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result(s) for
"Wehe, A."
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Modulating the Activity of the Human Organic Cation Transporter 2 Emerges as a Potential Strategy to Mitigate Unwanted Toxicities Associated with Cisplatin Chemotherapy
by
Hucke, Anna
,
Karst, Uwe
,
Ciarimboli, Giuliano
in
Animals
,
Calmodulin
,
Calmodulin - metabolism
2024
Cisplatin (CDDP) stands out as an effective chemotherapeutic agent; however, its application is linked to the development of significant adverse effects, notably nephro- and ototoxicity. The human organic cation transporter 2 (hOCT2), found in abundance in the basolateral membrane domain of renal proximal tubules and the Corti organ, plays a crucial role in the initiation of nephro- and ototoxicity associated with CDDP by facilitating its uptake in kidney and ear cells. Given its limited presence in cancer cells, hOCT2 emerges as a potential druggable target for mitigating unwanted toxicities associated with CDDP. Potential strategies for mitigating CDDP toxicities include competing with the uptake of CDDP by hOCT2 or inhibiting hOCT2 activity through rapid regulation mediated by specific signaling pathways. This study investigated the interaction between the already approved cationic drugs disopyramide, imipramine, and orphenadrine with hOCT2 that is stably expressed in human embryonic kidney cells. Regarding disopyramide, its influence on CDDP cellular transport by hOCT2 was further characterized through inductively coupled plasma isotope dilution mass spectrometry. Additionally, its potential protective effects against cellular toxicity induced by CDDP were assessed using a cytotoxicity test. Given that hOCT2 is typically expressed in the basolateral membrane of polarized cells, with specific regulatory mechanisms, this work studied the regulation of hOCT2 that is stably expressed in Madin–Darby Canine Kidney (MDCK) cells. These cells were cultured in a matrix to induce the formation of cysts, exposing hOCT2 in the basolateral plasma membrane domain, which was freely accessible to experimental solutions. The study specifically tested the regulation of ASP+ uptake by hOCT2 in MDCK cysts through the inhibition of casein kinase II (CKII), calmodulin, or p56lck tyrosine kinase. Furthermore, the impact of this manipulation on the cellular toxicity induced by CDDP was examined using a cytotoxicity test. All three drugs—disopyramide, imipramine, and orphenadrine—demonstrated inhibition of ASP+ uptake, with IC50 values in the micromolar (µM) range. Notably, disopyramide produced a significant reduction in the CDDP cellular toxicity and platinum cellular accumulation when co-incubated with CDDP. The activity of hOCT2 in MDCK cysts experienced a significant down-regulation under inhibition of CKII, calmodulin, or p56lck tyrosine kinase. Interestingly, only the inhibition of p56lck tyrosine kinase demonstrated the capability to protect the cells against CDDP toxicity. In conclusion, certain interventions targeting hOCT2 have demonstrated the ability to reduce CDDP cytotoxicity, at least in vitro. Further investigations in in vivo systems are warranted to ascertain their potential applicability as co-treatments for mitigating undesired toxicities associated with CDDP in patients.
Journal Article
The interaction of platinum-based drugs with native biologically relevant proteins
by
Lanvers-Kaminsky, Claudia
,
Karst, Uwe
,
Kieshauer, Michael
in
Affinity
,
Ammonia
,
Analytical Chemistry
2013
This study focuses on the identification of the products that are formed upon binding of therapeutically relevant platinum complexes to proteins like β-lactoglobulin A (LGA), human serum albumin (HSA), or human hemoglobin (HB). The respective proteins were incubated with the platinum-based anticancer drugs cisplatin, carboplatin, and oxaliplatin. LGA was selected as the model protein in addition to the two most abundant blood proteins HSA and HB. In case of the model protein, the effect of free thiol groups on the affinity of cisplatin, carboplatin, and oxaliplatin was investigated by means of liquid chromatography electrospray ionization time-of-flight mass spectrometry (LC/ESI-ToF-MS). The reduced form of LGA, which contains four free thiol groups more than the native LGA, shows a much higher affinity to the platinum-based drugs. By means of liquid chromatography coupled to inductively coupled plasma mass spectrometry, the reaction behavior of the platinum-based drugs towards HSA and HB was investigated under different conditions considering the chloride concentration (4 or 100 mM) and the incubation time (24 and 48 h). In case of carboplatin, less than 6 % protein-bound platinum was detected. However, both cisplatin and oxaliplatin display a high affinity to the proteins investigated. Further information was obtained by means of LC/ESI-ToF-MS. In case of oxaliplatin, the complex [Pt(DACH)]
2+
(DACH = C
6
N
2
H
14
) was identified interacting with HSA and HB. For cisplatin, different results were observed for the two proteins. The complex [Pt(NH
3
)
2
Cl]
+
interacted predominantly with HSA and [Pt(NH
3
)
2
]
2+
with HB.
Figure
Journal Article
Elemental Bioimaging by Means of Fast Scanning Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry
by
Karst, Uwe
,
Ciarimboli, Giuliano
,
Sperling, Michael
in
Analytical Chemistry
,
Animals
,
Bioinformatics
2015
One of the most common setups for elemental bioimaging, the hyphenation of a laser ablation (LA) system and an inductively coupled plasma mass spectrometer (ICP-MS), was expanded by adding full scan mass spectrometric information as another dimension of information. While most studies deal with the analysis of typically not more than up to 10 isotopes per scan cycle, a fast scanning quadrupole mass analyzer was utilized to record the full mass spectrum of interest in this work. Mass-to-charge ratios from 6 to 250 were observed within one cycle. Besides the x- and y-position on the ablated sample and the intensity, the
m/z
-ratio served as fourth variable for each pixel of the obtained data, closing thereby the gap between “inorganic” and “organic” mass spectrometric imaging techniques. The benefits of this approach include an improved control of interferences, the discovery of unexpected elemental distributions, the possibility to plot isotopic ratios, and to integrate the intensities of a certain number of mass channels recorded for each isotope, thus virtually increasing sensitivity. The respective data are presented for dried droplets as well as embedded animal and human tissue slices. Limits of detection were calculated and found to be in accordance with counting statistics. A dedicated software macro was developed for data manipulation prior to common evaluation and image creation.
Graphical Abstract
ᅟ
Journal Article
On-line species-unspecific isotope dilution analysis in the picomolar range reveals the time- and species-depending mercury uptake in human astrocytes
2014
In order to reveal the time-depending mercury species uptake by human astrocytes, a novel approach for total mercury analysis is presented, which uses an accelerated sample introduction system combined on-line with an inductively coupled plasma mass spectrometer equipped with a collision/reaction cell. Human astrocyte samples were incubated with inorganic mercury (HgCl
2
), methylmercury chloride (MeHgCl), and thimerosal. After 1-h incubation with Hg
2+
, cellular concentrations of 3 μM were obtained, whereas for organic species, concentrations of 14–18 μM could be found. After 24 h, a cellular accumulation factor of 0.3 was observed for the cells incubated with Hg
2+
, whereas the organic species both showed values of about 5. Due to the obtained steady-state signals, reliable results with relative standard deviations of well below 5 % and limits of detection in the concentration range of 1 ng L
−1
were obtained using external calibration and species-unspecific isotope dilution analysis approaches. The results were further validated using atomic fluorescence spectrometry.
Figure
ᅟ
Journal Article
Measurement of charged hadron multiplicity in Au+Au collisions at sNN= 200 GeV with the sPHENIX detector
by
Bernauer, J. C.
,
Croft, E.
,
Schaefer, B.
in
Charged particles
,
Classical and Quantum Gravitation
,
Collaboration
2025
A
bstract
The pseudorapidity distribution of charged hadrons produced in Au+Au collisions at a center-of-mass energy of
s
NN
= 200 GeV is measured using data collected by the sPHENIX detector. Charged hadron yields are extracted by counting cluster pairs in the inner and outer layers of the Intermediate Silicon Tracker, with corrections applied for detector acceptance, reconstruction efficiency, combinatorial pairs, and contributions from secondary decays. The measured distributions cover |
η
|
<
1
.
1 across various centralities, and the average pseudorapidity density of charged hadrons at mid-rapidity is compared to predictions from Monte Carlo heavy-ion event generators. This result, featuring full azimuthal coverage at mid-rapidity, is consistent with previous experimental measurements at the Relativistic Heavy Ion Collider, thereby supporting the broader sPHENIX physics program.
Journal Article
Measurement of charged hadron multiplicity in Au+Au collisions at$\\sqrt{{\\textrm{s}}_{\\textrm{NN}}}$= 200 GeV with the sPHENIX detector
by
Bernauer, J. C.
,
Croft, E.
,
Schaefer, B.
in
Heavy Ion Experiments
,
Heavy-Ion Collision
,
Quark Gluon Plasma
2025
The pseudorapidity distribution of charged hadrons produced in Au+Au collisions at a center-of-mass energy of $\\sqrt{{\\textrm{s}}_{\\textrm{NN}}}$ = 200 GeV is measured using data collected by the sPHENIX detector. Charged hadron yields are extracted by counting cluster pairs in the inner and outer layers of the Intermediate Silicon Tracker, with corrections applied for detector acceptance, reconstruction efficiency, combinatorial pairs, and contributions from secondary decays. The measured distributions cover |η| < 1.1 across various centralities, and the average pseudorapidity density of charged hadrons at mid-rapidity is compared to predictions from Monte Carlo heavy-ion event generators. This result, featuring full azimuthal coverage at mid-rapidity, is consistent with previous experimental measurements at the Relativistic Heavy Ion Collider, thereby supporting the broader sPHENIX physics program.
Journal Article
Measurement of charged hadron multiplicity in Au+Au collisions at$\\sqrt{{\\textrm{s}}_{\\textrm{NN}}}$= 200 GeV with the sPHENIX detector
by
Bernauer, J. C.
,
Croft, E.
,
Schaefer, B.
in
heavy ion experiments
,
heavy-ion collision
,
quark gluon plasma
2025
The pseudorapidity distribution of charged hadrons produced in Au+Au collisions at a center-of-mass energy of $\\sqrt{{\\textrm{s}}_{\\textrm{NN}}}$ = 200 GeV is measured using data collected by the sPHENIX detector. Charged hadron yields are extracted by counting cluster pairs in the inner and outer layers of the Intermediate Silicon Tracker, with corrections applied for detector acceptance, reconstruction efficiency, combinatorial pairs, and contributions from secondary decays. The measured distributions cover |η| < 1.1 across various centralities, and the average pseudorapidity density of charged hadrons at mid-rapidity is compared to predictions from Monte Carlo heavy-ion event generators. This result, featuring full azimuthal coverage at mid-rapidity, is consistent with previous experimental measurements at the Relativistic Heavy Ion Collider, thereby supporting the broader sPHENIX physics program.
Journal Article
Measurement of charged hadron multiplicity in Au+Au collisions at$$ \\sqrt{{\\textrm{s}}_{\\textrm{NN}}} $$= 200 GeV with the sPHENIX detector
by
Bernauer, J. C.
,
Croft, E.
,
Schaefer, B.
in
Heavy Ion Experiments
,
Heavy-Ion Collision
,
Quark Gluon Plasma
2025
The pseudorapidity distribution of charged hadrons produced in Au+Au collisions at a center-of-mass energy of$$ \\sqrt{{\\textrm{s}}_{\\textrm{NN}}} $$s NN = 200 GeV is measured using data collected by the sPHENIX detector. Charged hadron yields are extracted by counting cluster pairs in the inner and outer layers of the Intermediate Silicon Tracker, with corrections applied for detector acceptance, reconstruction efficiency, combinatorial pairs, and contributions from secondary decays. The measured distributions cover | η | < 1 . 1 across various centralities, and the average pseudorapidity density of charged hadrons at mid-rapidity is compared to predictions from Monte Carlo heavy-ion event generators. This result, featuring full azimuthal coverage at mid-rapidity, is consistent with previous experimental measurements at the Relativistic Heavy Ion Collider, thereby supporting the broader sPHENIX physics program.
Journal Article
Measurement of charged hadron multiplicity in Au + Au collisions at√s̅_̅(̅N̅N̅)̅= 200 GeV with the sPHENIX detector
by
Bernauer, J. C.
,
Croft, E.
,
Schaefer, B.
in
Heavy Ion Experiments
,
Heavy-Ion Collision
,
NUCLEAR PHYSICS AND RADIATION PHYSICS
2025
The pseudorapidity distribution of charged hadrons produced in Au + Au collisions at a center-of-mass energy of √s̅_̅(̅N̅N̅)̅ = 200 GeV is measured using data collected by the sPHENIX detector. Charged hadron yields are extracted by counting cluster pairs in the inner and outer layers of the Intermediate Silicon Tracker, with corrections applied for detector acceptance, reconstruction efficiency, combinatorial pairs, and contributions from secondary decays. The measured distributions cover |η| < 1.1 across various centralities, and the average pseudorapidity density of charged hadrons at mid-rapidity is compared to predictions from Monte Carlo heavy-ion event generators. This result, featuring full azimuthal coverage at mid-rapidity, is consistent with previous experimental measurements at the Relativistic Heavy Ion Collider, thereby supporting the broader sPHENIX physics program.
Journal Article
Measurement of charged hadron multiplicity in Au+Au collisions at s NN$$ \\sqrt{{\\textrm{s}}_{\\textrm{NN}}} $$= 200 GeV with the sPHENIX detector
by
H. Pereira Da Costa
,
W. Goodman
,
M. S. Khan
in
Heavy Ion Experiments
,
Heavy-Ion Collision
,
Quark Gluon Plasma
2025
Abstract The pseudorapidity distribution of charged hadrons produced in Au+Au collisions at a center-of-mass energy of s NN$$ \\sqrt{{\\textrm{s}}_{\\textrm{NN}}} $$= 200 GeV is measured using data collected by the sPHENIX detector. Charged hadron yields are extracted by counting cluster pairs in the inner and outer layers of the Intermediate Silicon Tracker, with corrections applied for detector acceptance, reconstruction efficiency, combinatorial pairs, and contributions from secondary decays. The measured distributions cover |η| < 1.1 across various centralities, and the average pseudorapidity density of charged hadrons at mid-rapidity is compared to predictions from Monte Carlo heavy-ion event generators. This result, featuring full azimuthal coverage at mid-rapidity, is consistent with previous experimental measurements at the Relativistic Heavy Ion Collider, thereby supporting the broader sPHENIX physics program.
Journal Article