Transcriptomic signature and pro-osteoclastic secreted factors of abnormal bone marrow stromal cells in fibrous dysplasia (Mouse)
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ABSTRACT: Fibrous dysplasia (FD) is a mosaic skeletal disorder caused by somatic activating variants in GNAS, encoding for Gαs, which leads to excessive cAMP signaling in bone marrow stromal cells (BMSCs). Despite advancements in our understanding of FD pathophysiology, the effect of Gαs activation in the BMSC transcriptome remains unclear, as well as how this translates into their local influence in the lesional microenvironment. In this study, we analyzed changes induced by Gαs activation in BMSC transcriptome and performed a comprehensive analysis of their production of cytokines and other secreted factors. We performed RNAseq of cultured BMSCs from patients with FD and healthy volunteers, and from an inducible mouse model of FD, and combined their transcriptomic profiles to build a robust FD BMSC genetic signature. Pathways related to Gαs activation, cytokine signaling, and extracellular matrix deposition were identified. In addition, a comprehensive profile of their secreted cytokines and other factors was performed to identify modulation of several key factors we hypothesized to be involved in FD pathogenesis. We also screened circulating cytokines in a collection of plasma samples from patients with FD, finding positive correlations of several cytokines to their disease burden score, as well as to one another and bone turnover markers. Overall, these data support a pro-inflammatory, pro-osteoclastic behavior of BMSCs bearing hyperactive Gαs variants, and point to several cytokines and other secreted factors as possible therapeutic targets and/or circulating biomarkers for FD.
Project description:Fibrous dysplasia (FD) is a mosaic skeletal disorder caused by somatic activating variants in GNAS, encoding for Gαs, which leads to excessive cAMP signaling in bone marrow stromal cells (BMSCs). Despite advancements in our understanding of FD pathophysiology, the effect of Gαs activation in the BMSC transcriptome remains unclear, as well as how this translates into their local influence in the lesional microenvironment. In this study, we analyzed changes induced by Gαs activation in BMSC transcriptome and performed a comprehensive analysis of their production of cytokines and other secreted factors. We performed RNAseq of cultured BMSCs from patients with FD and healthy volunteers, and from an inducible mouse model of FD, and combined their transcriptomic profiles to build a robust FD BMSC genetic signature. Pathways related to Gαs activation, cytokine signaling, and extracellular matrix deposition were identified. In addition, a comprehensive profile of their secreted cytokines and other factors was performed to identify modulation of several key factors we hypothesized to be involved in FD pathogenesis. We also screened circulating cytokines in a collection of plasma samples from patients with FD, finding positive correlations of several cytokines to their disease burden score, as well as to one another and bone turnover markers. Overall, these data support a pro-inflammatory, pro-osteoclastic behavior of BMSCs bearing hyperactive Gαs variants, and point to several cytokines and other secreted factors as possible therapeutic targets and/or circulating biomarkers for FD.
Project description:Multiple myeloma (MM) is a hematological cancer with inevitable drug resistance. MM cells interacting with bone marrow stromal cells (BMSCs) undergo substantial changes in transcriptome and develop de novo drug resistance. As a critical component in transcriptional regulation, how chromatin landscape is transformed in MM cells and regulates the transcriptional response to BMSCs remains elusive. We profiled transcriptome and regulome for MM cells using a transwell coculture system with BMSCs. The transcriptome and regulome of MM cells from the upper transwell resembled MM cells coexisting with BMSCs from the lower chamber but were distinctive to monoculture. BMSC-induced genes were enriched in JAK2/STAT3 signaling pathway, unfolded protein stress, signatures of early plasma cells, and response to proteasome inhibitors. Genes with accessibility increased at multiple regulatory sites were preferentially induced by BMSCs and enriched in response to drug and unfavorable prognostic markers from several MM patient cohorts. We proposed JUNB and ATF4::CEBPβ as candidate transcription factors (TFs) that modulated the BMSC-induced transformation of regulome linked to the response to external stimuli. Together, we characterized BMSC-induced transcriptome and regulome signatures of MM cells and prioritized TFs for future study to depict epigenetic mechanisms of BMSC-induced drug resistance in MM.
Project description:Multiple myeloma (MM) is a hematological cancer with inevitable drug resistance. MM cells interacting with bone marrow stromal cells (BMSCs) undergo substantial changes in transcriptome and develop de novo drug resistance. As a critical component in transcriptional regulation, how chromatin landscape is transformed in MM cells and regulates the transcriptional response to BMSCs remains elusive. We profiled transcriptome and regulome for MM cells using a transwell coculture system with BMSCs. The transcriptome and regulome of MM cells from the upper transwell resembled MM cells coexisting with BMSCs from the lower chamber but were distinctive to monoculture. BMSC-induced genes were enriched in JAK2/STAT3 signaling pathway, unfolded protein stress, signatures of early plasma cells, and response to proteasome inhibitors. Genes with accessibility increased at multiple regulatory sites were preferentially induced by BMSCs and enriched in response to drug and unfavorable prognostic markers from several MM patient cohorts. We proposed JUNB and ATF4::CEBPβ as candidate transcription factors (TFs) that modulated the BMSC-induced transformation of regulome linked to the response to external stimuli. Together, we characterized BMSC-induced transcriptome and regulome signatures of MM cells and prioritized TFs for future study to depict epigenetic mechanisms of BMSC-induced drug resistance in MM.
Project description:Human bone marrow stromal cells (BMSCs) are key elements of the hematopoietic environment and they play a central role in bone and bone marrow physiology. However, how key BMSC functions are regulated is largely unknown. We analyzed the role of the immediate early response transcription factor EGR1 as key BMSC regulator and found that EGR1 was highly expressed in prospectively-isolated primary BMSCs, downregulated upon culture, and lower in non-CFU-F-containing CD45neg BM cells. Furthermore, EGR1 expression was lower in proliferative regenerating adult and fetal primary cells compared to adult steady-state BMSCs. Accordingly, EGR1 overexpression markedly decreased BMSC proliferation but considerably improved hematopoietic stroma support function as indicated by an increased production of transplantable CD34+CD90+ hematopoietic stem cells in expansion co-cultures. The improvement of BMSC stroma support function was mediated by increased expression of hematopoietic supporting genes, such as VCAM1 and CCL28. On the other hand, EGR1 knockdown increased ROS-mediated BMSC proliferation, and clearly reduced BMSC hematopoietic stroma support potential. These findings thus show that EGR1 is a key BMSC 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 BMSC in their different biological contexts.
Project description:Bone marrow stromal cells (BMSCs) provide hematopoietic support, immunoregulation and contain a stem cell fraction capable of skeletogenic differentiation. A heterogeneous population of primary bone marrow BMSCs were isolated from a single human donor (FH181), and a lentiviral expression system was used to overexpress human telomerase reverse transcriptase (hTERT) and generate single cell-derived immortalised BMSC lines for multi-level analysis of functional markers for BMSC subsets. All clones expressed typical BMSC cell surface antigens, however clones Y101 and Y201 displayed typical BMSC tri-lineage differentiation capacity where clones Y102 and Y202 lacked significant tri-lineage differentiation potential. High quality RNA samples were isolated from all lines, and global gene expression analysis was performed in triplicate arrays (using Agilent SurePrint G3 Human Gene Expression 8x60K v2 Microarrays) in order to identify distinguishing characteristics of these lines, compared to the parental primary BMSCs from which they were derived.
Project description:Hypertension and persistent activation of the renin-angiotensin system (RAS) are predisposing factors for development of acute kidney injury (AKI). Although bone marrow-derived stromal cells (BMSCs) have shown therapeutic promise in treatment of AKI, the impact of pathological RAS on BMSC functionality has remained unresolved. RAS and its local components in the bone marrow are involved in several key steps of cell maturation processes. This may also render BMSC population vulnerable to alterations even in the early phases of RAS pathology. We isolated TG-BMSCs from young, end organ disease-free rats with increased RAS activation (human angiotensinogen/renin double transgenic rats; dTGR) that eventually develop hypertension and die of end-organ damage and kidney failure at 8-weeks-of-age. Control cells were isolated from wild-type Sprague-Dawley rats (SD-BMSCs). Cell phenotype, mitochondrial reactive oxygen species (ROS) production and respiration were assessed, and gene expression profiling was carried out using microarrays. Cells’ therapeutic efficacy was evaluated in a rat model of acute ischemia-reperfusion-induced AKI. Serum urea and creatinine were measured at 24h and 48h. Acute tubular damage was scored and immunohistochemistry was used for evaluation for markers of inflammation (MCP-1, ED-1), and kidney injury (KIM-1, NGAL). TG-BMSCs showed distinct mitochondrial morphology, decreased cell respiration, and increased production of ROS. Gene expression profiling revealed a pronounced pro-inflammatory phenotype. In contrast to the therapeutic effect of SD-BMSCs, administration of TG-BMSCs in the AKI model resulted in exacerbation of kidney injury and high mortality. Our results demonstrate that early persistent RAS activation can dramatically compromise therapeutic potential of BMSCs by shift into a pro-inflammatory phenotype with mitochondrial dysfunction. A comparison of transcriptome of a bone marrow-derived stromal cells from a double-transgene rats compared to those from control rats
Project description:Bone marrow derived stromal cells (BMSCs) are a multipotent population that supports angiogenesis, wound healing, immunomodulation and plays an active role in the hematopoietic niche. On the other hand, they are also involved in the nurturing of bone marrow tumors and metastasis, showing a pro-tumorigenic behavior. BMSCs secrete a wide range of cytokines, growth factors and matrix proteins that are likely responsible for many of these effects. However, it is not clear whether this pro-tumorigenic behavior of BMSCs is induced by the tumor cells, neither in what extent the tumor cells affect the type and quantity of factors produced by BMSCs. To determine how tumor cells that arise from bone marrow affect the BMSCs, we selected three myeloid leukemia cell lines (TF-1, TF-1alpha and K562) and co-cultured them with BMSCs from healthy donors. We found that, under co-culture condition, the gene expression profiling of BMSCs revealed up-regulation of many pro-inflammatory signaling related genes, mainly IL-17 signaling-related genes. Moreover, IL-17 signaling-related cytokines CCL2 and IL8, were increased in co-culture supernatants. We conclude that BMSCs react to the presence of leukemia cells undergoing changes in the cytokine and chemokine secretion profile. Thus, BMSCs and leukemia cells both contribute to the creation of a competitive niche more favorable to leukemia stem cells. BMSCs from healthy donors were transwell co-cultured with three different myeloid leukemia cell lines: TF-1 (n=3), TF-1alpha (n=3) and K562 (n=3). A 1-um Transwell system (BDBiosciences, San Jose, CA USA) was used to maintain the cultured BMSC and leukemia cell populations separate from each other. As a control BMSCs were also transwell co-cultured under the same conditions with CD34+ cells (n=9) isolated from G-CSF-mobilized peripheral blood stem cells from healthy donors. An alternative co-culture method was used to analyze BMSCs and leukemia cells in direct contact: TF-1 (n=3), TF-alpha (n=3) and K562 (n=3). The two populations were cultured together in the same well without any membrane separation. BMSCs (n=18), TF-1 (n=3), TF-1alpha (n=3), K562 (n=3) and CD34+ (n=9) cells cultured alone (mono-cultures) were used as controls. Cells from both mono- and co-culture conditions were harvested at 4h, 10h, and 24h.
Project description:Ex vivo expansion of Bone Marrow Stromal Cells (BMSC) is required to obtain clinical dose for cellular therapy, and different labs use different confluence in their practice, however, the impacts of 100% confluence on the biological properties of BMSC remain controversial. In this study, we detected the changes occurred to BMSCs when they reached 100% confluence, including viability, population doubling time (PDT), apoptosis, colony formation, immunosuppression, proteins in the culture supernatant, and surface markers; we also performed gene expression profiling and microRNA profiling on 50%, 80% and 100% confluent BMSCs. Our results showed that 100% confluent BMSCs had similar level of immunosuppression to 80% confluent BMSCs; they increased the expression of CD10, CD54, CD106, CD200, TLR4, but decreased CD49f and PODXL; we detected of 39 proteins in the culture supernatant, which displayed different patterns and an increase on the PEDF/VEGF ratio was observed with higher confluence. We identified 26 differentially expressed microRNAs, which were reported to be involved in the proliferation and differentiation of BMSC; and 2708 genes that were involved in extracellular matrix, cell adhesion, immune response and inflammatory response; particularly, angiogenesis inhibitor PEDF, and Wnt Singling inhibitors DKK1, DKK2, and DKK3 were up-regulated by 100% confluent BMSCs. These data suggest that 100% confluent BMSC may retain immunosuppressive activities but have comprised pro-angiogenesis effects. Gene expression profiling on BMSCs of 3 confluences (50%, 80% and 100%) from 5 healthy donors: 09FC37 (n=3), 09FC43 (n=3), 09FC44 (n=3), 09FC45 (n=3), 09FC49 (n=3) as biological repeats.
Project description:Bone marrow stromal cells (BMSCs) are multipotent stem cells that preferentially differentiate into mesenchymal cells. If they can be dedifferentiated into embryonic stem cell-like cells, they will be a highly attractive source for cell therapy. Cell and egg extracts have been used in a few studies to evaluate nuclear reprogramming, but these have not examined cell pluripotency in any detail. In this study, we used a cell reversible permeabilization method to treat BMSC with Xenopus laevis mitotic egg extract. We observed an upregulation of the pluripotent protein Oct3/4 in BMSCs treated by this extract. We also further evaluated transcriptional changes with a focused stem cell oligonucleotide array. A number of genes involved in the Notch or Wnt signaling pathways were upregulated in BMSC exposed to Xenopus egg extract. In conclusion, our microarray data from BMSCs exposure to egg extracts may provide interesting clues regarding factors involved in nuclear reprogramming. Our approach is an alternative method towards dedifferentiation of cells without genetic modification, which is preferable in the clinical situation. Keywords: Cell type comparison Expression profiling was performed on murine bonemarrow stromal cells cultured in-vitro versus stromal cells exposed to Xenopus extract and compared with murine embryonic stem cells
Project description:Bone marrow stromal cells (BMSCs) can be expanded by serial passage, but expansion is limited by cell senescence. The nature of changes associated with BMSC serial passages was assessed. Transcriptome analysis of 10 early and 15 late passage samples from 5 subjects revealed 2193 differentially expressed genes; those highly expressed in early passage cells were overrepresented in skeletal system development, embryonic morphogenesis, tube morphogenesis, etc, while those highly expressed in the late passage BMSCs were overrepresented in nucleosome assembly; chromatin assembly, DNA packaging, etc. 57 BMSC samples from 7 donors were further analyzed for the transition from an early to late passage; 155 genes were highly correlated with BMSC senescence and a set of 24 genes was predictive of BMSCs lifespan. The change from an early to a late passage molecular signature occurred between passage 3 and 5. In contrast, senescence associated beta-galactosidase staining began to increase after passage 6 or 7 and colony formation efficiency began to fall after passage 7. These data indicated that the onset of molecular changes associated with BMSC passage varied among individuals and preceded changes in commonly used indicators of BMSC senescence. The set of 24 BMSC lifespan predictive genes will be useful in assessing the quality of clinical BMSC products.