| 1. |
- Li, Hongzhe, et al.
(författare)
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Identification of phenotypically, functionally, and anatomically distinct stromal niche populations in human bone marrow based on single-cell RNA sequencing
- 2023
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Ingår i: eLife. - : eLife Sciences Publications, Ltd. - 2050-084X. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Hematopoiesis is regulated by the bone marrow (BM) stroma. However, cellular identities and functions of the different BM stromal elements in humans remain poorly defined. Based on single-cell RNA sequencing (scRNAseq), we systematically characterized the human non-hematopoietic BM stromal compartment and we investigated stromal cell regulation principles based on the RNA velocity analysis using scVelo and studied the interactions between the human BM stromal cells and hematopoietic cells based on ligand-receptor (LR) expression using CellPhoneDB. scRNAseq led to the identification of six transcriptionally and functionally distinct stromal cell populations. Stromal cell differentiation hierarchy was recapitulated based on RNA velocity analysis and in vitro proliferation capacities and differentiation potentials. Potential key factors that might govern the transition from stem and progenitor cells to fate-committed cells were identified. In situ localization analysis demonstrated that different stromal cells were localized in different niches in the bone marrow. In silico cell-cell communication analysis further predicted that different stromal cell types might regulate hematopoiesis through distinct mechanisms. These findings provide the basis for a comprehensive understanding of the cellular complexity of the human BM microenvironment and the intricate stroma-hematopoiesis crosstalk mechanisms, thus refining our current view on human hematopoietic niche organization.
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| 2. |
- Rosa, Fábio F, et al.
(författare)
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Single-cell transcriptional profiling informs efficient reprogramming of human somatic cells to cross-presenting dendritic cells
- 2022
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Ingår i: Science Immunology. - : American Association for the Advancement of Science (AAAS). - 2470-9468. ; 7:69, s. 1-18
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Tidskriftsartikel (refereegranskat)abstract
- Type 1 conventional dendritic cells (cDC1s) are rare immune cells critical for the induction of antigen-specific cytotoxic CD8+ T cells, although the genetic program driving human cDC1 specification remains largely unexplored. We previously identified PU.1, IRF8, and BATF3 transcription factors as sufficient to induce cDC1 fate in mouse fibroblasts, but reprogramming of human somatic cells was limited by low efficiency. Here, we investigated single-cell transcriptional dynamics during human cDC1 reprogramming. Human induced cDC1s (hiDC1s) generated from embryonic fibroblasts gradually acquired a global cDC1 transcriptional profile and expressed antigen presentation signatures, whereas other DC subsets were not induced at the single-cell level during the reprogramming process. We extracted gene modules associated with successful reprogramming and identified inflammatory signaling and the cDC1-inducing transcription factor network as key drivers of the process. Combining IFN-γ, IFN-β, and TNF-α with constitutive expression of cDC1-inducing transcription factors led to improvement of reprogramming efficiency by 190-fold. hiDC1s engulfed dead cells, secreted inflammatory cytokines, and performed antigen cross-presentation, key cDC1 functions. This approach allowed efficient hiDC1 generation from adult fibroblasts and mesenchymal stromal cells. Mechanistically, PU.1 showed dominant and independent chromatin targeting at early phases of reprogramming, recruiting IRF8 and BATF3 to shared binding sites. The cooperative binding at open enhancers and promoters led to silencing of fibroblast genes and activation of a cDC1 program. These findings provide mechanistic insights into human cDC1 specification and reprogramming and represent a platform for generating patient-tailored cDC1s, a long-sought DC subset for vaccination strategies in cancer immunotherapy.
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| 3. |
- Ahlstrand, Erik, 1974-, et al.
(författare)
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Highly Reduced Survival in Essential Thrombocythemia and Polycythemia Vera Patients with Vascular Complications during Follow-up
- 2020
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Ingår i: European Journal of Haematology. - : Munksgaard Forlag. - 0902-4441 .- 1600-0609. ; 104:3, s. 271-278
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To explore the relative importance of risk factors, treatments and blood counts for the occurrence of vascular complications and their impact on life expectancy in Essential Thrombocythemia (ET) and Polycythemia Vera (PV).METHODS: Nested case-control study within the Swedish MPN registry. From a cohort of 922 ET patients and 763 PV patients, 71 ET and 81 PV cases with vascular complications were compared to matched controls.RESULTS: Incidence of vascular complications were 2.0 and 3.4 events per 100 patient-years in ET and PV, respectively. At diagnosis, no significant risk factor differences were observed between cases and controls in neither of the diseases. At the time of vascular event, ET complication cases did not differ significantly from controls but in PV, cases had significantly higher WBCs and were to a lesser extent treated with antithrombotic and cytoreductive therapy. Life expectancy was significantly decreased in both ET and PV cases compared to controls.CONCLUSIONS: The risk of vascular complications is high in both ET and PV and these complications have a considerable impact on life expectancy. The protective effect of antithrombotic and cytoreductive therapy for vascular complications in PV underscores the importance of avoiding undertreatment.
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| 4. |
- Bräunig, Sandro, et al.
(författare)
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Three-dimensional spatial mapping of the human hematopoietic microenvironment in healthy and diseased bone marrow
- 2023
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Ingår i: Cytometry Part A. - 1552-4922. ; 103:10, s. 763-776
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Tidskriftsartikel (refereegranskat)abstract
- The bone marrow hematopoietic microenvironment (HME) plays a pivotal role in regulating normal and diseased hematopoiesis. However, the spatial organization of the human HME has not been thoroughly investigated yet. Therefore, we developed a three-dimensional (3D) immunofluorescence model to analyze changes in the cellular architecture in control and diseased bone marrows (BMs). BM biopsies from patients with myeloproliferative neoplasms (MPNs) were stained sequentially for CD31, CD34, CD45, and CD271 with repetitive bleaching steps to realize five color images with DAPI as a nuclear stain. Hematopoietically normal age-matched BM biopsies served as controls. Twelve subsequent slides per sample were stacked to create three-dimensional bone marrow reconstructions with the imaging program Arivis Visions 4D. Iso-surfaces for niche cells and structures were created and exported as mesh objects for spatial distribution analysis in the 3D creation suite Blender. We recapitulated the bone marrow architecture using this approach and produced comprehensive 3D models of endosteal and perivascular BM niches. MPN bone marrows displayed apparent differences compared to the controls, especially concerning CD271 staining density, megakaryocyte (MK) morphology, and distribution. Furthermore, measurements of the spatial relationships of MKs and hematopoietic stem and progenitor cells with vessels and bone structures in their corresponding niche environments revealed the most pronounced differences in the vascular nice in polycythemia vera. Taken together, using a repetitive staining and bleaching approach allowed us to establish a 5-color analysis of human BM biopsies, which is difficult to achieve with conventional staining approaches. Based on this, we generated 3D BM models which recapitulated key pathological features and, importantly, allowed us to define the spatial relationships between different bone marrow cell types. We, therefore, believe that our method can provide new and valuable insights into bone marrow cellular interaction research.
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| 5. |
- Garofalo, Fabio, et al.
(författare)
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Statistic estimation of cell compressibility based on acoustophoretic separation data
- 2020
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Ingår i: Microfluidics and Nanofluidics. - : Springer Science and Business Media LLC. - 1613-4982 .- 1613-4990. ; 24:8
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Tidskriftsartikel (refereegranskat)abstract
- We present a new experimental method that measures the compressibility of phenotype-specific cell populations. This is done by performing statistical analysis of the cell counts from the outlets of an acoustophoresis chip as a function of the increasing actuator voltage (i.e. acoustic energy density) during acoustophoretic separation. The theoretical separation performance curve, henceforth, Side-Stream Recovery (SSR), vs the piezo-actuator voltage (V) is derived by moment analysis of a one-dimensional model of acoustophoresis separation, accounting for distributions of the cell or microparticle properties and the system parameters (hydrodynamics, radiation force, drag enhancement, and acoustic streaming). The acoustophoretic device is calibrated with polymer microbeads of known properties by fitting the experimental SSR with the theoretical SSR , in which the acoustic energy density is considered proportional to the squared voltage, i.e. Eac=αV2. The fitting parameter α for the calibration procedure is the device effectivity, reflecting the efficiency in performing acoustophoretic microparticle displacement. Once calibrated, the compressibility of unknown cells is estimated by fitting experimental SSR cell data points with the theoretical SSR curve. In this procedure, the microparticle compressibility is the fitting parameter. The method is applied to estimate the compressibility of a variety of cell populations showing its utility in terms of rapid analysis and need for minute sample amounts.
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| 6. |
- Kadefors, Måns, et al.
(författare)
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CD105+CD90+CD13+ identifies a clonogenic subset of adventitial lung fibroblasts
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Mesenchymal cells are important components of specified niches in the lung, and can mediate a wide range of processes including tissue regeneration and repair. Dysregulation of these processes can lead to improper remodeling of tissue as observed in several lung diseases. The mesenchymal cells responsible remain poorly described, partially due to the heterogenic nature of the mesenchymal compartment and the absence of appropriate markers. Here, we describe that CD105+CD90+ mesenchymal cells can be divided into two populations based on their expression of CD13/aminopeptidase N (CD105+CD90+CD13− and CD105+CD90+CD13+). By prospective isolation using FACS, we show that both these populations give rise to clonogenic fibroblast-like cells, but with an increased clonogenic and proliferative capacity of CD105+CD90+CD13+ cells. Transcriptomic and spatial analysis pinpoints an adventitial fibroblast subset as the origin of CD105+CD90+CD13+ clonogenic mesenchymal cells in human lung.
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| 7. |
- Li, Hongzhe, et al.
(författare)
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Early growth response 1 regulates hematopoietic support and proliferation in human primary bone marrow stromal cells
- 2020
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Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 1592-8721 .- 0390-6078. ; 105:5, s. 1206-1215
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Tidskriftsartikel (refereegranskat)abstract
- Human bone marrow stromal cells are key elements of the hematopoietic environment and they play a central role in bone and bone marrow physiology. However, how key stromal cell functions are regulated is largely unknown. We analyzed the role of the immediate early response transcription factor EGR1 as key stromal cell regulator and found that EGR1 was highly expressed in prospectively-isolated primary bone marrow stromal cells, downregulated upon culture, and low in non-colony-forming CD45neg stromal cells. Furthermore, EGR1 expression was lower in proliferative regenerating adult and fetal primary cells compared to adult steady-state bone marrow stromal cells. Overexpression of EGR1 in stromal cells induced potent hematopoietic stroma support as indicated by an increased production of transplantable CD34+CD90+ hematopoietic stem cells in expansion co-cultures. The improvement of bone marrow stroma support function was mediated by increased expression of hematopoietic supporting genes, such as VCAM1 and CCL28. Furthermore, EGR1 overexpression markedly decreased stromal cell proliferation whereas EGR1 knockdown caused the opposite effects. These findings thus show that EGR1 is a key stromal transcription factor with a dual role in regulating proliferation and hematopoietic stroma support function that is controlling a genetic program to coordinate the specific functions of bone marrow stromal cells in their different biological contexts.
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| 8. |
- Lim, Hooi Ching, et al.
(författare)
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Development of acoustically isolated extracellular plasma vesicles for biomarker discovery in allogeneic hematopoietic stem cell transplantation
- 2021
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Ingår i: Biomarker research. - : Springer Science and Business Media LLC. - 2050-7771. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Infection and graft-versus-host disease (GvHD) are the major causes for mortality and morbidity of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Plasma-derived extracellular vesicles (EVs) contain disease-related proteins, DNAs and RNAs, and have recently been suggested as potential biomarker candidates for transplantation complications. However, EV isolation from small plasma volumes in clinical biomarker studies using conventional methods is challenging. We therefore investigated if EVs isolated by novel automated acoustic trapping could be developed as potential biomarkers for allo-HSCT complications by performing a clinical proof-of-principle study. Results: Plasma samples were collected from twenty consecutive patients with high-risk/relapsed hematologic malignancies undergoing allo-HSCT before transplantation and post-transplant up to 12 weeks. EVs were isolated from small plasma sample volumes (150 μl) by an automated, acoustofluidic-based particle trapping device, which utilizes a local λ/2 ultrasonic standing wave in a borosilicate glass capillary to capture plasma EVs among pre-seeded polystyrene microbeads through sound scatter interactions. We found that EVs could be reliably isolated from all plasma samples (n = 173) and that EV numbers increased more than 2-fold in the majority of patients after transplantation. Also, sufficient quantities of RNA for downstream microRNA (miRNA) analysis were obtained from all samples and EV miRNA profiles were found to differ from whole plasma profiles. As a proof of principle, expression of platelet-specific miR-142-3p in EVs was shown to correlate with platelet count kinetics after transplantation as expected. Importantly, we identified plasma EV miRNAs that were consistently positively correlated with infection and GvHD, respectively, as well as miRNAs that were consistently negatively correlated with these complications. Conclusions: This study demonstrates that acoustic enrichment of EVs in a clinical biomarker study setting is feasible and that downstream analysis of acoustically-enriched EVs presents a promising tool for biomarker development in allo-HSCT. Certainly, these findings warrant further exploration in larger studies, which will have significant implications not only for biomarker studies in transplantation but also for the broad field of EV-based biomarker discovery.
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| 9. |
- Lindgren, Marie, 1971, et al.
(författare)
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Survival and risk of vascular complications in myelofibrosis—A population-based study from the Swedish MPN group
- 2022
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Ingår i: European Journal of Haematology. - : Wiley. - 0902-4441 .- 1600-0609. ; 109:4, s. 336-342
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To gain knowledge of underlying risk factors for vascular complications and their impact on life expectancy in myelofibrosis. Methods: From a cohort of 392 myelofibrosis patients registered in the Swedish MPN registry 58 patients with vascular complications during follow-up were identified. Patients with vascular complications were compared with both 1:1 matched controls and the entire myelofibrosis cohort to explore potential risk factors for vascular complications and their impact on survival. Results: Incidence of vascular complications was 2.8 events per 100 patient-years and the majority of complications were thrombotic. Patients with complications were significantly older and had lower hemoglobin when compared to the entire cohort. In the case–control analysis, no significant risk factor differences were observed. The major cause of death was vascular complications and median survival was significantly impaired in patients with vascular complications (48 months) compared to controls (92 months). Inferior survival in patients with vascular complications was found to be dependent on IPSS risk category in a Cox regression model. Conclusion: Vascular complications have a considerable impact on survival in MF. At diagnosis, risk assessment by IPSS does not only predict survival but is also associated with the risk of vascular complications.
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| 10. |
- Olm, Franziska, et al.
(författare)
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Acoustophoresis enables the label-free separation of functionally different subsets of cultured bone marrow stromal cells
- 2021
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Ingår i: Cytometry. Part A : the journal of the International Society for Analytical Cytology. - : Wiley. - 1552-4930. ; 99:5, s. 476-487
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Tidskriftsartikel (refereegranskat)abstract
- Culture-expanded mesenchymal stromal cells (MSCs) are promising candidates for clinical cell-based therapies. MSC products are heterogeneous and we therefore investigated whether acoustophoresis, an ultrasound-based separation technology, could be used for the label-free enrichment of functionally different MSC populations. Acoustophoresis uses an ultrasonic standing wave in a microchannel which differentially affects the movement of cells depending on their acoustophysical properties, such as size, density, and compressibility. Human bone marrow MSCs were generated by standard adherent culture in xenofree medium and separated by microchip acoustophoresis. MSCs with up to 20% higher proliferation and 1.7-fold increased clonogenic potential were enriched in the side outlet of the chip compared to the input sample. These cells were significantly smaller (average diameter 14.5 ± 0.4 μm) compared to the center outlet fraction (average diameter 17.1 ± 0.6 μm) and expressed higher levels of genes related to proliferation and stem cell properties (i.e. Ki-67 (1.9-fold), Nanog1 (6.65-fold), Oct4 (2.9-fold), and CXCL12 (1.8-fold), n = 3) in the side outlet compared to input. Fractions of MSCs in G0 /G1 cell cycle phase were significantly enriched in the side fraction and an up to 2.8-fold increase of cells in S/G2 /M phases were observed in center fractions compared to side fractions and 1.3-fold increased compared to the input sample. Acoustophoresis did not compromise MSC phenotype, proliferation, clonogenic capacity, and viability (generally 87-98%), nor did it affect differentiation or immunomodulatory capacities. These results demonstrate that label-free acoustic separation can enrich functionally different MSC subsets which can potentially be employed to produce better-defined stromal cell products from cultured MSCs. Hence, acoustophoresis is a potentially promising separation technology to provide improved cell products for research and possible future clinical use.
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