NsrR mediating repression of the tynA and feaB genes by binding (in an NO-sensitive fashion) to the sites identified by ChIP-chip. E. coli was shown to use 3-nitrotyramine as a nitrogen source for growth, conditions which partially induce the tynA and feaB promoters. Mutation of tynA (but not feaB) prevented growth on 3-nitrotyramine. Growth yields, mutant phenotypes, and analyses of culture supernatants suggested that 3-nitrotyramine is oxidized to 4-hydroxy-3-nitrophenylacetate, with growth occurring at the expense of the amino group of 3-nitrotyramine. Accordingly, enzyme assays showed that 3-nitrotyramine and its oxidation product (4-hydroxy-3-nitrophenylacetaldehyde) could be oxidized by the enzymes encoded by tynA and feaB, respectively. The results suggest that an additional physiological role of the PEA catabolic pathway is to metabolize nitroaromatic compounds that may accumulate in cells exposed to NO.

scholarly journals Two Quenchers Formed During Photodamage of Phostosystem II and The Role of One Quencher in Preemptive Photoprotection

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alonso Zavafer ◽  
Ievgeniia Iermak ◽  
Mun Hon Cheah ◽  
Wah Soon Chow
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosystem Ii ◽  
Time Course ◽  
Physiological Role ◽  
Reaction Centre ◽  
Time Resolved ◽  
Fluorescence Quencher

AbstractThe quenching of chlorophyll fluorescence caused by photodamage of Photosystem II (qI) is a well recognized phenomenon, where the nature and physiological role of which are still debatable. Paradoxically, photodamage to the reaction centre of Photosystem II is supposed to be alleviated by excitation quenching mechanisms which manifest as fluorescence quenchers. Here we investigated the time course of PSII photodamage in vivo and in vitro and that of picosecond time-resolved chlorophyll fluorescence (quencher formation). Two long-lived fluorescence quenching processes during photodamage were observed and were formed at different speeds. The slow-developing quenching process exhibited a time course similar to that of the accumulation of photodamaged PSII, while the fast-developing process took place faster than the light-induced PSII damage. We attribute the slow process to the accumulation of photodamaged PSII and the fast process to an independent quenching mechanism that precedes PSII photodamage and that alleviates the inactivation of the PSII reaction centre.

scholarly journals Tissue-specific characterization of mitochondrial branched-chain keto acid oxidation using a multiplexed assay platform

2019 ◽  
Vol 476 (10) ◽  
pp. 1521-1537 ◽  
Author(s):  
Emma J. Goldberg ◽  
Katherine A. Buddo ◽  
Kelsey L. McLaughlin ◽  
Regina F. Fernandez ◽  
Andrea S. Pereyra ◽  
...  
Keyword(s):  
Acid Oxidation ◽  
Valuable Insight ◽  
Keto Acid ◽  
Isolated Mitochondria ◽  
Mouse Tissues ◽  
Branched Chain

Abstract Alterations to branched-chain keto acid (BCKA) oxidation have been implicated in a wide variety of human diseases, ranging from diabetes to cancer. Although global shifts in BCKA metabolism—evident by gene transcription, metabolite profiling, and in vivo flux analyses have been documented across various pathological conditions, the underlying biochemical mechanism(s) within the mitochondrion remain largely unknown. In vitro experiments using isolated mitochondria represent a powerful biochemical tool for elucidating the role of the mitochondrion in driving disease. Such analyses have routinely been utilized across disciplines to shed valuable insight into mitochondrial-linked pathologies. That said, few studies have attempted to model in vitro BCKA oxidation in isolated organelles. The impetus for the present study stemmed from the knowledge that complete oxidation of each of the three BCKAs involves a reaction dependent upon bicarbonate and ATP, both of which are not typically included in respiration experiments. Based on this, it was hypothesized that the inclusion of exogenous bicarbonate and stimulation of respiration using physiological shifts in ATP-free energy, rather than excess ADP, would allow for maximal BCKA-supported respiratory flux in isolated mitochondria. This hypothesis was confirmed in mitochondria from several mouse tissues, including heart, liver and skeletal muscle. What follows is a thorough characterization and validation of a novel biochemical tool for investigating BCKA metabolism in isolated mitochondria.

scholarly journals Vitamin D and prostate cancer

2013 ◽  
Vol 66 (5-6) ◽  
pp. 259-262
Author(s):  
Goran Marusic ◽  
Dimitrije Jeremic ◽  
Sasa Vojinov ◽  
Natasa Filipovic ◽  
Milan Popov
Keyword(s):  
Prostate Cancer ◽  
Vitamin D ◽  
Physiological Role ◽  
In Vivo Studies ◽  
Vitamin D Metabolism ◽  
Genetic Changes ◽  
Metabolic Role

In addition to the metabolic role of vitamin D, which is well known and clearly defined, there have been many hypotheses regarding its anti-proliferative and pro-apoptotic role. Epidemiology and Significance of Prostate Cancer. Prostate cancer is the second most common malignancy in men. Long period of cancerogenesis, available tumor markers and high incidence make this cancer ideal for preventive measures. Physiological Role of Vitamin D and its Effect on Prostate Cancer Cells. In vitro and in vivo studies have shown the anti-proliferative and pro-apoptopic role of vitamin D. Disorders of vitamin D metabolism are noted in vitamin D gene level, vitamin D receptor, vitamin D responsive elements and androgen receptors. We present the most important effect of those changes on vitamin D metabolism. Conclusion. Available studies on vitamin D level in serum, prostate tissue, observed activity of vitamin D enzymes and genetic changes give us only a slight insight into the basic mechanisms of vitamin D action in the development of prostate cancer; therefore, further investigations are needed.

Chronic Lymphocytic Leukemia-Associated Macrophages: Not Just Nurse Cells

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 46-46
Author(s):  
Loic Ysebaert ◽  
Mary Poupot ◽  
Yovan Sanchez-Ruiz ◽  
Camille Laurent ◽  
Guy Laurent ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Conditioned Medium ◽  
Apoptotic Cell ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Lymphocytic Leukemia ◽  
Functional Interpretation

Abstract Abstract 46 Introduction: CLL cells interact with many accessory cells in an environment mimicking that of normal mature B cells. Role of antigen, cytokines, adhesion pathways are critical for many aspects in the disease course (proliferation/survival, migration or homing, drug resistance, and presumably relapse). Nurse-like cells (NLC) belong to a monocytic-derived, bystander population among CLL lymph node and spleen stromal cells. Aim: To investigate the nature, functions, and location of NLC within CLL microenvironment. Methods: Gene expression profiles (GEP) from in vitro expanded NLC from patients (n=10) were produced and compared to those from normal CD14+ monocytes, M1-polarized macrophages, M2-polarized macrophages and tumor-associated macrophages (produced in the lab or downloaded from GEO datasets). Principal Component Analysis was used to categorize these five populations of cells and in-house-built GSEA software was used for functional interpretation of their relevant gene lists. Protein expression patterns were validated with multi-analyte ELISArray kits, proteome profiler arrays, flow cytometry (FC) or immunohistochemistry (IHC). Results: New insights into the physiopathological role of NLC in CLL are suggested from five lines of evidence: 1/a Òmonocytic gene signatureÓ (i.e. a set of 549 genes) is shared by the NLC and the monocyte subtypes. The genes over-represented in NLC vs normal monocytes pinpointed positive modulation of apoptotic cell clearance (scavenger, mannose and complement receptors, LXRalpha), lipid metabolism (Apolipoprotein E, PPAR signaling), extracellular matrix-receptor interactions (integrins, SPARC, Matrix MetalloProteinases) and actin cytoskeleton remodeling. 2/unsupervised clustering show that NLC represent an M2-skewed, TAM-like cell population. They down-regulate mRNA and proteins for classic M1 inflammatory markers (e.g. IL-1, IL-6, IL-12, COX2) while increase secretion of TGFbeta, IL-10, CCL17 and CCL22 soluble factors. 3/these and previously published observations suggest that B-CLL-to-NLC interactions may orchestrate immunosuppression in this disease. PBMCs from Òwatch and waitÓ CLL patients (all stage A/Rai 0, mutated IgVH, low risk cytogenetics profile) or healthy donors were stimulated with anti-CD3/CD28 beads + IL-2, either in standard RPMI+10% FCS or in conditioned medium (CM, after 14d CLL-NLC co-culture in vitro) and their proliferation/phenotype were compared after 2 weeks. Significant expansion of T cells with Treg (CD4+CD25+FoxP3+) phenotype was observed only from CLL PBMCs grown in conditioned medium (mean % Treg: 2.85 vs 3.05 in CM for normal PBMCs, and 1.54 vs 15.9 in CM for CLL PBMCs, P< 0.05). 4/although NLC make immune synapses with live B-CLL, they do not phagocytose them. Over-expression of CD47 (ÒdonÕt eat meÓ signal) by B-CLL cells (mfi= 3490 vs 2581 on normal cells, P< 0.05, n=18) may provide them with a protective signal against NLC. 5/from our GEP, flow cytometric and IHC analyses, we propose CD163 (classic M2 marker) as a reliable tool to identify NLC in vivo. Although in vitro, CLL cells can pervert healthy donor monocytes into NLC, only CLL-derived NLC are truly CD14+ CD163+. In vivo, CD163 staining reveals putative NLC in CLL lymph nodes(LN)/spleen sections but not in bone marrow. In LN from all patients, NLC reside in the subcapsular areas and line vessel structures, suggesting a role in CLL cells trafficking. Most interestingly, NLC infiltrate pseudofollicles structures only in a subset of cases. We will present updated IHC and clinical presentation correlation studies. Conclusions: Our results suggest that the role of NLC in CLL might be broader than initially thought. Beside of nursing and conferring drug resistance, NLC may also be crucial in the setting of immunosuppression, of CLL cells recruitment, and should thus be considered as therapeutic targets. Disclosures: Off Label Use: GA101 is not currently approved for CLL treatment.

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