scholarly journals Tsc1 Regulates the Proliferation Capacity of Bone-Marrow Derived Mesenchymal Stem Cells

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 2072 ◽  
Author(s):  
Maria V. Guijarro ◽  
Laura S. Danielson ◽  
Marta Cañamero ◽  
Akbar Nawab ◽  
Carolina Abrahan ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Myogenic Differentiation ◽  
Negative Regulator ◽  
Benign Tumors ◽  
Hematopoietic Stem ◽  
The Impact

TSC1 is a tumor suppressor that inhibits cell growth via negative regulation of the mammalian target of rapamycin complex (mTORC1). TSC1 mutations are associated with Tuberous Sclerosis Complex (TSC), characterized by multiple benign tumors of mesenchymal and epithelial origin. TSC1 modulates self-renewal and differentiation in hematopoietic stem cells; however, its effects on mesenchymal stem cells (MSCs) are unknown. We investigated the impact of Tsc1 inactivation in murine bone marrow (BM)-MSCs, using tissue-specific, transgelin (Tagln)-mediated cre-recombination, targeting both BM-MSCs and smooth muscle cells. Tsc1 mutants were viable, but homozygous inactivation led to a dwarfed appearance with TSC-like pathologies in multiple organs and reduced survival. In young (28 day old) mice, Tsc1 deficiency-induced significant cell expansion of non-hematopoietic BM in vivo, and MSC colony-forming potential in vitro, that was normalized upon treatment with the mTOR inhibitor, everolimus. The hyperproliferative BM-MSC phenotype was lost in aged (1.5 yr) mice, and Tsc1 inactivation was also accompanied by elevated ROS and increased senescence. ShRNA-mediated knockdown of Tsc1 in BM-MSCs replicated the hyperproliferative BM-MSC phenotype and led to impaired adipogenic and myogenic differentiation. Our data show that Tsc1 is a negative regulator of BM-MSC proliferation and support a pivotal role for the Tsc1-mTOR axis in the maintenance of the mesenchymal progenitor pool.

Sqstm1 Is Required to Retain Hematopoietic Stem Cell/ Progenitors As a Negative Regulator of Macrophage-Dependent Inflammatory Signaling in the Bone Marrow Osteoblastic Niche

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 350-350
Author(s):  
Kyung-Hee Chang ◽  
Amitava Sengupta ◽  
Ramesh C Nayak ◽  
Angeles Duran ◽  
Sang Jun Lee ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Hematopoietic Stem Cells ◽  
Research Funding ◽  
Negative Regulator ◽  
Wild Type ◽  
Hematopoietic Stem ◽  
P Retention

Abstract In the bone marrow (BM), hematopoietic stem cells and progenitors (HSC/P) reside in specific anatomical niches. Among these niches, a functional osteoblast (Ob)-macrophage (MΦ) niche has been described where Ob and MΦ (so called "osteomacs") are in direct relationship. A connection between innate immunity surveillance and traffic of hematopoietic stem cells/progenitors (HSC/P) has been demonstrated but the regulatory signals that instruct immune regulation from MΦ and Ob on HSC/P circulation are unknown. The adaptor protein sequestosome 1 (Sqstm1), contains a Phox bemp1 (PB1) domain which regulates signal specificities through PB1-PB1 scaffolding and processes of autophagy. Using microenvironment and osteoblast-specific mice deficient in Sqstm1, we discovered that the deficiency of Sqstm1 results in macrophage contact-dependent activation of Ob IKK/NF-κB, in vitro and in vivo repression of Ccl4 (a CCR5 binding chemokine that has been shown to modulate microenvironment Cxcl12-mediated responses of HSC/P), HSC/P egress and deficient BM homing of wild-type HSC/P. Interestingly, while Ccl4 expression is practically undetectable in wild-type or Sqstm1-/- Ob, primary Ob co-cultured with wild-type BM-derived MΦ strongly upregulate Ccl4 expression, which returns to normal levels upon genetic deletion of Ob Sqstm1. We discovered that MΦ can activate an inflammatory pathway in wild-type Ob which include upregulation of activated focal adhesion kinase (p-FAK), IκB kinase (IKK), nuclear factor (NF)-κB and Ccl4 expression through direct cell-to-cell interaction. Sqstm1-/- Ob cocultured with MΦ strongly upregulated p-IKBα and NF-κB activity, downregulated Ccl4 expression and secretion and repressed osteogenesis. Forced expression of Sqstm1, but not of an oligomerization-deficient mutant, in Sqstm1-/- Ob restored normal levels of p-IKBα, NF-κB activity, Ccl4 expression and osteogenic differentiation, indicating that Sqstm1 dependent Ccl4 expression depends on localization to the autophagosome formation site. Finally, Ob Sqstm1 deficiency results in upregulation of Nbr1, a protein containing a PB1 interacting domain. Combined deficiency of Sqstm1 and Nbr1 rescues all in vivo and in vitro phenotypes of Sqstm1 deficiency related to osteogenesis and HSC/P egression in vivo. Together, this data indicated that Sqstm1 oligomerization and functional repression of its PB1 binding partner Nbr1 are required for Ob dependent Ccl4 production and HSC/P retention, resulting in a functional signaling network affecting at least three cell types. A functional ‘MΦ-Ob niche’ is required for HSC/P retention where Ob Sqstm1 is a negative regulator of MΦ dependent Ob NF-κB activation, Ob differentiation and BM HSC/P traffic to circulation. Disclosures Starczynowski: Celgene: Research Funding. Cancelas:Cerus Co: Research Funding; P2D Inc: Employment; Terumo BCT: Research Funding; Haemonetics Inc: Research Funding; MacoPharma LLC: Research Funding; Therapure Inc.: Consultancy, Research Funding; Biomedical Excellence for Safer Transfusion: Research Funding; New Health Sciences Inc: Consultancy.

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.

Interferon-Gamma Impairs the Self-Renewal of Hematopoietic Stem Cells

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2351-2351
Author(s):  
Alexander M. de Bruin ◽  
Berend Hooibrink ◽  
Martijn A. Nolte
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Hematopoietic Stem Cells ◽  
Interferon Gamma ◽  
Chimeric Mice ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
The Impact

Abstract Abstract 2351 Regulation of hematopoiesis during stress situations, such as bacterial or viral infections, is crucial for the maintenance of sufficient numbers of cells in the blood. It has become clear that activated immune cells provide such feedback signals to the bone marrow. An important mediator in this respect is the pro-inflammatory cytokine Interferon-gamma (IFNγ), which is produced in the bone marrow by activated T cells during the course of an infection. As such, we have previously shown that T cell-derived IFNγ can directly influence the output of myeloid and erythroid cells. To address whether IFNγ can also influence the function of hematopoietic stem cells (HSCs), we cultured highly purified HSCs from murine bone marrow with or without IFNγ and found that IFNγ strongly reduced the absolute number of HSCs in these cultures, both phenotypically and functionally. We confirmed that the functional impact of IFNγ was due to a direct effect on HSCs and not mediated by more differentiated progenitors. In addition, IFNγ does not directly influence the quiescent state of purified HSC, nor their cell cycle entry. By labeling HSCs with CFSE, we found that IFNγ reduces HSC expansion in vitro by decreasing their proliferative capacity, but not their ability to differentiate. To investigate the impact of IFNγ on HSCs in vivo, we infected WT and IFNγ−/− mice with lymphocytic choriomeningitis virus (LCMV) and found that IFNγ severely impaired HSC recovery upon infection. Finally, to exclude indirect effects of IFNγ on other cell types we generated chimeric mice with bone marrow from both WT and IFNγR−/− mice. Infection of these mixed-chimeric mice with LCMV resulted in decreased recovery of WT HSCs, but not of IFNγR−/− HSCs in the same mouse, which formally demonstrates that IFNγ directly impairs the proliferation of HSCs in vivo. Based on these experiments we conclude that IFNγ reduces HSC self renewal both in vitro and in vivo. Importantly, we thereby challenge the current concept in literature that IFNγ would induce the proliferation of HSCs (Baldridge et al, Nature 2010). Our findings thus provide challenging new insight regarding the impact of immune activation on hematopoiesis and will contribute significantly to the scientific discussion concerning this process. Moreover, our data also provide an explanation for the occurrence of anemia and bone marrow failure in several human diseases in which IFNγ is chronically produced. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Comparative analysis of mouse bone marrow and adipose tissue mesenchymal stem cells for critical limb ischemia cell therapy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pegah Nammian ◽  
Seyedeh-Leili Asadi-Yousefabad ◽  
Sajad Daneshi ◽  
Mohammad Hasan Sheikhha ◽  
Seyed Mohammad Bagher Tabei ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Adipose Tissue ◽  
Cell Therapy ◽  
Femoral Artery ◽  
Critical Limb Ischemia ◽  
Limb Ischemia

Abstract Introduction Critical limb ischemia (CLI) is the most advanced form of peripheral arterial disease (PAD) characterized by ischemic rest pain and non-healing ulcers. Currently, the standard therapy for CLI is the surgical reconstruction and endovascular therapy or limb amputation for patients with no treatment options. Neovasculogenesis induced by mesenchymal stem cells (MSCs) therapy is a promising approach to improve CLI. Owing to their angiogenic and immunomodulatory potential, MSCs are perfect candidates for the treatment of CLI. The purpose of this study was to determine and compare the in vitro and in vivo effects of allogeneic bone marrow mesenchymal stem cells (BM-MSCs) and adipose tissue mesenchymal stem cells (AT-MSCs) on CLI treatment. Methods For the first step, BM-MSCs and AT-MSCs were isolated and characterized for the characteristic MSC phenotypes. Then, femoral artery ligation and total excision of the femoral artery were performed on C57BL/6 mice to create a CLI model. The cells were evaluated for their in vitro and in vivo biological characteristics for CLI cell therapy. In order to determine these characteristics, the following tests were performed: morphology, flow cytometry, differentiation to osteocyte and adipocyte, wound healing assay, and behavioral tests including Tarlov, Ischemia, Modified ischemia, Function and the grade of limb necrosis scores, donor cell survival assay, and histological analysis. Results Our cellular and functional tests indicated that during 28 days after cell transplantation, BM-MSCs had a great effect on endothelial cell migration, muscle restructure, functional improvements, and neovascularization in ischemic tissues compared with AT-MSCs and control groups. Conclusions Allogeneic BM-MSC transplantation resulted in a more effective recovery from critical limb ischemia compared to AT-MSCs transplantation. In fact, BM-MSC transplantation could be considered as a promising therapy for diseases with insufficient angiogenesis including hindlimb ischemia.

scholarly journals Transcription factor Gfi-1 induced by G-CSF is a negative regulator of CXCR4 in myeloid cells

Blood ◽  
2007 ◽  
Vol 110 (7) ◽  
pp. 2276-2285 ◽  
Author(s):  
Maria De La Luz Sierra ◽  
Paola Gasperini ◽  
Peter J. McCormick ◽  
Jinfang Zhu ◽  
Giovanna Tosato
Keyword(s):  
Bone Marrow ◽  
Dna Sequences ◽  
Peripheral Blood ◽  
Cell Function ◽  
Myeloid Cell ◽  
Cxcr4 Expression ◽  
Negative Regulator ◽  
Hematopoietic Stem

The mechanisms underlying granulocyte-colony stimulating factor (G-CSF)–induced mobilization of granulocytic lineage cells from the bone marrow to the peripheral blood remain elusive. We provide evidence that the transcriptional repressor growth factor independence-1 (Gfi-1) is involved in G-CSF–induced mobilization of granulocytic lineage cells from the bone marrow to the peripheral blood. We show that in vitro and in vivo G-CSF promotes expression of Gfi-1 and down-regulates expression of CXCR4, a chemokine receptor essential for the retention of hematopoietic stem cells and granulocytic cells in the bone marrow. Gfi-1 binds to DNA sequences upstream of the CXCR4 gene and represses CXCR4 expression in myeloid lineage cells. As a consequence, myeloid cell responses to the CXCR4 unique ligand SDF-1 are reduced. Thus, Gfi-1 not only regulates hematopoietic stem cell function and myeloid cell development but also probably promotes the release of granulocytic lineage cells from the bone marrow to the peripheral blood by reducing CXCR4 expression and function.

Effect of Substrate Elasticity on In Vitro Aging of Human Mesenchymal Stem Cells

2012 ◽  
Vol 1498 ◽  
pp. 39-45
Author(s):  
Courtney E. LeBlon ◽  
Caitlin R. Fodor ◽  
Tony Zhang ◽  
Xiaohui Zhang ◽  
Sabrina S. Jedlicka
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Elastic Modulus ◽  
Myogenic Differentiation ◽  
Human Mesenchymal Stem Cells ◽  
Immunofluorescent Staining ◽  
Differentiation Potential ◽  
Gene And Protein Expression ◽  
The Impact

ABSTRACTHuman mesenchymal stem cells (hMSCs) were routinely cultured on tissue-culture polystyrene (TCPS) to investigate the in vitro aging and cell stiffening. hMSCs were also cultured on thermoplastic polyurethane (TPU), which is a biocompatible polymer with an elastic modulus of approximately 12.9MPa, to investigate the impact of substrate elastic modulus on cell stiffening and differentiation potential. Cells were passaged over several generations on each material. At each passage, cells were subjected to osteogenic and myogenic differentiation. Local cell elastic modulus was measured at every passage using atomic force microscopy (AFM) indentation. Gene and protein expression was examined using qRT-PCR and immunofluorescent staining, respectively, for osteogenic and myogenic markers. Results show that the success of myogenic differentiation is highly reliant on the elastic modulus of the undifferentiated cells. The success of osteogenic differentiations is most likely somewhat dependent on the cell elastic modulus, as differentiations were more successful in earlier passages, when cells were softer.

Recombinant human BMP-2 accelerates the migration of bone marrow mesenchymal stem cells via the CDC42/PAK1/LIMK1 pathway in vitro and in vivo

2019 ◽  
Vol 7 (1) ◽  
pp. 362-372 ◽  
Author(s):  
Shuhao Liu ◽  
Yang Liu ◽  
Libo Jiang ◽  
Zheng Li ◽  
Soomin Lee ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Marrow Mesenchymal Stem Cells

BMP-2-induced migration of BMSCs can be inhibited by silencing CDC42 in vitro and in vivo.

scholarly journals Melatonin Inhibits the Ferroptotic Pathway in Rat Bone Marrow Mesenchymal Stem Cells by Activating the PI3K-AKT-mTOR Signaling Axis to Attenuate Steroid-induced Osteoporosis

2021 ◽  
Author(s):  
meng li ◽  
ning yang ◽  
li hao ◽  
wei zhou ◽  
lei li ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Mammalian Target Of Rapamycin ◽  
Mtor Signaling ◽  
High Dose ◽  
Treatment Pathways ◽  
Marrow Mesenchymal Stem Cells

Abstract ObjectivesSteroid-induced osteoporosis (SIOP) is a secondary osteoporosis, which is a systemic bone disease characterized by low bone mass, bone microstructure damage, increased bone fragility, and easy fracture. However, the specific mechanism remains unclear. Glucocorticoid-induced death of osteoblasts and bone marrow mesenchymal stem cells (BMSCs) is an important factor in SIOP. Ferroptosis is an iron-dependent programmed cell death that differs from apoptosis, cell necrosis, and autophagy, which can be induced by many factors. Herein, we aimed to explore whether glucocorticoids (GCs) cause ferroptosis in BMSCs and determine possible treatment pathways and mechanisms of action. Melatonin (MT), a hormone secreted by the pineal gland, displays strong antioxidant abilities to scavenge free radicals and alleviates ferroptosis in many tissues and organs. MethodsIn this study, we used high-dose dexamethasone (DEX) to observe whether glucocorticoids induced ferroptosis in BMSCs. We then assessed whether MT can inhibit the ferroptotic pathway, thereby providing early protection against GC-induced SIOP, and investigated the signaling pathways involved.ResultsIn vitro experiments showed that MT intervention significantly improved GC-induced ferroptosis in BMSCs and significantly improved SIOP in vivo. Pathway analysis showed that MT improves ferroptosis by activating the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) axis. MT upregulates expression of PI3K, which is an important regulator of ferroptosis resistance. PI3K activators mimic the anti-ferroptosis effect of MT, but after blocking the PI3K pathway, the effect of MT is weakened. Obviously, MT can protect against SIOP induced by GC. Notably, even after GC-induced ferroptosis begins, MT can confer protection against SIOP. ConclusionOur research confirms that GC-induced ferroptosis is closely related to SIOP. Melatonin can inhibit ferroptosis by activating the PI3K-AKT-mTOR signaling pathway, thereby reducing the occurrence of steroid-induced osteoporosis. Therefore, MT may provide a novel strategy for preventing and treating SIOP.

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