| 1. |
- Wallmann, Tatjana, et al.
(författare)
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Microglia Induce PDGFRB Expression in Glioma Cells to Enhance Their Migratory Capacity
- 2018
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Ingår i: iScience. - : Elsevier BV. - 2589-0042. ; 9, s. 71-83
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Tidskriftsartikel (refereegranskat)abstract
- High-grade gliomas (HGGs) are the most aggressive and invasive primary brain tumors. The platelet-derived growth factor (PDGF) signaling pathway drives HGG progression, and enhanced expression of PDGF receptors (PDGFRs) is a well-established aberration in a subset of glioblastomas (GBMs). PDGFRA is expressed in glioma cells, whereas PDGFRB is mostly restricted to the glioma-associated stroma. Here we show that the spatial location of TAMMs correlates with the expansion of a subset of tumor cells that have acquired expression of PDGFRB in both mouse and human low-grade glioma and HCGs. Furthermore, M2-polarized microglia but not bone marrow (BM)-derived macrophages (BMDMs) induced PDGFRB expression in glioma cells and stimulated their migratory capacity. These findings illustrate a heterotypic cross-talk between microglia and glioma cells that may enhance the migratory and invasive capacity of the latter by inducing PDGFRB.
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| 2. |
- Xie, Xin, et al.
(författare)
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In Mitochondria beta-Actin Regulates mtDNA Transcription and Is Required for Mitochondrial Quality Control
- 2018
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Ingår i: iScience. - : Elsevier BV. - 2589-0042. ; 3, s. 226-237
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Tidskriftsartikel (refereegranskat)abstract
- In eukaryotic cells, actin regulates both cytoplasmic and nuclear functions. However, whether actin-based structures are present in the mitochondria and are involved in mitochondrial functions has not been investigated. Here, using wild-type beta-actin +/+ and knockout (KO) b-actin -/- mouse embryonic fibroblasts we show evidence for the defect in maintaining mitochondrial membrane potential (MMP) in beta-actin-null cells. MMP defects were associated with impaired mitochondrial DNA (mtDNA) transcription and nuclear oxidative phosphorylation (OXPHOS) gene expression. Using super-resolution microscopy we provided direct evidence on the presence of beta-actin-containing structures inside mitochondria. Large aggregates of TFAM-stained nucleoids were observed in bulb-shaped mitochondria in KO cells, suggesting defects in mitochondrial nucleoid segregation without beta-actin. The observation that mitochondria-targeted beta-actin rescued mtDNA transcription and MMP suggests an indispensable functional role of a mitochondrial beta-actin pool necessary for mitochondrial quality control.
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| 3. |
- Zhang, Biaobiao, et al.
(författare)
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Identifying MnVII-oxo Species during Electrochemical Water Oxidation by Manganese Oxide
- 2018
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Ingår i: iScience. - : Elsevier BV. - 2589-0042. ; 4, s. 144-152
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Tidskriftsartikel (refereegranskat)abstract
- Identifying surface active intermediate species is essential to reveal the catalytic mechanism of water oxidation by metal-oxides-based catalysts and to develop more efficient catalysts for oxygen-oxygen bond formation. Here we report, through electrochemical methods and ex situ infrared spectroscopy, the identification of a MnVII = O intermediate during catalytic water oxidation by a c-disordered δ-MnOx with an onset-potential-dependent reduction peak at 0.93 V and an infrared peak at 912 cm−1. This intermediate is proved to be highly reactive and much more oxidative than permanganate ion. Therefore, we propose a new catalytic mechanism for water oxidation catalyzed by Mn oxides, with involvement of the MnVII = O intermediate in a resting state and the MnIV−O−MnVII = O as a real active species for oxygen-oxygen bond formation. Inorganic Chemistry; Surface Science; Energy Materials; Electrocatalysis.
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