Anti-CD20 B-cell depletion enhances monocyte reactivity in neuroimmunological disorders

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Hohlfeld Reinhard

2011-10-01

Full Text Available Abstract Background Clinical trials evaluating anti-CD20-mediated B-cell depletion in multiple sclerosis (MS and neuromyelitis optica (NMO generated encouraging results. Our recent studies in the MS model experimental autoimmune encephalomyelitis (EAE attributed clinical benefit to extinction of activated B-cells, but cautioned that depletion of naïve B-cells may be undesirable. We elucidated the regulatory role of un-activated B-cells in EAE and investigated whether anti-CD20 may collaterally diminish regulatory B-cell properties in treatment of neuroimmunological disorders. Methods Myelin oligodendrocyte glycoprotein (MOG peptide-immunized C57Bl/6 mice were depleted of B-cells. Functional consequences for regulatory T-cells (Treg and cytokine production of CD11b+ antigen presenting cells (APC were assessed. Peripheral blood mononuclear cells from 22 patients receiving anti-CD20 and 23 untreated neuroimmunological patients were evaluated for frequencies of B-cells, T-cells and monocytes; monocytic reactivity was determined by TNF-production and expression of signalling lymphocytic activation molecule (SLAM. Results We observed that EAE-exacerbation upon depletion of un-activated B-cells closely correlated with an enhanced production of pro-inflammatory TNF by CD11b+ APC. Paralleling this pre-clinical finding, anti-CD20 treatment of human neuroimmunological disorders increased the relative frequency of monocytes and accentuated pro-inflammatory monocyte function; when reactivated ex vivo, a higher frequency of monocytes from B-cell depleted patients produced TNF and expressed the activation marker SLAM. Conclusions These data suggest that in neuroimmunological disorders, pro-inflammatory APC activity is controlled by a subset of B-cells which is eliminated concomitantly upon anti-CD20 treatment. While this observation does not conflict with the general concept of B-cell depletion in human autoimmunity, it implies that its safety and

Bone marrow macrophages maintain hematopoietic stem cell (HSC) niches and their depletion mobilizes HSCs.

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Winkler, Ingrid G; Sims, Natalie A; Pettit, Allison R; Barbier, Valérie; Nowlan, Bianca; Helwani, Falak; Poulton, Ingrid J; van Rooijen, Nico; Alexander, Kylie A; Raggatt, Liza J; Lévesque, Jean-Pierre

2010-12-02

In the bone marrow, hematopoietic stem cells (HSCs) reside in specific niches near osteoblast-lineage cells at the endosteum. To investigate the regulation of these endosteal niches, we studied the mobilization of HSCs into the bloodstream in response to granulocyte colony-stimulating factor (G-CSF). We report that G-CSF mobilization rapidly depletes endosteal osteoblasts, leading to suppressed endosteal bone formation and decreased expression of factors required for HSC retention and self-renewal. Importantly, G-CSF administration also depleted a population of trophic endosteal macrophages (osteomacs) that support osteoblast function. Osteomac loss, osteoblast suppression, and HSC mobilization occurred concomitantly, suggesting that osteomac loss could disrupt endosteal niches. Indeed, in vivo depletion of macrophages, in either macrophage Fas-induced apoptosis (Mafia) transgenic mice or by administration of clodronate-loaded liposomes to wild-type mice, recapitulated the: (1) loss of endosteal osteoblasts and (2) marked reduction of HSC-trophic cytokines at the endosteum, with (3) HSC mobilization into the blood, as observed during G-CSF administration. Together, these results establish that bone marrow macrophages are pivotal to maintain the endosteal HSC niche and that the loss of such macrophages leads to the egress of HSCs into the blood.

Radiosensitization of CHO cells by the combination of glutathione depletion and low concentrations of oxygen: The effect of different levels of GSH depletion

International Nuclear Information System (INIS)

Clark, E.P.; Epp, E.R.; Zachgo, E.A.; Biaglow, J.E.

1984-01-01

Recently, the authors have examined the effect of GSH depletion by BSO on CHO cells equilibrated with oxygen at various concentrations (0.05-4.0%) and irradiated with 50 kVp x-rays. This is of interest because of the uncertain radiosensitizing effect GSH depletion may have on cells equilibrated with low oxygen concentrations. GSH depletion (0.1 mM BSO/24 hrs reduced [GSH] ≅ 10% of control) enhanced the radiosensitizing action of moderate (0.4-4.0%) concentrations of oxygen, i.e., GSH depletion reduced the [O/sub 2/] necessary to achieve an equivalent ER by ≅ 2-3 fold. However, GSH depletion was much more effective as a rediosensitizer when cells were equilibrated with low (<0.4%) concentrations of oxygen, i.e., GSH depletion reduced the [O/sub 2/] necessary to achieve an equivalent ER by 8-10 fold. Furthermore, while the addition of exogenous 5 mM GSH restored the ER to that observed when GSH was not depleted, the intracellular [GSH] was not increased. The results of these studies carried out at different levels of GSH depletion are presented

Role of immune activation in CD4+ T-cell depletion in HIV-1 infected Indian patients.

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Vajpayee, M; Kaushik, S; Sreenivas, V; Mojumdar, K; Mendiratta, S; Chauhan, N K

2009-01-01

The correlation of immune activation with CD4(+) depletion and HIV-1 disease progression has been evidenced by several studies involving mainly clade B virus. However, this needs to be investigated in developing countries such as India predominately infected with clade C virus. In a cross-sectional study of 68 antiretroviral treatment naïve, HIV-1 infected Indian patients, we studied the association between CD4(+) T cells, plasma HIV-1 RNA levels, and immune activation markers using unadjusted and adjusted correlative analyses. Significant negative correlations of higher magnitude were observed between the CD4(+) T cell percentages and plasma HIV-1 RNA levels in the study population when adjusted for the effects of immune activation markers. However, the negative association of CD4(+) T cells with immune activation markers remained unaffected when controlled for the effects of plasma HIV-1 RNA levels. Our results support the important role of immune activation in CD4(+) T cell depletion and disease progression during untreated HIV-1 infection.

Distinct phenotype, longitudinal changes of numbers and cell-associated virus in blood dendritic cells in SIV-infected CD8-lymphocyte depleted macaques.

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Caroline Soulas

Full Text Available Loss of circulating CD123+ plasmacytoid dendritic cells (pDCs during HIV infection is well established. However, changes of myeloid DCs (mDCs are ambiguous since they are studied as a homogeneous CD11c+ population despite phenotypic and functional heterogeneity. Heterogeneity of CD11c+ mDCs in primates is poorly described in HIV and SIV infection. Using multiparametric flow cytometry, we monitored longitudinally cell number and cell-associated virus of CD123+ pDCs and non-overlapping subsets of CD1c+ and CD16+ mDCs in SIV-infected CD8-depleted rhesus macaques. The numbers of all three DC subsets were significantly decreased by 8 days post-infection. Whereas CD123+ pDCs were persistently depleted, numbers of CD1c+ and CD16+ mDCs rebounded. Numbers of CD1c+ mDCs significantly increased by 3 weeks post-infection while numbers of CD16+ mDCs remained closer to pre-infection levels. We found similar changes in the numbers of all three DC subsets in CD8 depleted animals as we found in animals that were SIV infected animals that were not CD8 lymphocyte depleted. CD16+ mDCs and CD123+ pDCs but not CD1c+ mDCs were significantly decreased terminally with AIDS. All DC subsets harbored SIV RNA as early as 8 days and then throughout infection. However, SIV DNA was only detected in CD123+ pDCs and only at 40 days post-infection consistent with SIV RNA, at least in mDCs, being surface-bound. Altogether our data demonstrate that SIV infection differently affects CD1c+ and CD16+ mDCs where CD16+ but not CD1c+ mDCs are depleted and might be differentially regulated in terminal AIDS. Finally, our data underline the importance of studying CD1c+ and CD16+ mDCs as discrete populations, and not as total CD11c+ mDCs.

CENPA overexpression promotes genome instability in pRb-depleted human cells

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Lentini Laura

2009-12-01

Full Text Available Abstract Background Aneuploidy is a hallmark of most human cancers that arises as a consequence of chromosomal instability and it is frequently associated with centrosome amplification. Functional inactivation of the Retinoblastoma protein (pRb has been indicated as a cause promoting chromosomal instability as well centrosome amplification. However, the underlying molecular mechanism still remains to be clarified. Results Here we show that pRb depletion both in wild type and p53 knockout HCT116 cells was associated with the presence of multipolar spindles, anaphase bridges, lagging chromosomes and micronuclei harbouring whole chromosomes. In addition aneuploidy caused by pRb acute loss was not affected by p53 loss. Quantitative real-time RT-PCR showed that pRB depletion altered expression of genes involved in centrosome duplication, kinetochore assembly and in the Spindle Assembly Checkpoint (SAC. However, despite MAD2 up-regulation pRb-depleted cells seemed to have a functional SAC since they arrested in mitosis after treatments with mitotic poisons. Moreover pRb-depleted HCT116 cells showed BRCA1 overexpression that seemed responsible for MAD2 up-regulation. Post-transcriptional silencing of CENPA by RNA interference, resulting in CENP-A protein levels similar to those present in control cells greatly reduced aneuploid cell numbers in pRb-depleted cells. Conclusion Altogether our findings indicate a novel aspect of pRb acute loss that promotes aneuploidy mainly by inducing CENPA overexpression that in turn might induce micronuclei by affecting the correct attachment of spindle microtubules to kinetochores.

Local stem cell depletion model for normal tissue damage

International Nuclear Information System (INIS)

Yaes, R.J.; Keland, A.

1987-01-01

The hypothesis that radiation causes normal tissue damage by completely depleting local regions of tissue of viable stem cells leads to a simple mathematical model for such damage. In organs like skin and spinal cord where destruction of a small volume of tissue leads to a clinically apparent complication, the complication probability is expressed as a function of dose, volume and stem cell number by a simple triple negative exponential function analogous to the double exponential function of Munro and Gilbert for tumor control. The steep dose response curves for radiation myelitis that are obtained with our model are compared with the experimental data for radiation myelitis in laboratory rats. The model can be generalized to include other types or organs, high LET radiation, fractionated courses of radiation, and cases where an organ with a heterogeneous stem cell population receives an inhomogeneous dose of radiation. In principle it would thus be possible to determine the probability of tumor control and of damage to any organ within the radiation field if the dose distribution in three dimensional space within a patient is known

Infection and depletion of CD4+ group-1 innate lymphoid cells by HIV-1 via type-I interferon pathway.

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Juanjuan Zhao

2018-01-01

Full Text Available Innate lymphoid cells (ILCs are severely depleted during chronic HIV-1 infection by unclear mechanisms. We report here that human ILC1s comprising of CD4+ and CD4- subpopulations were present in various human lymphoid organs but with different transcription programs and functions. Importantly, CD4+ ILC1s expressed HIV-1 co-receptors and were productively infected by HIV-1 in vitro and in vivo. Furthermore, chronic HIV-1 infection activated and depleted both CD4+ and CD4- ILC1s, and impaired their cytokine production activity. Highly active antiretroviral (HAART therapy in HIV-1 patients efficiently rescued the ILC1 numbers and reduced their activation, but failed to restore their functionality. We also found that blocking type-I interferon (IFN-I signaling during HIV-1 infection in vivo in humanized mice prevented HIV-1 induced depletion or apoptosis of ILC1 cells. Therefore, we have identified the CD4+ ILC1 cells as a new target population for HIV-1 infection, and revealed that IFN-I contributes to the depletion of ILC1s during HIV-1 infection.

Cation depletion by the sodium pump in red cells with pathologic cation leaks. Sickle cells and xerocytes.

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Joiner, C H; Platt, O S; Lux, S E

1986-01-01

The mechanism by which sickle cells and xerocytic red cells become depleted of cations in vivo has not been identified previously. Both types of cells exhibit elevated permeabilities to sodium and potassium, in the case of sickle cells, when deoxygenated. The ouabain-insensitive fluxes of sodium and potassium were equivalent, however, in both cell types under these conditions. When incubated 18 hours in vitro, sickle cells lost cations but only when deoxygenated. This cation depletion was blo...

Cation depletion by the sodium pump in red cells with pathologic cation leaks. Sickle cells and xerocytes.

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Joiner, C H; Platt, O S; Lux, S E

1986-12-01

The mechanism by which sickle cells and xerocytic red cells become depleted of cations in vivo has not been identified previously. Both types of cells exhibit elevated permeabilities to sodium and potassium, in the case of sickle cells, when deoxygenated. The ouabain-insensitive fluxes of sodium and potassium were equivalent, however, in both cell types under these conditions. When incubated 18 hours in vitro, sickle cells lost cations but only when deoxygenated. This cation depletion was blocked by ouabain, removal of external potassium, or pretreatment with 4,4'-diisothiocyanostilbene-2,2'-disulfonate, which blocks the increase in cation permeability induced by deoxygenation. The loss of cation exhibited by oxygenated xerocytes similarly incubated was also blocked by ouabain. These data support the hypothesis that the elevated "passive" cation fluxes of xerocytes and deoxygenated sickle cells are not directly responsible for cation depletion of these cells; rather, these pathologic leaks interact with the sodium pump to produce a net loss of cellular cation.

Determination of Mother Centriole Maturation in CPAP-Depleted Cells Using the Ninein Antibody

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Miseon Lee

2015-03-01

Full Text Available BackgroundMutations in centrosomal protein genes have been identified in a number of genetic diseases in brain development, including microcephaly. Centrosomal P4.1-associated protein (CPAP is one of the causal genes implicated in primary microcephaly. We previously proposed that CPAP is essential for mother centriole maturation during mitosis.MethodsWe immunostained CPAP-depleted cells using the ninein antibody, which selectively detects subdistal appendages in mature mother centrioles.ResultsNinein signals were significantly impaired in CPAP-depleted cells.ConclusionThe results suggest that CPAP is required for mother centriole maturation in mammalian cells. The selective absence of centriolar appendages in young mother centrioles may be responsible for asymmetric spindle pole formation in CPAP-depleted cells.

Depletion of gamma-glutamylcyclotransferase in cancer cells induces autophagy followed by cellular senescence.

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Taniguchi, Keiko; Matsumura, Kengo; Ii, Hiromi; Kageyama, Susumu; Ashihara, Eishi; Chano, Tokuhiro; Kawauchi, Akihiro; Yoshiki, Tatsuhiro; Nakata, Susumu

2018-01-01

Gamma-glutamylcyclotransferase (GGCT) was originally identified as a protein highly expressed in bladder cancer tissues by proteomic analysis, and its higher expression in a variety of cancers compared to normal tissues have been shown. Depletion of GGCT in various cancer cells results in antiproliferative effects both in vitro and in vivo ; thus it is considered a promising therapeutic target. Although it has been shown that knockdown of GGCT induces cellular senescence and non-apoptotic cell death, associated with upregulation of cyclin-dependent kinase inhibitors (CDKIs) including p21 WAF1/CIP1 , the cellular events that follow GGCT depletion are not fully understood. Here, we show that GGCT depletion induced autophagy in MCF7 breast and PC3 prostate cancer cells. Conversely, overexpression of GGCT in NIH3T3 fibroblast under conditions of serum deprivation inhibited autophagy and increased proliferation. Simultaneous knockdown of autophagy related-protein 5, a critical effector of autophagy, along with GGCT in MCF7 and PC3 cells led to significant attenuation of the multiple cellular responses, including upregulation of CDKIs, increased numbers of senescence-associated β-galactosidase positive senescent cells, and growth inhibition. Furthermore, we show that autophagy-promoting signaling cascades including activation of the AMPK-ULK1 pathway and/or inactivation of the mTORC2-Akt pathway were triggered in GGCT-depleted cells. These results indicate that autophagy plays an important role in the growth inhibition of cancer cells caused by GGCT depletion.

B-cell-depleting Therapy in Systemic Lupus Erythematosus

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Ramos-Casals, Manuel; Sanz, Iñaki; Bosch, Xavier; Stone, John H.; Khamashta, Munther A.

2014-01-01

The emergence of a new class of agents (B-cell-depleting therapies) has opened a new era in the therapeutic approach to systemic lupus erythematosus, with belimumab being the first drug licensed for use in systemic lupus erythematosus in more than 50 years. Four agents deserve specific mention: rituximab, ocrelizumab, epratuzumab, and belimumab. Controlled trials have shown negative results for rituximab, promising results for epratuzumab, and positive results for belimumab. Despite these negative results, rituximab is the most-used agent in patients who do not respond or are intolerant to standard therapy and those with life-threatening presentations. B-cell-depleting agents should not be used in patients with mild disease and should be tailored according to individual patient characteristics, including ethnicity, organ involvement, and the immunological profile. Forthcoming studies of B-cell-directed strategies, particularly data from investigations of off-label rituximab use and postmarketing studies of belimumab, will provide new insights into the utility of these treatments in the routine management of patients with systemic lupus erythematosus. PMID:22444096

Inducible satellite cell depletion attenuates skeletal muscle regrowth following a scald-burn injury.

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Finnerty, Celeste C; McKenna, Colleen F; Cambias, Lauren A; Brightwell, Camille R; Prasai, Anesh; Wang, Ye; El Ayadi, Amina; Herndon, David N; Suman, Oscar E; Fry, Christopher S

2017-11-01

Severe burns result in significant skeletal muscle cachexia that impedes recovery. Activity of satellite cells, skeletal muscle stem cells, is altered following a burn injury and likely hinders regrowth of muscle. Severe burn injury induces satellite cell proliferation and fusion into myofibres with greater activity in muscles proximal to the injury site. Conditional depletion of satellite cells attenuates recovery of myofibre area and volume following a scald burn injury in mice. Skeletal muscle regrowth following a burn injury requires satellite cell activity, underscoring the therapeutic potential of satellite cells in the prevention of prolonged frailty in burn survivors. Severe burns result in profound skeletal muscle atrophy; persistent muscle atrophy and weakness are major complications that hamper recovery from burn injury. Many factors contribute to the erosion of muscle mass following burn trauma, and we have previously shown concurrent activation and apoptosis of muscle satellite cells following a burn injury in paediatric patients. To determine the necessity of satellite cells during muscle recovery following a burn injury, we utilized a genetically modified mouse model (Pax7 CreER -DTA) that allows for the conditional depletion of satellite cells in skeletal muscle. Additionally, mice were provided 5-ethynyl-2'-deoxyuridine to determine satellite cell proliferation, activation and fusion. Juvenile satellite cell-wild-type (SC-WT) and satellite cell-depleted (SC-Dep) mice (8 weeks of age) were randomized to sham or burn injury consisting of a dorsal scald burn injury covering 30% of total body surface area. Both hindlimb and dorsal muscles were studied at 7, 14 and 21 days post-burn. SC-Dep mice had >93% depletion of satellite cells compared to SC-WT (P satellite cell proliferation and fusion. Depletion of satellite cells impaired post-burn recovery of both muscle fibre cross-sectional area and volume (P satellite cells in the aetiology of lean

Contrasting Effects of Systemic Monocyte/Macrophage and CD4+ T Cell Depletion in a Reversible Ureteral Obstruction Mouse Model of Chronic Kidney Disease

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Lee D. Chaves

2013-01-01

Full Text Available Using a reversible UUO model (rUUO, we have demonstrated that C57BL/6 mice are susceptible to development of CKD after obstruction-mediated kidney injury while BALB/c mice are resistant. We hypothesized that selective systemic depletion of subpopulations of inflammatory cells during injury or repair might alter the development of CKD. To investigate the impact of modification of Th-lymphocytes or macrophage responses on development of CKD after rUUO, we used an anti-CD4 antibody (GK1.5 or liposomal clodronate to systemically deplete CD4+ T cells or monocyte/macrophages, respectively, prior to and throughout the rUUO protocol. Flow cytometry and immunohistochemistry confirmed depletion of target cell populations. C57BL/6 mice treated with the GK1.5 antibody to deplete CD4+ T cells had higher BUN levels and delayed recovery from rUUO. Treatment of C57BL/6 mice with liposomal clodronate to deplete monocyte/macrophages led to a relative protection from CKD as assessed by BUN values. Our results demonstrate that modulation of the inflammatory response during injury and repair altered the susceptibility of C57BL/6 mice to development of CKD in our rUUO model.

Riboflavin Depletion Promotes Tumorigenesis in HEK293T and NIH3T3 Cells by Sustaining Cell Proliferation and Regulating Cell Cycle-Related Gene Transcription.

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Long, Lin; He, Jian-Zhong; Chen, Ye; Xu, Xiu-E; Liao, Lian-Di; Xie, Yang-Min; Li, En-Min; Xu, Li-Yan

2018-05-07

Riboflavin is an essential component of the human diet and its derivative cofactors play an established role in oxidative metabolism. Riboflavin deficiency has been linked with various human diseases. The objective of this study was to identify whether riboflavin depletion promotes tumorigenesis. HEK293T and NIH3T3 cells were cultured in riboflavin-deficient or riboflavin-sufficient medium and passaged every 48 h. Cells were collected every 5 generations and plate colony formation assays were performed to observe cell proliferation. Subcutaneous tumorigenicity assays in NU/NU mice were used to observe tumorigenicity of riboflavin-depleted HEK293T cells. Mechanistically, gene expression profiling and gene ontology analysis were used to identify abnormally expressed genes induced by riboflavin depletion. Western blot analyses, cell cycle analyses, and chromatin immunoprecipitation were used to validate the expression of cell cycle-related genes. Plate colony formation of NIH3T3 and HEK293T cell lines was enhanced >2-fold when cultured in riboflavin-deficient medium for 10-20 generations. Moreover, we observed enhanced subcutaneous tumorigenicity in NU/NU mice following injection of riboflavin-depleted compared with normal HEK293T cells (55.6% compared with 0.0% tumor formation, respectively). Gene expression profiling and gene ontology analysis revealed that riboflavin depletion induced the expression of cell cycle-related genes. Validation experiments also found that riboflavin depletion decreased p21 and p27 protein levels by ∼20%, and increased cell cycle-related and expression-elevated protein in tumor (CREPT) protein expression >2-fold, resulting in cyclin D1 and CDK4 levels being increased ∼1.5-fold, and cell cycle acceleration. We also observed that riboflavin depletion decreased intracellular riboflavin levels by 20% and upregulated expression of riboflavin transporter genes, particularly SLC52A3, and that the changes in CREPT and SLC52A3 correlated with

Improving B-cell depletion in systemic lupus erythematosus and rheumatoid arthritis.

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Mota, Pedro; Reddy, Venkat; Isenberg, David

2017-07-01

Rituximab-based B-cell depletion (BCD) therapy is effective in refractory rheumatoid arthritis (RA) and although used to treat patients with refractory systemic lupus erythematosus (SLE) in routine clinical practice, rituximab failed to meet the primary endpoints in two large randomised controlled trials (RCTs) of non-renal (EXPLORER) and renal (LUNAR) SLE. Areas covered: We review how BCD could be improved to achieve better clinical responses in RA and SLE. Insights into the variability in clinical response to BCD in RA and SLE may help develop new therapeutic strategies. To this end, a literature search was performed using the following terms: rheumatoid arthritis, systemic erythematosus lupus, rituximab and B-cell depletion. Expert commentary: Poor trial design may have, at least partly, contributed to the apparent lack of response to BCD in the two RCTs of patients with SLE. Enhanced B-cell depletion and/or sequential therapy with belimumab may improve clinical response at least in some patients with SLE.

Effects of Thy-1+ cell depletion on the capacity of donor lymphoid cells to induce tolerance across an entire MHC disparity in sublethally irradiated adult hosts

International Nuclear Information System (INIS)

Pierce, G.E.; Watts, L.M.

1989-01-01

Thy-1+ cell depletion with anti-Thy-1.2 mAb and complement markedly reduced the capacity of C57BL/6J, H-2b bone marrow to establish mixed lymphoid chimerism and induce tolerance to C57BL/6J skin grafts across an entire MHC disparity in BALB/c, H-2d hosts conditioned with sublethal, fractionated 7.5 Gy total-body irradiation. In this model tolerance can be transferred to secondary irradiated BALB/c hosts only by cells of C57BL/6J donor, not host, genotype isolated from the spleens of tolerant hosts. Thy-1+ cell depletion abolished the capacity of C57BL/6J donor cells from tolerant BALB/c host spleens to transfer tolerance. The capacity of semiallogeneic BALB/c x C57BL/6J F1, H-2d/b donor BM and spleen cells to induce chimerism and tolerance to C57BL/6J skin grafts in BALB/c parental hosts was also reduced by Thy-1+ cell depletion. Thus the requirement for donor Thy-1+ cells cannot be explained simply on the basis of alloaggression. It is unlikely that the requisite Thy-1+ cells are nonspecific suppressor cells: Thy-1+ cell depletion had no effect on the slight but significant prolongation of third-party C3H/HeJ, H-2k skin grafts in irradiated BALB/c hosts injected with allogeneic C57BL/6J or semiallogeneic BALB/c x C57BL/6J F1 BM compared to irradiated controls injected with medium only. Furthermore, injections of semiallogeneic F1 spleen cells had no significant effect on the survival of the third-party grafts, although these cells were fully capable of inducing tolerance, and their capacity to induce tolerance was significantly reduced by Thy-1+ cell depletion. The requirement for a specific population of lymphoid cells, i.e. Thy-1+, remains unexplained but suggests that donor cells might play a role in the induction or maintenance of tolerance in this model other than merely providing a circulating source of donor antigens

Cellular aging of mitochondrial DNA-depleted cells

International Nuclear Information System (INIS)

Park, Sun Young; Choi, Bongkun; Cheon, Hwanju; Pak, Youngmi Kim; Kulawiec, Mariola; Singh, Keshav K.; Lee, Myung-Shik

2004-01-01

We have reported that mitochondrial DNA-depleted ρ 0 cells are resistant to cell death. Because aged cells have frequent mitochondrial DNA mutations, the resistance of ρ 0 cells against cell death might be related to the apoptosis resistance of aged cells and frequent development of cancers in aged individuals. We studied if ρ 0 cells have features simulating aged cells. SK-Hep1 hepatoma ρ 0 cells showed typical morphology associated with aging such as increased size and elongated appearance. They had increased senescence-associated β-Gal activity, lipofuscin pigment, and plasminogen activator inhibitor-1 expression. Consistent with their decreased proliferation, the expression of mitotic cyclins was decreased and that of cdk inhibitors was increased. Rb hypophosphorylation and decreased telomerase activity were also noted. Features simulating aged cells were also observed in MDA-MB-435 ρ 0 cells. These results support the mitochondrial theory of aging, and suggest that ρ 0 cells could serve as an in vitro model for aged cells

Depleted-Heterojunction Colloidal Quantum Dot Solar Cells

KAUST Repository

Pattantyus-Abraham, Andras G.

2010-06-22

Colloidal quantum dot (CQD) photovoltaics combine low-cost solution processability with quantum size-effect tunability to match absorption with the solar spectrum. Rapid recent advances in CQD photovoltaics have led to impressive 3.6% AM1.5 solar power conversion efficiencies. Two distinct device architectures and operating mechanisms have been advanced. The first-the Schottky device-was optimized and explained in terms of a depletion region driving electron-hole pair separation on the semiconductor side of a junction between an opaque low-work-function metal and a p-type CQD film. The second-the excitonic device-employed a CQD layer atop a transparent conductive oxide (TCO) and was explained in terms of diffusive exciton transport via energy transfer followed by exciton separation at the type-II heterointerface between the CQD film and the TCO. Here we fabricate CQD photovoltaic devices on TCOs and show that our devices rely on the establishment of a depletion region for field-driven charge transport and separation, and that they also exploit the large bandgap of the TCO to improve rectification and block undesired hole extraction. The resultant depletedheterojunction solar cells provide a 5.1% AM1.5 power conversion efficiency. The devices employ infrared-bandgap size-effect-tuned PbS CQDs, enabling broadband harvesting of the solar spectrum. We report the highest opencircuit voltages observed in solid-state CQD solar cells to date, as well as fill factors approaching 60%, through the combination of efficient hole blocking (heterojunction) and very small minority carrier density (depletion) in the large-bandgap moiety. © 2010 American Chemical Society.

Apoptosis and T cell depletion during feline infectious peritonitis

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Horzinek, M.C.; Haagmans, B.L.; Egberink, H.F.

1996-01-01

Cats that have succumbed to feline infectious peritonitis, an immune- mediated disease caused by variants of feline coronaviruses, show apoptosis and T-cell depletion in their lymphoid organs. The ascitic fluid that develops in the course of the condition causes apoptosis in vitro but only in activated T cells. Since feline infectious peritonitis virus does not infect T cells, and viral proteins did not inhibit T-cell proliferation, we postulate that soluble mediators released during the infe...

Auranofin induces apoptosis and necrosis in HeLa cells via oxidative stress and glutathione depletion.

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You, Bo Ra; Shin, Hye Rim; Han, Bo Ram; Kim, Suhn Hee; Park, Woo Hyun

2015-02-01

Auranofin (Au), an inhibitor of thioredoxin reductase, is a known anti‑cancer drug. In the present study, the anti‑growth effect of Au on HeLa cervical cancer cells was examined in association with levels of reactive oxygen species (ROS) and glutathione (GSH). Au inhibited the growth of HeLa cells with an IC50 of ~2 µM at 24 h. This agent induced apoptosis and necrosis, accompanied by the cleavage of poly (ADP‑ribose) polymerase and loss of mitochondrial membrane potential. The pan‑caspase inhibitor, benzyloxycarbonyl‑Val‑Ala‑Asp‑fluoromethylketone, prevented apoptotic cell death and each of the assessed caspase inhibitors inhibited necrotic cell death induced by Au. With respect to the levels of ROS and GSH, Au increased intracellular O2•- in the HeLa cells and induced GSH depletion. The pan‑caspase inhibitor reduced the levels of O2•- and GSH depletion in Au‑treated HeLa cells. The antioxidant, N‑acetyl cysteine, not only attenuated apoptosis and necrosis in the Au‑treated HeLa cells, but also decreased the levels of O2•- and GSH depletion in the cells. By contrast, L‑buthionine sulfoximine, a GSH synthesis inhibitor, intensified cell death O2•- and GSH depletion in the Au‑treated HeLa cells. In conclusion, Au induced apoptosis and necrosis in HeLa cells via the induction of oxidative stress and the depletion of GSH.

Depletion of cutaneous macrophages and dendritic cells promotes growth of basal cell carcinoma in mice.

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König, Simone; Nitzki, Frauke; Uhmann, Anja; Dittmann, Kai; Theiss-Suennemann, Jennifer; Herrmann, Markus; Reichardt, Holger M; Schwendener, Reto; Pukrop, Tobias; Schulz-Schaeffer, Walter; Hahn, Heidi

2014-01-01

Basal cell carcinoma (BCC) belongs to the group of non-melanoma skin tumors and is the most common tumor in the western world. BCC arises due to mutations in the tumor suppressor gene Patched1 (Ptch). Analysis of the conditional Ptch knockout mouse model for BCC reveals that macrophages and dendritic cells (DC) of the skin play an important role in BCC growth restraining processes. This is based on the observation that a clodronate-liposome mediated depletion of these cells in the tumor-bearing skin results in significant BCC enlargement. The depletion of these cells does not modulate Ki67 or K10 expression, but is accompanied by a decrease in collagen-producing cells in the tumor stroma. Together, the data suggest that cutaneous macrophages and DC in the tumor microenvironment exert an antitumor effect on BCC.

Acute dyskerin depletion triggers cellular senescence and renders osteosarcoma cells resistant to genotoxic stress-induced apoptosis

International Nuclear Information System (INIS)

Lin, Ping; Mobasher, Maral E.; Alawi, Faizan

2014-01-01

Highlights: • Dyskerin depletion triggers cellular senescence in U2OS osteosarcoma cells. • Dyskerin-depleted cells are resistant to apoptosis induced by genotoxic stress. • Chromatin relaxation sensitizes dyskerin-depleted cells to apoptosis. - Abstract: Dyskerin is a conserved, nucleolar RNA-binding protein implicated in an increasing array of fundamental cellular processes. Germline mutation in the dyskerin gene (DKC1) is the cause of X-linked dyskeratosis congenita (DC). Conversely, wild-type dyskerin is overexpressed in sporadic cancers, and high-levels may be associated with poor prognosis. It was previously reported that acute loss of dyskerin function via siRNA-mediated depletion slowed the proliferation of transformed cell lines. However, the mechanisms remained unclear. Using human U2OS osteosarcoma cells, we show that siRNA-mediated dyskerin depletion induced cellular senescence as evidenced by proliferative arrest, senescence-associated heterochromatinization and a senescence-associated molecular profile. Senescence can render cells resistant to apoptosis. Conversely, chromatin relaxation can reverse the repressive effects of senescence-associated heterochromatinization on apoptosis. To this end, genotoxic stress-induced apoptosis was suppressed in dyskerin-depleted cells. In contrast, agents that induce chromatin relaxation, including histone deacetylase inhibitors and the DNA intercalator chloroquine, sensitized dyskerin-depleted cells to apoptosis. Dyskerin is a core component of the telomerase complex and plays an important role in telomere homeostasis. Defective telomere maintenance resulting in premature senescence is thought to primarily underlie the pathogenesis of X-linked DC. Since U2OS cells are telomerase-negative, this leads us to conclude that loss of dyskerin function can also induce cellular senescence via mechanisms independent of telomere shortening

The depletion of nuclear glutathione impairs cell proliferation in 3t3 fibroblasts.

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Jelena Markovic

2009-07-01

Full Text Available Glutathione is considered essential for survival in mammalian cells and yeast but not in prokaryotic cells. The presence of a nuclear pool of glutathione has been demonstrated but its role in cellular proliferation and differentiation is still a matter of debate.We have studied proliferation of 3T3 fibroblasts for a period of 5 days. Cells were treated with two well known depleting agents, diethyl maleate (DEM and buthionine sulfoximine (BSO, and the cellular and nuclear glutathione levels were assessed by analytical and confocal microscopic techniques, respectively. Both agents decreased total cellular glutathione although depletion by BSO was more sustained. However, the nuclear glutathione pool resisted depletion by BSO but not with DEM. Interestingly, cell proliferation was impaired by DEM, but not by BSO. Treating the cells simultaneously with DEM and with glutathione ethyl ester to restore intracellular GSH levels completely prevented the effects of DEM on cell proliferation.Our results demonstrate the importance of nuclear glutathione in the control of cell proliferation in 3T3 fibroblasts and suggest that a reduced nuclear environment is necessary for cells to progress in the cell cycle.

Depletion of Pax7+ satellite cells does not affect diaphragm adaptations to running in young or aged mice.

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Murach, Kevin A; Confides, Amy L; Ho, Angel; Jackson, Janna R; Ghazala, Lina S; Peterson, Charlotte A; Dupont-Versteegden, Esther E

2017-10-01

Satellite cell depletion does not affect diaphragm adaptations to voluntary wheel running in young or aged mice. Satellite cell depletion early in life (4 months of age) has minimal effect on diaphragm phenotype by old age (24 months). Prolonged satellite cell depletion in the diaphragm does not result in excessive extracellular matrix accumulation, in contrast to what has been reported in hind limb muscles. Up-regulation of Pax3 mRNA+ cells after satellite cell depletion in young and aged mice suggests that Pax3+ cells may compensate for a loss of Pax7+ satellite cells in the diaphragm. Future investigations should focus on the role of Pax3+ cells in the diaphragm during adaptation to exercise and ageing. Satellite cell contribution to unstressed diaphragm is higher compared to hind limb muscles, which is probably attributable to constant activation of this muscle to drive ventilation. Whether satellite cell depletion negatively impacts diaphragm quantitative and qualitative characteristics under stressed conditions in young and aged mice is unknown. We therefore challenged the diaphragm with prolonged running activity in the presence and absence of Pax7+ satellite cells in young and aged mice using an inducible Pax7 CreER -R26R DTA model. Mice were vehicle (Veh, satellite cell-replete) or tamoxifen (Tam, satellite cell-depleted) treated at 4 months of age and were then allowed to run voluntarily at 6 months (young) and 22 months (aged). Age-matched, cage-dwelling, Veh- and Tam-treated mice without wheel access served as activity controls. Diaphragm muscles were analysed from young (8 months) and aged (24 months) mice. Satellite cell depletion did not alter diaphragm mean fibre cross-sectional area, fibre type distribution or extracellular matrix content in young or aged mice, regardless of running activity. Resting in vivo diaphragm function was also unaffected by satellite cell depletion. Myonuclear density was maintained in young satellite cell-depleted

Internalization of rituximab and the efficiency of B Cell depletion in rheumatoid arthritis and systemic lupus erythematosus.

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Reddy, Venkat; Cambridge, Geraldine; Isenberg, David A; Glennie, Martin J; Cragg, Mark S; Leandro, Maria

2015-05-01

Rituximab, a type I anti-CD20 monoclonal antibody (mAb), induces incomplete B cell depletion in some patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), thus contributing to a poor clinical response. The mechanisms of this resistance remain elusive. The purpose of this study was to determine whether type II mAb are more efficient than type I mAb at depleting B cells from RA and SLE patients, whether internalization influences the efficiency of depletion, and whether Fcγ receptor type IIb (FcγRIIb) and the B cell receptor regulate this internalization process. We used an in vitro whole blood B cell-depletion assay to assess the efficiency of depletion, flow cytometry to study cell surface protein expression, and surface fluorescence-quenching assays to assess rituximab internalization, in samples from patients with RA and patients with SLE. Paired t-test or Mann-Whitney U test was used to compare groups, and Spearman's rank correlation test was used to assess correlation. We found that type II mAb internalized significantly less rituximab than type I mAb and depleted B cells from patients with RA and SLE at least 2-fold more efficiently than type I mAb. Internalization of rituximab was highly variable between patients, was regulated by FcγRIIb, and inversely correlated with cytotoxicity in whole blood B cell-depletion assays. The lowest levels of internalization were seen in IgD- B cells, including postswitched (IgD-CD27+) memory cells. Internalization of type I anti-CD20 mAb was also partially inhibited by anti-IgM stimulation. Variability in internalization of rituximab was observed and was correlated with impaired B cell depletion. Therefore, slower-internalizing type II mAb should be considered as alternative B cell-depleting agents for the treatment of RA and SLE. © 2015 The Authors. Arthritis & Rheumatology is published by Wiley Periodicals, Inc. on behalf of the American College of Rheumatology.

Distinct Biomarker Profiles in Ex Vivo T Cell Depletion Graft Manipulation Strategies: CD34+ Selection versus CD3+/19+ Depletion in Matched Sibling Allogeneic Peripheral Blood Stem Cell Transplantation.

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Cantilena, Caroline R; Ito, Sawa; Tian, Xin; Jain, Prachi; Chinian, Fariba; Anandi, Prathima; Keyvanfar, Keyvan; Draper, Debbie; Koklanaris, Eleftheria; Hauffe, Sara; Superata, Jeanine; Stroncek, David; Muranski, Pawel; Barrett, A John; Battiwalla, Minoo

2018-03-01

Various approaches have been developed for ex vivo T cell depletion in allogeneic stem cell transplantation to prevent graft-versus-host disease (GVHD). Direct comparisons of T cell depletion strategies have not been well studied, however. We evaluated cellular and plasma biomarkers in 2 different graft manipulation strategies, CD3 + CD19 + cell depletion (CD3/19D) versus CD34 + selection (CD34S), and their associations with clinical outcomes. Identical conditions, including the myeloablative preparative regimen, HLA-identical sibling donor, GVHD prophylaxis, and graft source, were used in the 2 cohorts. Major clinical outcomes were similar in the 2 groups in terms of overall survival, nonrelapse mortality, and cumulative incidence of relapse; however, the cumulative incidence of acute GVHD trended to be higher in the CD3/19D cohort compared with the CD34S cohort. A distinct biomarker profile was noted in the CD3/19D cohort: higher levels of ST2, impaired Helios - FoxP3 + Treg reconstitution, and rapid reconstitution of naïve, Th2, and Th17 CD4 cells in the early post-transplantation period. In vitro graft replication studies confirmed that CD3/19D disproportionately depleted Tregs and other CD4 subset repertoires in the graft. This study confirms the utility of biomarker monitoring, which can be directly correlated with biological consequences and possible future therapeutic indications. Published by Elsevier Inc.

Glial-glial and glial-neuronal interfaces in radiation-induced, glia-depleted spinal cord

International Nuclear Information System (INIS)

Gilmore, S.A.; Sims, T.J.

1997-01-01

This review summarises some of the major findings derived from studies using the model of a glia-depleted environment developed and characterised in this laboratory. Glial depletion is achieved by exposure of the immature rodent spinal cord to x-radiation which markedly reduces both astrocyte and oligodendrocyte populations and severely impairs myelination. This glia-depleted, hypomylinated state presents a unique opportunity to examine aspects of spinal cord maturation in the absence of a normal glial population. An associated sequela within 2-3 wk following irradiation is the appearance of Schwann cells in the dorsal portion of the spinal cord. Characteristics of these intraspinal Schwann cells, their patterns of myelination or ensheathment, and their interrelations with the few remaining central glia have been examined. A later sequela is the development of Schwann cells in the ventral aspect of the spinal cord where they occur predominantly in the grey matter. (author)

A sub-population of circulating porcine gammadelta T cells can act as professional antigen presenting cells.

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Takamatsu, H-H; Denyer, M S; Wileman, T E

2002-09-10

A sub-population of circulating porcine gammadelta T cells express cell surface antigens associated with antigen presenting cells (APCs), and are able to take up soluble antigen very effectively. Functional antigen presentation by gammadelta T cells to memory helper T cells was studied by inbred pig lymphocytes immunised with ovalbumin (OVA). After removing all conventional APCs from the peripheral blood of immunised pigs, the remaining lymphocytes still proliferated when stimulated with OVA. When gammadelta T cells were further depleted, OVA specific proliferation was abolished, but reconstitution with gammadelta T cells restored proliferation. The proliferation was blocked by monoclonal antibodies (mAb) against MHC class II or CD4, and by pre-treatment of gammadelta T cells with chloroquine. These results indicate that a sub-population of circulating porcine gammadelta T cells act as APCs and present antigen via MHC class II.

Macrophage depletion and Schwann cell transplantation reduce cyst size after rat contusive spinal cord injury.

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Lee, Yee-Shuan; Funk, Lucy H; Lee, Jae K; Bunge, Mary Bartlett

2018-04-01

Schwann cell transplantation is a promising therapy for the treatment of spinal cord injury (SCI) and is currently in clinical trials. In our continuing efforts to improve Schwann cell transplantation strategies, we sought to determine the combined effects of Schwann cell transplantation with macrophage depletion. Since macrophages are major inflammatory contributors to the acute spinal cord injury, and are the major phagocytic cells, we hypothesized that transplanting Schwann cells after macrophage depletion will improve cell survival and integration with host tissue after SCI. To test this hypothesis, rat models of contusive SCI at thoracic level 8 were randomly subjected to macrophage depletion or not. In rat subjected to macrophage depletion, liposomes filled with clodronate were intraperitoneally injected at 1, 3, 6, 11, and 18 days post injury. Rats not subjected to macrophage depletion were intraperitoneally injected with liposomes filled with phosphate buffered saline. Schwann cells were transplanted 1 week post injury in all rats. Biotinylated dextran amine (BDA) was injected at thoracic level 5 to evalute axon regeneration. The Basso, Beattie, and Bresnahan locomotor test, Gridwalk test, and sensory test using von Frey filaments were performed to assess functional recovery. Immunohistochemistry was used to detect glial fibrillary acidic protein, neurofilament, and green fluorescent protein (GFP), and also to visulize BDA-labelled axons. The GFP labeled Schwann cell and cyst and lesion volumes were quantified using stained slides. The numbers of BDA-positive axons were also quantified. At 8 weeks after Schwann cell transplantation, there was a significant reduction in cyst and lesion volumes in the combined treatment group compared to Schwann cell transplantation alone. These changes were not associated, however, with improved Schwann cell survival, axon growth, or locomotor recovery. Although combining Schwann cell transplantation with macrophage

Macrophage depletion and Schwann cell transplantation reduce cyst size after rat contusive spinal cord injury

Science.gov (United States)

Lee, Yee-Shuan; Funk, Lucy H.; Lee, Jae K.; Bunge, Mary Bartlett

2018-01-01

Schwann cell transplantation is a promising therapy for the treatment of spinal cord injury (SCI) and is currently in clinical trials. In our continuing efforts to improve Schwann cell transplantation strategies, we sought to determine the combined effects of Schwann cell transplantation with macrophage depletion. Since macrophages are major inflammatory contributors to the acute spinal cord injury, and are the major phagocytic cells, we hypothesized that transplanting Schwann cells after macrophage depletion will improve cell survival and integration with host tissue after SCI. To test this hypothesis, rat models of contusive SCI at thoracic level 8 were randomly subjected to macrophage depletion or not. In rat subjected to macrophage depletion, liposomes filled with clodronate were intraperitoneally injected at 1, 3, 6, 11, and 18 days post injury. Rats not subjected to macrophage depletion were intraperitoneally injected with liposomes filled with phosphate buffered saline. Schwann cells were transplanted 1 week post injury in all rats. Biotinylated dextran amine (BDA) was injected at thoracic level 5 to evalute axon regeneration. The Basso, Beattie, and Bresnahan locomotor test, Gridwalk test, and sensory test using von Frey filaments were performed to assess functional recovery. Immunohistochemistry was used to detect glial fibrillary acidic protein, neurofilament, and green fluorescent protein (GFP), and also to visulize BDA-labelled axons. The GFP labeled Schwann cell and cyst and lesion volumes were quantified using stained slides. The numbers of BDA-positive axons were also quantified. At 8 weeks after Schwann cell transplantation, there was a significant reduction in cyst and lesion volumes in the combined treatment group compared to Schwann cell transplantation alone. These changes were not associated, however, with improved Schwann cell survival, axon growth, or locomotor recovery. Although combining Schwann cell transplantation with macrophage

Macrophage depletion and Schwann cell transplantation reduce cyst size after rat contusive spinal cord injury

Directory of Open Access Journals (Sweden)

Yee-Shuan Lee

2018-01-01

Full Text Available Schwann cell transplantation is a promising therapy for the treatment of spinal cord injury (SCI and is currently in clinical trials. In our continuing efforts to improve Schwann cell transplantation strategies, we sought to determine the combined effects of Schwann cell transplantation with macrophage depletion. Since macrophages are major inflammatory contributors to the acute spinal cord injury, and are the major phagocytic cells, we hypothesized that transplanting Schwann cells after macrophage depletion will improve cell survival and integration with host tissue after SCI. To test this hypothesis, rat models of contusive SCI at thoracic level 8 were randomly subjected to macrophage depletion or not. In rat subjected to macrophage depletion, liposomes filled with clodronate were intraperitoneally injected at 1, 3, 6, 11, and 18 days post injury. Rats not subjected to macrophage depletion were intraperitoneally injected with liposomes filled with phosphate buffered saline. Schwann cells were transplanted 1 week post injury in all rats. Biotinylated dextran amine (BDA was injected at thoracic level 5 to evalute axon regeneration. The Basso, Beattie, and Bresnahan locomotor test, Gridwalk test, and sensory test using von Frey filaments were performed to assess functional recovery. Immunohistochemistry was used to detect glial fibrillary acidic protein, neurofilament, and green fluorescent protein (GFP, and also to visulize BDA-labelled axons. The GFP labeled Schwann cell and cyst and lesion volumes were quantified using stained slides. The numbers of BDA-positive axons were also quantified. At 8 weeks after Schwann cell transplantation, there was a significant reduction in cyst and lesion volumes in the combined treatment group compared to Schwann cell transplantation alone. These changes were not associated, however, with improved Schwann cell survival, axon growth, or locomotor recovery. Although combining Schwann cell transplantation with

Disruption of microtubule network rescues aberrant actin comets in dynamin2-depleted cells.

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Yuji Henmi

Full Text Available A large GTPase dynamin, which is required for endocytic vesicle formation, regulates the actin cytoskeleton through its interaction with cortactin. Dynamin2 mutants impair the formation of actin comets, which are induced by Listeria monocytogenes or phosphatidylinositol-4-phosphate 5-kinase. However, the role of dynamin2 in the regulation of the actin comet is still unclear. Here we show that aberrant actin comets in dynamin2-depleted cells were rescued by disrupting of microtubule networks. Depletion of dynamin2, but not cortactin, significantly reduced the length and the speed of actin comets induced by Listeria. This implies that dynamin2 may regulate the actin comet in a cortactin-independent manner. As dynamin regulates microtubules, we investigated whether perturbation of microtubules would rescue actin comet formation in dynamin2-depleted cells. Treatment with taxol or colchicine created a microtubule-free space in the cytoplasm, and made no difference between control and dynamin2 siRNA cells. This suggests that the alteration of microtubules by dynamin2 depletion reduced the length and the speed of the actin comet.

Depletion of cellular poly (A) binding protein prevents protein synthesis and leads to apoptosis in HeLa cells

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Thangima Zannat, Mst.; Bhattacharjee, Rumpa B. [Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada N1G2W1 (Canada); Bag, Jnanankur, E-mail: jbag@uoguelph.ca [Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada N1G2W1 (Canada)

2011-05-13

Highlights: {yields} Depletion of cellular PABP level arrests mRNA translation in HeLa cells. {yields} PABP knock down leads to apoptotic cell death. {yields} PABP depletion does not affect transcription. {yields} PABP depletion does not lead to nuclear accumulation of mRNA. -- Abstract: The cytoplasmic poly (A) binding protein (PABP) is important in mRNA translation and stability. In yeast, depletion of PABP leads to translation arrest. Similarly, the PABP gene in Drosophila is important for proper development. It is however uncertain, whether mammalian PABP is essential for mRNA translation. Here we showed the effect of PABP depletion on mRNA metabolism in HeLa cells by using a small interfering RNA. Our results suggest that depletion of PABP prevents protein synthesis and consequently leads to cell death through apoptosis. Interestingly, no detectable effect of PABP depletion on transcription, transport and stability of mRNA was observed.

Depletion of cellular poly (A) binding protein prevents protein synthesis and leads to apoptosis in HeLa cells

International Nuclear Information System (INIS)

Thangima Zannat, Mst.; Bhattacharjee, Rumpa B.; Bag, Jnanankur

2011-01-01

Highlights: → Depletion of cellular PABP level arrests mRNA translation in HeLa cells. → PABP knock down leads to apoptotic cell death. → PABP depletion does not affect transcription. → PABP depletion does not lead to nuclear accumulation of mRNA. -- Abstract: The cytoplasmic poly (A) binding protein (PABP) is important in mRNA translation and stability. In yeast, depletion of PABP leads to translation arrest. Similarly, the PABP gene in Drosophila is important for proper development. It is however uncertain, whether mammalian PABP is essential for mRNA translation. Here we showed the effect of PABP depletion on mRNA metabolism in HeLa cells by using a small interfering RNA. Our results suggest that depletion of PABP prevents protein synthesis and consequently leads to cell death through apoptosis. Interestingly, no detectable effect of PABP depletion on transcription, transport and stability of mRNA was observed.

Automated red blood cell depletion in ABO incompatible grafts in the pediatric setting.

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Del Fante, Claudia; Scudeller, Luigia; Recupero, Santina; Viarengo, Gianluca; Boghen, Stella; Gurrado, Antonella; Zecca, Marco; Seghatchian, Jerard; Perotti, Cesare

2017-12-01

Bone marrow ABO incompatible transplantations require graft manipulation prior to infusion to avoid potentially lethal side effects. We analyzed the influence of pre-manipulation factors (temperature at arrival, transit time, time of storage at 4°C until processing and total time from collection to red blood cell depletion) on the graft quality of 21 red blood cell depletion procedures in ABO incompatible pediatric transplants. Bone marrow collections were processed using the Spectra Optia ® (Terumo BCT) automated device. Temperature at arrival ranged between 4°C and 6°C, median transit time was 9.75h (range 0.33-28), median time of storage at 4°-6°C until processing was 1.8h (range 0.41-18.41) and median time from collection to RBC depletion was 21h (range1-39.4). Median percentage of red blood cell depletion was 97.7 (range 95.4-98.5), median mononuclear cells recovery was 92.2% (range 40-121.2), median CD34+ cell recovery was 93% (range 69.9-161.2), median cell viability was 97.7% (range 94-99.3) and median volume reduction was 83.9% (range 82-92). Graft quality was not significantly different between BM units median age. Our preliminary data show that when all good manifacturing practices are respected the post-manipulation graft quality is excellent also for those units processed after 24h. Copyright © 2017 Elsevier Ltd. All rights reserved.

Experimental and analytical study of oxygen depletion in stirred cell suspensions

International Nuclear Information System (INIS)

Whillans, D.W.; Rauth, A.M.

1980-01-01

The determination and maintenance of constant low but non-zero levels of oxygen is critical in the study of the radiation chemical interactions of nitroimidazoles in mammalian cells in vitro. As well, many of these chemicals have increased toxicity toward hypoxic compared to aerobic cells, although absolute hypoxia probably is not required. Both of these phenomena must be investigated in systems where significant consumption of oxygen takes place, either through radiation depletion or by cellular metabolism. In this paper an analysis has been made of the form of oxygen depletion in stirred cell suspensions with overlying gas phase, and it has been found to conform to the relationship (C[t] - C/sub infinity/) = (C[0] - C/sub infinity/) exp(-k 1 t), where C/sub infinity/ = C/sub g/ - R/k 1 . Here C[t] is the oxygen tension throughout the solution; C/sub g/, the equivalent level in the overlying gas phase; R (concentration units per sec), the depletion rate; k 1 (sec/sup -1/), a physical constant independent of oxygen concentration and depletion rate; and C/sub infinity/, the oxygen level in solution approached at long times. This relationship has been confirmed in detail using a Clark-type oxygen sensor and a high-stability amplifier design due to Koch. Since oxygen levels down to a few hundred parts per million can be determined with accuracy, it has been possible to measure precisely the oxygen levels present in our experimental systems. Implications of these results for the interpretation of data obtained in stirred cell suspension with overlying gas phase under conditions of consumption are discussed

Immunity to Schistosoma mansoni in congenitally athymic, irradiated and mast cell-depleted rats

International Nuclear Information System (INIS)

Ford, M.J.; Bickle, Q.D.; Taylor, M.G.

1987-01-01

Immunity to Schistosoma mansoni was investigated in congenitally athymic (Nu/Nu) rats, irradiated rats and in mast cell-depleted rats. Nu/Nu rats failed to develop significant resistance following vaccination with irradiated cercariae, although Nu/Nu recipients of serum from vaccinated Fischer rats (VRS) manifested resistance comparable to heterozygous controls, suggesting that T-cells were required in the induction of resistance but were not involved in the efferent arm of antibody-dependent elimination. Radiosensitive cells (including eosinophils, basophils, neutrophils, lymphocytes and mast cells) were apparently not essential for the antibody-dependent elimination of lung or post-lung stages since irradiated (700-750 rad.) recipients of VRS manifested comparable degrees of resistance to unirradiated controls in spite of a greater than 85% reduction in total blood leucocyte counts after irradiation. Depletion of 99% of tissue mast cells by treatment of rats with Compound 48/80 had no significant effect on the attrition of a challenge infection in rats rendered immune by vaccination with irradiated cercariae or by transfer of VRS. However, there was a significant increase in worm recovery in unimmunized and mast cell-depleted or irradiated rats, indicating that mast cells and perhaps other radio-isotope sensitive cells may be involved in innate resistance. (author)

Immunity to Schistosoma mansoni in congenitally athymic, irradiated and mast cell-depleted rats

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Ford, M.J.; Bickle, Q.D.; Taylor, M.G.

1987-04-01

Immunity to Schistosoma mansoni was investigated in congenitally athymic (Nu/Nu) rats, irradiated rats and in mast cell-depleted rats. Nu/Nu rats failed to develop significant resistance following vaccination with irradiated cercariae, although Nu/Nu recipients of serum from vaccinated Fischer rats (VRS) manifested resistance comparable to heterozygous controls, suggesting that T-cells were required in the induction of resistance but were not involved in the efferent arm of antibody-dependent elimination. Radiosensitive cells (including eosinophils, basophils, neutrophils, lymphocytes and mast cells) were apparently not essential for the antibody-dependent elimination of lung or post-lung stages since irradiated (700-750 rad.) recipients of VRS manifested comparable degrees of resistance to unirradiated controls in spite of a greater than 85% reduction in total blood leucocyte counts after irradiation. Depletion of 99% of tissue mast cells by treatment of rats with Compound 48/80 had no significant effect on the attrition of a challenge infection in rats rendered immune by vaccination with irradiated cercariae or by transfer of VRS. However, there was a significant increase in worm recovery in unimmunized and mast cell-depleted or irradiated rats, indicating that mast cells and perhaps other radio-isotope sensitive cells may be involved in innate resistance.

In vivo T cell depletion regulates resistance and morbidity in murine schistosomiasis

International Nuclear Information System (INIS)

Phillips, S.M.; Linette, G.P.; Doughty, B.L.; Byram, J.E.; Von Lichtenberg, F.

1987-01-01

These studies assessed the roles of subpopulations of T lymphocytes in inducing and modulating resistance to schistosomiasis and thereby influencing subsequent morbidity. C57BL/6 mice were depleted in vivo of Lyt-1+, Lyt-2+, and L3T4+ cells by the daily administration of monoclonal antibodies. The development of protective immunity, induced by exposure to irradiated Schistosoma mansoni cercariae as expressed in depleted animals, was compared to that demonstrated in undepleted, normal, and congenitally athymic C57BL/6 mice. The development of morbidity was determined by spleen weight, portal pressure and reticuloendothelial system activity. The results indicated that depletion of specific subpopulations of T lymphocytes minimally affected the primary development of parasites; however, depletion strongly influenced the development of resistance to the parasite and subsequent morbidity due to infection. Depletion of T lymphocytes by anti-Lyt-1+ or anti-L3T4+ antibody decreased the development of resistance, antibody and delayed-type hypersensitivity directed against schistosome antigens. Morbidity due to disease was increased. Depletion of Lyt-2+ cells produced opposite changes with augmented resistance and reduced morbidity. Congenitally athymic mice developed minimal resistance and morbidity. Moreover, resistance was inversely related to the morbidity shown by a given animal. These studies indicate that the development of protective immunity to S. mansoni cercariae is regulated by discrete subpopulations of T lymphocytes. The feasibility of decreasing morbidity by increasing specific immunologically mediated resistance is suggested

Single-cell time-lapse analysis of depletion of the universally conserved essential protein YgjD

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Ackermann Martin

2011-05-01

Full Text Available Abstract Background The essential Escherichia coli gene ygjD belongs to a universally conserved group of genes whose function has been the focus of a number of recent studies. Here, we put ygjD under control of an inducible promoter, and used time-lapse microscopy and single cell analysis to investigate the phenotypic consequences of the depletion of YgjD protein from growing cells. Results We show that loss of YgjD leads to a marked decrease in cell size and termination of cell division. The transition towards smaller size occurs in a controlled manner: cell elongation and cell division remain coupled, but cell size at division decreases. We also find evidence that depletion of YgjD leads to the synthesis of the intracellular signaling molecule (pppGpp, inducing a cellular reaction resembling the stringent response. Concomitant deletion of the relA and spoT genes - leading to a strain that is uncapable of synthesizing (pppGpp - abrogates the decrease in cell size, but does not prevent termination of cell division upon YgjD depletion. Conclusions Depletion of YgjD protein from growing cells leads to a decrease in cell size that is contingent on (pppGpp, and to a termination of cell division. The combination of single-cell timelapse microscopy and statistical analysis can give detailed insights into the phenotypic consequences of the loss of essential genes, and can thus serve as a new tool to study the function of essential genes.

Age-related mitochondrial DNA depletion and the impact on pancreatic Beta cell function.

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Nile, Donna L; Brown, Audrey E; Kumaheri, Meutia A; Blair, Helen R; Heggie, Alison; Miwa, Satomi; Cree, Lynsey M; Payne, Brendan; Chinnery, Patrick F; Brown, Louise; Gunn, David A; Walker, Mark

2014-01-01

Type 2 diabetes is characterised by an age-related decline in insulin secretion. We previously identified a 50% age-related decline in mitochondrial DNA (mtDNA) copy number in isolated human islets. The purpose of this study was to mimic this degree of mtDNA depletion in MIN6 cells to determine whether there is a direct impact on insulin secretion. Transcriptional silencing of mitochondrial transcription factor A, TFAM, decreased mtDNA levels by 40% in MIN6 cells. This level of mtDNA depletion significantly decreased mtDNA gene transcription and translation, resulting in reduced mitochondrial respiratory capacity and ATP production. Glucose-stimulated insulin secretion was impaired following partial mtDNA depletion, but was normalised following treatment with glibenclamide. This confirms that the deficit in the insulin secretory pathway precedes K+ channel closure, indicating that the impact of mtDNA depletion is at the level of mitochondrial respiration. In conclusion, partial mtDNA depletion to a degree comparable to that seen in aged human islets impaired mitochondrial function and directly decreased insulin secretion. Using our model of partial mtDNA depletion following targeted gene silencing of TFAM, we have managed to mimic the degree of mtDNA depletion observed in aged human islets, and have shown how this correlates with impaired insulin secretion. We therefore predict that the age-related mtDNA depletion in human islets is not simply a biomarker of the aging process, but will contribute to the age-related risk of type 2 diabetes.

Histone h1 depletion impairs embryonic stem cell differentiation.

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Zhang, Yunzhe; Cooke, Marissa; Panjwani, Shiraj; Cao, Kaixiang; Krauth, Beth; Ho, Po-Yi; Medrzycki, Magdalena; Berhe, Dawit T; Pan, Chenyi; McDevitt, Todd C; Fan, Yuhong

2012-01-01

Pluripotent embryonic stem cells (ESCs) are known to possess a relatively open chromatin structure; yet, despite efforts to characterize the chromatin signatures of ESCs, the role of chromatin compaction in stem cell fate and function remains elusive. Linker histone H1 is important for higher-order chromatin folding and is essential for mammalian embryogenesis. To investigate the role of H1 and chromatin compaction in stem cell pluripotency and differentiation, we examine the differentiation of embryonic stem cells that are depleted of multiple H1 subtypes. H1c/H1d/H1e triple null ESCs are more resistant to spontaneous differentiation in adherent monolayer culture upon removal of leukemia inhibitory factor. Similarly, the majority of the triple-H1 null embryoid bodies (EBs) lack morphological structures representing the three germ layers and retain gene expression signatures characteristic of undifferentiated ESCs. Furthermore, upon neural differentiation of EBs, triple-H1 null cell cultures are deficient in neurite outgrowth and lack efficient activation of neural markers. Finally, we discover that triple-H1 null embryos and EBs fail to fully repress the expression of the pluripotency genes in comparison with wild-type controls and that H1 depletion impairs DNA methylation and changes of histone marks at promoter regions necessary for efficiently silencing pluripotency gene Oct4 during stem cell differentiation and embryogenesis. In summary, we demonstrate that H1 plays a critical role in pluripotent stem cell differentiation, and our results suggest that H1 and chromatin compaction may mediate pluripotent stem cell differentiation through epigenetic repression of the pluripotency genes.

Depletion of CD11c⁺ cells in the CD11c.DTR model drives expansion of unique CD64⁺ Ly6C⁺ monocytes that are poised to release TNF-α.

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Sivakumaran, Shivajanani; Henderson, Stephen; Ward, Sophie; Sousa, Pedro Santos E; Manzo, Teresa; Zhang, Lei; Conlan, Thomas; Means, Terry K; D'Aveni, Maud; Hermine, Olivier; Rubio, Marie-Thérèse; Chakraverty, Ronjon; Bennett, Clare L

2016-01-01

Dendritic cells (DCs) play a vital role in innate and adaptive immunities. Inducible depletion of CD11c(+) DCs engineered to express a high-affinity diphtheria toxin receptor has been a powerful tool to dissect DC function in vivo. However, despite reports showing that loss of DCs induces transient monocytosis, the monocyte population that emerges and the potential impact of monocytes on studies of DC function have not been investigated. We found that depletion of CD11c(+) cells from CD11c.DTR mice induced the expansion of a variant CD64(+) Ly6C(+) monocyte population in the spleen and blood that was distinct from conventional monocytes. Expansion of CD64(+) Ly6C(+) monocytes was independent of mobilization from the BM via CCR2 but required the cytokine, G-CSF. Indeed, this population was also expanded upon exposure to exogenous G-CSF in the absence of DC depletion. CD64(+) Ly6C(+) monocytes were characterized by upregulation of innate signaling apparatus despite the absence of inflammation, and an increased capacity to produce TNF-α following LPS stimulation. Thus, depletion of CD11c(+) cells induces expansion of a unique CD64(+) Ly6C(+) monocyte population poised to synthesize TNF-α. This finding will require consideration in experiments using depletion strategies to test the role of CD11c(+) DCs in immunity. © 2015 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Apoptosis and T cell depletion during feline infectious peritonitis

NARCIS (Netherlands)

Horzinek, M.C.; Haagmans, B.L.; Egberink, H.F.

1996-01-01

Cats that have succumbed to feline infectious peritonitis, an immune- mediated disease caused by variants of feline coronaviruses, show apoptosis and T-cell depletion in their lymphoid organs. The ascitic fluid that develops in the course of the condition causes apoptosis in vitro but only in

Long-term safety of rituximab induced peripheral B-cell depletion in autoimmune neurological diseases.

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Anza B Memon

Full Text Available B-cells play a pivotal role in several autoimmune diseases, including patients with immune-mediated neurological disorders (PIMND, such as neuromyelitis optica (NMO, multiple sclerosis (MS, and myasthenia gravis (MG. Targeting B-cells has been an effective approach in ameliorating both central and peripheral autoimmune diseases. However, there is a paucity of literature on the safety of continuous B-cell depletion over a long period of time.The aim of this study was to examine the long-term safety, incidence of infections, and malignancies in subjects receiving continuous therapy with a B-cell depleting agent rituximab over at least 3 years or longer.This was a retrospective study involving PIMND who received continuous cycles of rituximab infusions every 6 to 9 months for up to 7 years. The incidence of infection related adverse events (AE, serious adverse events (SAE, and malignancies were observed.There were a total of 32 AE and 4 SAE with rituximab treatment. The 3 SAE were noted after 9 cycles (48 months and 1 SAE was observed after 11 cycles (60 months of rituximab. There were no cases of Progressive multifocal leukoencephalopathy (PML and malignancies observed throughout the treatment period. Rituximab was well tolerated without any serious infusion reactions. Also, rituximab was found to be beneficial in treating PIMND over a 7-year period.This study demonstrates that long-term depletion of peripheral B-cells appears safe and efficacious in treating PIMND. Longer and larger prospective studies with rituximab are needed to carefully ascertain risks associated with chronic B-cell depletion, including malignancies. Recognizing that this is a small, retrospective study, such data nonetheless complement the growing literature documenting the safety and tolerability of B-cell depleting agents in neurological diseases.

Differential effects of chronic monocyte depletion on macrophage populations

International Nuclear Information System (INIS)

Volkman, A.; Chang, N.C.; Strausbauch, P.H.; Morahan, P.S.

1983-01-01

The administration of the bone-seeking isotope, 89 Sr, to mice results in severe monocytopenia without any apparent effect on the numbers of resident peritoneal macrophages (M luminal diameter). An explanation for this dichotomy was sought by determining whether the residual blood monocytes were still an effective source of M luminal diameter after 89 Sr treatment. Stem cell enumeration showed that a 90% fall in bone marrow macrophage colony-forming cells after 89 Sr was accompanied by a 10-fold rise in splenic M-CFC. Splenectomy performed before 89 Sr treatment, however, resulted in little additional monocytopenia and had no affect on the numbers of resident peritoneal M luminal diameter even when sampling was extended to 31 days, an interval beyond the accepted half-time for peritoneal M luminal diameter. Intraperitoneal injections of thioglycollate or Corynebacterium parvum elicited few or no monocyte-M luminal diameter during respective intervals of 4 and 7 days. Elicitation with thioglycollate was attempted in tritiated thymidine-labeled mice 26 days after 89 Sr. Four days later only a 2-fold increase in labeled peritoneal M luminal diameter was found in the 89 Sr-treated mice compared with a 150-fold increase in the controls. Studies of the ectoenzymes 5'-nucleotidase, alkaline phosphodiesterase I, and leucine aminopeptidase in such elicitation experiments suggested that the observed changes in activities reflected the direct stimulation of resident M luminal diameter rather than monocyte immigration. Overall, the results indicate that treatment with 89 Sr distinguishes two large populations of M luminal diameter on the basis of their dependence on bone marrow. M luminal diameter of inflammation reflect the monocytopenia and are severely and rapidly depleted by such treatment

Effect of alpha-tocopherol and alpha-tocopheryl quinone on the radiosensitivity of thiol-depleted mammalian cells

International Nuclear Information System (INIS)

Hodgkiss, R.J.; Stratford, M.R.; Watfa, R.R.

1989-01-01

The effect of hypoxic cell radiosensitizers is increased when mammalian cells are depleted of endogenous glutathione by buthionine sulphoximine pre-treatment in vitro; a similar gain has not been observed in tumors in vivo despite evidence of glutathione depletion in vivo following buthionine sulphoximine treatment. However, concentrations of biological reducing agents other than glutathione were not measured in the in vivo experiments. Other reducing agents found in tumors include alpha-tocopherol, which reduces the sensitizing efficiency of nitro-aromatic sensitizers in thiol-depleted mammalian cells. These data suggest that the failure to observe large gains in misonidazole sensitizing efficiency in thiol-depleted tumors in vivo may be due, in part, to the presence of biological reducing agents such as alpha-tocopherol

Examination of the health status of populations from depleted-uranium-contaminated regions

International Nuclear Information System (INIS)

Milacic, Snezana; Petrovic, Dragana; Jovicic, Dubravka; Kovacevic, Radomir; Simic, Jadranko

2004-01-01

During the NATO air strikes on the Federal Republic of Yugoslavia (Serbia and Montenegro) in 1999, depleted-uranium ammunition was used on 112 locations, mainly Kosovo, in the south of Serbia, and one location in Montenegro. Blood samples of residents from depleted-uranium-contaminated areas were gathered and blood cell and chromosomal aberrations were analyzed. During the last 3 years blood samples from 21 residents of Kosovo (Strpce), from 29 residents from the south of Serbia (the Vranje and Bujanovac regions), and from 19 technical television workers from the site of Pljackovica, in the vicinity of Vranje, were collected. Blood samples from 33 residents of central Serbia and 46 occupational workers exposed to X-rays were used as controls. All subjects studied were without any clinical symptoms of disease. The examinations included general clinical assessment; urine samples for α-and γ-spectrometry analysis; complete blood counts; ratio-percentages of blood cells in stained (Giemsa) capillary smears, individual leukocyte line elements; morphological changes observed under a microscope; the presence of immature forms or blasts; and leukocyte enzyme activity [alkaline phosphatase leukocyte (APL)]. Chromosomal aberrations were evaluated in 200 peripheral blood lymphocytes in mitosis. An increased incidence of rogue cells and chromosomal aberrations was found in the blood of the residents of Vranje and Bujanovac, but this was below the incidence of chromosomal aberrations in individuals occupationally exposed to ionizing irradiation. Blast cells were not found. Blood counts were decreased in only a few samples, while morphological changes of both nuclei and cytoplasm were marked in individuals in south and central Serbia. Enzymatic activity (as measured by the APL score) was decreased in samples with chromosomal aberrations and cyto-morphological changes in subjects from the south of Serbia. The contamination level measured by this examination was low. Because of

Depletion of T lymphocytes is correlated with response to temozolomide in melanoma patients

DEFF Research Database (Denmark)

Iversen, Trine Zeeberg; Brimnes, Marie Klinge; Nikolajsen, Kirsten

2013-01-01

Therapeutic strategies to deplete lymphocytes, especially regulatory T cells, in cancer patients have been proposed to increase the benefits of (immuno)chemotherapy. In this study, we explored the influence of temozolomide (TMZ) on different T-cell populations and addressed if the depletion of CD4......(+) T cells would be associated to the clinical benefits of TMZ. Patients were treated with TMZ (150 mg/m(2) daily, every two weeks on a four-week schedule) until disease progression. Changes in T-lymphocyte subsets were characterized by flow cytometry. All patients enrolled in this study had...

Effect of polyamine depletion on DNA damage and repair following UV irradiation of HeLa cells

International Nuclear Information System (INIS)

Snyder, R.D.; Sunkara, P.S.

1990-01-01

Treatment of HeLa cells with the polyamine biosynthesis inhibitors, methylglyoxal bis(guanylhydrazone) (MGBG), difluoromethylornithine (DFMO) or a combination of the two, resulted in reduction in cellular polyamine levels. Analysis of UV light-induced DNA damage and repair in these polyamine depleted cells revealed distinct differences in the repair process relative to that seen in cells possessing a normal polyamine complement. Observed patterns of differential polyamine depletion by DFMO and MGBG, and partial reversal of repair inhibition by polyamine supplementation, suggest that polyamine depletion per se, rather than some secondary effect of inhibitor treatment, is responsible for the inhibition of repair. (author)

Effect of polyamine depletion on DNA damage and repair following UV irradiation of HeLa cells

Energy Technology Data Exchange (ETDEWEB)

Snyder, R.D.; Sunkara, P.S. (Merrell Dow Research Inst., Cincinnati, OH (USA))

1990-09-01

Treatment of HeLa cells with the polyamine biosynthesis inhibitors, methylglyoxal bis(guanylhydrazone) (MGBG), difluoromethylornithine (DFMO) or a combination of the two, resulted in reduction in cellular polyamine levels. Analysis of UV light-induced DNA damage and repair in these polyamine depleted cells revealed distinct differences in the repair process relative to that seen in cells possessing a normal polyamine complement. Observed patterns of differential polyamine depletion by DFMO and MGBG, and partial reversal of repair inhibition by polyamine supplementation, suggest that polyamine depletion per se, rather than some secondary effect of inhibitor treatment, is responsible for the inhibition of repair. (author).

Mycobacterial antigens stimulate rheumatoid mononuclear cells to cartilage proteoglycan depletion

NARCIS (Netherlands)

Wilbrink, B.; Bijlsma, J. W.; Huber-Bruning, O.; van Roy, J. L.; den Otter, W.; van Eden, W.

1990-01-01

In a coculture with porcine articular cartilage explants unstimulated blood mononuclear cells (BMC) from patients with rheumatoid arthritis (RA), but not from healthy controls, induced proteoglycan depletion of dead cartilage. Specific stimulation of the RA BMC with Mycobacterium tuberculosis (MT),

In situ depletion of CD4(+) T cells in human skin by Zanolimumab

DEFF Research Database (Denmark)

Villadsen, L.S.; Skov, L.; Dam, T.N.

2007-01-01

CD4(+) T cells, in activated or malignant form, are involved in a number of diseases including inflammatory skin diseases such as psoriasis, and T cell lymphomas such as the majority of cutaneous T cell lymphomas (CTCL). Targeting CD4 with an antibody that inhibits and/or eliminates disease......-driving T cells in situ may therefore be a useful approach in the treatment of inflammatory and malignant skin diseases. Depletion of CD4(+) T cells in intact inflamed human skin tissue by Zanolimumab, a fully human therapeutic monoclonal antibody (IgG1, kappa) against CD4, was studied in a human psoriasis......(+), but not CD8(+) CD3(+) T cells. The capacity of Zanolimumab to deplete the CD4(+) T cells in the skin may be of importance in diseases where CD4(+) T cells play a central role. Indeed, in a phase II clinical trial Zanolimumab has shown a dose-dependent clinical response in patients with CTCL and the antibody...

Oval cell response is attenuated by depletion of liver resident macrophages in the 2-AAF/partial hepatectomy rat.

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Shuai Xiang

Full Text Available BACKGROUND/AIMS: Macrophages are known to play an important role in hepatocyte mediated liver regeneration by secreting inflammatory mediators. However, there is little information available on the role of resident macrophages in oval cell mediated liver regeneration. In the present study we aimed to investigate the role of macrophages in oval cell expansion induced by 2-acetylaminofluorene/partial hepatectomy (2-AAF/PH in rats. METHODOLOGY/PRINCIPAL FINDINGS: We depleted macrophages in the liver of 2-AAF/PH treated rats by injecting liposome encapsulated clodronate 48 hours before PH. Regeneration of remnant liver mass, as well as proliferation and differentiation of oval cells were measured. We found that macrophage-depleted rats suffered higher mortality and liver transaminase levels. We also showed that depletion of macrophages yielded a significant decrease of EPCAM and PCK positive oval cells in immunohistochemical stained liver sections 9 days after PH. Meanwhile, oval cell differentiation was also attenuated as a result of macrophage depletion, as large foci of small basophilic hepatocytes were observed by day 9 following hepatectomy in control rats whereas they were almost absent in macrophage depleted rats. Accordingly, real-time polymerase chain reaction analysis showed lower expression of albumin mRNA in macrophage depleted livers. Then we assessed whether macrophage depletion may affect hepatic production of stimulating cytokines for liver regeneration. We showed that macrophage-depletion significantly inhibited hepatic expression of tumor necrosis factor-α and interleukin-6, along with a lack of signal transducer and activator of transcription 3 phosphorylation during the early period following hepatectomy. CONCLUSIONS: These data indicate that macrophages play an important role in oval cell mediated liver regeneration in the 2-AAF/PH model.

Serum depletion induces changes in protein expression in the trophoblast-derived cell line HTR-8/SVneo.

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Novoa-Herran, Susana; Umaña-Perez, Adriana; Canals, Francesc; Sanchez-Gomez, Myriam

2016-01-01

How nutrition and growth factor restriction due to serum depletion affect trophoblast function remains poorly understood. We performed a proteomic differential study of the effects of serum depletion on a first trimester human immortalized trophoblast cell line. The viability of HTR-8/SVneo trophoblast cells in culture with 0, 0.5 and 10 % fetal bovine serum (FBS) were assayed via MTT at 24, 48 and 64 h. A comparative proteomic analysis of the cells grown with those FBS levels for 24 h was performed using two-dimensional electrophoresis (2DE), followed by mass spectrometry for protein spot identification, and a database search and bioinformatics analysis of the expressed proteins. Differential spots were identified using the Kolmogorov-Smirnov test ( n  = 3, significance level 0.10, D > 0.642) and/or ANOVA ( n  = 3, p  depletion differentially affect cell growth and protein expression. Differential expression was seen in 25 % of the protein spots grown with 0.5 % FBS and in 84 % of those grown with 0 % FBS, using 10 % serum as the physiological control. In 0.5 % FBS, this difference was related with biological processes typically affected by the serum, such as cell cycle, regulation of apoptosis and proliferation. In addition to these changes, in the serum-depleted proteome we observed downregulation of keratin 8, and upregulation of vimentin, the glycolytic enzymes enolase and pyruvate kinase (PKM2) and tumor progression-related inosine-5'-monophosphate dehydrogenase 2 (IMPDH2) enzyme. The proteins regulated by total serum depletion, but not affected by growth in 0.5 % serum, are members of the glycolytic and nucleotide metabolic pathways and the epithelial-to-mesenchymal transition (EMT), suggesting an adaptive switch characteristic of malignant cells. This comparative proteomic analysis and the identified proteins are the first evidence of a protein expression response to serum depletion in a trophoblast cell model. Our results show that

Selective Depletion of αβ T Cells and B Cells for Human Leukocyte Antigen-Haploidentical Hematopoietic Stem Cell Transplantation. A Three-Year Follow-Up of Procedure Efficiency.

Science.gov (United States)

Li Pira, Giuseppina; Malaspina, David; Girolami, Elia; Biagini, Simone; Cicchetti, Elisabetta; Conflitti, Gianpiero; Broglia, Manuel; Ceccarelli, Stefano; Lazzaro, Stefania; Pagliara, Daria; Meschini, Antonella; Bertaina, Alice; Montanari, Mauro; Locatelli, Franco

2016-11-01

HLA-haploidentical family donors represent a valuable option for children requiring allogeneic hematopoietic stem cell transplantation (HSCT). Because graft-versus-host diseases (GVHD) is a major complication of HLA-haploidentical HSCT because of alloreactive T cells in the graft, different methods have been used for ex vivo T cell depletion. Removal of donor αβ T cells, the subset responsible for GVHD, and of B cells, responsible for post-transplantation lymphoproliferative disorders, have been recently developed for HLA-haploidentical HSCT. This manipulation preserves, in addition to CD34 +  progenitors, natural killer, γδ T, and monocytes/dendritic cells, contributing to anti-leukemia activity and protection against infections. We analyzed depletion efficiency and cell yield in 200 procedures performed in the last 3 years at our center. Donors underwent CD34 +   hematopoietic stem cell (HSC) peripheral blood mobilization with granulocyte colony-stimulating factor (G-CSF). Poor CD34 +  cell mobilizers (48 of 189, 25%) received plerixafor in addition to G-CSF. Aphereses containing a median of 52.5 × 10 9 nucleated cells and 494 × 10 6 CD34 +  HSC were manipulated using the CliniMACS device. In comparison to the initial product, αβ T cell depletion produced a median 4.1-log reduction (range, 3.1 to 5.5) and B cell depletion led to a median 3.4-log reduction (range, 2.0 to 4.7). Graft products contained a median of 18.5 × 10 6 CD34 +  HSC/kg recipient body weight, with median values of residual αβ T cells and B cells of 29 × 10 3 /kg and 33 × 10 3 /kg, respectively. Depletion efficiency monitored at 6-month intervals demonstrated steady performance, while improved recovery of CD34 +  cells was observed after the first year (P = .0005). These data indicate that αβ T cell and B cell depletion of HSC grafts from HLA-haploidentical donors was efficient and reproducible. Copyright © 2016 The American Society for Blood and Marrow

Glioblastoma formation from cell population depleted of Prominin1-expressing cells.

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Kenji Nishide

2009-08-01

Full Text Available Prominin1 (Prom1, also known as CD133 in human has been widely used as a marker for cancer stem cells (CSCs, which self-renew and are tumorigenic, in malignant tumors including glioblastoma multiforme (GBM. However, there is other evidence showing that Prom1-negative cancer cells also form tumors in vivo. Thus it remains controversial whether Prom1 is a bona fide marker for CSCs. To verify if Prom1-expressing cells are essential for tumorigenesis, we established a mouse line, whose Prom1-expressing cells can be eliminated conditionally by a Cre-inducible DTA gene on the Prom1 locus together with a tamoxifen-inducible CreER(TM, and generated glioma-initiating cells (GICs-LD by overexpressing both the SV40 Large T antigen and an oncogenic H-Ras(L61 in neural stem cells of the mouse line. We show here that the tamoxifen-treated GICs-LD (GICs-DTA form tumor-spheres in culture and transplantable GBM in vivo. Thus, our studies demonstrate that Prom1-expressing cells are dispensable for gliomagenesis in this mouse model.

Exacerbation of spontaneous autoimmune nephritis following regulatory T cell depletion in B cell lymphoma 2-interacting mediator knock-out mice.

Science.gov (United States)

Wang, Y M; Zhang, G Y; Wang, Y; Hu, M; Zhou, J J; Sawyer, A; Cao, Q; Wang, Y; Zheng, G; Lee, V W S; Harris, D C H; Alexander, S I

2017-05-01

Regulatory T cells (T regs ) have been recognized as central mediators for maintaining peripheral tolerance and limiting autoimmune diseases. The loss of T regs or their function has been associated with exacerbation of autoimmune disease. However, the temporary loss of T regs in the chronic spontaneous disease model has not been investigated. In this study, we evaluated the role of T regs in a novel chronic spontaneous glomerulonephritis model of B cell lymphoma 2-interacting mediator (Bim) knock-out mice by transient depleting T regs . Bim is a pro-apoptotic member of the B cell lymphoma 2 (Bcl-2) family. Bim knock-out (Bim -/- ) mice fail to delete autoreactive T cells in thymus, leading to chronic spontaneous autoimmune kidney disease. We found that T reg depletion in Bim -/- mice exacerbated the kidney injury with increased proteinuria, impaired kidney function, weight loss and greater histological injury compared with wild-type mice. There was a significant increase in interstitial infiltrate of inflammatory cells, antibody deposition and tubular damage. Furthermore, the serum levels of cytokines interleukin (IL)-2, IL-4, IL-6, IL-10, IL-17α, interferon (IFN)-γ and tumour necrosis factor (TNF)-α were increased significantly after T reg depletion in Bim -/- mice. This study demonstrates that transient depletion of T regs leads to enhanced self-reactive T effector cell function followed by exacerbation of kidney disease in the chronic spontaneous kidney disease model of Bim-deficient mice. © 2017 British Society for Immunology.

Depletion of the AP-1 repressor JDP2 induces cell death similar to apoptosis

DEFF Research Database (Denmark)

Lerdrup, Mads; Holmberg, Christian Henrik; Dietrich, Nikolaj

2005-01-01

JDP2 is a ubiquitously expressed nuclear protein that efficiently represses the activity of the transcription factor AP-1. Thus far, all studies of JDP2 function have relied on the ectopic expression of the protein. In this study, we use a different approach: depletion of JDP2 from cells. Specific...... depletion of JDP2 resulted in p53-independent cell death that resembles apoptosis and was evident at 72 h. The death mechanism was caspase dependent as the cells could be rescued by treatment with caspase inhibitor zVAD. Our studies suggest that JDP2 functions as a general survival protein, not only...

Depletion of intrinsic expression of Interleukin-8 in prostate cancer cells causes cell cycle arrest, spontaneous apoptosis and increases the efficacy of chemotherapeutic drugs

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Lokeshwar Bal L

2009-07-01

Full Text Available Abstract Background The progression of all cancers is characterized by increased-cell proliferation and decreased-apoptosis. The androgen-independent prostate cancer (AIPC is the terminal stage of the disease. Many chemokines and cytokines are suspects to cause this increased tumor cell survival that ultimately leads to resistance to therapy and demise of the host. The AIPC cells, but not androgen-responsive cells, constitutively express abundant amount of the pro-inflammatory chemokine, Interleukin-8 (IL-8. The mechanism of IL-8 mediated survival and therapeutic resistance in AIPC cells is unclear at present. The purpose of this report is to show the pervasive role of IL-8 in malignant progression of androgen-independent prostate cancer (AIPC and to provide a potential new therapeutic avenue, using RNA interference. Results The functional consequence of IL-8 depletion in AIPC cells was investigated by RNA interference in two IL-8 secreting AIPC cell lines, PC-3 and DU145. The non-IL-8 secreting LNCaP and LAPC-4 cells served as controls. Cells were transfected with RISC-free siRNA (control or validated-pool of IL-8 siRNA. Transfection with 50 nM IL-8 siRNA caused >95% depletion of IL-8 mRNA and >92% decrease in IL-8 protein. This reduction in IL-8 led to cell cycle arrest at G1/S boundary and decreases in cell cycle-regulated proteins: Cyclin D1 and Cyclin B1 (both decreased >50% and inhibition of ERK1/2 activity by >50%. Further, the spontaneous apoptosis was increased by >43% in IL-8 depleted cells, evidenced by increases in caspase-9 activation and cleaved-PARP. IL-8 depletion caused significant decreases in anti-apoptotic proteins, BCL-2, BCL-xL due to decrease in both mRNA and post-translational stability, and increased levels of pro-apoptotic BAX and BAD proteins. More significantly, depletion of intracellular IL-8 increased the cytotoxic activity of multiple chemotherapeutic drugs. Specifically, the cytotoxicity of Docetaxel

Depletion of dendritic cells enhances innate anti-bacterial host defense through modulation of phagocyte homeostasis.

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Stella E Autenrieth

2012-02-01

Full Text Available Dendritic cells (DCs as professional antigen-presenting cells play an important role in the initiation and modulation of the adaptive immune response. However, their role in the innate immune response against bacterial infections is not completely defined. Here we have analyzed the role of DCs and their impact on the innate anti-bacterial host defense in an experimental infection model of Yersinia enterocolitica (Ye. We used CD11c-diphtheria toxin (DT mice to deplete DCs prior to severe infection with Ye. DC depletion significantly increased animal survival after Ye infection. The bacterial load in the spleen of DC-depleted mice was significantly lower than that of control mice throughout the infection. DC depletion was accompanied by an increase in the serum levels of CXCL1, G-CSF, IL-1α, and CCL2 and an increase in the numbers of splenic phagocytes. Functionally, splenocytes from DC-depleted mice exhibited an increased bacterial killing capacity compared to splenocytes from control mice. Cellular studies further showed that this was due to an increased production of reactive oxygen species (ROS by neutrophils. Adoptive transfer of neutrophils from DC-depleted mice into control mice prior to Ye infection reduced the bacterial load to the level of Ye-infected DC-depleted mice, suggesting that the increased number of phagocytes with additional ROS production account for the decreased bacterial load. Furthermore, after incubation with serum from DC-depleted mice splenocytes from control mice increased their bacterial killing capacity, most likely due to enhanced ROS production by neutrophils, indicating that serum factors from DC-depleted mice account for this effect. In summary, we could show that DC depletion triggers phagocyte accumulation in the spleen and enhances their anti-bacterial killing capacity upon bacterial infection.

Erythrocyte depletion from bone marrow: performance evaluation after 50 clinical-scale depletions with Spectra Optia BMC.

Science.gov (United States)

Kim-Wanner, Soo-Zin; Bug, Gesine; Steinmann, Juliane; Ajib, Salem; Sorg, Nadine; Poppe, Carolin; Bunos, Milica; Wingenfeld, Eva; Hümmer, Christiane; Luxembourg, Beate; Seifried, Erhard; Bonig, Halvard

2017-08-11

Red blood cell (RBC) depletion is a standard graft manipulation technique for ABO-incompatible bone marrow (BM) transplants. The BM processing module for Spectra Optia, "BMC", was previously introduced. We here report the largest series to date of routine quality data after performing 50 clinical-scale RBC-depletions. Fifty successive RBC-depletions from autologous (n = 5) and allogeneic (n = 45) BM transplants were performed with the Spectra Optia BMC apheresis suite. Product quality was assessed before and after processing for volume, RBC and leukocyte content; RBC-depletion and stem cell (CD34+ cells) recovery was calculated there from. Clinical engraftment data were collected from 26/45 allogeneic recipients. Median RBC removal was 98.2% (range 90.8-99.1%), median CD34+ cell recovery was 93.6%, minimum recovery being 72%, total product volume was reduced to 7.5% (range 4.7-23.0%). Products engrafted with expected probability and kinetics. Performance indicators were stable over time. Spectra Optia BMC is a robust and efficient technology for RBC-depletion and volume reduction of BM, providing near-complete RBC removal and excellent CD34+ cell recovery.

Metabolic Response to NAD Depletion across Cell Lines Is Highly Variable.

Science.gov (United States)

Xiao, Yang; Kwong, Mandy; Daemen, Anneleen; Belvin, Marcia; Liang, Xiaorong; Hatzivassiliou, Georgia; O'Brien, Thomas

2016-01-01

Nicotinamide adenine dinucleotide (NAD) is a cofactor involved in a wide range of cellular metabolic processes and is a key metabolite required for tumor growth. NAMPT, nicotinamide phosphoribosyltransferase, which converts nicotinamide (NAM) to nicotinamide mononucleotide (NMN), the immediate precursor of NAD, is an attractive therapeutic target as inhibition of NAMPT reduces cellular NAD levels and inhibits tumor growth in vivo. However, there is limited understanding of the metabolic response to NAD depletion across cancer cell lines and whether all cell lines respond in a uniform manner. To explore this we selected two non-small cell lung carcinoma cell lines that are sensitive to the NAMPT inhibitor GNE-617 (A549, NCI-H1334), one that shows intermediate sensitivity (NCI-H441), and one that is insensitive (LC-KJ). Even though NAD was reduced in all cell lines there was surprising heterogeneity in their metabolic response. Both sensitive cell lines reduced glycolysis and levels of di- and tri-nucleotides and modestly increased oxidative phosphorylation, but they differed in their ability to combat oxidative stress. H1334 cells activated the stress kinase AMPK, whereas A549 cells were unable to activate AMPK as they contain a mutation in LKB1, which prevents activation of AMPK. However, A549 cells increased utilization of the Pentose Phosphate pathway (PPP) and had lower reactive oxygen species (ROS) levels than H1334 cells, indicating that A549 cells are better able to modulate an increase in oxidative stress. Inherent resistance of LC-KJ cells is associated with higher baseline levels of NADPH and a delayed reduction of NAD upon NAMPT inhibition. Our data reveals that cell lines show heterogeneous response to NAD depletion and that the underlying molecular and genetic framework in cells can influence the metabolic response to NAMPT inhibition.

Metabolic Response to NAD Depletion across Cell Lines Is Highly Variable.

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Yang Xiao

Full Text Available Nicotinamide adenine dinucleotide (NAD is a cofactor involved in a wide range of cellular metabolic processes and is a key metabolite required for tumor growth. NAMPT, nicotinamide phosphoribosyltransferase, which converts nicotinamide (NAM to nicotinamide mononucleotide (NMN, the immediate precursor of NAD, is an attractive therapeutic target as inhibition of NAMPT reduces cellular NAD levels and inhibits tumor growth in vivo. However, there is limited understanding of the metabolic response to NAD depletion across cancer cell lines and whether all cell lines respond in a uniform manner. To explore this we selected two non-small cell lung carcinoma cell lines that are sensitive to the NAMPT inhibitor GNE-617 (A549, NCI-H1334, one that shows intermediate sensitivity (NCI-H441, and one that is insensitive (LC-KJ. Even though NAD was reduced in all cell lines there was surprising heterogeneity in their metabolic response. Both sensitive cell lines reduced glycolysis and levels of di- and tri-nucleotides and modestly increased oxidative phosphorylation, but they differed in their ability to combat oxidative stress. H1334 cells activated the stress kinase AMPK, whereas A549 cells were unable to activate AMPK as they contain a mutation in LKB1, which prevents activation of AMPK. However, A549 cells increased utilization of the Pentose Phosphate pathway (PPP and had lower reactive oxygen species (ROS levels than H1334 cells, indicating that A549 cells are better able to modulate an increase in oxidative stress. Inherent resistance of LC-KJ cells is associated with higher baseline levels of NADPH and a delayed reduction of NAD upon NAMPT inhibition. Our data reveals that cell lines show heterogeneous response to NAD depletion and that the underlying molecular and genetic framework in cells can influence the metabolic response to NAMPT inhibition.

Advances in colloidal quantum dot solar cells: The depleted-heterojunction device

International Nuclear Information System (INIS)

Kramer, Illan J.; Pattantyus-Abraham, Andras G.; Barkhouse, Aaron R.; Wang, Xihua; Konstantatos, Gerasimos; Debnath, Ratan; Levina, Larissa; Raabe, Ines; Nazeeruddin, Md. K.; Graetzel, Michael; Sargent, Edward H.

2011-01-01

Colloidal quantum dot (CQD) photovoltaics combine low-cost solution processibility with quantum size-effect tunability to match absorption with the solar spectrum. Recent advances in CQD photovoltaics have led to 3.6% AM1.5 solar power conversion efficiencies. Here we report CQD photovoltaic devices on transparent conductive oxides and show that our devices rely on the establishment of a depletion region for field-driven charge transport and separation. The resultant depleted-heterojunction solar cells provide a 5.1% AM1.5 power conversion efficiency. The devices employ infrared-bandgap size-effect-tuned PbS colloidal quantum dots, enabling broadband harvesting of the solar spectrum.

Depletion of Mediator Kinase Module Subunits Represses Superenhancer-Associated Genes in Colon Cancer Cells.

Science.gov (United States)

Kuuluvainen, Emilia; Domènech-Moreno, Eva; Niemelä, Elina H; Mäkelä, Tomi P

2018-06-01

In cancer, oncogene activation is partly mediated by acquired superenhancers, which therefore represent potential targets for inhibition. Superenhancers are enriched for BRD4 and Mediator, and both BRD4 and the Mediator MED12 subunit are disproportionally required for expression of superenhancer-associated genes in stem cells. Here we show that depletion of Mediator kinase module subunit MED12 or MED13 together with MED13L can be used to reduce expression of cancer-acquired superenhancer genes, such as the MYC gene, in colon cancer cells, with a concomitant decrease in proliferation. Whereas depletion of MED12 or MED13/MED13L caused a disproportional decrease of superenhancer gene expression, this was not seen with depletion of the kinases cyclin-dependent kinase 9 (CDK8) and CDK19. MED12-MED13/MED13L-dependent superenhancer genes were coregulated by β-catenin, which has previously been shown to associate with MED12. Importantly, β-catenin depletion caused reduced binding of MED12 at the MYC superenhancer. The effect of MED12 or MED13/MED13L depletion on cancer-acquired superenhancer gene expression was more specific than and partially distinct from that of BRD4 depletion, with the most efficient inhibition seen with combined targeting. These results identify a requirement of MED12 and MED13/MED13L for expression of acquired superenhancer genes in colon cancer, implicating these Mediator subunits as potential therapeutic targets for colon cancer, alone or together with BRD4. Copyright © 2018 American Society for Microbiology.

Optical assessment of phytoplankton nutrient depletion

DEFF Research Database (Denmark)

Heath, M.R.; Richardson, Katherine; Kiørboe, Thomas

1990-01-01

The ratio of light absorption at 480 and 665 nm by 90% acetone extracts of marine phytoplankton pigments has been examined as a potential indicator of phytoplankton nutritional status in both laboratory and field studies. The laboratory studies demonstrated a clear relationship between nutritiona......-replete and nutrient-depleted cells. The field data suggest that the absorption ratio may be a useful indicator of nutritional status of natural phytoplankton populations, and can be used to augment the interpretation of other data....

Bacterial reduction by cell salvage washing and leukocyte depletion filtration.

Science.gov (United States)

Waters, Jonathan H; Tuohy, Marion J; Hobson, Donna F; Procop, Gary

2003-09-01

Blood conservation techniques are being increasingly used because of the increased cost and lack of availability of allogeneic blood. Cell salvage offers great blood savings opportunities but is thought to be contraindicated in a number of areas (e.g., blood contaminated with bacteria). Several outcome studies have suggested the safety of this technique in trauma and colorectal surgery, but many practitioners are still hesitant to apply cell salvage in the face of frank bacterial contamination. This study was undertaken to assess the efficacy of bacterial removal when cell salvage was combined with leukocyte depletion filtration. Expired packed erythrocytes were obtained and inoculated with a fixed amount of a stock bacteria (Escherichia coli American Type Culture Collections [ATCC] 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 29213, or Bacteroides fragilis ATCC 25285) in amounts ranging from 2,000 to 4,000 colony forming units/ml. The blood was processed via a cell salvage machine. The washed blood was then filtered using a leukocyte reduction filter. The results for blood taken during each step of processing were compared using a repeated-measures design. Fifteen units of blood were contaminated with each of the stock bacteria. From the prewash sample to the postfiltration sample, 99.0%, 99.6%, 100%, and 97.6% of E. coli, S. aureus, P. aeruginosa, and B. fragilis were removed, respectively. Significant but not complete removal of contaminating bacteria was seen. An increased level of patient safety may be added to cell salvage by including a leukocyte depletion filter when salvaging blood that might be grossly contaminated with bacteria.

M cells and granular mononuclear cells in Peyer's patch domes of mice depleted of their lymphocytes by total lymphoid irradiation

International Nuclear Information System (INIS)

Ermak, T.H.; Steger, H.J.; Strober, S.; Owen, R.L.

1989-01-01

The cytoarchitecture of Peyer's patches that were depleted of their lymphocytes by total lymphoid irradiation (TLI) was examined with particular attention to the effects on M cells in the follicle epithelium and on mononuclear cells in follicle domes underlying the epithelium. Five-month-old, specific pathogen-free Balb/c mice were irradiated with 200-250 rad/day, five times a week to a total dose of 3400-4250, and their Peyer's patches were either fixed for electron microscopy or frozen for immunohistochemistry 1-4 days after completion of irradiation. Control mice were examined at the same time intervals. Follicle domes of TLI mice had approximately one fourth the epithelial surface area of domes of control mice. Within the epithelium, lymphoid cells were virtually depleted after TLI, and yet the epithelium contained M cells. In control mice, most M cells were accompanied by lymphoid cells in invaginations of the apical-lateral cell membrane. In TLI mice, most M cells did not have such apical-lateral invaginations and were columnar shaped. Other than lacking lymphocytes, these cells appeared to be mature M cells. Some M cells did have lymphoid cells or granular mononuclear cells below their basal membranes, adjacent to the basal lamina. Below the epithelium, the proportion of granular mononuclear cells was greatly increased following TLI. The retention of M cells and the increase in proportion of granular mononuclear cells in follicle domes are consistent with selective depletion of lymphocytes following TLI. Persistence of M cells without lymphocytic invaginations after TLI suggests that M cells can differentiate in the absence of, or at least in the presence of very few, lymphocytes, and that invagination by lymphocytes is not necessary to maintain mature M cell morphology

Effects of taurine depletion on cell migration and NCAM expression in cultures of dissociated mouse cerebellum and N2A cells

DEFF Research Database (Denmark)

Maar, T E; Lund, Trine Meldgaard; Gegelashvili, G

1998-01-01

Cultures of dissociated cerebellum from 5- to 6-day-old mice as well as of the N2A neuronal cell line were exposed to guanidino ethane sulfonate (GES, 2-5 mM) to reduce the cellular taurine content. Control cultures were kept in culture medium or medium containing 2-5 mM GES plus 2-5 mM taurine...... to restore the intracellular taurine content. Taurine depletion led to changes in the expression of certain splice variants of NCAM mRNA such as the AAG and the VASE containing forms, while no differences were seen in the expression of the three forms of NCAM protein. In the N2A cells taurine depletion led...... to a decreased migration rate of the cells. The results suggest that the reduced migration rate of neurons caused by taurine depletion may be correlated to changes in expression of certain adhesion molecules such as NCAM. Moreover, taurine appears to be involved in regulation of transcription processes....

Inhibition of X-ray induced DNA strand break repair in polyamine-depleted HeLa cells

Energy Technology Data Exchange (ETDEWEB)

Snyder, R.D.

1989-05-01

Treatment of HeLa cells with the polyamine biosynthesis inhibitors, alpha-difluoromethylornithine (DFMO) or methylglyoxal bis(guanylhydrazone) (MGBG), results in, depending on the conditions, partial or complete depletion of the cellular polyamines: putrescine, spermidine and spermine. In this compromised state cells exhibited a distinct deficiency in repair of X-ray-induced DNA strand breaks. The half-time for return of normal DNA sedimentation following 1.6 Gy was 9.5 min for untreated control cells and 22, 32 and 50 min for cells treated with MGBG, DFMO+MGBG and DFMO, respectively. Normal repair kinetics were restored to these cells upon a short incubation in media containing all three polyamines. The rapid early phase of repair following higher X-ray doses (16 Gy) was also delayed in polyamine-depleted cells but later repair occurring 1-4 h post-irradiation, representing chromatin reconstitution, was apparently normal. (author).

Inhibition of X-ray induced DNA strand break repair in polyamine-depleted HeLa cells

International Nuclear Information System (INIS)

Snyder, R.D.

1989-01-01

Treatment of HeLa cells with the polyamine biosynthesis inhibitors, alpha-difluoromethylornithine (DFMO) or methylglyoxal bis(guanylhydrazone) (MGBG), results in, depending on the conditions, partial or complete depletion of the cellular polyamines: putrescine, spermidine and spermine. In this compromised state cells exhibited a distinct deficiency in repair of X-ray-induced DNA strand breaks. The half-time for return of normal DNA sedimentation following 1.6 Gy was 9.5 min for untreated control cells and 22, 32 and 50 min for cells treated with MGBG, DFMO+MGBG and DFMO, respectively. Normal repair kinetics were restored to these cells upon a short incubation in media containing all three polyamines. The rapid early phase of repair following higher X-ray doses (16 Gy) was also delayed in polyamine-depleted cells but later repair occurring 1-4 h post-irradiation, representing chromatin reconstitution, was apparently normal. (author)

Addition of an indoleamine 2,3,-dioxygenase inhibitor to B cell-depletion therapy blocks autoreactive B cell activation and recurrence of arthritis in K/BxN mice.

Science.gov (United States)

Pigott, Elizabeth; Mandik-Nayak, Laura

2012-07-01

To define the role of indoleamine 2,3-dioxygenase (IDO) in driving pathogenic B cell responses that lead to arthritis and to determine if inhibitors of the IDO pathway can be used in conjunction with therapeutic B cell depletion to prevent the reemergence of autoantibodies and arthritis following reconstitution of the B cell repertoire. Immunoglobulin-transgenic mice were treated with the IDO inhibitor 1-methyltryptophan (1-MT) and monitored for the extent of autoreactive B cell activation. Arthritic K/BxN mice were treated with B cell depletion alone or in combination with 1-MT. Mice were monitored for the presence of autoantibody-secreting cells, inflammatory cytokines, and joint inflammation. Treatment with 1-MT did not affect the initial activation or survival of autoreactive B cells, but it did inhibit their ability to differentiate into autoantibody-secreting cells. Treatment with anti-CD20 depleted the B cell repertoire and attenuated arthritis symptoms; however, the arthritis symptoms rapidly returned as B cells repopulated the repertoire. Administration of 1-MT prior to B cell repopulation prevented the production of autoantibodies and inflammatory cytokines and flare of arthritis symptoms. IDO activity is essential for the differentiation of autoreactive B cells into antibody-secreting cells, but it is not necessary for their initial stages of activation. Addition of 1-MT to therapeutic B cell depletion prevents the differentiation of autoantibody-secreting cells and the recurrence of autoimmune arthritis following reconstitution of the B cell repertoire. These data suggest that IDO inhibitors could be used in conjunction with B cell depletion as an effective cotherapeutic strategy in the treatment of rheumatoid arthritis. Copyright © 2012 by the American College of Rheumatology.

Understanding the slow depletion of memory CD4+ T cells in HIV infection.

Directory of Open Access Journals (Sweden)

Andrew Yates

2007-05-01

Full Text Available The asymptomatic phase of HIV infection is characterised by a slow decline of peripheral blood CD4(+ T cells. Why this decline is slow is not understood. One potential explanation is that the low average rate of homeostatic proliferation or immune activation dictates the pace of a "runaway" decline of memory CD4(+ T cells, in which activation drives infection, higher viral loads, more recruitment of cells into an activated state, and further infection events. We explore this hypothesis using mathematical models.Using simple mathematical models of the dynamics of T cell homeostasis and proliferation, we find that this mechanism fails to explain the time scale of CD4(+ memory T cell loss. Instead it predicts the rapid attainment of a stable set point, so other mechanisms must be invoked to explain the slow decline in CD4(+ cells.A runaway cycle in which elevated CD4(+ T cell activation and proliferation drive HIV production and vice versa cannot explain the pace of depletion during chronic HIV infection. We summarize some alternative mechanisms by which the CD4(+ memory T cell homeostatic set point might slowly diminish. While none are mutually exclusive, the phenomenon of viral rebound, in which interruption of antiretroviral therapy causes a rapid return to pretreatment viral load and T cell counts, supports the model of virus adaptation as a major force driving depletion.

Transient Treg depletion enhances therapeutic anti‐cancer vaccination

Science.gov (United States)

Aston, Wayne J.; Chee, Jonathan; Khong, Andrea; Cleaver, Amanda L.; Solin, Jessica N.; Ma, Shaokang; Lesterhuis, W. Joost; Dick, Ian; Holt, Robert A.; Creaney, Jenette; Boon, Louis; Robinson, Bruce; Lake, Richard A.

2016-01-01

Abstract Introduction Regulatory T cells (Treg) play an important role in suppressing anti‐ immunity and their depletion has been linked to improved outcomes. To better understand the role of Treg in limiting the efficacy of anti‐cancer immunity, we used a Diphtheria toxin (DTX) transgenic mouse model to specifically target and deplete Treg. Methods Tumor bearing BALB/c FoxP3.dtr transgenic mice were subjected to different treatment protocols, with or without Treg depletion and tumor growth and survival monitored. Results DTX specifically depleted Treg in a transient, dose‐dependent manner. Treg depletion correlated with delayed tumor growth, increased effector T cell (Teff) activation, and enhanced survival in a range of solid tumors. Tumor regression was dependent on Teffs as depletion of both CD4 and CD8 T cells completely abrogated any survival benefit. Severe morbidity following Treg depletion was only observed, when consecutive doses of DTX were given during peak CD8 T cell activation, demonstrating that Treg can be depleted on multiple occasions, but only when CD8 T cell activation has returned to base line levels. Finally, we show that even minimal Treg depletion is sufficient to significantly improve the efficacy of tumor‐peptide vaccination. Conclusions BALB/c.FoxP3.dtr mice are an ideal model to investigate the full therapeutic potential of Treg depletion to boost anti‐tumor immunity. DTX‐mediated Treg depletion is transient, dose‐dependent, and leads to strong anti‐tumor immunity and complete tumor regression at high doses, while enhancing the efficacy of tumor‐specific vaccination at low doses. Together this data highlight the importance of Treg manipulation as a useful strategy for enhancing current and future cancer immunotherapies. PMID:28250921

Submolecular regulation of cell transformation by deuterium depleting water exchange reactions in the tricarboxylic acid substrate cycle.

Science.gov (United States)

Boros, László G; D'Agostino, Dominic P; Katz, Howard E; Roth, Justine P; Meuillet, Emmanuelle J; Somlyai, Gábor

2016-02-01

The naturally occurring isotope of hydrogen ((1)H), deuterium ((2)H), could have an important biological role. Deuterium depleted water delays tumor progression in mice, dogs, cats and humans. Hydratase enzymes of the tricarboxylic acid (TCA) cycle control cell growth and deplete deuterium from redox cofactors, fatty acids and DNA, which undergo hydride ion and hydrogen atom transfer reactions. A model is proposed that emphasizes the terminal complex of mitochondrial electron transport chain reducing molecular oxygen to deuterium depleted water (DDW); this affects gluconeogenesis as well as fatty acid oxidation. In the former, the DDW is thought to diminish the deuteration of sugar-phosphates in the DNA backbone, helping to preserve stability of hydrogen bond networks, possibly protecting against aneuploidy and resisting strand breaks, occurring upon exposure to radiation and certain anticancer chemotherapeutics. DDW is proposed here to link cancer prevention and treatment using natural ketogenic diets, low deuterium drinking water, as well as DDW production as the mitochondrial downstream mechanism of targeted anti-cancer drugs such as Avastin and Glivec. The role of (2)H in biology is a potential missing link to the elusive cancer puzzle seemingly correlated with cancer epidemiology in western populations as a result of excessive (2)H loading from processed carbohydrate intake in place of natural fat consumption. Published by Elsevier Ltd.

RETRACTED: Advances in colloidal quantum dot solar cells: The depleted-heterojunction device

KAUST Repository

Kramer, Illan J.; Pattantyus-Abraham, Andras G.; Barkhouse, Aaron R.; Wang, Xihua; Konstantatos, Gerasimos; Debnath, Ratan; Levina, Larissa; Raabe, Ines; Nazeeruddin, Md. K.; Grä tzel, Michael; Sargent, Edward H.

2011-01-01

Colloidal quantum dot (CQD) photovoltaics combine low-cost solution processibility with quantum size-effect tunability to match absorption with the solar spectrum. Recent advances in CQD photovoltaics have led to 3.6% AM1.5 solar power conversion efficiencies. Here we report CQD photovoltaic devices on transparent conductive oxides and show that our devices rely on the establishment of a depletion region for field-driven charge transport and separation. The resultant depleted-heterojunction solar cells provide a 5.1% AM1.5 power conversion efficiency. The devices employ infrared-bandgap size-effect-tuned PbS colloidal quantum dots, enabling broadband harvesting of the solar spectrum. © 2010 Elsevier B.V.

RETRACTED: Advances in colloidal quantum dot solar cells: The depleted-heterojunction device

KAUST Repository

Kramer, Illan J.

2011-08-01

Colloidal quantum dot (CQD) photovoltaics combine low-cost solution processibility with quantum size-effect tunability to match absorption with the solar spectrum. Recent advances in CQD photovoltaics have led to 3.6% AM1.5 solar power conversion efficiencies. Here we report CQD photovoltaic devices on transparent conductive oxides and show that our devices rely on the establishment of a depletion region for field-driven charge transport and separation. The resultant depleted-heterojunction solar cells provide a 5.1% AM1.5 power conversion efficiency. The devices employ infrared-bandgap size-effect-tuned PbS colloidal quantum dots, enabling broadband harvesting of the solar spectrum. © 2010 Elsevier B.V.

Optimal Allocation of Sampling Effort in Depletion Surveys

Science.gov (United States)

We consider the problem of designing a depletion or removal survey as part of estimating animal abundance for populations with imperfect capture or detection rates. In a depletion survey, animals are captured from a given area, counted, and withheld from the population. This proc...

Lymphocyte depletion in thymic nurse cells: a tool to identify in situ lympho-epithelial complexes having thymic nurse cell characteristics

NARCIS (Netherlands)

Leene, W.; de Waal Malefijt, R.; Roholl, P. J.; Hoeben, K. A.

1988-01-01

In situ pre-existing complexes of epithelial cells and thymocytes having thymic nurse cell characteristics were visualized in the murine thymus cortex using dexamethasone as a potent killer of cortisone-sensitive thymocytes. The degradation and subsequent depletion of cortisone-sensitive thymocytes

Spatially selective depleting tumor-associated negative regulatory T-(Treg) cells with near infrared photoimmunotherapy (NIR-PIT): A new cancer immunotherapy (Conference Presentation)

Science.gov (United States)

Kobayashi, Hisataka

2017-02-01

Near infrared photoimmunotherapy (NIR-PIT) is a new type of molecularly-targeted photo-therapy based on conjugating a near infrared silica-phthalocyanine dye, IR700, to a monoclonal antibody (MAb) targeting target-specific cell-surface molecules. When exposed to NIR light, the conjugate rapidly induces a highly-selective cell death only in receptor-positive, MAb-IR700-bound cells. Current immunotherapies for cancer seek to modulate the balance among different immune cell populations, thereby promoting anti-tumor immune responses. However, because these are systemic therapies, they often cause treatment-limiting autoimmune adverse effects. It would be ideal to manipulate the balance between suppressor and effector cells within the tumor without disturbing homeostasis elsewhere in the body. CD4+CD25+Foxp3+ regulatory T cells (Tregs) are well-known immune-suppressor cells that play a key role in tumor immuno-evasion and have been the target of systemic immunotherapies. We used CD25-targeted NIR-PIT to selectively deplete Tregs, thus activating CD8+ T and NK cells and restoring local anti-tumor immunity. This not only resulted in regression of the treated tumor but also induced responses in separate untreated tumors of the same cell-line derivation. We conclude that CD25-targeted NIR-PIT causes spatially selective depletion of Tregs, thereby providing an alternative approach to cancer immunotherapy that can treat not only local tumors but also distant metastatic tumors.

Prevention of immunodeficiency virus induced CD4+ T-cell depletion by prior infection with a non-pathogenic virus

International Nuclear Information System (INIS)

TerWee, Julie A.; Carlson, Jennifer K.; Sprague, Wendy S.; Sondgeroth, Kerry S.; Shropshire, Sarah B.; Troyer, Jennifer L.; VandeWoude, Sue

2008-01-01

Immune dysregulation initiated by a profound loss of CD4+ T-cells is fundamental to HIV-induced pathogenesis. Infection of domestic cats with a non-pathogenic lentivirus prevalent in the puma (puma lentivirus, PLV or FIV PCO ) prevented peripheral blood CD4+ T-cell depletion caused by subsequent virulent FIV infection. Maintenance of this critical population was not associated with a significant decrease in FIV viremia, lending support to the hypothesis that direct viral cytopathic effect is not the primary cause of immunodeficiency. Although this approach was analogous to immunization with a modified live vaccine, correlates of immunity such as a serum-neutralizing antibody or virus-specific T-cell proliferative response were not found in protected animals. Differences in cytokine transcription profile, most notably in interferon gamma, were observed between the protected and unprotected groups. These data provide support for the importance of non-adaptive enhancement of the immune response in the prevention of CD4+ T-cell loss

Early depletion of proliferating B cells of germinal center in rapidly progressive simian immunodeficiency virus infection

International Nuclear Information System (INIS)

Zhang Zhiqiang; Casimiro, Danilo R.; Schleif, William A.; Chen, Minchun; Citron, Michael; Davies, Mary-Ellen; Burns, Janine; Liang, Xiaoping; Fu, Tong-Ming; Handt, Larry; Emini, Emilio A.; Shiver, John W.

2007-01-01

Lack of virus specific antibody response is commonly observed in both HIV-1-infected humans and SIV-infected monkeys with rapid disease progression. However, the mechanisms underlying this important observation still remain unclear. In a titration study of a SIVmac239 viral stock, three out of six animals with viral inoculation rapidly progressed to AIDS within 5 months. Unexpectedly, there was no obvious depletion of CD4 + T cells in both peripheral and lymph node (LN) compartments in these animals. Instead, progressive depletion of proliferating B cells and disruption of the follicular dendritic cell (FDC) network in germinal centers (GC) was evident in the samples collected at as early as 20 days after viral challenge. This coincided with undetectable, or weak and transient, virus-specific antibody responses over the course of infection. In situ hybridization of SIV RNA in the LN samples revealed a high frequency of SIV productively infected cells and large amounts of accumulated viral RNA in the GCs in these animals. Early severe depletion of GC proliferating B cells and disruption of the FDC network may thus result in an inability to mount a virus-specific antibody response in rapid progressors, which has been shown to contribute to accelerated disease progression of SIV infection

Effect of adoptive transfer or depletion of regulatory T cells on triptolide-induced liver injury

Directory of Open Access Journals (Sweden)

Xinzhi eWang

2016-04-01

Full Text Available ObjectiveThe aim of this study is to clarify the role of regulatory T cell (Treg in triptolide (TP-induced hepatotoxicity. MethodsFemale C57BL/6 mice received either adoptive transfer of Tregs or depletion of Tregs, then underwent TP administration and were sacrificed 24 hours after TP administration. Liver injury was determined according to ALT and AST levels in serum and histopathological change in liver tissue. Hepatic frequencies of Treg cells and the mRNA expression levles of transcription factor FoxP3 and RORγt, IL-10, SOCS and Notch/Notch ligand were investigated.ResultsDuring TP-induced liver injury, hepatic Treg and IL-10 decreased, while Th17 cell transcription factor RORγt, SOCS signaling and Notch signaling increased, accompanied with liver inflammation. Adoptive transfer of Tregs ameliorated the severity of TP-induced liver injury, accompanied with increased levels of hepatic Treg and IL-10. Adoptive transfer of Tregs remarkably inhibited the expression of RORγt, SOCS3, Notch1 and Notch3. On the contrary, depletion of Treg cells in TP-administered mice resulted in a notable increase of RORγt, SOCS1, SOCS3 and Notch3, while the Treg and IL-10 of liver decreased. Consistent with the exacerbation of liver injury, higher serum levels of ALT and AST were detected in Treg-depleted mice. ConclusionsThese results showed that adoptive transfer or depletion of Tregs attenuated or aggravated TP-induced liver injury, suggesting that Tregs could play important roles in the progression of liver injury. SOCS proteins and Notch signaling affected Tregs, which may contribute to the pathogenesis of TP-induced hepatotoxicity.

Effects of cellular non-protein sulfhydryl depletion in radiation induced oncogenic transformation and genotoxicity in mouse C3H 10T1/2 cells

International Nuclear Information System (INIS)

Hei, T.K.; Geard, C.R.; Hall, E.J.

1984-01-01

A study was made of the effects of cellular non-protein sulfhydryl (NPSH) depletion on cytotoxicity, cell cycle kinetics, oncogenic transformation and sister chromatid exchange (SCE) in C 3 H 10T1/2 cells. Using DL-Buthionine S-R-Sulfoximine (BSO) to deplete thiols, it was found spectrophotometrically that less than 5% of control NPSH level remained in the cells after 24-hour treatment under aerated conditions. Such NPSH depleted cells, when subject to a 3 Gy γ-ray treatment, were found to have no radiosensitizing response either in terms of cell survival or oncogenic transformation. In addition, decreased levels of NPSH had no effect on spontaneous or radiation-induced SCE nor were cell cycle kinetics additionally altered. Therefore, the inability of NPSH depletion to alter γ-ray induced cellular transformation was unrelated to any possible effect of BSO on the cell cycle. These results suggest that such depletion may result in little or no additional oncogenic or genotoxic effects on aerated normal tissues

Human skin is protected by four functionally and phenotypically discrete populations of resident and recirculating memory T cells

Science.gov (United States)

Watanabe, Rei; Gehad, Ahmed; Yang, Chao; Campbell, Laura; Teague, Jessica E.; Schlapbach, Christoph; Elco, Christopher; Huang, Victor; Matos, Tiago R.; Kupper, Thomas S.; Clark, Rachael A.

2015-01-01

The skin of an adult human contains approximately 20 billion memory T cells. Epithelial barrier tissues are infiltrated by a combination of resident and recirculating T cells in mice but the relative proportions and functional activities of resident versus recirculating T cells have not been evaluated in human skin. We discriminated resident from recirculating T cells in human engrafted mice and lymphoma patients using alemtuzumab, a medication that depletes recirculating T cells from skin, and then analyzed these T cell populations in healthy human skin. All non-recirculating resident memory T cells (TRM) expressed CD69, but the majority were CD4+, CD103− and located in the dermis, in contrast to studies in mice. Both CD4+ and CD8+ CD103+ TRM were enriched in the epidermis, had potent effector functions and had a limited proliferative capacity compared to CD103− TRM. TRM of both types had more potent effector functions than recirculating T cells. Induction of CD103 on human T cells was enhanced by keratinocyte contact, depended on TGFβ and was independent of T cell keratinocyte adhesive interactions. We observed two distinct populations of recirculating T cells, CCR7+/L-selectin+ central memory T cells (TCM) and CCR7+/L-selectin− T cells, which we term migratory memory T cells (TMM). Circulating skin-tropic TMM were intermediate in cytokine production between TCM and effector memory T cells. In patients with cutaneous T cell lymphoma, malignant TCM and TMM induced distinct inflammatory skin lesions and TMM were depleted more slowly from skin after alemtuzumab, suggesting TMM may recirculate more slowly. In summary, human skin is protected by four functionally distinct populations of T cells, two resident and two recirculating, with differing territories of migration and distinct functional activities. PMID:25787765

Development of a fuel depletion sensitivity calculation module for multi-cell problems in a deterministic reactor physics code system CBZ

International Nuclear Information System (INIS)

Chiba, Go; Kawamoto, Yosuke; Narabayashi, Tadashi

2016-01-01

Highlights: • A new functionality of fuel depletion sensitivity calculations is developed in a code system CBZ. • This is based on the generalized perturbation theory for fuel depletion problems. • The theory with a multi-layer depletion step division scheme is described. • Numerical techniques employed in actual implementation are also provided. - Abstract: A new functionality of fuel depletion sensitivity calculations is developed as one module in a deterministic reactor physics code system CBZ. This is based on the generalized perturbation theory for fuel depletion problems. The theory for fuel depletion problems with a multi-layer depletion step division scheme is described in detail. Numerical techniques employed in actual implementation are also provided. Verification calculations are carried out for a 3 × 3 multi-cell problem consisting of two different types of fuel pins. It is shown that the sensitivities of nuclide number densities after fuel depletion with respect to the nuclear data calculated by the new module agree well with reference sensitivities calculated by direct numerical differentiation. To demonstrate the usefulness of the new module, fuel depletion sensitivities in different multi-cell arrangements are compared and non-negligible differences are observed. Nuclear data-induced uncertainties of nuclide number densities obtained with the calculated sensitivities are also compared.

Depletion of proton motive force by nisin in Listeria monocytogenes cells.

Science.gov (United States)

Bruno, M E; Kaiser, A; Montville, T J

1992-07-01

The basal proton motive force (PMF) levels and the influence of the bacteriocin nisin on the PMF were determined in Listeria monocytogenes Scott A. In the absence of nisin, the interconversion of the pH gradient (Z delta pH) and the membrane potential (delta psi) led to the maintenance of a fairly constant PMF at -160 mV over the external pH range 5.5 to 7.0. The addition of nisin at concentrations of greater than or equal to 5 micrograms/ml completely dissipated PMF in cells at external pH values of 5.5 and 7.0. With 1 microgram of nisin per ml, delta pH was completely dissipated but delta psi decreased only slightly. The action of nisin on PMF in L. monocytogenes Scott A was both time and concentration dependent. Valinomycin depleted only delta pH, whereas nigericin and carbonyl cyanide m-chlorophenylhydrazone depleted only delta psi, under conditions in which nisin depleted both. Four other L. monocytogenes strains had basal PMF parameters similar to those of strain Scott A. Nisin (2.5 micrograms/ml) also completely dissipated PMF in these strains.

Depleted uranium induces neoplastic transformation in human lung epithelial cells.

Science.gov (United States)

Xie, Hong; LaCerte, Carolyne; Thompson, W Douglas; Wise, John Pierce

2010-02-15

Depleted uranium (DU) is commonly used in military armor and munitions, and thus, exposure of soldiers and noncombatants is frequent and widespread. Previous studies have shown that DU has both chemical and radiological toxicity and that the primary route of exposure of DU to humans is through inhalation and ingestion. However, there is limited research information on the potential carcinogenicity of DU in human bronchial cells. Accordingly, we determined the neoplastic transforming ability of particulate DU to human bronchial epithelial cells (BEP2D). We observed the loss of contact inhibition and anchorage independent growth in cells exposed to DU after 24 h. We also characterized these DU-induced transformed cell lines and found that 40% of the cell lines exhibit alterations in plating efficiency and no significant changes in the cytotoxic response to DU. Cytogenetic analyses showed that 53% of the DU-transformed cell lines possess a hypodiploid phenotype. These data indicate that human bronchial cells are transformed by DU and exhibit significant chromosome instability consistent with a neoplastic phenotype.

Local partial depletion of CD11b+ cells and their influence on choroidal neovascularization using the CD11b-HSVTK mouse model.

Science.gov (United States)

Brockmann, Claudia; Kociok, Norbert; Dege, Sabrina; Davids, Anja-Maria; Brockmann, Tobias; Miller, Kelly R; Joussen, Antonia M

2018-03-14

To assess the influence of retinal macrophages and microglia on the formation of choroidal neovascularization (CNV). Therefore, we used a transgenic mouse (CD11b-HSVTK) in which the application of ganciclovir (GCV) results in a depletion of CD11b + cells. We first investigated if a local depletion of CD11b + macrophages and microglia in the retina is feasible. In a second step, the influence of CD11b + cell depletion on CNV formation was analysed. One eye of each CD11b-HSVTK mouse was injected with GCV, and the fellow eye received sodium chloride solution (NaCl). Cell counting was performed at day 3 and 7 (one injection) or at day 14 and 21 (two injections). Choroidal neovascularization (CNV) was induced by argon laser and analysed at day 14. The most effective CD11b + cell depletion was achieved 7 days after a single injection and 14 days after two injections of GCV. After two injections of GCV, we found a significant reduction of CD11b + cells in central (52 ± 23.9 cells/mm 2 ) and peripheral retina (53 ± 20.6 cells/mm 2 ); compared to eyes received NaCl (216 ± 49.0 and 210 ± 50.5 cells/mm 2 , p depletion of CD11b + cells in the retina. Nevertheless, only a partial depletion of CD11b + cells could be achieved compared to baseline data without any intravitreal injections. Our results did not reveal a significant reduction in CNV areas. In the light of previous knowledge, the potential influence of systemic immune cells on CNV formation might be more relevant than expected. © 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Targeted impairment of thymidine kinase 2 expression in cells induces mitochondrial DNA depletion and reveals molecular mechanisms of compensation of mitochondrial respiratory activity

International Nuclear Information System (INIS)

Villarroya, Joan; Lara, Mari-Carmen; Dorado, Beatriz; Garrido, Marta; Garcia-Arumi, Elena; Meseguer, Anna; Hirano, Michio; Vila, Maya R.

2011-01-01

Highlights: → We impaired TK2 expression in Ost TK1 - cells via siRNA-mediated interference (TK2 - ). → TK2 impairment caused severe mitochondrial DNA (mtDNA) depletion in quiescent cells. → Despite mtDNA depletion, TK2 - cells show high cytochrome oxidase activity. → Depletion of mtDNA occurs without imbalance in the mitochondrial dNTP pool. → Nuclear-encoded ENT1, DNA-pol γ, TFAM and TP gene expression is lowered in TK2 - cells. -- Abstract: The mitochondrial DNA (mtDNA) depletion syndrome comprises a clinically heterogeneous group of diseases characterized by reductions of the mtDNA abundance, without associated point mutations or rearrangements. We have developed the first in vitro model to study of mtDNA depletion due to reduced mitochondrial thymidine kinase 2 gene (TK2) expression in order to understand the molecular mechanisms involved in mtDNA depletion syndrome due to TK2 mutations. Small interfering RNA targeting TK2 mRNA was used to decrease TK2 expression in Ost TK1 - cells, a cell line devoid of endogenous thymidine kinase 1 (TK1). Stable TK2-deficient cell lines showed a reduction of TK2 levels close to 80%. In quiescent conditions, TK2-deficient cells showed severe mtDNA depletion, also close to 80% the control levels. However, TK2-deficient clones showed increased cytochrome c oxidase activity, higher cytochrome c oxidase subunit I transcript levels and higher subunit II protein expression respect to control cells. No alterations of the deoxynucleotide pools were found, whereas a reduction in the expression of genes involved in nucleoside/nucleotide homeostasis (human equilibrative nucleoside transporter 1, thymidine phosphorylase) and mtDNA maintenance (DNA-polymerase γ, mitochondrial transcription factor A) was observed. Our findings highlight the importance of cellular compensatory mechanisms that enhance the expression of respiratory components to ensure respiratory activity despite profound depletion in mtDNA levels.

Cell death by pyroptosis drives CD4 T-cell depletion in HIV-1 infection

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Doitsh, Gilad; Galloway, Nicole L. K.; Geng, Xin; Yang, Zhiyuan; Monroe, Kathryn M.; Zepeda, Orlando; Hunt, Peter W.; Hatano, Hiroyu; Sowinski, Stefanie; Muñoz-Arias, Isa; Greene, Warner C.

2014-01-01

The pathway causing CD4 T-cell death in HIV-infected hosts remains poorly understood although apoptosis has been proposed as a key mechanism. We now show that caspase-3-mediated apoptosis accounts for the death of only a small fraction of CD4 T cells corresponding to those that are both activated and productively infected. The remaining over 95% of quiescent lymphoid CD4 T cells die by caspase-1-mediated pyroptosis triggered by abortive viral infection. Pyroptosis corresponds to an intensely inflammatory form of programmed cell death in which cytoplasmic contents and pro-inflammatory cytokines, including IL-1β, are released. This death pathway thus links the two signature events in HIV infection--CD4 T-cell depletion and chronic inflammation--and creates a pathogenic vicious cycle in which dying CD4 T cells release inflammatory signals that attract more cells to die. This cycle can be broken by caspase 1 inhibitors shown to be safe in humans, raising the possibility of a new class of `anti-AIDS' therapeutics targeting the host rather than the virus.

Cytomegalovirus reactivation is associated with a lower rate of early relapse in myeloid malignancies independent of in-vivo T cell depletion strategy.

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Hilal, Talal; Slone, Stacey; Peterson, Shawn; Bodine, Charles; Gul, Zartash

2017-06-01

The association between cytomegalovirus (CMV) reactivation and relapse risk has not been evaluated in relation to T cell depletion strategies. We evaluated 93 patients who underwent allogeneic hematopoietic stem cell transplantation (HSCT) and analyzed the association between T cell depletion strategies with the cumulative incidence of relapse and CMV reactivation. A total of 33% of patients who received ATG vs. 34% who received alemtuzumab developed CMV reactivation. The cumulative incidence of relapse was 3% at 1year and 20% at 3 years in patients with CMV reactivation vs. 30% at 1year and 38% at 3 years in patients without CMV reactivation (p=0.02). When analyzed separately, this effect persisted in the myeloid, but not the lymphoid group. There was a numerical trend towards increased non-relapse mortality (NRM) in patients with CMV reactivation, especially in the myeloid group. The choice of T cell depleting agent and the rate of CMV reactivation were not associated with different overall survival (OS) rates. These results suggest that the choice of T cell depletion strategy may have similar effects on rates of CMV reactivation, disease relapse, and survival. Further studies examining these variables in patients not exposed to in-vivo T cell depleting agents may be of interest. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative analysis of in vivo T cell depletion with radiotherapy, combination chemotherapy, and the monoclonal antibody Campath-1G, using limiting dilution methodology

International Nuclear Information System (INIS)

Theobald, M.; Hoffmann, T.; Bunjes, D.; Heit, W.

1990-01-01

We have investigated the efficacy of standard conditioning regimens for bone marrow transplantation in depleting functional T lymphocytes in vivo and have compared it with the efficacy of the monoclonal antibody Campath-1G. Using limiting dilution techniques the frequencies of proliferating T cell precursors (PTL), cytotoxic T cell precursors (CTL-p), helper T cell precursors (HTL-p), and mature helper T cells (HTL) were determined before and after treatment. Both total body irradiation and combination chemotherapy with busulfan/cyclophosphamide were highly efficient at depleting PTL, CTL-p, and HTL-p (0-4 days) but spared HTL to a variable extent (0-99.5%). In the majority of patients treated with Campath-1G a similar degree of PTL, CTL-p, and HTL-p depletion was achieved, and, in addition, HTL were effectively removed (greater than 95.5%). These results suggest that Campath-1G could be successfully employed in depleting radio- and chemotherapy-resistant host T lymphocytes prior to T-depleted bone marrow transplantation

MG132, a proteasome inhibitor, induces human pulmonary fibroblast cell death via increasing ROS levels and GSH depletion.

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Park, Woo Hyun; Kim, Suhn Hee

2012-04-01

MG132 as a proteasome inhibitor can induce apoptotic cell death in lung cancer cells. However, little is known about the toxicological cellular effects of MG132 on normal primary lung cells. Here, we investigated the effects of N-acetyl cysteine (NAC) and vitamin C (well known antioxidants) or L-buthionine sulfoximine (BSO; an inhibitor of GSH synthesis) on MG132-treated human pulmonary fibroblast (HPF) cells in relation to cell death, reactive oxygen species (ROS) and glutathione (GSH). MG132 induced growth inhibition and death in HPF cells, accompanied by the loss of mitochondrial membrane potential (MMP; ∆ψm). MG132 increased ROS levels and GSH-depleted cell numbers in HPF cells. Both antioxidants, NAC and vitamin C, prevented growth inhibition, death and MMP (∆ψm) loss in MG132-treated HPF cells and also attenuated ROS levels in these cells. BSO showed a strong increase in ROS levels in MG132-treated HPF cells and slightly enhanced the growth inhibition, cell death, MMP (∆ψm) loss and GSH depletion. In addition, NAC decreased anonymous ubiquitinated protein levels in MG132-treated HPF cells. Furthermore, superoxide dismutase (SOD) 2, catalase (CTX) and GSH peroxidase (GPX) siRNAs enhanced HPF cell death by MG132, which was not correlated with ROS and GSH level changes. In conclusion, MG132 induced the growth inhibition and death of HPF cells, which were accompanied by increasing ROS levels and GSH depletion. Both NAC and vitamin C attenuated HPF cell death by MG132, whereas BSO slightly enhanced the death.

The effects of compound 48/80, morphine, and mast cell depletion on electroshock seizure in mice.

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Yillar, D O; Küçükhüseyin, C

2008-01-01

The effects of compound 48/80 (C48/80), morphine, and mast cell depletion on maximal electroshock seizure (MES) were studied in Swiss albino mice. An electrical current (60Hz, 0.2 msec) inducing convulsions in 50% of the animals (CC50) was assessed as 46 mA. Compound 48/80 (5 mg/kg) and morphine (100mg/kg) were administered subcutaneously. CC50 was applied separately to electroshock-unexposed animal groups at 15, 30, 60, 120, and 240 min after the onset of the experiment. In untreated controls, the percent of seizure induced by CC50 and percent of death among mice having convulsions were 50 and 20, respectively. After C48/80, a significant increase in rates of seizure at 60th and 120th min and death beyond 60th min (p seizure tended to decrease following mast-cell depletion, which was readily reversed by C48/80 at the 60th min (p seizure induced by the application of CC50 in the mast-cell depleted animals (anticonvulsive action) but increased the percent of dying animals by as much as 100% at the 30th and 60th min (p opiate receptors in the brain.

Depletion and repopulation of lymphocytes in Peyer's patches of mice after total lymphoid irradiation

International Nuclear Information System (INIS)

Ermak, T.H.; Steger, H.J.; Owen, R.L.; Strober, S.

1988-01-01

The depletion and repopulation of lymphocytes in specific cellular domains of mouse Peyer's patches were examined following total lymphoid irradiation (TLI). BALB/c mice 5-months-old were given 17 fractionated doses of irradiation to a total of 3400 to 4250 rads over a 4-week period, and Peyer's patches were examined by immunohistochemistry at 1 to 4 days and 1 to 4 weeks after TLI. Cryostat sections were labeled with monoclonal antibodies directed against B220 (B cells), Thy-1.2 (all T cells), L3T4 (helper T cells), and Ly-2 (cytotoxic/suppressor T cells). In depleted mice, Peyer's patches were greatly reduced in size in comparison to controls, although the structural framework of follicles, domes, and interfollicular areas was still present. B cells in follicles were reduced to a small core of B220+ cells interspersed with nonlymphocytic cells. T cells were virtually eliminated from the patch except for a small population of Thy-1.2+ cells that were neither L3T4+ nor Ly-2+ in follicle domes. During early stages of repopulation at 1 to 2 weeks after TLI, follicles increased in size and were populated by helper T cells but Peyer's patches lacked discrete interfollicular T cell regions. At 3 to 4 weeks after TLI, T cell regions were found in interfollicular areas. The results indicate that morphologically distinct cellular domains are maintained in Peyer's patches after TLI which are sequentially repopulated by immigrating lymphocytes

Potential involvement of oxygen intermediates and glutathione depletion in UV-induced epidermal cell injury in vitro

International Nuclear Information System (INIS)

Hsieh, G.C.; Acosta, D.

1991-01-01

Generation of reactive oxygen species (ROS) and depletion of glutathione (GSH) are suggested as the cytotoxic mechanisms for UVB-induced cellular damage. Primary monolayer cultures of epidermal keratinocytes (KCs) prepared from the skin of neonatal rats were irradiated with UVB at levels of 0.25-3.0 J/cm 2 . Cytotoxicity was measured at 3, 6, and 12 hr after UVB radiation. Exposure of KCs to UVB resulted in time- and dose-related toxic responses as determined by plasma membrane integrity, lysosomal function and mitochondrial metabolic activity. Irradiated KCs generated superoxide in a dose-dependent manner when compared to sham-irradiated cells. Superoxide formation, which occurred before and concomitant with cell injury, was decreased by superoxide dismutase (SOD). Cell injury was also significantly prevented by ROS scavengers, SOD and catalase. Pretreatment of cells with endocytosis inhibitors, cytochalasin B and methylamine, suppressed the ability of SOD and catalase to protect keratinocytes from UVB-induced toxicity. Irradiation of cells with UVB caused rapid depletion of GSH to about 30% of unirradiated levels within 15 min. UVB-irradiation led to a rapid transient increase in GSH peroxidase activity, concomitant with a marked decrease in the GSH/GSSG ratio. After 1 hr., while the GSH/GSSG ratio remained low, the GSH peroxidase activity declined below the control levels in UVB-treated epidermal cells. Following extensive GSH depletion in cells preincubated with 0.1 mM buthiomine sulfoximine, KCs became strongly sensitized to the cytotoxic action of UVB. These results indicate that UVB-induced cell injury in cultured KCs may be mediated by ROs and that endogenous GSH may play an important protective role against the cytotoxic action of UVB

Preferential infection and depletion of Mycobacterium tuberculosis-specific CD4 T cells after HIV-1 infection

NARCIS (Netherlands)

Geldmacher, Christof; Ngwenyama, Njabulo; Schuetz, Alexandra; Petrovas, Constantinos; Reither, Klaus; Heeregrave, Edwin J.; Casazza, Joseph P.; Ambrozak, David R.; Louder, Mark; Ampofo, William; Pollakis, Georgios; Hill, Brenna; Sanga, Erica; Saathoff, Elmar; Maboko, Leonard; Roederer, Mario; Paxton, William A.; Hoelscher, Michael; Koup, Richard A.

2010-01-01

HIV-1 infection results in the progressive loss of CD4 T cells. In this study, we address how different pathogen-specific CD4 T cells are affected by HIV infection and the cellular parameters involved. We found striking differences in the depletion rates between CD4 T cells to two common

Tracking the stochastic fate of cells of the renin lineage after podocyte depletion using multicolor reporters and intravital imaging.

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Natalya V Kaverina

Full Text Available Podocyte depletion plays a major role in focal segmental glomerular sclerosis (FSGS. Because cells of the renin lineage (CoRL serve as adult podocyte and parietal epithelial cell (PEC progenitor candidates, we generated Ren1cCre/R26R-ConfettiTG/WT and Ren1dCre/R26R-ConfettiTG/WT mice to determine CoRL clonality during podocyte replacement. Four CoRL reporters (GFP, YFP, RFP, CFP were restricted to cells in the juxtaglomerular compartment (JGC at baseline. Following abrupt podocyte depletion in experimental FSGS, all four CoRL reporters were detected in a subset of glomeruli at day 28, where they co-expressed de novo four podocyte proteins (podocin, nephrin, WT-1 and p57 and two glomerular parietal epithelial cell (PEC proteins (claudin-1, PAX8. To monitor the precise migration of a subset of CoRL over a 2w period following podocyte depletion, intravital multiphoton microscopy was used. Our findings demonstrate direct visual support for the migration of single CoRL from the JGC to the parietal Bowman's capsule, early proximal tubule, mesangium and glomerular tuft. In summary, these results suggest that following podocyte depletion, multi-clonal CoRL migrate to the glomerulus and replace podocyte and PECs in experimental FSGS.

Comparison of radiation-induced DNA-protein cross-links formed in oxic, hypoxic, and glutathione depleted cells

International Nuclear Information System (INIS)

Xue, L.; Friedman, L.R.; Chiu, S.; Ramakrishnan, N.; Oleinick, N.L.

1987-01-01

Treatment of cells with L-buthionine sulfoximine (BSO) inhibits the synthesis of glutathione (GSH). Subsequent metabolism depletes the cells of GSH. GSH-depletion sensitizes both oxic and hypoxic cells to the lethal effects of ionizing radiation. DNA-protein cross-links (DPC) are formed preferentially between DNA sequences active in transcription and a subset of proteins of the nuclear matrix. Thus, DPC may be an indicator lesion of damage in sensitive regions of the genome. The interrelationships between GSH level, oxic vs. hypoxic status, and the yield of DPC have been studied in terms of number of lesions and repair rate in Chinese hamster V79 and in human lung carcinoma A549 cells. The data suggest that elevated background levels of DPC are indicative of a reduced repair capacity, and greater radiation-induced yields of DPC in hypoxia may also be indicative of a compromised repair mechanism

Partial regulatory T cell depletion prior to acute feline immunodeficiency virus infection does not alter disease pathogenesis.

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S Rochelle Mikkelsen

2011-02-01

Full Text Available Feline immunodeficiency virus (FIV infection in cats follows a disease course similar to HIV-1, including a short acute phase characterized by high viremia, and a prolonged asymptomatic phase characterized by low viremia and generalized immune dysfunction. CD4(+CD25(hiFoxP3(+ immunosuppressive regulatory T (Treg cells have been implicated as a possible cause of immune dysfunction during FIV and HIV-1 infection, as they are capable of modulating virus-specific and inflammatory immune responses. Additionally, the immunosuppressive capacity of feline Treg cells has been shown to be increased during FIV infection. We have previously shown that transient in vivo Treg cell depletion during asymptomatic FIV infection reveals FIV-specific immune responses suppressed by Treg cells. In this study, we sought to determine the immunological influence of Treg cells during acute FIV infection. We asked whether Treg cell depletion prior to infection with the highly pathogenic molecular clone FIV-C36 in cats could alter FIV pathogenesis. We report here that partial Treg cell depletion prior to FIV infection does not significantly change provirus, viremia, or CD4(+ T cell levels in blood and lymphoid tissues during the acute phase of disease. The effects of anti-CD25 mAb treatment are truncated in cats acutely infected with FIV-C36 as compared to chronically infected cats or FIV-naïve cats, as Treg cell levels were heightened in all treatment groups included in the study within two weeks post-FIV infection. Our findings suggest that the influence of Treg cell suppression during FIV pathogenesis is most prominent after Treg cells are activated in the environment of established FIV infection.

Partial regulatory T cell depletion prior to acute feline immunodeficiency virus infection does not alter disease pathogenesis.

Science.gov (United States)

Mikkelsen, S Rochelle; Long, Julie M; Zhang, Lin; Galemore, Erin R; VandeWoude, Sue; Dean, Gregg A

2011-02-25

Feline immunodeficiency virus (FIV) infection in cats follows a disease course similar to HIV-1, including a short acute phase characterized by high viremia, and a prolonged asymptomatic phase characterized by low viremia and generalized immune dysfunction. CD4(+)CD25(hi)FoxP3(+) immunosuppressive regulatory T (Treg) cells have been implicated as a possible cause of immune dysfunction during FIV and HIV-1 infection, as they are capable of modulating virus-specific and inflammatory immune responses. Additionally, the immunosuppressive capacity of feline Treg cells has been shown to be increased during FIV infection. We have previously shown that transient in vivo Treg cell depletion during asymptomatic FIV infection reveals FIV-specific immune responses suppressed by Treg cells. In this study, we sought to determine the immunological influence of Treg cells during acute FIV infection. We asked whether Treg cell depletion prior to infection with the highly pathogenic molecular clone FIV-C36 in cats could alter FIV pathogenesis. We report here that partial Treg cell depletion prior to FIV infection does not significantly change provirus, viremia, or CD4(+) T cell levels in blood and lymphoid tissues during the acute phase of disease. The effects of anti-CD25 mAb treatment are truncated in cats acutely infected with FIV-C36 as compared to chronically infected cats or FIV-naïve cats, as Treg cell levels were heightened in all treatment groups included in the study within two weeks post-FIV infection. Our findings suggest that the influence of Treg cell suppression during FIV pathogenesis is most prominent after Treg cells are activated in the environment of established FIV infection.

Vitamin C Depletion and All-Cause Mortality in Renal Transplant Recipients.

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Sotomayor, Camilo G; Eisenga, Michele F; Gomes Neto, Antonio W; Ozyilmaz, Akin; Gans, Rijk O B; Jong, Wilhelmina H A de; Zelle, Dorien M; Berger, Stefan P; Gaillard, Carlo A J M; Navis, Gerjan J; Bakker, Stephan J L

2017-06-02

Vitamin C may reduce inflammation and is inversely associated with mortality in the general population. We investigated the association of plasma vitamin C with all-cause mortality in renal transplant recipients (RTR); and whether this association would be mediated by inflammatory biomarkers. Vitamin C, high sensitive C-reactive protein (hs-CRP), soluble intercellular cell adhesion molecule 1 (sICAM-1), and soluble vascular cell adhesion molecule 1 (sVCAM-1) were measured in a cohort of 598 RTR. Cox regression analyses were used to analyze the association between vitamin C depletion (≤28 µmol/L; 22% of RTR) and mortality. Mediation analyses were performed according to Preacher and Hayes's procedure. At a median follow-up of 7.0 (6.2-7.5) years, 131 (21%) patients died. Vitamin C depletion was univariately associated with almost two-fold higher risk of mortality (Hazard ratio (HR) 1.95; 95% confidence interval (95%CI) 1.35-2.81, p C depletion is frequent and independently associated with almost two-fold higher risk of mortality in RTR. It may be hypothesized that the beneficial effect of vitamin C at least partly occurs through decreasing inflammation.

Depletion of resident macrophages does not alter sensory regeneration in the avian cochlea.

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Mark E Warchol

Full Text Available Macrophages are the primary effector cells of the innate immune system and are also activated in response to tissue injury. The avian cochlea contains a population of resident macrophages, but the precise function of those cells is not known. The present study characterized the behavior of cochlear macrophages after aminoglycoside ototoxicity and also examined the possible role of macrophages in sensory regeneration. We found that the undamaged chick cochlea contains a large resting population of macrophages that reside in the hyaline cell region, immediately outside the abneural (inferior border of the sensory epithelium. Following ototoxic injury, macrophages appear to migrate out of the hyaline cell region and towards the basilar membrane, congregating immediately below the lesioned sensory epithelium. In order to determine whether recruited macrophages contribute to the regeneration of sensory receptors, we quantified supporting cell proliferation and hair cell recovery after the elimination of most resident macrophages via application of liposomally-encapsulated clodronate. Examination of macrophage-depleted specimens at two days following ototoxic injury revealed no deficits in hair cell clearance, when compared to normal controls. In addition, we found that elimination of macrophages did not affect either regenerative proliferation of supporting cells or the production of replacement hair cells. However, we did find that macrophage-depleted cochleae contained reduced numbers of proliferative mesothelial cells below the basilar membrane. Our data suggest that macrophages are not required for normal debris clearance and regeneration, but that they may play a role in the maintenance of the basilar membrane.

MAPK inhibitors, particularly the JNK inhibitor, increase cell death effects in H2O2-treated lung cancer cells via increased superoxide anion and glutathione depletion.

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Park, Woo Hyun

2018-02-01

Reactive oxygen species (ROS), especially hydrogen peroxide (H2O2), induce apoptosis in cancer cells by regulating mitogen-activated protein kinase (MAPK) signaling pathways. The present study investigated the effects of MAPK inhibitors on cell growth and death as well as changes in ROS and glutathione (GSH) levels in H2O2-treated Calu-6 and A549 lung cancer cells. H2O2 inhibited growth and induced death of Calu-6 and A549 lung cancer cells. All MAPK inhibitors appeared to enhance growth inhibition in H2O2-treated Calu-6 and A549 lung cancer cells and increased the percentage of Annexin V-FITC-positive cells in these cancer cells. Among the MAPK inhibitors, a JNK inhibitor significantly augmented the loss of mitochondrial membrane potential (MMP; ΔΨm) in H2O2-treated Calu-6 and A549 lung cancer cells. Intracellular ROS levels were significantly increased in the H2O2-treated cells at 1 and 24 h. Only the JNK inhibitor increased ROS levels in the H2O2-treated cells at 1 h and all MAPK inhibitors raised superoxide anion levels in these cells at 24 h. In addition, H2O2 induced GSH depletion in Calu-6 and A549 cells and the JNK inhibitor significantly enhanced GSH depletion in H2O2‑treated cells. Each of the MAPK inhibitors altered ROS and GSH levels differently in the Calu-6 and A549 control cells. In conclusion, H2O2 induced growth inhibition and death in lung cancer cells through oxidative stress and depletion of GSH. The enhanced effect of MAPK inhibitors, especially the JNK inhibitor, on cell death in H2O2-treated lung cancer cells was correlated with increased O2•- levels and GSH depletion.

RNAi mediated acute depletion of Retinoblastoma protein (pRb promotes aneuploidy in human primary cells via micronuclei formation

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Iovino Flora

2009-11-01

Full Text Available Abstract Background Changes in chromosome number or structure as well as supernumerary centrosomes and multipolar mitoses are commonly observed in human tumors. Thus, centrosome amplification and mitotic checkpoint dysfunctions are believed possible causes of chromosomal instability. The Retinoblastoma tumor suppressor (RB participates in the regulation of synchrony between DNA synthesis and centrosome duplication and it is involved in transcription regulation of some mitotic genes. Primary human fibroblasts were transfected transiently with short interfering RNA (siRNA specific for human pRb to investigate the effects of pRb acute loss on chromosomal stability. Results Acutely pRb-depleted fibroblasts showed altered expression of genes necessary for cell cycle progression, centrosome homeostasis, kinetochore and mitotic checkpoint proteins. Despite altered expression of genes involved in the Spindle Assembly Checkpoint (SAC the checkpoint seemed to function properly in pRb-depleted fibroblasts. In particular AURORA-A and PLK1 overexpression suggested that these two genes might have a role in the observed genomic instability. However, when they were post-transcriptionally silenced in pRb-depleted fibroblasts we did not observe reduction in the number of aneuploid cells. This finding suggests that overexpression of these two genes did not contribute to genomic instability triggered by RB acute loss although it affected cell proliferation. Acutely pRb-depleted human fibroblasts showed the presence of micronuclei containing whole chromosomes besides the presence of supernumerary centrosomes and aneuploidy. Conclusion Here we show for the first time that RB acute loss triggers centrosome amplification and aneuploidy in human primary fibroblasts. Altogether, our results suggest that pRb-depleted primary human fibroblasts possess an intact spindle checkpoint and that micronuclei, likely caused by mis-attached kinetochores that in turn trigger

Juvenile spermatogonial depletion (jsd): a genetic defect of germ cell proliferation of male mice.

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Beamer, W G; Cunliffe-Beamer, T L; Shultz, K L; Langley, S H; Roderick, T H

1988-05-01

Adult C57BL/6J male mice homozygous for the mutant gene, juvenile spermatogonial depletion (jsd/jsd), show azoosper4ia and testes reduced to one-third normal size, but are otherwise phenotypically normal. In contrast, adult jsd/jsd females are fully fertile. This feature facilitated mapping the jsd gene to the centromeric end of chromosome 1; the gene order is jsd-Isocitrate dehydrogenase-1 (Idh-1)-Peptidase-3 (Pep-3). Analysis of testicular histology from jsd/jsd mice aged 3-10 wk revealed that these mutant mice experience one wave of spermatogenesis, but fail to continue mitotic proliferation of type A spermatogonial cells at the basement membrane. As a consequence, histological sections of testes from mutant mice aged 8-52 wk showed tubules populated by modest numbers of Sertoli cells, with only an occasional spermatogonial cell. Some sperm with normal morphology and motility were observed in epididymides of 6.5- but not in 8-wk or older mutants. Treatment with retinol failed to alter the loss of spermatogenesis in jsd/jsd mice. Analyses of serum hormones of jsd/jsd males showed that testosterone levels were normal at all ages--a finding corroborated by normal seminal vesicle and vas deferens weights, whereas serum follicle-stimulating hormone levels were significantly elevated in mutant mice from 4 to 20 wk of age. We hypothesize the jsd/jsd male may be deficient in proliferative signals from Sertoli cells that are needed for spermatogenesis.

The effect of intra- and extracellular GSH depletion on aerobic radiosensitization in three cell lines

International Nuclear Information System (INIS)

Clark, E.P.; Epp, E.R.; Morse-Gaudio, M.; Biaglow, J.E.

1985-01-01

The effect of changes in the intra- and extracellular glutathione (GSH) concentrations on aerobic radiosensitization was studied in thee cell lines: CHO, V79 and A549. Intracellular GSH was metabolically depleted after the inhibition of GSH synthesis by buthionine sulfoximine (BSO) treatment of attached cell cultures. Extracellular GSH was controlled through the replacement of growth medium with a thiol-free salt solution and, where desired, by the exogenous addition of GSH. Each of the cell lines examined exhibited an enhanced aerobic radioresponse when the intracellular GSH was extensively depleted (GSH < 5% of control after 1.0 mM BSO/24 hr treatment) and the extracellular GSH concentration was zero. However, this enhanced radiosensitivity was eliminated by the addition of exogenous GSH, albeit at a high concentration (5 mM). Most interesting and as yet unexplained is the observation that GSH appears to affect restoration of the control radioresponse without increasing the intracellular GSH concentration

A comparison of cell proliferation in normal and neoplastic intestinal epithelia following either biogenic amine depletion or monoamine oxidase inhibition.

Science.gov (United States)

Tutton, P J; Barkla, D H

1976-08-11

Epithelial cell proliferation was studied in the jejunum and in the colon of normal rats, in the colon of dimethylhydrazine-treated rats and in dimethylhydrazine-induced adenocarcinoma of the colon using a stathmokinetic technique. Estimates of cell proliferation rates in these four tissues were then repeated in animals which had been depleted of biogenic animes by treatment with reserpine and in animals whose monoamine oxidase was inhibited by treatment with nialamide. In amine-depleted animals cell proliferation essentially ceased in all four tissues examined. Inhibition of monoamine oxidase did not significantly influence cell proliferation in nonmalignant tissues but accelerated cell division in colonic tumours.

SCD1 inhibition causes cancer cell death by depleting mono-unsaturated fatty acids.

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Paul Mason

Full Text Available Increased metabolism is a requirement for tumor cell proliferation. To understand the dependence of tumor cells on fatty acid metabolism, we evaluated various nodes of the fatty acid synthesis pathway. Using RNAi we have demonstrated that depletion of fatty-acid synthesis pathway enzymes SCD1, FASN, or ACC1 in HCT116 colon cancer cells results in cytotoxicity that is reversible by addition of exogenous fatty acids. This conditional phenotype is most pronounced when SCD1 is depleted. We used this fatty-acid rescue strategy to characterize several small-molecule inhibitors of fatty acid synthesis, including identification of TOFA as a potent SCD1 inhibitor, representing a previously undescribed activity for this compound. Reference FASN and ACC inhibitors show cytotoxicity that is less pronounced than that of TOFA, and fatty-acid rescue profiles consistent with their proposed enzyme targets. Two reference SCD1 inhibitors show low-nanomolar cytotoxicity that is offset by at least two orders of magnitude by exogenous oleate. One of these inhibitors slows growth of HCT116 xenograft tumors. Our data outline an effective strategy for interrogation of on-mechanism potency and pathway-node-specificity of fatty acid synthesis inhibitors, establish an unambiguous link between fatty acid synthesis and cancer cell survival, and point toward SCD1 as a key target in this pathway.

SCD1 inhibition causes cancer cell death by depleting mono-unsaturated fatty acids.

Science.gov (United States)

Mason, Paul; Liang, Beirong; Li, Lingyun; Fremgen, Trisha; Murphy, Erin; Quinn, Angela; Madden, Stephen L; Biemann, Hans-Peter; Wang, Bing; Cohen, Aharon; Komarnitsky, Svetlana; Jancsics, Kate; Hirth, Brad; Cooper, Christopher G F; Lee, Edward; Wilson, Sean; Krumbholz, Roy; Schmid, Steven; Xiang, Yibin; Booker, Michael; Lillie, James; Carter, Kara

2012-01-01

Increased metabolism is a requirement for tumor cell proliferation. To understand the dependence of tumor cells on fatty acid metabolism, we evaluated various nodes of the fatty acid synthesis pathway. Using RNAi we have demonstrated that depletion of fatty-acid synthesis pathway enzymes SCD1, FASN, or ACC1 in HCT116 colon cancer cells results in cytotoxicity that is reversible by addition of exogenous fatty acids. This conditional phenotype is most pronounced when SCD1 is depleted. We used this fatty-acid rescue strategy to characterize several small-molecule inhibitors of fatty acid synthesis, including identification of TOFA as a potent SCD1 inhibitor, representing a previously undescribed activity for this compound. Reference FASN and ACC inhibitors show cytotoxicity that is less pronounced than that of TOFA, and fatty-acid rescue profiles consistent with their proposed enzyme targets. Two reference SCD1 inhibitors show low-nanomolar cytotoxicity that is offset by at least two orders of magnitude by exogenous oleate. One of these inhibitors slows growth of HCT116 xenograft tumors. Our data outline an effective strategy for interrogation of on-mechanism potency and pathway-node-specificity of fatty acid synthesis inhibitors, establish an unambiguous link between fatty acid synthesis and cancer cell survival, and point toward SCD1 as a key target in this pathway.

Effect of glutathione depletion on the aerobic radiation response of A549 human lung carcinoma cells

International Nuclear Information System (INIS)

Biaglow, J.E.; Clark, E.P.; Varnes, M.E.; Tuttle, S.W.; Epp, E.R.

1985-01-01

The authors demonstrated that depletion of glutathione (GSH) from cultured A549 cells to non-detectable levels, using L-buthionine sulfoximine (L-BSO), results in an increased aerobic radiation response. This response can be further increased if dimethylfumarate (DMF) is added concurrently with L-BSO. L-BSO is a relatively slow depletor of GSH compared to DMF, which acts by both spontaneous and enzyme catalysed reactions. The authors have studied: 1. the effect of continuous long-term exposure to 0.1 mM L-BSO on GSH levels and the subsequent radiation response and 2. the effect of GSH depletion on enzymes essential for radical detoxification. The results show an enhanced aerobic radiation response that increases with the time of exposure to L-BSO. For example surviving fraction (S.F.) after 5 Gy for cells exposed to L-BSO for 24 hrs is 0.004 and 0.08 for control cultures. Cells washed free of medium and irradiated in Hanks' show 0.0007 S.F. after 120 hr exposure to L-BSO and S.F. of 0.075 for the control cultures. The relationship between the chronic GSH depleted state, GSH peroxidase, and radiation induced lipid peroxidation is being investigated

Relapse of nephrotic syndrome during post-rituximab peripheral blood B-lymphocyte depletion.

Science.gov (United States)

Sato, Mai; Kamei, Koichi; Ogura, Masao; Ishikura, Kenji; Ito, Shuichi

2018-02-01

Rituximab is effective against complicated childhood steroid-dependent nephrotic syndrome (SDNS). Peripheral blood B-lymphocyte (B-cell) depletion is strongly correlated with persistent remission, relapse rarely occurring during B-cell depletion; however, we have encountered several such patients. We retrospectively analyzed the characteristics and clinical course of 82 patients with SDNS treated with rituximab from January 2007 to December 2012 in our institution. Six of 82 patients (7.3%) had relapses during B-cell depletion after receiving rituximab (relapsed group). The remaining 76 patients did not have relapses during B-cell depletion (non-relapsed group). The median time to initial relapse during B-cell depletion was 85 days after receiving rituximab, which is significantly shorter than in the non-relapsed group (410 days, p = 0.0003). The median annual numbers of relapses after receiving rituximab were 2.5 and 0.9 in the relapsed and non-relapsed groups, respectively (p depletion did not differ between the two groups. Relapse during B-cell depletion after receiving rituximab suggests that various pathophysiological mechanisms play a part in childhood nephrotic syndrome.

Rituximab administration within 6 months of T cell-depleted allogeneic SCT is associated with prolonged life-threatening cytopenias.

Science.gov (United States)

McIver, Zachariah; Stephens, Nicole; Grim, Andrew; Barrett, A John

2010-11-01

The monoclonal anti-CD20 antibody Rituximab (RTX) is increasingly used in allogeneic stem cell transplantation (SCT) to treat lymphoproliferative disorders and chronic graft-versus-host disease (GVHD). RTX administration can be complicated by delayed and prolonged neutropenia, but the mechanism is unclear. We report the occurrence of profound cytopenias following RTX given in the conditioning regimen or early after T cell-deplete SCT to treat B cell lymphoproliferative disorders or chronic GVHD (cGVHD). Between 2006 and 2009, 102 patients (median age: 43 years, range: 13-68 years), received a myeloablative matched-sibling T cell-deplete SCT for lymphoid or myeloid hematologic disorders. Neutropenia occurring within 4 weeks of treatment developed in 16 of 17 patients given RTX within the first 190 days after SCT. Fourteen patients developed severe neutropenia (count SCT compared to patients with cGVHD not treated with early RTX (P SCT experienced only moderate neutropenia 3 to 5 months after treatment lasting 10 to 20 days while maintaining absolute neutrophil count (ANC) >1.0 × 10⁹/L. Although RTX rapidly controlled cGVHD, we conclude that its administration early after T cell-deplete SCT is associated with prolonged profound and life-threatening cytopenias, and should be avoided. Published by Elsevier Inc.

Intraocular Injection of ES Cell-Derived Neural Progenitors Improve Visual Function in Retinal Ganglion Cell-Depleted Mouse Models

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Mundackal S. Divya

2017-09-01

Full Text Available Retinal ganglion cell (RGC transplantation is a promising strategy to restore visual function resulting from irreversible RGC degeneration occurring in glaucoma or inherited optic neuropathies. We previously demonstrated FGF2 induced differentiation of mouse embryonic stem cells (ESC to RGC lineage, capable of retinal ganglion cell layer (GCL integration upon transplantation. Here, we evaluated possible improvement of visual function by transplantation of ES cell derived neural progenitors in RGC depleted glaucoma mice models. ESC derived neural progenitors (ES-NP were transplanted into N-Methyl-D-Aspartate (NMDA injected, RGC-ablated mouse models and a pre-clinical glaucoma mouse model (DBA/2J having sustained higher intra ocular pressure (IOP. Visual acuity and functional integration was evaluated by behavioral experiments and immunohistochemistry, respectively. GFP-expressing ES-NPs transplanted in NMDA-injected RGC-depleted mice differentiated into RGC lineage and possibly integrating into GCL. An improvement in visual acuity was observed after 2 months of transplantation, when compared to the pre-transplantation values. Expression of c-Fos in the transplanted cells, upon light induction, further suggests functional integration into the host retinal circuitry. However, the transplanted cells did not send axonal projections into optic nerve. Transplantation experiments in DBA/2J mouse showed no significant improvement in visual functions, possibly due to both host and transplanted retinal cell death which could be due to an inherent high IOP. We showed that, ES NPs transplanted into the retina of RGC-ablated mouse models could survive, differentiate to RGC lineage, and possibly integrate into GCL to improve visual function. However, for the survival of transplanted cells in glaucoma, strategies to control the IOP are warranted.

Clonal evolution following chemotherapy-induced stem cell depletion in cats heterozygous for glucose-6-phosphate dehydrogenase

International Nuclear Information System (INIS)

Abkowitz, J.L.; Ott, R.M.; Holly, R.D.; Adamson, J.W.

1988-01-01

The number of hematopoietic stem cells necessary to support normal hematopoiesis is not known but may be small. If so, the depletion or damage of such cells could result in apparent clonal dominance. To test this hypothesis, dimethylbusulfan [2 to 4 mg/kg intravenously (IV) x 3] was given to cats heterozygous for the X-linked enzyme glucose-6-phosphate dehydrogenase (G-6-PD). These cats were the daughters of domestic X Geoffroy parents. After the initial drug-induced cytopenias (2 to 4 weeks), peripheral blood counts and the numbers of marrow progenitors detected in culture remained normal, although the percentages of erythroid burst-forming cells (BFU-E) and granulocyte/macrophage colony-forming cells (CFU-GM) in DNA synthesis increased, as determined by the tritiated thymidine suicide technique. In three of six cats treated, a dominance of Geoffroy-type G-6-PD emerged among the progenitor cells, granulocytes, and RBCs. These skewed ratios of domestic to Geoffroy-type G-6-PD have persisted greater than 3 years. No changes in cell cycle kinetics or G-6-PD phenotypes were noted in similar studies in six control cats. These data suggest that clonal evolution may reflect the depletion or damage of normal stem cells and not only the preferential growth and dominance of neoplastic cells

Temporary CD8(+) T-cell depletion in pigs does not exacerbate infection with porcine reproductive and respiratory syndrome virus (PRRSV)

DEFF Research Database (Denmark)

Lohse, Louise; Nielsen, Jens; Eriksen, Lis

2004-01-01

Several studies have demonstrated a consistent increase in the CD8(+) T-cell subset of pigs following infection with porcine reproductive and respiratory virus (PRRSV). Consequently, it has been suggested that CD8(+) T-cells may play an important role in protection against this infection. In order...... increased disease nor influenced the ability to clear virus in the treated pigs......., confirmed the depletion effect of specific mAb therapy. Almost complete depletion of cell subsets expressing the CD8(+) antigen was obtained on day 2 and 5 post infection (PI) with nadir less than 1 % of peripheral blood mononuclear cells (PBMC). One week PI, an increase in T-cell subsets was observed...

Effect of intratracheally instilled depleted uranium on immunological function of rats

International Nuclear Information System (INIS)

You Hanhu; Yang Zhihua; Cao Zhenshan; Zhu Maoxiang; Liu Xingrong

2004-01-01

Objective: To study immunological effects of depleted uranium in rats. Methods: Wistar rats were exposed to depleted uranium by single intratracheal instillation. Body weight and peripheral blood cells were measured weekly and immunological functions were evaluated by weight coefficient of immune organs, plague forming cells of splenocytes, total and subpopulation counts of lymphocytes in thymus. Results: Early after administration, body weight decreased and red blood cells as well as platelets reduced while white blood cells increased, which returned to normal within 1 or 2 months. Immunological functions of splenocytes and thymocytes were affected dose-dependently by depleted uranium. Conclusion: Depleted uranium induces immunological dysfunction in rats. (authors)

Haematological malignancies in childhood in Croatia: Investigating the theories of depleted uranium, chemical plant damage and 'population mixing'

International Nuclear Information System (INIS)

Labar, B.; Rudan, I.; Ivankovic, D.; Biloglav, Z.; Mrsic, M.; Strnad, M.; Fucic, A.; Znaor, A.; Bradic, T.; Campbell, H.

2004-01-01

Some of potential causes proposed to explain the reported increase of haematological malignancies in childhood during or after the war period in several countries include depleted uranium, chemical pollution and population mixing theory. The aim of this study was to define the population of Croatian children aged 0-14 years who were potentially exposed to each of those risks during the war and to investigate any possible association between the exposure and the incidence of haematological malignancies. The authors analyzed the data reported by the Cancer Registry of Croatia during the pre-war period (1986-1990), war period (1991-1995) and post-war period (1996-1999). In the group of 10 counties potentially exposed to depleted uranium and two counties where chemical war damage occurred, no significant difference in incidence of the studied haematological malignancies was noted in comparison to pre-war period. The incidence of lymphatic leukaemia significantly increased in four counties where population mixing had occurred during the war period, supporting the 'mixing theory'. In those counties, the incidence of Hodgkin's lymphoma decreased during and after the war. In Croatia as a whole, decreases in incidence of myeloid leukaemias during war and non-Hodgkin lymphoma after the war were noted

CFTR depletion results in changes in fatty acid composition and promotes lipogenesis in intestinal Caco 2/15 cells.

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Geneviève Mailhot

2010-05-01

Full Text Available Abnormal fatty acid composition (FA in plasma and tissue lipids frequently occurs in homozygous and even in heterozygous carriers of cystic fibrosis transmembrane conductance regulator (CFTR mutations. The mechanism(s underlying these abnormalities remained, however, poorly understood despite the potentially CFTR contributing role.The aim of the present study was to investigate the impact of CFTR depletion on FA uptake, composition and metabolism using the intestinal Caco-2/15 cell line. shRNA-mediated cftr gene silencing induced qualitative and quantitative modifications in FA composition in differentiated enterocytes as determined by gas-liquid chromatography. With the cftr gene disruption, there was a 1,5 fold increase in the total FA amount, largely attributable to monounsaturated and saturated FA compared to controls. The activity of delta-7 desaturase, estimated by the 16:1(n-7/16:0, was significantly higher in knockdown cells and consistent with the striking elevation of the n-7 FA family. When incubated with [14C]-oleic acid, CFTR-depleted cells were capable of quick incorporation and export to the medium concomitantly with the high protein expression of L-FABP known to promote intracellular FA trafficking. Accordingly, lipoprotein vehicles (CM, VLDL, LDL and HDL, isolated from CFTR knockdown cells, exhibited higher levels of radiolabeled FA. Moreover, in the presence of [14C]-acetate, knockdown cells exhibited enhanced secretion of newly synthesized phospholipids, triglycerides, cholesteryl esters and free FA, thereby suggesting a stimulation of the lipogenic pathway. Conformably, gene expression of SREBP-1c, a key lipogenic transcription factor, was increased while protein expression of the phosphorylated and inactive form of acetylCoA carboxylase was reduced, confirming lipogenesis induction. Finally, CFTR-depleted cells exhibited lower gene expression of transcription factors (PPARalpha, LXRalpha, LXRbeta and RXRalpha

Depletion of endogenous germ cells in tree shrews in preparation for spermatogonial transplantation.

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Liu, Tingting; Guo, Ying; Yan, Lanzhen; Sun, Bin; Zheng, Ping; Zhao, Xudong

2017-09-01

To achieve successful spermatogonial transplantation, endogenous germ cells must be depleted in recipient animals to allow donor germ cells to colonize efficiently. Busulfan is commonly used for the depletion of endogenous germ cells in recipient males. However, the optimal dose of busulfan is species-specific, and the optimal dose in tree shrews is yet to be determined. The current study aimed to determine the optimal dose of busulfan for effective suppression of endogenous spermatogenesis in tree shrews. Different doses (15, 20, 25, 30, 35, 40 and 45 mg/kg) of busulfan were injected into tree shrews intraperitoneally. Survival rates of the different treatment groups were calculated at 2 weeks and body weights were measured at 4, 6, 8, 10 and 28 weeks post-busulfan treatment. The testes were also removed and weighed at 4, 6, 8, 10 and 28 weeks post-treatment, and the cross and longitude diameters of the testes and diameters of the seminiferous tubules were measured and histologically evaluated. It was observed that there were no significant differences in the survival rates between the 15-35 mg/kg treatment groups and the control group (P>0.05), while the survival rate of the 40 mg/kg treatment group significantly decreased relative to the control group (Pendogenous germ cells in tree shrews. This dose led to maximum suppression of endogenous spermatogenesis while maintaining an acceptable survival rate of >50% of the lethal dose of busulfan for tree shrews.

Nitric oxide and DOPAC-induced cell death: from GSH depletion to mitochondrial energy crisis.

Science.gov (United States)

Nunes, Carla; Barbosa, Rui M; Almeida, Leonor; Laranjinha, João

2011-09-01

The molecular mechanisms inherent to cell death associated with Parkinson's disease are not clearly understood. Diverse pathways, sequence of events and models have been explored in several studies. Recently, we have proposed an integrative mechanism, encompassing the interaction of nitric oxide (•NO) and a major dopamine metabolite, dihydroxyphenylacetic (DOPAC), leading to a synergistic mitochondrial dysfunction and cell death that may be operative in PD. In this study, we have studied the sequence of events underlying the mechanisms of cell death in PC12 cells exposed to •NO and DOPAC in terms of: a) free radical production; b) modulation by glutathione (GSH); c) energetic status and d) outer membrane mitochondria permeability. Using Electron Paramagnetic Resonance (EPR) it is shown the early production of oxygen free radicals followed by a depletion of GSH reflected by an increase of GSSG/GSH ratio in the cells treated with the mixture of •NO/DOPAC, as compared with the cells individually exposed to each of the stimulus. Glutathione ethyl ester (GSH-EE) and N-acetylcysteine (NAC) may rescue cells from death, increasing GSH content and preventing ATP loss in cells treated with the mixture DOPAC/•NO but failed to exert similar effects in the cells challenged only with •NO. The depletion of GSH is accompanied by a decreased activity of mitochondrial complex I. At a later stage, the concerted action of DOPAC and •NO include a rise in the ratio Bax/Bcl-2, an observation not evident when cells were exposed only to •NO. The results support a free radical-induced pathway leading to cell death involving the concerted action of DOPAC and •NO and the critical role of GSH in maintaining a functional mitochondria. Copyright © 2011 Elsevier Inc. All rights reserved.

Depletion of kinesin 5B affects lysosomal distribution and stability and induces peri-nuclear accumulation of autophagosomes in cancer cells

DEFF Research Database (Denmark)

Cardoso, Carla M P; Groth-Pedersen, Line; Høyer-Hansen, Maria

2009-01-01

BACKGROUND: Enhanced lysosomal trafficking is associated with metastatic cancer. In an attempt to discover cancer relevant lysosomal motor proteins, we compared the lysosomal proteomes from parental MCF-7 breast cancer cells with those from highly invasive MCF-7 cells that express an active form...... in HeLa cervix carcinoma cells as analyzed by subcellular fractionation. The depletion of KIF5B triggered peripheral aggregations of lysosomes followed by lysosomal destabilization, and cell death in HeLa cells. Lysosomal exocytosis in response to plasma membrane damage as well as fluid phase...... cells. In KIF5B-depleted cells the autophagosomes formed and accumulated in the close proximity to the Golgi apparatus, whereas in the control cells they appeared uniformly distributed in the cytoplasm. CONCLUSIONS/SIGNIFICANCE: Our data identify KIF5B as a cancer relevant lysosomal motor protein...

CD3+CD8+CD161high Tc17 cells are depleted in HIV-infection

DEFF Research Database (Denmark)

Gaardbo, Julie Christine; Hartling, Hans Jakob; Thorsteinsson, Kristina

2012-01-01

CD8+ Tc17 cells with pro-inflammatory properties have only recently been acknowledged, and Tc17 cells in HIV-infection are undescribed. CD3+CD8+CD161 Tc17 cells and the production of Interleukin-17 were examined in untreated and treated HIV-infected patients, HIV-HCV co-infected patients...... and healthy controls. Depletion of CD3+CD8+CD161 Tc17 cells and diminished production of Interleukin-17 in HIV-infected patients was found. The level of Tc17 cells was associated with the level of the CD4+ count in treated patients....

CERT depletion predicts chemotherapy benefit and mediates cytotoxic and polyploid‐specific cancer cell death through autophagy induction

DEFF Research Database (Denmark)

Lee, Alvin J. X.; Roylance, Rebecca; Sander, Jil

2012-01-01

cell microscopy analysis revealed that CERT depletion induces LAMP2‐dependent death of polyploid cells following exit from mitosis in the presence of paclitaxel. We find that CERT is relatively over‐expressed in HER2+ breast cancer and CERT protein expression acts as an independent prognostic variable...

Halo Star Lithium Depletion

International Nuclear Information System (INIS)

Pinsonneault, M. H.; Walker, T. P.; Steigman, G.; Narayanan, Vijay K.

1999-01-01

The depletion of lithium during the pre-main-sequence and main-sequence phases of stellar evolution plays a crucial role in the comparison of the predictions of big bang nucleosynthesis with the abundances observed in halo stars. Previous work has indicated a wide range of possible depletion factors, ranging from minimal in standard (nonrotating) stellar models to as much as an order of magnitude in models that include rotational mixing. Recent progress in the study of the angular momentum evolution of low-mass stars permits the construction of theoretical models capable of reproducing the angular momentum evolution of low-mass open cluster stars. The distribution of initial angular momenta can be inferred from stellar rotation data in young open clusters. In this paper we report on the application of these models to the study of lithium depletion in main-sequence halo stars. A range of initial angular momenta produces a range of lithium depletion factors on the main sequence. Using the distribution of initial conditions inferred from young open clusters leads to a well-defined halo lithium plateau with modest scatter and a small population of outliers. The mass-dependent angular momentum loss law inferred from open cluster studies produces a nearly flat plateau, unlike previous models that exhibited a downward curvature for hotter temperatures in the 7Li-Teff plane. The overall depletion factor for the plateau stars is sensitive primarily to the solar initial angular momentum used in the calibration for the mixing diffusion coefficients. Uncertainties remain in the treatment of the internal angular momentum transport in the models, and the potential impact of these uncertainties on our results is discussed. The 6Li/7Li depletion ratio is also examined. We find that the dispersion in the plateau and the 6Li/7Li depletion ratio scale with the absolute 7Li depletion in the plateau, and we use observational data to set bounds on the 7Li depletion in main-sequence halo

Sequential Dysfunction and Progressive Depletion of Candida albicans-Specific CD4 T Cell Response in HIV-1 Infection

Science.gov (United States)

Liu, Fengliang; Fan, Xiuzhen; Auclair, Sarah; Ferguson, Monique; Sun, Jiaren; Soong, Lynn; Hou, Wei; Redfield, Robert R.; Birx, Deborah L.; Ratto-Kim, Silvia; Robb, Merlin L.; Kim, Jerome H.; Michael, Nelson L.; Hu, Haitao

2016-01-01

Loss of immune control over opportunistic infections can occur at different stages of HIV-1 (HIV) disease, among which mucosal candidiasis caused by the fungal pathogen Candida albicans (C. albicans) is one of the early and common manifestations in HIV-infected human subjects. The underlying immunological basis is not well defined. We have previously shown that compared to cytomegalovirus (CMV)-specific CD4 cells, C. albicans-specific CD4 T cells are highly permissive to HIV in vitro. Here, based on an antiretroviral treatment (ART) naïve HIV infection cohort (RV21), we investigated longitudinally the impact of HIV on C. albicans- and CMV-specific CD4 T-cell immunity in vivo. We found a sequential dysfunction and preferential depletion for C. albicans-specific CD4 T cell response during progressive HIV infection. Compared to Th1 (IFN-γ, MIP-1β) functional subsets, the Th17 functional subsets (IL-17, IL-22) of C. albicans-specific CD4 T cells were more permissive to HIV in vitro and impaired earlier in HIV-infected subjects. Infection history analysis showed that C. albicans-specific CD4 T cells were more susceptible to HIV in vivo, harboring modestly but significantly higher levels of HIV DNA, than CMV-specific CD4 T cells. Longitudinal analysis of HIV-infected individuals with ongoing CD4 depletion demonstrated that C. albicans-specific CD4 T-cell response was preferentially and progressively depleted. Taken together, these data suggest a potential mechanism for earlier loss of immune control over mucosal candidiasis in HIV-infected patients and provide new insights into pathogen-specific immune failure in AIDS pathogenesis. PMID:27280548

Suppression of IL-12p70 formation by IL-2 or following macrophage depletion causes T-cell autoreactivity leading to CNS demyelination in HSV-1-infected mice.

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Dhong Hyun Lee

2017-05-01

Full Text Available We have established two mouse models of central nervous system (CNS demyelination that differ from most other available models of multiple sclerosis (MS in that they represent a mixture of viral and immune triggers. In the first model, ocular infection of different strains of mice with a recombinant HSV-1 that expresses murine IL-2 constitutively (HSV-IL-2 causes CNS demyelination. In the second model, depletion of macrophages causes CNS demyelination in mice that are ocularly infected with wild-type (WT HSV-1. In the present study, we found that the demyelination in macrophage-intact mice infected with HSV-IL-2 was blocked by depletion of FoxP3-expressing cells, while concurrent depletion of macrophages restored demyelination. In contrast, demyelination was blocked in the macrophage-depleted mice infected with wild-type HSV-1 following depletion of FoxP3-expressing cells. In macrophage-depleted HSV-IL-2-infected mice, demyelination was associated with the activity of both CD4+ and CD8+ T cells, whereas in macrophage-depleted mice infected with WT HSV-1, demyelination was associated with CD4+ T cells. Macrophage depletion or infection with HSV-IL-2 caused an imbalance of T cells and TH1 responses as well as alterations in IL-12p35 and IL-12p40 but not other members of the IL-12 family or their receptors. Demyelination was blocked by adoptive transfer of macrophages that were infected with HSV-IL-12p70 or HSV-IL-12p40 but not by HSV-IL-12p35. These results indicate that suppression of IL-12p70 formation by IL-2 or following macrophage depletion causes T-cell autoreactivity leading to CNS demyelination in HSV-1-infected mice.

Depletion of regulatory T cells in a hapten-induced inflammation model results in prolonged and increased inflammation driven by T cells

DEFF Research Database (Denmark)

Christensen, A. D.; Skov, Søren; Kvist, P. H.

2015-01-01

Regulatory T cells (Tregs ) are known to play an immunosuppressive role in the response of contact hypersensitivity (CHS), but neither the dynamics of Tregs during the CHS response nor the exaggerated inflammatory response after depletion of Tregs has been characterized in detail. In this study we...... show that the number of Tregs in the challenged tissue peak at the same time as the ear-swelling reaches its maximum on day 1 after challenge, whereas the number of Tregs in the draining lymph nodes peaks at day 2. As expected, depletion of Tregs by injection of a monoclonal antibody to CD25 prior...

Depletion of kidney CD11c+ F4/80+ cells impairs the recovery process in ischaemia/reperfusion-induced acute kidney injury.

Science.gov (United States)

Kim, Myung-Gyu; Boo, Chang Su; Ko, Yoon Sook; Lee, Hee Young; Cho, Won Yong; Kim, Hyoung Kyu; Jo, Sang-Kyung

2010-09-01

Recent studies provided evidence of the potential role of CD11c(+) F4/80(+) dendritic subset in mediating injury and repair. The purpose of this study was to examine the role of kidney CD11c(+) F4/80(+) dendritic subset in the recovery phase of ischaemia/reperfusion injury (IRI). Following ischaemia/reperfusion (I/R), liposome clodronate or phosphate buffered saline (PBS) was administered, and on day 7 biochemical and histologic kidney damage was assessed. Activation and depletion of CD11c(+) F4/80(+) dendritic subset were confirmed by flow cytometry. Isolation of kidney CD11c(+) cells on days 1 and 7 with in vitro culture for measuring cytokines was performed to define functional characteristics of these cells, and adoptive transfer of CD11c(+) cells was also done. Following kidney IRI, the percentage of CD11c(+) F4/80(+) kidney dendritic cell subset that co-expresses maturation marker increased. Liposome clodronate injection after I/R resulted in preferential depletion of CD11c(+) F4/80(+) kidney dendritic subset, and depletion of these cells was associated with persistent kidney injury, more apoptosis, inflammation and impaired tubular cell proliferation. CD11c(+) F4/80(+) cell depletion was also associated with higher tissue levels of pro-inflammatory cytokines and lower level of IL-10, indicating the persistence of inflammatory milieu. Isolated kidney CD11c(+) cells on day 7 showed different phenotype with increased production of IL-10 compared with those on day 1. Adoptive transfer of CD11c(+) cells partially reversed impaired tissue recovery. Our results suggest that kidney CD11c(+) F4/80(+) dendritic subset might contribute to the recovery process by dynamic phenotypic change from pro-inflammatory to anti-inflammatory with modulation of immune response.

Calcium-dependent depletion zones in the cortical microtubule array coincide with sites of, but do not regulate, wall ingrowth papillae deposition in epidermal transfer cells

Science.gov (United States)

Zhang, Hui-ming; Talbot, Mark J.; McCurdy, David W.; Patrick, John W.; Offler, Christina E.

2015-01-01

Trans-differentiation to a transfer-cell morphology is characterized by the localized deposition of wall ingrowth papillae that protrude into the cytosol. Whether the cortical microtubule array directs wall ingrowth papillae formation was investigated using a Vicia faba cotyledon culture system in which their adaxial epidermal cells were spontaneously induced to trans-differentiate to transfer cells. During deposition of wall ingrowth papillae, the aligned cortical microtubule arrays in precursor epidermal cells were reorganized into a randomized array characterized by circular depletion zones. Concurrence of the temporal appearance, spatial pattern, and size of depletion zones and wall ingrowth papillae was consistent with each papilla occupying a depletion zone. Surprisingly, microtubules appeared not to regulate construction of wall ingrowth papillae, as neither depolymerization nor stabilization of cortical microtubules changed their deposition pattern or morphology. Moreover, the size and spatial pattern of depletion zones was unaltered when the formation of wall ingrowth papillae was blocked by inhibiting cellulose biosynthesis. In contrast, the depletion zones were absent when the cytosolic calcium plumes, responsible for directing wall ingrowth papillae formation, were blocked or dissipated. Thus, we conclude that the depletion zones within the cortical microtubule array result from localized depolymerization of microtubules initiated by elevated cytosolic Ca2+ levels at loci where wall ingrowth papillae are deposited. The physiological significance of the depletion zones as a mechanism to accommodate the construction of wall ingrowth papillae without compromising maintenance of the plasma membrane–microtubule inter-relationship is discussed. PMID:26136268

Depletion of the excited state population in negative ions using laser photodetachment in a gas-filled RF quadrupole ion guide

Energy Technology Data Exchange (ETDEWEB)

Lindahl, A O; Hanstorp, D [Department of Physics, University of Gothenburg, SE-412 96 Gothenburg (Sweden); Forstner, O [VERA Laboratory, Faculty of Physics, Universitaet Wien, Vienna (Austria); Gibson, N D [Department of Physics and Astronomy, Denison University, Granville, OH 43023 (United States); Gottwald, T; Wendt, K [Institut fuer Physik, Johannes Gutenberg-Universitaet, Mainz, 55099 Mainz (Germany); Havener, C C; Liu, Y, E-mail: Dag.Hanstorp@physics.gu.s [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6368 (United States)

2010-06-14

The depopulation of excited states in beams of negatively charged carbon and silicon ions was demonstrated using collisional detachment and laser photodetachment in a radio-frequency quadrupole ion guide filled with helium. The high-lying, loosely bound {sup 2}D excited state in C{sup -} was completely depleted through collisional detachment alone, which was quantitatively determined within 6%. For Si{sup -} the combined signal from the population in the {sup 2}P and {sup 2}D excited states was only partly depleted through collisions in the cooler. The loosely bound {sup 2}P state was likely to be completely depopulated, and the more tightly bound {sup 2}D state was partly depopulated through collisions. 98(2)% of the remaining {sup 2}D population was removed by photodetachment in the cooler using less than 2 W laser power. The total reduction of the excited population in Si{sup -}, including collisional detachment and photodetachment, was estimated to be 99(1)%. Employing this novel technique to produce a pure ground state negative ion beam offers possibilities of enhancing selectivity, as well as accuracy, in high-precision experiments on atomic as well as molecular negative ions.

In ovo injection of anti-chicken CD25 monoclonal antibodies depletes CD4+CD25+ T cells in chickens.

Science.gov (United States)

Shanmugasundaram, Revathi; Selvaraj, Ramesh K

2013-01-01

The CD4(+)CD25(+) cells have T regulatory cell properties in chickens. This study investigated the effect of in ovo injection of anti-chicken CD25 monoclonal antibodies (0.5 mg/egg) on CD4(+)CD25(+) cell depletion and on amounts of interleukin-2 mRNA and interferon-γ mRNA in CD4(+)CD25(-) cells posthatch. Anti-chicken CD25 or PBS (control) was injected into 16-d-old embryos. Chicks hatched from eggs injected with anti-chicken CD25 antibodies had a lower CD4(+)CD25(+) cell percentage in the blood until 25 d posthatch. The anti-chicken CD25 antibody injection nearly depleted CD4(+)CD25(+) cells in the blood until 16 d posthatch. At 30 d posthatch, the CD4(+)CD25(+) cell percentage in the anti-CD25-antibody-injected group was comparable with the percentage in the control group. At 16 d posthatch, the anti-chicken CD25 antibody injection decreased CD4(+)CD25(+) cell percentages in the thymus, spleen, and cecal tonsils. Chickens hatched from anti-CD25-antibody-injected eggs had approximately 25% of CD4(+)CD25(+) cells in the cecal tonsils and thymus compared with those in the cecal tonsils and thymus of the control group. The CD4(+)CD25(-) cells from the spleen and cecal tonsils of chicks hatched from anti-chicken-CD25-injected eggs had higher amounts of interferon-γ and interleukin-2 mRNA than CD4(+)CD25(-) cells from the control group. It could be concluded that injecting anti-chicken CD25 antibodies in ovo at 16 d of incubation nearly depleted the CD4(+)CD25(+) cells until 25 d posthatch.

B-cell inhibition by cross-linking CD79b is superior to B-cell depletion with anti-CD20 antibodies in treating murine collagen-induced arthritis

Czech Academy of Sciences Publication Activity Database

Bruhl, H.; Cihak, J.; Talke, Y.; Rodriguez-Gomez, M.; Hermann, F.; Goebel, N.; Renner, K.; Plachý, Jiří; Stangassinger, M.; Archemann, S.; Nimmerjahn, F.; Mack, M.

2015-01-01

Roč. 45, č. 3 (2015), s. 705-715 ISSN 0014-2980 Institutional support: RVO:68378050 Keywords : Arthritis * B cells * B-cell depletion * B-cell inhibition * CD79b * Humoral immune response Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.179, year: 2015

Effects of depletion of dihydropyrimidine dehydrogenase on focus formation and RPA phosphorylation.

Science.gov (United States)

Someya, Masanori; Sakata, Koh-ichi; Matsumoto, Yoshihisa; Tauchi, Hiroshi; Kai, Masahiro; Hareyama, Masato; Fukushima, Masakazu

2012-01-01

Gimeracil, an inhibitor of dihydropyrimidine dehydrogenase (DPYD), partially inhibits homologous recombination (HR) repair and has a radiosensitizing effect as well as enhanced sensitivity to Camptothecin (CPT). DPYD is the target protein for radiosensitization by Gimeracil. We investigated the mechanisms of sensitization of radiation and CPT by DPYD inhibition using DLD-1 cells treated with siRNA for DPYD. We investigated the focus formation of various kinds of proteins involved in HR and examined the phosphorylation of RPA by irradiation using Western blot analysis. DPYD depletion by siRNA significantly restrained the formation of radiation-induced foci of Rad51 and RPA, whereas it increased the number of foci of NBS1. The numbers of colocalization of NBS1 and RPA foci in DPYD-depleted cells after radiation were significantly smaller than in the control cells. These results suggest that DPYD depletion is attributable to decreased single-stranded DNA generated by the Mre11/Rad50/NBS1 complex-dependent resection of DNA double-strand break ends. The phosphorylation of RPA by irradiation was partially suppressed in DPYD-depleted cells, suggesting that DPYD depletion may partially inhibit DNA repair with HR by suppressing phosphorylation of RPA. DPYD depletion showed a radiosensitizing effect as well as enhanced sensitivity to CPT. The radiosensitizing effect of DPYD depletion plus CPT was the additive effect of DPYD depletion and CPT. DPYD depletion did not have a cell-killing effect, suggesting that DPYD depletion may not be so toxic. Considering these results, the combination of CPT and drugs that inhibit DPYD may prove useful for radiotherapy as a method of radiosensitization.

GROWTH-INHIBITION OF 2 SOLID TUMORS IN MICE, CAUSED BY POLYAMINE DEPLETION, IS NOT ATTENDED BY ALTERATIONS IN CELL-CYCLE PHASE DISTRIBUTION

NARCIS (Netherlands)

HESSELS, J; KINGMA, AW; MUSKIET, FAJ; SARHAN, S; SEILER, N

1991-01-01

We studied the effect of polyamine depletion on growth and cell cycle characteristics of subcutaneously grown Lewis lung carcinoma (LLC) and fibrosarcoma (FIO 26) in mice. Polyamine depletion was achieved by inhibition of ornithine decarboxylase using 2-(difluoromethyl)ornithine, limitation of

Dose-response studies of depletion and repopulation of rat intestinal mucosal mast cells after irradiation

International Nuclear Information System (INIS)

Sedgwick, D.M.; Ferguson, A.

1994-01-01

The effects of radiation on gut mucosal mast cells (MMC) and tissue eosinophils were examined. Groups of rats were given single doses of whole-body irradiation from 0.5 to 5 Gy. Serum rat mast cell protease II (RMCPII) concentration showed a significant dose-dependent fall after 1 Gy on day 3 and 1.5 Gy on day 7. MMC counts and tissue RMCPII values on day 7 decreased significantly by 70% after 1 Gy and were undetectable with larger doses. Rats with normal and expanded MMC populations were irradiated or given anaphylaxis. Serum RMCPII concentrations did not change after irradiation, but there was a 10-fold increase in RMCPII after anaphylaxis. Tissue eosinophils in jejunum were 50% of control at 7 days after 2 Gy, and this effect was progressively more marked with higher doses. Similar effects on MMC and eosinophils were demonstrated in ileum, ascending colon and rectum. After 4.5 Gy, repopulation of the gut with MMC did not occur until week 3-4 postirradiation and MMC counts were still 50% below those of controls at 5 weeks postirradiation. Counts of tisse eosinophils 5 weeks after 4.5 Gy irradiation had returned to control levels in jejunum but were still significantly depleted in colon. (Author)

In vivo dendritic cell depletion reduces breeding efficiency, affecting implantation and early placental development in mice.

Science.gov (United States)

Krey, Gesa; Frank, Pierre; Shaikly, Valerie; Barrientos, Gabriela; Cordo-Russo, Rosalia; Ringel, Frauke; Moschansky, Petra; Chernukhin, Igor V; Metodiev, Metodi; Fernández, Nelson; Klapp, Burghard F; Arck, Petra C; Blois, Sandra M

2008-09-01

Implantation of mammalian embryos into their mother's uterus ensures optimal nourishment and protection throughout development. Complex molecular interactions characterize the implantation process, and an optimal synchronization of the components of this embryo-maternal dialogue is crucial for a successful reproductive outcome. In the present study, we investigated the role of dendritic cells (DC) during implantation process using a transgenic mouse system (DTRtg) that allows transient depletion of CD11c+ cells in vivo through administration of diphtheria toxin. We observed that DC depletion impairs the implantation process, resulting in a reduced breeding efficiency. Furthermore, the maturity of uterine natural killer cells at dendritic cell knockout (DCKO) implantation sites was affected as well; as demonstrated by decreased perforin expression and reduced numbers of periodic-acid-Schiff (PAS)-positive cells. This was accompanied by disarrangements in decidual vascular development. In the present study, we were also able to identify a novel DC-dependent protein, phosphatidylinositol transfer protein beta (PITPbeta), involved in implantation and trophoblast development using a proteomic approach. Indeed, DCKO mice exhibited substantial anomalies in placental development, including hypocellularity of the spongiotrophoblast and labyrinthine layers and reduced numbers of trophoblast giant cells. Giant cells also down-regulated their expression of two characteristic markers of trophoblast differentiation, placental lactogen 1 and proliferin. In view of these findings, dendritic cells emerge as possible modulators in the orchestration of events leading to the establishment and maintenance of pregnancy.

Factors involved in depletion of glutathione from A549 human lung carcinoma cells: implications for radiotherapy

International Nuclear Information System (INIS)

Biaglow, J.E.; Varnes, M.E.; Epp, E.R.; Clark, E.P.

1984-01-01

The rate of GSH resynthesis has been measured in plateau phase cultures of A549 human lung carcinoma cells subjected to a fresh medium change. Buthionine sulfoximine (BSO) blocks this resynthesis. Diethyl maleate (DEM) causes a decrease in accumulation of GSH. If DEM is added concurrently with BSO there is a rapid decline in GSH that is maximal in the presence of 0.5 mM DEM. GSH depletion rapidly occurs when BSO is added to log phase cultures which initially are higher in GSH content. Twenty-four hr treatment of A549 cells with BSO results in cells that are more radiosensitive in air and show a slight hypoxic radiation response. A 2 hr treatment with DEM results in some hypoxic sensitization and little increase in the aerobic radiation response. Cells treated simultaneously with BSO + DEM show little increase in the hypoxic radiation response, compared to DEM alone, but are more sensitive under aerobic conditions. Decreased cell survival for aerobically irradiated log phase A549 cells occurs within minutes after addition of a mixture of BSO + DEM. The authors suggest that the enhanced aerobic radiation response is related to an inability of GSH depleted cells to inactivate either peroxy radicals or hydroperoxides that may be produced during irradiation of BSO treated cells. Furthermore, enhancement of the aerobic radiation response may be useful in vivo if normal tissue responses are not also increased

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

Science.gov (United States)

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

2015-11-18

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

Determination of Mother Centriole Maturation in CPAP-Depleted Cells Using the Ninein Antibody

OpenAIRE

Lee, Miseon; Rhee, Kunsoo

2015-01-01

Background Mutations in centrosomal protein genes have been identified in a number of genetic diseases in brain development, including microcephaly. Centrosomal P4.1-associated protein (CPAP) is one of the causal genes implicated in primary microcephaly. We previously proposed that CPAP is essential for mother centriole maturation during mitosis. Methods We immunostained CPAP-depleted cells using the ninein antibody, which selectively detects subdistal appendages in mature mother centrioles. ...

Calcium-dependent depletion zones in the cortical microtubule array coincide with sites of, but do not regulate, wall ingrowth papillae deposition in epidermal transfer cells.

Science.gov (United States)

Zhang, Hui-ming; Talbot, Mark J; McCurdy, David W; Patrick, John W; Offler, Christina E

2015-09-01

Trans-differentiation to a transfer-cell morphology is characterized by the localized deposition of wall ingrowth papillae that protrude into the cytosol. Whether the cortical microtubule array directs wall ingrowth papillae formation was investigated using a Vicia faba cotyledon culture system in which their adaxial epidermal cells were spontaneously induced to trans-differentiate to transfer cells. During deposition of wall ingrowth papillae, the aligned cortical microtubule arrays in precursor epidermal cells were reorganized into a randomized array characterized by circular depletion zones. Concurrence of the temporal appearance, spatial pattern, and size of depletion zones and wall ingrowth papillae was consistent with each papilla occupying a depletion zone. Surprisingly, microtubules appeared not to regulate construction of wall ingrowth papillae, as neither depolymerization nor stabilization of cortical microtubules changed their deposition pattern or morphology. Moreover, the size and spatial pattern of depletion zones was unaltered when the formation of wall ingrowth papillae was blocked by inhibiting cellulose biosynthesis. In contrast, the depletion zones were absent when the cytosolic calcium plumes, responsible for directing wall ingrowth papillae formation, were blocked or dissipated. Thus, we conclude that the depletion zones within the cortical microtubule array result from localized depolymerization of microtubules initiated by elevated cytosolic Ca(2+) levels at loci where wall ingrowth papillae are deposited. The physiological significance of the depletion zones as a mechanism to accommodate the construction of wall ingrowth papillae without compromising maintenance of the plasma membrane-microtubule inter-relationship is discussed. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Self-assembled, nanowire network electrodes for depleted bulk heterojunction solar cells

KAUST Repository

Lan, Xinzheng; Bai, Jing; Masala, Silvia; Thon, Susanna; Ren, Yuan; Kramer, Illan J.; Hoogland, Sjoerd H.; Simchi, Arash; Koleilat, Ghada I.; Paz-Soldan, Daniel; Ning, Zhijun; Labelle, André J.; Kim, Jinyoung; Jabbour, Ghassan E.; Sargent, E. H.

2013-01-01

Herein, a solution-processed, bottom-up-fabricated, nanowire network electrode is developed. This electrode features a ZnO template which is converted into locally connected, infiltratable, TiO2 nanowires. This new electrode is used to build a depleted bulk heterojunction solar cell employing hybrid-passivated colloidal quantum dots. The new electrode allows the application of a thicker, and thus more light-absorbing, colloidal quantum dot active layer, from which charge extraction of an efficiency comparable to that obtained from a thinner, planar device could be obtained. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Self-assembled, nanowire network electrodes for depleted bulk heterojunction solar cells

KAUST Repository

Lan, Xinzheng

2013-01-06

Herein, a solution-processed, bottom-up-fabricated, nanowire network electrode is developed. This electrode features a ZnO template which is converted into locally connected, infiltratable, TiO2 nanowires. This new electrode is used to build a depleted bulk heterojunction solar cell employing hybrid-passivated colloidal quantum dots. The new electrode allows the application of a thicker, and thus more light-absorbing, colloidal quantum dot active layer, from which charge extraction of an efficiency comparable to that obtained from a thinner, planar device could be obtained. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of electron affinic hypoxic cell sensitizers on the radiolytic depletion of oxygen in mammalian cells irradiated at ultrahigh dose rates

International Nuclear Information System (INIS)

Michaels, H.B.

1982-01-01

When CHO cells are equilibrated with a low level of oxygen (e.g. 0.4% O 2 ) and irradiated with single 3 ns pulses of electrons, a breaking survival curve is observed. This effect is believed to be the result of radiolytic oxygen depletion and can be prevented by the presence of a relatively low concentraton of hypoxic cell radiosensitizer. This prevention of the breaking survival curve has been observed for 2- and 5-nitroimidazoles, nitrofurans, and diamide. It is hypothesized that the sensitizer acts by competing wth oxygen for the radiation-induced intracellular oxygen-binding species, perhaps a hydrated electron adduct, leaving oxygen free to participate in radiosensitization reactions during the lifetime of the oxygen-sensitive radiation-induced target sites for lethal damage, probably DNA radicals produced by hydroxyl radical attack. The proposed role of the sensitizer in the interference with oxygen depletion is a transient phenomenon, occuring on the microsecond to millisecond time scale

Stimulated emission depletion following two photon excitation

OpenAIRE

Marsh, R. J.; Armoogum, D. A.; Bain, A. J.

2002-01-01

The technique of stimulated emission depletion of fluorescence (STED) from a two photon excited molecular population is demonstrated in the S, excited state of fluorescein in ethylene glycol and methanol. Two photon excitation (pump) is achieved using the partial output of a regeneratively amplified Ti:Sapphire laser in conjunction with an optical parametric amplifier whose tuneable output provides a synchronous depletion (dump) pulse. Time resolved fluorescence intensity and anisotropy measu...

Iron depletion in HCT116 cells diminishes the upregulatory effect of phenethyl isothiocyanate on heme oxygenase-1

International Nuclear Information System (INIS)

Bolloskis, Michael P.; Carvalho, Fabiana P.; Loo, George

2016-01-01

Some of the health-promoting properties of cruciferous vegetables are thought to be partly attributed to isothiocyanates. These phytochemicals can upregulate the expression of certain cytoprotective stress genes, but it is unknown if a particular nutrient is involved. Herein, the objective was to ascertain if adequate iron is needed for enabling HCT116 cells to optimally express heme oxygenase-1 (HO-1) when induced by phenethyl isothiocyanate (PEITC). PEITC increased HO-1 expression and also nuclear translocation of Nrf2, which is a transcription factor known to activate the HO-1 gene. However, in HCT116 cells that were made iron-deficient by depleting intracellular iron with deferoxamine (DFO), PEITC was less able to increase HO-1 expression and nuclear translocation of Nrf2. These suppressive effects of DFO were overcome by replenishing the iron-deficient cells with the missing iron. To elucidate these findings, it was found that PEITC-induced HO-1 upregulation can be inhibited with thiol antioxidants (glutathione and N-acetylcysteine). Furthermore, NADPH oxidase inhibitors (diphenyleneiodonium and apocynin) and a superoxide scavenger (Tiron) each inhibited PEITC-induced HO-1 upregulation. In doing so, diphenyleneiodonium was the most potent and also inhibited nuclear translocation of redox-sensitive Nrf2. Collectively, the results imply that the HO-1 upregulation by PEITC involves an iron-dependent, oxidant signaling pathway. Therefore, it is concluded that ample iron is required to enable PEITC to fully upregulate HO-1 expression in HCT116 cells. As such, it is conceivable that iron-deficient individuals may not reap the full health benefits of eating PEITC-containing cruciferous vegetables that via HO-1 may help protect against multiple chronic diseases. - Highlights: • PEITC increased HO-1 expression in HCT116 cells. • PEITC-induced HO-1 upregulation was impaired in iron-depleted HCT116 cells. • Impairment of PEITC-induced HO-1 upregulation was

Intracellular energy depletion triggers programmed cell death during petal senescence in tulip.

Science.gov (United States)

Azad, A K; Ishikawa, Takayuki; Ishikawa, Takahiro; Sawa, Y; Shibata, H

2008-01-01

Programmed cell death (PCD) in petals provides a model system to study the molecular aspects of organ senescence. In this study, the very early triggering signal for PCD during the senescence process from young green buds to 14-d-old petals of Tulipa gesneriana was determined. The opening and closing movement of petals of intact plants increased for the first 3 d and then gradually decreased. DNA degradation and cytochrome c (Cyt c) release were clearly observed in 6-d-old flowers. Oxidative stress or ethylene production can be excluded as the early signal for petal PCD. In contrast, ATP was dramatically depleted after the first day of flower opening. Sucrose supplementation to cut flowers maintained their ATP levels and the movement ability for a longer time than in those kept in water. The onset of DNA degradation, Cyt c release, and petal senescence was also delayed by sucrose supplementation to cut flowers. These results suggest that intracellular energy depletion, rather than oxidative stress or ethylene production, may be the very early signal to trigger PCD in tulip petals.

The toxic effects, GSH depletion and radiosensitivity by BSO on retinoblastoma

International Nuclear Information System (INIS)

Yi Xianjin; Ni Chuo; Wang Wengi; Li Ding; Jin Yizun

1993-01-01

Retinoblastoma is the most common intraocular malignant tumor in children. Previous investigations have reported that buthionine sulfoximine (BSO) can deplete intracellular glutathione (GSH) by the specific inhibition and increase cellular radiosensitivity. The toxic effects, GSH depletion and radiosensitivity of BSO on retinoblastoma were reported. GSH content of retinoblastoma cell lines Y-79, So-Rb50 and retinoblastoma xenograft is (2.7 +- 1.3) x 10 -12 mmol/cell, (1.4 +- 0.2) x 10 -12 mmol/cell, and 2.8 +- 1.2 μmol/g respectively. The ID50 of BSO on Y-79 and So-Rb50 in air for 3h exposure is 2.5 mM and 0.2 mM respectively. GSH depletion by 0.1 mM BSO for 24h on Y-79 cells and 0.01 mM BSO for 24 h on So-Rb50 cells is 16.35%, and 4.7% of control. GSH depletion in tumor and other organ tissues in retinoblastoma bearing nude mice after BSO administration is differential. BSH depletion after BSO exposure in Y-79 cells in vitro decrease the D 0 value of retinoblastoma cells. The SER of 0.01 mM and 0.05 mM BSO for 24 h under the hypoxic condition is 1.21 and 1.36 respectively. Based on these observations, the authors conclude that BSO toxicity on retinoblastoma cells depends on the characteristics of cell line and BSO can increase hypoxic retinoblastoma cells radiosensitivity in vitro. Further study of BSO radiosensitization on retinoblastoma in vivo using nude mouse xenograft is needed

T-cell depleted haploidentical three loci mismatched bone-marrow and peripheral blood stem cell transplantation in acute leukaemia patients

International Nuclear Information System (INIS)

Aristei, C.; Aversa, F.; Panizza, B.M.; Perrucci, E.; Barone, V.; Marafioti, L.; Raymondi, C.; Terenzi, A.; Martelli, M.F.; Latini, P.

1996-01-01

Objectives: Allogeneic bone-marrow transplantation (BMT) is an established treatment for many haematological malignancies. Unfortunately, most patients lack an HLA geno typically identical sibling and require an alternative donor, such as an HLA-haploidentical mismatched related donor, an HLA phenotypically matched or partially mismatched unrelated donor or an HLA-similar cord blood stem cell donor. However, these types of BMT increase the risk of graft-versus-host disease (GvHD), graft failure, delayed immuno reconstitution and fatal infection that observed after a sibling matched donor. Many centers are exploring the possibility of using donors other than matched sibling. Our approach has been to employ T-cell depleted mismatched haploidentical familial donor BMT to solve the problem of GvHD, a highly immuno- and myelo-suppressive conditioning regimen to reduce the incidence of graft failure and relapse, a graft inoculum plus G-CSF donor mobilized peripheral blood stem cells (PBSC) to overcome the host-versus-graft barrier. Patients and methods: Thirty-six patients (25 male, 11 female; median age 22 years, range 2-51) were treated with an allogeneic T-depleted haploidentical three loci mismatched bone-marrow and G-CSF mobilized PBSC transplantation from a familiar donor (18 siblings, 17 parents and 1 cousin) between March 1993 and June 1995. All had high-risk or advanced stage acute myeloid (12) or acute lymphoid (24) leukaemia; 18 were in haematological complete remission (CR) and 18 in chemo resistant relapse. Patients were conditioned with 8 Gy single dose TBI administered on day -5 at an instantaneous dose-rate of 13.4-31.7 cGy/min/midplane and average of 6.7-12.12 cGy/min/midplane. Shields were used to reduce the lung dose to 7 Gy in the first 23 cases and to 6 Gy in the last 13. 10 mg/Kg thiotepa were administered on day -4, 5 mg/Kg rabbit ATG from day -4 to day -1, 60 or 50 mg/Kg/cyclophosphamide on days -3 and -2. Bone-marrow and PBSC were infused on day

Vacuolar H+ -ATPase c protects glial cell death induced by sodium nitroprusside under glutathione-depleted condition.

Science.gov (United States)

Byun, Yu Jeong; Lee, Seong-Beom; Lee, Hwa Ok; Son, Min Jeong; Kim, Ho-Shik; Kwon, Oh-Joo; Jeong, Seong-Whan

2011-08-01

We examined the role of the c subunit (ATP6L) of vacuolar H(+) -ATPase and its molecular mechanisms in glial cell death induced by sodium nitroprusside (SNP). ATP6L siRNA-transfected cells treated with SNP showed a significant increase in cytotoxicity under glutathione (GSH)-depleted conditions after pretreatment with buthionine sulfoximine, but reduction of ATP6L did not affect the regulation of lysosomal pH in analyses with lysosomal pH-dependent fluorescence probes. Photodegraded SNP and ferrous sulfate induced cytotoxicity with the same pattern as that of SNP, but SNAP and potassium cyanide did not show activity. Pretreatment of the transfected cells with deferoxamine (DFO) reduced ROS production and significantly inhibited the cytotoxicity, which indicates that primarily iron rather than nitric oxide or cyanide from SNP contributes to cell death. Involvement of apoptotic processes in the cells was not shown. Pretreatment with JNK or p38 chemical inhibitor significantly inhibited the cytotoxicity, and we also confirmed that the MAPKs were activated in the cells by immunoblot analysis. Significant increase of LC3-II conversion was observed in the cells, and the conversions were inhibited by cotransfection of the MAPK siRNAs and pretreatment with DFO. Introduction of Atg5 siRNA inhibited the cytotoxicity and inhibited the activation of MAPKs and the conversion of LC3. We finally confirmed autophagic cell death and involvement of MAPKs by observation of autophagic vacuoles via electron microscopy. These data suggest that ATP6L has a protective role against SNP-induced autophagic cell death via inhibition of JNK and p38 in GSH-depleted glial cells. Copyright © 2011 Wiley-Liss, Inc.

The toxic effects, GSH depletion and radiosensitivity by BSO on retinoblastoma

International Nuclear Information System (INIS)

Xianjin Yi; Li Ding; Yizun Jin; Chuo Ni; Wenji Wang

1994-01-01

Retinoblastoma is the most common intraocular malignant tumor in children. Previous investigations have reported that buthionine sulfoximine (BSO) can deplete intracellular glutathione (GSH) by specific inhibition and increase cellular radiosensitivity. The toxic effects, GSH depletion and radiosensitivity effects of BSO on retinoblastoma cells are reported in this paper. GSH content of retinoblastoma cell lines Y-79, So-Rb50 and retinoblastoma xenograft is 2.7 ± 1.3 X 1.0 -12 mmol/cell, 1.4 ± 0.2 X 1.0 -12 mmol/cell, and 2.8 ± 1.2 μmol/g, respectively. The ID 50 of BSO on Y-79 and So-Rb50 in air for 3 h exposure is 2.5 mM and 0.2 mM, respectively. GSH depletion by 0.1 mM BSO for 24 h on Y-79 cells and 0.01 mM BSO for 24 h on So-Rb50 cells is 16.35%, and 4.7% of control. GSH depletion in tumor and other organ tissues in retinoblastoma-bearing nude mice after BSO administration is differential. GSH depletion after BSO exposure in Y-79 cells in vitro decreases the Do value of retinoblastoma cells. The SER of 0.01 mM and 0.05 mM BSO for 24 h under hypoxic conditions is 1.21 and 1.36, respectively. Based on these observations, the authors conclude that BSO toxicity on retinoblastoma cells depends on the characteristics of the cell line and that BSO can increase hypoxic retinoblastoma cells' radiosensitivity in vitro. Further study of BSO radiosensitization on retinoblastoma in vivo using nude mouse xenografts is needed. 25 refs., 3 figs., 3 tabs

Depleted Bulk Heterojunction Colloidal Quantum Dot Photovoltaics

KAUST Repository

Barkhouse, D. Aaron R.

2011-05-26

The first solution-processed depleted bulk heterojunction colloidal quantum dot solar cells are presented. The architecture allows for high absorption with full depletion, thereby breaking the photon absorption/carrier extraction compromise inherent in planar devices. A record power conversion of 5.5% under simulated AM 1.5 illumination conditions is reported. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Adenine nucleotide depletion from endothelial cells exposed to xanthine oxidase

International Nuclear Information System (INIS)

Aalto, T.K.; Raivio, K.O.

1990-01-01

Hypoxia causes breakdown of cellular nucleotides, accumulation of hypoxanthine (HX), and conversion of xanthine dehydrogenase into xanthine oxidase (XO). Upon reoxygenation, the HX-XO reaction generates free radicals, one potential mechanism of tissue damage. Because endothelial cells contain XO and are exposed to circulating HX, they are a likely target for damage. We studied the effect of XO and/or HX at physiologically relevant concentrations on nucleotide metabolism of cultured endothelial cells from human umbilical veins. Cells were labeled with [14C]adenine and incubated for up to 6 h with HX, XO, or both, in the absence or presence of serum. Adenine nucleotides from cell extracts and nucleotide breakdown products (HX, xanthine, and urate) from the medium were separated and counted. HX alone had no effect. XO (80 mU/ml) alone caused a 70% (no serum) or 40% (with serum) fall in adenine nucleotides and an equivalent increase of xanthine and urate. The combination of HX and XO caused a 90% (no serum) or 70% (with serum) decrease in nucleotides, decrease in energy charge, and detachment of cells from the culture plate. Nucleotide depletion was not accounted for by proteolytic activity in the XO preparation. Albumin was only half as effective as serum in preventing nucleotide loss. Thus exogenous XO, in the presence of endogenous HX, triggers adenine nucleotide catabolism, but endogenous XO activity is too low to influence nucleotide levels even at high exogenous HX concentrations. Serum limits the catabolic effect of XO and thus protects cells from free radical damage

Ex vivo expansion of CD3depleted cord blood-MNCs in the presence of bone marrow stromal cells; an appropriate strategy to provide functional NK cells applicable for cellular therapy

Directory of Open Access Journals (Sweden)

Ehteramolsadat Hosseini

2017-03-01

Full Text Available Considering umbilical cord blood (UCB as a rich source of hematopoietic stem cells, we introduced a cost-effective approach to expand CD3depleted UCB-MNCs into functional NK cells. CD3depleted UCB-MNCs were expanded in the presence or absence of a feeder [bone marrow stem cells (BMSCs or osteoblasts], with or without cytokines and their differentiation into NK cells was determined by flow cytometry. NK cell function was quantified by LAMP-1/CD107a expression, TNF-α/IFN-γ release, and LDH release/PI staining in targets. Higher expansion of NK cells was observed after two weeks in the presence of BMSCs and cytokines (104 ± 15 compared to osteoblasts and cytokines (84 ± 29, p < 0.05. On day 14, CD3depleted UCB-MNCs in the presence of BMSCs and cytokines showed lower expression of CD3, CD19, CD14, CD15 and CD69 as well as higher expression of CD2 and CD7, which were suggestive of cell differentiation into mature NK cell lineage. Strong cytotoxicity of expanded cells was also identified with higher LDH release and PI% in targets. Significant upregulation of LAMP-1 with decreased release of IFN-γ and TNF-α from effectors were observed. We demonstrate an effective expansion of UCB-NK cells that maintained their functional capabilities applicable for cellular therapies.

Recovery of deficient homologous recombination in Brca2-depleted mouse cells by wild-type Rad51 expression.

Science.gov (United States)

Lee, Shauna A; Roques, Céline; Magwood, Alissa C; Masson, Jean-Yves; Baker, Mark D

2009-02-01

The BRCA2 tumor suppressor is important in maintaining genomic stability. BRCA2 is proposed to control the availability, cellular localization and DNA binding activity of the central homologous recombination protein, RAD51, with loss of BRCA2 resulting in defective homologous recombination. Nevertheless, the roles of BRCA2 in regulating RAD51 and how other proteins implicated in RAD51 regulation, such as RAD52 and RAD54 function relative to BRCA2 is not known. In this study, we tested whether defective homologous recombination in Brca2-depleted mouse hybridoma cells could be rectified by expression of mouse Rad51 or the Rad51-interacting mouse proteins, Rad52 and Rad54. In the Brca2-depleted cells, defective homologous recombination can be restored by over-expression of wild-type mouse Rad51, but not mouse Rad52 or Rad54. Correction of the homologous recombination defect requires Rad51 ATPase activity. A sizeable fraction ( approximately 50%) of over-expressed wild-type Rad51 is nuclear localized. The restoration of homologous recombination in the presence of a low (i.e., non-functional) level of Brca2 by wild-type Rad51 over-expression is unexpected. We suggest that Rad51 may access the nuclear compartment in a Brca2-independent manner and when Rad51 is over-expressed, the normal requirement for Brca2 control over Rad51 function in homologous recombination is dispensable. Our studies support loss of Rad51 function as a critical underlying factor in the homologous recombination defect in the Brca2-depleted cells.

Lithium depletion and rotation in main-sequence stars

International Nuclear Information System (INIS)

Balachandran, S.

1990-01-01

Lithium abundances were measured in nearly 200 old disk-population F stars to examine the effects of rotational braking on the depletion of Li. The sample was selected to be slightly evolved off the main sequence so that the stars have completed all the Li depletion they will undergo on the main sequence. A large scatter in Li abundances in the late F stars is found, indicating that the Li depletion is not related to age and spectral type alone. Conventional depletion mechanisms like convective overshoot and microscopic diffusion are unable to explain Li depletion in F stars with thin convective envelopes and are doubly taxed to explain such a scatter. No correlation is found between Li abundance and the present projected rotational velocity and some of the most rapid rotators are undepleted, ruling out meridional circulation as the cause of Li depletion. There is a somewhat larger spread in Li abundances in the spun-down late F stars compared to the early F stars which should remain rotationally unaltered on the main sequence. 85 refs

HCMV spread and cell tropism are determined by distinct virus populations.

Directory of Open Access Journals (Sweden)

Laura Scrivano

Full Text Available Human cytomegalovirus (HCMV can infect many different cell types in vivo. Two gH/gL complexes are used for entry into cells. gH/gL/pUL(128,130,131A shows no selectivity for its host cell, whereas formation of a gH/gL/gO complex only restricts the tropism mainly to fibroblasts. Here, we describe that depending on the cell type in which virus replication takes place, virus carrying the gH/gL/pUL(128,130,131A complex is either released or retained cell-associated. We observed that virus spread in fibroblast cultures was predominantly supernatant-driven, whereas spread in endothelial cell (EC cultures was predominantly focal. This was due to properties of virus released from fibroblasts and EC. Fibroblasts released virus which could infect both fibroblasts and EC. In contrast, EC released virus which readily infected fibroblasts, but was barely able to infect EC. The EC infection capacities of virus released from fibroblasts or EC correlated with respectively high or low amounts of gH/gL/pUL(128,130,131A in virus particles. Moreover, we found that focal spread in EC cultures could be attributed to EC-tropic virus tightly associated with EC and not released into the supernatant. Preincubation of fibroblast-derived virus progeny with EC or beads coated with pUL131A-specific antibodies depleted the fraction that could infect EC, and left a fraction that could predominantly infect fibroblasts. These data strongly suggest that HCMV progeny is composed of distinct virus populations. EC specifically retain the EC-tropic population, whereas fibroblasts release EC-tropic and non EC-tropic virus. Our findings offer completely new views on how HCMV spread may be controlled by its host cells.

Transformation of human osteoblast cells to the tumorigenic phenotype by depleted uranium-uranyl chloride.

OpenAIRE

Miller, A C; Blakely, W F; Livengood, D; Whittaker, T; Xu, J; Ejnik, J W; Hamilton, M M; Parlette, E; John, T S; Gerstenberg, H M; Hsu, H

1998-01-01

Depleted uranium (DU) is a dense heavy metal used primarily in military applications. Although the health effects of occupational uranium exposure are well known, limited data exist regarding the long-term health effects of internalized DU in humans. We established an in vitro cellular model to study DU exposure. Microdosimetric assessment, determined using a Monte Carlo computer simulation based on measured intracellular and extracellular uranium levels, showed that few (0.0014%) cell nuclei...

Heme-Mediated Induction of CXCL10 and Depletion of CD34+ Progenitor Cells Is Toll-Like Receptor 4 Dependent.

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Carmen M Dickinson-Copeland

Full Text Available Plasmodium falciparum infection can cause microvascular dysfunction, cerebral encephalopathy and death if untreated. We have previously shown that high concentrations of free heme, and C-X-C motif chemokine 10 (CXCL10 in sera of malaria patients induce apoptosis in microvascular endothelial and neuronal cells contributing to vascular dysfunction, blood-brain barrier (BBB damage and mortality. Endothelial progenitor cells (EPC are microvascular endothelial cell precursors partly responsible for repair and regeneration of damaged BBB endothelium. Studies have shown that EPC's are depleted in severe malaria patients, but the mechanisms mediating this phenomenon are unknown. Toll-like receptors recognize a wide variety of pathogen-associated molecular patterns generated by pathogens such as bacteria and parasites. We tested the hypothesis that EPC depletion during malaria pathogenesis is a function of heme-induced apoptosis mediated by CXCL10 induction and toll-like receptor (TLR activation. Heme and CXCL10 concentrations in plasma obtained from malaria patients were elevated compared with non-malaria subjects. EPC numbers were significantly decreased in malaria patients (P < 0.02 and TLR4 expression was significantly elevated in vivo. These findings were confirmed in EPC precursors in vitro; where it was determined that heme-induced apoptosis and CXCL10 expression was TLR4-mediated. We conclude that increased serum heme mediates depletion of EPC during malaria pathogenesis.

Depletion of histone demethylase KDM2A enhanced the adipogenic and chondrogenic differentiation potentials of stem cells from apical papilla

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Dong, Rui [Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050 (China); Yao, Rui [Department of Pediatrics, Stomatological Hospital of Nankai University, Tianjin 300041 (China); Du, Juan [Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050 (China); Wang, Songlin [Molecular Laboratory for Gene Therapy and Tooth Regeneration, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050 (China); Department of Biochemistry and Molecular Biology, Capital Medical University School of Basic Medical Sciences, Beijing 100069 (China); Fan, Zhipeng, E-mail: zpfan@ccmu.edu.cn [Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050 (China)

2013-11-01

Mesenchymal stem cells (MSCs) are a reliable resource for tissue regeneration, but the molecular mechanism underlying directed differentiation remains unclear; this has restricted potential MSC applications. The histone demethylase, lysine (K)-specific demethylase 2A (KDM2A), is evolutionarily conserved and ubiquitously expressed members of the JmjC-domain-containing histone demethylase family. A previous study determined that KDM2A can regulate the cell proliferation and osteo/dentinogenic differentiation of MSCs. It is not known whether KDM2A is involved in the other cell lineages differentiation of MSCs. Here, we show that depletion of KDM2A by short hairpin RNAs can enhance adipogenic and chondrogenic differentiation potentials in human stem cells from apical papilla (SCAPs). We found that the stemness-related genes, SOX2, and the embryonic stem cell master transcription factor, NANOG were significantly increased after silence of KDM2A in SCAPs. Moreover, we found that knock-down of the KDM2A co-factor, BCOR also up-regulated the mRNA levels of SOX2 and NANOG. Furthermore, Chromatin immunoprecipitation assays demonstrate that silence of KDM2A increased the histone H3 Lysine 4 (H3K4) trimethylation in the SOX2 and NANOG locus and regulates its expression. In conclusion, our results suggested that depletion of KDM2A enhanced the adipogenic and chondrogenic differentiation potentials of SCAPs by up-regulated SOX2 and NANOG, BCOR also involved in this regulation as co-factor, and provided useful information to understand the molecular mechanism underlying directed differentiation in MSCs. - Highlights: • Depletion of KDM2A enhances adipogenic/chondrogenic differentiation in SCAPs. • Depletion of KDM2A enhances the differentiation of SCAPs by activate SOX2 and NANOG. • Silence of KDM2A increases histone H3 Lysine 4 trimethylation in SOX2 and NANOG. • BCOR is co-factor of KDM2A involved in the differentiation regulation.

Depletion of histone demethylase KDM2A enhanced the adipogenic and chondrogenic differentiation potentials of stem cells from apical papilla

International Nuclear Information System (INIS)

Dong, Rui; Yao, Rui; Du, Juan; Wang, Songlin; Fan, Zhipeng

2013-01-01

Mesenchymal stem cells (MSCs) are a reliable resource for tissue regeneration, but the molecular mechanism underlying directed differentiation remains unclear; this has restricted potential MSC applications. The histone demethylase, lysine (K)-specific demethylase 2A (KDM2A), is evolutionarily conserved and ubiquitously expressed members of the JmjC-domain-containing histone demethylase family. A previous study determined that KDM2A can regulate the cell proliferation and osteo/dentinogenic differentiation of MSCs. It is not known whether KDM2A is involved in the other cell lineages differentiation of MSCs. Here, we show that depletion of KDM2A by short hairpin RNAs can enhance adipogenic and chondrogenic differentiation potentials in human stem cells from apical papilla (SCAPs). We found that the stemness-related genes, SOX2, and the embryonic stem cell master transcription factor, NANOG were significantly increased after silence of KDM2A in SCAPs. Moreover, we found that knock-down of the KDM2A co-factor, BCOR also up-regulated the mRNA levels of SOX2 and NANOG. Furthermore, Chromatin immunoprecipitation assays demonstrate that silence of KDM2A increased the histone H3 Lysine 4 (H3K4) trimethylation in the SOX2 and NANOG locus and regulates its expression. In conclusion, our results suggested that depletion of KDM2A enhanced the adipogenic and chondrogenic differentiation potentials of SCAPs by up-regulated SOX2 and NANOG, BCOR also involved in this regulation as co-factor, and provided useful information to understand the molecular mechanism underlying directed differentiation in MSCs. - Highlights: • Depletion of KDM2A enhances adipogenic/chondrogenic differentiation in SCAPs. • Depletion of KDM2A enhances the differentiation of SCAPs by activate SOX2 and NANOG. • Silence of KDM2A increases histone H3 Lysine 4 trimethylation in SOX2 and NANOG. • BCOR is co-factor of KDM2A involved in the differentiation regulation

Menadione induces the formation of reactive oxygen species and depletion of GSH-mediated apoptosis and inhibits the FAK-mediated cell invasion.

Science.gov (United States)

Kim, Yun Jeong; Shin, Yong Kyoo; Sohn, Dong Suep; Lee, Chung Soo

2014-09-01

Menadione induces apoptosis in tumor cells. However, the mechanism of apoptosis in ovarian cancer cells exposed to menadione is not clear. In addition, it is unclear whether menadione-induced apoptosis is mediated by the depletion of glutathione (GSH) contents that is associated with the formation of reactive oxygen species. Furthermore, the effect of menadione on the invasion and migration of human epithelial ovarian cancer cells has not been studied. Therefore, we investigated the effects of menadione exposure on apoptosis, cell adhesion, and cell migration using the human epithelial ovarian carcinoma cell lines OVCAR-3 and SK-OV-3. The results suggest that menadione may induce apoptotic cell death in ovarian carcinoma cell lines by activating the mitochondrial pathway and the caspase-8- and Bid-dependent pathways. The apoptotic effect of menadione appears to be mediated by the formation of reactive oxygen species and the depletion of GSH. Menadione inhibited fetal-bovine-serum-induced cell adhesion and migration of OVCAR-3 cells, possibly through the suppression the focal adhesion kinase (FAK)-dependent activation of cytoskeletal-associated components. Therefore, menadione might be beneficial in the treatment of epithelial ovarian adenocarcinoma and combination therapy.

Induction of erythroid differentiation in human erythroleukemia cells by depletion of malic enzyme 2.

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Jian-Guo Ren

2010-09-01

Full Text Available Malic enzyme 2 (ME2 is a mitochondrial enzyme that catalyzes the conversion of malate to pyruvate and CO2 and uses NAD as a cofactor. Higher expression of this enzyme correlates with the degree of cell de-differentiation. We found that ME2 is expressed in K562 erythroleukemia cells, in which a number of agents have been found to induce differentiation either along the erythroid or the myeloid lineage. We found that knockdown of ME2 led to diminished proliferation of tumor cells and increased apoptosis in vitro. These findings were accompanied by differentiation of K562 cells along the erythroid lineage, as confirmed by staining for glycophorin A and hemoglobin production. ME2 knockdown also totally abolished growth of K562 cells in nude mice. Increased ROS levels, likely reflecting increased mitochondrial production, and a decreased NADPH/NADP+ ratio were noted but use of a free radical scavenger to decrease inhibition of ROS levels did not reverse the differentiation or apoptotic phenotype, suggesting that ROS production is not causally involved in the resultant phenotype. As might be expected, depletion of ME2 induced an increase in the NAD+/NADH ratio and ATP levels fell significantly. Inhibition of the malate-aspartate shuttle was insufficient to induce K562 differentiation. We also examined several intracellular signaling pathways and expression of transcription factors and intermediate filament proteins whose expression is known to be modulated during erythroid differentiation in K562 cells. We found that silencing of ME2 leads to phospho-ERK1/2 inhibition, phospho-AKT activation, increased GATA-1 expression and diminished vimentin expression. Metabolomic analysis, conducted to gain insight into intermediary metabolic pathways that ME2 knockdown might affect, showed that ME2 depletion resulted in high orotate levels, suggesting potential impairment of pyrimidine metabolism. Collectively our data point to ME2 as a potentially novel

Effects of glutathione depletion by buthionine sulfoximine on radiosensitization by oxygen and misonidazole in vitro

International Nuclear Information System (INIS)

Shrieve, D.C.; Denekamp, J.; Minchinton, A.I.

1985-01-01

Buthionine sulfoximine (BSO) has been used to deplete glutathione (GSH) in V79-379A cells in vitro, and the effect on the efficiency of oxygen and misonidazole (MISO) as radiosensitizers has been determined. Treatment with 50 or 500 μM BSO caused a rapid decline in GSH content to less than 5% of control values after 10 hr of exposure. Removal of BSO resulted in a rapid regeneration of GSH after 50 μM BSO, but little regeneration was observed over the subsequent 10-hr period after 500 μM. Cells irradiated in monolayer on glass had an oxygen enhancement ratio (OER) of 3.1. After 10-14 hr pretreatment with 50 μM BSO, washed cells were radiosensitized by GSH depletion at all oxygen tensions tested. The OER was reduced to 2.6, due to greater radiosensitization of hypoxic cells than aerated ones by GSH depletion. In similar experiments performed with MISO, an enhancement ratio of 2.0 could be achieved with 0.2 mM MISO in anoxic BSO-pretreated cells, compared to 2.7 mM MISO in non-BSO-treated cells. These apparent increases in radiosensitizer efficiency in GSH-depleted cells could be explained on the basis of radiosensitization of hypoxic cells by GSH depletion alone. These results are consistent with hypoxic cell radiosensitization by GSH depletion and by MISO or oxygen acting by separate mechanisms

Evolution of sociality in spiders leads to depleted genomic diversity at both population and species levels.

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Settepani, V; Schou, M F; Greve, M; Grinsted, L; Bechsgaard, J; Bilde, T

2017-08-01

Across several animal taxa, the evolution of sociality involves a suite of characteristics, a "social syndrome," that includes cooperative breeding, reproductive skew, primary female-biased sex ratio, and the transition from outcrossing to inbreeding mating system, factors that are expected to reduce effective population size (Ne). This social syndrome may be favoured by short-term benefits but come with long-term costs, because the reduction in Ne amplifies loss of genetic diversity by genetic drift, ultimately restricting the potential of populations to respond to environmental change. To investigate the consequences of this social life form on genetic diversity, we used a comparative RAD-sequencing approach to estimate genomewide diversity in spider species that differ in level of sociality, reproductive skew and mating system. We analysed multiple populations of three independent sister-species pairs of social inbreeding and subsocial outcrossing Stegodyphus spiders, and a subsocial outgroup. Heterozygosity and within-population diversity were sixfold to 10-fold lower in social compared to subsocial species, and demographic modelling revealed a tenfold reduction in Ne of social populations. Species-wide genetic diversity depends on population divergence and the viability of genetic lineages. Population genomic patterns were consistent with high lineage turnover, which homogenizes the genetic structure that builds up between inbreeding populations, ultimately depleting genetic diversity at the species level. Indeed, species-wide genetic diversity of social species was 5-8 times lower than that of subsocial species. The repeated evolution of species with this social syndrome is associated with severe loss of genomewide diversity, likely to limit their evolutionary potential. © 2017 John Wiley & Sons Ltd.

Born to be free? Assessing the viability of releasing captive-bred wobbegongs to restock depleted populations

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Kathryn Asha Lee

2015-04-01

Full Text Available Large predatory fishes, such as sharks, play an important functional role within marine ecosystems. Restocking of depleted populations has been extensively studied for commercially or recreationally important teleost fish species; however, it has, to the best of our knowledge, never been successfully attempted and assessed on sharks. We evaluated whether fifteen captive-bred wobbegongs (Orectolobus maculatus released into a small bay inhabited by wild sharks would survive and remain within a small ‘no-take’ marine reserve. The captive-bred sharks and twelve wild sharks were tagged with acoustic transmitters and their presence was monitored by an array of acoustic receivers. The detection rate of control tags was modelled against environmental variables to predict detection probabilities and account for days when environmental conditions hampered shark detections. The overall detection probability ranged from 28% to 38% and was most affected by wind direction. Wild wobbegongs showed clear seasonal patterns of attendance to the study site, with the highest probability of presence during the summer months. The captive-bred sharks did not display the same seasonal trend in occurrence. The age at which captive-bred sharks were released into the area affected residency periods. Four out of five adults remained in the area for up to three years post release, while all the juveniles permanently left the area within a year post-release. Three of the juveniles were detected on receivers up to 12 km from the study site. Therefore, if restocking of depleted populations of sharks is to be used as a conservation strategy, the age at which sharks are released must be considered.

Hybrid tandem solar cells with depleted-heterojunction quantum dot and polymer bulk heterojunction subcells

KAUST Repository

Kim, Taesoo

2015-10-01

We investigate hybrid tandem solar cells that rely on the combination of solution-processed depleted-heterojunction colloidal quantum dot (CQD) and bulk heterojunction polymer:fullerene subcells. The hybrid tandem solar cell is monolithically integrated and electrically connected in series with a suitable p-n recombination layer that includes metal oxides and a conjugated polyelectrolyte. We discuss the monolithic integration of the subcells, taking into account solvent interactions with underlayers and associated constraints on the tandem architecture, and show that an adequate device configuration consists of a low bandgap CQD bottom cell and a high bandgap polymer:fullerene top cell. Once we optimize the recombination layer and individual subcells, the hybrid tandem device reaches a VOC of 1.3V, approaching the sum of the individual subcell voltages. An impressive fill factor of 70% is achieved, further confirming that the subcells are efficiently connected via an appropriate recombination layer. © 2015.

Cholesterol depletion induces dynamic confinement of the G-protein coupled serotonin(1A) receptor in the plasma membrane of living cells.

Science.gov (United States)

Pucadyil, Thomas J; Chattopadhyay, Amitabha

2007-03-01

Cholesterol is an essential constituent of eukaryotic membranes and plays a crucial role in membrane organization, dynamics, function, and sorting. It is often found distributed non-randomly in domains or pools in biological and model membranes and is thought to contribute to a segregated distribution of membrane constituents. Signal transduction events mediated by seven transmembrane domain G-protein coupled receptors (GPCRs) are the primary means by which cells communicate with and respond to their external environment. We analyzed the role of cholesterol in the plasma membrane organization of the G-protein coupled serotonin(1A) receptor by fluorescence recovery after photobleaching (FRAP) measurements with varying bleach spot sizes. Our results show that lateral diffusion parameters of serotonin(1A) receptors in normal cells are consistent with models describing diffusion of molecules in a homogenous membrane. Interestingly, these characteristics are altered in cholesterol-depleted cells in a manner that is consistent with dynamic confinement of serotonin(1A) receptors in the plasma membrane. Importantly, analysis of ligand binding and downstream signaling of the serotonin(1A) receptor suggests that receptor function is affected in a significantly different manner when intact cells or isolated membranes are depleted of cholesterol. These results assume significance in the context of interpreting effects of cholesterol depletion on diffusion characteristics of membrane proteins in particular, and cholesterol-dependent cellular processes in general.

NK and NKT Cell Depletion Alters the Outcome of Experimental Pneumococcal Pneumonia: Relationship with Regulation of Interferon-γ Production

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Eirini Christaki

2015-01-01

Full Text Available Background. Natural killer (NK and natural killer T (NKT cells contribute to the innate host defense but their role in bacterial sepsis remains controversial. Methods. C57BL/6 mice were infected intratracheally with 5 × 105 cfu of Streptococcus pneumoniae. Animals were divided into sham group (Sham; pretreated with isotype control antibody (CON group; pretreated with anti-asialo GM1 antibody (NKd group; and pretreated with anti-CD1d monoclonal antibody (NKTd group before bacterial challenge. Serum and tissue samples were analyzed for bacterial load, cytokine levels, splenocyte apoptosis rates, and cell characteristics by flow cytometry. Splenocyte miRNA expression was also analyzed and survival was assessed. Results. NK cell depletion prolonged survival. Upon inhibition of NKT cell activation, spleen NK (CD3−/NK1.1+ cells increased compared to all other groups. Inhibition of NKT cell activation led to higher bacterial loads and increased levels of serum and splenocyte IFN-γ. Splenocyte miRNA analysis showed that miR-200c and miR-29a were downregulated, while miR-125a-5p was upregulated, in anti-CD1d treated animals. These changes were moderate after NK cell depletion. Conclusions. NK cells appear to contribute to mortality in pneumococcal pneumonia. Inhibition of NKT cell activation resulted in an increase in spleen NK (CD3−/NK1.1+ cells and a higher IFN-γ production, while altering splenocyte miRNA expression.

Phase II trial of the regulatory T cell-depleting agent, denileukin diftitox, in patients with unresectable stage IV melanoma

International Nuclear Information System (INIS)

Telang, Sucheta; Gragg, Hana; Clem, Brian F; McMasters, Kelly M; Miller, Donald M; Chesney, Jason; Rasku, Mary Ann; Clem, Amy L; Carter, Karen; Klarer, Alden C; Badger, Wesley R; Milam, Rebecca A; Rai, Shesh N; Pan, Jianmin

2011-01-01

We previously found that administration of an interleukin 2/diphtheria toxin conjugate (DAB/IL2; Denileukin Diftitox; ONTAK) to stage IV melanoma patients depleted CD4 + CD25 HI Foxp3 + regulatory T cells and expanded melanoma-specific CD8 + T cells. The goal of this study was to assess the clinical efficacy of DAB/IL2 in an expanded cohort of stage IV melanoma patients. In a single-center, phase II trial, DAB/IL2 (12 μg/kg; 4 daily doses; 21 day cycles) was administered to 60 unresectable stage IV melanoma patients and response rates were assessed using a combination of 2-[ 18 F]-fluoro-2-deoxy-glucose (FDG)-positron emission tomography (PET) and computed tomography (CT) imaging. After DAB/IL2 administration, 16.7% of the 60 patients had partial responses, 5% stable disease and 15% mixed responses. Importantly, 45.5% of the chemo/immuno-naïve sub-population (11/60 patients) experienced partial responses. One year survival was markedly higher in partial responders (80 ± 11.9%) relative to patients with progressive disease (23.7 ± 6.5%; p value < 0.001) and 40 ± 6.2% of the total DAB/IL2-treated population were alive at 1 year. These data support the development of multi-center, randomized trials of DAB/IL2 as a monotherapy and in combination with other immunotherapeutic agents for the treatment of stage IV melanoma. http://www.clinicaltrials.gov/ct2/show/NCT00299689

Depleted uranium

International Nuclear Information System (INIS)

Huffer, E.; Nifenecker, H.

2001-02-01

This document deals with the physical, chemical and radiological properties of the depleted uranium. What is the depleted uranium? Why do the military use depleted uranium and what are the risk for the health? (A.L.B.)

Alcohol depletes coenzyme-Q10 associated with increased TNF-alpha secretion to induce cytotoxicity in HepG2 cells

International Nuclear Information System (INIS)

Vidyashankar, Satyakumar; Nandakumar, Krishna S.; Patki, Pralhad S.

2012-01-01

Highlights: ► Ethanol induced cytotoxicity in HepG2 cells in absence of lipogenesis. ► Ethanol inhibited HMG-CoA reductase activity. ► Ethanol induced HMG-CoA reductase inhibition is due to decreased cell viability. ► Incubation with mevalonate could not increase the cholesterol. ► Cytotoxicity brought about by CoQ10 depletion and increased TNF-alpha. -- Abstract: Alcohol consumption has been implicated to cause severe hepatic steatosis which is mediated by alcohol dehydrogenase (ADH) activity and CYP 450 2E1 expression. In this context, the effect of ethanol was studied for its influence on lipogenesis in HepG2 cell which is deficient of ADH and does not express CYP 450 2E1. The results showed that ethanol at 100 mM concentration caused 40% cytotoxicity at 72 h as determined by MTT assay. The incorporation of labeled [2- 14 C] acetate into triacylglycerol and phospholipid was increased by 40% and 26% respectively upon 24 h incubation, whereas incorporation of labeled [2- 14 C] acetate into cholesterol was not significantly increased. Further, ethanol inhibited HMG-CoA reductase which is a rate-limiting enzyme in the cholesterol biosynthesis. It was observed that, HMG-CoA reductase inhibition was brought about by ethanol as a consequence of decreased cell viability, since incubation of HepG2 cells with mevalonate could not increase the cholesterol content and increase the cell viability. Addition of ethanol significantly increased TNF-alpha secretion and depleted mitochondrial coenzyme-Q 10 which is detrimental for cell viability. But vitamin E (10 mM) could partially restore coenzyme-Q 10 and glutathione content with decreased TNF-alpha secretion in ethanol treated cells. Further, lipid peroxidation, glutathione peroxidase and superoxide dismutase enzyme activities remained unaffected. Ethanol decreased glutathione content while, GSH/GSSG ratio was significantly higher compared to other groups showing cellular pro-oxidant and antioxidant balance remained

Ly6G-mediated depletion of neutrophils is dependent on macrophages.

Science.gov (United States)

Bruhn, Kevin W; Dekitani, Ken; Nielsen, Travis B; Pantapalangkoor, Paul; Spellberg, Brad

2016-01-01

Antibody-mediated depletion of neutrophils is commonly used to study neutropenia. However, the mechanisms by which antibodies deplete neutrophils have not been well defined. We noticed that mice deficient in complement and macrophages had blunted neutrophil depletion in response to anti-Ly6G monoclonal antibody (MAb) treatment. In vitro, exposure of murine neutrophils to anti-Ly6G MAb in the presence of plasma did not result in significant depletion of cells, either in the presence or absence of complement. In vivo, anti-Ly6G-mediated neutrophil depletion was abrogated following macrophage depletion, but not complement depletion, indicating a requirement for macrophages to induce neutropenia by this method. These results inform the use and limitations of anti-Ly6G antibody as an experimental tool for depleting neutrophils in various immunological settings.

In EXOG-depleted cardiomyocytes cell death is marked by a decreased mitochondrial reserve capacity of the electron transport chain

NARCIS (Netherlands)

Tigchelaar, Wardit; De Jong, Anne Margreet; van Gilst, Wiek H.; De Boer, Rudolf A.; Sillje, Herman H. W.

Depletion ofmitochondrial endo/exonuclease G-like (EXOG) in cultured neonatal cardiomyocytes stimulates mitochondrial oxygen consumption rate (OCR) and induces hypertrophy via reactive oxygen species (ROS). Here, we show that neurohormonal stress triggers cell death in endo/exonuclease

Follicles in gut-associated lymphoid tissues create preferential survival niches for follicular Th cells escaping Thy-1-specific depletion in mice.

Science.gov (United States)

Mihalj, Martina; Kellermayer, Zoltán; Balogh, Peter

2013-07-01

Although a substantial number of T cells may escape depletion following in vivo mAb treatment in patients undergoing immunosuppression, their specific tissue location and phenotypic characteristics in different peripheral lymphoid tissues have not been analyzed in detail. Here we investigated the survival of CD4(+) T cells immediately following anti-Thy-1 mAb treatment in mice. We found a preferential survival of CD4(+) T cells expressing Thy-1 antigen in the Peyer's patches (PP) and also in mesenteric lymph nodes (MLN), where the relative majority of the surviving CD4(+) T cells displayed CD44(high)/CD62L(-) phenotype corresponding to effector memory T-cell features. These CD4(+) T cells also expressed CXCR5 and PD-1 (programmed cell death-1) markers characteristic for follicular Th cells (TFH). We also demonstrate that the immediate survival of these cells does not involve proliferation and is independent of IL-7. Induction of germinal center formation in spleen enhanced while the dissolution of follicular architecture by lymphotoxin-β receptor antagonist treatment slightly reduced TFH survival. Our results thus raise the possibility that the follicles within PP and MLN may create natural support niches for the preferential survival of TFH cells of the memory phenotype, thus allowing their escape during T-cell depletion.

Mouse model of chromosome mosaicism reveals lineage-specific depletion of aneuploid cells and normal developmental potential.

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Bolton, Helen; Graham, Sarah J L; Van der Aa, Niels; Kumar, Parveen; Theunis, Koen; Fernandez Gallardo, Elia; Voet, Thierry; Zernicka-Goetz, Magdalena

2016-03-29

Most human pre-implantation embryos are mosaics of euploid and aneuploid cells. To determine the fate of aneuploid cells and the developmental potential of mosaic embryos, here we generate a mouse model of chromosome mosaicism. By treating embryos with a spindle assembly checkpoint inhibitor during the four- to eight-cell division, we efficiently generate aneuploid cells, resulting in embryo death during peri-implantation development. Live-embryo imaging and single-cell tracking in chimeric embryos, containing aneuploid and euploid cells, reveal that the fate of aneuploid cells depends on lineage: aneuploid cells in the fetal lineage are eliminated by apoptosis, whereas those in the placental lineage show severe proliferative defects. Overall, the proportion of aneuploid cells is progressively depleted from the blastocyst stage onwards. Finally, we show that mosaic embryos have full developmental potential, provided they contain sufficient euploid cells, a finding of significance for the assessment of embryo vitality in the clinic.

Compared studies of natural and artificial deuterium depleted water

International Nuclear Information System (INIS)

Butnaru, Gallia; Mihacea, Sorina; Sirbovan, Alina; Butnariu, H.; Titescu, Gh.

2001-01-01

The biological influence of the deuterium on animals was studied insensitively in the last years. When animal cell cultures were analyzed it turned out an inhibition of the development, due to the reduced deuterium concentration. In the in vivo experiments a decreasing of the number of tumoral cells was pointed out when performing the depleted water treatment. It is obvious that the presence of deuterium in water is necessary for the development, especially for the tumoral cell proliferation. The aim of this work was to establish influence of the natural and artificial deuterium depleted water on the vegetal organisms development. For this purpose, the developmental stages of Lactuca sativa L. growth were followed. The experimental data were compared with the data obtained with distilled water. The birch, wine sap and some fruit juices are considered 'natural depleted' water sources because their deuterium content is smaller in comparison to natural water (D 2 =150 ppm). The effect of artificial deuterium depleted water (29 ppm D 2 ) was analyzed in comparison to three types of wine saps, which also have a reduced deuterium concentration (125-130 ppm D 2 ). If the deuterium depleted water was used, the germination percent and the root and shoot length were higher compared to control in the first stages. In wine sap it had a negative effect on germination and development. After three days the plants were transferred to soil and their development was followed. The foliage area was larger for all of the experimental variants compared to control. The differences were without significance when deuterium depleted water was tested but they were high and very significant in case of wine sap. The experiment pointed out a stimulative effect of the artificial deuterium depleted water. In case of wine sap the effect was negative when the contact was direct, but the growth was stimulated after the stress cessation. The first ontogenetic stages were represented by direct action

Low ATM protein expression and depletion of p53 correlates with olaparib sensitivity in gastric cancer cell lines

Science.gov (United States)

Kubota, Eiji; Williamson, Christopher T; Ye, Ruiqiong; Elegbede, Anifat; Peterson, Lars; Lees-Miller, Susan P; Bebb, D Gwyn

2014-01-01

Small-molecule inhibitors of poly (ADP-ribose) polymerase (PARP) have shown considerable promise in the treatment of homologous recombination (HR)-defective tumors, such as BRCA1- and BRCA2-deficient breast and ovarian cancers. We previously reported that mantle cell lymphoma cells with deficiency in ataxia telangiectasia mutated (ATM) are sensitive to PARP-1 inhibitors in vitro and in vivo. Here, we report that PARP inhibitors can potentially target ATM deficiency arising in a solid malignancy. We show that ATM protein expression varies between gastric cancer cell lines, with NUGC4 having significantly reduced protein levels. Significant correlation was found between ATM protein expression and sensitivity to the PARP inhibitor olaparib, with NUGC4 being the most sensitive. Moreover, reducing ATM kinase activity using a small-molecule inhibitor (KU55933) or shRNA-mediated depletion of ATM protein enhanced olaparib sensitivity in gastric cancer cell lines with depletion or inactivation of p53. Our results demonstrate that ATM is a potential predictive biomarker for PARP-1 inhibitor activity in gastric cancer harboring disruption of p53, and that combined inhibition of ATM and PARP-1 is a rational strategy for expanding the utility of PARP-1 inhibitors to gastric cancer with p53 disruption. PMID:24841718

Acyclovir-resistant herpes simplex virus 1 infection early after allogeneic hematopoietic stem cell transplantation with T-cell depletion.

Science.gov (United States)

Akahoshi, Yu; Kanda, Junya; Ohno, Ayumu; Komiya, Yusuke; Gomyo, Ayumi; Hayakawa, Jin; Harada, Naonori; Kameda, Kazuaki; Ugai, Tomotaka; Wada, Hidenori; Ishihara, Yuko; Kawamura, Koji; Sakamoto, Kana; Sato, Miki; Terasako-Saito, Kiriko; Kimura, Shun-Ichi; Kikuchi, Misato; Nakasone, Hideki; Kako, Shinichi; Shiraki, Kimiyasu; Kanda, Yoshinobu

2017-07-01

We previously reported that oral low-dose acyclovir (200 mg/day) for the prevention of herpes simplex virus (HSV) infections after allogenic hematopoietic stem cell transplantation (HSCT) is effective without the emergence of acyclovir-resistant HSV infections. However, HSV infections are of significant concern because the number of allogeneic HSCT with T-cell depletion, which is a risk factor of the emergence of drug-resistant HSV infections, has been increasing. We experienced a 25-year-old female who received allogenic HSCT from an unrelated donor with 1-antigen mismatch using anti-thymocyte globulin. Despite acyclovir prophylaxis (200 mg/day), she developed the right palatal ulcer that was positive for HSV-1 specific antigen by fluorescent antibody on day 20 and developed new hypoglossal and tongue ulcers on day 33. Replacement of acyclovir with foscarnet improved her ulcers. We isolated 2 acyclovir-resistant and foscarnet-sensitive strains from the right palatal and hypoglossal ulcers, which had the same frame shift mutation in the thymidine kinase genes. The rate of proliferation of the isolate from the hypoglossal ulcer was faster than that from the right palatal ulcer in the plaque reduction assay. HSV strains that acquired acyclovir-resistant mutations at the right palatal ulcer with larger plaque might spread to the hypoglossal ulcer as the secondary site of infection because of better growth property. Second-line antiviral agents should be considered when we suspect treatment failure of HSV infection, especially in HSCT with T-cell depletion. Further studies are required whether low-dose acyclovir prophylaxis leads to the emergence of virological resistance. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Effect of selective T cell depletion of host and/or donor bone marrow on lymphopoietic repopulation, tolerance, and graft-vs-host disease in mixed allogeneic chimeras (B10 + B10.D2----B10)

International Nuclear Information System (INIS)

Ildstad, S.T.; Wren, S.M.; Bluestone, J.A.; Barbieri, S.A.; Stephany, D.; Sachs, D.H.

1986-01-01

Reconstitution of lethally irradiated mice with a mixture of T cell-depleted syngeneic plus T cell-depleted allogeneic bone marrow (B10 + B10.D2----B10) leads to the induction of mixed lymphopoietic chimerism, excellent survivals, specific in vivo transplantation tolerance to subsequent donor strain skin grafts, and specific in vitro unresponsiveness to allogeneic donor lymphoid elements as assessed by mixed lymphocyte reaction (MLR) proliferative and cell-mediated lympholysis (CML) cytotoxicity assays. When B10 recipient mice received mixed marrow inocula in which the syngeneic component had not been T cell depleted, whether or not the allogeneic donor marrow was treated, they repopulated exclusively with host-type cells, promptly rejected donor-type skin allografts, and were reactive in vitro to the allogeneic donor by CML and MLR assays. In contrast, T cell depletion of the syngeneic component of the mixed marrow inocula resulted in specific acceptance of allogeneic donor strain skin grafts. Such animals were specifically unreactive to allogeneic donor lymphoid elements in vitro by CML and MLR, but were reactive to third party. When both the syngeneic and allogeneic marrow were T cell depleted, variable percentages of host- and donor-type lymphoid elements were detected in the mixed reconstituted host. When only the syngeneic bone marrow was T cell depleted, animals repopulated exclusively with donor-type cells. Although these animals had detectable in vitro anti-host (B10) reactivity by CML and MLR and reconstituted as fully allogeneic chimeras, they exhibited excellent survival and had no in vivo evidence for graft-vs-host disease. Experiments in which untreated donor spleen cells were added to the inocula in this last group suggest that the presence of T cell-depleted syngeneic bone marrow cells diminishes graft-vs-host disease and the mortality from it

Development of the point-depletion code DEPTH

International Nuclear Information System (INIS)

She, Ding; Wang, Kan; Yu, Ganglin

2013-01-01

Highlights: ► The DEPTH code has been developed for the large-scale depletion system. ► DEPTH uses the data library which is convenient to couple with MC codes. ► TTA and matrix exponential methods are implemented and compared. ► DEPTH is able to calculate integral quantities based on the matrix inverse. ► Code-to-code comparisons prove the accuracy and efficiency of DEPTH. -- Abstract: The burnup analysis is an important aspect in reactor physics, which is generally done by coupling of transport calculations and point-depletion calculations. DEPTH is a newly-developed point-depletion code of handling large burnup depletion systems and detailed depletion chains. For better coupling with Monte Carlo transport codes, DEPTH uses data libraries based on the combination of ORIGEN-2 and ORIGEN-S and allows users to assign problem-dependent libraries for each depletion step. DEPTH implements various algorithms of treating the stiff depletion systems, including the Transmutation trajectory analysis (TTA), the Chebyshev Rational Approximation Method (CRAM), the Quadrature-based Rational Approximation Method (QRAM) and the Laguerre Polynomial Approximation Method (LPAM). Three different modes are supported by DEPTH to execute the decay, constant flux and constant power calculations. In addition to obtaining the instantaneous quantities of the radioactivity, decay heats and reaction rates, DEPTH is able to calculate the integral quantities by a time-integrated solver. Through calculations compared with ORIGEN-2, the validity of DEPTH in point-depletion calculations is proved. The accuracy and efficiency of depletion algorithms are also discussed. In addition, an actual pin-cell burnup case is calculated to illustrate the DEPTH code performance in coupling with the RMC Monte Carlo code

Depletion of primordial germ cells (PGCs) by X-irradiation to extraembryonic region of chicken embryos and expression of xenotransplanted quail PGCs

International Nuclear Information System (INIS)

Atsumi, Y.; Yazawa, S.; Usui, F.; Nakamura, Y.; Yamamoto, Y.; Tagami, T.; Hiramatsu, K.; Kagami, H.; Ono, T.

2009-01-01

The generation of germline chimeras by the transfer of primordial germ cells (PGCs) requires incorporation of the PGCs of the donor into the gonadal tissue of the recipient embryo. We investigated the utility of soft x-irradiation with application of a lead (12 x 3 x 0.25 mm, - 0.1 g) shield to the embryo proper for the production of chicken-quail germline chimeras. Chicken embryos shielded during irradiation for 120s (- 7.2 Gy) at stages 13 to 17 showed a hatchability of 35% (106/301), whereas the hatchability of unshielded embryos was 26% (27/105). The relative population of gonadal PGCs at stage 30 for embryos irradiated at stage 13 with or without shielding was 13 and 5%, respectively, of the value for nonirradiated controls. Chicken embryos irradiated at stages 13 or 14 with or without shielding and transfused with quail embryonic blood containing PGCs each exhibited - 130 relative population of donor PGCs in the left gonad at stage 30. Xenotransplanted hatchlings exhibited donor-derived PGCs as detected by Southern hybridization and PCR. Exposure of chicken embryos to - 7.2 Gy of x-radiation at stage 13 with the application of a lead shield to the embryo proper is thus a feasible approach to depletion of endogenous germ cells and the production of chicken-quail germline chimeras

Groundwater Depletion Embedded in International Food Trade

Science.gov (United States)

Dalin, Carole; Wada, Yoshihide; Kastner, Thomas; Puma, Michael J.

2017-01-01

Recent hydrological modeling and Earth observations have located and quantified alarming rates of groundwater depletion worldwide. This depletion is primarily due to water withdrawals for irrigation, but its connection with the main driver of irrigation, global food consumption, has not yet been explored. Here we show that approximately eleven per cent of non-renewable groundwater use for irrigation is embedded in international food trade, of which two-thirds are exported by Pakistan, the USA and India alone. Our quantification of groundwater depletion embedded in the world's food trade is based on a combination of global, crop-specific estimates of non-renewable groundwater abstraction and international food trade data. A vast majority of the world's population lives in countries sourcing nearly all their staple crop imports from partners who deplete groundwater to produce these crops, highlighting risks for global food and water security. Some countries, such as the USA, Mexico, Iran and China, are particularly exposed to these risks because they both produce and import food irrigated from rapidly depleting aquifers. Our results could help to improve the sustainability of global food production and groundwater resource management by identifying priority regions and agricultural products at risk as well as the end consumers of these products.

Groundwater depletion embedded in international food trade

Science.gov (United States)

Dalin, Carole; Wada, Yoshihide; Kastner, Thomas; Puma, Michael J.

2017-03-01

Recent hydrological modelling and Earth observations have located and quantified alarming rates of groundwater depletion worldwide. This depletion is primarily due to water withdrawals for irrigation, but its connection with the main driver of irrigation, global food consumption, has not yet been explored. Here we show that approximately eleven per cent of non-renewable groundwater use for irrigation is embedded in international food trade, of which two-thirds are exported by Pakistan, the USA and India alone. Our quantification of groundwater depletion embedded in the world’s food trade is based on a combination of global, crop-specific estimates of non-renewable groundwater abstraction and international food trade data. A vast majority of the world’s population lives in countries sourcing nearly all their staple crop imports from partners who deplete groundwater to produce these crops, highlighting risks for global food and water security. Some countries, such as the USA, Mexico, Iran and China, are particularly exposed to these risks because they both produce and import food irrigated from rapidly depleting aquifers. Our results could help to improve the sustainability of global food production and groundwater resource management by identifying priority regions and agricultural products at risk as well as the end consumers of these products.

Emergence of cytotoxic resistance in cancer cell populations: Single-cell mechanisms and population-level consequences

International Nuclear Information System (INIS)

Lorenzi, Tommaso; Chisholm, Rebecca H.; Lorz, Alexander; Neves de Almeida, Luís; Clairambault, Jean; Larsen, Annette K.; Escargueil, Alexandre

2016-01-01

We formulate an individual-based model and a population model of phenotypic evolution, under cytotoxic drugs, in a cancer cell population structured by the expression levels of survival-potential and proliferation-potential. We apply these models to a recently studied experimental system. Our results suggest that mechanisms based on fundamental laws of biology can reversibly push an actively-proliferating, and drug-sensitive, cell population to transition into a weakly-proliferative and drug-tolerant state, which will eventually facilitate the emergence of more potent, proliferating and drug-tolerant cells.

Emergence of cytotoxic resistance in cancer cell populations: Single-cell mechanisms and population-level consequences

Energy Technology Data Exchange (ETDEWEB)

Lorenzi, Tommaso [Centre de Mathématiques et de Leurs Applications, ENS Cachan, CNRS, Cachan 94230 Cedex, France & INRIA-Paris-Rocquencourt, MAMBA Team, Domaine de Voluceau, BP105, 78153 Le Chesnay Cedex (France); Chisholm, Rebecca H. [School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney NSW 2052 (Australia); Lorz, Alexander; Neves de Almeida, Luís; Clairambault, Jean [Sorbonne Universités, UPMC Univ Paris 06, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris (France); CNRS, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris (France); INRIA-Paris-Rocquencourt, MAMBA Team, Domaine de Voluceau, BP105, 78153 Le Chesnay Cedex (France); Larsen, Annette K.; Escargueil, Alexandre [Sorbonne Universités, UPMC Univ Paris 06, F-75005, Paris (France); INSERM, UMR-S 938, Laboratory of “Cancer Biology and Therapeutics”, F-75012, Paris (France)

2016-06-08

We formulate an individual-based model and a population model of phenotypic evolution, under cytotoxic drugs, in a cancer cell population structured by the expression levels of survival-potential and proliferation-potential. We apply these models to a recently studied experimental system. Our results suggest that mechanisms based on fundamental laws of biology can reversibly push an actively-proliferating, and drug-sensitive, cell population to transition into a weakly-proliferative and drug-tolerant state, which will eventually facilitate the emergence of more potent, proliferating and drug-tolerant cells.

Analysis of Vaginal Cell Populations during Experimental Vaginal Candidiasis

OpenAIRE

Fidel, Paul L.; Luo, Wei; Steele, Chad; Chabain, Joseph; Baker, Marc; Wormley, Floyd

1999-01-01

Studies with an estrogen-dependent murine model of vaginal candidiasis suggest that local cell-mediated immunity (CMI) is more important than systemic CMI for protection against vaginitis. The present study, however, showed that, compared to uninfected mice, little to no change in the percentage or types of vaginal T cells occurred during a primary vaginal infection or during a secondary vaginal infection where partial protection was observed. Furthermore, depletion of polymorphonuclear leuko...

Significant Depletion of CD4+ T Cells Occurs in the Oral Mucosa during Simian Immunodeficiency Virus Infection with the Infected CD4+ T Cell Reservoir Continuing to Persist in the Oral Mucosa during Antiretroviral Therapy

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Jeffy George

2015-01-01

Full Text Available Human and simian immunodeficiency virus (HIV and SIV infections are characterized by manifestation of numerous opportunistic infections and inflammatory conditions in the oral mucosa. The loss of CD4+ T cells that play a critical role in maintaining mucosal immunity likely contributes to this process. Here we show that CD4+ T cells constitute a minor population of T cells in the oral mucosa and display a predominantly central memory phenotype mirroring other mucosal sites such as the rectal mucosa. Chronic SIV infection was associated with a near total depletion of CD4+ T cells in the oral mucosa that appear to repopulate during antiretroviral therapy (ART. Repopulating CD4+ T cells harbored a large fraction of Th17 cells suggesting that ART potentially reconstitutes oral mucosal immunity. However, a minor fraction of repopulating CD4+ T cells harbored SIV DNA suggesting that the viral reservoir continues to persist in the oral mucosa during ART. Therapeutic approaches aimed at obtaining sustainable CD4+ T cell repopulation in combination with strategies that can eradicate the latent viral reservoir in the oral mucosa are essential for better oral health and long-term outcome in HIV infected patients.

Treg depletion inhibits efficacy of cancer immunotherapy: implications for clinical trials.

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James F Curtin

2008-04-01

Full Text Available Regulatory T lymphocytes (Treg infiltrate human glioblastoma (GBM; are involved in tumor progression and correlate with tumor grade. Transient elimination of Tregs using CD25 depleting antibodies (PC61 has been found to mediate GBM regression in preclinical models of brain tumors. Clinical trials that combine Treg depletion with tumor vaccination are underway to determine whether transient Treg depletion can enhance anti-tumor immune responses and improve long term survival in cancer patients.Using a syngeneic intracrabial glioblastoma (GBM mouse model we show that systemic depletion of Tregs 15 days after tumor implantation using PC61 resulted in a decrease in Tregs present in tumors, draining lymph nodes and spleen and improved long-term survival (50% of mice survived >150 days. No improvement in survival was observed when Tregs were depleted 24 days after tumor implantation, suggesting that tumor burden is an important factor for determining efficacy of Treg depletion in clinical trials. In a T cell dependent model of brain tumor regression elicited by intratumoral delivery of adenoviral vectors (Ad expressing Fms-like Tyrosine Kinase 3 ligand (Flt3L and Herpes Simplex Type 1-Thymidine Kinase (TK with ganciclovir (GCV, we demonstrate that administration of PC61 24 days after tumor implantation (7 days after treatment inhibited T cell dependent tumor regression and long term survival. Further, depletion with PC61 completely inhibited clonal expansion of tumor antigen-specific T lymphocytes in response to the treatment.Our data demonstrate for the first time, that although Treg depletion inhibits the progression/eliminates GBM tumors, its efficacy is dependent on tumor burden. We conclude that this approach will be useful in a setting of minimal residual disease. Further, we also demonstrate that Treg depletion, using PC61 in combination with immunotherapy, inhibits clonal expansion of tumor antigen-specific T cells, suggesting that new, more

PDGFRα depletion attenuates glioblastoma stem cells features by modulation of STAT3, RB1 and multiple oncogenic signals.

Science.gov (United States)

Cenciarelli, Carlo; Marei, Hany E; Felsani, Armando; Casalbore, Patrizia; Sica, Gigliola; Puglisi, Maria Ausiliatrice; Cameron, Angus J M; Olivi, Alessandro; Mangiola, Annunziato

2016-08-16

Platelet derived growth factor receptors (PDGFRs) play an important role in tumor pathogenesis, and they are frequently overexpressed in glioblastoma (GBM). Earlier we have shown a higher protein expression of PDGFR isoforms (α and β) in peritumoral-tissue derived cancer stem cells (p-CSC) than in tumor core (c-CSC) of several GBM affected patients. In the current study, in order to assess the activity of PDGFRα/PDGF-AA signaling axis, we performed time course experiments to monitor the effects of exogenous PDGF-AA on the expression of downstream target genes in c-CSC vs p-CSC. Interestingly, in p-CSC we detected the upregulation of Y705-phosphorylated Stat3, concurrent with a decrement of Rb1 protein in its active state, within minutes of PDGF-AA addition. This finding prompted us to elucidate the role of PDGFRα in self-renewal, invasion and differentiation in p-CSC by using short hairpin RNA depletion of PDGFRα expression. Notably, in PDGFRα-depleted cells, protein analysis revealed attenuation of stemness-related and glial markers expression, alongside early activation of the neuronal marker MAP2a/b that correlated with the induction of tumor suppressor Rb1. The in vitro reduction of the invasive capacity of PDGFRα-depleted CSC as compared to parental cells correlated with the downmodulation of markers of epithelial-mesenchymal transition phenotype and angiogenesis. Surprisingly, we observed the induction of anti-apoptotic proteins and compensatory oncogenic signals such as EDN1, EDNRB, PRKCB1, PDGF-C and PDGF-D. To conclude, we hypothesize that the newly discovered PDGFRα/Stat3/Rb1 regulatory axis might represent a potential therapeutic target for GBM treatment.

The impact of chronic GVHD on survival of Patients with acute myeloid leukemia after non-T-cell depleted HLA-identical sibling peripheral blood stem cells transplantation

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farhad Shahsavar

2012-06-01

Conclusion: These data indicate that the occurrence of cGVHD is an important predictor of outcome of non-T-cell depleted HLA-identical sibling allogeneic PBSCT, in those AML patients who develope cGVHD have a high chance of survival.

Differential Membrane Dipolar Orientation Induced by Acute and Chronic Cholesterol Depletion.

Science.gov (United States)

Sarkar, Parijat; Chakraborty, Hirak; Chattopadhyay, Amitabha

2017-06-30

Cholesterol plays a crucial role in cell membrane organization, dynamics and function. Depletion of cholesterol represents a popular approach to explore cholesterol-sensitivity of membrane proteins. An emerging body of literature shows that the consequence of membrane cholesterol depletion often depends on the actual process (acute or chronic), although the molecular mechanism underlying the difference is not clear. Acute depletion, using cyclodextrin-type carriers, is faster relative to chronic depletion, in which inhibitors of cholesterol biosynthesis are used. With the overall goal of addressing molecular differences underlying these processes, we monitored membrane dipole potential under conditions of acute and chronic cholesterol depletion in CHO-K1 cells, using a voltage-sensitive fluorescent dye in dual wavelength ratiometric mode. Our results show that the observed membrane dipole potential exhibits difference under acute and chronic cholesterol depletion conditions, even when cholesterol content was identical. To the best of our knowledge, these results provide, for the first time, molecular insight highlighting differences in dipolar reorganization in these processes. A comprehensive understanding of processes in which membrane cholesterol gets modulated would provide novel insight in its interaction with membrane proteins and receptors, thereby allowing us to understand the role of cholesterol in cellular physiology associated with health and disease.

The dinoflagellate Lingulodinium polyedrum responds to N depletion by a polarized deposition of starch and lipid bodies.

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Steve Dagenais Bellefeuille

Full Text Available Dinoflagellates are important contributors to the marine phytoplankton and global carbon fixation, but are also infamous for their ability to form the spectacular harmful algal blooms called red tides. While blooms are often associated with high available nitrogen, there are instances where they are observed in oligotrophic environments. In order to maintain their massive population in conditions of nitrogen limitation, dinoflagellates must have evolved efficient adaptive mechanisms. Here we report the physiological responses to nitrogen deprivation in Lingulodinium polyedrum. We find that this species reacts to nitrogen stress, as do most plants and microalgae, by stopping cell growth and diminishing levels of internal nitrogen, in particular in the form of protein and chlorophyll. Photosynthesis is maintained at high levels for roughly a week following nitrate depletion, resulting in accumulated photosynthetic products in the form of starch. During the second week, photosynthesis rates decrease due to a reduction in the number of chloroplasts and the accumulation of neutral lipid droplets. Surprisingly, the starch granules and lipid droplets are seen to accumulate at opposite poles of the cell. Lastly, we observe that cells acclimated to nitrogen-depleted conditions resume normal growth after addition of inorganic nitrogen, but are able to maintain high cell densities far longer than cells grown continuously in nitrogen-replete conditions.

Outcome of children with acute leukemia given HLA-haploidentical HSCT after αβ T-cell and B-cell depletion.

Science.gov (United States)

Locatelli, Franco; Merli, Pietro; Pagliara, Daria; Li Pira, Giuseppina; Falco, Michela; Pende, Daniela; Rondelli, Roberto; Lucarelli, Barbarella; Brescia, Letizia Pomponia; Masetti, Riccardo; Milano, Giuseppe Maria; Bertaina, Valentina; Algeri, Mattia; Pinto, Rita Maria; Strocchio, Luisa; Meazza, Raffaella; Grapulin, Lavinia; Handgretinger, Rupert; Moretta, Alessandro; Bertaina, Alice; Moretta, Lorenzo

2017-08-03

Allogeneic hematopoietic stem cell transplantation (HSCT) from an HLA-haploidentical relative (haplo-HSCT) is a suitable option for children with acute leukemia (AL) either relapsed or at high-risk of treatment failure. We developed a novel method of graft manipulation based on negative depletion of αβ T and B cells and conducted a prospective trial evaluating the outcome of children with AL transplanted with this approach. Eighty AL children, transplanted between September 2011 and September 2014, were enrolled in the trial. All children were given a fully myeloablative preparative regimen. Anti-T-lymphocyte globulin from day -5 to -3 was used for preventing graft rejection and graft-versus-host disease (GVHD); no patient received any posttransplantation GVHD prophylaxis. Two children experienced primary graft failure. The cumulative incidence of skin-only, grade 1-2 acute GVHD was 30%; no patient developed extensive chronic GVHD. Four patients died, the cumulative incidence of nonrelapse mortality being 5%, whereas 19 relapsed, resulting in a 24% cumulative incidence of relapse. With a median follow-up of 46 months for surviving patients, the 5-year probability of chronic GVHD-free, relapse-free survival (GRFS) is 71%. Total body irradiation-containing preparative regimen was the only variable favorably influencing relapse incidence and GRFS. The outcomes of these 80 patients are comparable to those of 41 and 51 children given transplantation from an HLA-identical sibling or a 10/10 allelic-matched unrelated donor in the same period. These data indicate that haplo-HSCT after αβ T- and B-cell depletion represents a competitive alternative for children with AL in need of urgent allograft. This trial was registered at www.clinicaltrials.gov as #NCT01810120. © 2017 by The American Society of Hematology.

Theophylline prevents NAD+ depletion via PARP-1 inhibition in human pulmonary epithelial cells

International Nuclear Information System (INIS)

Moonen, Harald J.J.; Geraets, Liesbeth; Vaarhorst, Anika; Bast, Aalt; Wouters, Emiel F.M.; Hageman, Geja J.

2005-01-01

Oxidative DNA damage, as occurs during exacerbations in chronic obstructive pulmonary disease (COPD), highly activates the nuclear enzyme poly(ADP-ribose)polymerase-1 (PARP-1). This can lead to cellular depletion of its substrate NAD + , resulting in an energy crisis and ultimately in cell death. Inhibition of PARP-1 results in preservation of the intracellular NAD + pool, and of NAD + -dependent cellular processes. In this study, PARP-1 activation by hydrogen peroxide decreased intracellular NAD + levels in human pulmonary epithelial cells, which was found to be prevented in a dose-dependent manner by theophylline, a widely used compound in the treatment of COPD. This enzyme inhibition by theophylline was confirmed in an ELISA using purified human PARP-1 and was found to be competitive by nature. These findings provide new mechanistic insights into the therapeutic effect of theophylline in oxidative stress-induced lung pathologies

WT1 Is Necessary for the Proliferation and Migration of Cells of Renin Lineage Following Kidney Podocyte Depletion

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Natalya V. Kaverina

2017-10-01

Full Text Available Wilms' tumor suppressor 1 (WT1 plays an important role in cell proliferation and mesenchymal-epithelial balance in normal development and disease. Here, we show that following podocyte depletion in three experimental models, and in patients with focal segmental glomerulosclerosis (FSGS and membranous nephropathy, WT1 increased significantly in cells of renin lineage (CoRL. In an animal model of FSGS in RenWt1fl/fl reporter mice with inducible deletion of WT1 in CoRL, CoRL proliferation and migration to the glomerulus was reduced, and glomerular disease was worse compared with wild-type mice. To become podocytes, CoRL undergo mesenchymal-to-epithelial transformation (MET, typified by reduced staining for mesenchymal markers (MYH11, SM22, αSMA and de novo expression of epithelial markers (E-cadherin and cytokeratin18. Evidence for changes in MET markers was barely detected in RenWt1fl/fl mice. Our results show that following podocyte depletion, WT1 plays essential roles in CoRL proliferation and migration toward an adult podocyte fate.

Depletion of the type 1 IGF receptor delays repair of radiation-induced DNA double strand breaks

International Nuclear Information System (INIS)

Turney, Benjamin W.; Kerr, Martin; Chitnis, Meenali M.; Lodhia, Kunal; Wang, Yong; Riedemann, Johann; Rochester, Mark; Protheroe, Andrew S.; Brewster, Simon F.; Macaulay, Valentine M.

2012-01-01

Background and purpose: IGF-1R depletion sensitizes prostate cancer cells to ionizing radiation and DNA-damaging cytotoxic drugs. This study investigated the hypothesis that IGF-1R regulates DNA double strand break (DSB) repair. Methods: We tested effects of IGF-1R siRNA transfection on the repair of radiation-induced DSBs by immunoblotting and immunofluorescence for γH2AX, and pulsed-field gel electrophoresis. Homologous recombination (HR) was quantified by reporter assays, and cell cycle distribution by flow cytometry. Results: We confirmed that IGF-1R depletion sensitized DU145 and PC3 prostate cancer cells to ionizing radiation. DU145 control transfectants resolved radiation-induced DSBs within 24 h, while IGF-1R depleted cells contained 30–40% unrepaired breaks at 24 h. IGF-1R depletion induced significant reduction in DSB repair by HR, although the magnitude of the repair defect suggests additional contributory factors. Radiation-induced G2-M arrest was attenuated by IGF-1R depletion, potentially suppressing cell cycle-dependent processes required for HR. In contrast, IGF-1R depletion induced only minor radiosensitization in LNCaP cells, and did not influence repair. Cell cycle profiles were similar to DU145, so were unlikely to account for differences in repair responses. Conclusions: These data indicate a role for IGF-1R in DSB repair, at least in part via HR, and support use of IGF-1R inhibitors with DNA damaging cancer treatments.

Depletion of the type 1 IGF receptor delays repair of radiation-induced DNA double strand breaks.

Science.gov (United States)

Turney, Benjamin W; Kerr, Martin; Chitnis, Meenali M; Lodhia, Kunal; Wang, Yong; Riedemann, Johann; Rochester, Mark; Protheroe, Andrew S; Brewster, Simon F; Macaulay, Valentine M

2012-06-01

IGF-1R depletion sensitizes prostate cancer cells to ionizing radiation and DNA-damaging cytotoxic drugs. This study investigated the hypothesis that IGF-1R regulates DNA double strand break (DSB) repair. We tested effects of IGF-1R siRNA transfection on the repair of radiation-induced DSBs by immunoblotting and immunofluorescence for γH2AX, and pulsed-field gel electrophoresis. Homologous recombination (HR) was quantified by reporter assays, and cell cycle distribution by flow cytometry. We confirmed that IGF-1R depletion sensitized DU145 and PC3 prostate cancer cells to ionizing radiation. DU145 control transfectants resolved radiation-induced DSBs within 24 h, while IGF-1R depleted cells contained 30-40% unrepaired breaks at 24 h. IGF-1R depletion induced significant reduction in DSB repair by HR, although the magnitude of the repair defect suggests additional contributory factors. Radiation-induced G2-M arrest was attenuated by IGF-1R depletion, potentially suppressing cell cycle-dependent processes required for HR. In contrast, IGF-1R depletion induced only minor radiosensitization in LNCaP cells, and did not influence repair. Cell cycle profiles were similar to DU145, so were unlikely to account for differences in repair responses. These data indicate a role for IGF-1R in DSB repair, at least in part via HR, and support use of IGF-1R inhibitors with DNA damaging cancer treatments. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Depletion of Pokemon gene inhibits hepatocellular carcinoma cell growth through inhibition of H-ras.

Science.gov (United States)

Zhang, Quan-Le; Tian, De-An; Xu, Xiang-Jiang

2011-01-01

Pokemon is a transcription repressor which plays a critical role in cell transformation and malignancy. However, little is known about its effect on the development and progression of hepatocellular carcinoma (HCC). The aim of this study was to investigate the expression of Pokemon in human HCC tissues and the biological behavior of Pokemon in HCC cells in which it is overexpressed. We also explored the expression of potential downstream cofactors of Pokemon. Reverse transcription polymerase chain reaction and Western blot analysis were used to investigate the expression of Pokemon in tissues of 30 HCC patients. We then examined cell proliferation or apoptosis and β-catenin or H-ras expression in Pokemon-depleted HepG(2) cells using DNA vector-based RNA interference technology. Pokemon was markedly expressed in 22/30 (73.3%) HCC tissues, with expression levels higher than in adjacent normal liver tissues (p Pokemon inhibited proliferation of HepG(2) or induced apoptosis. Also, H-ras expression decreased to a large extent. Pokemon exerts its oncogenic activity in the development of HCC by promoting cancer cell growth and reducing apoptosis, and the effect may be mediated by H-ras. Copyright © 2011 S. Karger AG, Basel.

Reverse depletion effects and the determination of ligand density on some spherical bioparticles

Energy Technology Data Exchange (ETDEWEB)

Wang, Chunxiang [Heilongjiang Bayi Agricultural University (China); Liu, Yanhui, E-mail: ionazati@itp.ac.cn; Fan, Yangtao; Liu, Yijun; Li, Qiancheng; Xu, Houqiang, E-mail: houqiangxu@yahoo.com [Guizhou University (China)

2016-06-15

In cell environments crowded with macromolecules, the depletion effects act and assist in the assembly of a wide range of cellular structures, from the cytoskeleton to the chromatin loop, which are well accepted. But a recent quantum dot experiment indicated that the dimensions of the receptor–ligand complex have strong effects on the size-dependent exclusion of proteins in cell environments. In this article, a continuum elastic model is constructed to resolve the competition between the dimension of the receptor–ligand complex and depletion effects in the endocytosis of a spherical virus-like bioparticle. Our results show that the depletion effects do not always assist endocytosis of a spherical virus-like bioparticle; while the dimension of the ligand–receptor complex is larger than the size of a small bioparticle in cell environments, the depletion effects do not work and reverse effects appear. The ligand density covered on the virus can be identified quantitatively.

Transient B cell depletion or improved transgene expression by codon optimization promote tolerance to factor VIII in gene therapy.

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Brandon K Sack

Full Text Available The major complication in the treatment of hemophilia A is the development of neutralizing antibodies (inhibitors against factor VIII (FVIII. The current method for eradicating inhibitors, termed immune tolerance induction (ITI, is costly and protracted. Clinical protocols that prevent rather than treat inhibitors are not yet established. Liver-directed gene therapy hopes to achieve long-term correction of the disease while also inducing immune tolerance. We sought to investigate the use of adeno-associated viral (serotype 8 gene transfer to induce tolerance to human B domain deleted FVIII in hemophilia A mice. We administered an AAV8 vector with either human B domain deleted FVIII or a codon-optimized transgene, both under a liver-specific promoter to two strains of hemophilia A mice. Protein therapy or gene therapy was given either alone or in conjunction with anti-CD20 antibody-mediated B cell depletion. Gene therapy with a low-expressing vector resulted in sustained near-therapeutic expression. However, supplementary protein therapy revealed that gene transfer had sensitized mice to hFVIII in a high-responder strain but not in mice of a low-responding strain. This heightened response was ameliorated when gene therapy was delivered with anti-murine CD20 treatment. Transient B cell depletion prevented inhibitor formation in protein therapy, but failed to achieve a sustained hypo-responsiveness. Importantly, use of a codon-optimized hFVIII transgene resulted in sustained therapeutic expression and tolerance without a need for B cell depletion. Therefore, anti-CD20 may be beneficial in preventing vector-induced immune priming to FVIII, but higher levels of liver-restricted expression are preferred for tolerance.

Some facts on depleted uranium, its military use, its effects on the health of population

International Nuclear Information System (INIS)

Zucchetti, Massimo

2001-01-01

This paper discusses four main theses concerning the military use of depleted uranium (DU) weapons by NATO in the Nineties. The first thesis is that DU is harmful and dangerous, not only as a chemically toxic agent, but also from the radiological viewpoint. We also demonstrate the strict connection between DU exposure and certain illnesses, such as leukaemia and Hodgkin lymphoma. The second thesis is that western political and military authorities could not be uninformed of the dangers of DU and of its use in wars of the last decade; it is incorrect to say that DU weapons are not forbidden at the international level. The third thesis, based on an estimate of the cases expected to occur in the general population as well as in the armed forces, states that we can reasonably expect soldiers and population to develop tumours caused by DU. The estimate is made by means of population dose codes and dispersion models for atmospheric pollutants. Collective doses are determined, and data are discussed. The fourth thesis shows that the presence of DU is difficult to determine experimentally by field research. Better ways to determine DU pollution are discussed. In addition, we focus on a point that broadens the perspective of the D U problem : DU is only the tip of an iceberg as regards the consequences of what amounts to a chemical, radiological and environmentally destructive war conducted by NATO against the entire environmental system in the Balkans

Sensibility analysis of fuel depletion using different nuclear fuel depletion codes

Energy Technology Data Exchange (ETDEWEB)

Martins, F.; Velasquez, C.E.; Castro, V.F.; Pereira, C.; Silva, C. A. Mello da, E-mail: felipmartins94@gmail.com, E-mail: carlosvelcab@hotmail.com, E-mail: victorfariascastro@gmail.com, E-mail: claubia@nuclear.ufmg.br, E-mail: clarysson@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

2017-07-01

Nowadays, the utilization of different nuclear codes to perform the depletion and criticality calculations has been used to simulated nuclear reactors problems. Therefore, the goal is to analyze the sensibility of the fuel depletion of a PWR assembly using three different nuclear fuel depletion codes. The burnup calculations are performed using the codes MCNP5/ORIGEN2.1 (MONTEBURNS), KENO-VI/ORIGEN-S (TRITONSCALE6.0) and MCNPX (MCNPX/CINDER90). Each nuclear code performs the burnup using different depletion codes. Each depletion code works with collapsed energies from a master library in 1, 3 and 63 groups, respectively. Besides, each code uses different ways to obtain neutron flux that influences the depletions calculation. The results present a comparison of the neutronic parameters and isotopes composition such as criticality and nuclides build-up, the deviation in results are going to be assigned to features of the depletion code in use, such as the different radioactive decay internal libraries and the numerical method involved in solving the coupled differential depletion equations. It is also seen that the longer the period is and the more time steps are chosen, the larger the deviation become. (author)

Sensibility analysis of fuel depletion using different nuclear fuel depletion codes

International Nuclear Information System (INIS)

Martins, F.; Velasquez, C.E.; Castro, V.F.; Pereira, C.; Silva, C. A. Mello da

2017-01-01

Nowadays, the utilization of different nuclear codes to perform the depletion and criticality calculations has been used to simulated nuclear reactors problems. Therefore, the goal is to analyze the sensibility of the fuel depletion of a PWR assembly using three different nuclear fuel depletion codes. The burnup calculations are performed using the codes MCNP5/ORIGEN2.1 (MONTEBURNS), KENO-VI/ORIGEN-S (TRITONSCALE6.0) and MCNPX (MCNPX/CINDER90). Each nuclear code performs the burnup using different depletion codes. Each depletion code works with collapsed energies from a master library in 1, 3 and 63 groups, respectively. Besides, each code uses different ways to obtain neutron flux that influences the depletions calculation. The results present a comparison of the neutronic parameters and isotopes composition such as criticality and nuclides build-up, the deviation in results are going to be assigned to features of the depletion code in use, such as the different radioactive decay internal libraries and the numerical method involved in solving the coupled differential depletion equations. It is also seen that the longer the period is and the more time steps are chosen, the larger the deviation become. (author)

The osteo-inductive activity of bone-marrow-derived mononuclear cells resides within the CD14+ population and is independent of the CD34+ population.

Science.gov (United States)

Henrich, D; Seebach, C; Verboket, R; Schaible, A; Marzi, I; Bonig, H

2018-03-06

Bone marrow mononuclear cells (BMC) seeded on a scaffold of β-tricalcium phosphate (β-TCP) promote bone healing in a critical-size femur defect model. Being BMC a mixed population of predominantly mature haematopoietic cells, which cell type(s) is(are) instrumental for healing remains elusive. Although clinical therapies using BMC are often dubbed as stem cell therapies, whether stem cells are relevant for the therapeutic effects is unclear and, at least in the context of bone repair, seems dubious. Instead, in light of the critical contribution of monocytes and macrophages to tissue development, homeostasis and injury repair, in the current study it was hypothesised that BMC-mediated bone healing derived from the stem cell population. To test this hypothesis, bone remodelling studies were performed in an established athymic rats critical-size femoral defect model, with β-TCP scaffolds augmented with complete BMC or BMC immunomagnetically depleted of stem cells (CD34+) or monocytes/macrophages (CD14+). Bone healing was assessed 8 weeks after transplantation. Compared to BMC-augmented controls, when CD14- BMC, but not CD34- BMC were transplanted into the bone defect, femora possessed dramatically decreased biomechanical stability and new bone formation was markedly reduced, as measured by histology. The degree of vascularisation did not differ between the two groups. It was concluded that the monocyte fraction within the BMC provided critical osteo-inductive cues during fracture healing. Which factors were responsible at the molecular levels remained elusive. However, this study marked a significant progress towards elucidating the mechanisms by which BMC elicit their therapeutic effects, at least in bone regeneration.

Clinical impact of B-cell depletion with the anti-CD20 antibody rituximab in chronic fatigue syndrome: a preliminary case series

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Mella Olav

2009-07-01

Full Text Available Abstract Background Chronic fatigue syndrome (CFS is a disease of unknown aetiology. A patient with CFS had unexpected, marked recovery of CFS symptoms lasting for five months during and after cytotoxic chemotherapy for Hodgkin's disease. We reasoned that the transient CFS recovery was related to methotrexate treatment, which induces immunomodulation in part through B-cell depletion. Methods In a case series, this patient and two additional CFS patients were B-cell depleted by infusion of the monoclonal anti-CD20 antibody rituximab. Results All three had improvement of all CFS symptoms. Patients 1 and 2 had major amelioration from 6 weeks after intervention, patient 3 slight improvement from the same time, but then improved markedly from 26 weeks after intervention. The symptomatic effect lasted until weeks 16, 18 and 44, respectively. At relapse, all were retreated with a single (patient 1 or double rituximab infusion (patients 2 and 3. Again, all three had marked symptom improvement, mimicking their first response. After new symptom recurrence, patients 1 and 2 were given weekly oral methotrexate, patient 1 having effect also from this agent. Patients 1 and 2 were again treated for a third rituximab infusion after new relapse, again with a marked clinical benefit. No unexpected toxicity was seen. Conclusion These observations suggest that B-lymphocytes are involved in CFS pathogenesis for a subset of patients. Benefit for all CFS symptoms, the delayed symptom relief following B-cell depletion, the kinetics of relapses, and the effect also from methotrexate treatment, provide suggestive evidence that B-cells play a significant role in the ongoing clinical features, and that CFS may be amenable to therapeutic interventions aimed at modifying B-cell number and function. More systematic investigations of this therapeutic strategy, and of its biological basis, are now needed.

Controlling the diversity of cell populations in a stem cell culture

NARCIS (Netherlands)

Heo, Inha; Clevers, Hans

2015-01-01

Culturing intestinal stem cells into 3D organoids results in heterogeneous cell populations, reflecting the in vivo cell type diversity. In a recent paper published in Nature, Wang et al. established a culture condition for a highly homogeneous population of intestinal stem cells.

Cholesterol Depletion from a Ceramide/Cholesterol Mixed Monolayer: A Brewster Angle Microscope Study

KAUST Repository

Mandal, Pritam

2016-06-01

Cholesterol is crucial to the mechanical properties of cell membranes that are important to cells’ behavior. Its depletion from the cell membranes could be dramatic. Among cyclodextrins (CDs), methyl beta cyclodextrin (MβCD) is the most efficient to deplete cholesterol (Chol) from biomembranes. Here, we focus on the depletion of cholesterol from a C16 ceramide/cholesterol (C16-Cer/Chol) mixed monolayer using MβCD. While the removal of cholesterol by MβCD depends on the cholesterol concentration in most mixed lipid monolayers, it does not depend very much on the concentration of cholesterol in C16-Cer/Chol monolayers. The surface pressure decay during depletion were described by a stretched exponential that suggested that the cholesterol molecules are unable to diffuse laterally and behave like static traps for the MβCD molecules. Cholesterol depletion causes morphology changes of domains but these disrupted monolayers domains seem to reform even when cholesterol level was low.

Kidins220/ARMS depletion is associated with the neural-to Schwann-like transition in a human neuroblastoma cell line model.

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Rogers, Danny A; Schor, Nina F

2013-03-10

Peripheral neuroblastic tumors exist as a heterogeneous mixture of neuroblastic (N-type) cells and Schwannian stromal (S-type) cells. These stromal cells not only represent a differentiated and less aggressive fraction of the tumor, but also have properties that can influence the further differentiation of nearby malignant cells. In vitro neuroblastoma cultures exhibit similar heterogeneity with N-type and S-type cells representing the neuroblastic and stromal portions of the tumor, respectively, in behavior, morphology, and molecular expression patterns. In this study, we deplete kinase D-interacting substrate of 220kD (Kidins220) with an shRNA construct and thereby cause morphologic transition of the human SH-SY5Y neuroblastoma cell line from N-type to S-type. The resulting cells have similar morphology and expression profile to SH-EP1 cells, a native S-type cell line from the same parent cell line, and to SH-SY5Y cells treated with BrdU, a treatment that induces S-type morphology. Specifically, both Kidins220-deficient SH-SY5Y cells and native SH-EP1 cells demonstrate down-regulation of the genes DCX and STMN2, markers for the neuronal lineage. We further show that Kidins220, DCX and STMN2 are co-down-regulated in cells of S-type morphology generated by methods other than Kidins220 depletion. Finally, we report that the association of low Kidins220 expression with S-type morphology and low DCX and STMN2 expression is demonstrated in spontaneously occurring human peripheral neuroblastic tumors. We propose that Kidins220 is critical in N- to S-type transition of neural crest tumor cells. Copyright © 2013 Elsevier Inc. All rights reserved.

"When the going gets tough, who keeps going?" Depletion sensitivity moderates the ego-depletion effect.

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Salmon, Stefanie J; Adriaanse, Marieke A; De Vet, Emely; Fennis, Bob M; De Ridder, Denise T D

2014-01-01

Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In three studies, we assessed individual differences in depletion sensitivity, and demonstrate that depletion sensitivity moderates ego-depletion effects. The Depletion Sensitivity Scale (DSS) was employed to assess depletion sensitivity. Study 1 employs the DSS to demonstrate that individual differences in sensitivity to ego-depletion exist. Study 2 shows moderate correlations of depletion sensitivity with related self-control concepts, indicating that these scales measure conceptually distinct constructs. Study 3 demonstrates that depletion sensitivity moderates the ego-depletion effect. Specifically, participants who are sensitive to depletion performed worse on a second self-control task, indicating a stronger ego-depletion effect, compared to participants less sensitive to depletion.

When the Going Gets Tough, Who Keeps Going? Depletion Sensitivity Moderates the Ego-Depletion Effect

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Stefanie J. Salmon

2014-06-01

Full Text Available Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In three studies, we assessed individual differences in depletion sensitivity, and demonstrate that depletion sensitivity moderates ego-depletion effects. The Depletion Sensitivity Scale (DSS was employed to assess depletion sensitivity. Study 1 employs the DSS to demonstrate that individual differences in sensitivity to ego-depletion exist. Study 2 shows moderate correlations of depletion sensitivity with related self-control concepts, indicating that these scales measure conceptually distinct constructs. Study 3 demonstrates that depletion sensitivity moderates the ego-depletion effect. Specifically, participants who are sensitive to depletion performed worse on a second self-control task, indicating a stronger ego-depletion effect, compared to participants less sensitive to depletion.

Antifibrotic Therapy in Simian Immunodeficiency Virus Infection Preserves CD4+ T-Cell Populations and Improves Immune Reconstitution With Antiretroviral Therapy

Science.gov (United States)

Estes, Jacob D.; Reilly, Cavan; Trubey, Charles M.; Fletcher, Courtney V.; Cory, Theodore J.; Piatak, Michael; Russ, Samuel; Anderson, Jodi; Reimann, Thomas G.; Star, Robert; Smith, Anthony; Tracy, Russell P.; Berglund, Anna; Schmidt, Thomas; Coalter, Vicky; Chertova, Elena; Smedley, Jeremy; Haase, Ashley T.; Lifson, Jeffrey D.; Schacker, Timothy W.

2015-01-01

Even with prolonged antiretroviral therapy (ART), many human immunodeficiency virus-infected individuals have <500 CD4+ T cells/µL, and CD4+ T cells in lymphoid tissues remain severely depleted, due in part to fibrosis of the paracortical T-cell zone (TZ) that impairs homeostatic mechanisms required for T-cell survival. We therefore used antifibrotic therapy in simian immunodeficiency virus-infected rhesus macaques to determine whether decreased TZ fibrosis would improve reconstitution of peripheral and lymphoid CD4+ T cells. Treatment with the antifibrotic drug pirfenidone preserved TZ architecture and was associated with significantly larger populations of CD4+ T cells in peripheral blood and lymphoid tissues. Combining pirfenidone with an ART regimen was associated with greater preservation of CD4+ T cells than ART alone and was also associated with higher pirfenidone concentrations. These data support a potential role for antifibrotic drug treatment as adjunctive therapy with ART to improve immune reconstitution. PMID:25246534

Autoantibody levels in myositis patients correlate with clinical response during B cell depletion with rituximab.

Science.gov (United States)

Aggarwal, Rohit; Oddis, Chester V; Goudeau, Danielle; Koontz, Diane; Qi, Zengbiao; Reed, Ann M; Ascherman, Dana P; Levesque, Marc C

2016-06-01

To determine the longitudinal trends in serum levels of four myositis-associated autoantibodies: anti-Jo-1, -transcription intermediary factor 1 γ (TIF1-γ), -signal recognition particle (SRP) and -Mi-2, after B cell depletion with rituximab, and to determine the longitudinal association of these autoantibody levels with disease activity as measured by myositis core-set measures (CSMs). Treatment-resistant adult and pediatric myositis subjects (n = 200) received rituximab in the 44-week Rituximab in Myositis Trial. CSMs [muscle enzymes, manual muscle testing (MMT), physician and patient global disease activity, HAQ, and extramuscular disease activity] were evaluated monthly and anti-Jo-1 (n = 28), -TIF1-γ (n = 23), -SRP (n = 25) and -Mi-2 (n = 26) serum levels were measured using validated quantitative ELISAs. Temporal trends and the longitudinal relationship between myositis-associated autoantibodies levels and CSM were estimated using linear mixed models. Following rituximab, anti-Jo-1 levels decreased over time (P myositis subjects decreased after B cell depletion and were correlated with changes in disease activity, whereas anti-SRP levels were only associated with longitudinal muscle enzyme levels. The strong association of anti-Jo-1 levels with clinical outcomes suggests that anti-Jo-1 autoantibodies may be a good biomarker for disease activity. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Measuring local depletion of terrestrial game vertebrates by central-place hunters in rural Amazonia.

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Mark I Abrahams

Full Text Available The degree to which terrestrial vertebrate populations are depleted in tropical forests occupied by human communities has been the subject of an intense polarising debate that has important conservation implications. Conservation ecologists and practitioners are divided over the extent to which community-based subsistence offtake is compatible with ecologically functional populations of tropical forest game species. To quantify depletion envelopes of forest vertebrates around human communities, we deployed a total of 383 camera trap stations and 78 quantitative interviews to survey the peri-community areas controlled by 60 semi-subsistence communities over a combined area of over 3.2 million hectares in the Médio Juruá and Uatumã regions of Central-Western Brazilian Amazonia. Our results largely conform with prior evidence that hunting large-bodied vertebrates reduces wildlife populations near settlements, such that they are only found at a distance to settlements where they are hunted less frequently. Camera trap data suggest that a select few harvest-sensitive species, including lowland tapir, are either repelled or depleted by human communities. Nocturnal and cathemeral species were detected relatively more frequently in disturbed areas close to communities, but individual species did not necessarily shift their activity patterns. Group biomass of all species was depressed in the wider neighbourhood of urban areas rather than communities. Interview data suggest that species traits, especially group size and body mass, mediate these relationships. Large-bodied, large-group-living species are detected farther from communities as reported by experienced informants. Long-established communities in our study regions have not "emptied" the surrounding forest. Low human population density and low hunting offtake due to abundant sources of alternative aquatic protein, suggest that these communities represent a best-case scenario for sustainable

Measuring local depletion of terrestrial game vertebrates by central-place hunters in rural Amazonia

Science.gov (United States)

Peres, Carlos A.; Costa, Hugo C. M.

2017-01-01

The degree to which terrestrial vertebrate populations are depleted in tropical forests occupied by human communities has been the subject of an intense polarising debate that has important conservation implications. Conservation ecologists and practitioners are divided over the extent to which community-based subsistence offtake is compatible with ecologically functional populations of tropical forest game species. To quantify depletion envelopes of forest vertebrates around human communities, we deployed a total of 383 camera trap stations and 78 quantitative interviews to survey the peri-community areas controlled by 60 semi-subsistence communities over a combined area of over 3.2 million hectares in the Médio Juruá and Uatumã regions of Central-Western Brazilian Amazonia. Our results largely conform with prior evidence that hunting large-bodied vertebrates reduces wildlife populations near settlements, such that they are only found at a distance to settlements where they are hunted less frequently. Camera trap data suggest that a select few harvest-sensitive species, including lowland tapir, are either repelled or depleted by human communities. Nocturnal and cathemeral species were detected relatively more frequently in disturbed areas close to communities, but individual species did not necessarily shift their activity patterns. Group biomass of all species was depressed in the wider neighbourhood of urban areas rather than communities. Interview data suggest that species traits, especially group size and body mass, mediate these relationships. Large-bodied, large-group-living species are detected farther from communities as reported by experienced informants. Long-established communities in our study regions have not “emptied” the surrounding forest. Low human population density and low hunting offtake due to abundant sources of alternative aquatic protein, suggest that these communities represent a best-case scenario for sustainable hunting of

B-cell depletion is protective against anti-AAV capsid immune response: a human subject case study

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M Corti

2014-01-01

Full Text Available Gene therapy strategies for congenital myopathies may require repeat administration of adeno-associated viral (AAV vectors due to aspects of the clinical application, such as: (i administration of doses below therapeutic efficacy in patients enrolled in early phase clinical trials; (ii progressive reduction of the therapeutic gene expression over time as a result of increasing muscle mass in patients treated at a young age; and (iii a possibly faster depletion of pathogenic myofibers in this patient population. Immune response triggered by the first vector administration, and to subsequent doses, represents a major obstacle for successful gene transfer in young patients. Anti-capsid and anti-transgene product related humoral and cell-mediated responses have been previously observed in all preclinical models and human subjects who received gene therapy or enzyme replacement therapy (ERT for congenital myopathies. Immune responses may result in reduced efficacy of the gene transfer over time and/or may preclude for the possibility of re-administration of the same vector. In this study, we evaluated the immune response of a Pompe patient dosed with an AAV1-GAA vector after receiving Rituximab and Sirolimus to modulate reactions against ERT. A key finding of this single subject case report is the observation that B-cell ablation with rituximab prior to AAV vector exposure results in non-responsiveness to both capsid and transgene, therefore allowing the possibility of repeat administration in the future. This observation is significant for future gene therapy studies and establishes a clinically relevant approach to blocking immune responses to AAV vectors.

Creatine pretreatment protects cortical axons from energy depletion in vitro

Science.gov (United States)

Shen, Hua; Goldberg, Mark P.

2012-01-01

Creatine is a natural nitrogenous guanidino compound involved in bioenergy metabolism. Although creatine has been shown to protect neurons of the central nervous system (CNS) from experimental hypoxia/ischemia, it remains unclear if creatine may also protect CNS axons, and if the potential axonal protection depends on glial cells. To evaluate the direct impact of creatine on CNS axons, cortical axons were cultured in a separate compartment from their somas and proximal neurites using a modified two-compartment culture device. Axons in the axon compartment were subjected to acute energy depletion, an in vitro model of white matter ischemia, by exposure to 6 mM sodium azide for 30 min in the absence of glucose and pyruvate. Energy depletion reduced axonal ATP by 65%, depolarized axonal resting potential, and damaged 75% of axons. Application of creatine (10 mM) to both compartments of the culture at 24 h prior to energy depletion significantly reduced axonal damage by 50%. In line with the role of creatine in the bioenergy metabolism, this application also alleviated the axonal ATP loss and depolarization. Inhibition of axonal depolarization by blocking sodium influx with tetrodotoxin also effectively reduced the axonal damage caused by energy depletion. Further study revealed that the creatine effect was independent of glial cells, as axonal protection was sustained even when creatine was applied only to the axon compartment (free from somas and glial cells) for as little as 2 h. In contrast, application of creatine after energy depletion did not protect axons. The data provide the first evidence that creatine pretreatment may directly protect CNS axons from energy deficiency. PMID:22521466

Specific depletion of mature T lymphocytes from human bone marrow

DEFF Research Database (Denmark)

Geisler, C; Møller, J; Plesner, T

1989-01-01

An effective method for specific depletion of mature T lymphocytes from human bone marrow mononuclear cells (BMMC) with preservation of prethymic T cells and natural killer (NK) cells is presented. The BMMC were incubated with F101.01, a monoclonal antibody recognizing an epitope of the T...

Meta-analysis of depleted uranium levels in the Balkan region.

Science.gov (United States)

Besic, Larisa; Muhovic, Imer; Asic, Adna; Kurtovic-Kozaric, Amina

2017-06-01

In recent years, contradicting data has been published on the connection between the presence of depleted uranium and an increased cancer incidence among military personnel deployed in the Balkans during the 1992-1999 wars. This has led to numerous research articles investigating possible depleted uranium contamination of the afflicted regions of the Balkan Peninsula, namely Bosnia & Herzegovina, Serbia, Kosovo and Montenegro. The aim of this study was to collect data from previously published reports investigating the levels of depleted uranium in the Balkans and to present the data in the form of a meta-analysis. This would provide a clear image of the extent of depleted uranium contamination after the Balkan conflict. In addition, we tested the hypothesis that there is a correlation between the levels of depleted uranium and the assumed depleted uranium-related health effects. Our results suggest that the majority of the examined sites contain natural uranium, while the area of Kosovo appears to be most heavily afflicted by depleted uranium pollution, followed by Bosnia & Herzegovina. Furthermore, the results indicate that it is not possible to make a valid correlation between the health effects and depleted uranium-contaminated areas. We therefore suggest a structured collaborative plan of action where long-term monitoring of the residents of depleted uranium-afflicted areas would be performed. In conclusion, while the possibility of depleted uranium toxicity in post-conflict regions appears to exist, there currently exists no definitive proof of such effects, due to insufficient studies of potentially afflicted populations, in addition to the lack of a common epidemiological approach in the reviewed literature. Copyright © 2017 Elsevier Ltd. All rights reserved.

Depletion of key protein components of the RISC pathway impairs pre-ribosomal RNA processing.

Science.gov (United States)

Liang, Xue-Hai; Crooke, Stanley T

2011-06-01

Little is known about whether components of the RNA-induced silencing complex (RISC) mediate the biogenesis of RNAs other than miRNA. Here, we show that depletion of key proteins of the RISC pathway by antisense oligonucleotides significantly impairs pre-rRNA processing in human cells. In cells depleted of Drosha or Dicer, different precursors to 5.8S rRNA strongly accumulated, without affecting normal endonucleolytic cleavages. Moderate yet distinct processing defects were also observed in Ago2-depleted cells. Physical links between pre-rRNA and these proteins were identified by co-immunoprecipitation analyses. Interestingly, simultaneous depletion of Dicer and Drosha led to a different processing defect, causing slower production of 28S rRNA and its precursor. Both Dicer and Ago2 were detected in the nuclear fraction, and reduction of Dicer altered the structure of the nucleolus, where pre-rRNA processing occurs. Together, these results suggest that Drosha and Dicer are implicated in rRNA biogenesis.

Electrophoretic analysis of cyanide depletion by Pseudomonas alcaligenes.

Science.gov (United States)

Zaugg, S E; Davidson, R A; Walker, J C; Walker, E B

1997-02-01

Bacterial-facilitated depletion of cyanide is under development for remediation of heap leach operations in the gold mining industry. Capillary electrophoresis was found to be a powerful tool for quantifying cyanide depletion. Changes in cyanide concentration in aqueous suspensions of Pseudomonas alcaligenes bacteria and cyanide at elevated pH were easily monitored by capillary electrophoresis. The resulting data can be used to study rates of cyanide depletion by this strain of bacteria. Concentrations of these bacteria at 10(5) cells/mL were found to reduce cyanide from 100 ppm to less than 8 ppm in four days. In addition, other ions of interest in cyanide metabolism, such as formate, can be simultaneously analyzed. Direct UV detection of cyanide at 192 nm further simplifies the analytical method for these ions.

EMT factor Zeb1 depletion in dendritic cells enhances Helminth clearance in mice by increasing Th2 cell differentiation

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Shuchi Smita

2017-10-01

Full Text Available Dendritic cells are professional antigen presenting cells that act as bridging link between innate and adaptive immune system. They are equipped with pathogen recognition receptors (PRR to identify the pathogen associated molecular pattern (PAMPS on any antigen. DCs elicit an immune response through polarizing T cells towards various subtypes like Th1, Th2 & Tregs. Though DC-T cell interaction has been widely studied, but how this single DC molecule amalgamate various transcriptional signals for translating the message to the T cells and induce diverse immunological responses still needs to be unraveled. Therefore to identify the role of transcription factor in immune programming we have targeted the largest member of TFs family, Zinc Finger Transcription Factors (ZF-TFs. Among various ZF-TFs we have narrowed our study to three interesting candidates Zeb1, Zeb2 and Zbtb10 based on their expression in DCs from an unpublished microarray data. Here in this study we have tried to understand the role of Zeb1, master regulator of EMT program in orchestrating DC responses. Zeb1 links the epithelial – mesenchymal transition and has been widely studied molecule in cancer biology. Except for the fact that it act as transcriptional repressor and represses IL2 gene promoter no other reports are available in immune biology, thereby rendering it a perfect candidate to be used for detailed characterization in dendritic cells. In our study, we found that Zeb1 depleted CD8α+DCs shows an increase in co-stimulatory marker like CD80 & CD86 whereas there is a decrease in MHC class I & II molecule. Thereafter at transcript & protein level we found decrease in pro-inflammatory & anti-inflammatory cytokine like IL6 & IL10 respectively, the bioactive form of IL12 i.e. IL12p70 which polarizes T cells towards Th1 response showed a significant decrease in bio-plex when compared with control CD8α+DCs. The regulatory markers which develop regulatory T cells like Pdl1, IL

MILD CHOLESTEROL DEPLETION REDUCES AMYLOID-β PRODUCTION BY IMPAIRING APP TRAFFICKING TO THE CELL SURFACE

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Guardia-Laguarta, Cristina; Coma, Mireia; Pera, Marta; Clarimón, Jordi; Sereno, Lidia; Agulló, José M.; Molina-Porcel, Laura; Gallardo, Eduard; Deng, Amy; Berezovska, Oksana; Hyman, Bradley T.; Blesa, Rafael; Gómez-Isla, Teresa; Lleó, Alberto

2009-01-01

It has been suggested that cellular cholesterol levels can modulate the metabolism of the amyloid precursor protein (APP) but the underlying mechanism remains controversial. In the current study, we investigate in detail the relationship between cholesterol reduction, APP processing and γ-secretase function in cell culture studies. We found that mild membrane cholesterol reduction led to a decrease in Aβ40 and Aβ42 in different cell types. We did not detect changes in APP intracellular domain or Notch intracellular domain generation. Western blot analyses showed a cholesterol-dependent decrease in the APP C-terminal fragments and cell surface APP. Finally, we applied a fluorescence resonance energy transfer (FRET)-based technique to study APP-Presenilin 1 (PS1) interactions and lipid rafts in intact cells. Our data indicate that cholesterol depletion reduces association of APP into lipid rafts and disrupts APP-PS1 interaction. Taken together, our results suggest that mild membrane cholesterol reduction impacts the cleavage of APP upstream of γ-secretase and appears to be mediated by changes in APP trafficking and partitioning into lipid rafts. PMID:19457132

IgE antipolymyxin B antibody formation in a T cell-depleted bone marrow transplant patient

International Nuclear Information System (INIS)

Lakin, J.D.; Grace, W.R.; Sell, K.W.

1975-01-01

The production of IgE-class antibody specific for polymyxin B is documented in an 18-year-old white female acute myelocytic leukemic patient in relapse. The patient was rendered T cell--deficient by total-body x irradiation and antihuman thymocyte globulin for the purpose of bone marrow transplantation. Thereafter, symptoms of nasal congestion, rhinorrhea, and perinasal urtication produced by topical application of a polymyxin solution were noted. Reaginic activity mediated by an IgE antibody against polymyxin is documented by Prausnitz-Kuestner--type passive transfer reactions and by an indirect hemagglutination technique developed for these studies. The occurrence of type I hypersensitivity to this topical antibiotic is rare. It is speculated that pharmaceuticals normally having a low sensitizing potential might demonstrate increased reaginic immunogenicity in a spontaneously or iatrogenically T cell-depleted patient

NAD+ depletion or PAR polymer formation: which plays the role of executioner in ischaemic cell death?

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Siegel, C; McCullough, L D

2011-09-01

Multiple cell death pathways are activated in cerebral ischaemia. Much of the initial injury, especially in the core of the infarct where cerebral blood flow is severely reduced, is necrotic and secondary to severe energy failure. However, there is considerable evidence that delayed cell death continues for several days, primarily in the penumbral region. As reperfusion therapies grow in number and effectiveness, restoration of blood flow early after injury may lead to a shift towards apoptosis. It is important to elucidate what are the key mediators of apoptotic cell death after stroke, as inhibition of apoptosis may have therapeutic implications. There are two well described pathways that lead to apoptotic cell death; the caspase pathway and the more recently described caspase-independent pathway triggered by poly-ADP-ribose polymers (PARP) activation. Caspase-induced cell death is initiated by release of mitochondrial cytochrome c, formation of the cytosolic apoptosome, and activation of endonucleases leading to a multitude of small randomly cleaved DNA fragments. In contrast caspase-independent cell death is secondary to activation of apoptosis inducing factor (AIF). Mitochondrial AIF translocates to the nucleus, where it induces peripheral chromatin condensation, as well as characteristic high-molecular-weight (50 kbp) DNA fragmentation. Although caspase-independent cell death has been recognized for some time and is known to contribute to ischaemic injury, the upstream triggering events leading to activation of this pathway remain unclear. The two major theories are that ischaemia leads to nicotinamide adenine dinucleotide (NAD+) depletion and subsequent energy failure, or alternatively that cell death is directly triggered by a pro-apoptotic factor produced by activation of the DNA repair enzyme PARP. PARP activation is robust in the ischaemic brain producing variable lengths of poly-ADP-ribose (PAR) polymers as byproducts of PARP activation. PAR polymers

Ovarian cancer stem cells are enriched in side population and aldehyde dehydrogenase bright overlapping population.

Directory of Open Access Journals (Sweden)

Kazuyo Yasuda

Full Text Available Cancer stem-like cells (CSCs/cancer-initiaiting cells (CICs are defined as a small population of cancer cells that have self-renewal capacity, differentiation potential and high tumor-initiating ability. CSCs/CICs of ovarian cancer have been isolated by side population (SP analysis, ALDEFLUOR assay and using cell surface markers. However, these approaches are not definitive markers for CSCs/CICs, and it is necessary to refine recent methods for identifying more highly purified CSCs/CICs. In this study, we analyzed SP cells and aldehyde dehydrogenese bright (ALDH(Br cells from ovarian cancer cells. Both SP cells and ALDH(Br cells exhibited higher tumor-initiating ability and higher expression level of a stem cell marker, sex determining region Y-box 2 (SOX2, than those of main population (MP cells and ALDH(Low cells, respectively. We analyzed an SP and ALDH(Br overlapping population (SP/ALDH(Br, and the SP/ALDH(Br population exhibited higher tumor-initiating ability than that of SP cells or ALDH(Br cells, enabling initiation of tumor with as few as 10(2 cells. Furthermore, SP/ADLH(Br population showed higher sphere-forming ability, cisplatin resistance, adipocyte differentiation ability and expression of SOX2 than those of SP/ALDH(Low, MP/ALDH(Br and MP/ALDH(Low cells. Gene knockdown of SOX2 suppressed the tumor-initiation of ovarian cancer cells. An SP/ALDH(Br population was detected in several gynecological cancer cells with ratios of 0.1% for HEC-1 endometrioid adenocarcinoma cells to 1% for MCAS ovary mucinous adenocarcinoma cells. Taken together, use of the SP and ALDH(Br overlapping population is a promising approach to isolate highly purified CSCs/CICs and SOX2 might be a novel functional marker for ovarian CSCs/CICs.

A virus-sensitive suppressor cell is involved in the regulation of human allospecific T cell-mediated cytotoxicity

International Nuclear Information System (INIS)

Muluk, S.C.; Bernstein, D.C.; Shearer, G.M.

1989-01-01

The in vitro generation of allospecific CTL by human PBMC was enhanced 4- to 16-fold by sequential plastic and nylon wool adherence, which depleted the PBMC of macrophages and B cells. The enhanced CTL response was suppressed by adding back irradiated, unfractionated PBMC or adherent cells to the depleted cells. This finding suggests that the enhanced CTL response was not simply a consequence of enrichment of T cells, but was instead due to active suppression by radioresistant cells contained in the adherent fraction. Of note is the finding that, unlike the CTL response, the proliferative response to allostimulation was not affected by the removal of adherent cells. The suppressor function could be abrogated by preincubation of irradiated PBMC with influenza A virus before the coculture with depleted cells. Furthermore, costimulation of unfractionated PBMC with influenza A virus and allogeneic stimulators augmented allospecific CTL activity. Thus, in the adherent fraction of human PBMC, there appears to be a native suppressor population that can be functionally inactivated by virus. This result may account for the clinical observation of increased allograft rejection after certain viral infections

Inhibition of tumor growth in syngenetic chimeric mice mediated by a depletion of suppressor T cells

International Nuclear Information System (INIS)

Rotter, V.; Trainin, N.

1975-01-01

Syngeneic chimeric (lethally irradiated and reconstituted with syngeneic bone marrow cells) mice manifested an increased resistance to the development of Lewis lung carcinoma. In addition, these mice had a higher response to polyvinylpyrrolidone and a reduced reactivity to T mitogens. The present findings suggest that syngeneic chimeric mice lack suppressor T cells shown to regulate the development of Lewis lung tumor and the response to polyvinylpyrrolidone. Other components of the T cell population, such as helper cells responding to sheep red blood cells or cells involved in allograft rejection, assayed in these syngeneic chimeras were found unaffected. The fact that chimeric mice are deficient in a certain suppressor T cell population whereas other T activities are normal suggests the existence of different cell lines within the T cell population. (U.S.)

Deuterium-depleted water

International Nuclear Information System (INIS)

Stefanescu, Ion; Steflea, Dumitru; Saros-Rogobete, Irina; Titescu, Gheorghe; Tamaian, Radu

2001-01-01

Deuterium-depleted water represents water that has an isotopic content smaller than 145 ppm D/(D+H) which is the natural isotopic content of water. Deuterium depleted water is produced by vacuum distillation in columns equipped with structured packing made from phosphor bronze or stainless steel. Deuterium-depleted water, the production technique and structured packing are patents of National Institute of Research - Development for Cryogenics and Isotopic Technologies at Rm. Valcea. Researches made in the last few years showed the deuterium-depleted water is a biological active product that could have many applications in medicine and agriculture. (authors)

Depletion of pro-oncogenic RUNX2 enhances gemcitabine (GEM) sensitivity of p53-mutated pancreatic cancer Panc-1 cells through the induction of pro-apoptotic TAp63.

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Ozaki, Toshinori; Nakamura, Mizuyo; Ogata, Takehiro; Sang, Meijie; Yoda, Hiroyuki; Hiraoka, Kiriko; Sang, Meixiang; Shimozato, Osamu

2016-11-01

Recently, we have described that siRNA-mediated silencing of runt-related transcription factor 2 (RUNX2) improves anti-cancer drug gemcitabine (GEM) sensitivity of p53-deficient human pancreatic cancer AsPC-1 cells through the augmentation of p53 family TAp63-dependent cell death pathway. In this manuscript, we have extended our study to p53-mutated human pancreatic cancer Panc-1 cells. According to our present results, knockdown of mutant p53 alone had a marginal effect on GEM-mediated cell death of Panc-1 cells. We then sought to deplete RUNX2 using siRNA in Panc-1 cells and examined its effect on GEM sensitivity. Under our experimental conditions, RUNX2 knockdown caused a significant enhancement of GEM sensitivity of Panc-1 cells. Notably, GEM-mediated induction of TAp63 but not of TAp73 was further stimulated in RUNX2-depleted Panc-1 cells, indicating that, like AsPC-1 cells, TAp63 might play a pivotal role in the regulation of GEM sensitivity of Panc-1 cells. Consistent with this notion, forced expression of TAp63α in Panc-1 cells promoted cell cycle arrest and/or cell death, and massively increased luciferase activities driven by TAp63-target gene promoters such as p21WAF1 and NOXA. In addition, immunoprecipitation experiments indicated that RUNX2 forms a complex with TAp63 in Panc-1 cells. Taken together, our current observations strongly suggest that depletion of RUNX2 enhances the cytotoxic effect of GEM on p53-mutated Panc-1 cells through the stimulation of TAp63-dependent cell death pathway even in the presence of a large amount of pro-oncogenic mutant p53, and might provide an attractive strategy to treat pancreatic cancer patients with p53 mutations.

[Effect of endonuclease G depletion on plasmid DNA uptake and levels of homologous recombination in hela cells].

Science.gov (United States)

Misic, V; El-Mogy, M; Geng, S; Haj-Ahmad, Y

2016-01-01

Endonuclease G (EndoG) is a mitochondrial apoptosis regulator that also has roles outside of programmed cell death. It has been implicated as a defence DNase involved in the degradation of exogenous DNA after transfection of mammalian cells and in homologous recombination of viral and endogenous DNA. In this study, we looked at the effect of EndoG depletion on plasmid DNA uptake and the levels of homologous recombination in HeLa cells. We show that the proposed defence role of EndoG against uptake of non-viral DNA vectors does not extend to the cervical carcinoma HeLa cells, as targeting of EndoG expression by RNA interference failed to increase intracellular plasmid DNA levels. However, reducing EndoG levels in HeLa cells resulted in a statistically significant reduction of homologous recombination between two plasmid DNA substrates. These findings suggest that non-viral DNA vectors are also substrates for EndoG in its role in homologous recombination.

Nanotoxicity of pure silica mediated through oxidant generation rather than glutathione depletion in human lung epithelial cells.

Science.gov (United States)

Akhtar, Mohd Javed; Ahamed, Maqusood; Kumar, Sudhir; Siddiqui, Huma; Patil, Govil; Ashquin, Mohd; Ahmad, Iqbal

2010-10-09

Though, oxidative stress has been implicated in silica nanoparticles induced toxicity both in vitro and in vivo, but no similarities exist regarding dose-response relationship. This discrepancy may, partly, be due to associated impurities of trace metals that may present in varying amounts. Here, cytotoxicity and oxidative stress parameters of two sizes (10 nm and 80 nm) of pure silica nanoparticles was determined in human lung epithelial cells (A549 cells). Both sizes of silica nanoparticles induced dose-dependent cytotoxicity as measured by MTT [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] and lactate dehydrogenase (LDH) assays. Silica nanoparticles were also found to induce oxidative stress in dose-dependent manner indicated by induction of reactive oxygen species (ROS) generation, and membrane lipid peroxidation (LPO). However, both sizes of silica nanoparticles had little effect on intracellular glutathione (GSH) level and the activities of glutathione metabolizing enzymes; glutathione reductase (GR) and glutathione peroxidase (GPx). Buthionine-[S,R]-sulfoximine (BSO) plus silica nanoparticles did not result in significant GSH depletion than that caused by BSO alone nor N-acetyl cysteine (NAC) afforded significant protection from ROS and LPO induced by silica nanoparticles. The rather unaltered level of GSH is also supported by finding no appreciable alteration in the level of GR and GPx. Our data suggest that the silica nanoparticles exert toxicity in A549 cells through the oxidant generation (ROS and LPO) rather than the depletion of GSH. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Ego depletion in visual perception: Ego-depleted viewers experience less ambiguous figure reversal.

Science.gov (United States)

Wimmer, Marina C; Stirk, Steven; Hancock, Peter J B

2017-10-01

This study examined the effects of ego depletion on ambiguous figure perception. Adults (N = 315) received an ego depletion task and were subsequently tested on their inhibitory control abilities that were indexed by the Stroop task (Experiment 1) and their ability to perceive both interpretations of ambiguous figures that was indexed by reversal (Experiment 2). Ego depletion had a very small effect on reducing inhibitory control (Cohen's d = .15) (Experiment 1). Ego-depleted participants had a tendency to take longer to respond in Stroop trials. In Experiment 2, ego depletion had small to medium effects on the experience of reversal. Ego-depleted viewers tended to take longer to reverse ambiguous figures (duration to first reversal) when naïve of the ambiguity and experienced less reversal both when naïve and informed of the ambiguity. Together, findings suggest that ego depletion has small effects on inhibitory control and small to medium effects on bottom-up and top-down perceptual processes. The depletion of cognitive resources can reduce our visual perceptual experience.

Common variable immunodeficiency in horses is characterized by B cell depletion in primary and secondary lymphoid tissues.

Science.gov (United States)

Flaminio, M Julia B F; Tallmadge, Rebecca L; Salles-Gomes, Cristina O M; Matychak, Mary Beth

2009-01-01

Common variable immunodeficiency (CVID) in horse patients is characterized by late-onset B cell lymphopenia or depletion, hypo- or agammaglobulinemia, impaired humoral response to tetanus toxoid vaccination, and recurrent fevers and bacterial infections. This study describes the clinical and immunologic findings of 14 affected horses (average age 10.7 +/- 4.4 years) of both genders (six females, eight males) and different breeds (eight Thoroughbreds, four Quarter Horses, one Warmblood, one Pony). Serial immunological testing in peripheral blood revealed persistent, severe B cell lymphopenia (mean 1.3 +/- 2.3% positive cells) in all patients. Serum IgG (range horses. Serum IgA concentrations declined with time. Histopathology and immunohistochemistry revealed absence of lymphoid follicles and B cells in primary and secondary lymphoid tissues. CVID is a cause of recurrent pneumonia, septicemia, and meningitis in adult horses and has a grave prognosis for clinical management and survival.

Castration-Resistant Lgr5+ Cells Are Long-Lived Stem Cells Required for Prostatic Regeneration

Directory of Open Access Journals (Sweden)

Bu-er Wang

2015-05-01

Full Text Available The adult prostate possesses a significant regenerative capacity that is of great interest for understanding adult stem cell biology. We demonstrate that leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5 is expressed in a rare population of prostate epithelial progenitor cells, and a castration-resistant Lgr5+ population exists in regressed prostate tissue. Genetic lineage tracing revealed that Lgr5+ cells and their progeny are primarily luminal. Lgr5+ castration-resistant cells are long lived and upon regeneration, both luminal Lgr5+ cells and basal Lgr5+ cells expand. Moreover, single Lgr5+ cells can generate multilineage prostatic structures in renal transplantation assays. Additionally, Lgr5+ cell depletion revealed that the regenerative potential of the castrated adult prostate depends on Lgr5+ cells. Together, these data reveal insights into the cellular hierarchy of castration-resistant Lgr5+ cells, indicate a requirement for Lgr5+ cells during prostatic regeneration, and identify an Lgr5+ adult stem cell population in the prostate.

Phenotype heterogeneity in cancer cell populations

International Nuclear Information System (INIS)

Almeida, Luis; Chisholm, Rebecca; Clairambault, Jean; Escargueil, Alexandre; Lorenzi, Tommaso; Lorz, Alexander; Trélat, Emmanuel

2016-01-01

Phenotype heterogeneity in cancer cell populations, be it of genetic, epigenetic or stochastic origin, has been identified as a main source of resistance to drug treatments and a major source of therapeutic failures in cancers. The molecular mechanisms of drug resistance are partly understood at the single cell level (e.g., overexpression of ABC transporters or of detoxication enzymes), but poorly predictable in tumours, where they are hypothesised to rely on heterogeneity at the cell population scale, which is thus the right level to describe cancer growth and optimise its control by therapeutic strategies in the clinic. We review a few results from the biological literature on the subject, and from mathematical models that have been published to predict and control evolution towards drug resistance in cancer cell populations. We propose, based on the latter, optimisation strategies of combined treatments to limit emergence of drug resistance to cytotoxic drugs in cancer cell populations, in the monoclonal situation, which limited as it is still retains consistent features of cell population heterogeneity. The polyclonal situation, that may be understood as “bet hedging” of the tumour, thus protecting itself from different sources of drug insults, may lie beyond such strategies and will need further developments. In the monoclonal situation, we have designed an optimised therapeutic strategy relying on a scheduled combination of cytotoxic and cytostatic treatments that can be adapted to different situations of cancer treatments. Finally, we review arguments for biological theoretical frameworks proposed at different time and development scales, the so-called atavistic model (diachronic view relying on Darwinian genotype selection in the coursof billions of years) and the Waddington-like epigenetic landscape endowed with evolutionary quasi-potential (synchronic view relying on Lamarckian phenotype instruction of a given genome by reversible mechanisms), to

Phenotype heterogeneity in cancer cell populations

Energy Technology Data Exchange (ETDEWEB)

Almeida, Luis [CNRS UMR 7598, LJLL, & INRIA MAMBA team, Sorbonne Universités, UPMC Univ Paris 06, Boîte courrier 187, 4 Pl. Jussieu, 75252 Paris cedex 05, France, luis@ann.jussieu.fr (France); Chisholm, Rebecca [School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia, rebecca.chisholm@gmail.com (Australia); Clairambault, Jean [INRIA MAMBA team & LJLL, UMR 7598, Sorbonne Universités, UPMC Univ Paris 06, Boîte courrier 187, 4 Pl. Jussieu, 75252 Paris cedex 05, France, jean.clairambault@inria.fr, Corresponding author (France); Escargueil, Alexandre [INSERM “Cancer Biology and Therapeutics”, Sorbonne Universités, UPMC Univ Paris 06, UMR-S 938, CDR St Antoine, Hôpital St Antoine, 184 Fbg. St Antoine, 75571 Paris cedex 12, France, alexandre.escargueil@upmc.fr (France); Lorenzi, Tommaso [CMLA, ENS Cachan, 61, Av. du Président Wilson, 94230 Cachan cedex & INRIA MAMBA team, & LJLL, UMR 7598, UPMC Univ Paris 06, Boîte courrier 187, 4 Pl. Jussieu, 75252 Paris cedex 05, France, tommaso.lorenzi@gmail.com (France); Lorz, Alexander [Sorbonne Universités, UPMC Univ Paris 06, LJLL, UMR 7598 & INRIA Boîte courrier 187, 4 Pl. Jussieu, 75252 Paris cedex 05, France, alex.lorz@ann.jussieu.fr (France); Trélat, Emmanuel [Institut Universitaire de France, Sorbonne Universités, UPMC Univ Paris 06, LJLL, UMR 7598, Boîte courrier 187, UPMC Univ Paris 06, 4 Pl. Jussieu, 75252 Paris cedex 05, France, emmanuel.trelat@upmc.fr (France)

2016-06-08

Phenotype heterogeneity in cancer cell populations, be it of genetic, epigenetic or stochastic origin, has been identified as a main source of resistance to drug treatments and a major source of therapeutic failures in cancers. The molecular mechanisms of drug resistance are partly understood at the single cell level (e.g., overexpression of ABC transporters or of detoxication enzymes), but poorly predictable in tumours, where they are hypothesised to rely on heterogeneity at the cell population scale, which is thus the right level to describe cancer growth and optimise its control by therapeutic strategies in the clinic. We review a few results from the biological literature on the subject, and from mathematical models that have been published to predict and control evolution towards drug resistance in cancer cell populations. We propose, based on the latter, optimisation strategies of combined treatments to limit emergence of drug resistance to cytotoxic drugs in cancer cell populations, in the monoclonal situation, which limited as it is still retains consistent features of cell population heterogeneity. The polyclonal situation, that may be understood as “bet hedging” of the tumour, thus protecting itself from different sources of drug insults, may lie beyond such strategies and will need further developments. In the monoclonal situation, we have designed an optimised therapeutic strategy relying on a scheduled combination of cytotoxic and cytostatic treatments that can be adapted to different situations of cancer treatments. Finally, we review arguments for biological theoretical frameworks proposed at different time and development scales, the so-called atavistic model (diachronic view relying on Darwinian genotype selection in the coursof billions of years) and the Waddington-like epigenetic landscape endowed with evolutionary quasi-potential (synchronic view relying on Lamarckian phenotype instruction of a given genome by reversible mechanisms), to

Phenotype heterogeneity in cancer cell populations

Science.gov (United States)

Almeida, Luis; Chisholm, Rebecca; Clairambault, Jean; Escargueil, Alexandre; Lorenzi, Tommaso; Lorz, Alexander; Trélat, Emmanuel

2016-06-01

Phenotype heterogeneity in cancer cell populations, be it of genetic, epigenetic or stochastic origin, has been identified as a main source of resistance to drug treatments and a major source of therapeutic failures in cancers. The molecular mechanisms of drug resistance are partly understood at the single cell level (e.g., overexpression of ABC transporters or of detoxication enzymes), but poorly predictable in tumours, where they are hypothesised to rely on heterogeneity at the cell population scale, which is thus the right level to describe cancer growth and optimise its control by therapeutic strategies in the clinic. We review a few results from the biological literature on the subject, and from mathematical models that have been published to predict and control evolution towards drug resistance in cancer cell populations. We propose, based on the latter, optimisation strategies of combined treatments to limit emergence of drug resistance to cytotoxic drugs in cancer cell populations, in the monoclonal situation, which limited as it is still retains consistent features of cell population heterogeneity. The polyclonal situation, that may be understood as "bet hedging" of the tumour, thus protecting itself from different sources of drug insults, may lie beyond such strategies and will need further developments. In the monoclonal situation, we have designed an optimised therapeutic strategy relying on a scheduled combination of cytotoxic and cytostatic treatments that can be adapted to different situations of cancer treatments. Finally, we review arguments for biological theoretical frameworks proposed at different time and development scales, the so-called atavistic model (diachronic view relying on Darwinian genotype selection in the coursof billions of years) and the Waddington-like epigenetic landscape endowed with evolutionary quasi-potential (synchronic view relying on Lamarckian phenotype instruction of a given genome by reversible mechanisms), to

Depletion of interstellar elements and the interaction between gas and dust in space

International Nuclear Information System (INIS)

Snow, T.P. Jr.

1975-01-01

Recent data obtained with Copernicus, combined with new results from the literature, indicate that the depletions of interstellar elements may depend on cloud density in a simple way. This is expected if the depletions are due to accretion of gas particles onto grains under presently existing conditions, but is not expected if the depletions take place during the grain formation process, before mixing into the interstellar medium. The suggestion that depletion occurs via accretion may be supported by the existence of a good correlation between depletions and first ionization potentials of the elements, since the latter quantity determines to a great extent the chemical and physical properties, and hence possibly the sticking coefficient, of each species. If the grains do not carry large positive charges, then ion-grain encounters may be important not only in creating the depletions, but also in determining ionization equilibrium, particularly if a large population of very small grains is present

Myoferlin depletion in breast cancer cells promotes mesenchymal to epithelial shape change and stalls invasion.

Directory of Open Access Journals (Sweden)

Ruth Li

Full Text Available Myoferlin (MYOF is a mammalian ferlin protein with homology to ancestral Fer-1, a nematode protein that regulates spermatic membrane fusion, which underlies the amoeboid-like movements of its sperm. Studies in muscle and endothelial cells have reported on the role of myoferlin in membrane repair, endocytosis, myoblast fusion, and the proper expression of various plasma membrane receptors. In this study, using an in vitro human breast cancer cell model, we demonstrate that myoferlin is abundantly expressed in invasive breast tumor cells. Depletion of MYOF using lentiviral-driven shRNA expression revealed that MDA-MB-231 cells reverted to an epithelial morphology, suggesting at least some features of mesenchymal to epithelial transition (MET. These observations were confirmed by the down-regulation of some mesenchymal cell markers (e.g., fibronectin and vimentin and coordinate up-regulation of the E-cadherin epithelial marker. Cell invasion assays using Boyden chambers showed that loss of MYOF led to a significant diminution in invasion through Matrigel or type I collagen, while cell migration was unaffected. PCR array and screening of serum-free culture supernatants from shRNA(MYOF transduced MDA-MB-231 cells indicated a significant reduction in the steady-state levels of several matrix metalloproteinases. These data when considered in toto suggest a novel role of MYOF in breast tumor cell invasion and a potential reversion to an epithelial phenotype upon loss of MYOF.

“When the going gets tough, who keeps going?” Depletion sensitivity moderates the ego-depletion effect

Science.gov (United States)

Salmon, Stefanie J.; Adriaanse, Marieke A.; De Vet, Emely; Fennis, Bob M.; De Ridder, Denise T. D.

2014-01-01

Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In three studies, we assessed individual differences in depletion sensitivity, and demonstrate that depletion sensitivity moderates ego-depletion effects. The Depletion Sensitivity Scale (DSS) was employed to assess depletion sensitivity. Study 1 employs the DSS to demonstrate that individual differences in sensitivity to ego-depletion exist. Study 2 shows moderate correlations of depletion sensitivity with related self-control concepts, indicating that these scales measure conceptually distinct constructs. Study 3 demonstrates that depletion sensitivity moderates the ego-depletion effect. Specifically, participants who are sensitive to depletion performed worse on a second self-control task, indicating a stronger ego-depletion effect, compared to participants less sensitive to depletion. PMID:25009523

An amino acid depleted cell-free protein synthesis system for the incorporation of non-canonical amino acid analogs into proteins.

Science.gov (United States)

Singh-Blom, Amrita; Hughes, Randall A; Ellington, Andrew D

2014-05-20

Residue-specific incorporation of non-canonical amino acids into proteins is usually performed in vivo using amino acid auxotrophic strains and replacing the natural amino acid with an unnatural amino acid analog. Herein, we present an efficient amino acid depleted cell-free protein synthesis system that can be used to study residue-specific replacement of a natural amino acid by an unnatural amino acid analog. This system combines a simple methodology and high protein expression titers with a high-efficiency analog substitution into a target protein. To demonstrate the productivity and efficacy of a cell-free synthesis system for residue-specific incorporation of unnatural amino acids in vitro, we use this system to show that 5-fluorotryptophan and 6-fluorotryptophan substituted streptavidin retain the ability to bind biotin despite protein-wide replacement of a natural amino acid for the amino acid analog. We envisage this amino acid depleted cell-free synthesis system being an economical and convenient format for the high-throughput screening of a myriad of amino acid analogs with a variety of protein targets for the study and functional characterization of proteins substituted with unnatural amino acids when compared to the currently employed in vivo methodologies. Copyright © 2014 Elsevier B.V. All rights reserved.

Choline Phospholipid Metabolites of Human Vascular Endothelial Cells Altered by Cyclooxygenase Inhibition, Growth Factor Depletion, and Paracrine Factors Secreted by Cancer Cells

Directory of Open Access Journals (Sweden)

Noriko Mori

2003-04-01

Full Text Available Magnetic resonance studies have previously shown that solid tumors and cancer cells in culture typically exhibit high phosphocholine and total choline. Treatment of cancer cells with the anti-inflammatory agent, indomethacin (INDO, reverted the phenotype of choline phospholipid metabolites in cancer cells towards a less malignant phenotype. Since endothelial cells form a key component of tumor vasculature, in this study, we used MR spectroscopy to characterize the phenotype of choline phospholipid metabolites in human umbilical vein endothelial cells (HUVECs. We determined the effect of growth factors, the anti-inflammatory agent INDO, and conditioned media obtained from a malignant cell line, on choline phospholipid metabolites. Growth factor depletion or treatment with INDO induced similar changes in the choline phospholipid metabolites of HUVECs. Treatment with conditioned medium obtained from MDA-MB-231 cancer cells induced changes similar to the presence of growth factor supplements. These results suggest that cancer cells secrete growth factors and/or other molecules that influence the choline phospholipid metabolism of HUVECs. The ability of INDO to alter choline phospholipid metabolism in the presence of growth factor supplements suggests that the inflammatory response pathways of HUVECs may play a role in cancer cell-HUVEC interaction and in the response of HUVECs to growth factors.

Silencing p110β prevents rapid depletion of nuclear pAkt

International Nuclear Information System (INIS)

Ye, Zhi-wei; Ghalali, Aram; Högberg, Johan; Stenius, Ulla

2011-01-01

Highlights: ► p110β was essential for the statin- and ATP-induced depletion of nuclear pAkt and an associated inhibition of growth. ► p110β knock-out inhibited statin-induced changes in binding between FKBP51, pAkt and PTEN. ► Data supports the hypothesis that nuclear pAkt is important for anti-cancer effects of statins. -- Abstract: The p110β subunit in the class IA PI3K family may act as an oncogene and is critical for prostate tumor development in PTEN knockout mice. We tested the possible involvement of p110β in a recently described rapid depletion of phosphorylated Akt (pAkt) in the nucleus. Previous work showed that this down-regulation is induced by extracellular ATP or by statins and is mediated by the purinergic receptor P2X7. Here, we used p110β knock out mouse embryonic fibroblasts (MEFs) and siRNA-treated cancer cells. We found that p110β is essential for ATP- or statin-induced nuclear pAkt depletion in MEFs and in several cancer cell lines including prostate cancer cells. ATP, statin or the selective P2X7 agonist BzATP also inhibited cell growth, and this inhibition was not seen in p110β knock out cells. We also found that p110β was necessary for statin-induced changes in binding between FKBP51, pAkt and PTEN. Our data show that p110β is essential for the ATP- and statin-induced effects and support a role of nuclear pAkt in cancer development. They also provide support for a chemopreventive effect of statins mediated by depletion of nuclear pAkt.

Silencing p110{beta} prevents rapid depletion of nuclear pAkt

Energy Technology Data Exchange (ETDEWEB)

Ye, Zhi-wei; Ghalali, Aram; Hoegberg, Johan [Institute of Environmental Medicine, Karolinska Institutet, S-17177 Stockholm (Sweden); Stenius, Ulla, E-mail: ulla.stenius@ki.se [Institute of Environmental Medicine, Karolinska Institutet, S-17177 Stockholm (Sweden)

2011-12-02

Highlights: Black-Right-Pointing-Pointer p110{beta} was essential for the statin- and ATP-induced depletion of nuclear pAkt and an associated inhibition of growth. Black-Right-Pointing-Pointer p110{beta} knock-out inhibited statin-induced changes in binding between FKBP51, pAkt and PTEN. Black-Right-Pointing-Pointer Data supports the hypothesis that nuclear pAkt is important for anti-cancer effects of statins. -- Abstract: The p110{beta} subunit in the class IA PI3K family may act as an oncogene and is critical for prostate tumor development in PTEN knockout mice. We tested the possible involvement of p110{beta} in a recently described rapid depletion of phosphorylated Akt (pAkt) in the nucleus. Previous work showed that this down-regulation is induced by extracellular ATP or by statins and is mediated by the purinergic receptor P2X7. Here, we used p110{beta} knock out mouse embryonic fibroblasts (MEFs) and siRNA-treated cancer cells. We found that p110{beta} is essential for ATP- or statin-induced nuclear pAkt depletion in MEFs and in several cancer cell lines including prostate cancer cells. ATP, statin or the selective P2X7 agonist BzATP also inhibited cell growth, and this inhibition was not seen in p110{beta} knock out cells. We also found that p110{beta} was necessary for statin-induced changes in binding between FKBP51, pAkt and PTEN. Our data show that p110{beta} is essential for the ATP- and statin-induced effects and support a role of nuclear pAkt in cancer development. They also provide support for a chemopreventive effect of statins mediated by depletion of nuclear pAkt.

Effects of T cell depletion in radiation bone marrow chimeras. II. Requirement for allogeneic T cells in the reconstituting bone marrow inoculum for subsequent resistance to breaking of tolerance

International Nuclear Information System (INIS)

Sykes, M.; Sheard, M.A.; Sachs, D.H.

1988-01-01

The ability of normal recipient-type lymphocytes to break tolerance in long-term allogenic radiation chimeras has been investigated. Reconstitution of lethally irradiated mice with a mixture of syngeneic and allogeneic T cell-depleted (TCD) bone marrow (BM) has previously been shown to lead to mixed chimerism and permanent, specific tolerance to donor and host alloantigen (3-5). If allogeneic T cells are not depleted from the reconstituting inoculum, complete allogeneic chimerism results; however, no clinical evidence for GVHD is observed, presumably due to the protective effect provided by syngeneic TCD BM. This model has now been used to study the effects of allogenic T cells administered in reconstituting BM inocula on stability of long-term tolerance. We have attempted to break tolerance in long-term chimeras originally reconstituted with TCD or non-TCD BM by challenging them with inocula containing normal, nontolerant recipient strain lymphocytes. tolerance was broken with remarkable ease in recipients of mixed marrow inocula in which both original BM components were TCD. In contrast, tolerance in chimeras originally reconstituted with non-TCD allogeneic BM was not affected by such inocula. Susceptibility to loss of chimerism and tolerance was not related to initial levels of chimerism per se, but rather to T cell depletion of allogeneic BM, since chimeras reconstituted with TCD allogeneic BM alone (mean level of allogeneic chimerism 98%) were as susceptible as mixed chimeras to the tolerance-breaking effects of such inocula. The possible contribution of GVH reactivity to this resistance was investigated using an F1 into parent strain combination. In these animals, the use of non-TCD F1 BM inocula for reconstitution did not lead to resistance to the tolerance-breaking effects of recipient strain splenocytes

Gene expression heterogeneities in embryonic stem cell populations

DEFF Research Database (Denmark)

Martinez Arias, Alfonso; Brickman, Joshua M

2011-01-01

Stem and progenitor cells are populations of cells that retain the capacity to populate specific lineages and to transit this capacity through cell division. However, attempts to define markers for stem cells have met with limited success. Here we consider whether this limited success reflects...... an intrinsic requirement for heterogeneity with stem cell populations. We focus on Embryonic Stem (ES) cells, in vitro derived cell lines from the early embryo that are considered both pluripotent (able to generate all the lineages of the future embryo) and indefinitely self renewing. We examine the relevance...... of recently reported heterogeneities in ES cells and whether these heterogeneities themselves are inherent requirements of functional potency and self renewal....

Bridging the Timescales of Single-Cell and Population Dynamics

Science.gov (United States)

Jafarpour, Farshid; Wright, Charles S.; Gudjonson, Herman; Riebling, Jedidiah; Dawson, Emma; Lo, Klevin; Fiebig, Aretha; Crosson, Sean; Dinner, Aaron R.; Iyer-Biswas, Srividya

2018-04-01

How are granular details of stochastic growth and division of individual cells reflected in smooth deterministic growth of population numbers? We provide an integrated, multiscale perspective of microbial growth dynamics by formulating a data-validated theoretical framework that accounts for observables at both single-cell and population scales. We derive exact analytical complete time-dependent solutions to cell-age distributions and population growth rates as functionals of the underlying interdivision time distributions, for symmetric and asymmetric cell division. These results provide insights into the surprising implications of stochastic single-cell dynamics for population growth. Using our results for asymmetric division, we deduce the time to transition from the reproductively quiescent (swarmer) to the replication-competent (stalked) stage of the Caulobacter crescentus life cycle. Remarkably, population numbers can spontaneously oscillate with time. We elucidate the physics leading to these population oscillations. For C. crescentus cells, we show that a simple measurement of the population growth rate, for a given growth condition, is sufficient to characterize the condition-specific cellular unit of time and, thus, yields the mean (single-cell) growth and division timescales, fluctuations in cell division times, the cell-age distribution, and the quiescence timescale.

Effect of acrolein and glutathione depleting agents on thioredoxin

International Nuclear Information System (INIS)

Yang Xianmei; Wu Xuli; Choi, Young Eun; Kern, Julie C.; Kehrer, James P.

2004-01-01

Acrolein is a widespread environmental pollutant that reacts rapidly with nucleophiles, especially cellular thiols. In addition to glutathione (GSH), thioredoxin (Trx) and thioredoxin reductase (TR) contain thiol groups and may react with electrophiles. In the present study, A549 cells treated with 5-25 μM acrolein for 30 min lost cellular Trx activity in a dose-dependent fashion. Over 90% of Trx activity was lost at concentrations of 25 μM or greater. In contrast, Trx protein content, as assessed by western blotting, was not altered immediately after the 30 min acrolein treatment. Both Trx activity and protein levels increased 4 h after the acrolein treatment. However, Trx activity remained below control levels at 24 h. A similar dose-response relationship was seen with TR in A549 cells exposed to acrolein. There was, however, a rapid recovery of TR activity such that it attained normal levels by 4 h after doses ≤75 μM acrolein. Diethyl maleate (DEM), a common but not highly specific, agent used to deplete GSH, also inactivated Trx. A 2 h exposure of A549 cells to 1 mM DEM depleted cellular GSH by ∼50% and diminished Trx activity by over 67%. Lower DEM doses (0.125 mM and 0.25 mM) for 1 h had no significant effect on GSH but significantly decreased Trx activity 12 and 23%, respectively. Similar to immediately after acrolein exposure, DEM did not affect Trx protein levels. A Trx-1-GFP fusion protein was transfected into A549 cells. While the fusion protein was expressed, the Trx component was inactive by the insulin reducing assay. In summary, Trx and TR are inactivated by acrolein. In addition, the GSH depleting agent DEM inactivates Trx somewhat more effectively than it depletes GSH. The Trx-1-GFP fusion protein, while readily expressed, appears to have little or no activity, perhaps because the small size of Trx-1 (12 kDa) is affected by the larger GFP

Protein-energy malnutrition halts hemopoietic progenitor cells in the G0/G1 cell cycle stage, thereby altering cell production rates

Directory of Open Access Journals (Sweden)

P. Borelli

2009-06-01

Full Text Available Protein energy malnutrition (PEM is a syndrome that often results in immunodeficiency coupled with pancytopenia. Hemopoietic tissue requires a high nutrient supply and the proliferation, differentiation and maturation of cells occur in a constant and balanced manner, sensitive to the demands of specific cell lineages and dependent on the stem cell population. In the present study, we evaluated the effect of PEM on some aspects of hemopoiesis, analyzing the cell cycle of bone marrow cells and the percentage of progenitor cells in the bone marrow. Two-month-old male Swiss mice (N = 7-9 per group were submitted to PEM with a low-protein diet (4% or were fed a control diet (20% protein ad libitum. When the experimental group had lost about 20% of their original body weight after 14 days, we collected blood and bone marrow cells to determine the percentage of progenitor cells and the number of cells in each phase of the cell cycle. Animals of both groups were stimulated with 5-fluorouracil. Blood analysis, bone marrow cell composition and cell cycle evaluation was performed after 10 days. Malnourished animals presented anemia, reticulocytopenia and leukopenia. Their bone marrow was hypocellular and depleted of progenitor cells. Malnourished animals also presented more cells than normal in phases G0 and G1 of the cell cycle. Thus, we conclude that PEM leads to the depletion of progenitor hemopoietic populations and changes in cellular development. We suggest that these changes are some of the primary causes of pancytopenia in cases of PEM.

Analysis of Vaginal Cell Populations during Experimental Vaginal Candidiasis

Science.gov (United States)

Fidel, Paul L.; Luo, Wei; Steele, Chad; Chabain, Joseph; Baker, Marc; Wormley, Floyd

1999-01-01

Studies with an estrogen-dependent murine model of vaginal candidiasis suggest that local cell-mediated immunity (CMI) is more important than systemic CMI for protection against vaginitis. The present study, however, showed that, compared to uninfected mice, little to no change in the percentage or types of vaginal T cells occurred during a primary vaginal infection or during a secondary vaginal infection where partial protection was observed. Furthermore, depletion of polymorphonuclear leukocytes (PMN) had no effect on infection in the presence or absence of pseudoestrus. These results indicate a lack of demonstrable effects by systemic CMI or PMN against vaginitis and suggest that if local T cells are important, they are functioning without showing significant increases in numbers within the vaginal mucosa during infection. PMID:10338532

CD44 staining of cancer stem-like cells is influenced by down-regulation of CD44 variant isoforms and up-regulation of the standard CD44 isoform in the population of cells that have undergone epithelial-to-mesenchymal transition.

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Adrian Biddle

Full Text Available CD44 is commonly used as a cell surface marker of cancer stem-like cells in epithelial tumours, and we have previously demonstrated the existence of two different CD44(high cancer stem-like cell populations in squamous cell carcinoma, one having undergone epithelial-to-mesenchymal transition and the other maintaining an epithelial phenotype. Alternative splicing of CD44 variant exons generates a great many isoforms, and it is not known which isoforms are expressed on the surface of the two different cancer stem-like cell phenotypes. Here, we demonstrate that cancer stem-like cells with an epithelial phenotype predominantly express isoforms containing the variant exons, whereas the cancer stem-like cells that have undergone an epithelial-to-mesenchymal transition down-regulate these variant isoforms and up-regulate expression of the standard CD44 isoform that contains no variant exons. In addition, we find that enzymatic treatments used to dissociate cells from tissue culture or fresh tumour specimens cause destruction of variant CD44 isoforms at the cell surface whereas expression of the standard CD44 isoform is preserved. This results in enrichment within the CD44(high population of cancer stem-like cells that have undergone an epithelial-to-mesenchymal transition and depletion from the CD44(high population of cancer stem-like cells that maintain an epithelial phenotype, and therefore greatly effects the characteristics of any cancer stem-like cell population isolated based on expression of CD44. As well as effecting the CD44(high population, enzymatic treatment also reduces the percentage of the total epithelial cancer cell population staining CD44-positive, with potential implications for studies that aim to use CD44-positive staining as a prognostic indicator. Analyses of the properties of cancer stem-like cells are largely dependent on the ability to accurately identify and assay these populations. It is therefore critical that

Achieving high-efficiency emission depletion nanoscopy by employing cross relaxation in upconversion nanoparticles.

Science.gov (United States)

Zhan, Qiuqiang; Liu, Haichun; Wang, Baoju; Wu, Qiusheng; Pu, Rui; Zhou, Chao; Huang, Bingru; Peng, Xingyun; Ågren, Hans; He, Sailing

2017-10-20

Stimulated emission depletion microscopy provides a powerful sub-diffraction imaging modality for life science studies. Conventionally, stimulated emission depletion requires a relatively high light intensity to obtain an adequate depletion efficiency through only light-matter interaction. Here we show efficient emission depletion for a class of lanthanide-doped upconversion nanoparticles with the assistance of interionic cross relaxation, which significantly lowers the laser intensity requirements of optical depletion. We demonstrate two-color super-resolution imaging using upconversion nanoparticles (resolution ~ 66 nm) with a single pair of excitation/depletion beams. In addition, we show super-resolution imaging of immunostained cytoskeleton structures of fixed cells (resolution ~ 82 nm) using upconversion nanoparticles. These achievements provide a new perspective for the development of photoswitchable luminescent probes and will broaden the applications of lanthanide-doped nanoparticles for sub-diffraction microscopic imaging.

Associative Interactions in Crowded Solutions of Biopolymers Counteract Depletion Effects.

Science.gov (United States)

Groen, Joost; Foschepoth, David; te Brinke, Esra; Boersma, Arnold J; Imamura, Hiromi; Rivas, Germán; Heus, Hans A; Huck, Wilhelm T S

2015-10-14

The cytosol of Escherichia coli is an extremely crowded environment, containing high concentrations of biopolymers which occupy 20-30% of the available volume. Such conditions are expected to yield depletion forces, which strongly promote macromolecular complexation. However, crowded macromolecule solutions, like the cytosol, are very prone to nonspecific associative interactions that can potentially counteract depletion. It remains unclear how the cytosol balances these opposing interactions. We used a FRET-based probe to systematically study depletion in vitro in different crowded environments, including a cytosolic mimic, E. coli lysate. We also studied bundle formation of FtsZ protofilaments under identical crowded conditions as a probe for depletion interactions at much larger overlap volumes of the probe molecule. The FRET probe showed a more compact conformation in synthetic crowding agents, suggesting strong depletion interactions. However, depletion was completely negated in cell lysate and other protein crowding agents, where the FRET probe even occupied slightly more volume. In contrast, bundle formation of FtsZ protofilaments proceeded as readily in E. coli lysate and other protein solutions as in synthetic crowding agents. Our experimental results and model suggest that, in crowded biopolymer solutions, associative interactions counterbalance depletion forces for small macromolecules. Furthermore, the net effects of macromolecular crowding will be dependent on both the size of the macromolecule and its associative interactions with the crowded background.

Dose-dependent ATP depletion and cancer cell death following calcium electroporation, relative effect of calcium concentration and electric field strength

DEFF Research Database (Denmark)

Hansen, Emilie Louise; Sozer, Esin Bengisu; Romeo, Stefania

2015-01-01

death and could be a novel cancer treatment. This study aims at understanding the relationship between applied electric field, calcium concentration, ATP depletion and efficacy. METHODS: In three human cell lines--H69 (small-cell lung cancer), SW780 (bladder cancer), and U937 (leukaemia), viability...... was observed with fluorescence confocal microscopy of quinacrine-labelled U937 cells. RESULTS: Both H69 and SW780 cells showed dose-dependent (calcium concentration and electric field) decrease in intracellular ATP (p...-dependently reduced cell survival and intracellular ATP. Increasing extracellular calcium allows the use of a lower electric field. GENERAL SIGNIFICANCE: This study supports the use of calcium electroporation for treatment of cancer and possibly lowering the applied electric field in future trials....

On interfaces between cell populations with different mobilities

KAUST Repository

Lorenzi, Tommaso

2016-11-18

Partial differential equations describing the dynamics of cell population densities from a fluid mechanical perspective can model the growth of avascular tumours. In this framework, we consider a system of equations that describes the interaction between a population of dividing cells and a population of non-dividing cells. The two cell populations are characterised by different mobilities. We present the results of numerical simulations displaying two-dimensional spherical waves with sharp interfaces between dividing and non-dividing cells. Furthermore, we numerically observe how different ratios between the mobilities change the morphology of the interfaces, and lead to the emergence of finger-like patterns of invasion above a threshold. Motivated by these simulations, we study the existence of one-dimensional travelling wave solutions.

Antisickling effects of 2,3-diphosphoglycerate depletion.

Science.gov (United States)

Poillon, W N; Kim, B C; Labotka, R J; Hicks, C U; Kark, J A

1995-06-01

Elevation of 2,3-bisphosphoglycerate (2,3-DPG) in sickle erthrocytes (SS RBCs) and concomitant acidification of the cell interior promote polymerization by decreasing the solubility (csat) of deoxyhemoglobin S. The antisickling effect of 2,3-DPG depletion was evaluated after activation of the 2,3-DPG phosphatase activity of bisphosphoglycerate mutase by glycolate-2-phosphate, leading to rapid loss of intracellular 2,3-DPG. To ensure its maximal reduction in a physiologic medium, isosmotic CO2/bicarbonate-buffered saline, pH 7.0, was used. Substitution of K+ for Na+ as the major extracellular cation suppressed K:Cl cotransport, prevented cell shrinkage, and allowed demonstration of the full antisickling effect of 2,3-DPG depletion. The modest effect on solubility per se of removing intraerythrocytic 2,3-DPG (delta Csat = 1.6 g/dL) was amplified into a much larger antisickling effect by interaction with three other cellular variables affecting solubility and polymer content (intracellular pH, O2 saturation, and mean cell hemoglobin concentration). Acting in concert, these four antisickling effects (three solubilizing, one osmotic) reduced polymer fraction of glycolate-treated SS RBCs by 32% to 63%, with a concomitant decrease in sickling of 46% to 95% at the nominal pO2 of the microcirculation (20 mm Hg). A decrement in sickling of this magnitude should significantly ameliorate the vasoocclusive severity of sickle cell disease.

Improved survival of acute lymphoblastic leukemia patients of HLA-A3/11 absent for donor KIR3DL2 after non-T-cell depleted HLA-identical sibling hematopoietic stem cells transplantation

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farhad shahsavar

2011-08-01

Conclusion: These data indicate that the absence of HLA class I ligand in the recipient for donor-inhibitory KIR can be a prognostic factor for transplantation outcomes in non-T-cell depleted HLA-identical sibling hematopoietic stem-cell transplantation and that the lack of HLA-A3/11 for donor KIR3DL2 can contribute to improved survival for patients with ALL.

Depletion region surface effects in electron beam induced current measurements

Energy Technology Data Exchange (ETDEWEB)

Haney, Paul M.; Zhitenev, Nikolai B. [Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Yoon, Heayoung P. [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States); Gaury, Benoit [Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Maryland NanoCenter, University of Maryland, College Park, Maryland 20742 (United States)

2016-09-07

Electron beam induced current (EBIC) is a powerful characterization technique which offers the high spatial resolution needed to study polycrystalline solar cells. Current models of EBIC assume that excitations in the p-n junction depletion region result in perfect charge collection efficiency. However, we find that in CdTe and Si samples prepared by focused ion beam (FIB) milling, there is a reduced and nonuniform EBIC lineshape for excitations in the depletion region. Motivated by this, we present a model of the EBIC response for excitations in the depletion region which includes the effects of surface recombination from both charge-neutral and charged surfaces. For neutral surfaces, we present a simple analytical formula which describes the numerical data well, while the charged surface response depends qualitatively on the location of the surface Fermi level relative to the bulk Fermi level. We find that the experimental data on FIB-prepared Si solar cells are most consistent with a charged surface and discuss the implications for EBIC experiments on polycrystalline materials.

GTP depletion synergizes the anti-proliferative activity of chemotherapeutic agents in a cell type-dependent manner

International Nuclear Information System (INIS)

Lin, Tao; Meng, Lingjun; Tsai, Robert Y.L.

2011-01-01

Highlights: → Strong synergy between mycophenolic acid (MPA) and 5-FU in MDA-MB-231 cells. → Cell type-dependent synergy between MPA and anti-proliferative agents. → The synergy of MPA on 5-FU is recapitulated by RNA polymerase-I inhibition. → The synergy of MPA on 5-FU requires the expression of nucleostemin. -- Abstract: Mycophenolic acid (MPA) depletes intracellular GTP by blocking de novo guanine nucleotide synthesis. GTP is used ubiquitously for DNA/RNA synthesis and as a signaling molecule. Here, we made a surprising discovery that the anti-proliferative activity of MPA acts synergistically with specific chemotherapeutic agents in a cell type-dependent manner. In MDA-MB-231 cells, MPA shows an extremely potent synergy with 5-FU but not with doxorubicin or etoposide. The synergy between 5-FU and MPA works most effectively against the highly tumorigenic mammary tumor cells compared to the less tumorigenic ones, and does not work in the non-breast cancer cell types that we tested, with the exception of PC3 cells. On the contrary, MPA shows the highest synergy with paclitaxel but not with 5-FU in SCC-25 cells, derived from oral squamous cell carcinomas. Mechanistically, the synergistic effect of MPA on 5-FU in MDA-MB-231 cells can be recapitulated by inhibiting the RNA polymerase-I activity and requires the expression of nucleostemin. This work reveals that the synergy between MPA and anti-proliferative agents is determined by cell type-dependent factors.

Effects of adenine nucleotide and sterol depletion on tight junction structure and function in MDCK cells

International Nuclear Information System (INIS)

Ladino, C.A.

1988-01-01

The antitumor agent Hadacidin (H), N-formyl-hydroxyamino-acetic acid, reversibly inhibited the multiplication of clone 4 Madin-Darby canine kidney (MDCK) cells at a 4 mM concentration within 24-48 hours. Treated cells were arrested in the S phase of the cell cycle. Accompanying this action was a 16-fold increase in the area occupied b the cells and a refractoriness to trypsin treatment. To test whether this effect was due to an increase in tight junction integrity, electrical resistance (TER) was measured across H-treated monolayers. Addition of H at the onset of junction formation reversibly prevented the development of TER. ATP and cAMP levels were decreased by H, as well as the rate of [ 3 H]-leucine incorporation into protein. When 1 mM dibutyryl-cAMP (d.cAMP) and theophylline were added, H had no effect on cell division or protein synthesis, and TER was partially restored. The addition of 1 mM d.cAMP and 1 mM theophylline to control cultures decreased TER, indicating a biphasic effect on TER development/maintenance. In a separate study, the effect of sterol depletion on tight junctions formation/maintenance in wild-type MDCK cells was investigated

New avenues in hypoxic cell sensitization

International Nuclear Information System (INIS)

Huilgol, N.G.; Chatterjee, N.A.; Singh, B.B.

1995-01-01

Hypoxic cells in tumors represent a population of cells that are resistant to radiotherapy. Bio-reductive agents like RSU 1069, RBU 6145 and EOg and vasoactive drugs in conjunction with hypoxic cell sensitizers are being evaluated as hypoxic cell cytotoxins. Chlorpromazine a membrane active drug and AK-2123- a nitrotriazole with a potential to deplete intracellular thiols induced vasoconstriction and sensitize hypoxic cells have stretched the boundaries of innovation. A preliminary experience with these drugs is discussed. 8 refs., 2 tabs., 2 figs

Characterization of a resident population of adventitial macrophage progenitor cells in postnatal vasculature.

Science.gov (United States)

Psaltis, Peter J; Puranik, Amrutesh S; Spoon, Daniel B; Chue, Colin D; Hoffman, Scott J; Witt, Tyra A; Delacroix, Sinny; Kleppe, Laurel S; Mueske, Cheryl S; Pan, Shuchong; Gulati, Rajiv; Simari, Robert D

2014-07-18

Macrophages regulate blood vessel structure and function in health and disease. The origins of tissue macrophages are diverse, with evidence for local production and circulatory renewal. We identified a vascular adventitial population containing macrophage progenitor cells and investigated their origins and fate. Single-cell disaggregates from adult C57BL/6 mice were prepared from different tissues and tested for their capacity to form hematopoietic colony-forming units. Aorta showed a unique predilection for generating macrophage colony-forming units. Aortic macrophage colony-forming unit progenitors coexpressed stem cell antigen-1 and CD45 and were adventitially located, where they were the predominant source of proliferating cells in the aortic wall. Aortic Sca-1(+)CD45(+) cells were transcriptionally and phenotypically distinct from neighboring cells lacking stem cell antigen-1 or CD45 and contained a proliferative (Ki67(+)) Lin(-)c-Kit(+)CD135(-)CD115(+)CX3CR1(+)Ly6C(+)CD11b(-) subpopulation, consistent with the immunophenotypic profile of macrophage progenitors. Adoptive transfer studies revealed that Sca-1(+)CD45(+) adventitial macrophage progenitor cells were not replenished via the circulation from bone marrow or spleen, nor was their prevalence diminished by depletion of monocytes or macrophages by liposomal clodronate treatment or genetic deficiency of macrophage colony-stimulating factor. Rather adventitial macrophage progenitor cells were upregulated in hyperlipidemic ApoE(-/-) and LDL-R(-/-) mice, with adventitial transfer experiments demonstrating their durable contribution to macrophage progeny particularly in the adventitia, and to a lesser extent the atheroma, of atherosclerotic carotid arteries. The discovery and characterization of resident vascular adventitial macrophage progenitor cells provides new insight into adventitial biology and its participation in atherosclerosis and provokes consideration of the broader existence of local macrophage

Evidence for the re-establishment of a heterogeneity in radiosensitivity among spermatogonial stem cells repopulating the mouse testis following depletion by X-rays

International Nuclear Information System (INIS)

Cattanach, B.M.; Barlow, J.H.

1984-01-01

Earlier studies have shown that the spermatogonial stem cells of the mouse testis recovering from previous radiation or chemical mutagen exposure give subnormal yields of genetic damage with subsequent X-irradiation. This response has been investigated further: (a) with a high, 9-Gy X-ray dose given 4, 12 or 21 days after a 1-Gy conditioning dose and (b) with a 1 + 7-Gy, 24-h fractionation regime given 4 or 14 days after a 1-Gy conditioning dose. The results of the experiments suggest that a heterogeneity in radiosensitivity, such as exists in unirradiated stem cell populations and absent 24-48 h after radiation depletion, is quickly re-established among the stem cells repopulating the testis. And that the newly established heterogeneity is removed by the second 1-Gy conditioning dose. With longer intervals between treatments, genetic yields consistent with additivity were obtained in Expt. 1; less clear results were obtained in Expt. 2. Comparison with earlier data generally suggested that the duration of the repopulating period is dose-dependent. In a third experiment evidence was obtained that genetic damage induced by X-irradiation can be reduced by a subsequent treatment with triethylenemelamine (TEM) during the repopulating phase. This confirmed an earlier finding. Such an interaction could not be demonstrated with two X-ray treatments. An explanation for the X-ray/TEM interaction is offered. (Auth.)

Deconstructing stem cell population heterogeneity: Single-cell analysis and modeling approaches

Science.gov (United States)

Wu, Jincheng; Tzanakakis, Emmanuel S.

2014-01-01

Isogenic stem cell populations display cell-to-cell variations in a multitude of attributes including gene or protein expression, epigenetic state, morphology, proliferation and proclivity for differentiation. The origins of the observed heterogeneity and its roles in the maintenance of pluripotency and the lineage specification of stem cells remain unclear. Addressing pertinent questions will require the employment of single-cell analysis methods as traditional cell biochemical and biomolecular assays yield mostly population-average data. In addition to time-lapse microscopy and flow cytometry, recent advances in single-cell genomic, transcriptomic and proteomic profiling are reviewed. The application of multiple displacement amplification, next generation sequencing, mass cytometry and spectrometry to stem cell systems is expected to provide a wealth of information affording unprecedented levels of multiparametric characterization of cell ensembles under defined conditions promoting pluripotency or commitment. Establishing connections between single-cell analysis information and the observed phenotypes will also require suitable mathematical models. Stem cell self-renewal and differentiation are orchestrated by the coordinated regulation of subcellular, intercellular and niche-wide processes spanning multiple time scales. Here, we discuss different modeling approaches and challenges arising from their application to stem cell populations. Integrating single-cell analysis with computational methods will fill gaps in our knowledge about the functions of heterogeneity in stem cell physiology. This combination will also aid the rational design of efficient differentiation and reprogramming strategies as well as bioprocesses for the production of clinically valuable stem cell derivatives. PMID:24035899

Identification of a murine CD45-F4/80lo HSC-derived marrow endosteal cell associated with donor stem cell engraftment.

Science.gov (United States)

Overholt, Kathleen M; Otsuru, Satoru; Olson, Timothy S; Guess, Adam J; Velazquez, Victoria M; Desbourdes, Laura; Dominici, Massimo; Horwitz, Edwin M

2017-12-26

Hematopoietic stem cells (HSCs) reside in specialized microenvironments within the marrow designated as stem cell niches, which function to support HSCs at homeostasis and promote HSC engraftment after radioablation. We previously identified marrow space remodeling after hematopoietic ablation, including osteoblast thickening, osteoblast proliferation, and megakaryocyte migration to the endosteum, which is critical for effective engraftment of donor HSCs. To further evaluate the impact of hematopoietic cells on marrow remodeling, we used a transgenic mouse model (CD45Cre/iDTR) to selectively deplete hematopoietic cells in situ. Depletion of hematopoietic cells immediately before radioablation and hematopoietic stem cell transplantation abrogated donor HSC engraftment and was associated with strikingly flattened endosteal osteoblasts with preserved osteoblast proliferation and megakaryocyte migration. Depletion of monocytes, macrophages, or megakaryocytes (the predominant hematopoietic cell populations that survive short-term after irradiation) did not lead to an alteration of osteoblast morphology, suggesting that a hematopoietic-derived cell outside these lineages regulates osteoblast morphologic adaptation after irradiation. Using 2 lineage-tracing strategies, we identified a novel CD45 - F4/80 lo HSC-derived cell that resides among osteoblasts along the endosteal marrow surface and, at least transiently, survives radioablation. This newly identified marrow cell may be an important regulator of HSC engraftment, possibly by influencing the shape and function of endosteal osteoblasts.

Relationship between the ability of sunscreens containing 2-ethylhexyl-4'-methoxycinnamate to protect against UVR-induced inflammation, depletion of epidermal Langerhans (Ia+) cells and suppression of alloactivating capacity of murine skin in vivo.

Science.gov (United States)

Walker, S L; Morris, J; Chu, A C; Young, A R

1994-01-01

The UVB sunscreen 2-ethylhexyl-4'-methoxycinnamate was evaluated in hairless albino mouse skin for its ability to inhibit UVR-induced (i) oedema, (ii) epidermal Langerhans cell (Ia+) depletion and (iii) suppression of the alloactivating capacity of epidermal cells (mixed epidermal cell-lymphocyte reaction, MECLR). The sunscreen, prepared at 9% in ethanol or a cosmetic lotion, was applied prior to UVB/UVA irradiation. In some experiments there was a second application halfway through the irradiation. Single applications in both vehicles gave varying degrees of protection from oedema and Langerhans cell depletion but afforded no protection from suppression of MECLR. When the sunscreens were applied twice there was improved protection from oedema and Langerhans cell depletion and complete protection was afforded from suppression of MECLR. There was a clear linear relationship between Langerhans cell numbers and oedema with and without sunscreen application. The relationship between Langerhans cell numbers and MECLR was more complex. These data confirm published discrepancies between protection from oedema (a model for human erythema) and endpoints with immunological significance, but show that 2-ethylhexyl-4'-methoxycinnamate can afford complete immunoprotection, although protection is dependent on the application rate and vehicle.

Neural Differentiation in HDAC1-Depleted Cells Is Accompanied by Coilin Downregulation and the Accumulation of Cajal Bodies in Nucleoli.

Science.gov (United States)

Krejčí, Jana; Legartová, Soňa; Bártová, Eva

2017-01-01

Cajal bodies (CBs) are important compartments containing accumulated proteins that preferentially regulate RNA-related nuclear events, including splicing. Here, we studied the nuclear distribution pattern of CBs in neurogenesis. In adult brains, coilin was present at a high density, but CB formation was absent in the nuclei of the choroid plexus of the lateral ventricles. Cells of the adult hippocampus were characterized by a crescent-like morphology of coilin protein. We additionally observed a 70 kDa splice variant of coilin in adult mouse brains, which was different to embryonic brains and mouse pluripotent embryonic stem cells (mESCs), characterized by the 80 kDa standard variant of coilin. Here, we also showed that depletion of coilin is induced during neural differentiation and HDAC1 deficiency in mESCs caused coilin accumulation inside the fibrillarin-positive region of the nucleoli. A similar distribution pattern was observed in adult brain hippocampi, characterized by lower levels of both coilin and HDAC1. In summary, we observed that neural differentiation and HDAC1 deficiency lead to coilin depletion and coilin accumulation in body-like structures inside the nucleoli.

"When the going gets tough, who keeps going?" Depletion sensitivity moderates the ego-depletion effect

NARCIS (Netherlands)

Salmon, Stefanie J.; Adriaanse, Marieke A.; De Vet, Emely; Fennis, Bob M.; De Ridder, Denise T D

2014-01-01

Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In

"When the going gets tough, who keeps going?" : Depletion sensitivity moderates the ego-depletion effect

NARCIS (Netherlands)

Salmon, Stefanie J.; Adriaanse, Marieke A.; De Vet, Emely; Fennis, Bob M.; De Ridder, Denise T. D.

2014-01-01

Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In

The modality effect of ego depletion: Auditory task modality reduces ego depletion.

Science.gov (United States)

Li, Qiong; Wang, Zhenhong

2016-08-01

An initial act of self-control that impairs subsequent acts of self-control is called ego depletion. The ego depletion phenomenon has been observed consistently. The modality effect refers to the effect of the presentation modality on the processing of stimuli. The modality effect was also robustly found in a large body of research. However, no study to date has examined the modality effects of ego depletion. This issue was addressed in the current study. In Experiment 1, after all participants completed a handgrip task, one group's participants completed a visual attention regulation task and the other group's participants completed an auditory attention regulation task, and then all participants again completed a handgrip task. The ego depletion phenomenon was observed in both the visual and the auditory attention regulation task. Moreover, participants who completed the visual task performed worse on the handgrip task than participants who completed the auditory task, which indicated that there was high ego depletion in the visual task condition. In Experiment 2, participants completed an initial task that either did or did not deplete self-control resources, and then they completed a second visual or auditory attention control task. The results indicated that depleted participants performed better on the auditory attention control task than the visual attention control task. These findings suggest that altering task modality may reduce ego depletion. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

The Toxicity of Depleted Uranium

Directory of Open Access Journals (Sweden)

Wayne Briner

2010-01-01

Full Text Available Depleted uranium (DU is an emerging environmental pollutant that is introduced into the environment primarily by military activity. While depleted uranium is less radioactive than natural uranium, it still retains all the chemical toxicity associated with the original element. In large doses the kidney is the target organ for the acute chemical toxicity of this metal, producing potentially lethal tubular necrosis. In contrast, chronic low dose exposure to depleted uranium may not produce a clear and defined set of symptoms. Chronic low-dose, or subacute, exposure to depleted uranium alters the appearance of milestones in developing organisms. Adult animals that were exposed to depleted uranium during development display persistent alterations in behavior, even after cessation of depleted uranium exposure. Adult animals exposed to depleted uranium demonstrate altered behaviors and a variety of alterations to brain chemistry. Despite its reduced level of radioactivity evidence continues to accumulate that depleted uranium, if ingested, may pose a radiologic hazard. The current state of knowledge concerning DU is discussed.

ATP depletion during mitotic arrest induces mitotic slippage and APC/CCdh1-dependent cyclin B1 degradation.

Science.gov (United States)

Park, Yun Yeon; Ahn, Ju-Hyun; Cho, Min-Guk; Lee, Jae-Ho

2018-04-27

ATP depletion inhibits cell cycle progression, especially during the G1 phase and the G2 to M transition. However, the effect of ATP depletion on mitotic progression remains unclear. We observed that the reduction of ATP after prometaphase by simultaneous treatment with 2-deoxyglucose and NaN 3 did not arrest mitotic progression. Interestingly, ATP depletion during nocodazole-induced prometaphase arrest resulted in mitotic slippage, as indicated by a reduction in mitotic cells, APC/C-dependent degradation of cyclin B1, increased cell attachment, and increased nuclear membrane reassembly. Additionally, cells successfully progressed through the cell cycle after mitotic slippage, as indicated by EdU incorporation and time-lapse imaging. Although degradation of cyclin B during normal mitotic progression is primarily regulated by APC/C Cdc20 , we observed an unexpected decrease in Cdc20 prior to degradation of cyclin B during mitotic slippage. This decrease in Cdc20 was followed by a change in the binding partner preference of APC/C from Cdc20 to Cdh1; consequently, APC/C Cdh1 , but not APC/C Cdc20 , facilitated cyclin B degradation following ATP depletion. Pulse-chase analysis revealed that ATP depletion significantly abrogated global translation, including the translation of Cdc20 and Cdh1. Additionally, the half-life of Cdh1 was much longer than that of Cdc20. These data suggest that ATP depletion during mitotic arrest induces mitotic slippage facilitated by APC/C Cdh1 -dependent cyclin B degradation, which follows a decrease in Cdc20 resulting from reduced global translation and the differences in the half-lives of the Cdc20 and Cdh1 proteins.

Health and environmental impact of depleted uranium

International Nuclear Information System (INIS)

Furitsu, Katsumi

2010-01-01

Depleted Uranium (DU) is 'nuclear waste' produced from the enrichment process and is mostly made up of 238 U and is depleted in the fissionable isotope 235 U compared to natural uranium (NU). Depleted uranium has about 60% of the radioactivity of natural uranium. Depleted uranium and natural uranium are identical in terms of the chemical toxicity. Uranium's high density gives depleted uranium shells increased range and penetrative power. This density, combined with uranium's pyrophoric nature, results in a high-energy kinetic weapon that can punch and burn through armour plating. Striking a hard target, depleted uranium munitions create extremely high temperatures. The uranium immediately burns and vaporizes into an aerosol, which is easily diffused in the environment. People can inhale the micro-particles of uranium oxide in an aerosol and absorb them mainly from lung. Depleted uranium has both aspects of radiological toxicity and chemical toxicity. The possible synergistic effect of both kinds of toxicities is also pointed out. Animal and cellular studies have been reported the carcinogenic, neurotoxic, immuno-toxic and some other effects of depleted uranium including the damage on reproductive system and foetus. In addition, the health effects of micro/ nano-particles, similar in size of depleted uranium aerosols produced by uranium weapons, have been reported. Aerosolized DU dust can easily spread over the battlefield spreading over civilian areas, sometimes even crossing international borders. Therefore, not only the military personnel but also the civilians can be exposed. The contamination continues after the cessation of hostilities. Taking these aspects into account, DU weapon is illegal under international humanitarian laws and is considered as one of the inhumane weapons of 'indiscriminate destruction'. The international society is now discussing the prohibition of DU weapons based on 'precautionary principle'. The 1991 Gulf War is reportedly the first

Issues in Stratospheric Ozone Depletion.

Science.gov (United States)

Lloyd, Steven Andrew

Following the announcement of the discovery of the Antarctic ozone hole in 1985 there have arisen a multitude of questions pertaining to the nature and consequences of polar ozone depletion. This thesis addresses several of these specific questions, using both computer models of chemical kinetics and the Earth's radiation field as well as laboratory kinetic experiments. A coupled chemical kinetic-radiative numerical model was developed to assist in the analysis of in situ field measurements of several radical and neutral species in the polar and mid-latitude lower stratosphere. Modeling was used in the analysis of enhanced polar ClO, mid-latitude diurnal variation of ClO, and simultaneous measurements of OH, HO_2, H_2 O and O_3. Most importantly, such modeling was instrumental in establishing the link between the observed ClO and BrO concentrations in the Antarctic polar vortex and the observed rate of ozone depletion. The principal medical concern of stratospheric ozone depletion is that ozone loss will lead to the enhancement of ground-level UV-B radiation. Global ozone climatology (40^circS to 50^ circN latitude) was incorporated into a radiation field model to calculate the biologically accumulated dosage (BAD) of UV-B radiation, integrated over days, months, and years. The slope of the annual BAD as a function of latitude was found to correspond to epidemiological data for non-melanoma skin cancers for 30^circ -50^circN. Various ozone loss scenarios were investigated. It was found that a small ozone loss in the tropics can provide as much additional biologically effective UV-B as a much larger ozone loss at higher latitudes. Also, for ozone depletions of > 5%, the BAD of UV-B increases exponentially with decreasing ozone levels. An important key player in determining whether polar ozone depletion can propagate into the populated mid-latitudes is chlorine nitrate, ClONO_2 . As yet this molecule is only indirectly accounted for in computer models and field

Trypanosoma brucei Co-opts NK Cells to Kill Splenic B2 B Cells.

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Deborah Frenkel

2016-07-01

Full Text Available After infection with T. brucei AnTat 1.1, C57BL/6 mice lost splenic B2 B cells and lymphoid follicles, developed poor parasite-specific antibody responses, lost weight, became anemic and died with fulminating parasitemia within 35 days. In contrast, infected C57BL/6 mice lacking the cytotoxic granule pore-forming protein perforin (Prf1-/- retained splenic B2 B cells and lymphoid follicles, developed high-titer antibody responses against many trypanosome polypeptides, rapidly suppressed parasitemia and did not develop anemia or lose weight for at least 60 days. Several lines of evidence show that T. brucei infection-induced splenic B cell depletion results from natural killer (NK cell-mediated cytotoxicity: i B2 B cells were depleted from the spleens of infected intact, T cell deficient (TCR-/- and FcγRIIIa deficient (CD16-/- C57BL/6 mice excluding a requirement for T cells, NKT cell, or antibody-dependent cell-mediated cytotoxicity; ii administration of NK1.1 specific IgG2a (mAb PK136 but not irrelevant IgG2a (myeloma M9144 prevented infection-induced B cell depletion consistent with a requirement for NK cells; iii splenic NK cells but not T cells or NKT cells degranulated in infected C57BL/6 mice co-incident with B cell depletion evidenced by increased surface expression of CD107a; iv purified NK cells from naïve C57BL/6 mice killed purified splenic B cells from T. brucei infected but not uninfected mice in vitro indicating acquisition of an NK cell activating phenotype by the post-infection B cells; v adoptively transferred C57BL/6 NK cells prevented infection-induced B cell population growth in infected Prf1-/- mice consistent with in vivo B cell killing; vi degranulated NK cells in infected mice had altered gene and differentiation antigen expression and lost cytotoxic activity consistent with functional exhaustion, but increased in number as infection progressed indicating continued generation. We conclude that NK cells in T. brucei

NK Cells and Other Innate Lymphoid Cells in Hematopoietic Stem Cell Transplantation.

Science.gov (United States)

Vacca, Paola; Montaldo, Elisa; Croxatto, Daniele; Moretta, Francesca; Bertaina, Alice; Vitale, Chiara; Locatelli, Franco; Mingari, Maria Cristina; Moretta, Lorenzo

2016-01-01

Natural killer (NK) cells play a major role in the T-cell depleted haploidentical hematopoietic stem cell transplantation (haplo-HSCT) to cure high-risk leukemias. NK cells belong to the expanding family of innate lymphoid cells (ILCs). At variance with NK cells, the other ILC populations (ILC1/2/3) are non-cytolytic, while they secrete different patterns of cytokines. ILCs provide host defenses against viruses, bacteria, and parasites, drive lymphoid organogenesis, and contribute to tissue remodeling. In haplo-HSCT patients, the extensive T-cell depletion is required to prevent graft-versus-host disease (GvHD) but increases risks of developing a wide range of life-threatening infections. However, these patients may rely on innate defenses that are reconstituted more rapidly than the adaptive ones. In this context, ILCs may represent important players in the early phases following transplantation. They may contribute to tissue homeostasis/remodeling and lymphoid tissue reconstitution. While the reconstitution of NK cell repertoire and its role in haplo-HSCT have been largely investigated, little information is available on ILCs. Of note, CD34(+) cells isolated from different sources of HSC may differentiate in vitro toward various ILC subsets. Moreover, cytokines released from leukemia blasts (e.g., IL-1β) may alter the proportions of NK cells and ILC3, suggesting the possibility that leukemia may skew the ILC repertoire. Further studies are required to define the timing of ILC development and their potential protective role after HSCT.

NK cells and other innate lymphoid cells in haematopoietic stem cell transplantation

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Paola eVacca

2016-05-01

Full Text Available Natural Killer (NK cells play a major role in the T-cell depleted haploidentical haematopoietic stem cell transplantation (haplo-HSCT to cure high-risk leukemias. NK cells belong to the expanding family of innate lymphoid cells (ILC. At variance with NK cells, the other ILC populations (ILC1/2/3 are non-cytolytic, while they secrete different patterns of cytokines. ILC provide host defences against viruses, bacteria and parasites, drive lymphoid organogenesis, and contribute to tissue remodelling. In haplo-HSCT patients, the extensive T-cell depletion is required to prevent graft-versus-host disease (GvHD but increases risks of developing a wide range of life-threatening infections. However, these patients may rely on innate defences that are reconstituted more rapidly than the adaptive ones. In this context, ILC may represent important players in the early phases following transplantation. They may contribute to tissue homeostasis/remodelling and lymphoid tissue reconstitution. While the reconstitution of NK cell repertoire and its role in haplo-HSCT have been largely investigated, little information is available on ILC. Of note, CD34+ cells isolated from different sources of HSC, may differentiate in vitro towards various ILC subsets. Moreover, cytokines released from leukemia blasts (e.g. IL-1β may alter the proportions of NK cells and ILC3, suggesting the possibility that leukemia may skew the ILC repertoire. Further studies are required to define the timing of ILC development and their potential protective role after HSCT.

Management of depleted uranium

International Nuclear Information System (INIS)

2001-01-01

Large stocks of depleted uranium have arisen as a result of enrichment operations, especially in the United States and the Russian Federation. Countries with depleted uranium stocks are interested in assessing strategies for the use and management of depleted uranium. The choice of strategy depends on several factors, including government and business policy, alternative uses available, the economic value of the material, regulatory aspects and disposal options, and international market developments in the nuclear fuel cycle. This report presents the results of a depleted uranium study conducted by an expert group organised jointly by the OECD Nuclear Energy Agency and the International Atomic Energy Agency. It contains information on current inventories of depleted uranium, potential future arisings, long term management alternatives, peaceful use options and country programmes. In addition, it explores ideas for international collaboration and identifies key issues for governments and policy makers to consider. (authors)

Comparative Analysis of VERA Depletion Problems

International Nuclear Information System (INIS)

Park, Jinsu; Kim, Wonkyeong; Choi, Sooyoung; Lee, Hyunsuk; Lee, Deokjung

2016-01-01

Each code has its own solver for depletion, which can produce different depletion calculation results. In order to produce reference solutions for depletion calculation comparison, sensitivity studies should be preceded for each depletion solver. The sensitivity tests for burnup interval, number of depletion zones, and recoverable energy per fission (Q-value) were performed in this paper. For the comparison of depletion calculation results, usually the multiplication factors are compared as a function of burnup. In this study, new comparison methods have been introduced by using the number density of isotope or element, and a cumulative flux instead of burnup. In this paper, optimum depletion calculation options are determined through the sensitivity study of the burnup intervals and the number of depletion intrazones. Because the depletion using CRAM solver performs well for large burnup intervals, smaller number of burnup steps can be used to produce converged solutions. It was noted that the depletion intra-zone sensitivity is only pin-type dependent. The 1 and 10 depletion intra-zones for the normal UO2 pin and gadolinia rod, respectively, are required to obtain the reference solutions. When the optimized depletion calculation options are used, the differences of Q-values are found to be a main cause of the differences of solutions. In this paper, new comparison methods were introduced for consistent code-to-code comparisons even when different kappa libraries were used in the depletion calculations

Functional cure of SIVagm infection in rhesus macaques results in complete recovery of CD4+ T cells and is reverted by CD8+ cell depletion.

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Ivona Pandrea

2011-08-01

Full Text Available Understanding the mechanism of infection control in elite controllers (EC may shed light on the correlates of control of disease progression in HIV infection. However, limitations have prevented a clear understanding of the mechanisms of elite controlled infection, as these studies can only be performed at randomly selected late time points in infection, after control is achieved, and the access to tissues is limited. We report that SIVagm infection is elite-controlled in rhesus macaques (RMs and therefore can be used as an animal model for EC HIV infection. A robust acute infection, with high levels of viral replication and dramatic mucosal CD4(+ T cell depletion, similar to pathogenic HIV-1/SIV infections of humans and RMs, was followed by complete and durable control of SIVagm replication, defined as: undetectable VLs in blood and tissues beginning 72 to 90 days postinoculation (pi and continuing at least 4 years; seroreversion; progressive recovery of mucosal CD4(+ T cells, with complete recovery by 4 years pi; normal levels of T cell immune activation, proliferation, and apoptosis; and no disease progression. This "functional cure" of SIVagm infection in RMs could be reverted after 4 years of control of infection by depleting CD8 cells, which resulted in transient rebounds of VLs, thus suggesting that control may be at least in part immune mediated. Viral control was independent of MHC, partial APOBEC restriction was not involved in SIVagm control in RMs and Trim5 genotypes did not impact viral replication. This new animal model of EC lentiviral infection, in which complete control can be predicted in all cases, permits research on the early events of infection in blood and tissues, before the defining characteristics of EC are evident and when host factors are actively driving the infection towards the EC status.

T-regulatory cells depletion is the main cause for enhanced antitumor immunity during radio-sensitization of tumors by 2-deoxy-D-glucose

International Nuclear Information System (INIS)

Farooque, Abdullah; Verma, Amit; Singh, Niharika; Chauhan, Sachin Kumar Singh; Jethani, Jyoti; Adhikari, J.S.; Dwarakanath, B.S.; Afrin, Farhat

2014-01-01

Regulatory T cells (Tregs) are known to have profound effects in blocking anti-tumor immunity. Therefore, Tregs are seen as a major hurdle that must be overcome in order to improve the efficacy of cancer therapy. The glycolytic inhibitor, 2-deoxy-d-glucose (2-DG) enhances radiation and chemotherapeutics induced death of many cancer cells in vitro and local tumor control in vivo, which was found to be associated with the enhanced anti-tumor immunity. Therefore, we investigated the role of Tregs in determining the tumor response to the combined treatment of 2-DG plus ionizing radiation. Ehrlich ascites tumor bearing mice were administered with a single dose of 2-DG (2 gm/Kg/b.wt) intravenously just before focal irradiation (10 Gy). Immuno-phenotyping of Tregs in secondary lymphoid organs was carried out using flow cytometry, while related cytokines were analyzed using bead array and ELISA. Further, mRNA and protein levels of transcription factors were assessed in sorted splenic CD4 + cells and CD4 + CD25 + using real time PCR and Western blot techniques. Results clearly showed depletion (TRAIL mediated apoptosis) of T regs (CD4 + CD25 + FoxP3 + CD39 + FR4 + GITR + CD127 - ), in blood, spleen, lymph node and tumor following the combined treatment. This led to the immune activation in the periphery, secondary lymphoid organs and massive infiltration of CD4 + , CD8 + and NK cells in the tumor, which correlated well with the complete response (cure; tumor free survival). Association of Treg depletion with the tumor response was further confirmed using low doses of cyclophosphamide (which depletes Tegs) and rapamycin (activator of Tregs),wherein the depletor of Tregs enhanced the efficacy of combined treatment, while Tregs enhancer compromised the efficacy. These studies unequivocally established the role of Tregs in determining the therapeutic response and can be used as a target for enhancing the efficacy of this combined treatment, besides establishing the potential of

Effector Regulatory T Cells Reflect the Equilibrium between Antitumor Immunity and Autoimmunity in Adult T-cell Leukemia.

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Ureshino, Hiroshi; Shindo, Takero; Nishikawa, Hiroyoshi; Watanabe, Nobukazu; Watanabe, Eri; Satoh, Natsuko; Kitaura, Kazutaka; Kitamura, Hiroaki; Doi, Kazuko; Nagase, Kotaro; Kimura, Hiromi; Samukawa, Makoto; Kusunoki, Susumu; Miyahara, Masaharu; Shin-I, Tadasu; Suzuki, Ryuji; Sakaguchi, Shimon; Kimura, Shinya

2016-08-01

The regulatory T cells (Treg) with the most potent immunosuppressive activity are the effector Tregs (eTreg) with a CD45RA(-)Foxp3(++)CCR4(+) phenotype. Adult T-cell leukemia (ATL) cells often share the Treg phenotype and also express CCR4. Although mogamulizumab, a monoclonal antibody to CCR4, shows marked antitumor effects against ATL and peripheral T-cell lymphoma, concerns have been raised that it may induce severe autoimmune immunopathology by depleting eTregs. Here, we present case reports for two patients with ATL who responded to mogamulizumab but developed a severe skin rash and autoimmune brainstem encephalitis. Deep sequencing of the T-cell receptor revealed that ATL cells and naturally occurring Tregs within the cell population with a Treg phenotype can be clearly distinguished according to CADM1 expression. The onset of skin rash and brainstem encephalitis was coincident with eTreg depletion from the peripheral blood, whereas ATL relapses were coincident with eTreg recovery. These results imply that eTreg numbers in the peripheral blood sensitively reflect the equilibrium between antitumor immunity and autoimmunity, and that mogamulizumab might suppress ATL until the eTreg population recovers. Close monitoring of eTreg numbers is crucial if we are to provide immunomodulatory treatments that target malignancy without severe adverse events. Cancer Immunol Res; 4(8); 644-9. ©2016 AACR. ©2016 American Association for Cancer Research.

Bone marrow scintigraphy in hemopoietic depletion states

International Nuclear Information System (INIS)

Fortynova, J.; Bakos, K.; Pradacova, J.

1981-01-01

Bone marrow scintigraphy was performed in 29 patients with hemopoietic depletion states of various etiology. Two tracers were used for visualization, viz., sup(99m)Tc-sulfur-colloid and 111 InCl 3 ;some patients were examined using both indicators. 111 InCl 3 is bound to transferrin and is adsorbed on the surface of reticulocytes and erythroblasts. A scintillation camera PHO GAMMA SEARLE IV fitted with a moving table and computer CLINCOM were used to obtain whole-body images. The comparison of all scans and marrow puncture smears was done. In patients with aplastic anemia with both hyperplastic or hypoplastic marrow good correlation of bone marrow scans and sternal puncture smears was found. In several cases the scintigraphic examination helped to establish the diagnosis of marrow depletion. A peculiar disadvantage of the imaging method with either sup(99m)Tc-sulfur-colloid or 111 InCl 3 is that it shows the disorders in erythropoietic and reticuloendothelial cells whereas the defects in myelopoietic cell series and platelet precursors are not provable. According to literature data, great attention is paid to the prognostic value of scintigraphic examination in aplastic anemia. (author)

Bone marrow scintigraphy in hemopoietic depletion states

Energy Technology Data Exchange (ETDEWEB)

Fortynova, J. (Ustav Hematologie a Krevni Transfuze, Prague (Czechoslovakia)); Bakos, K.; Pradacova, J. (Karlova Univ., Prague (Czechoslovakia). Biofyzikalni Ustav)

1981-01-01

Bone marrow scintigraphy was performed in 29 patients with hemopoietic depletion states of various etiology. Two tracers were used for visualization, viz., sup(99m)Tc-sulfur-colloid and /sup 111/InCl/sub 3/; some patients were examined using both indicators. /sup 111/InCl/sub 3/ is bound to transferrin and is adsorbed on the surface of reticulocytes and erythroblasts. A scintillation camera PHO GAMMA SEARLE IV fitted with a moving table and computer CLINCOM were used to obtain whole-body images. The comparison of all scans and marrow puncture smears was done. In patients with aplastic anemia with both hyperplastic or hypoplastic marrow good correlation of bone marrow scans and sternal puncture smears was found. In several cases the scintigraphic examination helped to establish the diagnosis of marrow depletion. A peculiar disadvantage of the imaging method with either sup(99m)Tc-sulfur-colloid or /sup 111/InCl/sub 3/ is that it shows the disorders in erythropoietic and reticuloendothelial cells whereas the defects in myelopoietic cell series and platelet precursors are not provable. According to literature data, great attention is paid to the prognostic value of scintigraphic examination in aplastic anemia.

Effects of Acute Tryptophan Depletion on Three Different Types of Behavioral Impulsivity

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Donald M. Dougherty

2010-01-01

Full Text Available Introduction While central nervous system serotonin has been implicated in a variety of problematic impulsive behaviors, biological manipulation of brain serotonin using acute tryptophan depletion for studying changes in impulsive behavior has received little attention. Methods Using identical treatment conditions, we examined the effects of reduced serotonin synthesis for each of three matched groups using acute tryptophan depletion. Thirty healthy men and women (ages 18–45 were assigned to perform one of three tasks assessing different types of behavioral impulsivity: response initiation, response inhibition, and consequence sensitivity ( N = 90. Participants completed two experimental days during which each consumed either a tryptophan-depletion or balanced-placebo amino-acid formulation and completed 5 sessions of their respective tasks at 0.25 h before and 1.5, 4.0, 5.0, and 6.0 h after beverage consumption. Results During peak effectiveness (5.0 h to 6.0 h following amino-acid consumption, depletion produced selective differences dependent on the type of impulsivity being tested. Specifically, relative to baseline testing (pre-depletion, response initiation impulsivity was significantly increased during the peak effects of depletion. And, when compared to placebo control, both response initiation and consequence sensitivity impulsivity were increased during the peak effects of depletion. Conclusion Though response initiation and consequence sensitivity impulsivity were affected by tryptophan depletion, response inhibition impulsivity was not, suggesting that other biological processes may underlie this specific component of impulsivity. Future research in other populations or using different pharmacological agents is warranted to further examine the biological processes underlying these components of impulsivity.

Effects of Acute Tryptophan Depletion on Three Different Types of Behavioral Impulsivity

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Donald M. Dougherty

2010-06-01

Full Text Available Introduction: While central nervous system serotonin has been implicated in a variety of problematic impulsive behaviors, biological manipulation of brain serotonin using acute tryptophan depletion for studying changes in impulsive behavior has received little attention. Methods: Using identical treatment conditions, we examined the effects of reduced serotonin synthesis for each of three matched groups using acute tryptophan depletion. Thirty healthy men and women (ages 18–45 were assigned to perform one of three tasks assessing different types of behavioral impulsivity: response initiation, response inhibition, and consequence sensitivity (N = 90. Participants completed two experimental days during which each consumed either a tryptophan-depletion or balanced-placebo amino-acid formulation and completed 5 sessions of their respective tasks at 0.25 h before and 1.5, 4.0, 5.0, and 6.0 h after beverage consumption. Results: During peak effectiveness (5.0 h to 6.0 h following amino-acid consumption, depletion produced selective differences dependent on the type of impulsivity being tested. Specifically, relative to baseline testing (pre-depletion, response initiation impulsivity was significantly increased during the peak effects of depletion. And, when compared to placebo control, both response initiation and consequence sensitivity impulsivity were increased during the peak effects of depletion. Conclusion: Though response initiation and consequence sensitivity impulsivity were affected by tryptophan depletion, response inhibition impulsivity was not, suggesting that other biological processes may underlie this specific component of impulsivity. Future research in other populations or using different pharmacological agents is warranted to further examine the biological processes underlying these components of impulsivity.

FLIM studies of 22- and 25-NBD-cholesterol in living HEK293 cells: Plasma membrane change induced by cholesterol depletion

Czech Academy of Sciences Publication Activity Database

Ostašov, Pavel; Sýkora, Jan; Brejchová, Jana; Olžyńska, Agnieszka; Hof, Martin; Svoboda, Petr

167-168, FEB-MAR (2013), s. 62-69 ISSN 0009-3084 R&D Projects: GA ČR(CZ) GAP207/12/0919 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 ; RVO:61388955 Keywords : cholesterol depletion * beta-Cyclodextrin * 22-NBD-cholesterol * 25-NBD-cholesterol * FLIM studies * intact HEK293 cells Subject RIV: CE - Biochemistry; CF - Physical ; Theoretical Chemistry (UFCH-W) Impact factor: 2.593, year: 2013

Alteration in murine epidermal Langerhans cell population by various UV irradiations: quantitative and morphologic studies on the effects of various wavelengths of monochromatic radiation on Ia-bearing cells

International Nuclear Information System (INIS)

Obata, M.; Tagami, H.

1985-01-01

The present study was undertaken in order to clarify the exact mode of the Langerhans cell (LC) depleting process caused by UV irradiation. Following irradiation with a single dose of various wavelengths of monochromatic UV radiation (UVR), the number of Ia-positive cells were studied in mouse epidermal sheets quantitatively, particularly with regard to dose-response relationships, action spectrum, and time course change. In addition, morphologic alterations of these cells were studied using electron- and immunoelectron microscopy (EM and IEM). The authors obtained the following results after a single dose of UVB radiation (200 mJ/cm2 of 300 nm) or PUVA (1% of 8-methoxypsoralen (8-MOP) 20 microliter and 1 J/cm2 of 360 nm): (1) EM and IEM showed that while some LCs simply lost their Ia marker without any structural alterations, the majority of the LCs disappeared due to actual cell damage. (2) During an ''injury phase,'' the initial 48 h, and a ''recovery phase,'' lasting from 4-14 days after irradiation, enlargement of the size of remaining Ia-positive LCs occurred. The degree of enlargement was closely related to the degree of reduction in number, suggesting a process compensating for the loss of the LC population. (3) It was found that the recovery rate of LCs after irradiation damage was slower than that of keratinocytes, indicating different cell kinetics between these distinct cell populations in the epidermis, i.e., restoration of LCs after irradiation seems to be achieved at least partially through a repopulation process originating in the bone marrow

Energetic magnetospheric protons in the plasma depletion layer

International Nuclear Information System (INIS)

Fuselier, S.A.

1992-01-01

Interplanetary magnetic field draping against the Earth's dayside subsolar magnetopause creates a region of reduced plasma density and increased magnetic field called the plasma depletion layer. In this region, leakage of energetic ions from the Earth's magnetosphere onto magnetic field lines in the plasma depletion layer can be studied without interference from ions accelerated at the Earth's quasi-parallel bow shock. Active Magnetospheric Particle Tracer Experiment/Charge Composition Explorer (AMPTE/CCE) observations for 13 plasma depletion layer events are used to determine the characteristics of energetic protons between a few keV/e and ∼100keV/e leaked from the magnetosphere. Results indicate that the leaked proton distributions resemble those in the magnetosphere except that they have lower densities and temperatures and much higher velocities parallel (or antiparallel) and perpendicular to the magnetic field. Compared to the low-energy magnetosheath proton distributions present in the depletion layer, the leaked energetic proton distributions typically have substantially higher flow velocities along the magnetic field indicate that the leaked energetic proton distributions to contribute to the energetic proton population seen upstream and downstream from the quasi-parallel bow shock. However, their contribution is small compared to the contribution from acceleration of protons at the bow shock because the leaked proton densities are on the order of 10 times smaller than the energetic proton densities typically observed in the vicinity of the quasi-parallel bow shock

L-Tryptophan depletion bioreactor, a possible cancer therapy

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Rolf Bambauer

2015-04-01

Full Text Available The cancer therapeutic strategies knownto date are not adequate for all cancer patients. Most of them are followed by a high rate of side effects and complications. The L-tryptophan depletion bioreactor is described as a possible new method of cancer therapy. L-tryptophan is an essential amino acid which has been recognized as an important cancer nutrient and its removal can lead to destruction of the tumour. Normal human cells or tumor cells cannot synthesize L-tryptophan and therefore tumor resistance is unlikely to develop. L-tryptophan is also a constituent for different bio-molecules such as Serotonin, Melatonin, and is needed for other synthesis processes in the cell growth. L-tryptophan degrading enzymes with 3 iso-enzymes called tryptophan side chain oxydase (TSO I, II, III were isolated. The 3 iso-enzymes can be differentiated by tryptic digestion. They have different molecular weights with different effectivenesses. All the TSO enzymes have heme that can catalyze essentially similar reactions involving L-tryptophan as a substrate. The most effective TSO is the type TSO III. A column which contained TSO as a bioreactor was integrated in a plasmapheresis unit and tested it in different animals. In sheep and rabbits L-tryptophan depletion in plasma was shown at 95% and 100% rates respectively by a single pass through the bioreactor. The results in immune supprimized rats with tumors were impressive, too. In 20 different tumor cell lines there were different efficacies. Brest cancer and medulloblastoma showed the greatest efficacy of L-tryptophan degrading. The gene technology of TSO production from Pseudomonas is associated with formation of endotoxins. This disadvantage can be prevented by different washing procedures or by using fungal sources for the TSO production. TSO III is developed to treat cancer diseases successfully, and has low side effects. A combination of L-tryptophan depletion with all available cancer therapies is

Depletion of intracellular calcium stores facilitates the influx of extracellular calcium in platelet derived growth factor stimulated A172 glioblastoma cells.

Science.gov (United States)

Vereb, G; Szöllösi, J; Mátyus, L; Balázs, M; Hyun, W C; Feuerstein, B G

1996-05-01

Calcium signaling in non-excitable cells is the consequence of calcium release from intracellular stores, at times followed by entry of extracellular calcium through the plasma membrane. To study whether entry of calcium depends upon the level of saturation of intracellular stores, we measured calcium channel opening in the plasma membrane of single confluent A172 glioblastoma cells stimulated with platelet derived growth factor (PDGF) and/or bradykinin (BK). We monitored the entry of extracellular calcium by measuring manganese quenching of Indo-1 fluorescence. PDGF raised intracellular calcium concentration ([Ca2+]i) after a dose-dependent delay (tdel) and then opened calcium channels after a dose-independent delay (tch). At higher doses (> 3 nM), BK increased [Ca2+]i after a tdel approximately 0 s, and tch decreased inversely with both dose and peak [Ca2+]i. Experiments with thapsigargin (TG), BK, and PDGF indicated that BK and PDGF share intracellular Ca2+ pools that are sensitive to TG. When these stores were depleted by treatment with BK and intracellular BAPTA, tdel did not change, but tch fell to almost 0 s in PDGF stimulated cells, indicating that depletion of calcium stores affects calcium channel opening in the plasma membrane. Our data support the capacitative model for calcium channel opening and the steady-state model describing quantal Ca2+ release from intracellular stores.

NK1.1+ cells promote sustained tissue injury and inflammation after trauma with hemorrhagic shock.

Science.gov (United States)

Chen, Shuhua; Hoffman, Rosemary A; Scott, Melanie; Manson, Joanna; Loughran, Patricia; Ramadan, Mostafa; Demetris, Anthony J; Billiar, Timothy R

2017-07-01

Various cell populations expressing NK1.1 contribute to innate host defense and systemic inflammatory responses, but their role in hemorrhagic shock and trauma remains uncertain. NK1.1 + cells were depleted by i.p. administration of anti-NK1.1 (or isotype control) on two consecutive days, followed by hemorrhagic shock with resuscitation and peripheral tissue trauma (HS/T). The plasma levels of IL-6, MCP-1, alanine transaminase (ALT), and aspartate aminotransferase (AST) were measured at 6 and 24 h. Histology in liver and gut were examined at 6 and 24 h. The number of NK cells, NKT cells, neutrophils, and macrophages in liver, as well as intracellular staining for TNF-α, IFN-γ, and MCP-1 in liver cell populations were determined by flow cytometry. Control mice subjected to HS/T exhibited end organ damage manifested by marked increases in circulating ALT, AST, and MCP-1 levels, as well as histologic evidence of hepatic necrosis and gut injury. Although NK1.1 + cell-depleted mice exhibited a similar degree of organ damage as nondepleted animals at 6 h, NK1.1 + cell depletion resulted in marked suppression of both liver and gut injury by 24 h after HS/T. These findings indicate that NK1.1 + cells contribute to the persistence of inflammation leading to end organ damage in the liver and gut. © Society for Leukocyte Biology.

Synovial CD4+ T-cell-derived GM-CSF supports the differentiation of an inflammatory dendritic cell population in rheumatoid arthritis

Science.gov (United States)

Reynolds, G; Gibbon, J R; Pratt, A G; Wood, M J; Coady, D; Raftery, G; Lorenzi, A R; Gray, A; Filer, A; Buckley, C D; Haniffa, M A; Isaacs, J D; Hilkens, C M U

2016-01-01

Objective A population of synovial inflammatory dendritic cells (infDCs) has recently been identified in rheumatoid arthritis (RA) and is thought to be monocyte-derived. Here, we investigated the role and source of granulocyte macrophage-colony-stimulating factor (GM-CSF) in the differentiation of synovial infDC in RA. Methods Production of GM-CSF by peripheral blood (PB) and synovial fluid (SF) CD4+ T cells was assessed by ELISA and flow cytometry. In vitro CD4+ T-cell polarisation experiments were performed with T-cell activating CD2/CD3/CD28-coated beads in the absence or presence of pro-Th1 or pro-Th17 cytokines. CD1c+ DC and CD16+ macrophage subsets were flow-sorted and analysed morphologically and functionally (T-cell stimulatory/polarising capacity). Results RA-SF CD4+ T cells produced abundant GM-CSF upon stimulation and significantly more than RA-SF mononuclear cells depleted of CD4+ T cells. GM-CSF-producing T cells were significantly increased in RA-SF compared with non-RA inflammatory arthritis SF, active RA PB and healthy donor PB. GM-CSF-producing CD4+ T cells were expanded by Th1-promoting but not Th17-promoting conditions. Following coculture with RA-SF CD4+ T cells, but not healthy donor PB CD4+ T cells, a subpopulation of monocytes differentiated into CD1c+ infDC; a process dependent on GM-CSF. These infDC displayed potent alloproliferative capacity and enhanced GM-CSF, interleukin-17 and interferon-γ production by CD4+ T cells. InfDC with an identical phenotype to in vitro generated cells were significantly enriched in RA-SF compared with non-RA-SF/tissue/PB. Conclusions We demonstrate a therapeutically tractable feedback loop of GM-CSF secreted by RA synovial CD4+ T cells promoting the differentiation of infDC with potent capacity to induce GM-CSF-producing CD4+ T cells. PMID:25923217

Conditional Macrophage Depletion Increases Inflammation and Does Not Inhibit the Development of Osteoarthritis in Obese Macrophage Fas-Induced Apoptosis-Transgenic Mice.

Science.gov (United States)

Wu, Chia-Lung; McNeill, Jenna; Goon, Kelsey; Little, Dianne; Kimmerling, Kelly; Huebner, Janet; Kraus, Virginia; Guilak, Farshid

2017-09-01

To investigate whether short-term, systemic depletion of macrophages can mitigate osteoarthritis (OA) following injury in the setting of obesity. CSF-1R-GFP+ macrophage Fas-induced apoptosis (MaFIA)-transgenic mice that allow conditional depletion of macrophages were placed on a high-fat diet and underwent surgery to induce knee OA. A small molecule (AP20187) was administrated to deplete macrophages in MaFIA mice. The effects of macrophage depletion on acute joint inflammation, OA severity, and arthritic bone changes were evaluated using histology and micro-computed tomography. Immunohistochemical analysis was performed to identify various immune cells. The levels of serum and synovial fluid cytokines were also measured. Macrophage-depleted mice had significantly fewer M1 and M2 macrophages in the surgically operated joints relative to controls and exhibited decreased osteophyte formation immediately following depletion. Surprisingly, macrophage depletion did not attenuate the severity of OA in obese mice; instead, it induced systemic inflammation and led to a massive infiltration of CD3+ T cells and particularly neutrophils, but not B cells, into the injured joints. Macrophage-depleted mice also demonstrated a markedly increased number of proinflammatory cytokines including granulocyte colony-stimulating factor, interleukin-1β (IL-1β), IL-6, IL-8, and tumor necrosis factor in both serum and joint synovial fluid, although the mice showed a trend toward decreased levels of insulin and leptin in serum after macrophage depletion. Our findings indicate that macrophages are vital for modulating homeostasis of immune cells in the setting of obesity and suggest that more targeted approaches of depleting specific macrophage subtypes may be necessary to mitigate inflammation and OA in the setting of obesity. © 2017, American College of Rheumatology.

Making sense of snapshot data: ergodic principle for clonal cell populations.

Science.gov (United States)

Thomas, Philipp

2017-11-01

Population growth is often ignored when quantifying gene expression levels across clonal cell populations. We develop a framework for obtaining the molecule number distributions in an exponentially growing cell population taking into account its age structure. In the presence of generation time variability, the average acquired across a population snapshot does not obey the average of a dividing cell over time, apparently contradicting ergodicity between single cells and the population. Instead, we show that the variation observed across snapshots with known cell age is captured by cell histories, a single-cell measure obtained from tracking an arbitrary cell of the population back to the ancestor from which it originated. The correspondence between cells of known age in a population with their histories represents an ergodic principle that provides a new interpretation of population snapshot data. We illustrate the principle using analytical solutions of stochastic gene expression models in cell populations with arbitrary generation time distributions. We further elucidate that the principle breaks down for biochemical reactions that are under selection, such as the expression of genes conveying antibiotic resistance, which gives rise to an experimental criterion with which to probe selection on gene expression fluctuations. © 2017 The Author(s).

An Antigen-Presenting and Apoptosis-Inducing Polymer Microparticle Prolongs Alloskin Graft Survival by Selectively and Markedly Depleting Alloreactive CD8+ T Cells

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Wei Wang

2017-06-01

Full Text Available Selectively depleting the pathogenic T cells is a fundamental strategy for the treatment of allograft rejection and autoimmune disease since it retains the overall immune function of host. The concept of killer artificial antigen-presenting cells (KaAPCs has been developed by co-coupling peptide–major histocompatibility complex (pMHC multimer and anti-Fas monoclonal antibody (mAb onto the polymeric microparticles (MPs to induce the apoptosis of antigen-specific T cells. But little information is available about its in vivo therapeutic potential and mechanism. In this study, polyethylenimine (PEI-coated poly lactic-co-glycolic acid microparticle (PLGA MP was fabricated as a cell-sized scaffold to covalently co-couple H-2Kb-Ig dimer and anti-Fas mAb for the generation of alloantigen-presenting and apoptosis-inducing MPs. Intravenous infusions of the biodegradable KaAPCs prolonged the alloskin graft survival for 43 days in a single MHC-mismatched murine model, depleted the most of H-2Kb-alloreactive CD8+ T cells in peripheral blood, spleen, and alloskin graft in an antigen-specific manner and anti-Fas-dependent fashion. The cell-sized KaAPCs circulated throughout vasculature into liver, kidney, spleen, lymph nodes, lung, and heart, but few ones into local allograft at early stage, with a retention time up to 36 h in vivo. They colocalized with CD8+ T cells in secondary lymphoid organs while few ones contacted with CD4+ T cells, B cells, macrophage, and dendritic cells, or internalized by phagocytes. Importantly, the KaAPC treatment did not significantly impair the native T cell repertoire or non-pathogenic immune cells, did not obviously suppress the overall immune function of host, and did not lead to visible organ toxicity. Our results strongly document the high potential of PLGA MP-based KaAPCs as a novel antigen-specific immunotherapy for allograft rejection and autoimmune disorder. The in vivo mechanism of alloinhibition, tissue

Ozone-depleting Substances (ODS)

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U.S. Environmental Protection Agency — This site includes all of the ozone-depleting substances (ODS) recognized by the Montreal Protocol. The data include ozone depletion potentials (ODP), global warming...

Sensitivity of mitochondrial DNA depleted ρ0 cells to H2O2 depends on the plasma membrane status.

Science.gov (United States)

Tomita, Kazuo; Kuwahara, Yoshikazu; Takashi, Yuko; Tsukahara, Takao; Kurimasa, Akihiro; Fukumoto, Manabu; Nishitani, Yoshihiro; Sato, Tomoaki

2017-08-19

To clarify the relationship between mitochondrial DNA (mtDNA)-depleted ρ0 cells and the cellular sensitivity to hydrogen peroxide (H 2 O 2 ), we established HeLa and SAS ρ0 cell lines and investigated their survival rate in H 2 O 2 , radical scavenging enzymes, plasma membrane potential status, and chronological change in intracellular H 2 O 2 amount under the existence of extracellular hydrogen peroxide compared with the parental cells. The results revealed that ρ0 cells had higher sensitivity to H 2 O 2 than their parental cells, even though the catalase activity of ρ0 cells was up-regulated, and the membrane potential of the ρ0 cells was lower than their parental cells. Furthermore, the internal H 2 O 2 amount significantly increased only in ρ0 cells after 50 μM H 2 O 2 treatment for 1 h. These results suggest that plasma membrane status of ρ0 cells may cause degradation, and the change could lead to enhanced membrane permeability to H 2 O 2 . As a consequence, ρ0 cells have a higher H 2 O 2 sensitivity than the parental cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Acute MUS81 depletion leads to replication fork slowing and a constitutive DNA damage response

DEFF Research Database (Denmark)

Xing, Meichun; Wang, Xiaohui; Palmai-Pallag, Timea

2015-01-01

have investigated the role of MUS81 in human cells by acutely depleting the protein using shRNAs. We found that MUS81 depletion from human fibroblasts leads to accumulation of ssDNA and a constitutive DNA damage response that ultimately activates cellular senescence. Moreover, we show that MUS81...

Heat Shock Factor 1 Depletion Sensitizes A172 Glioblastoma Cells to Temozolomide via Suppression of Cancer Stem Cell-Like Properties

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Chang-Nim Im

2017-02-01

Full Text Available Heat shock factor 1 (HSF1, a transcription factor activated by various stressors, regulates proliferation and apoptosis by inducing expression of target genes, such as heat shock proteins and Bcl-2 (B-cell lymphoma 2 interacting cell death suppressor (BIS. HSF1 also directly interacts with BIS, although it is still unclear whether this interaction is critical in the regulation of glioblastoma stem cells (GSCs. In this study, we examined whether small interfering RNA-mediated BIS knockdown decreased protein levels of HSF1 and subsequent nuclear localization under GSC-like sphere (SP-forming conditions. Consistent with BIS depletion, HSF1 knockdown also reduced sex determining region Y (SRY-box 2 (SOX2 expression, a marker of stemness, accompanying the decrease in SP-forming ability and matrix metalloprotease 2 (MMP2 activity. When HSF1 or BIS knockdown was combined with temozolomide (TMZ treatment, a standard drug used in glioblastoma therapy, apoptosis increased, as measured by an increase in poly (ADP-ribose polymerase (PARP cleavage, whereas cancer stem-like properties, such as colony-forming activity and SOX2 protein expression, decreased. Taken together, our findings suggest that targeting BIS or HSF1 could be a viable therapeutic strategy for GSCs resistant to conventional TMZ treatment.

Experimentally-induced immune activation in natural hosts of SIV induces significant increases in viral replication and CD4+ T cell depletion

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, Ruy M [Los Alamos National Laboratory

2008-01-01

Chronically SIVagm-infected African green monkeys (AGMs) have a remarkably stable non-pathogenic disease course, with levels of immune activation in chronic SIVagm infection similar to those observed in uninfected monkeys and stable viral loads (VLs) for long periods of time. In vivo administration of lipopolysaccharide (LPS) or an IL-2/diphtheria toxin fusion protein (Ontak) to chronically SIVagm-infected AGMs triggered increases in immune activation and subsequently of viral replication and depletion of intestinal CD4{sup +} T cells. Our study indicates that circulating microbial products can increase viral replication by inducing immune activation and increasing the number of viral target cells, thus demonstrating that immune activation and T cell prolifeation are key factors in AIDS pathogenesis.

Concise Review: Stem Cell Population Biology: Insights from Hematopoiesis.

Science.gov (United States)

MacLean, Adam L; Lo Celso, Cristina; Stumpf, Michael P H

2017-01-01

Stem cells are fundamental to human life and offer great therapeutic potential, yet their biology remains incompletely-or in cases even poorly-understood. The field of stem cell biology has grown substantially in recent years due to a combination of experimental and theoretical contributions: the experimental branch of this work provides data in an ever-increasing number of dimensions, while the theoretical branch seeks to determine suitable models of the fundamental stem cell processes that these data describe. The application of population dynamics to biology is amongst the oldest applications of mathematics to biology, and the population dynamics perspective continues to offer much today. Here we describe the impact that such a perspective has made in the field of stem cell biology. Using hematopoietic stem cells as our model system, we discuss the approaches that have been used to study their key properties, such as capacity for self-renewal, differentiation, and cell fate lineage choice. We will also discuss the relevance of population dynamics in models of stem cells and cancer, where competition naturally emerges as an influential factor on the temporal evolution of cell populations. Stem Cells 2017;35:80-88. © 2016 AlphaMed Press.

Monocyte-derived dendritic cells are essential for CD8+ T cell activation and anti-tumor responses after local immunotherapy

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Sabine eKuhn

2015-11-01

Full Text Available Tumors harbor several populations of dendritic cells with the ability to prime tumor-specific T cells. However, these T cells mostly fail to differentiate into armed effectors and are unable to control tumor growth. We have previously shown that treatment with immunostimulatory agents at the tumor site can activate anti-tumor immune responses, and is associated with the appearance of a population of monocyte-derived dendritic cells in the tumor and tumor-draining lymph node. Here we use dendritic cell or monocyte depletion and monocyte transfer to show that these monocyte-derived dendritic cells are critical to the activation of anti-tumor immune responses. Treatment with the immunostimulatory agents Monosodium Urate crystals and Mycobacterium smegmatis induced the accumulation of monocytes in the draining lymph node, their upregulation of CD11c and MHCII, and expression of iNOS, TNFα and IL12p40. Blocking monocyte entry into the lymph node and tumor through neutralization of the chemokine CCL2 or inhibition of Colony Stimulating Factor-1 receptor signaling prevented the generation of monocyte-derived dendritic cells, the infiltration of tumor-specific T cells into the tumor, and anti-tumor responses. In a reciprocal fashion, monocytes transferred into mice depleted of CD11c+ cells were sufficient to rescue CD8+ T cell priming in lymph node and delay tumor growth. Thus monocytes exposed to the appropriate conditions become powerful activators of tumor-specific CD8+ T cells and anti-tumor immunity.

Evaluation of the Westinghouse 10B depletion for BWR control rods

International Nuclear Information System (INIS)

Vallgren, Christina

2008-03-01

The aim of this work was to establish the 10 B depletion model for CR 99 control rods by using the latest version of POLCA7. In order to obtain an understanding of the differences between the currently used 10 B depletion models implemented in POLCA4 at O3 and in SIMULATE-3 at OL1, and the latest improved model implemented in the latest POLCA7, this work has been performed in three different parts. The first part of the work was to find out how large differences there exist in 10 B depletion between the calculated data by using the latest core monitoring system (POLCA7 version 4.10.0) and the measured data obtained in the hot-cell laboratory in Studsvik. It was found that the 10 B depletion computed by the latest POLCA7 version is in good agreement with the measured data from Studsvik. A poor agreement with a conservative overestimation in 10 B depletion was also found between the old model and the measured data. The aim of the second part of the work was to compare the calculated 10 B depletion values for two CR 99 rods from Olkiluoto 1 with the calculated 10 B depletion value for a CR 99 rod from Oskarshamn 3, by using the new 10 B depletion model implemented in the latest POLCA7 version. Swelling measurements of the boron carbide pins, used as absorber material, have indicated that the 10 B depletion should be of similar magnitude for the rods in Olkiluoto 1 and the rod in Oskarshamn 3, whereas the calculated values by using the earlier 10 B depletion models on the process computers showed a difference of about 20 %. By using the new 10 B depletion model m POLCA7, it was found that the 10 B depletion in the two studied cases was similar to each other and, thus, the hypothesis of a linear relationship between B 4 C swelling and thermal neutron fluence was supported. This third part of the work was carried out at KKL, Switzerland, and focused on comparing the B depletion models used in Westinghouse/POLCA7 and KKL/PRESTO-2. It was found that there is a slight

Evaluation of the Westinghouse 10B depletion for BWR control rods

Energy Technology Data Exchange (ETDEWEB)

Vallgren, Christina

2008-03-15

The aim of this work was to establish the 10B depletion model for CR 99 control rods by using the latest version of POLCA7. In order to obtain an understanding of the differences between the currently used 10B depletion models implemented in POLCA4 at O3 and in SIMULATE-3 at OL1, and the latest improved model implemented in the latest POLCA7, this work has been performed in three different parts. The first part of the work was to find out how large differences there exist in 10B depletion between the calculated data by using the latest core monitoring system (POLCA7 version 4.10.0) and the measured data obtained in the hot-cell laboratory in Studsvik. It was found that the 10B depletion computed by the latest POLCA7 version is in good agreement with the measured data from Studsvik. A poor agreement with a conservative overestimation in 10B depletion was also found between the old model and the measured data. The aim of the second part of the work was to compare the calculated 10B depletion values for two CR 99 rods from Olkiluoto 1 with the calculated 10B depletion value for a CR 99 rod from Oskarshamn 3, by using the new 10B depletion model implemented in the latest POLCA7 version. Swelling measurements of the boron carbide pins, used as absorber material, have indicated that the 10B depletion should be of similar magnitude for the rods in Olkiluoto 1 and the rod in Oskarshamn 3, whereas the calculated values by using the earlier 10B depletion models on the process computers showed a difference of about 20 %. By using the new 10B depletion model m POLCA7, it was found that the 10B depletion in the two studied cases was similar to each other and, thus, the hypothesis of a linear relationship between B{sub 4}C swelling and thermal neutron fluence was supported. This third part of the work was carried out at KKL, Switzerland, and focused on comparing the B depletion models used in Westinghouse/POLCA7 and KKL/PRESTO-2. It was found that there is a slight difference in

A role for b-cell-depleting agents in treating psoriatic skin lesions induced by tumor necrosis factor-alpha antagonists: A case report and literature review

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Ancuta Codrina Mihaela

2014-01-01

Full Text Available Despite recent advances in understanding the pathological pathways, clinical pattern and management opportunities for new-onset psoriasis as a paradoxical adverse event in patients receiving TNF inhibitors for their immune-mediated disorder, there is a subset of patients who are either partial responders or non-responders, whatever the therapeutic scenario. We present the case of new-onset psoriasis and severe alopecia development in a case study of long-standing rheumatoid arthritis (RA treated with adalimumab (ADA and leflunomide. Since skin lesions and alopecia are resistant to the classic protocol (topical treatment, ADA discontinuation and RA becomes highly active, rituximab (RTX was started. Dramatic improvement in joint disease, total remission of alopecia and partial remission of pustular psoriasis were described after the first RTX cycle. Although B-cell-depleting agents result in controversial effects on psoriatic skin lesions, this is the first case of ADA-induced psoriasis and alopecia that improved under RTX, suggesting a possible role in treating such a patient population.

Depleted aldehyde dehydrogenase 1A1 (ALDH1A1) reverses cisplatin resistance of human lung adenocarcinoma cell A549/DDP.

Science.gov (United States)

Wei, Yunyan; Wu, Shuangshuang; Xu, Wei; Liang, Yan; Li, Yue; Zhao, Weihong; Wu, Jianqing

2017-01-01

Cisplatin is the standard first-line chemotherapeutic agent for the treatment of non-small cell lung cancer (NSCLC). However, resistance to chemotherapy has been a major obstacle in the management of NSCLC. Aldehyde dehydrogenase 1A1 (ALDH1A1) overexpression has been observed in a variety of cancers, including lung cancer. The purpose of this study was to investigate the effect of ALDH1A1 expression on cisplatin resistance and explore the mechanism responsible. Reverse transcriptase-PCR was applied to measure the messenger RNA expression of ALDH1A1, while Western blot assay was employed to evaluate the protein expression of ALDH1A1, B-cell lymphoma 2, Bcl-2-like protein 4, phospho-protein kinase B (p-AKT) and AKT. A short hairpin RNA was used to knockdown ALDH1A1 expression. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine the effect of ALDH1A1 decrease on cell viability. The cell apoptotic rate was tested using flow cytometry assay. ALDH1A1 is overexpressed in cisplatin resistant cell line A549/DDP, compared with A549. ALDH1A1 depletion significantly decreased A549/DDP proliferation, increased apoptosis, and reduced cisplatin resistance. In addition, the phosphoinositide 3-kinase (PI3K) / AKT pathway is activated in A549/DDP, and ALDH1A1 knockdown reduced the phosphorylation level of AKT. Moreover, the combination of ALDH1A1-short hairpin RNA and PI3K/AKT pathway inhibitor LY294002 markedly inhibited cell viability, enhanced apoptotic cell death, and increased cisplatin sensitivity. These results suggest that ALDH1A1 depletion could reverse cisplatin resistance in human lung cancer cell line A549/DDP, and may act as a potential target for the treatment of lung cancers resistant to cisplatin. © 2016 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

Chapter 22. Cell population kinetics

International Nuclear Information System (INIS)

Tubiana, M.

1975-01-01

The main contribution of radioisotopes to the development of a new discipline, cell population kinetics, was shown. The aim of this science is to establish, for each tissue of the organism, the life span of its component cells and the mechanisms governing its growth, its differentiation and its homeostasis with respect to outside attacks. Labelling techniques have been used to follow the cells during these various processes. The case of non-dividing cells was considered first, taking as example, the red blood cells of which the lifetime was studied, after which the case of proliferating cells was examined using 14 C- or tritium-labelled thymidine. The methods used to measure the cell cycle parameters were described: labelled-mitosis curve method, double-labelling and continuous labelling methods, proliferation coefficient measurement. Cell kinetics were shown to allow an interpretation of radiobiological data. Finally the practical value of cell kinetics research was shown [fr

Nucleotide Pool Depletion Induces G-Quadruplex-Dependent Perturbation of Gene Expression

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Charikleia Papadopoulou

2015-12-01

Full Text Available Nucleotide pool imbalance has been proposed to drive genetic instability in cancer. Here, we show that slowing replication forks by depleting nucleotide pools with hydroxyurea (HU can also give rise to both transient and permanent epigenetic instability of a reporter locus, BU-1, in DT40 cells. HU induces stochastic formation of Bu-1low variants in dividing cells, which have lost the H3K4me3 present in untreated cells. This instability is potentiated by an intragenic G quadruplex, which also promotes local H2Ax phosphorylation and transient heterochromatinization. Genome-wide, gene expression changes induced by HU significantly overlap with those resulting from loss of the G4-helicases FANCJ, WRN, and BLM. Thus, the effects of global replication stress induced by nucleotide pool depletion can be focused by local replication impediments caused by G quadruplex formation to induce epigenetic instability and changes in gene expression, a mechanism that may contribute to selectable transcriptional changes in cancer.

Depletion of trophy large-sized sharks populations of the Argentinean coast, south-western Atlantic: insights from fishers' knowledge

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Alejo Irigoyen

Full Text Available Abstract Globally, sharks are impacted by a wide range of human activities, resulting in many populations being depleted. Trophy large-sized sharks of the Argentinean coast, the sand-tiger Carcharias taurus , the copper Carcharhinus brachyurus and the sevengill shark Notorynchus cepedianus are under intense sport and artisanal fishing since the 50's decade. However, the current and historical information for the assessment of its populations status is scarce. The aim of this work was to analyze the status of conservation of these species through the gathering of expert fishermen knowledge (FK on semi-structured interviews. Abundance variation perception between the beginning and the end of fishermen careers revealed a critical status for the species study (means variation between -77 and -90 %. Furthermore, a best day's catch analysis reinforce this result in the case of the sand tiger shark. The school shark Galeorhinus galeus was included on this work with the objective of contrast FK with formal information available of catch-per-unit-effort (CPUE time series. Both sources of information, despite are not comparable, shows declines ~ - 80%. The critical conservation situation of study species needs urgent management action, particularly for the san tiger shark which could became regionally extinct before the reaction of stakeholders occurs.

Regeneration of stem-cells in intestinal epithelium after irradiation

International Nuclear Information System (INIS)

Hendry, J.H.

1979-01-01

Stem-cells can be defined as pluripotent progenitor cells, capable of both self-renewal and differentitation into all the functional end-cells typical of that cell family. Intestinal crypts contain population of cells which is capable of a) self-renewal following the severe depletion after radiation injury, b) replacing all other cypt cell types, and c) regeneration following repeated depletion (in colon). These are the properties of stem cells. Most measurements of the rate of regeneration of these cells following the severe depletion by radiation have been made by employing large test dose at increasing times. Such measurements have produced widely differing rates of increase in the survival under the test dose, from 4 hours (macrocolonies in jejunum) to 43 hours (microcolonies in stomach). In other tissues, large single test doses have been used to derive the time of doubling survival ratio e.g. for epidermal clones. Although cryptogenic cell number per crypt can be virtually restored by day 4 after a single dose and probably after many such doses, the status quo cannot be reached until the number of crypts is restored to normal. Stem cell numbers form a necessary part of the integrity of epitheliums. The quality of the stem cell function of survivors as expressed in the differentiated progeny, and the maintenance of function of the supportive environment are equally important for late radiation damage. (Yamashita, S.)

Multiple dendritic cell populations activate CD4+ T cells after viral stimulation.

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Adele M Mount

2008-02-01

Full Text Available Dendritic cells (DC are a heterogeneous cell population that bridge the innate and adaptive immune systems. CD8alpha DC play a prominent, and sometimes exclusive, role in driving amplification of CD8(+ T cells during a viral infection. Whether this reliance on a single subset of DC also applies for CD4(+ T cell activation is unknown. We used a direct ex vivo antigen presentation assay to probe the capacity of flow cytometrically purified DC populations to drive amplification of CD4(+ and CD8(+ T cells following infection with influenza virus by different routes. This study examined the contributions of non-CD8alpha DC populations in the amplification of CD8(+ and CD4(+ T cells in cutaneous and systemic influenza viral infections. We confirmed that in vivo, effective immune responses for CD8(+ T cells are dominated by presentation of antigen by CD8alpha DC but can involve non-CD8alpha DC. In contrast, CD4(+ T cell responses relied more heavily on the contributions of dermal DC migrating from peripheral lymphoid tissues following cutaneous infection, and CD4 DC in the spleen after systemic infection. CD4(+ T cell priming by DC subsets that is dependent upon the route of administration raises the possibility that vaccination approaches could be tailored to prime helper T cell immunity.

“When the going gets tough, who keeps going?” Depletion sensitivity moderates the ego-depletion effect

NARCIS (Netherlands)

Salmon, S.J.; Adriaanse, M.A.; Vet, de E.W.M.L.; Fennis, B.M.; Ridder, de D.T.D.

2014-01-01

Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In

Carbon and nitrogen depletion-induced nucleophagy and selective autophagic sequestration of a whole nucleus in multinucleate cells of the filamentous fungus Aspergillus oryzae.

Science.gov (United States)

Kikuma, Takashi; Mitani, Takahiro; Kohara, Takahiro; Maruyama, Jun-Ichi; Kitamoto, Katsuhiko

2017-05-12

Autophagy is a conserved cellular degradation process in eukaryotes, in which cytoplasmic components and organelles are digested in vacuoles/lysosomes. Recently, autophagic degradation of nuclear materials, termed "nucleophagy", has been reported. In the multinucleate filamentous fungus Aspergillus oryzae, a whole nucleus is degraded by nucleophagy after prolonged culture. While developing an H2B-EGFP processing assay for the evaluation of nucleophagy in A. oryzae, we found that nucleophagy is efficiently induced by carbon or nitrogen depletion. Microscopic observations in a carbon depletion condition clearly demonstrated that autophagosomes selectively sequester a particular nucleus, despite the presence of multiple nuclei in the same cell. Furthermore, AoNsp1, the A. oryzae homolog of the yeast nucleoporin Nsp1p, mainly localized at the nuclear periphery, but its localization was restricted to the opposite side of the autophagosome being formed around a nucleus. In contrast, the perinuclear ER visualized with the calnexin AoClxA was not morphologically affected by nucleophagy. The findings of nucleophagy-inducing conditions enabled us to characterize the morphological process of autophagic degradation of a whole nucleus in multinucleate cells.

HIV-1 Infection Is Associated with Depletion and Functional Impairment of Mycobacterium tuberculosis-Specific CD4 T Cells in Individuals with Latent Tuberculosis Infection.

Science.gov (United States)

Day, Cheryl L; Abrahams, Deborah A; Harris, Levelle D; van Rooyen, Michele; Stone, Lynnett; de Kock, Marwou; Hanekom, Willem A

2017-09-15

Coinfection with HIV is the single greatest risk factor for reactivation of latent Mycobacterium tuberculosis infection (LTBI) and progression to active tuberculosis disease. HIV-associated dysregulation of adaptive immunity by depletion of CD4 Th cells most likely contributes to loss of immune control of LTBI in HIV-infected individuals, although the precise mechanisms whereby HIV infection impedes successful T cell-mediated control of M. tuberculosis have not been well defined. To further delineate mechanisms whereby HIV impairs protective immunity to M. tuberculosis , we evaluated the frequency, phenotype, and functional capacity of M. tuberculosis -specific CD4 T cells in HIV-infected and HIV-uninfected adults with LTBI. HIV infection was associated with a lower total frequency of cytokine-producing M. tuberculosis -specific CD4 T cells, and preferential depletion of a discrete subset of M. tuberculosis -specific IFN-γ + IL-2 - TNF-α + CD4 T cells. M. tuberculosis -specific CD4 T cells in HIV-infected individuals expressed significantly higher levels of Ki67, compared with HIV-uninfected individuals, thus indicating recent activation and turnover of these cells in vivo. The ex vivo proliferative capacity of M. tuberculosis -specific CD4 T cells was markedly impaired in HIV-infected individuals, compared with HIV-uninfected individuals. Moreover, HIV infection was associated with increased M. tuberculosis Ag-induced CD4 T cell death ex vivo, indicating a possible mechanism contributing to impaired proliferative capacity of M. tuberculosis -specific CD4 T cells in HIV-infected individuals. These data provide new insights into the parameters of M. tuberculosis -specific CD4 T cell immunity that are impaired in HIV-infected individuals with LTBI, which may contribute to their increased risk of developing active tuberculosis disease. Copyright © 2017 by The American Association of Immunologists, Inc.

Amino acid containing thapsigargin analogues deplete androgen receptor protein via synthesis inhibition and induce the death of prostate cancer cells

DEFF Research Database (Denmark)

Griend, Donald J Vander; Antony, Lizamma; Dalrymple, Susan L

2009-01-01

There are quantitative and/or qualitative mechanisms allowing androgen receptor (AR) growth signaling in androgen ablation refractory prostate cancer cells. Regardless of the mechanism, agents that deplete AR protein expression prevent such AR growth signaling. Thapsigargin (TG) is a highly cell......-penetrant sequiterpene-lactone that once inside cells inhibits (IC(50), approximately 10 nmol/L) critically important housekeeping SERCA 2b calcium pumps in the endoplasmic reticulum. Using a series of five genetically diverse androgen ablation refractory human prostate cancer lines (LNCaP, LAPC-4, VCaP, MDA-PCa-2b......-specific proteases, such as prostate-specific antigen and prostate-specific membrane antigen, or cancer-specific proteases, such as fibroblast activation protein, so that toxicity of these prodrugs is selectively targeted to metastatic sites of prostate cancer. Based on these results, these prodrugs are undergoing...

A millifluidic study of cell-to-cell heterogeneity in growth-rate and cell-division capability in populations of isogenic cells of Chlamydomonas reinhardtii.

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Shima P Damodaran

Full Text Available To address possible cell-to-cell heterogeneity in growth dynamics of isogenic cell populations of Chlamydomonas reinhardtii, we developed a millifluidic drop-based device that not only allows the analysis of populations grown from single cells over periods of a week, but is also able to sort and collect drops of interest, containing viable and healthy cells, which can be used for further experimentation. In this study, we used isogenic algal cells that were first synchronized in mixotrophic growth conditions. We show that these synchronized cells, when placed in droplets and kept in mixotrophic growth conditions, exhibit mostly homogeneous growth statistics, but with two distinct subpopulations: a major population with a short doubling-time (fast-growers and a significant subpopulation of slowly dividing cells (slow-growers. These observations suggest that algal cells from an isogenic population may be present in either of two states, a state of restricted division and a state of active division. When isogenic cells were allowed to propagate for about 1000 generations on solid agar plates, they displayed an increased heterogeneity in their growth dynamics. Although we could still identify the original populations of slow- and fast-growers, drops inoculated with a single progenitor cell now displayed a wider diversity of doubling-times. Moreover, populations dividing with the same growth-rate often reached different cell numbers in stationary phase, suggesting that the progenitor cells differed in the number of cell divisions they could undertake. We discuss possible explanations for these cell-to-cell heterogeneities in growth dynamics, such as mutations, differential aging or stochastic variations in metabolites and macromolecules yielding molecular switches, in the light of single-cell heterogeneities that have been reported among isogenic populations of other eu- and prokaryotes.

Ego Depletion Impairs Implicit Learning

Science.gov (United States)

Thompson, Kelsey R.; Sanchez, Daniel J.; Wesley, Abigail H.; Reber, Paul J.

2014-01-01

Implicit skill learning occurs incidentally and without conscious awareness of what is learned. However, the rate and effectiveness of learning may still be affected by decreased availability of central processing resources. Dual-task experiments have generally found impairments in implicit learning, however, these studies have also shown that certain characteristics of the secondary task (e.g., timing) can complicate the interpretation of these results. To avoid this problem, the current experiments used a novel method to impose resource constraints prior to engaging in skill learning. Ego depletion theory states that humans possess a limited store of cognitive resources that, when depleted, results in deficits in self-regulation and cognitive control. In a first experiment, we used a standard ego depletion manipulation prior to performance of the Serial Interception Sequence Learning (SISL) task. Depleted participants exhibited poorer test performance than did non-depleted controls, indicating that reducing available executive resources may adversely affect implicit sequence learning, expression of sequence knowledge, or both. In a second experiment, depletion was administered either prior to or after training. Participants who reported higher levels of depletion before or after training again showed less sequence-specific knowledge on the post-training assessment. However, the results did not allow for clear separation of ego depletion effects on learning versus subsequent sequence-specific performance. These results indicate that performance on an implicitly learned sequence can be impaired by a reduction in executive resources, in spite of learning taking place outside of awareness and without conscious intent. PMID:25275517

Ego depletion impairs implicit learning.

Directory of Open Access Journals (Sweden)

Kelsey R Thompson

Full Text Available Implicit skill learning occurs incidentally and without conscious awareness of what is learned. However, the rate and effectiveness of learning may still be affected by decreased availability of central processing resources. Dual-task experiments have generally found impairments in implicit learning, however, these studies have also shown that certain characteristics of the secondary task (e.g., timing can complicate the interpretation of these results. To avoid this problem, the current experiments used a novel method to impose resource constraints prior to engaging in skill learning. Ego depletion theory states that humans possess a limited store of cognitive resources that, when depleted, results in deficits in self-regulation and cognitive control. In a first experiment, we used a standard ego depletion manipulation prior to performance of the Serial Interception Sequence Learning (SISL task. Depleted participants exhibited poorer test performance than did non-depleted controls, indicating that reducing available executive resources may adversely affect implicit sequence learning, expression of sequence knowledge, or both. In a second experiment, depletion was administered either prior to or after training. Participants who reported higher levels of depletion before or after training again showed less sequence-specific knowledge on the post-training assessment. However, the results did not allow for clear separation of ego depletion effects on learning versus subsequent sequence-specific performance. These results indicate that performance on an implicitly learned sequence can be impaired by a reduction in executive resources, in spite of learning taking place outside of awareness and without conscious intent.

Ego depletion impairs implicit learning.

Science.gov (United States)

Thompson, Kelsey R; Sanchez, Daniel J; Wesley, Abigail H; Reber, Paul J

2014-01-01

Implicit skill learning occurs incidentally and without conscious awareness of what is learned. However, the rate and effectiveness of learning may still be affected by decreased availability of central processing resources. Dual-task experiments have generally found impairments in implicit learning, however, these studies have also shown that certain characteristics of the secondary task (e.g., timing) can complicate the interpretation of these results. To avoid this problem, the current experiments used a novel method to impose resource constraints prior to engaging in skill learning. Ego depletion theory states that humans possess a limited store of cognitive resources that, when depleted, results in deficits in self-regulation and cognitive control. In a first experiment, we used a standard ego depletion manipulation prior to performance of the Serial Interception Sequence Learning (SISL) task. Depleted participants exhibited poorer test performance than did non-depleted controls, indicating that reducing available executive resources may adversely affect implicit sequence learning, expression of sequence knowledge, or both. In a second experiment, depletion was administered either prior to or after training. Participants who reported higher levels of depletion before or after training again showed less sequence-specific knowledge on the post-training assessment. However, the results did not allow for clear separation of ego depletion effects on learning versus subsequent sequence-specific performance. These results indicate that performance on an implicitly learned sequence can be impaired by a reduction in executive resources, in spite of learning taking place outside of awareness and without conscious intent.

Exposure to nature counteracts aggression after depletion.

Science.gov (United States)

Wang, Yan; She, Yihan; Colarelli, Stephen M; Fang, Yuan; Meng, Hui; Chen, Qiuju; Zhang, Xin; Zhu, Hongwei

2018-01-01

Acts of self-control are more likely to fail after previous exertion of self-control, known as the ego depletion effect. Research has shown that depleted participants behave more aggressively than non-depleted participants, especially after being provoked. Although exposure to nature (e.g., a walk in the park) has been predicted to replenish resources common to executive functioning and self-control, the extent to which exposure to nature may counteract the depletion effect on aggression has yet to be determined. The present study investigated the effects of exposure to nature on aggression following depletion. Aggression was measured by the intensity of noise blasts participants delivered to an ostensible opponent in a competition reaction-time task. As predicted, an interaction occurred between depletion and environmental manipulations for provoked aggression. Specifically, depleted participants behaved more aggressively in response to provocation than non-depleted participants in the urban condition. However, provoked aggression did not differ between depleted and non-depleted participants in the natural condition. Moreover, within the depletion condition, participants in the natural condition had lower levels of provoked aggression than participants in the urban condition. This study suggests that a brief period of nature exposure may restore self-control and help depleted people regain control over aggressive urges. © 2017 Wiley Periodicals, Inc.

Depletion of eIF4G from yeast cells narrows the range of translational efficiencies genome-wide

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Hinnebusch Alan G

2011-01-01

Full Text Available Abstract Background Eukaryotic translation initiation factor 4G (eIF4G is thought to influence the translational efficiencies of cellular mRNAs by its roles in forming an eIF4F-mRNA-PABP mRNP that is competent for attachment of the 43S preinitiation complex, and in scanning through structured 5' UTR sequences. We have tested this hypothesis by determining the effects of genetically depleting eIF4G from yeast cells on global translational efficiencies (TEs, using gene expression microarrays to measure the abundance of mRNA in polysomes relative to total mRNA for ~5900 genes. Results Although depletion of eIF4G is lethal and reduces protein synthesis by ~75%, it had small effects (less than a factor of 1.5 on the relative TE of most genes. Within these limits, however, depleting eIF4G narrowed the range of translational efficiencies genome-wide, with mRNAs of better than average TE being translated relatively worse, and mRNAs with lower than average TE being translated relatively better. Surprisingly, the fraction of mRNAs most dependent on eIF4G display an average 5' UTR length at or below the mean for all yeast genes. Conclusions This finding suggests that eIF4G is more critical for ribosome attachment to mRNAs than for scanning long, structured 5' UTRs. Our results also indicate that eIF4G, and the closed-loop mRNP it assembles with the m7 G cap- and poly(A-binding factors (eIF4E and PABP, is not essential for translation of most (if not all mRNAs but enhances the differentiation of translational efficiencies genome-wide.

Specific Depletion of Ly6Chi Inflammatory Monocytes Prevents Immunopathology in Experimental Cerebral Malaria

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Kuepper, Janina M.; Biswas, Aindrila; Djie-Maletz, Andrea; Limmer, Andreas; van Rooijen, Nico; Mack, Matthias; Hoerauf, Achim; Dunay, Ildiko Rita

2015-01-01

Plasmodium berghei ANKA (PbA) infection of C57BL/6 mice leads to experimental cerebral malaria (ECM) that is commonly associated with serious T cell mediated damage. In other parasitic infection models, inflammatory monocytes have been shown to regulate Th1 responses but their role in ECM remains poorly defined, whereas neutrophils are reported to contribute to ECM immune pathology. Making use of the recent development of specific monoclonal antibodies (mAb), we depleted in vivo Ly6Chi inflammatory monocytes (by anti-CCR2), Ly6G+ neutrophils (by anti-Ly6G) or both cell types (by anti-Gr1) during infection with Ovalbumin-transgenic PbA parasites (PbTg). Notably, the application of anti-Gr1 or anti-CCR2 but not anti-Ly6G antibodies into PbTg-infected mice prevented ECM development. In addition, depletion of Ly6Chi inflammatory monocytes but not neutrophils led to decreased IFNγ levels and IFNγ+CD8+ T effector cells in the brain. Importantly, anti-CCR2 mAb injection did not prevent the generation of PbTg-specific T cell responses in the periphery, whereas anti-Gr1 mAb injection strongly diminished T cell frequencies and CTL responses. In conclusion, the specific depletion of Ly6Chi inflammatory monocytes attenuated brain inflammation and immune cell recruitment to the CNS, which prevented ECM following Plasmodium infection, pointing out a substantial role of Ly6C+ monocytes in ECM inflammatory processes. PMID:25884830

Trail networks formed by populations of immune cells

International Nuclear Information System (INIS)

Yang, Taeseok Daniel; Kwon, Tae Goo; Park, Jin-sung; Lee, Kyoung J

2014-01-01

Populations of biological cells that communicate with each other can organize themselves to generate large-scale patterns. Examples can be found in diverse systems, ranging from developing embryos, cardiac tissues, chemotaxing ameba and swirling bacteria. The similarity, often shared by the patterns, suggests the existence of some general governing principle. On the other hand, rich diversity and system-specific properties are exhibited, depending on the type of involved cells and the nature of their interactions. The study on the similarity and the diversity constitutes a rapidly growing field of research. Here, we introduce a new class of self-organized patterns of cell populations that we term as ‘cellular trail networks’. They were observed with populations of rat microglia, the immune cells of the brain and the experimental evidence suggested that haptotaxis is the key element responsible for them. The essential features of the observed patterns are well captured by the mathematical model cells that actively crawl and interact with each other through a decomposing but non-diffusing chemical attractant laid down by the cells. Our finding suggests an unusual mechanism of socially cooperative long-range signaling for the crawling immune cells. (paper)

Requirement for CD40 ligand, CD4(+) T cells, and B cells in an infectious mononucleosis-like syndrome

DEFF Research Database (Denmark)

Brooks, J W; Hamilton-Easton, A M; Christensen, J P

1999-01-01

(+) CD8(+) population that is found in mice with different major histocompatibility complex (MHC) haplotypes. Aspects of the CD8(+)-T-cell response are substantially modified in mice that lack B cells, CD4(+) T cells, or the CD40 ligand (CD40L). The B-cell-deficient mice show no increase in Vbeta4(+) CD8......(+) T cells. Similar abrogation of the Vbeta4(+) CD8(+) response is seen following antibody-mediated depletion of the CD4(+) subset, through the numbers of CD8(+) CD62L(lo) cells are still significantly elevated. Virus-specific CD4(+)-T-cell frequencies are minimal in the CD40L(-/-) mice, and the Vbeta4......(+) CD8(+) population remains unexpanded. Apparently B-cell-CD4(+)-T-cell interactions play a part in the gammaHV-68 induction of both splenomegaly and non-MHC-restricted Vbeta4(+) CD8(+)-T-cell expansion....

A microarray analysis of two distinct lymphatic endothelial cell populations

Directory of Open Access Journals (Sweden)

Bernhard Schweighofer

2015-06-01

Full Text Available We have recently identified lymphatic endothelial cells (LECs to form two morphologically different populations, exhibiting significantly different surface protein expression levels of podoplanin, a major surface marker for this cell type. In vitro shockwave treatment (IVSWT of LECs resulted in enrichment of the podoplaninhigh cell population and was accompanied by markedly increased cell proliferation, as well as 2D and 3D migration. Gene expression profiles of these distinct populations were established using Affymetrix microarray analyses. Here we provide additional details about our dataset (NCBI GEO accession number GSE62510 and describe how we analyzed the data to identify differently expressed genes in these two LEC populations.

Ascorbate regulates haematopoietic stem cell function and leukaemogenesis.

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Agathocleous, Michalis; Meacham, Corbin E; Burgess, Rebecca J; Piskounova, Elena; Zhao, Zhiyu; Crane, Genevieve M; Cowin, Brianna L; Bruner, Emily; Murphy, Malea M; Chen, Weina; Spangrude, Gerald J; Hu, Zeping; DeBerardinis, Ralph J; Morrison, Sean J

2017-09-28

Stem-cell fate can be influenced by metabolite levels in culture, but it is not known whether physiological variations in metabolite levels in normal tissues regulate stem-cell function in vivo. Here we describe a metabolomics method for the analysis of rare cell populations isolated directly from tissues and use it to compare mouse haematopoietic stem cells (HSCs) to restricted haematopoietic progenitors. Each haematopoietic cell type had a distinct metabolic signature. Human and mouse HSCs had unusually high levels of ascorbate, which decreased with differentiation. Systemic ascorbate depletion in mice increased HSC frequency and function, in part by reducing the function of Tet2, a dioxygenase tumour suppressor. Ascorbate depletion cooperated with Flt3 internal tandem duplication (Flt3 ITD ) leukaemic mutations to accelerate leukaemogenesis, through cell-autonomous and possibly non-cell-autonomous mechanisms, in a manner that was reversed by dietary ascorbate. Ascorbate acted cell-autonomously to negatively regulate HSC function and myelopoiesis through Tet2-dependent and Tet2-independent mechanisms. Ascorbate therefore accumulates within HSCs to promote Tet activity in vivo, limiting HSC frequency and suppressing leukaemogenesis.

ARTD1/PARP1 Negatively Regulates Glycolysis by Inhibiting Hexokinase 1 Independent of NAD+ Depletion

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Elise Fouquerel

2014-09-01

Full Text Available ARTD1 (PARP1 is a key enzyme involved in DNA repair through the synthesis of poly(ADP-ribose (PAR in response to strand breaks, and it plays an important role in cell death following excessive DNA damage. ARTD1-induced cell death is associated with NAD+ depletion and ATP loss; however, the molecular mechanism of ARTD1-mediated energy collapse remains elusive. Using real-time metabolic measurements, we compared the effects of ARTD1 activation and direct NAD+ depletion. We found that ARTD1-mediated PAR synthesis, but not direct NAD+ depletion, resulted in a block to glycolysis and ATP loss. We then established a proteomics-based PAR interactome after DNA damage and identified hexokinase 1 (HK1 as a PAR binding protein. HK1 activity is suppressed following nuclear ARTD1 activation and binding by PAR. These findings help explain how prolonged activation of ARTD1 triggers energy collapse and cell death, revealing insight into the importance of nucleus-to-mitochondria communication via ARTD1 activation.

Rates of Blood Formation and of Blood-Cell Depletion and Recovery after Irradiation

Energy Technology Data Exchange (ETDEWEB)

Patt, H. M. [University of California, San Francisco, CA (United States)

1967-07-15

During the past decade or so, the study of radiation effects on cell renewal systems has moved more and more from the realm of description to that of analysis. There are several reasons for this development and paramount among these has been the introduction of techniques for study of the life history of organized cell populations, and the radiation survival kinetics of their components . In this paper I wish first to examine some basic parameters of normal haematopoiesis that are pertinent to understanding' radiation effects, and then to consider the radiosensitivity of blood cells as individual entities and as components of organized systems.

Depletion of regulatory T cells leads to an exacerbation of delayed-type hypersensitivity arthritis in C57BL/6 mice that can be counteracted by IL-17 blockade

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Atkinson, Sara Marie; Hoffmann, Ute; Hamann, Alf; Bach, Emil; Danneskiold-Samsøe, Niels Banhos; Kristiansen, Karsten; Serikawa, Kyle; Fox, Brian; Kruse, Kim; Haase, Claus; Skov, Søren; Nansen, Anneline

2016-01-01

ABSTRACT Rodent models of arthritis have been extensively used in the elucidation of rheumatoid arthritis (RA) pathogenesis and are instrumental in the development of therapeutic strategies. Here we utilise delayed-type hypersensitivity arthritis (DTHA), a model in C57BL/6 mice affecting one paw with synchronised onset, 100% penetrance and low variation. We investigate the role of regulatory T cells (Tregs) in DTHA through selective depletion of Tregs and the role of IL-17 in connection with Treg depletion. Given the relevance of Tregs in RA, and the possibility of developing Treg-directed therapies, this approach could be relevant for advancing the understanding of Tregs in inflammatory arthritis. Selective depletion of Tregs was achieved using a Foxp3-DTR-eGFP mouse, which expresses the diphtheria toxin receptor (DTR) and enhanced green fluorescent protein (eGFP) under control of the Foxp3 gene. Anti-IL-17 monoclonal antibody (mAb) was used for IL-17 blockade. Numbers and activation of Tregs increased in the paw and its draining lymph node in DTHA, and depletion of Tregs resulted in exacerbation of disease as shown by increased paw swelling, increased infiltration of inflammatory cells, increased bone remodelling and increased production of inflammatory mediators, as well as increased production of anti-citrullinated protein antibodies. Anti-IL-17 mAb treatment demonstrated that IL-17 is important for disease severity in both the presence and absence of Tregs, and that IL-17 blockade is able to rescue mice from the exacerbated disease caused by Treg depletion and caused a reduction in RANKL, IL-6 and the number of neutrophils. We show that Tregs are important for the containment of inflammation and bone remodelling in DTHA. To our knowledge, this is the first study using the Foxp3-DTR-eGFP mouse on a C57BL/6 background for Treg depletion in an arthritis model, and we here demonstrate the usefulness of the approach to study the role of Tregs and IL-17 in arthritis

The Physical Origin of Long Gas Depletion Times in Galaxies

Energy Technology Data Exchange (ETDEWEB)

Semenov, Vadim A.; Kravtsov, Andrey V.; Gnedin, Nickolay Y.

2017-08-18

We present a model that elucidates why gas depletion times in galaxies are long compared to the time scales of the processes driving the evolution of the interstellar medium. We show that global depletion times are not set by any "bottleneck" in the process of gas evolution towards the star-forming state. Instead, depletion times are long because star-forming gas converts only a small fraction of its mass into stars before it is dispersed by dynamical and feedback processes. Thus, complete depletion requires that gas transitions between star-forming and non-star-forming states multiple times. Our model does not rely on the assumption of equilibrium and can be used to interpret trends of depletion times with the properties of observed galaxies and the parameters of star formation and feedback recipes in galaxy simulations. In particular, the model explains the mechanism by which feedback self-regulates star formation rate in simulations and makes it insensitive to the local star formation efficiency. We illustrate our model using the results of an isolated $L_*$-sized disk galaxy simulation that reproduces the observed Kennicutt-Schmidt relation for both molecular and atomic gas. Interestingly, the relation for molecular gas is close to linear on kiloparsec scales, even though a non-linear relation is adopted in simulation cells. This difference is due to stellar feedback, which breaks the self-similar scaling of the gas density PDF with the average gas surface density.

Clec9a-Mediated Ablation of Conventional Dendritic Cells Suggests a Lymphoid Path to Generating Dendritic Cells In Vivo

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Johanna Salvermoser

2018-04-01

Full Text Available Conventional dendritic cells (cDCs are versatile activators of immune responses that develop as part of the myeloid lineage downstream of hematopoietic stem cells. We have recently shown that in mice precursors of cDCs, but not of other leukocytes, are marked by expression of DNGR-1/CLEC9A. To genetically deplete DNGR-1-expressing cDC precursors and their progeny, we crossed Clec9a-Cre mice to Rosa-lox-STOP-lox-diphtheria toxin (DTA mice. These mice develop signs of age-dependent myeloproliferative disease, as has been observed in other DC-deficient mouse models. However, despite efficient depletion of cDC progenitors in these mice, cells with phenotypic characteristics of cDCs populate the spleen. These cells are functionally and transcriptionally similar to cDCs in wild type control mice but show somatic rearrangements of Ig-heavy chain genes, characteristic of lymphoid origin cells. Our studies reveal a previously unappreciated developmental heterogeneity of cDCs and suggest that the lymphoid lineage can generate cells with features of cDCs when myeloid cDC progenitors are impaired.

Kinetics of depletion interactions

NARCIS (Netherlands)

Vliegenthart, G.A.; Schoot, van der P.P.A.M.

2003-01-01

Depletion interactions between colloidal particles dispersed in a fluid medium are effective interactions induced by the presence of other types of colloid. They are not instantaneous but built up in time. We show by means of Brownian dynamics simulations that the static (mean-field) depletion force

Proliferation studies of the endothelial and smooth muscle cells of the mouse mesentery after irradiation

International Nuclear Information System (INIS)

Hirst, D.G.; Denekamp, J.; Hobson, B.

1980-01-01

A continuous tritium labelling technique was employed to study the effects of external β-radiation on the proliferation of endothelial cells and smooth muscle cells in the mesenteric arterioles of mice. Calculations showed very long turnover times for the two cell populations in control animals (> 2 years for endothelium and > 3 years for smooth muscle). After single doses of 20 and 45 Gy, no significant increase in endothelial proliferation was seen except at 3 weeks. No significant increase in labelling was observed in smooth muscle up to 48 weeks after irradiation. These labelling data have been compared with the pattern of cell depletion of the irradiated endothelium. It was concluded that the depletion was much earlier than expected for a slowly proliferating tissue, if all the cells were cycling very slowly. Such an early depletion is, however, consistent with cell death resulting from a small proportion of the cells having a short cell cycle. The recovery of the endothelial cell numbers between 9 and 12 months was not accompanied by a rise in the fraction of labelled cells. It is suggested that repopulation may occur from outside the treated area. (author)