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  1. Book ; Online ; Thesis: Growth-differentiation-factor 15 und Activin A als Biomarker für die pulmonale Hypertonie

    Kempf, Christoph [Verfasser]

    2017  

    Author's details Christoph Kempf
    Keywords Medizin, Gesundheit ; Medicine, Health
    Subject code sg610
    Language German
    Publisher Universitätsbibliothek
    Publishing place Gießen
    Document type Book ; Online ; Thesis
    Database Digital theses on the web

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  2. Article ; Online: Uptake of Gadolinium-Based Contrast Agents by Blood Cells During Contrast-Enhanced MRI Examination.

    Ruprecht, Nico / Parakkattel, Dixy / Hofmann, Lukas / Broekmann, Peter / Lüdi, Nicola / Kempf, Christoph / Heverhagen, Johannes Thomas / von Tengg-Kobligk, Hendrik

    Investigative radiology

    2023  Volume 59, Issue 5, Page(s) 372–378

    Abstract: Objectives: Gadolinium-based contrast agents (GBCAs) are routinely used in magnetic resonance imaging (MRI) examinations. However, there is limited knowledge about the interaction with and distribution of the drug in human cells. This lack of knowledge ... ...

    Abstract Objectives: Gadolinium-based contrast agents (GBCAs) are routinely used in magnetic resonance imaging (MRI) examinations. However, there is limited knowledge about the interaction with and distribution of the drug in human cells. This lack of knowledge is surprising, given that the first interaction of the drug occurs with blood cells. Moreover, recent studies reported gadolinium (Gd) deposition within organs, such as the brain. Hence, this study is aiming to determine the uptake of GBCA in blood cells of patients undergoing contrast-enhanced MRI (ce-MRI) examination.
    Materials and methods: Human blood was exposed to either gadoterate meglumine (Gd-DOTA) or Eu-DOTA in vitro or was collected from patients undergoing ce-MRI with Gd-DOTA. Uptake of contrast agents (CAs) by blood cells was quantified by Gd measurements using single-cell inductively coupled plasma mass spectrometry (SC-ICP-MS) or, to confirm Gd-DOTA uptake, by a complementary method using Eu-DOTA by time-resolved fluorescence spectroscopy, respectively.
    Results: Uptake of Gd-DOTA or Eu-DOTA into white blood cells (WBCs) ex vivo was detectable by SC-ICP-MS and time-resolved fluorescence spectroscopy. The intracellular concentrations were estimated to be in the range of 1-3 μM. However, no CA uptake into erythrocytes was detected with either method. In total, 42 patients between 30 and 84 years old (24 men, 18 women) were enrolled. White blood cells' uptake of Gd was measured by SC-ICP-MS. Isolated WBCs from patients who underwent ce-MRI examination showed substantial Gd uptake; however, the studied patient group showed an inhomogeneous distribution of Gd uptake. Measurements immediately after MRI examination indicated 21-444 attogram/WBC, corresponding to an intracellular Gd concentration in the range from 0.2 to 5.5 μM.
    Conclusions: This study confirms the ex vivo uptake of GBCA by WBCs and provides the first evidence that GBCA is indeed taken up by WBCs in vivo by patients undergoing ce-MRI examination. However, the observed Gd uptake in WBCs does not follow a log-normal distribution commonly observed in the fields of environmental studies, biology, and medicine. Whether cellular uptake of GBCA is linked to the observed deposition of Gd remains unclear. Therefore, studying the interaction between GBCA and human cells may clarify crucial questions about the effects of Gd on patients after MRI examinations.
    MeSH term(s) Male ; Animals ; Humans ; Female ; Adult ; Middle Aged ; Aged ; Aged, 80 and over ; Contrast Media/adverse effects ; Gadolinium/adverse effects ; Gadolinium DTPA ; Models, Animal ; Organometallic Compounds/adverse effects ; Erythrocytes ; Brain ; Magnetic Resonance Imaging/methods ; Heterocyclic Compounds
    Chemical Substances Contrast Media ; gadolinium 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetate (99J2XUF1JT) ; Gadolinium (AU0V1LM3JT) ; Gadolinium DTPA (K2I13DR72L) ; Organometallic Compounds ; Heterocyclic Compounds
    Language English
    Publishing date 2023-10-13
    Publishing country United States
    Document type Journal Article
    ZDB-ID 80345-5
    ISSN 1536-0210 ; 0020-9996
    ISSN (online) 1536-0210
    ISSN 0020-9996
    DOI 10.1097/RLI.0000000000001029
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Late Maturation Steps Preceding Selective Nuclear Export and Egress of Progeny Parvovirus.

    Wolfisberg, Raphael / Kempf, Christoph / Ros, Carlos

    Journal of virology

    2016  Volume 90, Issue 11, Page(s) 5462–5474

    Abstract: Unlabelled: Although the mechanism is not well understood, growing evidence indicates that the nonenveloped parvovirus minute virus of mice (MVM) may actively egress before passive release through cell lysis. We have dissected the late maturation steps ... ...

    Abstract Unlabelled: Although the mechanism is not well understood, growing evidence indicates that the nonenveloped parvovirus minute virus of mice (MVM) may actively egress before passive release through cell lysis. We have dissected the late maturation steps of the intranuclear progeny with the aims of confirming the existence of active prelytic egress and identifying critical capsid rearrangements required to initiate the process. By performing anion-exchange chromatography (AEX), we separated intranuclear progeny particles by their net surface charges. Apart from empty capsids (EC), two distinct populations of full capsids (FC) arose in the nuclei of infected cells. The earliest population of FC to appear was infectious but, like EC, could not be actively exported from the nucleus. Further maturation of this early population, involving the phosphorylation of surface residues, gave rise to a second, late population with nuclear export potential. While capsid surface phosphorylation was strictly associated with nuclear export capacity, mutational analysis revealed that the phosphoserine-rich N terminus of VP2 (N-VP2) was dispensable, although it contributed to passive release. The reverse situation was observed for the incoming particles, which were dephosphorylated in the endosomes. Our results confirm the existence of active prelytic egress and reveal a late phosphorylation event occurring in the nucleus as a selective factor for initiating the process.
    Importance: In general, the process of egress of enveloped viruses is active and involves host cell membranes. However, the release of nonenveloped viruses seems to rely more on cell lysis. At least for some nonenveloped viruses, an active process before passive release by cell lysis has been reported, although the underlying mechanism remains poorly understood. By using the nonenveloped model parvovirus minute virus of mice, we could confirm the existence of an active process of nuclear export and further characterize the associated capsid maturation steps. Following DNA packaging in the nucleus, capsids required further modifications, involving the phosphorylation of surface residues, to acquire nuclear export potential. Inversely, those surface residues were dephosphorylated on entering capsids. These spatially controlled phosphorylation-dephosphorylation events concurred with the nuclear export-import potential required to complete the infectious cycle.
    MeSH term(s) Active Transport, Cell Nucleus ; Animals ; Capsid ; Cell Line ; Cell Nucleus/metabolism ; Cell Nucleus/virology ; Fibroblasts/virology ; Humans ; Mice ; Minute Virus of Mice/genetics ; Minute Virus of Mice/physiology ; Minute Virus of Mice/ultrastructure ; Mutation ; Parvoviridae Infections/virology ; Phosphorylation ; Virion/physiology ; Virus Assembly ; Virus Release ; Virus Replication
    Language English
    Publishing date 2016-06-01
    Publishing country United States
    Document type Journal Article
    ZDB-ID 80174-4
    ISSN 1098-5514 ; 0022-538X
    ISSN (online) 1098-5514
    ISSN 0022-538X
    DOI 10.1128/JVI.02967-15
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: Generation of Stable cisPt Resistant Lung Adenocarcinoma Cells.

    Ruprecht, Nico / Hofmann, Lukas / Hungerbühler, Martin Nils / Kempf, Christoph / Heverhagen, Johannes Thomas / von Tengg-Kobligk, Hendrik

    Pharmaceuticals (Basel, Switzerland)

    2020  Volume 13, Issue 6

    Abstract: Platinum compounds represent the backbone of combined chemotherapy protocols for advanced lung cancer. The mechanisms responsible for its frequent primary or acquired resistance to cisplatin (cisPt)-based chemotherapy remains enigmatic. The availability ... ...

    Abstract Platinum compounds represent the backbone of combined chemotherapy protocols for advanced lung cancer. The mechanisms responsible for its frequent primary or acquired resistance to cisplatin (cisPt)-based chemotherapy remains enigmatic. The availability of two cell lines of the same origin, one resistant and the other sensitive, will facilitate research to reveal the mechanism of resistance formation. Lung adenocarcinoma cells, A240286S (A24), were cultivated in increasing cisPt concentrations over a prolonged time. After a significant increase in IC
    Language English
    Publishing date 2020-05-29
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2193542-7
    ISSN 1424-8247
    ISSN 1424-8247
    DOI 10.3390/ph13060109
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: The VP1u Receptor Restricts Parvovirus B19 Uptake to Permissive Erythroid Cells.

    Leisi, Remo / Von Nordheim, Marcus / Ros, Carlos / Kempf, Christoph

    Viruses

    2016  Volume 8, Issue 10

    Abstract: Parvovirus B19 (B19V) is a small non-enveloped virus and known as the causative agent for the mild childhood ... ...

    Abstract Parvovirus B19 (B19V) is a small non-enveloped virus and known as the causative agent for the mild childhood disease
    Language English
    Publishing date 2016-09-28
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2516098-9
    ISSN 1999-4915 ; 1999-4915
    ISSN (online) 1999-4915
    ISSN 1999-4915
    DOI 10.3390/v8100265
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: The Receptor-Binding Domain in the VP1u Region of Parvovirus B19.

    Leisi, Remo / Di Tommaso, Chiarina / Kempf, Christoph / Ros, Carlos

    Viruses

    2016  Volume 8, Issue 3, Page(s) 61

    Abstract: Parvovirus B19 (B19V) is known as the human pathogen causing the mild childhood disease erythema infectiosum. B19V shows an extraordinary narrow tissue tropism for erythroid progenitor cells in the bone marrow, which is determined by a highly restricted ... ...

    Abstract Parvovirus B19 (B19V) is known as the human pathogen causing the mild childhood disease erythema infectiosum. B19V shows an extraordinary narrow tissue tropism for erythroid progenitor cells in the bone marrow, which is determined by a highly restricted uptake. We have previously shown that the specific internalization is mediated by the interaction of the viral protein 1 unique region (VP1u) with a yet unknown cellular receptor. To locate the receptor-binding domain (RBD) within the VP1u, we analyzed the effect of truncations and mutations on the internalization capacity of the recombinant protein into UT7/Epo cells. Here we report that the N-terminal amino acids 5-80 of the VP1u are necessary and sufficient for cellular binding and internalization; thus, this N-terminal region represents the RBD required for B19V uptake. Using site-directed mutagenesis, we further identified a cluster of important amino acids playing a critical role in VP1u internalization. In silico predictions and experimental results suggest that the RBD is structured as a rigid fold of three α-helices. Finally, we found that dimerization of the VP1u leads to a considerably enhanced cellular binding and internalization. Taken together, we identified the RBD that mediates B19V uptake and mapped functional and structural motifs within this sequence. The findings reveal insights into the uptake process of B19V, which contribute to understand the pathogenesis of the infection and the neutralization of the virus by the immune system.
    MeSH term(s) Capsid Proteins/genetics ; Capsid Proteins/metabolism ; Cell Line ; DNA Mutational Analysis ; Humans ; Mutagenesis, Site-Directed ; Mutant Proteins/genetics ; Mutant Proteins/metabolism ; Mutation ; Parvovirus B19, Human/genetics ; Parvovirus B19, Human/physiology ; Protein Multimerization ; Protein Structure, Tertiary ; Receptors, Virus/metabolism ; Sequence Deletion ; Virus Internalization
    Chemical Substances Capsid Proteins ; Mutant Proteins ; Receptors, Virus ; capsid protein VP1, parvovirus B19
    Language English
    Publishing date 2016-02-24
    Publishing country Switzerland
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2516098-9
    ISSN 1999-4915 ; 1999-4915
    ISSN (online) 1999-4915
    ISSN 1999-4915
    DOI 10.3390/v8030061
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Specific Targeting of Proerythroblasts and Erythroleukemic Cells by the VP1u Region of Parvovirus B19.

    Leisi, Remo / von Nordheim, Marcus / Kempf, Christoph / Ros, Carlos

    Bioconjugate chemistry

    2015  Volume 26, Issue 9, Page(s) 1923–1930

    Abstract: Viruses are evolutionarily developed cell-entering nanomachines, which are frequently used as gene or drug delivery systems. Parvovirus B19 (B19V) shows a remarkably restricted tropism for erythropoietin-dependent erythroid differentiation stages, and ... ...

    Abstract Viruses are evolutionarily developed cell-entering nanomachines, which are frequently used as gene or drug delivery systems. Parvovirus B19 (B19V) shows a remarkably restricted tropism for erythropoietin-dependent erythroid differentiation stages, and thus this virus provides an opportunity to deliver cargo to these intermediate differentiated cells. Here we report the construction of a delivery system from B19V subunits that maintains the highly selective cell-entry of the native virus and offers versatile cargo transport. To obtain this specific carrier, we conjugated the cell-targeting VP1u region of B19V to NeutrAvidin as a loading platform for biotinylated cargos. The VP1u-NeutrAvidin conjugate delivered fluorophores, DNA, and toxic payloads specifically to erythroid cells around the proerythroblast differentiation stage, including erythroleukemic cells. The VP1u-NeutrAvidin represents a unique cell surface marker which exclusively detects intermediate erythroid differentiation stages. Furthermore, the cell-entering property of this viral-based targeting system offers opportunities for erythroid-specific drug delivery or gene therapy.
    MeSH term(s) Avidin/metabolism ; Biological Transport ; Capsid Proteins/chemistry ; Capsid Proteins/metabolism ; Cell Line, Tumor ; Drug Carriers/chemistry ; Drug Carriers/metabolism ; Erythroblasts/metabolism ; Humans ; Leukemia, Erythroblastic, Acute/pathology ; Models, Molecular ; Oligonucleotides/metabolism ; Parvovirus B19, Human ; Protein Conformation
    Chemical Substances Capsid Proteins ; Drug Carriers ; Oligonucleotides ; capsid protein VP1, parvovirus B19 ; neutravidin ; Avidin (1405-69-2)
    Language English
    Publishing date 2015-09-16
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1024041-x
    ISSN 1520-4812 ; 1043-1802
    ISSN (online) 1520-4812
    ISSN 1043-1802
    DOI 10.1021/acs.bioconjchem.5b00321
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Beyond Single-Cell Analysis of Metallodrugs by ICP-MS: Targeting Cellular Substructures.

    Galé, Audrey / Hofmann, Lukas / Lüdi, Nicola / Hungerbühler, Martin Nils / Kempf, Christoph / Heverhagen, Johannes Thomas / von Tengg-Kobligk, Hendrik / Broekmann, Peter / Ruprecht, Nico

    International journal of molecular sciences

    2021  Volume 22, Issue 17

    Abstract: Platinum compounds such as cisplatin (cisPt) embody the backbone of combination chemotherapy protocols against advanced lung cancer. However, their efficacy is primarily limited by inherent or acquired platinum resistance, the origin of which has not ... ...

    Abstract Platinum compounds such as cisplatin (cisPt) embody the backbone of combination chemotherapy protocols against advanced lung cancer. However, their efficacy is primarily limited by inherent or acquired platinum resistance, the origin of which has not been fully elucidated yet, although of paramount interest. Using single cell inductively coupled plasma mass spectrometry (SC-ICP-MS), this study quantifies cisPt in single cancer cells and for the first time in isolated nuclei. A comparison of cisPt uptake was performed between a wild type (wt) cancer cell line and related resistant sublines. In both, resistant cells, wt cells, and their nuclei, cisPt uptake was measured at different incubation times. A lower amount of cisPt was found in resistant cell lines and their nuclei compared to wt cells. Moreover, the abundance of internalized cisPt decreased with increasing resistance. Interestingly, concentrations of cisPt found within the nuclei were higher than compared to cellular concentrations. Here, we show, that SC-ICP-MS allows precise and accurate quantification of metallodrugs in both single cells and cell organelles such as nuclei. These findings pave the way for future applications investigating the potency and efficacy of novel metallodrugs developed for cancer treatment.
    MeSH term(s) Antineoplastic Agents/chemistry ; Antineoplastic Agents/pharmacology ; Cell Line, Tumor ; Cisplatin/metabolism ; Cisplatin/pharmacology ; Drug Resistance, Neoplasm/drug effects ; Drug Resistance, Neoplasm/genetics ; Drug Resistance, Neoplasm/physiology ; Humans ; Lung Neoplasms/drug therapy ; Mass Spectrometry/methods ; Neoplasms/drug therapy ; Single-Cell Analysis/methods ; Spectrum Analysis
    Chemical Substances Antineoplastic Agents ; Cisplatin (Q20Q21Q62J)
    Language English
    Publishing date 2021-08-31
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2019364-6
    ISSN 1422-0067 ; 1422-0067 ; 1661-6596
    ISSN (online) 1422-0067
    ISSN 1422-0067 ; 1661-6596
    DOI 10.3390/ijms22179468
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Parvovirus B19 uptake is a highly selective process controlled by VP1u, a novel determinant of viral tropism.

    Leisi, Remo / Ruprecht, Nico / Kempf, Christoph / Ros, Carlos

    Journal of virology

    2013  Volume 87, Issue 24, Page(s) 13161–13167

    Abstract: The VP1 unique region (VP1u) of human parvovirus B19 (B19V) is the immunodominant part of the viral capsid. Originally inaccessible, the VP1u becomes exposed upon primary attachment to the globoside receptor. To study the function of the exposed VP1u in ... ...

    Abstract The VP1 unique region (VP1u) of human parvovirus B19 (B19V) is the immunodominant part of the viral capsid. Originally inaccessible, the VP1u becomes exposed upon primary attachment to the globoside receptor. To study the function of the exposed VP1u in B19V uptake, we expressed this region as a recombinant protein. Here, we report that purified recombinant VP1u binds and is internalized in UT7/Epo cells. By means of truncations and specific antibodies, we identified the most N-terminal amino acid residues of VP1u as the essential region for binding and internalization. Furthermore, the recombinant VP1u was able to block B19V uptake, suggesting that the protein and the virus undertake the same internalization pathway. Assays with different erythroid and nonerythroid cell lines showed that the N-terminal VP1u binding was restricted to a few cell lines of the erythroid lineage, which were also the only cells that allowed B19V internalization and infection. These results together indicate that the N-terminal region of VP1u is responsible for the internalization of the virus and that the interacting receptor is restricted to B19V-susceptible cells. The highly selective uptake mechanism represents a novel determinant of the tropism and pathogenesis of B19V.
    MeSH term(s) Amino Acid Motifs ; Capsid Proteins/chemistry ; Capsid Proteins/genetics ; Capsid Proteins/metabolism ; Cell Line ; Humans ; Parvoviridae Infections/virology ; Parvovirus B19, Human/chemistry ; Parvovirus B19, Human/genetics ; Parvovirus B19, Human/physiology ; Viral Tropism ; Virus Internalization
    Chemical Substances Capsid Proteins
    Language English
    Publishing date 2013-09-25
    Publishing country United States
    Document type Journal Article
    ZDB-ID 80174-4
    ISSN 1098-5514 ; 0022-538X
    ISSN (online) 1098-5514
    ISSN 0022-538X
    DOI 10.1128/JVI.02548-13
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Impaired genome encapsidation restricts the in vitro propagation of human parvovirus B19.

    Wolfisberg, Raphael / Ruprecht, Nico / Kempf, Christoph / Ros, Carlos

    Journal of virological methods

    2013  Volume 193, Issue 1, Page(s) 215–225

    Abstract: The lack of a permissive cell culture system hampers the study of human parvovirus B19 (B19V). UT7/Epo is one of the few established cell lines that can be infected with B19V but generates none or few infectious progeny. Recently, hypoxic conditions or ... ...

    Abstract The lack of a permissive cell culture system hampers the study of human parvovirus B19 (B19V). UT7/Epo is one of the few established cell lines that can be infected with B19V but generates none or few infectious progeny. Recently, hypoxic conditions or the use of primary CD36+ erythroid progenitor cells (CD36+ EPCs) have been shown to improve the infection. These novel approaches were evaluated in infection and transfection experiments. Hypoxic conditions or the use of CD36+ EPCs resulted in a significant acceleration of the infection/transfection and a modest increase in the yield of capsid progeny. However, under all tested conditions, genome encapsidation was impaired seriously. Further analysis of the cell culture virus progeny revealed that differently to the wild-type virus, the VP1 unique region (VP1u) was exposed partially and was unable to become further externalized upon heat treatment. The fivefold axes pore, which is used for VP1u externalization and genome encapsidation, might be constricted by the atypical VP1u conformation explaining the packaging failure. Although CD36+ EPCs and hypoxia facilitate B19V infection, large quantities of infectious progeny cannot be generated due to a failure in genome encapsidation, which arises as a major limiting factor for the in vitro propagation of B19V.
    MeSH term(s) CD36 Antigens/metabolism ; Cell Line ; Erythroid Precursor Cells/virology ; Humans ; Oxygen/metabolism ; Parvovirus B19, Human/physiology ; Virus Assembly ; Virus Cultivation/methods ; Virus Replication
    Chemical Substances CD36 Antigens ; Oxygen (S88TT14065)
    Language English
    Publishing date 2013-10
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 8013-5
    ISSN 1879-0984 ; 0166-0934
    ISSN (online) 1879-0984
    ISSN 0166-0934
    DOI 10.1016/j.jviromet.2013.06.003
    Database MEDical Literature Analysis and Retrieval System OnLINE

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