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Sample records for altered cellular functions

  1. Altered lysosomal positioning affects lysosomal functions in a cellular model of Huntington's disease.

    PubMed

    Erie, Christine; Sacino, Matthew; Houle, Lauren; Lu, Michael L; Wei, Jianning

    2015-08-01

    Huntington's disease (HD) is a hereditary and devastating neurodegenerative disorder caused by a mutation in the huntingtin protein. Understanding the functions of normal and mutant huntingtin protein is the key to revealing the pathogenesis of HD and developing therapeutic targets. Huntingtin plays an important role in vesicular and organelle trafficking. Lysosomes are dynamic organelles that integrate several degradative pathways and regulate the activity of mammalian target of rapamycin complex 1 (mTORC1). In the present study, we found that the perinuclear accumulation of lysosomes was increased in a cellular model of HD derived from HD knock-in mice and primary fibroblasts from an HD patient. This perinuclear lysosomal accumulation could be reversed when normal huntingtin was overexpressed in HD cells. When we further investigated the functional significance of the increased perinuclear lysosomal accumulation in HD cells, we demonstrated that basal mTORC1 activity was increased in HD cells. In addition, autophagic influx was also increased in HD cells in response to serum deprivation, which leads to premature fusion of lysosomes with autophagosomes. Taken together, our data suggest that the increased perinuclear accumulation of lysosomes may play an important role in HD pathogenesis by altering lysosomal-dependent functions. PMID:25997742

  2. Anacardic Acid, Salicylic Acid, and Oleic Acid Differentially Alter Cellular Bioenergetic Function in Breast Cancer Cells.

    PubMed

    Radde, Brandie N; Alizadeh-Rad, Negin; Price, Stephanie M; Schultz, David J; Klinge, Carolyn M

    2016-11-01

    Anacardic acid is a dietary and medicinal phytochemical that inhibits breast cancer cell proliferation and uncouples oxidative phosphorylation (OXPHOS) in isolated rat liver mitochondria. Since mitochondrial-targeted anticancer therapy (mitocans) may be useful in breast cancer, we examined the effect of anacardic acid on cellular bioenergetics and OXPHOS pathway proteins in breast cancer cells modeling progression to endocrine-independence: MCF-7 estrogen receptor α (ERα)+ endocrine-sensitive; LCC9 and LY2 ERα+, endocrine-resistant, and MDA-MB-231 triple negative breast cancer (TNBC) cells. At concentrations similar to cell proliferation IC50 s, anacardic acid reduced ATP-linked oxygen consumption rate (OCR), mitochondrial reserve capacity, and coupling efficiency while increasing proton leak, reflecting mitochondrial toxicity which was greater in MCF-7 compared to endocrine-resistant and TNBC cells. These results suggest tolerance in endocrine-resistant and TNBC cells to mitochondrial stress induced by anacardic acid. Since anacardic acid is an alkylated 2-hydroxybenzoic acid, the effects of salicylic acid (SA, 2-hydroxybenzoic acid moiety) and oleic acid (OA, monounsaturated alkyl moiety) were tested. SA inhibited whereas OA stimulated cell viability. In contrast to stimulation of basal OCR by anacardic acid (uncoupling effect), neither SA nor OA altered basal OCR- except OA inhibited basal and ATP-linked OCR, and increased ECAR, in MDA-MB-231 cells. Changes in OXPHOS proteins correlated with changes in OCR. Overall, neither the 2-hydroxybenzoic acid moiety nor the monounsaturated alky moiety of anacardic acid is solely responsible for the observed mitochondria-targeted anticancer activity in breast cancer cells and hence both moieties are required in the same molecule for the observed effects. J. Cell. Biochem. 117: 2521-2532, 2016. © 2016 Wiley Periodicals, Inc. PMID:26990649

  3. Defects in TRPM7 channel function deregulate thrombopoiesis through altered cellular Mg(2+) homeostasis and cytoskeletal architecture.

    PubMed

    Stritt, Simon; Nurden, Paquita; Favier, Remi; Favier, Marie; Ferioli, Silvia; Gotru, Sanjeev K; van Eeuwijk, Judith M M; Schulze, Harald; Nurden, Alan T; Lambert, Michele P; Turro, Ernest; Burger-Stritt, Stephanie; Matsushita, Masayuki; Mittermeier, Lorenz; Ballerini, Paola; Zierler, Susanna; Laffan, Michael A; Chubanov, Vladimir; Gudermann, Thomas; Nieswandt, Bernhard; Braun, Attila

    2016-01-01

    Mg(2+) plays a vital role in platelet function, but despite implications for life-threatening conditions such as stroke or myocardial infarction, the mechanisms controlling [Mg(2+)]i in megakaryocytes (MKs) and platelets are largely unknown. Transient receptor potential melastatin-like 7 channel (TRPM7) is a ubiquitous, constitutively active cation channel with a cytosolic α-kinase domain that is critical for embryonic development and cell survival. Here we report that impaired channel function of TRPM7 in MKs causes macrothrombocytopenia in mice (Trpm7(fl/fl-Pf4Cre)) and likely in several members of a human pedigree that, in addition, suffer from atrial fibrillation. The defect in platelet biogenesis is mainly caused by cytoskeletal alterations resulting in impaired proplatelet formation by Trpm7(fl/fl-Pf4Cre) MKs, which is rescued by Mg(2+) supplementation or chemical inhibition of non-muscle myosin IIA heavy chain activity. Collectively, our findings reveal that TRPM7 dysfunction may cause macrothrombocytopenia in humans and mice. PMID:27020697

  4. Defects in TRPM7 channel function deregulate thrombopoiesis through altered cellular Mg2+ homeostasis and cytoskeletal architecture

    PubMed Central

    Stritt, Simon; Nurden, Paquita; Favier, Remi; Favier, Marie; Ferioli, Silvia; Gotru, Sanjeev K.; van Eeuwijk, Judith M M.; Schulze, Harald; Nurden, Alan T.; Lambert, Michele P.; Turro, Ernest; Burger-Stritt, Stephanie; Matsushita, Masayuki; Mittermeier, Lorenz; Ballerini, Paola; Zierler, Susanna; Laffan, Michael A.; Chubanov, Vladimir; Gudermann, Thomas; Nieswandt, Bernhard; Braun, Attila

    2016-01-01

    Mg2+ plays a vital role in platelet function, but despite implications for life-threatening conditions such as stroke or myocardial infarction, the mechanisms controlling [Mg2+]i in megakaryocytes (MKs) and platelets are largely unknown. Transient receptor potential melastatin-like 7 channel (TRPM7) is a ubiquitous, constitutively active cation channel with a cytosolic α-kinase domain that is critical for embryonic development and cell survival. Here we report that impaired channel function of TRPM7 in MKs causes macrothrombocytopenia in mice (Trpm7fl/fl-Pf4Cre) and likely in several members of a human pedigree that, in addition, suffer from atrial fibrillation. The defect in platelet biogenesis is mainly caused by cytoskeletal alterations resulting in impaired proplatelet formation by Trpm7fl/fl-Pf4Cre MKs, which is rescued by Mg2+ supplementation or chemical inhibition of non-muscle myosin IIA heavy chain activity. Collectively, our findings reveal that TRPM7 dysfunction may cause macrothrombocytopenia in humans and mice. PMID:27020697

  5. 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.

  6. Hox Targets and Cellular Functions

    PubMed Central

    Sánchez-Herrero, Ernesto

    2013-01-01

    Hox genes are a group of genes that specify structures along the anteroposterior axis in bilaterians. Although in many cases they do so by modifying a homologous structure with a different (or no) Hox input, there are also examples of Hox genes constructing new organs with no homology in other regions of the body. Hox genes determine structures though the regulation of targets implementing cellular functions and by coordinating cell behavior. The genetic organization to construct or modify a certain organ involves both a genetic cascade through intermediate transcription factors and a direct regulation of targets carrying out cellular functions. In this review I discuss new data from genome-wide techniques, as well as previous genetic and developmental information, to describe some examples of Hox regulation of different cell functions. I also discuss the organization of genetic cascades leading to the development of new organs, mainly using Drosophila melanogaster as the model to analyze Hox function. PMID:24490109

  7. Muscle disuse alters skeletal muscle contractile function at the molecular and cellular levels in older adult humans in a sex-specific manner

    PubMed Central

    Callahan, Damien M; Miller, Mark S; Sweeny, Andrew P; Tourville, Timothy W; Slauterbeck, James R; Savage, Patrick D; Maugan, David W; Ades, Philip A; Beynnon, Bruce D; Toth, Michael J

    2014-01-01

    Physical inactivity that accompanies ageing and disease may hasten disability by reducing skeletal muscle contractility. To characterize skeletal muscle functional adaptations to muscle disuse, we compared contractile performance at the molecular, cellular and whole-muscle levels in healthy active older men and women (n = 15) and inactive older men and women with advanced-stage, symptomatic knee osteoarthritis (OA) (n = 16). OA patients showed reduced (P < 0.01) knee extensor function. At the cellular level, single muscle fibre force production was reduced in OA patients in myosin heavy chain (MHC) I and IIA fibres (both P < 0.05) and differences in IIA fibres persisted after adjustments for fibre cross-sectional area (P < 0.05). Although no group differences in contractile velocity or power output were found for any fibre type, sex was found to modify the effect of OA, with a reduction in MHC IIA power output and a trend towards reduced shortening velocity in women, but increases in both variables in men (P < 0.05 and P = 0.07, respectively). At the molecular level, these adaptations in MHC IIA fibre function were explained by sex-specific differences (P ≤ 0.05) in myosin–actin cross-bridge kinetics. Additionally, cross-bridge kinetics were slowed in MHC I fibres in OA patients (P < 0.01), attributable entirely to reductions in women with knee OA (P < 0.05), a phenotype that could be reproduced in vitro by chemical modification of protein thiol residues. Our results identify molecular and cellular functional adaptations in skeletal muscle that may contribute to reduced physical function with knee OA-associated muscle disuse, with sex-specific differences that may explain a greater disposition towards disability in women. PMID:25038243

  8. Cellular Alterations in Shock and Ischemia and Their Correction.

    ERIC Educational Resources Information Center

    Chaudry, Irshad H.

    1985-01-01

    Reviews recent advances in cellular alterations in shock to help physicians and physiologists keep abreast of current research. Specifically addresses changes occurring as a result of hemorrhagic shock and possible ways such lesions could be corrected. (DH)

  9. [Photodynamic modulation of cellular functions].

    PubMed

    Li, Yuan; Jiang, Hong-Ning; Cui, Zong-Jie

    2016-08-25

    Photodynamic action, due to the rather limited lifetime (1 μs) and effective reactive distance of singlet oxygen (< 10 nm), could subcellular-specifically regulate different cellular functions. Photodynamic action could activate permanently cholecystokinin (CCK) 1 receptors, and sensitize or desensitize other G protein-coupled receptors. The emergence in recent years of genetically- encoded protein photosensitisers has enabled more precisely-targeted photodynamic modulation of subcellular organelles and functional proteins. Protein photosensitisers (such as KillerRed, miniSOG or SOPP) expressed on the plasma membrane, mitochondria, lysosomes or endoplasmic reticulum can modulate photodynamically subcellular functions and fine-tune protein activity by targeted photooxidation. With the newly emerged active illumination technique, simultaneous photodynamic action localized at multiple sites is now possible, and the contribution of subcellular regions to the whole cell or individual cells to a cell cluster could be quantitated. Photodynamic action with protein photosensitiser will be a powerful tool for nano-manipulation in cell physiology research. PMID:27546513

  10. Mutations in human C2CD3 cause skeletal dysplasia and provide new insights into phenotypic and cellular consequences of altered C2CD3 function.

    PubMed

    Cortés, Claudio R; McInerney-Leo, Aideen M; Vogel, Ida; Rondón Galeano, Maria C; Leo, Paul J; Harris, Jessica E; Anderson, Lisa K; Keith, Patricia A; Brown, Matthew A; Ramsing, Mette; Duncan, Emma L; Zankl, Andreas; Wicking, Carol

    2016-01-01

    Ciliopathies are a group of genetic disorders caused by defective assembly or dysfunction of the primary cilium, a microtubule-based cellular organelle that plays a key role in developmental signalling. Ciliopathies are clinically grouped in a large number of overlapping disorders, including the orofaciodigital syndromes (OFDS), the short rib polydactyly syndromes and Jeune asphyxiating thoracic dystrophy. Recently, mutations in the gene encoding the centriolar protein C2CD3 have been described in two families with a new sub-type of OFDS (OFD14), with microcephaly and cerebral malformations. Here we describe a third family with novel compound heterozygous C2CD3 mutations in two fetuses with a different clinical presentation, dominated by skeletal dysplasia with no microcephaly. Analysis of fibroblast cultures derived from one of these fetuses revealed a reduced ability to form cilia, consistent with previous studies in C2cd3-mutant mouse and chicken cells. More detailed analyses support a role for C2CD3 in basal body maturation; but in contrast to previous mouse studies the normal recruitment of the distal appendage protein CEP164 suggests that this protein is not sufficient for efficient basal body maturation and subsequent axonemal extension in a C2CD3-defective background. PMID:27094867

  11. Mutations in human C2CD3 cause skeletal dysplasia and provide new insights into phenotypic and cellular consequences of altered C2CD3 function

    PubMed Central

    Cortés, Claudio R.; McInerney-Leo, Aideen M.; Vogel, Ida; Rondón Galeano, Maria C.; Leo, Paul J.; Harris, Jessica E.; Anderson, Lisa K.; Keith, Patricia A.; Brown, Matthew A.; Ramsing, Mette; Duncan, Emma L.; Zankl, Andreas; Wicking, Carol

    2016-01-01

    Ciliopathies are a group of genetic disorders caused by defective assembly or dysfunction of the primary cilium, a microtubule-based cellular organelle that plays a key role in developmental signalling. Ciliopathies are clinically grouped in a large number of overlapping disorders, including the orofaciodigital syndromes (OFDS), the short rib polydactyly syndromes and Jeune asphyxiating thoracic dystrophy. Recently, mutations in the gene encoding the centriolar protein C2CD3 have been described in two families with a new sub-type of OFDS (OFD14), with microcephaly and cerebral malformations. Here we describe a third family with novel compound heterozygous C2CD3 mutations in two fetuses with a different clinical presentation, dominated by skeletal dysplasia with no microcephaly. Analysis of fibroblast cultures derived from one of these fetuses revealed a reduced ability to form cilia, consistent with previous studies in C2cd3-mutant mouse and chicken cells. More detailed analyses support a role for C2CD3 in basal body maturation; but in contrast to previous mouse studies the normal recruitment of the distal appendage protein CEP164 suggests that this protein is not sufficient for efficient basal body maturation and subsequent axonemal extension in a C2CD3-defective background. PMID:27094867

  12. ALTERATIONS IN MATERNAL-FETAL CELLULAR TRAFFICKING AFTER FETAL SURGERY

    PubMed Central

    Saadai, Payam; Lee, Tzong-Hae; Bautista, Geoanna; Gonzales, Kelly D.; Nijagal, Amar; Busch, Michael P.; Kim, CJ; Romero, Roberto; Lee, Hanmin; Hirose, Shinjiro; Rand, Larry; Miniati, Douglas; Farmer, Diana L.; MacKenzie, Tippi C.

    2012-01-01

    Background/Purpose Bi-directional trafficking of cells between the mother and the fetus is routine in pregnancy and a component of maternal-fetal tolerance. Changes in fetal-to-maternal cellular trafficking have been reported in prenatal complications, but maternal-to-fetal trafficking has never been studied in the context of fetal intervention. We hypothesized that patients undergoing open fetal surgery would have altered maternal-fetal cellular trafficking. Methods Cellular trafficking was analyzed in patients with myelomeningocele (MMC) who underwent open fetal surgical repair (n=5), MMC patients who had routine postnatal repair (n=6), and normal term patients (n=9). As a control for the fetal operation, trafficking was also analyzed in patients who were delivered by an ex utero intrapartum treatment (EXIT) procedure (n=6). Microchimerism in maternal and cord blood was determined using quantitative real-time PCR for non-shared alleles. Results Maternal-to-fetal trafficking was significantly increased in patients who underwent open fetal surgery for MMC compared to normal controls, postnatal MMC repair, and EXIT patients. There were no differences in fetal-to-maternal cell trafficking between groups. Conclusion Patients undergoing open fetal surgery for MMC have elevated levels of maternal microchimerism. These results suggest altered trafficking and/or increased proliferation of maternal cells in fetal blood and may have important implications for preterm labor. PMID:22703775

  13. Neurological and behavioral abnormalities, ventricular dilatation, altered cellular functions, inflammation, and neuronal injury in brains of mice due to common, persistent, parasitic infection

    PubMed Central

    Hermes, Gretchen; Ajioka, James W; Kelly, Krystyna A; Mui, Ernest; Roberts, Fiona; Kasza, Kristen; Mayr, Thomas; Kirisits, Michael J; Wollmann, Robert; Ferguson, David JP; Roberts, Craig W; Hwang, Jong-Hee; Trendler, Toria; Kennan, Richard P; Suzuki, Yasuhiro; Reardon, Catherine; Hickey, William F; Chen, Lieping; McLeod, Rima

    2008-01-01

    Background Worldwide, approximately two billion people are chronically infected with Toxoplasma gondii with largely unknown consequences. Methods To better understand long-term effects and pathogenesis of this common, persistent brain infection, mice were infected at a time in human years equivalent to early to mid adulthood and studied 5–12 months later. Appearance, behavior, neurologic function and brain MRIs were studied. Additional analyses of pathogenesis included: correlation of brain weight and neurologic findings; histopathology focusing on brain regions; full genome microarrays; immunohistochemistry characterizing inflammatory cells; determination of presence of tachyzoites and bradyzoites; electron microscopy; and study of markers of inflammation in serum. Histopathology in genetically resistant mice and cytokine and NRAMP knockout mice, effects of inoculation of isolated parasites, and treatment with sulfadiazine or αPD1 ligand were studied. Results Twelve months after infection, a time equivalent to middle to early elderly ages, mice had behavioral and neurological deficits, and brain MRIs showed mild to moderate ventricular dilatation. Lower brain weight correlated with greater magnitude of neurologic abnormalities and inflammation. Full genome microarrays of brains reflected inflammation causing neuronal damage (Gfap), effects on host cell protein processing (ubiquitin ligase), synapse remodeling (Complement 1q), and also increased expression of PD-1L (a ligand that allows persistent LCMV brain infection) and CD 36 (a fatty acid translocase and oxidized LDL receptor that mediates innate immune response to beta amyloid which is associated with pro-inflammation in Alzheimer's disease). Immunostaining detected no inflammation around intra-neuronal cysts, practically no free tachyzoites, and only rare bradyzoites. Nonetheless, there were perivascular, leptomeningeal inflammatory cells, particularly contiguous to the aqueduct of Sylvius and hippocampus

  14. Asplatin enhances drug efficacy by altering the cellular response.

    PubMed

    Cheng, Qinqin; Shi, Hongdong; Wang, Hongxia; Wang, Jun; Liu, Yangzhong

    2016-07-13

    Aspirin, a widely used anti-inflammatory drug, has been shown to be effective for the prevention and remission of cancers (Science, 2012, 337(21) 1471-1473). Asplatin, a Pt(iv) prodrug of cisplatin with the ligation of aspirin (c,c,t-[PtCl2(NH3)2(OH)(aspirin)]), demonstrates significantly higher cytotoxicity than cisplatin towards tumor cells and almost fully overcomes the drug resistance of cisplatin resistant cells. In this work, we have studied the molecular mechanism of asplatin by investigating the cellular response to this compound in order to understand the prominent inhibitory effect on the proliferation of cancer cells. The apoptosis analyses and the related gene expression measurements show that aspirin released from asplatin significantly modulates the cellular response to the platinum agent. Asplatin promotes the apoptosis via the BCL-2 associated mitochondrial pathway. The down-regulation of BCL-2 along with the up-regulation of BAX and BAK enhances the mitochondrial outer membrane permeability, resulting in the cytochrome c release from mitochondria into the cytosol. This event promotes the apoptosis by activation of caspase processing. Consequently, the ligation of aspirin significantly enhances the drug efficacy of the platinum complex in the low micromolar range. The alteration of the cellular response is probably responsible for the circumvention of the cisplatin resistance by asplatin. These results provide an insight into the mechanism of asplatin and provide information for designing new classic platinum drugs. PMID:27125788

  15. Skeletal muscle plasticity: cellular and molecular responses to altered physical activity paradigms

    NASA Technical Reports Server (NTRS)

    Baldwin, Kenneth M.; Haddad, Fadia

    2002-01-01

    The goal of this article is to examine our current understanding of the chain of events known to be involved in the adaptive process whereby specific genes and their protein products undergo altered expression; specifically, skeletal muscle adaptation in response to altered loading states will be discussed, with a special focus on the regulation of the contractile protein, myosin heavy chain gene expression. This protein, which is both an important structural and regulatory protein comprising the contractile apparatus, can be expressed as different isoforms, thereby having an impact on the functional diversity of the muscle. Because the regulation of the myosin gene family is under the control of a complex set of processes including, but not limited to, activity, hormonal, and metabolic factors, this protein will serve as a cellular "marker" for studies of muscle plasticity in response to various mechanical perturbations in which the quantity and type of myosin isoform, along with other important cellular proteins, are altered in expression.

  16. Cellular Mechanisms Controlling Caspase Activation and Function

    PubMed Central

    Parrish, Amanda B.; Freel, Christopher D.; Kornbluth, Sally

    2013-01-01

    Caspases are the primary drivers of apoptotic cell death, cleaving cellular proteins that are critical for dismantling the dying cell. Initially translated as inactive zymogenic precursors, caspases are activated in response to a variety of cell death stimuli. In addition to factors required for their direct activation (e.g., dimerizing adaptor proteins in the case of initiator caspases that lie at the apex of apoptotic signaling cascades), caspases are regulated by a variety of cellular factors in a myriad of physiological and pathological settings. For example, caspases may be modified posttranslationally (e.g., by phosphorylation or ubiquitylation) or through interaction of modulatory factors with either the zymogenic or active form of a caspase, altering its activation and/or activity. These regulatory events may inhibit or enhance enzymatic activity or may affect activity toward particular cellular substrates. Finally, there is emerging literature to suggest that caspases can participate in a variety of cellular processes unrelated to apoptotic cell death. In these settings, it is particularly important that caspases are maintained under stringent control to avoid inadvertent cell death. It is likely that continued examination of these processes will reveal new mechanisms of caspase regulation with implications well beyond control of apoptotic cell death. PMID:23732469

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

    SciTech Connect

    Kelly, Catriona; 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 mM 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.

  18. Dolichol alters brain membrane functions

    SciTech Connect

    Sun, G.Y.; Sun, A.Y.; Schroeder, F.; Wood, G.; Strong, R.

    1986-03-05

    It has been well demonstrated that there is a direct correlation between increase in dolichol level in brain and aging. An abnormally high level of dolichol was found in brain tissue of patients with pathological aging disorders. The aim of this study is to examine the physiological significance of dolichol affecting membrane transport activity and phospholipid acyl group turnover. Dolichol added to synaptic plasma membranes resulted in a biphasic effect on (Na/sup +/, K/sup +/)-ATPase, i.e., an enhancement of activity at low concentrations (5 ..mu..g/125 mg protein) and an inhibition of activity at high concentrations (40-100 ..mu..g). To probe the membrane acyl group turnover, the incorporation of (/sup 14/C)-arachidonate into plasma membrane phospholipids was examined in the presence and absence of dolichol. Dolichol elicited an increase in the incorporation of label into phospholipids. However, the effects varied depending on whether BSA is present. In the absence of BSA, the increase in labeling of phosphatidylinositols is higher than that of phosphatidylcholines. These results suggest that dolichols, when inserted into membranes, may alter membrane functions.

  19. Functional and cellular adaptations of rodent skeletal muscle to weightlessness

    NASA Technical Reports Server (NTRS)

    Caiozzo, Vincent J.; Haddad, Fadia; Baker, Michael J.; Baldwin, Kenneth M.

    1995-01-01

    This paper describes the affects of microgravity upon three key cellular levels (functional, protein, and mRNA) that are linked to one another. It is clear that at each of these levels, microgravity produces rapid and substantial alterations. One of the key challenges facing the life science community is the development of effective countermeasures that prevent the loss of muscle function as described in this paper. The development of optimal countermeasures, however, awaits a clearer understanding of events occurring at the levels of transcription, translation, and degradation.

  20. Shaping cellular form and function by autophagy.

    PubMed

    Bamber, Bruce A; Rowland, Aaron M

    2006-01-01

    In addition to its familiar role in non-selective bulk degradation of cellular material, autophagy can also bring about specific changes in the structure and function of cells. Autophagy has been proposed to operate in a substrate-selective mode to carry out this function, although evidence to demonstrate selectivity has been lacking. A recent study of synapse formation in the nervous system of the nematode Caenorhabditis elegans now provides experimental evidence for substrate-selective autophagy. Synapses form when presynaptic cells contact their postsynaptic partners during development. This contact induces the assembly of synaptically-localized protein complexes in the postsynaptic cell that contain scaffolding proteins and neurotransmitter receptors. When presynaptic contact was blocked, autophagy in the postsynaptic cell was induced. Substrate selectivity was evident in this system: the gamma-aminobutyric acid type A receptor (GABA(A) receptor), an integral-membrane neurotransmitter receptor, trafficked from the cell surface to autophagosomes. By contrast, the acetylcholine receptor, a structurally-similar neurotransmitter receptor, remained on the cell surface. This result provides experimental support for the idea that autophagy can bring about changes in cell structure and behavior by degrading specific cellular proteins, particularly cell surface receptors that are often important for regulating cell growth, differentiation and function. PMID:16874044

  1. Cellular responses to HSV-1 infection are linked to specific types of alterations in the host transcriptome.

    PubMed

    Hu, Benxia; Li, Xin; Huo, Yongxia; Yu, Yafen; Zhang, Qiuping; Chen, Guijun; Zhang, Yaping; Fraser, Nigel W; Wu, Dongdong; Zhou, Jumin

    2016-01-01

    Pathogen invasion triggers a number of cellular responses and alters the host transcriptome. Here we report that the type of changes to cellular transcriptome is related to the type of cellular functions affected by lytic infection of Herpes Simplex Virus type I in Human primary fibroblasts. Specifically, genes involved in stress responses and nuclear transport exhibited mostly changes in alternative polyadenylation (APA), cell cycle genes showed mostly alternative splicing (AS) changes, while genes in neurogenesis, rarely underwent these changes. Transcriptome wide, the infection resulted in 1,032 cases of AS, 161 incidences of APA, 1,827 events of isoform changes, and up regulation of 596 genes and down regulations of 61 genes compared to uninfected cells. Thus, these findings provided important and specific links between cellular responses to HSV-1 infection and the type of alterations to the host transcriptome, highlighting important roles of RNA processing in virus-host interactions. PMID:27354008

  2. Cellular responses to HSV-1 infection are linked to specific types of alterations in the host transcriptome

    PubMed Central

    Hu, Benxia; Li, Xin; Huo, Yongxia; Yu, Yafen; Zhang, Qiuping; Chen, Guijun; Zhang, Yaping; Fraser, Nigel W.; Wu, Dongdong; Zhou, Jumin

    2016-01-01

    Pathogen invasion triggers a number of cellular responses and alters the host transcriptome. Here we report that the type of changes to cellular transcriptome is related to the type of cellular functions affected by lytic infection of Herpes Simplex Virus type I in Human primary fibroblasts. Specifically, genes involved in stress responses and nuclear transport exhibited mostly changes in alternative polyadenylation (APA), cell cycle genes showed mostly alternative splicing (AS) changes, while genes in neurogenesis, rarely underwent these changes. Transcriptome wide, the infection resulted in 1,032 cases of AS, 161 incidences of APA, 1,827 events of isoform changes, and up regulation of 596 genes and down regulations of 61 genes compared to uninfected cells. Thus, these findings provided important and specific links between cellular responses to HSV-1 infection and the type of alterations to the host transcriptome, highlighting important roles of RNA processing in virus-host interactions. PMID:27354008

  3. Natural Products as Tools for Defining How Cellular Metabolism Influences Cellular Immune and Inflammatory Function during Chronic Infection

    PubMed Central

    Lovelace, Erica S.; Polyak, Stephen J.

    2015-01-01

    Chronic viral infections like those caused by hepatitis C virus (HCV) and human immunodeficiency virus (HIV) cause disease that establishes an ongoing state of chronic inflammation. While there have been tremendous improvements towards curing HCV with directly acting antiviral agents (DAA) and keeping HIV viral loads below detection with antiretroviral therapy (ART), there is still a need to control inflammation in these diseases. Recent studies indicate that many natural products like curcumin, resveratrol and silymarin alter cellular metabolism and signal transduction pathways via enzymes such as adenosine monophosphate kinase (AMPK) and mechanistic target of rapamycin (mTOR), and these pathways directly influence cellular inflammatory status (such as NF-κB) and immune function. Natural products represent a vast toolkit to dissect and define how cellular metabolism controls cellular immune and inflammatory function. PMID:26633463

  4. Myosin VI: cellular functions and motor properties.

    PubMed Central

    Roberts, Rhys; Lister, Ida; Schmitz, Stephan; Walker, Matthew; Veigel, Claudia; Trinick, John; Buss, Folma; Kendrick-Jones, John

    2004-01-01

    Myosin VI has been localized in membrane ruffles at the leading edge of cells, at the trans-Golgi network compartment of the Golgi complex and in clathrin-coated pits or vesicles, indicating that it functions in a wide variety of intracellular processes. Myosin VI moves along actin filaments towards their minus end, which is the opposite direction to all of the other myosins so far studied (to our knowledge), and is therefore thought to have unique properties and functions. To investigate the cellular roles of myosin VI, we identified various myosin VI binding partners and are currently characterizing their interactions within the cell. As an alternative approach, we have expressed and purified full-length myosin VI and studied its in vitro properties. Previous studies assumed that myosin VI was a dimer, but our biochemical, biophysical and electron microscopic studies reveal that myosin VI can exist as a stable monomer. We observed, using an optical tweezers force transducer, that monomeric myosin VI is a non-processive motor which, despite a relatively short lever arm, generates a large working stroke of 18 nm. Whether monomer and/or dimer forms of myosin VI exist in cells and their possible functions will be discussed. PMID:15647169

  5. Cellular functions of programmed cell death 5.

    PubMed

    Li, Ge; Ma, Dalong; Chen, Yingyu

    2016-04-01

    Programmed cell death 5 (PDCD5) was originally identified as an apoptosis-accelerating protein that is widely expressed and has been well conserved during the process of evolution. PDCD5 has complex biological functions, including programmed cell death and immune regulation. It can accelerate apoptosis in different type of cells in response to different stimuli. During this process, PDCD5 rapidly translocates from the cytoplasm to the nucleus. PDCD5 regulates the activities of TIP60, HDAC3, MDM2 and TP53 transcription factors. These proteins form part of a signaling network that is disrupted in most, if not all, cancer cells. Recent evidence suggests that PDCD5 participates in immune regulation by promoting regulatory T cell function via the PDCD5-TIP60-FOXP3 pathway. The stability and expression of PDCD5 are finely regulated by other molecules, such as NF-κB p65, OTUD5, YAF2 and DNAJB1. PDCD5 is phosphorylated by CK2 at Ser119, which is required for nuclear translocation in response to genotoxic stress. In this review, we describe what is known about PDCD5 and its cellular functions. PMID:26775586

  6. Cytarabine induced cerebellar neuronal damage in juvenile rat: correlating neurobehavioral performance with cellular and genetic alterations.

    PubMed

    Patel, Ronak S; Rachamalla, Mahesh; Chary, Namoju R; Shera, Firdos Y; Tikoo, Kulbhushan; Jena, Gopabandhu

    2012-03-11

    Cytosine arabinoside (Ara-C), a pyrimidine analogue induces cerebellar dysfunction and behavioral abnormalities. Although many in vitro experiments have been conducted in the past demonstrating the lethal potential of Ara-C to cerebellar neurons, there is a paucity of literature available regarding the effects of Ara-C on the cellular and genetic material of cerebellum and its subsequent influence on the neurobehavioral performance in vivo. Rats were treated with Ara-C at the dose levels 50, 100 and 200mg/kg/day for 5 and 14 days by intraperitoneal (i.p.) route. Endpoints of the evaluation included food and water intake, body and organ weight, behavioral parameters, histopathology, oxidative stress, DNA damage, apoptosis, expression of p53, caspase-3 and calbindin D-28K (calbindin) as well as histone acetylation and methylation. Ara-C treatment for 14 days significantly decreased the food and water intake, body weight gain and brain weight in rat as compared to the control. Alterations in various behavioral parameters were observed, indicating the impaired cerebellar function. Further, cellular abnormalities in the cerebellum such as Purkinje cell misalignment and granule cell cytotoxicity were observed. Positive correlation was observed between Ara-C induced disturbance in the motor performance and the Purkinje cell loss in rat cerebellum. Moreover, Ara-C treatment significantly increased the oxidative stress, DNA damage, TUNEL positive cells, p53 and caspase-3 positive cells in the rat cerebellum. Unlike short-term treatment, long-term Ara-C treatment significantly reduced calbindin expression in the cerebellum. Apart from this, 14 days Ara-C treatment led to significant alterations in the histone acetylation and methylation in the cerebellum, while in 5 days treatment no such alterations were observed. Present results indicated that Ara-C, by inducing oxidative stress mediated DNA damage, executes neuronal apoptosis which is accompanied by an increase in the p53

  7. Nicotinic alteration of functional thalamocortical topography.

    PubMed

    Lee, Charles C; Yanagawa, Yuchio; Imaizumi, Kazuo

    2015-08-19

    The thalamocortical pathways form highly topographic connections from the primary sensory thalamic nuclei to the primary cortical areas. The synaptic properties of these thalamocortical connections are modifiable by activation from various neuromodulators, such as acetylcholine. Cholinergic activation can alter functional properties in both the developing and the mature nervous system. Moreover, environmental factors, such as nicotine, can activate these receptors, although the circuit-level alterations resulting from such nicotinic activation of sensory neural circuits remain largely unexplored. Therefore, we examined alterations to the functional topography of thalamocortical circuits in the developing sensory pathways of the mouse. Photostimulation by uncaging of glutamate was used to map these functional thalamocortical alterations in response to nicotinic receptor activation. As a result, we found that activation of forebrain nicotinic acetylcholine receptors results in an expansion and enhancement of functional thalamocortical topographies as assessed in brain slice preparations using laser-scanning photostimulation by uncaging of glutamate. These physiological changes were correlated with the neuroanatomical expression of nicotinic acetylcholine receptor subtypes (α7 and β2). These circuit-level alterations may provide a neural substrate underlying the plastic development and reshaping of thalamocortical circuitry in response to nicotinic receptor activation. PMID:26164456

  8. Physical effects at the cellular level under altered gravity conditions

    NASA Astrophysics Data System (ADS)

    Todd, Paul

    Several modifications of differentiated functions of animal cells cultivated in vitro have been reported when cultures have been exposed to increased or decreased inertial acceleration fields by centrifugation, clinorotation, and orbital space flight. Variables modified by clinorotation conditions include inertial acceleration, convection, hydrostatic pressure, sedimentation, and shear stress, which also affect transport processes in the extracellular chemical environment. Autocrine, paracrine and endocrine substances, to which cells are responsive via specific receptors, are usually transported in vitro (and possibly in certain embryos) by convection and in vivo by a circulatory system or ciliary action. Increased inertial acceleration increases convective flow, while microgravity nearly abolishes it. In the latter case the extracellular transport of macromolecules is governed by diffusion. By making certain assumptions it is possible to calculate the Peclet number, the ratio of convective transport to diffusive transport. Some, but not all, responses of cells in vitro to modified inertial environments could be manifestations of modified extracellular convective flow.

  9. Restriction of Receptor Movement Alters Cellular Response: Physical Force Sensing by EphA2

    SciTech Connect

    Salaita, Khalid; Nair, Pradeep M; Petit, Rebecca S; Neve, Richard M; Das, Debopriya; Gray, Joe W; Groves, Jay T

    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. Quantitative 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.

  10. Alterations in cellular metabolism modulate CD1d-mediated NKT-cell responses.

    PubMed

    Webb, Tonya J; Carey, Gregory B; East, James E; Sun, Wenji; Bollino, Dominique R; Kimball, Amy S; Brutkiewicz, Randy R

    2016-08-01

    Natural killer T (NKT) cells play a critical role in the host's innate immune response. CD1d-mediated presentation of glycolipid antigens to NKT cells has been established; however, the mechanisms by which NKT cells recognize infected or cancerous cells remain unclear. 5(')-AMP activated protein kinase (AMPK) is a master regulator of lipogenic pathways. We hypothesized that activation of AMPK during infection and malignancy could alter the repertoire of antigens presented by CD1d and serve as a danger signal to NKT cells. In this study, we examined the effect of alterations in metabolism on CD1d-mediated antigen presentation to NKT cells and found that an infection with lymphocytic choriomeningitis virus rapidly increased CD1d-mediated antigen presentation. Hypoxia inducible factors (HIF) enhance T-cell effector functions during infection, therefore antigen presenting cells pretreated with pharmacological agents that inhibit glycolysis, induce HIF and activate AMPK were assessed for their ability to induce NKT-cell responses. Pretreatment with 2-deoxyglucose, cobalt chloride, AICAR and metformin significantly enhanced CD1d-mediated NKT-cell activation. In addition, NKT cells preferentially respond to malignant B cells and B-cell lymphomas express HIF-1α. These data suggest that targeting cellular metabolism may serve as a novel means of inducing innate immune responses. PMID:27297969

  11. Epstein-Barr virus growth/latency III program alters cellular microRNA expression

    SciTech Connect

    Cameron, Jennifer E. Fewell, Claire Yin, Qinyan McBride, Jane Wang Xia Lin Zhen

    2008-12-20

    The Epstein-Barr virus (EBV) is associated with lymphoid and epithelial cancers. Initial EBV infection alters lymphocyte gene expression, inducing cellular proliferation and differentiation as the virus transitions through consecutive latency transcription programs. Cellular microRNAs (miRNAs) are important regulators of signaling pathways and are implicated in carcinogenesis. The extent to which EBV exploits cellular miRNAs is unknown. Using micro-array analysis and quantitative PCR, we demonstrate differential expression of cellular miRNAs in type III versus type I EBV latency including elevated expression of miR-21, miR-23a, miR-24, miR-27a, miR-34a, miR-146a and b, and miR-155. In contrast, miR-28 expression was found to be lower in type III latency. The EBV-mediated regulation of cellular miRNAs may contribute to EBV signaling and associated cancers.

  12. Cellular Functions of Transient Receptor Potential channels

    PubMed Central

    Dadon, Daniela; Minke, Baruch

    2010-01-01

    Transient Receptor Potential channels are polymodal cellular sensors involved in a wide variety of cellular processes, mainly by increasing cellular Ca2+. In this review we focus on the roles of these channels in: i) cell death ii) proliferation and differentiation and iii) synaptic vesicle release. Cell death Ca2+ influx participates in apoptotic and necrotic cell death. The Ca2+ permeability and high sensitivity of part of these channels to oxidative/metabolic stress make them important participants in cell death. Several examples are given. Transient Receptor Potential Melastatin 2 is activated by H2O2, inducing cell death through an increase in cellular Ca2+ and activation of Poly ADP-Ribose Polymerase. Exposure of cultured cortical neurons to oxygen-glucose deprivation, in vitro, causes cell death via cation influx, mediated by Transient Receptor Potential Melastatin 7. Metabolic stress constitutively activates the Ca2+ permeable Transient Receptor Potential channels of Drosophila photoreceptor in the dark, potentially leading to retinal degeneration. Similar sensitivity to metabolic stress characterizes several mammalian Transient Receptor Potential Canonical channels. Proliferation and differentiation The rise in cytosolic Ca2+ induces cell growth, differentiation and proliferation via activation of several transcription factors. Activation a variety of store operated and Transient Receptor Potential channels cause a rise in cytosolic Ca2+, making these channels components involved in proliferation and differentiation. Synaptic vesicle release Transient Receptor Potential Melastatin 7 channels reside in synaptic vesicles and regulate neurotransmitter release by a mechanism that is not entirely clear. All the above features of Transient Receptor Potential channels make them crucial components in important, sometimes conflicting, cellular processes that still need to be explored. PMID:20399884

  13. Rejuvenating cellular respiration for optimizing respiratory function: targeting mitochondria.

    PubMed

    Agrawal, Anurag; Mabalirajan, Ulaganathan

    2016-01-15

    Altered bioenergetics with increased mitochondrial reactive oxygen species production and degradation of epithelial function are key aspects of pathogenesis in asthma and chronic obstructive pulmonary disease (COPD). This motif is not unique to obstructive airway disease, reported in related airway diseases such as bronchopulmonary dysplasia and parenchymal diseases such as pulmonary fibrosis. Similarly, mitochondrial dysfunction in vascular endothelium or skeletal muscles contributes to the development of pulmonary hypertension and systemic manifestations of lung disease. In experimental models of COPD or asthma, the use of mitochondria-targeted antioxidants, such as MitoQ, has substantially improved mitochondrial health and restored respiratory function. Modulation of noncoding RNA or protein regulators of mitochondrial biogenesis, dynamics, or degradation has been found to be effective in models of fibrosis, emphysema, asthma, and pulmonary hypertension. Transfer of healthy mitochondria to epithelial cells has been associated with remarkable therapeutic efficacy in models of acute lung injury and asthma. Together, these form a 3R model--repair, reprogramming, and replacement--for mitochondria-targeted therapies in lung disease. This review highlights the key role of mitochondrial function in lung health and disease, with a focus on asthma and COPD, and provides an overview of mitochondria-targeted strategies for rejuvenating cellular respiration and optimizing respiratory function in lung diseases. PMID:26566906

  14. Alpha-Synuclein Function and Dysfunction on Cellular Membranes

    PubMed Central

    Snead, David

    2014-01-01

    Alpha-synuclein is a small neuronal protein that is closely associated with the etiology of Parkinson's disease. Mutations in and alterations in expression levels of alpha-synuclein cause autosomal dominant early onset heredity forms of Parkinson's disease, and sporadic Parkinson's disease is defined in part by the presence of Lewy bodies and Lewy neurites that are composed primarily of alpha-synuclein deposited in an aggregated amyloid fibril state. The normal function of alpha-synuclein is poorly understood, and the precise mechanisms by which it leads to toxicity and cell death are also unclear. Although alpha-synuclein is a highly soluble, cytoplasmic protein, it binds to a variety of cellular membranes of different properties and compositions. These interactions are considered critical for at least some normal functions of alpha-synuclein, and may well play critical roles in both the aggregation of the protein and its mechanisms of toxicity. Here we review the known features of alpha-synuclein membrane interactions in the context of both the putative functions of the protein and of its pathological roles in disease. PMID:25548530

  15. Overexpression of p49/STRAP alters cellular cytoskeletal structure and gross anatomy in mice

    PubMed Central

    2014-01-01

    Background The protein p49/STRAP (SRFBP1) is a transcription cofactor of serum response factor (SRF) which regulates cytoskeletal and muscle-specific genes. Results Two conserved domains were found in the p49/STRAP protein. The SRF-binding domain was at its N-terminus and was highly conserved among mammalian species, xenopus and zebrafish. A BUD22 domain was found at its C-terminus in three sequence databases. The BUD22 domain was conserved among mammalian p49/STRAP proteins, and yeast cellular morphogenesis proteins, which is involved in ribosome biogenesis that affects growth rate and cell size. The endogenous p49/SRAP protein was localized mainly in the nucleus but also widely distributed in the cytoplasm, and was in close proximity to the actin. Transfected GFP-p49/STRAP protein co-localized with nucleolin within the nucleolus. Overexpression of p49/STRAP reduced actin content in cultured cells and resulted in smaller cell size versus control cells. Increased expression of p49/STRAP in transgenic mice resulted in newborns with malformations, which included asymmetric abdominal and thoracic cavities, and substantial changes in cardiac morphology. p49/STRAP altered the expression of certain muscle-specific genes, including that of the SRF gene, which is a key regulator of cardiac genes at the developmental, structural and maintenance level and has two SRE binding sites. Conclusions Since p49/STRAP is a co-factor of SRF, our data suggest that p49/STRAP likely regulates cell size and morphology through SRF target genes. The function of its BUD22 domain warrants further investigation. The observed increase in p49/STRAP expression during cellular aging may contribute to observed morphological changes in senescence. PMID:25183317

  16. Alteration of heme metabolism in a cellular model of Diamond-Blackfan anemia.

    PubMed

    Mercurio, Sonia; Aspesi, Anna; Silengo, Lorenzo; Altruda, Fiorella; Dianzani, Irma; Chiabrando, Deborah

    2016-04-01

    Diamond-Blackfan anemia (DBA) is a congenital pure red cell aplasia often associated with skeletal malformations. Mutations in ribosomal protein coding genes, mainly in RPS19, account for the majority of DBA cases. The molecular mechanisms underlying DBA pathogenesis are still not completely understood. Alternative spliced isoforms of FLVCR1 (feline leukemia virus subgroup C receptor 1) transcript coding for non-functional proteins have been reported in some DBA patients. Consistently, a phenotype very close to DBA has been described in animal models of FLVCR1 deficiency. FLVCR1 gene codes for two proteins: the plasma membrane heme exporter FLVCR1a and the mitochondrial heme exporter FLVCR1b. The coordinated expression of both FLVCR1 isoforms regulates an intracellular heme pool, necessary for proper expansion and differentiation of erythroid precursors. Here, we investigate the role of FLVCR1 isoforms in a cellular model of DBA. RPS19-downregulated TF1 cells show reduced FLVCR1a and FLVCR1b mRNA levels associated with heme overload. The downregulation of FLVCR1 isoforms affects cell cycle progression and apoptosis in differentiating K562 cells, a phenotype similar to DBA. Taken together, these data suggest that alteration of heme metabolism could play a role in the pathogenesis of DBA. PMID:26058344

  17. Cellular and molecular basis of cholinergic function

    SciTech Connect

    Dowdall, M.J.; Hawthorne, J.N.

    1987-01-01

    This book contains 105 selections. Some of the titles are: Functional correlates of brain nicotine receptors; Muscarinic receptor subclasses; Cholinergic innervation and levels of nerve growth factor and its mRNA in the central nervous system; Developmentally regulated neurontrophic activities of Torpedo electric organ tissue; and Association of a regulatory peptide with cholinergic neurons.

  18. Cellular functions of cardiolipin in yeast

    PubMed Central

    Joshi, Amit S.; Zhou, Jingming; Gohil, Vishal M.; Chen, Shuliang; Greenberg, Miriam L.

    2009-01-01

    Summary Cardiolipin (CL), the signature lipid of mitochondria, plays a critical role in mitochondrial function and biogenesis. The availability of yeast mutants blocked in CL synthesis has facilitated studies of the biological role of this lipid. Perturbation of CL synthesis leads to growth defects not only during respiratory growth but also under conditions in which respiration is not essential. CL was shown to play a role in mitochondrial protein import, cell wall biogenesis, aging and apoptosis, ceramide synthesis, and translation of electron transport chain components. The genetic disorder Barth syndrome (BTHS) is caused by mutations in the tafazzin gene resulting in decreased total CL levels, accumulation of monolysocardiolipin (MLCL), and decreased unsaturated fatty acyl species of CL. The variation in clinical presentation of BTHS indicates that other physiological factors play a significant role in modifying the phenotype resulting from tafazzin deficiency. Elucidating the functions of CL is expected to shed light on the role of this important lipid in BTHS and other disorders of mitochondrial dysfunction. PMID:18725250

  19. Cell Type Specific Analysis of Human Brain Transcriptome Data to Predict Alterations in Cellular Composition

    PubMed Central

    Xu, Xiaoxiao; Nehorai, Arye; Dougherty, Joseph

    2013-01-01

    The central nervous system (CNS) is composed of hundreds of distinct cell types, each expressing different subsets of genes from the genome. High throughput gene expression analysis of the CNS from patients and controls is a common method to screen for potentially pathological molecular mechanisms of psychiatric disease. One mechanism by which gene expression might be seen to vary across samples would be alterations in the cellular composition of the tissue. While the expressions of gene ‘markers’ for each cell type can provide certain information of cellularity, for many rare cell types markers are not well characterized. Moreover, if only small sets of markers are known, any substantial variation of a marker’s expression pattern due to experiment conditions would result in poor sensitivity and specificity. Here, our proposed method combines prior information from mice cell-specific transcriptome profiling experiments with co-expression network analysis, to select large sets of potential cell type-specific gene markers in a systematic and unbiased manner. The method is efficient and robust, and identifies sufficient markers for further cellularity analysis. We then employ the markers to analytically detect changing cellular composition in human brain. Application of our method to temporal human brain microarray data successfully detects changes in cellularity over time that roughly correspond to known epochs of human brain development. Furthermore, application of our method to human brain samples with the neurodevelopmental disorder of autism supports the interpretation that the changes in astrocytes and neurons might contribute to the disorder. PMID:25340014

  20. A computational model of skeletal muscle metabolism linking cellular adaptations induced by altered loading states to metabolic responses during exercise

    PubMed Central

    Dash, Ranjan K; DiBella, John A; Cabrera, Marco E

    2007-01-01

    Background The alterations in skeletal muscle structure and function after prolonged periods of unloading are initiated by the chronic lack of mechanical stimulus of sufficient intensity, which is the result of a series of biochemical and metabolic interactions spanning from cellular to tissue/organ level. Reduced activation of skeletal muscle alters the gene expression of myosin heavy chain isoforms to meet the functional demands of reduced mechanical load, which results in muscle atrophy and reduced capacity to process fatty acids. In contrast, chronic loading results in the opposite pattern of adaptations. Methods To quantify interactions among cellular and skeletal muscle metabolic adaptations, and to predict metabolic responses to exercise after periods of altered loading states, we develop a computational model of skeletal muscle metabolism. The governing model equations – with parameters characterizing chronic loading/unloading states- were solved numerically to simulate metabolic responses to moderate intensity exercise (WR ≤ 40% VO2 max). Results Model simulations showed that carbohydrate oxidation was 8.5% greater in chronically unloaded muscle compared with the loaded muscle (0.69 vs. 0.63 mmol/min), while fat oxidation was 7% higher in chronically loaded muscle (0.14 vs. 0.13 mmol/min), during exercise. Muscle oxygen uptake (VO2) and blood flow (Q) response times were 29% and 44% shorter in chronically loaded muscle (0.4 vs. 0.56 min for VO2 and 0.25 vs. 0.45 min for Q). Conclusion The present model can be applied to test complex hypotheses during exercise involving the integration and control of metabolic processes at various organizational levels (cellular to tissue) in individuals who have undergone periods of chronic loading or unloading. PMID:17448235

  1. Microgravity and Cellular Consequences in Lymphocyte Function

    NASA Technical Reports Server (NTRS)

    Pellis, Neal R.; Sundaresan, Alamelu

    2004-01-01

    Mammalian cells adapt to the environment of low gravity and express a series of responses, some possibly from direct effects on cells and others based on environmental conditions created by microgravity. Human lymphocytes in microgravity culture are functionally diminished in activation and locomotion. Both processes are integral to optimal immune response to fight pathogens. The NASA Rotating-wall vessel (RWV) is a well-accepted analog for microgravity culture on the ground. Gene array experiments and immunoblotting identified upstream events in human lymphocytes adapting to microgravity analog culture. Microgravity induces selective changes, many of which are cell membrane related. Results showed that upstream of PKC in the T cell activation cascade, PLC-gamma and LAT are significantly diminished. ZAP 70 which controls LAT activation is also down regulated in modeled microgravity. Thus events governing cell shape might warrant attention in microgravity conditions. The goal of this study is to delineate response suites that are consequential, direct or indirect effects of the microgravity environment and which of these are essential to lymphocytes

  2. Cellular function of neuropathy target esterase in lysophosphatidylcholine action

    SciTech Connect

    Vose, Sarah C.; Fujioka, Kazutoshi; Gulevich, Alex G.; Lin, Amy Y.; Holland, Nina T.; Casida, John E.

    2008-11-01

    Neuropathy target esterase (NTE) plays critical roles in embryonic development and maintenance of peripheral axons. It is a secondary target of some organophosphorus toxicants including analogs of insecticides and chemical warfare agents. Although the mechanistic role of NTE in vivo is poorly defined, it is known to hydrolyze lysophosphatidylcholine (LPC) in vitro and may protect cell membranes from cytotoxic accumulation of LPC. To determine the cellular function of NTE, Neuro-2a and COS-7 cells were transfected with a full-length human NTE-containing plasmid yielding recombinant NTE (rNTE). We find the same inhibitor sensitivity and specificity profiles for rNTE assayed with LPC or phenyl valerate (a standard NTE substrate) and that this correlation extends to the LPC hydrolases of human brain, lymphocytes and erythrocytes. All of these LPC hydrolases are therefore very similar to each other in respect to a conserved inhibitor binding site conformation. NTE is expressed in brain and lymphocytes and contributes to LPC hydrolase activities in these tissues. The enzyme or enzymes responsible for erythrocyte LPC hydrolase activity remain to be identified. We also show that rNTE protects Neuro-2a and COS-7 cells from exogenous LPC cytotoxicity. Expression of rNTE in Neuro-2a cells alters their phospholipid balance (analyzed by liquid chromatography-mass spectrometry with single ion monitoring) by lowering LPC-16:0 and LPC-18:0 and elevating glycerophosphocholine without a change in phosphatidylcholine-16:0/18:1 or 16:0/18:2. NTE therefore serves an important function in LPC homeostasis and action.

  3. Functional alterations in macrophages after hypoxia selection.

    PubMed

    Degrossoli, Adriana; Giorgio, Selma

    2007-01-01

    Regions of low oxygen tension are common features of inflamed and infected tissues and provide physiologic selective pressure for the expansion of cells with enhanced hypoxia tolerance. The aim of this study was to investigate whether macrophages resistant to death induced by hypoxia were accompanied by functional alterations. A mouse macrophage cell line (J774 cells) was used to obtain subpopulations of death-resistant macrophages induced by long-term exposure to severe hypoxia (<1% O(2)). The results indicated that exposing J774 macrophages to periods of severe hypoxia results in the selection of cells with phenotypes associated with the modulation of heat-shock protein 70 kDa (HSP70) expression, tumor necrosis factor-alpha (TNF-alpha), and nitric oxide (NO) production and reduced susceptibility to parasite Leishmania infection. Thus, we suggest that hypoxia-selected macrophages may influence the outcome of inflammation and infection. PMID:17202589

  4. Alterations in macrophage functions by environmental chemicals.

    PubMed Central

    Gardner, D E

    1984-01-01

    The establishment of infectious diseases is rarely entirely attributed to a single entity, but instead is the result of a primary stress and one or more secondary factors that interfere with homeostasis and the ability of the host to cope with the primary etiologic assault. Any environmental chemical that can suppress the normal functioning of the host's body defenses would be expected to increase the risk of the host to such diseases. Within the lung, the alveolar macrophages are the crucial elements responsible for defending the body against such airborne viable agents. The effects of inhaled gases and particulates on these defense cells are a major concern of the environmental health scientist since such chemicals have the capability of adversely affecting the integrity and functioning of these pulmonary defense cells. The objective of this report is to provide an overview that will improve our understanding of how a variety of environmental chemicals can alter the biochemical, physiological and immunological functioning of these cells. PMID:6376106

  5. Cellular senescence impact on immune cell fate and function.

    PubMed

    Vicente, Rita; Mausset-Bonnefont, Anne-Laure; Jorgensen, Christian; Louis-Plence, Pascale; Brondello, Jean-Marc

    2016-06-01

    Cellular senescence occurs not only in cultured fibroblasts, but also in undifferentiated and specialized cells from various tissues of all ages, in vitro and in vivo. Here, we review recent findings on the role of cellular senescence in immune cell fate decisions in macrophage polarization, natural killer cell phenotype, and following T-lymphocyte activation. We also introduce the involvement of the onset of cellular senescence in some immune responses including T-helper lymphocyte-dependent tissue homeostatic functions and T-regulatory cell-dependent suppressive mechanisms. Altogether, these data propose that cellular senescence plays a wide-reaching role as a homeostatic orchestrator. PMID:26910559

  6. Chronic hepcidin induction causes hyposideremia and alters the pattern of cellular iron accumulation in hemochromatotic mice.

    PubMed

    Viatte, Lydie; Nicolas, Gaël; Lou, Dan-Qing; Bennoun, Myriam; Lesbordes-Brion, Jeanne-Claire; Canonne-Hergaux, François; Schönig, Kai; Bujard, Hermann; Kahn, Axel; Andrews, Nancy C; Vaulont, Sophie

    2006-04-01

    We report the generation of a tetracycline-regulated (Tet ON) transgenic mouse model for acute and chronic expression of the iron regulatory peptide hepcidin in the liver. We demonstrate that short-term and long-term tetracycline-dependent activation of hepcidin in adult mice leads to hypoferremia and iron-limited erythropoiesis, respectively. This clearly establishes the key role of hepcidin in regulating the extracellular iron concentration. We previously demonstrated that, when expressed early in fetal development, constitutive transgenic hepcidin expression prevented iron accumulation in an Hfe-/- mouse model of hemochromatosis. We now explore the effect of chronic hepcidin expression in adult Hfe-/- mice that have already developed liver iron overload. We demonstrate that induction of chronic hepcidin expression in 2-month-old Hfe-/- mice alters their pattern of cellular iron accumulation, leading to increased iron in tissue macrophages and duodenal cells but less iron in hepatocytes. These hepcidin-induced changes in the pattern of cellular iron accumulation are associated with decreased expression of the iron exporter ferroportin in macrophages but no detectable alteration of ferroportin expression in the hepatocytes. We speculate that this change in iron homeostasis could offer a therapeutic advantage by protecting against damage to parenchymal cells. PMID:16339398

  7. Computer Modeling of the Earliest Cellular Structures and Functions

    NASA Technical Reports Server (NTRS)

    Pohorille, Andrew; Chipot, Christophe; Schweighofer, Karl

    2000-01-01

    In the absence of extinct or extant record of protocells (the earliest ancestors of contemporary cells). the most direct way to test our understanding of the origin of cellular life is to construct laboratory models of protocells. Such efforts are currently underway in the NASA Astrobiology Program. They are accompanied by computational studies aimed at explaining self-organization of simple molecules into ordered structures and developing designs for molecules that perform proto-cellular functions. Many of these functions, such as import of nutrients, capture and storage of energy. and response to changes in the environment are carried out by proteins bound to membrane< We will discuss a series of large-scale, molecular-level computer simulations which demonstrate (a) how small proteins (peptides) organize themselves into ordered structures at water-membrane interfaces and insert into membranes, (b) how these peptides aggregate to form membrane-spanning structures (eg. channels), and (c) by what mechanisms such aggregates perform essential proto-cellular functions, such as proton transport of protons across cell walls, a key step in cellular bioenergetics. The simulations were performed using the molecular dynamics method, in which Newton's equations of motion for each item in the system are solved iteratively. The problems of interest required simulations on multi-nanosecond time scales, which corresponded to 10(exp 6)-10(exp 8) time steps.

  8. Nanotopographical modification: a regulator of cellular function through focal adhesions

    PubMed Central

    Biggs, Manus Jonathan Paul; Richards, R. Geoff; Dalby, Matthew J.

    2010-01-01

    As materials technology and the field of biomedical engineering advances, the role of cellular mechanisms, in particular adhesive interactions with implantable devices, becomes more relevant in both research and clinical practice. A key tenet of medical device design has evolved from the exquisite ability of biological systems to respond to topographical features or chemical stimuli, a process that has led to the development of next-generation biomaterials for a wide variety of clinical disorders. In vitro studies have identified nanoscale features as potent modulators of cellular behavior through the onset of focal adhesion formation. The focus of this review is on the recent developments concerning the role of nanoscale structures on integrin-mediated adhesion and cellular function with an emphasis on the generation of medical constructs with regenerative applications. PMID:20138244

  9. Kinetic Adaptations of Myosins for Their Diverse Cellular Functions.

    PubMed

    Heissler, Sarah M; Sellers, James R

    2016-08-01

    Members of the myosin superfamily are involved in all aspects of eukaryotic life. Their function ranges from the transport of organelles and cargos to the generation of membrane tension, and the contraction of muscle. The diversity of physiological functions is remarkable, given that all enzymatically active myosins follow a conserved mechanoenzymatic cycle in which the hydrolysis of ATP to ADP and inorganic phosphate is coupled to either actin-based transport or tethering of actin to defined cellular compartments. Kinetic capacities and limitations of a myosin are determined by the extent to which actin can accelerate the hydrolysis of ATP and the release of the hydrolysis products and are indispensably linked to its physiological tasks. This review focuses on kinetic competencies that - together with structural adaptations - result in myosins with unique mechanoenzymatic properties targeted to their diverse cellular functions. PMID:26929436

  10. Vesicular stomatitis virus P function depends on cellular growth cycle.

    PubMed

    Stanners, C P; Kennedy, S; Poliquin, L

    1987-09-01

    The P function of vesicular stomatitis virus (VSV) is defined as the viral function which results in a reduced rate of total protein synthesis (viral plus cellular) arising from a nonspecific reduction in the efficiency of the translational machinery in infected cells. The existence of P function has been challenged by Lodish and Porter who were unable to detect it in L-strain mouse cells infected with wild-type VSV (HR) or, as expected, with the P- mutant, T1026-R1. Although other groups have subsequently confirmed the existence of P function and the difference between HR and T1026-R1, we have sought an explanation for the difference between Lodish and Porter's results and those of other laboratories. We show that the VSV P function depends on the phase of the growth cycle of infected L-cell cultures. In very early exponential phase, as used by Lodish and Porter, HR has very little demonstrable P function; as the growth cycle proceeds toward stationary phase, P function becomes more and more manifest. Under the same conditions, T1026-R1 shows no P function throughout the growth cycle. Furthermore we show that the VSV M protein mutant tsG31 has a P++ phenotype reducing total protein synthesis below that seen with wild-type HR. P function can be observed in cells infected with tsG31, even early in the exponential phase of the cellular growth cycle. PMID:2820132

  11. Mitochondrial DNA Alterations and Reduced Mitochondrial Function in Aging

    PubMed Central

    Hebert, Sadie L.; Lanza, Ian R.; Nair, K. Sreekumaran

    2010-01-01

    Oxidative damage to mitochondrial DNA increases with aging. This damage has the potential to affect mitochondrial DNA replication and transcription which could alter the abundance or functionality of mitochondrial proteins. This review describes mitochondrial DNA alterations and changes in mitochondrial function that occur with aging. Age-related alterations in mitochondrial DNA as a possible contributor to the reduction in mitochondrial function are discussed. PMID:20307565

  12. Cellular interactions during tracheary elements formation and function.

    PubMed

    Ménard, Delphine; Pesquet, Edouard

    2015-02-01

    The survival of higher plant species on land depends on the development and function of an efficient vascular system distributing water and minerals absorbed by roots to all aerial organs. This conduction and distribution of plant sap relies on specialized cells named tracheary elements (TEs). In contrast to many other cell types in plants, TEs are functionalized by cell death that hollows the cell protoplast to make way for the sap. To maintain a stable conducting function during plant development, recovery from vascular damages as well as to adapt to environmental changes, TEs are completely dependent on direct cellular interactions with neighboring xylem parenchyma cells (XPs). PMID:25545993

  13. Methods for Determining the Cellular Functions of Vimentin Intermediate Filaments.

    PubMed

    Ridge, Karen M; Shumaker, Dale; Robert, Amélie; Hookway, Caroline; Gelfand, Vladimir I; Janmey, Paul A; Lowery, Jason; Guo, Ming; Weitz, David A; Kuczmarski, Edward; Goldman, Robert D

    2016-01-01

    The type III intermediate filament protein vimentin was once thought to function mainly as a static structural protein in the cytoskeleton of cells of mesenchymal origin. Now, however, vimentin is known to form a dynamic, flexible network that plays an important role in a number of signaling pathways. Here, we describe various methods that have been developed to investigate the cellular functions of the vimentin protein and intermediate filament network, including chemical disruption, photoactivation and photoconversion, biolayer interferometry, soluble bead binding assay, three-dimensional substrate experiments, collagen gel contraction, optical-tweezer active microrheology, and force spectrum microscopy. Using these techniques, the contributions of vimentin to essential cellular processes can be probed in ever further detail. PMID:26795478

  14. Methods for Determining the Cellular Functions of Vimentin Intermediate Filaments

    PubMed Central

    Ridge, Karen M.; Shumaker, Dale; Robert, Amélie; Hookway, Caroline; Gelfand, Vladimir I.; Janmey, Paul A.; Lowery, Jason; Guo, Ming; Weitz, David A.; Kuczmarski, Edward; Goldman, Robert D.

    2016-01-01

    The type III intermediate filament protein vimentin was once thought to function mainly as a static structural protein in the cytoskeleton of cells of mesenchymal origin. Now, however, vimentin is known to form a dynamic, flexible network that plays an important role in a number of signaling pathways. Here, we describe various methods that have been developed to investigate the cellular functions of the vimentin protein and intermediate filament network, including chemical disruption, photoactivation and photoconversion, biolayer interferometry, soluble bead binding assay, three-dimensional substrate experiments, collagen gel contraction, optical-tweezer active microrheology, and force spectrum microscopy. Using these techniques, the contributions of vimentin to essential cellular processes can be probed in ever further detail. PMID:26795478

  15. Biology under construction: in vitro reconstitution of cellular function

    PubMed Central

    Liu, Allen P.; Fletcher, Daniel A.

    2010-01-01

    We are much better at taking cells apart than putting them together. Reconstitution of biological processes from component molecules has been a powerful but difficult approach to studying functional organization in biology. Recently, the convergence of biochemical and cell biological advances with new experimental and computational tools is providing the opportunity to reconstitute increasingly complex processes. We predict that this bottom-up strategy will uncover basic processes that guide cellular assembly, advancing both basic and applied sciences. PMID:19672276

  16. Intravital FRET: Probing Cellular and Tissue Function in Vivo.

    PubMed

    Radbruch, Helena; Bremer, Daniel; Mothes, Ronja; Günther, Robert; Rinnenthal, Jan Leo; Pohlan, Julian; Ulbricht, Carolin; Hauser, Anja E; Niesner, Raluca

    2015-01-01

    The development of intravital Förster Resonance Energy Transfer (FRET) is required to probe cellular and tissue function in the natural context: the living organism. Only in this way can biomedicine truly comprehend pathogenesis and develop effective therapeutic strategies. Here we demonstrate and discuss the advantages and pitfalls of two strategies to quantify FRET in vivo-ratiometrically and time-resolved by fluorescence lifetime imaging-and show their concrete application in the context of neuroinflammation in adult mice. PMID:26006244

  17. The phosphate makes a difference: cellular functions of NADP.

    PubMed

    Agledal, Line; Niere, Marc; Ziegler, Mathias

    2010-01-01

    Recent research has unraveled a number of unexpected functions of the pyridine nucleotides. In this review, we will highlight the variety of known physiological roles of NADP. In its reduced form (NADPH), this molecule represents a universal electron donor, not only to drive biosynthetic pathways. Perhaps even more importantly, NADPH is the unique provider of reducing equivalents to maintain or regenerate the cellular detoxifying and antioxidative defense systems. The roles of NADPH in redox sensing and as substrate for NADPH oxidases to generate reactive oxygen species further extend its scope of functions. NADP(+), on the other hand, has acquired signaling functions. Its conversion to second messengers in calcium signaling may have critical impact on important cellular processes. The generation of NADP by NAD kinases is a key determinant of the cellular NADP concentration. The regulation of these enzymes may, therefore, be critical to feed the diversity of NADP-dependent processes adequately. The increasing recognition of the multiple roles of NADP has thus led to exciting new insights in this expanding field. PMID:20196923

  18. Analysis of Functional Pathways Altered after Mild Traumatic Brain Injury

    PubMed Central

    Redell, John B.; Moore, Anthony N.; Grill, Raymond J.; Johnson, Daniel; Zhao, Jing; Liu, Yin

    2013-01-01

    Abstract Concussive injury (or mild traumatic brain injury; mTBI) can exhibit features of focal or diffuse injury patterns. We compared and contrasted the cellular and molecular responses after mild controlled cortical impact (mCCI; a focal injury) or fluid percussion injury (FPI; a diffuse injury) in rats. The rationale for this comparative analysis was to investigate the brain's response to mild diffuse versus mild focal injury to identify common molecular changes triggered by these injury modalities and to determine the functional pathways altered after injury that may provide novel targets for therapeutic intervention. Microarrays containing probes against 21,792 unique messenger RNAs (mRNAs) were used to investigate the changes in cortical mRNA expression levels at 3 and 24 h postinjury. Of the 354 mRNAs with significantly altered expression levels after mCCI, over 89% (316 mRNAs) were also contained within the mild FPI (mFPI) data set. However, mFPI initiated a more widespread molecular response, with over 2300 mRNAs differentially expressed. Bioinformatic analysis of annotated Gene Ontology molecular function and biological pathway terms showed a significant overrepresentation of genes belonging to inflammation, stress, and signaling categories in both data sets. We therefore examined changes in the protein levels of a panel of 23 cytokines and chemokines in cortical extracts using a Luminex-based bead immunoassay and detected significant increases in macrophage inflammatory protein (MIP)-1α (CCL3), GRO-KC (CXCL1), interleukin (IL)-1α, IL-1β, and IL-6. Immunohistochemical localization of MIP-1α and IL-1β showed marked increases at 3 h postinjury in the cortical vasculature and microglia, respectively, that were largely resolved by 24 h postinjury. Our findings demonstrate that both focal and diffuse mTBI trigger many shared pathobiological processes (e.g., inflammatory responses) that could be targeted for mechanism-based therapeutic interventions

  19. Deconstructing the third dimension – how 3D culture microenvironments alter cellular cues

    PubMed Central

    Baker, Brendon M.; Chen, Christopher S.

    2012-01-01

    Summary Much of our understanding of the biological mechanisms that underlie cellular functions, such as migration, differentiation and force-sensing has been garnered from studying cells cultured on two-dimensional (2D) glass or plastic surfaces. However, more recently the cell biology field has come to appreciate the dissimilarity between these flat surfaces and the topographically complex, three-dimensional (3D) extracellular environments in which cells routinely operate in vivo. This has spurred substantial efforts towards the development of in vitro 3D biomimetic environments and has encouraged much cross-disciplinary work among biologists, material scientists and tissue engineers. As we move towards more-physiological culture systems for studying fundamental cellular processes, it is crucial to define exactly which factors are operative in 3D microenvironments. Thus, the focus of this Commentary will be on identifying and describing the fundamental features of 3D cell culture systems that influence cell structure, adhesion, mechanotransduction and signaling in response to soluble factors, which – in turn – regulate overall cellular function in ways that depart dramatically from traditional 2D culture formats. Additionally, we will describe experimental scenarios in which 3D culture is particularly relevant, highlight recent advances in materials engineering for studying cell biology, and discuss examples where studying cells in a 3D context provided insights that would not have been observed in traditional 2D systems. PMID:22797912

  20. Membrane-Based Functions in the Origin of Cellular Life

    NASA Technical Reports Server (NTRS)

    Chipot, Christophe; New, Michael H.; Schweighofer, Karl; Pohorille, Andrew; Wilson, Michael A.

    1999-01-01

    Our objective is to help explain how the earliest ancestors of contemporary cells (protocells) performed their essential functions employing only the molecules available in the protobiological milieu. Our hypothesis is that vesicles, built of amphiphilic, membrane-forming materials, emerged early in protobiological evolution and served as precursors to protocells. We further assume that the cellular functions associated with contemporary membranes, such as capturing and, transducing of energy, signaling, or sequestering organic molecules and ions, evolved in these membrane environments. An alternative hypothesis is that these functions evolved in different environments and were incorporated into membrane-bound structures at some later stage of evolution. We focus on the application of the fundamental principles of physics and chemistry to determine how they apply to the formation of a primitive, functional cell. Rather than attempting to develop specific models for cellular functions and to identify the origin of the molecules which perform these functions, our goal is to define the structural and energetic conditions that any successful model must fulfill, therefore providing physico-chemical boundaries for these models. We do this by carrying out large-scale, molecular level computer simulations on systems of interest.

  1. Different Candida parapsilosis clinical isolates and lipase deficient strain trigger an altered cellular immune response

    PubMed Central

    Tóth, Renáta; Alonso, Maria F.; Bain, Judith M.; Vágvölgyi, Csaba; Erwig, Lars-Peter; Gácser, Attila

    2015-01-01

    Numerous human diseases can be associated with fungal infections either as potential causative agents or as a result of changed immune status due to a primary disease. Fungal infections caused by Candida species can vary from mild to severe dependent upon the site of infection, length of exposure, and past medical history. Patients with impaired immune status are at increased risk for chronic fungal infections. Recent epidemiologic studies have revealed the increasing incidence of candidiasis caused by non-albicans species such as Candida parapsilosis. Due to its increasing relevance we chose two distinct C. parapsilosis strains, to describe the cellular innate immune response toward this species. In the first section of our study we compared the interaction of CLIB 214 and GA1 cells with murine and human macrophages. Both strains are commonly used to investigate C. parapsilosis virulence properties. CLIB 214 is a rapidly pseudohyphae-forming strain and GA1 is an isolate that mainly exists in a yeast form. Our results showed, that the phagocyte response was similar in terms of overall uptake, however differences were observed in macrophage migration and engulfment of fungal cells. As C. parapsilosis releases extracellular lipases in order to promote host invasion we further investigated the role of these secreted components during the distinct stages of the phagocytic process. Using a secreted lipase deficient mutant strain and the parental strain GA1 individually and simultaneously, we confirmed that fungal secreted lipases influence the fungi's virulence by detecting altered innate cellular responses. In this study we report that two isolates of a single species can trigger markedly distinct host responses and that lipase secretion plays a role on the cellular level of host–pathogen interactions. PMID:26528256

  2. Using RNA as Molecular Code for Programming Cellular Function.

    PubMed

    Kushwaha, Manish; Rostain, William; Prakash, Satya; Duncan, John N; Jaramillo, Alfonso

    2016-08-19

    RNA is involved in a wide-range of important molecular processes in the cell, serving diverse functions: regulatory, enzymatic, and structural. Together with its ease and predictability of design, these properties can lead RNA to become a useful handle for biological engineers with which to control the cellular machinery. By modifying the many RNA links in cellular processes, it is possible to reprogram cells toward specific design goals. We propose that RNA can be viewed as a molecular programming language that, together with protein-based execution platforms, can be used to rewrite wide ranging aspects of cellular function. In this review, we catalogue developments in the use of RNA parts, methods, and associated computational models that have contributed to the programmability of biology. We discuss how RNA part repertoires have been combined to build complex genetic circuits, and review recent applications of RNA-based parts and circuitry. We explore the future potential of RNA engineering and posit that RNA programmability is an important resource for firmly establishing an era of rationally designed synthetic biology. PMID:26999422

  3. Modelling chronotaxicity of cellular energy metabolism to facilitate the identification of altered metabolic states.

    PubMed

    Lancaster, Gemma; Suprunenko, Yevhen F; Jenkins, Kirsten; Stefanovska, Aneta

    2016-01-01

    Altered cellular energy metabolism is a hallmark of many diseases, one notable example being cancer. Here, we focus on the identification of the transition from healthy to abnormal metabolic states. To do this, we study the dynamics of energy production in a cell. Due to the thermodynamic openness of a living cell, the inability to instantaneously match fluctuating supply and demand in energy metabolism results in nonautonomous time-varying oscillatory dynamics. However, such oscillatory dynamics is often neglected and treated as stochastic. Based on experimental evidence of metabolic oscillations, we show that changes in metabolic state can be described robustly by alterations in the chronotaxicity of the corresponding metabolic oscillations, i.e. the ability of an oscillator to resist external perturbations. We also present a method for the identification of chronotaxicity, applicable to general oscillatory signals and, importantly, apply this to real experimental data. Evidence of chronotaxicity was found in glycolytic oscillations in real yeast cells, verifying that chronotaxicity could be used to study transitions between metabolic states. PMID:27483987

  4. Modelling chronotaxicity of cellular energy metabolism to facilitate the identification of altered metabolic states

    PubMed Central

    Lancaster, Gemma; Suprunenko, Yevhen F.; Jenkins, Kirsten; Stefanovska, Aneta

    2016-01-01

    Altered cellular energy metabolism is a hallmark of many diseases, one notable example being cancer. Here, we focus on the identification of the transition from healthy to abnormal metabolic states. To do this, we study the dynamics of energy production in a cell. Due to the thermodynamic openness of a living cell, the inability to instantaneously match fluctuating supply and demand in energy metabolism results in nonautonomous time-varying oscillatory dynamics. However, such oscillatory dynamics is often neglected and treated as stochastic. Based on experimental evidence of metabolic oscillations, we show that changes in metabolic state can be described robustly by alterations in the chronotaxicity of the corresponding metabolic oscillations, i.e. the ability of an oscillator to resist external perturbations. We also present a method for the identification of chronotaxicity, applicable to general oscillatory signals and, importantly, apply this to real experimental data. Evidence of chronotaxicity was found in glycolytic oscillations in real yeast cells, verifying that chronotaxicity could be used to study transitions between metabolic states. PMID:27483987

  5. Violent Video Games Alter Brain Function in Young Men

    MedlinePlus

    ... and Updates News from the RSNA Annual Meeting Violent Video Games Alter Brain Function in Young Men ... Using functional MRI, researchers have found that playing violent video games for one week causes changes in ...

  6. Protein engineering strategies with potential applications for altering clinically relevant cellular pathways at the protein level.

    PubMed

    Regan, Lynne; Hinrichsen, Michael R; Oi, Curran

    2016-05-01

    All diseases can be fundamentally viewed as the result of malfunctioning cellular pathways. Protein engineering offers the potential to develop new tools that will allow these dysfunctional pathways to be better understood, in addition to potentially providing new routes to restore proper function. Here we discuss different approaches that can be used to change the intracellular activity of a protein by intervening at the protein level: targeted protein sequestration, protein recruitment, protein degradation, and selective inhibition of binding interfaces. The potential of each of these tools to be developed into effective therapeutic treatments will also be discussed, along with any major barriers that currently block their translation into the clinic. PMID:27031866

  7. Role of XPD in cellular functions: To TFIIH and beyond.

    PubMed

    Houten, Bennett Van; Kuper, Jochen; Kisker, Caroline

    2016-08-01

    XPD, as part of the TFIIH complex, has classically been linked to the damage verification step of nucleotide excision repair (NER). However, recent data indicate that XPD, due to its iron-sulfur center interacts with the iron sulfur cluster assembly proteins, and may interact with other proteins in the cell to mediate a diverse set of biological functions including cell cycle regulation, mitosis, and mitochondrial function. In this perspective, after first reviewing the function and some of the key disease causing variants that affect XPD's interaction with TFIIH and the CDK-activating kinase complex (CAK), we investigate these intriguing cellular roles of XPD and highlight important unanswered questions that provide a fertile ground for further scientific exploration. PMID:27262611

  8. Computer Modeling of the Earliest Cellular Structures and Functions

    NASA Astrophysics Data System (ADS)

    Pohorille, Andrew

    2000-03-01

    In the absence of extinct or extant record of protocells (the earliest ancestors of contemporary cells), the most direct way to test ourunderstanding of the origin of cellular life is to construct laboratory models of protocells. Such efforts are currently underway in the NASA Astrobiology Program. They are accompanied by computational studies aimed at explaining self-organization of simple molecules into ordered structures and developing designs for molecules that perform protocellular functions. Many of these functions, such as import of nutrients, capture and storage of energy, and response to changes in the environment are carried out by proteins bound to membranes. We will discuss a series of large-scale, molecular-level computer simulations which demonstrate (a) how small proteins (peptides)organize themselves into ordered structures at water-membrane interfaces and insert into membranes, (b) how these peptides aggregate to form membrane-spanning structures (e.g. channels), and (c) by what mechanisms such aggregates perform essential protocellular functions, such as proton transport of protons across cell walls, a key step in cellular bioenergetics. The simulations were performed using the molecular dynamics method, in which Newton's equations of motion for each atom in the system are solved iteratively. The problems of interest required simulations on multi-nanosecond time scales, which corresponded to 10^6-10^8 time steps.

  9. PEG functionalized luminescent lipid particles for cellular imaging

    NASA Astrophysics Data System (ADS)

    Rana, Suman; Barick, K. C.; Shetake, Neena G.; Verma, Gunjan; Aswal, V. K.; Panicker, Lata; Pandey, B. N.; Hassan, P. A.

    2016-08-01

    We report here the synthesis, characterization and cellular uptake of luminescent micelle-like particles with phospholipid core and non-ionic PEG based surfactant polysorbate 80 shell. The adsorption of polysorbate 80 at the interface of lipid containing microemulsion droplets and its solidification upon removal of solvent leads to anchoring of PEG chain to the lipid particles. Hydrophobic partitioning of luminescent molecules, sodium 3-hydroxynaphthalene-2-carboxylic acid to the phospholipid core offers additional functionality to these particles. Thus, the cooperative assembly of lipid, non-ionic amphiphile and organic luminescent probe leads to the formation of multifunctional biocompatible particles which are useful for simultaneous imaging and therapy.

  10. Assemblages: Functional units formed by cellular phase separation

    PubMed Central

    Wright, Peter E.

    2014-01-01

    The partitioning of intracellular space beyond membrane-bound organelles can be achieved with collections of proteins that are multivalent or contain low-complexity, intrinsically disordered regions. These proteins can undergo a physical phase change to form functional granules or other entities within the cytoplasm or nucleoplasm that collectively we term “assemblage.” Intrinsically disordered proteins (IDPs) play an important role in forming a subset of cellular assemblages by promoting phase separation. Recent work points to an involvement of assemblages in disease states, indicating that intrinsic disorder and phase transitions should be considered in the development of therapeutics. PMID:25179628

  11. 3D scaffold alters cellular response to graphene in a polymer composite for orthopedic applications.

    PubMed

    Kumar, Sachin; Azam, Dilkash; Raj, Shammy; Kolanthai, Elayaraja; Vasu, K S; Sood, A K; Chatterjee, Kaushik

    2016-05-01

    Graphene-based polymer nanocomposites are being studied for biomedical applications. Polymer nanocomposites can be processed differently to generate planar two-dimensional (2D) substrates and porous three-dimensional (3D) scaffolds. The objective of this work was to investigate potential differences in biological response to graphene in polymer composites in the form of 2D substrates and 3D scaffolds. Polycaprolactone (PCL) nanocomposites were prepared by incorporating 1% of graphene oxide (GO) and reduced graphene oxide (RGO). GO increased modulus and strength of PCL by 44 and 22% respectively, whereas RGO increased modulus and strength by 22 and 16%, respectively. RGO increased the water contact angle of PCL from 81° to 87° whereas GO decreased it to 77°. In 2D, osteoblast proliferated 15% more on GO composites than on PCL whereas RGO composite showed 17% decrease in cell proliferation, which may be attributed to differences in water wettability. In 3D, initial cell proliferation was markedly retarded in both GO (36% lower) and RGO (55% lower) composites owing to increased roughness due to the presence of the protruding nanoparticles. Cells organized into aggregates in 3D in contrast to spread and randomly distributed cells on 2D discs due to the macro-porous architecture of the scaffolds. Increased cell-cell contact and altered cellular morphology led to significantly higher mineralization in 3D. This study demonstrates that the cellular response to nanoparticles in composites can change markedly by varying the processing route and has implications for designing orthopedic implants such as resorbable fracture fixation devices and tissue scaffolds using such nanocomposites. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 732-749, 2016. PMID:26482196

  12. Alterations of Cellular Immune Reactions in Crew Members Overwintering in the Antarctic Research Station Concordia

    NASA Technical Reports Server (NTRS)

    Crucian, Brian; Feuerecker, Matthias; Moreels, Marjan; Crucian, Brian; Kaufmann, Ines; Salam, Alex Paddy; Rybka, Alex; Ulrike, Thieme; Quintens, Roel; Sams, Clarence F.; Schelling, Gustav; Thiel, Manfred; Baatout, Sarah; Chouker, Alexander

    2012-01-01

    Background: Concordia Station is located inside Antarctica about 1000km from the coast at an altitude of 3200m (Dome C). Hence, individuals living in this harsh environment are exposed to two major conditions: 1.) hypobaric hypoxia and 2.) confinement and extreme isolation. Both hypoxia and confinement can affect human immunity and health, and are likely to be present during exploration class space missions. This study focused on immune alterations measured by a new global immunity test assay, similar to the phased out delayed type hypersensitivity (DTH) skin test. Methods: After informed written consent 14 healthy male subjects were included to the CHOICE-study (Consequences-of-longterm-Confinement-and-Hypobaric-HypOxia-on-Immunity-in-the Antarctic-Concordia-Environment). Data collection occurred during two winter-over periods lasting each one year. During the first campaign 6 healthy male were enrolled followed by a second campaign with 8 healthy males. Blood was drawn monthly and incubated for 48h with various bacterial, viral and fungal antigens followed by an analysis of plasma cytokine levels (TNF-alpha, IL2, IFN-gamma, IL10). As a control, blood was incubated without stimulation ("resting condition"). Goals: The scope of this study was to assess the consequences of hypoxia and confinement on cellular immunity as assessed by a new in vitro DTH-like test. Results: Initial results indicate that under resting conditions the in vitro DTH-like test showed low cytokine levels which remained almost unchanged during the entire observation period. However, cytokine responses to viral, bacterial and fungal antigens were remarkably reduced at the first month after arrival at Concordia when compared to levels measured in Europe prior to departure for Antarctica. With incrementing months of confinement this depressed DTH-like response tended to reverse, and in fact to show an "overshooting" immune reaction after stimulation. Conclusion: The reduced in vitro DTH-like test

  13. Altered functional connectivity in persistent developmental stuttering

    PubMed Central

    Yang, Yang; Jia, Fanlu; Siok, Wai Ting; Tan, Li Hai

    2016-01-01

    Persistent developmental stuttering (PDS) is a speech disorder that impairs communication skills. Despite extensive research, the core causes of PDS are elusive. Converging evidence from task-induced neuroimaging methods has demonstrated the contributions of the basal ganglia and the cerebellum to PDS, but such task-state neuroimaging findings are often confounded by behavioral performance differences between subjects who stutter and normal controls. Here, using resting-state functional magnetic resonance imaging, we investigated functional connectivity within cerebellar-cortical and basal ganglia-thalamocortical networks in 16 adults who stutter and 18 age-matched fluent speakers. Seed-to-voxel analysis demonstrated that, compared to controls, adults who stutter showed alternations in functional connectivity of cerebellum to motor cortex as well as connectivity among different locals within cerebellum. Additionally, we found that functional connectivity within cerebellar circuits was significantly correlated with severity of stuttering. The alternations of functional connectivity within basal ganglia-thalamocortical networks were identified as the reduced connectivity of the putamen to the superior temporal gyrus and inferior parietal lobules in adults who stutter. The abnormalities of resting state functional connectivity are assumed to affect language planning and motor execution critical for speaking fluently. Our findings may yield neurobiological cues to the biomarkers of PDS. PMID:26743821

  14. Altered functional connectivity in persistent developmental stuttering.

    PubMed

    Yang, Yang; Jia, Fanlu; Siok, Wai Ting; Tan, Li Hai

    2016-01-01

    Persistent developmental stuttering (PDS) is a speech disorder that impairs communication skills. Despite extensive research, the core causes of PDS are elusive. Converging evidence from task-induced neuroimaging methods has demonstrated the contributions of the basal ganglia and the cerebellum to PDS, but such task-state neuroimaging findings are often confounded by behavioral performance differences between subjects who stutter and normal controls. Here, using resting-state functional magnetic resonance imaging, we investigated functional connectivity within cerebellar-cortical and basal ganglia-thalamocortical networks in 16 adults who stutter and 18 age-matched fluent speakers. Seed-to-voxel analysis demonstrated that, compared to controls, adults who stutter showed alternations in functional connectivity of cerebellum to motor cortex as well as connectivity among different locals within cerebellum. Additionally, we found that functional connectivity within cerebellar circuits was significantly correlated with severity of stuttering. The alternations of functional connectivity within basal ganglia-thalamocortical networks were identified as the reduced connectivity of the putamen to the superior temporal gyrus and inferior parietal lobules in adults who stutter. The abnormalities of resting state functional connectivity are assumed to affect language planning and motor execution critical for speaking fluently. Our findings may yield neurobiological cues to the biomarkers of PDS. PMID:26743821

  15. Exome capture sequencing of adenoma reveals genetic alterations in multiple cellular pathways at the early stage of colorectal tumorigenesis.

    PubMed

    Zhou, Donger; Yang, Liu; Zheng, Liangtao; Ge, Weiting; Li, Dan; Zhang, Yong; Hu, Xueda; Gao, Zhibo; Xu, Jinghong; Huang, Yanqin; Hu, Hanguang; Zhang, Hang; Zhang, Hao; Liu, Mingming; Yang, Huanming; Zheng, Lei; Zheng, Shu

    2013-01-01

    Most of colorectal adenocarcinomas are believed to arise from adenomas, which are premalignant lesions. Sequencing the whole exome of the adenoma will help identifying molecular biomarkers that can predict the occurrence of adenocarcinoma more precisely and help understanding the molecular pathways underlying the initial stage of colorectal tumorigenesis. We performed the exome capture sequencing of the normal mucosa, adenoma and adenocarcinoma tissues from the same patient and sequenced the identified mutations in additional 73 adenomas and 288 adenocarcinomas. Somatic single nucleotide variations (SNVs) were identified in both the adenoma and adenocarcinoma by comparing with the normal control from the same patient. We identified 12 nonsynonymous somatic SNVs in the adenoma and 42 nonsynonymous somatic SNVs in the adenocarcinoma. Most of these mutations including OR6X1, SLC15A3, KRTHB4, RBFOX1, LAMA3, CDH20, BIRC6, NMBR, GLCCI1, EFR3A, and FTHL17 were newly reported in colorectal adenomas. Functional annotation of these mutated genes showed that multiple cellular pathways including Wnt, cell adhesion and ubiquitin mediated proteolysis pathways were altered genetically in the adenoma and that the genetic alterations in the same pathways persist in the adenocarcinoma. CDH20 and LAMA3 were mutated in the adenoma while NRXN3 and COL4A6 were mutated in the adenocarcinoma from the same patient, suggesting for the first time that genetic alterations in the cell adhesion pathway occur as early as in the adenoma. Thus, the comparison of genomic mutations between adenoma and adenocarcinoma provides us a new insight into the molecular events governing the early step of colorectal tumorigenesis. PMID:23301059

  16. Neurophysiology of HCN channels: from cellular functions to multiple regulations.

    PubMed

    He, Chao; Chen, Fang; Li, Bo; Hu, Zhian

    2014-01-01

    Hyperpolarization-activated cyclic nucleotide-gated (HCN) cation channels are encoded by HCN1-4 gene family and have four subtypes. These channels are activated upon hyperpolarization of membrane potential and conduct an inward, excitatory current Ih in the nervous system. Ih acts as pacemaker current to initiate rhythmic firing, dampen dendritic excitability and regulate presynaptic neurotransmitter release. This review summarizes recent insights into the cellular functions of Ih and associated behavior such as learning and memory, sleep and arousal. HCN channels are excellent targets of various cellular signals to finely regulate neuronal responses to external stimuli. Numerous mechanisms, including transcriptional control, trafficking, as well as channel assembly and modification, underlie HCN channel regulation. In the next section, we discuss how the intracellular signals, especially recent findings concerning protein kinases and interacting proteins such as cGKII, Ca(2+)/CaMKII and TRIP8b, regulate function and expression of HCN channels, and subsequently provide an overview of the effects of neurotransmitters on HCN channels and their corresponding intracellular mechanisms. We also discuss the dysregulation of HCN channels in pathological conditions. Finally, insight into future directions in this exciting area of ion channel research is provided. PMID:24184323

  17. Altered behavioral aspects of aged mice lacking the cellular prion protein.

    PubMed

    Massimino, Maria Lina; Redaelli, Marco; Bertoli, Alessandro; Sorgato, Maria Catia; Mucignat-Caretta, Carla

    2013-07-01

    The biological function of the prion protein, which is intimately involved in the onset of prion diseases, remains unclear. To understand whether the prion protein could play a role in animal behavior, a battery of tests was applied to young and aged mice that express, or not, the prion protein. In contrast to the similar results obtained in all young animals, we found that aged mice lacking the prion protein reacted to new and stressful environments differently than their wild-type counterparts. This may suggest that, upon aging, the absence of the prion protein results in altered neural processing at the basis of adaptation to new situations. PMID:23770331

  18. USP1 deubiquitinase: cellular functions, regulatory mechanisms and emerging potential as target in cancer therapy

    PubMed Central

    2013-01-01

    Reversible protein ubiquitination is emerging as a key process for maintaining cell homeostasis, and the enzymes that participate in this process, in particular E3 ubiquitin ligases and deubiquitinases (DUBs), are increasingly being regarded as candidates for drug discovery. Human DUBs are a group of approximately 100 proteins, whose cellular functions and regulatory mechanisms remain, with some exceptions, poorly characterized. One of the best-characterized human DUBs is ubiquitin-specific protease 1 (USP1), which plays an important role in the cellular response to DNA damage. USP1 levels, localization and activity are modulated through several mechanisms, including protein-protein interactions, autocleavage/degradation and phosphorylation, ensuring that USP1 function is carried out in a properly regulated spatio-temporal manner. Importantly, USP1 expression is deregulated in certain types of human cancer, suggesting that USP1 could represent a valid target in cancer therapy. This view has gained recent support with the finding that USP1 inhibition may contribute to revert cisplatin resistance in an in vitro model of non-small cell lung cancer (NSCLC). Here, we describe the current knowledge on the cellular functions and regulatory mechanisms of USP1. We also summarize USP1 alterations found in cancer, combining data from the literature and public databases with our own data. Finally, we discuss the emerging potential of USP1 as a target, integrating published data with our novel findings on the effects of the USP1 inhibitor pimozide in combination with cisplatin in NSCLC cells. PMID:23937906

  19. Modulating Cellular Recombination Potential through Alterations in RecA Structure and Regulation

    PubMed Central

    Bakhlanova, Irina V.; Dudkina, Alexandra V.; Baitin, Dima M.; Knight, Kendall L.; Cox, Michael M.; Lanzov, Vladislav A.

    2010-01-01

    The wild type E. coli RecA protein is a recombinase platform with unrealized recombination potential. We have explored the factors affecting recombination during conjugation with a quantitative assay. Regulatory proteins that affect RecA function have the capacity to increase or decrease recombination frequencies by factors up to 6 fold. Autoinhibition by the RecA C-terminus can affect recombination frequency by factors up to 4 fold. The greatest changes in recombination frequency measured here are brought about by point mutations in the recA gene. RecA variants can increase recombination frequencies by more than 50 fold. The RecA protein thus possesses an inherently broad functional range. The RecA protein of Escherichia coli (EcRecA) is not optimized for recombination function. Instead, much of the recombination potential of EcRecA is structurally suppressed, probably reflecting cellular requirements. One point mutation in EcRecA with a particularly dramatic effect on recombination frequency, D112R, exhibits an enhanced capacity to load onto SSB-coated ssDNA, overcome the effects of regulatory proteins such as PsiB and RecX, and to pair homologous DNAs. Comparisons of key RecA protein mutants reveal two components to RecA recombination function – filament formation and the inherent DNA pairing activity of the formed filaments. PMID:21143322

  20. Characterizing neuromorphologic alterations with additive shape functionals

    NASA Astrophysics Data System (ADS)

    Barbosa, M. S.; Costa, L. Da F.; Bernardes, E. S.; Ramakers, G.; van Pelt, J.

    2004-01-01

    The complexity of a neuronal cell shape is known to be related to its function. Specifically, among other indicators, a decreased complexity in the dendritic trees of cortical pyramidal neurons has been associated with mental retardation. In this paper we develop a procedure to address the characterization of morphological changes induced in cultured neurons by over-expressing a gene involved in mental retardation. Measures associated with the multiscale connectivity, an additive image functional, are found to give a reasonable separation criterion between two categories of cells. One category consists of a control group and two transfected groups of neurons, and the other, a class of cat ganglionary cells. The reported framework also identified a trend towards lower complexity in one of the transfected groups. Such results establish the suggested measures as an effective descriptors of cell shape.

  1. Protozoa as model systems for the study of cellular responses to altered gravity conditions.

    PubMed

    Hemmersbach-Krause, R; Briegleb, W; Häder D-P; Vogel, K; Klein, S; Mulisch, M

    1994-01-01

    The orientation behavior of Paramecium changed in a similar way after transition to conditions of free-fall in a sounding rocket and after transition to conditions of simulated weightlessness on a fast rotating clinostat. After a period of residual orientation, Paramecium cells distributed themselves randomly 80 s (120 s) after onset of free-fall (simulated weightlessness). Swimming velocity increased significantly; however, the increase was transient and subsided after 3 min in the rocket experiments, while the velocity remained enhanced even during 2 h of rotation on a fast clinostat. Trichocysts were present and without morphological changes in Paramecium cells which had been exposed to a rocket flight, as well as to fast or slow rotation on a clinostat. Regeneration of the oral apparatus of Stentor and morphogenesis of Eufolliculina proceeded normally on the clinostat. The results demonstrate that the clinostat is a useful tool to simulate the conditions of weightlessness on earth and to detect gravisensitive cellular functions. PMID:11537958

  2. Integrated Nanoplasmonic Sensing for Cellular Functional Immunoanalysis Using Human Blood

    PubMed Central

    2015-01-01

    Localized surface plasmon resonance (LSPR) nanoplasmonic effects allow for label-free, real-time detection of biomolecule binding events on a nanostructured metallic surface with simple optics and sensing tunability. Despite numerous reports on LSPR bionanosensing in the past, no study thus far has applied the technique for a cytokine secretion assay using clinically relevant immune cells from human blood. Cytokine secretion assays, a technique to quantify intercellular-signaling proteins secreted by blood immune cells, allow determination of the functional response of the donor’s immune cells, thus providing valuable information about the immune status of the donor. However, implementation of LSPR bionanosensing in cellular functional immunoanalysis based on a cytokine secretion assay poses major challenges primarily owing to its limited sensitivity and a lack of sufficient sample handling capability. In this paper, we have developed a label-free LSPR biosensing technique to detect cell-secreted tumor necrosis factor (TNF)-α cytokines in clinical blood samples. Our approach integrates LSPR bionanosensors in an optofluidic platform that permits trapping and stimulation of target immune cells in a microfluidic chamber with optical access for subsequent cytokine detection. The on-chip spatial confinement of the cells is the key to rapidly increasing a cytokine concentration high enough for detection by the LSPR setup, thereby allowing the assay time and sample volume to be significantly reduced. We have successfully applied this approach first to THP-1 cells and then later to CD45 cells isolated directly from human blood. Our LSPR optofluidics device allows for detection of TNF-α secreted from cells as few as 1000, which translates into a nearly 100 times decrease in sample volume than conventional cytokine secretion assay techniques require. We achieved cellular functional immunoanalysis with a minimal blood sample volume (3 μL) and a total assay time 3 times

  3. Electrostatic bio-manipulation for the modification of cellular functions

    NASA Astrophysics Data System (ADS)

    Washizu, Masao

    2013-03-01

    The use of electrostatic field effects, including field-induced reversible-breakdown of the membrane and dielectrophoresis (DEP), in microfabricated structures are investigated. With the use of field constriction created by a micro-orifice whose diameter is smaller than the cells, controlled magnitude of pulsed voltage can be applied across the cell membrane regardless of the cell size, shape or orientation. As a result, the breakdown occurs reproducibly and with minimal invasiveness. The breakdown is used for two purposes, electroporation by which foreign substances can be fed into cells, and electrofusion which creates genetic and/or cytoplasmic mixture among two cells. When GFP plasmid is fed into MSC cell, the gene expression started within 2 hours, and finally observed in more than 50% of cells. For cell fusion, several ten percent fusion yield is achieved for most cell types, with the colony formation in several percents. Timing-controlled feeding foreign substances or mixing cellular contents, with high-yield and low-invasiveness, is expected to bring about a new technology for both genetic and epigenetic modifications of cellular functions, in such field as regenerative medicine.

  4. 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.

  5. Cardiac function in an endothermic fish: cellular mechanisms for overcoming acute thermal challenges during diving.

    PubMed

    Shiels, H A; Galli, G L J; Block, B A

    2015-02-01

    Understanding the physiology of vertebrate thermal tolerance is critical for predicting how animals respond to climate change. Pacific bluefin tuna experience a wide range of ambient sea temperatures and occupy the largest geographical niche of all tunas. Their capacity to endure thermal challenge is due in part to enhanced expression and activity of key proteins involved in cardiac excitation-contraction coupling, which improve cardiomyocyte function and whole animal performance during temperature change. To define the cellular mechanisms that enable bluefin tuna hearts to function during acute temperature change, we investigated the performance of freshly isolated ventricular myocytes using confocal microscopy and electrophysiology. We demonstrate that acute cooling and warming (between 8 and 28°C) modulates the excitability of the cardiomyocyte by altering the action potential (AP) duration and the amplitude and kinetics of the cellular Ca(2+) transient. We then explored the interactions between temperature, adrenergic stimulation and contraction frequency, and show that when these stressors are combined in a physiologically relevant way, they alter AP characteristics to stabilize excitation-contraction coupling across an acute 20°C temperature range. This allows the tuna heart to maintain consistent contraction and relaxation cycles during acute thermal challenges. We hypothesize that this cardiac capacity plays a key role in the bluefin tunas' niche expansion across a broad thermal and geographical range. PMID:25540278

  6. Cardiac function in an endothermic fish: cellular mechanisms for overcoming acute thermal challenges during diving

    PubMed Central

    Shiels, H. A.; Galli, G. L. J.; Block, B. A.

    2015-01-01

    Understanding the physiology of vertebrate thermal tolerance is critical for predicting how animals respond to climate change. Pacific bluefin tuna experience a wide range of ambient sea temperatures and occupy the largest geographical niche of all tunas. Their capacity to endure thermal challenge is due in part to enhanced expression and activity of key proteins involved in cardiac excitation–contraction coupling, which improve cardiomyocyte function and whole animal performance during temperature change. To define the cellular mechanisms that enable bluefin tuna hearts to function during acute temperature change, we investigated the performance of freshly isolated ventricular myocytes using confocal microscopy and electrophysiology. We demonstrate that acute cooling and warming (between 8 and 28°C) modulates the excitability of the cardiomyocyte by altering the action potential (AP) duration and the amplitude and kinetics of the cellular Ca2+ transient. We then explored the interactions between temperature, adrenergic stimulation and contraction frequency, and show that when these stressors are combined in a physiologically relevant way, they alter AP characteristics to stabilize excitation–contraction coupling across an acute 20°C temperature range. This allows the tuna heart to maintain consistent contraction and relaxation cycles during acute thermal challenges. We hypothesize that this cardiac capacity plays a key role in the bluefin tunas' niche expansion across a broad thermal and geographical range. PMID:25540278

  7. Characterizing genomic alterations in cancer by complementary functional associations.

    PubMed

    Kim, Jong Wook; Botvinnik, Olga B; Abudayyeh, Omar; Birger, Chet; Rosenbluh, Joseph; Shrestha, Yashaswi; Abazeed, Mohamed E; Hammerman, Peter S; DiCara, Daniel; Konieczkowski, David J; Johannessen, Cory M; Liberzon, Arthur; Alizad-Rahvar, Amir Reza; Alexe, Gabriela; Aguirre, Andrew; Ghandi, Mahmoud; Greulich, Heidi; Vazquez, Francisca; Weir, Barbara A; Van Allen, Eliezer M; Tsherniak, Aviad; Shao, Diane D; Zack, Travis I; Noble, Michael; Getz, Gad; Beroukhim, Rameen; Garraway, Levi A; Ardakani, Masoud; Romualdi, Chiara; Sales, Gabriele; Barbie, David A; Boehm, Jesse S; Hahn, William C; Mesirov, Jill P; Tamayo, Pablo

    2016-05-01

    Systematic efforts to sequence the cancer genome have identified large numbers of mutations and copy number alterations in human cancers. However, elucidating the functional consequences of these variants, and their interactions to drive or maintain oncogenic states, remains a challenge in cancer research. We developed REVEALER, a computational method that identifies combinations of mutually exclusive genomic alterations correlated with functional phenotypes, such as the activation or gene dependency of oncogenic pathways or sensitivity to a drug treatment. We used REVEALER to uncover complementary genomic alterations associated with the transcriptional activation of β-catenin and NRF2, MEK-inhibitor sensitivity, and KRAS dependency. REVEALER successfully identified both known and new associations, demonstrating the power of combining functional profiles with extensive characterization of genomic alterations in cancer genomes. PMID:27088724

  8. Estradiol-induced promotion of hepatocarcinogenesis in medaka: Relationship of foci of cellular alteration to neoplasia

    SciTech Connect

    Cooke, J.B.; Hinton, D.E.

    1995-12-31

    In some laboratory and field studies, female fish have higher prevalences of liver tumors than do males. The authors hypothesize gender and site-specific differences in prevalence are due to variable exposures of previously initiated fish to tumor modulating compounds. Estradiol, a growth promoter, increases incidences of hepatic tumors in carcinogen-treated rainbow trout and medaka (Oryzias latipes). Estradiol also increases incidences of hepatic foci of cellular alteration (FCA) in medaka. FCA are found in subadults of tumor-bearing feral populations. Lack of knowledge about the relationship of various phenotypes of FCA to eventual tumors, however, has prevented use of FCA as a biomarker. The authors examined fate and growth of liver FCA using a 2-step, initiation-promotion protocol. Three week old medaka were exposed to 200 ppm diethylnitrosamine (DEN) for 24 hr. and then fed 0.1 ppm 17-{beta}-estradiol (E2) continuously through sampling at weeks 4--26. Percent volume of FCA and morphometric characteristics of normal and focal hepatocytes, including numerical density and average hepatocyte volume were quantified using computer-assisted stereology. E2 increased percentage of liver occupied by DEN-initiated amphophilic, basophilic and eosinophilic FCA in both sexes. Focal parameters of young, DEN-initiated and estradiol-treated medaka were not reached until much later in fish given only DEN. Non-focal hepatocytes in estradiol-treated medaka were smaller and more numerous than in DEN-only counterparts. Morphometric analysis is quantitatively tracking the fate of specific phenotypes of FCA to determine their role in progression to cancer.

  9. Comprehensive Analysis of Temporal Alterations in Cellular Proteome of Bacillus subtilis under Curcumin Treatment

    PubMed Central

    Reddy, Panga Jaipal; Sinha, Sneha; Ray, Sandipan; Sathe, Gajanan J.; Chatterjee, Aditi; Prasad, T. S. Keshava; Dhali, Snigdha; Srikanth, Rapole; Panda, Dulal; Srivastava, Sanjeeva

    2015-01-01

    Curcumin is a natural dietary compound with antimicrobial activity against various gram positive and negative bacteria. This study aims to investigate the proteome level alterations in Bacillus subtilis due to curcumin treatment and identification of its molecular/cellular targets to understand the mechanism of action. We have performed a comprehensive proteomic analysis of B. subtilis AH75 strain at different time intervals of curcumin treatment (20, 60 and 120 min after the drug exposure, three replicates) to compare the protein expression profiles using two complementary quantitative proteomic techniques, 2D-DIGE and iTRAQ. To the best of our knowledge, this is the first comprehensive longitudinal investigation describing the effect of curcumin treatment on B. subtilis proteome. The proteomics analysis revealed several interesting targets such UDP-N-acetylglucosamine 1-carboxyvinyltransferase 1, putative septation protein SpoVG and ATP-dependent Clp protease proteolytic subunit. Further, in silico pathway analysis using DAVID and KOBAS has revealed modulation of pathways related to the fatty acid metabolism and cell wall synthesis, which are crucial for cell viability. Our findings revealed that curcumin treatment lead to inhibition of the cell wall and fatty acid synthesis in addition to differential expression of many crucial proteins involved in modulation of bacterial metabolism. Findings obtained from proteomics analysis were further validated using 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) assay for respiratory activity, resazurin assay for metabolic activity and membrane integrity assay by potassium and inorganic phosphate leakage measurement. The gene expression analysis of selected cell wall biosynthesis enzymes has strengthened the proteomics findings and indicated the major effect of curcumin on cell division. PMID:25874956

  10. Ocean warming alters cellular metabolism and induces mortality in fish early life stages: A proteomic approach.

    PubMed

    Madeira, D; Araújo, J E; Vitorino, R; Capelo, J L; Vinagre, C; Diniz, M S

    2016-07-01

    Climate change has pervasive effects on marine ecosystems, altering biodiversity patterns, abundance and distribution of species, biological interactions, phenology, and organisms' physiology, performance and fitness. Fish early life stages have narrow thermal windows and are thus more vulnerable to further changes in water temperature. The aim of this study was to address the sensitivity and underlying molecular changes of larvae of a key fisheries species, the sea bream Sparus aurata, towards ocean warming. Larvae were exposed to three temperatures: 18°C (control), 24°C (warm) and 30°C (heat wave) for seven days. At the end of the assay, i) survival curves were plotted for each temperature treatment and ii) entire larvae were collected for proteomic analysis via 2D gel electrophoresis, image analysis and mass spectrometry. Survival decreased with increasing temperature, with no larvae surviving at 30°C. Therefore, proteomic analysis was only carried out for 18°C and 24°C. Larvae up-regulated protein folding and degradation, cytoskeletal re-organization, transcriptional regulation and the growth hormone while mostly down-regulating cargo transporting and porphyrin metabolism upon exposure to heat stress. No changes were detected in proteins related to energetic metabolism suggesting that larval fish may not have the energetic plasticity needed to sustain cellular protection in the long-term. These results indicate that despite proteome modulation, S. aurata larvae do not seem able to fully acclimate to higher temperatures as shown by the low survival rates. Consequently, elevated temperatures seem to have bottleneck effects during fish early life stages, and future ocean warming can potentially compromise recruitment's success of key fisheries species. PMID:27062348

  11. AMPK Knockdown in Placental Trophoblast Cells Results in Altered Morphology and Function

    PubMed Central

    Carey, Erica A.K.; Albers, Renee E.; Doliboa, Savannah R.; Hughes, Martha; Wyatt, Christopher N.; Natale, David R.C.

    2014-01-01

    The placenta is a transient organ that develops upon the initiation of pregnancy and is essential for embryonic development and fetal survival. The rodent placenta consists of distinct lineages and includes cell types that are analogous to those that make up the human placenta. Trophoblast cells within the labyrinth layer, which lies closest to the fetus, fuse and come in contact with maternal blood, thus facilitating nutrient and waste exchange between the mother and the baby. Abnormalities of the placenta may occur as a result of cellular stress and have been associated with pregnancy-associated disorders: such as preeclampsia, intrauterine growth restriction, and placental insufficiency. Cellular stress has also been shown to alter proliferation and differentiation rates of trophoblast cells. This stress response is important for cell survival and ensures continued placental functionality. AMP-activated protein kinase is an important sensor of cellular metabolism and stress. To study the role of AMPK in the trophoblast cells, we used RNA interference to simultaneously knockdown levels of both the AMPK alpha isoforms, AMPKα1 and AMPKα2. SM10 trophoblast progenitor cells were transduced with AMPKα1/2 shRNA and stable clones were established to analyze the effects of AMPK knockdown on important cellular functions. Our results indicate that a reduction in AMPK levels causes alterations in cell morphology, growth rate, and nutrient transport, thus identifying an important role for AMPK in the regulation of placental trophoblast differentiation. PMID:25003940

  12. Misassembled mutant DeltaF508 CFTR in the distal secretory pathway alters cellular lipid trafficking.

    PubMed

    Gentzsch, Martina; Choudhury, Amit; Chang, Xiu-bao; Pagano, Richard E; Riordan, John R

    2007-02-01

    Most patients with cystic fibrosis (CF) have a single codon deletion (DeltaF508) in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) that impairs assembly of the multidomain glycoprotein. The mutant protein escapes endoplasmic reticulum (ER) quality control at low temperature, but is rapidly cleared from the distal secretory pathway and degraded in lysosomes. CF cells accumulate free cholesterol similar to Niemann-Pick disease type C cells. We show that this lipid alteration is caused by the presence of misassembled mutant CFTR proteins, including DeltaF508, in the distal secretory pathway rather than the absence of functional CFTR. By contrast, cholesterol distribution is not changed by either D572N CFTR, which does not mature even at low temperature, or G551D, which is processed normally but is inactive. On expression of the DeltaF508 mutant, cholesterol and glycosphingolipids accumulate in punctate endosomal structures and cholesterol esters are reduced, indicating a block in the translocation of cholesterol to the ER for esterification. This is overcome by Rab9 overexpression, resulting in clearance of accumulating intracellular cholesterol. Similar but less pronounced alterations in intracellular cholesterol distribution are observed on expression of a temperature-rescued mutant variant of the related ATP-binding cassette (ABC) protein multidrug resistance-associated protein 1 (MRP1). Thus, on escape from ER quality control, misassembled mutants of CFTR and MRP1 impair lipid homeostasis in endocytic compartments. PMID:17213331

  13. Alteration of somatotropic function by proinflammatory cytokines.

    PubMed

    Frost, R A; Lang, C H

    2004-01-01

    Infections direct amino acids away from growth and skeletal muscle accretion toward the hepatic synthesis of acute-phase proteins. The loss of skeletal muscle protein stores results in both a decrease in muscle function and an increase in mortality. In general, muscle protein synthesis is decreased in rodent models of sepsis, as well as after the injection of components of the bacterial cell wall, such as lipopolysaccharide. Although the overexpression of proinflammatory cytokines is known to hasten the loss of skeletal muscle protein, it is not known whether this represents a direct effect of cytokines or results from secondary changes in the IGF system. Plasma concentrations of IGF-I are dramatically lowered by infection in rats, mice, pigs, and steers. The drop in IGF-I often occurs despite an increase in the plasma concentration of somatotropin. Animals are therefore considered to be GH resistant. The IGF bioactivity is determined not only by the plasma concentration of the ligand, but also by IGFBP; IGFBP-3 is the most abundant of these binding proteins and undergoes proteolysis during some catabolic states. In contrast to IGFBP-3, the plasma concentration of inhibitory IGFBP, such as IGFBP-1, is increased during infection. Insulin-like growth factor-binding protein-1 accumulates in skeletal muscle, where it can potentially inhibit IGF-dependent protein synthesis. Insulin-like growth factor-I and IGFBP-1 are regulated at the level of gene transcription by proinflammatory cytokines. Recent studies demonstrate that bacterial components that activate immune cells also activate the innate immune response in skeletal muscle. Lipopolysaccharide increases proinflammatory cytokine messenger RNA expression in muscle from control mice, but not from mice with a mutation in the lipopolysaccharide receptor. Lipopolysaccharide also increases cytokine expression in human and mouse myoblasts. Local expression of cytokines in skeletal muscle may negatively regulate the

  14. Experimentally induced diabetes causes glial activation, glutamate toxicity and cellular damage leading to changes in motor function

    PubMed Central

    Nagayach, Aarti; Patro, Nisha; Patro, Ishan

    2014-01-01

    Behavioral impairments are the most empirical consequence of diabetes mellitus documented in both humans and animal models, but the underlying causes are still poorly understood. As the cerebellum plays a major role in coordination and execution of the motor functions, we investigated the possible involvement of glial activation, cellular degeneration and glutamate transportation in the cerebellum of rats, rendered diabetic by a single injection of streptozotocin (STZ; 45 mg/kg body weight; intraperitoneally). Motor function alterations were studied using Rotarod test (motor coordination) and grip strength (muscle activity) at 2nd, 4th, 6th, 8th, 10th, and 12th week post-diabetic confirmation. Scenario of glial (astroglia and microglia) activation, cell death and glutamate transportation was gaged using immunohistochemistry, histological study and image analysis. Cellular degeneration was clearly demarcated in the diabetic cerebellum. Glial cells were showing sequential and marked activation following diabetes in terms of both morphology and cell number. Bergmann glial cells were hypertrophied and distorted. Active caspase-3 positive apoptotic cells were profoundly present in all three cerebellar layers. Reduced co-labeling of GLT-1 and GFAP revealed the altered glutamate transportation in cerebellum following diabetes. These results, exclusively derived from histology, immunohistochemistry and cellular quantification, provide first insight over the associative reciprocity between the glial activation, cellular degeneration and reduced glutamate transportation, which presumably lead to the behavioral alterations following STZ-induced diabetes. PMID:25400546

  15. Altered calmodulin activity in fluphenazine-resistant mutant strains. Pleiotropic effect on development and cellular organization in Volvox carteri.

    PubMed

    Kurn, N; Sela, B A

    1981-12-01

    Genetically altered calmodulin activity in spontaneously derived mutant strains, which were selected for resistance to the toxic effect of a specific inhibitor, the phenothiazine drug fluphenazine, is demonstrated. Partially purified calmodulin preparations from wild-type and fluphenazine-resistant strains of the multicellular alga Volvox carteri, were tested for the ability to activate Ca2+-ATPase of the erythrocyte membranes, and the inhibition of this stimulatory activity by fluphenazine. Unlike the preparation obtained from wild-type cells, mutant calmodulin is shown to be insensitive to fluphenazine inhibition, in one case, and calmodulin from another strain was found to be inactive in vitro, i.e. it did not activate Ca2+-ATPase. The pleiotropic phenotype of the spontaneously derived mutant strains involved aberrant multicellular organization and hormone-independent commitment of the multipotent asexual reproductive cells, gonodia, to sexual development. These results clearly implicate calmodulin in the control of development and morphogenesis in this simple multicellular eukaryote. In addition, intracellular inhibition of calmodulin in wild-type cells is shown to block the morphogenic process of embryo inversion and to arrest motility. The availability of mutant calmodulin will facilitate further investigation of the role of this ubiquitous regulatory protein in the control of development and differentiation in multicellular eukarytes, as well as the fine structure/function relationship with regard to calmodulin modulation of a wide variety of cellular processes. PMID:6459931

  16. Cellular functions of vaults and their involvement in multidrug resistance.

    PubMed

    Steiner, E; Holzmann, K; Elbling, L; Micksche, M; Berger, W

    2006-08-01

    Vaults are evolutionary highly conserved ribonucleoprotein (RNP) particles with a hollow barrel-like structure. They are 41 x 73 nm in size and are composed of multiple copies of three proteins and small untranslated RNA (vRNA). The main component of vaults represents the 110 kDa major vault protein (MVP), whereas the two minor vault proteins comprise the 193 kDa vault poly(ADP-ribose) polymerase (VPARP) and the 240 kDa telomerase-associated protein-1 (TEP1). Vaults are abundantly present in the cytoplasm of eukaryotic cells and they were found to be associated with cytoskeletal elements as well as occasionally with the nuclear envelope. Vaults and MVP have been associated with several cellular processes which are also involved in cancer development like cell motility and differentiation. Due to the over-expression of MVP (also termed lung resistance-related protein or LRP) in several P-glycoprotein (P-gp)-negative chemoresistant cancer cell lines, vaults have been linked to multidrug resistance (MDR). Accordingly, high levels of MVP were found in tissues chronically exposed to xenobiotics. In addition, the expression of MVP correlated with the degree of malignancy in certain cancer types, suggesting a direct involvement in tumor development and/or progression. Based on the finding that MVP binds several phosphatases and kinases including PTEN, SHP-2 as well as Erk, evidence is accumulating that MVP might be involved in the regulation of important cell signalling pathways including the PI3K/Akt and the MAPK pathways. In this review we summarize the current knowledge concerning the vault particle and discuss its possible cellular functions, focusing on the role of vaults in chemotherapy resistance. PMID:16918321

  17. The alteration of profile analysis to accommodate testing functions

    NASA Technical Reports Server (NTRS)

    Myers, R. H.

    1979-01-01

    The development of a methodology was studied for testing differences among several pilot functions, where the data points represent averages at various frequencies. Topics discussed include: basic assumptions, hypothesis, profile analysis, alteration of profile analysis to accommodate testing functions, test and procedures, and power of tests.

  18. Compact Biocompatible Quantum Dots Functionalized for Cellular Imaging

    PubMed Central

    Liu, Wenhao; Howarth, Mark; Greytak, Andrew B.; Zheng, Yi; Nocera, Daniel G.; Ting, Alice Y.; Bawendi, Moungi G.

    2009-01-01

    We present a family of water-soluble quantum dots (QDs) that exhibit low nonspecific binding to cells, small hydrodynamic diameter, tunable surface charge, high quantum yield, and good solution stability across a wide pH range. These QDs are amenable to covalent modification via simple carbodiimide coupling chemistry, which is achieved by functionalizing the surface of QDs with a new class of heterobifunctional ligands incorporating dihydrolipoic acid, a short poly(ethylene glycol) (PEG) spacer, and an amine or carboxylate terminus. The covalent attachment of molecules is demonstrated by appending a rhodamine dye to form a QD-dye conjugate exhibiting fluorescence resonance energy transfer (FRET). High-affinity labeling is demonstrated by covalent attachment of streptavidin, thus enabling the tracking of biotinylated epidermal growth factor (EGF) bound to EGF receptor on live cells. In addition, QDs solubilized with the heterobifunctional ligands retain their metal-affinity driven conjugation chemistry with polyhistidine-tagged proteins. This dual functionality is demonstrated by simultaneous covalent attachment of a rhodamine FRET acceptor and binding of polyhistidine-tagged streptavidin on the same nanocrystal to create a targeted QD, which exhibits dual-wavelength emission. Such emission properties could serve as the basis for ratiometric sensing of the cellular receptor’s local chemical environment. PMID:18177042

  19. Membrane-Based Functions in the Origin of Cellular Life

    NASA Technical Reports Server (NTRS)

    Wilson, Michael A.

    2003-01-01

    How simple membrane peptides performed such essential proto-cellular functions as transport of ions and organic matter across membranes separating the interior of the cell from the environment, capture and utilization of energy, and transduction of environmental signals, is a key question in protobiological evolution. On the basis of detailed, molecular-level computer simulations we investigate how these peptides insert into membranes, self-assemble into higher-order structures and acquire functions. We have studied the insertion of an a-helical peptide containing leucine (L) and serine (S) of the form (LSLLLSL)S into a model membrane. The transmembrane state is metastable, and approximately 15 kcal/mol is required to insert the peptide into the membrane. Investigations of dimers formed by (LSLLLSL)S and glycophorin A demonstrate how the favorable free energy of helix association can offset the unfavorable free energy of insertion, leading to self- assembly of peptide helices in the membrane. An example of a self-assembled structure is the tetrameric transmembrane pore of the influenza virus M2 protein, which is an efficient and selective voltage-gated proton channel. Our simulations explain the gating mechanism and provide guidelines how to reengineering the channel to act as a simple proton pump. In general, emergence of integral membrane proteins appears to be quite feasible and may be easier to envision than the emergence of water-soluble proteins.

  20. Activation of the oncogenic potential of the avian cellular src protein by specific structural alteration of the carboxy terminus.

    PubMed Central

    Reynolds, A B; Vila, J; Lansing, T J; Potts, W M; Weber, M J; Parsons, J T

    1987-01-01

    The role of tyrosine phosphorylation in the regulation of tyrosine protein kinase activity was investigated using site-directed mutagenesis to alter the structure and environment of the three tyrosine residues present in the C terminus of avian pp60c-src. Mutations that change Tyr 527 to Phe or Ser activate in vivo tyrosine protein kinase activity and induce cellular transformation of chicken cells in culture. In contrast, alterations of tyrosine residues present at positions 511 or 519 in c-src do not induce transformation or in vivo tyrosine protein kinase activity. Amber mutations, which alter the structure of the pp60c-src C terminus by inducing premature termination of the c-src protein at either residue 518 or 523 also induce morphological transformation and increase in vivo tyrosine phosphorylation, whereas removal of the last four residues of c-src by chain termination at residue 530 does not alter the kinase activity or the biological activity of the resultant c-src protein. We conclude from these studies that C-terminal alterations which either remove or replace Tyr 527 serve to activate the c-src protein resulting in cellular transformation and increased in vivo tyrosine protein kinase activity. Images Fig. 2. Fig. 3. Fig. 4. PMID:2822389

  1. Coxsackievirus B3-Induced Cellular Protrusions: Structural Characteristics and Functional Competence▿†

    PubMed Central

    Paloheimo, Outi; Ihalainen, Teemu O.; Tauriainen, Sisko; Välilehto, Outi; Kirjavainen, Sanna; Niskanen, Einari A.; Laakkonen, Johanna P.; Hyöty, Heikki; Vihinen-Ranta, Maija

    2011-01-01

    Virus-induced alterations in cell morphology play important roles in the viral life cycle. To examine the intracellular events of coxsackievirus B3 (CVB3) infection, green monkey kidney (GMK) cells were either inoculated with the virus or transfected with the viral RNA. Various microscopic and flow cytometric approaches demonstrated the emergence of CVB3 capsid proteins at 8 h posttransfection, followed by morphological transformation of the cells. The morphological changes included formation of membranous protrusions containing viral capsids, together with microtubules and actin. Translocation of viral capsids into these protrusions was sensitive to cytochalasin D, suggesting the importance of actin in the process. Three-dimensional (3D) live-cell imaging demonstrated frequent contacts between cellular protrusions and adjacent cells. Markedly, in spite of an increase in the cellular viral protein content starting 8 h postinfection, no significant decrease in cell viability or increase in the amount of early apoptotic markers was observed by flow cytometry by 28 h postinfection. Comicroinjection of viral RNA and fluorescent dextran in the presence of neutralizing virus antibody suggested that these protrusions mediated the spread of infection from one cell to another prior to virus-induced cell lysis. Altogether, the CVB3-induced cellular protrusions could function as a hitherto-unknown nonlytic mechanism of cell-to-cell transmission exploited by enteroviruses. PMID:21525342

  2. BRCA1 Haploinsufficiency Leads to Altered Expression of Genes Involved in Cellular Proliferation and Development

    PubMed Central

    Feilotter, Harriet E.; Michel, Claire; Uy, Paolo; Bathurst, Lauren; Davey, Scott

    2014-01-01

    The assessment of BRCA1 and BRCA2 coding sequences to identify pathogenic mutations associated with inherited breast/ovarian cancer syndrome has provided a method to identify high-risk individuals, allowing them to seek preventative treatments and strategies. However, the current test is expensive, and cannot differentiate between pathogenic variants and those that may be benign. Focusing only on one of the two BRCA partners, we have developed a biological assay for haploinsufficiency of BRCA1. Using a series of EBV-transformed cell lines, we explored gene expression patterns in cells that were BRCA1 wildtype compared to those that carried (heterozygous) BRCA1 pathogenic mutations. We identified a subset of 43 genes whose combined expression pattern is a sensitive predictor of BRCA1 status. The gene set was disproportionately made up of genes involved in cellular differentiation, lending credence to the hypothesis that single copy loss of BRCA1 function may impact differentiation, rendering cells more susceptible to undergoing malignant processes. PMID:24950059

  3. Hijacking of Host Cellular Functions by an Intracellular Parasite, the Microsporidian Anncaliia algerae

    PubMed Central

    Panek, Johan; El Alaoui, Hicham; Mone, Anne; Urbach, Serge; Demettre, Edith; Texier, Catherine; Brun, Christine; Zanzoni, Andreas; Peyretaillade, Eric; Parisot, Nicolas; Lerat, Emmanuelle; Peyret, Pierre; Delbac, Frederic; Biron, David G.

    2014-01-01

    Intracellular pathogens including bacteria, viruses and protozoa hijack host cell functions to access nutrients and to bypass cellular defenses and immune responses. These strategies have been acquired through selective pressure and allowed pathogens to reach an appropriate cellular niche for their survival and growth. To get new insights on how parasites hijack host cellular functions, we developed a SILAC (Stable Isotope Labeling by Amino Acids in Cell culture) quantitative proteomics workflow. Our study focused on deciphering the cross-talk in a host-parasite association, involving human foreskin fibroblasts (HFF) and the microsporidia Anncaliia algerae, a fungus related parasite with an obligate intracellular lifestyle and a strong host dependency. The host-parasite cross-talk was analyzed at five post-infection times 1, 6, 12 and 24 hours post-infection (hpi) and 8 days post-infection (dpi). A significant up-regulation of four interferon-induced proteins with tetratricopeptide repeats IFIT1, IFIT2, IFIT3 and MX1 was observed at 8 dpi suggesting a type 1 interferon (IFN) host response. Quantitative alteration of host proteins involved in biological functions such as signaling (STAT1, Ras) and reduction of the translation activity (EIF3) confirmed a host type 1 IFN response. Interestingly, the SILAC approach also allowed the detection of 148 A. algerae proteins during the kinetics of infection. Among these proteins many are involved in parasite proliferation, and an over-representation of putative secreted effectors proteins was observed. Finally our survey also suggests that A. algerae could use a transposable element as a lure strategy to escape the host innate immune system. PMID:24967735

  4. Hijacking of host cellular functions by an intracellular parasite, the microsporidian Anncaliia algerae.

    PubMed

    Panek, Johan; El Alaoui, Hicham; Mone, Anne; Urbach, Serge; Demettre, Edith; Texier, Catherine; Brun, Christine; Zanzoni, Andreas; Peyretaillade, Eric; Parisot, Nicolas; Lerat, Emmanuelle; Peyret, Pierre; Delbac, Frederic; Biron, David G

    2014-01-01

    Intracellular pathogens including bacteria, viruses and protozoa hijack host cell functions to access nutrients and to bypass cellular defenses and immune responses. These strategies have been acquired through selective pressure and allowed pathogens to reach an appropriate cellular niche for their survival and growth. To get new insights on how parasites hijack host cellular functions, we developed a SILAC (Stable Isotope Labeling by Amino Acids in Cell culture) quantitative proteomics workflow. Our study focused on deciphering the cross-talk in a host-parasite association, involving human foreskin fibroblasts (HFF) and the microsporidia Anncaliia algerae, a fungus related parasite with an obligate intracellular lifestyle and a strong host dependency. The host-parasite cross-talk was analyzed at five post-infection times 1, 6, 12 and 24 hours post-infection (hpi) and 8 days post-infection (dpi). A significant up-regulation of four interferon-induced proteins with tetratricopeptide repeats IFIT1, IFIT2, IFIT3 and MX1 was observed at 8 dpi suggesting a type 1 interferon (IFN) host response. Quantitative alteration of host proteins involved in biological functions such as signaling (STAT1, Ras) and reduction of the translation activity (EIF3) confirmed a host type 1 IFN response. Interestingly, the SILAC approach also allowed the detection of 148 A. algerae proteins during the kinetics of infection. Among these proteins many are involved in parasite proliferation, and an over-representation of putative secreted effectors proteins was observed. Finally our survey also suggests that A. algerae could use a transposable element as a lure strategy to escape the host innate immune system. PMID:24967735

  5. Altered resting state functional network connectivity in children absence epilepsy.

    PubMed

    Li, Qifu; Cao, Weifang; Liao, Xiaoping; Chen, Zhibin; Yang, Tianhua; Gong, Qiyong; Zhou, Dong; Luo, Cheng; Yao, Dezhong

    2015-07-15

    Altered functional connectivity has been associated with the influence of epileptic activity. Abnormalities in connectivity, particularly in dorsal attention (DAN), salience (SN) and default mode (DMN) networks, might contribute to the loss of consciousness during seizures and cognitive deficits in patients with children absence epilepsy (CAE). The objective of the present study was to identify whether the functional network connectivity (FNC) is changed between patients with CAE and healthy controls. Using independent component analysis, twelve resting state networks (RSNs) were identified in resting state functional magnetic resonance imaging data sets in eighteen CAE patients and twenty-one healthy controls. Analyses of the group differences in FNC strength were conducted, controlling for age and gender effects. The findings showed that some functional networks were clustered into two subgroups, correlated within subgroups and antagonized with each other. Compared with the controls, patients with CAE demonstrated abnormal FNC strength among three networks: DMN, DAN and SN. In addition, the antagonism of two subgroups was altered. These results might reflect the underlying neuronal functional impairment or altered integration among these RSNs in CAE, suggesting that the abnormal functional connectivity is likely to imply the pathological mechanism associated with the accumulative influence of epileptic activity. These findings contribute to the understanding of the behavior abnormality in CAE, such as disturbed executive and attentional functions and the loss of consciousness during absence seizures. PMID:25982500

  6. Efflux Pump Control Alters Synthetic Gene Circuit Function.

    PubMed

    Diao, Junchen; Charlebois, Daniel A; Nevozhay, Dmitry; Bódi, Zoltán; Pál, Csaba; Balázsi, Gábor

    2016-07-15

    Synthetic biology aims to design new biological systems for predefined purposes, such as the controlled secretion of biofuels, pharmaceuticals, or other chemicals. Synthetic gene circuits regulating an efflux pump from the ATP-binding cassette (ABC) protein family could achieve this. However, ABC efflux pumps can also drive out intracellular inducer molecules that control the gene circuits. This will introduce an implicit feedback that could alter gene circuit function in ways that are poorly understood. Here, we used two synthetic gene circuits inducible by tetracycline family molecules to regulate the expression of a yeast ABC pump (Pdr5p) that pumps out the inducer. Pdr5p altered the dose-responses of the original gene circuits substantially in Saccharomyces cerevisiae. While one aspect of the change could be attributed to the efflux pumping function of Pdr5p, another aspect remained unexplained. Quantitative modeling indicated that reduced regulator gene expression in addition to efflux pump function could fully explain the altered dose-responses. These predictions were validated experimentally. Overall, we highlight how efflux pumps can alter gene circuit dynamics and demonstrate the utility of mathematical modeling in understanding synthetic gene circuit function in new circumstances. PMID:27111147

  7. Production of HIV Particles Is Regulated by Altering Sub-Cellular Localization and Dynamics of Rev Induced by Double-Strand RNA Binding Protein

    PubMed Central

    Urcuqui-Inchima, Silvio; Patiño, Claudia; Zapata, Ximena; García, María Patricia; Arteaga, José; Chamot, Christophe; Kumar, Ajit; Hernandez-Verdun, Danièle

    2011-01-01

    Human immunodeficiency virus (HIV)-1 encoded Rev is essential for export from the nucleus to the cytoplasm, of unspliced and singly spliced transcripts coding for structural and nonstructural viral proteins. This process is spatially and temporally coordinated resulting from the interactions between cellular and viral proteins. Here we examined the effects of the sub-cellular localization and dynamics of Rev on the efficiency of nucleocytoplasmic transport of HIV-1 Gag transcripts and virus particle production. Using confocal microscopy and fluorescence recovery after bleaching (FRAP), we report that NF90ctv, a cellular protein involved in Rev function, alters both the sub-cellular localization and dynamics of Rev in vivo, which drastically affects the accumulation of the viral protein p24. The CRM1–dependent nuclear export of Gag mRNA linked to the Rev Response Element (RRE) is dependent on specific domains of the NF90ctv protein. Taken together, our results demonstrate that the appropriate intracellular localization and dynamics of Rev could regulate Gag assembly and HIV-1 replication. PMID:21364984

  8. Renal function alterations during skeletal muscle disuse in simulated microgravity

    NASA Technical Reports Server (NTRS)

    Tucker, Bryan J.

    1992-01-01

    This project was to examine the alterations in renal functions during skeletal muscle disuse in simulated microgravity. Although this area could cover a wide range of investigative efforts, the limited funding resulted in the selection of two projects. These projects would result in data contributing to an area of research deemed high priority by NASA and would address issues of the alterations in renal response to vasoactive stimuli during conditions of skeletal muscle disuse as well as investigate the contribution of skeletal muscle disuse, conditions normally found in long term human exposure to microgravity, to the balance of fluid and macromolecules within the vasculature versus the interstitium. These two projects selected are as follows: investigate the role of angiotensin 2 on renal function during periods of simulated microgravity and skeletal muscle disuse to determine if the renal response is altered to changes in circulating concentrations of angiotensin 2 compared to appropriate controls; and determine if the shift of fluid balance from vasculature to the interstitium, the two components of extracellular fluid volume, that occur during prolonged exposure to microgravity and skeletal muscle disuse is a result, in part, to alterations in the fluid and macromolecular balance in the peripheral capillary beds, of which the skeletal muscle contains the majority of recruitment capillaries. A recruitment capillary bed would be most sensitive to alterations in Starling forces and fluid and macromolecular permeability.

  9. Preterm birth alters neonatal, functional rich club organization.

    PubMed

    Scheinost, Dustin; Kwon, Soo Hyun; Shen, Xilin; Lacadie, Cheryl; Schneider, Karen C; Dai, Feng; Ment, Laura R; Constable, R Todd

    2016-07-01

    Alterations in neural networks are associated with the cognitive difficulties of the prematurely born. Using functional magnetic resonance imaging, we analyzed functional connectivity for preterm (PT) and term neonates at term equivalent age. Specifically, we constructed whole-brain networks and examined rich club (RC) organization, a common construct among complex systems where important (or "rich") nodes connect preferentially to other important nodes. Both PT and term neonates showed RC organization with PT neonates exhibiting significantly reduced connections between these RC nodes. Additionally, PT neonates showed evidence of weaker functional segregation. Our results suggest that PT birth is associated with fundamental changes of functional organization in the developing brain. PMID:26341628

  10. Multiscale evaluation of cellular adhesion alteration and cytoskeleton remodeling by magnetic bead twisting.

    PubMed

    Isabey, Daniel; Pelle, Gabriel; André Dias, Sofia; Bottier, Mathieu; Nguyen, Ngoc-Minh; Filoche, Marcel; Louis, Bruno

    2016-08-01

    Cellular adhesion forces depend on local biological conditions meaning that adhesion characterization must be performed while preserving cellular integrity. We presently postulate that magnetic bead twisting provides an appropriate stress, i.e., basically a clamp, for assessment in living cells of both cellular adhesion and mechanical properties of the cytoskeleton. A global dissociation rate obeying a Bell-type model was used to determine the natural dissociation rate ([Formula: see text]) and a reference stress ([Formula: see text]). These adhesion parameters were determined in parallel to the mechanical properties for a variety of biological conditions in which either adhesion or cytoskeleton was selectively weakened or strengthened by changing successively ligand concentration, actin polymerization level (by treating with cytochalasin D), level of exerted stress (by increasing magnetic torque), and cell environment (by using rigid and soft 3D matrices). On the whole, this multiscale evaluation of the cellular and molecular responses to a controlled stress reveals an evolution which is consistent with stochastic multiple bond theories and with literature results obtained with other molecular techniques. Present results confirm the validity of the proposed bead-twisting approach for its capability to probe cellular and molecular responses in a variety of biological conditions. PMID:26459324

  11. Development of mechano-responsive polymeric scaffolds using functionalized silica nano-fillers for the control of cellular functions.

    PubMed

    Griffin, Michelle; Nayyer, Leila; Butler, Peter E; Palgrave, Robert G; Seifalian, Alexander M; Kalaskar, Deepak M

    2016-08-01

    We demonstrate an efficient method to produce mechano-responsive polymeric scaffolds which can alter cellular functions using two different functionalized (OH and NH2) silica nano-fillers. Fumed silica-hydroxyl and fumed silica-amine nano-fillers were mixed with a biocompatible polymer (POSS-PCU) at various wt% to produce scaffolds. XPS and mechanical testing demonstrate that bulk mechanical properties are modified without changing the scaffold's surface chemistry. Mechanical testing showed significant change in bulk properties of POSS-PCU scaffolds with an addition of silica nanofillers as low as 1% (P<0.01). Scaffolds modified with NH2 silica showed significantly higher bulk mechanical properties compared to the one modified with the OH group. Enhanced cell adhesion, proliferation and collagen production over 14days were observed on scaffolds with higher bulk mechanical properties (NH2) compared to those with lower ones (unmodified and OH modified) (P<0.05) during in vitro analysis. This study provides an effective method of manufacturing mechano-responsive polymeric scaffolds, which can help to customize cellular responses for biomaterial applications. PMID:27013128

  12. PHYSIOLOGY AND ENDOCRINOLOGY SYMPOSIUM: Cellular and molecular mechanisms of heat stress related to bovine ovarian function.

    PubMed

    Roth, Z

    2015-05-01

    In light of the intensive genetic selection for high milk production and the onset of global warming, it seems that the reduced fertility of lactating cows during the summer will worsen in coming years. Although not entirely clear, the mechanism appears to be multifactorial in nature. It includes alterations in follicular development, depression of follicular dominance, and impairment of steroidogenesis and gonadotropin secretion. Heat-induced perturbations in the physiology of the follicle-enclosed oocyte have also been documented, expressed by impaired cleavage rate and reduced developmental competence. With respect to the oocyte, alterations include an increase in PUFA in the membrane, reactive oxygen species, ceramide formation and caspase activity, and induction of apoptosis via the sphingomyelin and/or mitochondrial pathways. New insight into cellular and molecular alterations has revealed that heat induces perturbations in both nuclear and cytoplasmic maturation events, such as resumption of meiosis, metaphase II plate formation, cytoskeleton rearrangement, and translocation of cortical granules. Alterations in mitochondrial distribution (i.e., low proportion of category I mitochondria) and function (i.e., low membrane potential) have recently been reported for oocytes collected during the summer. These were associated with impaired expression of both nuclear (succinate dehydrogenase subunit [SDHD], adenosine triphosphate [ATP] synthase subunit beta [ATP5B]), mitochondrially NADH dehydrogenase subunit 2 (ND2), and mitochondiral (cytochrome c oxidase subunit II [MT-CO2] and cytochrome b [MT-CYB]) genes that are crucial in the mitochondrial respiratory chain. In addition, season-induced alteration in the stored maternal mRNA has been documented, expressed by reduced transcript levels (oocyte maturation factor MOS [C-MOS], growth differentiation factor 9 [GDF9], POU domain class 5 transcription factor 1 [POU5F1], and glyceraldehyde-3-phosphate dehydrogenase

  13. Review: 2-mercaptoethanol alteration of in vitro immune functions of species other than murine.

    PubMed

    Click, Robert E

    2014-01-15

    Descriptions that organosulfurs could alter biologically relevant cellular functions began some 40years ago when cell mediated and humoral murine in vitro immune responses were reported to be dramatically enhanced by any of four xenobiotic, sulfhydryl compounds-2-mercaptoethanol (2-ME), dithiothreitol, glutathione, and l-cysteine; the most effective of the four was 2-ME. These findings triggered a plethora of reports defining 2-ME benefits for a multitude of immunological processes, primarily with murine models. This led to investigations on 2-ME alterations of (a) immune functions in other species, (b) activities of other cell-types, and (c) in situ diseases. In addition, the early findings may have been instrumental in the identification of the previously undefined anticarcinogenic chemicals in specific foods as organosulfurs. Outside the plant organosulfurs, there are no comprehensive reviews of these areas to help define mechanisms by which organosulfurs function as well as identify potential alternative uses. Therefore, the present review will focus on 2-ME alterations of in vitro immune functions in species other than murine; namely, fish, amphibian, reptile, avian, whales, dolphins, rat, hamster, rabbit, guinea pig, feline, canine, porcine, ovine, bovine, and human. Processes, some unique to a given species, were in general, enhanced and in some cases dependent upon the presence of 2-ME. The largest benefits occurred in media that were serum free, followed by those in autologous serum and then fetal bovine serum supplemented medium. Concentrations of 2-ME were generally in the low μM range, with exceptions of those for salamander (20mM), turtles (70mM) and dolphins (7mM). The few studies designed to assess mechanisms found that changes induced by 2-ME were generally accompanied by alterations of reduced/oxidized glutathione cellular concentrations. The major benefit for most studies, however, was to increase the sensitivity of the culture environment, which

  14. A priming dose of protons alters the early cardiac cellular and molecular response to 56Fe irradiation

    NASA Astrophysics Data System (ADS)

    Ramadan, Samy S.; Sridharan, Vijayalakshmi; Koturbash, Igor; Miousse, Isabelle R.; Hauer-Jensen, Martin; Nelson, Gregory A.; Boerma, Marjan

    2016-02-01

    Purpose: Recent evidence suggests that the heart may be injured by ionizing radiation at lower doses than was previously thought. This raises concerns about the cardiovascular risks from exposure to radiation during space travel. Since space travel is associated with exposure to both protons from solar particle events and heavy ions from galactic cosmic rays, we here examined the effects of a "priming" dose of protons on the cardiac cellular and molecular response to a "challenge" dose of 56Fe in a mouse model. Methods: Male C57BL/6 mice at 10 weeks of age were exposed to sham-irradiation, 0.1 Gy of protons (150 MeV), 0.5 Gy of 56Fe (600 MeV/n), or 0.1 Gy of protons 24 hours prior to 0.5 Gy of 56Fe. Hearts were obtained at 7 days post-irradiation and western-blots were used to determine protein markers of cardiac remodeling, inflammatory infiltration, and cell death. Results: Exposure to 56Fe caused an increase in expression of α-smooth muscle cell actin, collagen type III, the inflammatory cell markers mast cell tryptase, CD2 and CD68, the endothelial glycoprotein thrombomodulin, and cleaved caspase 3. Of all proteins investigated, protons at a dose of 0.1 Gy induced a small increase only in cleaved caspase 3 levels. On the other hand, exposure to protons 24 hours before 56Fe prevented all of the responses to 56Fe. Conclusions: This study shows that a low dose of protons may prime the heart to respond differently to a subsequent challenge dose of heavy ions. Further investigation is required to identify responses at additional time points, consequences for cardiac function, threshold dose levels, and mechanisms by which a proton priming dose may alter the response to heavy ions.

  15. Endurance exercise alters cellular immune status and resistin concentrations in men suffering from non-insulin-dependent type 2 diabetes.

    PubMed

    Wenning, P; Kreutz, T; Schmidt, A; Opitz, D; Graf, C; Voss, S; Bloch, W; Brixius, K

    2013-08-01

    It has been demonstrated that alterations of adipocytokines can alter immune status in type 2 diabetes. The present study investigated changes of adipocytokine plasma concentrations and cellular immune status in overweight men, suffering from non-insulin dependent type 2 diabetes (n=14, age 61.0±8.7 years, BMI 31.1±3.5 kg/cm2). Subjects underwent a 3 months endurance exercise intervention (twice per week for up to 45 min) cycling at a heart rate corresponding to a 2 mmol/l lactate threshold. Before and after the intervention testing for adipocytokines (leptin, adiponectin, resistin) and cellular immune status (including T memory-cells and regulative T-cells) was performed by RIA and FACS accordingly.The exercise intervention improved anthropometric and metabolic parameters of all subjects. We observed a significant decline for resistin and for the CD19+ B-cells. The CD4+CD25+CD127low Treg-cells decreased, however not statistically significant. All other parameters remained unchanged.In conclusion, even though only training twice a week, the exercise affected parts of the cellular immune system as well as resistin levels in men suffering from non-insulin dependent type 2 diabetes. PMID:24026829

  16. Alteration of rat polymorphonuclear leukocyte function after thermal injury.

    PubMed

    Gruber, D F; D'Alesandro, M M

    1989-01-01

    One portion of host defense to bacterial challenge(s) involves the activation and infiltration of endogenous polymorphonuclear leukocytes. Thermal injuries are frequently associated with immunologic abnormalities including alterations of polymorphonuclear leukocyte-associated nonspecific resistance. We examined isolated peripheral rat polymorphonuclear leukocytes for alterations in membrane potential, oxidative capability, and locomotor function after the experimental application of 20% full-thickness body surface area thermal injury. Thermal injury resulted in significant reductions of peripheral red blood cell concentration(s) and increases in leukocyte and platelet concentrations for 42 days after injury. In addition to the quantitative changes, polymorphonuclear leukocytes also demonstrated altered qualitative functions. Compared with phorbol myristate acetate-induced activation of normal cells, polymorphonuclear leukocyte membranes from thermal-injured animals were electrophysiologically less responsive for 3 weeks after injury. The ability of polymorphonuclear leukocytes to produce intracellular H2O2, a measure of oxidative function, was also significantly decreased for 7 days after injury. The paradox in this paradigm of thermal injury was the demonstration of peripheral polymorphonuclear leukocyte quantitative increases with concurrent significant qualitative impairment. Qualitative lesions included altered states of membrane depolarization and depressed oxidative capability that may individually, or collectively, reduce nonspecific immune capabilities of the host to levels that are inadequate to combat infection. PMID:2793916

  17. Extinction order and altered community structure rapidly disrupt ecosystem functioning.

    PubMed

    Larsen, Trond H; Williams, Neal M; Kremen, Claire

    2005-05-01

    By causing extinctions and altering community structure, anthropogenic disturbances can disrupt processes that maintain ecosystem integrity. However, the relationship between community structure and ecosystem functioning in natural systems is poorly understood. Here we show that habitat loss appeared to disrupt ecosystem functioning by affecting extinction order, species richness and abundance. We studied pollination by bees in a mosaic of agricultural and natural habitats in California and dung burial by dung beetles on recently created islands in Venezuela. We found that large-bodied bee and beetle species tended to be both most extinction-prone and most functionally efficient, contributing to rapid functional loss. Simulations confirmed that extinction order led to greater disruption of function than predicted by random species loss. Total abundance declined with richness and also appeared to contribute to loss of function. We demonstrate conceptually and empirically how the non-random response of communities to disturbance can have unexpectedly large functional consequences. PMID:21352458

  18. Tissue and cellular alterations in Asian clam (Potamocorbula amurensis) from San Francisco Bay: toxicological indicators of exposure and effect?

    PubMed

    Clark, S L; Teh, S J; Hinton, D E

    2000-01-01

    The US Geological Survey has reported the presence of a metal contamination gradient in clam tissues, decreased condition indices, and irregular reproductive patterns have been reported in the Asian clam, Potamocorbula amurensis, from San Francisco Bay. If metals are driving the observed patterns in the field, then biomarkers of exposure, and possibly deleterious effect, should show a corresponding gradient. In this study, biomarkers from sub-cellular to tissue levels of biological organization were assessed in P. amurensis collected from the Bay or exposed to cadmium in the laboratory. Cellular and tissue alterations were assessed using histopathology and enzyme histochemistry (EH). Alterations in the ovary, testis, kidney, and gill tissues were most common at the most contaminated station when data were averaged over a 12-month sampling period. EH analysis indicated decreased active transport, energy status, and glucose oxidation in kidney and digestive gland at the most contaminated site which may indicate a decreased potential for growth. Ovarian lesions observed in feral Asian clams were experimentally induced in healthy clams by cadmium exposure in laboratory exposures. Our results suggest a contaminant etiology for tissue alterations. PMID:11460709

  19. Alteration of cellular lipids and lipid metabolism markers in RTL-W1 cells exposed to model endocrine disrupters.

    PubMed

    Dimastrogiovanni, Giorgio; Córdoba, Marlon; Navarro, Isabel; Jáuregui, Olga; Porte, Cinta

    2015-08-01

    This work investigates the suitability of the rainbow trout liver cell line (RTL-W1) as an in-vitro model to study the ability of model endocrine disrupters, namely TBT, TPT, 4-NP, BPA and DEHP, to act as metabolic disrupters by altering cellular lipids and markers of lipid metabolism. Among the tested compounds, BPA and DEHP significantly increased the intracellular accumulation of triacylglycerols (TAGs), while all the compounds -apart from TPT-, altered membrane lipids - phosphatidylcholines (PCs) and plasmalogen PCs - indicating a strong interaction of the toxicants with cell membranes and cell signaling. RTL-W1 expressed a number of genes involved in lipid metabolism that were modulated by exposure to BPA, TBT and TPT (up-regulation of FATP1 and FAS) and 4-NP and DEHP (down-regulation of FAS and LPL). Multiple and complex modes of action of these chemicals were observed in RTL-W1 cells, both in terms of expression of genes related to lipid metabolism and alteration of cellular lipids. Although further characterization is needed, this might be a useful model for the detection of chemicals leading to steatosis or other diseases associated with lipid metabolism in fish. PMID:26143618

  20. Alterations in cellular differentiation, mitogenesis, cytoskeleton and growth characteristics during Syrian hamster embryo cell multistep in vitro transformation.

    PubMed

    Isfort, R J; Cody, D B; Doersen, C J; Kerckaert, G A; Leboeuf, R A

    1994-10-01

    In vitro Syrian hamster embryo (SHE) cell transformation is a neoplastic process that proceeds through several identifiable consecutive stages including in vitro morphological transformation (mt), acquisition of immortality (I+), acquisition of tumorigenicity (T+) and tumor-derived cells (I'TD). Eight transformed lineages consisting of cells at the mt, I+, T+ and I'TD stages were assayed for alterations in general markers of cell differentiation, mitogenic signaling pathways, cytoskeleton and cellular growth in 3D matrix. Alterations in cellular differentiation markers included a decrease in H19 gene expression and placental alkaline phosphatase enzymatic activity at the mt stage in all lineages examined with a complete absence of H19 gene expression and placental alkaline phosphatase enzymatic activity by the I'TD stage in a majority of transformed lineages. Changes in mitogenic signaling pathways included the production of autocrine growth factors and alterations in growth factor-induced immediate early gene expression by the I'TD stage of transformation in the majority of transformed lineages investigated. By the I'TD stage of transformation in most lineages, changes in both the cytoskeleton (including a decrease in tropomyosin-I gene expression) and the Matrigel growth characteristics of SHE cells were observed. PMID:7927892

  1. Methyl jasmonate deficiency alters cellular metabolome including the aminome of tomato (Solanum lycopersicum L.) fruit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lipoxygenase (LOX) catalyzes oxidation of C-13 atom of C:18 polyunsaturated fatty acids and produces jasmonic acid and other oxylipins that have important biological relevance. However, the role of these important molecules in cellular metabolism is barely understood. We have used a transgenic appro...

  2. Molecular design and nanoparticle-mediated intracellular delivery of functional proteins to target cellular pathways

    NASA Astrophysics Data System (ADS)

    Shah, Dhiral Ashwin

    Intracellular delivery of specific proteins and peptides represents a novel method to influence stem cells for gain-of-function and loss-of-function. Signaling control is vital in stem cells, wherein intricate control of and interplay among critical pathways directs the fate of these cells into either self-renewal or differentiation. The most common route to manipulate cellular function involves the introduction of genetic material such as full-length genes and shRNA into the cell to generate (or prevent formation of) the target protein, and thereby ultimately alter cell function. However, viral-mediated gene delivery may result in relatively slow expression of proteins and prevalence of oncogene insertion into the cell, which can alter cell function in an unpredictable fashion, and non-viral delivery may lead to low efficiency of genetic delivery. For example, the latter case plagues the generation of induced pluripotent stem cells (iPSCs) and hinders their use for in vivo applications. Alternatively, introducing proteins into cells that specifically recognize and influence target proteins, can result in immediate deactivation or activation of key signaling pathways within the cell. In this work, we demonstrate the cellular delivery of functional proteins attached to hydrophobically modified silica (SiNP) nanoparticles to manipulate specifically targeted cell signaling proteins. In the Wnt signaling pathway, we have targeted the phosphorylation activity of glycogen synthase kinase-3beta (GSK-3beta) by designing a chimeric protein and delivering it in neural stem cells. Confocal imaging indicates that the SiNP-chimeric protein conjugates were efficiently delivered to the cytosol of human embryonic kidney cells and rat neural stem cells, presumably via endocytosis. This uptake impacted the Wnt signaling cascade, indicated by the elevation of beta-catenin levels, and increased transcription of Wnt target genes, such as c-MYC. The results presented here suggest that

  3. Prenatal stress alters amygdala functional connectivity in preterm neonates.

    PubMed

    Scheinost, Dustin; Kwon, Soo Hyun; Lacadie, Cheryl; Sze, Gordon; Sinha, Rajita; Constable, R Todd; Ment, Laura R

    2016-01-01

    Exposure to prenatal and early-life stress results in alterations in neural connectivity and an increased risk for neuropsychiatric disorders. In particular, alterations in amygdala connectivity have emerged as a common effect across several recent studies. However, the impact of prenatal stress exposure on the functional organization of the amygdala has yet to be explored in the prematurely-born, a population at high risk for neuropsychiatric disorders. We test the hypothesis that preterm birth and prenatal exposure to maternal stress alter functional connectivity of the amygdala using two independent cohorts. The first cohort is used to establish the effects of preterm birth and consists of 12 very preterm neonates and 25 term controls, all without prenatal stress exposure. The second is analyzed to establish the effects of prenatal stress exposure and consists of 16 extremely preterm neonates with prenatal stress exposure and 10 extremely preterm neonates with no known prenatal stress exposure. Standard resting-state functional magnetic resonance imaging and seed connectivity methods are used. When compared to term controls, very preterm neonates show significantly reduced connectivity between the amygdala and the thalamus, the hypothalamus, the brainstem, and the insula (p < 0.05). Similarly, when compared to extremely preterm neonates without exposure to prenatal stress, extremely preterm neonates with exposure to prenatal stress show significantly less connectivity between the left amygdala and the thalamus, the hypothalamus, and the peristriate cortex (p < 0.05). Exploratory analysis of the combined cohorts suggests additive effects of prenatal stress on alterations in amygdala connectivity associated with preterm birth. Functional connectivity from the amygdala to other subcortical regions is decreased in preterm neonates compared to term controls. In addition, these data, for the first time, suggest that prenatal stress exposure amplifies these

  4. S-glutathionylation uncouples eNOS and regulates its cellular and vascular function

    PubMed Central

    Chen, Chun-An; Wang, Tse-Yao; Varadharaj, Saradhadevi; Reyes, Levy A.; Hemann, Craig; Hassan Talukder, M. A.; Chen, Yeong-Renn; Druhan, Lawrence J.; Zweier, Jay L.

    2012-01-01

    Endothelial nitric oxide synthase (eNOS) is critical in the regulation of vascular function, and can generate both nitric oxide (NO) and superoxide (O2•−), which are key mediators of cellular signalling. In the presence of Ca2+/calmodulin, eNOS produces NO, endothelial-derived relaxing factor, from L-arginine (L-Arg) by means of electron transfer from NADPH through a flavin containing reductase domain to oxygen bound at the haem of an oxygenase domain, which also contains binding sites for tetrahydrobiopterin (BH4) and L-Arg1–3. In the absence of BH4, NO synthesis is abrogated and instead O2•− is generated4–7. While NOS dysfunction occurs in diseases with redox stress, BH4 repletion only partly restores NOS activity and NOS-dependent vasodilation7. This suggests that there is an as yet unidentified redox-regulated mechanism controlling NOS function. Protein thiols can undergo S-glutathionylation, a reversible protein modification involved in cellular signalling and adaptation8,9. Under oxidative stress, S-glutathionylation occurs through thiol–disulphide exchange with oxidized glutathione or reaction of oxidant-induced protein thiyl radicals with reduced glutathione10,11. Cysteine residues are critical for the maintenance of eNOS function12,13; we therefore speculated that oxidative stress could alter eNOS activity through S-glutathionylation. Here we show that S-glutathionylation of eNOS reversibly decreases NOS activity with an increase in O2•− generation primarily from the reductase, in which two highly conserved cysteine residues are identified as sites of S-glutathionylation and found to be critical for redox-regulation of eNOS function. We show that eNOS S-glutathionylation in endothelial cells, with loss of NO and gain of O2•− generation, is associated with impaired endothelium-dependent vasodilation. In hypertensive vessels, eNOS S-glutathionylation is increased with impaired endothelium-dependent vasodilation that is restored by thiol

  5. Altered striatal intrinsic functional connectivity in pediatric anxiety.

    PubMed

    Dorfman, Julia; Benson, Brenda; Farber, Madeline; Pine, Daniel; Ernst, Monique

    2016-05-01

    Anxiety disorders are among the most common psychiatric disorders of adolescence. Behavioral and task-based imaging studies implicate altered reward system function, including striatal dysfunction, in adolescent anxiety. However, no study has yet examined alterations of the striatal intrinsic functional connectivity in adolescent anxiety disorders. The current study examines striatal intrinsic functional connectivity (iFC), using six bilateral striatal seeds, among 35 adolescents with anxiety disorders and 36 healthy comparisons. Anxiety is associated with abnormally low iFC within the striatum (e.g., between nucleus accumbens and caudate nucleus), and between the striatum and prefrontal regions, including subgenual anterior cingulate cortex, posterior insula and supplementary motor area. The current findings extend prior behavioral and task-based imaging research, and provide novel data implicating decreased striatal iFC in adolescent anxiety. Alterations of striatal neurocircuitry identified in this study may contribute to the perturbations in the processing of motivational, emotional, interoceptive, and motor information seen in pediatric anxiety disorders. This pattern of the striatal iFC perturbations can guide future research on specific mechanisms underlying anxiety. PMID:27004799

  6. A Distinct Role for Interleukin‐6 as a Major Mediator of Cellular Adjustment to an Altered Culture Condition

    PubMed Central

    Son, Hwa‐Kyung; Park, Iha; Kim, Jue Young; Kim, Do Kyeong; Illeperuma, Rasika P.; Bae, Jung Yoon; Lee, Doo Young; Oh, Eun‐Sang; Jung, Da‐Woon; Williams, Darren R.

    2015-01-01

    ABSTRACT Tissue microenvironment adjusts biological properties of different cells by modulating signaling pathways and cell to cell interactions. This study showed that epithelial–mesenchymal transition (EMT)/ mesenchymal–epithelial transition (MET) can be modulated by altering culture conditions. HPV E6/E7‐transfected immortalized oral keratinocytes (IHOK) cultured in different media displayed reversible EMT/MET accompanied by changes in cell phenotype, proliferation, gene expression at transcriptional, and translational level, and migratory and invasive activities. Cholera toxin, a major supplement to culture medium, was responsible for inducing the morphological and biological changes of IHOK. Cholera toxin per se induced EMT by triggering the secretion of interleukin 6 (IL‐6) from IHOK. We found IL‐6 to be a central molecule that modulates the reversibility of EMT based not only on the mRNA level but also on the level of secretion. Taken together, our results demonstrate that IL‐6, a cytokine whose transcription is activated by alterations in culture conditions, is a key molecule for regulating reversible EMT/MET. This study will contribute to understand one way of cellular adjustment for surviving in unfamiliar conditions. J. Cell. Biochem. 116: 2552–2562, 2015. © 2015 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc. PMID:25939389

  7. Fpk1/2 kinases regulate cellular sphingoid long-chain base abundance and alter cellular resistance to LCB elevation or depletion

    PubMed Central

    Yamane-Sando, Yukari; Shimobayashi, Etsuko; Shimobayashi, Mitsugu; Kozutsumi, Yasunori; Oka, Shogo; Takematsu, Hiromu

    2014-01-01

    Sphingolipids are a family of eukaryotic lipids biosynthesized from sphingoid long-chain bases (LCBs). Sphingolipids are an essential class of lipids, as their depletion results in cell death. However, acute LCB supplementation is also toxic; thus, proper cellular LCB levels should be maintained. To characterize the “sphingolipid-signaling intercross,” we performed a kinome screening assay in which budding yeast protein kinase-knockout strains were screened for resistance to ISP-1, a potent inhibitor of LCB biosynthesis. Here, one pair of such DIR (deletion-mediated ISP-1 resistance) genes, FPK1 and FPK2, was further characterized. Cellular LCB levels increased in the fpk1/2Δ strain, which was hypersensitive to phytosphingosine (PHS), a major LCB species of yeast cells. Concomitantly, this strain acquired resistance to ISP-1. Fpk1 and Fpk2 were involved in two downstream events; that is, ISP-1 uptake due to aminophospholipid flippase and LCB degradation due to LCB4 expression. RSK3, which belongs to the p90-S6K subfamily, was identified as a functional counterpart of Fpk1/2 in mammalian cells as the RSK3 gene functionally complemented the ISP-1-resistant phenotype of fpk1/2Δ cells. PMID:24510621

  8. Changes in gravity rapidly alter the magnitude and direction of a cellular calcium current.

    PubMed

    Salmi, Mari L; ul Haque, Aeraj; Bushart, Thomas J; Stout, Stephen C; Roux, Stanley J; Porterfield, D Marshall

    2011-05-01

    In single-celled spores of the fern Ceratopteris richardii, gravity directs polarity of development and induces a directional, trans-cellular calcium (Ca(2+)) current. To clarify how gravity polarizes this electrophysiological process, we measured the kinetics of the cellular response to changes in the gravity vector, which we initially estimated using the self-referencing calcium microsensor. In order to generate more precise and detailed data, we developed a silicon microfabricated sensor array which facilitated a lab-on-a-chip approach to simultaneously measure calcium currents from multiple cells in real time. These experiments revealed that the direction of the gravity-dependent polar calcium current is reversed in less than 25 s when the cells are inverted, and that changes in the magnitude of the calcium current parallel rapidly changing g-forces during parabolic flight on the NASA C-9 aircraft. The data also revealed a hysteresis in the response of cells in the transition from 2g to micro-g in comparison to cells in the micro-g to 2-g transition, a result consistent with a role for mechanosensitive ion channels in the gravity response. The calcium current is suppressed by either nifedipine (calcium-channel blocker) or eosin yellow (plasma membrane calcium pump inhibitor). Nifedipine disrupts gravity-directed cell polarity, but not spore germination. These results indicate that gravity perception in single plant cells may be mediated by mechanosensitive calcium channels, an idea consistent with some previously proposed models of plant gravity perception. PMID:21234599

  9. Pathophysiology of Corneal Dystrophies: From Cellular Genetic Alteration to Clinical Findings.

    PubMed

    Sacchetti, Marta; Macchi, Ilaria; Tiezzi, Alessandro; La Cava, Maurizio; Massaro-Giordano, Giacomina; Lambiase, Alessandro

    2016-02-01

    Corneal dystrophies are a heterogeneous group of bilateral, inherited, rare diseases characterized by slowly progressive corneal opacities, that lead to visual impairment. Most of them have an autosomal dominant pattern of inheritance with variable expressivity, but new mutations have been described. Many corneal dystrophies have been genetically characterized and the specific gene mutations identified, such as for the epithelial-stromal TGFBI dystrophies. Current classification systems identified four main groups of corneal dystrophies based on clinical, histologic, and genetic information. Diagnosis is performed during a routine ophthalmic examination that shows typical cellular abnormalities of the corneal epithelium, stroma, or endothelium. Disease progression should be carefully monitored to decide the proper clinical management. The treatment of corneal dystrophies is variable, depending on symptoms, clinical course, severity, and type of dystrophy. Management aimed to reduce symptoms and to improve vision, includes different surgical approaches. Novel cellular and genetic therapeutic approaches are under evaluation. J. Cell. Physiol. 231: 261-269, 2016. © 2015 Wiley Periodicals, Inc. PMID:26104822

  10. JC virus induces altered patterns of cellular gene expression: Interferon-inducible genes as major transcriptional targets

    SciTech Connect

    Verma, Saguna; Ziegler, Katja; Ananthula, Praveen; Co, Juliene K.G.; Frisque, Richard J.; Yanagihara, Richard; Nerurkar, Vivek R. . E-mail: nerurkar@pbrc.hawaii.edu

    2006-02-20

    Human polyomavirus JC (JCV) infects 80% of the population worldwide. Primary infection, typically occurring during childhood, is asymptomatic in immunocompetent individuals and results in lifelong latency and persistent infection. However, among the severely immunocompromised, JCV may cause a fatal demyelinating disease, progressive multifocal leukoencephalopathy (PML). Virus-host interactions influencing persistence and pathogenicity are not well understood, although significant regulation of JCV activity is thought to occur at the level of transcription. Regulation of the JCV early and late promoters during the lytic cycle is a complex event that requires participation of both viral and cellular factors. We have used cDNA microarray technology to analyze global alterations in gene expression in JCV-permissive primary human fetal glial cells (PHFG). Expression of more than 400 cellular genes was altered, including many that influence cell proliferation, cell communication and interferon (IFN)-mediated host defense responses. Genes in the latter category included signal transducer and activator of transcription 1 (STAT1), interferon stimulating gene 56 (ISG56), myxovirus resistance 1 (MxA), 2'5'-oligoadenylate synthetase (OAS), and cig5. The expression of these genes was further confirmed in JCV-infected PHFG cells and the human glioblastoma cell line U87MG to ensure the specificity of JCV in inducing this strong antiviral response. Results obtained by real-time RT-PCR and Western blot analyses supported the microarray data and provide temporal information related to virus-induced changes in the IFN response pathway. Our data indicate that the induction of an antiviral response may be one of the cellular factors regulating/controlling JCV replication in immunocompetent hosts and therefore constraining the development of PML.

  11. 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. PMID:24901212

  12. 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

  13. Limb immobilization alters functional electrophysiological parameters of sciatic nerve.

    PubMed

    Alves, J S M; Leal-Cardoso, J H; Santos-Júnior, F F U; Carlos, P S; Silva, R C; Lucci, C M; Báo, S N; Ceccatto, V M; Barbosa, R

    2013-08-01

    Immobilization, used in clinical practice to treat traumatologic problems, causes changes in muscle, but it is not known whether changes also occur in nerves. We investigated the effects of immobilization on excitability and compound action potential (CAP) and the ultrastructure of the rat sciatic nerve. Fourteen days after immobilization of the right leg of adult male Wistar rats (n=34), animals were killed and the right sciatic nerve was dissected and mounted in a moist chamber. Nerves were stimulated at a baseline frequency of 0.2 Hz and tested for 2 min at 20, 50, and 100 Hz. Immobilization altered nerve excitability. Rheobase and chronaxy changed from 3.13 ± 0.05 V and 52.31 ± 1.95 µs (control group, n=13) to 2.84 ± 0.06 V and 59.71 ± 2.79 µs (immobilized group, n=15), respectively. Immobilization altered the amplitude of CAP waves and decreased the conduction velocity of the first CAP wave (from 93.63 ± 7.49 to 79.14 ± 5.59 m/s) but not of the second wave. Transmission electron microscopy showed fragmentation of the myelin sheath of the sciatic nerve of immobilized limbs and degeneration of the axon. In conclusion, we demonstrated that long-lasting leg immobilization can induce alterations in nerve function. PMID:23969978

  14. Limb immobilization alters functional electrophysiological parameters of sciatic nerve

    PubMed Central

    Alves, J.S.M.; Leal-Cardoso, J.H.; Santos-Júnior, F.F.U.; Carlos, P.S.; Silva, R.C.; Lucci, C.M.; Báo, S.N.; Ceccatto, V.M.; Barbosa, R.

    2013-01-01

    Immobilization, used in clinical practice to treat traumatologic problems, causes changes in muscle, but it is not known whether changes also occur in nerves. We investigated the effects of immobilization on excitability and compound action potential (CAP) and the ultrastructure of the rat sciatic nerve. Fourteen days after immobilization of the right leg of adult male Wistar rats (n=34), animals were killed and the right sciatic nerve was dissected and mounted in a moist chamber. Nerves were stimulated at a baseline frequency of 0.2 Hz and tested for 2 min at 20, 50, and 100 Hz. Immobilization altered nerve excitability. Rheobase and chronaxy changed from 3.13±0.05 V and 52.31±1.95 µs (control group, n=13) to 2.84±0.06 V and 59.71±2.79 µs (immobilized group, n=15), respectively. Immobilization altered the amplitude of CAP waves and decreased the conduction velocity of the first CAP wave (from 93.63±7.49 to 79.14±5.59 m/s) but not of the second wave. Transmission electron microscopy showed fragmentation of the myelin sheath of the sciatic nerve of immobilized limbs and degeneration of the axon. In conclusion, we demonstrated that long-lasting leg immobilization can induce alterations in nerve function. PMID:23969978

  15. FLI1 expression is correlated with breast cancer cellular growth, migration, and invasion and altered gene expression.

    PubMed

    Scheiber, Melissa N; Watson, Patricia M; Rumboldt, Tihana; Stanley, Connor; Wilson, Robert C; Findlay, Victoria J; Anderson, Paul E; Watson, Dennis K

    2014-10-01

    ETS factors have been shown to be dysregulated in breast cancer. ETS factors control the expression of genes involved in many biological processes, such as cellular proliferation, differentiation, and apoptosis. FLI1 is an ETS protein aberrantly expressed in retrovirus-induced hematological tumors, but limited attention has been directed towards elucidating the role of FLI1 in epithelial-derived cancers. Using data mining, we show that loss of FLI1 expression is associated with shorter survival and more aggressive phenotypes of breast cancer. Gain and loss of function cellular studies indicate the inhibitory effect of FLI1 expression on cellular growth, migration, and invasion. Using Fli1 mutant mice and both a transgenic murine breast cancer model and an orthotopic injection of syngeneic tumor cells indicates that reduced Fli1 contributes to accelerated tumor growth. Global expression analysis and RNA-Seq data from an invasive human breast cancer cell line with over expression of either FLI1 and another ETS gene, PDEF, shows changes in several cellular pathways associated with cancer, such as the cytokine-cytokine receptor interaction and PI3K-Akt signaling pathways. This study demonstrates a novel role for FLI1 in epithelial cells. In addition, these results reveal that FLI1 down-regulation in breast cancer may promote tumor progression. PMID:25379017

  16. FLI1 Expression is Correlated with Breast Cancer Cellular Growth, Migration, and Invasion and Altered Gene Expression

    PubMed Central

    Scheiber, Melissa N.; Watson, Patricia M.; Rumboldt, Tihana; Stanley, Connor; Wilson, Robert C.; Findlay, Victoria J.; Anderson, Paul E.; Watson, Dennis K.

    2014-01-01

    ETS factors have been shown to be dysregulated in breast cancer. ETS factors control the expression of genes involved in many biological processes, such as cellular proliferation, differentiation, and apoptosis. FLI1 is an ETS protein aberrantly expressed in retrovirus-induced hematological tumors, but limited attention has been directed towards elucidating the role of FLI1 in epithelial-derived cancers. Using data mining, we show that loss of FLI1 expression is associated with shorter survival and more aggressive phenotypes of breast cancer. Gain and loss of function cellular studies indicate the inhibitory effect of FLI1 expression on cellular growth, migration, and invasion. Using Fli1 mutant mice and both a transgenic murine breast cancer model and an orthotopic injection of syngeneic tumor cells indicates that reduced Fli1 contributes to accelerated tumor growth. Global expression analysis and RNA-Seq data from an invasive human breast cancer cell line with over expression of either FLI1 and another ETS gene, PDEF, shows changes in several cellular pathways associated with cancer, such as the cytokine-cytokine receptor interaction and PI3K-Akt signaling pathways. This study demonstrates a novel role for FLI1 in epithelial cells. In addition, these results reveal that FLI1 down-regulation in breast cancer may promote tumor progression. PMID:25379017

  17. Cellular MYCro Economics: Balancing MYC Function with MYC Expression

    PubMed Central

    Levens, David

    2013-01-01

    The expression levels of the MYC oncoprotein have long been recognized to be associated with the outputs of major cellular processes including proliferation, cell growth, apoptosis, differentiation, and metabolism. Therefore, to understand how MYC operates, it is important to define quantitatively the relationship between MYC input and expression output for its targets as well as the higher-order relationships between the expression levels of subnetwork components and the flow of information and materials through those networks. Two different views of MYC are considered, first as a molecular microeconomic manager orchestrating specific positive and negative responses at individual promoters in collaboration with other transcription and chromatin components, and second, as a macroeconomic czar imposing an overarching rule onto all active genes. In either case, c-myc promoter output requires multiple inputs and exploits diverse mechanisms to tune expression to the appropriate levels relative to the thresholds of expression that separate health and disease. PMID:24186489

  18. Photothermal cellular stimulation in functional bio-polymer interfaces.

    PubMed

    Martino, Nicola; Feyen, Paul; Porro, Matteo; Bossio, Caterina; Zucchetti, Elena; Ghezzi, Diego; Benfenati, Fabio; Lanzani, Guglielmo; Antognazza, Maria Rosa

    2015-01-01

    Hybrid interfaces between organic semiconductors and living tissues represent a new tool for in-vitro and in-vivo applications, bearing a huge potential, from basic researches to clinical applications. In particular, light sensitive conjugated polymers can be exploited as a new approach for optical modulation of cellular activity. In this work we focus on light-induced changes in the membrane potential of Human Embryonic Kidney (HEK-293) cells grown on top of a poly(3-hexylthiophene) (P3HT) thin film. On top of a capacitive charging of the polymer interface, we identify and fully characterize two concomitant mechanisms, leading to membrane depolarization and hyperpolarisation, both mediated by a thermal effect. Our results can be usefully exploited in the creation of a new platform for light-controlled cell manipulation, with possible applications in neuroscience and medicine. PMID:25753132

  19. Photothermal cellular stimulation in functional bio-polymer interfaces

    PubMed Central

    Martino, Nicola; Feyen, Paul; Porro, Matteo; Bossio, Caterina; Zucchetti, Elena; Ghezzi, Diego; Benfenati, Fabio; Lanzani, Guglielmo; Antognazza, Maria Rosa

    2015-01-01

    Hybrid interfaces between organic semiconductors and living tissues represent a new tool for in-vitro and in-vivo applications, bearing a huge potential, from basic researches to clinical applications. In particular, light sensitive conjugated polymers can be exploited as a new approach for optical modulation of cellular activity. In this work we focus on light-induced changes in the membrane potential of Human Embryonic Kidney (HEK-293) cells grown on top of a poly(3-hexylthiophene) (P3HT) thin film. On top of a capacitive charging of the polymer interface, we identify and fully characterize two concomitant mechanisms, leading to membrane depolarization and hyperpolarisation, both mediated by a thermal effect. Our results can be usefully exploited in the creation of a new platform for light-controlled cell manipulation, with possible applications in neuroscience and medicine. PMID:25753132

  20. Deletion or Overexpression of Mitochondrial NAD+ Carriers in Saccharomyces cerevisiae Alters Cellular NAD and ATP Contents and Affects Mitochondrial Metabolism and the Rate of Glycolysis ▿

    PubMed Central

    Agrimi, Gennaro; Brambilla, Luca; Frascotti, Gianni; Pisano, Isabella; Porro, Danilo; Vai, Marina; Palmieri, Luigi

    2011-01-01

    The modification of enzyme cofactor concentrations can be used as a method for both studying and engineering metabolism. We varied Saccharomyces cerevisiae mitochondrial NAD levels by altering expression of its specific mitochondrial carriers. Changes in mitochondrial NAD levels affected the overall cellular concentration of this coenzyme and the cellular metabolism. In batch culture, a strain with a severe NAD depletion in mitochondria succeeded in growing, albeit at a low rate, on fully respiratory media. Although the strain increased the efficiency of its oxidative phosphorylation, the ATP concentration was low. Under the same growth conditions, a strain with a mitochondrial NAD concentration higher than that of the wild type similarly displayed a low cellular ATP level, but its growth rate was not affected. In chemostat cultures, when cellular metabolism was fully respiratory, both mutants showed low biomass yields, indicative of impaired energetic efficiency. The two mutants increased their glycolytic fluxes, and as a consequence, the Crabtree effect was triggered at lower dilution rates. Strikingly, the mutants switched from a fully respiratory metabolism to a respirofermentative one at the same specific glucose flux as that of the wild type. This result seems to indicate that the specific glucose uptake rate and/or glycolytic flux should be considered one of the most important independent variables for establishing the long-term Crabtree effect. In cells growing under oxidative conditions, bioenergetic efficiency was affected by both low and high mitochondrial NAD availability, which suggests the existence of a critical mitochondrial NAD concentration in order to achieve optimal mitochondrial functionality. PMID:21335394

  1. Connectomics and neuroticism: an altered functional network organization.

    PubMed

    Servaas, Michelle N; Geerligs, Linda; Renken, Remco J; Marsman, Jan-Bernard C; Ormel, Johan; Riese, Harriëtte; Aleman, André

    2015-01-01

    The personality trait neuroticism is a potent risk marker for psychopathology. Although the neurobiological basis remains unclear, studies have suggested that alterations in connectivity may underlie it. Therefore, the aim of the current study was to shed more light on the functional network organization in neuroticism. To this end, we applied graph theory on resting-state functional magnetic resonance imaging (fMRI) data in 120 women selected based on their neuroticism score. Binary and weighted brain-wide graphs were constructed to examine changes in the functional network structure and functional connectivity strength. Furthermore, graphs were partitioned into modules to specifically investigate connectivity within and between functional subnetworks related to emotion processing and cognitive control. Subsequently, complex network measures (ie, efficiency and modularity) were calculated on the brain-wide graphs and modules, and correlated with neuroticism scores. Compared with low neurotic individuals, high neurotic individuals exhibited a whole-brain network structure resembling more that of a random network and had overall weaker functional connections. Furthermore, in these high neurotic individuals, functional subnetworks could be delineated less clearly and the majority of these subnetworks showed lower efficiency, while the affective subnetwork showed higher efficiency. In addition, the cingulo-operculum subnetwork demonstrated more ties with other functional subnetworks in association with neuroticism. In conclusion, the 'neurotic brain' has a less than optimal functional network organization and shows signs of functional disconnectivity. Moreover, in high compared with low neurotic individuals, emotion and salience subnetworks have a more prominent role in the information exchange, while sensory(-motor) and cognitive control subnetworks have a less prominent role. PMID:25005250

  2. Connectomics and Neuroticism: An Altered Functional Network Organization

    PubMed Central

    Servaas, Michelle N; Geerligs, Linda; Renken, Remco J; Marsman, Jan-Bernard C; Ormel, Johan; Riese, Harriëtte; Aleman, André

    2015-01-01

    The personality trait neuroticism is a potent risk marker for psychopathology. Although the neurobiological basis remains unclear, studies have suggested that alterations in connectivity may underlie it. Therefore, the aim of the current study was to shed more light on the functional network organization in neuroticism. To this end, we applied graph theory on resting-state functional magnetic resonance imaging (fMRI) data in 120 women selected based on their neuroticism score. Binary and weighted brain-wide graphs were constructed to examine changes in the functional network structure and functional connectivity strength. Furthermore, graphs were partitioned into modules to specifically investigate connectivity within and between functional subnetworks related to emotion processing and cognitive control. Subsequently, complex network measures (ie, efficiency and modularity) were calculated on the brain-wide graphs and modules, and correlated with neuroticism scores. Compared with low neurotic individuals, high neurotic individuals exhibited a whole-brain network structure resembling more that of a random network and had overall weaker functional connections. Furthermore, in these high neurotic individuals, functional subnetworks could be delineated less clearly and the majority of these subnetworks showed lower efficiency, while the affective subnetwork showed higher efficiency. In addition, the cingulo-operculum subnetwork demonstrated more ties with other functional subnetworks in association with neuroticism. In conclusion, the ‘neurotic brain' has a less than optimal functional network organization and shows signs of functional disconnectivity. Moreover, in high compared with low neurotic individuals, emotion and salience subnetworks have a more prominent role in the information exchange, while sensory(-motor) and cognitive control subnetworks have a less prominent role. PMID:25005250

  3. CG hypomethylation in Lsh−/− mouse embryonic fibroblasts is associated with de novo H3K4me1 formation and altered cellular plasticity

    PubMed Central

    Yu, Weishi; Briones, Victorino; Lister, Ryan; McIntosh, Carl; Han, Yixing; Lee, Eunice Y.; Ren, Jianke; Terashima, Minoru; Leighty, Robert M.; Ecker, Joseph R.; Muegge, Kathrin

    2014-01-01

    DNA methylation patterns are established in early embryogenesis and are critical for cellular differentiation. To investigate the role of CG methylation in potential enhancer formation, we assessed H3K4me1 modification in murine embryonic fibroblasts (MEFs) derived from the DNA methylation mutant Lsh−/− mice. We report here de novo formation of putative enhancer elements at CG hypomethylated sites that can be dynamically altered. We found a subset of differentially enriched H3K4me1 regions clustered at neuronal lineage genes and overlapping with known cis-regulatory elements present in brain tissue. Reprogramming of Lsh−/− MEFs into induced pluripotent stem (iPS) cells leads to increased neuronal lineage gene expression of premarked genes and enhanced differentiation potential of Lsh−/− iPS cells toward the neuronal lineage pathway compared with WT iPS cells in vitro and in vivo. The state of CG hypomethylation and H3K4me1 enrichment is partially maintained in Lsh−/− iPS cells. The acquisition of H3K27ac and activity of subcloned fragments in an enhancer reporter assay indicate functional activity of several of de novo H3K4me1-marked sequences. Our results suggest a functional link of H3K4me1 enrichment at CG hypomethylated sites, enhancer formation, and cellular plasticity. PMID:24711395

  4. Cellular and molecular alterations in human epithelial cells transformed by high let radiation

    NASA Astrophysics Data System (ADS)

    Hei, T. K.; Piao, C. Q.; Sutter, T.; Willey, J. C.; Suzuki, K.

    An understanding of the radiobiological effects of high LET radiation is essential for human risk estimation and radiation protection. In the present study, we show that a single, 30 cGy dose of 150 keV/mum ^4He ions can malignantly transform human papillomavirus immortalized human bronchial epithelial [BEP2D] cells. Transformed cells produce progressively growing tumors in nude mice. The transformation frequency by the single dose of alpha particles is estimated to be approximately 4 x 10^-7. Based on the average cross-sectional area of BEP2D cells, it can be calculated that a mean traversal of 1.4 particles per cell is sufficient to induce tumorigenic conversion of these cells 3 to 4 months post-irradiation. Tumorigenic BEP2D cells overexpress mutated p53 tumor suppressor oncoproteins in addition to the cell cycle control gene cyclin D1 and D2. This model provides an opportunity to study the cellular and molecular changes at the various stages in radiation carcinogenesis involving human cells.

  5. EDTA treatment alters protein glycosylation in the cellular slime mold Dictyostelium discoideum

    SciTech Connect

    West, C.M.; Brownstein, S.A. )

    1988-03-01

    The authors have found that treatment of cells with EDTA resulted in the accumulation of lower molecular weight forms of two cell-type-specific glycoproteins. These new glycoproteins lacked a developmentally regulated glycoantigen defined by monoclonal antibody 54.2. Since EDTA dissociated the cells, the possible involvement of cell separation was tested by immobilizing cells in soft agarose. Glycoantigen expression on these proteins was found to be dependent on cAMP and high oxygen tension but not on cell contact, and was reversibly sensitive to EDTA regardless of the state of cell association. The EDTA effect was mimicked by other soluble, but not particulate, membrane impermeable chelators, could be completed by Zn{sup 2+} better than Mg{sup 2+}, and appeared to involve an intracellular mechanism. Studies with ({sup 14}C)EDTA showed that EDTA equilibrated with a cellular compartment in a temperature-dependent, Zn{sup 2+}-insensitive fashion with half-time kinetics of loading and unloading of 30-40 min. The data suggest that this step in glycosylation, which was found to be delayed 1 or more hours subsequent to protein synthesis, involves an intracellular, transition metal-ion-dependent process which can be modulated by chelators entering the cell through the endocytic pathway.

  6. Altered Skeletal Muscle Mitochondrial Proteome As the Basis of Disruption of Mitochondrial Function in Diabetic Mice.

    PubMed

    Zabielski, Piotr; Lanza, Ian R; Gopala, Srinivas; Heppelmann, Carrie J Holtz; Bergen, H Robert; Dasari, Surendra; Nair, K Sreekumaran

    2016-03-01

    Insulin plays pivotal role in cellular fuel metabolism in skeletal muscle. Despite being the primary site of energy metabolism, the underlying mechanism on how insulin deficiency deranges skeletal muscle mitochondrial physiology remains to be fully understood. Here we report an important link between altered skeletal muscle proteome homeostasis and mitochondrial physiology during insulin deficiency. Deprivation of insulin in streptozotocin-induced diabetic mice decreased mitochondrial ATP production, reduced coupling and phosphorylation efficiency, and increased oxidant emission in skeletal muscle. Proteomic survey revealed that the mitochondrial derangements during insulin deficiency were related to increased mitochondrial protein degradation and decreased protein synthesis, resulting in reduced abundance of proteins involved in mitochondrial respiration and β-oxidation. However, a paradoxical upregulation of proteins involved in cellular uptake of fatty acids triggered an accumulation of incomplete fatty acid oxidation products in skeletal muscle. These data implicate a mismatch of β-oxidation and fatty acid uptake as a mechanism leading to increased oxidative stress in diabetes. This notion was supported by elevated oxidative stress in cultured myotubes exposed to palmitate in the presence of a β-oxidation inhibitor. Together, these results indicate that insulin deficiency alters the balance of proteins involved in fatty acid transport and oxidation in skeletal muscle, leading to impaired mitochondrial function and increased oxidative stress. PMID:26718503

  7. Investigation of cadmium-induced alterations in renal glomerular function

    SciTech Connect

    Long, T.J.

    1982-01-01

    This research was designed to test the hypothesis that certain aspects of cadmium-induced renal dysfunction are the result of glomerular, rather than classic tubular, injury. To determine whether cadmium-induced proteinuria was due to altered glomerular function, cadmium was administered chronically at a concentration of 185 ppm in the drinking water. This protocol resulted in the production of proteinuria which when analyzed by high pressure liquid chromatography and radioimmunoassay was indistinguishable from that occurring in control rats. Glomerular filtration rate, renal blood flow, and filtration fraction were all significantly depressed after 20-30 weeks of exposure. In order to further investigate these alterations in glomerular function, an acute exposure model was developed. It was found that a single i.p. injection of cadmium in mercaptoethanol resulted in the onset of acute renal failure. The clinical picture was characterized by a reduction in glomerular filtrate rate of 50-90% within 24 hours, with partial to total recovery occurring by day 7 post-exposure. Histological evidence indicated that to a large extent the reduction in GFR was due to tubular blockade and/or backleak of filtrate across damaged tubules.

  8. Altered Cardiomyocyte Function and Trypanosoma cruzi Persistence in Chagas Disease.

    PubMed

    Cruz, Jader Santos; Santos-Miranda, Artur; Sales-Junior, Policarpo Ademar; Monti-Rocha, Renata; Campos, Paula Peixoto; Machado, Fabiana Simão; Roman-Campos, Danilo

    2016-05-01

    Chagas disease, caused by the triatominae Trypanosoma cruzi, is one of the leading causes of heart malfunctioning in Latin America. The cardiac phenotype is observed in 20-30% of infected people 10-40 years after their primary infection. The cardiac complications during Chagas disease range from cardiac arrhythmias to heart failure, with important involvement of the right ventricle. Interestingly, no studies have evaluated the electrical properties of right ventricle myocytes during Chagas disease and correlated them to parasite persistence. Taking advantage of a murine model of Chagas disease, we studied the histological and electrical properties of right ventricle in acute (30 days postinfection [dpi]) and chronic phases (90 dpi) of infected mice with the Colombian strain of T. cruzi and their correlation to parasite persistence. We observed an increase in collagen deposition and inflammatory infiltrate at both 30 and 90 dpi. Furthermore, using reverse transcriptase polymerase chain reaction, we detected parasites at 90 dpi in right and left ventricles. In addition, we observed action potential prolongation and reduced transient outward K(+) current and L-type Ca(2+) current at 30 and 90 dpi. Taking together, our results demonstrate that T. cruzi infection leads to important modifications in electrical properties associated with inflammatory infiltrate and parasite persistence in mice right ventricle, suggesting a causal role between inflammation, parasite persistence, and altered cardiomyocyte function in Chagas disease. Thus, arrhythmias observed in Chagas disease may be partially related to altered electrical function in right ventricle. PMID:26976879

  9. Selective alterations within executive functions in adolescents with excess weight.

    PubMed

    Verdejo-García, Antonio; Pérez-Expósito, Manuel; Schmidt-Río-Valle, Jacqueline; Fernández-Serrano, Maria J; Cruz, Francisco; Pérez-García, Miguel; López-Belmonte, Gemma; Martín-Matillas, Miguel; Martín-Lagos, Jose A; Marcos, Ascension; Campoy, Cristina

    2010-08-01

    Increasing evidence underscores overlapping neurobiological pathways to addiction and obesity. In both conditions, reward processing of preferred stimuli is enhanced, whereas the executive control system that would normally regulate reward-driven responses is altered. This abnormal interaction can be greater in adolescence, a period characterized by relative immaturity of executive control systems coupled with the relative maturity of reward processing systems. The aim of this study is to explore neuropsychological performance of adolescents with excess weight (n = 27, BMI range 24-51 kg/m(2)) vs. normal-weight adolescents (n = 34, BMI range 17-24 kg/m(2)) on a comprehensive battery of executive functioning tests, including measures of working memory (letter-number sequencing), reasoning (similarities), planning (zoo map), response inhibition (five-digit test (FDT)-interference and Stroop), flexibility (FDT-switching and trail-making test (TMT)), self-regulation (revised-strategy application test (R-SAT)), and decision-making (Iowa gambling task (IGT)). We also aimed to explore personality traits of impulsivity and sensitivity to reward. Independent sample t- and Z Kolmogorov-Smirnov tests showed significant differences between groups on indexes of inhibition, flexibility, and decision-making (excess-weight participants performed poorer than controls), but not on tests of working memory, planning, and reasoning, nor on personality measures. Moreover, regression models showed a significant association between BMI and flexibility performance. These results are indicative of selective alterations of particular components of executive functions in overweight adolescents. PMID:20057376

  10. Cellular Trafficking of Phospholamban and Formation of Functional Sarcoplasmic Reticulum During Myocyte DIfferentiation

    SciTech Connect

    Stenoien, David L.; Knyushko, Tatyana V.; Londono, Monica P.; Opresko, Lee; Mayer, M. Uljana; Brady, Scott T.; Squier, Thomas C.; Bigelow, Diana J.

    2007-06-01

    The sarco/endoplasmic reticulum Ca-ATPase (SERCA) family members are transmembrane proteins that play an essential role in regulating intracellular calcium levels. Phospholamban (PLB), a 52 amino acid phosphoprotein, regulates SERCA activity in adult heart and skeletal muscle. Using the C2C12 myocyte cell line, we find endogenous PLB constitutively expressed in both myoblasts and myotubes, whereas SERCA expression coincides with activation of the differentiation program. PLB has a punctuate distribution in myoblasts changing to a reticular distribution in myotubes where it colocalizes with SERCAs. To examine the distribution and dynamics of PLB and SERCA, we expressed fluorescent fusion proteins (GFP, CFP, and YFP) of PLB and SERCA in myoblasts. Coexpressed PLB and SERCA localize to distinct cellular compartments in myoblasts but begin to colocalize as cells differentiate. Fluorescence Recovery After Photobleaching (FRAP) studies show different recovery patterns for each protein in myoblasts confirming their localization to distinct compartments. To extend these studies, we created stable cell lines expressing O6-alkylguanine-DNA alkyltransferase (AGT) fusions with PLB or SERCA to track their localization as myocytes differentiate. These experiments demonstrate that PLB localizes to punctate vesicles in myoblasts and adopts a reticular distribution that coincides with SERCA distribution after differentiation. Colocalization experiments indicate that a subset of PLB in myoblasts colocalizes with endosomes, Golgi, and the plasma membrane however PLB also localizes to other, as yet unidentified vesicles. Our results indicate that differentiation plays a critical role in regulating PLB distribution to ensure its colocalization within the same cellular compartment as SERCA in differentiated cells. The presence and altered distribution of PLB in undifferentiated myoblasts raises the possibility that this protein has additional functions distinct from SERCA regulation.

  11. Ethanol alters cellular activation and CD14 partitioning in lipid rafts

    SciTech Connect

    Dai Qun; Zhang Jun; Pruett, Stephen B. . E-mail: spruet@lsuhsc.edu

    2005-06-24

    Alcohol consumption interferes with innate immunity. In vivo EtOH administration suppresses cytokine responses induced through Toll-like receptor 4 (TLR4) and inhibits TLR4 signaling. Actually, EtOH exhibits a generalized suppressive effect on signaling and cytokine responses induced by through most TLRs. However, the underlying mechanism remains unknown. RAW264.7 cells were treated with LPS or co-treated with EtOH or with lipid raft-disrupting drugs. TNF-{alpha} production, IRAK-1 activation, and CD14 partition were evaluated. EtOH or nystatin, a lipid raft-disrupting drug, suppressed LPS-induced production of TNF-{alpha}. The suppressive effect of EtOH on LPS-induced TNF-{alpha} production was additive with that of methyl-{beta}-cyclodextrin (MCD), another lipid raft-disrupting drug. EtOH interfered with IRAK-1 activation, an early TLR4 intracellular signaling event. Cell fractionation analyses show that acute EtOH altered LPS-related partition of CD14, a critical component of the LPS receptor complex. These results suggest a novel mechanism of EtOH action that involves interference with lipid raft clustering induced by LPS. This membrane action of EtOH might be one of the mechanisms by which EtOH acts as a generalized suppressor for TLR signaling.

  12. Alterations in cellular metabolome after pharmacological inhibition of Notch in glioblastoma cells.

    PubMed

    Kahlert, Ulf D; Cheng, Menglin; Koch, Katharina; Marchionni, Luigi; Fan, Xing; Raabe, Eric H; Maciaczyk, Jarek; Glunde, Kristine; Eberhart, Charles G

    2016-03-01

    Notch signaling can promote tumorigenesis in the nervous system and plays important roles in stem-like cancer cells. However, little is known about how Notch inhibition might alter tumor metabolism, particularly in lesions arising in the brain. The gamma-secretase inhibitor MRK003 was used to treat glioblastoma neurospheres, and they were subdivided into sensitive and insensitive groups in terms of canonical Notch target response. Global metabolomes were then examined using proton magnetic resonance spectroscopy, and changes in intracellular concentration of various metabolites identified which correlate with Notch inhibition. Reductions in glutamate were verified by oxidation-based colorimetric assays. Interestingly, the alkylating chemotherapeutic agent temozolomide, the mTOR-inhibitor MLN0128, and the WNT inhibitor LGK974 did not reduce glutamate levels, suggesting that changes to this metabolite might reflect specific downstream effects of Notch blockade in gliomas rather than general sequelae of tumor growth inhibition. Global and targeted expression analyses revealed that multiple genes important in glutamate homeostasis, including glutaminase, are dysregulated after Notch inhibition. Treatment with an allosteric inhibitor of glutaminase, compound 968, could slow glioblastoma growth, and Notch inhibition may act at least in part by regulating glutaminase and glutamate. PMID:26422827

  13. Alterations in cellular metabolome after pharmacological inhibition of Notch in glioblastoma cells

    PubMed Central

    Kahlert, Ulf D.; Cheng, Menglin; Koch, Katharina; Marchionni, Luigi; Fan, Xing; Raabe, Eric H.; Maciaczyk, Jarek; Glunde, Kristine; Eberhart, Charles G.

    2016-01-01

    Notch signaling can promote tumorigenesis in the nervous system and plays important roles in stem-like cancer cells. However, little is known about how Notch inhibition might alter tumor metabolism, particularly in lesions arising in the brain. The gamma-secretase inhibitor MRK003 was used to treat glioblastoma neurospheres, and they were subdivided into sensitive and insensitive groups in terms of canonical Notch target response. Global metabolomes were then examined using proton magnetic resonance spectroscopy, and changes in intracellular concentration of various metabolites identified which correlate with Notch inhibition. Reductions in glutamate were verified by oxidation-based colorimetric assays. Interestingly, the alkylating chemotherapeutic agent temozolomide, the mTOR-inhibitor MLN0128, and the WNT inhibitor LGK974 did not reduce glutamate levels, suggesting that changes to this metabolite might reflect specific downstream effects of Notch blockade in gliomas rather than general sequelae of tumor growth inhibition. Global and targeted expression analyses revealed that multiple genes important in glutamate homeostasis, including glutaminase, are dysregulated after Notch inhibition. Treatment with an allosteric inhibitor of glutaminase, compound 968, could slow glioblastoma growth, and Notch inhibition may act at least in part by regulating glutaminase and glutamate. PMID:26422827

  14. Cellular proliferation and infiltration following interstitial irradiation of normal dog brain is altered by an inhibitor of polyamine synthesis

    SciTech Connect

    Fike, J.R.; Gobbel, G.T.; Chou, D.

    1995-07-15

    The objectives of this study were to quantitatively define proliferative and infiltrative cell responses after focal {sup 125}I irradiation of normal brain, and to determine the effects of an intravenous infusion of {alpha}-defluoromethylornithine (DFMO) on those responses. Adult beagle dogs were irradiated using high activity {sup 125}I sources. Cellular responses were quantified using a histomorphometric analysis. After radiation alone, cellular events included a substantial acute inflammatory response followed by increased BrdU labeling and progressive increases in numbers of capillaries and astrocytes. {alpha}-Difluoromethylornithine treatment significantly affected the measured cell responses. As in controls, an early inflammatory response was measured, but after 2 weeks there were more PMNs/unit area than in controls. The onset of measurable BrdU labeling was delayed in DFMO-treated animals, and the magnitude of labeling was significantly reduced. Increases in astrocyte and vessel numbers/mm{sup 2} were observed after a 2-week delay. At the site of implant, astrocytes from DFMO-treated dogs were significantly smaller than those from controls. There is substantial cell proliferation and infiltration in response to interstitial irradiation of normal brain, and these responses are significantly altered by DFMO treatment. Although the precise mechanisms by which DFMO exerts its effects in this model are not known, the results from this study suggest that modification of radiation injury may be possible by manipulating the response of normal cells to injury. 57 refs., 6 figs.

  15. Alterations to Functional Analysis Methodology to Clarify the Functions of Low Rate, High Intensity Problem Behavior

    PubMed Central

    Davis, Barbara J; Kahng, SungWoo; Schmidt, Jonathan; Bowman, Lynn G; Boelter, Eric W

    2012-01-01

    Current research provides few suggestions for modifications to functional analysis procedures to accommodate low rate, high intensity problem behavior. This study examined the results of the extended duration functional analysis procedures of Kahng, Abt, and Schonbachler (2001) with six children admitted to an inpatient hospital for the treatment of severe problem behavior. Results of initial functional analyses (Iwata, Dorsey, Slifer, Bauman, & Richman, 1982/1994) were inconclusive for all children because of low levels of responding. The altered functional analyses, which changed multiple variables including the duration of the functional analysis (i.e., 6 or 7 hrs), yielded clear behavioral functions for all six participants. These results add additional support for the utility of an altered analysis of low rate, high intensity problem behavior when standard functional analyses do not yield differentiated results. PMID:23326628

  16. Cellular alterations and enhanced induction of cleft palate after coadministration of retinoic acid and TCDD

    SciTech Connect

    Abbott, B.D.; Birnbaum, L.S. )

    1989-06-15

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and retinoic acid (RA) are both teratogenic in mice. TCDD is a highly toxic, stable environmental contaminant, while RA is a naturally occurring form of vitamin A. Exposure to TCDD induces hydronephrosis and cleft palate, and exposure to RA induces limb defects and cleft palate. Teratology studies previously have shown that the incidence of clefting is higher after exposure to RA + TCDD than would be observed for the same doses of either compound given alone. This study examines the cellular effects which result in cleft palate, after po administration on gestation Day (GD) 10 or 12 of RA + TCDD in corn oil (10 ml/kg total volume). Exposure on GD 10 to 6 micrograms TCDD + 40 mg RA/kg inhibited early growth of the shelves and clefting was due to a failure of shelves to meet and fuse. This effect on mesenchyme was observed in previous studies to occur after exposure on GD 10 to 40 mg/kg RA alone, but not after TCDD alone. After exposure on GD 12 to 6 micrograms TCDD + 80 mg RA/kg, clefting was due to a failure of shelves to fuse after making contact, because the medial cells differentiated into an oral-like epithelium. This response was observed in previous studies to occur after exposure to TCDD alone, but RA alone on GD 12 resulted in differentiation toward nasal-like cells. The interaction between TCDD and RA results in RA-like clefting after exposure on GD 10 and TCDD-like clefting after exposure on GD 12, and this clefting occurs at higher incidences than would occur after the same levels of either agent alone. After exposure on either GD 10 or 12 to RA + TCDD, the programmed cell death of the medial cells does not occur, and these cells continue to express EGF receptors and to bind 125I-EGF. The effects of RA and TCDD may involve modulation of the cells responses to embryonic growth and differentiation factors.

  17. Alterations of idiotypic profiles: The cellular basis of T15 dominance in BALB/c mice

    SciTech Connect

    Wemhoff, G.A.; Quintans, J. )

    1987-01-01

    Phosphorylcholine (PC) is a component of cell walls and membranes from a variety of widely distributed microorganisms. It is highly immunogenic in mice and most murine strains have circulating anti-PC antibodies which are known to confer protection against certain bacterial infections. BALB/c mice offer a striking example of a high responsiveness to PC, a propensity to generate PC-binding myelomas, and a great restriction of idiotype expression in anti-PC antibodies; in fact, most BALB/c anti-PC IgM antibodies express the T15 idiotype marker. Although it has been suspected that T15 dominance is somewhat related to the continuous antigenic load presented by microorganismal flora found in conventional mice, a complete experimental account of how antigenic selection brings about such extreme idiotypic dominance is not yet available. In the studies presented below, we investigated the role played by the host environment, T cells, and antigen in affecting the generation of the anti-PC T15 idiotype profile in lethally irradiated adoptive hosts reconstituted with syngeneic neonatal liver cells. The results presented herein indicate that the transfer of mature carrier-primed T cells with neonatal liver cells does not influence the generation of the T15 idiotype profile. We also demonstrated that anti-T15 idiotype suppressed mice, used as lethally irradiated hosts of immature immunocompetent cells, allow an increased rate of reconstitution of the anti-PC response when compared to nonsuppressed hosts. Since the administration of a T15+ anti-PC antibody inhibits both reconstitution and idiotype expansion, we conclude that T15+ B cells do not self-promote themselves. In contrast, we observed that exposure of adoptive hosts to PC antigens can enhance the anti-PC response and alter the idiotypic profile in favor of T15-bearing clones.

  18. Altered functional brain network connectivity and glutamate system function in transgenic mice expressing truncated Disrupted-in-Schizophrenia 1.

    PubMed

    Dawson, N; Kurihara, M; Thomson, D M; Winchester, C L; McVie, A; Hedde, J R; Randall, A D; Shen, S; Seymour, P A; Hughes, Z A; Dunlop, J; Brown, J T; Brandon, N J; Morris, B J; Pratt, J A

    2015-01-01

    Considerable evidence implicates DISC1 as a susceptibility gene for multiple psychiatric diseases. DISC1 has been intensively studied at the molecular, cellular and behavioral level, but its role in regulating brain connectivity and brain network function remains unknown. Here, we utilize a set of complementary approaches to assess the functional brain network abnormalities present in mice expressing a truncated Disc1 gene (Disc1tr Hemi mice). Disc1tr Hemi mice exhibited hypometabolism in the prefrontal cortex (PFC) and reticular thalamus along with a reorganization of functional brain network connectivity that included compromised hippocampal-PFC connectivity. Altered hippocampal-PFC connectivity in Disc1tr Hemi mice was confirmed by electrophysiological analysis, with Disc1tr Hemi mice showing a reduced probability of presynaptic neurotransmitter release in the monosynaptic glutamatergic hippocampal CA1-PFC projection. Glutamate system dysfunction in Disc1tr Hemi mice was further supported by the attenuated cerebral metabolic response to the NMDA receptor (NMDAR) antagonist ketamine and decreased hippocampal expression of NMDAR subunits 2A and 2B in these animals. These data show that the Disc1 truncation in Disc1tr Hemi mice induces a range of translationally relevant endophenotypes underpinned by glutamate system dysfunction and altered brain connectivity. PMID:25989143

  19. Asbestos-Induced Cellular and Molecular Alteration of Immunocompetent Cells and Their Relationship with Chronic Inflammation and Carcinogenesis

    PubMed Central

    Matsuzaki, Hidenori; Maeda, Megumi; Lee, Suni; Nishimura, Yasumitsu; Kumagai-Takei, Naoko; Hayashi, Hiroaki; Yamamoto, Shoko; Hatayama, Tamayo; Kojima, Yoko; Tabata, Rika; Kishimoto, Takumi; Hiratsuka, Junichi; Otsuki, Takemi

    2012-01-01

    Asbestos causes lung fibrosis known as asbestosis as well as cancers such as malignant mesothelioma and lung cancer. Asbestos is a mineral silicate containing iron, magnesium, and calcium with a core of SiO2. The immunological effect of silica, SiO2, involves the dysregulation of autoimmunity because of the complications of autoimmune diseases found in silicosis. Asbestos can therefore cause alteration of immunocompetent cells to result in a decline of tumor immunity. Additionally, due to its physical characteristics, asbestos fibers remain in the lung, regional lymph nodes, and the pleural cavity, particularly at the opening sites of lymphatic vessels. Asbestos can induce chronic inflammation in these areas due to the production of reactive oxygen/nitrogen species. As a consequence, immunocompetent cells can have their cellular and molecular features altered by chronic and recurrent encounters with asbestos fibers, and there may be modification by the surrounding inflammation, all of which eventually lead to decreased tumor immunity. In this paper, the brief results of our investigation regarding reduction of tumor immunity of immunocompetent cells exposed to asbestos in vitro are discussed, as are our findings concerned with an investigation of chronic inflammation and analyses of peripheral blood samples derived from patients with pleural plaque and mesothelioma that have been exposed to asbestos. PMID:22500091

  20. Effect of Redox Balance Alterations on Cellular Localization of LAT and Downstream T-Cell Receptor Signaling Pathways

    PubMed Central

    Gringhuis, Sonja I.; Papendrecht-van der Voort, Ellen A. M.; Leow, Angela; Levarht, E. W. Nivine; Breedveld, Ferdinand C.; Verweij, Cornelis L.

    2002-01-01

    The integral membrane protein linker for activation of T cells (LAT) is a central adapter protein in the T-cell receptor (TCR)-mediated signaling pathways. The cellular localization of LAT is extremely sensitive to intracellular redox balance alterations. Reduced intracellular levels of the antioxidant glutathione (GSH), a hallmark of chronic oxidative stress, resulted in the membrane displacement of LAT, abrogated TCR-mediated signaling and consequently hyporesponsiveness of T lymphocytes. The membrane displacement of LAT is accompanied by a considerable difference in the mobility of LAT upon native and nonreducing denaturing polyacrylamide gel electrophoresis analysis, a finding indicative of a conformational change. Targeted mutation of redox-sensitive cysteine residues within LAT created LAT mutants which remain membrane anchored under conditions of chronic oxidative stress. The expression of redox-insensitive LAT mutants allows for restoration of TCR-mediated signal transduction, whereas CD28-mediated signaling pathways remained impaired. These results are indicative that the membrane displacement of LAT as a result of redox balance alterations is a consequence of a conformational change interfering with the insertion of LAT into the plasma membrane. Conclusively, the data suggest a role for LAT as a crucial intermediate in the sensitivity of TCR signaling and hence T lymphocytes toward chronic oxidative stress. PMID:11756537

  1. Cellular Functions of NSF: Not Just SNAPs and SNAREs

    PubMed Central

    Zhao, Chunxia; Slevin, John T.; Whiteheart, Sidney W.

    2007-01-01

    NSF is an AAA protein, broadly required for intracellular membrane fusion. NSF functions as a SNARE chaperone which binds, through SNAPs, to SNARE complexes and utilizes the energy of ATP hydrolysis to disassemble them thus facilitating SNARE recycling. While this is a major function of NSF, it does seem to interact with other proteins, such as the AMPA receptor subunit, GluR2, and β2-AR and is thought to affect their trafficking patterns. New data suggest that NSF may be regulated by transient post-translational modifications such as phosphorylation and nitrosylation. These new aspects of NSF function as well as its role in SNARE complex dynamics will be discussed. PMID:17397838

  2. Gravity-induced cellular and molecular processes in plants studied under altered gravity conditions

    NASA Astrophysics Data System (ADS)

    Vagt, Nicole; Braun, Markus

    -rupting the actomyosin system did not impair the sedimentation of statoliths and did not prevent the activation of gravireceptors. However, experiments in microgravity and inhibitor experiments have demonstrated that the actomyosin system optimizes the statolith-receptor interactions by keeping the sedimented statoliths in motion causing a consistent activation of different gravireceptor molecules. Thereby, a triggered gravitropic signal is created which is the basis for a highly sensitive control and readjustment mechanism. In addition, the results of recent parabolic flight studies on the effects of altered gravity conditions on the gene expres-sion pattern of Arabidopsis seedlings support these findings and provide new insight into the molecular basis of the plants response to different acceleration conditions. The work was financially supported by DLR on behalf of Bundesministerium für Wirtschaft und Technologie (50WB0815).

  3. Conserved cellular function and stress-mediated regulation among members of the proteolipid protein family.

    PubMed

    Fernández, María E; Alfonso, Julieta; Brocco, Marcela A; Frasch, Alberto C

    2010-05-01

    Chronic stress causes morphological alterations in the hippocampus of rodents and tree shrews, including atrophy of CA3 dendrites and loss of synapses. The molecular mechanisms underlying these structural changes remain largely unknown. We have previously identified M6a as a stress responsive gene and shown that M6a is involved in filopodium/spine outgrowth and, likely, synapse formation. M6a belongs to the proteolipid protein (PLP) family, all of their members having four transmembrane domains that allow their localization at the plasma membrane. In the present work, we analyzed other members of this family, the closely related M6b as well as PLP and its splice variant DM20. We found that chronic restraint stress in mice reduces M6b and DM20, but not PLP, mRNA levels in the hippocampus. In addition, M6b and DM20, but again not PLP, induce filopodium formation in primary cultures of hippocampal neurons. Several M6b protein isoforms were studied, all of them having similar effects except for the one lacking the transmembrane domains. Our results reveal a conserved cellular function and a stress-mediated regulation among members of the proteolipid protein family, suggesting an involvement of proteolipid proteins in the stress response. PMID:19937804

  4. Mnk kinase pathway: Cellular functions and biological outcomes.

    PubMed

    Joshi, Sonali; Platanias, Leonidas C

    2014-08-26

    The mitogen-activated protein kinase (MAPK) interacting protein kinases 1 and 2 (Mnk1 and Mnk2) play important roles in controlling signals involved in mRNA translation. In addition to the MAPKs (p38 or Erk), multiple studies suggest that the Mnk kinases can be regulated by other known kinases such as Pak2 and/or other unidentified kinases by phosphorylation of residues distinct from the sites phosphorylated by the MAPKs. Several studies have established multiple Mnk protein targets, including PSF, heterogenous nuclear ribonucleoprotein A1, Sprouty 2 and have lead to the identification of distinct biological functions and substrate specificity for the Mnk kinases. In this review we discuss the pathways regulating the Mnk kinases, their known substrates as well as the functional consequences of engagement of pathways controlled by Mnk kinases. These kinases play an important role in mRNA translation via their regulation of eukaryotic initiation factor 4E (eIF4E) and their functions have important implications in tumor biology as well as the regulation of drug resistance to anti-oncogenic therapies. Other studies have identified a role for the Mnk kinases in cap-independent mRNA translation, suggesting that the Mnk kinases can exert important functional effects independently of the phosphorylation of eIF4E. The role of Mnk kinases in inflammation and inflammation-induced malignancies is also discussed. PMID:25225600

  5. VDAC2-specific cellular functions and the underlying structure.

    PubMed

    Naghdi, Shamim; Hajnóczky, György

    2016-10-01

    Voltage Dependent Anion-selective Channel 2 (VDAC2) contributes to oxidative metabolism by sharing a role in solute transport across the outer mitochondrial membrane (OMM) with other isoforms of the VDAC family, VDAC1 and VDAC3. Recent studies revealed that VDAC2 also has a distinctive role in mediating sarcoplasmic reticulum to mitochondria local Ca(2+) transport at least in cardiomyocytes, which is unlikely to be explained simply by the expression level of VDAC2. Furthermore, a strictly isoform-dependent VDAC2 function was revealed in the mitochondrial import and OMM-permeabilizing function of pro-apoptotic Bcl-2 family proteins, primarily Bak in many cell types. In addition, emerging evidence indicates a variety of other isoform-specific engagements for VDAC2. Since VDAC isoforms display 75% sequence similarity, the distinctive structure underlying VDAC2-specific functions is an intriguing problem. In this paper we summarize studies of VDAC2 structure and functions, which suggest a fundamental and exclusive role for VDAC2 in health and disease. This article is part of a Special Issue entitled: Mitochondrial Channels edited by Pierre Sonveaux, Pierre Maechler and Jean-Claude Martinou. PMID:27116927

  6. Altered expression of prohibitin in psoriatic lesions and its cellular implication.

    PubMed

    Kim, Soon Young; Kim, Younghwa; Hwang, Ha Young; Kim, Tae-Yoon

    2007-08-31

    Psoriasis is characterized by excessive proliferation of keratinocytes accompanying acanthosis and incomplete differentiation. Prohibitin was investigated by examining its function of HaCaT as well as psoriasis. Psoriatic involved skin revealed high level of prohibitin in the basal layer. Prohibitin was analyzed by applying RNAi (PHBi) with HaCaT, which demonstrated increased S-phase. PHBi showed enhanced sensitivity to anthralin-mediated cell death due to enhanced loss of mitochondrial membrane potential, suggesting a protective role of prohibitin against apoptosis. Collectively, prohibitin plays a role both in cell cycle regulation and in maintaining mitochondrial integrity, implying its association with pathogenesis of psoriasis. PMID:17618601

  7. Altered expression of prohibitin in psoriatic lesions and its cellular implication

    SciTech Connect

    Kim, Soon Young; Kim, Younghwa; Hwang, Ha Young; Kim, Tae-Yoon . E-mail: tykimder@catholic.ac.kr

    2007-08-31

    Psoriasis is characterized by excessive proliferation of keratinocytes accompanying acanthosis and incomplete differentiation. Prohibitin was investigated by examining its function of HaCaT as well as psoriasis. Psoriatic involved skin revealed high level of prohibitin in the basal layer. Prohibitin was analyzed by applying RNAi (PHBi) with HaCaT, which demonstrated increased S-phase. PHBi showed enhanced sensitivity to anthralin-mediated cell death due to enhanced loss of mitochondrial membrane potential, suggesting a protective role of prohibitin against apoptosis. Collectively, prohibitin plays a role both in cell cycle regulation and in maintaining mitochondrial integrity, implying its association with pathogenesis of psoriasis.

  8. Altered control of cellular proliferation in the absence of mammalian brahma (SNF2alpha).

    PubMed

    Reyes, J C; Barra, J; Muchardt, C; Camus, A; Babinet, C; Yaniv, M

    1998-12-01

    The mammalian SWI-SNF complex is an evolutionarily conserved, multi-subunit machine, involved in chromatin remodelling during transcriptional activation. Within this complex, the BRM (SNF2alpha) and BRG1 (SNF2beta) proteins are mutually exclusive subunits that are believed to affect nucleosomal structures using the energy of ATP hydrolysis. In order to characterize possible differences in the function of BRM and BRG1, and to gain further insights into the role of BRM-containing SWI-SNF complexes, the mouse BRM gene was inactivated by homologous recombination. BRM-/- mice develop normally, suggesting that an observed up-regulation of the BRG1 protein can functionally replace BRM in the SWI-SNF complexes of mutant cells. Nonetheless, adult mutant mice were approximately 15% heavier than control littermates. This may be caused by increased cell proliferation, as demonstrated by a higher mitotic index detected in mutant livers. This is supported further by the observation that mutant embryonic fibroblasts were significantly deficient in their ability to arrest in the G0/G1 phase of the cell cycle in response to cell confluency or DNA damage. These studies suggest that BRM participates in the regulation of cell proliferation in adult mice. PMID:9843504

  9. PTPN13 regulates cellular signalling and β-catenin function during megakaryocytic differentiation.

    PubMed

    Sardina, José L; López-Ruano, Guillermo; Prieto-Bermejo, Rodrigo; Sánchez-Sánchez, Beatriz; Pérez-Fernández, Alejandro; Sánchez-Abarca, Luis Ignacio; Pérez-Simón, José Antonio; Quintales, Luis; Sánchez-Yagüe, Jesús; Llanillo, Marcial; Antequera, Francisco; Hernández-Hernández, Angel

    2014-12-01

    PTPN13 is a high-molecular weight intracellular phosphatase with several isoforms that exhibits a highly modular structure. Although in recent years different roles have been described for PTPN13, we are still far from understanding its function in cell biology. Here we show that PTPN13 expression is activated during megakaryocytic differentiation at the protein and mRNA level. Our results show that the upregulation of PTPN13 inhibits megakaryocytic differentiation, while PTPN13 silencing triggers differentiation. The ability of PTPN13 to alter megakaryocytic differentiation can be explained by its capacity to regulate ERK and STAT signalling. Interestingly, the silencing of β-catenin produced the same effect as PTPN13 downregulation. We demonstrate that both proteins coimmunoprecipitate and colocalise. Moreover, we provide evidence showing that PTPN13 can regulate β-catenin phosphorylation, stability and transcriptional activity. Therefore, the ability of PTPN13 to control megakaryocytic differentiation must be intimately linked to the regulation of β-catenin function. Moreover, our results show for the first time that PTPN13 is stabilised upon Wnt signalling, which makes PTPN13 an important player in canonical Wnt signalling. Our results show that PTPN13 behaves as an important regulator of megakaryocytic differentiation in cell lines and also in murine haematopoietic progenitors. This importance can be explained by the ability of PTPN13 to regulate cellular signalling, and especially through the regulation of β-catenin stability and function. Our results hold true for different megakaryocytic cell lines and also for haematopoietic progenitors, suggesting that these two proteins may play a relevant role during in vivo megakaryopoiesis. PMID:25193362

  10. Altered mitochondrial function after acute alteration of the endogenous insulin/glucagon ratio

    SciTech Connect

    Rohweder-Dunn, G.; Aprille, J.R.

    1986-05-01

    Mannoheptulose (MH) affects pancreatic Islet cells to cause a drop in serum insulin and a rise in glucagon. This effect peaks 1 hr after injection and results in a 3-fold increase in serum glucose. Here they examined whether metabolic functions of liver mitochondria (mito) are altered by this change in hormone status. Rats fed ad lib on 12 hr light/dark cycles were given MH (2g/kg) or vehicle i.p. during the first 2 hrs of the light cycle. Liver mito were isolated 1 hr later. Acid-extracts were assayed for ATP+ADP+AMP (nmol/mg prot). Citrulline synthesis and pyruvate carboxylation rates (nmol/min/mg prot) were assayed by following H(/sup 14/C)O/sub 3//sup -/ fixation in appropriate media. State 3 and 2,4-DNP-uncoupled respiratory rates (1/2 nmol O/sub 2//min/mg prot) were assayed polarographically with succinate. The effects of MH on mito are comparable to reported effects of glucagon injection. MH evokes acute reciprocal changes in insulin and glucagon that are highly reproducible. Thus, MH offers an interesting model for studying the effect of endogenous hormones on mito functions.

  11. Immunoglobulin levels and cellular immune function in lead exposed workers.

    PubMed

    Queiroz, M L; Perlingeiro, R C; Bincoletto, C; Almeida, M; Cardoso, M P; Dantas, D C

    1994-02-01

    The immunological status of lead acid battery workers with blood lead levels and urinary delta-aminolevulinic acid (ALA-U) concentrations ranging from safe to toxic levels has been examined and compared with those of non-exposed, age and sex matched controls. No differences in the serum concentrations of IgG, IgA and IgM between the populations were observed and there existed no correlation between blood lead level or ALA-U concentrations and serum immunoglobulin levels. In addition assessment was made of the capacity of peripheral blood mononuclear cells to respond to the mitogen phytohaemagglutinin (PHA), a correlate of T cell function. As before, there was no difference between exposed and control populations and no correlation between reactivity and blood lead concentration. Our data suggest that chronic exposure to lead fail to compromise lymphocyte function in man. PMID:8169320

  12. Extraocular muscle: cellular adaptations for a diverse functional repertoire.

    PubMed

    Porter, John D

    2002-04-01

    Oculomotor control systems are considerably more complex and diverse than are spinal skeletomotor systems. Moreover, individual skeletal muscles are frequently functional role-specific, while all extraocular muscles operate across a very wide dynamic range. We contend that the novel phenotype of the extraocular muscles is a direct consequence of the functional demands imposed upon this muscle group by the central eye movement controllers. This review highlights five basic themes of extraocular muscle biology that set them apart from more typical skeletal muscles, specifically, the (a) novel innervation pattern, (b) heterogeneity in contractile proteins, (c) structural and functional compartmentalization of the rectus and oblique muscles, (d) diversity of extraocular muscle fiber types, and (e) relationship between the novel muscle phenotype and the differential response of these muscles in neuromuscular and endocrine disease. Finally, new data from broad genome-wide profiling studies are reviewed, with global gene expression patterns lending substantial support to the notion that the extraocular muscles are fundamentally different from traditional skeletal muscle. This novel eye muscle phenotype represents an adaptation that exploits the full range of variability in skeletal muscle to meet the needs of visuomotor systems. PMID:11960789

  13. Alterations in cognitive and psychological functioning after organic solvent exposure

    SciTech Connect

    Morrow, L.A.; Ryan, C.M.; Hodgson, M.J.; Robin, N. )

    1990-05-01

    Exposure to organic solvents has been linked repeatedly to alterations in both personality and cognitive functioning. To assess the nature and extent of these changes more thoroughly, 32 workers with a history of exposure to mixtures of organic solvents and 32 age- and education-matched blue-collar workers with no history of exposure were assessed with a comprehensive battery of neuropsychological tests. Although both groups were comparable on measures of general intelligence, significant differences were found in virtually all other cognitive domains tested (Learning and Memory, Visuospatial, Attention and Mental Flexibility, Psychomotor Speed). In addition, Minnesota Multiphasic Personality Inventories of exposed workers indicated clinically significant levels of depression, anxiety, somatic concerns and disturbances in thinking. The reported psychological distress was unrelated to degree of cognitive deficit. Finally, several exposure-related variables were associated with poorer performance on tests of memory and visuospatial ability.

  14. Anks3 alters the sub-cellular localization of the Nek7 kinase

    SciTech Connect

    Ramachandran, Haribaskar; Engel, Christina; Müller, Barbara; Dengjel, Jörn; Walz, Gerd; Yakulov, Toma A.

    2015-08-28

    Nephronophthisis (NPH) is an autosomal recessive cystic kidney disease, and a frequent cause of end-stage renal failure in children. To date, 17 NPH-associated gene products (NPHPs) have been identified. Most NPHPs participate in large multi-protein complexes that localize to the cilium and/or basal body; however, the precise composition of these complexes and their biological function remain largely unknown. We recently observed that the ankyrin repeat protein Anks3 interacts with the NPH family member Anks6. Both Anks3 and Anks6 form complexes with multiple other NPHPs, suggesting that both proteins function in similar or overlapping signaling pathways. Here, we show that Anks3, but not Anks6 interacted with the NIMA-related kinase Nek7, and was heavily modified in the presence of Nek7, resulting in an approximately 20 kD increase in molecular weight. Although mass spectrometry revealed increased serine and threonine phosphorylation of Anks3 primarily within the N-terminal ankyrin repeats also required for Nek7 interaction, the molecular weight increase occurred even in the presence of a kinase-dead Nek7 mutant, indicating that this modification was not caused by Nek7-dependent Anks3 phosphorylation. Furthermore, the Anks3 modification was specific for Nek7, and did not occur in the presence of Nek8. Importantly, Anks3 retained Nek7 in the cytoplasm, suggesting that, Nek7 triggers the modification of Anks3, which in turn prevents the nuclear localization of Nek7. - Highlights: • Anks3 interacted with Nek7 kinase, and was heavily modified in the presence of Nek7. • Anks3 N-terminal ankyrin repeats, but not SAM domain required for Nek7 interaction. • Nek7 increased Ser/Thr phosphorylation of Anks3 primarily within ankyrin domain. • Interaction with Anks3 led to cytoplasmic retention and nuclear exclusion of Nek7.

  15. Anks3 alters the sub-cellular localization of the Nek7 kinase.

    PubMed

    Ramachandran, Haribaskar; Engel, Christina; Müller, Barbara; Dengjel, Jörn; Walz, Gerd; Yakulov, Toma A

    2015-08-28

    Nephronophthisis (NPH) is an autosomal recessive cystic kidney disease, and a frequent cause of end-stage renal failure in children. To date, 17 NPH-associated gene products (NPHPs) have been identified. Most NPHPs participate in large multi-protein complexes that localize to the cilium and/or basal body; however, the precise composition of these complexes and their biological function remain largely unknown. We recently observed that the ankyrin repeat protein Anks3 interacts with the NPH family member Anks6. Both Anks3 and Anks6 form complexes with multiple other NPHPs, suggesting that both proteins function in similar or overlapping signaling pathways. Here, we show that Anks3, but not Anks6 interacted with the NIMA-related kinase Nek7, and was heavily modified in the presence of Nek7, resulting in an approximately 20 kD increase in molecular weight. Although mass spectrometry revealed increased serine and threonine phosphorylation of Anks3 primarily within the N-terminal ankyrin repeats also required for Nek7 interaction, the molecular weight increase occurred even in the presence of a kinase-dead Nek7 mutant, indicating that this modification was not caused by Nek7-dependent Anks3 phosphorylation. Furthermore, the Anks3 modification was specific for Nek7, and did not occur in the presence of Nek8. Importantly, Anks3 retained Nek7 in the cytoplasm, suggesting that, Nek7 triggers the modification of Anks3, which in turn prevents the nuclear localization of Nek7. PMID:26188091

  16. Hyperoxia-Induced Protein Alterations in Renal Rat Tissue: A Quantitative Proteomic Approach to Identify Hyperoxia-Induced Effects in Cellular Signaling Pathways

    PubMed Central

    Hinkelbein, Jochen; Böhm, Lennert; Spelten, Oliver; Sander, David; Soltész, Stefan; Braunecker, Stefan

    2015-01-01

    Introduction. In renal tissue as well as in other organs, supranormal oxygen pressure may lead to deleterious consequences on a cellular level. Additionally, hyperoxia-induced effect in cells and related free radicals may potentially contribute to renal failure. The aim of this study was to analyze time-dependent alterations of rat kidney protein expression after short-term normobaric hyperoxia using proteomics and bioinformatic approaches. Material and Methods. N = 36 Wistar rats were randomized into six different groups: three groups with normobaric hyperoxia (exposure to 100% oxygen for 3 h) and three groups with normobaric normoxia (NN; room air). After hyperoxia exposure, kidneys were removed immediately, after 3 days and after 7 days. Kidney lysates were analyzed by two-dimensional gel electrophoresis followed by peptide mass fingerprinting using tandem mass spectrometry. Statistical analysis was performed with DeCyder 2D software (p < 0.01). Biological functions of differential regulated proteins were studied using functional network analysis (Ingenuity Pathways Analysis and PathwayStudio). Results. Expression of 14 proteins was significantly altered (p < 0.01): eight proteins (MEP1A_RAT, RSSA_RAT, F16P1_RAT, STML2_RAT, BPNT1_RAT, LGMN_RAT, ATPA_RAT, and VDAC1_RAT) were downregulated and six proteins (MTUS1_RAT, F16P1_RAT, ACTG_RAT, ACTB_RAT, 2ABA_RAT, and RAB1A_RAT) were upregulated. Bioinformatic analyses revealed an association of regulated proteins with inflammation. Conclusions. Significant alterations in renal protein expression could be demonstrated for up to 7 days even after short-term hyperoxia. The identified proteins indicate an association with inflammation signaling cascades. MEP1A and VDAC1 could be promising candidates to identify hyperoxic injury in kidney cells. PMID:26106253

  17. Alterations in cellular energy metabolism associated with the antiproliferative effects of the ATM inhibitor KU-55933 and with metformin.

    PubMed

    Zakikhani, Mahvash; Bazile, Miguel; Hashemi, Sina; Javeshghani, Shiva; Avizonis, Daina; St Pierre, Julie; Pollak, Michael N

    2012-01-01

    KU-55933 is a specific inhibitor of the kinase activity of the protein encoded by Ataxia telangiectasia mutated (ATM), an important tumor suppressor gene with key roles in DNA repair. Unexpectedly for an inhibitor of a tumor suppressor gene, KU-55933 reduces proliferation. In view of prior preliminary evidence suggesting defective mitochondrial function in cells of patients with Ataxia Telangiectasia (AT), we examined energy metabolism of cells treated with KU-55933. The compound increased AMPK activation, glucose uptake and lactate production while reducing mitochondrial membrane potential and coupled respiration. The stimulation of glycolysis by KU-55933 did not fully compensate for the reduction in mitochondrial functions, leading to decreased cellular ATP levels and energy stress. These actions are similar to those previously described for the biguanide metformin, a partial inhibitor of respiratory complex I. Both compounds decreased mitochondrial coupled respiration and reduced cellular concentrations of fumarate, malate, citrate, and alpha-ketogluterate. Succinate levels were increased by KU-55933 levels and decreased by metformin, indicating that the effects of ATM inhibition and metformin are not identical. These observations suggest a role for ATM in mitochondrial function and show that both KU-55933 and metformin perturb the TCA cycle as well as oxidative phosphorylation. PMID:23185347

  18. Alterations in Cellular Energy Metabolism Associated with the Antiproliferative Effects of the ATM Inhibitor KU-55933 and with Metformin

    PubMed Central

    Zakikhani, Mahvash; Bazile, Miguel; Hashemi, Sina; Javeshghani, Shiva; Avizonis, Daina; Pierre, Julie St; Pollak, Michael N.

    2012-01-01

    KU-55933 is a specific inhibitor of the kinase activity of the protein encoded by Ataxia telangiectasia mutated (ATM), an important tumor suppressor gene with key roles in DNA repair. Unexpectedly for an inhibitor of a tumor suppressor gene, KU-55933 reduces proliferation. In view of prior preliminary evidence suggesting defective mitochondrial function in cells of patients with Ataxia Telangiectasia (AT), we examined energy metabolism of cells treated with KU-55933. The compound increased AMPK activation, glucose uptake and lactate production while reducing mitochondrial membrane potential and coupled respiration. The stimulation of glycolysis by KU-55933 did not fully compensate for the reduction in mitochondrial functions, leading to decreased cellular ATP levels and energy stress. These actions are similar to those previously described for the biguanide metformin, a partial inhibitor of respiratory complex I. Both compounds decreased mitochondrial coupled respiration and reduced cellular concentrations of fumarate, malate, citrate, and alpha-ketogluterate. Succinate levels were increased by KU-55933 levels and decreased by metformin, indicating that the effects of ATM inhibition and metformin are not identical. These observations suggest a role for ATM in mitochondrial function and show that both KU-55933 and metformin perturb the TCA cycle as well as oxidative phosphorylation. PMID:23185347

  19. Loss of cone cyclic nucleotide-gated channel leads to alterations in light response modulating system and cellular stress response pathways: a gene expression profiling study

    PubMed Central

    Ma, Hongwei; Thapa, Arjun; Morris, Lynsie M.; Michalakis, Stylianos; Biel, Martin; Frank, Mark Barton; Bebak, Melissa; Ding, Xi-Qin

    2013-01-01

    The cone photoreceptor cyclic nucleotide-gated (CNG) channel is essential for central and color vision and visual acuity. Mutations in the channel subunits CNGA3 and CNGB3 are associated with achromatopsia and cone dystrophy. We investigated the gene expression profiles in mouse retina with CNG channel deficiency using whole genome expression microarrays. As cones comprise only 2 to 3% of the total photoreceptor population in the wild-type mouse retina, the mouse lines with CNG channel deficiency on a cone-dominant background, i.e. Cnga3−/−/Nrl−/− and Cngb3−/−/Nrl−/− mice, were used in our study. Comparative data analysis revealed a total of 105 genes altered in Cnga3−/−/Nrl−/− and 92 in Cngb3−/−/Nrl−/− retinas, relative to Nrl−/− retinas, with 27 genes changed in both genotypes. The differentially expressed genes primarily encode proteins associated with cell signaling, cellular function maintenance and gene expression. Ingenuity pathway analysis (IPA) identified 26 and 9 canonical pathways in Cnga3−/−/Nrl−/− and Cngb3−/−/Nrl−/− retinas, respectively, with 6 pathways being shared. The shared pathways include phototransduction, cAMP/PKA-mediated signaling, endothelin signaling, and EIF2/endoplasmic reticulum (ER) stress, whereas the IL-1, CREB, and purine metabolism signaling were found to specifically associate with Cnga3 deficiency. Thus, CNG channel deficiency differentially regulates genes that affect cell processes such as phototransduction, cellular survival and gene expression, and such regulations play a crucial role(s) in the retinal adaptation to impaired cone phototransduction. Though lack of Cnga3 and Cngb3 shares many common pathways, deficiency of Cnga3 causes more significant alterations in gene expression. This work provides insights into how cones respond to impaired phototransduction at the gene expression levels. PMID:23740940

  20. Loss of cone cyclic nucleotide-gated channel leads to alterations in light response modulating system and cellular stress response pathways: a gene expression profiling study.

    PubMed

    Ma, Hongwei; Thapa, Arjun; Morris, Lynsie M; Michalakis, Stylianos; Biel, Martin; Frank, Mark Barton; Bebak, Melissa; Ding, Xi-Qin

    2013-10-01

    The cone photoreceptor cyclic nucleotide-gated (CNG) channel is essential for central and color vision and visual acuity. Mutations in the channel subunits CNGA3 and CNGB3 are associated with achromatopsia and cone dystrophy. We investigated the gene expression profiles in mouse retina with CNG channel deficiency using whole genome expression microarrays. As cones comprise only 2 to 3% of the total photoreceptor population in the wild-type mouse retina, the mouse lines with CNG channel deficiency on a cone-dominant background, i.e. Cnga3-/-/Nrl-/- and Cngb3-/-/Nrl-/- mice, were used in our study. Comparative data analysis revealed a total of 105 genes altered in Cnga3-/-/Nrl-/- and 92 in Cngb3-/-/Nrl-/- retinas, relative to Nrl-/- retinas, with 27 genes changed in both genotypes. The differentially expressed genes primarily encode proteins associated with cell signaling, cellular function maintenance and gene expression. Ingenuity pathway analysis (IPA) identified 26 and 9 canonical pathways in Cnga3-/-/Nrl-/- and Cngb3-/-/Nrl-/- retinas, respectively, with 6 pathways being shared. The shared pathways include phototransduction, cAMP/PKA-mediated signaling, endothelin signaling, and EIF2/endoplasmic reticulum (ER) stress, whereas the IL-1, CREB, and purine metabolism signaling were found to specifically associate with Cnga3 deficiency. Thus, CNG channel deficiency differentially regulates genes that affect cell processes such as phototransduction, cellular survival and gene expression, and such regulations play a crucial role(s) in the retinal adaptation to impaired cone phototransduction. Though lack of Cnga3 and Cngb3 shares many common pathways, deficiency of Cnga3 causes more significant alterations in gene expression. This work provides insights into how cones respond to impaired phototransduction at the gene expression levels. PMID:23740940

  1. Curcumin inhibits cellular condensation and alters microfilament organization during chondrogenic differentiation of limb bud mesenchymal cells.

    PubMed

    Kim, Dong Kyun; Kim, Song Ja; Kang, Shin Sung; Jin, Eun Jung

    2009-09-30

    Curcumin is a well known natural polyphenol product isolated from the rhizome of the plant Curcuma longa, anti-inflammatory agent for arthritis by inhibiting synthesis of inflammatory prostaglandins. However, the mechanisms by which curcumin regulates the functions of chondroprogenitor, such as proliferation, precartilage condensation, cytoskeletal organization or overall chondrogenic behavior, are largely unknown. In the present report, we investigated the effects and signaling mechanism of curcumin on the regulation of chondrogenesis. Treating chick limb bud mesenchymal cells with curcumin suppressed chondrogenesis by stimulating apoptotic cell death. It also inhibited reorganization of the actin cytoskeleton into a cortical pattern concomitant with rounding of chondrogenic competent cells and down-regulation of integrin beta1 and focal adhesion kinase (FAK) phosphorylation. Curcumin suppressed the phosphorylation of Akt leading to Akt inactivation. Activation of Akt by introducing a myristoylated, constitutively active form of Akt reversed the inhibitory actions of curcumin during chondrogenesis. In summary, for the first time, we describe biological properties of curcumin during chondrogenic differentiation of chick limb bud mesenchymal cells. Curcumin suppressed chondrogenesis by stimulating apoptotic cell death and down-regulating integrin-mediated reorganization of actin cytoskeleton via modulation of Akt signaling. PMID:19478554

  2. Molecular mechanism and cellular function of MHCII ubiquitination

    PubMed Central

    Oh, Jaehak; Shin, Jeoung-Sook

    2015-01-01

    Summary The major histocompatibility complex class II (MHCII) is ubiquitinated via the evolutionally conserved lysine in the cytoplasmic tail of the β chain in dendritic cells (DCs) and B cells. The ubiquitination is mediated by the membrane-associated RING-CH1 (MARCH1) ubiquitin ligase although it can be also mediated by the homolog ligase MARCH8 in model cell lines. The ubiquitination promotes MHCII endocytosis and lysosomal sorting that results in a reduction in the level of MHCII at cell surface. Functionally, MHCII ubiquitination serves as a means by which DCs suppress MHCII expression and reduce antigen presentation in response to the immune-regulatory cytokine IL-10 and regulatory T cells. Recently, additional roles of MHCII ubiquitination have begun to emerge. MHCII ubiquitination promoted DC production of inflammatory cytokines in response to the Toll-like receptor ligands. It also potentiated DC ability to activate antigen-specific naïve CD4+ T cells while limiting the amount of antigens presented at cell surface. Similarly, MHCII ubiquitination promoted DC activation of CD4+ thymocytes supporting regulatory T-cell development independent of its effect of limiting antigen presentation. Thus, ubiquitination appears to confer MHCII a function independent of presenting antigens by a mechanism yet to be identified. PMID:26085212

  3. Functional and Structural Mimicry of Cellular Protein Kinase A Anchoring Proteins by a Viral Oncoprotein

    PubMed Central

    King, Cason R.; Cohen, Michael J.; Fonseca, Gregory J.; Dirk, Brennan S.; Dikeakos, Jimmy D.; Mymryk, Joe S.

    2016-01-01

    The oncoproteins of the small DNA tumor viruses interact with a plethora of cellular regulators to commandeer control of the infected cell. During infection, adenovirus E1A deregulates cAMP signalling and repurposes it for activation of viral gene expression. We show that E1A structurally and functionally mimics a cellular A-kinase anchoring protein (AKAP). E1A interacts with and relocalizes protein kinase A (PKA) to the nucleus, likely to virus replication centres, via an interaction with the regulatory subunits of PKA. Binding to PKA requires the N-terminus of E1A, which bears striking similarity to the amphipathic α-helical domain present in cellular AKAPs. E1A also targets the same docking-dimerization domain of PKA normally bound by cellular AKAPs. In addition, the AKAP like motif within E1A could restore PKA interaction to a cellular AKAP in which its normal interaction motif was deleted. During infection, E1A successfully competes with endogenous cellular AKAPs for PKA interaction. E1A’s role as a viral AKAP contributes to viral transcription, protein expression and progeny production. These data establish HAdV E1A as the first known viral AKAP. This represents a unique example of viral subversion of a crucial cellular regulatory pathway via structural mimicry of the PKA interaction domain of cellular AKAPs. PMID:27137912

  4. Diabetes-Induced Alterations in the Extracellular Matrix and Their Impact on Myocardial Function

    PubMed Central

    Law, Brittany; Fowlkes, Vennece; Goldsmith, Jack G.; Carver, Wayne; Goldsmith, Edie C.

    2014-01-01

    Diabetes is an increasing public health problem that is expected to escalate in the future due to the growing incidence of obesity in the western world.While this disease is well known for its devastating effects on the kidneys and vascular system, diabetic individuals can develop cardiac dysfunction, termed diabetic cardiomyopathy, in the absence of other cardiovascular risk factors such as hypertension or atherosclerosis. While much effort has gone into understanding the effects of elevated glucose or altered insulin sensitivity on cellular components within the heart, significant changes in the cardiac extracellular matrix (ECM) have also been noted. In this review article we highlight what is currently known regarding the effects diabetes has on both the expression and chemical modification of proteins within the ECM and how the fibrotic response often observed as a consequence of this disease can contribute to reduced cardiac function. PMID:22221857

  5. Aflatoxicosis alters avian renal function, calcium, and vitamin D metabolism.

    PubMed

    Glahn, R P; Beers, K W; Bottje, W G; Wideman, R F; Huff, W E; Thomas, W

    1991-11-01

    Experiments were designed to determine the effects of aflatoxicosis on avian renal function, calcium (CA), inorganic phosphorous (Pi), and vitamin D metabolism, and to determine if the effects of aflatoxin are reversible upon discontinuation of toxin administration. Three-week-old male broiler chickens (n = 12 per treatment) received aflatoxin (AF; 2 mg/kg po) or an equal volume of corn oil, the AF carrier vehicle, for 10 consecutive days. After 10 d of treatment, half of the birds from each treatment group were anesthetized and prepared for renal function analysis, which included a 2-h phosphate loading period. Ten days after discontinuation of AF treatment, the remaining birds in each treatment group were anesthetized and prepared for renal function analysis. AF decreased plasma 25-hydroxy vitamin D [25(OH)D] and 1,25-dihydroxy vitamin D [1,25(OH)2D] levels after 5 d of treatment. After 10 d of treatment, urine flow rate (V), fractional sodium excretion (FENa), and fractional potassium excretion (FEK) were lower in AF-treated birds. In addition, total plasma Ca tended to be lower (p = .10) and fractional Ca excretion (FECa) tended to be higher (p = .10) in the AF-treated birds. Intravenous phosphate loading produced a sharp increase in urine hydrogen ion concentration ([H+]) in the AF-treated birds. Glomerular filtration rate (GFR) was reduced and plasma osmolality was increased in AF-treated birds 10 d after discontinuation of toxin administration. The results indicate that AF directly or indirectly affects Ca and Pi metabolism in avians. At the present time, the effects may be related to altered vitamin D and parathyroid hormone (PTH) metabolism. Aflatoxicosis may decrease endogenous PTH synthesis and the renal sensitivity to PTH. The AF-related increase in urine [H+] during phosphate loading is probably due to increased Na+/H+ counterport, suggesting that AF stimulates sodium reabsorption. Also, the decrease in GFR exhibited 10 d after toxin removal indicates

  6. Altering the cellular mechanical force balance results in integrated changes in cell, cytoskeletal and nuclear shape

    NASA Technical Reports Server (NTRS)

    Sims, J. R.; Karp, S.; Ingber, D. E.

    1992-01-01

    Studies were carried out with capillary endothelial cells cultured on fibronectin (FN)-coated dishes in order to analyze the mechanism of cell and nuclear shape control by extracellular matrix (ECM). To examine the role of the cytoskeleton in shape determination independent of changes in transmembrane osmotic pressure, membranes of adherent cells were permeabilized with saponin (25 micrograms/ml) using a buffer that maintains the functional integrity of contractile microfilaments. Real-time videomicroscopic studies revealed that addition of 250 microM ATP resulted in time-dependent retraction and rounding of permeabilized cells and nuclei in a manner similar to that observed in intact living cells following detachment using trypsin-EDTA. Computerized image analysis confirmed that permeabilized cells remained essentially rigid in the absence of ATP and that retraction was stimulated in a dose-dependent manner as the concentration of ATP was raised from 10 to 250 microM. Maximal rounding occurred by 30 min with projected cell and nuclear areas being reduced by 69 and 41%, respectively. ATP-induced rounding was also accompanied by a redistribution of microfilaments resulting in formation of a dense net of F-actin surrounding retracted nuclei. Importantly, ATP-stimulated changes in cell, cytoskeletal, and nuclear form were prevented in permeabilized cells using a synthetic myosin peptide (IRICRKG) that has been previously shown to inhibit actomyosin filament sliding in muscle. In contrast, both the rate and extent of cell and nuclear rounding were increased in permeabilized cells exposed to ATP when the soluble FN peptide, GRGDSP, was used to dislodge immobilized FN from cell surface integrin receptors.(ABSTRACT TRUNCATED AT 250 WORDS).

  7. Cellular functions of phosphatidylinositol 3-phosphate and FYVE domain proteins.

    PubMed Central

    Gillooly, D J; Simonsen, A; Stenmark, H

    2001-01-01

    PtdIns3P is a phosphoinositide 3-kinase product that has been strongly implicated in regulating membrane trafficking in both mammalian and yeast cells. PtdIns3P has been shown to be specifically located on membranes associated with the endocytic pathway. Proteins that contain FYVE zinc-finger domains are recruited to PtdIns3P-containing membranes. Structural information is now available concerning the interaction between FYVE domains and PtdIns3P. A number of proteins have been identified which contain a FYVE domain, and in this review we discuss the functions of PtdIns3P and its FYVE-domain-containing effector proteins in membrane trafficking, cytoskeletal regulation and receptor signalling. PMID:11284710

  8. Media composition: antioxidants/chelators and cellular function.

    PubMed

    Combelles, Catherine M H; Hennet, Margo L

    2012-01-01

    Protection of embryos against oxidative insults during culture is necessary to maintain viability. Generation of excessive levels of reactive oxygen species (ROS) is triggered by various components of the in vitro environment, most of which embryos do not normally encounter in vivo. To compensate for these deficiencies in the culture environment, antioxidants and chelators are often used to control or suppress ROS levels as embryos develop. However, there is no consensus regarding dosage, time of exposure, or appropriate combinations of antioxidants and chelators in embryo culture. In order to elucidate this aspect of an embryo's chemical surroundings in vitro, we present the current knowledge on the function and effect of each antioxidant or chelator that is often included in an embryo culture medium. PMID:22829373

  9. Cellular Functions of Optineurin in Health and Disease.

    PubMed

    Slowicka, Karolina; Vereecke, Lars; van Loo, Geert

    2016-09-01

    Optineurin (OPTN) was initially identified as a regulator of NF-κB and interferon signaling, but attracted most attention because of its association with various human disorders such as glaucoma, Paget disease of bone, and amyotrophic lateral sclerosis. Importantly, OPTN has recently been identified as an autophagy receptor important for the autophagic removal of pathogens, damaged mitochondria, and protein aggregates. This activity is most likely compromised in patients carrying OPTN mutations, and contributes to the observed phenotypes. In this review we summarize recent studies describing the molecular mechanisms by which OPTN controls immunity and autophagy, and discuss these findings in the context of several diseases that have been associated with OPTN (mal)function. PMID:27480243

  10. Stress-induced alterations in large-scale functional networks of the rodent brain.

    PubMed

    Henckens, Marloes J A G; van der Marel, Kajo; van der Toorn, Annette; Pillai, Anup G; Fernández, Guillén; Dijkhuizen, Rick M; Joëls, Marian

    2015-01-15

    Stress-related psychopathology is associated with altered functioning of large-scale brain networks. Animal research into chronic stress, one of the most prominent environmental risk factors for development of psychopathology, has revealed molecular and cellular mechanisms potentially contributing to human mental disease. However, so far, these studies have not addressed the system-level changes in extended brain networks, thought to critically contribute to mental disorders. We here tested the effects of chronic stress exposure (10 days immobilization) on the structural integrity and functional connectivity patterns in the brain, using high-resolution structural MRI, diffusion kurtosis imaging, and resting-state functional MRI, while confirming the expected changes in neuronal dendritic morphology using Golgi-staining. Stress effectiveness was confirmed by a significantly lower body weight and increased adrenal weight. In line with previous research, stressed animals displayed neuronal dendritic hypertrophy in the amygdala and hypotrophy in the hippocampal and medial prefrontal cortex. Using independent component analysis of resting-state fMRI data, we identified ten functional connectivity networks in the rodent brain. Chronic stress appeared to increase connectivity within the somatosensory, visual, and default mode networks. Moreover, chronic stress exposure was associated with an increased volume and diffusivity of the lateral ventricles, whereas no other volumetric changes were observed. This study shows that chronic stress exposure in rodents induces alterations in functional network connectivity strength which partly resemble those observed in stress-related psychopathology. Moreover, these functional consequences of stress seem to be more prominent than the effects on gross volumetric change, indicating their significance for future research. PMID:25462693

  11. Integrative Chemistry: Advanced functional cellular materials bearing multiscale porosity

    NASA Astrophysics Data System (ADS)

    Depardieu, M.; Kinadjian, N.; Backov, R.

    2015-07-01

    With this mini review we show through the sol-gel and emulsion-based Integrative Chemistry how it is possible to trigger materials dimensionality and beyond their functionalities when reaching enhanced applications. In here we focus on 3D macrocellular monolithic foams bearing hierarchical porosities and applications thereof. We first depict the general background of emulsions focusing on concentrated ones, acting as soft templates for the design of PolyHIPE foams, HIPE being the acronym of High Internal Phase Emulsions while encompassing both sol-gel and polymer chemistry. Secondly we extend this approach toward the design of hybrid organic-inorganic foams, labeled Organo-Si(HIPE), where photonics and heterogeneous catalysis applications are addressed. In a third section we show how inorganic Si(HIPE) matrices can be employed as sacrificial hard templates for the generation carbonaceous foams, labeled Carbon(HIPE). These foams being conductive we show applications when employed as electrodes for Li-S battery and as hosts for Li(BH4)-based hydrogen storage.

  12. Hunting alters seedling functional trait composition in a Neotropical forest.

    PubMed

    Kurten, Erin L; Wright, S Joseph; Carson, Walter P

    2015-07-01

    Defaunation alters trophic interactions between plants and vertebrates, whichmay disrupt trophic cascades, thereby favoring a subset of plant species and reducing diversity. If particular functional traits characterize the favored plant species,.then defaunation may alter community-wide patterns of functional trait composition. Changes in plant functional traits occurring with defaunation may help identify the species interactions affected by defaunation and the potential for other cascading effects of defaunation. We tested the hypotheses that defaunation would (1) disrupt seed dispersal, thereby favoring species whose dispersal agents are not affected (e.g., small birds, bats, and abiotic agents), (2) reduce seed predation, thereby favoring larger-seeded species, and (3) reduce herbivory, thereby favoring species with lower leaf mass per area (LMA), leaf toughness, and wood density. We examined how these six traits responded to vertebrate defaunation caused by hunters or by experimental exclosures among more than-30 000 woody seedlings in a lowland tropical moist forest. Exclosures reduced terrestrial frugivores, granivores, and herbivores, while hunters also reduced volant and arboreal frugivores and granivores. The comparison of exclosures and hunting allowed us to parse the impacts of arboreal and volant species (reduced by hunters only) and terrestrial species (reduced by both hunters and exclosures). The loss of terrestrial vertebrates alone had limited effects on plant trait composition. The additional loss of volant and arboreal vertebrates caused significant shifts in plant species composition towards communities with more species dispersed abiotically, including lianas and low wood-density tree species, and fewer species dispersed by large vertebrates. In contrast to previous studies, community seed mass did not decline significantly in hunted sites. Our exclosure results suggest this is because reducing seed predators disproportionately benefits large

  13. Glycosaminoglycan-functionalized poly-lactide-co-glycolide nanoparticles: synthesis, characterization, cytocompatibility, and cellular uptake

    PubMed Central

    Lamichhane, Surya P; Arya, Neha; Ojha, Nirdesh; Kohler, Esther; Shastri, V Prasad

    2015-01-01

    The efficient delivery of chemotherapeutics to the tumor via nanoparticle (NP)-based delivery systems remains a significant challenge. This is compounded by the fact that the tumor is highly dynamic and complex environment composed of a plurality of cell types and extracellular matrix. Since glycosaminoglycan (GAG) production is altered in many diseases (or pathologies), NPs bearing GAG moieties on the surface may confer some unique advantages in interrogating the tumor microenvironment. In order to explore this premise, in the study reported here poly-lactide-co-glycolide (PLGA) NPs in the range of 100–150 nm bearing various proteoglycans were synthesized by a single-step nanoprecipitation and characterized. The surface functionalization of the NPs with GAG moieties was verified using zeta potential measurements and X-ray photoelectron spectroscopy. To establish these GAG-bearing NPs as carriers of therapeutics, cellular toxicity assays were undertaken in lung epithelial adenocarcinoma (A549) cells, human pulmonary microvascular endothelial cells (HPMEC), and renal proximal tubular epithelial cells. In general NPs were well tolerated over a wide concentration range (100–600 μg/mL) by all cell types and were taken up to appreciable extents without any adverse cell response in A549 cells and HPMEC. Further, GAG-functionalized PLGA NPs were taken up to different extents in A459 cells and HPMEC. In both cell systems, the uptake of heparin-modified NPs was diminished by 50%–65% in comparison to that of unmodified PLGA. Interestingly, the uptake of chondroitin sulfate NPs was the highest in both cell systems with 40%–60% higher uptake when compared with that of PLGA, and this represented an almost twofold difference over heparin-modified NPs. These findings suggest that GAG modification can be explored as means of changing the uptake behavior of PLGA NPs and these NP systems have potential in cancer therapy. PMID:25632234

  14. Clinical implications of altered thyroid status in male testicular function.

    PubMed

    Wajner, Simone Magagnin; Wagner, Márcia Santos; Maia, Ana Luiza

    2009-11-01

    Thyroid hormones are involved in the development and maintenance of virtually all tissues. Although for many years the testis was thought to be a thyroid-hormone unresponsive organ, studies of the last decades have demonstrated that thyroid dysfunction is associated not only with abnormalities in morphology and function of testes, but also with decreased fertility and alterations of sexual activity in men. Nowadays, the participation of triiodothyronine (T3) in the control of Sertoli and Leydig cell proliferation, testicular maturation, and steroidogenesis is widely accepted, as well as the presence of thyroid hormone transporters and receptors in testicular cells throughout the development process and in adulthood. But even with data suggesting that T3 may act directly on these cells to bring about its effects, there is still controversy regarding the impact of thyroid diseases on human spermatogenesis and fertility, which can be in part due to the lack of well-controlled clinical studies. The current review aims at presenting an updated picture of recent clinical data about the role of thyroid hormones in male gonadal function. PMID:20126850

  15. Sildenafil alters retinal function in mouse carriers of retinitis pigmentosa.

    PubMed

    Nivison-Smith, Lisa; Zhu, Yuan; Whatham, Andrew; Bui, Bang V; Fletcher, Erica L; Acosta, Monica L; Kalloniatis, Michael

    2014-11-01

    Sildenafil, the active ingredient in Viagra, has been reported to cause transient visual disturbance from inhibition of phosphodiesterase 6 (PDE6), a key enzyme in the visual phototransduction pathway. This study investigated the effects of sildenafil on the rd1(+/-) mouse, a model for carriers of Retinitis Pigmentosa which exhibit normal vision but may have a lower threshold for cellular stress caused by sildenafil due to a heterozygous mutation in PDE6. Sildenafil caused a dose-dependent decrease in electroretinogram (ERG) responses of normal mice which mostly recovered two days post administration. In contrast, rd1(+/-) mice exhibited a significantly reduced photoreceptor and a supernormal bipolar cell response to sildenafil within 1 h of treatment. Carrier mice retinae took two weeks to return to baseline levels suggesting sildenafil has direct effects on both the inner and outer retina and these effects differ significantly between normal and carrier mice. Anatomically, an increase in expression of the early apoptotic marker, cytochrome C in rd1(+/-) mice indicated that the effects of sildenafil on visual function may lead to degeneration. The results of this study are significant considering approximately 1 in 50 people are likely to be carriers of recessive traits leading to retinal degeneration. PMID:25239397

  16. Multicompartmentalized polymeric systems: towards biomimetic cellular structure and function.

    PubMed

    Marguet, Maïté; Bonduelle, Colin; Lecommandoux, Sébastien

    2013-01-21

    The cell is certainly one of the most complex and exciting systems in Nature that scientists are still trying to fully understand. Such a challenge pushes material scientists to seek to reproduce its perfection by building biomimetic materials with high-added value and previously unmatched properties. Thanks to their versatility, their robustness and the current state of polymer chemistry science, we believe polymer-based materials to constitute or represent ideal candidates when addressing the challenge of biomimicry, which defines the focus of this review. The first step consists in mimicking the structure of the cell: its inner compartments, the organelles, with a multicompartmentalized structure, and the rest, i.e. the cytoplasm minus the organelles (mainly cytoskeleton/cytosol) with gels or particular solutions (highly concentrated for example) in one compartment, and finally the combination of both. Achieving this first structural step enables us to considerably widen the gap of possibilities in drug delivery systems. Another powerful property of the cell lies in its metabolic function. The second step is therefore to achieve enzymatic reactions in a compartment, as occurs in the organelles, in a highly controlled, selective and efficient manner. We classify the most exciting polymersome nanoreactors reported in our opinion into two different subsections, depending on their very final concept or purpose of design. We also highlight in a thorough table the experimental sections crucial to such work. Finally, after achieving control over these prerequisites, scientists are able to combine them and push the frontiers of biomimicry further: from cell structure mimics towards a controlled biofunctionality. Such a biomimetic approach in material design and the future research it will stimulate, are believed to bring considerable enrichments to the fields of drug delivery, (bio)sensors, (bio)catalysis and (bio)technology. PMID:23073077

  17. Perfluorinated chemicals: Differential toxicity, inhibition of aromatase activity and alteration of cellular lipids in human placental cells

    SciTech Connect

    Gorrochategui, Eva; Pérez-Albaladejo, Elisabet; Casas, Josefina; Lacorte, Sílvia; Porte, Cinta

    2014-06-01

    The cytotoxicity of eight perfluorinated chemicals (PFCs), namely, perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorododecanoic acid (PFDoA), perfluorobutanesulfonate (PFBS), perfluorohexanesulfonate (PFHxS) and perfluorooctanesulfonate (PFOS) was assessed in the human placental choriocarcinoma cell line JEG-3. Only the long chain PFCs – PFOS, PFDoA, PFNA, PFOA – showed significant cytotoxicity in JEG-3 cells with EC50 values in the range of 107 to 647 μM. The observed cytotoxicity was to some extent related to a higher uptake of the longer chain PFCs by cells (PFDoA > PFOS ≫ PFNA > PFOA > PFHxA). Moreover, this work evidences a high potential of PFOS, PFOA and PFBS to act as aromatase inhibitors in placental cells with IC50s in the range of 57–80 μM, the inhibitory effect of PFBS being particularly important despite the rather low uptake of the compound by cells. Finally, exposure of JEG-3 cells to a mixture of the eight PFCs (0.6 μM each) led to a relative increase (up to 3.4-fold) of several lipid classes, including phosphatidylcholines (PCs), plasmalogen PC and lyso plasmalogen PC, which suggests an interference of PFCs with membrane lipids. Overall, this work highlights the ability of the PFC mixture to alter cellular lipid pattern at concentrations well below those that generate toxicity, and the potential of the short chain PFBS, often considered a safe substitute of PFOS, to significantly inhibit aromatase activity in placental cells. - Highlights: • Eight perfluorinated chemicals of different chain lengths have been selected. • Long chain ones – PFOS, PFDoA, PFNA, PFOA – were cytotoxic in placenta cells. • The uptake of long chain perfluorinated chemicals by cells was comparatively higher. • PFOS, PFOA and the short chain PFBS significantly inhibited aromatase activity. • A mixture of perfluorinated chemicals significantly altered placenta cell

  18. Multi-functionality Redefined with Colloidal Carotene Carbon Nanoparticles for Synchronized Chemical Imaging, Enriched Cellular Uptake and Therapy.

    PubMed

    Misra, Santosh K; Mukherjee, Prabuddha; Chang, Huei-Huei; Tiwari, Saumya; Gryka, Mark; Bhargava, Rohit; Pan, Dipanjan

    2016-01-01

    Typically, multiplexing high nanoparticle uptake, imaging, and therapy requires careful integration of three different functions of a multiscale molecular-particle assembly. Here, we present a simpler approach to multiplexing by utilizing one component of the system for multiple functions. Specifically, we successfully synthesized and characterized colloidal carotene carbon nanoparticle (C(3)-NP), in which a single functional molecule served a threefold purpose. First, the presence of carotene moieties promoted the passage of the particle through the cell membrane and into the cells. Second, the ligand acted as a potent detrimental moiety for cancer cells and, finally, the ligands produced optical contrast for robust microscopic detection in complex cellular environments. In comparative tests, C(3)-NP were found to provide effective intracellular delivery that enables both robust detection at cellular and tissue level and presents significant therapeutic potential without altering the mechanism of intracellular action of β-carotene. Surface coating of C(3) with phospholipid was used to generate C(3)-Lipocoat nanoparticles with further improved function and biocompatibility, paving the path to eventual in vivo studies. PMID:27405011

  19. Multi-functionality Redefined with Colloidal Carotene Carbon Nanoparticles for Synchronized Chemical Imaging, Enriched Cellular Uptake and Therapy

    NASA Astrophysics Data System (ADS)

    Misra, Santosh K.; Mukherjee, Prabuddha; Chang, Huei-Huei; Tiwari, Saumya; Gryka, Mark; Bhargava, Rohit; Pan, Dipanjan

    2016-07-01

    Typically, multiplexing high nanoparticle uptake, imaging, and therapy requires careful integration of three different functions of a multiscale molecular-particle assembly. Here, we present a simpler approach to multiplexing by utilizing one component of the system for multiple functions. Specifically, we successfully synthesized and characterized colloidal carotene carbon nanoparticle (C3-NP), in which a single functional molecule served a threefold purpose. First, the presence of carotene moieties promoted the passage of the particle through the cell membrane and into the cells. Second, the ligand acted as a potent detrimental moiety for cancer cells and, finally, the ligands produced optical contrast for robust microscopic detection in complex cellular environments. In comparative tests, C3-NP were found to provide effective intracellular delivery that enables both robust detection at cellular and tissue level and presents significant therapeutic potential without altering the mechanism of intracellular action of β-carotene. Surface coating of C3 with phospholipid was used to generate C3-Lipocoat nanoparticles with further improved function and biocompatibility, paving the path to eventual in vivo studies.

  20. Multi-functionality Redefined with Colloidal Carotene Carbon Nanoparticles for Synchronized Chemical Imaging, Enriched Cellular Uptake and Therapy

    PubMed Central

    Misra, Santosh K.; Mukherjee, Prabuddha; Chang, Huei-Huei; Tiwari, Saumya; Gryka, Mark; Bhargava, Rohit; Pan, Dipanjan

    2016-01-01

    Typically, multiplexing high nanoparticle uptake, imaging, and therapy requires careful integration of three different functions of a multiscale molecular-particle assembly. Here, we present a simpler approach to multiplexing by utilizing one component of the system for multiple functions. Specifically, we successfully synthesized and characterized colloidal carotene carbon nanoparticle (C3-NP), in which a single functional molecule served a threefold purpose. First, the presence of carotene moieties promoted the passage of the particle through the cell membrane and into the cells. Second, the ligand acted as a potent detrimental moiety for cancer cells and, finally, the ligands produced optical contrast for robust microscopic detection in complex cellular environments. In comparative tests, C3-NP were found to provide effective intracellular delivery that enables both robust detection at cellular and tissue level and presents significant therapeutic potential without altering the mechanism of intracellular action of β-carotene. Surface coating of C3 with phospholipid was used to generate C3-Lipocoat nanoparticles with further improved function and biocompatibility, paving the path to eventual in vivo studies. PMID:27405011

  1. Altered functional connectivity of the cingulate subregions in schizophrenia.

    PubMed

    Wang, D; Zhou, Y; Zhuo, C; Qin, W; Zhu, J; Liu, H; Xu, L; Yu, C

    2015-01-01

    Schizophrenia patients have shown altered resting-state functional connectivity (rsFC) of the cingulate cortex; however, it is unknown whether rsFCs of the cingulate subregions are differentially affected in this disorder. We aimed to clarify the issue by comparing rsFCs of each cingulate subregion between healthy controls and schizophrenia patients. A total of 102 healthy controls and 94 schizophrenia patients underwent resting-state functional magnetic resonance imaging with a sensitivity-encoded spiral-in imaging sequence to reduce susceptibility-induced signal loss and distortion. The cingulate cortex was divided into nine subregions, including the subgenual anterior cingulate cortex (ACC), areas 24 and 32 of the pregenual ACC, areas 24 and 32 of the anterior mid-cingulate cortex (aMCC), posterior MCC (pMCC), dorsal (dPCC) and ventral (vPCC) posterior cingulate cortex (PCC) and retrosplenial cortex (RSC). The rsFCs of each cingulate subregion were compared between the two groups and the atrophy effect was considered. Results with and without global signal regression were reported. Most cingulate subregions exhibited decreased rsFCs in schizophrenia after global signal regression (GSR). Without GSR, only increased rsFC was found in schizophrenia, which primarily restricted to the aMCC, PCC and RSC. Some of these increased rsFCs were also significant after GSR. These findings suggest that GSR can greatly affect between-group differences in rsFCs and the consistently increased rsFCs may challenge the functional disconnection hypothesis of schizophrenia. PMID:26035059

  2. Altered Functional Response to Risky Choice in HIV Infection

    PubMed Central

    Connolly, Colm G.; Bischoff-Grethe, Amanda; Jordan, Stephan J.; Woods, Steven Paul; Ellis, Ronald J.; Paulus, Martin P.; Grant, Igor

    2014-01-01

    Background Risky decision-making is commonly observed in persons at risk for and infected with HIV and is associated with executive dysfunction. Yet it is currently unknown whether HIV alters brain processing of risk-taking decision-making. Methods This study examined the neural substrate of a risky decision-making task in 21 HIV seropositive (HIV+) and 19 seronegative (HIV-) comparison participants. Functional magnetic resonance imaging was conducted while participants performed the risky-gains task, which involves choosing among safe (20 cents) and risky (40/80 cent win or loss) choices. Linear mixed effects analyses examining group and decision type were conducted. Robust regressions were performed to examine the relationship between nadir CD4 count and Kalichman sexual compulsivity and brain activation in the HIV+ group. The overlap between the task effects and robust regressions was explored. Results Although there were no serostatus effects in behavioral performance on the risky-gains task, HIV+ individuals exhibited greater activation for risky choices in the basal ganglia, i.e. the caudate nucleus, but also in the anterior cingulate, dorsolateral prefrontal cortex, and insula relative to the HIV- group. The HIV+ group also demonstrated reduced functional responses to safe choices in the anterior cingulate and dorsolateral prefrontal cortex relative to the HIV- group. HIV+ individuals with higher nadir CD4 count and greater sexual compulsivity displayed lower differential responses to safe versus risky choices in many of these regions. Conclusions This study demonstrated fronto-striatal loop dysfunction associated with HIV infection during risky decision-making. Combined with similar between-group task behavior, this suggests an adaptive functional response in regions critical to reward and behavioral control in the HIV+ group. HIV-infected individuals with higher CD4 nadirs demonstrated activation patterns more similar to seronegative individuals. This

  3. Bovine spongiform encephalopathy induces misfolding of alleged prion-resistant species cellular prion protein without altering its pathobiological features.

    PubMed

    Vidal, Enric; Fernández-Borges, Natalia; Pintado, Belén; Ordóñez, Montserrat; Márquez, Mercedes; Fondevila, Dolors; Torres, Juan María; Pumarola, Martí; Castilla, Joaquín

    2013-05-01

    Bovine spongiform encephalopathy (BSE) prions were responsible for an unforeseen epizootic in cattle which had a vast social, economic, and public health impact. This was primarily because BSE prions were found to be transmissible to humans. Other species were also susceptible to BSE either by natural infection (e.g., felids, caprids) or in experimental settings (e.g., sheep, mice). However, certain species closely related to humans, such as canids and leporids, were apparently resistant to BSE. In vitro prion amplification techniques (saPMCA) were used to successfully misfold the cellular prion protein (PrP(c)) of these allegedly resistant species into a BSE-type prion protein. The biochemical and biological properties of the new prions generated in vitro after seeding rabbit and dog brain homogenates with classical BSE were studied. Pathobiological features of the resultant prion strains were determined after their inoculation into transgenic mice expressing bovine and human PrP(C). Strain characteristics of the in vitro-adapted rabbit and dog BSE agent remained invariable with respect to the original cattle BSE prion, suggesting that the naturally low susceptibility of rabbits and dogs to prion infections should not alter their zoonotic potential if these animals became infected with BSE. This study provides a sound basis for risk assessment regarding prion diseases in purportedly resistant species. PMID:23637170

  4. Magnesium regulates neural stem cell proliferation in the mouse hippocampus by altering mitochondrial function.

    PubMed

    Jia, Shanshan; Mou, Chengzhi; Ma, Yihe; Han, Ruijie; Li, Xue

    2016-04-01

    In the adult brain, neural stem cells from the subgranular zone (SGZ) of the hippocampus and the subventricular zone (SVZ) of the cortex progress through the following five developmental stages: radial glia-like cells, neural progenitor cells, neuroblasts, immature neurons, and mature neurons. These developmental stages are linked to both neuronal microenvironments and energy metabolism. Neurogenesis is restricted and has been demonstrated to arise from tissue microenvironments. We determined that magnesium, a key nutrient in cellular energy metabolism, affects neural stem cell (NSC) proliferation in cells derived from the embryonic hippocampus by influencing mitochondrial function. Densities of proliferating cells and NSCs both showed their highest values at 0.8 mM [Mg(2+) ]o , whereas lower proliferation rates were observed at 0.4 and 1.4 mM [Mg(2+) ]o . The numbers and sizes of the neurospheres reached the maximum at 0.8 mM [Mg(2+) ]o and were weaker under both low (0.4 mM) and high (1.4 mM) concentrations of magnesium. In vitro experimental evidence demonstrates that extracellular magnesium regulates the number of cultured hippocampal NSCs, affecting both magnesium homeostasis and mitochondrial function. Our findings indicate that the effect of [Mg(2+) ]o on NSC proliferation may lie downstream of alterations in mitochondrial function because mitochondrial membrane potential was highest in the NSCs in the moderate [Mg(2+) ]o (0.8 mM) group and lower in both the low (0.4 mM) and high (1.4 mM) [Mg(2+) ]o groups. Overall, these findings demonstrate a new function for magnesium in the brain in the regulation of hippocampal neural stem cells: affecting their cellular energy metabolism. PMID:26634890

  5. Physiological enzymology: The next frontier in understanding protein structure and function at the cellular level.

    PubMed

    Lee, Irene; Berdis, Anthony J

    2016-01-01

    Historically, the study of proteins has relied heavily on characterizing the activity of a single purified protein isolated from other cellular components. This classic approach allowed scientists to unambiguously define the intrinsic kinetic and chemical properties of that protein. The ultimate hope was to extrapolate this information toward understanding how the enzyme or receptor behaves within its native cellular context. These types of detailed in vitro analyses were necessary to reduce the innate complexities of measuring the singular activity and biochemical properties of a specific enzyme without interference from other enzymes and potential competing substrates. However, recent developments in fields encompassing cell biology, molecular imaging, and chemical biology now provide the unique chemical tools and instrumentation to study protein structure, function, and regulation in their native cellular environment. These advancements provide the foundation for a new field, coined physiological enzymology, which quantifies the function and regulation of enzymes and proteins at the cellular level. In this Special Edition, we explore the area of Physiological Enzymology and Protein Function through a series of review articles that focus on the tools and techniques used to measure the cellular activity of proteins inside living cells. This article is part of a Special Issue entitled: Physiological Enzymology and Protein Functions. PMID:26277093

  6. Reduction of Cellular Expression Levels Is a Common Feature of Functionally Affected Pendrin (SLC26A4) Protein Variants

    PubMed Central

    de Moraes, Vanessa C S; Bernardinelli, Emanuele; Zocal, Nathalia; Fernandez, Jhonathan A; Nofziger, Charity; Castilho, Arthur M; Sartorato, Edi L; Paulmichl, Markus; Dossena, Silvia

    2016-01-01

    Sequence alterations in the pendrin gene (SLC26A4) leading to functionally affected protein variants are frequently involved in the pathogenesis of syndromic and nonsyndromic deafness. Considering the high number of SLC26A4 sequence alterations reported to date, discriminating between functionally affected and unaffected pendrin protein variants is essential in contributing to determine the genetic cause of deafness in a given patient. In addition, identifying molecular features common to the functionally affected protein variants can be extremely useful to design future molecule-directed therapeutic approaches. Here we show the functional and molecular characterization of six previously uncharacterized pendrin protein variants found in a cohort of 58 Brazilian deaf patients. Two variants (p.T193I and p.L445W) were undetectable in the plasma membrane, completely retained in the endoplasmic reticulum and showed no transport function; four (p.P142L, p.G149R, p.C282Y and p.Q413R) showed reduced function and significant, although heterogeneous, expression levels in the plasma membrane. Importantly, total expression levels of all of the functionally affected protein variants were significantly reduced with respect to the wild-type and a fully functional variant (p.R776C), regardless of their subcellular localization. Interestingly, reduction of expression may also reduce the transport activity of variants with an intrinsic gain of function (p.Q413R). As reduction of overall cellular abundance was identified as a common molecular feature of pendrin variants with affected function, the identification of strategies to prevent reduction in expression levels may represent a crucial step of potential future therapeutic interventions aimed at restoring the transport activity of dysfunctional pendrin variants. PMID:26752218

  7. Fatty Acid Ethyl Esters Disrupt Neonatal Alveolar Macrophage Mitochondria and Derange Cellular Functioning

    PubMed Central

    Mohan, Sowmya S; Ping, Xiao Du; Harris, Frank L; Ronda, Necol J; Brown, Lou Ann S; Gauthier, Theresa W

    2015-01-01

    Background Chronic alcohol exposure alters the function of alveolar macrophages (AM), impairing immune defenses in both adult and neonatal lungs. Fatty acid ethyl esters (FAEEs) are biological markers of prenatal alcohol exposure in newborns. FAEEs contribute to alcohol-induced mitochondrial (MT) damage in multiple organs. We hypothesized that in utero ethanol exposure would increase FAEEs in the neonatal lung and that direct exposure of neonatal AM to FAEEs would contribute to MT injury and cellular dysfunction. Methods FAEEs were measured in neonatal guinea pig lungs after ± in utero ethanol exposure via gas chromatography/mass spectrometry. The NR8383 cell line and freshly isolated neonatal guinea pig AM were exposed to ethyl oleate (EO) in vitro. MT membrane potential, MT reactive oxygen species generation (mROS), phagocytosis, and apoptosis were evaluated after exposure to EO ± the MT-specific antioxidant mito-TEMPO (mitoT) or ± the pan-caspase inhibitor Z-VAD-FMK. Whole lung FAEEs were compared using the Mann–Whitney U-test. Cellular results were analyzed using 1-way analysis of variance, followed by the Student–Newman–Keuls Method for post hoc comparisons. Results In utero ethanol significantly increased ethyl linoleate and the combinations of ethyl oleate + linoleate + linolenate (OLL), and OLL + stearate in the neonatal lung. In vitro EO caused significant MT dysfunction in both NR8383 and primary neonatal AM, as indicated by increased mROS and loss of MT membrane potential. Impaired phagocytosis and apoptosis were significantly increased in both the cell line and primary AM after EO exposure. MitoT conferred significant but only partial protection against EO-induced MT injury, as did caspase inhibition with Z-VAD-FMK. Conclusions In utero ethanol exposure increased FAEEs in the neonatal guinea pig lung. Direct exposure to the FAEE EO significantly contributed to AM dysfunction, in part via oxidant injury to the MT and in part via secondary

  8. Ceramide-induced alterations in dopamine transporter function.

    PubMed

    Riddle, Evan L; Rau, Kristi S; Topham, Matthew K; Hanson, Glen R; Fleckenstein, Annette E

    2003-01-01

    The purpose of this study was to determine the effects of ceramide on dopamine and serotonin (5-HT, 5-hydroxytryptamine) transporters. Exposure of rat striatal synaptosomes to C2-ceramide caused a reversible, concentration-dependent decrease in plasmalemmal dopamine uptake. In contrast, ceramide exposure increased striatal 5-HT synaptosomal uptake. This increase did not appear to be due to an increased uptake by the 5-HT transporter. Rather, the increase appeared to result from an increase in 5-HT transport through the dopamine transporter, an assertion evidenced by findings that this increase: (1) does not occur in hippocampal synaptosomes (i.e., a preparation largely devoid of dopamine transporters), (2) occurs in striatal synaptosomes prepared from para-chloroamphetamine-treated rats (i.e., a preparation lacking 5-HT transporters), (3) is attenuated by pretreatment with methylphenidate (i.e., a relatively selective dopamine reuptake inhibitor) and (4) is inhibited by exposure to exogenous dopamine (i.e., which presumably competes for uptake with 5-HT). Taken together, these results reveal that ceramide is a novel modulator of monoamine transporter function, and may alter the affinity of dopamine transporters for its primary substrate. PMID:12498904

  9. Dynamic alteration in splenic function during acute falciparum malaria

    SciTech Connect

    Looareesuwan, S.; Ho, M.; Wattanagoon, Y.; White, N.J.; Warrell, D.A.; Bunnag, D.; Harinasuta, T.; Wyler, D.J.

    1987-09-10

    Plasmodium-infected erythrocytes lose their normal deformability and become susceptible to splenic filtration. In animal models, this is one mechanism of antimalarial defense. To assess the effect of acute falciparum malaria on splenic filtration, we measured the clearance of heated /sup 51/Cr-labeled autologous erythrocytes in 25 patients with acute falciparum malaria and in 10 uninfected controls. Two groups of patients could be distinguished. Sixteen patients had splenomegaly, markedly accelerated clearance of the labeled erythrocytes (clearance half-time, 8.4 +/- 4.4 minutes (mean +/- SD) vs. 62.5 +/- 36.5 minutes in controls; P less than 0.001), and a lower mean hematocrit than did the patients without splenomegaly (P less than 0.001). In the nine patients without splenomegaly, clearance was normal. After institution of antimalarial chemotherapy, however, the clearance in this group accelerated to supernormal rates similar to those in the patients with splenomegaly, but without the development of detectable splenomegaly. Clearance was not significantly altered by treatment in the group with splenomegaly. Six weeks later, normal clearance rates were reestablished in most patients in both groups. We conclude that splenic clearance of labeled erythrocytes is enhanced in patients with malaria if splenomegaly is present and is enhanced only after treatment if splenomegaly is absent. Whether this enhanced splenic function applies to parasite-infected erythrocytes in patients with malaria and has any clinical benefit will require further studies.

  10. Functional cellular analyses reveal energy metabolism defect and mitochondrial DNA depletion in a case of mitochondrial aconitase deficiency.

    PubMed

    Sadat, Roa; Barca, Emanuele; Masand, Ruchi; Donti, Taraka R; Naini, Ali; De Vivo, Darryl C; DiMauro, Salvatore; Hanchard, Neil A; Graham, Brett H

    2016-05-01

    Defects in the tricarboxylic acid cycle (TCA) are associated with a spectrum of neurological phenotypes that are often difficult to diagnose and manage. Whole-exome sequencing (WES) led to a rapid expansion of diagnostic capabilities in such disorders and facilitated a better understanding of disease pathogenesis, although functional characterization remains a bottleneck to the interpretation of potential pathological variants. We report a 2-year-old boy of Afro-Caribbean ancestry, who presented with neuromuscular symptoms without significant abnormalities on routine diagnostic evaluation. WES revealed compound heterozygous missense variants of uncertain significance in mitochondrial aconitase (ACO2), which encodes the TCA enzyme ACO2. Pathogenic variants in ACO2 have been described in a handful of families as the cause of infantile cerebellar-retinal degeneration syndrome. Using biochemical and cellular assays in patient fibroblasts, we found that ACO2 expression was quantitatively normal, but ACO2 enzyme activity was <20% of that observed in control cells. We also observed a deficiency in cellular respiration and, for the first time, demonstrate evidence of mitochondrial DNA depletion and altered expression of some TCA components and electron transport chain subunits. The observed cellular defects were completely restored with ACO2 gene rescue. Our findings demonstrate the pathogenicity of two VUS in ACO2, provide novel mechanistic insights to TCA disturbances in ACO2 deficiency, and implicate mitochondrial DNA depletion in the pathogenesis of this recently described disorder. PMID:26992325

  11. Does drought alter hydrological functions in forest soils?

    NASA Astrophysics Data System (ADS)

    Gimbel, Katharina; Puhlmann, Heike; Weiler, Markus

    2014-05-01

    Climate change will probably alter precipitation patterns across central Europe, and (summer) droughts are expected to be more frequent and severe in future. Droughts may modify soil properties, such as the pore volume distribution, soil aggregation, water repellency and rooting patterns. These changes in soil properties affect the hydrological functioning of the soil like water retention, infiltration and percolation and thereby the site conditions for plants. The aim of this research is to investigate the effect of droughts on the hydrological functioning of forest soils. We conducted rainfall-reduction experiments in three woodlands (nine investigation sites) across Germany. We established adaptive roofing systems which allow a flexible reduction of the precipitation between 15 % and 65 % of the incoming precipitation depending on the actual precipitation. The impact of the imposed droughts on the soil properties was assessed by repeated analyses of soil aggregation, hydrophobicity and pore volume distribution. Hydrological functioning of the soil was assessed by means of repeated dye tracer sprinkling experiments. Comparing dye tracer images of 2011 with images taken after two years of imposed drought, we found a general shift in infiltration processes depending on the soil type. Sandy soils showed a shift from front-like infiltration towards a more fingered and scattered infiltration. Soils rich in clay tend to develop unstained (= not wetted) areas in the top layer, which might hint to evolving hydrophobicity. This was confirmed by field and laboratory hydrophobicity tests. Further, the same profiles were showing signs of lower permeability in the bottom layers. Similar to hydrophobicity, we want to link the results of soil aggregation and pore volume distribution to the changes in the infiltration pattern. Our study shows that changes in precipitation pattern can severely affect forest soil properties and their hydrological functions. The results of this

  12. Ethanol exposure alters early cardiac function in the looping heart: a mechanism for congenital heart defects?

    PubMed Central

    Gu, Shi; Doughman, Yong Qiu; Peterson, Lindsy M.; Mai, Katherine; McHale, Quinn; Jenkins, Michael W.; Linask, Kersti K.; Rollins, Andrew M.; Watanabe, Michiko

    2013-01-01

    Alcohol-induced congenital heart defects are frequently among the most life threatening and require surgical correction in newborns. The etiology of these defects, collectively known as fetal alcohol syndrome, has been the focus of much study, particularly involving cellular and molecular mechanisms. Few studies have addressed the influential role of altered cardiac function in early embryogenesis because of a lack of tools with the capability to assay tiny beating hearts. To overcome this gap in our understanding, we used optical coherence tomography (OCT), a nondestructive imaging modality capable of micrometer-scale resolution imaging, to rapidly and accurately map cardiovascular structure and hemodynamics in real time under physiological conditions. In this study, we exposed avian embryos to a single dose of alcohol/ethanol at gastrulation when the embryo is sensitive to the induction of birth defects. Late-stage hearts were analyzed using standard histological analysis with a focus on the atrio-ventricular valves. Early cardiac function was assayed using Doppler OCT, and structural analysis of the cardiac cushions was performed using OCT imaging. Our results indicated that ethanol-exposed embryos developed late-stage valvuloseptal defects. At early stages, they exhibited increased regurgitant flow and developed smaller atrio-ventricular cardiac cushions, compared with controls (uninjected and saline-injected embryos). The embryos also exhibited abnormal flexion/torsion of the body. Our evidence suggests that ethanol-induced alterations in early cardiac function have the potential to contribute to late-stage valve and septal defects, thus demonstrating that functional parameters may serve as early and sensitive gauges of cardiac normalcy and abnormalities. PMID:24271490

  13. Ethanol exposure alters early cardiac function in the looping heart: a mechanism for congenital heart defects?

    PubMed

    Karunamuni, Ganga; Gu, Shi; Doughman, Yong Qiu; Peterson, Lindsy M; Mai, Katherine; McHale, Quinn; Jenkins, Michael W; Linask, Kersti K; Rollins, Andrew M; Watanabe, Michiko

    2014-02-01

    Alcohol-induced congenital heart defects are frequently among the most life threatening and require surgical correction in newborns. The etiology of these defects, collectively known as fetal alcohol syndrome, has been the focus of much study, particularly involving cellular and molecular mechanisms. Few studies have addressed the influential role of altered cardiac function in early embryogenesis because of a lack of tools with the capability to assay tiny beating hearts. To overcome this gap in our understanding, we used optical coherence tomography (OCT), a nondestructive imaging modality capable of micrometer-scale resolution imaging, to rapidly and accurately map cardiovascular structure and hemodynamics in real time under physiological conditions. In this study, we exposed avian embryos to a single dose of alcohol/ethanol at gastrulation when the embryo is sensitive to the induction of birth defects. Late-stage hearts were analyzed using standard histological analysis with a focus on the atrio-ventricular valves. Early cardiac function was assayed using Doppler OCT, and structural analysis of the cardiac cushions was performed using OCT imaging. Our results indicated that ethanol-exposed embryos developed late-stage valvuloseptal defects. At early stages, they exhibited increased regurgitant flow and developed smaller atrio-ventricular cardiac cushions, compared with controls (uninjected and saline-injected embryos). The embryos also exhibited abnormal flexion/torsion of the body. Our evidence suggests that ethanol-induced alterations in early cardiac function have the potential to contribute to late-stage valve and septal defects, thus demonstrating that functional parameters may serve as early and sensitive gauges of cardiac normalcy and abnormalities. PMID:24271490

  14. Functional Connectivity Alterations in Epilepsy from Resting-State Functional MRI

    PubMed Central

    Majeed, Waqas; Rajpoot, Nasir

    2015-01-01

    The study of functional brain connectivity alterations induced by neurological disorders and their analysis from resting state functional Magnetic Resonance Imaging (rfMRI) is generally considered to be a challenging task. The main challenge lies in determining and interpreting the large-scale connectivity of brain regions when studying neurological disorders such as epilepsy. We tackle this challenging task by studying the cortical region connectivity using a novel approach for clustering the rfMRI time series signals and by identifying discriminant functional connections using a novel difference statistic measure. The proposed approach is then used in conjunction with the difference statistic to conduct automatic classification experiments for epileptic and healthy subjects using the rfMRI data. Our results show that the proposed difference statistic measure has the potential to extract promising discriminant neuroimaging markers. The extracted neuroimaging markers yield 93.08% classification accuracy on unseen data as compared to 80.20% accuracy on the same dataset by a recent state-of-the-art algorithm. The results demonstrate that for epilepsy the proposed approach confirms known functional connectivity alterations between cortical regions, reveals some new connectivity alterations, suggests potential neuroimaging markers, and predicts epilepsy with high accuracy from rfMRI scans. PMID:26252668

  15. Copper transporters and chaperones: Their function on angiogenesis and cellular signalling.

    PubMed

    Bharathi Devi, S R; Dhivya M, Aloysius; Sulochana, K N

    2016-09-01

    Copper, although known as a micronutrient, has a pivotal role in modulating the cellular metabolism. Many studies have reported the role of copper in angiogenesis. Copper chaperones are intracellular proteins that mediate copper trafficking to various cell organelles. However, the role and function of copper chaperones in relation to angiogenesis has to be further explored. The intracellular copper levels when in excess are deleterious and certain mutations of copper chaperones have been shown to induce cell death and influence various cellular metabolisms. The study of these chaperones will be helpful in understanding the players in the cascade of events in angiogenesis and their role in cellular metabolic pathways. In this review we have briefly listed the copper chaperones associated with angiogenic and metabolic signalling and their function. PMID:27581939

  16. Global functional analyses of cellular responses to pore-forming toxins.

    PubMed

    Kao, Cheng-Yuan; Los, Ferdinand C O; Huffman, Danielle L; Wachi, Shinichiro; Kloft, Nicole; Husmann, Matthias; Karabrahimi, Valbona; Schwartz, Jean-Louis; Bellier, Audrey; Ha, Christine; Sagong, Youn; Fan, Hui; Ghosh, Partho; Hsieh, Mindy; Hsu, Chih-Shen; Chen, Li; Aroian, Raffi V

    2011-03-01

    Here we present the first global functional analysis of cellular responses to pore-forming toxins (PFTs). PFTs are uniquely important bacterial virulence factors, comprising the single largest class of bacterial protein toxins and being important for the pathogenesis in humans of many Gram positive and Gram negative bacteria. Their mode of action is deceptively simple, poking holes in the plasma membrane of cells. The scattered studies to date of PFT-host cell interactions indicate a handful of genes are involved in cellular defenses to PFTs. How many genes are involved in cellular defenses against PFTs and how cellular defenses are coordinated are unknown. To address these questions, we performed the first genome-wide RNA interference (RNAi) screen for genes that, when knocked down, result in hypersensitivity to a PFT. This screen identifies 106 genes (∼0.5% of genome) in seven functional groups that protect Caenorhabditis elegans from PFT attack. Interactome analyses of these 106 genes suggest that two previously identified mitogen-activated protein kinase (MAPK) pathways, one (p38) studied in detail and the other (JNK) not, form a core PFT defense network. Additional microarray, real-time PCR, and functional studies reveal that the JNK MAPK pathway, but not the p38 MAPK pathway, is a key central regulator of PFT-induced transcriptional and functional responses. We find C. elegans activator protein 1 (AP-1; c-jun, c-fos) is a downstream target of the JNK-mediated PFT protection pathway, protects C. elegans against both small-pore and large-pore PFTs and protects human cells against a large-pore PFT. This in vivo RNAi genomic study of PFT responses proves that cellular commitment to PFT defenses is enormous, demonstrates the JNK MAPK pathway as a key regulator of transcriptionally-induced PFT defenses, and identifies AP-1 as the first cellular component broadly important for defense against large- and small-pore PFTs. PMID:21408619

  17. Muscle fatigue in frog semitendinosus: alterations in contractile function

    NASA Technical Reports Server (NTRS)

    Thompson, L. V.; Balog, E. M.; Riley, D. A.; Fitts, R. H.

    1992-01-01

    The purpose of this study was to characterize the contractile properties of the frog semitendinosus (ST) muscle before and during recovery from fatigue, to relate the observed functional changes to alterations in specific steps in the crossbridge model of muscle contraction, and to determine how fatigue affects the force-frequency relationship. The frog ST (22 degrees C) was fatigued by direct electrical stimulation with 100-ms 150-Hz trains at 1/s for 5 min. The fatigue protocol reduced peak twitch (Pt) and tetanic (Po) force to 32 and 8.5% of initial force, respectively. The decline in Pt was less than Po, in part due to a prolongation in the isometric contraction time (CT), which increased to 300% of the initial value. The isometric twitch duration was greatly prolonged as reflected by the lengthened CT and the 800% increase in the one-half relaxation time (1/2RT). Both Pt and Po showed a biphasic recovery, a rapid initial phase (2 min) followed by a slower (40 min) return to the prefatigue force. CT and 1/2RT also recovered in two phases, returning to 160 and 265% of control in the first 5 min. CT returned to the prefatigue value between 35 and 40 min, whereas even at 60 min 1/2RT was 133% of control. The maximal velocity of shortening, determined by the slack test, was significantly reduced [from 6.7 +/- 0.5 to 2.5 +/- 0.4 optimal muscle length/s] at fatigue. The force-frequency relationship was shifted to the left, so that optimal frequency for generating Po was reduced.(ABSTRACT TRUNCATED AT 250 WORDS).

  18. Muscle fatigue in frog semitendinosus: alterations in contractile function.

    PubMed

    Thompson, L V; Balog, E M; Riley, D A; Fitts, R H

    1992-06-01

    The purpose of this study was to characterize the contractile properties of the frog semitendinosus (ST) muscle before and during recovery from fatigue, to relate the observed functional changes to alterations in specific steps in the crossbridge model of muscle contraction, and to determine how fatigue affects the force-frequency relationship. The frog ST (22 degrees C) was fatigued by direct electrical stimulation with 100-ms 150-Hz trains at 1/s for 5 min. The fatigue protocol reduced peak twitch (Pt) and tetanic (Po) force to 32 and 8.5% of initial force, respectively. The decline in Pt was less than Po, in part due to a prolongation in the isometric contraction time (CT), which increased to 300% of the initial value. The isometric twitch duration was greatly prolonged as reflected by the lengthened CT and the 800% increase in the one-half relaxation time (1/2RT). Both Pt and Po showed a biphasic recovery, a rapid initial phase (2 min) followed by a slower (40 min) return to the prefatigue force. CT and 1/2RT also recovered in two phases, returning to 160 and 265% of control in the first 5 min. CT returned to the prefatigue value between 35 and 40 min, whereas even at 60 min 1/2RT was 133% of control. The maximal velocity of shortening, determined by the slack test, was significantly reduced [from 6.7 +/- 0.5 to 2.5 +/- 0.4 optimal muscle length/s] at fatigue. The force-frequency relationship was shifted to the left, so that optimal frequency for generating Po was reduced.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1535482

  19. Mitochondrial (Dys)function in Adipocyte (De)differentiation and Systemic Metabolic Alterations

    PubMed Central

    De Pauw, Aurélia; Tejerina, Silvia; Raes, Martine; Keijer, Jaap; Arnould, Thierry

    2009-01-01

    In mammals, adipose tissue, composed of BAT and WAT, collaborates in energy partitioning and performs metabolic regulatory functions. It is the most flexible tissue in the body, because it is remodeled in size and shape by modifications in adipocyte cell size and/or number, depending on developmental status and energy fluxes. Although numerous reviews have focused on the differentiation program of both brown and white adipocytes as well as on the pathophysiological role of white adipose tissues, the importance of mitochondrial activity in the differentiation or the dedifferentiation programs of adipose cells and in systemic metabolic alterations has not been extensively reviewed previously. Here, we address the crucial role of mitochondrial functions during adipogenesis and in mature adipocytes and discuss the cellular responses of white adipocytes to mitochondrial activity impairment. In addition, we discuss the increase in scientific knowledge regarding mitochondrial functions in the last 10 years and the recent suspicion of mitochondrial dysfunction in several 21st century epidemics (ie, obesity and diabetes), as well as in lipodystrophy found in HIV-treated patients, which can contribute to the development of new therapeutic strategies targeting adipocyte mitochondria. PMID:19700756

  20. Reconciling paradigms of abnormal pulmonary blood flow and quasi-malignant cellular alterations in pulmonary arterial hypertension.

    PubMed

    Happé, C M; Szulcek, R; Voelkel, N F; Bogaard, H J

    2016-08-01

    In pulmonary arterial hypertension (PAH) structural and functional abnormalities of the small lung vessels interact and lead to a progressive increase in pulmonary vascular resistance and right heart failure. A current pathobiological concept characterizes PAH as a 'quasi-malignant' disease focusing on cancer-like alterations in endothelial cells (EC) and the importance of their acquired apoptosis-resistant, hyper-proliferative phenotype in the process of vascular remodeling. While changes in pulmonary blood flow (PBF) have been long-since recognized and linked to the development of PAH, little is known about a possible relationship between an altered PBF and the quasi-malignant cell phenotype in the pulmonary vascular wall. This review summarizes recognized and hypothetical effects of an abnormal PBF on the pulmonary vascular bed and links these to quasi-malignant changes found in the pulmonary endothelium. Here we describe that abnormal PBF does not only trigger a pulmonary vascular cell growth program, but may also maintain the cancer-like phenotype of the endothelium. Consequently, normalization of PBF and EC response to abnormal PBF may represent a treatment strategy in patients with established PAH. PMID:26804008

  1. Low-dose AgNPs reduce lung mechanical function and innate immune defense in the absence of cellular toxicity.

    PubMed

    Botelho, Danielle J; Leo, Bey Fen; Massa, Christopher B; Sarkar, Srijata; Tetley, Terry D; Chung, Kian Fan; Chen, Shu; Ryan, Mary P; Porter, Alexandra E; Zhang, Junfeng; Schwander, Stephan K; Gow, Andrew J

    2016-01-01

    Multiple studies have examined the direct cellular toxicity of silver nanoparticles (AgNPs). However, the lung is a complex biological system with multiple cell types and a lipid-rich surface fluid; therefore, organ level responses may not depend on direct cellular toxicity. We hypothesized that interaction with the lung lining is a critical determinant of organ level responses. Here, we have examined the effects of low dose intratracheal instillation of AgNPs (0.05 μg/g body weight) 20 and 110 nm diameter in size, and functionalized with citrate or polyvinylpyrrolidone. Both size and functionalization were significant factors in particle aggregation and lipid interaction in vitro. One day post-intratracheal instillation lung function was assessed, and bronchoalveolar lavage (BAL) and lung tissue collected. There were no signs of overt inflammation. There was no change in surfactant protein-B content in the BAL but there was loss of surfactant protein-D with polyvinylpyrrolidone (PVP)-stabilized particles. Mechanical impedance data demonstrated a significant increase in pulmonary elastance as compared to control, greatest with 110 nm PVP-stabilized particles. Seven days post-instillation of PVP-stabilized particles increased BAL cell counts, and reduced lung function was observed. These changes resolved by 21 days. Hence, AgNP-mediated alterations in the lung lining and mechanical function resolve by 21 days. Larger particles and PVP stabilization produce the largest disruptions. These studies demonstrate that low dose AgNPs elicit deficits in both mechanical and innate immune defense function, suggesting that organ level toxicity should be considered. PMID:26152688

  2. SIRT1-dependent regulation of chromatin and transcription: linking NAD(+) metabolism and signaling to the control of cellular functions.

    PubMed

    Zhang, Tong; Kraus, W Lee

    2010-08-01

    Sirtuins comprise a family of NAD(+)-dependent protein deacetylases and ADP-ribosyltransferases. Mammalian SIRT1 - a homolog of yeast Sir2, the prototypical member of the sirtuin family - is an important regulator of metabolism, cell differentiation and senescence, stress response, and cancer. As an NAD(+)-dependent enzyme, SIRT1 regulates gene expression programs in response to cellular metabolic status, thereby coordinating metabolic adaptation of the whole organism. Several important mechanisms have emerged for SIRT1-dependent regulation of transcription. First, SIRT1 can modulate chromatin function through direct deacetylation of histones as well as by promoting alterations in the methylation of histones and DNA, leading to the repression of transcription. The latter is accomplished through the recruitment of other nuclear enzymes to chromatin for histone methylation and DNA CpG methylation, suggesting a broader role of SIRT1 in epigenetic regulation. Second, SIRT1 can interact and deacetylate a broad range of transcription factors and coregulators, thereby regulating target gene expression both positively and negatively. Cellular energy state, specifically NAD(+) metabolism, plays a major role in the regulation of SIRT1 activity. Recent studies on the NAD(+) biosynthetic enzymes in the salvage pathway, nicotinamide phosphoribosyltransferase (NAMPT) and nicotinamide mononucleotide adenylyltransferase 1 (NMNAT-1), have revealed important functions for these enzymes in SIRT1-dependent transcription regulation. The collective molecular actions of SIRT1 control specific patterns of gene expression that modulate a wide variety of physiological outcomes. PMID:19879981

  3. Functional Task Test: 1. Sensorimotor changes Associated with Postflight Alterations in Astronaut Functional Task Performance

    NASA Technical Reports Server (NTRS)

    Bloomberg, J. J.; Arzeno, N. H.; Buxton, R. E.; Feiveson, A. H.; Kofman, I. S.; Lee, S. M. C.; Miller, C. A.; Mulavara, A. P.; Platts, S. H.; Peters, B. T.; Phillips, T.; Ploutz-Snyder, L. L.; Reschke, M. F.; Ryder, J. W.; Spiering, B. A.; Stenger, M. B.; Taylor, L. C.; Wickwire, P. J.; Wood, S. J.

    2011-01-01

    Space flight is known to cause alterations in multiple physiological systems including changes in sensorimotor, cardiovascular, and neuromuscular systems. These changes may affect a crewmember s ability to perform critical mission tasks immediately after landing on a planetary surface. The overall goal of this project is to determine the effects of space flight on functional tests that are representative of high priority exploration mission tasks and to identify the key underlying physiological factors that contribute to decrements in performance. This presentation will focus on the sensorimotor contributions to postflight functional performance.

  4. Cellular and molecular functions of hepatic stellate cells in inflammatory responses and liver immunology

    PubMed Central

    2014-01-01

    The liver is a central immunological organ. Liver resident macrophages, Kupffer cells (KC), but also sinusoidal endothelial cells, dendritic cells (DC) and other immune cells are involved in balancing immunity and tolerance against pathogens, commensals or food antigens. Hepatic stellate cells (HSCs) have been primarily characterized as the main effector cells in liver fibrosis, due to their capacity to transdifferentiate into collagen-producing myofibroblasts (MFB). More recent studies elucidated the fundamental role of HSC in liver immunology. HSC are not only the major storage site for dietary vitamin A (Vit A) (retinol, retinoic acid), which is essential for proper function of the immune system. This pericyte further represents a versatile source of many soluble immunological active factors including cytokines [e.g., interleukin 17 (IL-17)] and chemokines [C-C motif chemokine (ligand) 2 (CCL2)], may act as an antigen presenting cell (APC), and has autophagy activity. Additionally, it responds to many immunological triggers via toll-like receptors (TLR) (e.g., TLR4, TLR9) and transduces signals through pathways and mediators traditionally found in immune cells, including the Hedgehog (Hh) pathway or inflammasome activation. Overall, HSC promote rather immune-suppressive responses in homeostasis, like induction of regulatory T cells (Treg), T cell apoptosis (via B7-H1, PDL-1) or inhibition of cytotoxic CD8 T cells. In conditions of liver injury, HSC are important sensors of altered tissue integrity and initiators of innate immune cell activation. Vice versa, several immune cell subtypes interact directly or via soluble mediators with HSC. Such interactions include the mutual activation of HSC (towards MFB) and macrophages or pro-apoptotic signals from natural killer (NK), natural killer T (NKT) and gamma-delta T cells (γδ T-cells) on activated HSC. Current directions of research investigate the immune-modulating functions of HSC in the environment of liver

  5. Disruption of Src Is Associated with Phenotypes Related to Williams-Beuren Syndrome and Altered Cellular Localization of TFII-I1,2

    PubMed Central

    Ivakine, Evgueni A.; Lam, Emily; Deurloo, Marielle; Dida, Joana; Zirngibl, Ralph A.

    2015-01-01

    Abstract Src is a nonreceptor protein tyrosine kinase that is expressed widely throughout the central nervous system and is involved in diverse biological functions. Mice homozygous for a spontaneous mutation in Src (Src thl/thl) exhibited hypersociability and hyperactivity along with impairments in visuospatial, amygdala-dependent, and motor learning as well as an increased startle response to loud tones. The phenotype of Src thl/thl mice showed significant overlap with Williams-Beuren syndrome (WBS), a disorder caused by the deletion of several genes, including General Transcription Factor 2-I (GTF2I). Src phosphorylation regulates the movement of GTF2I protein (TFII-I) between the nucleus, where it is a transcriptional activator, and the cytoplasm, where it regulates trafficking of transient receptor potential cation channel, subfamily C, member 3 (TRPC3) subunits to the plasma membrane. Here, we demonstrate altered cellular localization of both TFII-I and TRPC3 in the Src mutants, suggesting that disruption of Src can phenocopy behavioral phenotypes observed in WBS through its regulation of TFII-I. PMID:26464974

  6. Quantum dots for tracking cellular transport of lectin-functionalized nanoparticles

    SciTech Connect

    Gao Xiaoling; Wang Tao; Wu Bingxian; Chen Jun; Chen Jiyao; Yue Yang; Dai Ning; Chen Hongzhuan Jiang Xinguo

    2008-12-05

    Successful drug delivery by functionalized nanocarriers largely depends on their efficient intracellular transport which has not yet been fully understood. We developed a new tracking technique by encapsulating quantum dots into the core of wheat germ agglutinin-conjugated nanoparticles (WGA-NP) to track cellular transport of functionalized nanocarriers. The resulting nanoparticles showed no changes in particle size, zeta potential or biobinding activity, and the loaded probe presented excellent photostability and tracking ability. Taking advantage of these properties, cellular transport profiles of WGA-NP in Caco-2 cells was demonstrated. The cellular uptake begins with binding of WGA to its receptor at the cell surface. The subsequent endocytosis happened in a cytoskeleton-dependent manner and by means of clathrin and caveolae-mediated mechanisms. After endosome creating, transport occurs to both trans-Golgi and lysosome. Our study provides new evidences for quantum dots as a cellular tracking probe of nanocarriers and helps understand intracellular transport profile of lectin-functionalized nanoparticles.

  7. Needle puncture in rabbit functional spinal units alters rotational biomechanics

    PubMed Central

    Hartman, Robert A.; Bell, Kevin M.; Quan, Bichun; Nuzhao, Yao; Sowa, Gwendolyn A.; Kang, James D.

    2014-01-01

    Study Design An in vitro biomechanical study for rabbit lumbar functional spinal units (FSUs) using a robot-based spine testing system. Objective To elucidate the effect of annular puncture with a 16G needle on mechanical properties in flexion/extension, axial rotation, and lateral bending. Summary of Background Data Needle puncture of the intervertebral disc has been shown to alter mechanical properties of the disc in compression, torsion, and bending. The effect of needle puncture in FSUs, where intact spinal ligaments and facet joints may mitigate or amplify these changes in the disc, on spinal motion segment stability subject to physiological rotations remains unknown. Methods Rabbit FSUs were tested using a robot testing system whose force/moment and position precision were assessed to demonstrate system capability. Flexibility testing methods were developed by load-to-failure testing in flexion/extension, axial rotation, and lateral bending. Subsequent testing methods were used to examine a 16G needle disc puncture and No. 11 blade disc stab (positive control for mechanical disruption). Flexibility testing was used to assess segmental range-of-motion (°), neutral zone stiffness (Nm/°) and width (° and Nm), and elastic zone stiffness before and after annular injury. Results The robot-based system was capable of performing flexibility testing on FSUs—mean precision of force/moment measurements and robot system movements were less than 3% and 1%, respectively, of moment-rotation target values. Flexibility moment targets were 0.3 Nm for flexion and axial rotation and 0.15 Nm for extension and lateral bending. Needle puncture caused significant (p<0.05) changes only in flexion/extension range-of-motion and neutral zone stiffness and width (Nm) compared to pre-intervention. No.11 blade-stab significantly increased range-of-motion in all motions, decreased neutral zone stiffness and width (Nm) in flexion/extension, and increased elastic zone stiffness in

  8. Neutral genetic drift can alter promiscuous protein functions, potentially aiding functional evolution

    PubMed Central

    Bloom, Jesse D; Romero, Philip A; Lu, Zhongyi; Arnold, Frances H

    2007-01-01

    Background Many of the mutations accumulated by naturally evolving proteins are neutral in the sense that they do not significantly alter a protein's ability to perform its primary biological function. However, new protein functions evolve when selection begins to favor other, "promiscuous" functions that are incidental to a protein's original biological role. If mutations that are neutral with respect to a protein's primary biological function cause substantial changes in promiscuous functions, these mutations could enable future functional evolution. Results Here we investigate this possibility experimentally by examining how cytochrome P450 enzymes that have evolved neutrally with respect to activity on a single substrate have changed in their abilities to catalyze reactions on five other substrates. We find that the enzymes have sometimes changed as much as four-fold in the promiscuous activities. The changes in promiscuous activities tend to increase with the number of mutations, and can be largely rationalized in terms of the chemical structures of the substrates. The activities on chemically similar substrates tend to change in a coordinated fashion, potentially providing a route for systematically predicting the change in one activity based on the measurement of several others. Conclusion Our work suggests that initially neutral genetic drift can lead to substantial changes in protein functions that are not currently under selection, in effect poising the proteins to more readily undergo functional evolution should selection favor new functions in the future. Reviewers This article was reviewed by Martijn Huynen, Fyodor Kondrashov, and Dan Tawfik (nominated by Christoph Adami). PMID:17598905

  9. Function of Membrane Rafts in Viral Lifecycles and Host Cellular Response

    PubMed Central

    Takahashi, Tadanobu; Suzuki, Takashi

    2011-01-01

    Membrane rafts are small (10–200 nm) sterol- and sphingolipid-enriched domains that compartmentalize cellular processes. Membrane rafts play an important role in viral infection cycles and viral virulence. Viruses are divided into four main classes, enveloped DNA virus, enveloped RNA virus, nonenveloped DNA virus, and nonenveloped RNA virus. General virus infection cycle is also classified into two sections, the early stage (entry process) and the late stage (assembly, budding, and release processes of virus particles). In the viral cycle, membrane rafts act as a scaffold of many cellular signal transductions, which are associated with symptoms caused by viral infections. In this paper, we describe the functions of membrane rafts in viral lifecycles and host cellular response according to each virus classification, each stage of the virus lifecycle, and each virus-induced signal transduction. PMID:22191032

  10. Functional insights into modulation of BKCa channel activity to alter myometrial contractility

    PubMed Central

    Lorca, Ramón A.; Prabagaran, Monali; England, Sarah K.

    2014-01-01

    The large-conductance voltage- and Ca2+-activated K+ channel (BKCa) is an important regulator of membrane excitability in a wide variety of cells and tissues. In myometrial smooth muscle, activation of BKCa plays essential roles in buffering contractility to maintain uterine quiescence during pregnancy and in the transition to a more contractile state at the onset of labor. Multiple mechanisms of modulation have been described to alter BKCa channel activity, expression, and cellular localization. In the myometrium, BKCa is regulated by alternative splicing, protein targeting to the plasma membrane, compartmentation in membrane microdomains, and posttranslational modifications. In addition, interaction with auxiliary proteins (i.e., β1- and β2-subunits), association with G-protein coupled receptor signaling pathways, such as those activated by adrenergic and oxytocin receptors, and hormonal regulation provide further mechanisms of variable modulation of BKCa channel function in myometrial smooth muscle. Here, we provide an overview of these mechanisms of BKCa channel modulation and provide a context for them in relation to myometrial function. PMID:25132821

  11. Divalent metals stabilize cellular prion proteins and alter the rate of proteinase-K dependent limited proteolysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: The key biochemical event in the pathogenesis of prion diseases is the conversion of normal cellular prion proteins (PrP**c) to the proteinase K (PK) resistant, abnormal form (PrP**sc); however, the cellular mechanisms underlying the conversion remain enigmatic. Binding of divalent ca...

  12. Hydrologic Alteration and Response of Ecosystem Functions to River Restoration

    NASA Astrophysics Data System (ADS)

    Orr, C. H.; Stanley, E. H.

    2005-12-01

    Stream ecology theory suggests that physical and hydrologic setting is often a dominant determinant of ecosystem structure in fluvial systems. Restorationist practitioners may work under the assumption that if the hydrologic parameters that control biological processes are restored, biotic components of interest should be restored as well. This method is sometimes called passive habitat restoration, or an eco-hydromorphic approach. An alternate to this hypothesis is that biological recovery is constrained by a number of other limitations such as distance to a source population, site history, and presence of invasive species. In this scenario, systems will not be restored by hydrologic alterations alone. To address the influence physical setting has on ecological process, we measured three specific ecological responses of streams to hydrologic manipulations separate restoration projects in Central Wisconsin. The projects shared the common trait of being primarily hydrologic alterations. We measured phosphorus retention capacity in a second-order stream before and after a pair of small dam removals, denitrification rates following the reflooding of a leveed floodplain and an approximately 50-year time series of vegetation recolonization on exposed mud flats following dam removal. In each case the measured responses showed unexpectedly large variability and there was not close correlation between physical and ecologic parameters. Such high variability in response to alterations also made it difficult to determine if the restorations met their goals. One conclusion of these studies may be that we need to move beyond hydrologic alterations to address additional manipulations to better meet the goals of specific projects.

  13. Chronic zinc deficiency alters chick gut microbiota composition and function

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zinc (Zn) deficiency is a prevalent micronutrient insufficiency. Although the gut is a vital organ for Zn utilization, and Zn deficiency is associated with impaired intestinal permeability and a global decrease in gastrointestinal health, alterations in the gut microbial ecology of the host under co...

  14. INVASIVE PLANTS HARBOR HUNGRY DETRITIVORES THAT ALTER ECOSYSTEM FUNCTION

    EPA Science Inventory

    Ecosystems are expected to function more efficiently in response to a diverse community of inhabitants. However, biological invasions may change expected relationships between ecosystem function and diversity. We observed increased decomposition, a measure of ecosystem function...

  15. From cells to embryos: the application of femtosecond laser pulses for altering cellular material in complex biological systems

    NASA Astrophysics Data System (ADS)

    Kohli, V.; Elezzabi, A. Y.

    2008-02-01

    We report the application of high-intensity femtosecond laser pulses as a novel tool for manipulating biological specimens. When femtosecond laser pulses were focused to a near diffraction-limited focal spot, cellular material within the laser focal volume was surgically ablated. Several dissection cuts were made in the membrane of live mammalian cells, and membrane surgery was accomplished without inducing cell collapse or disassociation. By altering how the laser pulses were applied, focal adhesions joining live epithelial cells were surgically removed, resulting in single cell isolation. To further examine the versatility of this reported tool, cells were transiently permeabilized for introducing foreign material into the cytoplasm of live mammalian cells. Localizing focused femtosecond laser pulses on the biological membrane resulted in the formation of transient pores, which were harnessed as a pathway for the delivery of exogenous material. Individual mammalian cells were permeabilized in the presence of a hyperosmotic cryoprotective disaccharide. Material delivery was confirmed by measuring the volumetric response of cells permeabilized in 0.2, 0.3, 0.4 and 0.5 M cryoprotective sugar. The survival of permeabilized cells in increasing osmolarity of sugar was assessed using a membrane integrity assay. Further demonstrating the novelty of this reported tool, laser surgery of an aquatic embryo, the zebrafish (Danio rerio), was also performed. Utilizing the transient pores that were formed in the embryonic cells of the zebrafish embryo, an exogenous fluorescent probe FITC, Streptavidin-conjugated quantum dots or plasmid DNA (sCMV) encoding EGFP was introduced into the developing embryonic cells. To determine if the laser induced any short- or long-term effects on development, laser-manipulated embryos were reared to 2 and 7 days post-fertilization and compared to control embryos at the same developmental stages. Light microscopy and scanning electron microscopy

  16. Nanostructures of Designed Geometry and Functionality Enable Regulation of Cellular Signaling Processes

    PubMed Central

    Li, Jie-Ren; Shi, Lifang; Deng, Zhao; Lo, Su Hao; Liu, Gang-yu

    2014-01-01

    Extracellular matrices (ECM) triggered cellular signaling processes often begin with the clustering of the cellular receptors such as integrin and FcεRI. The sizes of these initial protein complexes or clusters are tens to 100 nm in dimension; therefore, engineered nanostructures could provide effective mimics of ECM for investigation and control of the initial and downstream specific signaling process. This current topic discusses recent advances in nanotechnology in the context of design and production of matching chemical functionality and geometry for control of specific cellular signaling processes. Two investigations are reported to demonstrate this concept: (a) how the presentation of antigen at nanometer scale would influence the aggregation of FcεRI, which would impact the formation of activation complexes, leading to rearrangement of actin in cytoskeleton and degranulation or activation of mast cells; (b) how the engineered nanostructure could guide the initial integrin clustering, which would impact the formation of focal adhesion and downstream cell signaling cascades, leading to polarization, migration and morphological changes. Complimentary to engineered ECMs using synthetic ligands or peptides, or topographic control at micrometer scale, nanostructures of designed geometry and chemical functionality provide new and effective biochemical cues for regulation of cellular signaling processes and downstream behaviors. PMID:22783801

  17. Molecular cause and functional impact of altered synaptic lipid signaling due to a prg-1 gene SNP.

    PubMed

    Vogt, Johannes; Yang, Jenq-Wei; Mobascher, Arian; Cheng, Jin; Li, Yunbo; Liu, Xingfeng; Baumgart, Jan; Thalman, Carine; Kirischuk, Sergei; Unichenko, Petr; Horta, Guilherme; Radyushkin, Konstantin; Stroh, Albrecht; Richers, Sebastian; Sahragard, Nassim; Distler, Ute; Tenzer, Stefan; Qiao, Lianyong; Lieb, Klaus; Tüscher, Oliver; Binder, Harald; Ferreiros, Nerea; Tegeder, Irmgard; Morris, Andrew J; Gropa, Sergiu; Nürnberg, Peter; Toliat, Mohammad R; Winterer, Georg; Luhmann, Heiko J; Huai, Jisen; Nitsch, Robert

    2016-01-01

    Loss of plasticity-related gene 1 (PRG-1), which regulates synaptic phospholipid signaling, leads to hyperexcitability via increased glutamate release altering excitation/inhibition (E/I) balance in cortical networks. A recently reported SNP in prg-1 (R345T/mutPRG-1) affects ~5 million European and US citizens in a monoallelic variant. Our studies show that this mutation leads to a loss-of-PRG-1 function at the synapse due to its inability to control lysophosphatidic acid (LPA) levels via a cellular uptake mechanism which appears to depend on proper glycosylation altered by this SNP. PRG-1(+/-) mice, which are animal correlates of human PRG-1(+/mut) carriers, showed an altered cortical network function and stress-related behavioral changes indicating altered resilience against psychiatric disorders. These could be reversed by modulation of phospholipid signaling via pharmacological inhibition of the LPA-synthesizing molecule autotaxin. In line, EEG recordings in a human population-based cohort revealed an E/I balance shift in monoallelic mutPRG-1 carriers and an impaired sensory gating, which is regarded as an endophenotype of stress-related mental disorders. Intervention into bioactive lipid signaling is thus a promising strategy to interfere with glutamate-dependent symptoms in psychiatric diseases. PMID:26671989

  18. Simultaneous characterization of cellular RNA structure and function with in-cell SHAPE-Seq

    PubMed Central

    Watters, Kyle E.; Abbott, Timothy R.; Lucks, Julius B.

    2016-01-01

    Many non-coding RNAs form structures that interact with cellular machinery to control gene expression. A central goal of molecular and synthetic biology is to uncover design principles linking RNA structure to function to understand and engineer this relationship. Here we report a simple, high-throughput method called in-cell SHAPE-Seq that combines in-cell probing of RNA structure with a measurement of gene expression to simultaneously characterize RNA structure and function in bacterial cells. We use in-cell SHAPE-Seq to study the structure–function relationship of two RNA mechanisms that regulate translation in Escherichia coli. We find that nucleotides that participate in RNA–RNA interactions are highly accessible when their binding partner is absent and that changes in RNA structure due to RNA–RNA interactions can be quantitatively correlated to changes in gene expression. We also characterize the cellular structures of three endogenously expressed non-coding RNAs: 5S rRNA, RNase P and the btuB riboswitch. Finally, a comparison between in-cell and in vitro folded RNA structures revealed remarkable similarities for synthetic RNAs, but significant differences for RNAs that participate in complex cellular interactions. Thus, in-cell SHAPE-Seq represents an easily approachable tool for biologists and engineers to uncover relationships between sequence, structure and function of RNAs in the cell. PMID:26350218

  19. Simultaneous characterization of cellular RNA structure and function with in-cell SHAPE-Seq.

    PubMed

    Watters, Kyle E; Abbott, Timothy R; Lucks, Julius B

    2016-01-29

    Many non-coding RNAs form structures that interact with cellular machinery to control gene expression. A central goal of molecular and synthetic biology is to uncover design principles linking RNA structure to function to understand and engineer this relationship. Here we report a simple, high-throughput method called in-cell SHAPE-Seq that combines in-cell probing of RNA structure with a measurement of gene expression to simultaneously characterize RNA structure and function in bacterial cells. We use in-cell SHAPE-Seq to study the structure-function relationship of two RNA mechanisms that regulate translation in Escherichia coli. We find that nucleotides that participate in RNA-RNA interactions are highly accessible when their binding partner is absent and that changes in RNA structure due to RNA-RNA interactions can be quantitatively correlated to changes in gene expression. We also characterize the cellular structures of three endogenously expressed non-coding RNAs: 5S rRNA, RNase P and the btuB riboswitch. Finally, a comparison between in-cell and in vitro folded RNA structures revealed remarkable similarities for synthetic RNAs, but significant differences for RNAs that participate in complex cellular interactions. Thus, in-cell SHAPE-Seq represents an easily approachable tool for biologists and engineers to uncover relationships between sequence, structure and function of RNAs in the cell. PMID:26350218

  20. Physical exercise mitigates doxorubicin-induced brain cortex and cerebellum mitochondrial alterations and cellular quality control signaling.

    PubMed

    Marques-Aleixo, I; Santos-Alves, E; Balça, M M; Moreira, P I; Oliveira, P J; Magalhães, J; Ascensão, A

    2016-01-01

    Doxorubicin (DOX) is a highly effective anti-neoplastic agent, whose clinical use is limited by a dose-dependent mitochondrial toxicity in non-target tissues, including the brain. Here we analyzed the effects of distinct exercise modalities (12-week endurance treadmill-TM or voluntary free-wheel activity-FW) performed before and during sub-chronic DOX treatment on brain cortex and cerebellum mitochondrial bioenergetics, oxidative stress, permeability transition pore (mPTP), and proteins involved in mitochondrial biogenesis, apoptosis and auto(mito)phagy. Male Sprague-Dawley rats were divided into saline-sedentary (SAL+SED), DOX-sedentary (DOX+SED; 7-week DOX (2 mg · kg(-1)per week)), DOX+TM and DOX+FW. Animal behavior and post-sacrifice mitochondrial function were assessed. Oxidative phosphorylation (OXPHOS) subunits, oxidative stress markers or related proteins (SIRT3, p66shc, UCP2, carbonyls, MDA, -SH, aconitase, Mn-SOD), as well as proteins involved in mitochondrial biogenesis (PGC1α and TFAM) were evaluated. Apoptotic signaling was followed through caspases 3, 8 and 9-like activities, Bax, Bcl2, CypD, ANT and cofilin expression. Mitochondrial dynamics (Mfn1, Mfn2, OPA1 and DRP1) and auto(mito)phagy (LC3II, Beclin1, Pink1, Parkin and p62)-related proteins were measured by semi-quantitative Western blotting. DOX impaired behavioral performance, mitochondrial function, including lower resistance to mPTP and increased apoptotic signaling, decreased the content in OXPHOS complex subunits and increased oxidative stress in brain cortex and cerebellum. Molecular markers of mitochondrial biogenesis, dynamics and autophagy were also altered by DOX treatment in both brain subareas. Generally, TM and FW were able to mitigate DOX-related impairments in brain cortex and cerebellum mitochondrial activity, mPTP and apoptotic signaling. We conclude that the alterations in mitochondrial biogenesis, dynamics and autophagy markers induced by exercise performed before and during

  1. Alteration in systemic vascular resistance and cardiac output during acute cellular rejection and recovery in heart transplant recipients.

    PubMed

    Garan, Arthur R; Uriel, Nir; Sayer, Gabriel; Sims, Daniel; Zahner, Doris; Farr, Maryjane; Mancini, Donna; Jorde, Ulrich P

    2010-03-01

    Coronary vascular reserve is impaired during acute cellular rejection of the orthotopically transplanted heart, but changes in the peripheral vasculature during rejection have not been well described. To investigate whether peripheral vascular compensatory mechanisms are preserved after orthotopic heart transplantation (OHT), we longitudinally observed systemic vascular resistance (SVR) and cardiac output (CO) during acute cellular rejection. CO decreased during high-grade acute cellular rejection, and maintenance of mean arterial pressure was achieved by increases in SVR, and these changes did not return to baseline until several months after histologic resolution of rejection. PMID:19875310

  2. Hes1 triggers epithelial-mesenchymal transition (EMT)-like cellular marker alterations and promotes invasion and metastasis of nasopharyngeal carcinoma by activating the PTEN/AKT pathway.

    PubMed

    Wang, Sheng-Chun; Lin, Xiao-Lin; Wang, Hui-Yan; Qin, Yu-Juan; Chen, Lin; Li, Jing; Jia, Jun-Shuang; Shen, Hong-Fen; Yang, Sheng; Xie, Rao-Ying; Wei, Fang; Gao, Fei; Rong, Xiao-Xiang; Yang, Jie; Zhao, Wen-Tao; Zhang, Ting-Ting; Shi, Jun-Wen; Yao, Kai-Tai; Luo, Wei-Ren; Sun, Yan; Xiao, Dong

    2015-11-01

    Overexpression of the transcriptional factor Hes1 (hairy and enhancer of split-1) has been observed in numerous cancers, but the precise roles of Hes1 in epithelial-mesenchymal transition (EMT), cancer invasion and metastasis remain unknown. Our current study firstly revealed that Hes1 upregulation in a cohort of human nasopharyngeal carcinoma (NPC) biopsies is significantly associated with the EMT, invasive and metastatic phenotypes of cancer. In the present study, we found that Hes1 overexpression triggered EMT-like cellular marker alterations of NPC cells, whereas knockdown of Hes1 through shRNA reversed the EMT-like phenotypes, as strongly supported by Hes1-mediated EMT in NPC clinical specimens described above. Gain-of-function and loss-of-function experiments demonstrated that Hes1 promoted the migration and invasion of NPC cells in vitro. In addition, exogenous expression of Hes1 significantly enhanced the metastatic ability of NPC cells in vivo. Chromatin immunoprecipitation (ChIP) assays showed that Hes1 inhibited PTEN expression in NPC cells through binding to PTEN promoter region. Increased Hes1 expression and decreased PTEN expression were also observed in a cohort of NPC biopsies. Additional studies demonstrated that Hes1-induced EMT-like molecular changes and increased motility and invasion of NPC cells were mediated by PTEN. Taken together, our results suggest, for what we believe is the first time, that Hes1 plays an important role in the invasion and metastasis of NPC through inhibiting PTEN expression to trigger EMT-like phenotypes. PMID:26452025

  3. Hes1 triggers epithelial-mesenchymal transition (EMT)-like cellular marker alterations and promotes invasion and metastasis of nasopharyngeal carcinoma by activating the PTEN/AKT pathway

    PubMed Central

    Qin, Yu-Juan; Chen, Lin; Li, Jing; Jia, Jun-Shuang; Shen, Hong-Fen; Yang, Sheng; Xie, Rao-Ying; Wei, Fang; Gao, Fei; Rong, Xiao-Xiang; Yang, Jie; Zhao, Wen-Tao; Zhang, Ting-Ting; Shi, Jun-Wen; Yao, Kai-Tai; Luo, Wei-Ren; Sun, Yan; Xiao, Dong

    2015-01-01

    Overexpression of the transcriptional factor Hes1 (hairy and enhancer of split-1) has been observed in numerous cancers, but the precise roles of Hes1 in epithelial-mesenchymal transition (EMT), cancer invasion and metastasis remain unknown. Our current study firstly revealed that Hes1 upregulation in a cohort of human nasopharyngeal carcinoma (NPC) biopsies is significantly associated with the EMT, invasive and metastatic phenotypes of cancer. In the present study, we found that Hes1 overexpression triggered EMT-like cellular marker alterations of NPC cells, whereas knockdown of Hes1 through shRNA reversed the EMT-like phenotypes, as strongly supported by Hes1-mediated EMT in NPC clinical specimens described above. Gain-of-function and loss-of-function experiments demonstrated that Hes1 promoted the migration and invasion of NPC cells in vitro. In addition, exogenous expression of Hes1 significantly enhanced the metastatic ability of NPC cells in vivo. Chromatin immunoprecipitation (ChIP) assays showed that Hes1 inhibited PTEN expression in NPC cells through binding to PTEN promoter region. Increased Hes1 expression and decreased PTEN expression were also observed in a cohort of NPC biopsies. Additional studies demonstrated that Hes1-induced EMT-like molecular changes and increased motility and invasion of NPC cells were mediated by PTEN. Taken together, our results suggest, for what we believe is the first time, that Hes1 plays an important role in the invasion and metastasis of NPC through inhibiting PTEN expression to trigger EMT-like phenotypes. PMID:26452025

  4. Reduced brain functional reserve and altered functional connectivity in patients with multiple sclerosis.

    PubMed

    Cader, Sarah; Cifelli, Alberto; Abu-Omar, Yasir; Palace, Jacqueline; Matthews, Paul M

    2006-02-01

    Cognitive dysfunction (affecting particularly attention and working memory) occurs early in patients with multiple sclerosis. Previous studies have focused on identifying potentially adaptive functional reorganization through recruitment of new brain regions that could limit expression of these deficits. However, lesion studies remind us that functional specializations in the brain make certain brain regions necessary for a given task. We therefore have asked whether altered functional interactions between regions normally recruited provide an alternative adaptive mechanism with multiple sclerosis pathology. We used a version of the n-back task to probe working memory in patients with early multiple sclerosis. We applied a functional connectivity analysis to test whether relationships between relative activations in different brain regions change in potentially adaptive ways with multiple sclerosis. We studied 21 patients with relapsing-remitting multiple sclerosis and 16 age- and sex-matched healthy controls with 3T functional MRI. The two groups performed equally well on the task. Task-related activations were found in similar regions for patients and controls. However, patients showed relatively reduced activation in the superior frontal and anterior cingulate gyri (P > 0.01). Patients also showed a variable, but generally substantially smaller increase in activation than healthy controls with greater task complexity, depending on the specific brain region assessed (P < 0.001). Functional connectivity analysis defined further differences not apparent from the univariate contrast of the task-associated activation patterns. Control subjects showed significantly greater correlations between right dorsolateral prefrontal and superior frontal/anterior cingulate activations (P < 0.05). Patients showed correlations between activations in the right and left prefrontal cortices, although this relationship was not significant in healthy controls (P < 0.05). We interpret

  5. Inhibitory effects of lysophosphatidic acid receptor-5 on cellular functions of sarcoma cells.

    PubMed

    Araki, Mutsumi; Kitayoshi, Misaho; Dong, Yan; Hirane, Miku; Ozaki, Shuhei; Mori, Shiori; Fukushima, Nobuyuki; Honoki, Kanya; Tsujiuchi, Toshifumi

    2014-06-01

    Lysophosphatidic acid (LPA) is a bioactive lipid that interacts with G protein-coupled LPA receptors (LPA receptor-1 (LPA1) to LPA6). Here, we investigated the effects of LPA signaling via LPA5 on cellular functions of sarcoma cells by generating Lpar5 overexpressing and Lpar5 knockdown cells from rat osteosarcoma and malignant fibrous histiocytoma cells, respectively. The cell motility activity of Lpar5 overexpressing cells was significantly lower, while Lpar5 knockdown cells showed high cell motility, compared with respective controls. Gelatin zymography showed that LPA5 suppressed the activation of matrix metalloproteinase-2. LPA5 also inhibited the cell motility activity of endothelial cells, correlating with the expression levels of vascular endothelial growth factor genes. These results suggest that LPA signaling via LPA5 negatively regulates the cellular functions of rat sarcoma cells. PMID:24798396

  6. Warming Alters Expressions of Microbial Functional Genes Important to Ecosystem Functioning

    PubMed Central

    Xue, Kai; Xie, Jianping; Zhou, Aifen; Liu, Feifei; Li, Dejun; Wu, Liyou; Deng, Ye; He, Zhili; Van Nostrand, Joy D.; Luo, Yiqi; Zhou, Jizhong

    2016-01-01

    Soil microbial communities play critical roles in ecosystem functioning and are likely altered by climate warming. However, so far, little is known about effects of warming on microbial functional gene expressions. Here, we applied functional gene array (GeoChip 3.0) to analyze cDNA reversely transcribed from total RNA to assess expressed functional genes in active soil microbial communities after nine years of experimental warming in a tallgrass prairie. Our results showed that warming significantly altered the community wide gene expressions. Specifically, expressed genes for degrading more recalcitrant carbon were stimulated by warming, likely linked to the plant community shift toward more C4 species under warming and to decrease the long-term soil carbon stability. In addition, warming changed expressed genes in labile C degradation and N cycling in different directions (increase and decrease), possibly reflecting the dynamics of labile C and available N pools during sampling. However, the average abundances of expressed genes in phosphorus and sulfur cycling were all increased by warming, implying a stable trend of accelerated P and S processes which might be a mechanism to sustain higher plant growth. Furthermore, the expressed gene composition was closely related to both dynamic (e.g., soil moisture) and stable environmental attributes (e.g., C4 leaf C or N content), indicating that RNA analyses could also capture certain stable trends in the long-term treatment. Overall, this study revealed the importance of elucidating functional gene expressions of soil microbial community in enhancing our understanding of ecosystem responses to warming. PMID:27199978

  7. Soil restoration with organic amendments: linking cellular functionality and ecosystem processes

    PubMed Central

    Bastida, F.; Selevsek, N.; Torres, I. F.; Hernández, T.; García, C.

    2015-01-01

    A hot topic in recent decades, the application of organic amendments to arid-degraded soils has been shown to benefit microbially-mediated processes. However, despite the importance of soils for global sustainability, a gap has not been addressed yet in soil science: is there any connection between ecosystem-community processes, cellular functionality, and microbial lifestyles (i.e. oligotrophy-copiotrophy) in restored soils? Together with classical ecosystem indicators (fatty-acids, extracellular-enzyme activities, basal respiration), state-of-the-art metaproteomics was applied to fill this gap in a model-restoration experiment initiated 10-years ago by the addition of sewage-sludge and compost. Organic amendment strongly impacted ecosystem processes. Furthermore, the type of material used induced differences in the cellular functionalities through variations in the percentages of proteins involved in translation, transcription, energy production and C-fixation. We conclude that the long-term impact of organic restoration goes beyond ecosystem processes and affects cellular functionalities and phyla-lifestyles coupled with differences in microbial-community structures. PMID:26503516

  8. Soil restoration with organic amendments: linking cellular functionality and ecosystem processes

    NASA Astrophysics Data System (ADS)

    Bastida, F.; Selevsek, N.; Torres, I. F.; Hernández, T.; García, C.

    2015-10-01

    A hot topic in recent decades, the application of organic amendments to arid-degraded soils has been shown to benefit microbially-mediated processes. However, despite the importance of soils for global sustainability, a gap has not been addressed yet in soil science: is there any connection between ecosystem-community processes, cellular functionality, and microbial lifestyles (i.e. oligotrophy-copiotrophy) in restored soils? Together with classical ecosystem indicators (fatty-acids, extracellular-enzyme activities, basal respiration), state-of-the-art metaproteomics was applied to fill this gap in a model-restoration experiment initiated 10-years ago by the addition of sewage-sludge and compost. Organic amendment strongly impacted ecosystem processes. Furthermore, the type of material used induced differences in the cellular functionalities through variations in the percentages of proteins involved in translation, transcription, energy production and C-fixation. We conclude that the long-term impact of organic restoration goes beyond ecosystem processes and affects cellular functionalities and phyla-lifestyles coupled with differences in microbial-community structures.

  9. Soil restoration with organic amendments: linking cellular functionality and ecosystem processes.

    PubMed

    Bastida, F; Selevsek, N; Torres, I F; Hernández, T; García, C

    2015-01-01

    A hot topic in recent decades, the application of organic amendments to arid-degraded soils has been shown to benefit microbially-mediated processes. However, despite the importance of soils for global sustainability, a gap has not been addressed yet in soil science: is there any connection between ecosystem-community processes, cellular functionality, and microbial lifestyles (i.e. oligotrophy-copiotrophy) in restored soils? Together with classical ecosystem indicators (fatty-acids, extracellular-enzyme activities, basal respiration), state-of-the-art metaproteomics was applied to fill this gap in a model-restoration experiment initiated 10-years ago by the addition of sewage-sludge and compost. Organic amendment strongly impacted ecosystem processes. Furthermore, the type of material used induced differences in the cellular functionalities through variations in the percentages of proteins involved in translation, transcription, energy production and C-fixation. We conclude that the long-term impact of organic restoration goes beyond ecosystem processes and affects cellular functionalities and phyla-lifestyles coupled with differences in microbial-community structures. PMID:26503516

  10. Spontaneous Mesotheliomas in F344/N Rats are Characterized by Dysregulation of Cellular Growth and Immune Function Pathways

    PubMed Central

    Blackshear, Pamela E.; Pandiri, Arun R.; Ton, Thai-Vu T.; Clayton, Natasha P.; Shockley, Keith R.; Peddada, Shyamal D.; Gerrish, Kevin E.; Sills, Robert C.; Hoenerhoff, Mark J.

    2016-01-01

    Aged male Fischer 344/N rats are prone to developing spontaneous peritoneal mesotheliomas, which arise predominantly from the tunica vaginalis of the testes. A definitive cause for the predominance of this neoplasm in F344/N rats is unknown. Investigation of the molecular alterations that occur in spontaneous rat mesotheliomas may provide insight into their pathogenesis, as well enable a better understanding regarding the mechanisms underlying chemically induced mesothelioma in rodents. Mesothelial cell function represents a complex interplay of pathways related to host defense mechanisms and maintenance of cellular homeostasis. Global gene expression profiles of spontaneous mesotheliomas from vehicle control male F344/N rats from two-year National Toxicology Program carcinogenicity bioassays were analyzed to determine the molecular features of these tumors, and elucidate tumor-specific gene expression profiles. The resulting gene expression pattern showed that spontaneous mesotheliomas are associated with upregulation various growth factors, oncogenes, cytokines, pattern recognition response receptors (PRR) and pathogen associated molecular patterns (PAMP) receptors, and the production of reactive oxygen and nitrogen species, as well as downregulation of apoptosis pathways. Alterations in these pathways in turn trigger molecular responses that stimulate cell proliferation and promote tumor survival and progression. PMID:23980201