TY  - JOUR
A1  - Schmitz, Werner
A1  - Ries, Elena
A1  - Koderer, Corinna
A1  - Völter, Maximilian Friedrich
A1  - Wünsch, Anna Chiara
A1  - El-Mesery, Mohamed
A1  - Frackmann, Kyra
A1  - Kübler, Alexander Christian
A1  - Linz, Christian
A1  - Seher, Axel
T1  - Cysteine restriction in murine L929 fibroblasts as an alternative strategy to methionine restriction in cancer therapy
JF  - International Journal of Molecular Sciences
N2  - Methionine restriction (MetR) is an efficient method of amino acid restriction (AR) in cells and organisms that induces low energy metabolism (LEM) similar to caloric restriction (CR). The implementation of MetR as a therapy for cancer or other diseases is not simple since the elimination of a single amino acid in the diet is difficult. However, the in vivo turnover rate of cysteine is usually higher than the rate of intake through food. For this reason, every cell can enzymatically synthesize cysteine from methionine, which enables the use of specific enzymatic inhibitors. In this work, we analysed the potential of cysteine restriction (CysR) in the murine cell line L929. This study determined metabolic fingerprints using mass spectrometry (LC/MS). The profiles were compared with profiles created in an earlier work under MetR. The study was supplemented by proliferation studies using D-amino acid analogues and inhibitors of intracellular cysteine synthesis. CysR showed a proliferation inhibition potential comparable to that of MetR. However, the metabolic footprints differed significantly and showed that CysR does not induce classic LEM at the metabolic level. Nevertheless, CysR offers great potential as an alternative for decisive interventions in general and tumour metabolism at the metabolic level.
KW  - methionine restriction
KW  - cysteine restriction
KW  - mass spectrometry
KW  - LC/MS
KW  - cancer therapy
KW  - caloric restriction
KW  - homocysteine
KW  - amino acid analogues
KW  - cysteine synthase inhibitor
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265486
SN  - 1422-0067
VL  - 22
IS  - 21
ER  - 
TY  - THES
A1  - Fink, Kristin
T1  - Toxins in Renal Disease and Dialysis Therapy : Genotoxic Potential and Mechanisms
T1  - Toxine in Nierenerkrankung und Dialyse Therapie : Genotoxisches Potential und Mechanismus
N2  - In patients suffering from end-stage renal disease who are treated by hemodialysis genomic damage as well as cancer incidence is elevated. One possible cause for the increased genomic damage could be the accumulation of genotoxic substances in the blood of patients. Two possible sources for those toxins have to be considered. The first possibility is that substances from dialysers, the blood tubing system or even contaminated dialysis solutions may leach into the blood of the patients during dialysis. Secondly, the loss of renal filtration leads to an accumulation of substances which are normally excreted by the kidney. If those substances possess toxic potential, they are called uremic toxins. Several of these uremic toxins are potentially genotoxic. Within this thesis several exemplary uremic toxins have been tested for genotoxic effects (homocysteine, homocysteine-thiolactone,leptine, advanced glycated end-products). Additionally, it was analysed whether substances are leaching from dialysers or blood tubing and whether they cause effects in in vitrotoxicity testing. The focus of chemical analytisis was on bisphenol A (BPA), the main component of plastics used in dialysers and dialyser membranes.
N2  - Patienten, die an terminaler Niereninsuffizienz leiden und mittels Hämodialyse behandelt werden, weisen einen erhöhten Genomschaden auf. Dieser könnte ursächlich für die erhöhte Krebsinzidenz dieser Patientengruppe sein. Eine der möglichen Ursachen für den erhöhten Genomschaden stellt die Akkumulation genotoxischer Substanzen im Blut der Patienten dar. Diese Substanzen können prinzipiell aus zwei unterschiedlichen Quellen stammen. Erstens besteht die Möglichkeit, dass während der Dialyse Substanzen aus den Dialysatoren, dem Blutschlauchsystem oder gar aus verunreinigtem Dialysat in das Blut der Patienten übertreten. Zweitens führt der Verlust der Nierenfunktion zu einer stark verminderten Exkretion harnpflichtiger Substanzen. Diese Substanzen akkumulieren im Blut und bilden, sofern sie ein toxisches Potential besitzen, die Gruppe der so genannten urämischen Toxine. Einige dieser urämischen Toxine sind potentiell auch genotoxisch. Im Rahmen der vorliegenden Dissertation wurden exemplarische Vertreter der urämischen Toxine auf ihre genotoxische Wirkung hin untersucht (Homocstein, Homocystein-Thiolacton, Leptin, Advanced Glycation End-Products). Außerdem wurde analysiert, ob Substanzen aus Dialysatormembranen oder dem Blutschlauchsystem austreten und in in vitro-Toxizitätstests Effekte zeigen. Der Fokus der Analytik lag hierbei auf dem Nachweis von Bisphenol A, dem Hauptbestandteil verschiedener Kunststoffe die für Dialysatoren und Dialysatormembranen verwendet werden.
KW  - Bisphenol A
KW  - Homocystein
KW  - Extrakorporale Dialyse
KW  - Genomschaden
KW  - Urämische Toxine
KW  - bisphenol a
KW  - homocysteine
KW  - dialysis
KW  - genomic damage
KW  - uremic toxins
Y1  - 2008
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31082
ER  -