scholarly journals Nonbone Marrow CD34 + Cells Are Crucial for Endothelial Repair of Injured Artery

Author(s):  
Liujun Jiang ◽  
Ting Chen ◽  
Shasha Sun ◽  
Ruilin Wang ◽  
Jiacheng Deng ◽  
...  

Rationale: Endothelial cells (EC) play a critical role in multiple cardiovascular diseases. Circulating CD34+ cells are believed to be endothelial progenitors that have been used to treat cardiovascular diseases. However, the exact identity and the role of CD34+ cells in vascular regeneration remains unclear. Objective: We aimed to investigate the exact identity and the role of CD34+ cells in vascular regeneration. Methods and Results: Compared to healthy arteries, CD34 expression percentage was significantly increased in diseased femoral arteries from patients. Using a guide-wire induced endothelial denudation model, we reported the transcriptional profiling of over 30,000 cells by single-cell RNA sequencing analysis and provided a cell atlas of normal and lesioned arteries in mouse, in which a heterogeneous population of CD34+ cells were revealed. Combining the inducible lineage tracing Cd34-CreERT2;R26-tdTomato mouse model and bone marrow transplantation experiments, we showed that nonbone marrow CD34+ mesenchymal cells acquired endothelial cell fate in the injured femoral artery rather than pre-exiting ECs, while bone marrow-derived CD34+ cells differentiated into immune cells locally after vessel injury. Depletion of nonbone marrow CD34+ cells using diphtheria toxin induced cell ablation models, exacerbate neointimal lesions of the injured vessel. Furthermore, isolated vascular adventitia CD34+ cells displayed endothelial differentiation, in which microRNA-21-Smad7-pSmad2/3 pathway regulated endothelial gene expression and function during differentiation. Conclusions: Our study provides a transcriptional and cellular landscape of vessels after endothelial denudation. Our findings suggest heterogeneous CD34+ cells serve as a contributor not only to endothelial regeneration but also an inflammatory response that may provide therapeutic insights into vascular diseases.

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 923-923
Author(s):  
Katie Giger ◽  
Georgios E Christakopoulos ◽  
Lisa Trump ◽  
Clarissa E. Johnson ◽  
Haripriya Sakthivel ◽  
...  

Abstract CDAR (ClinicalTrials.gov Identifier: NCT02964494), a registry for patients with Congenital Dyserythropoietic Anemia (CDA) in North America, was recently created with the goal to provide a longitudinal database and associated biorepository to facilitate natural history studies and research on the molecular pathways involved in the pathogenesis of CDAs. A 2 y.o. female patient with transfusion dependent anemia, pathologic diagnosis of Congenital Dyserythropoietic Anemia type I (CDA-I), and neurodevelopmental delay was enrolled in CDAR. Next Generation sequencing and deletion/duplication assay identified no mutations in the known CDA-associated genes, including CDAN1 and C15orf41, which are causative for CDA-I. Whole-exome sequencing for the patient and her parents (family-trio design) revealed a novel, de novo VPS4A missense variant located in the last codon of exon 8, potentially affecting splicing. VPS4A is an ATPase which, in association with the endosomal sorting complex required for transport (ESCRT), has been shown to play a critical role in cell division of HeLa cells in vitro, concentrating at the spindle poles during mitosis and at the midbody during cytokinesis. The aim of this work is to validate the pathogenetic role of the VPS4A variant for CDA and further investigate the role of VPS4A in erythroblast mitosis and cytokinesis. Central review of the patient's bone marrow aspirate smears revealed bi-nucleated erythroblasts in the range of 3-7%, a criterion compatible with CDA-I. However, cytoplasmic bridges were noted (arrows in Figure 1A) rather than the nuclear bridges typical of CDA-I. Immunofluorescence staining performed on erythroblasts generated ex vivo from normal CD34+ cells verified that VPS4A localizes to the spindle poles during mitosis and the midbody during cytokinesis in dividing human erythroid cells analyzed by Imaging Flow Cytometry (Figure 1B). The level of VPS4A mRNA expression in the patient's reticulocytes was evaluated by qPCR using three different sets of primers and found to be decreased by 55-70% compared to control reticulocytes and knock-down of VPS4A in normal CD34+ cells resulted in erythroid cultures enriched in binucleated cells. Induced pluripotent stem cells (iPSCs) were generated from the patient's peripheral blood mononuclear cells after the family's consent. Erythroblasts produced from these iPSCs exhibited decreased VPS4A localization at the spindle poles and midbody and fail to divide properly, frequently maintaining cytoplasmic bridges as seen in the patient's bone marrow. Additionally, flow cytometry analysis of the patient's peripheral blood cells stained with anti-CD71 for the transferrin receptor and Thiazol Orange (TO) for RNA revealed a unique cell population which is TO negative, yet CD71 positive implying that VPS4A is also involved in reticulocyte maturation, likely participating in vesicle formation and the normal exocytosis of the transferrin receptor. VPS4A appears to play a critical role in erythroblast mitosis and cytokinesis, as well as erythrocyte maturation, and is a novel candidate gene for congenital dyserythropoietic anemia. Figure 1. A) Binucleated erythroblasts and cytoplasmic bridges (arrows) were noted on the patient's bone marrow aspirate smears. B) VPS4A localizes at the spindle poles (upper image) and midbody (lower image) in normal human erythroblasts. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.


2020 ◽  
Vol 11 ◽  
Author(s):  
Courtney B. Johnson ◽  
Jizhou Zhang ◽  
Daniel Lucas

Hematopoiesis in the bone marrow (BM) is the primary source of immune cells. Hematopoiesis is regulated by a diverse cellular microenvironment that supports stepwise differentiation of multipotent stem cells and progenitors into mature blood cells. Blood cell production is not static and the bone marrow has evolved to sense and respond to infection by rapidly generating immune cells that are quickly released into the circulation to replenish those that are consumed in the periphery. Unfortunately, infection also has deleterious effects injuring hematopoietic stem cells (HSC), inefficient hematopoiesis, and remodeling and destruction of the microenvironment. Despite its central role in immunity, the role of the microenvironment in the response to infection has not been systematically investigated. Here we summarize the key experimental evidence demonstrating a critical role of the bone marrow microenvironment in orchestrating the bone marrow response to infection and discuss areas of future research.


2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Lin Song ◽  
Lijuan Cao ◽  
Rui Liu ◽  
Hui Ma ◽  
Yanan Li ◽  
...  

AbstractGlucocorticoids (GC) are widely used clinically, despite the presence of significant side effects, including glucocorticoid-induced osteoporosis (GIOP). While GC are believed to act directly on osteoblasts and osteoclasts to promote osteoporosis, the detailed underlying molecular mechanism of GC-induced osteoporosis is still not fully elucidated. Here, we show that lymphocytes play a pivotal role in regulating GC-induced osteoporosis. We show that GIOP could not be induced in SCID mice that lack T cells, but it could be re-established by adoptive transfer of splenic T cells from wild-type mice. As expected, T cells in the periphery are greatly reduced by GC; instead, they accumulate in the bone marrow where they are protected from GC-induced apoptosis. These bone marrow T cells in GC-treated mice express high steady-state levels of NF-κB receptor activator ligand (RANKL), which promotes the formation and maturation of osteoclasts and induces osteoporosis. Taken together, these findings reveal a critical role for T cells in GIOP.


Blood ◽  
2005 ◽  
Vol 105 (11) ◽  
pp. 4272-4281 ◽  
Author(s):  
Miranda Buitenhuis ◽  
Hanneke W. M. van Deutekom ◽  
Liesbeth P. Verhagen ◽  
Anders Castor ◽  
Sten Eirik W. Jacobsen ◽  
...  

Abstract Inhibitor of DNA binding (Id) proteins function as inhibitors of members of the basic helix-loop-helix family of transcription factors and have been demonstrated to play an important role in regulating lymphopoiesis. However, the role of these proteins in regulation of myelopoiesis is currently unclear. In this study, we have investigated the role of Id1 and Id2 in the regulation of granulopoiesis. Id1 expression was initially up-regulated during early granulopoiesis, which was then followed by a decrease in expression during final maturation. In contrast, Id2 expression was up-regulated in terminally differentiated granulocytes. In order to determine whether Id expression plays a critical role in regulating granulopoiesis, Id1 and Id2 were ectopically expressed in CD34+ cells by retroviral transduction. Our experiments demonstrate that constitutive expression of Id1 inhibits eosinophil development, whereas in contrast neutrophil differentiation was modestly enhanced. Constitutive Id2 expression accelerates final maturation of both eosinophils and neutrophils, whereas inhibition of Id2 expression blocks differentiation of both lineages. Transplantation of β2-microglobulin-/- nonobese diabetic severe combined immunodeficient (NOD/SCID) mice with CD34+ cells ectopically expressing Id1 resulted in enhanced neutrophil development, whereas ectopic expression of Id2 induced both eosinophil and neutrophil development. These data demonstrate that both Id1 and Id2 play a critical, although differential role in granulopoiesis.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4336-4336
Author(s):  
Jumpei Teramachi ◽  
Kazuaki Miyagawa ◽  
Delgado-Calle Jesus ◽  
Jolene Windle ◽  
Noriyoshi Kurihara ◽  
...  

Multiple myeloma (MM) is largely incurable, and is characterized by devastating bone destruction caused by increased osteoclast (OCL) differentiation and bone resorption in more than 85% of MM patients. OCLs in MM not only promote bone resorption but also increase MM cell growth and drug resistance. Despite recent advances in anti-myeloma treatment, development of anti-MM drug resistance is a major limitation of MM therapy. Therefore, new treatment modalities are urgently needed to overcome drug resistance and decrease bone resorption. IGF1 is a crucial factor for tumor cell growth and survival of malignant cells, especially in MM. IGFI also contributes to development of drug resistance of MM cells to anti-MM agents, including proteasome inhibitors and immunomodulatory agents, but how OCLs contribute to drug resistance is still not clearly delineated. We found that IGF1 was highly expressed in OCLs attached to bone and bone marrow myeloid cells in vivo, and the expression levels of IGF1 in OCLs from MM bearing mice is higher than in normal OCLs. Intriguingly, OCLs produced more IGF1 (0.8 ng/ml/protein) than MM cells (not detected) and bone marrow stromal cells (BMSCs) (0.4 ng/ml/protein) in vitro. In addition, IGF1 protein expression in OCLs was upregulated (1.8 fold) by treatment with conditioned media (CM) from 5TGM1 murine MM cells, TNF-α or IL-6, major paracrine factors that are increased in the bone marrow microenvironment in MM. These results suggest that OCLs are a major source of local IGF1 in the MM bone marrow microenvironment. To further characterize the role of OCL-derived IGF1, we generated a novel mouse with targeted deletion of Igf1 in OCLs (IGF1-/--OCL), and assessed the role of OCL-derived IGF1 in drug resistance of MM cells and bone destruction. Treatment of 5TGM1 cells with bortezomib (BTZ) (3 nM, 48 hours) decreased the viability of 5TGM1 cells by 50%. Importantly, the cytotoxic effects of BTZ on MM cells were decreased (by 5%) when MM cells were cocultured with OCLs from wild type (WT) mice. In contrast, coculture of MM cells with IGF1-/--OCLs or WT-OCLs treated with IGF1 neutralizing antibody (IGF1-ab) did not block BTZ's effects on MM cell death. Consistent with these results, coculture of MM cells with IGF1-/--OCLs or WT-OCLs treated with IGF1-ab resulted in BTZ-induced caspase-dependent apoptosis in MM cells. We next examined the effects of OCLs on the signaling pathways responsible for MM cell survival. WT-OCL-CM promptly induced the phosphorylation of Akt and activation of p38, ERK and NF-κB in MM cells. However, these pathways were not activated by MM cells treated with IGF1-/--OCL-CM or IGF1-ab-treated WT-OCL-CM. Since adhesion of MM cells to BMSCs via interaction of VLA-4 and VCAM-1 plays a critical role in cell adhesion-mediated drug resistance (CAMDR) in MM, we tested if treatment of human BMSCs with human OCL-CM upregulated VCAM-1 expression. We found that OCL-CM upregulated VCAM-1 expression on BMSCs (x fold). In contrast, treatment of BMSCs with OCLs treated with IGF1-ab blocked VCAM-1 induction. These data suggest that OCL-derived IGF1 can contribute to MM cell drug resistance in the bone marrow microenvironment. We then examined the role of IGF1 inhibition on osteoclastogenesis and the bone resorption capacity of OCLs. RANK ligand induced the expression of cathepsin K and NFATc1 in CD11b+ bone marrow cells from WT mice, differentiation markers of OCLs, and the formation of TRAP-positive multinucleated OCLs. However, OCLs formed by RANK ligand treatment of CD11b+ bone marrow cells from IGF1-/- mice had markedly decreased cathepsin K and NFATc1 expression and OCL formation. Next, we tested the bone resorption capacity of OCLs formed by CD11b+ bone marrow cells from IGF1-/- mice vs. WT mice. Similar numbers of OCLs were cultured with RANK ligand on bone slices for 72 hours. The bone resorption activity of Igf1-/--OCLs was significantly decreased (70%) compared with WT-OCLs. These results suggest that OCL-derived IGF1 plays a critical role in MM drug resistance and bone destruction, and that inhibition of the effect of IGF1 in OCLs should decrease MM drug resistance and bone destruction. Disclosures Roodman: Amgen trial of Denosumab versus Zoledronate: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees.


Author(s):  
Cong He ◽  
Luoyan Sheng ◽  
Deshen Pan ◽  
Shuai Jiang ◽  
Li Ding ◽  
...  

High-grade glioma is one of the most lethal human cancers characterized by extensive tumor heterogeneity. In order to identify cellular and molecular mechanisms that drive tumor heterogeneity of this lethal disease, we performed single-cell RNA sequencing analysis of one high-grade glioma. Accordingly, we analyzed the individual cellular components in the ecosystem of this tumor. We found that tumor-associated macrophages are predominant in the immune microenvironment. Furthermore, we identified five distinct subpopulations of tumor cells, including one cycling, two OPC/NPC-like and two MES-like cell subpopulations. Moreover, we revealed the evolutionary transition from the cycling to OPC/NPC-like and MES-like cells by trajectory analysis. Importantly, we found that SPP1/CD44 interaction plays a critical role in macrophage-mediated activation of MES-like cells by exploring the cell-cell communication among all cellular components in the tumor ecosystem. Finally, we showed that high expression levels of both SPP1 and CD44 correlate with an increased infiltration of macrophages and poor prognosis of glioma patients. Taken together, this study provided a single-cell atlas of one high-grade glioma and revealed a critical role of macrophage-mediated SPP1/CD44 signaling in glioma progression, indicating that the SPP1/CD44 axis is a potential target for glioma treatment.


Blood ◽  
2010 ◽  
Vol 115 (3) ◽  
pp. 541-548 ◽  
Author(s):  
Yong Tang ◽  
Marie J. Desierto ◽  
Jichun Chen ◽  
Neal S. Young

Abstract The transcription factor T-bet is a key regulator of type 1 immune responses. We examined the role of T-bet in an animal model of immune-mediated bone marrow (BM) failure using mice carrying a germline T-bet gene deletion (T-bet−/−). In comparison with normal C57BL6 (B6) control mice, T-bet−/− mice had normal cellular composition in lymphohematopoietic tissues, but T-bet−/− lymphocytes were functionally defective. Infusion of 5 × 106 T-bet−/− lymph node (LN) cells into sublethally irradiated, major histocompatibility complex–mismatched CByB6F1 (F1) recipients failed to induce the severe marrow hypoplasia and fatal pancytopenia that is produced by injection of similar numbers of B6 LN cells. Increasing T-bet−/− LN-cell dose to 10 to 23 × 106 per recipient led to only mild hematopoietic deficiency. Recipients of T-bet−/− LN cells had no expansion in T cells or interferon-γ–producing T cells but showed a significant increase in Lin−Sca1+CD117+CD34− BM cells. Plasma transforming growth factor-β and interleukin-17 concentrations were increased in T-bet−/− LN-cell recipients, possibly a compensatory up-regulation of the Th17 immune response. Continuous infusion of interferon-γ resulted in hematopoietic suppression but did not cause T-bet−/− LN-cell expansion or BM destruction. Our data provided fresh evidence demonstrating a critical role of T-bet in immune-mediated BM failure.


2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Yanqing Gong ◽  
Jane Hoover-Plow ◽  
Ying Li

Ischemic heart disease, including myocardial infarction (MI), is the primary cause of death throughout the US. Granulocyte colony-stimulating factor (G-CSF) is used to mobilize hematopoietic progenitor and stem cells (HPSC) to improve cardiac recovery after MI. However, poor-mobilization to G-CSF is observed in 25% of patients and 10-20% of healthy donors. Therefore, a better understanding of the underlying mechanisms regulating G-CSF-induced cardiac repair may offer novel approaches for strengthening stem cell-mediated therapeutics. Our previous studies have identified an essential role of Plg in HPSC mobilization from bone marrow (BM) in response to G-CSF. Here, we investigate the role of Plg in G-CSF-stimulated cardiac repair after MI. Our data show that G-CSF significantly improves cardiac tissue repair including increasing neovascularization in the infarct area, and improving ejection fraction and LV internal diameter by echocardiogram in wild-type mice. No improvement in tissue repair and heart function by G-CSF is observed in Plg -/- mice, indicating that Plg is required for G-CSF-regulated cardiac repair after MI. To investigate whether Plg regulates HPSC recruitment to ischemia area, bone marrow transplantion (BMT) with EGFP-expressing BM cells was performed to visualize BM-derived stem cells in infarcted tissue. Our data show that G-CSF dramatically increases recruitment of GFP+ cells (by 16 fold) in WT mice but not in Plg -/- mice, suggesting that Plg is essential for HPSC recruitment from BM to the lesion sites after MI. In further studies, we investigated the role of Plg in the regulation of SDF-1/CXCR-4 axis, a major regulator for HPSC recruitment. Our results show that G-CSF significantly increases CXCR-4 expression in infarcted area in WT mice. While G-CSF-induced CXCR-4 expression is markedly decreased (80%) in Plg -/- mice, suggesting Plg may regulate CXCR-4 expression during HSPC recruitment to injured heart. Interestingly, Plg does not affect SDF-1 expression in response to G-CSF treatment. Taken together, our findings have identified a critical role of Plg in HSPC recruitment to the lesion site and subsequent tissue repair after MI. Thus, targeting Plg may offer a new therapeutic strategy to improve G-CSF-mediated cardiac repair after MI.


2019 ◽  
Vol 244 (2) ◽  
pp. 73-82 ◽  
Author(s):  
Xue Gong ◽  
Gengze Wu ◽  
Chunyu Zeng

Over the last several decades, cardiovascular diseases largely increase the morbidity and mortality especially in developed countries, affecting millions of people worldwide. Although extensive work over the last two decades attempted to decipher the molecular network of regulating the pathogenesis and progression of these diseases, evidences from clinical trials with newly revealed targets failed to show more evidently salutary effects, indicating the inefficiency of understanding the complete regulatory landscape. Recent studies have shifted their focus from coding genes to the non-coding ones, which consist of microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and the lately re-discovered a unique group of RNAs—circular RNAs (circRNAs). As the focus now has been shifted to the newly identified group of non-coding RNAs, circRNAs exhibit stability, highly conservation and relative enriched expression abundance in some cases, which are distinct from their cognate linear counterparts—lncRNAs. So far, emerging evidence begins to support the critical role of circRNAs in organogenesis and pathogenesis as exemplified in the central nervous system, and could be just as implicative in the cardiovascular system, suggesting a therapeutic perspective in related diseases. Impact statement Circular RNAs are important regulators of multiple biological processes such as organogenesis and oncogenesis. Although the bulk of concerning studies focused on revealing their diversified roles in various types of cancers, reports began to accumulate in cardiovascular field these days. We summarize circular RNAs implicated in cardiovascular diseases, aiming to highlight the advances in the knowledge of such diseases and their potential of being promising target for diagnosis and therapy.


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