Abstract 5: Neovascularization By Substance-p- Mobilized Epc And Msc In Vitro And In Vivo

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Hyun Sook Hong ◽  
Suna Kim ◽  
Youngsook Son
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Substance P ◽  
Network Formation ◽  
Skin Wound ◽  
Hematopoietic Stem ◽  
Vessel Structure

Bone marrow stem cells, especially, endothelial precursor cells (EPC), mesenchymal stem cells (MSC) or hematopoietic stem cell (HSC) are expected as reparative cells for the repair of a variety of tissue damages such as stroke and myocardial infarction, even though their role in the repair is not demonstrated. This report was investigated to find a role of Substance-p (SP) as a reparative agent in the tissue repair requiring EPC and MSC. In order to examine EPC (EPC SP ) and MSC (MSC SP ) mobilized by SP, we injected SP intravenously for consecutive 2 days and saline was injected as a vehicle. At 3 post injection, peripheral blood (PB) was collected.To get mesenchymal stem cells or endothelial progenitor cells, MNCs were incubated in MSCGM or EGM-2 respectively for 10 days. Functional characteristics of the EPC SP were proven by the capacity to form endothelial tubule network in the matrigel in vitro and in the matrigel plug assay in vivo. In contrast, MSC SP did not form a tube-like structure but formed a pellet-structure on matrigel. However, when both cells were premixed before the matrigel assay, much longer and branched tubular network was formed, in which a-SMA expressing MSC SP were decorating outside of the endothelial tube, especially enriched at the bifurcating point. MSC SP may contribute and reinforce elaborate vascular network formation in vivo by working as pericyte-like cells. Thus, the EPC SP and MSC SP were labeled with PKH green and PKH red respectively and their tubular network was examined. Well organized tubular network was formed, which was covered by PKH green labeled cells and was decorated in a punctate pattern by PKH red labeled cells. In order to investigate the role of EPC SP and MSC SP specifically in vivo, rabbit EPC SP and MSC SP were transplanted to full thickness skin wound. The vessel of EPC SP -transplanted groups was UEA-lectin+, which was not covered with a-SMA+ pericytes but EPC SP + MSC SP -transplanted groups showed, in part, a-SMA+ pericyte-encircled UEA-lectin+ vessels. This proved the specific role of MSC SP as pericytes. From these data, we have postulated that the collaboration of MSC and EPC is essential for normal vessel structure and furthermore, accelerated wound healing as ischemia diseases, which can be stimulated through by SP injection.

The Role of Nucleophosmin In Hematopoietic Stem Cells and the Pathogenesis of Myelodysplastic Syndrome

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 95-95 ◽  
Author(s):  
Keisuke Ito ◽  
Paolo Sportoletti ◽  
John G Clohessy ◽  
Grisendi Silvia ◽  
Pier Paolo Pandolfi
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Myelodysplastic Syndrome ◽  
Cell Biology ◽  
De Novo ◽  
Stem Cell Biology ◽  
Hematopoietic Stem

Abstract Abstract 95 Myelodysplastic syndrome (MDS) is an incurable stem cell disorder characterized by ineffective hematopoiesis and an increased risk of leukemia transformation. Nucleophosmin (NPM) is directly implicated in primitive hematopoiesis, the pathogenesis of hematopoietic malignancies and more recently of MDS. However, little is known regarding the molecular role and function of NPM in MDS pathogenesis and in stem cell biology. Here we present data demonstrating that NPM plays a critical role in the maintenance of hematopoietic stem cells (HSCs) and the transformation of MDS into leukemia. NPM is located on chromosome 5q and is frequently lost in therapy-related and de novo MDS. We have previously shown that Npm1 acts as a haploinsufficient tumor suppressor in the hematopoietic compartment and Npm1+/− mice develop a hematologic syndrome with features of human MDS, including increased susceptibility to leukemogenesis. As HSCs have been demonstrated to be the target of the primary neoplastic event in MDS, a functional analysis of the HSC compartment is essential to understand the molecular mechanisms in MDS pathogenesis. However, the role of NPM in adult hematopoiesis remains largely unknown as Npm1-deficiency leads to embryonic lethality. To investigate NPM function in adult hematopoiesis, we have generated conditional knockout mice of Npm1, using the Cre-loxP system. Analysis of Npm1 conditional mutants crossed with Mx1-Cre transgenic mice reveals that Npm1 plays a crucial role in adult hematopoiesis and ablation of Npm1 in adult HSCs leads to aberrant cycling and followed by apoptosis. Analysis of cell cycle status revealed that HSCs are impaired in their ability to maintain quiescence after Npm1-deletion and are rapidly depleted in vivo as well as in vitro. Competitive reconstitution assay revealed that Npm1 acts cell-autonomously to maintain HSCs. Conditional inactivation of Npm1 leads to an MDS phenotype including a profoundly impaired ability to differentiate into cells of the erythroid lineage, megakaryocyte dyspoiesis and centrosome amplification. Furthermore, Npm1 loss evokes a p53-dependent response and Npm1-deleted HSCs undergo apoptosis in vivo and in vitro. Strikingly, transfer of the Npm1 mutation into a p53-null background rescued the apoptosis of Npm1-ablated HSCs and resulted in accelerated transformation to an aggressive and lethal form of acute myeloid leukemia. Our findings highlight the crucial role of NPM in stem cell biology and identify a new mechanism by which MDS can progress to leukemia. This has important therapeutic implications for de novo MDS as well as therapy-related MDS, which is known to rapidly evolve to leukemia with frequent loss or mutation of TRP53. Disclosures: No relevant conflicts of interest to declare.

scholarly journals The critical role of agrin in the hematopoietic stem cell niche

Blood ◽  
2011 ◽  
Vol 118 (10) ◽  
pp. 2733-2742 ◽  
Author(s):  
Cristina Mazzon ◽  
Achille Anselmo ◽  
Javier Cibella ◽  
Cristiana Soldani ◽  
Annarita Destro ◽  
...  
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Critical Role ◽  
Hematopoietic Stem ◽  
Hematopoietic Stem Cell Niche ◽  
Cell Niche ◽  
Deficient Mice

Abstract Hematopoiesis is the process leading to the sustained production of blood cells by hematopoietic stem cells (HSCs). Growth, survival, and differentiation of HSCs occur in specialized microenvironments called “hematopoietic niches,” through molecular cues that are only partially understood. Here we show that agrin, a proteoglycan involved in the neuromuscular junction, is a critical niche-derived signal that controls survival and proliferation of HSCs. Agrin is expressed by multipotent nonhematopoietic mesenchymal stem cells (MSCs) and by differentiated osteoblasts lining the endosteal bone surface, whereas Lin−Sca1+c-Kit+ (LSK) cells express the α-dystroglycan receptor for agrin. In vitro, agrin-deficient MSCs were less efficient in supporting proliferation of mouse Lin−c-Kit+ cells, suggesting that agrin plays a role in the hematopoietic cell development. These results were indeed confirmed in vivo through the analysis of agrin knockout mice (Musk-L;Agrn−/−). Agrin-deficient mice displayed in vivo apoptosis of CD34+CD135− LSK cells and impaired hematopoiesis, both of which were reverted by an agrin-sufficient stroma. These data unveil a crucial role of agrin in the hematopoietic niches and in the cross-talk between stromal and hematopoietic stem cells.

scholarly journals Rheb1-Deficient Neutrophils Promote Hematopoietic Stem/Progenitor Cell Proliferation via Mesenchymal Stem Cells

2021 ◽  
Vol 9 ◽  
Author(s):  
Juan Gao ◽  
Shuaibing Hou ◽  
Shengnan Yuan ◽  
Yuxia Wang ◽  
Yanan Gao ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Myeloid Cells ◽  
Human Mscs ◽  
Hematopoietic Stem ◽  
Progenitor Cell Proliferation ◽  
High Level ◽  
Lower Expression

Myeloid cells have been identified as hematopoietic stem cell (HSC)-regulating cells. However, the mechanisms by which myeloid cells regulate the function of HSCs are not fully defined. Our previous study indicated that the HSCs are over-expanded in Vav1-Cre;Rheb1fl/fl mice. Here, using in vivo and in vitro models, we found that Rheb1-deficient neutrophils remodeled the bone marrow environment and induced expansion of HSCs in vivo. Further studies showed that loss of Rheb1 impaired neutrophils’ ability to secrete IL-6, led mesenchymal stem cells (MSCs) to produce more SCF, and promote HSC proliferation. We further found that IL-6 suppressed SCF mRNA expression in human MSCs. Interesting, the high level of IL-6 was also related with poor survival of chronic myeloid leukemia (CML) patients, and higher expression of IL-6 in CML cells is associated with the lower expression of SCF in MSCs in patients. Our studies suggested that blocking IL-6 signaling pathway might stimulate MSCs to secrete more SCF, and to support hematopoietic stem/progenitor cells proliferation.

scholarly journals Bone Marrow-Derived Mesenchymal Stem Cells Modified with Akt1 Ameliorates Acute Liver GVHD

2019 ◽  
Vol 21 (1) ◽  
Author(s):  
Lukun Zhou ◽  
Shuang Liu ◽  
Zhao Wang ◽  
Jianfeng Yao ◽  
Wenbin Cao ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Liver Injury ◽  
Therapeutic Effects ◽  
Hematopoietic Stem ◽  
Ifn Γ ◽  
Immunomodulatory Function

Abstract Background Liver injury associated with acute graft-versus-host disease (aGVHD) is a frequent and severe complication of hematopoietic stem cell transplantation and remains a major cause of transplant-related mortality. Bone marrow-derived mesenchymal stem cells (BM-MSCs) has been proposed as a potential therapeutic approach for aGVHD. However, the therapeutic effects are not always achieved. In this study, we genetically engineered C57BL/6 mouse BM-MSCs with AKT1 gene and tested whether AKT1-MSCs was superior to control MSCs (Null-MSCs) for cell therapy of liver aGVHD. Results In vitro apoptosis analyses showed that, under both routine culture condition and high concentration interferon-γ (IFN-γ) (100ng/mL) stimulation condition, AKT1-MSCs had a survival (anti-apoptotic) advantage compared to Null-MSCs. In vivo imaging showed that AKT1-MSCs had better homing capacity and longer persistence in injured liver compared to Null-MSCs. Most importantly, AKT1-MSCs demonstrated an enhanced immunomodulatory function by releasing more immunosuppressive cytokines, such as IL-10. Adoptive transfer of AKT1-MSCs mitigated the histopathological abnormalities of concanavalin A(ConA)-induced liver injury along with significantly lowered serum levels of ALT and AST. The attenuation of liver injury correlated with the decrease of TNF-α and IFN-γ both in liver tissue and in the serum. Conclusions In summary, BM-MSCs genetically modified with AKT1 has a survival advantage and an enhanced immunomodulatory function both in vitro and in vivo and thus demonstrates the therapeutic potential for prevention and amelioration of liver GVHD and other immunity-associated liver injuries.

scholarly journals Mesenchymal Stem Cells Regulate the Innate and Adaptive Immune Responses Dampening Arthritis Progression

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
R. A. Contreras ◽  
F. E. Figueroa ◽  
F. Djouad ◽  
P. Luz-Crawford
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Therapeutic Potential ◽  
Multipotent Stem Cells ◽  
Immune Systems ◽  
Adaptive Immune ◽  
Adaptive Immune Systems

Mesenchymal stem cells (MSCs) are multipotent stem cells that are able to immunomodulate cells from both the innate and the adaptive immune systems promoting an anti-inflammatory environment. During the last decade, MSCs have been intensively studiedin vitroandin vivoin experimental animal model of autoimmune and inflammatory disorders. Based on these studies, MSCs are currently widely used for the treatment of autoimmune diseases such as rheumatoid arthritis (RA) characterized by complex deregulation of the immune systems. However, the therapeutic properties of MSCs in arthritis are still controverted. These controversies might be due to the diversity of MSC sources and isolation protocols used, the time, the route and dose of MSC administration, the variety of the mechanisms involved in the MSCs suppressive effects, and the complexity of arthritis pathogenesis. In this review, we discuss the role of the interactions between MSCs and the different immune cells associated with arthritis pathogenesis and the possible means described in the literature that could enhance MSCs therapeutic potential counteracting arthritis development and progression.

scholarly journals Macrophage-derived Apoptotic Vesicles Regulate Fate Commitment of Mesenchymal Stem Cells via miR155

2021 ◽  
Author(s):  
Yuan Zhu ◽  
Xiao Zhang ◽  
Kunkun Yang ◽  
Yuzi Shao ◽  
Ranli Gu ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Western Blot ◽  
Molecular Mechanisms ◽  
Proliferation Ability ◽  
Immunomodulatory Function

Abstract Background In tissue engineering, mesenchymal stem cells (MSCs) are common seed cells because of abundant sources, strong proliferation ability and immunomodulatory function. Numerous researches have demonstrated that MSC-macrophage crosstalk played a key role in the tissue engineering. Macrophages could regulate the differentiation of MSCs via different molecular mechanisms, including extracellular vesicles. Apoptotic macrophages could generate large amounts of apoptotic vesicles (apoVs), whereas the functions of macrophage-derived apoVs remain largely unknown. There was no research to clarify the role of macrophage-derived apoVs in MSC fate choices. In this study, we aimed to characterize macrophage-derived apoVs, and investigate the roles of macrophage-derived apoVs in the fate commitment of MSCs. Methods We characterized macrophage-derived apoVs, and investigated their role in MSC osteogenesis and adipogenesis in vitro and in vivo. Furthermore, we performed microRNA loss- and gain- of function experiments and western blot to determine the molecular mechanism. Results We found that macrophage-derived apoVs inhibited osteogenesis and promoted adipogenesis in vitro and in vivo. In mechanism, apoVs regulated osteogenesis and adipogenesis of MSCs by delivering microRNA155 (miR155). Conclusions Macrophage-derived apoVs could regulate the osteogenesis and adipogenesis of MSCs through delivering miR155, which provided novel insights for MSC-mediated tissue engineering.

scholarly journals Exosomal LncRNA–NEAT1 derived from MIF-treated mesenchymal stem cells protected against doxorubicin-induced cardiac senescence through sponging miR-221-3p

2020 ◽  
Author(s):  
Lei Zhuang ◽  
Wenzheng Xia ◽  
Didi Chen ◽  
Yijia Ye ◽  
Tingting Hu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Therapeutic Effect ◽  
Macrophage Migration Inhibitory Factor ◽  
Luciferase Assay ◽  
Control Mscs ◽  
Lncrna Neat1

Abstract AIMS: The chemotherapy drug doxorubicin (Dox) is widely used for treating a variety of cancers. However, its high cardiotoxicity hampered its clinical use. Exosomes derived from stem cells showed a therapeutic effect against Dox-induced cardiomyopathy (DIC). Previous studies reported that exosomes derived from mesenchymal stem cells (MSCs) pretreated with macrophage migration inhibitory factor (MIF) (exosomeMIF) showed a cardioprotective effect through modulating long noncoding RNAs/microRNAs (lncRNAs/miRs). This study aimed to investigate the role of exosomeMIF in the treatment of DIC. METHODS AND RESULTS: Exosomes were isolated from control MSCs (exosome) and MIF-pretreated MSCs (exosomeMIF). Regulatory lncRNAs activated by MIF pretreatment were explored using genomics approaches. Fluorescence-labeled exosomes were tracked in vitro by fluorescence imaging. In vivo and in vitro, miR-221-3p mimic transfection enforced miR-221-3p overexpression, and senescence-associated β-galactosidase assay was applied to test cellular senescence. Exosomal delivering LncRNA-NEAT1 induced therapeutic effect in vivo was confirmed by echocardiography. It demonstrated that exosomesMIF recovered the cardiac function and exerted the anti-senescent effect through LncRNA–NEAT1 transfer against Dox. TargetScan and luciferase assay showed that miR-221-3p targeted the Sirt2 3'-untranslated region. Silencing LncRNA–NEAT1 in MSCs, miR-221-3p overexpression or Sirt2 silencing in cardiomyocytes ruined the exosomeMIF-induced anti-senescent effect against Dox. CONCLUSIONS: The results indicated exosomeMIF serving as a promising anti-senescent effector against Dox-induced cardiotoxicity through LncRNA–NEAT1 transfer, thus sponging miR-221-3p and leading to Sirt2 activation. The study proposed that exosomeMIF might have the potential to serve as a cardioprotective therapeutic agent during cancer chemotherapy.

scholarly journals Exosomes Secreted from CXCR4 Overexpressing Mesenchymal Stem Cells Promote Cardioprotection via Akt Signaling Pathway following Myocardial Infarction

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Kai Kang ◽  
Ruilian Ma ◽  
Wenfeng Cai ◽  
Wei Huang ◽  
Christian Paul ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Infarct Size ◽  
Functional Restoration ◽  
Akt Inhibitor ◽  
Cardiac Functions

Background and Objective.Exosomes secreted from mesenchymal stem cells (MSC) have demonstrated cardioprotective effects. This study examined the role of exosomes derived from MSC overexpressing CXCR4 for recovery of cardiac functions after myocardial infarction (MI).Methods. In vitro, exosomes from MSC transduced with lentiviral CXCR4 (ExoCR4) encoding a silencing sequence or null vector were isolated and characterized by transmission electron microscopy and dynamic light scattering. Gene expression was then analyzed by qPCR and Western blotting. Cytoprotective effects on cardiomyocytes were evaluated and effects of exosomes on angiogenesis analyzed.In vivo, an exosome-pretreated MSC-sheet was implanted into a region of scarred myocardium in a rat MI model. Angiogenesis, infarct size, and cardiac functions were then analyzed.Results. In vitro, ExoCR4significantly upregulatedIGF-1αand pAkt levels and downregulated active caspase 3 levelin cardiomyocytes. ExoCR4also enhanced VEGF expression and vessel formation. However, effects of ExoCR4were abolished by an Akt inhibitor or CXCR4 knockdown.In vivo, ExoCR4treated MSC-sheet implantation promoted cardiac functional restoration by increasing angiogenesis, reducing infarct size, and improving cardiac remodeling.Conclusions.This study reveals a novel role of exosomes derived from MSCCR4and highlights a new mechanism of intercellular mediation of stem cells for MI treatment.

scholarly journals The Role of Apoptosis in the Regulation of Hematopoietic Stem Cells

2000 ◽  
Vol 191 (2) ◽  
pp. 253-264 ◽  
Author(s):  
Jos Domen ◽  
Samuel H. Cheshier ◽  
Irving L. Weissman
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Hematopoietic Cells ◽  
Wild Type ◽  
Direct Role ◽  
Hematopoietic Stem

Hematopoietic stem cells (HSC) give rise to cells of all hematopoietic lineages, many of which are short lived. HSC face developmental choices: self-renewal (remain an HSC with long-term multilineage repopulating potential) or differentiation (become an HSC with short-term multilineage repopulating potential and, eventually, a mature cell). There is a large overcapacity of differentiating hematopoietic cells and apoptosis plays a role in regulating their numbers. It is not clear whether apoptosis plays a direct role in regulating HSC numbers. To address this, we have employed a transgenic mouse model that overexpresses BCL-2 in all hematopoietic cells, including HSC: H2K-BCL-2. Cells from H2K-BCL-2 mice have been shown to be protected against a wide variety of apoptosis-inducing challenges. This block in apoptosis affects their HSC compartment. H2K-BCL-2–transgenic mice have increased numbers of HSC in bone marrow (2.4× wild type), but fewer of these cells are in the S/G2/M phases of the cell cycle (0.6× wild type). Their HSC have an increased plating efficiency in vitro, engraft at least as well as wild-type HSC in vivo, and have an advantage following competitive reconstitution with wild-type HSC.

scholarly journals Exosomal LncRNA–NEAT1 derived from MIF-treated mesenchymal stem cells protected against doxorubicin-induced cardiac senescence through sponging miR-221-3p

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Lei Zhuang ◽  
Wenzheng Xia ◽  
Didi Chen ◽  
Yijia Ye ◽  
Tingting Hu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Therapeutic Effect ◽  
Macrophage Migration Inhibitory Factor ◽  
Luciferase Assay ◽  
Control Mscs ◽  
Lncrna Neat1

Abstract Background The chemotherapy drug doxorubicin (Dox) is widely used for treating a variety of cancers. However, its high cardiotoxicity hampered its clinical use. Exosomes derived from stem cells showed a therapeutic effect against Dox-induced cardiomyopathy (DIC). Previous studies reported that exosomes derived from mesenchymal stem cells (MSCs) pretreated with macrophage migration inhibitory factor (MIF) (exosomeMIF) showed a cardioprotective effect through modulating long noncoding RNAs/microRNAs (lncRNAs/miRs). This study aimed to investigate the role of exosomeMIF in the treatment of DIC. Results Exosomes were isolated from control MSCs (exosome) and MIF-pretreated MSCs (exosomeMIF). Regulatory lncRNAs activated by MIF pretreatment were explored using genomics approaches. Fluorescence-labeled exosomes were tracked in vitro by fluorescence imaging. In vivo and in vitro, miR-221-3p mimic transfection enforced miR-221-3p overexpression, and senescence-associated β-galactosidase assay was applied to test cellular senescence. Exosomal delivering LncRNA-NEAT1 induced therapeutic effect in vivo was confirmed by echocardiography. It demonstrated that exosomesMIF recovered the cardiac function and exerted the anti-senescent effect through LncRNA–NEAT1 transfer against Dox. TargetScan and luciferase assay showed that miR-221-3p targeted the Sirt2 3′-untranslated region. Silencing LncRNA–NEAT1 in MSCs, miR-221-3p overexpression or Sirt2 silencing in cardiomyocytes decreased the exosomeMIF-induced anti-senescent effect against Dox. Conclusions The results indicated exosomeMIF serving as a promising anti-senescent effector against Dox-induced cardiotoxicity through LncRNA–NEAT1 transfer, thus inhibiting miR-221-3p and leading to Sirt2 activation. The study proposed that exosomeMIF might have the potential to serve as a cardioprotective therapeutic agent during cancer chemotherapy.

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