scholarly journals Cellular labeling of endogenous retrovirus replication (CLEVR) reveals de novo insertions of the gypsy retrotransposable element in cell culture and in both neurons and glial cells of aging fruit flies

PLoS Biology ◽  
2019 ◽  
Vol 17 (5) ◽  
pp. e3000278 ◽  
Author(s):  
Yung-Heng Chang ◽  
Richard M. Keegan ◽  
Lisa Prazak ◽  
Josh Dubnau
Keyword(s):  
Cell Culture ◽  
Glial Cells ◽  
De Novo ◽  
Endogenous Retrovirus ◽  
Fruit Flies ◽  
Retrotransposable Element ◽  
Cellular Labeling ◽  
Retrovirus Replication

scholarly journals Cellular labeling of endogenous virus replication (CLEVR) reveals de novo insertions of the gypsy endogenous retrovirus in cell culture and in both neurons and glial cells of aging fruit flies

2018 ◽  
Author(s):  
Yung-Heng Chang ◽  
Richard M. Keegan ◽  
Lisa Prazak ◽  
Josh Dubnau
Keyword(s):  
Cell Culture ◽  
Glial Cells ◽  
De Novo ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Ltr Retrotransposons ◽  
Endogenous Virus ◽  
Gypsy Element ◽  
Element Mobilization

AbstractEvidence is rapidly mounting that transposable element expression and replication may impact biology more widely than previously thought. This includes potential effects on normal physiology of somatic tissues and dysfunctional impacts in diseases associated with aging such as cancer and neurodegeneration. Investigation of the biological impact of mobile elements in somatic cells will be greatly facilitated by use of donor elements that are engineered to report de novo events in vivo. In multicellular organisms, successful reporters of LINE element mobilization have been in use for some time, but similar strategies have not been developed to report Long Terminal Repeat (LTR) retrotransposons and endogenous retroviruses. We describe Cellular Labeling of Endogenous Virus Replication (CLEVR), which reports replication of the gypsy element in Drosophila. The gypsy-CLEVR reporter reveals gypsy replication both in cell culture and in individual neurons and glial cells of the aging adult fly. We also demonstrate that the gypsy-CLEVR replication rate is increased when the short interfering RNA silencing system is genetically disrupted. This CLEVR strategy makes use of universally conserved features of retroviruses and should be widely applicable to other LTR-retrotransposons, endogenous retroviruses and exogenous retroviruses.

scholarly journals Unique Features of Hepatitis C Virus Capsid Formation Revealed by De Novo Cell-Free Assembly

2004 ◽  
Vol 78 (17) ◽  
pp. 9257-9269 ◽  
Author(s):  
Kevin C. Klein ◽  
Stephen J. Polyak ◽  
Jaisri R. Lingappa
Keyword(s):  
Cell Culture ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
De Novo ◽  
Signal Sequence ◽  
Buoyant Density ◽  
Capsid Assembly ◽  
Culture Systems ◽  
Capsid Formation ◽  
Cell Culture Systems

ABSTRACT The assembly of hepatitis C virus (HCV) is poorly understood, largely due to the lack of mammalian cell culture systems that are easily manipulated and produce high titers of virus. This problem is highlighted by the inability of the recently established HCV replicon systems to support HCV capsid assembly despite high levels of structural protein synthesis. Here we demonstrate that up to 80% of HCV core protein synthesized de novo in cell-free systems containing rabbit reticulocyte lysate or wheat germ extracts assembles into HCV capsids. This contrasts with standard primate cell culture systems, in which almost no core assembles into capsids. Cell-free HCV capsids, which have a sedimentation value of ≈100S, have a buoyant density (1.28 g/ml) on cesium chloride similar to that of HCV capsids from other systems. Capsids produced in cell-free systems are also indistinguishable from capsids isolated from HCV-infected patient serum when analyzed by transmission electron microscopy. Using these cell-free systems, we show that HCV capsid assembly is independent of signal sequence cleavage, is dependent on the N terminus but not the C terminus of HCV core, proceeds at very low nascent chain concentrations, is independent of intact membrane surfaces, and is partially inhibited by cultured liver cell lysates. By allowing reproducible and quantitative assessment of viral and cellular requirements for capsid formation, these cell-free systems make a mechanistic dissection of HCV capsid assembly possible.

Long-term cell culture of electrically active sensory neurons free of glial cells

1977 ◽  
Vol 5 (3-4) ◽  
pp. 153-157 ◽  
Author(s):  
Ellen Rieske ◽  
Georg W. Kreutzberg
Keyword(s):  
Cell Culture ◽  
Sensory Neurons ◽  
Glial Cells

scholarly journals Human endogenous retrovirus transcription profiles of the kidney and kidney-derived cell lines

2011 ◽  
Vol 92 (10) ◽  
pp. 2356-2366 ◽  
Author(s):  
Sonja Haupt ◽  
Michele Tisdale ◽  
Michelle Vincendeau ◽  
Mary Anne Clements ◽  
David T. Gauthier ◽  
...  
Keyword(s):  
Cell Culture ◽  
Cell Line ◽  
Cell Lines ◽  
Kidney Tissue ◽  
Human Kidney ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Human Endogenous Retrovirus ◽  
Tissue Samples ◽  
Transcription Pattern

The human genome comprises approximately 8–9 % of human endogenous retroviruses (HERVs) that are transcribed with tissue specificity. However, relatively few organs have been examined in detail for individual differences in HERV transcription pattern, nor have tissue-to-cell culture comparisons been frequently performed. Using an HERV-specific DNA microarray, a core HERV transcription profile was established for the human kidney comparing 10 tissue samples. This core represents HERV groups expressed uniformly or nearly so in non-tumour kidney tissue. The profiles obtained from non-tumour tissues were compared to 10 renal tumour tissues (renal cell carcinoma, RCC) derived from the same individuals and additionally, to 22 RCC cell lines. No RCC cell line or tumour-specific differences were observed, suggesting that HERV transcription is not altered in RCC. However, when comparing tissue transcription to cell line transcription, there were consistent differences. The differences were irrespective of cancer state and included cell lines derived from non-tumour kidney tissue, suggesting that a specific alteration of HERV transcription occurs when establishing cell lines. In contrast to previous publications, all known HERV-derived tumour antigens, including those identified in RCC, were expressed both in multiple RCC cell lines and several non-tumour tissue-derived cell lines, a result that contrasts with findings from patient samples. The results establish the core kidney transcription pattern of HERVs and reveal differences between cell culture lines and tissue samples.

Inhibition of neurotropic mouse retrovirus replication in glial cells by synthetic oligo(2′-O-methyl)ribonucleoside phosphorothioates

1995 ◽  
Vol 28 (4) ◽  
pp. 359-368
Author(s):  
Sayaka Takase-Yoden ◽  
Susumu Shibahara ◽  
Hirokazu Morisawa ◽  
Rihito Watanabe
Keyword(s):  
Glial Cells ◽  
Retrovirus Replication

scholarly journals A lipid-free and insulin-supplemented medium supports de novo fatty acid synthesis gene activation in melanoma cells

2018 ◽  
Author(s):  
Su Wu ◽  
Anders M. Näär
Keyword(s):  
Cell Culture ◽  
Fatty Acid ◽  
Cell Lines ◽  
Melanoma Cell ◽  
De Novo ◽  
Melanoma Cells ◽  
Controlled Study ◽  
Gene Promoters ◽  
Medium Condition ◽  
Melanoma Cell Lines

AbstractWhile investigating the role played by de novo lipid (DNL) biosynthesis in cancer cells, we sought a medium condition that would support cell proliferation without providing any serum lipids. Here we report that a defined serum free cell culture medium condition containing insulin, transferrin and selenium (ITS) supports controlled study of transcriptional regulation of de novo fatty acid (DNFA) production and de novo cholesterol synthesis (DNCS) in melanoma cell lines. This lipid-free ITS medium is able to support continuous proliferation of several melanoma cell lines that utilize DNL to support their lipid requirements. We show that the ITS medium stimulates gene transcription in support of both DNFA and DNCS, specifically mediated by SREBP1/2 in melanoma cells. We further found that the ITS medium promoted SREBP1 nuclear localization and occupancy on DNFA gene promoters. Our data show clear utility of this serum and lipid-free medium for melanoma cancer cell culture and lipid-related areas of investigation.

Evidence for De Novo rearrangements of Drosophila transposable elements induced by the passage to the cell culture

Genetica ◽  
1992 ◽  
Vol 87 (2) ◽  
pp. 65-73 ◽  
Author(s):  
C. Di Franco ◽  
C. Pisano ◽  
F. Fourcade-Peronnet ◽  
G. Echalier ◽  
N. Junakovic
Keyword(s):  
Cell Culture ◽  
Transposable Elements ◽  
De Novo

scholarly journals GDNF, A Neuron-Derived Factor Upregulated in Glial Cells during Disease

2020 ◽  
Vol 9 (2) ◽  
pp. 456 ◽  
Author(s):  
Marcelo Duarte Azevedo ◽  
Sibilla Sander ◽  
Liliane Tenenbaum
Keyword(s):  
Glial Cell ◽  
Glial Cells ◽  
Motor Neurons ◽  
Cell Activation ◽  
De Novo ◽  
Adult Brain ◽  
Enteric Neurons ◽  
Complex Signals ◽  
Glial Cell Activation ◽  
Injured Brain

In a healthy adult brain, glial cell line-derived neurotrophic factor (GDNF) is exclusively expressed by neurons, and, in some instances, it has also been shown to derive from a single neuronal subpopulation. Secreted GDNF acts in a paracrine fashion by forming a complex with the GDNF family receptor α1 (GFRα1), which is mainly expressed by neurons and can act in cis as a membrane-bound factor or in trans as a soluble factor. The GDNF/GFRα1 complex signals through interactions with the “rearranged during transfection” (RET) receptor or via the neural cell adhesion molecule (NCAM) with a lower affinity. GDNF can also signal independently from GFRα1 by interacting with syndecan-3. RET, which is expressed by neurons involved in several pathways (nigro–striatal dopaminergic neurons, motor neurons, enteric neurons, sensory neurons, etc.), could be the main determinant of the specificity of GDNF’s pro-survival effect. In an injured brain, de novo expression of GDNF occurs in glial cells. Neuroinflammation has been reported to induce GDNF expression in activated astrocytes and microglia, infiltrating macrophages, nestin-positive reactive astrocytes, and neuron/glia (NG2) positive microglia-like cells. This disease-related GDNF overexpression can be either beneficial or detrimental depending on the localization in the brain and the level and duration of glial cell activation. Some reports also describe the upregulation of RET and GFRα1 in glial cells, suggesting that GDNF could modulate neuroinflammation.

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