Characterization of acute undifferentiated leukemia by combined analysis of plasma membrane-associated gamma-glutamyltranspeptidase and soluble terminal transferase.

PubMed

Heumann, D; Losa, G; Barras, C; Morell, A; von Fliedner, V

1985-08-01

gamma-Glutamyltranspeptidase (gamma-GT) is a plasma membrane-associated enzyme present in blasts of certain acute leukemias. We analyzed 90 cases of undifferentiated and differentiated acute leukemias for gamma-GT, using a colorimetric assay. Blasts of all patients with common acute lymphoblastic leukemia (ALL) and T-ALL were negative for gamma-GT (less than 5 units). In contrast, gamma-GT was significantly elevated in acute myeloblastic or monoblastic leukemia blasts (P less than .001). In 16 cases of acute undifferentiated leukemia (AUL) studied, the levels of gamma-GT ranged from 0 to 93 units; in eight cases, gamma-GT was positive (greater than 5 units), and six of these had 2% to 5% Sudan black-positive leukemic cells in the blast-enriched suspension. Combined gamma-GT/TdT analysis revealed that both enzyme markers were mutually exclusive in 75% of AUL cases, suggesting that gamma-GT+/TdT-blasts are of nonlymphoid origin, and gamma-GT-/TdT+ blasts are of lymphoid origin. Two cases were devoid of both enzyme activities and could represent truly undifferentiated leukemia. Thus, combined gamma-GT/TdT analysis underlines the heterogeneity of AUL and appears to be useful in defining the lineage commitment of undifferentiated leukemic blasts.

Posterior midgut epithelial cells differ in their organization of the membrane skeleton from other drosophila epithelia.

PubMed

Baumann, O

2001-11-01

In epithelial cells, the various components of the membrane skeleton are segregated within specialized subregions of the plasma membrane, thus contributing to the development and stabilization of cell surface polarity. It has previously been shown that, in various Drosophila epithelia, the membrane skeleton components ankyrin and alphabeta-spectrin reside at the lateral surface, whereas alphabeta(H)-spectrin is restricted to the apical domain. By use of confocal immunofluorescence microscopy, the present study characterizes the membrane skeleton of epithelial cells in the posterior midgut, leading to a number of unexpected results. First, ankyrin and alphabeta-spectrin are not detected on the entire lateral surface but appear to be restricted to the apicolateral area, codistributing with fasciclin III at smooth septate junctions. The presumptive ankyrin-binding proteins neuroglian and Na(+),K(+)-ATPase, however, do not colocalize with ankyrin. Second, alphabeta(H)-spectrin is enriched at the apical domain but is also present in lower amounts on the entire lateral surface, colocalizing apicolaterally with ankyrin/alphabeta-spectrin. Finally, despite the absence of zonulae adherentes, F-actin, beta(H)-spectrin, and nonmuscle myosin-II are enriched in the midlateral region. Thus, the model established for the organization of the membrane skeleton in Drosophila epithelia does not hold for the posterior midgut, and there is quite some variability between the different epithelia with respect to the organization of the membrane skeleton. Copyright 2001 Academic Press.

ovoD Co-selection: A Method for Enriching CRISPR/Cas9-Edited Alleles in Drosophila.

PubMed

Ewen-Campen, Ben; Perrimon, Norbert

2018-06-22

Screening for successful CRISPR/Cas9 editing events remains a time consuming technical bottleneck in the field of Drosophila genome editing. This step can be particularly laborious for events that do not cause a visible phenotype, or those which occur at relatively low frequency. A promising strategy to enrich for desired CRISPR events is to co-select for an independent CRISPR event that produces an easily detectable phenotype. Here, we describe a simple negative co-selection strategy involving CRISPR-editing of a dominant female sterile allele, ovo D1 In this system (" ovo D co-selection"), the only functional germ cells in injected females are those that have been edited at the ovo D1 locus, and thus all offspring of these flies have undergone editing of at least one locus. We demonstrate that ovo D co-selection can be used to enrich for knock-out mutagenesis via nonhomologous end-joining (NHEJ), and for knock-in alleles via homology-directed repair (HDR). Altogether, our results demonstrate that ovoD co-selection reduces the amount of screening necessary to isolate desired CRISPR events in Drosophila. Copyright © 2018, G3: Genes, Genomes, Genetics.

Control of non-apoptotic nurse cell death by engulfment genes in Drosophila.

PubMed

Timmons, Allison K; Mondragon, Albert A; Meehan, Tracy L; McCall, Kimberly

2017-04-03

Programmed cell death occurs as a normal part of oocyte development in Drosophila. For each egg that is formed, 15 germline-derived nurse cells transfer their cytoplasmic contents into the oocyte and die. Disruption of apoptosis or autophagy only partially inhibits the death of the nurse cells, indicating that other mechanisms significantly contribute to nurse cell death. Recently, we demonstrated that the surrounding stretch follicle cells non-autonomously promote nurse cell death during late oogenesis and that phagocytosis genes including draper, ced-12, and the JNK pathway are crucial for this process. When phagocytosis genes are inhibited in the follicle cells, events specifically associated with death of the nurse cells are impaired. Death of the nurse cells is not completely blocked in draper mutants, suggesting that other engulfment receptors are involved. Indeed, we found that the integrin subunit, αPS3, is enriched on stretch follicle cells during late oogenesis and is required for elimination of the nurse cells. Moreover, double mutant analysis revealed that integrins act in parallel to draper. Death of nurse cells in the Drosophila ovary is a unique example of programmed cell death that is both non-apoptotic and non-cell autonomously controlled.

The role of MOF in the ionizing radiation response is conserved in Drosophila melanogaster

PubMed Central

Bhadra, Manika P.; Horikoshi, Nobuo; Pushpavallipvalli, Sreerangam NCVL; Sarkar, Arpita; Bag, Indira; Krishnan, Anita; Lucchesi, John C.; Kumar, Rakesh; Yang, Qin; Pandita, Raj K.; Singh, Mayank; Bhadra, Utpal; Eissenberg, Joel C.; Pandita, Tej K.

2014-01-01

In Drosophila, males absent on the first (MOF) acetylates histone H4 at lysine 16 (H4K16ac). This acetylation mark is highly enriched on the male X chromosome and is required for dosage compensation in Drosophila but not utilized for such in mammals. Recently, we and others reported that mammalian MOF, through H4K16ac, has a critical role at multiple stages in the DNA damage response (DDR) and double-strand break repair pathways. The goal of this study was to test whether mof is similarly required for the response to ionizing radiation (IR) in Drosophila. We report that Drosophila mof mutations in males and females, as well as mof knockdown in SL-2 cells, reduce post-irradiation survival. MOF depletion in SL-2 cells also results in an elevated frequency of metaphases with chromosomal aberrations, suggesting that MOF is involved in DDR. Mutation in Drosophila mof also results in a defective mitotic checkpoint, enhanced apoptosis, and a defective p53 response post-irradiation. In addition, IR exposure enhanced H4K16ac levels in Drosophila as it also does in mammals. These results are the first to demonstrate a requirement for MOF in the whole animal IR response and suggest that the role of MOF in the response to IR is conserved between Drosophila and mammals. PMID:22072291

Internal epithelia in Drosophila display rudimentary competence to form cytoplasmic networks of transgenic human vimentin.

PubMed

Gullmets, Josef; Torvaldson, Elin; Lindqvist, Julia; Imanishi, Susumu Y; Taimen, Pekka; Meinander, Annika; Eriksson, John E

2017-12-01

Cytoplasmic intermediate filaments (cIFs) are found in all eumetazoans, except arthropods. To investigate the compatibility of cIFs in arthropods, we expressed human vimentin (hVim), a cIF with filament-forming capacity in vertebrate cells and tissues, transgenically in Drosophila Transgenic hVim could be recovered from whole-fly lysates by using a standard procedure for intermediate filament (IF) extraction. When this procedure was used to test for the possible presence of IF-like proteins in flies, only lamins and tropomyosin were observed in IF-enriched extracts, thereby providing biochemical reinforcement to the paradigm that arthropods lack cIFs. In Drosophila , transgenic hVim was unable to form filament networks in S2 cells and mesenchymal tissues; however, cage-like vimentin structures could be observed around the nuclei in internal epithelia, which suggests that Drosophila retains selective competence for filament formation. Taken together, our results imply that although the filament network formation competence is partially lost in Drosophila , a rudimentary filament network formation ability remains in epithelial cells. As a result of the observed selective competence for cIF assembly in Drosophila , we hypothesize that internal epithelial cIFs were the last cIFs to disappear from arthropods.-Gullmets, J., Torvaldson, E., Lindqvist, J., Imanishi, S. Y., Taimen, P., Meinander, A., Eriksson, J. E. Internal epithelia in Drosophila display rudimentary competence to form cytoplasmic networks of transgenic human vimentin. © FASEB.

Mood stabilizing drugs regulate transcription of immune, neuronal and metabolic pathway genes in Drosophila.

PubMed

Herteleer, L; Zwarts, L; Hens, K; Forero, D; Del-Favero, J; Callaerts, P

2016-05-01

Lithium and valproate (VPA) are drugs used in the management of bipolar disorder. Even though they reportedly act on various pathways, the transcriptional targets relevant for disease mechanism and therapeutic effect remain unclear. Furthermore, multiple studies used lymphoblasts of bipolar patients as a cellular proxy, but it remains unclear whether peripheral cells provide a good readout for the effects of these drugs in the brain. We used Drosophila culture cells and adult flies to analyze the transcriptional effects of lithium and VPA and define mechanistic pathways. Transcriptional profiles were determined for Drosophila S2-cells and adult fly heads following lithium or VPA treatment. Gene ontology categories were identified using the DAVID functional annotation tool with a cut-off of p < 0.05. Significantly enriched GO terms were clustered using REVIGO and DAVID functional annotation clustering. Significance of overlap between transcript lists was determined with a Fisher's exact hypergeometric test. Treatment of cultured cells and adult flies with lithium and VPA induces transcriptional responses in genes with similar ontology, with as most prominent immune response, neuronal development, neuronal function, and metabolism. (i) Transcriptional effects of lithium and VPA in Drosophila S2 cells and heads show significant overlap. (ii) The overlap between transcriptional alterations in peripheral versus neuronal cells at the single gene level is negligible, but at the gene ontology and pathway level considerable overlap can be found. (iii) Lithium and VPA act on evolutionarily conserved pathways in Drosophila and mammalian models.

A Model of the Spatio-temporal Dynamics of Drosophila Eye Disc Development.

PubMed

Fried, Patrick; Sánchez-Aragón, Máximo; Aguilar-Hidalgo, Daniel; Lehtinen, Birgitta; Casares, Fernando; Iber, Dagmar

2016-09-01

Patterning and growth are linked during early development and have to be tightly controlled to result in a functional tissue or organ. During the development of the Drosophila eye, this linkage is particularly clear: the growth of the eye primordium mainly results from proliferating cells ahead of the morphogenetic furrow (MF), a moving signaling wave that sweeps across the tissue from the posterior to the anterior side, that induces proliferating cells anterior to it to differentiate and become cell cycle quiescent in its wake. Therefore, final eye disc size depends on the proliferation rate of undifferentiated cells and on the speed with which the MF sweeps across the eye disc. We developed a spatio-temporal model of the growing eye disc based on the regulatory interactions controlled by the signals Decapentaplegic (Dpp), Hedgehog (Hh) and the transcription factor Homothorax (Hth) and explored how the signaling patterns affect the movement of the MF and impact on eye disc growth. We used published and new quantitative data to parameterize the model. In particular, two crucial parameter values, the degradation rate of Hth and the diffusion coefficient of Hh, were measured. The model is able to reproduce the linear movement of the MF and the termination of growth of the primordium. We further show that the model can explain several mutant phenotypes, but fails to reproduce the previously observed scaling of the Dpp gradient in the anterior compartment.

Short-term in-vitro culture of goat enriched spermatogonial stem cells using different serum concentrations.

PubMed

Bahadorani, M; Hosseini, S M; Abedi, P; Hajian, M; Hosseini, S E; Vahdati, A; Baharvand, H; Nasr-Esfahani, Mohammad H

2012-01-01

To investigate the effect of serum supplementing on short-term culture, fate determination and gene expression of goat spermatogonial stem cells (SSCs). Crude testicular cells were plated over Datura-Stramonium Agglutinin (DSA) for 1 h, and non-adhering cells were cultured in the presence of different serum concentrations (1, 5, 10, and 15%) for 7 days in a highly enriched medium initially developed in mice. Colonies developed in each group were used for the assessment of morphology, immunocytochemistry, and gene expression. Brief incubation of testicular cells with DSA resulted in a significant increase in the number of cells that expressed the germ cell marker (VASA). The expression of THY1, a specific marker of undifferentiated spermatogonia, was significantly higher in colonies developed in the presence of 1% rather than 5, 10 and 15% serum. Goat SSCs could proliferate and maintain in SSC culture media for 1 week at serum concentrations as low as 1%, while higher concentrations had detrimental effects on SSC culture/expansion.

Morphological Analysis of Live Undifferentiated Cells Derived from Induced Pluripotent Stem Cells.

PubMed

Osawa, Yukihiko; Miyamoto, Tomoyuki; Ohno, Setsuyo; Ohno, Eiji

2018-01-01

Induced pluripotent stem (iPS) cells possess pluripotency and self-renewal ability. Therefore, iPS cells are expected to be useful in regenerative medicine. However, iPS cells form malignant immature teratomas after transplantation into animals, even after differentiation induction. It has been suggested that undifferentiated cells expressing Nanog that remain after differentiation induction are responsible for teratoma formation. Various methods of removing these undifferentiated cells have therefore been investigated, but few methods involve morphological approaches, which may induce less cell damage. In addition, for cells derived from iPS cells to be applied in regenerative medicine, they must be alive. However, detailed morphological analysis of live undifferentiated cells has not been performed. For the above reasons, we assessed the morphological features of live undifferentiated cells remaining after differentiation induction as a basic investigation into the clinical application of iPS cells. As a result, live undifferentiated cells remaining after differentiation induction exhibited a round or oval cytoplasm about 12 μm in diameter and a nucleus. They exhibited nucleo-cytoplasmic (N/C) ratio of about 60% and eccentric nuclei, and they possessed partially granule-like structures in the cytoplasm and prominent nucleoli. Although they were similar to iPS cells, they were smaller than live iPS cells. Furthermore, very small cells were present among undifferentiated cells after differentiation induction. These results suggest that the removal of undifferentiated cells may be possible using the morphological features of live iPS cells and undifferentiated cells after differentiation induction. In addition, this study supports safe regenerative medicine using iPS cells.

Asymmetric Mbc, active Rac1 and F-actin foci in the fusion-competent myoblasts during myoblast fusion in Drosophila

PubMed Central

Haralalka, Shruti; Shelton, Claude; Cartwright, Heather N.; Katzfey, Erin; Janzen, Evan; Abmayr, Susan M.

2011-01-01

Myoblast fusion is an intricate process that is initiated by cell recognition and adhesion, and culminates in cell membrane breakdown and formation of multinucleate syncytia. In the Drosophila embryo, this process occurs asymmetrically between founder cells that pattern the musculature and fusion-competent myoblasts (FCMs) that account for the bulk of the myoblasts. The present studies clarify and amplify current models of myoblast fusion in several important ways. We demonstrate that the non-conventional guanine nucleotide exchange factor (GEF) Mbc plays a fundamental role in the FCMs, where it functions to activate Rac1, but is not required in the founder cells for fusion. Mbc, active Rac1 and F-actin foci are highly enriched in the FCMs, where they localize to the Sns:Kirre junction. Furthermore, Mbc is crucial for the integrity of the F-actin foci and the FCM cytoskeleton, presumably via its activation of Rac1 in these cells. Finally, the local asymmetric distribution of these proteins at adhesion sites is reminiscent of invasive podosomes and, consistent with this model, they are enriched at sites of membrane deformation, where the FCM protrudes into the founder cell/myotube. These data are consistent with models promoting actin polymerization as the driving force for myoblast fusion. PMID:21389053

Molecular requirements for actin-based lamella formation in Drosophila S2 cells

PubMed Central

Rogers, Stephen L.; Wiedemann, Ursula; Stuurman, Nico; Vale, Ronald D.

2003-01-01

Cell migration occurs through the protrusion of the actin-enriched lamella. Here, we investigated the effects of RNAi depletion of ∼90 proteins implicated in actin function on lamella formation in Drosophila S2 cells. Similar to in vitro reconstitution studies of actin-based Listeria movement, we find that lamellae formation requires a relatively small set of proteins that participate in actin nucleation (Arp2/3 and SCAR), barbed end capping (capping protein), filament depolymerization (cofilin and Aip1), and actin monomer binding (profilin and cyclase-associated protein). Lamellae are initiated by parallel and partially redundant signaling pathways involving Rac GTPases and the adaptor protein Nck, which stimulate SCAR, an Arp2/3 activator. We also show that RNAi of three proteins (kette, Abi, and Sra-1) known to copurify with and inhibit SCAR in vitro leads to SCAR degradation, revealing a novel function of this protein complex in SCAR stability. Our results have identified an essential set of proteins involved in actin dynamics during lamella formation in Drosophila S2 cells. PMID:12975351

Notch-Induced Expression of FZD7 Requires Noncanonical NOTCH3 Signaling in Human Breast Epithelial Cells.

PubMed

Bhat, Vasudeva; Sun, Yu Jia; Weger, Steve; Raouf, Afshin

2016-04-01

The evolutionarily conserved Notch and Wnt signaling pathways have demonstrated roles in normal mammary gland development and in breast carcinogenesis. We previously reported that in human mammary gland, signaling through NOTCH3 alone regulates the commitment of the undifferentiated bipotential progenitors to the luminal cell fate, indicating that NOTCH3 may regulate the expression of unique genes apart from the other Notch receptors. In this study, we used gain of function and loss of function experiments and found that a Wnt signaling receptor, Frizzled7 (FZD7), is a unique and nonredundant target of NOTCH3 in human breast epithelial cells. Interestingly, neither the constitutively active forms of NOTCH1-2, 4 nor loss of expression of these receptors were able to alter expression of FZD7 in human breast epithelial cells. We further show that FZD7-expressing cells are found more frequently in the luminal progenitor-enriched subpopulation of cells obtained from breast reduction samples compared with the undifferentiated bipotent progenitors. Also, we show that NOTCH3-induced expression of FZD7 occurs in the absence of CSL (CBF1-Suppressor of Hairless-Lag-1). Our data suggest that noncanonical Notch signaling through NOTCH3 could modulate Wnt signaling via FZD7 and in this way, might be involved in luminal cell differentiation.

Flow-cytometric enrichment of Pacific bluefin tuna type A spermatogonia based on light-scattering properties.

PubMed

Ichida, Kensuke; Kise, Kazuyoshi; Morita, Tetsuro; Yazawa, Ryosuke; Takeuchi, Yutaka; Yoshizaki, Goro

2017-10-01

We previously established surrogate broodstock in which the donor germ cells transplanted into the peritoneal cavities of xenogeneic recipients were capable of developing into functional eggs and sperm in teleost fish. In this transplantation system, only the undifferentiated germ cells such as type A spermatogonia (ASG) or a portion of the ASG population were capable of being incorporated into the genital ridges of the recipients and undergo gametogenesis. Therefore, the use of enriched ASGs can be expected to achieve efficient donor-cell incorporation. Here, we established a method of isolation and enrichment of the ASG of Pacific bluefin tuna using flow cytometry. Whole testicular cell suspensions were fractionated by forward and side scatter properties, following which ASGs were enriched in a fraction in which the forward scatter signal was relatively high and side scatter signal was relatively low. The diameter of sorted cells using the fraction was identical to the size of ASGs observed in histological analysis, and these cells also expressed the vasa gene. In addition, we succeeded in applying this method to several maturation stages of Pacific bluefin tuna. Since this method was based on light-scattering characteristics of ASGs, it can potentially be applied to various teleosts. We expect that this method can contribute to the production of seeds of Pacific bluefin tuna using surrogate broodstock. Copyright © 2017 Elsevier Inc. All rights reserved.

Centriole Remodeling during Spermiogenesis in Drosophila.

PubMed

Khire, Atul; Jo, Kyoung H; Kong, Dong; Akhshi, Tara; Blachon, Stephanie; Cekic, Anthony R; Hynek, Sarah; Ha, Andrew; Loncarek, Jadranka; Mennella, Vito; Avidor-Reiss, Tomer

2016-12-05

The first cell of an animal (zygote) requires centrosomes that are assembled from paternally inherited centrioles and maternally inherited pericentriolar material (PCM) [1]. In some animals, sperm centrioles with typical ultrastructure are the origin of the first centrosomes in the zygote [2-4]. In other animals, however, sperm centrioles lose their proteins and are thought to be degenerated and non-functional during spermiogenesis [5, 6]. Here, we show that the two sperm centrioles (the giant centriole [GC] and the proximal centriole-like structure [PCL]) in Drosophila melanogaster are remodeled during spermiogenesis through protein enrichment and ultrastructure modification in parallel to previously described centrosomal reduction [7]. We found that the ultrastructure of the matured sperm (spermatozoa) centrioles is modified dramatically and that the PCL does not resemble a typical centriole. We also describe a new phenomenon of Poc1 enrichment of the atypical centrioles in the spermatozoa. Using various mutants, protein expression during spermiogenesis, and RNAi knockdown of paternal Poc1, we found that paternal Poc1 enrichment is essential for the formation of centrioles during spermiogenesis and for the formation of centrosomes after fertilization in the zygote. Altogether, these findings demonstrate that the sperm centrioles are remodeled both in their protein composition and in ultrastructure, yet they are functional and are essential for normal embryogenesis in Drosophila. Copyright © 2016 Elsevier Ltd. All rights reserved.

Planar cell polarity controls directional Notch signaling in the Drosophila leg

PubMed Central

Capilla, Amalia; Johnson, Ruth; Daniels, Maki; Benavente, María; Bray, Sarah J.; Galindo, Máximo Ibo

2012-01-01

The generation of functional structures during development requires tight spatial regulation of signaling pathways. Thus, in Drosophila legs, in which Notch pathway activity is required to specify joints, only cells distal to ligand-producing cells are capable of responding. Here, we show that the asymmetric distribution of planar cell polarity (PCP) proteins correlates with this spatial restriction of Notch activation. Frizzled and Dishevelled are enriched at distal sides of each cell and hence localize at the interface with ligand-expressing cells in the non-responding cells. Elimination of PCP gene function in cells proximal to ligand-expressing cells is sufficient to alleviate the repression, resulting in ectopic Notch activity and ectopic joint formation. Mutations that compromise a direct interaction between Dishevelled and Notch reduce the efficacy of repression. Likewise, increased Rab5 levels or dominant-negative Deltex can suppress the ectopic joints. Together, these results suggest that PCP coordinates the spatial activity of the Notch pathway by regulating endocytic trafficking of the receptor. PMID:22736244

Measuring Sister Chromatid Cohesion Protein Genome Occupancy in Drosophila melanogaster by ChIP-seq.

PubMed

Dorsett, Dale; Misulovin, Ziva

2017-01-01

This chapter presents methods to conduct and analyze genome-wide chromatin immunoprecipitation of the cohesin complex and the Nipped-B cohesin loading factor in Drosophila cells using high-throughput DNA sequencing (ChIP-seq). Procedures for isolation of chromatin, immunoprecipitation, and construction of sequencing libraries for the Ion Torrent Proton high throughput sequencer are detailed, and computational methods to calculate occupancy as input-normalized fold-enrichment are described. The results obtained by ChIP-seq are compared to those obtained by ChIP-chip (genomic ChIP using tiling microarrays), and the effects of sequencing depth on the accuracy are analyzed. ChIP-seq provides similar sensitivity and reproducibility as ChIP-chip, and identifies the same broad regions of occupancy. The locations of enrichment peaks, however, can differ between ChIP-chip and ChIP-seq, and low sequencing depth can splinter broad regions of occupancy into distinct peaks.

Loss of SPARC dysregulates basal lamina assembly to disrupt larval fat body homeostasis in Drosophila melanogaster.

PubMed

Shahab, Jaffer; Baratta, Cristina; Scuric, Bianca; Godt, Dorothea; Venken, Koen J T; Ringuette, Maurice J

2015-04-01

SPARC is a collagen-binding glycoprotein whose functions during early development are unknown. We previously reported that SPARC is expressed in Drosophila by hemocytes and the fat body (FB) and enriched in basal laminae (BL) surrounding tissues, including adipocytes. We sought to explore if SPARC is required for proper BL assembly in the FB. SPARC deficiency leads to larval lethality, associated with remodeling of the FB. In the absence of SPARC, FB polygonal adipocytes assume a spherical morphology. Loss-of-function clonal analyses revealed a cell-autonomous accumulation of BL components around mutant cells that include collagen IV (Col lV), Laminin, and Perlecan. Ultrastructural analyses indicate SPARC-deficient adipocytes are surrounded by an aberrant accumulation of a fibrous extracellular matrix. Our data indicate a critical requirement for SPARC for the proper BL assembly in Drosophila FB. Since Col IV within the BL is a prime determinant of cell shape, the rounded appearance of SPARC-deficient adipocytes is due to aberrant assembly of Col IV. © 2014 Wiley Periodicals, Inc.

Modulation of Differentiation Processes in Murine Embryonic Stem Cells Exposed to Parabolic Flight-Induced Acute Hypergravity and Microgravity.

PubMed

Acharya, Aviseka; Brungs, Sonja; Henry, Margit; Rotshteyn, Tamara; Singh Yaduvanshi, Nirmala; Wegener, Lucia; Jentzsch, Simon; Hescheler, Jürgen; Hemmersbach, Ruth; Boeuf, Helene; Sachinidis, Agapios

2018-06-15

Embryonic developmental studies under microgravity conditions in space are very limited. To study the effects of short-term altered gravity on embryonic development processes, we exposed mouse embryonic stem cells (mESCs) to phases of hypergravity and microgravity and studied the differentiation potential of the cells using wide-genome microarray analysis. During the 64th European Space Agency's parabolic flight campaign, mESCs were exposed to 31 parabolas. Each parabola comprised phases lasting 22 s of hypergravity, microgravity, and a repeat of hypergravity. On different parabolas, RNA was isolated for microarray analysis. After exposure to 31 parabolas, mESCs (P31 mESCs) were further differentiated under normal gravity (1 g) conditions for 12 days, producing P31 12-day embryoid bodies (EBs). After analysis of the microarrays, the differentially expressed genes were analyzed using different bioinformatic tools to identify developmental and nondevelopmental biological processes affected by conditions on the parabolic flight experiment. Our results demonstrated that several genes belonging to GOs associated with cell cycle and proliferation were downregulated in undifferentiated mESCs exposed to gravity changes. However, several genes belonging to developmental processes, such as vasculature development, kidney development, skin development, and to the TGF-β signaling pathway, were upregulated. Interestingly, similar enriched and suppressed GOs were obtained in P31 12-day EBs compared with ground control 12-day EBs. Our results show that undifferentiated mESCs exposed to alternate hypergravity and microgravity phases expressed several genes associated with developmental/differentiation and cell cycle processes, suggesting a transition from the undifferentiated pluripotent to a more differentiated stage of mESCs.

Whole-Genome Resequencing of Experimental Populations Reveals Polygenic Basis of Egg-Size Variation in Drosophila melanogaster

PubMed Central

Jha, Aashish R.; Miles, Cecelia M.; Lippert, Nodia R.; Brown, Christopher D.; White, Kevin P.; Kreitman, Martin

2015-01-01

Complete genome resequencing of populations holds great promise in deconstructing complex polygenic traits to elucidate molecular and developmental mechanisms of adaptation. Egg size is a classic adaptive trait in insects, birds, and other taxa, but its highly polygenic architecture has prevented high-resolution genetic analysis. We used replicated experimental evolution in Drosophila melanogaster and whole-genome sequencing to identify consistent signatures of polygenic egg-size adaptation. A generalized linear-mixed model revealed reproducible allele frequency differences between replicated experimental populations selected for large and small egg volumes at approximately 4,000 single nucleotide polymorphisms (SNPs). Several hundred distinct genomic regions contain clusters of these SNPs and have lower heterozygosity than the genomic background, consistent with selection acting on polymorphisms in these regions. These SNPs are also enriched among genes expressed in Drosophila ovaries and many of these genes have well-defined functions in Drosophila oogenesis. Additional genes regulating egg development, growth, and cell size show evidence of directional selection as genes regulating these biological processes are enriched for highly differentiated SNPs. Genetic crosses performed with a subset of candidate genes demonstrated that these genes influence egg size, at least in the large genetic background. These findings confirm the highly polygenic architecture of this adaptive trait, and suggest the involvement of many novel candidate genes in regulating egg size. PMID:26044351

Somatic insulin signaling regulates a germline starvation response in Drosophila egg chambers

PubMed Central

Burn, K. Mahala; Shimada, Yuko; Ayers, Kathleen; Lu, Feiyue; Hudson, Andrew M.; Cooley, Lynn

2014-01-01

Egg chambers from starved Drosophila females contain large aggregates of processing (P) bodies and cortically enriched microtubules. As this response to starvation is rapidly reversed upon re-feeding females or culturing egg chambers with exogenous bovine insulin, we examined the role of endogenous insulin signaling in mediating the starvation response. We found that systemic Drosophila insulin-like peptides (dILPs) activate the insulin pathway in follicle cells, which then regulate both microtubule and P body organization in the underlying germline cells. This organization is modulated by the motor proteins Dynein and Kinesin. Dynein activity is required for microtubule and P body organization during starvation, while Kinesin activity is required during nutrient-rich conditions. Blocking the ability of egg chambers to form P body aggregates in response to starvation correlated with reduced progeny survival. These data suggest a potential mechanism to maximize fecundity even during periods of poor nutrient availability, by mounting a protective response in immature egg chambers. PMID:25481758

Titanium-Enriched Hydroxyapatite–Gelatin Scaffolds with Osteogenically Differentiated Progenitor Cell Aggregates for Calvaria Bone Regeneration

PubMed Central

Padilla, Ricardo; Urkasemsin, Ganokon; Yoon, Kun; Goeckner, Kelly; Hu, Wei-Shou

2013-01-01

Adequate bony support is the key to re-establish both function and esthetics in the craniofacial region. Autologous bone grafting has been the gold standard for regeneration of problematic large bone defects. However, poor graft availability and donor-site complications have led to alternative bone tissue-engineering approaches combining osteoinductive biomaterials and three-dimensional cell aggregates in scaffolds or constructs. The goal of the present study was to generate novel cell aggregate-loaded macroporous scaffolds combining the osteoinductive properties of titanium dioxide (TiO2) with hydroxyapatite–gelatin nanocomposites (HAP-GEL) for regeneration of craniofacial defects. Here we investigated the in vivo applicability of macroporous (TiO2)-enriched HAP-GEL scaffolds with undifferentiated and osteogenically differentiated multipotent adult progenitor cell (MAPC and OD-MAPC, respectively) aggregates for calvaria bone regeneration. The silane-coated HAP-GEL with and without TiO2 additives were polymerized and molded to produce macroporous scaffolds. Aggregates of the rat MAPC were precultured, loaded into each scaffold, and implanted to rat calvaria critical-size defects to study bone regeneration. Bone autografts were used as positive controls and a poly(lactic-co-glycolic acid) (PLGA) scaffold for comparison purposes. Preimplanted scaffolds and calvaria bone from pig were tested for ultimate compressive strength with an Instron 4411® and for porosity with microcomputerized tomography (μCT). Osteointegration and newly formed bone (NFB) were assessed by μCT and nondecalcified histology, and quantified by calcium fluorescence labeling. Results showed that the macroporous TiO2-HAP-GEL scaffold had a comparable strength relative to the natural calvaria bone (13.8±4.5 MPa and 24.5±8.3 MPa, respectively). Porosity was 1.52±0.8 mm and 0.64±0.4 mm for TiO2-HAP-GEL and calvaria bone, respectively. At 8 and 12 weeks postimplantation into rat calvaria defects, greater osteointegration and NFB were significantly present in the TiO2-enriched HAP-GEL constructs with OD-MAPCs, compared to the undifferentiated MAPC-loaded constructs, cell-free HAP-GEL with and without titanium, and PLGA scaffolds. The tissue-engineered TiO2-enriched HAP-GEL constructs with OD-MAPC aggregates present a potential useful therapeutic approach for calvaria bone regeneration. PMID:23495972

Multifunctional glial support by Semper cells in the Drosophila retina

PubMed Central

Charlton-Perkins, Mark A.

2017-01-01

Glial cells play structural and functional roles central to the formation, activity and integrity of neurons throughout the nervous system. In the retina of vertebrates, the high energetic demand of photoreceptors is sustained in part by Müller glia, an intrinsic, atypical radial glia with features common to many glial subtypes. Accessory and support glial cells also exist in invertebrates, but which cells play this function in the insect retina is largely undefined. Using cell-restricted transcriptome analysis, here we show that the ommatidial cone cells (aka Semper cells) in the Drosophila compound eye are enriched for glial regulators and effectors, including signature characteristics of the vertebrate visual system. In addition, cone cell-targeted gene knockdowns demonstrate that such glia-associated factors are required to support the structural and functional integrity of neighboring photoreceptors. Specifically, we show that distinct support functions (neuronal activity, structural integrity and sustained neurotransmission) can be genetically separated in cone cells by down-regulating transcription factors associated with vertebrate gliogenesis (pros/Prox1, Pax2/5/8, and Oli/Olig1,2, respectively). Further, we find that specific factors critical for glial function in other species are also critical in cone cells to support Drosophila photoreceptor activity. These include ion-transport proteins (Na/K+-ATPase, Eaat1, and Kir4.1-related channels) and metabolic homeostatic factors (dLDH and Glut1). These data define genetically distinct glial signatures in cone/Semper cells that regulate their structural, functional and homeostatic interactions with photoreceptor neurons in the compound eye of Drosophila. In addition to providing a new high-throughput model to study neuron-glia interactions, the fly eye will further help elucidate glial conserved "support networks" between invertebrates and vertebrates. PMID:28562601

Definition of a RACK1 Interaction Network in Drosophila melanogaster Using SWATH-MS.

PubMed

Kuhn, Lauriane; Majzoub, Karim; Einhorn, Evelyne; Chicher, Johana; Pompon, Julien; Imler, Jean-Luc; Hammann, Philippe; Meignin, Carine

2017-07-05

Receptor for Activated protein C kinase 1 (RACK1) is a scaffold protein that has been found in association with several signaling complexes, and with the 40S subunit of the ribosome. Using the model organism Drosophila melanogaster , we recently showed that RACK1 is required at the ribosome for internal ribosome entry site (IRES)-mediated translation of viruses. Here, we report a proteomic characterization of the interactome of RACK1 in Drosophila S2 cells. We carried out Label-Free quantitation using both Data-Dependent and Data-Independent Acquisition (DDA and DIA, respectively) and observed a significant advantage for the Sequential Window Acquisition of all THeoretical fragment-ion spectra (SWATH) method, both in terms of identification of interactants and quantification of low abundance proteins. These data represent the first SWATH spectral library available for Drosophila and will be a useful resource for the community. A total of 52 interacting proteins were identified, including several molecules involved in translation such as structural components of the ribosome, factors regulating translation initiation or elongation, and RNA binding proteins. Among these 52 proteins, 15 were identified as partners by the SWATH strategy only. Interestingly, these 15 proteins are significantly enriched for the functions translation and nucleic acid binding. This enrichment reflects the engagement of RACK1 at the ribosome and highlights the added value of SWATH analysis. A functional screen did not reveal any protein sharing the interesting properties of RACK1, which is required for IRES-dependent translation and not essential for cell viability. Intriguingly however, 10 of the RACK1 partners identified restrict replication of Cricket paralysis virus (CrPV), an IRES-containing virus. Copyright © 2017 Kuhn et al.

Sorafenib selectively depletes human glioblastoma tumor-initiating cells from primary cultures

PubMed Central

Carra, Elisa; Barbieri, Federica; Marubbi, Daniela; Pattarozzi, Alessandra; Favoni, Roberto E.; Florio, Tullio; Daga, Antonio

2013-01-01

Glioblastomas are grade IV brain tumors characterized by high aggressiveness and invasiveness, giving patients a poor prognosis. We investigated the effects of the multi-kinase inhibitor sorafenib on six cultures isolated from human glioblastomas and maintained in tumor initiating cells-enriching conditions. These cell subpopulations are thought to be responsible for tumor recurrence and radio- and chemo-resistance, representing the perfect target for glioblastoma therapy. Sorafenib reduces proliferation of glioblastoma cultures, and this effect depends, at least in part, on the inhibition of PI3K/Akt and MAPK pathways, both involved in gliomagenesis. Sorafenib significantly induces apoptosis/cell death via downregulation of the survival factor Mcl-1. We provide evidence that sorafenib has a selective action on glioblastoma stem cells, causing enrichment of cultures in differentiated cells, downregulation of the expression of stemness markers required to maintain malignancy (nestin, Olig2 and Sox2) and reducing cell clonogenic ability in vitro and tumorigenic potential in vivo. The selectivity of sorafenib effects on glioblastoma stem cells is confirmed by the lower sensitivity of glioblastoma cultures after differentiation as compared with the undifferentiated counterpart. Since current GBM therapy enriches the tumor in cancer stem cells, the evidence of a selective action of sorafenib on these cells is therapeutically relevant, even if, so far, results from first phase II clinical trials did not demonstrate its efficacy. PMID:23324350

Sorafenib selectively depletes human glioblastoma tumor-initiating cells from primary cultures.

PubMed

Carra, Elisa; Barbieri, Federica; Marubbi, Daniela; Pattarozzi, Alessandra; Favoni, Roberto E; Florio, Tullio; Daga, Antonio

2013-02-01

Glioblastomas are grade IV brain tumors characterized by high aggressiveness and invasiveness, giving patients a poor prognosis. We investigated the effects of the multi-kinase inhibitor sorafenib on six cultures isolated from human glioblastomas and maintained in tumor initiating cells-enriching conditions. These cell subpopulations are thought to be responsible for tumor recurrence and radio- and chemo-resistance, representing the perfect target for glioblastoma therapy. Sorafenib reduces proliferation of glioblastoma cultures, and this effect depends, at least in part, on the inhibition of PI3K/Akt and MAPK pathways, both involved in gliomagenesis. Sorafenib significantly induces apoptosis/cell death via downregulation of the survival factor Mcl-1. We provide evidence that sorafenib has a selective action on glioblastoma stem cells, causing enrichment of cultures in differentiated cells, downregulation of the expression of stemness markers required to maintain malignancy (nestin, Olig2 and Sox2) and reducing cell clonogenic ability in vitro and tumorigenic potential in vivo. The selectivity of sorafenib effects on glioblastoma stem cells is confirmed by the lower sensitivity of glioblastoma cultures after differentiation as compared with the undifferentiated counterpart. Since current GBM therapy enriches the tumor in cancer stem cells, the evidence of a selective action of sorafenib on these cells is therapeutically relevant, even if, so far, results from first phase II clinical trials did not demonstrate its efficacy.

ETV4 is a useful marker for the diagnosis of CIC-rearranged undifferentiated round-cell sarcomas: a study of 127 cases including mimicking lesions.

PubMed

Le Guellec, Sophie; Velasco, Valérie; Pérot, Gaëlle; Watson, Sarah; Tirode, Franck; Coindre, Jean-Michel

2016-12-01

Subsets of primitive round-cell sarcomas remain difficult to diagnose and classify. Among these is a rare round-cell sarcoma that harbors a CIC gene rearrangement known as CIC-rearranged undifferentiated round-cell sarcoma, which is most commonly fused to the DUX4 gene. Owing to its aggressive clinical behavior and potential therapeutic implications, accurate identification of this novel soft tissue sarcoma is necessary. Definitive diagnosis requires molecular confirmation, but only a few centers are as yet able to perform this test. Several studies have shown that PEA3 subfamily genes, notably ETV4 (belonging to the family of ETS transcription factors), are upregulated in CIC-rearranged undifferentiated round-cell sarcomas. We performed a detailed immunohistochemical analysis to investigate ETV4 expression in CIC-rearranged undifferentiated round-cell sarcomas and their potential mimics (especially Ewing sarcomas). The study cohort included 17 cases of CIC-rearranged undifferentiated round-cell sarcomas, and 110 tumors that morphologically mimic CIC-rearranged undifferentiated round-cell sarcomas: 43 Ewing sarcomas, 25 alveolar rhabdomyosarcomas, 20 poorly differentiated round-cell synovial sarcomas, 10 desmoplastic round-cell tumors, 5 BCOR-CCNB3 sarcomas, 5 lymphoblastic lymphomas, and 2 rhabdoid tumors. All CIC-rearranged undifferentiated round-cell sarcomas (on core needle biopsies and open biopsies) were ETV4-positive with a strong diffuse nuclear pattern. Among the other 110 tumors, only six cases (four Ewing sarcomas, one alveolar rhabdomyosarcoma, and one desmoplastic round-cell tumor) showed focal (<5% of tumor cells) and very weak nuclear expression of ETV4; all other tumors were completely negative for ETV4. We conclude that systematic immunohistochemical analysis of ETV4 makes it possible to diagnose undifferentiated round-cell sarcomas (with no molecular markers for sarcoma-associated translocation) such as CIC-rearranged undifferentiated round-cell sarcoma.

Temporal Transcriptional Profiling of Somatic and Germ Cells Reveals Biased Lineage Priming of Sexual Fate in the Fetal Mouse Gonad

PubMed Central

Jameson, Samantha A.; Natarajan, Anirudh; Cool, Jonah; DeFalco, Tony; Maatouk, Danielle M.; Mork, Lindsey; Munger, Steven C.; Capel, Blanche

2012-01-01

The divergence of distinct cell populations from multipotent progenitors is poorly understood, particularly in vivo. The gonad is an ideal place to study this process, because it originates as a bipotential primordium where multiple distinct lineages acquire sex-specific fates as the organ differentiates as a testis or an ovary. To gain a more detailed understanding of the process of gonadal differentiation at the level of the individual cell populations, we conducted microarrays on sorted cells from XX and XY mouse gonads at three time points spanning the period when the gonadal cells transition from sexually undifferentiated progenitors to their respective sex-specific fates. We analyzed supporting cells, interstitial/stromal cells, germ cells, and endothelial cells. This work identified genes specifically depleted and enriched in each lineage as it underwent sex-specific differentiation. We determined that the sexually undifferentiated germ cell and supporting cell progenitors showed lineage priming. We found that germ cell progenitors were primed with a bias toward the male fate. In contrast, supporting cells were primed with a female bias, indicative of the robust repression program involved in the commitment to XY supporting cell fate. This study provides a molecular explanation reconciling the female default and balanced models of sex determination and represents a rich resource for the field. More importantly, it yields new insights into the mechanisms by which different cell types in a single organ adopt their respective fates. PMID:22438826

Dynamic self-organisation of haematopoiesis and (a)symmetric cell division.

PubMed

Måløy, Marthe; Måløy, Frode; Jakobsen, Per; Olav Brandsdal, Bjørn

2017-02-07

A model of haematopoiesis that links self-organisation with symmetric and asymmetric cell division is presented in this paper. It is assumed that all cell divisions are completely random events, and that the daughter cells resulting from symmetric and asymmetric stem cell divisions are, in general, phenotypically identical, and still, the haematopoietic system has the flexibility to self-renew, produce mature cells by differentiation, and regenerate undifferentiated and differentiated cells when necessary, due to self-organisation. As far as we know, no previous model implements symmetric and asymmetric division as the result of self-organisation. The model presented in this paper is inspired by experiments on the Drosophila germline stem cell, which imply that under normal conditions, the stem cells typically divide asymmetrically, whereas during regeneration, the rate of symmetric division increases. Moreover, the model can reproduce several of the results from experiments on female Safari cats. In particular, the model can explain why significant fluctuation in the phenotypes of haematopoietic cells was observed in some cats, when the haematopoietic system had reached normal population level after regeneration. To our knowledge, no previous model of haematopoiesis in Safari cats has captured this phenomenon. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

SUMO-Enriched Proteome for Drosophila Innate Immune Response

PubMed Central

Handu, Mithila; Kaduskar, Bhagyashree; Ravindranathan, Ramya; Soory, Amarendranath; Giri, Ritika; Elango, Vijay Barathi; Gowda, Harsha; Ratnaparkhi, Girish S.

2015-01-01

Small ubiquitin-like modifier (SUMO) modification modulates the expression of defense genes in Drosophila, activated by the Toll/nuclear factor-κB and immune-deficient/nuclear factor-κB signaling networks. We have, however, limited understanding of the SUMO-modulated regulation of the immune response and lack information on SUMO targets in the immune system. In this study, we measured the changes to the SUMO proteome in S2 cells in response to a lipopolysaccharide challenge and identified 1619 unique proteins in SUMO-enriched lysates. A confident set of 710 proteins represents the immune-induced SUMO proteome and analysis suggests that specific protein domains, cellular pathways, and protein complexes respond to immune stress. A small subset of the confident set was validated by in-bacto SUMOylation and shown to be bona-fide SUMO targets. These include components of immune signaling pathways such as Caspar, Jra, Kay, cdc42, p38b, 14-3-3ε, as well as cellular proteins with diverse functions, many being components of protein complexes, such as prosß4, Rps10b, SmD3, Tango7, and Aats-arg. Caspar, a human FAF1 ortholog that negatively regulates immune-deficient signaling, is SUMOylated at K551 and responds to treatment with lipopolysaccharide in cultured cells. Our study is one of the first to describe SUMO proteome for the Drosophila immune response. Our data and analysis provide a global framework for the understanding of SUMO modification in the host response to pathogens. PMID:26290570

SUMO-Enriched Proteome for Drosophila Innate Immune Response.

PubMed

Handu, Mithila; Kaduskar, Bhagyashree; Ravindranathan, Ramya; Soory, Amarendranath; Giri, Ritika; Elango, Vijay Barathi; Gowda, Harsha; Ratnaparkhi, Girish S

2015-08-18

Small ubiquitin-like modifier (SUMO) modification modulates the expression of defense genes in Drosophila, activated by the Toll/nuclear factor-κB and immune-deficient/nuclear factor-κB signaling networks. We have, however, limited understanding of the SUMO-modulated regulation of the immune response and lack information on SUMO targets in the immune system. In this study, we measured the changes to the SUMO proteome in S2 cells in response to a lipopolysaccharide challenge and identified 1619 unique proteins in SUMO-enriched lysates. A confident set of 710 proteins represents the immune-induced SUMO proteome and analysis suggests that specific protein domains, cellular pathways, and protein complexes respond to immune stress. A small subset of the confident set was validated by in-bacto SUMOylation and shown to be bona-fide SUMO targets. These include components of immune signaling pathways such as Caspar, Jra, Kay, cdc42, p38b, 14-3-3ε, as well as cellular proteins with diverse functions, many being components of protein complexes, such as prosß4, Rps10b, SmD3, Tango7, and Aats-arg. Caspar, a human FAF1 ortholog that negatively regulates immune-deficient signaling, is SUMOylated at K551 and responds to treatment with lipopolysaccharide in cultured cells. Our study is one of the first to describe SUMO proteome for the Drosophila immune response. Our data and analysis provide a global framework for the understanding of SUMO modification in the host response to pathogens. Copyright © 2015 Handu et al.

Loss of EGFR-ASAP1 signaling in metastatic and unresectable hepatoblastoma.

PubMed

Ranganathan, Sarangarajan; Ningappa, Mylarappa; Ashokkumar, Chethan; Higgs, Brandon W; Min, Jun; Sun, Qing; Schmitt, Lori; Subramaniam, Shankar; Hakonarson, Hakon; Sindhi, Rakesh

2016-12-02

Hepatoblastoma (HBL), the most common childhood liver cancer is cured with surgical resection after chemotherapy or with liver transplantation if local invasion and multifocality preclude resection. However, variable survival rates of 60-80% and debilitating chemotherapy sequelae argue for more informed treatment selection, which is not possible by grading the Wnt-β-catenin over activity present in most HBL tumors. A hypothesis-generating whole transcriptome analysis shows that HBL tumors removed at transplantation are enriched most for cancer signaling pathways which depend predominantly on epidermal growth factor (EGF) signaling, and to a lesser extent, on aberrant Wnt-β-catenin signaling. We therefore evaluated whether EGFR, ASAP1, ERBB2 and ERBB4, which signal downstream after ligation of EGF, and which show aberrant expression in several other invasive cancers, would also predict HBL tumor invasiveness. Immunohistochemistry of HBL tumors (n = 60), which are histologically heterogeneous, shows that compared with well-differentiated fetal cells, less differentiated embryonal and undifferentiated small cells (SCU) progressively lose EGFR and ASAP1 expression. This trend is exaggerated in unresectable, locally invasive or metastatic tumors, in which embryonal tumor cells are EGFR-negative, while SCU cells are EGFR-negative and ASAP1-negative. Loss of EGFR-ASAP1 signaling characterizes undifferentiated and invasive HBL. EGFR-expressing HBL tumors present novel therapeutic targeting opportunities.

Cryopreservation of putative pre-pubertal bovine spermatogonial stem cells by slow freezing.

PubMed

Kim, Ki-Jung; Lee, Yong-An; Kim, Bang-Jin; Kim, Yong-Hee; Kim, Byung-Gak; Kang, Hyun-Gu; Jung, Sang-Eun; Choi, Sun-Ho; Schmidt, Jonathan A; Ryu, Buom-Yong

2015-04-01

Development of techniques for the preservation of mammalian spermatogonial stem cells (SSCs) is a critical step in commercial application of SSC based technologies, including species preservation, amplification of agriculturally valuable germ lines, and human fertility preservations. The objective of this study was to develop an efficient cryopreservation protocol for preservation of bovine SSCs using a slow freezing technique. To maximize the efficiency of SSC cryopreservation, the effects of various methods (tissue vs. cell freezing) and cryoprotective agents (trehalose, sucrose, and polyethylene glycol [PEG]) were tested. Following thawing, cells were enriched for undifferentiated spermatogonia by differential plating and evaluated for recovery rate, proliferation capacity, and apoptosis. Additionally, putative stem cell activity was assessed using SSC xenotransplantation. The recovery rate, and proliferation capacity of undifferentiated spermatogonia were significantly greater for germ cells frozen using tissue freezing methods compared to cell freezing methods. Cryopreservation in the presence of 200 mM trehalose resulted in significantly greater recovery rate, proliferation capacity, and apoptosis of germ cells compared to control. Furthermore, cryopreservation using the tissue freezing method in the presence of 200 mM trehalose resulted in the production of colonies of donor-derived germ cells after xenotransplantation into recipient mouse testes, indicating putative stem cell function. Collectively, these data indicate that cryopreservation using tissue freezing methods in the presence of 200 mM trehalose is an efficient cryopreservation protocol for bovine SSCs. Copyright © 2015 Elsevier Inc. All rights reserved.

Whole-Genome Resequencing of Experimental Populations Reveals Polygenic Basis of Egg-Size Variation in Drosophila melanogaster.

PubMed

Jha, Aashish R; Miles, Cecelia M; Lippert, Nodia R; Brown, Christopher D; White, Kevin P; Kreitman, Martin

2015-10-01

Complete genome resequencing of populations holds great promise in deconstructing complex polygenic traits to elucidate molecular and developmental mechanisms of adaptation. Egg size is a classic adaptive trait in insects, birds, and other taxa, but its highly polygenic architecture has prevented high-resolution genetic analysis. We used replicated experimental evolution in Drosophila melanogaster and whole-genome sequencing to identify consistent signatures of polygenic egg-size adaptation. A generalized linear-mixed model revealed reproducible allele frequency differences between replicated experimental populations selected for large and small egg volumes at approximately 4,000 single nucleotide polymorphisms (SNPs). Several hundred distinct genomic regions contain clusters of these SNPs and have lower heterozygosity than the genomic background, consistent with selection acting on polymorphisms in these regions. These SNPs are also enriched among genes expressed in Drosophila ovaries and many of these genes have well-defined functions in Drosophila oogenesis. Additional genes regulating egg development, growth, and cell size show evidence of directional selection as genes regulating these biological processes are enriched for highly differentiated SNPs. Genetic crosses performed with a subset of candidate genes demonstrated that these genes influence egg size, at least in the large genetic background. These findings confirm the highly polygenic architecture of this adaptive trait, and suggest the involvement of many novel candidate genes in regulating egg size. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

A large-scale, in vivo transcription factor screen defines bivalent chromatin as a key property of regulatory factors mediating Drosophila wing development

PubMed Central

Schertel, Claus; Albarca, Monica; Rockel-Bauer, Claudia; Kelley, Nicholas W.; Bischof, Johannes; Hens, Korneel

2015-01-01

Transcription factors (TFs) are key regulators of cell fate. The estimated 755 genes that encode DNA binding domain-containing proteins comprise ∼5% of all Drosophila genes. However, the majority has remained uncharacterized so far due to the lack of proper genetic tools. We generated 594 site-directed transgenic Drosophila lines that contain integrations of individual UAS-TF constructs to facilitate spatiotemporally controlled misexpression in vivo. All transgenes were expressed in the developing wing, and two-thirds induced specific phenotypic defects. In vivo knockdown of the same genes yielded a phenotype for 50%, with both methods indicating a great potential for misexpression to characterize novel functions in wing growth, patterning, and development. Thus, our UAS-TF library provides an important addition to the genetic toolbox of Drosophila research, enabling the identification of several novel wing development-related TFs. In parallel, we established the chromatin landscape of wing imaginal discs by ChIP-seq analyses of five chromatin marks and RNA Pol II. Subsequent clustering revealed six distinct chromatin states, with two clusters showing enrichment for both active and repressive marks. TFs that carry such “bivalent” chromatin are highly enriched for causing misexpression phenotypes in the wing, and analysis of existing expression data shows that these TFs tend to be differentially expressed across the wing disc. Thus, bivalently marked chromatin can be used as a marker for spatially regulated TFs that are functionally relevant in a developing tissue. PMID:25568052

Establishment and characterization of a human uterine endometrial undifferentiated carcinoma cell line, TMG-L.

PubMed

Hasegawa, Kiyoshi; Suzuki, Machiko; Ishikawa, Kunimi; Yasue, Akira; Kato, Rina; Nakamura, Azumi; Kuroki, Jun; Udagawa, Yasuhiro

2003-03-01

A new cell line of human uterine endometrial undifferentiated carcinoma, designated as TMG-L, was established from the metastatic lymph node of 56-year-old patient TMG-L cells have been cultured with Ham's F-12 medium supplemented with 10% FCS and grew as a loosely adherent monolayer with polygonal or spindle-shaped cells exhibiting poor cell-cell contact and piled up against each other, showing a tendency to grow as floating cells. The doubling time of this cell line was about 48 hours, and chromosomal analysis revealed aneuploidy at passage 25. The cells formed tumors in SCID mouse, the histology of which was similar to that of undifferentiated carcinoma component of primary tumor. TMG-L cells showed the loss of expression and membranous localization of either E-cadherin or alpha-catenin, implied corresponding loss of their adhesive function. And this dysfunction implicated the biological aggressive behavior of uterine endometrial undifferentiated carcinoma. This cell line appears to provide a useful system for studying uterine undifferentiated carcinoma in vivo and in vitro.

Remodeling of the abdominal epithelial monolayer during the larva-pupa-adult transformation of Manduca.

PubMed

Nardi, James B; Bee, Charles Mark; Wallace, Catherine Lee

2018-06-01

During metamorphosis of insect epithelial monolayers, cells die, divide, and rearrange. In Drosophila undifferentiated diploid cells destined to form the adult cuticle of each abdominal segment segregate early in development from the surrounding polyploid larval epithelial cells of that segment as eight groups of diploid histoblast cells. The larval polyploid cells are programmed to die and be replaced by divisions and rearrangements of histoblast cells. By contrast, abdominal epithelial cells of Manduca larvae form a monolayer of cells representing different ploidy levels with no definitive segregation of diploid cells destined to form adult structures. These epithelial cells of mixed ploidy levels produce a thick smooth larval cuticle with sparsely distributed sensory bristles. Adult descendants of this larval monolayer produce a thinner cuticle with densely packed scale cells. The transition between these differentiated states of Manduca involves divisions of cells, changes in ploidy levels, and sorting of certain polyploid cells into circular rosette patches to minimize contacts of these polyploid cells with surrounding cells of equal or smaller size. Cells within the rosettes and some surrounding cells are destined to die and be replaced by remaining epithelial cells of uniform size and ploidy at pupa-adult apolysis. Copyright © 2018 Elsevier Inc. All rights reserved.

Population Distribution Analyses Reveal a Hierarchy of Molecular Players Underlying Parallel Endocytic Pathways

PubMed Central

Gupta, Gagan D.; Howes, Mark T.; Chandran, Ruma; Das, Anupam; Menon, Sindhu; Parton, Robert G.; Sowdhamini, R.; Thattai, Mukund; Mayor, Satyajit

2014-01-01

Single-cell-resolved measurements reveal heterogeneous distributions of clathrin-dependent (CD) and -independent (CLIC/GEEC: CG) endocytic activity in Drosophila cell populations. dsRNA-mediated knockdown of core versus peripheral endocytic machinery induces strong changes in the mean, or subtle changes in the shapes of these distributions, respectively. By quantifying these subtle shape changes for 27 single-cell features which report on endocytic activity and cell morphology, we organize 1072 Drosophila genes into a tree-like hierarchy. We find that tree nodes contain gene sets enriched in functional classes and protein complexes, providing a portrait of core and peripheral control of CD and CG endocytosis. For 470 genes we obtain additional features from separate assays and classify them into early- or late-acting genes of the endocytic pathways. Detailed analyses of specific genes at intermediate levels of the tree suggest that Vacuolar ATPase and lysosomal genes involved in vacuolar biogenesis play an evolutionarily conserved role in CG endocytosis. PMID:24971745

Mechanism and characteristics of stimuli-dependent ROS generation in undifferentiated HL-60 cells.

PubMed

Muranaka, Shikibu; Fujita, Hirofumi; Fujiwara, Takuzo; Ogino, Tetsuya; Sato, Eisuke F; Akiyama, Jitsuo; Imada, Isuke; Inoue, Masayasu; Utsumi, Kozo

2005-01-01

It has been widely believed that undifferentiated human promyelocytic leukemia cells (HL-60) have no ability to generate reactive oxygen species (ROS) responding to stimuli. We report here that undifferentiated HL-60 cells possess NADPH oxidase and that generation of superoxide can be measured using a highly sensitive chemiluminescence dye, L-012. Five subunits of NADPH oxidase, namely, gp91(phox), p22(phox), p67(phox), p47(phox), and Rac 2, were detected in undifferentiated HL-60 cells by immunoblotting analysis. The contents of these NADPH oxidase components in the cells were increased with the differentiation induced by phorbol myristate acetate (PMA), except for p22(phox). Messenger RNAs of these subunits were also detected by the RT-PCR method, and their expressions increased except that of p22(phox) with the differentiation induced by PMA. Kinetic analysis using L-012 revealed that HL-60 cells generated substantial amounts of ROS by various stimulants, including formylmethionyl-leucyl-phenylalanine, PMA, myristic acid, and a Ca2+ ionophore, A23187. Both diphenyleneiodonium (an inhibitor of FAD-dependent oxidase) and apocynin (a specific inhibitor of NADPH oxidase) suppressed this stimuli-dependent ROS generation. Genistein, staurosporine, uric acid, and sodium azide inhibited the ROS generation in undifferentiated HL-60 cells in a similar way to that in undifferentiated neutrophils. These results suggested that the mechanism of ROS generation in undifferentiated HL-60 cells is the same as that in primed neutrophils.

A monoclonal antibody recognizes undifferentiation-specific carbohydrate moieties expressed on cell surface of the human dental pulp cells.

PubMed

Kang, Kyung-Jung; Ko, Seon-Yle; Ryu, Chun-Jeih; Jang, Young-Joo

2017-05-01

Human dental pulp cells are obtained from dental pulp tissue, and have the ability to form dentin and a pulp-like complex. Although adult stem cells have been identified from the primary culture by using specific cell surface markers, the identity of surface markers for the purification of stem cells within the dental pulp population are still unclear. Previously, we had constructed monoclonal antibodies against the undifferentiated cell-specific surface markers of human dental pulp cells (hDPCs) by performing decoy immunization. Among them, a monoclonal antibody against the cell surface antigen of the undifferentiated hDPCs (named UPSA-1) was purified and its heavy and light chain consensus regions were analyzed. The cell surface binding affinity of UPSA-1 mAb on the undifferentiated hDPCs was stronger than that on the differentiated cells. When tunicamycin was applied to hDPSCs during culture, the cell surface binding affinity of the antibody was dramatically decreased, and dentinogenic differentiation was reduced. The purified UPSA-1 antigen band resulting from immunoprecipitation disappeared or shifted down on the SDS-PAGE by deglycosylation. These data suggested that glycosylation on the cell surface might be a marker of an undifferentiated state, and that UPSA-1 mAb might be useful for identifying the carbohydrate moiety on the cell surface of undifferentiated pulp cells. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Identification of distinct topographical surface microstructures favoring either undifferentiated expansion or differentiation of murine embryonic stem cells.

PubMed

Markert, Lotte D'Andrea; Lovmand, Jette; Foss, Morten; Lauridsen, Rune Hoff; Lovmand, Michael; Füchtbauer, Ernst-Martin; Füchtbauer, Annette; Wertz, Karin; Besenbacher, Flemming; Pedersen, Finn Skou; Duch, Mogens

2009-11-01

The potential of embryonic stem (ES) cells for both self-renewal and differentiation into cells of all three germ layers has generated immense interest in utilizing these cells for tissue engineering or cell-based therapies. However, the ability to culture undifferentiated ES cells without the use of feeder cells as well as means to obtain homogeneous, differentiated cell populations devoid of residual pluripotent ES cells still remain major challenges. Here we have applied murine ES cells to topographically microstructured surface libraries, BioSurface Structure Arrays (BSSA), and investigated whether these could be used to (i) identify topographically microstructured growth supports alleviating the need for feeder cells for expansion of undifferentiated ES cells and (ii) identify specific types of microstructures enforcing differentiation of ES cells. The BSSA surfaces arrays consisted of 504 different topographical microstructures each located in a tester field of 3 x 3 mm. The murine ES cell lines CJ7 and KH2 were seeded upon the BSSA libraries and specific topographical structures facilitating either undifferentiated ES cell growth or enhancing spreading indicative of differentiation of the ES cells were identified. Secondly serial passage of undifferentiated CJ7 ES cells on selected microstructures, identified in the screening of these BSSA libraries, showed that these cells had retained germ-line potential. These results indicate that one specific type of topographical surface microstructures, identified by the BSSA technology, can substitute for feeder cells and that another subset may be used to eliminate undifferentiated ES cells from a population of differentiated ES cells.

Superficial EWSR1-negative undifferentiated small round cell sarcoma with CIC/DUX4 gene fusion: a new variant of Ewing-like tumors with locoregional lymph node metastasis.

PubMed

Machado, Isidro; Cruz, Julia; Lavernia, Javier; Rubio, Luis; Campos, Jorge; Barrios, María; Grison, Camille; Chene, Virginie; Pierron, Gaelle; Delattre, Olivier; Llombart-Bosch, Antonio

2013-12-01

The present study describes a new case of EWSR1-negative undifferentiated sarcoma with CIC/DUX4 gene fusion. This case is similar to tumors described as primitive undifferentiated round cell sarcomas that occur mainly in the trunk and display an aggressive behavior. To our knowledge, this is the first report of such a tumor presenting locoregional lymph node metastasis. In view of previous studies that prove the existence of a particular variant of undifferentiated sarcoma with Ewing-like morphology and CIC/DUX-4 gene fusion, a search for this gene fusion in all undifferentiated round cell sarcomas should be considered if a conclusive diagnosis cannot be reached following other conventional studies. Although additional cases with more extensive follow-up studies are needed, we believe that EWSR1-negative undifferentiated small round cell sarcoma with CIC/DUX4 gene fusion should be added to the list of new sarcoma variants with the possibility of lymph node metastasis.

The C. elegans homolog of Drosophila Lethal giant larvae functions redundantly with PAR-2 to maintain polarity in the early embryo.

PubMed

Beatty, Alexander; Morton, Diane; Kemphues, Kenneth

2010-12-01

Polarity is essential for generating cell diversity. The one-cell C. elegans embryo serves as a model for studying the establishment and maintenance of polarity. In the early embryo, a myosin II-dependent contraction of the cortical meshwork asymmetrically distributes the highly conserved PDZ proteins PAR-3 and PAR-6, as well as an atypical protein kinase C (PKC-3), to the anterior. The RING-finger protein PAR-2 becomes enriched on the posterior cortex and prevents these three proteins from returning to the posterior. In addition to the PAR proteins, other proteins are required for polarity in many metazoans. One example is the conserved Drosophila tumor-suppressor protein Lethal giant larvae (Lgl). In Drosophila and mammals, Lgl contributes to the maintenance of cell polarity and plays a role in asymmetric cell division. We have found that the C. elegans homolog of Lgl, LGL-1, has a role in polarity but is not essential. It localizes asymmetrically to the posterior of the early embryo in a PKC-3-dependent manner, and functions redundantly with PAR-2 to maintain polarity. Furthermore, overexpression of LGL-1 is sufficient to rescue loss of PAR-2 function. LGL-1 negatively regulates the accumulation of myosin (NMY-2) on the posterior cortex, representing a possible mechanism by which LGL-1 might contribute to polarity maintenance.

The Drosophila Pericentrin-like-protein (PLP) cooperates with Cnn to maintain the integrity of the outer PCM

PubMed Central

Richens, Jennifer H.; Barros, Teresa P.; Lucas, Eliana P.; Peel, Nina; Pinto, David Miguel Susano; Wainman, Alan; Raff, Jordan W.

2015-01-01

ABSTRACT Centrosomes comprise a pair of centrioles surrounded by a matrix of pericentriolar material (PCM). In vertebrate cells, Pericentrin plays an important part in mitotic PCM assembly, but the Drosophila Pericentrin-like protein (PLP) appears to have a more minor role in mitotic fly cells. Here we investigate the function of PLP during the rapid mitotic cycles of the early Drosophila embryo. Unexpectedly, we find that PLP is specifically enriched in the outer-most regions of the PCM, where it largely co-localizes with the PCM scaffold protein Cnn. In the absence of PLP the outer PCM appears to be structurally weakened, and it rapidly disperses along the centrosomal microtubules (MTs). As a result, centrosomal MTs are subtly disorganized in embryos lacking PLP, although mitosis is largely unperturbed and these embryos develop and hatch at near-normal rates. Y2H analysis reveals that PLP can potentially form multiple interactions with itself and with the PCM recruiting proteins Asl, Spd-2 and Cnn. A deletion analysis suggests that PLP participates in a complex network of interactions that ultimately help to strengthen the PCM. PMID:26157019

The Drosophila Pericentrin-like-protein (PLP) cooperates with Cnn to maintain the integrity of the outer PCM.

PubMed

Richens, Jennifer H; Barros, Teresa P; Lucas, Eliana P; Peel, Nina; Pinto, David Miguel Susano; Wainman, Alan; Raff, Jordan W

2015-07-08

Centrosomes comprise a pair of centrioles surrounded by a matrix of pericentriolar material (PCM). In vertebrate cells, Pericentrin plays an important part in mitotic PCM assembly, but the Drosophila Pericentrin-like protein (PLP) appears to have a more minor role in mitotic fly cells. Here we investigate the function of PLP during the rapid mitotic cycles of the early Drosophila embryo. Unexpectedly, we find that PLP is specifically enriched in the outer-most regions of the PCM, where it largely co-localizes with the PCM scaffold protein Cnn. In the absence of PLP the outer PCM appears to be structurally weakened, and it rapidly disperses along the centrosomal microtubules (MTs). As a result, centrosomal MTs are subtly disorganized in embryos lacking PLP, although mitosis is largely unperturbed and these embryos develop and hatch at near-normal rates. Y2H analysis reveals that PLP can potentially form multiple interactions with itself and with the PCM recruiting proteins Asl, Spd-2 and Cnn. A deletion analysis suggests that PLP participates in a complex network of interactions that ultimately help to strengthen the PCM. © 2015. Published by The Company of Biologists Ltd.

A Novel In Vitro Method for Detecting Undifferentiated Human Pluripotent Stem Cells as Impurities in Cell Therapy Products Using a Highly Efficient Culture System

PubMed Central

Tano, Keiko; Yasuda, Satoshi; Kuroda, Takuya; Saito, Hirohisa; Umezawa, Akihiro; Sato, Yoji

2014-01-01

Innovative applications of cell therapy products (CTPs) derived from human pluripotent stem cells (hPSCs) in regenerative medicine are currently being developed. The presence of residual undifferentiated hPSCs in CTPs is a quality concern associated with tumorigencity. However, no simple in vitro method for direct detection of undifferentiated hPSCs that contaminate CTPs has been developed. Here, we show a novel approach for direct and sensitive detection of a trace amount of undifferentiated human induced pluripotent stem cells (hiPSCs) using a highly efficient amplification method in combination with laminin-521 and Essential 8 medium. Essential 8 medium better facilitated the growth of hiPSCs dissociated into single cells on laminin-521 than in mTeSR1 medium. hiPSCs cultured on laminin-521 in Essential 8 medium were maintained in an undifferentiated state and they maintained the ability to differentiate into various cell types. Essential 8 medium allowed robust hiPSC proliferation plated on laminin-521 at low cell density, whereas mTeSR1 did not enhance the cell growth. The highly efficient culture system using laminin-521 and Essential 8 medium detected hiPSCs spiked into primary human mesenchymal stem cells (hMSCs) or human neurons at the ratio of 0.001%–0.01% as formed colonies. Moreover, this assay method was demonstrated to detect residual undifferentiated hiPSCs in cell preparations during the process of hMSC differentiation from hiPSCs. These results indicate that our highly efficient amplification system using a combination of laminin-521 and Essential 8 medium is able to detect a trace amount of undifferentiated hPSCs contained as impurities in CTPs and would contribute to quality assessment of hPSC-derived CTPs during the manufacturing process. PMID:25347300

Transplant of Hepatocytes, Undifferentiated Mesenchymal Stem Cells, and In Vitro Hepatocyte-Differentiated Mesenchymal Stem Cells in a Chronic Liver Failure Experimental Model: A Comparative Study.

PubMed

El Baz, Hanan; Demerdash, Zeinab; Kamel, Manal; Atta, Shimaa; Salah, Faten; Hassan, Salwa; Hammam, Olfat; Khalil, Heba; Meshaal, Safa; Raafat, Inas

2018-02-01

Liver transplant is the cornerstone line of treatment for chronic liver diseases; however, the long list of complications and obstacles stand against this operation. Searching for new modalities for treatment of chronic liver illness is a must. In the present research, we aimed to compare the effects of transplant of undifferentiated human mesenchymal stem cells, in vitro differentiated mesenchymal stem cells, and adult hepatocytes in an experimental model of chronic liver failure. Undifferentiated human cord blood mesenchymal stem cells were isolated, pro-pagated, and characterized by morphology, gene expression analysis, and flow cytometry of surface markers and in vitro differentiated into hepatocyte-like cells. Rat hepatocytes were isolated by double perfusion technique. An animal model of chronic liver failure was developed, and undifferentiated human cord blood mesenchymal stem cells, in vitro hepato-genically differentiated mesenchymal stem cells, or freshly isolated rat hepatocytes were transplanted into a CCL4 cirrhotic experimental model. Animals were killed 3 months after transplant, and liver functions and histopathology were assessed. Compared with the cirrhotic control group, the 3 cell-treated groups showed improved alanine aminotransferase, aspartate aminotransferase, albumin, and bilirubin levels, with best results shown in the hepatocyte-treated group. Histopathologic examination of the treated groups showed improved fibrosis, with best results obtained in the undifferentiated mesenchymal stem cell-treated group. Both adult hepatocytes and cord blood mesenchymal stem cells proved to be promising candidates for cell-based therapy in liver regeneration on an experimental level. Improved liver function was evident in the hepatocyte-treated group, and fibrosis control was more evident in the undifferentiated mesenchymal stem cell-treated group.

Carboplatin, Paclitaxel and Gemcitabine Hydrochloride With or Without Bevacizumab After Surgery in Treating Patients With Recurrent Ovarian, Epithelial, Primary Peritoneal, or Fallopian Tube Cancer

ClinicalTrials.gov

2018-06-06

Clear Cell Adenocarcinoma; Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Adenocarcinoma; Fallopian Tube Mucinous Adenocarcinoma; Fallopian Tube Serous Adenocarcinoma; Mucinous Adenocarcinoma; Ovarian Brenner Tumor; Ovarian Clear Cell Adenocarcinofibroma; Ovarian Endometrioid Adenocarcinoma; Ovarian Seromucinous Carcinoma; Ovarian Serous Adenocarcinoma; Primary Peritoneal Serous Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Carcinoma; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Striking circadian neuron diversity and cycling of Drosophila alternative splicing.

PubMed

Wang, Qingqing; Abruzzi, Katharine C; Rosbash, Michael; Rio, Donald C

2018-06-04

Although alternative pre-mRNA splicing (AS) significantly diversifies the neuronal proteome, the extent of AS is still unknown due in part to the large number of diverse cell types in the brain. To address this complexity issue, we used an annotation-free computational method to analyze and compare the AS profiles between small specific groups of Drosophila circadian neurons. The method, the J unction U sage M odel (JUM), allows the comprehensive profiling of both known and novel AS events from specific RNA-seq libraries. The results show that many diverse and novel pre-mRNA isoforms are preferentially expressed in one class of clock neuron and also absent from the more standard Drosophila head RNA preparation. These AS events are enriched in potassium channels important for neuronal firing, and there are also cycling isoforms with no detectable underlying transcriptional oscillations. The results suggest massive AS regulation in the brain that is also likely important for circadian regulation. © 2018, Wang et al.

Identification of ER Proteins Involved in the Functional Organisation of the Early Secretory Pathway in Drosophila Cells by a Targeted RNAi Screen

PubMed Central

Kondylis, Vangelis; Tang, Yang; Fuchs, Florian; Boutros, Michael; Rabouille, Catherine

2011-01-01

Background In Drosophila, the early secretory apparatus comprises discrete paired Golgi stacks in close proximity to exit sites from the endoplasmic reticulum (tER sites), thus forming tER-Golgi units. Although many components involved in secretion have been identified, the structural components sustaining its organisation are less known. Here we set out to identify novel ER resident proteins involved in the of tER-Golgi unit organisation. Results To do so, we designed a novel screening strategy combining a bioinformatics pre-selection with an RNAi screen. We first selected 156 proteins exhibiting known or related ER retention/retrieval signals from a list of proteins predicted to have a signal sequence. We then performed a microscopy-based primary and confirmation RNAi screen in Drosophila S2 cells directly scoring the organisation of the tER-Golgi units. We identified 49 hits, most of which leading to an increased number of smaller tER-Golgi units (MG for “more and smaller Golgi”) upon depletion. 16 of them were validated and characterised, showing that this phenotype was not due to an inhibition in secretion, a block in G2, or ER stress. Interestingly, the MG phenotype was often accompanied by an increase in the cell volume. Out of 6 proteins, 4 were localised to the ER. Conclusions This work has identified novel proteins involved in the organisation of the Drosophila early secretory pathway. It contributes to the effort of assigning protein functions to gene annotation in the secretory pathway, and analysis of the MG hits revealed an enrichment of ER proteins. These results suggest a link between ER localisation, aspects of cell metabolism and tER-Golgi structural organisation. PMID:21383842

Identification of ER proteins involved in the functional organisation of the early secretory pathway in Drosophila cells by a targeted RNAi screen.

PubMed

Kondylis, Vangelis; Tang, Yang; Fuchs, Florian; Boutros, Michael; Rabouille, Catherine

2011-02-23

In Drosophila, the early secretory apparatus comprises discrete paired Golgi stacks in close proximity to exit sites from the endoplasmic reticulum (tER sites), thus forming tER-Golgi units. Although many components involved in secretion have been identified, the structural components sustaining its organisation are less known. Here we set out to identify novel ER resident proteins involved in the of tER-Golgi unit organisation. To do so, we designed a novel screening strategy combining a bioinformatics pre-selection with an RNAi screen. We first selected 156 proteins exhibiting known or related ER retention/retrieval signals from a list of proteins predicted to have a signal sequence. We then performed a microscopy-based primary and confirmation RNAi screen in Drosophila S2 cells directly scoring the organisation of the tER-Golgi units. We identified 49 hits, most of which leading to an increased number of smaller tER-Golgi units (MG for "more and smaller Golgi") upon depletion. 16 of them were validated and characterised, showing that this phenotype was not due to an inhibition in secretion, a block in G2, or ER stress. Interestingly, the MG phenotype was often accompanied by an increase in the cell volume. Out of 6 proteins, 4 were localised to the ER. This work has identified novel proteins involved in the organisation of the Drosophila early secretory pathway. It contributes to the effort of assigning protein functions to gene annotation in the secretory pathway, and analysis of the MG hits revealed an enrichment of ER proteins. These results suggest a link between ER localisation, aspects of cell metabolism and tER-Golgi structural organisation.

NADPH oxidase-mediated generation of reactive oxygen species is critically required for survival of undifferentiated human promyelocytic leukemia cell line HL-60.

PubMed

Dong, Jing-Mei; Zhao, Sheng-Guo; Huang, Guo-Yin; Liu, Qing

2004-06-01

Nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) mediated generation of reactive oxygen species (ROS) was originally identified as the powerful host defense machinery against microorganism in phagocytes. But recent reports indicated that some non-phagocytic cells also have the NADPH oxidase activity, and the ROS produced by it may act as cell signal molecule. But as far as today, whether the NADPH oxidase also plays similar role in phagocyte has not been paid much attention. Utilizing the undifferentiated HL-60 promyelocytic leukemia cells as a model, the aim of the present study was to determine whether NADPH oxidase plays a role on ROS generation in undifferentiated HL-60, and the ROS mediated by it was essential for cell's survival. For the first time, we verified that the release of ROS in undifferentiated HL-60 was significantly increased by the stimulation with Calcium ionophore or opsonized zymosan, which are known to trigger respiration burst in phagocytes by NADPH oxidase pathway. Diphenylene iodonium (DPI) or apocynin (APO), two inhibitors of NADPH oxidase, significantly suppressed the increasing of ROS caused by opsonized zymosan. Cell survival assay and fluorescence double dyeing with acridine orange and ethidium bromide showed that DPI and APO, as well as superoxide dismutase (SOD) and catalase (CAT) concentration-dependently decreased the viability of undifferentiated HL-60 cells, whereas exogenous H2O2 can rescue the cells from death obviously. Our results suggested that the ROS, generated by NADPH oxidase play an essential role in the survival of undifferentiated HL-60 cells.

A Simple and Robust Method for Culturing Human-Induced Pluripotent Stem Cells in an Undifferentiated State Using Botulinum Hemagglutinin.

PubMed

Kim, Mee-Hae; Matsubara, Yoshifumi; Fujinaga, Yukako; Kino-Oka, Masahiro

2018-02-01

Clinical and industrial applications of human-induced pluripotent stem cells (hiPSCs) is hindered by the lack of robust culture strategies capable of sustaining a culture in an undifferentiated state. Here, a simple and robust hiPSC-culture-propagation strategy incorporating botulinum hemagglutinin (HA)-mediated selective removal of cells deviating from an undifferentiated state is developed. After HA treatment, cell-cell adhesion is disrupted, and deviated cells detached from the central region of the colony to subsequently form tight monolayer colonies following prolonged incubation. The authors find that the temporal and dose-dependent activity of HA regulated deviated-cell removal and recoverability after disruption of cell-cell adhesion in hiPSC colonies. The effects of HA are confirmed under all culture conditions examined, regardless of hiPSC line and feeder-dependent or -free culture conditions. After routine application of our HA-treatment paradigm for serial passages, hiPSCs maintains expression of pluripotent markers and readily forms embryoid bodies expressing markers for all three germ-cell layers. This method enables highly efficient culturing of hiPSCs and use of entire undifferentiated portions without having to pick deviated cells manually. This simple and readily reproducible culture strategy is a potentially useful tool for improving the robust and scalable maintenance of undifferentiated hiPSC cultures. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The transcriptional diversity of 25 Drosophila cell lines

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

Cherbas, Lucy; Willingham, Aarron; Zhang, Dayu

2010-12-22

Drosophila melanogaster cell lines are important resources for cell biologists. In this article, we catalog the expression of exons, genes, and unannotated transcriptional signals for 25 lines. Unannotated transcription is substantial (typically 19% of euchromatic signal). Conservatively, we identify 1405 novel transcribed regions; 684 of these appear to be new exons of neighboring, often distant, genes. Sixty-four percent of genes are expressed detectably in at least one line, but only 21% are detected in all lines. Each cell line expresses, on average, 5885 genes, including a common set of 3109. Expression levels vary over several orders of magnitude. Major signalingmore » pathways are well represented: most differentiation pathways are ‘‘off’’ and survival/growth pathways ‘‘on.’’ Roughly 50% of the genes expressed by each line are not part of the common set, and these show considerable individuality. Thirty-one percent are expressed at a higher level in at least one cell line than in any single developmental stage, suggesting that each line is enriched for genes characteristic of small sets of cells. Most remarkable is that imaginal disc-derived lines can generally be assigned, on the basis of expression, to small territories within developing discs. These mappings reveal unexpected stability of even fine-grained spatial determination. No two cell lines show identical transcription factor expression. We conclude that each line has retained features of an individual founder cell superimposed on a common ‘‘cell line‘‘ gene expression pattern. We report the transcriptional profiles of 25 Drosophila melanogaster cell lines, principally by whole-genome tiling microarray analysis of total RNA, carried out as part of the modENCODE project. The data produced in this study add to our knowledge of the cell lines and of the Drosophila transcriptome in several ways. We summarize the expression of previously annotated genes in each of the 25 lines with emphasis on what those patterns reveal about the origins of the lines and the stability of spatial expression patterns. In addition, we offer an initial analysis of previously unannotated transcripts in the cell lines.« less

The differentiation and isolation of mouse embryonic stem cells toward hepatocytes using galactose-carrying substrata.

PubMed

Meng, Qingyuan; Haque, Amranul; Hexig, Bayar; Akaike, Toshihiro

2012-02-01

A simple culture system to achieve the differentiation of embryonic stem (ES) cells toward hepatocytes with high efficiency is crucial in providing a cell source for the medical application. In this study, we report the effect of a matrix-dependent enrichment of ES cell-derived hepatocytes using immobilized poly(N-p-vinylbenzyl-4-O-β-D-galactopyranosyl-D-gluconamide) (PVLA) with E-cadherin-IgG Fc (E-cad-Fc) as a galactose-carrying substratum. PVLA and E-cad-Fc were confirmed to be stably co-adsorbed onto polystyrene surface by quartz crystal microbalance (QCM). We showed that the E-cad-Fc/PVLA hybrid substratum was efficient in culturing primary hepatocytes and maintaining liver functions, on which the undifferentiated ES cells also maintained high proliferative capability. Furthermore, ES cell-derived hepatocytes on this hybrid matrix expressed elevated level of liver specific genes and functions together with early expression of definitive hepatocyte marker, asialoglycoprotein receptor (ASGPR). Finally, we isolated a high percentage of cells (about 60%) with ASGPR expression after re-seeding onto PVLA-coated surface, and observed the elimination of the poorly differentiated cells (Gata6(+) and Sox17(+)) and the ones toward another cell lineage (brachyury(+) and Pdx1(+)). The system uses a glycopolymer as an extracellular substratum for isolation and enrichment of ES cell-derived hepatocytes with adequate homogeneity and functionality. Copyright © 2011 Elsevier Ltd. All rights reserved.

Transcriptomic Analysis in a Drosophila Model Identifies Previously Implicated and Novel Pathways in the Therapeutic Mechanism in Neuropsychiatric Disorders

PubMed Central

Singh, Priyanka; Mohammad, Farhan; Sharma, Abhay

2011-01-01

We have taken advantage of a newly described Drosophila model to gain insights into the potential mechanism of antiepileptic drugs (AEDs), a group of drugs that are widely used in the treatment of several neurological and psychiatric conditions besides epilepsy. In the recently described Drosophila model that is inspired by pentylenetetrazole (PTZ) induced kindling epileptogenesis in rodents, chronic PTZ treatment for 7 days causes a decreased climbing speed and an altered CNS transcriptome, with the latter mimicking gene expression alterations reported in epileptogenesis. In the model, an increased climbing speed is further observed 7 days after withdrawal from chronic PTZ. We used this post-PTZ withdrawal regime to identify potential AED mechanism. In this regime, treatment with each of the five AEDs tested, namely, ethosuximide, gabapentin, vigabatrin, sodium valproate, and levetiracetam, resulted in rescuing of the altered climbing behavior. The AEDs also normalized PTZ withdrawal induced transcriptomic perturbation in fly heads; whereas AED untreated flies showed a large number of up- and down-regulated genes which were enriched in several processes including gene expression and cell communication, the AED treated flies showed differential expression of only a small number of genes that did not enrich gene expression and cell communication processes. Gene expression and cell communication related upregulated genes in AED untreated flies overrepresented several pathways – spliceosome, RNA degradation, and ribosome in the former category, and inositol phosphate metabolism, phosphatidylinositol signaling, endocytosis, and hedgehog signaling in the latter. Transcriptome remodeling effect of AEDs was overall confirmed by microarray clustering that clearly separated the profiles of AED treated and untreated flies. Besides being consistent with previously implicated pathways, our results provide evidence for a role of other pathways in psychiatric drug mechanism. Overall, we provide an amenable model to understand neuropsychiatric mechanism in cellular and molecular terms. PMID:21503142

Thalidomide induces apoptosis in undifferentiated human induced pluripotent stem cells.

PubMed

Tachikawa, Saoko; Nishimura, Toshinobu; Nakauchi, Hiromitsu; Ohnuma, Kiyoshi

2017-10-01

Thalidomide, which was formerly available commercially to control the symptoms of morning sickness, is a strong teratogen that causes fetal abnormalities. However, the mechanism of thalidomide teratogenicity is not fully understood; thalidomide toxicity is not apparent in rodents, and the use of human embryos is ethically and technically untenable. In this study, we designed an experimental system featuring human-induced pluripotent stem cells (hiPSCs) to investigate the effects of thalidomide. These cells exhibit the same characteristics as those of epiblasts originating from implanted fertilized ova, which give rise to the fetus. Therefore, theoretically, thalidomide exposure during hiPSC differentiation is equivalent to that in the human fetus. We examined the effects of thalidomide on undifferentiated hiPSCs and early-differentiated hiPSCs cultured in media containing bone morphogenetic protein-4, which correspond, respectively, to epiblast (future fetus) and trophoblast (future extra-embryonic tissue). We found that only the number of undifferentiated cells was reduced. In undifferentiated cells, application of thalidomide increased the number of apoptotic and dead cells at day 2 but not day 4. Application of thalidomide did not affect the cell cycle. Furthermore, immunostaining and flow cytometric analysis revealed that thalidomide exposure had no effect on the expression of specific markers of undifferentiated and early trophectodermal differentiated cells. These results suggest that the effect of thalidomide was successfully detected in our experimental system and that thalidomide eliminated a subpopulation of undifferentiated hiPSCs. This study may help to elucidate the mechanisms underlying thalidomide teratogenicity and reveal potential strategies for safely prescribing this drug to pregnant women.

Sequence-Specific Targeting of Dosage Compensation in Drosophila Favors an Active Chromatin Context

PubMed Central

Gelbart, Marnie; Tolstorukov, Michael Y.; Plachetka, Annette; Kharchenko, Peter V.; Jung, Youngsook L.; Gorchakov, Andrey A.; Larschan, Erica; Gu, Tingting; Minoda, Aki; Riddle, Nicole C.; Schwartz, Yuri B.; Elgin, Sarah C. R.; Karpen, Gary H.; Pirrotta, Vincenzo; Kuroda, Mitzi I.; Park, Peter J.

2012-01-01

The Drosophila MSL complex mediates dosage compensation by increasing transcription of the single X chromosome in males approximately two-fold. This is accomplished through recognition of the X chromosome and subsequent acetylation of histone H4K16 on X-linked genes. Initial binding to the X is thought to occur at “entry sites” that contain a consensus sequence motif (“MSL recognition element” or MRE). However, this motif is only ∼2 fold enriched on X, and only a fraction of the motifs on X are initially targeted. Here we ask whether chromatin context could distinguish between utilized and non-utilized copies of the motif, by comparing their relative enrichment for histone modifications and chromosomal proteins mapped in the modENCODE project. Through a comparative analysis of the chromatin features in male S2 cells (which contain MSL complex) and female Kc cells (which lack the complex), we find that the presence of active chromatin modifications, together with an elevated local GC content in the surrounding sequences, has strong predictive value for functional MSL entry sites, independent of MSL binding. We tested these sites for function in Kc cells by RNAi knockdown of Sxl, resulting in induction of MSL complex. We show that ectopic MSL expression in Kc cells leads to H4K16 acetylation around these sites and a relative increase in X chromosome transcription. Collectively, our results support a model in which a pre-existing active chromatin environment, coincident with H3K36me3, contributes to MSL entry site selection. The consequences of MSL targeting of the male X chromosome include increase in nucleosome lability, enrichment for H4K16 acetylation and JIL-1 kinase, and depletion of linker histone H1 on active X-linked genes. Our analysis can serve as a model for identifying chromatin and local sequence features that may contribute to selection of functional protein binding sites in the genome. PMID:22570616

Development of Novel Monoclonal Antibodies that Define Differentiation Stages of Human Stromal (Mesenchymal) Stem Cells

PubMed Central

Andersen, Ditte C.; Kortesidis, Angela; Zannettino, Andrew C.W.; Kratchmarova, Irina; Chen, Li; Jensen, Ole N.; Teisner, Børge; Gronthos, Stan; Jensen, Charlotte H.; Kassem, Moustapha

2011-01-01

Human mesenchymal stem cells (hMSC) are currently being introduced for cell therapy, yet, antibodies specific for native and differentiated MSCs are required for their identification prior to clinical use. Herein, high quality antibodies against MSC surface proteins were developed by immunizing mice with hMSC, and by using a panel of subsequent screening methods. Flow cytometry analysis revealed that 83.5, 1.1, and 8.5% of primary cultures of hMSC were double positive for STRO-1 and either of DJ 3, 9, and 18, respectively. However, none of the three DJ antibodies allowed enrichment of clonogenic hMSC from BMMNCs as single reagents. Using mass-spectrometric analysis, we identified the antigen recognised by DJ3 as CD44, whereas DJ9 and DJ18 recognized HLA-DRB1 and Collagen VI, respectively. The identified proteins were highly expressed throughout in vitro osteogenic- and adipogenic differentiation. Interestingly, undifferentiated cells revealed a sole cytoplasmic distribution pattern of Collagen VI, which however changed to an extracellular matrix appearance upon osteogenic- and adipogenic differentiation. In relation to this, we found that STRO-1+/-/Collagen VI- sorted hMSC contained fewer differentiated alkaline phosphatase + cells compared to STRO-1+/-/Collagen VI+ hMSC, suggesting that Collagen VI on the cell membrane exclusively defines differentiated MSCs. In conclusion, we have generated a panel of high quality antibodies to be used for characterization of MSCs, and in addition our results may suggest that the DJ18 generated antibody against Collagen VI can be used for negative selection of cultured undifferentiated MSCs. PMID:21614487

Vorinostat and Azacitidine in Treating Patients With Locally Recurrent or Metastatic Nasopharyngeal Cancer or Nasal Natural Killer T-Cell Lymphoma

ClinicalTrials.gov

2018-04-20

Adult Nasal Type Extranodal NK/T-Cell Lymphoma; Recurrent Nasopharyngeal Keratinizing Squamous Cell Carcinoma; Recurrent Nasopharyngeal Undifferentiated Carcinoma; Stage IV Nasopharyngeal Keratinizing Squamous Cell Carcinoma AJCC v7; Stage IV Nasopharyngeal Undifferentiated Carcinoma AJCC v7

Phosphoproteomics profiling suggests a role for nuclear βΙPKC in transcription processes of undifferentiated murine embryonic stem cells.

PubMed

Costa-Junior, Helio Miranda; Garavello, Nicole Milaré; Duarte, Mariana Lemos; Berti, Denise Aparecida; Glaser, Talita; de Andrade, Alexander; Labate, Carlos A; Ferreira, André Teixeira da Silva; Perales, Jonas Enrique Aguilar; Xavier-Neto, José; Krieger, José Eduardo; Schechtman, Deborah

2010-12-03

Protein kinase C (PKC) plays a key role in embryonic stem cell (ESC) proliferation, self-renewal, and differentiation. However, the function of specific PKC isoenzymes have yet to be determined. Of the PKCs expressed in undifferentiated ESCs, βIPKC was the only isoenzyme abundantly expressed in the nuclei. To investigate the role of βΙPKC in these cells, we employed a phosphoproteomics strategy and used two classical (cPKC) peptide modulators and one βIPKC-specific inhibitor peptide. We identified 13 nuclear proteins that are direct or indirect βΙPKC substrates in undifferentiated ESCs. These proteins are known to be involved in regulating transcription, splicing, and chromatin remodeling during proliferation and differentiation. Inhibiting βΙPKC had no effect on DNA synthesis in undifferentiated ESCs. However, upon differentiation, many cells seized to express βΙPKC and βΙPKC was frequently found in the cytoplasm. Taken together, our results suggest that βIPKC takes part in the processes that maintain ESCs in their undifferentiated state.

Tissue-enriched expression profiles in Aedes aegypti identify hemocyte-specific transcriptome responses to infection

PubMed Central

Choi, Young-Jun; Fuchs, Jeremy F.; Mayhew, George F.; Yu, Helen E.; Christensen, Bruce M.

2012-01-01

Hemocytes are integral components of mosquito immune mechanisms such as phagocytosis, melanization, and production of antimicrobial peptides. However, our understanding of hemocyte-specific molecular processes and their contribution to shaping the host immune response remains limited. To better understand the immunophysiological features distinctive of hemocytes, we conducted genome-wide analysis of hemocyte-enriched transcripts, and examined how tissue-enriched expression patterns change with the immune status of the host. Our microarray data indicate that the hemocyte-enriched trascriptome is dynamic and context-dependent. Analysis of transcripts enriched after bacterial challenge in circulating hemocytes with respect to carcass added a dimension to evaluating infection-responsive genes and immune-related gene families. We resolved patterns of transcriptional change unique to hemocytes from those that are likely shared by other immune responsive tissues, and identified clusters of genes preferentially induced in hemocytes, likely reflecting their involvement in cell type specific functions. In addition, the study revealed conserved hemocyte-enriched molecular repertoires which might be implicated in core hemocyte function by cross-species meta-analysis of microarray expression data from Anopheles gambiae and Drosophila melanogaster. PMID:22796331

TGF-β1-Induced Epithelial–Mesenchymal Transition Promotes Monocyte/Macrophage Properties in Breast Cancer Cells

PubMed Central

Johansson, Joel; Tabor, Vedrana; Wikell, Anna; Jalkanen, Sirpa; Fuxe, Jonas

2015-01-01

Breast cancer progression toward metastatic disease is linked to re-activation of epithelial–mesenchymal transition (EMT), a latent developmental process. Breast cancer cells undergoing EMT lose epithelial characteristics and gain the capacity to invade the surrounding tissue and migrate away from the primary tumor. However, less is known about the possible role of EMT in providing cancer cells with properties that allow them to traffic to distant sites. Given the fact that pro-metastatic cancer cells share a unique capacity with immune cells to traffic in-and-out of blood and lymphatic vessels we hypothesized that tumor cells undergoing EMT may acquire properties of immune cells. To study this, we performed gene-profiling analysis of mouse mammary EpRas tumor cells that had been allowed to adopt an EMT program after long-term treatment with TGF-β1 for 2 weeks. As expected, EMT cells acquired traits of mesenchymal cell differentiation and migration. However, in addition, we found another cluster of induced genes, which was specifically enriched in monocyte-derived macrophages, mast cells, and myeloid dendritic cells, but less in other types of immune cells. Further studies revealed that this monocyte/macrophage gene cluster was enriched in human breast cancer cell lines displaying an EMT or a Basal B profile, and in human breast tumors with EMT and undifferentiated (ER−/PR−) characteristics. The results identify an EMT-induced monocyte/macrophage gene cluster, which may play a role in breast cancer cell dissemination and metastasis. PMID:25674539

Drosophila's contribution to stem cell research.

PubMed

Singh, Gyanesh

2015-01-01

The discovery of Drosophila stem cells with striking similarities to mammalian stem cells has brought new hope for stem cell research. Recent developments in Drosophila stem cell research is bringing wider opportunities for contemporary stem cell biologists. In this regard, Drosophila germ cells are becoming a popular model of stem cell research. In several cases, genes that controlled Drosophila stem cells were later discovered to have functional homologs in mammalian stem cells. Like mammals, Drosophila germline stem cells (GSCs) are controlled by both intrinsic as well as external signals. Inside the Drosophila testes, germline and somatic stem cells form a cluster of cells (the hub). Hub cells depend on JAK-STAT signaling, and, in absence of this signal, they do not self-renew. In Drosophila, significant changes occur within the stem cell niche that contributes to a decline in stem cell number over time. In case of aging Drosophila, somatic niche cells show reduced DE-cadherin and unpaired (Upd) proteins. Unpaired proteins are known to directly decrease stem cell number within the niches, and, overexpression of upd within niche cells restored GSCs in older males also . Stem cells in the midgut of Drosophila are also very promising. Reduced Notch signaling was found to increase the number of midgut progenitor cells. On the other hand, activation of the Notch pathway decreased proliferation of these cells. Further research in this area should lead to the discovery of additional factors that regulate stem and progenitor cells in Drosophila.

Drosophila's contribution to stem cell research

PubMed Central

Singh, Gyanesh

2016-01-01

The discovery of Drosophila stem cells with striking similarities to mammalian stem cells has brought new hope for stem cell research. Recent developments in Drosophila stem cell research is bringing wider opportunities for contemporary stem cell biologists. In this regard, Drosophila germ cells are becoming a popular model of stem cell research. In several cases, genes that controlled Drosophila stem cells were later discovered to have functional homologs in mammalian stem cells. Like mammals, Drosophila germline stem cells (GSCs) are controlled by both intrinsic as well as external signals. Inside the Drosophila testes, germline and somatic stem cells form a cluster of cells (the hub). Hub cells depend on JAK-STAT signaling, and, in absence of this signal, they do not self-renew. In Drosophila, significant changes occur within the stem cell niche that contributes to a decline in stem cell number over time. In case of aging Drosophila, somatic niche cells show reduced DE-cadherin and unpaired (Upd) proteins. Unpaired proteins are known to directly decrease stem cell number within the niches, and, overexpression of upd within niche cells restored GSCs in older males also . Stem cells in the midgut of Drosophila are also very promising. Reduced Notch signaling was found to increase the number of midgut progenitor cells. On the other hand, activation of the Notch pathway decreased proliferation of these cells. Further research in this area should lead to the discovery of additional factors that regulate stem and progenitor cells in Drosophila. PMID:26180635

Rap1, Canoe and Mbt cooperate with Bazooka to promote zonula adherens assembly in the fly photoreceptor

PubMed Central

Burki, Mubarik

2018-01-01

ABSTRACT In Drosophila epithelial cells, apical exclusion of Bazooka (the Drosophila Par3 protein) defines the position of the zonula adherens (ZA), which demarcates the apical and lateral membrane and allows cells to assemble into sheets. Here, we show that the small GTPase Rap1, its effector Canoe (Cno) and the Cdc42 effector kinase Mushroom bodies tiny (Mbt), converge in regulating epithelial morphogenesis by coupling stabilization of the adherens junction (AJ) protein E-Cadherin and Bazooka retention at the ZA. Furthermore, our results show that the localization of Rap1, Cno and Mbt at the ZA is interdependent, indicating that their functions during ZA morphogenesis are interlinked. In this context, we find the Rap1-GEF Dizzy is enriched at the ZA and our results suggest that it promotes Rap1 activity during ZA morphogenesis. Altogether, we propose the Dizzy, Rap1 and Cno pathway and Mbt converge in regulating the interface between Bazooka and AJ material to promote ZA morphogenesis. PMID:29507112

The apical scaffold big bang binds to spectrins and regulates the growth of Drosophila melanogaster wing discs.

PubMed

Forest, Elodie; Logeay, Rémi; Géminard, Charles; Kantar, Diala; Frayssinoux, Florence; Heron-Milhavet, Lisa; Djiane, Alexandre

2018-03-05

During development, cell numbers are tightly regulated, ensuring that tissues and organs reach their correct size and shape. Recent evidence has highlighted the intricate connections between the cytoskeleton and the regulation of the key growth control Hippo pathway. Looking for apical scaffolds regulating tissue growth, we describe that Drosophila melanogaster big bang (Bbg), a poorly characterized multi-PDZ scaffold, controls epithelial tissue growth without affecting epithelial polarity and architecture. bbg -mutant tissues are smaller, with fewer cells that are less apically constricted than normal. We show that Bbg binds to and colocalizes tightly with the β-heavy-Spectrin/Kst subunit at the apical cortex and promotes Yki activity, F-actin enrichment, and the phosphorylation of the myosin II regulatory light chain Spaghetti squash. We propose a model in which the spectrin cytoskeleton recruits Bbg to the cortex, where Bbg promotes actomyosin contractility to regulate epithelial tissue growth. © 2018 Forest et al.

Drosophila germ granules are structured and contain homotypic mRNA clusters

PubMed Central

Trcek, Tatjana; Grosch, Markus; York, Andrew; Shroff, Hari; Lionnet, Timothée; Lehmann, Ruth

2015-01-01

Germ granules, specialized ribonucleoprotein particles, are a hallmark of all germ cells. In Drosophila, an estimated 200 mRNAs are enriched in the germ plasm, and some of these have important, often conserved roles in germ cell formation, specification, survival and migration. How mRNAs are spatially distributed within a germ granule and whether their position defines functional properties is unclear. Here we show, using single-molecule FISH and structured illumination microscopy, a super-resolution approach, that mRNAs are spatially organized within the granule whereas core germ plasm proteins are distributed evenly throughout the granule. Multiple copies of single mRNAs organize into ‘homotypic clusters' that occupy defined positions within the center or periphery of the granule. This organization, which is maintained during embryogenesis and independent of the translational or degradation activity of mRNAs, reveals new regulatory mechanisms for germ plasm mRNAs that may be applicable to other mRNA granules. PMID:26242323

Nivolumab and Ipilimumab in Treating Patients With Rare Tumors

ClinicalTrials.gov

2018-06-27

Acinar Cell Carcinoma; Adenoid Cystic Carcinoma; Adrenal Cortex Carcinoma; Adrenal Gland Pheochromocytoma; Anal Canal Neuroendocrine Carcinoma; Anal Canal Undifferentiated Carcinoma; Appendix Mucinous Adenocarcinoma; Bartholin Gland Transitional Cell Carcinoma; Bladder Adenocarcinoma; Cervical Adenocarcinoma; Cholangiocarcinoma; Chordoma; Colorectal Squamous Cell Carcinoma; Desmoid-Type Fibromatosis; Endometrial Transitional Cell Carcinoma; Endometrioid Adenocarcinoma; Esophageal Neuroendocrine Carcinoma; Esophageal Undifferentiated Carcinoma; Extrahepatic Bile Duct Carcinoma; Fallopian Tube Adenocarcinoma; Fallopian Tube Transitional Cell Carcinoma; Fibromyxoid Tumor; Gastric Neuroendocrine Carcinoma; Gastric Squamous Cell Carcinoma; Gastrointestinal Stromal Tumor; Giant Cell Carcinoma; Intestinal Neuroendocrine Carcinoma; Intrahepatic Cholangiocarcinoma; Lung Carcinoid Tumor; Lung Sarcomatoid Carcinoma; Major Salivary Gland Carcinoma; Malignant Odontogenic Neoplasm; Malignant Peripheral Nerve Sheath Tumor; Malignant Testicular Sex Cord-Stromal Tumor; Metaplastic Breast Carcinoma; Metastatic Malignant Neoplasm of Unknown Primary Origin; Minimally Invasive Lung Adenocarcinoma; Mixed Mesodermal (Mullerian) Tumor; Mucinous Adenocarcinoma; Mucinous Cystadenocarcinoma; Nasal Cavity Adenocarcinoma; Nasal Cavity Carcinoma; Nasopharyngeal Carcinoma; Nasopharyngeal Papillary Adenocarcinoma; Nasopharyngeal Undifferentiated Carcinoma; Oral Cavity Carcinoma; Oropharyngeal Undifferentiated Carcinoma; Ovarian Adenocarcinoma; Ovarian Germ Cell Tumor; Ovarian Mucinous Adenocarcinoma; Ovarian Squamous Cell Carcinoma; Ovarian Transitional Cell Carcinoma; Pancreatic Acinar Cell Carcinoma; Pancreatic Neuroendocrine Carcinoma; Paraganglioma; Paranasal Sinus Adenocarcinoma; Paranasal Sinus Carcinoma; Parathyroid Gland Carcinoma; Pituitary Gland Carcinoma; Placental Choriocarcinoma; Placental-Site Gestational Trophoblastic Tumor; Primary Peritoneal High Grade Serous Adenocarcinoma; Pseudomyxoma Peritonei; Rare Disorder; Scrotal Squamous Cell Carcinoma; Seminal Vesicle Adenocarcinoma; Seminoma; Serous Cystadenocarcinoma; Small Intestinal Adenocarcinoma; Small Intestinal Squamous Cell Carcinoma; Spindle Cell Neoplasm; Squamous Cell Carcinoma of the Penis; Teratoma With Malignant Transformation; Testicular Non-Seminomatous Germ Cell Tumor; Thyroid Gland Carcinoma; Tracheal Carcinoma; Transitional Cell Carcinoma; Undifferentiated Gastric Carcinoma; Ureter Adenocarcinoma; Ureter Squamous Cell Carcinoma; Urethral Adenocarcinoma; Urethral Squamous Cell Carcinoma; Vaginal Adenocarcinoma; Vaginal Squamous Cell Carcinoma, Not Otherwise Specified; Vulvar Carcinoma

Embryonic origin of adult stem cells required for tissue homeostasis and regeneration

PubMed Central

Davies, Erin L; Lei, Kai; Seidel, Christopher W; Kroesen, Amanda E; McKinney, Sean A; Guo, Longhua; Robb, Sofia MC; Ross, Eric J; Gotting, Kirsten; Alvarado, Alejandro Sánchez

2017-01-01

Planarian neoblasts are pluripotent, adult somatic stem cells and lineage-primed progenitors that are required for the production and maintenance of all differentiated cell types, including the germline. Neoblasts, originally defined as undifferentiated cells residing in the adult parenchyma, are frequently compared to embryonic stem cells yet their developmental origin remains obscure. We investigated the provenance of neoblasts during Schmidtea mediterranea embryogenesis, and report that neoblasts arise from an anarchic, cycling piwi-1+ population wholly responsible for production of all temporary and definitive organs during embryogenesis. Early embryonic piwi-1+ cells are molecularly and functionally distinct from neoblasts: they express unique cohorts of early embryo enriched transcripts and behave differently than neoblasts in cell transplantation assays. Neoblast lineages arise as organogenesis begins and are required for construction of all major organ systems during embryogenesis. These subpopulations are continuously generated during adulthood, where they act as agents of tissue homeostasis and regeneration. DOI: http://dx.doi.org/10.7554/eLife.21052.001 PMID:28072387

Genetic Rescue of Functional Senescence in Synaptic and Behavioral Plasticity

PubMed Central

Donlea, Jeffrey M.; Ramanan, Narendrakumar; Silverman, Neal; Shaw, Paul J.

2014-01-01

Study Objectives: Aging has been linked with decreased neural plasticity and memory formation in humans and in laboratory model species such as the fruit fly, Drosophila melanogaster. Here, we examine plastic responses following social experience in Drosophila as a high-throughput method to identify interventions that prevent these impairments. Patients or Participants: Wild-type and transgenic Drosophila melanogaster. Design and Interventions: Young (5-day old) or aged (20-day old) adult female Drosophila were housed in socially enriched (n = 35-40) or isolated environments, then assayed for changes in sleep and for structural markers of synaptic terminal growth in the ventral lateral neurons (LNVs) of the circadian clock. Measurements and Results: When young flies are housed in a socially enriched environment, they exhibit synaptic elaboration within a component of the circadian circuitry, the LNVs, which is followed by increased sleep. Aged flies, however, no longer exhibit either of these plastic changes. Because of the tight correlation between neural plasticity and ensuing increases in sleep, we use sleep after enrichment as a high-throughput marker for neural plasticity to identify interventions that prolong youthful plasticity in aged flies. To validate this strategy, we find three independent genetic manipulations that delay age-related losses in plasticity: (1) elevation of dopaminergic signaling, (2) over-expression of the transcription factor blistered (bs) in the LNVs, and (3) reduction of the Imd immune signaling pathway. These findings provide proof-of-principle evidence that measuring changes in sleep in flies after social enrichment may provide a highly scalable assay for the study of age-related deficits in synaptic plasticity. Conclusions: These studies demonstrate that Drosophila provides a promising model for the study of age-related loss of neural plasticity and begin to identify genes that might be manipulated to delay the onset of functional senescence. Citation: Donlea JM, Ramanan N, Silverman N, Shaw PJ. Genetic rescue of functional senescence in synaptic and behavioral plasticity. SLEEP 2014;37(9):1427-1437. PMID:25142573

Apoptosis and cell proliferation in the development of gastric carcinomas: associations with c-myc and p53 protein expression.

PubMed

Ishii, Hideaki H; Gobé, Glenda C; Pan, Wenshen; Yoneyama, Juichi; Ebihara, Yoshiro

2002-09-01

Patients with gastric carcinomas have a poor prognosis and low survival rates. The aim of the present paper was to characterize cellular and molecular properties to provide insight into aspects of tumor progression in early compared with advanced gastric cancers. One hundred and nine graded gastric carcinomas (early or advanced stage, undifferentiated or differentiated type) with paired non-cancer tissue were studied to define the correlation between apoptosis (morphology, terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labeling), cell proliferation (Ki-67 expression, morphology) and expression and localization of two proteins frequently having altered expression in cancers, namely p53 and c-myc. Overall, apoptosis was lower in early stage, differentiated and undifferentiated gastric carcinomas compared with advanced-stage cancers. Cell proliferation was comparatively high in all stages. There was a high level of p53 positivity in all stages. Only the early- and advanced-stage undifferentiated cancers that were p53 positive had a significantly higher level of apoptosis (P < 0.05). Cell proliferation was significantly greater (P < 0.05) only in the early undifferentiated cancers that had either c-myc or p53-positivity. The results indicate that low apoptosis and high cell proliferation combine to drive gastric cancer development. The molecular controls for high cell proliferation of the early stage undifferentiated gastric cancers involve overexpression of both p53 and c-myc. Overexpression of p53 may also control cancer development in that its expression is associated with higher levels of apoptosis in early and late-stage undifferentiated, cancers. Copyright 2002 Blackwell Publishing Asia Pty Ltd

Paclitaxel Albumin-Stabilized Nanoparticle Formulation and Bevacizumab in Treating Patients With Stage IV Melanoma That Cannot Be Removed by Surgery or Gynecological Cancers

ClinicalTrials.gov

2018-02-05

Cervical Adenosarcoma; Cervical Adenosquamous Carcinoma; Cervical Carcinosarcoma; Cervical Squamous Cell Carcinoma, Not Otherwise Specified; Endometrial Clear Cell Adenocarcinoma; Endometrial Endometrioid Adenocarcinoma; Endometrial Mixed Adenocarcinoma; Endometrial Mucinous Adenocarcinoma; Endometrial Squamous Cell Carcinoma; Endometrial Transitional Cell Carcinoma; Endometrial Undifferentiated Carcinoma; Fallopian Tube Adenocarcinoma; Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Mucinous Adenocarcinoma; Fallopian Tube Serous Adenocarcinoma; Fallopian Tube Transitional Cell Carcinoma; Malignant Ovarian Epithelial Tumor; Malignant Peritoneal Neoplasm; Ovarian Carcinosarcoma; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Adenocarcinoma; Ovarian Serous Adenocarcinoma; Ovarian Transitional Cell Carcinoma; Primary Peritoneal Serous Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Melanoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Stage IV Skin Melanoma; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma; Uterine Corpus Carcinosarcoma

Down-regulated RPS3a/nbl expression during retinoid-induced differentiation of HL-60 cells: a close association with diminished susceptibility to actinomycin D-stimulated apoptosis.

PubMed

Russell, L; Naora, H; Naora, H

2000-04-01

The efficacy of anticancer agents significantly depends on the differential susceptibility of undifferentiated cancer cells and differentiated normal cells to undergo apoptosis. We previously found that enhanced expression of RPS3a/nbl, which apparently encodes a ribosomal protein, seems to prime cells for apoptosis, while suppressing such enhanced expression triggers cell death. The present study found that HL-60 cells induced to differentiate by all-trans retinoic acid did not undergo apoptosis following treatment with actinomycin D whereas undifferentiated HL-60 cells were highly apoptosis-susceptible, confirming earlier suggestions that differentiated cells have diminished apoptosis-susceptibility. Undifferentiated HL-60 cells highly expressed RPS3a/nbl whereas all-trans retinoic acid -induced differentiated cells exhibited markedly reduced levels, suggesting that apoptosis-resistance of differentiated cells could be due to low RPS3a/nbl expression. Down-regulation of enhanced RPS3a/nbl expression was also observed in cells induced to differentiate with the retinoid 4-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-napthalenyl)-1- propenyl]benzoic acid without any significant induction of cell death. While down-regulation of RPS3a/nbl expression during differentiation did not apparently induce apoptosis, RPS3a/nbl antisense oligomers triggered death of undifferentiated HL-60 cells, but not of retinoid-induced differentiated cells. It therefore seems that while down-regulation of enhanced RPS3a/nbl expression can induce apoptosis in undifferentiated cells, down-regulation of enhanced RPS3a/nbl expression during differentiation occurs independently of apoptosis, and could be regarded as reverting the primed condition to the unprimed (low RPS3a/nbl) state.

Cell segregation in the vertebrate hindbrain relies on actomyosin cables located at the interhombomeric boundaries

PubMed Central

Calzolari, Simone; Terriente, Javier; Pujades, Cristina

2014-01-01

Segregating cells into compartments during embryonic development is essential for growth and pattern formation. Physical mechanisms shaping compartment boundaries were recently explored in Drosophila, where actomyosin-based barriers were revealed to be important for keeping cells apart. In vertebrates, interhombomeric boundaries are straight interfaces, which often serve as signaling centers that pattern the surrounding tissue. Here, we demonstrate that in the hindbrain of zebrafish embryos cell sorting sharpens the molecular boundaries and, once borders are straight, actomyosin barriers are key to keeping rhombomeric cells segregated. Actomyosin cytoskeletal components are enriched at interhombomeric boundaries, forming cable-like structures in the apical side of the neuroepithelial cells by the time morphological boundaries are visible. When myosin II function is inhibited, cable structures do not form, leading to rhombomeric cell mixing. Downregulation of EphA4a compromises actomyosin cables and cells with different rhombomeric identity intermingle, and the phenotype is rescued enhancing myosin II activity. Moreover, enrichment of actomyosin structures is obtained when EphA4 is ectopically expressed in even-numbered rhombomeres. These findings suggest that mechanical barriers act downstream of EphA/ephrin signaling to segregate cells from different rhombomeres. PMID:24569501

The PSA−/lo prostate cancer cell population harbors self-renewing long-term tumor-propagating cells that resist castration

PubMed Central

Qin, Jichao; Liu, Xin; Laffin, Brian; Chen, Xin; Choy, Grace; Jeter, Collene; Calhoun-Davis, Tammy; Li, Hangwen; Palapattu, Ganesh S.; Pang, Shen; Lin, Kevin; Huang, Jiaoti; Ivanov, Ivan; Li, Wei; Suraneni, Mahipal V.; Tang, Dean G.

2012-01-01

SUMMARY Prostate cancer (PCa) is heterogeneous and contains both differentiated and undifferentiated tumor cells, but the relative functional contribution of these two cell populations remains unclear. Here we report distinct molecular, cellular, and tumor-propagating properties of PCa cells that express high (PSA+) and low (PSA−/lo) levels of the differentiation marker PSA. PSA−/lo PCa cells are quiescent and refractory to stresses including androgen deprivation, exhibit high clonogenic potential, and possess long-term tumor-propagating capacity. They preferentially express stem cell genes and can undergo asymmetric cell division generating PSA+ cells. Importantly, PSA−/lo PCa cells can initiate robust tumor development and resist androgen ablation in castrated hosts, and harbor highly tumorigenic castration-resistant PCa cells that can be prospectively enriched using ALDH+CD44+α2β1+ phenotype. In contrast, PSA+ PCa cells possess more limited tumor-propagating capacity, undergo symmetric division and are sensitive to castration. Together, our study suggests PSA−/lo cells may represent a critical source of castration-resistant PCa cells. PMID:22560078

mTORC1 is essential for leukemia propagation but not stem cell self-renewal

PubMed Central

Hoshii, Takayuki; Tadokoro, Yuko; Naka, Kazuhito; Ooshio, Takako; Muraguchi, Teruyuki; Sugiyama, Naoyuki; Soga, Tomoyoshi; Araki, Kimi; Yamamura, Ken-ichi; Hirao, Atsushi

2012-01-01

Although dysregulation of mTOR complex 1 (mTORC1) promotes leukemogenesis, how mTORC1 affects established leukemia is unclear. We investigated the role of mTORC1 in mouse hematopoiesis using a mouse model of conditional deletion of Raptor, an essential component of mTORC1. Raptor deficiency impaired granulocyte and B cell development but did not alter survival or proliferation of hematopoietic progenitor cells. In a mouse model of acute myeloid leukemia (AML), Raptor deficiency significantly suppressed leukemia progression by causing apoptosis of differentiated, but not undifferentiated, leukemia cells. mTORC1 did not control cell cycle or cell growth in undifferentiated AML cells in vivo. Transplantation of Raptor-deficient undifferentiated AML cells in a limiting dilution revealed that mTORC1 is essential for leukemia initiation. Strikingly, a subset of AML cells with undifferentiated phenotypes survived long-term in the absence of mTORC1 activity. We further demonstrated that the reactivation of mTORC1 in those cells restored their leukemia-initiating capacity. Thus, AML cells lacking mTORC1 activity can self-renew as AML stem cells. Our findings provide mechanistic insight into how residual tumor cells circumvent anticancer therapies and drive tumor recurrence. PMID:22622041

Pluripotency of adult stem cells derived from human and rat pancreas

NASA Astrophysics Data System (ADS)

Kruse, C.; Birth, M.; Rohwedel, J.; Assmuth, K.; Goepel, A.; Wedel, T.

Adult stem cells are undifferentiated cells found within fully developed tissues or organs of an adult individuum. Until recently, these cells have been considered to bear less self-renewal ability and differentiation potency compared to embryonic stem cells. In recent studies an undifferentiated cell type was found in primary cultures of isolated acini from exocrine pancreas termed pancreatic stellate cells. Here we show that pancreatic stellate-like cells have the capacity of extended self-renewal and are able to differentiate spontaneously into cell types of all three germ layers expressing markers for smooth muscle cells, neurons, glial cells, epithelial cells, chondrocytes and secretory cells (insulin, amylase). Differentiation and subsequent formation of three-dimensional cellular aggregates (organoid bodies) were induced by merely culturing pancreatic stellate-like cells in hanging drops. These cells were developed into stable, long-term, in vitro cultures of both primary undifferentiated cell lines as well as organoid cultures. Thus, evidence is given that cell lineages of endodermal, mesodermal, and ectodermal origin arise spontaneously from a single adult undifferentiated cell type. Based on the present findings it is assumed that pancreatic stellate-like cells are a new class of lineage uncommitted pluripotent adult stem cells with a remarkable self-renewal ability and differentiation potency. The data emphasize the versatility of adult stem cells and may lead to a reappraisal of their use for the treatment of inherited disorders or acquired degenerative diseases.

MV-NIS or Investigator's Choice Chemotherapy in Treating Patients With Ovarian, Fallopian, or Peritoneal Cancer

ClinicalTrials.gov

2018-04-27

Fallopian Tube Transitional Cell Carcinoma; Malignant Ovarian Clear Cell Tumor; Malignant Ovarian Endometrioid Tumor; Malignant Ovarian Serous Tumor; Ovarian Seromucinous Carcinoma; Ovarian Transitional Cell Carcinoma; Primary Peritoneal Serous Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

PI3 K/Akt/mTOR-mediated translational control regulates proliferation and differentiation of lineage-restricted RoSH stem cell lines

PubMed Central

Que, Jianwen; Lian, Qizhou; El Oakley, Reida M; Lim, Bing; Lim, Sai-Kiang

2007-01-01

Background We have previously derived highly similar lineage-restricted stem cell lines, RoSH and E-RoSH cell lines from mouse embryos and CD9hi SSEA-1- differentiated mouse embryonic stem cells, respectively. These cell lines are not pluripotent and differentiate readily into endothelial cells in vitro and in vivo. Results We investigated the signaling pathway that maintains proliferation of these cells in an undifferentiated state, and demonstrate that PI3 K/Akt/mTOR, but not Raf/MEK/Erk, signaling in these cells was active during proliferation and was downregulated during endothelial differentiation. Inhibition of PI3 K/Akt/mTOR signaling, but not Raf/MEK/Erk, reduced proliferation and induced expression of endothelial specific proteins. During differentiation or inhibition of PI3 K/Akt/mTOR signaling, cyclinD2 transcript abundance in ribosome-enriched RNA but not in total RNA was reduced with a corresponding reduction in protein level. In contrast, transcript abundance of endothelial-specific genes e.g. Kdr, Tek and Pdgfrα in ribosome-enriched RNA fraction was not reduced and their protein levels were increased. Together these observations suggested that translational control mediated by PI3K/Akt/mTOR signaling was critical in regulating proliferation and endothelial differentiation of lineage-restricted RoSH-like stem cell lines. Conclusion This study highlights translation regulation as a critical regulatory mechanism during proliferation and differentiation in stem cells. PMID:17892597

Establishment of feeder-free culture system for human induced pluripotent stem cell on DAS nanocrystalline graphene

NASA Astrophysics Data System (ADS)

Lee, Hyunah; Nam, Donggyu; Choi, Jae-Kyung; Araúzo-Bravo, Marcos J.; Kwon, Soon-Yong; Zaehres, Holm; Lee, Taehee; Park, Chan Young; Kang, Hyun-Wook; Schöler, Hans R.; Kim, Jeong Beom

2016-02-01

The maintenance of undifferentiated human pluripotent stem cells (hPSC) under xeno-free condition requires the use of human feeder cells or extracellular matrix (ECM) coating. However, human-derived sources may cause human pathogen contamination by viral or non-viral agents to the patients. Here we demonstrate feeder-free and xeno-free culture system for hPSC expansion using diffusion assisted synthesis-grown nanocrystalline graphene (DAS-NG), a synthetic non-biological nanomaterial which completely rule out the concern of human pathogen contamination. DAS-NG exhibited advanced biocompatibilities including surface nanoroughness, oxygen containing functional groups and hydrophilicity. hPSC cultured on DAS-NG could maintain pluripotency in vitro and in vivo, and especially cell adhesion-related gene expression profile was comparable to those of cultured on feeders, while hPSC cultured without DAS-NG differentiated spontaneously with high expression of somatic cell-enriched adhesion genes. This feeder-free and xeno-free culture method using DAS-NG will facilitate the generation of clinical-grade hPSC.

Similarity in replication timing between polytene and diploid cells is associated with the organization of the Drosophila genome

PubMed Central

Goncharov, Fedor P.; Zhimulev, Igor F.

2018-01-01

Morphologically, polytene chromosomes of Drosophila melanogaster consist of compact “black” bands alternating with less compact “grey” bands and interbands. We developed a comprehensive approach that combines cytological mapping data of FlyBase-annotated genes and novel tools for predicting cytogenetic features of chromosomes on the basis of their protein composition and determined the genomic coordinates for all black bands of polytene chromosome 2R. By a PCNA immunostaining assay, we obtained the replication timetable for all the bands mapped. The results allowed us to compare replication timing between polytene chromosomes in salivary glands and chromosomes from cultured diploid cell lines and to observe a substantial similarity in the global replication patterns at the band resolution level. In both kinds of chromosomes, the intervals between black bands correspond to early replication initiation zones. Black bands are depleted of replication initiation events and are characterized by a gradient of replication timing; therefore, the time of replication completion correlates with the band length. The bands are characterized by low gene density, contain predominantly tissue-specific genes, and are represented by silent chromatin types in various tissues. The borders of black bands correspond well to the borders of topological domains as well as to the borders of the zones showing H3K27me3, SUUR, and LAMIN enrichment. In conclusion, the characteristic pattern of polytene chromosomes reflects partitioning of the Drosophila genome into two global types of domains with contrasting properties. This partitioning is conserved in different tissues and determines replication timing in Drosophila. PMID:29659604

A Sponge-like Structure Involved in the Association and Transport of Maternal Products during Drosophila Oogenesis

PubMed Central

Wilsch-Bräuninger, Michaela; Schwarz, Heinz; Nüsslein-Volhard, Christiane

1997-01-01

Localization of maternally provided RNAs during oogenesis is required for formation of the antero–posterior axis of the Drosophila embryo. Here we describe a subcellular structure in nurse cells and oocytes which may function as an intracellular compartment for assembly and transport of maternal products involved in RNA localization. This structure, which we have termed “sponge body,” consists of ER-like cisternae, embedded in an amorphous electron-dense mass. It lacks a surrounding membrane and is frequently associated with mitochondria. The sponge bodies are not identical to the Golgi complexes. We suggest that the sponge bodies are homologous to the mitochondrial cloud in Xenopus oocytes, a granulo-fibrillar structure that contains RNAs involved in patterning of the embryo. Exuperantia protein, the earliest factor known to be required for the localization of bicoid mRNA to the anterior pole of the Drosophila oocyte, is highly enriched in the sponge bodies but not an essential structural component of these. RNA staining indicates that sponge bodies contain RNA. However, neither the intensity of this staining nor the accumulation of Exuperantia in the sponge bodies is dependent on the amount of bicoid mRNA present in the ovaries. Sponge bodies surround nuage, a possible polar granule precursor. Microtubules and microfilaments are not present in sponge bodies, although transport of the sponge bodies through the cells is implied by their presence in cytoplasmic bridges. We propose that the sponge bodies are structures that, by assembly and transport of included molecules or associated structures, are involved in localization of mRNAs in Drosophila oocytes. PMID:9348297

Metabolic inactivation of the circadian transmitter, pigment dispersing factor (PDF), by neprilysin-like peptidases in Drosophila.

PubMed

Isaac, R Elwyn; Johnson, Erik C; Audsley, Neil; Shirras, Alan D

2007-12-01

Recent studies have firmly established pigment dispersing factor (PDF), a C-terminally amidated octodecapeptide, as a key neurotransmitter regulating rhythmic circadian locomotory behaviours in adult Drosophila melanogaster. The mechanisms by which PDF functions as a circadian peptide transmitter are not fully understood, however; in particular, nothing is known about the role of extracellular peptidases in terminating PDF signalling at synapses. In this study we show that PDF is susceptible to hydrolysis by neprilysin, an endopeptidase that is enriched in synaptic membranes of mammals and insects. Neprilysin cleaves PDF at the internal Ser7-Leu8 peptide bond to generate PDF1-7 and PDF8-18. Neither of these fragments were able to increase intracellular cAMP levels in HEK293 cells cotransfected with the Drosophila PDF receptor cDNA and a firefly luciferase reporter gene, confirming that such cleavage results in PDF inactivation. The Ser7-Leu8 peptide bond was also the principal cleavage site when PDF was incubated with membranes prepared from heads of adult Drosophila. This endopeptidase activity was inhibited by the neprilysin inhibitors phosphoramidon (IC(50,) 0.15 micromol l(-1)) and thiorphan (IC(50,) 1.2 micromol l(-1)). We propose that cleavage by a member of the Drosophila neprilysin family of endopeptidases is the most likely mechanism for inactivating synaptic PDF and that neprilysin might have an important role in regulating PDF signals within circadian neural circuits.

Bevacizumab, Cisplatin, Radiation Therapy, and Fluorouracil in Treating Patients With Stage IIB, Stage III, Stage IVA, or Stage IVB Nasopharyngeal Cancer

ClinicalTrials.gov

2018-01-04

Stage II Nasopharyngeal Keratinizing Squamous Cell Carcinoma AJCC v7; Stage III Nasopharyngeal Keratinizing Squamous Cell Carcinoma AJCC v7; Stage III Nasopharyngeal Undifferentiated Carcinoma AJCC v7; Stage IV Nasopharyngeal Keratinizing Squamous Cell Carcinoma AJCC v7; Stage IV Nasopharyngeal Undifferentiated Carcinoma AJCC v7

rst Transcriptional Activity Influences kirre mRNA Concentration in the Drosophila Pupal Retina during the Final Steps of Ommatidial Patterning

PubMed Central

Machado, Maiaro Cabral Rosa; Octacilio-Silva, Shirlei; Costa, Mara Silvia A.; Ramos, Ricardo Guelerman P.

2011-01-01

Background Drosophila retinal architecture is laid down between 24–48 hours after puparium formation, when some of the still uncommitted interommatidial cells (IOCs) are recruited to become secondary and tertiary pigment cells while the remaining ones undergo apoptosis. This choice between survival and death requires the product of the roughest (rst) gene, an immunoglobulin superfamily transmembrane glycoprotein involved in a wide range of developmental processes. Both temporal misexpression of Rst and truncation of the protein intracytoplasmic domain, lead to severe defects in which IOCs either remain mostly undifferentiated and die late and erratically or, instead, differentiate into extra pigment cells. Intriguingly, mutants not expressing wild type protein often have normal or very mild rough eyes. Methodology/Principal Findings By using quantitative real time PCR to examine rst transcriptional dynamics in the pupal retina, both in wild type and mutant alleles we showed that tightly regulated temporal changes in rst transcriptional rate underlie its proper function during the final steps of eye patterning. Furthermore we demonstrated that the unexpected wild type eye phenotype of mutants with low or no rst expression correlates with an upregulation in the mRNA levels of the rst paralogue kin-of-irre (kirre), which seems able to substitute for rst function in this process, similarly to their role in myoblast fusion. This compensatory upregulation of kirre mRNA levels could be directly induced in wild type pupa upon RNAi-mediated silencing of rst, indicating that expression of both genes is also coordinately regulated in physiological conditions. Conclusions/Significance These findings suggest a general mechanism by which rst and kirre expression could be fine tuned to optimize their redundant roles during development and provide a clearer picture of how the specification of survival and apoptotic fates by differential cell adhesion during the final steps of retinal morphogenesis in insects are controlled at the transcriptional level. PMID:21857931

Whole-Genome Analysis Reveals That Active Heat Shock Factor Binding Sites Are Mostly Associated with Non-Heat Shock Genes in Drosophila melanogaster

PubMed Central

Gonsalves, Sarah E.; Moses, Alan M.; Razak, Zak; Robert, Francois; Westwood, J. Timothy

2011-01-01

During heat shock (HS) and other stresses, HS gene transcription in eukaryotes is up-regulated by the transcription factor heat shock factor (HSF). While the identities of the major HS genes have been known for more than 30 years, it has been suspected that HSF binds to numerous other genes and potentially regulates their transcription. In this study, we have used a chromatin immunoprecipitation and microarray (ChIP-chip) approach to identify 434 regions in the Drosophila genome that are bound by HSF. We have also performed a transcript analysis of heat shocked Kc167 cells and third instar larvae and compared them to HSF binding sites. The heat-induced transcription profiles were quite different between cells and larvae and surprisingly only about 10% of the genes associated with HSF binding sites show changed transcription. There were also genes that showed changes in transcript levels that did not appear to correlate with HSF binding sites. Analysis of the locations of the HSF binding sites revealed that 57% were contained within genes with approximately 2/3rds of these sites being in introns. We also found that the insulator protein, BEAF, has enriched binding prior to HS to promoters of genes that are bound by HSF upon HS but that are not transcriptionally induced during HS. When the genes associated with HSF binding sites in promoters were analyzed for gene ontology terms, categories such as stress response and transferase activity were enriched whereas analysis of genes having HSF binding sites in introns identified those categories plus ones related to developmental processes and reproduction. These results suggest that Drosophila HSF may be regulating many genes besides the known HS genes and that some of these genes may be regulated during non-stress conditions. PMID:21264254

Whole-genome analysis reveals that active heat shock factor binding sites are mostly associated with non-heat shock genes in Drosophila melanogaster.

PubMed

Gonsalves, Sarah E; Moses, Alan M; Razak, Zak; Robert, Francois; Westwood, J Timothy

2011-01-14

During heat shock (HS) and other stresses, HS gene transcription in eukaryotes is up-regulated by the transcription factor heat shock factor (HSF). While the identities of the major HS genes have been known for more than 30 years, it has been suspected that HSF binds to numerous other genes and potentially regulates their transcription. In this study, we have used a chromatin immunoprecipitation and microarray (ChIP-chip) approach to identify 434 regions in the Drosophila genome that are bound by HSF. We have also performed a transcript analysis of heat shocked Kc167 cells and third instar larvae and compared them to HSF binding sites. The heat-induced transcription profiles were quite different between cells and larvae and surprisingly only about 10% of the genes associated with HSF binding sites show changed transcription. There were also genes that showed changes in transcript levels that did not appear to correlate with HSF binding sites. Analysis of the locations of the HSF binding sites revealed that 57% were contained within genes with approximately 2/3rds of these sites being in introns. We also found that the insulator protein, BEAF, has enriched binding prior to HS to promoters of genes that are bound by HSF upon HS but that are not transcriptionally induced during HS. When the genes associated with HSF binding sites in promoters were analyzed for gene ontology terms, categories such as stress response and transferase activity were enriched whereas analysis of genes having HSF binding sites in introns identified those categories plus ones related to developmental processes and reproduction. These results suggest that Drosophila HSF may be regulating many genes besides the known HS genes and that some of these genes may be regulated during non-stress conditions.

Rhabdoid and Undifferentiated Phenotype in Renal Cell Carcinoma: Analysis of 32 Cases Indicating a Distinctive Common Pathway of Dedifferentiation Frequently Associated With SWI/SNF Complex Deficiency.

PubMed

Agaimy, Abbas; Cheng, Liang; Egevad, Lars; Feyerabend, Bernd; Hes, Ondřej; Keck, Bastian; Pizzolitto, Stefano; Sioletic, Stefano; Wullich, Bernd; Hartmann, Arndt

2017-02-01

Undifferentiated (anaplastic) and rhabdoid cell features are increasingly recognized as adverse prognostic findings in renal cell carcinoma (RCC), but their molecular pathogenesis has not been studied sufficiently. Recent studies identified alterations in the Switch Sucrose nonfermentable (SWI/SNF) chromatin remodeling complex as molecular mechanisms underlying dedifferentiation and rhabdoid features in carcinomas of different organs. We herein have analyzed 32 undifferentiated RCCs having in common an undifferentiated (anaplastic) phenotype, prominent rhabdoid features, or both, irrespective of the presence or absence of conventional RCC component. Cases were stained with 6 SWI/SNF pathway members (SMARCB1, SMARCA2, SMARCA4, ARID1A, SMARCC1, and SMARCC2) in addition to conventional RCC markers. Patients were 20 males and 12 females aged 32 to 85 years (mean, 59). A total of 22/27 patients with known stage presented with ≥pT3. A differentiated component varying from microscopic to major component was detected in 20/32 cases (16 clear cell and 2 cases each chromophobe and papillary RCC). The undifferentiated component varied from rhabdoid dyscohesive cells to large epithelioid to small monotonous anaplastic cells. Variable loss of at least 1 SWI/SNF complex subunit was noted in the undifferentiated/rhabdoid component of 21/32 cases (65%) compared with intact or reduced expression in the differentiated component. A total of 15/17 patients (88%) with follow-up died of metastatic disease (mostly within 1 y). Only 2 patients were disease free at last follow-up (1 and 6 y). No difference in survival, age distribution, or sex was observed between the SWI/SNF-deficient and the SWI/SNF-intact group. This is the first study exploring the role of SWI/SNF deficiency as a potential mechanism underlying undifferentiated and rhabdoid phenotype in RCC. Our results highlight the association between the aggressive rhabdoid phenotype and the SWI/SNF complex deficiency, consistent with studies on similar neoplasms in other organs. Thorough sampling of such tumors that are usually huge and locally advanced is necessary for recognizing the clone of origin and hence for proper subtyping and also for differentiating them from undifferentiated urothelial carcinoma.

Deregulation of the CEACAM expression pattern causes undifferentiated cell growth in human lung adenocarcinoma cells.

PubMed

Singer, Bernhard B; Scheffrahn, Inka; Kammerer, Robert; Suttorp, Norbert; Ergun, Suleyman; Slevogt, Hortense

2010-01-18

CEACAM1, CEA/CEACAM5, and CEACAM6 are cell adhesion molecules (CAMs) of the carcinoembryonic antigen (CEA) family that have been shown to be deregulated in lung cancer and in up to 50% of all human cancers. However, little is known about the functional impact of these molecules on undifferentiated cell growth and tumor progression. Here we demonstrate that cell surface expression of CEACAM1 on confluent A549 human lung adenocarcinoma cells plays a critical role in differentiated, contact-inhibited cell growth. Interestingly, CEACAM1-L, but not CEACAM1-S, negatively regulates proliferation via its ITIM domain, while in proliferating cells no CEACAM expression is detectable. Furthermore, we show for the first time that CEACAM6 acts as an inducer of cellular proliferation in A549 cells, likely by interfering with the contact-inhibiting signal triggered by CEACAM1-4L, leading to undifferentiated anchorage-independent cell growth. We also found that A549 cells expressed significant amounts of non-membrane anchored variants of CEACAM5 and CEACAM6, representing a putative source for the increased CEACAM5/6 serum levels frequently found in lung cancer patients. Taken together, our data suggest that post-confluent contact inhibition is established and maintained by CEACAM1-4L, but disturbances of CEACAM1 signalling by CEACAM1-4S and other CEACAMs lead to undifferentiated cell growth and malignant transformation.

DRhoGEF2 and Diaphanous Regulate Contractile Force during Segmental Groove Morphogenesis in the Drosophila Embryo

PubMed Central

Mulinari, Shai; Barmchi, Mojgan Padash

2008-01-01

Morphogenesis of the Drosophila embryo is associated with dynamic rearrangement of the actin cytoskeleton mediated by small GTPases of the Rho family. These GTPases act as molecular switches that are activated by guanine nucleotide exchange factors. One of these factors, DRhoGEF2, plays an important role in the constriction of actin filaments during pole cell formation, blastoderm cellularization, and invagination of the germ layers. Here, we show that DRhoGEF2 is equally important during morphogenesis of segmental grooves, which become apparent as tissue infoldings during mid-embryogenesis. Examination of DRhoGEF2-mutant embryos indicates a role for DRhoGEF2 in the control of cell shape changes during segmental groove morphogenesis. Overexpression of DRhoGEF2 in the ectoderm recruits myosin II to the cell cortex and induces cell contraction. At groove regression, DRhoGEF2 is enriched in cells posterior to the groove that undergo apical constriction, indicating that groove regression is an active process. We further show that the Formin Diaphanous is required for groove formation and strengthens cell junctions in the epidermis. Morphological analysis suggests that Dia regulates cell shape in a way distinct from DRhoGEF2. We propose that DRhoGEF2 acts through Rho1 to regulate acto-myosin constriction but not Diaphanous-mediated F-actin nucleation during segmental groove morphogenesis. PMID:18287521

Undifferentiated Neuroblastoma Cells Are More Sensitive to Photogenerated Oxidative Stress Than Differentiated Cells.

PubMed

Lee, Chu-I; Perng, Jing-Huei; Chen, Huang-Yo; Hong, Yi-Ren; Wang, Jyh-Jye

2015-09-01

Neuroblastoma is one of the most aggressive cancers and has a complex form of differentiation. We hypothesized that advanced cellular differentiation may alter the susceptibility of neuroblastoma to photodynamic treatment (PDT) and confer selective survival advantage. We demonstrated that hematoporphyrin uptake by undifferentiated SH-SY5Y cells was lower than that of differentiated counterparts, yet the former were more susceptible to PDT-induced oxidative stress killing. Photogenerated reactive oxygen species (ROS) in undifferentiated cells efficiently stimulated cell cycle arrest at G2/M phase, mitochondrial apoptotic pathway activation, the sustained phosphorylation of Akt/GSK-3β and ERK. Differentiated cells with more resistance to PDT exhibited a ROS-independent and a prolonged activation of ERK. Both SH-SY5Y cells exposed to PDT exhibited ROS-independent p38 and JNK activation. These results may have important implications for neuroblastoma patients undergoing photodynamic therapy. © 2015 Wiley Periodicals, Inc.

Identification of integrin heterodimers functioning on the surface of undifferentiated porcine primed embryonic stem cells.

PubMed

Kim, Hwa-Young; Baek, Song; Han, Na Rae; Lee, Eunsong; Park, Choon-Keun; Lee, Seung Tae

2018-05-29

In vitro expansion of undifferentiated porcine primed embryonic stem (ES) cells is facilitated by use of non-cellular niches that mimic three-dimensional (3D) microenvironments enclosing an inner cell mass of porcine blastocysts. Therefore, we investigated the integrin heterodimers on the surface of undifferentiated porcine primed ES cells for the purpose of developing a non-cellular niche to support in vitro maintenance of the self-renewal ability of porcine primed ES cells. Immunocytochemistry and a fluorescence immunoassay were performed to assess integrin α and β subunit levels, and attachment and antibody inhibition assays were used to evaluate the function of integrin heterodimers. The integrin α 3 , α 5 , α 6 , α 9 , α V , and β 1 subunits, but not the α 1 , α 2 , α 4 , α 7 , and α 8 subunits, were identified on the surface of undifferentiated porcine primed ES cells. Subsequently, significant increase of their adhesion to fibronectin, tenascin C and vitronectin were observed and functional blocking of integrin heterodimer α 5 β 1 , α 9 β 1 , or α V β 1 showed significantly inhibited adhesion to fibronectin, tenascin C, or vitronectin. No integrin α 6 β 1 heterodimer?mediated adhesion to laminin was detected. These results demonstrate that active α 5 β 1 , α 9 β 1 , and α V β 1 integrin heterodimers are present on the surface of undifferentiated porcine primed ES cells, together with inactive integrin α 3 (presumed) and α 6 subunits. This article is protected by copyright. All rights reserved.

PI(4,5)P2 regulates myoblast fusion through Arp2/3 regulator localization at the fusion site

PubMed Central

Bothe, Ingo; Deng, Su; Baylies, Mary

2014-01-01

Cell-cell fusion is a regulated process that requires merging of the opposing membranes and underlying cytoskeletons. However, the integration between membrane and cytoskeleton signaling during fusion is not known. Using Drosophila, we demonstrate that the membrane phosphoinositide PI(4,5)P2 is a crucial regulator of F-actin dynamics during myoblast fusion. PI(4,5)P2 is locally enriched and colocalizes spatially and temporally with the F-actin focus that defines the fusion site. PI(4,5)P2 enrichment depends on receptor engagement but is upstream or parallel to actin remodeling. Regulators of actin branching via Arp2/3 colocalize with PI(4,5)P2 in vivo and bind PI(4,5)P2 in vitro. Manipulation of PI(4,5)P2 availability leads to impaired fusion, with a reduction in the F-actin focus size and altered focus morphology. Mechanistically, the changes in the actin focus are due to a failure in the enrichment of actin regulators at the fusion site. Moreover, improper localization of these regulators hinders expansion of the fusion interface. Thus, PI(4,5)P2 enrichment at the fusion site encodes spatial and temporal information that regulates fusion progression through the localization of activators of actin polymerization. PMID:24821989

Generation of genome-modified Drosophila cell lines using SwAP.

PubMed

Franz, Alexandra; Brunner, Erich; Basler, Konrad

2017-10-02

The ease of generating genetically modified animals and cell lines has been markedly increased by the recent development of the versatile CRISPR/Cas9 tool. However, while the isolation of isogenic cell populations is usually straightforward for mammalian cell lines, the generation of clonal Drosophila cell lines has remained a longstanding challenge, hampered by the difficulty of getting Drosophila cells to grow at low densities. Here, we describe a highly efficient workflow to generate clonal Cas9-engineered Drosophila cell lines using a combination of cell pools, limiting dilution in conditioned medium and PCR with allele-specific primers, enabling the efficient selection of a clonal cell line with a suitable mutation profile. We validate the protocol by documenting the isolation, selection and verification of eight independently Cas9-edited armadillo mutant Drosophila cell lines. Our method provides a powerful and simple workflow that improves the utility of Drosophila cells for genetic studies with CRISPR/Cas9.

The processing of asparagine-linked oligosaccharides in HT-29 cells is a function of their state of enterocytic differentiation. An accumulation of Man9,8-GlcNAc2-Asn species is indicative of an impaired N-glycan trimming in undifferentiated cells.

PubMed

Ogier-Denis, E; Codogno, P; Chantret, I; Trugnan, G

1988-05-05

Studies on the regulation of the enterocytic differentiation of the human colon cancer cell line HT-29, which is differentiated in the absence (Glc-) but not in the presence of glucose (Glc+), have recently shown that the post-translational processing of sucrase-isomaltase and particularly its glycosylation vary as a function of cell differentiation (Trugnan G., Rousset, M., Chantret, I., Barbat, A., and Zweibaum, A. (1987) J. Cell Biol. 104, 1199-1205). Other studies indicate that in undifferentiated HT-29 Glc+ cells there is an accumulation of UDP-N-acetylhexosamine, which is involved in the glycosylation process (Wice, B. M., Trugnan, G., Pinto, M., Rousset, M., Chevalier, G., Dussaulx, E., Lacroix, B., and Zweibaum, A. (1985) J. Biol. Chem. 260, 139-146). The purpose of the present work is to investigate whether an overall alteration of protein glycosylation is associated with the inability of HT-29 cells to differentiate. At least three alterations are detected: (i) after a 10-min pulse, the incorporation of D-[2-3H]mannose in undifferentiated cells is severely reduced, compared to differentiated cells. (ii) After a 24-h period of labeling with D-[2-3H]mannose, undifferentiated cells accumulate more than 60% of the radioactivity in the high mannose glycopeptides, whereas differentiated HT-29 Glc- cells accumulate only 38%. (iii) The analysis of the high mannose oligosaccharides transferred "en bloc" from the lipid precursor shows that Man9,8-GlcNAc2 species accumulate in undifferentiated cells, whereas no such accumulation can be detected in differentiated cells. This glycosylation pattern is consistent with an impairment of the trimming of high mannose into complex glycans. It is concluded that N-glycan processing is correlated with the state of enterocytic differentiation of HT-29 cells.

Different regulation of aryl hydrocarbon receptor-regulated genes in response to dioxin in undifferentiated and neuronally differentiated human neuroblastoma SH-SY5Y cells.

PubMed

Imran, Saima; Ferretti, Patrizia; Vrzal, Radim

2015-01-01

Some environmental pollutants derived from industrial processes have been suggested to be responsible for neurological impairment in children, especially in heavily polluted areas. Since these compounds are usually activators of aryl hydrocarbon receptor (AhR), it would be important to better understand the molecular pathways downstream of AhR leading to neural deficits. To this purpose, appropriate in vitro human neural model is much needed. Here we have investigated whether undifferentiated and neuronally differentiated human neuroblastoma cells, SH-SY5Y cells, can provide a suitable model for monitoring AhR activity induced by environmental pollutants, focusing on 2,3,7,8-tetrachlordibenzo-p-dioxin (TCDD), a known activator of AhR. Further characterization of differentiated SH-SY5Y showed an increase in AhRR (aryl hydrocarbon receptor repressor), no change in ARNT1 (AhR nuclear translocator 1), and a decrease in ARNT2 expression with differentiation; in contrast, AhR was undetectable in both undifferentiated and differentiated cells. Nonetheless, treatment of parental as well as differentiated SH-SY5Y cells with TCDD resulted in the induction of AhR-regulated genes, CYP1A1 and CYP1B1; AhRR expression was also affected, but to a much smaller extent. These results indicate that undifferentiated SH-SY5Y are less sensitive to TCDD than neuronally differentiated ones, suggesting a higher resistance of the undifferentiated tumor cells to toxic insults. They also suggest that TCDD in these cells may not act via direct activation of AhR that is undetectable in SH-SY5Y as well as in differentiated neurons. Hence, these cells do not provide an appropriate model for studying ligand-mediated activation of AhR.

Olaparib or Cediranib Maleate and Olaparib Compared With Standard Platinum-Based Chemotherapy in Treating Patients With Recurrent Platinum-Sensitive Ovarian, Fallopian Tube, or Primary Peritoneal Cancer

ClinicalTrials.gov

2018-06-11

BRCA Rearrangement; Deleterious BRCA1 Gene Mutation; Deleterious BRCA2 Gene Mutation; Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Transitional Cell Carcinoma; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Tumor; Ovarian Seromucinous Carcinoma; Ovarian Serous Tumor; Ovarian Transitional Cell Carcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Aberrant epigenome in iPSC-derived dopaminergic neurons from Parkinson's disease patients.

PubMed

Fernández-Santiago, Rubén; Carballo-Carbajal, Iria; Castellano, Giancarlo; Torrent, Roger; Richaud, Yvonne; Sánchez-Danés, Adriana; Vilarrasa-Blasi, Roser; Sánchez-Pla, Alex; Mosquera, José Luis; Soriano, Jordi; López-Barneo, José; Canals, Josep M; Alberch, Jordi; Raya, Ángel; Vila, Miquel; Consiglio, Antonella; Martín-Subero, José I; Ezquerra, Mario; Tolosa, Eduardo

2015-12-01

The epigenomic landscape of Parkinson's disease (PD) remains unknown. We performed a genomewide DNA methylation and a transcriptome studies in induced pluripotent stem cell (iPSC)-derived dopaminergic neurons (DAn) generated by cell reprogramming of somatic skin cells from patients with monogenic LRRK2-associated PD (L2PD) or sporadic PD (sPD), and healthy subjects. We observed extensive DNA methylation changes in PD DAn, and of RNA expression, which were common in L2PD and sPD. No significant methylation differences were present in parental skin cells, undifferentiated iPSCs nor iPSC-derived neural cultures not-enriched-in-DAn. These findings suggest the presence of molecular defects in PD somatic cells which manifest only upon differentiation into the DAn cells targeted in PD. The methylation profile from PD DAn, but not from controls, resembled that of neural cultures not-enriched-in-DAn indicating a failure to fully acquire the epigenetic identity own to healthy DAn in PD. The PD-associated hypermethylation was prominent in gene regulatory regions such as enhancers and was related to the RNA and/or protein downregulation of a network of transcription factors relevant to PD (FOXA1, NR3C1, HNF4A, and FOSL2). Using a patient-specific iPSC-based DAn model, our study provides the first evidence that epigenetic deregulation is associated with monogenic and sporadic PD. © 2015 The Authors. Published under the terms of the CC BY 4.0 license.

[Undifferentiated blastic cell crisis of chronic myelogenous leukemia with myeloblastic tumor in the skin].

PubMed

Kawakami, K; Kiyosaki, M; Amaya, H; Nakamaki, T; Hino, K; Tomoyasu, S

2000-04-01

A 54-year-old female, who had been treated for 4 years in the chronic phase of chronic myelogenous leukemia (CML) was admitted for management of a CML blastic crisis. Blast cells showed strong positive expression of CD7 and HLA-DR, and weakly expressed CD2, CD5 and CD10, as well. The cells were peroxidase negative in peripheral blood and bone marrow. An undifferentiated blastic crisis was diagnosed and she was treated with Interferon-alpha and VP(vincristine 2 mg/week; prednisolone 30 mg/day). A 5-7 mm in diameter tumor in the skin of the anterior right chest appeared one week after VP therapy. The tumor consisted of blasts which were CD13, CD33 and peroxidase positive, unlike the peripheral undifferentiated blasts. This is a rare case of mixed blast crisis with an increase in undifferentiated blasts in peripheral blood and bone marrow, and myeloblastic tumor formation in the skin.

Targeting the Gdnf Gene in peritubular myoid cells disrupts undifferentiated spermatogonial cell development

PubMed Central

Chen, Liang-Yu; Willis, William D.; Eddy, Edward M.

2016-01-01

Spermatogonial stem cells (SSCs) are a subpopulation of undifferentiated spermatogonia located in a niche at the base of the seminiferous epithelium delimited by Sertoli cells and peritubular myoid (PM) cells. SSCs self-renew or differentiate into spermatogonia that proliferate to give rise to spermatocytes and maintain spermatogenesis. Glial cell line-derived neurotrophic factor (GDNF) is essential for this process. Sertoli cells produce GDNF and other growth factors and are commonly thought to be responsible for regulating SSC development, but limited attention has been paid to the role of PM cells in this process. A conditional knockout (cKO) of the androgen receptor gene in PM cells resulted in male infertility. We found that testosterone (T) induces GDNF expression in mouse PM cells in vitro and neonatal spermatogonia (including SSCs) co-cultured with T-treated PM cells were able to colonize testes of germ cell-depleted mice after transplantation. This strongly suggested that T-regulated production of GDNF by PM cells is required for spermatogonial development, but PM cells might produce other factors in vitro that are responsible. In this study, we tested the hypothesis that production of GDNF by PM cells is essential for spermatogonial development by generating mice with a cKO of the Gdnf gene in PM cells. The cKO males sired up to two litters but became infertile due to collapse of spermatogenesis and loss of undifferentiated spermatogonia. These studies show for the first time, to our knowledge, that the production of GDNF by PM cells is essential for undifferentiated spermatogonial cell development in vivo. PMID:26831079

Ultrastructural study of the semicircular canal cells of the frog Rana esculenta.

PubMed

Oudar, O; Ferrary, E; Feldmann, G

1988-03-01

The ultrastructure of the nonsensory cells (dark cells, transitional cells, and undifferentiated cells) of the frog semicircular canal was studied by using transmission electron microscopy in an attempt to correlate the structure with the functions of these epithelial cells. All the nonsensory cells were linked by tight junctions and desmosomes; this suggested that there is little paracellular ionic transport from perilymph to endolymph. In the dark cell epithelium, the apical intercellular spaces were dilated; in the basal part, numerous basolateral plasma membrane infoldings, containing mitochondria, delimited electron-lucent spaces. The undifferentiated cells and the transitional cells were devoid of any basal membrane infolding. Surrounding the semicircular canal, very flattened and interdigitated mesothelial cells constituted a thin multilayer tissue which limited the perilymphatic space. The morphological aspect of the dark cells suggests that they may play a role in the secretion and/or in the reabsorption of endolymph, which bathes the apical pole of these cells. The undifferentiated and transitional cells can play a role in the maintenance of the endolymphatic ionic composition because of their apical tight junctions and desmosomes.

Global Patterns of Tissue-Specific Alternative Polyadenylation in Drosophila

PubMed Central

Smibert, Peter; Miura, Pedro; Westholm, Jakub O.; Shenker, Sol; May, Gemma; Duff, Michael O.; Zhang, Dayu; Eads, Brian D.; Carlson, Joe; Brown, James B.; Eisman, Robert C.; Andrews, Justen; Kaufman, Thomas; Cherbas, Peter; Celniker, Susan E.; Graveley, Brenton R.; Lai, Eric C.

2012-01-01

SUMMARY We analyzed the usage and consequences of alternative cleavage and polyadenylation (APA) in Drosophila melanogaster by using >1 billion reads of stranded mRNA-seq across a variety of dissected tissues. Beyond demonstrating that a majority of fly transcripts are subject to APA, we observed broad trends for 3′ untranslated region (UTR) shortening in the testis and lengthening in the central nervous system (CNS); the latter included hundreds of unannotated extensions ranging up to 18 kb. Extensive northern analyses validated the accumulation of full-length neural extended transcripts, and in situ hybridization indicated their spatial restriction to the CNS. Genes encoding RNA binding proteins (RBPs) and transcription factors were preferentially subject to 3′ UTR extensions. Motif analysis indicated enrichment of miRNA and RBP sites in the neural extensions, and their termini were enriched in canonical cis elements that promote cleavage and polyadenylation. Altogether, we reveal broad tissue-specific patterns of APA in Drosophila and transcripts with unprecedented 3′ UTR length in the nervous system. PMID:22685694

Ferritin accumulation under iron scarcity in Drosophila iron cells.

PubMed

Mehta, A; Deshpande, A; Bettedi, L; Missirlis, F

2009-10-01

Ferritins are highly stable, multi-subunit protein complexes with iron-binding capacities that reach 4500 iron atoms per ferritin molecule. The strict dependence of cellular physiology on an adequate supply of iron cofactors has likely been a key driving force in the evolution of ferritins as iron storage molecules. The insect intestine has long been known to contain cells that are responsive to dietary iron levels and a specialized group of "iron cells" that always accumulate iron-loaded ferritin, even when no supplementary iron is added to the diet. Here, we further characterize ferritin localization in Drosophila melanogaster larvae raised under iron-enriched and iron-depleted conditions. High dietary iron intake results in ferritin accumulation in the anterior midgut, but also in garland (wreath) cells and in pericardial cells, which together filter the circulating hemolymph. Ferritin is also abundant in the brain, where levels remain unaltered following dietary iron chelation, a treatment that depletes ferritin from the aforementioned tissues. We attribute the stability of ferritin levels in the brain to the function of the blood-brain barrier that may shield this organ from systemic iron fluctuations. Most intriguingly, our dietary manipulations demonstrably iron-depleted the iron cells without a concomitant reduction in their production of ferritin. Therefore, insect iron cells may constitute an exception from the evolutionary norm with respect to iron-dependent ferritin regulation. It will be of interest to decipher both the physiological purpose served and the mechanism employed to untie ferritin regulation from cellular iron levels in this cell type.

Hesr1 and Hesr3 are essential to generate undifferentiated quiescent satellite cells and to maintain satellite cell numbers

PubMed Central

Fukada, So-ichiro; Yamaguchi, Masahiko; Kokubo, Hiroki; Ogawa, Ryo; Uezumi, Akiyoshi; Yoneda, Tomohiro; Matev, Miroslav M.; Motohashi, Norio; Ito, Takahito; Zolkiewska, Anna; Johnson, Randy L.; Saga, Yumiko; Miyagoe-Suzuki, Yuko; Tsujikawa, Kazutake; Takeda, Shin’ichi; Yamamoto, Hiroshi

2011-01-01

Satellite cells, which are skeletal muscle stem cells, divide to provide new myonuclei to growing muscle fibers during postnatal development, and then are maintained in an undifferentiated quiescent state in adult skeletal muscle. This state is considered to be essential for the maintenance of satellite cells, but their molecular regulation is unknown. We show that Hesr1 (Hey1) and Hesr3 (Heyl) (which are known Notch target genes) are expressed simultaneously in skeletal muscle only in satellite cells. In Hesr1 and Hesr3 single-knockout mice, no obvious abnormalities of satellite cells or muscle regenerative potentials are observed. However, the generation of undifferentiated quiescent satellite cells is impaired during postnatal development in Hesr1/3 double-knockout mice. As a result, myogenic (MyoD and myogenin) and proliferative (Ki67) proteins are expressed in adult satellite cells. Consistent with the in vivo results, Hesr1/3-null myoblasts generate very few Pax7+ MyoD– undifferentiated cells in vitro. Furthermore, the satellite cell number gradually decreases in Hesr1/3 double-knockout mice even after it has stabilized in control mice, and an age-dependent regeneration defect is observed. In vivo results suggest that premature differentiation, but not cell death, is the reason for the reduced number of satellite cells in Hesr1/3 double-knockout mice. These results indicate that Hesr1 and Hesr3 are essential for the generation of adult satellite cells and for the maintenance of skeletal muscle homeostasis. PMID:21989910

In situ label-free quantification of human pluripotent stem cells with electrochemical potential.

PubMed

Yea, Cheol-Heon; Jeong, Ho-Chang; Moon, Sung-Hwan; Lee, Mi-Ok; Kim, Kyeong-Jun; Choi, Jeong-Woo; Cha, Hyuk-Jin

2016-01-01

Conventional methods for quantification of undifferentiated pluripotent stem cells such as fluorescence-activated cell sorting and real-time PCR analysis have technical limitations in terms of their sensitivity and recyclability. Herein, we designed a real-time in situ label-free monitoring system on the basis of a specific electrochemical signature of human pluripotent stem cells in vitro. The intensity of the signal of hPSCs highly corresponded to the cell number and remained consistent in a mixed population with differentiated cells. The electrical charge used for monitoring did not markedly affect the proliferation rate or molecular characteristics of differentiated human aortic smooth muscle cells. After YM155 treatment to ablate undifferentiated hPSCs, their specific signal was significantly reduced. This suggests that detection of the specific electrochemical signature of hPSCs would be a valid approach to monitor potential contamination of undifferentiated hPSCs, which can assess the risk of teratoma formation efficiently and economically. Copyright © 2015 Elsevier Ltd. All rights reserved.

The expression of the class 1 glucose transporter isoforms in human embryonic stem cells, and the potential use of GLUT2 as a marker for pancreatic progenitor enrichment.

PubMed

Segev, Hana; Fishman, Betina; Schulman, Rita; Itskovitz-Eldor, Joseph

2012-07-01

Even before the first appearance of the developing pancreas, glucose is the major substrate in the growing embryo. The transport of glucose across cell membranes is facilitated by a family of membranal glucose transporters (GLUT). We analyzed changes in expression of class 1 glucose transporters (GLUT1-4) during human embryonic stem cell (hESC) and human induced pluripotent stem cell (hiPSC) differentiation, from undifferentiated cells to 28-day-old embryoid bodies (EBs). We also examined the potential use of GLUT2 as a marker for differentiating pancreatic progenitor cells. Using quantitative real time polymerase chain reaction (qPCR), western blot, and immunofluorescence, we observed enhanced expression of GLUT1 and GLUT2 during differentiation, but only minor change in GLUT3 expression. GLUT4 expression was found to be very low both at the RNA and in the protein levels. Expression of the early pancreatic transcription factor, pancreatic duodenal homeobox gene 1 (PDX1), correlated with GLUT2 expression, suggesting the potential use of GLUT2 as a surface marker for tracking pancreatic precursor cells. After sorting EBs according to their membranal GLUT2 expression, GLUT2 and PDX1 expression were found elevated, as was expression of other endodermal markers such as PAX4, NGN3, CXCR4, and SOX17. This simple method may be used to differentiate embryonic stem cells and to isolate from them, using GLUT2 as a surface marker, an enriched pancreatic progenitor cell population in order to achieve insulin-producing cells. The sorted GLUT2 cells may potentially be used in the future as insulin-producing cells for beta cell therapies.

Acute erythroblastic leukemia presenting as acute undifferentiated leukemia: a report of two cases with ultrastructural features.

PubMed

Reiffers, J; Bernard, P; Larrue, J; Dachary, D; David, B; Boisseau, M; Broustet, A

1985-01-01

This report describes two elderly patients with acute leukemia in which blast cells were undifferentiated with conventional light microscopy (L.M.) and cytochemistry. Blast cells were identified as belonging to the erythroblastic line by their ultrastructural features: glycogen deposits, lipidic vacuoles, cytoplasmic ferritin molecules and rhopheocytotic invagination. Moreover, blast cells were surrounding a central macrophage. Thus, these two patients had acute erythroblastic leukemia which differs from erythroleukemia (M6 of FAB classification) in which blast cells present myeloblastic characteristics.

Cediranib Maleate and Olaparib or Standard Chemotherapy in Treating Patients With Recurrent Platinum-Resistant or -Refractory Ovarian, Fallopian Tube, or Primary Peritoneal Cancer

ClinicalTrials.gov

2018-06-15

Deleterious BRCA1 Gene Mutation; Deleterious BRCA2 Gene Mutation; Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Adenocarcinoma; Fallopian Tube Serous Adenocarcinoma; Fallopian Tube Transitional Cell Carcinoma; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Seromucinous Carcinoma; Ovarian Serous Adenocarcinoma; Ovarian Transitional Cell Carcinoma; Primary Peritoneal Serous Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Elesclomol Sodium and Paclitaxel in Treating Patients With Recurrent or Persistent Ovarian Epithelial Cancer, Fallopian Tube Cancer, or Primary Peritoneal Cancer

ClinicalTrials.gov

2017-05-02

Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Adenocarcinoma; Fallopian Tube Mucinous Adenocarcinoma; Fallopian Tube Serous Adenocarcinoma; Fallopian Tube Transitional Cell Carcinoma; Ovarian Brenner Tumor; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Adenocarcinoma; Ovarian Seromucinous Carcinoma; Ovarian Serous Adenocarcinoma; Ovarian Transitional Cell Tumor; Primary Peritoneal Serous Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Trisomy 4 in a case of acute undifferentiated myeloblastic leukemia with hand-mirror cells.

PubMed

Kao, Y S; McCormick, C; Vial, R

1990-04-01

A case of acute undifferentiated myelocytic leukemic with trisomy 4 is described. The patient is a 61-year-old woman who developed leukemia 4 1/2 years after receiving radiation therapy for uterine carcinoma. Many leukemic cells exhibited hand-mirror configuration after the bone marrow aspirate was left at room temperature overnight. The relationship between trisomy 4 and hand-mirror cells in acute myelocytic leukemia is unknown.

Undifferentiated carcinoma of the esophagus: a clinicopathological study of 16 cases☆

PubMed Central

Singhi, Aatur D.; Seethala, Raja R.; Nason, Katie; Foxwell, Tyler J.; Roche, Robyn L.; McGrath, Kevin M.; Levy, Ryan M.; Luketich, James D.; Davison, Jon M.

2015-01-01

Summary Undifferentiated carcinoma of the esophagus is a rare histologic variant of esophageal carcinoma. Using criteria based on studies of undifferentiated carcinomas arising at other sites, we have collected 16 cases of resected esophageal undifferentiated carcinomas. Patients ranged in age from 39 to 84 years (mean, 65.5 years) and were predominantly male (94%). The tumors were characterized by an expansile growth pattern of neoplastic cells organized in solid sheets and without significant glandular, squamous, or neuroendocrine differentiation. The neoplastic cells had a syncytial-like appearance, little intervening stroma, and patchy tumor necrosis. In a subset of cases, the tumor cells adopted a sarcomatoid (n = 2), rhabdoid (n = 1), or minor component (<5%) of glandular morphology (n = 3). In 1 case, reactive osteoclast-like giant cells were found interspersed among the neoplastic cells. Lymphovascular invasion, perineural invasion, and lymph node metastases were identified in 88%, 56%, and 81% of cases, respectively. In 12 (75%) specimens, the background esophageal mucosa was notable for Barrett esophagus. Consistent with the epithelial nature of these neoplasms, cytokeratin positivity was identified in all cases. In addition, SALL4 expression was present in 8 (67%) of 12 cases. Follow-up information was available for 15 (94%) of 16 patients, all of whom were deceased. Survival after surgery ranged from 1 to 50 months (mean, 11.9 months). Before death, 67% patients had documented locoregional recurrence and/or distant organ metastases. In summary, esophageal undifferentiated carcinomas are aggressive neoplasms and associated with a high incidence of recurrence and/or metastases and a dismal prognosis. PMID:25582499

Genomic Signatures of Speciation in Sympatric and Allopatric Hawaiian Picture-Winged Drosophila

PubMed Central

Kang, Lin; Settlage, Robert; McMahon, Wyatt; Michalak, Katarzyna; Tae, Hongseok; Garner, Harold R.; Stacy, Elizabeth A.; Price, Donald K.; Michalak, Pawel

2016-01-01

The Hawaiian archipelago provides a natural arena for understanding adaptive radiation and speciation. The Hawaiian Drosophila are one of the most diverse endemic groups in Hawaiì with up to 1,000 species. We sequenced and analyzed entire genomes of recently diverged species of Hawaiian picture-winged Drosophila, Drosophila silvestris and Drosophila heteroneura from Hawaiì Island, in comparison with Drosophila planitibia, their sister species from Maui, a neighboring island where a common ancestor of all three had likely occurred. Genome-wide single nucleotide polymorphism patterns suggest the more recent origin of D. silvestris and D. heteroneura, as well as a pervasive influence of positive selection on divergence of the three species, with the signatures of positive selection more prominent in sympatry than allopatry. Positively selected genes were significantly enriched for functional terms related to sensory detection and mating, suggesting that sexual selection played an important role in speciation of these species. In particular, sequence variation in Olfactory receptor and Gustatory receptor genes seems to play a major role in adaptive radiation in Hawaiian pictured-winged Drosophila. PMID:27189993

Effects of granulocyte-macrophage colony-stimulating factor and interleukin 6 on the growth of leukemic blasts in suspension culture.

PubMed

Tsao, C J; Cheng, T Y; Chang, S L; Su, W J; Tseng, J Y

1992-05-01

We examined the stimulatory effects of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin 6 (IL)-6 on the in vitro proliferation of leukemic blast cells from patients with acute leukemia. Bone marrow or peripheral blood leukemic blast cells were obtained from 21 patients, including 14 cases of acute myeloblastic leukemia (AML), four cases of acute lymphoblastic leukemia (ALL), two cases of acute undifferentiated leukemia, and one case of acute mixed-lineage leukemia. The proliferation of leukemic blast cells was evaluated by measuring the incorporation of 3H-thymidine into cells incubated with various concentrations of cytokines for 3 days. GM-CSF stimulated the DNA synthesis (with greater than 2.0 stimulation index) of blast cells in 9 of 14 (64%) AML cases, two cases of acute undifferentiated leukemia and one case of acute mixed-lineage leukemia. Only two cases of AML blasts responded to IL-6 to grow in the short-term suspension cultures. GM-CSF and IL-6 did not display a synergistic effect on the growth of leukemic cells. Moreover, GM-CSF and IL-6 did not stimulate the proliferation of ALL blast cells. Binding study also revealed the specific binding of GM-CSF on the blast cells of acute undifferentiated leukemia and acute mixed-lineage leukemia. Our results indicated that leukemic blast cells of acute undifferentiated leukemia and acute mixed-lineage leukemia possessed functional GM-CSF receptors.

Pembrolizumab, Bevacizumab, and Cyclophosphamide in Treating Patients With Recurrent Ovarian, Fallopian Tube, or Primary Peritoneal Cancer

ClinicalTrials.gov

2018-05-03

Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Adenocarcinoma; Fallopian Tube Mucinous Adenocarcinoma; Fallopian Tube Serous Adenocarcinoma; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Adenocarcinoma; Ovarian Serous Adenocarcinoma; Primary Peritoneal Serous Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Conservation of spermatogonial stem cell marker expression in undifferentiated felid spermatogonia.

PubMed

Vansandt, Lindsey M; Livesay, Janelle L; Dickson, Melissa Joy; Li, Lei; Pukazhenthi, Budhan S; Keefer, Carol L

2016-09-01

Spermatogonial stem cells (SSCs) are distinct in their ability to self-renew, transmit genetic information, and persist throughout the life of an individual. These characteristics make SSCs a useful tool for addressing diverse challenges such as efficient transgenic production in nonrodent, biomedical animal models, or preservation of the male genome for species in which survival of frozen-thawed sperm is low. A requisite first step to access this technology in felids is the establishment of molecular markers. This study was designed to evaluate, in the domestic cat (Felis catus), the expression both in situ and following enrichment in vitro of six genes (GFRA1, GPR125, ZBTB16, POU5F1, THY1, and UCHL1) that had been previously identified as SSC markers in other species. Antibodies for surface markers glial cell line-derived neurotrophic factor family receptor alpha 1, G protein-coupled receptor 125, and thymus cell antigen 1 could not be validated, whereas Western blot analysis of prepubertal, peripubertal, and adult cat testis confirmed protein expression for the intracellular markers ubiquitin carboxy-terminal hydrolase 1, zinc finger and BTB domain-containing protein 16, and POU domain, class 5, transcription factor 1. Colocalization of the markers by immunohistochemistry revealed that several cells within the subpopulation adjacent to the basement membrane of the seminiferous tubules and identified morphologically as spermatogonia, expressed all three intracellular markers. Studies performed on cheetah (Acinonyx jubatus) and Amur leopard (Panthera pardus orientalis) testis exhibited a conserved expression pattern in protein molecular weights, relative abundance, and localization of positive cells within the testis. The expression of the three intracellular SSC marker proteins in domestic and wild cat testes confirms conservation of these markers in felids. Enrichment of marker transcripts after differential plating was also observed. These markers will facilitate further studies in cell enrichment and IVC of felid SSCs enabling both production of transgenic domestic cats and preservation of the male genome from rare and endangered felids. Copyright © 2016 Elsevier Inc. All rights reserved.

Epigenetic Regulation of Axonal Growth of Drosophila Pacemaker Cells by Histone Acetyltransferase Tip60 Controls Sleep

PubMed Central

Pirooznia, Sheila K.; Chiu, Kellie; Chan, May T.; Zimmerman, John E.; Elefant, Felice

2012-01-01

Tip60 is a histone acetyltransferase (HAT) enzyme that epigenetically regulates genes enriched for neuronal functions through interaction with the amyloid precursor protein (APP) intracellular domain. However, whether Tip60-mediated epigenetic dysregulation affects specific neuronal processes in vivo and contributes to neurodegeneration remains unclear. Here, we show that Tip60 HAT activity mediates axonal growth of the Drosophila pacemaker cells, termed “small ventrolateral neurons” (sLNvs), and their production of the neuropeptide pigment-dispersing factor (PDF) that functions to stabilize Drosophila sleep–wake cycles. Using genetic approaches, we show that loss of Tip60 HAT activity in the presence of the Alzheimer’s disease-associated APP affects PDF expression and causes retraction of the sLNv synaptic arbor required for presynaptic release of PDF. Functional consequence of these effects is evidenced by disruption of the sleep–wake cycle in these flies. Notably, overexpression of Tip60 in conjunction with APP rescues these sleep–wake disturbances by inducing overelaboration of the sLNv synaptic terminals and increasing PDF levels, supporting a neuroprotective role for dTip60 in sLNv growth and function under APP-induced neurodegenerative conditions. Our findings reveal a novel mechanism for Tip60 mediated sleep–wake regulation via control of axonal growth and PDF levels within the sLNv-encompassing neural network and provide insight into epigenetic-based regulation of sleep disturbances observed in neurodegenerative diseases like Alzheimer’s disease. PMID:22982579

Intestinal stem cells in the adult Drosophila midgut

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

Jiang, Huaqi, E-mail: Huaqi.Jiang@UTSouthwestern.edu; Edgar, Bruce A., E-mail: b.edgar@dkfz.de; Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., Seattle, WA 98109

Drosophila has long been an excellent model organism for studying stem cell biology. Notably, studies of Drosophila's germline stem cells have been instrumental in developing the stem cell niche concept. The recent discovery of somatic stem cells in adult Drosophila, particularly the intestinal stem cells (ISCs) of the midgut, has established Drosophila as an exciting model to study stem cell-mediated adult tissue homeostasis and regeneration. Here, we review the major signaling pathways that regulate the self-renewal, proliferation and differentiation of Drosophila ISCs, discussing how this regulation maintains midgut homeostasis and mediates regeneration of the intestinal epithelium after injury. -- Highlights:more » Black-Right-Pointing-Pointer The homeostasis and regeneration of adult fly midguts are mediated by ISCs. Black-Right-Pointing-Pointer Damaged enterocytes induce the proliferation of intestinal stem cells (ISC). Black-Right-Pointing-Pointer EGFR and Jak/Stat signalings mediate compensatory ISC proliferation. Black-Right-Pointing-Pointer Notch signaling regulates ISC self-renewal and differentiation.« less

Behavior of Xeno-Transplanted Undifferentiated Human Induced Pluripotent Stem Cells Is Impacted by Microenvironment Without Evidence of Tumors.

PubMed

Martínez-Cerdeño, Veronica; Barrilleaux, Bonnie L; McDonough, Ashley; Ariza, Jeanelle; Yuen, Benjamin T K; Somanath, Priyanka; Le, Catherine T; Steward, Craig; Horton-Sparks, Kayla; Knoepfler, Paul S

2017-10-01

Human pluripotent stem cells (hPSC) have great clinical potential through the use of their differentiated progeny, a population in which there is some concern over risks of tumorigenicity or other unwanted cellular behavior due to residual hPSC. Preclinical studies using human stem cells are most often performed within a xenotransplant context. In this study, we sought to measure how undifferentiated hPSC behave following xenotransplant. We directly transplanted undifferentiated human induced pluripotent stem cells (hIPSC) and human embryonic stem cells (hESC) into the adult mouse brain ventricle and analyzed their fates. No tumors or precancerous lesions were present at more than one year after transplantation. This result differed with the tumorigenic capacity we observed after allotransplantation of mouse ESC into the mouse brain. A substantial population of cellular derivatives of undifferentiated hESC and hIPSC engrafted, survived, and migrated within the mouse brain parenchyma. Within brain structures, transplanted cell distribution followed a very specific pattern, suggesting the existence of distinct microenvironments that offer different degrees of permissibility for engraftment. Most of the transplanted hESC and hIPSC that developed into brain cells were NeuN+ neuronal cells, and no astrocytes were detected. Substantial cell and nuclear fusion occurred between host and transplanted cells, a phenomenon influenced by microenvironment. Overall, hIPSC appear to be largely functionally equivalent to hESC in vivo. Altogether, these data bring new insights into the behavior of stem cells without prior differentiation following xenotransplantation into the adult brain.

Putative synaptic genes defined from a Drosophila whole body developmental transcriptome by a machine learning approach.

PubMed

Pazos Obregón, Flavio; Papalardo, Cecilia; Castro, Sebastián; Guerberoff, Gustavo; Cantera, Rafael

2015-09-15

Assembly and function of neuronal synapses require the coordinated expression of a yet undetermined set of genes. Although roughly a thousand genes are expected to be important for this function in Drosophila melanogaster, just a few hundreds of them are known so far. In this work we trained three learning algorithms to predict a "synaptic function" for genes of Drosophila using data from a whole-body developmental transcriptome published by others. Using statistical and biological criteria to analyze and combine the predictions, we obtained a gene catalogue that is highly enriched in genes of relevance for Drosophila synapse assembly and function but still not recognized as such. The utility of our approach is that it reduces the number of genes to be tested through hypothesis-driven experimentation.

Pegylated Liposomal Doxorubicin Hydrochloride With Atezolizumab and/or Bevacizumab in Treating Patients With Recurrent Ovarian, Fallopian Tube, or Primary Peritoneal Cancer

ClinicalTrials.gov

2018-06-20

Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Adenocarcinoma; High Grade Fallopian Tube Serous Adenocarcinoma; High Grade Ovarian Serous Adenocarcinoma; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Seromucinous Carcinoma; Primary Peritoneal High Grade Serous Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Motility screen identifies Drosophila IGF-II mRNA-binding protein--zipcode-binding protein acting in oogenesis and synaptogenesis.

PubMed

Boylan, Kristin L M; Mische, Sarah; Li, Mingang; Marqués, Guillermo; Morin, Xavier; Chia, William; Hays, Thomas S

2008-02-01

The localization of specific mRNAs can establish local protein gradients that generate and control the development of cellular asymmetries. While all evidence underscores the importance of the cytoskeleton in the transport and localization of RNAs, we have limited knowledge of how these events are regulated. Using a visual screen for motile proteins in a collection of GFP protein trap lines, we identified the Drosophila IGF-II mRNA-binding protein (Imp), an ortholog of Xenopus Vg1 RNA binding protein and chicken zipcode-binding protein. In Drosophila, Imp is part of a large, RNase-sensitive complex that is enriched in two polarized cell types, the developing oocyte and the neuron. Using time-lapse confocal microscopy, we establish that both dynein and kinesin contribute to the transport of GFP-Imp particles, and that regulation of transport in egg chambers appears to differ from that in neurons. In Drosophila, loss-of-function Imp mutations are zygotic lethal, and mutants die late as pharate adults. Imp has a function in Drosophila oogenesis that is not essential, as well as functions that are essential during embryogenesis and later development. Germline clones of Imp mutations do not block maternal mRNA localization or oocyte development, but overexpression of a specific Imp isoform disrupts dorsal/ventral polarity. We report here that loss-of-function Imp mutations, as well as Imp overexpression, can alter synaptic terminal growth. Our data show that Imp is transported to the neuromuscular junction, where it may modulate the translation of mRNA targets. In oocytes, where Imp function is not essential, we implicate a specific Imp domain in the establishment of dorsoventral polarity.

Sialyl-lactotetra, a novel cell surface marker of undifferentiated human pluripotent stem cells.

PubMed

Barone, Angela; Säljö, Karin; Benktander, John; Blomqvist, Maria; Månsson, Jan-Eric; Johansson, Bengt R; Mölne, Johan; Aspegren, Anders; Björquist, Petter; Breimer, Michael E; Teneberg, Susann

2014-07-04

Cell surface glycoconjugates are used as markers for undifferentiated pluripotent stem cells. Here, antibody binding and mass spectrometry characterization of acid glycosphingolipids isolated from a large number (1 × 10(9) cells) of human embryonic stem cell (hESC) lines allowed identification of several novel acid glycosphingolipids, like the gangliosides sialyl-lactotetraosylceramide and sialyl-globotetraosylceramide, and the sulfated glycosphingolipids sulfatide, sulf-lactosylceramide, and sulf-globopentaosylceramide. A high cell surface expression of sialyl-lactotetra on hESC and human induced pluripotent stem cells (hiPSC) was demonstrated by flow cytometry, immunohistochemistry, and electron microscopy, whereas sulfated glycosphingolipids were only found in intracellular compartments. Immunohistochemistry showed distinct cell surface anti-sialyl-lactotetra staining on all seven hESC lines and three hiPSC lines analyzed, whereas no staining of hESC-derived hepatocyte-like or cardiomyocyte-like cells was obtained. Upon differentiation of hiPSC into hepatocyte-like cells, the sialyl-lactotetra epitope was rapidly down-regulated and not detectable after 14 days. These findings identify sialyl-lactotetra as a promising marker of undifferentiated human pluripotent stem cells. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

A genetic platform to model sarcomagenesis from primary adult mesenchymal stem cells

PubMed Central

Guarnerio, Jlenia; Riccardi, Luisa; Taulli, Riccardo; Maeda, Takahiro; Wang, Guocan; Hobbs, Robin M.; Song, Min Sup; Sportoletti, Paolo; Bernardi, Rosa; Bronson, Roderick T.; Castillo-Martin, Mireia; Cordon-Cardo, Carlos; Lunardi, Andrea; Pandolfi, Pier Paolo

2015-01-01

The regulatory factors governing adult mesenchymal stem cells (MSCs) physiology and their tumorigenic potential are still largely unknown, which substantially delays the identification of effective therapeutic approaches for the treatment of aggressive and lethal form of MSC-derived mesenchymal tumors, such as undifferentiated sarcomas. Here we have developed a novel platform to screen and quickly identify genes and pathways responsible for adult MSCs transformation, modeled undifferentiated sarcoma in vivo, and, ultimately, tested the efficacy of targeting the identified oncopathways. Importantly, by taking advantage of this new platform, we demonstrate the key role of an aberrant LRF-DLK1-SOX9 pathway in the pathogenesis of undifferentiated sarcoma with important therapeutic implications. PMID:25614485

The composition and organization of Drosophila heterochromatin are heterogeneous and dynamic

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

Swenson, Joel M.; Colmenares, Serafin U.; Strom, Amy R.

Heterochromatin is enriched for specific epigenetic factors including Heterochromatin Protein 1a (HP1a), and is essential for many organismal functions. To elucidate heterochromatin organization and regulation, we purified Drosophila melanogaster HP1a interactors, and performed a genome-wide RNAi screen to identify genes that impact HP1a levels or localization. The majority of the over four hundred putative HP1a interactors and regulators identified were previously unknown. We found that 13 of 16 tested candidates (83%) are required for gene silencing, providing a substantial increase in the number of identified components that impact heterochromatin properties. Surprisingly, image analysis revealed that although some HP1a interactors andmore » regulators are broadly distributed within the heterochromatin domain, most localize to discrete subdomains that display dynamic localization patterns during the cell cycle. We conclude that heterochromatin composition and architecture is more spatially complex and dynamic than previously suggested, and propose that a network of subdomains regulates diverse heterochromatin functions.« less

The composition and organization of Drosophila heterochromatin are heterogeneous and dynamic

DOE PAGES

Swenson, Joel M.; Colmenares, Serafin U.; Strom, Amy R.; ...

2016-08-11

Heterochromatin is enriched for specific epigenetic factors including Heterochromatin Protein 1a (HP1a), and is essential for many organismal functions. To elucidate heterochromatin organization and regulation, we purified Drosophila melanogaster HP1a interactors, and performed a genome-wide RNAi screen to identify genes that impact HP1a levels or localization. The majority of the over four hundred putative HP1a interactors and regulators identified were previously unknown. We found that 13 of 16 tested candidates (83%) are required for gene silencing, providing a substantial increase in the number of identified components that impact heterochromatin properties. Surprisingly, image analysis revealed that although some HP1a interactors andmore » regulators are broadly distributed within the heterochromatin domain, most localize to discrete subdomains that display dynamic localization patterns during the cell cycle. We conclude that heterochromatin composition and architecture is more spatially complex and dynamic than previously suggested, and propose that a network of subdomains regulates diverse heterochromatin functions.« less

Myxococcus CsgA, Drosophila Sniffer, and human HSD10 are cardiolipin phospholipases

PubMed Central

Boynton, Tye O'Hara; Shimkets, Lawrence Joseph

2015-01-01

Myxococcus xanthus development requires CsgA, a member of the short-chain alcohol dehydrogenase (SCAD) family of proteins. We show that CsgA and SocA, a protein that can replace CsgA function in vivo, oxidize the 2′-OH glycerol moiety on cardiolipin and phosphatidylglycerol to produce diacylglycerol (DAG), dihydroxyacetone, and orthophosphate. A lipid extract enriched in DAGs from wild-type cells initiates development and lipid body production in a csgA mutant to bypass the mutational block. This novel phospholipase C-like reaction is widespread. SCADs that prevent neurodegenerative disorders, such as Drosophila Sniffer and human HSD10, oxidize cardiolipin with similar kinetic parameters. HSD10 exhibits a strong preference for cardiolipin with oxidized fatty acids. This activity is inhibited in the presence of the amyloid β peptide. Three HSD10 variants associated with neurodegenerative disorders are inactive with cardiolipin. We suggest that HSD10 protects humans from reactive oxygen species by removing damaged cardiolipin before it induces apoptosis. PMID:26338420

Enhanced expression of extracellular calcium sensing receptor in monocyte-differentiated versus undifferentiated HL-60 cells: potential role in regulation of a nonselective cation channel

NASA Technical Reports Server (NTRS)

Yamaguchi, T.; Ye, C.; Chattopadhyay, N.; Sanders, J. L.; Vassilev, P. M.; Brown, E. M.; O'Malley, B. W. (Principal Investigator)

2000-01-01

Human promyelocytic leukemia cells (HL-60) have been used widely as a model for studying the differentiation of hematopoietic progenitor cells in vitro. After treatment with phorbol-12-myristate-13-acetate (PMA) or 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], HL-60 cells differentiate into cells with the phenotype of monocytes/macrophages. We previously showed that peripheral blood monocytes and the murine J774 monocytic cell line express the CaR, and myeloid progenitors in the bone marrow and myeloid cells in peripheral blood other than monocytes express lower levels of the CaR. Therefore, we investigated whether undifferentiated HL-60 cells express a functional G protein-coupled, extracellular calcium (Ca(2+)(o))-sensing receptor (CaR) and if the expression of the CaR increases as these cells differentiate along the monocytic lineage. The use of reverse transcription-polymerase chain reaction (RT-PCR) with CaR-specific primers, followed by sequencing of the amplified products, identified an authentic CaR transcript in undifferentiated HL-60 cells. Both immunocytochemistry and Western blot analysis using a CaR-specific antiserum detected low levels of CaR protein expression in undifferentiated HL-60 cells. The levels of CaR protein increased considerably following treatment of the cells with PMA (50 nM) or 1,25(OH)(2)D(3) (100 nM) for 5 days. Northern analysis using a CaR-specific riboprobe identified CaR transcripts in undifferentiated HL-60 cells, but CaR mRNA levels did not change appreciably after treatment with either agent, suggesting that upregulation of CaR protein occurs at a translational level. PMA-treated HL-60 cells expressed a nonselective cation channel (NCC), and the calcimimetic CaR activator, NPS R-467, but not its less active stereoisomer, NPS S-467, as well as the polycationic CaR agonist, neomycin, activated this NCC, demonstrating that the CaR expressed in these cells is functionally active. Therefore, HL-60 cells exhibit an increase in CaR protein expression, occurring at a translational level during their differentiation into cells with a monocyte/macrophage phenotype in response to treatment with PMA or 1, 25(OH)(2)D(3), which is functionally linked to activation of a nonselective cation channel.

Metamorphosis of the Drosophila visceral musculature and its role in intestinal morphogenesis and stem cell formation.

PubMed

Aghajanian, Patrick; Takashima, Shigeo; Paul, Manash; Younossi-Hartenstein, Amelia; Hartenstein, Volker

2016-12-01

The visceral musculature of the Drosophila intestine plays important roles in digestion as well as development. Detailed studies investigating the embryonic development of the visceral muscle exist; comparatively little is known about postembryonic development and metamorphosis of this tissue. In this study we have combined the use of specific markers with electron microscopy to follow the formation of the adult visceral musculature and its involvement in gut development during metamorphosis. Unlike the adult somatic musculature, which is derived from a pool of undifferentiated myoblasts, the visceral musculature of the adult is a direct descendant of the larval fibers, as shown by activating a lineage tracing construct in the larval muscle and obtaining labeled visceral fibers in the adult. However, visceral muscles undergo a phase of remodeling that coincides with the metamorphosis of the intestinal epithelium. During the first day following puparium formation, both circular and longitudinal syncytial fibers dedifferentiate, losing their myofibrils and extracellular matrix, and dissociating into mononuclear cells ("secondary myoblasts"). Towards the end of the second day, this process is reversed, and between 48 and 72h after puparium formation, a structurally fully differentiated adult muscle layer has formed. We could not obtain evidence that cells apart from the dedifferentiated larval visceral muscle contributed to the adult muscle, nor does it appear that the number of adult fibers (or nuclei per fiber) is increased over that of the larva by proliferation. In contrast to the musculature, the intestinal epithelium is completely renewed during metamorphosis. The adult midgut epithelium rapidly expands over the larval layer during the first few hours after puparium formation; in case of the hindgut, replacement takes longer, and proceeds by the gradual caudad extension of a proliferating growth zone, the hindgut proliferation zone (HPZ). The subsequent elongation of the hindgut and midgut, as well as the establishment of a population of intestinal stem cells active in the adult midgut and hindgut, requires the presence of the visceral muscle layer, based on the finding that ablation of this layer causes a severe disruption of both processes. Copyright © 2016 Elsevier Inc. All rights reserved.

EZH2 is a mediator of EWS/FLI1 driven tumor growth and metastasis blocking endothelial and neuro-ectodermal differentiation

PubMed Central

Richter, Günther H. S.; Plehm, Stephanie; Fasan, Annette; Rössler, Sabine; Unland, Rebekka; Bennani-Baiti, Idriss M.; Hotfilder, Marc; Löwel, Diana; von Luettichau, Irene; Mossbrugger, Ilona; Quintanilla-Martinez, Leticia; Kovar, Heinrich; Staege, Martin S.; Müller-Tidow, Carsten; Burdach, Stefan

2009-01-01

Ewing tumors (ET) are highly malignant, localized in bone or soft tissue, and are molecularly defined by ews/ets translocations. DNA microarray analysis revealed a relationship of ET to both endothelium and fetal neural crest. We identified expression of histone methyltransferase enhancer of Zeste, Drosophila, Homolog 2 (EZH2) to be increased in ET. Suppressive activity of EZH2 maintains stemness in normal and malignant cells. Here, we found EWS/FLI1 bound to the EZH2 promoter in vivo, and induced EZH2 expression in ET and mesenchymal stem cells. Down-regulation of EZH2 by RNA interference in ET suppressed oncogenic transformation by inhibiting clonogenicity in vitro. Similarly, tumor development and metastasis was suppressed in immunodeficient Rag2−/−γC−/− mice. EZH2-mediated gene silencing was shown to be dependent on histone deacetylase (HDAC) activity. Subsequent microarray analysis of EZH2 knock down, HDAC-inhibitor treatment and confirmation in independent assays revealed an undifferentiated phenotype maintained by EZH2 in ET. EZH2 regulated stemness genes such as nerve growth factor receptor (NGFR), as well as genes involved in neuroectodermal and endothelial differentiation (EMP1, EPHB2, GFAP, and GAP43). These data suggest that EZH2 might have a central role in ET pathology by shaping the oncogenicity and stem cell phenotype of this tumor. PMID:19289832

Cellular Location and Expression of Na+, K+-ATPase α Subunits Affect the Anti-Proliferative Activity of Oleandrin

PubMed Central

Yang, Peiying; Cartwright, Carrie; Efuet, Ekem; Hamilton, Stanley R.; Wistuba, Ignacio Ivan; Menter, David; Addington, Crandell; Shureiqi, Imad; Newman, Robert A.

2015-01-01

The purpose of this study was to investigate whether intracellular distribution of Na+, K+-ATPase α3 subunit, a receptor for cardiac glycosides including oleandrin, is differentially altered in cancer versus normal cells and whether this altered distribution can be therapeutically targeted to inhibit cancer cell survival. The cellular distribution of Na+, K+-ATPase α3 isoform was investigated in paired normal and cancerous mucosa biopsy samples from patients with lung and colorectal cancers by immunohistochemical staining. The effects of oleandrin on α3 subunit intracellular distribution, cell death, proliferation, and EKR phosphorylation were examined in differentiated and undifferentiated human colon cancer CaCO-2 cells. While Na+, K+-ATPase α3 isoform was predominantly located near the cytoplasmic membrane in normal human colon and lung epithelia, the expression of this subunit in their paired cancer epithelia was shifted to a peri-nuclear position in both a qualitative and quantitative manner. Similarly, distribution of α3 isoform was also shifted from a cytoplasmic membrane location in differentiated human colon cancer CaCO-2 cells to a peri-nuclear position in undifferentiated CaCO-2 cells. Intriguingly, oleandrin exerted threefold stronger anti-proliferative activity in undifferentiated CaCO-2 cells (IC50, 8.25 nM) than in differentiated CaCO-2 cells (IC50, >25 nM). Oleandrin (10 to 20 nM) caused an autophagic cell death and altered ERK phosphorylation in undifferentiated but not in differentiated CaCO-2 cells. These data demonstrate that the intracellular location of Na+, K+-ATPase α3 isoform is altered in human cancer versus normal cells. These changes in α3 cellular location and abundance may indicate a potential target of opportunity for cancer therapy. PMID:23073998

Genomic Signatures of Speciation in Sympatric and Allopatric Hawaiian Picture-Winged Drosophila.

PubMed

Kang, Lin; Settlage, Robert; McMahon, Wyatt; Michalak, Katarzyna; Tae, Hongseok; Garner, Harold R; Stacy, Elizabeth A; Price, Donald K; Michalak, Pawel

2016-05-30

The Hawaiian archipelago provides a natural arena for understanding adaptive radiation and speciation. The Hawaiian Drosophila are one of the most diverse endemic groups in Hawaiì with up to 1,000 species. We sequenced and analyzed entire genomes of recently diverged species of Hawaiian picture-winged Drosophila, Drosophila silvestris and Drosophila heteroneura from Hawaiì Island, in comparison with Drosophila planitibia, their sister species from Maui, a neighboring island where a common ancestor of all three had likely occurred. Genome-wide single nucleotide polymorphism patterns suggest the more recent origin of D. silvestris and D. heteroneura, as well as a pervasive influence of positive selection on divergence of the three species, with the signatures of positive selection more prominent in sympatry than allopatry. Positively selected genes were significantly enriched for functional terms related to sensory detection and mating, suggesting that sexual selection played an important role in speciation of these species. In particular, sequence variation in Olfactory receptor and Gustatory receptor genes seems to play a major role in adaptive radiation in Hawaiian pictured-winged Drosophila. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Evolution of Drosophila ribosomal protein gene core promoters.

PubMed

Ma, Xiaotu; Zhang, Kangyu; Li, Xiaoman

2009-03-01

The coordinated expression of ribosomal protein genes (RPGs) has been well documented in many species. Previous analyses of RPG promoters focus only on Fungi and mammals. Recognizing this gap and using a comparative genomics approach, we utilize a motif-finding algorithm that incorporates cross-species conservation to identify several significant motifs in Drosophila RPG promoters. As a result, significant differences of the enriched motifs in RPG promoter are found among Drosophila, Fungi, and mammals, demonstrating the evolutionary dynamics of the ribosomal gene regulatory network. We also report a motif present in similar numbers of RPGs among Drosophila species which does not appear to be conserved at the individual RPG gene level. A module-wise stabilizing selection theory is proposed to explain this observation. Overall, our results provide significant insight into the fast-evolving nature of transcriptional regulation in the RPG module.

Evolution of Drosophila ribosomal protein gene core promoters

PubMed Central

Ma, Xiaotu; Zhang, Kangyu; Li, Xiaoman

2011-01-01

The coordinated expression of ribosomal protein genes (RPGs) has been well documented in many species. Previous analyses of RPG promoters focus only on Fungi and mammals. Recognizing this gap and using a comparative genomics approach, we utilize a motif-finding algorithm that incorporates cross-species conservation to identify several significant motifs in Drosophila RPG promoters. As a result, significant differences of the enriched motifs in RPG promoter are found among Drosophila, Fungi, and mammals, demonstrating the evolutionary dynamics of the ribosomal gene regulatory network. We also report a motif present in similar numbers of RPGs among Drosophila species which does not appear to be conserved at the individual RPG gene level. A module-wise stabilizing selection theory is proposed to explain this observation. Overall, our results provide significant insight into the fast-evolving nature of transcriptional regulation in the RPG module. PMID:19059316

SP600125 has a remarkable anticancer potential against undifferentiated thyroid cancer through selective action on ROCK and p53 pathways.

PubMed

Grassi, Elisa Stellaria; Vezzoli, Valeria; Negri, Irene; Lábadi, Árpád; Fugazzola, Laura; Vitale, Giovanni; Persani, Luca

2015-11-03

Thyroid cancer is the most common endocrine malignancy with increasing incidence worldwide.The majority of thyroid cancer cases are well differentiated with favorable outcome. However, undifferentiated thyroid cancers are one of the most lethal human malignancies because of their invasiveness, metastatization and refractoriness even to the most recently developed therapies.In this study we show for the first time a significant hyperactivation of ROCK/HDAC6 pathway in thyroid cancer tissues, and its negative correlation with p53 DNA binding ability.We demonstrate that a small compound, SP600125 (SP), is able to induce cell death selectively in undifferentiated thyroid cancer cell lines by specifically acting on the pathogenic pathways of cancer development. In detail, SP acts on the ROCK/HDAC6 pathway involved in dedifferentiation and invasiveness of undifferentiated human cancers, by restoring its physiological activity level. As main consequence, cancer cell migration is inhibited and, at the same time, cell death is induced through the mitotic catastrophe. Moreover, SP exerts a preferential action on the mutant p53 by increasing its DNA binding ability. In TP53-mutant cells that survive mitotic catastrophe this process results in p21 induction and eventually lead to premature senescence. In conclusion, SP has been proved to be able to simultaneously block cell replication and migration, the two main processes involved in cancer development and dissemination, making it an ideal candidate for developing new drugs against anaplastic thyroid cancer.

High-Density ZnO Nanowires as a Reversible Myogenic-Differentiation Switch.

PubMed

Errico, Vito; Arrabito, Giuseppe; Fornetti, Ersilia; Fuoco, Claudia; Testa, Stefano; Saggio, Giovanni; Rufini, Stefano; Cannata, Stefano; Desideri, Alessandro; Falconi, Christian; Gargioli, Cesare

2018-04-25

Mesoangioblasts are outstanding candidates for stem-cell therapy and are already being explored in clinical trials. However, a crucial challenge in regenerative medicine is the limited availability of undifferentiated myogenic progenitor cells because growth is typically accompanied by differentiation. Here reversible myogenic-differentiation switching during proliferation is achieved by functionalizing the glass substrate with high-density ZnO nanowires (NWs). Specifically, mesoangioblasts grown on ZnO NWs present a spherical viable undifferentiated cell state without lamellopodia formation during the entire observation time (8 days). Consistently, the myosin heavy chain, typically expressed in skeletal muscle tissue and differentiated myogenic progenitors, is completely absent. Remarkably, NWs do not induce any damage while they reversibly block differentiation, so that the differentiation capabilities are completely recovered upon cell removal from the NW-functionalized substrate and replating on standard culture glass. This is the first evidence of a reversible myogenic-differentiation switch that does not affect the viability. These results can be the first step toward for the in vitro growth of a large number of undifferentiated stem/progenitor cells and therefore can represent a breakthrough for cell-based therapy and tissue engineering.

Reversible structural alterations of undifferentiated and differentiated human neuroblastoma cells induced by phorbol ester.

PubMed Central

Tint, I S; Bonder, E M; Feder, H H; Reboulleau, C P; Vasiliev, J M; Gelfand, I M

1992-01-01

Morphological alterations in the structure of undifferentiated and morphologically differentiated human neuroblastoma cells induced by phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C, were examined by video microscopy and immunomorphology. In undifferentiated cells, PMA induced the formation of motile actin-rich lamellas and of stable cylindrical processes rich in microtubules. Formation of stable processes resulted either from the collapse of lamellas or the movement of the cell body away from the base of a process. In differentiated cells, PMA induced the rapid extension of small lamellas and subsequent formation of short-lived elongated processes from the lateral edges of neurites. Additionally, growth cones exhibited enhanced modulation in shape after PMA treatment. These reversible reorganizations were similar to the actinoplast-tubuloplast transformations exhibited by PMA-treated fibroblasts. We suggest that actinoplast-tubuloplast reorganizations play essential roles in morphogenesis where stable cytoplasmic extensions are induced by external stimuli. In particular, PMA-induced reorganizations of neural cells in culture may be a model for morphological modulations that occur in nerve tissue. Images PMID:1518842

Anaplastic Thyroid Carcinoma: A ceRNA Analysis Pointed to a Crosstalk between SOX2, TP53, and microRNA Biogenesis

PubMed Central

Carina, Valeria; Tomasello, Laura; Pitrone, Maria; Baiamonte, Concetta; Amato, Marco Calogero

2015-01-01

It has been suggested that cancer stem cells (CSC) may play a central role in oncogenesis, especially in undifferentiated tumours. Anaplastic thyroid carcinoma (ATC) has characteristics suggestive of a tumour enriched in CSC. Previous studies suggested that the stem cell factor SOX2 has a preeminent hierarchical role in determining the characteristics of stem cells in SW1736 ATC cell line. In detail, silencing SOX2 in SW1736 is able to suppress the expression of the stem markers analysed, strongly sensitizing the line to treatment with chemotherapeutic agents. Therefore, in order to further investigate the role of SOX2 in ATC, a competing endogenous RNA (ceRNA) analysis was conducted in order to isolate new functional partners of SOX2. Among the interactors, of particular interest are genes involved in the biogenesis of miRNAs (DICER1, RNASEN, and EIF2C2), in the control cell cycle (TP53, CCND1), and in mitochondrial activity (COX8A). The data suggest that stemness, microRNA biogenesis and functions, p53 regulatory network, cyclin D1, and cell cycle control, together with mitochondrial activity, might be coregulated. PMID:25705224

Non-Small Cell Carcinoma of the Lung With Osteoclast-Like Giant Cells.

PubMed

Dahm, Hans Helmut

2017-05-01

Carcinomas of the lung with benign osteoclast-like giant cells are rare. A literature search showed only 8 previously reported examples. These tumors resemble a giant cell tumor of bone. Many of these tumors, which occur in most epithelium-containing organs, are composed of an undifferentiated, sarcomatoid component that contains benign osteoclast-like giant cells and a conventional carcinoma. In some tumors the epithelial origin may be revealed by immunohistochemistry only; others lack any evidence of an epithelial component. A 59-year-old man had an inoperable tumor in the upper lobe of the left lung. The tumor did not respond to radiation therapy, and chemotherapy resulted in minimal relief of symptoms. Light microscopy of biopsy samples showed benign osteoclast-like giant cells distributed irregularly between proliferations of undifferentiated medium-sized tumor cells. Approximately one third of the undifferentiated tumor cells were cytokeratin AE1/AE3-positive, and a minor alveolar clear cell component of the tumor was cytokeratin 7-positive. The osteoclast-like giant cells were strongly CD68-positive. The clinical and histologic findings supported the diagnosis of a non-small cell carcinoma of the lung with benign osteoclast-like giant cells. The differential diagnosis is composed of giant cell carcinoma, carcinosarcoma, and mesenchymal tumors of the lung.

Primary undifferentiated small round cell sarcoma of the deep abdominal wall with a novel variant of t(10;19) CIC-DUX4 gene fusion.

PubMed

Tsukamoto, Yoshitane; Futani, Hiroyuki; Yoshiya, Shinichi; Watanabe, Takahiro; Kihara, Takako; Matsuo, Shohei; Hirota, Seiichi

2017-10-01

We experienced a 38-year-old Japanese male with t(10;19) CIC-DUX4 -positive undifferentiated small round cell sarcoma in the deep abdominal wall. Three months before his first visit to our hospital, he noticed a mass in his right abdominal wall. Computed tomography on admission revealed a solid abdominal tumor 70×53mm in size and multiple small tumors in both lungs. The biopsy of the abdominal tumor revealed undifferentiated small round cell sarcoma, suggestive of Ewing sarcoma. Under the clinical diagnosis of Ewing-like sarcoma of the abdominal wall with multiple lung metastases, several cycles of ICE (ifosfamide, carboplatin and etoposide) therapy were performed. After the chemotherapy, the lung metastases disappeared, while the primary lesion rapidly grew. Additional VDC (vincristine, doxorubicin and cyclophosphamide) therapy was carried out without apparent effect. Although the surgical removal of the primary lesion was done, peritoneal dissemination and a huge metastatic liver tumor appeared thereafter. The patient died of disease progression two months after the surgery. The total clinical course was approximately one year, showing that the tumor was extremely aggressive. The tumor cells of the surgical specimen were positive for CD99, WT1, calretinin, INI1, ERG and Fli1 by immunohistochemistry. Fusion gene analyses using the frozen surgical material revealed negativity for EWSR1-Fli1, EWSR1-ERG and t(4;19) CIC-DUX4 fusions, but positivity for t(10;19) CIC-DUX4 fusion. Thus, we made a final pathological diagnosis of t(10;19) CIC-DUX4-positive undifferentiated small round cell sarcoma. To our knowledge, this is the 13th case of t(10;19) CIC-DUX4 undifferentiated small round cell sarcoma with precise clinicopathological information. Especially in our case, two types of t(10;19) CIC-DUX4 fusion transcripts were observed, both of which are in-frame and novel. Copyright © 2017 Elsevier GmbH. All rights reserved.

β2-Microglobulin as a potential factor for the expansion of mesenchymal stem cells

PubMed Central

Zhu, Ying; Su, Yongping; Cheng, Tianmin; Chung, Leland W. K.

2010-01-01

Multipotent mesenchymal stem cells (MSCs) hold great promise in regenerative medicine, but one of the biggest challenges facing for their application is the ex vivo expansion to obtain enough undifferentiated cells. Fetal bovine serum (FBS), which can elicit possible contaminations of prion, virus, zoonosis or immunological reaction against xenogenic serum antigens, still remains essential to the culture formulations. There is an urgent need to identify potential factors for the undifferentiated expansion of MSCs to reduce the use of FBS or eventually replace it. A previously recognized housekeeping gene, β2-microglobulin (β2M), is demonstrated to act as a novel growth factor to stimulate the undifferentiated ex vivo expansion and preserve the pluripotency of adult MSCs from various sources. The use of β2M might have promising implications for future clinical application of MSCs. PMID:19466557

Autophagy in Drosophila melanogaster.

PubMed

McPhee, Christina K; Baehrecke, Eric H

2009-09-01

Macroautophagy (autophagy) is a bulk cytoplasmic degradation process that is conserved from yeast to mammals. Autophagy is an important cellular response to starvation and stress, and plays critical roles in development, cell death, aging, immunity, and cancer. The fruit fly Drosophila melanogaster provides an excellent model system to study autophagy in vivo, in the context of a developing organism. Autophagy (atg) genes and their regulators are conserved in Drosophila, and autophagy is induced in response to nutrient starvation and hormones during development. In this review we provide an overview of how Drosophila research has contributed to our understanding of the role and regulation of autophagy in cell survival, growth, nutrient utilization, and cell death. Recent Drosophila research has also provided important mechanistic information about the role of autophagy in protein aggregation disorders, neurodegeneration, aging, and innate immunity. Differences in the role of autophagy in specific contexts and/or cell types suggest that there may be cell-context-specific regulators of autophagy, and studies in Drosophila are well-suited to yield discoveries about this specificity.

FMR1 Epigenetic Silencing Commonly Occurs in Undifferentiated Fragile X-Affected Embryonic Stem Cells

PubMed Central

Avitzour, Michal; Mor-Shaked, Hagar; Yanovsky-Dagan, Shira; Aharoni, Shira; Altarescu, Gheona; Renbaum, Paul; Eldar-Geva, Talia; Schonberger, Oshrat; Levy-Lahad, Ephrat; Epsztejn-Litman, Silvina; Eiges, Rachel

2014-01-01

Summary Fragile X syndrome (FXS) is the most common heritable form of cognitive impairment. It results from epigenetic silencing of the X-linked FMR1 gene by a CGG expansion in its 5′-untranslated region. Taking advantage of a large set of FXS-affected human embryonic stem cell (HESC) lines and isogenic subclones derived from them, we show that FMR1 hypermethylation commonly occurs in the undifferentiated state (six of nine lines, ranging from 24% to 65%). In addition, we demonstrate that hypermethylation is tightly linked with FMR1 transcriptional inactivation in undifferentiated cells, coincides with loss of H3K4me2 and gain of H3K9me3, and is unrelated to CTCF binding. Taken together, these results demonstrate that FMR1 epigenetic gene silencing takes place in FXS HESCs and clearly highlights the importance of examining multiple cell lines when investigating FXS and most likely other epigenetically regulated diseases. PMID:25418717

FMR1 epigenetic silencing commonly occurs in undifferentiated fragile X-affected embryonic stem cells.

PubMed

Avitzour, Michal; Mor-Shaked, Hagar; Yanovsky-Dagan, Shira; Aharoni, Shira; Altarescu, Gheona; Renbaum, Paul; Eldar-Geva, Talia; Schonberger, Oshrat; Levy-Lahad, Ephrat; Epsztejn-Litman, Silvina; Eiges, Rachel

2014-11-11

Fragile X syndrome (FXS) is the most common heritable form of cognitive impairment. It results from epigenetic silencing of the X-linked FMR1 gene by a CGG expansion in its 5'-untranslated region. Taking advantage of a large set of FXS-affected human embryonic stem cell (HESC) lines and isogenic subclones derived from them, we show that FMR1 hypermethylation commonly occurs in the undifferentiated state (six of nine lines, ranging from 24% to 65%). In addition, we demonstrate that hypermethylation is tightly linked with FMR1 transcriptional inactivation in undifferentiated cells, coincides with loss of H3K4me2 and gain of H3K9me3, and is unrelated to CTCF binding. Taken together, these results demonstrate that FMR1 epigenetic gene silencing takes place in FXS HESCs and clearly highlights the importance of examining multiple cell lines when investigating FXS and most likely other epigenetically regulated diseases.

Long-term maintenance of human induced pluripotent stem cells by automated cell culture system.

PubMed

Konagaya, Shuhei; Ando, Takeshi; Yamauchi, Toshiaki; Suemori, Hirofumi; Iwata, Hiroo

2015-11-17

Pluripotent stem cells, such as embryonic stem cells and induced pluripotent stem (iPS) cells, are regarded as new sources for cell replacement therapy. These cells can unlimitedly expand under undifferentiated conditions and be differentiated into multiple cell types. Automated culture systems enable the large-scale production of cells. In addition to reducing the time and effort of researchers, an automated culture system improves the reproducibility of cell cultures. In the present study, we newly designed a fully automated cell culture system for human iPS maintenance. Using an automated culture system, hiPS cells maintained their undifferentiated state for 60 days. Automatically prepared hiPS cells had a potency of differentiation into three germ layer cells including dopaminergic neurons and pancreatic cells.

Drosophila hematopoiesis under normal conditions and in response to immune stress.

PubMed

Letourneau, Manon; Lapraz, Francois; Sharma, Anurag; Vanzo, Nathalie; Waltzer, Lucas; Crozatier, Michèle

2016-11-01

The emergence of hematopoietic progenitors and their differentiation into various highly specialized blood cell types constitute a finely tuned process. Unveiling the genetic cascades that control blood cell progenitor fate and understanding how they are modulated in response to environmental changes are two major challenges in the field of hematopoiesis. In the last 20 years, many studies have established important functional analogies between blood cell development in vertebrates and in the fruit fly, Drosophila melanogaster. Thereby, Drosophila has emerged as a powerful genetic model for studying mechanisms that control hematopoiesis during normal development or in pathological situations. Moreover, recent advances in Drosophila have highlighted how intricate cell communication networks and microenvironmental cues regulate blood cell homeostasis. They have also revealed the striking plasticity of Drosophila mature blood cells and the presence of different sites of hematopoiesis in the larva. This review provides an overview of Drosophila hematopoiesis during development and summarizes our current knowledge on the molecular processes controlling larval hematopoiesis, both under normal conditions and in response to an immune challenge, such as wasp parasitism. © 2016 Federation of European Biochemical Societies.

BCOR-CCNB3 Fusions Are Frequent in Undifferentiated Sarcomas of Male Children

PubMed Central

Peters, Tricia L.; Kumar, Vijetha; Polikepahad, Sumanth; Lin, Frank Y.; Sarabia, Stephen F.; Liang, Yu; Wang, Wei-Lien; Lazar, Alexander J.; Doddapaneni, Harsha Vardhan; Chao, Hsu; Muzny, Donna M.; Wheeler, David A.; Okcu, M. Fatih; Plon, Sharon E.; Hicks, M. John; López-Terrada, Dolores; Parsons, D. Williams; Roy, Angshumoy

2014-01-01

The BCOR-CCNB3 fusion gene, resulting from a chromosome X paracentric inversion, was recently described in translocation-negative ‘Ewing-like’ sarcomas arising in bone and soft tissue. Genetic subclassification of undifferentiated unclassified sarcomas may potentially offer markers for reproducible diagnosis and substrates for therapy. Using whole transcriptome paired end RNA sequencing (RNA-seq) we unexpectedly identified BCOR-CCNB3 fusion transcripts in an undifferentiated spindle cell sarcoma. RNA-seq results were confirmed through direct RT-PCR of tumor RNA and cloning of the genomic breakpoints from tumor DNA. Five additional undifferentiated sarcomas with BCOR-CCNB3 fusions were identified in a series of 42 pediatric and adult unclassified sarcomas. Genomic breakpoint analysis demonstrated unique breakpoint locations in each case at the DNA level even though the resulting fusion mRNA was identical in all cases. All patients with BCOR-CCNB3 sarcoma were males diagnosed in mid-childhood (7-13 years of age). Tumors were equally distributed between axial and extra-axial locations. Five of the six tumors were soft tissue lesions with either predominant spindle cell morphology or spindle cell areas interspersed with ovoid to round cells. CCNB3 immunohistochemistry showed strong nuclear positivity in 5 tumors prior to oncologic therapy, but was patchy to negative in post-treatment tumor samples. An RT-PCR assay developed to detect the fusion transcript in archival formalin-fixed tissue was positive in all 6 cases, with high sensitivity and specificity in both pre- and post-treated samples. This study adds to recent reports on the clinicopathologic spectrum of BCOR-CCNB3 fusion-positive sarcomas, a newly-emerging entity within the undifferentiated unclassified sarcoma category, and describes a simple RT-PCR assay that in conjunction with CCNB3 immunohistochemistry can be useful in diagnosing these tumors. PMID:25360585

Endometrial and ovarian carcinomas with undifferentiated components: clinically aggressive and frequently underrecognized neoplasms.

PubMed

Tafe, Laura J; Garg, Karuna; Chew, Ivy; Tornos, Carmen; Soslow, Robert A

2010-06-01

Carcinomas of the endometrium and ovary with undifferentiated components are uncommon neoplasms that are likely underdiagnosed. They are important to recognize as they have been shown to be clinically aggressive. We identified 32 carcinomas with undifferentiated components as defined by Silva and co-workers, 26 endometrial and 6 of ovarian origin. The patient age ranged from 21 to 76 years (median 55); 40% of patients were

Clonal yeast biofilms can reap competitive advantages through cell differentiation without being obligatorily multicellular

PubMed Central

Hanghøj, Kristian Ebbesen; Andersen, Kaj Scherz; Boomsma, Jacobus J.

2016-01-01

How differentiation between cell types evolved is a fundamental question in biology, but few studies have explored single-gene phenotypes that mediate first steps towards division of labour with selective advantage for groups of cells. Here, we show that differential expression of the FLO11 gene produces stable fractions of Flo11+ and Flo11− cells in clonal Saccharomyces cerevisiae biofilm colonies on medium with intermediate viscosity. Differentiated Flo11+/− colonies, consisting of adhesive and non-adhesive cells, obtain a fourfold growth advantage over undifferentiated colonies by overgrowing glucose resources before depleting them, rather than depleting them while they grow as undifferentiated Flo11− colonies do. Flo11+/− colonies maintain their structure and differentiated state by switching non-adhesive cells to adhesive cells with predictable probability. Mixtures of Flo11+ and Flo11− cells from mutant strains that are unable to use this epigenetic switch mechanism produced neither integrated colonies nor growth advantages, so the condition-dependent selective advantages of differentiated FLO11 expression can only be reaped by clone-mate cells. Our results show that selection for cell differentiation in clonal eukaryotes can evolve before the establishment of obligate undifferentiated multicellularity, and without necessarily leading to more advanced organizational complexity. PMID:27807261

Spaceflight Transcriptomes: Unique Responses to a Novel Environment

PubMed Central

Paul, Anna-Lisa; Zupanska, Agata K.; Ostrow, Dejerianne T.; Zhang, Yanping; Sun, Yijun; Li, Jian-Liang; Shanker, Savita; Farmerie, William G.; Amalfitano, Claire E.

2012-01-01

Abstract The spaceflight environment presents unique challenges to terrestrial biology, including but not limited to the direct effects of gravity. As we near the end of the Space Shuttle era, there remain fundamental questions about the response and adaptation of plants to orbital spaceflight conditions. We address a key baseline question of whether gene expression changes are induced by the orbital environment, and then we ask whether undifferentiated cells, cells presumably lacking the typical gravity response mechanisms, perceive spaceflight. Arabidopsis seedlings and undifferentiated cultured Arabidopsis cells were launched in April, 2010, as part of the BRIC-16 flight experiment on STS-131. Biologically replicated DNA microarray and averaged RNA digital transcript profiling revealed several hundred genes in seedlings and cell cultures that were significantly affected by launch and spaceflight. The response was moderate in seedlings; only a few genes were induced by more than 7-fold, and the overall intrinsic expression level for most differentially expressed genes was low. In contrast, cell cultures displayed a more dramatic response, with dozens of genes showing this level of differential expression, a list comprised primarily of heat shock–related and stress-related genes. This baseline transcriptome profiling of seedlings and cultured cells confirms the fundamental hypothesis that survival of the spaceflight environment requires adaptive changes that are both governed and displayed by alterations in gene expression. The comparison of intact plants with cultures of undifferentiated cells confirms a second hypothesis: undifferentiated cells can detect spaceflight in the absence of specialized tissue or organized developmental structures known to detect gravity. Key Words: Tissue culture—Microgravity—Low Earth orbit—Space Shuttle—Microarray. Astrobiology 12, 40–56. PMID:22221117

Midgut-enriched receptor protein tyrosine phosphatase PTP52F is required for Drosophila development during larva-pupa transition.

PubMed

Santhanam, Abirami; Liang, Suh-Yuen; Chen, Dong-Yuan; Chen, Guang-Chao; Meng, Tzu-Ching

2013-01-01

To date our understanding of Drosophila receptor protein tyrosine phosphatases (R-PTPs) in the regulation of signal transduction is limited. Of the seven R-PTPs identified in flies, six are involved in the axon guidance that occurs during embryogenesis. However, whether and how R-PTPs may control key steps of Drosophila development is not clear. In this study we investigated the potential role of Drosophila R-PTPs in developmental processes outside the neuronal system and beyond the embryogenesis stage. Through systematic data mining of available microarray databases, we found the mRNA level of PTP52F to be highly enriched in the midgut of flies at the larva-pupa transition. This finding was confirmed by gut tissue staining with a specific antibody. The unique spatiotemporal expression of PTP52F suggests that it is possibly involved in regulating metamorphosis during the transformation from larva to pupa. To test this hypothesis, we employed RNA interference to examine the defects of transgenic flies. We found that ablation of endogenous PTP52F led to high lethality characterized by the pharate adult phenotype, occurring due to post pupal eclosion failure. These results show that PTP52F plays an indispensable role during the larva-pupa transition. We also found that PTP52F could be reclassified as a member of the subtype R3 PTPs instead of as an unclassified R-PTP without a human ortholog, as suggested previously. Together, these findings suggest that Drosophila R-PTPs may control metamorphosis and other biological processes beyond our current knowledge. © 2012 The Authors Journal compilation © 2012 FEBS.

Biological effect of food additive titanium dioxide nanoparticles on intestine: an in vitro study.

PubMed

Song, Zheng-Mei; Chen, Ni; Liu, Jia-Hui; Tang, Huan; Deng, Xiaoyong; Xi, Wen-Song; Han, Kai; Cao, Aoneng; Liu, Yuanfang; Wang, Haifang

2015-10-01

Titanium dioxide nanoparticles (TiO2 NPs) are widely found in food-related consumer products. Understanding the effect of TiO2 NPs on the intestinal barrier and absorption is essential and vital for the safety assessment of orally administrated TiO2 NPs. In this study, the cytotoxicity and translocation of two native TiO2 NPs, and these two TiO2 NPs pretreated with the digestion simulation fluid or bovine serum albumin were investigated in undifferentiated Caco-2 cells, differentiated Caco-2 cells and Caco-2 monolayer. TiO2 NPs with a concentration less than 200 µg ml(-1) did not induce any toxicity in differentiated cells and Caco-2 monolayer after 24 h exposure. However, TiO2 NPs pretreated with digestion simulation fluids at 200 µg ml(-1) inhibited the growth of undifferentiated Caco-2 cells. Undifferentiated Caco-2 cells swallowed native TiO2 NPs easily, but not pretreated NPs, implying the protein coating on NPs impeded the cellular uptake. Compared with undifferentiated cells, differentiated ones possessed much lower uptake ability of these TiO2 NPs. Similarly, the traverse of TiO2 NPs through the Caco-2 monolayer was also negligible. Therefore, we infer the possibility of TiO2 NPs traversing through the intestine of animal or human after oral intake is quite low. This study provides valuable information for the risk assessment of TiO2 NPs in food. Copyright © 2015 John Wiley & Sons, Ltd.

New tools for the analysis of glial cell biology in Drosophila.

PubMed

Awasaki, Takeshi; Lee, Tzumin

2011-09-01

Because of its genetic, molecular, and behavioral tractability, Drosophila has emerged as a powerful model system for studying molecular and cellular mechanisms underlying the development and function of nervous systems. The Drosophila nervous system has fewer neurons and exhibits a lower glia:neuron ratio than is seen in vertebrate nervous systems. Despite the simplicity of the Drosophila nervous system, glial organization in flies is as sophisticated as it is in vertebrates. Furthermore, fly glial cells play vital roles in neural development and behavior. In addition, powerful genetic tools are continuously being created to explore cell function in vivo. In taking advantage of these features, the fly nervous system serves as an excellent model system to study general aspects of glial cell development and function in vivo. In this article, we review and discuss advanced genetic tools that are potentially useful for understanding glial cell biology in Drosophila. Copyright © 2011 Wiley-Liss, Inc.

Bcl-2 proteins and autophagy regulate mitochondrial dynamics during programmed cell death in the Drosophila ovary.

PubMed

Tanner, Elizabeth A; Blute, Todd A; Brachmann, Carrie Baker; McCall, Kimberly

2011-01-01

The Bcl-2 family has been shown to regulate mitochondrial dynamics during cell death in mammals and C. elegans, but evidence for this in Drosophila has been elusive. Here, we investigate the regulation of mitochondrial dynamics during germline cell death in the Drosophila melanogaster ovary. We find that mitochondria undergo a series of events during the progression of cell death, with remodeling, cluster formation and uptake of clusters by somatic follicle cells. These mitochondrial dynamics are dependent on caspases, the Bcl-2 family, the mitochondrial fission and fusion machinery, and the autophagy machinery. Furthermore, Bcl-2 family mutants show a striking defect in cell death in the ovary. These data indicate that a mitochondrial pathway is a major mechanism for activation of cell death in Drosophila oogenesis.

A genomic investigation of ecological differentiation between free-living and Drosophila-associated bacteria.

PubMed

Winans, Nathan J; Walter, Alec; Chouaia, Bessem; Chaston, John M; Douglas, Angela E; Newell, Peter D

2017-09-01

Various bacterial taxa have been identified both in association with animals and in the external environment, but the extent to which related bacteria from the two habitat types are ecologically and evolutionarily distinct is largely unknown. This study investigated the scale and pattern of genetic differentiation between bacteria of the family Acetobacteraceae isolated from the guts of Drosophila fruit flies, plant material and industrial fermentations. Genome-scale analysis of the phylogenetic relationships and predicted functions was conducted on 44 Acetobacteraceae isolates, including newly sequenced genomes from 18 isolates from wild and laboratory Drosophila. Isolates from the external environment and Drosophila could not be assigned to distinct phylogenetic groups, nor are their genomes enriched for any different sets of genes or category of predicted gene functions. In contrast, analysis of bacteria from laboratory Drosophila showed they were genetically distinct in their universal capacity to degrade uric acid (a major nitrogenous waste product of Drosophila) and absence of flagellar motility, while these traits vary among wild Drosophila isolates. Analysis of the competitive fitness of Acetobacter discordant for these traits revealed a significant fitness deficit for bacteria that cannot degrade uric acid in culture with Drosophila. We propose that, for wild populations, frequent cycling of Acetobacter between Drosophila and the external environment prevents genetic differentiation by maintaining selection for traits adaptive in both the gut and external habitats. However, laboratory isolates bear the signs of adaptation to persistent association with the Drosophila host under tightly defined environmental conditions. © 2017 John Wiley & Sons Ltd.

Vaccine Therapy in Treating Patients With Stage IIIC-IV Ovarian Epithelial, Fallopian Tube, or Primary Peritoneal Cavity Cancer Following Surgery and Chemotherapy

ClinicalTrials.gov

2017-10-12

Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Tumor; Fallopian Tube Mucinous Neoplasm; Fallopian Tube Serous Neoplasm; Fallopian Tube Transitional Cell Carcinoma; Ovarian Clear Cell Cystadenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Cystadenocarcinoma; Ovarian Seromucinous Carcinoma; Ovarian Serous Cystadenocarcinoma; Ovarian Transitional Cell Carcinoma; Primary Peritoneal Serous Adenocarcinoma; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Stage IIIC Fallopian Tube Cancer; Stage IIIC Ovarian Cancer; Stage IIIC Primary Peritoneal Cancer; Stage IV Fallopian Tube Cancer; Stage IV Ovarian Cancer; Stage IV Primary Peritoneal Cancer; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Genome-Wide Mapping of Collier In Vivo Binding Sites Highlights Its Hierarchical Position in Different Transcription Regulatory Networks

PubMed Central

Dubois, Laurence; Bataillé, Laetitia; Painset, Anaïs; Le Gras, Stéphanie; Jost, Bernard; Crozatier, Michèle; Vincent, Alain

2015-01-01

Collier, the single Drosophila COE (Collier/EBF/Olf-1) transcription factor, is required in several developmental processes, including head patterning and specification of muscle and neuron identity during embryogenesis. To identify direct Collier (Col) targets in different cell types, we used ChIP-seq to map Col binding sites throughout the genome, at mid-embryogenesis. In vivo Col binding peaks were associated to 415 potential direct target genes. Gene Ontology analysis revealed a strong enrichment in proteins with DNA binding and/or transcription-regulatory properties. Characterization of a selection of candidates, using transgenic CRM-reporter assays, identified direct Col targets in dorso-lateral somatic muscles and specific neuron types in the central nervous system. These data brought new evidence that Col direct control of the expression of the transcription regulators apterous and eyes-absent (eya) is critical to specifying neuronal identities. They also showed that cross-regulation between col and eya in muscle progenitor cells is required for specification of muscle identity, revealing a new parallel between the myogenic regulatory networks operating in Drosophila and vertebrates. Col regulation of eya, both in specific muscle and neuronal lineages, may illustrate one mechanism behind the evolutionary diversification of Col biological roles. PMID:26204530

Genome-wide localization of exosome components to active promoters and chromatin insulators in Drosophila

PubMed Central

Lim, Su Jun; Boyle, Patrick J.; Chinen, Madoka; Dale, Ryan K.; Lei, Elissa P.

2013-01-01

Chromatin insulators are functionally conserved DNA–protein complexes situated throughout the genome that organize independent transcriptional domains. Previous work implicated RNA as an important cofactor in chromatin insulator activity, although the precise mechanisms are not yet understood. Here we identify the exosome, the highly conserved major cellular 3′ to 5′ RNA degradation machinery, as a physical interactor of CP190-dependent chromatin insulator complexes in Drosophila. Genome-wide profiling of exosome by ChIP-seq in two different embryonic cell lines reveals extensive and specific overlap with the CP190, BEAF-32 and CTCF insulator proteins. Colocalization occurs mainly at promoters but also boundary elements such as Mcp, Fab-8, scs and scs′, which overlaps with a promoter. Surprisingly, exosome associates primarily with promoters but not gene bodies of active genes, arguing against simple cotranscriptional recruitment to RNA substrates. Similar to insulator proteins, exosome is also significantly enriched at divergently transcribed promoters. Directed ChIP of exosome in cell lines depleted of insulator proteins shows that CTCF is required specifically for exosome association at Mcp and Fab-8 but not other sites, suggesting that alternate mechanisms must also contribute to exosome chromatin recruitment. Taken together, our results reveal a novel positive relationship between exosome and chromatin insulators throughout the genome. PMID:23358822

Live-Cell Imaging of the Adult Drosophila Ovary Using Confocal Microscopy.

PubMed

Shalaby, Nevine A; Buszczak, Michael

2017-01-01

The Drosophila ovary represents a key in vivo model used to study germline stem cell (GSC) maintenance and stem cell daughter differentiation because these cells and their somatic cell neighbors can be identified at single-cell resolution within their native environment. Here we describe a fluorescent-based technique for the acquisition of 4D datasets of the Drosophila ovariole for periods that can exceed 12 consecutive hours. Live-cell imaging facilitates the investigation of molecular and cellular dynamics that were not previously possible using still images.

Utilization of human amniotic mesenchymal cells as feeder layers to sustain propagation of human embryonic stem cells in the undifferentiated state.

PubMed

Zhang, Kehua; Cai, Zhe; Li, Yang; Shu, Jun; Pan, Lin; Wan, Fang; Li, Hong; Huang, Xiaojie; He, Chun; Liu, Yanqiu; Cui, Xiaohui; Xu, Yang; Gao, Yan; Wu, Liqun; Cao, Shanxia; Li, Lingsong

2011-08-01

Human embryonic stem (ES) cells are usually maintained in the undifferentiated state by culturing on feeder cells layers of mouse embryonic fibroblasts (MEFs). However, MEFs are not suitable to support human ES cells used for clinical purpose because of risk of zoonosis from animal cells. Therefore, human tissue-based feeder layers need to be developed for human ES cells for clinical purpose. Hereof we report that human amniotic mesenchymal cells (hAMCs) could act as feeder cells for human ES cells, because they are easily obtained and relatively exempt from ethical problem. Like MEFs, hAMCs could act as feeder cells for human ES cells to grow well on. The self-renewal rate of human ES cells cultured on hAMCs feeders was higher than that on MEFs and human amniotic epithelial cells determined by measurement of colonial diameters and growth curve as well as cell cycle analysis. Both immunofluorescence staining and immunoblotting showed that human ES cells cultured on hAMCs expressed stem cell markers such as Oct-3/4, Sox2, and NANOG. Verified by embryoid body formation in vitro and teratoma formation in vivo, we found out that after 20 passages of culture, human ES cells grown on hAMCs feeders could still retain the potency of differentiating into three germ layers. Taken together, our data suggested hAMCs may be safe feeder cells to sustain the propagation of human ES cells in undifferentiated state for future therapeutic use.

Prediction of gene expression in embryonic structures of Drosophila melanogaster.

PubMed

Samsonova, Anastasia A; Niranjan, Mahesan; Russell, Steven; Brazma, Alvis

2007-07-01

Understanding how sets of genes are coordinately regulated in space and time to generate the diversity of cell types that characterise complex metazoans is a major challenge in modern biology. The use of high-throughput approaches, such as large-scale in situ hybridisation and genome-wide expression profiling via DNA microarrays, is beginning to provide insights into the complexities of development. However, in many organisms the collection and annotation of comprehensive in situ localisation data is a difficult and time-consuming task. Here, we present a widely applicable computational approach, integrating developmental time-course microarray data with annotated in situ hybridisation studies, that facilitates the de novo prediction of tissue-specific expression for genes that have no in vivo gene expression localisation data available. Using a classification approach, trained with data from microarray and in situ hybridisation studies of gene expression during Drosophila embryonic development, we made a set of predictions on the tissue-specific expression of Drosophila genes that have not been systematically characterised by in situ hybridisation experiments. The reliability of our predictions is confirmed by literature-derived annotations in FlyBase, by overrepresentation of Gene Ontology biological process annotations, and, in a selected set, by detailed gene-specific studies from the literature. Our novel organism-independent method will be of considerable utility in enriching the annotation of gene function and expression in complex multicellular organisms.

Prediction of Gene Expression in Embryonic Structures of Drosophila melanogaster

PubMed Central

Samsonova, Anastasia A; Niranjan, Mahesan; Russell, Steven; Brazma, Alvis

2007-01-01

Understanding how sets of genes are coordinately regulated in space and time to generate the diversity of cell types that characterise complex metazoans is a major challenge in modern biology. The use of high-throughput approaches, such as large-scale in situ hybridisation and genome-wide expression profiling via DNA microarrays, is beginning to provide insights into the complexities of development. However, in many organisms the collection and annotation of comprehensive in situ localisation data is a difficult and time-consuming task. Here, we present a widely applicable computational approach, integrating developmental time-course microarray data with annotated in situ hybridisation studies, that facilitates the de novo prediction of tissue-specific expression for genes that have no in vivo gene expression localisation data available. Using a classification approach, trained with data from microarray and in situ hybridisation studies of gene expression during Drosophila embryonic development, we made a set of predictions on the tissue-specific expression of Drosophila genes that have not been systematically characterised by in situ hybridisation experiments. The reliability of our predictions is confirmed by literature-derived annotations in FlyBase, by overrepresentation of Gene Ontology biological process annotations, and, in a selected set, by detailed gene-specific studies from the literature. Our novel organism-independent method will be of considerable utility in enriching the annotation of gene function and expression in complex multicellular organisms. PMID:17658945

PRMT5 as a druggable target for glioblastoma therapy.

PubMed

Banasavadi-Siddegowda, Yeshavanth Kumar; Welker, Alessandra M; An, Min; Yang, Xiaozhi; Zhou, Wei; Shi, Guqin; Imitola, Jaime; Li, Chenglong; Hsu, Sigmund; Wang, Jiang; Phelps, Mitch; Zhang, Jianying; Beattie, Christine E; Baiocchi, Robert; Kaur, Balveen

2018-05-18

In spite of standard multimodal therapy consisting of surgical resection followed by radiation and concurrent chemotherapy, prognosis for glioblastoma (GBM) patients remains poor. The identification of both differentiated and undifferentiated "stem cell like" populations in the tumor highlights the significance of finding novel targets that affect the heterogeneous tumor cell population. Protein arginine methyltransferase 5 (PRMT5) is one such candidate gene whose nuclear expression correlates with poor survival and has been reported to be required for survival of differentiated GBM cells and self-renewal of undifferentiated GBM cells. In the current study we screened the specificity and efficacy of 4 novel PRMT5 inhibitors in the treatment of GBM. Efficacies of these inhibitors were screened using an in vitro GBM neurosphere model and an in vivo intracranial zebrafish model of glioma. Standard molecular biology methods were employed to investigate changes in cell cycle, growth, and senescence. In vitro and in vivo studies revealed that among the 4 PRMT5 inhibitors, treatment of GBM cells with compound 5 (CMP5) mirrored the effects of PRMT5 knockdown wherein it led to apoptosis of differentiated GBM cells and drove undifferentiated primary patient derived GBM cells into a nonreplicative senescent state. In vivo antitumor efficacy combined with the specificity of CMP5 underscores the importance of developing it for translation.

Ultrastructural demonstration of Cx43 gap junctions in induced pluripotent stem cells from human cord blood.

PubMed

Beckmann, Anja; Schubert, Madline; Hainz, Nadine; Haase, Alexandra; Martin, Ulrich; Tschernig, Thomas; Meier, Carola

2016-11-01

Gap junction proteins are essential for direct intercellular communication but also influence cellular differentiation and migration. The expression of various connexin gap junction proteins has been demonstrated in embryonic stem cells, with Cx43 being the most intensely studied. As Cx43 is the most prominent gap junction protein in the heart, cardiomyocyte-differentiated stem cells have been studied intensely. To date, however, little is known about the expression and the subcellular distribution of Cx43 in undifferentiated stem cells or about the structural arrangement of channels. We, therefore, here investigate expression of Cx43 in undifferentiated human cord-blood-derived induced pluripotent stem cells (hCBiPS2). For this purpose, we carried out quantitative real-time PCR and immunohistochemistry. For analysis of Cx43 ultrastructure and protein assembly, we performed freeze-fracture replica immunogold labeling (FRIL). Cx43 expression was detected at mRNA and protein level in hCBIPS2 cells. For the first time, ultrastructural data are presented on gap junction morphology in induced pluripotent stem (iPS) cells from cord blood: Our FRIL and electron microscopical analysis revealed the occurrence of gap junction plaques in undifferentiated iPS cells. In addition, these gap junctions were shown to contain the gap junction protein Cx43.

The Adult Drosophila Malpighian Tubules Are Maintained by Pluripotent Stem Cells

PubMed Central

Singh, Shree Ram; Liu, Wei; Hou, Steven X.

2007-01-01

Summary All animals must excrete the waste products of metabolism. Excretion is performed by the kidney in vertebrates and by the Malpighian tubules in Drosophila. The mammalian kidney has an inherent ability for recovery and regeneration following ischemic injury. Stem cells and progenitor cells have been proposed to be responsible for repair and regeneration of injured renal tissue. In Drosophila, the Malpighian tubules are thought to be very stable, and no stem cells have been identified. We have identified pluripotent stem cells in the region of lower tubules and ureters of the Malpighian tubules. Using lineage tracing and molecular marker labeling, we demonstrated that several differentiated cells in the Malpighian tubules arise from the stem cells and an autocrine JAK-STAT signaling regulates the stem cells' self-renewal. Identifying adult kidney stem cells in Drosophila may provide important clues for understanding mammalian kidney repair and regeneration during injury. PMID:18371350

Myxococcus CsgA, Drosophila Sniffer, and human HSD10 are cardiolipin phospholipases.

PubMed

Boynton, Tye O'Hara; Shimkets, Lawrence Joseph

2015-09-15

Myxococcus xanthus development requires CsgA, a member of the short-chain alcohol dehydrogenase (SCAD) family of proteins. We show that CsgA and SocA, a protein that can replace CsgA function in vivo, oxidize the 2'-OH glycerol moiety on cardiolipin and phosphatidylglycerol to produce diacylglycerol (DAG), dihydroxyacetone, and orthophosphate. A lipid extract enriched in DAGs from wild-type cells initiates development and lipid body production in a csgA mutant to bypass the mutational block. This novel phospholipase C-like reaction is widespread. SCADs that prevent neurodegenerative disorders, such as Drosophila Sniffer and human HSD10, oxidize cardiolipin with similar kinetic parameters. HSD10 exhibits a strong preference for cardiolipin with oxidized fatty acids. This activity is inhibited in the presence of the amyloid β peptide. Three HSD10 variants associated with neurodegenerative disorders are inactive with cardiolipin. We suggest that HSD10 protects humans from reactive oxygen species by removing damaged cardiolipin before it induces apoptosis. © 2015 Boynton and Shimkets; Published by Cold Spring Harbor Laboratory Press.

Sodium and calcium currents in neuroblastoma x glioma hybrid cells before and after morphological differentiation by dibutyryl cyclic AMP.

PubMed

Bodewei, R; Hering, S; Schubert, B; Wollenberger, A

1985-04-01

Sodium and calcium inward currents (INa and ICa) were measured in neuroblastoma X glioma hybrid cells of clones 108CC5 and 108CC15 by a single suction pipette method for internal perfusion and voltage clamp. Morphologically undifferentiated, exponentially growing cells were compared with cells differentiated by cultivation with 1 mmol/l dibutyryl cyclic AMP. Outward currents were eliminated by perfusing the cells with a K+-free solution. Voltage dependence and ion selectivity as well as steady state inactivation characteristics of INa and ICa resembled those of differentiated mouse neuroblastoma cells, clone N1E-115 (Moolenaar and Spector 1978, 1979). These parameters were identical in undifferentiated and differentiated cells of both clones. After differentiation the average density of the peak sodium and calcium currents was increased two and four-fold, respectively, in both cell lines. Our data indicate that exponentially growing, morphologically undifferentiated 108CC5 and 108CC15 neuroblastoma X glioma hybrid cells possess functional Na+ and Ca2+ channels undistinguishable from those of non-proliferating cells of these clones differentiated morphologically by treatment with dibutyryl cyclic AMP. That Na+ and Ca2+ spikes were not detected by other authors in these cells prior to morphological differentiation by dibutyryl cyclic AMP may be attributed to the fact that at the low resting membrane potential measured the Na+ and Ca2+ channels are inactivated.

Identification of multipotent mesenchymal stromal cells in the reactive stroma of a prostate cancer xenograft by side population analysis

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

Santamaria-Martinez, Albert; Universitat de Barcelona, Barcelona; Barquinero, Jordi

2009-10-15

Cancer stem cells are a distinct cellular population that is believed to be responsible for tumor initiation and maintenance. Recent data suggest that solid tumors also contain another type of stem cells, the mesenchymal stem cells or multipotent mesenchymal stromal cells (MSCs), which contribute to the formation of tumor-associated stroma. The Hoechst 33342 efflux assay has proved useful to identify a rare cellular fraction, named Side Population (SP), enriched in cells with stem-like properties. Using this assay, we identified SP cells in a prostate cancer xenograft containing human prostate cancer cells and mouse stromal cells. The SP isolation, subculture andmore » sequential sorting allowed the generation of single-cell-derived clones of murine origin that were recognized as MSC by their morphology, plastic adherence, proliferative potential, adipogenic and osteogenic differentiation ability and immunophenotype (CD45{sup -}, CD81{sup +} and Sca-1{sup +}). We also demonstrated that SP clonal cells secrete transforming growth factor {beta}1 (TGF-{beta}1) and that their inhibition reduces proliferation and accelerates differentiation. These results reveal the existence of SP cells in the stroma of a cancer xenograft, and provide evidence supporting their MSC nature and the role of TGF-{beta}1 in maintaining their proliferation and undifferentiated status. Our data also reveal the usefulness of the SP assay to identify and isolate MSC cells from carcinomas.« less

Identification of multipotent mesenchymal stromal cells in the reactive stroma of a prostate cancer xenograft by side population analysis.

PubMed

Santamaria-Martínez, Albert; Barquinero, Jordi; Barbosa-Desongles, Anna; Hurtado, Antoni; Pinós, Tomàs; Seoane, Joan; Poupon, Marie-France; Morote, Joan; Reventós, Jaume; Munell, Francina

2009-10-15

Cancer stem cells are a distinct cellular population that is believed to be responsible for tumor initiation and maintenance. Recent data suggest that solid tumors also contain another type of stem cells, the mesenchymal stem cells or multipotent mesenchymal stromal cells (MSCs), which contribute to the formation of tumor-associated stroma. The Hoechst 33342 efflux assay has proved useful to identify a rare cellular fraction, named Side Population (SP), enriched in cells with stem-like properties. Using this assay, we identified SP cells in a prostate cancer xenograft containing human prostate cancer cells and mouse stromal cells. The SP isolation, subculture and sequential sorting allowed the generation of single-cell-derived clones of murine origin that were recognized as MSC by their morphology, plastic adherence, proliferative potential, adipogenic and osteogenic differentiation ability and immunophenotype (CD45(-), CD81(+) and Sca-1(+)). We also demonstrated that SP clonal cells secrete transforming growth factor beta1 (TGF-beta1) and that their inhibition reduces proliferation and accelerates differentiation. These results reveal the existence of SP cells in the stroma of a cancer xenograft, and provide evidence supporting their MSC nature and the role of TGF-beta1 in maintaining their proliferation and undifferentiated status. Our data also reveal the usefulness of the SP assay to identify and isolate MSC cells from carcinomas.

Amplification of the 1731 LTR retrotransposon in Drosophila melanogaster cultured cells: origin of neocopies and impact on the genome.

PubMed

Maisonhaute, Claude; Ogereau, David; Hua-Van, Aurélie; Capy, Pierre

2007-05-15

Transposable elements (TEs), represent a large fraction of the eukaryotic genome. In Drosophila melanogaster, about 20% of the genome corresponds to such middle repetitive DNA dispersed sequences. A fraction of TEs is composed of elements showing a retrovirus-like structure, the LTR-retrotransposons, the first TEs to be described in the Drosophila genome. Interestingly, in D. melanogaster embryonic immortal cell culture genomes the copy number of these LTR-retrotransposons was revealed to be higher than the copy number in the Drosophila genome, presumably as the result of transposition of some copies to new genomic locations [Potter, S.S., Brorein Jr., W.J., Dunsmuir, P., Rubin, G.M., 1979. Transposition of elements of the 412, copia and 297 dispersed repeated gene families in Drosophila. Cell 17, 415-427; Junakovic, N., Di Franco, C., Best-Belpomme, M., Echalier, G., 1988. On the transposition of copia-like nomadic elements in cultured Drosophila cells. Chromosoma 97, 212-218]. This suggests that so many transpositions modified the genome organisation and consequently the expression of targeted genes. To understand what has directed the transposition of TEs in Drosophila cell culture genomes, a search to identify the newly transposed copies was undertaken using 1731, a LTR-retrotransposon. A comparison between 1731 full-length elements found in the fly sequenced genome (y(1); cn(1)bw(1), sp(1) stock) and 1731 full-length elements amplified by PCR in the two cell line was done. The resulting data provide evidence that all 1731 neocopies were derived from a single copy slightly active in the Drosophila genome and subsequently strongly activated in cultured cells; and that this active copy is related to a newly evolved genomic variant (Kalmykova, A.I., et al., 2004. Selective expansion of the newly evolved genomic variants of retrotransposon 1731 in the Drosophila genomes. Mol. Biol. Evol. 21, 2281-2289). Moreover, neocopies are shown to be inserted in different sets of genes in the two cell lines suggesting they might be involved in the biological and physiological differences observed between Kc and S2 cell lines.

Increased centrosome amplification in aged stem cells of the Drosophila midgut

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

Park, Joung-Sun; Pyo, Jung-Hoon; Na, Hyun-Jin

Highlights: • Increased centrosome amplification in ISCs of aged Drosophila midguts. • Increased centrosome amplification in ISCs of oxidative stressed Drosophila midguts. • Increased centrosome amplification in ISCs by overexpression of PVR, EGFR, and AKT. • Supernumerary centrosomes can be responsible for abnormal ISC polyploid cells. • Supernumerary centrosomes can be a useful marker for aging stem cells. - Abstract: Age-related changes in long-lived tissue-resident stem cells may be tightly linked to aging and age-related diseases such as cancer. Centrosomes play key roles in cell proliferation, differentiation and migration. Supernumerary centrosomes are known to be an early event in tumorigenesismore » and senescence. However, the age-related changes of centrosome duplication in tissue-resident stem cells in vivo remain unknown. Here, using anti-γ-tubulin and anti-PH3, we analyzed mitotic intestinal stem cells with supernumerary centrosomes in the adult Drosophila midgut, which may be a versatile model system for stem cell biology. The results showed increased centrosome amplification in intestinal stem cells of aged and oxidatively stressed Drosophila midguts. Increased centrosome amplification was detected by overexpression of PVR, EGFR, and AKT in intestinal stem cells/enteroblasts, known to mimic age-related changes including hyperproliferation of intestinal stem cells and hyperplasia in the midgut. Our data show the first direct evidence for the age-related increase of centrosome amplification in intestinal stem cells and suggest that the Drosophila midgut is an excellent model for studying molecular mechanisms underlying centrosome amplification in aging adult stem cells in vivo.« less

Identification and functional characterization of muscle satellite cells in Drosophila

PubMed Central

Reichert, Heinrich

2017-01-01

Work on genetic model systems such as Drosophila and mouse has shown that the fundamental mechanisms of myogenesis are remarkably similar in vertebrates and invertebrates. Strikingly, however, satellite cells, the adult muscle stem cells that are essential for the regeneration of damaged muscles in vertebrates, have not been reported in invertebrates. In this study, we show that lineal descendants of muscle stem cells are present in adult muscle of Drosophila as small, unfused cells observed at the surface and in close proximity to the mature muscle fibers. Normally quiescent, following muscle fiber injury, we show that these cells express Zfh1 and engage in Notch-Delta-dependent proliferative activity and generate lineal descendant populations, which fuse with the injured muscle fiber. In view of strikingly similar morphological and functional features, we consider these novel cells to be the Drosophila equivalent of vertebrate muscle satellite cells. PMID:29072161

Evaluating the Autonomy of the Drosophila Circadian Clock in Dissociated Neuronal Culture.

PubMed

Sabado, Virginie; Vienne, Ludovic; Nagoshi, Emi

2017-01-01

Circadian behavioral rhythms offer an excellent model to study intricate interactions between the molecular and neuronal mechanisms of behavior. In mammals, pacemaker neurons in the suprachiasmatic nucleus (SCN) generate rhythms cell-autonomously, which are synchronized by the network interactions within the circadian circuit to drive behavioral rhythms. However, whether this principle is universal to circadian systems in animals remains unanswered. Here, we examined the autonomy of the Drosophila circadian clock by monitoring transcriptional and post-transcriptional rhythms of individual clock neurons in dispersed culture with time-lapse microscopy. Expression patterns of the transcriptional reporter show that CLOCK/CYCLE (CLK/CYC)-mediated transcription is constantly active in dissociated clock neurons. In contrast, the expression profile of the post-transcriptional reporter indicates that PERIOD (PER) protein levels fluctuate and ~10% of cells display rhythms in PER levels with periods in the circadian range. Nevertheless, PER and TIM are enriched in the cytoplasm and no periodic PER nuclear accumulation was observed. These results suggest that repression of CLK/CYC-mediated transcription by nuclear PER is impaired, and thus the negative feedback loop of the molecular clock is incomplete in isolated clock neurons. We further demonstrate that, by pharmacological assays using the non-amidated form of neuropeptide pigment-dispersing factor (PDF), which could be specifically secreted from larval LNvs and adult s-LNvs, downstream events of the PDF signaling are partly impaired in dissociated larval clock neurons. Although non-amidated PDF is likely to be less active than the amidated one, these results point out the possibility that alteration in PDF downstream signaling may play a role in dampening of molecular rhythms in isolated clock neurons. Taken together, our results suggest that Drosophila clocks are weak oscillators that need to be in the intact circadian circuit to generate robust 24-h rhythms.

Single-cell gene expression profiling reveals functional heterogeneity of undifferentiated human epidermal cells

PubMed Central

Tan, David W. M.; Jensen, Kim B.; Trotter, Matthew W. B.; Connelly, John T.; Broad, Simon; Watt, Fiona M.

2013-01-01

Human epidermal stem cells express high levels of β1 integrins, delta-like 1 (DLL1) and the EGFR antagonist LRIG1. However, there is cell-to-cell variation in the relative abundance of DLL1 and LRIG1 mRNA transcripts. Single-cell global gene expression profiling showed that undifferentiated cells fell into two clusters delineated by expression of DLL1 and its binding partner syntenin. The DLL1+ cluster had elevated expression of genes associated with endocytosis, integrin-mediated adhesion and receptor tyrosine kinase signalling. Differentially expressed genes were not independently regulated, as overexpression of DLL1 alone or together with LRIG1 led to the upregulation of other genes in the DLL1+ cluster. Overexpression of DLL1 and LRIG1 resulted in enhanced extracellular matrix adhesion and increased caveolin-dependent EGFR endocytosis. Further characterisation of CD46, one of the genes upregulated in the DLL1+ cluster, revealed it to be a novel cell surface marker of human epidermal stem cells. Cells with high endogenous levels of CD46 expressed high levels of β1 integrin and DLL1 and were highly adhesive and clonogenic. Knockdown of CD46 decreased proliferative potential and β1 integrin-mediated adhesion. Thus, the previously unknown heterogeneity revealed by our studies results in differences in the interaction of undifferentiated basal keratinocytes with their environment. PMID:23482486

Macrophages and cellular immunity in Drosophila melanogaster.

PubMed

Gold, Katrina S; Brückner, Katja

2015-12-01

The invertebrate Drosophila melanogaster has been a powerful model for understanding blood cell development and immunity. Drosophila is a holometabolous insect, which transitions through a series of life stages from embryo, larva and pupa to adulthood. In spite of this, remarkable parallels exist between Drosophila and vertebrate macrophages, both in terms of development and function. More than 90% of Drosophila blood cells (hemocytes) are macrophages (plasmatocytes), making this highly tractable genetic system attractive for studying a variety of questions in macrophage biology. In vertebrates, recent findings revealed that macrophages have two independent origins: self-renewing macrophages, which reside and proliferate in local microenvironments in a variety of tissues, and macrophages of the monocyte lineage, which derive from hematopoietic stem or progenitor cells. Like vertebrates, Drosophila possesses two macrophage lineages with a conserved dual ontogeny. These parallels allow us to take advantage of the Drosophila model when investigating macrophage lineage specification, maintenance and amplification, and the induction of macrophages and their progenitors by local microenvironments and systemic cues. Beyond macrophage development, Drosophila further serves as a paradigm for understanding the mechanisms underlying macrophage function and cellular immunity in infection, tissue homeostasis and cancer, throughout development and adult life. Copyright © 2016. Published by Elsevier Ltd.

Macrophages and cellular immunity in Drosophila melanogaster

PubMed Central

Gold, Katrina S.; Brückner, Katja

2016-01-01

The invertebrate Drosophila melanogaster has been a powerful model for understanding blood cell development and immunity. Drosophila is a holometabolous insect, which transitions through a series of life stages from embryo, larva and pupa to adulthood. In spite of this, remarkable parallels exist between Drosophila and vertebrate macrophages, both in terms of development and function. More than 90% of Drosophila blood cells (hemocytes) are macrophages (plasmatocytes), making this highly tractable genetic system attractive for studying a variety of questions in macrophage biology. In vertebrates, recent findings revealed that macrophages have two independent origins: self-renewing macrophages, which reside and proliferate in local microenvironments in a variety of tissues, and macrophages of the monocyte lineage, which derive from hematopoietic stem or progenitor cells. Like vertebrates, Drosophila possesses two macrophage lineages with a conserved dual ontogeny. These parallels allow us to take advantage of the Drosophila model when investigating macrophage lineage specification, maintenance and amplification, and the induction of macrophages and their progenitors by local microenvironments and systemic cues. Beyond macrophage development, Drosophila further serves as a paradigm for understanding the mechanisms underlying macrophage function and cellular immunity in infection, tissue homeostasis and cancer, throughout development and adult life. PMID:27117654

Histological study of the gastrointestinal tract in longfin yellowtail (Seriola rivoliana) larvae.

PubMed

Teles, Andressa; Salas-Leiva, Joan; Alvarez-González, Carlos Alfonso; Gisbert, Enric; Ibarra-Castro, Leonardo; Urbiola, Juan Carlos Pérez; Tovar-Ramírez, Dariel

2017-12-01

This work contributes basic knowledge on larval development of Seriola rivoliana. A histological study describes the development of the digestive tract and accessory glands in S. rivoliana larvae reared under laboratory conditions at 24 °C from hatching to 30 days post-hatching (DPH). At hatching (2.6 ± 0.12 mm), larvae had an undifferentiated digestive tract with a closed straight tube and a large yolk sac with an oil globule. The liver and pancreas were observed at 1 and 2 days, and the mouth and anus opened at day 2. Enriched rotifers were visible in their digestive tract. At the beginning of the pre-flexion stage, a mixed nutritional period was observed. At day 3, exogenous feeding began; the digestive tract became differentiated into the buccopharynx, esophagus, an undifferentiated stomach, and the intestines. Zymogen granules were visible in the exocrine pancreas. At day 4, supranuclear vacuoles were present in the posterior intestine, indicating the beginning of intracellular digestion. At day 5, goblet cells were present in the esophagus and became functional at day 7 in the esophagus and intestine. The buccopharynx goblet cells developed at day 15. The presence of gastric glands and differentiation of the stomach in the fundic, cardiac, and pyloric regions during the post-flexion stage occurred at day 20. This was the onset of the juvenile period and the beginning of weaning; however, a long co-feeding phase is recommended. Pyloric caeca were observed at day 30 (13.6 ± 1.6 mm). These results provide valuable information on S. rivoliana larvae biology and digestive physiology, which should be useful to improve cultivation techniques and identify ecological features involved in ontogeny.

Dissecting social cell biology and tumors using Drosophila genetics.

PubMed

Pastor-Pareja, José Carlos; Xu, Tian

2013-01-01

Cancer was seen for a long time as a strictly cell-autonomous process in which oncogenes and tumor-suppressor mutations drive clonal cell expansions. Research in the past decade, however, paints a more integrative picture of communication and interplay between neighboring cells in tissues. It is increasingly clear as well that tumors, far from being homogenous lumps of cells, consist of different cell types that function together as complex tissue-level communities. The repertoire of interactive cell behaviors and the quantity of cellular players involved call for a social cell biology that investigates these interactions. Research into this social cell biology is critical for understanding development of normal and tumoral tissues. Such complex social cell biology interactions can be parsed in Drosophila. Techniques in Drosophila for analysis of gene function and clonal behavior allow us to generate tumors and dissect their complex interactive biology with cellular resolution. Here, we review recent Drosophila research aimed at understanding tissue-level biology and social cell interactions in tumors, highlighting the principles these studies reveal.

Tailless-like (TLX) protein promotes neuronal differentiation of dermal multipotent stem cells and benefits spinal cord injury in rats.

PubMed

Wang, Tao; Ren, Xiaobao; Xiong, Jianqiong; Zhang, Lei; Qu, Jifu; Xu, Wenyue

2011-04-01

Spinal cord injury (SCI) remains a formidable challenge in the clinic. In the current study, we examined the effects of the TLX gene on the proliferation and neuronal differentiation of dermal multipotent stem cells (DMSCs) in vitro and the potential of these cells to improve SCI in rats in vivo. DMSCs were stably transfected with TLX-expressing plasmid (TLX/DMSCs). Cell proliferation was examined using the MTT assay, and neuronal differentiation was characterized by morphological observation combined with immunocytochemical/immunofluorescent staining. The in vivo functions of these cells were evaluated by transplantation into rats with SCI, followed by analysis of hindlimb locomotion and post-mortem histology. Compared to parental DMSCs, TLX/DMSCs showed enhanced proliferation and preferential differentiation into NF200-positive neurons in contrast to GFAP-positive astrocytes. When the undifferentiated cells were transplanted into rats with SCI injury, TLX/DMSCs led to significant improvement in locomotor recovery and healing of SCI, as evidenced by reduction in scar tissues and cavities, increase in continuous nerve fibers/axons and enrichment of NF200-positive neurons on the histological level. In conclusion, TLX promotes the proliferation and neuronal differentiation of DMSCs and thus, may serve as a promising therapy for SCI in the clinic.

A cell-based assay for aggregation inhibitors as therapeutics of polyglutamine-repeat disease and validation in Drosophila

NASA Astrophysics Data System (ADS)

Apostol, Barbara L.; Kazantsev, Alexsey; Raffioni, Simona; Illes, Katalin; Pallos, Judit; Bodai, Laszlo; Slepko, Natalia; Bear, James E.; Gertler, Frank B.; Hersch, Steven; Housman, David E.; Marsh, J. Lawrence; Michels Thompson, Leslie

2003-05-01

The formation of polyglutamine-containing aggregates and inclusions are hallmarks of pathogenesis in Huntington's disease that can be recapitulated in model systems. Although the contribution of inclusions to pathogenesis is unclear, cell-based assays can be used to screen for chemical compounds that affect aggregation and may provide therapeutic benefit. We have developed inducible PC12 cell-culture models to screen for loss of visible aggregates. To test the validity of this approach, compounds that inhibit aggregation in the PC12 cell-based screen were tested in a Drosophila model of polyglutamine-repeat disease. The disruption of aggregation in PC12 cells strongly correlates with suppression of neuronal degeneration in Drosophila. Thus, the engineered PC12 cells coupled with the Drosophila model provide a rapid and effective method to screen and validate compounds.

Transcriptome Profiling Identifies Multiplexin as a Target of SAGA Deubiquitinase Activity in Glia Required for Precise Axon Guidance During Drosophila Visual Development.

PubMed

Ma, Jingqun; Brennan, Kaelan J; D'Aloia, Mitch R; Pascuzzi, Pete E; Weake, Vikki M

2016-08-09

The Spt-Ada-Gcn5 Acetyltransferase (SAGA) complex is a transcriptional coactivator with histone acetylase and deubiquitinase activities that plays an important role in visual development and function. In Drosophila melanogaster, four SAGA subunits are required for the deubiquitination of monoubiquitinated histone H2B (ubH2B): Nonstop, Sgf11, E(y)2, and Ataxin 7. Mutations that disrupt SAGA deubiquitinase activity cause defects in neuronal connectivity in the developing Drosophila visual system. In addition, mutations in SAGA result in the human progressive visual disorder spinocerebellar ataxia type 7 (SCA7). Glial cells play a crucial role in both the neuronal connectivity defect in nonstop and sgf11 flies, and in the retinal degeneration observed in SCA7 patients. Thus, we sought to identify the gene targets of SAGA deubiquitinase activity in glia in the Drosophila larval central nervous system. To do this, we enriched glia from wild-type, nonstop, and sgf11 larval optic lobes using affinity-purification of KASH-GFP tagged nuclei, and then examined each transcriptome using RNA-seq. Our analysis showed that SAGA deubiquitinase activity is required for proper expression of 16% of actively transcribed genes in glia, especially genes involved in proteasome function, protein folding and axon guidance. We further show that the SAGA deubiquitinase-activated gene Multiplexin (Mp) is required in glia for proper photoreceptor axon targeting. Mutations in the human ortholog of Mp, COL18A1, have been identified in a family with a SCA7-like progressive visual disorder, suggesting that defects in the expression of this gene in SCA7 patients could play a role in the retinal degeneration that is unique to this ataxia. Copyright © 2016 Ma et al.

Transcription elongation rate has a tissue-specific impact on alternative cleavage and polyadenylation in Drosophila melanogaster.

PubMed

Liu, Xiaochuan; Freitas, Jaime; Zheng, Dinghai; Oliveira, Marta S; Hoque, Mainul; Martins, Torcato; Henriques, Telmo; Tian, Bin; Moreira, Alexandra

2017-12-01

Alternative polyadenylation (APA) is a mechanism that generates multiple mRNA isoforms with different 3'UTRs and/or coding sequences from a single gene. Here, using 3' region extraction and deep sequencing (3'READS), we have systematically mapped cleavage and polyadenylation sites (PASs) in Drosophila melanogaster , expanding the total repertoire of PASs previously identified for the species, especially those located in A-rich genomic sequences. Cis -element analysis revealed distinct sequence motifs around fly PASs when compared to mammalian ones, including the greater enrichment of upstream UAUA elements and the less prominent presence of downstream UGUG elements. We found that over 75% of mRNA genes in Drosophila melanogaster undergo APA. The head tissue tends to use distal PASs when compared to the body, leading to preferential expression of APA isoforms with long 3'UTRs as well as with distal terminal exons. The distance between the APA sites and intron location of PAS are important parameters for APA difference between body and head, suggesting distinct PAS selection contexts. APA analysis of the RpII215 C4 mutant strain, which harbors a mutant RNA polymerase II (RNAPII) with a slower elongation rate, revealed that a 50% decrease in transcriptional elongation rate leads to a mild trend of more usage of proximal, weaker PASs, both in 3'UTRs and in introns, consistent with the "first come, first served" model of APA regulation. However, this trend was not observed in the head, suggesting a different regulatory context in neuronal cells. Together, our data expand the PAS collection for Drosophila melanogaster and reveal a tissue-specific effect of APA regulation by RNAPII elongation rate. © 2017 Liu et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Glycosyltransferase ST6GAL1 contributes to the regulation of pluripotency in human pluripotent stem cells

PubMed Central

Wang, Yu-Chieh; Stein, Jason W.; Lynch, Candace L.; Tran, Ha T.; Lee, Chia-Yao; Coleman, Ronald; Hatch, Adam; Antontsev, Victor G.; Chy, Hun S.; O’Brien, Carmel M.; Murthy, Shashi K.; Laslett, Andrew L.; Peterson, Suzanne E.; Loring, Jeanne F.

2015-01-01

Many studies have suggested the significance of glycosyltransferase-mediated macromolecule glycosylation in the regulation of pluripotent states in human pluripotent stem cells (hPSCs). Here, we observed that the sialyltransferase ST6GAL1 was preferentially expressed in undifferentiated hPSCs compared to non-pluripotent cells. A lectin which preferentially recognizes α-2,6 sialylated galactosides showed strong binding reactivity with undifferentiated hPSCs and their glycoproteins, and did so to a much lesser extent with differentiated cells. In addition, downregulation of ST6GAL1 in undifferentiated hPSCs led to a decrease in POU5F1 (also known as OCT4) protein and significantly altered the expression of many genes that orchestrate cell morphogenesis during differentiation. The induction of cellular pluripotency in somatic cells was substantially impeded by the shRNA-mediated suppression of ST6GAL1, partially through interference with the expression of endogenous POU5F1 and SOX2. Targeting ST6GAL1 activity with a sialyltransferase inhibitor during cell reprogramming resulted in a dose-dependent reduction in the generation of human induced pluripotent stem cells (hiPSCs). Collectively, our data indicate that ST6GAL1 plays an important role in the regulation of pluripotency and differentiation in hPSCs, and the pluripotent state in human cells can be modulated using pharmacological tools to target sialyltransferase activity. PMID:26304831

Convective exosome-tracing microfluidics for analysis of cell-non-autonomous neurogenesis.

PubMed

Oh, Hyun Jeong; Shin, Yoojin; Chung, Seok; Hwang, Do Won; Lee, Dong Soo

2017-01-01

The effective role of exosome delivering neurogenic microRNA (miRNA) enables to induce efficient differentiation process during neurogenesis. The microfludic system capable of visualizing the exosomal behavior such as secretion, migration, and uptake of individual exosomes can be used as a robust technique to understand the exosome-mediated change of cellular behavior. Here, we developed the exosome-tracing microfluidic system to visualize exosomal transport carrying the neurogenic miRNA from leading to neighboring cells, and found a new mode of exosome-mediated cell-non-autonomous neurogenesis. The miR-193a facilitated neurogenesis in F11 cells by blocking proliferation-related target genes. In addition to time-lapse live-cell imaging using microfluidics visualized the convective transport of exosomes from differentiated to undifferentiated cells. Individual exosomes containing miR-193a from differentiated donor cells were taken up by undifferentiated cells to lead them to neurogenesis. Induction of anti-miR-193a was sufficient to block neurogenesis in F11 cells. Inhibition of the exosomal production by manumycin-A and treatment of anti-miR-193a in the differentiated donor cells failed to induce neurogenesis in undifferentiated recipient cells. These findings indicate that exosomes of neural progenitors and neurogenic miRNA within these exosomes propagate cell-non-autonomous differentiation to neighboring progenitors, to delineate the roles of exosome mediating neurogenesis of population of homologous neural progenitor cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

Genome-Wide Analysis Reveals Novel Regulators of Growth in Drosophila melanogaster

PubMed Central

Vonesch, Sibylle Chantal; Lamparter, David; Mackay, Trudy F. C.; Bergmann, Sven; Hafen, Ernst

2016-01-01

Organismal size depends on the interplay between genetic and environmental factors. Genome-wide association (GWA) analyses in humans have implied many genes in the control of height but suffer from the inability to control the environment. Genetic analyses in Drosophila have identified conserved signaling pathways controlling size; however, how these pathways control phenotypic diversity is unclear. We performed GWA of size traits using the Drosophila Genetic Reference Panel of inbred, sequenced lines. We find that the top associated variants differ between traits and sexes; do not map to canonical growth pathway genes, but can be linked to these by epistasis analysis; and are enriched for genes and putative enhancers. Performing GWA on well-studied developmental traits under controlled conditions expands our understanding of developmental processes underlying phenotypic diversity. PMID:26751788

Drosophila comes of age as a model system for understanding the function of cytoskeletal proteins in cells, tissues, and organisms.

PubMed

Rodal, Avital A; Del Signore, Steven J; Martin, Adam C

2015-05-01

For the last 100 years, Drosophila melanogaster has been a powerhouse genetic system for understanding mechanisms of inheritance, development, and behavior in animals. In recent years, advances in imaging and genetic tools have led to Drosophila becoming one of the most effective systems for unlocking the subcellular functions of proteins (and particularly cytoskeletal proteins) in complex developmental settings. In this review, written for non-Drosophila experts, we will discuss critical technical advances that have enabled these cell biological insights, highlighting three examples of cytoskeletal discoveries that have arisen as a result: (1) regulation of Arp2/3 complex in myoblast fusion, (2) cooperation of the actin filament nucleators Spire and Cappuccino in establishment of oocyte polarity, and (3) coordination of supracellular myosin cables. These specific examples illustrate the unique power of Drosophila both to uncover new cytoskeletal structures and functions, and to place these discoveries in a broader in vivo context, providing insights that would have been impossible in a cell culture model or in vitro. Many of the cellular structures identified in Drosophila have clear counterparts in mammalian cells and tissues, and therefore elucidating cytoskeletal functions in Drosophila will be broadly applicable to other organisms. © 2015 Wiley Periodicals, Inc.

Identification of genes expressed in the hermaphrodite germ line of C. elegans using SAGE

PubMed Central

Wang, Xin; Zhao, Yongjun; Wong, Kim; Ehlers, Peter; Kohara, Yuji; Jones, Steven J; Marra, Marco A; Holt, Robert A; Moerman, Donald G; Hansen, Dave

2009-01-01

Background Germ cells must progress through elaborate developmental stages from an undifferentiated germ cell to a fully differentiated gamete. Some of these stages include exiting mitosis and entering meiosis, progressing through the various stages of meiotic prophase, adopting either a male (sperm) or female (oocyte) fate, and completing meiosis. Additionally, many of the factors needed to drive embryogenesis are synthesized in the germ line. To increase our understanding of the genes that might be necessary for the formation and function of the germ line, we have constructed a SAGE library from hand dissected C. elegans hermaphrodite gonads. Results We found that 4699 genes, roughly 21% of all known C. elegans genes, are expressed in the adult hermaphrodite germ line. Ribosomal genes are highly expressed in the germ line; roughly four fold above their expression levels in the soma. We further found that 1063 of the germline-expressed genes have enriched expression in the germ line as compared to the soma. A comparison of these 1063 germline-enriched genes with a similar list of genes prepared using microarrays revealed an overlap of 460 genes, mutually reinforcing the two lists. Additionally, we identified 603 germline-enriched genes, supported by in situ expression data, which were not previously identified. We also found >4 fold enrichment for RNA binding proteins in the germ line as compared to the soma. Conclusion Using multiple technological platforms provides a more complete picture of global gene expression patterns. Genes involved in RNA metabolism are expressed at a significantly higher level in the germ line than the soma, suggesting a stronger reliance on RNA metabolism for control of the expression of genes in the germ line. Additionally, the number and expression level of germ line expressed genes on the X chromosome is lower than expected based on a random distribution. PMID:19426519

Stem cells in the Drosophila digestive system.

PubMed

Zeng, Xiankun; Chauhan, Chhavi; Hou, Steven X

2013-01-01

Adult stem cells maintain tissue homeostasis by continuously replenishing damaged, aged and dead cells in any organism. Five types of region and organ-specific multipotent adult stem cells have been identified in the Drosophila digestive system: intestinal stem cells (ISCs) in the posterior midgut; hindgut intestinal stem cells (HISCs) at the midgut/hindgut junction; renal and nephric stem cells (RNSCs) in the Malpighian Tubules; type I gastric stem cells (GaSCs) at foregut/midgut junction; and type II gastric stem cells (GSSCs) at the middle of the midgut. Despite the fact that each type of stem cell is unique to a particular organ, they share common molecular markers and some regulatory signaling pathways. Due to the simpler tissue structure, ease of performing genetic analysis, and availability of abundant mutants, Drosophila serves as an elegant and powerful model system to study complex stem cell biology. The recent discoveries, particularly in the Drosophila ISC system, have greatly advanced our understanding of stem cell self-renewal, differentiation, and the role of stem cells play in tissue homeostasis/regeneration and adaptive tissue growth.

Neuroglian and DE-cadherin activate independent cytoskeleton assembly pathways in Drosophila S2 cells.

PubMed

Dubreuil, R R; Grushko, T

1999-11-19

The cytoskeletal proteins spectrin and ankyrin colocalize with sites of E-cadherin-mediated cell-cell adhesion in mammalian cells. Here we examined the effects of Drosophila DE-cadherin expression on spectrin and ankyrin in Drosophila S2 tissue culture cells. DE-cadherin caused a dramatic change in the cytoplasmic concentration and distribution of armadillo, the Drosophila homolog of beta catenin. However, DE-cadherin expression had no detectable effect on the quantity or subcellular distribution of ankyrin or spectrin. In reciprocal experiments, recruitment of ankyrin and alphabeta spectrin to the plasma membrane by another cell adhesion molecule, neuroglian, had no effect on the quantity or distribution of armadillo. The results indicate that DE-cadherin-catenin complexes and neuroglian-spectrin/ankyrin complexes form by nonintersecting pathways. Recruitment of spectrin does not appear to be a conserved feature of DE-cadherin function. Copyright 1999 Academic Press.

Stem-Cell-Based Tumorigenesis in Adult Drosophila.

PubMed

Hou, S X; Singh, S R

2017-01-01

Recent studies suggest that a small subset of cells within a tumor, the so-called cancer stem cells (CSCs), are responsible for tumor propagation, relapse, and the eventual death of most cancer patients. CSCs may derive from a few tumor-initiating cells, which are either transformed normal stem cells or reprogrammed differentiated cells after acquiring initial cancer-causing mutations. CSCs and normal stem cells share some properties, but CSCs differ from normal stem cells in their tumorigenic ability. Notably, CSCs are usually resistant to chemo- and radiation therapies. Despite the apparent roles of CSCs in human cancers, the biology underlying their behaviors remains poorly understood. Over the past few years, studies in Drosophila have significantly contributed to this new frontier of cancer research. Here, we first review how stem-cell tumors are initiated and propagated in Drosophila, through niche appropriation in the posterior midgut and through stem-cell competition for niche occupancy in the testis. We then discuss the differences between normal and tumorigenic stem cells, revealed by studying Ras V12 -transformed stem-cell tumors in the Drosophila kidney. Finally, we review the biology behind therapy resistance, which has been elucidated through studies of stem-cell resistance and sensitivity to death inducers using female germline stem cells and intestinal stem cells of the posterior midgut. We expect that screens using adult Drosophila neoplastic stem-cell tumor models will be valuable for identifying novel and effective compounds for treating human cancers. © 2017 Elsevier Inc. All rights reserved.

Drosophila cellular immunity: a story of migration and adhesion.

PubMed

Fauvarque, Marie-Odile; Williams, Michael J

2011-05-01

Research during the past 15 years has led to significant breakthroughs, providing evidence of a high degree of similarity between insect and mammalian innate immune responses, both humoural and cellular, and highlighting Drosophila melanogaster as a model system for studying the evolution of innate immunity. In a manner similar to cells of the mammalian monocyte and macrophage lineage, Drosophila immunosurveillance cells (haemocytes) have a number of roles. For example, they respond to wound signals, are involved in wound healing and contribute to the coagulation response. Moreover, they participate in the phagocytosis and encapsulation of invading pathogens, are involved in the removal of apoptotic bodies and produce components of the extracellular matrix. There are several reasons for using the Drosophila cellular immune response as a model to understand cell signalling during adhesion and migration in vivo: many genes involved in the regulation of Drosophila haematopoiesis and cellular immunity have been maintained across taxonomic groups ranging from flies to humans, many aspects of Drosophila and mammalian innate immunity seem to be conserved, and Drosophila is a simplified and well-studied genetic model system. In the present Commentary, we will discuss what is known about cellular adhesion and migration in the Drosophila cellular immune response, during both embryonic and larval development, and where possible compare it with related mechanisms in vertebrates.

Nematocytes: Discovery and characterization of a novel anculeate hemocyte in Drosophila falleni and Drosophila phalerata.

PubMed

Bozler, Julianna; Kacsoh, Balint Z; Bosco, Giovanni

2017-01-01

Immune challenges, such as parasitism, can be so pervasive and deleterious that they constitute an existential threat to a species' survival. In response to these ecological pressures, organisms have developed a wide array of novel behavioral, cellular, and molecular adaptations. Research into these immune defenses in model systems has resulted in a revolutionary understanding of evolution and functional biology. As the field has expanded beyond the limited number of model organisms our appreciation of evolutionary innovation and unique biology has widened as well. With this in mind, we have surveyed the hemolymph of several non-model species of Drosophila. Here we identify and describe a novel hemocyte, type-II nematocytes, found in larval stages of numerous Drosophila species. Examined in detail in Drosophila falleni and Drosophila phalerata, we find that these remarkable cells are distinct from previously described hemocytes due to their anucleate state (lacking a nucleus) and unusual morphology. Type-II nematocytes are long, narrow cells with spindle-like projections extending from a cell body with high densities of mitochondria and microtubules, and exhibit the ability to synthesize proteins. These properties are unexpected for enucleated cells, and together with our additional characterization, we demonstrate that these type-II nematocytes represent a biological novelty. Surprisingly, despite the absence of a nucleus, we observe through live cell imaging that these cells remain motile with a highly dynamic cellular shape. Furthermore, these cells demonstrate the ability to form multicellular structures, which we suggest may be a component of the innate immune response to macro-parasites. In addition, live cell imaging points to a large nucleated hemocyte, type-I nematocyte, as the progenitor cell, leading to enucleation through a budding or asymmetrical division process rather than nuclear ejection: This study is the first to report such a process of enucleation. Here we describe these cells in detail for the first time and examine their evolutionary history in Drosophila.

DE-Cadherin Is Required for Intercellular Motility during Drosophila Oogenesis

PubMed Central

Niewiadomska, Paulina; Godt, Dorothea; Tepass, Ulrich

1999-01-01

Cadherins are involved in a variety of morphogenetic movements during animal development. However, it has been difficult to pinpoint the precise function of cadherins in morphogenetic processes due to the multifunctional nature of cadherin requirement. The data presented here indicate that homophilic adhesion promoted by Drosophila E-cadherin (DE-cadherin) mediates two cell migration events during Drosophila oogenesis. In Drosophila follicles, two groups of follicle cells, the border cells and the centripetal cells migrate on the surface of germline cells. We show that the border cells migrate as an epithelial patch in which two centrally located cells retain epithelial polarity and peripheral cells are partially depolarized. Both follicle cells and germline cells express DE-cadherin, and border cells and centripetal cells strongly upregulate the expression of DE-cadherin shortly before and during their migration. Removing DE-cadherin from either the follicle cells or the germline cells blocks migration of border cells and centripetal cells on the surface of germline cells. The function of DE-cadherin in border cells appears to be specific for migration as the formation of the border cell cluster and the adhesion between border cells are not disrupted in the absence of DE-cadherin. The speed of migration depends on the level of DE-cadherin expression, as border cells migrate more slowly when DE-cadherin activity is reduced. Finally, we show that the upregulation of DE-cadherin expression in border cells depends on the activity of the Drosophila C/EBP transcription factor that is essential for border cell migration. PMID:9971747

DIP1 modulates stem cell homeostasis in Drosophila through regulation of sisR-1.

PubMed

Wong, Jing Ting; Akhbar, Farzanah; Ng, Amanda Yunn Ee; Tay, Mandy Li-Ian; Loi, Gladys Jing En; Pek, Jun Wei

2017-10-02

Stable intronic sequence RNAs (sisRNAs) are by-products of splicing and regulate gene expression. How sisRNAs are regulated is unclear. Here we report that a double-stranded RNA binding protein, Disco-interacting protein 1 (DIP1) regulates sisRNAs in Drosophila. DIP1 negatively regulates the abundance of sisR-1 and INE-1 sisRNAs. Fine-tuning of sisR-1 by DIP1 is important to maintain female germline stem cell homeostasis by modulating germline stem cell differentiation and niche adhesion. Drosophila DIP1 localizes to a nuclear body (satellite body) and associates with the fourth chromosome, which contains a very high density of INE-1 transposable element sequences that are processed into sisRNAs. DIP1 presumably acts outside the satellite bodies to regulate sisR-1, which is not on the fourth chromosome. Thus, our study identifies DIP1 as a sisRNA regulatory protein that controls germline stem cell self-renewal in Drosophila.Stable intronic sequence RNAs (sisRNAs) are by-products of splicing from introns with roles in embryonic development in Drosophila. Here, the authors show that the RNA binding protein DIP1 regulates sisRNAs in Drosophila, which is necessary for germline stem cell homeostasis.

Method for evaluation of human induced pluripotent stem cell quality using image analysis based on the biological morphology of cells.

PubMed

Wakui, Takashi; Matsumoto, Tsuyoshi; Matsubara, Kenta; Kawasaki, Tomoyuki; Yamaguchi, Hiroshi; Akutsu, Hidenori

2017-10-01

We propose an image analysis method for quality evaluation of human pluripotent stem cells based on biologically interpretable features. It is important to maintain the undifferentiated state of induced pluripotent stem cells (iPSCs) while culturing the cells during propagation. Cell culture experts visually select good quality cells exhibiting the morphological features characteristic of undifferentiated cells. Experts have empirically determined that these features comprise prominent and abundant nucleoli, less intercellular spacing, and fewer differentiating cellular nuclei. We quantified these features based on experts' visual inspection of phase contrast images of iPSCs and found that these features are effective for evaluating iPSC quality. We then developed an iPSC quality evaluation method using an image analysis technique. The method allowed accurate classification, equivalent to visual inspection by experts, of three iPSC cell lines.

Myeloblastic and lymphoblastic markers in acute undifferentiated leukemia and chronic myelogenous leukemia in blast crisis.

PubMed

Shumak, K H; Baker, M A; Taub, R N; Coleman, M S

1980-11-01

Blast cells were obtained from 17 patients with acute undifferentiated leukemia and 13 patients with chronic myelogenous leukemia in blast crisis. The blasts were tested with anti-i serum in cytotoxicity tests and with antisera to myeloblastic leukemia-associated antigens in immunofluorescence tests. The terminal deoxynucleotidyl transferase (TDT) content of the blasts was also measured. Lymphoblasts react strongly with anti-i, do not react with anti-myeloblast serum, and have high levels of TDT; myeloblasts react weakly with anti-i, do not react with anti-myeloblast serum, and have very low levels of TDT. Of the 17 patients with acute undifferentiated leukemia, there were six with blasts which reacted like lymphoblasts, six with blasts which reacted like myeloblasts, and five with blasts bearing different combinations of these lymphoblastic and myeloblastic markers. Eight of the 11 patients with lymphoblastic or mixed lymphoblastic-myeloblastic markers, but only one of the six with myeloblastic markers, achieved complete or partial remission in response to therapy. Thus, in acute undifferentiated leukemia, classification of blasts with these markers may be of prognostic value. Of the 13 patients with chronic myelogenous leukemia in blast crises, the markers were concordant (for myeloblasts) in only two cases. Three of the 13 patients had TDT-positive blasts, but the reactions of these cells with anti-i and with anti-myeloblast serum differed from those seen with lymphoblasts from patients with acute lymphoblastic leukemia. Although the cell involved in "lymphoid" blast crisis of chronic myelogenous leukemia is similar in many respects to that involved in acute lymphoblastic leukemia, these cells are not identical.

Contrast-enhanced CT features of hepatoblastoma: Can we predict histopathology?

PubMed

Baheti, Akshay D; Luana Stanescu, A; Li, Ning; Chapman, Teresa

Hepatoblastoma is the most common hepatic malignancy occurring in the pediatric population. Intratumoral cellular behavior varies, and the small-cell undifferentiated histopathology carries a poorer prognosis than other tissue subtypes. Neoadjuvant chemotherapy is recommended for this tumor subtype prior to surgical resection in most cases. Early identification of tumors with poor prognosis could have a significant clinical impact. Objective The aim of this work was to identify imaging features of small-cell undifferentiated subtype hepatoblastoma that can help distinguish this subtype from more favorable tumors and potentially guide the clinical management. We also sought to characterize contrast-enhanced CT (CECT) features of hepatoblastoma that correlate with metastatic disease and patient outcome. Our study included 34 patients (24 males, 10 females) with a mean age of 16months (range: 0-46months) with surgically confirmed hepatoblastoma and available baseline abdominal imaging by CECT. Clinical data and CT abdominal images were retrospectively analyzed. Five tumors with small-cell undifferentiated components were identified. All of these tumors demonstrated irregular margins on CT imaging. Advanced PRETEXT stage, vascular invasion and irregular margins were associated with metastatic disease and decreased survival. Capsular retraction was also significantly associated with decreased survival. Irregular tumor margins demonstrated statistically significant association with the presence of small-cell undifferentiated components. No other imaging feature showed statistically significant association. Tumor margin irregularity, vascular invasion, capsular retraction, and PRETEXT stage correlate with worse patient outcomes. Irregular tumor margin was the only imaging feature significantly associated with more aggressive tumor subtype. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of all-trans-retinoic acid on human SH-SY5Y neuroblastoma as in vitro model in neurotoxicity research.

PubMed

Cheung, Yuen-Ting; Lau, Way Kwok-Wai; Yu, Man-Shan; Lai, Cora Sau-Wan; Yeung, Sze-Chun; So, Kwok-Fai; Chang, Raymond Chuen-Chung

2009-01-01

Human neuroblastoma SH-SY5Y is a dopaminergic neuronal cell line which has been used as an in vitro model for neurotoxicity experiments. Although the neuroblastoma is usually differentiated by all-trans-retinoic acid (RA), both RA-differentiated and undifferentiated SH-SY5Y cells have been used in neuroscience research. However, the changes in neuronal properties triggered by RA as well as the subsequent responsiveness to neurotoxins have not been comprehensively studied. Therefore, we aim to re-evaluate the differentiation property of RA on this cell line. We hypothesize that modulation of signaling pathways and neuronal properties during RA-mediated differentiation in SH-SY5Y cells can affect their susceptibility to neurotoxins. The differentiation property of RA was confirmed by showing an extensive outgrowth of neurites, increased expressions of neuronal nuclei, neuron specific enolase, synaptophysin and synaptic associated protein-97, and decreased expression of inhibitor of differentiation-1. While undifferentiated SH-SY5Y cells were susceptible to 6-OHDA and MPP+, RA-differentiation conferred SH-SY5Y cells higher tolerance, potentially by up-regulating survival signaling, including Akt pathway as inhibition of Akt removed RA-induced neuroprotection against 6-OHDA. As a result, the real toxicity cannot be revealed in RA-differentiated cells. Therefore, undifferentiated SH-SY5Y is more appropriate for studying neurotoxicity or neuroprotection in experimental Parkinson's disease research.

Inhibition of hypoxia inducible factors combined with all-trans retinoic acid treatment enhances glial transdifferentiation of neuroblastoma cells.

PubMed

Cimmino, Flora; Pezone, Lucia; Avitabile, Marianna; Acierno, Giovanni; Andolfo, Immacolata; Capasso, Mario; Iolascon, Achille

2015-06-09

Neuroblastoma (NBL) is a heterogeneous tumor characterized by a wide range of clinical manifestations. A high tumor cell differentiation grade correlates to a favorable stage and positive outcome. Expression of the hypoxia inducible factors HIF1-α (HIF1A gene) and HIF2-α (EPAS1 gene) and/or hypoxia-regulated pathways has been shown to promote the undifferentiated phenotype of NBL cells. Our hypothesis is that HIF1A and EPAS1 expression represent one of the mechanisms responsible for the lack of responsiveness of NBL to differentiation therapy. Clinically, high levels of HIF1A and EPAS1 expression were associated with inferior survival in two NBL microarray datasets, and patient subgroups with lower expression of HIF1A and EPAS1 showed significant enrichment of pathways related to neuronal differentiation. In NBL cell lines, the combination of all-trans retinoic acid (ATRA) with HIF1A or EPAS1 silencing led to an acquired glial-cell phenotype and enhanced expression of glial-cell differentiation markers. Furthermore, HIF1A or EPAS1 silencing might promote cell senescence independent of ATRA treatment. Taken together, our data suggest that HIF inhibition coupled with ATRA treatment promotes differentiation into a more benign phenotype and cell senescence in vitro. These findings open the way for additional lines of attack in the treatment of NBL minimal residue disease.

Inhibition of hypoxia inducible factors combined with all-trans retinoic acid treatment enhances glial transdifferentiation of neuroblastoma cells

PubMed Central

Cimmino, Flora; Pezone, Lucia; Avitabile, Marianna; Acierno, Giovanni; Andolfo, Immacolata; Capasso, Mario; Iolascon, Achille

2015-01-01

Neuroblastoma (NBL) is a heterogeneous tumor characterized by a wide range of clinical manifestations. A high tumor cell differentiation grade correlates to a favorable stage and positive outcome. Expression of the hypoxia inducible factors HIF1-α (HIF1A gene) and HIF2-α (EPAS1 gene) and/or hypoxia-regulated pathways has been shown to promote the undifferentiated phenotype of NBL cells. Our hypothesis is that HIF1A and EPAS1 expression represent one of the mechanisms responsible for the lack of responsiveness of NBL to differentiation therapy. Clinically, high levels of HIF1A and EPAS1 expression were associated with inferior survival in two NBL microarray datasets, and patient subgroups with lower expression of HIF1A and EPAS1 showed significant enrichment of pathways related to neuronal differentiation. In NBL cell lines, the combination of all-trans retinoic acid (ATRA) with HIF1A or EPAS1 silencing led to an acquired glial-cell phenotype and enhanced expression of glial-cell differentiation markers. Furthermore, HIF1A or EPAS1 silencing might promote cell senescence independent of ATRA treatment. Taken together, our data suggest that HIF inhibition coupled with ATRA treatment promotes differentiation into a more benign phenotype and cell senescence in vitro. These findings open the way for additional lines of attack in the treatment of NBL minimal residue disease. PMID:26057707

Paclitaxel, Polyglutamate Paclitaxel, or Observation in Treating Patients With Stage III or Stage IV Ovarian Epithelial, Peritoneal Cancer, or Fallopian Tube Cancer

ClinicalTrials.gov

2017-05-03

Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Adenocarcinoma; Fallopian Tube Mucinous Adenocarcinoma; Fallopian Tube Serous Adenocarcinoma; Fallopian Tube Transitional Cell Carcinoma; Ovarian Brenner Tumor; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Adenocarcinoma; Ovarian Seromucinous Carcinoma; Ovarian Serous Adenocarcinoma; Ovarian Transitional Cell Carcinoma; Primary Peritoneal Serous Adenocarcinoma; Stage IIIA Fallopian Tube Cancer; Stage IIIA Ovarian Cancer; Stage IIIA Primary Peritoneal Cancer; Stage IIIB Fallopian Tube Cancer; Stage IIIB Ovarian Cancer; Stage IIIB Primary Peritoneal Cancer; Stage IIIC Fallopian Tube Cancer; Stage IIIC Ovarian Cancer; Stage IIIC Primary Peritoneal Cancer; Stage IV Fallopian Tube Cancer; Stage IV Ovarian Cancer; Stage IV Primary Peritoneal Cancer; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Systematic screen of chemotherapeutics in Drosophila stem cell tumors

PubMed Central

Markstein, Michele; Dettorre, Samantha; Cho, Julio; Neumüller, Ralph A.; Craig-Müller, Sören; Perrimon, Norbert

2014-01-01

Here we report the development of an in vivo system to study the interaction of stem cells with drugs using a tumor model in the adult Drosophila intestine. Strikingly, we find that some Food and Drug Administration-approved chemotherapeutics that can inhibit the growth of Drosophila tumor stem cells can paradoxically promote the hyperproliferation of their wild-type counterparts. These results reveal an unanticipated side effect on stem cells that may contribute to tumor recurrence. We propose that the same side effect may occur in humans based on our finding that it is driven in Drosophila by the evolutionarily conserved Janus kinase-signal transducers and activators of transcription (JAK-STAT) pathway. An immediate implication of our findings is that supplementing traditional chemotherapeutics with anti-inflammatories may reduce tumor recurrence. PMID:24616500

Characterization of a Drosophila ortholog of the Cdc7 kinase: a role for Cdc7 in endoreplication independent of Chiffon.

PubMed

Stephenson, Robert; Hosler, Marcus R; Gavande, Navnath S; Ghosh, Arun K; Weake, Vikki M

2015-01-16

Cdc7 is a serine-threonine kinase that phosphorylates components of the pre-replication complex during DNA replication initiation. Cdc7 is highly conserved, and Cdc7 orthologs have been characterized in organisms ranging from yeast to humans. Cdc7 is activated specifically during late G1/S phase by binding to its regulatory subunit, Dbf4. Drosophila melanogaster contains a Dbf4 ortholog, Chiffon, which is essential for chorion amplification in Drosophila egg chambers. However, no Drosophila ortholog of Cdc7 has yet been characterized. Here, we report the functional and biochemical characterization of a Drosophila ortholog of Cdc7. Co-expression of Drosophila Cdc7 and Chiffon is able to complement a growth defect in yeast containing a temperature-sensitive Cdc7 mutant. Cdc7 and Chiffon physically interact and can be co-purified from insect cells. Cdc7 phosphorylates the known Cdc7 substrates Mcm2 and histone H3 in vitro, and Cdc7 kinase activity is stimulated by Chiffon and inhibited by the Cdc7-specific inhibitor XL413. Drosophila egg chamber follicle cells deficient for Cdc7 have a defect in two types of DNA replication, endoreplication and chorion gene amplification. However, follicle cells deficient for Chiffon have a defect in chorion gene amplification but still undergo endocycling. Our results show that Cdc7 interacts with Chiffon to form a functional Dbf4-dependent kinase complex and that Cdc7 is necessary for DNA replication in Drosophila egg chamber follicle cells. Additionally, we show that Chiffon is a member of an expanding subset of DNA replication initiation factors that are not strictly required for endoreplication in Drosophila. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Drosophila as a model to study the role of blood cells in inflammation, innate immunity and cancer

PubMed Central

Wang, Lihui; Kounatidis, Ilias; Ligoxygakis, Petros

2014-01-01

Drosophila has a primitive yet effective blood system with three types of haemocytes which function throughout different developmental stages and environmental stimuli. Haemocytes play essential roles in tissue modeling during embryogenesis and morphogenesis, and also in innate immunity. The open circulatory system of Drosophila makes haemocytes ideal signal mediators to cells and tissues in response to events such as infection and wounding. The application of recently developed and sophisticated genetic tools to the relatively simple genome of Drosophila has made the fly a popular system for modeling human tumorigensis and metastasis. Drosophila is now used for screening and investigation of genes implicated in human leukemia and also in modeling development of solid tumors. This second line of research offers promising opportunities to determine the seemingly conflicting roles of blood cells in tumor progression and invasion. This review provides an overview of the signaling pathways conserved in Drosophila during haematopoiesis, haemostasis, innate immunity, wound healing and inflammation. We also review the most recent progress in the use of Drosophila as a cancer research model with an emphasis on the roles haemocytes can play in various cancer models and in the links between inflammation and cancer. PMID:24409421

Drosophila as a model to study the role of blood cells in inflammation, innate immunity and cancer.

PubMed

Wang, Lihui; Kounatidis, Ilias; Ligoxygakis, Petros

2014-01-09

Drosophila has a primitive yet effective blood system with three types of haemocytes which function throughout different developmental stages and environmental stimuli. Haemocytes play essential roles in tissue modeling during embryogenesis and morphogenesis, and also in innate immunity. The open circulatory system of Drosophila makes haemocytes ideal signal mediators to cells and tissues in response to events such as infection and wounding. The application of recently developed and sophisticated genetic tools to the relatively simple genome of Drosophila has made the fly a popular system for modeling human tumorigensis and metastasis. Drosophila is now used for screening and investigation of genes implicated in human leukemia and also in modeling development of solid tumors. This second line of research offers promising opportunities to determine the seemingly conflicting roles of blood cells in tumor progression and invasion. This review provides an overview of the signaling pathways conserved in Drosophila during haematopoiesis, haemostasis, innate immunity, wound healing and inflammation. We also review the most recent progress in the use of Drosophila as a cancer research model with an emphasis on the roles haemocytes can play in various cancer models and in the links between inflammation and cancer.

Polytene Chromosomes - A Portrait of Functional Organization of the Drosophila Genome.

PubMed

Zykova, Tatyana Yu; Levitsky, Victor G; Belyaeva, Elena S; Zhimulev, Igor F

2018-04-01

This mini-review is devoted to the problem genetic meaning of main polytene chromosome structures - bands and interbands. Generally, densely packed chromatin forms black bands, moderately condensed regions form grey loose bands, whereas decondensed regions of the genome appear as interbands. Recent progress in the annotation of the Drosophila genome and epigenome has made it possible to compare the banding pattern and the structural organization of genes, as well as their activity. This was greatly aided by our ability to establish the borders of bands and interbands on the physical map, which allowed to perform comprehensive side-by-side comparisons of cytology, genetic and epigenetic maps and to uncover the association between the morphological structures and the functional domains of the genome. These studies largely conclude that interbands 5'-ends of housekeeping genes that are active across all cell types. Interbands are enriched with proteins involved in transcription and nucleosome remodeling, as well as with active histone modifications. Notably, most of the replication origins map to interband regions. As for grey loose bands adjacent to interbands, they typically host the bodies of house-keeping genes. Thus, the bipartite structure composed of an interband and an adjacent grey band functions as a standalone genetic unit. Finally, black bands harbor tissue-specific genes with narrow temporal and tissue expression profiles. Thus, the uniform and permanent activity of interbands combined with the inactivity of genes in bands forms the basis of the universal banding pattern observed in various Drosophila tissues.

Preparation of Drosophila central neurons for in situ patch clamping.

PubMed

Ryglewski, Stefanie; Duch, Carsten

2012-10-15

Short generation times and facile genetic techniques make the fruit fly Drosophila melanogaster an excellent genetic model in fundamental neuroscience research. Ion channels are the basis of all behavior since they mediate neuronal excitability. The first voltage gated ion channel cloned was the Drosophila voltage gated potassium channel Shaker(1,2). Toward understanding the role of ion channels and membrane excitability for nervous system function it is useful to combine powerful genetic tools available in Drosophila with in situ patch clamp recordings. For many years such recordings have been hampered by the small size of the Drosophila CNS. Furthermore, a robust sheath made of glia and collagen constituted obstacles for patch pipette access to central neurons. Removal of this sheath is a necessary precondition for patch clamp recordings from any neuron in the adult Drosophila CNS. In recent years scientists have been able to conduct in situ patch clamp recordings from neurons in the adult brain(3,4) and ventral nerve cord of embryonic(5,6), larval(7,8,9,10), and adult Drosophila(11,12,13,14). A stable giga-seal is the main precondition for a good patch and depends on clean contact of the patch pipette with the cell membrane to avoid leak currents. Therefore, for whole cell in situ patch clamp recordings from adult Drosophila neurons must be cleaned thoroughly. In the first step, the ganglionic sheath has to be treated enzymatically and mechanically removed to make the target cells accessible. In the second step, the cell membrane has to be polished so that no layer of glia, collagen or other material may disturb giga-seal formation. This article describes how to prepare an identified central neuron in the Drosophila ventral nerve cord, the flight motoneuron 5 (MN5(15)), for somatic whole cell patch clamp recordings. Identification and visibility of the neuron is achieved by targeted expression of GFP in MN5. We do not aim to explain the patch clamp technique itself.

The cytoskeleton of Drosophila-derived Schneider line-1 and Kc23 cells undergoes significant changes during long-term culture

NASA Technical Reports Server (NTRS)

Schatten, H.; Hedrick, J.; Chakrabarti, A.

1998-01-01

Insect cell cultures derived from Drosophila melanogaster are increasingly being used as an alternative system to mammalian cell cultures, as they are amenable to genetic manipulation. Although Drosophila cells are an excellent tool for the study of genes and expression of proteins, culture conditions have to be considered in the interpretation of biochemical results. Our studies indicate that significant differences occur in cytoskeletal structure during the long-term culture of the Drosophila-derived cell lines Schneider Line-1 (S1) and Kc23. Scanning, transmission-electron, and immunofluorescence microscopy studies reveal that microfilaments, microtubules, and centrosomes become increasingly different during the culture of these cells from 24 h to 7-14 days. Significant cytoskeletal changes are observed at the cell surface where actin polymerizes into microfilaments, during the elongation of long microvilli. Additionally, long protrusions develop from the cell surface; these protrusions are microtubule-based and establish contact with neighboring cells. In contrast, the microtubule network in the interior of the cells becomes disrupted after four days of culture, resulting in altered transport of mitochondria. Microtubules and centrosomes are also affected in a small percent of cells during cell division, indicating an instability of centrosomes. Thus, the cytoskeletal network of microfilaments, microtubules, and centrosomes is affected in Drosophila cells during long-term culture. This implies that gene regulation and post-translational modifications are probably different under different culture conditions.

Drosophila COP9 signalosome subunit 7 interacts with multiple genomic loci to regulate development

PubMed Central

Singer, Ruth; Atar, Shimshi; Atias, Osnat; Oron, Efrat; Segal, Daniel; Hirsch, Joel A.; Tuller, Tamir; Orian, Amir; Chamovitz, Daniel A.

2014-01-01

The COP9 signalosome protein complex has a central role in the regulation of development of multicellular organisms. While the function of this complex in ubiquitin-mediated protein degradation is well established, results over the past few years have hinted that the COP9 signalosome may function more broadly in the regulation of gene expression. Here, using DamID technology, we show that COP9 signalosome subunit 7 functionally associates with a large number of genomic loci in the Drosophila genome, and show that the expression of many genes within these loci is COP9 signalosome-dependent. This association is likely direct as we show CSN7 binds DNA in vitro. The genes targeted by CSN7 are preferentially enriched for transcriptionally active regions of the genome, and are involved in the regulation of distinct gene ontology groupings including imaginal disc development and cell-cycle control. In accord, loss of CSN7 function leads to cell-cycle delay and altered wing development. These results indicate that CSN7, and by extension the entire COP9 signalosome, functions directly in transcriptional control. While the COP9 signalosome protein complex has long been known to regulate protein degradation, here we expand the role of this complex by showing that subunit 7 binds DNA in vitro and functions directly in vivo in transcriptional control of developmentally important pathways that are relevant for human health. PMID:25106867

Dalantercept in Treating Patients With Recurrent or Persistent Endometrial Cancer

ClinicalTrials.gov

2018-02-13

Endometrial Adenocarcinoma; Endometrial Clear Cell Adenocarcinoma; Endometrial Mixed Adenocarcinoma; Endometrial Mucinous Adenocarcinoma; Endometrial Serous Adenocarcinoma; Endometrial Squamous Cell Carcinoma; Endometrial Transitional Cell Carcinoma; Endometrial Undifferentiated Carcinoma; Recurrent Uterine Corpus Carcinoma

Brivanib Alaninate in Treating Patients With Recurrent or Persistent Endometrial Cancer

ClinicalTrials.gov

2017-11-02

Endometrial Adenocarcinoma; Endometrial Clear Cell Adenocarcinoma; Endometrial Mixed Adenocarcinoma; Endometrial Mucinous Adenocarcinoma; Endometrial Serous Adenocarcinoma; Endometrial Squamous Cell Carcinoma; Endometrial Transitional Cell Carcinoma; Endometrial Undifferentiated Carcinoma; Recurrent Uterine Corpus Carcinoma

A Presynaptic Function of Shank Protein in Drosophila.

PubMed

Wu, Song; Gan, Guangming; Zhang, Zhiping; Sun, Jie; Wang, Qifu; Gao, Zhongbao; Li, Meixiang; Jin, Shan; Huang, Juan; Thomas, Ulrich; Jiang, Yong-Hui; Li, Yan; Tian, Rui; Zhang, Yong Q

2017-11-29

Human genetic studies support that loss-of-function mutations in the SH 3 domain and ank yrin repeat containing family proteins (SHANK1-3), the large synaptic scaffolding proteins enriched at the postsynaptic density of excitatory synapses, are causative for autism spectrum disorder and other neuropsychiatric disorders in humans. To better understand the in vivo functions of Shank and facilitate dissection of neuropathology associated with SHANK mutations in human, we generated multiple mutations in the Shank gene, the only member of the SHANK family in Drosophila melanogaster Both male and female Shank null mutants were fully viable and fertile with no apparent morphological or developmental defects. Expression analysis revealed apparent enrichment of Shank in the neuropils of the CNS. Specifically, Shank coexpressed with another PSD scaffold protein, Homer, in the calyx of mushroom bodies in the brain. Consistent with high expression in mushroom body calyces, Shank mutants show an abnormal calyx structure and reduced olfactory acuity. These morphological and functional phenotypes were fully rescued by pan-neuronal reexpression of Shank, and only partially rescued by presynaptic but no rescue by postsynaptic reexpression of Shank. Our findings thus establish a previously unappreciated presynaptic function of Shank. SIGNIFICANCE STATEMENT Mutations in SHANK family genes are causative for idiopathic autism spectrum disorder. To understand the neural function of Shank, a large scaffolding protein enriched at the postsynaptic densities, we examined the role of Drosophila Shank in synapse development at the peripheral neuromuscular junctions and the central mushroom body calyx. Our results demonstrate that, in addition to its conventional postsynaptic function, Shank also acts presynaptically in synapse development in the brain. This study offers novel insights into the synaptic role of Shank. Copyright © 2017 the authors 0270-6474/17/3711592-13$15.00/0.

Abrogation of E-cadherin-mediated cell-cell contact in mouse embryonic stem cells results in reversible LIF-independent self-renewal.

PubMed

Soncin, Francesca; Mohamet, Lisa; Eckardt, Dominik; Ritson, Sarah; Eastham, Angela M; Bobola, Nicoletta; Russell, Angela; Davies, Steve; Kemler, Rolf; Merry, Catherine L R; Ward, Christopher M

2009-09-01

We have previously demonstrated that differentiation of embryonic stem (ES) cells is associated with downregulation of cell surface E-cadherin. In this study, we assessed the function of E-cadherin in mouse ES cell pluripotency and differentiation. We show that inhibition of E-cadherin-mediated cell-cell contact in ES cells using gene knockout (Ecad(-/-)), RNA interference (EcadRNAi), or a transhomodimerization-inhibiting peptide (CHAVC) results in cellular proliferation and maintenance of an undifferentiated phenotype in fetal bovine serum-supplemented medium in the absence of leukemia inhibitory factor (LIF). Re-expression of E-cadherin in Ecad(-/-), EcadRNAi, and CHAVC-treated ES cells restores cellular dependence to LIF supplementation. Although reversal of the LIF-independent phenotype in Ecad(-/-) ES cells is dependent on the beta-catenin binding domain of E-cadherin, we show that beta-catenin null (betacat(-/-)) ES cells also remain undifferentiated in the absence of LIF. This suggests that LIF-independent self-renewal of Ecad(-/-) ES cells is unlikely to be via beta-catenin signaling. Exposure of Ecad(-/-), EcadRNAi, and CHAVC-treated ES cells to the activin receptor-like kinase inhibitor SB431542 led to differentiation of the cells, which could be prevented by re-expression of E-cadherin. To confirm the role of transforming growth factor beta family signaling in the self-renewal of Ecad(-/-) ES cells, we show that these cells maintain an undifferentiated phenotype when cultured in serum-free medium supplemented with Activin A and Nodal, with fibroblast growth factor 2 required for cellular proliferation. We conclude that transhomodimerization of E-cadherin protein is required for LIF-dependent ES cell self-renewal and that multiple self-renewal signaling networks subsist in ES cells, with activity dependent upon the cellular context.

Apoptotic Cell Clearance in Development.

PubMed

Shklover, Jeny; Levy-Adam, Flonia; Kurant, Estee

2015-01-01

Programmed cell death and its specific form apoptosis play an important role during development of multicellular organisms. They are crucial for morphogenesis and organ sculpting as well as for adjusting cell number in different systems. Removal of apoptotic cells is the last critical step of apoptosis. Apoptotic cells are properly and efficiently recognized and eliminated through phagocytosis, which is performed by professional and nonprofessional phagocytes. Phagocytosis of apoptotic cells or apoptotic cell clearance is a dynamic multistep process, involving interactions between phagocytic receptors and ligands on apoptotic cells, which are highly conserved in evolution. However, this process is extremely redundant in mammals, containing multiple factors playing similar roles in the process. Using model organisms such as Caenorhabditis elegans, Drosophila melanogaster, zebrafish, and mouse permits addressing fundamental questions in developmental cell clearance by a comprehensive approach including powerful genetics and cell biological tools enriched by live imaging. Recent studies in model organisms have enhanced significantly our understanding of the molecular and cellular basis of apoptotic cell clearance during development. Here, we review the current knowledge and illuminate the great potential of the research performed in genetic models, which opens new directions in developmental biology. © 2015 Elsevier Inc. All rights reserved.

[Undifferentiated cutaneous angiosarcoma of the head: identification by the endothelial marker Ulex europaeus agglutinin I].

PubMed

Bork, K; Fries, J; Hoede, N; Korting, G W; Dienes, P

1985-06-01

Cutaneous angiosarcoma of the head is a rare tumor of the elderly and can occur in an undifferentiated form without any clinical or histological signs of the vascular origin of this tumor. In these cases, the tumor can be identified by using endothelial cell markers, such as factor-VIII-related antigen and ulex europaeus agglutinin I, in an immunofluorescence technique or a peroxidase-antiperoxidase method. A 78-year-old patient is described who died within 18 months from such a tumor, which was diagnosed using the endothelial cell marker, ulex europaeus agglutinin I.

In vivo demonstration of cell types in bone that harbor epidermal growth factor receptors

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

Martineau-Doize, B.; Lai, W.H.; Warshawsky, H.

1988-08-01

The binding and internalization of (/sup 125/I)iodoepidermal growth factor (EGF) by bone cells of the rat was demonstrated in situ by quantitative radioautography. Specific binding sites were observed on a cell profile enriched in endocytic components, including lysosome-like structures, a rough endoplasmic reticulum-rich cell profile, and a cell profile that histologically resembles an undifferentiated precursor cell. By the criteria of gel filtration and precipitability by trichloroacetic acid, most of the bound (/sup 125/I)iodo-EGF was considered intact. By morphological criteria none of the cell profiles that bound (/sup 125/I)iodo-EGF corresponded to fully formed osteoclasts or osteoblasts. The endocytic cell was foundmore » in the epiphyseal plate between the invading capillary and the transverse and longitudinal cartilage septa as well as near osteoclasts in the zone of mixed spicules. The rough endoplasmic reticulum-rich cell was present in vacated chondrocyte lacunae of the epiphyseal plate close to the metaphysis, and the poorly differentiated cell was observed between the mixed spicules of the metaphysis. Similar cell types were also found in the alveolar bone surrounding the incisors. These cells may be the origin of established bone cell lines that harbor high concentrations of EGF receptors and may also be responsible for the humoral hypercalcemia in response to the reported actions of injected EGF or transforming growth factor-alpha as well as that of malignancy.« less

Down regulation of ITGA4 and ITGA5 genes after formation of 3D spherules by human Wharton's jelly stem cells (hWJSCs).

PubMed

Mostafavi-Pour, Zohreh; Ashrafi, Mohammad Reza; Talaei-Khozani, Tahereh

2018-06-01

Human Wharton's jelly mesenchymal stem cells (hWJSCs) are multipotent stem cells that could be aggregated into 3D spherules. ITGA4 and ITGA5 genes encode α4 and α5 subunits of integrins, respectively. In this study, we analyzed expression levels of ITGA4 and ITGA5 gene mRNAs in undifferentiated and 3D spherules forming hWJSCs in order to determine their expression pattern for possible future treatment of cancer cells in a co-culture fashion. For the purpose of obtaining hWJSCs, umbilical cords were collected from patients with caesarian section at full term delivery. The cells were then characterized according to cell surface markers using flow cytometry. Furthermore pluripotency of the obtained cells was verified. Subsequently the cells were aggregated in 3D spherules using hanging drop cultures. Expression levels of ITGA4 and ITGA5 gene mRNAs were determined by RT-PCR and Real time PCR, both in the initial undifferentiated cells and those aggregated in the spherules. The obtained hWJSCs demonstrated pluripotency, differentiating to adipogenic and osteogenic cells. They also expressed mesenchymal stem cell surface markers. Following the aggregation of these cells and formation of 3D spherules, mRNA expression levels of both genes were significantly reduced (P < 0.05) compared with the initial undifferentiated state. The results of this study demonstrated that aggregation of hWJSCs into spherules alters their expression of ITGA4 and ITGA5. The implications of such an alteration would require further research.

Transplantation of neurons derived from human iPS cells cultured on collagen matrix into guinea-pig cochleae.

PubMed

Ishikawa, Masaaki; Ohnishi, Hiroe; Skerleva, Desislava; Sakamoto, Tatsunori; Yamamoto, Norio; Hotta, Akitsu; Ito, Juichi; Nakagawa, Takayuki

2017-06-01

The present study examined the efficacy of a neural induction method for human induced pluripotent stem (iPS) cells to eliminate undifferentiated cells and to determine the feasibility of transplanting neurally induced cells into guinea-pig cochleae for replacement of spiral ganglion neurons (SGNs). A stepwise method for differentiation of human iPS cells into neurons was used. First, a neural induction method was established on Matrigel-coated plates; characteristics of cell populations at each differentiation step were assessed. Second, neural stem cells were differentiated into neurons on a three-dimensional (3D) collagen matrix, using the same protocol of culture on Matrigel-coated plates; neuron subtypes in differentiated cells on a 3D collagen matrix were examined. Then, human iPS cell-derived neurons cultured on a 3D collagen matrix were transplanted into intact guinea-pig cochleae, followed by histological analysis. In vitro analyses revealed successful induction of neural stem cells from human iPS cells, with no retention of undifferentiated cells expressing OCT3/4. After the neural differentiation of neural stem cells, approximately 70% of cells expressed a neuronal marker, 90% of which were positive for vesicular glutamate transporter 1 (VGLUT1). The expression pattern of neuron subtypes in differentiated cells on a 3D collagen matrix was identical to that of the differentiated cells on Matrigel-coated plates. In addition, the survival of transplant-derived neurons was achieved when inflammatory responses were appropriately controlled. Our preparation method for human iPS cell-derived neurons efficiently eliminated undifferentiated cells and contributed to the settlement of transplant-derived neurons expressing VGLUT1 in guinea-pig cochleae. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Micro-RNA-128 (miRNA-128) down-regulation in glioblastoma targets ARP5 (ANGPTL6), Bmi-1 and E2F-3a, key regulators of brain cell proliferation.

PubMed

Cui, J G; Zhao, Y; Sethi, P; Li, Y Y; Mahta, A; Culicchia, F; Lukiw, W J

2010-07-01

High density micro-RNA (miRNA) arrays, fluorescent-reporter miRNA assay and Northern miRNA dot-blot analysis show that a brain-enriched miRNA-128 is significantly down-regulated in glioblastoma multiforme (GBM) and in GBM cell lines when compared to age-matched controls. The down-regulation of miRNA-128 was found to inversely correlate with WHO tumor grade. Three bioinformatics-verified miRNA-128 targets, angiopoietin-related growth factor protein 5 (ARP5; ANGPTL6), a transcription suppressor that promotes stem cell renewal and inhibits the expression of known tumor suppressor genes involved in senescence and differentiation, Bmi-1, and a transcription factor critical for the control of cell-cycle progression, E2F-3a, were found to be up-regulated. Addition of exogenous miRNA-128 to CRL-1690 and CRL-2610 GBM cell lines (a) restored 'homeostatic' ARP5 (ANGPTL6), Bmi-1 and E2F-3a expression, and (b) significantly decreased the proliferation of CRL-1690 and CRL-2610 cell lines. Our data suggests that down-regulation of miRNA-128 may contribute to glioma and GBM, in part, by coordinately up-regulating ARP5 (ANGPTL6), Bmi-1 and E2F-3a, resulting in the proliferation of undifferentiated GBM cells.

Sequoia establishes tip-cell number in Drosophila trachea by regulating FGF levels.

PubMed

Araújo, Sofia J; Casanova, Jordi

2011-07-15

Competition and determination of leading and trailing cells during collective cell migration is a widespread phenomenon in development, wound healing and tumour invasion. Here, we analyse this issue during in vivo ganglionic branch cell migration in the Drosophila tracheal system. We identify Sequoia (Seq) as a negative transcriptional regulator of Branchless (Bnl), a Drosophila FGF homologue, and observe that modulation of Bnl levels determines how many cells will lead this migrating cluster, regardless of Notch lateral inhibition. Our results show that becoming a tip cell does not prevent others in the branch taking the same position, suggesting that leader choice does not depend only on sensing relative amounts of FGF receptor activity.

The Drosophila Sp8 transcription factor Buttonhead prevents premature differentiation of intermediate neural progenitors

PubMed Central

Xie, Yonggang; Li, Xiaosu; Zhang, Xian; Mei, Shaolin; Li, Hongyu; Urso, Andreacarola; Zhu, Sijun

2014-01-01

Intermediate neural progenitor cells (INPs) need to avoid differentiation and cell cycle exit while maintaining restricted developmental potential, but mechanisms preventing differentiation and cell cycle exit of INPs are not well understood. In this study, we report that the Drosophila homolog of mammalian Sp8 transcription factor Buttonhead (Btd) prevents premature differentiation and cell cycle exit of INPs in Drosophila larval type II neuroblast (NB) lineages. We show that the loss of Btd leads to elimination of mature INPs due to premature differentiation of INPs into terminally dividing ganglion mother cells. We provide evidence to demonstrate that Btd prevents the premature differentiation by suppressing the expression of the homeodomain protein Prospero in immature INPs. We further show that Btd functions cooperatively with the Ets transcription factor Pointed P1 to promote the generation of INPs. Thus, our work reveals a critical mechanism that prevents premature differentiation and cell cycle exit of Drosophila INPs. DOI: http://dx.doi.org/10.7554/eLife.03596.001 PMID:25285448

PRMT5 is essential for the maintenance of chondrogenic progenitor cells in the limb bud

PubMed Central

Norrie, Jacqueline L.; Li, Qiang; Co, Swanie; Huang, Bau-Lin; Ding, Ding; Uy, Jann C.; Ji, Zhicheng; Mackem, Susan; Bedford, Mark T.; Galli, Antonella; Ji, Hongkai

2016-01-01

During embryonic development, undifferentiated progenitor cells balance the generation of additional progenitor cells with differentiation. Within the developing limb, cartilage cells differentiate from mesodermal progenitors in an ordered process that results in the specification of the correct number of appropriately sized skeletal elements. The internal pathways by which these cells maintain an undifferentiated state while preserving their capacity to differentiate is unknown. Here, we report that the arginine methyltransferase PRMT5 has a crucial role in maintaining progenitor cells. Mouse embryonic buds lacking PRMT5 have severely truncated bones with wispy digits lacking joints. This novel phenotype is caused by widespread cell death that includes mesodermal progenitor cells that have begun to precociously differentiate into cartilage cells. We propose that PRMT5 maintains progenitor cells through its regulation of Bmp4. Intriguingly, adult and embryonic stem cells also require PRMT5 for maintaining pluripotency, suggesting that similar mechanisms might regulate lineage-restricted progenitor cells during organogenesis. PMID:27827819

PRMT5 is essential for the maintenance of chondrogenic progenitor cells in the limb bud.

PubMed

Norrie, Jacqueline L; Li, Qiang; Co, Swanie; Huang, Bau-Lin; Ding, Ding; Uy, Jann C; Ji, Zhicheng; Mackem, Susan; Bedford, Mark T; Galli, Antonella; Ji, Hongkai; Vokes, Steven A

2016-12-15

During embryonic development, undifferentiated progenitor cells balance the generation of additional progenitor cells with differentiation. Within the developing limb, cartilage cells differentiate from mesodermal progenitors in an ordered process that results in the specification of the correct number of appropriately sized skeletal elements. The internal pathways by which these cells maintain an undifferentiated state while preserving their capacity to differentiate is unknown. Here, we report that the arginine methyltransferase PRMT5 has a crucial role in maintaining progenitor cells. Mouse embryonic buds lacking PRMT5 have severely truncated bones with wispy digits lacking joints. This novel phenotype is caused by widespread cell death that includes mesodermal progenitor cells that have begun to precociously differentiate into cartilage cells. We propose that PRMT5 maintains progenitor cells through its regulation of Bmp4 Intriguingly, adult and embryonic stem cells also require PRMT5 for maintaining pluripotency, suggesting that similar mechanisms might regulate lineage-restricted progenitor cells during organogenesis. © 2016. Published by The Company of Biologists Ltd.

Human neuroblastoma SH-SY5Y cells show increased resistance to hyperthermic stress after differentiation, associated with elevated levels of Hsp72.

PubMed

Cheng, Lesley; Smith, Danielle J; Anderson, Robin L; Nagley, Phillip

2011-01-01

Terminally differentiated neurones in the central nervous system need to be protected from stress. We ask here whether differentiation of progenitor cells to neurones is accompanied by up-regulation of Hsp72, with acquisition of enhanced thermotolerance. Human neuroblastoma SH-SY5Y cells were propagated in an undifferentiated form and subsequently differentiated into neurone-like cells. Thermotolerance tests were carried out by exposure of cells to various temperatures, monitoring nuclear morphology as index of cell death. Abundance of Hsp72 was measured in cell lysates by western immunoblotting. The differentiation of SH-SY5Y cells was accompanied by increased expression of Hsp72. Further, in both cell states, exposure to mild hyperthermic stress (43°C for 30 min) increased Hsp72 expression. After differentiation, SH-SY5Y cells were more resistant to hyperthermic stress compared to their undifferentiated state, correlating with levels of Hsp72. Stable exogenous expression of Hsp72 in SH-SY5Y cells (transfected line 5YHSP72.1, containing mildly elevated levels of Hsp72), led to enhanced resistance to hyperthermic stress. Hsp72 was found to be inducible in undifferentiated 5YHSP72.1 cells; such heat-treated cells displayed enhanced thermotolerance. Treatment of cells with KNK437, a suppressor of Hsp72 induction, resulted in acute thermosensitisation of all cell types tested here. Hsp72 has a major role in the enhanced hyperthermic resistance acquired during neuronal differentiation of SH-SY5Y cells. These findings model the requirement in intact organisms for highly differentiated neurones to be specially protected against thermal stress.

Single molecule transcription factor dynamics in the syncytial Drosophila embryo

NASA Astrophysics Data System (ADS)

Darzacq, Xavier

During early development in the Drosophila embryo, cell fates are determined over the course of just 2 hours with exquisite spatio-temoral precision. One of the key regulators of this process is the transcription factor Bicoid which forms a concentration gradient across the long axis of the embryo. Although Bicoids' primary role is activation at the anterior, where concentrations are highest, it is also known to play a role in the posterior where there are only 100s of molecules per nucleus. Understanding how Bicoid can find its target at such low concentrations has remained intractable, largely due to the inability to perform single molecule imaging in the context of the developing embryo. Here we use lattice light sheet microscopy to overcome the technical barriers of sample thickness and auto-fluorescence to characterize the single molecule dynamics of Bicoid. We find that off-rates do not vary across the embryo and that instead the on-rates are modulated through the formation of clusters that enrich local concentration. This data is contrary to the current concentration dependent model of Bicoid function since local concentration within the nucleus is now a regulated parameter and suggests a previously unknown mechanism for regulation at extremely low concentrations.

Graf regulates hematopoiesis through GEEC endocytosis of EGFR.

PubMed

Kim, Sungdae; Nahm, Minyeop; Kim, Najin; Kwon, Yumi; Kim, Joohyung; Choi, Sukwoo; Choi, Eun Young; Shim, Jiwon; Lee, Cheolju; Lee, Seungbok

2017-11-15

GTPase regulator associated with focal adhesion kinase 1 (GRAF1) is an essential component of the GPI-enriched endocytic compartment (GEEC) endocytosis pathway. Mutations in the human GRAF1 gene are associated with acute myeloid leukemia, but its normal role in myeloid cell development remains unclear. We show that Graf, the Drosophila ortholog of GRAF1, is expressed and specifically localizes to GEEC endocytic membranes in macrophage-like plasmatocytes. We also find that loss of Graf impairs GEEC endocytosis, enhances EGFR signaling and induces a plasmatocyte overproliferation phenotype that requires the EGFR signaling cascade. Mechanistically, Graf-dependent GEEC endocytosis serves as a major route for EGFR internalization at high, but not low, doses of the predominant Drosophila EGFR ligand Spitz (Spi), and is indispensable for efficient EGFR degradation and signal attenuation. Finally, Graf interacts directly with EGFR in a receptor ubiquitylation-dependent manner, suggesting a mechanism by which Graf promotes GEEC endocytosis of EGFR at high Spi. Based on our findings, we propose a model in which Graf functions to downregulate EGFR signaling by facilitating Spi-induced receptor internalization through GEEC endocytosis, thereby restraining plasmatocyte proliferation. © 2017. Published by The Company of Biologists Ltd.

miR-34 Modulates Innate Immunity and Ecdysone Signaling in Drosophila

PubMed Central

Xiong, Xiao-Peng; Chang, Kung-Yen; Ren, Xingjie; Ni, Jian-Quan; Rana, Tariq M.; Zhou, Rui

2016-01-01

microRNAs are endogenous small regulatory RNAs that modulate myriad biological processes by repressing target gene expression in a sequence-specific manner. Here we show that the conserved miRNA miR-34 regulates innate immunity and ecdysone signaling in Drosophila. miR-34 over-expression activates antibacterial innate immunity signaling both in cultured cells and in vivo, and flies over-expressing miR-34 display improved survival and pathogen clearance upon Gram-negative bacterial infection; whereas miR-34 knockout animals are defective in antibacterial defense. In particular, miR-34 achieves its immune-stimulatory function, at least in part, by repressing the two novel target genes Dlg1 and Eip75B. In addition, our study reveals a mutual repression between miR-34 expression and ecdysone signaling, and identifies miR-34 as a node in the intricate interplay between ecdysone signaling and innate immunity. Lastly, we identify cis-regulatory genomic elements and trans-acting transcription factors required for optimal ecdysone-mediated repression of miR-34. Taken together, our study enriches the repertoire of immune-modulating miRNAs in animals, and provides new insights into the interplay between steroid hormone signaling and innate immunity. PMID:27893816

miR-34 Modulates Innate Immunity and Ecdysone Signaling in Drosophila.

PubMed

Xiong, Xiao-Peng; Kurthkoti, Krishna; Chang, Kung-Yen; Li, Jian-Liang; Ren, Xingjie; Ni, Jian-Quan; Rana, Tariq M; Zhou, Rui

2016-11-01

microRNAs are endogenous small regulatory RNAs that modulate myriad biological processes by repressing target gene expression in a sequence-specific manner. Here we show that the conserved miRNA miR-34 regulates innate immunity and ecdysone signaling in Drosophila. miR-34 over-expression activates antibacterial innate immunity signaling both in cultured cells and in vivo, and flies over-expressing miR-34 display improved survival and pathogen clearance upon Gram-negative bacterial infection; whereas miR-34 knockout animals are defective in antibacterial defense. In particular, miR-34 achieves its immune-stimulatory function, at least in part, by repressing the two novel target genes Dlg1 and Eip75B. In addition, our study reveals a mutual repression between miR-34 expression and ecdysone signaling, and identifies miR-34 as a node in the intricate interplay between ecdysone signaling and innate immunity. Lastly, we identify cis-regulatory genomic elements and trans-acting transcription factors required for optimal ecdysone-mediated repression of miR-34. Taken together, our study enriches the repertoire of immune-modulating miRNAs in animals, and provides new insights into the interplay between steroid hormone signaling and innate immunity.

A novel, tissue-specific, Drosophila homeobox gene.

PubMed

Barad, M; Jack, T; Chadwick, R; McGinnis, W

1988-07-01

The homeobox gene family of Drosophila appears to control a variety of position-specific patterning decisions during embryonic and imaginal development. Most of these patterning decisions determine groups of cells on the anterior-posterior axis of the Drosophila germ band. We have isolated a novel homeobox gene from Drosophila, designated H2.0. H2.0 has the most diverged homeobox so far characterized in metazoa, and, in contrast to all previously isolated homeobox genes, H2.0 exhibits a tissue-specific pattern of expression. The cells that accumulate transcripts for this novel gene correspond to the visceral musculature and its anlagen.

[Role of CD2-associated protein in podocyte differentiation.].

PubMed

Jiang, Hua-Jun; Chang, Ying; Zhu, Zhong-Hua; Liu, Jian-She; Deng, An-Guo; Zhang, Chun

2008-02-25

To study the cellular changes and the potential role of CD2-associated protein (CD2AP) in podocyte differentiation, conditionally immortalized murine podocyte cell line was cultured in RPMI 1640 medium under permissive condition at 33 °C. After transfection with CD2AP small interfering RNA (siRNA) the cells were shifted to non-permissive condition at 37 °C. Simultaneously, untransfected cells were taken as differentiation control. The podocyte proliferation rate was determined by MTT method. The expressions of CD2AP, WT1, synaptopodin and nephrin mRNAs were examined by RT-PCR. CD2AP, WT1 and nephrin protein expressions were examined by Western blot. The distribution of CD2AP, nephrin, F-actin and tubulin in differentiated and undifferentiated podocytes was detected by laser scanning confocal microscopy. The results showed: (1) CD2AP, WT1 and nephrin were stably expressed in differentiated and undifferentiated podocytes while synaptopodin was only expressed in differentiated podocytes. (2) CD2AP and nephrin mRNA and protein expressions were up-regulated during podocyte differentiation (P<0.05). (3) CD2AP and tubulin were distributed in the cytoplasm and perinulcear region in undifferentiated podocytes, and F-actin was predominantly localized to a cortical belt and paralleled to the cell axis. Under differentiation condition, CD2AP distribution profile was presented as peripheral accumulation, tubulin took on fascicular style and F-actin extended into foot processes in podocytes. CD2AP colocalized with nephrin and F-actin in undifferentiated podocytes. (4) After transfection with CD2AP siRNA, the expression of CD2AP was partially inhibited and cell growth was arrested; Synaptopodin, the differentiation podocyte marker, was apparently down-regulated; The differentiation of podocytes was delayed. The results demonstrate that podocyte differentiation is accompanied by cytoskeleton rearrangement and cell morphology change. CD2AP might play an essential role in podocyte differentiation.

Undifferentiated embryonic cell transcription factor 1 (UTF1) and deleted in azoospermia-like (DAZL) expression in the testes of donkeys.

PubMed

Lee, Y S; Jung, H J; Yoon, M J

2017-04-01

Putative markers for each specific germ cell stage can be a useful tool to study the fate and functions of these cells. Undifferentiated embryonic cell transcription factor 1 (UTF1) is a putative marker for undifferentiated spermatogonia in humans, rats and horses. The deleted in azoospermia-like (DAZL) protein is also expressed by differentiated spermatogonia and primary spermatocytes in several species. However, whether the expression patterns of these molecular markers are identical and applicable to donkeys remains to be elucidated. The objective of this study was to investigate the expression patterns of UTF1 and DAZL in donkey testicular tissue, using immunohistochemistry (IHC). Testicular samples were collected from routine field castration of donkeys in Korea. The reproductive stages (pre- or post-puberty) of the testes were determined from the morphological characteristics of cross-sections of the seminiferous tubules. For IHC, the UTF1 and DAZL primary antibodies were diluted at 1:100 and 1:200, respectively. The immunolabelling revealed that UTF1 was expressed in approximately 50% of spermatogonia in the pre-pubertal stage, whereas its expression was limited to an early subset of spermatogonia in the post-pubertal stage. DAZL was expressed in some, but not all, spermatogonia in the pre-pubertal spermatogonia, and interestingly, its expression was also observed in spermatogonia and primary spermatocytes in the post-pubertal stage. Co-immunolabelling of the germ cells with both UTF1 and DAZL revealed three types of protein expression patterns at both reproductive stages, namely UTF1 only, DAZL only and both UTF1 and DAZL. These protein molecules were not expressed in Sertoli and Leydig cells. In conclusion, a co-immunolabelling system with UTF1 and DAZL antibodies may be used to identify undifferentiated (UTF1 only), differentiating (UTF1 and DAZL), and differentiated spermatogonia (DAZL only) in donkey testes. © 2017 Blackwell Verlag GmbH.

Function of Lipid Storage Droplet 1 (Lsd1) in Wing Development of Drosophila melanogaster.

PubMed

Men, Tran Thanh; Binh, Tran Duy; Yamaguchi, Masamitsu; Huy, Nguyen Tien; Kamei, Kaeko

2016-04-29

Perilipins are evolutionarily conserved from Drosophila to humans, the lipid storage droplet 1 (Lsd1) is a Drosophila homolog of human perilipin 1. The function of Lsd1 as a regulator of lipolysis in Drosophila has been demonstrated, as the Lsd1 mutant causes an increase of lipid droplet size. However, the functions of this gene during development are still under investigation. In order to determine the function of Lsd1 during development, Lsd1 was knocked down in Drosophila using the GAL4-UAS system. Selective knockdown of Lsd1 in the dorsal wing disc caused an atrophied wing phenotype. The generation of reactive oxygen species in the wing pouch compartment of the Lsd1-knockdown flies was significantly higher than in the control. Immunostaining with caspase-3 antibody revealed a greater number of apoptotic cells in Lsd1-knockdown wing discs than in the control. Cell death by autophagy was also induced in the knockdown flies. Moreover, cells deprived of Lsd1 showed mitochondrial expansion and decreased ATP levels. These results strongly suggest that knockdown of Lsd1 induces mitochondrial stress and the production of reactive oxygen species that result in cell death, via apoptosis and the autophagy pathway. These results highlight the roles of Drosophila Lsd1 during wing development.

Ectopic bone regeneration by human bone marrow mononucleated cells, undifferentiated and osteogenically differentiated bone marrow mesenchymal stem cells in beta-tricalcium phosphate scaffolds.

PubMed

Ye, Xinhai; Yin, Xiaofan; Yang, Dawei; Tan, Jian; Liu, Guangpeng

2012-07-01

Tissue engineering approaches using the combination of porous ceramics and bone marrow mesenchymal stem cells (BMSCs) represent a promising bone substitute for repairing large bone defects. Nevertheless, optimal conditions for constructing tissue-engineered bone have yet to be determined. It remains unclear if transplantation of predifferentiated BMSCs is superior to undifferentiated BMSCs or freshly isolated bone marrow mononucleated cells (BMNCs) in terms of new bone formation in vivo. The aim of this study was to investigate the effect of in vitro osteogenic differentiation (β-glycerophosphate, dexamethasone, and l-ascorbic acid) of human BMSCs on the capability to form tissue-engineered bone in unloaded conditions after subcutaneous implantation in nude mice. After isolation from human bone marrow aspirates, BMNCs were divided into three parts: one part was seeded onto porous beta-tricalcium phosphate ceramics immediately and transplanted in a heterotopic nude mice model; two parts were expanded in vitro to passage 2 before cell seeding and in vivo transplantation, either under osteogenic conditions or not. Animals were sacrificed for micro-CT and histological evaluation at 4, 8, 12, 16, and 20 weeks postimplantation. The results showed that BMSCs differentiated into osteo-progenitor cells after induction, as evidenced by the altered cell morphology and elevated alkaline phosphatase activity and calcium deposition, but their clonogenicity, proliferating rate, and seeding efficacy were not significantly affected by osteogenic differentiation, compared with undifferentiated cells. Extensive new bone formed in the pores of all the scaffolds seeded with predifferentiated BMSCs at 4 weeks after implantation, and maintained for 20 weeks. On the contrary, scaffolds containing undifferentiated BMSCs revealed limited bone formation only in 1 out of 6 cases at 8 weeks, and maintained for 4 weeks. For scaffolds with BMNCs, woven bone was observed sporadically only in one case at 8 weeks. Overall, this study suggests that ectopic osteogenesis of cell/scaffold composites is more dependent on the in vitro expansion condition, and osteo-differentiated BMSCs hold the highest potential concerning in vivo bone regeneration.

Embryonic multipotent progenitors remodel the Drosophila airways during metamorphosis

PubMed Central

Pitsouli, Chrysoula; Perrimon, Norbert

2010-01-01

Adult structures in holometabolous insects such as Drosophila are generated by groups of imaginal cells dedicated to the formation of different organs. Imaginal cells are specified in the embryo and remain quiescent until the larval stages, when they proliferate and differentiate to form organs. The Drosophila tracheal system is extensively remodeled during metamorphosis by a small number of airway progenitors. Among these, the spiracular branch tracheoblasts are responsible for the generation of the pupal and adult abdominal airways. To understand the coordination of proliferation and differentiation during organogenesis of tubular organs, we analyzed the remodeling of Drosophila airways during metamorphosis. We show that the embryonic spiracular branch tracheoblasts are multipotent cells that express the homeobox transcription factor Cut, which is necessary for their survival and normal development. They give rise to three distinct cell populations at the end of larval development, which generate the adult tracheal tubes, the spiracle and the epidermis surrounding the spiracle. Our study establishes the series of events that lead to the formation of an adult tubular structure in Drosophila. PMID:20940225

Carboplatin and Paclitaxel With or Without Bevacizumab in Treating Patients With Stage III or Stage IV Ovarian Epithelial, Primary Peritoneal, or Fallopian Tube Cancer

ClinicalTrials.gov

2017-10-23

Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Adenocarcinoma; Fallopian Tube Mucinous Adenocarcinoma; Fallopian Tube Serous Adenocarcinoma; Fallopian Tube Transitional Cell Carcinoma; Malignant Ovarian Mixed Epithelial Tumor; Ovarian Brenner Tumor; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Adenocarcinoma; Ovarian Serous Adenocarcinoma; Ovarian Transitional Cell Carcinoma; Primary Peritoneal Serous Adenocarcinoma; Stage IIIA Fallopian Tube Cancer; Stage IIIA Ovarian Cancer; Stage IIIA Primary Peritoneal Cancer; Stage IIIB Fallopian Tube Cancer; Stage IIIB Ovarian Cancer; Stage IIIB Primary Peritoneal Cancer; Stage IIIC Fallopian Tube Cancer; Stage IIIC Ovarian Cancer; Stage IIIC Primary Peritoneal Cancer; Stage IV Fallopian Tube Cancer; Stage IV Ovarian Cancer; Stage IV Primary Peritoneal Cancer; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

GATA simple sequence repeats function as enhancer blocker boundaries.

PubMed

Kumar, Ram P; Krishnan, Jaya; Pratap Singh, Narendra; Singh, Lalji; Mishra, Rakesh K

2013-01-01

Simple sequence repeats (SSRs) account for ~3% of the human genome, but their functional significance still remains unclear. One of the prominent SSRs the GATA tetranucleotide repeat has preferentially accumulated in complex organisms. GATA repeats are particularly enriched on the human Y chromosome, and their non-random distribution and exclusive association with genes expressed during early development indicate their role in coordinated gene regulation. Here we show that GATA repeats have enhancer blocker activity in Drosophila and human cells. This enhancer blocker activity is seen in transgenic as well as native context of the enhancers at various developmental stages. These findings ascribe functional significance to SSRs and offer an explanation as to why SSRs, especially GATA, may have accumulated in complex organisms.

Long Glucocorticoid-induced Leucine Zipper (L-GILZ) Protein Interacts with Ras Protein Pathway and Contributes to Spermatogenesis Control*

PubMed Central

Bruscoli, Stefano; Velardi, Enrico; Di Sante, Moises; Bereshchenko, Oxana; Venanzi, Alessandra; Coppo, Maddalena; Berno, Valeria; Mameli, Maria Grazia; Colella, Renato; Cavaliere, Antonio; Riccardi, Carlo

2012-01-01

Correct function of spermatogonia is critical for the maintenance of spermatogenesis throughout life, but the cellular pathways regulating undifferentiated spermatogonia proliferation, differentiation, and survival are only partially known. We show here that long glucocorticoid-induced leucine zipper (L-GILZ) is highly expressed in spermatogonia and primary spermatocytes and controls spermatogenesis. Gilz deficiency in knock-out (gilz KO) mice leads to a complete loss of germ cell lineage within first cycles of spermatogenesis, resulting in male sterility. Spermatogenesis failure is intrinsic to germ cells and is associated with increased proliferation and aberrant differentiation of undifferentiated spermatogonia and with hyperactivity of Ras signaling pathway as indicated by an increase of ERK and Akt phosphorylation. Spermatogonia differentiation does not proceed beyond the prophase of the first meiotic division due to massive apoptosis associated with accumulation of unrepaired chromosomal damage. These results identify L-GILZ as a novel important factor for undifferentiated spermatogonia function and spermatogenesis. PMID:22110132

An evolutionarily conserved gene family encodes proton-selective ion channels.

PubMed

Tu, Yu-Hsiang; Cooper, Alexander J; Teng, Bochuan; Chang, Rui B; Artiga, Daniel J; Turner, Heather N; Mulhall, Eric M; Ye, Wenlei; Smith, Andrew D; Liman, Emily R

2018-03-02

Ion channels form the basis for cellular electrical signaling. Despite the scores of genetically identified ion channels selective for other monatomic ions, only one type of proton-selective ion channel has been found in eukaryotic cells. By comparative transcriptome analysis of mouse taste receptor cells, we identified Otopetrin1 (OTOP1), a protein required for development of gravity-sensing otoconia in the vestibular system, as forming a proton-selective ion channel. We found that murine OTOP1 is enriched in acid-detecting taste receptor cells and is required for their zinc-sensitive proton conductance. Two related murine genes, Otop2 and Otop3 , and a Drosophila ortholog also encode proton channels. Evolutionary conservation of the gene family and its widespread tissue distribution suggest a broad role for proton channels in physiology and pathophysiology. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

The role of ARK in stress-induced apoptosis in Drosophila cells

PubMed Central

Zimmermann, Katja C.; Ricci, Jean-Ehrland; Droin, Nathalie M.; Green, Douglas R.

2002-01-01

The molecular mechanisms of apoptosis are highly conserved throughout evolution. The homologs of genes essential for apoptosis in Caenorhabditis elegans and Drosophila melanogaster have been shown to be important for apoptosis in mammalian systems. Although a homologue for CED-4/apoptotic protease-activating factor (Apaf)-1 has been described in Drosophila, its exact function and the role of the mitochondrial pathway in its activation remain unclear. Here, we used the technique of RNA interference to dissect apoptotic signaling pathways in Drosophila cells. Inhibition of the Drosophila CED-4/Apaf-1–related killer (ARK) homologue resulted in pronounced inhibition of stress-induced apoptosis, whereas loss of ARK did not protect the cells from Reaper- or Grim-induced cell death. Reduction of DIAP1 induced rapid apoptosis in these cells, whereas the inhibition of DIAP2 expression did not but resulted in increased sensitivity to stress-induced apoptosis; apoptosis in both cases was prevented by inhibition of ARK expression. Cells in which cytochrome c expression was decreased underwent apoptosis induced by stress stimuli, Reaper or Grim. These results demonstrate the central role of ARK in stress-induced apoptosis, which appears to act independently of cytochrome c. Apoptosis induced by Reaper or Grim can proceed via a distinct pathway, independent of ARK. PMID:11901172

Nintedanib in Treating Patients With Recurrent or Persistent Endometrial Cancer

ClinicalTrials.gov

2017-09-08

Endometrial Adenocarcinoma; Endometrial Clear Cell Adenocarcinoma; Endometrial Mucinous Adenocarcinoma; Endometrial Serous Adenocarcinoma; Endometrial Squamous Cell Carcinoma; Endometrial Transitional Cell Carcinoma; Endometrial Undifferentiated Carcinoma; Malignant Uterine Corpus Mixed Epithelial and Mesenchymal Neoplasm; Recurrent Uterine Corpus Carcinoma

Imaging cell competition in Drosophila imaginal discs.

PubMed

Ohsawa, Shizue; Sugimura, Kaoru; Takino, Kyoko; Igaki, Tatsushi

2012-01-01

Cell competition is a process in which cells with higher fitness ("winners") survive and proliferate at the expense of less fit neighbors ("losers"). It has been suggested that cell competition is involved in a variety of biological processes such as organ size control, tissue homeostasis, cancer progression, and the maintenance of stem cell population. By advent of a genetic mosaic technique, which enables to generate fluorescently marked somatic clones in Drosophila imaginal discs, recent studies have presented some aspects of molecular mechanisms underlying cell competition. Now, with a live-imaging technique using ex vivo-cultured imaginal discs, we can dissect the spatiotemporal nature of competitive cell behaviors within multicellular communities. Here, we describe procedures and tips for live imaging of cell competition in Drosophila imaginal discs. Copyright © 2012 Elsevier Inc. All rights reserved.

TGFbeta receptor saxophone non-autonomously regulates germline proliferation in a Smox/dSmad2-dependent manner in Drosophila testis.

PubMed

Li, Chun-Yan; Guo, Zheng; Wang, Zhaohui

2007-09-01

Elucidating the regulatory mechanism of cell proliferation is central to the understanding of cancer development or organ size control. Drosophila spermatogenesis provides an excellent model to study cell proliferation since the germline cells mitotically amplify in a precise manner. However, the underlying molecular mechanism remains elusive. Germ cells derived from each gonialblast develop synchronously as one unit encapsulated by two somatic support cells (called cyst cells). Components of TGFbeta pathway have previously been found to restrict germ cell proliferation via their functions in cyst cells. Here we report that saxophone (sax), a TGFbeta type I receptor, is required in somatic cells to prevent the mitotically dividing spermatogonia from over-amplifying. Using various approaches, we demonstrate that Mad (Mothers against Dpp), a receptor-Smad usually associated with Sax-mediated TGFbeta/BMP signaling, is dispensable in this process. Instead, Smox (Smad on X, Drosophila Smad2), the other receptor-Smad formerly characterized in TGFbeta/activin signaling, is necessary for the precise mitotic divisions of spermatogonia. Furthermore, over-expressing Smox in cyst cells can partially rescue the proliferation phenotype induced by sax mutation. We propose that Smox acts downstream of Sax to prevent spermatogonial over-proliferation in Drosophila.

A novel muscle LIM-only protein is generated from the paxillin gene locus in Drosophila.

PubMed

Yagi, R; Ishimaru, S; Yano, H; Gaul, U; Hanafusa, H; Sabe, H

2001-09-01

Paxillin is a protein containing four LIM domains, and functions in integrin signaling. We report here that two transcripts are generated from the paxillin gene locus in Drosophila; one encodes a protein homolog of the vertebrate Paxillin (DPxn37), and the other a protein with only three LIM domains, partly encoded by its own specific exon (PDLP). At the myotendinous junctions of Drosophila embryos where integrins play important roles, both DPxn37 and PDLP are highly expressed with different patterns; DPxn37 is predominantly concentrated at the center of the junctions, whereas PDLP is highly enriched at neighboring sides of the junction centers, primarily expressed in the mesodermal myotubes. Northern blot analysis revealed that DPxn37 is ubiquitously expressed throughout the life cycle, whereas PDLP expression exhibits a biphasic pattern during development, largely concomitant with muscle generation and remodeling. Our results collectively reveal that a unique system exists in Drosophila for the generation of a novel type of LIM-only protein, highly expressed in the embryonic musculature, largely utilizing the Paxillin LIM domains.

Gene expression profile change and growth inhibition in Drosophila larvae treated with azadirachtin.

PubMed

Lai, Duo; Jin, Xiaoyong; Wang, Hao; Yuan, Mei; Xu, Hanhong

2014-09-20

Azadirachtin is a botanical insecticide that affects various biological processes. The effects of azadirachtin on the digital gene expression profile and growth inhibition in Drosophila larvae have not been investigated. In this study, we applied high-throughput sequencing technology to detect the differentially expressed genes of Drosophila larvae regulated by azadirachtin. A total of 15,322 genes were detected, and 28 genes were found to be significantly regulated by azadirachtin. Biological process and pathway analysis showed that azadirachtin affected starch and sucrose metabolism, defense response, signal transduction, instar larval or pupal development, and chemosensory behavior processes. The genes regulated by azadirachtin were mainly enriched in starch and sucrose metabolism. This study provided a general digital gene expression profile of dysregulated genes in response to azadirachtin and showed that azadirachtin provoked potent growth inhibitory effects in Drosophila larvae by regulating the genes of cuticular protein, amylase, and odorant-binding protein. Finally, we propose a potential mechanism underlying the dysregulation of the insulin/insulin-like growth factor signaling pathway by azadirachtin. Copyright © 2014 Elsevier B.V. All rights reserved.

Niche players

PubMed Central

Seandel, Marco; Falciatori, Ilaria; Shmelkov, Sergey V.; Kim, Jiyeon; James, Daylon; Rafii, Shahin

2010-01-01

The undifferentiated spermatogonia of adult mouse testes are composed of both true stem cells and committed progenitors. It is unclear what normally prevents these adult germ cells from manifesting multipotency. The critical elements of the spermatogonial stem cell niche, while poorly understood, are thought to be composed of Sertoli cells with several other somatic cell types in close proximity. We recently discovered a novel orphan G-protein coupled receptor (GPR125) that is restricted to undifferentiated spermatogonia within the testis. GPR125 expression was maintained when the progenitor cells were extracted from the in vivo niche and propagated under growth conditions that recapitulate key elements of the niche. Such conditions preserved the ability of the cells to generate multipotent derivatives, known as multipotent adult spermatogonial derived progenitor cells (MASCs). Upon differentiation, the latter produced a variety tissues including functional endothelium, illustrating the potential applications of such cells. Thus, GPR125 represents a novel target for purifying adult stem and progenitors from tissues, with the goal of developing autologous multipotent cell lines. PMID:18256534

Transgelin is a TGFβ-inducible gene that regulates osteoblastic and adipogenic differentiation of human skeletal stem cells through actin cytoskeleston organization

PubMed Central

Elsafadi, M; Manikandan, M; Dawud, R A; Alajez, N M; Hamam, R; Alfayez, M; Kassem, M; Aldahmash, A; Mahmood, A

2016-01-01

Regenerative medicine is a novel approach for treating conditions in which enhanced bone regeneration is required. We identified transgelin (TAGLN), a transforming growth factor beta (TGFβ)-inducible gene, as an upregulated gene during in vitro osteoblastic and adipocytic differentiation of human bone marrow-derived stromal (skeletal) stem cells (hMSC). siRNA-mediated gene silencing of TAGLN impaired lineage differentiation into osteoblasts and adipocytes but enhanced cell proliferation. Additional functional studies revealed that TAGLN deficiency impaired hMSC cell motility and in vitro transwell cell migration. On the other hand, TAGLN overexpression reduced hMSC cell proliferation, but enhanced cell migration, osteoblastic and adipocytic differentiation, and in vivo bone formation. In addition, deficiency or overexpression of TAGLN in hMSC was associated with significant changes in cellular and nuclear morphology and cytoplasmic organelle composition as demonstrated by high content imaging and transmission electron microscopy that revealed pronounced alterations in the distribution of the actin filament and changes in cytoskeletal organization. Molecular signature of TAGLN-deficient hMSC showed that several genes and genetic pathways associated with cell differentiation, including regulation of actin cytoskeleton and focal adhesion pathways, were downregulated. Our data demonstrate that TAGLN has a role in generating committed progenitor cells from undifferentiated hMSC by regulating cytoskeleton organization. Targeting TAGLN is a plausible approach to enrich for committed hMSC cells needed for regenerative medicine application. PMID:27490926

Notch and affinity boundaries in Drosophila.

PubMed

Herranz, Héctor; Milán, Marco

2006-02-01

Cells in multicellular organisms often do not intermingle freely with each other. Differential cell affinities can contribute to organizing cells into different tissues. Drosophila limbs and the vertebrate central nervous system are subdivided into compartments. Cells in adjacent compartments do not mix. Cell interactions mediated by Notch-family receptors have been implicated in the specification of these compartment boundaries. Two recent reports analyze the role of the Notch signaling pathway in the generation of an affinity boundary in the Drosophila wing. The first report analyzes the connection between Notch and the actin cytoskeleton. The second report analyzes the differential requirements of Notch and the transcription factor Suppressor of Hairless in generating the affinity boundary.

Development of an Aquatic Bioassay Using the Medaka (Oryzias latipes) to Assess Human Health Risks: Tumor Immunodiagnosis.

DTIC Science & Technology

1992-04-27

Skeletal muscle 5 *Undifferentiated sarcoma Peripheral nerve 3 *Undifferentiated sarcoma Peritoneum 1 Hepatocellular carcinoma Liver 2...KD) Neurofilament (3 proteins 68, 150, Detects neuronal cell origin and 200 KD) Other: Alpha-l antitrypsin Common marker for hepatocellular carcinoma Alpha... hepatocellular carcinoma from cholangiocellular carcinoma (8). 14 4 FIGURE 1. Avldln-Blotin-PeroxidSse Complex Tecbnlqu6. :4odif led from A.K.Bhan

Following the 'tracks': Tramtrack69 regulates epithelial tube expansion in the Drosophila ovary through Paxillin, Dynamin, and the homeobox protein Mirror.

PubMed

Peters, Nathaniel C; Thayer, Nathaniel H; Kerr, Scott A; Tompa, Martin; Berg, Celeste A

2013-06-15

Epithelial tubes are the infrastructure for organs and tissues, and tube morphogenesis requires precise orchestration of cell signaling, shape, migration, and adhesion. Follicle cells in the Drosophila ovary form a pair of epithelial tubes whose lumens act as molds for the eggshell respiratory filaments, or dorsal appendages (DAs). DA formation is a robust and accessible model for studying the patterning, formation, and expansion of epithelial tubes. Tramtrack69 (TTK69), a transcription factor that exhibits a variable embryonic DNA-binding preference, controls DA lumen volume and shape by promoting tube expansion; the tramtrack mutation twin peaks (ttk(twk)) reduces TTK69 levels late in oogenesis, inhibiting this expansion. Microarray analysis of wild-type and ttk(twk) ovaries, followed by in situ hybridization and RNAi of candidate genes, identified the Phospholipase B-like protein Lamina ancestor (LAMA), the scaffold protein Paxillin, the endocytotic regulator Shibire (Dynamin), and the homeodomain transcription factor Mirror, as TTK69 effectors of DA-tube expansion. These genes displayed enriched expression in DA-tube cells, except lama, which was expressed in all follicle cells. All four genes showed reduced expression in ttk(twk) mutants and exhibited RNAi phenotypes that were enhanced in a ttk(twk)/+ background, indicating ttk(twk) genetic interactions. Although previous studies show that Mirror patterns the follicular epithelium prior to DA tubulogenesis, we show that Mirror has an independent, novel role in tube expansion, involving positive regulation of Paxillin. Thus, characterization of ttk(twk)-differentially expressed genes expands the network of TTK69 effectors, identifies novel epithelial tube-expansion regulators, and significantly advances our understanding of this vital developmental process. Copyright © 2013 Elsevier Inc. All rights reserved.

Colonization of heterochromatic genes by transposable elements in Drosophila.

PubMed

Dimitri, Patrizio; Junakovic, Nikolaj; Arcà, Bruno

2003-04-01

As a further step toward understanding transposable element-host genome interactions, we investigated the molecular anatomy of introns from five heterochromatic and 22 euchromatic protein-coding genes of Drosophila melanogaster. A total of 79 kb of intronic sequences from heterochromatic genes and 355 kb of intronic sequences from euchromatic genes have been used in Blast searches against Drosophila transposable elements (TEs). The results show that TE-homologous sequences belonging to 19 different families represent about 50% of intronic DNA from heterochromatic genes. In contrast, only 0.1% of the euchromatic intron DNA exhibits homology to known TEs. Intraspecific and interspecific size polymorphisms of introns were found, which are likely to be associated with changes in TE-related sequences. Together, the enrichment in TEs and the apparent dynamic state of heterochromatic introns suggest that TEs contribute significantly to the evolution of genes located in heterochromatin.

[Late-replicating regions in salivary gland polytene chromosomes of Drosophila melanogaster].

PubMed

Kolesnikov, T D; Andreenkova, N G; Beliaeva, E S; Goncharov, F P; Zykova, T Iu; Boldyreva, L V; Pokholkova, g V; Zhimulev, I F

2013-01-01

About 240 specific regions that are replicated at the very end of the S-phase have been identified in D. melanogaster polytene chromosomes. These regions have a repressive chromatine state, low gene density, long intergenic distances and are enriched in tissue specific genes. In polytene chromosomes, about a quarter of these regions have no enough time to complete replication. As a result, underreplication zones represented by fewer DNA copy number, appear. We studied 60 chromosome regions that demonstrated the most pronounced under-replication. By comparing the location of these regions on a molecular map with syntenic blocks found earlier for Drosophila species by von Grotthuss et al., 2010, we have shown that across the genus Drosophila, these regions tend to have conserved gene order. This forces us to assume the existence of evolutionary mechanisms aimed at maintaining the integrity of these regions.

Unbiased Combinatorial Genomic Approaches to Identify Alternative Therapeutic Targets within the TSC Signaling Network

DTIC Science & Technology

2014-06-01

Specifically, we combined the CRISPR genome editing system with a novel approach allowing efficient single cell cloning of Drosophila cells with the aim of...and culture these to produce cultures completely lacking wildtype sequence at the target locus. No robust methods existed to clone single Drosophila ...targeting all kinases and phosphatases (563 genes) in the Drosophila genome . 65 samples that displayed synthetic lethality (15 genes) or synthetic

Neuronal Cbl Controls Biosynthesis of Insulin-Like Peptides in Drosophila melanogaster

PubMed Central

Yu, Yue; Sun, Ying; He, Shengqi; Yan, Cheng; Rui, Liangyou; Li, Wenjun

2012-01-01

The Cbl family proteins function as both E3 ubiquitin ligases and adaptor proteins to regulate various cellular signaling events, including the insulin/insulin-like growth factor 1 (IGF1) and epidermal growth factor (EGF) pathways. These pathways play essential roles in growth, development, metabolism, and survival. Here we show that in Drosophila melanogaster, Drosophila Cbl (dCbl) regulates longevity and carbohydrate metabolism through downregulating the production of Drosophila insulin-like peptides (dILPs) in the brain. We found that dCbl was highly expressed in the brain and knockdown of the expression of dCbl specifically in neurons by RNA interference increased sensitivity to oxidative stress or starvation, decreased carbohydrate levels, and shortened life span. Insulin-producing neuron-specific knockdown of dCbl resulted in similar phenotypes. dCbl deficiency in either the brain or insulin-producing cells upregulated the expression of dilp genes, resulting in elevated activation of the dILP pathway, including phosphorylation of Drosophila Akt and Drosophila extracellular signal-regulated kinase (dERK). Genetic interaction analyses revealed that blocking Drosophila epidermal growth factor receptor (dEGFR)-dERK signaling in pan-neurons or insulin-producing cells by overexpressing a dominant-negative form of dEGFR abolished the effect of dCbl deficiency on the upregulation of dilp genes. Furthermore, knockdown of c-Cbl in INS-1 cells, a rat β-cell line, also increased insulin biosynthesis and glucose-stimulated secretion in an ERK-dependent manner. Collectively, these results suggest that neuronal dCbl regulates life span, stress responses, and metabolism by suppressing dILP production and the EGFR-ERK pathway mediates the dCbl action. Cbl suppression of insulin biosynthesis is evolutionarily conserved, raising the possibility that Cbl may similarly exert its physiological actions through regulating insulin production in β cells. PMID:22778134

Ionotropic Receptor-dependent moist and dry cells control hygrosensation in Drosophila.

PubMed

Knecht, Zachary A; Silbering, Ana F; Cruz, Joyner; Yang, Ludi; Croset, Vincent; Benton, Richard; Garrity, Paul A

2017-06-16

Insects use hygrosensation (humidity sensing) to avoid desiccation and, in vectors such as mosquitoes, to locate vertebrate hosts. Sensory neurons activated by either dry or moist air ('dry cells' and 'moist cells') have been described in many insects, but their behavioral roles and the molecular basis of their hygrosensitivity remain unclear. We recently reported that Drosophila hygrosensation relies on three Ionotropic Receptors (IRs) required for dry cell function: IR25a, IR93a and IR40a (Knecht et al., 2016). Here, we discover Drosophila moist cells and show that they require IR25a and IR93a together with IR68a, a conserved, but orphan IR. Both IR68a- and IR40a-dependent pathways drive hygrosensory behavior: each is important for dry-seeking by hydrated flies and together they underlie moist-seeking by dehydrated flies. These studies reveal that humidity sensing in Drosophila , and likely other insects, involves the combined activity of two molecularly related but neuronally distinct hygrosensing systems.

Altered Cytochrome c Display Precedes Apoptotic Cell Death in Drosophila

PubMed Central

Varkey, Johnson; Chen, Po; Jemmerson, Ronald; Abrams, John M.

1999-01-01

Drosophila affords a genetically well-defined system to study apoptosis in vivo. It offers a powerful extension to in vitro models that have implicated a requirement for cytochrome c in caspase activation and apoptosis. We found that an overt alteration in cytochrome c anticipates programmed cell death (PCD) in Drosophila tissues, occurring at a time that considerably precedes other known indicators of apoptosis. The altered configuration is manifested by display of an otherwise hidden epitope and occurs without release of the protein into the cytosol. Conditional expression of the Drosophila death activators, reaper or grim, provoked apoptogenic cytochrome c display and, surprisingly, caspase activity was necessary and sufficient to induce this alteration. In cell-free studies, cytosolic caspase activation was triggered by mitochondria from apoptotic cells but identical preparations from healthy cells were inactive. Our observations provide compelling validation of an early role for altered cytochrome c in PCD and suggest propagation of apoptotic physiology through reciprocal, feed-forward amplification involving cytochrome c and caspases. PMID:10037791

The cell-mediated immunity of Drosophila melanogaster: hemocyte lineages, immune compartments, microanatomy and regulation.

PubMed

Honti, Viktor; Csordás, Gábor; Kurucz, Éva; Márkus, Róbert; Andó, István

2014-01-01

In the animal kingdom, innate immunity is the first line of defense against invading pathogens. The dangers of microbial and parasitic attacks are countered by similar mechanisms, involving the prototypes of the cell-mediated immune responses, the phagocytosis and encapsulation. Work on Drosophila has played an important role in promoting an understanding of the basic mechanisms of phylogenetically conserved modules of innate immunity. The aim of this review is to survey the developments in the identification and functional definition of immune cell types and the immunological compartments of Drosophila melanogaster. We focus on the molecular and developmental aspects of the blood cell types and compartments, as well as the dynamics of blood cell development and the immune response. Further advances in the characterization of the innate immune mechanisms in Drosophila will provide basic clues to the understanding of the importance of the evolutionary conserved mechanisms of innate immune defenses in the animal kingdom. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

Yokoo, Masako; Fujita, Ryosuke; Innate Immunity Laboratory, Graduate School of Life Science and Creative Research Institution, Hokkaido University, Sapporo 001-0021

Highlights: •The baculovirus vector infiltrates the cells of economic important fishes. •Drosophila Mos1 transposase expressed in fish cells maintains its ability to localize to the nucleus. •The baculoviral vector carrying Mos1 is a useful tool to stably transform fish cells. -- Abstract: Drosophila Mos1 belongs to the mariner family of transposons, which are one of the most ubiquitous transposons among eukaryotes. We first determined nuclear transportation of the Drosophila Mos1-EGFP fusion protein in fish cell lines because it is required for a function of transposons. We next constructed recombinant baculoviral vectors harboring the Drosophila Mos1 transposon or marker genes locatedmore » between Mos1 inverted repeats. The infectivity of the recombinant virus to fish cells was assessed by monitoring the expression of a fluorescent protein encoded in the viral genome. We detected transgene expression in CHSE-214, HINAE, and EPC cells, but not in GF or RTG-2 cells. In the co-infection assay of the Mos1-expressing virus and reporter gene-expressing virus, we successfully transformed CHSE-214 and HINAE cells. These results suggest that the combination of a baculovirus and Mos1 transposable element may be a tool for transgenesis in fish cells.« less

Impact of copper oxide nanomaterials on differentiated and undifferentiated Caco-2 intestinal epithelial cells; assessment of cytotoxicity, barrier integrity, cytokine production and nanomaterial penetration.

PubMed

Ude, Victor C; Brown, David M; Viale, Luca; Kanase, Nilesh; Stone, Vicki; Johnston, Helinor J

2017-08-23

Copper oxide nanomaterials (CuO NMs) are exploited in a diverse array of products including antimicrobials, inks, cosmetics, textiles and food contact materials. There is therefore a need to assess the toxicity of CuO NMs to the gastrointestinal (GI) tract since exposure could occur via direct oral ingestion, mucocillary clearance (following inhalation) or hand to mouth contact. Undifferentiated Caco-2 intestinal cells were exposed to CuO NMs (10 nm) at concentrations ranging from 0.37 to 78.13 μg/cm 2 Cu (equivalent to 1.95 to 250 μg/ml) and cell viability assessed 24 h post exposure using the alamar blue assay. The benchmark dose (BMD 20), determined using PROAST software, was identified as 4.44 μg/cm 2 for CuO NMs, and 4.25 μg/cm 2 for copper sulphate (CuSO 4 ), which informed the selection of concentrations for further studies. The differentiation status of cells and the impact of CuO NMs and CuSO 4 on the integrity of the differentiated Caco-2 cell monolayer were assessed by measurement of trans-epithelial electrical resistance (TEER), staining for Zonula occludens-1 (ZO-1) and imaging of cell morphology using scanning electron microscopy (SEM). The impact of CuO NMs and CuSO 4 on the viability of differentiated cells was performed via assessment of cell number (DAPI staining), and visualisation of cell morphology (light microscopy). Interleukin-8 (IL-8) production by undifferentiated and differentiated Caco-2 cells following exposure to CuO NMs and CuSO 4 was determined using an ELISA. The copper concentration in the cell lysate, apical and basolateral compartments were measured with Inductive Coupled Plasma Optical Emission Spectrometry (ICP-OES) and used to calculate the apparent permeability coefficient (P app ); a measure of barrier permeability to CuO NMs. For all experiments, CuSO 4 was used as an ionic control. CuO NMs and CuSO 4 caused a concentration dependent decrease in cell viability in undifferentiated cells. CuO NMs and CuSO 4 translocated across the differentiated Caco-2 cell monolayer. CuO NM mediated IL-8 production was over 2-fold higher in undifferentiated cells. A reduction in cell viability in differentiated cells was not responsible for the lower level of cytokine production observed. Both CuO NMs and CuSO 4 decreased TEER values to a similar extent, and caused tight junction dysfunction (ZO-1 staining), suggesting that barrier integrity was disrupted. CuO NMs and CuSO 4 stimulated IL-8 production by Caco-2 cells, decreased barrier integrity and thereby increased the P app and translocation of Cu. There was no significant enhancement in potency of the CuO NMs compared to CuSO 4 . Differentiated Caco-2 cells were identified as a powerful model to assess the impacts of ingested NMs on the GI tract.

The neuronal differentiation process involves a series of antioxidant proteins.

PubMed

Oh, J-E; Karlmark Raja, K; Shin, J-H; Hengstschläger, M; Pollak, A; Lubec, G

2005-11-01

Involvement of individual antioxidant proteins (AOXP) and antioxidants in the differentiation process has been already reported. A systematic search strategy for detecting differentially regulated AOXP in neuronal differentiation, however, has not been published so far. The aim of this study was to provide an analytical tool identifying AOXP and to generate a differentiation-related AOXP expressional pattern. The undifferentiated N1E-115 neuroblastoma cell line was switched into a neuronal phenotype by DMSO treatment and used for proteomic experiments: We used two-dimensional gel electrophoresis followed by unambiguous mass spectrometrical (MALDI-TOF-TOF) identification of proteins to generate a map of AOXP. 16 AOXP were unambiguously determined in both cell lines; catalase, thioredoxin domain-containing protein 4 and hypothetical glutaredoxin/glutathione S-transferase C terminus-containing protein were detectable in the undifferentiated cells only. Five AOXP were observed in both, undifferentiated and differentiated cells and thioredoxin, thioredoxin-like protein p19, thioredoxin reductase 1, superoxide dismutases (Mn and Cu-Zn), glutathione synthetase, glutathione S-transferase P1 and Mu1 were detected in differentiated cells exclusively. Herein a differential expressional pattern is presented that reveals so far unpublished antioxidant principles involved in neuronal differentiation by a protein chemical approach, unambiguously identifying AOXP. This finding not only shows concomitant determination of AOXP but also serves as an analytical tool and forms the basis for design of future studies addressing AOXP and differentiation per se.

MV-NIS Infected Mesenchymal Stem Cells in Treating Patients With Recurrent Ovarian Cancer

ClinicalTrials.gov

2018-01-31

Malignant Ovarian Brenner Tumor; Ovarian Clear Cell Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Adenocarcinoma; Ovarian Seromucinous Carcinoma; Ovarian Serous Adenocarcinoma; Ovarian Transitional Cell Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Undifferentiated Ovarian Carcinoma

Relationship between ketamine-induced developmental neurotoxicity and NMDA receptor-mediated calcium influx in neural stem cell-derived neurons.

PubMed

Wang, Cheng; Liu, Fang; Patterson, Tucker A; Paule, Merle G; Slikker, William

2017-05-01

Ketamine, a noncompetitive NMDA receptor antagonist, is used as a general anesthetic and recent data suggest that general anesthetics can cause neuronal damage when exposure occurs during early brain development. To elucidate the underlying mechanisms associated with ketamine-induced neurotoxicity, stem cell-derived models, such as rodent neural stem cells harvested from rat fetuses and/or neural stem cells derived from human induced pluripotent stem cells (iPSC) can be utilized. Prolonged exposure of rodent neural stem cells to clinically-relevant concentrations of ketamine resulted in elevated NMDA receptor levels as indicated by NR1subunit over-expression in neurons. This was associated with enhanced damage in neurons. In contrast, the viability and proliferation rate of undifferentiated neural stem cells were not significantly affected after ketamine exposure. Calcium imaging data indicated that 50μM NMDA did not cause a significant influx of calcium in typical undifferentiated neural stem cells; however, it did produce an immediate elevation of intracellular free Ca 2+ [Ca 2+ ] i in differentiated neurons derived from the same neural stem cells. This paper reviews the literature on this subject and previous findings suggest that prolonged exposure of developing neurons to ketamine produces an increase in NMDA receptor expression (compensatory up-regulation) which allows for a higher/toxic influx of calcium into neurons once ketamine is removed from the system, leading to neuronal cell death likely due to elevated reactive oxygen species generation. The absence of functional NMDA receptors in cultured neural stem cells likely explains why clinically-relevant concentrations of ketamine did not affect undifferentiated neural stem cell viability. Published by Elsevier B.V.

Flower-deficient mice have reduced susceptibility to skin papilloma formation

PubMed Central

Petrova, Evgeniya; López-Gay, Jesús M.; Rhiner, Christa; Moreno, Eduardo

2012-01-01

SUMMARY Skin papillomas arise as a result of clonal expansion of mutant cells. It has been proposed that the expansion of pretumoral cell clones is propelled not only by the increased proliferation capacity of mutant cells, but also by active cell selection. Previous studies in Drosophila describe a clonal selection process mediated by the Flower (Fwe) protein, whereby cells that express certain Fwe isoforms are recognized and forced to undergo apoptosis. It was further shown that knock down of fwe expression in Drosophila can prevent the clonal expansion of dMyc-overexpressing pretumoral cells. Here, we study the function of the single predicted mouse homolog of Drosophila Fwe, referred to as mFwe, by clonal overexpression of mFwe isoforms in Drosophila and by analyzing mFwe knock-out mice. We show that clonal overexpression of certain mFwe isoforms in Drosophila also triggers non-autonomous cell death, suggesting that Fwe function is evolutionarily conserved. Although mFwe-deficient mice display a normal phenotype, they develop a significantly lower number of skin papillomas upon exposure to DMBA/TPA two-stage skin carcinogenesis than do treated wild-type and mFwe heterozygous mice. Furthermore, mFwe expression is higher in papillomas and the papilloma-surrounding skin of treated wild-type mice compared with the skin of untreated wild-type mice. Thus, we propose that skin papilloma cells take advantage of mFwe activity to facilitate their clonal expansion. PMID:22362363

Drosophila glypican Dally-like acts in FGF-receiving cells to modulate FGF signaling during tracheal morphogenesis

PubMed Central

Yan, Dong; Lin, Xinhua

2007-01-01

Summary Previous studies in Drosophila have shown that heparan sulfate proteoglycans (HSPGs) are involved in both breathless (btl)- and heartless (htl)-mediated FGF signaling during embryogenesis. However, the mechanism(s) by which HSPGs control Btl and Htl signaling is unknown. Here we show that dally-like (dlp, a Drosophila glypican) mutant embryos exhibit severe defects in tracheal morphogenesis and show a reduction in btl-mediated FGF signaling activity. However, htl-dependent mesodermal cell migration is not affected in dlp mutant embryos. Furthermore, expression of Dlp, but not other Drosophila HSPGs, can restore effectively the tracheal morphogenesis in dlp embryos. Rescue experiments in dlp embryos demonstrate that Dlp functions only in Bnl/FGF receiving cells in a cell-autonomous manner, but is not essential for Bnl/FGF expression cells. To further dissect the mechanism(s) of Dlp in Btl signaling, we analyzed the role of Dlp in Btl-mediated air sac tracheoblast formation in wing discs. Mosaic analysis experiments show that removal of HSPG activity in FGF-producing or other surrounding cells does not affect tracheoblasts migration, while HSPG mutant tracheoblast cells fail to receive FGF signaling. Together, our results argue strongly that HSPGs regulate Btl signaling exclusively in FGF-receiving cells as co-receptors, but are not essential for the secretion and distribution of the FGF ligand. This mechanism is distinct from HSPG functions in morphogen distribution, and is likely a general paradigm for HSPG functions in FGF signaling in Drosophila. PMID:17959166

Endocrine disrupting chemicals affect the adipogenic differentiation of mesenchymal stem cells in distinct ontogenetic windows

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

Biemann, Ronald, E-mail: ronald.biemann@medizin.uni-halle.de; Navarrete Santos, Anne; Navarrete Santos, Alexander

Highlights: Black-Right-Pointing-Pointer Endocrine disrupting chemicals affect adipogenesis in mesenchymal stem cells (MSC). Black-Right-Pointing-Pointer The adipogenic impact depends strongly on the window of exposure. Black-Right-Pointing-Pointer Bisphenol A reduces the potential of MSC to differentiate into adipocytes. Black-Right-Pointing-Pointer DEHP and TBT trigger the adipogenic differentiation of mesenchymal stem cells. Black-Right-Pointing-Pointer BPA, DEHP and TBT did not affect adipogenesis in embryonic stem cells. -- Abstract: Endocrine disrupting chemicals (EDC) like bisphenol A (BPA), bis(2-ethylhexyl)phthalate (DEHP) and tributyltin (TBT) are ubiquitously present in the environment and in human tissues. They bind to nuclear hormone receptors and affect cellular and developmental processes. In this study,more » we show that BPA, DEHP and TBT affect the adipogenic differentiation of murine mesenchymal stem cells (MSC, C3H/10T1/2) in a concentration-, stage- and compound-specific manner. C3H/10T1/2 cells and embryonic stem cells (CGR8) were exposed to BPA, DEHP or TBT at different stages of cell determination and differentiation (undifferentiated growth, adipogenic induction and terminal adipogenic differentiation). The final amount of differentiated adipocytes, cellular triglyceride content and mRNA expression of adipogenic marker genes (adiponectin, FABP4, PPAR{gamma}2, LPL) were quantified and compared with corresponding unexposed cells. BPA (10 {mu}M) decreased subsequent adipogenic differentiation of MSC, when cells were exposed during undifferentiated growth. In contrast, DEHP (100 {mu}M) during the hormonal induction period, and TBT (100 nM) in all investigated stages, enhanced adipogenesis. Importantly, exposure of undifferentiated murine embryonic stem cells did not show any effect of the investigated EDC on subsequent adipogenic differentiation.« less

The p25 Subunit of the Dynactin Complex is Required for Dynein-Early Endosome Interaction

DTIC Science & Technology

2011-01-01

Recently, spectrin mutations in Drosophila melanogaster have been shown to also cause defective axonal transport and neu- ronal degeneration...A and study showed that in Arp1-RNAi–treated Drosophila S2 cells, although dynactin cannot be fully assembled and vesicle transport is defective...Muresan et al., 2001; Schroer 2004). However, this idea has been under debate recently, mainly because results from a study in Drosophila S2 cells

Tissue damage-induced intestinal stem cell division in Drosophila

PubMed Central

Amcheslavsky, Alla; Jiang, Jin; Ip, Y. Tony

2009-01-01

SUMMARY Stem cell division is essential for tissue integrity during growth, aging, and pathogenic assaults. Adult gastrointestinal tract encounters numerous stimulations and impaired tissue regeneration may lead to inflammatory diseases and cancer. Intestinal stem cells in adult Drosophila have recently been identified and shown to replenish the various cell types within the midgut. However, it is not known whether these intestinal stem cells can respond to environmental challenges. By feeding dextran sulfate sodium and bleomycin to flies and by expressing apoptotic proteins, we show that Drosophila intestinal stem cells can increase the rate of division in response to tissue damage. Moreover, if tissue damage results in epithelial cell loss, the newly formed enteroblasts can differentiate into mature epithelial cells. By using this newly established system of intestinal stem cell proliferation and tissue regeneration, we find that the insulin receptor signaling pathway is required for intestinal stem cell division. PMID:19128792

Molecular Landscape of Modified Histones in Drosophila Heterochromatic Genes and Euchromatin-Heterochromatin Transition Zones

PubMed Central

Yasuhara, Jiro C; Wakimoto, Barbara T

2008-01-01

Constitutive heterochromatin is enriched in repetitive sequences and histone H3-methylated-at-lysine 9. Both components contribute to heterochromatin's ability to silence euchromatic genes. However, heterochromatin also harbors hundreds of expressed genes in organisms such as Drosophila. Recent studies have provided a detailed picture of sequence organization of D. melanogaster heterochromatin, but how histone modifications are associated with heterochromatic sequences at high resolution has not been described. Here, distributions of modified histones in the vicinity of heterochromatic genes of normal embryos and embryos homozygous for a chromosome rearrangement were characterized using chromatin immunoprecipitation and genome tiling arrays. We found that H3-di-methylated-at-lysine 9 (H3K9me2) was depleted at the 5′ ends but enriched throughout transcribed regions of heterochromatic genes. The profile was distinct from that of euchromatic genes and suggests that heterochromatic genes are integrated into, rather than insulated from, the H3K9me2-enriched domain. Moreover, the profile was only subtly affected by a Su(var)3–9 null mutation, implicating a histone methyltransferase other than SU(VAR)3–9 as responsible for most H3K9me2 associated with heterochromatic genes in embryos. On a chromosomal scale, we observed a sharp transition to the H3K9me2 domain, which coincided with increased retrotransposon density in the euchromatin-heterochromatin (eu-het) transition zones on the long chromosome arms. Thus, a certain density of retrotransposons, rather than specific boundary elements, may demarcate Drosophila pericentric heterochromatin. We also demonstrate that a chromosome rearrangement that created a new eu-het junction altered H3K9me2 distribution and induced new euchromatic sites of enrichment as far as several megabases away from the breakpoint. Taken together, the findings argue against simple classification of H3K9me as the definitive signature of silenced genes, and clarify roles of histone modifications and repetitive DNAs in heterochromatin. The results are also relevant for understanding the effects of chromosome aberrations and the megabase scale over which epigenetic position effects can operate in multicellular organisms. PMID:18208336

From Embryo to Adult: Hematopoiesis along the Drosophila Life Cycle.

PubMed

Ramond, Elodie; Meister, Marie; Lemaitre, Bruno

2015-05-26

Studies on Drosophila hematopoiesis have thus far focused on the embryonic and larval origin of hemocytes, the fly blood cells. In this issue of Developmental Cell, Ghosh et al. (2015) identify adult hematopoietic hubs containing progenitors that can differentiate into different blood cell types. Copyright © 2015 Elsevier Inc. All rights reserved.

[Drosophila melanogaster as a model for studying the function of animal viral proteins].

PubMed

Omelianchuk, L V; Iudina, O S

2011-07-01

Studies in which Drosophila melanogaster individuals carrying transgenes of animal viruses were used to analyze the action of animal viral proteins on the cell are reviewed. The data presented suggest that host specificity of viruses is determined by their proteins responsible for the penetration of the virus into the cell, while viral proteins responsible for interactions with the host cell are much less host-specific. Due to this, the model of Drosophila with its developed system of searching for genetic interactions can be used to find intracellular targets for the action of viral proteins of the second group.

Ceftaroline modulates the innate immune and host defense responses of immunocompetent cells exposed to cigarette smoke.

PubMed

Bruno, A; Cipollina, C; Di Vincenzo, S; Siena, L; Dino, P; Di Gaudio, F; Gjomarkaj, M; Pace, E

2017-09-05

Cigarette smoke, the principal risk factor for chronic obstructive pulmonary disease (COPD), negatively influences the effectiveness of the immune system's response to a pathogen. The antibiotic ceftaroline exerts immune-modulatory effects in bronchial epithelial cells exposed to cigarette smoke. The present study aims to assess the effects of ceftaroline on TLR2 and TLR4 expression, LPS binding and TNF-α and human beta defensin (HBD2) release in an undifferentiated and PMA-differentiated human monocyte cell line (THP-1) exposed or not to cigarette smoke extracts (CSE). TLR2, TLR4, and LPS binding were assessed by flow cytometry, TNF-α and HBD2 release were evaluated by ELISA. The constitutive expression of TLR2 and TLR4 and LPS binding were higher in differentiated compared to undifferentiated THP-1 cells. In undifferentiated THP-1 cells, CSE increased TLR2 and TLR4 protein levels, LPS binding and TNF-α release and reduced HBD2 release and ceftaroline counteracted all these effects. In differentiated THP-1, CSE did not significantly affect TLR2 and TLR4 expression and LPS binding but reduced HBD2 release and increased TNF-α release. Ceftaroline counteracted the effects of CSE on HBD2 release in differentiated THP-1. Ceftaroline counteracts the effect of CSE in immune cells by increasing the effectiveness of the innate immune system. This effect may also assist in reducing pathogen activity and recurrent exacerbations in COPD patients. Copyright © 2017 Elsevier B.V. All rights reserved.

Ultrastructural characteristics of three undifferentiated mouse embryonic stem cell lines and their differentiated three-dimensional derivatives: a comparative study.

PubMed

Alharbi, Suzan; Elsafadi, Mona; Mobarak, Mohammed; Alrwili, Ali; Vishnubalaji, Radhakrishnan; Manikandan, Muthurangan; Al-Qudsi, Fatma; Karim, Saleh; Al-Nabaheen, May; Aldahmash, Abdullah; Mahmood, Amer

2014-04-01

The fine structures of mouse embryonic stem cells (mESCs) grown as colonies and differentiated in three-dimensional (3D) culture as embryoid bodies (EBs) were analyzed by transmission electron microscopy. Undifferentiated mESCs expressed markers that proved their pluripotency. Differentiated EBs expressed different differentiation marker proteins from the three germ layers. The ultrastructure of mESCs revealed the presence of microvilli on the cell surfaces, large and deep infolded nuclei, low cytoplasm-to-nuclear ratios, frequent lipid droplets, nonprominent Golgi apparatus, and smooth endoplasmic reticulum. In addition, we found prominent juvenile mitochondria and free ribosomes-rich cytoplasm in mESCs. Ultrastructure of the differentiated mESCs as EBs showed different cell arrangements, which indicate the different stages of EB development and differentiation. The morphologies of BALB/c and 129 W9.5 EBs were very similar at day 4, whereas C57BL/6 EBs were distinct from the others at day 4. This finding suggested that differentiation of EBs from different cell lines occurs in the same pattern but not at the same rate. Conversely, the ultrastructure results of BALB/c and 129 W9.5 ESCs revealed differentiating features, such as the dilated profile of a rough endoplasmic reticulum. In addition, we found low expression levels of undifferentiated markers on the outer cells of BALB/c and 129 W9.5 mESC colonies, which suggests a faster differentiation potential.

Phosphatidylserine recognition and induction of apoptotic cell clearance by Drosophila engulfment receptor Draper.

PubMed

Tung, Tran Thanh; Nagaosa, Kaz; Fujita, Yu; Kita, Asana; Mori, Hiroki; Okada, Ryo; Nonaka, Saori; Nakanishi, Yoshinobu

2013-05-01

The membrane phospholipid phosphatidylserine is exposed on the cell surface during apoptosis and acts as an eat-me signal in the phagocytosis of apoptotic cells in mammals and nematodes. However, whether this is also true in insects was unclear. When milk fat globule-epidermal growth factor 8, a phosphatidylserine-binding protein of mammals, was ectopically expressed in Drosophila, the level of phagocytosis was reduced, whereas this was not the case for the same protein lacking a domain responsible for the binding to phosphatidylserine. We found that the extracellular region of Draper, an engulfment receptor of Drosophila, binds to phosphatidylserine in an enzyme-linked immunosorbent assay-like solid-phase assay and in an assay for surface plasmon resonance. A portion of Draper containing domains EMI and NIM located close to the N-terminus was required for binding to phosphatidylserine, and a Draper protein lacking this region was not active in Drosophila. Finally, the level of tyrosine-phosphorylated Draper, indicative of the activation of Draper, in a hemocyte-derived cell line was increased after treatment with phosphatidylserine-containing liposome. These results indicated that phosphatidylserine serves as an eat-me signal in the phagocytic removal of apoptotic cells in Drosophila and that Draper is a phosphatidylserine-binding receptor for phagocytosis.

Evaluating the Autonomy of the Drosophila Circadian Clock in Dissociated Neuronal Culture

PubMed Central

Sabado, Virginie; Vienne, Ludovic; Nagoshi, Emi

2017-01-01

Circadian behavioral rhythms offer an excellent model to study intricate interactions between the molecular and neuronal mechanisms of behavior. In mammals, pacemaker neurons in the suprachiasmatic nucleus (SCN) generate rhythms cell-autonomously, which are synchronized by the network interactions within the circadian circuit to drive behavioral rhythms. However, whether this principle is universal to circadian systems in animals remains unanswered. Here, we examined the autonomy of the Drosophila circadian clock by monitoring transcriptional and post-transcriptional rhythms of individual clock neurons in dispersed culture with time-lapse microscopy. Expression patterns of the transcriptional reporter show that CLOCK/CYCLE (CLK/CYC)-mediated transcription is constantly active in dissociated clock neurons. In contrast, the expression profile of the post-transcriptional reporter indicates that PERIOD (PER) protein levels fluctuate and ~10% of cells display rhythms in PER levels with periods in the circadian range. Nevertheless, PER and TIM are enriched in the cytoplasm and no periodic PER nuclear accumulation was observed. These results suggest that repression of CLK/CYC-mediated transcription by nuclear PER is impaired, and thus the negative feedback loop of the molecular clock is incomplete in isolated clock neurons. We further demonstrate that, by pharmacological assays using the non-amidated form of neuropeptide pigment-dispersing factor (PDF), which could be specifically secreted from larval LNvs and adult s-LNvs, downstream events of the PDF signaling are partly impaired in dissociated larval clock neurons. Although non-amidated PDF is likely to be less active than the amidated one, these results point out the possibility that alteration in PDF downstream signaling may play a role in dampening of molecular rhythms in isolated clock neurons. Taken together, our results suggest that Drosophila clocks are weak oscillators that need to be in the intact circadian circuit to generate robust 24-h rhythms. PMID:29075180

The NSL Complex Regulates Housekeeping Genes in Drosophila

PubMed Central

Raja, Sunil Jayaramaiah; Holz, Herbert; Luscombe, Nicholas M.; Manke, Thomas; Akhtar, Asifa

2012-01-01

MOF is the major histone H4 lysine 16-specific (H4K16) acetyltransferase in mammals and Drosophila. In flies, it is involved in the regulation of X-chromosomal and autosomal genes as part of the MSL and the NSL complexes, respectively. While the function of the MSL complex as a dosage compensation regulator is fairly well understood, the role of the NSL complex in gene regulation is still poorly characterized. Here we report a comprehensive ChIP–seq analysis of four NSL complex members (NSL1, NSL3, MBD-R2, and MCRS2) throughout the Drosophila melanogaster genome. Strikingly, the majority (85.5%) of NSL-bound genes are constitutively expressed across different cell types. We find that an increased abundance of the histone modifications H4K16ac, H3K4me2, H3K4me3, and H3K9ac in gene promoter regions is characteristic of NSL-targeted genes. Furthermore, we show that these genes have a well-defined nucleosome free region and broad transcription initiation patterns. Finally, by performing ChIP–seq analyses of RNA polymerase II (Pol II) in NSL1- and NSL3-depleted cells, we demonstrate that both NSL proteins are required for efficient recruitment of Pol II to NSL target gene promoters. The observed Pol II reduction coincides with compromised binding of TBP and TFIIB to target promoters, indicating that the NSL complex is required for optimal recruitment of the pre-initiation complex on target genes. Moreover, genes that undergo the most dramatic loss of Pol II upon NSL knockdowns tend to be enriched in DNA Replication–related Element (DRE). Taken together, our findings show that the MOF-containing NSL complex acts as a major regulator of housekeeping genes in flies by modulating initiation of Pol II transcription. PMID:22723752

Loss of PTB or Negative Regulation of Notch mRNA Reveals Distinct Zones of Notch and Actin Protein Accumulation in Drosophila Embryo

PubMed Central

Wesley, Cedric S.; Guo, Heng; Chaudhry, Kanita A.; Thali, Markus J.; Yin, Jerry C.; Clason, Todd; Wesley, Umadevi V.

2011-01-01

Polypyrimidine Tract Binding (PTB) protein is a regulator of mRNA processing and translation. Genetic screens and studies of wing and bristle development during the post-embryonic stages of Drosophila suggest that it is a negative regulator of the Notch pathway. How PTB regulates the Notch pathway is unknown. Our studies of Drosophila embryogenesis indicate that (1) the Notch mRNA is a potential target of PTB, (2) PTB and Notch functions in the dorso-lateral regions of the Drosophila embryo are linked to actin regulation but not their functions in the ventral region, and (3) the actin-related Notch activity in the dorso-lateral regions might require a Notch activity at or near the cell surface that is different from the nuclear Notch activity involved in cell fate specification in the ventral region. These data raise the possibility that the Drosophila embryo is divided into zones of different PTB and Notch activities based on whether or not they are linked to actin regulation. They also provide clues to the almost forgotten role of Notch in cell adhesion and reveal a role for the Notch pathway in cell fusions. PMID:21750738

Dynamic miRNA-mRNA regulations are essential for maintaining Drosophila immune homeostasis during Micrococcus luteus infection.

PubMed

Wei, Guanyun; Sun, Lianjie; Li, Ruimin; Li, Lei; Xu, Jiao; Ma, Fei

2018-04-01

Pathogen bacteria infections can lead to dynamic changes of microRNA (miRNA) and mRNA expression profiles, which may control synergistically the outcome of immune responses. To reveal the role of dynamic miRNA-mRNA regulation in Drosophila innate immune responses, we have detailedly analyzed the paired miRNA and mRNA expression profiles at three time points during Drosophila adult males with Micrococcus luteus (M. luteus) infection using RNA- and small RNA-seq data. Our results demonstrate that differentially expressed miRNAs and mRNAs represent extensively dynamic changes over three time points during Drosophila with M. luteus infection. The pathway enrichment analysis indicates that differentially expressed genes are involved in diverse signaling pathways, including Toll and Imd as well as orther signaling pathways at three time points during Drosophila with M. luteus infection. Remarkably, the dynamic change of miRNA expression is delayed by compared to mRNA expression change over three time points, implying that the "time" parameter should be considered when the function of miRNA/mRNA is further studied. In particular, the dynamic miRNA-mRNA regulatory networks have shown that miRNAs may synergistically regulate gene expressions of different signaling pathways to promote or inhibit innate immune responses and maintain homeostasis in Drosophila, and some new regulators involved in Drosophila innate immune response have been identified. Our findings strongly suggest that miRNA regulation is a key mechanism involved in fine-tuning cooperatively gene expressions of diverse signaling pathways to maintain innate immune response and homeostasis in Drosophila. Taken together, the present study reveals a novel role of dynamic miRNA-mRNA regulation in immune response to bacteria infection, and provides a new insight into the underlying molecular regulatory mechanism of Drosophila innate immune responses. Copyright © 2017 Elsevier Ltd. All rights reserved.

Drosophila CTCF tandemly aligns with other insulator proteins at the borders of H3K27me3 domains.

PubMed

Van Bortle, Kevin; Ramos, Edward; Takenaka, Naomi; Yang, Jingping; Wahi, Jessica E; Corces, Victor G

2012-11-01

Several multiprotein DNA complexes capable of insulator activity have been identified in Drosophila melanogaster, yet only CTCF, a highly conserved zinc finger protein, and the transcription factor TFIIIC have been shown to function in mammals. CTCF is involved in diverse nuclear activities, and recent studies suggest that the proteins with which it associates and the DNA sequences that it targets may underlie these various roles. Here we show that the Drosophila homolog of CTCF (dCTCF) aligns in the genome with other Drosophila insulator proteins such as Suppressor of Hairy wing [SU(HW)] and Boundary Element Associated Factor of 32 kDa (BEAF-32) at the borders of H3K27me3 domains, which are also enriched for associated insulator proteins and additional cofactors. RNAi depletion of dCTCF and combinatorial knockdown of gene expression for other Drosophila insulator proteins leads to a reduction in H3K27me3 levels within repressed domains, suggesting that insulators are important for the maintenance of appropriate repressive chromatin structure in Polycomb (Pc) domains. These results shed new insights into the roles of insulators in chromatin domain organization and support recent models suggesting that insulators underlie interactions important for Pc-mediated repression. We reveal an important relationship between dCTCF and other Drosophila insulator proteins and speculate that vertebrate CTCF may also align with other nuclear proteins to accomplish similar functions.

Drosophila CTCF tandemly aligns with other insulator proteins at the borders of H3K27me3 domains

PubMed Central

Van Bortle, Kevin; Ramos, Edward; Takenaka, Naomi; Yang, Jingping; Wahi, Jessica E.; Corces, Victor G.

2012-01-01

Several multiprotein DNA complexes capable of insulator activity have been identified in Drosophila melanogaster, yet only CTCF, a highly conserved zinc finger protein, and the transcription factor TFIIIC have been shown to function in mammals. CTCF is involved in diverse nuclear activities, and recent studies suggest that the proteins with which it associates and the DNA sequences that it targets may underlie these various roles. Here we show that the Drosophila homolog of CTCF (dCTCF) aligns in the genome with other Drosophila insulator proteins such as Suppressor of Hairy wing [SU(HW)] and Boundary Element Associated Factor of 32 kDa (BEAF-32) at the borders of H3K27me3 domains, which are also enriched for associated insulator proteins and additional cofactors. RNAi depletion of dCTCF and combinatorial knockdown of gene expression for other Drosophila insulator proteins leads to a reduction in H3K27me3 levels within repressed domains, suggesting that insulators are important for the maintenance of appropriate repressive chromatin structure in Polycomb (Pc) domains. These results shed new insights into the roles of insulators in chromatin domain organization and support recent models suggesting that insulators underlie interactions important for Pc-mediated repression. We reveal an important relationship between dCTCF and other Drosophila insulator proteins and speculate that vertebrate CTCF may also align with other nuclear proteins to accomplish similar functions. PMID:22722341

Apoptosis in Drosophila: which role for mitochondria?

PubMed

Clavier, Amandine; Rincheval-Arnold, Aurore; Colin, Jessie; Mignotte, Bernard; Guénal, Isabelle

2016-03-01

It is now well established that the mitochondrion is a central regulator of mammalian cell apoptosis. However, the importance of this organelle in non-mammalian apoptosis has long been regarded as minor, mainly because of the absence of a crucial role for cytochrome c in caspase activation. Recent results indicate that the control of caspase activation and cell death in Drosophila occurs at the mitochondrial level. Numerous proteins, including RHG proteins and proteins of the Bcl-2 family that are key regulators of Drosophila apoptosis, constitutively or transiently localize in mitochondria. These proteins participate in the cell death process at different levels such as degradation of Diap1, a Drosophila IAP, production of mitochondrial reactive oxygen species or stimulation of the mitochondrial fission machinery. Here, we review these mitochondrial events that might have their counterpart in human.

Drosophila COP9 signalosome subunit 7 interacts with multiple genomic loci to regulate development.

PubMed

Singer, Ruth; Atar, Shimshi; Atias, Osnat; Oron, Efrat; Segal, Daniel; Hirsch, Joel A; Tuller, Tamir; Orian, Amir; Chamovitz, Daniel A

2014-09-01

The COP9 signalosome protein complex has a central role in the regulation of development of multicellular organisms. While the function of this complex in ubiquitin-mediated protein degradation is well established, results over the past few years have hinted that the COP9 signalosome may function more broadly in the regulation of gene expression. Here, using DamID technology, we show that COP9 signalosome subunit 7 functionally associates with a large number of genomic loci in the Drosophila genome, and show that the expression of many genes within these loci is COP9 signalosome-dependent. This association is likely direct as we show CSN7 binds DNA in vitro. The genes targeted by CSN7 are preferentially enriched for transcriptionally active regions of the genome, and are involved in the regulation of distinct gene ontology groupings including imaginal disc development and cell-cycle control. In accord, loss of CSN7 function leads to cell-cycle delay and altered wing development. These results indicate that CSN7, and by extension the entire COP9 signalosome, functions directly in transcriptional control. While the COP9 signalosome protein complex has long been known to regulate protein degradation, here we expand the role of this complex by showing that subunit 7 binds DNA in vitro and functions directly in vivo in transcriptional control of developmentally important pathways that are relevant for human health. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

SERCA directs cell migration and branching across species and germ layers

PubMed Central

Lansdale, Nick; Navarro, Sonia; Truong, Thai V.; Bower, Dan J.; Featherstone, Neil C.; Connell, Marilyn G.; Al Alam, Denise; Frey, Mark R.; Trinh, Le A.; Fernandez, G. Esteban; Warburton, David; Fraser, Scott E.; Bennett, Daimark; Jesudason, Edwin C.

2017-01-01

ABSTRACT Branching morphogenesis underlies organogenesis in vertebrates and invertebrates, yet is incompletely understood. Here, we show that the sarco-endoplasmic reticulum Ca2+ reuptake pump (SERCA) directs budding across germ layers and species. Clonal knockdown demonstrated a cell-autonomous role for SERCA in Drosophila air sac budding. Live imaging of Drosophila tracheogenesis revealed elevated Ca2+ levels in migratory tip cells as they form branches. SERCA blockade abolished this Ca2+ differential, aborting both cell migration and new branching. Activating protein kinase C (PKC) rescued Ca2+ in tip cells and restored cell migration and branching. Likewise, inhibiting SERCA abolished mammalian epithelial budding, PKC activation rescued budding, while morphogens did not. Mesoderm (zebrafish angiogenesis) and ectoderm (Drosophila nervous system) behaved similarly, suggesting a conserved requirement for cell-autonomous Ca2+ signaling, established by SERCA, in iterative budding. PMID:28821490

Twenty years of embryonic stem cell research in farm animals

USDA-ARS?s Scientific Manuscript database

Notable distinctions between an embryonic stem cell (ESC) and somatic cell are that the ESC can maintain an undifferentiated state indefinitely, self renew, and is pluripotent, meaning that the ESC can potentially generate cells representing all the three primordial germ layers and contribute to the...

Metabolism of two Go alpha isoforms in neuronal cells during differentiation.

PubMed

Brabet, P; Pantaloni, C; Bockaert, J; Homburger, V

1991-07-15

We have previously shown that undifferentiated N1E-115 neuroblastoma cells express only one isoform of Go alpha (pI = 5.8), whereas differentiated neuroblastoma cells expressed, in addition to this isoform, another Go alpha with a more acidic pI (5.55). Moreover, primary cultures of cerebellar granule cells, which are extremely well differentiated cells yielding a high density of synapses, expressed only a single Go alpha isoform with a pI of 5.55 (Brabet, P., Pantaloni, C., Rodriguez Martinez, J., Bockaert, J., and Homburger, V. (1990) J. Neurochem. 54, 1310-1320). In this report, using biosynthetic labeling with [35S]methionine and specific quantitative immunoprecipitation with a polyclonal antibody raised against the purified Go alpha protein, we have determined 1) the degradation rate of total Go alpha (sum of the two isoforms) in differentiated as well as in undifferentiated neuroblastoma cells and in cerebellar granule cells, 2) the degradation rates of each isoform in differentiated neuroblastoma cells. The t 1/2 for total Go alpha protein degradation was very different in the three neuronal cell populations and was 28 +/- 5 h (n = 5), 58 +/- 9 h (n = 5), and 154 +/- 22 h (n = 6) in undifferentiated, differentiated neuroblastoma, and granule cells, respectively. Using two-dimensional gel analysis of immunoprecipitates, we have also determined the individual t 1/2 for degradation of each Go alpha isoform in differentiated neuroblastoma cells, in which the two Go alpha isoforms were expressed. Results indicated that the two Go alpha isoforms exhibit similar t1/2 for degradation (49 +/- 5 h, n = 3). Thus, the t1/2 for degradation of the more basic Go alpha isoform is higher in differentiated neuroblastoma cells (49 +/- 5 h, n = 3) than in undifferentiated neuroblastoma cells (28 +/- 5 h, n = 5) which expressed only the more basic Go alpha isoform. It can be concluded that the degradation rate of the more basic Go alpha isoform is not a characteristic of the protein itself but depends on the state of the cell differentiation. The comparison between the t1/2 for degradation of the more acidic Go alpha isoform is differentiated neuroblastoma cells (51 +/- 6 h, n = 3) with that of cerebellar granule cells (154 +/- 22 h, n = 6) suggests that there is also a decrease in the degradation rate of the more acidic Go alpha isoform during differentiation.(ABSTRACT TRUNCATED AT 400 WORDS)

Drosophila melanogaster--the model organism of choice for the complex biology of multi-cellular organisms

NASA Technical Reports Server (NTRS)

Beckingham, Kathleen M.; Armstrong, J. Douglas; Texada, Michael J.; Munjaal, Ravi; Baker, Dean A.

2005-01-01

Drosophila melanogaster has been intensely studied for almost 100 years. The sophisticated array of genetic and molecular tools that have evolved for analysis of gene function in this organism are unique. Further, Drosophila is a complex multi-cellular organism in which many aspects of development and behavior parallel those in human beings. These combined advantages have permitted research in Drosophila to make seminal contributions to the understanding of fundamental biological processes and ensure that Drosophila will continue to provide unique insights in the genomic era. An overview of the genetic methodologies available in Drosophila is given here, together with examples of outstanding recent contributions of Drosophila to our understanding of cell and organismal biology. The growing contribution of Drosophila to our knowledge of gravity-related responses is addressed.

Allocation of distinct organ fates from a precursor field requires a shift in expression and function of gene regulatory networks

PubMed Central

Zhu, Jinjin; Baker, Luke R.; Bashirullah, Arash

2018-01-01

A common occurrence in metazoan development is the rise of multiple tissues/organs from a single uniform precursor field. One example is the anterior forebrain of vertebrates, which produces the eyes, hypothalamus, diencephalon, and telencephalon. Another instance is the Drosophila wing disc, which generates the adult wing blade, the hinge, and the thorax. Gene regulatory networks (GRNs) that are comprised of signaling pathways and batteries of transcription factors parcel the undifferentiated field into discrete territories. This simple model is challenged by two observations. First, many GRN members that are thought to control the fate of one organ are actually expressed throughout the entire precursor field at earlier points in development. Second, each GRN can simultaneously promote one of the possible fates choices while repressing the other alternatives. It is therefore unclear how GRNs function to allocate tissue fates if their members are uniformly expressed and competing with each other within the same populations of cells. We address this paradigm by studying fate specification in the Drosophila eye-antennal disc. The disc, which begins its development as a homogeneous precursor field, produces a number of adult structures including the compound eyes, the ocelli, the antennae, the maxillary palps, and the surrounding head epidermis. Several selector genes that control the fates of the eye and antenna, respectively, are first expressed throughout the entire eye-antennal disc. We show that during early stages, these genes are tasked with promoting the growth of the entire field. Upon segregation to distinct territories within the disc, each GRN continues to promote growth while taking on the additional roles of promoting distinct primary fates and repressing alternate fates. The timing of both expression pattern restriction and expansion of functional duties is an elemental requirement for allocating fates within a single field. PMID:29351292

Human amniotic epithelial cell feeder layers maintain mouse embryonic stem cell pluripotency via epigenetic regulation of the c-Myc promoter.

PubMed

Liu, Te; Cheng, Weiwei; Liu, Tianjin; Guo, Lihe; Huang, Qin; Jiang, Lizhen; Du, Xiling; Xu, Fuhui; Liu, Zhixue; Lai, Dongmei

2010-02-01

Mouse embryonic stem cells (ESCs) are typically cultured on a feeder layer of mouse embryonic fibroblasts (MEFs), with leukemia inhibitory factor (LIF) added to maintain them in an undifferentiated state. We have previously shown that human amniotic epithelial cells (hAECs) can be used as feeder cells to maintain mouse ESC pluripotency, but the mechanism for this is unknown. In the present study, we found that CpG islands 5' of the c-Myc gene remain hypomethylated in mouse ESCs cultured on hAECs. In addition, levels of acetylation of histone H3 and trimethylation of histone H3K4 in the c-Myc gene promoter were higher in ES cells cultured on hAECs than those in ES cells cultured on MEFs. These data suggested that hAECs can alter mouse ESC gene expression via epigenetic modification of c-Myc, providing a possible mechanism for the hAEC-induced maintenance of ESCs in an undifferentiated state.

Donor Dependent Variations in Hematopoietic Differentiation among Embryonic and Induced Pluripotent Stem Cell Lines

PubMed Central

Féraud, Olivier; Valogne, Yannick; Melkus, Michael W.; Zhang, Yanyan; Oudrhiri, Noufissa; Haddad, Rima; Daury, Aurélie; Rocher, Corinne; Larbi, Aniya; Duquesnoy, Philippe; Divers, Dominique; Gobbo, Emilie; Brunet de la Grange, Philippe; Louache, Fawzia; Bennaceur-Griscelli, Annelise; Mitjavila-Garcia, Maria Teresa

2016-01-01

Hematopoiesis generated from human embryonic stem cells (ES) and induced pluripotent stem cells (iPS) are unprecedented resources for cell therapy. We compared hematopoietic differentiation potentials from ES and iPS cell lines originated from various donors and derived them using integrative and non-integrative vectors. Significant differences in differentiation toward hematopoietic lineage were observed among ES and iPS. The ability of engraftment of iPS or ES-derived cells in NOG mice varied among the lines with low levels of chimerism. iPS generated from ES cell-derived mesenchymal stem cells (MSC) reproduce a similar hematopoietic outcome compared to their parental ES cell line. We were not able to identify any specific hematopoietic transcription factors that allow to distinguish between good versus poor hematopoiesis in undifferentiated ES or iPS cell lines. There is a relatively unpredictable variation in hematopoietic differentiation between ES and iPS cell lines that could not be predicted based on phenotype or gene expression of the undifferentiated cells. These results demonstrate the influence of genetic background in variation of hematopoietic potential rather than the reprogramming process. PMID:26938212

Electrophysiological properties of prion-positive cardiac progenitors derived from murine embryonic stem cells.

PubMed

Fujii, Hiroshi; Ikeuchi, Yu; Kurata, Yasutaka; Ikeda, Nobuhito; Bahrudin, Udin; Li, Peili; Nakayama, Yuji; Endo, Ryo; Hasegawa, Akira; Morikawa, Kumi; Miake, Junichiro; Yoshida, Akio; Hidaka, Kyoko; Morisaki, Takayuki; Ninomiya, Haruaki; Shirayoshi, Yasuaki; Yamamoto, Kazuhiro; Hisatome, Ichiro

2012-01-01

The prion protein (PrP) has been reported to serve as a surface maker for isolation of cardiomyogenic progenitors from murine embryonic stem (ES) cells. Although PrP-positive cells exhibited automaticity, their electrophysiological characteristics remain unresolved. The aim of the present study was therefore to investigate the electrophysiological properties of PrP-positive cells in comparison with those of HCN4p-or Nkx2.5-positive cells. Differentiation of AB1, HCN5p-EGFP and hcgp7 ES cells into cardiac progenitors was induced by embryoid body (EB) formation. EBs were dissociated and cells expressing PrP, HCN4-EGFP and/or Nkx2.5-GFP were collected via flow cytometry. Sorted cells were subjected to reverse transcriptase-polymerase chain reaction, immunostaining and patch-clamp experiments. PrP-positive cells expressed mRNA of undifferentiation markers, first and second heart field markers, and cardiac-specific genes and ion channels, indicating their commitment to cardiomyogenic progenitors. PrP-positive cells with automaticity showed positive and negative chronotropic responses to isoproterenol and carbamylcholine, respectively. Hyperpolarization-activated cation current (I(f)) was barely detectable, whereas Na(+) and L-type Ca(2+) channel currents were frequently observed. Their spontaneous activity was slowed by inhibition of sarcoplasmic reticulum Ca(2+) uptake and release but not by blocking I(f). The maximum diastolic potential of their spontaneous firings was more depolarized than that of Nkx2.5-GFP-positive cells. PrP-positive cells contained cardiac progenitors that separated from the lineage of sinoatrial node cells. PrP can be used as a marker to enrich nascent cardiac progenitors.

Axons guided by insulin receptor in Drosophila visual system.

PubMed

Song, Jianbo; Wu, Lingling; Chen, Zun; Kohanski, Ronald A; Pick, Leslie

2003-04-18

Insulin receptors are abundant in the central nervous system, but their roles remain elusive. Here we show that the insulin receptor functions in axon guidance. The Drosophila insulin receptor (DInR) is required for photoreceptor-cell (R-cell) axons to find their way from the retina to the brain during development of the visual system. DInR functions as a guidance receptor for the adapter protein Dock/Nck. This function is independent of Chico, the Drosophila insulin receptor substrate (IRS) homolog.

Combination Chemotherapy and Peripheral Stem Cell Transplantation in Treating Patients With Stage III Ovarian Cancer

ClinicalTrials.gov

2017-08-08

Malignant Ovarian Mixed Epithelial Tumor; Ovarian Clear Cell Cystadenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Ovarian Mucinous Cystadenocarcinoma; Ovarian Serous Cystadenocarcinoma; Primary Peritoneal Carcinoma; Stage III Ovarian Cancer; Undifferentiated Ovarian Carcinoma

The clathrin-binding motif and the J-domain of Drosophila Auxilin are essential for facilitating Notch ligand endocytosis

PubMed Central

Kandachar, Vasundhara; Bai, Ting; Chang, Henry C

2008-01-01

Background Ligand endocytosis plays a critical role in regulating the activity of the Notch pathway. The Drosophila homolog of auxilin (dAux), a J-domain-containing protein best known for its role in the disassembly of clathrin coats from clathrin-coated vesicles, has recently been implicated in Notch signaling, although its exact mechanism remains poorly understood. Results To understand the role of auxilin in Notch ligand endocytosis, we have analyzed several point mutations affecting specific domains of dAux. In agreement with previous work, analysis using these stronger dAux alleles shows that dAux is required for several Notch-dependent processes, and its function during Notch signaling is required in the signaling cells. In support of the genetic evidences, the level of Delta appears elevated in dAux deficient cells, suggesting that the endocytosis of Notch ligand is disrupted. Deletion analysis shows that the clathrin-binding motif and the J-domain, when over-expressed, are sufficient for rescuing dAux phenotypes, implying that the recruitment of Hsc70 to clathrin is a critical role for dAux. However, surface labeling experiment shows that, in dAux mutant cells, Delta accumulates at the cell surface. In dAux mutant cells, clathrin appears to form large aggregates, although Delta is not enriched in these aberrant clathrin-positive structures. Conclusion Our data suggest that dAux mutations inhibit Notch ligand internalization at an early step during clathrin-mediated endocytosis, before the disassembly of clathrin-coated vesicles. Further, the inhibition of ligand endocytosis in dAux mutant cells possibly occurs due to depletion of cytosolic pools of clathrin via the formation of clathrin aggregates. Together, our observations argue that ligand endocytosis is critical for Notch signaling and auxilin participates in Notch signaling by facilitating ligand internalization. PMID:18466624

Live Imaging of Glial Cell Migration in the Drosophila Eye Imaginal Disc

PubMed Central

Cafferty, Patrick; Xie, Xiaojun; Browne, Kristen; Auld, Vanessa J.

2009-01-01

Glial cells of both vertebrate and invertebrate organisms must migrate to final target regions in order to ensheath and support associated neurons. While recent progress has been made to describe the live migration of glial cells in the developing pupal wing (1), studies of Drosophila glial cell migration have typically involved the examination of fixed tissue. Live microscopic analysis of motile cells offers the ability to examine cellular behavior throughout the migratory process, including determining the rate of and changes in direction of growth. Paired with use of genetic tools, live imaging can be used to determine more precise roles for specific genes in the process of development. Previous work by Silies et al. (2) has described the migration of glia originating from the optic stalk, a structure that connects the developing eye and brain, into the eye imaginal disc in fixed tissue. Here we outline a protocol for examining the live migration of glial cells into the Drosophila eye imaginal disc. We take advantage of a Drosophila line that expresses GFP in developing glia to follow glial cell progression in wild type and in mutant animals. PMID:19590493

Autophagy as a trigger for cell death: autophagic degradation of inhibitor of apoptosis dBruce controls DNA fragmentation during late oogenesis in Drosophila.

PubMed

Nezis, Ioannis P; Shravage, Bhupendra V; Sagona, Antonia P; Johansen, Terje; Baehrecke, Eric H; Stenmark, Harald

2010-11-01

Autophagy has been reported to contribute to cell death, but the underlying mechanisms remain largely unknown and controversial. We have: been studying oogenesis in Drosophila melanogaster as a model system to understand the interplay between autophagy and cell death. Using a novel autophagy reporter we found that autophagy occurs during developmental cell death of nurse cells in late oogenesis. Genetic inhibition: of autophagy-related genes atg1, atg13 and vps34 results in late-stage egg chambers containing persisting nurse cell nuclei without fragmented DNA and attenuation of caspase-3 cleavage. We found that Drosophila inhibitor of apoptosis dBruce is degraded by autophagy and this degradation promotes DNA fragmentation and subsequent nurse cell death. These studies demonstrate that autophagic degradation of an inhibitor: of apoptosis is a novel mechanism of triggering cell death.

Definition of Drosophila hemocyte subsets by cell-type specific antigens.

PubMed

Kurucz, Eva; Váczi, B; Márkus, R; Laurinyecz, Barbara; Vilmos, P; Zsámboki, J; Csorba, Kinga; Gateff, Elisabeth; Hultmark, D; Andó, I

2007-01-01

We analyzed the heterogeneity of Drosophila hemocytes on the basis of the expression of cell-type specific antigens. The antigens characterize distinct subsets which partially overlap with those defined by morphological criteria. On the basis of the expression or the lack of expression of blood cell antigens the following hemocyte populations have been defined: crystal cells, plasmatocytes, lamellocytes and precursor cells. The expression of the antigens and thus the different cell types are developmentally regulated. The hemocytes are arranged in four main compartments: the circulating blood cells, the sessile tissue, the lymph glands and the posterior hematopoietic tissue. Each hemocyte compartment has a specific and characteristic composition of the various cell types. The described markers represent the first successful attempt to define hemocyte lineages by immunological markers in Drosophila and help to define morphologically, functionally, spatially and developmentally distinct subsets of hemocytes.

Drosophila heart cell movement to the midline occurs through both cell autonomous migration and dorsal closure.

PubMed

Haack, Timm; Schneider, Matthias; Schwendele, Bernd; Renault, Andrew D

2014-12-15

The Drosophila heart is a linear organ formed by the movement of bilaterally specified progenitor cells to the midline and adherence of contralateral heart cells. This movement occurs through the attachment of heart cells to the overlying ectoderm which is undergoing dorsal closure. Therefore heart cells are thought to move to the midline passively. Through live imaging experiments and analysis of mutants that affect the speed of dorsal closure we show that heart cells in Drosophila are autonomously migratory and part of their movement to the midline is independent of the ectoderm. This means that heart formation in flies is more similar to that in vertebrates than previously thought. We also show that defects in dorsal closure can result in failure of the amnioserosa to properly degenerate, which can physically hinder joining of contralateral heart cells leading to a broken heart phenotype. Copyright © 2014 Elsevier Inc. All rights reserved.

Pre-differentiation of human neural stem cells into GABAergic neurons prior to transplant results in greater repopulation of the damaged brain and accelerates functional recovery after transient ischemic stroke.

PubMed

Abeysinghe, Hima C S; Bokhari, Laita; Quigley, Anita; Choolani, Mahesh; Chan, Jerry; Dusting, Gregory J; Crook, Jeremy M; Kobayashi, Nao R; Roulston, Carli L

2015-09-29

Despite attempts to prevent brain injury during the hyperacute phase of stroke, most sufferers end up with significant neuronal loss and functional deficits. The use of cell-based therapies to recover the injured brain offers new hope. In the current study, we employed human neural stem cells (hNSCs) isolated from subventricular zone (SVZ), and directed their differentiation into GABAergic neurons followed by transplantation to ischemic brain. Pre-differentiated GABAergic neurons, undifferentiated SVZ-hNSCs or media alone were stereotaxically transplanted into the rat brain (n=7/group) 7 days after endothelin-1 induced stroke. Neurological outcome was assessed by neurological deficit scores and the cylinder test. Transplanted cell survival, cellular phenotype and maturation were assessed using immunohistochemistry and confocal microscopy. Behavioral assessments revealed accelerated improvements in motor function 7 days post-transplant in rats treated with pre-differentiated GABAergic cells in comparison to media alone and undifferentiated hNSC treated groups. Histopathology 28 days-post transplant indicated that pre-differentiated cells maintained their GABAergic neuronal phenotype, showed evidence of synaptogenesis and up-regulated expression of both GABA and calcium signaling proteins associated with neurotransmission. Rats treated with pre-differentiated cells also showed increased neurogenic activity within the SVZ at 28 days, suggesting an additional trophic role of these GABAergic cells. In contrast, undifferentiated SVZ-hNSCs predominantly differentiated into GFAP-positive astrocytes and appeared to be incorporated into the glial scar. Our study is the first to show enhanced exogenous repopulation of a neuronal phenotype after stroke using techniques aimed at GABAergic cell induction prior to delivery that resulted in accelerated and improved functional recovery.

DNMT1 maintains progenitor function in self-renewing somatic tissue.

PubMed

Sen, George L; Reuter, Jason A; Webster, Daniel E; Zhu, Lilly; Khavari, Paul A

2010-01-28

Progenitor cells maintain self-renewing tissues throughout life by sustaining their capacity for proliferation while suppressing cell cycle exit and terminal differentiation. DNA methylation provides a potential epigenetic mechanism for the cellular memory needed to preserve the somatic progenitor state through repeated cell divisions. DNA methyltransferase 1 (DNMT1) maintains DNA methylation patterns after cellular replication. Although dispensable for embryonic stem cell maintenance, the role for DNMT1 in maintaining the progenitor state in constantly replenished somatic tissues, such as mammalian epidermis, is unclear. Here we show that DNMT1 is essential for epidermal progenitor cell function. DNMT1 protein was found enriched in undifferentiated cells, where it was required to retain proliferative stamina and suppress differentiation. In tissue, DNMT1 depletion led to exit from the progenitor cell compartment, premature differentiation and eventual tissue loss. Genome-wide analysis showed that a significant portion of epidermal differentiation gene promoters were methylated in self-renewing conditions but were subsequently demethylated during differentiation. Furthermore, UHRF1 (refs 9, 10), a component of the DNA methylation machinery that targets DNMT1 to hemi-methylated DNA, is also necessary to suppress premature differentiation and sustain proliferation. In contrast, Gadd45A and B, which promote active DNA demethylation, are required for full epidermal differentiation gene induction. These data demonstrate that proteins involved in the dynamic regulation of DNA methylation patterns are required for progenitor maintenance and self-renewal in mammalian somatic tissue.

Intensity-Modulated or Proton Radiation Therapy for Sinonasal Malignancy

ClinicalTrials.gov

2018-02-13

Adenoid Cystic Carcinoma; Squamous Cell Carcinoma; Sinonasal Carcinoma; Sinonasal Undifferentiated Carcinoma; Mucoepidermoid Carcinoma; Schneiderian Carcinoma; Myoepithelial Carcinoma; Esthesioneuroblastoma; Melanoma

Fipronil induces apoptosis through caspase-dependent mitochondrial pathways in Drosophila S2 cells.

PubMed

Zhang, Baoyan; Xu, Zhiping; Zhang, Yixi; Shao, Xusheng; Xu, Xiaoyong; Cheng, Jiaogao; Li, Zhong

2015-03-01

Fipronil is the first phenylpyrazole insecticide widely used in controlling pests, including pyrethroid, organophosphate and carbamate insecticides. It is generally accepted that fipronil elicits neurotoxicity via interactions with GABA and glutamate receptors, although alternative mechanisms have recently been proposed. This study evaluates the genotoxicity of fipronil and its likely mode of action in Drosophila S2 cells, as an in vitro model. Fipronil administrated the concentration- and time-dependent S2 cell proliferation. Intracellular biochemical assays showed that fipronil-induced S2 cell apoptosis coincided with a decrease in the mitochondrial membrane potential and an increase reactive oxygen species generation, a significant decrease of Bcl-2 and DIAP1, and a marked augmentation of Cyt c and caspase-3. Because caspase-3 is the major executioner caspase downstream of caspase-9 in Drosophila, enzyme activity assays were used to determine the activities of caspase-3 and caspase-9. Our results indicated that fipronil effectively induced apoptosis in Drosophila S2 cells through caspase-dependent mitochondrial pathways. Copyright © 2015 Elsevier Inc. All rights reserved.

The L1-CAM, Neuroglian, functions in glial cells for Drosophila antennal lobe development.

PubMed

Chen, Weitao; Hing, Huey

2008-07-01

Although considerable progress has been made in understanding the roles of olfactory receptor neurons (ORNs) and projection neurons (PNs) in Drosophila antennal lobe (AL) development, the roles of glia have remained largely mysterious. Here, we show that during Drosophila metamorphosis, a population of midline glial cells in the brain undergoes extensive cellular remodeling and is closely associated with the collateral branches of ORN axons. These glial cells are required for ORN axons to project across the midline and establish the contralateral wiring in the ALs. We find that Neuroglian (Nrg), the Drosophila homolog of the vertebrate cell adhesion molecule, L1, is expressed and functions in the midline glial cells to regulate their proper development. Loss of Nrg causes the disruption in glial morphology and the agenesis of the antennal commissural tract. Our genetic analysis further demonstrates that the functions of Nrg in the midline glia require its ankyrin-binding motif. We propose that Nrg is an important regulator of glial morphogenesis and axon guidance in AL development. (Copyright) 2008 Wiley Periodicals, Inc.

Specification of anteroposterior cell fates in Caenorhabditis elegans by Drosophila Hox proteins.

PubMed

Hunter, C P; Kenyon, C

1995-09-21

Antennapedia class homeobox (Hox) genes specify cell fates in successive anteroposterior body domains in vertebrates, insects and nematodes. The DNA-binding homeodomain sequences are very similar between vertebrate and Drosophila Hox proteins, and this similarity allows vertebrate Hox proteins to function in Drosophila. In contrast, the Caenorhabditis elegans homeodomains are substantially divergent. Further, C. elegans differs from both insects and vertebrates in having a non-segmented body as well as a distinctive mode of development that involves asymmetric early cleavages and invariant cell lineages. Here we report that, despite these differences, Drosophila Hox proteins expressed in C. elegans can substitute for C. elegans Hox proteins in the control of three different cell-fate decisions: the regulation of cell migration, the specification of serotonergic neurons, and the specification of a sensory structure. We also show that the specificity of one C. elegans Hox protein is partly determined by two amino acids that have been implicated in sequence-specific DNA binding. Together these findings suggest that factors important for target recognition by specific Hox proteins have been conserved throughout much of the animal kingdom.

[Incidence of anaplastic tumor in structure of other histologic forms of the thyroid gland cancer].

PubMed

Vinnik, Iu A; Gorbenko, V N; Vas'ko, A R; Kikhtenko, E V; Gargin, V V

2014-01-01

The degrees of invasiveness, proliferative activity, morphofunctional activity of nuclei in the thyroidal gland tumors were studied, while analyzing material, obtained in 1343 patients, suffering thyroidal gland cancer (THGC) and operated on in 2000-2013 yrs. Morphological point quantity of malignancy (as a criterion of the tumor progression grade) and mitotic activity in cellular population were determined in various kinds of THGC. Undifferentiated (anaplastic carcinoma) type of THGC is the most malignant one. There were determined a spindle-like, giant-cell and squamous-cell forms of undifferentiated THGC. The presence of sites of differentiated cancer in 33% of histological preparations witnesses the interrelationship with the earlier existed pathological process.

Use of electron microscopy to classify canine perivascular wall tumors.

PubMed

Palmieri, C; Avallone, G; Cimini, M; Roccabianca, P; Stefanello, D; Della Salda, L

2013-03-01

The histologic classification of canine perivascular wall tumors (PWTs) is controversial. Many PWTs are still classified as hemangiopericytomas (HEPs), and the distinction from peripheral nerve sheath tumors (PNSTs) is still under debate. A recent histologic classification of canine soft tissue sarcomas included most histologic types of PWT but omitted those that were termed undifferentiated. Twelve cases of undifferentiated canine PWTs were evaluated by transmission electron microscopy. The ultrastructural findings supported a perivascular wall origin for all cases with 4 categories of differentiation: myopericytic (n = 4), myofibroblastic (n = 1), fibroblastic (n = 2), and undifferentiated (n = 5). A PNST was considered unlikely in each case based on immunohistochemical expression of desmin and/or the lack of typical ultrastructural features, such as basal lamina. Electron microscopy was pivotal for the subclassification of canine PWTs, and the results support the hypothesis that canine PWTs represent a continuum paralleling the phenotypic plasticity of vascular mural cells. The hypothesis that a subgroup of PWTs could arise from a pluripotent mesenchymal perivascular wall cell was also considered and may explain the diverse differentiation of canine PWTs.

Adoptive TReg Cell for Suppression of aGVHD After UCB HSCT for Heme Malignancies

ClinicalTrials.gov

2018-03-26

Acute Lymphoblastic Leukemia; Burkitt Lymphoma; Natural Killer Cell Malignancies; Chronic Myelogenous Leukemia; Myelodysplastic Syndromes; Large-cell Lymphoma; Chronic Lymphocytic Leukemia; Small Lymphocytic Lymphoma; Marginal Zone B-Cell Lymphoma; Follicular Lymphoma; Lymphoplasmacytic Lymphoma; Mantle-Cell Lymphoma; Prolymphocytic Leukemia; Hodgkin Lymphoma; Multiple Myeloma; Acute Myelogenous Leukemia; Biphenotypic Leukemia; Undifferentiated Leukemia

vasa is expressed in somatic cells of the embryonic gonad in a sex-specific manner in Drosophila melanogaster.

PubMed

Renault, Andrew D

2012-10-15

Vasa is a DEAD box helicase expressed in the Drosophila germline at all stages of development. vasa homologs are found widely in animals and vasa has become the gene of choice in identifying germ cells. I now show that Drosophila vasa expression is not restricted to the germline but is also expressed in a somatic lineage, the embryonic somatic gonadal precursor cells. This expression is sexually dimorphic, being maintained specifically in males, and is regulated post-transcriptionally. Although somatic Vasa expression is not required for gonad coalescence, these data support the notion that Vasa is not solely a germline factor.

The Cell-Surface N-Glycome of Human Embryonic Stem Cells and Differentiated Hepatic Cells thereof.

PubMed

Montacir, Houda; Freyer, Nora; Knöspel, Fanny; Urbaniak, Thomas; Dedova, Tereza; Berger, Markus; Damm, Georg; Tauber, Rudolf; Zeilinger, Katrin; Blanchard, Véronique

2017-07-04

Human embryonic stem cells (hESCs) are pluripotent stem cells that offer a wide range of applications in regenerative medicine. In addition, they have been proposed as an appropriate alternative source of hepatocytes. In this work, hESCs were differentiated into definitive endodermal cells (DECs), followed by maturation into hepatocyte-like cells (HLCs). Their cell-surface N-glycome was profiled and also compared with that of primary human hepatocytes (PHHs). Undifferentiated hESCs contained large amounts of high-mannose N-glycans. In contrast, complex-type N-glycans such as asialylated or monosialylated biantennary and triantennary N-glycans were dominant in HLCs, and fully galactosylated structures were significantly more abundant than in undifferentiated hESCs. The cell-surface N-glycosylation of PHHs was more biologically processed than that of HLCs, with bisialylated biantennary and trisialylated triantennary structures predominant. This is the first report of the cell surface N-glycome of PHHs and of HLCs being directly generated from hESCs without embryoid body formation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mice cloned from skin cells.

PubMed

Li, Jinsong; Greco, Valentina; Guasch, Géraldine; Fuchs, Elaine; Mombaerts, Peter

2007-02-20

Adult stem cells represent unique populations of undifferentiated cells with self-renewal capacity. In many tissues, stem cells divide less often than their progeny. It has been widely speculated, but largely untested, that their undifferentiated and quiescent state may make stem cells more efficient as donors for cloning by nuclear transfer (NT). Here, we report the use of nuclei from hair follicle stem cells and other skin keratinocytes as NT donors. When keratinocyte stem cells (KSCs) were used as NT donors, 19 liveborn mice were obtained, 9 of which survived to adulthood. Embryonic keratinocytes and cumulus cells also gave rise to cloned mice. Although cloning efficiencies were similar (<6% per transferred blastocyst), success rates were consistently higher for males than for females. Adult keratinocyte stem cells were better NT donors than so-called transit amplifying (TA) keratinocytes in both sexes (1.6% vs. 0% in females and 5.4% vs. 2.8% in males). Our findings reveal skin as a source of readily accessible stem cells, the nuclei of which can be reprogrammed to the pluripotent state by exposure to the cytoplasm of unfertilized oocytes.

Ankrd6 is a mammalian functional homolog of Drosophila planar cell polarity gene diego and regulates coordinated cellular orientation in the mouse inner ear.

PubMed

Jones, Chonnettia; Qian, Dong; Kim, Sun Myoung; Li, Shuangding; Ren, Dongdong; Knapp, Lindsey; Sprinzak, David; Avraham, Karen B; Matsuzaki, Fumio; Chi, Fanglu; Chen, Ping

2014-11-01

The coordinated polarization of neighboring cells within the plane of the tissue, known as planar cell polarity (PCP), is a recurring theme in biology. It is required for numerous developmental processes for the form and function of many tissues and organs across species. The genetic pathway regulating PCP was first discovered in Drosophila, and an analogous but distinct pathway is emerging in vertebrates. It consists of membrane protein complexes known as core PCP proteins that are conserved across species. Here we report that the over-expression of the murine Ankrd6 (mAnkrd6) gene that shares homology with Drosophila core PCP gene diego causes a typical PCP phenotype in Drosophila, and mAnkrd6 can rescue the loss of function of diego in Drosophila. In mice, mAnkrd6 protein is asymmetrically localized in cells of the inner ear sensory organs, characteristic of components of conserved core PCP complexes. The loss of mAnkrd6 causes PCP defects in the inner ear sensory organs. Moreover, canonical Wnt signaling is significantly increased in mouse embryonic fibroblasts from mAnkrd6 knockout mice in comparison to wild type controls. Together, these results indicated that mAnkrd6 is a functional homolog of the Drosophila diego gene for mammalian PCP regulation and act to suppress canonical Wnt signaling. Copyright © 2014 Elsevier Inc. All rights reserved.

Transcriptome analysis reveals differentially expressed genes associated with germ cell and gonad development in the Southern bluefin tuna (Thunnus maccoyii).

PubMed

Bar, Ido; Cummins, Scott; Elizur, Abigail

2016-03-10

Controlling and managing the breeding of bluefin tuna (Thunnus spp.) in captivity is an imperative step towards obtaining a sustainable supply of these fish in aquaculture production systems. Germ cell transplantation (GCT) is an innovative technology for the production of inter-species surrogates, by transplanting undifferentiated germ cells derived from a donor species into larvae of a host species. The transplanted surrogates will then grow and mature to produce donor-derived seed, thus providing a simpler alternative to maintaining large-bodied broodstock such as the bluefin tuna. Implementation of GCT for new species requires the development of molecular tools to follow the fate of the transplanted germ cells. These tools are based on key reproductive and germ cell-specific genes. RNA-Sequencing (RNA-Seq) provides a rapid, cost-effective method for high throughput gene identification in non-model species. This study utilized RNA-Seq to identify key genes expressed in the gonads of Southern bluefin tuna (Thunnus maccoyii, SBT) and their specific expression patterns in male and female gonad cells. Key genes involved in the reproductive molecular pathway and specifically, germ cell development in gonads, were identified using analysis of RNA-Seq transcriptomes of male and female SBT gonad cells. Expression profiles of transcripts from ovary and testis cells were compared, as well as testis germ cell-enriched fraction prepared with Percoll gradient, as used in GCT studies. Ovary cells demonstrated over-expression of genes related to stem cell maintenance, while in testis cells, transcripts encoding for reproduction-associated receptors, sex steroids and hormone synthesis and signaling genes were over-expressed. Within the testis cells, the Percoll-enriched fraction showed over-expression of genes that are related to post-meiosis germ cell populations. Gonad development and germ cell related genes were identified from SBT gonads and their expression patterns in ovary and testis cells were determined. These expression patterns correlate with the reproductive developmental stage of the sampled fish. The majority of the genes described in this study were sequenced for the first time in T. maccoyii. The wealth of SBT gonadal and germ cell-related gene sequences made publicly available by this study provides an extensive resource for further GCT and reproductive molecular biology studies of this commercially valuable fish.

Differentiation of neuroblastoma cell line N1E-115 involves several signaling cascades.

PubMed

Oh, Ji-eun; Karlmark, Karlin Raja; Shin, Joo-ho; Pollak, Arnold; Freilinger, Angelika; Hengstschläger, Markus; Lubec, Gert

2005-03-01

No systematic searches for differential expression of signaling proteins (SP) in undifferentiated vs. differentiated cell lineages were published and herein we used protein profiling for this purpose. The NIE-115 cell line was cultivated and an aliquot was differentiated with dimethylsulfoxide (DMSO), that is known to lead to a neuronal phenotype. Cell lysates were prepared, run on two-dimensional gel electrophoresis followed by MALDI-TOF-TOF identification of proteins and maps of identified SPs were generated. Seven SPs were comparable, 27 SPs: GTP-binding/Ras-related proteins, kinases, growth factors, calcium binding proteins, phosphatase-related proteins were observed in differentiated NIE-115 cells and eight SPs of the groups mentioned above were observed in undifferentiated cells only. Switching-on/off of several individual SPs from different signaling cascades during the differentiation process is a key to understand mechanisms involved. The findings reported herein are challenging in vitro and in vivo studies to confirm a functional role for deranged SPs.

Osteopontin is a Novel Marker of Pancreatic Ductal Tissues and of Undifferentiated Pancreatic Precursors in Mice

PubMed Central

Kilic, Gamze; Wang, Junfeng; Sosa-Pineda, Beatriz

2008-01-01

Matricellular proteins mediate both tissue morphogenesis and tissue homeostasis in important ways because they modulate cell-matrix and cell-cell interactions. In this study, we found that the matricellular protein osteopontin (Opn) is a novel marker of undifferentiated pancreatic precursors and pancreatic ductal tissues in mice. Our analysis also underscored a specific, dynamic profile of Opn expression in embryonic pancreatic tissues that suggests the participation of this protein’s function in processes involving cell migration, cell-cell interactions, or both. Surprisingly, our analysis of Opn-deficient pancreata did not reveal obvious alterations in the morphology or differentiation of these tissues. Therefore, in embryonic pancreatic tissues, it is possible that other proteins act redundantly to Opn or that this protein’s function is dispensable for pancreas development. Finally, the maintenance of Opn expression in pancreatic tissues of adults argues for a possible function of this protein in injury and pathologic responses. PMID:16518820

Notch3-Jagged signaling controls the pool of undifferentiated airway progenitors

PubMed Central

Mori, Munemasa; Mahoney, John E.; Stupnikov, Maria R.; Paez-Cortez, Jesus R.; Szymaniak, Aleksander D.; Varelas, Xaralabos; Herrick, Dan B.; Schwob, James; Zhang, Hong; Cardoso, Wellington V.

2015-01-01

Basal cells are multipotent airway progenitors that generate distinct epithelial cell phenotypes crucial for homeostasis and repair of the conducting airways. Little is known about how these progenitor cells expand and transition to differentiation to form the pseudostratified airway epithelium in the developing and adult lung. Here, we show by genetic and pharmacological approaches that endogenous activation of Notch3 signaling selectively controls the pool of undifferentiated progenitors of upper airways available for differentiation. This mechanism depends on the availability of Jag1 and Jag2, and is key to generating a population of parabasal cells that later activates Notch1 and Notch2 for secretory-multiciliated cell fate selection. Disruption of this mechanism resulted in aberrant expansion of basal cells and altered pseudostratification. Analysis of human lungs showing similar abnormalities and decreased NOTCH3 expression in subjects with chronic obstructive pulmonary disease suggests an involvement of NOTCH3-dependent events in the pathogenesis of this condition. PMID:25564622

YKL-40 in Serum Samples From Patients With Newly Diagnosed Stage III-IV Ovarian Epithelial, Primary Peritoneal Cavity, or Fallopian Tube Cancer Receiving Chemotherapy

ClinicalTrials.gov

2018-05-21

Fallopian Tube Adenocarcinoma; Fallopian Tube Clear Cell Adenocarcinoma; Fallopian Tube Endometrioid Adenocarcinoma; Fallopian Tube Mucinous Adenocarcinoma; Fallopian Tube Serous Adenocarcinoma; Fallopian Tube Transitional Cell Carcinoma; Malignant Ovarian Brenner Tumor; Malignant Ovarian Clear Cell Tumor; Malignant Ovarian Endometrioid Tumor; Malignant Ovarian Mixed Epithelial Tumor; Malignant Ovarian Mucinous Tumor; Malignant Ovarian Neoplasm; Malignant Ovarian Serous Tumor; Malignant Ovarian Transitional Cell Tumor; Ovarian Adenocarcinoma; Primary Peritoneal Serous Adenocarcinoma; Stage IIIA Fallopian Tube Cancer; Stage IIIA Ovarian Cancer; Stage IIIA Primary Peritoneal Cancer; Stage IIIB Fallopian Tube Cancer; Stage IIIB Ovarian Cancer; Stage IIIB Primary Peritoneal Cancer; Stage IIIC Fallopian Tube Cancer; Stage IIIC Ovarian Cancer; Stage IIIC Primary Peritoneal Cancer; Stage IV Fallopian Tube Cancer; Stage IV Ovarian Cancer; Stage IV Primary Peritoneal Cancer; Undifferentiated Fallopian Tube Carcinoma; Undifferentiated Ovarian Carcinoma

Increased oxidative stress and antioxidant expression in mouse keratinocytes following exposure to paraquat

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

Black, Adrienne T.; Gray, Joshua P.; Shakarjian, Michael P.

Paraquat (1,1'-dimethyl-4,4'-bipyridinium) is a widely used herbicide known to induce skin toxicity. This is thought to be due to oxidative stress resulting from the generation of cytotoxic reactive oxygen intermediates (ROI) during paraquat redox cycling. The skin contains a diverse array of antioxidant enzymes which protect against oxidative stress including superoxide dismutase (SOD), catalase, glutathione peroxidase-1 (GPx-1), heme oxygenase-1 (HO-1), metallothionein-2 (MT-2), and glutathione-S-transferases (GST). In the present studies we compared paraquat redox cycling in primary cultures of undifferentiated and differentiated mouse keratinocytes and determined if this was associated with oxidative stress and altered expression of antioxidant enzymes. We foundmore » that paraquat readily undergoes redox cycling in both undifferentiated and differentiated keratinocytes, generating superoxide anion and hydrogen peroxide as well as increased protein oxidation which was greater in differentiated cells. Paraquat treatment also resulted in increased expression of HO-1, Cu,Zn-SOD, catalase, GSTP1, GSTA3 and GSTA4. However, no major differences in expression of these enzymes were evident between undifferentiated and differentiated cells. In contrast, expression of GSTA1-2 was significantly greater in differentiated relative to undifferentiated cells after paraquat treatment. No changes in expression of MT-2, Mn-SOD, GPx-1, GSTM1 or the microsomal GST's mGST1, mGST2 and mGST3, were observed in response to paraquat. These data demonstrate that paraquat induces oxidative stress in keratinocytes leading to increased expression of antioxidant genes. These intracellular proteins may be important in protecting the skin from paraquat-mediated cytotoxicity.« less

Stage-specific expression of DDX4 and c-kit at different developmental stages of the porcine testis.

PubMed

Lee, Ran; Lee, Won-Young; Park, Hyun-Jung; Ha, Woo-Tae; Woo, Jae-Seok; Chung, Hak-Jae; Lee, Ji-Heon; Hong, Kwonho; Song, Hyuk

2018-03-01

Spermatogenesis begins with spermatogonial stem cells (SSCs), which are located in the basement membrane of the adult testes. Previous studies have described specific biomarkers for undifferentiated porcine spermatogonia or SSCs; however, these markers are not sufficient to understand spermatogenesis at different developmental stages. The objective of this study was characterize the expression of DEAD-Box polypeptide 4 (DDX4, also known as VASA) and tyrosine-protein kinase kit (c-kit), as potential markers of male germ cells in the porcine testis. In porcine testis tissue at prepubertal stages (5, 30, and 60 days), DDX4 and c-kit protein expression was detected in the most undifferentiated spermatogonia, which also express protein gene product 9.5 (PGP9.5). However, in porcine testis tissues from pubertal and postpubertal stages (90, 120, and 150 days), DDX4 and c-kit were not detected in PGP9.5-positive undifferentiated spermatogonia. The DDX4 expression pattern was similar to that of c-kit in the porcine testis. In adult porcine testes, DDX4-expressing cells were located on the lumenal side, compared to synaptonemal complex protein 3-positive primary spermatocytes, but DDX-4 was not co-expressed with acrosin, a known acrosome marker. In addition, DDX4 was detected in PGP9.5-expressing porcine SSCs in culture. Based on our results, we suggest that DDX4 and c-kit are putative markers of undifferentiated spermatogonia in the prepubertal porcine testis. While in the postpubertal porcine testis, they are markers of differentiated spermatocytes. These findings may facilitate future studies of porcine spermatogenesis. Copyright © 2018 Elsevier B.V. All rights reserved.

Live imaging using a FRET glucose sensor reveals glucose delivery to all cell types in the Drosophila brain.

PubMed

Volkenhoff, Anne; Hirrlinger, Johannes; Kappel, Johannes M; Klämbt, Christian; Schirmeier, Stefanie

2018-04-01

All complex nervous systems are metabolically separated from circulation by a blood-brain barrier (BBB) that prevents uncontrolled leakage of solutes into the brain. Thus, all metabolites needed to sustain energy homeostasis must be transported across this BBB. In invertebrates, such as Drosophila, the major carbohydrate in circulation is the disaccharide trehalose and specific trehalose transporters are expressed by the glial BBB. Here we analyzed whether glucose is able to contribute to energy homeostasis in Drosophila. To study glucose influx into the brain we utilized a genetically encoded, FRET-based glucose sensor expressed in a cell type specific manner. When confronted with glucose all brain cells take up glucose within two minutes. In order to characterize the glucose transporter involved, we studied Drosophila Glut1, the homologue of which is primarily expressed by the BBB-forming endothelial cells and astrocytes in the mammalian nervous system. In Drosophila, however, Glut1 is expressed in neurons and is not found at the BBB. Thus, Glut1 cannot contribute to initial glucose uptake from the hemolymph. To test whether gap junctional coupling between the BBB forming cells and other neural cells contributes to glucose distribution we assayed these junctions using RNAi experiments and only found a minor contribution of gap junctions to glucose metabolism. Our results provide the entry point to further dissect the mechanisms underlying glucose distribution and offer new opportunities to understand brain metabolism. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Cohesion Protein SOLO Associates with SMC1 and Is Required for Synapsis, Recombination, Homolog Bias and Cohesion and Pairing of Centromeres in Drosophila Meiosis

PubMed Central

Yan, Rihui; McKee, Bruce D.

2013-01-01

Cohesion between sister chromatids is mediated by cohesin and is essential for proper meiotic segregation of both sister chromatids and homologs. solo encodes a Drosophila meiosis-specific cohesion protein with no apparent sequence homology to cohesins that is required in male meiosis for centromere cohesion, proper orientation of sister centromeres and centromere enrichment of the cohesin subunit SMC1. In this study, we show that solo is involved in multiple aspects of meiosis in female Drosophila. Null mutations in solo caused the following phenotypes: 1) high frequencies of homolog and sister chromatid nondisjunction (NDJ) and sharply reduced frequencies of homolog exchange; 2) reduced transmission of a ring-X chromosome, an indicator of elevated frequencies of sister chromatid exchange (SCE); 3) premature loss of centromere pairing and cohesion during prophase I, as indicated by elevated foci counts of the centromere protein CID; 4) instability of the lateral elements (LE)s and central regions of synaptonemal complexes (SCs), as indicated by fragmented and spotty staining of the chromosome core/LE component SMC1 and the transverse filament protein C(3)G, respectively, at all stages of pachytene. SOLO and SMC1 are both enriched on centromeres throughout prophase I, co-align along the lateral elements of SCs and reciprocally co-immunoprecipitate from ovarian protein extracts. Our studies demonstrate that SOLO is closely associated with meiotic cohesin and required both for enrichment of cohesin on centromeres and stable assembly of cohesin into chromosome cores. These events underlie and are required for stable cohesion of centromeres, synapsis of homologous chromosomes, and a recombination mechanism that suppresses SCE to preferentially generate homolog crossovers (homolog bias). We propose that SOLO is a subunit of a specialized meiotic cohesin complex that mediates both centromeric and axial arm cohesion and promotes homolog bias as a component of chromosome cores. PMID:23874232

The cohesion protein SOLO associates with SMC1 and is required for synapsis, recombination, homolog bias and cohesion and pairing of centromeres in Drosophila Meiosis.

PubMed

Yan, Rihui; McKee, Bruce D

2013-01-01

Cohesion between sister chromatids is mediated by cohesin and is essential for proper meiotic segregation of both sister chromatids and homologs. solo encodes a Drosophila meiosis-specific cohesion protein with no apparent sequence homology to cohesins that is required in male meiosis for centromere cohesion, proper orientation of sister centromeres and centromere enrichment of the cohesin subunit SMC1. In this study, we show that solo is involved in multiple aspects of meiosis in female Drosophila. Null mutations in solo caused the following phenotypes: 1) high frequencies of homolog and sister chromatid nondisjunction (NDJ) and sharply reduced frequencies of homolog exchange; 2) reduced transmission of a ring-X chromosome, an indicator of elevated frequencies of sister chromatid exchange (SCE); 3) premature loss of centromere pairing and cohesion during prophase I, as indicated by elevated foci counts of the centromere protein CID; 4) instability of the lateral elements (LE)s and central regions of synaptonemal complexes (SCs), as indicated by fragmented and spotty staining of the chromosome core/LE component SMC1 and the transverse filament protein C(3)G, respectively, at all stages of pachytene. SOLO and SMC1 are both enriched on centromeres throughout prophase I, co-align along the lateral elements of SCs and reciprocally co-immunoprecipitate from ovarian protein extracts. Our studies demonstrate that SOLO is closely associated with meiotic cohesin and required both for enrichment of cohesin on centromeres and stable assembly of cohesin into chromosome cores. These events underlie and are required for stable cohesion of centromeres, synapsis of homologous chromosomes, and a recombination mechanism that suppresses SCE to preferentially generate homolog crossovers (homolog bias). We propose that SOLO is a subunit of a specialized meiotic cohesin complex that mediates both centromeric and axial arm cohesion and promotes homolog bias as a component of chromosome cores.

Activation of EGF receptor kinase by L1-mediated homophilic cell interactions.

PubMed

Islam, Rafique; Kristiansen, Lars V; Romani, Susana; Garcia-Alonso, Luis; Hortsch, Michael

2004-04-01

Neural cell adhesion molecules (CAMs) are important players during neurogenesis and neurite outgrowth as well as axonal fasciculation and pathfinding. Some of these developmental processes entail the activation of cellular signaling cascades. Pharmacological and genetic evidence indicates that the neurite outgrowth-promoting activity of L1-type CAMs is at least in part mediated by the stimulation of neuronal receptor tyrosine kinases (RTKs), especially FGF and EGF receptors. It has long been suspected that neural CAMs might physically interact with RTKs, but their activation by specific cell adhesion events has not been directly demonstrated. Here we report that gain-of-function conditions of the Drosophila L1-type CAM Neuroglian result in profound sensory axon pathfinding defects in the developing Drosophila wing. This phenotype can be suppressed by decreasing the normal gene dosage of the Drosophila EGF receptor gene. Furthermore, in Drosophila S2 cells, cell adhesion mediated by human L1-CAM results in the specific activation of human EGF tyrosine kinase at cell contact sites and EGF receptors engage in a physical interaction with L1-CAM molecules. Thus L1-type CAMs are able to promote the adhesion-dependent activation of EGF receptor signaling in vitro and in vivo.

Zebrafish Staufen1 and Staufen2 are required for the survival and migration of primordial germ cells.

PubMed

Ramasamy, Srinivas; Wang, Hui; Quach, Helen Ngoc Bao; Sampath, Karuna

2006-04-15

In sexually reproducing organisms, primordial germ cells (PGCs) give rise to the cells of the germ line, the gametes. In many animals, PGCs are set apart from somatic cells early during embryogenesis. Work in Drosophila, C. elegans, Xenopus, and zebrafish has shown that maternally provided localized cytoplasmic determinants specify the germ line in these organisms (Raz, E., 2003. Primordial germ-cell development: the zebrafish perspective. Nat. Rev., Genet. 4, 690--700; Santos, A.C., Lehmann, R., 2004. Germ cell specification and migration in Drosophila and beyond. Curr. Biol. 14, R578-R589). The Drosophila RNA-binding protein, Staufen is required for germ cell formation, and mutations in stau result in a maternal effect grandchild-less phenotype (Schupbach,T., Weischaus, E., 1989. Female sterile mutations on the second chromosome of Drosophila melanogaster:1. Maternal effect mutations. Genetics 121, 101-17). Here we describe the functions of two zebrafish Staufen-related proteins, Stau1 and Stau2. When Stau1 or Stau2 functions are compromised in embryos by injecting antisense morpholino modified oligonucleotides or dominant-negative Stau peptides, germ layer patterning is not affected. However, expression of the PGC marker vasa is not maintained. Furthermore, expression of a green fluorescent protein (GFP):nanos 3'UTR fusion protein in germ cells shows that PGC migration is aberrant, and the mis-migrating PGCs do not survive in Stau-compromised embryos. Stau2 is also required for survival of neurons in the central nervous system (CNS). These phenotypes are rescued by co-injection of Drosophila stau mRNA. Thus, staufen has an evolutionarily conserved function in germ cells. In addition, we have identified a function for Stau proteins in PGC migration.

Identifying Tumor Progenitor Cells | Center for Cancer Research

Cancer.gov

All cells within a tumor are not identical. In fact, only a small subset appears to be capable of actually generating the tumor. These tumor-initiating cells tend to resemble normal stem cells, which have the unique ability to give rise to differentiated cells while simultaneously producing additional undifferentiated stem cells. Most chemotherapeutics affect the bulk of a

UTF1, a Putative Marker for Spermatogonial Stem Cells in Stallions

PubMed Central

Jung, Heejun; Roser, Janet F.; Yoon, Minjung

2014-01-01

Spermatogonial stem cells (SSCs) continuously undergo self-renewal and differentiation to sustain spermatogenesis throughout adulthood in males. In stallions, SSCs may be used for the production of progeny from geldings after cryopreservation and therapy for infertile and subfertile stallions. Undifferentiated cell transcription factor 1 (UTF1) is a putative marker for undifferentiated spermatogonia in humans and rats. The main purposes of this study are to determine the following: 1) changes in the expression pattern of UTF1 at various reproductive stages of stallions, 2) subpopulations of spermatogonia that express UTF1. Testicular samples were collected and categorized based on the age of the horses as follows: pre-pubertal (<1 yr), pubertal (1–1.5 yr), post-pubertal (2–3 yr), and adult (4–8 yr). Western blot analysis was utilized to determine the cross-activity of the UTF1 antibody to horse testes tissues. Immunohistochemistry was conducted to investigate the UTF1 expression pattern in germ cells at different reproductive stages. Whole mount staining was applied to determine the subpopulation of UTF1-positive spermatogonia. Immunohistological analysis showed that most germ cells in the pre-pubertal and pubertal stages were immunolabeled with UTF1, whereas only a few germ cells in the basal compartment of the seminiferous tubule cross-sections of post-pubertal and adult tissues were UTF1-positive. No staining was observed in the Sertoli or Leydig cells at any reproductive stages. Whole mount staining showed that As, Apr, and chains of 4, 8, 16 Aal spermatogonia were immunolabeled with UTF1 in the post-pubertal stallion tubule. Isolated single germ cells were also immunolabeled with UTF1. In conclusion, UTF1 is expressed in undifferentiated spermatogonia, and its antibody can be used as a putative marker for SSCs in stallions. PMID:25272017

Drug repurposing for aging research using model organisms.

PubMed

Ziehm, Matthias; Kaur, Satwant; Ivanov, Dobril K; Ballester, Pedro J; Marcus, David; Partridge, Linda; Thornton, Janet M

2017-10-01

Many increasingly prevalent diseases share a common risk factor: age. However, little is known about pharmaceutical interventions against aging, despite many genes and pathways shown to be important in the aging process and numerous studies demonstrating that genetic interventions can lead to a healthier aging phenotype. An important challenge is to assess the potential to repurpose existing drugs for initial testing on model organisms, where such experiments are possible. To this end, we present a new approach to rank drug-like compounds with known mammalian targets according to their likelihood to modulate aging in the invertebrates Caenorhabditis elegans and Drosophila. Our approach combines information on genetic effects on aging, orthology relationships and sequence conservation, 3D protein structures, drug binding and bioavailability. Overall, we rank 743 different drug-like compounds for their likelihood to modulate aging. We provide various lines of evidence for the successful enrichment of our ranking for compounds modulating aging, despite sparse public data suitable for validation. The top ranked compounds are thus prime candidates for in vivo testing of their effects on lifespan in C. elegans or Drosophila. As such, these compounds are promising as research tools and ultimately a step towards identifying drugs for a healthier human aging. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Tip off the HAT– Epigenetic control of learning and memory by Drosophila Tip60

PubMed Central

Xu, Songjun; Elefant, Felice

2015-01-01

Disruption of epigenetic gene control mechanisms involving histone acetylation in the brain causes cognitive impairment, a debilitating hallmark of most neurodegenerative disorders. Histone acetylation regulates cognitive gene expression via chromatin packaging control in neurons. Unfortunately, the histone acetyltransferases (HATs) that generate such neural epigenetic signatures and their mechanisms of action remain unclear. Our recent findings provide insight into this question by demonstrating that Tip60 HAT action is critical for morphology and function of the mushroom body (MB), the learning and memory center in the Drosophila brain. We show that Tip60 is robustly produced in MB Kenyon cells and extending axonal lobes and that targeted MB Tip60 HAT loss results in axonal outgrowth disruption. Functional consequences of loss and gain of Tip60 HAT levels in the MB are evidenced by defects in memory. Tip60 ChIP-Seq analysis reveals enrichment for genes that function in cognitive processes and accordingly, key genes representing these pathways are misregulated in the Tip60 HAT mutant fly brain. Remarkably, increasing levels of Tip60 in the MB rescues learning and memory deficits resulting from Alzheimer's disease associated amyloid precursor protein (APP) induced neurodegeneration. Our studies highlight the potential of HAT activators as a therapeutic option for cognitive disorders. PMID:26327426

Label-free imaging of Drosophila in vivo by coherent anti-Stokes Raman scattering and two-photon excitation autofluorescence microscopy

NASA Astrophysics Data System (ADS)

Chien, Cheng-Hao; Chen, Wei-Wen; Wu, June-Tai; Chang, Ta-Chau

2011-01-01

Drosophila is one of the most valuable model organisms for studying genetics and developmental biology. The fat body in Drosophila, which is analogous to the liver and adipose tissue in human, stores lipids that act as an energy source during its development. At the early stages of metamorphosis, the fat body remodeling occurs involving the dissociation of the fat body into individual fat cells. Here we introduce a combination of coherent anti-Stokes Raman scattering (CARS) and two-photon excitation autofluorescence (TPE-F) microscopy to achieve label-free imaging of Drosophila in vivo at larval and pupal stages. The strong CARS signal from lipids allows direct imaging of the larval fat body and pupal fat cells. In addition, the use of TPE-F microscopy allows the observation of other internal organs in the larva and autofluorescent globules in fat cells. During the dissociation of the fat body, the findings of the degradation of lipid droplets and an increase in autofluorescent globules indicate the consumption of lipids and the recruitment of proteins in fat cells. Through in vivo imaging and direct monitoring, CARS microscopy may help elucidate how metamorphosis is regulated and study the lipid metabolism in Drosophila.

TOR-mediated autophagy regulates cell death in Drosophila neurodegenerative disease.

PubMed

Wang, Tao; Lao, Uyen; Edgar, Bruce A

2009-09-07

Target of rapamycin (TOR) signaling is a regulator of cell growth. TOR activity can also enhance cell death, and the TOR inhibitor rapamycin protects cells against proapoptotic stimuli. Autophagy, which can protect against cell death, is negatively regulated by TOR, and disruption of autophagy by mutation of Atg5 or Atg7 can lead to neurodegeneration. However, the implied functional connection between TOR signaling, autophagy, and cell death or degeneration has not been rigorously tested. Using the Drosophila melanogaster visual system, we show in this study that hyperactivation of TOR leads to photoreceptor cell death in an age- and light-dependent manner and that this is because of TOR's ability to suppress autophagy. We also find that genetically inhibiting TOR or inducing autophagy suppresses cell death in Drosophila models of Huntington's disease and phospholipase C (norpA)-mediated retinal degeneration. Thus, our data indicate that TOR induces cell death by suppressing autophagy and provide direct genetic evidence that autophagy alleviates cell death in several common types of neurodegenerative disease.

Day-night cycles and the sleep-promoting factor, Sleepless, affect stem cell activity in the Drosophila testis.

PubMed

Tulina, Natalia M; Chen, Wen-Feng; Chen, Jung Hsuan; Sowcik, Mallory; Sehgal, Amita

2014-02-25

Adult stem cells maintain tissue integrity and function by renewing cellular content of the organism through regulated mitotic divisions. Previous studies showed that stem cell activity is affected by local, systemic, and environmental cues. Here, we explore a role of environmental day-night cycles in modulating cell cycle progression in populations of adult stem cells. Using a classic stem cell system, the Drosophila spermatogonial stem cell niche, we reveal daily rhythms in division frequencies of germ-line and somatic stem cells that act cooperatively to produce male gametes. We also examine whether behavioral sleep-wake cycles, which are driven by the environmental day-night cycles, regulate stem cell function. We find that flies lacking the sleep-promoting factor Sleepless, which maintains normal sleep in Drosophila, have increased germ-line stem cell (GSC) division rates, and this effect is mediated, in part, through a GABAergic signaling pathway. We suggest that alterations in sleep can influence the daily dynamics of GSC divisions.

Drosophila blood cells and their role in immune responses.

PubMed

Vlisidou, Isabella; Wood, Will

2015-04-01

Drosophila melanogaster has been extensively used to study the humoral arm of innate immunity because of the developmental and functional parallels with mammalian innate immunity. However, the fly cellular response to infection is far less understood. Investigative work on Drosophila haemocytes, the immunosurveillance cells of the insect, has revealed that they fulfil roles similar to mammalian monocytes and macrophages. They respond to wound signals and orchestrate the coagulation response. In addition, they phagocytose and encapsulate invading pathogens, and clear up apoptotic bodies controlling inflammation. This review briefly describes the Drosophila haematopoietic system and discusses what is currently known about the contribution of haemocytes to the immune response upon infection and wounding, during all stages of development. © 2015 FEBS.

Gene expression profiling of rat spermatogonia and Sertoli cells reveals signaling pathways from stem cells to niche and testicular cancer cells to surrounding stroma

PubMed Central

2011-01-01

Background Stem cells and their niches are studied in many systems, but mammalian germ stem cells (GSC) and their niches are still poorly understood. In rat testis, spermatogonia and undifferentiated Sertoli cells proliferate before puberty, but at puberty most spermatogonia enter spermatogenesis, and Sertoli cells differentiate to support this program. Thus, pre-pubertal spermatogonia might possess GSC potential and pre-pubertal Sertoli cells niche functions. We hypothesized that the different stem cell pools at pre-puberty and maturity provide a model for the identification of stem cell and niche-specific genes. We compared the transcript profiles of spermatogonia and Sertoli cells from pre-pubertal and pubertal rats and examined how these related to genes expressed in testicular cancers, which might originate from inappropriate communication between GSCs and Sertoli cells. Results The pre-pubertal spermatogonia-specific gene set comprised known stem cell and spermatogonial stem cell (SSC) markers. Similarly, the pre-pubertal Sertoli cell-specific gene set comprised known niche gene transcripts. A large fraction of these specifically enriched transcripts encoded trans-membrane, extra-cellular, and secreted proteins highlighting stem cell to niche communication. Comparing selective gene sets established in this study with published gene expression data of testicular cancers and their stroma, we identified sets expressed genes shared between testicular tumors and pre-pubertal spermatogonia, and tumor stroma and pre-pubertal Sertoli cells with statistic significance. Conclusions Our data suggest that SSC and their niche specifically express complementary factors for cell communication and that the same factors might be implicated in the communication between tumor cells and their micro-enviroment in testicular cancer. PMID:21232125

Morphological differentiation of N1E-115 neuroblastoma cells by dimethyl sulfoxide activation of lipid second messengers.

PubMed

Clejan, S; Dotson, R S; Wolf, E W; Corb, M P; Ide, C F

1996-04-10

Quantitative changes in the lipid second messenger diacylglycerol (DAG) were studied in the rat neuroblastoma N1E-115 following exposure to the differentiating agent dimethylsulfoxide (DMSO). Relatively high basal levels of DAG are present in these cells, and addition of 2% DMSO elicited a biphasic increase in DAG levels, dependent on the presence of extracellular Ca2+. Exposure to DMSO also elicited a rapid increase in inositol phosphate and a slight increase in phosphatidic acid (PA), trailing that of DAG. The molecular species (MS) of DAG were analyzed. Within 60 s of DMSO application there were transient increases of DAG representative of phosphatidylinositol (PI) hydrolysis. At longer intervals, more DAG originated from phosphatidylcholine. The MS composition of newly formed PA resembled that of PI and native DAG. Inhibition studies indicated that DAG is formed in the DMSO-treated cells by phospholipases C and that PA formed later is a result of DAG phosphorylation and not activity of phospholipase D (PLD). Undifferentiated cells exhibited an active PLD pathway. In contrast, PLD in DMSO-differentiated cells was not active. In examining the involvement of the sphingomyelin pathway, DMSO exposure was found to increase ceramide levels with a concomitant decrease in sphingomyelin. Addition of the exogenous, soluble analog C6-ceramide to undifferentiated cells resulted in dramatic reductions in DAG and PA levels and PLD activity. These results indicate that DMSO treatment inactivates PLD while activating phospholipases C and the sphingomyelin pathway, suggesting a "switch" between signal transduction pathways in the undifferentiated and differentiated states of N1E-115.

Mechanisms of Regulating Tissue Elongation in Drosophila Wing: Impact of Oriented Cell Divisions, Oriented Mechanical Forces, and Reduced Cell Size

PubMed Central

Li, Yingzi; Naveed, Hammad; Kachalo, Sema; Xu, Lisa X.; Liang, Jie

2014-01-01

Regulation of cell growth and cell division plays fundamental roles in tissue morphogenesis. However, the mechanisms of regulating tissue elongation through cell growth and cell division are still not well understood. The wing imaginal disc of Drosophila provides a model system that has been widely used to study tissue morphogenesis. Here we use a recently developed two-dimensional cellular model to study the mechanisms of regulating tissue elongation in Drosophila wing. We simulate the effects of directional cues on tissue elongation. We also computationally analyze the role of reduced cell size. Our simulation results indicate that oriented cell divisions, oriented mechanical forces, and reduced cell size can all mediate tissue elongation, but they function differently. We show that oriented cell divisions and oriented mechanical forces act as directional cues during tissue elongation. Between these two directional cues, oriented mechanical forces have a stronger influence than oriented cell divisions. In addition, we raise the novel hypothesis that reduced cell size may significantly promote tissue elongation. We find that reduced cell size alone cannot drive tissue elongation. However, when combined with directional cues, such as oriented cell divisions or oriented mechanical forces, reduced cell size can significantly enhance tissue elongation in Drosophila wing. Furthermore, our simulation results suggest that reduced cell size has a short-term effect on cell topology by decreasing the frequency of hexagonal cells, which is consistent with experimental observations. Our simulation results suggest that cell divisions without cell growth play essential roles in tissue elongation. PMID:24504016

Oxygen Tension Modulates Differentiation and Primary Macrophage Functions in the Human Monocytic THP-1 Cell Line

PubMed Central

Grodzki, Ana Cristina G.; Giulivi, Cecilia; Lein, Pamela J.

2013-01-01

The human THP-1 cell line is widely used as an in vitro model system for studying macrophage differentiation and function. Conventional culture conditions for these cells consist of ambient oxygen pressure (∼20% v/v) and medium supplemented with the thiol 2-mercaptoethanol (2-ME) and serum. In consideration of the redox activities of O2 and 2-ME, and the extensive experimental evidence supporting a role for reactive oxygen species (ROS) in the differentiation and function of macrophages, we addressed the question of whether culturing THP-1 cells under a more physiologically relevant oxygen tension (5% O2) in the absence of 2-ME and serum would alter THP-1 cell physiology. Comparisons of cultures maintained in 18% O2 versus 5% O2 indicated that reducing oxygen tension had no effect on the proliferation of undifferentiated THP-1 cells. However, decreasing the oxygen tension to 5% O2 significantly increased the rate of phorbol ester-induced differentiation of THP-1 cells into macrophage-like cells as well as the metabolic activity of both undifferentiated and PMA-differentiated THP-1 cells. Removal of both 2-ME and serum from the medium decreased the proliferation of undifferentiated THP-1 cells but increased metabolic activity and the rate of differentiation under either oxygen tension. In differentiated THP-1 cells, lowering the oxygen tension to 5% O2 decreased phagocytic activity, the constitutive release of β-hexosaminidase and LPS-induced NF-κB activation but enhanced LPS-stimulated release of cytokines. Collectively, these data demonstrate that oxygen tension influences THP-1 cell differentiation and primary macrophage functions, and suggest that culturing these cells under tightly regulated oxygen tension in the absence of exogenous reducing agent and serum is likely to provide a physiologically relevant baseline from which to study the role of the local redox environment in regulating THP-1 cell physiology. PMID:23355903

Using Fluorescent Reporters to Monitor Autophagy in the Female Germline Cells in Drosophila melanogaster.

PubMed

Jacomin, Anne-Claire; Nezis, Ioannis P

2016-01-01

Oogenesis is a fundamental biological process for the transmission of genetic information to the next generations. Drosophila has proven to be a valuable model for elucidating the molecular and cellular mechanisms involved in this developmental process. It has been shown that autophagy participates in the maturation of the egg chamber. Here we provide a protocol for monitoring and quantification of the autophagic process in the Drosophila germline cells using the fluorescent reporters mCherry-DmAtg8a and GFP-mCherry-DmAtg8a.

Pathological modifications of plant stem cell destiny

USDA-ARS?s Scientific Manuscript database

In higher plants, the shoot apex contains undifferentiated stem cells that give rise to various tissues and organs. The fate of these stem cells determines the pattern of plant growth as well as reproduction; and such fate is genetically preprogrammed. We found that a bacterial infection can derai...

Ethanol does not inhibit the adhesive activity of Drosophila neuroglian or human L1 in Drosophila S2 tissue culture cells.

PubMed

Vallejo, Y; Hortsch, M; Dubreuil, R R

1997-05-02

Members of the L1 family of homophilic neural cell adhesion molecules are thought to play an important role in nervous system development and function. It is also suggested that L1 is a direct target of ethanol in fetal alcohol syndrome, since ethanol inhibits the aggregation of cultured cells expressing L1 (Ramanathan, R., Wilkemeyer, M. F., Mittel, B., Perides, G., and Charness, M. E. (1996) J. Cell Biol. 133, 381-390). If ethanol acts directly on the homophilic adhesive function of the L1 molecule, then inhibition of aggregation by ethanol should be observed in any cell type that expresses L1. Here we examined the effect of physiologically relevant concentrations of ethanol on the aggregation of Drosophila S2 cells that expressed either neuroglian (the Drosophila homolog of L1) or human L1. The aggregation of these S2 cells is known to be solely dependent on the homophilic interactions between L1 or neuroglian molecules. Neither cell adhesion molecule was affected when cell aggregation assays were carried out in the presence of >/=38 mM ethanol. The recruitment of membrane skeleton assembly at sites of cell-cell contact (a transmembrane signaling function of human L1) was also unaffected by the presence of ethanol. Thus the previously described inhibition of cell adhesion by ethanol in L1-expressing cells cannot be explained by a simple direct effect on the adhesive activity of L1 family members.

Using the mouse embryonic stem cell test (EST) to evaluate the embryotoxicity of haloacetic acids

EPA Science Inventory

The Embryonic Stem Cell Test (EST) is used to predict the embryotoxic potential of a test compound by combining the data from cytotoxicity assays in undifferentiated mouse embryonic stem (mES) cells and differentiated mouse cells with the data from a differentiation assay in mES ...

Programmed cell death acts at different stages of Drosophila neurodevelopment to shape the central nervous system

PubMed Central

Desplan, Claude

2016-01-01

Nervous system development is a process that integrates cell proliferation, differentiation and programmed cell death (PCD). PCD is an evolutionary conserved mechanism and a fundamental developmental process by which the final cell number in a nervous system is established. In vertebrates and invertebrates, PCD can be determined intrinsically by cell lineage and age, as well as extrinsically by nutritional, metabolic and hormonal states. Drosophila has been an instrumental model for understanding how this mechanism is regulated. We review the role of PCD in Drosophila central nervous system development from neural progenitors to neurons, its molecular mechanism and function, how it is regulated and implemented, and how it ultimately shapes the fly central nervous system from the embryo to the adult. Finally, we discuss ideas that emerge while integrating this information. PMID:27404003

Receptor clustering drives polarized assembly of ankyrin.

PubMed

Jefford, G; Dubreuil, R R

2000-09-08

Expression of the L1 family cell adhesion molecule neuroglian in Drosophila S2 cells leads to cell aggregation and polarized ankyrin accumulation at sites of cell-cell contact. Thus neuroglian adhesion generates a spatial cue for polarized assembly of ankyrin and the spectrin cytoskeleton. Here we characterized a chimera of the extracellular and transmembrane domains of rat CD2 fused to the cytoplasmic domain of neuroglian. The chimera was used to test the hypothesis that clustering of neuroglian at sites of adhesion generates the signal that activates ankyrin binding. Abundant expression of the chimera at the plasma membrane was not a sufficient cue to drive ankyrin assembly, since ankyrin remained diffusely distributed throughout the cytoplasm of CD2-neuroglian-expressing cells. However, ankyrin became highly enriched at sites of antibody-induced capping of CD2-neuroglian. Spectrin codistributed with ankyrin at capped sites. A green fluorescent protein-tagged ankyrin was used to monitor ankyrin distribution in living cells. Enhanced green fluorescent protein-ankyrin behaved identically to antibody-stained endogenous ankyrin, proving that the polarized accumulation of ankyrin was not an artifact of fixing and staining cells. We propose a model in which clustering of neuroglian induces a conformational change in the cytoplasmic domain that drives polarized assembly of the spectrin cytoskeleton.

Bone marrow-derived mesenchymal stem cells assembled with low-dose BMP-2 in a three-dimensional hybrid construct enhances posterolateral spinal fusion in syngeneic rats.

PubMed

Hu, Tao; Abbah, Sunny Akogwu; Toh, Soo Yein; Wang, Ming; Lam, Raymond Wing Moon; Naidu, Mathanapriya; Bhakta, Gajadhar; Cool, Simon M; Bhakoo, Kishore; Li, Jun; Goh, James Cho-Hong; Wong, Hee-Kit

2015-12-01

The combination of potent osteoinductive growth factor, functional osteoblastic cells, and osteoconductive materials to induce bone formation is a well-established concept in bone tissue engineering. However, supraphysiological dose of growth factor, such as recombinant human bone morphogenetic protein 2 (rhBMP-2), which is necessary in contemporary clinical application, have been reported to result in severe side effects. We hypothesize that the synergistic osteoinductive capacity of low-dose bone morphogenetic protein 2 (BMP-2) combined with undifferentiated bone marrow-derived stromal cells (BMSCs) is comparable to that of osteogenically differentiated BMSCs when used in a rodent model of posterolateral spinal fusion. A prospective study using a rodent model of posterolateral spinal fusion was carried out. Thirty-six syngeneic Fischer rats comprised the patient sample. Six groups of implants were evaluated as follows (n=6): (1) 10 µg BMP-2 with undifferentiated BMSCs; (2) 10 µg BMP-2 with osteogenic-differentiated BMSCs; (3) 2.5 µg BMP-2 with undifferentiated BMSCs; (4) 2.5 µg BMP-2 with osteogenic-differentiated BMSCs; (5) 0.5 µg BMP-2 with undifferentiated BMSCs; and (6) 0.5 µg BMP-2 with osteogenic-differentiated BMSCs. Optimal in vitro osteogenic differentiation of BMSCs was determined by quantitative real-time polymerase chain reaction (qRT-PCR) gene analysis whereas in vivo bone formation capacity was evaluated by manual palpation, micro-computed tomography, and histology. Rat BMSCs cultured in fibrin matrix that was loaded into the pores of medical-grade poly epsilon caprolactone tricalcium phosphate scaffolds differentiated toward osteogenic lineage by expressing osterix, runt-related transcription factor 2, and osteocalcium mRNA when supplemented with dexamethasone, ascorbic acid, and β-glycerophosphate. Whereas qRT-PCR revealed optimal increase in osteogenic genes expression after 7 days of in vitro culture, in vivo transplantation study showed that pre-differentiation of BMSCs before transplantation failed to promote posterolateral spinal fusion when co-delivered with low-dose BMP-2 (1/6 or 17% fusion rate). In contrast, combined delivery of undifferentiated BMSCs with low-dose BMP-2 (2.5 µg) demonstrated significantly higher fusion rate (4/6 or 67%) as well as significantly increased volume of new bone formation (p<.05). In summary, this study supports the combination of undifferentiated BMSCs and low-dose rhBMP-2 for bone tissue engineering construct. Copyright © 2015 Elsevier Inc. All rights reserved.

Changes in proto-oncogene expression associated with reversal of macrophage-like differentiation of HL 60 cells.

PubMed

Studzinski, G P; Brelvi, Z S

1987-07-01

Prolonged exposure to 1 alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3] of 2 sublines (AB-2 and AB-26) of human promyelocytic HL 60 leukemia cells produced increased adherence of the cells to the culture substratum. Advantage was taken of this property to separate physically a population of cells highly enriched in macrophage-like forms. When these differentiated cells were placed in culture medium free of 1,25(OH)2D3, there was a rapid reversal of the features of the differentiated phenotype, monitored by the loss of alpha-naphthyl butyrate esterase activity and the loss of adherence to the substrate. The reversal was accompanied by the resumption of normal rates of DNA synthesis, mitosis, and reaccumulation of c-myc and c-myb transcripts. The levels of transcripts of oncogenes c-fos and c-fms, which became abundant in the phenotypically differentiated cultures, declined along with the loss of adhesiveness and reversion to more primitive myeloblastic forms. These changes in proto-oncogene expression became evident before cell proliferation resumed, thereby excluding the diluting effect of the outgrowth of undifferentiated cells. It is concluded that in this system there is no firm commitment to terminal, as opposed to early, differentiation in the great majority of the cells and that the expression of the monocytic maturation-associated genes c-fos and c-fms is down-regulated when macrophage-like cells dedifferentiate. This strengthens the case for an association between macrophage differentiation and the expression of oncogenes c-fos and c-fms.

The adult Drosophila malphigian tubules are maintained by multipotent stem cells | Center for Cancer Research

Cancer.gov

All animals must excrete the waste products of metabolism. Excretion is performed by the kidney in vertebrates and by the Malpighian tubules in Drosophila. The mammalian kidney has an inherent ability for recovery and regeneration after ischemic injury. Stem cells and progenitor cells have been proposed to be responsible for repair and regeneration of injured renal tissue.

Evidence of acrylamide induced oxidative stress and neurotoxicity in Drosophila melanogaster - its amelioration with spice active enrichment: relevance to neuropathy.

PubMed

Prasad, Sathya N; Muralidhara

2012-10-01

Acrylamide (ACR) intoxication in its monomeric form leads to neuronal damage in both experimental animals and humans. Oxidative stress is one of the principle mechanisms related to the neurotoxicity of ACR exposure. Hence, the present study aimed to recapitulate the potential of ACR to cause oxidative stress and neurotoxic effects in Drosophila melanogaster. Exposure of adult male flies (Oregon K strain) to ACR (1-10 mM, 7 d) in the diet resulted in a concentration and time dependent mortality, while the survivors exhibited significant locomotor deficits. Further, ACR exposure (1-5 mM, 3 d) caused robust oxidative stress as evidenced by markedly elevated levels of reactive oxygen species and hypdroperoxides in head/body regions. Enhanced lipid peroxidation, perturbations in the activities of antioxidant enzymes accompanied with depletion of reduced glutathione levels in head region at high concentrations suggested induction of oxidative stress. Further, marked diminution in the activities of complexes I-III, Succinic dehydrogenase, with concomitant reduction in MTT suggested the propensity of ACR to impair mitochondrial function. Furthermore, ACR-induced neurotoxic effects were discernible in terms of diminished ATPase activity, enhanced activity of acetylcholinesterase and dopamine depletion. In a satellite study, employing a co-exposure paradigm, we tested the propensity of spice actives namely eugenol (EU) and isoeugenol (IE) to ameliorate ACR-induced neurotoxicity. EU/IE enriched diet offered marked protection against ACR-induced mortality, locomotor dysfunctions and oxidative stress. Furthermore, the spice actives prevented the depletion of reduced GSH levels, maintained the activity of AChE enzyme and dopamine levels in head region. Collectively, these findings clearly demonstrate that ACR induced neurotoxicity in Drosophila may be mediated through oxidative stress mechanisms and the potential of spice actives to abrogate the condition. These data suggest that Drosophila may serve as a suitable model to understand the possible mechanism/s associated with ACR associated neuropathy. Copyright © 2012 Elsevier Inc. All rights reserved.

vasa is expressed in somatic cells of the embryonic gonad in a sex-specific manner in Drosophila melanogaster

PubMed Central

Renault, Andrew D.

2012-01-01

Summary Vasa is a DEAD box helicase expressed in the Drosophila germline at all stages of development. vasa homologs are found widely in animals and vasa has become the gene of choice in identifying germ cells. I now show that Drosophila vasa expression is not restricted to the germline but is also expressed in a somatic lineage, the embryonic somatic gonadal precursor cells. This expression is sexually dimorphic, being maintained specifically in males, and is regulated post-transcriptionally. Although somatic Vasa expression is not required for gonad coalescence, these data support the notion that Vasa is not solely a germline factor. PMID:23213382

Spermatogonial Stem Cell Niche and Spermatogonial Stem Cell Transplantation in Zebrafish

PubMed Central

Nóbrega, Rafael Henrique; Greebe, Caaj Douwe; van de Kant, Henk; Bogerd, Jan; de França, Luiz Renato; Schulz, Rüdiger W.

2010-01-01

Background Spermatogonial stem cells (SSCs) are the foundation of spermatogenesis, and reside within a specific microenvironment in the testes called “niche” which regulates stem cell properties, such as, self-renewal, pluripotency, quiescence and their ability to differentiate. Methodology/Principal Findings Here, we introduce zebrafish as a new model for the study of SSCs in vertebrates. Using 5′-bromo-2′-deoxyuridine (BrdU), we identified long term BrdU-retaining germ cells, type A undifferentiated spermatogonia as putative stem cells in zebrafish testes. Similar to rodents, these cells were preferentially located near the interstitium, suggesting that the SSC niche is related to interstitial elements and might be conserved across vertebrates. This localization was also confirmed by analyzing the topographical distribution of type A undifferentiated spermatogonia in normal, vasa::egfp and fli::egfp zebrafish testes. In the latter one, the topographical arrangement suggested that the vasculature is important for the SSC niche, perhaps as a supplier of nutrients, oxygen and/or signaling molecules. We also developed an SSC transplantation technique for both male and female recipients as an assay to evaluate the presence, biological activity, and plasticity of the SSC candidates in zebrafish. Conclusions/Significance We demonstrated donor-derived spermato- and oogenesis in male and female recipients, respectively, indicating the stemness of type A undifferentiated spermatogonia and their plasticity when placed into an environment different from their original niche. Similar to other vertebrates, the transplantation efficiency was low. This might be attributed to the testicular microenvironment created after busulfan depletion in the recipients, which may have caused an imbalance between factors regulating self-renewal or differentiation of the transplanted SSCs. PMID:20862221

A strategy for isolation of cDNAs encoding proteins affecting human intestinal epithelial cell growth and differentiation: characterization of a novel gut-specific N-myristoylated annexin.

PubMed

Wice, B M; Gordon, J I

1992-01-01

The human intestinal epithelium is rapidly and perpetually renewed as the descendants of multipotent stem cells located in crypts undergo proliferation, differentiation, and eventual exfoliation during a very well organized migration along the crypt to villus axis. The mechanisms that establish and maintain this balance between proliferation and differentiation are largely unknown. We have utilized HT-29 cells, derived from a human colon adenocarcinoma, as a model system for identifying gene products that may regulate these processes. Proliferating HT-29 cells cultured in the absence of glucose (e.g., using inosine as the carbon source) have some of the characteristics of undifferentiated but committed crypt epithelial cells while postconfluent cells cultured in the absence of glucose resemble terminally differentiated enterocytes or goblet cells. A cDNA library, constructed from exponentially growing HT-29 cells maintained in inosine-containing media, was sequentially screened with a series of probes depleted of sequences encoding housekeeping functions and enriched for intestine-specific sequences that are expressed in proliferating committed, but not differentiated, epithelial cells. Of 100,000 recombinant phage surveyed, one was found whose cDNA was derived from an apparently gut-specific mRNA. It encodes a 316 residue, 35,463-D protein that is a new member of the annexin/lipocortin family. Other family members have been implicated in regulation of cellular growth and in signal transduction pathways. RNA blot and in situ hybridization studies indicate that the gene encoding this new annexin exhibits region-specific expression along both axes of the human gut: (a) highest levels of mRNA are present in the jejunum with marked and progressive reductions occurring distally; (b) its mRNA appears in crypt-associated epithelial cells and increases in concentration as they exit the crypt. Villus-associated epithelial cells continue to transcribe this gene during their differentiation/translocation up the villus. Immunocytochemical studies reveal that the intestine-specific annexin (ISA) is associated with the plasma membrane of undifferentiated, proliferating crypt epithelial cells as well as differentiated villus enterocytes. In polarized enterocytes, the highest concentrations of ISA are found at the apical compared to basolateral membrane. In vitro studies using an octapeptide derived from residues 2-9 of the primary translation product of ISA mRNA and purified myristoyl-CoA:protein N-myristoyltransferase suggested that it is N-myristoylated. In vivo labeling studies confirmed that myristate is covalently attached to ISA via a hydroxylamine resistant amide linkage. The restricted cellular expression and acylation of ISA distinguish it from other known annexins.(ABSTRACT TRUNCATED AT 400 WORDS)

Drosophila: a model for studying genetic and molecular aspects of haematopoiesis and associated leukaemias

PubMed Central

Crozatier, Michèle; Vincent, Alain

2011-01-01

Vertebrate haematopoietic stem cells (HSCs) give rise to a hierarchically organised set of progenitors for erythroid, myeloid, lymphoid and megakaryocyte lineages, and are responsible for lifelong maintenance of the blood system. Dysregulation of the haematopoietic differentiation programme is at the origin of numerous pathologies, including leukaemias. With the discoveries that many transcriptional regulators and signalling pathways controlling blood cell development are conserved between humans and Drosophila melanogaster, the fruit fly has become a good model for investigating the mechanisms underlying the generation of blood cell lineages and blood cell homeostasis. In this review article, we discuss how genetic and molecular studies of Drosophila haematopoiesis can contribute to our understanding of the haematopoietic niche, as well as of the origin and/or progression of haematopoietic malignancies in humans. PMID:21669932

Loss of l(3)mbt leads to acquisition of the ping-pong cycle in Drosophila ovarian somatic cells

PubMed Central

Sumiyoshi, Tetsutaro; Sato, Kaoru; Yamamoto, Hitomi; Iwasaki, Yuka W.; Siomi, Haruhiko; Siomi, Mikiko C.

2016-01-01

In Drosophila germ cells, PIWI-interacting RNAs (piRNAs) are amplified through a PIWI slicer-dependent feed-forward loop termed the ping-pong cycle, yielding secondary piRNAs. However, the detailed mechanism remains poorly understood, largely because an ex vivo model system amenable to biochemical analyses has not been available. Here, we show that CRISPR-mediated loss of function of lethal (3) malignant brain tumor [l(3)mbt] leads to ectopic activation of the germ-specific ping-pong cycle in ovarian somatic cells. Perinuclear foci resembling nuage, the ping-pong center, appeared following l(3)mbt mutation. This activation of the ping-pong machinery in cultured cells will greatly facilitate elucidation of the mechanism underlying secondary piRNA biogenesis in Drosophila. PMID:27474440

The L1-type cell adhesion molecule neuroglian influences the stability of neural ankyrin in the Drosophila embryo but not its axonal localization.

PubMed

Bouley, M; Tian, M Z; Paisley, K; Shen, Y C; Malhotra, J D; Hortsch, M

2000-06-15

Ankyrins are linker proteins, which connect various membrane proteins, including members of the L1 family of neural cell adhesion molecules, with the submembranous actin-spectrin skeleton. Here we report the cloning and characterization of a second, novel Drosophila ankyrin gene (Dank2) that appears to be the result of a gene duplication event during arthropod evolution. The Drosophila L1-type protein neuroglian interacts with products from both Drosophila ankyrin genes. Whereas the previously described ankyrin gene is ubiquitously expressed during embryogenesis, the expression of Dank2 is restricted to the nervous system in the Drosophila embryo. The absence of neuroglian protein in a neuroglian null mutant line causes decreased levels of Dank2 protein in most neuronal cells. This suggests that neuroglian is important for the stability of Dank2 protein. However, neuroglian is not required for Dank2 axonal localization. In temperature-sensitive neuroglian mutants in which neuroglian protein is mislocated at the restrictive temperature to an intracellular location in the neuronal soma, Dank2 protein can still be detected along embryonic nerve tracts.

Drosophila contactin, a homolog of vertebrate contactin, is required for septate junction organization and paracellular barrier function.

PubMed

Faivre-Sarrailh, Catherine; Banerjee, Swati; Li, Jingjun; Hortsch, Michael; Laval, Monique; Bhat, Manzoor A

2004-10-01

Septate junctions (SJs) in epithelial and neuronal cells play an important role in the formation and maintenance of charge and size selective barriers. They form the basis for the ensheathment of nerve fibers in Drosophila and for the attachment of myelin loops to axonal surface in vertebrates. The cell-adhesion molecules NRX IV/Caspr/Paranodin (NCP1), contactin and Neurofascin-155 (NF-155) are all present at the vertebrate axo-glial SJs. Mutational analyses have shown that vertebrate NCP1 and its Drosophila homolog, Neurexin IV (NRX IV) are required for the formation of SJs. In this study, we report the genetic, molecular and biochemical characterization of the Drosophila homolog of vertebrate contactin, CONT. Ultrastructural and dye-exclusion analyses of Cont mutant embryos show that CONT is required for organization of SJs and paracellular barrier function. We show that CONT, Neuroglian (NRG) (Drosophila homolog of NF-155) and NRX IV are interdependent for their SJ localization and these proteins form a tripartite complex. Hence, our data provide evidence that the organization of SJs is dependent on the interactions between these highly conserved cell-adhesion molecules.

Odor-Evoked Inhibition of Olfactory Sensory Neurons Drives Olfactory Perception in Drosophila

DTIC Science & Technology

2017-05-22

J.L. Highly efficient targeted 859 mutagenesis of Drosophila with the CRISPR /Cas9 system. Cell Rep. 4, 220-228 860 (2013). 861 53. Gratz, S.J...Harrison, M.M., Wildonger, J. & O’Connor-Giles, K.M. Precise 862 Genome Editing of Drosophila with CRISPR RNA-Guided Cas9. Methods Mol. 863 Biol. 1311

Juvenile Hormone Regulation of Drosophila Epac - A Guanine Nucleotide Exchange Factor for Rap1 Small GTPase

USDA-ARS?s Scientific Manuscript database

Previously, we utilized a microchip array encompassing probes for 14,010 genes of Drosophila melanogaster to analyze the effect of (10R) juvenile hormone III (JH) on genome-wide gene expression in Drosophila S2 cells. Treatment with JH yielded a collection of 32 gene transcripts that demonstrated a ...

Frequent loss of claudin-4 expression in dedifferentiated and undifferentiated endometrial carcinomas.

PubMed

Tessier-Cloutier, Basile; Soslow, Robert A; Stewart, Colin J R; Köbel, Martin; Lee, Cheng-Han

2018-04-19

Dedifferentiated endometrial carcinomas (DDECs)/undifferentiated endometrial carcinomas (UECs) are aggressive endometrial cancers with frequent genomic inactivation of core components of switch/sucrose non-fermentable (SWI/SNF) complex proteins. Claudin-4, an epithelial intercellular tight junction protein, was recently found to be expressed in SWI/SNF-deficient undifferentiated carcinomas but not in SWI/SNF-deficient sarcomas. The aim of this study was to examine claudin-4 expression in UECs/DDECs and other high-grade uterine carcinomas. We examined claudin-4 expression by immunohistochemistry (clone 3E2C1) on tissue microarrays that contained 44 UECs/DDECs (24 SWI/SNF-deficient), 50 carcinosarcomas, 164 grade 3 endometrioid carcinomas, 57 serous carcinomas, and 20 clear cell carcinomas. Tumours with <5% claudin-4 expression were considered to be negative. Nearly all SWI/SNF-deficient, and most SWI/SNF-proficient, UECs/DDECs showed a complete absence of claudin-4 expression in the undifferentiated component, whereas the differentiated component in DDECs showed consistent and diffuse claudin-4 expression. Only one SWI/SNF-deficient DDEC showed focal expression of claudin-4 in the undifferentiated component, as compared with diffuse expression in the corresponding differentiated component. Claudin-4 expression was consistently absent in the sarcomatous component of carcinosarcoma, and it was absent in 24% of grade 3 endometrioid carcinomas and serous carcinomas. Claudin-4 expression can be absent or very focal in a subset of high-grade endometrial carcinomas, and is almost always absent in the undifferentiated components of SWI/SNF-deficient UECs/DDECs, despite the apparent epithelial origin in the case of DDECs. Therefore, claudin-4 expression cannot be used to infer mesenchymal or epithelial tumour origin in the endometrium. The consistent loss or down-regulation of claudin-4, a tight junction protein, in SWI/SNF-deficient UECs/DDECs further supports the undifferentiated nature of these tumours. © 2018 John Wiley & Sons Ltd.

Specification of Drosophila Corpora Cardiaca Neuroendocrine Cells from Mesoderm Is Regulated by Notch Signaling

PubMed Central

Park, Sangbin; Bustamante, Erika L.; Antonova, Julie; McLean, Graeme W.; Kim, Seung K.

2011-01-01

Drosophila neuroendocrine cells comprising the corpora cardiaca (CC) are essential for systemic glucose regulation and represent functional orthologues of vertebrate pancreatic α-cells. Although Drosophila CC cells have been regarded as developmental orthologues of pituitary gland, the genetic regulation of CC development is poorly understood. From a genetic screen, we identified multiple novel regulators of CC development, including Notch signaling factors. Our studies demonstrate that the disruption of Notch signaling can lead to the expansion of CC cells. Live imaging demonstrates localized emergence of extra precursor cells as the basis of CC expansion in Notch mutants. Contrary to a recent report, we unexpectedly found that CC cells originate from head mesoderm. We show that Tinman expression in head mesoderm is regulated by Notch signaling and that the combination of Daughterless and Tinman is sufficient for ectopic CC specification in mesoderm. Understanding the cellular, genetic, signaling, and transcriptional basis of CC cell specification and expansion should accelerate discovery of molecular mechanisms regulating ontogeny of organs that control metabolism. PMID:21901108

Epigenetic Regulation of Learning and Memory by Drosophila EHMT/G9a

PubMed Central

Kramer, Jamie M.; Kochinke, Korinna; Oortveld, Merel A. W.; Marks, Hendrik; Kramer, Daniela; de Jong, Eiko K.; Asztalos, Zoltan; Westwood, J. Timothy; Stunnenberg, Hendrik G.; Sokolowski, Marla B.; Keleman, Krystyna; Zhou, Huiqing; van Bokhoven, Hans; Schenck, Annette

2011-01-01

The epigenetic modification of chromatin structure and its effect on complex neuronal processes like learning and memory is an emerging field in neuroscience. However, little is known about the “writers” of the neuronal epigenome and how they lay down the basis for proper cognition. Here, we have dissected the neuronal function of the Drosophila euchromatin histone methyltransferase (EHMT), a member of a conserved protein family that methylates histone 3 at lysine 9 (H3K9). EHMT is widely expressed in the nervous system and other tissues, yet EHMT mutant flies are viable. Neurodevelopmental and behavioral analyses identified EHMT as a regulator of peripheral dendrite development, larval locomotor behavior, non-associative learning, and courtship memory. The requirement for EHMT in memory was mapped to 7B-Gal4 positive cells, which are, in adult brains, predominantly mushroom body neurons. Moreover, memory was restored by EHMT re-expression during adulthood, indicating that cognitive defects are reversible in EHMT mutants. To uncover the underlying molecular mechanisms, we generated genome-wide H3K9 dimethylation profiles by ChIP-seq. Loss of H3K9 dimethylation in EHMT mutants occurs at 5% of the euchromatic genome and is enriched at the 5′ and 3′ ends of distinct classes of genes that control neuronal and behavioral processes that are corrupted in EHMT mutants. Our study identifies Drosophila EHMT as a key regulator of cognition that orchestrates an epigenetic program featuring classic learning and memory genes. Our findings are relevant to the pathophysiological mechanisms underlying Kleefstra Syndrome, a severe form of intellectual disability caused by mutations in human EHMT1, and have potential therapeutic implications. Our work thus provides novel insights into the epigenetic control of cognition in health and disease. PMID:21245904

Active chromatin and transcription play a key role in chromosome partitioning into topologically associating domains

PubMed Central

Ulianov, Sergey V.; Khrameeva, Ekaterina E.; Gavrilov, Alexey A.; Flyamer, Ilya M.; Kos, Pavel; Mikhaleva, Elena A.; Penin, Aleksey A.; Logacheva, Maria D.; Imakaev, Maxim V.; Chertovich, Alexander; Gelfand, Mikhail S.; Shevelyov, Yuri Y.; Razin, Sergey V.

2016-01-01

Recent advances enabled by the Hi-C technique have unraveled many principles of chromosomal folding that were subsequently linked to disease and gene regulation. In particular, Hi-C revealed that chromosomes of animals are organized into topologically associating domains (TADs), evolutionary conserved compact chromatin domains that influence gene expression. Mechanisms that underlie partitioning of the genome into TADs remain poorly understood. To explore principles of TAD folding in Drosophila melanogaster, we performed Hi-C and poly(A)+ RNA-seq in four cell lines of various origins (S2, Kc167, DmBG3-c2, and OSC). Contrary to previous studies, we find that regions between TADs (i.e., the inter-TADs and TAD boundaries) in Drosophila are only weakly enriched with the insulator protein dCTCF, while another insulator protein Su(Hw) is preferentially present within TADs. However, Drosophila inter-TADs harbor active chromatin and constitutively transcribed (housekeeping) genes. Accordingly, we find that binding of insulator proteins dCTCF and Su(Hw) predicts TAD boundaries much worse than active chromatin marks do. Interestingly, inter-TADs correspond to decompacted inter-bands of polytene chromosomes, whereas TADs mostly correspond to densely packed bands. Collectively, our results suggest that TADs are condensed chromatin domains depleted in active chromatin marks, separated by regions of active chromatin. We propose the mechanism of TAD self-assembly based on the ability of nucleosomes from inactive chromatin to aggregate, and lack of this ability in acetylated nucleosomal arrays. Finally, we test this hypothesis by polymer simulations and find that TAD partitioning may be explained by different modes of inter-nucleosomal interactions for active and inactive chromatin. PMID:26518482

Chemical Activation of the Hypoxia-Inducible Factor Reversibly Reduces Tendon Stem Cell Proliferation, Inhibits Their Differentiation, and Maintains Cell Undifferentiation.

PubMed

Menon, Alessandra; Creo, Pasquale; Piccoli, Marco; Bergante, Sonia; Conforti, Erika; Banfi, Giuseppe; Randelli, Pietro; Anastasia, Luigi

2018-01-01

Adult stem cell-based therapeutic approaches for tissue regeneration have been proposed for several years. However, adult stem cells are usually limited in number and difficult to be expanded in vitro, and they usually tend to quickly lose their potency with passages, as they differentiate and become senescent. Culturing stem cells under reduced oxygen tensions (below 21%) has been proposed as a tool to increase cell proliferation, but many studies reported opposite effects. In particular, cell response to hypoxia seems to be very stem cell type specific. Nonetheless, it is clear that a major role in this process is played by the hypoxia inducible factor (HIF), the master regulator of cell response to oxygen deprivation, which affects cell metabolism and differentiation. Herein, we report that a chemical activation of HIF in human tendon stem cells reduces their proliferation and inhibits their differentiation in a reversible and dose-dependent manner. These results support the notion that hypoxia, by activating HIF, plays a crucial role in preserving stem cells in an undifferentiated state in the "hypoxic niches" present in the tissue in which they reside before migrating in more oxygenated areas to heal a damaged tissue.

Structure of interphase chromosomes in the nuclei of Drosophila cells.

PubMed

Banfalvi, Gaspar

2006-10-01

Fluorescent images of interphase chromatin structures and chromosome structures isolated from reversibly permeable Drosophila cells were analyzed. Decondensed chromatin in early S phase (2.0-2.5 C-value) consisted of a veil-like fibrillary network. Fibrillar chromatin formed rodlets later in the early S phase (2.5-2.75 C). Drosophila chromosomes contain several smaller subunits called rodlets. Fibrillar chromatin turned to chromatin ribbon and the early mid-S-phase globular chromosomes (2.75-3.0 C), then to opened fibrous globular forms later in the mid-S-phase (3.0-3.25 C), to late-S-phase supercoiled ribbons (3.25-3.5 C), end-S-phase elongated prechromosomes (3.5-3.75 C), bent and linear chromosomes (3.75-4.0 C). Early-S phase chromatin fibrils in the nuclei of Drosophila cells are thinner than the veil-like structures in mammalian cells. The connectivity of chromosomes shows linear arrangement (3, 1, 2, 4), with larger chromosomes (1 and 2) inside and smaller chromosomes (3, 4) at the two ends in the chromosomal chain.

The RISC component VIG is a target for dsRNA-independent protein kinase activity in Drosophila S2 cells.

PubMed

Ivanov, Konstantin I; Tselykh, Timofey V; Heino, Tapio I; Mäkinen, Kristiina

2005-07-27

RNA interference (RNAi) is mediated by a multicomponent RNA-induced silencing complex (RISC). Here we examine the phosphorylation state of three Drosophila RISC-associated proteins, VIG, R2D2 and a truncated form of Argonaute2 devoid of the nonconserved N-terminal glutamine-rich domain. We show that of the three studied proteins, only VIG is phosphorylated in cultured Drosophila cells. We also demonstrate that the phosphorylation state of VIG remains unchanged after cell transfection with exogenous dsRNA. A sequence similarity search revealed that VIG shares significant similarity with the human phosphoprotein Ki-1/57, a known in vivo substrate for protein kinase C (PKC). In vitro kinase assays followed by tryptic phosphopeptide mapping showed that PKC could efficiently phosphorylate VIG on multiple sites, suggesting PKC as a candidate kinase for VIG phosphorylation in vivo. Taken together, our results identify the RISC component VIG as a novel kinase substrate in cultured Drosophila cells and suggest a possible involvement of PKC in its phosphorylation.

5-Azacitidine Monotherapy Followed by Related Haploidentical Hematopoietic Stem Cell Transplantation Achieves Durable Remission in a Pediatric Patient With Acute Undifferentiated Leukemia Refractory to High-Dose Chemotherapy.

PubMed

Polishchuk, Veronika; Khazal, Sajad; Berulava, Giorgi; Roth, Michael; Mahadeo, Kris M

2016-06-01

Patients with acute leukemias of undifferentiated lineage (AUL) generally have guarded prognosis. Here, we describe the first reported pediatric patient with AUL refractory to high-dose chemotherapy who achieved clinical remission with ALL maintenance therapy and 5-azacitidine. His induction remission was followed by consolidation with reduced toxicity haploidentical hematopoietic stem cell transplant (HSCT). At 9 months post-HSCT, the patient is alive and in remission. This combination therapy of remission induction with ALL maintenance therapy and 5-azacitidine and consolidation with reduced toxicity haploidentical HSCT is novel and promising for patients who lack conventional donors and are not candidates for myeloablative therapy. © 2016 Wiley Periodicals, Inc.

Scrambled Eggs: Apoptotic Cell Clearance by Non-Professional Phagocytes in the Drosophila Ovary.

PubMed

Serizier, Sandy B; McCall, Kimberly

2017-01-01

For half of a century, it has been known that non-professional phagocytes, such as fibroblasts, endothelial, and epithelial cells, are capable of efferocytosis (engulfment of apoptotic cells). Non-professional phagocytes differ from professional phagocytes in the range and efficiency of engulfment. Much of the recognition and underlying signaling machinery between non-professional and professional phagocytes is the same, but it is not known how the engulfment capacity of non-professional phagocytes is controlled. Moreover, the signaling networks involved in cell corpse recognition, engulfment, and phagosome maturation are only partially understood. The Drosophila ovary provides an excellent system to investigate the regulation of phagocytic activity by epithelial cells, a major class of non-professional phagocytes. During Drosophila oogenesis, mid-stage egg chambers undergo apoptosis of the germline in response to nutrient deprivation. Epithelial follicle cells then undergo major cell shape changes and concomitantly engulf the germline material. Our previous work has established that Draper and the integrin α-PS3/β-PS heterodimer are required in follicle cells for germline cell clearance. In addition, we have characterized phagosome maturation pathways, and found that the JNK pathway amplifies the engulfment response. In this review, we discuss recent advances on the interplay between engulfment pathways in the follicular epithelium for cell clearance in the Drosophila ovary. We also provide a comparison to apoptotic cell clearance mechanisms in C. elegans and mammals, illustrating strong conservation of efferocytosis mechanisms by non-professional phagocytes.

Scrambled Eggs: Apoptotic Cell Clearance by Non-Professional Phagocytes in the Drosophila Ovary

PubMed Central

Serizier, Sandy B.; McCall, Kimberly

2017-01-01

For half of a century, it has been known that non-professional phagocytes, such as fibroblasts, endothelial, and epithelial cells, are capable of efferocytosis (engulfment of apoptotic cells). Non-professional phagocytes differ from professional phagocytes in the range and efficiency of engulfment. Much of the recognition and underlying signaling machinery between non-professional and professional phagocytes is the same, but it is not known how the engulfment capacity of non-professional phagocytes is controlled. Moreover, the signaling networks involved in cell corpse recognition, engulfment, and phagosome maturation are only partially understood. The Drosophila ovary provides an excellent system to investigate the regulation of phagocytic activity by epithelial cells, a major class of non-professional phagocytes. During Drosophila oogenesis, mid-stage egg chambers undergo apoptosis of the germline in response to nutrient deprivation. Epithelial follicle cells then undergo major cell shape changes and concomitantly engulf the germline material. Our previous work has established that Draper and the integrin α-PS3/β-PS heterodimer are required in follicle cells for germline cell clearance. In addition, we have characterized phagosome maturation pathways, and found that the JNK pathway amplifies the engulfment response. In this review, we discuss recent advances on the interplay between engulfment pathways in the follicular epithelium for cell clearance in the Drosophila ovary. We also provide a comparison to apoptotic cell clearance mechanisms in C. elegans and mammals, illustrating strong conservation of efferocytosis mechanisms by non-professional phagocytes. PMID:29238344

Differentiation of Drosophila glial cells.

PubMed

Sasse, Sofia; Neuert, Helen; Klämbt, Christian

2015-01-01

Glial cells are important constituents of the nervous system and a hallmark of these cells are their pronounced migratory abilities. In Drosophila, glial lineages have been well described and some of the molecular mechanisms necessary to guide migrating glial cells to their final target sites have been identified. With the onset of migration, glial cells are already specified into one of five main glial cell types. The perineurial and subperineurial glial cells are eventually located at the outer surface of the Drosophila nervous system and constitute the blood-brain barrier. The cortex glial cells ensheath all neuroblasts and their progeny and reside within the central nervous system. Astrocyte-like cells invade the neuropil to control synaptic function and ensheathing glial cells encase the entire neuropil. Within the peripheral nervous system, wrapping glial cells ensheath individual axons or axon fascicles. Here, we summarize the current knowledge on how differentiation of glial cells into the specific subtypes is orchestrated. Furthermore, we discuss sequencing data that will facilitate further analyses of glial differentiation in the fly nervous system. © 2015 Wiley Periodicals, Inc.

Germanium abundances in lunar basalts: Evidence of mantle metasomatism

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

Dickinson, T.; Taylor, G.J.; Keil, T.K.

1988-01-01

To fill in gaps in the present Ge data base, mare basalts were analyzed for Ge and other elements by RNAA and INAA. Mare basalts from Apollo 11, 12, 15, 17 landing sites are rather uniform in Ge abundance, but Apollo 14 aluminous mare basalts and KREEP are enriched in Ge by factors of up to 300 compared to typical mare basalts. These Ge enrichments are not associated with other siderophile element enrichments and, thus, are not due to differences in the amount of metal segregated during core formation. Based on crystal-chemical and inter-element variations, it does not appear thatmore » the observed Ge enrichments are due to silicate liquid immiscibility. Elemental ratios in Apollo 14 aluminous mare basalts, green and orange glass, average basalts and KREEP suggest that incorporation of late accreting material into the source regions or interaction of the magmas with primitive undifferentiated material is not a likely cause for the observed Ge enrichments. We speculate that the most plausible explanation for these Ge enrichments is complexing and concentration of Ge by F, Cl or S in volatile phases. In this manner, the KREEP basalt source regions may have been metasomatized and Apollo 14 aluminous mare basalt magmas may have become enriched in Ge by interacting with these metasomatized areas. The presence of volatile- and Ge-rich regions in the Moon suggests that the Moon was never totally molten. 71 refs., 1 fig., 6 tabs.« less

Single-cell analysis of the fate of c-kit-positive bone marrow cells

NASA Astrophysics Data System (ADS)

Czarna, Anna; Sanada, Fumihiro; Matsuda, Alex; Kim, Junghyun; Signore, Sergio; Pereira, João D.; Sorrentino, Andrea; Kannappan, Ramaswamy; Cannatà, Antonio; Hosoda, Toru; Rota, Marcello; Crea, Filippo; Anversa, Piero; Leri, Annarosa

2017-10-01

The plasticity of c-kit-positive bone marrow cells (c-kit-BMCs) in tissues different from their organ of origin remains unclear. We tested the hypothesis that c-kit-BMCs are functionally heterogeneous and only a subgroup of these cells possesses cardiomyogenic potential. Population-based assays fall short of identifying the properties of individual stem cells, imposing on us the introduction of single cell-based approaches to track the fate of c-kit-BMCs in the injured heart; they included viral gene-tagging, multicolor clonal-marking and transcriptional profiling. Based on these strategies, we report that single mouse c-kit-BMCs expand clonally within the infarcted myocardium and differentiate into specialized cardiac cells. Newly-formed cardiomyocytes, endothelial cells, fibroblasts and c-kit-BMCs showed in their genome common sites of viral integration, providing strong evidence in favor of the plasticity of a subset of BMCs expressing the c-kit receptor. Similarly, individual c-kit-BMCs, which were infected with multicolor reporters and injected in infarcted hearts, formed cardiomyocytes and vascular cells organized in clusters of similarly colored cells. The uniform distribution of fluorescent proteins in groups of specialized cells documented the polyclonal nature of myocardial regeneration. The transcriptional profile of myogenic c-kit-BMCs and whole c-kit-BMCs was defined by RNA sequencing. Genes relevant for engraftment, survival, migration, and differentiation were enriched in myogenic c-kit-BMCs, a cell subtype which could not be assigned to a specific hematopoietic lineage. Collectively, our findings demonstrate that the bone marrow comprises a category of cardiomyogenic, vasculogenic and/or fibrogenic c-kit-positive cells and a category of c-kit-positive cells that retains an undifferentiated state within the damaged heart.

Longitudinal tracking of subpopulation dynamics and molecular changes during LNCaP cell castration and identification of inhibitors that could target the PSA-/lo castration-resistant cells.

PubMed

Rycaj, Kiera; Cho, Eun Jeong; Liu, Xin; Chao, Hsueh-Ping; Liu, Bigang; Li, Qiuhui; Devkota, Ashwini K; Zhang, Dingxiao; Chen, Xin; Moore, John; Dalby, Kevin N; Tang, Dean G

2016-03-22

We have recently demonstrated that the undifferentiated PSA-/lo prostate cancer (PCa) cell population harbors self-renewing long-term tumor-propagating cells that are refractory to castration, thus representing a therapeutic target. Our goals here are, by using the same lineage-tracing reporter system, to track the dynamic changes of PSA-/lo and PSA+ cells upon castration in vitro, investigate the molecular changes accompanying persistent castration, and develop large numbers of PSA-/lo PCa cells for drug screening. To these ends, we treated LNCaP cells infected with the PSAP-GFP reporter with three regimens of castration, i.e., CDSS, CDSS plus bicalutamide, and MDV3100 continuously for up to ~21 months. We observed that in the first ~7 months, castration led to time-dependent increases in PSA-/lo cells, loss of AR and PSA expression, increased expression of cancer stem cell markers, and many other molecular changes. Meanwhile, castrated LNCaP cells became resistant to high concentrations of MDV3100, chemotherapeutic drugs, and other agents. However, targeted and medium-throughput library screening identified several kinase (e.g., IGF-1R, AKT, PI3K/mTOR, Syk, GSK3) inhibitors as well as the BCL2 inhibitor that could effectively sensitize the LNCaP-CRPC cells to killing. Of interest, LNCaP cells castrated for >7 months showed evidence of cyclic changes in AR and the mTOR/AKT signaling pathways potentially involving epigenetic mechanisms. These observations indicate that castration elicits numerous molecular changes and leads to enrichment of PSA-/lo PCa cells. The ability to generate large numbers of PSA-/lo PCa cells should allow future high-throughput screening to identify novel therapeutics that specifically target this population.

Single-cell analysis of the fate of c-kit-positive bone marrow cells.

PubMed

Czarna, Anna; Sanada, Fumihiro; Matsuda, Alex; Kim, Junghyun; Signore, Sergio; Pereira, João D; Sorrentino, Andrea; Kannappan, Ramaswamy; Cannatà, Antonio; Hosoda, Toru; Rota, Marcello; Crea, Filippo; Anversa, Piero; Leri, Annarosa

2017-01-01

The plasticity of c-kit-positive bone marrow cells (c-kit-BMCs) in tissues different from their organ of origin remains unclear. We tested the hypothesis that c-kit-BMCs are functionally heterogeneous and only a subgroup of these cells possesses cardiomyogenic potential. Population-based assays fall short of identifying the properties of individual stem cells, imposing on us the introduction of single cell-based approaches to track the fate of c-kit-BMCs in the injured heart; they included viral gene-tagging, multicolor clonal-marking and transcriptional profiling. Based on these strategies, we report that single mouse c-kit-BMCs expand clonally within the infarcted myocardium and differentiate into specialized cardiac cells. Newly-formed cardiomyocytes, endothelial cells, fibroblasts and c-kit-BMCs showed in their genome common sites of viral integration, providing strong evidence in favor of the plasticity of a subset of BMCs expressing the c-kit receptor. Similarly, individual c-kit-BMCs, which were infected with multicolor reporters and injected in infarcted hearts, formed cardiomyocytes and vascular cells organized in clusters of similarly colored cells. The uniform distribution of fluorescent proteins in groups of specialized cells documented the polyclonal nature of myocardial regeneration. The transcriptional profile of myogenic c-kit-BMCs and whole c-kit-BMCs was defined by RNA sequencing. Genes relevant for engraftment, survival, migration, and differentiation were enriched in myogenic c-kit-BMCs, a cell subtype which could not be assigned to a specific hematopoietic lineage. Collectively, our findings demonstrate that the bone marrow comprises a category of cardiomyogenic, vasculogenic and/or fibrogenic c-kit-positive cells and a category of c-kit-positive cells that retains an undifferentiated state within the damaged heart.

Longitudinal tracking of subpopulation dynamics and molecular changes during LNCaP cell castration and identification of inhibitors that could target the PSA−/lo castration-resistant cells

PubMed Central

Rycaj, Kiera; Cho, Eun Jeong; Liu, Xin; Chao, Hsueh-Ping; Liu, Bigang; Li, Qiuhui; Devkota, Ashwini K.; Zhang, Dingxiao; Chen, Xin; Moore, John; Dalby, Kevin N.; Tang, Dean G.

2016-01-01

We have recently demonstrated that the undifferentiated PSA−/lo prostate cancer (PCa) cell population harbors self-renewing long-term tumor-propagating cells that are refractory to castration, thus representing a therapeutic target. Our goals here are, by using the same lineage-tracing reporter system, to track the dynamic changes of PSA−/lo and PSA+ cells upon castration in vitro, investigate the molecular changes accompanying persistent castration, and develop large numbers of PSA−/lo PCa cells for drug screening. To these ends, we treated LNCaP cells infected with the PSAP-GFP reporter with three regimens of castration, i.e., CDSS, CDSS plus bicalutamide, and MDV3100 continuously for up to ~21 months. We observed that in the first ~7 months, castration led to time-dependent increases in PSA−/lo cells, loss of AR and PSA expression, increased expression of cancer stem cell markers, and many other molecular changes. Meanwhile, castrated LNCaP cells became resistant to high concentrations of MDV3100, chemotherapeutic drugs, and other agents. However, targeted and medium-throughput library screening identified several kinase (e.g., IGF-1R, AKT, PI3K/mTOR, Syk, GSK3) inhibitors as well as the BCL2 inhibitor that could effectively sensitize the LNCaP-CRPC cells to killing. Of interest, LNCaP cells castrated for >7 months showed evidence of cyclic changes in AR and the mTOR/AKT signaling pathways potentially involving epigenetic mechanisms. These observations indicate that castration elicits numerous molecular changes and leads to enrichment of PSA−/lo PCa cells. The ability to generate large numbers of PSA−/lo PCa cells should allow future high-throughput screening to identify novel therapeutics that specifically target this population. PMID:26871947

Insulin-independent role of adiponectin receptor signaling in Drosophila germline stem cell maintenance.

PubMed

Laws, Kaitlin M; Sampson, Leesa L; Drummond-Barbosa, Daniela

2015-03-15

Adipocytes have key endocrine roles, mediated in large part by secreted protein hormones termed adipokines. The adipokine adiponectin is well known for its role in sensitizing peripheral tissues to insulin, and several lines of evidence suggest that adiponectin might also modulate stem cells/precursors. It remains unclear, however, how adiponectin signaling controls stem cells and whether this role is secondary to its insulin-sensitizing effects or distinct. Drosophila adipocytes also function as an endocrine organ and, although no obvious adiponectin homolog has been identified, Drosophila AdipoR encodes a well-conserved homolog of mammalian adiponectin receptors. Here, we generate a null AdipoR allele and use clonal analysis to demonstrate an intrinsic requirement for AdipoR in germline stem cell (GSC) maintenance in the Drosophila ovary. AdipoR null GSCs are not fully responsive to bone morphogenetic protein ligands from the niche and have a slight reduction in E-cadherin levels at the GSC-niche junction. Conversely, germline-specific overexpression of AdipoR inhibits natural GSC loss, suggesting that reduction in adiponectin signaling might contribute to the normal decline in GSC numbers observed over time in wild-type females. Surprisingly, AdipoR is not required for insulin sensitization of the germline, leading us to speculate that insulin sensitization is a more recently acquired function than stem cell regulation in the evolutionary history of adiponectin signaling. Our findings establish Drosophila female GSCs as a new system for future studies addressing the molecular mechanisms whereby adiponectin receptor signaling modulates stem cell fate. Copyright © 2015 Elsevier Inc. All rights reserved.

Expression and function of orphan nuclear receptor TLX in adult neural stem cells.

PubMed

Shi, Yanhong; Chichung Lie, D; Taupin, Philippe; Nakashima, Kinichi; Ray, Jasodhara; Yu, Ruth T; Gage, Fred H; Evans, Ronald M

2004-01-01

The finding of neurogenesis in the adult brain led to the discovery of adult neural stem cells. TLX was initially identified as an orphan nuclear receptor expressed in vertebrate forebrains and is highly expressed in the adult brain. The brains of TLX-null mice have been reported to have no obvious defects during embryogenesis; however, mature mice suffer from retinopathies, severe limbic defects, aggressiveness, reduced copulation and progressively violent behaviour. Here we show that TLX maintains adult neural stem cells in an undifferentiated, proliferative state. We show that TLX-expressing cells isolated by fluorescence-activated cell sorting (FACS) from adult brains can proliferate, self-renew and differentiate into all neural cell types in vitro. By contrast, TLX-null cells isolated from adult mutant brains fail to proliferate. Reintroducing TLX into FACS-sorted TLX-null cells rescues their ability to proliferate and to self-renew. In vivo, TLX mutant mice show a loss of cell proliferation and reduced labelling of nestin in neurogenic areas in the adult brain. TLX can silence glia-specific expression of the astrocyte marker GFAP in neural stem cells, suggesting that transcriptional repression may be crucial in maintaining the undifferentiated state of these cells.

Exploring the Conserved Role of MANF in the Unfolded Protein Response in Drosophila melanogaster

PubMed Central

Lindström, Riitta; Lindholm, Päivi; Kallijärvi, Jukka; Palgi, Mari; Saarma, Mart; Heino, Tapio I.

2016-01-01

Disturbances in the homeostasis of endoplasmic reticulum (ER) referred to as ER stress is involved in a variety of human diseases. ER stress activates unfolded protein response (UPR), a cellular mechanism the purpose of which is to restore ER homeostasis. Previous studies show that Mesencephalic Astrocyte-derived Neurotrophic Factor (MANF) is an important novel component in the regulation of UPR. In vertebrates, MANF is upregulated by ER stress and protects cells against ER stress-induced cell death. Biochemical studies have revealed an interaction between mammalian MANF and GRP78, the major ER chaperone promoting protein folding. In this study we discovered that the upregulation of MANF expression in response to drug-induced ER stress is conserved between Drosophila and mammals. Additionally, by using a genetic in vivo approach we found genetic interactions between Drosophila Manf and genes encoding for Drosophila homologues of GRP78, PERK and XBP1, the key components of UPR. Our data suggest a role for Manf in the regulation of Drosophila UPR. PMID:26975047

Environmental Presence of Hexavalent but Not Trivalent Chromium Causes Neurotoxicity in Exposed Drosophila melanogaster.

PubMed

Singh, Pallavi; Chowdhuri, D Kar

2017-07-01

A number of environmental chemicals are known to cause neurotoxicity to exposed organisms. Chromium (Cr), one of the major elements in earth's crust, is a priority environmental chemical depending on its valence state, and limited information is available on its neurotoxic potential. We, therefore, explored the neurotoxic potential of environmentally present trivalent- (Cr(III)) and hexavalent-Cr (Cr(VI)) on tested brain cell types in a genetically tractable organism Drosophila melanogaster along with its organismal response. Third instar larvae of w 1118 were fed environmentally relevant concentrations (5.0-20.0 μg/ml) of Cr(III)- or Cr(VI)-salt-mixed food for 24 and 48 h, and their exposure effects were examined in different brain cells of exposed organism. A significant reduction in the number of neuronal cells was observed in organism that were fed Cr(VI)- but not Cr(III)-salt-mixed food. Interestingly, glial cells were not affected by Cr(III) or Cr(VI) exposure. The tested cholinergic and dopaminergic neuronal cells were affected by Cr(VI) only with the later by 20.0 μg/ml Cr(VI) exposure after 48 h. The locomotor activity was significantly affected by Cr(VI) in exposed organism. Concomitantly, a significant increase in the level of reactive oxygen species (ROS) coupled with increased oxidative stress led to apoptotic cell death in the tested brain cells of Cr(VI)-exposed Drosophila, which were reversed by vitamin C supplementation. Conclusively, the present study provides evidence of environmental Cr(VI)-induced adversities on the brain of exposed Drosophila along with behavioral deficit which would likely to have relevance in humans and recommends Drosophila as a model for neurotoxicity.

Tissue engineering-based cartilage repair with mesenchymal stem cells in a porcine model.

PubMed

Chang, Chih-Hung; Kuo, Tzong-Fu; Lin, Feng-Huei; Wang, Jyh-Horng; Hsu, Yuan-Ming; Huang, Huei-Ting; Loo, Shiao-Tung; Fang, Hsu-Wei; Liu, Hwa-Chang; Wang, Wen-Chih

2011-12-01

This in vivo pilot study explored the use of mesenchymal stem cell (MSC) containing tissue engineering constructs in repair of osteochondral defects. Osteochondral defects were created in the medial condyles of both knees of 16 miniature pigs. One joint received a cell/collagen tissue engineering construct with or without pretreatment with transforming growth factor β (TGF-β) and the other joint from the same pig received no treatment or the gel scaffold only. Six months after surgery, in knees with no treatment, all defects showed contracted craters; in those treated with the gel scaffold alone, six showed a smooth gross surface, one a hypertrophic surface, and one a contracted crater; in those with undifferentiated MSCs, five defects had smooth, fully repaired surfaces or partially repaired surfaces, and one defect poor repair; in those with TGF-β-induced differentiated MSCs, seven defects had smooth, fully repaired surfaces or partially repaired surfaces, and three defects showed poor repair. In Pineda score grading, the group with undifferentiated MSC, but not the group with TGF-β-induced differentiated MSCs, had significantly lower subchondral, cell morphology, and total scores than the groups with no or gel-only treatment. The compressive stiffness was larger in cartilage without surgical treatment than the treated area within each group. In conclusion, this preliminary pilot study suggests that using undifferentiated MSCs might be a better approach than using TGF-β-induced differentiated MSCs for in vivo tissue engineered treatment of osteochondral defects. Copyright © 2011 Orthopaedic Research Society.

Drosophila S2 cells secrete wingless on exosome-like vesicles but the wingless gradient forms independently of exosomes.

PubMed

Beckett, Karen; Monier, Solange; Palmer, Lucy; Alexandre, Cyrille; Green, Hannah; Bonneil, Eric; Raposo, Graca; Thibault, Pierre; Le Borgne, Roland; Vincent, Jean-Paul

2013-01-01

Wingless acts as a morphogen in Drosophila wing discs, where it specifies cell fates and controls growth several cell diameters away from its site of expression. Thus, despite being acylated and membrane associated, Wingless spreads in the extracellular space. Recent studies have focussed on identifying the route that Wingless follows in the secretory pathway and determining how it is packaged for release. We have found that, in medium conditioned by Wingless-expressing Drosophila S2 cells, Wingless is present on exosome-like vesicles and that this fraction activates signal transduction. Proteomic analysis shows that Wingless-containing exosome-like structures contain many Drosophila proteins that are homologous to mammalian exosome proteins. In addition, Evi, a multipass transmembrane protein, is also present on exosome-like vesicles. Using these exosome markers and a cell-based RNAi assay, we found that the small GTPase Rab11 contributes significantly to exosome production. This finding allows us to conclude from in vivo Rab11 knockdown experiments, that exosomes are unlikely to contribute to Wingless secretion and gradient formation in wing discs. Consistent with this conclusion, extracellularly tagged Evi expressed from a Bacterial Artificial Chromosome is not released from imaginal disc Wingless-expressing cells. © 2012 John Wiley & Sons A/S.

Ras promotes cell survival by antagonizing both JNK and Hid signals in the Drosophila eye.

PubMed

Wu, Yue; Zhuang, Yuan; Han, Min; Xu, Tian; Deng, Kejing

2009-10-20

Programmed cell death, or apoptosis, is a fundamental physiological process during normal development or in pathological conditions. The activation of apoptosis can be elicited by numerous signalling pathways. Ras is known to mediate anti-apoptotic signals by inhibiting Hid activity in the Drosophila eye. Here we report the isolation of a new loss-of-function ras allele, rasKP, which causes excessive apoptosis in the Drosophila eye. This new function is likely to be mediated through the JNK pathway since the inhibition of JNK signalling can significantly suppress rasKP-induced apoptosis, whereas the removal of hid only weakly suppresses the phenotype. Furthermore, the reduction of JNK signalling together with the expression of the baculovirus caspase inhibitor p35, which blocks Hid activity, strongly suppresses the rasKP cell death. In addition, we find a strong correlation between rasKP-induced apoptosis in the eye disc and the activation of JNK signalling. In the Drosophila eye, Ras may protect cells from apoptosis by inhibiting both JNK and Hid activities. Surprisingly, reducing Ras activity in the wing, however, does not cause apoptosis but rather affects cell and organ size. Thus, in addition to its requirement for cell viability, Ras appears to mediate different biological roles depending on the developmental context and on the level of its expression.

Activation of EGF Receptor Kinase by L1-mediated Homophilic Cell Interactions

PubMed Central

Islam, Rafique; Kristiansen, Lars V.; Romani, Susana; Garcia-Alonso, Luis; Hortsch, Michael

2004-01-01

Neural cell adhesion molecules (CAMs) are important players during neurogenesis and neurite outgrowth as well as axonal fasciculation and pathfinding. Some of these developmental processes entail the activation of cellular signaling cascades. Pharmacological and genetic evidence indicates that the neurite outgrowth-promoting activity of L1-type CAMs is at least in part mediated by the stimulation of neuronal receptor tyrosine kinases (RTKs), especially FGF and EGF receptors. It has long been suspected that neural CAMs might physically interact with RTKs, but their activation by specific cell adhesion events has not been directly demonstrated. Here we report that gain-of-function conditions of the Drosophila L1-type CAM Neuroglian result in profound sensory axon pathfinding defects in the developing Drosophila wing. This phenotype can be suppressed by decreasing the normal gene dosage of the Drosophila EGF receptor gene. Furthermore, in Drosophila S2 cells, cell adhesion mediated by human L1-CAM results in the specific activation of human EGF tyrosine kinase at cell contact sites and EGF receptors engage in a physical interaction with L1-CAM molecules. Thus L1-type CAMs are able to promote the adhesion-dependent activation of EGF receptor signaling in vitro and in vivo. PMID:14718570

Dedifferentiated endometrial carcinomas with neuroendocrine features: a clinicopathologic, immunohistochemical, and molecular genetic study.

PubMed

Espinosa, Iñigo; De Leo, Antonio; D'Angelo, Emanuela; Rosa-Rosa, Juan M; Corominas, Marina; Gonzalez, Alan; Palacios, José; Prat, Jaime

2018-02-01

Undifferentiated endometrial carcinoma is an aggressive type of uterine cancer, which is occasionally associated with a low-grade endometrioid carcinoma component. This combination is referred to as "dedifferentiated endometrioid endometrial carcinoma." Neuroendocrine expression may occur in undifferentiated endometrial carcinoma, but its significance in dedifferentiated endometrial carcinomas is unknown. To gain insight into the pathogenesis of these tumors we have analyzed the immunophenotype (ARID1A, MLH1, PMS2, MSH2, MSH6, p53, β-catenin, SMARCB1, synaptophysin, chromogranin A, and CD56) and mutational status (PTEN, KRAS, PIK3CA, TP53 and POLE) of 4 dedifferentiated endometrial carcinomas with strong and diffuse neuroendocrine expression. All tumors demonstrated neuroendocrine expression in ≥70% of the cells in the undifferentiated carcinoma areas. Loss of expression of at least 1 DNA mismatch repair protein was observed in 2 cases, and p53 immunoreaction was aberrant (mutated/inactivated) in one case. All carcinomas were negative for β-catenin and maintained nuclear SMARCB1 (INI1) and ARID1A expression. Three tumors shared identical endometrioid molecular profile (PTEN and/or PIK3CA mutations) in both components. One tumor had POLE exonuclease domain mutation in the undifferentiated component. In one case, TP53 mutation was found exclusively in the undifferentiated component. Two patients died with peritoneal carcinomatosis and abdominal metastases, respectively; one patient died of a renal failure without evidence of disease, and the last patient is alive and free of disease at 3.3 years. Dedifferentiated endometrial carcinomas with neuroendocrine features are clinically and molecularly heterogeneous tumors. Probably, these carcinomas might acquire undifferentiated phenotype through mutations in TP53 and POLE. Copyright © 2017 Elsevier Inc. All rights reserved.

Multiple strategies of oxygen supply in Drosophila malignancies identify tracheogenesis as a novel cancer hallmark.

PubMed

Grifoni, Daniela; Sollazzo, Manuela; Fontana, Elisabetta; Froldi, Francesca; Pession, Annalisa

2015-03-12

Angiogenesis is the term used to describe all the alterations in blood vessel growth induced by a tumour mass following hypoxic stress. The occurrence of multiple strategies of vessel recruitment favours drug resistance, greatly complicating the treatment of certain tumours. In Drosophila, oxygen is conveyed to the internal organs by the tracheal system, a closed tubular network whose role in cancer growth is so far unexplored. We found that, as observed in human cancers, Drosophila malignant cells suffer from oxygen shortage, release pro-tracheogenic factors, co-opt nearby vessels and get incorporated into the tracheal walls. We also found that the parallelisms observed in cellular behaviours are supported by genetic and molecular conservation. Finally, we identified a molecular circuitry associated with the differentiation of cancer cells into tracheal cells. In summary, our findings identify tracheogenesis as a novel cancer hallmark in Drosophila, further expanding the power of the fly model in cancer research.

Drosophila non-muscle myosin II motor activity determines the rate of tissue folding

PubMed Central

Vasquez, Claudia G; Heissler, Sarah M; Billington, Neil; Sellers, James R; Martin, Adam C

2016-01-01

Non-muscle cell contractility is critical for tissues to adopt shape changes. Although, the non-muscle myosin II holoenzyme (myosin) is a molecular motor that powers contraction of actin cytoskeleton networks, recent studies have questioned the importance of myosin motor activity cell and tissue shape changes. Here, combining the biochemical analysis of enzymatic and motile properties for purified myosin mutants with in vivo measurements of apical constriction for the same mutants, we show that in vivo constriction rate scales with myosin motor activity. We show that so-called phosphomimetic mutants of the Drosophila regulatory light chain (RLC) do not mimic the phosphorylated RLC state in vitro. The defect in the myosin motor activity in these mutants is evident in developing Drosophila embryos where tissue recoil following laser ablation is decreased compared to wild-type tissue. Overall, our data highlights that myosin activity is required for rapid cell contraction and tissue folding in developing Drosophila embryos. DOI: http://dx.doi.org/10.7554/eLife.20828.001 PMID:28035903

Drosophila neuroglian: a member of the immunoglobulin superfamily with extensive homology to the vertebrate neural adhesion molecule L1.

PubMed

Bieber, A J; Snow, P M; Hortsch, M; Patel, N H; Jacobs, J R; Traquina, Z R; Schilling, J; Goodman, C S

1989-11-03

Drosophila neuroglian is an integral membrane glycoprotein that is expressed on a variety of cell types in the Drosophila embryo, including expression on a large subset of glial and neuronal cell bodies in the central and peripheral nervous systems and on the fasciculating axons that extend along them. Neuroglian cDNA clones were isolated by expression cloning. cDNA sequence analysis reveals that neuroglian is a member of the immunoglobulin superfamily. The extracellular portion of the protein consists of six immunoglobulin C2-type domains followed by five fibronectin type III domains. Neuroglian is closely related to the immunoglobulin-like vertebrate neural adhesion molecules and, among them, shows most extensive homology to mouse L1. Its homology to L1 and its embryonic localization suggest that neuroglian may play a role in neural and glial cell adhesion in the developing Drosophila embryo. We report here on the identification of a lethal mutation in the neuroglian gene.

Myeloid leukemia factor is a conserved regulator of RUNX transcription factor activity involved in hematopoiesis.

PubMed

Bras, Stéphanie; Martin-Lannerée, Séverine; Gobert, Vanessa; Augé, Benoît; Breig, Osman; Sanial, Matthieu; Yamaguchi, Masamitsu; Haenlin, Marc; Plessis, Anne; Waltzer, Lucas

2012-03-27

Defining the function of the genes that, like RUNX1, are deregulated in blood cell malignancies represents an important challenge. Myeloid leukemia factors (MLFs) constitute a poorly characterized family of conserved proteins whose founding member, MLF1, has been associated with acute myeloid leukemia in humans. To gain insight into the functions of this family, we investigated the role of the Drosophila MLF homolog during blood cell development. Here we report that mlf controls the homeostasis of the Drosophila hematopoietic system. Notably, mlf participates in a positive feedback loop to fine tune the activity of the RUNX transcription factor Lozenge (LZ) during development of the crystal cells, one of the two main blood cell lineages in Drosophila. At the molecular level, our data in cell cultures and in vivo strongly suggest that MLF controls the number of crystal cells by protecting LZ from degradation. Remarkably, it appears that the human MLF1 protein can substitute for MLF in the crystal cell lineage. In addition, MLF stabilizes the human oncogenic fusion protein RUNX1-ETO and is required for RUNX1-ETO-induced blood cell disorders in a Drosophila model of leukemia. Finally, using the human leukemic blood cell line Kasumi-1, we show that MLF1 depletion impairs RUNX1-ETO accumulation and reduces RUNX1-ETO-dependent proliferation. Thus, we propose that the regulation of RUNX protein levels is a conserved feature of MLF family members that could be critical for normal and pathological blood cell development.

The cytoplasmic domain of the Drosophila cell adhesion molecule neuroglian is not essential for its homophilic adhesive properties in S2 cells.

PubMed

Hortsch, M; Wang, Y M; Marikar, Y; Bieber, A J

1995-08-11

Drosophila neuroglian is a transmembrane glycoprotein that has strong structural and sequence homology to the vertebrate L1 gene family of cell adhesion molecules (Bieber, A.J., Snow, P.M., Hortsch, M., Patel, N.H., Jacobs, J.R., Traquina, Z.R., Schilling, J., and Goodman, C.S. (1989) Cell 59, 447-460. Two different neuroglian protein forms that are generated by a differential splicing process are expressed in a tissue-specific fashion by embryonic and larval cells (Hortsch, M., Bieber, A.J., Patel, N.H., and Goodman, C.S. (1990) Neuron 4, 697-709). The two neuroglial polypeptides differ only in their cytoplasmic domains. Both of these neuroglian species, when transfected into the expressed in Drosophila S2 cells, induce the calcium-independent, homophilic aggregation of transformed cells. A third artificial neuroglian protein form was constructed by substituting the neuroglian transmembrane segment and cytoplasmic domains with the glycosyl phosphatidylinositol attachment signal of the Drosophila fasciclin I protein. This cDNA construct generates a glycosyl phosphatidylinositol-anchored form of neuroglian, which retains the ability to induce homophilic cell aggregation when expressed in S2 cells, and was able to interact with both of the two naturally occurring neuroglian polypeptides. These results demonstrate that neuroglian mediates a calcium-independent, homophilic cell adhesion activity and that neither cytoplasmic neuroglian domains nor a direct interaction with cytoskeletal elements is essential for this property.

The deubiquitinating enzyme DUBAI stabilizes DIAP1 to suppress Drosophila apoptosis

PubMed Central

Yang, C-S; Sinenko, S A; Thomenius, M J; Robeson, A C; Freel, C D; Horn, S R; Kornbluth, S

2014-01-01

Deubiquitinating enzymes (DUBs) counteract ubiquitin ligases to modulate the ubiquitination and stability of target signaling molecules. In Drosophila, the ubiquitin–proteasome system has a key role in the regulation of apoptosis, most notably, by controlling the abundance of the central apoptotic regulator DIAP1. Although the mechanism underlying DIAP1 ubiquitination has been extensively studied, the precise role of DUB(s) in controlling DIAP1 activity has not been fully investigated. Here we report the identification of a DIAP1-directed DUB using two complementary approaches. First, a panel of putative Drosophila DUBs was expressed in S2 cells to determine whether DIAP1 could be stabilized, despite treatment with death-inducing stimuli that would induce DIAP1 degradation. In addition, RNAi fly lines were used to detect modifiers of DIAP1 antagonist-induced cell death in the developing eye. Together, these approaches identified a previously uncharacterized protein encoded by CG8830, which we named DeUBiquitinating-Apoptotic-Inhibitor (DUBAI), as a novel DUB capable of preserving DIAP1 to dampen Drosophila apoptosis. DUBAI interacts with DIAP1 in S2 cells, and the putative active site of its DUB domain (C367) is required to rescue DIAP1 levels following apoptotic stimuli. DUBAI, therefore, represents a novel locus of apoptotic regulation in Drosophila, antagonizing cell death signals that would otherwise result in DIAP1 degradation. PMID:24362437

Comprehensive functional analysis of Rab GTPases in Drosophila nephrocytes.

PubMed

Fu, Yulong; Zhu, Jun-Yi; Zhang, Fujian; Richman, Adam; Zhao, Zhanzheng; Han, Zhe

2017-06-01

The Drosophila nephrocyte is a critical component of the fly renal system and bears structural and functional homology to podocytes and proximal tubule cells of the mammalian kidney. Investigations of nephrocyte cell biological processes are fundamental to understanding the insect renal system. Nephrocytes are highly active in endocytosis and vesicle trafficking. Rab GTPases regulate endocytosis and trafficking but specific functions of nephrocyte Rabs remain undefined. We analyzed Rab GTPase expression and function in Drosophila nephrocytes and found that 11 out of 27 Drosophila Rabs were required for normal activity. Rabs 1, 5, 7, 11 and 35 were most important. Gene silencing of the nephrocyte-specific Rab5 eliminated all intracellular vesicles and the specialized plasma membrane structures essential for nephrocyte function. Rab7 silencing dramatically increased clear vacuoles and reduced lysosomes. Rab11 silencing increased lysosomes and reduced clear vacuoles. Our results suggest that Rab5 mediates endocytosis that is essential for the maintenance of functionally critical nephrocyte plasma membrane structures and that Rabs 7 and 11 mediate alternative downstream vesicle trafficking pathways leading to protein degradation and membrane recycling, respectively. Elucidating molecular pathways underlying nephrocyte function has the potential to yield important insights into human kidney cell physiology and mechanisms of cell injury that lead to disease. The Drosophila nephrocyte is emerging as a useful in vivo model system for molecular target identification and initial testing of therapeutic approaches in humans.

The Aqueous Extract of Rhizome of Gastrodia elata Protected Drosophila and PC12 Cells against Beta-Amyloid-Induced Neurotoxicity

PubMed Central

Ng, Chun-Fai; Ko, Chun-Hay; Koon, Chi-Man; Xian, Jia-Wen; Leung, Ping-Chung; Fung, Kwok-Pui; Chan, Ho Yin Edwin; Lau, Clara Bik-San

2013-01-01

This study aims to investigate the neuroprotective effect of the rhizome of Gastrodia elata (GE) aqueous extract on beta-amyloid(Aβ)-induced toxicity in vivo and in vitro. Transgenic Drosophila mutants with Aβ-induced neurodegeneration in pan-neuron and ommatidia were used to determine the efficacy of GE. The antiapoptotic and antioxidative mechanisms of GE were also studied in Aβ-treated pheochromocytoma (PC12) cells. In vivo studies demonstrated that GE (5 mg/g Drosophila media)-treated Drosophila possessed a longer lifespan, better locomotor function, and less-degenerated ommatidia when compared with the Aβ-expressing control (all P < 0.05). In vitro studies illustrated that GE increased the cell viability of Aβ-treated PC12 cells in dose-dependent manner, probably through attenuation of Aβ-induced oxidative and apoptotic stress. GE also significantly upregulated the enzymatic activities of catalase, superoxide dismutase, and glutathione peroxidase, leading to the decrease of reactive oxidation species production and apoptotic marker caspase-3 activity. In conclusion, our current data presented the first evidence that the aqueous extract of GE was capable of reducing the Aβ-induced neurodegeneration in Drosophila, possibly through inhibition of apoptosis and reduction of oxidative stress. GE aqueous extract could be developed as a promising herbal agent for neuroprotection and novel adjuvant therapies for Alzheimer's disease. PMID:24174977

Cell death during Drosophila melanogaster early oogenesis is mediated through autophagy.

PubMed

Nezis, Ioannis P; Lamark, Trond; Velentzas, Athanassios D; Rusten, Tor Erik; Bjørkøy, Geir; Johansen, Terje; Papassideri, Issidora S; Stravopodis, Dimitrios J; Margaritis, Lukas H; Stenmark, Harald; Brech, Andreas

2009-04-01

Autophagy is a physiological and evolutionarily conserved process maintaining homeostatic functions, such as protein degradation and organelle turnover. Accumulating data provide evidence that autophagy also contributes to cell death under certain circumstances, but how this is achieved is not well known. Herein, we report that autophagy occurs during developmentally-induced cell death in the female germline, observed in the germarium and during middle developmental stages of oogenesis in Drosophila melanogaster. Degenerating germline cells exhibit caspase activation, chromatin condensation, DNA fragmentation and punctate staining of mCherry-DrAtg8a, a novel marker for monitoring autophagy in Drosophila. Genetic inhibition of autophagy, by removing atg1 or atg7 function, results in significant reduction of DNA fragmentation, suggesting that autophagy acts genetically upstream of DNA fragmentation in this tissue. This study provides new insights into the mechanisms that regulate cell death in vivo during development.

Pak functions downstream of Dock to regulate photoreceptor axon guidance in Drosophila.

PubMed

Hing, H; Xiao, J; Harden, N; Lim, L; Zipursky, S L

1999-06-25

The SH2/SH3 adaptor protein Dock has been proposed to transduce signals from guidance receptors to the actin cytoskeleton in Drosophila photoreceptor (R cell) growth cones. Here, we demonstrate that Drosophila p21-activated kinase (Pak) is required in a Dock pathway regulating R cell axon guidance and targeting. Dock and Pak colocalize to R cell axons and growth cones, physically interact, and their loss-of-function phenotypes are indistinguishable. Normal patterns of R cell connectivity require Pak's kinase activity and binding sites for both Dock and Cdc42/Rac. A membrane-tethered form of Pak (Pak(myr) acts as a dominant gain-of-function protein. Retinal expression of Pak(myr) rescues the R cell connectivity phenotype in dock mutants. These data establish Pak as a critical regulator of axon guidance and a downstream effector of Dock in vivo.

The histone demethylase KDM1A is essential for the maintenance and differentiation of spermatogonial stem cells and progenitors.

PubMed

Lambrot, Romain; Lafleur, Christine; Kimmins, Sarah

2015-11-01

Little is known of the fundamental processes governed by epigenetic mechanisms in the supplier cells of spermatogenesis, the spermatogonial stem cells (SSCs). The histone H3 lysine demethylase KDM1A is expressed in spermatogonia. We hypothesized that KDM1A serves in transcriptional regulation of SSCs and fertility. Using a conditional deletion of Kdm1a [conditional knockout (cKO)] in mouse spermatogonia, we determined that Kdm1a is essential for spermatogenesis as adult cKO males completely lack germ cells. Analysis of postnatal testis development revealed that undifferentiated and differentiating spermatogonial populations form in Kdm1a-cKO animals, yet the majority fail to enter meiosis. Loss of germ cells in the cKO was rapid with none remaining by postnatal day (PND) 21. To gain insight into the mechanistic implications of Kdm1a ablation, we isolated PND 6 spermatogonia enriched for SSCs and analyzed their transcriptome by RNA sequencing. Loss of Kdm1a was associated with altered transcription of 1206 genes. Importantly, differentially expressed genes between control and Kdm1a-cKO animals included those that are essential for SSC and progenitor maintenance and spermatogonial differentiation. The complete loss of fertility and failure to establish spermatogenesis indicate that Kdm1a is a master controller of gene transcription in spermatogonia and is required for SSC and progenitor maintenance and differentiation. © FASEB.

Use of Drosophila S2 Cells as a Model for Studying Ehrlichia chaffeensis Infections▿

PubMed Central

Luce-Fedrow, Alison; Von Ohlen, Tonia; Boyle, Daniel; Ganta, Roman R.; Chapes, Stephen K.

2008-01-01

Ehrlichia chaffeensis is an obligate intracellular bacterium and the causative agent of human monocytic ehrlichiosis. Although this pathogen grows in several mammalian cell lines, no general model for eukaryotic cellular requirements for bacteria replication has yet been proposed. We found that Drosophila S2 cells are permissive for the growth of E. chaffeensis. We saw morulae (aggregates of bacteria) by microscopy, detected the E. chaffeensis 16S rRNA gene by reverse transcriptase PCR, and used immunocytochemistry to detect E. chaffeensis in S2 and mammalian cells. Bacteria grown in S2 cells reinfected mammalian macrophages. S2 cells were made nonpermissive for E. chaffeensis through incubation with lipopolysaccharide. Our results demonstrate that S2 cells are an appropriate system for studying the pathogenesis of E. chaffeensis. The use of a Drosophila system has the potential to serve as a model system for studying Ehrlichia due to its completed genome, ease of genetic manipulation, and the availability of mutants. PMID:18245255

Production Methods for a Mesenchymal Stem Cell Therapeutic as a Medical Defense Countermeasure

DTIC Science & Technology

2012-02-01

differentiation of murine embryonic stem cells into vascular progenitors. BMC Cell Biol. 2008;9:2. 56. Johnson EA, Dao TL, Kan RK. Status epilepticus ...their undifferentiated and multipotent status . BMC Cell Biol. 2011;12:12. 52. Sun Y, Chen L, Hou XG, Hou WK, Dong JJ, Sun L, et al. Differentiation of

Selection and dynamics of embryonic stem cell integration into early mouse embryos

PubMed Central

Alexandrova, Stoyana; Kalkan, Tuzer; Humphreys, Peter; Riddell, Andrew; Scognamiglio, Roberta; Trumpp, Andreas; Nichols, Jennifer

2016-01-01

The process by which pluripotent cells incorporate into host embryos is of interest to investigate cell potency and cell fate decisions. Previous studies suggest that only a minority of the embryonic stem cell (ESC) inoculum contributes to the adult chimaera. How incoming cells are chosen for integration or elimination remains unclear. By comparing a heterogeneous mix of undifferentiated and differentiating ESCs (serum/LIF) with more homogeneous undifferentiated culture (2i/LIF), we examine the role of cellular heterogeneity in this process. Time-lapse ex vivo imaging revealed a drastic elimination of serum/LIF ESCs during early development in comparison with 2i/LIF ESCs. Using a fluorescent reporter for naive pluripotency (Rex1-GFP), we established that the acutely eliminated serum/LIF ESCs had started to differentiate. The rejected cells were apparently killed by apoptosis. We conclude that a selection process exists by which unwanted differentiating cells are eliminated from the embryo. However, occasional Rex1− cells were able to integrate. Upregulation of Rex1 occurred in a proportion of these cells, reflecting the potential of the embryonic environment to expedite diversion from differentiation priming to enhance the developing embryonic epiblast. PMID:26586221

Novel Approaches to Breast Cancer Prevention and Inhibition of Metastases

DTIC Science & Technology

2014-10-01

functional characterization of candidate breast cancer genes. The transgenic RNAi library is covering the whole Drosophila genome , giving us an...cancer prevention trials in BRCA1 carriers using RANKL blockade. Using Drosophila modeling of Ras-driven transformation, we performed a near- genome ... Genome wide functional genetics, haploid stem cells, Drosophila cancer modeling, breast cancer prevention, BRCA1 carriers 16. SECURITY

Pickle Flavors Relish in Drosophila Immunity.

PubMed

Salminen, Tiina Susanna; Rämet, Mika

2016-09-14

Immune responses must be tightly controlled to avoid host damage. In Drosophila, two NF-κB signaling pathways, Toll and Imd, mediate host immune responses. In this issue of Cell Host & Microbe, Morris et al. (2016) introduce Pickle, a nuclear IκB that inhibits Drosophila immune signaling by modulating the NF-κB Relish. Copyright © 2016 Elsevier Inc. All rights reserved.

Quiescent gastric stem cells maintain the adult Drosophila stomach.

PubMed

Strand, Marie; Micchelli, Craig A

2011-10-25

The adult Drosophila copper cell region or "stomach" is a highly acidic compartment of the midgut with pH < 3. In this region, a specialized group of acid-secreting cells similar to mammalian gastric parietal cells has been identified by a unique ultrastructure and by copper-metallothionein fluorescence. However, the homeostatic mechanism maintaining the acid-secreting "copper cells" of the adult midgut has not been examined. Here, we combine cell lineage tracing and genetic analysis to investigate the mechanism by which the gastric epithelium is maintained. Our investigation shows that a molecularly identifiable population of multipotent, self-renewing gastric stem cells (GSSCs) produces the acid-secreting copper cells, interstitial cells, and enteroendocrine cells of the stomach. Our assays demonstrate that GSSCs are largely quiescent but can be induced to regenerate the gastric epithelium in response to environmental challenge. Finally, genetic analysis reveals that adult GSSC maintenance depends on Wnt signaling. Characterization of the GSSC lineage in Drosophila, with striking similarities to mammals, will advance the study of both homeostatic and pathogenic processes in the stomach.

Insulin Stimulates Translocation of Human GLUT4 to the Membrane in Fat Bodies of Transgenic Drosophila melanogaster

PubMed Central

Crivat, Georgeta; Lizunov, Vladimir A.; Li, Caroline R.; Stenkula, Karin G.; Zimmerberg, Joshua; Cushman, Samuel W.; Pick, Leslie

2013-01-01

The fruit fly Drosophila melanogaster is an excellent model system for studies of genes controlling development and disease. However, its applicability to physiological systems is less clear because of metabolic differences between insects and mammals. Insulin signaling has been studied in mammals because of relevance to diabetes and other diseases but there are many parallels between mammalian and insect pathways. For example, deletion of Drosophila Insulin-Like Peptides resulted in ‘diabetic’ flies with elevated circulating sugar levels. Whether this situation reflects failure of sugar uptake into peripheral tissues as seen in mammals is unclear and depends upon whether flies harbor the machinery to mount mammalian-like insulin-dependent sugar uptake responses. Here we asked whether Drosophila fat cells are competent to respond to insulin with mammalian-like regulated trafficking of sugar transporters. Transgenic Drosophila expressing human glucose transporter-4 (GLUT4), the sugar transporter expressed primarily in insulin-responsive tissues, were generated. After expression in fat bodies, GLUT4 intracellular trafficking and localization were monitored by confocal and total internal reflection fluorescence microscopy (TIRFM). We found that fat body cells responded to insulin with increased GLUT4 trafficking and translocation to the plasma membrane. While the amplitude of these responses was relatively weak in animals reared on a standard diet, it was greatly enhanced in animals reared on sugar-restricted diets, suggesting that flies fed standard diets are insulin resistant. Our findings demonstrate that flies are competent to mobilize translocation of sugar transporters to the cell surface in response to insulin. They suggest that Drosophila fat cells are primed for a response to insulin and that these pathways are down-regulated when animals are exposed to constant, high levels of sugar. Finally, these studies are the first to use TIRFM to monitor insulin-signaling pathways in Drosophila, demonstrating the utility of TIRFM of tagged sugar transporters to monitor signaling pathways in insects. PMID:24223128

CD4+ acute undifferentiated leukaemia, probably early monoblastic type, developing in a patient with myelodysplastic syndrome and bone marrow fibrosis.

PubMed

Guenova, M; Taskov, H; Zechev, J

1997-07-01

We report here a patient who presented with pancytopenia, hypercellular bone marrow and three-lineage dysplasia associated with an increase of reticulin fibres. After a 5-month period, anaemia and thrombocytopenia progressed very rapidly and the white blood count increased showing 45% blasts with monocytoid morphology, but cytochemically undifferentiated in nature. The immunophenotype revealed an unusual expression of CD4, CD36 and HLA-DR in the absence of any other myeloid or lymphoid lineage-associated markers. The patient died unexpectedly during the course of chemotherapy. The occurrence of CD4, CD36 and HLA-DR on the blast cells cannot determine the lineage of differentiation with certainty but provides some evidence that the leukaemic cells were probably derived from a very early monocytic progenitor with maturation arrest. These cells had apparently complex interactions with pathologic megakaryocytes and cytokine production.

ARC-2006-ACD06-0091-020

NASA Image and Video Library

2006-06-05

Space shuttle STS-121 FIT (Fly Immunity and Tumors) payload. Using Drosophila (fruit fly) to complete the experiments. Computer screen showing green fluorescent protein used to visualize blood cells in Drosophila (fruit fly).

Modeling the complex pathology of Alzheimer’s disease in Drosophila

PubMed Central

Fernandez-Funez, Pedro; de Mena, Lorena; Rincon-Limas, Diego E.

2015-01-01

Alzheimer’s disease (AD) is the leading cause of dementia and the most common neurodegenerative disorder. AD is mostly a sporadic disorder and its main risk factor is age, but mutations in three genes that promote the accumulation of the amyloid-β (Aβ42) peptide revealed the critical role of Amyloid precursor protein (APP) processing in AD. Neurofibrillary tangles enriched in tau are the other pathological hallmark of AD, but the lack of causative tau mutations still puzzles researchers. Here, we describe the contribution of a powerful invertebrate model, the fruit fly Drosophila melanogaster, to uncovering the function and pathogenesis of human APP, Aβ42, and tau. APP and tau participate in many complex cellular processes, although their main function is microtubule stabilization and the to-and-fro transport of axonal vesicles. Additionally, expression of secreted Aβ42 induces prominent neuronal death in Drosophila, a critical feature of AD, making this model a popular choice for identifying intrinsic and extrinsic factors mediating Aβ42 neurotoxicity. Overall, Drosophila has made significant contributions to better understand the complex pathology of AD, although additional insight can be expected from combining multiple transgenes, performing genome-wide loss-of-function screens, and testing anti-tau therapies alone or in combination with Aβ42. PMID:26024860

Comparative population genomics of latitudinal variation in Drosophila simulans and Drosophila melanogaster

PubMed Central

MACHADO, HEATHER E.; BERGLAND, ALAN O.; O’BRIEN, KATHERINE R.; BEHRMAN, EMILY L.; SCHMIDT, PAUL S.; PETROV, DMITRI A.

2016-01-01

Examples of clinal variation in phenotypes and genotypes across latitudinal transects have served as important models for understanding how spatially varying selection and demographic forces shape variation within species. Here, we examine the selective and demographic contributions to latitudinal variation through the largest comparative genomic study to date of Drosophila simulans and Drosophila melanogaster, with genomic sequence data from 382 individual fruit flies, collected across a spatial transect of 19 degrees latitude and at multiple time points over 2 years. Consistent with phenotypic studies, we find less clinal variation in D. simulans than D. melanogaster, particularly for the autosomes. Moreover, we find that clinally varying loci in D. simulans are less stable over multiple years than comparable clines in D. melanogaster. D. simulans shows a significantly weaker pattern of isolation by distance than D. melanogaster and we find evidence for a stronger contribution of migration to D. simulans population genetic structure. While population bottlenecks and migration can plausibly explain the differences in stability of clinal variation between the two species, we also observe a significant enrichment of shared clinal genes, suggesting that the selective forces associated with climate are acting on the same genes and phenotypes in D. simulans and D. melanogaster. PMID:26523848

DNMT1 Maintains Progenitor Function in Self-Renewing Somatic Tissue

PubMed Central

Sen, George L.; Reuter, Jason A.; Webster, Daniel E.; Zhu, Lilly; Khavari, Paul A.

2010-01-01

Progenitor cells maintain self-renewing tissues throughout life by sustaining their capacity for proliferation while suppressing cell cycle exit and terminal differentiation1,2. DNA methylation3,4,5 provides a potential epigenetic mechanism for the cellular memory needed to preserve the somatic progenitor state through repeated cell divisions. DNA methyltransferase 1 (DNMT1)6,7 maintains DNA methylation patterns after cellular replication. Although dispensable for embryonic stem cell maintenance,8 a clear role for DNMT1 in maintaining the progenitor state in constantly replenished somatic tissues, such as mammalian epidermis, is unknown. Here we show that DNMT1 is essential for epidermal progenitor cell function. DNMT1 protein was found enriched in undifferentiated cells, where it was required to retain proliferative stamina and suppress differentiation. In tissue, DNMT1 depletion led to exit from the progenitor cell compartment, premature differentiation and eventual tissue loss. Genome-wide analysis revealed that a significant portion of epidermal differentiation gene promoters were methylated in self-renewing conditions but were subsequently demethylated during differentiation. Furthermore, we show that UHRF1,9,10 a component of the DNA methylation machinery that targets DNMT1 to hemi-methylated DNA, is also necessary to suppress premature differentiation and sustain proliferation. In contrast, Gadd45A11,12 and B13, which promote active DNA demethylation, are required for full epidermal differentiation gene induction. These data demonstrate that proteins involved in the dynamic regulation of DNA methylation patterns are required for progenitor maintenance and self-renewal in mammalian somatic tissue. PMID:20081831

In situ electrochemical detection of embryonic stem cell differentiation.

PubMed

Yea, Cheol-Heon; An, Jeung Hee; Kim, Jungho; Choi, Jeong-Woo

2013-06-20

Stem cell sensors have emerged as a promising technique to electrochemically monitor the functional status and viability of stem cells. However, efficient electrochemical analysis techniques are required for the development of effective electrochemical stem cell sensors. In the current study, we report a newly developed electrochemical cyclic voltammetry (CV) system to determine the status of mouse embryonic stem (ES) cells. 1-Naphthly phosphate (1-NP), which was dephosphorylated by alkaline phosphatase into a 1-naphthol on an undifferentiated mouse ES cell, was used as a substrate to electrochemically monitor the differentiation status of mouse ES cells. The peak current in the cyclic voltammetry of 1-NP increased linearly with the concentration of pure 1-NP (R(2)=0.9623). On the other hand, the peak current in the electrochemical responses of 1-NP decreased as the number of undifferentiated ES cells increased. The increased dephosphorylation of 1-NP to 1-naphthol made a decreased electrochemical signal. Non-toxicity of 1-NP was confirmed. In conclusion, the proposed electrochemical analysis system can be applied to an electrical stem cell chip for diagnosis, drug detection and on-site monitoring. Copyright © 2013 Elsevier B.V. All rights reserved.

Epigenetic Telomere Protection by Drosophila DNA Damage Response Pathways

PubMed Central

Oikemus, Sarah R; Queiroz-Machado, Joana; Lai, KuanJu; McGinnis, Nadine; Sunkel, Claudio; Brodsky, Michael H

2006-01-01

Analysis of terminal deletion chromosomes indicates that a sequence-independent mechanism regulates protection of Drosophila telomeres. Mutations in Drosophila DNA damage response genes such as atm/tefu, mre11, or rad50 disrupt telomere protection and localization of the telomere-associated proteins HP1 and HOAP, suggesting that recognition of chromosome ends contributes to telomere protection. However, the partial telomere protection phenotype of these mutations limits the ability to test if they act in the epigenetic telomere protection mechanism. We examined the roles of the Drosophila atm and atr-atrip DNA damage response pathways and the nbs homolog in DNA damage responses and telomere protection. As in other organisms, the atm and atr-atrip pathways act in parallel to promote telomere protection. Cells lacking both pathways exhibit severe defects in telomere protection and fail to localize the protection protein HOAP to telomeres. Drosophila nbs is required for both atm- and atr-dependent DNA damage responses and acts in these pathways during DNA repair. The telomere fusion phenotype of nbs is consistent with defects in each of these activities. Cells defective in both the atm and atr pathways were used to examine if DNA damage response pathways regulate telomere protection without affecting telomere specific sequences. In these cells, chromosome fusion sites retain telomere-specific sequences, demonstrating that loss of these sequences is not responsible for loss of protection. Furthermore, terminally deleted chromosomes also fuse in these cells, directly implicating DNA damage response pathways in the epigenetic protection of telomeres. We propose that recognition of chromosome ends and recruitment of HP1 and HOAP by DNA damage response proteins is essential for the epigenetic protection of Drosophila telomeres. Given the conserved roles of DNA damage response proteins in telomere function, related mechanisms may act at the telomeres of other organisms. PMID:16710445

Epigenetic telomere protection by Drosophila DNA damage response pathways.

PubMed

Oikemus, Sarah R; Queiroz-Machado, Joana; Lai, KuanJu; McGinnis, Nadine; Sunkel, Claudio; Brodsky, Michael H

2006-05-01

Analysis of terminal deletion chromosomes indicates that a sequence-independent mechanism regulates protection of Drosophila telomeres. Mutations in Drosophila DNA damage response genes such as atm/tefu, mre11, or rad50 disrupt telomere protection and localization of the telomere-associated proteins HP1 and HOAP, suggesting that recognition of chromosome ends contributes to telomere protection. However, the partial telomere protection phenotype of these mutations limits the ability to test if they act in the epigenetic telomere protection mechanism. We examined the roles of the Drosophila atm and atr-atrip DNA damage response pathways and the nbs homolog in DNA damage responses and telomere protection. As in other organisms, the atm and atr-atrip pathways act in parallel to promote telomere protection. Cells lacking both pathways exhibit severe defects in telomere protection and fail to localize the protection protein HOAP to telomeres. Drosophila nbs is required for both atm- and atr-dependent DNA damage responses and acts in these pathways during DNA repair. The telomere fusion phenotype of nbs is consistent with defects in each of these activities. Cells defective in both the atm and atr pathways were used to examine if DNA damage response pathways regulate telomere protection without affecting telomere specific sequences. In these cells, chromosome fusion sites retain telomere-specific sequences, demonstrating that loss of these sequences is not responsible for loss of protection. Furthermore, terminally deleted chromosomes also fuse in these cells, directly implicating DNA damage response pathways in the epigenetic protection of telomeres. We propose that recognition of chromosome ends and recruitment of HP1 and HOAP by DNA damage response proteins is essential for the epigenetic protection of Drosophila telomeres. Given the conserved roles of DNA damage response proteins in telomere function, related mechanisms may act at the telomeres of other organisms.

Effects of age, sex, and genotype on high-sensitivity metabolomic profiles in the fruit fly, Drosophila melanogaster

PubMed Central

Hoffman, Jessica M; Soltow, Quinlyn A; Li, Shuzhao; Sidik, Alfire; Jones, Dean P; Promislow, Daniel E L

2014-01-01

Researchers have used whole-genome sequencing and gene expression profiling to identify genes associated with age, in the hope of understanding the underlying mechanisms of senescence. But there is a substantial gap from variation in gene sequences and expression levels to variation in age or life expectancy. In an attempt to bridge this gap, here we describe the effects of age, sex, genotype, and their interactions on high-sensitivity metabolomic profiles in the fruit fly, Drosophila melanogaster. Among the 6800 features analyzed, we found that over one-quarter of all metabolites were significantly associated with age, sex, genotype, or their interactions, and multivariate analysis shows that individual metabolomic profiles are highly predictive of these traits. Using a metabolomic equivalent of gene set enrichment analysis, we identified numerous metabolic pathways that were enriched among metabolites associated with age, sex, and genotype, including pathways involving sugar and glycerophospholipid metabolism, neurotransmitters, amino acids, and the carnitine shuttle. Our results suggest that high-sensitivity metabolomic studies have excellent potential not only to reveal mechanisms that lead to senescence, but also to help us understand differences in patterns of aging among genotypes and between males and females. PMID:24636523

Bovine papillomavirus type 4 L1 gene transfection in a Drosophila S2 cell expression system: absence of L1 protein expression

PubMed Central

Góes, Luiz Gustavo Bentim; de Freitas, Antonio Carlos; Ferraz, Oilita Pereira; Rieger, Tania Tassinari; dos Santos, José Ferreira; Pereira, Alexandre; Beçak, Willy; Lindsey, Charles J.; de Cassia Stocco, Rita

2008-01-01

The development of a bovine papillomavirus (BPV) vaccine is an outstanding challenge. BPV protein L1 gene transfection in the Drosophila melanogaster S2 cell expression system failed to produce L1 protein notwithstanding correct L1 gene insertion. Severe genetic inbalance in the host cell line, including cytogenetic alterations, may account for the lack of protein expression. PMID:24031166

RNAseq Analysis of the Drosophila Response to the Entomopathogenic Nematode Steinernema

PubMed Central

Yadav, Shruti; Daugherty, Sean; Shetty, Amol Carl; Eleftherianos, Ioannis

2017-01-01

Drosophila melanogaster is an outstanding model to study the molecular and functional basis of host–pathogen interactions. Currently, our knowledge of microbial infections in D. melanogaster is well understood; however, the response of flies to nematode infections is still in its infancy. Here, we have used the potent parasitic nematode Steinernema carpocapsae, which lives in mutualism with its endosymbiotic bacteria Xenorhabdus nematophila, to examine the transcriptomic basis of the interaction between D. melanogaster and entomopathogenic nematodes. We have employed next-generation RNA sequencing (RNAseq) to investigate the transcriptomic profile of D. melanogaster larvae in response to infection by S. carpocapsae symbiotic (carrying X. nematophila) or axenic (lacking X. nematophila) nematodes. Bioinformatic analyses have identified the strong induction of genes that are associated with the peritrophic membrane and the stress response, as well as several genes that participate in developmental processes. We have also found that genes with different biological functions are enriched in D. melanogaster larvae responding to either symbiotic or axenic nematodes. We further show that while symbiotic nematode infection enriched certain known immune-related genes, axenic nematode infection enriched several genes associated with chitin binding, lipid metabolic functions, and neuroactive ligand receptors. In addition, we have identified genes with a potential role in nematode recognition and genes with potential antinematode activity. Findings from this study will undoubtedly set the stage for the identification of key regulators of antinematode immune mechanisms in D. melanogaster, as well as in other insects of socioeconomic importance. PMID:28450373

RNAseq Analysis of the Drosophila Response to the Entomopathogenic Nematode Steinernema.

PubMed

Yadav, Shruti; Daugherty, Sean; Shetty, Amol Carl; Eleftherianos, Ioannis

2017-06-07

Drosophila melanogaster is an outstanding model to study the molecular and functional basis of host-pathogen interactions. Currently, our knowledge of microbial infections in D. melanogaster is well understood; however, the response of flies to nematode infections is still in its infancy. Here, we have used the potent parasitic nematode Steinernema carpocapsae , which lives in mutualism with its endosymbiotic bacteria Xenorhabdus nematophila , to examine the transcriptomic basis of the interaction between D. melanogaster and entomopathogenic nematodes. We have employed next-generation RNA sequencing (RNAseq) to investigate the transcriptomic profile of D. melanogaster larvae in response to infection by S. carpocapsae symbiotic (carrying X. nematophila ) or axenic (lacking X. nematophila ) nematodes. Bioinformatic analyses have identified the strong induction of genes that are associated with the peritrophic membrane and the stress response, as well as several genes that participate in developmental processes. We have also found that genes with different biological functions are enriched in D. melanogaster larvae responding to either symbiotic or axenic nematodes. We further show that while symbiotic nematode infection enriched certain known immune-related genes, axenic nematode infection enriched several genes associated with chitin binding, lipid metabolic functions, and neuroactive ligand receptors. In addition, we have identified genes with a potential role in nematode recognition and genes with potential antinematode activity. Findings from this study will undoubtedly set the stage for the identification of key regulators of antinematode immune mechanisms in D. melanogaster , as well as in other insects of socioeconomic importance. Copyright © 2017 Yadav et al.

Transport of polyamines in Drosophila S2 cells: kinetics, pharmacology and dependence on the plasma membrane proton gradient

PubMed Central

Romero-Calderón, Rafael; Krantz, David E.

2005-01-01

Polyamine transport activities have been described in diverse multicellular systems, but their bioenergetic mechanisms and molecular identity remain unclear. In the present paper, we describe a high-affinity spermine/spermidine transport activity expressed in Drosophila S2 cells. Ion-replacement experiments indicate that polyamine uptake across the cell membrane is Na+-, K+-, Cl−- and Ca2+-independent, but pH-sensitive. Additional experiments using ionophores suggest that polyamine uptake may be H+-coupled. Pharmacological experiments show that polyamine uptake in S2 cells is selectively blocked by MGBG {methylglyoxal bis(guanylhydrazone) or 1,1′-[(methylethanediylidine)-dinitrilo]diguanidine} and paraquat (N,N-dimethyl-4,4′-bipyridylium), two known inhibitors of polyamine uptake in mammalian cells. In addition, inhibitors known to block the Slc22 (solute carrier 22) family of organic anion/cation transporters inhibit spermine uptake in S2 cells. These data and the genetic tools available in Drosophila will facilitate the molecular identification and further characterization of this activity. PMID:16248856

Transport of polyamines in Drosophila S2 cells: kinetics, pharmacology and dependence on the plasma membrane proton gradient.

PubMed

Romero-Calderón, Rafael; Krantz, David E

2006-01-15

Polyamine transport activities have been described in diverse multicellular systems, but their bioenergetic mechanisms and molecular identity remain unclear. In the present paper, we describe a high-affinity spermine/spermidine transport activity expressed in Drosophila S2 cells. Ion-replacement experiments indicate that polyamine uptake across the cell membrane is Na+-, K+-, Cl-- and Ca2+-independent, but pH-sensitive. Additional experiments using ionophores suggest that polyamine uptake may be H+-coupled. Pharmacological experiments show that polyamine uptake in S2 cells is selectively blocked by MGBG {methylglyoxal bis(guanylhydrazone) or 1,1'-[(methylethanediylidine)-dinitrilo]diguanidine} and paraquat (N,N-dimethyl-4,4'-bipyridylium), two known inhibitors of polyamine uptake in mammalian cells. In addition, inhibitors known to block the Slc22 (solute carrier 22) family of organic anion/cation transporters inhibit spermine uptake in S2 cells. These data and the genetic tools available in Drosophila will facilitate the molecular identification and further characterization of this activity.

Serpin Facilitates Tumor-Suppressive Cell Competition by Blocking Toll-Mediated Yki Activation in Drosophila.

PubMed

Katsukawa, Mitsuko; Ohsawa, Shizue; Zhang, Lina; Yan, Yan; Igaki, Tatsushi

2018-06-04

Normal epithelial tissue exerts an intrinsic tumor-suppressive effect against oncogenically transformed cells. In Drosophila imaginal epithelium, clones of oncogenic polarity-deficient cells mutant for scribble (scrib) or discs large (dlg) are eliminated by cell competition when surrounded by wild-type cells. Here, through a genetic screen in Drosophila, we identify Serpin5 (Spn5), a secreted negative regulator of Toll signaling, as a crucial factor for epithelial cells to eliminate scrib mutant clones from epithelium. Downregulation of Spn5 in wild-type cells leads to elevation of Toll signaling in neighboring scrib cells. Strikingly, forced activation of Toll signaling or Toll-related receptor (TRR) signaling in scrib clones transforms scrib cells from losers to supercompetitors, resulting in tumorous overgrowth of mutant clones. Mechanistically, Toll activation in scrib clones leads to c-Jun N-terminal kinase (JNK) activation and F-actin accumulation, which cause strong activation of the Hippo pathway effector Yorkie that blocks cell death and promotes cell proliferation. Our data suggest that Spn5 secreted from normal epithelial cells acts as a component of the extracellular surveillance system that facilitates elimination of pre-malignant cells from epithelium. Copyright © 2018 Elsevier Ltd. All rights reserved.

Apoptotic activity and gene responses in Drosophila melanogaster S2 cells, induced by azadirachtin A.

PubMed

Xu, Lin; Li, Sheng; Ran, Xueqin; Liu, Chang; Lin, Rutao; Wang, Jiafu

2016-09-01

Azadirachtin has been used as an antifeedant and growth disruption agent for many insect species. Previous investigations have reported the apoptotic effects of azadirachtin on some insect cells, but the molecular mechanisms are still not clear. This study investigated the underlying molecular mechanisms for the apoptotic effects induced by azadirachtin on Drosophila melanogaster S2 cells in vitro. The results of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay demonstrated that azadirachtin exhibited significant cytotoxicity to S2 cells in a time- and dose-dependent manner. The changes in cellular morphology and the DNA fragmentation demonstrated that azadirachtin induced remarkable apoptosis of S2 cells. Expression levels of 276 genes were found to be significantly changed in S2 cells after exposure to azadirachtin, as detected by Drosophila genome array. Among these genes, calmodulin (CaM) was the most highly upregulated gene. Azadirachtin was further demonstrated to trigger intracellular Ca(2+) release in S2 cells. The genes related to the apoptosis pathway, determined from chip data, were validated by the real-time quantitative polymerase chain reaction method. The results showed that azadirachtin-mediated intracellular Ca(2+) release was the primary event that triggered apoptosis in Drosophila S2 cells through both pathways of the Ca(2+) -CaM and EcR/Usp signalling cascade. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Imaging the Drosophila retina: zwitterionic buffers PIPES and HEPES induce morphological artifacts in tissue fixation.

PubMed

Nie, Jing; Mahato, Simpla; Zelhof, Andrew C

2015-02-03

Tissue fixation is crucial for preserving the morphology of biological structures and cytological details to prevent postmortem degradation and autolysis. Improper fixation conditions could lead to artifacts and thus incorrect conclusions in immunofluorescence or histology experiments. To resolve reported structural anomalies with respect to Drosophila photoreceptor cell organization we developed and utilized a combination of live imaging and fixed samples to investigate the exact biogenesis and to identify the underlying source for the reported discrepancies in structure. We found that piperazine-N,N'-bis(ethanesulfonic acid) (PIPES) and 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), two zwitterionic buffers commonly used in tissue fixation, can cause severe lumen and cell morphological defects in Drosophila pupal and adult retina; the inter-rhabdomeral lumen becomes dilated and the photoreceptor cells are significantly reduced in size. Correspondingly, the localization pattern of Eyes shut (EYS), a luminal protein, is severely altered. In contrast, tissues fixed in the phosphate buffered saline (PBS) buffer results in lumen and cell morphologies that are consistent with live imaging. We suggest that PIPES and HEPES buffers should be utilized with caution for fixation when examining the interplay between cells and their extracellular environment, especially in Drosophila pupal and adult retina research.

Autophagy in Drosophila ovaries is induced by starvation and is required for oogenesis.

PubMed

Barth, J M I; Szabad, J; Hafen, E; Köhler, K

2011-06-01

Autophagy, an evolutionarily conserved lysosome-mediated degradation, promotes cell survival under starvation and is controlled by insulin/target of rapamycin (TOR) signaling. In Drosophila, nutrient depletion induces autophagy in the fat body. Interestingly, nutrient availability and insulin/TOR signaling also influence the size and structure of Drosophila ovaries, however, the role of nutrient signaling and autophagy during this process remains to be elucidated. Here, we show that starvation induces autophagy in germline cells (GCs) and in follicle cells (FCs) in Drosophila ovaries. This process is mediated by the ATG machinery and involves the upregulation of Atg genes. We further demonstrate that insulin/TOR signaling controls autophagy in FCs and GCs. The analysis of chimeric females reveals that autophagy in FCs, but not in GCs, is required for egg development. Strikingly, when animals lack Atg gene function in both cell types, ovaries develop normally, suggesting that the incompatibility between autophagy-competent GCs and autophagy-deficient FCs leads to defective egg development. As egg morphogenesis depends on a tightly linked signaling between FCs and GCs, we propose a model in which autophagy is required for the communication between these two cell types. Our data establish an important function for autophagy during oogenesis and contributes to the understanding of the role of autophagy in animal development.

Role of JAK/STAT signaling in neuroepithelial stem cell maintenance and proliferation in the Drosophila optic lobe

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

Wang, Wei; Li, Yonggang; Zhou, Liya

2011-07-15

Highlights: {yields} JAK/STAT activity is graded in the Drosophila optic lobe neuroepithelium. {yields} Inactivation of JAK signaling causes disintegration of the optic lobe neuroepithelium and depletion of the neuroepithelial stem cells. {yields} JAK pathway overactivation promotes neuroepithelial overgrowth. {yields} Notch signaling acts downstream of JAK/STAT to promote neuroepithelial growth and expansion. -- Abstract: During Drosophila optic lobe development, proliferation and differentiation must be tightly modulated to reach its normal size for proper functioning. The JAK/STAT pathway plays pleiotropic roles in Drosophila development and in the larval brain, has been shown to inhibit medulla neuroblast formation. In this study, we findmore » that JAK/STAT activity is required for the maintenance and proliferation of the neuroepithelial stem cells in the optic lobe. In loss-of-function JAK/STAT mutant brains, the neuroepithelial cells lose epithelial cell characters and differentiate prematurely while ectopic activation of this pathway is sufficient to induce neuroepithelial overgrowth in the optic lobe. We further show that Notch signaling acts downstream of JAK/STAT to control the maintenance and growth of the optic lobe neuroepithelium. Thus, in addition to its role in suppression of neuroblast formation, the JAK/STAT pathway is necessary and sufficient for optic lobe neuroepithelial growth.« less

Factors Influencing the Production of MFSV Full-Length Clone: Maize Fine Streak Virus Proteins in Drosophila S2 Cells

USDA-ARS?s Scientific Manuscript database

Maize fine streak virus (MFSV) is negative-sense RNA virus member of the genus Nucleorhabdovirus. Our goal is to determine whether Drosophila S2 cells can support the production of a full-length clone of MFSV. We have previously demonstrated that the full-length MFSV nucleoprotein (N) and phosphopro...

Repression of mammosphere formation of human breast cancer cells by soy isoflavone genistein and blueberry polyphenolic acids suggests diet-mediated targeting of cancer stem-like/progenitor cells

USDA-ARS?s Scientific Manuscript database

Mammary stem cells are undifferentiated epithelial cells which initiate mammary tumors and render them resistant to anticancer therapies, when deregulated. Diets rich in fruits and vegetables are implicated in breast cancer risk reduction, yet underlying mechanisms are poorly understood. Here, we ad...

Phenotypic Plasticity and Cell Fate Decisions in Cancer: Insights from Dynamical Systems Theory.

PubMed

Jia, Dongya; Jolly, Mohit Kumar; Kulkarni, Prakash; Levine, Herbert

2017-06-22

Waddington's epigenetic landscape, a famous metaphor in developmental biology, depicts how a stem cell progresses from an undifferentiated phenotype to a differentiated one. The concept of "landscape" in the context of dynamical systems theory represents a high-dimensional space, in which each cell phenotype is considered as an "attractor" that is determined by interactions between multiple molecular players, and is buffered against environmental fluctuations. In addition, biological noise is thought to play an important role during these cell-fate decisions and in fact controls transitions between different phenotypes. Here, we discuss the phenotypic transitions in cancer from a dynamical systems perspective and invoke the concept of "cancer attractors"-hidden stable states of the underlying regulatory network that are not occupied by normal cells. Phenotypic transitions in cancer occur at varying levels depending on the context. Using epithelial-to-mesenchymal transition (EMT), cancer stem-like properties, metabolic reprogramming and the emergence of therapy resistance as examples, we illustrate how phenotypic plasticity in cancer cells enables them to acquire hybrid phenotypes (such as hybrid epithelial/mesenchymal and hybrid metabolic phenotypes) that tend to be more aggressive and notoriously resilient to therapies such as chemotherapy and androgen-deprivation therapy. Furthermore, we highlight multiple factors that may give rise to phenotypic plasticity in cancer cells, such as (a) multi-stability or oscillatory behaviors governed by underlying regulatory networks involved in cell-fate decisions in cancer cells, and (b) network rewiring due to conformational dynamics of intrinsically disordered proteins (IDPs) that are highly enriched in cancer cells. We conclude by discussing why a therapeutic approach that promotes "recanalization", i.e., the exit from "cancer attractors" and re-entry into "normal attractors", is more likely to succeed rather than a conventional approach that targets individual molecules/pathways.

Changes in the regulation of heat shock gene expression in neuronal cell differentiation.

PubMed

Oza, Jay; Yang, Jingxian; Chen, Kuang Yu; Liu, Alice Y-C

2008-01-01

Neuronal differentiation of the NG108-15 neuroblastoma-glioma hybrid cells is accompanied by a marked attenuation in the heat shock induction of the Hsp70-firefly luciferase reporter gene activity. Analysis of the amount and activation of heat shock factor 1, induction of mRNA(hsp), and the synthesis and accumulation of heat shock proteins (HSPs) in the undifferentiated and differentiated cells suggest a transcriptional mechanism for this attenuation. Concomitant with a decreased induction of the 72-kDa Hsp70 protein in the differentiated cells, there is an increased abundance of the constitutive 73-kDa Hsc70, a protein known to function in vesicle trafficking. Assessment of sensitivity of the undifferentiated and differentiated cells against stress-induced cell death reveals a significantly greater vulnerability of the differentiated cells toward the cytotoxic effects of arsenite and glutamate/glycine. This study shows that changes in regulation of the HSP and HSC proteins are components of the neuronal cell differentiation program and that the attenuated induction of HSPs likely contributes to neuronal vulnerability whereas the increased expression of Hsc70 likely has a role in neural-specific functions.

Autophagic degradation of dBruce controls DNA fragmentation in nurse cells during late Drosophila melanogaster oogenesis.

PubMed

Nezis, Ioannis P; Shravage, Bhupendra V; Sagona, Antonia P; Lamark, Trond; Bjørkøy, Geir; Johansen, Terje; Rusten, Tor Erik; Brech, Andreas; Baehrecke, Eric H; Stenmark, Harald

2010-08-23

Autophagy is an evolutionarily conserved pathway responsible for degradation of cytoplasmic material via the lysosome. Although autophagy has been reported to contribute to cell death, the underlying mechanisms remain largely unknown. In this study, we show that autophagy controls DNA fragmentation during late oogenesis in Drosophila melanogaster. Inhibition of autophagy by genetically removing the function of the autophagy genes atg1, atg13, and vps34 resulted in late stage egg chambers that contained persisting nurse cell nuclei without fragmented DNA and attenuation of caspase-3 cleavage. The Drosophila inhibitor of apoptosis (IAP) dBruce was found to colocalize with the autophagic marker GFP-Atg8a and accumulated in autophagy mutants. Nurse cells lacking Atg1 or Vps34 in addition to dBruce contained persisting nurse cell nuclei with fragmented DNA. This indicates that autophagic degradation of dBruce controls DNA fragmentation in nurse cells. Our results reveal autophagic degradation of an IAP as a novel mechanism of triggering cell death and thereby provide a mechanistic link between autophagy and cell death.

Improved process conditions for increasing expression of MHC class II protein from a stable Drosophila S2 cell line.

PubMed

Shen, Xiao; Dojcinovic, Danijel; Baldi, Lucia; Hacker, David L; Luescher, Immanuel F; Wurm, Florian M

2018-01-01

To investigate the effects of operational process conditions on expression of MHC class II protein from a stable Drosophila S2 cell line. When the Drosophila S2 cells were grown in vented orbitally shaken TubeSpin bioreactor 600 containers, cell growth was improved three-fold and the yield of recombinant major histocompatibility (MHC) class II protein (HLA-DR1 2xHis ) increased four-fold over the levels observed for the same cells cultivated in roller bottles (RB) without vented caps. Culturing in RB with vented caps while increasing the rotation speed from 6 rpm to 18 rpm also improved cell growth five-fold and protein productivity three-fold which is comparable to the levels observed in the orbitally shaken containers. Protein activity was found to be almost identical between the two vessel systems tested. Optimized cell culture conditions and a more efficient vessel type can enhance gas transfer and mixing and lead to substantial improvement of recombinant product yields from S2 cells.

Methods for the preparation of an autologous serum-free cultured epidermis and for autografting applications.

PubMed

Wille, John J; Burdge, Jeremy J; Park, Jong Y

2014-01-01

Cell culture techniques for producing a three-dimensional autologous epidermal autograft (cultured epidermal autograft) suitable for tissue grafting and wound healing procedures are described. This chapter commences with surgical biopsy of patient's skin tissue, further reduction of skin tissues to keratinocyte cells by enzymatic treatment, and recovery of viable adult keratinocytes in a new balanced buffered salt media supportive of the growth of clonally enriched isolated basal keratinocytes. Culture techniques required for the formation of a hole-free monolayer of undifferentiated basal keratinocytes without the use of an organotypic matrix substrate are accomplished with a specially designed nutrient basal media (HECK 109) that is a chemically defined and subsequent culture in this serum-free culture media supplemented with hormones and two human recombinant protein growth factors (EGF and IGF-1). Further culture techniques and media manipulations, including brief exposure to β-TGF to induce reversible G1-phase growth arrest, are followed by para-synchronous induction of a multilayered stratification and keratinizing epidermal differentiation, yielding a living three-dimensional epidermis formed entirely in cell culture. Protocols are listed for its enzymatic removal, floatation, and transfer for shipment to the clinic ready for surgical grafting to the self-same patient's debrided chronic leg ulcers. Recent clinical trial results have demonstrated the utility and efficacy of these grafts in forming durably healed chronic wounds.

Protein Equilibration through Somatic Ring Canals in Drosophila

PubMed Central

McLean, Peter F.; Cooley, Lynn

2013-01-01

Although intercellular bridges resulting from incomplete cytokinesis were discovered in somatic Drosophila tissues decades ago, the impact of these structures on intercellular communication and tissue biology is largely unknown. In this work, we demonstrate that the ~250 nm diameter somatic ring canals permit diffusion of cytoplasmic contents between connected cells and across mitotic clone boundaries, and enable the equilibration of protein between transcriptionally mosaic follicle cells in the Drosophila ovary. We obtained similar, though more restricted, results in the larval imaginal discs. Our work illustrates the lack of cytoplasmic autonomy in these tissues and suggests a role for somatic ring canals in promoting homogeneous protein expression within the tissue. PMID:23704373

Myeloid leukemia factor is a conserved regulator of RUNX transcription factor activity involved in hematopoiesis

PubMed Central

Bras, Stéphanie; Martin-Lannerée, Séverine; Gobert, Vanessa; Augé, Benoît; Breig, Osman; Sanial, Matthieu; Yamaguchi, Masamitsu; Haenlin, Marc; Plessis, Anne; Waltzer, Lucas

2012-01-01

Defining the function of the genes that, like RUNX1, are deregulated in blood cell malignancies represents an important challenge. Myeloid leukemia factors (MLFs) constitute a poorly characterized family of conserved proteins whose founding member, MLF1, has been associated with acute myeloid leukemia in humans. To gain insight into the functions of this family, we investigated the role of the Drosophila MLF homolog during blood cell development. Here we report that mlf controls the homeostasis of the Drosophila hematopoietic system. Notably, mlf participates in a positive feedback loop to fine tune the activity of the RUNX transcription factor Lozenge (LZ) during development of the crystal cells, one of the two main blood cell lineages in Drosophila. At the molecular level, our data in cell cultures and in vivo strongly suggest that MLF controls the number of crystal cells by protecting LZ from degradation. Remarkably, it appears that the human MLF1 protein can substitute for MLF in the crystal cell lineage. In addition, MLF stabilizes the human oncogenic fusion protein RUNX1-ETO and is required for RUNX1-ETO–induced blood cell disorders in a Drosophila model of leukemia. Finally, using the human leukemic blood cell line Kasumi-1, we show that MLF1 depletion impairs RUNX1-ETO accumulation and reduces RUNX1-ETO–dependent proliferation. Thus, we propose that the regulation of RUNX protein levels is a conserved feature of MLF family members that could be critical for normal and pathological blood cell development. PMID:22411814

ALTERATION OF CATECHOLAMINES IN PHOECHROMOCYTOMA (PC12) CELLS IN VITRO BY THE METABOLITES OF CHLOROTRIAZINE HERBICIDE

EPA Science Inventory

The effects of four major chlorotriazine metabolites on the constitutive synthesis of the catecholamines dopamine (DA) and norepinephrine (NE) were examined using undifferentiated PC12 cells. NE release and intracellular DA and NE concentrations were quantified following treatme...

Loss of Centrobin Enables Daughter Centrioles to Form Sensory Cilia in Drosophila.

PubMed

Gottardo, Marco; Pollarolo, Giulia; Llamazares, Salud; Reina, Jose; Riparbelli, Maria G; Callaini, Giuliano; Gonzalez, Cayetano

2015-08-31

Sensory cilia are organelles that convey information to the cell from the extracellular environment. In vertebrates, ciliary dysfunction results in ciliopathies that in humans comprise a wide spectrum of developmental disorders. In Drosophila, sensory cilia are found only in the neurons of type I sensory organs, but ciliary dysfunction also has dramatic consequences in this organism because it impairs the mechanosensory properties of bristles and chaetae and leads to uncoordination, a crippling condition that causes lethality shortly after eclosion. The cilium is defined by the ciliary membrane, a protrusion of the cell membrane that envelops the core structure known as the axoneme, a microtubule array that extends along the cilium from the basal body. In vertebrates, basal body function requires centriolar distal and subdistal appendages and satellites. Because these structures are acquired through centriole maturation, only mother centrioles can serve as basal bodies. Here, we show that although centriole maturity traits are lacking in Drosophila, basal body fate is reserved to mother centrioles in Drosophila type I neurons. Moreover, we show that depletion of the daughter-centriole-specific protein Centrobin (CNB) enables daughter centrioles to dock on the cell membrane and to template an ectopic axoneme that, although structurally defective, protrudes out of the cell and is enveloped by a ciliary membrane. Conversely, basal body capability is inhibited in mother centrioles modified to carry CNB. These results reveal the crucial role of CNB in regulating basal body function in Drosophila ciliated sensory organs. Copyright © 2015 Elsevier Ltd. All rights reserved.

The sex of specific neurons controls female body growth in Drosophila.

PubMed

Sawala, Annick; Gould, Alex P

2017-10-01

Sexual dimorphisms in body size are widespread throughout the animal kingdom but their underlying mechanisms are not well characterized. Most models for how sex chromosome genes specify size dimorphism have emphasized the importance of gonadal hormones and cell-autonomous influences in mammals versus strictly cell-autonomous mechanisms in Drosophila melanogaster. Here, we use tissue-specific genetics to investigate how sexual size dimorphism (SSD) is established in Drosophila. We find that the larger body size characteristic of Drosophila females is established very early in larval development via an increase in the growth rate per unit of body mass. We demonstrate that the female sex determination gene, Sex-lethal (Sxl), functions in central nervous system (CNS) neurons as part of a relay that specifies the early sex-specific growth trajectories of larval but not imaginal tissues. Neuronal Sxl acts additively in 2 neuronal subpopulations, one of which corresponds to 7 median neurosecretory cells: the insulin-producing cells (IPCs). Surprisingly, however, male-female differences in the production of insulin-like peptides (Ilps) from the IPCs do not appear to be involved in establishing SSD in early larvae, although they may play a later role. These findings support a relay model in which Sxl in neurons and Sxl in local tissues act together to specify the female-specific growth of the larval body. They also reveal that, even though the sex determination pathways in Drosophila and mammals are different, they both modulate body growth via a combination of tissue-autonomous and nonautonomous inputs.

Biomimetic Trehalose Biosensor Using Gustatory Receptor (Gr5a) Expressed in Drosophila Cells and Ion-Sensitive Field-Effect Transistor

NASA Astrophysics Data System (ADS)

Lau, Hui-Chong; Bae, Tae-Eon; Jang, Hyun-June; Kwon, Jae-Young; Cho, Won-Ju; Lim, Jeong-Ok

2013-04-01

The development of potential applications of biosensors using the sensory systems of vertebrates and invertebrates has progressed rapidly, especially in clinical diagnosis. The biosensor developed here involves the use of Drosophila cells expressing the gustatory receptor Gr5a and an ion-sensitive field-effect transistor (ISFET) sensor device. Gustatory receptor Gr5a is expressed abundantly in gustatory neurons and acts as a primary marker for tastants, especially sugar, in Drosophila. As a result, it could potentially serve as a good candidate for potential biomarkers of diseases in which the current knowledge of the cause and treatment is limited. The developed ISFET was based on the outstanding electrical characteristics of the metal-oxide-semiconductor field-effect transistor (MOSFET) with a subthreshold swing of 85 mV/dec, low leakage current of <10-12 and high on/off current ratio of 7.3×106. The SiO2 sensing membrane with a pH sensitivity of 34.9 mV/pH and drift rate 1.17 mV/h was sufficient for biosensing applications. In addition, the sensor device also showed significant compatibility with the Drosophila cells expressing Gr5a and their response to sugar, particularly trehalose. Moreover, the interactions between the transfected Drosophila cells and trehalose were consistent and reliable. This suggests that the developed ISFET sensor device could have potential use in the future as a screening device in diagnosis.

The sex of specific neurons controls female body growth in Drosophila

PubMed Central

Sawala, Annick

2017-01-01

Sexual dimorphisms in body size are widespread throughout the animal kingdom but their underlying mechanisms are not well characterized. Most models for how sex chromosome genes specify size dimorphism have emphasized the importance of gonadal hormones and cell-autonomous influences in mammals versus strictly cell-autonomous mechanisms in Drosophila melanogaster. Here, we use tissue-specific genetics to investigate how sexual size dimorphism (SSD) is established in Drosophila. We find that the larger body size characteristic of Drosophila females is established very early in larval development via an increase in the growth rate per unit of body mass. We demonstrate that the female sex determination gene, Sex-lethal (Sxl), functions in central nervous system (CNS) neurons as part of a relay that specifies the early sex-specific growth trajectories of larval but not imaginal tissues. Neuronal Sxl acts additively in 2 neuronal subpopulations, one of which corresponds to 7 median neurosecretory cells: the insulin-producing cells (IPCs). Surprisingly, however, male-female differences in the production of insulin-like peptides (Ilps) from the IPCs do not appear to be involved in establishing SSD in early larvae, although they may play a later role. These findings support a relay model in which Sxl in neurons and Sxl in local tissues act together to specify the female-specific growth of the larval body. They also reveal that, even though the sex determination pathways in Drosophila and mammals are different, they both modulate body growth via a combination of tissue-autonomous and nonautonomous inputs. PMID:28976974

A conserved role for L1 as a transmembrane link between neuronal adhesion and membrane cytoskeleton assembly.

PubMed

Hortsch, M; O'Shea, K S; Zhao, G; Kim, F; Vallejo, Y; Dubreuil, R R

1998-01-01

The L1-family of cell adhesion molecules is involved in many important aspects of nervous system development. Mutations in the human L1-CAM gene cause a complicated array of neurological phenotypes; however, the molecular basis of these effects cannot be explained by a simple loss of adhesive function. Human L1-CAM and its Drosophila homolog neuroglian are rather divergent in sequence, with the highest degree of amino acid sequence conservation between segments of their cytoplasmic domains. In an attempt to elucidate the fundamental functions shared between these distantly related members of the L1-family, we demonstrate here that the extracellular domains of mammalian L1-CAMs and Drosophila neuroglian are both able to induce the aggregation of transfected Drosophila S2 cells in vitro. To a limited degree they even interact with each other in cell adhesion and neurite outgrowth assays. The cytoplasmic domains of human L1-CAM and neuroglian are both able to interact with the Drosophila homolog of the cytoskeletal linker protein ankyrin. Moreover the recruitment of ankyrin to cell-cell contacts is completely dependent on L1-mediated cell adhesion. These findings support a model of L1 function in which the phenotypes of human L1-CAM mutations results from a disruption of the link between the extracellular environment and the neuronal cytoskeleton.

A sleep state in Drosophila larvae required for neural stem cell proliferation

PubMed Central

Szuperak, Milan; Churgin, Matthew A; Borja, Austin J; Raizen, David M; Fang-Yen, Christopher

2018-01-01

Sleep during development is involved in refining brain circuitry, but a role for sleep in the earliest periods of nervous system elaboration, when neurons are first being born, has not been explored. Here we identify a sleep state in Drosophila larvae that coincides with a major wave of neurogenesis. Mechanisms controlling larval sleep are partially distinct from adult sleep: octopamine, the Drosophila analog of mammalian norepinephrine, is the major arousal neuromodulator in larvae, but dopamine is not required. Using real-time behavioral monitoring in a closed-loop sleep deprivation system, we find that sleep loss in larvae impairs cell division of neural progenitors. This work establishes a system uniquely suited for studying sleep during nascent periods, and demonstrates that sleep in early life regulates neural stem cell proliferation. PMID:29424688

Design and characterization of hybrid peptide sol-gel materials for the solid state induction of neuronal differentiation

NASA Astrophysics Data System (ADS)

Jedlicka, Sabrina S.

2007-12-01

Cell-based therapeutics are a rapidly growing area of research, with considerable promise in the treatment of neurological diseases. One of the primary limitations to neuronal cell-based devices is the necessity to maintain cells in an immature or undifferentiated state in culture prior to transplantation. In many cases, the undifferentiated cell does not express the desired characteristics for implantation. Biologically functional nanomaterials provide the ability to manipulate the direct extracellular environment surrounding cells; influencing their fate and differentiation path. The ability to engineer the interface between the cells and culture materials provides a repeatable, stable means of directing cells down a specific growth path determined by endogenous signaling pathways. This materials approach to cellular engineering can limit the need for added exogenous growth factors, "feeder" layers, or animal sera, in addition to creating a homogenous cell population for transplantation. In this work, hybrid peptide ormosil materials were developed; designed to mimic the developing mammalian brain during corticogenesis. These materials have been developed to enhance the GABAergic phenotype of P19 embryonic carcinoma cells and immature immortalized neurons. The ability to develop a homogenous, directed cell population has implications in stem cell research, regenerative medicine, cell-based devices and biosensing technology.

Chemical Activation of the Hypoxia-Inducible Factor Reversibly Reduces Tendon Stem Cell Proliferation, Inhibits Their Differentiation, and Maintains Cell Undifferentiation

PubMed Central

Creo, Pasquale; Bergante, Sonia; Conforti, Erika; Banfi, Giuseppe

2018-01-01

Adult stem cell-based therapeutic approaches for tissue regeneration have been proposed for several years. However, adult stem cells are usually limited in number and difficult to be expanded in vitro, and they usually tend to quickly lose their potency with passages, as they differentiate and become senescent. Culturing stem cells under reduced oxygen tensions (below 21%) has been proposed as a tool to increase cell proliferation, but many studies reported opposite effects. In particular, cell response to hypoxia seems to be very stem cell type specific. Nonetheless, it is clear that a major role in this process is played by the hypoxia inducible factor (HIF), the master regulator of cell response to oxygen deprivation, which affects cell metabolism and differentiation. Herein, we report that a chemical activation of HIF in human tendon stem cells reduces their proliferation and inhibits their differentiation in a reversible and dose-dependent manner. These results support the notion that hypoxia, by activating HIF, plays a crucial role in preserving stem cells in an undifferentiated state in the “hypoxic niches” present in the tissue in which they reside before migrating in more oxygenated areas to heal a damaged tissue. PMID:29713352

Polyploidization and cell fusion contribute to wound healing in the adult Drosophila epithelium

PubMed Central

Losick, Vicki P.; Fox, Donald T.; Spradling, Allan C.

2014-01-01

Summary Background Re-establishing epithelial integrity and biosynthetic capacity is critically important following tissue damage. The adult Drosophila abdominal epithelium provides an attractive new system to address how post-mitotic diploid cells contribute to repair. Results Puncture wounds to the adult Drosophila epidermis close initially by forming a melanized scab. We found that epithelial cells near the wound site fuse to form a giant syncytium, which sends lamellae under the scab to re-epithelialize the damaged site. Other large cells arise more peripherally by initiating endocycles and becoming polyploid, or by cell fusion. Rac GTPase activity is needed for syncytium formation, while the Hippo signaling effector Yorkie modulates both polyploidization and cell fusion. Large cell formation is functionally important because when both polyploidization and fusion are blocked, wounds do not re-epithelialize. Conclusions Our observations indicate that cell mass lost upon wounding can be replaced by polyploidization instead of mitotic proliferation. We propose that large cells generated by polyploidization or cell fusion are essential because they are better able than diploid cells to mechanically stabilize wounds, especially those containing permanent acellular structures, such as scar tissue. PMID:24184101

Polyploidization and cell fusion contribute to wound healing in the adult Drosophila epithelium.

PubMed

Losick, Vicki P; Fox, Donald T; Spradling, Allan C

2013-11-18

Reestablishing epithelial integrity and biosynthetic capacity is critically important following tissue damage. The adult Drosophila abdominal epithelium provides an attractive new system to address how postmitotic diploid cells contribute to repair. Puncture wounds to the adult Drosophila epidermis close initially by forming a melanized scab. We found that epithelial cells near the wound site fuse to form a giant syncytium, which sends lamellae under the scab to re-epithelialize the damaged site. Other large cells arise more peripherally by initiating endocycles and becoming polyploid, or by cell fusion. Rac GTPase activity is needed for syncytium formation, while the Hippo signaling effector Yorkie modulates both polyploidization and cell fusion. Large cell formation is functionally important because when both polyploidization and fusion are blocked, wounds do not re-epithelialize. Our observations indicate that cell mass lost upon wounding can be replaced by polyploidization instead of mitotic proliferation. We propose that large cells generated by polyploidization or cell fusion are essential because they are better able than diploid cells to mechanically stabilize wounds, especially those containing permanent acellular structures, such as scar tissue. Copyright © 2013 Elsevier Ltd. All rights reserved.

Iron Absorption in Drosophila melanogaster

PubMed Central

Mandilaras, Konstantinos; Pathmanathan, Tharse; Missirlis, Fanis

2013-01-01

The way in which Drosophila melanogaster acquires iron from the diet remains poorly understood despite iron absorption being of vital significance for larval growth. To describe the process of organismal iron absorption, consideration needs to be given to cellular iron import, storage, export and how intestinal epithelial cells sense and respond to iron availability. Here we review studies on the Divalent Metal Transporter-1 homolog Malvolio (iron import), the recent discovery that Multicopper Oxidase-1 has ferroxidase activity (iron export) and the role of ferritin in the process of iron acquisition (iron storage). We also describe what is known about iron regulation in insect cells. We then draw upon knowledge from mammalian iron homeostasis to identify candidate genes in flies. Questions arise from the lack of conservation in Drosophila for key mammalian players, such as ferroportin, hepcidin and all the components of the hemochromatosis-related pathway. Drosophila and other insects also lack erythropoiesis. Thus, systemic iron regulation is likely to be conveyed by different signaling pathways and tissue requirements. The significance of regulating intestinal iron uptake is inferred from reports linking Drosophila developmental, immune, heat-shock and behavioral responses to iron sequestration. PMID:23686013

Kinetics of Doubletime Kinase-dependent Degradation of the Drosophila Period Protein*

PubMed Central

Syed, Sheyum; Saez, Lino; Young, Michael W.

2011-01-01

Robust circadian oscillations of the proteins PERIOD (PER) and TIMELESS (TIM) are hallmarks of a functional clock in the fruit fly Drosophila melanogaster. Early morning phosphorylation of PER by the kinase Doubletime (DBT) and subsequent PER turnover is an essential step in the functioning of the Drosophila circadian clock. Here using time-lapse fluorescence microscopy we study PER stability in the presence of DBT and its short, long, arrhythmic, and inactive mutants in S2 cells. We observe robust PER degradation in a DBT allele-specific manner. With the exception of doubletime-short (DBTS), all mutants produce differential PER degradation profiles that show direct correspondence with their respective Drosophila behavioral phenotypes. The kinetics of PER degradation with DBTS in cell culture resembles that with wild-type DBT and posits that, in flies DBTS likely does not modulate the clock by simply affecting PER degradation kinetics. For all the other tested DBT alleles, the study provides a simple model in which the changes in Drosophila behavioral rhythms can be explained solely by changes in the rate of PER degradation. PMID:21659538

Identification of functional elements and regulatory circuits by Drosophila modENCODE

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

Roy, Sushmita; Ernst, Jason; Kharchenko, Peter V.

2010-12-22

To gain insight into how genomic information is translated into cellular and developmental programs, the Drosophila model organism Encyclopedia of DNA Elements (modENCODE) project is comprehensively mapping transcripts, histone modifications, chromosomal proteins, transcription factors, replication proteins and intermediates, and nucleosome properties across a developmental time course and in multiple cell lines. We have generated more than 700 data sets and discovered protein-coding, noncoding, RNA regulatory, replication, and chromatin elements, more than tripling the annotated portion of the Drosophila genome. Correlated activity patterns of these elements reveal a functional regulatory network, which predicts putative new functions for genes, reveals stage- andmore » tissue-specific regulators, and enables gene-expression prediction. Our results provide a foundation for directed experimental and computational studies in Drosophila and related species and also a model for systematic data integration toward comprehensive genomic and functional annotation. Several years after the complete genetic sequencing of many species, it is still unclear how to translate genomic information into a functional map of cellular and developmental programs. The Encyclopedia of DNA Elements (ENCODE) (1) and model organism ENCODE (modENCODE) (2) projects use diverse genomic assays to comprehensively annotate the Homo sapiens (human), Drosophila melanogaster (fruit fly), and Caenorhabditis elegans (worm) genomes, through systematic generation and computational integration of functional genomic data sets. Previous genomic studies in flies have made seminal contributions to our understanding of basic biological mechanisms and genome functions, facilitated by genetic, experimental, computational, and manual annotation of the euchromatic and heterochromatic genome (3), small genome size, short life cycle, and a deep knowledge of development, gene function, and chromosome biology. The functions of {approx}40% of the protein and nonprotein-coding genes [FlyBase 5.12 (4)] have been determined from cDNA collections (5, 6), manual curation of gene models (7), gene mutations and comprehensive genome-wide RNA interference screens (8-10), and comparative genomic analyses (11, 12). The Drosophila modENCODE project has generated more than 700 data sets that profile transcripts, histone modifications and physical nucleosome properties, general and specific transcription factors (TFs), and replication programs in cell lines, isolated tissues, and whole organisms across several developmental stages (Fig. 1). Here, we computationally integrate these data sets and report (i) improved and additional genome annotations, including full-length proteincoding genes and peptides as short as 21 amino acids; (ii) noncoding transcripts, including 132 candidate structural RNAs and 1608 nonstructural transcripts; (iii) additional Argonaute (Ago)-associated small RNA genes and pathways, including new microRNAs (miRNAs) encoded within protein-coding exons and endogenous small interfering RNAs (siRNAs) from 3-inch untranslated regions; (iv) chromatin 'states' defined by combinatorial patterns of 18 chromatin marks that are associated with distinct functions and properties; (v) regions of high TF occupancy and replication activity with likely epigenetic regulation; (vi)mixed TF and miRNA regulatory networks with hierarchical structure and enriched feed-forward loops; (vii) coexpression- and co-regulation-based functional annotations for nearly 3000 genes; (viii) stage- and tissue-specific regulators; and (ix) predictive models of gene expression levels and regulator function.« less

Cell Surface Changes Associated with Cellular Immune Reactions in Drosophila

NASA Astrophysics Data System (ADS)

Nappi, Anthony J.; Silvers, Michael

1984-09-01

In Drosophila melanogaster a temperature-induced change in immune competence accompanies cell surface alterations that cause its blood cells to adhere and to encapsulate a parasite. At 29 degrees C the blood cells of the tumorous-lethal (Tuml) mutant show a high degree of immune competence and encapsulate the eggs of the parasitic wasp Leptopilina heterotoma. At 21 degrees C the blood cells are essentially immune incompetent. High percentages of lectin binding cells were found under conditions which potentiated cellular encapsulation responses. Some immune reactive blood cells did not bind lectin. The low percentages of lectin binding cells in susceptible hosts suggest that developing parasites alter the cell surface of the blood cells of immune reactive hosts.

An endogenous 55 kDa TNF receptor mediates cell death in a neural cell line.

PubMed

Sipe, K J; Srisawasdi, D; Dantzer, R; Kelley, K W; Weyhenmeyer, J A

1996-06-01

Tumor necrosis factor-alpha (TNF) is associated with developmental and injury-related events in the central nervous system (CNS). In the present study, we have examined the role of TNF on neurons using the clonal murine neuroblastoma line, N1E-115 (N1E). N1E cells represent a well-defined model for studying neuronal development since they can be maintained as either undifferentiated, mitotically active neuroblasts or as differentiated, mature neurons. Northern and reverse transcription-polymerase chain reaction (RT-PCR) analyses revealed that both undifferentiated and differentiated N1Es express transcripts for the 55 kDa TNF receptor (TNFR), but not the 75 kDa TNFR. The biological activity of the expressed TNF receptor was demonstrated by a dose dependent cytotoxicity to either recombinant murine or human TNF when the cells were incubated with the transcriptional inhibitor actinomycin D. The lack of the 75 kDa receptor mRNA expression and the dose dependent response to rHuTNF, an agonist specific for the murine 55 kDa receptor, suggest that the TNF induced cytotoxicity is mediated through the 55 kDa receptor in both the undifferentiated and differentiated N1Es. Light microscopic observations, flow cytometric analysis of hypodiploid DNA, and electrophoretic analysis of nucleosomal DNA fragmentation of N1Es treated with actinomycin D and TNF revealed features characteristic of both necrotic and apoptotic cell death. These findings demonstrate that blast and mature N1E cells express the 55 kDa TNF receptor which is responsible for inducing both necrotic and apoptotic death in these cells. The observation that actinomycin D renders N1E cells susceptible to the cytotoxic effects of TNF indicates that a sensitization step, such as removal of an endogenous protective factor or viral-mediated inhibition of transcription, may be necessary for TNF cytotoxicity in neurons.

Drosophila MOF regulates DIAP1 and induces apoptosis in a JNK dependent pathway.

PubMed

Pushpavalli, Sreerangam N C V L; Sarkar, Arpita; Ramaiah, M Janaki; Koteswara Rao, G; Bag, Indira; Bhadra, Utpal; Pal-Bhadra, Manika

2016-03-01

Histone modulations have been implicated in various cellular and developmental processes where in Drosophila Mof is involved in acetylation of H4K16. Reduction in the size of larval imaginal discs is observed in the null mutants of mof with increased apoptosis. Deficiency involving Hid, Reaper and Grim [H99] alleviated mof (RNAi) induced apoptosis in the eye discs. mof (RNAi) induced apoptosis leads to activation of caspases which is suppressed by over expression of caspase inhibitors like P35 and Diap1 clearly depicting the role of caspases in programmed cell death. Also apoptosis induced by knockdown of mof is rescued by JNK mutants of bsk and tak1 indicating the role of JNK in mof (RNAi) induced apoptosis. The adult eye ablation phenotype produced by ectopic expression of Hid, Rpr and Grim, was restored by over expression of Mof. Accumulation of Mof at the Diap1 promoter 800 bp upstream of the transcription start site in wild type larvae is significantly higher (up to twofolds) compared to mof (1) mutants. This enrichment coincides with modification of histone H4K16Ac indicating an induction of direct transcriptional up regulation of Diap1 by Mof. Based on these results we propose that apoptosis triggered by mof (RNAi) proceeds through a caspase-dependent and JNK mediated pathway.

Targeting the (Un)differentiated State of Cancer.

PubMed

Kemeny, Lajos V; Fisher, David E

2018-05-14

Dedifferentation in cancer is associated with intrinsic and acquired resistance to therapies. In this issue of Cancer Cell, Tsoi et al. identify four differentiation states in melanoma and provide evidence that melanoma cells develop drug resistance through a stepwise dedifferentiation process, making them vulnerable to ferroptotic cell death-inducing compounds. Copyright © 2018 Elsevier Inc. All rights reserved.

Laminin- and basement membrane-polycaprolactone blend nanofibers as a scaffold for regenerative medicine.

PubMed

Neal, Rebekah A; Lenz, Steven M; Wang, Tiffany; Abebayehu, Daniel; Brooks, Benjamin P C; Ogle, Roy C; Botchwey, Edward A

2014-09-01

Mimicking one or more components of the basement membrane (BM) holds great promise for overcoming insufficiencies in tissue engineering therapies. We have electrospun laminin nanofibers (NFs) isolated from the murine Engelbreth-Holm Swarm (EHS) tumor and evaluated them as a scaffold for embryonic stem cell culture. Seeded human embryonic stem cells were found to better maintain their undifferentiated, colony environment when cultured on laminin NFs compared to laminin mats, with 75% remaining undifferentiated on NFs. Mouse embryonic stem cells cultured on 10% laminin-polycaprolactone (PCL) NFs maintained their colony formation for twice as long without passage compared to those on PCL or gelatin substrates. In addition, we have established a protocol for electrospinning reconstituted basement membrane aligned (RBM)-PCL NFs within 10° of angular deviation. Neuron-like PC12 cells show significantly greater attachment (p < 0.001) and percentage of neurite-extending cells in vitro on 10% RBM-PCL NFs when compared to 1% and 0% RBM-PCL NFs (p < 0.015 and p < 0.001, respectively). Together, these results implicate laminin- and RBM-PCL scaffolds as a promising biomimetic substrate for regenerative medicine applications.

Zap70 functions to maintain stemness of mouse embryonic stem cells by negatively regulating Jak1/Stat3/c-Myc signaling

PubMed Central

Cha, Young; Moon, Bo-Hyun; Lee, Mi-Ok; Ahn, Hee-Jin; Lee, Hye-Jin; Lee, Kyung-Ah; Fornace, Albert J.; Kim, Kwang-Soo; Cha, Hyuk-Jin; Park, Kyung-Soon

2011-01-01

Zeta-chain associated protein kinase-70 (Zap70), a Syk family tyrosine kinase, has been reported to be present exclusively in normal T cells, Natural Killer (NK) cells, and B cells, serving as a pivotal regulator of antigen-mediated receptor signaling and development. In this study, we report that Zap70 is expressed in undifferentiated mouse embryonic stem cells (mESCs) and may critically regulate self-renewal and pluripotency in mESCs. We found that Zap70 knocked-down mESCs (Zap70KD) show sustained self-renewal and defective differentiation. In addition, we present evidence that the sustained self-renewal in Zap70KD is associated with enhanced Jak/Stat3 signaling and c-Myc induction. These altered signaling appears to result from up-regulated LIFR and down-regulated SHP-1 phosphatase activity. Based on these results, we propose that, in undifferentiated mESCs, Zap70 plays important roles in modulating the balance between self-renewal capacity and pluripotent differentiation ability as a key regulator of the Jak/Stat3/c-Myc signaling pathway. PMID:20641039

The Effects of Royal Jelly on Fitness Traits and Gene Expression in Drosophila melanogaster

PubMed Central

Shorter, John R.; Geisz, Matthew; Özsoy, Ergi; Magwire, Michael M.; Carbone, Mary Anna; Mackay, Trudy F. C.

2015-01-01

Royal Jelly (RJ) is a product made by honey bee workers and is required for queen differentiation and accompanying changes in queen body size, development time, lifespan and reproductive output relative to workers. Previous studies have reported similar changes in Drosophila melanogaster in response to RJ. Here, we quantified viability, development time, body size, productivity, lifespan and genome wide transcript abundance of D. melanogaster reared on standard culture medium supplemented with increasing concentrations of RJ. We found that lower concentrations of RJ do induce significant differences in body size in both sexes; higher concentrations reduce size, increase mortality, shorten lifespan and reduce productivity. Increased concentrations of RJ also consistently lengthened development time in both sexes. RJ is associated with changes in expression of 1,581 probe sets assessed using Affymetrix Drosophila 2.0 microarrays, which were enriched for genes associated with metabolism and amino acid degradation. The transcriptional changes are consistent with alterations in cellular processes to cope with excess nutrients provided by RJ, including biosynthesis and detoxification, which might contribute to accelerated senescence and reduced lifespan. PMID:26226016

Regulation of Drosophila Brain Wiring by Neuropil Interactions via a Slit-Robo-RPTP Signaling Complex.

PubMed

Oliva, Carlos; Soldano, Alessia; Mora, Natalia; De Geest, Natalie; Claeys, Annelies; Erfurth, Maria-Luise; Sierralta, Jimena; Ramaekers, Ariane; Dascenco, Dan; Ejsmont, Radoslaw K; Schmucker, Dietmar; Sanchez-Soriano, Natalia; Hassan, Bassem A

2016-10-24

The axonal wiring molecule Slit and its Round-About (Robo) receptors are conserved regulators of nerve cord patterning. Robo receptors also contribute to wiring brain circuits. Whether molecular mechanisms regulating these signals are modified to fit more complex brain wiring processes is unclear. We investigated the role of Slit and Robo receptors in wiring Drosophila higher-order brain circuits and identified differences in the cellular and molecular mechanisms of Robo/Slit function. First, we find that signaling by Robo receptors in the brain is regulated by the Receptor Protein Tyrosine Phosphatase RPTP69d. RPTP69d increases membrane availability of Robo3 without affecting its phosphorylation state. Second, we detect no midline localization of Slit during brain development. Instead, Slit is enriched in the mushroom body, a neuronal structure covering large areas of the brain. Thus, a divergent molecular mechanism regulates neuronal circuit wiring in the Drosophila brain, partly in response to signals from the mushroom body. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

In vitro antiproliferative/cytotoxic activity on cancer cell lines of a cardanol and a cardol enriched from Thai Apis mellifera propolis.

PubMed

Teerasripreecha, Dungporn; Phuwapraisirisan, Preecha; Puthong, Songchan; Kimura, Kiyoshi; Okuyama, Masayuki; Mori, Haruhide; Kimura, Atsuo; Chanchao, Chanpen

2012-03-30

Propolis is a complex resinous honeybee product. It is reported to display diverse bioactivities, such as antimicrobial, anti-inflammatory and anti-tumor properties, which are mainly due to phenolic compounds, and especially flavonoids. The diversity of bioactive compounds depends on the geography and climate, since these factors affect the floral diversity. Here, Apis mellifera propolis from Nan province, Thailand, was evaluated for potential anti-cancer activity. Propolis was sequentially extracted with methanol, dichloromethane and hexane and the cytotoxic activity of each crude extract was assayed for antiproliferative/cytotoxic activity in vitro against five human cell lines derived from duet carcinoma (BT474), undifferentiated lung (Chaco), liver hepatoblastoma (Hep-G(2)), gastric carcinoma (KATO-III) and colon adenocarcinoma (SW620) cancers. The human foreskin fibroblast cell line (Hs27) was used as a non-transformed control. Those crude extracts that displayed antiproliferative/cytotoxic activity were then further fractionated by column chromatography using TLC-pattern and MTT-cytotoxicity bioassay guided selection of the fractions. The chemical structure of each enriched bioactive compound was analyzed by nuclear magnetic resonance and mass spectroscopy. The crude hexane and dichloromethane extracts of propolis displayed antiproliferative/cytotoxic activities with IC(50) values across the five cancer cell lines ranging from 41.3 to 52.4 μg/ml and from 43.8 to 53.5 μg/ml, respectively. Two main bioactive components were isolated, one cardanol and one cardol, with broadly similar in vitro antiproliferation/cytotoxicity IC(50) values across the five cancer cell lines and the control Hs27 cell line, ranging from 10.8 to 29.3 μg/ml for the cardanol and < 3.13 to 5.97 μg/ml (6.82 - 13.0 μM) for the cardol. Moreover, both compounds induced cytotoxicity and cell death without DNA fragmentation in the cancer cells, but only an antiproliferation response in the control Hs27 cells However, these two compounds did not account for the net antiproliferation/cytotoxic activity of the crude extracts suggesting the existence of other potent compounds or synergistic interactions in the propolis extracts. This is the first report that Thai A. mellifera propolis contains at least two potentially new compounds (a cardanol and a cardol) with potential anti-cancer bioactivity. Both could be alternative antiproliferative agents for future development as anti-cancer drugs.

A Scalable System for Production of Functional Pancreatic Progenitors from Human Embryonic Stem Cells

PubMed Central

Schulz, Thomas C.; Young, Holly Y.; Agulnick, Alan D.; Babin, M. Josephine; Baetge, Emmanuel E.; Bang, Anne G.; Bhoumik, Anindita; Cepa, Igor; Cesario, Rosemary M.; Haakmeester, Carl; Kadoya, Kuniko; Kelly, Jonathan R.; Kerr, Justin; Martinson, Laura A.; McLean, Amanda B.; Moorman, Mark A.; Payne, Janice K.; Richardson, Mike; Ross, Kelly G.; Sherrer, Eric S.; Song, Xuehong; Wilson, Alistair Z.; Brandon, Eugene P.; Green, Chad E.; Kroon, Evert J.; Kelly, Olivia G.; D’Amour, Kevin A.; Robins, Allan J.

2012-01-01

Development of a human embryonic stem cell (hESC)-based therapy for type 1 diabetes will require the translation of proof-of-principle concepts into a scalable, controlled, and regulated cell manufacturing process. We have previously demonstrated that hESC can be directed to differentiate into pancreatic progenitors that mature into functional glucose-responsive, insulin-secreting cells in vivo. In this study we describe hESC expansion and banking methods and a suspension-based differentiation system, which together underpin an integrated scalable manufacturing process for producing pancreatic progenitors. This system has been optimized for the CyT49 cell line. Accordingly, qualified large-scale single-cell master and working cGMP cell banks of CyT49 have been generated to provide a virtually unlimited starting resource for manufacturing. Upon thaw from these banks, we expanded CyT49 for two weeks in an adherent culture format that achieves 50–100 fold expansion per week. Undifferentiated CyT49 were then aggregated into clusters in dynamic rotational suspension culture, followed by differentiation en masse for two weeks with a four-stage protocol. Numerous scaled differentiation runs generated reproducible and defined population compositions highly enriched for pancreatic cell lineages, as shown by examining mRNA expression at each stage of differentiation and flow cytometry of the final population. Islet-like tissue containing glucose-responsive, insulin-secreting cells was generated upon implantation into mice. By four- to five-months post-engraftment, mature neo-pancreatic tissue was sufficient to protect against streptozotocin (STZ)-induced hyperglycemia. In summary, we have developed a tractable manufacturing process for the generation of functional pancreatic progenitors from hESC on a scale amenable to clinical entry. PMID:22623968

Mesenchymal stem cell like (MSCl) cells generated from human embryonic stem cells support pluripotent cell growth

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

Varga, Nora; Vereb, Zoltan; Rajnavoelgyi, Eva

2011-10-28

Highlights: Black-Right-Pointing-Pointer MSC like cells were derived from hESC by a simple and reproducible method. Black-Right-Pointing-Pointer Differentiation and immunosuppressive features of MSCl cells were similar to bmMSC. Black-Right-Pointing-Pointer MSCl cells as feeder cells support the undifferentiated growth of hESC. -- Abstract: Mesenchymal stem cell like (MSCl) cells were generated from human embryonic stem cells (hESC) through embryoid body formation, and isolated by adherence to plastic surface. MSCl cell lines could be propagated without changes in morphological or functional characteristics for more than 15 passages. These cells, as well as their fluorescent protein expressing stable derivatives, efficiently supported the growth ofmore » undifferentiated human embryonic stem cells as feeder cells. The MSCl cells did not express the embryonic (Oct4, Nanog, ABCG2, PODXL, or SSEA4), or hematopoietic (CD34, CD45, CD14, CD133, HLA-DR) stem cell markers, while were positive for the characteristic cell surface markers of MSCs (CD44, CD73, CD90, CD105). MSCl cells could be differentiated toward osteogenic, chondrogenic or adipogenic directions and exhibited significant inhibition of mitogen-activated lymphocyte proliferation, and thus presented immunosuppressive features. We suggest that cultured MSCl cells can properly model human MSCs and be applied as efficient feeders in hESC cultures.« less

Drosophila Protein Kinase CK2: Genetics, Regulatory Complexity and Emerging Roles during Development

PubMed Central

Bandyopadhyay, Mohna; Arbet, Scott; Bishop, Clifton P.; Bidwai, Ashok P.

2016-01-01

CK2 is a Ser/Thr protein kinase that is highly conserved amongst all eukaryotes. It is a well-known oncogenic kinase that regulates vital cell autonomous functions and animal development. Genetic studies in the fruit fly Drosophila are providing unique insights into the roles of CK2 in cell signaling, embryogenesis, organogenesis, neurogenesis, and the circadian clock, and are revealing hitherto unknown complexities in CK2 functions and regulation. Here, we review Drosophila CK2 with respect to its structure, subunit diversity, potential mechanisms of regulation, developmental abnormalities linked to mutations in the gene encoding CK2 subunits, and emerging roles in multiple aspects of eye development. We examine the Drosophila CK2 “interaction map” and the eye-specific “transcriptome” databases, which raise the prospect that this protein kinase has many additional targets in the developing eye. We discuss the possibility that CK2 functions during early retinal neurogenesis in Drosophila and mammals bear greater similarity than has been recognized, and that this conservation may extend to other developmental programs. Together, these studies underscore the immense power of the Drosophila model organism to provide new insights and avenues to further investigate developmentally relevant targets of this protein kinase. PMID:28036067

A combined proteomic and genetic analysis identifies a role for the lipid desaturase Desat1 in starvation-induced autophagy in Drosophila.

PubMed

Köhler, Katja; Brunner, Erich; Guan, Xue Li; Boucke, Karin; Greber, Urs F; Mohanty, Sonali; Barth, Julia M I; Wenk, Markus R; Hafen, Ernst

2009-10-01

Autophagy is a lysosomal-mediated degradation process that promotes cell survival during nutrient-limiting conditions. However, excessive autophagy results in cell death. In Drosophila, autophagy is regulated nutritionally, hormonally and developmentally in several tissues, including the fat body, a nutrient-storage organ. Here we use a proteomics approach to identify components of starvation-induced autophagic responses in the Drosophila fat body. Using cICAT labeling and mass spectrometry, differences in protein expression levels of normal compared to starved fat bodies were determined. Candidates were analyzed genetically for their involvement in autophagy in fat bodies deficient for the respective genes. One of these genes, Desat1, encodes a lipid desaturase. Desat1 mutant cells fail to induce autophagy upon starvation. The desat1 protein localizes to autophagic structures after nutrient depletion and is required for fly development. Lipid analyses revealed that Desat1 regulates the composition of lipids in Drosophila. We propose that Desat1 exerts its role in autophagy by controlling lipid biosynthesis and/or signaling necessary for autophagic responses.

Progress and challenges in understanding planar cell polarity signaling.

PubMed

Axelrod, Jeffrey D

2009-10-01

During development, epithelial cells in some tissues acquire a polarity orthogonal to their apical-basal axis. This polarity, referred to as planar cell polarity (PCP), or tissue polarity, is essential for the normal physiological function of many epithelia. Early studies of PCP focused on insect epithelia (Lawrence, 1966 [1]), and the earliest genetic analyses were carried out in Drosophila (Held et al., 1986; Gubb and Garcia-Bellido, 1982 [2,3]). Indeed, most of our mechanistic understanding of PCP derives from the ongoing use of Drosophila as a model system. However, a range of medically important developmental defects and physiological processes are under the control of PCP mechanisms that appear to be at least partially conserved, driving considerable interest in studying PCP both in Drosophila and in vertebrate model systems. Here, I present a model of the PCP signaling mechanism based on studies in Drosophila. I highlight two areas in which our understanding is deficient, and which lead to current confusion in the literature. Future studies that shed light on these areas will substantially enhance our understanding of the fascinating yet challenging problem of understanding the mechanisms that generate PCP.

The peripheral nervous system supports blood cell homing and survival in the Drosophila larva

PubMed Central

Makhijani, Kalpana; Alexander, Brandy; Tanaka, Tsubasa; Rulifson, Eric; Brückner, Katja

2011-01-01

Interactions of hematopoietic cells with their microenvironment control blood cell colonization, homing and hematopoiesis. Here, we introduce larval hematopoiesis as the first Drosophila model for hematopoietic colonization and the role of the peripheral nervous system (PNS) as a microenvironment in hematopoiesis. The Drosophila larval hematopoietic system is founded by differentiated hemocytes of the embryo, which colonize segmentally repeated epidermal-muscular pockets and proliferate in these locations. Importantly, we show that these resident hemocytes tightly colocalize with peripheral neurons and we demonstrate that larval hemocytes depend on the PNS as an attractive and trophic microenvironment. atonal (ato) mutant or genetically ablated larvae, which are deficient for subsets of peripheral neurons, show a progressive apoptotic decline in hemocytes and an incomplete resident hemocyte pattern, whereas supernumerary peripheral neurons induced by ectopic expression of the proneural gene scute (sc) misdirect hemocytes to these ectopic locations. This PNS-hematopoietic connection in Drosophila parallels the emerging role of the PNS in hematopoiesis and immune functions in vertebrates, and provides the basis for the systematic genetic dissection of the PNS-hematopoietic axis in the future. PMID:22071105

Germ cell tumors: Insights from the Drosophila ovary and the mouse testis

PubMed Central

Salz, Helen K.; Dawson, Emily P.; Heaney, Jason D.

2017-01-01

SUMMARY Ovarian and testicular germ cell tumors of young adults are thought to arise from defects in germ cell development, but the molecular mechanisms underlying malignant transformation are poorly understood. In this review, we focus on the biology of germ cell tumor formation in the Drosophila ovary and the mouse testis, for which the evidence supports common underlying mechanisms such as blocking initiation into the differentiation pathway, impaired lineage progression, and sexual identity instability. We then discuss how these concepts inform our understanding of the disease in humans. PMID:28079292

Spectral Monitoring of Surfactant Clearance during Alveolar Epithelial Type II Cell Differentiation

PubMed Central

Swain, Robin J.; Kemp, Sarah J.; Goldstraw, Peter; Tetley, Teresa D.; Stevens, Molly M.

2008-01-01

In this study, we report on the noninvasive identification of spectral markers of alveolar type II (ATII) cell differentiation in vitro using Raman microspectroscopy. ATII cells are progenitor cells for alveolar type I (ATI) cells in vivo, and spontaneously differentiate toward an ATI-like phenotype in culture. We analyzed undifferentiated and differentiated primary human ATII cells, and correlated Raman spectral changes to cellular changes in morphology and marker protein synthesis (surfactant protein C, alkaline phosphatase, caveolin-1). Undifferentiated ATII cells demonstrated spectra with strong phospholipid vibrations, arising from alveolar surfactant stored within cytoplasmic lamellar bodies (Lbs). Differentiated ATI-like cells yielded spectra with significantly less lipid content. Factor analysis revealed a phospholipid-dominated spectral component as the main discriminator between the ATII and ATI-like phenotypes. Spectral modeling of the data revealed a significant decrease in the spectral contribution of cellular lipids—specifically phosphatidyl choline, the main constituent of surfactant, as ATII cells differentiate. These observations were consistent with the clearance of surfactant from Lbs as ATII cells differentiate, and were further supported by cytochemical staining for Lbs. These results demonstrate the first spectral characterization of primary human ATII cells, and provide insight into the biochemical properties of alveolar surfactant in its unperturbed cellular environment. PMID:18820234

Real-Time Three-Dimensional Cell Segmentation in Large-Scale Microscopy Data of Developing Embryos.

PubMed

Stegmaier, Johannes; Amat, Fernando; Lemon, William C; McDole, Katie; Wan, Yinan; Teodoro, George; Mikut, Ralf; Keller, Philipp J

2016-01-25

We present the Real-time Accurate Cell-shape Extractor (RACE), a high-throughput image analysis framework for automated three-dimensional cell segmentation in large-scale images. RACE is 55-330 times faster and 2-5 times more accurate than state-of-the-art methods. We demonstrate the generality of RACE by extracting cell-shape information from entire Drosophila, zebrafish, and mouse embryos imaged with confocal and light-sheet microscopes. Using RACE, we automatically reconstructed cellular-resolution tissue anisotropy maps across developing Drosophila embryos and quantified differences in cell-shape dynamics in wild-type and mutant embryos. We furthermore integrated RACE with our framework for automated cell lineaging and performed joint segmentation and cell tracking in entire Drosophila embryos. RACE processed these terabyte-sized datasets on a single computer within 1.4 days. RACE is easy to use, as it requires adjustment of only three parameters, takes full advantage of state-of-the-art multi-core processors and graphics cards, and is available as open-source software for Windows, Linux, and Mac OS. Copyright © 2016 Elsevier Inc. All rights reserved.

Loss of Drosophila A-type lamin C initially causes tendon abnormality including disintegration of cytoskeleton and nuclear lamina in muscular defects.

PubMed

Uchino, Ryo; Nonaka, Yu-Ki; Horigome, Tuneyoshi; Sugiyama, Shin; Furukawa, Kazuhiro

2013-01-01

Lamins are the major components of nuclear envelope architecture, being required for both the structural and informational roles of the nuclei. Mutations of lamins cause a spectrum of diseases in humans, including muscular dystrophy. We report here that the loss of the A-type lamin gene, lamin C in Drosophila resulted in pupal metamorphic lethality caused by tendon defects, matching the characteristics of human A-type lamin revealed by Emery-Dreifuss muscular dystrophy (EDMD). In tendon cells lacking lamin C activity, overall cell morphology was affected and organization of the spectraplakin family cytoskeletal protein Shortstop which is prominently expressed in tendon cells gradually disintegrated, notably around the nucleus and in a manner correlating well with the degradation of musculature. Furthermore, lamin C null mutants were efficiently rescued by restoring lamin C expression to shortstop-expressing cells, which include tendon cells but exclude skeletal muscle cells. Thus the critical function of A-type lamin C proteins in Drosophila musculature is to maintain proper function and morphology of tendon cells. Copyright © 2012 Elsevier Inc. All rights reserved.

Successful synthesis of active human coagulation factor VII by co-expression of mammalian gamma-glutamyl carboxylase and modification of vit.K cycle in Drosophila Schneider S2 cells.

PubMed

Nagahashi, Kotomi; Umemura, Kazuo; Kanayama, Naohiro; Iwaki, Takayuki

2017-04-01

Mammalian gamma-glutamyl carboxylase and reduced vitamin K are indispensable for synthesis of mature mammalian vitamin K dependent proteins including some of blood coagulation factors (factors II, VII, IX, and X). It was well known that Drosophila melanogaster expressed gamma-glutamyl carboxylase and possessed a vit.K cycle although native substrates for them have not been identified yet. Despite the potential capability of gamma carboxylation in D. melanogaster derived cells such as S2 cells, Drosophila gamma-glutamyl carboxylase failed to gamma carboxylate a peptide fused to the human coagulation factor IX propeptide. Thus, it had been believed that the Drosophila system was not adequate to synthesize mammalian vit.K dependent proteins. Indeed, we previously attempted to synthesize biologically active factor VII in S2 cells although we were not able to obtain it. However, recently, a successful transient expression of biologically active human factor IX from S2 cells was reported. In the present study, several expression vectors which enable expressing mammalian GGCX, VKORC1, and/or PDIA2 along with F7 were developed. S2 cells transfected with pMKA85, pMAK86, and pMAK219 successfully synthesized active FVII. Thus, mammalian GGCX was indispensable to synthesize active FVII while mammalian VKORC1 and PDIA2 were not critical but supportive factors for S2 cells.

Drosophila hemocyte migration: an in vivo assay for directional cell migration.

PubMed

Moreira, Carolina G A; Regan, Jennifer C; Zaidman-Rémy, Anna; Jacinto, Antonio; Prag, Soren

2011-01-01

This protocol describes an in vivo assay for random and directed hemocyte migration in Drosophila. Drosophila is becoming an increasingly powerful model system for in vivo cell migration analysis, combining unique genetic tools with translucency of the embryo and pupa, which allows direct imaging and traceability of different cell types. In the assay we present here, we make use of the hemocyte response to epithelium wounding to experimentally induce a transition from random to directed migration. Time-lapse confocal microscopy of hemocyte migration in untreated conditions provides a random cell migration assay that allows identification of molecular mechanisms involved in this complex process. Upon laser-induced wounding of the thorax epithelium, a rapid chemotactic response changes hemocyte migratory behavior into a directed migration toward the wound site. This protocol provides a direct comparison of cells during both types of migration in vivo, and combined with recently developed resources such as transgenic RNAi, is ideal for forward genetic screens.

Drosophila sessile hemocyte clusters are true hematopoietic tissues that regulate larval blood cell differentiation

PubMed Central

Leitão, Alexandre B; Sucena, Élio

2015-01-01

Virtually all species of coelomate animals contain blood cells that display a division of labor necessary for homeostasis. This functional partition depends upon the balance between proliferation and differentiation mostly accomplished in the hematopoietic organs. In Drosophila melanogaster, the lymph gland produces plasmatocytes and crystal cells that are not released until pupariation. Yet, throughout larval development, both hemocyte types increase in numbers. Mature plasmatocytes can proliferate but it is not known if crystal cell numbers increase by self-renewal or by de novo differentiation. We show that new crystal cells in third instar larvae originate through a Notch-dependent process of plasmatocyte transdifferentiation. This process occurs in the sessile clusters and is contingent upon the integrity of these structures. The existence of this hematopoietic tissue, relying on structure-dependent signaling events to promote blood homeostasis, creates a new paradigm for addressing outstanding questions in Drosophila hematopoiesis and establishing further parallels with vertebrate systems. DOI: http://dx.doi.org/10.7554/eLife.06166.001 PMID:25650737

Ecdysteroid receptors in Drosophila melanogaster adult females

USDA-ARS?s Scientific Manuscript database

Ecdysteroid receptors were identified and partially characterized from total cell extracts of whole animals and dissected tissues from Drosophila melanogaster adult females. Binding studies indicated the presence of two ecdysteroid binding components having high affinity and specificity consistent w...

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

Swenson, Joel M.; Colmenares, Serafin U.; Strom, Amy R.

Heterochromatin is enriched for specific epigenetic factors including Heterochromatin Protein 1a (HP1a), and is essential for many organismal functions. To elucidate heterochromatin organization and regulation, we purified Drosophila melanogaster HP1a interactors, and performed a genome-wide RNAi screen to identify genes that impact HP1a levels or localization. The majority of the over four hundred putative HP1a interactors and regulators identified were previously unknown. We found that 13 of 16 tested candidates (83%) are required for gene silencing, providing a substantial increase in the number of identified components that impact heterochromatin properties. Surprisingly, image analysis revealed that although some HP1a interactors andmore » regulators are broadly distributed within the heterochromatin domain, most localize to discrete subdomains that display dynamic localization patterns during the cell cycle. We conclude that heterochromatin composition and architecture is more spatially complex and dynamic than previously suggested, and propose that a network of subdomains regulates diverse heterochromatin functions.« less

The multidimensional ionotropic receptors of Drosophila melanogaster.

PubMed

Rimal, S; Lee, Y

2018-02-01

Ionotropic receptors (IRs), which form ion channels, can be categorized into conserved 'antennal IRs', which define the first olfactory receptor family of insects, and species-specific 'divergent IRs', which are expressed in gustatory receptor neurones. These receptors are located primarily in cell bodies and dendrites, and are highly enriched in the tips of the dendritic terminals that convey sensory information to higher brain centres. Antennal IRs play important roles in odour and thermosensation, whereas divergent IRs are involved in other important biological processes such as taste sensation. Some IRs are known to play specific biological roles in the perception of various molecules; however, many of their functions have not yet been defined. Although progress has been made in this field, many functions and mechanisms of these receptors remain unknown. In this review, we provide a comprehensive summary of the current state of knowledge in this field. © 2017 The Royal Entomological Society.

Deficiency in DNA damage response of enterocytes accelerates intestinal stem cell aging in Drosophila.

PubMed

Park, Joung-Sun; Jeon, Ho-Jun; Pyo, Jung-Hoon; Kim, Young-Shin; Yoo, Mi-Ae

2018-03-07

Stem cell dysfunction is closely linked to tissue and organismal aging and age-related diseases, and heavily influenced by the niche cells' environment. The DNA damage response (DDR) is a key pathway for tissue degeneration and organismal aging; however, the precise protective role of DDR in stem cell/niche aging is unclear. The Drosophila midgut is an excellent model to study the biology of stem cell/niche aging because of its easy genetic manipulation and its short lifespan. Here, we showed that deficiency of DDR in Drosophila enterocytes (ECs) accelerates intestinal stem cell (ISC) aging. We generated flies with knockdown of Mre11 , Rad50 , Nbs1 , ATM , ATR , Chk1 , and Chk2 , which decrease the DDR system in ECs. EC-specific DDR depletion induced EC death, accelerated the aging of ISCs, as evidenced by ISC hyperproliferation, DNA damage accumulation, and increased centrosome amplification, and affected the adult fly's survival. Our data indicated a distinct effect of DDR depletion in stem or niche cells on tissue-resident stem cell proliferation. Our findings provide evidence of the essential role of DDR in protecting EC against ISC aging, thus providing a better understanding of the molecular mechanisms of stem cell/niche aging.

Genotoxicity testing of different types of beverages in the Drosophila wing Somatic Mutation And Recombination Test.

PubMed

Graf, U; Moraga, A A; Castro, R; Díaz Carrillo, E

1994-05-01

Five wines and one brandy of Spanish origin as well as three herbal teas and ordinary black tea were tested for genotoxicity in the wing Somatic Mutation And Recombination Test (SMART) which makes use of the two recessive wing cell markers multiple wing hairs (mwh) and flare (flr3) on the left arm of chromosome 3 of Drosophila melanogaster. 3-day-old larvae trans-heterozygous for these two markers were fed the beverages at different concentrations and for different feeding periods using Drosophila instant medium. Somatic mutations or mitotic recombinations induced in the cells of the wing imaginal discs give rise to mutant single or twin spots on the wing blade of the emerging adult flies showing either the mwh phenotype or/and the flr phenotype. One of the red wines showed a clear genotoxic activity that was not due to its ethanol content. Two herbal teas (Urtica dioica, Achillea millefolium) and black tea (Camellia sinensis) proved to be weakly genotoxic as well. Furthermore, it was shown that quercetin and rutin, two flavonols present in beverages of plant origin, also exhibited weak genotoxic activity in the somatic cells of Drosophila. These results demonstrate that Drosophila in vivo somatic assays can detect the genotoxicity of complex mixtures such as beverages. In particular, it is possible to administer these test materials in the same form as that in which they are normally consumed.

Regulation of mTOR by Nutrients

DTIC Science & Technology

2012-07-01

individual genes (as indicated by the Drosophila genome CG numbers) were starved of amino acids for 1 h followed by amino acid stimulation for 30 min...acid signals. Knockdown of Rag gene expression suppressed the stimulatory effect of amino acids on TORC1 in Drosophila melanogaster S2 cells...Each individual DNA fragment was amplified with this primer by PCR from Drosophila genomic DNA and the PCR products were purified using the High Pure

Drosophila VAMP7 regulates Wingless intracellular trafficking.

PubMed

Gao, Han; He, Fang; Lin, Xinhua; Wu, Yihui

2017-01-01

Drosophila Wingless (Wg) is a morphogen that determines cell fate during development. Previous studies have shown that endocytic pathways regulate Wg trafficking and signaling. Here, we showed that loss of vamp7, a gene required for vesicle fusion, dramatically increased Wg levels and decreased Wg signaling. Interestingly, we found that levels of Dally-like (Dlp), a glypican that can interact with Wg to suppress Wg signaling at the dorsoventral boundary of the Drosophila wing, were also increased in vamp7 mutant cells. Moreover, Wg puncta in Rab4-dependent recycling endosomes were Dlp positive. We hypothesize that VAMP7 is required for Wg intracellular trafficking and the accumulation of Wg in Rab4-dependent recycling endosomes might affect Wg signaling.

A regulatory circuit for piwi by the large Maf gene traffic jam in Drosophila.

PubMed

Saito, Kuniaki; Inagaki, Sachi; Mituyama, Toutai; Kawamura, Yoshinori; Ono, Yukiteru; Sakota, Eri; Kotani, Hazuki; Asai, Kiyoshi; Siomi, Haruhiko; Siomi, Mikiko C

2009-10-29

PIWI-interacting RNAs (piRNAs) silence retrotransposons in Drosophila germ lines by associating with the PIWI proteins Argonaute 3 (AGO3), Aubergine (Aub) and Piwi. piRNAs in Drosophila are produced from intergenic repetitive genes and piRNA clusters by two systems: the primary processing pathway and the amplification loop. The amplification loop occurs in a Dicer-independent, PIWI-Slicer-dependent manner. However, primary piRNA processing remains elusive. Here we analysed piRNA processing in a Drosophila ovarian somatic cell line where Piwi, but not Aub or AGO3, is expressed; thus, only the primary piRNAs exist. In addition to flamenco, a Piwi-specific piRNA cluster, traffic jam (tj), a large Maf gene, was determined as a new piRNA cluster. piRNAs arising from tj correspond to the untranslated regions of tj messenger RNA and are sense-oriented. piRNA loading on to Piwi may occur in the cytoplasm. zucchini, a gene encoding a putative cytoplasmic nuclease, is required for tj-derived piRNA production. In tj and piwi mutant ovaries, somatic cells fail to intermingle with germ cells and Fasciclin III is overexpressed. Loss of tj abolishes Piwi expression in gonadal somatic cells. Thus, in gonadal somatic cells, tj gives rise simultaneously to two different molecules: the TJ protein, which activates Piwi expression, and piRNAs, which define the Piwi targets for silencing.

Chondrogenic Differentiation Increases Antidonor Immune Response to Allogeneic Mesenchymal Stem Cell Transplantation

PubMed Central

Ryan, Aideen E; Lohan, Paul; O'Flynn, Lisa; Treacy, Oliver; Chen, Xizhe; Coleman, Cynthia; Shaw, Georgina; Murphy, Mary; Barry, Frank; Griffin, Matthew D; Ritter, Thomas

2014-01-01

Allogeneic mesenchymal stem cells (allo-MSCs) have potent regenerative and immunosuppressive potential and are being investigated as a therapy for osteoarthritis; however, little is known about the immunological changes that occur in allo-MSCs after ex vivo induced or in vivo differentiation. Three-dimensional chondrogenic differentiation was induced in an alginate matrix, which served to immobilize and potentially protect MSCs at the site of implantation. We show that allogeneic differentiated MSCs lost the ability to inhibit T-cell proliferation in vitro, in association with reduced nitric oxide and prostaglandin E2 secretion. Differentiation altered immunogenicity as evidenced by induced proliferation of allogeneic T cells and increased susceptibility to cytotoxic lysis by allo-specific T cells. Undifferentiated or differentiated allo-MSCs were implanted subcutaneously, with and without alginate encapsulation. Increased CD3+ and CD68+ infiltration was evident in differentiated and splenocyte encapsulated implants only. Without encapsulation, increased local memory T-cell responses were detectable in recipients of undifferentiated and differentiated MSCs; however, only differentiated MSCs induced systemic memory T-cell responses. In recipients of encapsulated allogeneic cells, only differentiated allo-MSCs induced memory T-cell responses locally and systemically. Systemic alloimmune responses to differentiated MSCs indicate immunogenicity regardless of alginate encapsulation and may require immunosuppressive therapy for therapeutic use. PMID:24184966

Hedgehog restricts its expression domain in the Drosophila wing

PubMed Central

Bejarano, Fernando; Pérez, Lidia; Apidianakis, Yiorgos; Delidakis, Christos; Milán, Marco

2007-01-01

The stable subdivision of Drosophila limbs into anterior and posterior compartments is a consequence of asymmetrical signalling by Hedgehog (Hh), from the posterior to anterior cells. The activity of the homeodomain protein Engrailed in posterior cells helps to generate this asymmetry by inducing the expression of Hh in the posterior compartment and, at the same time, repressing the expression of the essential downstream component Cubitus interruptus (Ci). Therefore, only anterior cells that receive the Hh signal across the compartment boundary will respond by stabilizing Ci. Here, we describe a new molecular mechanism that helps to maintain the Hh-expressing and Hh-responding cells in different non-overlapping cell populations. Master of thickveins (mtv)—a target of Hh activity encoding a nuclear zinc-finger protein—is required to repress hh expression in anterior cells. Mtv exerts this action in a protein complex with Groucho (Gro)—the founding member of a superfamily of transcriptional corepressors that are conserved throughout eukaryotes. Therefore, Hh restricts its own expression domain in the Drosophila wing through the activity of Mtv and Gro. PMID:17571073

The Drosophila blood-brain barrier: development and function of a glial endothelium.

PubMed

Limmer, Stefanie; Weiler, Astrid; Volkenhoff, Anne; Babatz, Felix; Klämbt, Christian

2014-01-01

The efficacy of neuronal function requires a well-balanced extracellular ion homeostasis and a steady supply with nutrients and metabolites. Therefore, all organisms equipped with a complex nervous system developed a so-called blood-brain barrier, protecting it from an uncontrolled entry of solutes, metabolites or pathogens. In higher vertebrates, this diffusion barrier is established by polarized endothelial cells that form extensive tight junctions, whereas in lower vertebrates and invertebrates the blood-brain barrier is exclusively formed by glial cells. Here, we review the development and function of the glial blood-brain barrier of Drosophila melanogaster. In the Drosophila nervous system, at least seven morphologically distinct glial cell classes can be distinguished. Two of these glial classes form the blood-brain barrier. Perineurial glial cells participate in nutrient uptake and establish a first diffusion barrier. The subperineurial glial (SPG) cells form septate junctions, which block paracellular diffusion and thus seal the nervous system from the hemolymph. We summarize the molecular basis of septate junction formation and address the different transport systems expressed by the blood-brain barrier forming glial cells.

Differential splicing generates a nervous system-specific form of Drosophila neuroglian.

PubMed

Hortsch, M; Bieber, A J; Patel, N H; Goodman, C S

1990-05-01

We recently described the characterization and cloning of Drosophila neuroglian, a member of the immunoglobulin superfamily. Neuroglian contains six immunoglobulin-like domains and five fibronectin type III domains and shows strong sequence homology to the mouse neural cell adhesion molecule L1. Here we show that the neuroglian gene generates at least two different protein products by tissue-specific alternative splicing. The two protein forms differ in their cytoplasmic domains. The long form is restricted to the surface of neurons in the CNS and neurons and some support cells in the PNS; in contrast, the short form is expressed on a wide range of other cells and tissues. Thus, whereas the mouse L1 gene appears to encode only one protein that functions largely as a neural cell adhesion molecule, its Drosophila homolog, the neuroglian gene, encodes at least two protein forms that may play two different roles, one as a neural cell adhesion molecule and the other as a more general cell adhesion molecule involved in other tissues and imaginal disc morphogenesis.

Negative and positive regulation by a short segment in the 5'-flanking region of the human cytomegalovirus major immediate-early gene

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

Nelson, J.A.; Reynolds-Kohler, C.; Smith, B.A.

1987-11-01

To analyze the significance of inducible DNase I-hypersensitive sites occurring in the 5'-flanking sequence of the major immediate-early gene of human cytomegalovirus (HCMV), various deleted portions of the HCMV immediate-early promoter regulatory region were attached to the chloramphenicol acetyltransferase (CAT) gene and assayed for activity in transiently transfected undifferentiated and differentiated human teratocarcinoma cells, Tera-2. Assays of progressive deletions in the promoter regulatory region indicated that removal of a 395-base-pair portion of this element (nucleotides -750 to -1145) containing two inducible DNase I sites which correlate with gene expression resulted in a 7.5-fold increase in CAT activity in undifferentiated cells.more » However, in permissive differentiated Tera-2, human foreskin fibroblast, and HeLa cells, removal of this regulatory region resulted in decreased activity. In addition, attachment of this HCMV upstream element to a homologous or heterologous promoter increased activity three-to fivefold in permissive cells. Therefore, a cis regulatory element exists 5' to the enhancer of the major immediate-early gene of HCMV. This element negatively modulates expression in nonpermissive cells but positively influences expression in permissive cells.« less

Inefficient reprogramming of the hematopoietic stem cell genome following nuclear transfer.

PubMed

Inoue, Kimiko; Ogonuki, Narumi; Miki, Hiromi; Hirose, Michiko; Noda, Shinichi; Kim, Jin-Moon; Aoki, Fugaku; Miyoshi, Hiroyuki; Ogura, Atsuo

2006-05-15

In general, cloning undifferentiated preimplantation embryos (blastomeres) or embryonic stem cells is more efficient than cloning differentiated somatic cells. Therefore, there has been an assumption that tissue-specific stem cells might serve as efficient donors for nuclear transfer because of the undifferentiated state of their genome. Here, we show that this is not the case with adult hematopoietic stem cells (HSCs). Although we have demonstrated for the first time that mouse HSCs can be cloned to generate offspring, the birth rates (0-0.7%) were lowest among the clones tested (cumulus, immature Sertoli and fibroblast cells). Only 6% of reconstructed embryos reached the morula or blastocyst stage in vitro (versus 46% for cumulus clones; P < 5 x 10(-10)). Transcription and gene expression analyses of HSC clone embryos revealed that they initiated zygotic gene activation (ZGA) at the appropriate timing, but failed to activate five out of six important embryonic genes examined, including Hdac1 (encoding histone deacetylase 1), a key regulator of subsequent ZGA. These results suggest that the HSC genome has less plasticity than we imagined, at least in terms of reprogrammability in the ooplasm after nuclear transfer.

Cellular network entropy as the energy potential in Waddington's differentiation landscape

PubMed Central

Banerji, Christopher R. S.; Miranda-Saavedra, Diego; Severini, Simone; Widschwendter, Martin; Enver, Tariq; Zhou, Joseph X.; Teschendorff, Andrew E.

2013-01-01

Differentiation is a key cellular process in normal tissue development that is significantly altered in cancer. Although molecular signatures characterising pluripotency and multipotency exist, there is, as yet, no single quantitative mark of a cellular sample's position in the global differentiation hierarchy. Here we adopt a systems view and consider the sample's network entropy, a measure of signaling pathway promiscuity, computable from a sample's genome-wide expression profile. We demonstrate that network entropy provides a quantitative, in-silico, readout of the average undifferentiated state of the profiled cells, recapitulating the known hierarchy of pluripotent, multipotent and differentiated cell types. Network entropy further exhibits dynamic changes in time course differentiation data, and in line with a sample's differentiation stage. In disease, network entropy predicts a higher level of cellular plasticity in cancer stem cell populations compared to ordinary cancer cells. Importantly, network entropy also allows identification of key differentiation pathways. Our results are consistent with the view that pluripotency is a statistical property defined at the cellular population level, correlating with intra-sample heterogeneity, and driven by the degree of signaling promiscuity in cells. In summary, network entropy provides a quantitative measure of a cell's undifferentiated state, defining its elevation in Waddington's landscape. PMID:24154593

SWI/SNF Associates with Nascent Pre-mRNPs and Regulates Alternative Pre-mRNA Processing

PubMed Central

Tyagi, Anu; Ryme, Jessica; Brodin, David; Östlund Farrants, Ann Kristin; Visa, Neus

2009-01-01

The SWI/SNF chromatin remodeling complexes regulate the transcription of many genes by remodeling nucleosomes at promoter regions. In Drosophila, SWI/SNF plays an important role in ecdysone-dependent transcription regulation. Studies in human cells suggest that Brahma (Brm), the ATPase subunit of SWI/SNF, regulates alternative pre-mRNA splicing by modulating transcription elongation rates. We describe, here, experiments that study the association of Brm with transcribed genes in Chironomus tentans and Drosophila melanogaster, the purpose of which was to further elucidate the mechanisms by which Brm regulates pre-mRNA processing. We show that Brm becomes incorporated into nascent Balbiani ring pre-mRNPs co-transcriptionally and that the human Brm and Brg1 proteins are associated with RNPs. We have analyzed the expression profiles of D. melanogaster S2 cells in which the levels of individual SWI/SNF subunits have been reduced by RNA interference, and we show that depletion of SWI/SNF core subunits changes the relative abundance of alternative transcripts from a subset of genes. This observation, and the fact that a fraction of Brm is not associated with chromatin but with nascent pre-mRNPs, suggest that SWI/SNF affects pre-mRNA processing by acting at the RNA level. Ontology enrichment tests indicate that the genes that are regulated post-transcriptionally by SWI/SNF are mostly enzymes and transcription factors that regulate postembryonic developmental processes. In summary, the data suggest that SWI/SNF becomes incorporated into nascent pre-mRNPs and acts post-transcriptionally to regulate not only the amount of mRNA synthesized from a given promoter but also the type of alternative transcript produced. PMID:19424417

Moderate restriction of macrophage-tropic human immunodeficiency virus type 1 by SAMHD1 in monocyte-derived macrophages.

PubMed

Taya, Kahoru; Nakayama, Emi E; Shioda, Tatsuo

2014-01-01

Macrophage-tropic human immunodeficiency virus type 1 (HIV-1) strains are able to grow to high titers in human monocyte-derived macrophages. However, it was recently reported that cellular protein SAMHD1 restricts HIV-1 replication in human cells of the myeloid lineage, including monocyte-derived macrophages. Here we show that degradation of SAMHD1 in monocyte-derived macrophages was associated with moderately enhanced growth of the macrophage-tropic HIV-1 strain. SAMHD1 degradation was induced by treating target macrophages with vesicular stomatitis virus glycoprotein-pseudotyped human immunodeficiency virus type 2 (HIV-2) particles containing viral protein X. For undifferentiated monocytes, HIV-2 particle treatment allowed undifferentiated monocytes to be fully permissive for productive infection by the macrophage-tropic HIV-1 strain. In contrast, untreated monocytes were totally resistant to HIV-1 replication. These results indicated that SAMHD1 moderately restricts even a macrophage-tropic HIV-1 strain in monocyte-derived macrophages, whereas the protein potently restricts HIV-1 replication in undifferentiated monocytes.

Human Intellectual Disability Genes Form Conserved Functional Modules in Drosophila

PubMed Central

Oortveld, Merel A. W.; Keerthikumar, Shivakumar; Oti, Martin; Nijhof, Bonnie; Fernandes, Ana Clara; Kochinke, Korinna; Castells-Nobau, Anna; van Engelen, Eva; Ellenkamp, Thijs; Eshuis, Lilian; Galy, Anne; van Bokhoven, Hans; Habermann, Bianca; Brunner, Han G.; Zweier, Christiane; Verstreken, Patrik; Huynen, Martijn A.; Schenck, Annette

2013-01-01

Intellectual Disability (ID) disorders, defined by an IQ below 70, are genetically and phenotypically highly heterogeneous. Identification of common molecular pathways underlying these disorders is crucial for understanding the molecular basis of cognition and for the development of therapeutic intervention strategies. To systematically establish their functional connectivity, we used transgenic RNAi to target 270 ID gene orthologs in the Drosophila eye. Assessment of neuronal function in behavioral and electrophysiological assays and multiparametric morphological analysis identified phenotypes associated with knockdown of 180 ID gene orthologs. Most of these genotype-phenotype associations were novel. For example, we uncovered 16 genes that are required for basal neurotransmission and have not previously been implicated in this process in any system or organism. ID gene orthologs with morphological eye phenotypes, in contrast to genes without phenotypes, are relatively highly expressed in the human nervous system and are enriched for neuronal functions, suggesting that eye phenotyping can distinguish different classes of ID genes. Indeed, grouping genes by Drosophila phenotype uncovered 26 connected functional modules. Novel links between ID genes successfully predicted that MYCN, PIGV and UPF3B regulate synapse development. Drosophila phenotype groups show, in addition to ID, significant phenotypic similarity also in humans, indicating that functional modules are conserved. The combined data indicate that ID disorders, despite their extreme genetic diversity, are caused by disruption of a limited number of highly connected functional modules. PMID:24204314

Human intellectual disability genes form conserved functional modules in Drosophila.

PubMed

Oortveld, Merel A W; Keerthikumar, Shivakumar; Oti, Martin; Nijhof, Bonnie; Fernandes, Ana Clara; Kochinke, Korinna; Castells-Nobau, Anna; van Engelen, Eva; Ellenkamp, Thijs; Eshuis, Lilian; Galy, Anne; van Bokhoven, Hans; Habermann, Bianca; Brunner, Han G; Zweier, Christiane; Verstreken, Patrik; Huynen, Martijn A; Schenck, Annette

2013-10-01

Intellectual Disability (ID) disorders, defined by an IQ below 70, are genetically and phenotypically highly heterogeneous. Identification of common molecular pathways underlying these disorders is crucial for understanding the molecular basis of cognition and for the development of therapeutic intervention strategies. To systematically establish their functional connectivity, we used transgenic RNAi to target 270 ID gene orthologs in the Drosophila eye. Assessment of neuronal function in behavioral and electrophysiological assays and multiparametric morphological analysis identified phenotypes associated with knockdown of 180 ID gene orthologs. Most of these genotype-phenotype associations were novel. For example, we uncovered 16 genes that are required for basal neurotransmission and have not previously been implicated in this process in any system or organism. ID gene orthologs with morphological eye phenotypes, in contrast to genes without phenotypes, are relatively highly expressed in the human nervous system and are enriched for neuronal functions, suggesting that eye phenotyping can distinguish different classes of ID genes. Indeed, grouping genes by Drosophila phenotype uncovered 26 connected functional modules. Novel links between ID genes successfully predicted that MYCN, PIGV and UPF3B regulate synapse development. Drosophila phenotype groups show, in addition to ID, significant phenotypic similarity also in humans, indicating that functional modules are conserved. The combined data indicate that ID disorders, despite their extreme genetic diversity, are caused by disruption of a limited number of highly connected functional modules.

Manipulation of gene expression by infrared laser heat shock and its application to the study of tracheal development in Drosophila.

PubMed

Miao, Guangxia; Hayashi, Shigeo

2015-03-01

Induction of gene expression in a specific cell and a defined time window is desirable to investigate gene function at the cellular level during morphogenesis. To achieve this, we attempted to introduce the infrared laser-evoked gene operator system (IR-LEGO, Kamei et al., 2009) in the Drosophila embryo. In this technique, infrared laser light illumination induces genes to be expressed under the control of heat shock promoters at the single cell level. We applied IR-LEGO to a transgenic fly stock, HS-eGFP, in which the enhanced green fluorescent protein (eGFP) gene is placed under the control of heat shock protein 70 promoter, and showed that eGFP expression can be induced in single cells within 1-2 hr after IR illumination. Furthermore, induction of HS-Branchless transgene encoding the Drosophila fibroblast growth factor (FGF) effectively altered the migration and branching patterns of the tracheal system. Our results indicated that IR-LEGO is a promising choice for the timely control of gene expression in a small group of cells in the Drosophila embryo. By using IR-LEGO, we further demonstrated that the tracheal terminal branching program is sensitive to localized expression of exogenous FGF. © 2014 Wiley Periodicals, Inc.

[Expression of embryonic markers in pterygium derived mesenchymal cells].

PubMed

Pascual, G; Montes, M A; Pérez-Rico, C; Pérez-Kohler, B; Bellón, J M; Buján, J

2010-12-01

Destruction of the limbal epithelium barrier is the most important mechanism of pterygium formation (conjunctiva proliferation, encroaching onto the cornea). It is thought to arise from activated and proliferating limbal epithelial stem cells. The objective of this study is to evaluate the presence of undifferentiated mesenchymal cells (stem cells) in cultured cells extracted from human pterygium. Cells from 6 human pterygium were isolated by explantation and placed in cultures with amniomax medium. Once the monolayer was reached the cells were seeded onto 24 well microplates. The cells were studied in the second sub-culture. The immunohistochemical expression of different embryonic stem cell markers, OCT3/4 and CD9, was analysed. The differentiated phenotypes were characterised with the monoclonal antibodies anti-CD31, α-actin and vimentin. All the cell populations obtained from pterygium showed vimentin expression. Less than 1% of the cells were positive for CD31 and α-actin markers. The majority of the cell population was positive for OCT3/4 and CD9. The cell population obtained from pterygium expressed mesenchymal cell phenotype and embryonic markers, such us OCT3/4 and CD9. This undifferentiated population could be involved in the large recurrence rate of this type of tissue after surgery. Copyright © 2010 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

Application of Stem Cells in Oral Disease Therapy: Progresses and Perspectives

PubMed Central

Yang, Bo; Qiu, Yi; Zhou, Niu; Ouyang, Hong; Ding, Junjun; Cheng, Bin; Sun, Jianbo

2017-01-01

Stem cells are undifferentiated and pluripotent cells that can differentiate into specialized cells with a more specific function. Stem cell therapies become preferred methods for the treatment of multiple diseases. Oral and maxillofacial defect is one kind of the diseases that could be most possibly cured by stem cell therapies. Here we discussed oral diseases, oral adult stem cells, iPS cells, and the progresses/challenges/perspectives of application of stem cells for oral disease treatment. PMID:28421002