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Sample records for cell functions critical

  1. Empirical evaluation of cell critical volume dose vs. cell response function for pink mutations in tradescantia

    International Nuclear Information System (INIS)

    Varma, M.N.; Bond, V.P.

    1982-01-01

    Microdosimetric spectra for 0.43, 1.8, and 14.7 MeV neutrons, and for 215 kVp x rays and 1250 keV gammas were used in conjunction with relative biological effectiveness (RBE) values for pink mutations in Tradescantia to obtain an effectiveness function (i.e., a cell critical volume dose vs. cell response function). This effectiveness function (or hit size weighting function) provides the probability of inducing a biological effect of interest (in the present study, pink mutations in Tradescantia) as a function of lineal energy density y. In a preliminary analysis the critical value of y above which pink mutations are seen was 4.5 keV/μm, and the value of y at which the probability reaches unity was 115 keV/μm. Idealized but approximate event size distributions for mono-LET particles ranging from 10 to 5000 keV/μm were generated, and these distributions were weighted by the effectiveness function to determine the pink mutation frequencies. Results are compared with measured pink mutation frequencies for 11 keV/μm ( 12 C) and 31 keV/μm ( 20 Ne) ions

  2. Lead roles for supporting actors: critical functions of inner ear supporting cells.

    Science.gov (United States)

    Monzack, Elyssa L; Cunningham, Lisa L

    2013-09-01

    Many studies that aim to investigate the underlying mechanisms of hearing loss or balance disorders focus on the hair cells and spiral ganglion neurons of the inner ear. Fewer studies have examined the supporting cells that contact both of these cell types in the cochlea and vestibular end organs. While the roles of supporting cells are still being elucidated, emerging evidence indicates that they serve many functions vital to maintaining healthy populations of hair cells and spiral ganglion neurons. Here we review recent studies that highlight the critical roles supporting cells play in the development, function, survival, death, phagocytosis, and regeneration of other cell types within the inner ear. Many of these roles have also been described for glial cells in other parts of the nervous system, and lessons from these other systems continue to inform our understanding of supporting cell functions. This article is part of a Special Issue entitled "Annual Reviews 2013". Published by Elsevier B.V.

  3. Phenotype and functions of natural killer cells in critically-ill septic patients.

    Directory of Open Access Journals (Sweden)

    Jean-Marie Forel

    Full Text Available RATIONALE: Natural killer cells, as a major source of interferon-γ, contribute to the amplification of the inflammatory response as well as to mortality during severe sepsis in animal models. OBJECTIVE: We studied the phenotype and functions of circulating NK cells in critically-ill septic patients. METHODS: Blood samples were taken <48 hours after admission from 42 ICU patients with severe sepsis (n = 15 or septic shock (n = 14 (Sepsis group, non-septic SIRS (n = 13 (SIRS group, as well as 21 healthy controls. The immuno-phenotype and functions of NK cells were studied by flow cytometry. RESULTS: The absolute number of peripheral blood CD3-CD56(+ NK cells was similarly reduced in all groups of ICU patients, but with a normal percentage of NK cells. When NK cell cytotoxicity was evaluated with degranulation assays (CD107 expression, no difference was observed between Sepsis patients and healthy controls. Under antibody-dependent cell cytotoxicity (ADCC conditions, SIRS patients exhibited increased CD107 surface expression on NK cells (62.9[61.3-70]% compared to healthy controls (43.5[32.1-53.1]% or Sepsis patients (49.2[37.3-62.9]% (p = 0.002. Compared to healthy (10.2[6.3-13.1]%, reduced interferon-γ production by NK cells (K562 stimulation was observed in Sepsis group (6.2[2.2-9.9]%, p<0.01, and especially in patients with septic shock. Conversely, SIRS patients exhibited increased interferon-γ production (42.9[30.1-54.7]% compared to Sepsis patients (18.4[11.7-35.7]%, p<0.01 or healthy controls (26.8[19.3-44.9]%, p = 0.09 in ADCC condition. CONCLUSIONS: Extensive monitoring of the NK-cell phenotype and function in critically-ill septic patients revealed early decreased NK-cell function with impaired interferon-γ production. These results may aid future NK-based immuno-interventions. TRIAL REGISTRATION: NTC00699868.

  4. FOXA2 regulates a network of genes involved in critical functions of human intestinal epithelial cells.

    Science.gov (United States)

    Gosalia, Nehal; Yang, Rui; Kerschner, Jenny L; Harris, Ann

    2015-07-01

    The forkhead box A (FOXA) family of pioneer transcription factors is critical for the development of many endoderm-derived tissues. Their importance in regulating biological processes in the lung and liver is extensively characterized, though much less is known about their role in intestine. Here we investigate the contribution of FOXA2 to coordinating intestinal epithelial cell function using postconfluent Caco2 cells, differentiated into an enterocyte-like model. FOXA2 binding sites genome-wide were determined by ChIP-seq and direct targets of the factor were validated by ChIP-qPCR and siRNA-mediated depletion of FOXA1/2 followed by RT-qPCR. Peaks of FOXA2 occupancy were frequent at loci contributing to gene ontology pathways of regulation of cell migration, cell motion, and plasma membrane function. Depletion of both FOXA1 and FOXA2 led to a significant reduction in the expression of multiple transmembrane proteins including ion channels and transporters, which form a network that is essential for maintaining normal ion and solute transport. One of the targets was the adenosine A2B receptor, and reduced receptor mRNA levels were associated with a functional decrease in intracellular cyclic AMP. We also observed that 30% of FOXA2 binding sites contained a GATA motif and that FOXA1/A2 depletion reduced GATA-4, but not GATA-6 protein levels. These data show that FOXA2 plays a pivotal role in regulating intestinal epithelial cell function. Moreover, that the FOXA and GATA families of transcription factors may work cooperatively to regulate gene expression genome-wide in the intestinal epithelium. Copyright © 2015 the American Physiological Society.

  5. Dpy30 is critical for maintaining the identity and function of adult hematopoietic stem cells

    Science.gov (United States)

    2016-01-01

    As the major histone H3K4 methyltransferases in mammals, the Set1/Mll complexes play important roles in animal development and are associated with many diseases, including hematological malignancies. However, the role of the H3K4 methylation activity of these complexes in fate determination of hematopoietic stem and progenitor cells (HSCs and HPCs) remains elusive. Here, we address this question by generating a conditional knockout mouse for Dpy30, which is a common core subunit of all Set1/Mll complexes and facilitates genome-wide H3K4 methylation in cells. Dpy30 loss in the adult hematopoietic system results in severe pancytopenia but striking accumulation of HSCs and early HPCs that are defective in multilineage reconstitution, suggesting a differentiation block. In mixed bone marrow chimeras, Dpy30-deficient HSCs cannot differentiate or efficiently up-regulate lineage-regulatory genes, and eventually fail to sustain for long term with significant loss of HSC signature gene expression. Our molecular analyses reveal that Dpy30 directly and preferentially controls H3K4 methylation and expression of many hematopoietic development-associated genes including several key transcriptional and chromatin regulators involved in HSC function. Collectively, our results establish a critical and selective role of Dpy30 and the H3K4 methylation activity of the Set1/Mll complexes for maintaining the identity and function of adult HSCs. PMID:27647347

  6. Dpy30 is critical for maintaining the identity and function of adult hematopoietic stem cells.

    Science.gov (United States)

    Yang, Zhenhua; Shah, Kushani; Khodadadi-Jamayran, Alireza; Jiang, Hao

    2016-10-17

    As the major histone H3K4 methyltransferases in mammals, the Set1/Mll complexes play important roles in animal development and are associated with many diseases, including hematological malignancies. However, the role of the H3K4 methylation activity of these complexes in fate determination of hematopoietic stem and progenitor cells (HSCs and HPCs) remains elusive. Here, we address this question by generating a conditional knockout mouse for Dpy30, which is a common core subunit of all Set1/Mll complexes and facilitates genome-wide H3K4 methylation in cells. Dpy30 loss in the adult hematopoietic system results in severe pancytopenia but striking accumulation of HSCs and early HPCs that are defective in multilineage reconstitution, suggesting a differentiation block. In mixed bone marrow chimeras, Dpy30-deficient HSCs cannot differentiate or efficiently up-regulate lineage-regulatory genes, and eventually fail to sustain for long term with significant loss of HSC signature gene expression. Our molecular analyses reveal that Dpy30 directly and preferentially controls H3K4 methylation and expression of many hematopoietic development-associated genes including several key transcriptional and chromatin regulators involved in HSC function. Collectively, our results establish a critical and selective role of Dpy30 and the H3K4 methylation activity of the Set1/Mll complexes for maintaining the identity and function of adult HSCs. © 2016 Yang et al.

  7. DOCK8 is critical for the survival and function of NKT cells.

    Science.gov (United States)

    Crawford, Greg; Enders, Anselm; Gileadi, Uzi; Stankovic, Sanda; Zhang, Qian; Lambe, Teresa; Crockford, Tanya L; Lockstone, Helen E; Freeman, Alexandra; Arkwright, Peter D; Smart, Joanne M; Ma, Cindy S; Tangye, Stuart G; Goodnow, Christopher C; Cerundolo, Vincenzo; Godfrey, Dale I; Su, Helen C; Randall, Katrina L; Cornall, Richard J

    2013-09-19

    Patients with the dedicator of cytokinesis 8 (DOCK8) immunodeficiency syndrome suffer from recurrent viral and bacterial infections, hyper-immunoglobulin E levels, eczema, and greater susceptibility to cancer. Because natural killer T (NKT) cells have been implicated in these diseases, we asked if these cells were affected by DOCK8 deficiency. Using a mouse model, we found that DOCK8 deficiency resulted in impaired NKT cell development, principally affecting the formation and survival of long-lived, differentiated NKT cells. In the thymus, DOCK8-deficient mice lack a terminally differentiated subset of NK1.1(+) NKT cells expressing the integrin CD103, whereas in the liver, DOCK8-deficient NKT cells express reduced levels of the prosurvival factor B-cell lymphoma 2 and the integrin lymphocyte function-associated antigen 1. Although the initial NKT cell response to antigen is intact in the absence of DOCK8, their ongoing proliferative and cytokine responses are impaired. Importantly, a similar defect in NKT cell numbers was detected in DOCK8-deficient humans, highlighting the relevance of the mouse model. In conclusion, our data demonstrate that DOCK8 is required for the development and survival of mature NKT cells, consistent with the idea that DOCK8 mediates survival signals within a specialized niche. Accordingly, impaired NKT cell numbers and function are likely to contribute to the susceptibility of DOCK8-deficient patients to recurrent infections and malignant disease.

  8. DOCK8 is critical for the survival and function of NKT cells

    Science.gov (United States)

    Crawford, Greg; Enders, Anselm; Gileadi, Uzi; Stankovic, Sanda; Zhang, Qian; Lambe, Teresa; Crockford, Tanya L.; Lockstone, Helen E.; Freeman, Alexandra; Arkwright, Peter D.; Smart, Joanne M.; Ma, Cindy S.; Tangye, Stuart G.; Goodnow, Christopher C.; Cerundolo, Vincenzo; Godfrey, Dale I.; Su, Helen C.; Randall, Katrina L.

    2013-01-01

    Patients with the dedicator of cytokinesis 8 (DOCK8) immunodeficiency syndrome suffer from recurrent viral and bacterial infections, hyper–immunoglobulin E levels, eczema, and greater susceptibility to cancer. Because natural killer T (NKT) cells have been implicated in these diseases, we asked if these cells were affected by DOCK8 deficiency. Using a mouse model, we found that DOCK8 deficiency resulted in impaired NKT cell development, principally affecting the formation and survival of long-lived, differentiated NKT cells. In the thymus, DOCK8-deficient mice lack a terminally differentiated subset of NK1.1+ NKT cells expressing the integrin CD103, whereas in the liver, DOCK8-deficient NKT cells express reduced levels of the prosurvival factor B-cell lymphoma 2 and the integrin lymphocyte function-associated antigen 1. Although the initial NKT cell response to antigen is intact in the absence of DOCK8, their ongoing proliferative and cytokine responses are impaired. Importantly, a similar defect in NKT cell numbers was detected in DOCK8-deficient humans, highlighting the relevance of the mouse model. In conclusion, our data demonstrate that DOCK8 is required for the development and survival of mature NKT cells, consistent with the idea that DOCK8 mediates survival signals within a specialized niche. Accordingly, impaired NKT cell numbers and function are likely to contribute to the susceptibility of DOCK8-deficient patients to recurrent infections and malignant disease. PMID:23929855

  9. STAT3 is a critical cell-intrinsic regulator of human unconventional T cell numbers and function

    Science.gov (United States)

    Wilson, Robert P.; Ives, Megan L.; Rao, Geetha; Lau, Anthony; Payne, Kathryn; Kobayashi, Masao; Arkwright, Peter D.; Peake, Jane; Wong, Melanie; Adelstein, Stephen; Smart, Joanne M.; French, Martyn A.; Fulcher, David A.; Picard, Capucine; Bustamante, Jacinta; Boisson-Dupuis, Stephanie; Gray, Paul; Stepensky, Polina; Warnatz, Klaus; Freeman, Alexandra F.; Rossjohn, Jamie; McCluskey, James; Holland, Steven M.; Casanova, Jean-Laurent; Uzel, Gulbu; Ma, Cindy S.

    2015-01-01

    Unconventional T cells such as γδ T cells, natural killer T cells (NKT cells) and mucosal-associated invariant T cells (MAIT cells) are a major component of the immune system; however, the cytokine signaling pathways that control their development and function in humans are unknown. Primary immunodeficiencies caused by single gene mutations provide a unique opportunity to investigate the role of specific molecules in regulating human lymphocyte development and function. We found that individuals with loss-of-function mutations in STAT3 had reduced numbers of peripheral blood MAIT and NKT but not γδ T cells. Analysis of STAT3 mosaic individuals revealed that this effect was cell intrinsic. Surprisingly, the residual STAT3-deficient MAIT cells expressed normal levels of the transcription factor RORγt. Despite this, they displayed a deficiency in secretion of IL-17A and IL-17F, but were able to secrete normal levels of cytokines such as IFNγ and TNF. The deficiency in MAIT and NKT cells in STAT3-deficient patients was mirrored by loss-of-function mutations in IL12RB1 and IL21R, respectively. Thus, these results reveal for the first time the essential role of STAT3 signaling downstream of IL-23R and IL-21R in controlling human MAIT and NKT cell numbers. PMID:25941256

  10. Criticality in cell differentiation

    Indian Academy of Sciences (India)

    The differentiation dynamics have both deterministic andstochastic components. Several theoretical studies suggest that cell differentiation is a bifurcation phenomenon, well-knownin dynamical systems theory. The bifurcation point has the character of a critical point with the system dynamics exhibitingspecific features in its ...

  11. A Critical Function of Mad2l2 in Primordial Germ Cell Development of Mice

    Science.gov (United States)

    Pirouz, Mehdi; Pilarski, Sven; Kessel, Michael

    2013-01-01

    The development of primordial germ cells (PGCs) involves several waves of epigenetic reprogramming. A major step is following specification and involves the transition from the stably suppressive histone modification H3K9me2 to the more flexible, still repressive H3K27me3, while PGCs are arrested in G2 phase of their cycle. The significance and underlying molecular mechanism of this transition were so far unknown. Here, we generated mutant mice for the Mad2l2 (Mad2B, Rev7) gene product, and found that they are infertile in both males and females. We demonstrated that Mad2l2 is essential for PGC, but not somatic development. PGCs were specified normally in Mad2l2−/− embryos, but became eliminated by apoptosis during the subsequent phase of epigenetic reprogramming. A majority of knockout PGCs failed to arrest in the G2 phase, and did not switch from a H3K9me2 to a H3K27me3 configuration. By the analysis of transfected fibroblasts we found that the interaction of Mad2l2 with the histone methyltransferases G9a and GLP lead to a downregulation of H3K9me2. The inhibitory binding of Mad2l2 to Cyclin dependent kinase 1 (Cdk1) could arrest the cell cycle in the G2 phase, and also allowed another histone methyltransferase, Ezh2, to upregulate H3K27me3. Together, these results demonstrate the potential of Mad2l2 in the regulation of both cell cycle and the epigenetic status. The function of Mad2l2 is essential in PGCs, and thus of high relevance for fertility. PMID:24009519

  12. SIRT6-mediated transcriptional suppression of Txnip is critical for pancreatic beta cell function and survival in mice.

    Science.gov (United States)

    Qin, Kunhua; Zhang, Ning; Zhang, Zhao; Nipper, Michael; Zhu, Zhenxin; Leighton, Jake; Xu, Kexin; Musi, Nicolas; Wang, Pei

    2018-04-01

    Better understanding of how genetic and epigenetic components control beta cell differentiation and function is key to the discovery of novel therapeutic approaches to prevent beta cell dysfunction and failure in the progression of type 2 diabetes. Our goal was to elucidate the role of histone deacetylase sirtuin 6 (SIRT6) in beta cell development and homeostasis. Sirt6 endocrine progenitor cell conditional knockout and beta cell-specific knockout mice were generated using the Cre-loxP system. Mice were assayed for islet morphology, glucose tolerance, glucose-stimulated insulin secretion and susceptibility to streptozotocin. Transcriptional regulatory functions of SIRT6 in primary islets were evaluated by RNA-Seq analysis. Reverse transcription-quantitative (RT-q)PCR and immunoblot were used to verify and investigate the gene expression changes. Chromatin occupancies of SIRT6, H3K9Ac, H3K56Ac and active RNA polymerase II were evaluated by chromatin immunoprecipitation. Deletion of Sirt6 in pancreatic endocrine progenitor cells did not affect endocrine morphology, beta cell mass or insulin production but did result in glucose intolerance and defective glucose-stimulated insulin secretion in mice. Conditional deletion of Sirt6 in adult beta cells reproduced the insulin secretion defect. Loss of Sirt6 resulted in aberrant upregulation of thioredoxin-interacting protein (TXNIP) in beta cells. SIRT6 deficiency led to increased acetylation of histone H3 lysine residue at 9 (H3K9Ac), acetylation of histone H3 lysine residue at 56 (H3K56Ac) and active RNA polymerase II at the promoter region of Txnip. SIRT6-deficient beta cells exhibited a time-dependent increase in H3K9Ac, H3K56Ac and TXNIP levels. Finally, beta cell-specific SIRT6-deficient mice showed increased sensitivity to streptozotocin. Our results reveal that SIRT6 suppresses Txnip expression in beta cells via deacetylation of histone H3 and plays a critical role in maintaining beta cell function and viability

  13. Divisors, measures and critical functions

    Indian Academy of Sciences (India)

    obtained by Popescu et al [5]. Keywords. Trace function; divisors; minimal polynomial; critical function. .... In §5 we define the critical function associated to divisors with compact support. We show in Theorem 5.5 that ...... Remark 5.6. Based on Remark 4.4 one might think that Theorem 5.5 is weaker than. Theorem 1.11 in [5].

  14. A critical assessment of the use of microculture tetrazolium assays to measure cell growth and function.

    Science.gov (United States)

    Marshall, N J; Goodwin, C J; Holt, S J

    1995-06-01

    Microculture tetrazolium assays (MTAs) are being widely applied to probe the relationships between cell survival, growth, and differentiation and also to investigate associations between compromised cell metabolism, oxidative stress, and programmed cell death as occurs in apoptosis. MTAs rely upon the cellular reduction of tetrazolium salts to their intensely coloured formazans. The resulting colorimetric assays form the basis of exceptionally precise systems which are technically amenable and capable of a high throughput of samples. As a consequence, MTAs are being used to monitor responses to both extracellular activators and toxic agents in disciplines as diverse as radiobiology and endocrinology. We review the chemistry and histochemical applications of tetrazolium salts and subsequently discuss the criteria for their use in MTAs. These assays are one of the latest examples of the application of the tetrazolium/formazan system to cell biology. We outline current views on the mechanisms of the bioreduction of tetrazolium salts. These probably combine to reflect the integrated pyridine nucleotide dependent redox state of the cell. We try to illustrate how an understanding of these mechanisms helps to avoid some of the pitfalls of the MTA systems. There is now for example, extensive evidence that changes in cell culture environments, such as glucose supply or pH of the medium, influence the reduction of tetrazolium salts and thereby introduce artefacts into MTAs. Finally, we provide examples of situations in which MTAs can be used to complement other more established experimental systems. They then act as unique probes with which to investigate changes in the redox state of the cell. These changes are associated with regulation of cell growth, proliferation and differentiation and conversely, the different pathways leading to cell death.

  15. Critical function of AP-2gamma/TCFAP2C in mouse embryonic germ cell maintenance

    NARCIS (Netherlands)

    S. Weber (Susanne); D. Eckert (Dawid); D. Nettersheim (Daniel); A.J.M. Gillis (Ad); S. Schäfer (Sabine); P. Kuckenberg (Peter); J. Ehlermann (Julia); U. Werling (Uwe); K. Biermann (Katharina); L.H.J. Looijenga (Leendert); H. Schorle (Hubert)

    2010-01-01

    textabstractFormation of the germ cell lineage involves multiple processes, including repression of somatic differentiation and reacquisition of pluripotency as well as a unique epigenetic constitution. The transcriptional regulator Prdm1 has been identified as a main coordinator of this process,

  16. Critical Function of PRDM2 in the Neoplastic Growth of Testicular Germ Cell Tumors

    Directory of Open Access Journals (Sweden)

    Erika Di Zazzo

    2016-12-01

    Full Text Available Testicular germ cell tumors (TGCTs derive from primordial germ cells. Their maturation is blocked at different stages, reflecting histological tumor subtypes. A common genetic alteration in TGCT is a deletion of the chromosome 1 short arm, where the PRDM2 gene, belonging to the Positive Regulatory domain gene (PRDM family, is located. Expression of PRDM2 gene is shifted in different human tumors, where the expression of the two principal protein forms coded by PRDM2 gene, RIZ1 and RIZ2, is frequently unbalanced. Therefore, PRDM2 is actually considered a candidate tumor suppressor gene in different types of cancer. Although recent studies have demonstrated that PRDM gene family members have a pivotal role during the early stages of testicular development, no information are actually available on the involvement of these genes in TGCTs. In this article we show by qRT-PCR analysis that PRDM2 expression level is modulated by proliferation and differentiation agents such as estradiol, whose exposure during fetal life is probably an important risk factor for TGCTs development in adulthood. Furthermore in normal and cancer germ cell lines, PRDM2 binds estradiol receptor α (ERα and influences proliferation, survival and apoptosis, as previously reported using MCF-7 breast cancer cell line, suggesting a potential tumor-suppressor role in TGCT formation.

  17. Thyroid function during critical illness.

    Science.gov (United States)

    Economidou, Foteini; Douka, Evangelia; Tzanela, Marinella; Nanas, Serafeim; Kotanidou, Anastasia

    2011-01-01

    The metabolic support of the critically ill patient is a relatively new target of active research and little is as yet known about the effects of critical illness on metabolism. The nonthyroidal illness syndrome, also known as the low T3 syndrome or euthyroid sick syndrome, describes a condition characterized by abnormal thyroid function tests encountered in patients with acute or chronic systemic illnesses. The laboratory parameters of this syndrome include low serum levels of triiodothyronine (T3) and high levels of reverse T3, with normal or low levels of thyroxine (T4) and normal or low levels of thyroid-stimulating hormone (TSH). This condition may affect 60 to 70% of critically ill patients. The changes in serum thyroid hormone levels in the critically ill patient seem to result from alterations in the peripheral metabolism of the thyroid hormones, in TSH regulation, in the binding of thyroid hormone to transport-protein and in receptor binding and intracellular uptake. Medications also have a very important role in these alterations. Hormonal changes can be seen within the first hours of critical illness and, interestingly, these changes correlate with final outcome. Data on the beneficial effect of thyroid hormone treatment on outcome in critically ill patients are so far controversial. Thyroid function generally returns to normal as the acute illness resolves.

  18. Divisors, measures and critical functions

    Indian Academy of Sciences (India)

    In [4] we have introduced a new distance between Galois orbits over Q Q . Using generalized divisors, we have extended the notion of trace of an algebraic number to other transcendental quantities. In this article we continue the work started in [4]. We define the critical function for a class of transcendental numbers, that ...

  19. Criticality in cell differentiation

    Indian Academy of Sciences (India)

    Indrani Bose

    2017-11-09

    Nov 9, 2017 ... Cell differentiation is an important process in living organisms. Differentiation is mostly based on binary decisions with the progenitor cells choosing between two specific lineages. The differentiation dynamics have both deterministic and stochastic components. Several theoretical studies suggest that cell ...

  20. Criticality in cell differentiation

    Indian Academy of Sciences (India)

    Cell differentiation is an important process in living organisms. Differentiation is mostly based on binary decisions with theprogenitor cells choosing between two specific lineages. The differentiation dynamics have both deterministic andstochastic components. Several theoretical studies suggest that cell differentiation is a ...

  1. Dipeptidyl peptidase-4 inhibitors and preservation of pancreatic islet-cell function: a critical appraisal of the evidence

    NARCIS (Netherlands)

    van Genugten, R.E.; van Raalte, D.H.; Diamant, M.

    2012-01-01

    Type 2 diabetes mellitus (T2DM) develops as a consequence of progressive β-cell dysfunction in the presence of insulin resistance. None of the currently-available T2DM therapies is able to change the course of the disease by halting the relentless decline in pancreatic islet cell function. Recently,

  2. Critical Roles of Reactive Oxygen Species in Age-Related Impairment in Ischemia-Induced Neovascularization by Regulating Stem and Progenitor Cell Function

    Directory of Open Access Journals (Sweden)

    Yuen Ting Lam

    2016-01-01

    Full Text Available Reactive oxygen species (ROS regulate bone marrow microenvironment for stem and progenitor cells functions including self-renewal, differentiation, and cell senescence. In response to ischemia, ROS also play a critical role in mediating the mobilization of endothelial progenitor cells (EPCs from the bone marrow to the sites of ischemic injury, which contributes to postnatal neovascularization. Aging is an unavoidable biological deteriorative process with a progressive decline in physiological functions. It is associated with increased oxidative stress and impaired ischemia-induced neovascularization. This review discusses the roles of ROS in regulating stem and progenitor cell function, highlighting the impact of unbalanced ROS levels on EPC dysfunction and the association with age-related impairment in ischemia-induced neovascularization. Furthermore, it discusses strategies that modulate the oxidative levels of stem and progenitor cells to enhance the therapeutic potential for elderly patients with cardiovascular disease.

  3. mTOR plays critical roles in pancreatic cancer stem cells through specific and stemness-related functions

    OpenAIRE

    Matsubara, Shyuichiro; Ding, Qiang; Miyazaki, Yumi; Kuwahata, Taisaku; Tsukasa, Koichiro; Takao, Sonshin

    2013-01-01

    "Pancreatic cancer is characterized by near-universal mutations in KRAS. The mammalian target of rapamycin (mTOR), which functions downstream of RAS, has divergent effects on stem cells. In the present study, we investigated the significance of the mTOR pathway in maintaining the properties of pancreatic cancer stem cells. The mTOR inhibitor, rapamycin, reduced the viability of CD133+ pancreatic cancer cells and sphere formation which is an index of self-renewal of stem-like cells, indicating...

  4. Critical function monitoring system algorithm development

    International Nuclear Information System (INIS)

    Harmon, D.L.

    1984-01-01

    Accurate critical function status information is a key to operator decision-making during events threatening nuclear power plant safety. The Critical Function Monitoring System provides continuous critical function status monitoring by use of algorithms which mathematically represent the processes by which an operating staff would determine critical function status. This paper discusses in detail the systematic design methodology employed to develop adequate Critical Function Monitoring System algorithms

  5. Criticality in cell differentiation

    Indian Academy of Sciences (India)

    Indrani Bose

    2017-11-09

    Nov 9, 2017 ... diverse as ecosystems, financial markets, population biology and complex diseases (Scheffer et al. 2009, 2012). Similar studies on the signatures of regime .... and in the maintenance of homeostasis in adult tissues. (Semrau and van Oudenaarden 2015). Cell differentiation occurs when the undifferentiated ...

  6. Functional cross-talk between the cellular prion protein and the neural cell adhesion molecule is critical for neuronal differentiation of neural stem/precursor cells.

    Science.gov (United States)

    Prodromidou, Kanella; Papastefanaki, Florentia; Sklaviadis, Theodoros; Matsas, Rebecca

    2014-06-01

    Cellular prion protein (PrP) is prominently expressed in brain, in differentiated neurons but also in neural stem/precursor cells (NPCs). The misfolding of PrP is a central event in prion diseases, yet the physiological function of PrP is insufficiently understood. Although PrP has been reported to associate with the neural cell adhesion molecule (NCAM), the consequences of concerted PrP-NCAM action in NPC physiology are unknown. Here, we generated NPCs from the subventricular zone (SVZ) of postnatal day 5 wild-type and PrP null (-/-) mice and observed that PrP is essential for proper NPC proliferation and neuronal differentiation. Moreover, we found that PrP is required for the NPC response to NCAM-induced neuronal differentiation. In the absence of PrP, NCAM not only fails to promote neuronal differentiation but also induces an accumulation of doublecortin-positive neuronal progenitors at the proliferation stage. In agreement, we noted an increase in cycling neuronal progenitors in the SVZ of PrP-/- mice compared with PrP+/+ mice, as evidenced by double labeling for the proliferation marker Ki67 and doublecortin as well as by 5-bromo-2'-deoxyuridine incorporation experiments. Additionally, fewer newly born neurons were detected in the rostral migratory stream of PrP-/- mice. Analysis of the migration of SVZ cells in microexplant cultures from wild-type and PrP-/- mice revealed no differences between genotypes or a role for NCAM in this process. Our data demonstrate that PrP plays a critical role in neuronal differentiation of NPCs and suggest that this function is, at least in part, NCAM-dependent. © 2014 AlphaMed Press.

  7. Complications impaired endothelial progenitor cell function in Type 2 diabetic patients with or without critical leg ischaemia: implication for impaired neovascularization in diabetes.

    Science.gov (United States)

    Chen, M-C; Sheu, J-J; Wang, P-W; Chen, C-Y; Kuo, M-C; Hsieh, C-J; Chen, J-F; Chang, H-W

    2009-02-01

    This study tested the hypothesis that migratory function of endothelial progenitor cells (EPCs) is impaired in Type 2 diabetic patients with or without critical leg ischaemia. Seventy-four patients were classified into four groups: Type 2 diabetic (n = 21) and non-diabetic patients (n = 10) with critical leg ischaemia and Type 2 diabetic patients without lower extremity vascular disease (n = 30) and healthy subjects (n = 13). The number and functional activity of circulating and cultured EPCs were determined. The migratory function of cultured EPCs was significantly impaired in diabetic patients without (median, 48, interquartile range, 46, 49 count/view/well) and with (median, 51, interquartile range, 46, 60 count/view/well) critical leg ischaemia and non-diabetic patients with critical leg ischaemia (median, 49, interquartile range, 47, 55 count/view/well) compared with healthy subjects (median, 63, interquartile range, 57, 65 count/view/well) (P interquartile range, 1600, 6600/10(6) cytometric events) than Type 2 diabetic patients with critical leg ischaemia (median, 5300, interquartile range, 2400, 11,100/10(6) cytometric events), non-diabetic patients with critical leg ischaemia (median, 5550, interquartile range, 2000, 32,100/10(6) cytometric events) and healthy subjects (median, 5400, interquartile range, 2700, 8700/10(6) cytometric events) (P = 0.413). The migratory function of EPCs is impaired in patients with Type 2 diabetes, even in those without critical leg ischaemia. These findings present an important new insight into the pathogenesis of impaired neovascularization and critical limb ischaemia in diabetic patients and provide avenues of future clinical study.

  8. Aryl Hydrocarbon Receptor Antagonists Mitigate the Effects of Dioxin on Critical Cellular Functions in Differentiating Human Osteoblast-Like Cells

    Directory of Open Access Journals (Sweden)

    Chawon Yun

    2018-01-01

    Full Text Available The inhibition of bone healing in humans is a well-established effect associated with cigarette smoking, but the underlying mechanisms are still unclear. Recent work using animal cell lines have implicated the aryl hydrocarbon receptor (AhR as a mediator of the anti-osteogenic effects of cigarette smoke, but the complexity of cigarette smoke mixtures makes understanding the mechanisms of action a major challenge. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, dioxin is a high-affinity AhR ligand that is frequently used to investigate biological processes impacted by AhR activation. Since there are dozens of AhR ligands present in cigarette smoke, we utilized dioxin as a prototype ligand to activate the receptor and explore its effects on pro-osteogenic biomarkers and other factors critical to osteogenesis using a human osteoblast-like cell line. We also explored the capacity for AhR antagonists to protect against dioxin action in this context. We found dioxin to inhibit osteogenic differentiation, whereas co-treatment with various AhR antagonists protected against dioxin action. Dioxin also negatively impacted cell adhesion with a corresponding reduction in the expression of integrin and cadherin proteins, which are known to be involved in this process. Similarly, the dioxin-mediated inhibition of cell migration correlated with reduced expression of the chemokine receptor CXCR4 and its ligand, CXCL12, and co-treatment with antagonists restored migratory capacity. Our results suggest that AhR activation may play a role in the bone regenerative response in humans exposed to AhR activators, such as those present in cigarette smoke. Given the similarity of our results using a human cell line to previous work done in murine cells, animal models may yield data relevant to the human setting. In addition, the AhR may represent a potential therapeutic target for orthopedic patients who smoke cigarettes, or those who are exposed to secondhand smoke or other

  9. Deafness in Claudin 11-Null Mice Reveals the Critical Contribution of Basal Cell Tight Junctions to Stria Vascularis Function

    Science.gov (United States)

    Gow, Alexander; Davies, Caroline; Southwood, Cherie M.; Frolenkov, Gregory; Chrustowski, Mark; Ng, Lily; Yamauchi, Daisuke; Marcus, Daniel C.; Kachar, Bechara

    2015-01-01

    Generation of a strong electrical potential in the cochlea is uniquely mammalian and may reflect recent evolutionary advances in cellular voltage-dependent amplifiers. This endocochlear potential is hypothesized to dramatically improve hearing sensitivity, a concept that is difficult to explore experimentally, because manipulating cochlear function frequently causes rapid degenerative changes early in development. Here, we examine the deafness phenotype in adult Claudin 11-null mice, which lack the basal cell tight junctions that give rise to the intrastrial compartment and find little evidence of cochlear pathology. Potassium ion recycling is normal in these mutants, but endocochlear potentials were below 30 mV and hearing thresholds were elevated 50 dB sound pressure level across the frequency spectrum. Together, these data demonstrate the central importance of basal cell tight junctions in the stria vascularis and directly verify the two-cell hypothesis for generation of endocochlear potential. Furthermore, these data indicate that endocochlear potential is an essential component of the power source for the mammalian cochlear amplifier. PMID:15306639

  10. Dictionary criticism and lexicographical function theory

    DEFF Research Database (Denmark)

    Tarp, Sven

    2017-01-01

    This contribution discusses dictionary criticism in the light of the function theory. It starts analyzing the objective of dictionary criticism and lists eight of the most important purposes with which criticism has been made by supporters of the function theory. It then discusses the two main...... types of dictionary criticism, namely criticism of other authors’ dictionaries and self-criticism of one’s own dictionaries. Based on this discussion, it proceeds to a definition of the concept of dictionary criticism which is above all considered a theory-based activity, the outcome of which may...... by the supporters of the function theory, and the way it could be presented in order to create debate. Finally, the contribution indicates the important role dictionary criticism has had in the development of the function theory and endorses an open and critical discussion culture within lexicography....

  11. Mast Cell Function

    Science.gov (United States)

    da Silva, Elaine Zayas Marcelino; Jamur, Maria Célia

    2014-01-01

    Since first described by Paul Ehrlich in 1878, mast cells have been mostly viewed as effectors of allergy. It has been only in the past two decades that mast cells have gained recognition for their involvement in other physiological and pathological processes. Mast cells have a widespread distribution and are found predominantly at the interface between the host and the external environment. Mast cell maturation, phenotype and function are a direct consequence of the local microenvironment and have a marked influence on their ability to specifically recognize and respond to various stimuli through the release of an array of biologically active mediators. These features enable mast cells to act as both first responders in harmful situations as well as to respond to changes in their environment by communicating with a variety of other cells implicated in physiological and immunological responses. Therefore, the critical role of mast cells in both innate and adaptive immunity, including immune tolerance, has gained increased prominence. Conversely, mast cell dysfunction has pointed to these cells as the main offenders in several chronic allergic/inflammatory disorders, cancer and autoimmune diseases. This review summarizes the current knowledge of mast cell function in both normal and pathological conditions with regards to their regulation, phenotype and role. PMID:25062998

  12. Critical biological parameters modulate affinity as a determinant of function in T-cell receptor gene-modified T-cells.

    Science.gov (United States)

    Spear, Timothy T; Wang, Yuan; Foley, Kendra C; Murray, David C; Scurti, Gina M; Simms, Patricia E; Garrett-Mayer, Elizabeth; Hellman, Lance M; Baker, Brian M; Nishimura, Michael I

    2017-11-01

    T-cell receptor (TCR)-pMHC affinity has been generally accepted to be the most important factor dictating antigen recognition in gene-modified T-cells. As such, there is great interest in optimizing TCR-based immunotherapies by enhancing TCR affinity to augment the therapeutic benefit of TCR gene-modified T-cells in cancer patients. However, recent clinical trials using affinity-enhanced TCRs in adoptive cell transfer (ACT) have observed unintended and serious adverse events, including death, attributed to unpredicted off-tumor or off-target cross-reactivity. It is critical to re-evaluate the importance of other biophysical, structural, or cellular factors that drive the reactivity of TCR gene-modified T-cells. Using a model for altered antigen recognition, we determined how TCR-pMHC affinity influenced the reactivity of hepatitis C virus (HCV) TCR gene-modified T-cells against a panel of naturally occurring HCV peptides and HCV-expressing tumor targets. The impact of other factors, such as TCR-pMHC stabilization and signaling contributions by the CD8 co-receptor, as well as antigen and TCR density were also evaluated. We found that changes in TCR-pMHC affinity did not always predict or dictate IFNγ release or degranulation by TCR gene-modified T-cells, suggesting that less emphasis might need to be placed on TCR-pMHC affinity as a means of predicting or augmenting the therapeutic potential of TCR gene-modified T-cells used in ACT. A more complete understanding of antigen recognition by gene-modified T-cells and a more rational approach to improve the design and implementation of novel TCR-based immunotherapies is necessary to enhance efficacy and maximize safety in patients.

  13. Type I interferon is critical for the homeostasis and functional maturation of type 3 γδ T cells

    DEFF Research Database (Denmark)

    Agerholm, Rasmus; Kadekar, Darshana Dattatraya; Rizk, John

    2017-01-01

    Type I IFN (IFN-I) is highly expressed during viral infection and many autoimmune pathologies such as SLE and psoriasis. In addition, IFN-I is important to maintain the homeostasis of a number of different immune populations. Our aim was to identify whether IFN-I regulates type 3 γδ T (γδT3) cells...... behavior. Such γδT3 anergy is characterized by failure to induce skin inflammation and unresponsiveness to cytokine stimuli. Moreover, IFNAR deficient mice display deregulated γδT3homeostasis due to a neonatal maturation defect. In conclusion, our data show that tonic type I IFN signaling during neonatal...

  14. A critical role for transcription factor Smad4 in T cell function that is independent of transforming growth factor β receptor signaling.

    Science.gov (United States)

    Gu, Ai-Di; Zhang, Song; Wang, Yunqi; Xiong, Hui; Curtis, Thomas A; Wan, Yisong Y

    2015-01-20

    Transforming growth factor-beta (TGF-β) suppresses T cell function to maintain self-tolerance and to promote tumor immune evasion. Yet how Smad4, a transcription factor component of TGF-β signaling, regulates T cell function remains unclear. Here we have demonstrated an essential role for Smad4 in promoting T cell function during autoimmunity and anti-tumor immunity. Smad4 deletion rescued the lethal autoimmunity resulting from transforming growth factor-beta receptor (TGF-βR) deletion and compromised T-cell-mediated tumor rejection. Although Smad4 was dispensable for T cell generation, homeostasis, and effector function, it was essential for T cell proliferation after activation in vitro and in vivo. The transcription factor Myc was identified to mediate Smad4-controlled T cell proliferation. This study thus reveals a requirement of Smad4 for T-cell-mediated autoimmunity and tumor rejection, which is beyond the current paradigm. It highlights a TGF-βR-independent role for Smad4 in promoting T cell function, autoimmunity, and anti-tumor immunity. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. The Leydig Cell MEK/ERK Pathway Is Critical for Maintaining a Functional Population of Adult Leydig Cells and for Fertility

    Science.gov (United States)

    Yamashita, Soichi; Tai, Ping; Charron, Jean; Ko, CheMyong

    2011-01-01

    MAPK kinase (MEK)1 and MEK2 were deleted from Leydig cells by crossing Mek1f/f;Mek2−/− and Cyp17iCre mice. Primary cultures of Leydig cell from mice of the appropriate genotype (Mek1f/f;Mek2−/−;iCre+) show decreased, but still detectable, MEK1 expression and decreased or absent ERK1/2 phosphorylation when stimulated with epidermal growth factor, Kit ligand, cAMP, or human choriogonadotropin (hCG). The body or testicular weights of Mek1f/f;Mek2−/−;iCre+ mice are not significantly affected, but the testis have fewer Leydig cells. The Leydig cell hypoplasia is paralleled by decreased testicular expression of several Leydig cell markers, such as the lutropin receptor, steroidogenic acute regulatory protein, cholesterol side chain cleavage enzyme, 17α-hydroxylase, and estrogen sulfotransferase. The expression of Sertoli or germ cell markers, as well as the shape, size, and cellular composition of the seminiferous tubules, are not affected. cAMP accumulation in response to hCG stimulation in primary cultures of Leydig cells from Mek1f/f;Mek2−/−;iCre+ mice is normal, but basal testosterone and testosterone syntheses provoked by addition of hCG or a cAMP analog, or by addition of substrates such as 22-hydroxycholesterol or pregnenolone, are barely detectable. The Mek1f/f;Mek2−/−;iCre+ males show decreased intratesticular testosterone and display several signs of hypoandrogenemia, such as elevated serum LH, decreased expression of two renal androgen-responsive genes, and decreased seminal vesicle weight. Also, in spite of normal sperm number and motility, the Mek1f/f;Mek2−/−;iCre+ mice show reduced fertility. These studies show that deletion of MEK1/2 in Leydig cells results in Leydig cell hypoplasia, hypoandrogenemia, and reduced fertility. PMID:21527500

  16. Holographic correlation functions in Critical Gravity

    Science.gov (United States)

    Anastasiou, Giorgos; Olea, Rodrigo

    2017-11-01

    We compute the holographic stress tensor and the logarithmic energy-momentum tensor of Einstein-Weyl gravity at the critical point. This computation is carried out performing a holographic expansion in a bulk action supplemented by the Gauss-Bonnet term with a fixed coupling. The renormalization scheme defined by the addition of this topological term has the remarkable feature that all Einstein modes are identically cancelled both from the action and its variation. Thus, what remains comes from a nonvanishing Bach tensor, which accounts for non-Einstein modes associated to logarithmic terms which appear in the expansion of the metric. In particular, we compute the holographic 1-point functions for a generic boundary geometric source.

  17. Effects of "second-hand" smoke on structure and function of fibroblasts, cells that are critical for tissue repair and remodeling

    Directory of Open Access Journals (Sweden)

    Yadav Madhav

    2004-04-01

    Full Text Available Abstract Background It is known that "second-hand" cigarette smoke leads to abnormal tissue repair and remodelling but the cellular mechanisms involved in these adverse effects are not well understood. Fibroblasts play a major role in repair and remodelling. They orchestrate these processes by proliferating, migrating, and secreting proteins such as, cytokines, growth factors and extracellular matrix molecules. Therefore, we focus our studies on the effects of "second-hand" cigarette smoke on the structure and function of these cells. Results We used sidestream whole (SSW smoke, a major component of "second-hand" smoke, primary embryonic fibroblasts, cells that behave very much like wound fibroblasts, and a variety of cellular and molecular approaches. We show that doses of smoke similar to those found in tissues cause cytoskeletal changes in the fibroblasts that may lead to a decrease in cell migration. In addition, we also show that these levels of cigarette smoke stimulate an increase in cell survival that is reflected in an increase and/or activation of stress/survival proteins such as cIL-8, grp78, PKB/Akt, p53, and p21. We further show that SSW affects the endomembrane system and that this effect is also accomplished by nicotine alone. Conclusions Taken together, our results suggest that: (i SSW may delay wound repair because of the inability of the fibroblasts to migrate into the wounded area, leading to an accumulation of these cells at the edge of the wound, thus preventing the formation of the healing tissue; (ii the increase in cell survival coupled to the decrease in cell migration can lead to a build-up of connective tissue, thereby causing fibrosis and excess scarring.

  18. Safety Evaluation of Chinese Medicine Injections with a Cell Imaging-Based Multiparametric Assay Revealed a Critical Involvement of Mitochondrial Function in Hepatotoxicity

    Directory of Open Access Journals (Sweden)

    Meng Wang

    2015-01-01

    Full Text Available The safety of herbal medicine products has been a widespread concern due to their complex chemical nature and lack of proper evaluation methods. We have adapted a sensitive and reproducible multiparametric cell-based high-content analysis assay to evaluate the hepatic-safety of four Chinese medicine injections and validated it with classical animal-based toxicity assays. Our results suggested that the reported hepatotoxicity by one of the drugs, Fufangkushen injection, could be attributed at least in part to the interference of mitochondrial function in human HepG2 cells by some of its constituents. This method should be useful for both preclinical screen in a drug discovery program and postclinical evaluation of herbal medicine preparations.

  19. Critical telomerase activity for uncontrolled cell growth

    Science.gov (United States)

    Wesch, Neil L.; Burlock, Laura J.; Gooding, Robert J.

    2016-08-01

    The lengths of the telomere regions of chromosomes in a population of cells are modelled using a chemical master equation formalism, from which the evolution of the average number of cells of each telomere length is extracted. In particular, the role of the telomere-elongating enzyme telomerase on these dynamics is investigated. We show that for biologically relevant rates of cell birth and death, one finds a critical rate, R crit, of telomerase activity such that the total number of cells diverges. Further, R crit is similar in magnitude to the rates of mitosis and cell death. The possible relationship of this result to replicative immortality and its associated hallmark of cancer is discussed.

  20. Media Literacy Function in Critical Blogs

    Science.gov (United States)

    Fedorov, Alexander; Levitskaya, Anastasia

    2015-01-01

    The Internet is widely recognized as playing an important role in facilitating education on a range of issues, including media literacy. Analyzing the media critical activity of contemporary Russian bloggers, the authors of the article reveal the following reasons for popularity or, on the contrary, unpopularity of blogger's media criticism:…

  1. Media Literacy Function in Critical Blogs

    Directory of Open Access Journals (Sweden)

    Alexander Fedorov

    2015-04-01

    Full Text Available The Internet is widely recognized as playing an important role in facilitating education on a range of issues, including media literacy. Analyzing the media critical activity of contemporary Russian bloggers, the authors of the article reveal the following reasons for popularity or, on the contrary, unpopularity of blogger's media criticism: targeted orientation, emotional charge, entertainment nature, duration, interactiveness, multimedia mode, simplicity/complexity of the language of a media text, the level of conformity.

  2. The critical safety functions and plant operation

    International Nuclear Information System (INIS)

    Corcoran, W.R.; Church, J.F.; Porter, N.J.; Cross, M.T.; Guinn, W.M.

    1981-01-01

    The paper outlines the operator's role in nuclear safety and introduces the concept of ''safety functions''. Safety functions are a group of actions that prevent core melt or minimize radiation releases to the general public. They can be used to provide a hierarchy of practical plant protection that an operator should use. ''An accident identical to that at Three Mile Island is not going to happen again'', said the Rogovin investigators. The concepts put forward in this paper are intended to help the operator avoid serious consequence from the next unexpected threat. On the basis of the safety evaluation, the operator has three roles in assuring that the consequences of an event will be no worse than the predicted acceptable results. These three operator roles are: first, maintain plant setup in readiness to properly respond; second, operate the plant in a manner such that fewer, milder events minimize the frequency and the severity of adverse events; third, the operator needs to monitor the plant to verify that the safety functions are accomplished. The operator needs a systematic approach to mitigating the consequences of an event. The concept of ''safety function'' introduces that systematic approach and prevents a hierarchy of protection. If the operator has difficulty in identifying an event for any reason, the systematic safety function approach allows ones to accomplish the overall path of mitigating consequences. There are ten identified functions designed to protect against core melt, preserve containment integrity, prevent indirect release of radioactivity, and maintain vital auxiliaries needed to support the other safety functions. The paper describes in detail the operator's role and the safety functions, and provides many examples of the use of alternative success paths to accomplish the safety function

  3. Critical immunological pathways are downregulated in APECED patient dendritic cells.

    Science.gov (United States)

    Pöntynen, Nora; Strengell, Mari; Sillanpää, Niko; Saharinen, Juha; Ulmanen, Ismo; Julkunen, Ilkka; Peltonen, Leena

    2008-10-01

    Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a monogenic autoimmune disease caused by mutations in the autoimmune regulator (AIRE) gene. AIRE functions as a transcriptional regulator, and it has a central role in the development of immunological tolerance. AIRE regulates the expression of ectopic antigens in epithelial cells of the thymic medulla and has been shown to participate in the development of peripheral tolerance. However, the mechanism of action of AIRE has remained elusive. To further investigate the role of AIRE in host immune functions, we studied the properties and transcript profiles in in vitro monocyte-differentiated dendritic cells (moDCs) obtained from APECED patients and healthy controls. AIRE-deficient monocytes showed typical DC morphology and expressed DC marker proteins cluster of differentiation 86 and human leukocyte antigen class II. APECED patient-derived moDCs were functionally impaired: the transcriptional response of cytokine genes to pathogens was drastically reduced. Interestingly, some changes were observable already at the immature DC stage. Pathway analyses of transcript profiles revealed that the expression of the components of the host cell signaling pathways involved in cell-cell signalling, innate immune responses, and cytokine activity were reduced in APECED moDCs. Our observations support a role for AIRE in peripheral tolerance and are the first ones to show that AIRE has a critical role in DC responses to microbial stimuli in humans.

  4. Critical Thinking, Executive Functions and Their Potential Relationship

    Science.gov (United States)

    Lizarraga, Maria Luisa Sanz de Acedo; Baquedano, Maria Teresa Sanz de Acedo; Villanueva, Oscar Ardaiz

    2012-01-01

    The central issue of this paper is to review the possible relationships between the constructs of critical thinking and executive functions. To do this, we first analyse the essential components of critical thinking from a psychological and neurological point of view. Second, we examine the scope of the cognitive and neurological nature of…

  5. Critical points of a perturbed Otha-Kawasaki functional

    OpenAIRE

    Rizzi, Matteo

    2016-01-01

    In the paper, we consider a small perturbation of the Otha-Kawasaki functional and we construct at least four critical points close to suitable translations of the Schwarz P surface with fixed volume.

  6. Off-critical local height probabilities on a plane and critical partition functions on a cylinder

    Directory of Open Access Journals (Sweden)

    Omar Foda

    2018-03-01

    Full Text Available We compute off-critical local height probabilities in regime-III restricted solid-on-solid models in a 4N-quadrant spiral geometry, with periodic boundary conditions in the angular direction, and fixed boundary conditions in the radial direction, as a function of N, the winding number of the spiral, and τ, the departure from criticality of the model, and observe that the result depends only on the product Nτ. In the limit N→1, τ→τ0, such that τ0 is finite, we recover the off-critical local height probability on a plane, τ0-away from criticality. In the limit N→∞, τ→0, such that Nτ=τ0 is finite, and following a conformal transformation, we obtain a critical partition function on a cylinder of aspect-ratio τ0. We conclude that the off-critical local height probability on a plane, τ0-away from criticality, is equal to a critical partition function on a cylinder of aspect-ratio τ0, in agreement with a result of Saleur and Bauer.

  7. Critical safety function guidelines for experimental fusion facilities

    International Nuclear Information System (INIS)

    Cadwallader, L.C.

    1989-01-01

    As fusion experiments proceed toward deuterium-tritium operation, more attention is being given to public safety. This paper presents the four classes of functions that fusion experiments must provide to assure safe, stable shutdown and retention of radionuclides. These functions are referred to as critical safety functions (CSFs). Selecting CSFs is an important step in probabilistic risk assessment (PRA). An example of CSF selection and usage for the Compact Ignition Tokamak (CIT) is also presented. 10 refs., 6 figs

  8. The Expansion of Criminal Control: A Critical to Feather Functions

    Directory of Open Access Journals (Sweden)

    Mariel Muraro

    2015-12-01

    Full Text Available This article aims to relate the theories of punishment, retributive and preventive, with the criminological discourse, and make brief notes about the negative theories and criticism of the sentence. The article begins by making a few notes on the mass incarceration of the phenomenon, then going to discuss and present the form of action of the police state. Then they present the theories of punishment under the critical perspective, and then work the two main critical theories of punishment, thus treating the position Prof. Eugenio Raúl Zaffaroni and Prof. Juarez Cirino dos Santos. These presentations and discussions have left the critical discourse, not taking our work as end revisit the theoretical construction of the functions of the pen, just to demonstrate how the discourse of shame built by criminal law legitimizes selective and violent actions of the penal system.

  9. Growth factor choice is critical for successful functionalization of nanoparticles

    Directory of Open Access Journals (Sweden)

    Josephine ePinkernelle

    2015-09-01

    Full Text Available Nanoparticles (NPs show new characteristics compared to the corresponding bulk material. These nanoscale properties make them interesting for various applications in biomedicine and life sciences. One field of application is the use of magnetic NPs to support regeneration in the nervous system. Drug delivery requires a functionalization of NPs with bio-functional molecules. In our study, we functionalized self-made PEI-coated iron oxide NPs with nerve growth factor (NGF and glial cell-line derived neurotrophic factor (GDNF. Next, we tested the bio-functionality of NGF in a rat pheochromocytoma cell line (PC12 and the bio-functionality of GDNF in an organotypic spinal cord culture. Covalent binding of NGF to PEI-NPs impaired bio-functionality of NGF, but non-covalent approach differentiated PC12 cells reliably. Non-covalent binding of GDNF showed a satisfying bio-functionality of GDNF:PEI-NPs, but turned out to be instable in conjugation to the PEI-NPs. Taken together, our study showed the importance of assessing bio-functionality and binding stability of functionalized growth factors using proper biological models. It also shows that successful functionalization of magnetic NPs with growth factors is dependent on the used binding chemistry and that it is hardly predictable. For use as therapeutics, functionalization strategies have to be reproducible and future studies are needed.

  10. A critical assessment of fuel cell technology

    International Nuclear Information System (INIS)

    Lindstroem, O.

    1994-01-01

    Cold combustion is a promised technology to mankind since the middle of the last century. The fuel cell may at last become the energy machine of the one to come after a long journey on a road bordered with expectations, successes and disappointments. Ten billion people will need the cell for their well-being. The progress and the state-of-art is assessed by means of figures of merit for performance, normalized to standard conditions, life and variability. State-of-art current densities for multi-kW stacks operating on atmospheric pressure air at 0.74 V cell voltage (50% efficiency, HHV) are estimated to be 150 mA/cm 2 for MCFC, 160 mA/cm 2 for AFC, 239 mA/cm 2 for PEFC and 270 mA/cm 2 for SOFC. PAFC gives 260 mA/cm 2 at 0.66 V and DMFC 100 mA/cm 2 at 0.37 V. Decay rates are about 1%/1000 h for PEFC, PAFC and SOFC compared to 2%/1000 h for AFC and 3%/1000 h for MCFC. Coefficients of variation for cell voltages amount to about 1% for all options, except for MCFC with 3-4%. Improvement of cell performance after 1975 is nil to moderate, except for SOFC with a consistent annual improvement of about 10%. There is room for further development of terrestrial AFCs towards 300-400 mA/cm 2 considering the figure 800 mA/cm 2 for oxygen AFCs. Life and cost will decide the future of the fuel cell. Prospects are not as good as they could be. The fuel cell community lacks understanding of the basics of fuel processing, as demonstrated by the widespread misbelief ('the CO 2 syndrome') that CO 2 cannot be removed cost effectively from a hydrogen feed (which is practiced in every NH 3 plant around the world). The competition, read the gas turbine, has to be taken very seriously. Emphasis has to be shifted from premature demonstrations to R and D on fundamental problems, which have been around too long. 34 refs

  11. NF-κB Essential MOdulator (NEMO) Is Critical for Thyroid Function

    OpenAIRE

    Reale, Carla; Iervolino, Anna; Scudiero, Ivan; Ferravante, Angela; Egildo D, Luca; Mazzone, Pellegrino; Zotti, Tiziana; Leonardi, Antonio; Roberto, Luca; Zannini, Mariastella; Cristofaro, Tiziana de; Shanmugakona, Muralitharan; Capasso, Giovambattista; Pasparakis, Manolis; Vito, Pasquale

    2016-01-01

    The I-?B kinase (IKK) subunit NEMO/IKK? (NEMO) is an adapter molecule that is critical for canonical activation of NF-?B, a pleiotropic transcription factor controlling immunity, differentiation, cell growth, tumorigenesis, and apoptosis. To explore the functional role of canonical NF-?B signaling in thyroid gland differentiation and function, we have generated a murine strain bearing a genetic deletion of the NEMO locus in thyroid. Here we show that thyrocyte-specific NEMO knock-out mice gra...

  12. Value-distribution of the Riemann zeta-function and related functions near the critical line

    OpenAIRE

    Christ, Thomas

    2013-01-01

    The Riemann zeta-function forms a central object in multiplicative number theory; its value-distribution encodes deep arithmetic properties of the prime numbers. Here, a crucial role is assigned to the analytic behavior of the zeta-function on the so called critical line. In this thesis we study the value-distribution of the Riemann zeta-function near and on the critical line. Amongst others we focus on the following. PART I: A modified concept of universality, a-points near the critical ...

  13. Diabetes and Stem Cell Function

    Directory of Open Access Journals (Sweden)

    Shin Fujimaki

    2015-01-01

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

  14. Critical role of bicarbonate and bicarbonate transporters in cardiac function

    OpenAIRE

    Wang, Hong-Sheng; Chen, Yamei; Vairamani, Kanimozhi; Shull, Gary E

    2014-01-01

    Bicarbonate is one of the major anions in mammalian tissues and extracellular fluids. Along with accompanying H+, HCO3- is generated from CO2 and H2O, either spontaneously or via the catalytic activity of carbonic anhydrase. It serves as a component of the major buffer system, thereby playing a critical role in pH homeostasis. Bicarbonate can also be utilized by a variety of ion transporters, often working in coupled systems, to transport other ions and organic substrates across cell membrane...

  15. Measurement of critical temperature as a function of field

    Science.gov (United States)

    McInturff, A. D.; Ishibashi, K.; Heard, G. D.

    The critical temperature has been measured for various magnet conductors as a function of the perpendicular applied magnetic field. The isothermal environment was provided by a variable temperature cryostat which fits into the bore of a 10 telsa solenoid. The temperature gradient across the sample volume was measured to be less than 25 millikelvins. The superconducting to normal state transition was measured resistively, using sample current densities from 0.01 to 2 A cm -2. The maximum applied magnetic field was 10 T and varied less than 0.5% in the sample volume. The critical transport current range of the samples measured from tens to thousands of amperes in the presence of a 10 T perpendicular magnetic field at 4.2 K.

  16. Critical role of NKT cells in posttransplant alloantibody production.

    Science.gov (United States)

    Zimmerer, J M; Swamy, P; Sanghavi, P B; Wright, C L; Abdel-Rasoul, M; Elzein, S M; Brutkiewicz, R R; Bumgardner, G L

    2014-11-01

    We previously reported that posttransplant alloantibody production in CD8-deficient hosts is IL-4+ CD4+ T cell-dependent and IgG1 isotype-dominant. The current studies investigated the hypothesis that IL-4-producing natural killer T cells (NKT cells) contribute to maximal alloantibody production. To investigate this, alloantibody levels were examined in CD8-deficient WT, CD1d KO and Jα18 KO transplant recipients. We found that the magnitude of IgG1 alloantibody production was critically dependent on the presence of type I NKT cells, which are activated by day 1 posttransplant. Unexpectedly, type I NKT cell contribution to enhanced IgG1 alloantibody levels was interferon-γ-dependent and IL-4-independent. Cognate interactions between type I NKT and B cells alone do not stimulate alloantibody production. Instead, NKT cells appear to enhance maturation of IL-4+ CD4+ T cells. To our knowledge, this is the first report to substantiate a critical role for type I NKT cells in enhancing in vivo antibody production in response to endogenous antigenic stimuli. © Copyright 2014 The American Society of Transplantation and the American Society of Transplant Surgeons.

  17. Critical Zone Experimental Design to Assess Soil Processes and Function

    Science.gov (United States)

    Banwart, Steve

    2010-05-01

    Through unsustainable land use practices, mining, deforestation, urbanisation and degradation by industrial pollution, soil losses are now hypothesized to be much faster (100 times or more) than soil formation - with the consequence that soil has become a finite resource. The crucial challenge for the international research community is to understand the rates of processes that dictate soil mass stocks and their function within Earth's Critical Zone (CZ). The CZ is the environment where soils are formed, degrade and provide their essential ecosystem services. Key among these ecosystem services are food and fibre production, filtering, buffering and transformation of water, nutrients and contaminants, storage of carbon and maintaining biological habitat and genetic diversity. We have initiated a new research project to address the priority research areas identified in the European Union Soil Thematic Strategy and to contribute to the development of a global network of Critical Zone Observatories (CZO) committed to soil research. Our hypothesis is that the combined physical-chemical-biological structure of soil can be assessed from first-principles and the resulting soil functions can be quantified in process models that couple the formation and loss of soil stocks with descriptions of biodiversity and nutrient dynamics. The objectives of this research are to 1. Describe from 1st principles how soil structure influences processes and functions of soils, 2. Establish 4 European Critical Zone Observatories to link with established CZOs, 3. Develop a CZ Integrated Model of soil processes and function, 4. Create a GIS-based modelling framework to assess soil threats and mitigation at EU scale, 5. Quantify impacts of changing land use, climate and biodiversity on soil function and its value and 6. Form with international partners a global network of CZOs for soil research and deliver a programme of public outreach and research transfer on soil sustainability. The

  18. Critical survey on electrode aging in molten carbonate fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, K.

    1979-12-01

    To evaluate potential electrodes for molten carbonate fuel cells, we reviewed the literature pertaining to these cells and interviewed investigators working in fuel cell technology. In this critical survey, the effect of three electrode aging processes - corrosion or oxidation, sintering, and poisoning - on these potential fuel-cell electrodes is presented. It is concluded that anodes of stabilized nickel and cathodes of lithium-doped NiO are the most promising electrode materials for molten carbonate fuel cells, but that further research and development of these electrodes are needed. In particular, the effect of contaminants such as H/sub 2/S and HCl on the nickel anode must be investigated, and methods to improve the physical strength and to increase the conductivity of NiO cathodes must be explored. Recommendations are given on areas of applied electrode research that should accelerate the commercialization of the molten carbonate fuel cell. 153 references.

  19. Preliminary Design of Critical Function Monitoring System of PGSFR

    International Nuclear Information System (INIS)

    2015-01-01

    A PGSFR (Prototype Gen-IV Sodium-cooled Fast Reactor) is under development at Korea Atomic Energy Research Institute. A critical function monitoring system of the PGSFR is preliminarily studied. The functions of CFMS are to display critical plant variables related to the safety of the plant during normal and accident conditions and guide the operators corrective actions to keep the plant in a safe condition and mitigate the consequences of accidents. The minimal critical functions of the PGSFR are composed of reactivity control, reactor core cooling, reactor coolant system integrity, primary heat transfer system(PHTS) heat removal, sodium water reaction mitigation, radiation control and containment conditions. The variables and alarm legs of each critical function of the PGSFR are as follows; - Reactivity control: The variables of reactivity control function are power range neutron flux instrumentation, intermediate range neutron flux instrumentation, source range neutron flux instrumentation, and control rod bottom contacts. The alarm leg to display the reactivity controls consists of status of control drop malfunction, high post trip power and thermal reactivity addition. - Reactor core cooling: The variables are PHTS sodium level, hot pool temperature of PHTS, subassembly exit temperature, cold pool temperature of the PHTS, PHTS pump current, and PHTS pump breaker status. The alarm leg consists of high core delta temperature, low sodium level of the PHTS, high subassembly exit temperature, and low PHTS pump load. - Reactor coolant system integrity: The variables are PHTS sodium level, cover gas pressure, and safeguard vessel sodium level. The alarm leg is composed of low sodium level of PHTS, high cover gas pressure and high sodium level of the safety guard vessel. - PHTS heat removal: The variables are PHTS sodium level, hot pool temperature of PHTS, core exit temperature, cold pool temperature of the PHTS, flow rate of passive residual heat removal system

  20. The influence of resistance training on the critical power function & time to fatigue at critical power.

    Science.gov (United States)

    Bishop, D; Jenkins, D G

    1996-12-01

    The present study examined whether a six-week resistance training program would influence the critical power (CP) function, time to exhaustion (TE) at CP and/or peak oxygen uptake (VO2 peak). The CP function is believed to provide an index of endurance ability (CP given by the slope), and anaerobic work capacity (the y-intercept). Eight healthy, untrained males undertook lower-body resistance training (90 min/day, 3-4 times/wk) for six weeks; eight controls refrained from resistance or endurance training for the same period. Before and immediately following the training period, subjects completed three trials to determine their CP function, a test of VO2 peak, a one-repetition maximum (1-RM) leg press test and TE at their CP. Training significantly increased both 1-RM leg press (28.6%, P 0.05) were found. Changes in the y-intercept following resistance training were negatively correlated with changes in the CP (r = -0.94, p < 0.05, N = 8). The present data show that the y-intercept of the CP function is sensitive to, and modified by, six weeks of resistance training. Given that resistance training had no significant influence on CP, TE at CP or VO2 peak, the present study has also shown that six weeks of resistance training will not alter indices of endurance ability. The negative relationship between changes in the y-intercept and CP exposes a potential limitation of the linear CP function when evaluating changes in endurance ability following an intervention which significantly alters the y-intercept.

  1. ZFAT plays critical roles in peripheral T cell homeostasis and its T cell receptor-mediated response

    International Nuclear Information System (INIS)

    Doi, Keiko; Fujimoto, Takahiro; Okamura, Tadashi; Ogawa, Masahiro; Tanaka, Yoko; Mototani, Yasumasa; Goto, Motohito; Ota, Takeharu; Matsuzaki, Hiroshi; Kuroki, Masahide; Tsunoda, Toshiyuki; Sasazuki, Takehiko; Shirasawa, Senji

    2012-01-01

    Highlights: ► We generated Cd4-Cre-mediated T cell-specific Zfat-deficient mice. ► Zfat-deficiency leads to reduction in the number of the peripheral T cells. ► Impaired T cell receptor-mediated response in Zfat-deficient peripheral T cells. ► Decreased expression of IL-7Rα, IL-2Rα and IL-2 in Zfat-deficient peripheral T cells. ► Zfat plays critical roles in peripheral T cell homeostasis. -- Abstract: ZFAT, originally identified as a candidate susceptibility gene for autoimmune thyroid disease, has been reported to be involved in apoptosis, development and primitive hematopoiesis. Zfat is highly expressed in T- and B-cells in the lymphoid tissues, however, its physiological function in the immune system remains totally unknown. Here, we generated the T cell-specific Zfat-deficient mice and demonstrated that Zfat-deficiency leads to a remarkable reduction in the number of the peripheral T cells. Intriguingly, a reduced expression of IL-7Rα and the impaired responsiveness to IL-7 for the survival were observed in the Zfat-deficient T cells. Furthermore, a severe defect in proliferation and increased apoptosis in the Zfat-deficient T cells following T cell receptor (TCR) stimulation was observed with a reduced IL-2Rα expression as well as a reduced IL-2 production. Thus, our findings reveal that Zfat is a critical regulator in peripheral T cell homeostasis and its TCR-mediated response.

  2. Gold nanoparticles delivery in mammalian live cells: a critical review

    Directory of Open Access Journals (Sweden)

    Raphaël Lévy

    2010-02-01

    Full Text Available Functional nanomaterials have recently attracted strong interest from the biology community, not only as potential drug delivery vehicles or diagnostic tools, but also as optical nanomaterials. This is illustrated by the explosion of publications in the field with more than 2,000 publications in the last 2 years (4,000 papers since 2000; from ISI Web of Knowledge, ‘nanoparticle and cell’ hit. Such a publication boom in this novel interdisciplinary field has resulted in papers of unequal standard, partly because it is challenging to assemble the required expertise in chemistry, physics, and biology in a single team. As an extreme example, several papers published in physical chemistry journals claim intracellular delivery of nanoparticles, but show pictures of cells that are, to the expert biologist, evidently dead (and therefore permeable. To attain proper cellular applications using nanomaterials, it is critical not only to achieve efficient delivery in healthy cells, but also to control the intracellular availability and the fate of the nanomaterial. This is still an open challenge that will only be met by innovative delivery methods combined with rigorous and quantitative characterization of the uptake and the fate of the nanoparticles. This review mainly focuses on gold nanoparticles and discusses the various approaches to nanoparticle delivery, including surface chemical modifications and several methods used to facilitate cellular uptake and endosomal escape. We will also review the main detection methods and how their optimum use can inform about intracellular localization, efficiency of delivery, and integrity of the surface capping. Raphaël Lévy is a BBSRC David Phillips Research Fellow at the University of Liverpool. He graduated in Physics at the University Louis Pasteur in Strasbourg (France. In 2002, after a Master in Soft Condensed Matter Physics, he obtained a PhD in Physics at the University Louis Pasteur. He then moved to

  3. DLEU2, frequently deleted in malignancy, functions as a critical host gene of the cell cycle inhibitory microRNAs miR-15a and miR-16-1

    Energy Technology Data Exchange (ETDEWEB)

    Lerner, Mikael; Harada, Masako [Department of Oncology-Pathology, Cancercentrum Karolinska (CCK), Karolinska Institutet R8:03, 171 76 Stockholm (Sweden); Loven, Jakob [Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm (Sweden); Castro, Juan [Department of Oncology-Pathology, Cancercentrum Karolinska (CCK), Karolinska Institutet R8:03, 171 76 Stockholm (Sweden); Davis, Zadie; Oscier, David [Department of Pathology, Royal Bournemouth Hospital, Bournemouth (United Kingdom); Henriksson, Marie [Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm (Sweden); Sangfelt, Olle [Department of Oncology-Pathology, Cancercentrum Karolinska (CCK), Karolinska Institutet R8:03, 171 76 Stockholm (Sweden); Grander, Dan, E-mail: Dan.Grander@ki.se [Department of Oncology-Pathology, Cancercentrum Karolinska (CCK), Karolinska Institutet R8:03, 171 76 Stockholm (Sweden); Corcoran, Martin M. [Department of Oncology-Pathology, Cancercentrum Karolinska (CCK), Karolinska Institutet R8:03, 171 76 Stockholm (Sweden)

    2009-10-15

    The microRNAs miR-15a and miR-16-1 are downregulated in multiple tumor types and are frequently deleted in chronic lymphocytic leukemia (CLL), myeloma and mantle cell lymphoma. Despite their abundance in most cells the transcriptional regulation of miR-15a/16-1 remains unclear. Here we demonstrate that the putative tumor suppressor DLEU2 acts as a host gene of these microRNAs. Mature miR-15a/miR-16-1 are produced in a Drosha-dependent process from DLEU2 and binding of the Myc oncoprotein to two alterative DLEU2 promoters represses both the host gene transcript and levels of mature miR-15a/miR-16-1. In line with a functional role for DLEU2 in the expression of the microRNAs, the miR-15a/miR-16-1 locus is retained in four CLL cases that delete both promoters of this gene and expression analysis indicates that this leads to functional loss of mature miR-15a/16-1. We additionally show that DLEU2 negatively regulates the G1 Cyclins E1 and D1 through miR-15a/miR-16-1 and provide evidence that these oncoproteins are subject to miR-15a/miR-16-1-mediated repression under normal conditions. We also demonstrate that DLEU2 overexpression blocks cellular proliferation and inhibits the colony-forming ability of tumor cell lines in a miR-15a/miR-16-1-dependent way. Together the data illuminate how inactivation of DLEU2 promotes cell proliferation and tumor progression through functional loss of miR-15a/miR-16-1.

  4. A Critical Role for Cysteine 57 in the Biological Functions of Selenium Binding Protein-1.

    Science.gov (United States)

    Ying, Qi; Ansong, Emmanuel; Diamond, Alan M; Yang, Wancai

    2015-11-18

    The concentration of selenium-binding protein1 (SBP1) is often lower in tumors than in the corresponding tissue and lower levels have been associated with poor clinical outcomes. SBP1 binds tightly selenium although what role selenium plays in its biological functions remains unknown. Previous studies indicated that cysteine 57 is the most likely candidate amino acid for selenium binding. In order to investigate the role of cysteine 57 in SBP1, this amino acid was altered to a glycine and the mutated protein was expressed in human cancer cells. The SBP1 half-life, as well as the cellular response to selenite cytotoxicity, was altered by this change. The ectopic expression of SBP1(GLY) also caused mitochondrial damage in HCT116 cells. Taken together, these results indicated that cysteine 57 is a critical determinant of SBP1 function and may play a significant role in mitochondrial function.

  5. Is Cognitive Functioning Impaired in Methamphetamine Users? A Critical Review

    Science.gov (United States)

    Hart, Carl L; Marvin, Caroline B; Silver, Rae; Smith, Edward E

    2012-01-01

    The prevailing view is that recreational methamphetamine use causes a broad range of severe cognitive deficits, despite the fact that concerns have been raised about interpretations drawn from the published literature. This article addresses an important gap in our knowledge by providing a critical review of findings from recent research investigating the impact of recreational methamphetamine use on human cognition. Included in the discussion are findings from studies that have assessed the acute and long-term effects of methamphetamine on several domains of cognition, including visuospatial perception, attention, inhibition, working memory, long-term memory, and learning. In addition, relevant neuroimaging data are reviewed in an effort to better understand neural mechanisms underlying methamphetamine-related effects on cognitive functioning. In general, the data on acute effects show that methamphetamine improves cognitive performance in selected domains, that is, visuospatial perception, attention, and inhibition. Regarding long-term effects on cognitive performance and brain-imaging measures, statistically significant differences between methamphetamine users and control participants have been observed on a minority of measures. More importantly, however, the clinical significance of these findings may be limited because cognitive functioning overwhelmingly falls within the normal range when compared against normative data. In spite of these observations, there seems to be a propensity to interpret any cognitive and/or brain difference(s) as a clinically significant abnormality. The implications of this situation are multiple, with consequences for scientific research, substance-abuse treatment, and public policy. PMID:22089317

  6. Critical Thinking in a Higher Education Functional English Course

    Science.gov (United States)

    Khan, Shaista Irshad

    2017-01-01

    Critical thinking is seen as a highly desirable way of thinking that needs to be encouraged in all areas of higher education. However, it is not easy to conceptualise critical thinking in ways that can help in its development and in its assessment. Recent policy documents in Pakistan have laid emphasis on the development of critical thinking…

  7. EFFECT OF METHYL MERCURY CHLORIDE EXPOSURE ON PC12 CELL INTEGRIN EXPRESSION AND FUNCTION.

    Science.gov (United States)

    Integrins are heterodimeric transmembrane cell adhesion proteins composed of a and b protein subunits. They are important during brain development in a number of critical functions, including cell migration (Georges-Labouesse, et al., 1998), axonal elongation (Murase and Hayashi...

  8. Critical protein GAPDH and its regulatory mechanisms in cancer cells

    International Nuclear Information System (INIS)

    Zhang, Jin-Ying; Zhang, Fan; Hong, Chao-Qun; Giuliano, Armando E.; Cui, Xiao-Jiang; Zhou, Guang-Ji; Zhang, Guo-Jun; Cui, Yu-Kun

    2015-01-01

    Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), initially identified as a glycolytic enzyme and considered as a housekeeping gene, is widely used as an internal control in experiments on proteins, mRNA, and DNA. However, emerging evidence indicates that GAPDH is implicated in diverse functions independent of its role in energy metabolism; the expression status of GAPDH is also deregulated in various cancer cells. One of the most common effects of GAPDH is its inconsistent role in the determination of cancer cell fate. Furthermore, studies have described GAPDH as a regulator of cell death; other studies have suggested that GAPDH participates in tumor progression and serves as a new therapeutic target. However, related regulatory mechanisms of its numerous cellular functions and deregulated expression levels remain unclear. GAPDH is tightly regulated at transcriptional and posttranscriptional levels, which are involved in the regulation of diverse GAPDH functions. Several cancer-related factors, such as insulin, hypoxia inducible factor-1 (HIF-1), p53, nitric oxide (NO), and acetylated histone, not only modulate GAPDH gene expression but also affect protein functions via common pathways. Moreover, posttranslational modifications (PTMs) occurring in GAPDH in cancer cells result in new activities unrelated to the original glycolytic function of GAPDH. In this review, recent findings related to GAPDH transcriptional regulation and PTMs are summarized. Mechanisms and pathways involved in GAPDH regulation and its different roles in cancer cells are also described

  9. A conserved cysteine motif is critical for rice ceramide kinase activity and function.

    Directory of Open Access Journals (Sweden)

    Fang-Cheng Bi

    Full Text Available Ceramide kinase (CERK is a key regulator of cell survival in dicotyledonous plants and animals. Much less is known about the roles of CERK and ceramides in mediating cellular processes in monocot plants. Here, we report the characterization of a ceramide kinase, OsCERK, from rice (Oryza sativa spp. Japonica cv. Nipponbare and investigate the effects of ceramides on rice cell viability.OsCERK can complement the Arabidopsis CERK mutant acd5. Recombinant OsCERK has ceramide kinase activity with Michaelis-Menten kinetics and optimal activity at 7.0 pH and 40°C. Mg2+ activates OsCERK in a concentration-dependent manner. Importantly, a CXXXCXXC motif, conserved in all ceramide kinases and important for the activity of the human enzyme, is critical for OsCERK enzyme activity and in planta function. In a rice protoplast system, inhibition of CERK leads to cell death and the ratio of added ceramide and ceramide-1-phosphate, CERK's substrate and product, respectively, influences cell survival. Ceramide-induced rice cell death has apoptotic features and is an active process that requires both de novo protein synthesis and phosphorylation, respectively. Finally, mitochondria membrane potential loss previously associated with ceramide-induced cell death in Arabidopsis was also found in rice, but it occurred with different timing.OsCERK is a bona fide ceramide kinase with a functionally and evolutionarily conserved Cys-rich motif that plays an important role in modulating cell fate in plants. The vital function of the conserved motif in both human and rice CERKs suggests that the biochemical mechanism of CERKs is similar in animals and plants. Furthermore, ceramides induce cell death with similar features in monocot and dicot plants.

  10. [Signaling network-based functional cell design].

    Science.gov (United States)

    Ju, Jianqi; Wei, Ping

    2017-03-25

    Cellular signaling networks act as the central processor to deal with environmental signals and regulate cell function, and determine cell fate. Using synthetic biology approach to engineer cell signaling networks is crucial for ultimately constructing man-made "cell machines". Cellular signaling networks can encode sophisticated cell information by processing quantitatively signaling dynamics, which enables multi-dimensional regulation of functional sub-circuits. Here, we first review the research progresses on the signaling coding mechanisms; and then elaborate the methodologies and applications of cells signaling engineering; finally, we envision that signaling-based cell engineering are important for the increasingly-complicated next generation synthetic biology.

  11. Interpreting heterogeneity in intestinal tuft cell structure and function.

    Science.gov (United States)

    Banerjee, Amrita; McKinley, Eliot T; von Moltke, Jakob; Coffey, Robert J; Lau, Ken S

    2018-05-01

    Intestinal tuft cells are a morphologically unique cell type, best characterized by striking microvilli that form an apical tuft. These cells represent approximately 0.5% of gut epithelial cells depending on location. While they are known to express chemosensory receptors, their function has remained unclear. Recently, numerous groups have revealed startling insights into intestinal tuft cell biology. Here, we review the latest developments in understanding this peculiar cell type's structure and function. Recent advances in volumetric microscopy have begun to elucidate tuft cell ultrastructure with respect to its cellular neighbors. Moreover, single-cell approaches have revealed greater diversity in the tuft cell population than previously appreciated and uncovered novel markers to characterize this heterogeneity. Finally, advanced model systems have revealed tuft cells' roles in mucosal healing and orchestrating type 2 immunity against eukaryotic infection. While much remains unknown about intestinal tuft cells, these critical advances have illuminated the physiological importance of these previously understudied cells and provided experimentally tractable tools to interrogate this rare cell population. Tuft cells act as luminal sensors, linking the luminal microbiome to the host immune system, which may make them a potent clinical target for modulating host response to a variety of acute or chronic immune-driven conditions.

  12. Human CD8 T cells generated in vitro from hematopoietic stem cells are functionally mature

    Directory of Open Access Journals (Sweden)

    Zúñiga-Pflücker Juan

    2011-03-01

    Full Text Available Abstract Background T cell development occurs within the highly specialized thymus. Cytotoxic CD8 T cells are critical in adaptive immunity by targeting virally infected or tumor cells. In this study, we addressed whether functional CD8 T cells can be generated fully in vitro using human umbilical cord blood (UCB hematopoietic stem cells (HSCs in coculture with OP9-DL1 cells. Results HSC/OP9-DL1 cocultures supported the differentiation of CD8 T cells, which were TCR/CD3hi CD27hi CD1aneg and thus phenotypically resembled mature functional CD8 single positive thymocytes. These in vitro-generated T cells also appeared to be conventional CD8 cells, as they expressed high levels of Eomes and low levels of Plzf, albeit not identical to ex vivo UCB CD8 T cells. Consistent with the phenotypic and molecular characterization, upon TCR-stimulation, in vitro-generated CD8 T cells proliferated, expressed activation markers (MHC-II, CD25, CD38, secreted IFN-γ and expressed Granzyme B, a cytotoxic T-cell effector molecule. Conclusion Taken together, the ability to direct human hematopoietic stem cell or T-progenitor cells towards a mature functional phenotype raises the possibility of establishing cell-based treatments for T-immunodeficiencies by rapidly restoring CD8 effector function, thereby mitigating the risks associated with opportunistic infections.

  13. Revisiting the Functional Impact of NK Cells.

    Science.gov (United States)

    Poli, Aurélie; Michel, Tatiana; Patil, Neha; Zimmer, Jacques

    2018-02-26

    Immune responses are critical for the maintenance of homeostasis but can also upset the equilibrium, depending on the context and magnitude of the response. Natural killer (NK) cells are well known for their important roles in antiviral and antitumor immune responses, and they are currently used, mostly under optimized forms, as immunotherapeutic agents against cancer. Nevertheless, with accumulating examples of deleterious effects of NK cells, it is paramount to consider their negative contributions. Here, we critically review and comment on the literature surrounding undesirable aspects of NK cell activity, focusing on situations where they play a harmful rather than a protective role. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Cell Therapy in Patients with Critical Limb Ischemia

    Directory of Open Access Journals (Sweden)

    Rita Compagna

    2015-01-01

    Full Text Available Critical limb ischemia (CLI represents the most advanced stage of peripheral arterial obstructive disease (PAOD with a severe obstruction of the arteries which markedly reduces blood flow to the extremities and has progressed to the point of severe rest pain and/or even tissue loss. Recent therapeutic strategies have focused on restoring this balance in favor of tissue survival using exogenous molecular and cellular agents to promote regeneration of the vasculature. These are based on stimulation of angiogenesis by extracellular and cellular components. This review article carries out a systematic analysis of the most recent scientific literature on the application of stem cells in patients with CLI. The results obtained from the detailed analysis of the recent literature data have confirmed the beneficial role of cell therapy in reducing the rate of major amputations in patients with CLI and improving their quality of life.

  15. Rethinking platelet function: thrombocytopenia induced immunodeficiency in critical illness

    DEFF Research Database (Denmark)

    Ostrowski, Sisse R; Johansson, Per Ingemar

    2011-01-01

    traditional innate immune cells, platelets are recruited immediately into injured and inflamed tissue, they release immune mediators, express and shed immunologically active membrane receptors, they interact with other immune cells and they recognize and clear pathogens. We hypothesize that thrombocytopenia...

  16. ZFAT plays critical roles in peripheral T cell homeostasis and its T cell receptor-mediated response

    Energy Technology Data Exchange (ETDEWEB)

    Doi, Keiko [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan); Central Research Institute of Life Sciences for the Next Generation of Women Scientists, Fukuoka University, Fukuoka (Japan); Fujimoto, Takahiro [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan); Okamura, Tadashi [Division of Animal Models, Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo (Japan); Ogawa, Masahiro [Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan); Tanaka, Yoko [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Mototani, Yasumasa; Goto, Motohito [Division of Animal Models, Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo (Japan); Ota, Takeharu; Matsuzaki, Hiroshi [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Kuroki, Masahide [Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan); Tsunoda, Toshiyuki [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan); Sasazuki, Takehiko [Institute for Advanced Study, Kyushu University, Fukuoka (Japan); Shirasawa, Senji, E-mail: sshirasa@fukuoka-u.ac.jp [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan)

    2012-08-17

    Highlights: Black-Right-Pointing-Pointer We generated Cd4-Cre-mediated T cell-specific Zfat-deficient mice. Black-Right-Pointing-Pointer Zfat-deficiency leads to reduction in the number of the peripheral T cells. Black-Right-Pointing-Pointer Impaired T cell receptor-mediated response in Zfat-deficient peripheral T cells. Black-Right-Pointing-Pointer Decreased expression of IL-7R{alpha}, IL-2R{alpha} and IL-2 in Zfat-deficient peripheral T cells. Black-Right-Pointing-Pointer Zfat plays critical roles in peripheral T cell homeostasis. -- Abstract: ZFAT, originally identified as a candidate susceptibility gene for autoimmune thyroid disease, has been reported to be involved in apoptosis, development and primitive hematopoiesis. Zfat is highly expressed in T- and B-cells in the lymphoid tissues, however, its physiological function in the immune system remains totally unknown. Here, we generated the T cell-specific Zfat-deficient mice and demonstrated that Zfat-deficiency leads to a remarkable reduction in the number of the peripheral T cells. Intriguingly, a reduced expression of IL-7R{alpha} and the impaired responsiveness to IL-7 for the survival were observed in the Zfat-deficient T cells. Furthermore, a severe defect in proliferation and increased apoptosis in the Zfat-deficient T cells following T cell receptor (TCR) stimulation was observed with a reduced IL-2R{alpha} expression as well as a reduced IL-2 production. Thus, our findings reveal that Zfat is a critical regulator in peripheral T cell homeostasis and its TCR-mediated response.

  17. High Endothelial Venules and Other Blood Vessels: Critical Regulators of Lymphoid Organ Development and Function

    Science.gov (United States)

    Ager, Ann

    2017-01-01

    The blood vasculature regulates both the development and function of secondary lymphoid organs by providing a portal for entry of hemopoietic cells. During the development of lymphoid organs in the embryo, blood vessels deliver lymphoid tissue inducer cells that initiate and sustain the development of lymphoid tissues. In adults, the blood vessels are structurally distinct from those in other organs due to the requirement for high levels of lymphocyte recruitment under non-inflammatory conditions. In lymph nodes (LNs) and Peyer’s patches, high endothelial venules (HEVs) especially adapted for lymphocyte trafficking form a spatially organized network of blood vessels, which controls both the type of lymphocyte and the site of entry into lymphoid tissues. Uniquely, HEVs express vascular addressins that regulate lymphocyte entry into lymphoid organs and are, therefore, critical to the function of lymphoid organs. Recent studies have demonstrated important roles for CD11c+ dendritic cells in the induction, as well as the maintenance, of vascular addressin expression and, therefore, the function of HEVs. Tertiary lymphoid organs (TLOs) are HEV containing LN-like structures that develop inside organized tissues undergoing chronic immune-mediated inflammation. In autoimmune lesions, the development of TLOs is thought to exacerbate disease. In cancerous tissues, the development of HEVs and TLOs is associated with improved patient outcomes in several cancers. Therefore, it is important to understand what drives the development of HEVs and TLOs and how these structures contribute to pathology. In several human diseases and experimental animal models of chronic inflammation, there are some similarities between the development and function of HEVs within LN and TLOs. This review will summarize current knowledge of how hemopoietic cells with lymphoid tissue-inducing, HEV-inducing, and HEV-maintaining properties are recruited from the bloodstream to induce the development and

  18. Engineering Cell Shape and Function

    Science.gov (United States)

    Singhvi, Rahul; Kumar, Amit; Lopez, Gabriel P.; Stephanopoulos, Gregory N.; Wang, Daniel I. C.; Whitesides, George M.; Ingber, Donald E.

    1994-04-01

    An elastomeric stamp, containing defined features on the micrometer scale, was used to imprint gold surfaces with specific patterns of self-assembled monolayers of alkanethiols and, thereby, to create islands of defined shape and size that support extracellular matrix protein adsorption and cell attachment. Through this technique, it was possible to place cells in predetermined locations and arrays, separated by defined distances, and to dictate their shape. Limiting the degree of cell extension provided control over cell growth and protein secretion. This method is experimentally simple and highly adaptable. It should be useful for applications in biotechnology that require analysis of individual cells cultured at high density or repeated access to cells placed in specified locations.

  19. Analysis of Glial Cell Development and Function in Drosophila

    Science.gov (United States)

    Stork, Tobias; Bernardos, Rebecca; Freeman, Marc R.

    2016-01-01

    Glial cells are the most abundant cell type in our brains, yet we understand very little about their development and function. An accumulating body of work over the last decade has revealed that glia are critical regulators of nervous system development, function, and health. Based on morphological and molecular criteria, glia in Drosophila melanogaster are very similar to their mammalian counterparts, suggesting that a detailed investigation of fly glia has the potential to add greatly to our understanding of fundamental aspects of glial cell biology. In this article, we provide an overview of the subtypes of glial cells found in Drosophila and discuss our current understanding of their functions, the development of a subset of well-defined glial lineages, and the molecular-genetic tools available for manipulating glial subtypes in vivo. PMID:22194269

  20. Gallium arsenide exposure impairs splenic B cell accessory function.

    Science.gov (United States)

    Gondre-Lewis, Timothy A; Hartmann, Constance B; Caffrey, Rebecca E; McCoy, Kathleen L

    2003-03-01

    Gallium arsenide (GaAs) is utilized in industries for its semiconductor and optical properties. Chemical exposure of animals systemically suppresses several immune functions. The ability of splenic B cells to activate antigen-specific helper CD4(+) T cell hybridomas was assessed, and various aspects of antigen-presenting cell function were examined. GaAs-exposed murine B cells were impaired in processing intact soluble protein antigens, and the defect was antigen dependent. In contrast, B cells after exposure competently presented peptides to the T cells, which do not require processing. Cell surface expression of major histocompatibility complex (MHC) class II molecules and several costimulatory molecules on splenic B cells, which are critical for helper T cell activation, was not affected by chemical exposure. GaAs exposure also did not influence the stability of MHC class II heterodimers, suggesting that the defect may precede peptide exchange. GaAs-exposed B cells contained a normal level of aspartyl cathepsin activity; however, proteolytic activities of thiol cathepsins B and L were approximately half the control levels. Furthermore, two cleavage fragments of invariant chain, a molecular chaperone of MHC class II molecules, were increased in GaAs-exposed B cells, indicative of defective degradation. Thus, diminished thiol proteolytic activity in B cells may be responsible for their impaired antigen processing and invariant chain degradation, which may contribute to systemic immunosuppression caused by GaAs exposure.

  1. NF-κB Essential Modulator (NEMO) Is Critical for Thyroid Function*

    Science.gov (United States)

    Reale, Carla; Iervolino, Anna; Scudiero, Ivan; Ferravante, Angela; D'Andrea, Luca Egildo; Mazzone, Pellegrino; Zotti, Tiziana; Leonardi, Antonio; Roberto, Luca; Zannini, Mariastella; de Cristofaro, Tiziana; Shanmugakonar, Muralitharan; Capasso, Giovambattista; Pasparakis, Manolis; Vito, Pasquale; Stilo, Romania

    2016-01-01

    The I-κB kinase (IKK) subunit NEMO/IKKγ (NEMO) is an adapter molecule that is critical for canonical activation of NF-κB, a pleiotropic transcription factor controlling immunity, differentiation, cell growth, tumorigenesis, and apoptosis. To explore the functional role of canonical NF-κB signaling in thyroid gland differentiation and function, we have generated a murine strain bearing a genetic deletion of the NEMO locus in thyroid. Here we show that thyrocyte-specific NEMO knock-out mice gradually develop hypothyroidism after birth, which leads to reduced body weight and shortened life span. Histological and molecular analysis indicate that absence of NEMO in thyrocytes results in a dramatic loss of the thyroid gland cellularity, associated with down-regulation of thyroid differentiation markers and ongoing apoptosis. Thus, NEMO-dependent signaling is essential for normal thyroid physiology. PMID:26786105

  2. Perovskite solar cells - An overview of critical issues

    Science.gov (United States)

    Djurišić, A. B.; Liu, F. Z.; Tam, H. W.; Wong, M. K.; Ng, A.; Surya, C.; Chen, W.; He, Z. B.

    2017-05-01

    Perovskite solar cell research has been attracting increasing attention in recent years. In this review paper, we will provide an overview of the recent developments in terms of material composition, deposition techniques, and the device architecture (the choice of charge transport layers and electrodes). Then, we will critically discuss some of the major problems, namely device stability, hysteresis, environmental implications due to the presence of a toxic metal (lead), and difficulties in fabrication of large area and/or flexible devices. In addition, we will also discuss tandem cells and modules, as well as the application of perovskites in other devices and the integration of perovskite solar cells with other devices. Finally, we discuss future outlook and important issues which need to be addressed for the wide scale applications of these devices. Lifetime and stability are identified as the key issue to be addressed for wide scale applications, and the majority of environmental impact is due to the use of organic solvents or other components in the device, not the lead-containing perovskite absorber. The standardisation of the testing conditions and more studies involving outdoor testing are needed for convincing demonstrations of good stability as opposed to dark storage testing. Another key issue is upscaling and reproducibility of the film preparation, which can be problematic due to high sensitivity of the perovskite film to the processing conditions. To overcome these obstacles multilaboratory collaborative efforts would be highly desirable.

  3. Regulation of satellite cell function in sarcopenia

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    Stephen E Alway

    2014-09-01

    Full Text Available The mechanisms contributing to sarcopenia include reduced satellite cell (myogenic stem cell function that is impacted by the environment (niche of these cells. Satellite cell function is affected by oxidative stress, which is elevated in aged muscles, and this along with changes in largely unknown systemic factors, likely contribute to the manner in which satellite cells respond to stressors such as exercise, disuse or rehabilitation in sarcopenic muscles. Nutritional intervention provides one therapeutic strategy to improve the satellite cell niche and systemic factors, with the goal of improving satellite cell function in aging muscles. Although many elderly persons consume various nutraceuticals with the hope of improving health, most of these compounds have not been thoroughly tested, and the impacts that they might have on sarcopenia, and satellite cell function are not clear. This review discusses data pertaining to the satellite cell responses and function in aging skeletal muscle, and the impact that three compounds: resveratrol, green tea catechins and β-Hydroxy-β-methylbutyrate have on regulating satellite cell function and therefore contributing to reducing sarcopenia or improving muscle mass after disuse in aging. The data suggest that these nutraceutical compounds improve satellite cell function during rehabilitative loading in animal models of aging after disuse (i.e., muscle regeneration. While these compounds have not been rigorously tested in humans, the data from animal models of aging provide a strong basis for conducting additional focused work to determine if these or other nutraceuticals can offset the muscle losses, or improve regeneration in sarcopenic muscles of older humans via improving satellite cell function.

  4. Regulation of Satellite Cell Function in Sarcopenia

    Science.gov (United States)

    Alway, Stephen E.; Myers, Matthew J.; Mohamed, Junaith S.

    2014-01-01

    The mechanisms contributing to sarcopenia include reduced satellite cell (myogenic stem cell) function that is impacted by the environment (niche) of these cells. Satellite cell function is affected by oxidative stress, which is elevated in aged muscles, and this along with changes in largely unknown systemic factors, likely contribute to the manner in which satellite cells respond to stressors such as exercise, disuse, or rehabilitation in sarcopenic muscles. Nutritional intervention provides one therapeutic strategy to improve the satellite cell niche and systemic factors, with the goal of improving satellite cell function in aging muscles. Although many elderly persons consume various nutraceuticals with the hope of improving health, most of these compounds have not been thoroughly tested, and the impacts that they might have on sarcopenia and satellite cell function are not clear. This review discusses data pertaining to the satellite cell responses and function in aging skeletal muscle, and the impact that three compounds: resveratrol, green tea catechins, and β-Hydroxy-β-methylbutyrate have on regulating satellite cell function and therefore contributing to reducing sarcopenia or improving muscle mass after disuse in aging. The data suggest that these nutraceutical compounds improve satellite cell function during rehabilitative loading in animal models of aging after disuse (i.e., muscle regeneration). While these compounds have not been rigorously tested in humans, the data from animal models of aging provide a strong basis for conducting additional focused work to determine if these or other nutraceuticals can offset the muscle losses, or improve regeneration in sarcopenic muscles of older humans via improving satellite cell function. PMID:25295003

  5. A new functional site W115 in CdtA is critical for Aggregatibacter actinomycetemcomitans cytolethal distending toxin.

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    Lu Li

    Full Text Available Aggregatibacter actinomycetemcomitans, a specific pathogen of localized aggressive periodontitis, produces a cytolethal distending toxin (CDT that arrests eukaryotic cells irreversibly in G0/G1 or G2/M phase of the cell cycle. Although structural studies show that the aromatic patch region of CdtA plays an important role in its biological activity, the functional sites of CdtA have not been firmly established. In this study, site-specific mutagenesis strategy was employed for cdtA point mutations construction so as to examine the contributions of individual amino acids to receptor binding and the biological activity of holotoxin. The binding ability was reduced in CdtA(Y181ABC holotoxin and the biological function of CDT was not weaken in CdtA(Y105ABC, CdtA(Y125ABC, CdtA(F109ABC and CdtA(S106NBC holotoxin suggesting that these sites were not critical to CDT. But the binding activity and cell cycle arrest ability of holotoxin complexes were inhibited in CdtA(W115GBC. And this site did not affect the holotoxin assembly by size exclusion chromatography. Therefore, W115 might be a critical site of CdtA binding ability. These findings suggest that the functional sites of CdtA are not only in the aromatic patch region. W115, the new functional site is critical for receptor binding and cell cycle arrest, which provides potential targets for pharmacological disruption of CDT activity.

  6. Concentration-Discharge Relations in the Critical Zone: Implications for Resolving Critical Zone Structure, Function, and Evolution

    Science.gov (United States)

    Chorover, Jon; Derry, Louis A.; McDowell, William H.

    2017-11-01

    Critical zone science seeks to develop mechanistic theories that describe critical zone structure, function, and long-term evolution. One postulate is that hydrogeochemical controls on critical zone evolution can be inferred from solute discharges measured down-gradient of reactive flow paths. These flow paths have variable lengths, interfacial compositions, and residence times, and their mixing is reflected in concentration-discharge (C-Q) relations. Motivation for this special section originates from a U.S. Critical Zone Observatories workshop that was held at the University of New Hampshire, 20-22 July 2015. The workshop focused on resolving mechanistic CZ controls over surface water chemical dynamics across the full range of lithogenic (e.g., nonhydrolyzing and hydrolyzing cations and oxyanions) and bioactive solutes (e.g., organic and inorganic forms of C, N, P, and S), including dissolved and colloidal species that may cooccur for a given element. Papers submitted to this special section on "concentration-discharge relations in the critical zone" include those from authors who attended the workshop, as well as others who responded to the open solicitation. Submissions were invited that utilized information pertaining to internal, integrated catchment function (relations between hydrology, biogeochemistry, and landscape structure) to help illuminate controls on observed C-Q relations.

  7. Critical roles of p53 in epithelial-mesenchymal transition and metastasis of hepatocellular carcinoma cells.

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    Zheng Wang

    Full Text Available Hepatocellular carcinoma (HCC is one of the most malignant tumors and the biggest obstacle in curing HCC is its high metastasis potential. Alteration of p53 is the most frequent genetic change found in HCC. Although the biological function of p53 in tumor initiation and progression has been well characterized, whether or not p53 is implicated in metastasis of HCC is largely unknown. In this study, we analyzed the potential functions of p53 in epithelial-mesenchymal transition (EMT and metastasis of HCC cells. Both insulin- and TGF-β1-induced changes of critical EMT markers were greatly enhanced by p53 knockdown in HCC cells. The insulin- and TGF-β1-stimulated migration of HCC cells were enhanced by p53 knockdown. Furthermore, in vivo metastasis of HCC cells using different mouse models was robustly enhanced by p53 knockdown. In addition, we found that p53 regulation on EMT and metastasis involves β-catenin signaling. The nuclear accumulation and transcriptional activity of β-catenin was modulated by p53. The enhanced EMT phenotype, cell migration and tumor metastasis of HCC cells by p53 knockdown were abrogated by inhibiting β-catenin signal pathway. In conclusion, this study reveals that p53 plays a pivotal role in EMT and metastasis of HCC cells via its regulation on β-catenin signaling.

  8. Generation of functional eyes from pluripotent cells.

    Directory of Open Access Journals (Sweden)

    Andrea S Viczian

    2009-08-01

    Full Text Available Pluripotent cells such as embryonic stem (ES and induced pluripotent stem (iPS cells are the starting point from which to generate organ specific cell types. For example, converting pluripotent cells to retinal cells could provide an opportunity to treat retinal injuries and degenerations. In this study, we used an in vivo strategy to determine if functional retinas could be generated from a defined population of pluripotent Xenopus laevis cells. Animal pole cells isolated from blastula stage embryos are pluripotent. Untreated, these cells formed only epidermis, when transplanted to either the flank or eye field. In contrast, misexpression of seven transcription factors induced the formation of retinal cell types. Induced retinal cells were committed to a retinal lineage as they formed eyes when transplanted to the flanks of developing embryos. When the endogenous eye field was replaced with induced retinal cells, they formed eyes that were molecularly, anatomically, and electrophysiologically similar to normal eyes. Importantly, induced eyes could guide a vision-based behavior. These results suggest the fate of pluripotent cells may be purposely altered to generate multipotent retinal progenitor cells, which differentiate into functional retinal cell classes and form a neural circuitry sufficient for vision.

  9. Thermal partition function of non-critical bosonic strings

    International Nuclear Information System (INIS)

    Suzuki, Hiroshi.

    1989-06-01

    The thermal free energy of free non-critical bosonic strings in a D-dimensional space-time is examined. By integrating (or summing) over the Weyl freedom, the free energy and the one-loop vacuum amplitude are modular invariant for any D < 26. Thus the (background) Weyl invariance is realized. In the case of L → ∞, where L is the compactification radius of the Weyl mode, the physical spectrum circulating in the loop becomes continuous. A connection between this continuous spectrum and the unitarity of string perturbation theory is briefly mentioned. (author)

  10. REGULATORY T–CELLS: ORIGIN AND FUNCTION

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    I. S. Freidlin

    2005-01-01

    Full Text Available Abstract. Over the past decade a population of so–called “regulatory T cells” (Treg cells has been linked to the prevention of autoimmunity. In this review we discuss the molecular mechanisms of Treg cells development and function including the identification of the unique molecular marker of Treg cells – the transcription factor Foxp3. We discuss also the mechanisms of suppression, which include the direct cell contact through binding of cell surface molecules CTLA–4 on Treg cells to CD80/CD86 molecules of effector T cells and the local secretion of cytokines (IL–10, TGFβ. Deficiency in or dysfunction of these cells can be a cause of autoimmune disease. These cells are a good target for designing ways to induce or abrogate immunological tolerance to self and non–self antigens. (Med. Immunol., 2005, vol.7, № 4, pp. 347–354

  11. Mast-Cell-Derived TNF Amplifies CD8+ Dendritic Cell Functionality and CD8+ T Cell Priming

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    Jan Dudeck

    2015-10-01

    Full Text Available Mast cells are critical promoters of adaptive immunity in the contact hypersensitivity model, but the mechanism of allergen sensitization is poorly understood. Using Mcpt5-CreTNFFL/FL mice, we show here that the absence of TNF exclusively in mast cells impaired the expansion of CD8+ T cells upon sensitization and the T-cell-driven adaptive immune response to elicitation. T cells primed in the absence of mast cell TNF exhibited a diminished efficiency to transfer sensitization to naive recipients. Specifically, mast cell TNF promotes CD8+ dendritic cell (DC maturation and migration to draining lymph nodes. The peripherally released mast cell TNF further critically boosts the CD8+ T-cell-priming efficiency of CD8+ DCs, thereby linking mast cell effects on T cells to DC modulation. Collectively, our findings identify the distinct potential of mast cell TNF to amplify CD8+ DC functionality and CD8+ T-cell-dominated adaptive immunity, which may be of great importance for immunotherapy and vaccination approaches.

  12. The Green's function method for critical heterogeneous slabs

    International Nuclear Information System (INIS)

    Kornreich, D.E.

    1996-01-01

    Recently, the Green's Function Method (GFM) has been employed to obtain benchmark-quality results for nuclear engineering and radiative transfer calculations. This was possible because of fast and accurate calculations of the Green's function and the associated Fourier and Laplace transform inversions. Calculations have been provided in one-dimensional slab geometries for both homogeneous and heterogeneous media. A heterogeneous medium is analyzed as a series of homogeneous slabs, and Placzek's lemma is used to extend each slab to infinity. This allows use of the infinite medium Green's function (the anisotropic plane source in an infinite homogeneous medium) in the solution. To this point, a drawback of the GFM has been the limitation to media with c 1; however, mathematical solutions exist which result in oscillating Green's functions. Such calculations are briefly discussing. The limitation to media with c < 1 has been relaxed so that the Green's function may also be calculated for media with c ≥ 1. Thus, materials that contain fissionable isotopes may be modeled

  13. Dynamics of certain class of critically bounded entire transcendental functions

    Science.gov (United States)

    Guru Prem Prasad, M.; Nayak, Tarakanta

    2007-05-01

    Let E denote the class of all transcendental entire functions for and an[greater-or-equal, slanted]0 for all n[greater-or-equal, slanted]0 such that f(x)>0 for x0. It is also shown that the Fatou set of f[lambda] is connected whenever it is an attracting basin and the immediate basin contains all the finite singular values of f[lambda]. Finally, a number of interesting examples of entire transcendental functions from the class E are discussed.

  14. Role of Polyamines in Immune Cell Functions

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    Rebecca S. Hesterberg

    2018-03-01

    Full Text Available The immune system is remarkably responsive to a myriad of invading microorganisms and provides continuous surveillance against tissue damage and developing tumor cells. To achieve these diverse functions, multiple soluble and cellular components must react in an orchestrated cascade of events to control the specificity, magnitude and persistence of the immune response. Numerous catabolic and anabolic processes are involved in this process, and prominent roles for l-arginine and l-glutamine catabolism have been described, as these amino acids serve as precursors of nitric oxide, creatine, agmatine, tricarboxylic acid cycle intermediates, nucleotides and other amino acids, as well as for ornithine, which is used to synthesize putrescine and the polyamines spermidine and spermine. Polyamines have several purported roles and high levels of polyamines are manifest in tumor cells as well in autoreactive B- and T-cells in autoimmune diseases. In the tumor microenvironment, l-arginine catabolism by both tumor cells and suppressive myeloid cells is known to dampen cytotoxic T-cell functions suggesting there might be links between polyamines and T-cell suppression. Here, we review studies suggesting roles of polyamines in normal immune cell function and highlight their connections to autoimmunity and anti-tumor immune cell function.

  15. Immune Monitoring in Cancer Vaccine Clinical Trials: Critical Issues of Functional Flow Cytometry-Based Assays

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    Iole Macchia

    2013-01-01

    Full Text Available The development of immune monitoring assays is essential to determine the immune responses against tumor-specific antigens (TSAs and tumor-associated antigens (TAAs and their possible correlation with clinical outcome in cancer patients receiving immunotherapies. Despite the wide range of techniques used, to date these assays have not shown consistent results among clinical trials and failed to define surrogate markers of clinical efficacy to antitumor vaccines. Multiparameter flow cytometry- (FCM- based assays combining different phenotypic and functional markers have been developed in the past decade for informative and longitudinal analysis of polyfunctional T-cells. These technologies were designed to address the complexity and functional heterogeneity of cancer biology and cellular immunity and to define biomarkers predicting clinical response to anticancer treatment. So far, there is still a lack of standardization of some of these immunological tests. The aim of this review is to overview the latest technologies for immune monitoring and to highlight critical steps involved in some of the FCM-based cellular immune assays. In particular, our laboratory is focused on melanoma vaccine research and thus our main goal was the validation of a functional multiparameter test (FMT combining different functional and lineage markers to be applied in clinical trials involving patients with melanoma.

  16. Mitochondria, endothelial cell function, and vascular diseases.

    Science.gov (United States)

    Tang, Xiaoqiang; Luo, Yu-Xuan; Chen, Hou-Zao; Liu, De-Pei

    2014-01-01

    Mitochondria are perhaps the most sophisticated and dynamic responsive sensing systems in eukaryotic cells. The role of mitochondria goes beyond their capacity to create molecular fuel and includes the generation of reactive oxygen species, the regulation of calcium, and the activation of cell death. In endothelial cells, mitochondria have a profound impact on cellular function under both healthy and diseased conditions. In this review, we summarize the basic functions of mitochondria in endothelial cells and discuss the roles of mitochondria in endothelial dysfunction and vascular diseases, including atherosclerosis, diabetic vascular dysfunction, pulmonary artery hypertension, and hypertension. Finally, the potential therapeutic strategies to improve mitochondrial function in endothelial cells and vascular diseases are also discussed, with a focus on mitochondrial-targeted antioxidants and calorie restriction.

  17. Mitochondria, Endothelial Cell Function and Vascular Diseases

    Directory of Open Access Journals (Sweden)

    Xiaoqiang eTang

    2014-05-01

    Full Text Available Mitochondria are perhaps the most sophisticated and dynamic responsive sensing systems in eukaryotic cells. The role of mitochondria goes beyond their capacity to create molecular fuel and includes the generation of reactive oxygen species, the regulation of calcium, and the activation of cell death. In endothelial cells, mitochondria have a profound impact on cellular function under both healthy and diseased conditions. In this review, we summarize the basic functions of mitochondria in endothelial cells and discuss the roles of mitochondria in endothelial dysfunction and vascular diseases, including atherosclerosis, diabetic vascular dysfunction, pulmonary artery hypertension and hypertension. Finally, the potential therapeutic strategies to improve mitochondrial function in endothelial cells and vascular diseases are also discussed, with a focus on mitochondrial-targeted antioxidants and calorie restriction.

  18. Slp-76 is a critical determinant of NK cell-mediated recognition of missing-self targets

    Science.gov (United States)

    Lampe, Kristin; Endale, Mehari; Cashman, Siobhan; Fang, Hao; Mattner, Jochen; Hildeman, David; Hoebe, Kasper

    2015-01-01

    Absence of MHC class I expression is an important mechanism by which NK cells recognize a variety of target cells, yet the pathways underlying “missing-self” recognition, including the involvement of activating receptors, remain poorly understood. Using ENU mutagenesis in mice, we identified a germline mutant, designated Ace, with a marked defect in NK cell-mediated recognition and elimination of “missing-self” targets. The causative mutation was linked to chromosome 11 and identified as a missense mutation [Thr428Ile] in the SH2 domain of Slp-76—a critical adapter molecule downstream of ITAM-containing surface receptors. The Slp-76 Ace mutation behaved as a hypomorphic allele—while no major defects were observed in conventional T cell development/function, a marked defect in NK cell-mediated elimination of β2-Microglobulin (β2M)-deficient target cells was observed. Further studies revealed Slp-76 to control NK cell receptor expression and maturation, however, activation of Slp-76ace/ace NK cells through ITAM-containing NK cell receptors or allogeneic/tumor target cells appeared largely unaffected. Imagestream analysis of the NK-β2M−/− target cell synapse, revealed a specific defect in actin recruitment to the conjugate synapse in Slp-76ace/ace NK cells. Overall these studies establish Slp-76 as a critical determinant of NK cell development and NK cell-mediated elimination of missing-self target cells. PMID:25929249

  19. Data processing and critical function status display system in the nuclear power plant monitoring systems

    International Nuclear Information System (INIS)

    Sinjeri, Lj.; Plackovic, R.

    1984-01-01

    The Critical Function Monitoring System is a data acquisition and display system designed for effective presentation of essential nuclear plant operational data enabling supervision of the safety status of the nuclear plant by the operational staff. In this article the system functional requirements have been analysed and in accordance with the results of this analysis approach to defininf the design basis for realisation of the Critical Function Monitoring System by 'RK' equipment has been briefly described. (author)

  20. Human Pluripotent Stem Cell Differentiation into Functional Epicardial Progenitor Cells

    Directory of Open Access Journals (Sweden)

    Juan Antonio Guadix

    2017-12-01

    Full Text Available Summary: Human pluripotent stem cells (hPSCs are widely used to study cardiovascular cell differentiation and function. Here, we induced differentiation of hPSCs (both embryonic and induced to proepicardial/epicardial progenitor cells that cover the heart during development. Addition of retinoic acid (RA and bone morphogenetic protein 4 (BMP4 promoted expression of the mesodermal marker PDGFRα, upregulated characteristic (proepicardial progenitor cell genes, and downregulated transcription of myocardial genes. We confirmed the (proepicardial-like properties of these cells using in vitro co-culture assays and in ovo grafting of hPSC-epicardial cells into chick embryos. Our data show that RA + BMP4-treated hPSCs differentiate into (proepicardial-like cells displaying functional properties (adhesion and spreading over the myocardium of their in vivo counterpart. The results extend evidence that hPSCs are an excellent model to study (proepicardial differentiation into cardiovascular cells in human development and evaluate their potential for cardiac regeneration. : The authors have shown that hPSCs can be instructed in vitro to differentiate into a specific cardiac embryonic progenitor cell population called the proepicardium. Proepicardial cells are required for normal formation of the heart during development and might contribute to the development of cell-based therapies for heart repair. Keywords: human pluripotent stem cells, proepicardium, progenitor cells, cardiovascular, differentiation

  1. Critical tumor suppressor function mediated by epithelial Mig-6 in endometrial cancer

    Science.gov (United States)

    Kim, Tae Hoon; Lee, Dong-Kee; Cho, Sung-Nam; Orvis, Grant D.; Behringer, Richard R.; Lydon, John P.; Ku, Bon Jeong; McCampbell, Adrienne S.; Broaddus, Russell R.; Jeong, Jae-Wook

    2013-01-01

    Endometrial cancer is preceded by endometrial hyperplasia, unopposed estrogen exposure and genetic alterations, but the precise causes of endometrial cancer remain uncertain. Mig-6, mainly known as a negative regulator of the EGF receptor, is an important mediator of progesterone signaling in the uterus, where it mediates tumor suppression by modulating endometrial stromal-epithelial communications. In this study, we investigated the function of Mig-6 in the uterine epithelium using a tissue-specific gene knockout strategy, in which floxed Mig-6 (Mig-6f/f) mice were crossed to Wnt7a-Cre mice (Wnt7acre+ Mig-6f/f). Wnt7acre+ Mig-6f/f mice developed endometrial hyperplasia and estrogen-dependent endometrial cancer, exhibiting increased proliferation in epithelial cells as well as apoptosis in sub-epithelial stromal cells. We documented increased expression of NOTCH1 and BIRC3 in epithelial cells of Wnt7acre+ Mig-6f/f mice and decreased expression of the progesterone receptor (PR) in stromal cells. Progesterone therapy controls endometrial growth and prevents endometrial cancer, but the effectiveness of progesterone as a treatment for women with endometrial cancer is less clear. We noted that the hyperplasic phenotype of Wnt7acre+ Mig-6f/f mice was prevented by progesterone treatment, whereas this treatment had no effect in PRcre/+ Mig-6f/f mice where Mig-6 was deleted in both the epithelial and stromal compartments of the uterus. In contrast, activation of progesterone signaling in the stroma regulated proliferation and apoptosis in the epithelium via suppression of ERα signaling there. In summary, our results establish that epithelial Mig-6 functions as a critical tumor suppressor that mediates the ability of progesterone to prevent the development of endometrial cancer. PMID:23811943

  2. Characterization of tetratricopeptide repeat-containing proteins critical for cilia formation and function.

    Directory of Open Access Journals (Sweden)

    Yanan Xu

    Full Text Available Cilia formation and function require a special set of trafficking machinery termed intraflagellar transport (IFT, consisting mainly of protein complexes IFT-A, IFT-B, BBSome, and microtubule-dependent molecular motors. Tetratricopeptide repeat-containing (TTC proteins are widely involved in protein complex formation. Nine of them are known to serve as components of the IFT or BBSome complexes. How many TTC proteins are cilia-related and how they function, however, remain unclear. Here we show that twenty TTC genes were upregulated by at least 2-fold during the differentiation of cultured mouse tracheal epithelial cells (MTECs into multiciliated cells. Our systematic screen in zebrafish identified four novel TTC genes, ttc4, -9c, -36, and -39c, that are critical for cilia formation and motility. Accordingly, their zebrafish morphants displayed typical ciliopathy-related phenotypes, including curved body, abnormal otolith, hydrocephalus, and defective left-right patterning. The morphants of ttc4 and ttc25, a known cilia-related gene, additionally showed pronephric cyst formation. Immunoprecipitation indicated associations of TTC4, -9c, -25, -36, and -39c with components or entire complexes of IFT-A, IFT-B, or BBSome, implying their participations in IFT or IFT-related activities. Our results provide a global view for the relationship between TTC proteins and cilia.

  3. Interleukin-2 and STAT5 in regulatory T cell development and function

    OpenAIRE

    Mahmud, Shawn A.; Manlove, Luke S.; Farrar, Michael A.

    2013-01-01

    Interleukin-2 and its downstream target STAT5 have effects on many aspects of immune function. This has been perhaps best documented in regulatory T cells. In this review we summarize the initial findings supporting a role for IL2 and STAT5 in regulatory T cell development and outline more recent studies describing how this critical signaling pathway entrains regulatory T cell differentiation and affects regulatory T cell function.

  4. Induction of Functional Hair-Cell-Like Cells from Mouse Cochlear Multipotent Cells

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    Quanwen Liu

    2016-01-01

    Full Text Available In this paper, we developed a two-step-induction method of generating functional hair cells from inner ear multipotent cells. Multipotent cells from the inner ear were established and induced initially into progenitor cells committed to the inner ear cell lineage on the poly-L-lysine substratum. Subsequently, the committed progenitor cells were cultured on the mitotically inactivated chicken utricle stromal cells and induced into hair-cell-like cells containing characteristic stereocilia bundles. The hair-cell-like cells exhibited rapid permeation of FM1-43FX. The whole-cell patch-clamp technique was used to measure the membrane currents of cells differentiated for 7 days on chicken utricle stromal cells and analyze the biophysical properties of the hair-cell-like cells by recording membrane properties of cells. The results suggested that the hair-cell-like cells derived from inner ear multipotent cells were functional following differentiation in an enabling environment.

  5. Functional Outcomes and Physical Impairments in Pediatric Critical Care Survivors: A Scoping Review.

    Science.gov (United States)

    Ong, Chengsi; Lee, Jan Hau; Leow, Melvin K S; Puthucheary, Zudin A

    2016-05-01

    Although more children are surviving critical illness, little is known about long-term physical impairment. This scoping review aims to critically appraise existing literature on functional outcome measurement tools, prevalence, and risk factors for physical impairments in pediatric critical care survivors. PubMed, Embase, and Cumulative Index to Nursing and Allied Health Literature, using a combination of MeSH terms and keywords (critical illness, intensive care, and functional outcomes/status). All human studies reporting functional outcomes in children 0-18 years old admitted to the PICU. Non-English language, adult and preterm infant studies were excluded. Three global assessment tools and eight multidimensional measures were used to measure functional outcome in pediatric survivors of critical illness. Rates of acquired functional impairment in a general pediatric intensive care cohort ranged from 10% to 36% at discharge and 10% to 13% after more than 2 years. Risk factors for acquired functional impairment include illness severity, the presence of organ dysfunction, length of ICU stay, and younger age. There is some evidence that physical impairment may be more severe and persistent than psychosocial components. Functional impairment may be persistent in pediatric survivors of critical care. Unfortunately, studies varied largely in measurement timing and tools used. The lack of differentiation between impairment in different functional domains limited the generalizability of data. Further studies using a combination of standardized measures at various time points of the disease process can help establish more comprehensive rates of physical impairment.

  6. Functions of Prdm16 in thermogenic fat cells.

    Science.gov (United States)

    Ishibashi, Jeff; Seale, Patrick

    2015-01-01

    The PR-domain containing 16 (Prdm16) protein is a powerful inducer of the thermogenic phenotype in fat cells. In both developmental (brown) and induced (beige) thermogenic adipose tissue, Prdm16 has a critical role in maintaining proper tissue structure and function. It has roles throughout the course of differentiation, beginning with lineage determination activity in precursor cells, and continuing with coactivator functions that enable and maintain thermogenic gene expression. These abilities are primarily mediated by interactions with other adipogenic factors, suggesting that Prdm16 acts to coordinate the overall brown adipose phenotype. Mouse models have confirmed that thermogenic adipose depends upon Prdm16, and that this type of fat tissue provides substantial metabolic protection against the harmful effects of a high fat/high energy diet. Activation of Prdm16, therefore, holds promise for stimulating thermogenesis in fat cells to reduce human obesity and its complications.

  7. Functions of proteoglycans at the cell surface

    DEFF Research Database (Denmark)

    Höök, M; Woods, A; Johansson, S

    1986-01-01

    Proteoglycans (primarily heparan sulphate proteoglycans) are found at the surface of most adherent eukaryotic cells. Earlier studies suggest that these molecules can be associated with the cell surface principally by two different mechanisms. Proteoglycans may occur as membrane......-intercalated glycoproteins, where the core protein of the proteoglycan is anchored in the lipid interior of the plasma membrane, or they may be bound via the polysaccharide components of the molecule to specific anchoring proteins present at the cell surface. A number of functions have been proposed for cell surface......-associated proteoglycans, including: regulation of cell-substrate adhesion; regulation of cell proliferation; participation in the binding and uptake of extracellular components; and participation in the regulation of extracellular matrix formation. Evidence is discussed suggesting that the cell-associated heparan...

  8. Critical adsorption profiles around a sphere and a cylinder in a fluid at criticality: Local functional theory

    Science.gov (United States)

    Yabunaka, Shunsuke; Onuki, Akira

    2017-09-01

    We study universal critical adsorption on a solid sphere and a solid cylinder in a fluid at bulk criticality, where preferential adsorption occurs. We use a local functional theory proposed by Fisher et al. [M. E. Fisher and P. G. de Gennes, C. R. Acad. Sci. Paris Ser. B 287, 207 (1978); M. E. Fisher and H. Au-Yang, Physica A 101, 255 (1980), 10.1016/0378-4371(80)90112-0]. We calculate the mean order parameter profile ψ (r ) , where r is the distance from the sphere center and the cylinder axis, respectively. The resultant differential equation for ψ (r ) is solved exactly around a sphere and numerically around a cylinder. A strong adsorption regime is realized except for very small surface field h1, where the surface order parameter ψ (a ) is determined by h1 and is independent of the radius a . If r considerably exceeds a , ψ (r ) decays as r-(1 +η ) for a sphere and r-(1 +η )/2 for a cylinder in three dimensions, where η is the critical exponent in the order parameter correlation at bulk criticality.

  9. Hydrologic Synthesis Across the Critical Zone Observatory Network: A Step Towards Understanding the Coevolution of Critical Zone Function and Structure

    Science.gov (United States)

    Wlostowski, A. N.; Harman, C. J.; Molotch, N. P.

    2017-12-01

    The physical and biological architecture of the Earth's Critical Zone controls hydrologic partitioning, storage, and chemical evolution of precipitated water. The Critical Zone Observatory (CZO) Network provides an ideal platform to explore linkages between catchment structure and hydrologic function across a gradient of geologic and climatic settings. A legacy of hypothesis-motivated research at each site has generated a wealth of data characterizing the architecture and hydrologic function of the critical zone. We will present a synthesis of this data that aims to elucidate and explain (in the sense of making mutually intelligible) variations in hydrologic function across the CZO network. Top-down quantitative signatures of the storage and partitioning of water at catchment scales extracted from precipitation, streamflow, and meteorological data will be compared with each other, and provide quantitative benchmarks to assess differences in perceptual models of hydrologic function at each CZO site. Annual water balance analyses show that CZO sites span a wide gradient of aridity and evaporative partitioning. The aridity index (PET/P) ranges from 0.3 at Luquillo to 4.3 at Reynolds Creek, while the evaporative index (E/P) ranges from 0.3 at Luquillo (Rio Mamayes) to 0.9 at Reynolds Creek (Reynolds Creek Outlet). Snow depth and SWE observations reveal that snowpack is an important seasonal storage reservoir at three sites: Boulder, Jemez, Reynolds Creek and Southern Sierra. Simple dynamical models are also used to infer seasonal patterns of subsurface catchment storage. A root-zone water balance model reveals unique seasonal variations in plant-available water storage. Seasonal patterns of plant-available storage are driven by the asynchronicity of seasonal precipitation and evaporation cycles. Catchment sensitivity functions are derived at each site to infer relative changes in hydraulic storage (the apparent storage reservoir responsible for modulating streamflow

  10. Selectionist and evolutionary approaches to brain function: a critical appraisal

    Directory of Open Access Journals (Sweden)

    Chrisantha Thomas Fernando

    2012-04-01

    Full Text Available We consider approaches to brain dynamics and function that have been claimed to be Darwinian. These include Edelman’s theory of neuronal group selection, Changeux’s theory of synaptic selection and selective stabilization of pre-representations, Seung’s Darwinian synapse, Loewenstein’s synaptic melioration, Adam’s selfish synapse and Calvin’s replicating activity patterns. Except for the last two, the proposed mechanisms are selectionist but not truly Darwinian, because no replicators with information transfer to copies and hereditary variation can be identified in them. All of them fit, however, a generalized selectionist framework conforming to the picture of Price’s covariance formulation, which deliberately was not specific even to selection in biology, and therefore does not imply an algorithmic picture of biological evolution. Bayesian models and reinforcement learning are formally in agreement with selection dynamics. A classification of search algorithms is shown to include Darwinian replicators (evolutionary units with multiplication, heredity and variability as the most powerful mechanism in a sparsely occupied search space. Examples of why parallel competitive search with information transfer among the units is efficient are given. Finally, we review our recent attempts to construct and analyze simple models of true Darwinian evolutionary units in the brain in terms of connectivity and activity copying of neuronal groups. Although none of the proposed neuronal replicators include miraculous mechanisms, their identification remains a challenge but also a great promise.

  11. Critical role of dendritic cells in T cell retention in the interfollicular region of Peyer's patches.

    Science.gov (United States)

    Obata, Takashi; Shibata, Naoko; Goto, Yoshiyuki; Ishikawa, Izumi; Sato, Shintaro; Kunisawa, Jun; Kiyono, Hiroshi

    2013-07-15

    Peyer's patches (PPs) simultaneously initiate active and quiescent immune responses in the gut. The immunological function is achieved by the rigid regulation of cell distribution and trafficking, but how the cell distribution is maintained remains to be elucidated. In this study, we show that binding of stromal cell-derived lymphoid chemokines to conventional dendritic cells (cDCs) is essential for the retention of naive CD4(+) T cells in the interfollicular region (IFR) of PPs. Transitory depletion of CD11c(high) cDCs in mice rapidly impaired the IFR structure in the PPs without affecting B cell follicles or germinal centers, lymphoid chemokine production from stromal cells, or the immigration of naive T cells into the IFRs of PPs. The cDC-orchestrated retention of naive T cells was mediated by heparinase-sensitive molecules that were expressed on cDCs and bound the lymphoid chemokine CCL21 produced from stromal cells. These data collectively reveal that interactions among cDCs, stromal cells, and naive T cells are necessary for the formation of IFRs in the PPs.

  12. Antigen Availability Shapes T Cell Differentiation and Function during Tuberculosis.

    Science.gov (United States)

    Moguche, Albanus O; Musvosvi, Munyaradzi; Penn-Nicholson, Adam; Plumlee, Courtney R; Mearns, Helen; Geldenhuys, Hennie; Smit, Erica; Abrahams, Deborah; Rozot, Virginie; Dintwe, One; Hoff, Søren T; Kromann, Ingrid; Ruhwald, Morten; Bang, Peter; Larson, Ryan P; Shafiani, Shahin; Ma, Shuyi; Sherman, David R; Sette, Alessandro; Lindestam Arlehamn, Cecilia S; McKinney, Denise M; Maecker, Holden; Hanekom, Willem A; Hatherill, Mark; Andersen, Peter; Scriba, Thomas J; Urdahl, Kevin B

    2017-06-14

    CD4 T cells are critical for protective immunity against Mycobacterium tuberculosis (Mtb), the cause of tuberculosis (TB). Yet to date, TB vaccine candidates that boost antigen-specific CD4 T cells have conferred little or no protection. Here we examined CD4 T cell responses to two leading TB vaccine antigens, ESAT-6 and Ag85B, in Mtb-infected mice and in vaccinated humans with and without underlying Mtb infection. In both species, Mtb infection drove ESAT-6-specific T cells to be more differentiated than Ag85B-specific T cells. The ability of each T cell population to control Mtb in the lungs of mice was restricted for opposite reasons: Ag85B-specific T cells were limited by reduced antigen expression during persistent infection, whereas ESAT-6-specific T cells became functionally exhausted due to chronic antigenic stimulation. Our findings suggest that different vaccination strategies will be required to optimize protection mediated by T cells recognizing antigens expressed at distinct stages of Mtb infection. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. The effect of criticism on functional brain connectivity and associations with neuroticism.

    Directory of Open Access Journals (Sweden)

    Michelle Nadine Servaas

    Full Text Available Neuroticism is a robust personality trait that constitutes a risk factor for psychopathology, especially anxiety disorders and depression. High neurotic individuals tend to be more self-critical and are overly sensitive to criticism by others. Hence, we used a novel resting-state paradigm to investigate the effect of criticism on functional brain connectivity and associations with neuroticism. Forty-eight participants completed the NEO Personality Inventory Revised (NEO-PI-R to assess neuroticism. Next, we recorded resting state functional magnetic resonance imaging (rsfMRI during two sessions. We manipulated the second session before scanning by presenting three standardized critical remarks through headphones, in which the subject was urged to please lie still in the scanner. A seed-based functional connectivity method and subsequent clustering were used to analyse the resting state data. Based on the reviewed literature related to criticism, we selected brain regions associated with self-reflective processing and stress-regulation as regions of interest. The findings showed enhanced functional connectivity between the clustered seed regions and brain areas involved in emotion processing and social cognition during the processing of criticism. Concurrently, functional connectivity was reduced between these clusters and brain structures related to the default mode network and higher-order cognitive control. Furthermore, individuals scoring higher on neuroticism showed altered functional connectivity between the clustered seed regions and brain areas involved in the appraisal, expression and regulation of negative emotions. These results may suggest that the criticized person is attempting to understand the beliefs, perceptions and feelings of the critic in order to facilitate flexible and adaptive social behavior. Furthermore, multiple aspects of emotion processing were found to be affected in individuals scoring higher on neuroticism during

  14. Cell functional enviromics: Unravelling the function of environmental factors

    Directory of Open Access Journals (Sweden)

    Alves Paula M

    2011-06-01

    Full Text Available Abstract Background While functional genomics, focused on gene functions and gene-gene interactions, has become a very active field of research in molecular biology, equivalent methodologies embracing the environment and gene-environment interactions are relatively less developed. Understanding the function of environmental factors is, however, of paramount importance given the complex, interactive nature of environmental and genetic factors across multiple time scales. Results Here, we propose a systems biology framework, where the function of environmental factors is set at its core. We set forth a "reverse" functional analysis approach, whereby cellular functions are reconstructed from the analysis of dynamic envirome data. Our results show these data sets can be mapped to less than 20 core cellular functions in a typical mammalian cell culture, while explaining over 90% of flux data variance. A functional enviromics map can be created, which provides a template for manipulating the environmental factors to induce a desired phenotypic trait. Conclusion Our results support the feasibility of cellular function reconstruction guided by the analysis and manipulation of dynamic envirome data.

  15. Herpes simplex virus type 2 induces rapid cell death and functional impairment of murine dendritic cells in vitro

    NARCIS (Netherlands)

    Jones, CA; Fernandez, M; Herc, K; Bosnjak, L; Miranda-Saksena, M; Boadle, RA; Cunningham, A

    2003-01-01

    Dendritic cells (DC) are critical for stimulation of naive T cells. Little is known about the effect of herpes simplex virus type 2 (HSV-2) infection on DC structure or function or if the observed effects of HSV-1 on human DC are reproduced in murine DC. Here, we demonstrate that by 12 h

  16. Critical Filler Concentration in Sulfated Titania-Added Nafion™ Membranes for Fuel Cell Applications

    Directory of Open Access Journals (Sweden)

    Mirko Sgambetterra

    2016-04-01

    Full Text Available In this communication we present a detailed study of Nafion™ composite membranes containing different amounts of nanosized sulfated titania particles, synthesized through an optimized one-step synthesis procedure. Functional membrane properties, such as ionic exchange capacity and water uptake (WU ability will be described and discussed, together with thermal analysis, atomic force microscopy and Raman spectroscopy data. Also electrochemical properties such as proton conductivity and performances in hydrogen fuel cells will be presented. It has been demonstrated that a critical concentration of filler particles can boost the fuel cell performance at low humidification, exhibiting a significant improvement of the maximum power and current density delivered under 30% low-relative humidity (RH and 70 °C with respect to bare Nafion™-based systems.

  17. Invariant NKT cells: regulation and function during viral infection.

    Directory of Open Access Journals (Sweden)

    Jennifer A Juno

    Full Text Available Natural killer T cells (NKT cells represent a subset of T lymphocytes that express natural killer (NK cell surface markers. A subset of NKT cells, termed invariant NKT cells (iNKT, express a highly restricted T cell receptor (TCR and respond to CD1d-restricted lipid ligands. iNKT cells are now appreciated to play an important role in linking innate and adaptive immune responses and have been implicated in infectious disease, allergy, asthma, autoimmunity, and tumor surveillance. Advances in iNKT identification and purification have allowed for the detailed study of iNKT activity in both humans and mice during a variety of chronic and acute infections. Comparison of iNKT function between non-pathogenic simian immunodeficiency virus (SIV infection models and chronic HIV-infected patients implies a role for iNKT activity in controlling immune activation. In vitro studies of influenza infection have revealed novel effector functions of iNKT cells including IL-22 production and modulation of myeloid-derived suppressor cells, but ex vivo characterization of human iNKT cells during influenza infection are lacking. Similarly, as recent evidence suggests iNKT involvement in dengue virus pathogenesis, iNKT cells may modulate responses to a number of emerging pathogens. This Review will summarize current knowledge of iNKT involvement in responses to viral infections in both human and mouse models and will identify critical gaps in knowledge and opportunities for future study. We will also highlight recent efforts to harness iNKT ligands as vaccine adjuvants capable of improving vaccination-induced cellular immune responses.

  18. Scaling function of critical binary mixtures: Nitrobenzene- n-hexane data revisited

    Science.gov (United States)

    Mirzaev, Sirojiddin Z.; Kaatze, Udo

    2012-01-01

    Ultrasonic attenuation spectra of the nitrobenzene- n-hexane mixture of critical composition have been analysed. Data between 50 kHz and 1 GHz from different sources have been included to show that at a given temperature the spectra, in addition to the critical contribution, reveal a non-critical relaxation term. Taking this additional term into account inconsistencies in the scaling function reported in the literature are avoided. In the final analysis the scaling function of the nitrobenzene- n-hexane system follows the predictions of the Bhattacharjee-Ferrell theory with critical amplitude and relaxation rate of concentration fluctuations in nice agreement with determinations from independent methods. The low-frequency attenuation data are briefly discussed with a view to a bulk viscosity approach which yields a slightly different proportionality constant in the linear regime of the scaling function than the Bhattacharjee-Ferrell theory. Evidence in favour of the latter is obtained.

  19. The critical role of catalase in prooxidant and antioxidant function of p53

    Science.gov (United States)

    Kang, M Y; Kim, H-B; Piao, C; Lee, K H; Hyun, J W; Chang, I-Y; You, H J

    2013-01-01

    The tumor suppressor p53 is an important regulator of intracellular reactive oxygen species (ROS) levels, although downstream mediators of p53 remain to be elucidated. Here, we show that p53 and its downstream targets, p53-inducible ribonucleotide reductase (p53R2) and p53-inducible gene 3 (PIG3), physically and functionally interact with catalase for efficient regulation of intracellular ROS, depending on stress intensity. Under physiological conditions, the antioxidant functions of p53 are mediated by p53R2, which maintains increased catalase activity and thereby protects against endogenous ROS. After genotoxic stress, high levels of p53 and PIG3 cooperate to inhibit catalase activity, leading to a shift in the oxidant/antioxidant balance toward an oxidative status, which could augment apoptotic cell death. These results highlight the essential role of catalase in p53-mediated ROS regulation and suggest that the p53/p53R2–catalase and p53/PIG3–catalase pathways are critically involved in intracellular ROS regulation under physiological conditions and during the response to DNA damage, respectively. PMID:22918438

  20. A Critical Role of IL-21-Induced BATF in Sustaining CD8-T-Cell-Mediated Chronic Viral Control

    Directory of Open Access Journals (Sweden)

    Gang Xin

    2015-11-01

    Full Text Available Control of chronic viral infections by CD8 T cells is critically dependent on CD4 help. In particular, helper-derived IL-21 plays a key role in sustaining the CD8 T cell response; however, the molecular pathways by which IL-21 sustains CD8 T cell immunity remain unclear. We demonstrate that IL-21 causes a phenotypic switch of transcription factor expression in CD8 T cells during chronic viral infection characterized by sustained BATF expression. Importantly, BATF expression during chronic infection is both required for optimal CD8 T cell persistence and anti-viral effector function and sufficient to rescue “unhelped” CD8 T cells. Mechanistically, BATF sustains the response by cooperating with IRF4, an antigen-induced transcription factor that is also critically required for CD8 T cell maintenance, to preserve Blimp-1 expression and thereby sustain CD8 T cell effector function. Collectively, these data suggest that CD4 T cells “help” the CD8 response during chronic infection via IL-21-induced BATF expression.

  1. Functions of proteoglycans at the cell surface

    DEFF Research Database (Denmark)

    Höök, M; Woods, A; Johansson, S

    1986-01-01

    sulphate helps to connect the intracellular cytoskeleton to the extracellular matrix in focal adhesions. This evidence includes: the co-localization of actin and heparan sulphate proteoglycan during the process of cell spreading, and in isolated focal adhesions; biochemical analyses of a hydrophobic......Proteoglycans (primarily heparan sulphate proteoglycans) are found at the surface of most adherent eukaryotic cells. Earlier studies suggest that these molecules can be associated with the cell surface principally by two different mechanisms. Proteoglycans may occur as membrane......-intercalated glycoproteins, where the core protein of the proteoglycan is anchored in the lipid interior of the plasma membrane, or they may be bound via the polysaccharide components of the molecule to specific anchoring proteins present at the cell surface. A number of functions have been proposed for cell surface...

  2. TLR4 signalling in pulmonary stromal cells is critical for inflammation and immunity in the airways.

    Science.gov (United States)

    Perros, Frederic; Lambrecht, Bart N; Hammad, Hamida

    2011-09-24

    Inflammation of the airways, which is often associated with life-threatening infection by Gram-negative bacteria or presence of endotoxin in the bioaerosol, is still a major cause of severe airway diseases. Moreover, inhaled endotoxin may play an important role in the development and progression of airway inflammation in asthma. Pathologic changes induced by endotoxin inhalation include bronchospasm, airflow obstruction, recruitment of inflammatory cells, injury of the alveolar epithelium, and disruption of pulmonary capillary integrity leading to protein rich fluid leak in the alveolar space. Mammalian Toll-like receptors (TLRs) are important signalling receptors in innate host defense. Among these receptors, TLR4 plays a critical role in the response to endotoxin. Lungs are a complex compartmentalized organ with separate barriers, namely the alveolar-capillary barrier, the microvascular endothelium, and the alveolar epithelium. An emerging theme in the field of lung immunology is that structural cells (SCs) of the airways such as epithelial cells (ECs), endothelial cells, fibroblasts and other stromal cells produce activating cytokines that determine the quantity and quality of the lung immune response. This review focuses on the role of TLR4 in the innate and adaptive immune functions of the pulmonary SCs.

  3. Regulation of T cell differentiation and function by EZH2

    Directory of Open Access Journals (Sweden)

    THEODOROS KARANTANOS

    2016-05-01

    Full Text Available The enhancer of zeste homologue 2 (EZH2, one of the polycomb group (PcG proteins, is the catalytic subunit of Polycomb-repressive complex 2 (PRC2 and induces the trimethylation of the histone H3 lysine 27 (H3K27me3 promoting epigenetic gene silencing. EZH2 contains a SET domain promoting the methyltransferase activity while the three other protein components of PRC2, namely EED, SUZ12 and RpAp46/48 induce compaction of the chromatin permitting EZH2 enzymatic activity. Numerous studies highlight the role of this evolutionary conserved protein as a master regulator of differentiation in humans involved in the repression of the homeotic (Hox gene and the inactivation of X-chromosome. Through its effects in the epigenetic regulation of critical genes, EZH2 has been strongly linked to cell cycle progression, stem cell pluripotency and cancer biology. Most recently, EZH2 has been associated with hematopoietic stem cell proliferation and differentiation, thymopoiesis and lymphopoiesis. Several studies have evaluated the role of EZH2 in the regulation of T cell differentiation and plasticity as well as its implications in the development of autoimmune diseases and graft versus host disease (GvHD. In this review we will briefly summarize the current knowledge regarding the role of EZH2 in the regulation of T cell differentiation, effector function and homing in the tumor microenvironment and we will discuss possible therapeutic targeting of EZH2 in order to alter T cell immune functions.

  4. Critical factors affecting cell encapsulation in superporous hydrogels

    International Nuclear Information System (INIS)

    Desai, Esha S; Tang, Mary Y; Gemeinhart, Richard A; Ross, Amy E

    2012-01-01

    We recently showed that superporous hydrogel (SPH) scaffolds promote long-term stem cell viability and cell driven mineralization when cells were seeded within the pores of pre-fabricated SPH scaffolds. The possibility of cell encapsulation within the SPH matrix during its fabrication was further explored in this study. The impact of each chemical component used in SPH fabrication and each step of the fabrication process on cell viability was systematically examined. Ammonium persulfate, an initiator, and sodium bicarbonate, the gas-generating compound, were the two components having significant toxicity toward encapsulated cells at the concentrations necessary for SPH fabrication. Cell survival rates were 55.7% ± 19.3% and 88.8% ± 9.4% after 10 min exposure to ammonium persulfate and sodium bicarbonate solutions, respectively. In addition, solution pH change via the addition of sodium bicarbonate had significant toxicity toward encapsulated cells with cell survival of only 50.3% ± 2.5%. Despite toxicity of chemical components and the SPH fabrication method, cells still exhibited significant overall survival rates within SPHs of 81.2% ± 6.8% and 67.0% ± 0.9%, respectively, 48 and 72 h after encapsulation. This method of cell encapsulation holds promise for use in vitro and in vivo as a scaffold material for both hydrogel matrix encapsulation and cell seeding within the pores. (paper)

  5. The critical role of Golgi cells in regulating spatio-temporal integration and plasticity at the cerebellum input stage

    Directory of Open Access Journals (Sweden)

    2008-07-01

    Full Text Available After the discovery at the end of the 19th century (Golgi, 1883, the Golgi cell was precisely described by S.R. y Cajal (see Cajal, 1987, 1995 and functionally identified as an inhibitory interneuron 50 years later by J.C. Eccles and colleagues (Eccles e al., 1967. Then, its role has been casted by Marr (1969 within the Motor Learning Theory as a codon size regulator of granule cell activity. It was immediately clear that Golgi cells had to play a critical role, since they are the main inhibitory interneuron of the granular layer and control activity of as many as 100 millions granule cells. In vitro, Golgi cells show pacemaking, resonance, phase-reset and rebound-excitation in the theta-frequency band. These properties are likely to impact on their activity in vivo, which shows irregular spontaneous beating modulated by sensory inputs and burst responses to punctuate stimulation followed by a silent pause. Moreover, investigations have given insight into Golgi cells connectivity within the cerebellar network and on their impact on the spatio-temporal organization of activity. It turns out that Golgi cells can control both the temporal dynamics and the spatial distribution of information transmitted through the cerebellar network. Moreover, Golgi cells regulate the induction of long-term synaptic plasticity at the mossy fiber - granule cell synapse. Thus, the concept is emerging that Golgi cells are of critical importance for regulating granular layer network activity bearing important consequences for cerebellar computation as a whole.

  6. Development of Functional Microfold (M Cells from Intestinal Stem Cells in Primary Human Enteroids.

    Directory of Open Access Journals (Sweden)

    Joshua D Rouch

    Full Text Available Intestinal microfold (M cells are specialized epithelial cells that act as gatekeepers of luminal antigens in the intestinal tract. They play a critical role in the intestinal mucosal immune response through transport of viruses, bacteria and other particles and antigens across the epithelium to immune cells within Peyer's patch regions and other mucosal sites. Recent studies in mice have demonstrated that M cells are generated from Lgr5+ intestinal stem cells (ISCs, and that infection with Salmonella enterica serovar Typhimurium increases M cell formation. However, it is not known whether and how these findings apply to primary human small intestinal epithelium propagated in an in vitro setting.Human intestinal crypts were grown as monolayers with growth factors and treated with recombinant RANKL, and assessed for mRNA transcripts, immunofluorescence and uptake of microparticles and S. Typhimurium.Functional M cells were generated by short-term culture of freshly isolated human intestinal crypts in a dose- and time-dependent fashion. RANKL stimulation of the monolayer cultures caused dramatic induction of the M cell-specific markers, SPIB, and Glycoprotein-2 (GP2 in a process primed by canonical WNT signaling. Confocal microscopy demonstrated a pseudopod phenotype of GP2-positive M cells that preferentially take up microparticles. Furthermore, infection of the M cell-enriched cultures with the M cell-tropic enteric pathogen, S. Typhimurium, led to preferential association of the bacteria with M cells, particularly at lower inoculum sizes. Larger inocula caused rapid induction of M cells.Human intestinal crypts containing ISCs can be cultured and differentiate into an epithelial layer with functional M cells with characteristic morphological and functional properties. This study is the first to demonstrate that M cells can be induced to form from primary human intestinal epithelium, and that S. Typhimurium preferentially infect these cells in an

  7. Mycobacteria and innate cells: critical encounter for immunogenicity

    Indian Academy of Sciences (India)

    PRAKASH KUMAR G

    19 kDa lipoprotein induces apoptosis in human monocyte- derived macrophages (MDMs) in a dose-dependent ... THP-1 (human promonocytic) cell line (Lopez et al 2003). Indeed, after infection with MTB and BCG ..... Hayday A C 2000 γδ cells: a right time and a right place for a conserved third way of protection; Annu. Rev.

  8. Mycobacteria and innate cells: critical encounter for immunogenicity

    Indian Academy of Sciences (India)

    Protective immunity against mycobacterial infections such as Mycobacterium tuberculosis is mediated by interactions between specific T cells and activated macrophages. To date, many aspects of mycobacterial immunity have shown that innate cells are the key elements that substantially influence the subsequent adaptive ...

  9. Macrophage Clearance of Apoptotic Cells: A Critical Assessment

    Directory of Open Access Journals (Sweden)

    Siamon Gordon

    2018-01-01

    Full Text Available As the body continues to grow and age, it becomes essential to maintain a balance between living and dying cells. Macrophages and dendritic cells play a central role in discriminating among viable, apoptotic, and necrotic cells, as selective and efficient phagocytes, without inducing inappropriate inflammation or immune responses. A great deal has been learnt concerning clearance receptors for modified and non-self-ligands on potential targets, mediating their eventual uptake, disposal, and replacement. In this essay, we assess current understanding of the phagocytic recognition of apoptotic cells within their tissue environment; we conclude that efferocytosis constitutes a more complex process than simply removal of corpses, with regulatory interactions between the target and effector cells, which determine the outcome of this homeostatic process.

  10. Critical kinetic control of non-stoichiometric intermediate phase transformation for efficient perovskite solar cells

    Science.gov (United States)

    Rong, Yaoguang; Venkatesan, Swaminathan; Guo, Rui; Wang, Yanan; Bao, Jiming; Li, Wenzhi; Fan, Zhiyong; Yao, Yan

    2016-06-01

    Organometal trihalide perovskites (OTP) have attracted significant attention as a low-cost and high-efficiency solar cell material. Due to the strong coordination between lead iodide (PbI2) and dimethyl sulfoxide (DMSO) solvent, a non-stoichiometric intermediate phase of MA2Pb3I8(DMSO)2 (MA = CH3NH3+) usually forms in the one-step deposition method that plays a critical role in attaining high power conversion efficiency. However, the kinetic understanding of how the non-stoichiometric intermediate phase transforms during thermal annealing is currently absent. In this work, we investigated such a phase transformation and provided a clear picture of three phase transition pathways as a function of annealing conditions. The interdiffusion of MAI and DMSO varies strongly with the annealing temperature and time, thus determining the final film composition and morphology. A surprising finding reveals that the best performing cells contain ~18% of the non-stoichiometric intermediate phase, instead of pure phase OTP. The presence of such an intermediate phase enables smooth surface morphology and enhances the charge carrier lifetime. Our results highlight the importance of the intermediate phase growth kinetics that could lead to large-scale production of efficient solution processed perovskite solar cells.Organometal trihalide perovskites (OTP) have attracted significant attention as a low-cost and high-efficiency solar cell material. Due to the strong coordination between lead iodide (PbI2) and dimethyl sulfoxide (DMSO) solvent, a non-stoichiometric intermediate phase of MA2Pb3I8(DMSO)2 (MA = CH3NH3+) usually forms in the one-step deposition method that plays a critical role in attaining high power conversion efficiency. However, the kinetic understanding of how the non-stoichiometric intermediate phase transforms during thermal annealing is currently absent. In this work, we investigated such a phase transformation and provided a clear picture of three phase transition

  11. Modelling of critical functions of nuclear reactors using Fild Programmable Gate Array

    International Nuclear Information System (INIS)

    Teixeira, Pamela Iara Nolasco

    2016-01-01

    This paper proposes the development of a method using FPGA for critical security functions of a nuclear reactor. It was implemented two critical safety functions in VHDL, which is a way to describe, through a program, the behavior of a circuit or digital component. Two critical security functions, FCS Core Cooling, responsible for cooling the reactor core in the charts of the plant and also in the event of accidents involving loss of coolant and FCS Heat Transfer, responsible for cooling the reactor core in the event an accident with loss of coolant were implemented. In this Dissertation it was chosen the use of FPGA, because - due to the effects of aging, obsolescence issues, environmental degradation and mechanical failures - nuclear power plants need to replace their older systems by new ones based on digital technology. The technologies obtained using a system described in hardware language can be implemented in a programmable device, having the advantage of changing the code at any time. (author)

  12. T Cell factor 1 represses CD8+ effector T cell formation and function.

    Science.gov (United States)

    Tiemessen, Machteld M; Baert, Miranda R M; Kok, Lianne; van Eggermond, Marja C J A; van den Elsen, Peter J; Arens, Ramon; Staal, Frank J T

    2014-12-01

    The Wnt-responsive transcription factor T cell factor 1 (Tcf1) is well known for its role in thymic T cell development and the formation of memory CD8(+) T cells. However, its role in the initial phases of CD8(+) T effector cell formation has remained unexplored. We report that high levels of Wnt signaling and Tcf1 are operational in naive and memory CD8(+) T cells, whereas Wnt signaling and Tcf1 were low in effector CD8(+) T cells. CD8(+) T cells deficient in Tcf1 produce IFN-γ more rapidly, coinciding with increased demethylation of the IFN-γ enhancer and higher expression of the transcription factors Tbet and Blimp1. Moreover, virus-specific Tcf1(-/-) CD8(+) T cells show accelerated expansion in acute infection, which is associated with increased IFN-γ and TNF production and lower viral load. Genetic complementation experiments with various Tcf1 isoforms indicate that Tcf1 dosage and protein stability are critical in suppressing IFN-γ production. Isoforms lacking the β-catenin binding domain are equally effective in inhibiting CD8(+) effector T cell formation. Thus, Tcf1 functions as a repressor of CD8(+) effector T cell formation in a β-catenin/Wnt-independent manner. Copyright © 2014 by The American Association of Immunologists, Inc.

  13. Osteochondral tissue engineering for total joint repair critical steps towards cell based constructs

    NARCIS (Netherlands)

    Hamann, D.

    2008-01-01

    This thesis identifies critical steps to be taken to develop osteochondral constructs. One of the most significant steps in cell-based tissue engineering (TE) is efficient and effective cell seeding. The application of multipotent mesenchymal stem cells (MSCs) is a major advantage for bone and

  14. Slp-76 is a critical determinant of NK-cell mediated recognition of missing-self targets.

    Science.gov (United States)

    Lampe, Kristin; Endale, Mehari; Cashman, Siobhan; Fang, Hao; Mattner, Jochen; Hildeman, David; Hoebe, Kasper

    2015-07-01

    Absence of MHC class I expression is an important mechanism by which NK cells recognize a variety of target cells, yet the pathways underlying "missing-self" recognition, including the involvement of activating receptors, remain poorly understood. Using ethyl-N-nitrosourea mutagenesis in mice, we identified a germline mutant, designated Ace, with a marked defect in NK cell mediated recognition and elimination of "missing-self" targets. The causative mutation was linked to chromosome 11 and identified as a missense mutation (Thr428Ile) in the SH2 domain of Slp-76-a critical adapter molecule downstream of ITAM-containing surface receptors. The Slp-76 Ace mutation behaved as a hypomorphic allele-while no major defects were observed in conventional T-cell development/function, a marked defect in NK cell mediated elimination of β2-microglobulin (β2M) deficient target cells was observed. Further studies revealed Slp-76 to control NK-cell receptor expression and maturation; however, activation of Slp-76(ace/ace) NK cells through ITAM-containing NK-cell receptors or allogeneic/tumor target cells appeared largely unaffected. Imagestream analysis of the NK-β2M(-/-) target cell synapse revealed a specific defect in actin recruitment to the conjugate synapse in Slp-76(ace/ace) NK cells. Overall these studies establish Slp-76 as a critical determinant of NK-cell development and NK cell mediated elimination of missing-self target cells in mice. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. A strategy for minimizing common mode human error in executing critical functions and tasks

    International Nuclear Information System (INIS)

    Beltracchi, L.; Lindsay, R.W.

    1992-01-01

    Human error in execution of critical functions and tasks can be costly. The Three Mile Island and the Chernobyl Accidents are examples of results from human error in the nuclear industry. There are similar errors that could no doubt be cited from other industries. This paper discusses a strategy to minimize common mode human error in the execution of critical functions and tasks. The strategy consists of the use of human redundancy, and also diversity in human cognitive behavior: skill-, rule-, and knowledge-based behavior. The authors contend that the use of diversity in human cognitive behavior is possible, and it minimizes common mode error

  16. Schwann cell myelination requires Dynein function

    Directory of Open Access Journals (Sweden)

    Langworthy Melissa M

    2012-11-01

    Full Text Available Abstract Background Interaction of Schwann cells with axons triggers signal transduction that drives expression of Pou3f1 and Egr2 transcription factors, which in turn promote myelination. Signal transduction appears to be mediated, at least in part, by cyclic adenosine monophosphate (cAMP because elevation of cAMP levels can stimulate myelination in the absence of axon contact. The mechanisms by which the myelinating signal is conveyed remain unclear. Results By analyzing mutations that disrupt myelination in zebrafish, we learned that Dynein cytoplasmic 1 heavy chain 1 (Dync1h1, which functions as a motor for intracellular molecular trafficking, is required for peripheral myelination. In dync1h1 mutants, Schwann cell progenitors migrated to peripheral nerves but then failed to express Pou3f1 and Egr2 or make myelin membrane. Genetic mosaic experiments revealed that robust Myelin Basic Protein expression required Dync1h1 function within both Schwann cells and axons. Finally, treatment of dync1h1 mutants with a drug to elevate cAMP levels stimulated myelin gene expression. Conclusion Dync1h1 is required for retrograde transport in axons and mutations of Dync1h1 have been implicated in axon disease. Our data now provide evidence that Dync1h1 is also required for efficient myelination of peripheral axons by Schwann cells, perhaps by facilitating signal transduction necessary for myelination.

  17. FOXO1 transcription factor: a critical effector of the PI3K-AKT axis in B-cell development.

    Science.gov (United States)

    Szydłowski, Maciej; Jabłońska, Ewa; Juszczyński, Przemysław

    2014-03-01

    B-cell development and differentiation are controlled at multiple levels by the complex interplay of specific receptors and a variety of transcription factors. Several receptors involved in regulating this process, such as IL-7R, pre-B cell receptor (pre-BCR), and BCR, share the ability to trigger the signaling via the phosphoinositide 3-kinase (PI3K)-AKT pathway. FOXO1 transcription factor, a major PI3K-AKT downstream effector, regulates the expression of genes critical for progress through consecutive steps of B-cell differentiation. FOXO1 directs or fine-tunes multiple biological functions that are crucial for differentiating cells, including the cell cycle, apoptosis, oxidative stress response or DNA damage repair. Recent studies have highlighted the key role that FOXO1 plays in the maintenance of the hematopoietic stem cell pool, regulation of progenitor commitment, development of early B-cell precursors, induction of B-cell tolerance, peripheral B-cell homeostasis, and terminal differentiation. FOXO1 deficiency impairs B-cell development, due to decreased expression of its critical target genes, that include early B-cell factor (EBF1), IL-7 receptor, recombination activating genes (RAG1 and 2), activation-induced cytidine deaminase (AID), L-selectin, and BLNK. Taken together, FOXO1 is an important node in a dynamic network of transcription factors that orchestrate B-cell differentiation and specialization. Herein, we review molecular mechanisms of the PI3K-AKT-dependent signal transduction and their impact on early B-cell development, peripheral B-cell homeostasis, and terminal differentiation.

  18. Evaluating Which Dose-Function Metrics Are Most Critical for Functional-Guided Radiation Therapy.

    Science.gov (United States)

    Faught, Austin M; Yamamoto, Tokihiro; Castillo, Richard; Castillo, Edward; Zhang, Jingjing; Miften, Moyed; Vinogradskiy, Yevgeniy

    2017-09-01

    Four-dimensional (4D) computed tomography (CT) ventilation imaging is increasingly being used to calculate lung ventilation and implement functional-guided radiation therapy in clinical trials. There has been little exhaustive work evaluating which dose-function metrics should be used for treatment planning and plan evaluation. The purpose of our study was to evaluate which dose-function metrics best predict for radiation pneumonitis (RP). Seventy lung cancer patients who underwent 4D CT imaging and pneumonitis grading were assessed. Pretreatment 4D CT scans of each patient were used to calculate ventilation images. We evaluated 3 types of dose-function metrics that combined the patient's 4D CT ventilation image and treatment planning dose distribution: (1) structure-based approaches; (2) image-based approaches using the dose-function histogram; and (3) nonlinear weighting schemes. Log-likelihood methods were used to generate normal tissue complication probability models predicting grade 3 or higher (ie, grade 3+) pneumonitis for all dose-function schemes. The area under the curve (AUC) was used to assess the predictive power of the models. All techniques were compared with normal tissue complication probability models based on traditional, total lung dose metrics. The most predictive models were structure-based approaches that focused on the volume of functional lung receiving ≥20 Gy (AUC, 0.70). Probabilities of grade 3+ RP of 20% and 10% correspond to V20 (percentage of volume receiving ≥20 Gy) to the functional subvolumes of 26.8% and 9.3%, respectively. Imaging-based analysis with the dose-function histogram and nonlinear weighted ventilation values yielded AUCs of 0.66 and 0.67, respectively, when we evaluated the percentage of functionality receiving ≥20 Gy. All dose-function metrics outperformed the traditional dose metrics (mean lung dose, AUC of 0.55). A full range of dose-function metrics and functional thresholds was examined. The

  19. A three critical point theorem for non-smooth functionals with ...

    Indian Academy of Sciences (India)

    application. DEFINITION 2.4. Assume. : X → R is a locally Lipschitz function. A vector u ∈ X is said to be a critical point of the functional if 0 ∈ ∂ (u), that is, ..... Then, from (3.5) we easily get for n ∈ N big enough 〈I′(un), un − u〉 < ε, that is, ... Let us introduce the data of our problem: let 1

  20. Allogeneic stem cell transplantation for myelodysplastic syndromes: critical for cure?

    NARCIS (Netherlands)

    Witte, T.J.M. de

    2011-01-01

    Allogeneic stem cell transplantation (SCT) is the treatment of choice for young patients (age

  1. Using Digital Comics to Develop Digital Literacy: Fostering Functionally, Critically, and Rhetorically Literate Students

    Science.gov (United States)

    Kirchoff, Jeff

    2017-01-01

    Literacy scholarship has established the importance of teaching, supporting, and facilitating digital literacy education for 21st century students. Stuart Selber goes a step further, arguing that students must be functionally (using digital technology), critically (questioning digital technology), and rhetorically (producing effective digital…

  2. Validation of the Dutch functional, communicative and critical health literacy scales

    NARCIS (Netherlands)

    van der Vaart, R.; Drossaert, Constance H.C.; Taal, Erik; ten Klooster, Peter M.; Hilderink-Koertshuis, Rianne T.E.; Klaase, Joost M.; van de Laar, Mart A F J

    2012-01-01

    Objective: While most existing health literacy (HL) measures focus primarily on reading comprehension, the functional, communicative and critical HL scales from Ishikawa et al. [19] aim to measure a broader HL spectrum. The objective of this study was to evaluate the validity of the Dutch

  3. Critical dimension of bosonic string theory and zeta-function regularization

    International Nuclear Information System (INIS)

    Vanzo, L.; Zerbini, S.; Istituto Nazionale di Fisica Nucleare, Povo

    1988-01-01

    A derivation of the critical dimension of the Polyakov bosonic string is presented. It is based on the use of the anholonomic formalism, a ghost-anti-ghost symmetric action, zeta-function regularization and the Seeley method of pseudo-differential operators. (orig.)

  4. A three critical point theorem for non-smooth functionals with ...

    Indian Academy of Sciences (India)

    ... non-smooth functionals and by a few hypotheses, without any minimax inequality, the existence of at least three critical points with a uniform bound on the norms of solutions, is obtained. Also, as an application, our main theorem is used to obtain at least three anti-periodic solutions for a second order differential inclusion.

  5. A Rapid Culture Technique Produces Functional Dendritic-Like Cells from Human Acute Myeloid Leukemia Cell Lines

    Directory of Open Access Journals (Sweden)

    Jian Ning

    2011-01-01

    Full Text Available Most anti-cancer immunotherapeutic strategies involving dendritic cells (DC as vaccines rely upon the adoptive transfer of DC loaded with exogenous tumour-peptides. This study utilized human acute myeloid leukemia (AML cells as progenitors from which functional dendritic-like antigen presenting cells (DLC were generated, that constitutively express tumour antigens for recognition by CD8+ T cells. DLC were generated from AML cell lines KG-1 and MUTZ-3 using rapid culture techniques and appropriate cytokines. DLC were evaluated for their cell-surface phenotype, antigen uptake and ability to stimulate allogeneic responder cell proliferation, and production of IFN-γ; compared with DC derived from normal human PBMC donors. KG-1 and MUTZ-3 DLC increased expression of CD80, CD83, CD86, and HLA-DR, and MUTZ-3 DLC downregulated CD14 and expressed CD1a. Importantly, both KG-1 and MUTZ-3-derived DLC promoted proliferation of allogeneic responder cells more efficiently than unmodified cells; neither cells incorporated FITC-labeled dextran, but both stimulated IFN-γ production from responding allogeneic CD8+ T cells. Control DC produced from PBMC using the FastDC culture also expressed high levels of critical cell surface ligands and demonstrated good APC function. This paper indicates that functional DLC can be cultured from the AML cell lines KG-1 and MUTZ-3, and FastDC culture generates functional KG-1 DLC.

  6. Platelet-Derived Growth Factor Receptor-Positive Pericytic Cells of White Adipose Tissue from Critical Limb Ischemia Patients Display Mesenchymal Stem Cell-Like Properties.

    Science.gov (United States)

    Kim, Eo Jin; Seo, Sang Gyo; Shin, Hyuk Soo; Lee, Doo Jae; Kim, Ji Hye; Lee, Dong Yeon

    2017-06-01

    The pericytes in the blood vessel wall have recently been identified to be important in regulating vascular formation, stabilization, remodeling, and function. We isolated and identified pericyte-like platelet-derived growth factor receptor beta-positive (PDGFRβ+) cells from the stromal vascular fraction (SVF) of adipose tissue from critical limb ischemia (CLI) patients and investigated their potential as a reliable source of stem cells for cell-based therapy. De-identified subcutaneous fat tissues were harvested after amputation in CLI patients. Freshly isolated SVF cells and culture-expanded adipose-derived stem cells (ADSCs) were quantified using flow cytometry. A matrigel tube formation assay and multi-lineage differentiation were performed to assess pericytic and mesenchymal stem cell (MSC)-like characteristics of PDGFRβ+ ADSCs. PDGFRβ+ cells were located in the pericytic area of various sizes of blood vessels and coexpressed mesenchymal stem cell markers. PDGFRβ+ cells in freshly isolated SVF cells expressed a higher level of stem cell markers (CD34 and CXCR4) and mesenchymal markers (CD13, CD44, CD54, and CD90) than PDGFRβ- cells. In vitro expansion of PDGFRβ+ cells resulted in enrichment of the perivascular mesenchymal stem-like (PDGFRβ+/CD90+/CD45-/CD31-) cell fractions. The Matrigel tube formation assay revealed that PDGFRβ+ cells were located in the peritubular area. PDGFRβ+ ADSCs cells demonstrated a good multilineage differentiation potential. Pericyte-like PDGFRβ+ cells from the SVF of adipose tissue from CLI patients had MSC-like characteristics and could be amplified by in vitro culture with preservation of their cell characteristics. We believe PDGFRβ+ cells in the SVF of adipose tissue can be used as a reliable source of stem cells even in CLI patients.

  7. Runx-dependent expression of PKC is critical for cell survival in the sea urchin embryo

    Directory of Open Access Journals (Sweden)

    McCarthy John J

    2005-08-01

    Full Text Available Abstract Background Runx transcription factors play critical roles in the developmental control of cell fate and contribute variously as oncoproteins and tumor suppressors to leukemia and other cancers. To discover fundamental Runx functions in the cell biology of animal development, we have employed morpholino antisense-mediated knockdown of the sea urchin Runx protein SpRunt-1. Previously we showed that embryos depleted of SpRunt-1 arrest development at early gastrula stage and underexpress the conventional protein kinase C SpPKC1. Results We report here that SpRunt-1 deficiency leads to ectopic cell proliferation and extensive apoptosis. Suppression of the apoptosis by pharmacological inhibition of caspase-3 prevents the ectopic proliferation and rescues gastrulation, indicating that many of the overt defects obtained by knockdown of SpRunt-1 are secondary to the apoptosis. Inhibition or knockdown of SpPKC1 also causes apoptosis, while cell survival is rescued in SpRunt-1 morphant embryos coinjected with SpPKC1 mRNA, suggesting that the apoptosis associated with SpRunt-1 deficiency is caused by the deficit in SpPKC1 expression. Chromatin immunoprecipitation indicates that SpRunt-1 interacts physically with SpPKC1 in vivo, and cis-regulatory analysis shows that this interaction activates SpPKC1 transcription. Conclusions Our results show that Runx-dependent activation of SpPKC1 is essential for maintaining protein kinase C activity at levels conducive to cell survival during embryogenesis.

  8. Skeletal Muscle Ultrasonography in Nutrition and Functional Outcome Assessment of Critically Ill Children: Experience and Insights From Pediatric Disease and Adult Critical Care Studies [Formula: see text].

    Science.gov (United States)

    Ong, Chengsi; Lee, Jan Hau; Leow, Melvin K S; Puthucheary, Zudin A

    2017-09-01

    Evidence suggests that critically ill children develop muscle wasting, which could affect outcomes. Muscle ultrasound has been used to track muscle wasting and association with outcomes in critically ill adults but not children. This review aims to summarize methodological considerations of muscle ultrasound, structural findings, and possibilities for its application in the assessment of nutrition and functional outcomes in critically ill children. Medline, Embase, and CINAHL databases were searched up until April 2016. Articles describing skeletal muscle ultrasound in children and critically ill adults were analyzed qualitatively for details on techniques and findings. Thickness and cross-sectional area of various upper and lower body muscles have been studied to quantify muscle mass and detect muscle changes. The quadriceps femoris muscle is one of the most commonly measured muscles due to its relation to mobility and is sensitive to changes over time. However, the margin of error for quadriceps thickness is too wide to reliably detect muscle changes in critically ill children. Muscle size and its correlation with strength and function also have not yet been studied in critically ill children. Echogenicity, used to detect compromised muscle structure in neuromuscular disease, may be another property worth studying in critically ill children. Muscle ultrasound may be useful in detecting muscle wasting in critically ill children but has not been shown to be sufficiently reliable in this population. Further study of the reliability and correlation with functional outcomes and nutrition intake is required before muscle ultrasound is routinely employed in critically ill children.

  9. Allogeneic stem cell transplantation for myelodysplastic syndromes: critical for cure?

    Science.gov (United States)

    de Witte, Theo

    2011-06-01

    Allogeneic stem cell transplantation (SCT) is the treatment of choice for young patients (age ≤ 55 years) with myelodysplastic syndromes (MDS) characterized by poor-risk or intermediate-risk cytogenetics, who have a histocompatible related or unrelated donor. For patients who lack an human leukocyte antigen-compatible donor, autologous SCT, or chemotherapy may be good alternatives for those with MDS and with good-risk cytogenetic characteristics. Iron toxicity is an underestimated cause of hematopoietic stem cell transplantation (HSCT) treatment-related mortality. The pathogenesis, diagnosis, and monitoring of iron-induced organ damage are currently topics of investigation. Prospective studies on the prevention or treatment of iron toxicity before HSCT and/or after HSCT are necessary. Copyright © 2011. Published by Elsevier Inc.

  10. Hair follicle stem cells provide a functional niche for melanocyte stem cells.

    Science.gov (United States)

    Tanimura, Shintaro; Tadokoro, Yuko; Inomata, Ken; Binh, Nguyen Thanh; Nishie, Wataru; Yamazaki, Satoshi; Nakauchi, Hiromitsu; Tanaka, Yoshio; McMillan, James R; Sawamura, Daisuke; Yancey, Kim; Shimizu, Hiroshi; Nishimura, Emi K

    2011-02-04

    In most stem cell systems, the organization of the stem cell niche and the anchoring matrix required for stem cell maintenance are largely unknown. We report here that collagen XVII (COL17A1/BP180/BPAG2), a hemidesmosomal transmembrane collagen, is highly expressed in hair follicle stem cells (HFSCs) and is required for the maintenance not only of HFSCs but also of melanocyte stem cells (MSCs), which do not express Col17a1 but directly adhere to HFSCs. Mice lacking Col17a1 show premature hair graying and hair loss. Analysis of Col17a1-null mice revealed that COL17A1 is critical for the self-renewal of HFSCs through maintaining their quiescence and immaturity, potentially explaining the mechanism underlying hair loss in human COL17A1 deficiency. Moreover, forced expression of COL17A1 in basal keratinocytes, including HFSCs, in Col17a1-null mice rescues MSCs from premature differentiation and restores TGF-β signaling, demonstrating that HFSCs function as a critical regulatory component of the MSC niche. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. An Update on the Effect of Incretin-Based Therapies on ?-Cell Function and Mass

    OpenAIRE

    Chon, Suk; Gautier, Jean-Fran?ois

    2016-01-01

    Type 2 diabetes mellitus (T2DM) is a multifactorial disease with a complex and progressive pathogenesis. The two primary mechanisms of T2DM pathogenesis are pancreatic ?-cell dysfunction and insulin resistance. Pancreatic ?-cell dysfunction is recognized to be a prerequisite for the development of T2DM. Therapeutic modalities that improve ?-cell function are considered critical to T2DM management; however, blood glucose control remains a challenge for many patients due to suboptimal treatment...

  12. Impact of MAPK Pathway Activation in BRAFV600 Melanoma on T Cell and Dendritic Cell Function

    Directory of Open Access Journals (Sweden)

    Patrick A. Ott

    2013-10-01

    Full Text Available Constitutive upregulation of the MAPK pathway by a BRAFV600 mutation occurs in about half of melanomas. This leads to increased oncogenic properties such as tumor cell invasion, metastatic potential, and resistance to apoptosis. Blockade of the MAPK pathway with highly specific kinase inhibitors induces unprecedented tumor response rates in patients with advanced BRAFV600 mutant melanoma. Immune checkpoint blockade with monoclonal antibodies targeting cytotoxic T-lymphocyte antigen 4 and programed death-1/PD-L1 has also demonstrated striking anti-tumor activity in patients with advanced melanoma. Tumor responses are likely limited by multiple additional layers of immune suppression in the tumor microenvironment. There is emerging preclinical and clinical evidence suggesting that MAPK inhibition has a beneficial effect on the immunosuppressive tumor microenvironment, providing a strong rationale for combined immunotherapy and MAPK pathway inhibition in melanoma. The T cell response has been the main focus in the studies reported to date. Since dendritic cells (DCs are important in the induction of tumor-specific T cell responses, the impact of MAPK pathway activation in melanoma on DC function is critical for the melanoma directed immune response. BRAFV600E melanoma cells modulate DCs through the MAPK pathway because its blockade in melanoma cells can reverse suppression of DC function. As both MEK/BRAF inhibition and immune checkpoint blockade have recently taken center stage in the treatment of melanoma, a deeper understanding of how MAPK pathway inhibition affects the tumor immune response is needed.

  13. Ultrasound for critical care physicians: sickle cell crisis

    Directory of Open Access Journals (Sweden)

    Raschke RA

    2013-08-01

    Full Text Available No abstract available. Article truncated after first page. A 32 year old man was admitted a week earlier with sickle cell pain crisis. He had developed increasing dyspnea, oxygen desaturation and bilateral pulmonary infiltrates. He had a pulseless electric activity code blue and an ultrasound of the heart was obtained (Figure 1. Figure 1. Subxiphoid view ultrasound of the heart. What does the ultrasound show? 1. Aortic dissection; 2. Aortic stenosis; 3. Enlarged left ventricle; 4. Enlarged right ventricle; 5. Pericardial effusion

  14. Single cell cytometry of protein function in RNAi treated cells and in native populations

    Directory of Open Access Journals (Sweden)

    Hill Andrew

    2008-08-01

    Full Text Available Abstract Background High Content Screening has been shown to improve results of RNAi and other perturbations, however significant intra-sample heterogeneity is common and can complicate some analyses. Single cell cytometry can extract important information from subpopulations within these samples. Such approaches are important for immune cells analyzed by flow cytometry, but have not been broadly available for adherent cells that are critical to the study of solid-tumor cancers and other disease models. Results We have directly quantitated the effect of resolving RNAi treatments at the single cell level in experimental systems for both exogenous and endogenous targets. Analyzing the effect of an siRNA that targets GFP at the single cell level permits a stronger measure of the absolute function of the siRNA by gating to eliminate background levels of GFP intensities. Extending these methods to endogenous proteins, we have shown that well-level results of the knockdown of PTEN results in an increase in phospho-S6 levels, but at the single cell level, the correlation reveals the role of other inputs into the pathway. In a third example, reduction of STAT3 levels by siRNA causes an accumulation of cells in the G1 phase of the cell cycle, but does not induce apoptosis or necrosis when compared to control cells that express the same levels of STAT3. In a final example, the effect of reduced p53 levels on increased adriamycin sensitivity for colon carcinoma cells was demonstrated at the whole-well level using siRNA knockdown and in control and untreated cells at the single cell level. Conclusion We find that single cell analysis methods are generally applicable to a wide range of experiments in adherent cells using technology that is becoming increasingly available to most laboratories. It is well-suited to emerging models of signaling dysfunction, such as oncogene addition and oncogenic shock. Single cell cytometry can demonstrate effects on cell

  15. Basic fibroblast growth factor is critical to reprogramming buffalo (Bubalus bubalis) primordial germ cells into embryonic germ stem cell-like cells.

    Science.gov (United States)

    Wang, Caizhu; Deng, Yanfei; Chen, Feng; Zhu, Peng; Wei, Jingwei; Luo, Chan; Lu, Fenghua; Yang, Sufang; Shi, Deshun

    2017-03-15

    Primordial germ cells (PGCs) are destined to form gametes in vivo, and they can be reprogrammed into pluripotent embryonic germ (EG) cells in vitro. Buffalo PGC have been reported to be reprogrammed into EG-like cells, but the identities of the major signaling pathways and culture media involved in this derivation remain unclear. Here, the effects of basic fibroblast growth factor (bFGF) and downstream signaling pathways on the reprogramming of buffalo PGCs into EG-like cells were investigated. Results showed bFGF to be critical to buffalo PGCs to dedifferentiate into EG-like cells (20 ng/mL is optimal) with many characteristics of pluripotent stem cells, including alkaline phosphatase (AP) activity, expression of pluripotency marker genes such as OCT4, NANOG, SOX2, SSEA-1, CDH1, and TRA-1-81, and the capacity to differentiate into all three embryonic germ layers. After chemically inhibiting pathways or components downstream of bFGF, data showed that inhibition of the PI3K/AKT pathway led to significantly lower EG cell derivation, while inhibition of P53 activity resulted in an efficiency of EG cell derivation comparable to that in the presence of bFGF. These results suggest that the role of bFGF in PGC-derived EG-like cell generation is mainly due to the activation of the PI3K/AKT/P53 pathway, in particular, the inhibition of P53 function. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Coxsackie and adenovirus receptor is a critical regulator for the survival and growth of oral squamous carcinoma cells.

    Science.gov (United States)

    Saito, K; Sakaguchi, M; Iioka, H; Matsui, M; Nakanishi, H; Huh, N H; Kondo, E

    2014-03-06

    Coxsackie and adenovirus receptor (CAR) is essential for adenovirus infection to target cells, and its constitutive expression in various cancerous and normal tissues has been reported. Recently, the biological role of CAR in human cancers of several different origins has been investigated with respect to tumor progression, metastasis and tumorigenesis. However, its biological function in tumor cells remains controversial. Here we report the critical role of CAR in growth regulation of oral squamous cell carcinomas (SCCs) in vitro and in vivo via the specific interaction with Rho-associated protein kinase (ROCK). Loss of endogenous CAR expression by knockdown using specific small interfering RNA (siRNA) against CAR facilitates growth suppression of SCC cells due to cell dissociation, followed by apoptosis. The consequent morphological reaction was reminiscent of anoikis, rather than epithelial-mesenchymal transition, and the dissociation of oral SCC cells was triggered not by lack of contact with extracellular matrix, but by loss of cell-to-cell contact caused by abnormal translocation of E-cadherin from surface membrane to cytoplasm. Immunoprecipitation assays of the CAR-transfected oral SCC cell line, HSC-2, with or without ROCK inhibitor (Y-27632) revealed that CAR directly associates with ROCKI and ROCKII, which results in inhibition of ROCK activity and contributes to maintenance of cell-to-cell adhesion for their growth and survival. Based on these findings, in vivo behavior of CAR-downregulated HSC-2 cells from siRNA knockdown was compared with that of normally CAR-expressing cells in intraperitoneally xenografted mouse models. The mice engrafted with CAR siRNA-pretreated HSC-2 cells showed poor formation of metastatic foci in contrast to those implanted with the control siRNA-pretreated cells. Thus, CAR substantially has an impact on growth and survival of oral SCC cells as a negative regulator of ROCK in vitro and in vivo.

  17. [Experts consensus on the management of the right heart function in critically ill patients].

    Science.gov (United States)

    Wang, X T; Liu, D W; Zhang, H M; Long, Y; Guan, X D; Qiu, H B; Yu, K J; Yan, J; Zhao, H; Tang, Y Q; Ding, X; Ma, X C; Du, W; Kang, Y; Tang, B; Ai, Y H; He, H W; Chen, D C; Chen, H; Chai, W Z; Zhou, X; Cui, N; Wang, H; Rui, X; Hu, Z J; Li, J G; Xu, Y; Yang, Y; Ouyan, B; Lin, H Y; Li, Y M; Wan, X Y; Yang, R L; Qin, Y Z; Chao, Y G; Xie, Z Y; Sun, R H; He, Z Y; Wang, D F; Huang, Q Q; Jiang, D P; Cao, X Y; Yu, R G; Wang, X; Chen, X K; Wu, J F; Zhang, L N; Yin, M G; Liu, L X; Li, S W; Chen, Z J; Luo, Z

    2017-12-01

    To establish the experts consensus on the right heart function management in critically ill patients. The panel of consensus was composed of 30 experts in critical care medicine who are all members of Critical Hemodynamic Therapy Collaboration Group (CHTC Group). Each statement was assessed based on the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) principle. Then the Delphi method was adopted by 52 experts to reassess all the statements. (1) Right heart function is prone to be affected in critically illness, which will result in a auto-exaggerated vicious cycle. (2) Right heart function management is a key step of the hemodynamic therapy in critically ill patients. (3) Fluid resuscitation means the process of fluid therapy through rapid adjustment of intravascular volume aiming to improve tissue perfusion. Reversed fluid resuscitation means reducing volume. (4) The right ventricle afterload should be taken into consideration when using stroke volume variation (SVV) or pulse pressure variation (PPV) to assess fluid responsiveness.(5)Volume overload alone could lead to septal displacement and damage the diastolic function of the left ventricle. (6) The Starling curve of the right ventricle is not the same as the one applied to the left ventricle,the judgement of the different states for the right ventricle is the key of volume management. (7) The alteration of right heart function has its own characteristics, volume assessment and adjustment is an important part of the treatment of right ventricular dysfunction (8) Right ventricular enlargement is the prerequisite for increased cardiac output during reversed fluid resuscitation; Nonetheless, right heart enlargement does not mandate reversed fluid resuscitation.(9)Increased pulmonary vascular resistance induced by a variety of factors could affect right heart function by obstructing the blood flow. (10) When pulmonary hypertension was detected in clinical scenario, the differentiation of

  18. Systematic Identification of Machine-Learning Models Aimed to Classify Critical Residues for Protein Function from Protein Structure.

    Science.gov (United States)

    Corral-Corral, Ricardo; Beltrán, Jesús A; Brizuela, Carlos A; Del Rio, Gabriel

    2017-10-09

    Protein structure and protein function should be related, yet the nature of this relationship remains unsolved. Mapping the critical residues for protein function with protein structure features represents an opportunity to explore this relationship, yet two important limitations have precluded a proper analysis of the structure-function relationship of proteins: (i) the lack of a formal definition of what critical residues are and (ii) the lack of a systematic evaluation of methods and protein structure features. To address this problem, here we introduce an index to quantify the protein-function criticality of a residue based on experimental data and a strategy aimed to optimize both, descriptors of protein structure (physicochemical and centrality descriptors) and machine learning algorithms, to minimize the error in the classification of critical residues. We observed that both physicochemical and centrality descriptors of residues effectively relate protein structure and protein function, and that physicochemical descriptors better describe critical residues. We also show that critical residues are better classified when residue criticality is considered as a binary attribute (i.e., residues are considered critical or not critical). Using this binary annotation for critical residues 8 models rendered accurate and non-overlapping classification of critical residues, confirming the multi-factorial character of the structure-function relationship of proteins.

  19. Impaired Leydig cell function in infertile men

    DEFF Research Database (Denmark)

    Andersson, A-M; Jørgensen, N; Frydelund-Larsen, L

    2004-01-01

    To investigate whether an impaired Leydig cell function is present in severely oligospermic men, serum testosterone (T), LH, estradiol (E(2)), and SHBG levels in 357 idiopathic infertile men were compared with levels in 318 proven fertile men. In addition, the T/LH ratio, E(2)/T ratio, and calcul......To investigate whether an impaired Leydig cell function is present in severely oligospermic men, serum testosterone (T), LH, estradiol (E(2)), and SHBG levels in 357 idiopathic infertile men were compared with levels in 318 proven fertile men. In addition, the T/LH ratio, E(2)/T ratio......, and calculated free T index (cFT) were compared between the two groups.A shift toward lower serum T levels, cFT, and T/LH ratio and higher serum LH, E(2), and E(2)/T levels was observed in the group of infertile men. On average, the infertile men had 18, 26, and 34% lower serum T, cFT, and T/LH levels......, respectively, and 19, 18, and 33% higher serum LH, E(2), and E(2)/T levels, respectively, than the fertile men. Twelve percent of the infertile men had a serum T level that fell below the 2.5 percentile of the fertile levels, and 15% of the infertile men had a LH level that was above the 97.5 percentile...

  20. TMC function in hair cell transduction

    Science.gov (United States)

    Holt, Jeffrey R.; Pan, Bifeng; Koussa, Mounir A.; Asai, Yukako

    2014-01-01

    Transmembrane channel-like (TMC) proteins 1 and 2 are necessary for hair cell mechanotransduction but their precise function is controversial. A growing body of evidence supports a direct role for TMC1 and TMC2 as components of the transduction complex. However, a number of important questions remain and alternate hypotheses have been proposed. Here we present an historical overview of the identification and cloning of Tmc genes, a discussion of mutations in TMC1 that cause deafness in mice and humans and a brief review of other members of the Tmc gene superfamily. We also examine expression of Tmc mRNAs and localization of the protein products. The review focuses on potential functions of TMC proteins and the evidence from Beethoven mice that suggests a direct role for TMC1 in hair cell mechanotransduction. Data that support alternate interpretations are also considered. The article concludes with a discussion of outstanding questions and future directions for TMC research. This article is part of a Special Issue entitled “Annual Reviews 2014”. PMID:24423408

  1. Histamine regulates murine primary dendritic cell functions.

    Science.gov (United States)

    Schenk, Heiko; Neumann, Detlef; Kloth, Christina

    2016-10-01

    The modulation of antigen uptake and activation of dendritic cells (DCs) by histamine may function as a regulator of inflammation. Therefore, we sought to determine the impact of histamine on antigen uptake by and activation of murine DCs. DCs from spleen and lung were either identified by flow cytometry or were immunomagnetically enriched. Cells were stimulated with histamine, and the regulation of MHC-II and co-stimulatory molecule expression (CD80, CD86, and ICOS-L) and antigen uptake were quantified by flow cytometry. Individual contributions of the histamine receptor subtypes were determined by using the antagonists mepyramine (histamine H1-receptor: H1R), famotidine (H2R), and JNJ 7777120 (H4R). Histamine accelerated the uptake of soluble antigen via the H1R, H2R, and H4R in splenic DCs. Co-stimulatory molecule expression was enhanced already by enrichment procedures, thus, the analyses were performed in unseparated cell populations. Histamine enhanced the expression of CD86 and ICOS-L while expression of CD80 was unaffected. Antagonism at H1R, H2R, and H4R and at H1R and H4R reduced the histamine-induced enhanced expression of CD86 and ICOS-L, respectively. Histamine contributes to the regulation of the immunological synapse by stimulation of antigen uptake and activation of DCs via H1R, H2R, and H4R.

  2. Origins of Protein Functions in Cells

    Science.gov (United States)

    Seelig, Burchard; Pohorille, Andrzej

    2011-01-01

    In modern organisms proteins perform a majority of cellular functions, such as chemical catalysis, energy transduction and transport of material across cell walls. Although great strides have been made towards understanding protein evolution, a meaningful extrapolation from contemporary proteins to their earliest ancestors is virtually impossible. In an alternative approach, the origin of water-soluble proteins was probed through the synthesis and in vitro evolution of very large libraries of random amino acid sequences. In combination with computer modeling and simulations, these experiments allow us to address a number of fundamental questions about the origins of proteins. Can functionality emerge from random sequences of proteins? How did the initial repertoire of functional proteins diversify to facilitate new functions? Did this diversification proceed primarily through drawing novel functionalities from random sequences or through evolution of already existing proto-enzymes? Did protein evolution start from a pool of proteins defined by a frozen accident and other collections of proteins could start a different evolutionary pathway? Although we do not have definitive answers to these questions yet, important clues have been uncovered. In one example (Keefe and Szostak, 2001), novel ATP binding proteins were identified that appear to be unrelated in both sequence and structure to any known ATP binding proteins. One of these proteins was subsequently redesigned computationally to bind GTP through introducing several mutations that introduce targeted structural changes to the protein, improve its binding to guanine and prevent water from accessing the active center. This study facilitates further investigations of individual evolutionary steps that lead to a change of function in primordial proteins. In a second study (Seelig and Szostak, 2007), novel enzymes were generated that can join two pieces of RNA in a reaction for which no natural enzymes are known

  3. Controlling the Morphology and Efficiency of Hybrid ZnO : Polythiophene Solar Cells Via Side Chain Functionalization

    NARCIS (Netherlands)

    Oosterhout, Stefan D.; Koster, L. Jan Anton; van Bavel, Svetlana S.; Loos, Joachim; Stenzel, Ole; Thiedmann, Ralf; Schmidt, Volker; Campo, Bert; Cleij, Thomas J.; Lutzen, Laurence; Vanderzande, Dirk; Wienk, Martijn M.; Janssen, Rene A. J.

    2011-01-01

    The efficiency of polymer - metal oxide hybrid solar cells depends critically on the intimacy of mixing of the two semiconductors. The effect of side chain functionalization on the morphology and performance of conjugated polymer:ZnO solar cells is investigated. Using an ester-functionalized side

  4. Models for Microbial Fuel Cells: A critical review

    Science.gov (United States)

    Xia, Chengshuo; Zhang, Daxing; Pedrycz, Witold; Zhu, Yingmin; Guo, Yongxian

    2018-01-01

    Microbial fuel cells (MFCs) have been widely viewed as one of the most promising alternative sources of renewable energy. A recognition of needs of efficient development methods based on multidisciplinary research becomes crucial for the optimization of MFCs. Modeling of MFCs is an effective way for not only gaining a thorough understanding of the effects of operation conditions on the performance of power generation but also becomes of essential interest to the successful implementation of MFCs. The MFC models encompass the underlying reaction process and limiting factors of the MFC. The models come in various forms, such as the mathematical equations or the equivalent circuits. Different modeling focuses and approaches of the MFC have emerged. In this study, we present a state of the art of MFCs modeling; the past modeling methods are reviewed as well. Models and modeling methods are elaborated on based on the classification provided by Mechanism-based models and Application-based models. Mechanisms, advantages, drawbacks, and application fields of different models are illustrated as well. We exhibit a complete and comprehensive exposition of the different models for MFCs and offer further guidance to promote the performance of MFCs.

  5. ‘Promising Spaces’: Universities’ Critical-Moral Mission and Educative Function

    Directory of Open Access Journals (Sweden)

    Monica McLean

    2015-12-01

    Full Text Available Attention has been drawn to a hollowing out of universities' purposes to serve economic interests only. This dissatisfaction has provoked thinking about how to reclaim a critical moral role for universties in society. Inspired by contemporary utopian studies the paper brings together traditional ideas about how transmitting university knowledge connects to universities' critical-moral functions; Amartya Sen and Martha Nussbaum's capabilities approach adapted for education; and Bernstein's theories about knowledge distribution. Focusing on the educative function, the aim is to develop a theoretically informed and practical vision of a university education, which is both personally transformative and produces critical citizens and workers. Research evidence from two projects on university education reveals 'promising spaces' (Cooper, 2014. I conclude that there is reason to believe that the transmission and acquisition of knowledge and understanding in specific fields is key to preserving and recreating a critical-moral mission for universities wherever they are in the world, even though current conditions are inclement and unequal.

  6. Does mindfulness enhance critical thinking? Evidence for the mediating effects of executive functioning in the relationship between mindfulness and critical thinking

    Directory of Open Access Journals (Sweden)

    Chris eNoone

    2016-01-01

    Full Text Available Mindfulness originated in the Buddhist tradition as a way of cultivating clarity of thought. Despite the fact that this behaviour is best captured using critical thinking assessments, no studies have examined the effects of mindfulness on critical thinking or the mechanisms underlying any such possible relationship. Even so, mindfulness has been suggested as being beneficial for critical thinking in higher education. Critical thinking is recognised as an important higher-order cognitive process which involves the ability to analyse and evaluate evidence and arguments. Such non-automatic, reflective responses generally require the engagement of executive functioning which includes updating, inhibition and shifting of representations in working memory. Based on research showing that mindfulness enhances aspects of executive functioning and certain higher-order cognitive processes, we hypothesised that individuals higher in facets of dispositional mindfulness would demonstrate greater critical thinking performance, and that this relationship would be mediated by executive functioning. Cross-sectional assessment of these constructs in a sample of 178 university students was achieved using the observing and non-reactivity sub-scales of the Five Factor Mindfulness Questionnaire, a battery of executive functioning tasks and the Halpern Critical Thinking Assessment. Our hypotheses were tested by constructing a multiple meditation model which was analysed using Structural Equation Modelling. Evidence was found for inhibition mediating the relationships between both observing and non-reactivity and critical thinking in different ways. Indirect-only (or full mediation was demonstrated for the relationship between observing, inhibition and critical thinking. Competitive mediation was demonstrated for the relationship between non-reactivity, inhibition and critical thinking. This suggests additional mediators of the relationship between non-reactivity and

  7. Assessment of cardiac function and circulatory status in critically ill patients

    Directory of Open Access Journals (Sweden)

    Gorazd Voga

    2007-12-01

    Full Text Available Background: Assessment of cardiac function and circulation is mandatory in almost all critically ill patients. In many patients morphological diagnosis of actual or pre-existing cardiac diseases and their functional consequences should be obtained.Methods: Cardiac function can be assessed by various non-invasive and invasive methods. The value of every method should be assessed according to its ability and reliability to assess preload, cardiac output and the adequacy of flow. In hemodinamically unstable patients frequent reassessment must be performed, because of rapid changes of patients’ conditions. Therefore, all methods for hemodynamic assessment in the ICU must be available on the 24 hours basis. Combined non-invasive and invasive approach to the assessment of cardiac function and circulation is preferred. After initial assessment of cardiac function according to clinical examination, electrocardiogram, chest X-ray and blood gas analysis, echocardiography is routinely used. When continuous monitoring of cardiac function is mandatory, complete invasive monitoring with pulmonary artery catheter and arterial line is employed. Monitoring of pulmonary pressures, continuous cardiac output, mixed venous blood oxygen saturation, and parameters of right ventricular function is the best choice to obtain complete information of hemodynamic situation. In patients with increased pulmonary vascular permeability the monitoring of cardiac output by pulse contour method together with measurement of intrathoracic blood volume and extravascular lung water could be even better choice.Conclusions: Assessment of cardiac function and circulatory status by rational use of various non-invasive and invasive methods is one of the essential components of critical care management.

  8. Tumor microenvironment and metabolic synergy in breast cancers: critical importance of mitochondrial fuels and function.

    Science.gov (United States)

    Martinez-Outschoorn, Ubaldo; Sotgia, Federica; Lisanti, Michael P

    2014-04-01

    Metabolic synergy or metabolic coupling between glycolytic stromal cells (Warburg effect) and oxidative cancer cells occurs in human breast cancers and promotes tumor growth. The Warburg effect or aerobic glycolysis is the catabolism of glucose to lactate to obtain adenosine triphosphate (ATP). This review summarizes the main findings on this stromal metabolic phenotype, and the associated signaling pathways, as well as the critical role of oxidative stress and autophagy, all of which promote carcinoma cell mitochondrial metabolism and tumor growth. Loss of Caveolin 1 (Cav-1) and the upregulation of monocarboxylate transporter 4 (MCT4) in stromal cells are novel markers of the Warburg effect and metabolic synergy between stromal and carcinoma cells. MCT4 and Cav-1 are also breast cancer prognostic biomarkers. Reactive oxygen species (ROS) are key mediators of the stromal Warburg effect. High ROS also favors cancer cell mitochondrial metabolism and tumorigenesis, and anti-oxidants can reverse this altered stromal and carcinoma metabolism. A pseudo-hypoxic state with glycolysis and low mitochondrial metabolism in the absence of hypoxia is a common feature in breast cancer. High ROS induces loss of Cav-1 in stromal cells and is sufficient to generate a pseudo-hypoxic state. Loss of Cav-1 in the stroma drives glycolysis and lactate extrusion via HIF-1α stabilization and the upregulation of MCT4. Stromal cells with loss of Cav-1 and/or high expression of MCT4 also show a catabolic phenotype, with enhanced macroautophagy. This catabolic state in stromal cells is driven by hypoxia-inducible factor (HIF)-1α, nuclear factor κB (NFκB), and JNK activation and high ROS generation. A feed-forward loop in stromal cells regulates pseudo-hypoxia and metabolic synergy, with Cav-1, MCT4, HIF-1α, NFκB, and ROS as its key elements. Metabolic synergy also may occur between cancer cells and cells in distant organs from the tumor. Cancer cachexia, which is due to severe organismal

  9. Parametric Optimization of Some Critical Operating System Functions--An Alternative Approach to the Study of Operating Systems Design

    Science.gov (United States)

    Sobh, Tarek M.; Tibrewal, Abhilasha

    2006-01-01

    Operating systems theory primarily concentrates on the optimal use of computing resources. This paper presents an alternative approach to teaching and studying operating systems design and concepts by way of parametrically optimizing critical operating system functions. Detailed examples of two critical operating systems functions using the…

  10. Uncovering Factors Related to Pancreatic Beta-Cell Function

    OpenAIRE

    Curran, Aoife M.; Ryan, Miriam F.; Drummond, Elaine; Gibney, Eileen R.; Gibney, Michael J.; Roche, Helen M.; Brennan, Lorraine

    2016-01-01

    Aim: The incidence of type 2 diabetes has increased rapidly on a global scale. Beta-cell dysfunction contributes to the overall pathogenesis of type 2 diabetes. However, factors contributing to beta-cell function are not clear. The aims of this study were (i) to identify factors related to pancreatic beta-cell function and (ii) to perform mechanistic studies in vitro. Methods: Three specific measures of beta-cell function were assessed for 110 participants who completed an oral glucose tolera...

  11. Expression and function of nicotinic acetylcholine receptors in stem cells

    Directory of Open Access Journals (Sweden)

    Herman S. Cheung

    2016-07-01

    Full Text Available Nicotinic acetylcholine receptors are prototypical ligand gated ion channels typically found in muscular and neuronal tissues. Functional nicotinic acetylcholine receptors, however, have also recently been identified on other cell types, including stem cells. Activation of these receptors by the binding of agonists like choline, acetylcholine, or nicotine has been implicated in many cellular changes. In regards to stem cell function, nicotinic acetylcholine receptor activation leads to changes in stem cell proliferation, migration and differentiation potential. In this review we summarize the expression and function of known nicotinic acetylcholine receptors in different classes of stem cells including: pluripotent stem cells, mesenchymal stem cells, periodontal ligament derived stem cells, and neural progenitor cells and discuss the potential downstream effects of receptor activation on stem cell function.

  12. Intravital imaging of CD8+ T cell function in cancer.

    Science.gov (United States)

    Mempel, Thorsten R; Bauer, Christian A

    2009-01-01

    Recent technological advances in photonics are making intravital microscopy (IVM) an increasingly powerful approach for the mechanistic exploration of biological processes in the physiological context of complex native tissue environments. Direct, dynamic and multiparametric visualization of immune cell behavior in living animals at cellular and subcellular resolution has already proved its utility in auditing basic immunological concepts established through conventional approaches and has also generated new hypotheses that can conversely be complemented and refined by traditional experimental methods. The insight that outgrowing tumors must not necessarily have evaded recognition by the adaptive immune system, but can escape rejection by actively inducing a state of immunological tolerance calls for a detailed investigation of the cellular and molecular mechanisms by which the anti-cancer response is subverted. Along with molecular imaging techniques that provide dynamic information at the population level, IVM can be expected to make a critical contribution to this effort by allowing the observation of immune cell behavior in vivo at single cell-resolution. We review here how IVM-based investigation can help to clarify the role of cytotoxic T lymphocytes (CTL) in the immune response against cancer and identify the ways by which their function might be impaired through tolerogenic mechanisms.

  13. Report on the 2011 Critical Assessment of Function Annotation (CAFA) meeting

    Energy Technology Data Exchange (ETDEWEB)

    Friedberg, Iddo [Miami Univ., Oxford, OH (United States)

    2015-01-21

    The Critical Assessment of Function Annotation meeting was held July 14-15, 2011 at the Austria Conference Center in Vienna, Austria. There were 73 registered delegates at the meeting. We thank the DOE for this award. It helped us organize and support a scientific meeting AFP 2011 as a special interest group (SIG) meeting associated with the ISMB 2011 conference. The conference was held in Vienna, Austria, in July 2011. The AFP SIG was held on July 15-16, 2011 (immediately preceding the conference). The meeting consisted of two components, the first being a series of talks (invited and contributed) and discussion sections dedicated to protein function research, with an emphasis on the theory and practice of computational methods utilized in functional annotation. The second component provided a large-scale assessment of computational methods through participation in the Critical Assessment of Functional Annotation (CAFA). The meeting was exciting and, based on feedback, quite successful. There were 73 registered participants. The schedule was only slightly different from the one proposed, due to two cancellations. Dr. Olga Troyanskaya has canceled and we invited Dr. David Jones instead. Similarly, instead of Dr. Richard Roberts, Dr. Simon Kasif gave a closing keynote. The remaining invited speakers were Janet Thornton (EBI) and Amos Bairoch (University of Geneva).

  14. Optical functions and critical points of dilute bismide alloys studied by spectroscopic ellipsometry

    Science.gov (United States)

    Bushell, Z. L.; Joseph, R. M.; Nattermann, L.; Ludewig, P.; Volz, K.; Keddie, J. L.; Sweeney, S. J.

    2018-01-01

    Critical point transition energies and optical functions of the novel GaAs-based dilute bismide alloys GaAsBi, GaNAsBi, and GaPAsBi were determined using spectroscopic ellipsometry. The ellipsometry data were analyzed using a parameterized semiconductor model to represent the dielectric function of the alloys as the sum of Gaussian oscillators centered on critical points in the band structure, and from this extracting the energies of those critical points. The band gap and spin-orbit splitting were measured for samples for a range of alloy compositions. The first experimental measurements of the spin-orbit splitting in the GaNAsBi quaternary alloy were obtained, which showed that it is approximately independent of N content, in agreement with theory. The real component of the refractive index in the transparent region below the band gap was found to decrease as the band gap increased for all of the alloys studied, following the usual relations for conventional semiconductors. This work provides key electronic and optical parameters for the development of photonic devices based on these novel alloys.

  15. Autologous bone marrow mononuclear cells transplant in patients with critical leg ischemia: preliminary clinical results.

    Science.gov (United States)

    Li, Min; Zhou, Hua; Jin, Xing; Wang, Mo; Zhang, Shiyi; Xu, Lei

    2013-10-01

    Stem cell transplant can induce vasculogenesis and improve the blood supply to an ischemic region, offering hope for chronic lower extremity ischemic diseases. Bone marrow mononuclear cells are one of the sources for stem cell transplants. We sought to observe the safety and efficacy of autologous bone marrow mononuclear cells transplant for treating critical limb ischemia. Eligible patients were randomized 1:1 to receive placebo (0.9% NaCl) or 1 × 107 piece/mL bone marrow mononuclear cell transplant. For 6 months, patients' skin ulcers, ankle-brachial index, and rest pain were examined and recorded before and after treatment. Six months after the bone marrow mononuclear cells transplant, clinical symptoms like rest pain and skin ulcers gradually abated (P transplant (P Autologous bone marrow mononuclear cells transplant for treatment of patients with chronic limb ischemia is safe, effective, and feasible.

  16. Extracellular matrix dynamics and functions in the social amoeba Dictyostelium: A critical review.

    Science.gov (United States)

    Huber, Robert J; O'Day, Danton H

    2017-01-01

    The extracellular matrix (ECM) is a dynamic complex of glycoproteins, proteoglycans, carbohydrates, and collagen that serves as an interface between mammalian cells and their extracellular environment. Essential for normal cellular homeostasis, physiology, and events that occur during development, it is also a key functionary in a number of human diseases including cancer. The social amoeba Dictyostelium discoideum secretes an ECM during multicellular development that regulates multicellularity, cell motility, cell differentiation, and morphogenesis, and provides structural support and protective layers to the resulting differentiated cell types. Proteolytic processing within the Dictyostelium ECM leads to specific bioactive factors that regulate cell motility and differentiation. Here we review the structure and functions of the Dictyostelium ECM and its role in regulating multicellular development. The questions and challenges that remain and how they can be answered are also discussed. The Dictyostelium ECM shares many of the features of mammalian and plant ECM, and thus presents an excellent system for studying the structure and function of the ECM. As a genetically tractable model organism, Dictyostelium offers the potential to further elucidate ECM functions, and to possibly reveal previously unknown roles for the ECM. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Critical Flicker Fusion Predicts Executive Function in Younger and Older Adults.

    Science.gov (United States)

    Mewborn, Catherine; Renzi, Lisa M; Hammond, Billy R; Miller, L Stephen

    2015-11-01

    Critical flicker fusion (CFF), a measure of visual processing speed, has often been regarded as a basic metric underlying a number of higher cognitive functions. To test this, we measured CFF, global cognition, and several cognitive subdomains. Because age is a strong covariate for most of these variables, both younger (n = 72) and older (n = 57) subjects were measured. Consistent with expectations, age was inversely related to CFF and performance on all of the cognitive measures except for visual memory. In contrast, age-adjusted CFF thresholds were only positively related to executive function. Results showed that CFF predicted executive function across both age groups and accounted for unique variance in performance above and beyond age and global cognitive status. The current findings suggest that CFF may be a unique predictor of executive dysfunction. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Stability and function of regulatory T cells expressing the transcription factor T-bet.

    Science.gov (United States)

    Levine, Andrew G; Mendoza, Alejandra; Hemmers, Saskia; Moltedo, Bruno; Niec, Rachel E; Schizas, Michail; Hoyos, Beatrice E; Putintseva, Ekaterina V; Chaudhry, Ashutosh; Dikiy, Stanislav; Fujisawa, Sho; Chudakov, Dmitriy M; Treuting, Piper M; Rudensky, Alexander Y

    2017-06-15

    Adaptive immune responses are tailored to different types of pathogens through differentiation of naive CD4 T cells into functionally distinct subsets of effector T cells (T helper 1 (T H 1), T H 2, and T H 17) defined by expression of the key transcription factors T-bet, GATA3, and RORγt, respectively. Regulatory T (T reg ) cells comprise a distinct anti-inflammatory lineage specified by the X-linked transcription factor Foxp3 (refs 2, 3). Paradoxically, some activated T reg cells express the aforementioned effector CD4 T cell transcription factors, which have been suggested to provide T reg cells with enhanced suppressive capacity. Whether expression of these factors in T reg cells-as in effector T cells-is indicative of heterogeneity of functionally discrete and stable differentiation states, or conversely may be readily reversible, is unknown. Here we demonstrate that expression of the T H 1-associated transcription factor T-bet in mouse T reg cells, induced at steady state and following infection, gradually becomes highly stable even under non-permissive conditions. Loss of function or elimination of T-bet-expressing T reg cells-but not of T-bet expression in T reg cells-resulted in severe T H 1 autoimmunity. Conversely, following depletion of T-bet - T reg cells, the remaining T-bet + cells specifically inhibited T H 1 and CD8 T cell activation consistent with their co-localization with T-bet + effector T cells. These results suggest that T-bet + T reg cells have an essential immunosuppressive function and indicate that T reg cell functional heterogeneity is a critical feature of immunological tolerance.

  19. Evolution and development of hair cell polarity and efferent function in the inner ear.

    Science.gov (United States)

    Sienknecht, Ulrike J; Köppl, Christine; Fritzsch, Bernd

    2014-01-01

    The function of the inner ear critically depends on mechanoelectrically transducing hair cells and their afferent and efferent innervation. The first part of this review presents data on the evolution and development of polarized vertebrate hair cells that generate a sensitive axis for mechanical stimulation, an essential part of the function of hair cells. Beyond the cellular level, a coordinated alignment of polarized hair cells across a sensory epithelium, a phenomenon called planar cell polarity (PCP), is essential for the organ's function. The coordinated alignment of hair cells leads to hair cell orientation patterns that are characteristic of the different sensory epithelia of the vertebrate inner ear. Here, we review the developmental mechanisms that potentially generate molecular and morphological asymmetries necessary for the control of PCP. In the second part, this review concentrates on the evolution, development and function of the enigmatic efferent neurons terminating on hair cells. We present evidence suggestive of efferents being derived from motoneurons and synapsing predominantly onto a unique but ancient cholinergic receptor. A review of functional data shows that the plesiomorphic role of the efferent system likely was to globally shut down and protect the peripheral sensors, be they vestibular, lateral line or auditory hair cells, from desensitization and damage during situations of self-induced sensory overload. The addition of a dedicated auditory papilla in land vertebrates appears to have favored the separation of vestibular and auditory efferents and specializations for more sophisticated and more diverse functions. © 2014 S. Karger AG, Basel.

  20. Enhancement of biomembrane functions under phase-separated conditions: A self-organized criticality phenomenon?

    International Nuclear Information System (INIS)

    Eze, M.O.; Chela Flores, J.

    1993-12-01

    Self-organized criticality (SOC) is hereby proposed as a possible physical basis for explaining observations in the temperature-dependence of the rates of biological membrane-associated events. The biomembrane undergoes a reversible, cooperative, thermotropic gel-to-liquid crystalline phase transition which is broad, and involves lateral phase separation. The lateral phase separated (rather than the totally gel-, or the totally liquid crystalline-) membrane state has been observed to be the state in which vital membrane functions are facilitated. The membrane in this unique state is viewed, for our purposes here, as a dynamical, extended dissipative system with spatial and temporal degrees of freedom, exhibiting power law behaviour, typical of the self-organized critical state. Experiments are suggested for verifying this hypothesis. (author). 30 refs

  1. Alterations in cell function with ischemia and shock and their correction.

    Science.gov (United States)

    Chaudry, I H; Clemens, M G; Baue, A E

    1981-10-01

    Progressive cell injury occurs with shock and ischemia, beginning with functional changes in the cell and cell membrane. Membrane transport and potential decrease, Na+ enters and K+ leaves cells; N+-K+ adenosine triphosphatase is activated, adenosine triphosphate (ATP) is used, and mitochondria are stimulated as increased lactate produces acidosis. Energy and cyclic adenosine monophosphate levels decrease, Ca2+ regulation is compromised, and nuclear function and protein synthesis are depressed. The cell swells, and further membrane changes occur with altered hormonal effects and mitochondrial uncoupling. Finally, lysosomes leak, intracellular and mitochondria disruption occurs, and the cell is destroyed. Based on these changes, attempts were made to directly support cell function during low-flow states. After volume replacement and vasoactive agents, other modalities, eg, substrates, membrane-stabilizing solutions, osmotic agents, and energy compounds were used. The use of ATP-MgCl2 was helpful in many experimental low-flow states, with an improvement in cell function mediated by micro-circulatory, cell membrane, or energy-recycling effects. Clinical examples of altered cell and organ function with ischemia and shock are numerous and play a critical role in the development of multiple systems failure. The potential for biochemical support and correction of these problems is now recognized. Benefits have already been achieved in myocardial preservation during cardiac operations, kidney preservation for transplantation, and circulatory and metabolic support of the injured and septic patient.

  2. Environmental drivers of soil microbial community structure and function at the Avon River Critical Zone Observatory.

    Science.gov (United States)

    Gleeson, Deirdre; Mathes, Falko; Farrell, Mark; Leopold, Matthias

    2016-11-15

    The Critical Zone is defined as the thin, permeable layer from the tops of the trees to the bottom of the bedrock that sustains terrestrial life on Earth. The geometry and shape of the various weathering zones are known as the critical zone architecture. At the centre of the Critical Zone are soils and the microorganisms that inhabit them. In Western Australia, the million-year-old stable weathering history and more recent lateral erosion during the past hundreds of thousands of years have created a geomorphic setting where deep weathering zones are now exposed on the surface along the flanks of many lateritic hills. These old weathering zones provide diverse physical and chemical properties that influence near surface pedologic conditions and thus likely shape current surface microbiology. Here, we present data derived from a small lateritic hill on the UWA Farm Ridgefield. Spatial soil sampling revealed the contrasting distribution patterns of simple soil parameters such as pH (CaCl2) and electric conductivity. These are clearly linked with underlying changes of the critical zone architecture and show a strong contrast with low values of pH3.3 at the top of the hill to pH5.3 at the bottom. These parameters were identified as major drivers of microbial spatial variability in terms of bacterial and archaeal community composition but not abundance. In addition, we used sensitive (14)C labelling to assess turnover of three model organic nitrogen compounds - an important biogeochemical functional trait relating to nutrient availability. Though generally rapid and in the order of rates reported elsewhere (t½10h). In conclusion, we have shown that the weathering and erosion history of ancient Western Australia affects the surface pedology and has consequences for microbial community structure and function. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. B cells promote inflammation in obesity and type 2 diabetes through regulation of T-cell function and an inflammatory cytokine profile.

    Science.gov (United States)

    DeFuria, Jason; Belkina, Anna C; Jagannathan-Bogdan, Madhumita; Snyder-Cappione, Jennifer; Carr, Jordan David; Nersesova, Yanina R; Markham, Douglas; Strissel, Katherine J; Watkins, Amanda A; Zhu, Min; Allen, Jessica; Bouchard, Jacqueline; Toraldo, Gianluca; Jasuja, Ravi; Obin, Martin S; McDonnell, Marie E; Apovian, Caroline; Denis, Gerald V; Nikolajczyk, Barbara S

    2013-03-26

    Patients with type 2 diabetes (T2D) have disease-associated changes in B-cell function, but the role these changes play in disease pathogenesis is not well established. Data herein show B cells from obese mice produce a proinflammatory cytokine profile compared with B cells from lean mice. Complementary in vivo studies show that obese B cell-null mice have decreased systemic inflammation, inflammatory B- and T-cell cytokines, adipose tissue inflammation, and insulin resistance (IR) compared with obese WT mice. Reduced inflammation in obese/insulin resistant B cell-null mice associates with an increased percentage of anti-inflammatory regulatory T cells (Tregs). This increase contrasts with the sharply decreased percentage of Tregs in obese compared with lean WT mice and suggests that B cells may be critical regulators of T-cell functions previously shown to play important roles in IR. We demonstrate that B cells from T2D (but not non-T2D) subjects support proinflammatory T-cell function in obesity/T2D through contact-dependent mechanisms. In contrast, human monocytes increase proinflammatory T-cell cytokines in both T2D and non-T2D analyses. These data support the conclusion that B cells are critical regulators of inflammation in T2D due to their direct ability to promote proinflammatory T-cell function and secrete a proinflammatory cytokine profile. Thus, B cells are potential therapeutic targets for T2D.

  4. Intact mammalian cell function on semi-conductor nanowire arrays: new perspectives for cell-based biosensing

    DEFF Research Database (Denmark)

    Berthing, Trine; Bonde, Sara; Sørensen, Claus Birger

    2011-01-01

    Nanowires (NWs) are attracting more and more interest due to their potential cellular applications, such as delivery of compounds or sensing platforms. Arrays of vertical indium-arsenide (InAs) NWs are interfaced with human embryonic kidney cells and rat embryonic dorsal root ganglion neurons....... A selection of critical cell functions and pathways are shown not to be impaired, including cell adhesion, membrane integrity, intracellular enzyme activity, DNA uptake, cytosolic and membrane protein expression, and the neuronal maturation pathway. The results demonstrate the low invasiveness of InAs NW...

  5. Impact of ghrelin on body composition and muscle function in a long-term rodent model of critical illness.

    Science.gov (United States)

    Hill, Neil E; Murphy, Kevin G; Saeed, Saima; Phadke, Rahul; Chambers, Darren; Wilson, Duncan R; Brett, Stephen J; Singer, Mervyn

    2017-01-01

    Patients with multiple injuries or sepsis requiring intensive care treatment invariably develop a catabolic state with resultant loss of lean body mass, for which there are currently no effective treatments. Recovery can take months and mortality is high. We hypothesise that treatment with the orexigenic and anti-inflammatory gastric hormone, ghrelin may attenuate the loss of body mass following critical illness and improve recovery. Male Wistar rats received an intraperitoneal injection of the fungal cell wall derivative zymosan to induce a prolonged peritonitis and consequent critical illness. Commencing at 48h after zymosan, animals were randomised to receive a continuous infusion of ghrelin or vehicle control using a pre-implanted subcutaneous osmotic mini-pump, and continued for 10 days. Zymosan peritonitis induced significant weight loss and reduced food intake with a nadir at Day 2 and gradual recovery thereafter. Supra-physiologic plasma ghrelin levels were achieved in the treated animals. Ghrelin-treated rats ate more food and gained more body mass than controls. Ghrelin increased adiposity and promoted carbohydrate over fat metabolism, but did not alter total body protein, muscle strength nor muscle morphology. Muscle mass and strength remained significantly reduced in all zymosan-treated animals, even at ten days post-insult. Continuous infusion of ghrelin increased body mass and food intake, but did not increase muscle mass nor improve muscle function, in a long-term critical illness recovery model. Further studies with pulsatile ghrelin delivery or additional anabolic stimuli may further clarify the utility of ghrelin in survivors of critical illness.

  6. Critical Quality Source Diagnosis for Dam Concrete Construction Based on Quality Gain-loss Function

    Directory of Open Access Journals (Sweden)

    Bo Wang

    2014-06-01

    Full Text Available In dam concrete construction process, it not only has quality loss arising from quality fluctuation, but also gains quality compensation effect due to the mutual cooperation and adaptation coupling between working procedures (WPs. The calculation and transmission complexity of the quality loss and quality compensation affect the quality management of dam concrete construction. As the quality compensation effect existing in the production practice cannot be described by Taguchi quality loss function, the concept of quality gain-loss function was presented in this paper, which was based on endowing the constant term in the expansion of Taylor series with physical meaning—quality compensation. Based on quality gain-loss function theory, a new quality gain-loss transmission model of dam concrete construction based on GERT network was constructed and its effective algorithm was designed. WP quality gain-loss and its impact on the final product were reasonably measured, and the critical quality routes and critical quality WPs were detected and diagnosed in dam concrete construction network. Summer temperature-controlled concrete construction in the third phase of Three Gorges Project (TGP was taken as an example to carry out the study, and the calculation results showed the validity and practicability of the presented model and algorithm.

  7. On the applicability of the critical safety function concept to a uranium hexafluoride conversion unit

    International Nuclear Information System (INIS)

    Santos, F.C.; Goncalves, J.S.; Melo, P.F. Frutuoso e; Medeiros, J.A.C.C.

    2013-01-01

    This paper presents a discussion on the applicability on the critical safety function (CSF) concept as a design criterion for the new UF 6 conversion plant of Industrias Nucleares do Brazil (INB). This discussion is in the context of accident management, under the safety function oriented management. Safety functions may be understood as those whose loss may lead to releases of radioactive material or highly toxic chemicals, having possible radiological and/or occupational consequences for workers, the public or the environment. They should be designed to prevent criticality and to ensure adequate process confinement, thus preventing radioactive material releases that might lead to internal or external exposure and highly toxic chemical releases and exposure. The main hazards is the potential release of chemicals, especially HF and UF 6 . A criticality hazard exists only if the conversion facility processes uranium with a 235 U concentration greater than 1% Industrial activities for UF 6 production include handling and processing explosive, toxic and lethal chemicals, such as HF, H 2 and elemental F 2 , besides intermediate compounds containing uranium. State trees and definition of logical arrangements to construct an annunciation system are the next development stages, resulting form the establishment of applicable CSFs as representative of the next development stages, resulting from the establishment of applicable CSFs as representative of the various systems that make up the conversion plant. Discussed also in the biggest challenge of the development of this innovation, that is, the uncertainties related to the impact of human factors (not subject to monitoring by sensors or process conventional instrumentation). (author)

  8. Flow rate dependency of critical wall shear stress in a radial-flow cell

    DEFF Research Database (Denmark)

    Detry, J.G.; Jensen, Bo Boye Busk; Sindic, M.

    2009-01-01

    In the present work, a radial-flow cell was used to study the removal of starch particle aggregates from several solid substrates (glass, stainless steel, polystyrene and PTFE) in order to determine the critical wall shear stress value for each case. The particle aggregates were formed by aspersion...

  9. Untimely oxidative stress in β-cells leads to diabetes - Role of circadian clock in β-cell function.

    Science.gov (United States)

    Lee, J; Ma, K; Moulik, M; Yechoor, V

    2018-02-16

    Diabetes results from a loss of β-cell function. With the number of people with diabetes reaching epidemic proportions globally, understanding mechanisms that are contributing to this increasing prevalence is critical. One such factor has been circadian disruption, with shift-work, light pollution, jet-lag, increased screen time, all acting as potential contributory factors. Though circadian disruption has been epidemiologically associated with diabetes and other metabolic disorders for many decades, it is only recently that there has been a better understanding of the underlying molecular mechanisms. Experimental circadian disruption, via manipulation of environmental or genetic factors using gene-deletion mouse models, has demonstrated the importance of circadian rhythms in whole body metabolism. Genetic disruption of core clock genes, specifically in the β-cells in mice, have, now demonstrated the importance of the intrinsic β-cell clock in regulating function. Recent work has also shown the interaction of the circadian clock and enhancers in β-cells, indicating a highly integrated regulation of transcription and cellular function by the circadian clock. Disruption of either the whole body or only the β-cell clock leads to significant impairment of mitochondrial function, uncoupling, impaired vesicular transport, oxidative stress in β-cells and finally impaired glucose-stimulated insulin secretion and diabetes. In this review, we explore the role of the circadian clock in mitigating oxidative stress and preserving β-cell function. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Cell Density Plays a Critical Role in Ex Vivo Expansion of T Cells for Adoptive Immunotherapy

    Directory of Open Access Journals (Sweden)

    Qiangzhong Ma

    2010-01-01

    Full Text Available The successful ex vivo expansion of a large numbers of T cells is a prerequisite for adoptive immunotherapy. In this study, we found that cell density had important effects on the process of expansion of T cells in vitro. Resting T cells were activated to expand at high cell density but failed to be activated at low cell density. Activated T cells (ATCs expanded rapidly at high cell density but underwent apoptosis at low cell density. Our studies indicated that low-cell-density related ATC death is mediated by oxidative stress. Antioxidants N-acetylcysteine, catalase, and albumin suppressed elevated reactive oxygen species (ROS levels in low-density cultures and protected ATCs from apoptosis. The viability of ATCs at low density was preserved by conditioned medium from high-density cultures of ATCs in which the autocrine survival factor was identified as catalase. We also found that costimulatory signal CD28 increases T cell activation at lower cell density, paralleled by an increase in catalase secretion. Our findings highlight the importance of cell density in T cell activation, proliferation, survival and apoptosis and support the importance of maintaining T cells at high density for their successful expansion in vitro.

  11. Vasculogenic Mimicry of HT1080 Tumour Cells In Vivo: Critical Role of HIF-1α-Neuropilin-1 Axis

    Science.gov (United States)

    Misra, Roli M.; Bajaj, Manmohan S.; Kale, Vaijayanti P.

    2012-01-01

    HT1080 - a human fibrosarcoma-derived cell line – forms aggressive angiogenic tumours in immuno-compromised mice. In spite of its extensive use as a model of tumour angiogenesis, the molecular event(s) initiating the angiogenic program in these cells are not known. Since hypoxia stimulates tumour angiogenesis, we examined the hypoxia-induced events evoked in these cells. In contrast to cells grown under normoxic conditions, hypoxia-primed (1% O2) HT1080 cells formed robust tubules on growth factor-reduced matrigel and formed significantly larger tumours in xenograft models in a chetomin-sensitive manner, indicating the role of HIF-1α-mediated transcription in these processes. Immuno-histochemical analyses of tumours formed by GFP-expressing HT1080 cells clearly showed that the tumour cells themselves expressed various angiogenic markers including Neuropilin-1 (NRP-1) and formed functional vessels containing red blood cells, thereby unambiguously demonstrating the vasculogenic mimicry of HT1080 cells in vivo. Experiments performed with the HT1080 cells stably transfected with plasmid constructs expressing shNRP-1 or full-length NRP-1 clearly established that the HIF1α-mediated up-regulation of NRP-1 played a deterministic role in the process. Hypoxia-exposure resulted in an up-regulation of c-Myc and OCT3/4 and a down-regulation of KLF4 mRNAs, suggesting their involvement in the tumour formation and angiogenesis. However, silencing of NRP-1 alone, though not affecting proliferation in culture, was sufficient to abrogate the tumour formation completely; clearly establishing that the hypoxia-mediated HIF-1α-dependent up-regulation of NRP-1 is a critical molecular event involved in the vasculogenic mimicry and tumor formation by HT1080 cells in vivo. PMID:23185562

  12. Early B-cell factor 1 (EBF1) is critical for transcriptional control of SLAMF1 gene in human B cells.

    Science.gov (United States)

    Schwartz, Anton M; Putlyaeva, Lidia V; Covich, Milica; Klepikova, Anna V; Akulich, Kseniya A; Vorontsov, Ilya E; Korneev, Kirill V; Dmitriev, Sergey E; Polanovsky, Oleg L; Sidorenko, Svetlana P; Kulakovskiy, Ivan V; Kuprash, Dmitry V

    2016-10-01

    Signaling lymphocytic activation molecule family member 1 (SLAMF1)/CD150 is a co-stimulatory receptor expressed on a variety of hematopoietic cells, in particular on mature lymphocytes activated by specific antigen, costimulation and cytokines. Changes in CD150 expression level have been reported in association with autoimmunity and with B-cell chronic lymphocytic leukemia. We characterized the core promoter for SLAMF1 gene in human B-cell lines and explored binding sites for a number of transcription factors involved in B cell differentiation and activation. Mutations of SP1, STAT6, IRF4, NF-kB, ELF1, TCF3, and SPI1/PU.1 sites resulted in significantly decreased promoter activity of varying magnitude, depending on the cell line tested. The most profound effect on the promoter strength was observed upon mutation of the binding site for Early B-cell factor 1 (EBF1). This mutation produced a 10-20 fold drop in promoter activity and pinpointed EBF1 as the master regulator of human SLAMF1 gene in B cells. We also identified three potent transcriptional enhancers in human SLAMF1 locus, each containing functional EBF1 binding sites. Thus, EBF1 interacts with specific binding sites located both in the promoter and in the enhancer regions of the SLAMF1 gene and is critical for its expression in human B cells. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. PDX1, Neurogenin-3, and MAFA: critical transcription regulators for beta cell development and regeneration

    Directory of Open Access Journals (Sweden)

    Yaxi Zhu

    2017-11-01

    Full Text Available Abstract Transcription factors regulate gene expression through binding to specific enhancer sequences. Pancreas/duodenum homeobox protein 1 (PDX1, Neurogenin-3 (NEUROG3, and V-maf musculoaponeurotic fibrosarcoma oncogene homolog A (MAFA are transcription factors critical for beta cell development and maturation. NEUROG3 is expressed in endocrine progenitor cells and controls islet differentiation and regeneration. PDX1 is essential for the development of pancreatic exocrine and endocrine cells including beta cells. PDX1 also binds to the regulatory elements and increases insulin gene transcription. Likewise, MAFA binds to the enhancer/promoter region of the insulin gene and drives insulin expression in response to glucose. In addition to those natural roles in beta cell development and maturation, ectopic expression of PDX1, NEUROG3, and/or MAFA has been successfully used to reprogram various cell types into insulin-producing cells in vitro and in vivo, such as pancreatic exocrine cells, hepatocytes, and pluripotent stem cells. Here, we review biological properties of PDX1, NEUROG3, and MAFA, and their applications and limitations for beta cell regenerative approaches. The primary source literature for this review was acquired using a PubMed search for articles published between 1990 and 2017. Search terms include diabetes, insulin, trans-differentiation, stem cells, and regenerative medicine.

  14. Ontogeny and function of murine epidermal Langerhans cells.

    Science.gov (United States)

    Kaplan, Daniel H

    2017-09-19

    Langerhans cells (LCs) are epidermis-resident antigen-presenting cells that share a common ontogeny with macrophages but function as dendritic cells (DCs). Their development, recruitment and retention in the epidermis is orchestrated by interactions with keratinocytes through multiple mechanisms. LC and dermal DC subsets often show functional redundancy, but LCs are required for specific types of adaptive immune responses when antigen is concentrated in the epidermis. This Review will focus on those developmental and functional properties that are unique to LCs.

  15. Dnd Is a Critical Specifier of Primordial Germ Cells in the Medaka Fish

    Directory of Open Access Journals (Sweden)

    Ni Hong

    2016-03-01

    Full Text Available Primordial germ cell (PGC specification occurs early in development. PGC specifiers have been identified in Drosophila, mouse, and human but remained elusive in most animals. Here we identify the RNA-binding protein Dnd as a critical PGC specifier in the medaka fish (Oryzias latipes. Dnd depletion specifically abolished PGCs, and its overexpression boosted PGCs. We established a single-cell culture procedure enabling lineage tracing in vitro. We show that individual blastomeres from cleavage embryos at the 32- and 64-cell stages are capable of PGC production in culture. Importantly, Dnd overexpression increases PGCs via increasing PGC precursors. Strikingly, dnd RNA forms prominent particles that segregate asymmetrically. Dnd concentrates in germ plasm and stabilizes germ plasm RNA. Therefore, Dnd is a critical specifier of fish PGCs and utilizes particle partition as a previously unidentified mechanism for asymmetric segregation. These findings offer insights into PGC specification and manipulation in medaka as a lower vertebrate model.

  16. Defining the functional states of Th17 cells

    OpenAIRE

    Lee, Youjin; Kuchroo, Vijay

    2015-01-01

    The molecular mechanisms governing T helper (Th) cell differentiation and function have revealed a complex network of transcriptional and protein regulators. Cytokines not only initiate the differentiation of CD4 Th cells into subsets but also influence the identity, plasticity and effector function of a T cell. Of the subsets, Th17 cells, named for producing interleukin 17 (IL-17) as their signature cytokine, secrete a cohort of other cytokines, including IL-22, IL-21, IL-10, IL-9, IFNγ, and...

  17. Phenotypic and functional plasticity of cells of innate immunity: macrophages, mast cells and neutrophils

    DEFF Research Database (Denmark)

    Galli, Stephen J; Borregaard, Niels; Wynn, Thomas A

    2011-01-01

    Hematopoietic cells, including lymphoid and myeloid cells, can develop into phenotypically distinct 'subpopulations' with different functions. However, evidence indicates that some of these subpopulations can manifest substantial plasticity (that is, undergo changes in their phenotype and function...

  18. Deficiencies in mitochondrial DNA compromise the survival of yeast cells at critically high temperatures.

    Science.gov (United States)

    Zubko, Elena I; Zubko, Mikhajlo K

    2014-01-01

    To address possible roles of mitochondrial genes in adaptation of eukaryotic cells to critical temperatures, we compared thermotolerance of mitochondrial rho mutants and wild type cells of six rho positive yeast species: Candida glabrata, Saccharomyces bayanus, Saccharomyces cerevisiae, Saccharomyces eubayanus, Saccharomyces paradoxus and Saccharomyces pastorianus. All rho mutants manifested compromised thermotolerance as a common phenotype. Analysis of viabilities at critical temperatures (32-45 °C) showed the reduction of maximum permissive temperatures (MPTs) in all rho mutants in comparison to their wild type counterparts. Degrees of the compromised thermotolerance depended on maximum permissive temperatures for wild type cells: the highest levels of MPT reductions for rho mutants took place in species and strains with highest MPTs for wild types. Short term exposures of S. cerevisiae cells (up to 3.5h) at non-permissive temperatures (45 °C and 50 °C) also lead to more rapid cell death of rho mutants as compared to wild type cells. We conclude that: (1) compromised thermotolerance could be a generic phenotypic property of rho mutants; (2) the enhanced thermotolerance of cells possessing mitochondrial genomes could be one of selective advantages in adaptation to environmental factors, in particular to enhanced temperatures. Copyright © 2013 Elsevier GmbH. All rights reserved.

  19. Transfusion of leukocyte-depleted red blood cells is not a risk factor for nosocomial infections in critically ill children

    NARCIS (Netherlands)

    van der Wal, Judith; van Heerde, Marc; Markhorst, Dick G.; Kneyber, Martin C. J.

    Objectives: Transfusion of red blood cells is increasingly linked with adverse outcomes in critically ill children. We tested the hypothesis that leukocyte-depleted red blood cell transfusions were independently associated with increased development of bloodstream infections, ventilator-associated

  20. Frank A. Beach award: programming of neuroendocrine function by early-life experience: a critical role for the immune system.

    Science.gov (United States)

    Bilbo, Staci D

    2013-05-01

    Many neuropsychiatric disorders are associated with a strong dysregulation of the immune system, and several have a striking etiology in development as well. Our recent evidence using a rodent model of neonatal Escherichia coli infection has revealed novel insight into the mechanisms underlying cognitive deficits in adulthood, and suggests that the early-life immune history of an individual may be critical to understanding the relative risk of developing later-life mental health disorders in humans. A single neonatal infection programs the function of immune cells within the brain, called microglia, for the life of the rodent such that an adult immune challenge results in exaggerated cytokine production within the brain and associated cognitive deficits. I describe the important role of the immune system, notably microglia, during brain development, and discuss some of the many ways in which immune activation during early brain development can affect the later-life outcomes of neural function, immune function, and cognition. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Cell survival following alpha particle irradiation: critical sites and implications for carcinogenesis

    International Nuclear Information System (INIS)

    Lloyd, E.L.; Gemmell, M.A.; Henning, C.B.; Gemmell, D.S.; Zabransky, B.J.

    1976-01-01

    In experiments in which mammalian cells were irradiated with 5.6 MeV alpha particles from a Tandem Van de Graaff machine we have confirmed the finding of others that the mean lethal dose (D 0 ) is about 100 rad, but by measurements of the area of the cell nuclei as irradiated we found that this mean lethal dose corresponds not to 1, as expected, but to about 27 alpha particles per cell nucleus. (The exact number appears to change slightly with cell passage number.) This allows for the possibility that the direct action of alpha particles on the nucleus may be the important event in carcinogenesis, a theory which was previously difficult to accept if a single particle hitting the nucleus anywhere was considered to be lethal. Evidence is presented to implicate the nucleolus as a possible critical site for the inhibition of reproductive integrity of the cell

  2. Ferroelectric critical size and vortex domain structures of PbTiO3 nanodots: A density functional theory study

    Science.gov (United States)

    Wang, Xiaoyuan; Yan, Yabin; Shimada, Takahiro; Wang, Jie; Kitamura, Takayuki

    2018-03-01

    The ferroelectric critical size and microscopic domain structure of PbTiO3 nanodots with unit cells of N × N × N (N = 1-3) have been investigated by ab initio (first-principles) density functional theory calculations. Nanodots with PbO and TiO surface terminations are investigated, and the ground state of TiO-terminated nanodots is found to be paraelectric regardless of the size. However, for PbO-terminated nanodots, the ferroelectric state is energetically favorable even in the smallest nanodot, indicating the absence of an intrinsic critical size for ferroelectricity in the nanodot structure. Moreover, the distributions of polarizations in nanodots with different sizes are analyzed. The vortex polarizations rotating around both the central [001] axis and diagonal [1 1 ¯ 1 ] directions of nanodots can stably exist. The vortex polarization arises from the opposite rotation between the cations and anions around the [001] and the [1 1 ¯ 1 ] directions of nanodots, respectively. On the other hand, the toroidal moments of vortex polarizations both around the [001] and [1 1 ¯ 1 ] directions increase with the increment of nanodot size, and these vortex polarizations are energetically favorable in small and large nanodots, respectively.

  3. Allergen recognition by innate immune cells: critical role of dendritic and epithelial cells

    Directory of Open Access Journals (Sweden)

    Fabian eSalazar

    2013-11-01

    Full Text Available Allergy is an exacerbated response of the immune system against non-self-proteins called allergens and is typically characterized by biased type-2 T helper cell and deleterious IgE mediated immune responses. The allergic cascade starts with the recognition of allergens by antigen presenting cells, mainly dendritic cells, culminating in mast cell sensitization and triggering. Dendritic cells have been demonstrated to play a crucial role in orchestrating allergic diseases. Using different C-type lectin receptors dendritic cells are able to recognize and internalize a number of allergens from diverse sources leading to sensitization. Furthermore, there is increasing evidence highlighting the role of epithelial cells in triggering and modulating immune responses to allergens. As well as providing a physical barrier, epithelial cells can interact with allergens and influence dendritic cells behaviour through the release of a number of Th2 promoting cytokines. In this review we will summarise current understanding of how allergens are recognised by dendritic cells and epithelial cells and what are the consequences of such interaction in the context of allergic sensitisation and downstream events leading to allergic inflammation. Better understanding of the molecular mechanisms of allergen recognition and associated signalling pathways could enable developing more effective therapeutic strategies that target the initial steps of allergic sensitisation hence hindering development or progression of allergic diseases.

  4. Mesenchymal stem cell expression of SDF-1β synergizes with BMP-2 to augment cell-mediated healing of critical-sized mouse calvarial defects.

    Science.gov (United States)

    Herberg, Samuel; Aguilar-Perez, Alexandra; Howie, R Nicole; Kondrikova, Galina; Periyasamy-Thandavan, Sudharsan; Elsalanty, Mohammed E; Shi, Xingming; Hill, William D; Cray, James J

    2017-06-01

    Bone has the potential for spontaneous healing. This process, however, often fails in patients with comorbidities. Tissue engineering combining functional cells, biomaterials and osteoinductive cues may provide alternative treatment strategies. We have recently demonstrated that stromal cell-derived factor-1β (SDF-1β) works in concert with bone morphogenetic protein-2 (BMP-2) to potentiate osteogenic differentiation of bone marrow-derived mesenchymal stem/stromal cells (BMSCs). Here, we test the hypothesis that SDF-1β overexpressed in Tet-Off-SDF-1β BMSCs, delivered on acellular dermal matrix (ADM), synergistically augments BMP-2-induced healing of critical-sized mouse calvarial defects. BMSC therapies alone showed limited bone healing, which was increased with co-delivery of BMP-2. This was further enhanced in Tet-Off-SDF-1β BMSCs + BMP-2. Only limited BMSC retention on ADM constructs was observed after 4 weeks in vivo, which was increased with BMP-2 co-delivery. In vitro cell proliferation studies showed that supplementing BMP-2 to Tet-Off BMSCs significantly increased the cell number during the first 24 h. Consequently, the increased cell numbers decreased the detectable BMP-2 levels in the medium, but increased cell-associated BMP-2. The data suggest that SDF-1β provides synergistic effects supporting BMP-2-induced, BMSC-mediated bone formation and appears suitable for optimization of bone augmentation in combination therapy protocols. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  5. X-linked inhibitor of apoptosis regulates T cell effector function

    DEFF Research Database (Denmark)

    Zehntner, Simone P; Bourbonnière, Lyne; Moore, Craig S

    2007-01-01

    autoimmune encephalomyelitis and prevented relapses. Prophylactic treatment also reduced XIAP expression and prevented disease. Random or 5-base mismatched ASO was not inhibitory, and ASO-XIAP did not affect T cell priming. In ASO-XIAP-treated animals, infiltrating cells and inflammatory foci were...... dramatically reduced within the CNS. Flow cytometry showed an 88-93% reduction in T cells. The proportion of TUNEL(+) apoptotic CD4(+) T cells in the CNS was increased from cells in the CNS increased. Neurons...... and oligodendrocytes were not affected; neither did apoptosis increase in liver, where XIAP knockdown also occurred. ASO-XIAP increased susceptibility of T cells to activation-induced apoptosis in vitro. Our results identify XIAP as a critical controller of apoptotic susceptibility of effector T cell function...

  6. Functional disability and suicidal behavior in middle-aged and older adults: A systematic critical review.

    Science.gov (United States)

    Lutz, Julie; Fiske, Amy

    2018-02-01

    Middle-aged and older adults have elevated rates of suicide around the globe, but there is a paucity of knowledge about risk factors for suicide in these age groups. One possible risk factor may be functional disability, which is more common at later ages. The current systematic critical review examined findings regarding the associations between functional disability and suicidal behavior (suicidal ideation, suicide attempts, and death by suicide) in middle-aged and older adults (i.e. age 50 and older). Forty-five studies were found that examined these associations. The majority of studies supported a significant association between functional disability and suicidal ideation. In addition, findings to date strongly suggest that depression serves as a mediator of the association between functional disability and suicidal ideation, though most studies did not directly test for mediation. Firm conclusions regarding suicide attempts and death by suicide, as well as mediation, cannot be drawn due to a relative lack of research in these areas. The association between functional disability and suicidal behavior suggests an important area for prevention and intervention among middle-aged and older adults, but additional research is necessary to clarify the specifics of these associations and examine appropriate intervention strategies. Important future directions for research in this area include the direct comparison of associations of risk factors with different types of suicidal behavior, greater use of longitudinal data with multiple time points, and further examination of potential mediators and moderators of the association between functional disability and suicidal behavior. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Visualizing chemical functionality in plant cell walls

    OpenAIRE

    Zeng, Yining; Himmel, Michael E.; Ding, Shi-You

    2017-01-01

    Understanding plant cell wall cross-linking chemistry and polymeric architecture is key to the efficient utilization of biomass in all prospects from rational genetic modification to downstream chemical and biological conversion to produce fuels and value chemicals. In fact, the bulk properties of cell wall recalcitrance are collectively determined by its chemical features over a wide range of length scales from tissue, cellular to polymeric architectures. Microscopic visualization of cell wa...

  8. Functional status after critical illness: agreement between patient and proxy assessments.

    Science.gov (United States)

    Ahasic, Amy M; Van Ness, Peter H; Murphy, Terrence E; Araujo, Katy L B; Pisani, Margaret A

    2015-05-01

    assessment of baseline functional status of older patients during and after intensive care unit (ICU) admission is often hampered by challenges related to the critical illness such as cognitive dysfunction, neuropsychological morbidity and pain. To explore the reliability of assessments by carefully chosen proxies, we designed a discriminating selection of proxies and evaluated agreement between patient and proxy responses by assessing activities of daily living (ADLs) at 1 month post-ICU discharge. patients ≥60 years old admitted to the medical ICU were enrolled in a prospective parent cohort studying delirium. Proxies were carefully screened at ICU admission to choose the best available respondent. Follow-up interviews, including instruments for ADLs, were conducted 1 month after ICU discharge. We examined 179 paired patient-proxy follow-up interviews. Kappa statistics assessed inter-observer agreement, and McNemar's exact test assessed response differences. patients averaged 73.3 ± 8.1 years old with 29% having evidence of cognitive impairment. Proxies were most commonly spouses (38%) or children (39%). Overall, there was substantial (κ ≥ 0.6) to excellent agreement (κ ≥ 0.8) between patients and proxies on assessment of all but one basic and one instrumental ADL. proxies carefully chosen at ICU admission show high levels of inter-observer agreement with older patients when assessing current functional status at 1 month post-ICU discharge. This motivates further study of proxy assessments that could be used earlier in critical illness to assess premorbid functional status. © The Author 2014. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Stormwater management network effectiveness and implications for urban watershed function: A critical review

    Science.gov (United States)

    Jefferson, Anne J.; Bhaskar, Aditi S.; Hopkins, Kristina G.; Fanelli, Rosemary; Avellaneda, Pedro M.; McMillan, Sara K.

    2017-01-01

    Deleterious effects of urban stormwater are widely recognized. In several countries, regulations have been put into place to improve the conditions of receiving water bodies, but planning and engineering of stormwater control is typically carried out at smaller scales. Quantifying cumulative effectiveness of many stormwater control measures on a watershed scale is critical to understanding how small-scale practices translate to urban river health. We review 100 empirical and modelling studies of stormwater management effectiveness at the watershed scale in diverse physiographic settings. Effects of networks with stormwater control measures (SCMs) that promote infiltration and harvest have been more intensively studied than have detention-based SCM networks. Studies of peak flows and flow volumes are common, whereas baseflow, groundwater recharge, and evapotranspiration have received comparatively little attention. Export of nutrients and suspended sediments have been the primary water quality focus in the United States, whereas metals, particularly those associated with sediments, have received greater attention in Europe and Australia. Often, quantifying cumulative effects of stormwater management is complicated by needing to separate its signal from the signal of urbanization itself, innate watershed characteristics that lead to a range of hydrologic and water quality responses, and the varying functions of multiple types of SCMs. Biases in geographic distribution of study areas, and size and impervious surface cover of watersheds studied also limit our understanding of responses. We propose hysteretic trajectories for how watershed function responds to increasing imperviousness and stormwater management. Even where impervious area is treated with SCMs, watershed function may not be restored to its predevelopment condition because of the lack of treatment of all stormwater generated from impervious surfaces; non-additive effects of individual SCMs; and

  10. Intravenous amino acid therapy for kidney function in critically ill patients: a randomized controlled trial.

    Science.gov (United States)

    Doig, Gordon S; Simpson, Fiona; Bellomo, Rinaldo; Heighes, Philippa T; Sweetman, Elizabeth A; Chesher, Douglas; Pollock, Carol; Davies, Andrew; Botha, John; Harrigan, Peter; Reade, Michael C

    2015-07-01

    Acute kidney injury (AKI) is characterized by severe loss of glomerular filtration rate (GFR) and is associated with a prolonged intensive care unit (ICU) stay and increased risk of death. No interventions have yet been shown to prevent AKI or preserve GFR in critically ill patients. Evidence from mammalian physiology and small clinical trials suggests higher amino acid intake may protect the kidney from ischemic insults and thus may preserve GFR during critical illness. To determine whether amino acid therapy, achieved through daily intravenous (IV) supplementation with standard amino acids, preserves kidney function in critically ill patients. Multicenter, phase II, randomized clinical trial conducted between December 2010 and February 2013 in the ICUs of 16 community and tertiary hospitals in Australia and New Zealand. Participants were adult critically ill patients expected to remain in the study ICU for longer than 2 days. Random allocation to receive a daily supplement of up to 100 g of IV amino acids or standard care. Duration of renal dysfunction (primary outcome); estimated GFR (eGFR) derived from creatinine; eGFR derived from cystatin C; urinary output; renal replacement therapy (RRT) use; fluid balance and other measures of renal function. 474 patients were enrolled and randomized (235 to standard care, 239 to IV amino acid therapy). At time of enrollment, patients allocated to receive amino acid therapy had higher APACHE II scores (20.2 ± 6.8 vs. 21.7 ± 7.6, P = 0.02) and more patients had pre-existing renal dysfunction (29/235 vs. 44/239, P = 0.07). Duration of renal dysfunction after enrollment did not differ between groups (mean difference 0.21 AKI days per 10 patient ICU days, 95 % CI -0.27 to 1.04, P = 0.45). Amino acid therapy significantly improved eGFR (treatment group × time interaction, P = 0.004), with an early peak difference of 7.7 mL/min/1.73 m(2) (95 % CI 1.0-14.5 mL/min/1.73 m(2), P = 0.02) on study day 4. Daily urine output was also

  11. Deficient natural killer cell function in preeclampsia

    Energy Technology Data Exchange (ETDEWEB)

    Alanen, A.; Lassila, O.

    1982-11-01

    Natural killer cell activity of peripheral blood lymphocytes was measured against K-562 target cells with a 4-hour /sup 51/Cr release assay in 15 primigravid women with preeclamptic symptoms. Nineteen primigravid women with an uncomplicated pregnancy and 18 nonpregnant women served as controls. The natural killer cell activity of preeclamptic women was observed to be significantly lower than that of both control groups. Natural killer cells in preeclamptic women responded normally to augmentation caused by interferon. These findings give further evidence for the participation of the maternal immune system in this pregnancy disorder.

  12. Methylglyoxal alters the function and stability of critical components of the protein quality control.

    Directory of Open Access Journals (Sweden)

    Carla Figueira Bento

    Full Text Available BACKGROUND: Increased production and accumulation of methylglyoxal (MGO, as well as increased modification of proteins by glycoxidation, are hallmarks of aging and diabetes. MGO was shown to modify proteins and to contribute to the accumulation of damaged proteins that can be toxic to cells. However, the effect of MGO on the cell systems responsible for repairing or degrading damaged proteins is still unclear. In this study, the effect of MGO on the function of the ubiquitin-proteasome system (UPS and on molecular chaperones, two cooperative mechanisms associated with protein quality control, was investigated. PRINCIPAL FINDINGS: In this work it is shown that treatment of cells with MGO leads to accumulation of ubiquitin conjugates and depletion of free ubiquitin. Moreover, MGO significantly decreases the proteolytic activity of the 20S proteasome. Data further shows that MGO decreases the levels of the molecular chaperones Hsc70 and Hsp90 and leads to accumulation of CHIP-, Hsp40- and ubiquitin-containing aggregates. The formation of large aggregates containing CHIP is a consequence of its binding to misfolded proteins and to molecular chaperones. Moreover, dysfunction of the chaperones/CHIP/UPS axis is associated with accumulation of oxidized and argpyrimidine-modified proteins, which is likely to be associated with decreased cell viability. Interestingly, data further shows that MGO-induced stress induces the activation of heat shock factor-1 (Hsf-1, the main transcription factor involved in the regulation of the expression of heat shock proteins (HSPs and cell response to stress. CONCLUSIONS: The data obtained in this work suggests that MGO impairs both the UPS and the protein quality control dependent on CHIP and molecular chaperones, leading to accumulation of toxic aggregates and increased cell death. However, these MGO-induced changes appear to elicit a response from the Hsf-1 system, which is crucial to help cells to cope with cellular

  13. Methylglyoxal alters the function and stability of critical components of the protein quality control.

    Science.gov (United States)

    Bento, Carla Figueira; Marques, Filipa; Fernandes, Rosa; Pereira, Paulo

    2010-09-24

    Increased production and accumulation of methylglyoxal (MGO), as well as increased modification of proteins by glycoxidation, are hallmarks of aging and diabetes. MGO was shown to modify proteins and to contribute to the accumulation of damaged proteins that can be toxic to cells. However, the effect of MGO on the cell systems responsible for repairing or degrading damaged proteins is still unclear. In this study, the effect of MGO on the function of the ubiquitin-proteasome system (UPS) and on molecular chaperones, two cooperative mechanisms associated with protein quality control, was investigated. In this work it is shown that treatment of cells with MGO leads to accumulation of ubiquitin conjugates and depletion of free ubiquitin. Moreover, MGO significantly decreases the proteolytic activity of the 20S proteasome. Data further shows that MGO decreases the levels of the molecular chaperones Hsc70 and Hsp90 and leads to accumulation of CHIP-, Hsp40- and ubiquitin-containing aggregates. The formation of large aggregates containing CHIP is a consequence of its binding to misfolded proteins and to molecular chaperones. Moreover, dysfunction of the chaperones/CHIP/UPS axis is associated with accumulation of oxidized and argpyrimidine-modified proteins, which is likely to be associated with decreased cell viability. Interestingly, data further shows that MGO-induced stress induces the activation of heat shock factor-1 (Hsf-1), the main transcription factor involved in the regulation of the expression of heat shock proteins (HSPs) and cell response to stress. The data obtained in this work suggests that MGO impairs both the UPS and the protein quality control dependent on CHIP and molecular chaperones, leading to accumulation of toxic aggregates and increased cell death. However, these MGO-induced changes appear to elicit a response from the Hsf-1 system, which is crucial to help cells to cope with cellular stress and to re-establish homeostasis.

  14. The Guard Cell Metabolome: Functions in Stomatal Movement and Global Food Security

    Directory of Open Access Journals (Sweden)

    Biswapriya eMisra

    2015-05-01

    Full Text Available Guard cells represent a unique single cell-type system for the study of cellular responses to abiotic and biotic perturbations that affect stomatal movement. Decades of effort through both classical physiological and functional genomics approaches have generated an enormous amount of information on the roles of individual metabolites in stomatal guard cell function and physiology. Recent application of metabolomics methods has produced a substantial amount of new information on metabolome control of stomatal movement. In conjunction with other ‘omics’ approaches, the knowledge-base is growing to reach a systems-level description of this single cell-type. Here we summarize current knowledge of the guard cell metabolome and highlight critical metabolites that bear significant impact on future engineering and breeding efforts to generate plants/crops that are resistant to environmental challenges and produce high yield and quality products for food and energy security.

  15. X-linked inhibitor of apoptosis regulates T cell effector function

    DEFF Research Database (Denmark)

    Zehntner, Simone P; Bourbonnière, Lyne; Moore, Craig S

    2007-01-01

    To understand how the balance between pro- and anti-apoptotic signals influences effector function in the immune system, we studied the X-linked inhibitor of apoptosis (XIAP), an endogenous regulator of cellular apoptosis. Real-time PCR showed increased XIAP expression in blood of mice...... and oligodendrocytes were not affected; neither did apoptosis increase in liver, where XIAP knockdown also occurred. ASO-XIAP increased susceptibility of T cells to activation-induced apoptosis in vitro. Our results identify XIAP as a critical controller of apoptotic susceptibility of effector T cell function...

  16. Nurses' competences in the critical care of children undergoing hematopoietic stem cell transplantation

    Directory of Open Access Journals (Sweden)

    Marianna Ferreira

    2017-11-01

    Full Text Available This is a descriptive study, with qualitative data analysis, in order to identify and analyze the experiences and competencies required by nurses in the care of transplanted child, who demand critical care. Nine nurses were interviewed. We analyzed the data according to the procedures for qualitative content analysis, and then we elaborated the following themes: Critical care to the transplanted child: a double challenge for the nurse; Nurses' competences for the care towards the critically ill child submitted to hematopoietic stem cell transplantation (HSCT. The identified competencies based on scientific knowledge, skills and natural abilities and relate to specific knowledge about pediatric HSCT; technical-scientific, interactive and communication skills; management of material resources and equipment; emotional control, empathy and leadership. Such competences help in the construction of a specific profile for the care offered to this clientele, with a view to therapeutic success.

  17. Bioactivity of enoxaparin in critically ill patients with normal renal function.

    Science.gov (United States)

    Gouya, Ghazaleh; Palkovits, Stefan; Kapiotis, Stylianos; Madl, Christian; Locker, Gottfried; Stella, Alexander; Wolzt, Michael; Heinz, Gottfried

    2012-11-01

    Venous thromboembolism is a frequent complication in critically ill patients that has a negative impact on patient outcomes. Critically ill patients have significantly lower plasma anti-factor-Xa activity levels compared with control patients after administration of subcutaneous heparin. The clinical relevance of the different anti-factor-Xa levels after prophylactic doses of low molecular weight heparin (LMWH) in critically ill patients is not completely understood. The standard dose of 40 mg enoxaparin led to a significant increase in anti-FXa levels in this selected cohort of ICU patients with normal renal function. This study found only subtle pharmacokinetic differences, but a comparable pharmacodynamic action, after enoxaparin administration in critically ill and normal medical ward patients. Thrombin generation with TGA RC-low and TGARC-high reagents was significantly reduced in ICU and normal ward patients after receiving LMWH. Both readouts appear equally useful for estimating the pharmacodynamics of enoxaparin. The ex vivo model of thrombosis was used for the first time in patients to evaluate the anti-thrombotic activity of LMWH. This method did not show any difference in thrombus formation after administration of enoxaparin in the individual group of patients. In critically ill patients, reduced anti-FXa plasma activity following subcutaneous administration of enoxaparin or nadroparin has been described. In this study, we aimed to investigate the bioactivity of enoxaparin in critically ill patients and controls. A prospective, controlled, open label study was performed on a medical intensive care unit (ICU) and a general medical ward. Fifteen ICU patients (male = 12, median age 52 years [IQR 40-65], with a median Simplified Acute Physiology Score of 30 [IQR 18-52]) and sex- and age-matched medical ward patients were included. The anti-FXa plasma activity was measured after a single subcutaneous dose of40 mg enoxaparin. The thrombus size of a clot formed

  18. Aberrant Expression of Functional BAFF-System Receptors by Malignant B-Cell Precursors Impacts Leukemia Cell Survival

    Science.gov (United States)

    Maia, Sara; Pelletier, Marc; Ding, Jixin; Hsu, Yen-Ming; Sallan, Stephen E.; Rao, Sambasiva P.; Nadler, Lee M.; Cardoso, Angelo A.

    2011-01-01

    Despite exhibiting oncogenic events, patient's leukemia cells are responsive and dependent on signals from their malignant bone marrow (BM) microenvironment, which modulate their survival, cell cycle progression, trafficking and resistance to chemotherapy. Identification of the signaling pathways mediating this leukemia/microenvironment interplay is critical for the development of novel molecular targeted therapies. We observed that primary leukemia B-cell precursors aberrantly express receptors of the BAFF-system, BAFF-R, BCMA, and TACI. These receptors are functional as their ligation triggers activation of NF-κB, MAPK/JNK, and Akt signaling. Leukemia cells express surface BAFF and APRIL ligands, and soluble BAFF is significantly higher in leukemia patients in comparison to age-matched controls. Interestingly, leukemia cells also express surface APRIL, which seems to be encoded by APRIL-δ, a novel isoform that lacks the furin convertase domain. Importantly, we observed BM microenvironmental cells express the ligands BAFF and APRIL, including surface and secreted BAFF by BM endothelial cells. Functional studies showed that signals through BAFF-system receptors impact the survival and basal proliferation of leukemia B-cell precursors, and support the involvement of both homotypic and heterotypic mechanisms. This study shows an unforeseen role for the BAFF-system in the biology of precursor B-cell leukemia, and suggests that the target disruption of BAFF signals may constitute a valid strategy for the treatment of this cancer. PMID:21687682

  19. Aberrant expression of functional BAFF-system receptors by malignant B-cell precursors impacts leukemia cell survival.

    Directory of Open Access Journals (Sweden)

    Sara Maia

    Full Text Available Despite exhibiting oncogenic events, patient's leukemia cells are responsive and dependent on signals from their malignant bone marrow (BM microenvironment, which modulate their survival, cell cycle progression, trafficking and resistance to chemotherapy. Identification of the signaling pathways mediating this leukemia/microenvironment interplay is critical for the development of novel molecular targeted therapies.We observed that primary leukemia B-cell precursors aberrantly express receptors of the BAFF-system, BAFF-R, BCMA, and TACI. These receptors are functional as their ligation triggers activation of NF-κB, MAPK/JNK, and Akt signaling. Leukemia cells express surface BAFF and APRIL ligands, and soluble BAFF is significantly higher in leukemia patients in comparison to age-matched controls. Interestingly, leukemia cells also express surface APRIL, which seems to be encoded by APRIL-δ, a novel isoform that lacks the furin convertase domain. Importantly, we observed BM microenvironmental cells express the ligands BAFF and APRIL, including surface and secreted BAFF by BM endothelial cells. Functional studies showed that signals through BAFF-system receptors impact the survival and basal proliferation of leukemia B-cell precursors, and support the involvement of both homotypic and heterotypic mechanisms.This study shows an unforeseen role for the BAFF-system in the biology of precursor B-cell leukemia, and suggests that the target disruption of BAFF signals may constitute a valid strategy for the treatment of this cancer.

  20. A synthetic three-dimensional niche system facilitates generation of functional hematopoietic cells from human-induced pluripotent stem cells

    Directory of Open Access Journals (Sweden)

    Yulin Xu

    2016-09-01

    Full Text Available Abstract Background The efficient generation of hematopoietic stem cells (HSCs from human-induced pluripotent stem cells (iPSCs holds great promise in personalized transplantation therapies. However, the derivation of functional and transplantable HSCs from iPSCs has had very limited success thus far. Methods We developed a synthetic 3D hematopoietic niche system comprising nanofibers seeded with bone marrow (BM-derived stromal cells and growth factors to induce functional hematopoietic cells from human iPSCs in vitro. Results Approximately 70 % of human CD34+ hematopoietic cells accompanied with CD43+ progenitor cells could be derived from this 3D induction system. Colony-forming-unit (CFU assay showed that iPSC-derived CD34+ cells formed all types of hematopoietic colonies including CFU-GEMM. TAL-1 and MIXL1, critical transcription factors associated with hematopoietic development, were expressed during the differentiation process. Furthermore, iPSC-derived hematopoietic cells gave rise to both lymphoid and myeloid lineages in the recipient NOD/SCID mice after transplantation. Conclusions Our study underscores the importance of a synthetic 3D niche system for the derivation of transplantable hematopoietic cells from human iPSCs in vitro thereby establishing a foundation towards utilization of human iPSC-derived HSCs for transplantation therapies in the clinic.

  1. UPF2 is a critical regulator of liver development, function and regeneration

    DEFF Research Database (Denmark)

    Thoren, Lina A; Nørgaard, Gitte A; Weischenfeldt, Joachim

    2010-01-01

    BACKGROUND: Nonsense-mediated mRNA decay (NMD) is a post-transcriptional RNA surveillance process that facilitates the recognition and destruction of mRNAs bearing premature terminations codons (PTCs). Such PTC-containing (PTC+) mRNAs may arise from different processes, including erroneous proces....... CONCLUSION/SIGNIFICANCE: Collectively, our data demonstrate the critical role of the NMD pathway in liver development, function and regeneration and highlights the importance of NMD for mammalian biology....... regulatory potential of the NMD pathway in mammals will require the functional assessment of NMD in different tissues. METHODOLOGY/PRINCIPAL FINDINGS: Here we use mouse genetics to address the role of UPF2, a core NMD component, in the development, function and regeneration of the liver. We find that loss...... of NMD during fetal liver development is incompatible with postnatal life due to failure of terminal differentiation. Moreover, deletion of Upf2 in the adult liver results in hepatosteatosis and disruption of liver homeostasis. Finally, NMD was found to be absolutely required for liver regeneration...

  2. Proinflammatory cytokines decrease the expression of genes critical for RPE function.

    Science.gov (United States)

    Kutty, R Krishnan; Samuel, William; Boyce, Kaifa; Cherukuri, Aswini; Duncan, Todd; Jaworski, Cynthia; Nagineni, Chandrasekharam N; Redmond, T Michael

    2016-01-01

    Proinflammatory cytokines interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), and interleukin-1 beta (IL-1β) secreted by infiltrating lymphocytes or macrophages may play a role in triggering RPE dysfunction associated with age-related macular degeneration (AMD). Binding of these proinflammatory cytokines to their specific receptors residing on the RPE cell surface can activate signaling pathways that, in turn, may dysregulate cellular gene expression. The purpose of the present study was to investigate whether IFN-γ, TNF-α, and IL-1β have an adverse effect on the expression of genes essential for RPE function, employing the RPE cell line ARPE-19 as a model system. ARPE-19 cells were cultured for 3-4 months until they exhibited epithelial morphology and expressed mRNAs for visual cycle genes. The differentiated cells were treated with IFN-γ, TNF-α, and/or IL-1β, and gene expression was analyzed with real-time PCR analysis. Western immunoblotting was employed for the detection of proteins. Proinflammatory cytokines (IFN-γ + TNF-α + IL-1β) greatly increased the expression of chemokines and cytokines in cultured ARPE-19 cells that exhibited RPE characteristics. However, this response was accompanied by markedly decreased expression of genes important for RPE function, such as CDH1 , RPE65 , RDH5 , RDH10 , TYR , and MERTK . This was associated with decreased expression of the genes MITF , TRPM1 , and TRPM3 , as well as microRNAs miR-204 and miR-211, which are known to regulate RPE-specific gene expression. The decreased expression of the epithelial marker gene CDH1 was associated with increased expression of mesenchymal marker genes ( CDH2 , VIM , and CCND1 ) and epithelial-mesenchymal transition (EMT) promoting transcription factor genes ( ZEB1 and SNAI1 ). RPE cells exposed to proinflammatory cytokines IFN-γ, TNF-α, and IL-1β showed decreased expression of key genes involved in the visual cycle, epithelial morphology, and phagocytosis. This

  3. Critical role of mast cells and peroxisome proliferator-activated receptor gamma (PPARγ) in the induction of myeloid-derived suppressor cells by marijuana cannabidiol in vivo

    Science.gov (United States)

    Hegde, Venkatesh L.; Singh, Udai P.; Nagarkatti, Prakash S.; Nagarkatti, Mitzi

    2015-01-01

    Cannabidiol (CBD) is a natural non-psychotropic cannabinoid from marijuana (Cannabis sativa) with anti-epileptic and anti-inflammatory properties. Effect of CBD on naïve immune system is not precisely understood. In this study, we observed that administering CBD into naïve mice triggers robust induction of CD11b+Gr-1+ MDSC in the peritoneum, which expressed functional Arg1, and potently suppressed T cell proliferation ex vivo. Further, CBD-MDSC suppressed LPS-induced acute inflammatory response upon adoptive transfer in vivo. CBD-induced suppressor cells were comprised of CD11b+Ly6-G+Ly6-C+ granulocytic and CD11b+Ly6-G−Ly6-C+ monocytic subtypes, with monocytic MDSC exhibiting higher T cell suppressive function. Induction of MDSC by CBD was markedly attenuated in Kit-mutant (KitW/W-v) mast cell-deficient mice. MDSC response was reconstituted upon transfer of WT bone marrow-derived mast cells in KitW/W-v mice suggesting the key role of cKit (CD117) as well as mast cells. Moreover, mast cell activator compound 48/80 induced significant levels of MDSC in vivo. CBD administration in mice induced G-CSF, CXCL1 and M-CSF, but not GM-CSF. G-CSF was found to play a key role in MDSC mobilization inasmuch as neutralizing G-CSF caused a significant decrease in MDSC. Lastly, CBD enhanced the transcriptional activity of PPARγ in luciferase reporter assay, and PPARγ selective antagonist completely inhibited MDSC induction in vivo suggesting its critical role. Together, the results suggest that CBD may induce activation of PPARγ in mast cells leading to secretion of G-CSF and consequent MDSC mobilization. CBD being a major component of Cannabis, our study indicates that marijuana may modulate or dysregulate the immune system by mobilizing MDSC. PMID:25917103

  4. A vibrating membrane bioreactor operated at supra- and sub-critical flux: Influence of extracellular polymeric substances from yeast cells

    DEFF Research Database (Denmark)

    Beier, Søren Prip; Jonsson, Gunnar Eigil

    2007-01-01

    A vibrating membrane bioreactor, in which the fouling problems are reduced by vibrating a hollow fiber membrane module, has been tested in constant flux microfiltration above (supra-critical) and below (sub-critical) an experimentally determined critical flux. Suspensions of bakers yeast cells were...... is continually washed out during supra-critical flux operation whereas the washing out at sub-critical flux operation is not observed. This might be due to locally different hydrodynamic conditions at the membrane surface and pore entrances at supra- and sub-critical flux respectively....

  5. Generation of functional organs from stem cells

    Directory of Open Access Journals (Sweden)

    Yunying Liu

    2013-01-01

    Full Text Available We are now well entering the exciting era of stem cells. Potential stem cell therapy holds great promise for the treatment of many diseases such as stroke, traumatic brain injury, Alzheimer's disease, Parkinson's disease, amyotrophic lateral-sclerosis, myocardial infarction, muscular dystrophy, diabetes, and etc. It is generally believed that transplantation of specific stem cells into the injured tissue to replace the lost cells is an effective way to repair the tissue. In fact, organ transplantation has been successfully practiced in clinics for liver or kidney failure. However, the severe shortage of donor organs has been a major obstacle for the expansion of organ transplantation programs. Toward that direction, generation of transplantable organs using stem cells is a desirable approach for organ replacement and would be of great interest for both basic and clinical scientists. Here we review recent progress in the field of organ generation using various methods including single adult tissue stem cells, a blastocyst complementation system, tissue decellularization/recellularization and a combination of stem cells and tissue engineering.

  6. Critical parameters in the MCF-7 cell proliferation bioassay (E-Screen)

    DEFF Research Database (Denmark)

    Rasmussen, Thomas Høj; Nielsen, Jesper Bo

    2002-01-01

    of hormone-free controls. In the highly responsive MCF-7 BUS cell line, we evaluated critical assay parameters for test performance, including growth conditions, initial seeding densities and differences in growth stimulation in medium containing human serum or fetal calf serum as well as appropriate...... solvents for oestrogen-mimicking compounds. Modifications significantly reduced the labour-intensive steps and overall assay costs without affecting the sensitivity of the assay. Using this optimized test regimen, the responsiveness of treated MCF-7 BUS cells was consistently increased up to 11-fold over...

  7. Bone marrow transplantations to study gene function in hematopoietic cells

    NARCIS (Netherlands)

    de Winther, Menno P. J.; Heeringa, Peter

    2011-01-01

    Immune cells are derived from hematopoietic stem cells in the bone marrow. Experimental replacement of bone marrow offers the unique possibility to replace immune cells, to study gene function in mouse models of disease. Over the past decades, this technique has been used extensively to study, for

  8. Critical role of constitutive type I interferon response in bronchial epithelial cell to influenza infection.

    Directory of Open Access Journals (Sweden)

    Alan C-Y Hsu

    Full Text Available Innate antiviral responses in bronchial epithelial cells (BECs provide the first line of defense against respiratory viral infection and the effectiveness of this response is critically dependent on the type I interferons (IFNs. However the importance of the antiviral responses in BECs during influenza infection is not well understood. We profiled the innate immune response to infection with H3N2 and H5N1 virus using Calu-3 cells and primary BECs to model proximal airway cells. The susceptibility of BECs to influenza infection was not solely dependent on the sialic acid-bearing glycoprotein, and antiviral responses that occurred after viral endocytosis was more important in limiting viral replication. The early antiviral response and apoptosis correlated with the ability to limit viral replication. Both viruses reduced RIG-I associated antiviral responses and subsequent induction of IFN-β. However it was found that there was constitutive release of IFN-β by BECs and this was critical in inducing late antiviral signaling via type I IFN receptors, and was crucial in limiting viral infection. This study characterizes anti-influenza virus responses in airway epithelial cells and shows that constitutive IFN-β release plays a more important role in initiating protective late IFN-stimulated responses during human influenza infection in bronchial epithelial cells.

  9. Synthetic RNA Controllers for Programming Mammalian Cell Fate and Function

    Science.gov (United States)

    2015-11-04

    Final report for “Synthetic RNA controllers for programming mammalian cell fate and function” Principal Investigator: Christina D. Smolke...SUBTITLE Synthetic RNA controllers for programming mammalian cell fate and function 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER...Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18   2 Synthetic RNA controllers for programming mammalian cell fate and function Task 1

  10. The Function of CD3+CD56+ NKT-Like Cells in HIV-Infected Individuals

    Directory of Open Access Journals (Sweden)

    Yongjun Jiang

    2014-01-01

    Full Text Available CD3+CD56+ NKT-like cells are one of the critical effectors in the immune response to viral infection and tumors, but the functional features of NKT-like cells in HIV infection have been rarely reported. In this study, we observed and described the state of NKT-like cell functions in primary HIV-infected individuals (PHIs, chronic HIV-infected individuals (CHIs, long-term nonprogressors (LTNPs, and HIV-negative controls (NCs. The results showed that the percentage of IFN-γ+CD3+CD56+ NKT-like cells was notably higher in LTNPs compared with CHIs, and the proportion of CD3+CD56+ NKT-like cells with dual function (IFN-γ+CD107a+ NKT-like cells in LTNPs was also much higher than in CHIs. Additionally, the percentages of IFN-γ+CD107a+ NKT-like cells negatively correlated with viral load. Taken together, our data demonstrated that good functions of CD3+CD56+ NKT-like cells in LTNPs likely occurred as a protective mechanism that slows down HIV disease progression.

  11. The function of CD3+CD56+ NKT-like cells in HIV-infected individuals.

    Science.gov (United States)

    Jiang, Yongjun; Cui, Xiaojian; Cui, Chen; Zhang, Jian; Zhou, Fangyuan; Zhang, Zining; Fu, Yajing; Xu, Junjie; Chu, Zhenxing; Liu, Jing; Han, Xiaoxu; Liao, Christina; Wang, Yanan; Cao, Yaming; Shang, Hong

    2014-01-01

    CD3(+)CD56(+) NKT-like cells are one of the critical effectors in the immune response to viral infection and tumors, but the functional features of NKT-like cells in HIV infection have been rarely reported. In this study, we observed and described the state of NKT-like cell functions in primary HIV-infected individuals (PHIs), chronic HIV-infected individuals (CHIs), long-term nonprogressors (LTNPs), and HIV-negative controls (NCs). The results showed that the percentage of IFN-γ(+)CD3(+)CD56(+) NKT-like cells was notably higher in LTNPs compared with CHIs, and the proportion of CD3(+)CD56(+) NKT-like cells with dual function (IFN-γ(+)CD107a(+) NKT-like cells) in LTNPs was also much higher than in CHIs. Additionally, the percentages of IFN-γ(+)CD107a(+) NKT-like cells negatively correlated with viral load. Taken together, our data demonstrated that good functions of CD3(+)CD56(+) NKT-like cells in LTNPs likely occurred as a protective mechanism that slows down HIV disease progression.

  12. Mechanical regulation of T-cell functions

    OpenAIRE

    Chen, Wei; Zhu, Cheng

    2013-01-01

    T cells are key players of the mammalian adaptive immune system. They experience different mechanical microenvironments during their life cycles, from the thymus, secondary lymph organs, and peripheral tissues that are free of externally applied force but display variable substrate rigidities, to the blood and lymphatic circulation systems where complicated hydrodynamic forces are present. Regardless of whether T cells are subject to external forces or generate their own internal forces, they...

  13. Effects of Delayed Enteral Nutrition on Inflammatory Responses and Immune Function Competence in Critically Ill Patients with Prolonged Fasting.

    Science.gov (United States)

    Xi, Fengchan; Li, Ning; Geng, Yanxia; Gao, Tao; Zhang, Juanjuan; Jun, Tanshan; Lin, Zhiliang; Li, Weiqin; Zhu, Weiming; Yu, Wenkui; Li, Jieshou

    2014-05-01

    Although different studies suggest that early enteral nutrition (EEN) has benefits in reducing infectious complications, there is no data that addresses whether delayed enteral nutrition (EN) is detrimental and if it may have effects on inflammatory responses and immune function. Forty-five critically ill patients with long fasting were randomly allocated in two groups according to the type of nutritional support. The first group included patients assuming a standard enteral nutrition (EN, n = 22) and the second group assuming a parenteral nutrition (PN, n = 23). The daily nutritional amount was 25 kcal (105 kJ)/kg for all patients. The inflammatory markers white blood cells (WBC), C-reactive protein (CRP), TNF-α, IL-1-β, IL-6, IL-4, IL- 10 and the immune T-lymphocyte sub-populations CD3+, CD4+, CD8+, and HLA-DR+ were evaluated at day 1, and after 2, 3 and 7 days. IL-4, IL-10, CD3+, CD4+, CD8+ and the CD4+/CD8+ ratio were not statistically different between the two groups. WBC and TNF-α in EN patients were higher than those in PN after 3 and 7 days (P fasting increased systemic inflammatory responses, whereas EN could modify immune function, therefore reducing hospital stay and costs.

  14. Correlations and functional connections in a population of grid cells

    OpenAIRE

    Dunn, Benjamin; Mørreaunet, Maria; Roudi, Yasser

    2014-01-01

    We study the statistics of spike trains of simultaneously recorded grid cells in freely behaving rats. We evaluate pairwise correlations between these cells and, using a maximum entropy kinetic pairwise model (kinetic Ising model), study their functional connectivity. Even when we account for the covariations in firing rates due to overlapping fields, both the pairwise correlations and functional connections decay as a function of the shortest distance between the vertices of the spatial firi...

  15. Criticality safety study of the MSRE Fuel Drain Tank Cell in Building 7503

    Energy Technology Data Exchange (ETDEWEB)

    Hollenbach, D.F.; Hopper, C.M.

    1994-01-01

    This report provides a criticality safety study of the molten salt reactor fuel currently being stored in the Fuel Drain Tank (FDT) Cell of the Molten Salt Reactor Experiment (MSRE) facility (Building 7503) located in the Melton Valley area of the Oak Ridge National Laboratory. The FDTs contain approximately 36 kg of uranium consisting primarily of {sup 233}U, some plutonium, and fission products in a solidified fluoride salt mixture. The nominal composition of the fluoride salt mixture in the FDTs is 42.16 wt % LiF, 35.79 wt % BeF{sub 2}, 21.01 wt % ZrF{sub 4}, 1.02 wt % UF{sub 4}, and 0.02 wt % PuF{sub 3}. The historic criticality safety study does not meet current standards. This work is in support of a new nuclear criticality safety analysis and approval update. Questions concerning the degree of subcriticality associated with the material in its current state and in its most reactive credible upset condition are addressed. The safety study consists of two parts. In the first part, the FDT Cell was modeled using KENO V.a and analyzed using a variety of cross-section sets. The base FDT Cell model was then modified to represent the most reactive credible upset conditions and analyzed. The second part consists of establishing a benchmark for the FDT Cell. Because of the lack of any other relevant benchmark experiments, the original MSRE was also modeled in KENO V.a and analyzed. The results of the reactor model were then compared with documented MSRE reactor conditions. The analysis shows that even under the most reactive credible upset conditions, the MSRE FDT Cell is significantly subcritical.

  16. Natural killer cells in obesity: impaired function and increased susceptibility to the effects of cigarette smoke.

    LENUS (Irish Health Repository)

    O'Shea, Donal

    2012-02-01

    BACKGROUND: Obese individuals who smoke have a 14 year reduction in life expectancy. Both obesity and smoking are independently associated with increased risk of malignancy. Natural killer cells (NK) are critical mediators of anti-tumour immunity and are compromised in obese patients and smokers. We examined whether NK cell function was differentially affected by cigarette smoke in obese and lean subjects. METHODOLOGY AND PRINCIPAL FINDINGS: Clinical data and blood were collected from 40 severely obese subjects (BMI>40 kg\\/m(2)) and 20 lean healthy subjects. NK cell levels and function were assessed using flow cytometry and cytotoxicity assays. The effect of cigarette smoke on NK cell ability to kill K562 tumour cells was assessed in the presence or absence of the adipokines leptin and adiponectin. NK cell levels were significantly decreased in obese subjects compared to lean controls (7.6 vs 16.6%, p = 0.0008). NK function was also significantly compromised in obese patients (30% +\\/- 13% vs 42% +\\/-12%, p = 0.04). Cigarette smoke inhibited NK cell ability to kill tumour cell lines (p<0.0001). NK cells from obese subjects were even more susceptible to the inhibitory effects of smoke compared to lean subjects (33% vs 28%, p = 0.01). Cigarette smoke prevented NK cell activation, as well as perforin and interferon-gamma secretion upon tumour challenge. Adiponectin but not leptin partially reversed the effects of smoke on NK cell function in both obese (p = 0.002) and lean controls (p = 0.01). CONCLUSIONS\\/SIGNIFICANCE: Obese subjects have impaired NK cell activity that is more susceptible to the detrimental effects of cigarette smoke compared to lean subjects. This may play a role in the increase of cancer and infection seen in this population. Adiponectin is capable of restoring NK cell activity and may have therapeutic potential for immunity in obese subjects and smokers.

  17. Natural killer cells in obesity: impaired function and increased susceptibility to the effects of cigarette smoke.

    LENUS (Irish Health Repository)

    O'Shea, Donal

    2010-01-01

    BACKGROUND: Obese individuals who smoke have a 14 year reduction in life expectancy. Both obesity and smoking are independently associated with increased risk of malignancy. Natural killer cells (NK) are critical mediators of anti-tumour immunity and are compromised in obese patients and smokers. We examined whether NK cell function was differentially affected by cigarette smoke in obese and lean subjects. METHODOLOGY AND PRINCIPAL FINDINGS: Clinical data and blood were collected from 40 severely obese subjects (BMI>40 kg\\/m(2)) and 20 lean healthy subjects. NK cell levels and function were assessed using flow cytometry and cytotoxicity assays. The effect of cigarette smoke on NK cell ability to kill K562 tumour cells was assessed in the presence or absence of the adipokines leptin and adiponectin. NK cell levels were significantly decreased in obese subjects compared to lean controls (7.6 vs 16.6%, p = 0.0008). NK function was also significantly compromised in obese patients (30% +\\/- 13% vs 42% +\\/-12%, p = 0.04). Cigarette smoke inhibited NK cell ability to kill tumour cell lines (p<0.0001). NK cells from obese subjects were even more susceptible to the inhibitory effects of smoke compared to lean subjects (33% vs 28%, p = 0.01). Cigarette smoke prevented NK cell activation, as well as perforin and interferon-gamma secretion upon tumour challenge. Adiponectin but not leptin partially reversed the effects of smoke on NK cell function in both obese (p = 0.002) and lean controls (p = 0.01). CONCLUSIONS\\/SIGNIFICANCE: Obese subjects have impaired NK cell activity that is more susceptible to the detrimental effects of cigarette smoke compared to lean subjects. This may play a role in the increase of cancer and infection seen in this population. Adiponectin is capable of restoring NK cell activity and may have therapeutic potential for immunity in obese subjects and smokers.

  18. Natural killer cells in obesity: impaired function and increased susceptibility to the effects of cigarette smoke.

    Directory of Open Access Journals (Sweden)

    Donal O'Shea

    Full Text Available BACKGROUND: Obese individuals who smoke have a 14 year reduction in life expectancy. Both obesity and smoking are independently associated with increased risk of malignancy. Natural killer cells (NK are critical mediators of anti-tumour immunity and are compromised in obese patients and smokers. We examined whether NK cell function was differentially affected by cigarette smoke in obese and lean subjects. METHODOLOGY AND PRINCIPAL FINDINGS: Clinical data and blood were collected from 40 severely obese subjects (BMI>40 kg/m(2 and 20 lean healthy subjects. NK cell levels and function were assessed using flow cytometry and cytotoxicity assays. The effect of cigarette smoke on NK cell ability to kill K562 tumour cells was assessed in the presence or absence of the adipokines leptin and adiponectin. NK cell levels were significantly decreased in obese subjects compared to lean controls (7.6 vs 16.6%, p = 0.0008. NK function was also significantly compromised in obese patients (30% +/- 13% vs 42% +/-12%, p = 0.04. Cigarette smoke inhibited NK cell ability to kill tumour cell lines (p<0.0001. NK cells from obese subjects were even more susceptible to the inhibitory effects of smoke compared to lean subjects (33% vs 28%, p = 0.01. Cigarette smoke prevented NK cell activation, as well as perforin and interferon-gamma secretion upon tumour challenge. Adiponectin but not leptin partially reversed the effects of smoke on NK cell function in both obese (p = 0.002 and lean controls (p = 0.01. CONCLUSIONS/SIGNIFICANCE: Obese subjects have impaired NK cell activity that is more susceptible to the detrimental effects of cigarette smoke compared to lean subjects. This may play a role in the increase of cancer and infection seen in this population. Adiponectin is capable of restoring NK cell activity and may have therapeutic potential for immunity in obese subjects and smokers.

  19. Ex vivo cytosolic delivery of functional macromolecules to immune cells.

    Directory of Open Access Journals (Sweden)

    Armon Sharei

    Full Text Available Intracellular delivery of biomolecules, such as proteins and siRNAs, into primary immune cells, especially resting lymphocytes, is a challenge. Here we describe the design and testing of microfluidic intracellular delivery systems that cause temporary membrane disruption by rapid mechanical deformation of human and mouse immune cells. Dextran, antibody and siRNA delivery performance is measured in multiple immune cell types and the approach's potential to engineer cell function is demonstrated in HIV infection studies.

  20. Intra-arterial Autologous Bone Marrow Cell Transplantation in a Patient with Upper-extremity Critical Limb Ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Madaric, Juraj, E-mail: jurmad@hotmail.com [National Institute of Cardiovascular Diseases (NUSCH) and Slovak Medical University, Department of Cardiology and Angiology (Slovakia); Klepanec, Andrej [National Institute of Cardiovascular Diseases, Department of Diagnostic and Interventional Radiology (Slovakia); Mistrik, Martin [Clinic of Hematology and Transfusiology, Faculty Hospital (Slovakia); Altaner, Cestmir [Slovak Academy of Science, Institute of Experimental Oncology (Slovakia); Vulev, Ivan [National Institute of Cardiovascular Diseases, Department of Diagnostic and Interventional Radiology (Slovakia)

    2013-04-15

    Induction of therapeutic angiogenesis by autologous bone marrow mononuclear cell transplantation has been identified as a potential new option in patients with advanced lower-limb ischemia. There is little evidence of the benefit of intra-arterial cell application in upper-limb critical ischemia. We describe a patient with upper-extremity critical limb ischemia with digital gangrene resulting from hypothenar hammer syndrome successfully treated by intra-arterial autologous bone marrow mononuclear cell transplantation.

  1. Functional Imaging of the Foot with Perfusion Angiography in Critical Limb Ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Reekers, Jim A., E-mail: j.a.reekers@amc.uva.nl [AMC, Dept of Radiology (Netherlands); Koelemay, Mark J. W., E-mail: m.j.koelemaij@amc.uva.nl [AMC, Dept of Vascular Surgery (Netherlands); Marquering, Henk A., E-mail: h.a.marquering@amc.uva.nl; Bavel, Ed T. van, E-mail: e.vanbavel@amc.uva.n [AMC, Dept of Biomedical Engineering and Physics (Netherlands)

    2016-02-15

    PurposeTo report on the first clinical experience with perfusion angiography (PA) of the foot in patients with chronic critical limb ischemia.Materials and MethodsPA is a post-processing software algorithm and no extra digital subtraction angiography (DSA) has to be performed for this analysis. The data used to test the feasibility of PA were obtained from a consecutive group of 89 patients with CLI who were treated with standard below the knee angioplasty and 12 separate patients who were not suitable for endovascular revascularization.ResultsMotion artifacts in the dataset of the DSA made post-procedural analysis impossible in 10 % intervention. In the majority of patients (59/68) PA showed an increase in volume flow in the foot after successful angioplasty of the crural vessels. However, in 9/68 patients no increase was seen after successful angioplasty. With the use of a local administered competitive α-adrenergic receptor antagonist, it is also possible to test and quantify the capillary resistance index which is a parameter for the remaining functionality of the microcirculation in CLI patients.ConclusionPA might be used as a new endpoint for lower limb revascularization and can also be used to test the functionality the microcirculation to identify sub-types of patients with CLI. Clinical evaluation and standardization of PA is mandatory before introduction in daily practice.

  2. Sturmian functions in a L2 basis: Critical nuclear charge for N-electron atoms

    International Nuclear Information System (INIS)

    Frapiccini, A.L.; Gasaneo, G.; Colavecchia, F.D.; Mitnik, D.

    2007-01-01

    Two particle Sturmian functions [M. Rotenberg, Ann. Phys., NY 19 (1962) 262; S.V. Khristenko, Theor. Math. Fiz. 22 (1975) 31 (Engl. Transl. Theor. Math. Phys. 22, 21)] for a short range potentials are obtained by expanding the solution of the Schroedinger equation in a finite L 2 Laguerre-type basis. These functions are chosen to satisfy certain boundary conditions, such as regularity at the origin and the correct asymptotic behavior according to the energy domain: exponential decay for negative energy and outgoing (incoming or standing wave) for positive energy. The set of eigenvalues obtained is discrete for both positive and negative energies. This Sturmian basis is used to solve the Schroedinger equation for a one-particle model potential [A.V. Sergeev, S. Kais, J. Quant. Chem. 75 (1999) 533] to describe the motion of a loosely bound electron in a multielectron atom. Values of the two parameters of the potential are computed to represent the Helium isoelectronic series and the critical nuclear charge Z c is found, in good agreement with previous calculations

  3. Propionyl-L-carnitine improves endothelial function, microcirculation and pain management in critical limb ischemia.

    Science.gov (United States)

    De Marchi, S; Zecchetto, S; Rigoni, A; Prior, M; Fondrieschi, L; Scuro, A; Rulfo, F; Arosio, E

    2012-10-01

    Chronic critical limb ischemia (CLI) is a severe condition of hypo-perfusion of lower limbs, which is associated with inflammation and a pro-coagulative state. It is a disease at high risk of amputation and cardiovascular death. Propionyl-L-carnitine (PLC) is efficacious in improving pain free walking distance in peripheral arterial disease with claudication; it also exerts favorable effects on the arterial wall and on endothelial function. The purpose of this study was to evaluate the effects of PLC on microcirculation, endothelial function and pain relief in patients affected by CLI not suitable for surgical intervention. We enrolled 48 patients with CLI. Patients were randomized into two groups: the first group was treated with PLC, the second was treated with saline solution. All of them underwent the following tests: laser Doppler flowmetry at the forefoot at rest and after ischemia, trans cutaneous oxygen partial pressure and carbon dioxide partial pressure at the forefoot at rest and after ischemia, endothelium dependent dilation of the brachial artery. All tests were repeated after treatments. Pain was assessed by visual analog pain scale. Endothelium dependent dilation increased after PLC (9.5 ± 3.2 vs 4.9 ± 1.4 %; p production decreased after PLC. VAS showed a significant reduction in pain perception after active treatment. In CLI patients, PLC can improve microcirculation (post ischemic hyperemia, TcPO2 and TcPCO2 production). PLC also enhances endothelium dependent dilation and reduces analgesic consumption and pain perception.

  4. HSI for monitoring the critical safety functions status tree of a NPP

    International Nuclear Information System (INIS)

    Oliveira, Mauro Vitor de; Almeida, Jose Carlos Soares de; Augusto, Silas Cordeiro; Jaime, Guilherme Dutra Gonzaga

    2013-01-01

    Critical safety function (CSF) is the most significant design concept for prioritize operator actions based on the potential threat to the three barriers (fuel cladding, primary coolant system boundary, and containment) and allows the operator to respond to these threats prior to event diagnosis. CSF has a hierarchical information structure that organizes the system variables affecting the plant safety in terms of goal-means relations. It is important that the operator should be aware of various success paths associated with each CSF in order to respond to unanticipated system failures quickly. When an emergency occurs in NPPs, the operator should monitor CSFs periodically and identify possible success paths as necessary, and try to stabilize or safely shut down the plant using emergency operating procedure (EOP) that includes steps to check the CSFs. This implies that safety function status check may become a cognitively burdensome task that needs to be supported by proper information display. The advanced human-system interface (HSI) in nuclear power plants provides an information environment that supports the operators' burdensome cognitive tasks. This paper describes a CSFs interface design for supporting the operator's tasks to monitor and identify the associated success path for Westinghouse 3-loops NPP. (author)

  5. Age of red blood cells and mortality in the critically ill

    LENUS (Irish Health Repository)

    Pettila, Ville

    2011-04-15

    Abstract Introduction In critically ill patients, it is uncertain whether exposure to older red blood cells (RBCs) may contribute to mortality. We therefore aimed to evaluate the association between the age of RBCs and outcome in a large unselected cohort of critically ill patients in Australia and New Zealand. We hypothesized that exposure to even a single unit of older RBCs may be associated with an increased risk of death. Methods We conducted a prospective, multicenter observational study in 47 ICUs during a 5-week period between August 2008 and September 2008. We included 757 critically ill adult patients receiving at least one unit of RBCs. To test our hypothesis we compared hospital mortality according to quartiles of exposure to maximum age of RBCs without and with adjustment for possible confounding factors. Results Compared with other quartiles (mean maximum red cell age 22.7 days; mortality 121\\/568 (21.3%)), patients treated with exposure to the lowest quartile of oldest RBCs (mean maximum red cell age 7.7 days; hospital mortality 25\\/189 (13.2%)) had an unadjusted absolute risk reduction in hospital mortality of 8.1% (95% confidence interval = 2.2 to 14.0%). After adjustment for Acute Physiology and Chronic Health Evaluation III score, other blood component transfusions, number of RBC transfusions, pretransfusion hemoglobin concentration, and cardiac surgery, the odds ratio for hospital mortality for patients exposed to the older three quartiles compared with the lowest quartile was 2.01 (95% confidence interval = 1.07 to 3.77). Conclusions In critically ill patients, in Australia and New Zealand, exposure to older RBCs is independently associated with an increased risk of death.

  6. Membrane phosphorylation and nerve cell function

    International Nuclear Information System (INIS)

    Baer, P.R.

    1982-01-01

    This thesis deals with the phosphorylation of membrane components. In part I a series of experiments is described using the hippocampal slice as a model system. In part II a different model system - cultured hybrid cells - is used to study protein and lipid phosphorylation, influenced by incubation with neuropeptides. In part III in vivo and in vitro studies are combined to study protein phosphorylation after neuroanatomical lesions. In a section of part II (Page 81-90) labelling experiments of the membrane inositol-phospholipids are described. 32 P-ATP was used to label phospholipids in intact hybrid cells, and short incubations were found to be the most favourable. (C.F.)

  7. Macrophages and Mitochondria: A Critical Interplay Between Metabolism, Signaling, and the Functional Activity.

    Science.gov (United States)

    Tur, J; Vico, T; Lloberas, J; Zorzano, A; Celada, A

    2017-01-01

    Macrophages are phagocytic cells that participate in a broad range of cellular functions and they are key regulators of innate immune responses and inflammation. Mitochondria are highly dynamic endosymbiotic organelles that play key roles in cellular metabolism and apoptosis. Mounting evidence suggests that mitochondria are involved in the interplay between metabolism and innate immune responses. The ability of these organelles to alter the metabolic profile of a cell, thereby allowing an appropriate response to each situation, is crucial for the correct establishment of immune responses. Furthermore, mitochondria act as scaffolds for many proteins involved in immune signaling pathways and as such they are able to modulate the function of these proteins. Finally, mitochondria release molecules, such as reactive oxygen species, which directly regulate the immune response. In summary, mitochondria can be considered as core components in the regulation of innate immune signaling. Here we discuss the intricate relationship between mitochondria, metabolism, intracellular signaling, and innate immune responses in macrophages. © 2017 Elsevier Inc. All rights reserved.

  8. Interleukin 35 Rescues Regulatory B Cell Function, but the Effect Is Dysregulated in Ulcerative Colitis.

    Science.gov (United States)

    Wang, Shaoxuan; Qin, Chengyong

    2017-05-01

    Ulcerative colitis (UC) is a long-time inflammatory condition arising from aberrant immune activation in the colon and the rectum. Interleukin (IL)-35 plays critical roles in autoimmune disorders. In this study, we explored the pathways of IL-35 in affecting UC. First, peripheral blood mononuclear cells (PBMCs) from UC patients were obtained. Pretreating PBMCs with IL-35 resulted in significantly elevated IL-10 production from whole PBMCs as well as B cells, whereas pretreating PBMCs with IL-12 or IL-27 did not demonstrate a similar effect. IL-35 suppressed the proliferation of CD4 + CD25 - conventional T cells, CD4 + CD25 + regulatory T (Treg) cells, and CD8 + T cells, but did not inhibit the proliferation of B cells. IL-35-mediated IL-10 secretion in B cells did not require the presence of Treg cells. After treatment with IL-35, B cells from UC patients presented significantly enhanced regulatory function, characterized by inhibiting cell proliferation and interferon (IFN)-γ, IL-17, and tumor necrosis factor (TNF)-α secretion from autologous CD4 + CD25 - T cells and CD8 + T cells, which was dependent on IL-10 signaling. However, IL-35-treatment did not demonstrate an effect on regulating IL-5 and IL-13 responses. These discoveries identified a Th1, Th17, and CD8 + T cell-targeting role of IL-35 in UC patients. Next, we examined the IL-35 expression in the intestinal mucosal in UC patients. Data showed that both noninflamed and inflamed tissues from UC patients presented significantly lower IL-35 secretion compared to healthy control tissues, which was associated with suppressed p35 transcription. UC patients with higher IL-35 also presented higher IL-10 secretion in gut mucosa. Together, our study identified that IL-35 could mediate anti-inflammatory function through promoting regulatory B cell functions, but this effect was suppressed in UC patients.

  9. Skeletal Stem Cells: Origins, Functions and Uncertainties.

    Science.gov (United States)

    Mohamed, Fatma F; Franceschi, Renny T

    2017-12-01

    The development and maintenance of the skeleton requires a steady source of skeletal progenitors to provide the osteoblasts and chondrocytes necessary for bone and cartilage growth and development. The current model for skeletal stem cells (SSCs) posits that SSC/progenitor cells are present in bone marrow (BM) and other osteogenic sites such as cranial sutures where they undergo self-renewal and differentiation to give rise to the main skeletal tissues. SSCs hold great promise for understanding skeletal biology and genetic diseases of bone as well as for the advancement of bone tissue engineering and regenerative medicine strategies. In the past few years, a considerable effort has been devoted to identifying and purifying skeletal stem cells and determining their contribution to bone formation and homeostasis. Here, we review recent progress in this area with particular emphasis on the discovery of specific SSC markers, their use in tracking the progression of cell populations along specific lineages and the regulation of SSCs in both the appendicular and cranial skeleton.

  10. The influence of recovery duration between periods of exercise on the critical power function.

    Science.gov (United States)

    Bishop, D; Jenkins, D G

    1995-01-01

    It has been shown that when three periods of exercise at different intensities are performed to exhaustion, the linear regression of the work accomplished on the time taken defines the critical power (CP) function. The slope of this function is related to endurance ability, whereas the y-intercept is considered to represent anaerobic work capacity (AWC). The purpose of this study was to determine whether two different recovery durations (3 and 24 h), separating three periods of exercise, would elicit differences in the linear CP function. Nine healthy, untrained female students [19.5 (SD 1.6) years] completed five sessions of cycle exercise to exhaustion in random order (familiarisation). Three of these five power outputs were then used in the main part of the study in which the subjects were randomly assigned to two groups. Group one first performed the three power outputs on the same day, with 3 h of passive recovery separating each session (3 on 1). Group two first performed the three power outputs on 3 consecutive days, with approximately 24 h between sessions (3 con). Following 1 day of rest, group one repeated their three power outputs on 3 consecutive days and group two completed their three tests on the same day. Repeated-measures ANOVA revealed no significant differences between the mean values of CP or AWC calculated from the 3 on 1 or 3 con conditions. Trial two estimates of CP were, however, 3.4% (P < 0.05) higher than trial one (familiarisation) estimates. The results of this study showed that reliable measurements of both CP and AWC can be determined from three tests separated by rest periods of 3 h, provided that the subjects are first familiarised with the tests. We found one series of five exercise sessions to be sufficient familiarisation to ensure similar subsequent estimates of CP.

  11. Combined dysfunctions of immune cells predict nosocomial infection in critically ill patients.

    Science.gov (United States)

    Conway Morris, A; Anderson, N; Brittan, M; Wilkinson, T S; McAuley, D F; Antonelli, J; McCulloch, C; Barr, L C; Dhaliwal, K; Jones, R O; Haslett, C; Hay, A W; Swann, D G; Laurenson, I F; Davidson, D J; Rossi, A G; Walsh, T S; Simpson, A J

    2013-11-01

    Nosocomial infection occurs commonly in intensive care units (ICUs). Although critical illness is associated with immune activation, the prevalence of nosocomial infections suggests concomitant immune suppression. This study examined the temporal occurrence of immune dysfunction across three immune cell types, and their relationship with the development of nosocomial infection. A prospective observational cohort study was undertaken in a teaching hospital general ICU. Critically ill patients were recruited and underwent serial examination of immune status, namely percentage regulatory T-cells (Tregs), monocyte deactivation (by expression) and neutrophil dysfunction (by CD88 expression). The occurrence of nosocomial infection was determined using pre-defined, objective criteria. Ninety-six patients were recruited, of whom 95 had data available for analysis. Relative to healthy controls, percentage Tregs were elevated 6-10 days after admission, while monocyte HLA-DR and neutrophil CD88 showed broader depression across time points measured. Thirty-three patients (35%) developed nosocomial infection, and patients developing nosocomial infection showed significantly greater immune dysfunction by the measures used. Tregs and neutrophil dysfunction remained significantly predictive of infection in a Cox hazards model correcting for time effects and clinical confounders {hazard ratio (HR) 2.4 [95% confidence interval (CI) 1.1-5.4] and 6.9 (95% CI 1.6-30), respectively, P=0.001}. Cumulative immune dysfunction resulted in a progressive risk of infection, rising from no cases in patients with no dysfunction to 75% of patients with dysfunction of all three cell types (P=0.0004). Dysfunctions of T-cells, monocytes, and neutrophils predict acquisition of nosocomial infection, and combine additively to stratify risk of nosocomial infection in the critically ill.

  12. Uncovering Factors Related to Pancreatic Beta-Cell Function.

    Science.gov (United States)

    Curran, Aoife M; Ryan, Miriam F; Drummond, Elaine; Gibney, Eileen R; Gibney, Michael J; Roche, Helen M; Brennan, Lorraine

    2016-01-01

    The incidence of type 2 diabetes has increased rapidly on a global scale. Beta-cell dysfunction contributes to the overall pathogenesis of type 2 diabetes. However, factors contributing to beta-cell function are not clear. The aims of this study were (i) to identify factors related to pancreatic beta-cell function and (ii) to perform mechanistic studies in vitro. Three specific measures of beta-cell function were assessed for 110 participants who completed an oral glucose tolerance test as part of the Metabolic Challenge Study. Anthropometric and biochemical parameters were assessed as potential modulators of beta-cell function. Subsequent in vitro experiments were performed using the BRIN-BD11 pancreatic beta-cell line. Validation of findings were performed in a second human cohort. Waist-to-hip ratio was the strongest anthropometric modulator of beta-cell function, with beta-coefficients of -0.33 (p = 0.001) and -0.30 (p = 0.002) for beta-cell function/homeostatic model assessment of insulin resistance (HOMA-IR), and disposition index respectively. Additionally, the resistin-to-adiponectin ratio (RA index) emerged as being strongly associated with beta-cell function, with beta-coefficients of -0.24 (p = 0.038) and -0.25 (p = 0.028) for beta-cell function/HOMA-IR, and disposition index respectively. Similar results were obtained using a third measure for beta-cell function. In vitro experiments revealed that the RA index was a potent regulator of acute insulin secretion where a high RA index (20ng ml-1 resistin, 5nmol l-1 g-adiponectin) significantly decreased insulin secretion whereas a low RA index (10ng ml-1 resistin, 10nmol l-1 g-adiponectin) significantly increased insulin secretion. The RA index was successfully validated in a second human cohort with beta-coefficients of -0.40 (p = 0.006) and -0.38 (p = 0.008) for beta-cell function/ HOMA-IR, and disposition index respectively. Waist-to-hip ratio and RA index were identified as significant modulators of

  13. Uncovering Factors Related to Pancreatic Beta-Cell Function.

    Directory of Open Access Journals (Sweden)

    Aoife M Curran

    Full Text Available The incidence of type 2 diabetes has increased rapidly on a global scale. Beta-cell dysfunction contributes to the overall pathogenesis of type 2 diabetes. However, factors contributing to beta-cell function are not clear. The aims of this study were (i to identify factors related to pancreatic beta-cell function and (ii to perform mechanistic studies in vitro.Three specific measures of beta-cell function were assessed for 110 participants who completed an oral glucose tolerance test as part of the Metabolic Challenge Study. Anthropometric and biochemical parameters were assessed as potential modulators of beta-cell function. Subsequent in vitro experiments were performed using the BRIN-BD11 pancreatic beta-cell line. Validation of findings were performed in a second human cohort.Waist-to-hip ratio was the strongest anthropometric modulator of beta-cell function, with beta-coefficients of -0.33 (p = 0.001 and -0.30 (p = 0.002 for beta-cell function/homeostatic model assessment of insulin resistance (HOMA-IR, and disposition index respectively. Additionally, the resistin-to-adiponectin ratio (RA index emerged as being strongly associated with beta-cell function, with beta-coefficients of -0.24 (p = 0.038 and -0.25 (p = 0.028 for beta-cell function/HOMA-IR, and disposition index respectively. Similar results were obtained using a third measure for beta-cell function. In vitro experiments revealed that the RA index was a potent regulator of acute insulin secretion where a high RA index (20ng ml-1 resistin, 5nmol l-1 g-adiponectin significantly decreased insulin secretion whereas a low RA index (10ng ml-1 resistin, 10nmol l-1 g-adiponectin significantly increased insulin secretion. The RA index was successfully validated in a second human cohort with beta-coefficients of -0.40 (p = 0.006 and -0.38 (p = 0.008 for beta-cell function/ HOMA-IR, and disposition index respectively.Waist-to-hip ratio and RA index were identified as significant modulators

  14. Structure and function of stem cell pools in mammalian cell renewal systems

    International Nuclear Information System (INIS)

    Fliedner, T.M.; Nothdurft, W.

    1979-01-01

    Stem cells play a key-role in the maintenance of the equilibrium between cell loss and cell production in cell renewal systems as well as in the understanding of the radiation pathophysiology of mammalian organisms. The integrity of mammalian organisms with the need to maintain a constant ''millieu interior'' is depending on the normal functioning of cell renewal systems, especially those of epithelial surfaces and blood cell forming organs. All cell renewal systems of bodies have a very similar functional structure consisting of functional, proliferative - amplifying and stem cell compartments. They differ in transit and cell cycle times and in the number of amplification division - aside from the difference in their functional and biochemical make-up. The stem cell pools are providing the cells capable of differentiation without depleting their own kind. This can be achieved by symmetrical or assymmetrical stem cell division. In normal steady state, 50% of the stem cell division remain in the stem cell pool, while the other 50% leave it to differentiate, proliferate and mature, hemopoietic system is distributed throughout bodies. This is an important factor in the radiation biology of mammalian organisms since the loss of function in one area can be compensated for by more production in other areas, and locally depleted sites can be reseeded with the stem cells migrating in from blood. (Yamashita, S.)

  15. Behavior and function of tissue-resident memory T cells.

    Science.gov (United States)

    Ariotti, Silvia; Haanen, John B; Schumacher, Ton N

    2012-01-01

    Our understanding of memory T cell function in mice and men is to date in large part restricted to the behavior of circulating memory T cells. Emerging evidence, however, suggests that in addition to such systemic memory T cell populations, a separate population of locally confined memory T cells is generated at former sites of antigen encounter. Here, we discuss the potential function of these long-term tissue-resident memory T cells (T(TRM)), how such local T cell memory can be maintained for prolonged periods of time, and how the induction of long-term tissue-resident memory T cells may potentially be exploited during vaccination. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Phenotype and functions of memory Tfh cells in human blood.

    Science.gov (United States)

    Schmitt, Nathalie; Bentebibel, Salah-Eddine; Ueno, Hideki

    2014-09-01

    Our understanding of the origin and functions of human blood CXCR5(+) CD4(+) T cells found in human blood has changed dramatically in the past years. These cells are currently considered to represent a circulating memory compartment of T follicular helper (Tfh) lineage cells. Recent studies have shown that blood memory Tfh cells are composed of phenotypically and functionally distinct subsets. Here, we review the current understanding of human blood memory Tfh cells and the subsets within this compartment. We present a strategy to define these subsets based on cell surface profiles. Finally, we discuss how increased understanding of the biology of blood memory Tfh cells may contribute insight into the pathogenesis of autoimmune diseases and the mode of action of vaccines. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Prophylactic Plasma Transfusion Is Not Associated With Decreased Red Blood Cell Requirements in Critically Ill Patients.

    Science.gov (United States)

    Warner, Matthew A; Chandran, Arun; Jenkins, Gregory; Kor, Daryl J

    2017-05-01

    Critically ill patients frequently receive plasma transfusion under the assumptions that abnormal coagulation test results confer increased risk of bleeding and that plasma transfusion will decrease this risk. However, the effect of prophylactic plasma transfusion remains poorly understood. The objective of this study was to determine the relationship between prophylactic plasma transfusion and bleeding complications in critically ill patients. This is a retrospective cohort study of adults admitted to the intensive care unit (ICU) at a single academic institution between January 1, 2009 and December 31, 2013. Inclusion criteria included age ≥18 years and an international normalized ratio measured during ICU admission. Multivariable propensity-matched analyses were used to evaluate associations between prophylactic plasma transfusion and outcomes of interest with a primary outcome of red blood cell transfusion in the ensuing 24 hours and secondary outcomes of hospital- and ICU-free days and mortality within 30 days of ICU discharge. A total of 27,561 patients were included in the investigation with 2472 (9.0%) receiving plasma therapy and 1105 (44.7%) for which plasma transfusion was prophylactic in nature. In multivariable propensity-matched analyses, patients receiving plasma had higher rates of red blood cell transfusion (odds ratio: 4.3 [95% confidence interval: 3.3-5.7], P plasma in the critically ill was not associated with improved clinical outcomes. Further investigation examining the utility of plasma transfusion in this population is warranted.

  18. The function of BAFF on T helper cells in autoimmunity.

    Science.gov (United States)

    Chen, Maogen; Lin, Xiaohong; Liu, Ya; Li, Qiang; Deng, Yiling; Liu, Zhongmin; Brand, David; Guo, Zhiyong; He, Xiaoshun; Ryffel, Bernhard; Zheng, Song Guo

    2014-06-01

    B cell-activating factor belonging to the TNF family (BAFF) exerts its pathogenic role in supporting the survival and proliferation of B cells, regulating class switch recombination as well as the selection of autoreactive B cells. Overexpression of BAFF induces a dramatic expansion of activated B cells, particularly marginal zone B cells, as well as hypergammaglobulinemia, autoantibody production and immune complex deposition. However, in addition to its effect on B cells, recent work has also demonstrated that BAFF can promote T cell activation, proliferation and differentiation. In this review, we have discussed the recent progress on the function and role of BAFF on T cells and T cell-mediated diseases. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. The function of BAFF on T helper cells in autoimmunity

    Science.gov (United States)

    Chen, Maogen; Lin, Xiaohong; Liu, Ya; Li, Qiang; Deng, Yiling; Liu, Zhongmin; Brand, David; Guo, Zhiyong; He, Xiaoshun; Ryffel, Bernhard; Zheng, Song Guo

    2014-01-01

    Summary B cell-activating factor belonging to the TNF family (BAFF) exerts its pathogenic role in supporting the survival and proliferation of B cells, regulating class switch recombination as well as the selection of autoreactive B cells. Overexpression of BAFF induces a dramatic expansion of activated B cells, particularly marginal zone B cells, as well as hypergammaglobulinemia, autoantibody production and immune complex deposition. However, in addition to its effect on B cells, recent work has also demonstrated that BAFF can promote T cell activation, proliferation and differentiation. In this review, we have discussed the recent progress on the function and role of BAFF on T cells and T cell-mediated diseases. PMID:24411564

  20. Critical roles for LIGHT and its receptors in generating T cell-mediated immunity during Leishmania donovani infection.

    Directory of Open Access Journals (Sweden)

    Amanda C Stanley

    2011-10-01

    Full Text Available LIGHT (TNFSF14 is a member of the TNF superfamily involved in inflammation and defence against infection. LIGHT signals via two cell-bound receptors; herpes virus entry mediator (HVEM and lymphotoxin-beta receptor (LTβR. We found that LIGHT is critical for control of hepatic parasite growth in mice with visceral leishmaniasis (VL caused by infection with the protozoan parasite Leishmania donovani. LIGHT-HVEM signalling is essential for early dendritic cell IL-12/IL-23p40 production, and the generation of IFNγ- and TNF-producing T cells that control hepatic infection. However, we also discovered that LIGHT-LTβR interactions suppress anti-parasitic immunity in the liver in the first 7 days of infection by mechanisms that restrict both CD4(+ T cell function and TNF-dependent microbicidal mechanisms. Thus, we have identified distinct roles for LIGHT in infection, and show that manipulation of interactions between LIGHT and its receptors may be used for therapeutic advantage.

  1. Human embryonic stem cells form functional thyroid follicles.

    Science.gov (United States)

    Ma, Risheng; Latif, Rauf; Davies, Terry F

    2015-04-01

    The molecular events that lead to human thyroid cell speciation remain incompletely characterized. It has been shown that overexpression of the regulatory transcription factors Pax8 and Nkx2-1 (ttf-1) directs murine embryonic stem (mES) cells to differentiate into thyroid follicular cells by initiating a transcriptional regulatory network. Such cells subsequently organized into three-dimensional follicular structures in the presence of extracellular matrix. In the current study, human embryonic stem (hES) cells were studied with the aim of recapitulating this scenario and producing functional human thyroid cell lines. Reporter gene tagged pEZ-lentiviral vectors were used to express human PAX8-eGFP and NKX2-1-mCherry in the H9 hES cell line followed by differentiation into thyroid cells directed by Activin A and thyrotropin (TSH). Both transcription factors were expressed efficiently in hES cells expressing either PAX8, NKX2-1, or in combination in the hES cells, which had low endogenous expression of these transcription factors. Further differentiation of the double transfected cells showed the expression of thyroid-specific genes, including thyroglobulin (TG), thyroid peroxidase (TPO), the sodium/iodide symporter (NIS), and the TSH receptor (TSHR) as assessed by reverse transcription polymerase chain reaction and immunostaining. Most notably, the Activin/TSH-induced differentiation approach resulted in thyroid follicle formation and abundant TG protein expression within the follicular lumens. On stimulation with TSH, these hES-derived follicles were also capable of dose-dependent cAMP generation and radioiodine uptake, indicating functional thyroid epithelial cells. The induced expression of PAX8 and NKX2-1 in hES cells was followed by differentiation into thyroid epithelial cells and their commitment to form functional three-dimensional neo-follicular structures. The data provide proof of principal that hES cells can be committed to thyroid cell speciation under

  2. Human diploid MRC-5 cells exhibit several critical properties of human umbilical cord-derived mesenchymal stem cells.

    Science.gov (United States)

    Zhang, Kehua; Na, Tao; Wang, Lin; Gao, Qiang; Yin, Weidong; Wang, Junzhi; Yuan, Bao-Zhu

    2014-11-28

    MRC-5 is the most common human diploid cell line used in production of viral vaccines; mesenchymal stem cells (MSCs) is a type of adult multipotent stem cells. Both cell types share the same fibroblast-like morphology and maintain a normal diploid karyotype over long in vitro expansion. However, other than these similarities, very little is known about MRC-5 in terms of biological properties possessed by MSCs. In this study, we compared MRC-5 with human umbilical cord-derived MSCs (hUC-MSCs), which serves as a representative of human MSCs, in expression of cell surface markers, abilities to differentiate into multiple cell lineages, inhibition of lymphocyte proliferation and promotion of Regulatory T lymphocytes (Treg), and IDO1 expression in response to inflammatory cytokines, all of which are critical properties of MSCs. It was revealed that MRC-5 was almost identical to hUC-MSCs in expression of both positive and negative surface markers of MSCs. Similar to hUC-MSCs, MRC-5 was also able to differentiate into osteocytes and chondrocytes, effectively inhibit mitogen-activated lymphocyte proliferation and promote Tregs, and express IDO1 in response to inflammatory cytokines IFN-γ and TNF-α. In addition, both MRC-5 and hUC-MSCs were non-tumorigenic with an extremely low telomerase activity. Moreover, both cells demonstrated a similar sensitivity to infection by EV71 and rubella viruses, which served as model viruses, in a virus infectivity assay. Therefore, this study suggests that MRC-5 is very likely a previously undefined MSC cell line, thus suggesting the feasibility of developing MSCs of at least umbilical cord origin as new cell substrates to be used in production of viral vaccines. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. TiO{sub 2} nanoparticle-induced ROS correlates with modulated immune cell function

    Energy Technology Data Exchange (ETDEWEB)

    Maurer-Jones, Melissa A.; Christenson, Jenna R.; Haynes, Christy L., E-mail: chaynes@umn.edu [University of Minnesota, Department of Chemistry (United States)

    2012-12-15

    Design of non-toxic nanoparticles will be greatly facilitated by understanding the nanoparticle-cell interaction mechanism on a cell function level. Mast cells are important cells for the immune system's first line of defense, and we can utilize their exocytotic behavior as a model cellular function as it is a conserved process across cell types and species. Perturbations in exocytosis can also have implications for whole organism health. One proposed mode of toxicity is nanoparticle-induced reactive oxygen species (ROS), particularly for titanium dioxide (TiO{sub 2}) nanoparticles. Herein, we have correlated changes in ROS with the perturbation of the critical cell function of exocytosis, using UV light to induce greater levels of ROS in TiO{sub 2} exposed cells. The primary culture mouse peritoneal mast cells (MPMCs) were exposed to varying concentrations of TiO{sub 2} nanoparticles for 24 h. ROS content was determined using 2,7-dihydrodichlorofluorescein diacetate (DCFDA). Cellular viability was determined with the MTT and Trypan blue assays, and exocytosis was measured by the analytical electrochemistry technique of carbon-fiber microelectrode amperometry. MPMCs exposed to TiO{sub 2} nanoparticles experienced a dose-dependent increase in total ROS content. While there was minimal impact of ROS on cellular viability, there is a correlation between ROS amount and exocytosis perturbation. As nanoparticle-induced ROS increases, there is a significant decrease (45 %) in the number of serotonin molecules being released during exocytosis, increase (26 %) in the amount of time for each exocytotic granule to release, and decrease (28 %) in the efficiency of granule trafficking and docking. This is the first evidence that nanoparticle-induced ROS correlates with chemical messenger molecule secretion, possibly making a critical connection between functional impairment and mechanisms contributing to that impairment.

  4. Functional memory B cells and long-lived plasma cells are generated after a single Plasmodium chabaudi infection in mice.

    Directory of Open Access Journals (Sweden)

    Francis Maina Ndungu

    2009-12-01

    Full Text Available Antibodies have long been shown to play a critical role in naturally acquired immunity to malaria, but it has been suggested that Plasmodium-specific antibodies in humans may not be long lived. The cellular mechanisms underlying B cell and antibody responses are difficult to study in human infections; therefore, we have investigated the kinetics, duration and characteristics of the Plasmodium-specific memory B cell response in an infection of P. chabaudi in mice. Memory B cells and plasma cells specific for the C-terminal region of Merozoite Surface Protein 1 were detectable for more than eight months following primary infection. Furthermore, a classical memory response comprised predominantly of the T-cell dependent isotypes IgG2c, IgG2b and IgG1 was elicited upon rechallenge with the homologous parasite, confirming the generation of functional memory B cells. Using cyclophosphamide treatment to discriminate between long-lived and short-lived plasma cells, we demonstrated long-lived cells secreting Plasmodium-specific IgG in both bone marrow and in spleens of infected mice. The presence of these long-lived cells was independent of the presence of chronic infection, as removal of parasites with anti-malarial drugs had no impact on their numbers. Thus, in this model of malaria, both functional Plasmodium-specific memory B cells and long-lived plasma cells can be generated, suggesting that defects in generating these cell populations may not be the reason for generating short-lived antibody responses.

  5. Endocrine disruptors and Leydig cell function.

    Science.gov (United States)

    Svechnikov, K; Izzo, G; Landreh, L; Weisser, J; Söder, O

    2010-01-01

    During the past decades, a large body of information concerning the effects of endocrine disrupting compounds (EDCs) on animals and humans has been accumulated. EDCs are of synthetic or natural origin and certain groups are known to disrupt the action of androgens and to impair the development of the male reproductive tract and external genitalia. The present overview describes the effects of the different classes of EDCs, such as pesticides, phthalates, dioxins, and phytoestrogens, including newly synthesized resveratrol analogs on steroidogenesis in Leydig cells. The potential impact of these compounds on androgen production by Leydig cells during fetal development and in the adult age is discussed. In addition, the possible role of EDCs in connection with the increasing frequency of abnormalities in reproductive development in animals and humans is discussed.

  6. Endocrine Disruptors and Leydig Cell Function

    Directory of Open Access Journals (Sweden)

    K. Svechnikov

    2010-01-01

    Full Text Available During the past decades, a large body of information concerning the effects of endocrine disrupting compounds (EDCs on animals and humans has been accumulated. EDCs are of synthetic or natural origin and certain groups are known to disrupt the action of androgens and to impair the development of the male reproductive tract and external genitalia. The present overview describes the effects of the different classes of EDCs, such as pesticides, phthalates, dioxins, and phytoestrogens, including newly synthesized resveratrol analogs on steroidogenesis in Leydig cells. The potential impact of these compounds on androgen production by Leydig cells during fetal development and in the adult age is discussed. In addition, the possible role of EDCs in connection with the increasing frequency of abnormalities in reproductive development in animals and humans is discussed.

  7. T-cell dysfunction in HIV infection: anergy due to defective antigen-presenting cell function?

    NARCIS (Netherlands)

    Meyaard, L.; Schuitemaker, H.; Miedema, F.

    1993-01-01

    Before CD4+ T cells are depleted, T cells in asymptomatic HIV-infected individuals are functionally abnormal. These T cells are programmed for death, are non-responsive and fail to produce interleukin-2 after antigenic stimulation. Our view is that these different T-cell abnormalities are explained

  8. Osteomacs interact with megakaryocytes and osteoblasts to regulate murine hematopoietic stem cell function.

    Science.gov (United States)

    Mohamad, Safa F; Xu, Linlin; Ghosh, Joydeep; Childress, Paul J; Abeysekera, Irushi; Himes, Evan R; Wu, Hao; Alvarez, Marta B; Davis, Korbin M; Aguilar-Perez, Alexandra; Hong, Jung Min; Bruzzaniti, Angela; Kacena, Melissa A; Srour, Edward F

    2017-12-12

    Networking between hematopoietic stem cells (HSCs) and cells of the hematopoietic niche is critical for stem cell function and maintenance of the stem cell pool. We characterized calvariae-resident osteomacs (OMs) and their interaction with megakaryocytes to sustain HSC function and identified distinguishing properties between OMs and bone marrow (BM)-derived macrophages. OMs, identified as CD45 + F4/80 + cells, were easily detectable (3%-5%) in neonatal calvarial cells. Coculture of neonatal calvarial cells with megakaryocytes for 7 days increased OM three- to sixfold, demonstrating that megakaryocytes regulate OM proliferation. OMs were required for the hematopoiesis-enhancing activity of osteoblasts, and this activity was augmented by megakaryocytes. Serial transplantation demonstrated that HSC repopulating potential was best maintained by in vitro cultures containing osteoblasts, OMs, and megakaryocytes. With or without megakaryocytes, BM-derived macrophages were unable to functionally substitute for neonatal calvarial cell-associated OMs. In addition, OMs differentiated into multinucleated, tartrate resistant acid phosphatase-positive osteoclasts capable of bone resorption. Nine-color flow cytometric analysis revealed that although BM-derived macrophages and OMs share many cell surface phenotypic similarities (CD45, F4/80, CD68, CD11b, Mac2, and Gr-1), only a subgroup of OMs coexpressed M-CSFR and CD166, thus providing a unique profile for OMs. CD169 was expressed by both OMs and BM-derived macrophages and therefore was not a distinguishing marker between these 2 cell types. These results demonstrate that OMs support HSC function and illustrate that megakaryocytes significantly augment the synergistic activity of osteoblasts and OMs. Furthermore, this report establishes for the first time that the crosstalk between OMs, osteoblasts, and megakaryocytes is a novel network supporting HSC function.

  9. Dnd Is a Critical Specifier of Primordial Germ Cells in the Medaka Fish.

    Science.gov (United States)

    Hong, Ni; Li, Mingyou; Yuan, Yongming; Wang, Tiansu; Yi, Meisheng; Xu, Hongyan; Zeng, Huaqiang; Song, Jianxing; Hong, Yunhan

    2016-03-08

    Primordial germ cell (PGC) specification occurs early in development. PGC specifiers have been identified in Drosophila, mouse, and human but remained elusive in most animals. Here we identify the RNA-binding protein Dnd as a critical PGC specifier in the medaka fish (Oryzias latipes). Dnd depletion specifically abolished PGCs, and its overexpression boosted PGCs. We established a single-cell culture procedure enabling lineage tracing in vitro. We show that individual blastomeres from cleavage embryos at the 32- and 64-cell stages are capable of PGC production in culture. Importantly, Dnd overexpression increases PGCs via increasing PGC precursors. Strikingly, dnd RNA forms prominent particles that segregate asymmetrically. Dnd concentrates in germ plasm and stabilizes germ plasm RNA. Therefore, Dnd is a critical specifier of fish PGCs and utilizes particle partition as a previously unidentified mechanism for asymmetric segregation. These findings offer insights into PGC specification and manipulation in medaka as a lower vertebrate model. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Phenotypic and functional plasticity of cells of innate immunity: macrophages, mast cells and neutrophils

    DEFF Research Database (Denmark)

    Galli, Stephen J; Borregaard, Niels; Wynn, Thomas A

    2011-01-01

    ). Here we focus on the occurrence of phenotypically distinct subpopulations in three lineages of myeloid cells with important roles in innate and acquired immunity: macrophages, mast cells and neutrophils. Cytokine signals, epigenetic modifications and other microenvironmental factors can substantially...... and, in some cases, rapidly and reversibly alter the phenotype of these cells and influence their function. This suggests that regulation of the phenotype and function of differentiated hematopoietic cells by microenvironmental factors, including those generated during immune responses, represents...

  11. RNA-seq analysis of sulfur-deprived Chlamydomonas cells reveals aspects of acclimation critical for cell survival.

    Science.gov (United States)

    González-Ballester, David; Casero, David; Cokus, Shawn; Pellegrini, Matteo; Merchant, Sabeeha S; Grossman, Arthur R

    2010-06-01

    The Chlamydomonas reinhardtii transcriptome was characterized from nutrient-replete and sulfur-depleted wild-type and snrk2.1 mutant cells. This mutant is null for the regulatory Ser-Thr kinase SNRK2.1, which is required for acclimation of the alga to sulfur deprivation. The transcriptome analyses used microarray hybridization and RNA-seq technology. Quantitative RT-PCR evaluation of the results obtained by these techniques showed that RNA-seq reports a larger dynamic range of expression levels than do microarray hybridizations. Transcripts responsive to sulfur deprivation included those encoding proteins involved in sulfur acquisition and assimilation, synthesis of sulfur-containing metabolites, Cys degradation, and sulfur recycling. Furthermore, we noted potential modifications of cellular structures during sulfur deprivation, including the cell wall and complexes associated with the photosynthetic apparatus. Moreover, the data suggest that sulfur-deprived cells accumulate proteins with fewer sulfur-containing amino acids. Most of the sulfur deprivation responses are controlled by the SNRK2.1 protein kinase. The snrk2.1 mutant exhibits a set of unique responses during both sulfur-replete and sulfur-depleted conditions that are not observed in wild-type cells; the inability of this mutant to acclimate to S deprivation probably leads to elevated levels of singlet oxygen and severe oxidative stress, which ultimately causes cell death. The transcriptome results for wild-type and mutant cells strongly suggest the occurrence of massive changes in cellular physiology and metabolism as cells become depleted for sulfur and reveal aspects of acclimation that are likely critical for cell survival.

  12. Mesenchymal stem cell-mediated functional tooth regeneration in swine.

    Directory of Open Access Journals (Sweden)

    Wataru Sonoyama

    2006-12-01

    Full Text Available Mesenchymal stem cell-mediated tissue regeneration is a promising approach for regenerative medicine for a wide range of applications. Here we report a new population of stem cells isolated from the root apical papilla of human teeth (SCAP, stem cells from apical papilla. Using a minipig model, we transplanted both human SCAP and periodontal ligament stem cells (PDLSCs to generate a root/periodontal complex capable of supporting a porcelain crown, resulting in normal tooth function. This work integrates a stem cell-mediated tissue regeneration strategy, engineered materials for structure, and current dental crown technologies. This hybridized tissue engineering approach led to recovery of tooth strength and appearance.

  13. Stereotyped high-frequency oscillations discriminate seizure onset zones and critical functional cortex in focal epilepsy.

    Science.gov (United States)

    Liu, Su; Gurses, Candan; Sha, Zhiyi; Quach, Michael M; Sencer, Altay; Bebek, Nerses; Curry, Daniel J; Prabhu, Sujit; Tummala, Sudhakar; Henry, Thomas R; Ince, Nuri F

    2018-01-30

    High-frequency oscillations in local field potentials recorded with intracranial EEG are putative biomarkers of seizure onset zones in epileptic brain. However, localized 80-500 Hz oscillations can also be recorded from normal and non-epileptic cerebral structures. When defined only by rate or frequency, physiological high-frequency oscillations are indistinguishable from pathological ones, which limit their application in epilepsy presurgical planning. We hypothesized that pathological high-frequency oscillations occur in a repetitive fashion with a similar waveform morphology that specifically indicates seizure onset zones. We investigated the waveform patterns of automatically detected high-frequency oscillations in 13 epilepsy patients and five control subjects, with an average of 73 subdural and intracerebral electrodes recorded per patient. The repetitive oscillatory waveforms were identified by using a pipeline of unsupervised machine learning techniques and were then correlated with independently clinician-defined seizure onset zones. Consistently in all patients, the stereotypical high-frequency oscillations with the highest degree of waveform similarity were localized within the seizure onset zones only, whereas the channels generating high-frequency oscillations embedded in random waveforms were found in the functional regions independent from the epileptogenic locations. The repetitive waveform pattern was more evident in fast ripples compared to ripples, suggesting a potential association between waveform repetition and the underlying pathological network. Our findings provided a new tool for the interpretation of pathological high-frequency oscillations that can be efficiently applied to distinguish seizure onset zones from functionally important sites, which is a critical step towards the translation of these signature events into valid clinical biomarkers.awx374media15721572971001. © The Author(s) (2018). Published by Oxford University Press on

  14. Modulation of immune cell functions by the E3 ligase CBL-b

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    Christina eLutz-Nicoladoni

    2015-03-01

    Full Text Available Maintenance of immunological tolerance is a critical hallmark of the immune system. Several signaling checkpoints necessary to balance activating and inhibitory input to immune cells have been described so far, among which the E3 ligase Cbl-b appears to be a central player. Cbl-b is expressed in all leukocyte subsets and regulates several signaling pathways in T cells, NK cells, B cells and different types of myeloid cells. In most cases Cbl-b negatively regulates activation signals through antigen or pattern recognition receptors and co-stimulatory molecules. In line with this function, cblb-deficient immune cells display lower activation thresholds and cblb knockout mice spontaneously develop autoimmunity and are highly susceptible to experimental autoimmunity. Interestingly, genetic association studies link cblb-polymorphisms with autoimmunity also in humans. Vice versa, the increased activation potential of cblb-deficient cells renders them more potent to fight against malignancies or infections. Accordingly, several reports have shown that cblb knockout mice reject tumors, which mainly depends on cytotoxic T and NK cells. Thus targeting Cbl-b may be an interesting strategy to enhance anti-cancer immunity. In this review we summarize the findings on the molecular function of Cbl-b in different cell types and illustrate the potential of Cbl-b as target for immunomodulatory therapies.

  15. Early alterations of red blood cell rheology in critically ill patients.

    Science.gov (United States)

    Reggiori, Giulia; Occhipinti, Giovanna; De Gasperi, Andrea; Vincent, Jean-Louis; Piagnerelli, Michael

    2009-12-01

    To investigate red blood cell rheology in a large intensive care unit population on admission, and to assess the possible influence of comorbidities on the rheology. : Prospective study. Medico-surgical intensive care unit with 31 beds. All intensive care unit admissions during a 5-month period and 20 healthy volunteers. Blood sampling. A total of 196 intensive care patients (160 without and 36 with sepsis) and 20 healthy volunteers were studied. Red blood cell rheology (deformability and aggregation) was assessed ex vivo using the laser-assisted optical rotational cell analyzer (LORCA; Mechatronics Instruments BV, AN Zwaag, Netherlands) within the first 24 hrs after intensive care unit admission. Red blood cell deformability was determined by the elongation index in relation to the shear stress (0.3 to 50 Pa) applied on the red blood cell membrane surface. Aggregation was assessed by the aggregation index. Septic patients were more likely to have anemia, coagulation abnormalities, and comorbidities than were nonseptic patients. Red blood cell deformability was significantly altered in septic compared to nonseptic patients and volunteers for the majority of shear stress rates studied. The aggregation index was greater in septic patients than in volunteers (67.9% [54.7-73.5] vs. 61.8% [58.2-68.4]; p < .05). Only sepsis and hematologic disease influenced the elongation index (both p < .01). Other comorbidities, like cancer, diabetes mellitus, cirrhosis, and terminal renal failure, had no effect on the elongation index. Aggregation index was related to the degree of organ failure (Sequential Organ Failure Assessment score), the red blood cell count, and fibrinogen concentrations. Early alterations of red blood cell rheology are common in intensive care unit patients, especially in those with sepsis. Comorbidities (other than hematologic diseases) do not significantly influence these abnormalities. These alterations could contribute to the microcirculatory alterations

  16. Modeling the critical safety functions status tree of a NPP using FPGA

    International Nuclear Information System (INIS)

    Farias, Marcos Santana; Oliveira, Mauro Vitor de; Jaime, Guilherme Dutra Gonzaga; Almeida, Jose Carlos Soares de; Augusto, Silas Cordeiro

    2013-01-01

    Field Programmable Gate Arrays (FPGAs) based systems and equipment are beginning to appear in new plants I and C applications, as well as in retrofits for operating plants, in particular for safety applications due to their capability to face the systems obsolescence since they are circuit independent. The circuits implemented can be portable to different FPGAs architectures. Moreover, they reduce complexity for regulatory approval as compared to conventional microprocessor-based systems. Critical safety function (CSF) is the most significant design concept for prioritize operator actions for NPP based on the potential threat to the three barriers (fuel cladding, primary coolant system boundary, and containment) and allows the operator to respond to these threats prior to event diagnosis. CSF has a hierarchical information structure that organizes the system variables affecting the plant safety in terms of goal-means relations. This paper describes the application of FPGA in the implementation of the CSFs status tree logic for a Westinghouse 3-loops NPP simulator. (author)

  17. Critical Parameters of the In Vitro Method of Vascular Smooth Muscle Cell Calcification.

    Directory of Open Access Journals (Sweden)

    Luis Hortells

    Full Text Available Vascular calcification (VC is primarily studied using cultures of vascular smooth muscle cells. However, the use of very different protocols and extreme conditions can provide findings unrelated to VC. In this work we aimed to determine the critical experimental parameters that affect calcification in vitro and to determine the relevance to calcification in vivo.Rat VSMC calcification in vitro was studied using different concentrations of fetal calf serum, calcium, and phosphate, in different types of culture media, and using various volumes and rates of change. The bicarbonate content of the media critically affected pH and resulted in supersaturation, depending on the concentration of Ca2+ and Pi. Such supersaturation is a consequence of the high dependence of bicarbonate buffers on CO2 vapor pressure and bicarbonate concentration at pHs above 7.40. Such buffer systems cause considerable pH variations as a result of minor experimental changes. The variations are more critical for DMEM and are negligible when the bicarbonate concentration is reduced to ¼. Particle nucleation and growth were observed by dynamic light scattering and electron microscopy. Using 2mM Pi, particles of ~200nm were observed at 24 hours in MEM and at 1 hour in DMEM. These nuclei grew over time, were deposited in the cells, and caused osteogene expression or cell death, depending on the precipitation rate. TEM observations showed that the initial precipitate was amorphous calcium phosphate (ACP, which converts into hydroxyapatite over time. In blood, the scenario is different, because supersaturation is avoided by a tightly controlled pH of 7.4, which prevents the formation of PO43--containing ACP.The precipitation of ACP in vitro is unrelated to VC in vivo. The model needs to be refined through controlled pH and the use of additional procalcifying agents other than Pi in order to reproduce calcium phosphate deposition in vivo.

  18. Investigating evolutionary conservation of dendritic cell subset identity and functions

    Directory of Open Access Journals (Sweden)

    Thien-Phong eVu Manh

    2015-06-01

    Full Text Available Dendritic cells (DC were initially defined as mononuclear phagocytes with a dendritic morphology and an exquisite efficiency for naïve T cell activation. DC encompass several subsets initially identified by their expression of specific cell surface molecules and later shown to excel in distinct functions and to develop under the instruction of different transcription factors or cytokines. Very few cell surface molecules are expressed in a specific manner on any immune cell type. Hence, to identify cell types, the sole use of a small number of cell surface markers in classical flow cytometry can be deceiving. Moreover, the markers currently used to define mononuclear phagocyte subsets vary depending on the tissue and animal species studied and even between laboratories. This has led to confusion in the definition of DC subset identity and in their attribution of specific functions. There is a strong need to identify a rigorous and consensus way to define mononuclear phagocyte subsets, with precise guidelines potentially applicable throughout tissues and species. We will discuss the advantages, drawbacks and complementarities of different methodologies: cell surface phenotyping, ontogeny, functional characterization and molecular profiling. We will advocate that gene expression profiling is a very rigorous, largely unbiased and accessible method to define the identity of mononuclear phagocyte subsets, which strengthens and refines surface phenotyping. It is uniquely powerful to yield new, experimentally testable, hypotheses on the ontogeny or functions of mononuclear phagocyte subsets, their molecular regulation and their evolutionary conservation. We propose defining cell populations based on a combination of cell surface phenotyping, expression analysis of hallmark genes and robust functional assays, in order to reach a consensus and integrate faster the huge but scattered knowledge accumulated by different laboratories on different cell types

  19. Investigating Evolutionary Conservation of Dendritic Cell Subset Identity and Functions.

    Science.gov (United States)

    Vu Manh, Thien-Phong; Bertho, Nicolas; Hosmalin, Anne; Schwartz-Cornil, Isabelle; Dalod, Marc

    2015-01-01

    Dendritic cells (DCs) were initially defined as mononuclear phagocytes with a dendritic morphology and an exquisite efficiency for naïve T-cell activation. DC encompass several subsets initially identified by their expression of specific cell surface molecules and later shown to excel in distinct functions and to develop under the instruction of different transcription factors or cytokines. Very few cell surface molecules are expressed in a specific manner on any immune cell type. Hence, to identify cell types, the sole use of a small number of cell surface markers in classical flow cytometry can be deceiving. Moreover, the markers currently used to define mononuclear phagocyte subsets vary depending on the tissue and animal species studied and even between laboratories. This has led to confusion in the definition of DC subset identity and in their attribution of specific functions. There is a strong need to identify a rigorous and consensus way to define mononuclear phagocyte subsets, with precise guidelines potentially applicable throughout tissues and species. We will discuss the advantages, drawbacks, and complementarities of different methodologies: cell surface phenotyping, ontogeny, functional characterization, and molecular profiling. We will advocate that gene expression profiling is a very rigorous, largely unbiased and accessible method to define the identity of mononuclear phagocyte subsets, which strengthens and refines surface phenotyping. It is uniquely powerful to yield new, experimentally testable, hypotheses on the ontogeny or functions of mononuclear phagocyte subsets, their molecular regulation, and their evolutionary conservation. We propose defining cell populations based on a combination of cell surface phenotyping, expression analysis of hallmark genes, and robust functional assays, in order to reach a consensus and integrate faster the huge but scattered knowledge accumulated by different laboratories on different cell types, organs, and

  20. Microculture system for studying monolayers of functional beta-cells.

    Science.gov (United States)

    Dobersen, M J; Scharff, J E; Notkins, A L

    1980-04-01

    A method is described for growing monolayers of newborn rat beta-cells in microculture trays. After disruption of the pancreas with collagenase, islets were isolated by Ficoll density gradient centrifugation, trypsinized to obtain individual cells, and plated in 96-well tissue culture trays. The cells were incubated for the first 3 days in growth medium containing 0.1 mM 3-isobutyl-1-methylxanthine to promote monolayer formation. The cultures could be maintained in a functional state, as defined by their responsiveness to known modulators of insulin secretion, for at least 2 weeks. As few as 1 X 10(3) islet cells/well gave results that were reproducible within +/- 10%. It is suggested that the microculture system for islet cells might prove to be a rapid and reproducible screening technique for studying drugs, viruses, or other agents that affect beta-cell function.

  1. Diacylglycerol kinases in T cell tolerance and effector function

    Directory of Open Access Journals (Sweden)

    Shelley S Chen

    2016-11-01

    Full Text Available Diacylglycerol kinases (DGKs are a family of enzymes that regulate the relative levels of diacylglycerol (DAG and phosphatidic acid (PA in cells by phosphorylating DAG to produce PA. Both DAG and PA are important second messengers cascading T cell receptor (TCR signal by recruiting multiple effector molecules such as RasGRP1, PKC, and mTOR. Studies have revealed important physiological functions of DGKs in the regulation of receptor signaling and the development and activation of immune cells. In this review, we will focus on recent progresses in our understanding of two DGK isoforms,  and , in CD8 T effector and memory cell differentiation, regulatory T cell development and function, and invariant NKT cell development and effector lineage differentiation.

  2. Genetic and Epigenetic Mechanisms That Maintain Hematopoietic Stem Cell Function

    Science.gov (United States)

    Kosan, Christian; Godmann, Maren

    2016-01-01

    All hematopoiesis cells develop from multipotent progenitor cells. Hematopoietic stem cells (HSC) have the ability to develop into all blood lineages but also maintain their stemness. Different molecular mechanisms have been identified that are crucial for regulating quiescence and self-renewal to maintain the stem cell pool and for inducing proliferation and lineage differentiation. The stem cell niche provides the microenvironment to keep HSC in a quiescent state. Furthermore, several transcription factors and epigenetic modifiers are involved in this process. These create modifications that regulate the cell fate in a more or less reversible and dynamic way and contribute to HSC homeostasis. In addition, HSC respond in a unique way to DNA damage. These mechanisms also contribute to the regulation of HSC function and are essential to ensure viability after DNA damage. How HSC maintain their quiescent stage during the entire life is still matter of ongoing research. Here we will focus on the molecular mechanisms that regulate HSC function. PMID:26798358

  3. Differential CCR4 Expression And Function in Cutaneous T-Cell Lymphoma Cell Lines

    Directory of Open Access Journals (Sweden)

    Chieh-Shan Wu

    2008-11-01

    Full Text Available Cutaneous T cell lymphoma (CTCL is a clonal epidermotropic malignancy of memory T cells primarily involving the skin. However, the mechanisms governing migration of CTCL cells have not been fully clarified. It has been shown that certain chemokine receptors are upregulated in CTCL cells, but it remains unanswered whether these chemokine receptors play a critical role in the migration dynamics of CTCL. Using cell lines originally derived from patients with different subtypes of CTCL, we have shown higher CCR4 expression in the line derived from the mycosis fungoides (MJ, compared with the line derived from Sézary syndrome (Hut78. In specific responses to CCL22 (a CCR4 ligand treatments, MJ cells showed significant chemotactic migration, enhanced activation and adhesion of certain integrins (CD49d and CD29 in vitro, while the control cells (Hut78, CD4+CD45RO+ memory T cells, and Jurkat cells did not. Furthermore, compared with Hut78 cells, MJ cells manifested significantly more transendothelial migration in responses to treatments with either CCL22 or conditioned medium from dendritic cells in vitro. These results provide further dynamic evidence, in line with the multistep cascade paradigm for leukocyte transendothelial migration, to support a critical role for CCR4 in CTCL migration.

  4. Critical Role for Mast Cell Stat5 Activity in Skin Inflammation

    Directory of Open Access Journals (Sweden)

    Tomoaki Ando

    2014-01-01

    Full Text Available Atopic dermatitis (AD is a chronic inflammatory skin disease. Here, we show that phospholipase C-β3 (PLC-β3-deficient mice spontaneously develop AD-like skin lesions and more severe allergen-induced dermatitis than wild-type mice. Mast cells were required for both AD models and remarkably increased in the skin of Plcb3−/− mice because of the increased Stat5 and reduced SHP-1 activities. Mast cell-specific deletion of Stat5 gene ameliorated allergen-induced dermatitis, whereas that of Shp1 gene encoding Stat5-inactivating SHP-1 exacerbated it. PLC-β3 regulates the expression of periostin in fibroblasts and TSLP in keratinocytes, two proteins critically involved in AD pathogenesis. Furthermore, polymorphisms in PLCB3, SHP1, STAT5A, and STAT5B genes were associated with human AD. Mast cell expression of PLC-β3 was inversely correlated with that of phospho-STAT5, and increased mast cells with high levels of phospho-STAT5 were found in lesional skin of some AD patients. Therefore, STAT5 regulatory mechanisms in mast cells are important for AD pathogenesis.

  5. Review paper: critical issues in tissue engineering: biomaterials, cell sources, angiogenesis, and drug delivery systems.

    Science.gov (United States)

    Naderi, Hojjat; Matin, Maryam M; Bahrami, Ahmad Reza

    2011-11-01

    Tissue engineering is a newly emerging biomedical technology, which aids and increases the repair and regeneration of deficient and injured tissues. It employs the principles from the fields of materials science, cell biology, transplantation, and engineering in an effort to treat or replace damaged tissues. Tissue engineering and development of complex tissues or organs, such as heart, muscle, kidney, liver, and lung, are still a distant milestone in twenty-first century. Generally, there are four main challenges in tissue engineering which need optimization. These include biomaterials, cell sources, vascularization of engineered tissues, and design of drug delivery systems. Biomaterials and cell sources should be specific for the engineering of each tissue or organ. On the other hand, angiogenesis is required not only for the treatment of a variety of ischemic conditions, but it is also a critical component of virtually all tissue-engineering strategies. Therefore, controlling the dose, location, and duration of releasing angiogenic factors via polymeric delivery systems, in order to ultimately better mimic the stem cell niche through scaffolds, will dictate the utility of a variety of biomaterials in tissue regeneration. This review focuses on the use of polymeric vehicles that are made of synthetic and/or natural biomaterials as scaffolds for three-dimensional cell cultures and for locally delivering the inductive growth factors in various formats to provide a method of controlled, localized delivery for the desired time frame and for vascularized tissue-engineering therapies.

  6. Modulation of Conjunctival Goblet Cell Function by Inflammatory Cytokines

    Directory of Open Access Journals (Sweden)

    L. Contreras-Ruiz

    2013-01-01

    Full Text Available Ocular surface inflammation associated with Sjögren’s syndrome is characterized by a loss of secretory function and alteration in numbers of mucin secreting goblet cells. Such changes are a prominent feature of ocular surface inflammatory diseases and are attributed to inflammation; however, the exact effect of the inflammatory cytokines on conjunctival goblet cell function remains largely unknown. In this study, we developed a primary culture of mouse goblet cells from conjunctival tissue and evaluated the effects on their function by inflammatory cytokines detected in the conjunctiva of mouse model of Sjögren’s syndrome (Thrombospondin-1 deficient mice. We found that apoptosis of goblet cells was primarily induced by TNF-α and IFN-γ. These two cytokines also inhibited mucin secretion by goblet cells in response to cholinergic stimulation, whereas IL-6 enhanced such secretion. No changes in secretory response were detected in the presence of IL-13 or IL-17. Goblet cells proliferated to varying degrees in response to all the tested cytokines with the greatest response to IL-13 followed by IL-6. Our results therefore reveal that inflammatory cytokines expressed in the conjunctiva during an ocular surface disease directly disrupt conjunctival goblet cell functions, compromising the protective function of tears, thereby contributing to ocular surface damage.

  7. Critical Correlation Functions for the 4-Dimensional Weakly Self-Avoiding Walk and n-Component {|\\varphi|^4} Model

    Science.gov (United States)

    Slade, Gordon; Tomberg, Alexandre

    2016-03-01

    We extend and apply a rigorous renormalisation group method to study critical correlation functions, on the 4-dimensional lattice Z4, for the weakly coupled n-component {|\\varphi|4} spin model for all {n ≥ 1}, and for the continuous-time weakly self-avoiding walk. For the {|\\varphi|4} model, we prove that the critical two-point function has | x|-2 (Gaussian) decay asymptotically, for {n ≥ 1}. We also determine the asymptotic decay of the critical correlations of the squares of components of {\\varphi}, including the logarithmic corrections to Gaussian scaling, for {n ≥ 1}. The above extends previously known results for n = 1 to all {n ≥ 1}, and also observes new phenomena for n > 1, all with a new method of proof. For the continuous-time weakly self-avoiding walk, we determine the decay of the critical generating function for the "watermelon" network consisting of p weakly mutually- and self-avoiding walks, for all {p ≥ 1}, including the logarithmic corrections. This extends a previously known result for p = 1, for which there is no logarithmic correction, to a much more general setting. In addition, for both models, we study the approach to the critical point and prove the existence of logarithmic corrections to scaling for certain correlation functions. Our method gives a rigorous analysis of the weakly self-avoiding walk as the n = 0 case of the {|\\varphi|4} model, and provides a unified treatment of both models, and of all the above results.

  8. Autophagy is Required for the Maintenance of Liver Progenitor Cell Functionality

    Directory of Open Access Journals (Sweden)

    Yiji Cheng

    2015-06-01

    Full Text Available Background: Liver progenitor cells (LPCs are bipotent stem cells existing in the adult liver, which could be activated upon massive liver injury and contribute to liver regeneration. However, mechanisms of maintenance of LPC functionality remain poorly understood. Previous studies found that autophagy was required for the self-renewal and differentiation of several tissue stem cells. Methods: The study compared the level of autophagic activity in LPCs and differentiated hepatocytes. Then, autophagic activity was inhibited in LPCs by lentivirus-mediated autophagy-related gene 5 or Beclin 1 knockdown. Clonogenic assay, cell viability assays, hepatic differentiation assay, and senescence analysis were conducted to assess the role of autophagy in regulating self-renewal, hepatic differentiation and senescence of LPCs. Results: We observed high autophagic activity in LPCs compared with differentiated hepatocytes. We found that inhibition of autophagy impaired the self-renewal, proliferation, and hepatic differentiation capability of LPCs under normal cultural condition, but had little impact on cell viability. Interestingly, while wild-type LPCs remained rarely affected by the toxin, etoposide, inhibition of autophagy induced the senescent phenotype of LPCs. Overexpression of Beclin 1 in Beclin 1-knockdown LPCs restored the functionality of stem cells. Conclusion: Our findings indicate that autophagy may function as a critical regulator of LPC functionality under both physiological and pathological condition.

  9. Cell-State Transitions Regulated by SLUG Are Critical for Tissue Regeneration and Tumor Initiation

    Directory of Open Access Journals (Sweden)

    Sarah Phillips

    2014-05-01

    Full Text Available Perturbations in stem cell activity and differentiation can lead to developmental defects and cancer. We use an approach involving a quantitative model of cell-state transitions in vitro to gain insights into how SLUG/SNAI2, a key developmental transcription factor, modulates mammary epithelial stem cell activity and differentiation in vivo. In the absence of SLUG, stem cells fail to transition into basal progenitor cells, while existing basal progenitor cells undergo luminal differentiation; together, these changes result in abnormal mammary architecture and defects in tissue function. Furthermore, we show that in the absence of SLUG, mammary stem cell activity necessary for tissue regeneration and cancer initiation is lost. Mechanistically, SLUG regulates differentiation and cellular plasticity by recruiting the chromatin modifier lysine-specific demethylase 1 (LSD1 to promoters of lineage-specific genes to repress transcription. Together, these results demonstrate that SLUG plays a dual role in repressing luminal epithelial differentiation while unlocking stem cell transitions necessary for tumorigenesis.

  10. Programming cell fate on bio-functionalized silicon.

    Science.gov (United States)

    Premnath, Priyatha; Tan, Bo; Venkatakrishnan, Krishnan

    2015-04-01

    Controlling the growth of cells on the surface of silicon without an additive layer or topographical modification is unexplored. This research article delineates the discovery of unique properties of a bio-functionalized silicon substrate, programmed to repel or control cells, generated by ultrafast femtosecond pulse interaction with silicon. Remarkably, bio-functionalization in any shape or size without change in topology or morphology is observed indicating only sub-surface phase transformations. Material characterization reveals the presence of a unique mixture of phases of SiO2 and Si. Consequently, these variations in phase alter the physicochemical characteristics on the surface of silicon resulting in its bio-functionalization. The culture of mouse embryonic fibroblasts shows unique adhesion characteristics on these bio-functionalized silicon surfaces that include cell controlling, cell trapping, and cell shaping. Furthermore, the directionality of fibroblasts is restrained parallel to bio-functionalized zones as evidenced by changes in cytoskeleton. The controlling of proliferation, migration and adhesion of cells is attributed to unique phase bio-functionalization. This method presents considerable promise in a myriad of applications such as tissue engineering, MEMS, and lab-on-a-chip devices. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Potential of bursa-immigrated hematopoietic precursor cells to differentiate to functional B and T cells

    International Nuclear Information System (INIS)

    Weber, W.T.; Alexander, J.E.

    1978-01-01

    The potential of hematopoietic precursor cells, recently immigrated into the 13- and 14-day-old embryonic bursa, to migrate to the thymus and to differentiate to functional T cells was investigated. Chromosomally marked cell populations obtained from 13- and 14-day-old embryonic bursas were transferred i.v. to 780 R γ-irradiated chick embryos of equivalent age. When appropriate chimeras were examined at 4 to 12 weeks after cell transfer, donor cells were found to proliferate primarily in the bursa. Significant donor cell influx into the thymus was not detected. In correlation with these findings, Con A- and PHA-responsive T cells in thymus and spleen cell cultures of recipients remained of host origin whereas the number of anti-CIg responsive B cells of donor type increased gradually in the spleens of recipients. An initial lag period preceded the accumulation of functional donor B cells in the spleens of recipients, despite the predominant presence of dividing donor cells in the bursa. This suggests that the transferred bursal cell population required substantially longer to mature and emigrate from the bursa as functional B cells than the host cell population remaining in the irradiated bursas at time of cell transfer. The failure to detect significant influx of donor cells into the thymus and their failure to differentiate to functional T cells suggest that the recently bursa-immigrated hematopoietic stem cells of 13- and 14-day-old embryos may not be pluripotential cells, but rather cells already committed to the B cell line of differentiation

  12. Left ventricular systolic function in sickle cell anaemia: an ...

    African Journals Online (AJOL)

    Dennenberg BS, Criner G, Jones R, Spann JF. Car- diac function in sickle cell anaemia. Am J Cardiol 1983;. 51: 1674-1678. 5. Rees AH, Stefadouros MA, Strong WB, et al. Left ven- tricular performance in children with homozygous sickle cell anaemia. Br Heart J 1978; 40: 690-696 PubMed . 6. Balfour IC, Covitz W, Davis H, ...

  13. Expression of functional human C1 inhibitor in COS cells

    NARCIS (Netherlands)

    Eldering, E.; Nuijens, J. H.; Hack, C. E.

    1988-01-01

    Full length human C1 inhibitor cDNA was cloned into a vector suitable for transient expression in COS-1 cells. Transfected COS cells secreted an immunoreactive protein of Mr approximately 110,000 that appeared to be functionally equivalent to the plasma-derived protein as established by the

  14. Origin of inner ear hair cells: morphological and functional differentiation from ciliary cells into hair cells in zebrafish inner ear.

    Science.gov (United States)

    Tanimoto, Masashi; Ota, Yukiko; Inoue, Maya; Oda, Yoichi

    2011-03-09

    Auditory and vestibular functions in vertebrates depend on the transduction of sound vibration or head acceleration into electrical responses in inner ear hair cells. Mechanoelectrical transduction occurs at the tip of stereocilia, which are polarized to form an orientational arrangement that determines directional sensitivity. It remains to be clarified when and how premature hair cells acquire their specialized structure and function in living animals. The developmental origin of inner ear hair cells has been studied in vivo in zebrafish embryos. Tether cells, a small number of ciliated cells associated with an "ear stone" (or otolith) in the embryonic zebrafish inner ear, are believed to be precocious hair cells. However, whether or not tether cells acquire hair bundles and mechanosensitivity remains unknown. In the present study, we investigated the morphological and functional development of tether cells. Immunohistochemical examination revealed that stereocilia appeared on the tether cell apex in a polarized arrangement at 22 h postfertilization (hpf). Labeling with FM1-43, a marker of functional mechanotransduction channels, and the in vivo electrophysiological recording of mechanotransducer responses in the developing inner ear demonstrated that tether cells acquired direction-selective mechanosensitivity at 23 hpf. These results revealed that tether cells begin to function as hair cells within an hour after the appearance of a polarized array of stereociliary bundles. Thus, the ciliary cells morphologically and functionally differentiate into the first sensory hair cells in the inner ear of the zebrafish.

  15. Human neural progenitors express functional lysophospholipid receptors that regulate cell growth and morphology

    Directory of Open Access Journals (Sweden)

    Callihan Phillip

    2008-12-01

    Full Text Available Abstract Background Lysophospholipids regulate the morphology and growth of neurons, neural cell lines, and neural progenitors. A stable human neural progenitor cell line is not currently available in which to study the role of lysophospholipids in human neural development. We recently established a stable, adherent human embryonic stem cell-derived neuroepithelial (hES-NEP cell line which recapitulates morphological and phenotypic features of neural progenitor cells isolated from fetal tissue. The goal of this study was to determine if hES-NEP cells express functional lysophospholipid receptors, and if activation of these receptors mediates cellular responses critical for neural development. Results Our results demonstrate that Lysophosphatidic Acid (LPA and Sphingosine-1-phosphate (S1P receptors are functionally expressed in hES-NEP cells and are coupled to multiple cellular signaling pathways. We have shown that transcript levels for S1P1 receptor increased significantly in the transition from embryonic stem cell to hES-NEP. hES-NEP cells express LPA and S1P receptors coupled to Gi/o G-proteins that inhibit adenylyl cyclase and to Gq-like phospholipase C activity. LPA and S1P also induce p44/42 ERK MAP kinase phosphorylation in these cells and stimulate cell proliferation via Gi/o coupled receptors in an Epidermal Growth Factor Receptor (EGFR- and ERK-dependent pathway. In contrast, LPA and S1P stimulate transient cell rounding and aggregation that is independent of EGFR and ERK, but dependent on the Rho effector p160 ROCK. Conclusion Thus, lysophospholipids regulate neural progenitor growth and morphology through distinct mechanisms. These findings establish human ES cell-derived NEP cells as a model system for studying the role of lysophospholipids in neural progenitors.

  16. HIV Latency Reversing Agents have diverse effects on Natural Killer Cell Function

    Directory of Open Access Journals (Sweden)

    Carolina Garrido

    2016-09-01

    Full Text Available In an effort to clear persistent HIV infection, and achieve a durable therapy-free remission of HIV disease, extensive pre-clinical studies and early pilot clinical trials are underway to develop and test agents that can reverse latent HIV infection and present viral antigen to the immune system for clearance. It is therefore critical to understand the impact of latency reversing agents (LRAs on the function of immune effectors needed to clear infected cells. We assessed the impact of LRAs on the function of natural killer (NK cells, the main effector cells of the innate immune system. We studied the effects of three histone deacetylase inhibitors (SAHA or vorinostat, romidepsin and panobinostat and two protein kinase C (PKC agonists (prostratin and ingenol on the antiviral activity, cytotoxicity, cytokine secretion, phenotype and viability of primary NK cells. We found that ex vivo exposure to vorinostat had minimal impact on all parameters assessed, while panobinostat caused a decrease in NK cell viability, antiviral activity and cytotoxicity. Prostratin caused NK cell activation and interestingly, improved antiviral activity. Overall, we found that LRAs can alter the function and fate of NK cells, and these effects must be carefully considered as strategies are developed to clear persistent HIV infection.

  17. Human embryonic stem cells differentiate into functional renal proximal tubular-like cells.

    Science.gov (United States)

    Narayanan, Karthikeyan; Schumacher, Karl M; Tasnim, Farah; Kandasamy, Karthikeyan; Schumacher, Annegret; Ni, Ming; Gao, Shujun; Gopalan, Began; Zink, Daniele; Ying, Jackie Y

    2013-04-01

    Renal cells are used in basic research, disease models, tissue engineering, drug screening, and in vitro toxicology. In order to provide a reliable source of human renal cells, we developed a protocol for the differentiation of human embryonic stem cells into renal epithelial cells. The differentiated stem cells expressed markers characteristic of renal proximal tubular cells and their precursors, whereas markers of other renal cell types were not expressed or expressed at low levels. Marker expression patterns of these differentiated stem cells and in vitro cultivated primary human renal proximal tubular cells were comparable. The differentiated stem cells showed morphological and functional characteristics of renal proximal tubular cells, and generated tubular structures in vitro and in vivo. In addition, the differentiated stem cells contributed in organ cultures for the formation of simple epithelia in the kidney cortex. Bioreactor experiments showed that these cells retained their functional characteristics under conditions as applied in bioartificial kidneys. Thus, our results show that human embryonic stem cells can differentiate into renal proximal tubular-like cells. Our approach would provide a source for human renal proximal tubular cells that are not affected by problems associated with immortalized cell lines or primary cells.

  18. Cellular Allometry of Mitochondrial Functionality Establishes the Optimal Cell Size.

    Science.gov (United States)

    Miettinen, Teemu P; Björklund, Mikael

    2016-11-07

    Eukaryotic cells attempt to maintain an optimal size, resulting in size homeostasis. While cellular content scales isometrically with cell size, allometric laws indicate that metabolism per mass unit should decline with increasing size. Here we use elutriation and single-cell flow cytometry to analyze mitochondrial scaling with cell size. While mitochondrial content increases linearly, mitochondrial membrane potential and oxidative phosphorylation are highest at intermediate cell sizes. Thus, mitochondrial content and functional scaling are uncoupled. The nonlinearity of mitochondrial functionality is cell size, not cell cycle, dependent, and it results in an optimal cell size whereby cellular fitness and proliferative capacity are maximized. While optimal cell size is controlled by growth factor signaling, its establishment and maintenance requires mitochondrial dynamics, which can be controlled by the mevalonate pathway. Thus, optimization of cellular fitness and functionality through mitochondria can explain the requirement for size control, as well as provide means for its maintenance. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Polymer and Composite Membranes for Proton-Conducting, High-Temperature Fuel Cells: A Critical Review.

    Science.gov (United States)

    Quartarone, Eliana; Angioni, Simone; Mustarelli, Piercarlo

    2017-06-22

    Polymer fuel cells operating above 100 °C (High Temperature Polymer Electrolyte Membrane Fuel Cells, HT-PEMFCs) have gained large interest for their application to automobiles. The HT-PEMFC devices are typically made of membranes with poly(benzimidazoles), although other polymers, such as sulphonated poly(ether ether ketones) and pyridine-based materials have been reported. In this critical review, we address the state-of-the-art of membrane fabrication and their properties. A large number of papers of uneven quality has appeared in the literature during the last few years, so this review is limited to works that are judged as significant. Emphasis is put on proton transport and the physico-chemical mechanisms of proton conductivity.

  20. Do Dental X-Rays Induce Genotoxicity and Cytotoxicity in Oral Mucosa Cells? A Critical Review.

    Science.gov (United States)

    Angelieri, Fernanda; Yujra, Veronica Quispe; Oshima, Celina Tizuko Fujiyama; Ribeiro, Daniel Araki

    2017-10-01

    Dental X-rays are widely used in clinical practice, since the technique is an important approach for diagnosing diseases in dental and periodontal tissues. However, it is widely known that radiation is capable of causing damage to cellular systems, such as genotoxicity or cytotoxicity. Thus, the aim of this review was to present a critical analysis regarding the studies published on genotoxicity and cytotoxicity induced by dental X-rays in oral mucosa cells. Such studies have revealed that some oral cell types are more sensitive than others following exposure to dental X-rays. Certainly, this review will contribute to a better understanding of this matter as well as to highlighting perspectives for further studies. Ultimately, such data will promote better safety for both patients and dental professionals. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  1. Expression of NK cell and monocyte receptors in critically ill patients - potential biomarkers of sepsis

    DEFF Research Database (Denmark)

    Kjaergaard, A G; Nielsen, Jeppe Sylvest; Tønnesen, Else

    2015-01-01

    UNLABELLED: Sepsis is characterized by activation of both the innate and adaptive immune systems as a response to infection. During sepsis, the expression of surface receptors expressed on immune competent cells, such as NKG2D and NKp30 on NK cells and TLR4 and CD14 on monocytes, is partly...... regulated by pro- and anti-inflammatory mediators. In this observational study, we aimed to explore whether the expression of these receptors could be used as diagnostic and/or prognostic biomarkers in sepsis. Patients with severe sepsis or septic shock (n = 21) were compared with critically ill non...... were higher in the septic patients compared with the non-septic patients (P sepsis...

  2. Identification of genes encoding critical factors regulating B-cell terminal differentiation in torafugu (Takifugu rubripes).

    Science.gov (United States)

    Ohtani, Maki; Miyadai, Toshiaki; Hiroishi, Shingo

    2006-03-01

    Many transcription factors, and associated co-factors, are involved in the regulation of B-cell terminal differentiation in mammals. In the teleost and cartilaginous fish, although evidence has strongly suggested the existence of B-cell like lymphocytes, the mechanism of terminal differentiation of B-cells remains to be elucidated. In the present study, we searched for the nucleotide and amino acid sequences similar to the critical regulatory factors facilitating the terminal differentiation of B-cells using the fugu BLAST server. We cloned the following cDNAs from Takifugu rubripes: (1) B-lymphocyte-induced maturation protein-1 (Blimp-1), which plays a major role in promoting plasma cell differentiation by repressing the transcription of many genes that participate in maintaining the differentiation of mature B-cells; (2) Bcl-6, which facilitates germinal center formation and represses Blimp-1 expression; (3) X-box binding protein-1 (XBP-1), which operates Ig secretion by activating transcription of the ER-stress responsible genes; (4) Pax-5, which suppresses XBP-1 and enhances the expression of activation-induced cytidine deaminase (AID), an inducer of somatic hypermutation and class-switch recombination of the immunoglobulin gene; and (5) TLE-3, one of the Groucho family proteins, a co-factor for Blimp-1. We also identified other co-factors and many target genes of Blimp-1 by in silico and/or cDNA cloning. These finding indicates that the basal process of B-cell terminal differentiation in fish is controlled by factors identical to those in mammals.

  3. Salivary gland NK cells are phenotypically and functionally unique.

    Directory of Open Access Journals (Sweden)

    Marlowe S Tessmer

    2011-01-01

    Full Text Available Natural killer (NK cells and CD8(+ T cells play vital roles in containing and eliminating systemic cytomegalovirus (CMV. However, CMV has a tropism for the salivary gland acinar epithelial cells and persists in this organ for several weeks after primary infection. Here we characterize a distinct NK cell population that resides in the salivary gland, uncommon to any described to date, expressing both mature and immature NK cell markers. Using RORγt reporter mice and nude mice, we also show that the salivary gland NK cells are not lymphoid tissue inducer NK-like cells and are not thymic derived. During the course of murine cytomegalovirus (MCMV infection, we found that salivary gland NK cells detect the infection and acquire activation markers, but have limited capacity to produce IFN-γ and degranulate. Salivary gland NK cell effector functions are not regulated by iNKT or T(reg cells, which are mostly absent in the salivary gland. Additionally, we demonstrate that peripheral NK cells are not recruited to this organ even after the systemic infection has been controlled. Altogether, these results indicate that viral persistence and latency in the salivary glands may be due in part to the presence of unfit NK cells and the lack of recruitment of peripheral NK cells.

  4. Roquin Paralogs Differentially Regulate Functional NKT Cell Subsets.

    Science.gov (United States)

    Drees, Christoph; Vahl, J Christoph; Bortoluzzi, Sabrina; Heger, Klaus D; Fischer, Julius C; Wunderlich, F Thomas; Peschel, Christian; Schmidt-Supprian, Marc

    2017-04-01

    NKT cells represent a small subset of glycolipid-recognizing T cells that are heavily implicated in human allergic, autoimmune, and malignant diseases. In the thymus, precursor cells recognize self-glycolipids by virtue of their semi-invariant TCR, which triggers NKT cell lineage commitment and maturation. During their development, NKT cells are polarized into the NKT1, NKT2, and NKT17 subsets, defined through their cytokine-secretion patterns and the expression of key transcription factors. However, we have largely ignored how the differentiation into the NKT cell subsets is regulated. In this article, we describe the mRNA-binding Roquin-1 and -2 proteins as central regulators of murine NKT cell fate decisions. In the thymus, T cell-specific ablation of the Roquin paralogs leads to a dramatic expansion of NKT17 cells, whereas peripheral mature NKT cells are essentially absent. Roquin-1/2-deficient NKT17 cells show exaggerated lineage-specific expression of nearly all NKT17-defining proteins tested. We show through mixed bone marrow chimera experiments that NKT17 polarization is mediated through cell-intrinsic mechanisms early during NKT cell development. In contrast, the loss of peripheral NKT cells is due to cell-extrinsic factors. Surprisingly, Roquin paralog-deficient NKT cells are, in striking contrast to conventional T cells, compromised in their ability to secrete cytokines. Altogether, we show that Roquin paralogs regulate the development and function of NKT cell subsets in the thymus and periphery. Copyright © 2017 by The American Association of Immunologists, Inc.

  5. Pancreatic islet-cell viability, functionality and oxidative status ...

    Indian Academy of Sciences (India)

    Unknown

    lar) in case of lean and obese mice (Dalpe-Scott et al. 1983). Antibiotics also show concentration dependant effect on the islet functionality. Injection of tetracycline hydrochloride at the dose of 25 mg/kg body weight in mice did not change the functional activity of the β-cells and the rate of insulin formation and secretion for ...

  6. Activation of the Aryl Hydrocarbon Receptor during Different Critical Windows in Pregnancy Alters Mammary Epithelial Cell Proliferation and Differentiation

    Science.gov (United States)

    Lew, Betina J.; Collins, Loretta L.; O'Reilly, Michael A.; Lawrence, B. Paige

    2009-01-01

    Exposure to the aryl hydrocarbon receptor (AhR) agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during pregnancy causes severe defects in mammary gland development and function; however, the underlying mechanism remains unclear. Alterations in epithelial cell proliferation, differentiation, and apoptosis during pregnancy-related mammary development can lead to failed lactogenesis. To determine which of these processes are affected and at what time periods, we examined proliferation, differentiation and apoptosis in mammary glands following exposure to TCDD during early, mid or throughout pregnancy. Although AhR activation throughout pregnancy did not cause early involution, there was a 50% decrease in cell proliferation, which was observed as early as the sixth day of pregnancy (DP). TCDD treatment on the day of impregnation only reduced development and proliferation in early and mid-pregnancy, followed by partial recovery by DP17. However, when AhR activation was delayed to DP7, developmental impairment was not observed in mid-pregnancy, but became evident by DP17, whereas proliferation was reduced at all times. Thus, early exposure to TCDD was neither necessary nor sufficient to cause persistent defects in lactogenesis. These varying outcomes in mammary development due to exposure at different times in pregnancy suggest there are critical windows during which AhR activation impairs mammary epithelial cell proliferation and differentiation. PMID:19502548

  7. A high-throughput single-cell analysis of human CD8+ T cell functions reveals discordance for cytokine secretion and cytolysis

    Science.gov (United States)

    Varadarajan, Navin; Julg, Boris; Yamanaka, Yvonne J.; Chen, Huabiao; Ogunniyi, Adebola O.; McAndrew, Elizabeth; Porter, Lindsay C.; Piechocka-Trocha, Alicja; Hill, Brenna J.; Douek, Daniel C.; Pereyra, Florencia; Walker, Bruce D.; Love, J. Christopher

    2011-01-01

    CD8+ T cells are a key component of the adaptive immune response to viral infection. An inadequate CD8+ T cell response is thought to be partly responsible for the persistent chronic infection that arises following infection with HIV. It is therefore critical to identify ways to define what constitutes an adequate or inadequate response. IFN-γ production has been used as a measure of T cell function, but the relationship between cytokine production and the ability of a cell to lyse virus-infected cells is not clear. Moreover, the ability to assess multiple CD8+ T cell functions with single-cell resolution using freshly isolated blood samples, and subsequently to recover these cells for further functional analyses, has not been achieved. As described here, to address this need, we have developed a high-throughput, automated assay in 125-pl microwells to simultaneously evaluate the ability of thousands of individual CD8+ T cells from HIV-infected patients to mediate lysis and to produce cytokines. This concurrent, direct analysis enabled us to investigate the correlation between immediate cytotoxic activity and short-term cytokine secretion. The majority of in vivo primed, circulating HIV-specific CD8+ T cells were discordant for cytolysis and cytokine secretion, notably IFN-γ, when encountering cognate antigen presented on defined numbers of cells. Our approach should facilitate determination of signatures of functional variance among individual effector CD8+ T cells, including those from mucosal samples and those induced by vaccines. PMID:21965332

  8. Caveolae, caveolins, cavins and endothelial cell function: new insights

    Directory of Open Access Journals (Sweden)

    Grzegorz eSowa

    2012-01-01

    Full Text Available Caveolae are cholesterol and glycosphingolipid-rich flask-shaped invaginations of the plasma membrane which are particularly abundant in vascular endothelium and present in all other cell types of the cardiovascular system, including vascular smooth muscle cells, macrophages, cardiac myocytes, and fibroblasts. Caveolins and the more recently discovered cavins are the major protein components of caveolae. When caveolae were discovered, their functional role was believed to be limited to transport across the endothelial cell barrier. Since then, however, a large body of evidence has accumulated, suggesting that these microdomains are very important in regulating many other important endothelial cell functions, mostly due to their ability to concentrate and compartmentalize various signaling molecules. Over the course of several years, multiple studies involving knockout mouse and small interfering RNA approaches have considerably enhanced our understanding of the role of caveolae and caveolin-1 in regulating many cardiovascular functions. New findings have been reported implicating other caveolar protein components in endothelial cell signaling and function, such as the understudied caveolin-2 and newly discovered cavin proteins. The aim of this review is to focus primarily on molecular and cellular aspects of the role of caveolae, caveolins, and cavins in endothelial cell signaling and function. In addition, where appropriate, the possible implications for the cardiovascular and pulmonary physiology and pathophysiology will be discussed.

  9. Critical period of axoglial signaling between neuregulin-1 and brain-derived neurotrophic factor required for early Schwann cell survival and differentiation.

    Science.gov (United States)

    Ma, Zhenzhong; Wang, Jiajing; Song, Fei; Loeb, Jeffrey A

    2011-06-29

    During peripheral nervous system development, successful communication between axons and Schwann cells is required for proper function of both myelinated and nonmyelinated nerve fibers. Alternatively spliced proteins belonging to the neuregulin1 (NRG1) gene family of growth and differentiation factors are essential for Schwann cell survival and peripheral nerve development. Although recent studies have strongly implicated membrane-bound NRG1 forms (type III) in the myelination at late stages, little is known about the role of soluble, heparin-binding forms of NRG1 (type I/II) in regulating early Schwann cell development in vivo. These forms are rapidly released from axons in vitro by Schwann-cell-secreted neurotrophic factors and, unlike membrane-bound forms, have a unique ability to diffuse and adhere to heparan sulfate-rich cell surfaces. Here, we show that axon-derived soluble NRG1 translocates from axonal to Schwann cell surfaces in the embryonic chick between days 5 and 7, corresponding to the critical period of Schwann cell survival. Downregulating endogenous type I/II NRG1 signaling either with a targeted NRG1 antagonist or by shRNA blocks their differentiation from precursors into immature Schwann cells and increases programmed cell death, whereas upregulating NRG1 rescues Schwann cells. Exogenous BDNF also promotes Schwann cell survival through promoting the local release of axonal NRG1. Consistently, increased Schwann cell death occurs both in trkB knock-out mice and after knocking down axonal trkB in chick embryos, which can then be rescued with soluble NRG1. These findings suggest a localized, axoglial feedback loop through soluble NRG1 and BDNF critical for early Schwann cell survival and differentiation.

  10. Expression and function of the endocannabinoid system in glial cells.

    Science.gov (United States)

    Massi, Paola; Valenti, Marta; Bolognini, Daniele; Parolaro, Daniela

    2008-01-01

    In the last few years the role and significance of the glia in CNS function and pathology have been drastically reassessed. Glial cells physiology appears very different in healthy versus pathological brain and the recent identification of cannabinoid receptors and their endogenous ligands in glia has triggered a number of studies exploring the role of (endo)cannabinoid system in glia functionality and disease. (Endo)cannabinoids exert their effects in these cells directly affecting some important peculiar functions of the glia and actively promoting biochemical signals ending in a pro-survival fate for these cells. By contrast, (endo)cannabinoids induce a selective death in glia-derived tumor cells. Of special physiological and therapeutic relevance is the reported ability of glial cells during neuropathological conditions to release an increased amount of endocannabinoids and to overexpress cannabinoid receptors. This evidence has suggested that the endocannabinoids production by glial cells may constitute an endogenous defense mechanism preventing the propagation of neuroinflammation and cell damage. The present paper will review the evidence supporting the regulatory role of (endo)cannabinoids in glia function, holding in consideration their therapeutic potential as neuroprotective and/or anticancer agents.

  11. Nonredundant functions of alphabeta and gammadelta T cells in acrolein-induced pulmonary pathology.

    Science.gov (United States)

    Borchers, Michael T; Wesselkamper, Scott C; Eppert, Bryan L; Motz, Gregory T; Sartor, Maureen A; Tomlinson, Craig R; Medvedovic, Mario; Tichelaar, Jay W

    2008-09-01

    Acrolein exposure represents a significant human health hazard. Repeated acrolein exposure causes the accumulation of monocytes/macrophages and lymphocytes, mucous cell metaplasia, and epithelial injury. Currently, the mechanisms that control these events are unclear, and the relative contribution of T-cell subsets to pulmonary pathologies following repeated exposures to irritants is unknown. To examine whether lymphocyte subpopulations regulate inflammation and epithelial cell pathology, we utilized a mouse model of pulmonary pathology induced by repeated acrolein exposures. The role of lymphocyte subsets was examined by utilizing transgenic mice genetically deficient in either alphabeta T cells or gammadelta T cells, and changes in cellular, molecular, and pathologic outcomes associated with repeated inhalation exposure to 2.0 and 0.5 ppm acrolein were measured. To examine the potential functions of lymphocyte subsets, we purified these cells from the lungs of mice repeatedly exposed to 2.0 ppm acrolein, isolated and amplified messenger RNA, and performed microarray analysis. Our data demonstrate that alphabeta T cells are required for macrophage accumulation, whereas gammadelta T cells are critical regulators of epithelial cell homeostasis, as identified by epithelial cell injury and apoptosis, following repeated acrolein exposure. This is supported by microarray analyses that indicated the T-cell subsets are unique in their gene expression profiles following acrolein exposures. Microarray analyses identified several genes that may contribute to phenotypes mediated by T-cell subpopulations including those involved in cytokine receptor signaling, chemotaxis, growth factor production, lymphocyte activation, and apoptosis. These data provide strong evidence that T-cell subpopulations in the lung are major determinants of pulmonary pathology and highlight the advantages of dissecting their effector functions in response to toxicant exposures.

  12. Body cell mass evaluation in critically ill patients: killing two birds with one stone.

    Science.gov (United States)

    Fiaccadori, Enrico; Morabito, Santo; Cabassi, Aderville; Regolisti, Giuseppe

    2014-05-01

    Body cell mass (BCM) is the metabolically active cell mass involved in O₂ consumption, CO₂ production and energy expenditure. BCM measurement has been suggested as a tool for the evaluation of nutritional status. Since BCM is closely related to energy expenditure, it could also represent a good reference value for the calculation of nutrient needs. In a recent issue of Critical Care, Ismael and colleagues used bioelectrical impedance analysis parameters and anthropometric variables to evaluate BCM in patients with acute kidney injury, before and after a hemodialysis session. The results of this study suggest that BCM is relatively insensitive to major body fluid shifts, a well known factor interfering with nutritional evaluation/monitoring and energy need calculations in the ICU. Thus, BCM seems to be a more 'stable' nutritional variable, as it is apparently less influenced by non-nutritional factors. The results of this paper emphasize the need to identify biologically sound parameters for nutritional status evaluation and energy need calculation in critically ill patients; in this regard, BCM could fulfill these expectations.

  13. Soil processes and functions in critical zone observatories: hypotheses and experimental design

    NARCIS (Netherlands)

    Banwart, S.; Bernasconi, S.M.; Bloem, J.; Blum, W.; Ruiter, de P.C.; Gaans, van P.; Riemsdijk, van W.H.

    2011-01-01

    European Union policy on soil threats and soil protection has prioritized new research to address global soil threats. This research draws on the methodology of Critical Zone Observatories (CZOs) to focus a critical mass of international, multidisciplinary expertise at specific field sites. These

  14. Intracoronary administration of autologous bone marrow-derived progenitor cells in a critically ill two-yr-old child with dilated cardiomyopathy.

    Science.gov (United States)

    Rupp, Stefan; Bauer, Jürgen; Tonn, Torsten; Schächinger, Volker; Dimmeler, Stefanie; Zeiher, Andreas M; Schranz, Dietmar

    2009-08-01

    DCM is the most common cardiomyopathy in childhood. Effectiveness of anticongestive therapy is limited in most cases and about one-third of children diagnosed with DCM die or receive heart transplantation within the first year after diagnosis. Cardiac stem cell transplantation has become a promising therapy to treat heart failure in adult patients. Based on these promising results, the cardiac stem cell therapy might also represent a new therapeutic option particularly in young children. The present case documents for the first time intracoronary administration of autologous bone marrow-derived progenitor cells in a critically ill two-yr-old child with severe heart failure caused by DCM. Because of progressive worsening of the clinical condition despite maximal anticongestive treatment, the decision to perform autologous stem cell therapy was made. Cardiac stem cell therapy proved to be technically feasible, was associated with improvement in cardiac function, and might represent an option before heart transplantation in children with severe heart failure.

  15. Safety and efficacy of cell-based therapy on critical limb ischemia: A meta-analysis.

    Science.gov (United States)

    Ai, Min; Yan, Chang-Fu; Xia, Fu-Chun; Zhou, Shuang-Lu; He, Jian; Li, Cui-Ping

    2016-06-01

    Critical limb ischemia (CLI) is a major health problem worldwide, affecting approximately 500-1000 people per million per annum. Cell-based therapy has given new hope for the treatment of limb ischemia. This study assessed the safety and efficacy of cellular therapy CLI treatment. We searched the PubMed, Embase and Cochrane databases through October 20, 2015, and selected the controlled trials with cell-based therapy for CLI treatment compared with cell-free treatment. We assessed the results by meta-analysis using a variety of outcome measures, as well as the association of mononuclear cell dosage with treatment effect by dose-response meta-analysis. Twenty-five trials were included. For the primary evaluation index, cell-based therapy significantly reduced the rate of major amputation (odds ratio [OR] 0.44, 95% confidence interval [CI] 0.32-0.60, P = 0.000) and significantly increased the rate of amputation-free survival (OR 2.80, 95% CI 1.70-4.61, P = 0.000). Trial sequence analysis indicated that optimal sample size (n = 3374) is needed to detect a plausible treatment effect in all-cause mortality. Cell-based therapy significantly improves ankle brachial index, increases the rate of ulcer healing, increases the transcutaneous pressure of oxygen, reduces limb pain and improves movement ability. Subgroup analysis indicated heterogeneity is caused by type of control, design bias and transplant route. In the dose-response analysis, there was no significant correlation between cell dosage and the therapeutic effect. Cell-based therapy has a significant therapeutic effect on CLI, but randomized double-blind placebo-controlled trials are needed to improve the credibility of this conclusion. Assessment of all-cause mortality also requires a larger sample size to arrive at a strong conclusion. In dose-response analysis, increasing the dosage of cell injections does not significantly improve the therapeutic effects of cell-based therapy. Copyright © 2016

  16. Tumour suppressive function and modulation of programmed cell death 4 (PDCD4 in ovarian cancer.

    Directory of Open Access Journals (Sweden)

    Na Wei

    Full Text Available BACKGROUND: Programmed cell death 4 (PDCD4, originally identified as the neoplastic transformation inhibitor, was attenuated in various cancer types. Our previous study demonstrated a continuous down-regulation of PDCD4 expression in the sequence of normal-borderline-malignant ovarian tissue samples and a significant correlation of PDCD4 expression with disease-free survival. The objective of the current study was to further investigate the function and modulation of PDCD4 in ovarian cancer cells. PRINCIPAL FINDINGS: We demonstrated that ectopic PDCD4 expression significantly inhibited cell proliferation by inducing cell cycle arrest at G(1 stage and up-regulation of cell cycle inhibitors of p27 and p21. Cell migration and invasion were also inhibited by PDCD4. PDCD4 over-expressing cells exhibited elevated phosphatase and tensin homolog (PTEN and inhibited protein kinase B (p-Akt. In addition, the expression of PDCD4 was up-regulated and it was exported to the cytoplasm upon serum withdrawal treatment, but it was rapidly depleted via proteasomal degradation upon serum re-administration. Treatment of a phosphoinositide 3-kinase (PI3K inhibitor prevented the degradation of PDCD4, indicating the involvement of PI3K-Akt pathway in the modulation of PDCD4. CONCLUSION: PDCD4 may play a critical function in arresting cell cycle progression at key checkpoint, thus inhibiting cell proliferation, as well as suppressing tumour metastasis. The PI3K-Akt pathway was implied to be involved in the regulation of PDCD4 degradation in ovarian cancer cells. In response to the stress condition, endogenous PDCD4 was able to shuttle between cell compartments to perform its diverted functions.

  17. Curcumin Modulates Pancreatic Adenocarcinoma Cell-Derived Exosomal Function

    Science.gov (United States)

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

    2015-01-01

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

  18. Mast Cells Are Critical for Protection against Peptic Ulcers Induced by the NSAID Piroxicam

    Science.gov (United States)

    Hampton, Daniel D.; Hale, Laura P.

    2011-01-01

    Many commonly used non-steroidal anti-inflammatory drugs (NSAIDs) also cause gastrointestinal toxicity, including the development of life-threatening peptic ulcers. We report that mast cell-deficient mice have an extremely high incidence of severe peptic ulceration when exposed to the NSAID piroxicam. This enhanced ulcer susceptibility can be reversed by reconstitution with mast cells. Furthermore, wild type mice treated with diphenhydramine hydrochloride, a commonly used antihistamine that blocks histamine H1 receptors, develop a similarly high incidence of peptic ulcers following piroxicam exposure. The protective effect of mast cells is independent of TNF, blockade of H2 receptors, or acid secretion. These data indicate a critical role for mast cells and the histamine that they produce in prevention and/or repair of piroxicam-induced gastric mucosal injury. Additional studies will be required to determine whether this represents a NSAID class effect that can be exploited to develop novel therapeutic strategies to limit the incidence of NSAID-induced side effects in humans. PMID:21858200

  19. Mast cells are critical for protection against peptic ulcers induced by the NSAID piroxicam.

    Directory of Open Access Journals (Sweden)

    Daniel D Hampton

    Full Text Available Many commonly used non-steroidal anti-inflammatory drugs (NSAIDs also cause gastrointestinal toxicity, including the development of life-threatening peptic ulcers. We report that mast cell-deficient mice have an extremely high incidence of severe peptic ulceration when exposed to the NSAID piroxicam. This enhanced ulcer susceptibility can be reversed by reconstitution with mast cells. Furthermore, wild type mice treated with diphenhydramine hydrochloride, a commonly used antihistamine that blocks histamine H1 receptors, develop a similarly high incidence of peptic ulcers following piroxicam exposure. The protective effect of mast cells is independent of TNF, blockade of H2 receptors, or acid secretion. These data indicate a critical role for mast cells and the histamine that they produce in prevention and/or repair of piroxicam-induced gastric mucosal injury. Additional studies will be required to determine whether this represents a NSAID class effect that can be exploited to develop novel therapeutic strategies to limit the incidence of NSAID-induced side effects in humans.

  20. A Fluorescent Probe for Detecting Mycobacterium tuberculosis and Identifying Genes Critical for Cell Entry

    Science.gov (United States)

    Yang, Dong; Ding, Feng; Mitachi, Katsuhiko; Kurosu, Michio; Lee, Richard E.; Kong, Ying

    2016-01-01

    The conventional method for quantitating Mycobacterium tuberculosis (Mtb) in vitro and in vivo relies on bacterial colony forming unit (CFU) enumeration on agar plates. Due to the slow growth rate of Mtb, it takes 3–6 weeks to observe visible colonies on agar plates. Imaging technologies that are capable of quickly quantitating both active and dormant tubercle bacilli in vitro and in vivo would accelerate research toward the development of anti-TB chemotherapies and vaccines. We have developed a fluorescent probe that can directly label the Mtb cell wall components. The fluorescent probe, designated as DLF-1, has a strong affinity to the D-Ala-D-Ala unit of the late peptidoglycan intermediates in the bacterial cell wall. We demonstrate that DLF-1 is capable of detecting Mtb in both the actively replicating and dormant states in vitro at 100 nM without inhibiting bacterial growth. The DLF-1 fluorescence signal correlated well with CFU of the labeled bacteria (R2 = 1 and 0.99 for actively replicating and dormant Mtb, respectively). DLF-1 can also quantitate labeled Mtb inside of cells. The utility of DLF-1 probe to quantitate Mtb was successfully applied to identify genes critical for cell invasion. In conclusion, this novel near infrared imaging probe provides a powerful new tool for enumerating Mtb with potential future use in bacterial virulence study. PMID:28066347

  1. A Fluorescent Probe for Detecting Mycobacterium tuberculosis and Identifying Genes Critical for Cell Entry

    Directory of Open Access Journals (Sweden)

    Dong Yang

    2016-12-01

    Full Text Available ABSTRACTThe conventional method for quantitating Mycobacterium tuberculosis (Mtb in vitro and in vivo relies on bacterial colony forming unit (CFU enumeration on agar plates. Due to the slow growth rate of Mtb, it takes 3-6 weeks to observe visible colonies on agar plates. Imaging technologies that are capable of quickly quantitating both active and dormant tubercle bacilli in vitro and in vivo would accelerate research towards the development of anti-TB chemotherapies and vaccines. We have developed a fluorescent probe that can directly label the Mtb cell wall components. The fluorescent probe, designated as DLF-1, has a strong affinity to the D-Ala-D-Ala unit of the late peptidoglycan intermediates in the bacterial cell wall. We demonstrate that DLF-1 is capable of detecting Mtb in both the active replicating and dormant states in vitro at 100 nM without inhibiting bacterial growth. The DLF-1 fluorescence signal correlated well with CFU of the labeled bacteria (R2=1 and 0.99 for active replicating and dormant Mtb, respectively. DLF-1 can also quantitate labeled Mtb inside of cells. The utility of DLF-1 probe to quantitate Mtb was also successfully applied to identify genes critical for cell invasion. In conclusion, this novel near infrared imaging probe provides a powerful new tool for enumerating Mtb with potential future use in bacterial virulence study.

  2. A dense voltage-mode Josephson memory cell insensitive to systematic variations in critical current density

    International Nuclear Information System (INIS)

    Bradley, P.; Van Duzer, T.

    1985-01-01

    A destructive read-out (DRO) memory cell using three Josephson junctions has been devised whose operation depends only on the ratio of critical currents and application of the proper read/write voltages. The effects of run-to-run and across-thewafer variations in I /SUB c/ are minimized since all three junctions for a given cell are quite close to each other. Additional advantages are: immunity from flux trapping, high circuit density, and fast switching. Since destructive read-out is generally undesirable, a self-rewriting scheme is necessary. Rows and columns of cells with drivers and sense circuits, as well as small memory arrays and decoders have been simulated on SPICE. Power dissipation of cells and bias circuits for a 1K-bit RAM is estimated at about 2 mW. Inclusion of peripheral circuitry raises this by as much as a factor of five depending on the driving scheme and speed desired. Estimated access time is appreciably less than a nanosecond. Preliminary experimental investigations are reported

  3. Functional impacts of ocean acidification in an ecologically critical foundation species.

    Science.gov (United States)

    Gaylord, Brian; Hill, Tessa M; Sanford, Eric; Lenz, Elizabeth A; Jacobs, Lisa A; Sato, Kirk N; Russell, Ann D; Hettinger, Annaliese

    2011-08-01

    Anthropogenic CO(2) is reducing the pH and altering the carbonate chemistry of seawater, with repercussions for marine organisms and ecosystems. Current research suggests that calcification will decrease in many species, but compelling evidence of impaired functional performance of calcium carbonate structures is sparse, particularly in key species. Here we demonstrate that ocean acidification markedly degrades the mechanical integrity of larval shells in the mussel Mytilus californianus, a critical community member on rocky shores throughout the northeastern Pacific. Larvae cultured in seawater containing CO(2) concentrations expected by the year 2100 (540 or 970 ppm) precipitated weaker, thinner and smaller shells than individuals raised under present-day seawater conditions (380 ppm), and also exhibited lower tissue mass. Under a scenario where mussel larvae exposed to different CO(2) levels develop at similar rates, these trends suggest a suite of potential consequences, including an exacerbated vulnerability of new settlers to crushing and drilling attacks by predators; poorer larval condition, causing increased energetic stress during metamorphosis; and greater risks from desiccation at low tide due to shifts in shell area to body mass ratios. Under an alternative scenario where responses derive exclusively from slowed development, with impacted individuals reaching identical milestones in shell strength and size by settlement, a lengthened larval phase could increase exposure to high planktonic mortality rates. In either case, because early life stages operate as population bottlenecks, driving general patterns of distribution and abundance, the ecological success of this vital species may be tied to how ocean acidification proceeds in coming decades.

  4. Criticality of the random field Ising model in and out of equilibrium: A nonperturbative functional renormalization group description

    Science.gov (United States)

    Balog, Ivan; Tarjus, Gilles; Tissier, Matthieu

    2018-03-01

    We show that, contrary to previous suggestions based on computer simulations or erroneous theoretical treatments, the critical points of the random-field Ising model out of equilibrium, when quasistatically changing the applied source at zero temperature, and in equilibrium are not in the same universality class below some critical dimension dD R≈5.1 . We demonstrate this by implementing a nonperturbative functional renormalization group for the associated dynamical field theory. Above dD R, the avalanches, which characterize the evolution of the system at zero temperature, become irrelevant at large distance, and hysteresis and equilibrium critical points are then controlled by the same fixed point. We explain how to use computer simulation and finite-size scaling to check the correspondence between in and out of equilibrium criticality in a far less ambiguous way than done so far.

  5. Casimir amplitudes and capillary condensation of near-critical fluids between parallel plates: renormalized local functional theory.

    Science.gov (United States)

    Okamoto, Ryuichi; Onuki, Akira

    2012-03-21

    We investigate the critical behavior of a near-critical fluid confined between two parallel plates in contact with a reservoir by calculating the order parameter profile and the Casimir amplitudes (for the force density and for the grand potential). Our results are applicable to one-component fluids and binary mixtures. We assume that the walls absorb one of the fluid components selectively for binary mixtures. We propose a renormalized local functional theory accounting for the fluctuation effects. Analysis is performed in the plane of the temperature T and the order parameter in the reservoir ψ(∞). Our theory is universal if the physical quantities are scaled appropriately. If the component favored by the walls is slightly poor in the reservoir, there appears a line of first-order phase transition of capillary condensation outside the bulk coexistence curve. The excess adsorption changes discontinuously between condensed and noncondensed states at the transition. With increasing T, the transition line ends at a capillary critical point T=T(c) (ca) slightly lower than the bulk critical temperature T(c) for the upper critical solution temperature. The Casimir amplitudes are larger than their critical point values by 10-100 times at off-critical compositions near the capillary condensation line. © 2012 American Institute of Physics

  6. Functional and Phenotypic Plasticity of CD4+ T Cell Subsets

    Directory of Open Access Journals (Sweden)

    Tiffany Caza

    2015-01-01

    Full Text Available The remarkable plasticity of CD4+ T cells allows individuals to respond to environmental stimuli in a context-dependent manner. A balance of CD4+ T cell subsets is critical to mount responses against pathogen challenges to prevent inappropriate activation, to maintain tolerance, and to participate in antitumor immune responses. Specification of subsets is a process beginning in intrathymic development and continuing within the circulation. It is highly flexible to adapt to differences in nutrient availability and the tissue microenvironment. CD4+ T cell subsets have significant cross talk, with the ability to “dedifferentiate” given appropriate environmental signals. This ability is dependent on the metabolic status of the cell, with mTOR acting as the rheostat. Autoimmune and antitumor immune responses are regulated by the balance between regulatory T cells and Th17 cells. When a homeostatic balance of subsets is not maintained, immunopathology can result. CD4+ T cells carry complex roles within tumor microenvironments, with context-dependent immune responses influenced by oncogenic drivers and the presence of inflammation. Here, we examine the signals involved in CD4+ T cell specification towards each subset, interconnectedness of cytokine networks, impact of mTOR signaling, and cellular metabolism in lineage specification and provide a supplement describing techniques to study these processes.

  7. Function of bunching segment in multi-cell RF gun

    International Nuclear Information System (INIS)

    Yang Xingfan; Xu Zhou Liu Xisan

    2001-01-01

    With a bunching segment and a shortened first cell, the 4 + 1/2 cell RF gun produced in CAEP has been proved experimentally to be effective in reducing electron back bombardment. The analysis of the electric field distribution and electron motion in bunching segment of multi-cell RF gun is presented. The electron capture efficiency and electron trajectory with different initial phase are calculated using Runge-Kutta method. The function of the bunching segment is discussed. The calculated parameters of the 4 + 1/2 cell RF gun agree well with the experimental results

  8. Physiological and pathophysiological functions of intestinal mast cells.

    Science.gov (United States)

    Bischoff, Stephan C

    2009-07-01

    The normal gastrointestinal (GI) mucosa is equipped with mast cells that account for 2-3% of lamina propria cells under normal conditions. Mast cells are generally associated with allergic disease, and indeed, food allergy that manifests in the GI tract is usually mast cell dependent. On the other hand, mast cells have a number of physiological functions in the GI tract, namely regulatory functions such as control of blood flow and coagulation, smooth muscle contraction and peristalsis, and secretion of acid, electrolytes, and mucus by epithelial cells. One of the most intriguing functions of intestinal mast cells is their role in host defense against microbes like bacteria, viruses, or parasites. Mast cells recognize microbes by antibody-dependent mechanisms and through pattern-recognition receptors. They direct the subsequent immune response by attracting both granulocytes and lymphocytes to the site of challenge via paracrine cytokine release. Moreover, mast cells initiate, by releasing proinflammatory mediators, innate defense mechanisms such as enhanced epithelial secretion, peristalsis, and alarm programs of the enteric nervous This initiation can occur in response to a primary contact to the microbe or other danger signals, but becomes much more effective if the triggering antigen reappears and antibodies of the IgE or IgG type have been generated in the meantime by the specific immune system. Thus, mast cells operate at the interface between innate and adaptive immune responses to enhance the defense against pathogens and, most likely, the commensal flora. In this respect, it is important to note that mast cells are directly involved in controlling the function of the intestinal barrier that turned out to be a crucial site for the development of infectious and immune-mediated diseases. Hence, intestinal mast cells perform regulatory functions to maintain tissue homeostasis, they are involved in host defense mechanisms against pathogens, and they can induce

  9. Heterogeneity of functional properties of Clone 66 murine breast cancer cells expressing various stem cell phenotypes.

    Science.gov (United States)

    Mukhopadhyay, Partha; Farrell, Tracy; Sharma, Gayatri; McGuire, Timothy R; O'Kane, Barbara; Sharp, J Graham

    2013-01-01

    Breast cancer grows, metastasizes and relapses from rare, therapy resistant cells with a stem cell phenotype (cancer stem cells/CSCs). However, there is a lack of studies comparing the functions of CSCs isolated using different phenotypes in order to determine if CSCs are homogeneous or heterogeneous. Cells with various stem cell phenotypes were isolated by sorting from Clone 66 murine breast cancer cells that grow orthotopically in immune intact syngeneic mice. These populations were compared by in vitro functional assays for proliferation, growth, sphere and colony formation; and in vivo limiting dilution analysis of tumorigenesis. The proportion of cells expressing CD44(high)CD24(low/neg), side population (SP) cells, ALDH1(+), CD49f(high), CD133(high), and CD34(high) differed, suggesting heterogeneity. Differences in frequency and size of tumor spheres from these populations were observed. Higher rates of proliferation of non-SP, ALDH1(+), CD34(low), and CD49f(high) suggested properties of transit amplifying cells. Colony formation was higher from ALDH1(-) and non-SP cells than ALDH1(+) and SP cells suggesting a progenitor phenotype. The frequency of clonal colonies that grew in agar varied and was differentially altered by the presence of Matrigel™. In vivo, fewer cells with a stem cell phenotype were needed for tumor formation than "non-stem" cells. Fewer SP cells were needed to form tumors than ALDH1(+) cells suggesting further heterogeneities of cells with stem phenotypes. Different levels of cytokines/chemokines were produced by Clone 66 with RANTES being the highest. Whether the heterogeneity reflects soluble factor production remains to be determined. These data demonstrate that Clone 66 murine breast cancer cells that express stem cell phenotypes are heterogeneous and exhibit different functional properties, and this may also be the case for human breast cancer stem cells.

  10. Cyclic AMP-Responsive Element-Binding Protein (CREB is Critical in Autoimmunity by Promoting Th17 but Inhibiting Treg Cell Differentiation

    Directory of Open Access Journals (Sweden)

    Xiaohu Wang

    2017-11-01

    Full Text Available The molecular mechanisms that govern differential T cell development into pro-inflammatory Th17 vs. regulatory T (Treg cells remain unclear. Here, we show that selective deletion of CREB in T cells or Th17 cells impaired Th17 cell differentiation in vitro and in vivo, and led to resistance to autoimmune diseases. Mechanistically, CREB, activated by CD3-PKC-ϴ signaling, plays a key role in regulating Th17 cell differentiation, at least in part through directly binding to the Il17-Il17f gene locus. Unexpectedly, although dispensable for FOXP3 expression and for the homeostasis and suppressive function of thymus-derived Treg cells, CREB negatively regulates the survival of TGF-β-induced Treg cells, and deletion of CREB resulted in increased FOXP3+ Treg cells in the intestine and protection in a colitis model. Thus, CREB is critical in autoimmune diseases by promoting Th17 cell and inhibiting de novo Treg cell generation.

  11. The Criticality of Norms to the Functional Imperatives of the Social Action System of College and University Work

    Science.gov (United States)

    Braxton, John M.

    2010-01-01

    In this article, I assert that the work of colleges and universities forms a social action system. I array the critical positions represented in this issue according to the four functional imperatives of social action systems: adaptation, goal attainment, integration, and pattern maintenance. I discuss the role of normative structures for these…

  12. Identification and Ranking of Critical Success Factors of Knowledge Management Using Fuzzy Quality Function Deployment Approach: A Case Study

    Directory of Open Access Journals (Sweden)

    Ali Mohaghar

    2014-02-01

    Based on the information accessible for the researchers, this is one of the first works which evaluates the key factors of successful knowledge management through fuzzy quality function deployment approach. It is expected that the proposed method would represent appropriate tools for enterprises which have decided to implement knowledge management because it prioritizes the critical success factors based on the knowledge management outcomes.

  13. Supporting Critical Literacy in High School English by Using Systemic Functional Linguistics to Analyze Fantasy, Canonical, and Nonfiction Texts

    Science.gov (United States)

    Simmons, Amber M.

    2016-01-01

    While important work has been done on assessing classroom texts and investigating classroom discourse, there is little research on teachers doing systemic functional linguistics (SFL) with students for critical ends, especially in the high school arena. This article discusses how instructional use of SFL analytic resources in subject English…

  14. The Effect of Material Property on the Critical Velocity of Randomly Excited Nonlinear Axially Travelling Functionally Graded Plates

    Directory of Open Access Journals (Sweden)

    M. Abedi

    Full Text Available Abstract In this paper, the critical axial speeds of three types of sigmoid, power law and exponential law functionally graded plates for both isotropic and orthotropic cases are obtained via a completely analytic method. The plates are subjected to lateral white noise excitation and show evidence of large deformations. Due to randomness, the conventional deterministic methods fail and a statistical approach must be selected. Here, the probability density function is evaluated analytically for prescribed plates and used to investigate the critical axial velocity of them. Specifically the effect of in-plane forces, mean value of lateral load and the material property on the critical axial speed are studied and discussed for both isotropic and orthotropic functionally graded plates. Since the governing equation is transformed to a non dimensional format, the results can be used for a wide range of plate dimensions. It is shown that the material heterogeneity palys an essential and significant role in increasing or decreasing the critical speed of both isotropic and orthotropic functionally graded plates.

  15. Snail/Slug-YAP/TAZ complexes cooperatively regulate mesenchymal stem cell function and bone formation.

    Science.gov (United States)

    Tang, Yi; Weiss, Stephen J

    2017-03-04

    Snail and Slug are zinc-finger transcription factors that play key roles in directing the epithelial-mesenchymal transition (EMT) programs associated with normal development as well as disease progression. More recent work suggests that these EMT-associated transcription factors also modulate the function of both embryonic and adult stem cells. Interestingly, YAP and TAZ, the co-transcriptional effectors of the Hippo pathway, likewise play an important role in stem cell self-renewal and lineage commitment. While direct intersections between the Snail/Slug and Hippo pathways have not been described previously, we recently described an unexpected cooperative interaction between Snail/Slug and YAP/TAZ that controls the self-renewal and differentiation properties of bone marrow-derived mesenchymal stem cells (MSCs), a cell population critical to bone development. Additional studies revealed that both Snail and Slug are able to form binary complexes with either YAP or TAZ that, together, control YAP/TAZ transcriptional activity and function throughout mouse development. Given the more recent observations that MSC-like cell populations are found in association throughout the vasculature where they participate in tissue regeneration, fibrosis and cancer, the Snail/Slug-YAP/TAZ axis is well-positioned to regulate global stem cell function in health and disease.

  16. Visceral adipose inflammation in obesity is associated with critical alterations in tregulatory cell numbers.

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    Jeffrey Deiuliis

    2011-01-01

    Full Text Available The development of insulin resistance (IR in mouse models of obesity and type 2 diabetes mellitus (DM is characterized by progressive accumulation of inflammatory macrophages and subpopulations of T cells in the visceral adipose. Regulatory T cells (Tregs may play a critical role in modulating tissue inflammation via their interactions with both adaptive and innate immune mechanisms. We hypothesized that an imbalance in Tregs is a critical determinant of adipose inflammation and investigated the role of Tregs in IR/obesity through coordinated studies in mice and humans.Foxp3-green fluorescent protein (GFP "knock-in" mice were randomized to a high-fat diet intervention for a duration of 12 weeks to induce DIO/IR. Morbidly obese humans without overt type 2 DM (n = 13 and lean controls (n = 7 were recruited prospectively for assessment of visceral adipose inflammation. DIO resulted in increased CD3(+CD4(+, and CD3(+CD8(+ cells in visceral adipose with a striking decrease in visceral adipose Tregs. Treg numbers in visceral adipose inversely correlated with CD11b(+CD11c(+ adipose tissue macrophages (ATMs. Splenic Treg numbers were increased with up-regulation of homing receptors CXCR3 and CCR7 and marker of activation CD44. In-vitro differentiation assays showed an inhibition of Treg differentiation in response to conditioned media from inflammatory macrophages. Human visceral adipose in morbid obesity was characterized by an increase in CD11c(+ ATMs and a decrease in foxp3 expression.Our experiments indicate that obesity in mice and humans results in adipose Treg depletion. These changes appear to occur via reduced local differentiation rather than impaired homing. Our findings implicate a role for Tregs as determinants of adipose inflammation.

  17. Altered effector function of peripheral cytotoxic cells in COPD

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    Corne Jonathan M

    2009-06-01

    Full Text Available Abstract Background There is mounting evidence that perforin and granzymes are important mediators in the lung destruction seen in COPD. We investigated the characteristics of the three main perforin and granzyme containing peripheral cells, namely CD8+ T lymphocytes, natural killer (NK; CD56+CD3- cells and NKT-like (CD56+CD3+ cells. Methods Peripheral blood mononuclear cells (PBMCs were isolated and cell numbers and intracellular granzyme B and perforin were analysed by flow cytometry. Immunomagnetically selected CD8+ T lymphocytes, NK (CD56+CD3- and NKT-like (CD56+CD3+ cells were used in an LDH release assay to determine cytotoxicity and cytotoxic mechanisms were investigated by blocking perforin and granzyme B with relevant antibodies. Results The proportion of peripheral blood NKT-like (CD56+CD3+ cells in smokers with COPD (COPD subjects was significantly lower (0.6% than in healthy smokers (smokers (2.8%, p +CD3- cells from COPD subjects were significantly less cytotoxic than in smokers (16.8% vs 51.9% specific lysis, p +CD3+ cells (16.7% vs 52.4% specific lysis, p +CD3- and NKT-like (CD56+CD3+ cells from smokers and HNS. Conclusion In this study, we show that the relative numbers of peripheral blood NK (CD56+CD3- and NKT-like (CD56+CD3+ cells in COPD subjects are reduced and that their cytotoxic effector function is defective.

  18. Novel approaches in function-driven single-cell genomics.

    Science.gov (United States)

    Doud, Devin F R; Woyke, Tanja

    2017-07-01

    Deeper sequencing and improved bioinformatics in conjunction with single-cell and metagenomic approaches continue to illuminate undercharacterized environmental microbial communities. This has propelled the 'who is there, and what might they be doing' paradigm to the uncultivated and has already radically changed the topology of the tree of life and provided key insights into the microbial contribution to biogeochemistry. While characterization of 'who' based on marker genes can describe a large fraction of the community, answering 'what are they doing' remains the elusive pinnacle for microbiology. Function-driven single-cell genomics provides a solution by using a function-based screen to subsample complex microbial communities in a targeted manner for the isolation and genome sequencing of single cells. This enables single-cell sequencing to be focused on cells with specific phenotypic or metabolic characteristics of interest. Recovered genomes are conclusively implicated for both encoding and exhibiting the feature of interest, improving downstream annotation and revealing activity levels within that environment. This emerging approach has already improved our understanding of microbial community functioning and facilitated the experimental analysis of uncharacterized gene product space. Here we provide a comprehensive review of strategies that have been applied for function-driven single-cell genomics and the future directions we envision. © FEMS 2017.

  19. Correlations and functional connections in a population of grid cells.

    Science.gov (United States)

    Dunn, Benjamin; Mørreaunet, Maria; Roudi, Yasser

    2015-02-01

    We study the statistics of spike trains of simultaneously recorded grid cells in freely behaving rats. We evaluate pairwise correlations between these cells and, using a maximum entropy kinetic pairwise model (kinetic Ising model), study their functional connectivity. Even when we account for the covariations in firing rates due to overlapping fields, both the pairwise correlations and functional connections decay as a function of the shortest distance between the vertices of the spatial firing pattern of pairs of grid cells, i.e. their phase difference. They take positive values between cells with nearby phases and approach zero or negative values for larger phase differences. We find similar results also when, in addition to correlations due to overlapping fields, we account for correlations due to theta oscillations and head directional inputs. The inferred connections between neurons in the same module and those from different modules can be both negative and positive, with a mean close to zero, but with the strongest inferred connections found between cells of the same module. Taken together, our results suggest that grid cells in the same module do indeed form a local network of interconnected neurons with a functional connectivity that supports a role for attractor dynamics in the generation of grid pattern.

  20. Cell viability and functionality of probiotic bacteria in dairy products

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    Gabriel eVinderola

    2011-05-01

    Full Text Available Probiotic bacteria, according to the definition adopted by the World Health Organization in 2002, are live microorganisms, which when administered in adequate amounts confer a health benefit to the host. Recent studies show that the same probiotic strain produced and/or preserved under different storage conditions, may present different responses regarding their susceptibility to the adverse conditions of the gastrointestinal tract, its capacity to adhere to the intestinal epithelium, or its immunomodulating capacity, being the functionality affected without changes in cell viability. This could imply that the control of cell viability is not always enough to guarantee the functionality (probiotic capacity of a strain. Therefore, a new challenge arises for food technologists and microbiologists when it comes to designing and monitoring probiotic food: to be able to monitor the cell functionality a probiotic microorganism along all the stages the strain goes through from the moment it is produced and included into the food vehicle until to the moment of consumption. Conventional methodological tools or others still to be developed must be used. The application of cell membrane functionality markers, the use of tests of resistence to intestinal barriers, the study of surface properties and the application of in vivo models comes together as complementary tools to assess the actual capacity of a probiotic into a specific food to exert functional effects regardless the number of viable cells present at the moment of consumption.

  1. Human lung mast cells modulate the functions of airway smooth muscle cells in asthma.

    Science.gov (United States)

    Alkhouri, H; Hollins, F; Moir, L M; Brightling, C E; Armour, C L; Hughes, J M

    2011-09-01

    Activated mast cell densities are increased on the airway smooth muscle in asthma where they may modulate muscle functions and thus contribute to airway inflammation, remodelling and airflow obstruction. To determine the effects of human lung mast cells on the secretory and proliferative functions of airway smooth muscle cells from donors with and without asthma. Freshly isolated human lung mast cells were stimulated with IgE/anti-IgE. Culture supernatants were collected after 2 and 24 h and the mast cells lysed. The supernatants/lysates were added to serum-deprived, subconfluent airway smooth muscle cells for up to 48 h. Released chemokines and extracellular matrix were measured by ELISA, proliferation was quantified by [(3) H]-thymidine incorporation and cell counting, and intracellular signalling by phospho-arrays. Mast cell 2-h supernatants reduced CCL11 and increased CXCL8 and fibronectin production from both asthmatic and nonasthmatic muscle cells. Leupeptin reversed these effects. Mast cell 24-h supernatants and lysates reduced CCL11 release from both muscle cell types but increased CXCL8 release by nonasthmatic cells. The 24-h supernatants also reduced asthmatic, but not nonasthmatic, muscle cell DNA synthesis and asthmatic cell numbers over 5 days through inhibiting extracellular signal-regulated kinase (ERK) and phosphatidylinositol (PI3)-kinase pathways. However, prostaglandins, thromboxanes, IL-4 and IL-13 were not involved in reducing the proliferation. Mast cell proteases and newly synthesized products differentially modulated the secretory and proliferative functions of airway smooth muscle cells from donors with and without asthma. Thus, mast cells may modulate their own recruitment and airway smooth muscle functions locally in asthma. © 2011 John Wiley & Sons A/S.

  2. Integrative modeling of small artery structure and function uncovers critical parameters for diameter regulation.

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    Ed VanBavel

    Full Text Available Organ perfusion is regulated by vasoactivity and structural adaptation of small arteries and arterioles. These resistance vessels are sensitive to pressure, flow and a range of vasoactive stimuli. Several strongly interacting control loops exist. As an example, the myogenic response to a change of pressure influences the endothelial shear stress, thereby altering the contribution of shear-dependent dilation to the vascular tone. In addition, acute responses change the stimulus for structural adaptation and vice versa. Such control loops are able to maintain resistance vessels in a functional and stable state, characterized by regulated wall stress, shear stress, matched active and passive biomechanics and presence of vascular reserve. In this modeling study, four adaptation processes are identified that together with biomechanical properties effectuate such integrated regulation: control of tone, smooth muscle cell length adaptation, eutrophic matrix rearrangement and trophic responses. Their combined action maintains arteries in their optimal state, ready to cope with new challenges, allowing continuous long-term vasoregulation. The exclusion of any of these processes results in a poorly regulated state and in some cases instability of vascular structure.

  3. Evidence implicating the Ras pathway in multiple CD28 costimulatory functions in CD4+ T cells.

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    Sujit V Janardhan

    Full Text Available CD28 costimulation is a critical event in the full activation of CD4(+ T cells that augments cytokine gene transcription, promotes cytokine mRNA stability, prevents induction of anergy, increases cellular metabolism, and increases cell survival. However, despite extensive biochemical analysis of the signaling events downstream of CD28, molecular pathways sufficient to functionally replace the diverse aspects of CD28-mediated costimulation in normal T cells have not been identified. Ras/MAPK signaling is a critical pathway downstream of T cell receptor stimulation, but its role in CD28-mediated costimulation has been controversial. We observed that physiologic CD28 costimulation caused a relocalization of the RasGEF RasGRP to the T cell-APC interface by confocal microscopy. In whole cell biochemical analysis, CD28 cross-linking with either anti-CD28 antibody or B7.1-Ig augmented TCR-induced Ras activation. To determine whether Ras signaling was sufficient to functionally mimic CD28 costimulation, we utilized an adenoviral vector encoding constitutively active H-Ras (61L to transduce normal, Coxsackie-Adenovirus Receptor (CAR transgenic CD4(+ T cells. Like costimulation via CD28, active Ras induced AKT, JNK and ERK phosphorylation. In addition, constitutive Ras signaling mimicked the ability of CD28 to costimulate IL-2 protein secretion, prevent anergy induction, increase glucose uptake, and promote cell survival. Importantly, we also found that active Ras mimicked the mechanism by which CD28 costimulates IL-2 production: by increasing IL-2 gene transcription, and promoting IL-2 mRNA stability. Finally, active Ras was able to induce IL-2 production when combined with ionomycin stimulation in a MEK-1-dependent fashion. Our results are consistent with a central role for Ras signaling in CD28-mediated costimulation.

  4. Functional cell mediated lympholysis I. Description of the assay

    International Nuclear Information System (INIS)

    Goeken, N.E.; Thompson, J.S.

    1981-01-01

    The anamnestic response by human bi-directional (BD) mixed lymphocyte cultures (MLC) to restimulation by cells of the original stimulating type is generally strikingly reduced as compared to that of standard one-way cultures. This difference was shown not to be related to a change in kinetics nor was it due to exhaustion of the media or soluble factors since fresh media did not ameliorate the effect nor were supernatants from BD cultures found to be suppressive. The relative inhibition was also not reversed by removal of the allogeneic cells by phenotype specific antiserum. Cytotoxic tests with donor and responder specific antisera revealed that the cells bearing that phenotype were dramatically reduced in BD as compared to one-way cultures. Thus, the diminished secondary response appears to be due to cytotoxic elimination of the responder cells. This allogeneic cytotoxicity is dependent on non-T, phagocytic, adherent cells. The phenomenon is called Functional Cell Mediated Lympholysis (F-CML). (author)

  5. Isolation and functional aspects of free luteal cells

    International Nuclear Information System (INIS)

    Luborsky, J.L.; Berhrman, H.R.

    1985-01-01

    Methods of luteal cell isolation employ enzymatic treatment of luteal tissue with collagenase and deoxyribonuclease. Additional enzymes such as hyaluronidase or Pronase are also used in some instances. Isolated luteal cells retain the morphological characteristics of steroid secreting cells after isolation. They contain mitochondria, variable amounts of lipid droplets, and an extensive smooth endoplasmic reticulum. Isolated luteal cells have been used in numerous studies to examine the regulation of steriodogenesis by luteinizing hormone (LH). LH receptor binding studies were employed to quantitate specific properties of hormone-receptor interaction in relation to cellular function. Binding of [ 125 I]LH to bovine luteal cells and membranes was compared and it was concluded that the enzymatic treatment used to isolate cells did not change the LH receptor binding kinetics

  6. Overexpression of neurofilament H disrupts normal cell structure and function

    Science.gov (United States)

    Szebenyi, Gyorgyi; Smith, George M.; Li, Ping; Brady, Scott T.

    2002-01-01

    Studying exogenously expressed tagged proteins in live cells has become a standard technique for evaluating protein distribution and function. Typically, expression levels of experimentally introduced proteins are not regulated, and high levels are often preferred to facilitate detection. However, overexpression of many proteins leads to mislocalization and pathologies. Therefore, for normative studies, moderate levels of expression may be more suitable. To understand better the dynamics of intermediate filament formation, transport, and stability in a healthy, living cell, we inserted neurofilament heavy chain (NFH)-green fluorescent protein (GFP) fusion constructs in adenoviral vectors with tetracycline (tet)-regulated promoters. This system allows for turning on or off the synthesis of NFH-GFP at a selected time, for a defined period, in a dose-dependent manner. We used this inducible system for live cell imaging of changes in filament structure and cell shape, motility, and transport associated with increasing NFH-GFP expression. Cells with low to intermediate levels of NFH-GFP were structurally and functionally similar to neighboring, nonexpressing cells. In contrast, overexpression led to pathological alterations in both filament organization and cell function. Copyright 2002 Wiley-Liss, Inc.

  7. Cell therapy with allogenic canine periodontal ligament-derived cells in periodontal regeneration of critical size defects.

    Science.gov (United States)

    Nuñez, Javier; Sanchez, Nerea; Vignoletti, Fabio; Sanz-Martin, Ignacio; Caffesse, Raul; Santamaria, Silvia; Garcia-Sanz, Jose A; Sanz, Mariano

    2017-12-29

    The objective of this in vivo experimental study to evaluate the regenerative potential of a cell therapy combining allogenic periodontal ligament-derived cells within a xenogeneic bone substitute in a similar experimental model. In nine beagle dogs, critical size 6-mm supra-alveolar periodontal defects were created around the PIII and PIV. The resulting supra-alveolar defects were randomly treated with either 1.4 × 10 6 allogenic canine periodontal ligament-derived cells seeded on de-proteinized bovine bone mineral with 10% collagen (DBBM-C) (test group) or DBBM-C without cells (control group). Specimens were obtained at 3 months, and histological outcomes were studied. The histological analysis showed that total furcation closure occurred very seldom in both groups, being the extent of periodontal regeneration located in the apical third of the defect. The calculated amount of periodontal regeneration at the furcation area was comparable in both the test and control groups (1.93 ± 1.14 mm (17%) versus 2.35 ± 1.74 mm (22%), respectively (p = .37). Similarly, there were no significant differences in the amount of new cementum formation 4.49 ± 1.56 mm (41%) versus 4.97 ± 1.05 mm (47%), respectively (p = .45). This experimental study was unable to demonstrate the added value of allogenic cell therapy in supra-crestal periodontal regeneration. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Novel immunomodulatory effects of adiponectin on dendritic cell functions.

    Science.gov (United States)

    Tsang, Julia Yuen Shan; Li, Daxu; Ho, Derek; Peng, Jiao; Xu, Aimin; Lamb, Jonathan; Chen, Yan; Tam, Paul Kwong Hang

    2011-05-01

    Adiponectin (ADN) is an adipocytokine with anti-inflammatory properties. Although it has been reported that ADN can inhibit the immunostimulatory function of monocytes and macrophages, little is known of its effect on dendritic cells (DC). Recent data suggest that ADN can regulate immune responses. DCs are uniquely specialised antigen presenting cells that play a central role in the initiation of immunity and tolerance. In this study, we have investigated the immuno- modulatory effects of ADN on DC functions. We found that ADN has only moderate effect on the differentiation of murine bone marrow (BM) derived DCs but altered the phenotype of DCs. The expression of major histocompatibilty complex class II (MHCII), CD80 and CD86 on ADN conditioned DCs (ADN-DCs) was lower than that on untreated cells. The production of IL-12p40 was also suppressed in ADN-DCs. Interestingly, ADN treated DCs showed an increase in the expression of the inhibitory molecule, programmed death-1 ligand (PDL-1) compared to untreated cells. In vitro co-culture of ADN-DCs with allogeneic T cells led to a decrease in T cell proliferation and reduction of IL-2 production. Concomitant with that, a higher percentage of CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) was detected in co-cultures of T cells and ADN-DCs. Blocking PD-1/PDL-1 pathway could partially restore T cell function. These findings suggest that the immunomodulatory effect of ADN on immune responses could be at least partially be mediated by its ability to alter DC function. The PD-1/PDL-1 pathway and the enhancement of Treg expansion are implicated in the immunomodulatory mechanisms. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. Neuron-NG2 Cell Synapses: Novel Functions for Regulating NG2 Cell Proliferation and Differentiation

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    Qian-Kun Yang

    2013-01-01

    Full Text Available NG2 cells are a population of CNS cells that are distinct from neurons, mature oligodendrocytes, astrocytes, and microglia. These cells can be identified by their NG2 proteoglycan expression. NG2 cells have a highly branched morphology, with abundant processes radiating from the cell body, and express a complex set of voltage-gated channels, AMPA/kainate, and GABA receptors. Neurons notably form classical and nonclassical synapses with NG2 cells, which have varied characteristics and functions. Neuron-NG2 cell synapses could fine-tune NG2 cell activities, including the NG2 cell cycle, differentiation, migration, and myelination, and may be a novel potential therapeutic target for NG2 cell-related diseases, such as hypoxia-ischemia injury and periventricular leukomalacia. Furthermore, neuron-NG2 cell synapses may be correlated with the plasticity of CNS in adulthood with the synaptic contacts passing onto their progenies during proliferation, and synaptic contacts decrease rapidly upon NG2 cell differentiation. In this review, we highlight the characteristics of classical and nonclassical neuron-NG2 cell synapses, the potential functions, and the fate of synaptic contacts during proliferation and differentiation, with the emphasis on the regulation of the NG2 cell cycle by neuron-NG2 cell synapses and their potential underlying mechanisms.

  10. ZFP521 regulates murine hematopoietic stem cell function and facilitates MLL-AF9 leukemogenesis in mouse and human cells.

    Science.gov (United States)

    Garrison, Brian S; Rybak, Adrian P; Beerman, Isabel; Heesters, Balthasar; Mercier, Francois E; Scadden, David T; Bryder, David; Baron, Roland; Rossi, Derrick J

    2017-08-03

    The concept that tumor-initiating cells can co-opt the self-renewal program of endogenous stem cells as a means of enforcing their unlimited proliferative potential is widely accepted, yet identification of specific factors that regulate self-renewal of normal and cancer stem cells remains limited. Using a comparative transcriptomic approach, we identify ZNF521 / Zfp521 as a conserved hematopoietic stem cell (HSC)-enriched transcription factor in human and murine hematopoiesis whose function in HSC biology remains elusive. Competitive serial transplantation assays using Zfp521 -deficient mice revealed that ZFP521 regulates HSC self-renewal and differentiation. In contrast, ectopic expression of ZFP521 in HSCs led to a robust maintenance of progenitor activity in vitro. Transcriptional analysis of human acute myeloid leukemia (AML) patient samples revealed that ZNF521 is highly and specifically upregulated in AMLs with MLL translocations. Using an MLL-AF9 murine leukemia model and serial transplantation studies, we show that ZFP521 is not required for leukemogenesis, although its absence leads to a significant delay in leukemia onset. Furthermore, knockdown of ZNF521 reduced proliferation in human leukemia cell lines possessing MLL-AF9 translocations. Taken together, these results identify ZNF521/ZFP521 as a critical regulator of HSC function, which facilitates MLL-AF9-mediated leukemic disease in mice.

  11. Methylselenol, a selenium metabolite, plays a critical role in inhibiting colon cancer cell growth in vitro and in vivo

    Science.gov (United States)

    Methylselenol is hypothesized to be a critical selenium (Se) metabolite for anticancer activity. In this study, submicromolar methylselenol was generated by incubating methionase with seleno-L methionine, and both colon-cancer-derived HCT-116 cells and noncancerous colon NCM460 cells were exposed to...

  12. A Pivotal Role for Interleukin-27 in CD8+ T Cell Functions and Generation of Cytotoxic T Lymphocytes

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    Noriko Morishima

    2010-01-01

    Full Text Available Cytotoxic T lymphocytes (CTLs play a critical role in the control of various cancers and infections, and therefore the molecular mechanisms of CTL generation are a critical issue in designing antitumor immunotherapy and vaccines which augment the development of functional and long-lasting memory CTLs. Interleukin (IL-27, a member of the IL-6/IL-12 heterodimeric cytokine family, acts on naive CD4+ T cells and plays pivotal roles as a proinflammatory cytokine to promote the early initiation of type-1 helper differentiation and also as an antiinflammatory cytokine to limit the T cell hyperactivity and production of pro-inflammatory cytokines. Recent studies revealed that IL-27 plays an important role in CD8+ T cells as well. Therefore, this article reviews current understanding of the role of IL-27 in CD8+ T cell functions and generation of CTLs.

  13. Functional Proteomics to Identify Moderators of CD8+ T Cell Function in Melanoma

    Science.gov (United States)

    2015-05-01

    reads. Highly represented phage have been subcloned and are being tested for in vitro function. We have identified one phage that augments T...other cell populations, and subclone differentially expressed sequences the phage backbone for functional assessment (or have peptides synthesized

  14. Deleterious effect of ultraviolet-B radiation on accessory function of human blood adherent mononuclear cells

    International Nuclear Information System (INIS)

    Rich, E.A.; Elmets, C.A.; Fujiwara, H.; Wallis, R.S.; Ellner, J.J.

    1987-01-01

    The effects of ultraviolet-B radiation (UV-B) on accessory function of human blood adherent mononuclear cells (ADH) for antigen and mitogen-induced responses, and production by ADH of the amplifying cytokine interleukin 1 (IL-1) were examined. Responder lymphocytes were rendered accessory cell dependent by treatment of nonadherent cells with OKIal + complement. UV-B depressed accessory function of ADH in a dose-dependent manner. UV-B decreased accessory function of ADH for tetanus toxoid-induced responses and phytohaemagglutinin-induced responses. UV-B also decreased accessory activity of peripheral blood mononuclear cells but not Epstein-Barr virus-transformed B cells for a PPD-reactive T cell line. Interleukin 1 (IL-1) activity of supernatants of ADH was assayed on C3H/HeJ mouse thymocytes. Pretreatment of ADH with UV-B decreased lipopolysaccharide-stimulated IL-1 activity. Lysates of UV-B irradiated, LPS-stimulated ADH had no discernible IL-1 activity. Addition of IL-1 partially restored accessory activity of UV-B irradiated ADH for lymphocyte responses to TT. Exposure of ADH to TT or PHA for 30 min before irradiation blocked the inhibitory effect of UV-B on accessory activity. Thus, low doses of UV-B are deleterious to accessory function and to production of IL-1 by ADH. Interference with production of cytokines and with initial interactions of accessory cells with antigen and mitogen may be critical to the effects of UV-B on immunoregulatory function of ADH. (author)

  15. Function of survivin in trophoblastic cells of the placenta.

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    Cornelia Muschol-Steinmetz

    Full Text Available BACKGROUND: Preeclampsia is one of the leading causes of maternal and perinatal mortality and morbidity worldwide and its pathogenesis is not totally understood. As a member of the chromosomal passenger complex and an inhibitor of apoptosis, survivin is a well-characterized oncoprotein. Its roles in trophoblastic cells remain to be defined. METHODS: The placental samples from 16 preeclampsia patients and 16 well-matched controls were included in this study. Real-time PCR, immunohistochemistry and Western blot analysis were carried out with placental tissues. Primary trophoblastic cells from term placentas were isolated for Western blot analysis. Cell proliferation, cell cycle analysis and immunofluorescence staining were performed in trophoblastic cell lines BeWo, JAR and HTR-8/SVneo. RESULTS: The survivin gene is reduced but the protein amount is hardly changed in preeclamptic placentas, compared to control placentas. Upon stress, survivin in trophoblastic cells is phosphorylated on its residue serine 20 by protein kinase A and becomes stabilized, accompanied by increased heat shock protein 90. Depletion of survivin induces chromosome misalignment, abnormal centrosome integrity, and reduced localization and activity of Aurora B at the centromeres/kinetochores in trophoblastic metaphase cells. CONCLUSIONS: Our data indicate that survivin plays pivotal roles in cell survival and proliferation of trophoblastic cells. Further investigations are required to define the function of survivin in each cell type of the placenta in the context of proliferation, differentiation, apoptosis, angiogenesis, migration and invasion.

  16. XIAP reverses various functional activities of FRNK in endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sunyoung; Kim, Hyun Jeong [Department of Molecular Biology and Institute of Nanosensor and Biotechnology, BK21 Graduate Program for RNA Biology, Dankook Univiersity, 126, Jukjeon-dong, Suji-gu, Yongin-si, Gyeonggi-do 448-701 (Korea, Republic of); Chi, Sung-Gil [School of Life Sciences and Biotechnology, Korea University, Seoul 136-701 (Korea, Republic of); Park, Heonyong, E-mail: heonyong@dankook.ac.kr [Department of Molecular Biology and Institute of Nanosensor and Biotechnology, BK21 Graduate Program for RNA Biology, Dankook Univiersity, 126, Jukjeon-dong, Suji-gu, Yongin-si, Gyeonggi-do 448-701 (Korea, Republic of)

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer FRNK domain is recruited into focal adhesion (FA), controlling endothelial cell adhesion. Black-Right-Pointing-Pointer XIAP binds the FRNK domain of FAK. Black-Right-Pointing-Pointer XIAP inhibits recruitment of FRNK into Fas and FRNK-promoted cell adhesion. Black-Right-Pointing-Pointer XIAP plays a key role in vascular functions of FRNK or FRNK domain-mediated vascular functions of FAK. -- Abstract: In endothelial cells, focal adhesion kinase (FAK) regulates cell proliferation, migration, adhesion, and shear-stimulated activation of MAPK. We recently found that FAK is recruited into focal adhesion (FA) sites through interactions with XIAP (X-chromosome linked inhibitor of apoptosis protein) and activated by Src kinase in response to shear stress. In this study, we examined which domain(s) of FAK is(are) important for various vascular functions such as FA recruiting, XIAP-binding and shear stress-stimulated ERK activation. Through a series of experiments, we determined that the FRNK domain is recruited into FA sites and promotes endothelial cell adhesion. Interestingly, XIAP knockdown was shown to reduce FA recruitment of FRNK and the cell adhesive effect of FRNK. In addition, we found that XIAP interacts with FRNK, suggesting cross-talk between XIAP and FRNK. We also demonstrated that FRNK inhibits endothelial cell migration and shear-stimulated ERK activation. These inhibitory effects of FRNK were reversed by XIAP knockdown. Taken together, we can conclude that XIAP plays a key role in vascular functions of FRNK or FRNK domain-mediated vascular functions of FAK.

  17. The development and survival but not function of follicular B cells is dependent on IL-7Rα Tyr449 signaling.

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    Daniel T Patton

    Full Text Available IL-7 is a critical cytokine for lymphocyte development. Recent work has highlighted critical roles for IL-7 signaling in mature T cell homeostasis and function, but its role in B cells is less well characterized. Using a knock-in mouse possessing a Tyr to Phe mutation at position 449 (IL-7Rα(449F/449F mice within the cytoplasmic SH2-binding motif of IL-7Rα, we evaluated the role of IL-7Rα Y449 motif in spleen B cells. IL-7Rα(449F/449F mice had reduced numbers and increased death of follicular B cells compared to WT, but had significantly more follicular cells than IL-7Rα(-/-. The death of IL-7Rα(449F/449F follicular cells was not due to a failure to respond to BAFF or lower levels of BAFF, a critical B cell survival factor. Marginal zone B cells were unaffected by the IL-7Rα(449F/449F mutation. Any role for TSLP was ruled out, as TSLPR(-/- mice had an identical B cell phenotype to wild-type mice. Bone marrow chimeras and the absence of IL-7Rα on B cells suggested that IL-7 did not directly regulate mature B cells, but that an IL-7-responsive cell was influencing B cells. IL-7 was also critical at the checkpoint between the T1 and T2 stages in the spleen. IL-7Rα(-/- mice fail to develop T2 cells, but IL-7Rα(449F/449F show a reduction compared to WT but not complete absence of T2 cells. We also tested the functional responses of IL-7Rα(449F/449F to antigens and infection and found no difference in antibody responses to T-dependent or T-independent antigens, or to Influenza/A. IL-7 was important for generation of antibody responses to the intestinal worm H. polygyrus and for naive levels of IgA. Taken together, this suggests that IL-7 regulates follicular B cell numbers and survival in a cell-extrinsic manner, via a bone-marrow derived cell, but is not critical for antibody production outside the gut.

  18. Activated NKT cells imprint NK-cell differentiation, functionality and education.

    Science.gov (United States)

    Riese, Peggy; Trittel, Stephanie; May, Tobias; Cicin-Sain, Luka; Chambers, Benedict J; Guzmán, Carlos A

    2015-06-01

    NK cells represent a vital component of the innate immune system. The recent discoveries demonstrating that the functionality of NK cells depends on their differentiation and education status underscore their potential as targets for immune intervention. However, to exploit their full potential, a detailed understanding of the cellular interactions involved in these processes is required. In this regard, the cross-talk between NKT cells and NK cells needs to be better understood. Our results provide strong evidence for NKT cell-induced effects on key biological features of NK cells. NKT-cell activation results in the generation of highly active CD27(high) NK cells with improved functionality. In this context, degranulation activity and IFNγ production were mainly detected in the educated subset. In a mCMV infection model, we also demonstrated that NKT-cell stimulation induced the generation of highly functional educated and uneducated NK cells, crucial players in viral control. Thus, our findings reveal new fundamental aspects of the NKT-NK cell axis that provide important hints for the manipulation of NK cells in clinical settings. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Effects of Radiation on Proteasome Function in Prostate Cancer Cells

    Science.gov (United States)

    2012-02-01

    radiation treatment may ultimately improve curability and may allow for de -escalation of the total radiation doses currently given to breast cancer ...Radiation-induced cancer stem cells 15 Figure 3. Radiation induces de novo generation of functional CSCs. ZsGreen-cODC-negative cells...advanced cancer of the uterine cervix . Cancer Res 1996;56(19):4509–4515. 98 Brizel DM, Scully SP, Harrelson JM et al. Tumor oxygenation pre- dicts for

  20. Alternative mitochondrial functions in cell physiopathology: beyond ATP production

    Directory of Open Access Journals (Sweden)

    Kowaltowski A.J.

    2000-01-01

    Full Text Available It is well known that mitochondria are the main site for ATP generation within most tissues. However, mitochondria also participate in a surprising number of alternative activities, including intracellular Ca2+ regulation, thermogenesis and the control of apoptosis. In addition, mitochondria are the main cellular generators of reactive oxygen species, and may trigger necrotic cell death under conditions of oxidative stress. This review concentrates on these alternative mitochondrial functions, and their role in cell physiopathology.

  1. A Molecular and Clinical Review of Stem Cell Therapy in Critical Limb Ischemia

    Directory of Open Access Journals (Sweden)

    Punam P. Parikh

    2017-01-01

    Full Text Available Peripheral artery disease (PAD is one of the major vascular complications in individuals suffering from diabetes and in the elderly that can progress to critical limb ischemia (CLI, portending significant burden in terms of patient morbidity and mortality. Over the last two decades, stem cell therapy (SCT has risen as an attractive alternative to traditional surgical and/or endovascular revascularization to treat this disorder. The primary benefit of SCT is to induce therapeutic neovascularization and promote collateral vessel formation to increase blood flow in the ischemic limb and soft tissue. Existing evidence provides a solid rationale for ongoing in-depth studies aimed at advancing current SCT that may change the way PAD/CLI patients are treated.

  2. A Molecular and Clinical Review of Stem Cell Therapy in Critical Limb Ischemia.

    Science.gov (United States)

    Parikh, Punam P; Liu, Zhao-Jun; Velazquez, Omaida C

    2017-01-01

    Peripheral artery disease (PAD) is one of the major vascular complications in individuals suffering from diabetes and in the elderly that can progress to critical limb ischemia (CLI), portending significant burden in terms of patient morbidity and mortality. Over the last two decades, stem cell therapy (SCT) has risen as an attractive alternative to traditional surgical and/or endovascular revascularization to treat this disorder. The primary benefit of SCT is to induce therapeutic neovascularization and promote collateral vessel formation to increase blood flow in the ischemic limb and soft tissue. Existing evidence provides a solid rationale for ongoing in-depth studies aimed at advancing current SCT that may change the way PAD/CLI patients are treated.

  3. The neuropeptide alpha-melanocyte-stimulating hormone is critically involved in the development of cytotoxic CD8+ T cells in mice and humans.

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    Karin Loser

    Full Text Available BACKGROUND: The neuropeptide alpha-melanocyte-stimulating hormone is well known as a mediator of skin pigmentation. More recently, it has been shown that alpha-melanocyte-stimulating hormone also plays pivotal roles in energy homeostasis, sexual function, and inflammation or immunomodulation. Alpha-melanocyte-stimulating hormone exerts its antiinflammatory and immunomodulatory effects by binding to the melanocortin-1 receptor, and since T cells are important effectors during immune responses, we investigated the effects of alpha-melanocyte-stimulating hormone on T cell function. METHODOLOGY/PRINCIPAL FINDINGS: T cells were treated with alpha-melanocyte-stimulating hormone, and subsequently, their phenotype and function was analyzed in a contact allergy as well as a melanoma model. Furthermore, the relevance of alpha-melanocyte-stimulating hormone-mediated signaling for the induction of cytotoxicity was assessed in CD8(+ T cells from melanoma patients with functional and nonfunctional melanocortin-1 receptors. Here we demonstrate that the melanocortin-1 receptor is expressed by murine as well as human CD8(+ T cells, and we furthermore show that alpha-melanocyte-stimulating hormone/melanocortin-1 receptor-mediated signaling is critical for the induction of cytotoxicity in human and murine CD8(+ T cells. Upon adoptive transfer, alpha-melanocyte-stimulating hormone-treated murine CD8(+ T cells significantly reduced contact allergy responses in recipient mice. Additionally, the presented data indicate that alpha-melanocyte-stimulating hormone via signaling through a functional melanocortin-1 receptor augmented antitumoral immunity by up-regulating the expression of cytotoxic genes and enhancing the cytolytic activity in tumor-specific CD8(+ T cells. CONCLUSIONS/SIGNIFICANCE: Together, these results point to an important role of alpha-melanocyte-stimulating hormone in MHC class I-restricted cytotoxicity. Therefore, treatment of contact allergies or

  4. Cytoskeletal actin networks in motile cells are critically self-organized systems synchronized by mechanical interactions

    Science.gov (United States)

    Cardamone, Luca; Laio, Alessandro; Torre, Vincent; Shahapure, Rajesh; DeSimone, Antonio

    2011-01-01

    Growing networks of actin fibers are able to organize into compact, stiff two-dimensional structures inside lamellipodia of crawling cells. We put forward the hypothesis that the growing actin network is a critically self-organized system, in which long-range mechanical stresses arising from the interaction with the plasma membrane provide the selective pressure leading to organization. We show that a simple model based only on this principle reproduces the stochastic nature of lamellipodia protrusion (growth periods alternating with fast retractions) and several of the features observed in experiments: a growth velocity initially insensitive to the external force; the capability of the network to organize its orientation; a load-history-dependent growth velocity. Our model predicts that the spectrum of the time series of the height of a growing lamellipodium decays with the inverse of the frequency. This behavior is a well-known signature of self-organized criticality and is confirmed by unique optical tweezer measurements performed in vivo on neuronal growth cones. PMID:21825142

  5. eLearning to facilitate the education and implementation of the Chelsea Critical Care Physical Assessment: a novel measure of function in critical illness

    Science.gov (United States)

    Corner, Evelyn J; Handy, Jonathan M; Brett, Stephen J

    2016-01-01

    Objective To evaluate the efficacy of eLearning in the widespread standardised teaching, distribution and implementation of the Chelsea Critical Care Physical Assessment (CPAx) tool—a validated tool to assess physical function in critically ill patients. Design Prospective educational study. An eLearning module was developed through a conceptual framework, using the four-stage technique for skills teaching to teach clinicians how to use the CPAx. Example and test video case studies of CPAx assessments were embedded within the module. The CPAx scores for the test case studies and demographic data were recorded in a secure area of the website. Data were analysed for inter-rater reliability using intraclass correlation coefficients (ICCs) to see if an eLearning educational package facilitated consistent use of the tool. A utility and content validity questionnaire was distributed after 1 year to eLearning module registrants (n=971). This was to evaluate uptake of the CPAx in clinical practice and content validity of the CPAx from the perspective of clinical users. Setting The module was distributed for use via professional forums (n=2) and direct contacts (n=95). Participants Critical care clinicians. Primary outcome measure ICC of the test case studies. Results Between July and October 2014, 421 candidates from 15 countries registered for the eLearning module. The ICC for case one was 0.996 (95% CI 0.990 to 0.999; n=207). The ICC for case two was 0.988 (0.996 to 1.000; n=184). The CPAx has a strong total scale content validity index (s-CVI) of 0.94 and is well used. Conclusions eLearning is a useful and reliable way of teaching psychomotor skills, such as the CPAx. The CPAx is a well-used measure with high content validity rated by clinicians. PMID:27067895

  6. Glucose metabolism regulates T cell activation, differentiation and functions

    Directory of Open Access Journals (Sweden)

    Clovis Steve Palmer

    2015-01-01

    Full Text Available The adaptive immune system is equipped to eliminate both tumors and pathogenic microorganisms. It requires a series of complex and coordinated signals to drive the activation, proliferation and differentiation of appropriate T cell subsets. It is now established that changes in cellular activation are coupled to profound changes in cellular metabolism. In addition, emerging evidence now suggest that specific metabolic alterations associated with distinct T cell subsets may be ancillary to their differentiation and influential in their immune functions. The Warburg effect originally used to describe a phenomenon in which most cancer cells relied on aerobic glycolysis for their growth is a key process that sustain T cell activation and differentiation. Here we review how different aspects of metabolism in T cells influence their functions, focusing on the emerging role of key regulators of glucose metabolism such as HIF-1α. A thorough understanding of the role of metabolism in T cell function could provide insights into mechanisms involved in inflammatory-mediated conditions, with the potential for developing novel therapeutic approaches to treat these diseases.

  7. Identification of critical residues of linear B cell epitope on Goodpasture autoantigen.

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    Xiao-yu Jia

    Full Text Available The autoantigen of anti-glomerular basement membrane (GBM disease has been identified as the non-collagenous domain 1 of α3 chain of type IV collagen, α3(IVNC1. Our previous study revealed a peptide on α3(IVNC1 as a major linear epitope for B cells and potentially nephrogenic, designated as P14 (α3129-150. This peptide has also been proven to be the epitope of auto-reactive T cells in anti-GBM patients. This study was aimed to further characterize the critical motif of P14.16 patients with anti-GBM disease and positive anti-P14 antibodies were enrolled. A set of truncated and alanine substituted peptides derived from P14 were synthesized. Circulating antibodies against the peptides were detected by enzyme linked immunosorbent assay (ELISA.We found that all sera with anti-P14 antibodies reacted with the 13-mer sequence in the C-terminus of P14 (P14c exclusively. The level of antibodies against P14 was highly correlated with the level of antibodies against P14c (r=0.970, P<0.001. P14c was the core immunogenic region and the amino acid sequence (ISLWKGFSFIMFT was highly hydrophobic. Each amino acid residue in P14c was sequentially replaced by alanine. Three residues of glycine142, phenylalanine143, and phenylalanine145 were identified crucial for antibody binding based on the remarkable decline (P<0.001 of antibody reaction after each residue replacement.We defined GFxF (α3142, 143,145 as the critical motif of P14. It may provide some clues for understanding the etiology of anti-GBM disease.

  8. Plant and algal cell walls: diversity and functionality.

    Science.gov (United States)

    Popper, Zoë A; Ralet, Marie-Christine; Domozych, David S

    2014-10-01

    Although plants and many algae (e.g. the Phaeophyceae, brown, and Rhodophyceae, red) are only very distantly related they are united in their possession of carbohydrate-rich cell walls, which are of integral importance being involved in many physiological processes. Furthermore,wall components have applications within food, fuel, pharmaceuticals, fibres (e.g. for textiles and paper) and building materials and have long been an active topic of research. As shown in the 27 papers in this Special Issue, as the major deposit of photosynthetically fixed carbon, and therefore energy investment, cell walls are of undisputed importance to the organisms that possess them, the photosynthetic eukaryotes ( plants and algae). The complexities of cell wall components along with their interactions with the biotic and abiotic environment are becoming increasingly revealed. The importance of plant and algal cell walls and their individual components to the function and survival of the organism, and for a number of industrial applications, are illustrated by the breadth of topics covered in this issue, which includes papers concentrating on various plants and algae, developmental stages, organs, cell wall components, and techniques. Although we acknowledge that there are many alternative ways in which the papers could be categorized (and many would fit within several topics), we have organized them as follows: (1) cell wall biosynthesis and remodelling, (2) cell wall diversity, and (3) application of new technologies to cell walls. Finally, we will consider future directions within plant cell wall research. Expansion of the industrial uses of cell walls and potentially novel uses of cell wall components are both avenues likely to direct future research activities. Fundamentally, it is the continued progression from characterization (structure, metabolism, properties and localization) of individual cell wall components through to defining their roles in almost every aspect of plant

  9. Defective immunoregulatory T-cell function in chronic lymphocytic leukemia

    International Nuclear Information System (INIS)

    Han, T.; Ozer, H.; Henderson, E.S.; Dadey, B.; Nussbaum-Blumenson, A.; Barcos, M.

    1981-01-01

    Chronic lymphocytic leukemia (CLL) of B-cell origin results in the malignant proliferation of small immunoglobulin-bearing lymphocytes. There is currently a controversy in the literature regarding both the ability of this leukemic population to differentiate into mature plasma cells, as well as the ability of apparently normal T cells from these patients to regulate allogeneic B-cell differentiation. In the present study we have examined the lymphocytes of CLL patients in various clinical stages of their disease and with different surface phenotypes of their leukemic B-cell population. Our results show that leukemic CLL B cells from all 20 patients (including one patient with a monoclonal IgM paraprotein and another with a monoclonal IgG paraprotein) are incapable of further differentiation even in the absence of suppressor T cells and the presence of helper T lymphocytes. This lack of capacity to differentiate is unaffected by clinical stage, by therapy, or by the phenotype of the malignant population. Since the leukemic B population did not suppress normal allogeneic B-cell differentiation, the maturation deficit is evidently intrinsic to the leukemic clone rather than a result of activity of non-T suppressor cells. T helper function was also variably depressed in the blood of some patients with CLL, and this depression did not correlate with clinical stage, with therapy, or with the degree of lymphocytosis. Dysfunction of radiosensitive T suppressor cells was found to be the most consistent regulatory deficit of CLL T cells. Each of 11 patients whose leukemic cell population was of the μdelta, μα, or μ phenotype had both helper and suppressor cell defects

  10. Imbalanced expression of functional surface molecules in regulatory and effector T cells in systemic lupus erythematosus

    International Nuclear Information System (INIS)

    Mesquita Júnior, D.; Cruvinel, W.M.; Araujo, J.A.P.; Salmazi, K.C.; Kallas, E.G.; Andrade, L.E.C.

    2014-01-01

    Regulatory T (TREG) cells play an important role in maintaining immune tolerance and avoiding autoimmunity. We analyzed the expression of membrane molecules in TREG and effector T cells in systemic lupus erythematosus (SLE). TREG and effector T cells were analyzed for the expression of CTLA-4, PD1, CD28, CD95, GITR, HLA-DR, OX40, CD40L, and CD45RO in 26 patients with active disease, 31 with inactive disease, and 26 healthy controls. TREG cells were defined as CD25 +/high CD127 Ø/low FoxP3 + , and effector T cells were defined as CD25 + CD127 + FoxP3 Ø . The ratio of TREG to effector T cells expressing GITR, PD1, HLA-DR, OX40, CD40L, and CD45RO was determined in the three groups. The frequency of TREG cells was similar in patients with SLE and controls. However, SLE patients had a decreased frequency of CTLA-4 + TREG and CD28 + TREG cells and an increased frequency of CD40L + TREG cells. There was a decrease in the TREG/effector-T ratio for GITR + , HLA-DR + , OX40 + , and CD45RO + cells, and an increased ratio of TREG/effector-T CD40L + cells in patients with SLE. In addition, CD40L + TREG cell frequency correlated with the SLE disease activity index (P=0.0163). In conclusion, our findings showed several abnormalities in the expression of functionally critical surface molecules in TREG and effector T cells in SLE that may be relevant to the pathogenesis of this disease

  11. Imbalanced expression of functional surface molecules in regulatory and effector T cells in systemic lupus erythematosus

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita Júnior, D. [Disciplina de Reumatologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Cruvinel, W.M. [Disciplina de Reumatologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Departamento de Biomedicina, Universidade Católica de Goiás, Goiânia, GO (Brazil); Araujo, J.A.P. [Disciplina de Reumatologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Salmazi, K.C.; Kallas, E.G. [Disciplina de Imunologia Clínica e Alergia, Departamento de Clínica Médica, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Andrade, L.E.C. [Disciplina de Reumatologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil)

    2014-08-22

    Regulatory T (TREG) cells play an important role in maintaining immune tolerance and avoiding autoimmunity. We analyzed the expression of membrane molecules in TREG and effector T cells in systemic lupus erythematosus (SLE). TREG and effector T cells were analyzed for the expression of CTLA-4, PD1, CD28, CD95, GITR, HLA-DR, OX40, CD40L, and CD45RO in 26 patients with active disease, 31 with inactive disease, and 26 healthy controls. TREG cells were defined as CD25{sup +/high}CD127{sup Ø/low}FoxP3{sup +}, and effector T cells were defined as CD25{sup +}CD127{sup +}FoxP3{sup Ø}. The ratio of TREG to effector T cells expressing GITR, PD1, HLA-DR, OX40, CD40L, and CD45RO was determined in the three groups. The frequency of TREG cells was similar in patients with SLE and controls. However, SLE patients had a decreased frequency of CTLA-4{sup +}TREG and CD28{sup +}TREG cells and an increased frequency of CD40L{sup +}TREG cells. There was a decrease in the TREG/effector-T ratio for GITR{sup +}, HLA-DR{sup +}, OX40{sup +}, and CD45RO{sup +} cells, and an increased ratio of TREG/effector-T CD40L{sup +} cells in patients with SLE. In addition, CD40L{sup +}TREG cell frequency correlated with the SLE disease activity index (P=0.0163). In conclusion, our findings showed several abnormalities in the expression of functionally critical surface molecules in TREG and effector T cells in SLE that may be relevant to the pathogenesis of this disease.

  12. Eps8 regulates hair bundle length and functional maturation of mammalian auditory hair cells.

    Directory of Open Access Journals (Sweden)

    Valeria Zampini

    2011-04-01

    Full Text Available Hair cells of the mammalian cochlea are specialized for the dynamic coding of sound stimuli. The transduction of sound waves into electrical signals depends upon mechanosensitive hair bundles that project from the cell's apical surface. Each stereocilium within a hair bundle is composed of uniformly polarized and tightly packed actin filaments. Several stereociliary proteins have been shown to be associated with hair bundle development and function and are known to cause deafness in mice and humans when mutated. The growth of the stereociliar actin core is dynamically regulated at the actin filament barbed ends in the stereociliary tip. We show that Eps8, a protein with actin binding, bundling, and barbed-end capping activities in other systems, is a novel component of the hair bundle. Eps8 is localized predominantly at the tip of the stereocilia and is essential for their normal elongation and function. Moreover, we have found that Eps8 knockout mice are profoundly deaf and that IHCs, but not OHCs, fail to mature into fully functional sensory receptors. We propose that Eps8 directly regulates stereocilia growth in hair cells and also plays a crucial role in the physiological maturation of mammalian cochlear IHCs. Together, our results indicate that Eps8 is critical in coordinating the development and functionality of mammalian auditory hair cells.

  13. Eps8 regulates hair bundle length and functional maturation of mammalian auditory hair cells.

    Science.gov (United States)

    Zampini, Valeria; Rüttiger, Lukas; Johnson, Stuart L; Franz, Christoph; Furness, David N; Waldhaus, Jörg; Xiong, Hao; Hackney, Carole M; Holley, Matthew C; Offenhauser, Nina; Di Fiore, Pier Paolo; Knipper, Marlies; Masetto, Sergio; Marcotti, Walter

    2011-04-01

    Hair cells of the mammalian cochlea are specialized for the dynamic coding of sound stimuli. The transduction of sound waves into electrical signals depends upon mechanosensitive hair bundles that project from the cell's apical surface. Each stereocilium within a hair bundle is composed of uniformly polarized and tightly packed actin filaments. Several stereociliary proteins have been shown to be associated with hair bundle development and function and are known to cause deafness in mice and humans when mutated. The growth of the stereociliar actin core is dynamically regulated at the actin filament barbed ends in the stereociliary tip. We show that Eps8, a protein with actin binding, bundling, and barbed-end capping activities in other systems, is a novel component of the hair bundle. Eps8 is localized predominantly at the tip of the stereocilia and is essential for their normal elongation and function. Moreover, we have found that Eps8 knockout mice are profoundly deaf and that IHCs, but not OHCs, fail to mature into fully functional sensory receptors. We propose that Eps8 directly regulates stereocilia growth in hair cells and also plays a crucial role in the physiological maturation of mammalian cochlear IHCs. Together, our results indicate that Eps8 is critical in coordinating the development and functionality of mammalian auditory hair cells.

  14. Designing pinhole vacancies in graphene towards functionalization: Effects on critical buckling load

    Science.gov (United States)

    Georgantzinos, S. K.; Markolefas, S.; Giannopoulos, G. I.; Katsareas, D. E.; Anifantis, N. K.

    2017-03-01

    The effect of size and placement of pinhole-type atom vacancies on Euler's critical load on free-standing, monolayer graphene, is investigated. The graphene is modeled by a structural spring-based finite element approach, in which every interatomic interaction is approached as a linear spring. The geometry of graphene and the pinhole size lead to the assembly of the stiffness matrix of the nanostructure. Definition of the boundary conditions of the problem leads to the solution of the eigenvalue problem and consequently to the critical buckling load. Comparison to results found in the literature illustrates the validity and accuracy of the proposed method. Parametric analysis regarding the placement and size of the pinhole-type vacancy, as well as the graphene geometry, depicts the effects on critical buckling load. Non-linear regression analysis leads to empirical-analytical equations for predicting the buckling behavior of graphene, with engineered pinhole-type atom vacancies.

  15. Form and function in cell motility: from fibroblasts to keratocytes.

    Science.gov (United States)

    Herant, Marc; Dembo, Micah

    2010-04-21

    It is plain enough that a horse is made for running, but similar statements about motile cells are not so obvious. Here the basis for structure-function relations in cell motility is explored by application of a new computational technique that allows realistic three-dimensional simulations of cells migrating on flat substrata. With this approach, some cyber cells spontaneously display the classic irregular protrusion cycles and handmirror morphology of a crawling fibroblast, and others the steady gliding motility and crescent morphology of a fish keratocyte. The keratocyte motif is caused by optimal recycling of the cytoskeleton from the back to the front so that more of the periphery can be devoted to protrusion. These calculations are a step toward bridging the gap between the integrated mechanics and biophysics of whole cells and the microscopic molecular biology of cytoskeletal components. Copyright 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  16. Rescue of Brain Function Using Tunneling Nanotubes Between Neural Stem Cells and Brain Microvascular Endothelial Cells.

    Science.gov (United States)

    Wang, Xiaoqing; Yu, Xiaowen; Xie, Chong; Tan, Zijian; Tian, Qi; Zhu, Desheng; Liu, Mingyuan; Guan, Yangtai

    2016-05-01

    Evidence indicates that neural stem cells (NSCs) can ameliorate cerebral ischemia in animal models. In this study, we investigated the mechanism underlying one of the neuroprotective effects of NSCs: tunneling nanotube (TNT) formation. We addressed whether the control of cell-to-cell communication processes between NSCs and brain microvascular endothelial cells (BMECs) and, particularly, the control of TNT formation could influence the rescue function of stem cells. In an attempt to mimic the cellular microenvironment in vitro, a co-culture system consisting of terminally differentiated BMECs from mice in a distressed state and NSCs was constructed. Additionally, engraftment experiments with infarcted mouse brains revealed that control of TNT formation influenced the effects of stem cell transplantation in vivo. In conclusion, our findings provide the first evidence that TNTs exist between NSCs and BMECs and that regulation of TNT formation alters cell function.

  17. Functionalized scaffolds to control dental pulp stem cell fate

    Science.gov (United States)

    Piva, Evandro; Silva, Adriana F.; Nör, Jacques E.

    2014-01-01

    Emerging understanding about interactions between stem cells, scaffolds and morphogenic factors has accelerated translational research in the field of dental pulp tissue engineering. Dental pulp stem cells constitute a sub-population of cells endowed with self-renewal and multipotency. Dental pulp stem cells seeded in biodegradable scaffolds and exposed to dentin-derived morphogenic signals give rise to a pulp-like tissue capable of generating new dentin. Notably, dentin-derived proteins are sufficient to induce dental pulp stem cell differentiation into odontoblasts. Ongoing work is focused on developing ways of mobilizing dentin-derived proteins and disinfecting the root canal of necrotic teeth without compromising the morphogenic potential of these signaling molecules. On the other hand, dentin by itself does not appear to be capable of inducing endothelial differentiation of dental pulp stem cells, despite the well known presence of angiogenic factors in dentin. This is particularly relevant in the context of dental pulp tissue engineering in full root canals, where access to blood supply is limited to the apical foramina. To address this challenge, scientists are looking at ways to use the scaffold as a controlled release device for angiogenic factors. The aim of this manuscript is to present and discuss current strategies to functionalize injectable scaffolds and customize them for dental pulp tissue engineering. The long-term goal of this work is to develop stem cell-based therapies that enable the engineering of functional dental pulps capable of generating new tubular dentin in humans. PMID:24698691

  18. Targeted Gene Deletion Demonstrates that Cell Adhesion MoleculeICAM-4 is Critical for Erythroblastic Island Formation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Gloria; Lo, Annie; Short, Sarah A.; Mankelow, Tosti J.; Spring, Frances; Parsons, Stephen F.; Mohandas, Narla; Anstee, David J.; Chasis, Joel Anne

    2006-02-15

    Erythroid progenitors differentiate in erythroblastic islands, bone marrow niches composed of erythroblasts surrounding a central macrophage. Evidence suggests that within islands adhesive interactions regulate erythropoiesis and apoptosis. We are exploring whether erythroid intercellular adhesion molecule-4 (ICAM-4), animmunoglobulin superfamily member, participates in island formation. Earlier, we identified alpha V integrins as ICAM-4 counter receptors. Since macrophages express alpha V, ICAM-4 potentially mediates island attachments. To test this, we generated ICAM-4 knockout mice and developed quantitative, live cell techniques for harvesting intact islands and for reforming islands in vitro. We observed a 47 percent decrease in islands reconstituted from ICAM-4 null marrow compared to wild type. We also found a striking decrease in islands formed in vivo in knockout mice. Further, peptides that block ICAM-4 alpha V adhesion produced a 53-57 percent decrease in reconstituted islands, strongly suggesting that ICAM-4 binding to macrophage alpha V functions in island integrity. Importantly, we documented that alpha V integrin is expressed in macrophages isolated from erythro blastic islands. Collectively, these data provide convincing evidence that ICAM-4 is critical in erythroblastic island formation via ICAM-4/alpha V adhesion and also demonstrate that the novel experimental strategies we developed will be valuable in exploring molecular mechanisms of erythroblastic island formation and their functional role in regulating erythropoiesis.

  19. Cannabidiol (CBD) induces functional Tregs in response to low-level T cell activation.

    Science.gov (United States)

    Dhital, Saphala; Stokes, John V; Park, Nogi; Seo, Keun Seok; Kaplan, Barbara L F

    2017-02-01

    Many effects of the non-psychoactive cannabinoid, cannabidiol (CBD), have been described in immune responses induced by strong immunological stimuli. It has also been shown that CBD enhances IL-2 production in response to low-level T cell stimulation. Since IL-2, in combination with TGF-β1, are critical for Treg induction, we hypothesized that CBD would induce CD4 + CD25 + FOXP3 + Tregs in response to low-level stimulation. Low-level T cell stimulation conditions were established based on minimal CD25 expression in CD4 + cells using suboptimal PMA/Io (4nM/0.05μM, S/o), ultrasuboptimal PMA/Io (1nM/0.0125μM, Us/o) or soluble anti-CD3/28 (400-800ng each, s3/28). CBD increased CD25 + FOXP3 + cells from CD4 + , CD4 + CD25 + , and CD4 + CD25 - T cells, as well as in CD4 + T cells derived from FOXP3-GFP mice. Most importantly, the Us/o+CBD-induced CD4 + CD25 + Tregs robustly suppressed responder T cell proliferation, demonstrating that the mechanism by which CBD is immunosuppressive under low-level T cell stimulation involves induction of functional Tregs. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Functions of Heterogeneous Nuclear Ribonucleoproteins in Stem Cell Potency and Differentiation

    Directory of Open Access Journals (Sweden)

    Qishan Chen

    2013-01-01

    Full Text Available Stem cells possess huge importance in developmental biology, disease modelling, cell replacement therapy, and tissue engineering in regenerative medicine because they have the remarkable potential for self-renewal and to differentiate into almost all the cell types in the human body. Elucidation of molecular mechanisms regulating stem cell potency and differentiation is essential and critical for extensive application. Heterogeneous nuclear ribonucleoproteins (hnRNPs are modular proteins consisting of RNA-binding motifs and auxiliary domains characterized by extensive and divergent functions in nucleic acid metabolism. Multiple roles of hnRNPs in transcriptional and posttranscriptional regulation enable them to be effective gene expression regulators. More recent findings show that hnRNP proteins are crucial factors implicated in maintenance of stem cell self-renewal and pluripotency and cell differentiation. The hnRNPs interact with certain sequences in target gene promoter regions to initiate transcription. In addition, they recognize 3′UTR or 5′UTR of specific gene mRNA forming mRNP complex to regulate mRNA stability and translation. Both of these regulatory pathways lead to modulation of gene expression that is associated with stem cell proliferation, cell cycle control, pluripotency, and committed differentiation.

  1. Regulatory function of a novel population of mouse autoantigen-specific Foxp3 regulatory T cells depends on IFN-gamma, NO, and contact with target cells.

    Directory of Open Access Journals (Sweden)

    Cyndi Chen

    Full Text Available BACKGROUND: Both naturally arising Foxp3(+ and antigen-induced Foxp3(- regulatory T cells (Treg play a critical role in regulating immune responses, as well as in preventing autoimmune diseases and graft rejection. It is known that antigen-specific Treg are more potent than polyclonal Treg in suppressing pathogenic immune responses that cause autoimmunity and inflammation. However, difficulty in identifying and isolating a sufficient number of antigen-specific Treg has limited their use in research to elucidate the mechanisms underlying their regulatory function and their potential role in therapy. METHODOLOGY/PRINCIPAL FINDINGS: Using a novel class II MHC tetramer, we have isolated a population of CD4(+ Foxp3(- T cells specific for the autoantigen glutamic acid decarboxylase p286-300 peptide (NR286 T cells from diabetes-resistant non-obese resistant (NOR mice. These Foxp3(- NR286 T cells functioned as Treg that were able to suppress target T cell proliferation in vitro and inhibit type 1 diabetes in animals. Unexpected results from mechanistic studies in vitro showed that their regulatory function was dependent on not only IFN-gamma and nitric oxide, but also on cell contact with target cells. In addition, separating NR286 Treg from target T cells in transwell assays abolished both production of NO and suppression of target T cells, regardless of whether IFN-gamma was produced in cell cultures. Therefore, production of NO, not IFN-gamma, was cell contact dependent, suggesting that NO may function downstream of IFN-gamma in mediating regulatory function of NR286 Treg. CONCLUSIONS/SIGNIFICANCE: These studies identified a unique population of autoantigen-specific Foxp3(- Treg that can exert their regulatory function dependent on not only IFN-gamma and NO but also cell contact with target cells.

  2. Oct4 targets regulatory nodes to modulate stem cell function.

    Directory of Open Access Journals (Sweden)

    Pearl A Campbell

    2007-06-01

    Full Text Available Stem cells are characterized by two defining features, the ability to self-renew and to differentiate into highly specialized cell types. The POU homeodomain transcription factor Oct4 (Pou5f1 is an essential mediator of the embryonic stem cell state and has been implicated in lineage specific differentiation, adult stem cell identity, and cancer. Recent description of the regulatory networks which maintain 'ES' have highlighted a dual role for Oct4 in the transcriptional activation of genes required to maintain self-renewal and pluripotency while concomitantly repressing genes which facilitate lineage specific differentiation. However, the molecular mechanism by which Oct4 mediates differential activation or repression at these loci to either maintain stem cell identity or facilitate the emergence of alternate transcriptional programs required for the realization of lineage remains to be elucidated. To further investigate Oct4 function, we employed gene expression profiling together with a robust statistical analysis to identify genes highly correlated to Oct4. Gene Ontology analysis to categorize overrepresented genes has led to the identification of themes which may prove essential to stem cell identity, including chromatin structure, nuclear architecture, cell cycle control, DNA repair, and apoptosis. Our experiments have identified previously unappreciated roles for Oct4 for firstly, regulating chromatin structure in a state consistent with self-renewal and pluripotency, and secondly, facilitating the expression of genes that keeps the cell poised to respond to cues that lead to differentiation. Together, these data define the mechanism by which Oct4 orchestrates cellular regulatory pathways to enforce the stem cell state and provides important insight into stem cell function and cancer.

  3. Syndecans as cell surface receptors: Unique structure equates with functional diversity

    DEFF Research Database (Denmark)

    Choi, Youngsil; Chung, Heesung; Jung, Heyjung

    2011-01-01

    An increasing number of functions for syndecan cell surface heparan sulfate proteoglycans have been proposed over the last decade. Moreover, aberrant syndecan regulation has been found to play a critical role in multiple pathologies, including cancers, as well as wound healing and inflammation....... As receptors, they have much in common with other molecules on the cell surface. Syndecans are type I transmembrane molecules with cytoplasmic domains that link to the actin cytoskeleton and can interact with a number of regulators. However, they are also highly complex by virtue of their external...... glycosaminoglycan chains, especially heparan sulfate. This heterodisperse polysaccharide has the potential to interact with many ligands from diverse protein families. Here, we relate the structural features of syndecans to some of their known functions....

  4. Corpus linguistics, systemic functional grammar and literary meaning: a critical analysis of harry potter and the philosopher’s stone Corpus linguistics, systemic functional grammar and literary meaning: a critical analysis of harry potter and the philosopher’s stone

    Directory of Open Access Journals (Sweden)

    Andrew Goatly

    2008-04-01

    Full Text Available The research reported in this paper has two aims. First, to show how corpus linguistics, using word frequency and concordance data, which is then analysed according to transitivity systems of systemic functional grammar (SFG, can be useful to the enterprise of critical linguistics. Second, to investigate to what extent this critical corpus linguistics (CCL gives a valid representation of the meanings and ideologies of a literary text. The hypothesis tested is that semiotic models of communication, in this case of popular children’s literature, with their emphasis on the encoding and decoding of meanings, lend themselves to a corpus linguistics approach. But that, in fact, these mutually reinforcing approaches (SFG and CCL with their reliance on what is encoded as text cannot entirely succeed in accounting for how literature, in particular, is understood and interpreted, and how ideology works within it and behind it. For a richer critical discourse analysis we need a pragmatic account, for example an analysis of presupposition, inference and propositional attitude. The issues here will be discussed in the light of recent debate between Michael Stubbs and Henry Widdowson on the strengths and limitations of corpus linguistics in critical discourse analysis. The research reported in this paper has two aims. First, to show how corpus linguistics, using word frequency and concordance data, which is then analysed according to transitivity systems of systemic functional grammar (SFG, can be useful to the enterprise of critical linguistics. Second, to investigate to what extent this critical corpus linguistics (CCL gives a valid representation of the meanings and ideologies of a literary text. The hypothesis tested is that semiotic models of communication, in this case of popular children’s literature, with their emphasis on the encoding and decoding of meanings, lend themselves to a corpus linguistics approach. But that, in fact, these

  5. Linking stem cell function and growth pattern of intestinal organoids.

    Science.gov (United States)

    Thalheim, Torsten; Quaas, Marianne; Herberg, Maria; Braumann, Ulf-Dietrich; Kerner, Christiane; Loeffler, Markus; Aust, Gabriela; Galle, Joerg

    2018-01-15

    Intestinal stem cells (ISCs) require well-defined signals from their environment in order to carry out their specific functions. Most of these signals are provided by neighboring cells that form a stem cell niche, whose shape and cellular composition self-organize. Major features of this self-organization can be studied in ISC-derived organoid culture. In this system, manipulation of essential pathways of stem cell maintenance and differentiation results in well-described growth phenotypes. We here provide an individual cell-based model of intestinal organoids that enables a mechanistic explanation of the observed growth phenotypes. In simulation studies of the 3D structure of expanding organoids, we investigate interdependences between Wnt- and Notch-signaling which control the shape of the stem cell niche and, thus, the growth pattern of the organoids. Similar to in vitro experiments, changes of pathway activities alter the cellular composition of the organoids and, thereby, affect their shape. Exogenous Wnt enforces transitions from branched into a cyst-like growth pattern; known to occur spontaneously during long term organoid expansion. Based on our simulation results, we predict that the cyst-like pattern is associated with biomechanical changes of the cells which assign them a growth advantage. The results suggest ongoing stem cell adaptation to in vitro conditions during long term expansion by stabilizing Wnt-activity. Our study exemplifies the potential of individual cell-based modeling in unraveling links between molecular stem cell regulation and 3D growth of tissues. This kind of modeling combines experimental results in the fields of stem cell biology and cell biomechanics constituting a prerequisite for a better understanding of tissue regeneration as well as developmental processes. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Critical Role of CD2 Co-stimulation in Adaptive Natural Killer Cell Responses Revealed in NKG2C-Deficient Humans.

    Science.gov (United States)

    Liu, Lisa L; Landskron, Johannes; Ask, Eivind H; Enqvist, Monika; Sohlberg, Ebba; Traherne, James A; Hammer, Quirin; Goodridge, Jodie P; Larsson, Stella; Jayaraman, Jyothi; Oei, Vincent Y S; Schaffer, Marie; Taskén, Kjetil; Ljunggren, Hans-Gustaf; Romagnani, Chiara; Trowsdale, John; Malmberg, Karl-Johan; Béziat, Vivien

    2016-05-03

    Infection by human cytomegalovirus (HCMV) leads to NKG2C-driven expansion of adaptive natural killer (NK) cells, contributing to host defense. However, approximately 4% of all humans carry a homozygous deletion of the gene that encodes NKG2C (NKG2C(-/-)). Assessment of NK cell repertoires in 60 NKG2C(-/-) donors revealed a broad range of NK cell populations displaying characteristic footprints of adaptive NK cells, including a terminally differentiated phenotype, functional reprogramming, and epigenetic remodeling of the interferon (IFN)-γ promoter. We found that both NKG2C(-) and NKG2C(+) adaptive NK cells expressed high levels of CD2, which synergistically enhanced ERK and S6RP phosphorylation following CD16 ligation. Notably, CD2 co-stimulation was critical for the ability of adaptive NK cells to respond to antibody-coated target cells. These results reveal an unexpected redundancy in the human NK cell response to HCMV and suggest that CD2 provides "signal 2" in antibody-driven adaptive NK cell responses. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Critical Role of CD2 Co-stimulation in Adaptive Natural Killer Cell Responses Revealed in NKG2C-Deficient Humans

    Directory of Open Access Journals (Sweden)

    Lisa L. Liu

    2016-05-01

    Full Text Available Infection by human cytomegalovirus (HCMV leads to NKG2C-driven expansion of adaptive natural killer (NK cells, contributing to host defense. However, approximately 4% of all humans carry a homozygous deletion of the gene that encodes NKG2C (NKG2C−/−. Assessment of NK cell repertoires in 60 NKG2C−/− donors revealed a broad range of NK cell populations displaying characteristic footprints of adaptive NK cells, including a terminally differentiated phenotype, functional reprogramming, and epigenetic remodeling of the interferon (IFN-γ promoter. We found that both NKG2C− and NKG2C+ adaptive NK cells expressed high levels of CD2, which synergistically enhanced ERK and S6RP phosphorylation following CD16 ligation. Notably, CD2 co-stimulation was critical for the ability of adaptive NK cells to respond to antibody-coated target cells. These results reveal an unexpected redundancy in the human NK cell response to HCMV and suggest that CD2 provides “signal 2” in antibody-driven adaptive NK cell responses.

  8. Non-coding RNAs Functioning in Colorectal Cancer Stem Cells.

    Science.gov (United States)

    Fanale, Daniele; Barraco, Nadia; Listì, Angela; Bazan, Viviana; Russo, Antonio

    In recent years, the hypothesis of the presence of tumor-initiating cancer stem cells (CSCs) has received a considerable support. This model suggested the existence of CSCs which, thanks to their self-renewal properties, are able to drive the expansion and the maintenance of malignant cell populations with invasive and metastatic potential in cancer. Increasing evidence showed the ability of such cells to acquire self-renewal, multipotency, angiogenic potential, immune evasion, symmetrical and asymmetrical divisions which, along with the presence of several DNA repair mechanisms, further enhance their oncogenic potential making them highly resistant to common anticancer treatments. The main signaling pathways involved in the homeostasis of colorectal (CRC) stem cells are the Wnt, Notch, Sonic Hedgehog, and Bone Morfogenic Protein (BMP) pathways, which are mostly responsible for all the features that have been widely referred to stem cells. The same pathways have been identified in colorectal cancer stem cells (CRCSCs), conferring a more aggressive phenotype compared to non-stem CRC cells. Recently, several evidences suggested that non-coding RNAs (ncRNAs) may play a crucial role in the regulation of different biological mechanisms in CRC, by modulating the expression of critical stem cell transcription factors that have been found active in CSCs. In this chapter, we will discuss the involvement of ncRNAs, especially microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), in stemness acquisition and maintenance by CRCSCs, through the regulation of pathways modulating the CSC phenotype and growth, carcinogenesis, differentiation, and epithelial to mesenchymal transition (EMT).

  9. For Function or Transformation? A Critical Discourse Analysis of Education under the Sustainable Development Goals

    Science.gov (United States)

    Brissett, Nigel; Mitter, Radhika

    2017-01-01

    We conduct a critical discourse analysis of the extent to which Sustainable Development Goal 4, "to ensure inclusive and equitable quality education for all and promote lifelong learning," promotes a utilitarian and/or transformative approach to education. Our findings show that despite transformative language used throughout the Agenda,…

  10. Critical Race Theory and the Transfer Function: Introducing a Transfer Receptive Culture

    Science.gov (United States)

    Jain, Dimpal; Herrera, Alfred; Bernal, Santiago; Solorzano, Daniel

    2011-01-01

    In California, the majority of students of color who enter postsecondary education do so in the community colleges. However large numbers of them leave and do not transfer to four-year institutions; in particular to highly selective pubic four-year colleges and universities. By using the theoretical perspective of critical race theory, transfer…

  11. Regulation of Receptor for Advanced Glycation End Products (RAGE) Ectodomain Shedding and Its Role in Cell Function*

    Science.gov (United States)

    Braley, Alex; Kwak, Taekyoung; Jules, Joel; Harja, Evis; Landgraf, Ralf; Hudson, Barry I.

    2016-01-01

    The receptor for advanced glycation end products (RAGE) is a multiligand transmembrane receptor that can undergo proteolysis at the cell surface to release a soluble ectodomain. Here we observed that ectodomain shedding of RAGE is critical for its role in regulating signaling and cellular function. Ectodomain shedding of both human and mouse RAGE was dependent on ADAM10 activity and induced with chemical activators of shedding (ionomycin, phorbol 12-myristate 13-acetate, and 4-aminophenylmercuric acetate) and endogenous stimuli (serum and RAGE ligands). Ectopic expression of the splice variant of RAGE (RAGE splice variant 4), which is resistant to ectodomain shedding, inhibited RAGE ligand dependent cell signaling, actin cytoskeleton reorganization, cell spreading, and cell migration. We found that blockade of RAGE ligand signaling with soluble RAGE or inhibitors of MAPK or PI3K blocked RAGE-dependent cell migration but did not affect RAGE splice variant 4 cell migration. We finally demonstrated that RAGE function is dependent on secretase activity as ADAM10 and γ-secretase inhibitors blocked RAGE ligand-mediated cell migration. Together, our data suggest that proteolysis of RAGE is critical to mediate signaling and cell function and may therefore emerge as a novel therapeutic target for RAGE-dependent disease states. PMID:27022018

  12. Regulation of Receptor for Advanced Glycation End Products (RAGE) Ectodomain Shedding and Its Role in Cell Function.

    Science.gov (United States)

    Braley, Alex; Kwak, Taekyoung; Jules, Joel; Harja, Evis; Landgraf, Ralf; Hudson, Barry I

    2016-06-03

    The receptor for advanced glycation end products (RAGE) is a multiligand transmembrane receptor that can undergo proteolysis at the cell surface to release a soluble ectodomain. Here we observed that ectodomain shedding of RAGE is critical for its role in regulating signaling and cellular function. Ectodomain shedding of both human and mouse RAGE was dependent on ADAM10 activity and induced with chemical activators of shedding (ionomycin, phorbol 12-myristate 13-acetate, and 4-aminophenylmercuric acetate) and endogenous stimuli (serum and RAGE ligands). Ectopic expression of the splice variant of RAGE (RAGE splice variant 4), which is resistant to ectodomain shedding, inhibited RAGE ligand dependent cell signaling, actin cytoskeleton reorganization, cell spreading, and cell migration. We found that blockade of RAGE ligand signaling with soluble RAGE or inhibitors of MAPK or PI3K blocked RAGE-dependent cell migration but did not affect RAGE splice variant 4 cell migration. We finally demonstrated that RAGE function is dependent on secretase activity as ADAM10 and γ-secretase inhibitors blocked RAGE ligand-mediated cell migration. Together, our data suggest that proteolysis of RAGE is critical to mediate signaling and cell function and may therefore emerge as a novel therapeutic target for RAGE-dependent disease states. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Left ventricular systolic function in sickle cell anaemia: an ...

    African Journals Online (AJOL)

    Keywords: Left ventricular systolic function, sickle cell anaemia, echocardiographic evaluation, adult Nigerian patients. ..... Quadratic .505. -0.390. 12.231. 8.587 .001*. Cubic .510. -0.180. 8.264. 8.619 .001*. This relationship was further evaluated by means of scat- ter plots and subsequently by regression analysis. The.

  14. Liver Function In Patients With Homozygous Sickle Cell Disease ...

    African Journals Online (AJOL)

    Using the sensitive ELISA technique, 213 patients with sickle cell anemia (112 males and 101 females) aged 6 months to 18 years were screened for Hepatitis B infection using Hepatitis B surface antigen (HBsAg) and antibody to Hepatitis B core antigen. A biochemical evaluation of liver function was carried out on all ...

  15. Lifelong dietary intervention does not affect hematopoietic stem cell function

    NARCIS (Netherlands)

    Lazare, Seka; Ausema, Albertina; Reijne, Aaffien C; van Dijk, Gertjan; van Os, Ronald; de Haan, Gerald

    Hematopoietic stem cells (HSCs) undergo a profound functional decline during normal aging. Because caloric or dietary restriction has been shown to delay multiple aspects of the aging process in many species, we explored the consequences of lifelong caloric restriction, or conversely, lifelong

  16. Reduced fetal androgen exposure compromises Leydig cell function in adulthood

    NARCIS (Netherlands)

    Teerds, K.J.; Keijer, J.

    2015-01-01

    Disruption of normal fetal development can influence functioning of organs and cells in adulthood. Circumstantial evidence suggests that subtle reductions in fetal androgen production may be the cause of adult male reproductive disorders due to reduced testosterone production. The mechanisms through

  17. DNA-Damage-Induced Type I Interferon Promotes Senescence and Inhibits Stem Cell Function

    Directory of Open Access Journals (Sweden)

    Qiujing Yu

    2015-05-01

    Full Text Available Expression of type I interferons (IFNs can be induced by DNA-damaging agents, but the mechanisms and significance of this regulation are not completely understood. We found that the transcription factor IRF3, activated in an ATM-IKKα/β-dependent manner, stimulates cell-autonomous IFN-β expression in response to double-stranded DNA breaks. Cells and tissues with accumulating DNA damage produce endogenous IFN-β and stimulate IFN signaling in vitro and in vivo. In turn, IFN acts to amplify DNA-damage responses, activate the p53 pathway, promote senescence, and inhibit stem cell function in response to telomere shortening. Inactivation of the IFN pathway abrogates the development of diverse progeric phenotypes and extends the lifespan of Terc knockout mice. These data identify DNA-damage-response-induced IFN signaling as a critical mechanism that links accumulating DNA damage with senescence and premature aging.

  18. Two-Phase Iteration for Value Function Approximation and Hyperparameter Optimization in Gaussian-Kernel-Based Adaptive Critic Design

    Directory of Open Access Journals (Sweden)

    Xin Chen

    2015-01-01

    Full Text Available Adaptive Dynamic Programming (ADP with critic-actor architecture is an effective way to perform online learning control. To avoid the subjectivity in the design of a neural network that serves as a critic network, kernel-based adaptive critic design (ACD was developed recently. There are two essential issues for a static kernel-based model: how to determine proper hyperparameters in advance and how to select right samples to describe the value function. They all rely on the assessment of sample values. Based on the theoretical analysis, this paper presents a two-phase simultaneous learning method for a Gaussian-kernel-based critic network. It is able to estimate the values of samples without infinitively revisiting them. And the hyperparameters of the kernel model are optimized simultaneously. Based on the estimated sample values, the sample set can be refined by adding alternatives or deleting redundances. Combining this critic design with actor network, we present a Gaussian-kernel-based Adaptive Dynamic Programming (GK-ADP approach. Simulations are used to verify its feasibility, particularly the necessity of two-phase learning, the convergence characteristics, and the improvement of the system performance by using a varying sample set.

  19. Tachykinins and hematopoietic stem cell functions: implications in clinical disorders and tissue regeneration.

    Science.gov (United States)

    Murthy, Raghav G; Reddy, Bobby Y; Ruggiero, Jaclyn E; Rameshwar, Pranela

    2007-05-01

    Hematopoiesis is the process by which a limited number of hematopoietic stem cells (HSCs) maintain a functioning blood and immune system. In adults, hematopoiesis occurs in bone marrow and is supported by the microenvironment. The tachykinin family of peptides regulates hematopoiesis. Tachykinins can be released in bone marrow as neurotransmitters from innervating fibers, and from resident bone marrow cells. The hematopoietic effects by tachykinins involve four tachykinin genes, Tac1-Tac4. The latter is the most recently discovered member and encodes hemokinin-1, endokinin A, endokinin B, and two orphan peptides, endokinin C, and endokinin D. The alteration of normal hematopoietic functions by the tachykinins may result in the development of various pathologies. For example, Tac1 is involved in myelofibrosis and in leukemia, both of which are dysfunction of hematopoietic stem cells. A comprehensive understanding of dysfunctions caused by the tachykinins requires further research since other cells, such as stromal cells and factors including cytokines, chemokines, and endopeptidases, are involved in a network in which the tachykinins have critical roles. Studies into the properties and functions of tachykinins, the biology of their receptors, and related molecules would provide insights into the development of aging disorders, hematopoiesis, other dysfunction, and may also lead to the discovery of novel and effective clinical therapies. Controversies on applications for hematopoietic stem cells in regenerative medicine are discussed. Despite these controversies, a detailed understanding on how the bone marrow microenvironment maintains pluripotency of hematopoietic stem cells would be useful to manipulate the system to acquire specialized cells for tissue repair.

  20. Evolutionary cell biology: functional insight from "endless forms most beautiful".

    Science.gov (United States)

    Richardson, Elisabeth; Zerr, Kelly; Tsaousis, Anastasios; Dorrell, Richard G; Dacks, Joel B

    2015-12-15

    In animal and fungal model organisms, the complexities of cell biology have been analyzed in exquisite detail and much is known about how these organisms function at the cellular level. However, the model organisms cell biologists generally use include only a tiny fraction of the true diversity of eukaryotic cellular forms. The divergent cellular processes observed in these more distant lineages are still largely unknown in the general scientific community. Despite the relative obscurity of these organisms, comparative studies of them across eukaryotic diversity have had profound implications for our understanding of fundamental cell biology in all species and have revealed the evolution and origins of previously observed cellular processes. In this Perspective, we will discuss the complexity of cell biology found across the eukaryotic tree, and three specific examples of where studies of divergent cell biology have altered our understanding of key functional aspects of mitochondria, plastids, and membrane trafficking. © 2015 Richardson et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  1. Generation of functional podocytes from human induced pluripotent stem cells

    Directory of Open Access Journals (Sweden)

    Osele Ciampi

    2016-07-01

    Full Text Available Generating human podocytes in vitro could offer a unique opportunity to study human diseases. Here, we describe a simple and efficient protocol for obtaining functional podocytes in vitro from human induced pluripotent stem cells. Cells were exposed to a three-step protocol, which induced their differentiation into intermediate mesoderm, then into nephron progenitors and, finally, into mature podocytes. After differentiation, cells expressed the main podocyte markers, such as synaptopodin, WT1, α-Actinin-4, P-cadherin and nephrin at the protein and mRNA level, and showed the low proliferation rate typical of mature podocytes. Exposure to Angiotensin II significantly decreased the expression of podocyte genes and cells underwent cytoskeleton rearrangement. Cells were able to internalize albumin and self-assembled into chimeric 3D structures in combination with dissociated embryonic mouse kidney cells. Overall, these findings demonstrate the establishment of a robust protocol that, mimicking developmental stages, makes it possible to derive functional podocytes in vitro.

  2. Generation of functional podocytes from human induced pluripotent stem cells.

    Science.gov (United States)

    Ciampi, Osele; Iacone, Roberto; Longaretti, Lorena; Benedetti, Valentina; Graf, Martin; Magnone, Maria Chiara; Patsch, Christoph; Xinaris, Christodoulos; Remuzzi, Giuseppe; Benigni, Ariela; Tomasoni, Susanna

    2016-07-01

    Generating human podocytes in vitro could offer a unique opportunity to study human diseases. Here, we describe a simple and efficient protocol for obtaining functional podocytes in vitro from human induced pluripotent stem cells. Cells were exposed to a three-step protocol, which induced their differentiation into intermediate mesoderm, then into nephron progenitors and, finally, into mature podocytes. After differentiation, cells expressed the main podocyte markers, such as synaptopodin, WT1, α-Actinin-4, P-cadherin and nephrin at the protein and mRNA level, and showed the low proliferation rate typical of mature podocytes. Exposure to Angiotensin II significantly decreased the expression of podocyte genes and cells underwent cytoskeleton rearrangement. Cells were able to internalize albumin and self-assembled into chimeric 3D structures in combination with dissociated embryonic mouse kidney cells. Overall, these findings demonstrate the establishment of a robust protocol that, mimicking developmental stages, makes it possible to derive functional podocytes in vitro. Copyright © 2016. Published by Elsevier B.V.

  3. Functional Compartmentalization within Starburst Amacrine Cell Dendrites in the Retina

    Directory of Open Access Journals (Sweden)

    Alon Poleg-Polsky

    2018-03-01

    Full Text Available Summary: Dendrites in many neurons actively compute information. In retinal starburst amacrine cells, transformations from synaptic input to output occur within individual dendrites and mediate direction selectivity, but directional signal fidelity at individual synaptic outputs and correlated activity among neighboring outputs on starburst dendrites have not been examined systematically. Here, we record visually evoked calcium signals simultaneously at many individual synaptic outputs within single starburst amacrine cells in mouse retina. We measure visual receptive fields of individual output synapses and show that small groups of outputs are functionally compartmentalized within starburst dendrites, creating distinct computational units. Inhibition enhances compartmentalization and directional tuning of individual outputs but also decreases the signal-to-noise ratio. Simulations suggest, however, that the noise underlying output signal variability is well tolerated by postsynaptic direction-selective ganglion cells, which integrate convergent inputs to acquire reliable directional information. : Poleg-Polsky et al. examine the directional signaling fidelity of individual synapses on starburst amacrine cell dendrites. They identify functionally and morphologically distinct signaling compartments within SAC dendrites and show that inhibition enhances reliable decoding by postsynaptic direction-selective ganglion cells. Keywords: retina, synaptic transmission, amacrine cell, correlation, visual processing, inhibition, direction selectivity

  4. Functional somatostatin receptors on a rat pancreatic acinar cell line

    International Nuclear Information System (INIS)

    Viguerie, N.; Tahiri-Jouti, N.; Esteve, J.P.; Clerc, P.; Logsdon, C.; Svoboda, M.; Susini, C.; Vaysse, N.; Ribet, A.

    1988-01-01

    Somatostatin receptors from a rat pancreatic acinar cell line, AR4-2J, were characterized biochemically, structurally, and functionally. Binding of 125 I-[Tyr 11 ]Somatostatin to AR4-2J cells was saturable, exhibiting a single class of high-affinity binding sites with a maximal binding capacity of 258 ± 20 fmol/10 6 cells. Somatostatin receptor structure was analyzed by covalently cross-linking 125 I-[Tyr 11 ]somatostatin to its plasma membrane receptors. Gel electrophoresis and autoradiography of cross-linked proteins revealed a peptide containing the somatostatin receptor. Somatostatin inhibited vasoactive intestinal peptide (VIP)-stimulated adenosine 3',5'-cyclic monophosphate (cAMP) formation in a dose-dependent manner. The concentration of somatostatin that caused half-maximal inhibition of cAMP formation was close to the receptor affinity for somatostatin. Pertussis toxin pretreatment of AR4-2J cells prevented somatostatin inhibition of VIP-stimulated cAMP formation as well as somatostatin binding. The authors conclude that AR4-2J cells exhibit functional somatostatin receptors that retain both specificity and affinity of the pancreatic acinar cell somatostatin receptors and act via the pertussis toxin-sensitive guanine nucleotide-binding protein N i to inhibit adenylate cyclase

  5. Triazole fungicide tebuconazole disrupts human placental trophoblast cell functions.

    Science.gov (United States)

    Zhou, Jinghua; Zhang, Jianyun; Li, Feixue; Liu, Jing

    2016-05-05

    Triazole fungicides are one of the top ten classes of current-use pesticides. Although exposure to triazole fungicides is associated with reproductive toxicity in mammals, limited information is available regarding the effects of triazole fungicides on human placental trophoblast function. Tebuconazole (TEB) is a common triazole fungicide that has been extensively used for fungi control. In this work, we showed that TEB could reduce cell viability, disturb normal cell cycle distribution and induce apoptosis of human placental trophoblast cell line HTR-8/SVneo (HTR-8). Bcl-2 protein expression decreased and the level of Bax protein increased after TEB treatment in HTR-8 cells. The results demonstrated that this fungicide induced apoptosis of trophoblast cells via mitochondrial pathway. Importantly, we found that the invasive and migratory capacities of HTR-8 cells decreased significantly after TEB administration. TEB altered the expression of key regulatory genes involved in the modulation of trophoblast functions. Taken together, TEB suppressed human trophoblast invasion and migration through affecting the expression of protease, hormones, angiogenic factors, growth factors and cytokines. As the invasive and migratory abilities of trophoblast are essential for successful placentation and fetus development, our findings suggest a potential risk of triazole fungicides to human pregnancy. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Genetic and Epigenetic Mechanisms That Maintain Hematopoietic Stem Cell Function

    Directory of Open Access Journals (Sweden)

    Christian Kosan

    2016-01-01

    Full Text Available All hematopoiesis cells develop from multipotent progenitor cells. Hematopoietic stem cells (HSC have the ability to develop into all blood lineages but also maintain their stemness. Different molecular mechanisms have been identified that are crucial for regulating quiescence and self-renewal to maintain the stem cell pool and for inducing proliferation and lineage differentiation. The stem cell niche provides the microenvironment to keep HSC in a quiescent state. Furthermore, several transcription factors and epigenetic modifiers are involved in this process. These create modifications that regulate the cell fate in a more or less reversible and dynamic way and contribute to HSC homeostasis. In addition, HSC respond in a unique way to DNA damage. These mechanisms also contribute to the regulation of HSC function and are essential to ensure viability after DNA damage. How HSC maintain their quiescent stage during the entire life is still matter of ongoing research. Here we will focus on the molecular mechanisms that regulate HSC function.

  7. The Ror1 receptor tyrosine kinase plays a critical role in regulating satellite cell proliferation during regeneration of injured muscle.

    Science.gov (United States)

    Kamizaki, Koki; Doi, Ryosuke; Hayashi, Makoto; Saji, Takeshi; Kanagawa, Motoi; Toda, Tatsushi; Fukada, So-Ichiro; Ho, Hsin-Yi Henry; Greenberg, Michael Eldon; Endo, Mitsuharu; Minami, Yasuhiro

    2017-09-22

    The Ror family receptor tyrosine kinases, Ror1 and Ror2, play important roles in regulating developmental morphogenesis and tissue- and organogenesis, but their roles in tissue regeneration in adult animals remain largely unknown. In this study, we examined the expression and function of Ror1 and Ror2 during skeletal muscle regeneration. Using an in vivo skeletal muscle injury model, we show that expression of Ror1 and Ror2 in skeletal muscles is induced transiently by the inflammatory cytokines, TNF-α and IL-1β, after injury and that inhibition of TNF-α and IL-1β by neutralizing antibodies suppresses expression of Ror1 and Ror2 in injured muscles. Importantly, expression of Ror1 , but not Ror2 , was induced primarily in Pax7-positive satellite cells (SCs) after muscle injury, and administration of neutralizing antibodies decreased the proportion of Pax7-positive proliferative SCs after muscle injury. We also found that stimulation of a mouse myogenic cell line, C2C12 cells, with TNF-α or IL-1β induced expression of Ror1 via NF-κB activation and that suppressed expression of Ror1 inhibited their proliferative responses in SCs. Intriguingly, SC-specific depletion of Ror1 decreased the number of Pax7-positive SCs after muscle injury. Collectively, these findings indicate for the first time that Ror1 has a critical role in regulating SC proliferation during skeletal muscle regeneration. We conclude that Ror1 might be a suitable target in the development of diagnostic and therapeutic approaches to manage muscular disorders. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. KLF2 in Regulation of NF-κB-Mediated Immune Cell Function and Inflammation

    Directory of Open Access Journals (Sweden)

    Prerana Jha

    2017-11-01

    Full Text Available KLF2 (Kruppel-like factor 2 is a member of the zinc finger transcription factor family, which critically regulates embryonic lung development, function of endothelial cells and maintenance of quiescence in T-cells and monocytes. It is expressed in naïve T-cells and monocytes, however its level of expression decreases during activation and differentiation. KLF2 also plays critical regulatory role in various inflammatory diseases and their pathogenesis. Nuclear factor-kappaB (NF-κB is an important inducer of inflammation and the inflammation is mediated through the transcription of several proinflammatory cytokines, chemokines and adhesion molecules. So, both transcriptional factors KLF2 and NF-κB are being associated with the similar cellular functions and their maintenance. It was shown that KLF2 regulates most of the NF-κB-mediated activities. In this review, we focused on emphasizing the involvement of KLF2 in health and disease states and how they interact with transcriptional master regulator NF-κB.

  9. Aryl Hydrocarbon Receptor Activation Reduces Dendritic Cell Function during Influenza Virus Infection

    Science.gov (United States)

    Jin, Guang-Bi; Moore, Amanda J.; Head, Jennifer L.; Neumiller, Joshua J.; Lawrence, B. Paige

    2010-01-01

    It has long been known that activation of the aryl hydrocarbon receptor (AhR) by ligands such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) suppresses T cell–dependent immune responses; however, the underlying cellular targets and mechanism remain unclear. We have previously shown that AhR activation by TCDD reduces the proliferation and differentiation of influenza virus–specific CD8+ T cells through an indirect mechanism; suggesting that accessory cells are critical AhR targets during infection. Respiratory dendritic cells (DCs) capture antigen, migrate to lymph nodes, and play a key role in activating naive CD8+ T cells during respiratory virus infection. Herein, we report an examination of how AhR activation alters DCs in the lung and affects their trafficking to and function in the mediastinal lymph nodes (MLN) during infection with influenza virus. We show that AhR activation impairs lung DC migration and reduces the ability of DCs isolated from the MLN to activate naive CD8+ T cells. Using novel AhR mutant mice, in which the AhR protein lacks its DNA-binding domain, we show that the suppressive effects of TCDD require that the activated AhR complex binds to DNA. These new findings suggest that AhR activation by chemicals from our environment impacts DC function to stimulate naive CD8+ T cells and that immunoregulatory genes within DCs are critical targets of AhR. Moreover, our results reinforce the idea that environmental signals and AhR ligands may contribute to differential susceptibilities and responses to respiratory infection. PMID:20498003

  10. Functional, communicative and critical health literacy of chronic disease patients and their importance for self-management.

    OpenAIRE

    Heijmans, M.; Waverijn, G.; Rademakers, J.; Vaart, R. van der; Rijken, M.

    2015-01-01

    Objective: To provide insight into the level of health literacy among chronic disease patients in the Netherlands, to identify subgroups with low literacy and to examine the associations between health literacy and self-management. Methods: Self-report questionnaires were sent to a nationwide sample of 1.341 chronic disease patients. The Dutch Functional Communicative and Critical Health Literacy scale (FCCHL), the Partners in Health scale (PIH) and Perceived Efficacy in Patient–Doctor Intera...

  11. Fatty Acids, Lipid Mediators, and T-Cell Function

    Science.gov (United States)

    de Jong, Anja J.; Kloppenburg, Margreet; Toes, René E. M.; Ioan-Facsinay, Andreea

    2014-01-01

    Research toward the mechanisms underlying obesity-linked complications has intensified during the last years. As a consequence, it has become clear that metabolism and immunity are intimately linked. Free fatty acids and other lipids acquired in excess by current feeding patterns have been proposed to mediate this link due to their immune modulatory capacity. The functional differences between saturated and unsaturated fatty acids, in combination with their dietary intake are believed to modulate the outcome of immune responses. Moreover, unsaturated fatty acids can be oxidized in a tightly regulated and specific manner to generate either potent pro-inflammatory or pro-resolving lipid mediators. These oxidative derivatives of fatty acids have received detailed attention during the last years, as they have proven to have strong immune modulatory capacity, even in pM ranges. Both fatty acids and oxidized fatty acids have been studied especially in relation to macrophage and T-cells functions. In this review, we propose to focus on the effect of fatty acids and their oxidative derivatives on T-cells, as it is an active area of research during the past 5 years. The effect of fatty acids and their derivatives on activation and proliferation of T-cells, as well as the delicate balance between stimulation and lipotoxicity will be discussed. Moreover, the receptors involved in the interaction between free fatty acids and their derivatives with T-cells will be summarized. Finally, the mechanisms involved in modulation of T-cells by fatty acids will be addressed, including cellular signaling and metabolism of T-cells. The in vitro results will be placed in context of in vivo studies both in humans and mice. In this review, we summarize the latest findings on the immune modulatory function of lipids on T-cells and will point out novel directions for future research. PMID:25352844

  12. Syndecans – key regulators of cell signaling and biological functions

    DEFF Research Database (Denmark)

    Afratis, Nikolaos A.; Nikitovic, Dragana; Multhaupt, Hinke A.B.

    2017-01-01

    molecules during cancer initiation and progression. Particularly syndecans interact with other cell surface receptors, such as growth factor receptors and integrins, which lead to activation of downstream signaling pathways, which are critical for the cellular behavior. Moreover, this review describes...... has been established, which has consequences for the regulation of cell adhesion and migration. Specifically, ecto- and cytoplasmic domains are responsible for the interaction with extracellular matrix molecules and intracellular kinases, respectively. These interactions indicate syndecans as key...... the key role of syndecans in intracellular calcium regulation and homeostasis. The syndecan-mediated regulation of calcium metabolism is highly correlated with cells’ adhesion phenotype through the actin cytoskeleton and formation of junctions, with implications during differentiation and disease...

  13. The Functions of Type I and Type II Natural Killer T (NKT) Cells in Inflammatory Bowel Diseases

    Science.gov (United States)

    Liao, Chia-Min; Zimmer, Michael I.; Wang, Chyung-Ru

    2013-01-01

    CD1d-restricted natural killer T (NKT) cells are a distinct subset of T cells that rapidly produce an array of cytokines upon activation and play a critical role in regulating various immune responses. NKT cells are classified into two groups based on differences in T cell receptor (TCR) usage. Type I NKT cells have an invariant TCRα-chain and are readily detectable by α-galactosylceramide (α-GalCer)-loaded CD1d tetramers. Type II NKT cells have a more diverse TCR repertoire and cannot be directly identified. Both types of NKT cells as well as multiple CD1d-expressing cell types are present in the intestine and their interactions are likely to be modulated by pathogenic and commensal microbes, which in turn contribute to the intestinal immune responses in health and disease. Indeed, in several animal models of inflammatory bowel disease (IBD), Type I NKT cells have been shown to make both protective and pathogenic contributions to disease. In contrast, in human patients suffering from ulcerative colitis (UC), and a mouse model in which both CD1d expression and the frequency of Type II NKT cells are increased, Type II NKT cells appear to promote intestinal inflammation. In this review, we summarize present knowledge on the antigen recognition, activation and function of NKT cells with a particular focus on their role in IBD, and discuss factors that may influence the functional outcome of NKT cell responses in intestinal inflammation. PMID:23518808

  14. Functional differentiation of midbrain neurons from human cord blood-derived induced pluripotent stem cells.

    Science.gov (United States)

    Stanslowsky, Nancy; Haase, Alexandra; Martin, Ulrich; Naujock, Maximilian; Leffler, Andreas; Dengler, Reinhard; Wegner, Florian

    2014-03-17

    Human induced pluripotent stem cells (hiPSCs) offer great promise for regenerative therapies or in vitro modelling of neurodegenerative disorders like Parkinson's disease. Currently, widely used cell sources for the generation of hiPSCs are somatic cells obtained from aged individuals. However, a critical issue concerning the potential clinical use of these iPSCs is mutations that accumulate over lifetime and are transferred onto iPSCs during reprogramming which may influence the functionality of cells differentiated from them. The aim of our study was to establish a differentiation strategy to efficiently generate neurons including dopaminergic cells from human cord blood-derived iPSCs (hCBiPSCs) as a juvenescent cell source and prove their functional maturation in vitro. The differentiation of hCBiPSCs was initiated by inhibition of transforming growth factor-β and bone morphogenetic protein signaling using the small molecules dorsomorphin and SB 431542 before final maturation was carried out. hCBiPSCs and differentiated neurons were characterized by immunocytochemistry and quantitative real time-polymerase chain reaction. Since functional investigations of hCBiPSC-derived neurons are indispensable prior to clinical applications, we performed detailed analysis of essential ion channel properties using whole-cell patch-clamp recordings and calcium imaging. A Sox1 and Pax6 positive neuronal progenitor cell population was efficiently induced from hCBiPSCs using a newly established differentiation protocol. Neuronal progenitor cells could be further maturated into dopaminergic neurons expressing tyrosine hydroxylase, the dopamine transporter and engrailed 1. Differentiated hCBiPSCs exhibited voltage-gated ion currents, were able to fire action potentials and displayed synaptic activity indicating synapse formation. Application of the neurotransmitters GABA, glutamate and acetylcholine induced depolarizing calcium signal changes in neuronal cells providing evidence

  15. Syntenin mediates SRC function in exosomal cell-to-cell communication.

    Science.gov (United States)

    Imjeti, Naga Sailaja; Menck, Kerstin; Egea-Jimenez, Antonio Luis; Lecointre, Celine; Lembo, Frederique; Bouguenina, Habib; Badache, Ali; Ghossoub, Rania; David, Guido; Roche, Serge; Zimmermann, Pascale

    2017-11-21

    The cytoplasmic tyrosine kinase SRC controls cell growth, proliferation, adhesion, and motility. The current view is that SRC acts primarily downstream of cell-surface receptors to control intracellular signaling cascades. Here we reveal that SRC functions in cell-to-cell communication by controlling the biogenesis and the activity of exosomes. Exosomes are viral-like particles from endosomal origin that can reprogram recipient cells. By gain- and loss-of-function studies, we establish that SRC stimulates the secretion of exosomes having promigratory activity on endothelial cells and that syntenin is mandatory for SRC exosomal function. Mechanistically, SRC impacts on syndecan endocytosis and on syntenin-syndecan endosomal budding, upstream of ARF6 small GTPase and its effector phospholipase D2, directly phosphorylating the conserved juxtamembrane DEGSY motif of the syndecan cytosolic domain and syntenin tyrosine 46. Our study uncovers a function of SRC in cell-cell communication, supported by syntenin exosomes, which is likely to contribute to tumor-host interactions. Copyright © 2017 the Author(s). Published by PNAS.

  16. Methods to Study Epithelial Transport Protein Function and Expression in Native Intestine and Caco-2 Cells Grown in 3D.

    Science.gov (United States)

    Anabazhagan, Arivarasu N; Chatterjee, Ishita; Priyamvada, Shubha; Kumar, Anoop; Tyagi, Sangeeta; Saksena, Seema; Alrefai, Waddah A; Dudeja, Pradeep K; Gill, Ravinder K

    2017-03-16

    The intestinal epithelium has important transport and barrier functions that play key roles in normal physiological functions of the body while providing a barrier to foreign particles. Impaired epithelial transport (ion, nutrient, or drugs) has been associated with many diseases and can have consequences that extend beyond the normal physiological functions of the transporters, such as by influencing epithelial integrity and the gut microbiome. Understanding the function and regulation of transport proteins is critical for the development of improved therapeutic interventions. The biggest challenge in the study of epithelial transport is developing a suitable model system that recapitulates important features of the native intestinal epithelial cells. Several in vitro cell culture models, such as Caco-2, T-84, and HT-29-Cl.19A cells are typically used in epithelial transport research. These cell lines represent a reductionist approach to modeling the epithelium and have been used in many mechanistic studies, including their examination of epithelial-microbial interactions. However, cell monolayers do not accurately reflect cell-cell interactions and the in vivo microenvironment. Cells grown in 3D have shown to be promising models for drug permeability studies. We show that Caco-2 cells in 3D can be used to study epithelial transporters. It is also important that studies in Caco-2 cells are complemented with other models to rule out cell specific effects and to take into account the complexity of the native intestine. Several methods have been previously used to assess the functionality of transporters, such as everted sac and uptake in isolated epithelial cells or in isolated plasma membrane vesicles. Taking into consideration the challenges in the field with respect to models and the measurement of transport function, we demonstrate here a protocol to grow Caco-2 cells in 3D and describe the use of an Ussing chamber as an effective approach to measure serotonin

  17. A critical appraisal of ibrutinib in the treatment of mantle cell lymphoma and chronic lymphocytic leukemia

    Directory of Open Access Journals (Sweden)

    Tucker DL

    2015-06-01

    Full Text Available David L Tucker, Simon A Rule Department of Haematology, Plymouth Hospitals NHS Trust, Plymouth, UK Abstract: Although chemo-immunotherapy remains at the forefront of first-line treatment for mantle cell lymphoma (MCL and chronic lymphocytic leukemia (CLL, small molecules, such as ibrutinib, are beginning to play a significant role, particularly in patients with multiply relapsed or chemotherapy-refractory disease and where toxicity is an overriding concern. Ibrutinib is a first-in-class, oral inhibitor of Bruton’s tyrosine kinase, which functions by irreversible inhibition of the downstream signaling pathway of the B-cell receptor, which normally promotes cell survival and proliferation. Early clinical trials have demonstrated excellent tolerability and a modest side-effect profile even in elderly and multiply pretreated patient cohorts. Although the majority of disease responses tend to be partial, efficacy data have also been encouraging with more than two-thirds of patients with CLL and MCL demonstrating a durable response, even in the high-risk disease setting. Resistance mechanisms are only partially understood and appear to be multifactorial, including the binding site mutation C481S, and escape through other common cell-signaling pathways. This article appraises the currently available data on safety and efficacy from clinical trials of ibrutinib in the management of MCL and CLL, both as a single agent and in combination with other therapies, and considers how this drug is likely to be used in future clinical practice. Keywords: ibrutinib, mantle cell lymphoma, chronic lymphocytic leukemia, Bruton’s tyrosine kinase, lymphoproliferative disorders

  18. Cell Adhesion Molecules and Ubiquitination—Functions and Significance

    Science.gov (United States)

    Homrich, Mirka; Gotthard, Ingo; Wobst, Hilke; Diestel, Simone

    2015-01-01

    Cell adhesion molecules of the immunoglobulin (Ig) superfamily represent the biggest group of cell adhesion molecules. They have been analyzed since approximately 40 years ago and most of them have been shown to play a role in tumor progression and in the nervous system. All members of the Ig superfamily are intensively posttranslationally modified. However, many aspects of their cellular functions are not yet known. Since a few years ago it is known that some of the Ig superfamily members are modified by ubiquitin. Ubiquitination has classically been described as a proteasomal degradation signal but during the last years it became obvious that it can regulate many other processes including internalization of cell surface molecules and lysosomal sorting. The purpose of this review is to summarize the current knowledge about the ubiquitination of cell adhesion molecules of the Ig superfamily and to discuss its potential physiological roles in tumorigenesis and in the nervous system. PMID:26703751

  19. Modulation of antigen presenting cell functions during chronic HPV infection

    Directory of Open Access Journals (Sweden)

    Abate Assefa Bashaw

    2017-12-01

    Full Text Available High-risk human papillomaviruses (HR-HPV infect basal keratinocytes, where in some individuals they evade host immune responses and persist. Persistent HR-HPV infection of the cervix causes precancerous neoplasia that can eventuate in cervical cancer. Dendritic cells (DCs are efficient in priming/cross-priming antigen-specific T cells and generating antiviral and antitumor cytotoxic CD8+ T cells. However, HR-HPV have adopted various immunosuppressive strategies, with modulation of DC function crucial to escape from the host adaptive immune response. HPV E6 and E7 oncoproteins alter recruitment and localization of epidermal DCs, while soluble regulatory factors derived from HPV-induced hyperplastic epithelium change DC development and influence initiation of specific cellular immune responses. This review focuses on current evidence for HR-HPV manipulation of antigen presentation in dendritic cells and escape from host immunity.

  20. Mesenchymal Stem Cell-Derived Factors Restore Function to Human Frataxin-Deficient Cells.

    Science.gov (United States)

    Kemp, Kevin; Dey, Rimi; Cook, Amelia; Scolding, Neil; Wilkins, Alastair

    2017-08-01

    Friedreich's ataxia is an inherited neurological disorder characterised by mitochondrial dysfunction and increased susceptibility to oxidative stress. At present, no therapy has been shown to reduce disease progression. Strategies being trialled to treat Friedreich's ataxia include drugs that improve mitochondrial function and reduce oxidative injury. In addition, stem cells have been investigated as a potential therapeutic approach. We have used siRNA-induced knockdown of frataxin in SH-SY5Y cells as an in vitro cellular model for Friedreich's ataxia. Knockdown of frataxin protein expression to levels detected in patients with the disorder was achieved, leading to decreased cellular viability, increased susceptibility to hydrogen peroxide-induced oxidative stress, dysregulation of key anti-oxidant molecules and deficiencies in both cell proliferation and differentiation. Bone marrow stem cells are being investigated extensively as potential treatments for a wide range of neurological disorders, including Friedreich's ataxia. The potential neuroprotective effects of bone marrow-derived mesenchymal stem cells were therefore studied using our frataxin-deficient cell model. Soluble factors secreted by mesenchymal stem cells protected against cellular changes induced by frataxin deficiency, leading to restoration in frataxin levels and anti-oxidant defences, improved survival against oxidative stress and stimulated both cell proliferation and differentiation down the Schwann cell lineage. The demonstration that mesenchymal stem cell-derived factors can restore cellular homeostasis and function to frataxin-deficient cells further suggests that they may have potential therapeutic benefits for patients with Friedreich's ataxia.

  1. Critical Role for CD103(+)/CD141(+) Dendritic Cells Bearing CCR7 for Tumor Antigen Trafficking and Priming of T Cell Immunity in Melanoma.

    Science.gov (United States)

    Roberts, Edward W; Broz, Miranda L; Binnewies, Mikhail; Headley, Mark B; Nelson, Amanda E; Wolf, Denise M; Kaisho, Tsuneyasu; Bogunovic, Dusan; Bhardwaj, Nina; Krummel, Matthew F

    2016-08-08

    Intratumoral dendritic cells (DC) bearing CD103 in mice or CD141 in humans drive intratumoral CD8(+) T cell activation. Using multiple strategies, we identified a critical role for these DC in trafficking tumor antigen to lymph nodes (LN), resulting in both direct CD8(+) T cell stimulation and antigen hand-off to resident myeloid cells. These effects all required CCR7. Live imaging demonstrated direct presentation to T cells in LN, and CCR7 loss specifically in these cells resulted in defective LN T cell priming and increased tumor outgrowth. CCR7 expression levels in human tumors correlate with signatures of CD141(+) DC, intratumoral T cells, and better clinical outcomes. This work identifies an ongoing pathway to T cell priming, which should be harnessed for tumor therapies. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. TRAF6 regulates satellite stem cell self-renewal and function during regenerative myogenesis

    Science.gov (United States)

    Hindi, Sajedah M.; Kumar, Ashok

    2015-01-01

    Satellite cells are a stem cell population within adult muscle and are responsible for myofiber regeneration upon injury. Satellite cell dysfunction has been shown to underlie the loss of skeletal muscle mass in many acquired and genetic muscle disorders. The transcription factor paired box-protein-7 (PAX7) is indispensable for supplementing the reservoir of satellite cells and driving regeneration in normal and diseased muscle. TNF receptor–associated factor 6 (TRAF6) is an adaptor protein and an E3 ubiquitin ligase that mediates the activation of multiple cell signaling pathways in a context-dependent manner. Here, we demonstrated that TRAF6-mediated signaling is critical for homeostasis of satellite cells and their function during regenerative myogenesis. Selective deletion of Traf6 in satellite cells of adult mice led to profound muscle regeneration defects and dramatically reduced levels of PAX7 and late myogenesis markers. TRAF6 was required for the activation of MAPKs ERK1/2 and JNK1/2, which in turn activated the transcription factor c-JUN, which binds the Pax7 promoter and augments Pax7 expression. Moreover, TRAF6/c-JUN signaling repressed the levels of the microRNAs miR-1 and miR-206, which promote differentiation, to maintain PAX7 levels in satellite cells. We also determined that satellite cell–specific deletion of Traf6 exaggerates the dystrophic phenotype in the mdx (a mouse model of Duchenne muscular dystrophy) mouse by blunting the regeneration of injured myofibers. Collectively, our study reveals an essential role for TRAF6 in satellite stem cell function. PMID:26619121

  3. Pathogenesis of RON receptor tyrosine kinase in cancer cells: activation mechanism, functional crosstalk, and signaling addiction.

    Science.gov (United States)

    Wang, Ming-Hai; Zhang, Ruiwen; Zhou, Yong-Qing; Yao, Hang-Ping

    2013-09-01

    The RON receptor tyrosine kinase, a member of the MET proto-oncogene family, is a pathogenic factor implicated in tumor malignancy. Specifically, aberrations in RON signaling result in increased cancer cell growth, survival, invasion, angiogenesis, and drug resistance. Biochemical events such as ligand binding, receptor overexpression, generation of structure-defected variants, and point mutations in the kinase domain contribute to RON signaling activation. Recently, functional crosstalk between RON and signaling proteins such as MET and EFGR has emerged as an additional mechanism for RON activation, which is critical for tumorigenic development. The RON signaling crosstalk acts either as a regulatory feedback loop that strengthens or enhances tumorigenic phenotype of cancer cells or serves as a signaling compensatory pathway providing a growth/survival advantage for cancer cells to escape targeted therapy. Moreover, viral oncoproteins derived from Friend leukemia or Epstein-Barr viruses interact with RON to drive viral oncogenesis. In cancer cells, RON signaling is integrated into cellular signaling network essential for cancer cell growth and survival. These activities provide the molecular basis of targeting RON for cancer treatment. In this review, we will discuss recent data that uncover the mechanisms of RON activation in cancer cells, review evidence of RON signaling crosstalk relevant to cancer malignancy, and emphasize the significance of the RON signaling addiction by cancer cells for tumor therapy. Understanding aberrant RON signaling will not only provide insight into the mechanisms of tumor pathogenesis, but also lead to the development of novel strategies for molecularly targeted cancer treatment.

  4. Sickle cell disease biochip: a functional red blood cell adhesion assay for monitoring sickle cell disease

    Science.gov (United States)

    ALAPAN, YUNUS; KIM, CEONNE; ADHIKARI, ANIMA; GRAY, KAYLA E.; GURKAN-CAVUSOGLU, EVREN; LITTLE, JANE A.; GURKAN, UMUT A.

    2016-01-01

    Sickle cell disease (SCD) afflicts millions of people worldwide and is associated with considerable morbidity and mortality. Chronic and acute vaso-occlusion are the clinical hallmarks of SCD and can result in pain crisis, widespread organ damage, and early movtality. Even though the molecular underpinnings of SCD were identified more than 60 years ago, there are no molecular or biophysical markers of disease severity that are feasibly measured in the clinic. Abnormal cellular adhesion to vascular endothelium is at the root of vaso-occlusion. However, cellular adhesion is not currently evaluated clinically. Here, we present a clinically applicable microfluidic device (SCD biochip) that allows serial quantitative evaluation of red blood cell (RBC) adhesion to endothelium-associated protein-immobilized microchannels, in a closed and preprocessing-free system. With the SCD biochip, we have analyzed blood samples from more than 100 subjects and have shown associations between the measured RBC adhesion to endothelium-associated proteins (fibronectin and laminin) and individual RBC characteristics, including hemoglobin content, fetal hemoglobin concentration, plasma lactate dehydrogenase level, and reticulocyte count. The SCD biochip is a functional adhesion assay, reflecting quantitative evaluation of RBC adhesion, which could be used at baseline, during crises, relative to various long-term complications, and before and after therapeutic interventions. PMID:27063958

  5. Non-critical string theory formulation of microtubule dynamics and quantum aspects of brain function

    CERN Document Server

    Mavromatos, Nikolaos E

    1995-01-01

    Microtubule (MT) networks, subneural paracrystalline cytosceletal structures, seem to play a fundamental role in the neurons. We cast here the complicated MT dynamics in the form of a 1+1-dimensional non-critical string theory, thus enabling us to provide a consistent quantum treatment of MTs, including enviromental {\\em friction} effects. We suggest, thus, that the MTs are the microsites, in the brain, for the emergence of stable, macroscopic quantum coherent states, identifiable with the {\\em preconscious states}. Quantum space-time effects, as described by non-critical string theory, trigger then an {\\em organized collapse} of the coherent states down to a specific or {\\em conscious state}. The whole process we estimate to take {\\cal O}(1\\,{\\rm sec}), in excellent agreement with a plethora of experimental/observational findings. The {\\em microscopic arrow of time}, endemic in non-critical string theory, and apparent here in the self-collapse process, provides a satisfactory and simple resolution to the age...

  6. Critical role of SAP in progression and reactivation but not maintenance of T cell-dependent humoral immunity.

    Science.gov (United States)

    Zhong, Ming-Chao; Veillette, André

    2013-03-01

    Signaling lymphocytic activation molecule (SLAM)-associated protein (SAP) is a small adaptor molecule mutated in X-linked lymphoproliferative disease, a human immunodeficiency. SAP plays a critical role in the initiation of T cell-dependent B cell responses leading to germinal center reaction, the production of high-affinity antibodies, and B cell memory. However, whether SAP has a role in these responses beyond their initiation is not known. It is important to address this matter not only for mechanistic reasons but also because blockade of the SAP pathway is being contemplated as a means to treat autoimmune diseases in humans. Using an inducibly SAP deficient mouse, we found that SAP was required not only for the initiation but also for the progression of primary T cell-driven B cell responses to haptens. It was also necessary for the reactivation of T cell-dependent B cell immunity during secondary immune responses. These activities consistently correlated with the requirement of SAP for full expression of the lineage commitment factor Bcl-6 in follicular T helper (T(FH)) cells. However, once memory B cells and long-lived antibody-secreting cells were established, SAP became dispensable for maintaining T cell-dependent B cell responses. Thus, SAP is pivotal for nearly all phases, but not for maintenance, of T cell-driven B cell humoral immunity. These findings may have implications for the treatment of immune disorders by targeting the SAP pathway.

  7. Does Mindfulness Enhance Critical Thinking? Evidence for the Mediating Effects of Executive Functioning in the Relationship between Mindfulness and Critical Thinking

    OpenAIRE

    Noone, Chris; Bunting, Brendan; Hogan, Michael J.

    2016-01-01

    Mindfulness originated in the Buddhist tradition as a way of cultivating clarity of thought. Despite the fact that this behaviour is best captured using critical thinking assessments, no studies have examined the effects of mindfulness on critical thinking or the mechanisms underlying any such possible relationship. Even so, mindfulness has been suggested as being beneficial for critical thinking in higher education. Critical thinking is recognised as an important higher-order cognitive proce...

  8. Diacylglycerol Kinases: Regulated Controllers of T Cell Activation, Function, and Development

    Directory of Open Access Journals (Sweden)

    Gary A. Koretzky

    2013-03-01

    Full Text Available Diacylglycerol kinases (DGKs are a diverse family of enzymes that catalyze the conversion of diacylglycerol (DAG, a crucial second messenger of receptor-mediated signaling, to phosphatidic acid (PA. Both DAG and PA are bioactive molecules that regulate a wide set of intracellular signaling proteins involved in innate and adaptive immunity. Clear evidence points to a critical role for DGKs in modulating T cell activation, function, and development. More recently, studies have elucidated factors that control DGK function, suggesting an added complexity to how DGKs act during signaling. This review summarizes the available knowledge of the function and regulation of DGK isoforms in signal transduction with a particular focus on T lymphocytes.

  9. Tumor-altered dendritic cell function: implications for anti-tumor immunity

    Directory of Open Access Journals (Sweden)

    Kristian Michael Hargadon

    2013-07-01

    Full Text Available Dendritic cells are key regulators of both innate and adaptive immunity, and the array of immunoregulatory functions exhibited by these cells is dictated by their differentiation, maturation, and activation status. Although a major role for these cells in the induction of immunity to pathogens has long been appreciated, data accumulated over the last several years has demonstrated that DC are also critical regulators of anti-tumor immune responses. However, despite the potential for stimulation of robust anti-tumor immunity by DC, tumor-altered DC function has been observed in many cancer patients and tumor-bearing animals and is often associated with tumor immune escape. Such dysfunction has significant implications for both the induction of natural anti-tumor immune responses as well as the efficacy of immunotherapeutic strategies that target endogenous DC in situ or that employ exogenous DC as part of anti-cancer immunization maneuvers. In this review, the major types of tumor-altered DC function will be described, with emphasis on recent insights into the mechanistic bases for the inhibition of DC differentiation from hematopoietic precursors, the altered programming of DC precursors to differentiate into myeloid-derived suppressor cells or tumor-associated macrophages, the suppression of DC maturation and activation, and the induction of immunoregulatory DC by tumors, tumor-derived factors, and tumor-associated cells within the milieu of the tumor microenvironment. The impact of these tumor-altered cells on the quality of the overall anti-tumor immune response will also be discussed. Finally, this review will also highlight questions concerning tumor-altered DC function that remain unanswered, and it will address factors that have limited advances in the study of this phenomenon in order to focus future research efforts in the field on identifying strategies for interfering with tumor-associated DC dysfunction and improving DC-mediated anti

  10. Tumor-altered dendritic cell function: implications for anti-tumor immunity.

    Science.gov (United States)

    Hargadon, Kristian M

    2013-01-01

    Dendritic cells (DC) are key regulators of both innate and adaptive immunity, and the array of immunoregulatory functions exhibited by these cells is dictated by their differentiation, maturation, and activation status. Although a major role for these cells in the induction of immunity to pathogens has long been appreciated, data accumulated over the last several years has demonstrated that DC are also critical regulators of anti-tumor immune responses. However, despite the potential for stimulation of robust anti-tumor immunity by DC, tumor-altered DC function has been observed in many cancer patients and tumor-bearing animals and is often associated with tumor immune escape. Such dysfunction has significant implications for both the induction of natural anti-tumor immune responses as well as the efficacy of immunotherapeutic strategies that target endogenous DC in situ or that employ exogenous DC as part of anti-cancer immunization maneuvers. In this review, the major types of tumor-altered DC function will be described, with emphasis on recent insights into the mechanistic bases for the inhibition of DC differentiation from hematopoietic precursors, the altered programing of DC precursors to differentiate into myeloid-derived suppressor cells or tumor-associated macrophages, the suppression of DC maturation and activation, and the induction of immunoregulatory DC by tumors, tumor-derived factors, and tumor-associated cells within the milieu of the tumor microenvironment. The impact of these tumor-altered cells on the quality of the overall anti-tumor immune response will also be discussed. Finally, this review will also highlight questions concerning tumor-altered DC function that remain unanswered, and it will address factors that have limited advances in the study of this phenomenon in order to focus future research efforts in the field on identifying strategies for interfering with tumor-associated DC dysfunction and improving DC-mediated anti-tumor immunity.

  11. Amelioration of NK cell function driven by Vα24+ invariant NKT cell activation in multiple myeloma.

    Science.gov (United States)

    Iyoda, Tomonori; Yamasaki, Satoru; Hidaka, Michihiro; Kawano, Fumio; Abe, Yu; Suzuki, Kenshi; Kadowaki, Norimitsu; Shimizu, Kanako; Fujii, Shin-Ichiro

    2018-02-01

    NK cells represent a first line of immune defense, but are progressively dysregulated in multiple myeloma (MM) patients. To restore and facilitate their antitumor effect, NK cells are required in sufficient quantities and must be stimulated. We initially assessed the proportions of NKT and NK cells in 34 MM patients. The frequencies of both in PBMC populations correlated with those in BMMNCs irrespective of low BMMNC numbers. We then assessed the adjunctive effect of stimulating NKT cells with CD1d and α-GalCer complexes on the NK cells. The expression of NKG2D on CD56 dim CD16 + NK cells and DNAM-1 on CD56 bright CD16 - NK cells increased after NKT cell activation. Apparently, NK cell-mediated anti-tumor effects were dependent on NKG2D and DNAM-1 ligands on myeloma cells. Thus, NK cell function in patients could be ameliorated, beyond the effect of immunosuppression, by NKT cell activation. This NKT-driven NK cell therapy could represent a potential new treatment modality. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Effect of laser irradiation on cell function and its implications in Raman spectroscopy.

    Science.gov (United States)

    Yuan, Xiaofei; Song, Yanqing; Song, Yizhi; Xu, Jiabao; Wu, Yinhu; Glidle, Andrew; Cusack, Maggie; Ijaz, Umer Z; Cooper, Jonathan M; Huang, Wei E; Yin, Huabing

    2018-02-02

    Lasers are instrumental in advanced bioimaging and Raman spectroscopy. However, they are also well known for their destructive effects on living organisms, leading to concerns about the adverse effects of laser technologies. To implement Raman spectroscopy for cell analysis and manipulation, such as Raman activated cell sorting, it is crucial to identify non-destructive conditions for living cells. Here, we evaluated quantitatively the effect of 532 nm laser irradiation on bacterial cell fate and growth at the single-cell level. Using a purpose-built microfluidic platform, we were able to quantify the growth characteristics i.e. specific growth rate and lag time of individual cells as well as the survival rate of a population in conjunction with Raman spectroscopy. Representative Gram-negative and Gram-positive species show a similar trend in response to laser irradiation dose. Laser irradiation could compromise physiological function of cells and the degree of destruction is both dose and strain dependent, ranging from reduced cell growth to a complete loss of cell metabolic activity and finally to physical disintegration. Gram-positive bacterial cells are more susceptible than Gram-negative bacterial strains to irradiation-induced damage. By directly correlating Raman acquisition with single cell growth characteristics, we provide evidence of non-destructive characteristics of Raman spectroscopy on individual bacterial cells. However, while strong Raman signals can be obtained without causing cell death, the variety of responses from different strains and from individual cells justify careful evaluation of Raman acquisition conditions if cell viability is critical. IMPORTANCE In Raman spectroscopy, the use of powerful monochromatic light in laser-based systems facilitates detection of the inherently weak signals. This allows environmentally and clinically relevant microorganisms to be measured at the single cell level. The significance of being able to perform

  13. Copine1 regulates neural stem cell functions during brain development.

    Science.gov (United States)

    Kim, Tae Hwan; Sung, Soo-Eun; Cheal Yoo, Jae; Park, Jae-Yong; Yi, Gwan-Su; Heo, Jun Young; Lee, Jae-Ran; Kim, Nam-Soon; Lee, Da Yong

    2018-01-01

    Copine 1 (CPNE1) is a well-known phospholipid binding protein in plasma membrane of various cell types. In brain cells, CPNE1 is closely associated with AKT signaling pathway, which is important for neural stem cell (NSC) functions during brain development. Here, we investigated the role of CPNE1 in the regulation of brain NSC functions during brain development and determined its underlying mechanism. In this study, abundant expression of CPNE1 was observed in neural lineage cells including NSCs and immature neurons in human. With mouse brain tissues in various developmental stages, we found that CPNE1 expression was higher at early embryonic stages compared to postnatal and adult stages. To model developing brain in vitro, we used primary NSCs derived from mouse embryonic hippocampus. Our in vitro study shows decreased proliferation and multi-lineage differentiation potential in CPNE1 deficient NSCs. Finally, we found that the deficiency of CPNE1 downregulated mTOR signaling in embryonic NSCs. These data demonstrate that CPNE1 plays a key role in the regulation of NSC functions through the activation of AKT-mTOR signaling pathway during brain development. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. PKC-theta in regulatory and effector T-cell functions

    Directory of Open Access Journals (Sweden)

    Vedran eBrezar

    2015-10-01

    Full Text Available One of the major goals in immunology research is to understand the regulatory mechanisms that underpin the rapid switch on/off of robust and efficient effector (Teff or regulatory (Tregs T-cell responses. Understanding the molecular mechanisms underlying the regulation of such responses is critical for the development of effective therapies. T-cell activation involves the engagement of T-cell receptor and co-stimulatory signals, but the subsequent recruitment of serine/threonine-specific protein Kinase C-theta (PKC-θ to the immunological synapse is instrumental for the formation of signalling complexes, that ultimately lead to a transcriptional network in T cells. Recent studies demonstrated that major differences between Teffs and Tregs occurred at the immunological synapse where its formation induces altered signalling pathways in Tregs. These pathways are characterized by reduced recruitment of PKC-θ, suggesting that PKC-θ inhibits Tregs suppressive function in a negative feedback loop. As the balance of Teffs and Tregs has been shown to be central in several diseases, it was not surprising that some studies revealed that PKC-θ plays a major role in the regulation of this balance.This review will examine recent knowledge on the role of PKC-θ in T-cell transcriptional responses and how this protein can impact on the function of both Tregs and Teffs.

  15. Mitochondrial metabolism in hematopoietic stem cells requires functional FOXO3

    Science.gov (United States)

    Rimmelé, Pauline; Liang, Raymond; Bigarella, Carolina L; Kocabas, Fatih; Xie, Jingjing; Serasinghe, Madhavika N; Chipuk, Jerry; Sadek, Hesham; Zhang, Cheng Cheng; Ghaffari, Saghi

    2015-01-01

    Hematopoietic stem cells (HSC) are primarily dormant but have the potential to become highly active on demand to reconstitute blood. This requires a swift metabolic switch from glycolysis to mitochondrial oxidative phosphorylation. Maintenance of low levels of reactive oxygen species (ROS), a by-product of mitochondrial metabolism, is also necessary for sustaining HSC dormancy. Little is known about mechanisms that integrate energy metabolism with hematopoietic stem cell homeostasis. Here, we identify the transcription factor FOXO3 as a new regulator of metabolic adaptation of HSC. ROS are elevated in Foxo3−/− HSC that are defective in their activity. We show that Foxo3−/− HSC are impaired in mitochondrial metabolism independent of ROS levels. These defects are associated with altered expression of mitochondrial/metabolic genes in Foxo3−/− hematopoietic stem and progenitor cells (HSPC). We further show that defects of Foxo3−/− HSC long-term repopulation activity are independent of ROS or mTOR signaling. Our results point to FOXO3 as a potential node that couples mitochondrial metabolism with HSC homeostasis. These findings have critical implications for mechanisms that promote malignant transformation and aging of blood stem and progenitor cells. PMID:26209246

  16. Critical role of exogenous nitric oxide in ROCK activity in vascular smooth muscle cells.

    Directory of Open Access Journals (Sweden)

    Tatsuya Maruhashi

    Full Text Available Rho-associated kinase (ROCK signaling pathway has been shown to mediate various cellular functions including cell proliferation, migration, adhesion, apoptosis, and contraction, all of which may be involved in pathogenesis of atherosclerosis. Endogenous nitric oxide (NO is well known to have an anti-atherosclerotic effect, whereas the exogenous NO-mediated cardiovascular effect still remains controversial. The purpose of this study was to evaluate the effect of exogenous NO on ROCK activity in vascular smooth muscle cells (VSMCs in vitro and in vivo.VSMCs migration was evaluated using a modified Boyden chamber assay. ROCK activities were measured by Western blot analysis in murine and human VSMCs and aorta of mice treated with or without angiotensin II (Ang II and/or sodium nitroprusside (SNP, an NO donor.Co-treatment with SNP inhibited the Ang II-induced cell migration and increases in ROCK activity in murine and human VSMCs. Similarly, the increased ROCK activity 2 weeks after Ang II infusion in the mouse aorta was substantially inhibited by subcutaneous injection of SNP.These findings suggest that administration of exogenous NO can inhibit ROCK activity in VSMCs in vitro and in vivo.

  17. Reconstitution of ovarian function following transplantation of primordial germ cells.

    Science.gov (United States)

    Zeng, Ming; Sheng, Xiaoyan; Keefe, David L; Liu, Lin

    2017-05-03

    Ovarian aging occurs earlier than somatic aging. We tested the hypothesis that ovarian functions could be artificially reconstructed by transplantation of primordial germ cells (PGCs). We compared various methods for transplantation of PGCs aggregated with gonadal somatic cells and showed that reconstituted ovaries exhibited folliculogenesis after transplantation of PGCs-aggregates into either kidney capsule or ovarian bursa. Neo-oogenesis occurred early after transplantation, as evidenced by the presence of prophase I meiocytes displaying homologous pairing. Moreover, endocrine function was recovered in ovariectomized recipients, including elevated levels of AMH and estradiol. Interestingly, folliculogenesis in the reconstituted ovaries failed to sustain past four weeks. Regardless of transplantation method, follicles diminished after 45 days, accompanied by increased apoptosis, and were undetectable after two months. Meanwhile, no replicative PGCs or prophase I meiocytes could be found. Together, transplantation of PGCs can effectively reconstitute ovarian functions but for limited time. These data suggest that PGCs do not undergo self-renewal but rapidly enter meiosis following transplantation. Global activation of primordial follicles in artificial ovaries can result in further rapid loss of germ cells. Methods for maintaining self-renewal and expansion in vivo of PGCs and controlling follicle activation will be essential for continuing maintenance of the functional reconstructed ovaries.

  18. Undetected scars? Self-criticism, attachment, and romantic relationships among otherwise well-functioning childhood sexual abuse survivors.

    Science.gov (United States)

    Lassri, Dana; Luyten, Patrick; Fonagy, Peter; Shahar, Golan

    2018-01-01

    Studies have consistently demonstrated the negative impact of childhood sexual abuse (CSA) on intimate relationships. The majority of studies have focused on revictimization in at-risk or clinical samples, with very few addressing the impact of CSA on otherwise well-functioning adults and even fewer investigating the psychological mechanisms involved. To fill this gap, this study focuses on the effect of CSA on "normative" (nonviolent) romantic relationships in otherwise well-functioning young women, and the mediating role of personality dimension self-criticism and attachment in this regard. Specifically, we investigate whether self-criticism and attachment avoidance mediate the relationship between CSA and romantic relationship satisfaction, while also examining the potential reciprocal associations between these variables. The hypothesized mediation model was examined in a 2-wave, 6-month, cross-lagged longitudinal design, using structural equation modeling. Participants were 59 well-functioning (psychologically, socially, occupationally) young women drawn from an earlier study that purposefully oversampled for CSA survivors. For the purpose of the current study, data from women who had been either sexually abused by a familiar perpetrator (n = 30) or had no history of sexual trauma (n = 29) were included. Consistent with expectations, self-criticism mediated the association between CSA and romantic relationship satisfaction over time. In addition, a scarring effect of romantic relationship satisfaction on attachment avoidance was demonstrated. Findings suggest that CSA may lead to elevated levels of self-criticism, which in turn may be linked with reduced satisfaction in romantic relationships, setting in motion a vicious cycle involving relationship satisfaction and attachment avoidance. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  19. Neurogenic and non neurogenic functions of endogenous neural stem cells.

    Directory of Open Access Journals (Sweden)

    Erica eButti

    2014-04-01

    Full Text Available Adult neurogenesis is a lifelong process that occurs in two main neurogenic niches of the brain, namely in the subventricular zone (SVZ of the lateral ventricles and in the subgranular zone (SGZ of the dentate gyrus (DG in the hippocampus. In the 1960s, studies on adult neurogenesis have been hampered by the lack of established phenotypic markers. The precise tracing of neural stem/progenitor cells (NPCs was therefore, not properly feasible. After the (partial identification of those markers, it was the lack of specific tools that hindered a proper experimental elimination and tracing of those cells to demonstrate their terminal fate and commitment. Nowadays, irradia-tion, cytotoxic drugs as well as genetic tracing/ablation procedures have moved the field forward and increased our understanding of neurogenesis processes in both physiological and pathological conditions. Newly formed NPC progeny from the SVZ can replace granule cells in the olfactory bulbs of rodents, thus contributing to orchestrate sophisticated odour behaviour. SGZ-derived new granule cells, instead, integrate within the DG where they play an essential role in memory functions. Furthermore, converging evidence claim that endogenous NPCs not only exert neurogenic functions, but might also have non-neurogenic homeostatic functions by the release of different types of neuroprotective molecules. Remarkably, these non-neurogenic homeostatic functions seem to be necessary, both in healthy and diseased conditions, for example for preventing or limiting tissue damage. In this review, we will discuss the neurogenic and the non-neurogenic functions of adult NPCs both in physiological and pathological conditions.

  20. Suppressor cell function is preserved in pemphigus and pemphigoid

    Energy Technology Data Exchange (ETDEWEB)

    King, A.J.; Schwartz, S.A.; Lopatin, D.; Voorhees, J.J.; Diaz, L.A.

    1982-09-01

    Human peripheral blood lymphocytes (PBL) are activated to become suppressor T cells (S-T-C) by incubation with Concanavalin-A (Con-A). This has become the standard method for evaluation of suppressor function in patients. S-T-C function has been found to be impaired in several autoimmune diseases, including systemic lupus erythematosus (SLE). Using this assay, we have investigated suppressor-cell function in 2 autoimmune disorders, bullous pemphigoid (BP) and pemphigus vulgaris (PV), studying 6 patients from each group. Three patients with active SLE (positive controls), and 11 normal donors (negative controls) were also included. None of these patients had received systemic therapy with the exception of 2 patients with PV who were treated with gold in the past. PBL from these patients were incubated with and without 40 micrograms/ml Con-A for 72 hr to generate suppressor cells. Both groups of PBL were then irradiated wih 1500 r cobalt. Co-cultures were set up in sextuplicate using normal PBL as responders. Responder PBL were stimulated with 0.5, 1.0, and 2.0 micrograms/ml of phytohemagglutin (PHA) and 5.0, 10.0, and 20.0 micrograms/ml of Con-A. Cultures were pulsed on day 3 with /sup 3/H-thymidine and harvested on day 4. Data were analyzed using Student's t-test. S-T-C function was found to be significantly impaired in SLE vs normal (p . 0.0316). No statistically significant difference was seen in BP (p . 0.5883) and PV (p . 0.0921) as compared with normals. A defect in suppressor cell function may still be present in patients with PV and BP for the defect may be antigen-specific and therefore remain undetected by the Con-A suppressor assay.

  1. Suppressor cell function is preserved in pemphigus and pemphigoid

    International Nuclear Information System (INIS)

    King, A.J.; Schwartz, S.A.; Lopatin, D.; Voorhees, J.J.; Diaz, L.A.

    1982-01-01

    Human peripheral blood lymphocytes (PBL) are activated to become suppressor T cells (S-T-C) by incubation with Concanavalin-A (Con-A). This has become the standard method for evaluation of suppressor function in patients. S-T-C function has been found to be impaired in several autoimmune diseases, including systemic lupus erythematosus (SLE). Using this assay, we have investigated suppressor-cell function in 2 autoimmune disorders, bullous pemphigoid (BP) and pemphigus vulgaris (PV), studying 6 patients from each group. Three patients with active SLE (positive controls), and 11 normal donors (negative controls) were also included. None of these patients had received systemic therapy with the exception of 2 patients with PV who were treated with gold in the past. PBL from these patients were incubated with and without 40 micrograms/ml Con-A for 72 hr to generate suppressor cells. Both groups of PBL were then irradiated wih 1500 r cobalt. Co-cultures were set up in sextuplicate using normal PBL as responders. Responder PBL were stimulated with 0.5, 1.0, and 2.0 micrograms/ml of phytohemagglutin (PHA) and 5.0, 10.0, and 20.0 micrograms/ml of Con-A. Cultures were pulsed on day 3 with 3 H-thymidine and harvested on day 4. Data were analyzed using Student's t-test. S-T-C function was found to be significantly impaired in SLE vs normal (p . 0.0316). No statistically significant difference was seen in BP (p . 0.5883) and PV (p . 0.0921) as compared with normals. A defect in suppressor cell function may still be present in patients with PV and BP for the defect may be antigen-specific and therefore remain undetected by the Con-A suppressor assay

  2. Age Is Relative—Impact of Donor Age on Induced Pluripotent Stem Cell-Derived Cell Functionality

    Directory of Open Access Journals (Sweden)

    Elisabeth Tamara Strässler

    2018-01-01

    Full Text Available Induced pluripotent stem cells (iPSCs avoid many of the restrictions that hamper the application of human embryonic stem cells: limited availability of source material due to legal restrictions in some countries, immunogenic rejection and ethical concerns. Also, the donor’s clinical phenotype is often known when working with iPSCs. Therefore, iPSCs seem ideal to tackle the two biggest tasks of regenerative medicine: degenerative diseases with genetic cause (e.g., Duchenne’s muscular dystrophy and organ replacement in age-related diseases (e.g., end-stage heart or renal failure, especially in combination with recently developed gene-editing tools. In the setting of autologous transplantation in elderly patients, donor age becomes a potentially relevant factor that needs to be assessed. Here, we review and critically discuss available data pertinent to the questions: How does donor age influence the reprogramming process and iPSC functionality? Would it even be possible to reprogram senescent somatic cells? How does donor age affect iPSC differentiation into specialised cells and their functionality? We also identify research needs, which might help resolve current unknowns. Until recently, most hallmarks of ageing were attributed to an accumulation of DNA damage over time, and it was thus expected that DNA damage from a somatic cell would accumulate in iPSCs and the cells derived from them. In line with this, a decreased lifespan of cloned organisms compared with the donor was also observed in early cloning experiments. Therefore, it was questioned for a time whether iPSC derived from an old individual’s somatic cells would suffer from early senescence and, thus, may not be a viable option either for disease modelling nor future clinical applications. Instead, typical signs of cellular ageing are reverted in the process of iPSC reprogramming, and iPSCs from older donors do not show diminished differentiation potential nor do i

  3. CRITICAL FACTORS IN OUTSOURCING OF ACCOUNTING FUNCTIONS IN MALAYSIAN SMALL MEDIUM-SIZED ENTERPRISES (SMEs

    Directory of Open Access Journals (Sweden)

    Magiswary Dorasamy

    2010-01-01

    Full Text Available The challenges that business face in sustaining competitive advantage in the corporate world have become a major concern. Businesses are adopting cutting-edge technologies and best practices to cope with rapid, global changes. Various business functions are being reengineered for this purpose. Accounting functions play an important role in helping businesses to maintain competitive advantage. However, some small and medium-sized enterprises (SMEs face problems handling fundamental accounting functions. This is predominantly because of their lack of expertise; accounting functions require not only knowledge of generally accepted accounting rules or tax regulations but also the expertise needed to apply the rules in a given business environment (Everaert, Sarens and Rommel, 2006. This paper offers some insight on the outsourcing of accounting functions as there is paucity of data in this area in the context of Malaysia. Essentially, it presents empirical evidence regarding Malaysian SMEs' accounting outsourcing practices. A survey of SMEs was conducted to identify the overall outsourcing landscape as it relates to accounting and third-party organisations. The factors that contribute to the decision to outsource accounting functions are analysed. The study reveals a significant relationship between outsourcing accounting functions and two contributing factors, risks and operation management.

  4. Ouabain modulates cell contacts as well as functions that depend on cell adhesion.

    Science.gov (United States)

    Larre, Isabel; Contreras, Ruben G; Cereijido, Marcelino

    2011-01-01

    Ouabain, a toxic of vegetal origin used for centuries to treat heart failure, has recently been demonstrated to have an endogenous counterpart, most probably ouabain itself, which behaves as a hormone. Therefore, the challenge now is to discover the physiological role of hormone ouabain. We have recently shown that it modulates cell contacts such as gap junctions, which communicate neighboring cells, as well as tight junctions (TJs), which are one of the two differentiated features of epithelial cells, the other being apical/basolateral polarity. The importance of cell contacts can be hardly overestimated, since the most complex object in the universe, the brain, assembles itself depending on what cells contacts what other(s) how, when, and how is the molecular composition and special arrangement of the contacts involved. In the present chapter, we detail the protocols used to demonstrate the effect of ouabain on the molecular structure and functional properties of one of those cell-cell contacts: the TJ.

  5. Angiocrine functions of organ-specific endothelial cells.

    Science.gov (United States)

    Rafii, Shahin; Butler, Jason M; Ding, Bi-Sen

    2016-01-21

    Endothelial cells that line capillaries are not just passive conduits for delivering blood. Tissue-specific endothelium establishes specialized vascular niches that deploy sets of growth factors, known as angiocrine factors. These cues participate actively in the induction, specification, patterning and guidance of organ regeneration, as well as in the maintainance of homeostasis and metabolism. When upregulated following injury, they orchestrate self-renewal and differentiation of tissue-specific resident stem and progenitor cells into functional organs. Uncovering the mechanisms by which organotypic endothelium distributes physiological levels of angiocrine factors both spatially and temporally will lay the foundation for clinical trials that promote organ repair without scarring.

  6. Functional Kidney Bioengineering with Pluripotent Stem-Cell-Derived Renal Progenitor Cells and Decellularized Kidney Scaffolds.

    Science.gov (United States)

    Du, Chan; Narayanan, Karthikeyan; Leong, Meng Fatt; Ibrahim, Mohammed Shahrudin; Chua, Ying Ping; Khoo, Vanessa Mei Hui; Wan, Andrew C A

    2016-08-01

    Recent advances in developmental biology and stem cell technology have led to the engineering of functional organs in a dish. However, the limited size of these organoids and absence of a large circulatory system poses limits to its clinical translation. To overcome these issues, decellularized whole kidney scaffolds with native microstructure and extracellular matrix (ECM) are employed for kidney bioengineering, using human-induced pluripotent-stem-cell-derived renal progenitor cells and endothelial cells. To demonstrate ECM-guided cellular assembly, the present work is focused on generating the functional unit of the kidney, the glomerulus. In the repopulated organ, the presence of endothelial cells broadly upregulates the expression level of genes related to renal development. When the cellularized native scaffolds are implanted in SCID mice, glomeruli assembly can be achieved by co-culture of the renal progenitors and endothelial cells. These individual glomerular units are shown to be functional in the context of the whole organ using a simulated bio-reactor set-up with urea and creatinine excretion and albumin reabsorption. Our results indicate that the repopulation of decellularized native kidney using clinically relevant, expandable patient-specific renal progenitors and endothelial cells may be a viable approach for the generation of a functional whole kidney. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. NKG2D is required for NK cell activation and function in response to E1-deleted adenovirus.

    Science.gov (United States)

    Zhu, Jiangao; Huang, Xiaopei; Yang, Yiping

    2010-12-15

    Despite high transduction efficiency in vivo, the application of recombinant E1-deleted adenoviral vectors for in vivo gene therapy has been limited by the attendant innate and adaptive immune responses to adenoviral vectors. NK cells have been shown to play an important role in innate immune elimination of adenoviral vectors in vivo. However, the mechanisms underlying NK cell activation and function in response to adenoviral vectors remain largely undefined. In this study, we showed that NK cell activation upon adenoviral infection was dependent on accessory cells such as dendritic cells and macrophages and that cell contact-dependent signals from the accessory cells are necessary for NK cell activation. We further demonstrated that ligands of the NK activating receptor NKG2D were upregulated in accessory cells upon adenoviral infection and that blockade of NKG2D inhibited NK cell activation upon adenoviral infection, leading to a delay in adenoviral clearance in vivo. In addition, NKG2D was required for NK cell-mediated cytolysis on adenovirus-infected targets. Taken together, these results suggest that efficient NK cell activation and function in response to adenoviral infection is critically dependent on the NKG2D pathway, which understanding may assist in the design of effective strategies to improve the outcome of adenovirus-mediated gene therapy.

  8. Triazole fungicide tebuconazole disrupts human placental trophoblast cell functions

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jinghua [Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Education, Zhejiang University, Hangzhou 310058 (China); Zhang, Jianyun [Research Center for Air Pollution and Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Li, Feixue [Zhejiang Key Laboratory of Organ Development and Regeneration, Institute of Developmental and Regenerative Biology, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036 (China); Liu, Jing, E-mail: jliue@zju.edu.cn [Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Education, Zhejiang University, Hangzhou 310058 (China); Research Center for Air Pollution and Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China)

    2016-05-05

    Highlights: • Tebuconazole (TEB) inhibited the proliferation of human placental trophoblasts. • TEB changed cell cycle distribution of G1 and G2 phases of trophoblasts. • TEB induced apoptosis of trophoblasts via mitochondrial pathway. • TEB decreased the invasive and migratory capacities of trophoblasts. • TEB altered the mRNA levels of key regulatory genes in trophoblasts - Abstract: Triazole fungicides are one of the top ten classes of current-use pesticides. Although exposure to triazole fungicides is associated with reproductive toxicity in mammals, limited information is available regarding the effects of triazole fungicides on human placental trophoblast function. Tebuconazole (TEB) is a common triazole fungicide that has been extensively used for fungi control. In this work, we showed that TEB could reduce cell viability, disturb normal cell cycle distribution and induce apoptosis of human placental trophoblast cell line HTR-8/SVneo (HTR-8). Bcl-2 protein expression decreased and the level of Bax protein increased after TEB treatment in HTR-8 cells. The results demonstrated that this fungicide induced apoptosis of trophoblast cells via mitochondrial pathway. Importantly, we found that the invasive and migratory capacities of HTR-8 cells decreased significantly after TEB administration. TEB altered the expression of key regulatory genes involved in the modulation of trophoblast functions. Taken together, TEB suppressed human trophoblast invasion and migration through affecting the expression of protease, hormones, angiogenic factors, growth factors and cytokines. As the invasive and migratory abilities of trophoblast are essential for successful placentation and fetus development, our findings suggest a potential risk of triazole fungicides to human pregnancy.

  9. Triazole fungicide tebuconazole disrupts human placental trophoblast cell functions

    International Nuclear Information System (INIS)

    Zhou, Jinghua; Zhang, Jianyun; Li, Feixue; Liu, Jing

    2016-01-01

    Highlights: • Tebuconazole (TEB) inhibited the proliferation of human placental trophoblasts. • TEB changed cell cycle distribution of G1 and G2 phases of trophoblasts. • TEB induced apoptosis of trophoblasts via mitochondrial pathway. • TEB decreased the invasive and migratory capacities of trophoblasts. • TEB altered the mRNA levels of key regulatory genes in trophoblasts - Abstract: Triazole fungicides are one of the top ten classes of current-use pesticides. Although exposure to triazole fungicides is associated with reproductive toxicity in mammals, limited information is available regarding the effects of triazole fungicides on human placental trophoblast function. Tebuconazole (TEB) is a common triazole fungicide that has been extensively used for fungi control. In this work, we showed that TEB could reduce cell viability, disturb normal cell cycle distribution and induce apoptosis of human placental trophoblast cell line HTR-8/SVneo (HTR-8). Bcl-2 protein expression decreased and the level of Bax protein increased after TEB treatment in HTR-8 cells. The results demonstrated that this fungicide induced apoptosis of trophoblast cells via mitochondrial pathway. Importantly, we found that the invasive and migratory capacities of HTR-8 cells decreased significantly after TEB administration. TEB altered the expression of key regulatory genes involved in the modulation of trophoblast functions. Taken together, TEB suppressed human trophoblast invasion and migration through affecting the expression of protease, hormones, angiogenic factors, growth factors and cytokines. As the invasive and migratory abilities of trophoblast are essential for successful placentation and fetus development, our findings suggest a potential risk of triazole fungicides to human pregnancy.

  10. Mesenchymal stem cells generate distinct functional hybrids in vitro via cell fusion or entosis.

    Science.gov (United States)

    Sottile, Francesco; Aulicino, Francesco; Theka, Ilda; Cosma, Maria Pia

    2016-11-09

    Homotypic and heterotypic cell-to-cell fusion are key processes during development and tissue regeneration. Nevertheless, aberrant cell fusion can contribute to tumour initiation and metastasis. Additionally, a form of cell-in-cell structure called entosis has been observed in several human tumours. Here we investigate cell-to-cell interaction between mouse mesenchymal stem cells (MSCs) and embryonic stem cells (ESCs). MSCs represent an important source of adult stem cells since they have great potential for regenerative medicine, even though they are also involved in cancer progression. We report that MSCs can either fuse forming heterokaryons, or be invaded by ESCs through entosis. While entosis-derived hybrids never share their genomes and induce degradation of the target cell, fusion-derived hybrids can convert into synkaryons. Importantly we show that hetero-to-synkaryon transition occurs through cell division and not by nuclear membrane fusion. Additionally, we also observe that the ROCK-actin/myosin pathway is required for both fusion and entosis in ESCs but only for entosis in MSCs. Overall, we show that MSCs can undergo fusion or entosis in culture by generating distinct functional cellular entities. These two processes are profoundly different and their outcomes should be considered given the beneficial or possible detrimental effects of MSC-based therapeutic applications.

  11. Functional mapping of cell surface proteins with localized stimulation of single cells

    Science.gov (United States)

    Sun, Bingyun; Chiu, Daniel T.

    2003-11-01

    This paper describes the development of using individual micro and nano meter-sized vesicles as delivery vessels to functionally map the distribution of cell surface proteins at the level of single cells. The formation of different sizes of vesicles from tens of nanometers to a few micrometers in diameter that contain the desired molecules is addressed. An optical trap is used to manipulate the loaded vesicle to specific cell morphology of interest, and a pulsed UV laser is used to photo-release the stimuli onto the cell membrane. Carbachol activated cellular calcium flux, upon binding to muscarinic acetylcholine receptors, is studied by this method, and the potential of using this method for the functional mapping of localized proteins on the cell surface membrane is discussed.

  12. Inhibition of NAMPT pathway by FK866 activates the function of p53 in HEK293T cells

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, Basant Kumar, E-mail: thakur.basant@mh-hannover.de [Department of Pediatrics, Hematology and Oncology, Hannover Medical School, Carl Neuberg Str-1, 30625 Hannover (Germany); Department of Molecular Hematopoiesis, Hannover Medical School, Carl Neuberg Str-1, 30625 Hannover (Germany); Dittrich, Tino [Department of Pediatrics, Hematology and Oncology, Hannover Medical School, Carl Neuberg Str-1, 30625 Hannover (Germany); Department of Molecular Hematopoiesis, Hannover Medical School, Carl Neuberg Str-1, 30625 Hannover (Germany); Chandra, Prakash [Frankfurt University Medical School, Molecular Biology, Building 57, Theodor-Stern-Kai-7, 60590 Frankfurt (Germany); Becker, Annette [Department of Biology, Technical University of Darmstadt, 64287 Darmstadt (Germany); Lippka, Yannick [Department of Molecular Hematopoiesis, Hannover Medical School, Carl Neuberg Str-1, 30625 Hannover (Germany); Selvakumar, Divakarvel [Department of Molecular Hematopoiesis, Hannover Medical School, Carl Neuberg Str-1, 30625 Hannover (Germany); Rutgers, The State University of New Jersey, NJ 08901 (United States); Klusmann, Jan-Henning; Reinhardt, Dirk [Department of Pediatrics, Hematology and Oncology, Hannover Medical School, Carl Neuberg Str-1, 30625 Hannover (Germany); Welte, Karl, E-mail: Welte.Karl.H@mh-hannover.de [Department of Molecular Hematopoiesis, Hannover Medical School, Carl Neuberg Str-1, 30625 Hannover (Germany)

    2012-08-03

    Highlights: Black-Right-Pointing-Pointer In 293T cells, p53 is considered to be inactive due to its interaction with the large T-antigen. Black-Right-Pointing-Pointer Acetylation of p53 at lysine 382 is important for its functional activation. Black-Right-Pointing-Pointer First evidence to document the presence of a functional p53 in 293T cells. Black-Right-Pointing-Pointer Inhibition of NAMPT/SIRT pathway by FK866 in 293T cells increases the functional activity of p53. Black-Right-Pointing-Pointer This activation of p53 involves reversible acetylation of p53 at lysine 382. -- Abstract: Inactivation of p53 protein by endogenous and exogenous carcinogens is involved in the pathogenesis of different human malignancies. In cancer associated with SV-40 DNA tumor virus, p53 is considered to be non-functional mainly due to its interaction with the large T-antigen. Using the 293T cell line (HEK293 cells transformed with large T antigen) as a model, we provide evidence that p53 is one of the critical downstream targets involved in FK866-mediated killing of 293T cells. A reduced rate of apoptosis and an increased number of cells in S-phase was accompanied after knockdown of p53 in these cells. Inhibition of NAMPT by FK866, or inhibition of SIRT by nicotinamide decreased proliferation and triggered death of 293T cells involving the p53 acetylation pathway. Additionally, knockdown of p53 attenuated the effect of FK866 on cell proliferation, apoptosis, and cell cycle arrest. The data presented here shed light on two important facts: (1) that p53 in 293T cells is active in the presence of FK866, an inhibitor of NAMPT pathway; (2) the apoptosis induced by FK866 in 293T cells is associated with increased acetylation of p53 at Lys382, which is required for the functional activity of p53.

  13. Na+ -K+ -2Cl- Cotransporter (NKCC) Physiological Function in Nonpolarized Cells and Transporting Epithelia.

    Science.gov (United States)

    Delpire, Eric; Gagnon, Kenneth B

    2018-03-25

    Two genes encode the Na + -K + -2Cl - cotransporters, NKCC1 and NKCC2, that mediate the tightly coupled movement of 1Na + , 1K + , and 2Cl - across the plasma membrane of cells. Na + -K + -2Cl - cotransport is driven by the chemical gradient of the three ionic species across the membrane, two of them maintained by the action of the Na + /K + pump. In many cells, NKCC1 accumulates Cl - above its electrochemical potential equilibrium, thereby facilitating Cl - channel-mediated membrane depolarization. In smooth muscle cells, this depolarization facilitates the opening of voltage-sensitive Ca 2+ channels, leading to Ca 2+ influx, and cell contraction. In immature neurons, the depolarization due to a GABA-mediated Cl - conductance produces an excitatory rather than inhibitory response. In many cell types that have lost water, NKCC is activated to help the cells recover their volume. This is specially the case if the cells have also lost Cl - . In combination with the Na + /K + pump, the NKCC's move ions across various specialized epithelia. NKCC1 is involved in Cl - -driven fluid secretion in many exocrine glands, such as sweat, lacrimal, salivary, stomach, pancreas, and intestine. NKCC1 is also involved in K + -driven fluid secretion in inner ear, and possibly in Na + -driven fluid secretion in choroid plexus. In the thick ascending limb of Henle, NKCC2 activity in combination with the Na + /K + pump participates in reabsorbing 30% of the glomerular-filtered Na + . Overall, many critical physiological functions are maintained by the activity of the two Na + -K + -2Cl - cotransporters. In this overview article, we focus on the functional roles of the cotransporters in nonpolarized cells and in epithelia. © 2018 American Physiological Society. Compr Physiol 8:871-901, 2018. Copyright © 2018 American Physiological Society. All rights reserved.

  14. Are red blood cell transfusions associated with nosocomial infections in critically ill children?

    Science.gov (United States)

    Naveda Romero, Omar E; Naveda Meléndez, Andrea F

    2016-08-01

    Although the transfusionofblood products is common practice, its effects on the immune system have not been adequately studied. A prospective cohort study was conducted in critically ill children followed up until their death, transfer or discharge to establish an association between red blood cell transfusions (RBCTs) and nosocomial infections. A nosocomial infection was considered to be post-transfusional if it occurred within 14 days after RBCT. A total of 162 children were included in the study, 35 (21.6%) had a nosocomial infection, and 49 (30.2%) received a RBCT. Among those with a nosocomial infection, a RBCT was more common (48.5% versus 14.9%, OR: 5.4, 95% CI: 2.412.6, p 〈 0.0001) and mortality rate was higher (45.7% versus 10.2%, OR: 7.4, 95% CI: 3.1-18.2, p 〈 0.0001). The binary logistic regression showed that RBCT was independently associated with nosocomial infections (OR: 4.2, 95% CI: 2.1-20.2, p = 0.049). RBCT was associated with increased risk for nosocomial infections. Sociedad Argentina de Pediatría.

  15. Lung function after allogeneic hematopoietic stem cell transplantation in children

    DEFF Research Database (Denmark)

    Uhlving, Hilde Hylland; Larsen Bang, Cæcilie; Christensen, Ib Jarle

    2013-01-01

    Reduction in pulmonary function (PF) has been reported in up to 85% of pediatric patients during the first year after hematopoietic stem cell transplantation (HSCT). Our understanding of the etiology for this decrease in lung function is, however, sparse. The aim of this study was to describe PF......-versus-host disease (GvHD). Other factors associated with PF decline were malignant diagnosis, busulfan-based conditioning, patient and donor age, female donor to male recipient, as well as chronic GvHD. Mild to moderate decline in PF is frequent and appears associated with acute GvHD and other parameters...

  16. Genetic deletion of Mst1 alters T cell function and protects against autoimmunity.

    Directory of Open Access Journals (Sweden)

    Konstantin V Salojin

    Full Text Available Mammalian sterile 20-like kinase 1 (Mst1 is a MAPK kinase kinase kinase which is involved in a wide range of cellular responses, including apoptosis, lymphocyte adhesion and trafficking. The contribution of Mst1 to Ag-specific immune responses and autoimmunity has not been well defined. In this study, we provide evidence for the essential role of Mst1 in T cell differentiation and autoimmunity, using both genetic and pharmacologic approaches. Absence of Mst1 in mice reduced T cell proliferation and IL-2 production in vitro, blocked cell cycle progression, and elevated activation-induced cell death in Th1 cells. Mst1 deficiency led to a CD4+ T cell development path that was biased toward Th2 and immunoregulatory cytokine production with suppressed Th1 responses. In addition, Mst1-/- B cells showed decreased stimulation to B cell mitogens in vitro and deficient Ag-specific Ig production in vivo. Consistent with altered lymphocyte function, deletion of Mst1 reduced the severity of experimental autoimmune encephalomyelitis (EAE and protected against collagen-induced arthritis development. Mst1-/- CD4+ T cells displayed an intrinsic defect in their ability to respond to encephalitogenic antigens and deletion of Mst1 in the CD4+ T cell compartment was sufficient to alleviate CNS inflammation during EAE. These findings have prompted the discovery of novel compounds that are potent inhibitors of Mst1 and exhibit desirable pharmacokinetic properties. In conclusion, this report implicates Mst1 as a critical regulator of adaptive immune responses, Th1/Th2-dependent cytokine production, and as a potential therapeutic target for immune disorders.

  17. Interaction of multi-functional silver nanoparticles with living cells

    International Nuclear Information System (INIS)

    Sur, Ilknur; Cam, Dilek; Kahraman, Mehmet; Culha, Mustafa; Baysal, Asli

    2010-01-01

    Silver nanoparticles (AgNPs) are widely used in household products and in medicine due to their antibacterial and to wound healing properties. In recent years, there is also an effort for their use in biomedical imaging and photothermal therapy. The primary reason behind the effort for their utility in biomedicine and therapy is their unique plasmonic properties and easy surface chemistry for a variety of functionalizations. In this study, AgNPs modified with glucose, lactose, oligonucleotides and combinations of these ligands are investigated for their cytotoxicity and cellular uptake in living non-cancer (L929) and cancer (A549) cells. It is found that the chemical nature of the ligand strongly influences the toxicity and cellular uptake into the model cells. While the lactose-and glucose-modified AgNPs enter the L929 cells at about the same rate, a significant increase in the rate of lactose-modified AgNPs into the A549 cells is observed. The binding of oligonucleotides along with the carbohydrate on the AgNP surfaces influences the differential uptake rate pattern into the cells. The cytotoxicity study with the modified AgNPs reveals that only naked AgNPs influence the viability of the A549 cells. The findings of this study may provide the key to developing effective applications in medicine such as cancer therapy.

  18. Calcium exchange, structure, and function in cultured adult myocardial cells

    International Nuclear Information System (INIS)

    Langer, G.A.; Frank, J.S.; Rich, T.L.; Orner, F.B.

    1987-01-01

    Cells digested from adult rat heart and cultured for 14 days demonstrate all the structural elements, in mature form, associated with the process of excitation-contraction (EC) coupling. The transverse tubular (TT) system is well developed with an extensive junctional sarcoplasmic reticulum (JSR). In nonphosphate-containing buffer contraction of the cells is lost as rapidly as zero extracellular Ca concentration ([Ca] 0 ) solution is applied and a negative contraction staircase is produced on increase of stimulation frequency. Structurally and functionally the cells have the characteristics of adult cells in situ. 45 Ca exchange and total 45 Ca measurement in N-2-hydroxyethylpiperazine N'-2-ethanesulfonic acid (HEPES)-buffered perfusate define three components of cellular Ca: 1) a rapidly exchangeable component accounting for 36% of total Ca, 2) a slowly exchangeable component (t/sub 1/2/ 53 min) accounting for 7% total Ca, and 3) the remaining 57% cellular Ca is inexchangeable (demonstrates no significant exchange within 60 min). The slowly exchangeable component can be increased 10-fold within 60 min by addition of phosphate to the perfusate. The Ca distribution and exchange characteristics are little different from those of 3-day cultures of neonatal rat heart previously studied. The results suggest that the cells are representative of adult cells in situ and that both sarcolemmal-bound and sarcoplasmic reticular Ca contribute to the component of Ca that is rapidly exchangeable

  19. Mouse background strain profoundly influences Paneth cell function and intestinal microbial composition.

    Directory of Open Access Journals (Sweden)

    Ajay S Gulati

    Full Text Available Increasing evidence supports the central role of Paneth cells in maintaining intestinal host-microbial homeostasis. However, the direct impact of host genotype on Paneth cell function remains unclear. Here, we characterize key differences in Paneth cell function and intestinal microbial composition in two widely utilized, genetically distinct mouse strains (C57BL/6 and 129/SvEv. In doing so, we demonstrate critical influences of host genotype on Paneth cell activity and the enteric microbiota.Paneth cell numbers were determined