| 1. |
- Dang, Thanh Chung, et al.
(författare)
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Powerful Homeostatic Control of Oligodendroglial Lineage by PDGFR alpha in Adult Brain
- 2019
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Ingår i: Cell Reports. - : CELL PRESS. - 2211-1247. ; 27:4, s. 1073-1089
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Tidskriftsartikel (refereegranskat)abstract
- Oligodendrocyte progenitor cells (OPCs) are widely distributed cells of ramified morphology in adult brain that express PDGFR alpha and NG2. They retain mitotic activities in adulthood and contribute to oligodendrogenesis and myelin turnover; however, the regulatory mechanisms of their cell dynamics in adult brain largely remain unknown. Here, we found that global Pdgfra inactivation in adult mice rapidly led to elimination of OPCs due to synchronous maturation toward oligodendrocytes. Surprisingly, OPC densities were robustly reconstituted by the active expansion of Nestin(+) immature cells activated in meninges and brain parenchyma, as well as a few OPCs that escaped from Pdgfra inactivation. The multipotent immature cells were induced in the meninges of Pdgfra-inactivated mice, but not of control mice. Our findings revealed powerful homeostatic control of adult OPCs, engaging dual cellular sources of adult OPC formation. These properties of the adult oligodendrocyte lineage and the alternative OPC source may be exploited in regenerative medicine.
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| 2. |
- Egawa-Tsuzuki, Tomoko, et al.
(författare)
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The PDGF B-chain is involved in the ontogenic susceptibility of the developing rat brain to NMDA toxicity.
- 2004
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Ingår i: Experimental neurology. - : Elsevier BV. - 0014-4886. ; 186:1, s. 89-98
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Tidskriftsartikel (refereegranskat)abstract
- Hypoxic-ischemic (H-I) injury to neonatal brains can cause a life-long neuronal deficit because of increased susceptibility in the neonatal period. Excitotoxicity due to overstimulation of the N-methyl-d-aspartate receptor (NMDAR) is assumed to be the basis of the injury. However, the ontogenic profile of the susceptibility does not directly correlate with the levels of NMDAR expression. Platelet-derived growth factor B-chain (PDGF-B) has been reported to protect neurons by suppressing the NMDA-evoked current and translocating the glutamate transporter to the cell membrane. Thus, we assessed the relationship between the susceptibility to H-I injury and the expression of PDGF-B in neonatal rat brain. PDGF-B infusion before and after an intrastriatal NMDA injection significantly reduced the size of the lesions in 7-day-old rats, when they are most susceptible and the neuronal expression of PDGF-B is low. Fourteen-day-old neonatal rats were found to be resistant to NMDA injury, even though NMDARs are expressed at high levels in the brain at this age. Inhibition of PDGF-B protein synthesis by antisense oligodeoxynucleotides increased the size of the NMDA-induced lesions up to 6-fold at postnatal day 14, when PDGF-B is expressed at high levels in neurons. These data suggest that PDGF-B is an important physiological modulator of NMDAR excitability in the developing brain, and that the balance between the expression of NMDAR and PDGF-B partly determines the ontogenic susceptibility to brain injury. Enhancement of the PDGF-B/receptor signal pathway might rescue neonatal brains at risk of H-I injury.
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| 3. |
- Ishii, Yoko, et al.
(författare)
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Characterization of neuroprogenitor cells expressing the PDGF beta-receptor within the subventricular zone of postnatal mice.
- 2008
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Ingår i: Molecular and cellular neurosciences. - : Elsevier BV. - 1095-9327 .- 1044-7431. ; 37:3, s. 507-18
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Tidskriftsartikel (refereegranskat)abstract
- We report a considerable number of cells in the ventricular and the subventricular zones (SVZ) of newborn mice to stain positive for the PDGF beta-receptor (PDGFRB). Many of them also stained for nestin and/or GFAP but less frequently for the neuroblast marker doublecortin and for the mitotic marker Ki-67. The SVZ of mice with nestin-Cre conditional deletion of PDGFRB expressed the receptor only on blood vessels and was devoid of any morphological abnormality. PDGFRB(-/-) neurospheres showed a higher rate of apoptosis without any significant decrease in proliferation. They demonstrated reduced capacities of migration and neuronal differentiation in response to not only PDGF-BB but also bFGF. Furthermore, the PDGFR kinase inhibitor STI571 blocked the effects of bFGF in control neurosphere cultures. bFGF increased the activity of the PDGFRB promoter as well as the expression and phosphorylation of PDGFRB. These results suggest the presence of the signaling convergence between PDGF and FGF. PDGFRB is needed for survival, and the effects of bFGF in migration and neural differentiation of the cells may be potentiated by induction of PDGFRB.
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| 4. |
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| 5. |
- Nguyen, Quang Linh, et al.
(författare)
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Vascular PDGFR-alpha protects against BBB dysfunction after stroke in mice
- 2021
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Ingår i: Angiogenesis. - : Springer. - 0969-6970 .- 1573-7209. ; 24, s. 35-46
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Tidskriftsartikel (refereegranskat)abstract
- Blood-brain barrier (BBB) dysfunction underlies the pathogenesis of many neurological diseases. Platelet-derived growth factor receptor-alpha (PDGFR alpha) induces hemorrhagic transformation (HT) downstream of tissue plasminogen activator in thrombolytic therapy of acute stroke. Thus, PDGFs are attractive therapeutic targets for BBB dysfunction. In the present study, we examined the role of PDGF signaling in the process of tissue remodeling after middle cerebral arterial occlusion (MCAO) in mice. Firstly, we found that imatinib increased lesion size after permanent MCAO in wild-type mice. Moreover, imatinib-induced HT only when administrated in the subacute phase of MCAO, but not in the acute phase. Secondly, we generated genetically mutated mice (C-KO mice) that showed decreased expression of perivascular PDGFR alpha. Additionally, transient MCAO experiments were performed in these mice. We found that the ischemic lesion size was not affected; however, the recruitment of PDGFR alpha/type I collagen-expressing perivascular cells was significantly downregulated, and HT and IgG leakage was augmented only in the subacute phase of stroke in C-KO mice. In both experiments, we found that the expression of tight junction proteins and PDGFR beta-expressing pericyte coverage was not significantly affected in imatinib-treated mice and in C-KO mice. The specific implication of PDGFR alpha signaling was suggestive of protective effects against BBB dysfunction during the subacute phase of stroke. Vascular TGF-beta 1 expression was downregulated in both imatinib-treated and C-KO mice, along with sustained levels of MMP9. Therefore, PDGFR alpha effects may be mediated by TGF-beta 1 which exerts potent protective effects in the BBB.
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| 6. |
- Xue, Yuan, et al.
(författare)
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PDGF-BB modulates hematopoiesis and tumor angiogenesis by inducing erythropoietin production in stromal cells
- 2012
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Ingår i: Nature Medicine. - : Nature Publishing Group. - 1078-8956 .- 1546-170X. ; 18:1, s. 100-110
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Tidskriftsartikel (refereegranskat)abstract
- The platelet-derived growth factor (PDGF) signaling system contributes to tumor angiogenesis and vascular remodeling. Here we show in mouse tumor models that PDGF-BB induces erythropoietin (EPO) mRNA and protein expression by targeting stromal and perivascular cells that express PDGF receptor-beta (PDGFR-beta). Tumor-derived PDGF-BB promoted tumor growth, angiogenesis and extramedullary hematopoiesis at least in part through modulation of EPO expression. Moreover, adenoviral delivery of PDGF-BB to tumor-free mice increased both EPO production and erythropoiesis, as well as protecting from irradiation-induced anemia. At the molecular level, we show that the PDGF-BB PDGFR-beta signaling system activates the EPO promoter, acting in part through transcriptional regulation by the transcription factor Atf3, possibly through its association with two additional transcription factors, c-Jun and Sp1. Our findings suggest that PDGF-BB-induced EPO promotes tumor growth through two mechanisms: first, paracrine stimulation of tumor angiogenesis by direct induction of endothelial cell proliferation, migration, sprouting and tube formation, and second, endocrine stimulation of extramedullary hematopoiesis leading to increased oxygen perfusion and protection against tumor-associated anemia.
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