Previous studies in our laboratory reported L-malate as a free radical scavenger in aged rats. To investigate the antioxidant mechanism of L-malate in the mitochondria, we analyzed the change in gene expression of two malate-aspartate shuttle (MAS)-related carried proteins (AGC, aspartate/glutamate carrier and OMC, oxoglutarate/malate carrier) in the inner mitochondrial membrane, and three antioxidant enzymes (CAT, SOD, and GSH-Px) in the mitochondria. The changes in gene expression of these proteins and enzymes were examined by real-time RT-PCR in the heart and liver of aged rats treated with L-malate. L-malate was orally administered in rats continuously for 30 days using a feeding atraumatic needle. We found that the gene expression of OMC and GSH-Px mRNA in the liver increased by 39 % and 38 %, respectively, in the 0.630 g/kg L-malate treatment group than that in the control group. The expression levels of SOD mRNA in the liver increased by 39 %, 56 %, and 78 % in the 0.105, 0.210, and 0.630 g/kg L-malate treatment groups, respectively. No difference were observed in the expression levels of AGC, OMC, CAT, SOD, and GSH-Px mRNAs in the heart of rats between the L-malate treatment and control groups. These results predicted that L-malate may increase the antioxidant capacity of mitochondria by enhancing the expression of mRNAs involved in the MAS and the antioxidant enzymes.
- MeSH
- antioxidancia metabolismus farmakologie MeSH
- antiportéry účinky léků metabolismus MeSH
- enzymy genetika metabolismus MeSH
- glutathionperoxidasa metabolismus MeSH
- jaterní mitochondrie účinky léků enzymologie MeSH
- játra účinky léků enzymologie MeSH
- katalasa metabolismus MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- maláty farmakologie MeSH
- membránové transportní proteiny účinky léků genetika metabolismus MeSH
- messenger RNA metabolismus MeSH
- polymerázová řetězová reakce s reverzní transkripcí MeSH
- potkani Sprague-Dawley MeSH
- regulace genové exprese enzymů MeSH
- stárnutí genetika metabolismus MeSH
- superoxiddismutasa metabolismus MeSH
- transportní proteiny účinky léků metabolismus MeSH
- transportní systém pro kyselé aminokyseliny účinky léků metabolismus MeSH
- upregulace MeSH
- věkové faktory MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Glioblastoma-initiating cells (GICs) are self-renewing tumorigenic sub-populations, contributing to therapeutic resistance via decreased sensitivity to ionizing radiation (IR). GIC survival following IR is attributed to an augmented response to genotoxic stress. We now report that GICs are primed to handle additional stress due to basal activation of single-strand break repair (SSBR), the main DNA damage response pathway activated by reactive oxygen species (ROS), compared with non-GICs. ROS levels were higher in GICs and likely contributed to the oxidative base damage and single-strand DNA breaks found elevated in GICs. To tolerate constitutive DNA damage, GICs exhibited a reliance on the key SSBR mediator, poly-ADP-ribose polymerase (PARP), with decreased viability seen upon small molecule inhibition to PARP. PARP inhibition (PARPi) sensitized GICs to radiation and inhibited growth, self-renewal, and DNA damage repair. In vivo treatment with PARPi and radiotherapy attenuated radiation-induced enrichment of GICs and inhibited the central cancer stem cell phenotype of tumor initiation. These results indicate that elevated PARP activation within GICs permits exploitation of this dependence, potently augmenting therapeutic efficacy of IR against GICs. In addition, our results support further development of clinical trials with PARPi and radiation in glioblastoma.
- MeSH
- apoptóza účinky léků MeSH
- fenotyp MeSH
- ftalaziny farmakologie MeSH
- glioblastom metabolismus patologie terapie MeSH
- lidé MeSH
- myši nahé MeSH
- myši MeSH
- nádorové kmenové buňky účinky léků metabolismus patologie MeSH
- oprava DNA MeSH
- PARP inhibitory MeSH
- piperaziny farmakologie MeSH
- poly(ADP-ribosa)-polymerasy metabolismus MeSH
- poškození DNA MeSH
- proliferace buněk účinky léků MeSH
- reaktivní formy kyslíku metabolismus MeSH
- viabilita buněk účinky léků MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
Although vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) is traditionally regarded as an endothelial cell protein, evidence suggests that VEGFRs may be expressed by cancer cells. Glioblastoma multiforme (GBM) is a lethal cancer characterized by florid vascularization and aberrantly elevated VEGF. Antiangiogenic therapy with the humanized VEGF antibody bevacizumab reduces GBM tumor growth; however, the clinical benefits are transient and invariably followed by tumor recurrence. In this study, we show that VEGFR2 is preferentially expressed on the cell surface of the CD133(+) human glioma stem-like cells (GSCs), whose viability, self-renewal, and tumorigenicity rely, at least in part, on signaling through the VEGF-VEGFR2-Neuropilin-1 (NRP1) axis. We find that the limited impact of bevacizumab-mediated VEGF blockage may reflect ongoing autocrine signaling through VEGF-VEGFR2-NRP1, which is associated with VEGFR2-NRP1 recycling and a pool of active VEGFR2 within a cytosolic compartment of a subset of human GBM cells. Whereas bevacizumab failed to inhibit prosurvival effects of VEGFR2-mediated signaling, GSC viability under unperturbed or radiation-evoked stress conditions was attenuated by direct inhibition of VEGFR2 tyrosine kinase activity and/or shRNA-mediated knockdown of VEGFR2 or NRP1. We propose that direct inhibition of VEGFR2 kinase may block the highly dynamic VEGF-VEGFR2-NRP1 pathway and inspire a GBM treatment strategy to complement the currently prevalent ligand neutralization approach.
- MeSH
- autokrinní signalizace MeSH
- endozomy fyziologie MeSH
- glioblastom * krevní zásobení patologie patofyziologie terapie MeSH
- humanizované monoklonální protilátky farmakologie MeSH
- lidé MeSH
- malá interferující RNA genetika MeSH
- nádorové kmenové buňky * patologie fyziologie MeSH
- neuropilin-1 * antagonisté a inhibitory genetika fyziologie MeSH
- patologická angiogeneze MeSH
- proliferace buněk MeSH
- vaskulární endoteliální růstový faktor A * antagonisté a inhibitory fyziologie MeSH
- viabilita buněk MeSH
- Check Tag
- lidé MeSH
Using the protein-protein docking program, this study investigates the relationship between TRAF2 and its related proteins and the diversity within the 3D structures of TRAF2s. TRAF2 exists in monomer, trimer, and hexamer forms and it can combine with a number of proteins. Through comparative analysis we found that TRAF2(122), TRAF2(22), TRAF2(21740), TRAF2(2), TRAF2( 22ABC), and TRAF2(Phyre) perform very close homoousia in docking with the same group of ligands, though these TRAF2s come from different sources. The TRAF2-related proteins of cluster 1 change docking values strongly from top to bottom. The TRAF2- related proteins of clusters 2 and 3 have acceptable variation of the docking values. In consideration of the amino acid percentage, TRAF2-related proteins of cluster 2 represent appropriate docking values.
