scholarly journals Bmi1 Augments Proliferation and Survival of Cortical Bone-Derived Stem Cells after Injury through Novel Epigenetic Signaling via Histone 3 Regulation

2021 ◽  
Vol 22 (15) ◽  
pp. 7813
Author(s):  
Lindsay Kraus ◽  
Chris Bryan ◽  
Marcus Wagner ◽  
Tabito Kino ◽  
Melissa Gunchenko ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Dna Damage ◽  
Stem Cell ◽  
Histone Modification ◽  
Epigenetic Regulation ◽  
Critical Role ◽  
Proliferative Potential ◽  
Therapeutic Effects ◽  
Histone 3

Ischemic heart disease can lead to myocardial infarction (MI), a major cause of morbidity and mortality worldwide. Multiple stem cell types have been safely transferred into failing human hearts, but the overall clinical cardiovascular benefits have been modest. Therefore, there is a dire need to understand the basic biology of stem cells to enhance therapeutic effects. Bmi1 is part of the polycomb repressive complex 1 (PRC1) that is involved in different processes including proliferation, survival and differentiation of stem cells. We isolated cortical bones stem cells (CBSCs) from bone stroma, and they express significantly high levels of Bmi1 compared to mesenchymal stem cells (MSCs) and cardiac-derived stem cells (CDCs). Using lentiviral transduction, Bmi1 was knocked down in the CBSCs to determine the effect of loss of Bmi1 on proliferation and survival potential with or without Bmi1 in CBSCs. Our data show that with the loss of Bmi1, there is a decrease in CBSC ability to proliferate and survive during stress. This loss of functionality is attributed to changes in histone modification, specifically histone 3 lysine 27 (H3K27). Without the proper epigenetic regulation, due to the loss of the polycomb protein in CBSCs, there is a significant decrease in cell cycle proteins, including Cyclin B, E2F, and WEE as well as an increase in DNA damage genes, including ataxia-telangiectasia mutated (ATM) and ATM and Rad3-related (ATR). In conclusion, in the absence of Bmi1, CBSCs lose their proliferative potential, have increased DNA damage and apoptosis, and more cell cycle arrest due to changes in epigenetic modifications. Consequently, Bmi1 plays a critical role in stem cell proliferation and survival through cell cycle regulation, specifically in the CBSCs. This regulation is associated with the histone modification and regulation of Bmi1, therefore indicating a novel mechanism of Bmi1 and the epigenetic regulation of stem cells.

scholarly journals Quiescent, Slow-Cycling Stem Cell Populations in Cancer: A Review of the Evidence and Discussion of Significance

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Nathan Moore ◽  
Stephen Lyle
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Stem Cell ◽  
Cancer Stem Cells ◽  
Adult Stem Cells ◽  
Cell Populations ◽  
Proliferative Potential ◽  
Cell Cycle Regulators ◽  
Slow Cycling ◽  
Stem Cell Populations

Long-lived cancer stem cells (CSCs) with indefinite proliferative potential have been identified in multiple epithelial cancer types. These cells are likely derived from transformed adult stem cells and are thought to share many characteristics with their parental population, including a quiescent slow-cycling phenotype. Various label-retaining techniques have been used to identify normal slow cycling adult stem cell populations and offer a unique methodology to functionally identify and isolate cancer stem cells. The quiescent nature of CSCs represents an inherent mechanism that at least partially explains chemotherapy resistance and recurrence in posttherapy cancer patients. Isolating and understanding the cell cycle regulatory mechanisms of quiescent cancer cells will be a key component to creation of future therapies that better target CSCs and totally eradicate tumors. Here we review the evidence for quiescent CSC populations and explore potential cell cycle regulators that may serve as future targets for elimination of these cells.

scholarly journals Positively Correlated CD47 Activation and Autophagy in Umbilical Cord Blood-Derived Mesenchymal Stem Cells during Senescence

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Gee-Hye Kim ◽  
Yun Kyung Bae ◽  
Ji Hye Kwon ◽  
Miyeon Kim ◽  
Soo Jin Choi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Stem Cell ◽  
Cell Growth ◽  
Cell Therapy ◽  
Critical Role ◽  
Therapeutic Effects ◽  
Stem Cell Maintenance ◽  
Selection Of

Autophagy plays a critical role in stem cell maintenance and is related to cell growth and cellular senescence. It is important to find a quality-control marker for predicting senescent cells. This study verified that CD47 could be a candidate to select efficient mesenchymal stem cells (MSCs) to enhance the therapeutic effects of stem cell therapy by analyzing the antibody surface array. CD47 expression was significantly decreased during the expansion of MSCs in vitro ( p < 0.01 ), with decreased CD47 expression correlated with accelerated senescence phenotype, which affected cell growth. UCB-MSCs transfected with CD47 siRNA significantly triggered the downregulation of pRB and upregulation of pp38, which are senescence-related markers. Additionally, autophagy-related markers, ATG5, ATG12, Beclin1, and LC3B, revealed significant downregulation with CD47 siRNA transfection. Furthermore, autophagy flux following treatment with an autophagy inducer, rapamycin, has shown that CD47 is a key player in autophagy and senescence to maintain and regulate the growth of MSCs, suggesting that CD47 may be a critical key marker for the selection of effective stem cells in cell therapy.

Abstract 239: p53 Protects Cardiac Stem Cells From the Toxic Effects of Chemotherapy and Controls their Fate

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Ramaswamy Kannappan ◽  
Giorgia Palano ◽  
Polina Goichberg ◽  
Fumihiro Sanada ◽  
Sergio Signore ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Dna Damage ◽  
Dna Repair ◽  
Critical Role ◽  
Dna Lesions ◽  
Toxic Effects ◽  
Cardiac Stem Cells ◽  
Inhibition Of Proliferation ◽  
P53 Expression

Doxorubicin (DOXO) causes dilated cardiomyopathy and heart failure. We have documented previously that DOXO-mediated cardiotoxicity is dictated by functional alterations of cardiac stem cells (CSCs). DOXO-induced myopathy was coupled with a reduction in CSC number due to increased death, inhibition of proliferation, and senescence. We raised the possibility that survival and growth of CSCs following DOXO treatment may be enhanced by modulating the intracellular level of p53, which plays a critical role in the determination of stem cell fate. For this purpose, transgenic mice carrying an additional p53 allele (Sp53) were studied. With respect to wild-type mice (WT), CSCs isolated from Sp53 mice (Sp53-CSCs) showed increased apoptosis with accumulation of the pro-apoptotic p53 targets BAX, PUMA and Pidd. Conversely, the expression of p21Cip1, a cell cycle inhibitor and inducer of cell senescence, was lower in Sp53-CSCs than WT cells. Upon DOXO treatment, Sp53-CSCs exhibited accelerated onset of apoptosis. However, viable Sp53-CSCs showed enhanced formation of DNA damage response foci, indicative of a very efficient DNA repair mechanism. Following removal of DOXO, Sp53-CSCs re-entered the cell cycle and divided, while WT cells continued to die by apoptosis or became senescent. The response of WT-CSCs to DOXO involved the pro-apoptotic Bcl2 family member Noxa and the senescence-associated protein p16INK4a. In contrast, exposure of Sp53-CSCs to DOXO provoked pulses of p53 expression, which favored sustained upregulation of Mdm2. Mdm2 antagonized the inhibitory effect of p53 on cell growth and prevented apoptosis. Ultimately, Sp53-CSCs showed accumulation of PCNA, which is required for DNA repair and synthesis. Importantly, IGF-1 release was higher in Sp53-CSCs, promoting their replication through an autocrine-paracrine mechanism. Collectively, our data demonstrate that changes in the pattern of p53 expression have beneficial effects on CSCs by amplifying the DNA repair response, facilitating the clearance of cells with non-repairable DNA damage, and enabling the proliferation of cells in which DNA lesions are effectively removed. Thus, targeting p53 expression in CSCs may protect the heart from the toxic effects of chemotherapy.

scholarly journals Establishing cell-intrinsic limitations in cell cycle progression controls graft growth and promotes differentiation of pancreatic endocrine cells

2020 ◽  
Author(s):  
Lina Sui ◽  
Yurong Xin ◽  
Daniela Georgieva ◽  
Giacomo Diedenhofen ◽  
Leena Haataja ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Stem Cell ◽  
Endocrine Cells ◽  
Cell Cycle Progression ◽  
S Phase ◽  
Growth Potential ◽  
Proliferative Potential ◽  
G1 Arrest ◽  
Cycle Progression

AbstractLimitations in cell proliferation are a key barrier to reprogramming differentiated cells to pluripotent stem cells, and conversely, acquiring these limitations may be important to establish the differentiated state. The pancreas, and beta cells in particular have a low proliferative potential, which limits regeneration, but how these limitations are established is largely unknown. Understanding proliferation potential is important for the safty of cell replacement therapy with cell products made from pluripotent stem cell which have unlimited proliferative potential. Here we test a novel hypothesis, that these limitations are established through limitations in S-phase progression. We used a stem cell-based system to expose differentiating stem cells to small molecules that interfere with cell cycle progression either by inducing G1 arrest, impairing S-phase entry, or S-phase completion. Upon release from these molecules, we determined growth potential, differentiation and function of insulin-producing endocrine cells both in vitro and after grafting in vivo. We found that the combination of G1 arrest with a compromised ability to complete DNA replication promoted the differentiation of pancreatic progenitor cells towards insulin-producing cells, improved the stability of the differentiated state, and protected mice from diabetes without the formation of cystic growths. Therefore, a compromised ability to enter S-phase and replicate the genome is a functionally important property of pancreatic endocrine differentiation, and can be exploited to generate insulin-producing organoids with predictable growth potential after transplantation.

SCL regulates the Quiescence and the Long-Term Competence of Hematopoietic Stem Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2520-2520
Author(s):  
Julie Lacombe ◽  
Sabine Herblot ◽  
Shanti Rojas-Sutterlin ◽  
André Haman ◽  
Stephane Barakat ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Hematopoietic Stem Cells ◽  
Gene Dosage ◽  
Critical Role ◽  
Bhlh Transcription Factor ◽  
Hematopoietic Stem

Abstract Abstract 2520 Poster Board II-497 The life-long production of blood cells depends on the regenerative capacity of a rare bone marrow population, the hematopoietic stem cells (HSCs). In the adult, the majority of HSCs are quiescent while a large proportion of progenitors are more cycling. The state of quiescence in HSCs is reversible and these cells can be triggered into cycle by chemotoxic injuries, exposure to cytokines in vitro, as well as transplantation in vivo. SCL/TAL1 is a bHLH transcription factor that has a critical role in generating HSCs during development. However, the role of SCL in adult HSCs is still a matter of debate. In the present study, we took several approaches to address this question. Scl expression was monitored by quantitative PCR analysis in a population that contains adult long-term reconstituting HSCs (LT-HSCs) at a frequency of 20–50%: Kit+Sca+Lin-CD150+CD48-. RT-PCR results were confirmed by β-galactosidase staining of these cells in Scl-LacZ mice. We show that Scl is highly expressed in LT-HSC and that its expression correlates with quiescence, i.e. Scl levels decrease when LT-HSCs exit the G0 state. In order to assess stem cell function, we performed several transplantation assays with adult bone marrow cells in which SCL protein levels were decreased at least two-fold by gene targeting or by RNA interference. 1) The mean stem cell activity of HSCs transplanted at ∼1 CRU was two-fold decreased in Scl heterozygous (Scl+/−) mice. 2) In competitive transplantation, the contribution of Scl+/− cells to primitive populations as well mature cells in the bone marrow was significantly decreased 8 months after transplantation. 3) In secondary transplantation assays, Scl+/− HSCs were severely impaired in their ability to reconstitute secondary recipient in stem cells and progenitor populations and in almost all mature lineages. 4) Reconstitution of the stem cell pool by adult HSCs expressing Scl-directed shRNAs was significantly decreased compared to controls. We therefore conclude that SCL levels regulate HSC long term competence. Since Scl levels decrease when LT-HSCs exit the G0 state, we addressed the question whether the cell cycle state of LT-HSCs is sensitive to Scl gene dosage. We stained bone marrow cell populations with Hoechst and Pyronin Y. At steady state, percentage LT-HSCs in G1 fraction appears to be significantly increased in mice lacking one allele of Scl. Furthermore, a three-fold increase in G1 fraction was also observed when cells were infected with Scl-directed shRNA, suggesting that a decrease in Scl levels facilitates G0-G1 transition. At the molecular level, we show by chromatin immunoprecipitation that SCL occupies the Cdkn1a and Id1 loci. Furthermore, in purified Kit+Sca+Lin-CD150+CD48- cells, the expression levels of these two regulators of HSC cell cycle and long-term functions are sensitive to Scl gene dosage. Together, our observations suggest that SCL impedes G0-G1 transition in HSCs and regulates their long-term competence. Disclosures: No relevant conflicts of interest to declare.

Genistein Protects Hematopoietic Stem Cells Against G-CSF Induced DNA Damage

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3486-3486
Author(s):  
Liliana Souza ◽  
Erica Silva ◽  
Elissa Calloway ◽  
Michael Rossi ◽  
Omer Kucuk ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Bone Marrow ◽  
Dna Damage ◽  
Stem Cell ◽  
Bone Marrow Cells ◽  
Fold Increase ◽  
Hematopoietic Stem ◽  
Oral Supplementation ◽  
Marrow Cells

Abstract Abstract 3486 Granulocyte colony-stimulating factor (G-CSF) is widely utilized in multiple clinical settings to lessen the effects of neutropenia. Although clearly beneficial, there are concerns about the long term effects of G-CSF. A particular concern is that G-CSF therapy may increase the risk of MDS and or AML. The most striking example is that of Severe Congenital Neutropenia (SCN). While G-CSF clearly improves survival, there are several lines of evidence to suggest that G-CSF treatment contributes to development of leukemia in these patients. First, the risk of leukemia appears to correlate with the cumulative dose of G-CSF. Second, of all the congenital marrow failure syndromes predisposed to AML, SCN alone does not appear to be a hematopoietic stem cell disorder. Since AML appears to rise from sequential mutations in hematopoietic stem cells, this would suggest that therapy, not the intrinsic cell defect is causal. It has been demonstrated that G-CSF does initiate signaling pathways in hematopoietic stem cell (HSC). We hypothesize that G-CSF induced excessive HSC proliferation can lead to DNA damage and genome instability. To test our premise, mice were treated with G-CSF for 4 months and bone marrow cells were analyzed. Our results demonstrated a 3 fold increase in linage negative, Sca positive and cKit positive (LSK) population and a 2 fold increase in the amount of DNA double strand breaks via the presence of nuclear pH2AX in the LSK population. To determine if the G-CSF induced proliferation lead to chromosome alterations, we performed array-comparative genomic hybridization analyses (CGH). DNA from lineage negative bone marrow cells from animals treated with G-CSF for 4 months were compared to untreated mice. Our results demonstrate variations in gains and losses of several chromosome regions. Fluorescence in situ hybridization (FISH) of Lin-Sca+ bone marrow cells confirmed loss on regions of chromosome 2 (6%) and 17 (30%). Since prolonged G-CSF exposure promotes genomic instability in HSCs we hypothesize that an alternative strategy would be to co-administer a drug that selectively blocks the effect of G-CSF on HSCs. Previous studies suggested genistein as an attractive compound. Genistein is a natural soy isoflavone with excellent bioavalibity that has anti-oxidant and anti-proliferative properties. In this study, we utilized a dose of genistein that can easily be obtained through oral supplementation. Mice were concomitant treated with G-CSF and genistein 3 times a week. Genistein partially blocked the G-CSF induced expansion of LSK cells and reduced pH2AX levels in this population by 40%. This was also accompanied by a reduction in LSK cells with an abnormal FISH signal (50% reduction). Importantly, genistein did not block the G-CSF driven expansion of mature neutrophils as total number of neutrophils in mice treated with G-CSF and genistein are the same as those treated with G-CSF alone. Our results suggest that genistein's effects are mediated primarily through inhibition of HSC proliferation. We demonstrate that G-CSF treatment induces GSK3β phosphorylation and Cyclin D1 and D3 expression. Genistein blocked GSK3β phosphorylation and Cyclin D1 and D3 induction. Inhibition of GSKβ3 has been demonstrated to delay HSC entry into cell cycle by promoting degradation of β-catenin, while HSCs from the triple cyclin knock out mouse (Cyclins D1, D2, and D3) display delayed cell cycle entry. Collectively, our results imply that prolonged G-CSF treatment induces DNA damage in HSCs by initiating cell cycle progression. HSCs are long lived, quiescent cells that preferentially utilize non-homologus end joining for DNA repair when progressing from G0 to G1. NHEJ is a relatively error prone DNA repair mechanism. Its preferential use by HSCs has been postulated as reason chromosomal deletions and translocations are often seen and many times are causal in the development of acute leukemia. Importantly, we demonstrate, that genistein, at levels obtainable through oral supplementation, is able to reduce DNA damage by attenuating G-CSF induced HSC proliferation without compromising G-CSFs ability to accelerate terminal neutrophilic differentiation. These results suggest that genistein may be an effective therapeutic agent in patients with SCN who require prolonged G-CSF support. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Ex vivo expansion of murine marrow cells with interleukin-3 (IL-3), IL- 6, IL-11, and stem cell factor leads to impaired engraftment in irradiated hosts

Blood ◽  
1996 ◽  
Vol 87 (1) ◽  
pp. 30-37 ◽  
Author(s):  
SO Peters ◽  
EL Kittler ◽  
HS Ramshaw ◽  
PJ Quesenberry
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Stem Cell ◽  
Stem Cell Factor ◽  
Proliferative Potential ◽  
Interleukin 3 ◽  
Marrow Cells

Abstract In vitro incubation of bone marrow cells with cytokines has been used as an approach to expand stem cells and to facilitate retroviral integration. Expansion of hematopoietic progenitor cells has been monitored by different in vitro assays and in a few instances by in vivo marrow renewal in myeloablated hosts. This is the first report of studies, using two competitive transplant models, in which cytokine-treated cells, obtained from nonpretreated donors (eg, 5-fluorouracil), were competed with normal cells. A basic assumption is that the expansion of progenitors assayed in vitro as high- and low-proliferative potential colony-forming cells (HPP- and LPP-CFCs) indicates an expansion of stem cells which will repopulate in vivo. This study shows that culture of marrow cells with four cytokines (stem cell factor, interleukin-3 [IL-3], IL-6, IL-11) induces significant expansion and proliferation of HPP-CFC and LPP-CFC. Cell-cycle analysis showed that these hematopoietic progenitors were induced to actively cell cycle by culture with these cytokines. In the first competitive transplant model, which uses Ly5.2/Ly5.1 congenic mice, cytokine-cultured Ly5.2 cells competed with noncultured Ly5.1 cells led to 5% +/- 1% engraftment at 12 weeks and to 4% +/- 2% engraftment at 22 weeks posttransplantation for the cytokine exposed cells. Noncultured Ly5.2 cells competed with cultured Ly5.1 cells led to 70% +/- 1% engraftment at 12 weeks and to 93% +/- 2% engraftment at 22 weeks posttransplantation. In the second model, which uses BALB/c marrow of opposite genders, cultured male cells lead to 13% +/- 9% engraftment at 10 weeks and 2% +/- 1% engraftment at 14 weeks posttransplantation; noncultured male cells lead to 70% +/- 2% and 95% +/- 2% engraftment at 10 and 14 weeks posttransplantation, respectively. Data presented here from two different competitive transplant studies show a defect of cytokine expanded marrow related to cell cycle activation which manifests as defective long-term repopulating capability in irradiated host mice. The engraftment defect is more profound at longer time intervals, suggesting that the most striking effect may be on long-term repopulating cells.

Directed Differentiation: Evolution towards Human Application.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4187-4187
Author(s):  
Gerald A. Colvin ◽  
Gerri J. Dooner ◽  
Mark S. Dooner ◽  
Jason Aliotta ◽  
Galatia Politopoulou ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Stem Cell ◽  
Stem Cell Differentiation ◽  
S Phase ◽  
Proliferative Potential ◽  
No Production ◽  
Directed Differentiation ◽  
Initial Cell ◽  
Cd34 Cells

Abstract Directed differentiation is defined as the ability to program a stem cell at the most primitive level while it still has its reproductive and full proliferative potential. This is in contrast to ex-vivo expansion where the stem cells are forced into specific lineage commitments, limiting the overall therapeutic utility. We have reproducibly induced directed stem cell differentiation towards megakaryopoiesis by capitalizing on inherent changes in sensitivities to inductive cytokine signals in the context of cell cycle position. Murine experiments have been performed on highly purified quiescent G0–1 lineagenegative rhodaminelowHoeschtlow (LRH) marrow stem cells. When exposed to thrombopoietin, FLT3-ligand and steel factor (TFS), they synchronously pass through cell cycle. Megakaryopoiesis is focused at early to mid S-phase, returning to baseline before initial cell division. Population based differentiation cultures after 14-days produced up to 49% megakaryocytes with stem cells sub-cultured during early-mid S-phase with little to no production with colonies cultured from stem cells in G0–1 or G2 phase at time directed differentiation signaling. Gene expression showed over 2 fold increases in FOG, Nfe2 and Fli1. Clonal studies confirm the results. In one experiment, 33% of clonally derived colonies that grew from early-S phase cells and 10% of colonies that grew from mid-S phase cells had megakaryocytes present compared with 0% for G0–1 and G2 cells. We have now worked with human lineagenegative double-effluxed-rhodaminelow double-effluxed-Hoeschtlow G0–1 stem cells. When expose to TFS cytokines, there initial cell cycle lasts more than 80 hours opposed to CD34+ cells and murine LRH cells which have divided by 44–48 hours. This human population of stem cells comprises approximately 0.01% of CD34+ cells and has tremendous promise in replicating our murine work, elucidating opportunities for human translational work targeting patients that have a block of differentiation toward megakaryopoiesis i.e. sub-sets of autologous transplant or myelodysplastic syndrome patients.

scholarly journals Ex vivo expansion of murine marrow cells with interleukin-3 (IL-3), IL- 6, IL-11, and stem cell factor leads to impaired engraftment in irradiated hosts

Blood ◽  
1996 ◽  
Vol 87 (1) ◽  
pp. 30-37 ◽  
Author(s):  
SO Peters ◽  
EL Kittler ◽  
HS Ramshaw ◽  
PJ Quesenberry
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Stem Cell ◽  
Stem Cell Factor ◽  
Proliferative Potential ◽  
Interleukin 3 ◽  
Marrow Cells

In vitro incubation of bone marrow cells with cytokines has been used as an approach to expand stem cells and to facilitate retroviral integration. Expansion of hematopoietic progenitor cells has been monitored by different in vitro assays and in a few instances by in vivo marrow renewal in myeloablated hosts. This is the first report of studies, using two competitive transplant models, in which cytokine-treated cells, obtained from nonpretreated donors (eg, 5-fluorouracil), were competed with normal cells. A basic assumption is that the expansion of progenitors assayed in vitro as high- and low-proliferative potential colony-forming cells (HPP- and LPP-CFCs) indicates an expansion of stem cells which will repopulate in vivo. This study shows that culture of marrow cells with four cytokines (stem cell factor, interleukin-3 [IL-3], IL-6, IL-11) induces significant expansion and proliferation of HPP-CFC and LPP-CFC. Cell-cycle analysis showed that these hematopoietic progenitors were induced to actively cell cycle by culture with these cytokines. In the first competitive transplant model, which uses Ly5.2/Ly5.1 congenic mice, cytokine-cultured Ly5.2 cells competed with noncultured Ly5.1 cells led to 5% +/- 1% engraftment at 12 weeks and to 4% +/- 2% engraftment at 22 weeks posttransplantation for the cytokine exposed cells. Noncultured Ly5.2 cells competed with cultured Ly5.1 cells led to 70% +/- 1% engraftment at 12 weeks and to 93% +/- 2% engraftment at 22 weeks posttransplantation. In the second model, which uses BALB/c marrow of opposite genders, cultured male cells lead to 13% +/- 9% engraftment at 10 weeks and 2% +/- 1% engraftment at 14 weeks posttransplantation; noncultured male cells lead to 70% +/- 2% and 95% +/- 2% engraftment at 10 and 14 weeks posttransplantation, respectively. Data presented here from two different competitive transplant studies show a defect of cytokine expanded marrow related to cell cycle activation which manifests as defective long-term repopulating capability in irradiated host mice. The engraftment defect is more profound at longer time intervals, suggesting that the most striking effect may be on long-term repopulating cells.

scholarly journals CCR2 improves homing and engraftment of adipose-derived stem cells in dystrophic mice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Liang Wang ◽  
Huan Li ◽  
Jinfu Lin ◽  
Ruojie He ◽  
Menglong Chen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Motor Function ◽  
Chemokine Receptor ◽  
Critical Role ◽  
Muscle Pathology ◽  
Therapeutic Effects ◽  
Adipose Derived Stem Cells ◽  
Dystrophin Expression ◽  
Dystrophic Mice

Abstract Background Dystrophinopathy, a common neuromuscular disorder caused by the absence of dystrophin, currently lacks effective treatments. Systemic transplantation of adipose-derived stem cells (ADSCs) is a promising treatment approach, but its low efficacy remains a challenge. Chemokine system-mediated stem cell homing plays a critical role in systemic transplantation. Here, we investigated whether overexpression of a specific chemokine receptor could improve muscle homing and therapeutic effects of ADSC systemic transplantation in dystrophic mice. Methods We analysed multiple microarray datasets from the Gene Expression Omnibus to identify a candidate chemokine receptor and then evaluated the protein expression of target ligands in different tissues and organs of dystrophic mice. The candidate chemokine receptor was overexpressed using the lentiviral system in mouse ADSCs, which were used for systemic transplantation into the dystrophic mice, followed by evaluation of motor function, stem cell muscle homing, dystrophin expression, and muscle pathology. Results Chemokine-profile analysis identified C–C chemokine receptor (CCR)2 as the potential target for improving ADSC homing. We found that the levels of its ligands C–C chemokine ligand (CCL)2 and CCL7 were higher in muscles than in other tissues and organs of dystrophic mice. Additionally, CCR2 overexpression improved ADSC migration ability and maintained their multilineage-differentiation potentials. Compared with control ADSCs, transplantation of those overexpressing CCR2 displayed better muscle homing and further improved motor function, dystrophin expression, and muscle pathology in dystrophic mice. Conclusions These results demonstrated that CCR2 improved ADSC muscle homing and therapeutic effects following systemic transplantation in dystrophic mice.

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