Conjunctival Goblet Cell Function: Effect of Contact Lens Wear and Cytokines

PubMed Central

García-Posadas, Laura; Contreras-Ruiz, Laura; Soriano-Romaní, Laura; Dartt, Darlene A.; Diebold, Yolanda

2015-01-01

This review focuses on conjunctival goblet cells and their essential function in the maintenance of eye health. The main function of goblet cells is to produce and secrete mucins that lubricate the ocular surface. An excess or a defect in those mucins leads to several alterations that makes goblet cells central players in maintaining the proper mucin balance and ensuring the correct function of ocular surface tissues. A typical pathology that occurs with mucous deficiency is dry eye disease, whereas the classical example of mucous hyperproduction is allergic conjunctivitis. In this review we analyze how goblet cell number and function can be altered in these diseases and in contact lens wearers. We found that most published studies focused exclusively on goblet cell number. However, recent advances have demonstrated that, along with mucin secretion, goblet cells are also able to secrete cytokines and respond to them. We describe the effect of different cytokines on goblet cell proliferation and secretion. We conclude that it is important to further explore the effect of contact lens wear and cytokines on conjunctival goblet cell function. PMID:26067396

Altered T-Cell Balance in Lymphoid Organs of a Mouse Model of Colorectal Cancer

PubMed Central

Tanner, Scott M.; Daft, Joseph G.; Hill, Stephanie A.; Martin, Colin A.; Lorenz, Robin G.

2016-01-01

The adenomatous polyposis coli (APC) gene is a known tumor suppressor gene, and mice with mutations in Apc (ApcMin/+) spontaneously form multiple intestinal neoplasms. In this model of human colorectal cancer (CRC), it has been reported that CD4+ T-cell-derived interleukin 17 (IL-17) promotes intestinal tumor development, but it is not known if the Apc mutation actually directly alters T-cell function and subsequently tumor immunosurveillance. To investigate the ApcMin/+ mutation on T-cell function, flow cytometric, histochemical, and immunofluorescent studies on both wild-type (Apc+/+) and ApcMin/+ mice were performed. We identified decreased levels of interferon gamma (IFN-γ+)IL-17+ double-positive CD4+ cells in the mesenteric lymph nodes and Peyer’s patches of ApcMin/+ mice. In addition, altered levels of CD8+ cells, and changes in CD8+ production of IFN-γ and granzyme B were observed. These T-cell alterations did modify tumor immunosurveillance, as the adoptive transfer of splenocytes from ApcMin/+ animals into a chemically induced CRC model resulted in the inability to prevent epithelial dysplasia. These results suggest an altered T-cell balance in ApcMin/+ mice may disrupt intestinal homeostasis, consequently limiting intestinal tumor immunosurveillance. PMID:27798287

Altered T-Cell Balance in Lymphoid Organs of a Mouse Model of Colorectal Cancer.

PubMed

Tanner, Scott M; Daft, Joseph G; Hill, Stephanie A; Martin, Colin A; Lorenz, Robin G

2016-12-01

The adenomatous polyposis coli (APC) gene is a known tumor suppressor gene, and mice with mutations in Apc (Apc Min/+ ) spontaneously form multiple intestinal neoplasms. In this model of human colorectal cancer (CRC), it has been reported that CD4 + T-cell-derived interleukin 17 (IL-17) promotes intestinal tumor development, but it is not known if the Apc mutation actually directly alters T-cell function and subsequently tumor immunosurveillance. To investigate the Apc Min/+ mutation on T-cell function, flow cytometric, histochemical, and immunofluorescent studies on both wild-type (Apc +/+ ) and Apc Min/+ mice were performed. We identified decreased levels of interferon gamma (IFN-γ + )IL-17 + double-positive CD4 + cells in the mesenteric lymph nodes and Peyer's patches of Apc Min/+ mice. In addition, altered levels of CD8 + cells, and changes in CD8 + production of IFN-γ and granzyme B were observed. These T-cell alterations did modify tumor immunosurveillance, as the adoptive transfer of splenocytes from Apc Min/+ animals into a chemically induced CRC model resulted in the inability to prevent epithelial dysplasia. These results suggest an altered T-cell balance in Apc Min/+ mice may disrupt intestinal homeostasis, consequently limiting intestinal tumor immunosurveillance. © 2016 The Histochemical Society.

ORIENTATION REQUIREMENT TO DETECT MAGNETIC FIELD-INDUCTED ALTERATION OF GAP JUNCTION COMMUNICATION IN EPITHELIAL CELLS

EPA Science Inventory

ORIENTATION REQUIREMENT TO DETECT MAGNETIC FIELD-INDUCED ALTERATION OF GAP JUNCTION COMMUNICATION IN EPITHELIAL CELLS.
OBJECTIVE: We have shown that functional gap junction communication as measured by Lucifer yellow dye transfer (DT) in Clone-9 rat liver epithelial cells, c...

Alteration of Multiple Cell Membrane Functions in L-6 Myoblasts by T-2 Toxin: An Important Mechanism of Action.

DTIC Science & Technology

1986-06-04

menbrane functions. All are in a range that would in turn be expected to alter other cell functions. Intracellular LEH was reduced 10 min after T-2... Plasma amino F-id changes in guinea pigs injected with T-2 rnycotoxin. Fed. Proc. 42, 625. 20 1111" ll p J IIIý f%𔃻 11 IC IA 114 WEAVER, G.A., MW1•Z, H.J

Antiproliferative mechanisms of the flavonoids 2,2'-dihydroxychalcone and fisetin in human prostate cancer cells.

PubMed

Haddad, Ahmed Q; Fleshner, Neil; Nelson, Colleen; Saour, Basil; Musquera, Mireia; Venkateswaran, Vasundara; Klotz, Laurence

2010-01-01

We have previously demonstrated the antiproliferative effect of two flavonoids-2,2'-dihydroxychalcone (DHC), a novel synthetic flavonoid, and fisetin, a naturally occurring flavonol-in prostate cancer cells. In this study, we further examine the mechanisms of these compounds on survival and proliferation pathways. DHC and fisetin (1-50 microM) caused a dose-dependent reduction in viability, a concomitant increase in apoptosis in PC3 cells at 72 h, and a decrease in clonogenic survival at 24 h treatment. DHC was considerably more potent than fisetin in these cytotoxicity assays. The mechanism of accelerated cellular senescence was not activated by either compound in PC3 or lymph node carcinoma of the prostate (LNCaP) cells. Gene expression alterations in PC3 and LNCaP cells treated with 15 muM DHC and 25 microM fisetin for 6 to 24 h were determined by oligonucleotide array. Amongst the most highly represented functional categories of genes altered by both compounds was the cell cycle category. In total, 100 cell cycle genes were altered by DHC and fisetin including 27 genes with key functions in G2/M phase that were downregulated by both compounds. Other functional categories altered included chromosome organization, apoptosis, and stress response. These results demonstrate the multiple mechanisms of antitumor activity of DHC and fisetin in prostate cancer cells in vitro.

Cellular and epigenetic drivers of stem cell ageing.

PubMed

Ermolaeva, Maria; Neri, Francesco; Ori, Alessandro; Rudolph, K Lenhard

2018-06-01

Adult tissue stem cells have a pivotal role in tissue maintenance and regeneration throughout the lifespan of multicellular organisms. Loss of tissue homeostasis during post-reproductive lifespan is caused, at least in part, by a decline in stem cell function and is associated with an increased incidence of diseases. Hallmarks of ageing include the accumulation of molecular damage, failure of quality control systems, metabolic changes and alterations in epigenome stability. In this Review, we discuss recent evidence in support of a novel concept whereby cell-intrinsic damage that accumulates during ageing and cell-extrinsic changes in ageing stem cell niches and the blood result in modifications of the stem cell epigenome. These cumulative epigenetic alterations in stem cells might be the cause of the deregulation of developmental pathways seen during ageing. In turn, they could confer a selective advantage to mutant and epigenetically drifted stem cells with altered self-renewal and functions, which contribute to the development of ageing-associated organ dysfunction and disease.

Functional and quantitative alterations in T lymphocyte subpopulations in acute toxoplasmosis.

PubMed

Luft, B J; Kansas, G; Engleman, E G; Remington, J S

1984-11-01

The cellular immune response to Toxoplasma gondii has been studied in 23 patients with acute toxoplasma infection. Abnormalities of T cell subpopulations included a marked and significant elevation in suppressor (Leu 2) T cells in patients with prolonged symptoms due to acute infection and either a decrease in the number of T helper cells or an increase in the number of suppressor cells--or both--in patients with asymptomatic lymphadenopathy. There was no significant difference in lymphocyte proliferation to phytohemagglutinin or pokeweed mitogen among the various groups tested. The peak lymphocyte response to toxoplasma antigen, however, was significantly depressed in patients with acute infection compared with that in chronically infected control patients. The kinetics of the depression were consistent with the induction of a non-Leu 2 suppressor cell. These results demonstrate marked quantitative alterations in T lymphocyte subpopulations and functional alterations of T cells to toxoplasma antigen during infection with T. gondii.

Altered Cell Mechanics from the Inside: Dispersed Single Wall Carbon Nanotubes Integrate with and Restructure Actin

PubMed Central

Holt, Brian D.; Shams, Hengameh; Horst, Travis A.; Basu, Saurav; Rape, Andrew D.; Wang, Yu-Li; Rohde, Gustavo K.; Mofrad, Mohammad R. K.; Islam, Mohammad F.; Dahl, Kris Noel

2012-01-01

With a range of desirable mechanical and optical properties, single wall carbon nanotubes (SWCNTs) are a promising material for nanobiotechnologies. SWCNTs also have potential as biomaterials for modulation of cellular structures. Previously, we showed that highly purified, dispersed SWCNTs grossly alter F-actin inside cells. F-actin plays critical roles in the maintenance of cell structure, force transduction, transport and cytokinesis. Thus, quantification of SWCNT-actin interactions ranging from molecular, sub-cellular and cellular levels with both structure and function is critical for developing SWCNT-based biotechnologies. Further, this interaction can be exploited, using SWCNTs as a unique actin-altering material. Here, we utilized molecular dynamics simulations to explore the interactions of SWCNTs with actin filaments. Fluorescence lifetime imaging microscopy confirmed that SWCNTs were located within ~5 nm of F-actin in cells but did not interact with G-actin. SWCNTs did not alter myosin II sub-cellular localization, and SWCNT treatment in cells led to significantly shorter actin filaments. Functionally, cells with internalized SWCNTs had greatly reduced cell traction force. Combined, these results demonstrate direct, specific SWCNT alteration of F-actin structures which can be exploited for SWCNT-based biotechnologies and utilized as a new method to probe fundamental actin-related cellular processes and biophysics. PMID:24955540

[The child's brain: normal (unaltered) development and development altered by perinatal injury].

PubMed

Marín-Padilla, Miguel

2013-09-06

In this study we analyse some of the morphological and functional aspects of normal and altered development (the latter due to perinatal injury) in the child's brain. Both normal and altered development are developmental processes that progressively interconnect the different regions. The neuropathological development of subpial and periventricular haemorrhages, as well as that of white matter infarct, are analysed in detail. Any kind of brain damage causes a local lesion with possible remote repercussions. All the components (neurons, fibres, blood capillaries and neuroglias) of the affected region undergo alterations. Those that are destroyed are eliminated by the inflammatory process and those that survive are transformed. The pyramidal neurons with amputated apical dendrites are transformed and become stellate cells, the axonal terminals and those of the radial glial cells are regenerated and the region involved is reinnervated and revascularised with an altered morphology and function (altered local corticogenesis). The specific microvascular system of the grey matter protects its neurons from infarction of the white matter. Although it survives, the grey matter is left disconnected from the afferent and efferent fibres, amputated by the infarct with alterations affecting its morphology and possibly its functioning (altered local corticogenesis). Any local lesion can modify the morphological and functional development of remote regions that are functionally interconnected with it (altered remote corticogenesis). We suggest that any local brain injury can alter the morphology and functioning of the regions that are morphologically and functionally interconnected with it and thus end up affecting the child's neurological and psychological development. These changes can cross different regions of the brain (epileptic auras) and, if they eventually reach the motor region, will give rise to the motor storm that characterises epilepsy.

Virus-induced gene silencing offers a functional genomics platform for studying plant cell wall formation.

PubMed

Zhu, Xiaohong; Pattathil, Sivakumar; Mazumder, Koushik; Brehm, Amanda; Hahn, Michael G; Dinesh-Kumar, S P; Joshi, Chandrashekhar P

2010-09-01

Virus-induced gene silencing (VIGS) is a powerful genetic tool for rapid assessment of plant gene functions in the post-genomic era. Here, we successfully implemented a Tobacco Rattle Virus (TRV)-based VIGS system to study functions of genes involved in either primary or secondary cell wall formation in Nicotiana benthamiana plants. A 3-week post-VIGS time frame is sufficient to observe phenotypic alterations in the anatomical structure of stems and chemical composition of the primary and secondary cell walls. We used cell wall glycan-directed monoclonal antibodies to demonstrate that alteration of cell wall polymer synthesis during the secondary growth phase of VIGS plants has profound effects on the extractability of components from woody stem cell walls. Therefore, TRV-based VIGS together with cell wall component profiling methods provide a high-throughput gene discovery platform for studying plant cell wall formation from a bioenergy perspective.

Traits, properties, and performance: how woody plants combine hydraulic and mechanical functions in a cell, tissue, or whole plant.

PubMed

Lachenbruch, Barbara; McCulloh, Katherine A

2014-12-01

This review presents a framework for evaluating how cells, tissues, organs, and whole plants perform both hydraulic and mechanical functions. The morphological alterations that affect dual functionality are varied: individual cells can have altered morphology; tissues can have altered partitioning to functions or altered cell alignment; and organs and whole plants can differ in their allocation to different tissues, or in the geometric distribution of the tissues they have. A hierarchical model emphasizes that morphological traits influence the hydraulic or mechanical properties; the properties, combined with the plant unit's environment, then influence the performance of that plant unit. As a special case, we discuss the mechanisms by which the proxy property wood density has strong correlations to performance but without direct causality. Traits and properties influence multiple aspects of performance, and there can be mutual compensations such that similar performance occurs. This compensation emphasizes that natural selection acts on, and a plant's viability is determined by, its performance, rather than its contributing traits and properties. Continued research on the relationships among traits, and on their effects on multiple aspects of performance, will help us better predict, manage, and select plant material for success under multiple stresses in the future. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

GABA FUNCTION IS ALTERED FOLLOWING DEVELOPMENTAL HYPOTHYROIDISM: NEUROANATOMICAL AND NEUROPHYSIOLOGICAL EVIDENCE.

EPA Science Inventory

Thyroid hormone deficiency during development produces changes in the structure of neurons and glial cells and alters synaptic function in the hippocampus. GABAergic interneurons comprise the bulk of local inhibitory neuronal circuitry and a subpopulation of these interneurons ...

Csf2 null mutation alters placental gene expression and trophoblast glycogen cell and giant cell abundance in mice.

PubMed

Sferruzzi-Perri, Amanda N; Macpherson, Anne M; Roberts, Claire T; Robertson, Sarah A

2009-07-01

Genetic deficiency in granulocyte-macrophage colony-stimulating factor (CSF2, GM-CSF) results in altered placental structure in mice. To investigate the mechanism of action of CSF2 in placental morphogenesis, the placental gene expression and cell composition were examined in Csf2 null mutant and wild-type mice. Microarray and quantitative RT-PCR analyses on Embryonic Day (E) 13 placentae revealed that the Csf2 null mutation caused altered expression of 17 genes not previously known to be associated with placental development, including Mid1, Cd24a, Tnfrsf11b, and Wdfy1. Genes controlling trophoblast differentiation (Ascl2, Tcfeb, Itgav, and Socs3) were also differentially expressed. The CSF2 ligand and the CSF2 receptor alpha subunit were predominantly synthesized in the placental junctional zone. Altered placental structure in Csf2 null mice at E15 was characterized by an expanded junctional zone and by increased Cx31(+) glycogen cells and cyclin-dependent kinase inhibitor 1C (CDKN1C(+), P57(Kip2+)) giant cells, accompanied by elevated junctional zone transcription of genes controlling spongiotrophoblast and giant cell differentiation and secretory function (Ascl2, Hand1, Prl3d1, and Prl2c2). Granzyme genes implicated in tissue remodeling and potentially in trophoblast invasion (Gzmc, Gzme, and Gzmf) were downregulated in the junctional zone of Csf2 null mutant placentae. These data demonstrate aberrant placental gene expression in Csf2 null mutant mice that is associated with altered differentiation and/or functional maturation of junctional zone trophoblast lineages, glycogen cells, and giant cells. We conclude that CSF2 is a regulator of trophoblast differentiation and placental development, which potentially influences the functional capacity of the placenta to support optimal fetal growth in pregnancy.

In Vitro Expansion of Bone Marrow Derived Mesenchymal Stem Cells Alters DNA Double Strand Break Repair of Etoposide Induced DNA Damage.

PubMed

Hare, Ian; Gencheva, Marieta; Evans, Rebecca; Fortney, James; Piktel, Debbie; Vos, Jeffrey A; Howell, David; Gibson, Laura F

2016-01-01

Mesenchymal stem cells (MSCs) are of interest for use in diverse cellular therapies. Ex vivo expansion of MSCs intended for transplantation must result in generation of cells that maintain fidelity of critical functions. Previous investigations have identified genetic and phenotypic alterations of MSCs with in vitro passage, but little is known regarding how culturing influences the ability of MSCs to repair double strand DNA breaks (DSBs), the most severe of DNA lesions. To investigate the response to DSB stress with passage in vitro, primary human MSCs were exposed to etoposide (VP16) at various passages with subsequent evaluation of cellular damage responses and DNA repair. Passage number did not affect susceptibility to VP16 or the incidence and repair kinetics of DSBs. Nonhomologous end joining (NHEJ) transcripts showed little alteration with VP16 exposure or passage; however, homologous recombination (HR) transcripts were reduced following VP16 exposure with this decrease amplified as MSCs were passaged in vitro. Functional evaluations of NHEJ and HR showed that MSCs were unable to activate NHEJ repair following VP16 stress in cells after successive passage. These results indicate that ex vivo expansion of MSCs alters their ability to perform DSB repair, a necessary function for cells intended for transplantation.

Altered cell function in microgravity

NASA Technical Reports Server (NTRS)

Hughes-Fulford, Millie

1991-01-01

The paper overviews published results from investigations of changes in basic biological parameters taking place as a result of spaceflight exposure. These include changes in the rates of the DNA, mRNA, and protein biosyntheses; changes in the growth rate of an organism; and alterations in the cytoskeleton structure, differentiation, hormone accumulation, and collagen matrix secretion. These results, obtained both in complex biological organisms and on cultured cells, suggest that a basic cellular function is influenced and changed by microgravity. Many of the above mentioned changes are also found to take place in aging cells.

CTCF genetic alterations in endometrial carcinoma are pro-tumorigenic

PubMed Central

Marshall, A D; Bailey, C G; Champ, K; Vellozzi, M; O'Young, P; Metierre, C; Feng, Y; Thoeng, A; Richards, A M; Schmitz, U; Biro, M; Jayasinghe, R; Ding, L; Anderson, L; Mardis, E R; Rasko, J E J

2017-01-01

CTCF is a haploinsufficient tumour suppressor gene with diverse normal functions in genome structure and gene regulation. However the mechanism by which CTCF haploinsufficiency contributes to cancer development is not well understood. CTCF is frequently mutated in endometrial cancer. Here we show that most CTCF mutations effectively result in CTCF haploinsufficiency through nonsense-mediated decay of mutant transcripts, or loss-of-function missense mutation. Conversely, we identified a recurrent CTCF mutation K365T, which alters a DNA binding residue, and acts as a gain-of-function mutation enhancing cell survival. CTCF genetic deletion occurs predominantly in poor prognosis serous subtype tumours, and this genetic deletion is associated with poor overall survival. In addition, we have shown that CTCF haploinsufficiency also occurs in poor prognosis endometrial clear cell carcinomas and has some association with endometrial cancer relapse and metastasis. Using shRNA targeting CTCF to recapitulate CTCF haploinsufficiency, we have identified a novel role for CTCF in the regulation of cellular polarity of endometrial glandular epithelium. Overall, we have identified two novel pro-tumorigenic roles (promoting cell survival and altering cell polarity) for genetic alterations of CTCF in endometrial cancer. PMID:28319062

Systematic Analysis of the Functional Relevance of Nuclear Structure and Mechanics in Breast Cancer Progression

DTIC Science & Technology

2013-07-01

epithelial cells; MDA-MB-231 metastatic breast cancer cells) with systematic alterations in the expression of lamins A, B1, B2, C, and lamin B receptor...LBR). We then evaluated the effect of altered lamin expression on nuclear stiffness in these cell lines. While increased expression of lamin A...caused stiffer, less deformable nuclei, reduction of lamins A/C expression by shRNA reduced nuclear stiffness. The effect of alterations in other lamins

Mutations in the Drosophila neuroglian cell adhesion molecule affect motor neuron pathfinding and peripheral nervous system patterning.

PubMed

Hall, S G; Bieber, A J

1997-03-01

We have identified and characterized three embryonic lethal mutations that alter or abolish expression of Drosophila Neuroglian and have used these mutations to analyze Neuroglian function during development. Neuroglian is a member of the immunoglobulin superfamily. It is expressed by a variety of cell types during embryonic development, including expression on motoneurons and the muscle cells that they innervate. Examination of the nervous systems of neuroglian mutant embryos reveals that motoneurons have altered pathfinding trajectories. Additionally, the sensory cell bodies of the peripheral nervous system display altered morphology and patterning. Using a temperature-sensitive mutation, the phenocritical period for Neuroglian function was determined to occur during late embryogenesis, an interval which coincides with the period during which neuromuscular connections and the peripheral nervous system pattern are established.

Small molecule alteration of RNA sequence in cells and animals.

PubMed

Guan, Lirui; Luo, Yiling; Ja, William W; Disney, Matthew D

2017-10-18

RNA regulation and maintenance are critical for proper cell function. Small molecules that specifically alter RNA sequence would be exceptionally useful as probes of RNA structure and function or as potential therapeutics. Here, we demonstrate a photochemical approach for altering the trinucleotide expanded repeat causative of myotonic muscular dystrophy type 1 (DM1), r(CUG) exp . The small molecule, 2H-4-Ru, binds to r(CUG) exp and converts guanosine residues to 8-oxo-7,8-dihydroguanosine upon photochemical irradiation. We demonstrate targeted modification upon irradiation in cell culture and in Drosophila larvae provided a diet containing 2H-4-Ru. Our results highlight a general chemical biology approach for altering RNA sequence in vivo by using small molecules and photochemistry. Furthermore, these studies show that addition of 8-oxo-G lesions into RNA 3' untranslated regions does not affect its steady state levels. Copyright © 2017 Elsevier Ltd. All rights reserved.

Leptin regulates glutamate and glucose transporters in hypothalamic astrocytes

PubMed Central

Fuente-Martín, Esther; García-Cáceres, Cristina; Granado, Miriam; de Ceballos, María L.; Sánchez-Garrido, Miguel Ángel; Sarman, Beatrix; Liu, Zhong-Wu; Dietrich, Marcelo O.; Tena-Sempere, Manuel; Argente-Arizón, Pilar; Díaz, Francisca; Argente, Jesús; Horvath, Tamas L.; Chowen, Julie A.

2012-01-01

Glial cells perform critical functions that alter the metabolism and activity of neurons, and there is increasing interest in their role in appetite and energy balance. Leptin, a key regulator of appetite and metabolism, has previously been reported to influence glial structural proteins and morphology. Here, we demonstrate that metabolic status and leptin also modify astrocyte-specific glutamate and glucose transporters, indicating that metabolic signals influence synaptic efficacy and glucose uptake and, ultimately, neuronal function. We found that basal and glucose-stimulated electrical activity of hypothalamic proopiomelanocortin (POMC) neurons in mice were altered in the offspring of mothers fed a high-fat diet. In adulthood, increased body weight and fasting also altered the expression of glucose and glutamate transporters. These results demonstrate that whole-organism metabolism alters hypothalamic glial cell activity and suggest that these cells play an important role in the pathology of obesity. PMID:23064363

Mitochondrial DNA 3243A>G heteroplasmy is associated with changes in cytoskeletal protein expression and cell mechanics.

PubMed

Kandel, Judith; Picard, Martin; Wallace, Douglas C; Eckmann, David M

2017-06-01

Mitochondrial and mechanical alterations in cells have both been shown to be hallmarks of human disease. However, little research has endeavoured to establish connections between these two essential features of cells in both functional and dysfunctional situations. In this work, we hypothesized that a specific genetic alteration in mitochondrial function known to cause human disease would trigger changes in cell mechanics. Using a previously characterized set of mitochondrial cybrid cell lines, we examined the relationship between heteroplasmy for the mitochondrial DNA (mtDNA) 3243A>G mutation, the cell cytoskeleton, and resulting cellular mechanical properties. We found that cells with increasing mitochondrial dysfunction markedly differed from one another in gene expression and protein production of various co-regulated cytoskeletal elements. The intracellular positioning and organization of actin also differed across cell lines. To explore the relationship between these changes and cell mechanics, we then measured cellular mechanical properties using atomic force microscopy and found that cell stiffness correlated with gene expression data for known determinants of cell mechanics, γ-actin, α-actinin and filamin A. This work points towards a mechanism linking mitochondrial genetics to single-cell mechanical properties. The transcriptional and structural regulation of cytoskeletal components by mitochondrial function may explain why energetic and mechanical alterations often coexist in clinical conditions. © 2017 The Author(s).

Alterations in adaptive immunity persist during long-duration spaceflight.

PubMed

Crucian, Brian; Stowe, Raymond P; Mehta, Satish; Quiriarte, Heather; Pierson, Duane; Sams, Clarence

2015-01-01

It is currently unknown whether immune system alterations persist during long-duration spaceflight. In this study various adaptive immune parameters were assessed in astronauts at three intervals during 6-month spaceflight on board the International Space Station (ISS). To assess phenotypic and functional immune system alterations in astronauts participating in 6-month orbital spaceflight. Blood was collected before, during, and after flight from 23 astronauts participating in 6-month ISS expeditions. In-flight samples were returned to Earth within 48 h of collection for immediate analysis. Assays included peripheral leukocyte distribution, T-cell function, virus-specific immunity, and mitogen-stimulated cytokine production profiles. Redistribution of leukocyte subsets occurred during flight, including an elevated white blood cell (WBC) count and alterations in CD8 + T-cell maturation. A reduction in general T-cell function (both CD4 + and CD8 + ) persisted for the duration of the 6-month spaceflights, with differential responses between mitogens suggesting an activation threshold shift. The percentage of CD4 + T cells capable of producing IL-2 was depressed after landing. Significant reductions in mitogen-stimulated production of IFNγ, IL-10, IL-5, TNFα, and IL-6 persisted during spaceflight. Following lipopolysaccharide (LPS) stimulation, production of IL-10 was reduced, whereas IL-8 production was increased during flight. The data indicated that immune alterations persist during long-duration spaceflight. This phenomenon, in the absence of appropriate countermeasures, has the potential to increase specific clinical risks for crewmembers during exploration-class deep space missions.

Alterations in adaptive immunity persist during long-duration spaceflight

PubMed Central

Crucian, Brian; Stowe, Raymond P; Mehta, Satish; Quiriarte, Heather; Pierson, Duane; Sams, Clarence

2015-01-01

Background: It is currently unknown whether immune system alterations persist during long-duration spaceflight. In this study various adaptive immune parameters were assessed in astronauts at three intervals during 6-month spaceflight on board the International Space Station (ISS). AIMS: To assess phenotypic and functional immune system alterations in astronauts participating in 6-month orbital spaceflight. Methods: Blood was collected before, during, and after flight from 23 astronauts participating in 6-month ISS expeditions. In-flight samples were returned to Earth within 48 h of collection for immediate analysis. Assays included peripheral leukocyte distribution, T-cell function, virus-specific immunity, and mitogen-stimulated cytokine production profiles. Results: Redistribution of leukocyte subsets occurred during flight, including an elevated white blood cell (WBC) count and alterations in CD8+ T-cell maturation. A reduction in general T-cell function (both CD4+ and CD8+) persisted for the duration of the 6-month spaceflights, with differential responses between mitogens suggesting an activation threshold shift. The percentage of CD4+ T cells capable of producing IL-2 was depressed after landing. Significant reductions in mitogen-stimulated production of IFNγ, IL-10, IL-5, TNFα, and IL-6 persisted during spaceflight. Following lipopolysaccharide (LPS) stimulation, production of IL-10 was reduced, whereas IL-8 production was increased during flight. Conclusions: The data indicated that immune alterations persist during long-duration spaceflight. This phenomenon, in the absence of appropriate countermeasures, has the potential to increase specific clinical risks for crewmembers during exploration-class deep space missions. PMID:28725716

Spacelab Life Sciences 1 - Dedicated life sciences mission

NASA Technical Reports Server (NTRS)

Womack, W. D.

1990-01-01

The Spacelab Life Sciences 1 (SLS-1) mission is discussed, and an overview of the SLS-1 Spacelab configuration is shown. Twenty interdisciplinary experiments, planned for this mission, are intended to explore the early stages of human and animal physiological adaptation to space flight conditions. Biomedical and gravitational biology experiments include cardiovascular and cardiopulmonary deconditioning, altered vestibular functions, altered metabolic functions (including altered fluid-electrolyte regulation), muscle atrophy, bone demineralization, decreased red blood cell mass, and altered immunologic responses.

Prenatal alcohol exposure and cellular differentiation: a role for Polycomb and Trithorax group proteins in FAS phenotypes?

PubMed

Veazey, Kylee J; Muller, Daria; Golding, Michael C

2013-01-01

Exposure to alcohol significantly alters the developmental trajectory of progenitor cells and fundamentally compromises tissue formation (i.e., histogenesis). Emerging research suggests that ethanol can impair mammalian development by interfering with the execution of molecular programs governing differentiation. For example, ethanol exposure disrupts cellular migration, changes cell-cell interactions, and alters growth factor signaling pathways. Additionally, ethanol can alter epigenetic mechanisms controlling gene expression. Normally, lineage-specific regulatory factors (i.e., transcription factors) establish the transcriptional networks of each new cell type; the cell's identity then is maintained through epigenetic alterations in the way in which the DNA encoding each gene becomes packaged within the chromatin. Ethanol exposure can induce epigenetic changes that do not induce genetic mutations but nonetheless alter the course of fetal development and result in a large array of patterning defects. Two crucial enzyme complexes--the Polycomb and Trithorax proteins--are central to the epigenetic programs controlling the intricate balance between self-renewal and the execution of cellular differentiation, with diametrically opposed functions. Prenatal ethanol exposure may disrupt the functions of these two enzyme complexes, altering a crucial aspect of mammalian differentiation. Characterizing the involvement of Polycomb and Trithorax group complexes in the etiology of fetal alcohol spectrum disorders will undoubtedly enhance understanding of the role that epigenetic programming plays in this complex disorder.

Comparison of the Functional microRNA Expression in Immune Cell Subsets of Neonates and Adults

PubMed Central

Yu, Hong-Ren; Hsu, Te-Yao; Huang, Hsin-Chun; Kuo, Ho-Chang; Li, Sung-Chou; Yang, Kuender D.; Hsieh, Kai-Sheng

2016-01-01

Diversity of biological molecules in newborn and adult immune cells contributes to differences in cell function and atopic properties. Micro RNAs (miRNAs) are reported to involve in the regulation of immune system. Therefore, determining the miRNA expression profile of leukocyte subpopulations is important for understanding immune system regulation. In order to explore the unique miRNA profiling that contribute to altered immune in neonates, we comprehensively analyzed the functional miRNA signatures of eight leukocyte subsets (polymorphonuclear cells, monocytes, CD4+ T cells, CD8+ T cells, natural killer cells, B cells, plasmacytoid dendritic cells, and myeloid dendritic cells) from both neonatal and adult umbilical cord and peripheral blood samples, respectively. We observed distinct miRNA profiles between adult and neonatal blood leukocyte subsets, including unique miRNA signatures for each cell lineage. Leukocyte miRNA signatures were altered after stimulation. Adult peripheral leukocytes had higher let-7b-5p expression levels compared to neonatal cord leukocytes across multiple subsets, irrespective of stimulation. Transfecting neonatal monocytes with a let-7b-5p mimic resulted in a reduction of LPS-induced interleukin (IL)-6 and TNF-α production, while transfection of a let-7b-5p inhibitor into adult monocytes enhanced IL-6 and TNF-α production. With this functional approach, we provide intact differential miRNA expression profiling of specific immune cell subsets between neonates and adults. These studies serve as a basis to further understand the altered immune response observed in neonates and advance the development of therapeutic strategies. PMID:28066425

Altered Expression of ZO-1 and ZO-2 in Sertoli Cells and Loss of Blood-Testis Barrier Integrity in Testicular Carcinoma In Situ1

PubMed Central

Fink, Cornelia; Weigel, Roswitha; Hembes, Tanja; Lauke-Wettwer, Heidrun; Kliesch, Sabine; Bergmann, Martin; Brehm, Ralph H

2006-01-01

Abstract Carcinoma in situ (CIS) is the noninvasive precursor of most human testicular germ cell tumors. In normal seminiferous epithelium, specialized tight junctions between Sertoli cells constitute the major component of the blood-testis barrier. Sertoli cells associated with CIS exhibit impaired maturation status, but their functional significance remains unknown. The aim was to determine whether the blood-testis barrier is morphologically and/or functionally altered. We investigated the expression and distribution pattern of the tight junction proteins zonula occludens (ZO) 1 and 2 in normal seminiferous tubules compared to tubules showing CIS. In normal tubules, ZO-1 and ZO-2 immunostaining was observed at the blood-testis barrier region of adjacent Sertoli cells. Within CIS tubules, ZO-1 and ZO-2 immunoreactivity was reduced at the blood-testis barrier region, but spread to stain the Sertoli cell cytoplasm. Western blot analysis confirmed ZO-1 and ZO-2, and their respective mRNA were shown by RT-PCR. Additionally, we assessed the functional integrity of the blood-testis barrier by lanthanum tracer study. Lanthanum permeated tight junctions in CIS tubules, indicating disruption of the blood-testis barrier. In conclusion, Sertoli cells associated with CIS show an altered distribution of ZO-1 and ZO-2 and lose their blood-testis barrier function. PMID:17217619

Altered Memory Circulating T Follicular Helper-B Cell Interaction in Early Acute HIV Infection

PubMed Central

Muir, Roshell; Metcalf, Talibah; Tardif, Virginie; Takata, Hiroshi; Phanuphak, Nittaya; Kroon, Eugene; Colby, Donn J.; Trichavaroj, Rapee; Valcour, Victor; Robb, Merlin L.; Michael, Nelson L.; Ananworanich, Jintanat; Trautmann, Lydie; Haddad, Elias K.

2016-01-01

The RV254 cohort of HIV-infected very early acute (4thG stage 1 and 2) (stage 1/2) and late acute (4thG stage 3) (stage 3) individuals was used to study T helper- B cell responses in acute HIV infection and the impact of early antiretroviral treatment (ART) on T and B cell function. To investigate this, the function of circulating T follicular helper cells (cTfh) from this cohort was examined, and cTfh and memory B cell populations were phenotyped. Impaired cTfh cell function was observed in individuals treated in stage 3 when compared to stage 1/2. The cTfh/B cell cocultures showed lower B cell survival and IgG secretion at stage 3 compared to stage 1/2. This coincided with lower IL-10 and increased RANTES and TNF-α suggesting a role for inflammation in altering cTfh and B cell responses. Elevated plasma viral load in stage 3 was found to correlate with decreased cTfh-mediated B cell IgG production indicating a role for increased viremia in cTfh impairment and dysfunctional humoral response. Phenotypic perturbations were also evident in the mature B cell compartment, most notably a decrease in resting memory B cells in stage 3 compared to stage 1/2, coinciding with higher viremia. Our coculture assay also suggested that intrinsic memory B cell defects could contribute to the impaired response despite at a lower level. Overall, cTfh-mediated B cell responses are significantly altered in stage 3 compared to stage 1/2, coinciding with increased inflammation and a reduction in memory B cells. These data suggest that early ART for acutely HIV infected individuals could prevent immune dysregulation while preserving cTfh function and B cell memory. PMID:27463374

Changes in Nutritional Status Impact Immune Cell Metabolism and Function.

PubMed

Alwarawrah, Yazan; Kiernan, Kaitlin; MacIver, Nancie J

2018-01-01

Immune cell function and metabolism are closely linked. Many studies have now clearly demonstrated that alterations in cellular metabolism influence immune cell function and that, conversely, immune cell function determines the cellular metabolic state. Less well understood, however, are the effects of systemic metabolism or whole organism nutritional status on immune cell function and metabolism. Several studies have demonstrated that undernutrition is associated with immunosuppression, which leads to both increased susceptibility to infection and protection against several types of autoimmune disease, whereas overnutrition is associated with low-grade, chronic inflammation that increases the risk of metabolic and cardiovascular disease, promotes autoreactivity, and disrupts protective immunity. Here, we review the effects of nutritional status on immunity and highlight the effects of nutrition on circulating cytokines and immune cell populations in both human studies and mouse models. As T cells are critical members of the immune system, which direct overall immune response, we will focus this review on the influence of systemic nutritional status on T cell metabolism and function. Several cytokines and hormones have been identified which mediate the effects of nutrition on T cell metabolism and function through the expression and action of key regulatory signaling proteins. Understanding how T cells are sensitive to both inadequate and overabundant nutrients may enhance our ability to target immune cell metabolism and alter immunity in both malnutrition and obesity.

Role of macrophages in the altered epithelial function during a type 2 immune response induced by enteric nematode infection

USDA-ARS?s Scientific Manuscript database

Two major functions of the intestinal epithelium are to act as a physical barrier and to regulate the movement of nutrients, ions and fluid. Nematode infection induces alterations in smooth and epithelial cell function, including increased fluid in the intestinal lumen, which are attributed to a ST...

Comparative studies of cellular viability levels on 2D and 3D in vitro culture matrices.

PubMed

Gargotti, M; Lopez-Gonzalez, U; Byrne, H J; Casey, A

2018-02-01

In this study, the cellular viability and function of immortalized human cervical and dermal cells are monitored and compared in conventional 2D and two commercial 3D membranes, Collagen and Geltrex, of varying working concentration and volume. Viability was monitored with the aid of the Alamar Blue assay, cellular morphology was monitored with confocal microscopy, and cell cycle studies and cell death mechanism studies were performed with flow cytometry. The viability studies showed apparent differences between the 2D and 3D culture systems, the differences attributed in part to the physical transition from 2D to 3D environment causing alterations to effective resazurin concentration, uptake and conversion rates, which was dependent on exposure time, but also due to the effect of the membrane itself on cellular function. These effects were verified by flow cytometry, in which no significant differences in viable cell numbers between 2D and 3D systems were observed after 24 h culture. The results showed the observed effect was different after shorter exposure periods, was also dependent on working concentration of the 3D system and could be mediated by altering the culture vessel size. Cell cycle analysis revealed cellular function could be altered by growth on the 3D substrates and the alterations were noted to be dependent on 3D membrane concentration. The use of 3D culture matrices has been widely interpreted to result in "improved viability levels" or "reduced" toxicity or cellular "resistance" compared to cells cultured on traditional 2D systems. The results of this study show that cellular health and viability levels are not altered by culture in 3D environments, but their normal cycle can be altered as indicated in the cell cycle studies performed and such variations must be accounted for in studies employing 3D membranes for in vitro cellular screening.

Roles of miRNAs in microcystin-LR-induced Sertoli cell toxicity

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

Zhou, Yuan; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu 210093; Wang, Hui

2015-08-15

Microcystin (MC)-LR, a cyclic heptapeptide, is a potent reproductive system toxin. To understand the molecular mechanisms of MC-induced reproductive system cytotoxicity, we evaluated global changes of miRNA and mRNA expression in mouse Sertoli cells following MC-LR treatment. Our results revealed that the exposure to MC-LR resulted in an altered miRNA expression profile that might be responsible for the modulation of mRNA expression. Bio-functional analysis indicated that the altered genes were involved in specific cellular processes, including cell death and proliferation. Target gene analysis suggested that junction injury in Sertoli cells exposed to MC-LR might be mediated by miRNAs through themore » regulation of the Sertoli cell-Sertoli cell pathway. Collectively, these findings may enhance our understanding on the modes of action of MC-LR on mouse Sertoli cells as well as the molecular mechanisms underlying the toxicity of MC-LR on the male reproductive system. - Highlights: • miRNAs were altered in Sertoli cells exposed to MC-LR. • Alerted genes were involved in different cell functions including the cell morphology. • MC-LR adversely affected Sertoli cell junction formation through the regulating miRNAs.« less

Threshold-dependent cooperativity of Pdx1 and Oc1 in pancreatic progenitors establishes competency for endocrine differentiation and β-cell function

PubMed Central

Wright, Christopher V.E.; Won, Kyoung-Jae

2016-01-01

Summary Pdx1 and Oc1 are co-expressed in multipotent pancreatic progenitors and regulate the pro-endocrine gene Neurog3. Their expression diverges in later organogenesis, with Oc1 absent from hormone+ cells and Pdx1 maintained in mature β cells. In a classical genetic test for cooperative functional interactions, we derived mice with combined Pdx1 and Oc1 heterozygosity. Endocrine development in double-heterozygous pancreata was normal at embryonic day (e)13.5, but defects in specification and differentiation were apparent at e15.5, the height of the second wave of differentiation. Pancreata from double heterozygotes showed alterations in the expression of genes crucial for β-cell development and function, decreased numbers and altered allocation of Neurog3-expressing endocrine progenitors, and defective endocrine differentiation. Defects in islet gene expression and β-cell function persisted in double heterozygous neonates. These results suggest that Oc1 and Pdx1 cooperate prior to their divergence, in pancreatic progenitors, to allow for proper differentiation and functional maturation of β cells. PMID:27292642

Disordered follicle development

PubMed Central

Chang, R. Jeffrey; Cook-Andersen, Heidi

2013-01-01

Alterations of ovarian follicle morphology and function have been well documented in women with PCOS. These include increased numbers of growing preantral follicles, failure of follicle growth beyond the mid-antral stage, evidence of granulosa call degeneration, and theca cell hyperplasia. Functional abnormalities include paradoxical granulosa cell hyperresponsiveness to FSH which is clinically linked to ovarian hyperstimulation during ovulation induction. In addition, there is likely a primary theca cell defect that accounts for the majority of excess androgen production in this disorder. The precise mechanisms responsible for altered follicle function are not completely clear. However, several factors appear to influence normal advancement of follicle development as well as impair ovarian steroidogenesis. These include intra- as well as extraovarian influences that distort normal ovarian growth and disrupt steroid production by follicle cells. PMID:22874072

Changes in bone marrow innate lymphoid cell subsets in monoclonal gammopathy: target for IMiD therapy.

PubMed

Kini Bailur, Jithendra; Mehta, Sameet; Zhang, Lin; Neparidze, Natalia; Parker, Terri; Bar, Noffar; Anderson, Tara; Xu, Mina L; Dhodapkar, Kavita M; Dhodapkar, Madhav V

2017-11-28

Altered number, subset composition, and function of bone marrow innate lymphoid cells are early events in monoclonal gammopathies.Pomalidomide therapy leads to reduction in Ikzf1 and Ikzf3 and enhanced human innate lymphoid cell function in vivo.

Mitochondria link metabolism and epigenetics in haematopoiesis.

PubMed

Schell, John C; Rutter, Jared

2017-05-31

Due to their varied metabolic and signalling roles, mitochondria are important in mediating cell behaviour. By altering mitochondrial function, two studies now identify metabolite-induced epigenetic changes that have profound effects on haematopoietic stem cell fate and function.

Mutational Analysis of Drosophila Basigin Function in the Visual System

PubMed Central

Munro, Michelle; Akkam, Yazan; Curtin, Kathryn D.

2009-01-01

Drosophila basigin is a cell-surface glycoprotein of the Ig superfamily and a member of a protein family that includes mammalian EMMPRIN/CD147/basigin, neuroplastin, and embigin. Our previous work on Drosophila basigin has shown that it is required for normal photoreceptor cell structure and normal neuron-glia interaction in the fly visual system. Specifically, the photoreceptor neurons of mosaic animals that are mutant in the eye for basigin show altered cell structure with nuclei, mitochondria and rER misplaced and variable axon diameter compared to wild-type. In addition, glia cells in the optic lamina that contact photoreceptor axons are misplaced and show altered structure. All these defects are rescued by expression of either transgenic fly basigin or transgenic mouse basigin in the photoreceptors demonstrating that mouse basigin can functionally replace fly basigin. To determine what regions of the basigin protein are required for each of these functions, we have created mutant basigin transgenes coding for proteins that are altered in conserved residues, introduced these into the fly genome, and tested them for their ability to rescue both photoreceptor cell structure defects and neuron-glia interaction defects of basigin. The results suggest that the highly conserved transmembrane domain and the extracellular domains are crucial for basigin function in the visual system while the short intracellular tail may not play a role in these functions. PMID:19782733

Epitranscriptomic profiling across cell types reveals associations between APOBEC1-mediated RNA editing, gene expression outcomes, and cellular function.

PubMed

Rayon-Estrada, Violeta; Harjanto, Dewi; Hamilton, Claire E; Berchiche, Yamina A; Gantman, Emily Conn; Sakmar, Thomas P; Bulloch, Karen; Gagnidze, Khatuna; Harroch, Sheila; McEwen, Bruce S; Papavasiliou, F Nina

2017-12-12

Epitranscriptomics refers to posttranscriptional alterations on an mRNA sequence that are dynamic and reproducible, and affect gene expression in a similar way to epigenetic modifications. However, the functional relevance of those modifications for the transcript, the cell, and the organism remain poorly understood. Here, we focus on RNA editing and show that Apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-1 (APOBEC1), together with its cofactor RBM47, mediates robust editing in different tissues. The majority of editing events alter the sequence of the 3'UTR of targeted transcripts, and we focus on one cell type (monocytes) and on a small set of highly edited transcripts within it to show that editing alters gene expression by modulating translation (but not RNA stability or localization). We further show that specific cellular processes (phagocytosis and transendothelial migration) are enriched for transcripts that are targets of editing and that editing alters their function. Finally, we survey bone marrow progenitors and demonstrate that common monocyte progenitor cells express high levels of APOBEC1 and are susceptible to loss of the editing enzyme. Overall, APOBEC1-mediated transcriptome diversification is required for the fine-tuning of protein expression in monocytes, suggesting an epitranscriptomic mechanism for the proper maintenance of homeostasis in innate immune cells. Copyright © 2017 the Author(s). Published by PNAS.

Host cell subversion by Toxoplasma GRA16, an exported dense granule protein that targets the host cell nucleus and alters gene expression.

PubMed

Bougdour, Alexandre; Durandau, Eric; Brenier-Pinchart, Marie-Pierre; Ortet, Philippe; Barakat, Mohamed; Kieffer, Sylvie; Curt-Varesano, Aurélie; Curt-Bertini, Rose-Laurence; Bastien, Olivier; Coute, Yohann; Pelloux, Hervé; Hakimi, Mohamed-Ali

2013-04-17

After invading host cells, Toxoplasma gondii multiplies within a parasitophorous vacuole (PV) that is maintained by parasite proteins secreted from organelles called dense granules. Most dense granule proteins remain within the PV, and few are known to access the host cell cytosol. We identify GRA16 as a dense granule protein that is exported through the PV membrane and reaches the host cell nucleus, where it positively modulates genes involved in cell-cycle progression and the p53 tumor suppressor pathway. GRA16 binds two host enzymes, the deubiquitinase HAUSP and PP2A phosphatase, which exert several functions, including regulation of p53 and the cell cycle. GRA16 alters p53 levels in a HAUSP-dependent manner and induces nuclear translocation of the PP2A holoenzyme. Additionally, certain GRA16-deficient strains exhibit attenuated virulence, indicating the importance of these host alterations in pathogenesis. Therefore, GRA16 represents a potentially emerging subfamily of exported dense granule proteins that modulate host function. Copyright © 2013 Elsevier Inc. All rights reserved.

Cigarette smoke silences innate lymphoid cell function and facilitates an exacerbated type I interleukin-33-dependent response to infection.

PubMed

Kearley, Jennifer; Silver, Jonathan S; Sanden, Caroline; Liu, Zheng; Berlin, Aaron A; White, Natalie; Mori, Michiko; Pham, Tuyet-Hang; Ward, Christine K; Criner, Gerard J; Marchetti, Nathaniel; Mustelin, Tomas; Erjefalt, Jonas S; Kolbeck, Roland; Humbles, Alison A

2015-03-17

Cigarette smoking is a major risk factor for chronic obstructive pulmonary disease and is presumed to be central to the altered responsiveness to recurrent infection in these patients. We examined the effects of smoke priming underlying the exacerbated response to viral infection in mice. Lack of interleukin-33 (IL-33) signaling conferred complete protection during exacerbation and prevented enhanced inflammation and exaggerated weight loss. Mechanistically, smoke was required to upregulate epithelial-derived IL-33 and simultaneously alter the distribution of the IL-33 receptor ST2. Specifically, smoke decreased ST2 expression on group 2 innate lymphoid cells (ILC2s) while elevating ST2 expression on macrophages and natural killer (NK) cells, thus altering IL-33 responsiveness within the lung. Consequently, upon infection and release, increased local IL-33 significantly amplified type I proinflammatory responses via synergistic modulation of macrophage and NK cell function. Therefore, in COPD, smoke alters the lung microenvironment to facilitate an alternative IL-33-dependent exaggerated proinflammatory response to infection, exacerbating disease. Copyright © 2015 Elsevier Inc. All rights reserved.

Metabolic Reprogramming and Oncogenesis: One Hallmark, Many Organelles.

PubMed

Costa, A S H; Frezza, C

2017-01-01

The process of tumorigenesis can be described by a series of molecular features, among which alteration of cellular metabolism has recently emerged. This metabolic rewiring fulfills the energy and biosynthetic demands of fast proliferating cancer cells and amplifies their metabolic repertoire to survive and proliferate in the poorly oxygenated and nutrient-deprived tumor microenvironment. During the last decade, the complex reprogramming of cancer cell metabolism has been widely investigated, revealing cancer-specific metabolic alterations. These include dysregulation of glucose and glutamine metabolism, alterations of lipid synthesis and oxidation, and a complex rewiring of mitochondrial function. However, mitochondria are not the only metabolically active organelles within the cell, and other organelles, including lysosomes, peroxisomes, and endoplasmic reticulum, harbor components of the metabolic network. Of note, dysregulation of the function of these organelles is increasingly recognized in cancer cells. However, to what extent these organelles contribute to the metabolic reprogramming of cancer is not fully understood. In this review, we describe the main metabolic functions of these organelles and provide insights into how they communicate to orchestrate a coordinated metabolic reprogramming during transformation. © 2017 Elsevier Inc. All rights reserved.

Impact of hyperlipidemia on alloimmunity.

PubMed

Bagley, Jessamyn; Yuan, Jin; Iacomini, John

2017-02-01

Hyperlipidemia is a comorbidity affecting a significant number of transplant patients despite treatment with cholesterol lowering drugs. Recently, it has been shown that hyperlipidemia can significantly alter T-cell responses to cardiac allografts in mice, and graft rejection is accelerated in dyslipidemic mice. Here, we review recent advances in our understanding of hyperlipidemia in graft rejection. Hyperlipidemic mice have significant increases in serum levels of proinflammatory cytokines, and neutralization of interleukin 17 (IL-17) slows graft rejection, suggesting that IL-17 production by Th17 cells was necessary but not sufficient for rejection. Hyperlipidemia also causes an increase in alloreactive T-cell responses prior to antigen exposure. Analysis of peripheral tolerance mechanisms indicated that this was at least in part due to alterations in FoxP3 T cells that led to reduced Treg function and the expansion of FoxP3 CD4 T cells expressing low levels of CD25. Functionally, alterations in Treg function prevented the ability to induce operational tolerance to fully allogeneic heart transplants through costimulatory-molecule blockade, a strategy that requires Tregs. These findings highlight the importance of considering the contribution of inflammatory comorbidities to cardiac allograft rejection, and point to the potential importance of managing hyperlipidemia in the transplant population.

Simulated Microgravity Induced Cytoskeletal Rearrangements are Modulated by Protooncogenes

NASA Technical Reports Server (NTRS)

Melhado, C. D.; Sanford, G. L.; Bosah, F.; Harris-Hooker, S.

1998-01-01

Microgravity is the environment living systems encounter during space flight and gravitational unloading is the effect of this environment on living systems. The cell, being a multiphasic chemical system, is a useful starting point to study the potential impact of gravity unloading on physiological function. In the absence of gravity, sedimentation of organelles including chromosomes, mitochondria, nuclei, the Golgi apparatus, vacuoles, and the endoplasmic reticulum may be affected. Most of these organelles, however, are somewhat held in place by cytoskeleton. Hansen and Igber suggest that intermediate filaments act to stabilize the nuleus against rotational movement, and integrate cell and nuclear structure. The tensegrity theory supports the idea that mechanical or physical forces alters the cytoskeletal structures of a cell resulting in the changes in cell: matrix interactions and receptor-signaling coupling. This type of stress to the cytoskeleton may be largely responsible regulating cell shape, growth, movement and metabolism. Mouse MC3T3 El cells under microgravity exhibited significant cytoskeletal changes and alterations in cell growth. The alterations in cytoskeleton architecture may be due to changes in the expression of actin related proteins or integrins. Philopott and coworkers reported on changes in the distribution of microtubule and cytoskeleton elements in the cells of heart tissue from space flight rats and those centrifuged at 1.7g. Other researchers have showed that microgravity reduced EGF-induced c-fos and c-jun expression compared to 1 g controls. Since c-fos and c-jun are known regulators of cell growth, it is likely that altered signal transduction involving protooncogenes may play a crucial role in the reduced growth and alterations in cytoskeletal arrangements found during space flight. It is clear that a microgravity environment induces a number of changes in cell shape, cell surface molecules, gene expression, and cytoskeletal reorganization. However the underlying mechanism for these cellular changes have not been clearly defined. We examined alterations in endothelial migration, and cytoskeleton architecture (microfilamentous f-actin and vimentin-rich- intermediate filaments) following wounding under simulated microgravity. We also examined the possibility that altered signal transduction pathways, involving protooncogenes, may play a crucial role in microgravity-induced retardation of cell migration and alterations in cytoskeletal organization. We hypothesize that, based on the tensegrity theory, cytoskeletal organization respond to gravitational unloading and through this response, cell behavior, function and gene expression are modified.

Breast cancer cell cyclooxygenase-2 expression alters extracellular matrix structure and function and numbers of cancer associated fibroblasts.

PubMed

Krishnamachary, Balaji; Stasinopoulos, Ioannis; Kakkad, Samata; Penet, Marie-France; Jacob, Desmond; Wildes, Flonne; Mironchik, Yelena; Pathak, Arvind P; Solaiyappan, Meiyappan; Bhujwalla, Zaver M

2017-03-14

Cyclooxygenase-2 (COX-2) is a critically important mediator of inflammation that significantly influences tumor angiogenesis, invasion, and metastasis. We investigated the role of COX-2 expressed by triple negative breast cancer cells in altering the structure and function of the extracellular matrix (ECM). COX-2 downregulation effects on ECM structure and function were investigated using magnetic resonance imaging (MRI) and second harmonic generation (SHG) microscopy of tumors derived from triple negative MDA-MB-231 breast cancer cells, and a derived clone stably expressing a short hairpin (shRNA) molecule downregulating COX-2. MRI of albumin-GdDTPA was used to characterize macromolecular fluid transport in vivo and SHG microscopy was used to quantify collagen 1 (Col1) fiber morphology. COX-2 downregulation decreased Col1 fiber density and altered macromolecular fluid transport. Immunohistochemistry identified significantly fewer activated cancer associated fibroblasts (CAFs) in low COX-2 expressing tumors. Metastatic lung nodules established by COX-2 downregulated cells were infrequent, smaller, and contained fewer Col1 fibers.COX-2 overexpression studies were performed with tumors derived from triple negative SUM-149 breast cancer cells lentivirally transduced to overexpress COX-2. SHG microscopy identified significantly higher Col1 fiber density in COX-2 overexpressing tumors with an increase of CAFs. These data expand upon the roles of COX-2 in shaping the structure and function of the ECM in primary and metastatic tumors, and identify the potential role of COX-2 in modifying the number of CAFs in tumors that may have contributed to the altered ECM.

Src-like adaptor protein (SLAP) regulates B cell receptor levels in a c-Cbl-dependent manner.

PubMed

Dragone, Leonard L; Myers, Margaret D; White, Carmen; Gadwal, Shyam; Sosinowski, Tomasz; Gu, Hua; Weiss, Arthur

2006-11-28

Src-like adaptor protein (SLAP) and c-Cbl recently have been shown to cooperate in regulating T cell receptor (TCR) levels in developing T cells. SLAP also is expressed in developing B cells, and its deficiency leads to alterations in B cell receptor (BCR) levels and B cell development. Hence, we hypothesized that SLAP and c-Cbl may cooperate during B cell development to regulate BCR levels. In mice deficient in both SLAP and c-Cbl, we found that B cell development is altered, suggesting that they function through intersecting pathways. To study the mechanism by which SLAP and c-Cbl alter BCR levels, we coexpressed them in a mature mouse B cell line (Bal-17). First we determined that SLAP associates with proximal components of the BCR complex after stimulation and internalization. Coexpression of SLAP and c-Cbl in Bal-17 led to decreased surface and total BCR levels. This decrease in BCR levels depended on intact Src homology 2 (SH2) and C-terminal domains of SLAP. In addition, a mutation in the SH2 domain of SLAP blocked its colocalization with c-Cbl and the BCR complex, whereas deletion of the C terminus did not affect its localization. Last, coexpression of SLAP and c-Cbl altered BCR complex recycling. This alteration in BCR complex recycling depended on enzymatically active c-Cbl and Src family kinases, as well as the intact SH2 and C-terminal domains of SLAP. These data suggest that SLAP has a conserved function in B and T cells by adapting c-Cbl to the antigen-receptor complex and targeting it for degradation.

Src-like adaptor protein (SLAP) regulates B cell receptor levels in a c-Cbl-dependent manner

PubMed Central

Dragone, Leonard L.; Myers, Margaret D.; White, Carmen; Gadwal, Shyam; Sosinowski, Tomasz; Gu, Hua; Weiss, Arthur

2006-01-01

Src-like adaptor protein (SLAP) and c-Cbl recently have been shown to cooperate in regulating T cell receptor (TCR) levels in developing T cells. SLAP also is expressed in developing B cells, and its deficiency leads to alterations in B cell receptor (BCR) levels and B cell development. Hence, we hypothesized that SLAP and c-Cbl may cooperate during B cell development to regulate BCR levels. In mice deficient in both SLAP and c-Cbl, we found that B cell development is altered, suggesting that they function through intersecting pathways. To study the mechanism by which SLAP and c-Cbl alter BCR levels, we coexpressed them in a mature mouse B cell line (Bal-17). First we determined that SLAP associates with proximal components of the BCR complex after stimulation and internalization. Coexpression of SLAP and c-Cbl in Bal-17 led to decreased surface and total BCR levels. This decrease in BCR levels depended on intact Src homology 2 (SH2) and C-terminal domains of SLAP. In addition, a mutation in the SH2 domain of SLAP blocked its colocalization with c-Cbl and the BCR complex, whereas deletion of the C terminus did not affect its localization. Last, coexpression of SLAP and c-Cbl altered BCR complex recycling. This alteration in BCR complex recycling depended on enzymatically active c-Cbl and Src family kinases, as well as the intact SH2 and C-terminal domains of SLAP. These data suggest that SLAP has a conserved function in B and T cells by adapting c-Cbl to the antigen-receptor complex and targeting it for degradation. PMID:17110436

Oxidative Stress and Maxi Calcium-Activated Potassium (BK) Channels

PubMed Central

Hermann, Anton; Sitdikova, Guzel F.; Weiger, Thomas M.

2015-01-01

All cells contain ion channels in their outer (plasma) and inner (organelle) membranes. Ion channels, similar to other proteins, are targets of oxidative impact, which modulates ion fluxes across membranes. Subsequently, these ion currents affect electrical excitability, such as action potential discharge (in neurons, muscle, and receptor cells), alteration of the membrane resting potential, synaptic transmission, hormone secretion, muscle contraction or coordination of the cell cycle. In this chapter we summarize effects of oxidative stress and redox mechanisms on some ion channels, in particular on maxi calcium-activated potassium (BK) channels which play an outstanding role in a plethora of physiological and pathophysiological functions in almost all cells and tissues. We first elaborate on some general features of ion channel structure and function and then summarize effects of oxidative alterations of ion channels and their functional consequences. PMID:26287261

Bisphenol A exposure leads to specific microRNA alterations in placental cells.

PubMed

Avissar-Whiting, Michele; Veiga, Keila R; Uhl, Kristen M; Maccani, Matthew A; Gagne, Luc A; Moen, Erika L; Marsit, Carmen J

2010-07-01

Exposure to bisphenol A (BPA) has been observed to alter developmental pathways and cell processes, at least in part, through epigenetic mechanisms. This study sought to investigate the effect of BPA on microRNAs (miRNAs) in human placental cells. miRNA microarray was performed following BPA treatment in three immortalized cytotrophoblast cell lines and the results validated using quantitative real-time PCR. For functional analysis, overexpression constructs were stably transfected into cells that were then assayed for changes in proliferation and response to toxicants. Microarray analysis revealed several miRNAs to be significantly altered in response to BPA treatment in two cell lines. Real-time PCR results confirmed that miR-146a was particularly strongly induced and its overexpression in cells led to slower proliferation as well as higher sensitivity to the DNA damaging agent, bleomycin. Overall, these results suggest that BPA can alter miRNA expression in placental cells, a potentially novel mode of BPA toxicity.

Bisphenol A Exposure Leads to Specific MicroRNA Alterations in Placental Cells

PubMed Central

Avissar-Whiting, Michele; Veiga, Keila; Uhl, Kristen; Maccani, Matthew; Gagne, Luc; Moen, Erika; Marsit, Carmen J.

2010-01-01

Exposure to bisphenol-A (BPA) has been observed to alter developmental pathways and cell processes, at least in part, through epigenetic mechanisms. This study sought to investigate the effect of BPA on microRNAs (miRNAs) in human placental cells. miRNA microarray was performed following BPA treatment in three immortalized cytotrophoblast cell lines and the results validated using quantitative real-time PCR. For functional analysis, overexpression constructs were stably transfected into cells that were then assayed for changes in proliferation and response to toxicants. Microarray analysis revealed several miRNAs to be significantly altered in response to BPA treatment in two cell lines. Real-time PCR results confirmed that miR-146a was particularly strongly induced and its overexpression in cells led to slower proliferation as well as higher sensitivity to the DNA damaging agent, bleomycin. Overall, these results suggest that BPA can alter miRNA expression in placental cells, a potentially novel mode of BPA toxicity. PMID:20417706

Deciphering the role of interleukin-22 in metabolic alterations.

PubMed

Sabat, Robert; Wolk, Kerstin

2015-01-01

Inflammatory processes and metabolic alterations are supposed to substantially interact. Recently, cumulating reports describe a profound role of interleukin(IL)-22 in this relationship. IL-22 is a particular kind of immune mediator that is produced by certain lymphocyte populations and regulates the function of several tissue cells but not immune cells. So far, IL-22 was known to plays a fundamental role in the elimination of bacterial infections at border surfaces of the body and to protect tissues from damage. This research highlight article arranges the facts regarding the effects of IL-22 in the context of adiposity and metabolic alterations and postulates a new function of the immune system.

Arsenic Compromises Conducting Airway Epithelial Barrier Properties in Primary Mouse and Immortalized Human Cell Cultures

PubMed Central

Sherwood, Cara L.; Liguori, Andrew E.; Olsen, Colin E.; Lantz, R. Clark; Burgess, Jefferey L.; Boitano, Scott

2013-01-01

Arsenic is a lung toxicant that can lead to respiratory illness through inhalation and ingestion, although the most common exposure is through contaminated drinking water. Lung effects reported from arsenic exposure include lung cancer and obstructive lung disease, as well as reductions in lung function and immune response. As part of their role in innate immune function, airway epithelial cells provide a barrier that protects underlying tissue from inhaled particulates, pathogens, and toxicants frequently found in inspired air. We evaluated the effects of a five-day exposure to environmentally relevant levels of arsenic {<4μM [~300 μg/L (ppb)] as NaAsO2} on airway epithelial barrier function and structure. In a primary mouse tracheal epithelial (MTE) cell model we found that both micromolar (3.9 μM) and submicromolar (0.8 μM) arsenic concentrations reduced transepithelial resistance, a measure of barrier function. Immunofluorescent staining of arsenic-treated MTE cells showed altered patterns of localization of the transmembrane tight junction proteins claudin (Cl) Cl-1, Cl-4, Cl-7 and occludin at cell-cell contacts when compared with untreated controls. To better quantify arsenic-induced changes in tight junction transmembrane proteins we conducted arsenic exposure experiments with an immortalized human bronchial epithelial cell line (16HBE14o-). We found that arsenic exposure significantly increased the protein expression of Cl-4 and occludin as well as the mRNA levels of Cl-4 and Cl-7 in these cells. Additionally, arsenic exposure resulted in altered phosphorylation of occludin. In summary, exposure to environmentally relevant levels of arsenic can alter both the function and structure of airway epithelial barrier constituents. These changes likely contribute to the observed arsenic-induced loss in basic innate immune defense and increased infection in the airway. PMID:24349408

Short Term, Low Dose Simvastatin Pretreatment Alters Memory Immune Function Following Secondary Staphylococcus aureus Infection.

PubMed

Smelser, Lisa K; Walker, Callum; Burns, Erin M; Curry, Michael; Black, Nathanael; Metzler, Jennifer A; McDowell, Susan A; Bruns, Heather A

Statins are potent modulators of immune responses, resulting in their ability to enhance host survival from primary bacterial infections. Alterations in primary immune responses that may be beneficial for survival following infection may also result in alterations in the generation of the immunologic memory response and subsequently affect immune responses mounted during secondary bacterial infection. In this study, we report that levels of total serum IgG2c, following primary infection, were decreased in simvastatin pretreated mice, and investigate the effect of simvastatin treatment, prior to primary infection, on immune responses activated during secondary S. aureus infection. A secondary infection model was implemented whereby simvastatin pretreated and control mice were reinfected with S. aureus 14 days after primary infection, with no additional simvastatin treatment, and assessed for survival and alterations in immune function. While survivability to secondary S. aureus infection was not different between simvastatin pretreated and control mice, memory B and T lymphocyte functions were altered. Memory B cells, isolated 14 days after secondary infection, from simvastatin pretreated mice and stimulated ex vivo produced increased levels of IgG1 compared to memory B cells isolated from control mice, while levels of IgM and IgG2c remained similar. Furthermore, memory B and T lymphocytes from simvastatin pretreated mice exhibited a decreased proliferative response when stimulated ex vivo compared to memory cells isolated from control mice. These findings demonstrate the ability of a short term, low dose simvastatin treatment to modulate memory immune function.

Glucocorticoid action in human corneal epithelial cells establishes roles for corticosteroids in wound healing and barrier function of the eye.

PubMed

Kadmiel, Mahita; Janoshazi, Agnes; Xu, Xiaojiang; Cidlowski, John A

2016-11-01

Glucocorticoids play diverse roles in almost all physiological systems of the body, including both anti-inflammatory and immunosuppressive roles. Synthetic glucocorticoids are one of the most widely prescribed drugs and are used in the treatment of conditions such as autoimmune diseases, allergies, ocular disorders and certain types of cancers. In the interest of investigating glucocorticoid actions in the cornea of the eye, we established that multiple cell types in mouse corneas express functional glucocorticoid receptor (GR) with corneal epithelial cells having robust expression. To define glucocorticoid actions in a cell type-specific manner, we employed immortalized human corneal epithelial (HCE) cell line to define the glucocorticoid transcriptome and elucidated its functions in corneal epithelial cells. Over 4000 genes were significantly regulated within 6 h of dexamethasone treatment, and genes associated with cell movement, cytoskeletal remodeling and permeability were highly regulated. Real-time in vitro wound healing assays revealed that glucocorticoids delay wound healing by attenuating cell migration. These functional alterations were associated with cytoskeletal remodeling at the wounded edge of a scratch-wounded monolayer. However, glucocorticoid treatment improved the organization of tight-junction proteins and enhanced the epithelial barrier function. Our results demonstrate that glucocorticoids profoundly alter corneal epithelial gene expression and many of these changes likely impact both wound healing and epithelial cell barrier function. Published by Elsevier Ltd.

Metabolomics reveals mycoplasma contamination interferes with the metabolism of PANC-1 cells.

PubMed

Yu, Tao; Wang, Yongtao; Zhang, Huizhen; Johnson, Caroline H; Jiang, Yiming; Li, Xiangjun; Wu, Zeming; Liu, Tian; Krausz, Kristopher W; Yu, Aiming; Gonzalez, Frank J; Huang, Min; Bi, Huichang

2016-06-01

Mycoplasma contamination is a common problem in cell culture and can alter cellular functions. Since cell metabolism is either directly or indirectly involved in every aspect of cell function, it is important to detect changes to the cellular metabolome after mycoplasma infection. In this study, liquid chromatography mass spectrometry (LC/MS)-based metabolomics was used to investigate the effect of mycoplasma contamination on the cellular metabolism of human pancreatic carcinoma cells (PANC-1). Multivariate analysis demonstrated that mycoplasma contamination induced significant metabolic changes in PANC-1 cells. Twenty-three metabolites were identified and found to be involved in arginine and purine metabolism and energy supply. This study demonstrates that mycoplasma contamination significantly alters cellular metabolite levels, confirming the compelling need for routine checking of cell cultures for mycoplasma contamination, particularly when used for metabolomics studies. Graphical abstract Metabolomics reveals mycoplasma contamination changes the metabolome of PANC-1 cells.

Seed Germination and Seedling Growth under Simulated Microgravity Causes Alterations in Plant Cell Proliferation and Ribosome Biogenesis

NASA Astrophysics Data System (ADS)

Matía, Isabel; van Loon, Jack W. A.; Carnero-Díaz, Eugénie; Marco, Roberto; Medina, Francisco Javier

2009-01-01

The study of the modifications induced by altered gravity in functions of plant cells is a valuable tool for the objective of the survival of terrestrial organisms in conditions different from those of the Earth. We have used the system "cell proliferation-ribosome biogenesis", two inter-related essential cellular processes, with the purpose of studying these modifications. Arabidopsis seedlings belonging to a transformed line containing the reporter gene GUS under the control of the promoter of the cyclin gene CYCB1, a cell cycle regulator, were grown in a Random Positioning Machine, a device known to accurately simulate microgravity. Samples were taken at 2, 4 and 8 days after germination and subjected to biometrical analysis and cellular morphometrical, ultrastructural and immunocytochemical studies in order to know the rates of cell proliferation and ribosome biogenesis, plus the estimation of the expression of the cyclin gene, as an indication of the state of cell cycle regulation. Our results show that cells divide more in simulated microgravity in a Random Positioning Machine than in control gravity, but the cell cycle appears significantly altered as early as 2 days after germination. Furthermore, higher proliferation is not accompanied by an increase in ribosome synthesis, as is the rule on Earth, but the functional markers of this process appear depleted in simulated microgravity-grown samples. Therefore, the alteration of the gravitational environmental conditions results in a considerable stress for plant cells, including those not specialized in gravity perception.

Diabetes-Induced Dysfunction of Mitochondria and Stem Cells in Skeletal Muscle and the Nervous System

PubMed Central

Fujimaki, Shin; Kuwabara, Tomoko

2017-01-01

Diabetes mellitus is one of the most common metabolic diseases spread all over the world, which results in hyperglycemia caused by the breakdown of insulin secretion or insulin action or both. Diabetes has been reported to disrupt the functions and dynamics of mitochondria, which play a fundamental role in regulating metabolic pathways and are crucial to maintain appropriate energy balance. Similar to mitochondria, the functions and the abilities of stem cells are attenuated under diabetic condition in several tissues. In recent years, several studies have suggested that the regulation of mitochondria functions and dynamics is critical for the precise differentiation of stem cells. Importantly, physical exercise is very useful for preventing the diabetic alteration by improving the functions of both mitochondria and stem cells. In the present review, we provide an overview of the diabetic alterations of mitochondria and stem cells and the preventive effects of physical exercise on diabetes, focused on skeletal muscle and the nervous system. We propose physical exercise as a countermeasure for the dysfunction of mitochondria and stem cells in several target tissues under diabetes complication and to improve the physiological function of patients with diabetes, resulting in their quality of life being maintained. PMID:29036909

Diabetes-Induced Dysfunction of Mitochondria and Stem Cells in Skeletal Muscle and the Nervous System.

PubMed

Fujimaki, Shin; Kuwabara, Tomoko

2017-10-14

Diabetes mellitus is one of the most common metabolic diseases spread all over the world, which results in hyperglycemia caused by the breakdown of insulin secretion or insulin action or both. Diabetes has been reported to disrupt the functions and dynamics of mitochondria, which play a fundamental role in regulating metabolic pathways and are crucial to maintain appropriate energy balance. Similar to mitochondria, the functions and the abilities of stem cells are attenuated under diabetic condition in several tissues. In recent years, several studies have suggested that the regulation of mitochondria functions and dynamics is critical for the precise differentiation of stem cells. Importantly, physical exercise is very useful for preventing the diabetic alteration by improving the functions of both mitochondria and stem cells. In the present review, we provide an overview of the diabetic alterations of mitochondria and stem cells and the preventive effects of physical exercise on diabetes, focused on skeletal muscle and the nervous system. We propose physical exercise as a countermeasure for the dysfunction of mitochondria and stem cells in several target tissues under diabetes complication and to improve the physiological function of patients with diabetes, resulting in their quality of life being maintained.

More than a drainage fluid: the role of CSF in signaling in the brain and other effects on brain tissue.

PubMed

Illes, Sebastian

2017-01-01

Current progress in neuroscience demonstrates that the brain is not an isolated organ and is influenced by the systemic environment and extracerebral processes within the body. In view of this new concept, blood and cerebrospinal fluid (CSF) are important body fluids linking extracerebral and intracerebral processes. For decades, substantial evidence has been accumulated indicating that CSF modulates brain states and influences behavior as well as cognition. This chapter provides an overview of how CSF directly modulates the function of different types of brain cells, such as neurons, neural stem cells, and CSF-contacting cells. Alterations in CSF content occur in most pathologic central nervous system (CNS) conditions. In a classic view, the function of CSF is to drain waste products and detrimental factors derived from diseased brain parenchyma. This chapter presents examples for how intra- and extracerebral pathologic processes lead to alterations in the CSF content. Current knowledge about how pathologically altered CSF influences the functionality of brain cells will be presented. Thereby, it becomes evident that CSF has more than a drainage function and has a causal role for the etiology and pathogenesis of different CNS diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

Regulation of human genome expression and RNA splicing by human papillomavirus 16 E2 protein.

PubMed

Gauson, Elaine J; Windle, Brad; Donaldson, Mary M; Caffarel, Maria M; Dornan, Edward S; Coleman, Nicholas; Herzyk, Pawel; Henderson, Scott C; Wang, Xu; Morgan, Iain M

2014-11-01

Human papillomavirus 16 (HPV16) is causative in human cancer. The E2 protein regulates transcription from and replication of the viral genome; the role of E2 in regulating the host genome has been less well studied. We have expressed HPV16 E2 (E2) stably in U2OS cells; these cells tolerate E2 expression well and gene expression analysis identified 74 genes showing differential expression specific to E2. Analysis of published gene expression data sets during cervical cancer progression identified 20 of the genes as being altered in a similar direction as the E2 specific genes. In addition, E2 altered the splicing of many genes implicated in cancer and cell motility. The E2 expressing cells showed no alteration in cell growth but were altered in cell motility, consistent with the E2 induced altered splicing predicted to affect this cellular function. The results present a model system for investigating E2 regulation of the host genome. Copyright © 2014 Elsevier Inc. All rights reserved.

Experiments with suspended cells on the Space Shuttle

NASA Technical Reports Server (NTRS)

Morrison, D. R.; Chapes, S. K.; Guikema, J. A.; Spooner, B. S.; Lewis, M. L.

1992-01-01

Spaceflight experiments since 1981 have demonstrated that certain cell functions are altered by micro-g. Biophysical models suggest that cell membranes and organelles should not be affected directly by gravity, however, the chemical microenvironment surrounding the cell and molecular transport could be altered by reduced gravity. Most experiments have used suspended live cells in small chambers without stirring or medium exchange. Flight results include increased attachment of anchorage-dependent human cells to collagen coated microcarriers, reduced secretion of growth hormone from pituitary cells, decreased mitogenic response of lymphocytes, increased Interferon-alpha by lymphocytes, increased Interleukin-1 and Tumor Necrosis Factor secretion by macrophages. Related experiments on cells immediately postflight and on procaryotic cells have shown significant changes in secretory capacity, cell proliferation, differentiation and development. Postulated mechanism include altered cell-cell interactions, altered calcium ion transport, effects on cell cytoskeleton, transport of transmitters and interactions with receptors. The discussion includes use of new molecular methods, considerations for cell environmental control and a preview of several experiments planned for the Shuttle and Spacelab flights to study the basic effects of microgravity on cellular physiology and potential interactions of spaceflight with radiation damage and cellular repair mechanisms.

Alteration of a second putative fusion peptide of structural glycoprotein E2 of Classical Swine Fever Virus alters virus replication and virulence in swine

USDA-ARS?s Scientific Manuscript database

E2, the major envelope glycoprotein of Classical Swine Fever Virus (CSFV), is involved in several critical virus functions including cell attachment, host range susceptibility, and virulence in natural hosts. Functional structural analysis of E2 based on Wimley-White interfacial hydrophobicity dis...

Diffuse large B-cell lymphoma patient-derived xenograft models capture the molecular and biological heterogeneity of the disease.

PubMed

Chapuy, Bjoern; Cheng, Hongwei; Watahiki, Akira; Ducar, Matthew D; Tan, Yuxiang; Chen, Linfeng; Roemer, Margaretha G M; Ouyang, Jing; Christie, Amanda L; Zhang, Liye; Gusenleitner, Daniel; Abo, Ryan P; Farinha, Pedro; von Bonin, Frederike; Thorner, Aaron R; Sun, Heather H; Gascoyne, Randy D; Pinkus, Geraldine S; van Hummelen, Paul; Wulf, Gerald G; Aster, Jon C; Weinstock, David M; Monti, Stefano; Rodig, Scott J; Wang, Yuzhuo; Shipp, Margaret A

2016-05-05

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease defined by transcriptional classifications, specific signaling and survival pathways, and multiple low-frequency genetic alterations. Preclinical model systems that capture the genetic and functional heterogeneity of DLBCL are urgently needed. Here, we generated and characterized a panel of large B-cell lymphoma (LBCL) patient-derived xenograft (PDX) models, including 8 that reflect the immunophenotypic, transcriptional, genetic, and functional heterogeneity of primary DLBCL and 1 that is a plasmablastic lymphoma. All LBCL PDX models were subjected to whole-transcriptome sequencing to classify cell of origin and consensus clustering classification (CCC) subtypes. Mutations and chromosomal rearrangements were evaluated by whole-exome sequencing with an extended bait set. Six of the 8 DLBCL models were activated B-cell (ABC)-type tumors that exhibited ABC-associated mutations such as MYD88, CD79B, CARD11, and PIM1. The remaining 2 DLBCL models were germinal B-cell type, with characteristic alterations of GNA13, CREBBP, and EZH2, and chromosomal translocations involving IgH and either BCL2 or MYC Only 25% of the DLBCL PDX models harbored inactivating TP53 mutations, whereas 75% exhibited copy number alterations of TP53 or its upstream modifier, CDKN2A, consistent with the reported incidence and type of p53 pathway alterations in primary DLBCL. By CCC criteria, 6 of 8 DLBCL PDX models were B-cell receptor (BCR)-type tumors that exhibited selective surface immunoglobulin expression and sensitivity to entospletinib, a recently developed spleen tyrosine kinase inhibitor. In summary, we have established and characterized faithful PDX models of DLBCL and demonstrated their usefulness in functional analyses of proximal BCR pathway inhibition. © 2016 by The American Society of Hematology.

DISCOIDIN DOMAIN RECEPTOR TYROSINE KINASES: NEW PLAYERS IN CANCER PROGRESSION

PubMed Central

Valiathan, Rajeshwari R.; Marco, Marta; Leitinger, Birgit; Kleer, Celina G.; Fridman, Rafael

2012-01-01

Almost all human cancers display dysregulated expression and/or function of one or more receptor tyrosine kinases (RTKs). The strong causative association between altered RTK function and cancer progression has translated into novel therapeutic strategies that target these cell surface receptors in the treatment of cancer. Yet, the full spectrum of RTKs that may alter the oncogenic process is not completely understood. Accumulating evidence suggests that a unique set of RTKs known as the Discoidin Domain Receptors (DDRs) play a role in cancer progression by regulating the interactions of tumor cells with their surrounding collagen matrix. The DDRs are the only RTKs that specifically bind to, and are activated by collagen. Hence, the DDRs are part of the signaling networks that translate information from the extracellular matrix thereby acting as key regulators of cell-matrix interactions. Under physiological conditions, DDRs control cell and tissue homeostasis by acting as collagen sensors, transducing signals that regulate cell polarity, tissue morphogenesis, and cell differentiation. In cancer, DDRs are hijacked by tumor cells to disrupt normal cell-matrix communication and initiate pro-migratory and pro-invasive programs. Importantly, several cancer types exhibit DDR mutations, which are thought to alter receptor function and contribute to cancer progression. Other evidence suggests that the actions of DDRs in cancer are complex, either promoting or suppressing tumor cell behavior in a DDR type/isoform specific and context dependent manner. Thus, there is still a considerable gap in our knowledge of DDR actions in cancer tissues. This review summarizes the current knowledge on DDR expression and function in cancer and discusses the potential implications of DDRs in cancer biology. It is hoped that this effort will encourage more research into these poorly understood but unique RTKs, which have the potential of becoming novel therapeutics targets in cancer. PMID:22366781

Prenatal Alcohol Exposure and Cellular Differentiation

PubMed Central

Veazey, Kylee J.; Muller, Daria; Golding, Michael C.

2013-01-01

Exposure to alcohol significantly alters the developmental trajectory of progenitor cells and fundamentally compromises tissue formation (i.e., histogenesis). Emerging research suggests that ethanol can impair mammalian development by interfering with the execution of molecular programs governing differentiation. For example, ethanol exposure disrupts cellular migration, changes cell–cell interactions, and alters growth factor signaling pathways. Additionally, ethanol can alter epigenetic mechanisms controlling gene expression. Normally, lineage-specific regulatory factors (i.e., transcription factors) establish the transcriptional networks of each new cell type; the cell’s identity then is maintained through epigenetic alterations in the way in which the DNA encoding each gene becomes packaged within the chromatin. Ethanol exposure can induce epigenetic changes that do not induce genetic mutations but nonetheless alter the course of fetal development and result in a large array of patterning defects. Two crucial enzyme complexes—the Polycomb and Trithorax proteins—are central to the epigenetic programs controlling the intricate balance between self-renewal and the execution of cellular differentiation, with diametrically opposed functions. Prenatal ethanol exposure may disrupt the functions of these two enzyme complexes, altering a crucial aspect of mammalian differentiation. Characterizing the involvement of Polycomb and Trithorax group complexes in the etiology of fetal alcohol spectrum disorders will undoubtedly enhance understanding of the role that epigenetic programming plays in this complex disorder. PMID:24313167

HIV-1 alters the cytokine microenvironment and effector function of CD8+T cells upon antigen-specific activation with mycobacteria

USDA-ARS?s Scientific Manuscript database

Tuberculosis is the most common opportunistic infection in individuals living with human immunodeficiency virus (HIV). In addition to CD4+ T cell depletion, HIV infection compromises the function of CD8+ T cell-mediated immunity to Mycobacterium tuberculosis (M.tb). These effects on susceptibility ...

Epigenetic Control of Stem Cell Potential During Homeostasis, Aging, and Disease

PubMed Central

Beerman, Isabel; Rossi, Derrick J.

2015-01-01

Stem cell decline is an important cellular driver of aging-associated pathophysiology in multiple tissues. Epigenetic regulation is central to establishing and maintaining stem cell function, and emerging evidence indicates that epigenetic dysregulation contributes to the altered potential of stem cells during aging. Unlike terminally differentiated cells, the impact of epigenetic dysregulation in stem cells is propagated beyond self; alterations can be heritably transmitted to differentiated progeny, in addition to being perpetuated and amplified within the stem cell pool through self-renewal divisions. This review focuses on recent studies examining epigenetic regulation of tissue-specific stem cells in homeostasis, aging, and aging-related disease. PMID:26046761

Intestinal infection with Giardia spp. reduces epithelial barrier function in a myosin light chain kinase-dependent fashion.

PubMed

Scott, Kevin G-E; Meddings, Jonathon B; Kirk, David R; Lees-Miller, Susan P; Buret, André G

2002-10-01

Giardiasis causes malabsorptive diarrhea, and symptoms can be present in the absence of any significant morphologic injury to the intestinal mucosa. The effects of giardiasis on epithelial permeability in vivo remain unknown, and the role of T cells and myosin light chain kinase (MLCK) in altered intestinal barrier function is unclear. This study was conducted to determine whether Giardia spp. alters intestinal permeability in vivo, to assess whether these abnormalities are dependent on T cells, and to assess the role of MLCK in altered epithelial barrier function. Immunocompetent and isogenic athymic mice were inoculated with axenic Giardia muris trophozoites or sterile vehicle (control), then assessed for trophozoite colonization and gastrointestinal permeability. Mechanistic studies using nontransformed human duodenal epithelial monolayers (SCBN) determined the effects of Giardia on myosin light chain (MLC) phosphorylation, transepithelial fluorescein isothiocyanate-dextran fluxes, cytoskeletal F-actin, tight junctional zonula occludens-1 (ZO-1), and MLCK. Giardia infection caused a significant increase in small intestinal, but not gastric or colonic, permeability that correlated with trophozoite colonization in both immunocompetent and athymic mice. In vitro, Giardia increased permeability and phosphorylation of MLC and reorganized F-actin and ZO-1. These alterations were abolished with an MLCK inhibitor. Disruption of small intestinal barrier function is T cell independent, disappears on parasite clearance, and correlates with reorganization of cytoskeletal F-actin and tight junctional ZO-1 in an MLCK-dependent fashion.

Cervical (pre)neoplastic microenvironment promotes the emergence of tolerogenic dendritic cells via RANKL secretion

PubMed Central

Demoulin, Stéphanie A; Somja, Joan; Duray, Anaëlle; Guénin, Samuel; Roncarati, Patrick; Delvenne, Philippe O; Herfs, Michael F; Hubert, Pascale M

2015-01-01

The progression of genital human papillomavirus (HPV) infections into preneoplastic lesions suggests that infected/malignant cells are not adequately recognized by the immune system. In this study, we demonstrated that cervical/vulvar cancer cells secrete factor(s) that affect both the maturation and function of dendritic cells (DC) leading to a tolerogenic profile. Indeed, DC cocultured with cancer cell lines display both a partially mature phenotype after lipopolysaccharide (LPS) maturation and an altered secretory profile (IL-10high and IL-12p70low). In addition, tumor-converted DC acquire the ability to alter T-cell proliferation and to induce FoxP3+ suppressive T cells from naive CD4+ T cells. Among the immunosuppressive factors implicated in DC alterations in genital (pre)neoplastic microenvironment, we identified receptor activator of nuclear factor kappa-B ligand (RANKL), a TNF family member, as a potential candidate. For the first time, we showed that RANKL expression strongly increases during cervical progression. We also confirmed that RANKL is directly secreted by cancer cells and this expression is not related to HPV viral oncoprotein induction. Interestingly, the addition of osteoprotegerin (OPG) in coculture experiments reduces significantly the inhibition of DC maturation, the release of a tolerogenic cytokine profile (IL-12low IL-10high) and the induction of regulatory T (Treg) cells. Our findings suggest that the use of inhibitory molecules directed against RANKL in cervical/vulvar (pre)neoplastic lesions might prevent alterations of DC functionality and represent an attractive strategy to overcome immune tolerance in such cancers. PMID:26155412

PHYSIOLOGY AND ENDOCRINOLOGY SYMPOSIUM:The effects of poor maternal nutrition during gestation on offspring postnatal growth and metabolism.

PubMed

Hoffman, M L; Reed, S A; Pillai, S M; Jones, A K; McFadden, K K; Zinn, S A; Govoni, K E

2017-05-01

Poor maternal nutrition during gestation has been linked to poor growth and development, metabolic dysfunction, impaired health, and reduced productivity of offspring in many species. Poor maternal nutrition can be defined as an excess or restriction of overall nutrients or specific macro- or micronutrients in the diet of the mother during gestation. Interestingly, there are several reports that both restricted- and over-feeding during gestation negatively affect offspring postnatal growth with reduced muscle and bone deposition, increased adipose accumulation, and metabolic dysregulation through reduced leptin and insulin sensitivity. Our laboratory and others have used experimental models of restricted- and over-feeding during gestation to evaluate effects on early postnatal growth of offspring. Restricted- and over-feeding during gestation alters body size, circulating growth factors, and metabolic hormones in offspring postnatally. Both restricted- and over-feeding alter muscle growth, increase lipid content in the muscle, and cause changes in expression of myogenic factors. Although the negative effects of poor maternal nutrition on offspring growth have been well characterized in recent years, the mechanisms contributing to these changes are not well established. Our laboratory has focused on elucidating these mechanisms by evaluating changes in gene and protein expression, and stem cell function. Through RNA-Seq analysis, we observed changes in expression of genes involved in protein synthesis, metabolism, cell function, and signal transduction in muscle tissue. We recently reported that satellite cells, muscle stem cells, have altered expression of myogenic factors in offspring from restricted-fed mothers. Bone marrow derived mesenchymal stem cells, multipotent cells that contribute to development and maintenance of several tissues including bone, muscle, and adipose, have a 50% reduction in cell proliferation and altered metabolism in offspring from both restricted- and over-fed mothers. These findings indicate that poor maternal nutrition may alter offspring postnatal growth by programming stem cell populations. In conclusion, poor maternal nutrition during gestation negatively affects offspring postnatal growth, potentially through impaired stem and satellite cell function. Therefore, determining the mechanisms that contribute to fetal programming is critical to identifying effective management interventions for these offspring and improving efficiency of production.

Epigenetic Regulation of Placenta-Specific 8 Contributes to Altered Function of Endothelial Colony-Forming Cells Exposed to Intrauterine Gestational Diabetes Mellitus.

PubMed

Blue, Emily K; Sheehan, BreAnn M; Nuss, Zia V; Boyle, Frances A; Hocutt, Caleb M; Gohn, Cassandra R; Varberg, Kaela M; McClintick, Jeanette N; Haneline, Laura S

2015-07-01

Intrauterine exposure to gestational diabetes mellitus (GDM) is linked to development of hypertension, obesity, and type 2 diabetes in children. Our previous studies determined that endothelial colony-forming cells (ECFCs) from neonates exposed to GDM exhibit impaired function. The current goals were to identify aberrantly expressed genes that contribute to impaired function of GDM-exposed ECFCs and to evaluate for evidence of altered epigenetic regulation of gene expression. Genome-wide mRNA expression analysis was conducted on ECFCs from control and GDM pregnancies. Candidate genes were validated by quantitative RT-PCR and Western blotting. Bisulfite sequencing evaluated DNA methylation of placenta-specific 8 (PLAC8). Proliferation and senescence assays of ECFCs transfected with siRNA to knockdown PLAC8 were performed to determine functional impact. Thirty-eight genes were differentially expressed between control and GDM-exposed ECFCs. PLAC8 was highly expressed in GDM-exposed ECFCs, and PLAC8 expression correlated with maternal hyperglycemia. Methylation status of 17 CpG sites in PLAC8 negatively correlated with mRNA expression. Knockdown of PLAC8 in GDM-exposed ECFCs improved proliferation and senescence defects. This study provides strong evidence in neonatal endothelial progenitor cells that GDM exposure in utero leads to altered gene expression and DNA methylation, suggesting the possibility of altered epigenetic regulation. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Role of Vascular and Lymphatic Endothelial Cells in Hantavirus Pulmonary Syndrome Suggests Targeted Therapeutic Approaches

PubMed Central

Gorbunova, Elena E.; Dalrymple, Nadine A.; Gavrilovskaya, Irina N.

2013-01-01

Abstract Background Hantaviruses in the Americas cause a highly lethal acute pulmonary edema termed hantavirus pulmonary syndrome (HPS). Hantaviruses nonlytically infect microvascular and lymphatic endothelial cells and cause dramatic changes in barrier functions without disrupting the endothelium. Hantaviruses cause changes in the function of infected endothelial cells that normally regulate fluid barrier functions. The endothelium of arteries, veins, and lymphatic vessels are unique and central to the function of vast pulmonary capillary beds that regulate pulmonary fluid accumulation. Results We have found that HPS-causing hantaviruses alter vascular barrier functions of microvascular and lymphatic endothelial cells by altering receptor and signaling pathway responses that serve to permit fluid tissue influx and clear tissue edema. Infection of the endothelium provides several mechanisms for hantaviruses to cause acute pulmonary edema, as well as potential therapeutic targets for reducing the severity of HPS disease. Conclusions Here we discuss interactions of HPS-causing hantaviruses with the endothelium, roles for unique lymphatic endothelial responses in HPS, and therapeutic targeting of the endothelium as a means of reducing the severity of HPS disease. PMID:24024573

Role of vascular and lymphatic endothelial cells in hantavirus pulmonary syndrome suggests targeted therapeutic approaches.

PubMed

Mackow, Erich R; Gorbunova, Elena E; Dalrymple, Nadine A; Gavrilovskaya, Irina N

2013-09-01

Hantaviruses in the Americas cause a highly lethal acute pulmonary edema termed hantavirus pulmonary syndrome (HPS). Hantaviruses nonlytically infect microvascular and lymphatic endothelial cells and cause dramatic changes in barrier functions without disrupting the endothelium. Hantaviruses cause changes in the function of infected endothelial cells that normally regulate fluid barrier functions. The endothelium of arteries, veins, and lymphatic vessels are unique and central to the function of vast pulmonary capillary beds that regulate pulmonary fluid accumulation. We have found that HPS-causing hantaviruses alter vascular barrier functions of microvascular and lymphatic endothelial cells by altering receptor and signaling pathway responses that serve to permit fluid tissue influx and clear tissue edema. Infection of the endothelium provides several mechanisms for hantaviruses to cause acute pulmonary edema, as well as potential therapeutic targets for reducing the severity of HPS disease. Here we discuss interactions of HPS-causing hantaviruses with the endothelium, roles for unique lymphatic endothelial responses in HPS, and therapeutic targeting of the endothelium as a means of reducing the severity of HPS disease.

Effects of humidified and dry air on corneal endothelial cells during vitreal fluid-air exchange.

PubMed

Cekiç, Osman; Ohji, Masahito; Hayashi, Atsushi; Fang, Xiao Y; Kusaka, Shunji; Tano, Yasuo

2002-07-01

To report the immediate anatomic and functional alterations in corneal endothelial cells following use of humidified air and dry air during vitreal fluid-air exchange in rabbits. Experimental study. Rabbits undergoing pars plana vitrectomy and lensectomy were perfused with either dry or humidified air during fluid-air exchange for designated durations. Three different experiments were performed. First, control and experimental corneas were examined by scanning electron microscopy (SEM). Second, corneas were stained with Phalloidin-FITC and examined by fluorescein microscopy. Finally, third, transendothelial permeability for carboxyfluorescein was determined using a diffusion chamber. While different from the corneal endothelial cells, those cells exposed to humidified air were less stressed than cells exposed to dry air by SEM. Actin cytoskeleton was found highly disorganized with dry air exposure. Humidified air maintained the normal actin cytoskeleton throughout the 20 minutes of fluid-air exchange. Paracellular carboxyfluorescein leakage was significantly higher in dry air insufflated eyes compared with that of the humidified air after 5, 10, and 20 minutes of fluid-air exchange (P =.002, P =.004, and P =.002, respectively). Dry air stress during fluid-air exchange causes significant immediate alterations in monolayer appearance, actin cytoskeleton, and barrier function of corneal endothelium in aphakic rabbit eyes. Use of humidified air largely prevents the alterations in monolayer appearance, actin cytoskeleton, and barrier function of corneal endothelial cells.

SLAP deficiency enhances number and function of regulatory T cells preventing chronic autoimmune arthritis in SKG mice.

PubMed

Peterson, Lisa K; Shaw, Laura A; Joetham, Anthony; Sakaguchi, Shimon; Gelfand, Erwin W; Dragone, Leonard L

2011-02-15

To test if manipulating TCR complex-mediated signaling (TCR signaling) could treat autoimmune disease, we generated the double SKG Src-like adapter protein (SLAP) knockout (DSSKO) mouse model. The SKG mutation in ZAP70 and SLAP have opposing functions on the regulation of TCR signaling. The combination of these two mutations alters TCR signaling in the context of a defined genetic background, uniform environmental conditions, and a well-characterized signaling disruption. In contrast to SKG mice, DSSKO mice do not develop zymosan-induced chronic autoimmune arthritis. This arthritis prevention is not due to significant alterations in thymocyte development or repertoire selection but instead enhanced numbers of regulatory T cells (Tregs) and decreased numbers of Th17 cells skewing the ratio of Tregs to autoreactive effector T cells. Treg depletion and/or functional blockade led to the development of arthritis in DSSKO mice. In vitro suppression of effector T cell proliferation was also enhanced, demonstrating that DSSKO mice have increased numbers of Tregs with increased function. Understanding how TCR signals influence development, expansion, and function of Tregs in DSSKO mice could advance our ability to manipulate Treg biology to treat ultimately autoimmune disease.

SLAP Deficiency Enhances Number and Function of Regulatory T Cells Preventing Chronic Autoimmune Arthritis in SKG Mice

PubMed Central

Peterson, Lisa K.; Shaw, Laura A.; Joetham, Anthony; Sakaguchi, Shimon; Gelfand, Erwin W.; Dragone, Leonard L.

2011-01-01

To test if manipulating TCR complex-mediated signaling (TCR signaling) could treat autoimmune disease, we generated the double SKG Src-like adapter protein (SLAP) knockout (DSSKO) mouse model. The SKG mutation in ZAP70 and SLAP have opposing functions on the regulation of TCR signaling. The combination of these two mutations alters TCR signaling in the context of a defined genetic background, uniform environmental conditions, and a well-characterized signaling disruption. In contrast to SKG mice, DSSKO mice do not develop zymosan-induced chronic autoimmune arthritis. This arthritis prevention is not due to significant alterations in thymocyte development or repertoire selection but instead enhanced numbers of regulatory T cells (Tregs) and decreased numbers of Th17 cells skewing the ratio of Tregs to autoreactive effector T cells. Treg depletion and/or functional blockade led to the development of arthritis in DSSKO mice. In vitro suppression of effector T cell proliferation was also enhanced, demonstrating that DSSKO mice have increased numbers of Tregs with increased function. Understanding how TCR signals influence development, expansion, and function of Tregs in DSSKO mice could advance our ability to manipulate Treg biology to treat ultimately autoimmune disease. PMID:21248251

Mechanisms of β-cell functional adaptation to changes in workload

PubMed Central

Wortham, Matthew; Sander, Maike

2016-01-01

Insulin secretion must be tightly coupled to nutritional state to maintain blood glucose homeostasis. To this end, pancreatic β-cells sense and respond to changes in metabolic conditions, thereby anticipating insulin demands for a given physiological context. This is achieved in part through adjustments of nutrient metabolism, which is controlled at several levels including allosteric regulation, posttranslational modifications, and altered expression of metabolic enzymes. In this review, we discuss mechanisms of β-cell metabolic and functional adaptation in the context of two physiological states that alter glucose-stimulated insulin secretion: fasting and insulin resistance. We review current knowledge of metabolic changes that occur in the β-cell during adaptation and specifically discuss transcriptional mechanisms that underlie β-cell adaptation. A more comprehensive understanding of how β-cells adapt to changes in nutrient state could identify mechanisms to be co-opted for therapeutically modulating insulin secretion in metabolic disease. PMID:27615135

Adaptor Protein-1 Complex Affects the Endocytic Trafficking and Function of Peptidylglycine α-Amidating Monooxygenase, a Luminal Cuproenzyme*

PubMed Central

Bonnemaison, Mathilde L.; Bäck, Nils; Duffy, Megan E.; Ralle, Martina; Mains, Richard E.; Eipper, Betty A.

2015-01-01

The adaptor protein-1 complex (AP-1), which transports cargo between the trans-Golgi network and endosomes, plays a role in the trafficking of Atp7a, a copper-transporting P-type ATPase, and peptidylglycine α-amidating monooxygenase (PAM), a copper-dependent membrane enzyme. Lack of any of the four AP-1 subunits impairs function, and patients with MEDNIK syndrome, a rare genetic disorder caused by lack of expression of the σ1A subunit, exhibit clinical and biochemical signs of impaired copper homeostasis. To explore the role of AP-1 in copper homeostasis in neuroendocrine cells, we used corticotrope tumor cells in which AP-1 function was diminished by reducing expression of its μ1A subunit. Copper levels were unchanged when AP-1 function was impaired, but cellular levels of Atp7a declined slightly. The ability of PAM to function was assessed by monitoring 18-kDa fragment-NH2 production from proopiomelanocortin. Reduced AP-1 function made 18-kDa fragment amidation more sensitive to inhibition by bathocuproine disulfonate, a cell-impermeant Cu(I) chelator. The endocytic trafficking of PAM was altered, and PAM-1 accumulated on the cell surface when AP-1 levels were reduced. Reduced AP-1 function increased the Atp7a presence in early/recycling endosomes but did not alter the ability of copper to stimulate its appearance on the plasma membrane. Co-immunoprecipitation of a small fraction of PAM and Atp7a supports the suggestion that copper can be transferred directly from Atp7a to PAM, a process that can occur only when both proteins are present in the same subcellular compartment. Altered luminal cuproenzyme function may contribute to deficits observed when the AP-1 function is compromised. PMID:26170456

PRESENILIN-NULL CELLS HAVE ALTERED TWO-PORE CALCIUM CHANNEL EXPRESSION AND LYSOSOMAL CALCIUM; IMPLICATIONS FOR LYSOSOMAL FUNCTION

PubMed Central

Kayala, Kara M Neely; Dickinson, George D; Minassian, Anet; Walls, Ken C; Green, Kim N; LaFerla, Frank M

2012-01-01

Presenilins are necessary for calcium homeostasis and also for efficient proteolysis through the autophagy/lysosome system. Presenilin regulates both endoplasmic reticulum calcium stores and autophagic proteolysis in a γ-secretase independent fashion. The endo-lysosome system can also act as a calcium store, with calcium efflux channels being recently identified as two-pore channels 1 and 2. Here we investigated lysosomal calcium content and the channels that mediate calcium release from these acidic stores in presenilin knockout cells. We report that presenilin loss leads to a lower total lysosomal calcium store despite the buildup of lysosomes found in these cells. Additionally, we find alterations in two-pore calcium channel protein expression, with loss of presenilin preventing the formation of a high molecular weight species of TPC1 and TPC2. Finally, we find that treatments that disturb lysosomal calcium release lead to a reduction in autophagy function yet lysosomal inhibitors do not alter two-pore calcium channel expression. These data indicate that alterations in lysosomal calcium in the absence of presenilins might be leading to disruptions in autophagy. PMID:23103503

Systems-wide RNAi analysis of CASP8AP2/FLASH shows transcriptional deregulation of the replication-dependent histone genes and extensive effects on the transcriptome of colorectal cancer cells

PubMed Central

2012-01-01

Background Colorectal carcinomas (CRC) carry massive genetic and transcriptional alterations that influence multiple cellular pathways. The study of proteins whose loss-of-function (LOF) alters the growth of CRC cells can be used to further understand the cellular processes cancer cells depend upon for survival. Results A small-scale RNAi screen of ~400 genes conducted in SW480 CRC cells identified several candidate genes as required for the viability of CRC cells, most prominently CASP8AP2/FLASH. To understand the function of this gene in maintaining the viability of CRC cells in an unbiased manner, we generated gene specific expression profiles following RNAi. Silencing of CASP8AP2/FLASH resulted in altered expression of over 2500 genes enriched for genes associated with cellular growth and proliferation. Loss of CASP8AP2/FLASH function was significantly associated with altered transcription of the genes encoding the replication-dependent histone proteins as a result of the expression of the non-canonical polyA variants of these transcripts. Silencing of CASP8AP2/FLASH also mediated enrichment of changes in the expression of targets of the NFκB and MYC transcription factors. These findings were confirmed by whole transcriptome analysis of CASP8AP2/FLASH silenced cells at multiple time points. Finally, we identified and validated that CASP8AP2/FLASH LOF increases the expression of neurofilament heavy polypeptide (NEFH), a protein recently linked to regulation of the AKT1/ß-catenin pathway. Conclusions We have used unbiased RNAi based approaches to identify and characterize the function of CASP8AP2/FLASH, a protein not previously reported as required for cell survival. This study further defines the role CASP8AP2/FLASH plays in the regulating expression of the replication-dependent histones and shows that its LOF results in broad and reproducible effects on the transcriptome of colorectal cancer cells including the induction of expression of the recently described tumor suppressor gene NEFH. PMID:22216762

Systems-wide RNAi analysis of CASP8AP2/FLASH shows transcriptional deregulation of the replication-dependent histone genes and extensive effects on the transcriptome of colorectal cancer cells.

PubMed

Hummon, Amanda B; Pitt, Jason J; Camps, Jordi; Emons, Georg; Skube, Susan B; Huppi, Konrad; Jones, Tamara L; Beissbarth, Tim; Kramer, Frank; Grade, Marian; Difilippantonio, Michael J; Ried, Thomas; Caplen, Natasha J

2012-01-04

Colorectal carcinomas (CRC) carry massive genetic and transcriptional alterations that influence multiple cellular pathways. The study of proteins whose loss-of-function (LOF) alters the growth of CRC cells can be used to further understand the cellular processes cancer cells depend upon for survival. A small-scale RNAi screen of ~400 genes conducted in SW480 CRC cells identified several candidate genes as required for the viability of CRC cells, most prominently CASP8AP2/FLASH. To understand the function of this gene in maintaining the viability of CRC cells in an unbiased manner, we generated gene specific expression profiles following RNAi. Silencing of CASP8AP2/FLASH resulted in altered expression of over 2500 genes enriched for genes associated with cellular growth and proliferation. Loss of CASP8AP2/FLASH function was significantly associated with altered transcription of the genes encoding the replication-dependent histone proteins as a result of the expression of the non-canonical polyA variants of these transcripts. Silencing of CASP8AP2/FLASH also mediated enrichment of changes in the expression of targets of the NFκB and MYC transcription factors. These findings were confirmed by whole transcriptome analysis of CASP8AP2/FLASH silenced cells at multiple time points. Finally, we identified and validated that CASP8AP2/FLASH LOF increases the expression of neurofilament heavy polypeptide (NEFH), a protein recently linked to regulation of the AKT1/ß-catenin pathway. We have used unbiased RNAi based approaches to identify and characterize the function of CASP8AP2/FLASH, a protein not previously reported as required for cell survival. This study further defines the role CASP8AP2/FLASH plays in the regulating expression of the replication-dependent histones and shows that its LOF results in broad and reproducible effects on the transcriptome of colorectal cancer cells including the induction of expression of the recently described tumor suppressor gene NEFH.

Impact of genomic damage and ageing on stem cell function

PubMed Central

Behrens, Axel; van Deursen, Jan M.; Rudolph, K. Lenhard; Schumacher, Björn

2014-01-01

Impairment of stem cell function contributes to the progressive deterioration of tissue maintenance and repair with ageing. Evidence is mounting that age-dependent accumulation of DNA damage in both stem cells and cells that comprise the stem cell microenvironment are partly responsible for stem cell dysfunction with ageing. Here, we review the impact of the various types of DNA damage that accumulate with ageing on stem cell functionality, as well as the development of cancer. We discuss DNA-damage-induced cell intrinsic and extrinsic alterations that influence these processes, and review recent advances in understanding systemic adjustments to DNA damage and how they affect stem cells. PMID:24576896

The Role of Oligosaccharides in Host-Microbial Interactions for Human Health.

PubMed

Ross, Sarah A; Lane, Jonathan A; Marotta, Mariarosaria; Kavanaugh, Devon; Ryan, Joseph Thomas; Joshi, Lokesh; Hickey, Rita M

Milk oligosaccharides have many associated bioactivities which can contribute to human health and offer protective properties to the host. Such bioactivities include anti-infective properties whereby oligosaccharides interact with bacterial cells and prevent adhesion to the host and subsequent colonization. Milk oligosaccharides have also been shown to alter the glycosylation of intestinal cells, leading to a reduction in pathogenic colonization. In addition, these sugars promote adhesion of commensal bacterial strains to host cells as well as possessing the ability to alter mucin expression in intestinal cells and improve barrier function. The ability of milk oligosaccharides to alter the transcriptome of both commensal bacterial strains and intestinal epithelial cells has also been revealed, indicating the potential of many cell types to detect the presence of milk oligosaccharides and respond accordingly at the genetic level. Interestingly, domestic animal milk may provide a bioactive source of oligosaccharides for formula supplementation with the aim of emulating the gold standard that is human milk. Overall, this review highlights the ability of milk oligosaccharides to promote health in a variety of ways, for example, through direct bacterial interactions, immunomodulatory activities, promotion of gut barrier function, and induction of protective transcriptional responses.

Complete depletion of primordial germ cells in an All-female fish leads to Sex-biased gene expression alteration and sterile All-male occurrence.

PubMed

Liu, Wei; Li, Shi-Zhu; Li, Zhi; Wang, Yang; Li, Xi-Yin; Zhong, Jian-Xiang; Zhang, Xiao-Juan; Zhang, Jun; Zhou, Li; Gui, Jian-Fang

2015-11-18

Gynogenesis is one of unisexual reproduction modes in vertebrates, and produces all-female individuals with identical genetic background. In sexual reproduction vertebrates, the roles of primordial germ cells on sexual dimorphism and gonadal differentiation have been largely studied, and two distinct functional models have been proposed. However, the role of primordial germ cells remains unknown in unisexual animals, and it is also unclear whether the functional models in sexual reproduction animals are common in unisexual animals. To solve these puzzles, we attempt to utilize the gynogenetic superiority of polyploid Carassius gibelio to create a complete germ cell-depleted gonad model by a similar morpholino-mediated knockdown approach used in other examined sexual reproduction fishes. Through the germ cell-depleted gonad model, we have performed comprehensive and comparative transcriptome analysis, and revealed a complete alteration of sex-biased gene expression. Moreover, the expression alteration leads to up-regulation of testis-biased genes and down-regulation of ovary-biased genes, and results in the occurrence of sterile all-males with testis-like gonads and secondary sex characteristics in the germ cell-depleted gynogenetic Carassius gibelio. Our current results have demonstrated that unisexual gynogenetic embryos remain keeping male sex determination information in the genome, and the complete depletion of primordial germ cells in the all-female fish leads to sex-biased gene expression alteration and sterile all-male occurrence.

Alteration of estrogen-regulated gene expression in human cells induced by the agricultural and horticultural herbicide glyphosate.

PubMed

Hokanson, R; Fudge, R; Chowdhary, R; Busbee, D

2007-09-01

Gene expression is altered in mammalian cells (MCF-7 cells), by exposure to a variety of chemicals that mimic steroid hormones or interact with endocrine receptors or their co-factors. Among those populations chronically exposed to these endocrine disruptive chemicals are persons, and their families, who are employed in agriculture or horticulture, or who use agricultural/horticultural chemicals. Among the chemicals most commonly used, both commercially and in the home, is the herbicide glyphosate. Although glyphosate is commonly considered to be relatively non-toxic, we utilized in vitro DNA microarray analysis of this chemical to evaluate its capacity to alter the expression of a variety of genes in human cells. We selected a group of genes, determined by DNA microarray analysis to be dysregulated, and used quantitative real-time PCR to corroborate their altered states of expression. We discussed the reported function of those genes, with emphasis on altered physiological states that are capable of initiating adverse health effects that might be anticipated if gene expression were significantly altered in either adults or embryos exposed in utero.

Rapid assays for lectin toxicity and binding changes that reflect altered glycosylation in mammalian cells.

PubMed

Stanley, Pamela; Sundaram, Subha

2014-06-03

Glycosylation engineering is used to generate glycoproteins, glycolipids, or proteoglycans with a more defined complement of glycans on their glycoconjugates. For example, a mammalian cell glycosylation mutant lacking a specific glycosyltransferase generates glycoproteins, and/or glycolipids, and/or proteoglycans with truncated glycans missing the sugar transferred by that glycosyltransferase, as well as those sugars that would be added subsequently. In some cases, an alternative glycosyltransferase may then use the truncated glycans as acceptors, thereby generating a new or different glycan subset in the mutant cell. Another type of glycosylation mutant arises from gain-of-function mutations that, for example, activate a silent glycosyltransferase gene. In this case, glycoconjugates will have glycans with additional sugar(s) that are more elaborate than the glycans of wild type cells. Mutations in other genes that affect glycosylation, such as nucleotide sugar synthases or transporters, will alter the glycan complement in more general ways that usually affect several types of glycoconjugates. There are now many strategies for generating a precise mutation in a glycosylation gene in a mammalian cell. Large-volume cultures of mammalian cells may also generate spontaneous mutants in glycosylation pathways. This article will focus on how to rapidly characterize mammalian cells with an altered glycosylation activity. The key reagents for the protocols described are plant lectins that bind mammalian glycans with varying avidities, depending on the specific structure of those glycans. Cells with altered glycosylation generally become resistant or hypersensitive to lectin toxicity, and have reduced or increased lectin or antibody binding. Here we describe rapid assays to compare the cytotoxicity of lectins in a lectin resistance test, and the binding of lectins or antibodies by flow cytometry in a glycan-binding assay. Based on these tests, glycosylation changes expressed by a cell can be revealed, and glycosylation mutants classified into phenotypic groups that may reflect a loss-of-function or gain-of-function mutation in a specific gene involved in glycan synthesis. Copyright © 2014 John Wiley & Sons, Inc.

Fyn kinase genetic ablation causes structural abnormalities in mature retina and defective Müller cell function.

PubMed

Chavez-Solano, Marbella; Ibarra-Sanchez, Alfredo; Treviño, Mario; Gonzalez-Espinosa, Claudia; Lamas, Monica

2016-04-01

Fyn kinase is widely expressed in neuronal and glial cells of the brain, where it exerts multiple functional roles that affect fundamental physiological processes. The aim of our study was to investigate the, so far unknown, functional role of Fyn in the retina. We report that Fyn is expressed, in vivo, in a subpopulation of Müller glia. We used a mouse model of Fyn genetic ablation and Müller-enriched primary cultures to demonstrate that Fyn deficiency induces morphological alterations in the mature retina, a reduction in the thickness of the outer and inner nuclear layers and alterations in postnatal Müller cell physiology. These include shortening of Müller cell processes, a decrease in cell proliferation, inactivation of the Akt signal transduction pathway, a reduced number of focal adhesions points and decreased adhesion of these cells to the ECM. As abnormalities in Müller cell physiology have been previously associated to a compromised retinal function we evaluated behavioral responses to visual stimulation. Our results associate Fyn deficiency with impaired visual optokinetic responses under scotopic and photopic light conditions. Our study reveals novel roles for Fyn kinase in retinal morphology and Müller cell physiology and suggests that Fyn is required for optimal visual processing. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of Modeled Microgravity on Expression Profiles of Micro RNA in Human Lymphoblastoid Cells

NASA Technical Reports Server (NTRS)

Mangala, Lingegowda S.; Emami, Kamal; Story, Michael; Ramesh, Govindarajan; Rohde, Larry; Wu, Honglu

2010-01-01

Among space radiation and other environmental factors, microgravity or an altered gravity is undoubtedly the most significant stress experienced by living organisms during flight. In comparison to the static 1g, microgravity has been shown to alter global gene expression patterns and protein levels in cultured cells or animals. Micro RNA (miRNA) has recently emerged as an important regulator of gene expression, possibly regulating as many as one-third of all human genes. miRNA represents a class of single-stranded noncoding regulatory RNA molecules ( 22 nt) that control gene expressions by inhibiting the translation of mRNA to proteins. However, very little is known on the effect of altered gravity on miRNA expression. We hypothesized that the miRNA expression profile will be altered in zero gravity resulting in regulation of the gene expression and functional changes of the cells. To test this hypothesis, we cultured TK6 human lymphoblastoid cells in Synthecon s Rotary cell culture system (bioreactors) for 72 h either in the rotating (10 rpm) to model the microgravity in space or in the static condition. The cell viability was determined before and after culturing the cells in the bioreactor using both trypan blue and guava via count. Expressions of a panel of 352 human miRNA were analyzed using the miRNA PCRarray. Out of 352 miRNAs, expressions of 75 were significantly altered by a change of greater than 1.5 folds and seven miRNAs were altered by a fold change greater than 2 under the rotating culture condition. Among these seven, miR-545 and miR-517a were down regulated by 2 folds, whereas miR-150, miR-302a, miR-139-3p, miR-515-3p and miR-564 were up regulated by 2 to 8 folds. To confirm whether this altered miRNA expression correlates with gene expression and functional changes of the cells, we performed DNA Illumina Microarray Analysis and validated the related genes using q-RT PCR.

Canine and Equine Mesenchymal Stem Cells Grown in Serum Free Media Have Altered Immunophenotype.

PubMed

Clark, Kaitlin C; Kol, Amir; Shahbenderian, Salpi; Granick, Jennifer L; Walker, Naomi J; Borjesson, Dori L

2016-04-01

Mesenchymal stem cell (MSC) therapy is being increasingly used to treat dogs and horses with naturally-occurring diseases. However these animals also serve as critical large animal models for ongoing translation of cell therapy products to the human market. MSC manufacture for clinical use mandates improvement in cell culture systems to meet demands for higher MSC numbers and removal of xeno-proteins (i.e. fetal bovine serum, FBS). While serum-free media (SFM) is commercially available, its affects on MSC phenotype and immunomodulatory functions are not fully known. The objective of this study was to determine if specific MSC culture conditions, MSC expansion in HYPERFlasks® or MSC expansion in a commercially available SFM, would alter MSC proliferation, phenotype or immunomodulatory properties in vitro. MSCs cultured in HYPERFlasks® were similar in phenotype, proliferative capacity and immunomodulatory functions to MSCs grown in standard flasks however MSC yield was markedly increased. HYPERFlasks® therefore provide a viable option to generate greater cell numbers in a streamlined manner. Canine and equine MSCs expanded in SFM displayed similar proliferation, surface phenotype and inhibitory effect on lymphocyte proliferation in vitro. However, MSCs cultured in the absence of FBS secreted significantly less PGE2, and were significantly less able to inhibit IFNγ secretion by activated T-cells. Immunomodulatory functions altered by expansion in SFM were species dependent. Unlike equine MSCs, in canine adipose-derived MSCs, the inhibition of lymphocyte proliferation was not principally modulated by PGE2. The removal of FBS from both canine and equine MSC culture systems resulted in altered immunomodulatory properties in vitro and warrants further investigation prior to moving towards FBS-free culture conditions.

Metaproteomics of Colonic Microbiota Unveils Discrete Protein Functions among Colitic Mice and Control Groups.

PubMed

Moon, Clara; Stupp, Gregory S; Su, Andrew I; Wolan, Dennis W

2018-02-01

Metaproteomics can greatly assist established high-throughput sequencing methodologies to provide systems biological insights into the alterations of microbial protein functionalities correlated with disease-associated dysbiosis of the intestinal microbiota. Here, the authors utilize the well-characterized murine T cell transfer model of colitis to find specific changes within the intestinal luminal proteome associated with inflammation. MS proteomic analysis of colonic samples permitted the identification of ≈10 000-12 000 unique peptides that corresponded to 5610 protein clusters identified across three groups, including the colitic Rag1 -/- T cell recipients, isogenic Rag1 -/- controls, and wild-type mice. The authors demonstrate that the colitic mice exhibited a significant increase in Proteobacteria and Verrucomicrobia and show that such alterations in the microbial communities contributed to the enrichment of specific proteins with transcription and translation gene ontology terms. In combination with 16S sequencing, the authors' metaproteomics-based microbiome studies provide a foundation for assessing alterations in intestinal luminal protein functionalities in a robust and well-characterized mouse model of colitis, and set the stage for future studies to further explore the functional mechanisms of altered protein functionalities associated with dysbiosis and inflammation. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Deleterious effects of tributyltin on porcine vascular stem cells physiology.

PubMed

Bernardini, Chiara; Zannoni, Augusta; Bertocchi, Martina; Bianchi, Francesca; Salaroli, Roberta; Botelho, Giuliana; Bacci, Maria Laura; Ventrella, Vittoria; Forni, Monica

2016-01-01

The vascular functional and structural integrity is essential for the maintenance of the whole organism and it has been demonstrated that different types of vascular progenitor cells resident in the vessel wall play an important role in this process. The purpose of the present research was to observe the effect of tributyltin (TBT), a risk factor for vascular disorders, on porcine Aortic Vascular Precursor Cells (pAVPCs) in term of cytotoxicity, gene expression profile, functionality and differentiation potential. We have demonstrated that pAVPCs morphology deeply changed following TBT treatment. After 48h a cytotoxic effect has been detected and Annexin binding assay demonstrated that TBT induced apoptosis. The transcriptional profile of characteristic pericyte markers has been altered: TBT 10nM substantially induced alpha-SMA, while, TBT 500nM determined a significant reduction of all pericyte markers. IL-6 protein detected in the medium of pAVPCs treated with TBT at both doses studied and with a dose response. TBT has interfered with normal pAVPC functionality preventing their ability to support a capillary-like network. In addition TBT has determined an increase of pAVPC adipogenic differentiation. In conclusion in the present paper we have demonstrated that TBT alters the vascular stem cells in terms of structure, functionality and differentiating capability, therefore effects of TBT in blood should be deeply explored to understand the potential vascular risk associated with the alteration of vascular stem cell physiology. Copyright © 2016 Elsevier Inc. All rights reserved.

Feline immunodeficiency virus OrfA alters gene expression of splicing factors and proteasome-ubiquitination proteins

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

Sundstrom, Magnus; Chatterji, Udayan; Schaffer, Lana

2008-02-20

Expression of the feline immunodeficiency virus (FIV) accessory protein OrfA (or Orf2) is critical for efficient viral replication in lymphocytes, both in vitro and in vivo. OrfA has been reported to exhibit functions in common with the human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) accessory proteins Vpr and Tat, although the function of OrfA has not been fully explained. Here, we use microarray analysis to characterize how OrfA modulates the gene expression profile of T-lymphocytes. The primary IL-2-dependent T-cell line 104-C1 was transduced to express OrfA. Functional expression of OrfA was demonstrated by trans complementation of the OrfA-defectivemore » clone, FIV-34TF10. OrfA-expressing cells had a slightly reduced cell proliferation rate but did not exhibit any significant alteration in cell cycle distribution. Reverse-transcribed RNA from cells expressing green fluorescent protein (GFP) or GFP + OrfA were hybridized to Affymetrix HU133 Plus 2.0 microarray chips representing more than 47,000 genome-wide transcripts. By using two statistical approaches, 461 (Rank Products) and 277 (ANOVA) genes were identified as modulated by OrfA expression. The functional relevance of the differentially expressed genes was explored by Ingenuity Pathway Analysis. The analyses revealed alterations in genes critical for RNA post-transcriptional modifications and protein ubiquitination as the two most significant functional outcomes of OrfA expression. In these two groups, several subunits of the spliceosome, cellular splicing factors and family members of the proteasome-ubiquitination system were identified. These findings provide novel information on the versatile function of OrfA during FIV infection and indicate a fine-tuning mechanism of the cellular environment by OrfA to facilitate efficient FIV replication.« less

A Hypergravity Environment Induced by Centrifugation Alters Plant Cell Proliferation and Growth in an Opposite Way to Microgravity

NASA Astrophysics Data System (ADS)

Manzano, Ana I.; Herranz, Raúl; van Loon, Jack J. W. A.; Medina, F. Javier

2012-12-01

Seeds of Arabidopsis thaliana were exposed to hypergravity environments (2 g and 6 g) and germinated during centrifugation. Seedlings grew for 2 and 4 days before fixation. In all cases, comparisons were performed against an internal (subjected to rotational vibrations and other factors of the machine) and an external control at 1 g. On seedlings grown in hypergravity the total length and the root length were measured. The cortical root meristematic cells were analyzed to investigate the alterations in cell proliferation, which were quantified by counting the number of cells per millimeter in the specific cell files, and cell growth, which were appraised through the rate of ribosome biogenesis, assessed by morphological and morphometrical parameters of the nucleolus. The expression of cyclin B1, a key regulator of entry in mitosis, was assessed by the use of a CYCB1:GUS genetic construction. The results showed significant differences in some of these parameters when comparing the 1 g internal rotational control with the 1 g external control, indicating that the machine by itself was a source of alterations. When the effect of hypergravity was isolated from other environmental factors, by comparing the experimental conditions with the rotational control, cell proliferation appeared depleted, cell growth was increased and there was an enhanced expression of cyclin B1. The functional meaning of these effects is that cell proliferation and cell growth, which are strictly associated functions under normal 1 g ground conditions, are uncoupled under hypergravity. This uncoupling was also described by us in previous experiments as an effect of microgravity, but in an opposite way. Furthermore, root meristems appear thicker in hypergravity-treated than in control samples, which can be related to changes in the cell wall induced by altered gravity.

Stomatal Function Requires Pectin De-methyl-esterification of the Guard Cell Wall

DOE PAGES

Amsbury, Sam; Hunt, Lee; Elhaddad, Nagat; ...

2016-10-06

Stomatal opening and closure depends on changes in turgor pressure acting within guard cells to alter cell shape. The extent of these shape changes is limited by the mechanical properties of the cells, which will be largely dependent on the structure of the cell walls. Although it has long been observed that guard cells are anisotropic due to differential thickening and the orientation of cellulose microfibrils, our understanding of the composition of the cell wall that allows them to undergo repeated swelling and deflation remains surprisingly poor. Here, we show that the walls of guard cells are rich in un-esterified pectins.more » We identify a pectin methylesterase gene, PME6, which is highly expressed in guard cells and required for stomatal function. pme6-1 mutant guard cells have walls enriched in methyl-esterified pectin and show a decreased dynamic range in response to triggers of stomatal opening/closure, including elevated osmoticum, suggesting that abrogation of stomatal function reflects a mechanical change in the guard cell wall. Altered stomatal function leads to increased conductance and evaporative cooling, as well as decreased plant growth. The growth defect of the  pme6-1 mutant is rescued by maintaining the plants in elevated CO 2, substantiating gas exchange analyses, indicating that the mutant stomata can bestow an improved assimilation rate. Restoration of PME6 rescues guard cell wall pectin methyl-esterification status, stomatal function, and plant growth. Our results establish a link between gene expression in guard cells and their cell wall properties, with a corresponding effect on stomatal function and plant physiology.« less

Stomatal Function Requires Pectin De-methyl-esterification of the Guard Cell Wall

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

Amsbury, Sam; Hunt, Lee; Elhaddad, Nagat

Stomatal opening and closure depends on changes in turgor pressure acting within guard cells to alter cell shape. The extent of these shape changes is limited by the mechanical properties of the cells, which will be largely dependent on the structure of the cell walls. Although it has long been observed that guard cells are anisotropic due to differential thickening and the orientation of cellulose microfibrils, our understanding of the composition of the cell wall that allows them to undergo repeated swelling and deflation remains surprisingly poor. Here, we show that the walls of guard cells are rich in un-esterified pectins.more » We identify a pectin methylesterase gene, PME6, which is highly expressed in guard cells and required for stomatal function. pme6-1 mutant guard cells have walls enriched in methyl-esterified pectin and show a decreased dynamic range in response to triggers of stomatal opening/closure, including elevated osmoticum, suggesting that abrogation of stomatal function reflects a mechanical change in the guard cell wall. Altered stomatal function leads to increased conductance and evaporative cooling, as well as decreased plant growth. The growth defect of the  pme6-1 mutant is rescued by maintaining the plants in elevated CO 2, substantiating gas exchange analyses, indicating that the mutant stomata can bestow an improved assimilation rate. Restoration of PME6 rescues guard cell wall pectin methyl-esterification status, stomatal function, and plant growth. Our results establish a link between gene expression in guard cells and their cell wall properties, with a corresponding effect on stomatal function and plant physiology.« less

Stomatal Function Requires Pectin De-methyl-esterification of the Guard Cell Wall.

PubMed

Amsbury, Sam; Hunt, Lee; Elhaddad, Nagat; Baillie, Alice; Lundgren, Marjorie; Verhertbruggen, Yves; Scheller, Henrik V; Knox, J Paul; Fleming, Andrew J; Gray, Julie E

2016-11-07

Stomatal opening and closure depends on changes in turgor pressure acting within guard cells to alter cell shape [1]. The extent of these shape changes is limited by the mechanical properties of the cells, which will be largely dependent on the structure of the cell walls. Although it has long been observed that guard cells are anisotropic due to differential thickening and the orientation of cellulose microfibrils [2], our understanding of the composition of the cell wall that allows them to undergo repeated swelling and deflation remains surprisingly poor. Here, we show that the walls of guard cells are rich in un-esterified pectins. We identify a pectin methylesterase gene, PME6, which is highly expressed in guard cells and required for stomatal function. pme6-1 mutant guard cells have walls enriched in methyl-esterified pectin and show a decreased dynamic range in response to triggers of stomatal opening/closure, including elevated osmoticum, suggesting that abrogation of stomatal function reflects a mechanical change in the guard cell wall. Altered stomatal function leads to increased conductance and evaporative cooling, as well as decreased plant growth. The growth defect of the pme6-1 mutant is rescued by maintaining the plants in elevated CO 2 , substantiating gas exchange analyses, indicating that the mutant stomata can bestow an improved assimilation rate. Restoration of PME6 rescues guard cell wall pectin methyl-esterification status, stomatal function, and plant growth. Our results establish a link between gene expression in guard cells and their cell wall properties, with a corresponding effect on stomatal function and plant physiology. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Deficiency in Aryl Hydrocarbon Receptor (AHR) Expression throughout Aging Alters Gene Expression Profiles in Murine Long-Term Hematopoietic Stem Cells

PubMed Central

Bennett, John A.; Singh, Kameshwar P.; Unnisa, Zeenath; Welle, Stephen L.; Gasiewicz, Thomas A.

2015-01-01

Dysregulation of hematopoietic stem cell (HSC) signaling can contribute to the development of diseases of the blood system. Lack of aryl hydrocarbon receptor (AhR) has been associated with alterations in gene expression related to HSC function and the subsequent development of a myeloproliferative disorder in aging female mice. We sorted the most primitive population of HSCs with the highest stem cell potential (Long-term, or LT-HSCs) from 18-month-old AhR-null-allele (AhR-KO) and WT mice and analyzed gene expression using microarray to determine alterations in gene expression and cell signaling networks in HSCs that could potentially contribute to the aging phenotype of AhR-KO mice. Comparisons with previous array data from 8-week old mice indicated that aging alone is sufficient to alter gene expression. In addition, a significant number of gene expression differences were observed in aged LT-HSCs that are dependent on both aging and lack of AhR. Pathway analysis of these genes revealed networks related to hematopoietic stem cell activity or function. qPCR was used to confirm the differential expression of a subset of these genes, focusing on genes that may represent novel AhR targets due to the presence of a putative AhR binding site in their upstream regulatory region. We verified differential expression of PDGF-D, Smo, Wdfy1, Zbtb37 and Zfp382. Pathway analysis of this subset of genes revealed overlap between cellular functions of the novel AhR targets and AhR itself. Lentiviral-mediated knockdown of AhR in lineage-negative hematopoietic cells was sufficient to induce changes in all five of the candidate AhR targets identified. Taken together, these data suggest a role for AhR in HSC functional regulation, and identify novel HSC AhR target genes that may contribute to the phenotypes observed in AhR-KO mice. PMID:26208102

Quantitative analysis of nanoscale intranuclear structural alterations in hippocampal cells in chronic alcoholism via transmission electron microscopy imaging.

PubMed

Sahay, Peeyush; Shukla, Pradeep K; Ghimire, Hemendra M; Almabadi, Huda M; Tripathi, Vibha; Mohanty, Samarendra K; Rao, Radhakrishna; Pradhan, Prabhakar

2017-03-01

Chronic alcoholism is known to alter the morphology of the hippocampus, an important region of cognitive function in the brain. Therefore, to understand the effect of chronic alcoholism on hippocampal neural cells, we employed a mouse model of chronic alcoholism and quantified intranuclear nanoscale structural alterations in these cells. Transmission electron microscopy (TEM) images of hippocampal neurons were obtained, and the degree of structural alteration in terms of mass density fluctuation was determined using the light-localization properties of optical media generated from TEM imaging. The results, which were obtained at length scales ranging from ~30 to 200 nm, show that 10-12 week-old mice fed a Lieber-DeCarli liquid (alcoholic) diet had a higher degree of structural alteration than control mice fed a normal diet without alcohol. The degree of structural alteration became significantly distinguishable at a sample length of ~100 nm, which is the typical length scale of the building blocks of cells, such as DNA, RNA, proteins and lipids. Interestingly, different degrees of structural alteration at such length scales suggest possible structural rearrangement of chromatin inside the nuclei in chronic alcoholism.

Quantitative analysis of nanoscale intranuclear structural alterations in hippocampal cells in chronic alcoholism via transmission electron microscopy imaging

NASA Astrophysics Data System (ADS)

Sahay, Peeyush; Shukla, Pradeep K.; Ghimire, Hemendra M.; Almabadi, Huda M.; Tripathi, Vibha; Mohanty, Samarendra K.; Rao, Radhakrishna; Pradhan, Prabhakar

2017-04-01

Chronic alcoholism is known to alter the morphology of the hippocampus, an important region of cognitive function in the brain. Therefore, to understand the effect of chronic alcoholism on hippocampal neural cells, we employed a mouse model of chronic alcoholism and quantified intranuclear nanoscale structural alterations in these cells. Transmission electron microscopy (TEM) images of hippocampal neurons were obtained, and the degree of structural alteration in terms of mass density fluctuation was determined using the light-localization properties of optical media generated from TEM imaging. The results, which were obtained at length scales ranging from ~30 to 200 nm, show that 10-12 week-old mice fed a Lieber-DeCarli liquid (alcoholic) diet had a higher degree of structural alteration than control mice fed a normal diet without alcohol. The degree of structural alteration became significantly distinguishable at a sample length of ~100 nm, which is the typical length scale of the building blocks of cells, such as DNA, RNA, proteins and lipids. Interestingly, different degrees of structural alteration at such length scales suggest possible structural rearrangement of chromatin inside the nuclei in chronic alcoholism.

Interactions between macrophage/Kupffer cells and hepatocytes in surgical sepsis

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

West, M.A.

Experiments were performed to investigate the role of Kupffer cell/macrophage interactions with hepatocytes in modulating liver function during infections using direct in vitro cocultivation of rat macrophages or Kupffer cells with rat hepatocytes. Protein synthesis was assayed as a sensitive indicator of integrated hepatocellular function by measuring {sup 3}H-leucine incorporation into hepatocyte protein. Septic stimuli such as lipoploysaccharide and killed bacteria were added to cocultures of hepatocytes and macrophages or Kupffer cells and the responses compared to hepatocytes alone. Information about the types of proteins synthesized by hepatocytes under various culture conditions was determined using polyacrylamide gel electrophoresis and autoradiography.more » These experiments showed that septic stimuli alter the amount and type of protein synthesized by hepatocytes and had no direct effect on hepatocytes in the absence of macrophages or Kupffer cells. The mediator(s) appears to be a heat labile, soluble monokine(s) which is distinct from interleukin-1 or tumor necrosis factor. The important role of Kupffer cells/macrophages in mediating alterations in hepatocellular function in sepsis may ultimately improve patient care.« less

The central role of muscle stem cells in regenerative failure with aging

PubMed Central

Blau, Helen M; Cosgrove, Benjamin D; Ho, Andrew T V

2016-01-01

Skeletal muscle mass, function, and repair capacity all progressively decline with aging, restricting mobility, voluntary function, and quality of life. Skeletal muscle repair is facilitated by a population of dedicated muscle stem cells (MuSCs), also known as satellite cells, that reside in anatomically defined niches within muscle tissues. In adult tissues, MuSCs are retained in a quiescent state until they are primed to regenerate damaged muscle through cycles of self-renewal divisions. With aging, muscle tissue homeostasis is progressively disrupted and the ability of MuSCs to repair injured muscle markedly declines. Until recently, this decline has been largely attributed to extrinsic age-related alterations in the microenvironment to which MuSCs are exposed. However, as highlighted in this Perspective, recent reports show that MuSCs also progressively undergo cell-intrinsic alterations that profoundly affect stem cell regenerative function with aging. A more comprehensive understanding of the interplay of stem cell–intrinsic and extrinsic factors will set the stage for improving cell therapies capable of restoring tissue homeostasis and enhancing muscle repair in the aged. PMID:26248268

Cell Shape Change by Drebrin.

PubMed

Hayashi, Kensuke

2017-01-01

Drebrin is localized in actin-rich regions of neuronal and non-neuronal cells. In mature neurons, its localization is strictly restricted to the postsynaptic sites. In order to understand the function of drebrin in cells, many studies have been performed to examine the effect of overexpression or knocking down of drebrin in various cell types, including neurons, myoblasts, kidney cells, and intestinal epithelial cells. In most cases alteration of cell shape and impairment or facilitation of actin-based activities of these cells were observed. Interestingly, overexpression of drebrin in matured neurons results in the alteration in dendritic spine morphology. Further studies have shown alteration in the localization of postsynaptic receptors and even changes in synaptic transmission caused by drebrin overexpression or depletion in neurons. These drebrin's effects are thought to come from drebrin's actin-cross-linking activity or competitive binding to actin against tropomyosin, fascin, and α-actinin. Furthermore, drebrin binds to various molecules, such as homer, EB3, and cell-cell junctional proteins, indicating that drebrin is a multifunctional cytoskeletal regulator.

Quantitative, Phenotypical, and Functional Characterization of Cellular Immunity in Children and Adolescents With Down Syndrome.

PubMed

Schoch, Justine; Rohrer, Tilman R; Kaestner, Michael; Abdul-Khaliq, Hashim; Gortner, Ludwig; Sester, Urban; Sester, Martina; Schmidt, Tina

2017-05-15

Infections and autoimmune disorders are more frequent in Down syndrome, suggesting abnormality of adaptive immunity. Although the role of B cells and antibodies is well characterized, knowledge regarding T cells is limited. Lymphocyte subpopulations of 40 children and adolescents with Down syndrome and 51 controls were quantified, and phenotype and functionality of antigen-specific effector T cells were analyzed with flow cytometry after polyclonal and pathogen-specific stimulation (with varicella-zoster virus [VZV] and cytomegalovirus [CMV]). Results were correlated with immunoglobulin (Ig) G responses. Apart from general alterations in the percentage of lymphocytes, regulatory T cells, and T-helper 1 and 17 cells, all major T-cell subpopulations showed higher expression of the inhibitory receptor PD-1. Polyclonally stimulated effector CD4+ T-cell frequencies were significantly higher in subjects with Down syndrome, whereas their inhibitory receptor expression (programmed cell death 1 [PD-1] and cytotoxic T-lymphocyte antigen 4 [CTLA-4]) was similar to that of controls and cytokine expression profiles were only marginally altered. Pathogen-specific immunity showed age-appropriate levels of endemic infection, with correlation of CMV-specific cellular and humoral immunity in all subjects. Among VZV IgG-positive individuals, a higher percentage of VZV-specific T-cell-positive subjects was seen in those with Down syndrome. Despite alterations in lymphocyte subpopulations, individuals with Down syndrome can mount effector T-cell responses with similar phenotype and functionality as controls but may require higher effector T-cell frequencies to ensure pathogen control. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Contacting co-culture of human retinal microvascular endothelial cells alters barrier function of human embryonic stem cell derived retinal pigment epithelial cells.

PubMed

Skottman, H; Muranen, J; Lähdekorpi, H; Pajula, E; Mäkelä, K; Koivusalo, L; Koistinen, A; Uusitalo, H; Kaarniranta, K; Juuti-Uusitalo, K

2017-10-01

Here we evaluated the effects of human retinal microvascular endothelial cells (hREC) on mature human embryonic stem cell (hESC) derived retinal pigment epithelial (RPE) cells. The hESC-RPE cells (Regea08/017, Regea08/023 or Regea11/013) and hREC (ACBRI 181) were co-cultured on opposite sides of transparent membranes for up to six weeks. Thereafter barrier function, small molecule permeability, localization of RPE and endothelial cell marker proteins, cellular fine structure, and growth factor secretion of were evaluated. After co-culture, the RPE specific CRALBP and endothelial cell specific von Willebrand factor were appropriately localized. In addition, the general morphology, pigmentation, and fine structure of hESC-RPE cells were unaffected. Co-culture increased the barrier function of hESC-RPE cells, detected both with TEER measurements and cumulative permeability of FD4 - although the differences varied among the cell lines. Co-culturing significantly altered VEGF and PEDF secretion, but again the differences were cell line specific. The results of this study showed that co-culture with hREC affects hESC-RPE functionality. In addition, co-culture revealed drastic cell line specific differences, most notably in growth factor secretion. This model has the potential to be used as an in vitro outer blood-retinal barrier model for drug permeability testing. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

In vitro model to study the effects of matrix stiffening on Ca2+ handling and myofilament function in isolated adult rat cardiomyocytes

PubMed Central

Najafi, Aref; Fontoura, Dulce; Valent, Erik; Goebel, Max; Kardux, Kim; Falcão‐Pires, Inês; van der Velden, Jolanda

2017-01-01

Key points This paper describes a novel model that allows exploration of matrix‐induced cardiomyocyte adaptations independent of the passive effect of matrix rigidity on cardiomyocyte function.Detachment of adult cardiomyocytes from the matrix enables the study of matrix effects on cell shortening, Ca2+ handling and myofilament function.Cell shortening and Ca2+ handling are altered in cardiomyocytes cultured for 24 h on a stiff matrix.Matrix stiffness‐impaired cardiomyocyte contractility is reversed upon normalization of extracellular stiffness.Matrix stiffness‐induced reduction in unloaded shortening is more pronounced in cardiomyocytes isolated from obese ZSF1 rats with heart failure with preserved ejection fraction compared to lean ZSF1 rats. Abstract Extracellular matrix (ECM) stiffening is a key element of cardiac disease. Increased rigidity of the ECM passively inhibits cardiac contraction, but if and how matrix stiffening also actively alters cardiomyocyte contractility is incompletely understood. In vitro models designed to study cardiomyocyte–matrix interaction lack the possibility to separate passive inhibition by a stiff matrix from active matrix‐induced alterations of cardiomyocyte properties. Here we introduce a novel experimental model that allows exploration of cardiomyocyte functional alterations in response to matrix stiffening. Adult rat cardiomyocytes were cultured for 24 h on matrices of tuneable stiffness representing the healthy and the diseased heart and detached from their matrix before functional measurements. We demonstrate that matrix stiffening, independent of passive inhibition, reduces cell shortening and Ca2+ handling but does not alter myofilament‐generated force. Additionally, detachment of adult cultured cardiomyocytes allowed the transfer of cells from one matrix to another. This revealed that stiffness‐induced cardiomyocyte changes are reversed when matrix stiffness is normalized. These matrix stiffness‐induced changes in cardiomyocyte function could not be explained by adaptation in the microtubules. Additionally, cardiomyocytes isolated from stiff hearts of the obese ZSF1 rat model of heart failure with preserved ejection fraction show more pronounced reduction in unloaded shortening in response to matrix stiffening. Taken together, we introduce a method that allows evaluation of the influence of ECM properties on cardiomyocyte function separate from the passive inhibitory component of a stiff matrix. As such, it adds an important and physiologically relevant tool to investigate the functional consequences of cardiomyocyte–matrix interactions. PMID:28485491

Cancer Cells Regulate Biomechanical Properties of Human Microvascular Endothelial Cells*

PubMed Central

Mierke, Claudia Tanja

2011-01-01

Metastasis is a key event of malignant tumor progression. The capability to metastasize depends on the ability of the cancer cell to migrate into connective tissue, adhere, and possibly transmigrate through the endothelium. Previously we reported that the endothelium does not generally act as barrier for cancer cells to migrate in three-dimensional extracellular matrices (3D-ECMs). Instead, the endothelium acts as an enhancer or a promoter for the invasiveness of certain cancer cells. How invasive cancer cells diminish the endothelial barrier function still remains elusive. Therefore, this study investigates whether invasive cancer cells can decrease the endothelial barrier function through alterations of endothelial biomechanical properties. To address this, MDA-MB-231 breast cancer cells were used that invade deeper and more numerous into 3D-ECMs when co-cultured with microvascular endothelial cells. Using magnetic tweezer measurements, MDA-MB-231 cells were found to alter the mechanical properties of endothelial cells by reducing endothelial cell stiffness. Using spontaneous bead diffusion, actin cytoskeletal remodeling dynamics were shown to be increased in endothelial cells co-cultured with MDA-MB-231 cells compared with mono-cultured endothelial cells. In addition, knockdown of the α5 integrin subunit in highly transmigrating α5β1high cells derived from breast, bladder, and kidney cancer cells abolished the endothelial invasion-enhancing effect comparable with the inhibition of myosin light chain kinase. These results indicate that the endothelial invasion-enhancing effect is α5β1 integrin-dependent. Moreover, inhibition of Rac-1, Rho kinase, MEK kinase, and PI3K reduced the endothelial invasion-enhancing effect, indicating that signaling via small GTPases may play a role in the endothelial facilitated increased invasiveness of cancer cells. In conclusion, decreased stiffness and increased cytoskeletal remodeling dynamics of endothelial cells may account for the breakdown of endothelial barrier function, suggesting that biomechanical alterations are sufficient to facilitate the transmigration and invasion of invasive cancer cells into 3D-ECMs. PMID:21940631

Immunoregulation of follicular renewal, selection, POF, and menopause in vivo, vs. neo-oogenesis in vitro, POF and ovarian infertility treatment, and a clinical trial

PubMed Central

2012-01-01

The immune system plays an important role in the regulation of tissue homeostasis ("tissue immune physiology"). Function of distinct tissues during adulthood, including the ovary, requires (1) Renewal from stem cells, (2) Preservation of tissue-specific cells in a proper differentiated state, which differs among distinct tissues, and (3) Regulation of tissue quantity. Such morphostasis can be executed by the tissue control system, consisting of immune system-related components, vascular pericytes, and autonomic innervation. Morphostasis is established epigenetically, during morphogenetic (developmental) immune adaptation, i.e., during the critical developmental period. Subsequently, the tissues are maintained in a state of differentiation reached during the adaptation by a “stop effect” of resident and self renewing monocyte-derived cells. The later normal tissue is programmed to emerge (e.g., late emergence of ovarian granulosa cells), the earlier its function ceases. Alteration of certain tissue differentiation during the critical developmental period causes persistent alteration of that tissue function, including premature ovarian failure (POF) and primary amenorrhea. In fetal and adult human ovaries the ovarian surface epithelium cells called ovarian stem cells (OSC) are bipotent stem cells for the formation of ovarian germ and granulosa cells. Recently termed oogonial stem cells are, in reality, not stem but already germ cells which have the ability to divide. Immune system-related cells and molecules accompany asymmetric division of OSC resulting in the emergence of secondary germ cells, symmetric division, and migration of secondary germ cells, formation of new granulosa cells and fetal and adult primordial follicles (follicular renewal), and selection and growth of primary/preantral, and dominant follicles. The number of selected follicles during each ovarian cycle is determined by autonomic innervation. Morphostasis is altered with advancing age, due to degenerative changes of the immune system. This causes cessation of oocyte and follicular renewal at 38 +/-2 years of age due to the lack of formation of new granulosa cells. Oocytes in primordial follicles persisting after the end of the prime reproductive period accumulate genetic alterations resulting in an exponentially growing incidence of fetal trisomies and other genetic abnormalities with advanced maternal age. The secondary germ cells also develop in the OSC cultures derived from POF and aging ovaries. In vitro conditions are free of immune mechanisms, which prevent neo-oogenesis in vivo. Such germ cells are capable of differentiating in vitro into functional oocytes. This may provide fresh oocytes and genetically related children to women lacking the ability to produce their own follicular oocytes. Further study of "immune physiology" may help us to better understand ovarian physiology and pathology, including ovarian infertility caused by POF or by a lack of ovarian follicles with functional oocytes in aging ovaries. The observations indicating involvement of immunoregulation in physiological neo-oogenesis and follicular renewal from OSC during the fetal and prime reproductive periods are reviewed as well as immune system and age-independent neo-oogenesis and oocyte maturation in OSC cultures, perimenopausal alteration of homeostasis causing disorders of many tissues, and the first OSC culture clinical trial. PMID:23176151

Altered Actin Dynamics and Functions of Osteoblast-Like Cells in Parabolic Flight may Involve ERK1/2

NASA Astrophysics Data System (ADS)

Dai, Zhongquan; Tan, Yingjun; Yang, Fen; Qu, Lina; Zhang, Hongyu; Wan, Yumin; Li, Yinghui

2011-01-01

Osteoblasts are sensitive to mechanical stressors such as gravity and alter their cytoskeletons and functions to adapt; however, the contribution of gravity to this phenomenon is not well understood. In this study, we investigated the effects of acute gravitational changes on the structure and function of osteoblast ROS17/2.8 as generated by parabolic flight. The changes in microfilament cytoskeleton was observed by immunofluorescence stain of Texas red conjugated Phalloidin and Alexa Fluor 488 conjugated DNase I for F-actin and G-actin, respectively. To examine osteoblast function, ALP (alkaline phosphatase) activity, osteocalcin secretions and the expression of ALP, COL1A1 (collagen type I alpha 1 chain) and osteocalcin were detected by modified Gomori methods, radioimmunity and RT-PCR, respectively. Double fluorescence staining of phosphorylated p44/42 and F-actin were performed to observe their colocalization relationship. The established semi-quantitative analysis method of fluorescence intensity of EGFP was used to detect the activity changes of COL1A1 promoter in EGFP-ROS cells with MAPK inhibitor PD98059 or F-actin inhibitor cytochalasin B. Results indicate that the altered gravity induced the reorganization of microfilament cytoskeletons of osteoblasts. After 3 h parabolic flight, F-actin of osteoblast cytoskeleton became thicker and directivity, whereas G-actin shrunk and became more concentrated at the edge of nucleus. The excretion of osteocalcin, the activity of ALP and the expression of mRNA decreased. Colocalization analysis indicated that phosphorylated p44/42 MAPK was coupled with F-actin. Inhibitor PD98059 and cytochalasin B decreased the fluorescence intensity of EGFP-ROS cells. Above results suggest that short time gravity variations induce the adjustment of osteoblast structure and functional and ERK1/2 signaling maybe involve these responses. We believe that it is an adaptive method of the osteoblasts to gravity alteration that structure alteration inhibits the function performing.

Spaceflight alters immune cell function and distribution

NASA Technical Reports Server (NTRS)

Sonnenfeld, Gerald; Mandel, Adrian D.; Konstantinova, Irina V.; Berry, Wallace D.; Taylor, Gerald R.; Lesniak, A. T.; Fuchs, Boris B.; Rakhmilevich, Alexander L.

1992-01-01

Experiments are described which were performed onboard Cosmos 2044 to determine spaceflight effects on immunologically important cell function and distribution. Results indicate that bone marrow cells from flown and suspended rats exhibited a decreased response to a granulocyte/monocyte colony-stimulating factor compared with the bone marrow cells from control rats. Bone marrow cells showed an increase in the percentage of cells expressing markers for helper T-cells in the myelogenous population and increased percentages of anti-asialo granulocyte/monocyte-1-bearing interleulin-2 receptor bearing pan T- and helper T-cells in the lymphocytic population.

Shrinkage of X cells in the lateral geniculate nucleus after monocular deprivation revealed by FoxP2 labeling.

PubMed

Duffy, Kevin R; Holman, Kaitlyn D; Mitchell, Donald E

2014-05-01

The parallel processing of visual features by distinct neuron populations is a central characteristic of the mammalian visual system. In the A laminae of the cat dorsal lateral geniculate nucleus (dLGN), parallel processing streams originate from two principal neuron types, called X and Y cells. Disruption of visual experience early in life by monocular deprivation has been shown to alter the structure and function of Y cells, but the extent to which deprivation influences X cells remains less clear. A transcription factor, FoxP2, has recently been shown to selectively label X cells in the ferret dLGN and thus provides an opportunity to examine whether monocular deprivation alters the soma size of X cells. In this study, FoxP2 labeling was examined in the dLGN of normal and monocularly deprived cats. The characteristics of neurons labeled for FoxP2 were consistent with FoxP2 being a marker for X cells in the cat dLGN. Monocular deprivation for either a short (7 days) or long (7 weeks) duration did not alter the density of FoxP2-positive neurons between nondeprived and deprived dLGN layers. However, for each deprived animal examined, measurement of the cross-sectional area of FoxP2-positive neurons (X cells) revealed that within deprived layers, X cells were smaller by approximately 20% after 7 days of deprivation, and by approximately 28% after 7 weeks of deprivation. The observed alteration to the cross-sectional area of X cells indicates that perturbation of this major pathway contributes to the functional impairments that develop from monocular deprivation.

Streptozotocin alters glucose transport, connexin expression and endoplasmic reticulum functions in neurons and astrocytes.

PubMed

Biswas, Joyshree; Gupta, Sonam; Verma, Dinesh Kumar; Singh, Sarika

2017-07-25

The study was undertaken to explore the cell-specific streptozotocin (STZ)-induced mechanistic alterations. STZ-induced rodent model is a well-established experimental model of Alzheimer's disease (AD) and in our previous studies we have established it as an in vitro screening model of AD by employing N2A neuronal cells. Therefore, STZ was selected in the present study to understand the STZ-induced cell-specific alterations by utilizing neuronal N2A and astrocytes C6 cells. Both neuronal and astrocyte cells were treated with STZ at 10, 50, 100 and 1000μM concentrations for 48h. STZ exposure caused significant decline in cellular viability and augmented cytotoxicity of cells involving astrocytes activation. STZ treatment also disrupted the energy metabolism by altered glucose uptake and its transport in both cells as reflected with decreased expression of glucose transporters (GLUT) 1/3. The consequent decrease in ATP level and decreased mitochondrial membrane potential was also observed in both the cells. STZ caused increased intracellular calcium which could cause the initiation of endoplasmic reticulum (ER) stress. Significant upregulation of ER stress-related markers were observed in both cells after STZ treatment. The cellular communication of astrocytes and neurons was altered as reflected by increased expression of connexin 43 along with DNA fragmentation. STZ-induced apoptotic death was evaluated by elevated expression of caspase-3 and PI/Hoechst staining of cells. In conclusion, study showed that STZ exert alike biochemical alterations, ER stress and cellular apoptosis in both neuronal and astrocyte cells. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

The human T-cell leukemia virus type 1 p13II protein: effects on mitochondrial function and cell growth

PubMed Central

D’Agostino, DM; Silic-Benussi, M; Hiraragi, H; Lairmore, MD; Ciminale, V

2011-01-01

p13II of human T-cell leukemia virus type 1 (HTLV-1) is an 87-amino-acid protein that is targeted to the inner mitochondrial membrane. p13II alters mitochondrial membrane permeability, producing a rapid, membrane potential-dependent influx of K+. These changes result in increased mitochondrial matrix volume and fragmentation and may lead to depolarization and alterations in mitochondrial Ca2+ uptake/retention capacity. At the cellular level, p13II has been found to interfere with cell proliferation and transformation and to promote apoptosis induced by ceramide and Fas ligand. Assays carried out in T cells (the major targets of HTLV-1 infection in vivo) demonstrate that p13II-mediated sensitization to Fas ligand-induced apoptosis can be blocked by an inhibitor of Ras farnesylation, thus implicating Ras signaling as a downstream target of p13II function. PMID:15761473

Ultrastructural and some functional changes in tumor cells treated with stabilized iron oxide nanoparticles.

PubMed

Yurchenko, O V; Todor, I N; Khayetsky, I K; Tregubova, N A; Lukianova, N Yu; Chekhun, V F

2010-12-01

To study the ultrastructure and some functional indexes of tumor cells treated with stabilized iron nanoparticles in vitro. 3-[4,5dimethylthiazol-2-1]-2,5-diphenyltetrazolium bromide (MTT)-test, electron microscopy, polarography with applying of closed Clark's electrode. It was shown that cultivation of cells with stabilized Fe(3)O(4) leads to intracellular accumulation of ferromagnetic nanoparticles. The most active ferromagnetic uptake by cells has been observed after 24 and 48 h of incubation. The presence of ferromagnetic in cells led to altered mitochondrial structure that caused the decrease of oxygen uptake rate in the cells of all studied lines. Ferromagnetic released from the majority of cells via exocytosis or clasmacytosis after a certain period of time. The number of dead cells or cells with severe damage was moderate, so cytotoxic action of stabilized iron oxide nanoparticles was minimal toward the studied cell lines. the presence of ferromagnetic nanoparticles in culture medium led to alterations in mitochondria ultrastructural organization and decrease of oxygen uptake by mitochondria in sensitive and anticancer-drugs resistant cells.

Distinctive Regulatory T Cells and Altered Cytokine Profile Locally in the Airways of Young Smokers with Normal Lung Function

PubMed Central

Ostadkarampour, Mahyar; Müller, Malin; Öckinger, Johan; Kullberg, Susanna; Lindén, Anders; Eklund, Anders; Grunewald, Johan; Wahlström, Jan

2016-01-01

Smoking influences the immune system in different ways and, hypothetically, effects on pulmonary effector and regulatory T cells emerge as potentially detrimental. Therefore, we characterized the frequencies and characteristics of CD4+ and CD8+ T cell subsets in the blood and lungs of young tobacco smokers. Bronchoalveolar lavage (BAL) and peripheral blood were obtained from healthy moderate smokers (n = 18; 2–24 pack-years) and never-smokers (n = 15), all with normal lung function. Cells were stimulated ex vivo and key intracellular cytokines (IFNγ, IL-17, IL-10 and TNFα) and transcription factors (Foxp3, T-bet and Helios) were analyzed using flow cytometry. Our results indicate that smoking is associated with a decline in lung IL-17+ CD4+ T cells, increased IFNγ+ CD8+ T cells and these alterations relate to the history of daily cigarette consumption. There is an increased fraction of Foxp3+ regulatory T cells being Helios- in the lungs of smokers. Cytokine production is mainly confined to the Helios- T cells, both in regulatory and effector subsets. Moreover, we detected a decline of Helios+Foxp3- postulated regulatory CD8+ T cells in smokers. These alterations in the immune system are likely to increase risk for infection and may have implications for autoimmune processes initiated in the lungs among tobacco smokers. PMID:27798682

The role of Epstein–Barr virus in epithelial malignancies

PubMed Central

Tsao, Sai-Wah; Tsang, Chi Man; To, Ka-Fai; Lo, Kwok-Wai

2015-01-01

The close association of Epstein–Barr virus (EBV) infection with non-keratinizing nasopharyngeal carcinomas and a subset of gastric carcinomas suggests that EBV infection is a crucial event in these cancers. The difficulties encountered in infecting and transforming primary epithelial cells in experimental systems suggest that the role of EBV in epithelial malignancies is complex and multifactorial in nature. Genetic alterations in the premalignant epithelium may support the establishment of latent EBV infection, which is believed to be an initiation event. Oncogenic properties have been reported in multiple EBV latent genes. The BamH1 A rightwards transcripts (BARTs) and the BART-encoded microRNAs (miR-BARTs) are highly expressed in EBV-associated epithelial malignancies and may induce malignant transformation. However, enhanced proliferation may not be the crucial function of EBV infection in epithelial malignancies, at least in the early stages of cancer development. EBV-encoded gene products may confer anti-apoptotic properties and promote the survival of infected premalignant epithelial cells harbouring genetic alterations. Multiple EBV-encoded microRNAs have been reported to have immune evasion functions. Genetic alterations in host cells, as well as inflammatory stroma, could modulate the expression of EBV genes and alter the growth properties of infected premalignant epithelial cells, encouraging their selection during carcinogenesis. PMID:25251730

Histone phosphorylation: its role during cell cycle and centromere identity in plants.

PubMed

Zhang, B; Dong, Q; Su, H; Birchler, J A; Han, F

2014-01-01

As the main protein components of chromatin, histones can alter the structural/functional capabilities of chromatin by undergoing extensive post-translational modifications (PTMs) such as phosphorylation, methylation, acetylation, ubiquitination, sumoylation, and so on. These PTMs are thought to transmit signals from the chromatin to the cell machinery to regulate various processes. Histone phosphorylation is associated with chromosome condensation/segregation, activation of transcription, and DNA damage repair. In this review, we focus on how different histone phosphorylations mark for chromatin change during the cell cycle, the relationship between histone phosphorylation and functional centromeres, and the candidate kinases that trigger and the phosphatase or kinase inhibitors that alter histone phosphorylation. Finally, we review the crosstalk between different PTMs. © 2014 S. Karger AG, Basel.

Interleukin 1 and Tumor Necrosis Factor Inhibit Cardiac Myocyte β -adrenergic Responsiveness

NASA Astrophysics Data System (ADS)

Gulick, Tod; Chung, Mina K.; Pieper, Stephen J.; Lange, Louis G.; Schreiner, George F.

1989-09-01

Reversible congestive heart failure can accompany cardiac allograft rejection and inflammatory myocarditis, conditions associated with an immune cell infiltrate of the myocardium. To determine whether immune cell secretory products alter cardiac muscle metabolism without cytotoxicity, we cultured cardiac myocytes in the presence of culture supernatants from activated immune cells. We observed that these culture supernatants inhibit β -adrenergic agonist-mediated increases in cultured cardiac myocyte contractility and intracellular cAMP accumulation. The myocyte contractile response to increased extracellular Ca2+ concentration is unaltered by prior exposure to these culture supernatants, as is the increase in myocyte intracellular cAMP concentration in response to stimulation with forskolin, a direct adenyl cyclase activator. Inhibition occurs in the absence of alteration in β -adrenergic receptor density or ligand binding affinity. Suppressive activity is attributable to the macrophage-derived cytokines interleukin 1 and tumor necrosis factor. Thus, these observations describe a role for defined cytokines in regulating the hormonal responsiveness and function of contractile cells. The effects of interleukin 1 and tumor necrosis factor on intracellular cAMP accumulation may be a model for immune modulation of other cellular functions dependent upon cyclic nucleotide metabolism. The uncoupling of agonist-occupied receptors from adenyl cyclase suggests that β -receptor or guanine nucleotide binding protein function is altered by the direct or indirect action of cytokines on cardiac muscle cells.

Cellular changes in microgravity and the design of space radiation experiments

NASA Technical Reports Server (NTRS)

Morrison, D. R.

1994-01-01

Cell metabolism, secretion and cell-cell interactions can be altered during space flight. Early radiobiology experiments have demonstrated synergistic effects of radiation and microgravity as indicated by increased mutagenesis, increased chromosome aberrations, inhibited development, and retarded growth. Microgravity-induced changes in immune cell functions include reduced blastogenesis and cell-mediated, delayed-type hypersensitivity responses, increased cytokine secretions, but inhibited cytotoxic effects an macrophage differentiation. These effects are important because of the high radiosensitivity of immune cells. It is difficult to compare ground studies with space radiation biology experiments because of the complexity of the space radiation environment, types of radiation damage and repair mechanisms. Altered intracellular functions and molecular mechanisms must be considered in the design and interpretation of space radiation experiments. Critical steps in radiocarcinogenesis could be affected. New cell systems and hardware are needed to determine the biological effectiveness of the low dose rate, isotropic, multispectral space radiation and the potential usefulness of radioprotectants during space flight.

Altered Methylation Profile of Lymphocytes Is Concordant with Perturbation of Lipids Metabolism and Inflammatory Response in Obesity

PubMed Central

Jacobsen, Mette J.; Mentzel, Caroline M. Junker; Olesen, Ann Sofie; Huby, Thierry; Jørgensen, Claus B.; Barrès, Romain; Fredholm, Merete

2016-01-01

Obesity is associated with immunological perturbations that contribute to insulin resistance. Epigenetic mechanisms can control immune functions and have been linked to metabolic complications, although their contribution to insulin resistance still remains unclear. In this study, we investigated the link between metabolic dysfunction and immune alterations with the epigenetic signature in leukocytes in a porcine model of obesity. Global DNA methylation of circulating leukocytes, adipose tissue leukocyte trafficking, and macrophage polarisation were established by flow cytometry. Adipose tissue inflammation and metabolic function were further characterised by quantification of metabolites and expression levels of genes associated with obesity and inflammation. Here we show that obese pigs showed bigger visceral fat pads, higher levels of circulating LDL cholesterol, and impaired glucose tolerance. These changes coincided with impaired metabolism, sustained macrophages infiltration, and increased inflammation in the adipose tissue. Those immune alterations were linked to global DNA hypermethylation in both B-cells and T-cells. Our results provide novel insight into the possible contribution of immune cell epigenetics into the immunological disturbances observed in obesity. The dramatic changes in the transcriptomic and epigenetic signature of circulating lymphocytes reinforce the concept that epigenetic processes participate in the increased immune cell activation and impaired metabolic functions in obesity. PMID:26798656

Structural and functional changes in acute liver injury.

PubMed

Smuckler, E A

1976-06-01

Carbon tetrachloride produces liver cell injury in a variety of animal species. The first structurally recognizable changes occur in the endoplasmic reticulum, with alteration in ribosome-membrane interactions. Later there is an increase in intracellular fat, and the formation of tangled nets of the ergastoplasm. At no time are there changes in mitochondria or single membrane limited bodies in cells with intact plasmalemma, although a relative increase in cell sap may appear. In dead cells (those with plasmalemma discontinuties) crystalline deposits of calcium phosphatase may be noted. Functional changes are related to the endoplasmic reticulum and the plasma membrane. An early decrease in protein synthesis takes place; an accumulation of neutral lipid is related to this change. Later alterations in the ergastoplasmic functions (e.g., mixed function oxidation) occurs. Carbon tetrachloride is not the active agent; rather, a product of its metabolism, probably the CC1, free radical, is. The mechanisms of injury include macromolecular adduction and peroxide propagation. A third possibility includes a cascade effect with the production of secondary and tertiary products, also toxic in nature, with the ability to produce more widespread damage to intracellular structures.

Hepatitis C virus envelope components alter localization of hepatocyte tight junction-associated proteins and promote occludin retention in the endoplasmic reticulum.

PubMed

Benedicto, Ignacio; Molina-Jiménez, Francisca; Barreiro, Olga; Maldonado-Rodríguez, Alejandra; Prieto, Jesús; Moreno-Otero, Ricardo; Aldabe, Rafael; López-Cabrera, Manuel; Majano, Pedro L

2008-10-01

Hepatocyte tight junctions (TJ) play key roles in characteristic liver functions, including bile formation and secretion. Infection by hepatitis C virus (HCV) may cause alterations of the liver architecture and disruption of the bile duct, which ultimately can lead to cholestasis. Herein, we employed the HCV replicon system to analyze the effect of HCV on TJ organization. TJ-associated proteins occludin, claudin-1, and Zonula Occludens protein-1 (ZO-1) disappeared from their normal localization at the border of adjacent cells in Huh7 clones harboring genomic but not subgenomic replicons expressing only the nonstructural proteins. Furthermore, cells containing genomic replicons showed a cytoplasmic accumulation of occludin in the endoplasmic reticulum (ER). TJ-associated function, measured as FITC-dextran paracellular permeability, of genomic replicon-containing cells, was also altered. Interestingly, clearance of the HCV replicon by interferon-alpha (IFN-alpha) treatment and by short hairpin RNA (shRNA) significantly restored the localization of TJ-associated proteins. Transient expression of all HCV structural proteins, but not core protein alone, altered the localization of TJ-associated proteins in Huh7 cells and in clones with subgenomic replicons. Confocal analysis showed that accumulation of occludin in the ER partially co-localized with HCV envelope glycoprotein E2. E2/occludin association was further confirmed by co-immunoprecipitation and pull-down assays. Additionally, using a cell culture model of HCV infection, we observed the cytoplasmic dot-like accumulation of occludin in infected Huh7 cells. We propose that HCV structural proteins, most likely those of the viral envelope, promote alterations of TJ-associated proteins, which may provide new insights for HCV-related pathogenesis.

The CD20 homologue MS4A4 directs trafficking of KIT toward clathrin-independent endocytosis pathways and thus regulates receptor signaling and recycling

PubMed Central

Cruse, Glenn; Beaven, Michael A.; Music, Stephen C.; Bradding, Peter; Gilfillan, Alasdair M.; Metcalfe, Dean D.

2015-01-01

MS4A family members differentially regulate the cell cycle, and aberrant, or loss of, expression of MS4A family proteins has been observed in colon and lung cancer. However, the precise functions of MS4A family proteins and their mechanistic interactions remain unsolved. Here we report that MS4A4 facilitates trafficking of the receptor tyrosine kinase KIT through endocytic recycling rather than degradation pathways by a mechanism that involves recruitment of KIT to caveolin-1–enriched microdomains. Silencing of MS4A4 in human mast cells altered ligand-induced KIT endocytosis pathways and reduced receptor recycling to the cell surface, thus promoting KIT signaling in the endosomes while reducing that in the plasma membrane, as exemplified by Akt and PLCγ1 phosphorylation, respectively. The altered endocytic trafficking of KIT also resulted in an increase in SCF-induced mast cell proliferation and migration, which may reflect altered signaling in these cells. Our data reveal a novel function for MS4A family proteins in regulating trafficking and signaling, which could have implications in both proliferative and immunological diseases. PMID:25717186

Knockdown of a laccase in Populus deltoides confers altered cell wall chemistry and increased sugar release

DOE PAGES

Bryan, Anthony C.; Jawdy, Sara; Gunter, Lee; ...

2016-04-15

Plant laccases are thought to function in the oxidation of monolignols which leads to higher order lignin formation. Only a hand-full of laccases in plants have been functionally evaluated and as such little is known about the breadth of their impact on cell wall chemistry or structure. Here we describe a previously uncharacterized laccase from Populus, encoded by locus Potri.008G06400, whose reduced expression resulted in transgenic Populus trees with changes in syringyl/guaiacyl (S/G) ratios as well as altered sugar release phenotypes. These phenotypes are consistent with plant biomass exhibiting reduced recalcitrance. Interestingly, the transgene effect on recalcitrance is dependent onmore » a mild pretreatment prior to chemical extraction of sugars. Metabolite profiling suggests the transgene modulates phenolics that are associated with the cell wall structure. Finally, we propose a model in which this particular laccase has a range of functions related to oxidation of phenolics that interact with lignin in the cell wall.« less

Knockdown of a laccase in Populus deltoides confers altered cell wall chemistry and increased sugar release

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

Bryan, Anthony C.; Jawdy, Sara; Gunter, Lee

Plant laccases are thought to function in the oxidation of monolignols which leads to higher order lignin formation. Only a hand-full of laccases in plants have been functionally evaluated and as such little is known about the breadth of their impact on cell wall chemistry or structure. Here we describe a previously uncharacterized laccase from Populus, encoded by locus Potri.008G06400, whose reduced expression resulted in transgenic Populus trees with changes in syringyl/guaiacyl (S/G) ratios as well as altered sugar release phenotypes. These phenotypes are consistent with plant biomass exhibiting reduced recalcitrance. Interestingly, the transgene effect on recalcitrance is dependent onmore » a mild pretreatment prior to chemical extraction of sugars. Metabolite profiling suggests the transgene modulates phenolics that are associated with the cell wall structure. Finally, we propose a model in which this particular laccase has a range of functions related to oxidation of phenolics that interact with lignin in the cell wall.« less

Asymmetric segregation and self-renewal of hematopoietic stem and progenitor cells with endocytic Ap2a2.

PubMed

Ting, Stephen B; Deneault, Eric; Hope, Kristin; Cellot, Sonia; Chagraoui, Jalila; Mayotte, Nadine; Dorn, Jonas F; Laverdure, Jean-Philippe; Harvey, Michael; Hawkins, Edwin D; Russell, Sarah M; Maddox, Paul S; Iscove, Norman N; Sauvageau, Guy

2012-03-15

The stem cell-intrinsic model of self-renewal via asymmetric cell division (ACD) posits that fate determinants be partitioned unequally between daughter cells to either activate or suppress the stemness state. ACD is a purported mechanism by which hematopoietic stem cells (HSCs) self-renew, but definitive evidence for this cellular process remains open to conjecture. To address this issue, we chose 73 candidate genes that function within the cell polarity network to identify potential determinants that may concomitantly alter HSC fate while also exhibiting asymmetric segregation at cell division. Initial gene-expression profiles of polarity candidates showed high and differential expression in both HSCs and leukemia stem cells. Altered HSC fate was assessed by our established in vitro to in vivo screen on a subcohort of candidate polarity genes, which revealed 6 novel positive regulators of HSC function: Ap2a2, Gpsm2, Tmod1, Kif3a, Racgap1, and Ccnb1. Interestingly, live-cell videomicroscopy of the endocytic protein AP2A2 shows instances of asymmetric segregation during HSC/progenitor cell cytokinesis. These results contribute further evidence that ACD is functional in HSC self-renewal, suggest a role for Ap2a2 in HSC activity, and provide a unique opportunity to prospectively analyze progeny from HSC asymmetric divisions.

Examining changes in cellular communication in neuroendocrine cells after noble metal nanoparticle exposure.

PubMed

Love, Sara A; Liu, Zhen; Haynes, Christy L

2012-07-07

As nanoparticles enjoy increasingly widespread use in commercial applications, the potential for unintentional exposure has become much more likely during any given day. Researchers in the field of nanotoxicity are working to determine the physicochemical nanoparticle properties that lead to toxicity in an effort to establish safe design rules. This work explores the effects of noble metal nanoparticle exposure in murine chromaffin cells, focusing on examining the effects of size and surface functionality (coating) in silver and gold, respectively. Carbon-fibre microelectrode amperometry was utilized to examine the effect of exposure on exocytosis function, at the single cell level, and provided new insights into the compromised functions of cells. Silver nanoparticles of varied size, between 15 and 60 nm diameter, were exposed to cells and found to alter the release kinetics of exocytosis for those cells exposed to the smallest examined size. Effects of gold were examined after modification with two commonly used 'bio-friendly' polymers, either heparin or poly (ethylene glycol), and gold nanoparticles were found to induce altered cellular adhesion or the number of chemical messenger molecules released, respectively. These results support the body of work suggesting that noble metal nanoparticles perturb exocytosis, typically altering the number of molecules and kinetics of release, and supports a direct disruption of the vesicle matrix by the nanoparticle. Overall, it is clear that various nanoparticle physicochemical properties, including size and surface coating, do modulate changes in cellular communication via exocytosis.

Enhanced Heme Function and Mitochondrial Respiration Promote the Progression of Lung Cancer Cells

PubMed Central

Alam, Md Maksudul; Shah, Ajit; Cao, Thai M.; Sullivan, Laura A.; Brekken, Rolf; Zhang, Li

2013-01-01

Lung cancer is the leading cause of cancer-related mortality, and about 85% of the cases are non-small-cell lung cancer (NSCLC). Importantly, recent advance in cancer research suggests that altering cancer cell bioenergetics can provide an effective way to target such advanced cancer cells that have acquired mutations in multiple cellular regulators. This study aims to identify bioenergetic alterations in lung cancer cells by directly measuring and comparing key metabolic activities in a pair of cell lines representing normal and NSCLC cells developed from the same patient. We found that the rates of oxygen consumption and heme biosynthesis were intensified in NSCLC cells. Additionally, the NSCLC cells exhibited substantially increased levels in an array of proteins promoting heme synthesis, uptake and function. These proteins include the rate-limiting heme biosynthetic enzyme ALAS, transporter proteins HRG1 and HCP1 that are involved in heme uptake, and various types of oxygen-utilizing hemoproteins such as cytoglobin and cytochromes. Several types of human tumor xenografts also displayed increased levels of such proteins. Furthermore, we found that lowering heme biosynthesis and uptake, like lowering mitochondrial respiration, effectively reduced oxygen consumption, cancer cell proliferation, migration and colony formation. In contrast, lowering heme degradation does not have an effect on lung cancer cells. These results show that increased heme flux and function are a key feature of NSCLC cells. Further, increased generation and supply of heme and oxygen-utilizing hemoproteins in cancer cells will lead to intensified oxygen consumption and cellular energy production by mitochondrial respiration, which would fuel cancer cell proliferation and progression. The results show that inhibiting heme and respiratory function can effectively arrest the progression of lung cancer cells. Hence, understanding heme function can positively impact on research in lung cancer biology and therapeutics. PMID:23704904

Gene-Chemical Interactions in the Developing Mammalian Nervous System: Effects on Proliferation, Neurogenesis and Differentiation

PubMed Central

Fox, Donald A.; Opanashuk, Lisa; Zharkovsky, Aleksander; Weiss, Bernie

2010-01-01

The orderly formation of the nervous system requires a multitude of complex, integrated and simultaneously occurring processes. Neural progenitor cells expand through proliferation, commit to different cell fates, exit the cell cycle, generate different neuronal and glial cell types, and new neurons migrate to specified areas and establish synaptic connections. Gestational and perinatal exposure to environmental toxicants, pharmacological agents and drugs of abuse produce immediate, persistent or late-onset alterations in behavioral, cognitive, sensory and/or motor functions. These alterations reflect the disruption of the underlying processes of CNS formation and development. To determine the neurotoxic mechanisms that underlie these deficits it is necessary to analyze and dissect the complex molecular processes that occur during the proliferation, neurogenesis and differentiation of cells. This symposium will provide a framework for understanding the orchestrated events of neurogenesis, the coordination of proliferation and cell fate specification by selected genes, and the effects of well-known neurotoxicants on neurogenesis in the retina, hippocampus and cerebellum. These three tissues share common developmental profiles, mediate diverse neuronal activities and function, and thus provide important substrates for analysis. This paper summarizes four invited talks that were presented at the 12th International Neurotoxicology Association meeting held in Jerusalem, Israel during the summer of 2009. Donald A. Fox described the structural and functional alterations following low-level gestational lead exposure in children and rodents that produced a supernormal electroretinogram and selective increases in neurogenesis and cell proliferation of late-born retinal neurons (rod photoreceptors and bipolar cells), but not Müller glia cells, in mice. Lisa Opanashuk discussed how dioxin [TCDD] binding to the arylhydrocarbon receptor [AhR], a transcription factor that regulates xenobiotic metabolizing enzymes and growth factors, increased granule cell formation and apoptosis in the developing mouse cerebellum. Alex Zharkovsky described how postnatal early postnatal lead exposure decreased cell proliferation, neurogenesis and gene expression in the dentate gyrus of the adult hippocampus and its resultant behavioral effects. Bernard Weiss illustrated how environmental endocrine disruptors produced age- and gender-dependent alterations in synaptogenesis and cognitive behavior. PMID:20381523

Calcium as a cardiovascular toxin in CKD-MBD.

PubMed

Moe, Sharon M

2017-07-01

Disordered calcium balance and homeostasis are common in patients with chronic kidney disease. Such alterations are commonly associated with abnormal bone remodeling, directly and indirectly. Similarly, positive calcium balance may also be a factor in the pathogenesis of extra skeletal soft tissue and arterial calcification. Calcium may directly affect cardiac structure and function through direct effects to alter cell signaling due to abnormal intracellular calcium homeostasis 2) extra-skeletal deposition of calcium and phosphate in the myocardium and small cardiac arterioles, 3) inducing cardiomyocyte hypertrophy through calcium and hormone activation of NFAT signaling mechanisms, and 4) increased aorta calcification resulting in chronic increased afterload leading to hypertrophy. Similarly, calcium may alter vascular smooth muscle cell function and affect cell signaling which may predispose to a proliferative phenotype important in arteriosclerosis and arterial calcification. Thus, disorders of calcium balance and homeostasis due to CKD-MBD may play a role in the high cardiovascular burden observed in patients with CKD. Published by Elsevier Inc.

Small mitochondria-targeting molecules as anti-cancer agents

PubMed Central

Wang, Feng; Ogasawara, Marcia A.; Huang, Peng

2009-01-01

Alterations in mitochondrial structure and functions have long been observed in cancer cells. Targeting mitochondria as a cancer therapeutic strategy has gained momentum in the recent years. The signaling pathways that govern mitochondrial function, apoptosis and molecules that affect mitochondrial integrity and cell viability have been important topics of the recent review in the literature. In this article, we first briefly summarize the rationale and biological basis for developing mitochondrial-targeted compounds as potential anticancer agents, and then provide key examples of small molecules that either directly impact mitochondria or functionally affect the metabolic alterations in cancer cells with mitochondrial dysfunction. The main focus is on the small molecular weight compounds with potential applications in cancer treatment. We also summarize information on the drug developmental stages of the key mitochondria-targeted compounds and their clinical trial status. The advantages and potential shortcomings of targeting the mitochondria for cancer treatment are also discussed. PMID:19995573

The timing and location of glial cell line-derived neurotrophic factor expression determine enteric nervous system structure and function.

PubMed

Wang, Hongtao; Hughes, Inna; Planer, William; Parsadanian, Alexander; Grider, John R; Vohra, Bhupinder P S; Keller-Peck, Cynthia; Heuckeroth, Robert O

2010-01-27

Ret signaling is critical for formation of the enteric nervous system (ENS) because Ret activation promotes ENS precursor survival, proliferation, and migration and provides trophic support for mature enteric neurons. Although these roles are well established, we now provide evidence that increasing levels of the Ret ligand glial cell line-derived neurotrophic factor (GDNF) in mice causes alterations in ENS structure and function that are critically dependent on the time and location of increased GDNF availability. This is demonstrated using two different strains of transgenic mice and by injecting newborn mice with GDNF. Furthermore, because different subclasses of ENS precursors withdraw from the cell cycle at different times during development, increases in GDNF at specific times alter the ratio of neuronal subclasses in the mature ENS. In addition, we confirm that esophageal neurons are GDNF responsive and demonstrate that the location of GDNF production influences neuronal process projection for NADPH diaphorase-expressing, but not acetylcholinesterase-, choline acetyltransferase-, or tryptophan hydroxylase-expressing, small bowel myenteric neurons. We further demonstrate that changes in GDNF availability influence intestinal function in vitro and in vivo. Thus, changes in GDNF expression can create a wide variety of alterations in ENS structure and function and may in part contribute to human motility disorders.

Ca2+ homeostasis in microvascular endothelial cells from an insulin-dependent diabetic model: role of endosomes/lysosomes

NASA Astrophysics Data System (ADS)

Sanka, Shankar C.; Bennett, David C.; Rojas, Jose D.; Tasby, Geraldine B.; Meininger, Cynthia J.; Wu, Guoyao; Wesson, Donald E.; Pfarr, Curtis M.; Martinez-Zaguilan, Raul

2000-04-01

Cytosolic Ca2+ ([Ca2+]cyt) regulates several cellular functions, e.g. cell growth, contraction, secretion, etc. In many cell types, ion homeostasis appears to be coupled with glucose metabolism. In certain cell types, a strict coupling between glycolysis and the activity of Sarcoplasmic/Endoplasmic Reticulum Ca2+-ATPases (SERCA) has been suggested. Glucose metabolism is altered in diabetes. We hypothesize that: (1) Ca2+ homeostasis is altered in microvascular endothelial cells from diabetic animals due to the dysfunction of glycolysis coupling the activity of SERCA; (2) endosomal/lysosomal compartments expressing SERCA are involved in the dysfunction associated with diabetes.

CD4 T lymphocytes from patients with chronic fatigue syndrome have decreased interferon-gamma production and increased sensitivity to dexamethasone.

PubMed

Visser, J; Blauw, B; Hinloopen, B; Brommer, E; de Kloet, E R; Kluft, C; Nagelkerken, L

1998-02-01

A disturbed hypothalamus-pituitary-adrenal gland axis and alterations at the immune system level have been observed in patients with chronic fatigue syndrome (CFS). Glucocorticoids are known to modulate T cell responses; therefore, purified CD4 T cells from CFS patients were studied to determine whether they have an altered sensitivity to dexamethasone (DEX). CD4 T cells from CFS patients produced less interferon-gamma than did cells from controls; by contrast, interleukin-4 production and cell proliferation were comparable. With CD4 T cells from CFS patients (compared with cells from controls), a 10- to 20-fold lower DEX concentration was needed to achieve 50% inhibition of interleukin-4 production and proliferation, indicating an increased sensitivity to DEX in CFS patients. Surprisingly, interferon-gamma production in patients and controls was equally sensitive to DEX. A differential sensitivity of cytokines or CD4 T cell subsets to glucocorticoids might explain an altered immunologic function in CFS patients.

Effects of the space flight environment on the immune system

NASA Technical Reports Server (NTRS)

Sonnenfeld, Gerald; Butel, Janet S.; Shearer, William T.

2003-01-01

Space flight conditions have a dramatic effect on a variety of physiologic functions of mammals, including muscle, bone, and neurovestibular function. Among the physiological functions that are affected when humans or animals are exposed to space flight conditions is the immune response. The focus of this review is on the function of the immune system in space flight conditions during actual space flights, as well as in models of space flight conditions on the earth. The experiments were carried out in tissue culture systems, in animal models, and in human subjects. The results indicate that space flight conditions alter cell-mediated immune responses, including lymphocyte proliferation and subset distribution, and cytokine production. The mechanism(s) of space flight-induced alterations in immune system function remain(s) to be established. It is likely, however, that multiple factors, including microgravity, stress, neuroendocrine factors, sleep disruption, and nutritional factors, are involved in altering certain functions of the immune system. Such alterations could lead to compromised defenses against infections and tumors.

Alterations in protein glycosylation in PMA-differentiated U-937 cells exposed to mineral particles.

PubMed Central

Trabelsi, N; Greffard, A; Pairon, J C; Bignon, J; Zanetti, G; Fubini, B; Pilatte, Y

1997-01-01

Carbohydrate moieties of cell glycoconjugates play a pivotal role in molecular recognition phenomena involved in the regulation of most biological systems and the changes observed in cell surface carbohydrates during cell activation or differentiation frequently modulate certain cell functions. Consequently, some aspects of macrophage response to particle exposure might conceivably result from alterations in glycosylation. Therefore, the effect of mineral particles on protein glycosylation was investigated in phorbol myristate acetate (PMA)-differentiated U-937. Jacalin, a lectin specific for O-glycosylated structures, showed a global increase in O-glycosylation in particle-treated cells. In contrast, no significant modifications were observed with concanavalin A, a lectin that recognizes certain N-glycosylated structures. The sialic acid-specific lectins Sambucus nigra agglutinin and Maackia amurensis agglutinin and the galactose-specific lectin Ricinus communis agglutinin revealed a complex pattern of alterations in glycoprotein glycosylation after crystalline silica or manganese dioxide treatments. Expression of sialyl Lewis(x), a glycosylated structure implicated in leukocyte trafficking, could not be detected in control or treated cells. This finding was consistent with the decrease in sialyl Lewis(x) expression observed during PMA-induced differentiation. In conclusion, various treatments used in this study induced quantitative as well as qualitative changes in protein glycosylation. Whether these changes are due to glycosidase release or to an alteration in glycosyltransferase expression remains to be determined. The potential functional implications of these changes are currently under investigation. Images Figure 1. A Figure 1. B Figure 2. A Figure 2. B Figure 3. A Figure 3. B Figure 3. C Figure 4. PMID:9400716

PGE2 suppresses intestinal T cell function in thermal injury: a cause of enhanced bacterial translocation.

PubMed

Choudhry, M A; Fazal, N; Namak, S Y; Haque, F; Ravindranath, T; Sayeed, M M

2001-09-01

Increased gut bacterial translocation in burn and trauma patients has been demonstrated in a number of previous studies, however, the mechanism for such an increased gut bacterial translocation in injured patients remains poorly understood. Utilizing a rat model of burn injury, in the present study we examined the role of intestinal immune defense by analyzing the T cell functions. We investigated if intestinal T cells dysfunction contributes to bacterial translocation after burn injury. Also our study determined if burn-mediated alterations in intestinal T cell functions are related to enhanced release of PGE2. Finally, we examined whether or not burn-related alterations in intestinal T cell function are due to inappropriate activation of signaling molecule P59fyn, which is required for T cell activation and proliferation. The results presented here showed an increase in gut bacterial accumulation in mesenteric lymph nodes after thermal injury. This was accompanied by a decrease in the intestinal T cell proliferative responses. Furthermore, the treatments of burn-injured animals with PGE2 synthesis blocker (indomethacin or NS398) prevented both the decrease in intestinal T cell proliferation and enhanced bacterial translocation. Finally, our data suggested that the inhibition of intestinal T cell proliferation could result via PGE2-mediated down-regulation of the T cell activation-signaling molecule P59fyn. These findings support a role of T cell-mediated immune defense against bacterial translocation in burn injury.

Bone marrow support of the heart in pressure overload is lost with aging.

PubMed

Sopko, Nikolai A; Turturice, Benjamin A; Becker, Mitchell E; Brown, Chase R; Dong, Feng; Popović, Zoran B; Penn, Marc S

2010-12-21

Exogenous stem cell delivery is under investigation to prevent and treat cardiac dysfunction. It is less studied as to the extent endogenous bone marrow derived stem cells contribute to cardiac homeostais in response to stress and the affects of aging on this stress response. To determine the role of bone marrow (BM) derived stem cells on cardiac homeostasis in response to pressure overload (PO) and how this response is altered by aging. Young (8 weeks) and old (>40 weeks) C57/b6 mice underwent homo- and heterochronic BM transplantation prior to transverse aortic constriction (TAC). We found that older BM is associated with decreased cardiac function following TAC. This decreased function is associated with decrease in BM cell engraftment, increased myocyte apoptosis, decreased myocyte hypertrophy, increased myocardial fibrosis and decreased cardiac function. Additionally, there is a decrease in activation of resident cells within the heart in response to PO in old mice. Interestingly, these effects are not due to alterations in vascular density or inflammation in response to PO or differences in ex vivo stem cell migration between young and old mice. BM derived stem cells are activated in response to cardiac PO, and the recruitment of BM derived cells are involved in cardiac myocyte hypertrophy and maintenance of function in response to PO which is lost with aging.

Normalizing glycosphingolipids restores function in CD4+ T cells from lupus patients

PubMed Central

McDonald, Georgia; Deepak, Shantal; Miguel, Laura; Hall, Cleo J.; Isenberg, David A.; Magee, Anthony I.; Butters, Terry; Jury, Elizabeth C.

2014-01-01

Patients with the autoimmune rheumatic disease systemic lupus erythematosus (SLE) have multiple defects in lymphocyte signaling and function that contribute to disease pathogenesis. Such defects could be attributed to alterations in metabolic processes, including abnormal control of lipid biosynthesis pathways. Here, we reveal that CD4+ T cells from SLE patients displayed an altered profile of lipid raft–associated glycosphingolipids (GSLs) compared with that of healthy controls. In particular, lactosylceramide, globotriaosylceramide (Gb3), and monosialotetrahexosylganglioside (GM1) levels were markedly increased. Elevated GSLs in SLE patients were associated with increased expression of liver X receptor β (LXRβ), a nuclear receptor that controls cellular lipid metabolism and trafficking and influences acquired immune responses. Stimulation of CD4+ T cells isolated from healthy donors with synthetic and endogenous LXR agonists promoted GSL expression, which was blocked by an LXR antagonist. Increased GSL expression in CD4+ T cells was associated with intracellular accumulation and accelerated trafficking of GSL, reminiscent of cells from patients with glycolipid storage diseases. Inhibition of GSL biosynthesis in vitro with a clinically approved inhibitor (N-butyldeoxynojirimycin) normalized GSL metabolism, corrected CD4+ T cell signaling and functional defects, and decreased anti-dsDNA antibody production by autologous B cells in SLE patients. Our data demonstrate that lipid metabolism defects contribute to SLE pathogenesis and suggest that targeting GSL biosynthesis restores T cell function in SLE. PMID:24463447

Normalizing glycosphingolipids restores function in CD4+ T cells from lupus patients.

PubMed

McDonald, Georgia; Deepak, Shantal; Miguel, Laura; Hall, Cleo J; Isenberg, David A; Magee, Anthony I; Butters, Terry; Jury, Elizabeth C

2014-02-01

Patients with the autoimmune rheumatic disease systemic lupus erythematosus (SLE) have multiple defects in lymphocyte signaling and function that contribute to disease pathogenesis. Such defects could be attributed to alterations in metabolic processes, including abnormal control of lipid biosynthesis pathways. Here, we reveal that CD4+ T cells from SLE patients displayed an altered profile of lipid raft-associated glycosphingolipids (GSLs) compared with that of healthy controls. In particular, lactosylceramide, globotriaosylceramide (Gb3), and monosialotetrahexosylganglioside (GM1) levels were markedly increased. Elevated GSLs in SLE patients were associated with increased expression of liver X receptor β (LXRβ), a nuclear receptor that controls cellular lipid metabolism and trafficking and influences acquired immune responses. Stimulation of CD4+ T cells isolated from healthy donors with synthetic and endogenous LXR agonists promoted GSL expression, which was blocked by an LXR antagonist. Increased GSL expression in CD4+ T cells was associated with intracellular accumulation and accelerated trafficking of GSL, reminiscent of cells from patients with glycolipid storage diseases. Inhibition of GSL biosynthesis in vitro with a clinically approved inhibitor (N-butyldeoxynojirimycin) normalized GSL metabolism, corrected CD4+ T cell signaling and functional defects, and decreased anti-dsDNA antibody production by autologous B cells in SLE patients. Our data demonstrate that lipid metabolism defects contribute to SLE pathogenesis and suggest that targeting GSL biosynthesis restores T cell function in SLE.

Proteomic analysis of mitochondria in respiratory epithelial cells infected with human respiratory syncytial virus and functional implications for virus and cell biology.

PubMed

Munday, Diane C; Howell, Gareth; Barr, John N; Hiscox, Julian A

2015-03-01

The aim of this study was to quantitatively characterise the mitochondrial proteome of airway epithelial cells infected with human respiratory syncytial virus (HRSV), a major cause of paediatric illness. Quantitative proteomics, underpinned by stable isotope labelling with amino acids in cell culture, coupled to LC-MS/MS, was applied to mitochondrial fractions prepared from HRSV-infected and mock-infected cells 12 and 24 h post-infection. Datasets were analysed using ingenuity pathway analysis, and the results were validated and characterised using bioimaging, targeted inhibition and gene depletion. The data quantitatively indicated that antiviral signalling proteins converged on mitochondria during HRSV infection. The mitochondrial receptor protein Tom70 was found to act in an antiviral manner, while its chaperone, Hsp90, was confirmed to be a positive viral factor. Proteins associated with different organelles were also co-enriched in the mitochondrial fractions from HRSV-infected cells, suggesting that alterations in organelle dynamics and membrane associations occur during virus infection. Protein and pathway-specific alterations occur to the mitochondrial proteome in a spatial and temporal manner during HRSV infection, suggesting that this organelle may have altered functions. These could be targeted as part of potential therapeutic strategies to disrupt virus biology. © 2014 Royal Pharmaceutical Society.

Glutathione diminishes Dibutyltin- and tributyltin-induced loss of lytic function in human natural killer cells

PubMed Central

Powell, Jeralyn J.; Davis, McLisa V.; Whalen, Margaret M.

2008-01-01

This study investigated whether reduced glutathione (GSH) was able to alter the negative effects of tributyltin (TBT) or dibutyltin (DBT) on the lytic function of human natural killer (NK) cells. NK cells are an intital immune defense against the development of tumors or viral infections. TBT and DBT are widespread environmental contaminants, due to their various industrial applications. Both TBT and DBT have been shown to decrease the ability of NK cells to lyse tumor cells (lytic function). The results indicated that the presence of GSH during exposure of NK cells to TBT or DBT diminished the negative effect of the BT on the lytic function of NK cells. This suggests that interaction TBT and DBT with functionally relevant sulfhydryl groups in NK cells may be part of the mechanism by which they decrease NK lytic function. PMID:18821099

Glutathione diminishes tributyltin- and dibutyltin-induced loss of lytic function in human natural killer cells.

PubMed

Powell, Jeralyn J; Davis, McLisa V; Whalen, Margaret M

2009-01-01

This study investigated whether reduced glutathione (GSH) was able to alter the negative effects of tributyltin (TBT) or dibutyltin (DBT) on the lytic function of human natural killer (NK) cells. NK cells are an initial immune defense against the development of tumors or viral infections. TBT and DBT are widespread environmental contaminants, due to their various industrial applications. Both TBT and DBT have been shown to decrease the ability of NK cells to lyse tumor cells (lytic function). The results indicated that the presence of GSH during the exposure of NK cells to TBT or DBT diminished the negative effect of the butyltin on the lytic function of NK cells. This suggests that the interaction of TBT and DBT with functionally relevant sulfhydryl groups in NK cells may be part of the mechanism by which they decrease NK lytic function.

Inhibition of the alpha-ketoglutarate dehydrogenase complex alters mitochondrial function and cellular calcium regulation.

PubMed

Huang, Hsueh-Meei; Zhang, Hui; Xu, Hui; Gibson, Gary E

2003-01-20

Mitochondrial dysfunction occurs in many neurodegenerative diseases. The alpha-ketoglutarate dehydrogenase complex (KGDHC) catalyzes a key and arguably rate-limiting step of the tricarboxylic acid cycle (TCA). A reduction in the activity of the KGDHC occurs in brains and cells of patients with many of these disorders and may underlie the abnormal mitochondrial function. Abnormalities in calcium homeostasis also occur in fibroblasts from Alzheimer's disease (AD) patients and in cells bearing mutations that lead to AD. Thus, the present studies test whether the reduction of KGDHC activity can lead to the alterations in mitochondrial function and calcium homeostasis. alpha-Keto-beta-methyl-n-valeric acid (KMV) inhibits KGDHC activity in living N2a cells in a dose- and time-dependent manner. Surprisingly, concentration of KMV that inhibit in situ KGDHC by 80% does not alter the mitochondrial membrane potential (MMP). However, similar concentrations of KMV induce the release of cytochrome c from mitochondria into the cytosol, reduce basal [Ca(2+)](i) by 23% (P<0.005), and diminish the bradykinin (BK)-induced calcium release from the endoplasmic reticulum (ER) by 46% (P<0.005). This result suggests that diminished KGDHC activities do not lead to the Ca(2+) abnormalities in fibroblasts from AD patients or cells bearing PS-1 mutations. The increased release of cytochrome c with diminished KGDHC activities will be expected to activate other pathways including cell death cascades. Reductions in this key mitochondrial enzyme will likely make the cells more vulnerable to metabolic insults that promote cell death.

Opioids and the immune system: what is their mechanism of action?

PubMed

Eisenstein, Toby K

2011-12-01

There is a significant amount of literature showing that morphine and other opioids modulate immune responses. The findings support many mechanisms by which this may occur. In vitro experiments provide evidence for direct actions of opioids on immune cells using a variety of functional end points. When these drugs are given in vivo, a plethora of immune parameters are also altered. The paper in this issue of the journal by Zhang et al. provides new information on morphine alteration of immune cell subsets in the spleen and thymus of mice and the potential role of glucocorticoids in these observed phenomena. This Commentary reviews the in vitro activities of morphine on leucocytes, as well as other documented mechanisms by which morphine can alter immune function in vivo. © 2011 The Author. British Journal of Pharmacology © 2011 The British Pharmacological Society.

The histone H2A deubiquitinase Usp16 regulates hematopoiesis and hematopoietic stem cell function.

PubMed

Gu, Yue; Jones, Amanda E; Yang, Wei; Liu, Shanrun; Dai, Qian; Liu, Yudong; Swindle, C Scott; Zhou, Dewang; Zhang, Zhuo; Ryan, Thomas M; Townes, Tim M; Klug, Christopher A; Chen, Dongquan; Wang, Hengbin

2016-01-05

Epigenetic mechanisms play important regulatory roles in hematopoiesis and hematopoietic stem cell (HSC) function. Subunits of polycomb repressive complex 1 (PRC1), the major histone H2A ubiquitin ligase, are critical for both normal and pathological hematopoiesis; however, it is unclear which of the several counteracting H2A deubiquitinases functions along with PRC1 to control H2A ubiquitination (ubH2A) level and regulates hematopoiesis in vivo. Here we investigated the function of Usp16 in mouse hematopoiesis. Conditional deletion of Usp16 in bone marrow resulted in a significant increase of global ubH2A level and lethality. Usp16 deletion did not change HSC number but was associated with a dramatic reduction of mature and progenitor cell populations, revealing a role in governing HSC lineage commitment. ChIP- and RNA-sequencing studies in HSC and progenitor cells revealed that Usp16 bound to many important hematopoietic regulators and that Usp16 deletion altered the expression of genes in transcription/chromosome organization, immune response, hematopoietic/lymphoid organ development, and myeloid/leukocyte differentiation. The altered gene expression was partly rescued by knockdown of PRC1 subunits, suggesting that Usp16 and PRC1 counterbalance each other to regulate cellular ubH2A level and gene expression in the hematopoietic system. We further discovered that knocking down Cdkn1a (p21cip1), a Usp16 target and regulated gene, rescued the altered cell cycle profile and differentiation defect of Usp16-deleted HSCs. Collectively, these studies identified Usp16 as one of the histone H2A deubiquitinases, which coordinates with the H2A ubiquitin ligase PRC1 to regulate hematopoiesis, and revealed cell cycle regulation by Usp16 as key for HSC differentiation.

No effect of the altered peptide ligand NBI-6024 on beta-cell residual function and insulin needs in new-onset type 1 diabetes.

PubMed

Walter, Markus; Philotheou, Areti; Bonnici, François; Ziegler, Anette-G; Jimenez, Roland

2009-11-01

This randomized, four-arm, placebo-controlled, dose-ranging phase 2 trial was conducted to determine whether repeated subcutaneous injections of the altered peptide ligand, NBI-6024, designed to inhibit autoreactive T-cells, improves beta-cell function in patients with recently diagnosed type 1 diabetes. A total of 188 patients, aged 10-35 years, with recently diagnosed type 1 diabetes were randomly assigned for a treatment consisting of the subcutaneous administration of placebo or 1, 0.5, or 0.1 mg NBI-6024 at baseline, weeks 2 and 4, and then monthly until month 24. Fasting, peak, and area under the curve (AUC) C-peptide concentrations during a 2-h mixed-meal tolerance test were measured at 3-month intervals during treatment. Immune function parameters (islet antibodies and CD4 and CD8 T-cells) were also studied. The mean peak C-peptide concentration at 24 months after study entry showed no significant difference between the groups treated with 0.1 mg (0.59 pmol/ml), 0.5 mg (0.57 pmol/ml), and 1.0 mg NBI-6024 (0.48 pmol/ml) and the placebo group (0.54 pmol/ml). Fasting, stimulated peak, and AUC C-peptide concentrations declined linearly in all groups by approximately 60% over the 24-month treatment period. The average daily insulin needs at month 24 were also comparable between the four groups. No treatment-related changes in islet antibodies and T cell numbers were observed. Treatment with altered peptide ligand NBI-6024 at repeated doses of 0.1, 0.5, or 1.0 mg did not improve or maintain beta-cell function.

Amino acid–insensitive mTORC1 regulation enables nutritional stress resilience in hematopoietic stem cells

PubMed Central

Kalaitzidis, Demetrios; Efeyan, Alejo; Kfoury, Youmna; Nayyar, Naema; Sykes, David B.; Mercier, Francois E.; Papazian, Ani; Baryawno, Ninib; Victora, Gabriel D.; Sabatini, David M.; Scadden, David T.

2017-01-01

The mTOR pathway is a critical determinant of cell persistence and growth wherein mTOR complex 1 (mTORC1) mediates a balance between growth factor stimuli and nutrient availability. Amino acids or glucose facilitates mTORC1 activation by inducing RagA GTPase recruitment of mTORC1 to the lysosomal outer surface, enabling activation of mTOR by the Ras homolog Rheb. Thereby, RagA alters mTORC1-driven growth in times of nutrient abundance or scarcity. Here, we have evaluated differential nutrient-sensing dependence through RagA and mTORC1 in hematopoietic progenitors, which dynamically drive mature cell production, and hematopoietic stem cells (HSC), which provide a quiescent cellular reserve. In nutrient-abundant conditions, RagA-deficient HSC were functionally unimpaired and upregulated mTORC1 via nutrient-insensitive mechanisms. RagA was also dispensable for HSC function under nutritional stress conditions. Similarly, hyperactivation of RagA did not affect HSC function. In contrast, RagA deficiency markedly altered progenitor population function and mature cell output. Therefore, RagA is a molecular mechanism that distinguishes the functional attributes of reactive progenitors from a reserve stem cell pool. The indifference of HSC to nutrient sensing through RagA contributes to their molecular resilience to nutritional stress, a characteristic that is relevant to organismal viability in evolution and in modern HSC transplantation approaches. PMID:28319048

Mesenchymal Stem and Progenitor Cells in Normal and Dysplastic Hematopoiesis—Masters of Survival and Clonality?

PubMed Central

Pleyer, Lisa; Valent, Peter; Greil, Richard

2016-01-01

Myelodysplastic syndromes (MDS) are malignant hematopoietic stem cell disorders that have the capacity to progress to acute myeloid leukemia (AML). Accumulating evidence suggests that the altered bone marrow (BM) microenvironment in general, and in particular the components of the stem cell niche, including mesenchymal stem cells (MSCs) and their progeny, play a pivotal role in the evolution and propagation of MDS. We here present an overview of the role of MSCs in the pathogenesis of MDS, with emphasis on cellular interactions in the BM microenvironment and related stem cell niche concepts. MSCs have potent immunomodulatory capacities and communicate with diverse immune cells, but also interact with various other cellular components of the microenvironment as well as with normal and leukemic stem and progenitor cells. Moreover, compared to normal MSCs, MSCs in MDS and AML often exhibit altered gene expression profiles, an aberrant phenotype, and abnormal functional properties. These alterations supposedly contribute to the “reprogramming” of the stem cell niche into a disease-permissive microenvironment where an altered immune system, abnormal stem cell niche interactions, and an impaired growth control lead to disease progression. The current article also reviews molecular targets that play a role in such cellular interactions and possibilities to interfere with abnormal stem cell niche interactions by using specific targeted drugs. PMID:27355944

Simulated microgravity, Mars gravity, and 2g hypergravity affect cell cycle regulation, ribosome biogenesis, and epigenetics in Arabidopsis cell cultures.

PubMed

Kamal, Khaled Y; Herranz, Raúl; van Loon, Jack J W A; Medina, F Javier

2018-04-23

Gravity is the only component of Earth environment that remained constant throughout the entire process of biological evolution. However, it is still unclear how gravity affects plant growth and development. In this study, an in vitro cell culture of Arabidopsis thaliana was exposed to different altered gravity conditions, namely simulated reduced gravity (simulated microgravity, simulated Mars gravity) and hypergravity (2g), to study changes in cell proliferation, cell growth, and epigenetics. The effects after 3, 14, and 24-hours of exposure were evaluated. The most relevant alterations were found in the 24-hour treatment, being more significant for simulated reduced gravity than hypergravity. Cell proliferation and growth were uncoupled under simulated reduced gravity, similarly, as found in meristematic cells from seedlings grown in real or simulated microgravity. The distribution of cell cycle phases was changed, as well as the levels and gene transcription of the tested cell cycle regulators. Ribosome biogenesis was decreased, according to levels and gene transcription of nucleolar proteins and the number of inactive nucleoli. Furthermore, we found alterations in the epigenetic modifications of chromatin. These results show that altered gravity effects include a serious disturbance of cell proliferation and growth, which are cellular functions essential for normal plant development.

Mesenchymal Stem and Progenitor Cells in Normal and Dysplastic Hematopoiesis-Masters of Survival and Clonality?

PubMed

Pleyer, Lisa; Valent, Peter; Greil, Richard

2016-06-27

Myelodysplastic syndromes (MDS) are malignant hematopoietic stem cell disorders that have the capacity to progress to acute myeloid leukemia (AML). Accumulating evidence suggests that the altered bone marrow (BM) microenvironment in general, and in particular the components of the stem cell niche, including mesenchymal stem cells (MSCs) and their progeny, play a pivotal role in the evolution and propagation of MDS. We here present an overview of the role of MSCs in the pathogenesis of MDS, with emphasis on cellular interactions in the BM microenvironment and related stem cell niche concepts. MSCs have potent immunomodulatory capacities and communicate with diverse immune cells, but also interact with various other cellular components of the microenvironment as well as with normal and leukemic stem and progenitor cells. Moreover, compared to normal MSCs, MSCs in MDS and AML often exhibit altered gene expression profiles, an aberrant phenotype, and abnormal functional properties. These alterations supposedly contribute to the "reprogramming" of the stem cell niche into a disease-permissive microenvironment where an altered immune system, abnormal stem cell niche interactions, and an impaired growth control lead to disease progression. The current article also reviews molecular targets that play a role in such cellular interactions and possibilities to interfere with abnormal stem cell niche interactions by using specific targeted drugs.

Transcriptional specificity in various p53-mutant cells.

PubMed

Okaichi, Kumio; Izumi, Nanaka; Takamura, Yuma; Fukui, Shoichi; Kudo, Takashi

2013-03-01

Mutation of the tumor suppressor gene p53 is the most common genetic alteration observed in human tumors. However, the relationship between the mutation point of p53 and the transcriptional specificity is not so obvious. We prepared Saos-2 cells with various mutations of p53 that are found in human tumors, and examined the resulting transcriptional alterations in the cells. Loss of function and gain of function were observed in all p53 mutants. Hot-spot mutations of p53 are frequently found in tumor cells. We compared hot-spot mutations and other mutations of p53 and found that a more than 2-fold transcription of CADPS2, PIWIL4 and TRIM9 was induced by hot spot mutations, but not by other mutations. As PIWIL4 suppresses the p16(INK4A) and ARF pathway, restraining cell growth and genomic instability, induction of PIWIL4 expression may be one reason why hot-spot mutations are frequently found in tumor cells.

The cancer glycocalyx mechanically primes integrin-mediated growth and survival

PubMed Central

Paszek, Matthew J.; DuFort, Christopher C.; Rossier, Olivier; Bainer, Russell; Mouw, Janna K.; Godula, Kamil; Hudak, Jason E.; Lakins, Jonathon N.; Wijekoon, Amanda C.; Cassereau, Luke; Rubashkin, Matthew G.; Magbanua, Mark J.; Thorn, Kurt S.; Davidson, Michael W.; Rugo, Hope S.; Park, John W.; Hammer, Daniel A.; Giannone, Grégory; Bertozzi, Carolyn R.; Weaver, Valerie M.

2015-01-01

Malignancy is associated with altered expression of glycans and glycoproteins that contribute to the cellular glycocalyx. We constructed a glycoprotein expression signature, which revealed that metastatic tumours upregulate expression of bulky glycoproteins. A computational model predicted that these glycoproteins would influence transmembrane receptor spatial organization and function. We tested this prediction by investigating whether bulky glycoproteins in the glycocalyx promote a tumour phenotype in human cells by increasing integrin adhesion and signalling. Our data revealed that a bulky glycocalyx facilitates integrin clustering by funnelling active integrins into adhesions and altering integrin state by applying tension to matrix-bound integrins, independent of actomyosin contractility. Expression of large tumour-associated glycoproteins in non-transformed mammary cells promoted focal adhesion assembly and facilitated integrin-dependent growth factor signalling to support cell growth and survival. Clinical studies revealed that large glycoproteins are abundantly expressed on circulating tumour cells from patients with advanced disease. Thus, a bulky glycocalyx is a feature of tumour cells that could foster metastasis by mechanically enhancing cell-surface receptor function. PMID:25030168

Mannan oligosaccharide requires functional ETC and TLR for biological radiation protection to normal cells.

PubMed

Sanguri, Sweta; Gupta, Damodar

2018-06-27

Low LET Ionizing radiation is known to alter intracellular redox balance by inducing free radical generation, which may cause oxidative modification of various cellular biomolecules. The extent of biomolecule-modifications/ damages and changes in vital processes (viz. cellular homeostasis, inter-/intra-cellular signaling, mitochondrial physiology/dynamics antioxidant defence systems) are crucial which in turn determine fate of cells. In the present study, we expended TLR expressing (normal/ transformed) and TLR null cells; and we have shown that mannan pretreatment in TLR expressing normal cells offers survival advantage against lethal doses of ionizing radiation. On the contrary, mannan pretreatment does not offer any protection against radiation to TLR null cells, NKE ρ° cells and transformed cells. In normal cells, abrupt decrease in mitochondrial membrane potential and endogenous ROS levels occurs following treatment with mannan. We intend to irradiate mannan-pretreated cells at a specific stage of perturbed mitochondrial functioning and ROS levels to comprehend if mannan pretreatment offers any survival advantage against radiation exposure to cells. Interestingly, pre-irradiation treatment of cells with mannan activates NFκB, p38 and JNK, alters mitochondrial physiology, increases expression of Cu/ZnSOD and MnSOD, minimizes oxidation of mitochondrial phospholipids and offers survival advantage in comparison to irradiated group, in TLR expressing normal cells. The study demonstrates that TLR and mitochondrial ETC functions are inevitable in radio-protective efficacy exhibited by mannan.

Calmodulin-Dependent Protein Kinase mediates Hypergravity-Induced Changes in F-Actin Expression by Endothelial Cells

NASA Technical Reports Server (NTRS)

Love, Felisha D.; Melhado, Caroline; Bosah, Francis; Harris-Hooker, Sandra A.; Sanford, Gary L.

1997-01-01

A number of basic cellular functions, e.g., electrolyte concentration cell growth rate, glucose utilization, bone formation, response to growth stimulation and exocytosis are modified by microgravity or during spaceflight. Studies with intact animal during spaceflights have found lipid accumulations within the lumen of the vasculature and degeneration of the vascular wall. Capillary alterations with extensive endothelial invaginations were also seen. Hemodynamic studies have shown that there is a redistribution of blood from the lower extremities to the upper part of the body; this will alter vascular permeability, resulting in leakage into surrounding tissues. These studies indicate that changes in gravity will affect a number of physiological systems, including the vasculature. However, few studies have addressed the effect of microgravity on vascular cell function and metabolism. A major problem with ground based studies is that achieving a true microgravity hand, environment for prolonged period is not possible. On the other increasing gravity (i.e., hypergravity) is easily achieved. Several researchers have shown that hypergravity will increase the proliferation of several different cell limes (e.g., chick embryo fibroblasts) while decreasing cell motility and slowing liver regeneration following partial hepatectomy. These studies suggest that hypergravity will alter the behavior of most cells. Several investigators have shown that hypergravity affects the expression of the early response genes (c-fos and c-myc) and the activation of several protein kinases (PK's) in cells (10,11). In this study we investigated whether hypergravity alters the expression of f-actin by aortic endothelial cells, and the possible role of protein kinases (calmodulin(II)-dependent and PKA) as mediators of these effects.

Microglia, the missing link in maternal immune activation and fetal neurodevelopment; and a possible link in preeclampsia and disturbed neurodevelopment?

PubMed

Prins, Jelmer R; Eskandar, Sharon; Eggen, Bart J L; Scherjon, Sicco A

2018-04-01

Disturbances in fetal neurodevelopment have extensively been related to neurodevelopmental disorders in early and later life. Fetal neurodevelopment is dependent on adequate functioning of the fetal immune system. During pregnancy, the maternal immune system is challenged to both tolerate the semi-allogenic fetus and to protect the mother and fetus from microbes. The fetal immune system is influenced by maternal immune disturbances; therefore, perturbations in maternal immunity likely do not only alter pregnancy outcome but also alter fetal neurodevelopment. A possible common pathway could be modulating the functioning of tissue macrophages in the placenta and brain. Maternal immune tolerance towards the fetus involves several complex adaptations. In this active maternal immune state, the fetus develops its own immunity. As cytokines and other players of the immune system -which can pass the placenta- are involved in neurodevelopment, disruptions in immune balance influence fetal neurodevelopment. Several studies reported an association between maternal immune activation, complications of pregnancy as preeclampsia, and altered neonatal neurodevelopment. A possible pathway involves dysfunctioning of microglia cells, the immune cells of the brain. Functionality of microglia cells during normal pregnancy is, however, poorly understood. The recent outbreak of ZIKA virus (ZKV), but also the literature on virus infections in general and its consequences on microglial cell function and fetal neurodevelopment show the devastating effects a virus infection during pregnancy can have. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Abnormal Epigenetic Regulation of Immune System during Aging.

PubMed

Jasiulionis, Miriam G

2018-01-01

Epigenetics refers to the study of mechanisms controlling the chromatin structure, which has fundamental role in the regulation of gene expression and genome stability. Epigenetic marks, such as DNA methylation and histone modifications, are established during embryonic development and epigenetic profiles are stably inherited during mitosis, ensuring cell differentiation and fate. Under the effect of intrinsic and extrinsic factors, such as metabolic profile, hormones, nutrition, drugs, smoke, and stress, epigenetic marks are actively modulated. In this sense, the lifestyle may affect significantly the epigenome, and as a result, the gene expression profile and cell function. Epigenetic alterations are a hallmark of aging and diseases, such as cancer. Among biological systems compromised with aging is the decline of immune response. Different regulators of immune response have their promoters and enhancers susceptible to the modulation by epigenetic marks, which is fundamental to the differentiation and function of immune cells. Consistent evidence has showed the regulation of innate immune cells, and T and B lymphocytes by epigenetic mechanisms. Therefore, age-dependent alterations in epigenetic marks may result in the decline of immune function and this might contribute to the increased incidence of diseases in old people. In order to maintain health, we need to better understand how to avoid epigenetic alterations related to immune aging. In this review, the contribution of epigenetic mechanisms to the loss of immune function during aging will be discussed, and the promise of new means of disease prevention and management will be pointed.

Antigen presenting cells (APCs) from thermally injured and/or septic rats modulate CD4+ T cell responses of naive rat.

PubMed

Fazal, Nadeem; Raziuddin, Syed; Khan, Mehdi; Al-Ghoul, Walid M

2006-01-01

Regulation of immune response is marked by complex interactions among the cells that recognize and present antigens. Antigen presenting cells (APCs), the antigen presenting cell component of the innate immune response plays an important role in effector CD4+ T cell response. Thermal injury and/or superimposed sepsis in rats' leads to suppressed CD4+ T cell functions. We investigated modulations of CD4+ T cell function by APCs (purified non-T cells) from thermally injured and/or septic rats. Rats were subjected to 30% total body surface area scald burn or exposed to 37 degrees C water (Sham burn) and sepsis was induced by cecal-ligation and puncture (CLP) method. At day 3 post-injury animals were sacrificed and CD4+ T cells and APCs from mesenteric lymph nodes (MLN) were obtained using magnetic microbead isolation procedure. APCs from injured rats were co-cultured with sham rat MLN CD4+ T cells and proliferative responses (thymidine incorporation), phenotypic changes (Flow cytometry), IL-2 production (ELISA) and CTLA-4 mRNA (RT-PCR) were determined in naive rat CD4+ T cells. The data indicate that APCs from thermally injured and/or septic rats when co-cultured with CD4+ T cells suppressed CD4+ T cell effector functions. This lack of CD4+ T cell activation was accompanied with altered co-stimulatory molecules, i.e., CD28 and/or CTLA-4 (CD152). In conclusion, our studies indicated that defective APCs from thermally injured and/or septic rats modulate CD4+ T cell functions via changes in co-stimulatory molecules expressed on naive CD4+ T cells. This altered APC: CD4+ T cell interaction leads to suppressed CD4+ T cell activation of healthy animals.

Plasma membrane lipid–protein interactions affect signaling processes in sterol-biosynthesis mutants in Arabidopsis thaliana

PubMed Central

Zauber, Henrik; Burgos, Asdrubal; Garapati, Prashanth; Schulze, Waltraud X.

2014-01-01

The plasma membrane is an important organelle providing structure, signaling and transport as major biological functions. Being composed of lipids and proteins with different physicochemical properties, the biological functions of membranes depend on specific protein–protein and protein–lipid interactions. Interactions of proteins with their specific sterol and lipid environment were shown to be important factors for protein recruitment into sub-compartmental structures of the plasma membrane. System-wide implications of altered endogenous sterol levels for membrane functions in living cells were not studied in higher plant cells. In particular, little is known how alterations in membrane sterol composition affect protein and lipid organization and interaction within membranes. Here, we conducted a comparative analysis of the plasma membrane protein and lipid composition in Arabidopsis sterol-biosynthesis mutants smt1 and ugt80A2;B1. smt1 shows general alterations in sterol composition while ugt80A2;B1 is significantly impaired in sterol glycosylation. By systematically analyzing different cellular fractions and combining proteomic with lipidomic data we were able to reveal contrasting alterations in lipid–protein interactions in both mutants, with resulting differential changes in plasma membrane signaling status. PMID:24672530

Ly49 Receptors: Innate and Adaptive Immune Paradigms

PubMed Central

Rahim, Mir Munir A.; Tu, Megan M.; Mahmoud, Ahmad Bakur; Wight, Andrew; Abou-Samra, Elias; Lima, Patricia D. A.; Makrigiannis, Andrew P.

2014-01-01

The Ly49 receptors are type II C-type lectin-like membrane glycoproteins encoded by a family of highly polymorphic and polygenic genes within the mouse natural killer (NK) gene complex. This gene family is designated Klra, and includes genes that encode both inhibitory and activating Ly49 receptors in mice. Ly49 receptors recognize class I major histocompatibility complex-I (MHC-I) and MHC-I-like proteins on normal as well as altered cells. Their functional homologs in humans are the killer cell immunoglobulin-like receptors, which recognize HLA class I molecules as ligands. Classically, Ly49 receptors are described as being expressed on both the developing and mature NK cells. The inhibitory Ly49 receptors are involved in NK cell education, a process in which NK cells acquire function and tolerance toward cells that express “self-MHC-I.” On the other hand, the activating Ly49 receptors recognize altered cells expressing activating ligands. New evidence shows a broader Ly49 expression pattern on both innate and adaptive immune cells. Ly49 receptors have been described on multiple NK cell subsets, such as uterine NK and memory NK cells, as well as NKT cells, dendritic cells, plasmacytoid dendritic cells, macrophages, neutrophils, and cells of the adaptive immune system, such as activated T cells and regulatory CD8+ T cells. In this review, we discuss the expression pattern and proposed functions of Ly49 receptors on various immune cells and their contribution to immunity. PMID:24765094

Virus Innexins induce alterations in insect cell and tissue function

USDA-ARS?s Scientific Manuscript database

Polydnaviruses are dsDNA viruses that induce immune and developmental alterations in their caterpillar hosts. Characterization of polydnavirus gene families and family members is necessary to understand mechanisms of pathology and evolution of these viruses, and may aid to elucidate the role of host...

Bioenergetic Insufficiencies Due to Metabolic Alterations Regulated by the Inhibitory Receptor PD-1 Are an Early Driver of CD8(+) T Cell Exhaustion.

PubMed

Bengsch, Bertram; Johnson, Andy L; Kurachi, Makoto; Odorizzi, Pamela M; Pauken, Kristen E; Attanasio, John; Stelekati, Erietta; McLane, Laura M; Paley, Michael A; Delgoffe, Greg M; Wherry, E John

2016-08-16

Dynamic reprogramming of metabolism is essential for T cell effector function and memory formation. However, the regulation of metabolism in exhausted CD8(+) T (Tex) cells is poorly understood. We found that during the first week of chronic lymphocytic choriomeningitis virus (LCMV) infection, before severe dysfunction develops, virus-specific CD8(+) T cells were already unable to match the bioenergetics of effector T cells generated during acute infection. Suppression of T cell bioenergetics involved restricted glucose uptake and use, despite persisting mechanistic target of rapamycin (mTOR) signaling and upregulation of many anabolic pathways. PD-1 regulated early glycolytic and mitochondrial alterations and repressed transcriptional coactivator PGC-1α. Improving bioenergetics by overexpression of PGC-1α enhanced function in developing Tex cells. Therapeutic reinvigoration by anti-PD-L1 reprogrammed metabolism in a subset of Tex cells. These data highlight a key metabolic control event early in exhaustion and suggest that manipulating glycolytic and mitochondrial metabolism might enhance checkpoint blockade outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

Infection of hematopoietic stem cells by Leishmania infantum increases erythropoiesis and alters the phenotypic and functional profiles of progeny.

PubMed

Carvalho-Gontijo, Raquel; Moreira, Diana Raquel; Resende, Mariana; Costa-Silva, Matheus Fernandes; Peruhype-Magalhães, Vanessa; Ribeiro, Cláudia Maria Franco; Ribeiro, Daniel Dias; Silvestre, Ricardo; Cordeiro-da-Silva, Anabela; Martins-Filho, Olindo Assis; Teixeira-Carvalho, Andréa

2018-04-01

Immunosuppression is a well-established risk factor for Visceral Leishmaniasis. Post-immunosuppression leishmaniasis is characterized by an increase of parasite burden, hematopoietic disorders and unusual clinical manifestations. Although there are many reports on bone marrow findings in VL, less is known about the relationship between parasite dynamics in this organ and the function of either hematopoietic stem cells and progenitor cells themselves. In the present study, we tackle these issues using a new approach of infecting human stem cells derived from bone marrow with L. infantum. Using this strategy, we show that human hematopoietic stem cells (hHSC) are able to phagocytize L. infantum promastigotes and release modulatory and pro-inflammatory cytokines, mainly TNF-α. Our results demonstrated that L. infantum infection in vitro enhances hematopoiesis, favoring the development of erythrocitic lineage through a mechanism yet unknown. Moreover, we found that L. infantum infection alters the phenotypic profile of the hematopoietic progeny; modifying the surface markers expression of differentiated cells. Thus, our study represents a rare opportunity to monitor the in vitro differentiation of human stem cells experimentally infected by L. infantum to better understand the consequences of the infection on phenotypic and functional profile of the cell progeny. Copyright © 2017. Published by Elsevier Inc.

Cell volume change through water efflux impacts cell stiffness and stem cell fate

PubMed Central

Pegoraro, Adrian F.; Mao, Angelo; Zhou, Enhua H.; Arany, Praveen R.; Han, Yulong; Burnette, Dylan T.; Jensen, Mikkel H.; Kasza, Karen E.; Moore, Jeffrey R.; Mackintosh, Frederick C.; Fredberg, Jeffrey J.; Mooney, David J.; Lippincott-Schwartz, Jennifer; Weitz, David A.

2017-01-01

Cells alter their mechanical properties in response to their local microenvironment; this plays a role in determining cell function and can even influence stem cell fate. Here, we identify a robust and unified relationship between cell stiffness and cell volume. As a cell spreads on a substrate, its volume decreases, while its stiffness concomitantly increases. We find that both cortical and cytoplasmic cell stiffness scale with volume for numerous perturbations, including varying substrate stiffness, cell spread area, and external osmotic pressure. The reduction of cell volume is a result of water efflux, which leads to a corresponding increase in intracellular molecular crowding. Furthermore, we find that changes in cell volume, and hence stiffness, alter stem-cell differentiation, regardless of the method by which these are induced. These observations reveal a surprising, previously unidentified relationship between cell stiffness and cell volume that strongly influences cell biology. PMID:28973866

Platform for combined analysis of functional and biomolecular phenotypes of the same cell.

PubMed

Kelbauskas, L; Ashili, S; Zeng, J; Rezaie, A; Lee, K; Derkach, D; Ueberroth, B; Gao, W; Paulson, T; Wang, H; Tian, Y; Smith, D; Reid, B; Meldrum, Deirdre R

2017-03-16

Functional and molecular cell-to-cell variability is pivotal at the cellular, tissue and whole-organism levels. Yet, the ultimate goal of directly correlating the function of the individual cell with its biomolecular profile remains elusive. We present a platform for integrated analysis of functional and transcriptional phenotypes in the same single cells. We investigated changes in the cellular respiration and gene expression diversity resulting from adaptation to repeated episodes of acute hypoxia in a premalignant progression model. We find differential, progression stage-specific alterations in phenotypic heterogeneity and identify cells with aberrant phenotypes. To our knowledge, this study is the first demonstration of an integrated approach to elucidate how heterogeneity at the transcriptional level manifests in the physiologic profile of individual cells in the context of disease progression.

Autophagy: controlling cell fate in rheumatic diseases.

PubMed

Rockel, Jason S; Kapoor, Mohit

2016-09-01

Autophagy, an endogenous process necessary for the turnover of organelles, maintains cellular homeostasis and directs cell fate. Alterations to the regulation of autophagy contribute to the progression of various rheumatic diseases, including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), osteoarthritis (OA) and systemic sclerosis (SSc). Implicit in the progression of these diseases are cell-type-specific responses to surrounding factors that alter autophagy: chondrocytes within articular cartilage show decreased autophagy in OA, leading to rapid cell death and cartilage degeneration; fibroblasts from patients with SSc have restricted autophagy, similar to that seen in aged dermal fibroblasts; fibroblast-like synoviocytes from RA joints show altered autophagy, which contributes to synovial hyperplasia; and dysregulation of autophagy in haematopoietic lineage cells alters their function and maturation in SLE. Various upstream mechanisms also contribute to these diseases by regulating autophagy as part of their signalling cascades. In this Review, we discuss the links between autophagy, immune responses, fibrosis and cellular fates as they relate to pathologies associated with rheumatic diseases. Therapies in clinical use, and in preclinical or clinical development, are also discussed in relation to their effects on autophagy in rheumatic diseases.

Variants of glycerol dehydrogenase having D-lactate dehydrogenase activity and uses thereof

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

Wang, Qingzhao; Shanmugam, Keelnatham T.; Ingram, Lonnie O'Neal

The present invention provides methods of designing and generating glycerol dehydrogenase (GlyDH) variants that have altered function as compared to a parent polypeptide. The present invention further provides nucleic acids encoding GlyDH polypeptide variants having altered function as compared to the parent polypeptide. Host cells comprising polynucleotides encoding GlyDH variants and methods of producing lactic acids are also provided in various aspects of the invention.

Chemotherapy-induced long-term alteration of executive functions and hippocampal cell proliferation: role of glucose as adjuvant.

PubMed

Dubois, M; Lapinte, N; Villier, V; Lecointre, C; Roy, V; Tonon, M-C; Gandolfo, P; Joly, F; Hilber, P; Castel, H

2014-04-01

In patients, cancer and treatments provoke cognitive impairments referred to "chemofog". Here a validated neurobehavioral animal model, the unique way to explore causal direct links between chemotherapy used in clinical practices and brain disorders, allowed investigation of the direct long-term impact of colo-rectal cancer chemotherapy on cognition and cerebral plasticity. Young and aged mice received three injections every 7 days during 2 weeks of 5-fluorouracil either alone (5-FU, 37.5 mg/kg) or in combination with oxaliplatin (3 mg/kg) or with glucose (5%). The long-term effects (from day 24 to day 60) of chemotherapy were tested on emotional reactivity, learning and memory, behavioral flexibility and hippocampal cell plasticity. 5-FU (in saline)-treated aged and also young mice exhibited specific altered cognitive flexibility and behavioral hyper-reactivity to novelty, whereas the combination 5-FU (in saline)/oxaliplatin (in glucose) did not provoke any cognitive dysfunction. We thus observed that glucose counteracted 5-FU-induced altered executive functions and hippocampal cell proliferation in vivo, and protected neural stem cells in vitro from toxicity of 5-FU or oxaliplatin. In conclusion, these data suggest that the lasting chemotherapy-induced selective impairment of executive functions, whatever the age, and associated with a reduced number of hippocampal proliferating cells, can be counteracted by co-administration with glucose. Copyright © 2013 Elsevier Ltd. All rights reserved.

In vitro model to study the effects of matrix stiffening on Ca2+ handling and myofilament function in isolated adult rat cardiomyocytes.

PubMed

van Deel, Elza D; Najafi, Aref; Fontoura, Dulce; Valent, Erik; Goebel, Max; Kardux, Kim; Falcão-Pires, Inês; van der Velden, Jolanda

2017-07-15

This paper describes a novel model that allows exploration of matrix-induced cardiomyocyte adaptations independent of the passive effect of matrix rigidity on cardiomyocyte function. Detachment of adult cardiomyocytes from the matrix enables the study of matrix effects on cell shortening, Ca 2+ handling and myofilament function. Cell shortening and Ca 2+ handling are altered in cardiomyocytes cultured for 24 h on a stiff matrix. Matrix stiffness-impaired cardiomyocyte contractility is reversed upon normalization of extracellular stiffness. Matrix stiffness-induced reduction in unloaded shortening is more pronounced in cardiomyocytes isolated from obese ZSF1 rats with heart failure with preserved ejection fraction compared to lean ZSF1 rats. Extracellular matrix (ECM) stiffening is a key element of cardiac disease. Increased rigidity of the ECM passively inhibits cardiac contraction, but if and how matrix stiffening also actively alters cardiomyocyte contractility is incompletely understood. In vitro models designed to study cardiomyocyte-matrix interaction lack the possibility to separate passive inhibition by a stiff matrix from active matrix-induced alterations of cardiomyocyte properties. Here we introduce a novel experimental model that allows exploration of cardiomyocyte functional alterations in response to matrix stiffening. Adult rat cardiomyocytes were cultured for 24 h on matrices of tuneable stiffness representing the healthy and the diseased heart and detached from their matrix before functional measurements. We demonstrate that matrix stiffening, independent of passive inhibition, reduces cell shortening and Ca 2+ handling but does not alter myofilament-generated force. Additionally, detachment of adult cultured cardiomyocytes allowed the transfer of cells from one matrix to another. This revealed that stiffness-induced cardiomyocyte changes are reversed when matrix stiffness is normalized. These matrix stiffness-induced changes in cardiomyocyte function could not be explained by adaptation in the microtubules. Additionally, cardiomyocytes isolated from stiff hearts of the obese ZSF1 rat model of heart failure with preserved ejection fraction show more pronounced reduction in unloaded shortening in response to matrix stiffening. Taken together, we introduce a method that allows evaluation of the influence of ECM properties on cardiomyocyte function separate from the passive inhibitory component of a stiff matrix. As such, it adds an important and physiologically relevant tool to investigate the functional consequences of cardiomyocyte-matrix interactions. © 2017 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

Nutritional effects on T-cell immunometabolism

PubMed Central

Cohen, Sivan; Danzaki, Keiko; MacIver, Nancie J.

2017-01-01

T cells are highly influenced by nutrient uptake from their environment, and changes in overall nutritional status, such as malnutrition or obesity, can result in altered T-cell metabolism and behavior. In states of severe malnutrition or starvation, T-cell survival, proliferation, and inflammatory cytokine production are all decreased, as is T-cell glucose uptake and metabolism. The altered T-cell function and metabolism seen in malnutrition is associated with altered adipokine levels, most particularly decreased leptin. Circulating leptin levels are low in malnutrition, and leptin has been shown to be a key link between nutrition and immunity. The current view is that leptin signaling is required to upregulate activated T-cell glucose metabolism and thereby fuel T-cell activation. In the setting of obesity, T cells have been found to have a key role in promoting the recruitment of inflammatory macrophages to adipose depots along with the production of inflammatory cytokines that promote the development of insulin resistance leading to diabetes. Deletion of T cells, key T-cell transcription factors, or pro-inflammatory T-cell cytokines prevents insulin resistance in obesity and underscores the importance of T cells in obesity-associated inflammation and metabolic disease. Altogether, T cells have a critical role in nutritional immunometabolism. PMID:28054344

Cosmos 2229 immunology study (Experiment K-8-07)

NASA Technical Reports Server (NTRS)

Sonnenfeld, Gerald

1993-01-01

The purpose of the current study was to further validate use of the rhesus monkey as a model for humans in future space flight testing. The areas of immunological importance examined in the Cosmos 2229 flight were represented by two sets of studies. The first set of studies determined the effect of space flight on the ability of bone marrow cells to respond to granulocyte/monocyte colony stimulating factor (GM-CSF). GM-CSF is an important regulator in the differentiation of bone marrow cells of both monocyte/macrophage and granulocyte lineages and any change in the ability of these cells to respond to GM-CSF can result in altered immune function. A second set of studies determined space flight effects on the expression of cell surface markers on both spleen and bone marrow cells. Immune cell markers included in this study were those for T-cell, B-cell, natural killer cell, and interleukin-2 populations. Variations from a normal cell population percentage, as represented by these markers, can be correlated with alterations in immunological function. Cells were stained with fluorescein-labelled antibodies directed against the appropriate antigens, and then analyzed using a flow cytometer.

ALTERATIONS IN DEVELOPMENT OF REPRODUCTIVE AND ENDOCRINE SYSTEMS OF WILDLIFE POPULATIONS EXPOSED TO ENDOCRINE-DISRUPTING CONTAMINANTS.

EPA Science Inventory

Wildlife and human populations are affected by contaminants in natural settings. This problem has been a growing concern over the last decade with the realization that various environmental chemicals can alter the development and functioning of endocrine organs, cells and target ...

Epigenetics of Peripheral B-Cell Differentiation and the Antibody Response

PubMed Central

Zan, Hong; Casali, Paolo

2015-01-01

Epigenetic modifications, such as histone post-translational modifications, DNA methylation, and alteration of gene expression by non-coding RNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), are heritable changes that are independent from the genomic DNA sequence. These regulate gene activities and, therefore, cellular functions. Epigenetic modifications act in concert with transcription factors and play critical roles in B cell development and differentiation, thereby modulating antibody responses to foreign- and self-antigens. Upon antigen encounter by mature B cells in the periphery, alterations of these lymphocytes epigenetic landscape are induced by the same stimuli that drive the antibody response. Such alterations instruct B cells to undergo immunoglobulin (Ig) class switch DNA recombination (CSR) and somatic hypermutation (SHM), as well as differentiation to memory B cells or long-lived plasma cells for the immune memory. Inducible histone modifications, together with DNA methylation and miRNAs modulate the transcriptome, particularly the expression of activation-induced cytidine deaminase, which is essential for CSR and SHM, and factors central to plasma cell differentiation, such as B lymphocyte-induced maturation protein-1. These inducible B cell-intrinsic epigenetic marks guide the maturation of antibody responses. Combinatorial histone modifications also function as histone codes to target CSR and, possibly, SHM machinery to the Ig loci by recruiting specific adaptors that can stabilize CSR/SHM factors. In addition, lncRNAs, such as recently reported lncRNA-CSR and an lncRNA generated through transcription of the S region that form G-quadruplex structures, are also important for CSR targeting. Epigenetic dysregulation in B cells, including the aberrant expression of non-coding RNAs and alterations of histone modifications and DNA methylation, can result in aberrant antibody responses to foreign antigens, such as those on microbial pathogens, and generation of pathogenic autoantibodies, IgE in allergic reactions, as well as B cell neoplasia. Epigenetic marks would be attractive targets for new therapeutics for autoimmune and allergic diseases, and B cell malignancies. PMID:26697022

Effects of Simulated Microgravity on the Expression Profile of Microrna in Human Lymphoblastoid Cells

NASA Astrophysics Data System (ADS)

Zhang, Ye; Wu, Honglu; Ramesh, Govindarajan; Rohde, Larry; Story, Michael; Mangala, Lingegowda

2012-07-01

EFFECTS OF SIMULATED MICROGRAVITY ON THE EXPRESSION PROFILE OF MICRORNA IN HUMAN LYMPHOBLASTOID CELLS Lingegowda S. Mangala1,2, Ye Zhang1,3, Zhenhua He2, Kamal Emami1, Govindarajan T. Ramesh4, Michael Story 5, Larry H. Rohde2, and Honglu Wu1 1 NASA Johnson Space Center, Houston, Texas, USA 2 University of Houston Clear Lake, Houston, Texas, USA 3 Wyle Integrated Science and Engineering Group, Houston, Texas, USA 4 Norfolk State University, Norfolk, VA, USA 5 University of Texas, Southwestern Medical Center, Dallas, Texas, USA This study explores the changes in expression of microRNA (miRNA) and related genes under simulated microgravity conditions. In comparison to static 1g, microgravity has been shown to alter global gene expression patterns and protein levels in cultured cells or animals. miRNA has recently emerged as an important regulator of gene expression, possibly regulating as many as one-third of all human genes. However, very little is known about the effect of altered gravity on miRNA expression. To test the hypothesis that the miRNA expression profile would be altered in zero gravity resulting in altered regulation of gene expression leading to metabolic or functional changes in cells, we cultured TK6 human lymphoblastoid cells in a High Aspect Ratio Vessel (HARV; bioreactor) for 72 h either in the rotating condition to model microgravity in space or in the static condition as a control. Expression of several miRNA was changed significantly in the simulated microgravity condition including miR-150, miR-34a, miR-423-5p, miR-22 and miR-141, miR-618 and miR-222. To confirm whether this altered miRNA expression correlates with gene expression and functional changes of the cells, we performed DNA microarray and validated the related genes using q-RT PCR. Network and pathway analysis of gene and miRNA expression profiles indicates that the regulation of cell communication and catalytic activities, as well as pathways involved in immune response_IL-15 signaling and NGF mediated NF-kB activation were significantly altered under the simulated microgravity condition.

Antarctic isolation: immune and viral studies

NASA Technical Reports Server (NTRS)

Tingate, T. R.; Lugg, D. J.; Muller, H. K.; Stowe, R. P.; Pierson, D. L.

1997-01-01

Stressful environmental conditions are a major determinant of immune reactivity. This effect is pronounced in Australian National Antarctic Research Expedition populations exposed to prolonged periods of isolation in the Antarctic. Alterations of T cell function, including depression of cutaneous delayed-type hypersensitivity responses and a peak 48.9% reduction of T cell proliferation to the mitogen phytohaemagglutinin, were documented during a 9-month period of isolation. T cell dysfunction was mediated by changes within the peripheral blood mononuclear cell compartment, including a paradoxical atypical monocytosis associated with altered production of inflammatory cytokines. There was a striking reduction in the production by peripheral blood mononuclear cells of the predominant pro-inflammatory monokine TNF-alpha and changes were also detected in the production of IL-1, IL-2, IL-6, IL-1ra and IL-10. Prolonged Antarctic isolation is also associated with altered latent herpesvirus homeostasis, including increased herpesvirus shedding and expansion of the polyclonal latent Epstein-Barr virus-infected B cell population. These findings have important long-term health implications.

The Study of Leukocyte Functions in a Rotating Wall Vessel

NASA Technical Reports Server (NTRS)

Trial, JoAnn

1998-01-01

The objective of this study was to investigate the behavior of leukocytes under free-fall conditions in a rotating wall vessel. In such a vessel, the tendency of a cell to fall in response to gravity is opposed by the rotation of the vessel and the culture medium within, keeping the cells in suspension without fluid shear. Previous reports indicated that such functions as lymphocyte migration through collagen matrix or monocyte cytokine secretion are altered under these conditions, and these changes correlate with similar functional defects of cultured cells seen during spaceflight.

Morphofunctional and signaling molecules overlap of the pineal gland and thymus: role and significance in aging.

PubMed

Paltsev, Michael A; Polyakova, Victoria O; Kvetnoy, Igor M; Anderson, George; Kvetnaia, Tatiana V; Linkova, Natalia S; Paltseva, Ekaterina M; Rubino, Rosa; De Cosmo, Salvatore; De Cata, Angelo; Mazzoccoli, Gianluigi

2016-03-15

Deficits in neuroendocrine-immune system functioning, including alterations in pineal and thymic glands, contribute to aging-associated diseases. This study looks at ageing-associated alterations in pineal and thymic gland functioning evaluating common signaling molecules present in both human and animal pinealocytes and thymocytes: endocrine cell markers (melatonin, serotonin, pCREB, AANAT, CGRP, VIP, chromogranin А); cell renovation markers (p53, AIF, Ki67), matrix metalloproteinases (MMP2, MMP9) and lymphocytes markers (CD4, CD5, CD8, CD20). Pineal melatonin is decreased, as is one of the melatonin pathway synthesis enzymes in the thymic gland. A further similarity is the increased MMPs levels evident over age in both glands. Significant differences are evident in cell renovation processes, which deteriorate more quickly in the aged thymus versus the pineal gland. Decreases in the number of pineal B-cells and thymic T-cells were also observed over aging. Collected data indicate that cellular involution of the pineal gland and thymus show many commonalities, but also significant changes in aging-associated proteins. It is proposed that such ageing-associated alterations in these two glands provide novel pharmaceutical targets for the wide array of medical conditions that are more likely to emerge over the course of ageing.

Morphofunctional and signaling molecules overlap of the pineal gland and thymus: role and significance in aging

PubMed Central

Paltsev, Michael A.; Polyakova, Victoria O.; Kvetnoy, Igor M.; Anderson, George; Kvetnaia, Tatiana V.; Linkova, Natalia S.; Paltseva, Ekaterina M.; Rubino, Rosa; De Cosmo, Salvatore; De Cata, Angelo; Mazzoccoli, Gianluigi

2016-01-01

Deficits in neuroendocrine-immune system functioning, including alterations in pineal and thymic glands, contribute to aging-associated diseases. This study looks at ageing-associated alterations in pineal and thymic gland functioning evaluating common signaling molecules present in both human and animal pinealocytes and thymocytes: endocrine cell markers (melatonin, serotonin, pCREB, AANAT, CGRP, VIP, chromogranin A); cell renovation markers (p53, AIF, Ki67), matrix metalloproteinases (MMP2, MMP9) and lymphocytes markers (CD4, CD5, CD8, CD20). Pineal melatonin is decreased, as is one of the melatonin pathway synthesis enzymes in the thymic gland. A further similarity is the increased MMPs levels evident over age in both glands. Significant differences are evident in cell renovation processes, which deteriorate more quickly in the aged thymus versus the pineal gland. Decreases in the number of pineal B-cells and thymic T-cells were also observed over aging. Collected data indicate that cellular involution of the pineal gland and thymus show many commonalities, but also significant changes in aging-associated proteins. It is proposed that such ageing-associated alterations in these two glands provide novel pharmaceutical targets for the wide array of medical conditions that are more likely to emerge over the course of ageing. PMID:26943046

Quantitative proteomic profiling of paired cancerous and normal colon epithelial cells isolated freshly from colorectal cancer patients.

PubMed

Tu, Chengjian; Mojica, Wilfrido; Straubinger, Robert M; Li, Jun; Shen, Shichen; Qu, Miao; Nie, Lei; Roberts, Rick; An, Bo; Qu, Jun

2017-05-01

The heterogeneous structure in tumor tissues from colorectal cancer (CRC) patients excludes an informative comparison between tumors and adjacent normal tissues. Here, we develop and apply a strategy to compare paired cancerous (CEC) versus normal (NEC) epithelial cells enriched from patients and discover potential biomarkers and therapeutic targets for CRC. CEC and NEC cells are respectively isolated from five different tumor and normal locations in the resected colon tissue from each patient (N = 12 patients) using an optimized epithelial cell adhesion molecule (EpCAM)-based enrichment approach. An ion current-based quantitative method is employed to perform comparative proteomic analysis for each patient. A total of 458 altered proteins that are common among >75% of patients are observed and selected for further investigation. Besides known findings such as deregulation of mitochondrial function, tricarboxylic acid cycle, and RNA post-transcriptional modification, functional analysis further revealed RAN signaling pathway, small nucleolar ribonucleoproteins (snoRNPs), and infection by RNA viruses are altered in CEC cells. A selection of the altered proteins of interest is validated by immunohistochemistry analyses. The informative comparison between matched CEC and NEC enhances our understanding of molecular mechanisms of CRC development and provides biomarker candidates and new pathways for therapeutic intervention. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An Iron-Regulated Autolysin Remodels the Cell Wall To Facilitate Heme Acquisition in Staphylococcus lugdunensis

PubMed Central

Farrand, Allison J.; Haley, Kathryn P.; Lareau, Nichole M.; Heilbronner, Simon; McLean, John A.; Foster, Timothy

2015-01-01

Bacteria alter their cell surface in response to changing environments, including those encountered upon invasion of a host during infection. One alteration that occurs in several Gram-positive pathogens is the presentation of cell wall-anchored components of the iron-regulated surface determinant (Isd) system, which extracts heme from host hemoglobin to fulfill the bacterial requirement for iron. Staphylococcus lugdunensis, an opportunistic pathogen that causes infective endocarditis, encodes an Isd system. Unique among the known Isd systems, S. lugdunensis contains a gene encoding a putative autolysin located adjacent to the Isd operon. To elucidate the function of this putative autolysin, here named IsdP, we investigated its contribution to Isd protein localization and hemoglobin-dependent iron acquisition. S. lugdunensis IsdP was found to be iron regulated and cotranscribed with the Isd operon. IsdP is a specialized peptidoglycan hydrolase that cleaves the stem peptide and pentaglycine crossbridge of the cell wall and alters processing and anchoring of a major Isd system component, IsdC. Perturbation of IsdC localization due to isdP inactivation results in a hemoglobin utilization growth defect. These studies establish IsdP as an autolysin that functions in heme acquisition and describe a role for IsdP in cell wall reorganization to accommodate nutrient uptake systems during infection. PMID:26123800

Critical role of intestinal epithelial cell-derived IL-25 in enteric nematode infection-induced changes in intestinal function

USDA-ARS?s Scientific Manuscript database

The current study investigated the mechanism of immune regulation of IL-25 and the contribution of IL-25 to nematode infection-induced alterations in intestinal smooth muscle and epithelial cell function. Mice were infected with an enteric nematode or injected with IL-25 or IL-13. In vitro smooth m...

Calcium signaling in plant cells in altered gravity

NASA Astrophysics Data System (ADS)

Kordyum, E. L.

2003-10-01

Changes in the intracellular Ca 2+ concentration in altered gravity (microgravity and clinostating) evidence that Ca 2+ signaling can play a fundamental role in biological effects of microgravity. Calcium as a second messenger is known to play a crucial role in stimulus - response coupling for many plant cellular signaling pathways. Its messenger functions are realized by transient changes in the cytosolic ion concentration induced by a variety of internal and external stimuli such as light, hormones, temperature, anoxia, salinity, and gravity. Although the first data on the changes in the calcium balance in plant cells under the influence of altered gravity have appeared in 80 th, a review highlighting the performed research and the possible significance of such Ca 2+ changes in the structural and metabolic rearrangements of plant cells in altered gravity is still lacking. In this paper, an attempt was made to summarize the available experimental results and to consider some hypotheses in this field of research. It is proposed to distinguish between cell gravisensing and cell graviperception; the former is related to cell structure and metabolism stability in the gravitational field and their changes in microgravity (cells not specialized to gravity perception), the latter is related to active use of a gravitational stimulus by cells presumebly specialized to gravity perception for realization of normal space orientation, growth, and vital activity (gravitropism, gravitaxis) in plants. The main experimental data concerning both redistribution of free Ca 2+ ions in plant cell organelles and the cell wall, and an increase in the intracellular Ca 2+ concentration under the influence of altered gravity are presented. Based on the gravitational decompensation hypothesis, the consequence of events occurring in gravisensing cells not specialized to gravity perception under altered gravity are considered in the following order: changes in the cytoplasmic membrane surface tension → alterations in the physicochemical properties of the membrane → changes in membrane permeability, ion transport, membrane-bound enzyme activity, etc. → metabolism rearrangements → physiological responses. An analysis of data available on biological effects of altered gravity at the cellular level allows one to conclude that microgravity environment appears to affect cytoskeleton, carbohydrate and lipid metabolism, cell wall biogenesis via changes in enzyme activity and protein expression, with involvement of regulatory Ca 2+ messenger system. Changes in Ca 2+ influx/efflux and possible pathways of Ca 2+ signaling in plant cell biochemical regulation in altered gravity are discussed.

7DHC-induced changes of Kv1.3 operation contributes to modified T cell function in Smith-Lemli-Opitz syndrome.

PubMed

Balajthy, András; Somodi, Sándor; Pethő, Zoltán; Péter, Mária; Varga, Zoltán; Szabó, Gabriella P; Paragh, György; Vígh, László; Panyi, György; Hajdu, Péter

2016-08-01

In vitro manipulation of membrane sterol level affects the regulation of ion channels and consequently certain cellular functions; however, a comprehensive study that confirms the pathophysiological significance of these results is missing. The malfunction of 7-dehydrocholesterol (7DHC) reductase in Smith-Lemli-Opitz syndrome (SLOS) leads to the elevation of the 7-dehydrocholesterol level in the plasma membrane. T lymphocytes were isolated from SLOS patients to assess the effect of the in vivo altered membrane sterol composition on the operation of the voltage-gated Kv1.3 channel and the ion channel-dependent mitogenic responses. We found that the kinetic and equilibrium parameters of Kv1.3 activation changed in SLOS cells. Identical changes in Kv1.3 operation were observed when control/healthy T cells were loaded with 7DHC. Removal of the putative sterol binding sites on Kv1.3 resulted in a phenotype that was not influenced by the elevation in membrane sterol level. Functional assays exhibited impaired activation and proliferation rate of T cells probably partially due to the modified Kv1.3 operation. We concluded that the altered membrane sterol composition hindered the operation of Kv1.3 as well as the ion channel-controlled T cell functions.

Post-Synthetic Defucosylation of AGP by Aspergillus nidulans α-1,2-Fucosidase Expressed in Arabidopsis Apoplast Induces Compensatory Upregulation of α-1,2-Fucosyltransferases.

PubMed

Pogorelko, Gennady V; Reem, Nathan T; Young, Zachary T; Chambers, Lauran; Zabotina, Olga A

2016-01-01

Cell walls are essential components of plant cells which perform a variety of important functions for the different cell types, tissues and organs of a plant. Besides mechanical function providing cell shape, cell walls participate in intercellular communication, defense during plant-microbe interactions, and plant growth. The plant cell wall consists predominantly of polysaccharides with the addition of structural glycoproteins, phenolic esters, minerals, lignin, and associated enzymes. Alterations in the cell wall composition created through either changes in biosynthesis of specific constituents or their post-synthetic modifications in the apoplast compromise cell wall integrity and frequently induce plant compensatory responses as a result of these alterations. Here we report that post-synthetic removal of fucose residues specifically from arabinogalactan proteins in the Arabidopsis plant cell wall induces differential expression of fucosyltransferases and leads to the root and hypocotyl elongation changes. These results demonstrate that the post-synthetic modification of cell wall components presents a valuable approach to investigate the potential signaling pathways induced during plant responses to such modifications that usually occur during plant development and stress responses.

c-MYC—Making Liver Sick: Role of c-MYC in Hepatic Cell Function, Homeostasis and Disease

PubMed Central

Zheng, Kang; Cubero, Francisco Javier; Nevzorova, Yulia A.

2017-01-01

Over 35 years ago, c-MYC, a highly pleiotropic transcription factor that regulates hepatic cell function, was identified. In recent years, a considerable increment in the number of publications has significantly shifted the way that the c-MYC function is perceived. Overexpression of c-MYC alters a wide range of roles including cell proliferation, growth, metabolism, DNA replication, cell cycle progression, cell adhesion and differentiation. The purpose of this review is to broaden the understanding of the general functions of c-MYC, to focus on c-MYC-driven pathogenesis in the liver, explain its mode of action under basal conditions and during disease, and discuss efforts to target c-MYC as a plausible therapy for liver disease. PMID:28422055

Defective thymic progenitor development and mature T-cell responses in a mouse model for Down syndrome

PubMed Central

Lorenzo, Laureanne P E; Shatynski, Kristen E; Clark, Sarah; Yarowsky, Paul J; Williams, Mark S

2013-01-01

In addition to archetypal cognitive defects, Down syndrome (DS) is characterized by altered lymphocyte development and function, including premature thymic involution and increased incidence of infections. However, the potential mechanisms for these changes have not been fully elucidated. The current study used the Ts65Dn mouse model of DS to assess deficiencies in T-cell development and possible molecular alterations. Ts65Dn mice exhibited premature thymic involution and a threefold to fourfold decrease in the number and proportion of immature, double-negative thymocyte progenitors. In addition, there were twofold fewer double-positive and CD4 single-positive thymocytes in Ts65Dn thymuses. Reflecting this deficient thymic function, there were fewer naive T cells in the spleen and polyclonal stimulation of peripheral T cells exhibited a marked reduction in proliferation, suggesting a senescent phenotype. In contrast, B-cell progenitors were unchanged in the bone marrow of Ts65Dn mice, but in the spleen, there were decreased transitional and follicular B cells and these cells proliferated less upon antigen receptor stimulus but not in response to lipopolysaccharide. As a potential mechanism for diminished thymic function, immature thymocyte populations expressed diminished levels of the cytokine receptor interleukin-7Rα, which was associated with decreased proliferation and increased apoptosis. Increased oxidative stress and inhibition of the Notch pathway were identified as possible mediators of decreased interleukin-7Rα expression in Ts65Dn mice. The data suggest that immature thymocyte defects underlie immune dysfunction in DS and that increased oxidative stress and reduced cytokine signalling may alter lymphocyte development in Ts65Dn mice. PMID:23432468

Molecular analysis of urothelial cancer cell lines for modeling tumor biology and drug response.

PubMed

Nickerson, M L; Witte, N; Im, K M; Turan, S; Owens, C; Misner, K; Tsang, S X; Cai, Z; Wu, S; Dean, M; Costello, J C; Theodorescu, D

2017-01-05

The utility of tumor-derived cell lines is dependent on their ability to recapitulate underlying genomic aberrations and primary tumor biology. Here, we sequenced the exomes of 25 bladder cancer (BCa) cell lines and compared mutations, copy number alterations (CNAs), gene expression and drug response to BCa patient profiles in The Cancer Genome Atlas (TCGA). We observed a mutation pattern associated with altered CpGs and APOBEC-family cytosine deaminases similar to mutation signatures derived from somatic alterations in muscle-invasive (MI) primary tumors, highlighting a major mechanism(s) contributing to cancer-associated alterations in the BCa cell line exomes. Non-silent sequence alterations were confirmed in 76 cancer-associated genes, including mutations that likely activate oncogenes TERT and PIK3CA, and alter chromatin-associated proteins (MLL3, ARID1A, CHD6 and KDM6A) and established BCa genes (TP53, RB1, CDKN2A and TSC1). We identified alterations in signaling pathways and proteins with related functions, including the PI3K/mTOR pathway, altered in 60% of lines; BRCA DNA repair, 44%; and SYNE1-SYNE2, 60%. Homozygous deletions of chromosome 9p21 are known to target the cell cycle regulators CDKN2A and CDKN2B. This loci was commonly lost in BCa cell lines and we show the deletions extended to the polyamine enzyme methylthioadenosine (MTA) phosphorylase (MTAP) in 36% of lines, transcription factor DMRTA1 (27%) and antiviral interferon epsilon (IFNE, 19%). Overall, the BCa cell line genomic aberrations were concordant with those found in BCa patient tumors. We used gene expression and copy number data to infer pathway activities for cell lines, then used the inferred pathway activities to build a predictive model of cisplatin response. When applied to platinum-treated patients gathered from TCGA, the model predicted treatment-specific response. Together, these data and analysis represent a valuable community resource to model basic tumor biology and to study the pharmacogenomics of BCa.

Hematological alterations and thymic function in newborns of HIV-infected mothers receiving antiretroviral drugs.

PubMed

Wongnoi, Rotjanee; Penvieng, Nawaporn; Singboottra, Panthong; Kingkeow, Doungnapa; Oberdorfer, Peninnah; Sirivatanapa, Pannee; Pornprasert, Sakorn

2013-06-08

To investigate the effects of antiretroviral (ARV) drugs on hematological parameters and thymic function in HIV-uninfected newborns of HIV-infected mothers. Cross sectional study. Chiang-Mai University Hospital, Chiang-Mai, Thailand. 49 HIV-uninfected and 26 HIV-infected pregnancies. Cord blood samples of newborns from HIV-uninfected and HIV-infected mothers were collected. Hematological parameters were measured using automatic blood cell count. T-cell receptor excision circles (TRECs) levels in cord blood mononuclear cells (CBMCs), CD4+ and CD8+ T-cells were quantified using real-time PCR.. Hemotological parameters and thymic function. Newborn of HIV-infected mother tended to have lower mean levels of hemoglobin than those of HIV-uninfected mother (137 ±22 vs 146 ±17 g/L, P = 0.05). Furthermore, mean of red blood cell (RBC) counts and hematocrit and median of TRECs in CD4+ T-cells in the newborns of the former were significantly lower than those of the latter [3.6 ±0.7 vs 4.8 ±0.6 x 1012 cells/L, P <0.001; 0.40 ±0.07 vs 0.46 ±0.05 L/L, P < 0.001 and 0.53 (IQR: 0.03-5.76) vs 13.20 (IQR: 2.77-27.51) x 10-3 pg/uL, P = 0.02, respectively]. ARV drugs altered hematological parameters and thymic function (TRECs CD4+ T-cells) in HIV-uninfected newborns of HIV-infected mothers.

Neuroimmune regulation of neurophysiology in the cerebellum.

PubMed

Gruol, Donna L

2013-06-01

Recent studies have established the existence of an innate immune system in the central nervous system (CNS) and implicated a critical role for this system in both normal and pathological processes. Astrocytes and microglia, normal components of the CNS, are the primary cell types that comprise the innate immune system of the CNS. Basic to their role during normal and adverse conditions is the production of neuroimmune factors such as cytokines and chemokines, which are signaling molecules that initiate or coordinate downstream cellular actions. During adverse conditions, cytokines and chemokines function in defensive and repair. However, if expression of these factors becomes dysregulated, abnormal CNS function can result. Both neurons and glial cells of the CNS express receptors for cytokines and chemokines, but the biological consequence of receptor activation has yet to be fully resolved. Our studies show that neuroadaptive changes are produced in primary cultures of rat cerebellar cells chronically treated with the cytokine interleukin-6 (IL-6) and in the cerebellum of transgenic mice that chronically express elevated levels of IL-6 in the CNS. In the cerebellum in culture and in vivo, the neuroadaptive changes included alterations in the level of expression of proteins involved in gene expression, signal transduction, and synaptic transmission. Associated with these changes were alterations in neuronal function. A comparison of results from the cultured cerebellar cells and cerebellum of the transgenic mice indicated that the effects of IL-6 can vary across neuronal types. However, alterations in mechanisms involved in Ca(2+) homeostasis were observed in all cell types studied. These results indicate that modifications in cerebellar function are likely to occur in disorders associated with elevated levels of IL-6 in the cerebellum.

Programming Cell Adhesion for On-Chip Sequential Boolean Logic Functions.

PubMed

Qu, Xiangmeng; Wang, Shaopeng; Ge, Zhilei; Wang, Jianbang; Yao, Guangbao; Li, Jiang; Zuo, Xiaolei; Shi, Jiye; Song, Shiping; Wang, Lihua; Li, Li; Pei, Hao; Fan, Chunhai

2017-08-02

Programmable remodelling of cell surfaces enables high-precision regulation of cell behavior. In this work, we developed in vitro constructed DNA-based chemical reaction networks (CRNs) to program on-chip cell adhesion. We found that the RGD-functionalized DNA CRNs are entirely noninvasive when interfaced with the fluidic mosaic membrane of living cells. DNA toehold with different lengths could tunably alter the release kinetics of cells, which shows rapid release in minutes with the use of a 6-base toehold. We further demonstrated the realization of Boolean logic functions by using DNA strand displacement reactions, which include multi-input and sequential cell logic gates (AND, OR, XOR, and AND-OR). This study provides a highly generic tool for self-organization of biological systems.

Mutational analysis of the glycosylphosphatidylinositol (GPI) anchor pathway demonstrates that GPI-anchored proteins are required for cell wall biogenesis and normal hyphal growth in Neurospora crassa.

PubMed

Bowman, Shaun M; Piwowar, Amy; Al Dabbous, Mash'el; Vierula, John; Free, Stephen J

2006-03-01

Using mutational and proteomic approaches, we have demonstrated the importance of the glycosylphosphatidylinositol (GPI) anchor pathway for cell wall synthesis and integrity and for the overall morphology of the filamentous fungus Neurospora crassa. Mutants affected in the gpig-1, gpip-1, gpip-2, gpip-3, and gpit-1 genes, which encode components of the N. crassa GPI anchor biosynthetic pathway, have been characterized. GPI anchor mutants exhibit colonial morphologies, significantly reduced rates of growth, altered hyphal growth patterns, considerable cellular lysis, and an abnormal "cell-within-a-cell" phenotype. The mutants are deficient in the production of GPI-anchored proteins, verifying the requirement of each altered gene for the process of GPI-anchoring. The mutant cell walls are abnormally weak, contain reduced amounts of protein, and have an altered carbohydrate composition. The mutant cell walls lack a number of GPI-anchored proteins, putatively involved in cell wall biogenesis and remodeling. From these studies, we conclude that the GPI anchor pathway is critical for proper cell wall structure and function in N. crassa.

Functional and molecular alterations in T Cells induced by CCL5.

PubMed

Cridge, T J; Horowitz, K M; Marinucci, M N; Rose, K M; Wells, M; Werner, M T; Kurt, Robert A

2006-01-01

To delineate whether, and the extent to which, CCL5 could impact T cell function we examined cytokine production and proliferative ability following CCL5 treatment in vitro. We report a decreased ability of splenic T cells to produce IFN-? and TNF-a as well as proliferate in response to crosslinking with antibody to CD3 after 72, but not 24 hours of CCL5 exposure. To identify a mechanism by which CCL5 modulated T cell function, we examined T cell receptor translocation and lipid raft clustering. After exposure to CCL5, T cells were less efficient at translocating the TCR and clustering lipid rafts. Since TCR translocation and lipid raft clustering are required for creation of an immunological synapse, these data suggest that extended exposure to CCL5 may impact T cell effector function by modulating the ability to create a functional immunological synapse.

Proteomic profiling of epileptogenesis in a rat model: Focus on cell stress, extracellular matrix and angiogenesis.

PubMed

Keck, Michael; van Dijk, Roelof Maarten; Deeg, Cornelia A; Kistler, Katharina; Walker, Andreas; von Rüden, Eva-Lotta; Russmann, Vera; Hauck, Stefanie M; Potschka, Heidrun

2018-04-01

Information about epileptogenesis-associated changes in protein expression patterns is of particular interest for future selection of target and biomarker candidates. Bioinformatic analysis of proteomic data sets can increase our knowledge about molecular alterations characterizing the different phases of epilepsy development following an initial epileptogenic insult. Here, we report findings from a focused analysis of proteomic data obtained for the hippocampus and parahippocampal cortex samples collected during the early post-insult phase, latency phase, and chronic phase of a rat model of epileptogenesis. The study focused on proteins functionally associated with cell stress, cell death, extracellular matrix (ECM) remodeling, cell-ECM interaction, cell-cell interaction, angiogenesis, and blood-brain barrier function. The analysis revealed prominent pathway enrichment providing information about the complex expression alterations of the respective protein groups. In the hippocampus, the number of differentially expressed proteins declined over time during the course of epileptogenesis. In contrast, a peak in the regulation of proteins linked with cell stress and death as well as ECM and cell-cell interaction became evident at later phases during epileptogenesis in the parahippocampal cortex. The data sets provide valuable information about the time course of protein expression patterns during epileptogenesis for a series of proteins. Moreover, the findings provide comprehensive novel information about expression alterations of proteins that have not been discussed yet in the context of epileptogenesis. These for instance include different members of the lamin protein family as well as the fermitin family member 2 (FERMT2). Induction of FERMT2 and other selected proteins, CD18 (ITGB2), CD44 and Nucleolin were confirmed by immunohistochemistry. Taken together, focused bioinformatic analysis of the proteomic data sets completes our knowledge about molecular alterations linked with cell death and cellular plasticity during epileptogenesis. The analysis provided can guide future selection of target and biomarker candidates. Copyright © 2018 Elsevier Inc. All rights reserved.

Quantitative proteomic analysis of cultured skin fibroblast cells derived from patients with triglyceride deposit cardiomyovasculopathy

PubMed Central

2013-01-01

Background Triglyceride deposit cardiomyovasculopathy (TGCV) is a rare disease, characterized by the massive accumulation of triglyceride (TG) in multiple tissues, especially skeletal muscle, heart muscle and the coronary artery. TGCV is caused by mutation of adipose triglyceride lipase, which is an essential molecule for the hydrolysis of TG. TGCV is at high risk for skeletal myopathy and heart dysfunction, and therefore premature death. Development of therapeutic methods for TGCV is highly desirable. This study aims to discover specific molecules responsible for TGCV pathogenesis. Methods To identify differentially expressed proteins in TGCV patient cells, the stable isotope labeling with amino acids in cell culture (SILAC) method coupled with LC-MS/MS was performed using skin fibroblast cells derived from two TGCV patients and three healthy volunteers. Altered protein expression in TGCV cells was confirmed using the selected reaction monitoring (SRM) method. Microarray-based transcriptome analysis was simultaneously performed to identify changes in gene expression in TGCV cells. Results Using SILAC proteomics, 4033 proteins were quantified, 53 of which showed significantly altered expression in both TGCV patient cells. Twenty altered proteins were chosen and confirmed using SRM. SRM analysis successfully quantified 14 proteins, 13 of which showed the same trend as SILAC proteomics. The altered protein expression data set was used in Ingenuity Pathway Analysis (IPA), and significant networks were identified. Several of these proteins have been previously implicated in lipid metabolism, while others represent new therapeutic targets or markers for TGCV. Microarray analysis quantified 20743 transcripts, and 252 genes showed significantly altered expression in both TGCV patient cells. Ten altered genes were chosen, 9 of which were successfully confirmed using quantitative RT-PCR. Biological networks of altered genes were analyzed using an IPA search. Conclusions We performed the SILAC- and SRM-based identification-through-confirmation study using skin fibroblast cells derived from TGCV patients, and first identified altered proteins specific for TGCV. Microarray analysis also identified changes in gene expression. The functional networks of the altered proteins and genes are discussed. Our findings will be exploited to elucidate the pathogenesis of TGCV and discover clinically relevant molecules for TGCV in the near future. PMID:24360150

Characterisation of cell functions and receptors in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME).

PubMed

Hardcastle, Sharni Lee; Brenu, Ekua Weba; Johnston, Samantha; Nguyen, Thao; Huth, Teilah; Wong, Naomi; Ramos, Sandra; Staines, Donald; Marshall-Gradisnik, Sonya

2015-06-02

Abnormal immune function is often an underlying component of illness pathophysiology and symptom presentation. Functional and phenotypic immune-related alterations may play a role in the obscure pathomechanism of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME). The objective of this study was to investigate the functional ability of innate and adaptive immune cells in moderate and severe CFS/ME patients. The 1994 Fukuda criteria for CFS/ME were used to define CFS/ME patients. CFS/ME participants were grouped based on illness severity with 15 moderately affected (moderate) and 12 severely affected (severe) CFS/ME patients who were age and sex matched with 18 healthy controls. Flow cytometric protocols were used for immunological analysis of dendritic cells, monocytes and neutrophil function as well as measures of lytic proteins and T, natural killer (NK) and B cell receptors. CFS/ME patients exhibited alterations in NK receptors and adhesion markers and receptors on CD4(+)T and CD8(+)T cells. Moderate CFS/ME patients had increased CD8(+) CD45RA effector memory T cells, SLAM expression on NK cells, KIR2DL5(+) on CD4(+)T cells and BTLA4(+) on CD4(+)T central memory cells. Moderate CFS/ME patients also had reduced CD8(+)T central memory LFA-1, total CD8(+)T KLRG1, naïve CD4(+)T KLRG1 and CD56(dim)CD16(-) NK cell CD2(+) and CD18(+)CD2(+). Severe CFS/ME patients had increased CD18(+)CD11c(-) in the CD56(dim)CD16(-) NK cell phenotype and reduced NKp46 in CD56(bright)CD16(dim) NK cells. This research accentuated the presence of immunological abnormalities in CFS/ME and highlighted the importance of assessing functional parameters of both innate and adaptive immune systems in the illness.

Investigating the role of retinal Müller cells with approaches in genetics and cell biology.

PubMed

Fu, Suhua; Zhu, Meili; Ash, John D; Wang, Yunchang; Le, Yun-Zheng

2014-01-01

Müller cells are major macroglia and play many essential roles as a supporting cell in the retina. As Müller cells only constitute a small portion of retinal cells, investigating the role of Müller glia in retinal biology and diseases is particularly challenging. To overcome this problem, we first generated a Cre/lox-based conditional gene targeting system that permits the genetic manipulation and functional dissection of gene of interests in Müller cells. To investigate diabetes-induced alteration of Müller cells, we recently adopted methods to analyze Müller cells survival/death in vitro and in vivo. We also used normal and genetically altered primary cell cultures to reveal the mechanistic insights for Müller cells in biological and disease processes. In this article, we will discuss the applications and limitations of these methodologies, which may be useful for research in retinal Müller cell biology and pathophysiology.

Telomerase and drug resistance in cancer.

PubMed

Lipinska, Natalia; Romaniuk, Aleksandra; Paszel-Jaworska, Anna; Toton, Ewa; Kopczynski, Przemyslaw; Rubis, Blazej

2017-11-01

It is well known that a decreased expression or inhibited activity of telomerase in cancer cells is accompanied by an increased sensitivity to some drugs (e.g., doxorubicin, cisplatin, or 5-fluorouracil). However, the mechanism of the resistance resulting from telomerase alteration remains elusive. There are theories claiming that it might be associated with telomere shortening, genome instability, hTERT translocation, mitochondria functioning modulation, or even alterations in ABC family gene expression. However, association of those mechanisms, i.e., drug resistance and telomerase alterations, is not fully understood yet. We review the current theories on the aspect of the role of telomerase in cancer cells resistance to therapy. We believe that revealing/unravelling this correlation might significantly contribute to an increased efficiency of cancer cells elimination, especially the most difficult ones, i.e., drug resistant.

Alterations in the adenosine metabolism and CD39/CD73 adenosinergic machinery cause loss of Treg cell function and autoimmunity in ADA-deficient SCID.

PubMed

Sauer, Aisha V; Brigida, Immacolata; Carriglio, Nicola; Hernandez, Raisa Jofra; Scaramuzza, Samantha; Clavenna, Daniela; Sanvito, Francesca; Poliani, Pietro L; Gagliani, Nicola; Carlucci, Filippo; Tabucchi, Antonella; Roncarolo, Maria Grazia; Traggiai, Elisabetta; Villa, Anna; Aiuti, Alessandro

2012-02-09

Adenosine acts as anti-inflammatory mediator on the immune system and has been described in regulatory T cell (Treg)-mediated suppression. In the absence of adenosine deaminase (ADA), adenosine and other purine metabolites accumulate, leading to severe immunodeficiency with recurrent infections (ADA-SCID). Particularly ADA-deficient patients with late-onset forms and after enzyme replacement therapy (PEG-ADA) are known to manifest immune dysregulation. Herein we provide evidence that alterations in the purine metabolism interfere with Treg function, thereby contributing to autoimmune manifestations in ADA deficiency. Tregs isolated from PEG-ADA-treated patients are reduced in number and show decreased suppressive activity, whereas they are corrected after gene therapy. Untreated murine ADA(-/-) Tregs show alterations in the plasma membrane CD39/CD73 ectonucleotidase machinery and limited suppressive activity via extracellular adenosine. PEG-ADA-treated mice developed multiple autoantibodies and hypothyroidism in contrast to mice treated with bone marrow transplantation or gene therapy. Tregs isolated from PEG-ADA-treated mice lacked suppressive activity, suggesting that this treatment interferes with Treg functionality. The alterations in the CD39/CD73 adenosinergic machinery and loss of function in ADA-deficient Tregs provide new insights into a predisposition to autoimmunity and the underlying mechanisms causing defective peripheral tolerance in ADA-SCID.

Mitochondria: more than just a powerhouse.

PubMed

McBride, Heidi M; Neuspiel, Margaret; Wasiak, Sylwia

2006-07-25

Pioneering biochemical studies have long forged the concept that the mitochondria are the 'energy powerhouse of the cell'. These studies, combined with the unique evolutionary origin of the mitochondria, led the way to decades of research focusing on the organelle as an essential, yet independent, functional component of the cell. Recently, however, our conceptual view of this isolated organelle has been profoundly altered with the discovery that mitochondria function within an integrated reticulum that is continually remodeled by both fusion and fission events. The identification of a number of proteins that regulate these activities is beginning to provide mechanistic details of mitochondrial membrane remodeling. However, the broader question remains regarding the underlying purpose of mitochondrial dynamics and the translation of these morphological transitions into altered functional output. One hypothesis has been that mitochondrial respiration and metabolism may be spatially and temporally regulated by the architecture and positioning of the organelle. Recent evidence supports and expands this idea by demonstrating that mitochondria are an integral part of multiple cell signaling cascades. Interestingly, proteins such as GTPases, kinases and phosphatases are involved in bi-directional communication between the mitochondrial reticulum and the rest of the cell. These proteins link mitochondrial function and dynamics to the regulation of metabolism, cell-cycle control, development, antiviral responses and cell death. In this review we will highlight the emerging evidence that provides molecular definition to mitochondria as a central platform in the execution of diverse cellular events.

Analysis of pulmonary surfactant by Fourier-transform infrared spectroscopy following exposure to Stachybotrys chartarum (atra) spores.

PubMed

McCrae, K C; Rand, T; Shaw, R A; Mason, C; Oulton, M R; Hastings, C; Cherlet, T; Thliveris, J A; Mantsch, H H; MacDonald, J; Scott, J E

2001-03-01

Lung cells are among the first tissues of the body to be exposed to air-borne environmental contaminants. Consequently the function of these cells may be altered before other cells are affected. As gas exchange takes place in the lungs, changes in cellular function may have serious implications for the processes of oxygen uptake and carbon dioxide elimination. In order for these processes to occur, the lung must maintain a high degree of expandability. This latter function is accomplished in part by the pulmonary surfactant which is synthesized and released by alveolar type II cells. Earlier studies have shown that exposure to gas phase materials such as smoke or organic solvents can alter the composition and function of the surfactant. The present study examines the ability of highly toxigenic mold spores to alter surfactant composition. Stachybotrys chartarum spores suspended in saline were instilled into mouse trachea as described earlier. After 24 h, the lungs were lavaged and the different processing stages of surfactant isolated by repeated centrifugation. Intracellular surfactant was isolated from the homogenized lung tissue by centrifugation on a discontinuous sucrose gradient. Samples were extracted into chloroform-methanol, dried and analyzed by Fourier-Transform infrared spectroscopy (FTIR). Exposure to S. chartarum induced an overall reduction of phospholipid among the three surfactant subfractions. The intermediate and spent surfactant fractions in particular were reduced to about half of the values observed in the saline-treated group. The relative distribution of phospholipid was also altered by spore exposure. Within the intracellular surfactant pool, higher levels of phospholipid were detected after spore exposure. In addition, changes were observed in the nature of the phospholipids. In particular strong intramolecular hydrogen bonding, together with other changes, suggested that spore exposure was associated with absence of an acyl chain esterified on the glycerol backbone, resulting in elevated levels of lysophospholipid in the samples. This study shows that mold spores and their products induce changes in regulation of both secretion and synthesis of surfactant, as well as alterations in the pattern of phospholipid targeting to the pulmonary surfactant pools.

Manganese-Induced Neurotoxicity and Alterations in Gene Expression in Human Neuroblastoma SH-SY5Y Cells.

PubMed

Gandhi, Deepa; Sivanesan, Saravanadevi; Kannan, Krishnamurthi

2018-06-01

Manganese (Mn) is an essential trace element required for many physiological functions including proper biochemical and cellular functioning of the central nervous system (CNS). However, exposure to excess level of Mn through occupational settings or from environmental sources has been associated with neurotoxicity. The cellular and molecular mechanism of Mn-induced neurotoxicity remains unclear. In the current study, we investigated the effects of 30-day exposure to a sub-lethal concentration of Mn (100 μM) in human neuroblastoma cells (SH-SY5Y) using transcriptomic approach. Microarray analysis revealed differential expression of 1057 transcripts in Mn-exposed SH-SY5Y cells as compared to control cells. Gene functional annotation cluster analysis exhibited that the differentially expressed genes were associated with several biological pathways. Specifically, genes involved in neuronal pathways including neuron differentiation and development, regulation of neurogenesis, synaptic transmission, and neuronal cell death (apoptosis) were found to be significantly altered. KEGG pathway analysis showed upregulation of p53 signaling pathways and neuroactive ligand-receptor interaction pathways, and downregulation of neurotrophin signaling pathway. On the basis of the gene expression profile, possible molecular mechanisms underlying Mn-induced neuronal toxicity were predicted.

N-(3-oxododecanoyl)-l-homoserine lactone modulates mitochondrial function and suppresses proliferation in intestinal goblet cells.

PubMed

Tao, Shiyu; Niu, Liqiong; Cai, Liuping; Geng, Yali; Hua, Canfeng; Ni, Yingdong; Zhao, Ruqian

2018-05-15

The quorum-sensing molecule N‑(3‑oxododecanoyl)‑l‑homoserine lactone (C12-HSL), produced by the Gram negative human pathogenic bacterium Pseudomonas aeruginosa, modulates mammalian cell behavior. Our previous findings suggested that C12-HSL rapidly decreases viability and induces apoptosis in LS174T goblet cells. In this study, the effects of 100 μM C12-HSL on mitochondrial function and cell proliferation in LS174T cells treated for 4 h were evaluated by real-time PCR, enzyme-linked immunosorbent assay (ELISA) and flow cytometry. The results showed that the activities of mitochondrial respiratory chain complexes IV and V were significantly increased (P < 0.05) in LS174T cells after C12-HSL treatment, with elevated intracellular ATP generation (P < 0.05). Flow cytometry analysis revealed significantly increased intracellular Ca 2+ levels (P < 0.05), as well as disrupted mitochondrial activity and cell cycle arrest upon C12-HSL treatment. Apoptosis and cell proliferation related genes showed markedly altered expression levels (P < 0.05) in LS174T cells after C12-HSL treatment. Moreover, the paraoxonase 2 (PON2) inhibitor TQ416 (1 μM) remarkably reversed the above C12-HSL associated effects in LS174T cells. These findings indicated that C12-HSL alters mitochondrial energy production and function, and inhibits cell proliferation in LS174T cells, with PON2 involvement. Copyright © 2018 Elsevier Inc. All rights reserved.

Phagocytic cell function in active brucellosis.

PubMed Central

Ocon, P; Reguera, J M; Morata, P; Juarez, C; Alonso, A; Colmenero, J D

1994-01-01

In this study, we analyzed phagocytic cell function in 51 patients with active brucellosis and its relationship with different clinical, serological, and evolutionary variables. A control group was made up of 30 blood donors of similar geographic extraction, age, and sex, with no previous history of brucellosis or known exposure ot the infection or specific antibodies. The investigations were carried out at the time of diagnosis, at the conclusion of treatment, and after 6 months of follow-up. Polymorphonuclear leukocyte adherence and nitroblue tetrazolium reduction in response to Brucella antigen were significantly increased in the patients at the time of diagnosis with respect to the control group. In contrast, chemotaxis in response to Brucella antigen and phagocytosis were significantly reduced in the patients with respect to the control group. The alterations in phagocytic cell function were greater in patients with bacteremia, with focal forms of the disease, or with a longer diagnostic delay. Most of these initial alterations tended to normalize with treatment, indicating their transient character. PMID:8112863

B-cell subset alterations and correlated factors in HIV-1 infection.

PubMed

Pensieroso, Simone; Galli, Laura; Nozza, Silvia; Ruffin, Nicolas; Castagna, Antonella; Tambussi, Giuseppe; Hejdeman, Bo; Misciagna, Donatella; Riva, Agostino; Malnati, Mauro; Chiodi, Francesca; Scarlatti, Gabriella

2013-05-15

During HIV-1 infection, the development, phenotype, and functionality of B cells are impaired. Transitional B cells and aberrant B-cell populations arise in blood, whereas a declined percentage of resting memory B cells is detected. Our study aimed at pinpointing the demographic, immunological, and viral factors driving these pathological findings, and the role of antiretroviral therapy in reverting these alterations. B-cell phenotype and correlating factors were evaluated. Variations in B-cell subsets were evaluated by flow cytometry in HIV-1-infected individuals naive to therapy, elite controllers, and patients treated with antiretroviral drugs (virological control or failure). Multivariable analysis was performed to identify variables independently associated with the B-cell alterations. Significant differences were observed among patients' groups in relation to all B-cell subsets. Resting memory B cells were preserved in patients naive to therapy and elite controllers, but reduced in treated patients. Individuals naive to therapy and experiencing multidrug failure, as well as elite controllers, had significantly higher levels of activated memory B cells compared to healthy controls. In the multivariate analysis, plasma viral load and nadir CD4 T cells independently correlated with major B-cell alterations. Coinfection with hepatitis C but not hepatitis B virus also showed an impact on specific B-cell subsets. Successful protracted antiretroviral treatment led to normalization of all B-cell subsets with exception of resting memory B cells. Our results indicate that viremia and nadir CD4 T cells are important prognostic markers of B-cell perturbations and provide evidence that resting memory B-cell depletion during chronic infection is not reverted upon successful antiretroviral therapy.

An imidazole functionalized pentameric thiophene displays different staining patterns in normal and malignant cells

NASA Astrophysics Data System (ADS)

Nilsson, Peter; Magnusson, Karin; Appelqvist, Hanna; Cieslar-Pobuda, Artur; Bäck, Marcus; Kågedal, Bertil; Jonasson, Jon; Los, Marek

2015-10-01

Molecular tools for fluorescent imaging of cells and their components are vital for understanding the function and activity of cells. Here, we report an imidazole functionalized pentameric oligothiophene, p-HTIm, that can be utilized for fluorescent imaging of cells. p-HTIm fluorescence in normal cells appeared in a peripheral punctate pattern partially co-localized with lysosomes, whereas a one-sided perinuclear Golgi associated localization of the dye was observed in malignant cells. The uptake of p-HTIm was temperature dependent and the intracellular target was reached within 1 h after staining. The ability of p-HTIm to stain cells was reduced when the imidazole side chain was chemically altered, verifying that specific imidazole side-chain functionalities are necessary for achieving the observed cellular staining. Our findings confirm that properly functionalized oligothiophenes can be utilized as fluorescent tools for vital staining of cells and that the selectivity towards distinct intracellular targets are highly dependent on the side-chain functionalities along the conjugated thiophene backbone.

Functional defect in regulatory T cells in myasthenia gravis

PubMed Central

Thiruppathi, Muthusamy; Rowin, Julie; Jiang, Qin Li; Sheng, Jian Rong; Prabhakar, Bellur S.; Meriggioli, Matthew N.

2012-01-01

Forkhead box P3 (FOXP3)+ is a transcription factor necessary for the function of regulatory T cells (Treg cells). Treg cells maintain immune homeostasis and self-tolerance, and play an important role in the prevention of autoimmune disease. Here, we discuss the role of Treg cells in the pathogenesis of myasthenia gravis (MG) and review evidence indicating that a significant defect in Treg cell in vitro suppressive function exists in MG patients, without an alteration in circulating frequency. This functional defect is associated with a reduced expression of key functional molecules such as FOXP3 on isolated Treg cells and appears to be more pronounced in immunosuppression-naive MG patients. In vitro administration of granulocyte-macrophage colony-stimulating factor (GM-CSF) enhanced the suppressive function of Treg cells and up-regulated FOXP3 expression. These findings indicate a clinically relevant Treg cell–intrinsic defect in immune regulation in MG that may reveal a novel therapeutic target. PMID:23252899

Platform for combined analysis of functional and biomolecular phenotypes of the same cell

PubMed Central

Kelbauskas, L.; Ashili, S.; Zeng, J.; Rezaie, A.; Lee, K.; Derkach, D.; Ueberroth, B.; Gao, W.; Paulson, T.; Wang, H.; Tian, Y.; Smith, D.; Reid, B.; Meldrum, Deirdre R.

2017-01-01

Functional and molecular cell-to-cell variability is pivotal at the cellular, tissue and whole-organism levels. Yet, the ultimate goal of directly correlating the function of the individual cell with its biomolecular profile remains elusive. We present a platform for integrated analysis of functional and transcriptional phenotypes in the same single cells. We investigated changes in the cellular respiration and gene expression diversity resulting from adaptation to repeated episodes of acute hypoxia in a premalignant progression model. We find differential, progression stage-specific alterations in phenotypic heterogeneity and identify cells with aberrant phenotypes. To our knowledge, this study is the first demonstration of an integrated approach to elucidate how heterogeneity at the transcriptional level manifests in the physiologic profile of individual cells in the context of disease progression. PMID:28300162

Diabetes and Stem Cell Function

PubMed Central

Fujimaki, Shin; Wakabayashi, Tamami; Takemasa, Tohru; Asashima, Makoto; Kuwabara, Tomoko

2015-01-01

Diabetes mellitus is one of the most common serious metabolic diseases that results in hyperglycemia due to defects of insulin secretion or insulin action or both. The present review focuses on the alterations to the diabetic neuronal tissues and skeletal muscle, including stem cells in both tissues, and the preventive effects of physical activity on diabetes. Diabetes is associated with various nervous disorders, such as cognitive deficits, depression, and Alzheimer's disease, and that may be caused by neural stem cell dysfunction. Additionally, diabetes induces skeletal muscle atrophy, the impairment of energy metabolism, and muscle weakness. Similar to neural stem cells, the proliferation and differentiation are attenuated in skeletal muscle stem cells, termed satellite cells. However, physical activity is very useful for preventing the diabetic alteration to the neuronal tissues and skeletal muscle. Physical activity improves neurogenic capacity of neural stem cells and the proliferative and differentiative abilities of satellite cells. The present review proposes physical activity as a useful measure for the patients in diabetes to improve the physiological functions and to maintain their quality of life. It further discusses the use of stem cell-based approaches in the context of diabetes treatment. PMID:26075247

Cross-Species Analysis of Nicotine-Induced Proteomic Alterations in Pancreatic Cells

PubMed Central

Paulo, Joao A.; Urrutia, Raul; Kadiyala, Vivek; Banks, Peter

2014-01-01

Background Toxic compounds in tobacco, such as nicotine, may have adversely affect pancreatic function. We aim to determine nicotine-induced protein alterations in pancreatic cells, which may reveal a link between nicotine exposure and pancreatic disease. Methods We compared the proteomic alterations induced by nicotine treatment in cultured pancreatic cells (mouse, rat and human stellate cells and human duct cells) using mass spectrometry-based techniques, specifically GeLC-MS/MS and spectral counting. Results We identified thousands of proteins in pancreatic cells, hundreds of which were identified exclusively or in higher abundance in either nicotine-treated or untreated cells. Inter-species comparisons of stellate cell proteins revealed several differentially-abundant proteins (in nicotine treated versus untreated cells) common among the 3 species. Proteins appearing in all nicotine-treated stellate cells include amyloid beta (A4), procollagen type VI alpha 1, integral membrane protein 2B,and Toll interacting protein. Conclusions Proteins which were differentially expressed upon nicotine treatment across cell lines, were enriched in certain pathways, including nAChR, cytokine, and integrin signaling. At this analytical depth, we conclude that similar pathways are affected by nicotine, but alterations at the protein level among stellate cells of different species vary. Further interrogation of such pathways will lead to insights into the potential effect of nicotine on pancreatic cells at the biomolecular level and the extension of this concept to the effect of nicotine on pancreatic disease. PMID:23456891

Gestational diabetes induces alterations in the function of neonatal endothelial colony-forming cells.

PubMed

Blue, Emily K; DiGiuseppe, Robert; Derr-Yellin, Ethel; Acosta, Juan Carlos; Pay, S Louise; Hanenberg, Helmut; Schellinger, Megan M; Quinney, Sara K; Mund, Julie A; Case, Jamie; Haneline, Laura S

2014-02-01

Children born to mothers with gestational diabetes mellitus (GDM) experience increased risk of developing hypertension, type 2 diabetes mellitus, and obesity. Disrupted function of endothelial colony-forming cells (ECFCs) may contribute to this enhanced risk. The goal of this study was to determine whether cord blood ECFCs from GDM pregnancies exhibit altered functionality. ECFCs isolated from the cord blood of control and GDM pregnancies were assessed for proliferation, senescence, and Matrigel network formation. The requirement for p38MAPK in hyperglycemia-induced senescence was determined using inhibition and overexpression studies. GDM-exposed ECFCs were more proliferative than control ECFCs. However, GDM-exposed ECFCs exhibited decreased network-forming ability in Matrigel. Aging of ECFCs by serial passaging led to increased senescence and reduced proliferation of GDM-exposed ECFCs. ECFCs from GDM pregnancies were resistant to hyperglycemia-induced senescence compared with those from controls. In response to hyperglycemia, control ECFCs activated p38MAPK, which was required for hyperglycemia-induced senescence. In contrast, GDM-exposed ECFCs showed no change in p38MAPK activation under equivalent conditions. Intrauterine exposure of ECFCs to GDM induces unique phenotypic alterations. The resistance of GDM-exposed ECFCs to hyperglycemia-induced senescence and decreased p38MAPK activation suggest that these progenitor cells have undergone changes that induce tolerance to a hyperglycemic environment.

Gestational diabetes induces alterations in the function of neonatal endothelial colony forming cells

PubMed Central

Blue, Emily K.; DiGiuseppe, Robert; Derr-Yellin, Ethel; Acosta, Juan Carlos; Pay, S. Louise; Hanenberg, Helmut; Schellinger, Megan M.; Quinney, Sara K.; Mund, Julie A.; Case, Jamie; Haneline, Laura S.

2014-01-01

Background Children born to mothers with gestational diabetes mellitus (GDM) experience increased risk of developing hypertension, type 2 diabetes mellitus, and obesity. Disrupted function of endothelial colony forming cells (ECFCs) may contribute to this enhanced risk. The goal of this study was to determine if cord blood ECFCs from GDM pregnancies exhibit altered functionality. Methods ECFCs isolated from the cord blood of control and GDM pregnancies were assessed for proliferation, senescence, and Matrigel network formation. The requirement for p38MAPK in hyperglycemia-induced senescence was determined using inhibitor and overexpression studies. Results GDM ECFCs were more proliferative than control ECFCs. However, GDM ECFCs exhibited decreased network forming ability in Matrigel. Aging of ECFCs by serial passaging led to increased senescence and reduced proliferation of GDM ECFCs. ECFCs from GDM pregnancies were resistant to hyperglycemia-induced senescence compared to controls. In response to hyperglycemia, control ECFCs activated p38MAPK, which was required for hyperglycemia-induced senescence. In contrast, GDM ECFCs had no change in p38MAPK activation under equivalent conditions. Conclusion Intrauterine exposure of ECFCs to GDM induces unique phenotypic alterations. The resistance of GDM ECFCs to hyperglycemia-induced senescence and decreased p38MAPK suggest that these progenitor cells have undergone changes to induce tolerance to a hyperglycemic environment. PMID:24232636

Environmentally Induced Transgenerational Epigenetic Reprogramming of Primordial Germ Cells and the Subsequent Germ Line

PubMed Central

Skinner, Michael K.; Haque, Carlos Guerrero-Bosagna M.; Nilsson, Eric; Bhandari, Ramji; McCarrey, John R.

2013-01-01

A number of environmental factors (e.g. toxicants) have been shown to promote the epigenetic transgenerational inheritance of disease and phenotypic variation. Transgenerational inheritance requires the germline transmission of altered epigenetic information between generations in the absence of direct environmental exposures. The primary periods for epigenetic programming of the germ line are those associated with primordial germ cell development and subsequent fetal germline development. The current study examined the actions of an agricultural fungicide vinclozolin on gestating female (F0 generation) progeny in regards to the primordial germ cell (PGC) epigenetic reprogramming of the F3 generation (i.e. great-grandchildren). The F3 generation germline transcriptome and epigenome (DNA methylation) were altered transgenerationally. Interestingly, disruptions in DNA methylation patterns and altered transcriptomes were distinct between germ cells at the onset of gonadal sex determination at embryonic day 13 (E13) and after cord formation in the testis at embryonic day 16 (E16). A larger number of DNA methylation abnormalities (epimutations) and transcriptional alterations were observed in the E13 germ cells than in the E16 germ cells. These observations indicate that altered transgenerational epigenetic reprogramming and function of the male germline is a component of vinclozolin induced epigenetic transgenerational inheritance of disease. Insights into the molecular control of germline transmitted epigenetic inheritance are provided. PMID:23869203

Altered epidermal growth factor-like sequences provide evidence for a role of Notch as a receptor in cell fate decisions.

PubMed

Heitzler, P; Simpson, P

1993-03-01

In Drosophila each neural precursor is chosen from a group of cells through cell interactions mediated by Notch and Delta which may function as receptor and ligand (signal), respectively, in a lateral signalling pathway. The cells of a group are equipotential and express both Notch and Delta. Hyperactive mutant Notch molecules, (Abruptex), probably have an enhanced affinity for the ligand. When adjacent to wild-type cells, cells bearing the Abruptex proteins are unable to produce the signal. It is suggested that in addition to the binding of Notch molecules on one cell to the Delta molecules of opposing cells, the Notch and Delta proteins on the surface of the same cell may interact. Binding between a cell's own Notch and Delta molecules would alter the availability of these proteins to interact with their counterparts on adjacent cells.

Study of adaptation to altered gravity through systems analysis of motor control.

PubMed

Fox, R A; Daunton, N G; Corcoran, M L

1998-01-01

Maintenance of posture and production of functional, coordinated movement demand integration of sensory feedback with spinal and supra-spinal circuitry to produce adaptive motor control in altered gravity (G). To investigate neuroplastic processes leading to optimal performance in altered G we have studied motor control in adult rats using a battery of motor function tests following chronic exposure to various treatments (hyper-G, hindlimb suspension, chemical distruction of hair cells, space flight). These treatments differentially affect muscle fibers, vestibular receptors, and behavioral compensations and, in consequence, differentially disrupt air righting, swimming, posture and gait. The time-course of recovery from these disruptions varies depending on the function tested and the duration and type of treatment. These studies, with others (e.g., D'Amelio et al. in this volume), indicate that adaptation to altered gravity involves alterations in multiple sensory-motor systems that change at different rates. We propose that the use of parallel studies under different altered G conditions will most efficiently lead to an understanding of the modifications in central (neural) and peripheral (sensory and neuromuscular) systems that underlie sensory-motor adaptation in active, intact individuals.

Study of adaptation to altered gravity through systems analysis of motor control

NASA Astrophysics Data System (ADS)

Fox, R. A.; Daunton, N. G.; Corcoran, M. L.

Maintenance of posture and production of functional, coordinated movement demand integration of sensory feedback with spinal and supra-spinal circuitry to produce adaptive motor control in altered gravity (G). To investigate neuroplastic processes leading to optimal performance in altered G we have studied motor control in adult rats using a battery of motor function tests following chronic exposure to various treatments (hyper-G, hindlimb suspension, chemical distruction of hair cells, space flight). These treatments differentially affect muscle fibers, vestibular receptors, and behavioral compensations and, in consequence, differentially disrupt air righting, swimming, posture and gait. The time-course of recovery from these disruptions varies depending on the function tested and the duration and type of treatment. These studies, with others (e.g., D'Amelio et al. in this volume), indicate that adaptation to altered gravity involves alterations in multiple sensory-motor systems that change at different rates. We propose that the use of parallel studies under different altered G conditions will most efficiently lead to an understanding of the modifications in central (neural) and peripheral (sensory and neuromuscular) systems that underlie sensory-motor adaptation in active, intact individuals.

Activin Modulates the Transcriptional Response of LβT2 Cells to Gonadotropin-Releasing Hormone and Alters Cellular Proliferation

PubMed Central

Zhang, Hao; Bailey, Janice S.; Coss, Djurdjica; Lin, Bo; Tsutsumi, Rie; Lawson, Mark A.; Mellon, Pamela L.; Webster, Nicholas J. G.

2009-01-01

Both GnRH and activin are crucial for the correct function of pituitary gonadotrope cells. GnRH regulates LH and FSH synthesis and secretion and gonadotrope proliferation, whereas activin is essential for expression of FSH. Little is known, however, about the interplay of signaling downstream of these two hormones. In this study, we undertook expression profiling to determine how activin pre-treatment alters the transcriptional response of LβT2 gonadotrope cells to GnRH stimulation. Activin treatment alone altered the transcriptional profile of 303 genes including inducing that of the 17β-hydroxysteroid dehydrogenase B1 gene that converts estrone to 17β-estradiol, altering the sensitivity of the cells to estrone. Furthermore, activin had a dramatic effect on the response of LβT2 cells to GnRH. Hierarchical clustering of 2453 GnRH-responsive genes identified groups of genes the response of which to GnRH was either enhanced or blunted after activin treatment. Mapping of these genes to gene ontology classifications or signaling pathways highlighted significant differences in the classes of altered genes. In the presence of activin, GnRH regulates genes in pathways controlling cell energetics, cytoskeletal rearrangements, organelle organization, and mitosis in the absence of activin, but genes controlling protein processing, cell differentiation, and secretion. Therefore, we demonstrated that activin enhanced GnRH induction of p38MAPK activity, caused GnRH-dependent phosphorylation of p53, and reduced the ability of GnRH to cause G1 arrest. Thus, although activin alone changes a modest number of transcripts, activin pretreatment dramatically alters the response to GnRH from an antiproliferative response to a more differentiated, synthetic response appropriate for a secretory cell. PMID:16772531

Altered decorin leads to disrupted endothelial cell function: a possible mechanism in the pathogenesis of fetal growth restriction?

PubMed

Chui, A; Murthi, P; Gunatillake, T; Brennecke, S P; Ignjatovic, V; Monagle, P T; Whitelock, J M; Said, J M

2014-08-01

Fetal growth restriction (FGR) is a key cause of adverse pregnancy outcome where maternal and fetal factors are identified as contributing to this condition. Idiopathic FGR is associated with altered vascular endothelial cell functions. Decorin (DCN) has important roles in the regulation of endothelial cell functions in vascular environments. DCN expression is reduced in FGR. The objectives were to determine the functional consequences of reduced DCN in a human microvascular endothelial cell line model (HMVEC), and to determine downstream targets of DCN and their expression in primary placental microvascular endothelial cells (PLECs) from control and FGR-affected placentae. Short-interference RNA was used to reduce DCN expression in HMVECs and the effect on proliferation, angiogenesis and thrombin generation was determined. A Growth Factor PCR Array was used to identify downstream targets of DCN. The expression of target genes in control and FGR PLECs was performed. DCN reduction decreased proliferation and angiogenesis but increased thrombin generation with no effect on apoptosis. The array identified three targets of DCN: FGF17, IL18 and MSTN. Validation of target genes confirmed decreased expression of VEGFA, MMP9, EGFR1, IGFR1 and PLGF in HMVECs and PLECs from control and FGR pregnancies. Reduction of DCN in vascular endothelial cells leads to disrupted cell functions. The targets of DCN include genes that play important roles in angiogenesis and cellular growth. Therefore, differential expression of these may contribute to the pathogenesis of FGR and disease states in other microvascular circulations. Copyright © 2014 Elsevier Ltd. All rights reserved.

The immune system which adversely alter thyroid functions: a review on the concept of autoimmunity.

PubMed

Mansourian, Azad Reza

2010-08-15

The immune system protect individual from many pathogens exists within our environment and in human body, by destroying them through molecular and cellular mechanism of B and T cells of immune system. Autoimmunity is an adverse relation of immune system against non- foreign substances leaving behind either alters the normal function or destroying the tissue involved. Autoimmunity occur in genetically predispose persons with familial connections. The autoimmunity to the thyroid gland mainly consists of Hashimato thyroiditis and Grave's disease, the two end of spectrum in thyroid function of hypo and hyperactivity, respectively. The thyroid stimulating hormone receptor, thyroglobuline, enzymes of thyroid hormones synthesis are targeted by autoantibodies and cell- mediated reactions. The aim of this review is to explore the studies reported on the autoimmunity to the thyroid gland.

The effects of chemotherapeutics on cellular metabolism and consequent immune recognition.

PubMed

Newell, M Karen; Melamede, Robert; Villalobos-Menuey, Elizabeth; Swartzendruber, Douglas; Trauger, Richard; Camley, Robert E; Crisp, William

2004-02-02

Awidely held view is that oncolytic agents induce death of tumor cells directly. In this report we review and discuss the apoptosis-inducing effects of chemotherapeutics, the effects of chemotherapeutics on metabolic function, and the consequent effects of metabolic function on immune recognition. Finally, we propose that effective chemotherapeutic and/or apoptosis-inducing agents, at concentrations that can be achieved physiologically, do not kill tumor cells directly. Rather, we suggest that effective oncolytic agents sensitize immunologically altered tumor cells to immune recognition and immune-directed cell death.

The effects of chemotherapeutics on cellular metabolism and consequent immune recognition

PubMed Central

Newell, M Karen; Melamede, Robert; Villalobos-Menuey, Elizabeth; Swartzendruber, Douglas; Trauger, Richard; Camley, Robert E; Crisp, William

2004-01-01

A widely held view is that oncolytic agents induce death of tumor cells directly. In this report we review and discuss the apoptosis-inducing effects of chemotherapeutics, the effects of chemotherapeutics on metabolic function, and the consequent effects of metabolic function on immune recognition. Finally, we propose that effective chemotherapeutic and/or apoptosis-inducing agents, at concentrations that can be achieved physiologically, do not kill tumor cells directly. Rather, we suggest that effective oncolytic agents sensitize immunologically altered tumor cells to immune recognition and immune-directed cell death. PMID:14756899

Phytochemicals perturb membranes and promiscuously alter protein function.

PubMed

Ingólfsson, Helgi I; Thakur, Pratima; Herold, Karl F; Hobart, E Ashley; Ramsey, Nicole B; Periole, Xavier; de Jong, Djurre H; Zwama, Martijn; Yilmaz, Duygu; Hall, Katherine; Maretzky, Thorsten; Hemmings, Hugh C; Blobel, Carl; Marrink, Siewert J; Koçer, Armağan; Sack, Jon T; Andersen, Olaf S

2014-08-15

A wide variety of phytochemicals are consumed for their perceived health benefits. Many of these phytochemicals have been found to alter numerous cell functions, but the mechanisms underlying their biological activity tend to be poorly understood. Phenolic phytochemicals are particularly promiscuous modifiers of membrane protein function, suggesting that some of their actions may be due to a common, membrane bilayer-mediated mechanism. To test whether bilayer perturbation may underlie this diversity of actions, we examined five bioactive phenols reported to have medicinal value: capsaicin from chili peppers, curcumin from turmeric, EGCG from green tea, genistein from soybeans, and resveratrol from grapes. We find that each of these widely consumed phytochemicals alters lipid bilayer properties and the function of diverse membrane proteins. Molecular dynamics simulations show that these phytochemicals modify bilayer properties by localizing to the bilayer/solution interface. Bilayer-modifying propensity was verified using a gramicidin-based assay, and indiscriminate modulation of membrane protein function was demonstrated using four proteins: membrane-anchored metalloproteases, mechanosensitive ion channels, and voltage-dependent potassium and sodium channels. Each protein exhibited similar responses to multiple phytochemicals, consistent with a common, bilayer-mediated mechanism. Our results suggest that many effects of amphiphilic phytochemicals are due to cell membrane perturbations, rather than specific protein binding.

Phytochemicals Perturb Membranes and Promiscuously Alter Protein Function

PubMed Central

2015-01-01

A wide variety of phytochemicals are consumed for their perceived health benefits. Many of these phytochemicals have been found to alter numerous cell functions, but the mechanisms underlying their biological activity tend to be poorly understood. Phenolic phytochemicals are particularly promiscuous modifiers of membrane protein function, suggesting that some of their actions may be due to a common, membrane bilayer-mediated mechanism. To test whether bilayer perturbation may underlie this diversity of actions, we examined five bioactive phenols reported to have medicinal value: capsaicin from chili peppers, curcumin from turmeric, EGCG from green tea, genistein from soybeans, and resveratrol from grapes. We find that each of these widely consumed phytochemicals alters lipid bilayer properties and the function of diverse membrane proteins. Molecular dynamics simulations show that these phytochemicals modify bilayer properties by localizing to the bilayer/solution interface. Bilayer-modifying propensity was verified using a gramicidin-based assay, and indiscriminate modulation of membrane protein function was demonstrated using four proteins: membrane-anchored metalloproteases, mechanosensitive ion channels, and voltage-dependent potassium and sodium channels. Each protein exhibited similar responses to multiple phytochemicals, consistent with a common, bilayer-mediated mechanism. Our results suggest that many effects of amphiphilic phytochemicals are due to cell membrane perturbations, rather than specific protein binding. PMID:24901212

Physical confinement alters tumor cell adhesion and migration phenotypes

PubMed Central

Balzer, Eric M.; Tong, Ziqiu; Paul, Colin D.; Hung, Wei-Chien; Stroka, Kimberly M.; Boggs, Amanda E.; Martin, Stuart S.; Konstantopoulos, Konstantinos

2012-01-01

Cell migration on planar surfaces is driven by cycles of actin protrusion, integrin-mediated adhesion, and myosin-mediated contraction; however, this mechanism may not accurately describe movement in 3-dimensional (3D) space. By subjecting cells to restrictive 3D environments, we demonstrate that physical confinement constitutes a biophysical stimulus that alters cell morphology and suppresses mesenchymal motility in human breast carcinoma (MDA-MB-231). Dorsoventral polarity, stress fibers, and focal adhesions are markedly attenuated by confinement. Inhibitors of myosin, Rho/ROCK, or β1-integrins do not impair migration through 3-μm-wide channels (confinement), even though these treatments repress motility in 50-μm-wide channels (unconfined migration) by ≥50%. Strikingly, confined migration persists even when F-actin is disrupted, but depends largely on microtubule (MT) dynamics. Interfering with MT polymerization/depolymerization causes confined cells to undergo frequent directional changes, thereby reducing the average net displacement by ≥80% relative to vehicle controls. Live-cell EB1-GFP imaging reveals that confinement redirects MT polymerization toward the leading edge, where MTs continuously impact during advancement of the cell front. These results demonstrate that physical confinement can induce cytoskeletal alterations that reduce the dependence of migrating cells on adhesion-contraction force coupling. This mechanism may explain why integrins can exhibit reduced or altered function during migration in 3D environments.—Balzer, E. M., Tong, Z., Paul, C. D., Hung, W.-C., Stroka, K. M., Boggs, A. E., Martin, S. S., Konstantopoulos, K. Physical confinement alters tumor cell adhesion and migration phenotypes. PMID:22707566

Elevated GRIA1 mRNA expression in Layer II/III and V pyramidal cells of the DLPFC in schizophrenia

PubMed Central

O’Connor, J.A.; Hemby, S.E.

2012-01-01

The functional integrity of the dorsolateral prefrontal cortex (DLPFC) is altered in schizophrenia leading to profound deficits in working memory and cognition. Growing evidence indicates that dysregulation of glutamate signaling may be a significant contributor to the pathophysiology mediating these effects; however, the contribution of NMDA and AMPA receptors in the mediation of this deficit remains unclear. The equivocality of data regarding ionotropic glutamate receptor alterations of subunit expression in the DLPFC of schizophrenics is likely reflective of subtle alterations in the cellular and molecular composition of specific neuronal populations within the region. Given previous evidence of Layer II/III and V pyramidal cell alterations in schizophrenia and the significant influence of subunit composition on NMDA and AMPA receptor function, laser capture microdissection combined with quantitative PCR was used to examine the expression of AMPA (GRIA1-4) and NMDA (GRIN1, 2A and 2B) subunit mRNA levels in Layer II/III and Layer V pyramidal cells in the DLPFC. Comparisons were made between individuals diagnosed with schizophrenia, bipolar disorder, major depressive disorder and controls (n=15/group). All subunits were expressed at detectable levels in both cell populations for all diseases as well as for the control group. Interestingly, GRIA1 mRNA was significantly increased in both cell types in the schizophrenia group compare to controls, while similar trends were observed in major depressive disorder (Layers II/III and V) and bipolar disorder (Layer V). These data suggest that increased GRIA1 subunit expression may contribute to schizophrenia pathology. PMID:17942280

Effects of butyltin exposures on MAP kinase dependent transcription regulators in human natural killer cells

PubMed Central

Person, Rachel J.; Whalen, Margaret M.

2010-01-01

Natural Killer (NK) cells are a major immune defense mechanism against cancer development and viral infection. The butyltins (BTs), tributyltin (TBT) and dibutyltin (DBT) have been widely used in industrial and other applications and significantly contaminate the environment. Both TBT and DBT have been detected in human blood. These compounds inhibit the lytic and binding function of human NK cells and thus could increase the incidence of cancer and viral infections. Butyltin (BT)-induced loss of NK function is accompanied by activation of mitogen activated protein kinases (MAPKs) and decreases in expression of cell-surface and cytolytic proteins. MAPKs activate components of the transcription regulator AP-1 and activate the transcription regulator Elk-1. Based on the fact that BTs activate MAPKs and alter protein expression, the current study examined the effect of BT exposures on the levels and phosphorylation states of the components of AP-1 and the phosphorylation state of Elk-1. Exposure to 300 nM TBT for 10 min increased the phosphorylation of c-Jun in NK cells. 1 h exposures to 300 nM and 200 nM TBT increased the phosphorylation and overall level of c-Jun. During a 300 nM treatment with TBT for 1 h the binding activity of AP-1 was significantly decreased. There were no significant alterations of AP-1 components or of Elk-1 with DBT exposures. Thus, it appears that TBT-induced alterations on phosphorylation, total levels and binding activity of c-Jun might contribute to, but are not fully responsible for, TBT-induced alterations of NK protein expression. PMID:20370538

Effects of butyltin exposures on MAP kinase-dependent transcription regulators in human natural killer cells.

PubMed

Person, Rachel J; Whalen, Margaret M

2010-06-01

Natural killer (NK) cells are a major immune defense mechanism against cancer development and viral infection. The butyltins (BTs), tributyltin (TBT) and dibutyltin (DBT), have been widely used in industrial and other applications and significantly contaminate the environment. Both TBT and DBT have been detected in human blood. These compounds inhibit the lytic and binding function of human NK cells and thus could increase the incidence of cancer and viral infections. Butyltin (BT)-induced loss of NK function is accompanied by activation of mitogen activated protein kinases (MAPKs) and decreases in expression of cell-surface and cytolytic proteins. MAPKs activate components of the transcription regulator AP-1 and activate the transcription regulator Elk-1. Based on the fact that BTs activate MAPKs and alter protein expression, the current study examined the effect of BT exposures on the levels and phosphorylation states of the components of AP-1 and the phosphorylation state of Elk-1. Exposure to 300 nM TBT for 10 min increased the phosphorylation of c-Jun in NK cells. One hour exposures to 300 nM and 200 nM TBT increased the phosphorylation and overall level of c-Jun. During a 300 nM treatment with TBT for 1 h the binding activity of AP-1 was significantly decreased. There were no significant alterations of AP-1 components or of Elk-1 with DBT exposures. Thus, it appears that TBT-induced alterations on phosphorylation, total levels, and binding activity of c-Jun might contribute to, but are not fully responsible for, TBT-induced alterations of NK protein expression.

Obesity Determines the Immunophenotypic Profile and Functional Characteristics of Human Mesenchymal Stem Cells From Adipose Tissue

PubMed Central

Pachón-Peña, Gisela; Serena, Carolina; Ejarque, Miriam; Petriz, Jordi; Duran, Xevi; Oliva-Olivera, W.; Simó, Rafael; Tinahones, Francisco J.

2016-01-01

Adipose tissue is a major source of mesenchymal stem cells (MSCs), which possess a variety of properties that make them ideal candidates for regenerative and immunomodulatory therapies. Here, we compared the immunophenotypic profile of human adipose-derived stem cells (hASCs) from lean and obese individuals, and explored its relationship with the apparent altered plasticity of hASCs. We also hypothesized that persistent hypoxia treatment of cultured hASCs may be necessary but not sufficient to drive significant changes in mature adipocytes. hASCs were obtained from subcutaneous adipose tissue of healthy, adult, female donors undergoing abdominal plastic surgery: lean (n = 8; body mass index [BMI]: 23 ± 1 kg/m2) and obese (n = 8; BMI: 35 ± 5 kg/m2). Cell surface marker expression, proliferation and migration capacity, and adipogenic differentiation potential of cultured hASCs at two different oxygen conditions were studied. Compared with lean-derived hASCs, obese-derived hASCs demonstrated increased proliferation and migration capacity but decreased lipid droplet accumulation, correlating with a higher expression of human leukocyte antigen (HLA)-II and cluster of differentiation (CD) 106 and lower expression of CD29. Of interest, adipogenic differentiation modified CD106, CD49b, HLA-ABC surface protein expression, which was dependent on the donor’s BMI. Additionally, low oxygen tension increased proliferation and migration of lean but not obese hASCs, which correlated with an altered CD36 and CD49b immunophenotypic profile. In summary, the differences observed in proliferation, migration, and differentiation capacity in obese hASCs occurred in parallel with changes in cell surface markers, both under basal conditions and during differentiation. Therefore, obesity is an important determinant of stem cell function independent of oxygen tension. Significance The obesity-related hypoxic environment may have latent effects on human adipose tissue-derived mesenchymal stem cells (hASCs) with potential consequences in mature cells. This study explores the immunophenotypic profile of hASCs obtained from lean and obese individuals and its potential relationship with the altered plasticity of hASCs observed in obesity. In this context, an altered pattern of cell surface marker expression in obese-derived hASCs in both undifferentiated and differentiated stages is demonstrated. Differences in proliferation, migration, and differentiation capacity of hASCs from obese adipose tissue correlated with alterations in cell surface expression. Remarkably, altered plasticity observed in obese-derived hASCs was maintained in the absence of hypoxia, suggesting that these cells might be obesity conditioned. PMID:26956208

GBM heterogeneity as a function of variable epidermal growth factor receptor variant III activity.

PubMed

Lindberg, Olle R; McKinney, Andrew; Engler, Jane R; Koshkakaryan, Gayane; Gong, Henry; Robinson, Aaron E; Ewald, Andrew J; Huillard, Emmanuelle; David James, C; Molinaro, Annette M; Shieh, Joseph T; Phillips, Joanna J

2016-11-29

Abnormal activation of the epidermal growth factor receptor (EGFR) due to a deletion of exons 2-7 of EGFR (EGFRvIII) is a common alteration in glioblastoma (GBM). While this alteration can drive gliomagenesis, tumors harboring EGFRvIII are heterogeneous. To investigate the role for EGFRvIII activation in tumor phenotype we used a neural progenitor cell-based murine model of GBM driven by EGFR signaling and generated tumor progenitor cells with high and low EGFRvIII activation, pEGFRHi and pEGFRLo. In vivo, ex vivo, and in vitro studies suggested a direct association between EGFRvIII activity and increased tumor cell proliferation, decreased tumor cell adhesion to the extracellular matrix, and altered progenitor cell phenotype. Time-lapse confocal imaging of tumor cells in brain slice cultures demonstrated blood vessel co-option by tumor cells and highlighted differences in invasive pattern. Inhibition of EGFR signaling in pEGFRHi promoted cell differentiation and increased cell-matrix adhesion. Conversely, increased EGFRvIII activation in pEGFRLo reduced cell-matrix adhesion. Our study using a murine model for GBM driven by a single genetic driver, suggests differences in EGFR activation contribute to tumor heterogeneity and aggressiveness.

EVI2B is a C/EBPα target gene required for granulocytic differentiation and functionality of hematopoietic progenitors.

PubMed

Zjablovskaja, Polina; Kardosova, Miroslava; Danek, Petr; Angelisova, Pavla; Benoukraf, Touati; Wurm, Alexander A; Kalina, Tomas; Sian, Stephanie; Balastik, Martin; Delwel, Ruud; Brdicka, Tomas; Tenen, Daniel G; Behre, Gerhard; Fiore, Fréderic; Malissen, Bernard; Horejsi, Vaclav; Alberich-Jorda, Meritxell

2017-04-01

Development of hematopoietic populations through the process of differentiation is critical for proper hematopoiesis. The transcription factor CCAAT/enhancer binding protein alpha (C/EBPα) is a master regulator of myeloid differentiation, and the identification of C/EBPα target genes is key to understand this process. Here we identified the Ecotropic Viral Integration Site 2B (EVI2B) gene as a direct target of C/EBPα. We showed that the product of the gene, the transmembrane glycoprotein EVI2B (CD361), is abundantly expressed on the surface of primary hematopoietic cells, the highest levels of expression being reached in mature granulocytes. Using shRNA-mediated downregulation of EVI2B in human and murine cell lines and in primary hematopoietic stem and progenitor cells, we demonstrated impaired myeloid lineage development and altered progenitor functions in EVI2B-silenced cells. We showed that the compromised progenitor functionality in Evi2b-depleted cells can be in part explained by deregulation of cell proliferation and apoptosis. In addition, we generated an Evi2b knockout murine model and demonstrated altered properties of hematopoietic progenitors, as well as impaired G-CSF dependent myeloid colony formation in the knockout cells. Remarkably, we found that EVI2B is significantly downregulated in human acute myeloid leukemia samples characterized by defects in CEBPA. Altogether, our data demonstrate that EVI2B is a downstream target of C/EBPα, which regulates myeloid differentiation and functionality of hematopoietic progenitors.

Wiskott-Aldrich syndrome protein deficiency in B cells results in impaired peripheral homeostasis

PubMed Central

Meyer-Bahlburg, Almut; Becker-Herman, Shirly; Humblet-Baron, Stephanie; Khim, Socheath; Weber, Michele; Bouma, Gerben; Thrasher, Adrian J.; Batista, Facundo D.

2008-01-01

To more precisely identify the B-cell phenotype in Wiskott-Aldrich syndrome (WAS), we used 3 distinct murine in vivo models to define the cell intrinsic requirements for WAS protein (WASp) in central versus peripheral B-cell development. Whereas WASp is dispensable for early bone marrow B-cell development, WASp deficiency results in a marked reduction in each of the major mature peripheral B-cell subsets, exerting the greatest impact on marginal zone and B1a B cells. Using in vivo bromodeoxyuridine labeling and in vitro functional assays, we show that these deficits reflect altered peripheral homeostasis, partially resulting from an impairment in integrin function, rather than a developmental defect. Consistent with these observations, we also show that: (1) WASp expression levels increase with cell maturity, peaking in those subsets exhibiting the greatest sensitivity to WASp deficiency; (2) WASp+ murine B cells exhibit a marked selective advantage beginning at the late transitional B-cell stage; and (3) a similar in vivo selective advantage is manifest by mature WASp+ human B cells. Together, our data provide a better understanding of the clinical phenotype of WAS and suggest that gene therapy might be a useful approach to rescue altered B-cell homeostasis in this disease. PMID:18687984

Changes in Expression of Signal Transduction Proteins in T Lymphocytes of Patients with Leprosy

PubMed Central

Zea, Arnold H.; Ochoa, Maria T.; Ghosh, Paritosh; Longo, Dan L.; Alvord, W. Gregory; Valderrama, Liliana; Falabella, Rafael; Harvey, Linda K.; Saravia, Nancy; Moreno, Luis H.; Ochoa, Augusto C.

1998-01-01

Advanced stages of mycobacterial diseases such as leprosy and tuberculosis are characterized by a loss of T-cell function. The basis of this T-cell dysfunction is not well understood. The present report demonstrates major alterations in the expression of signal transduction molecules in T cells of leprosy patients. These alterations were most frequently observed in lepromatous leprosy (LL) patients. Of 29 LL patients, 69% had decreased T-cell receptor ζ-chain expression, 48% had decreased p56lck tyrosine kinase, and 63% had a loss of nuclear transcription factor NF-κB p65. An electrophoretic mobility shift assay with the gamma interferon core promoter region revealed a loss of the Th1 DNA-binding pattern in LL patients. In contrast, tuberculoid leprosy patients had only minor signal transduction alterations. These novel findings might improve our understanding of the T-cell dysfunction observed in leprosy and other infectious diseases and consequently might lead to better immunologic evaluation of patients. PMID:9453602

Tissue Architecture and Microenvironment Sustain Hormone Signaling | Center for Cancer Research

Cancer.gov

Cells interact with their environments in part through protein receptors embedded in the cell membrane. Activation of a receptor by external signaling molecules sets off a complex chain of events within the cell that can result in alterations in protein structure and function and/or changes in gene expression. Proper integration of these signals is crucial for normal cell

Endocrine Disruptors (Chapter 14) in Mammalian Toxicology Book

EPA Science Inventory

Endocrine disrupting chemicals (EDCs) are exogenous substances that alter endocrine system function(s) and consequently cause adverse health effects in intact organisms or its progeny. The endocrine system is important for a wide range of biological processes, from normal cell si...

Wnt-beta-catenin pathway signals metastasis-associated tumor cell phenotypes in triple negative breast cancers.

PubMed

De, Pradip; Carlson, Jennifer H; Wu, Hui; Marcus, Adam; Leyland-Jones, Brian; Dey, Nandini

2016-07-12

Tumor cells acquire metastasis-associated (MA) phenotypes following genetic alterations in them which cause deregulation of different signaling pathways. Earlier, we reported that an upregulation of the Wnt-beta-catenin pathway (WP) is one of the genetic salient features of triple-negative breast cancer (TNBC), and WP signaling is associated with metastasis in TNBC. Using cBioPortal, here we found that collective % of alteration(s) in WP genes, CTNNB1, APC and DVL1 among breast-invasive-carcinomas was 21% as compared to 56% in PAM50 Basal. To understand the functional relevance of WP in the biology of heterogeneous/metastasizing TNBC cells, we undertook this comprehensive study using 15 cell lines in which we examined the role of WP in the context of integrin-dependent MA-phenotypes. Directional movement of tumor cells was observed by confocal immunofluorescence microscopy and quantitative confocal-video-microscopy while matrigel-invasion was studied by MMP7-specific casein-zymography. WntC59, XAV939, sulindac sulfide and beta-catenin siRNA (1) inhibited fibronectin-directed migration, (2) decreased podia-parameters and motility-descriptors, (3) altered filamentous-actin, (4) decreased matrigel-invasion and (5) inhibited cell proliferation as well as 3D clonogenic growth. Sulindac sulfide and beta-catenin siRNA decreased beta-catenin/active-beta-catenin and MMP7. LWnt3ACM-stimulated proliferation, clonogenicity, fibronectin-directed migration and matrigel-invasion were perturbed by WP-modulators, sulindac sulfide and GDC-0941. We studied a direct involvement of WP in metastasis by stimulating brain-metastasis-specific MDA-MB231BR cells to demonstrate that LWnt3ACM-stimulated proliferation, clonogenicity and migration were blocked following sulindac sulfide, GDC-0941 and beta-catenin knockdown. We present the first evidence showing a direct functional relationship between WP activation and integrin-dependent MA-phenotypes. By proving the functional relationship between WP activation and MA-phenotypes, our data mechanistically explains (1) why different components of WP are upregulated in TNBC, (2) how WP activation is associated with metastasis and (3) how integrin-dependent MA-phenotypes can be regulated by mitigating the WP.

Wnt-beta-catenin pathway signals metastasis-associated tumor cell phenotypes in triple negative breast cancers

PubMed Central

De, Pradip; Carlson, Jennifer H.; Wu, Hui; Marcus, Adam; Leyland-Jones, Brian; Dey, Nandini

2016-01-01

Tumor cells acquire metastasis-associated (MA) phenotypes following genetic alterations in them which cause deregulation of different signaling pathways. Earlier, we reported that an upregulation of the Wnt-beta-catenin pathway (WP) is one of the genetic salient features of triple-negative breast cancer (TNBC), and WP signaling is associated with metastasis in TNBC. Using cBioPortal, here we found that collective % of alteration(s) in WP genes, CTNNB1, APC and DVL1 among breast-invasive-carcinomas was 21% as compared to 56% in PAM50 Basal. To understand the functional relevance of WP in the biology of heterogeneous/metastasizing TNBC cells, we undertook this comprehensive study using 15 cell lines in which we examined the role of WP in the context of integrin-dependent MA-phenotypes. Directional movement of tumor cells was observed by confocal immunofluorescence microscopy and quantitative confocal-video-microscopy while matrigel-invasion was studied by MMP7-specific casein-zymography. WntC59, XAV939, sulindac sulfide and beta-catenin siRNA (1) inhibited fibronectin-directed migration, (2) decreased podia-parameters and motility-descriptors, (3) altered filamentous-actin, (4) decreased matrigel-invasion and (5) inhibited cell proliferation as well as 3D clonogenic growth. Sulindac sulfide and beta-catenin siRNA decreased beta-catenin/active-beta-catenin and MMP7. LWnt3ACM-stimulated proliferation, clonogenicity, fibronection-directed migration and matrigel-invasion were perturbed by WP-modulators, sulindac sulfide and GDC-0941. We studied a direct involvement of WP in metastasis by stimulating brain-metastasis-specific MDA-MB231BR cells to demonstrate that LWnt3ACM-stimulated proliferation, clonogenicity and migration were blocked following sulindac sulfide, GDC-0941 and beta-catenin knockdown. We present the first evidence showing a direct functional relationship between WP activation and integrin-dependent MA-phenotypes. By proving the functional relationship between WP activation and MA-phenotypes, our data mechanistically explains (1) why different components of WP are upregulated in TNBC, (2) how WP activation is associated with metastasis and (3) how integrin-dependent MA-phenotypes can be regulated by mitigating the WP. PMID:27281609

Alterations in CDH15 and KIRREL3 in Patients with Mild to Severe Intellectual Disability

PubMed Central

Bhalla, Kavita; Luo, Yue; Buchan, Tim; Beachem, Michael A.; Guzauskas, Gregory F.; Ladd, Sydney; Bratcher, Shelly J.; Schroer, Richard J.; Balsamo, Janne; DuPont, Barbara R.; Lilien, Jack; Srivastava, Anand K.

2008-01-01

Cell-adhesion molecules play critical roles in brain development, as well as maintaining synaptic structure, function, and plasticity. Here we have found the disruption of two genes encoding putative cell-adhesion molecules, CDH15 (cadherin superfamily) and KIRREL3 (immunoglobulin superfamily), by a chromosomal translocation t(11;16) in a female patient with intellectual disability (ID). We screened coding regions of these two genes in a cohort of patients with ID and controls and identified four nonsynonymous CDH15 variants and three nonsynonymous KIRREL3 variants that appear rare and unique to ID. These variations altered highly conserved residues and were absent in more than 600 unrelated patients with ID and 800 control individuals. Furthermore, in vivo expression studies showed that three of the CDH15 variations adversely altered its ability to mediate cell-cell adhesion. We also show that in neuronal cells, human KIRREL3 colocalizes and interacts with the synaptic scaffolding protein, CASK, recently implicated in X-linked brain malformation and ID. Taken together, our data suggest that alterations in CDH15 and KIRREL3, either alone or in combination with other factors, could play a role in phenotypic expression of ID in some patients. PMID:19012874

Mic60/Mitofilin Overexpression Alters Mitochondrial Dynamics and Attenuates Vulnerability of Dopaminergic Cells to Dopamine and Rotenone

PubMed Central

Van Laar, Victor S.; Berman, Sarah B.; Hastings, Teresa G.

2017-01-01

Mitochondrial dysfunction has been implicated in Parkinson’s disease (PD) neuropathology. Mic60, also known as mitofilin, is a protein of the inner mitochondrial membrane and a key component of the mitochondrial contact site and cristae junction organizing system (MICOS). Mic60 is critical for maintaining mitochondrial membrane structure and function. We previously demonstrated that mitochondrial Mic60 protein is susceptible to both covalent modification and loss in abundance following exposure to dopamine quinone. In this study, we utilized neuronally-differentiated SH-SY5Y and PC12 dopaminergic cell lines to examine the effects of altered Mic60 levels on mitochondrial function and cellular vulnerability in response to PD-relevant stressors. Short hairpin RNA (shRNA)-mediated knockdown of endogenous Mic60 protein in neuronal SH-SY5Y cells significantly potentiated dopamine-induced cell death, which was rescued by co-expressing shRNA-insensitive Mic60. Conversely, in PC12 and SH-SY5Y cells, Mic60 overexpression significantly attenuated both dopamine- and rotenone-induced cell death as compared to controls. Mic60 overexpression in SH-SY5Y cells was also associated with increased mitochondrial respiration, and, following rotenone exposure, increased spare respiratory capacity. Mic60 knockdown cells exhibited suppressed respiration and, following rotenone treatment, decreased spare respiratory capacity. Mic60 overexpression also affected mitochondrial fission/fusion dynamics. PC12 cells overexpressing Mic60 exhibited increased mitochondrial interconnectivity. Further, both PC12 cells and primary rat cortical neurons overexpressing Mic60 displayed suppressed mitochondrial fission and increased mitochondrial length in neurites. These results suggest that altering levels of Mic60 in dopaminergic neuronal cells significantly affects both mitochondrial homeostasis and cellular vulnerability to the PD-relevant stressors dopamine and rotenone, carrying implications for PD pathogenesis. PMID:27001148

Protective role of klotho protein on epithelial cells upon co-culture with activated or senescent monocytes

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

Mytych, Jennifer, E-mail: jennifermytych@gmail.com; Centre of Applied Biotechnology and Basic Sciences, University of Rzeszow, Werynia 502, 36-100 Kolbuszowa; Wos, Izabela

Monocytes ensure proper functioning and maintenance of epithelial cells, while good condition of monocytes is a key factor of these interactions. Although, it was shown that in some circumstances, a population of altered monocytes may appear, there is no data regarding their effect on epithelial cells. In this study, using direct co-culture model with LPS-activated and Dox-induced senescent THP-1 monocytes, we reported for the first time ROS-induced DNA damage, reduced metabolic activity, proliferation inhibition and cell cycle arrest followed by p16-, p21- and p27-mediated DNA damage response pathways activation, premature senescence and apoptosis induction in HeLa cells. Also, we showmore » that klotho protein possessing anti-aging and anti-inflammatory characteristics reduced cytotoxic and genotoxic events by inhibition of insulin/IGF-IR and downregulation of TRF1 and TRF2 proteins. Therefore, klotho protein could be considered as a protective factor against changes caused by altered monocytes in epithelial cells. - Highlights: • Activated and senescent THP-1 monocytes induced cyto- and genotoxicity in HeLa cells. • Altered monocytes provoked oxidative and nitrosative stress-induced DNA damage. • DNA damage activated DDR pathways and lead to premature senescence and apoptosis. • Klotho reduced ROS/RNS-mediated toxicity through insulin/IGF-IR pathway inhibition. • Klotho protects HeLa cells from cyto- and genotoxicity induced by altered monocytes.« less

Role of the nuclear migration protein Lis1 in cell morphogenesis in Ustilago maydis

PubMed Central

Valinluck, Michael; Ahlgren, Sara; Sawada, Mizuho; Locken, Kristopher; Banuett, Flora

2010-01-01

Ustilago maydis is a basidiomycete fungus that exhibits a yeast-like and a filamentous form. Growth of the fungus in the host leads to additional morphological transitions. The different morphologies are characterized by distinct nuclear movements. Dynein and α-tubulin are required for nuclear movements and for cell morphogenesis of the yeast-like form. Lis1 is a microtubule plus-end tracking protein (+TIPs) conserved in eukaryotes and required for nuclear migration and spindle positioning. Defects in nuclear migration result in altered cell fate and aberrant development in metazoans, slow growth in fungi and disease in humans (e.g. lissencephaly). Here we investigate the role of the human LIS1 homolog in U. maydis and demonstrate that it is essential for cell viability, not previously seen in other fungi. With a conditional null mutation we show that lis1 is necessary for nuclear migration in the yeast-like cell and during the dimorphic transition. Studies of asynchronous exponentially growing cells and time-lapse microscopy uncovered novel functions of lis1: It is necessary for cell morphogenesis, positioning of the septum and cell wall integrity. lis1-depleted cells exhibit altered axes of growth and loss of cell polarity leading to grossly aberrant cells with clusters of nuclei and morphologically altered buds devoid of nuclei. Altered septum positioning and cell wall deposition contribute to the aberrant morphology. lis1-depleted cells lyse, indicative of altered cell wall properties or composition. We also demonstrate, with indirect immunofluorescence to visualize tubulin, that lis1 is necessary for the normal organization of the microtubule cytoskeleton: lis1-depleted cells contain more and longer microtubules that can form coils perpendicular to the long axis of the cell. We propose that lis1 controls microtubule dynamics and thus the regulated delivery of vesicles to growth sites and other cell domains that govern nuclear movements. PMID:20524583

Altered cytokine production by dendritic cells from infants with atopic dermatitis.

PubMed

Yao, Weiguo; Chang, JiHoon; Sehra, Sarita; Travers, Jeffrey B; Chang, Cheong-Hee; Tepper, Robert S; Kaplan, Mark H

2010-12-01

Dendritic cells (DC) are potent initiators of immune responses, compared to other professional antigen-presenting cells, based on their ability to capture antigen, express high amounts of MHC and co-stimulatory molecules, and to secrete immunostimulatory cytokines. Altered functions of DC in atopic individuals have been observed, though it is not clear if this is a cause or a result of the development of allergic disease. In this report we demonstrate altered cytokine production by DC isolated from infants with atopic dermatitis but without a diagnosis of asthma, compared to infants with non-atopic dermatitis. Increased production of IL-6, IL-10 and IFNα from DC isolated from atopic infants is less apparent when DC from infants were examined 1 year later. An increase in the same cytokines was observed in neonatal mice that are genetically predisposed towards allergic inflammation. These results suggest that an atopic environment promotes altered cytokine production by DC from infants. Copyright © 2010 Elsevier Inc. All rights reserved.

CLASP2 interacts with p120-catenin and governs microtubule dynamics at adherens junctions

PubMed Central

Shahbazi, Marta N.; Megias, Diego; Epifano, Carolina; Akhmanova, Anna; Gundersen, Gregg G.; Fuchs, Elaine

2013-01-01

Classical cadherins and their connections with microtubules (MTs) are emerging as important determinants of cell adhesion. However, the functional relevance of such interactions and the molecular players that contribute to tissue architecture are still emerging. In this paper, we report that the MT plus end–binding protein CLASP2 localizes to adherens junctions (AJs) via direct interaction with p120-catenin (p120) in primary basal mouse keratinocytes. Reductions in the levels of p120 or CLASP2 decreased the localization of the other protein to cell–cell contacts and altered AJ dynamics and stability. These features were accompanied by decreased MT density and altered MT dynamics at intercellular junction sites. Interestingly, CLASP2 was enriched at the cortex of basal progenitor keratinocytes, in close localization to p120. Our findings suggest the existence of a new mechanism of MT targeting to AJs with potential functional implications in the maintenance of proper cell–cell adhesion in epidermal stem cells. PMID:24368809

Mycoplasma pulmonis Inhibits Electrogenic Ion Transport across Murine Tracheal Epithelial Cell Monolayers

PubMed Central

Lambert, Linda C.; Trummell, Hoa Q.; Singh, Ashvani; Cassell, Gail H.; Bridges, Robert J.

1998-01-01

Murine chronic respiratory disease is characterized by persistent colonization of tracheal and bronchial epithelial cell surfaces by Mycoplasma pulmonis, submucosal and intraluminal immune and inflammatory cells, and altered airway activity. To determine the direct effect of M. pulmonis upon transepithelial ion transport in the absence of immune and inflammatory cell responses, primary mouse tracheal epithelial cell monolayers (MTEs) were apically infected and assayed in Ussing chambers. M. pulmonis-infected MTEs, but not those infected with a nonmurine mycoplasma, demonstrated reductions in amiloride-sensitive Na+ absorption, cyclic AMP, and cholinergic-stimulated Cl− secretion and transepithelial resistance. These effects were shown to require interaction of viable organisms with the apical surface of the monolayer and to be dependent upon organism number and duration of infection. Altered transport due to M. pulmonis was not merely a result of epithelial cell death as evidenced by the following: (i) active transport of Na+ and Cl−, albeit at reduced rates; (ii) normal cell morphology, including intact tight junctions, as demonstrated by electron microscopy; (iii) maintenance of a mean transepithelial resistance of 440 Ω/cm2; and (iv) lack of leakage of fluid from the basolateral to the apical surface of the monolayer. Alteration in epithelial ion transport in vitro is consistent with impaired pulmonary clearance and altered airway function in M. pulmonis-infected animals. Furthermore, the ability of M. pulmonis to alter transport without killing the host cell may explain its successful parasitism and long-term persistence in the host. Further study of the MTE-M. pulmonis model should elucidate the molecular mechanisms which mediate this reduction in transepithelial ion transport. PMID:9423868

Fiber type conversion alters inactivation of voltage-dependent sodium currents in murine C2C12 skeletal muscle cells.

PubMed

Zebedin, Eva; Sandtner, Walter; Galler, Stefan; Szendroedi, Julia; Just, Herwig; Todt, Hannes; Hilber, Karlheinz

2004-08-01

Each skeletal muscle of the body contains a unique composition of "fast" and "slow" muscle fibers, each of which is specialized for certain challenges. This composition is not static, and the muscle fibers are capable of adapting their molecular composition by altered gene expression (i.e., fiber type conversion). Whereas changes in the expression of contractile proteins and metabolic enzymes in the course of fiber type conversion are well described, little is known about possible adaptations in the electrophysiological properties of skeletal muscle cells. Such adaptations may involve changes in the expression and/or function of ion channels. In this study, we investigated the effects of fast-to-slow fiber type conversion on currents via voltage-gated Na+ channels in the C(2)C(12) murine skeletal muscle cell line. Prolonged treatment of cells with 25 nM of the Ca2+ ionophore A-23187 caused a significant shift in myosin heavy chain isoform expression from the fast toward the slow isoform, indicating fast-to-slow fiber type conversion. Moreover, Na+ current inactivation was significantly altered. Slow inactivation less strongly inhibited the Na+ currents of fast-to-slow fiber type-converted cells. Compared with control cells, the Na+ currents of converted cells were more resistant to block by tetrodotoxin, suggesting enhanced relative expression of the cardiac Na+ channel isoform Na(v)1.5 compared with the skeletal muscle isoform Na(v)1.4. These results imply that fast-to-slow fiber type conversion of skeletal muscle cells involves functional adaptation of their electrophysiological properties.

Arenaviruses. Genes, proteins, and expression

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

Oldstone, M.B.A.

1987-01-01

This book provides a discussion of current knowledge on Arenaviruses. These viruses are the cause of major health problems, such as Lassa fever and Junin virus disease, and have been the Rosetta stone on which many of the major concepts in viral pathogenesis and immunobiology have been built. For example, study of lymphocytic choriomeningitis naturally and experimentally induced infection in the normal mouse host presented the scientific community with the first and definitive work on the following topics: virus induced immune response disease, immunologic tolerance, virus induced immune complex disease, presence and generation of cytotoxic T cells in vitro andmore » in vivo, H-2 restriction and dual recognition phenomena, and viral disease induced by altering physiologic or differential functions of a cell without causing alterations of house keeping or vital functions, i.e. pathology in the absence of cell or tissue lysis.« less

Alterations in Ca2+ Signalling via ER-Mitochondria Contact Site Remodelling in Cancer.

PubMed

Kerkhofs, Martijn; Giorgi, Carlotta; Marchi, Saverio; Seitaj, Bruno; Parys, Jan B; Pinton, Paolo; Bultynck, Geert; Bittremieux, Mart

2017-01-01

Inter-organellar contact sites establish microdomains for localised Ca 2+ -signalling events. One of these microdomains is established between the ER and the mitochondria. Importantly, the so-called mitochondria-associated ER membranes (MAMs) contain, besides structural proteins and proteins involved in lipid exchange, several Ca 2+ -transport systems, mediating efficient Ca 2+ transfer from the ER to the mitochondria. These Ca 2+ signals critically control several mitochondrial functions, thereby impacting cell metabolism, cell death and survival, proliferation and migration. Hence, the MAMs have emerged as critical signalling hubs in physiology, while their dysregulation is an important factor that drives or at least contributes to oncogenesis and tumour progression. In this book chapter, we will provide an overview of the role of the MAMs in cell function and how alterations in the MAM composition contribute to oncogenic features and behaviours.

Phenotypic and Functional Alterations in Circulating Memory CD8 T Cells with Time after Primary Infection.

PubMed

Martin, Matthew D; Kim, Marie T; Shan, Qiang; Sompallae, Ramakrishna; Xue, Hai-Hui; Harty, John T; Badovinac, Vladimir P

2015-10-01

Memory CD8 T cells confer increased protection to immune hosts upon secondary viral, bacterial, and parasitic infections. The level of protection provided depends on the numbers, quality (functional ability), and location of memory CD8 T cells present at the time of infection. While primary memory CD8 T cells can be maintained for the life of the host, the full extent of phenotypic and functional changes that occur over time after initial antigen encounter remains poorly characterized. Here we show that critical properties of circulating primary memory CD8 T cells, including location, phenotype, cytokine production, maintenance, secondary proliferation, secondary memory generation potential, and mitochondrial function change with time after infection. Interestingly, phenotypic and functional alterations in the memory population are not due solely to shifts in the ratio of effector (CD62Llo) and central memory (CD62Lhi) cells, but also occur within defined CD62Lhi memory CD8 T cell subsets. CD62Lhi memory cells retain the ability to efficiently produce cytokines with time after infection. However, while it is was not formally tested whether changes in CD62Lhi memory CD8 T cells over time occur in a cell intrinsic manner or are due to selective death and/or survival, the gene expression profiles of CD62Lhi memory CD8 T cells change, phenotypic heterogeneity decreases, and mitochondrial function and proliferative capacity in either a lymphopenic environment or in response to antigen re-encounter increase with time. Importantly, and in accordance with their enhanced proliferative and metabolic capabilities, protection provided against chronic LCMV clone-13 infection increases over time for both circulating memory CD8 T cell populations and for CD62Lhi memory cells. Taken together, the data in this study reveal that memory CD8 T cells continue to change with time after infection and suggest that the outcome of vaccination strategies designed to elicit protective memory CD8 T cells using single or prime-boost immunizations depends upon the timing between antigen encounters.

Involvement of blood mononuclear cells in the infertility, age-associated diseases and cancer treatment

PubMed Central

Bukovsky, Antonin

2016-01-01

Blood mononuclear cells consist of T cells and monocyte derived cells. Beside immunity, the blood mononuclear cells belong to the complex tissue control system (TCS), where they exhibit morphostatic function by stimulating proliferation of tissue stem cells followed by cellular differentiation, that is stopped after attaining the proper functional stage, which differs among various tissue types. Therefore, the term immune and morphostatic system (IMS) should be implied. The TCS-mediated morphostasis also consists of vascular pericytes controlled by autonomic innervation, which is regulating the quantity of distinct tissues in vivo. Lack of proper differentiation of tissue cells by TCS causes either tissue underdevelopment, e.g., muscular dystrophy, or degenerative functional failures, e.g., type 1 diabetes and age-associated diseases. With the gradual IMS regression after 35 years of age the gonadal infertility develops, followed by a growing incidence of age-associated diseases and cancers. Without restoring an altered TCS function in a degenerative disease, the implantation of tissue-specific stem cells alone by regenerative medicine can not be successful. Transfused young blood could temporarily restore fertility to enable parenthood. The young blood could also temporarily alleviate aging diseases, and this can be extended by substances inducing IMS regeneration, like the honey bee propolis. The local and/or systemic use of honey bee propolis stopped hair and teeth loss, regressed varicose veins, improved altered hearing, and lowered high blood pressure and sugar levels. Complete regression of stage IV ovarian cancer with liver metastases after a simple elaborated immunotherapy is also reported. PMID:28074124

Cancer metabolism: fatty acid oxidation in the limelight

PubMed Central

Carracedo, Arkaitz; Cantley, Lewis C.; Pandolfi, Pier Paolo

2013-01-01

Warburg suggested that the alterations in metabolism that he observed in cancer cells were due to the malfunction of mitochondria. In the past decade, we have revisited this idea and reached a better understanding of the ‘metabolic switch’ in cancer cells, including the intimate and causal relationship between cancer genes and metabolic alterations, and their potential to be targeted for cancer treatment. However, the vast majority of the research into cancer metabolism has been limited to a handful of metabolic pathways, while other pathways have remained in the dark. This Progress article brings to light the important contribution of fatty acid oxidation to cancer cell function. PMID:23446547

Epigenetic regulation of gene expression in cancer: techniques, resources and analysis

PubMed Central

Kagohara, Luciane T; Stein-O’Brien, Genevieve L; Kelley, Dylan; Flam, Emily; Wick, Heather C; Danilova, Ludmila V; Easwaran, Hariharan; Favorov, Alexander V; Qian, Jiang; Gaykalova, Daria A; Fertig, Elana J

2018-01-01

Abstract Cancer is a complex disease, driven by aberrant activity in numerous signaling pathways in even individual malignant cells. Epigenetic changes are critical mediators of these functional changes that drive and maintain the malignant phenotype. Changes in DNA methylation, histone acetylation and methylation, noncoding RNAs, posttranslational modifications are all epigenetic drivers in cancer, independent of changes in the DNA sequence. These epigenetic alterations were once thought to be crucial only for the malignant phenotype maintenance. Now, epigenetic alterations are also recognized as critical for disrupting essential pathways that protect the cells from uncontrolled growth, longer survival and establishment in distant sites from the original tissue. In this review, we focus on DNA methylation and chromatin structure in cancer. The precise functional role of these alterations is an area of active research using emerging high-throughput approaches and bioinformatics analysis tools. Therefore, this review also describes these high-throughput measurement technologies, public domain databases for high-throughput epigenetic data in tumors and model systems and bioinformatics algorithms for their analysis. Advances in bioinformatics data that combine these epigenetic data with genomics data are essential to infer the function of specific epigenetic alterations in cancer. These integrative algorithms are also a focus of this review. Future studies using these emerging technologies will elucidate how alterations in the cancer epigenome cooperate with genetic aberrations during tumor initiation and progression. This deeper understanding is essential to future studies with epigenetics biomarkers and precision medicine using emerging epigenetic therapies. PMID:28968850

Integrative analyses of miRNA and proteomics identify potential biological pathways associated with onset of pulmonary fibrosis in the bleomycin rat model

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

Fukunaga, Satoki; Environmental Health Science Laboratory, Sumitomo Chemical Co., Ltd., 3-1-98 Kasugade-Naka, Konohana-ku, Osaka 554-8558; Kakehashi, Anna

To determine miRNAs and their predicted target proteins regulatory networks which are potentially involved in onset of pulmonary fibrosis in the bleomycin rat model, we conducted integrative miRNA microarray and iTRAQ-coupled LC-MS/MS proteomic analyses, and evaluated the significance of altered biological functions and pathways. We observed that alterations of miRNAs and proteins are associated with the early phase of bleomycin-induced pulmonary fibrosis, and identified potential target pairs by using ingenuity pathway analysis. Using the data set of these alterations, it was demonstrated that those miRNAs, in association with their predicted target proteins, are potentially involved in canonical pathways reflective ofmore » initial epithelial injury and fibrogenic processes, and biofunctions related to induction of cellular development, movement, growth, and proliferation. Prediction of activated functions suggested that lung cells acquire proliferative, migratory, and invasive capabilities, and resistance to cell death especially in the very early phase of bleomycin-induced pulmonary fibrosis. The present study will provide new insights for understanding the molecular pathogenesis of idiopathic pulmonary fibrosis. - Highlights: • We analyzed bleomycin-induced pulmonary fibrosis in the rat. • Integrative analyses of miRNA microarray and proteomics were conducted. • We determined the alterations of miRNAs and their potential target proteins. • The alterations may control biological functions and pathways in pulmonary fibrosis. • Our result may provide new insights of pulmonary fibrosis.« less

Integrated analysis of genetic, behavioral, and biochemical data implicates neural stem cell-induced changes in immunity, neurotransmission and mitochondrial function in Dementia with Lewy Body mice.

PubMed

Lakatos, Anita; Goldberg, Natalie R S; Blurton-Jones, Mathew

2017-03-10

We previously demonstrated that transplantation of murine neural stem cells (NSCs) can improve motor and cognitive function in a transgenic model of Dementia with Lewy Bodies (DLB). These benefits occurred without changes in human α-synuclein pathology and were mediated in part by stem cell-induced elevation of brain-derived neurotrophic factor (BDNF). However, instrastriatal NSC transplantation likely alters the brain microenvironment via multiple mechanisms that may synergize to promote cognitive and motor recovery. The underlying neurobiology that mediates such restoration no doubt involves numerous genes acting in concert to modulate signaling within and between host brain cells and transplanted NSCs. In order to identify functionally connected gene networks and additional mechanisms that may contribute to stem cell-induced benefits, we performed weighted gene co-expression network analysis (WGCNA) on striatal tissue isolated from NSC- and vehicle-injected wild-type and DLB mice. Combining continuous behavioral and biochemical data with genome wide expression via network analysis proved to be a powerful approach; revealing significant alterations in immune response, neurotransmission, and mitochondria function. Taken together, these data shed further light on the gene network and biological processes that underlie the therapeutic effects of NSC transplantation on α-synuclein induced cognitive and motor impairments, thereby highlighting additional therapeutic targets for synucleinopathies.

Loss of mTORC1 signaling alters pancreatic α cell mass and impairs glucagon secretion

PubMed Central

Bozadjieva, Nadejda; Dai, Xiao-Qing; Cummings, Kelsey; Gimeno, Jennifer; Powers, Alvin C.; Gittes, George K.; Rüegg, Markus A.; Hall, Michael N.; MacDonald, Patrick E.

2017-01-01

Glucagon plays a major role in the regulation of glucose homeostasis during fed and fasting states. However, the mechanisms responsible for the regulation of pancreatic α cell mass and function are not completely understood. In the current study, we identified mTOR complex 1 (mTORC1) as a major regulator of α cell mass and glucagon secretion. Using mice with tissue-specific deletion of the mTORC1 regulator Raptor in α cells (αRaptorKO), we showed that mTORC1 signaling is dispensable for α cell development, but essential for α cell maturation during the transition from a milk-based diet to a chow-based diet after weaning. Moreover, inhibition of mTORC1 signaling in αRaptorKO mice and in WT animals exposed to chronic rapamycin administration decreased glucagon content and glucagon secretion. In αRaptorKO mice, impaired glucagon secretion occurred in response to different secretagogues and was mediated by alterations in KATP channel subunit expression and activity. Additionally, our data identify the mTORC1/FoxA2 axis as a link between mTORC1 and transcriptional regulation of key genes responsible for α cell function. Thus, our results reveal a potential function of mTORC1 in nutrient-dependent regulation of glucagon secretion and identify a role for mTORC1 in controlling α cell–mass maintenance. PMID:29106387

Lipidomic approach to identify patterns in phospholipid profiles and define class differences in mammary epithelial and breast cancer cells.

PubMed

Dória, M Luísa; Cotrim, Zita; Macedo, Bárbara; Simões, Cláudia; Domingues, Pedro; Helguero, Luisa; Domingues, M Rosário

2012-06-01

Breast cancer is the leading cause of cancer-related deaths in women. Altered cellular functions of cancer cells lead to uncontrolled cellular growth and morphological changes. Cellular biomembranes are intimately involved in the regulation of cell signaling; however, they remain largely understudied. Phospholipids (PLs) are the main constituents of biological membranes and play important functional, structural and metabolic roles. The aim of this study was to establish if patterns in the PL profiles of mammary epithelial cells and breast cancer cells differ in relation to degree of differentiation and metastatic potential. For this purpose, PLs were analyzed using a lipidomic approach. In brief, PLs were extracted using Bligh and Dyer method, followed by a separation of PL classes by thin layer chromatography, and subsequent analysis by mass spectrometry (MS). Differences and similarities were found in the relative levels of PL content between mammary epithelial and breast cancer cells and between breast cancer cells with different levels of aggressiveness. When compared to the total PL content, phosphatidylcholine levels were reduced and lysophosphatydilcholines increased in the more aggressive cancer cells; while phosphatidylserine levels remained unchanged. MS analysis showed alterations in the classes of phosphatidylcholine, lysophosphatidylcholine, sphingomyelin, and phosphatidylinositides. In particular, the phosphatidylinositides, which are signaling molecules that affect proliferation, survival, and migration, showed dramatic alterations in their profile, where an increase of phosphatdylinositides saturated fatty acids chains and a decrease in C20 fatty acids in cancer cells compared with mammary epithelial cells was observed. At present, information about PL changes in cancer progression is lacking. Therefore, these data will be useful as a starting point to define possible PLs with prospective as biomarkers and disclose metabolic pathways with potential for therapy.

Alteration of the fast excitatory postsynaptic current by barium in voltage-clamped amphibian sympathetic ganglion cells.

PubMed Central

Connor, E. A.; Parsons, R. L.

1984-01-01

Barium-induced alterations in fast excitatory postsynaptic currents (e.p.s.cs) have been studied in voltage-clamped bullfrog sympathetic ganglion B cells. In the presence of 2-8 mM barium, e.p.s.c. decay was prolonged and in many cells the e.p.s.c. decay phase deviated from a single exponential function. The decay phase in these cases was more accurately described as the sum of two exponential functions. The frequency of occurrence of a complex decay increased both with increasing barium concentration and with hyperpolarization. Miniature e.p.s.c. decay also was prolonged in barium-treated cells. E.p.s.c. amplitude was not markedly affected by barium (2-8 mM) in cells voltage-clamped to -50 mV whereas at -90 mV there was a progressive increase in peak size with increasing barium concentration. In control cells the e.p.s.c.-voltage relationship was linear between -20 and -100 mV; however, this relationship became progressively non-linear with membrane hyperpolarization in barium-treated cells. The e.p.s.c. reversal potential was shifted to a more negative value in the presence of barium. There was a voltage-dependent increase in charge movement during the e.p.s.c. in barium-treated cells which was not present in control cells. We conclude that the voltage-dependent alteration in e.p.s.c. decay time course, peak amplitude and charge movement in barium-treated cells is due to a direct postsynaptic action of barium on the kinetics of receptor-channel gating in postganglionic sympathetic neurones. PMID:6333261

Structural and functional changes in acute liver injury.

PubMed Central

Smuckler, E A

1976-01-01

Carbon tetrachloride produces liver cell injury in a variety of animal species. The first structurally recognizable changes occur in the endoplasmic reticulum, with alteration in ribosome-membrane interactions. Later there is an increase in intracellular fat, and the formation of tangled nets of the ergastoplasm. At no time are there changes in mitochondria or single membrane limited bodies in cells with intact plasmalemma, although a relative increase in cell sap may appear. In dead cells (those with plasmalemma discontinuties) crystalline deposits of calcium phosphatase may be noted. Functional changes are related to the endoplasmic reticulum and the plasma membrane. An early decrease in protein synthesis takes place; an accumulation of neutral lipid is related to this change. Later alterations in the ergastoplasmic functions (e.g., mixed function oxidation) occurs. Carbon tetrachloride is not the active agent; rather, a product of its metabolism, probably the CC1, free radical, is. The mechanisms of injury include macromolecular adduction and peroxide propagation. A third possibility includes a cascade effect with the production of secondary and tertiary products, also toxic in nature, with the ability to produce more widespread damage to intracellular structures. Images FIGURE 1. FIGURE 2. FIGURE 3. FIGURE 4. FIGURE 5. FIGURE 6. FIGURE 7. FIGURE 11. PMID:1001290

Metabolic Plasticity in Cancer Cells: Reconnecting Mitochondrial Function to Cancer Control

PubMed Central

Ramanujan, V. Krishnan

2015-01-01

Anomalous increase in glycolytic activity defines one of the key metabolic alterations in cancer cells. A realization of this feature has led to critical advancements in cancer detection techniques such as positron emission tomography (PET) as well as a number of therapeutic avenues targeting the key glycolytic steps within a cancer cell. A normal healthy cell’s survival relies on a sensitive balance between the primordial glycolysis and a more regulated mitochondrial bioenergetics. The salient difference between these two bioenergetics pathways is that oxygen availability is an obligatory requirement for mitochondrial pathway while glycolysis can function without oxygen. Early observations that some cancer cells up-regulate glycolytic activity even in the presence of oxygen (aerobic glycolysis) led to a hypothesis that such an altered cancer cell metabolism stems from inherent mitochondrial dysfunction. While a general validity of this hypothesis is still being debated, a number of recent research efforts have yielded clarity on the physiological origins of this aerobic glycolysis phenotype in cancer cells. Building on these recent studies, we present a generalized scheme of cancer cell metabolism and propose a novel hypothesis that might rationalize new avenues of cancer intervention. PMID:26457230

Cytoskeletal stability and metabolic alterations in primary human macrophages in long-term microgravity.

PubMed

Tauber, Svantje; Lauber, Beatrice A; Paulsen, Katrin; Layer, Liliana E; Lehmann, Martin; Hauschild, Swantje; Shepherd, Naomi R; Polzer, Jennifer; Segerer, Jürgen; Thiel, Cora S; Ullrich, Oliver

2017-01-01

The immune system is one of the most affected systems of the human body during space flight. The cells of the immune system are exceptionally sensitive to microgravity. Thus, serious concerns arise, whether space flight associated weakening of the immune system ultimately precludes the expansion of human presence beyond the Earth's orbit. For human space flight, it is an urgent need to understand the cellular and molecular mechanisms by which altered gravity influences and changes the functions of immune cells. The CELLBOX-PRIME (= CellBox-Primary Human Macrophages in Microgravity Environment) experiment investigated for the first time microgravity-associated long-term alterations in primary human macrophages, one of the most important effector cells of the immune system. The experiment was conducted in the U.S. National Laboratory on board of the International Space Station ISS using the NanoRacks laboratory and Biorack type I standard CELLBOX EUE type IV containers. Upload and download were performed with the SpaceX CRS-3 and the Dragon spaceship on April 18th, 2014 / May 18th, 2014. Surprisingly, primary human macrophages exhibited neither quantitative nor structural changes of the actin and vimentin cytoskeleton after 11 days in microgravity when compared to 1g controls. Neither CD18 or CD14 surface expression were altered in microgravity, however ICAM-1 expression was reduced. The analysis of 74 metabolites in the cell culture supernatant by GC-TOF-MS, revealed eight metabolites with significantly different quantities when compared to 1g controls. In particular, the significant increase of free fucose in the cell culture supernatant was associated with a significant decrease of cell surface-bound fucose. The reduced ICAM-1 expression and the loss of cell surface-bound fucose may contribute to functional impairments, e.g. the activation of T cells, migration and activation of the innate immune response. We assume that the surprisingly small and non-significant cytoskeletal alterations represent a stable "steady state" after adaptive processes are initiated in the new microgravity environment. Due to the utmost importance of the human macrophage system for the elimination of pathogens and the clearance of apoptotic cells, its apparent robustness to a low gravity environment is crucial for human health and performance during long-term space missions.

Cytoskeletal stability and metabolic alterations in primary human macrophages in long-term microgravity

PubMed Central

Tauber, Svantje; Lauber, Beatrice A.; Paulsen, Katrin; Layer, Liliana E.; Lehmann, Martin; Hauschild, Swantje; Shepherd, Naomi R.; Polzer, Jennifer; Segerer, Jürgen; Thiel, Cora S.

2017-01-01

The immune system is one of the most affected systems of the human body during space flight. The cells of the immune system are exceptionally sensitive to microgravity. Thus, serious concerns arise, whether space flight associated weakening of the immune system ultimately precludes the expansion of human presence beyond the Earth's orbit. For human space flight, it is an urgent need to understand the cellular and molecular mechanisms by which altered gravity influences and changes the functions of immune cells. The CELLBOX-PRIME (= CellBox-Primary Human Macrophages in Microgravity Environment) experiment investigated for the first time microgravity-associated long-term alterations in primary human macrophages, one of the most important effector cells of the immune system. The experiment was conducted in the U.S. National Laboratory on board of the International Space Station ISS using the NanoRacks laboratory and Biorack type I standard CELLBOX EUE type IV containers. Upload and download were performed with the SpaceX CRS-3 and the Dragon spaceship on April 18th, 2014 / May 18th, 2014. Surprisingly, primary human macrophages exhibited neither quantitative nor structural changes of the actin and vimentin cytoskeleton after 11 days in microgravity when compared to 1g controls. Neither CD18 or CD14 surface expression were altered in microgravity, however ICAM-1 expression was reduced. The analysis of 74 metabolites in the cell culture supernatant by GC–TOF–MS, revealed eight metabolites with significantly different quantities when compared to 1g controls. In particular, the significant increase of free fucose in the cell culture supernatant was associated with a significant decrease of cell surface–bound fucose. The reduced ICAM-1 expression and the loss of cell surface–bound fucose may contribute to functional impairments, e.g. the activation of T cells, migration and activation of the innate immune response. We assume that the surprisingly small and non-significant cytoskeletal alterations represent a stable “steady state” after adaptive processes are initiated in the new microgravity environment. Due to the utmost importance of the human macrophage system for the elimination of pathogens and the clearance of apoptotic cells, its apparent robustness to a low gravity environment is crucial for human health and performance during long-term space missions. PMID:28419128

Ageing alters the impact of nutrition on immune function.

PubMed

Yaqoob, Parveen

2017-08-01

Immunosenescence during ageing is a major challenge which weakens the ability of older individuals to respond to infection or vaccination. There has been much interest in dietary strategies to improve immunity in older people, but there is an assumption that modulation of the immune response in older people will be based on the same principles as for younger adults. Recent evidence suggests that ageing fundamentally alters the impact of nutrition on immune function. As a result, interpretation of data from studies investigating the impact of diet on immune function is highly dependent on subject age. Study design is critically important when investigating the efficacy of dietary components, and most studies involving older people include rigorous inclusion/exclusion criteria based on medical history, laboratory tests, general health status and often nutritional status. However, immunological status is rarely accounted for, but can vary significantly, even amongst healthy older people. There are several clear examples of age-related changes in immune cell composition, phenotype and/or function, which can directly alter the outcome of an intervention. This review uses two case studies to illustrate how the effects of n-3 PUFA and probiotics differ markedly in young v. older subjects. Evidence from both suggests that baseline differences in immunosenescence influence the outcome of an intervention, highlighting the need for detailed immunological characterisation of subjects prior to interventions. Finally, future work elucidating alterations in metabolic regulation within cells of the immune system as a result of ageing may be important in understanding the impact of diet on immune function in older people.

The human Nav1.5 F1486 deletion associated with long QT syndrome leads to impaired sodium channel inactivation and reduced lidocaine sensitivity

PubMed Central

Song, Weihua; Xiao, Yucheng; Chen, Hanying; Ashpole, Nicole M; Piekarz, Andrew D; Ma, Peilin; Hudmon, Andy; Cummins, Theodore R; Shou, Weinian

2012-01-01

The deletion of phenylalanine 1486 (F1486del) in the human cardiac voltage-gated sodium channel (hNav1.5) is associated with fatal long QT (LQT) syndrome. In this study we determined how F1486del impairs the functional properties of hNav1.5 and alters action potential firing in heterologous expression systems (human embryonic kidney (HEK) 293 cells) and their native cardiomyocyte background. Cells expressing hNav1.5-F1486del exhibited a loss-of-function alteration, reflected by an 80% reduction of peak current density, and several gain-of-function alterations, including reduced channel inactivation, enlarged window current, substantial augmentation of persistent late sodium current and an increase in ramp current. We also observed substantial action potential duration (APD) prolongation and prominent early afterdepolarizations (EADs) in neonatal cardiomyocytes expressing the F1486del channels, as well as in computer simulations of myocyte activity. In addition, lidocaine sensitivity was dramatically reduced, which probably contributed to the poor therapeutic outcome observed in the patient carrying the hNav1.5-F1486del mutation. Therefore, despite the significant reduction in peak current density, the F1486del mutation also leads to substantial gain-of-function alterations that are sufficient to cause APD prolongation and EADs, the predominant characteristic of LQTs. These data demonstrate that hNav1.5 mutations can have complex functional consequences and highlight the importance of identifying the specific molecular defect when evaluating potential treatments for individuals with prolonged QT intervals. PMID:22826127

Effects of real or simulated microgravity on plant cell growth and proliferation

NASA Astrophysics Data System (ADS)

Medina, Francisco Javier; Manzano, Ana Isabel; Herranz, Raul; Dijkstra, Camelia; Larkin, Oliver; Hill, Richard; Carnero-Díaz, Eugénie; van Loon, Jack J. W. A.; Anthony, Paul; Davey, Michael R.; Eaves, Laurence

Experiments on seed germination and seedling growth performed in real microgravity on the International Space Station and in different facilities for simulating microgravity in Earth-based laboratories (Random Positioning Machine and Magnetic Levitation), have provided evidence that the absence of gravity (or the artificial compensation of the gravity vector) results in the uncoupling of cell growth and proliferation in root meristematic cells. These are two essential cellular functions that support plant growth and development, which are strictly coordinated under normal ground gravity conditions. Under conditions of altered gravity, we observe that cell proliferation is enhanced, whereas cell growth is reduced, according to different morphometric, cytological and immunocytochemical parameters. Since coordination of cell growth and proliferation are major features of meristematic cells, this observed uncoupling represents a major stress condition for these cells, inducing major alterations in the pattern of plant development. Moreover, the expression of the cyclin B1 gene, a regulator of the entry into mitosis and normally used as an indicator of cell proliferation, appears reduced in the smaller and more actively proliferating cells of samples grown under the conditions of our experiments. These results are compatible with an alteration of the regulation of the cell cycle, producing a shorter G2 period. Interestingly, while cyclin B1 expression is depleted in these conditions in root meristematic cells, it is enhanced in cotyledons of the same seedlings, as shown by qPCR and by the expression of the gus reporter gene. It is known that regulation of root growth (including regulation of root meristematic activity) is driven mainly by auxin, whereas cytokinin is the key hormone regulating cotyledon growth. Therefore, our results indicate a major role of auxin in the sensitivity to altered gravity of root meristematic cells. Auxin is crucial in maintaining the coupling of cell growth and proliferation under normal conditions and it should have a decisive influence in the uncoupling of these processes under altered gravity. Experiments to detect auxin distribution in roots under altered gravity produced by diamagnetic levitation have shown that the lateral balanced distribution of the growth regulator in the root cap is altered slightly and that the total concentration of the auxin detected in root tips is somewhat reduced. These effects are independent of the orientation of statoliths in columella cells.

Plant Growth Biophysics: the Basis for Growth Asymmetry Induced by Gravity

NASA Technical Reports Server (NTRS)

Cosgrove, D.

1985-01-01

The identification and quantification of the physical properties altered by gravity when plant stems grow upward was studied. Growth of the stem in vertical and horizontal positions was recorded by time lapse photography. A computer program that uses a cubic spline fitting algorithm was used to calculate the growth rate and curvature of the stem as a function of time. Plant stems were tested to ascertain whether cell osmotic pressure was altered by gravity. A technique for measuring the yielding properties of the cell wall was developed.

Cell Calcium and the Control of Membrane Transport. Annual Symposium of the Society of General Physiologists (40th) Held in Woods Hole, Massachusetts on September 3-7, 1986.

DTIC Science & Technology

1986-01-01

physiological functions: to alter the composition of the cell surface, for instance, by the insertion of receptors, channels, and pumps, and to release into the...localized alterations in lipid composition might serve to facilitate fusion under some circumstances, the involvement of proteins specialized for...594. Reuter. H., and N. Seitz. 1968. The dependence of Ca2* efllux from cardiac muscle on temperature and external ion composition . Journal o/Phywidoo

CLIC4 Moves Into Nucleus to Stabilize Anti-Growth Signal | Center for Cancer Research

Cancer.gov

In cancer, the delicate balance of signaling pathways that control cell growth and function is disrupted. One signaling pathway commonly altered in cancer is the TGF-beta pathway. TGF-beta significantly inhibits growth of normal cells, particularly epithelial cells. Many cancer cells have developed ways to bypass one or more steps of this pathway in order to achieve uncontrolled growth.

CLIC4 Moves Into Nucleus to Stabilize Anti-Growth Signal | Center for Cancer Research

Cancer.gov

In cancer, the delicate balance of signaling pathways that control cell growth and function is disrupted. One signaling pathway commonly altered in cancer is the TGF-beta pathway. TGF-beta significantly inhibits growth of normal cells, particularly epithelial cells. Many cancer cells have developed ways to bypass one or more steps of this pathway in order to achieve

[Impact of cell phone radiation on male reproduction].

PubMed

Kang, Ning; Shang, Xue-Jun; Huang, Yu-Feng

2010-11-01

With the popularized use cell phones, more and more concern has been aroused over the effects of their radiation on human health, particularly on male reproduction. Cell phone radiation may cause structural and functional injuries of the testis, alteration of semen parameters, reduction of epididymal sperm concentration and decline of male fertility. This article presents an overview on the impact of cell phone radiation on male reproduction.

The Pivotal Role of Airway Smooth Muscle in Asthma Pathophysiology

PubMed Central

Ozier, Annaïg; Allard, Benoit; Bara, Imane; Girodet, Pierre-Olivier; Trian, Thomas; Marthan, Roger; Berger, Patrick

2011-01-01

Asthma is characterized by the association of airway hyperresponsiveness (AHR), inflammation, and remodelling. The aim of the present article is to review the pivotal role of airway smooth muscle (ASM) in the pathophysiology of asthma. ASM is the main effector of AHR. The mechanisms of AHR in asthma may involve a larger release of contractile mediators and/or a lower release of relaxant mediators, an improved ASM cell excitation/contraction coupling, and/or an alteration in the contraction/load coupling. Beyond its contractile function, ASM is also involved in bronchial inflammation and remodelling. Whereas ASM is a target of the inflammatory process, it can also display proinflammatory and immunomodulatory functions, through its synthetic properties and the expression of a wide range of cell surface molecules. ASM remodelling represents a key feature of asthmatic bronchial remodelling. ASM also plays a role in promoting complementary airway structural alterations, in particular by its synthetic function. PMID:22220184

Alterations in the adenosine metabolism and CD39/CD73 adenosinergic machinery cause loss of Treg cell function and autoimmunity in ADA-deficient SCID

PubMed Central

Sauer, Aisha V.; Brigida, Immacolata; Carriglio, Nicola; Jofra Hernandez, Raisa; Scaramuzza, Samantha; Clavenna, Daniela; Sanvito, Francesca; Poliani, Pietro L.; Gagliani, Nicola; Carlucci, Filippo; Tabucchi, Antonella; Roncarolo, Maria Grazia; Traggiai, Elisabetta; Villa, Anna

2012-01-01

Adenosine acts as anti-inflammatory mediator on the immune system and has been described in regulatory T cell (Treg)–mediated suppression. In the absence of adenosine deaminase (ADA), adenosine and other purine metabolites accumulate, leading to severe immunodeficiency with recurrent infections (ADA-SCID). Particularly ADA-deficient patients with late-onset forms and after enzyme replacement therapy (PEG-ADA) are known to manifest immune dysregulation. Herein we provide evidence that alterations in the purine metabolism interfere with Treg function, thereby contributing to autoimmune manifestations in ADA deficiency. Tregs isolated from PEG-ADA–treated patients are reduced in number and show decreased suppressive activity, whereas they are corrected after gene therapy. Untreated murine ADA−/− Tregs show alterations in the plasma membrane CD39/CD73 ectonucleotidase machinery and limited suppressive activity via extracellular adenosine. PEG-ADA–treated mice developed multiple autoantibodies and hypothyroidism in contrast to mice treated with bone marrow transplantation or gene therapy. Tregs isolated from PEG-ADA–treated mice lacked suppressive activity, suggesting that this treatment interferes with Treg functionality. The alterations in the CD39/CD73 adenosinergic machinery and loss of function in ADA-deficient Tregs provide new insights into a predisposition to autoimmunity and the underlying mechanisms causing defective peripheral tolerance in ADA-SCID. Trials were registered at www.clinicaltrials.gov as NCT00598481/NCT00599781. PMID:22184407

Lactobacillus johnsonii Supplementation Attenuates Respiratory Viral Infection via Metabolic Reprogramming and Immune Cell Modulation

PubMed Central

Fonseca, Wendy; Lucey, Kaitlyn; Jang, Sihyug; Fujimura, Kei E.; Rasky, Andrew; Ting, Hung-An; Petersen, Julia; Johnson, Christine C.; Boushey, Homer A.; Zoratti, Edward; Ownby, Dennis R.; Levine, Albert M.; Bobbit, Kevin R.

2017-01-01

Summary Regulation of respiratory mucosal immunity by microbial-derived metabolites has been a proposed mechanism that may provide airway protection. Here we examine the effect of oral Lactobacillus johnsonii-supplementation on metabolic and immune response dynamics during respiratory syncytial virus (RSV) infection. L. johnsonii-supplementation reduced airway Th2 cytokines, dendritic cell function, increased T-regulatory cells, and was associated with a reprogrammed circulating metabolic environment, including docosahexanoic acid (DHA) enrichment. RSV-infected bone-marrow derived dendritic cells (BMDC) from L. johnsonii-supplemented mice had altered cytokine secretion, reduced expression of co-stimulatory molecules, and modified CD4+ T cell cytokines. This was replicated upon co-incubation of wild-type BMDCs with either plasma from L. johnsonii-supplemented mice, or DHA. Finally, airway transfer of BMDCs from L. johnsonii-supplemented mice, or with wild-type derived BMDCs pre-treated with plasma from L. johnsonii-supplemented mice, reduced airway pathologic responses to infection in recipient animals. Thus, L. johnsonii-supplementation mediates airway mucosal protection via immunomodulatory metabolites and altered immune function. PMID:28295020

Molecular targets and signaling pathways regulated by nuclear translocation of syndecan-1.

PubMed

Szatmári, Tünde; Mundt, Filip; Kumar-Singh, Ashish; Möbus, Lena; Ötvös, Rita; Hjerpe, Anders; Dobra, Katalin

2017-12-08

The cell-surface heparan sulfate proteoglycan syndecan-1 is important for tumor cell proliferation, migration, and cell cycle regulation in a broad spectrum of malignancies. Syndecan-1, however, also translocates to the cell nucleus, where it might regulate various molecular functions. We used a fibrosarcoma model to dissect the functions of syndecan-1 related to the nucleus and separate them from functions related to the cell-surface. Nuclear translocation of syndecan-1 hampered the proliferation of fibrosarcoma cells compared to the mutant lacking nuclear localization signal. The growth inhibitory effect of nuclear syndecan-1 was accompanied by significant accumulation of cells in the G0/G1 phase, which indicated a possible G1/S phase arrest. We implemented multiple, unsupervised global transcriptome and proteome profiling approaches and combined them with functional assays to disclose the molecular mechanisms that governed nuclear translocation and its related functions. We identified genes and pathways related to the nuclear compartment with network enrichment analysis of the transcriptome and proteome. The TGF-β pathway was activated by nuclear syndecan-1, and three genes were significantly altered with the deletion of nuclear localization signal: EGR-1 (early growth response 1), NEK11 (never-in-mitosis gene a-related kinase 11), and DOCK8 (dedicator of cytokinesis 8). These candidate genes were coupled to growth and cell-cycle regulation. Nuclear translocation of syndecan-1 influenced the activity of several other transcription factors, including E2F, NFκβ, and OCT-1. The transcripts and proteins affected by syndecan-1 showed a striking overlap in their corresponding biological processes. These processes were dominated by protein phosphorylation and post-translation modifications, indicative of alterations in intracellular signaling. In addition, we identified molecules involved in the known functions of syndecan-1, including extracellular matrix organization and transmembrane transport. Collectively, abrogation of nuclear translocation of syndecan-1 resulted in a set of changes clustering in distinct patterns, which highlighted the functional importance of nuclear syndecan-1 in hampering cell proliferation and the cell cycle. This study emphasizes the importance of the localization of syndecan-1 when considering its effects on tumor cell fate.

Cell biology of sarcomeric protein engineering: disease modeling and therapeutic potential.

PubMed

Thompson, Brian R; Metzger, Joseph M

2014-09-01

The cardiac sarcomere is the functional unit for myocyte contraction. Ordered arrays of sarcomeric proteins, held in stoichiometric balance with each other, respond to calcium to coordinate contraction and relaxation of the heart. Altered sarcomeric structure-function underlies the primary basis of disease in multiple acquired and inherited heart disease states. Hypertrophic and restrictive cardiomyopathies are caused by inherited mutations in sarcomeric genes and result in altered contractility. Ischemia-mediated acidosis directly alters sarcomere function resulting in decreased contractility. In this review, we highlight the use of acute genetic engineering of adult cardiac myocytes through stoichiometric replacement of sarcomeric proteins in these disease states with particular focus on cardiac troponin I. Stoichiometric replacement of disease causing mutations has been instrumental in defining the molecular mechanisms of hypertrophic and restrictive cardiomyopathy in a cellular context. In addition, taking advantage of stoichiometric replacement through gene therapy is discussed, highlighting the ischemia-resistant histidine-button, A164H cTnI. Stoichiometric replacement of sarcomeric proteins offers a potential gene therapy avenue to replace mutant proteins, alter sarcomeric responses to pathophysiologic insults, or neutralize altered sarcomeric function in disease. © 2014 Wiley Periodicals, Inc.

Probing plasmodesmata function with biochemical inhibitors.

PubMed

White, Rosemary G

2015-01-01

To investigate plasmodesmata (PD) function, a useful technique is to monitor the effect on cell-to-cell transport of applying an inhibitor of a physiological process, protein, or other cell component of interest. Changes in PD transport can then be monitored in one of several ways, most commonly by measuring the cell-to-cell movement of fluorescent tracer dyes or of free fluorescent proteins. Effects on PD structure can be detected in thin sections of embedded tissue observed using an electron microscope, most commonly a Transmission Electron Microscope (TEM). This chapter outlines commonly used inhibitors, methods for treating different tissues, how to detect altered cell-to-cell transport and PD structure, and important caveats.

Opioids and the immune system: what is their mechanism of action?

PubMed Central

Eisenstein, Toby K

2011-01-01

There is a significant amount of literature showing that morphine and other opioids modulate immune responses. The findings support many mechanisms by which this may occur. In vitro experiments provide evidence for direct actions of opioids on immune cells using a variety of functional end points. When these drugs are given in vivo, a plethora of immune parameters are also altered. The paper in this issue of the journal by Zhang et al. provides new information on morphine alteration of immune cell subsets in the spleen and thymus of mice and the potential role of glucocorticoids in these observed phenomena. This Commentary reviews the in vitro activities of morphine on leucocytes, as well as other documented mechanisms by which morphine can alter immune function in vivo. LINKED ARTICLE This article is a commentary on Zhang et al., pp. 1829–1844 of this issue. To view this paper visit http://dx.doi.org/10.1111/j.1476-5381.2011.01475.x PMID:21627636

Genetic Alterations of the Thrombopoietin/MPL/JAK2 Axis Impacting Megakaryopoiesis.

PubMed

Plo, Isabelle; Bellanné-Chantelot, Christine; Mosca, Matthieu; Mazzi, Stefania; Marty, Caroline; Vainchenker, William

2017-01-01

Megakaryopoiesis is an original and complex cell process which leads to the formation of platelets. The homeostatic production of platelets is mainly regulated and controlled by thrombopoietin (TPO) and the TPO receptor (MPL)/JAK2 axis. Therefore, any hereditary or acquired abnormality affecting this signaling axis can result in thrombocytosis or thrombocytopenia. Thrombocytosis can be due to genetic alterations that affect either the intrinsic MPL signaling through gain-of-function (GOF) activity ( MPL, JAK2, CALR ) and loss-of-function (LOF) activity of negative regulators ( CBL, LNK ) or the extrinsic MPL signaling by THPO GOF mutations leading to increased TPO synthesis. Alternatively, thrombocytosis may paradoxically result from mutations of MPL leading to an abnormal MPL trafficking, inducing increased TPO levels by alteration of its clearance. In contrast, thrombocytopenia can also result from LOF THPO or MPL mutations, which cause a complete defect in MPL trafficking to the cell membrane, impaired MPL signaling or stability, defects in the TPO/MPL interaction, or an absence of TPO production.

Genetic Alterations of the Thrombopoietin/MPL/JAK2 Axis Impacting Megakaryopoiesis

PubMed Central

Plo, Isabelle; Bellanné-Chantelot, Christine; Mosca, Matthieu; Mazzi, Stefania; Marty, Caroline; Vainchenker, William

2017-01-01

Megakaryopoiesis is an original and complex cell process which leads to the formation of platelets. The homeostatic production of platelets is mainly regulated and controlled by thrombopoietin (TPO) and the TPO receptor (MPL)/JAK2 axis. Therefore, any hereditary or acquired abnormality affecting this signaling axis can result in thrombocytosis or thrombocytopenia. Thrombocytosis can be due to genetic alterations that affect either the intrinsic MPL signaling through gain-of-function (GOF) activity (MPL, JAK2, CALR) and loss-of-function (LOF) activity of negative regulators (CBL, LNK) or the extrinsic MPL signaling by THPO GOF mutations leading to increased TPO synthesis. Alternatively, thrombocytosis may paradoxically result from mutations of MPL leading to an abnormal MPL trafficking, inducing increased TPO levels by alteration of its clearance. In contrast, thrombocytopenia can also result from LOF THPO or MPL mutations, which cause a complete defect in MPL trafficking to the cell membrane, impaired MPL signaling or stability, defects in the TPO/MPL interaction, or an absence of TPO production. PMID:28955303

The expanding universe of neurotrophic factors: therapeutic potential in aging and age-associated disorders.

PubMed

Lanni, C; Stanga, S; Racchi, M; Govoni, S

2010-01-01

Multiple molecular, cellular, structural and functional changes occur in the brain during aging. Neural cells may respond to these changes adaptively by employing multiple mechanisms in order to maintain the integrity of nerve cell circuits and to facilitate responses to environmental demands. Otherwise, they may succumb to neurodegenerative cascades that result in disorders such as Alzheimer's and Parkinson's diseases. An important role in this balancement is played by neurotrophic factors, which are central to many aspects of nervous system function since they regulate the development, maintenance and survival of neurons and neuron-supporting cells such as glia and oligodendrocytes. A vast amount of evidence indicates that alterations in levels of neurotrophic factors or their receptors can lead to neuronal death and contribute to aging as well as to the pathogenesis of diseases of abnormal trophic support (such as neurodegenerative diseases and depression) and diseases of abnormal excitability (such as epilepsy and central pain sensitization). Cellular and molecular mechanisms by which neurotrophic factors may influence cell survival and excitability are also critically examined to provide novel concepts and targets for the treatment of physiological changes bearing detrimental functional alterations and of different diseases affecting the central nervous system during aging.

Simulated hypogravity impairs the angiogenic response of endothelium by up-regulating apoptotic signals

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

Morbidelli, Lucia; Monici, Monica; Marziliano, Nicola

Health hazards in astronauts are represented by cardiovascular problems and impaired bone healing. These disturbances are characterized by a common event, the loss of function by vascular endothelium, leading to impaired angiogenesis. We investigated whether the exposure of cultured endothelial cells to hypogravity condition could affect their behaviour in terms of functional activity, biochemical responses, morphology, and gene expression. Simulated hypogravity conditions for 72 h produced a reduction of cell number. Genomic analysis of endothelial cells exposed to hypogravity revealed that proapoptotic signals increased, while antiapoptotic and proliferation/survival genes were down-regulated by modelled low gravity. Activation of apoptosis was accompaniedmore » by morphological changes with mitochondrial disassembly and organelles/cytoplasmic NAD(P)H redistribution, as evidenced by autofluorescence analysis. In this condition cells were not able to respond to angiogenic stimuli in terms of migration and proliferation. Our study documents functional, morphological, and transcription alterations in vascular endothelium exposed to simulated low gravity conditions, thus providing insights on the occurrence of vascular tissue dysregulation in crewmen during prolonged space flights. Moreover, the alteration of vascular endothelium can intervene as a concause in other systemic effects, like bone remodelling, observed in weightlessness.« less

Overexpression of B-cell lymphoma 6 alters gene expression profile in a myeloma cell line and is associated with decreased DNA damage response.

PubMed

Tahara, Kenichi; Takizawa, Makiko; Yamane, Arito; Osaki, Yohei; Ishizaki, Takuma; Mitsui, Takeki; Yokohama, Akihiko; Saitoh, Takayuki; Tsukamoto, Norifumi; Matsumoto, Morio; Murakami, Hirokazu; Nojima, Yoshihisa; Handa, Hiroshi

2017-08-01

B-cell lymphoma 6 (BCL6) attenuates DNA damage response (DDR) through gene repression and facilitates tolerance to genomic instability during immunoglobulin affinity maturation in germinal center (GC) B cells. Although BCL6 expression is repressed through normal differentiation of GC B cells into plasma cells, a recent study showed the ectopic expression of BCL6 in primary multiple myeloma (MM) cells. However, the functional roles of BCL6 in MM cells are largely unknown. Here, we report that overexpression of BCL6 in a MM cell line, KMS12PE, induced transcriptional repression of ataxia telangiectasia mutated (ATM), a DDR signaling kinase, which was associated with a reduction in γH2AX formation after DNA damage. In contrast, transcription of known targets of BCL6 in GC B cells was not affected, suggesting a cell type-specific function of BCL6. To further investigate the effects of BCL6 overexpression on the MM cell line, we undertook mRNA sequence analysis and found an upregulation in the genomic mutator activation-induced cytidine deaminase (AID) with alteration in the gene expression profile, which is suggestive of de-differentiation from plasma cells. Moreover, interleukin-6 exposure to KMS12PE led to upregulation of BCL6 and AID, downregulation of ATM, and attenuation of DDR, which were consistent with the effects of BCL6 overexpression in this MM cell line. Taken together, these results indicated that overexpression of BCL6 alters gene expression profile and confers decreased DDR in MM cells. This phenotypic change could be reproduced by interleukin-6 stimulation, suggesting an important role of external stimuli in inducing genomic instability, which is a hallmark of MM cells. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Downregulation of CXCR4 Expression and Functionality After Zoledronate Exposure in Canine Osteosarcoma.

PubMed

Byrum, M L; Pondenis, H C; Fredrickson, R L; Wycislo, K L; Fan, T M

2016-07-01

The establishment and progression of metastases remains the life-limiting factor for dogs diagnosed with osteosarcoma (OS). The pattern of metastases is likely regulated through interactions between chemokine receptors and chemokines, and perturbations in these signaling cascades responsible for cytoskeletal organization and directional migration have the potential to alter metastatic cell trafficking behaviors. Zoledronate will impair directional migration of OS cells through downregulation of chemokine (C-X-C motif) receptor 4 (CXCR4) expression and functionality. Nineteen archived tumor specimens and plasma from 20 dogs with OS. Prospectively, the expressions of CXCR4 were studied in OS cell lines and spontaneous tumor samples. The effect of zoledronate on CXCR4 expression and functionality was investigated by characterizing responses in 3 OS cell lines. In 19 OS specimens and 20 dogs with OS, changes in CXCR4 expression and circulating CXCR4 concentrations were characterized in response to zoledronate therapy respectively. All canine OS cells express CXCR4, and zoledronate reduces CXCR4 expression and functionality by 27.7% (P < .0001), through augmented proteasome degradation and reduced prenylation of heterotrimeric G-proteins in 33% of tumor cell lines evaluated. In OS-bearing dogs, zoledronate reduces CXCR4 expressions by 40% within the primary tumor compared to untreated controls (P = .03) and also decreases the circulating concentrations of CXCR4 in 18 of 20 dogs with OS. Zoledronate can alter CXCR4 expression and functionality in OS cells, and consequent perturbations in CXCR4 intracellular signaling cascades might influence patterns of metastases. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Somatostatin-Positive Gamma-Aminobutyric Acid Interneuron Deficits in Depression: Cortical Microcircuit and Therapeutic Perspectives.

PubMed

Fee, Corey; Banasr, Mounira; Sibille, Etienne

2017-10-15

The functional integration of external and internal signals forms the basis of information processing and is essential for higher cognitive functions. This occurs in finely tuned cortical microcircuits whose functions are balanced at the cellular level by excitatory glutamatergic pyramidal neurons and inhibitory gamma-aminobutyric acidergic (GABAergic) interneurons. The balance of excitation and inhibition, from cellular processes to neural network activity, is characteristically disrupted in multiple neuropsychiatric disorders, including major depressive disorder (MDD), bipolar disorder, anxiety disorders, and schizophrenia. Specifically, nearly 3 decades of research demonstrate a role for reduced inhibitory GABA level and function across disorders. In MDD, recent evidence from human postmortem and animal studies suggests a selective vulnerability of GABAergic interneurons that coexpress the neuropeptide somatostatin (SST). Advances in cell type-specific molecular genetics have now helped to elucidate several important roles for SST interneurons in cortical processing (regulation of pyramidal cell excitatory input) and behavioral control (mood and cognition). Here, we review evidence for altered inhibitory function arising from GABAergic deficits across disorders and specifically in MDD. We then focus on properties of the cortical microcircuit, where SST-positive GABAergic interneuron deficits may disrupt functioning in several ways. Finally, we discuss the putative origins of SST cell deficits, as informed by recent research, and implications for therapeutic approaches. We conclude that deficits in SST interneurons represent a contributing cellular pathology and therefore a promising target for normalizing altered inhibitory function in MDD and other disorders with reduced SST cell and GABA functions. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Alcohol-Induced Molecular Dysregulation in Human Embryonic Stem Cell-Derived Neural Precursor Cells

PubMed Central

Kim, Yi Young; Roubal, Ivan; Lee, Youn Soo; Kim, Jin Seok; Hoang, Michael; Mathiyakom, Nathan; Kim, Yong

2016-01-01

Adverse effect of alcohol on neural function has been well documented. Especially, the teratogenic effect of alcohol on neurodevelopment during embryogenesis has been demonstrated in various models, which could be a pathologic basis for fetal alcohol spectrum disorders (FASDs). While the developmental defects from alcohol abuse during gestation have been described, the specific mechanisms by which alcohol mediates these injuries have yet to be determined. Recent studies have shown that alcohol has significant effect on molecular and cellular regulatory mechanisms in embryonic stem cell (ESC) differentiation including genes involved in neural development. To test our hypothesis that alcohol induces molecular alterations during neural differentiation we have derived neural precursor cells from pluripotent human ESCs in the presence or absence of ethanol treatment. Genome-wide transcriptomic profiling identified molecular alterations induced by ethanol exposure during neural differentiation of hESCs into neural rosettes and neural precursor cell populations. The Database for Annotation, Visualization and Integrated Discovery (DAVID) functional analysis on significantly altered genes showed potential ethanol’s effect on JAK-STAT signaling pathway, neuroactive ligand-receptor interaction, Toll-like receptor (TLR) signaling pathway, cytokine-cytokine receptor interaction and regulation of autophagy. We have further quantitatively verified ethanol-induced alterations of selected candidate genes. Among verified genes we further examined the expression of P2RX3, which is associated with nociception, a peripheral pain response. We found ethanol significantly reduced the level of P2RX3 in undifferentiated hESCs, but induced the level of P2RX3 mRNA and protein in hESC-derived NPCs. Our result suggests ethanol-induced dysregulation of P2RX3 along with alterations in molecules involved in neural activity such as neuroactive ligand-receptor interaction may be a molecular event associated with alcohol-related peripheral neuropathy of an enhanced nociceptive response. PMID:27682028

LncRNA NNT-AS1 promotes the proliferation, and invasion of lung cancer cells via regulating miR-129-5p expression.

PubMed

Shen, Qin; Jiang, Yongjie

2018-05-29

Lung cancer is the leading cause of cancer related-deaths worldwide. Long non-coding RNAs (lncRNAs) are identified as important therapeutic targets in treatment of lung cancer. However, the roles of NNT-AS1 in lung cancer remain unclear. In the present study, we showed that the expression of NNT-AS1 was upregulated in non-small cell lung cancer (NSCLC) tissues and cell lines. High NNT-AS1 expression was associated with advanced tumor stage, and lymph node metastasis of NSCLC patients. In vitro function assays showed that NNT-AS1 inhibition could significantly reduce lung cancer cells proliferation and invasion ability. Then, we identified that NNT-AS1 could function as a competing endogenous RNA (ceRNA) by sponging miR-129-5p in lung cancer. In addition, we showed that alteration in cell proliferation and invasion caused by NNT-AS1 downregulation could be rescued by miR-129-5p inhibitors. Thus, our study indicated that lncRNA NNT-AS1 exerted functions in NSCLC via altering NNT-AS1/miR-129-5p axis which provided a novel therapeutic target for lung cancer treatment. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Bioenergetic Impairment in Congenital Muscular Dystrophy Type 1A and Leigh Syndrome Muscle Cells

PubMed Central

Fontes-Oliveira, Cibely C.; Steinz, Maarten; Schneiderat, Peter; Mulder, Hindrik; Durbeej, Madeleine

2017-01-01

Skeletal muscle has high energy requirement and alterations in metabolism are associated with pathological conditions causing muscle wasting and impaired regeneration. Congenital muscular dystrophy type 1A (MDC1A) is a severe muscle disorder caused by mutations in the LAMA2 gene. Leigh syndrome (LS) is a neurometabolic disease caused by mutations in genes related to mitochondrial function. Skeletal muscle is severely affected in both diseases and a common feature is muscle weakness that leads to hypotonia and respiratory problems. Here, we have investigated the bioenergetic profile in myogenic cells from MDC1A and LS patients. We found dysregulated expression of genes related to energy production, apoptosis and proteasome in myoblasts and myotubes. Moreover, impaired mitochondrial function and a compensatory upregulation of glycolysis were observed when monitored in real-time. Also, alterations in cell cycle populations in myoblasts and enhanced caspase-3 activity in myotubes were observed. Thus, we have for the first time demonstrated an impairment of the bioenergetic status in human MDC1A and LS muscle cells, which could contribute to cell cycle disturbance and increased apoptosis. Our findings suggest that skeletal muscle metabolism might be a promising pharmacological target in order to improve muscle function, energy efficiency and tissue maintenance of MDC1A and LS patients. PMID:28367954

Absence of γ-Chain in Keratinocytes Alters Chemokine Secretion, Resulting in Reduced Immune Cell Recruitment.

PubMed

Nowak, Karolin; Linzner, Daniela; Thrasher, Adrian J; Lambert, Paul F; Di, Wei-Li; Burns, Siobhan O

2017-10-01

Loss-of-function mutations in the common gamma (γc) chain cytokine receptor subunit give rise to severe combined immunodeficiency characterized by lack of T and natural killer cells and infant death from infection. Hematopoietic stem cell transplantation or gene therapy offer a cure, but despite successful replacement of lymphoid immune lineages, a long-term risk of severe cutaneous human papilloma virus infections persists, possibly related to persistent γc-deficiency in other cell types. Here we show that keratinocytes, the only cell type directly infected by human papilloma virus, express functional γc and its co-receptors. After stimulation with the γc-ligand IL-15, γc-deficient keratinocytes show significantly impaired secretion of specific chemokines including CXCL1, CXCL8, and CCL20, resulting in reduced chemotaxis of dendritic cells and CD4 + T cells. Furthermore, γc-deficient keratinocytes also exhibit defective induction of T-cell chemotaxis in a model of stable human papilloma virus-18 infection. These findings suggest that persistent γc-deficiency in keratinocytes alters immune cell recruitment to the skin, which may contribute to the development and persistence of warts in this condition and would require different treatment approaches. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Binding of Amphipathic Cell Penetrating Peptide p28 to Wild Type and Mutated p53 as studied by Raman, Atomic Force and Surface Plasmon Resonance spectroscopies.

PubMed

Signorelli, Sara; Santini, Simona; Yamada, Tohru; Bizzarri, Anna Rita; Beattie, Craig W; Cannistraro, Salvatore

2017-04-01

Mutations within the DNA binding domain (DBD) of the tumor suppressor p53 are found in >50% of human cancers and may significantly modify p53 secondary structure impairing its function. p28, an amphipathic cell-penetrating peptide, binds to the DBD through hydrophobic interaction and induces a posttranslational increase in wildtype and mutant p53 restoring functionality. We use mutation analyses to explore which elements of secondary structure may be critical to p28 binding. Molecular modeling, Raman spectroscopy, Atomic Force Spectroscopy (AFS) and Surface Plasmon Resonance (SPR) were used to identify which secondary structure of site-directed and naturally occurring mutant DBDs are potentially altered by discrete changes in hydrophobicity and the molecular interaction with p28. We show that specific point mutations that alter hydrophobicity within non-mutable and mutable regions of the p53 DBD alter specific secondary structures. The affinity of p28 was positively correlated with the β-sheet content of a mutant DBD, and reduced by an increase in unstructured or random coil that resulted from a loss in hydrophobicity and redistribution of surface charge. These results help refine our knowledge of how mutations within p53-DBD alter secondary structure and provide insight on how potential structural alterations in p28 or similar molecules improve their ability to restore p53 function. Raman spectroscopy, AFS, SPR and computational modeling are useful approaches to characterize how mutations within the p53DBD potentially affect secondary structure and identify those structural elements prone to influence the binding affinity of agents designed to increase the functionality of p53. Copyright © 2017 Elsevier B.V. All rights reserved.

Origins and implications of pluripotent stem cell variability and heterogeneity

PubMed Central

Cahan, Patrick; Daley, George Q.

2014-01-01

Pluripotent stem cells constitute a platform to model disease and developmental processes and can potentially be used in regenerative medicine. However, not all pluripotent cell lines are equal in their capacity to differentiate into desired cell types in vitro. Genetic and epigenetic variations contribute to functional variability between cell lines and heterogeneity within clones. These genetic and epigenetic variations could ‘lock’ the pluripotency network resulting in residual pluripotent cells or alter the signalling response of developmental pathways leading to lineage bias. The molecular contributors to functional variability and heterogeneity in both embryonic stem (ES) cells and induced pluripotent stem (iPS) cells are only beginning to emerge, yet they are crucial to the future of the stem cell field. PMID:23673969

Effects of nicotine exposure during prenatal or perinatal period on cell numbers in adult rat hippocampus and cerebellum: a stereology study.

PubMed

Chen, Wei-Jung A; King, Karen A; Lee, Ruby E; Sedtal, Christopher S; Smith, Andrew M

2006-11-02

Smoking during pregnancy poses a potential risk to unborn children. The present study examined the long-term effects of early nicotine exposure on the number of pyramidal and granule cells in the hippocampus, and Purkinje cells in the cerebellar vermis. The loss of neurons is the most severe form of brain injury with significant functional implications. In this study, rats were exposed to nicotine during either the prenatal (PRE) period or both the prenatal and early postnatal (PERI) period. It was hypothesized that nicotine treatment would result in long-term decreases in neuronal numbers, and that PERI treatment would be more detrimental to these cell populations than the PRE treatment. The results showed that neither PRE nor PERI nicotine exposure reduces the numbers of pyramidal, granule or Purkinje cells. Neither the regions where these cells reside, nor the cell densities were affected by nicotine. Although no significant cell loss was observed, the current nicotine exposure regimens may lead to alterations in cellular functions or cytoarchitectures. The present results in conjunction with previous reports showing significant cell loss from nicotine exposure during the brain growth spurt suggest that "patch-like" nicotine exposure during prenatal period may alter the sensitivity or the responsiveness of the developing brain to the injurious effects of nicotine during the most vulnerable stage of brain development - the brain growth spurt. Furthermore, the current stereology cell counting results are not in agreement with some reports in the literature, and this discrepancy may simply be a function of different cell counting techniques used.

Reversible Reprogramming of Circulating Memory T Follicular Helper Cell Function during Chronic HIV Infection

PubMed Central

Cubas, Rafael; van Grevenynghe, Julien; Wills, Saintedym; Kardava, Lela; Santich, Brian H.; Buckner, Clarisa M.; Muir, Roshell; Tardif, Virginie; Nichols, Carmen; Procopio, Francesco; He, Zhong; Metcalf, Talibah; Ghneim, Khader; Locci, Michela; Ancuta, Petronella; Routy, Jean-Pierre; Trautmann, Lydie; Li, Yuxing; McDermott, Adrian B.; Koup, Rick A.; Petrovas, Constantinos; Migueles, Steven A.; Connors, Mark; Tomaras, Georgia D.; Moir, Susan; Crotty, Shane

2015-01-01

Despite the overwhelming benefits of antiretroviral therapy (ART) in curtailing viral load in HIV-infected individuals, ART does not fully restore cellular and humoral immunity. HIV-infected individuals under ART show reduced responses to vaccination and infections and are unable to mount an effective antiviral immune response upon ART cessation. Many factors contribute to these defects, including persistent inflammation, especially in lymphoid tissues, where T follicular helper (Tfh) cells instruct and help B cells launch an effective humoral immune response. In this study we investigated the phenotype and function of circulating memory Tfh cells as a surrogate of Tfh cells in lymph nodes and found significant impairment of this cell population in chronically HIV-infected individuals, leading to reduced B cell responses. We further show that these aberrant memory Tfh cells exhibit an IL-2–responsive gene signature and are more polarized toward a Th1 phenotype. Treatment of functional memory Tfh cells with IL-2 was able to recapitulate the detrimental reprogramming. Importantly, this defect was reversible, as interfering with the IL-2 signaling pathway helped reverse the abnormal differentiation and improved Ab responses. Thus, reversible reprogramming of memory Tfh cells in HIV-infected individuals could be used to enhance Ab responses. Altered microenvironmental conditions in lymphoid tissues leading to altered Tfh cell differentiation could provide one explanation for the poor responsiveness of HIV-infected individuals to new Ags. This explanation has important implications for the development of therapeutic interventions to enhance HIV- and vaccine-mediated Ab responses in patients under ART. PMID:26546609

Age-related changes in cell localization and proliferation in lymph nodes and spleen after antigenic stimulation.

PubMed Central

Ansell, J D; McDougall, C M; Micklem, H S; Inchley, C J

1980-01-01

Antigen-dependent localization of 51Cr-labelled lymphocytes, and the subsequent uptake of IUdR into lymphoid organs has been studied as a function of age. Measures of cell localization indicated that while old age can alter the patterns of entry of lymphocytes into lymph nodes and spleen, these changes are variable and probably not sufficient alone to explain decreased primary antibody responses in old animals. Proliferation of cells, however, was consistently affected in both organs and this phenomenon is discussed in terms of abnormal T-cell function. PMID:7429546

Longitudinal Analysis of Calorie Restriction on Rat Taste Bud Morphology and Expression of Sweet Taste Modulators

PubMed Central

Cai, Huan; Daimon, Caitlin M.; Cong, Wei-na; Wang, Rui; Chirdon, Patrick; de Cabo, Rafael; Sévigny, Jean; Maudsley, Stuart; Martin, Bronwen

2014-01-01

Calorie restriction (CR) is a lifestyle intervention employed to reduce body weight and improve metabolic functions primarily via reduction of ingested carbohydrates and fats. Taste perception is highly related to functional metabolic status and body adiposity. We have previously shown that sweet taste perception diminishes with age; however, relatively little is known about the effects of various lengths of CR upon taste cell morphology and function. We investigated the effects of CR on taste bud morphology and expression of sweet taste–related modulators in 5-, 17-, and 30-month-old rats. In ad libitum (AL) and CR rats, we consistently found the following parameters altered significantly with advancing age: reduction of taste bud size and taste cell numbers per taste bud and reduced expression of sonic hedgehog, type 1 taste receptor 3 (T1r3), α-gustducin, and glucagon-like peptide-1 (GLP-1). In the oldest rats, CR affected a significant reduction of tongue T1r3, GLP-1, and α-gustducin expression compared with age-matched AL rats. Leptin receptor immunopositive cells were elevated in 17- and 30-month-old CR rats compared with age-matched AL rats. These alterations of sweet taste–related modulators, specifically during advanced aging, suggest that sweet taste perception may be altered in response to different lengths of CR. PMID:24077597

Relationship of Soluble RAGE with Insulin Resistance and Beta Cell Function during Development of Type 2 Diabetes Mellitus

PubMed Central

Biswas, Subrata Kumar; Mohtarin, Sabreena; Mudi, Sonchita Rani; Anwar, Taznuva; Banu, Laila Anjuman; Alam, Sheikh Md. Khorshed; Fariduddin, Md.; Arslan, M. Iqbal

2015-01-01

This study examined whether circulating levels of soluble receptor for advanced glycation end products (sRAGE) alter in prediabetes and correlate with insulin resistance (IR) and beta cell function in prediabetes and newly diagnosed type 2 diabetes mellitus (T2DM). Subjects without previous history of diabetes were recruited and grouped as control, prediabetes, and newly diagnosed T2DM. The control subjects (n = 40) and people with prediabetes (n = 52) and diabetes (n = 66) were similar in terms of age, sex, BMI, systolic and diastolic BP, and fasting insulin level. HOMA-IR was found significantly higher in people with diabetes than control subjects (p < 0.001) and people with prediabetes (p = 0.005); and HOMA-%B was found significantly deteriorated in people with diabetes (p < 0.001) compared to control subjects and people with prediabetes. However, serum sRAGE levels did not show any significant alteration in people with prediabetes compared to control subjects. Moreover, univariate and multivariate analyses did not identify any significant correlation and statistical association of sRAGE with HOMA-IR and HOMA-%B in people with prediabetes and newly diagnosed T2DM. Our data suggest that serum sRAGE levels do not alter in people with prediabetes compared to control subjects and do not correlate or associate with IR and beta cell function during development of T2DM. PMID:26078977

Longitudinal analysis of calorie restriction on rat taste bud morphology and expression of sweet taste modulators.

PubMed

Cai, Huan; Daimon, Caitlin M; Cong, Wei-Na; Wang, Rui; Chirdon, Patrick; de Cabo, Rafael; Sévigny, Jean; Maudsley, Stuart; Martin, Bronwen

2014-05-01

Calorie restriction (CR) is a lifestyle intervention employed to reduce body weight and improve metabolic functions primarily via reduction of ingested carbohydrates and fats. Taste perception is highly related to functional metabolic status and body adiposity. We have previously shown that sweet taste perception diminishes with age; however, relatively little is known about the effects of various lengths of CR upon taste cell morphology and function. We investigated the effects of CR on taste bud morphology and expression of sweet taste-related modulators in 5-, 17-, and 30-month-old rats. In ad libitum (AL) and CR rats, we consistently found the following parameters altered significantly with advancing age: reduction of taste bud size and taste cell numbers per taste bud and reduced expression of sonic hedgehog, type 1 taste receptor 3 (T1r3), α-gustducin, and glucagon-like peptide-1 (GLP-1). In the oldest rats, CR affected a significant reduction of tongue T1r3, GLP-1, and α-gustducin expression compared with age-matched AL rats. Leptin receptor immunopositive cells were elevated in 17- and 30-month-old CR rats compared with age-matched AL rats. These alterations of sweet taste-related modulators, specifically during advanced aging, suggest that sweet taste perception may be altered in response to different lengths of CR.

Relationship of Soluble RAGE with Insulin Resistance and Beta Cell Function during Development of Type 2 Diabetes Mellitus.

PubMed

Biswas, Subrata Kumar; Mohtarin, Sabreena; Mudi, Sonchita Rani; Anwar, Taznuva; Banu, Laila Anjuman; Alam, Sheikh Md Khorshed; Fariduddin, Md; Arslan, M Iqbal

2015-01-01

This study examined whether circulating levels of soluble receptor for advanced glycation end products (sRAGE) alter in prediabetes and correlate with insulin resistance (IR) and beta cell function in prediabetes and newly diagnosed type 2 diabetes mellitus (T2DM). Subjects without previous history of diabetes were recruited and grouped as control, prediabetes, and newly diagnosed T2DM. The control subjects (n = 40) and people with prediabetes (n = 52) and diabetes (n = 66) were similar in terms of age, sex, BMI, systolic and diastolic BP, and fasting insulin level. HOMA-IR was found significantly higher in people with diabetes than control subjects (p < 0.001) and people with prediabetes (p = 0.005); and HOMA-%B was found significantly deteriorated in people with diabetes (p < 0.001) compared to control subjects and people with prediabetes. However, serum sRAGE levels did not show any significant alteration in people with prediabetes compared to control subjects. Moreover, univariate and multivariate analyses did not identify any significant correlation and statistical association of sRAGE with HOMA-IR and HOMA-%B in people with prediabetes and newly diagnosed T2DM. Our data suggest that serum sRAGE levels do not alter in people with prediabetes compared to control subjects and do not correlate or associate with IR and beta cell function during development of T2DM.

Curcumin Modulates Pancreatic Adenocarcinoma Cell-Derived Exosomal Function

PubMed Central

Osterman, Carlos J. Diaz; Lynch, James C.; Leaf, Patrick; Gonda, Amber; Ferguson Bennit, Heather R.; Griffiths, Duncan; Wall, Nathan R.

2015-01-01

Pancreatic cancer has the highest mortality rates of all cancer types. One potential explanation for the aggressiveness of this disease is that cancer cells have been found to communicate with one another using membrane-bound vesicles known as exosomes. These exosomes carry pro-survival molecules and increase the proliferation, survival, and metastatic potential of recipient cells, suggesting that tumor-derived exosomes are powerful drivers of tumor progression. Thus, to successfully address and eradicate pancreatic cancer, it is imperative to develop therapeutic strategies that neutralize cancer cells and exosomes simultaneously. Curcumin, a turmeric root derivative, has been shown to have potent anti-cancer and anti-inflammatory effects in vitro and in vivo. Recent studies have suggested that exosomal curcumin exerts anti-inflammatory properties on recipient cells. However, curcumin’s effects on exosomal pro-tumor function have yet to be determined. We hypothesize that curcumin will alter the pro-survival role of exosomes from pancreatic cancer cells toward a pro-death role, resulting in reduced cell viability of recipient pancreatic cancer cells. The main objective of this study was to determine the functional alterations of exosomes released by pancreatic cancer cells exposed to curcumin compared to exosomes from untreated pancreatic cancer cells. We demonstrate, using an in vitro cell culture model involving pancreatic adenocarcinoma cell lines PANC-1 and MIA PaCa-2, that curcumin is incorporated into exosomes isolated from curcumin-treated pancreatic cancer cells as observed by spectral studies and fluorescence microscopy. Furthermore, curcumin is delivered to recipient pancreatic cancer cells via exosomes, promoting cytotoxicity as demonstrated by Hoffman modulation contrast microscopy as well as AlamarBlue and Trypan blue exclusion assays. Collectively, these data suggest that the efficacy of curcumin may be enhanced in pancreatic cancer cells through exosomal facilitation. PMID:26177391

Cell-to-cell communication and cellular environment alter the somatostatin status of delta cells

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

Kelly, Catriona, E-mail: catriona.kelly@qub.ac.uk; Flatt, Peter R.; McClenaghan, Neville H.

2010-08-20

Research highlights: {yields} TGP52 cells display enhanced functionality in pseudoislet form. {yields} Somatostatin content was reduced, but secretion increased in high glucose conditions. {yields} Cellular interactions and environment alter the somatostatin status of TGP52 cells. -- Abstract: Introduction: Somatostatin, released from pancreatic delta cells, is a potent paracrine inhibitor of insulin and glucagon secretion. Islet cellular interactions and glucose homeostasis are essential to maintain normal patterns of insulin secretion. However, the importance of cell-to-cell communication and cellular environment in the regulation of somatostatin release remains unclear. Methods: This study employed the somatostatin-secreting TGP52 cell line maintained in DMEM:F12 (17.5 mMmore » glucose) or DMEM (25 mM glucose) culture media. The effect of pseudoislet formation and culture medium on somatostatin content and release in response to a variety of stimuli was measured by somatostatin EIA. In addition, the effect of pseudoislet formation on cellular viability (MTT and LDH assays) and proliferation (BrdU ELISA) was determined. Results: TGP52 cells readily formed pseudoislets and showed enhanced functionality in three-dimensional form with increased E-cadherin expression irrespective of the culture environment used. However, culture in DMEM decreased cellular somatostatin content (P < 0.01) and increased somatostatin secretion in response to a variety of stimuli including arginine, calcium and PMA (P < 0.001) when compared with cells grown in DMEM:F12. Configuration of TGP52 cells as pseudoislets reduced the proliferative rate and increased cellular cytotoxicity irrespective of culture medium used. Conclusions: Somatostatin secretion is greatly facilitated by cell-to-cell interactions and E-cadherin expression. Cellular environment and extracellular glucose also significantly influence the function of delta cells.« less

Epithelial Permeability Alterations in an In Vitro Air-Liquid Interface Model of Allergic Fungal Rhinosinusitis

PubMed Central

Den Beste, Kyle A.; Hoddeson, Elizabeth K.; Parkos, Charles A.; Nusrat, Asma; Wise, Sarah K.

2012-01-01

Background Chronic rhinosinusitis (CRS) is an inflammatory upper-airway disease with numerous etiologies. Patients with a characteristic subtype of CRS, allergic fungal rhinosinusitis (AFRS), display increased expression of Th2 cytokines and antigen-specific IgE. Various sinonasal inflammatory conditions are associated with alterations in epithelial barrier function. The aim of this study was to compare epithelial permeability and intercellular junctional protein expression amongst cultured primary sinonasal cells from AFRS patients versus non-inflammatory controls. Methods Epithelial cells isolated from paranasal sinus mucosa of AFRS and non-inflammatory control patients were grown to confluence on permeable supports and transitioned to air-liquid interface (ALI). Trans-epithelial resistance (TER) was measured with a horizontal Ussing chamber to characterize the functional permeability of each cell type. After TER recordings were complete, a panel of intercellular junctional proteins was assessed by Western blot and immunofluorescence labeling followed by confocal microscopy. Results After 12 samples were measured from each group, we observed a 41% mean decrease in TER in AFRS cells (296±89 ohms × cm2) compared to control (503±134 ohms × cm2, P=0.006). TER deficits observed in AFRS were associated with decreased expression of the tight junction proteins occludin and Junctional Adhesion Molecule-A (JAM-A), and increased expression of a leaky tight junction protein claudin-2. Conclusions Cultured sinonasal epithelium from AFRS patients displayed increased epithelial permeability and altered expression of intercellular junctional proteins. Given that these cells were not incubated with inflammatory cytokines in vitro, the cultured AFRS epithelial alterations may represent a retained modification in protein expression from the in vivo phenotype. PMID:22927233

Collective cell migration during inflammatory response

NASA Astrophysics Data System (ADS)

Wu, Di; Stroka, Kimberly; Aranda-Espinoza, Helim

2012-02-01

Wound scratch healing assays of endothelial cell monolayers is a simple model to study collective cell migration as a function of biological signals. A signal of particular interest is the immune response, which after initial wounding in vivo causes the release of various inflammatory factors such as tumor necrosis alpha (TNF-α). TNF-α is an innate inflammatory cytokine that can induce cell growth, cell necrosis, and change cell morphology. We studied the effects of TNF-α on collective cell migration using the wound healing assays and measured several migration metrics, such as rate of scratch closure, velocities of leading edge and bulk cells, closure index, and velocity correlation functions between migrating cells. We observed that TNF-α alters all migratory metrics as a function of the size of the scratch and TNF-α content. The changes observed in migration correlate with actin reorganization upon TNF-α exposure.

[Influence of Cx26/Cx32 gap junction channel on antineoplastic effect of etoposide in Hela cells].

PubMed

Tong, Xu-Hui; Dong, Shu-Ying; Jiang, Guo-Jun; Fan, Gao-Fu

2012-03-01

To observe the influence of Cx26/Cx32 gap junction channel on the antineoplastic effect of etoposide in Hela cervical cancer cells. Fluorescence trace was used to assay the gap junction intercellular communication mediated by Cx26/Cx32 in Hela cells and its functional modulation by the pharmacological agents (oleamide, retinoid acid). A standard colony-forming assay was applied to determine the cell growth-inhibiting effect of etoposide in Hela cells with functional modulation of the gap junction. Hoechst 33258 staining was used to assess the changes in etoposide-induced apoptosis of Hela cells with altered gap junction functions. Oleamide markedly decreased while retinoid acid obviously increased the gap junction function in Hela cells. Standard colony-forming assay showed that etoposide produced a lowered antiproliferative effect in Hela cells with reduced gap junction and an increased antiproliferative effect in cells with enhanced gap junction function. In cells with a reduced gap junction function, etoposide induced a lowered apoptosis rate, which increased obviously in cells with an enhanced gap junction function. The antineoplastic effect of etoposide is reduced in Hela cells with a decreased gap junction intercellular communication mediated by Cx26/Cx32 and is enhanced in cells with an increased gap junction intercellular communication.

Mechanisms responsible for decreased glomerular filtration in hibernation and hypothermia

NASA Technical Reports Server (NTRS)

Tempel, G. E.; Musacchia, X. J.; Jones, S. B.

1977-01-01

Measurements of blood pressure, heart rate, red blood cell and plasma volumes, and relative distribution of cardiac output were made on hibernating and hypothermic adult male and female golden hamsters weighing 120-140 g to study the mechanisms underlying the elimination or marked depression of renal function in hibernation and hypothermia. The results suggest that the elimination or marked depression in renal function reported in hibernation and hypothermia may partly be explained by alterations in cardiovascular system function. Renal perfusion pressure which decreases nearly 60% in both hibernation and hypothermia and a decrease in plasma volume of roughly 35% in the hypothermic animal might both be expected to markedly alter glomerular function.

Unique cell culture systems for ground based research

NASA Technical Reports Server (NTRS)

Lewis, Marian L.

1990-01-01

The horizontally rotating fluid-filled, membrane oxygenated bioreactors developed at NASA Johnson for spacecraft applications provide a powerful tool for ground-based research. Three-dimensional aggregates formed by cells cultured on microcarrier beads are useful for study of cell-cell interactions and tissue development. By comparing electron micrographs of plant seedlings germinated during Shuttle flight 61-C and in an earth-based rotating bioreactor it is shown that some effects of microgravity are mimicked. Bioreactors used in the UAH Bioreactor Laboratory will make it possible to determine some of the effects of altered gravity at the cellular level. Bioreactors can be valuable for performing critical, preliminary-to-spaceflight experiments as well as medical investigations such as in vitro tumor cell growth and chemotherapeutic drug response; the enrichment of stem cells from bone marrow; and the effect of altered gravity on bone and muscle cell growth and function and immune response depression.

Parvovirus Capsid Structures Required for Infection: Mutations Controlling Receptor Recognition and Protease Cleavages

PubMed Central

Callaway, Heather M.; Feng, Kurtis H.; Lee, Donald W.; Pinard, Melissa; McKenna, Robert; Agbandje-McKenna, Mavis; Hafenstein, Susan

2016-01-01

ABSTRACT Parvovirus capsids are small but complex molecular machines responsible for undertaking many of the steps of cell infection, genome packing, and cell-to-cell as well as host-to-host transfer. The details of parvovirus infection of cells are still not fully understood, but the processes must involve small changes in the capsid structure that allow the endocytosed virus to escape from the endosome, pass through the cell cytoplasm, and deliver the single-stranded DNA (ssDNA) genome to the nucleus, where viral replication occurs. Here, we examine capsid substitutions that eliminate canine parvovirus (CPV) infectivity and identify how those mutations changed the capsid structure or altered interactions with the infectious pathway. Amino acid substitutions on the exterior surface of the capsid (Gly299Lys/Ala300Lys) altered the binding of the capsid to transferrin receptor type 1 (TfR), particularly during virus dissociation from the receptor, but still allowed efficient entry into both feline and canine cells without successful infection. These substitutions likely control specific capsid structural changes resulting from TfR binding required for infection. A second set of changes on the interior surface of the capsid reduced viral infectivity by >100-fold and included two cysteine residues and neighboring residues. One of these substitutions, Cys270Ser, modulates a VP2 cleavage event found in ∼10% of the capsid proteins that also was shown to alter capsid stability. A neighboring substitution, Pro272Lys, significantly reduced capsid assembly, while a Cys273Ser change appeared to alter capsid transport from the nucleus. These mutants reveal additional structural details that explain cell infection processes of parvovirus capsids. IMPORTANCE Parvoviruses are commonly found in both vertebrate and invertebrate animals and cause widespread disease. They are also being developed as oncolytic therapeutics and as gene therapy vectors. Most functions involved in infection or transduction are mediated by the viral capsid, but the structure-function correlates of the capsids and their constituent proteins are still incompletely understood, especially in relation to identifying capsid processes responsible for infection and release from the cell. Here, we characterize the functional effects of capsid protein mutations that result in the loss of virus infectivity, giving a better understanding of the portions of the capsid that mediate essential steps in successful infection pathways and how they contribute to viral infectivity. PMID:27847360

Parvovirus Capsid Structures Required for Infection: Mutations Controlling Receptor Recognition and Protease Cleavages.

PubMed

Callaway, Heather M; Feng, Kurtis H; Lee, Donald W; Allison, Andrew B; Pinard, Melissa; McKenna, Robert; Agbandje-McKenna, Mavis; Hafenstein, Susan; Parrish, Colin R

2017-01-15

Parvovirus capsids are small but complex molecular machines responsible for undertaking many of the steps of cell infection, genome packing, and cell-to-cell as well as host-to-host transfer. The details of parvovirus infection of cells are still not fully understood, but the processes must involve small changes in the capsid structure that allow the endocytosed virus to escape from the endosome, pass through the cell cytoplasm, and deliver the single-stranded DNA (ssDNA) genome to the nucleus, where viral replication occurs. Here, we examine capsid substitutions that eliminate canine parvovirus (CPV) infectivity and identify how those mutations changed the capsid structure or altered interactions with the infectious pathway. Amino acid substitutions on the exterior surface of the capsid (Gly299Lys/Ala300Lys) altered the binding of the capsid to transferrin receptor type 1 (TfR), particularly during virus dissociation from the receptor, but still allowed efficient entry into both feline and canine cells without successful infection. These substitutions likely control specific capsid structural changes resulting from TfR binding required for infection. A second set of changes on the interior surface of the capsid reduced viral infectivity by >100-fold and included two cysteine residues and neighboring residues. One of these substitutions, Cys270Ser, modulates a VP2 cleavage event found in ∼10% of the capsid proteins that also was shown to alter capsid stability. A neighboring substitution, Pro272Lys, significantly reduced capsid assembly, while a Cys273Ser change appeared to alter capsid transport from the nucleus. These mutants reveal additional structural details that explain cell infection processes of parvovirus capsids. Parvoviruses are commonly found in both vertebrate and invertebrate animals and cause widespread disease. They are also being developed as oncolytic therapeutics and as gene therapy vectors. Most functions involved in infection or transduction are mediated by the viral capsid, but the structure-function correlates of the capsids and their constituent proteins are still incompletely understood, especially in relation to identifying capsid processes responsible for infection and release from the cell. Here, we characterize the functional effects of capsid protein mutations that result in the loss of virus infectivity, giving a better understanding of the portions of the capsid that mediate essential steps in successful infection pathways and how they contribute to viral infectivity. Copyright © 2017 American Society for Microbiology.

Legumain Regulates Differentiation Fate of Human Bone Marrow Stromal Cells and Is Altered in Postmenopausal Osteoporosis.

PubMed

Jafari, Abbas; Qanie, Diyako; Andersen, Thomas L; Zhang, Yuxi; Chen, Li; Postert, Benno; Parsons, Stuart; Ditzel, Nicholas; Khosla, Sundeep; Johansen, Harald Thidemann; Kjærsgaard-Andersen, Per; Delaisse, Jean-Marie; Abdallah, Basem M; Hesselson, Daniel; Solberg, Rigmor; Kassem, Moustapha

2017-02-14

Secreted factors are a key component of stem cell niche and their dysregulation compromises stem cell function. Legumain is a secreted cysteine protease involved in diverse biological processes. Here, we demonstrate that legumain regulates lineage commitment of human bone marrow stromal cells and that its expression level and cellular localization are altered in postmenopausal osteoporotic patients. As shown by genetic and pharmacological manipulation, legumain inhibited osteoblast (OB) differentiation and in vivo bone formation through degradation of the bone matrix protein fibronectin. In addition, genetic ablation or pharmacological inhibition of legumain activity led to precocious OB differentiation and increased vertebral mineralization in zebrafish. Finally, we show that localized increased expression of legumain in bone marrow adipocytes was inversely correlated with adjacent trabecular bone mass in a cohort of patients with postmenopausal osteoporosis. Our data suggest that altered proteolytic activity of legumain in the bone microenvironment contributes to decreased bone mass in postmenopausal osteoporosis. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

RED BLOOD CELL STORAGE LESION

PubMed Central

Kor, Daryl J.; Van Buskirk, Camille M; Gajic, Ognjen

2009-01-01

The past two decades have witnessed increased scrutiny regarding efficacy and risk of the once unquestioned therapy of red blood cell (RBC) transfusion. Simultaneously, a variety of changes have been identified within the RBC and storage media during RBC preservation that are correlated with reduced tissue oxygenation and transfusion-associated adverse effects. These alterations are collectively termed the storage lesion and include extensive biochemical, biomechanical, and immunologic changes involving cells of diverse origin. Time-dependent falls is 2,3-diphosphoglycerate, intracellular RBC adenosine triphosphate, and nitric oxide have been shown to impact RBC deformability and delivery of oxygen to the end-organ. The accumulation of biologic response modifiers such as soluble CD40 ligand (sCD40L), lyso-phosphatidylcholine (lyso-PC), and Regulated on Activation, Normal T-cell Expressed and Secreted (RANTES) have been associated with altered recipient immune function as well. This review will address the alterations occurring within the RBC and storage media during RBC preservation and will address the potential clinical consequence thereof.

Influence of thyroid in nervous system growth.

PubMed

Mussa, G C; Mussa, F; Bretto, R; Zambelli, M C; Silvestro, L

2001-08-01

Nervous system growth and differentiation are closely correlated with the presence of iodine and thyroid hormones in initial development stages. In the human species, encephalon maturation during the first quarter of pregnancy is affected according to recent studies by the transplacenta passage of maternal thyroid hormones while it depends on initial iodiothyronin secretion by the foetal gland after the 12th week of pregnancy. Thyroid hormone deficiency during nervous system development causes altered noble nervous cells, such as the pyramidal cortical and Purkinje cells, during glial cell proliferation and differentiation alike. Neurons present cell hypoplasia with reduced axon count, dendritic branching, synaptic spikes and interneuron connections. Oligodendrocytes decrease in number and average myelin content consequently drops. Biochemical studies on hypothyroid rats have demonstrated alterations to neuron intraplasmatic microtubule content and organisation, changed mitochondria number and arrangement and anomalies in T3 nuclear and citoplasmatic receptor maturation. Alterations to microtubules are probably responsible for involvement of the axon-dendrite system, and are the consequence of deficient thyroid hormone action on the mitochondria, the mitochondria enzymes and proteins associated with microtubules. Nuclear and citoplasmatic receptors have been identified and gene clonation studies have shown two families of nuclear receptors that include several sub-groups in their turn. A complex scheme of temporal and spatial expression of these receptors exists, so they probably contribute with one complementary function, although their physiological role differs. The action of thyroid hormones occurs by changing cell protein levels because of their regulation at the transcriptional or post-transcriptional level. Genes submitted to thyroid hormone control are either expressed by oligodendrytes, which are myelin protein coders or glial differentiation mediators, or are nervous cell specific, genes coding neurotropins or proteins involved in synaptic excitation. The use of new PMRS and MRI non-invasive techniques has enabled identification of metabolic and biochemical markers for alterations in the encephalon of untreated hypothyroid children. Even an excess of thyroid hormones during early nervous system development can cause permanent effects. Hyperthyroidism in fact initially induces accelerated maturation process including cell migration and differentiation, extension of dendritic processes and synaptogenesis but a later excess of thyroid hormones causes reduction of the total number of dendritic spikes, due to early interruption of neuron proliferation. Experimental studies and clinical research have clarified not only the correlation between nervous system maturation and thyroid function during early development stages and the certain finding from this research is that both excess and deficient thyroid hormones can cause permanent anatomo-functional alterations to the nervous system.

Role of Hypomethylating Agents in the Treatment of Bone Marrow Failure

DTIC Science & Technology

2016-10-01

functional studies, as proposed in Aim 2, to find that cells with cohesin gene mutations are sensitized to hypomethylating agents. We used CRISPR /Cas9...screen loss of function mutations in MDS for response to azacitidine. We used CRISPR /Cas9 genome engineering of primary human hematopoietic stem and...investigate whether sites of altered methylation occur at hydroxymethylated loci. We generated isogenic TF-1 cell line clones using CRISPR -Cas9

Tumor-derived exosomes modulate T cell function through transfer of RNA.

PubMed

House, Imran G; Petley, Emma V; Beavis, Paul A

2018-03-01

Tumor cells can develop a variety of mechanisms to evade and subvert the immune system for their survival. Bland et al., in this edition of The FEBS Journal, make the novel finding that the tumor line B16F0 can deliver mRNA/miRNA loaded exosomes to cytotoxic T lymphocytes and alter their metabolic function and interferon gamma production. © 2018 Federation of European Biochemical Societies.

Preserved MHC-II antigen processing and presentation function in chronic HCV infection

PubMed Central

DH, Canaday; CJ, Burant; L, Jones; H, Aung; L, Woc-Colburn; DD, Anthony

2010-01-01

Individuals with chronic HCV infection have impaired response to vaccine, though the etiology remains to be elucidated. Dendritic cells (DC) and monocytes (MN) provide antigen uptake, processing, presentation, and costimulatory functions necessary to achieve optimal immune responses. The integrity of antigen processing and presentation function within these antigen presenting cells (APC) in the setting of HCV infection has been unclear. We used a novel T cell hybridoma system that specifically measures MHC-II antigen processing and presentation function of human APC. Results demonstrate MHC-II antigen processing and presentation function is preserved in both myeloid DC (mDC) and MN in the peripheral blood of chronically HCV-infected individuals, and indicates that an alteration in this function does not likely underlie the defective HCV-infected host response to vaccination. PMID:21055734

Calcium signaling in plant cells in microgravity

NASA Astrophysics Data System (ADS)

Kordyum, E.

Changes in the intracellular Ca 2 + concentration in altered gravity (microgravity and clinostating) evidence that Ca2 + signaling can play a fundamental role in biological effects of microgravity. Calcium as a second messenger is known to play a crucial role in stimulus - response coupling for many plant cellular signaling pathways. Its messenger functions are realized by transient changes in the cytosolic ion concentration induced by a variety of internal and external stimuli such as light, hormones, temperature, anoxia, salinity, and gravity. Although the first data on the changes in the calcium balance in plant cells under the influence of altered gravity have appeared in eighties, a review highlighting the performed research and the possible significance of such Ca 2 + changes in the structural and metabolic rearrangements of plant cells in altered gravity is still lacking. In this paper, an attempt was made to summarize the available experimental results and to consider some hypotheses in this field of research. It is proposed to distinguish between cell gravisensing and cell graviperception; the former is related to cell structure and metabolism stability in the gravitational field and their changes in microgravity (cells not specialized to gravity perception), the latter is related to active use of a gravitational stimulus by cells presumably specialized to gravity perception for realization of normal space orientation, growth, and vital activity (gravitropism, gravitaxis) in plants. The main experimental data concerning both redistribution of free Ca 2 + ions in plant cell organelles and the cell wall, and an increase in the intracellular Ca 2+ concentration under the influence of altered gravity are presented. Based on the gravitational decompensation hypothesis, the consequence of events occurring in gravis ensing cells not specialized to gravity perception under altered gravity are considered in the following order: changes in the cytoplasmic membrane surface tensionalterations in the physicochemical properties of the membranechanges in membrane permeability, ion transport, membrane-bound enzyme activity, etc.metabolism rearrangementsphysiological responses. An analysis of data available on biological effects of altered gravity at the cellular level allows one to conclude that microgravity environment appears to affect, in the first place, cytoskeleton, carbohydrate and lipid metabolism, cell wall biogenesis via changes in enzyme activity and protein expression, with involvement of regulatory Ca 2 + messenger system. Changes in Ca 2 + influx/efflux and possible pathways of Ca 2 + signaling in plant cell biochemical regulation in altered gravity are discussed.

Altered Mucin and Glycoprotein Expression in Dry Eye Disease.

PubMed

Stephens, Denise N; McNamara, Nancy A

2015-09-01

Mucins are among the many important constituents of a healthy tear film. Mucins secreted and/or associated with conjunctival goblet cells, ocular mucosal epithelial cells, and the lacrimal gland must work together to create a stable tear film. Although many studies have explored the mechanism(s) whereby mucins maintain and protect the ocular surface, the effects of dry eye on the structure and function of ocular mucins are unclear. Here, we summarize current findings regarding ocular mucins and how they are altered in dry eye. We performed a literature review of studies exploring the expression of mucins produced and/or associated with tissues that comprise the lacrimal functional unit and how they are altered in dry eye. We also summarize new insights on the immune-mediated effects of aqueous tear deficiency on ocular surface mucins that we discovered using a mouse model of dry eye. Although consistent decreases in MUC5AC and altered expression of membrane-bound mucins have been noted in both Sjögren and non-Sjögren dry eye, many reports of altered mucins in dry eye are contradictory. Mechanistic studies, including our own, suggest that changes in the glycosylation of mucins rather than the proteins themselves may occur as the direct result of local inflammation induced by proinflammatory mediators, such as interleukin-1. Altered expression of ocular mucins in dry eye varies considerably from study to study, likely attributed to inherent difficulties in analyzing small-volume tear samples, as well as differences in tear collection methods and disease severity in dry eye cohorts. To better define the functional role of ocular mucin glycosylation in the pathogenesis of dry eye disease, we propose genomic and proteomic studies along with biological pathway analysis to reveal novel avenues for exploration.

Alterations in the small intestinal wall and motor function after repeated cisplatin in rat.

PubMed

Uranga, J A; García-Martínez, J M; García-Jiménez, C; Vera, G; Martín-Fontelles, M I; Abalo, R

2017-07-01

Gastrointestinal adverse effects occurring during cancer chemotherapy are well known and feared; those persisting once treatment has finished are relatively unknown. We characterized the alterations occurring in the rat small intestine, after repeated treatment with cisplatin. Male Wistar rats received saline or cisplatin (2 mg kg -1  week -1 , for 5 weeks, ip). Gastric motor function was studied non-invasively throughout treatment (W1-W5) and 1 week after treatment finalization (W6). During W6, upper gastrointestinal motility was also invasively studied and small intestinal samples were collected for histopathological and molecular studies. Structural alterations in the small intestinal wall, mucosa, submucosa, muscle layers, and lymphocytic nodules were histologically studied. Periodic acid-Schiff staining and immunohistochemistry for Ki-67, chromogranin A, and neuronal-specific enolase were used to detect secretory, proliferating, endocrine and neural cells, respectively. The expression of different markers in the tunica muscularis was analyzed by RT/qPCR. Repeated cisplatin induced motility alterations during and after treatment. After treatment (W6), the small intestinal wall showed histopathological alterations in most parameters measured, including a reduction in the thickness of circular and longitudinal muscle layers. Expression of c-KIT (for interstitial cells of Cajal), nNOS (for inhibitory motor neurons), pChAT, and cChAT (for excitatory motor neurons) increased significantly (although both ChATs to a lesser extent). Repeated cisplatin induces relatively long-lasting gut dysmotility in rat associated with important histopathological and molecular alterations in the small intestinal wall. In cancer survivors, the possible chemotherapy-induced histopathological, molecular, and functional intestinal sequelae should be evaluated. © 2017 John Wiley & Sons Ltd.

Mutational Analysis of the Glycosylphosphatidylinositol (GPI) Anchor Pathway Demonstrates that GPI-Anchored Proteins Are Required for Cell Wall Biogenesis and Normal Hyphal Growth in Neurospora crassa

PubMed Central

Bowman, Shaun M.; Piwowar, Amy; Al Dabbous, Mash'el; Vierula, John; Free, Stephen J.

2006-01-01

Using mutational and proteomic approaches, we have demonstrated the importance of the glycosylphosphatidylinositol (GPI) anchor pathway for cell wall synthesis and integrity and for the overall morphology of the filamentous fungus Neurospora crassa. Mutants affected in the gpig-1, gpip-1, gpip-2, gpip-3, and gpit-1 genes, which encode components of the N. crassa GPI anchor biosynthetic pathway, have been characterized. GPI anchor mutants exhibit colonial morphologies, significantly reduced rates of growth, altered hyphal growth patterns, considerable cellular lysis, and an abnormal “cell-within-a-cell” phenotype. The mutants are deficient in the production of GPI-anchored proteins, verifying the requirement of each altered gene for the process of GPI-anchoring. The mutant cell walls are abnormally weak, contain reduced amounts of protein, and have an altered carbohydrate composition. The mutant cell walls lack a number of GPI-anchored proteins, putatively involved in cell wall biogenesis and remodeling. From these studies, we conclude that the GPI anchor pathway is critical for proper cell wall structure and function in N. crassa. PMID:16524913

Recent advances in understanding nuclear size and shape

PubMed Central

Mukherjee, Richik N.; Chen, Pan; Levy, Daniel L.

2016-01-01

ABSTRACT Size and shape are important aspects of nuclear structure. While normal cells maintain nuclear size within a defined range, altered nuclear size and shape are associated with a variety of diseases. It is unknown if altered nuclear morphology contributes to pathology, and answering this question requires a better understanding of the mechanisms that control nuclear size and shape. In this review, we discuss recent advances in our understanding of the mechanisms that regulate nuclear morphology, focusing on nucleocytoplasmic transport, nuclear lamins, the endoplasmic reticulum, the cell cycle, and potential links between nuclear size and size regulation of other organelles. We then discuss the functional significance of nuclear morphology in the context of early embryonic development. Looking toward the future, we review new experimental approaches that promise to provide new insights into mechanisms of nuclear size control, in particular microfluidic-based technologies, and discuss how altered nuclear morphology might impact chromatin organization and physiology of diseased cells. PMID:26963026

Doxycycline Impairs Mitochondrial Function and Protects Human Glioma Cells from Hypoxia-Induced Cell Death: Implications of Using Tet-Inducible Systems.

PubMed

Luger, Anna-Luisa; Sauer, Benedikt; Lorenz, Nadja I; Engel, Anna L; Braun, Yannick; Voss, Martin; Harter, Patrick N; Steinbach, Joachim P; Ronellenfitsch, Michael W

2018-05-17

Inducible gene expression is an important tool in molecular biology research to study protein function. Most frequently, the antibiotic doxycycline is used for regulation of so-called tetracycline (Tet)-inducible systems. In contrast to stable gene overexpression, these systems allow investigation of acute and reversible effects of cellular protein induction. Recent reports have already called for caution when using Tet-inducible systems as the employed antibiotics can disturb mitochondrial function and alter cellular metabolism by interfering with mitochondrial translation. Reprogramming of energy metabolism has lately been recognized as an important emerging hallmark of cancer and is a central focus of cancer research. Therefore, the scope of this study was to systematically analyze dose-dependent metabolic effects of doxycycline on a panel of glioma cell lines with concomitant monitoring of gene expression from Tet-inducible systems. We report that doxycycline doses commonly used with inducible expression systems (0.01⁻1 µg/mL) substantially alter cellular metabolism: Mitochondrial protein synthesis was inhibited accompanied by reduced oxygen and increased glucose consumption. Furthermore, doxycycline protected human glioma cells from hypoxia-induced cell death. An impairment of cell growth was only detectable with higher doxycycline doses (10 µg/mL). Our findings describe settings where doxycycline exerts effects on eukaryotic cellular metabolism, limiting the employment of Tet-inducible systems.

Diabetes impairs adipose tissue-derived stem cell function and efficiency in promoting wound healing.

PubMed

Cianfarani, Francesca; Toietta, Gabriele; Di Rocco, Giuliana; Cesareo, Eleonora; Zambruno, Giovanna; Odorisio, Teresa

2013-01-01

Adipose tissue-derived stem cells (ASCs) are gaining increasing consideration in tissue repair therapeutic application. Recent evidence indicates that ASCs enhance skin repair in animal models of impaired wound healing. To assess the therapeutic activity of autologous vs. allogeneic ASCs in the treatment of diabetic ulcers, we functionally characterized diabetic ASCs and investigated their potential to promote wound healing with respect to nondiabetic ones. Adipose tissue-derived cells from streptozotocin-induced type 1 diabetic mice were analyzed either freshly isolated as stromal vascular fraction (SVF), or following a single passage of culture (ASCs). Diabetic ASCs showed decreased proliferative potential and migration. Expression of surface markers was altered in diabetic SVF and cultured ASCs, with a reduction in stem cell marker-positive cells. ASCs from diabetic mice released lower amounts of hepatocyte growth factor, vascular endothelial growth factor (VEGF)-A, and insulin-like growth factor-1, growth factors playing important roles in skin repair. Accordingly, the supernatant of diabetic ASCs manifested reduced capability to promote keratinocyte and fibroblast proliferation and migration. Therapeutic potential of diabetic SVF administered to wounds of diabetic mice was blunted as compared with cells isolated from nondiabetic mice. Our data indicate that diabetes alters ASC intrinsic properties and impairs their function, thus affecting therapeutic potential in the autologous treatment for diabetic ulcers. © 2013 by the Wound Healing Society.

Biological effects of radiation, metabolic and replication kinetics alterations

NASA Technical Reports Server (NTRS)

Post, J.

1972-01-01

The biological effects of radiation upon normal and cancerous tissues were studied. A macromolecular precursor of DNA, 3ETdR, was incorporated into the cell nucleus during synthesis and provided intranuclear beta radiation. Tritium labeled cells were studied with autoradiographic methods; cell cycle kinetics were determined and cell functions modified by radiation dosage or by drugs were also evaluated. The long term program has included; (1) effects of radiation on cell replication and the correlation with incorporated dose levels, (2) radiation induced changes in cell function, viz., the response of beta irradiated spleen lymphocytes to antigenic stimulation by sheep red blood cells (SRBC), (3) kinetics of tumor and normal cell replication; and (4) megakaryocyte formation and modification by radiomimetic drugs.

The barrier function of organotypic non-melanoma skin cancer models.

PubMed

Zoschke, Christian; Ulrich, Martina; Sochorová, Michaela; Wolff, Christopher; Vávrová, Kateřina; Ma, Nan; Ulrich, Claas; Brandner, Johanna M; Schäfer-Korting, Monika

2016-07-10

Non-melanoma skin cancer (NMSC) is the most frequent human cancer with continuously rising incidences worldwide. Herein, we investigated the molecular basis for the impaired skin barrier function of organotypic NMSC models. We unraveled disturbed epidermal differentiation by reflectance confocal microscopy and histopathological evaluation. While the presence of claudin-4 and occludin were distinctly reduced, zonula occludens protein-1 was more wide-spread, and claudin-1 was heterogeneously distributed within the NMSC models compared with normal reconstructed human skin. Moreover, the cancer altered stratum corneum lipid packing and profile with decreased cholesterol content, increased phospholipid amount, and altered ceramide subclasses. These alterations contributed to increased surface pH and to 1.5 to 2.6-fold enhanced caffeine permeability of the NMSC models. Three topical applications of ingenol mebutate gel (0.015%) caused abundant epidermal cell necrosis, decreased Ki-67 indices, and increased lactate dehydrogenase activity. Taken together, our study provides new biological insights into the microenvironment of organotypic NMSC models, improves the understanding of the disease model by revealing causes for impaired skin barrier function in NMSC models at the molecular level, and fosters human cell-based approaches in preclinical drug evaluation. Copyright © 2016 Elsevier B.V. All rights reserved.

Erythro-megakaryocytic transcription factors associated with hereditary anemia

PubMed Central

Weiss, Mitchell J.

2014-01-01

Most heritable anemias are caused by mutations in genes encoding globins, red blood cell (RBC) membrane proteins, or enzymes in the glycolytic and hexose monophosphate shunt pathways. A less common class of genetic anemia is caused by mutations that alter the functions of erythroid transcription factors (TFs). Many TF mutations associated with heritable anemia cause truncations or amino acid substitutions, resulting in the production of functionally altered proteins. Characterization of these mutant proteins has provided insights into mechanisms of gene expression, hematopoietic development, and human disease. Mutations within promoter or enhancer regions that disrupt TF binding to essential erythroid genes also cause anemia and heritable variations in RBC traits, such as fetal hemoglobin content. Defining the latter may have important clinical implications for de-repressing fetal hemoglobin synthesis to treat sickle cell anemia and β thalassemia. Functionally important alterations in genes encoding TFs or their cognate cis elements are likely to occur more frequently than currently appreciated, a hypothesis that will soon be tested through ongoing genome-wide association studies and the rapidly expanding use of global genome sequencing for human diagnostics. Findings obtained through such studies of RBCs and associated diseases are likely generalizable to many human diseases and quantitative traits. PMID:24652993

Pathogenic Parkinson's disease mutations across the functional domains of LRRK2 alter the autophagic/lysosomal response to starvation.

PubMed

Manzoni, Claudia; Mamais, Adamantios; Dihanich, Sybille; McGoldrick, Phillip; Devine, Michael J; Zerle, Julia; Kara, Eleanna; Taanman, Jan-Willem; Healy, Daniel G; Marti-Masso, Jose-Felix; Schapira, Anthony H; Plun-Favreau, Helene; Tooze, Sharon; Hardy, John; Bandopadhyay, Rina; Lewis, Patrick A

2013-11-29

LRRK2 is one of the most important genetic contributors to Parkinson's disease (PD). Point mutations in this gene cause an autosomal dominant form of PD, but to date no cellular phenotype has been consistently linked with mutations in each of the functional domains (ROC, COR and Kinase) of the protein product of this gene. In this study, primary fibroblasts from individuals carrying pathogenic mutations in the three central domains of LRRK2 were assessed for alterations in the autophagy/lysosomal pathway using a combination of biochemical and cellular approaches. Mutations in all three domains resulted in alterations in markers for autophagy/lysosomal function compared to wild type cells. These data highlight the autophagy and lysosomal pathways as read outs for pathogenic LRRK2 function and as a marker for disease, and provide insight into the mechanisms linking LRRK2 function and mutations. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Boldine Prevents Renal Alterations in Diabetic Rats

PubMed Central

Hernández-Salinas, Romina; Vielma, Alejandra Z.; Arismendi, Marlene N.; Boric, Mauricio P.; Sáez, Juan C.; Velarde, Victoria

2013-01-01

Diabetic nephropathy alters both structure and function of the kidney. These alterations are associated with increased levels of reactive oxygen species, matrix proteins, and proinflammatory molecules. Inflammation decreases gap junctional communication and increases hemichannel activity leading to increased membrane permeability and altering tissue homeostasis. Since current treatments for diabetic nephropathy do not prevent renal damage, we postulated an alternative treatment with boldine, an alkaloid obtained from boldo with antioxidant, anti-inflammatory, and hypoglycemic effects. Streptozotocin-induced diabetic and control rats were treated or not treated with boldine (50 mg/Kg/day) for ten weeks. In addition, mesangial cells were cultured under control conditions or in high glucose concentration plus proinflammatory cytokines, with or without boldine (100 µmol/L). Boldine treatment in diabetic animals prevented the increase in glycemia, blood pressure, renal thiobarbituric acid reactive substances and the urinary protein/creatinine ratio. Boldine also reduced alterations in matrix proteins and markers of renal damage. In mesangial cells, boldine prevented the increase in oxidative stress, the decrease in gap junctional communication, and the increase in cell permeability due to connexin hemichannel activity induced by high glucose and proinflammatory cytokines but did not block gap junction channels. Thus boldine prevented both renal and cellular alterations and could be useful for preventing tissue damage in diabetic subjects. PMID:24416726

Boldine prevents renal alterations in diabetic rats.

PubMed

Hernández-Salinas, Romina; Vielma, Alejandra Z; Arismendi, Marlene N; Boric, Mauricio P; Sáez, Juan C; Velarde, Victoria

2013-01-01

Diabetic nephropathy alters both structure and function of the kidney. These alterations are associated with increased levels of reactive oxygen species, matrix proteins, and proinflammatory molecules. Inflammation decreases gap junctional communication and increases hemichannel activity leading to increased membrane permeability and altering tissue homeostasis. Since current treatments for diabetic nephropathy do not prevent renal damage, we postulated an alternative treatment with boldine, an alkaloid obtained from boldo with antioxidant, anti-inflammatory, and hypoglycemic effects. Streptozotocin-induced diabetic and control rats were treated or not treated with boldine (50 mg/Kg/day) for ten weeks. In addition, mesangial cells were cultured under control conditions or in high glucose concentration plus proinflammatory cytokines, with or without boldine (100 µmol/L). Boldine treatment in diabetic animals prevented the increase in glycemia, blood pressure, renal thiobarbituric acid reactive substances and the urinary protein/creatinine ratio. Boldine also reduced alterations in matrix proteins and markers of renal damage. In mesangial cells, boldine prevented the increase in oxidative stress, the decrease in gap junctional communication, and the increase in cell permeability due to connexin hemichannel activity induced by high glucose and proinflammatory cytokines but did not block gap junction channels. Thus boldine prevented both renal and cellular alterations and could be useful for preventing tissue damage in diabetic subjects.

GABA Neurons and the Mechanisms of Network Oscillations: Implications for Understanding Cortical Dysfunction in Schizophrenia

PubMed Central

Gonzalez-Burgos, Guillermo; Lewis, David A.

2008-01-01

Synchronization of neuronal activity in the neocortex may underlie the coordination of neural representations and thus is critical for optimal cognitive function. Because cognitive deficits are the major determinant of functional outcome in schizophrenia, identifying their neural basis is important for the development of new therapeutic interventions. Here we review the data suggesting that phasic synaptic inhibition mediated by specific subtypes of cortical γ-aminobutyric acid (GABA) neurons is essential for the production of synchronized network oscillations. We also discuss evidence indicating that GABA neurotransmission is altered in schizophrenia and propose mechanisms by which such alterations can decrease the strength of inhibitory connections in a cell-type–specific manner. We suggest that some alterations observed in the neocortex of schizophrenia subjects may be compensatory responses that partially restore inhibitory synaptic efficacy. The findings of altered neural synchrony and impaired cognitive function in schizophrenia suggest that such compensatory responses are insufficient and that interventions aimed at augmenting the efficacy of GABA neurotransmission might be of therapeutic value. PMID:18586694

GABA neurons and the mechanisms of network oscillations: implications for understanding cortical dysfunction in schizophrenia.

PubMed

Gonzalez-Burgos, Guillermo; Lewis, David A

2008-09-01

Synchronization of neuronal activity in the neocortex may underlie the coordination of neural representations and thus is critical for optimal cognitive function. Because cognitive deficits are the major determinant of functional outcome in schizophrenia, identifying their neural basis is important for the development of new therapeutic interventions. Here we review the data suggesting that phasic synaptic inhibition mediated by specific subtypes of cortical gamma-aminobutyric acid (GABA) neurons is essential for the production of synchronized network oscillations. We also discuss evidence indicating that GABA neurotransmission is altered in schizophrenia and propose mechanisms by which such alterations can decrease the strength of inhibitory connections in a cell-type-specific manner. We suggest that some alterations observed in the neocortex of schizophrenia subjects may be compensatory responses that partially restore inhibitory synaptic efficacy. The findings of altered neural synchrony and impaired cognitive function in schizophrenia suggest that such compensatory responses are insufficient and that interventions aimed at augmenting the efficacy of GABA neurotransmission might be of therapeutic value.

Cellular Functions of the Autism Risk Factor PTCHD1 in Mice.

PubMed

Tora, David; Gomez, Andrea M; Michaud, Jean-Francois; Yam, Patricia T; Charron, Frédéric; Scheiffele, Peter

2017-12-06

The gene patched domain containing 1 ( PTCHD1 ) is mutated in patients with autism spectrum disorders and intellectual disabilities and has been hypothesized to contribute to Sonic hedgehog (Shh) signaling and synapse formation. We identify a panel of Ptchd1-interacting proteins that include postsynaptic density proteins and the retromer complex, revealing a link to critical regulators of dendritic and postsynaptic trafficking. Ptchd1 knock-out (KO) male mice exhibit cognitive alterations, including defects in a novel object recognition task. To test whether Ptchd1 is required for Shh-dependent signaling, we examined two Shh-dependent cell populations that express high levels of Ptchd1 mRNA: cerebellar granule cell precursors and dentate granule cells in the hippocampus. We found that proliferation of these neuronal precursors was not altered significantly in Ptchd1 KO male mice. We used whole-cell electrophysiology and anatomical methods to assess synaptic function in Ptchd1-deficient dentate granule cells. In the absence of Ptchd1, we observed profound disruption in excitatory/inhibitory balance despite normal dendritic spine density on dentate granule cells. These findings support a critical role of the Ptchd1 protein in the dentate gyrus, but indicate that it is not required for structural synapse formation in dentate granule cells or for Shh-dependent neuronal precursor proliferation. SIGNIFICANCE STATEMENT The mechanisms underlying neuronal and cellular alterations resulting from patched domain containing 1 ( Ptchd1 ) gene mutations are unknown. The results from this study support an association with dendritic trafficking complexes of Ptchd1. Loss-of-function experiments do not support a role in sonic hedgehog-dependent signaling, but reveal a disruption of synaptic transmission in the mouse dentate gyrus. The findings will help to guide ongoing efforts to understand the etiology of neurodevelopmental disorders arising from Ptchd1 deficiency. Copyright © 2017 the authors 0270-6474/17/3711993-13$15.00/0.

Cell Selective Apoptosis Induced by Polymorphic Alteration of Self-Assembled Silica Nanowebs.

PubMed

Keshavarz, Meysam; Tan, Bo; Venkatakrishnan, Krishnan

2017-02-22

The biocompatibility of silicon-based nanomaterials makes them suitable for biophysical and biomedical applications. However, the application of silicon-based nanomaterials has been mainly restricted to nanoparticles (NPs) as a potential drug carrier and the extracellular matrix (ECM) as a platform for cell adhesion and proliferation. Here, we introduce silica NPs self-assembled into a 3D nanoweb architecture that was shown to inherit the therapeutic and proliferative attributes of both NPs and ECMs. The self-assembled silica nanoweb (SNW) has, therefore, not only shown targeted druglike behavior in HeLa cells without the use of biomarkers but has also shown ECM characteristics. The ECM characteristics of SNWs enhanced the cellular attraction and proliferation by which fibroblasts exhibited tissuelike behavior, and HeLa cells underwent an intensified induction of apoptosis. These properties are tailored by the alteration of the polymorphic heterogeneities of the SNW as a novel nanobiointerface for exceptional apoptosis induction through the enhancement of cellular attraction, which, to the best of our knowledge, has not been previously reported. These attributes enable selective functionality with which cancerous HeLa and mammalian fibroblast cells were affected differently. Moreover, simultaneous control of the packing index and crystallinity of the SNWs, to which the cells had been attracted, possessed the additional advantage of modulating the selective functionality of this nanobiointerface. These polymorphic characteristics were tailored by the alteration of the crystallinity of the synthesized SNW via precision control of the ionization level of the silicon substrate, whose requisite ionization energy was generated by an ultrashort pulsed laser. Our results showed that the therapeutic functionality of the SNW-plated template can be elucidated via the endocytosis of amorphous SNWs. Because of the efficient cellular attraction and remarkable contrast in the cellular response to the SNW-plated template, we expect that these findings will provide new insights and opportunities for designing and engineering novel cell-material interfaces for advanced biomedical applications in cancer research.

Changes in Monocyte Functions of Astronauts

NASA Technical Reports Server (NTRS)

Kaur, I.; Simons, E.; Castro, V.; Ott, C. Mark; Pierson, Duane L.

2004-01-01

Monocyte cell numbers and functions, including phagocytosis, oxidative burst capacity, and degranulation and expression of related surface molecules, were studied in blood specimens from 25 astronauts and 9 healthy control subjects. Blood samples were obtained 10 days before a space flight, 3 hours after landing and 3 days after landing. The number of monocytes in astronauts did not change significantly among the three sample collection periods. Following space flight, the monocytes ability to phagocytize Escherichia coli, to exhibit an oxidative burst, and to degranulate was reduced as compared to monocytes from control subjects. These alterations in monocyte functions after space flight correlated with alterations in the expression of CD32 and CD64.

Pathobiological implications of MUC4 in non-small-cell lung cancer.

PubMed

Majhi, Prabin Dhangada; Lakshmanan, Imayavaramban; Ponnusamy, Moorthy P; Jain, Maneesh; Das, Srustidhar; Kaur, Sukhwinder; Shimizu, Su Tomohiro; West, William W; Johansson, Sonny L; Smith, Lynette M; Yu, Fang; Rolle, Cleo E; Sharma, Poonam; Carey, George B; Batra, Surinder K; Ganti, Apar Kishor

2013-04-01

Altered expression of MUC4 plays an oncogenic role in various cancers, including pancreatic, ovarian, and breast. This study evaluates the expression and role of MUC4 in non-small-cell lung cancer (NSCLC). We used a paired system of MUC4-expressing (H292) and MUC4-nonexpressing (A549) NSCLC cell lines to analyze MUC4-dependent changes in growth rate, migration, and invasion using these sublines. We also evaluated the alterations of several tumor suppressor, proliferation, and metastasis markers with altered MUC4 expression. Furthermore, the association of MUC4 expression (by immunohistochemistry) in lung cancer samples with patient survival was evaluated. MUC4-expressing lung cancer cells demonstrated a less proliferative and metastatic phenotype. Up-regulation of p53 in MUC4-expressing lung cancer cells led to the accumulation of cells at the G2/M phase of cell cycle progression. MUC4 expression attenuated Akt activation and decreased the expression of Cyclins D1 and E, but increased the expression of p21 and p27. MUC4 expression abrogated cancer cell migration and invasion by altering N- & E-cadherin expression and FAK phosphorylation. A decrease in MUC4 expression was observed with increasing tumor stage (mean composite score: stage I, 2.4; stage II, 1.8; stage III, 1.4; and metastatic, 1.2; p = 0.0093). Maximal MUC4 expression was associated with a better overall survival (p = 0.042). MUC4 plays a tumor-suppressor role in NSCLC by altering p53 expression in NSCLC. Decrease in MUC4 expression in advanced tumor stages also seems to confirm the novel protective function of MUC4 in NSCLC.

Depletion of stromal cells expressing fibroblast activation protein-α from skeletal muscle and bone marrow results in cachexia and anemia

PubMed Central

Roberts, Edward W.; Deonarine, Andrew; Jones, James O.; Denton, Alice E.; Feig, Christine; Lyons, Scott K.; Espeli, Marion; Kraman, Matthew; McKenna, Brendan; Wells, Richard J.B.; Zhao, Qi; Caballero, Otavia L.; Larder, Rachel; Coll, Anthony P.; O’Rahilly, Stephen; Brindle, Kevin M.; Teichmann, Sarah A.; Tuveson, David A.

2013-01-01

Fibroblast activation protein-α (FAP) identifies stromal cells of mesenchymal origin in human cancers and chronic inflammatory lesions. In mouse models of cancer, they have been shown to be immune suppressive, but studies of their occurrence and function in normal tissues have been limited. With a transgenic mouse line permitting the bioluminescent imaging of FAP+ cells, we find that they reside in most tissues of the adult mouse. FAP+ cells from three sites, skeletal muscle, adipose tissue, and pancreas, have highly similar transcriptomes, suggesting a shared lineage. FAP+ cells of skeletal muscle are the major local source of follistatin, and in bone marrow they express Cxcl12 and KitL. Experimental ablation of these cells causes loss of muscle mass and a reduction of B-lymphopoiesis and erythropoiesis, revealing their essential functions in maintaining normal muscle mass and hematopoiesis, respectively. Remarkably, these cells are altered at these sites in transplantable and spontaneous mouse models of cancer-induced cachexia and anemia. Thus, the FAP+ stromal cell may have roles in two adverse consequences of cancer: their acquisition by tumors may cause failure of immunosurveillance, and their alteration in normal tissues contributes to the paraneoplastic syndromes of cachexia and anemia. PMID:23712428

High-resolution, label-free two-photon imaging of diseased human corneas

NASA Astrophysics Data System (ADS)

Batista, Ana; Breunig, Hans Georg; König, Aisada; Schindele, Andreas; Hager, Tobias; Seitz, Berthold; König, Karsten

2018-03-01

The diagnosis of corneal diseases may be improved by monitoring the metabolism of cells and the structural organization of the stroma using two-photon imaging (TPI). We used TPI to assess the differences between nonpathological (NP) human corneas and corneas diagnosed with either keratoconus, Acanthamoeba keratitis, or stromal corneal scars. Images were acquired using a custom-built five-dimensional laser-scanning microscope with a broadband sub-15 femtosecond near-infrared pulsed excitation laser and a 16-channel photomultiplier tube detector in combination with a time-correlated single photon counting module. Morphological alterations of epithelial cells were observed for all pathologies. Moreover, diseased corneas showed alterations to the cells' metabolism that were revealed using the NAD(P)H free to protein-bound ratios. The mean autofluorescence lifetime of the stroma and the organization of the collagen fibers were also significantly altered due to the pathologies. We demonstrate that TPI can be used to distinguish between NP and diseased human corneas, based not only on alterations of the cells' morphology, which can also be evaluated using current clinical devices, but on additional morphological and functional features such as the organization of the stroma and the cells' metabolism. Therefore, TPI could become an efficient tool for diagnosing corneal diseases and better understanding the biological processes of the diseases.

The alterations in the extracellular matrix composition guide the repair of damaged liver tissue

PubMed Central

Klaas, Mariliis; Kangur, Triin; Viil, Janeli; Mäemets-Allas, Kristina; Minajeva, Ave; Vadi, Krista; Antsov, Mikk; Lapidus, Natalia; Järvekülg, Martin; Jaks, Viljar

2016-01-01

While the cellular mechanisms of liver regeneration have been thoroughly studied, the role of extracellular matrix (ECM) in liver regeneration is still poorly understood. We utilized a proteomics-based approach to identify the shifts in ECM composition after CCl4 or DDC treatment and studied their effect on the proliferation of liver cells by combining biophysical and cell culture methods. We identified notable alterations in the ECM structural components (eg collagens I, IV, V, fibronectin, elastin) as well as in non-structural proteins (eg olfactomedin-4, thrombospondin-4, armadillo repeat-containing x-linked protein 2 (Armcx2)). Comparable alterations in ECM composition were seen in damaged human livers. The increase in collagen content and decrease in elastic fibers resulted in rearrangement and increased stiffness of damaged liver ECM. Interestingly, the alterations in ECM components were nonhomogenous and differed between periportal and pericentral areas and thus our experiments demonstrated the differential ability of selected ECM components to regulate the proliferation of hepatocytes and biliary cells. We define for the first time the alterations in the ECM composition of livers recovering from damage and present functional evidence for a coordinated ECM remodelling that ensures an efficient restoration of liver tissue. PMID:27264108

[Effects of infrasound on ultrastructure of testis cell in mice].

PubMed

Wei, Ya-Ning; Liu, Jing; Shu, Qing; Huang, Xiao-Feng; Chen, Jing-Zao

2002-01-01

To investigate the effects of infrasound on ultrastructure of testis in mouse. Twelve male BALB/C mice were randomly divided into three groups according to exposed duration on 1, 7 and 14 day. The mice were separately exposed to infrasound environment under 8 Hz/90 dB, 8 Hz/130 dB, 16 Hz/90 dB, 16 Hz/130 dB 2 hours per day. There was another control group which had three mice were separated into module with no infrasound. All the mice were killed on schedule. Then all the sections of testis were observed under electronic microscope. The alterations of structure and the chromatin were observed. Some acute alteration in one day group was found in testis cell, such as cellular denaturation and necrosis, intercellular edema, mitochondria swelling, liposome hyperplasia. When the infrasound was up to 8 Hz/130 dB, the damage showed seriously. In 7 and 14 day group, the acute alteration was gradually decreased. A plenty of abnormal sperm were found. And other alteration was chromatin condense. The effect of variational frequency was important in ultrastructure. The infrasound markedly effected to testicular cell morphology and secreting function. Infrasound will lead to the alteration of procreation in mouse.

E-Cadherin Acts as a Regulator of Transcripts Associated with a Wide Range of Cellular Processes in Mouse Embryonic Stem Cells

PubMed Central

Soncin, Francesca; Mohamet, Lisa; Ritson, Sarah; Hawkins, Kate; Bobola, Nicoletta; Zeef, Leo; Merry, Catherine L. R.; Ward, Christopher M.

2011-01-01

Background We have recently shown that expression of the cell adhesion molecule E-cadherin is required for LIF-dependent pluripotency of mouse embryonic stem (ES) cells. Methodology In this study, we have assessed global transcript expression in E-cadherin null (Ecad-/-) ES cells cultured in either the presence or absence of LIF and compared these to the parental cell line wtD3. Results We show that LIF has little effect on the transcript profile of Ecad-/- ES cells, with statistically significant transcript alterations observed only for Sp8 and Stat3. Comparison of Ecad-/- and wtD3 ES cells cultured in LIF demonstrated significant alterations in the transcript profile, with effects not only confined to cell adhesion and motility but also affecting, for example, primary metabolic processes, catabolism and genes associated with apoptosis. Ecad-/- ES cells share similar, although not identical, gene expression profiles to epiblast-derived pluripotent stem cells, suggesting that E-cadherin expression may inhibit inner cell mass to epiblast transition. We further show that Ecad-/- ES cells maintain a functional β-catenin pool that is able to induce β-catenin/TCF-mediated transactivation but, contrary to previous findings, do not display endogenous β-catenin/TCF-mediated transactivation. We conclude that loss of E-cadherin in mouse ES cells leads to significant transcript alterations independently of β-catenin/TCF transactivation. PMID:21779327

E-cadherin acts as a regulator of transcripts associated with a wide range of cellular processes in mouse embryonic stem cells.

PubMed

Soncin, Francesca; Mohamet, Lisa; Ritson, Sarah; Hawkins, Kate; Bobola, Nicoletta; Zeef, Leo; Merry, Catherine L R; Ward, Christopher M

2011-01-01

We have recently shown that expression of the cell adhesion molecule E-cadherin is required for LIF-dependent pluripotency of mouse embryonic stem (ES) cells. In this study, we have assessed global transcript expression in E-cadherin null (Ecad-/-) ES cells cultured in either the presence or absence of LIF and compared these to the parental cell line wtD3. We show that LIF has little effect on the transcript profile of Ecad-/- ES cells, with statistically significant transcript alterations observed only for Sp8 and Stat3. Comparison of Ecad-/- and wtD3 ES cells cultured in LIF demonstrated significant alterations in the transcript profile, with effects not only confined to cell adhesion and motility but also affecting, for example, primary metabolic processes, catabolism and genes associated with apoptosis. Ecad-/- ES cells share similar, although not identical, gene expression profiles to epiblast-derived pluripotent stem cells, suggesting that E-cadherin expression may inhibit inner cell mass to epiblast transition. We further show that Ecad-/- ES cells maintain a functional β-catenin pool that is able to induce β-catenin/TCF-mediated transactivation but, contrary to previous findings, do not display endogenous β-catenin/TCF-mediated transactivation. We conclude that loss of E-cadherin in mouse ES cells leads to significant transcript alterations independently of β-catenin/TCF transactivation.

Exercise and the Regulation of Immune Functions.

PubMed

Simpson, Richard J; Kunz, Hawley; Agha, Nadia; Graff, Rachel

2015-01-01

Exercise has a profound effect on the normal functioning of the immune system. It is generally accepted that prolonged periods of intensive exercise training can depress immunity, while regular moderate intensity exercise is beneficial. Single bouts of exercise evoke a striking leukocytosis and a redistribution of effector cells between the blood compartment and the lymphoid and peripheral tissues, a response that is mediated by increased hemodynamics and the release of catecholamines and glucocorticoids following the activation of the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis. Single bouts of prolonged exercise may impair T-cell, NK-cell, and neutrophil function, alter the Type I and Type II cytokine balance, and blunt immune responses to primary and recall antigens in vivo. Elite athletes frequently report symptoms associated with upper respiratory tract infections (URTI) during periods of heavy training and competition that may be due to alterations in mucosal immunity, particularly reductions in secretory immunoglobulin A. In contrast, single bouts of moderate intensity exercise are "immuno-enhancing" and have been used to effectively increase vaccine responses in "at-risk" patients. Improvements in immunity due to regular exercise of moderate intensity may be due to reductions in inflammation, maintenance of thymic mass, alterations in the composition of "older" and "younger" immune cells, enhanced immunosurveillance, and/or the amelioration of psychological stress. Indeed, exercise is a powerful behavioral intervention that has the potential to improve immune and health outcomes in the elderly, the obese, and patients living with cancer and chronic viral infections such as HIV. © 2015 Elsevier Inc. All rights reserved.

Effect of gel re-organization and tensional forces on alpha2beta1 integrin levels in dermal fibroblasts.

PubMed

Jenkins, G; Redwood, K L; Meadows, L; Green, M R

1999-07-01

Mechanical forces are known to play an important role in regulating cell function in a wide range of biological systems. This is of particular relevance to dermal fibroblast function, given that the skin is known to be held under an intrinsic natural tension. To understand more about the generation of force by dermal fibroblasts and their ability to respond to changes in it, we have studied the role of the beta1 integrin receptors expressed by dermal fibroblasts in their ability to generate tensional forces within a collagen type I matrix and the effect of altered tensional force on integrin expression by dermal fibroblasts. Using a purpose-built culture force monitor, function-blocking antibodies directed towards the beta1 receptors dramatically reduced the tensional forces generated by dermal fibroblasts in a 3D collagen I matrix. However, the specific involvement of alpha1 or alpha2 subunits could not be demonstrated. Analysis of cellular response demonstrated that cells isolated from contracting collagen gels expressed fourfold higher levels of alpha2 mRNA than cells isolated from fully restrained gels. The levels of beta1 messenger RNA were relatively unaffected by reductions in force. Cells exposed to single reductions in force, however, did not exhibit alterations in either alpha1 or beta1 mRNA levels. We propose, therefore that alpha2beta1 integrin receptor levels in dermal fibroblasts are not altered in response to single reductions of gel tension, but do change following a continual change in force and associated matrix re-organization

Proteinase-Activated Receptor 1 (PAR1) Regulates Leukemic Stem Cell Functions

PubMed Central

Bäumer, Nicole; Krause, Annika; Köhler, Gabriele; Lettermann, Stephanie; Evers, Georg; Hascher, Antje; Bäumer, Sebastian; Berdel, Wolfgang E.

2014-01-01

External signals that are mediated by specific receptors determine stem cell fate. The thrombin receptor PAR1 plays an important role in haemostasis, thrombosis and vascular biology, but also in tumor biology and angiogenesis. Its expression and function in hematopoietic stem cells is largely unknown. Here, we analyzed expression and function of PAR1 in primary hematopoietic cells and their leukemic counterparts. AML patients' blast cells expressed much lower levels of PAR1 mRNA and protein than CD34+ progenitor cells. Constitutive Par1-deficiency in adult mice did not affect engraftment or stem cell potential of hematopoietic cells. To model an AML with Par1-deficiency, we retrovirally introduced the oncogene MLL-AF9 in wild type and Par1−/− hematopoietic progenitor cells. Par1-deficiency did not alter initial leukemia development. However, the loss of Par1 enhanced leukemic stem cell function in vitro and in vivo. Re-expression of PAR1 in Par1−/− leukemic stem cells delayed leukemogenesis in vivo. These data indicate that Par1 contributes to leukemic stem cell maintenance. PMID:24740120

Proteinase-Activated Receptor 1 (PAR1) regulates leukemic stem cell functions.

PubMed

Bäumer, Nicole; Krause, Annika; Köhler, Gabriele; Lettermann, Stephanie; Evers, Georg; Hascher, Antje; Bäumer, Sebastian; Berdel, Wolfgang E; Müller-Tidow, Carsten; Tickenbrock, Lara

2014-01-01

External signals that are mediated by specific receptors determine stem cell fate. The thrombin receptor PAR1 plays an important role in haemostasis, thrombosis and vascular biology, but also in tumor biology and angiogenesis. Its expression and function in hematopoietic stem cells is largely unknown. Here, we analyzed expression and function of PAR1 in primary hematopoietic cells and their leukemic counterparts. AML patients' blast cells expressed much lower levels of PAR1 mRNA and protein than CD34+ progenitor cells. Constitutive Par1-deficiency in adult mice did not affect engraftment or stem cell potential of hematopoietic cells. To model an AML with Par1-deficiency, we retrovirally introduced the oncogene MLL-AF9 in wild type and Par1-/- hematopoietic progenitor cells. Par1-deficiency did not alter initial leukemia development. However, the loss of Par1 enhanced leukemic stem cell function in vitro and in vivo. Re-expression of PAR1 in Par1-/- leukemic stem cells delayed leukemogenesis in vivo. These data indicate that Par1 contributes to leukemic stem cell maintenance.

Immunometabolism in systemic lupus erythematosus.

PubMed

Morel, Laurence

2017-05-01

Systemic lupus erythematosus (SLE) is an autoimmune disease mediated by pathogenic autoantibodies directed against nucleoprotein complexes. Beyond the activation of autoreactive B cells, this process involves dysregulation in many other types of immune cells, including CD4 + T cells, dendritic cells, macrophages and neutrophils. Metabolic substrate utilization and integration of cues from energy sensors are critical checkpoints of effector functions in the immune system, with common as well as cell-specific programmes. Patients with SLE and lupus-prone mice present with activated metabolism of CD4 + T cells, and the use of metabolic inhibitors to normalize these features is associated with therapeutic effects. Far less is known about the metabolic requirements of B cells and myeloid cells in SLE. This article reviews current knowledge of the alterations in metabolism of immune cells in patients with SLE and mouse models of lupus in the context of what is known about the metabolic regulation of these cells during normal immune responses. How these alterations might contribute to lupus pathogenesis and how they can be targeted therapeutically are also discussed.

Circulating exosomes potentiate tumor malignant properties in a mouse model of chronic sleep fragmentation

PubMed Central

Khalyfa, Abdelnaby; Almendros, Isaac; Gileles-Hillel, Alex; Akbarpour, Mahzad; Trzepizur, Wojciech; Mokhlesi, Babak; Huang, Lei; Andrade, Jorge; Farré, Ramon; Gozal, David

2016-01-01

Background Chronic sleep fragmentation (SF) increases cancer aggressiveness in mice. Exosomes exhibit pleiotropic biological functions, including immune regulatory functions, antigen presentation, intracellular communication and inter-cellular transfer of RNA and proteins. We hypothesized that SF-induced alterations in biosynthesis and cargo of plasma exosomes may affect tumor cell properties. Results SF-derived exosomes increased tumor cell proliferation (~13%), migration (~2.3-fold) and extravasation (~10%) when compared to exosomes from SC-exposed mice. Similarly, Pre exosomes from OSA patients significantly enhanced proliferation and migration of human adenocarcinoma cells compared to Post. SF-exosomal cargo revealed 3 discrete differentially expressed miRNAs, and exploration of potential mRNA targets in TC1 tumor cells uncovered 132 differentially expressed genes that encode for multiple cancer-related pathways. Methods Plasma-derived exosomes from C57/B6 mice exposed to 6 wks of SF or sleep control (SC), and from adult human patients with obstructive sleep apnea (OSA) before (Pre) and after adherent treatment for 6 wks (Post) were co-cultured with mouse lung TC1 or human adenocarcinoma tumor cell lines, respectively. Proliferation, migration, invasion, endothelial barrier integrity and extravasation assays of tumor cells were performed. Plasma mouse exosomal miRNAs were profiled with arrays, and transcriptomic assessments of TC1 cells exposed to SF or SC exosomes were conducted to identify gene targets. Conclusions Chronic SF induces alterations in exosomal miRNA cargo that alter the biological properties of TC1 lung tumor cells to enhance their proliferative, migratory and extravasation properties, and similar findings occur in OSA patients, in whom SF is a constitutive component of their sleep disorder. Thus, exosomes could participate, at least in part, in the adverse cancer outcomes observed in OSA. PMID:27419627

Exosomes derived from B16F0 melanoma cells alter the transcriptome of cytotoxic T cells that impacts mitochondrial respiration.

PubMed

Bland, Cassidy L; Byrne-Hoffman, Christina N; Fernandez, Audry; Rellick, Stephanie L; Deng, Wentao; Klinke, David J

2018-03-01

While recent clinical studies demonstrate the promise of cancer immunotherapy, a barrier for broadening the clinical benefit is identifying how tumors locally suppress cytotoxic immunity. As an emerging mode of intercellular communication, exosomes secreted by malignant cells can deliver a complex payload of coding and noncoding RNA to cells within the tumor microenvironment. Here, we quantified the RNA payload within tumor-derived exosomes and the resulting dynamic transcriptomic response to cytotoxic T cells upon exosome delivery to better understand how tumor-derived exosomes can alter immune cell function. Exosomes derived from B16F0 melanoma cells were enriched for a subset of coding and noncoding RNAs that did not reflect the abundance in the parental cell. Upon exosome delivery, RNAseq revealed the dynamic changes in the transcriptome of CTLL2 cytotoxic T cells. In analyzing transiently coexpressed gene clusters, pathway enrichment suggested that the B16F0 exosomal payload altered mitochondrial respiration, which was confirmed independently, and upregulated genes associated with the Notch signaling pathway. Interestingly, exosomal miRNA appeared to have no systematic effect on downregulating target mRNA levels. Gene expression data are available in the GEO database under the accession SuperSeries number GSE102951. © 2018 Federation of European Biochemical Societies.

Expression and high glucose-mediated regulation of K+ channel interacting protein 3 (KChIP3) and KV4 channels in retinal Müller glial cells.

PubMed

Chavira-Suárez, Erika; Sandoval, Alejandro; Felix, Ricardo; Lamas, Mónica

2011-01-14

Normal vision depends on the correct function of retinal neurons and glia and it is impaired in the course of diabetic retinopathy. Müller cells, the main glial cells of the retina, suffer morphological and functional alterations during diabetes participating in the pathological retinal dysfunction. Recently, we showed that Müller cells express the pleiotropic protein potassium channel interacting protein 3 (KChIP3), an integral component of the voltage-gated K(+) channels K(V)4. Here, we sought to analyze the role of KChIP3 in the molecular mechanisms underlying hyperglycemia-induced phenotypic changes in the glial elements of the retina. The expression and function of KChIp3 was analyzed in vitro in rat Müller primary cultures grown under control (5.6 mM) or high glucose (25 mM) (diabetic-like) conditions. We show the up-regulation of KChIP3 expression in Müller cell cultures under high glucose conditions and demonstrate a previously unknown interaction between the K(V)4 channel and KChIP3 in Müller cells. We show evidence for the expression of a 4-AP-sensitive transient outward voltage-gated K(+) current and an alteration in the inactivation of the macroscopic outward K(+) currents expressed in high glucose-cultured Müller cells. Our data support the notion that induction of KChIP3 and functional changes of K(V)4 channels in Müller cells could exert a physiological role in the onset of diabetic retinopathy. Copyright © 2010 Elsevier Inc. All rights reserved.

The effect of pro-inflammatory cytokines on immunophenotype, differentiation capacity and immunomodulatory functions of human mesenchymal stem cells.

PubMed

Pourgholaminejad, Arash; Aghdami, Nasser; Baharvand, Hossein; Moazzeni, Seyed Mohammad

2016-09-01

Mesenchymal stem cells (MSCs), as cells with potential clinical utilities, have demonstrated preferential incorporation into inflammation sites. Immunophenotype and immunomodulatory functions of MSCs could alter by inflamed-microenvironments due to the local pro-inflammatory cytokine milieu. A major cellular mediator with specific function in promoting inflammation and pathogenicity of autoimmunity are IL-17-producing T helper 17 (Th17) cells that polarize in inflamed sites in the presence of pro-inflammatory cytokines such as Interleukin-1β (IL-1β), IL-6 and IL-23. Since MSCs are promising candidate for cell-based therapeutic strategies in inflammatory and autoimmune diseases, Th17 cell polarizing factors may alter MSCs phenotype and function. In this study, human bone-marrow-derived MSCs (BM-MSC) and adipose tissue-derived MSCs (AD-MSC) were cultured with or without IL-1β, IL-6 and IL-23 as pro-inflammatory cytokines. The surface markers and their differentiation capacity were measured in cytokine-untreated and cytokine-treated MSCs. MSCs-mediated immunomodulation was analyzed by their regulatory effects on mixed lymphocyte reaction (MLR) and the level of IL-10, TGF-β, IL-4, IFN-γ and TNF-α production as immunomodulatory cytokines. Pro-inflammatory cytokines showed no effect on MSCs morphology, immunophenotype and co-stimulatory molecules except up-regulation of CD45. Adipogenic and osteogenic differentiation capacity increased in CD45+ MSCs. Moreover, cytokine-treated MSCs preserved the suppressive ability of allogeneic T cell proliferation and produced higher level of TGF-β and lower level of IL-4. We concluded pro-inflammatory cytokines up-regulate the efficacy of MSCs in cell-based therapy of degenerative, inflammatory and autoimmune disorders. Copyright © 2016. Published by Elsevier Ltd.

Thermo-responsive cell culture carrier: Effects on macrophage functionality and detachment efficiency.

PubMed

Rennert, Knut; Nitschke, Mirko; Wallert, Maria; Keune, Natalie; Raasch, Martin; Lorkowski, Stefan; Mosig, Alexander S

2017-01-01

Harvesting cultivated macrophages for tissue engineering purposes by enzymatic digestion of cell adhesion molecules can potentially result in unintended activation, altered function, or behavior of these cells. Thermo-responsive polymer is a promising tool that allows for gentle macrophage detachment without artificial activation prior to subculture within engineered tissue constructs. We therefore characterized different species of thermo-responsive polymers for their suitability as cell substrate and to mediate gentle macrophage detachment by temperature shift. Primary human monocyte- and THP-1-derived macrophages were cultured on thermo-responsive polymers and characterized for phagocytosis and cytokine secretion in response to lipopolysaccharide stimulation. We found that both cell types differentially respond in dependence of culture and stimulation on thermo-responsive polymers. In contrast to THP-1 macrophages, primary monocyte-derived macrophages showed no signs of impaired viability, artificial activation, or altered functionality due to culture on thermo-responsive polymers compared to conventional cell culture. Our study demonstrates that along with commercially available UpCell carriers, two other thermo-responsive polymers based on poly(vinyl methyl ether) blends are attractive candidates for differentiation and gentle detachment of primary monocyte-derived macrophages. In summary, we observed similar functionality and viability of primary monocyte-derived macrophages cultured on thermo-responsive polymers compared to standard cell culture surfaces. While this first generation of custom-made thermo-responsive polymers does not yet outperform standard culture approaches, our results are very promising and provide the basis for exploiting the unique advantages offered by custom-made thermo-responsive polymers to further improve macrophage culture and recovery in the future, including the covalent binding of signaling molecules and the reduction of centrifugation and washing steps. Optimizing these and other benefits of thermo-responsive polymers could greatly improve the culture of macrophages for tissue engineering applications.

Analyses of Dynein Heavy Chain Mutations Reveal Complex Interactions Between Dynein Motor Domains and Cellular Dynein Functions

PubMed Central

Sivagurunathan, Senthilkumar; Schnittker, Robert R.; Razafsky, David S.; Nandini, Swaran; Plamann, Michael D.; King, Stephen J.

2012-01-01

Cytoplasmic dynein transports cargoes for a variety of crucial cellular functions. However, since dynein is essential in most eukaryotic organisms, the in-depth study of the cellular function of dynein via genetic analysis of dynein mutations has not been practical. Here, we identify and characterize 34 different dynein heavy chain mutations using a genetic screen of the ascomycete fungus Neurospora crassa, in which dynein is nonessential. Interestingly, our studies show that these mutations segregate into five different classes based on the in vivo localization of the mutated dynein motors. Furthermore, we have determined that the different classes of dynein mutations alter vesicle trafficking, microtubule organization, and nuclear distribution in distinct ways and require dynactin to different extents. In addition, biochemical analyses of dynein from one mutant strain show a strong correlation between its in vitro biochemical properties and the aberrant intracellular function of that altered dynein. When the mutations were mapped to the published dynein crystal structure, we found that the three-dimensional structural locations of the heavy chain mutations were linked to particular classes of altered dynein functions observed in cells. Together, our data indicate that the five classes of dynein mutations represent the entrapment of dynein at five separate points in the dynein mechanochemical and transport cycles. We have developed N. crassa as a model system where we can dissect the complexities of dynein structure, function, and interaction with other proteins with genetic, biochemical, and cell biological studies. PMID:22649085

Cellular energy metabolism in T-lymphocytes.

PubMed

Gaber, Timo; Strehl, Cindy; Sawitzki, Birgit; Hoff, Paula; Buttgereit, Frank

2015-01-01

Energy homeostasis is a hallmark of cell survival and maintenance of cell function. Here we focus on the impact of cellular energy metabolism on T-lymphocyte differentiation, activation, and function in health and disease. We describe the role of transcriptional and posttranscriptional regulation of lymphocyte metabolism on immune functions of T cells. We also summarize the current knowledge about T-lymphocyte adaptations to inflammation and hypoxia, and the impact on T-cell behavior of pathophysiological hypoxia (as found in tumor tissue, chronically inflamed joints in rheumatoid arthritis and during bone regeneration). A better understanding of the underlying mechanisms that control immune cell metabolism and immune response may provide therapeutic opportunities to alter the immune response under conditions of either immunosuppression or inflammation, potentially targeting infections, vaccine response, tumor surveillance, autoimmunity, and inflammatory disorders.

Altered Expression of Wnt Signaling Pathway Components in Osteogenesis of Mesenchymal Stem Cells in Osteoarthritis Patients.

PubMed

Tornero-Esteban, Pilar; Peralta-Sastre, Ascensión; Herranz, Eva; Rodríguez-Rodríguez, Luis; Mucientes, Arkaitz; Abásolo, Lydia; Marco, Fernando; Fernández-Gutiérrez, Benjamín; Lamas, José Ramón

2015-01-01

Osteoarthritis (OA) is characterized by altered homeostasis of joint cartilage and bone, whose functional properties rely on chondrocytes and osteoblasts, belonging to mesenchymal stem cells (MSCs). WNT signaling acts as a hub integrating and crosstalking with other signaling pathways leading to the regulation of MSC functions. The aim of this study was to evaluate the existence of a differential signaling between Healthy and OA-MSCs during osteogenesis. MSCs of seven OA patients and six healthy controls were isolated, characterised and expanded. During in vitro osteogenesis, cells were recovered at days 1, 10 and 21. RNA and protein content was obtained. Expression of WNT pathway genes was evaluated using RT-qPCR. Functional studies were also performed to study the MSC osteogenic commitment and functional and post-traslational status of β-catenin and several receptor tyrosine kinases. Several genes were downregulated in OA-MSCs during osteogenesis in vitro. These included soluble Wnts, inhibitors, receptors, co-receptors, several kinases and transcription factors. Basal levels of β-catenin were higher in OA-MSCs, but calcium deposition and expression of osteogenic genes was similar between Healthy and OA-MSCs. Interestingly an increased phosphorylation of p44/42 MAPK (ERK1/2) signaling node was present in OA-MSCs. Our results point to the existence in OA-MSCs of alterations in expression of Wnt pathway components during in vitro osteogenesis that are partially compensated by post-translational mechanisms modulating the function of other pathways. We also point the relevance of other signaling pathways in OA pathophysiology suggesting their role in the maintenance of joint homeostasis through modulation of MSC osteogenic potential.

Methyl-parathion decreases sperm function and fertilization capacity after targeting spermatocytes and maturing spermatozoa

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

Pina-Guzman, Belem; Sanchez-Gutierrez, M.; Marchetti, Francesco

Paternal germline exposure to organophosphorous pesticides (OP) has been associated with reproductive failures and adverse effects in the offspring. Methyl parathion (Me-Pa), a worldwide-used OP, has reproductive adverse effects and is genotoxic to sperm. Oxidative damage has been involved in the genotoxic and reproductive effects of OP. The purpose of this study was to determine the effects of Me-Pa on spermatozoa function and ability to fertilize. Male mice were exposed to Me-Pa (20 mg/kg bw, i.p.) and spermatozoa from epididymis-vas deferens were collected at 7 or 28 days post-treatment (dpt) to assess the effects on maturing spermatozoa and spermatocytes, respectively.more » DNA damage was evaluated by nick translation (NT-positive cells) and SCSA (percentDFI); lipoperoxidation (LPO) by malondialdehyde production; sperm function by spontaneous- and induced-acrosome reactions (AR); mitochondrial membrane potential (MMP) by using the JC-1 flurochrome; and, fertilization ability by an in vitro assay and in vivo mating. Results showed alterations in DNA integrity (percentDFI and NT-positive cells) at 7 and 28 dpt, in addition to decreased sperm quality and a decrease in induced-AR; reduced MMP and LPO was observed only at 7 dpt. We found negative correlations between LPO and all sperm alterations. Altered sperm functional parameters were associated with reduced fertilization rates at both times, evaluated either in vitro or in vivo. These results show that Me-Pa exposure of maturing spermatozoa and spermatocytes affects many sperm functional parameters that result in a decreased fertilizing capacity. Oxidative stress seems to be a likely mechanism ofthe detrimental effects of Me-Pa in male germ cells.« less

Plant Cell Adaptive Responses to Microgravity

NASA Astrophysics Data System (ADS)

Kordyum, Elizabeth; Kozeko, Liudmyla; Talalaev, Alexandr

Microgravity is an abnormal environmental condition that plays no role in the functioning of biosphere. Nevertheless, the chronic effect of microgravity in space flight as an unfamiliar factor does not prevent the development of adaptive reactions at the cellular level. In real microgravity in space flight under the more or less optimal conditions for plant growing, namely temperature, humidity, CO2, light intensity and directivity in the hardware angiosperm plants perform an “reproductive imperative”, i.e. they flower, fruit and yield viable seeds. It is known that cells of a multicellular organism not only take part on reactions of the organism but also carry out processes that maintain their integrity. In light of these principles, the problem of the identification of biochemical, physiological and structural patterns that can have adaptive significance at the cellular and subcellular level in real and simulated microgravity is considered. Cytological studies of plants developing in real and simulated microgravity made it possible to establish that the processes of mitosis, cytokinesis, and tissue differentiation of vegetative and generative organs are largely normal. At the same time, under microgravity, essential reconstruction in the structural and functional organization of cell organelles and cytoskeleton, as well as changes in cell metabolism and homeostasis have been described. In addition, new interesting data concerning the influence of altered gravity on lipid peroxidation intensity, the level of reactive oxygen species, and antioxidant system activity, just like on the level of gene expression and synthesis of low-molecular and high-molecular heat shock proteins were recently obtained. So, altered gravity caused time-dependent increasing of the HSP70 and HSP90 levels in cells, that may indicate temporary strengthening of their functional loads that is necessary for re-establish a new cellular homeostasis. Relative qPCR results showed that simulated microgravity and temperature elevation have different effects on the small HSP genes belonging to subfamilies with different subcellular localization: cytosol/nucleus - PsHSP17.1-CII and PsHSP18.1-CI, cloroplasts - PsHSP26.2-Cl, endoplasmatic reticulum - PsHSP22.7-ER and mitochondria - PsHSP22.9-M: unlike high temperature, clinorotation does not cause denaturation of cell proteins, that confirms the sHSP chaperone function. Dynamics of investigated gene expression in pea seedlings growing 5 days after seed germination under clinorotation was similar to that in the stationary control. Similar patterns in dynamics of sHSP gene expression in the stationary control and under clinorotation may be one of mechanisms providing plant adaptation to simulated microgravity. It is pointed that plant cell responses in microgravity and under clinorotation vary according to growth phase, physiological state, and taxonomic position of the object. At the same time, the responses have, to some degree, a similar character reflecting the changes in cell organelle functional load. Thus, next certain changes in the structure and function of plant cells may be considered as adaptive: 1) an increase in the unsaturated fatty acid content in the plasmalemma, 2) rearrangements of organelle ultrastructure and an increase in their functional load, 3) an increase in cortical F-actin under destabilization of tubulin microtubules, 4) the level of gene expression and synthesis of heat shock proteins, 5) alterations of the enzyme and antioxidant system activity. The dynamics of these patterns demonstrated that the adaptation occurs on the principle of self-regulating systems in the limits of physiological norm reaction. The very importance of changed expression of genes involved in different cellular processes, especially HSP genes, in cell adaptation to altered gravity is discussed.

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

Smirnov, Sergey V.; Harbacheuski, Ryhor; Lewis-Antes, Anita

Mesenchymal stem cells (MSCs) in bone marrow (BM) regulate the differentiation and proliferation of adjacent hematopoietic precursor cells and contribute to the regeneration of mesenchymal tissues, including bone, cartilage, fat and connective tissue. BM is an important site for the pathogenesis of human cytomegalovirus (HCMV) where the virus establishes latency in hematopoietic progenitors and can transmit after reactivation to neighboring cells. Here we demonstrate that BM-MSCs are permissive to productive HCMV infection, and that HCMV alters the function of MSCs: (i) by changing the repertoire of cell surface molecules in BM-MSCs, HCMV modifies the pattern of interaction between BM-MSCs andmore » hematopoietic cells; (ii) HCMV infection of BM-MSCs undergoing adipogenic or osteogenic differentiation impaired the process of differentiation. Our results suggest that by altering BM-MSC biology, HCMV may contribute to the development of various diseases.« less

Germline Genetic IKZF1 Variation and Predisposition to Childhood Acute Lymphoblastic Leukemia.

PubMed

Churchman, Michelle L; Qian, Maoxiang; Te Kronnie, Geertruy; Zhang, Ranran; Yang, Wenjian; Zhang, Hui; Lana, Tobia; Tedrick, Paige; Baskin, Rebekah; Verbist, Katherine; Peters, Jennifer L; Devidas, Meenakshi; Larsen, Eric; Moore, Ian M; Gu, Zhaohui; Qu, Chunxu; Yoshihara, Hiroki; Porter, Shaina N; Pruett-Miller, Shondra M; Wu, Gang; Raetz, Elizabeth; Martin, Paul L; Bowman, W Paul; Winick, Naomi; Mardis, Elaine; Fulton, Robert; Stanulla, Martin; Evans, William E; Relling, Mary V; Pui, Ching-Hon; Hunger, Stephen P; Loh, Mignon L; Handgretinger, Rupert; Nichols, Kim E; Yang, Jun J; Mullighan, Charles G

2018-05-14

Somatic genetic alterations of IKZF1, which encodes the lymphoid transcription factor IKAROS, are common in high-risk B-progenitor acute lymphoblastic leukemia (ALL) and are associated with poor prognosis. Such alterations result in the acquisition of stem cell-like features, overexpression of adhesion molecules causing aberrant cell-cell and cell-stroma interaction, and decreased sensitivity to tyrosine kinase inhibitors. Here we report coding germline IKZF1 variation in familial childhood ALL and 0.9% of presumed sporadic B-ALL, identifying 28 unique variants in 45 children. The majority of variants adversely affected IKZF1 function and drug responsiveness of leukemic cells. These results identify IKZF1 as a leukemia predisposition gene, and emphasize the importance of germline genetic variation in the development of both familial and sporadic ALL. Copyright © 2018 Elsevier Inc. All rights reserved.

Role of Aquaporin 0 in lens biomechanics

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

Sindhu Kumari, S.; Gupta, Neha; Shiels, Alan

Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showedmore » the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5{sup −/−}), AQP0 KO (heterozygous KO: AQP0{sup +/−}; homozygous KO: AQP0{sup −/−}; all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0{sup +/−} lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and together they help to confer fiber cell shape, architecture and integrity. To our knowledge, this is the first report identifying the involvement of an aquaporin in lens biomechanics. Since accommodation is required in human lenses for proper focusing, alteration in the adhesion and/or water channel functions of AQP0 could contribute to presbyopia. - Highlights: • AQP0 aids in lens biomechanics. • AQP0 provides lens stiffness. • AQP0 is critical for lens transparency. • AQP0 could play a significant role in lens accommodation in human. • Alteration in the function(s) of lens AQP0 could lead to presbyopia.« less

AML1/ETO accelerates cell migration and impairs cell-to-cell adhesion and homing of hematopoietic stem/progenitor cells

PubMed Central

Saia, Marco; Termanini, Alberto; Rizzi, Nicoletta; Mazza, Massimiliano; Barbieri, Elisa; Valli, Debora; Ciana, Paolo; Gruszka, Alicja M.; Alcalay, Myriam

2016-01-01

The AML1/ETO fusion protein found in acute myeloid leukemias functions as a transcriptional regulator by recruiting co-repressor complexes to its DNA binding site. In order to extend the understanding of its role in preleukemia, we expressed AML1/ETO in a murine immortalized pluripotent hematopoietic stem/progenitor cell line, EML C1, and found that genes involved in functions such as cell-to-cell adhesion and cell motility were among the most significantly regulated as determined by RNA sequencing. In functional assays, AML1/ETO-expressing cells showed a decrease in adhesion to stromal cells, an increase of cell migration rate in vitro, and displayed an impairment in homing and engraftment in vivo upon transplantation into recipient mice. Our results suggest that AML1/ETO expression determines a more mobile and less adherent phenotype in preleukemic cells, therefore altering the interaction with the hematopoietic niche, potentially leading to the migration across the bone marrow barrier and to disease progression. PMID:27713544

Parkin Modulates Endosomal Organization and Function of the Endo-Lysosomal Pathway.

PubMed

Song, Pingping; Trajkovic, Katarina; Tsunemi, Taiji; Krainc, Dimitri

2016-02-24

Mutations in PARK2 (parkin), which encodes Parkin protein, an E3 ubiquitin ligase, are associated with autosomal recessive early-onset Parkinson's disease (PD). While several studies implicated Parkin in the regulation of mitophagy and proteasomal degradation, the precise mechanism leading to neurodegeneration upon Parkin loss of function remains incompletely understood. In this study, we found that Parkin modulates the endocytic pathway through the regulation of endosomal structure and function. We showed that loss of Parkin function led to decreased endosomal tubulation and membrane association of vesicle protein sorting 35 (VPS35) and sorting nexin 1 (SNX1), as well as decreased mannose 6 phosphate receptor (M6PR), suggesting the impairment of retromer pathway in Parkin-deficient cells. We also found increased formation of intraluminal vesicles coupled with enhanced release of exosomes in the presence of mutant Parkin. To elucidate the molecular mechanism of these alterations in the endocytic pathway in Parkin-deficient cells, we found that Parkin regulates the levels and activity of Rab7 by promoting its ubiquitination on lysine 38 residue. Both endogenous Rab7 in Parkin-deficient cells and overexpressed K38 R-Rab7 mutant displayed decreased effector binding and membrane association. Furthermore, overexpression of K38R-Rab7 in HEK293 cells phenocopied the increased secretion of exosomes observed in Parkin-deficient cells, suggesting that Rab7 deregulation may be at least partially responsible for the endocytic phenotype observed in Parkin-deficient cells. These findings establish a role for Parkin in regulating the endo-lysosomal pathway and retromer function and raise the possibility that alterations in these pathways contribute to the development of pathology in Parkin-linked Parkinson's disease. Copyright © 2016 the authors 0270-6474/16/362425-13$15.00/0.

Electrophysiology of glioma: a Rho GTPase-activating protein reduces tumor growth and spares neuron structure and function.

PubMed

Vannini, Eleonora; Olimpico, Francesco; Middei, Silvia; Ammassari-Teule, Martine; de Graaf, Erik L; McDonnell, Liam; Schmidt, Gudula; Fabbri, Alessia; Fiorentini, Carla; Baroncelli, Laura; Costa, Mario; Caleo, Matteo

2016-12-01

Glioblastomas are the most aggressive type of brain tumor. A successful treatment should aim at halting tumor growth and protecting neuronal cells to prevent functional deficits and cognitive deterioration. Here, we exploited a Rho GTPase-activating bacterial protein toxin, cytotoxic necrotizing factor 1 (CNF1), to interfere with glioma cell growth in vitro and vivo. We also investigated whether this toxin spares neuron structure and function in peritumoral areas. We performed a microarray transcriptomic and in-depth proteomic analysis to characterize the molecular changes triggered by CNF1 in glioma cells. We also examined tumor cell senescence and growth in vehicle- and CNF1-treated glioma-bearing mice. Electrophysiological and morphological techniques were used to investigate neuronal alterations in peritumoral cortical areas. Administration of CNF1 triggered molecular and morphological hallmarks of senescence in mouse and human glioma cells in vitro. CNF1 treatment in vivo induced glioma cell senescence and potently reduced tumor volumes. In peritumoral areas of glioma-bearing mice, neurons showed a shrunken dendritic arbor and severe functional alterations such as increased spontaneous activity and reduced visual responsiveness. CNF1 treatment enhanced dendritic length and improved several physiological properties of pyramidal neurons, demonstrating functional preservation of the cortical network. Our findings demonstrate that CNF1 reduces glioma volume while at the same time maintaining the physiological and structural properties of peritumoral neurons. These data indicate a promising strategy for the development of more effective antiglioma therapies. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Differential lactate and cholesterol synthetic activities in XY and XX Sertoli cells.

PubMed

Shishido, Yurina; Baba, Takashi; Sato, Tetsuya; Shima, Yuichi; Miyabayashi, Kanako; Inoue, Miki; Akiyama, Haruhiko; Kimura, Hiroshi; Kanai, Yoshiakira; Ishihara, Yasuhiro; Haraguchi, Shogo; Miyazaki, Akira; Rozman, Damjana; Yamazaki, Takeshi; Choi, Man-Ho; Ohkawa, Yasuyuki; Suyama, Mikita; Morohashi, Ken-Ichirou

2017-02-02

SRY, a sex-determining gene, induces testis development in chromosomally female (XX) individuals. However, mouse XX Sertoli cells carrying Sry (XX/Sry Sertoli cells) are incapable of fully supporting germ cell development, even when the karyotype of the germ cells is XY. While it has therefore been assumed that XX/Sry Sertoli cells are not functionally equivalent to XY Sertoli cells, it has remained unclear which specific functions are affected. To elucidate the functional difference, we compared the gene expression of XY and XX/Sry Sertoli cells. Lactate and cholesterol metabolisms, essential for nursing the developing germ cells, were down-regulated in XX/Sry cells, which appears to be caused at least in part by the differential expression of histone modification enzymes SMCX/SMCY (H3K4me3 demethylase) and UTX/UTY (H3K27me3 demethylase) encoded by the sex chromosomes. We suggest that down-regulation of lactate and cholesterol metabolism that may be due to altered epigenetic modification affects the nursing functions of XX/Sry Sertoli cells.

Differential lactate and cholesterol synthetic activities in XY and XX Sertoli cells

PubMed Central

Shishido, Yurina; Baba, Takashi; Sato, Tetsuya; Shima, Yuichi; Miyabayashi, Kanako; Inoue, Miki; Akiyama, Haruhiko; Kimura, Hiroshi; Kanai, Yoshiakira; Ishihara, Yasuhiro; Haraguchi, Shogo; Miyazaki, Akira; Rozman, Damjana; Yamazaki, Takeshi; Choi, Man-Ho; Ohkawa, Yasuyuki; Suyama, Mikita; Morohashi, Ken-ichirou

2017-01-01

SRY, a sex-determining gene, induces testis development in chromosomally female (XX) individuals. However, mouse XX Sertoli cells carrying Sry (XX/Sry Sertoli cells) are incapable of fully supporting germ cell development, even when the karyotype of the germ cells is XY. While it has therefore been assumed that XX/Sry Sertoli cells are not functionally equivalent to XY Sertoli cells, it has remained unclear which specific functions are affected. To elucidate the functional difference, we compared the gene expression of XY and XX/Sry Sertoli cells. Lactate and cholesterol metabolisms, essential for nursing the developing germ cells, were down-regulated in XX/Sry cells, which appears to be caused at least in part by the differential expression of histone modification enzymes SMCX/SMCY (H3K4me3 demethylase) and UTX/UTY (H3K27me3 demethylase) encoded by the sex chromosomes. We suggest that down-regulation of lactate and cholesterol metabolism that may be due to altered epigenetic modification affects the nursing functions of XX/Sry Sertoli cells. PMID:28150810

PERCHLOROETHYLENE (PERC) INHIBITS FUNCTION OF VOLTAGE-GATED CALCIUM CHANNELS IN PHEOCHROMOCYTOMA CELLS.

EPA Science Inventory

The industrial solvent perchloroethylene (PERC) is listed as a hazardous air pollutant in the 1990 Ammendments to Clean Air Act and is a known neurotoxicant. However, the mechanisms by which PERC alters nervous system function are poorly understood. In recent years, it has been d...

Genetics Home Reference: early-onset primary dystonia

MedlinePlus

... such as seizures or a loss of intellectual function (dementia). Early-onset primary dystonia does not affect a person's intelligence. On ... of torsinA. The altered protein's effect on the function of nerve cells in the brain ... with early-onset primary dystonia do not have a loss of nerve ...

Molecular mechanisms of gravity-dependent signaling in human melanocytic cells involve cyclic GMP

NASA Astrophysics Data System (ADS)

Ivanova, Krassimira; Lambers, Britta; Block, Ingrid; Bromeis, Birgit; Das, Pranab K.; Gerzer, Rupert

2005-08-01

Gravity alteration (micro- and hypergravity) is known to influence cell functions. As guanosine 3',5'-cyclic monophosphate (cGMP) is an important messenger in melanocyte signaling we have compared the regulation of cGMP levels in human melanocytes and melanoma cells with different metastatic potential under hypergravity conditions. We were able to demonstrate that long-term exposure to hypergravity stimulates cGMP efflux in cultured human melanocytes and non- metastatic melanoma cells, whereas highly metastatic melanoma cells appear to be insensitive to hypergravity, most probably, due to an up-regulated cGMP efflux at 1g. Here we report that these effects are associated with the expression of the multidrug resistance proteins 4 and 5 known to act as selective export pumps for amphiphilic anions like cGMP. Thus, an altered gravity vector may induce cGMP-dependent signaling events in melanocytic cells that could be important for malignant transformation.

The role of metabolic enzymes in mesenchymal tumors and tumor syndromes: genetics, pathology, and molecular mechanisms.

PubMed

Schaefer, Inga-Marie; Hornick, Jason L; Bovée, Judith V M G

2018-04-01

The discovery of mutations in genes encoding the metabolic enzymes isocitrate dehydrogenase (IDH), succinate dehydrogenase (SDH), and fumarate hydratase (FH) has expanded our understanding not only of altered metabolic pathways but also epigenetic dysregulation in cancer. IDH1/2 mutations occur in enchondromas and chondrosarcomas in patients with the non-hereditary enchondromatosis syndromes Ollier disease and Maffucci syndrome and in sporadic tumors. IDH1/2 mutations result in excess production of the oncometabolite (D)-2-hydroxyglutarate. In contrast, SDH and FH act as tumor suppressors and genomic inactivation results in succinate and fumarate accumulation, respectively. SDH deficiency may result from germline SDHA, SDHB, SDHC, or SDHD mutations and is found in autosomal-dominant familial paraganglioma/pheochromocytoma and Carney-Stratakis syndrome, describing the combination of paraganglioma and gastrointestinal stromal tumor (GIST). In contrast, patients with the non-hereditary Carney triad, including paraganglioma, GIST, and pulmonary chondroma, usually lack germline SDH mutations and instead show epigenetic SDH complex inactivation through SDHC promoter methylation. Inactivating FH germline mutations are found in patients with hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome comprising benign cutaneous/uterine leiomyomas and renal cell carcinoma. Mutant IDH, SDH, and FH share common inhibition of α-ketoglutarate-dependent oxygenases such as the TET family of 5-methylcytosine hydroxylases preventing DNA demethylation, and Jumonji domain histone demethylases increasing histone methylation, which together inhibit cell differentiation. Ongoing studies aim to better characterize these complex alterations in cancer, the different clinical phenotypes, and variable penetrance of inherited and sporadic cancer predisposition syndromes. A better understanding of the roles of metabolic enzymes in cancer may foster the development of therapies that specifically target functional alterations in tumor cells in the future. Here, the physiologic functions of these metabolic enzymes, the mutational spectrum, and associated functional alterations will be discussed, with a focus on mesenchymal tumor predisposition syndromes.

Differential progression of structural and functional alterations in distinct retinal ganglion cell types in a mouse model of glaucoma.

PubMed

Della Santina, Luca; Inman, Denise M; Lupien, Caroline B; Horner, Philip J; Wong, Rachel O L

2013-10-30

Intraocular pressure (IOP) elevation is a principal risk factor for glaucoma. Using a microbead injection technique to chronically raise IOP for 15 or 30 d in mice, we identified the early changes in visual response properties of different types of retinal ganglion cells (RGCs) and correlated these changes with neuronal morphology before cell death. Microbead-injected eyes showed reduced optokinetic tracking as well as cell death. In such eyes, multielectrode array recordings revealed that four RGC types show diverse alterations in their light responses upon IOP elevation. OFF-transient RGCs exhibited a more rapid decline in both structural and functional organizations compared with other RGCs. In contrast, although the light-evoked responses of OFF-sustained RGCs were perturbed, the dendritic arbor of this cell type remained intact. ON-transient and ON-sustained RGCs had normal functional receptive field sizes but their spontaneous and light-evoked firing rates were reduced. ON- and OFF-sustained RGCs lost excitatory synapses across an otherwise structurally normal dendritic arbor. Together, our observations indicate that there are changes in spontaneous activity and light-evoked responses in RGCs before detectable dendritic loss. However, when dendrites retract, we found corresponding changes in receptive field center size. Importantly, the effects of IOP elevation are not uniformly manifested in the structure and function of diverse RGC populations, nor are distinct RGC types perturbed within the same time-frame by such a challenge.

Androgens Exert a Cysticidal Effect upon Taenia crassiceps by Disrupting Flame Cell Morphology and Function

PubMed Central

Ambrosio, Javier R.; Valverde-Islas, Laura; Nava-Castro, Karen E.; Palacios- Arreola, M. Isabel; Ostoa-Saloma, Pedro; Reynoso-Ducoing, Olivia; Escobedo, Galileo; Ruíz-Rosado, Azucena; Dominguez-Ramírez, Lenin; Morales-Montor, Jorge

2015-01-01

The effects of testosterone (T4) and dihydrotestosterone (DHT) on the survival of the helminth cestode parasite Taenia crassiceps, as well as their effects on actin, tubulin and myosin expression and their assembly into the excretory system of flame cells are described in this paper. In vitro evaluations on parasite viability, flow cytometry, confocal microscopy, video-microscopy of live flame cells, and docking experiments of androgens interacting with actin, tubulin, and myosin were conducted. Our results show that T4 and DHT reduce T. crassiceps viability in a dose- and time-dependent fashion, reaching 90% of mortality at the highest dose used (40 ng/ml) and time exposed (10 days) in culture. Androgen treatment does not induce differences in the specific expression pattern of actin, tubulin, and myosin isoforms as compared with control parasites. Confocal microscopy demonstrated a strong disruption of the parasite tegument, with reduced assembly, shape, and motion of flame cells. Docking experiments show that androgens are capable of affecting parasite survival and flame cell morphology by directly interacting with actin, tubulin and myosin without altering their protein expression pattern. We show that both T4 and DHT are able to bind actin, tubulin, and myosin affecting their assembly and causing parasite intoxication due to impairment of flame cell function. Live flame cell video microscopy showing a reduced motion as well changes in the shape of flame cells are also shown. In summary, T4 and DHT directly act on T. crassiceps cysticerci through altering parasite survival as well as the assembly and function of flame cells. PMID:26076446

B-Cell Activation and Tolerance Mediated by B-Cell Receptor, Toll-Like Receptor and Survival Signal Crosstalk in SLE Pathogenesis

DTIC Science & Technology

2015-10-01

reduction in the number of regulatory T cells (Tregs) in STING2/2 lpr/lpr secondary lymphoid organs. Apoptotic debris induces the production of IDO...DNA complex is the exclusive malaria parasite component that activates dendritic cells and triggers innate immune responses. J. Immunol. 184: 4338–4348... cells remain relatively unchanged. Nevertheless, nearly all peripheral lymphoid pools exhibit altered dynamics, shifts in functional subset representation

Reduced Expression of Siglec-7, NKG2A, and CD57 on Terminally Differentiated CD56-CD16+ Natural Killer Cell Subset Is Associated with Natural Killer Cell Dysfunction in Chronic HIV-1 Clade C Infection.

PubMed

Zulu, Michael Z; Naidoo, Kewreshini K; Mncube, Zenele; Jaggernath, Manjeetha; Goulder, Philip J R; Ndung'u, Thumbi; Altfeld, Marcus; Thobakgale, Christina F

2017-12-01

HIV-1 viremia has been shown to induce several phenotypic and functional abnormalities in natural killer (NK) cells. To assess immune defects associated with HIV viremia, we examined NK cell function, differentiation status, and phenotypic alterations based on expression of inhibitory and activating receptors on NK cells in HIV-1 subtype C chronically infected participants from Durban, South Africa. NK cell phenotypic profiles were characterized by assessing sialic acid-binding immunoglobulin-like lectin-7 (Siglec-7), NKG2A, and NKG2C markers on frozen peripheral blood mononuclear cells from viremic, antiretroviral therapy (ART)-naive HIV-1 chronically infected participants (n = 23), HIV-1 chronically infected participants who had been on combination antiretroviral therapy (cART) for at least 12 months (n = 23) compared with healthy donors (n = 23). NK cell differentiation was assessed by measurement of killer immunoglobulin receptor (KIR) and NKG2A expression; CD57 and CD107a measurements were carried out in HIV viremic and healthy donors. All phenotypic and functional assessments were analyzed by using multicolor flow cytometry. HIV-1-infected participants displayed greater frequencies of the CD56 - CD16 + (CD56negative) NK cell subset compared with healthy donors (p < .0001). Downregulation of Siglec-7 and NKG2A and upregulation of NKG2C were more pronounced in the CD56negative NK cell subset of viremic participants. The CD56negative subset demonstrated a differentiated (KIR + NKG2A - ) phenotype with reduced CD57 expression and lower degranulation capacity in HIV-1-infected participants compared with healthy donors. HIV-1 infection induces the expansion of the CD56negative NK cell subset marked by altered receptor expression profiles that are indicative of impaired function and may explain the overall NK cell dysfunction observed in chronic HIV-1 infection.

Activation of p44/42 in Human Natural Killer Cells Decreases Cell-surface Protein Expression: Relationship to Tributyltin-induced alterations of protein expression

PubMed Central

Dudimah, Fred D.; Abraha, Abraham; Wang, Xiaofei; Whalen, Margaret M.

2010-01-01

Tributyltin (TBT) activates the mitogen activated protein kinase (MAPK), p44/42 in human natural killer (NK) cells. TBT also reduces NK cytotoxic function and decreases the expression of several NK-cell proteins. To understand the role that p44/42 activation plays in TBT-induced loss of NK cell function, we have investigated how selective activation of p44/42 by phorbol 12-myristate 13-acetate (PMA) affects NK cells. Previously we showed that PMA caused losses of lytic function similar to those seen with TBT exposures. Here we examined activation of p44/42 in the regulation of NK-cell protein expression and how this regulation may explain the protein expression changes seen with TBT exposures. NK cells exposed to PMA were examined for levels of cell-surface proteins, granzyme mRNA, and perforin mRNA expression. The expression of CD11a, CD16, CD18, and CD56 were reduced, perforin mRNA levels were unchanged and granzyme mRNA levels were increased. To verify that activation of p44/42 was responsible for the alterations seen in CD11a, CD16, CD18, and CD56 with PMA, NK cells were treated with the p44/42 pathway inhibitor (PD98059) prior to PMA exposures. In the presence of PD98059, PMA caused no decreases in the expression of the cell-surface proteins. Results of these studies indicate that the activation of p44/42 may lead to the loss of NK cell cytotoxic function by decreasing the expression of CD11a, CD16, CD18, and CD56. Further, activation of p44/42 appears to be at least in part responsible for the TBT-induced decreases in expression of CD16, CD18, and CD56. PMID:20883105

Cancer cell metabolism and the modulating effects of nitric oxide.

PubMed

Chang, Ching-Fang; Diers, Anne R; Hogg, Neil

2015-02-01

Altered metabolic phenotype has been recognized as a hallmark of tumor cells for many years, but this aspect of the cancer phenotype has come into greater focus in recent years. NOS2 (inducible nitric oxide synthase of iNOS) has been implicated as a component in many aggressive tumor phenotypes, including melanoma, glioblastoma, and breast cancer. Nitric oxide has been well established as a modulator of cellular bioenergetics pathways, in many ways similar to the alteration of cellular metabolism observed in aggressive tumors. In this review we attempt to bring these concepts together with the general hypothesis that one function of NOS2 and NO in cancer is to modulate metabolic processes to facilitate increased tumor aggression. There are many mechanisms by which NO can modulate tumor metabolism, including direct inhibition of respiration, alterations in mitochondrial mass, oxidative inhibition of bioenergetic enzymes, and the stimulation of secondary signaling pathways. Here we review metabolic alterations in the context of cancer cells and discuss the role of NO as a potential mediator of these changes. Copyright © 2015. Published by Elsevier Inc.

Session 2: Personalised nutrition. Epigenomics: a basis for understanding individual differences?

PubMed

Mathers, John C

2008-11-01

Epigenetics encompasses changes to marks on the genome that are copied from one cell generation to the next, which may alter gene expression but which do not involve changes in the primary DNA sequence. These marks include DNA methylation (methylation of cytosines within CpG dinucleotides) and post-translational modifications (acetylation, methylation, phosphorylation and ubiquitination) of the histone tails protruding from nucleosome cores. The sum of genome-wide epigenetic patterns is known as the epigenome. It is hypothesised that altered epigenetic marking is a means through which evidence of environmental exposures (including nutritional status and dietary exposure) is received and recorded by the genome. At least some of these epigenetic marks are remembered through multiple cell generations and their effects may be revealed in altered gene expression and cell function. Altered epigenetic marking allows plasticity of phenotype in a fixed genotype. Despite their identical genotypes, monozygotic twins show increasing epigenetic diversity with age and with divergent lifestyles. Differences in epigenetic markings may explain some inter-individual variation in disease risk and in response to nutritional interventions.

Cancer Cell Metabolism and the Modulating Effects of Nitric Oxide

PubMed Central

Chang, Ching-Fang; Diers, Anne R.; Hogg, Neil

2016-01-01

Altered metabolic phenotype has been recognized as a hallmark of tumor cells for many years, but this aspect of the cancer phenotype has come into greater focus in recent years. NOS2 (inducible nitric oxide synthase of iNOS) has been implicated as a component in many aggressive tumor phenotypes, including melanoma, glioblastoma and breast cancer. Nitric oxide has been well established as a modulator of cellular bioenergetics pathways, in many ways similar to the alteration of cellular metabolism observed in aggressive tumors. In this review we attempt to bring these concepts together with the general hypothesis that one function of NOS2 and NO in cancer is to modulate metabolic processes to facilitate increased tumor aggression. There are many mechanisms by which NO can modulate tumor metabolism, including direct inhibition of respiration, alterations in mitochondrial mass, oxidative inhibition of bioenergetic enzymes, and the stimulation of secondary signaling pathways. Here we review metabolic alterations in the context of cancer cells and discuss the role of NO as a potential mediator of these changes. PMID:25464273

Tumourigenicity and radiation resistance of mesenchymal stem cells.

PubMed

D'Andrea, Filippo P; Horsman, Michael R; Kassem, Moustapha; Overgaard, Jens; Safwat, Akmal

2012-05-01

Cancer stem cells are believed to be more radiation resistant than differentiated tumour cells of the same origin. It is not known, however, whether normal nontransformed adult stem cells share the same radioresistance as their cancerous counterpart. Nontumourigenic (TERT4) and tumourigenic (TRET20) cell lines, from an immortalised mesenchymal stem cell line, were grown in culture prior to irradiation and gene expression analysis. Radiation resistance was measured using a clonogenic assay. Differences in gene expression between the two cell lines, both under nontreated and irradiated conditions, were assessed with microarrays (Affymetrix Human Exon 1.0 ST array). The cellular functions affected by the altered gene expressions were assessed through gene pathway mapping (Ingenuity Pathway Analysis). Based on the clonogenic assay the nontumourigenic cell line was found to be more sensitive to radiation than the tumourigenic cell line. Using the exon chips, 297 genes were found altered between untreated samples of the cell lines whereas only 16 genes responded to radiation treatment. Among the genes with altered expression between the untreated samples were PLAU, PLAUR, TIMP3, MMP1 and LOX. The pathway analysis based on the alteration between the untreated samples indicated cancer and connective tissue disorders. This study has shown possible common genetic events linking tumourigenicity and radiation response. The PLAU and PLAUR genes are involved in apoptosis evasion while the genes TIMP3, MMP1 and LOX are involved in regulation of the surrounding matrix. The first group may contribute to the difference in radiation resistance observed and the latter could be a major contributor to the tumourigenic capabilities by degrading the intercellular matrix. These results also indicate that cancer stem cells are more radiation resistant than stem cells of the same origin.

Surfactant Functionalization Induces Robust, Differential Adhesion of Tumor Cells and Blood Cells to Charged Nanotube-Coated Biomaterials Under Flow

PubMed Central

Mitchell, Michael J.; Castellanos, Carlos A.; King, Michael R.

2015-01-01

The metastatic spread of cancer cells from the primary tumor to distant sites leads to a poor prognosis in cancers originating from multiple organs. Increasing evidence has linked selectin-based adhesion between circulating tumor cells (CTCs) and endothelial cells of the microvasculature to metastatic dissemination, in a manner similar to leukocyte adhesion during inflammation. Functionalized biomaterial surfaces hold promise as a diagnostic tool to separate CTCs and potentially treat metastasis, utilizing antibody and selectin-mediated interactions for cell capture under flow. However, capture at high purity levels is challenged by the fact that CTCs and leukocytes both possess selectin ligands. Here, a straightforward technique to functionalize and alter the charge of naturally occurring halloysite nanotubes using surfactants is reported to induce robust, differential adhesion of tumor cells and blood cells to nanotube-coated surfaces under flow. Negatively charged sodium dodecanoate-functionalized nanotubes simultaneously enhanced tumor cell capture while negating leukocyte adhesion, both in the presence and absence of adhesion proteins, and can be utilized to isolate circulating tumor cells regardless of biomarker expression. Conversely, diminishing nanotube charge via functionalization with decyltrimethylammonium bromide both abolished tumor cell capture while promoting leukocyte adhesion. PMID:25934290

Altered Lipid Homeostasis in Sertoli Cells Stressed by Mild Hyperthermia

PubMed Central

Vallés, Ana S.; Aveldaño, Marta I.; Furland, Natalia E.

2014-01-01

Spermatogenesis is known to be vulnerable to temperature. Exposures of rat testis to moderate hyperthermia result in loss of germ cells with survival of Sertoli cells (SC). Because SC provide structural and metabolic support to germ cells, our aim was to test the hypothesis that these exposures affect SC functions, thus contributing to germ cell damage. In vivo, regularly repeated exposures (one of 15 min per day, once a day during 5 days) of rat testes to 43°C led to accumulation of neutral lipids. This SC-specific lipid function took 1–2 weeks after the last of these exposures to be maximal. In cultured SC, similar daily exposures for 15 min to 43°C resulted in significant increase in triacylglycerol levels and accumulation of lipid droplets. After incubations with [3H]arachidonate, the labeling of cardiolipin decreased more than that of other lipid classes. Another specifically mitochondrial lipid metabolic function, fatty acid oxidation, also declined. These lipid changes suggested that temperature affects SC mitochondrial physiology, which was confirmed by significantly increased degrees of membrane depolarization and ROS production. This concurred with reduced expression of two SC-specific proteins, transferrin, and Wilms' Tumor 1 protein, markers of SC secretion and differentiation functions, respectively, and with an intense SC cytoskeletal perturbation, evident by loss of microtubule network (α-tubulin) and microfilament (f-actin) organization. Albeit temporary and potentially reversible, hyperthermia-induced SC structural and metabolic alterations may be long-lasting and/or extensive enough to respond for the decreased survival of the germ cells they normally foster. PMID:24690895

HIV Infection in Uncircumcised Men Is Associated With Altered CD8 T-cell Function But Normal CD4 T-cell Numbers in the Foreskin.

PubMed

Prodger, Jessica L; Hirbod, Taha; Gray, Ronald; Kigozi, Godfrey; Nalugoda, Fred; Galiwango, Ronald; Reynolds, Steven J; Huibner, Sanja; Wawer, Maria J; Serwadda, David; Kaul, Rupert

2014-04-15

Human immunodeficiency virus (HIV)-infected (HIV+) men are more susceptible to sexually transmitted infections, and may be superinfected by HIV. We hypothesized that HIV induces immune alterations in the foreskin that may impact the subsequent acquisition/clearance of genital coinfections. Foreskin tissue and blood were obtained from 70 HIV-uninfected and 20 HIV+ men undergoing circumcision. T cells were characterized by flow cytometry, immunohistochemistry, and polymerase chain reaction. There was substantial influx of CD8 T-cells into the foreskins of HIV+ men (108.8 vs 23.1 cells/mm(2); P < .001); but foreskin CD4 T-cell density was unchanged (43.0 vs 33.7/mm(2); P = .67), despite substantial blood depletion (409.0 vs 877.8 cells/µL; P < .001). While frequencies of foreskin C-C chemokine receptor type 5(+) (CCR5(+)) T cells, T regulatory cells, and T-helper 17 cells were unaltered in HIV+ men, CD8 T-cell production of tumor necrosis factor α (TNFα) was decreased. HIV-specific CD8 T cells were present in the foreskins of HIV+ men, although their frequency and function was reduced compared to the blood. Foreskin CD4 T-cell density and CCR5 expression were not reduced during HIV infection, perhaps explaining susceptibility to HIV superinfection. Foreskin CD8 T-cell density was increased, but decreased production of TNFα may enhance susceptibility to genital coinfections in HIV+ men.

Adipose tissue transcriptomic signature highlights the pathological relevance of extracellular matrix in human obesity

PubMed Central

Henegar, Corneliu; Tordjman, Joan; Achard, Vincent; Lacasa, Danièle; Cremer, Isabelle; Guerre-Millo, Michèle; Poitou, Christine; Basdevant, Arnaud; Stich, Vladimir; Viguerie, Nathalie; Langin, Dominique; Bedossa, Pierre; Zucker, Jean-Daniel; Clement, Karine

2008-01-01

Background Investigations performed in mice and humans have acknowledged obesity as a low-grade inflammatory disease. Several molecular mechanisms have been convincingly shown to be involved in activating inflammatory processes and altering cell composition in white adipose tissue (WAT). However, the overall importance of these alterations, and their long-term impact on the metabolic functions of the WAT and on its morphology, remain unclear. Results Here, we analyzed the transcriptomic signature of the subcutaneous WAT in obese human subjects, in stable weight conditions and after weight loss following bariatric surgery. An original integrative functional genomics approach was applied to quantify relations between relevant structural and functional themes annotating differentially expressed genes in order to construct a comprehensive map of transcriptional interactions defining the obese WAT. These analyses highlighted a significant up-regulation of genes and biological themes related to extracellular matrix (ECM) constituents, including members of the integrin family, and suggested that these elements could play a major mediating role in a chain of interactions that connect local inflammatory phenomena to the alteration of WAT metabolic functions in obese subjects. Tissue and cellular investigations, driven by the analysis of transcriptional interactions, revealed an increased amount of interstitial fibrosis in obese WAT, associated with an infiltration of different types of inflammatory cells, and suggest that phenotypic alterations of human pre-adipocytes, induced by a pro-inflammatory environment, may lead to an excessive synthesis of ECM components. Conclusion This study opens new perspectives in understanding the biology of human WAT and its pathologic changes indicative of tissue deterioration associated with the development of obesity. PMID:18208606

Effects of lead intoxication on intercellular junctions and biochemical alterations of the renal proximal tubule cells.

PubMed

Navarro-Moreno, L G; Quintanar-Escorza, M A; González, S; Mondragón, R; Cerbón-Solorzáno, J; Valdés, J; Calderón-Salinas, J V

2009-10-01

Lead intoxication is a worldwide health problem which frequently affects the kidney. In this work, we studied the effects of chronic lead intoxication (500 ppm of Pb in drinking water during seven months) on the structure, function and biochemical properties of rat proximal tubule cells. Lead-exposed animals showed increased lead concentration in kidney, reduction of calcium and amino acids uptake, oxidative damage and glucosuria, proteinuria, hematuria and reduced urinary pH. These biochemical and physiological alterations were related to striking morphological modifications in the structure of tubule epithelial cells and in the morphology of their mitochondria, nuclei, lysosomes, basal and apical membranes. Interestingly, in addition to the nuclei, inclusion bodies were found in the cytoplasm and in mitochondria. The epithelial cell structure modifications included an early loss of the apical microvillae, followed by a decrement of the luminal space and the respective apposition and proximity of apical membranes, resulting in the formation of atypical intercellular contacts and adhesion structures. Similar but less marked alterations were observed in subacute lead intoxication as well. Our work contributes in the understanding of the physiopathology of lead intoxication on the structure of renal tubular epithelial cell-cell contacts in vivo.

Cellular Basis of Mechanotransduction

NASA Technical Reports Server (NTRS)

Ingber, Donald E.

1996-01-01

Physical forces, such as those due to gravity are fundamental regulators of tissue development. To influence morphogenesis, mechanical forces must alter growth and function. Yet little is known about how cells convert mechanical signals into a chemical response. This presentation attempts to place the potential molecular mediators of mechanotransduction within the context of the structural complexity of living cells.

TLR agonists are highly effective at eliciting functional memory CTLs of effector memory phenotype in peptide immunization

USDA-ARS?s Scientific Manuscript database

Given the importance of memory cytotoxic T lymphocytes (CTLs) in eliminating altered self-cells, including virus-infected and tumor cells, devising effective vaccination strategies for generating memory CTLs is a priority in the field of immunology. Herein, we elaborate upon a novel boosting approac...

Current immunotherapeutic strategies in pancreatic cancer.

PubMed

Plate, Janet M D

2007-10-01

The immune systems of patients with newly diagnosed pancreatic cancers are functional, with T-cell responses capable of responding to tumor antigen presentation. Pancreatic tumors have been demonstrated to express tumor antigens as mutated, altered, underglycosylated and/or inappropriately overexpressed proteins. Considering these two facts, it should be possible for patients' bodies to recognize their tumors as foreign and to reject them. A number of clinical trials have been initiated to exploit this immune activation to eradicate or stabilize tumor growth. Immunotherapeutic trials include the specific testing of a variety of tumor vaccines, of cytokines as adjuvants or directed cytotoxicity, and of monoclonal antibodies to target specific molecules. This article reviews evidence for immune-cell activation and function in patients with pancreatic cancer, and evidence that pancreatic tumor cells express tumor antigens, or mutated (or altered) proteins. Nevertheless, tumors survive immune attacks by producing products that help them to circumvent effector T cells. The article thus examines complications of immune evasion by cancer cells, as well as the challenges of trying to exploit the immune system in solid tumors where tumor cell products can turn off invading immune T cells set to kill them. Finally, the article discusses the choices of a variety of clinical trials using immune modulation for patients with pancreatic cancer.

Early effects of altered gravity environments on plant cell growth and cell proliferation: Characterization of morphofunctional nucleolar types in an Arabidopsis cell culture system

NASA Astrophysics Data System (ADS)

Manzano, Ana Isabel; Herranz, Raul; Manzano, Aránzazu; Van Loon, Jack; Medina, Francisco Javier

2016-02-01

Changes in the cell growth rate of an in vitro cellular system in Arabidopsis thaliana induced by short exposure to an altered gravity environment have been estimated by a novel approach. The method consisted of defining three structural nucleolar types which are easy and reliable indicators of the ribosome biogenesis activity and, consequently, of protein biosynthesis, a parameter strictly correlated to cell growth in this cellular system. The relative abundance of each nucleolar type was statistically assessed in different conditions of gravity. Samples exposed to simulated microgravity for 200 min showed a significant decrease in nucleolar activity compared to 1g controls, whereas samples exposed to hypergravity (2g) for the same period showed nucleolar activity slightly increased,. These effects could be considered as an early cellular response to the environmental alteration, given the short duration of the treatment. The functional significance of the structural data was validated by a combination of several different well-known parameters, using microscopical, flow cytometry, qPCR and proteomic approaches, which showed that the decreased cell growth rate was decoupled from an increased cell proliferation rate under simulated microgravity, and the opposite trend was observed under hypergravity. Actually, not all parameters tested showed the same quantitative changes, indicating that the response to the environmental alteration is time-dependent. These results are in agreement with previous observations in root meristematic cells and they show the ability of plant cells to produce a response to gravity changes, independently of their integration into plant organs.

Metabolism alteration in follicular niche: The nexus among intermediary metabolism, mitochondrial function, and classic polycystic ovary syndrome.

PubMed

Zhao, Hongcui; Zhao, Yue; Li, Tianjie; Li, Min; Li, Junsheng; Li, Rong; Liu, Ping; Yu, Yang; Qiao, Jie

2015-09-01

Classic polycystic ovary syndrome (PCOS) is a high-risk phenotype accompanied by increased risks of reproductive and metabolic abnormalities; however, the local metabolism characteristics of the ovaries and their effects on germ cell development are unclear. The present study used targeted metabolomics to detect alterations in the intermediate metabolites of follicular fluid from classic PCOS patients, and the results indicated that hyperandrogenism but not obesity induced the changed intermediate metabolites in classic PCOS patients. Regarding the direct contact, we identified mitochondrial function, redox potential, and oxidative stress in cumulus cells which were necessary to support oocyte growth before fertilization, and suggested dysfunction of mitochondria, imbalanced redox potential, and increased oxidative stress in cumulus cells of classic PCOS patients. Follicular fluid intermediary metabolic profiles provide signatures of classic PCOS ovary local metabolism and establish a close link with mitochondria dysfunction of cumulus cells, highlighting the role of metabolic signal and mitochondrial cross talk involved in the pathogenesis of classic PCOS. Copyright © 2015 Elsevier Inc. All rights reserved.

Lactobacillus johnsonii supplementation attenuates respiratory viral infection via metabolic reprogramming and immune cell modulation.

PubMed

Fonseca, W; Lucey, K; Jang, S; Fujimura, K E; Rasky, A; Ting, H-A; Petersen, J; Johnson, C C; Boushey, H A; Zoratti, E; Ownby, D R; Levine, A M; Bobbit, K R; Lynch, S V; Lukacs, N W

2017-11-01

Regulation of respiratory mucosal immunity by microbial-derived metabolites has been a proposed mechanism that may provide airway protection. Here we examine the effect of oral Lactobacillus johnsonii supplementation on metabolic and immune response dynamics during respiratory syncytial virus (RSV) infection. L. johnsonii supplementation reduced airway T helper type 2 cytokines and dendritic cell (DC) function, increased regulatory T cells, and was associated with a reprogrammed circulating metabolic environment, including docosahexanoic acid (DHA) enrichment. RSV-infected bone marrow-derived DCs (BMDCs) from L. johnsonii-supplemented mice had altered cytokine secretion, reduced expression of co-stimulatory molecules, and modified CD4+ T-cell cytokines. This was replicated upon co-incubation of wild-type BMDCs with either plasma from L. johnsonii-supplemented mice or DHA. Finally, airway transfer of BMDCs from L. johnsonii-supplemented mice or with wild-type derived BMDCs pretreated with plasma from L. johnsonii-supplemented mice reduced airway pathological responses to infection in recipient animals. Thus L. johnsonii supplementation mediates airway mucosal protection via immunomodulatory metabolites and altered immune function.

Senescence-Induced Alterations of Laminin Chain Expression Modulate Tumorigenicity of Prostate Cancer Cells1

PubMed Central

Sprenger, Cynthia C T; Drivdahl, Rolf H; Woodke, Lillie B; Eyman, Daniel; Reed, May J; Carter, William G; Plymate, Stephen R

2008-01-01

Prostate cancer is an age-associated epithelial cancer, and as such, it contributes significantly to the mortality of the elderly. Senescence is one possible mechanism by which the body defends itself against various epithelial cancers. Senescent cells alter the microenvironment, in part, through changes to the extracellular matrix. Laminins (LMs) are extracellular proteins important to both the structure and function of the microenvironment. Overexpression of the senescence-associated gene mac25 in human prostate cancer cells resulted in increased mRNA levels of the LM α4 and β2 chains compared to empty vector control cells. The purpose of this study was to examine the effects of these senescence-induced LM chains on tumorigenicity of prostate cancer cells. We created stable M12 human prostate cancer lines overexpressing either the LM α4 or β2 chain or both chains. Increased expression of either the LM α4 or β2 chain resulted in increased in vitro migration and in vivo tumorigenicity of those cells, whereas high expression of both chains led to decreased in vitro proliferation and in vivo tumorigenicity compared to M12 control cells. This study demonstrates that senescent prostate epithelial cells can alter the microenvironment and that these changes modulate progression of prostate cancer. PMID:19048114

Gene expression profiling in multipotent DFAT cells derived from mature adipocytes

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

Ono, Hiromasa; Database Center for Life Science; Oki, Yoshinao

2011-04-15

Highlights: {yields} Adipocyte dedifferentiation is evident in a significant decrease in typical genes. {yields} Cell proliferation is strongly related to adipocyte dedifferentiation. {yields} Dedifferentiated adipocytes express several lineage-specific genes. {yields} Comparative analyses using publicly available datasets boost the interpretation. -- Abstract: Cellular dedifferentiation signifies the withdrawal of cells from a specific differentiated state to a stem cell-like undifferentiated state. However, the mechanism of dedifferentiation remains obscure. Here we performed comparative transcriptome analyses during dedifferentiation in mature adipocytes (MAs) to identify the transcriptional signatures of multipotent dedifferentiated fat (DFAT) cells derived from MAs. Using microarray systems, we explored similarly expressed asmore » well as significantly differentially expressed genes in MAs during dedifferentiation. This analysis revealed significant changes in gene expression during this process, including a significant reduction in expression of genes for lipid metabolism concomitantly with a significant increase in expression of genes for cell movement, cell migration, tissue developmental processes, cell growth, cell proliferation, cell morphogenesis, altered cell shape, and cell differentiation. Our observations indicate that the transcriptional signatures of DFAT cells derived from MAs are summarized in terms of a significant decrease in functional phenotype-related genes and a parallel increase in cell proliferation, altered cell morphology, and regulation of the differentiation of related genes. A better understanding of the mechanisms involved in dedifferentiation may enable scientists to control and possibly alter the plasticity of the differentiated state, which may lead to benefits not only in stem cell research but also in regenerative medicine.« less

[Endoplasmic-mitochondrial Ca(2+)-functional unit: dependence of respiration of secretory cells on activity of ryanodine- and IP3 - sensitive Ca(2+)-channels].

PubMed

Velykopols'ka, O Iu; Man'ko, B O; Man'ko, V V

2012-01-01

Using Clark oxygen electrode, dependence of mitochondrial functions on Ca(2+)-release channels activity of Chironomus plumosus L. larvae salivary glands suspension was investigated. Cells were ATP-permeabilized in order to enable penetration of exogenous oxidative substrates. Activation of plasmalemmal P2X-receptors (as well as P2Y-receptors) per se does not modify the endogenous respiration of salivary gland suspension. That is, Ca(2+)-influx from extracellular medium does not influence functional activity of mitochondria, although they are located along the basal part of the plasma membrane. Activation of RyRs intensifies endogenous respiration and pyruvate-malate-stimulated respiration, but not succinate-stimulated respiration. Neither activation of IP3Rs (via P2Y-receptors activation), nor their inhibition alters endogenous respiration. Nevertheless, IP3Rs inhibition by 2-APB intensifies succinate-stimulated respiration. All abovementioned facts testify that Ca2+, released from stores via channels, alters functional activity of mitochondria, and undoubtedly confirm the existence of endoplasmic-mitochondrial Ca(2+)-functional unit in Ch. plumosus larvae salivary glands secretory cells. In steady state of endoplasmic-mitochondrial Ca(2+)-functional unit the spontaneous activity of IP3Rs is observed; released through IP3Rs, Ca2+ is accumulated in mitochondria via uniporter and modulates oxidative processes. Activation of RyRs induces the transition of endoplasmic-mitochondrial Ca(2+)-functional unit to the active state, which is required to intensify cell respiration and oxidative phosphorylation. As expected, the transition of endoplasmic-mitochondrial Ca(2+)-functional unit to inactivated state (i. e. inhibition of Ca(2+)-release channels at excessive [Ca2+]i) limits the duration of signal transduction, has protective nature and prevents apoptosis.

Effects of acute altered gravity during parabolic flight and/or vestibular loss on cell proliferation in the rat dentate gyrus.

PubMed

Zheng, Yiwen; Gliddon, Catherine M; Aitken, Phillip; Stiles, Lucy; Machado, Marie-Laure; Philoxene, Bruno; Denise, Pierre; Smith, Paul F; Besnard, Stephane

2017-07-27

Both parabolic flight, i.e. a condition of altered gravity, and loss of vestibular function, have been suggested to affect spatial learning and memory, which is known to be influenced by neurogenesis in the hippocampus. In this study we investigated whether short alternated micro- and hyper-gravity stimulations during parabolic flight and/or loss of vestibular function, would alter cell proliferation in the hippocampal dentate gyrus of rats, by measuring the number of bromodeoxyuridine (BrdU)-incorporated cells. Rats were randomly allocated to the following experimental groups: (1) sham transtympanic saline injection only (n=5); (2) bilateral vestibular deafferentation (BVD) by sodium arsanilate transtympanic injection only (n=5); (3) sham treatment and parabolic flight (n=5); (4) BVD and parabolic flight (n=6). Forty-two days following transtympanic injection, the animals were subjected to parabolic flight in an awake restrained condition after habituation. A modified Airbus A300 aircraft was flown on a parabolic path, creating 20s of 1.8G during both climbing and descending and 22s of 0G at the apex of each parabola. The no flight animals were subjected to the same housing for the same duration. Immediately after the parabolic flight or control ground condition, animals were injected with BrdU (300mg/kg, i.p). Twenty-four hs after BrdU injection, rats were sacrificed. BrdU immunolabelling was performed and the number of BrdU +ve cells in the dentate gyrus of the hippocampus was quantified using a modified fractionator method. BVD caused a large and significant reduction in the number of BrdU-positive cells compared to sham animals (P≤0.0001); however, flight and all interactions were non-significant. These results indicate that BVD significantly decreased cell proliferation irrespective of the short exposure to altered/modified gravity. Copyright © 2017 Elsevier B.V. All rights reserved.

Chromatin organization as an indicator of glucocorticoid induced natural killer cell dysfunction.

PubMed

Misale, Michael S; Witek Janusek, Linda; Tell, Dina; Mathews, Herbert L

2018-01-01

It is well-established that psychological distress reduces natural killer cell immune function and that this reduction can be due to the stress-induced release of glucocorticoids. Glucocorticoids are known to alter epigenetic marks associated with immune effector loci, and are also known to influence chromatin organization. The purpose of this investigation was to assess the effect of glucocorticoids on natural killer cell chromatin organization and to determine the relationship of chromatin organization to natural killer cell effector function, e.g. interferon gamma production. Interferon gamma production is the prototypic cytokine produced by natural killer cells and is known to modulate both innate and adaptive immunity. Glucocorticoid treatment of human peripheral blood mononuclear cells resulted in a significant reduction in interferon gamma production. Glucocorticoid treatment also resulted in a demonstrable natural killer cell nuclear phenotype. This phenotype was localization of the histone, post-translational epigenetic mark, H3K27me3, to the nuclear periphery. Peripheral nuclear localization of H3K27me3 was directly related to cellular levels of interferon gamma. This nuclear phenotype was determined by direct visual inspection and by use of an automated, high through-put technology, the Amnis ImageStream. This technology combines the per-cell information content provided by standard microscopy with the statistical significance afforded by large sample sizes common to standard flow cytometry. Most importantly, this technology provides for a direct assessment of the localization of signal intensity within individual cells. The results demonstrate glucocorticoids to dysregulate natural killer cell function at least in part through altered H3K27me3 nuclear organization and demonstrate H3K27me3 chromatin organization to be a predictive indicator of glucocorticoid induced immune dysregulation of natural killer cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Connections between cadherin-catenin proteins, spindle misorientation, and cancer

PubMed Central

Shahbazi, Marta N; Perez-Moreno, Mirna

2015-01-01

Cadherin-catenin mediated adhesion is an important determinant of tissue architecture in multicellular organisms. Cancer progression and maintenance is frequently associated with loss of their expression or functional activity, which not only leads to decreased cell-cell adhesion, but also to enhanced tumor cell proliferation and loss of differentiated characteristics. This review is focused on the emerging implications of cadherin-catenin proteins in the regulation of polarized divisions through their connections with the centrosomes, cytoskeleton, tissue tension and signaling pathways; and illustrates how alterations in cadherin-catenin levels or functional activity may render cells susceptible to transformation through the loss of their proliferation-differentiation balance. PMID:26451345

Membrane Composition Tunes the Outer Hair Cell Motor

NASA Astrophysics Data System (ADS)

Rajagopalan, L.; Sfondouris, J.; Oghalai, J. S.; Pereira, F. A.; Brownell, W. E.

2009-02-01

Cholesterol and docosahexaenoic acid (DHA), an ω-3 fatty acid, affect membrane mechanical properties in different ways and modulate the function of membrane proteins. We have probed the functional consequence of altering cholesterol and DHA levels in the membranes of OHCs and prestin expressing HEK cells. Large, dynamic and reversible changes in prestin-associated charge movement and OHC motor activity result from altering the concentration of membrane cholesterol. Increasing membrane cholesterol shifts the q/V function ~ 50 mV in the hyperpolarizing direction, possibly a response related to increases in membrane stiffness. The voltage shift is linearly related to total membrane cholesterol. Increasing cholesterol also decreases the total charge moved in a linear fashion. Decreasing membrane cholesterol shifts the q/V function ~ 50 mV in the depolarizing direction with little or no effect on the amount of charge moved. In vivo increases in membrane cholesterol transiently increase but ultimately lead to decreases in DPOAE. Docosahexaenoic acid shifts the q/V function in the hyperpolarizing direction < 15 mV and increases total charge moved. Tuning of cochlear function by membrane cholesterol contributes to the exquisite temporal and frequency processing of mammalian hearing by optimizing the cochlear amplifier.

Circular RNAs are long-lived and display only minimal early alterations in response to a growth factor

PubMed Central

Enuka, Yehoshua; Lauriola, Mattia; Feldman, Morris E.; Sas-Chen, Aldema; Ulitsky, Igor; Yarden, Yosef

2016-01-01

Circular RNAs (circRNAs) are widespread circles of non-coding RNAs with largely unknown function. Because stimulation of mammary cells with the epidermal growth factor (EGF) leads to dynamic changes in the abundance of coding and non-coding RNA molecules, and culminates in the acquisition of a robust migratory phenotype, this cellular model might disclose functions of circRNAs. Here we show that circRNAs of EGF-stimulated mammary cells are stably expressed, while mRNAs and microRNAs change within minutes. In general, the circRNAs we detected are relatively long-lived and weakly expressed. Interestingly, they are almost ubiquitously co-expressed with the corresponding linear transcripts, and the respective, shared promoter regions are more active compared to genes producing linear isoforms with no detectable circRNAs. These findings imply that altered abundance of circRNAs, unlike changes in the levels of other RNAs, might not play critical roles in signaling cascades and downstream transcriptional networks that rapidly commit cells to specific outcomes. PMID:26657629

Immune Dysregulation Following Short versus Long Duration Space Flight. Version 03

NASA Technical Reports Server (NTRS)

Crucian, Brian E.; Stowe, Raymond P.; Pierson, Duane L.; Sams, Clarence F.

2007-01-01

Immune system dysregulation has been demonstrated to occur during spaceflight and has the potential to cause serious health risks to crewmembers participating in exploration-class missions. A comprehensive immune assessment was recently performed on 13 short duration Space Shuttle crewmembers and 8 long duration International Space Station (ISS) crewmembers. Statistically significant post-flight phenotype alterations (as compared to pre-flight baseline) for the Shuttle crewmembers included: granulocytosis, increased percentage of B cells, reduced percentage of NK cells, elevated CD4/CD8 ratio, elevated levels of memory CD4+ T cells, and a CD8+ T cell shift to a less differentiated state. For the Shuttle crewmembers, T cell function was surprisingly elevated post-flight, among both the CD4+ and CD8+ subsets. This is likely an acute stress response in less-deconditioned crewmembers. The percentage of CD4+/IL-2+, CD4+/IFNg+ and CD8+/IFNg+ T cells were all decreased at landing. Culture secreted IFNg production was significantly decreased at landing, whereas production of Th2 cytokines was largely unchanged. It was found that the IFNg:IL-10 ratio was obviously declined in the Shuttle crewmembers immediately post-flight. A similar pattern of alterations were observed for the long duration ISS crewmembers. In contrast to Shuttle crewmembers, the ISS crewmembers demonstrated a dramatic reduction in T cell function immediately post-flight. This may be related to the effect of acute landing stress in conjunction with prolonged deconditioning associated with extended flight. The reduction in IFNg:IL-10 ratio (Th2 shift) was also observed post-flight in the ISS crewmembers to a much higher degree. These data indicate consistent peripheral phenotype changes and altered cytokine production profiles occur following space travel of both short and long duration.

High Throughput Screening for Compounds That Alter Muscle Cell Glycosylation Identifies New Role for N-Glycans in Regulating Sarcolemmal Protein Abundance and Laminin Binding*

PubMed Central

Cabrera, Paula V.; Pang, Mabel; Marshall, Jamie L.; Kung, Raymond; Nelson, Stanley F.; Stalnaker, Stephanie H.; Wells, Lance; Crosbie-Watson, Rachelle H.; Baum, Linda G.

2012-01-01

Duchenne muscular dystrophy is an X-linked disorder characterized by loss of dystrophin, a cytoskeletal protein that connects the actin cytoskeleton in skeletal muscle cells to extracellular matrix. Dystrophin binds to the cytoplasmic domain of the transmembrane glycoprotein β-dystroglycan (β-DG), which associates with cell surface α-dystroglycan (α-DG) that binds laminin in the extracellular matrix. β-DG can also associate with utrophin, and this differential association correlates with specific glycosylation changes on α-DG. Genetic modification of α-DG glycosylation can promote utrophin binding and rescue dystrophic phenotypes in mouse dystrophy models. We used high throughput screening with the plant lectin Wisteria floribunda agglutinin (WFA) to identify compounds that altered muscle cell surface glycosylation, with the goal of finding compounds that increase abundance of α-DG and associated sarcolemmal glycoproteins, increase utrophin usage, and increase laminin binding. We identified one compound, lobeline, from the Prestwick library of Food and Drug Administration-approved compounds that fulfilled these criteria, increasing WFA binding to C2C12 cells and to primary muscle cells from wild type and mdx mice. WFA binding and enhancement by lobeline required complex N-glycans but not O-mannose glycans that bind laminin. However, inhibiting complex N-glycan processing reduced laminin binding to muscle cell glycoproteins, although O-mannosylation was intact. Glycan analysis demonstrated a general increase in N-glycans on lobeline-treated cells rather than specific alterations in cell surface glycosylation, consistent with increased abundance of multiple sarcolemmal glycoproteins. This demonstrates the feasibility of high throughput screening with plant lectins to identify compounds that alter muscle cell glycosylation and identifies a novel role for N-glycans in regulating muscle cell function. PMID:22570487

Adjustment of Host Cells for Accommodation of Symbiotic Bacteria: Vacuole Defunctionalization, HOPS Suppression, and TIP1g Retargeting in Medicago[C][W][OPEN

PubMed Central

Gavrin, Aleksandr; Kaiser, Brent N.; Geiger, Dietmar; Tyerman, Stephen D.; Wen, Zhengyu; Bisseling, Ton; Fedorova, Elena E.

2014-01-01

In legume–rhizobia symbioses, the bacteria in infected cells are enclosed in a plant membrane, forming organelle-like compartments called symbiosomes. Symbiosomes remain as individual units and avoid fusion with lytic vacuoles of host cells. We observed changes in the vacuole volume of infected cells and thus hypothesized that microsymbionts may cause modifications in vacuole formation or function. To examine this, we quantified the volumes and surface areas of plant cells, vacuoles, and symbiosomes in root nodules of Medicago truncatula and analyzed the expression and localization of VPS11 and VPS39, members of the HOPS vacuole-tethering complex. During the maturation of symbiosomes to become N2-fixing organelles, a developmental switch occurs and changes in vacuole features are induced. For example, we found that expression of VPS11 and VPS39 in infected cells is suppressed and host cell vacuoles contract, permitting the expansion of symbiosomes. Trafficking of tonoplast-targeted proteins in infected symbiotic cells is also altered, as shown by retargeting of the aquaporin TIP1g from the tonoplast membrane to the symbiosome membrane. This retargeting appears to be essential for the maturation of symbiosomes. We propose that these alterations in the function of the vacuole are key events in the adaptation of the plant cell to host intracellular symbiotic bacteria. PMID:25217511

STATs in NK-Cells: The Good, the Bad, and the Ugly.

PubMed

Gotthardt, Dagmar; Sexl, Veronika

2016-01-01

Natural killer (NK)-cells are major players in the fight against viral infections and transformed cells, but there is increasing evidence attributing a disease-promoting role to NK-cells. Cytokines present in the tumor microenvironment shape NK-cell maturation, function, and effector responses. Many cytokines signal via the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway that is also frequently altered and constitutively active in a broad range of tumor cells. As a consequence, there are currently major efforts to develop therapeutic strategies to target this pathway. Therefore, it is of utmost importance to understand the role and contributions of JAK-STAT molecules in NK-cell biology-only this knowledge will allow us to predict effects of JAK-STAT inhibition for NK-cell functions and to successfully apply precision medicine. We will review the current knowledge on the role of JAK-STAT signaling for NK-cell functions and discuss conditions involved in the switch from NK-cell tumor surveillance to disease promotion.

Myeloid-derived suppressor activity is mediated by monocytic lineages maintained by continuous inhibition of extrinsic and intrinsic death pathways.

PubMed

Haverkamp, Jessica M; Smith, Amber M; Weinlich, Ricardo; Dillon, Christopher P; Qualls, Joseph E; Neale, Geoffrey; Koss, Brian; Kim, Young; Bronte, Vincenzo; Herold, Marco J; Green, Douglas R; Opferman, Joseph T; Murray, Peter J

2014-12-18

Nonresolving inflammation expands a heterogeneous population of myeloid suppressor cells capable of inhibiting T cell function. This heterogeneity has confounded the functional dissection of individual myeloid subpopulations and presents an obstacle for antitumor immunity and immunotherapy. Using genetic manipulation of cell death pathways, we found the monocytic suppressor-cell subset, but not the granulocytic subset, requires continuous c-FLIP expression to prevent caspase-8-dependent, RIPK3-independent cell death. Development of the granulocyte subset requires MCL-1-mediated control of the intrinsic mitochondrial death pathway. Monocytic suppressors tolerate the absence of MCL-1 provided cytokines increase expression of the MCL-1-related protein A1. Monocytic suppressors mediate T cell suppression, whereas their granulocytic counterparts lack suppressive function. The loss of the granulocytic subset via conditional MCL-1 deletion did not alter tumor incidence implicating the monocytic compartment as the functionally immunosuppressive subset in vivo. Thus, death pathway modulation defines the development, survival, and function of myeloid suppressor cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Metabolic changes in tumor cells and tumor-associated macrophages: A mutual relationship.

PubMed

Netea-Maier, Romana T; Smit, Johannes W A; Netea, Mihai G

2018-01-28

In order to adapt to the reduced availability of nutrients and oxygen in the tumor microenvironment and the increased requirements of energy and building blocks necessary for maintaining their high proliferation rate, malignant cells undergo metabolic changes that result in an increased production of lactate, nitric oxide, reactive oxygen species, prostaglandins and other byproducts of arachidonic acid metabolism that influence both the composition of the inflammatory microenvironment and the function of the tumor-associated macrophages (TAMs). In response to cues present in the TME, among which products of altered tumor cell metabolism, TAMs are also required to reprogram their metabolism, with activation of glycolysis, fatty acid synthesis and altered nitrogen cycle metabolism. These changes result in functional reprogramming of TAMs which includes changes in the production of cytokines and angiogenetic factors, and contribute to the tumor progression and metastasis. Understanding the metabolic changes governing the intricate relationship between the tumor cells and the TAMs represents an essential step towards developing novel therapeutic approaches targeting the metabolic reprogramming of the immune cells to potentiate their tumoricidal potential and to circumvent therapy resistance. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Time-resolved optical imaging provides a molecular snapshot of altered metabolic function in living human cancer cell models

NASA Astrophysics Data System (ADS)

Sud, Dhruv; Zhong, Wei; Beer, David G.; Mycek, Mary-Ann

2006-05-01

A fluorescence lifetime imaging microscopy (FLIM) method was developed and applied to investigate metabolic function in living human normal esophageal (HET-1) and Barrett’s adenocarcinoma (SEG-1) cells. In FLIM, image contrast is based on fluorophore excited state lifetimes, which reflect local biochemistry and molecular activity. Unique FLIM system attributes, including variable ultrafast time gating (≥ 200 ps), wide spectral tunability (337.1 - 960 nm), large temporal dynamic range (≥ 600 ps), and short data acquisition and processing times (15 s), enabled the study of two key molecules consumed at the termini of the oxidative phosphorylation pathway, NADH and oxygen, in living cells under controlled and calibrated environmental conditions. NADH is an endogenous cellular fluorophore detectable in living human tissues that has been shown to be a quantitative biomarker of dysplasia in the esophagus. Lifetime calibration of an oxygen-sensitive, ruthenium-based cellular stain enabled in vivo oxygen level measurements with a resolution of 8 μM over the entire physiological range (1 - 300 μM). Starkly higher intracellular oxygen and NADH levels in living SEG-1 vs. HET-1 cells were detected by FLIM and attributed to altered metabolic pathways in malignant cells.

NUMB does not impair growth and differentiation status of experimental gliomas

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

Euskirchen, Philipp, E-mail: philipp.euskirchen@charite.de; Laboratory for Gene Therapy and Molecular Imaging, Max-Planck-Institute for Neurological Research, Cologne; Skaftnesmo, Kai-Ove

2011-12-10

The cell fate determinant NUMB orchestrates asymmetric cell division in flies and mammals and has lately been suggested to have a tumor suppressor function in breast and lung cancer. Here, we studied NUMB in the context of malignant gliomas. We used ectopic expression of NUMB in order to inhibit proliferation and induce differentiation in glioma cells by alteration of Notch, Hedgehog and p53 signaling. We found that NUMB is consistently expressed in glioma biopsies with predominance of NUMB2/4 isoforms as determined by isoform-specific real-time PCR and Western blotting. Upon lentiviral overexpression, in vitro proliferation rate and the grade of differentiationmore » as assessed by morphology and expression of neural and glial markers remained unchanged. Orthotopic xenografts of NUMB-transduced human U87 glioma cells could be established in nude rats without impairing engraftment or causing significant changes in morphology based on magnetic resonance imaging (MRI). The previously reported alteration of Hedgehog and p53 signaling by NUMB could not be recapitulated in glioma cells. We thus show that in experimental gliomas, NUMB overexpression most likely does not exert a tumor suppressor function such as seen in epithelial cancers.« less

Loss of function JAK1 mutations occur at high frequency in cancers with microsatellite instability and are suggestive of immune evasion.

PubMed

Albacker, Lee A; Wu, Jeremy; Smith, Peter; Warmuth, Markus; Stephens, Philip J; Zhu, Ping; Yu, Lihua; Chmielecki, Juliann

2017-01-01

Immune evasion is a well-recognized hallmark of cancer and recent studies with immunotherapy agents have suggested that tumors with increased numbers of neoantigens elicit greater immune responses. We hypothesized that the immune system presents a common selective pressure on high mutation burden tumors and therefore immune evasion mutations would be enriched in high mutation burden tumors. The JAK family of kinases is required for the signaling of a host of immune modulators in tumor, stromal, and immune cells. Therefore, we analyzed alterations in this family for the hypothesized signature of an immune evasion mutation. Here, we searched a database of 61,704 unique solid tumors for alterations in the JAK family kinases (JAK1/2/3, TYK2). We used The Cancer Genome Atlas and Cancer Cell Line Encyclopedia data to confirm and extend our findings by analyzing gene expression patterns. Recurrent frameshift mutations in JAK1 were associated with high mutation burden and microsatellite instability. These mutations occurred in multiple tumor types including endometrial, colorectal, stomach, and prostate carcinomas. Analyzing gene expression signatures in endometrial and stomach adenocarcinomas revealed that tumors with a JAK1 frameshift exhibited reduced expression of interferon response signatures and multiple anti-tumor immune signatures. Importantly, endometrial cancer cell lines exhibited similar gene expression changes that were expected to be tumor cell intrinsic (e.g. interferon response) but not those expected to be tumor cell extrinsic (e.g. NK cells). From these data, we derive two primary conclusions: 1) JAK1 frameshifts are loss of function alterations that represent a potential pan-cancer adaptation to immune responses against tumors with microsatellite instability; 2) The mechanism by which JAK1 loss of function contributes to tumor immune evasion is likely associated with loss of the JAK1-mediated interferon response.

The potential role of the osteoblast in the development of periprosthetic osteolysis: review of in vitro osteoblast responses to wear debris, corrosion products, and cytokines and growth factors.

PubMed

Vermes, C; Glant, T T; Hallab, N J; Fritz, E A; Roebuck, K A; Jacobs, J J

2001-12-01

Limited information is available on the responses of osteoblasts to wear debris, corrosion products, and cytokines and on the roles of altered osteoblast functions in the development of periprosthetic bone loss. Wear debris-challenged osteoblasts exhibit altered functions resulting in the loss of their capacity to produce bone matrix and to replace the resorbed bone. Also, osteoblasts may secrete cytokines, which act in a paracrine fashion to recruit inflammatory cells into the periprosthetic space and to stimulate osteoclastic bone resorption. These effects may be mediated in part by ionic metal dissolution products. We review the mechanisms by which altered osteoblast functions, in response to particulate wear debris, corrosion products, and cytokines and growth factors, may contribute to the development and the progression of periprosthetic osteolysis.

IDO2 is a critical mediator of autoantibody production and inflammatory pathogenesis in a mouse model of autoimmune arthritis1

PubMed Central

DuHadaway, James B.; Grabler, Samantha; Metz, Richard; Prendergast, George C.; Mandik-Nayak, Laura

2014-01-01

Rheumatoid arthritis (RA) and other autoimmune disorders are associated with altered activity of the immunomodulatory enzyme indoleamine-2,3-dioxygenase (IDO). However, the precise contributions of IDO function to autoimmunity remain unclear. Here, we examine the effect of two different IDO enzymes, IDO1 and IDO2, on the development of autoimmune arthritis in the KRN preclinical model of RA. We find that IDO2, not IDO1, is critical for arthritis development, providing the first direct evidence of separate in vivo functions for IDO1 and IDO2. Mice null for Ido2 display decreased joint inflammation relative to wild-type mice due to a reduction in pathogenic autoantibodies and antibody secreting cells. Notably, IDO2 appears to specifically mediate autoreactive, but not normal B cell responses, as total serum Ig levels are not altered and IDO2 ko mice are able to mount productive antibody responses to model antigens in vitro and in vivo. Reciprocal adoptive transfer studies confirm that autoantibody production and arthritis are modulated by IDO2 expression in a cell type extrinsic to the T cell. Taken together, our results provide the first insights into IDO2 function by defining its pathogenic contributions to autoantibody-mediated autoimmunity. PMID:24489090

IDO2 is a critical mediator of autoantibody production and inflammatory pathogenesis in a mouse model of autoimmune arthritis.

PubMed

Merlo, Lauren M F; Pigott, Elizabeth; DuHadaway, James B; Grabler, Samantha; Metz, Richard; Prendergast, George C; Mandik-Nayak, Laura

2014-03-01

Rheumatoid arthritis and other autoimmune disorders are associated with altered activity of the immunomodulatory enzyme IDO. However, the precise contributions of IDO function to autoimmunity remain unclear. In this article, we examine the effect of two different IDO enzymes, IDO1 and IDO2, on the development of autoimmune arthritis in the KRN preclinical model of rheumatoid arthritis. We find that IDO2, not IDO1, is critical for arthritis development, providing direct evidence of separate in vivo functions for IDO1 and IDO2. Mice null for Ido2 display decreased joint inflammation relative to wild-type mice owing to a reduction in pathogenic autoantibodies and Ab-secreting cells. Notably, IDO2 appears to specifically mediate autoreactive responses, but not normal B cell responses, as total serum Ig levels are not altered and IDO2 knockout mice are able to mount productive Ab responses to model Ags in vitro and in vivo. Reciprocal adoptive transfer studies confirm that autoantibody production and arthritis are modulated by IDO2 expression in a cell type extrinsic to the T cell. Taken together, our results, provide important insights into IDO2 function by defining its pathogenic contributions to autoantibody-mediated autoimmunity.

Impaired osteoblast differentiation in Annexin A2- and -A5-deficient cells

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

Genetos, Damian C.; Wong, Alice; Weber, Thomas J.

Annexins are a class of calcium-binding proteins with diverse functions in the regulation of lipid rafts inflammation,fibrinolysis, transcriptional programming and ion transport. Within bone, they are well-characterized as components of mineralizing matrix vesicles, although little else is known as to their function during osteogenesis. We generated annexin A2 (AnxA2)- or annexin A5 (AnxA5)-knockdown pre-osteoblasts, and asked whether proliferation or osteogenic differentiation was altered in knockdown cells, compared to vector controls. We report that DNA content, a marker of proliferation, was significantly reduced in both AnxA2 and AnxA5 knockdown cells. Alkaline phosphatase expression and staining activity were also suppressed in AnxA2-more » or AnxA5-knockdown after 14 days of culture. The pattern of osteogenic gene expression was altered in knockdown cells, with Col1a1 expressed more rapidly in knock-down cells, compared to controls. In contrast, Runx2, Ibsp, and Bglap all revealed decreased expression after 14 days of culture. Using a murine fracture model, we demonstrate that AnxA2 and AnxA5 are rapidly expressed within the fracture callus. These data demonstrate that AnxA2 and AnxA5 can influence bone formation via regulation of osteoprogenitor proliferation and differentiation in addition to their well-studied function in matrix vesicles.« less

Effects of DDT and Triclosan on Tumor-cell Binding Capacity and Cell-Surface Protein Expression of Human Natural Killer Cells

PubMed Central

Hurd-Brown, Tasia; Udoji, Felicia; Martin, Tamara; Whalen, Margaret M.

2012-01-01

1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) and triclosan (TCS) are organochlorine (OC) compounds that contaminate the environment, are found in human blood, and have been shown to decrease the tumor-cell killing (lytic) function of human natural killer (NK) cells. NK cells defend against tumor cells and virally infected cells. They bind to these targets, utilizing a variety of cell surface proteins. This study examined concentrations of DDT and TCS that decrease lytic function for alteration of NK binding to tumor targets. Levels of either compound that caused loss of binding function were then examined for effects on expression of cell-surface proteins needed for binding. NK cells exposed to 2.5 μM DDT for 24 h (which caused a greater than 55% loss of lytic function) showed a decrease in NK binding function of about 22%, and a decrease in CD16 cell-surface protein of 20%. NK cells exposed to 5 μM TCS for 24 h showed a decrease in ability to bind tumor cells of 37% and a decrease in expression of CD56 of about 34%. This same treatment caused a decrease in lytic function of greater than 87%. These results indicated that only a portion of the loss of NK lytic function seen with exposures to these compounds could be accounted for by loss of binding function. They also showed that loss of binding function is accompanied by a loss cell-surface proteins important in binding function. PMID:22729613

Dbl oncogene expression in MCF-10 A epithelial cells disrupts mammary acinar architecture, induces EMT and angiogenic factor secretion

PubMed Central

Vanni, Cristina; Ognibene, Marzia; Finetti, Federica; Mancini, Patrizia; Cabodi, Sara; Segalerba, Daniela; Torrisi, Maria Rosaria; Donnini, Sandra; Bosco, Maria Carla; Varesio, Luigi; Eva, Alessandra

2015-01-01

The proteins of the Dbl family are guanine nucleotide exchange factors (GEFs) of Rho GTPases and are known to be involved in cell growth regulation. Alterations of the normal function of these proteins lead to pathological processes such as developmental disorders, neoplastic transformation, and tumor metastasis. We have previously demonstrated that expression of Dbl oncogene in lens epithelial cells modulates genes encoding proteins involved in epithelial-mesenchymal-transition (EMT) and induces angiogenesis in the lens. Our present study was undertaken to investigate the role of Dbl oncogene in epithelial cells transformation, providing new insights into carcinoma progression.To assess how Dbl oncogene can modulate EMT, cell migration, morphogenesis, and expression of pro-apoptotic and angiogenic factors we utilized bi- and 3-dimensional cultures of MCF-10 A cells. We show that upon Dbl expression MCF-10 A cells undergo EMT. In addition, we found that Dbl overexpression sustains Cdc42 and Rac activation inducing morphological alterations, characterized by the presence of lamellipodia and conferring a high migratory capacity to the cells. Moreover, Dbl expressing MCF-10 A cells form altered 3D structures and can induce angiogenesis by producing proangiogenic factors such as CCL2. These results support a role for Dbl oncogene in epithelial cell differentiation and transformation and suggest the relevance of GEF deregulation in tumor onset and progression. PMID:25723869

Molecular control of steady-state dendritic cell maturation and immune homeostasis.

PubMed

Hammer, Gianna Elena; Ma, Averil

2013-01-01

Dendritic cells (DCs) are specialized sentinels responsible for coordinating adaptive immunity. This function is dependent upon coupled sensitivity to environmental signs of inflammation and infection to cellular maturation-the programmed alteration of DC phenotype and function to enhance immune cell activation. Although DCs are thus well equipped to respond to pathogens, maturation triggers are not unique to infection. Given that immune cells are exquisitely sensitive to the biological functions of DCs, we now appreciate that multiple layers of suppression are required to restrict the environmental sensitivity, cellular maturation, and even life span of DCs to prevent aberrant immune activation during the steady state. At the same time, steady-state DCs are not quiescent but rather perform key functions that support homeostasis of numerous cell types. Here we review these functions and molecular mechanisms of suppression that control steady-state DC maturation. Corruption of these steady-state operatives has diverse immunological consequences and pinpoints DCs as potent drivers of autoimmune and inflammatory disease.

Effects of alterd Gravity and Phosphorilation inhibitor 2.4-Dinitrophenole on Mitochondria Ultrastructural Organization in Chlorella Cells

NASA Astrophysics Data System (ADS)

Popova, A.

The results of the experiments with two species of a green alga ?hlorella in spaceflight conditions and under altered gravity testified that the regular rearrangements has been revealed first of all in the cell mitochondriome. Such reorganizations were observed at auto- and geterotrophic regimes of the culture growth in the experiments of average duration (9-18 days) and also in long-term experiments (30 days - 4.5 months) (Popova, 1999). The mitochondria rearrangements become apparent at intensification of the cell proliferation, which results in increasing a relative volume of the mitohondria per cell (up to 5.3 % in microgravity compared to the control - 2.1 %). Moreover, the size of these organelles and their cristae increased in the experimental cells. The indicated mitochondria changes were accompanied by intensifying the electron density of a matrix and often by well-ordered topography of the cristae. Taking into account that the main set of the enzymes catalyzing the oxidative phosphorylation and conduction of the electrons are localized in the cristae membranes, the considerable growth of the mitochondria size and the cristae areas testified probably about a high functional activity of these organelles. Our investigations were carried out with the purpose to check the functional state of mitochondria under altered gravity (using slow horizontal clinorotator) and under influence of the inhibitory agent, separating an oxidation and oxidative phosphorylation. The ultrastructural peculiarities of the mitochondria as the energetic organelles were studied under the different 2,4- dinitrophenole concentrations and during the different terms of clinoritation at the logarithmic and stationary phases of Chlorella culture growth. The various characters of the mitochondria rearrangements and their relative volumes per cell were revealed under 2,4-dinitrophenole influence compared to the different terms of microgravity and altered gravity influences. The obtained results about various ultrastructural mitochondrial rearrangements and their total volume per cell under influence of 2,4- dinitrophenole are discussed by help of the obtained early data of adenylate content, activity, and topography of Mg2+-activated-ATPase in Chlorella cells under altered gravity.

Senescence-Derived Extracellular Molecules as Modulators of Oral Cancer Development: A Mini-Review.

PubMed

Parkinson, Eric Kenneth; James, Emma L; Prime, Stephen S

2016-01-01

Oral cancers are predominantly oral squamous cell carcinomas (OSCCs) derived from keratinocytes, and there is now very detailed knowledge of the genetics and molecular biology of the epithelial tumourigenic component of these cancers, including the identification of cancer stem or tumour-initiating cells. Several key genetic alterations have been identified including the near ubiquitous loss of the CDKN2A/p16INK4A and p53 pathways and telomerase activation, together with frequent inactivation of the NOTCH1 canonical pathway either by somatic genetic alterations or by the presence of human papilloma virus. There is also evidence that OSCCs arise from a 'field' of altered cells and that malignant conversion takes place pre-dominantly at the microscopic level. However, in the last decade, it has been realised that tumour development and progression are influenced by the cells of the microenvironment with cross-talk between the epithelial (tumour) and mesenchymal components. OSCCs, especially those that have bypassed cellular senescence, produce an array of proteins and metabolites that induce cellular senescence in the normal surrounding cells; indeed, senescence is a common property of cancer-associated fibroblasts (CAFs). Cellular senescence is defined as an irreversible cell cycle arrest and is associated with the release of molecules known as the senescence-associated secretory phenotype that can selectively promote the growth of pre-neoplastic keratinocytes (osteopontin) and cancer invasion (transforming growth factor β, matrix metalloproteinases, interleukin 6 and lactate). In addition, both old and new work has shown that keratinocytes harbouring NOTCH loss-of-function mutations that lead to defective keratinocyte differentiation and loss of squamous epithelial barrier function may act as a tumour-promoting stimulus for initiated cells harbouring RAS pathway mutations by activating a wound response in the tumour mesenchyme. Thus, not all keratinocytes in the tumour tissue may be tumourigenic and may instead act as promoters of tumour growth and progression analogous to the much-studied CAFs which co-evolve with the genetically altered tumourigenic cells. This new data is discussed in relation to attempts to develop novel non-invasive diagnostics and therapeutics for oral cancer. © 2015 S. Karger AG, Basel.

Altered phenotype and function of NK cells infiltrating human papillomavirus (HPV)-associated genital warts during HIV infection.

PubMed

Bere, Alfred; Tayib, Shahila; Kriek, Jean-Mari; Masson, Lindi; Jaumdally, Shameem Z; Barnabas, Shaun L; Carr, William H; Allan, Bruce; Williamson, Anna-Lise; Denny, Lynette; Passmore, Jo-Ann S

2014-02-01

HIV-infected individuals experience more persistent HPV infections and are less likely to resolve genital warts. This study compared phenotype and functions of NK and T cells from genital warts and blood from 67 women. We compared in vitro functional responses of NK and T cells by multiparametric flow cytometry. HIV+ women had significantly lower frequencies of CD4 T cells in warts (p = 0.001) and blood (p = 0.001). While the distribution of NK cell subsets was similar, HIV+ women tended to have lower frequencies of CD56(Dim) NK cells in both blood (p = 0.0001) and warts (p = 0.006) than HIV- women. Wart NK cells from HIV+ women expressed significantly lower CD107a and produced IFN-γ. HAART status was not associated with differences in NK cell functionality. We conclude that wart NK cells from HIV+ women have defects in their ability to degranulate and/or secrete IFN-γ, which may provide insights into why HIV+ women fail to spontaneously resolve genital warts. Copyright © 2013 Elsevier Inc. All rights reserved.

Telmisartan enhances mitochondrial activity and alters cellular functions in human coronary artery endothelial cells via AMP-activated protein kinase pathway.

PubMed

Kurokawa, Hirofumi; Sugiyama, Seigo; Nozaki, Toshimitsu; Sugamura, Koichi; Toyama, Kensuke; Matsubara, Junichi; Fujisue, Koichiro; Ohba, Keisuke; Maeda, Hirofumi; Konishi, Masaaki; Akiyama, Eiichi; Sumida, Hitoshi; Izumiya, Yasuhiro; Yasuda, Osamu; Kim-Mitsuyama, Shokei; Ogawa, Hisao

2015-04-01

Mitochondrial dysfunction plays an important role in cellular senescence and impaired function of vascular endothelium, resulted in cardiovascular diseases. Telmisartan is a unique angiotensin II type I receptor blocker that has been shown to prevent cardiovascular events in high risk patients. AMP-activated protein kinase (AMPK) plays a critical role in mitochondrial biogenesis and endothelial function. This study assessed whether telmisartan enhances mitochondrial function and alters cellular functions via AMPK in human coronary artery endothelial cells (HCAECs). In cultured HCAECs, telmisartan significantly enhanced mitochondrial activity assessed by mitochondrial reductase activity and intracellular ATP production and increased the expression of mitochondria related genes. Telmisartan prevented cellular senescence and exhibited the anti-apoptotic and pro-angiogenic properties. The expression of genes related anti-oxidant and pro-angiogenic properties were increased by telmisartan. Telmisartan increased endothelial NO synthase and AMPK phosphorylation. Peroxisome proliferator-activated receptor gamma signaling was not involved in telmisartan-induced improvement of mitochondrial function. All of these effects were abolished by inhibition of AMPK. Telmisartan enhanced mitochondrial activity and exhibited anti-senescence effects and improving endothelial function through AMPK in HCAECs. Telmisartan could provide beneficial effects on vascular diseases via enhancement of mitochondrial activity and modulating endothelial function through AMPK activation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Low-Level Laser Effect on Proliferation, Migration, and Antiapoptosis of Mesenchymal Stem Cells.

PubMed

Yin, Kan; Zhu, Rongjia; Wang, Shihua; Zhao, Robert Chunhua

2017-05-15

Mesenchymal stem cells (MSCs) have been proved to be an important element in cell-based therapy. Photobiomodulation used extremely low-level lasers (LLLs) to affect the behavior of cells. The effect mechanism of LLLs on MSCs from human remained to be discovered. In this study, cell viability was assessed using MTS assays and cell cycle was evaluated by fluorescence-activated cell sorting (FACS). The influence of LLLs on mitochondrial biogenesis (fission or fusion) and function (ATP, reactive oxygen species [ROS], nitric oxide [NO]) was evaluated by transmission electron microscope, FACS, quantitative real time polymerase chain reaction (q-PCR), and immunocytochemistry. Cell migration and cytoskeleton alteration (actin and tubulin) were evaluated using transwell assay, immunocytochemistry, enzyme-linked immunosorbent assay, and western blotting. Cell apoptosis was evaluated using FACS, immunocytochemistry, and western blotting. We investigated that certain influence of LLLs on MSCs in vitro 6 or 24 h after 1 h of LLL irradiation. The mechanism of the effects included proliferation rate increase mediated by increased S phase proportion; mitochondrial biogenesis and function alteration mediated by fusion (Mfn1, Mfn2, and Opa-1) and fission (Fis1, Drp-1, and MTP18)-related proteins, NRF1, TFAM, PGC-1a, and upregulated intracellular ROS and NO concentration; migration acceleration through the ERK1/2 and FAK pathway and upregulation of growth factors such as HGF and PDGF; and resistance to apoptosis with increased Bcl-2 and decreased Bax, or through tunneling nanotube formation between LLL-treated MSCs and 5-fluorouracil-induced apoptotic MSCs. These observations suggested that LLLs enhanced stem cell survival and therapeutic function, which could appear to be an innovative pretreatment in the application of MSCs.

Specific role of impaired glucose metabolism and diabetes mellitus in endothelial progenitor cell characteristics and function.

PubMed

Yiu, Kai-Hang; Tse, Hung-Fat

2014-06-01

The disease burden of diabetes mellitus (DM) and its associated cardiovascular complications represent a growing and major global health problem. Recent studies suggest that circulating exogenous endothelial progenitor cells (EPCs) play an important role in endothelial repair and neovascularization at sites of injury or ischemia. Both experimental and clinical studies have demonstrated that hyperglycemia related to DM can induce alterations to EPCs. The reduction and dysfunction of EPCs related to DM correlate with the occurrence and severity of microvascular and macrovascular complications, suggesting a close mechanistic link between EPC dysfunction and impaired vascular function/repair in DM. These alterations to EPCs, likely mediated by multiple pathophysiological mechanisms, including inflammation, oxidative stress, and alterations in Akt and the nitric oxide pathway, affect EPCs at multiple stages: differentiation and mobilization in the bone marrow, trafficking and survival in the circulation, and homing and neovascularization. Several different therapeutic approaches have consequently been proposed to reverse the reduction and dysfunction of EPCs in DM and may represent a novel therapeutic approach to prevent and treat DM-related cardiovascular complications. © 2014 American Heart Association, Inc.

Alterations induced by E-cadherin and beta-catenin antibodies during the development of Bufo arenarum (Anura-Bufonidae).

PubMed

Izaguirre, M F; Adur, J F; Soler, A P; Casco, V H

2001-10-01

E(epithelial)-cadherin is a member of a calcium-dependent family of cell surface glycoproteins involved in cell-cell adhesion and morphogenesis. Catenins are a large family of proteins that connect the cadherins to the cytoskeleton. They are important for cadherin function and for transducing signals involved in specification of cell fate during embryogenesis. The best characterized catenins include alpha-, beta-, gamma-, and p120-catenin. Using specific antibodies, we studied the expression and distribution of E-cadherin, and alpha- and beta-catenin in developmental stages of Bufo arenarum toad. The three proteins were found co-localized in stages 19 to 41 of development. Surprisingly, E-cadherin was the only of these three proteins found earlier than stage 19. To test whether E-cadherin and beta-catenin have a functional role in Bufo arenarum embryogenesis, stage 17 whole embryos were incubated with anti-E-cadherin and beta-catenin antibodies. Both anti-E-cadherin and anti-beta-catenin antibodies induced severe morphological alterations. However, while alterations produced by the anti-beta-catenin antibody, showed some variability from the most severe (neural tube and notochord duplication) to a simple delay in development, the alterations with anti-E-cadherin were homogeneous. These observations suggest a critical role for E-cadherin and beta-catenin in the early embryonic development of the Bufo arenarum toad. Our results are consistent with the developmental role of these proteins in other species. One of the most surprising findings was the blockage with the anti-beta-catenin antibodies on later embryo stages, and we hypothesize that the partial axes duplication could be mediated by the notochord induction.

Lymphatic dysregulation in intestinal inflammation: new insights into inflammatory bowel disease pathomechanisms.

PubMed

Becker, F; Yi, P; Al-Kofahi, M; Ganta, V C; Morris, J; Alexander, J S

2014-03-01

Alterations in the intestinal lymphatic network are well-established features of human and experimental inflammatory bowel disease (IBD). Such lymphangiogenic expansion might enhance classic intestinal lymphatic transport, eliminating excess accumulations of fluid, inflammatory cells and mediators, and could therefore be interpreted as an 'adaptive' response to acute and chronic inflammatory processes. However, whether these new lymphatic vessels are functional, unregulated or immature (and what factors may promote 'maturation' of these vessels) is currently an area under intense investigation. It is still controversial whether impaired lymphatic function in IBD is a direct consequence of the intestinal inflammation, or a preceding lymphangitis-like event. Current research has uncovered novel regulatory factors as well as new roles for familiar signaling pathways, which appear to be linked to inflammation-induced lymphatic alterations. The current review summarizes mechanisms amplifying lymphatic dysregulation and remodeling in intestinal inflammation at the organ, cell and molecular levels and discusses the influence of lymphangiogenesis and intestinal lymphatic transport function as they relate to IBD pathophysiology.

The toxic Doppelganger: on the ionic and molecular mimicry of cadmium.

PubMed

Chmielowska-Bąk, Jagna; Izbiańska, Karolina; Deckert, Joanna

2013-01-01

Cadmium is a toxic heavy metal which can cause numerous alterations in cell functioning. Exposure to cadmium leads to generation of reactive oxygen species, disorders in membrane structure and functioning, inhibition of respiration, disturbances in ion homeostasis, perturbations in cell division, and initiation of apoptosis and necrosis. This heavy metal is considered a carcinogen by the Agency for Toxic Substances and Disease Registry. At least some of the described toxic effects could result from the ability of cadmium to mimic other divalent ions and alert signal transduction networks. This review describes the role of cadmium mimicry in its uptake, reactive oxygen species generation, alterations in calmodulin, Wnt/β-catenin and estrogen signaling pathways, and modulation of neurotransmission. The last section is dedicated to the single known case of a favorable function performed by cadmium mimicry: marine diatoms, which live in zinc deficient conditions, utilize cadmium as a cofactor in carbonic anhydrase - so far the only described cadmium enzyme.

TCR and IL-7 Signaling Are Altered in the Absence of Functional GTPase of the Immune Associated Nucleotide Binding Protein 5 (GIMAP5)

PubMed Central

Chen, Xi-Lin; Serrano, Daniel; Ghobadi, Farnaz; Mayhue, Marian; Hoebe, Kasper; Ilangumaran, Subburaj; Ramanathan, Sheela

2016-01-01

GTPase of the immune associated nucleotide binding protein (GIMAP) family of proteins are expressed essentially in cells of the hematopoietic system. Mutation in the founding member of this gene family, Gimap5, results in the lymphopenic phenotype in Bio-Breeding diabetes prone rats. In mice, deletion of functional Gimap5 gene affects the survival and renewal of hematopoietic stem cells in addition to the defects observed in T cells. Here we show that T cells from OTII TCR-transgenic Gimap5sph/sph mice do not proliferate in response to its cognate antigen. Furthermore, T cells from Gimap5 mutant rats and mice show decreased phosphorylation of STAT5 following stimulation with IL-7. Our results suggest that functional Gimap5 is required for optimal signaling through TCR and IL-7R in T cells. PMID:27023180

Obesity associated advanced glycation end products within the human uterine cavity adversely impact endometrial function and embryo implantation competence.

PubMed

Antoniotti, Gabriella S; Coughlan, Melinda; Salamonsen, Lois A; Evans, Jemma

2018-04-01

Do obese levels of advanced glycation end products (AGEs) within the uterine cavity detrimentally alter tissue function in embryo implantation and placental development? Obese levels of AGEs activate inflammatory signaling (p65 NFκB) within endometrial epithelial cells and alter their function, cause endoplasmic reticulum (ER) stress in endometrial stromal cells and impair decidualization, compromise implantation of blastocyst mimics and inhibit trophoblast invasion. Obese women experience a higher incidence of infertility, recurrent miscarriage and pregnancy complications compared with lean women. Oocyte donation cycles suggest a detrimental uterine environment plays a role in these outcomes. Uterine lavage and tissues from lean (BMI 19.5-24.9, n = 17) and obese (BMI > 30, n = 16) women examined. Cell culture experiments utilizing human endometrial epithelial, trophectoderm and trophoblast cell lines and primary human stromal cells used to examine the functional impact of obese levels of AGEs. Levels of AGEs examined within uterine lavage assessed by ELISA to determine differences between lean and obese women. Expression and localization of AGEs, receptor for AGEs (RAGE) and NFκB within endometrial tissues obtained from lean and obese women determined by immunohistochemistry. Endometrial epithelial cells (ECC-1), primary human stromal cells and trophoblast cells (HTR8-SVneo) treated with lean (2000 nmol/mol lysine) or obese (8000 nmol/mol lysine) uterine levels of AGEs and p65 NFκB (western immunoblot), real-time adhesion, proliferation migration and invasion (xCelligence real-time cell function analysis), decidualization (cell morphology and prolactin release), ER stress (western immunoblot for p-PERK) determined. Co-cultures of endometrial epithelial cells and blastocyst mimics (trophectoderm spheroids) similarly treated with lean or obese uterine levels of AGEs to determine their impact on embryo implantation. AGEs were significantly elevated (P = 0.004) within the obese (6503.59 μmol/mol lysine) versus lean (2165.88 μmol/mol lysine) uterine cavity (uterine lavage) with increased immunostaining for AGEs, RAGE and NFkB within obese endometrial tissues during the proliferative phase of the menstrual cycle. Obese uterine levels of AGEs inhibited adhesion and proliferation of endometrial epithelial (ECC-1) cells compared to treatment with lean uterine levels of AGEs. Obese uterine AGE levels impacted primary human endometrial stromal cell decidualization and activated ER stress within these cells. Obese uterine levels of AGEs also inhibited trophectodermal spheroid adhesion to hormonally primed endometrial epithelial cells and trophoblast cell line HTR8/SV-neo invasion. N/A. Mechanistic studies are performed in vitro and may not completely recapitulate cell function in vivo. These data corroborate clinical data suggesting the presence of an altered uterine environment in obese women and demonstrate that elevated uterine levels of AGEs within these women may detrimentally impact endometrial function, embryo implantation and placental development. Uterine AGE assessment in infertility work up may prove useful in determining underlying causes of infertility. AGEs can be targeted pharmacologically and such treatments may prove effective in improving reproductive complications experience by obese women. Supported by NHMRC Fellowship (#1002028 to L.A.S.), and the Victorian Government's Operational Infrastructure Support Program. MTC is supported by a JDRF Australia Clinical Research Network Career Development Award. The authors have declared that no conflict of interest exists.

Annexin A1 influences in breast cancer: Controversies on contributions to tumour, host and immunoediting processes.

PubMed

Tu, Yan; Johnstone, Cameron N; Stewart, Alastair G

2017-05-01

Annexin A1 is a multifunctional protein characterised by its actions in modulating the innate and adaptive immune response. Accumulating evidence of altered annexin A1 expression in many human tumours raises interest in its functional role in cancer biology. In breast cancer, altered annexin A1 expression levels suggest a potential influence on tumorigenic and metastatic processes. However, reports of conflicting results reveal a relationship that is much more complex than first conceptualised. In this review, we explore the diverse actions of annexin A1 on breast tumour cells and various host cell types, including stromal immune and structural cells, particularly in the context of cancer immunoediting. Copyright © 2017 Elsevier Ltd. All rights reserved.

Graphene-Based Interfaces Do Not Alter Target Nerve Cells.

PubMed

Fabbro, Alessandra; Scaini, Denis; León, Verónica; Vázquez, Ester; Cellot, Giada; Privitera, Giulia; Lombardi, Lucia; Torrisi, Felice; Tomarchio, Flavia; Bonaccorso, Francesco; Bosi, Susanna; Ferrari, Andrea C; Ballerini, Laura; Prato, Maurizio

2016-01-26

Neural-interfaces rely on the ability of electrodes to transduce stimuli into electrical patterns delivered to the brain. In addition to sensitivity to the stimuli, stability in the operating conditions and efficient charge transfer to neurons, the electrodes should not alter the physiological properties of the target tissue. Graphene is emerging as a promising material for neuro-interfacing applications, given its outstanding physico-chemical properties. Here, we use graphene-based substrates (GBSs) to interface neuronal growth. We test our GBSs on brain cell cultures by measuring functional and synaptic integrity of the emerging neuronal networks. We show that GBSs are permissive interfaces, even when uncoated by cell adhesion layers, retaining unaltered neuronal signaling properties, thus being suitable for carbon-based neural prosthetic devices.

Does vector-free gravity simulate microgravity? Functional and morphologic attributes of clinorotated nerve and muscle grown in cell culture

NASA Technical Reports Server (NTRS)

Gruener, Raphael; Hoeger, Glenn

1988-01-01

Cocultured Xenopus neurons and myocytes were subjected to nonvectorial gravity by clinostat rotation to determine the effects of microgravity on cell development and communications. Observed effects included increases in the myocyte and its nuclear area, fragmentation of nucleoli, the appearance of neuritic aneurysms, decreased growth in the presence of trophic factors, and decreased yolk utilization. These effects were most notable at 1-10 rpm and depended on the onset and duration of rotation. It is found that, in microgravity, cell differentiation is altered by interference with cytoskeleton-related mechanisms. It is suggested that the alteration of the distribution of acetylcholine receptor aggregates on myocytes which occurs might indicate that microgravity affects brain development.

Altered blood-brain barrier transport in neuro-inflammatory disorders.

PubMed

Schenk, Geert J; de Vries, Helga E

2016-06-01

During neurodegenerative and neuroinflammatory disorders of the central nervous system (CNS), such as Alzheimer's disease (AD) and multiple sclerosis (MS), the protective function of the blood-brain barrier (BBB) may be severely impaired. The general neuro-inflammatory response, ranging from activation of glial cells to immune cell infiltration that is frequently associated with such brain diseases may underlie the loss of the integrity and function of the BBB. Consequentially, the delivery and disposition of drugs to the brain will be altered and may influence the treatment efficiency of such diseases. Altered BBB transport of drugs into the CNS during diseases may be the result of changes in both specific transport and non-specific transport pathways. Potential alterations in transport routes like adsorptive mediated endocytosis and receptor-mediated endocytosis may affect drug delivery to the brain. As such, drugs that normally are unable to traverse the BBB may reach their target in the diseased brain due to increased permeability. In contrast, the delivery of (targeted) drugs could be hampered during inflammatory conditions due to disturbed transport mechanisms. Therefore, the inventory of the neuro-inflammatory status of the neurovasculature (or recovery thereof) is of utmost importance in choosing and designing an adequate drug targeting strategy under disease conditions. Within this review we will briefly discuss how the function of the BBB can be affected during disease and how this may influence the delivery of drugs into the diseased CNS. Copyright © 2016 Elsevier Ltd. All rights reserved.

Self-organizing actin patterns shape membrane architecture but not cell mechanics

NASA Astrophysics Data System (ADS)

Fritzsche, M.; Li, D.; Colin-York, H.; Chang, V. T.; Moeendarbary, E.; Felce, J. H.; Sezgin, E.; Charras, G.; Betzig, E.; Eggeling, C.

2017-02-01

Cell-free studies have demonstrated how collective action of actin-associated proteins can organize actin filaments into dynamic patterns, such as vortices, asters and stars. Using complementary microscopic techniques, we here show evidence of such self-organization of the actin cortex in living HeLa cells. During cell adhesion, an active multistage process naturally leads to pattern transitions from actin vortices over stars into asters. This process is primarily driven by Arp2/3 complex nucleation, but not by myosin motors, which is in contrast to what has been theoretically predicted and observed in vitro. Concomitant measurements of mechanics and plasma membrane fluidity demonstrate that changes in actin patterning alter membrane architecture but occur functionally independent of macroscopic cortex elasticity. Consequently, tuning the activity of the Arp2/3 complex to alter filament assembly may thus be a mechanism allowing cells to adjust their membrane architecture without affecting their macroscopic mechanical properties.

Self-organizing actin patterns shape membrane architecture but not cell mechanics

PubMed Central

Fritzsche, M.; Li, D.; Colin-York, H.; Chang, V. T.; Moeendarbary, E.; Felce, J. H.; Sezgin, E.; Charras, G.; Betzig, E.; Eggeling, C.

2017-01-01

Cell-free studies have demonstrated how collective action of actin-associated proteins can organize actin filaments into dynamic patterns, such as vortices, asters and stars. Using complementary microscopic techniques, we here show evidence of such self-organization of the actin cortex in living HeLa cells. During cell adhesion, an active multistage process naturally leads to pattern transitions from actin vortices over stars into asters. This process is primarily driven by Arp2/3 complex nucleation, but not by myosin motors, which is in contrast to what has been theoretically predicted and observed in vitro. Concomitant measurements of mechanics and plasma membrane fluidity demonstrate that changes in actin patterning alter membrane architecture but occur functionally independent of macroscopic cortex elasticity. Consequently, tuning the activity of the Arp2/3 complex to alter filament assembly may thus be a mechanism allowing cells to adjust their membrane architecture without affecting their macroscopic mechanical properties. PMID:28194011

Genomic correlates of response to immune checkpoint therapies in clear cell renal cell carcinoma.

PubMed

Miao, Diana; Margolis, Claire A; Gao, Wenhua; Voss, Martin H; Li, Wei; Martini, Dylan J; Norton, Craig; Bossé, Dominick; Wankowicz, Stephanie M; Cullen, Dana; Horak, Christine; Wind-Rotolo, Megan; Tracy, Adam; Giannakis, Marios; Hodi, Frank Stephen; Drake, Charles G; Ball, Mark W; Allaf, Mohamad E; Snyder, Alexandra; Hellmann, Matthew D; Ho, Thai; Motzer, Robert J; Signoretti, Sabina; Kaelin, William G; Choueiri, Toni K; Van Allen, Eliezer M

2018-02-16

Immune checkpoint inhibitors targeting the programmed cell death 1 receptor (PD-1) improve survival in a subset of patients with clear cell renal cell carcinoma (ccRCC). To identify genomic alterations in ccRCC that correlate with response to anti-PD-1 monotherapy, we performed whole-exome sequencing of metastatic ccRCC from 35 patients. We found that clinical benefit was associated with loss-of-function mutations in the PBRM1 gene ( P = 0.012), which encodes a subunit of the PBAF switch-sucrose nonfermentable (SWI/SNF) chromatin remodeling complex. We confirmed this finding in an independent validation cohort of 63 ccRCC patients treated with PD-1 or PD-L1 (PD-1 ligand) blockade therapy alone or in combination with anti-CTLA-4 (cytotoxic T lymphocyte-associated protein 4) therapies ( P = 0.0071). Gene-expression analysis of PBAF-deficient ccRCC cell lines and PBRM1 -deficient tumors revealed altered transcriptional output in JAK-STAT (Janus kinase-signal transducers and activators of transcription), hypoxia, and immune signaling pathways. PBRM1 loss in ccRCC may alter global tumor-cell expression profiles to influence responsiveness to immune checkpoint therapy. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Differential signal pathway activation and 5-HT function: the role of gut enterochromaffin cells as oxygen sensors.

PubMed

Haugen, Martin; Dammen, Rikard; Svejda, Bernhard; Gustafsson, Bjorn I; Pfragner, Roswitha; Modlin, Irvin; Kidd, Mark

2012-11-15

The chemomechanosensory function of the gut enterochromaffin (EC) cell enables it to respond to dietary agents and mechanical stretch. We hypothesized that the EC cell, which also sensed alterations in luminal or mucosal oxygen level, was physiologically sensitive to fluctuations in O(2). Given that low oxygen levels induce 5-HT production and secretion through a hypoxia inducible factor 1α (HIF-1α)-dependent pathway, we also hypothesized that increasing O(2) would reduce 5-HT production and secretion. Isolated normal EC cells as well as the well-characterized EC cell model KRJ-I were used to examine HIF signaling (luciferase-assays), hypoxia transcriptional response element (HRE)-mediated transcription (PCR), signaling pathways (Western blot), and 5-HT release (ELISA) during exposure to different oxygen levels. Normal EC cells and KRJ-I cells express HIF-1α, and transient transfection with Renilla luciferase under HRE control identified a hypoxia-mediated pathway in these cells. PCR confirmed activation of HIF-downstream targets, GLUT1, IGF2, and VEGF under reduced O(2) levels (0.5%). Reducing O(2) also elevated 5-HT secretion (2-3.2-fold) as well as protein levels of HIF-1α (1.7-3-fold). Increasing O(2) to 100% inhibited HRE-mediated signaling, transcription, reduced 5-HT secretion, and significantly lowered HIF-1α levels (∼75% of control). NF-κB signaling was also elevated during hypoxia (1.2-1.6-fold), but no significant changes were noted in PKA/cAMP. We concluded that gut EC cells are oxygen responsive, and alterations in O(2) levels differentially activate HIF-1α and tryptophan hydroxylase 1, as well as NF-κB signaling. This results in alterations in 5-HT production and secretion and identifies that the chemomechanosensory role of EC cells extends to oxygen sensing.

Altered Natural Killer Cell Subsets in Seropositive Arthralgia and Early Rheumatoid Arthritis Are Associated with Autoantibody Status.

PubMed

Chalan, Paulina; Bijzet, Johan; Kroesen, Bart-Jan; Boots, Annemieke M H; Brouwer, Elisabeth

2016-06-01

The role of natural killer (NK) cells in the immunopathogenesis of rheumatoid arthritis (RA) is unclear. Therefore, numerical and functional alterations of CD56(dim) and CD56(bright) NK cells in the early stages of RA development were studied. Whole blood samples from newly diagnosed, treatment-naive, seropositive (SP) and seronegative (SN) patients with RA (SP RA, n = 45 and SN RA, n = 12), patients with SP arthralgia (n = 30), and healthy controls (HC, n = 41) were assessed for numbers and frequencies of T cells, B cells, and NK cells. SP status was defined as positive for anticyclic citrullinated peptide antibodies (anti-CCP) and/or rheumatoid factor (RF). Peripheral blood mononuclear cells were used for further analysis of NK cell phenotype and function. Total NK cell numbers were decreased in SP RA and SP arthralgia but not in SN RA. Also, NK cells from SP RA showed a decreased potency for interferon-γ (IFN-γ) production. A selective decrease of CD56(dim), but not CD56(bright), NK cells in SP RA and SP arthralgia was observed. This prompted investigation of CD16 (FcγRIIIa) triggering in NK cell apoptosis and cytokine expression. In vitro, CD16 triggering induced apoptosis of CD56(dim) but not CD56(bright) NK cells from HC. This apoptosis was augmented by adding interleukin 2 (IL-2). Also, CD16 triggering in the presence of IL-2 stimulated IFN-γ and tumor necrosis factor-α expression by CD56(dim) NK cells. The decline of CD56(dim) NK cells in SP arthralgia and SP RA and the in vitro apoptosis of CD56(dim) NK cells upon CD16 triggering suggest a functional role of immunoglobulin G-containing autoantibody (anti-CCP and/or RF)-immune complexes in this process. Moreover, CD16-triggered cytokine production by CD56(dim) NK cells may contribute to systemic inflammation as seen in SP arthralgia and SP RA.

Induction of autophagy by ARHI (DIRAS3) alters fundamental metabolic pathways in ovarian cancer models.

PubMed

Ornelas, Argentina; McCullough, Christopher R; Lu, Zhen; Zacharias, Niki M; Kelderhouse, Lindsay E; Gray, Joshua; Yang, Hailing; Engel, Brian J; Wang, Yan; Mao, Weiqun; Sutton, Margie N; Bhattacharya, Pratip K; Bast, Robert C; Millward, Steven W

2016-10-26

Autophagy is a bulk catabolic process that modulates tumorigenesis, therapeutic resistance, and dormancy. The tumor suppressor ARHI (DIRAS3) is a potent inducer of autophagy and its expression results in necroptotic cell death in vitro and tumor dormancy in vivo. ARHI is down-regulated or lost in over 60 % of primary ovarian tumors yet is dramatically up-regulated in metastatic disease. The metabolic changes that occur during ARHI induction and their role in modulating death and dormancy are unknown. We employed Nuclear Magnetic Resonance (NMR)-based metabolomic strategies to characterize changes in key metabolic pathways in both cell culture and xenograft models of ARHI expression and autophagy. These pathways were further interrogated by cell-based immunofluorescence imaging, tracer uptake studies, targeted metabolic inhibition, and in vivo PET/CT imaging. Induction of ARHI in cell culture models resulted in an autophagy-dependent increase in lactate production along with increased glucose uptake and enhanced sensitivity to glycolytic inhibitors. Increased uptake of glutamine was also dependent on autophagy and dramatically sensitized cultured ARHI-expressing ovarian cancer cell lines to glutaminase inhibition. Induction of ARHI resulted in a reduction in mitochondrial respiration, decreased mitochondrial membrane potential, and decreased Tom20 staining suggesting an ARHI-dependent loss of mitochondrial function. ARHI induction in mouse xenograft models resulted in an increase in free amino acids, a transient increase in [ 18 F]-FDG uptake, and significantly altered choline metabolism. ARHI expression has previously been shown to trigger autophagy-associated necroptosis in cell culture. In this study, we have demonstrated that ARHI expression results in decreased cellular ATP/ADP, increased oxidative stress, and decreased mitochondrial function. While this bioenergetic shock is consistent with programmed necrosis, our data indicates that the accompanying up-regulation of glycolysis and glutaminolysis is autophagy-dependent and serves to support cell viability rather than facilitate necroptotic cell death. While the mechanistic basis for metabolic up-regulation following ARHI induction is unknown, our preliminary data suggest that decreased mitochondrial function and increased metabolic demand may play a role. These alterations in fundamental metabolic pathways during autophagy-associated necroptosis may provide the basis for new therapeutic strategies for the treatment of dormant ovarian tumors.

Alteration in mitochondrial function and glutamate metabolism affected by 2-chloroethanol in primary cultured astrocytes.

PubMed

Sun, Qi; Liao, Yingjun; Wang, Tong; Wang, Gaoyang; Zhao, Fenghong; Jin, Yaping

2016-12-01

The aim of this study was to explore the mechanisms that contribute to 1,2-dichloroethane (1,2-DCE) induced brain edema by focusing on alteration of mitochondrial function and glutamate metabolism in primary cultured astrocytes induced by 2-chloroethanol (2-CE), a metabolite of 1,2-DCE in vivo. The cells were exposed to different levels of 2-CE in the media for 24h. Mitochondrial function was evaluated by its membrane potential and intracellular contents of ATP, lactic acid and reactive oxygen species (ROS). Glutamate metabolism was indicated by expression of glutamine synthase (GS), glutamate-aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1) at both protein and gene levels. Compared to the control group, exposure to 2-CE could cause a dose dependent damage in astrocytes, indicated by decreased cell viability and morphological changes, and supported by decreased levels of nonprotein sulfhydryl (NPSH) and inhibited activities of Na + /K + -ATPase and Ca 2+ -ATPase in the cells. The present study also revealed both mitochondrial function and glutamate metabolism in astrocytes were significantly disturbed by 2-CE. Of which, mitochondrial function was much vulnerable to the effects of 2-CE. In conclusion, our findings suggested that mitochondrial dysfunction and glutamate metabolism disorder could contribute to 2-CE-induced cytotoxicity in astrocytes, which might be related to 1,2-DCE-induced brain edema. Copyright © 2016 Elsevier Ltd. All rights reserved.

Age-related Deterioration of Hematopoietic Stem Cells.

PubMed

Kim, Mi Jung; Kim, Min Hwan; Kim, Seung Ah; Chang, Jae Suk

2008-11-01

Aging is the process of system deterioration over time in the whole body. Stem cells are self-renewing and therefore have been considered exempt from the aging process. Earlier studies by Hayflick showed that there is an intrinsic limit to the number of divisions that mammalian somatic cells can undergo, and cycling kinetics and ontogeny-related studies strongly suggest that even the most primitive stem cell functions exhibit a certain degree of aging. Despite these findings, studies on the effects of aging on stem cell functions are inconclusive. Here we review the age-related properties of hematopoietic stem cells in terms of intrinsic and extrinsic alterations, proliferative potential, signaling molecules, telomere and telomerase, senescence and cancer issues, regenerative potential and other indications of stem cell aging are discussed in detail.

Age-related Deterioration of Hematopoietic Stem Cells

PubMed Central

Kim, Mi Jung; Kim, Min Hwan; Kim, Seung Ah; Chang, Jae Suk

2008-01-01

Aging is the process of system deterioration over time in the whole body. Stem cells are self-renewing and therefore have been considered exempt from the aging process. Earlier studies by Hayflick showed that there is an intrinsic limit to the number of divisions that mammalian somatic cells can undergo, and cycling kinetics and ontogeny-related studies strongly suggest that even the most primitive stem cell functions exhibit a certain degree of aging. Despite these findings, studies on the effects of aging on stem cell functions are inconclusive. Here we review the age-related properties of hematopoietic stem cells in terms of intrinsic and extrinsic alterations, proliferative potential, signaling molecules, telomere and telomerase, senescence and cancer issues, regenerative potential and other indications of stem cell aging are discussed in detail. PMID:24855509

The mTOR signalling cascade: paving new roads to cure neurological disease.

PubMed

Crino, Peter B

2016-07-01

Defining the multiple roles of the mechanistic (formerly 'mammalian') target of rapamycin (mTOR) signalling pathway in neurological diseases has been an exciting and rapidly evolving story of bench-to-bedside translational research that has spanned gene mutation discovery, functional experimental validation of mutations, pharmacological pathway manipulation, and clinical trials. Alterations in the dual contributions of mTOR - regulation of cell growth and proliferation, as well as autophagy and cell death - have been found in developmental brain malformations, epilepsy, autism and intellectual disability, hypoxic-ischaemic and traumatic brain injuries, brain tumours, and neurodegenerative disorders. mTOR integrates a variety of cues, such as growth factor levels, oxygen levels, and nutrient and energy availability, to regulate protein synthesis and cell growth. In line with the positioning of mTOR as a pivotal cell signalling node, altered mTOR activation has been associated with a group of phenotypically diverse neurological disorders. To understand how altered mTOR signalling leads to such divergent phenotypes, we need insight into the differential effects of enhanced or diminished mTOR activation, the developmental context of these changes, and the cell type affected by altered signalling. A particularly exciting feature of the tale of mTOR discovery is that pharmacological mTOR inhibitors have shown clinical benefits in some neurological disorders, such as tuberous sclerosis complex, and are being considered for clinical trials in epilepsy, autism, dementia, traumatic brain injury, and stroke.

Quantitative Mass Spectrometry Reveals Changes in Histone H2B Variants as Cells Undergo Inorganic Arsenic-Mediated Cellular Transformation*

PubMed Central

Rea, Matthew; Jiang, Tingting; Eleazer, Rebekah; Eckstein, Meredith; Marshall, Alan G.; Fondufe-Mittendorf, Yvonne N.

2016-01-01

Exposure to inorganic arsenic, a ubiquitous environmental toxic metalloid, leads to carcinogenesis. However, the mechanism is unknown. Several studies have shown that inorganic arsenic exposure alters specific gene expression patterns, possibly through alterations in chromatin structure. While most studies on understanding the mechanism of chromatin-mediated gene regulation have focused on histone post-translational modifications, the role of histone variants remains largely unknown. Incorporation of histone variants alters the functional properties of chromatin. To understand the global dynamics of chromatin structure and function in arsenic-mediated carcinogenesis, analysis of the histone variants incorporated into the nucleosome and their covalent modifications is required. Here we report the first global mass spectrometric analysis of histone H2B variants as cells undergo arsenic-mediated epithelial to mesenchymal transition. We used electron capture dissociation-based top-down tandem mass spectrometry analysis validated with quantitative reverse transcription real-time polymerase chain reaction to identify changes in the expression levels of H2B variants in inorganic arsenic-mediated epithelial-mesenchymal transition. We identified changes in the expression levels of specific histone H2B variants in two cell types, which are dependent on dose and length of exposure of inorganic arsenic. In particular, we found increases in H2B variants H2B1H/1K/1C/1J/1O and H2B2E/2F, and significant decreases in H2B1N/1D/1B as cells undergo inorganic arsenic-mediated epithelial-mesenchymal transition. The analysis of these histone variants provides a first step toward an understanding of the functional significance of the diversity of histone structures, especially in inorganic arsenic-mediated gene expression and carcinogenesis. PMID:27169413

Ectopic Cdx2 Expression in Murine Esophagus Models an Intermediate Stage in the Emergence of Barrett's Esophagus

PubMed Central

Kong, Jianping; Crissey, Mary Ann; Funakoshi, Shinsuke; Kreindler, James L.; Lynch, John P.

2011-01-01

Barrett's esophagus (BE) is an intestinal metaplasia that occurs in the setting of chronic acid and bile reflux and is associated with a risk for adenocarcinoma. Expression of intestine-specific transcription factors in the esophagus likely contributes to metaplasia development. Our objective was to explore the effects of an intestine-specific transcription factor when expressed in the mouse esophageal epithelium. Transgenic mice were derived in which the transcription factor Cdx2 is expressed in squamous epithelium using the murine Keratin-14 gene promoter. Effects of the transgene upon cell proliferation and differentiation, gene expression, and barrier integrity were explored. K14-Cdx2 mice express the Cdx2 transgene in esophageal squamous tissues. Cdx2 expression was associated with reduced basal epithelial cell proliferation and altered cell morphology. Ultrastructurally two changes were noted. Cdx2 expression was associated with dilated space between the basal cells and diminished cell-cell adhesion caused by reduced Desmocollin-3 mRNA and protein expression. This compromised epithelial barrier function, as the measured trans-epithelial electrical resistance (TEER) of the K14-Cdx2 epithelium was significantly reduced compared to controls (1189 Ohm*cm2 ±343.5 to 508 Ohm*cm2±92.48, p = 0.0532). Secondly, basal cells with features of a transitional cell type, intermediate between keratinocytes and columnar Barrett's epithelial cells, were observed. These cells had reduced keratin bundles and increased endoplasmic reticulum levels, suggesting the adoption of secretory-cell features. Moreover, at the ultrastructural level they resembled “Distinctive” cells associated with multilayered epithelium. Treatment of the K14-Cdx2 mice with 5′-Azacytidine elicited expression of BE-associated genes including Cdx1, Krt18, and Slc26a3/Dra, suggesting the phenotype could be advanced under certain conditions. We conclude that ectopic Cdx2 expression in keratinocytes alters cell proliferation, barrier function, and differentiation. These altered cells represent a transitional cell type between normal squamous and columnar BE cells. The K14-Cdx2 mice represent a useful model to study progression from squamous epithelium to BE. PMID:21494671

Ectopic Cdx2 expression in murine esophagus models an intermediate stage in the emergence of Barrett's esophagus.

PubMed

Kong, Jianping; Crissey, Mary Ann; Funakoshi, Shinsuke; Kreindler, James L; Lynch, John P

2011-04-06

Barrett's esophagus (BE) is an intestinal metaplasia that occurs in the setting of chronic acid and bile reflux and is associated with a risk for adenocarcinoma. Expression of intestine-specific transcription factors in the esophagus likely contributes to metaplasia development. Our objective was to explore the effects of an intestine-specific transcription factor when expressed in the mouse esophageal epithelium. Transgenic mice were derived in which the transcription factor Cdx2 is expressed in squamous epithelium using the murine Keratin-14 gene promoter. Effects of the transgene upon cell proliferation and differentiation, gene expression, and barrier integrity were explored. K14-Cdx2 mice express the Cdx2 transgene in esophageal squamous tissues. Cdx2 expression was associated with reduced basal epithelial cell proliferation and altered cell morphology. Ultrastructurally two changes were noted. Cdx2 expression was associated with dilated space between the basal cells and diminished cell-cell adhesion caused by reduced Desmocollin-3 mRNA and protein expression. This compromised epithelial barrier function, as the measured trans-epithelial electrical resistance (TEER) of the K14-Cdx2 epithelium was significantly reduced compared to controls (1189 Ohm*cm(2) ±343.5 to 508 Ohm*cm(2)±92.48, p = 0.0532). Secondly, basal cells with features of a transitional cell type, intermediate between keratinocytes and columnar Barrett's epithelial cells, were observed. These cells had reduced keratin bundles and increased endoplasmic reticulum levels, suggesting the adoption of secretory-cell features. Moreover, at the ultrastructural level they resembled "Distinctive" cells associated with multilayered epithelium. Treatment of the K14-Cdx2 mice with 5'-Azacytidine elicited expression of BE-associated genes including Cdx1, Krt18, and Slc26a3/Dra, suggesting the phenotype could be advanced under certain conditions. We conclude that ectopic Cdx2 expression in keratinocytes alters cell proliferation, barrier function, and differentiation. These altered cells represent a transitional cell type between normal squamous and columnar BE cells. The K14-Cdx2 mice represent a useful model to study progression from squamous epithelium to BE.

Aging, metabolism and stem cells: Spotlight on muscle stem cells.

PubMed

García-Prat, Laura; Muñoz-Cánoves, Pura

2017-04-15

All tissues and organs undergo a progressive regenerative decline as they age. This decline has been mainly attributed to loss of stem cell number and/or function, and both stem cell-intrinsic changes and alterations in local niches and/or systemic environment over time are known to contribute to the stem cell aging phenotype. Advancing in the molecular understanding of the deterioration of stem cell cells with aging is key for targeting the specific causes of tissue regenerative dysfunction at advanced stages of life. Here, we revise exciting recent findings on why stem cells age and the consequences on tissue regeneration, with a special focus on regeneration of skeletal muscle. We also highlight newly identified common molecular pathways affecting diverse types of aging stem cells, such as altered proteostasis, metabolism, or senescence entry, and discuss the questions raised by these findings. Finally, we comment on emerging stem cell rejuvenation strategies, principally emanating from studies on muscle stem cells, which will surely burst tissue regeneration research for future benefit of the increasing human aging population. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Human NK Cell Subset Functions Are Differentially Affected by Adipokines

PubMed Central

Huebner, Lena; Engeli, Stefan; Wrann, Christiane D.; Goudeva, Lilia; Laue, Tobias; Kielstein, Heike

2013-01-01

Background Obesity is a risk factor for various types of infectious diseases and cancer. The increase in adipose tissue causes alterations in both adipogenesis and the production of adipocyte-secreted proteins (adipokines). Since natural killer (NK) cells are the host’s primary defense against virus-infected and tumor cells, we investigated how adipocyte-conditioned medium (ACM) affects functions of two distinct human NK cell subsets. Methods Isolated human peripheral blood mononuclear cells (PBMCs) were cultured with various concentrations of human and murine ACM harvested on two different days during adipogenesis and analyzed by fluorescent-activated cell sorting (FACS). Results FACS analyses showed that the expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), granzyme A (GzmA) and interferon (IFN)-γ in NK cells was regulated in a subset-specific manner. ACM treatment altered IFN-γ expression in CD56dim NK cells. The production of GzmA in CD56bright NK cells was differentially affected by the distinct adipokine compositions harvested at different states of adipogenesis. Comparison of the treatment with either human or murine ACM revealed that adipokine-induced effects on NK cell expression of the leptin receptor (Ob-R), TRAIL and IFN-γ were species-specific. Conclusion Considering the growing prevalence of obesity and the various disorders related to it, the present study provides further insights into the roles human NK cell subsets play in the obesity-associated state of chronic low-grade inflammation. PMID:24098717

Altered distribution and function of natural killer cells in murine and human Niemann-Pick disease type C1

PubMed Central

Speak, Anneliese O.; te Vruchte, Danielle; Davis, Lianne C.; Morgan, Anthony J.; Smith, David A.; Yanjanin, Nicole M.; Simmons, Louise; Hartung, Ralf; Runz, Heiko; Mengel, Eugen; Beck, Michael; Imrie, Jackie; Jacklin, Elizabeth; Wraith, James E.; Hendriksz, Christian; Lachmann, Robin; Cognet, Celine; Sidhu, Rohini; Fujiwara, Hideji; Ory, Daniel S.; Galione, Antony; Porter, Forbes D.; Vivier, Eric

2014-01-01

Niemann-Pick type C (NPC) is a neurodegenerative lysosomal storage disorder caused by defects in the lysosomal proteins NPC1 or NPC2. NPC cells are characterized by reduced lysosomal calcium levels and impaired sphingosine transport from lysosomes. Natural killer (NK) cells kill virally infected/transformed cells via degranulation of lysosome-related organelles. Their trafficking from lymphoid tissues into the circulation is dependent on sphingosine-1-phosphate (S1P) gradients, sensed by S1P receptor 5 (S1P5). We hypothesized that NK-cell function and trafficking could be affected in NPC disease due to the combined effects of the lysosomal calcium defect and sphingosine storage. In an NPC1 mouse model, we found the frequency of NK cells was altered and phenocopied S1P5-deficient mice, consistent with defects in S1P levels. NK cells from NPC1 mice also had a defect in cytotoxicity due to a failure in degranulation of cytotoxic granules, which was associated with reduced lysosomal calcium levels. Affected NPC1 patients and NPC1 heterozygote carriers had reduced NK-cell numbers in their blood and showed similar phenotypic and developmental changes to those observed in the NPC1 mouse. These findings highlight the effects of lysosomal storage on the peripheral immune system. PMID:24235134

PHF6 regulates phenotypic plasticity through chromatin organization within lineage-specific genes.

PubMed

Soto-Feliciano, Yadira M; Bartlebaugh, Jordan M E; Liu, Yunpeng; Sánchez-Rivera, Francisco J; Bhutkar, Arjun; Weintraub, Abraham S; Buenrostro, Jason D; Cheng, Christine S; Regev, Aviv; Jacks, Tyler E; Young, Richard A; Hemann, Michael T

2017-05-15

Developmental and lineage plasticity have been observed in numerous malignancies and have been correlated with tumor progression and drug resistance. However, little is known about the molecular mechanisms that enable such plasticity to occur. Here, we describe the function of the plant homeodomain finger protein 6 (PHF6) in leukemia and define its role in regulating chromatin accessibility to lineage-specific transcription factors. We show that loss of Phf6 in B-cell leukemia results in systematic changes in gene expression via alteration of the chromatin landscape at the transcriptional start sites of B-cell- and T-cell-specific factors. Additionally, Phf6 KO cells show significant down-regulation of genes involved in the development and function of normal B cells, show up-regulation of genes involved in T-cell signaling, and give rise to mixed-lineage lymphoma in vivo. Engagement of divergent transcriptional programs results in phenotypic plasticity that leads to altered disease presentation in vivo, tolerance of aberrant oncogenic signaling, and differential sensitivity to frontline and targeted therapies. These findings suggest that active maintenance of a precise chromatin landscape is essential for sustaining proper leukemia cell identity and that loss of a single factor (PHF6) can cause focal changes in chromatin accessibility and nucleosome positioning that render cells susceptible to lineage transition. © 2017 Soto-Feliciano et al.; Published by Cold Spring Harbor Laboratory Press.

Local suppression of contact hypersensitivity in mice by a new bifunctional psoralen, 4,4',5'-trimethylazapsoralen, and UVA radiation.

PubMed

Aubin, F; Dall'Acqua, F; Kripke, M L

1991-07-01

Although psoralens plus UVA radiation (320-400 nm) have been widely used for the treatment of dermatologic diseases, the toxic effects of these agents have led investigators to develop new photochemotherapeutic compounds. One such compound is 4,4',5'-trimethylazapsoralen (TMAP), a new bifunctional molecule. The purpose of this study was to examine the immunologic side effects of repeated treatment of C3H mice with TMAP plus UVA radiation. During this treatment, the number of ATPase+, la+, and Thy-1+ dendritic epidermal cells greatly decreased in the treated site, despite the lack of phototoxicity. The reduction in the number of detectable cutaneous immune cells was accompanied by a decrease in the induction of contact hypersensitivity to dinitrofluorobenzene applied to the treated skin, an impairment in the antigen-presenting activity of draining lymph node cells, and the presence of suppressor lymphoid cells in the spleen of unresponsive mice. Treatment with UVA radiation alone also reduced the number of ATPase+, Ia+, and Thy-1+ cells in the skin, but did not cause any detectable alterations in immune function. This implies that morphologic alterations in these cells do not necessarily indicate loss of function. Thus, although TMAP in combination with UVA radiation is not overtly phototoxic, it is highly immunosuppressive in mice.

Vorinostat differentially alters 3D nuclear structure of cancer and non-cancerous esophageal cells.

PubMed

Nandakumar, Vivek; Hansen, Nanna; Glenn, Honor L; Han, Jessica H; Helland, Stephanie; Hernandez, Kathryn; Senechal, Patti; Johnson, Roger H; Bussey, Kimberly J; Meldrum, Deirdre R

2016-08-09

The histone deacetylase (HDAC) inhibitor vorinostat has received significant attention in recent years as an 'epigenetic' drug used to treat solid tumors. However, its mechanisms of action are not entirely understood, particularly with regard to its interaction with the aberrations in 3D nuclear structure that accompany neoplastic progression. We investigated the impact of vorinostat on human esophageal epithelial cell lines derived from normal, metaplastic (pre-cancerous), and malignant tissue. Using a combination of novel optical computed tomography (CT)-based quantitative 3D absorption microscopy and conventional confocal fluorescence microscopy, we show that subjecting malignant cells to vorinostat preferentially alters their 3D nuclear architecture relative to non-cancerous cells. Optical CT (cell CT) imaging of fixed single cells showed that drug-treated cancer cells exhibit significant alterations in nuclear morphometry. Confocal microscopy revealed that vorinostat caused changes in the distribution of H3K9ac-marked euchromatin and H3K9me3-marked constitutive heterochromatin. Additionally, 3D immuno-FISH showed that drug-induced expression of the DNA repair gene MGMT was accompanied by spatial relocation toward the center of the nucleus in the nuclei of metaplastic but not in non-neoplastic cells. Our data suggest that vorinostat's differential modulation of 3D nuclear architecture in normal and abnormal cells could play a functional role in its anti-cancer action.

Exploiting the Gastric Epithelial Barrier: Helicobacter pylori's Attack on Tight and Adherens Junctions.

PubMed

Backert, Steffen; Schmidt, Thomas P; Harrer, Aileen; Wessler, Silja

2017-01-01

Highly organized intercellular tight and adherens junctions are crucial structural components for establishing and maintenance of epithelial barrier functions, which control the microbiota and protect against intruding pathogens in humans. Alterations in these complexes represent key events in the development and progression of multiple infectious diseases as well as various cancers. The gastric pathogen Helicobacter pylori exerts an amazing set of strategies to manipulate these epithelial cell-to-cell junctions, which are implicated in changing cell polarity, migration and invasive growth as well as pro-inflammatory and proliferative responses. This chapter focuses on the H. pylori pathogenicity factors VacA, CagA, HtrA and urease, and how they can induce host cell signaling involved in altering cell-to-cell permeability. We propose a stepwise model for how H. pylori targets components of tight and adherens junctions in order to disrupt the gastric epithelial cell layer, giving fresh insights into the pathogenesis of this important bacterium.

Altered Exocytosis in Chromaffin Cells from Mouse Models of Neurodegenerative Diseases.

PubMed

de Diego, Antonio M G; García, Antonio G

2018-05-09

Chromaffin cells from the adrenal gland (CCs) have extensively been used to explore the molecular structure and function of the exocytotic machinery, neurotransmitter release and synaptic transmission. The CC is integrated in the sympathoadrenal axis that helps the body maintain homeostasis during both routine life and in acute stress conditions. This function is exquisitely controlled by the cerebral cortex and the hypothalamus. We propose the hypothesis that damage undergone by the brain during neurodegenerative diseases is also affecting the neurosecretory function of adrenal medullary CCs. In this context we review here the following themes: (i) how the discharge of catecholamines is centrally and peripherally regulated at the sympatho-adrenal axis; (ii) which are the intricacies of the amperometric techniques used to study the quantal release of single-vesicle exocytotic events; (iii) which are the alterations of the exocytotic fusion pore so far reported, in CCs of mouse models of neurodegenerative diseases; (iv) how some proteins linked to neurodegenerative pathologies affects the kinetics of exocytotic events; (v) finally we try to integrate available data into a hypothesis to explain how the centrally originated neurodegenerative diseases may alter the kinetics of single-vesicle exocytotic events in peripheral adrenal medullary CCs. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Versatile functional roles of horizontal cells in the retinal circuit.

PubMed

Chaya, Taro; Matsumoto, Akihiro; Sugita, Yuko; Watanabe, Satoshi; Kuwahara, Ryusuke; Tachibana, Masao; Furukawa, Takahisa

2017-07-17

In the retinal circuit, environmental light signals are converted into electrical signals that can be decoded properly by the brain. At the first synapse of the visual system, information flow from photoreceptors to bipolar cells is modulated by horizontal cells (HCs), however, their functional contribution to retinal output and individual visual function is not fully understood. In the current study, we investigated functional roles for HCs in retinal ganglion cell (RGC) response properties and optokinetic responses by establishing a HC-depleted mouse line. We observed that HC depletion impairs the antagonistic center-surround receptive field formation of RGCs, supporting a previously reported HC function revealed by pharmacological approaches. In addition, we found that HC loss reduces both the ON and OFF response diversities of RGCs, impairs adjustment of the sensitivity to ambient light at the retinal output level, and alters spatial frequency tuning at an individual level. Taken together, our current study suggests multiple functional aspects of HCs crucial for visual processing.

Overexpression of neurofilament H disrupts normal cell structure and function

NASA Technical Reports Server (NTRS)

Szebenyi, Gyorgyi; Smith, George M.; Li, Ping; Brady, Scott T.

2002-01-01

Studying exogenously expressed tagged proteins in live cells has become a standard technique for evaluating protein distribution and function. Typically, expression levels of experimentally introduced proteins are not regulated, and high levels are often preferred to facilitate detection. However, overexpression of many proteins leads to mislocalization and pathologies. Therefore, for normative studies, moderate levels of expression may be more suitable. To understand better the dynamics of intermediate filament formation, transport, and stability in a healthy, living cell, we inserted neurofilament heavy chain (NFH)-green fluorescent protein (GFP) fusion constructs in adenoviral vectors with tetracycline (tet)-regulated promoters. This system allows for turning on or off the synthesis of NFH-GFP at a selected time, for a defined period, in a dose-dependent manner. We used this inducible system for live cell imaging of changes in filament structure and cell shape, motility, and transport associated with increasing NFH-GFP expression. Cells with low to intermediate levels of NFH-GFP were structurally and functionally similar to neighboring, nonexpressing cells. In contrast, overexpression led to pathological alterations in both filament organization and cell function. Copyright 2002 Wiley-Liss, Inc.

Biochemical and Functional Interactions of Human Papillomavirus Proteins with Polycomb Group Proteins

PubMed Central

McLaughlin-Drubin, Margaret E.; Munger, Karl

2013-01-01

The role of enzymes involved in polycomb repression of gene transcription has been studied extensively in human cancer. Polycomb repressive complexes mediate oncogene-induced senescence, a principal innate cell-intrinsic tumor suppressor pathway that thwarts expansion of cells that have suffered oncogenic hits. Infections with human cancer viruses including human papillomaviruses (HPVs) and Epstein-Barr virus can trigger oncogene-induced senescence, and the viruses have evolved strategies to abrogate this response in order to establish an infection and reprogram their host cells to establish a long-term persistent infection. As a consequence of inhibiting polycomb repression and evading oncogene induced-senescence, HPV infected cells have an altered epigenetic program as evidenced by aberrant homeobox gene expression. Similar alterations are frequently observed in non-virus associated human cancers and may be harnessed for diagnosis and therapy. PMID:23673719

Nandrolone decreases mu opioid receptor expression in SH-SY5Y human neuroblastoma cells.

PubMed

Guarino, Goffredo; Spampinato, Santi

2008-07-16

Nandrolone and other anabolic androgenic steroids alter the expression and function of neurotransmitter systems and contribute to drug dependence. Nandrolone treatment (10-10 M) caused a time-dependent and concentration-dependent downregulation of mu opioid receptor (MOPr) transcripts in SH-SY5Y human neuroblastoma cells. This effect was prevented by the androgen receptor antagonist hydroxyflutamide. Receptor binding assays confirmed a decrease in MOPr of approximately 40% in nandrolone-treated cells. Treatment with actinomycin D (10 (-5)M), a transcription inhibitor, revealed that nandrolone might regulate MOPr mRNA stability. In SH-SY5Y cells transfected with a human MOPr luciferase promoter/reporter construct, nandrolone did not alter the rate of gene transcription. These results suggest that nandrolone may regulate MOPr expression through posttranscriptional mechanisms requiring the androgen receptor.

Clinical indices of in vivo biocompatibility: the role of ex vivo cell function studies and effluent markers in peritoneal dialysis patients.

PubMed

Mackenzie, Ruth; Holmes, Clifford J; Jones, Suzanne; Williams, John D; Topley, Nicholas

2003-12-01

Clinical indices of in vivo biocompatibility: The role of ex vivo cell function studies and effluent markers in peritoneal dialysis patients. Over the past 20 years, studies of the biocompatibility profile of peritoneal dialysis solutions (PDF) have evolved from initial in vitro studies assessing the impact of solutions on leukocyte function to evaluations of mesothelial cell behavior. More recent biocompatibility evaluations have involved assessments of the impact of PDF on membrane integrity and cell function in peritoneal dialysis (PD) patients. The development of ex vivo systems for the evaluation of in vivo cell function, and effluent markers of membrane integrity and inflammation in patients exposed both acutely and chronically to conventional and new PDF will be interpreted in the context of our current understanding of the biology of the dialyzed peritoneum. The available data indicate that exposure of the peritoneal environment to more biocompatible PDF is associated with improvements in peritoneal cell function, alterations in markers of membrane integrity, and reduced local inflammation. These data suggest that more biocompatible PDF will have a positive impact on host defense, peritoneal homeostasis, and the long-term preservation of peritoneal membrane function in PD patients.

Advanced glycation endproducts alter functions and promote apoptosis in endothelial progenitor cells through receptor for advanced glycation endproducts mediate overpression of cell oxidant stress.

PubMed

Chen, Jianfei; Song, Minbao; Yu, Shiyong; Gao, Pan; Yu, Yang; Wang, Hong; Huang, Lan

2010-02-01

Endothelial progenitor cells (EPCs) play an important role in preventing atherosclerosis. The factors that regulate the function of EPCs are not completely clear. Increased formation of advanced glycation endproducts (AGEs) is generally regarded as one of the main mechanisms responsible for vascular damage in patients with diabetes and atherosclerosis. AGEs lead to the generation of reactive oxygen species (ROS) and part of the regenerative capacity of EPCs seems to be due to their low baseline ROS levels and reduced sensitivity to ROS-induced cell apoptosis. Therefore, we tested the hypothesis that AGEs can alter functions and promote apoptosis in EPCs through overpress cell oxidant stress. EPCs, isolated from bone marrow, were cultured in the absence or presence of AGEs (50, 100, and 200 microg/ml). A modified Boyden's chamber was used to assess the migration of EPCs and the number of recultured EPCs was counted to measure the adhesiveness function. MTT assay was used to determine the proliferation function. ROS were analyzed using the ROS assay kit. A spectrophotometer was used to assess superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activity, and PCR was used to test mRNA expression of SOD and GSH-PX. SiRNA was used to block receptor for advanced glycation endproducts (RAGEs) expression. Apoptosis was evaluated by Annexin V immunostaining and TUNEL staining. Co-culturing with AGEs increases ROS production, decreases anti-oxidant defenses, overpresses oxidant stress, inhibits the proliferation, migration, and adhesion of EPCs, and induces EPCs apoptosis. In addition, these effects were attenuated during block RAGE protein expression by siRNA. AGEs may serve to impair EPCs functions through RAGE-mediate oxidant stress, and promote EPCs sensitivity toward oxidative-stress-mediated apoptosis, which indicates a new pathophysiological mechanism of disturbed vascular adaptation in atherosclerosis and suggests that lower levels of AGEs might improve the success of progenitor cell therapy.

Molecular alterations in tumorigenic human bronchial and breast epithelial cells induced by high let radiation

NASA Astrophysics Data System (ADS)

Hei, T. K.; Zhao, Y. L.; Roy, D.; Piao, C. Q.; Calaf, G.; Hall, E. J.

Carcinogenesis is a multi-stage process with sequence of genetic events governing the phenotypic expression of a series of transformation steps leading to the development of metastatic cancer. In the present study, immortalized human bronchial (BEP2D) and breast (MCF-10F) cells were irradiated with graded doses of either 150 keV/μm alpha particles or 1 GeV/nucleon 56Fe ions. Transformed cells developed through a series of successive steps before becoming tumorigenic in nude mice. Cell fusion studies indicated that radiation-induced tumorigenic phenotype in BEP2D cells could be completely suppressed by fusion with non-tumorigenic BEP2D cells. The differential expressions of known genes between tumorigenic bronchial and breast cells induced by alpha particles and their respective control cultures were compared using cDNA expression array. Among the 11 genes identified to be differentially expressed in BEP2D cells, three ( DCC, DNA-PK and p21 CIPI) were shown to be consistently down-regulated by 2 to 4 fold in all the 5 tumor cell lines examined. In contrast, their expressions in the fusion cell lines were comparable to control BEP2D cells. Similarly, expression levels of a series of genes were found to be altered in a step-wise manner among tumorigenic MCF-10F cells. The results are highly suggestive that functional alterations of these genes may be causally related to the carcinogenic process.

The First Scube3 Mutant Mouse Line with Pleiotropic Phenotypic Alterations

PubMed Central

Fuchs, Helmut; Sabrautzki, Sibylle; Przemeck, Gerhard K. H.; Leuchtenberger, Stefanie; Lorenz-Depiereux, Bettina; Becker, Lore; Rathkolb, Birgit; Horsch, Marion; Garrett, Lillian; Östereicher, Manuela A.; Hans, Wolfgang; Abe, Koichiro; Sagawa, Nobuho; Rozman, Jan; Vargas-Panesso, Ingrid L.; Sandholzer, Michael; Lisse, Thomas S.; Adler, Thure; Aguilar-Pimentel, Juan Antonio; Calzada-Wack, Julia; Ehrhard, Nicole; Elvert, Ralf; Gau, Christine; Hölter, Sabine M.; Micklich, Katja; Moreth, Kristin; Prehn, Cornelia; Puk, Oliver; Racz, Ildiko; Stoeger, Claudia; Vernaleken, Alexandra; Michel, Dian; Diener, Susanne; Wieland, Thomas; Adamski, Jerzy; Bekeredjian, Raffi; Busch, Dirk H.; Favor, John; Graw, Jochen; Klingenspor, Martin; Lengger, Christoph; Maier, Holger; Neff, Frauke; Ollert, Markus; Stoeger, Tobias; Yildirim, Ali Önder; Strom, Tim M.; Zimmer, Andreas; Wolf, Eckhard; Wurst, Wolfgang; Klopstock, Thomas; Beckers, Johannes; Gailus-Durner, Valerie; Hrabé de Angelis, Martin

2016-01-01

The vertebrate Scube (Signal peptide, CUB, and EGF-like domain-containing protein) family consists of three independent members, Scube1–3, which encode secreted cell surface-associated membrane glycoproteins. Limited information about the general function of this gene family is available, and their roles during adulthood. Here, we present the first Scube3 mutant mouse line (Scube3N294K/N294K), which clearly shows phenotypic alterations by carrying a missense mutation in exon 8, and thus contributes to our understanding of SCUBE3 functions. We performed a detailed phenotypic characterization in the German Mouse Clinic (GMC). Scube3N294K/N294K mutants showed morphological abnormalities of the skeleton, alterations of parameters relevant for bone metabolism, changes in renal function, and hearing impairments. These findings correlate with characteristics of the rare metabolic bone disorder Paget disease of bone (PDB), associated with the chromosomal region of human SCUBE3. In addition, alterations in energy metabolism, behavior, and neurological functions were detected in Scube3N294K/N294K mice. The Scube3N294K/N294K mutant mouse line may serve as a new model for further studying the effect of impaired SCUBE3 gene function. PMID:27815347

CNC-bZIP protein Nrf1-dependent regulation of glucose-stimulated insulin secretion.

PubMed

Zheng, Hongzhi; Fu, Jingqi; Xue, Peng; Zhao, Rui; Dong, Jian; Liu, Dianxin; Yamamoto, Masayuki; Tong, Qingchun; Teng, Weiping; Qu, Weidong; Zhang, Qiang; Andersen, Melvin E; Pi, Jingbo

2015-04-01

The inability of pancreatic β-cells to secrete sufficient insulin in response to glucose stimulation is a major contributing factor to the development of type 2 diabetes (T2D). We investigated both the in vitro and in vivo effects of deficiency of nuclear factor-erythroid 2-related factor 1 (Nrf1) in β-cells on β-cell function and glucose homeostasis. Silencing of Nrf1 in β-cells leads to a pre-T2D phenotype with disrupted glucose metabolism and impaired insulin secretion. Specifically, MIN6 β-cells with stable knockdown of Nrf1 (Nrf1-KD) and isolated islets from β-cell-specific Nrf1-knockout [Nrf1(b)-KO] mice displayed impaired glucose responsiveness, including elevated basal insulin release and decreased glucose-stimulated insulin secretion (GSIS). Nrf1(b)-KO mice exhibited severe fasting hyperinsulinemia, reduced GSIS, and glucose intolerance. Silencing of Nrf1 in MIN6 cells resulted in oxidative stress and altered glucose metabolism, with increases in both glucose uptake and aerobic glycolysis, which is associated with the elevated basal insulin release and reduced glucose responsiveness. The elevated glycolysis and reduced glucose responsiveness due to Nrf1 silencing likely result from altered expression of glucose metabolic enzymes, with induction of high-affinity hexokinase 1 and suppression of low-affinity glucokinase. Our study demonstrated a novel role of Nrf1 in regulating glucose metabolism and insulin secretion in β-cells and characterized Nrf1 as a key transcription factor that regulates the coupling of glycolysis and mitochondrial metabolism and GSIS. Nrf1 plays critical roles in regulating glucose metabolism, mitochondrial function, and insulin secretion, suggesting that Nrf1 may be a novel target to improve the function of insulin-secreting β-cells.

Immune System Dysregulation, Viral Reactivation and Stress During Short-Duration Spaceflight

NASA Technical Reports Server (NTRS)

Pierson, Duane; Sams, Clarence; Crucian, Brian; Mehta, Satish; Stowe, Raymond; Uchakin, Peter; Quiriarte, Heather

2010-01-01

The objective of this NASA Short-Duration Bioastronautics Investigation (SDBI) was to assess spaceflight-associated immune dysregulation. Many previous studies have investigated this phenomenon post-flight, and found altered distribution and function of the peripheral leukocyte populations. Alterations in cytokine production profiles have also been reported. Unfortunately, post-flight data may be altered by the stress associated with high-G re-entry and readaptation to unit gravity following deconditioning. Therefore, the current study collected blood and saliva samples from crewmembers immediately before landing, and returned those samples to Earth for terrestrial analysis. Assays include peripheral comprehensive immunophenotype, T cell function, cytokine profiles, viral-specific immunity, latent viral reactivation (EBV, CMV, VZV), and stress hormone measurements. A total of 18 short duration crewmembers completed the study and the final data will be presented.

Carcinoembryonic antigen promotes colorectal cancer progression by targeting adherens junction complexes

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

Bajenova, Olga, E-mail: o.bazhenova@spbu.ru; Department of Genetics and Biotechnology, St. Petersburg State University, St. Petersburg 199034; Department of Surgery and Biomedical Sciences, Creighton University, Omaha, NE 68178

2014-06-10

Oncomarkers play important roles in the detection and management of human malignancies. Carcinoembryonic antigen (CEA, CEACAM5) and epithelial cadherin (E-cadherin) are considered as independent tumor markers in monitoring metastatic colorectal cancer. They are both expressed by cancer cells and can be detected in the blood serum. We investigated the effect of CEA production by MIP101 colorectal carcinoma cell lines on E-cadherin adherens junction (AJ) protein complexes. No direct interaction between E-cadherin and CEA was detected; however, the functional relationships between E-cadherin and its AJ partners: α-, β- and p120 catenins were impaired. We discovered a novel interaction between CEA andmore » beta-catenin protein in the CEA producing cells. It is shown in the current study that CEA overexpression alters the splicing of p120 catenin and triggers the release of soluble E-cadherin. The influence of CEA production by colorectal cancer cells on the function of E-cadherin junction complexes may explain the link between the elevated levels of CEA and the increase in soluble E-cadherin during the progression of colorectal cancer. - Highlights: • Elevated level of CEA increases the release of soluble E-cadherin during the progression of colorectal cancer. • CEA over-expression alters the binding preferences between E-cadherin and its partners: α-, β- and p120 catenins in adherens junction complexes. • CEA produced by colorectal cancer cells interacts with beta-catenin protein. • CEA over-expression triggers the increase in nuclear beta-catenin. • CEA over-expression alters the splicing of p120 catenin protein.« less

Efficacy of BET bromodomain inhibition in Kras-mutant non-small cell lung cancer

PubMed Central

Shimamura, Takeshi; Chen, Zhao; Soucheray, Margaret; Carretero, Julian; Kikuchi, Eiki; Tchaicha, Jeremy H.; Gao, Yandi; Cheng, Katherine A.; Cohoon, Travis J.; Qi, Jun; Akbay, Esra; Kimmelman, Alec C.; Kung, Andrew L.; Bradner, James E.; Wong, Kwok-Kin

2013-01-01

Purpose Amplification of MYC is one of the most common genetic alterations in lung cancer, contributing to a myriad of phenotypes associated with growth, invasion and drug resistance. Murine genetics has established both the centrality of somatic alterations of Kras in lung cancer, as well as the dependency of mutant Kras tumors on MYC function. Unfortunately, drug-like small-molecule inhibitors of KRAS and MYC have yet to be realized. The recent discovery, in hematologic malignancies, that BET bromodomain inhibition impairs MYC expression and MYC transcriptional function established the rationale of targeting KRAS-driven NSCLC with BET inhibition. Experimental Design We performed functional assays to evaluate the effects of JQ1 in genetically defined NSCLC cells lines harboring KRAS and/or LKB1 mutations. Furthermore, we evaluated JQ1 in transgenic mouse lung cancer models expressing mutant kras or concurrent mutant kras and lkb1. Effects of bromodomain inhibition on transcriptional pathways were explored and validated by expression analysis. Results While JQ1 is broadly active in NSCLC cells, activity of JQ1 in mutant KRAS NSCLC is abrogated by concurrent alteration or genetic knock-down of LKB1. In sensitive NSCLC models, JQ1 treatment results in the coordinate downregulation of the MYC-dependent transcriptional program. We found that JQ1 treatment produces significant tumor regression in mutant kras mice. As predicted, tumors from mutant kras and lkb1 mice did not respond to JQ1. Conclusion Bromodomain inhibition comprises a promising therapeutic strategy for KRAS mutant NSCLC with wild-type LKB1, via inhibition of MYC function. Clinical studies of BET bromodomain inhibitors in aggressive NSCLC will be actively pursued. PMID:24045185

Hypergravity Alters the Susceptibility of Cells to Anoxia-Reoxygenation Injury

NASA Technical Reports Server (NTRS)

McCloud, Henry; Pink, Yulondo; Harris-Hooker, Sandra A.; Melhado, Caroline D.; Sanford, Gary L.

1997-01-01

Gravity is a physical force, much like shear stress or mechanical stretch, and should affect organ and cellular function. Researchers have shown that gravity plays a role in ventilation and blood flow distribution, gas exchange, alveolar size and mechanical stresses within the lung. Short exposure to microgravity produced marked alterations in lung blood flow and ventilation distribution while hypergravity exaggerated the regional differences in lung structure and function resulting in reduced ventilation at the base and no ventilation of the upper half of the lung. Microgravity also decreased metabolic activity in cardiac cells, WI-38 embryonic lung cells, and human lymphocytes. Rats, in the tail-suspended head-down tilt model, experienced transient loss of lung water, contrary to an expected increase due to pooling of blood in the pulmonary vasculature. Hypergravity has also been found to increase the proliferation of several different cell lines (e.g., chick embryo fibroblasts) while decreasing cell motility and slowing liver regeneration following partial hepatectomy. These studies show that changes in the gravity environment will affect several aspects of organ and cellular function and produce major change in blood flow and tissue/organ perfusion. However, these past studies have not addressed whether ischemia-reperfusion injury will be exacerbated or ameliorated by changes in the gravity environment, e.g., space flight. Currently, nothing is known about how gravity will affect the susceptibility of different lung and vascular cells to this type of injury. We conducted studies that addressed the following question: Does the susceptibility of lung fibroblasts, vascular smooth muscle, and endothelial cells to anoxia/reoxygenation injury change following exposure to hypergravity conditions?

Chronic Alcohol Ingestion in Rats Alters Lung Metabolism, Promotes Lipid Accumulation, and Impairs Alveolar Macrophage Functions

PubMed Central

Romero, Freddy; Shah, Dilip; Duong, Michelle; Stafstrom, William; Hoek, Jan B.; Kallen, Caleb B.; Lang, Charles H.

2014-01-01

Chronic alcoholism impairs pulmonary immune homeostasis and predisposes to inflammatory lung diseases, including infectious pneumonia and acute respiratory distress syndrome. Although alcoholism has been shown to alter hepatic metabolism, leading to lipid accumulation, hepatitis, and, eventually, cirrhosis, the effects of alcohol on pulmonary metabolism remain largely unknown. Because both the lung and the liver actively engage in lipid synthesis, we hypothesized that chronic alcoholism would impair pulmonary metabolic homeostasis in ways similar to its effects in the liver. We reasoned that perturbations in lipid metabolism might contribute to the impaired pulmonary immunity observed in people who chronically consume alcohol. We studied the metabolic consequences of chronic alcohol consumption in rat lungs in vivo and in alveolar epithelial type II cells and alveolar macrophages (AMs) in vitro. We found that chronic alcohol ingestion significantly alters lung metabolic homeostasis, inhibiting AMP-activated protein kinase, increasing lipid synthesis, and suppressing the expression of genes essential to metabolizing fatty acids (FAs). Furthermore, we show that these metabolic alterations promoted a lung phenotype that is reminiscent of alcoholic fatty liver and is characterized by marked accumulation of triglycerides and free FAs within distal airspaces, AMs, and, to a lesser extent, alveolar epithelial type II cells. We provide evidence that the metabolic alterations in alcohol-exposed rats are mechanistically linked to immune impairments in the alcoholic lung: the elevations in FAs alter AM phenotypes and suppress both phagocytic functions and agonist-induced inflammatory responses. In summary, our work demonstrates that chronic alcohol ingestion impairs lung metabolic homeostasis and promotes pulmonary immune dysfunction. These findings suggest that therapies aimed at reversing alcohol-related metabolic alterations might be effective for preventing and/or treating alcohol-related pulmonary disorders. PMID:24940828

Determinants of Mammalian Nucleolar Architecture

PubMed Central

Farley, Katherine I.; Surovtseva, Yulia; Merkel, Janie; Baserga, Susan J.

2015-01-01

The nucleolus is responsible for the production of ribosomes, essential machines which synthesize all proteins needed by the cell. The structure of human nucleoli is highly dynamic and is directly related to its functions in ribosome biogenesis. Despite the importance of this organelle, the intricate relationship between nucleolar structure and function remains largely unexplored. How do cells control nucleolar formation and function? What are the minimal requirements for making a functional nucleolus? Here we review what is currently known regarding mammalian nucleolar formation at nucleolar organizer regions (NORs), which can be studied by observing the dissolution and reformation of the nucleolus during each cell division. Additionally, the nucleolus can be examined by analyzing how alterations in nucleolar function manifest in differences in nucleolar architecture. Furthermore, changes in nucleolar structure and function are correlated with cancer, highlighting the importance of studying the determinants of nucleolar formation. PMID:25670395

Restriction of Receptor Movement Alters Cellular Response: Physical Force Sensing by EphA2

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

Salaita, Khalid; Nair, Pradeep M; Petit, Rebecca S

2009-09-09

Activation of the EphA2 receptor tyrosine kinase by ephrin-A1 ligands presented on apposed cell surfaces plays important roles in development and exhibits poorly understood functional alterations in cancer. We reconstituted this intermembrane signaling geometry between live EphA2-expressing human breast cancer cells and supported membranes displaying laterally mobile ephrin-A1. Receptor-ligand binding, clustering, and subsequent lateral transport within this junction were observed. EphA2 transport can be blocked by physical barriers nanofabricated onto the underlying substrate. This physical reorganization of EphA2 alters the cellular response to ephrin-A1, as observed by changes in cytoskeleton morphology and recruitment of a disintegrin and metalloprotease 10. Quantitativemore » analysis of receptor-ligand spatial organization across a library of 26 mammary epithelial cell lines reveals characteristic differences that strongly correlate with invasion potential. These observations reveal a mechanism for spatio-mechanical regulation of EphA2 signaling pathways.« less

Lack of broad functional differences in immunity in fully vaccinated vs. unvaccinated children.

PubMed

Sherrid, Ashley M; Ruck, Candice E; Sutherland, Darren; Cai, Bing; Kollmann, Tobias R

2017-04-01

Concerns have been raised that with an increase in the number of vaccines administered early in life, immune development could be altered, leading to either increased or decreased immune reactivity. We investigated the impact of vaccination on immune status, contrasting the immune response to general, nonantigen-specific stimuli in a cohort of entirely unvaccinated vs. fully vaccinated children at 3-5 y of age. Innate immunity was assessed by quantifying bulk and cell-type-specific cytokine production in response to stimulation with pathogen associated microbial patterns. Adaptive immune status was characterized by assessing lymphocyte proliferation and cytokine production in response to generic T cell stimuli. Our investigations failed to reveal a broadly evident alteration of either innate or adaptive immunity in vaccinated children. Equivalently robust innate and adaptive responses to pathogen associated microbial patterns and generic T cell stimulants were observed in both groups. Although our sample size was small, our data suggest that standard childhood vaccinations do not lead to long-lasting gross alterations of the immune system.

Alterations of the bone marrow stromal microenvironment in adult patients with acute myeloid and lymphoblastic leukemias before and after allogeneic hematopoietic stem cell transplantation.

PubMed

Shipounova, Irina N; Petinati, Nataliya A; Bigildeev, Alexey E; Drize, Nina J; Sorokina, Tamara V; Kuzmina, Larisa A; Parovichnikova, Elena N; Savchenko, Valeri G

2017-02-01

Bone marrow (BM) derived adult multipotent mesenchymal stromal cells (MMSCs) and fibroblast colony-forming units (CFU-Fs) of 20 patients with acute myeloid leukemia (AML) and 15 patients with acute lymphoblastic leukemia (ALL) before and during 1 year after receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT) were studied. The growth characteristics of MMSCs of all patients before allo-HSCT were not altered; however, relative expression level (REL) of some genes in MMSCs, but not in CFU-Fs, from AML and ALL patients significantly changed. After allo-HSCT, CFU-F concentration and MMSC production were significantly decreased for 1 year; REL of several genes in MMSCs and CFU-F-derived colonies were also significantly downregulated. Thus, chemotherapy that was used for induction of remission did not impair the function of stromal precursors, but gene expression levels were altered. Allo-HSCT conditioning regimens significantly damaged MMSCs and CFU-Fs, and the effect lasted for at least 1 year.

Distinctive transcriptome alterations of prefrontal pyramidal neurons in schizophrenia and schizoaffective disorder

PubMed Central

Arion, Dominique; Corradi, John P.; Tang, Shaowu; Datta, Dibyadeep; Boothe, Franklyn; He, Aiqing; Cacace, Angela M.; Zaczek, Robert; Albright, Charles F.; Tseng, George; Lewis, David A.

2014-01-01

Schizophrenia is associated with alterations in working memory that reflect dysfunction of dorsolateral prefrontal cortex (DLPFC) circuitry. Working memory depends on the activity of excitatory pyramidal cells in DLPFC layer 3, and to a lesser extent in layer 5. Although many studies have profiled gene expression in DLPFC gray matter in schizophrenia, little is known about cell type-specific transcript expression in these two populations of pyramidal cells. We hypothesized that interrogating gene expression specifically in DLPFC layer 3 or 5 pyramidal cells would reveal new and/or more robust schizophrenia-associated differences that would provide new insights into the nature of pyramidal cell dysfunction in the illness. We also sought to determine the impact of other variables, such as a diagnosis of schizoaffective disorder or medication use at time of death, on the patterns of gene expression in pyramidal neurons. Individual pyramidal cells in DLPFC layers 3 or 5 were captured by laser microdissection from 36 subjects with schizophrenia or schizoaffective disorder and matched normal comparison subjects. The mRNA from cell collections was subjected to transcriptome profiling by microarray followed by qPCR validation. Expression of genes involved in mitochondrial (MT) or ubiquitin-proteasome system (UPS) functions were markedly down-regulated in the patient group (p values for MT-related and UPS-related pathways were <10−7 and <10−5 respectively). MT-related gene alterations were more prominent in layer 3 pyramidal cells, whereas UPS-related gene alterations were more prominent in layer 5 pyramidal cells. Many of these alterations were not present, or found to a lesser degree, in samples of DLPFC gray matter from the same subjects, suggesting that they are pyramidal cell-specific. Furthermore, these findings principally reflected alterations in the schizophrenia subjects, were not present or present to a lesser degree in the schizoaffective disorder subjects (diagnosis of schizoaffective disorder was the most significant covariate, p<10−6), and were not attributable to factors frequently comorbid with schizophrenia. In summary, our findings reveal expression deficits in MT- and UPS-related genes specific to layer 3 and/or layer 5 pyramidal cells in the DLPFC of schizophrenia subjects. These cell type-specific transcriptome signatures are not characteristic of schizoaffective disorder, providing a potential molecular-cellular basis of differences in clinical phenotypes. PMID:25560755

Distinctive transcriptome alterations of prefrontal pyramidal neurons in schizophrenia and schizoaffective disorder.

PubMed

Arion, D; Corradi, J P; Tang, S; Datta, D; Boothe, F; He, A; Cacace, A M; Zaczek, R; Albright, C F; Tseng, G; Lewis, D A

2015-11-01

Schizophrenia is associated with alterations in working memory that reflect dysfunction of dorsolateral prefrontal cortex (DLPFC) circuitry. Working memory depends on the activity of excitatory pyramidal cells in DLPFC layer 3 and, to a lesser extent, in layer 5. Although many studies have profiled gene expression in DLPFC gray matter in schizophrenia, little is known about cell-type-specific transcript expression in these two populations of pyramidal cells. We hypothesized that interrogating gene expression, specifically in DLPFC layer 3 or 5 pyramidal cells, would reveal new and/or more robust schizophrenia-associated differences that would provide new insights into the nature of pyramidal cell dysfunction in the illness. We also sought to determine the impact of other variables, such as a diagnosis of schizoaffective disorder or medication use at the time of death, on the patterns of gene expression in pyramidal neurons. Individual pyramidal cells in DLPFC layers 3 or 5 were captured by laser microdissection from 36 subjects with schizophrenia or schizoaffective disorder and matched normal comparison subjects. The mRNA from cell collections was subjected to transcriptome profiling by microarray followed by quantitative PCR validation. Expression of genes involved in mitochondrial (MT) or ubiquitin-proteasome system (UPS) functions were markedly downregulated in the patient group (P-values for MT-related and UPS-related pathways were <10(-7) and <10(-5), respectively). MT-related gene alterations were more prominent in layer 3 pyramidal cells, whereas UPS-related gene alterations were more prominent in layer 5 pyramidal cells. Many of these alterations were not present, or found to a lesser degree, in samples of DLPFC gray matter from the same subjects, suggesting that they are pyramidal cell specific. Furthermore, these findings principally reflected alterations in the schizophrenia subjects were not present or present to a lesser degree in the schizoaffective disorder subjects (diagnosis of schizoaffective disorder was the most significant covariate, P<10(-6)) and were not attributable to factors frequently comorbid with schizophrenia. In summary, our findings reveal expression deficits in MT- and UPS-related genes specific to layer 3 and/or layer 5 pyramidal cells in the DLPFC of schizophrenia subjects. These cell type-specific transcriptome signatures are not characteristic of schizoaffective disorder, providing a potential molecular-cellular basis of differences in clinical phenotypes.

Titanium Dioxide Nanoparticle Ingestion Alters Nutrient Absorption in an In Vitro Model of the Small Intestine

PubMed Central

Guo, Zhongyuan; Martucci, Nicole J.; Moreno-Olivas, Fabiola; Tako, Elad; Mahler, Gretchen J.

2017-01-01

Ingestion of titanium dioxide (TiO2) nanoparticles from products such as agricultural chemicals, processed food, and nutritional supplements is nearly unavoidable. The gastrointestinal tract serves as a critical interface between the body and the external environment, and is the site of essential nutrient absorption. The goal of this study was to examine the effects of ingesting the 30 nm TiO2 nanoparticles with an in vitro cell culture model of the small intestinal epithelium, and to determine how acute or chronic exposure to nano-TiO2 influences intestinal barrier function, reactive oxygen species generation, proinflammatory signaling, nutrient absorption (iron, zinc, fatty acids), and brush border membrane enzyme function (intestinal alkaline phosphatase). A Caco-2/HT29-MTX cell culture model was exposed to physiologically relevant doses of TiO2 nanoparticles for acute (four hours) or chronic (five days) time periods. Exposure to TiO2 nanoparticles significantly decreased intestinal barrier function following chronic exposure. Reactive oxygen species (ROS) generation, proinflammatory signaling, and intestinal alkaline phosphatase activity all showed increases in response to nano-TiO2. Iron, zinc, and fatty acid transport were significantly decreased following exposure to TiO2 nanoparticles. This is because nanoparticle exposure induced a decrease in absorptive microvilli in the intestinal epithelial cells. Nutrient transporter protein gene expression was also altered, suggesting that cells are working to regulate the transport mechanisms disturbed by nanoparticle ingestion. Overall, these results show that intestinal epithelial cells are affected at a functional level by physiologically relevant exposure to nanoparticles commonly ingested from food. PMID:28944308

Isolated primary blast alters neuronal function with minimal cell death in organotypic hippocampal slice cultures.

PubMed

Effgen, Gwen B; Vogel, Edward W; Lynch, Kimberly A; Lobel, Ayelet; Hue, Christopher D; Meaney, David F; Bass, Cameron R Dale; Morrison, Barclay

2014-07-01

An increasing number of U.S. soldiers are diagnosed with traumatic brain injury (TBI) subsequent to exposure to blast. In the field, blast injury biomechanics are highly complex and multi-phasic. The pathobiology caused by exposure to some of these phases in isolation, such as penetrating or inertially driven injuries, has been investigated extensively. However, it is unclear whether the primary component of blast, a shock wave, is capable of causing pathology on its own. Previous in vivo studies in the rodent and pig have demonstrated that it is difficult to deliver a primary blast (i.e., shock wave only) without rapid head accelerations and potentially confounding effects of inertially driven TBI. We have previously developed a well-characterized shock tube and custom in vitro receiver for exposing organotypic hippocampal slice cultures to pure primary blast. In this study, isolated primary blast induced minimal hippocampal cell death (on average, below 14% in any region of interest), even for the most severe blasts tested (424 kPa peak pressure, 2.3 ms overpressure duration, and 248 kPa*ms impulse). In contrast, measures of neuronal function were significantly altered at much lower exposures (336 kPa, 0.84 ms, and 86.5 kPa*ms), indicating that functional changes occur at exposures below the threshold for cell death. This is the first study to investigate a tolerance for primary blast-induced brain cell death in response to a range of blast parameters and demonstrate functional deficits at subthreshold exposures for cell death.

Loss of an actin crosslinker uncouples cell spreading from cell stiffening on gels with a gradient of stiffness

NASA Astrophysics Data System (ADS)

Wen, Qi; Byfield, Fitzroy J.; Nordstrom, Kerstin; Arratia, Paulo E.; Miller, R. Tyler; Janmey, Paul A.

2009-03-01

We use microfluidics techniques to produce gels with a gradient of stiffness to show the essential function of the actin crosslinker filamin A in cell responses to mechanical stimuli. M2 melanoma cells null for filamin A do not alter their adherent area in response to increased substrate stiffness when they link to the substrate only through collagen receptors, but change adherent area normally when bound through fibronectin receptors. In contrast, filamin A-replete A7 cells change adherent area on both substrates and respond more strongly to collagen 1-coated gels than to fibronectin-coated gels. A7 cells alter their stiffness, as measured by atomic force microscopy, to match the elastic modulus of the substrate immediately adjacent to them on the gradient. M2 cells, in contrast, maintain a constant stiffness on all substrates that is as low as that of A7 cells on the softest gels achievable (1000 Pa). By contrasting the responses of these cell types to different adhesive substrates, cell spreading can be dissociated from stiffening.

Role of selenium-containing proteins in T cell and macrophage function

PubMed Central

Carlson, Bradley A.; Yoo, Min-Hyuk; Shrimali, Rajeev K.; Irons, Robert; Gladyshev, Vadim N.; Hatfield, Dolph L.; Park, Jin Mo

2011-01-01

Synopsis Selenium has been known for many years to have a role in boosting immune function, but the manner in which this element acts at the molecular level in host defense and inflammatory diseases is poorly understood. To elucidate the role of selenium-containing proteins in immune function, we knocked out the expression of this protein class in T cells or macrophages of mice by targeting the removal of the selenocysteine tRNA gene using loxP-Cre technology. Mice with selenoprotein-less T cells manifested reduced pools of mature and functional T cells in lymphoid tissues and an impairment in T cell-dependent antibody responses. Furthermore, selenoprotein deficiency in T cells led to an inability of these cells to suppress reactive oxygen species (ROS) production, which in turn affected their ability to proliferate in response to T cell receptor stimulation. Selenoprotein-less macrophages, on the other hand, manifested mostly normal inflammatory responses, but this deficiency resulted in an altered regulation in extracellular matrix-related gene expression and a diminished migration of macrophages in a protein gel matrix. These observations provided novel insights into the role of selenoproteins in immune function and tissue homeostasis. PMID:20576203

Pressure Induced Changes in Adaptive Immune Function in Belugas (Delphinapterus leucas); Implications for Dive Physiology and Health

PubMed Central

Thompson, Laura A.; Romano, Tracy A.

2016-01-01

Increased pressure, associated with diving, can alter cell function through several mechanisms and has been shown to impact immune functions performed by peripheral blood mononuclear cells (PBMC) in humans. While marine mammals possess specific adaptations which protect them from dive related injury, it is unknown how their immune system is adapted to the challenges associated with diving. The purpose of this study was to measure PBMC activation (IL2R expression) and Concanavalin A induced lymphocyte proliferation (BrdU incorporation) in belugas following in vitro pressure exposures during baseline, Out of Water Examination (OWE) and capture/release conditions. Beluga blood samples (n = 4) were obtained from animals at the Mystic Aquarium and from free ranging animals in Alaska (n = 9). Human blood samples (n = 4) (Biological Specialty Corporation) were run for comparison. In vivo catecholamines and cortisol were measured in belugas to characterize the neuroendocrine response. Comparison of cellular responses between controls and pressure exposed cells, between conditions in belugas, between belugas and humans as well as between dive profiles, were run using mixed generalized linear models (α = 0.05). Cortisol was significantly higher in Bristol Bay belugas and OWE samples as compared with baseline for aquarium animals. Both IL2R expression and proliferation displayed significant pressure induced changes, and these responses varied between conditions in belugas. Both belugas and humans displayed increased IL2R expression, while lymphocyte proliferation decreased for aquarium animals and increased for humans and Bristol Bay belugas. Results suggest beluga PBMC function is altered during diving and changes may represent dive adaptation as the response differs from humans, a non-dive adapted mammal. In addition, characteristics of a dive (i.e., duration, depth) as well as neuroendocrine activity can alter the response of beluga cells, potentially impacting the ability of animals to fight infection or avoid dive related pathologies. PMID:27746745

Pressure Induced Changes in Adaptive Immune Function in Belugas (Delphinapterus leucas); Implications for Dive Physiology and Health.

PubMed

Thompson, Laura A; Romano, Tracy A

2016-01-01

Increased pressure, associated with diving, can alter cell function through several mechanisms and has been shown to impact immune functions performed by peripheral blood mononuclear cells (PBMC) in humans. While marine mammals possess specific adaptations which protect them from dive related injury, it is unknown how their immune system is adapted to the challenges associated with diving. The purpose of this study was to measure PBMC activation (IL2R expression) and Concanavalin A induced lymphocyte proliferation (BrdU incorporation) in belugas following in vitro pressure exposures during baseline, Out of Water Examination (OWE) and capture/release conditions. Beluga blood samples ( n = 4) were obtained from animals at the Mystic Aquarium and from free ranging animals in Alaska ( n = 9). Human blood samples ( n = 4) (Biological Specialty Corporation) were run for comparison. In vivo catecholamines and cortisol were measured in belugas to characterize the neuroendocrine response. Comparison of cellular responses between controls and pressure exposed cells, between conditions in belugas, between belugas and humans as well as between dive profiles, were run using mixed generalized linear models (α = 0.05). Cortisol was significantly higher in Bristol Bay belugas and OWE samples as compared with baseline for aquarium animals. Both IL2R expression and proliferation displayed significant pressure induced changes, and these responses varied between conditions in belugas. Both belugas and humans displayed increased IL2R expression, while lymphocyte proliferation decreased for aquarium animals and increased for humans and Bristol Bay belugas. Results suggest beluga PBMC function is altered during diving and changes may represent dive adaptation as the response differs from humans, a non-dive adapted mammal. In addition, characteristics of a dive (i.e., duration, depth) as well as neuroendocrine activity can alter the response of beluga cells, potentially impacting the ability of animals to fight infection or avoid dive related pathologies.

Simulated Microgravity Alters Actin Cytoskeleton and Integrin-Mediated Focal Adhesions of Cultured Human Mesenchymal Stromal Cells

NASA Astrophysics Data System (ADS)

Gershovich, P. M.; Gershovic, J. G.; Buravkova, L. B.

2008-06-01

Cytoskeletal alterations occur in several cell types including lymphocytes, glial cells, and osteoblasts, during spaceflight and under simulated microgravity (SMG) (3, 4). One potential mechanism for cytoskeletal gravisensitivity is disruption of extracellular matrix (ECM) and integrin interactions. Focal adhesions are specialized sites of cell-matrix interaction composed of integrins and the diversity of focal adhesion-associated cytoplasmic proteins including vinculin, talin, α-actinin, and actin filaments (4, 5). Integrins produce signals essential for proper cellular function, survival and differentiation. Therefore, we investigated the effects of SMG on F-actin cytoskeleton structure, vinculin focal adhesions, expression of some integrin subtypes and cellular adhesion molecules (CAMs) in mesenchymal stem cells derived from human bone marrow (hMSCs). Simulated microgravity was produced by 3D-clinostat (Dutch Space, Netherlands). Staining of actin fibers with TRITC-phalloidin showed reorganization even after 30 minutes of simulated microgravity. The increasing of cells number with abnormal F-actin was observed after subsequent terms of 3D-clinorotation (6, 24, 48, 120 hours). Randomization of gravity vector altered dimensional structure of stress fibers and resulted in remodeling of actin fibers inside the cells. In addition, we observed vinculin redistribution inside the cells after 6 hours and prolonged terms of clinorotation. Tubulin fibers in a contrast with F-actin and vinculin didn't show any reorganization even after long 3Dclinorotation (120 hours). The expression of integrin α2 increased 1,5-6-fold in clinorotated hMSCs. Also we observed decrease in number of VCAM-1-positive cells and changes in expression of ICAM-1. Taken together, our findings indicate that SMG leads to microfilament and adhesion alterations of hMSCs most probably associated with involvement of some integrin subtypes.

Altered gene products involved in the malignant reprogramming of cancer stem/progenitor cells and multitargeted therapies

PubMed Central

Mimeault, Murielle; Batra, Surinder K.

2013-01-01

Recent studies in the field of cancer stem cells have revealed that the alterations in key gene products involved in the epithelial-mesenchymal transition (EMT) program, altered metabolic pathways such as enhanced glycolysis, lipogenesis and/or autophagy and treatment resistance may occur in cancer stem/progenitor cells and their progenies during cancer progression. Particularly, the sustained activation of diverse developmental cascades such as hedgehog, epidermal growth factor receptor (EGFR), Wnt/β-catenin, Notch, transforming growth factor-β (TGF-β)/TGF-βR receptors and/or stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor 4 (CXCR4) can play critical functions for high self-renewal potential, survival, invasion and metastases of cancer stem/progenitor cells and their progenies. It has also been observed that cancer cells may be reprogrammed to re-express different pluripotency-associated stem cell-like markers such as Myc, Oct-3/4, Nanog and Sox-2 along the EMT process and under stressful and hypoxic conditions. Moreover, the enhanced expression and/or activities of some drug resistance-associated molecules such as Bcl-2, Akt/molecular target of rapamycin (mTOR), nuclear factor-kappaB (NF-κB), hypoxia-inducible factors (HIFs), macrophage inhibitory cytokine-1 (MIC-1) and ATP-binding cassette (ABC) multidrug transporters frequently occur in cancer cells during cancer progression and metastases. These molecular events may cooperate for the survival and acquisition of a more aggressive and migratory behavior by cancer stem/progenitor cells and their progenies during cancer transition to metastatic and recurrent disease states. Of therapeutic interest, these altered gene products may also be exploited as molecular biomarkers and therapeutic targets to develop novel multitargeted strategies for improving current cancer therapies and preventing disease relapse. PMID:23994756

Immunological changes following protein losing enteropathy after surgery total cavopulmonary connection (TCPC) by cytomics

NASA Astrophysics Data System (ADS)

Bocsi, József; Lenz, Dominik; Mittag, Anja; Sauer, Ursula; Wild, Lena; Hess, John; Schranz, Dietmar; Hambsch, Jörg; Schneider, Peter; Tárnok, Attila

2008-02-01

Complex immunophenotyping single-cell analysis are essential for systems biology and cytomics. The application of cytomics in immunology and cardiac research and diagnostics is very broad, ranging from the better understanding of the cardiovascular cell biology to the identification of heart function and immune consequences after surgery. TCPC or Fontan-type circulation is an accepted palliative surgery for patients with a functionally univentricular heart. Protein-losing enteropathy (PLE), the enteric loss of proteins, is a potential late complication after TCPC surgery. PLE etiology is poorly understood, but immunological factors seem to play a role. This study was aimed to gain insight into immune phenotype alterations following post-TCPC PLE. Patients were studied during routine follow-up up to 5yrs after surgery, blood samples of TCPC patients without (n=21, age 6.8+/-2.6 years at surgery; mean+/-SD) and with manifest PLE (n=12, age 12.8+/- 4.5 years at sampling) and age matched healthy children (control, n=22, age 8.6+/-2.5 years) were collected. Routine laboratory, immune phenotype and serological parameters were determined. Following PLE the immune phenotype dramatically changed with signs of acute inflammation (increased neutrophil and monocyte count, CRP, IL-8). In contrast, lymphocyte count (NK-cells, αβTCR +CD4 +, αβTCR +CD8 + cells) decreased (p<0.001). The residual T-cells had elevated CD25 and CD69 expression. In PLE-patients unique cell populations with CD3 +αβ/γδTCR - and αβTCR +CD4 -8 - phenotype were present in increased frequencies. Our studies show dramatically altered leukocyte phenotype after PLE in TCPC patients. These alterations resemble to changes in autoimmune diseases. We conclude that autoimmune processes may play a role in etiology and pathophysiology of PLE.

Catechin supplemented in a FOS diet induces weight loss by altering cecal microbiota and gene expression of colonic epithelial cells.

PubMed

Luo, Jianming; Han, Lulu; Liu, Liu; Gao, Lijuan; Xue, Bin; Wang, Yong; Ou, Shiyi; Miller, Michael; Peng, Xichun

2018-05-23

Our previous study showed that catechin controlled rats' body weights and changed gut microbiota composition when supplemented into a high-fructo-oligosaccharide (FOS) diet. This experiment is devised to further confirm the relationship between specific bacteria in the colon and body weight gain, and to investigate how specific bacteria impact body weight by changing the expression of colonic epithelial cells. Forty obese rats were divided into four groups: three catechin-supplemented groups with a high-FOS diet (100, 400, and 700 mg kg-1 d-1 catechin, orally administered) and one group with a high-FOS diet only. Food consumption and body weights were recorded each week. After one month of treatment, rats' cecal content and colonic epithelial cells were individually collected and analyzed with MiSeq and gene expression profiling techniques, respectively. Results identified some specific bacteria at the genus level-including the increased Parabacteroides sp., Prevotella sp., Robinsoniella sp., [Ruminococcus], Phascolarctobacterium sp. and an unknown genus of YS2, and the decreased Lachnospira sp., Oscillospira sp., Ruminococcus sp., an unknown genus of Peptococcaceae and an unknown genus of Clostridiales in rats' cecum-and eight genes-including one downregulated Pla2g2a and seven upregulated genes: Apoa1, Apoa4, Aabr07073400.1, Fabp4, Pik3r5, Dgat2 and Ptgs2 of colonic epithelial cells-that were due to the consumption of catechin. Consequently, various biological functions in connection with energy metabolism in colonic epithelial cells were altered, including fat digestion and absorption and the regulation of lipolysis in adipocytes. In conclusion, catechin induces host weight loss by altering gut microbiota and gene expression and function in colonic epithelial cells.

Pericellular Versican Regulates the Fibroblast-Myofibroblast Transition

PubMed Central

Hattori, Noriko; Carrino, David A.; Lauer, Mark E.; Vasanji, Amit; Wylie, James D.; Nelson, Courtney M.; Apte, Suneel S.

2011-01-01

The cell and its glycosaminoglycan-rich pericellular matrix (PCM) comprise a functional unit. Because modification of PCM influences cell behavior, we investigated molecular mechanisms that regulate PCM volume and composition. In fibroblasts and other cells, aggregates of hyaluronan and versican are found in the PCM. Dermal fibroblasts from Adamts5−/− mice, which lack a versican-degrading protease, ADAMTS5, had reduced versican proteolysis, increased PCM, altered cell shape, enhanced α-smooth muscle actin (SMA) expression and increased contractility within three-dimensional collagen gels. The myofibroblast-like phenotype was associated with activation of TGFβ signaling. We tested the hypothesis that fibroblast-myofibroblast transition in Adamts5−/− cells resulted from versican accumulation in PCM. First, we noted that versican overexpression in human dermal fibroblasts led to increased SMA expression, enhanced contractility, and increased Smad2 phosphorylation. In contrast, dermal fibroblasts from Vcan haploinsufficient (Vcanhdf/+) mice had reduced contractility relative to wild type fibroblasts. Using a genetic approach to directly test if myofibroblast transition in Adamts5−/− cells resulted from increased PCM versican content, we generated Adamts5−/−;Vcanhdf/+ mice and isolated their dermal fibroblasts for comparison with dermal fibroblasts from Adamts5−/− mice. In Adamts5−/− fibroblasts, Vcan haploinsufficiency or exogenous ADAMTS5 restored normal fibroblast contractility. These findings demonstrate that altering PCM versican content through proteolytic activity of ADAMTS5 profoundly influenced the dermal fibroblast phenotype and may regulate a phenotypic continuum between the fibroblast and its alter ego, the myofibroblast. We propose that a physiological function of ADAMTS5 in dermal fibroblasts is to maintain optimal versican content and PCM volume by continually trimming versican in hyaluronan-versican aggregates. PMID:21828051

Improved motor performance in Dyt1 ΔGAG heterozygous knock-in mice by cerebellar Purkinje-cell specific Dyt1 conditional knocking-out

PubMed Central

Yokoi, Fumiaki; Dang, Mai Tu; Li, Yuqing

2012-01-01

Early-onset generalized torsion dystonia (dystonia 1) is an inherited movement disorder caused by mutations in DYT1 (TOR1A), which codes for torsinA. Most patients have a 3-base pair deletion (ΔGAG) in one allele of DYT1, corresponding to a loss of a glutamic acid residue (ΔE) in the C-terminal region of the protein. Functional alterations in basal ganglia circuits and the cerebellum have been reported in dystonia. Pharmacological manipulations or mutations in genes that result in functional alterations of the cerebellum have been reported to have dystonic symptoms and have been used as phenotypic rodent models. Additionally, structural lesions in the abnormal cerebellar circuits, such as cerebellectomy, have therapeutic effects in these models. A previous study has shown that the Dyt1 ΔGAG heterozygous knock-in (KI) mice exhibit motor deficits in the beam-walking test. Both Dyt1 ΔGAG heterozygous knock-in (KI) and Dyt1 Purkinje cell-specific knockout (Dyt1 pKO) mice exhibit dendritic alterations of cerebellar Purkinje cells. Here, Dyt1 pKO mice exhibited significantly less slip numbers in the beam-walking test, suggesting better motor performance than control littermates, and normal gait. Furthermore, Dyt1 ΔGAG KI/Dyt1 pKO double mutant mice exhibited significantly lower numbers of slips than Dyt1 ΔGAG heterozygous KI mice, suggesting Purkinje-cell specific knockout of Dyt1 wild-type (WT) allele in Dyt1 ΔGAG heterozygous KI mice rescued the motor deficits. The results suggest that molecular lesions of torsinA in Purkinje cells by gene therapy or intervening in the signaling pathway downstream of the cerebellar Purkinje cells may rescue motor symptoms in dystonia 1. PMID:22391119

Impaired Lysosomal Function Underlies Monoclonal Light Chain–Associated Renal Fanconi Syndrome

PubMed Central

Luciani, Alessandro; Sirac, Christophe; Terryn, Sara; Javaugue, Vincent; Prange, Jenny Ann; Bender, Sébastien; Bonaud, Amélie; Cogné, Michel; Aucouturier, Pierre; Ronco, Pierre

2016-01-01

Monoclonal gammopathies are frequently complicated by kidney lesions that increase the disease morbidity and mortality. In particular, abnormal Ig free light chains (LCs) may accumulate within epithelial cells, causing proximal tubule (PT) dysfunction and renal Fanconi syndrome (RFS). To investigate the mechanisms linking LC accumulation and PT dysfunction, we used transgenic mice overexpressing human control or RFS-associated κLCs (RFS-κLCs) and primary cultures of mouse PT cells exposed to low doses of corresponding human κLCs (25 μg/ml). Before the onset of renal failure, mice overexpressing RFS-κLCs showed PT dysfunction related to loss of apical transporters and receptors and increased PT cell proliferation rates associated with lysosomal accumulation of κLCs. Exposure of PT cells to RFS-κLCs resulted in κLC accumulation within enlarged and dysfunctional lysosomes, alteration of cellular dynamics, defective proteolysis and hydrolase maturation, and impaired lysosomal acidification. These changes were specific to the RFS-κLC variable (V) sequence, because they did not occur with control LCs or the same RFS-κLC carrying a single substitution (Ala30→Ser) in the V domain. The lysosomal alterations induced by RFS-κLCs were reflected in increased cell proliferation, decreased apical expression of endocytic receptors, and defective endocytosis. These results reveal that specific κLCs accumulate within lysosomes, altering lysosome dynamics and proteolytic function through defective acidification, thereby causing dedifferentiation and loss of reabsorptive capacity of PT cells. The characterization of these early events, which are similar to those encountered in congenital lysosomal disorders, provides a basis for the reported differential LC toxicity and new perspectives on LC-induced RFS. PMID:26614382

Effect of Spaceflight on the Functions of NK and LAK Cells

NASA Technical Reports Server (NTRS)

Pierson, Duane L.; Grimm, Elizabeth A.; Pierson, Duane L.; Paloski, W. H. (Technical Monitor)

1999-01-01

Spaceflight-associated stress alters some aspects of the human immune response. In this study, we determined the effects of 10 days aboard the Space Shuttle on the cytotoxic activity of NK and LAK cells. The subjects of this study were crewmembers of two 10-day shuttle flights. Ten-ml blood specimens were obtained from ten astronauts 10 days before launch, immediately after landing, and 3 days after landing. PBMCs were separated from the blood specimens and stored at -800 C. All PBMCs were thawed simultaneously, and the cytotoxic activities of NK and LAK cells were measured by a 4-hour Cr-51 release assay. K562 cells were used to assess NK-cell cytotoxicity. After 4 days of IL-2 activation, the LAK cell cytotoxic activity was determined using K562 and Daudi cells as the target cells. NK-cell cytotoxicity was decreased at landing (p less than 0.0005) in 9/10 astronauts, and in most cases recovered to preflight levels by 3 days after landing; NK-cell cytotoxicity was increased in one astronaut at landing. LAK cytotoxic activity against K562 cells was decreased at landing in 6/10 astronauts (p=0.018), and activity against Daudi cells was decreased in 7/10 astronauts (p=0.01). Phenotyping of PBMCs and LAK cells showed alterations in some surface markers and adhesion molecules (CD1 1 b, CD1 1 c, CD1 1 a, CD1 6, L-Selectin and CD3). Thus spaceflight leads to a decrease in the functions of NK and LAK cells in most astronauts.

Co-regulation of Primary Mouse Hepatocyte Viability and Function by Oxygen and Matrix

PubMed Central

Buck, Lorenna D.; Inman, S. Walker; Rusyn, Ivan; Griffith, Linda G.

2014-01-01

Although oxygen and extracellular matrix cues both influence differentiation state and metabolic function of primary rat and human hepatocytes, relatively little is known about how these factors together regulate behaviors of primary mouse hepatocytes in culture. To determine the effects of pericellular oxygen tension on hepatocellular function, we employed 2 methods of altering oxygen concentration in the local cellular microenvironment of cells cultured in the presence or absence of an extracellular matrix (Matrigel) supplement. By systematically altering medium depth and gas phase oxygen tension, we created multiple oxygen regimes (hypoxic, normoxic, and hyperoxic) and measured the local oxygen concentrations in the pericellular environment using custom-designed oxygen microprobes. From these measurements of oxygen concentrations, we derived values of oxygen consumption rates under a spectrum of environmental contexts, thus providing the first reported estimates of these values for primary mouse hepatocytes. Oxygen tension and matrix microenvironment were found to synergistically regulate hepatocellular survival and function as assessed using quantitative image analysis for cells stained with vital dyes, and assessment of secretion of albumin. Hepatocellular viability was affected only at strongly hypoxic conditions. Surprisingly, albumin secretion rates were greatest at a moderately supra-physiological oxygen concentration, and this effect was mitigated at still greater supra-physiological concentrations. Matrigel enhanced the effects of oxygen on retention of function. This study underscores the importance of carefully controlling cell density, medium depth and gas phase oxygen, as the effects of these parameters on local pericellular oxygen tension and subsequent hepatocellular function are profound. PMID:24222008

RNAi Technique in Stem Cell Research: Current Status and Future Perspectives.

PubMed

Zou, Gang-Ming

2017-01-01

RNAi is a mechanism displayed by most eukaryotic cells to rid themselves of foreign double-strand RNA molecules. In the 18 years since the initial report, RNAi has now been demonstrated to function in mammalian cells to alter gene expression and has been used as a means for genetic discovery as well as a possible strategy for genetic correction and genetic therapy in cancer and other disease. The aim of this review is to provide a general overview of how RNAi suppresses gene expression and to examine some published RNAi approaches that have resulted in changes in stem cell function and suggest the possible clinical relevance of this work in cancer therapy through targeting cancer stem cells.

Surfactant functionalization induces robust, differential adhesion of tumor cells and blood cells to charged nanotube-coated biomaterials under flow.

PubMed

Mitchell, Michael J; Castellanos, Carlos A; King, Michael R

2015-07-01

The metastatic spread of cancer cells from the primary tumor to distant sites leads to a poor prognosis in cancers originating from multiple organs. Increasing evidence has linked selectin-based adhesion between circulating tumor cells (CTCs) and endothelial cells of the microvasculature to metastatic dissemination, in a manner similar to leukocyte adhesion during inflammation. Functionalized biomaterial surfaces hold promise as a diagnostic tool to separate CTCs and potentially treat metastasis, utilizing antibody and selectin-mediated interactions for cell capture under flow. However, capture at high purity levels is challenged by the fact that CTCs and leukocytes both possess selectin ligands. Here, a straightforward technique to functionalize and alter the charge of naturally occurring halloysite nanotubes using surfactants is reported to induce robust, differential adhesion of tumor cells and blood cells to nanotube-coated surfaces under flow. Negatively charged sodium dodecanoate-functionalized nanotubes simultaneously enhanced tumor cell capture while negating leukocyte adhesion, both in the presence and absence of adhesion proteins, and can be utilized to isolate circulating tumor cells regardless of biomarker expression. Conversely, diminishing nanotube charge via functionalization with decyltrimethylammonium bromide both abolished tumor cell capture while promoting leukocyte adhesion. Copyright © 2015 Elsevier Ltd. All rights reserved.

Brain and Bone Damage in KARAP/DAP12 Loss-of-Function Mice Correlate with Alterations in Microglia and Osteoclast Lineages

PubMed Central

Nataf, Serge; Anginot, Adrienne; Vuaillat, Carine; Malaval, Luc; Fodil, Nassima; Chereul¶, Emmanuel; Langlois¶, Jean-Baptiste; Dumontel, Christiane; Cavillon, Gaelle; Confavreux, Christian; Mazzorana, Marlène; Vico, Laurence; Belin, Marie-Franaçoise; Vivier, Eric; Tomasello, Elena; Jurdic, Pierre

2005-01-01

Human polycystic lipomembraneous osteodysplasia with sclerosing leukoencephalopathy, also known as Nasu-Hakola disease, has been described to be associated with mutations affecting the immunoreceptor tyrosine-based activation motif-bearing KARAP/DAP12 immunoreceptor gene. Patients present bone fragilities and severe neurological alterations leading to presenile dementia. Here we investigated whether the absence of KARAP/DAP12-mediated signals in loss-of-function (KΔ75) mice also leads to bone and central nervous system pathological features. Histological analysis of adult KΔ75 mice brains revealed a diffuse hypomyelination predominating in anterior brain regions. As this was not accompanied by oligodendrocyte degeneration or microglial cell activation it suggests a developmental defect of myelin formation. Interestingly, in postnatal KΔ75 mice, we observed a dramatic reduction in microglial cell numbers similar to in vitro microglial cell differentiation impairment. Our results raise the intriguing possibility that defective microglial cell differentiation might be responsible for abnormal myelin development. Histomorphometry revealed that bone remodeling is also altered, because of a resorption defect, associated with a severe block of in vitro osteoclast differentiation. In addition, we show that, among monocytic lineages, KARAP/DAP12 specifically controls microglial and osteoclast differentiation. Our results confirm that KARAP/DAP12-mediated signals play an important role in the regulation of both brain and bone homeostasis. Yet, important differences exist between the symptoms observed in Nasu-Hakola patients and KΔ75 mice. PMID:15632019

Caenorhabditis elegans par2.1/mtssb-1 is essential for mitochondrial DNA replication and its defect causes comprehensive transcriptional alterations including a hypoxia response

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

Sugimoto, Tomoko; Mori, Chihiro; Takanami, Takako

2008-01-01

DNA polymerase {gamma} and mtSSB are key components of the mtDNA replication machinery. To study the biological influences of defects in mtDNA replication, we used RNAi to deplete the gene for a putative mtSSB, par2.1, in Caenorhabditis elegans. In previous systematic RNAi screens, downregulation of this gene has not caused any clearly defective phenotypes. Here, we continuously fed a dsRNA targeting par2.1 to C. elegans over generations. Seventy-nine percent of F1 progeny produced 60-72 h after feeding grew to adulthood but were completely sterile, with an arrest of germline cell proliferation. Analyses of mtDNA copy number and cell cytology indicatedmore » that the sterile hermaphrodites had fewer mitochondria. These results indicated that par2.1 essentially functions for germline cell proliferation through mtDNA replication; we therefore termed it mtssb-1. Comprehensive transcriptional alterations including hypoxia response induction dependent on and independent of hif-1 function, occurred by RNAi depletion of mtssb-1. Treatment with ethidium bromide, which impairs mtDNA replication and transcription, caused similar transcriptional alterations. In addition, the frequency of apoptosis in the germline cells was reduced in fertile progeny with a partial RNAi effect. These suggest that RNAi depletion of C. elegans mtssb-1 is useful as a model system of mitochondrial dysfunction.« less

Osmotic Homeostasis

PubMed Central

Zeidel, Mark L.

2015-01-01

Alterations in water homeostasis can disturb cell size and function. Although most cells can internally regulate cell volume in response to osmolar stress, neurons are particularly at risk given a combination of complex cell function and space restriction within the calvarium. Thus, regulating water balance is fundamental to survival. Through specialized neuronal “osmoreceptors” that sense changes in plasma osmolality, vasopressin release and thirst are titrated in order to achieve water balance. Fine-tuning of water absorption occurs along the collecting duct, and depends on unique structural modifications of renal tubular epithelium that confer a wide range of water permeability. In this article, we review the mechanisms that ensure water homeostasis as well as the fundamentals of disorders of water balance. PMID:25078421

Skeletal muscle tissue transcriptome differences in lean and obese female beagle dogs.

PubMed

Grant, R W; Vester Boler, B M; Ridge, T K; Graves, T K; Swanson, K S

2013-08-01

Skeletal muscle is a large and insulin-sensitive tissue that is an important contributor to metabolic homeostasis and energy expenditure. Many metabolic processes are altered with obesity, but the contribution of muscle tissue in this regard is unclear. A limited number of studies have compared skeletal muscle gene expression of lean and obese dogs. Using microarray technology, our objective was to identify genes and functional classes differentially expressed in skeletal muscle of obese (14.6 kg; 8.2 body condition score; 44.5% body fat) vs. lean (8.6 kg; 4.1 body condition score; 22.9% body fat) female beagle adult dogs. Alterations in 77 transcripts was observed in genes pertaining to the functional classes of signaling, transport, protein catabolism and proteolysis, protein modification, development, transcription and apoptosis, cell cycle and differentiation. Genes differentially expressed in obese vs. lean dog skeletal muscle indicate oxidative stress and altered skeletal muscle cell differentiation. Many genes traditionally associated with lipid, protein and carbohydrate metabolism were not altered in obese vs. lean dogs, but genes pertaining to endocannabinoid metabolism, insulin signaling, type II diabetes mellitus and carnitine transport were differentially expressed. The relatively small response of skeletal muscle could indicate that changes are occurring at a post-transcriptional level, that other tissues (e.g., adipose tissue) were buffering skeletal muscle from metabolic dysfunction or that obesity-induced changes in skeletal muscle require a longer period of time and that the length of our study was not sufficient to detect them. Although only a limited number of differentially expressed genes were detected, these results highlight genes and functional classes that may be important in determining the etiology of obesity-induced derangement of skeletal muscle function. © 2013 The Authors, Animal Genetics © 2013 Stichting International Foundation for Animal Genetics.