| 1. |
- Agarwal, Prasoon, et al.
(författare)
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Genome-wide profiling of histone H3 lysine 27 and lysine 4 trimethylation in multiple myeloma reveals the importance of Polycomb gene targeting and highlights EZH2 as a potential therapeutic target.
- 2016
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Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 7:6, s. 6809-6923
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Tidskriftsartikel (refereegranskat)abstract
- Multiple myeloma (MM) is a malignancy of the antibody-producing plasma cells. MM is a highly heterogeneous disease, which has hampered the identification of a common underlying mechanism for disease establishment as well as the development of targeted therapy. Here we present the first genome-wide profiling of histone H3 lysine 27 and lysine 4 trimethylation in MM patient samples, defining a common set of active H3K4me3-enriched genes and silent genes marked by H3K27me3 (H3K27me3 alone or bivalent) unique to primary MM cells, when compared to normal bone marrow plasma cells. Using this epigenome profile, we found increased silencing of H3K27me3 targets in MM patients at advanced stages of the disease, and the expression pattern of H3K27me3-marked genes correlated with poor patient survival. We also demonstrated that pharmacological inhibition of EZH2 had anti-myeloma effects in both MM cell lines and CD138+ MM patient cells. In addition, EZH2 inhibition decreased the global H3K27 methylation and induced apoptosis. Taken together, these data suggest an important role for the Polycomb repressive complex 2 (PRC2) in MM, and highlights the PRC2 component EZH2 as a potential therapeutic target in MM.
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| 2. |
- Cai, Huan, et al.
(författare)
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Critical role of Lama4 for hematopoiesis regeneration and acute myeloid leukemia progression
- 2022
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 139:20, s. 3040-3057
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Tidskriftsartikel (refereegranskat)abstract
- Impairment of normal hematopoiesis and leukemia progression are 2 well-linked processes during leukemia development and are controlled by the bone marrow (BM) niche. Extracellular matrix proteins, including laminin, are important BM niche components. However, their role in hematopoiesis regeneration and leukemia is unknown. Laminin α4 (Lama4), a major receptor-binding chain of several laminins, is altered in BM niches in mice with acute myeloid leukemia (AML). So far, the impact of Lama4 on leukemia progression remains unknown. We here report that Lama4 deletion in mice resulted in impaired hematopoiesis regeneration following irradiation-induced stress, which is accompanied by altered BM niche composition and inflammation. Importantly, in a transplantation-induced MLL-AF9 AML mouse model, we demonstrate accelerated AML progression and relapse in Lama4−/− mice. Upon AML exposure, Lama4−/− mesenchymal stem cells (MSCs) exhibited dramatic molecular alterations, including upregulation of inflammatory cytokines that favor AML growth. Lama4−/− MSCs displayed increased antioxidant activities and promoted AML stem cell proliferation and chemoresistance to cytarabine, which was accompanied by increased mitochondrial transfer from the MSCs to AML cells and reduced reactive oxygen species in AML cells in vitro. Similarly, we detected lower levels of reactive oxygen species in AML cells from Lama4−/− mice post–cytarabine treatment. Notably, LAMA4 inhibition or knockdown in human MSCs promoted human AML cell proliferation and chemoprotection. Together, our study for the first time demonstrates the critical role of Lama4 in impeding AML progression and chemoresistance. Targeting Lama4 signaling pathways may offer potential new therapeutic options for AML.
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| 3. |
- Dahlin, Joakim S., et al.
(författare)
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KIT signaling is dispensable for human mast cell progenitor development
- 2017
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 130:16, s. 1785-1794
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Tidskriftsartikel (refereegranskat)abstract
- Human hematopoietic progenitors are generally assumed to require stem cell factor (SCF) and KIT signaling during differentiation for the formation of mast cells. Imatinib treatment, which inhibits KIT signaling, depletes mast cells in vivo. Furthermore, the absence of SCF or imatinib treatment prevents progenitors from developing into mast cells in vitro. However, these observations do not mean that mast cell progenitors require SCF and KIT signaling throughout differentiation. Here, we demonstrate that circulating mast cell progenitors are present in patients undergoing imatinib treatment. In addition, we show that mast cell progenitors from peripheral blood survive, mature, and proliferate without SCF and KIT signaling in vitro. Contrary to the prevailing consensus, our results show that SCF and KIT signaling are dispensable for early mast cell development.
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| 4. |
- Dolinska, Monika, et al.
(författare)
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Characterization of Bone Marrow Niche in Chronic Myeloid Leukemia Patients Identifies CXCL14 as a New Therapeutic Option
- 2023
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 142:1, s. 73-89
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Tidskriftsartikel (refereegranskat)abstract
- Although tyrosine kinase inhibitors (TKIs) are effective in treating chronic myeloid leukemia (CML), they often fail to eradicate the leukemia-initiating stem cells (LSCs), causing disease persistence and relapse. Evidence indicates that LSC persistence may be because of bone marrow (BM) niche protection; however, little is known about the underlying mechanisms. Herein, we molecularly and functionally characterize BM niches in patients with CML at diagnosis and reveal the altered niche composition and function in these patients. Long-term culture initiating cell assay showed that the mesenchymal stem cells from patients with CML displayed an enhanced supporting capacity for normal and CML BM CD34+CD38- cells. Molecularly, RNA sequencing detected dysregulated cytokine and growth factor expression in the BM cellular niches of patients with CML. Among them, CXCL14 was lost in the BM cellular niches in contrast to its expression in healthy BM. Restoring CXCL14 significantly inhibited CML LSC maintenance and enhanced their response to imatinib in vitro, and CML engraftment in vivo in NSG-SGM3 mice. Importantly, CXCL14 treatment dramatically inhibited CML engraftment in patient-derived xenografted NSG-SGM3 mice, even to a greater degree than imatinib, and this inhibition persisted in patients with suboptimal TKI response. Mechanistically, CXCL14 upregulated inflammatory cytokine signaling but downregulated mTOR signaling and oxidative phosphorylation in CML LSCs. Together, we have discovered a suppressive role of CXCL14 in CML LSC growth. CXCL14 might offer a treatment option targeting CML LSCs.
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| 5. |
- Dolinska, Monika, et al.
(författare)
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Characterization of the bone marrow niche in patients with chronic myeloid leukemia identifies CXCL14 as a new therapeutic option
- 2023
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 142:1, s. 73-89
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Tidskriftsartikel (refereegranskat)abstract
- Although tyrosine kinase inhibitors (TKIs) are effective in treating chronic myeloid leukemia (CML), they often fail to eradicate the leukemia-initiating stem cells (LSCs), causing disease persistence and relapse. Evidence indicates that LSC persistence may be because of bone marrow (BM) niche protection; however, little is known about the underlying mechanisms. Herein, we molecularly and functionally characterize BM niches in patients with CML at diagnosis and reveal the altered niche composition and function in these patients. Long -term culture initiating cell assay showed that the mesenchymal stem cells from patients with CML displayed an enhanced supporting capacity for normal and CML BM CD34+CD38- cells. Molecularly, RNA sequencing detected dysregulated cytokine and growth factor expression in the BM cellular niches of patients with CML. Among them, CXCL14 was lost in the BM cellular niches in contrast to its expression in healthy BM. Restoring CXCL14 significantly inhibited CML LSC maintenance and enhanced their response to imatinib in vitro, and CML engraftment in vivo in NSG-SGM3 mice. Importantly, CXCL14 treatment dramatically inhibited CML engraftment in patient-derived xenografted NSG-SGM3 mice, even to a greater degree than imatinib, and this inhibition persisted in patients with suboptimal TKI response. Mechanistically, CXCL14 upregulated inflammatory cytokine signaling but downregulated mTOR signaling and oxidative phosphorylation in CML LSCs. Together, we have discovered a suppressive role of CXCL14 in CML LSC growth. CXCL14 might offer a treatment option targeting CML LSCs.
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| 6. |
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| 7. |
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| 8. |
- Grootens, Jennine, et al.
(författare)
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Deciphering the differentiation trajectory from hematopoietic stem cells to mast cells
- 2018
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Ingår i: Blood Advances. - : AMER SOC HEMATOLOGY. - 2473-9529 .- 2473-9537. ; 2:17, s. 2273-2281
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Forskningsöversikt (refereegranskat)abstract
- Hematopoietic stem cells differentiate into all types of blood cells, including peripheral tissue-resident mast cells. The early mast cell differentiation takes place in the bone marrow, after which the progenitor cells enter the circulation and mature once reaching their target organ. Early results from single-cell culture experiments and colony-forming assays have produced the classic hierarchical tree model of hematopoiesis. The introduction of high-throughput, single-cell RNA sequencing is now revolutionizing our understanding of the differentiation process, questioning the classic tree-based models. By integrating the results from early cell culture experiments with single-cell transcriptomics, we present a differentiation landscape model of hematopoiesis and discuss it with focus on mast cells. The review also describes how the hematologic neoplasm systemic mastocytosis can be used to model human hematopoiesis using naturally occurring cell barcoding by means of the common KIT D816V mutation.
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| 9. |
- Grootens, Jennine, et al.
(författare)
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Single-cell analysis reveals the KIT D816V mutation in haematopoietic stem and progenitor cells in systemic mastocytosis
- 2019
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Ingår i: EBioMedicine. - : ELSEVIER SCIENCE BV. - 2352-3964. ; 43, s. 150-158
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Tidskriftsartikel (refereegranskat)abstract
- Background: Systemic mastocytosis (SM) is a haematological disease characterised by organ infiltration by neoplastic mast cells. Almost all SM patients have a mutation in the gene encoding the tyrosine kinase receptor KIT causing a D816V substitution and autoactivation of the receptor. Mast cells and CD34(+) haematopoietic progenitors can carry the mutation: however, in which progenitor cell subset the mutation arises is unknown. We aimed to investigate the distribution of the D816V mutation in single mast cells and single haematopoietic stem and progenitor cells.Methods: Fluorescence-activated single-cell index sorting and KIT D816V mutation assessment were applied to analyse mast cells and >10,000 CD34(+) bone marrow progenitors across 10 haematopoietic progenitor subsets. In vitro assays verified cell-forming potential.Findings: We found that in SM 60-99% of the mast cells harboured the KIT D816V mutation. Despite increased frequencies of mast cells in SM patients compared with control subjects, the haematopoietic progenitor subset frequencies were comparable. Nevertheless, the mutation could be detected throughout the haematopoietic landscape of SM patients, from haematopoietic stem cells to more lineage-primed progenitors. In addition, we demonstrate that Fc epsilon RI+ bone marrow progenitors exhibit mast cell-forming potential, and we describe aberrant CD45RA expression on SM mast cells for the first time.Interpretation: The KIT D816V mutation arises in early haematopoietic stem and progenitor cells and the mutation frequency is approaching 100% in mature mast cells, which express the aberrant marker CD45RA.
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| 10. |
- Khalkar, Prajakta, et al.
(författare)
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Selenite and methylseleninic acid epigenetically affects distinct gene sets in myeloid leukemia : A genome wide epigenetic analysis
- 2018
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Ingår i: Free Radical Biology & Medicine. - : Elsevier BV. - 0891-5849 .- 1873-4596. ; 117, s. 247-257
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Tidskriftsartikel (refereegranskat)abstract
- Selenium compounds have emerged as promising chemotherapeutic agents with proposed epigenetic effects, however the mechanisms and downstream effects are yet to be studied. Here we assessed the effects of the inorganic selenium compound selenite and the organic form methylseleninic acid (MSA) in a leukemic cell line K562, on active (histone H3 lysine 9 acetylation, H3K9ac and histone H3 lysine 4 tri-methylation, H3K4me3) and repressive (histone H3 lysine 9 tri-methylation, H3K9me3) histone marks by Chromatin immunoprecipitation followed by DNA sequencing (ChIP-Seq). Both selenite and MSA had major effects on histone marks but the effects of MSA were more pronounced. Gene ontology analysis revealed that selenite affected genes involved in response to oxygen and hypoxia, whereas MSA affected distinct gene sets associated with cell adhesion and glucocorticoid receptors, also apparent by global gene expression analysis using RNA sequencing. The correlation to adhesion was functionally confirmed by a significantly weakened ability of MSA treated cells to attach to fibronectin and linked to decreased expression of integrin beta 1. A striking loss of cellular adhesion was also confirmed in primary patient AML cells. Recent strategies to enhance the cytotoxicity of chemotherapeutic drugs by disrupting the interaction between leukemic and stromal cells in the bone marrow are of increasing interest; and organic selenium compounds like MSA might be promising candidates. In conclusion, these results provide new insight on the mechanism of action of selenium compounds, and will be of value for the understanding, usage, and development of new selenium compounds as anticancer agents.
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| 11. |
- Levedahl, Kerstin, et al.
(författare)
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Living with systemic mastocytosis: balancing between vulnerability and resilience: A qualitative study
- 2022
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Ingår i: European Journal of Oncology Nursing. - : Elsevier. - 1462-3889 .- 1532-2122. ; 60
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Systemic mastocytosis (SM) is a rare group of hematological malignancies with heterogeneous symptoms from various organs, and overall survival ranges from normal for indolent SM (ISM) to 2–4 years for advanced SM subtypes (Adv SM). There is limited knowledge about the experience of living with SM. Thus, the purpose of this study was to describe the experiences of everyday life among persons diagnosed with ISM or Adv SM. Methods In this descriptive qualitative study, data were collected through purposive sampling and semi-structured interviews with 16 participants diagnosed with ISM (n = 9) or Adv SM (n = 7). Data were subsequently analysed with content analysis. Results Three main categories were identified. The persistent presence of the disease includes findings of how the symptoms affected the participants, how they handled its limitations, and the adaptions and medication management required. Struggling against ignorance illustrates contact with both healthcare professionals and strangers. The participants described being forced to be experts on SM due to a general lack of knowledge. An illness or wellness perspective encompasses the participants’ feelings of vulnerability and alienation, but also how various strategies were used to gain emotional control.Conclusions The disease has a considerable impact on everyday life, with constant efforts required to manage symptoms and medication side effects. The complexity and rarity of the disease complicated relationships with healthcare professionals and contributed to feelings of marginalisation and alienation. The participants described feeling vulnerable but used a multitude of strategies in their striving for resilience. Trusting relationships with healthcare professionals, family members and friends promoted a wellness perspective.
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| 12. |
- Lyberg, Katarina, et al.
(författare)
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Histone deacetylase inhibitor SAHA mediates mast cell death and epigenetic silencing of constitutively active D816V KIT in systemic mastocytosis.
- 2017
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Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 8:6, s. 9647-9659
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Tidskriftsartikel (refereegranskat)abstract
- Systemic mastocytosis (SM) is a clonal bone marrow disorder, where therapeutical options are limited. Over 90% of the patients carry the D816V point mutation in the KIT receptor that renders this receptor constitutively active. We assessed the sensitivity of primary mast cells (MC) and mast cell lines HMC1.2 (D816V mutated), ROSA (KIT WT) and ROSA (KIT D816V) cells to histone deacetylase inhibitor (HDACi) treatment. We found that of four HDACi, suberoyl anilide hydroxamic acid (SAHA) was the most effective in killing mutated MC. SAHA downregulated KIT, followed by major MC apoptosis. Primary SM patient MC cultured ex vivo were even more sensitive to SAHA than HMC1.2 cells, whereas primary MC from healthy subjects were less affected. There was a correlation between cell death and SM disease severity, where cell death was more pronounced in the case of aggressive SM, with almost 100% cell death among MC from the mast cell leukemia patient. Additionally, ROSA (KIT D816V) was more affected by HDACi than ROSA (KIT WT) cells. Using ChIP qPCR, we found that the level of active chromatin mark H3K18ac/H3 decreased significantly in the KIT region. This epigenetic silencing was seen only in the KIT region and not in control genes upstream and downstream of KIT, indicating that the downregulation of KIT is exerted by specific epigenetic silencing. In conclusion, KIT D816V mutation sensitized MC to HDACi mediated killing, and SAHA may be of value as specific treatment for SM, although the specific mechanism of action requires further investigation.
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| 13. |
- Moreno Berggren, Daniel, et al.
(författare)
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Prognostic scoring systems and comorbidities in chronic myelomonocytic leukaemia : a nationwide population-based study
- 2021
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Ingår i: British Journal of Haematology. - : John Wiley & Sons. - 0007-1048 .- 1365-2141. ; 192:3, s. 474-483
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Tidskriftsartikel (refereegranskat)abstract
- Outcomes in chronic myelomonocytic leukaemia (CMML) are highly variable and may be affected by comorbidity. Therefore, prognostic models and comorbidity indices are important tools to estimate survival and to guide clinicians in individualising treatment. In this nationwide population-based study, we assess comorbidities and for the first time validate comorbidity indices in CMML. We also compare the prognostic power of: the revised International Prognostic Scoring System (IPSS-R), CMML-specific prognostic scoring system (CPSS), MD Anderson Prognostic Scoring System (MDAPS) and Mayo score. In this cohort of 337 patients with CMML, diagnosed between 2009 and 2015, the median overall survival was 21 center dot 3 months. Autoimmune conditions were present in 25% of the patients, with polymyalgia rheumatica and Hashimoto's thyroiditis being most common. Of the tested comorbidity indices: the Charlson Comorbidity Index (CCI), Haematopoietic cell transplantation-specific Comorbidity Index (HCT-CI) and Myelodysplastic Syndrome-Specific Comorbidity Index (MDS-CI), CCI had the highest C-index (0 center dot 62) and was the only comorbidity index independently associated with survival in multivariable analyses. When comparing the prognostic power of the scoring systems, the CPSS had the highest C-index (0 center dot 69). In conclusion, using 'real-world' data we found that the CCI and CPSS have the best prognostic power and that autoimmune conditions are overrepresented in CMML.
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| 14. |
- Nair, Deepika, et al.
(författare)
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Methylseleninic Acid Sensitizes Ovarian Cancer Cells to T-Cell Mediated Killing by Decreasing PDL1 and VEGF Levels
- 2018
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Ingår i: Frontiers in Oncology. - : Frontiers Media S.A.. - 2234-943X. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Redox active selenium (Se) compounds at sub toxic doses act as pro-oxidants with cytotoxic effects on tumor cells and are promising future chemotherapeutic agents. However, little is known about how Se compounds affect immune cells in the tumor microenvironment. We demonstrate that the inorganic Se compound selenite and the organic methylseleninic acid (MSA) do not, despite their pro-oxidant function, influence the viability of immune cells, at doses that gives cytotoxic effects in ovarian cancer cell lines. Treatment of the ovarian cancer cell line A2780 with selenite and MSA increases NK cell mediated lysis, and enhances the cytolytic activity of T cells. Increased T cell function was observed after incubation of T cells in preconditioned media from tumor cells treated with MSA, an effect that was coupled to decreased levels of PDL1, HIF-1 alpha, and VEGF. In conclusion, redox active selenium compounds do not kill or inactivate immune cells at doses required for anti-cancer treatment, and we demonstrate that MSA enhances T cell-mediated tumor cell killing via PDL1 and VEGF inhibition.
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| 15. |
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| 16. |
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| 17. |
- Salomonsson, Maya, et al.
(författare)
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Localization-Specific Expression of CCR1 and CCR5 by Mast Cell Progenitors
- 2020
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Ingår i: Frontiers in Immunology. - : FRONTIERS MEDIA SA. - 1664-3224. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Mast cells are powerful immune cells found predominately in barrier tissues. They play an important role in immune surveillance and act as effector cells in allergic reactions. Mast cells develop from mast cell progenitors (MCp), which migrate to the peripheral tissues via the blood circulation. Presumably, the homing of MCp to the peripheral sites and localization is regulated by chemotactic signals. Due to the scarce abundance of these cells, chemotactic receptors have not been previously characterized on primary MCp. Here, mRNA transcripts for CCR1 and CX(3)CR1 were identified in mouse bone marrow and lung MCp in a gene expression screen of chemotactic receptors. However, surface expression of CCR1 was only found in the bone marrow MCp. Flow cytometry-based screening identified distinct surface expression of CCR5 by mouse peritoneal mast cells and MCp, while surface expression of CXCR2-5, CX(3)CR1, CCR1-3, CCR6-7, and CCR9 was not detected. Low surface expression of CCR5 was detected in mouse MCp in the bone marrow, spleen, and lung. To translate the findings to human, blood and bone marrow MCp from healthy donors were analyzed for possible CCR1 and CCR5 expression. Human MCp showed distinct surface expression of both CCR1 and CCR5. The expression levels of these chemokine receptors were higher in human bone marrow MCp than in the peripheral blood, suggesting that CCR1 and CCR5 may mediate retention in the bone marrow. In conclusion, mouse and human MCp show differential expression of CCR1 and CCR5 depending on their localization.
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| 18. |
- Söderlund, Stina, et al.
(författare)
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Proteomic and transcriptomic screening demonstrates increased mast cell-derived CCL23 in systemic mastocytosis
- 2023
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Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier BV. - 0091-6749 .- 1097-6825. ; 152:1, s. 205-213
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Tidskriftsartikel (refereegranskat)abstract
- Background: Systemic mastocytosis (SM) is a heterogeneous group of mast cell-driven diseases diagnosed by bone marrow sampling. However, there are a limited number of available blood disease biomarkers.Objective: Our aim was to identify mast cell-derived proteins that could potentially serve as blood biomarkers for indolent and advanced forms of SM. Methods: We performed a plasma proteomics screening coupled with single-cell transcriptomic analysis in SM patients and healthy subjects.Results: Plasma proteomics screening identified 19 proteins upregulated in indolent disease compared to healthy, and 16 proteins in advanced disease compared to indolent. Among these, 5 proteins, CCL19, CCL23, CXCL13, IL-10, and IL12Rb1, were higher in indolent relative to healthy and in advanced disease compared to indolent. Single-cell RNA sequencing demonstrated that CCL23, IL-10, and IL-6 were selectively produced by mast cells. Notably, plasma CCL23 levels correlated positively with known markers of SM disease severity, namely tryptase levels, percentage bone marrow mast cell infiltration, and IL-6.Conclusion: CCL23 is produced predominantly by mast cells in SM, and CCL23 plasma levels are associated with disease severity, correlating positively with established markers of disease burden, thus suggesting that CCL23 is a specific SM biomarker. In addition, the combination of CCL19, CCL23, CXCL13, IL-10, and IL-12Rb1 may be useful for defining disease stage. (J Allergy Clin Immunol 2023;152:205-13.)
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| 19. |
- Tobiasson, Magnus, et al.
(författare)
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Comprehensive mapping of the effects of azacitidine on DNA methylation, repressive/permissive histone marks and gene expression in primary cells from patients with MDS and MDS-related disease
- 2017
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Ingår i: Oncotarget. - : IMPACT JOURNALS LLC. - 1949-2553. ; 8:17, s. 28812-28825
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Tidskriftsartikel (refereegranskat)abstract
- Azacitidine (Aza) is first-line treatment for patients with high-risk myelodysplastic syndromes (MDS), although its precise mechanism of action is unknown. We performed the first study to globally evaluate the epigenetic effects of Aza on MDS bone marrow progenitor cells assessing gene expression (RNA seq), DNA methylation (Illumina 450k) and the histone modifications H3K18ac and H3K9me3 (ChIP seq). Aza induced a general increase in gene expression with 924 significantly upregulated genes but this increase showed no correlation with changes in DNA methylation or H3K18ac, and only a weak association with changes in H3K9me3. Interestingly, we observed activation of transcripts containing 15 endogenous retroviruses (ERVs) confirming previous cell line studies. DNA methylation decreased moderately in 99% of all genes, with a median beta-value reduction of 0.018; the most pronounced effects seen in heterochromatin. Aza-induced hypomethylation correlated significantly with change in H3K9me3. The pattern of H3K18ac and H3K9me3 displayed large differences between patients and healthy controls without any consistent pattern induced by Aza. We conclude that the marked induction of gene expression only partly could be explained by epigenetic changes, and propose that activation of ERVs may contribute to the clinical effects of Aza in MDS.
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| 20. |
- Ungerstedt, Johanna S
(författare)
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Coagulation and inflammation in experimental endotoxemia in vitro and in vivo : monitoring method and effects of nicotinamide
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In gram negative sepsis, endotoxin from the bacterial membrane elicits proinflammatory and procoagulant host responses. Sepsis and its frequent complication disseminated intravascular coagulation (DIC) are leading causes of morbidity and mortality in the intensive care. A pivotal mechanism in the pathogenesis of DIC is the expression of tissue factor (TF) on circulating monocytes after endotoxin encounter. Activation of the cascade systems of coagulation and inflammation can lead to a rapid deterioration in e.g. sepsis with procoagulant changes and microthromboses, resulting in DIC and multi organ failure. Monitoring of the degree of coagulation activation, to discover changes before clinical exacerbation, is critical. We have established a global monitoring method for coagulation activity, clotting onset time (COT), based on free oscillating rheometry. The assay design mimicks the natural blood milieu, as the method is based on CaC12 repletion of blood or plasma, adding no artificial activators or inhibitors. The COT method proved to be a quick and reliable test, able to detect hypoand hypercoagulation. It also showed promising results as a bedside monitoring method, able to detect the transient activation of coagulation caused by intravenous injection of endotoxin to healthy volunteers. We also demonstrate that the COT method is sensitive even to small changes in the amount of endotoxin induced monocyte surface TF. In neurotrauma patients, COT was a predictor of prognosis for the patients. This observation, however, is difficult to interpret and requires further investigation. The vitamin B derivative nicotinamide was assessed for its potential modulating effects on endotoxin induced activation of coagulation and inflammation. Nicotinamide is a known PARP inhibitor. PARP is necessary for activation of the transcription factor NFkappabeta, responsible for transcription of many genes involved in the response to endotoxin, e.g. proinflammatory cytokines, giving a rationale for a potential beneficial effect of nicotinamide in endotoxemia. We demonstrate that nicotinamide is a potent inhibitor of three major endotoxin induced proinflammatory cytokines, Il-1 beta, IL-6 and IL-8, in addition to the previously known TNFalpha inhibiting effect. However, the dose dependent inhibition of endotoxin induced proinflammatory responses was shown unlikely to be due to PARP inhibition. In endotoxin stimulated leukocyte suspensions as well as in whole blood, nicotinamide caused a dose dependent decrease of monocyte TF expression, describing a previously unknown inhibitory effect of nicotinamide on the procoagulant changes associated with endotoxemia. We have also demonstrated that the decrease of monocyte TF expression is at least partly caused by shedding from the monocyte surface. Our conclusion is that nicotinamide may have a therapeutic potential in modulating conditions associated with activation of coagulation and inflammation, such as in sepsis and DIC.
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| 21. |
- Wedge, Eileen, et al.
(författare)
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Allogeneic Hematopoietic Stem Cell Transplantation for Chronic Myelomonocytic Leukemia : Clinical and Molecular Genetic Prognostic Factors in a Nordic Population
- 2021
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Ingår i: Transplantation and Cellular Therapy. - : Elsevier. - 2666-6375 .- 2666-6367. ; 27:12, s. 991.e1-991.e9
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Tidskriftsartikel (refereegranskat)abstract
- Chronic myelomonocytic leukemia (CMML) is an aggressive disease in which survival after allogeneic hematopoietic stem cell transplantation (HCT) remains relatively poor. An assessment of prognostic factors is an important part of treatment decision making and has the potential to be greatly improved by the inclusion of molecular genetics. However, there is a significant knowledge gap in the interpretation of mutational patterns. This study aimed to describe outcomes of allogeneic HCT in patients with CMML in relation to clinical and molecular genetic risk factors. This retrospective study included 64 patients with CMML who underwent allogeneic HCT between 2008 and 2018, with a median follow-up of 5.4 years. Next-generation sequencing using targeted myeloid panels was carried out on saved material from 51 patients from the time of transplantation. Kaplan-Meier and Cox regression were used for analysis of overall survival (OS), and cumulative incidence with competing risks and Fine and Gray models were used for analysis of relapse and nonrelapse mortality (NRM). Mutations were detected in 48 patients (94%), indicating high levels of minimal residual disease (MRD) positivity at transplantation, even among those in complete remission (CR) (n = 14), 86% of whom had detectable mutations. The most frequently mutated genes were ASXL1 (37%), TET2 (37%), RUNX1 (33%), SRSF2 (26%), and NRAS (20%). Risk stratification using the CMML-specific Prognostic Scoring System molecular score (CPSS-Mol) resulted in 45% of patients moving to a higher risk-group compared with risk stratification using the CPSS. High leucocyte count (>= 13 x 10(9)/L), transfusion requirement, and previous intensive chemotherapy were associated with higher incidence of relapse. Being in CR was not linked to better outcomes. Neither ASXL1 nor RUNX1 mutation was associated with a difference in OS, relapse, or NRM, despite being high risk in the nontransplantation setting. TET2 mutations were associated with a significantly higher 3-year OS (73% versus 40%; P =.039). Achieving MRD-negative CR was rare in this CMML cohort, which may explain why we did not observe better outcomes for those in CR. This merits further investigation. Our analyses suggest that the negative impact of ASXL1 and RUNX1 mutations can be overcome by allogeneic HCT; however, risk stratification is complex in CMML and requires larger cohorts and multivariate models, presenting an ongoing challenge in this rare disease.
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| 22. |
- Wu, Chenyan, et al.
(författare)
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Single-cell transcriptomics reveals the identity and regulators of human mast cell progenitors
- 2022
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Ingår i: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 6:15, s. 4439-4449
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Tidskriftsartikel (refereegranskat)abstract
- Mast cell accumulation is a hallmark of a number of diseases, including allergic asthma and systemic mastocytosis. Immunoglobulin E-mediated crosslinking of the Fc epsilon RI receptors causes mast cell activation and contributes to disease pathogenesis. The mast cell lineage is one of the least studied among the hematopoietic cell lineages, and controversies remain about whether Fc epsilon RI expression appears during the mast cell progenitor stage or during terminal mast cell maturation. Here, we used single-cell transcriptomics analysis to reveal a temporal association between the appearance of Fc epsilon RI and the mast cell gene signature in CD341 hematopoietic progenitors in adult peripheral blood. In agreement with these data, the Fc epsilon RI+ hematopoietic progenitors formed morphologically, phenotypically, and functionally mature mast cells in long-term culture assays. Single-cell transcriptomics analysis further revealed the expression patterns of prospective cytokine receptors regulating development of mast cell progenitors. Culture assays showed that interleukin-3 (IL-3) and IL-5 promoted disparate effects on progenitor cell proliferation and survival, respectively, whereas IL-33 caused robust Fc epsilon RI downregulation. Taken together, we showed that FceRI expression appears at the progenitor stage of mast cell differentiation in peripheral blood. We also showed that external stimuli regulate Fc epsilon RI expression of mast cell progenitors, providing a possible explanation for the variable Fc epsilon RI expression levels during mast cell development.
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