| 1. |
- He, Qi, et al.
(författare)
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Pericyte dysfunction due to Shb gene deficiency increases B16F10 melanoma lung metastasis
- 2020
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 147:9, s. 2634-2644
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Tidskriftsartikel (refereegranskat)abstract
- Intravasation, vascular dissemination and metastasis of malignant tumor cells require their passage through the vascular wall which is commonly composed of pericytes and endothelial cells. We currently decided to investigate the relative contribution of these cell types to B16F10 melanoma metastasis in mice using an experimental model of host Shb gene (Src homology 2 domain containing protein B) inactivation. Conditional inactivation of Shb in endothelial cells using Cdh5-CreERt2 resulted in decreased tumor growth, reduced vascular leakage, increased hypoxia and no effect on pericyte coverage and lung metastasis. RNAseq of tumor endothelial cells from these mice revealed changes in cellular components such as adherens junctions and focal adhesions by gene ontology analysis that were in line with the observed effects on leakage and junction morphology. Conditional inactivation of Shb in pericytes using Pdgfrb-CreERt2 resulted in decreased pericyte coverage of small tumor vessels with lumen, increased leakage, aberrant platelet-derived growth factor receptor B (PDGFRB) signaling and a higher frequency of lung metastasis without concomitant effects on tumor growth or oxygenation. Flow cytometry failed to reveal immune cell alterations that could explain the metastatic phenotype in this genetic model of Shb deficiency. It is concluded that proper pericyte function plays a significant role in suppressing B16F10 lung metastasis.
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| 2. |
- Hu, Xuchen, et al.
(författare)
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GPIHBP1 expression in gliomas promotes utilization of lipoprotein-derived nutrients
- 2019
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Ingår i: eLIFE. - : ELIFE SCIENCES PUBLICATIONS LTD. - 2050-084X. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- GPIHBP1, a GPI-anchored protein of capillary endothelial cells, binds lipoprotein lipase (LPL) within the subendothelial spaces and shuttles it to the capillary lumen. GPIHBP1-bound LPL is essential for the margination of triglyceride-rich lipoproteins (TRLs) along capillaries, allowing the lipolytic processing of TRLs to proceed. In peripheral tissues, the intravascular processing of TRLs by the GPIHBP1-LPL complex is crucial for the generation of lipid nutrients for adjacent parenchymal cells. GPIHBP1 is absent from the capillaries of the brain, which uses glucose for fuel; however, GPIHBP1 is expressed in the capillaries of mouse and human gliomas. Importantly, the GPIHBP1 in glioma capillaries captures locally produced LPL. We use NanoSIMS imaging to show that TRLs marginate along glioma capillaries and that there is uptake of TRL-derived lipid nutrients by surrounding glioma cells. Thus, GPIHBP1 expression in gliomas facilitates TRL processing and provides a source of lipid nutrients for glioma cells.
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| 3. |
- Wang, Jianhao, et al.
(författare)
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An Integrated Transcriptome Analysis Reveals IGFBP7 Upregulation in Vasculature in Traumatic Brain Injury
- 2021
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Ingår i: Frontiers in Genetics. - : Frontiers Media S.A.. - 1664-8021. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Vasculature plays critical roles in the pathogenesis and neurological repair of traumatic brain injury (TBI). However, how vascular endothelial cells respond to TBI at the molecular level has not been systematically reviewed. Here, by integrating three transcriptome datasets including whole cortex of mouse brain, FACS-sorted mouse brain endothelial cells, and single cell sequencing of mouse brain hippocampus, we revealed the key molecular alteration of endothelial cells characterized by increased Myc targets and Epithelial-Mesenchymal Transition signatures. In addition, immunofluorescence staining of patients' samples confirmed that IGFBP7 was up-regulated in vasculature in response to TBI. TGF beta 1, mainly derived from microglia and endothelial cells, sufficiently induces IGFBP7 expression in cultured endothelial cells, and is significantly upregulated in response to TBI. Our results identified IGFBP7 as a potential biomarker of vasculature in response to TBI, and indicate that TGF beta signaling may contribute to the upregulation of IGFBP7 in the vasculature.
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| 4. |
- Xie, Yuan, et al.
(författare)
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Key molecular alterations in endothelial cells in human glioblastoma uncovered through single-cell RNA sequencing
- 2021
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Ingår i: JCI Insight. - : American Society For Clinical Investigation. - 2379-3708. ; 6:15
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Tidskriftsartikel (refereegranskat)abstract
- Passage of systemically delivered pharmacological agents into the brain is largely blocked by the blood-brain-barrier (BBB), an organotypic specialization of brain endothelial cells (ECs). Tumor vessels in glioblastoma (GBM), the most common malignant brain tumor in humans, are abnormally permeable, but this phenotype is heterogeneous and may differ between the tumor's center and invasive front. Here, through single-cell RNA sequencing (scRNA-seq) of freshly isolated ECs from human glioblastoma and paired tumor peripheral tissues, we have constructed a molecular atlas of human brain ECs providing unprecedented molecular insight into the heterogeneity of the human BBB and its molecular alteration in glioblastoma. We identified 5 distinct EC phenotypes representing different states of EC activation and BBB impairment, and associated with different anatomical locations within and around the tumor. This unique data resource provides key information for designing rational therapeutic regimens and optimizing drug delivery.
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| 5. |
- Yang, Fan, et al.
(författare)
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Uncovering a Distinct Gene Signature in Endothelial Cells Associated With Contrast Enhancement in Glioblastoma
- 2021
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Ingår i: Frontiers in Oncology. - : Frontiers Media S.A.. - 2234-943X. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Glioblastoma (GBM) is the most aggressive and lethal type of brain tumors. Magnetic resonance imaging (MRI) has been commonly used for GBM diagnosis. Contrast enhancement (CE) on T1-weighted sequences are presented in nearly all GBM as a result of high vascular permeability in glioblastomas. Although several radiomics studies indicated that CE is associated with distinct molecular signatures in tumors, the effects of vascular endothelial cells, the key component of blood brain barrier (BBB) controlling vascular permeability, on CE have not been thoroughly analyzed. Methods Endothelial cell enriched genes have been identified using transcriptome data from 128 patients by a systematic method based on correlation analysis. Distinct endothelial cell enriched genes associated with CE were identified by analyzing difference of correlation score between CE-high and CE-low GBM cases. Immunohistochemical staining was performed on in-house patient cohort to validate the selected genes associated with CE. Moreover, a survival analysis was conducted to uncover the relation between CE and patient survival. Results We illustrated that CE is associated with distinct vascular molecular imprints characterized by up-regulation of pro-inflammatory genes and deregulation of BBB related genes. Among them, PLVAP is up-regulated, whereas TJP1 and ABCG2 are down-regulated in the vasculature of GBM with high CE. In addition, we found that the high CE is associated with poor prognosis and GBM mesenchymal subtype. Conclusion We provide an additional insight to reveal the molecular trait for CE in MRI images with special focus on vascular endothelial cells, linking CE with BBB disruption in the molecular level. This study provides a potential new direction that may be applied for the treatment optimization based on MRI features.
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| 6. |
- Zhang, Yanyu, et al.
(författare)
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1p/19q co-deletion status is associated with distinct tumor-associated macrophage infiltration in IDH mutated lower-grade gliomas
- 2021
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Ingår i: Cellular Oncology. - : Springer. - 2211-3428 .- 2211-3436. ; 44:1, s. 193-204
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Tidskriftsartikel (refereegranskat)abstract
- Background Tumor-associated macrophages (TAM)s are critical regulators of glioma progression. As yet, however, TAMs in isocitrate dehydrogenase (IDH) mutated lower-grade gliomas (LGGs) have not been thoroughly investigated. The aim of this study was to determine whether 1p/19q co-deletion status affects the TAM phenotype or its prevalence in IDH mutated LGGs. Methods TAMs in IDH mutated LGGs were analyzed using transcriptome data from 230 samples in the TCGA database in combination with transcriptome data from single-cell RNA sequencing of IDH-mutated LGGs. Proteins potentially involved in TAM regulation were examined by immuno-staining in primary LGG samples harboring IDH mutations. Essential signaling pathways regulating TAM phenotypes were investigated in a glioma mouse model using small molecule inhibitors. Results Most of the TAMs in IDH-mutated LGGs expressed the M1 activation markers CD86 and TNF, whereas a subset of individual TAMs co-expressed both M1 and M2-related markers. Bioinformatics analysis in combination with immuno-staining of IDH-mutated patient samples revealed higher amounts of TAMs expressing M2-related markers in 1p/19q non-codeletion IDH-mutated LGGs compared to 1p/19q codeletion LGGs. The levels of transforming growth factor beta 1 (TGF beta 1) and macrophage colony-stimulating factor (M-CSF) were significantly higher in 1p/19q non-codeletion LGGs than in 1p/19q codeletion LGGs. M-CSF and TGF beta 1 signal inhibition decreased tumor growth and modulated the TAM phenotype in a glioma mouse model. Conclusions Our data indicate that 1p/19q co-deletion status relates to distinct TAM infiltration in gliomas, which is likely mediated by M-CSF and TGF beta 1 signaling. M-CSF and TGF beta 1 signaling may play a pivotal role in regulating the TAM phenotype in glioma.
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| 7. |
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| 8. |
- Ando, Koji, et al.
(författare)
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KCNJ8/ABCC9-containing K-ATP channel modulates brain vascular smooth muscle development and neurovascular coupling
- 2022
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Ingår i: Developmental Cell. - : Elsevier. - 1534-5807 .- 1878-1551. ; 57:11, s. 1383-1399.e7
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Tidskriftsartikel (refereegranskat)abstract
- Loss- or gain-of-function mutations in ATP-sensitive potassium channel (K-ATP)-encoding genes, KCNJ8 and ABCC9, cause human central nervous system disorders with unknown pathogenesis. Here, using mice, zebrafish, and cell culture models, we investigated cellular and molecular causes of brain dysfunctions derived from altered K-ATP channel function. We show that genetic/chemical inhibition or activation of KCNJ8/ABCC9-containing K-ATP channel function leads to brain-selective suppression or promotion of arterial/arteriolar vascular smooth muscle cell (VSMC) differentiation, respectively. We further show that brain VSMCs develop from KCNJ8/ABCC9-containing K-ATP channel-expressing mural cell progenitor and that K-ATP channel cell autonomously regulates VSMC differentiation through modulation of intracellular Ca2+ oscillation via voltage-dependent calcium channels. Consistent with defective VSMC development, Kcnj8 knockout mice showed deficiency in vasoconstrictive capacity and neuronal-evoked vasodilation leading to local hyperemia. Our results demonstrate a role for KCNJ8/ABCC9-containing K-ATP channels in the differentiation of brain VSMC, which in turn is necessary for fine-tuning of cerebral blood flow.
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| 9. |
- Andrae, Johanna, et al.
(författare)
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A role for PDGF-C/PDGFR alpha signaling in the formation of the meningeal basement membranes surrounding the cerebral cortex
- 2016
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Ingår i: Biology Open. - : The Company of Biologists. - 2046-6390. ; 5:4, s. 461-474
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Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor-C (PDGF-C) is one of three known ligands for the tyrosine kinase receptor PDGFR alpha. Analysis of Pdgfc null mice has demonstrated roles for PDGF-C in palate closure and the formation of cerebral ventricles, but redundancy with other PDGFR alpha ligands might obscure additional functions. In search of further developmental roles for PDGF-C, we generated mice that were double mutants for Pdgfc(-/-) and Pdgfra(GFP/+). These mice display a range of severe phenotypes including spina bifida, lung emphysema, abnormal meninges and neuronal over-migration in the cerebral cortex. We focused our analysis on the central nervous system (CNS), where PDGF-C was identified as a critical factor for the formation of meninges and assembly of the glia limitans basement membrane. We also present expression data on Pdgfa, Pdgfc and Pdgfra in the cerebral cortex and microarray data on cerebral meninges.
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| 10. |
- Andrae, Johanna, et al.
(författare)
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Characterization of Platelet-Derived Growth Factor-A Expression in Mouse Tissues Using a lacZ Knock-In Approach
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:8, s. e105477-
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Tidskriftsartikel (refereegranskat)abstract
- Expression of the platelet-derived growth factor A-chain gene (Pdgfa) occurs widely in the developing mouse, where it is mainly localized to various epithelial and neuronal structures. Until now, in situ mRNA hybridization (ISH) has been the only reliable method to identify Pdgfa expression in tissue sections or whole mount preparations. Validated protocols for in situ detection of PDGF-A protein by immunohistochemistry is lacking. In particular, this has hampered understanding of Pdgfa expression pattern in adult tissues, where ISH is technically challenging. Here, we report a gene targeted mouse Pdgfa allele, Pdgfa(ex4COIN), which is a combined conditional knockout and reporter allele. Cre-mediated inversion of the COIN cassette inactivates Pdgfa coding while simultaneously activating a beta-galactosidase (lacZ) reporter under endogenous Pdgfa transcription control. The generated Pdgfa(ex4COIN-INV-lacZ) allele can next be used to identify cells carrying a Pdgfa null allele, as well as to map endogenous Pdgfa expression. We evaluated the Pdgfa(ex4COIN-INV-lacZ) allele as a reporter for endogenous Pdgfa expression patterns in mouse embryos and adults. We conclude that the expression pattern of Pdgfa(ex4COIN-INV-lacZ) recapitulates known expression patterns of Pdgfa. We also report on novel embryonic and adult Pdgfa expression patterns in the mouse and discuss their implications for Pdgfa physiology.
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| 11. |
- Armulik, Annika, et al.
(författare)
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Pericytes regulate the blood-brain barrier
- 2010
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Ingår i: NATURE. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 468:7323
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Tidskriftsartikel (refereegranskat)
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| 12. |
- Bernier-Latmani, Jeremiah, et al.
(författare)
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ADAMTS18+ villus tip telocytes maintain a polarized VEGFA signaling domain and fenestrations in nutrient-absorbing intestinal blood vessels
- 2022
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- The small intestinal villus tip is the first point of contact for lumen-derived substances including nutrients and microbial products. Electron microscopy studies from the early 1970s uncovered unusual spatial organization of small intestinal villus tip blood vessels: their exterior, epithelial-facing side is fenestrated, while the side facing the villus stroma is non-fenestrated, covered by pericytes and harbors endothelial nuclei. Such organization optimizes the absorption process, however the molecular mechanisms maintaining this highly specialized structure remain unclear. Here we report that perivascular LGR5(+) villus tip telocytes (VTTs) are necessary for maintenance of villus tip endothelial cell polarization and fenestration by sequestering VEGFA signaling. Mechanistically, unique VTT expression of the protease ADAMTS18 is necessary for VEGFA signaling sequestration through limiting fibronectin accumulation. Therefore, we propose a model in which LGR5(+) ADAMTS18(+) telocytes are necessary to maintain a "just-right" level and location of VEGFA signaling in intestinal villus blood vasculature to ensure on one hand the presence of sufficient endothelial fenestrae, while avoiding excessive leakiness of the vessels and destabilization of villus tip epithelial structures. The molecular mechanisms ensuring the specialized structure of small intestinal villus tip blood vessels are incompletely understood. Here the authors show that ADAMTS18(+) telocytes maintain a "just-right" level and location of VEGFA signaling on intestinal villus blood vessels, thereby ensuring the presence of endothelial fenestrae for nutrient absorption, while avoiding excessive leakiness and destabilization of villus tip epithelial structures.
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| 13. |
- Bondjers, Cecilia, 1974, et al.
(författare)
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Microarray analysis of blood microvessels from PDGF-B and PDGF-Rbeta mutant mice identifies novel markers for brain pericytes.
- 2006
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Ingår i: The FASEB journal : official publication of the Federation of American Societies for Experimental Biology. - : Wiley. - 1530-6860. ; 20:10, s. 1703-5
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Tidskriftsartikel (refereegranskat)abstract
- Normal blood microvessels are lined by pericytes, which contribute to microvessel development and stability through mechanisms that are poorly understood. Pericyte deficiency has been implicated in the pathogenesis of microvascular abnormalities associated with diabetes and tumors. However, the unambiguous identification of pericytes is still a problem because of cellular heterogeneity and few available molecular markers. Here we describe an approach to identify pericyte markers based on transcription profiling of pericyte-deficient brain microvessels isolated from platelet-derived growth factor (PDGF-B)-/- and PDGF beta receptor (PDGFRbeta)-/- mouse mutants. The approach was validated by the identification of known pericyte markers among the most down-regulated genes in PDGF-B-/- and PDGFRbeta-/- microvessels. Of candidates for novel pericyte markers, we selected ATP-sensitive potassium-channel Kir6.1 (also known as Kcnj8) and sulfonylurea receptor 2, (SUR2, also known as Abcc9), both part of the same channel complex, as well as delta homologue 1 (DLK1) for in situ hybridization, which demonstrated their specific expression in brain pericytes of mouse embryos. We also show that Kir6.1 is highly expressed in pericytes in brain but undetectable in pericytes in skin and heart. The three new brain pericyte markers are signaling molecules implicated in ion transport and intercellular signaling, potentially opening new windows on pericyte function in brain microvessels.
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| 14. |
- Chen, Rui, et al.
(författare)
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Prostate Specific Antigen and Prostate Cancer in Chinese Men Undergoing Initial Prostate Biopsies Compared with Western Cohorts
- 2017
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Ingår i: Journal of Urology. - : Ovid Technologies (Wolters Kluwer Health). - 0022-5347 .- 1527-3792. ; 197:1, s. 90-96
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Tidskriftsartikel (refereegranskat)abstract
- Purpose We determined the characteristics of Chinese men undergoing initial prostate biopsy and evaluated the relationship between prostate specific antigen levels and prostate cancer/high grade prostate cancer detection in a large Chinese multicenter cohort. Materials and Methods This retrospective study included 13,904 urology outpatients who had undergone biopsy for the indications of prostate specific antigen greater than 4.0 ng/ml or prostate specific antigen less than 4.0 ng/ml but with abnormal digital rectal examination results. The prostate specific antigen measurements were performed in accordance with the standard procedures at the respective institutions. The type of assay used was documented and recalibrated to the WHO standard. Results The incidence of prostate cancer and high grade prostate cancer was lower in the Chinese cohort than the Western cohorts at any given prostate specific antigen level. Around 25% of patients with a prostate specific antigen of 4.0 to 10.0 ng/ml were found to have prostate cancer compared to approximately 40% in U.S. clinical practice. Moreover, the risk curves were generally flatter than those of the Western cohorts, that is risk did not increase as rapidly with higher prostate specific antigen. Conclusions The relationship between prostate specific antigen and prostate cancer risk differs importantly between Chinese and Western populations, with an overall lower risk in the Chinese cohort. Further research should explore whether environmental or genetic differences explain these findings or whether they result from unmeasured differences in screening or benign prostate disease. Caution is required for the implementation of prostate cancer clinical decision rules or prediction models for men in China or other Asian countries with similar genetic and environmental backgrounds.
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| 15. |
- De La Fuente, Alerie Guzman, et al.
(författare)
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Pericytes Stimulate Oligodendrocyte Progenitor Cell Differentiation during CNS Remyelination
- 2017
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Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 20:8, s. 1755-1764
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Tidskriftsartikel (refereegranskat)abstract
- The role of the neurovascular niche in CNS myelin regeneration is incompletely understood. Here, we show that, upon demyelination, CNS-resident pericytes (PCs) proliferate, and parenchymal non-vessel-associated PC-like cells (PLCs) rapidly develop. During remyelination, mature oligodendrocytes were found in close proximity to PCs. In Pdgfb(ret/ret) mice, which have reduced PC numbers, oligodendrocyte progenitor cell (OPC) differentiation was delayed, although remyelination proceeded to completion. PC-conditioned medium accelerated and enhanced OPC differentiation in vitro and increased the rate of remyelination in an ex vivo cerebellar slice model of demyelination. We identified Lama2 as a PC-derived factor that promotes OPC differentiation. Thus, the functional role of PCs is not restricted to vascular homeostasis but includes the modulation of adult CNS progenitor cells involved in regeneration.
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| 16. |
- Deng, Xiangyi, et al.
(författare)
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ECO : An Integrated Gene Expression Omnibus for Mouse Endothelial Cells In Vivo
- 2022
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Ingår i: Frontiers in Genetics. - : Frontiers Media S.A.. - 1664-8021. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Endothelial cell (EC) plays critical roles in vascular physiological and pathological processes. With the development of high-throughput technologies, transcriptomics analysis of EC has increased dramatically and a large amount of informative data have been generated. The dynamic patterns of gene expression in ECs under various conditions were revealed. Unfortunately, due to the lack of bioinformatics infrastructures, reuse of these large-scale datasets is challenging for many scientists. Here, by systematic re-analyzing, integrating, and standardizing of 203 RNA sequencing samples from freshly isolated mouse ECs under 71 conditions, we constructed an integrated mouse EC gene expression omnibus (ECO). The ECO database enables one-click retrieval of endothelial expression profiles from different organs under different conditions including disease models, genetic modifications, and clinically relevant treatments in vivo. The EC expression profiles are visualized with user-friendly bar-plots. It also provides a convenient search tool for co-expressed genes. ECO facilitates endothelial research with an integrated tool and resource for transcriptome analysis. The ECO database is freely available at https://heomics. shinyapps.io/ecodb/.
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| 17. |
- Dias, Mariana Castro, et al.
(författare)
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Claudin-3-deficient C57BL/6J mice display intact brain barriers
- 2019
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- The tight junction protein claudin-3 has been identified as a transcriptional target of the Wnt/beta-catenin signaling pathway regulating blood-brain barrier (BBB) maturation. In neurological disorders loss of claudin-3 immunostaining is observed at the compromised BBB and blood-cerebrospinal fluid barrier (BCSFB). Although these observations support a central role of claudin-3 in regulating brain barriers' tight junction integrity, expression of claudin-3 at the brain barriers has remained a matter of debate. This prompted us to establish claudin-3-/-C57BL/6J mice to study the role of claudin-3 in brain barrier integrity in health and neuroinflammation. Bulk and single cell RNA sequencing and direct comparative qRT-PCR analysis of brain microvascular samples from WT and claudin-3-/- mice show beyond doubt that brain endothelial cells do not express claudin-3 mRNA. Detection of claudin-3 protein at the BBB in vivo and in vitro is rather due to junctional reactivity of anti-claudin-3 antibodies to an unknown antigen still detected in claudin-3-/- brain endothelium. We confirm expression and junctional localization of claudin-3 at the BCSFB of the choroid plexus. Our study clarifies that claudin-3 is not expressed at the BBB and shows that absence of claudin-3 does not impair brain barrier function during health and neuroinflammation in C57BL/6J mice.
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| 18. |
- Egana, I, et al.
(författare)
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Female mice lacking Pald1 exhibit endothelial cell apoptosis and emphysema
- 2017
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Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1, s. 15453-
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Tidskriftsartikel (refereegranskat)abstract
- Paladin (Pald1, mKIAA1274 or x99384) was identified in screens for vascular-specific genes and is a putative phosphatase. Paladin has also been proposed to be involved in various biological processes such as insulin signaling, innate immunity and neural crest migration. To determine the role of paladin we have now characterized the Pald1 knock-out mouse in a broad array of behavioral, physiological and biochemical tests. Here, we show that female, but not male, Pald1 heterozygous and homozygous knock-out mice display an emphysema-like histology with increased alveolar air spaces and impaired lung function with an obstructive phenotype. In contrast to many other tissues where Pald1 is restricted to the vascular compartment, Pald1 is expressed in both the epithelial and mesenchymal compartments of the postnatal lung. However, in Pald1 knock-out females, there is a specific increase in apoptosis and proliferation of endothelial cells, but not in non-endothelial cells. This results in a transient reduction of endothelial cells in the maturing lung. Our data suggests that Pald1 is required during lung vascular development and for normal function of the developing and adult lung in a sex-specific manner. To our knowledge, this is the first report of a sex-specific effect on endothelial cell apoptosis.
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| 19. |
- Engelbrecht, Eric, et al.
(författare)
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Sphingosine 1-phosphate-regulated transcriptomes in heterogenous arterial and lymphatic endothelium of the aorta
- 2020
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Ingår i: eLIFE. - : ELIFE SCIENCES PUBLICATIONS LTD. - 2050-084X. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Despite the medical importance of G protein-coupled receptors (GPCRs), in vivo cellular heterogeneity of GPCR signaling and downstream transcriptional responses are not understood. We report the comprehensive characterization of transcriptomes (bulk and single-cell) and chromatin domains regulated by sphingosine 1-phosphate receptor-1 (S1PR1) in adult mouse aortic endothelial cells. First, S1PR1 regulates NF kappa B and nuclear glucocorticoid receptor pathways to suppress inflammation-related mRNAs. Second, S1PR1 signaling in the heterogenous endothelial cell (EC) subtypes occurs at spatially-distinct areas of the aorta. For example, a transcriptomically distinct arterial EC population at vascular branch points (aEC1) exhibits ligand-independent S1PR1/beta-arrestin coupling. In contrast, circulatory S1P-dependent S1PR1/beta-arrestin coupling was observed in non-branch point aEC2 cells that exhibit an inflammatory gene expression signature. Moreover, S1P/S1PR1 signaling regulates the expression of lymphangiogenic and inflammation-related transcripts in an adventitial lymphatic EC (LEC) population in a ligand-dependent manner. These insights add resolution to existing concepts of endothelial heterogeneity, GPCR signaling and S1P biology.
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| 20. |
- Falkevall, Annelie, et al.
(författare)
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Reducing VEGF-B Signaling Ameliorates Renal Lipotoxicity and Protects against Diabetic Kidney Disease
- 2017
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Ingår i: Cell Metabolism. - : Elsevier BV. - 1550-4131 .- 1932-7420. ; 25:3, s. 713-726
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Tidskriftsartikel (refereegranskat)abstract
- Diabetic kidney disease (DKD) is the most common cause of severe renal disease, and few treatment options are available today that prevent the progressive loss of renal function. DKD is characterized by altered glomerular filtration and proteinuria. A common observation in DKD is the presence of renal steatosis, but the mechanism(s) underlying this observation and to what extent they contribute to disease progression are unknown. Vascular endothelial growth factor B (VEGF-B) controls muscle lipid accumulation through regulation of endothelial fatty acid transport. Here, we demonstrate in experimental mouse models of DKD that renal VEGF-B expression correlates with the severity of disease. Inhibiting VEGF-B signaling in DKD mouse models reduces renal lipotoxicity, re-sensitizes podocytes to insulin signaling, inhibits the development of DKD-associated pathologies, and prevents renal dysfunction. Further, we show that elevated VEGF-B levels are found in patients with DKD, suggesting that VEGF-B antagonism represents a novel approach to treat DKD.
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| 21. |
- Fan, Yuhang, et al.
(författare)
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Expansion spatial transcriptomics
- 2023
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Ingår i: Nature Methods. - : Springer Nature. - 1548-7091 .- 1548-7105. ; 20:8, s. 1179-1182
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Tidskriftsartikel (refereegranskat)abstract
- Capture array-based spatial transcriptomics methods have been widely used to resolve gene expression in tissues; however, their spatial resolution is limited by the density of the array. Here we present expansion spatial transcriptomics to overcome this limitation by clearing and expanding tissue prior to capturing the entire polyadenylated transcriptome with an enhanced protocol. This approach enables us to achieve higher spatial resolution while retaining high library quality, which we demonstrate using mouse brain samples.
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| 22. |
- Gillnäs, Sara, et al.
(författare)
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Severe cerebellar malformations in mutant mice demonstrate a role for PDGF-C/PDGFR alpha signalling in cerebellar development
- 2022
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Ingår i: BIOLOGY OPEN. - : COMPANY BIOLOGISTS LTD. - 2046-6390. ; 11:8
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Tidskriftsartikel (refereegranskat)abstract
- Formation of the mouse cerebellum is initiated in the embryo and continues for a few weeks after birth. Double-mutant mice lacking platelet-derived growth factor C (PDGF-C) and that are heterozygous for platelet-derived growth factor receptor alpha (Pdgfc(-/-); Pdgfra(GFP/+)) develop cerebellar hypoplasia and malformation with loss of cerebellar lobes in the posterior vermis. This phenotype is similar to those observed in Foxc1 mutant mice and in a human neuroimaging pattern called Dandy Walker malformation. Pdgfc-Pdgfra mutant mice also display ependymal denudation in the fourth ventricle and gene expression changes in cerebellar meninges, which coincide with the first visible signs of cerebellar malformation. Here, we show that PDGF-C/PDGFR alpha signalling is a critical component in the network of molecular and cellular interactions that take place between the developing meninges and neural tissues, and which are required to build a fully functioning cerebellum.
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| 23. |
- Gordon, Emma J., et al.
(författare)
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The endothelial adaptor molecule TSAd is required for VEGF-induced angiogenic sprouting through junctional c-Src activation
- 2016
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Ingår i: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 9:437
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Tidskriftsartikel (refereegranskat)abstract
- Activation of vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) by VEGF binding is critical for vascular morphogenesis. In addition, VEGF disrupts the endothelial barrier by triggering the phosphorylation and turnover of the junctional molecule VE-cadherin, a process mediated by the VEGFR2 downstream effectors T cell-specific adaptor (TSAd) and the tyrosine kinase c-Src. We investigated whether the VEGFR2-TSAd-c-Src pathway was required for angiogenic sprouting. Indeed, Tsad-deficient embryoid bodies failed to sprout in response to VEGF. Tsad-deficient mice displayed impaired angiogenesis specifically during tracheal vessel development, but not during retinal vasculogenesis, and in VEGF-loaded Matrigel plugs, but not in those loaded with FGF. The SH2 and proline-rich domains of TSAd bridged VEGFR2 and c-Src, and this bridging was critical for the localization of activated c-Src to endothelial junctions and elongation of the growing sprout, but not for selection of the tip cell. These results revealed that vascular sprouting and permeability are both controlled through the VEGFR2-TSAd-c-Src signaling pathway in a subset of tissues, which may be useful in developing strategies to control tissue-specific pathological angiogenesis.
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| 24. |
- Gouveia, Maria Leonor Seguardo, et al.
(författare)
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Lung developmental arrest caused by PDGF-A deletion : consequences for the adult mouse lung
- 2020
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Ingår i: American Journal of Physiology - Lung cellular and Molecular Physiology. - : AMER PHYSIOLOGICAL SOC. - 1040-0605 .- 1522-1504. ; 318:4, s. L831-L843
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Tidskriftsartikel (refereegranskat)abstract
- PDGF-A is a key contributor to lung development in mice. Its expression is needed for secondary septation of the alveoli and deletion of the gene leads to abnormally enlarged alveolar air spaces in mice. In humans, the same phenotype is the hallmark of bronchopulmonary dysplasia (BPD), a disease that affects premature babies and may have long lasting consequences in adulthood. So far, the knowledge regarding adult effects of developmental arrest in the lung is limited. This is attributable to few follow-up studies of BPD survivors and lack of good experimental models that could help predict the outcomes of this early age disease for the adult individual. In this study, we used the constitutive lung-specific Pdgfa deletion mouse model to analyze the consequences of developmental lung defects in adult mice. We assessed lung morphology, physiology, cellular content, ECM composition and proteomics data in mature mice, that perinatally exhibited lungs with a BPD-like morphology. Histological and physiological analyses both revealed that enlarged alveolar air spaces remained until adulthood, resulting in higher lung compliance and higher respiratory volume in knockout mice. Still, no or only small differences were seen in cellular, ECM and protein content when comparing knockout and control mice. Taken together, our results indicate that Pdgfa deletion-induced lung developmental arrest has consequences for the adult lung at the morphological and functional level. In addition, these mice can reach adulthood with a BPD-like phenotype, which makes them a robust model to further investigate the pathophysiological progression of the disease and test putative regenerative therapies.
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| 25. |
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| 26. |
- Hariharan, Ashwini, et al.
(författare)
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The Ion Channel and GPCR Toolkit of Brain Capillary Pericytes
- 2020
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Ingår i: Frontiers in Cellular Neuroscience. - LAUSANNE, SWITZERLAND : Frontiers Media SA. - 1662-5102. ; 14
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Forskningsöversikt (refereegranskat)abstract
- Brain pericytes reside on the abluminal surface of capillaries, and their processes cover similar to 90% of the length of the capillary bed. These cells were first described almost 150 years ago (Eberth, 1871; Rouget, 1873) and have been the subject of intense experimental scrutiny in recent years, but their physiological roles remain uncertain and little is known of the complement of signaling elements that they employ to carry out their functions. In this review, we synthesize functional data with single-cell RNAseq screens to explore the ion channel and G protein-coupled receptor (GPCR) toolkit of mesh and thin-strand pericytes of the brain, with the aim of providing a framework for deeper explorations of the molecular mechanisms that govern pericyte physiology. We argue that their complement of channels and receptors ideally positions capillary pericytes to play a central role in adapting blood flow to meet the challenge of satisfying neuronal energy requirements from deep within the capillary bed, by enabling dynamic regulation of their membrane potential to influence the electrical output of the cell. In particular, we outline how genetic and functional evidence suggest an important role for G(s)-coupled GPCRs and ATP-sensitive potassium (K-ATP) channels in this context. We put forth a predictive model for long-range hyperpolarizing electrical signaling from pericytes to upstream arterioles, and detail the TRP and Ca2+ channels and G(q), G(i/o), and G(12/13) signaling processes that counterbalance this. We underscore critical questions that need to be addressed to further advance our understanding of the signaling topology of capillary pericytes, and how this contributes to their physiological roles and their dysfunction in disease.
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| 27. |
- He, Liqun
(författare)
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Analysis of kidney glomerular and microvascular transcriptomes
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Kidney glomeruli play a crucial role in the maintenance of body homeostasis. Many diseases attack the kidney function by primarily affecting glomeruli. However, the transcriptome profiles and the function of the glomerulus is poorly understood. Microvascular pericytes are multifunctional cells and they are actively involved in angiogenesis at different aspects. But shortage of molecular markers for pericyte has hampered the studies for its identification, origin and function. In order to explore the transcriptome of kidney glomeruli and microvascular pericytes, several genomics and bioinformatics approaches were applied. First, we constructed and large scale sequenced four Express Sequence Tag (EST) libraries generated from pure preparations of newborn and adult mouse glomeruli. EST sequence analysis produced direct expression profiles of kidney glomerulus and revealed glomerulus-specific expression patterns (GlomBase). By comparing the transcript abundance profiles in the glomerulus EST libraries with public whole kidney libraries, we identified 497 glomerulus-enriched mouse transcripts in the newborn and/or adult mouse glomerulus, eight of which were confirmed by individual experiments. The glomerular ESTs were printed on glass slides in order to generate cDNA microarrays with broad representation of glomerulus-expressed genes (GlomChip). Subsequently, by using GlomChip to compare the RNA samples from the glomerulus with non-glomerulus kidney tissues, we identified 357 mouse genes as glomerulus-enriched and some of them were individually studied in detail. Further, by combing the result from Affymetrix whole genome array study and published SAGE and Stanford cDNA array results, we did a meta analysis and merged the data into a catalogue of 1407 glomerulus-enriched genes. Based on this, a protein-protein interaction network in the glomerulus (GlomNet) was constructed. GlomChip was also applied to the analysis of the microvascular pericyte transcriptome. By comparing the expression profiles in microvascular fragments from wild-type and pericyte-deficient Pdgfb/Pdgfrb knockout mice, we identified 142 gene transcripts that were down-regulated in both mutants, which could be potential new pericyte markers. The transcript catalogues that we have generated provide information about the transcriptome profiles of the kidney glomerulus and the microvascular pericytes, and contribute new information about their function, physiology and disease. Also, GlomNet will contribute an integrated systematic understanding of the kidney glomerulus.
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| 28. |
- He, Liqun, et al.
(författare)
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Analysis of the brain mural cell transcriptome
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Pericytes, the mural cells of blood microvessels, regulate microvascular development and function and have been implicated in many brain diseases. However, due to a paucity of defining markers, pericyte identification and functional characterization remain ambiguous and data interpretation problematic. In mice carrying two transgenic reporters, Pdgfrb-eGFP and NG2-DsRed, we found that double-positive cells were vascular mural cells, while the single reporters marked additional, but non-overlapping, neuroglial cells. Double-positive cells were isolated by fluorescence-activated cell sorting (FACS) and analyzed by RNA sequencing. To reveal defining patterns of mural cell transcripts, we compared the RNA sequencing data with data from four previously published studies. The meta-analysis provided a conservative catalogue of 260 brain mural cell-enriched gene transcripts. We validated pericyte-specific expression of two novel markers, vitronectin (Vtn) and interferon-induced transmembrane protein 1 (Ifitm1), using fluorescent in situ hybridization and immunohistochemistry. We further analyzed signaling pathways and interaction networks of the pericyte-enriched genes in silico. This work provides novel insight into the molecular composition of brain mural cells. The reported gene catalogue facilitates identification of brain pericytes by providing numerous new candidate marker genes and is a rich source for new hypotheses for future studies of brain mural cell physiology and pathophysiology.
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| 29. |
- He, Liqun, et al.
(författare)
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Single-cell RNA sequencing of mouse brain and lung vascular and vessel-associated cell types
- 2018
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Ingår i: Scientific Data. - : NATURE PUBLISHING GROUP. - 2052-4463. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Vascular diseases are major causes of death, yet our understanding of the cellular constituents of blood vessels, including how differences in their gene expression profiles create diversity in vascular structure and function, is limited. In this paper, we describe a single-cell RNA sequencing (scRNA-seq) dataset that defines vascular and vessel-associated cell types and subtypes in mouse brain and lung. The dataset contains 3,436 single cell transcriptomes from mouse brain, which formed 15 distinct clusters corresponding to cell (sub) types, and another 1,504 single cell transcriptomes from mouse lung, which formed 17 cell clusters. In order to allow user-friendly access to our data, we constructed a searchable database (http://betsholtzlab.org/VascularSingleCells/database.html). Our dataset constitutes a comprehensive molecular atlas of vascular and vessel-associated cell types in the mouse brain and lung, and as such provides a strong foundation for future studies of vascular development and diseases.
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| 30. |
- He, Liqun, et al.
(författare)
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The glomerular transcriptome and a predicted protein-protein interaction network
- 2008
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Ingår i: Journal of the American Society of Nephrology. - 1046-6673 .- 1533-3450. ; 19:2, s. 260-268
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Tidskriftsartikel (refereegranskat)abstract
- To increase our understanding of the molecular composition of the kidney glomerulus, we performed a meta-analysis of available glomerular transcriptional profiles made from mouse and man using five different methodologies. We generated a combined catalogue of glomerulus-enriched genes that emerged from these different sources and then used this to construct a predicted protein-protein interaction network in the glomerulus (GlomNet). The combined glomerulus-enriched gene catalogue provides the most comprehensive picture of the molecular composition of the glomerulus currently available, and GlomNet contributes an integrative systems biology approach to the understanding of glomerular signaling networks that operate during development, function, and disease.
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| 31. |
- Henshall, Tanya L, et al.
(författare)
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Notch3 Is Necessary for Blood Vessel Integrity in the Central Nervous System
- 2015
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Ingår i: Arteriosclerosis, Thrombosis and Vascular Biology. - 1079-5642 .- 1524-4636. ; 35:2, s. 409-420
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Vascular smooth muscle cells (VSMC) are important for contraction, blood flow distribution, and regulation of blood vessel diameter, but to what extent they contribute to the integrity of blood vessels and blood-brain barrier function is less well understood. In this report, we explored the impact of the loss of VSMC in the Notch3(-/-) mouse on blood vessel integrity in the central nervous system.APPROACH AND RESULTS: Notch3(-/-) mice showed focal disruptions of the blood-brain barrier demonstrated by extravasation of tracers and accompanied by fibrin deposition in the retinal vasculature. This blood-brain barrier leakage was accompanied by a regionalized and patchy loss of VSMC, with VSMC gaps predominantly in arterial resistance vessels of larger caliber. The loss of VSMC appeared to be caused by progressive degeneration of VSMC resulting in a gradual loss of VSMC marker expression and a progressive acquisition of an aberrant VSMC phenotype closer to the gaps, followed by enhanced apoptosis and cellular disintegration in the gaps. Arterial VSMC were the only mural cell type that was morphologically affected, despite Notch3 being expressed also in pericytes. Transcriptome analysis of isolated brain microvessels revealed gene expression changes in Notch3(-/-) mice consistent with loss of arterial VSMC and presumably secondary transcriptional changes were observed in endothelial genes, which may explain the compromised vascular integrity.CONCLUSIONS: We demonstrate that Notch3 is important for survival of VSMC, and reveal a critical role for Notch3 and VSMC in blood vessel integrity and blood-brain barrier function in the mammalian vasculature.
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| 32. |
- Hernández Vásquez, Magda, et al.
(författare)
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Transcription factor FOXP2 is a flow-induced regulator of collecting lymphatic vessels
- 2021
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Ingår i: EMBO Journal. - : EMBO Press. - 0261-4189 .- 1460-2075. ; 40:12
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Tidskriftsartikel (refereegranskat)abstract
- The lymphatic system is composed of a hierarchical network of fluid absorbing lymphatic capillaries and transporting collecting vessels. Despite distinct functions and morphologies, molecular mechanisms that regulate the identity of the different vessel types are poorly understood. Through transcriptional analysis of murine dermal lymphatic endothelial cells (LECs), we identified Foxp2, a member of the FOXP family of transcription factors implicated in speech development, as a collecting vessel signature gene. FOXP2 expression was induced after initiation of lymph flow in vivo and upon shear stress on primary LECs in vitro. Loss of FOXC2, the major flow-responsive transcriptional regulator of lymphatic valve formation, abolished FOXP2 induction in vitro and in vivo. Genetic deletion of Foxp2 in mice using the endothelial-specific Tie2-Cre or the tamoxifen-inducible LEC-specific Prox1-CreERT2 line resulted in enlarged collecting vessels and defective valves characterized by loss of NFATc1 activity. Our results identify FOXP2 as a new flow-induced transcriptional regulator of collecting lymphatic vessel morphogenesis and highlight the existence of unique transcription factor codes in the establishment of vessel-type-specific endothelial cell identities.
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| 33. |
- Huang, Hua, 1986-, et al.
(författare)
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ELTD1-deletion reduces vascular abnormality and improves T-cell recruitment after PD-1 blockade in glioma.
- 2021
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Ingår i: Neuro-Oncology. - : Oxford University Press. - 1522-8517 .- 1523-5866. ; 24:3, s. 398-411
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Tumor vessels in glioma are molecularly and functionally abnormal, contributing to treatment resistance. Proteins differentially expressed in glioma vessels can change vessel phenotype and be targeted for therapy. ELTD1 (Adgrl4) is an orphan member of the adhesion G-protein-coupled receptor family upregulated in glioma vessels, and has been suggested as a potential therapeutic target. However, the role of ELTD1 in regulating vessel function in glioblastoma is poorly understood.METHODS: ELTD1 expression in human gliomas and its association with patient survival was determined using tissue microarrays and public databases. The role of ELTD1 in regulating tumor vessel phenotype was analyzed using orthotopic glioma models and ELTD1 -/- mice. Endothelial cells isolated from murine gliomas were transcriptionally profiled to determine differentially expressed genes and pathways. The consequence of ELTD1-deletion on glioma immunity was determined by treating tumor bearing mice with PD-1-blocking antibodies.RESULTS: ELTD1 levels were upregulated in human glioma vessels, increased with tumor malignancy, and were associated with poor patient survival. Progression of orthotopic gliomas was not affected by ELTD1-deletion, however, tumor vascular function was improved in ELTD1 -/- mice. Bioinformatic analysis of differentially expressed genes indicated increased inflammatory response and decreased proliferation in tumor endothelium in ELTD1 -/- mice. Consistent with an enhanced inflammatory response, ELTD1-deletion improved T-cell infiltration in GL261-bearing mice after PD-1 checkpoint blockade.CONCLUSION: Our data demonstrate that ELTD1 participates in inducing vascular dysfunction in glioma, and suggests that targeting of ELTD1 may normalize the vessels and improve the response to immunotherapy.
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| 34. |
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| 35. |
- Håkansson, Joakim, 1975, et al.
(författare)
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Neural cell adhesion molecule-deficient beta-cell tumorigenesis results in diminished extracellular matrix molecule expression and tumour cell-matrix adhesion
- 2005
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Ingår i: Tumour Biology. - : Springer Science and Business Media LLC. - 1010-4283 .- 1423-0380. ; 26:2, s. 103-112
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Tidskriftsartikel (refereegranskat)abstract
- To understand by which mechanism neural cell adhesion molecule (N-CAM) limits beta tumour cell disaggregation and dissemination, we searched for potential downstream genes of N-CAM during beta tumour cell progression by gene expression profiling. Here, we show that N-CAM-deficient beta-cell tumorigenesis is associated with changes in the expression of genes involved in cell-matrix adhesion and cytoskeletal dynamics, biological processes known to affect the invasive and metastatic behaviour of tumour cells. The extracellular matrix (ECM) molecules emerged as the primary target, i.e. N-CAM deficiency resulted in down-regulated mRNA expression of a broad range of ECM molecules. Consistent with this result, deficient deposition of major ECM stromal components, such as fibronectin, laminin 1 and collagen IV, was observed. Moreover, N-CAM-deficient tumour cells displayed defective matrix adhesion. These results offer a potential mechanism for tumour cell disaggregation during N-CAM-deficient beta tumour cell progression. Prospective consequences of these findings for the role of N-CAM in beta tumour cell dissemination are discussed.
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| 36. |
- Ishikawa, Takahiro, et al.
(författare)
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A novel podocyte protein, R3h domain containing-like, inhibits TGF-β-induced p38 MAPK and regulates the structure of podocytes and glomerular basement membrane
- 2021
-
Ingår i: Journal of Molecular Medicine. - : Springer Science and Business Media LLC. - 0946-2716 .- 1432-1440. ; 99:6, s. 859-876
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Tidskriftsartikel (refereegranskat)abstract
- Not only in kidney glomerular physiological function but also glomerular pathology especially in diabetic condition, glomerular podocytes play pivotal roles. Therefore, it is important to increase our knowledge about the genes and proteins expressed in podocytes. Recently, we have identified a novel podocyte-expressed gene, R3h domain containing-like (R3hdml) and analyzed its function in vivo as well as in vitro. Transforming growth factor-β (TGF-β) signaling regulated the expression of R3hdml. And R3hdml inhibited p38 mitogen-activated protein kinase phosphorylation, which was induced by TGF-β, leading to the amelioration of podocyte apoptosis. Furthermore, a lack of R3hdml in mice significantly worsened glomerular function in streptozotocin (STZ)-induced diabetes, while overexpression of R3hdml ameliorated albuminuria in STZ-induced diabetes. Our results surmise that the functional analyses of R3hdml may lead to the development of novel therapeutic strategies for diabetic nephropathy in the future.
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| 37. |
- Jiao, Xiang, et al.
(författare)
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Structural Alterations from Multiple Displacement Amplification of a Human Genome Revealed by Mate-Pair Sequencing
- 2011
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:7, s. e22250-
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Tidskriftsartikel (refereegranskat)abstract
- Comprehensive identification of the acquired mutations that cause common cancers will require genomic analyses of large sets of tumor samples. Typically, the tissue material available from tumor specimens is limited, which creates a demand for accurate template amplification. We therefore evaluated whether phi29-mediated whole genome amplification introduces false positive structural mutations by massive mate-pair sequencing of a normal human genome before and after such amplification. Multiple displacement amplification led to a decrease in clone coverage and an increase by two orders of magnitude in the prevalence of inversions, but did not increase the prevalence of translocations. While multiple strand displacement amplification may find uses in translocation analyses, it is likely that alternative amplification strategies need to be developed to meet the demands of cancer genomics.
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| 38. |
- Kalén, Mattias, et al.
(författare)
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Combination of reverse and chemical genetic screens reveals angiogenesis inhibitors and targets.
- 2009
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Ingår i: Chemistry & biology. - : Elsevier BV. - 1879-1301 .- 1074-5521. ; 16:4, s. 432-41
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Tidskriftsartikel (refereegranskat)abstract
- We combined reverse and chemical genetics to identify targets and compounds modulating blood vessel development. Through transcript profiling in mice, we identified 150 potentially druggable microvessel-enriched gene products. Orthologs of 50 of these were knocked down in a reverse genetic screen in zebrafish, demonstrating that 16 were necessary for developmental angiogenesis. In parallel, 1280 pharmacologically active compounds were screened in a human cell-based assay, identifying 28 compounds selectively inhibiting endothelial sprouting. Several links were revealed between the results of the reverse and chemical genetic screens, including the serine/threonine (S/T) phosphatases ppp1ca, ppp1cc, and ppp4c and an inhibitor of this gene family; Endothall. Our results suggest that the combination of reverse and chemical genetic screens, in vertebrates, is an efficient strategy for the identification of drug targets and compounds that modulate complex biological systems, such as angiogenesis.
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| 39. |
- Kundu, Snehangshu, et al.
(författare)
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Common and mutation specific phenotypes of KRAS and BRAF mutations in colorectal cancer cells revealed by integrative -omics analysis
- 2021
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Ingår i: Journal of Experimental & Clinical Cancer Research. - : BioMed Central (BMC). - 1756-9966. ; 40
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Tidskriftsartikel (refereegranskat)abstract
- Background: Genes in the Ras pathway have somatic mutations in at least 60 % of colorectal cancers. Despite activating the same pathway, the BRAF V600E mutation and the prevalent mutations in codon 12 and 13 of KRAS have all been linked to different clinical outcomes, but the molecular mechanisms behind these differences largely remain to be clarified.Methods: To characterize the similarities and differences between common activating KRAS mutations and between KRAS and BRAF mutations, we used genome editing to engineer KRAS G12C/D/V and G13D mutations in colorectal cancer cells that had their mutant BRAF V600E allele removed and subjected them to transcriptome sequencing, global proteomics and metabolomics analyses.Results: By intersecting differentially expressed genes, proteins and metabolites, we uncovered (i) two-fold more regulated genes and proteins when comparing KRAS to BRAF mutant cells to those lacking Ras pathway mutation, (ii) five differentially expressed proteins in KRAS mutants compared to cells lacking Ras pathway mutation (IFI16, S100A10, CD44, GLRX and AHNAK2) and 6 (CRABP2, FLNA, NXN, LCP1, S100A10 and S100A2) compared to BRAF mutant cells, (iii) 19 proteins expressed differentially in a KRAS mutation specific manner versus BRAF V600E cells, (iv) regulation of the Integrin Linked Kinase pathway by KRAS but not BRAF mutation, (v) regulation of amino acid metabolism, particularly of the tyrosine, histidine, arginine and proline pathways, the urea cycle and purine metabolism by Ras pathway mutations, (vi) increased free carnitine in KRAS and BRAF mutant RKO cells.Conclusions: This comprehensive integrative -omics analysis confirms known and adds novel genes, proteins and metabolic pathways regulated by mutant KRAS and BRAF signaling in colorectal cancer. The results from the new model systems presented here can inform future development of diagnostic and therapeutic approaches targeting tumors with KRAS and BRAF mutations.
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| 40. |
- Kundu, Snehangshu, et al.
(författare)
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Linking FOXO3, NCOA3, and TCF7L2 to Ras pathway phenotypes through a genome-wide forward genetic screen in human colorectal cancer cells
- 2018
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Ingår i: Genome Medicine. - : Springer Science and Business Media LLC. - 1756-994X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Background:The Ras pathway genes KRAS, BRAF, or ERBBs have somatic mutations in similar to 60% of human colorectal carcinomas. At present, it is unknown whether the remaining cases lack mutations activating the Ras pathway or whether they have acquired mutations in genes hitherto unknown to belong to the pathway.Methods:To address the second possibility and extend the compendium of Ras pathway genes, we used genome-wide transposon mutagenesis of two human colorectal cancer cell systems deprived of their activating KRAS or BRAF allele to identify genes enabling growth in low glucose, a Ras pathway phenotype, when targeted.Results:Of the 163 recurrently targeted genes in the two different genetic backgrounds, one-third were known cancer genes and one-fifth had links to the EGFR/Ras/MAPK pathway. When compared to cancer genome sequencing datasets, nine genes also mutated in human colorectal cancers were identified. Among these, stable knockdown of FOXO3, NCOA3, and TCF7L2 restored growth in low glucose but reduced MEK/MAPK phosphorylation, reduced anchorage-independent growth, and modulated expressions of GLUT1 and Ras pathway related proteins. Knockdown of NCOA3 and FOXO3 significantly decreased the sensitivity to cetuximab of KRAS mutant but not wild-type cells.Conclusions:This work establishes a proof-of-concept that human cell-based genome-wide forward genetic screens can assign genes to pathways with clinical importance in human colorectal cancer.
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| 41. |
- Kurtyka, Magdalena, et al.
(författare)
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The solute carrier SLC7A1 may act as a protein transporter at the blood-brain barrier
- 2024
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Ingår i: European Journal of Cell Biology. - : Elsevier. - 0171-9335 .- 1618-1298. ; 103:2
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Tidskriftsartikel (refereegranskat)abstract
- Despite extensive research, targeted delivery of substances to the brain still poses a great challenge due to the selectivity of the blood -brain barrier (BBB). Most molecules require either carrier- or receptor -mediated transport systems to reach the central nervous system (CNS). These transport systems form attractive routes for the delivery of therapeutics into the CNS, yet the number of known brain endothelium -enriched receptors allowing the transport of large molecules into the brain is scarce. Therefore, to identify novel BBB targets, we combined transcriptomic analysis of human and murine brain endothelium and performed a complex screening of BBBenriched genes according to established selection criteria. As a result, we propose the high -affinity cationic amino acid transporter 1 (SLC7A1) as a novel candidate for transport of large molecules across the BBB. Using RNA sequencing and in situ hybridization assays, we demonstrated elevated SLC7A1 gene expression in both human and mouse brain endothelium. Moreover, we confirmed SLC7A1 protein expression in brain vasculature of both young and aged mice. To assess the potential of SLC7A1 as a transporter for larger proteins, we performed internalization and transcytosis studies using a radiolabelled or fluorophore-labelled anti-SLC7A1 antibody. Our results showed that SLC7A1 internalised a SLC7A1-specific antibody in human colorectal carcinoma (HCT116) cells. Moreover, transcytosis studies in both immortalised human brain endothelial (hCMEC/D3) cells and primary mouse brain endothelial cells clearly demonstrated that SLC7A1 effectively transported the SLC7A1specific antibody from luminal to abluminal side. Therefore, here in this study, we present for the first time the SLC7A1 as a novel candidate for transport of larger molecules across the BBB.
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| 42. |
- Larsson, Chatarina, et al.
(författare)
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DIP2C regulates expression of the tumor suppressor gene CDKN2A
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The disco-interacting protein 2 homolog C (DIP2C) gene is an uncharacterized candidatebreast and lung cancer gene. The gene contains a DMAP1 binding domain, pointing topotential involvement in DNMT1-dependent methylation. To study the role of DIP2C intumor development, we engineered human DIP2C knockout cell systems by rAAV-mediatedgene targeting. Homo- and heterozygous RKO DIP2C knockout cells displayed enlarged cellsand growth retardation. This phenotype was most pronounced in DIP2C-/- knockouts, andthese cells also displayed a significant decrease in DIP2C mRNA levels. RNA sequencingrevealed 780 genes affected by the loss of DIP2C, including the cellular senescence markerP16INK4a. Functional annotation of the regulated genes shows enrichment of genes involvedwith cell death processes, cell structure and motility. Furthermore, KEGG pathway analysisshows association of 19 genes with pathways in cancer. In conclusion, the phenotypic dataand expression changes induced by loss of DIP2C indicate that the gene function may beimportant for several biological processes implicated in cancer, and that loss of gene functionmay be a trigger of cellular senescence.
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| 43. |
- Larsson, Chatarina, 1979-, et al.
(författare)
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Loss of DIP2C in RKO cells stimulates changes in DNA methylation and epithelial-mesenchymal transition
- 2017
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Ingår i: BMC Cancer. - : BIOMED CENTRAL LTD. - 1471-2407. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- Background: The disco-interacting protein 2 homolog C (DIP2C) gene is an uncharacterized gene found mutated in a subset of breast and lung cancers. To understand the role of DIP2C in tumour development we studied the gene in human cancer cells.Methods: We engineered human DIP2C knockout cells by genome editing in cancer cells. The growth properties of the engineered cells were characterised and transcriptome and methylation analyses were carried out to identify pathways deregulated by inactivation of DIP2C. Effects on cell death pathways and epithelial-mesenchymal transition traits were studied based on the results from expression profiling.Results: Knockout of DIP2C in RKO cells resulted in cell enlargement and growth retardation. Expression profiling revealed 780 genes for which the expression level was affected by the loss of DIP2C, including the tumour-suppressor encoding CDKN2A gene, the epithelial-mesenchymal transition (EMT) regulator-encoding ZEB1, and CD44 and CD24 that encode breast cancer stem cell markers. Analysis of DNA methylation showed more than 30,000 sites affected by differential methylation, the majority of which were hypomethylated following loss of DIP2C. Changes in DNA methylation at promoter regions were strongly correlated to changes in gene expression, and genes involved with EMT and cell death were enriched among the differentially regulated genes. The DIP2C knockout cells had higher wound closing capacity and showed an increase in the proportion of cells positive for cellular senescence markers.Conclusions: Loss of DIP2C triggers substantial DNA methylation and gene expression changes, cellular senescence and epithelial-mesenchymal transition in cancer cells.
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| 44. |
- Larsson, Chatarina, 1979-, et al.
(författare)
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Restoration of KMT2C/MLL3 in human colorectal cancer cells reinforces genome-wide H3K4me1 profiles and influences cell growth and gene expression
- 2020
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Ingår i: Clinical Epigenetics. - : Springer Nature. - 1868-7083 .- 1868-7075. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Background The histone 3 lysine 4 (H3K4) monomethylase KMT2C is mutated across several cancer types; however, the effects of mutations on epigenome organization, gene expression, and cell growth are not clear. A frequently recurring mutation in colorectal cancer (CRC) with microsatellite instability is a single nucleotide deletion within the exon 38 poly-A(9) repeat (c.8390delA) which results in frameshift preceding the functional carboxy-terminal SET domain. To study effects ofKMT2Cexpression in CRC cells, we restored one allele to wild typeKMT2Cin the two CRC cell lines RKO and HCT116, which both are homozygous c.8390delA mutant. Results Gene editing resulted in increasedKMT2Cexpression, increased H3K4me1 levels, altered gene expression profiles, and subtle negative effects on cell growth, where higher dependence and stronger effects ofKMT2Cexpression were observed in RKO compared to HCT116 cells. Surprisingly, we found that the two RKO and HCT116 CRC cell lines have distinct baseline H3K4me1 epigenomic profiles. In RKO cells, a flatter genome-wide H3K4me1 profile was associated with more increased H3K4me1 deposition at enhancers, reduced cell growth, and more differential gene expression relative to HCT116 cells when KMT2C was restored. Profiling of H3K4me1 did not indicate a highly specific regulation of gene expression as KMT2C-induced H3K4me1 deposition was found globally and not at a specific enhancer sub-set in the engineered cells. Although we observed variation in differentially regulated gene sets between cell lines and individual clones, differentially expressed genes in both cell lines included genes linked to known cancer signaling pathways, estrogen response, hypoxia response, and aspects of immune system regulation. Conclusions Here, KMT2C restoration reduced CRC cell growth and reinforced genome-wide H3K4me1 deposition at enhancers; however, the effects varied depending upon the H3K4me1 status of KMT2C deficient cells. Results indicate that KMT2C inactivation may promote colorectal cancer development through transcriptional dysregulation in several pathways with known cancer relevance.
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| 45. |
- Lee, Heon-Woo, et al.
(författare)
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Endothelium-derived lactate is required for pericyte function and blood-brain barrier maintenance
- 2022
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Ingår i: EMBO Journal. - : EMBO Press. - 0261-4189 .- 1460-2075. ; 41:9
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Tidskriftsartikel (refereegranskat)abstract
- Endothelial cells differ from other cell types responsible for the formation of the vascular wall in their unusual reliance on glycolysis for most energy needs, which results in extensive production of lactate. We find that endothelium-derived lactate is taken up by pericytes, and contributes substantially to pericyte metabolism including energy generation and amino acid biosynthesis. Endothelial-pericyte proximity is required to facilitate the transport of endothelium-derived lactate into pericytes. Inhibition of lactate production in the endothelium by deletion of the glucose transporter-1 (GLUT1) in mice results in loss of pericyte coverage in the retina and brain vasculatures, leading to the blood-brain barrier breakdown and increased permeability. These abnormalities can be largely restored by oral lactate administration. Our studies demonstrate an unexpected link between endothelial and pericyte metabolisms and the role of endothelial lactate production in the maintenance of the blood-brain barrier integrity. In addition, our observations indicate that lactate supplementation could be a useful therapeutic approach for GLUT1 deficiency metabolic syndrome patients.
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| 46. |
- Lee, Heon-Woo, et al.
(författare)
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Role of Venous Endothelial Cells in Developmental and Pathologic Angiogenesis
- 2021
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Ingår i: Circulation. - : Lippincott Williams & Wilkins. - 0009-7322 .- 1524-4539. ; 144:16, s. 1308-1322
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Tidskriftsartikel (refereegranskat)abstract
- Background: Angiogenesis is a dynamic process that involves expansion of a preexisting vascular network that can occur in a number of physiological and pathological settings. Despite its importance, the origin of the new angiogenic vasculature is poorly defined. In particular, the primary subtype of endothelial cells (capillary, venous, arterial) driving this process remains undefined. Methods: Endothelial cells were fate-mapped with the use of genetic markers specific to arterial and capillary cells. In addition, we identified a novel venous endothelial marker gene (Gm5127) and used it to generate inducible venous endothelium-specific Cre and Dre driver mouse lines. Contributions of these various types of endothelial cells to angiogenesis were examined during normal postnatal development and in disease-specific setting. Results: Using a comprehensive set of endothelial subtype-specific inducible reporter mice, including tip, arterial, and venous endothelial reporter lines, we showed that venous endothelial cells are the primary endothelial subtype responsible for the expansion of an angiogenic vascular network. During physiological angiogenesis, venous endothelial cells proliferate, migrating against the blood flow and differentiating into tip, capillary, and arterial endothelial cells of the new vasculature. Using intravital 2-photon imaging, we observed venous endothelial cells migrating against the blood flow to form new blood vessels. Venous endothelial cell migration also plays a key role in pathological angiogenesis. This was observed both in formation of arteriovenous malformations in mice with inducible endothelium-specific Smad4 deletion mice and in pathological vessel growth seen in oxygen-induced retinopathy. Conclusions: Our studies establish that venous endothelial cells are the primary endothelial subtype responsible for normal expansion of vascular networks, formation of arteriovenous malformations, and pathological angiogenesis. These observations highlight the central role of the venous endothelium in normal development and disease pathogenesis.
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| 47. |
- Levin, A., et al.
(författare)
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The role of dendrin in IgA nephropathy
- 2023
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Ingår i: Nephrology Dialysis Transplantation. - : Oxford University Press (OUP). - 0931-0509 .- 1460-2385. ; 38:2, s. 311-321
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Tidskriftsartikel (refereegranskat)abstract
- Background Immunoglobulin A nephropathy (IgAN) and its systemic variant IgA vasculitis (IgAV) damage the glomeruli, resulting in proteinuria, hematuria and kidney impairment. Dendrin is a podocyte-specific protein suggested to be involved in the pathogenesis of IgAN. Upon cell injury, dendrin translocates from the slit diaphragm to the nucleus, where it is suggested to induce apoptosis and cytoskeletal changes, resulting in proteinuria and accelerated disease progression in mice. Here we investigated gene and protein expression of dendrin in relation to clinical and histopathological findings to further elucidate its role in IgAN/IgAV. Methods Glomerular gene expression was measured using microarray on 30 IgAN/IgAV patients, 5 patients with membranous nephropathy (MN) and 20 deceased kidney donors. Dendrin was spatially evaluated on kidney tissue sections by immunofluorescence (IF) staining (IgAN patients, n = 4; nephrectomized kidneys, n = 3) and semi-quantified by immunogold electron microscopy (IgAN/IgAV patients, n = 21; MN, n = 5; living kidney donors, n = 6). Histopathological grading was performed according to the Oxford and Banff classifications. Clinical data were collected at the time of biopsy and follow-up. Results Dendrin mRNA levels were higher (P = .01) in IgAN patients compared with MN patients and controls and most prominently in patients with preserved kidney function and fewer chronic histopathological changes. Whereas IF staining did not differ between groups, immunoelectron microscopy revealed that a higher relative nuclear dendrin concentration in IgAN patients was associated with a slower annual progression rate and milder histopathological changes. Conclusion Dendrin messenger RNA levels and relative nuclear protein concentrations are increased and associated with a more benign phenotype and progression in IgAN/IgAV patients.
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| 48. |
- Liu, Jianping, et al.
(författare)
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A human cell type similar to murine central nervous system perivascular fibroblasts
- 2021
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Ingår i: Experimental Cell Research. - : Elsevier. - 0014-4827 .- 1090-2422. ; 402:2
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Tidskriftsartikel (refereegranskat)abstract
- The brain vasculature has several specific features, one of them being the blood-brain barrier (BBB), which supports and protects the brain by allowing for the passage of oxygen and nutrients, while at the same time preventing passage of pathogens and toxins. The BBB also prevents efficient delivery of drugs to the brain, e.g. for treatment of brain tumors. In the murine brain, perivascular fibroblasts were recently identified as a novel potential constituent of the BBB. Here we present the existence of human cells that could be the equivalent to the murine brain perivascular fibroblasts. Using RNA sequencing, we show a similar transcriptomic profile of cultured human brain cells and murine perivascular fibroblasts. These data open up a window for new hypotheses on cell types involved in human CNS diseases.
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| 49. |
- Loganathan, Krishnapriya, et al.
(författare)
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Angiopoietin-1 deficiency increases renal capillary rarefaction and tubulointerstitial fibrosis in mice
- 2018
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Presence of tubulointerstitial fibrosis is predictive of progressive decline in kidney function, independent of its underlying cause. Injury to the renal microvasculature is a major factor in the progression of fibrosis and identification of factors that regulate endothelium in fibrosis is desirable as they might be candidate targets for treatment of kidney diseases. The current study investigates how loss of Angipoietin-1 (Angpt1), a ligand for endothelial tyrosine-kinase receptor Tek (also called Tie2), affects tubulointerstitial fibrosis and renal microvasculature. Inducible Angpt1 knockout mice were subjected to unilateral ureteral obstruction (UUO) to induce fibrosis, and kidneys were collected at different time points up to 10 days after obstruction. Staining for aSMA showed that Angpt1 deficient kidneys had significantly more fibrosis compared to wildtype mice 3, 6, and 10 days after UUO. Further investigation 3 days after UUO showed a significant increase of Col1a1 and vimentin in Angpt1 deficient mice, as well as increased gene expression of Tgfb1, Col1a1, Fn1, and CD44. Kidney injury molecule 1 (Kim1/Havcr1) was significantly more increased in Angpt1 deficient mice 1 and 3 days after UUO, suggesting a more severe injury early in the fibrotic process in Angpt1 deficient mice. Staining for endomucin showed that capillary rarefaction was evident 3 days after UUO and Angpt1 deficient mice had significantly less capillaries 6 and 10 days after UUO compared to UUO kidneys in wildtype mice. RNA sequencing revealed downregulation of several markers for endothelial cells 3 days after UUO, and that Angpt1 deficient mice had a further downregulation of Emcn, Plvap, Pecam1, Erg, and Tek. Our results suggest that loss of Angpt1 is central in capillary rarefaction and fibrogenesis and propose that manipulations to maintain Angpt1 levels may slow down fibrosis progression.
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| 50. |
- Masuda, Takahiro, et al.
(författare)
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Specification of CNS macrophage subsets occurs postnatally in defined niches
- 2022
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Ingår i: Nature. - : Springer Nature. - 0028-0836 .- 1476-4687. ; 604:7907, s. 740-
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Tidskriftsartikel (refereegranskat)abstract
- All tissue-resident macrophages of the central nervous system (CNS)-including parenchymal microglia, as well as CNS-associated macrophages (CAMs(1)) such as meningeal and perivascular macrophages(2-)(7)-are part of the CNS endogenous innate immune system that acts as the first line of defence during infections or trauma(2,8-10). It has been suggested that microglia and all subsets of CAMs are derived from prenatal cellular sources in the yolk sac that were defined as early erythromyeloid progenitors(11-15). However, the precise ontogenetic relationships, the underlying transcriptional programs and the molecular signals that drive the development of distinct CAM subsets in situ are poorly understood. Here we show, using fate-mapping systems, single-cell profiling and cell-specific mutants, that only meningeal macrophages and microglia share a common prenatal progenitor. By contrast, perivascular macrophages originate from perinatal meningeal macrophages only after birth in an integrin-dependent manner. The establishment of perivascular macrophages critically requires the presence of arterial vascular smooth muscle cells. Together, our data reveal a precisely timed process in distinct anatomical niches for the establishment of macrophage subsets in the CNS.
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