| 1. |
- Lee, Chunsik, et al.
(författare)
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VEGF-B prevents excessive angiogenesis by inhibiting FGF2/FGFR1 pathway
- 2023
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Ingår i: SIGNAL TRANSDUCTION AND TARGETED THERAPY. - : SPRINGERNATURE. - 2095-9907 .- 2059-3635. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Although VEGF-B was discovered as a VEGF-A homolog a long time ago, the angiogenic effect of VEGF-B remains poorly understood with limited and diverse findings from different groups. Notwithstanding, drugs that inhibit VEGF-B together with other VEGF family members are being used to treat patients with various neovascular diseases. It is therefore critical to have a better understanding of the angiogenic effect of VEGF-B and the underlying mechanisms. Using comprehensive in vitro and in vivo methods and models, we reveal here for the first time an unexpected and surprising function of VEGF-B as an endogenous inhibitor of angiogenesis by inhibiting the FGF2/FGFR1 pathway when the latter is abundantly expressed. Mechanistically, we unveil that VEGF-B binds to FGFR1, induces FGFR1/VEGFR1 complex formation, and suppresses FGF2-induced Erk activation, and inhibits FGF2-driven angiogenesis and tumor growth. Our work uncovers a previously unrecognized novel function of VEGF-B in tethering the FGF2/FGFR1 pathway. Given the anti-angiogenic nature of VEGF-B under conditions of high FGF2/FGFR1 levels, caution is warranted when modulating VEGF-B activity to treat neovascular diseases.
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| 2. |
- Li, Shasha, et al.
(författare)
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A systems genetics approach to revealing the Pdgfb molecular network of the retina
- 2020
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Ingår i: Molecular Vision. - : MOLECULAR VISION. - 1090-0535. ; 26, s. 459-471
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Platelet-derived growth factor (PDGF) signaling is well known to be involved in vascular retinopathies. Among the PDGF family, the subunit B (PDGFB) protein is considered a promising therapeutic target. This study aimed to identify the genes and potential pathways through which PDGFB affects retinal phenotypes by using a systems genetics approach. Methods: Gene expression data had been previously generated in a laboratory for the retinas of 75 C57BL/6J(B6) X DBA/2J (BXD) recombinant inbred (RI) strains. Using this data, the genetic correlation method was used to identify genes correlated to Pdgfb. A correlation between intraocular pressure (TOP) and Pdgfb was calculated based on the Pearson correlation coefficient. A gene set enrichment analysis and the STRING database were used to evaluate gene function and to construct protein-protein interaction (PPI) networks. Results: Pdgfb was a cis-regulated gene in the retina; its expression had a significant correlation with IOP (r = 0.305; p value = 0.012). The expression levels of 2,477 genes also had significant correlations with Pdgfb expressions (p<0.05), among which Atf4 was the most positively correlated (r = 0.628; p value = 1.29e-10). Thus, Atf4 was highly expressed in the retina and shared the transcription factor (TF)Hnf4a binding site with Pdgfb. Gene Ontology and a pathway analysis revealed that Pdgfb and its covariates were highly involved in mitogen-activated protein kinase (MAPK) and vascular endothelial growth factor (VEGF) pathways. A generated gene network indicated that Pdgfb was directly connected to and interacted with other genes with similar biologic functions. Conclusions: A systems genetics analysis revealed that Pdgfb had significant interactions with Atf4 and other genes in MAPK and VEGF pathways, through which Pdgfb was important in maintaining retina function. These findings provided basic information regarding the Pdgfb regulation mechanism and potential therapy for vascular retinopathies.
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| 3. |
- Sun, Mengtao, et al.
(författare)
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Direct visual evidence for the chemical mechanism of surface-enhanced resonance Raman scattering via charge transfer: (II) Binding-site and quantum-size effects
- 2009
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Ingår i: Journal of Raman Spectroscopy. - : Wiley. - 1097-4555 .- 0377-0486. ; 40:9, s. 1172-1177
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Tidskriftsartikel (refereegranskat)abstract
- We describe quantum-size and binding-site effects on the chemical and local field enhancement mechanisms of surface-enhanced resonance Raman scattering (SERRS), in which the pyridine molecule is adsorbed on one of the vertices of the Ag-20 tetrahedron. We first investigated the influence of the binding site on normal Raman scattering (NRS) and excited state properties of optical absorption spectroscopy. Second, we investigated the quantum-size effect on the electromagnetic (EM) and chemical mechanism from 300 to 1000 nm with charge difference density. It is found that the strong absorption at around 350 nm is mainly the charge transfer (CT) excitation (CT between the molecule and the silver cluster) for large clusters, which is the direct evidence for the chemical enhancement mechanism for SERRS; for a small cluster the strong absorption around 350 nm is mainly intracluster excitation, which is the direct evidence for the EM enhancement mechanism. This conclusion is further confirmed with the general Mie theory. The plasmon peak in EM enhancement will be red-shifted with the increase of cluster size. The influence of the binding site and quantum-size effects on NRS, as well as chemical and EM enhancement mechanisms on SERRS, is significant. Copyright (C) 2009 John Wiley & Sons, Ltd.
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| 4. |
- Wei, Xiaodan, et al.
(författare)
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PDLIM5 identified by label-free quantitative proteomics as a potential novel biomarker of papillary thyroid carcinoma
- 2018
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 499:2, s. 338-344
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Tidskriftsartikel (refereegranskat)abstract
- In order to better understand the mechanisms underlying the development of papillary thyroid carcinoma (PTC), and to identify new potential biomarkers, high-resolution label-free mass spectrometry was performed on PTC tissues and adjacent normal thyroid tissues from six patients. In this process, 2788 proteins were identified, out of which 49 proteins presented significant differences between PTC tissues and adjacent normal thyroid tissues. Gene ontology revealed that the majority of these proteins are involved in the catalytic activity and binding. We selected three proteins with differential expressions: PDZ and LIM domain 5 (PDLIM5), PDLIM1 and ALDH1A1; Protein expressions were further verified by RT-PCR and western blot. Among these, expression of PDLIM5 and PDLIM1 was up-regulated, while that of ALDH1A1 was down-regulated in PTC tissues. Next, we confirmed their expression through quantitative dot blot (QDB) technique. We found that knockdown of PDLIM5 expression in the B-CPAP cell line could inhibit the migration, invasion and proliferation of PTC cells. In addition, PDLIM5 knockdown reduced Ras and Phospho-ERK1/2 expression. Thus, we suggested that PDLIM5 promotes PTC via activation of the Ras-ERK pathway. Our research provides new molecular insight into the function of PDLIM5, which may assist in studying the mechanism of PTC. In addition, PDLIM5 could be further explored as a potential candidate for PTC treatment.
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| 5. |
- Xu, Bohan, et al.
(författare)
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Role of VEGFR2 in Mediating Endoplasmic Reticulum Stress Under Glucose Deprivation and Determining Cell Death, Oxidative Stress, and Inflammatory Factor Expression
- 2021
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Ingår i: Frontiers in Cell and Developmental Biology. - : Frontiers Media SA. - 2296-634X. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Retinal pigment epithelium (RPE), a postmitotic monolayer located between the neuroretina and choroid, supports the retina and is closely associated with vision loss diseases such as age-related macular degeneration (AMD) upon dysfunction. Although environmental stresses are known to play critical roles in AMD pathogenesis and the roles of other stresses have been well investigated, glucose deprivation, which can arise from choriocapillary flow voids, has yet to be fully explored. In this study, we examined the involvement of VEGFR2 in glucose deprivation-mediated cell death and the underlying mechanisms. We found that VEGFR2 levels are a determinant for RPE cell death, a critical factor for dry AMD, under glucose deprivation. RNA sequencing analysis showed that upon VEGFR2 knockdown under glucose starvation, endoplasmic reticulum (ER) stress and unfolded protein response (UPR) are reduced. Consistently, VEGFR2 overexpression increased ER stress under the same condition. Although VEGFR2 was less expressed compared to EGFR1 and c-Met in RPE cells, it could elicit a higher level of ER stress induced by glucose starvation. Finally, downregulated VEGFR2 attenuated the oxidative stress and inflammatory factor expression, two downstream targets of ER stress. Our study, for the first time, has demonstrated a novel role of VEGFR2 in RPE cells under glucose deprivation, thus providing valuable insights into the mechanisms of AMD pathogenesis and suggesting that VEGFR2 might be a potential therapeutic target for AMD prevention, which may impede its progression.
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| 6. |
- Zheng, Fengshan, et al.
(författare)
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Experimental observation of chiral magnetic bobbers in B20-type FeGe
- 2018
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Ingår i: Nature Nanotechnology. - : NATURE PUBLISHING GROUP. - 1748-3387 .- 1748-3395. ; 13:6, s. 451-
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Tidskriftsartikel (refereegranskat)abstract
- Chiral magnetic skyrmions(1,2) are nanoscale vortex-like spin textures that form in the presence of an applied magnetic field in ferromagnets that support the Dzyaloshinskii-Moriya interaction (DMI) because of strong spin-orbit coupling and broken inversion symmetry of the crystal(3,4). In sharp contrast to other systems(5,6) that allow for the formation of a variety of two-dimensional (2D) skyrmions, in chiral magnets the presence of the DMI commonly prevents the stability and coexistence of topological excitations of different types(7). Recently, a new type of localized particle-like object-the chiral bobber (ChB)-was predicted theoretically in such materials(8). However, its existence has not yet been verified experimentally. Here, we report the direct observation of ChBs in thin films of B20-type FeGe by means of quantitative off-axis electron holography (EH). We identify the part of the temperature-magnetic field phase diagram in which ChBs exist and distinguish two mechanisms for their nucleation. Furthermore, we show that ChBs are able to coexist with skyrmions over a wide range of parameters, which suggests their possible practical applications in novel magnetic solid-state memory devices, in which a stream of binary data bits can be encoded by a sequence of skyrmions and bobbers.
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| 7. |
- Zhu, Yanping, et al.
(författare)
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System biology analysis reveals the role of voltage-dependent anion channel in mitochondrial dysfunction during non-alcoholic fatty liver disease progression into hepatocellular carcinoma
- 2020
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Ingår i: Cancer Science. - : WILEY. - 1347-9032 .- 1349-7006. ; 111:11, s. 4288-4302
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Tidskriftsartikel (refereegranskat)abstract
- Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of hepatocellular carcinoma (HCC), but the underlying mechanisms behind the correlation of NAFLD with HCC are unclear. We aimed to uncover the genes and potential mechanisms that drive this progression. This study uncovered the genes and potential mechanisms through a multiple 'omics integration approach. Quantitative proteomics combined with phenotype-association analysis was performed. To investigate the potential mechanisms, a comprehensive transcriptome/lipidome/phenome-wide association analysis was performed in genetic reference panel BXD mice strains. The quantitative proteomics combined with phenotype-association results showed that VDAC1 was significantly increased in tumor tissues and correlated with NAFLD-related traits. Gene co-expression network analysis indicated that VDAC1 is involved in mitochondria dysfunction in the tumorigenic/tumor progression. The association between VDAC1 and mitochondria dysfunction can be explained by the fact that VDAC1 was associated with mitochondria membrane lipids cardiolipin (CL) composition shift. VDAC1 was correlated with the suppression of mature specie CL(LLLL) and elevation level of nascent CL species. Such profiling shift was supported by the significant positive correlation between VDAC1 and PTPMT1, as well as negative correlation with CL remodeling enzyme Tafazzin (TAZ). This study confirmed that the expression of VADC1 was dysregulated in NAFLD-driven HCC and associated with NAFLD progression. The VDAC1-driven mitochondria dysfunction is associated with cardiolipin composition shift, which causes alteration of mitochondria membrane properties.
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