Abstract 245: Plasminogen Augments Cxcl12/cxcr4-regulated Stem Cell Homing And Contributes To Cardiac Repair After Myocardial Infarction.

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Yanqing Gong ◽  
Yujing Zhao ◽  
Yi Fan ◽  
Jane Hoover-Plow

Myocardial infarction (MI) is a leading cause of morbidity and mortality worldwide. Bone marrow (BM)-derived stem cells promote tissue repair and regeneration after MI. Thrombolytic treatment with plasminogen (Plg) activators significantly improves the clinical outcome in MI by restoration of cardiac perfusion. In addition to its canonical function, Plg is critical for cardiac repair, wound healing and liver injury, however, the mechanism for Plg-regulated tissue repair remains unclear. Here, we show a novel role of Plg in stem cell-mediated neovascularization and cardiac repair after MI. Our data show that Granulocyte colony-stimulating factor (G-CSF), a stem cell mobilizer, significantly increased neovascularization and decreased infarct size in the infarct area, and improved ejection fraction and LV internal diameter by echocardiogram in wild-type mice. No improvement in tissue repair and heart function was observed in Plg deficient (Plg-/-) mice indicating that Plg is required for stem cell-regulated cardiac repair after MI. In vivo tracking of GFP-expressing BM cells after BM transplantation revealed that in Plg-/- mice, recruitment of BM-derived stem cells (GFP+c-kit+ cells) to the infarcted heart and stem cell-derived vessels and arteries are dramatically decreased (by 11 fold) suggesting that Plg may regulate stem cell homing to the lesion sites and subsequently contribute stem cell-mediated tissue regeneration. Mechanistic studies show that Plg up-regulated CXCR4 expression on stem cell in vivo and in vitro, suggesting Plg may promotes stem cell homing by induction of CXCR4 expression in stem cells. Stem cell migration was enhanced by endogenous Plg in vitro, however, AMD3100, a CXCR4 antagonist, significantly inhibited Plg-regulated stem cell migration. Furthermore, lentiviral reconstitution of CXCR4 expression in BM cells rescued stem cell homing to the infarcted heart in Plg-/- mice, indicating that Plg mediates stem cell homing through regulating CXCR4 expression. These findings identified a novel role of Plg in cardiac repair by promoting stem cell homing to the injured heart after MI. Thus, targeting Plg may offer a new therapeutic strategy for strengthening stem cell-mediated cardiac repair and regeneration after MI.

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Lu Li ◽  
Shengzheng Wu ◽  
Zheng Liu ◽  
Zhongxiong Zhuo ◽  
Kaibin Tan ◽  
...  

Mesenchymal stem cell (MSC) therapy shows considerable promise for the treatment of myocardial infarction (MI). However, the inefficient migration and homing of MSCs after systemic infusion have limited their therapeutic applications. Ultrasound-targeted microbubble destruction (UTMD) has proven to be promising to improve the homing of MSCs to the ischemic myocardium, but the concrete mechanism remains unclear. We hypothesize that UTMD promotes MSC homing by upregulating SDF-1/CXCR4, and this study was aimed at exploring this potential mechanism. We analyzed SDF-1/CXCR4 expression after UTMD treatment in vitro and in vivo and counted the number of homing MSCs in MI areas. The in vitro results demonstrated that UTMD not only led to elevated secretion of SDF-1 but also resulted in an increased proportion of MSCs that expressed surface CXCR4. The in vivo findings show an increase in the number of homing MSCs and higher expression of SDF-1/CXCR4 in the UTMD combined with MSCs infusion group compared to other groups. In conclusion, UTMD can increase SDF-1 expression in the ischemic myocardium and upregulate the expression of surface CXCR4 on MSCs, which provides a molecular mechanism for the homing of MSCs assisted by UTMD via SDF-1/CXCR4 axis.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Santhosh Kumar Ghadge ◽  
Thi Van Pham ◽  
Moritz Messner ◽  
Maximilian Doppelhammer ◽  
Britta Husse ◽  
...  

Objective: Stabilization of the cardiac SDF-1/CXCR4 axis attenuates ischemic cardiomyopathy. However, HIF-1α dependent SDF-1 upregulation lasts only for 48-72 hours after myocardial infarction (MI) limiting the targeting of regenerative cells. Therefore, we hypothesized that activation of the HIF-1α target genes SDF-1 and CXCR4 by stabilization of HIF-1α through inhibition of prolyl hydroxylase stimulates myocardial repair. Methods: Genetically tagged SDF1-EGFP and CXCR4-EGFP mice were subjected to optimal doses (80mg/kg i.p.) of the prolyl hydroxylase Inhibitor dimethyloxalylglycine (DMOG). To examine the time frame of SDF-1 and CXCR4 expression in vitro (HEK cells) and in vivo (BM & heart), DMOG was treated at different dosing regimens (50μM to 1000μM & 80mg/kg i.p.) and time intervals (1 to 6 hrs). FACS and immunhistochemical analyses of CXCR4+ BM, peripheral blood, and heart cells as well as infarct size measurements and hemodynamic analyses were performed with and without DMOG treatment after MI. Results: SDF1-EGFP mice treated with DMOG showed robust induction of SDF-1 in heart vessels. In vitro , SDF-1 was transiently upregulated within 60 mins to 2 hrs after DMOG treatment, followed by significant decrease after 6hrs. CXCR4 was elevated at later time points (6h). In vivo , CXCR4 expression was significantly upregualted in BM (6h). FACS analyses of transgenic CXCR4-EGFP BM and hearts revealed that CXCR4+ was frequently expressed on CD11b+ monocytes, and at lower Levels on angiogenic CD31+ , CD34+, c-kit+, and Flk1+ cells, and stem cell populations like CD133+ and Lin-/c-kit+/Sca-1+. DMOG treatment after MI revealed a robust upregulation of CXCR4+ cell populations, predominantly of angiogenic CXCR4+/CD11b+ monocytes. Subanalysis of the latter showed that DMOG treatment leads to a shift of the CD206+/CD86 ratio in favor of M2 macrophages associated CD206+ subpopulation after MI associated by attenuated infarct remodeling. Myocardial function was significantly improved after DMOG treatment (EF: 33,5 vs. 16%). Conclusion: Our data suggest that inhibition of prolyl hydroxylase may be a promising target for HIF-1a mediated SDF-1 activation to increase CXCR4+ stem cell homing and myocardial repair.


Life Sciences ◽  
2021 ◽  
pp. 119728
Author(s):  
Fatemeh Dehghani Nazhvani ◽  
Leila Mohammadi Amirabad ◽  
Arezo Azari ◽  
Hamid Namazi ◽  
Simzar Hosseinzadeh ◽  
...  

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Manuel Pedro Jimenez-García ◽  
Antonio Lucena-Cacace ◽  
Daniel Otero-Albiol ◽  
Amancio Carnero

AbstractThe EMX (Empty Spiracles Homeobox) genes EMX1 and EMX2 are two homeodomain gene members of the EMX family of transcription factors involved in the regulation of various biological processes, such as cell proliferation, migration, and differentiation, during brain development and neural crest migration. They play a role in the specification of positional identity, the proliferation of neural stem cells, and the differentiation of certain neuronal cell phenotypes. In general, they act as transcription factors in early embryogenesis and neuroembryogenesis from metazoans to higher vertebrates. The EMX1 and EMX2’s potential as tumor suppressor genes has been suggested in some cancers. Our work showed that EMX1/EMX2 act as tumor suppressors in sarcomas by repressing the activity of stem cell regulatory genes (OCT4, SOX2, KLF4, MYC, NANOG, NES, and PROM1). EMX protein downregulation, therefore, induced the malignance and stemness of cells both in vitro and in vivo. In murine knockout (KO) models lacking Emx genes, 3MC-induced sarcomas were more aggressive and infiltrative, had a greater capacity for tumor self-renewal, and had higher stem cell gene expression and nestin expression than those in wild-type models. These results showing that EMX genes acted as stemness regulators were reproduced in different subtypes of sarcoma. Therefore, it is possible that the EMX genes could have a generalized behavior regulating proliferation of neural crest-derived progenitors. Together, these results indicate that the EMX1 and EMX2 genes negatively regulate these tumor-altering populations or cancer stem cells, acting as tumor suppressors in sarcoma.


2021 ◽  
Vol 22 (4) ◽  
pp. 1824
Author(s):  
Matthias Mietsch ◽  
Rabea Hinkel

With cardiovascular diseases affecting millions of patients, new treatment strategies are urgently needed. The use of stem cell based approaches has been investigated during the last decades and promising effects have been achieved. However, the beneficial effect of stem cells has been found to being partly due to paracrine functions by alterations of their microenvironment and so an interesting field of research, the “stem- less” approaches has emerged over the last years using or altering the microenvironment, for example, via deletion of senescent cells, application of micro RNAs or by modifying the cellular energy metabolism via targeting mitochondria. Using autologous muscle-derived mitochondria for transplantations into the affected tissues has resulted in promising reports of improvements of cardiac functions in vitro and in vivo. However, since the targeted treatment group represents mainly elderly or otherwise sick patients, it is unclear whether and to what extent autologous mitochondria would exert their beneficial effects in these cases. Stem cells might represent better sources for mitochondria and could enhance the effect of mitochondrial transplantations. Therefore in this review we aim to provide an overview on aging effects of stem cells and mitochondria which might be important for mitochondrial transplantation and to give an overview on the current state in this field together with considerations worthwhile for further investigations.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Mohammed Zayed ◽  
Steven Newby ◽  
Nabil Misk ◽  
Robert Donnell ◽  
Madhu Dhar

Horses are widely used as large animal preclinical models for cartilage repair studies, and hence, there is an interest in using equine synovial fluid-derived mesenchymal stem cells (SFMSCs) in research and clinical applications. Since, we have previously reported that similar to bone marrow-derived MSCs (BMMSCs), SFMSCs may also exhibit donor-to-donor variations in their stem cell properties; the current study was carried out as a proof-of-concept study, to compare the in vivo potential of equine BMMSCs and SFMSCs in articular cartilage repair. MSCs from these two sources were isolated from the same equine donor. In vitro analyses confirmed a significant increase in COMP expression in SFMSCs at day 14. The cells were then encapsulated in neutral agarose scaffold constructs and were implanted into two mm diameter full-thickness articular cartilage defect in trochlear grooves of the rat femur. MSCs were fluorescently labeled, and one week after treatment, the knee joints were evaluated for the presence of MSCs to the injured site and at 12 weeks were evaluated macroscopically, histologically, and then by immunofluorescence for healing of the defect. The macroscopic and histological evaluations showed better healing of the articular cartilage in the MSCs’ treated knee than in the control. Interestingly, SFMSC-treated knees showed a significantly higher Col II expression, suggesting the presence of hyaline cartilage in the healed defect. Data suggests that equine SFMSCs may be a viable option for treating osteochondral defects; however, their stem cell properties require prior testing before application.


2021 ◽  
pp. 002215542110262
Author(s):  
Ethan J. Kilmister ◽  
Swee T. Tan

Cancer stem cells (CSCs) drive metastasis, treatment resistance, and tumor recurrence. CSCs reside within a niche, an anatomically distinct site within the tumor microenvironment (TME) that consists of malignant and non-malignant cells, including immune cells. The renin–angiotensin system (RAS), a critical regulator of stem cells and key developmental processes, plays a vital role in the TME. Non-malignant cells within the CSC niche and stem cell signaling pathways such as the Wnt, Hedgehog, and Notch pathways influence CSCs. Components of the RAS and cathepsins B and D that constitute bypass loops of the RAS are expressed on CSCs in many cancer types. There is extensive in vitro and in vivo evidence showing that RAS inhibition reduces tumor growth, cell proliferation, invasion, and metastasis. However, there is inconsistent epidemiological data on the effect of RAS inhibitors on cancer incidence and survival outcomes, attributed to different patient characteristics and methodologies used between studies. Further mechanistic studies are warranted to investigate the precise effects of the RAS on CSCs directly and/or the CSC niche. Targeting the RAS, its bypass loops, and convergent signaling pathways participating in the TME and other key stem cell pathways that regulate CSCs may be a novel approach to cancer treatment:


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.


2020 ◽  
pp. 019262332091824
Author(s):  
Richard Haworth ◽  
Michaela Sharpe

In 2011, Goldring and colleagues published a review article describing the potential safety issues of novel stem cell-derived treatments. Immunogenicity and immunotoxicity of the administered cell product were considered risks in the light of clinical experience of transplantation. The relative immunogenicity of mesenchymal stem cells, embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs) was being addressed through in vitro and in vivo models. But the question arose as to whether the implanted cells needed to be identical to the recipient in every respect, including epigenetically, to evade immune recognition? If so, this set a high bar which may preclude use of many cells derived from iPSCs which have vestiges of a fetal phenotype and epigenetic memory of their cell of origin. However, for autologous iPSCs, the immunogenicity reduces once the surface antigen expression profile becomes close to that of the parent somatic cells. Therefore, a cell product containing incompletely differentiated cells could be more immunogenic. The properties of the administered cells, the immune privilege of the administration site, and the host immune status influence graft success or failure. In addition, the various approaches available to characterize potential immunogenicity of a cell therapy will be discussed.


2019 ◽  
Vol 15 (11) ◽  
pp. 2179-2192
Author(s):  
Yuanyuan Xie ◽  
Wei Liu ◽  
Bing Zhang ◽  
Bin Wang ◽  
Liudi Wang ◽  
...  

Until now, there is no effective method for tracking transplanted stem cells in human. Ruicun (RC) is a new ultra-small SPIONs agent that has been approved by China Food and Drug Administration for iron supplementation but not as a stem cell tracer in clinic. In this study, we demonstrated magnetic resonance imaging-based tracking of RC-labeled human umbilical cord derived mesenchymal stem cells (MSCs) transplanted to locally injured site of rat spinal cords. We then comprehensively evaluated the safety and quality of the RC-labeled MSCs under good manufacturing practicecompliant conditions, to investigate the feasibility of SPIONs for inner tracking in stem cell-based therapy (SCT). Our results showed that RC labeling at appropriate dose (200 μg/mL) did not have evident impacts on characteristics of MSCs in vitro, demonstrating safety, non-carcinogenesis, and non-tissue inflammation in vivo. The systematic assessments of intracellular biocompatibility indicated that the RC labeled MSCs met with mandatory requirements and standards for law-regulation systems regarding SCT, facilitating translation of cell-tracking technologies to clinical trials.


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