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Sample records for cell repair therapy

  1. Brain repair: cell therapy in stroke

    PubMed Central

    Kalladka, Dheeraj; Muir, Keith W

    2014-01-01

    Stroke affects one in every six people worldwide, and is the leading cause of adult disability. Some spontaneous recovery is usual but of limited extent, and the mechanisms of late recovery are not completely understood. Endogenous neurogenesis in humans is thought to contribute to repair, but its extent is unknown. Exogenous cell therapy is promising as a means of augmenting brain repair, with evidence in animal stroke models of cell migration, survival, and differentiation, enhanced endogenous angiogenesis and neurogenesis, immunomodulation, and the secretion of trophic factors by stem cells from a variety of sources, but the potential mechanisms of action are incompletely understood. In the animal models of stroke, both mesenchymal stem cells (MSCs) and neural stem cells (NSCs) improve functional recovery, and MSCs reduce the infarct volume when administered acutely, but the heterogeneity in the choice of assessment scales, publication bias, and the possible confounding effects of immunosuppressants make the comparison of effects across cell types difficult. The use of adult-derived cells avoids the ethical issues around embryonic cells but may have more restricted differentiation potential. The use of autologous cells avoids rejection risk, but the sources are restricted, and culture expansion may be necessary, delaying treatment. Allogeneic cells offer controlled cell numbers and immediate availability, which may have advantages for acute treatment. Early clinical trials of both NSCs and MSCs are ongoing, and clinical safety data are emerging from limited numbers of selected patients. Ongoing research to identify prognostic imaging markers may help to improve patient selection, and the novel imaging techniques may identify biomarkers of recovery and the mechanism of action for cell therapies. PMID:24627643

  2. Cardiac Repair and Regeneration: The Value of Cell Therapies.

    PubMed

    Lerman, Daniel Alejandro; Alotti, Nasri; Ume, Kiddy Levente; Péault, Bruno

    2016-01-01

    Ischaemic heart disease is the predominant contributor to cardiovascular morbidity and mortality; one million myocardial Infarctions occur per year in the USA, while more than five million patients suffer from chronic heart failure. Recently, heart failure has been singled out as an epidemic and is a staggering clinical and public health problem associated with significant mortality, morbidity and healthcare expenditures, particularly among those aged ≥65 years. Death rates have improved dramatically over the last four decades, but new approaches are nevertheless urgently needed for those patients who go on to develop ventricular dysfunction and chronic heart failure. Over the past decade, stem cell transplantation has emerged as a promising therapeutic strategy for acute or chronic ischaemic cardiomyopathy. Multiple candidate cell types have been used in preclinical animal models and in humans to repair or regenerate the injured heart, either directly or indirectly (through paracrine effects), including: embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), neonatal cardiomyocytes, skeletal myoblasts (SKMs), endothelial progenitor cells, bone marrow mononuclear cells (BMMNCs), mesenchymal stem cells (MSCs) and, most recently, cardiac stem cells (CSCs). Although no consensus has emerged yet, the ideal cell type for the treatment of heart disease should: (a) improve heart function; (b) create healthy and functional cardiac muscle and vasculature, integrated into the host tissue; (c) be amenable to delivery by minimally invasive clinical methods; (d) be available 'off the shelf' as a standardised reagent; (e) be tolerated by the immune system; (f) be safe oncologically, i.e. not create tumours; and (g) circumvent societal ethical concerns. At present, it is not clear whether such a 'perfect' stem cell exists; what is apparent, however, is that some cell types are more promising than others. In this brief review, we provide ongoing data on agreement

  3. Cell-replacement therapy and neural repair in the retina.

    PubMed

    Schmeer, Christian W; Wohl, Stefanie G; Isenmann, Stefan

    2012-07-01

    Visual impairment severely affects the quality of life of patients and their families and is also associated with a deep economic impact. The most common pathologies responsible for visual impairment and legally defined blindness in developed countries include age-related macular degeneration, glaucoma and diabetic retinopathy. These conditions share common pathophysiological features: dysfunction and loss of retinal neurons. To date, two main approaches are being taken to develop putative therapeutic strategies: neuroprotection and cell replacement. Cell replacement is a novel therapeutic approach to restore visual capabilities to the degenerated adult neural retina and represents an emerging field of regenerative neurotherapy. The discovery of a population of proliferative cells in the mammalian retina has raised the possibility of harnessing endogenous retinal stem cells to elicit retinal repair. Furthermore, the development of suitable protocols for the reprogramming of differentiated somatic cells to a pluripotent state further increases the therapeutic potential of stem-cell-based technologies for the treatment of major retinal diseases. Stem-cell transplantation in animal models has been most effectively used for the replacement of photoreceptors, although this therapeutic approach is also being used for inner retinal pathologies. In this review, we discuss recent advances in the development of cell-replacement approaches for the treatment of currently incurable degenerative retinal diseases.

  4. Trophic factors and cell therapy to stimulate brain repair after ischaemic stroke

    PubMed Central

    Gutiérrez-Fernández, María; Fuentes, Blanca; Rodríguez-Frutos, Berta; Ramos-Cejudo, Jaime; Vallejo-Cremades, María Teresa; Díez-Tejedor, Exuperio

    2012-01-01

    Brain repair involves a compendium of natural mechanisms that are activated following stroke. From a therapeutic viewpoint, reparative therapies that encourage cerebral plasticity are needed. In the last years, it has been demonstrated that modulatory treatments for brain repair such as trophic factor- and stem cell-based therapies can promote neurogenesis, gliogenesis, oligodendrogenesis, synaptogenesis and angiogenesis, all of which having a beneficial impact on infarct volume, cell death and, finally, and most importantly, on the functional recovery. However, even when promising results have been obtained in a wide range of experimental animal models and conditions these preliminary results have not yet demonstrated their clinical efficacy. Here, we focus on brain repair modulatory treatments for ischaemic stroke, that use trophic factors, drugs with trophic effects and stem cell therapy. Important and still unanswered questions for translational research ranging from experimental animal models to recent and ongoing clinical trials are reviewed here. PMID:22452968

  5. Immunopharmacological intervention for successful neural stem cell therapy: New perspectives in CNS neurogenesis and repair.

    PubMed

    Dooley, Dearbhaile; Vidal, Pia; Hendrix, Sven

    2014-01-01

    The pharmacological support and stimulation of endogenous and transplanted neural stem cells (NSCs) is a major challenge in brain repair. Trauma to the central nervous system (CNS) results in a distinct inflammatory response caused by local and infiltrating immune cells. This makes NSC-supported regeneration difficult due to the presence of inhibitory immune factors which are upregulated around the lesion site. The continual and dual role of the neuroinflammatory response leaves it difficult to decipher upon a single modulatory strategy. Therefore, understanding the influence of cytokines upon regulation of NSC self-renewal, proliferation and differentiation is crucial when designing therapies for CNS repair. There is a plethora of partially conflicting data in vitro and in vivo on the role of cytokines in modulating the stem cell niche and the milieu around NSC transplants. This is mainly due to the pleiotropic role of many factors. In order for cell-based therapy to thrive, treatment must be phase-specific to the injury and also be personalized for each patient, i.e. taking age, sex, neuroimmune and endocrine status as well as other key parameters into consideration. In this review, we will summarize the most relevant information concerning interleukin (IL)-1, IL-4, IL-10, IL-15, IFN-γ, the neuropoietic cytokine family and TNF-α in order to extract promising therapeutic approaches for further research. We will focus on the consequences of neuroinflammation on endogenous brain stem cells and the transplantation environment, the effects of the above cytokines on NSCs, as well as immunopharmacological manipulation of the microenvironment for potential therapeutic use.

  6. Preclinical Studies on Mesenchymal Stem Cell-Based Therapy for Growth Plate Cartilage Injury Repair

    PubMed Central

    Chung, Rosa; Foster, Bruce K.; Xian, Cory J.

    2011-01-01

    In the last two decades, there has been a strong interest in searching for biological treatments for regeneration of injured growth plate cartilage and prevention of its bony repair. Various means have been tried, including implantation of chondrocytes, mesenchymal stem cell (MSC), together with exogenous growth factor and scaffolds, and gene therapy. However, with the lack of success with chondrocytes, more research has focussed on MSC-based treatments. In addition to circumvent limitations with MSC-based treatments (including cell harvest-associated morbidity, difficulties/time/cost involved in MSC isolation and ex vivo expansion, and potential disease transmission), mobilising endogenous MSCs to the growth plate injury site and enhancing in situ regeneration mechanisms would represent an alternative attractive approach. Further studies are required to investigate the potential particularly in large animal models or clinical setting of the ex vivo MSC approach and the feasibility of the endogenous MSC in situ approach in growth plate regeneration. PMID:21808649

  7. Concise Review: Dental Pulp Stem Cells: A Novel Cell Therapy for Retinal and Central Nervous System Repair.

    PubMed

    Mead, Ben; Logan, Ann; Berry, Martin; Leadbeater, Wendy; Scheven, Ben A

    2017-01-01

    Dental pulp stem cells (DPSC) are neural crest-derived ecto-mesenchymal stem cells that can relatively easily and non-invasively be isolated from the dental pulp of extracted postnatal and adult teeth. Accumulating evidence suggests that DPSC have great promise as a cellular therapy for central nervous system (CNS) and retinal injury and disease. The mode of action by which DPSC confer therapeutic benefit may comprise multiple pathways, in particular, paracrine-mediated processes which involve a wide array of secreted trophic factors and is increasingly regarded as the principal predominant mechanism. In this concise review, we present the current evidence for the use of DPSC to repair CNS damage, including recent findings on retinal ganglion cell neuroprotection and regeneration in optic nerve injury and glaucoma. Stem Cells 2017;35:61-67.

  8. Enhanced potency of cell-based therapy for ischemic tissue repair using an injectable bioactive epitope presenting nanofiber support matrix.

    PubMed

    Tongers, Jörn; Webber, Matthew J; Vaughan, Erin E; Sleep, Eduard; Renault, Marie-Ange; Roncalli, Jerome G; Klyachko, Ekaterina; Thorne, Tina; Yu, Yang; Marquardt, Katja-Theres; Kamide, Christine E; Ito, Aiko; Misener, Sol; Millay, Meredith; Liu, Ting; Jujo, Kentaro; Qin, Gangjian; Losordo, Douglas W; Stupp, Samuel I; Kishore, Raj

    2014-09-01

    The translation of cell-based therapies for ischemic tissue repair remains limited by several factors, including poor cell survival and limited target site retention. Advances in nanotechnology enable the development of specifically designed delivery matrices to address these limitations and thereby improve the efficacy of cell-based therapies. Given the relevance of integrin signaling for cellular homeostasis, we developed an injectable, bioactive peptide-based nanofiber matrix that presents an integrin-binding epitope derived from fibronectin, and evaluated its feasibility as a supportive artificial matrix for bone marrow-derived pro-angiogenic cells (BMPACs) used as a therapy in ischemic tissue repair. Incubation of BMPACs with these peptide nanofibers in vitro significantly attenuated apoptosis while enhancing proliferation and adhesion. Pro-angiogenic function was enhanced, as cells readily formed tubes. These effects were, in part, mediated via p38, and p44/p42 MAP kinases, which are downstream pathways of focal adhesion kinase. In a murine model of hind limb ischemia, an intramuscular injection of BMPACs within this bioactive peptide nanofiber matrix resulted in greater retention of cells, enhanced capillary density, increased limb perfusion, reduced necrosis/amputation, and preserved function of the ischemic limb compared to treatment with cells alone. This self-assembling, bioactive peptide nanofiber matrix presenting an integrin-binding domain of fibronectin improves regenerative efficacy of cell-based strategies in ischemic tissue by enhancing cell survival, retention, and reparative functions.

  9. Stem cells in cardiovascular regeneration: from preservation of endogenous repair to future cardiovascular therapies.

    PubMed

    Templin, Christian; Kränkel, Nicolle; Lüscher, Thomas F; Landmesser, Ulf

    2011-10-01

    Cardiovascular disease remains the leading cause of morbidity and mortality in the developed countries. This review summarizes current pre-clinical and clinical evidence for the potential role and mechanisms of action of stem and progenitor cells in vascular and cardiac repair and regeneration. Apart from cell transplantation strategies, approaches to maintain stem cell niche function and targeting mobilization/recruitment of specific stem/progenitor cell populations may aid in preserving vascular and cardiac function. Moreover, with the use of patient-derived induced pluripotent stem cells, the field of regenerative medicine is entering a new era. Potential applications of induced pluripotent stem cells and direct reprogrammed cells as well as recent developments in tissue engineering are discussed.

  10. Dual differentiation-exogenous mesenchymal stem cell therapy for traumatic spinal cord injury repair in a murine hemisection model.

    PubMed

    Liu, Hai; Schwarz, Edward M; Xie, Chao

    2013-01-01

    Mesenchymal stem cell (MSC) transplantation has shown tremendous promise as a therapy for repair of various tissues of the musculoskeletal, vascular, and central nervous systems. Based on this success, recent research in this field has focused on complex tissue damage, such as that which occurs from traumatic spinal cord injury (TSCI). As the critical event for successful exogenous, MSC therapy is their migration to the injury site, which allows for their anti-inflammatory and morphogenic effects on fracture healing, neuronal regeneration, and functional recover. Thus, there is a need for a cost-effective in vivo model that can faithfully recapitulate the salient features of the injury, therapy, and recovery. To address this, we review the recent advances in exogenous MSC therapy for TSCI and traumatic vertebral fracture repair and the existing challenges regarding their translational applications. We also describe a novel murine model designed to take advantage of multidisciplinary collaborations between musculoskeletal and neuroscience researchers, which is needed to establish an efficacious MSC therapy for TSCI.

  11. Experimental therapies for repair of the central nervous system: stem cells and tissue engineering.

    PubMed

    Forraz, N; Wright, K E; Jurga, M; McGuckin, C P

    2013-07-01

    Several stem cell-based therapeutic tools are currently being investigated for the regeneration of central nervous system (CNS) injuries. This review focuses on innovative approaches for CNS tissue repair via the use of implantable cellular devices. These devices are supported by biopharmaceuticals and conventional physiotherapy for the restoration of lost neuronal circuits and CNS function. This paper further reviews new and promising tools currently in pre-clinical and clinical tests for the treatment of CNS diseases where substantial loss of cellular and extracellular components of neural tissue has occurred such as stroke, encephalopathy and traumatic neural injuries. We also discuss selected 3D bioscaffolds co-cultured with clinically applicable human mesenchymal stem cells. Recent advances in neural tissue engineering and stem cell differentiation methods have shown promise for their clinical application in treating yet incurable CNS deficits.

  12. Vascular Repair by Circumferential Cell Therapy Using Magnetic Nanoparticles and Tailored Magnets.

    PubMed

    Vosen, Sarah; Rieck, Sarah; Heidsieck, Alexandra; Mykhaylyk, Olga; Zimmermann, Katrin; Bloch, Wilhelm; Eberbeck, Dietmar; Plank, Christian; Gleich, Bernhard; Pfeifer, Alexander; Fleischmann, Bernd K; Wenzel, Daniela

    2016-01-26

    Cardiovascular disease is often caused by endothelial cell (EC) dysfunction and atherosclerotic plaque formation at predilection sites. Also surgical procedures of plaque removal cause irreversible damage to the EC layer, inducing impairment of vascular function and restenosis. In the current study we have examined a potentially curative approach by radially symmetric re-endothelialization of vessels after their mechanical denudation. For this purpose a combination of nanotechnology with gene and cell therapy was applied to site-specifically re-endothelialize and restore vascular function. We have used complexes of lentiviral vectors and magnetic nanoparticles (MNPs) to overexpress the vasoprotective gene endothelial nitric oxide synthase (eNOS) in ECs. The MNP-loaded and eNOS-overexpressing cells were magnetic, and by magnetic fields they could be positioned at the vascular wall in a radially symmetric fashion even under flow conditions. We demonstrate that the treated vessels displayed enhanced eNOS expression and activity. Moreover, isometric force measurements revealed that EC replacement with eNOS-overexpressing cells restored endothelial function after vascular injury in eNOS(-/-) mice ex and in vivo. Thus, the combination of MNP-based gene and cell therapy with custom-made magnetic fields enables circumferential re-endothelialization of vessels and improvement of vascular function.

  13. Single cell wound repair

    PubMed Central

    Abreu-Blanco, Maria Teresa; Verboon, Jeffrey M

    2011-01-01

    Cell wounding is a common event in the life of many cell types, and the capacity of the cell to repair day-to-day wear-and-tear injuries, as well as traumatic ones, is fundamental for maintaining tissue integrity. Cell wounding is most frequent in tissues exposed to high levels of stress. Survival of such plasma membrane disruptions requires rapid resealing to prevent the loss of cytosolic components, to block Ca2+ influx and to avoid cell death. In addition to patching the torn membrane, plasma membrane and cortical cytoskeleton remodeling are required to restore cell function. Although a general understanding of the cell wound repair process is in place, the underlying mechanisms of each step of this response are not yet known. We have developed a model to study single cell wound repair using the early Drosophila embryo. Our system combines genetics and live imaging tools, allowing us to dissect in vivo the dynamics of the single cell wound response. We have shown that cell wound repair in Drosophila requires the coordinated activities of plasma membrane and cytoskeleton components. Furthermore, we identified an unexpected role for E-cadherin as a link between the contractile actomyosin ring and the newly formed plasma membrane plug. PMID:21922041

  14. Developing Animal Models for Optimizing the Musculoskeletal Repair Potential of Emerging Human Progenitor Cell Therapies

    DTIC Science & Technology

    2014-06-01

    anterior bowing), posterior-anterior (for lateral displacement) and axial (knee to foot , for rotational displacement. Specific rules for measuring the...dependent on the degree for fixation. •Begin a program of impaired fracture healing caused by diabetes mellitus or cigarette smoking to determine which...The proposal will examine the model in murine backgrounds with impaired skeletal repair such as diabetes , glucocorticoid excess and smoking to

  15. Can the response to a platinum-based therapy be predicted by the DNA repair status in non-small cell lung cancer?

    PubMed

    Macerelli, Marianna; Ganzinelli, Monica; Gouedard, Cedric; Broggini, Massimo; Garassino, Marina Chiara; Linardou, Helena; Damia, Giovanna; Wiesmüller, Lisa

    2016-07-01

    Preclinical evidence has been accumulating on the impact of the DNA repair status on the sensitivity/resistance to anticancer agents in different tumor types, including lung cancer. The possibility to predict the response to therapy, and specifically to platinum agents, based on tumor specific DNA repair functionality would enable to tailor its use only in those patients with maximum chances to respond, avoiding the burden of toxicity in those ones with lesser chances. We here reviewed the clinical evidence on the prognostic role of DNA repair markers and/or functional assays in predicting the response to a platinum-based chemotherapy in lung cancer patients. Consequently, we focused on those proteins involved in pathways repairing platinum induced DNA inter-strand and intra-strand crosslinks. Most promising clinical trials targeting the nucleotide repair protein ERCC1 in non-small cell lung cancer later on suffered from serious drawbacks. Nevertheless, these results spurred a variety of preclinical studies on a multitude of alternative DNA repair markers. However so far, no one of the analyzed DNA repair markers can be considered a reliable and mature biomarker for selecting patients. We discuss the reasons for such failure which discloses novel strategies for the future.

  16. Cell and gene therapy.

    PubMed

    Rao, Rajesh C; Zacks, David N

    2014-01-01

    Replacement or repair of a dysfunctional gene combined with promoting cell survival is a two-pronged approach that addresses an unmet need in the therapy of retinal degenerative diseases. In this chapter, we discuss various strategies toward achieving both goals: transplantation of wild-type cells to replace degenerating cells and to rescue gene function, sequential gene and cell therapy, and in vivo reprogramming of rods to cones. These approaches highlight cutting-edge advances in cell and gene therapy, and cellular lineage conversion in order to devise new therapies for various retinal degenerative diseases.

  17. DNA repair mechanisms in cancer development and therapy

    PubMed Central

    Torgovnick, Alessandro; Schumacher, Björn

    2015-01-01

    DNA damage has been long recognized as causal factor for cancer development. When erroneous DNA repair leads to mutations or chromosomal aberrations affecting oncogenes and tumor suppressor genes, cells undergo malignant transformation resulting in cancerous growth. Genetic defects can predispose to cancer: mutations in distinct DNA repair systems elevate the susceptibility to various cancer types. However, DNA damage not only comprises a root cause for cancer development but also continues to provide an important avenue for chemo- and radiotherapy. Since the beginning of cancer therapy, genotoxic agents that trigger DNA damage checkpoints have been applied to halt the growth and trigger the apoptotic demise of cancer cells. We provide an overview about the involvement of DNA repair systems in cancer prevention and the classes of genotoxins that are commonly used for the treatment of cancer. A better understanding of the roles and interactions of the highly complex DNA repair machineries will lead to important improvements in cancer therapy. PMID:25954303

  18. DNA Repair and Personalized Breast Cancer Therapy

    PubMed Central

    Li, Shu-Xia; Sjolund, Ashley; Harris, Lyndsay; Sweasy, Joann B.

    2010-01-01

    Personalized cancer therapy is likely to be one of the next big advances in our search for a cure for cancer. To be able to treat people in an individualized manner, researchers need to know a great deal about their genetic constitution and the DNA repair status of their tumors. Specific knowledge is required regarding the polymorphisms individuals carry and how these polymorphisms influence responses to therapy. Researchers are actively engaged in biomarker discovery and validation for this purpose. In addition, the design of clinical trials must be reassessed to include new information on biomarkers and drug responses. In this review, we focus on personalized breast cancer therapy. The hypothesis we focus upon in this review is that there is connection between the DNA repair profile of individuals, their breast tumor subtypes, and their responses to cancer therapy. We first briefly review cellular DNA repair pathways that are likely to be impacted by breast cancer therapies. Next, we review the phenotypes of breast tumor subtypes with an emphasis on how a DNA repair deficiency might result in tumorigenesis itself and lead to the chemotherapeutic responses that are observed. Specific examples of breast tumor subtypes and their responses to cancer therapy are given, and we discuss possible DNA repair mechanisms that underlie the responses of tumors to various chemotherapeutic agents. Much is known about breast cancer subtypes and the way each of these subtypes responds to chemotherapy. In addition, we discuss novel design of clinical trials that incorporates rapidly emerging information on biomarkers. PMID:20872853

  19. Exploiting DNA repair defects for novel cancer therapies

    PubMed Central

    van Gent, Dik C.; Kanaar, Roland

    2016-01-01

    Most human tumors accumulate a multitude of genetic changes due to defects in the DNA damage response. Recently, small-molecule inhibitors have been developed that target cells with specific DNA repair defects, providing hope for precision treatment of such tumors. Here we discuss the rationale behind these therapies and how an important bottleneck—patient selection—can be approached. PMID:27418635

  20. Bone repair and stem cells.

    PubMed

    Ono, Noriaki; Kronenberg, Henry M

    2016-10-01

    Bones are an important component of vertebrates; they grow explosively in early life and maintain their strength throughout life. Bones also possess amazing capabilities to repair-the bone is like new without a scar after complete repair. In recent years, a substantial progress has been made in our understanding on mammalian bone stem cells. Mouse genetic models are powerful tools to understand the cell lineage, giving us better insights into stem cells that regulate bone growth, maintenance and repair. Recent findings about these stem cells raise new questions that require further investigations.

  1. DNA repair in cancer: emerging targets for personalized therapy

    PubMed Central

    Abbotts, Rachel; Thompson, Nicola; Madhusudan, Srinivasan

    2014-01-01

    Genomic deoxyribonucleic acid (DNA) is under constant threat from endogenous and exogenous DNA damaging agents. Mammalian cells have evolved highly conserved DNA repair machinery to process DNA damage and maintain genomic integrity. Impaired DNA repair is a major driver for carcinogenesis and could promote aggressive cancer biology. Interestingly, in established tumors, DNA repair activity is required to counteract oxidative DNA damage that is prevalent in the tumor microenvironment. Emerging clinical data provide compelling evidence that overexpression of DNA repair factors may have prognostic and predictive significance in patients. More recently, DNA repair inhibition has emerged as a promising target for anticancer therapy. Synthetic lethality exploits intergene relationships where the loss of function of either of two related genes is nonlethal, but loss of both causes cell death. Exploiting this approach by targeting DNA repair has emerged as a promising strategy for personalized cancer therapy. In the current review, we focus on recent advances with a particular focus on synthetic lethality targeting in cancer. PMID:24600246

  2. Gene Therapy for Fracture Repair

    DTIC Science & Technology

    2007-05-01

    Stem cell factor is a chemotactic factor for human mast cells. J. Immunol. 153: 3717-3723. 44. Ono I, Yamashita T, Hida T, Jin HY, Ito Y, Hamada H...Stem cell factor is a chemotactic factor for human mast cells. J Immunol 1994;153:3717–23. [37] Ono I, Yamashita T, Hida T, Jin HY, Ito Y, Hamada H

  3. Cell sheet transplantation for heart tissue repair.

    PubMed

    Matsuura, Katsuhisa; Haraguchi, Yuji; Shimizu, Tatsuya; Okano, Teruo

    2013-08-10

    Cell transplantation is attracting considerable attention as the next-generation therapy for treatment of cardiovascular diseases. We have developed cell sheet engineering as a type of scaffold-less tissue engineering for application in myocardial tissue engineering and the repair of injured heart tissue by cell transplantation. Various types of cell sheet transplantation have improved cardiac function in animal models and clinical settings. Furthermore, cell-based tissue engineering with human induced pluripotent stem cell technology is about to create thick vascularized cardiac tissue for cardiac grafts and heart tissue models. In this review, we summarize the current cardiac cell therapies for treating heart failure with cell sheet technology and cell sheet-based tissue engineering.

  4. Gene Therapy for Fracture Repair

    DTIC Science & Technology

    2005-12-01

    chemotactic factor for human mast cells. J. Immunol. 153: 3717-3723. 36 41. Ono I, Yamashita T, Hida T, Jin HY, Ito Y, Hamada H, Akasaka Y, Ishii T...1994;153:3717–23. [37] Ono I, Yamashita T, Hida T, Jin HY, Ito Y, Hamada H, et al. Local administration of hepatocyte growth factor gene enhances the

  5. DNA repair responses in human skin cells

    SciTech Connect

    Hanawalt, P.C.; Liu, S.C.; Parsons, C.S.

    1981-07-01

    Sunlight and some environmental chemical agents produce lesions in the DNA of human skin cells that if unrepaired may interfere with normal functioning of these cells. The most serious outcome of such interactions may be malignancy. It is therefore important to develop an understanding of mechanisms by which the lesions may be repaired or tolerated without deleterious consequences. Our models for the molecular processing of damaged DNA have been derived largely from the study of bacterial systems. Some similarities but significant differences are revealed when human cell responses are tested against these models. It is also of importance to learn DNA repair responses of epidermal keratinocytes for comparison with the more extensive studies that have been carried out with dermal fibroblasts. Our experimental results thus far indicate similarities for the excision-repair of ultraviolet-induced pyrimidine dimers in human keratinocytes and fibroblasts. Both the monoadducts and the interstrand crosslinks produced in DNA by photoactivated 8-methoxypsoralen (PUVA) can be repaired in normal human fibroblasts but not in those from xeroderma pigmentosum patients. The monoadducts, like pyrimidine dimers, are probably the more mutagenic/carcinogenic lesions while the crosslinks are less easily repaired and probably result in more effective blocking of DNA function. It is suggested that a split-dose protocol that maximizes the production of crosslinks while minimizing the yield of monoadducts may be more effective and potentially less carcinogenic than the single ultraviolet exposure regimen in PUVA therapy for psoriasis.

  6. Bone tissue engineering and repair by gene therapy.

    PubMed

    Betz, Volker M; Betz, Oliver B; Harris, Mitchel B; Vrahas, Mark S; Evans, Christopher H

    2008-01-01

    Many clinical conditions require the stimulation of bone growth. The use of recombinant bone morphogenetic proteins does not provide a satisfying solution to these conditions due to delivery problems and high cost. Gene therapy has emerged as a very promising approach for bone repair that overcomes limitations of protein-based therapy. Several preclinical studies have shown that gene transfer technology has the ability to deliver osteogenic molecules to precise anatomical locations at therapeutic levels for sustained periods of time. Both in-vivo and ex-vivo transduction of cells can induce bone formation at ectopic and orthotopic sites. Genetic engineering of adult stem cells from various sources with osteogenic genes has led to enhanced fracture repair, spinal fusion and rapid healing of bone defects in animal models. This review describes current viral and non-viral gene therapy strategies for bone tissue engineering and repair including recent work from the author's laboratory. In addition, the article discusses the potential of gene-enhanced tissue engineering to enter widespread clinical use.

  7. Osteodifferentiated mesenchymal stem cells from bone marrow and adipose tissue express HLA-G and display immunomodulatory properties in HLA-mismatched settings: implications in bone repair therapy.

    PubMed

    Montespan, Florent; Deschaseaux, Frédéric; Sensébé, Luc; Carosella, Edgardo D; Rouas-Freiss, Nathalie

    2014-01-01

    Mesenchymal stem cells (MSCs) are multipotent cells that can be obtained from several sources such as bone marrow and adipose tissue. Depending on the culture conditions, they can differentiate into osteoblasts, chondroblasts, adipocytes, or neurons. In this regard, they constitute promising candidates for cell-based therapy aimed at repairing damaged tissues. In addition, MSCs display immunomodulatory properties through the expression of soluble factors including HLA-G. We here analyse both immunogenicity and immunosuppressive capacity of MSCs derived from bone marrow and adipose tissue before and after osteodifferentiation. Results show that HLA-G expression is maintained after osteodifferentiation and can be boosted in inflammatory conditions mimicked by the addition of IFN-γ and TNF-α. Both MSCs and osteodifferentiated MSCs are hypoimmunogenic and exert immunomodulatory properties in HLA-mismatched settings as they suppress T cell alloproliferation in mixed lymphocyte reactions. Finally, addition of biomaterials that stimulate bone tissue formation did not modify MSC immune properties. As MSCs combine both abilities of osteoregeneration and immunomodulation, they may be considered as allogenic sources for the treatment of bone defects.

  8. Adipose stem cells and skin repair.

    PubMed

    Jeong, Jae Ho

    2010-06-01

    With the discovery of adipose stem cells (ASCs), 40 years after the identification of bone marrow stem cells, a new era of active stem cell therapy has opened. The abundance of stem cells harvested from adipose tissue enables us to instantly apply primary cells without culture expansion. ASCs are already clinically applied in many other purposes such as cell-enriched lipotransfer, wound healing, skin rejuvenation, scar remodeling and skin tissue engineering. Although cellular mechanism of ASCs is not completely understood, recent researches have disclosed some of their unique functions as mesenchymal stem cells. There have been increasing numbers of scientific reports on the therapeutic effect of ASCs on skin repair, scar remodeling and rejuvenation. Wound healing and scar remodeling are complex, multi-cellular processes that involve coordinated efforts of many cell types and various cytokines. Recent reports showed ASCs as a powerful source of skin regeneration because of their capability to provide not only cellular elements, but also numerous cytokines. Currently, other attractive functions of ASCs in the recovery of extrinsic aging and radiation damage are under active investigation. It seems that autologous ASCs have great promise for applications in repair of skin, rejuvenation of aging skin and aging-related skin lesions. This review will focus on the specific roles of ASCs in skin tissue, especially related with wound healing, radiation injury, scar remodeling, skin rejuvenation and skin engineering.

  9. Cell therapy with embryonic stem cell-derived cardiomyocytes encapsulated in injectable nanomatrix gel enhances cell engraftment and promotes cardiac repair.

    PubMed

    Ban, Kiwon; Park, Hun-Jun; Kim, Sangsung; Andukuri, Adinarayana; Cho, Kyu-Won; Hwang, Jung Wook; Cha, Ho Jin; Kim, Sang Yoon; Kim, Woan-Sang; Jun, Ho-Wook; Yoon, Young-Sup

    2014-10-28

    A significant barrier to the therapeutic use of stem cells is poor cell retention in vivo. Here, we evaluate the therapeutic potential and long-term engraftment of cardiomyocytes (CMs) derived from mouse embryonic stem cells (mESCs) encapsulated in an injectable nanomatrix gel consisting of peptide amphiphiles incorporating cell adhesive ligand Arg-Gly-Asp-Ser (PA-RGDS) in experimental myocardial infarction (MI). We cultured rat neonatal CMs in PA-RGDS for 7 days and found that more than 90% of the CMs survived. Next, we intramyocardially injected mouse CM cell line HL-1 CMs with or without PA-RGDS into uninjured hearts. Histologic examination and flow cytometry analysis of digested heart tissues showed approximately 3-fold higher engraftment in the mice that received CMs with PA-RGDS compared to those without PA-RGDS. We further investigated the therapeutic effects and long-term engraftment of mESC-CMs with PA-RGDS on MI in comparison with PBS control, CM-only, and PA-RGDS only. Echocardiography demonstrated that the CM-only and CM+PA-RGDS groups showed higher cardiac function at week 2 compared to other groups. However, from 3 weeks, higher cardiac function was maintained only in the CM+PA-RGDS group; this was sustained for 12 weeks. Confocal microscopic examination of the cardiac tissues harvested at 14 weeks demonstrated sustained engraftment and integration of mESC-CMs into host myocardium in the CM+PA-RGDS group only. This study for the first time demonstrated that PA-RGDS encapsulation can enhance survival of mESC-derived CMs and improve cardiac function post-MI. This nanomatrix gel-mediated stem cell therapy can be a promising option for treating MI.

  10. Human embryonic stem cells and cardiac repair.

    PubMed

    Zhu, Wei-Zhong; Hauch, Kip D; Xu, Chunhui; Laflamme, Michael A

    2009-01-01

    The muscle lost after a myocardial infarction is replaced with noncontractile scar tissue, often initiating heart failure. Whole-organ cardiac transplantation is the only currently available clinical means of replacing the lost muscle, but this option is limited by the inadequate supply of donor hearts. Thus, cell-based cardiac repair has attracted considerable interest as an alternative means of ameliorating cardiac injury. Because of their tremendous capacity for expansion and unquestioned cardiac potential, pluripotent human embryonic stem cells (hESCs) represent an attractive candidate cell source for obtaining cardiomyocytes and other useful mesenchymal cell types for such therapies. Human embryonic stem cell-derived cardiomyocytes exhibit a committed cardiac phenotype and robust proliferative capacity, and recent testing in rodent infarct models indicates that they can partially remuscularize injured hearts and improve contractile function. Although the latter successes give good reason for optimism, considerable challenges remain in the successful application of hESCs to cardiac repair, including the need for preparations of high cardiac purity, improved methods of delivery, and approaches to overcome immune rejection and other causes of graft cell death. This review will describe the phenotype of hESC-derived cardiomyocytes and preclinical experience with these cells and will consider strategies to overcoming the aforementioned challenges.

  11. DNA Base Excision Repair (BER) and Cancer Gene Therapy: Use of the Human N-mythlpurien DNA Glycosylase (MPG) to Sensitize Breast Cancer Cells to Low Dose Chemotherapy

    DTIC Science & Technology

    2003-06-01

    has found that the overexpression of this DNA repair protein is cytotoxic to tumor cells in response to the classic alkylating agent, methyl...SUBJECT TERMS 15. NUMBER OF PAGES DNA repair, methylpurine DNA glycosylase, breast cancer 5 16. PRICE CODE 17. SECURITY CLASSIFICATION 18 . SECURITY...NSN 7540-01-280-5500 Standard Form 298 (Rev. 2-89) Prescribed by ANSI Std. Z39- 18 298-102 BEST AVAILABLE COPY Table of Contents Cover

  12. [Cell based therapy for COPD].

    PubMed

    Kubo, Hiroshi

    2007-04-01

    To develop a new cell based therapy for chronic obstructive pulmonary disease (COPD), we need to understand 1) the role of tissue-specific and bone marrow-derived stem cells, 2) extracellular matrix, and 3) growth factors. Recently, bronchioalveolar stem cells were identified in murine distal lungs. Impairment of these stem cells may cause improper lung repair after inflammation, resulting in pulmonary emphysema. Bone marrow-derived cells are necessary to repair injured lungs. However, the long term role of these cells is not understood yet. Although we need more careful analysis and additional experiments, growth factors, such as hepatocyte growth factor, are good candidates for the new cell based therapy for COPD. Lung was believed as a non-regenerative organ. Based on these recent reports about lung regeneration and stem cells, however, new strategies to treat COPD and a new point of view to understand the pathophysiology of COPD are rising.

  13. How to mend a broken heart: adult and induced pluripotent stem cell therapy for heart repair and regeneration.

    PubMed

    Wegener, Marie; Bader, Augustinus; Giri, Shibashish

    2015-06-01

    The recently developed ability to differentiate primary adult stem cells and induced pluripotent stem cells (iPSCs) into cardiomyocytes is providing unprecedented opportunities to produce an unlimited supply of cardiomyocytes for use in patients with heart disease. Here, we examine the evidence for the preclinical use of such cells for successful heart regeneration. We also describe advances in the identification of new cardiac molecular and cellular targets to induce proliferation of cardiomyocytes for heart regeneration. Such new advances are paving the way for a new innovative drug development process for the treatment of heart disease.

  14. Mending fences: repairing boundaries through ego state therapy.

    PubMed

    Phillips, Maggie

    2013-07-01

    Ego state therapy has often been cited as an effective treatment to help repair fragmentation related to posttraumatic stress and dissociative disorders. This article explores how specialized work with ego states can help to clarify and strengthen internal and external boundaries, create greater boundary flexibility, and contribute to containment and self-regulation. Applications of direct and indirect hypnosis to repair boundary issues through ego state therapy are emphasized, and clinical case examples are used to illustrate results.

  15. (64)Cu-ATSM therapy targets regions with activated DNA repair and enrichment of CD133(+) cells in an HT-29 tumor model: Sensitization with a nucleic acid antimetabolite.

    PubMed

    Yoshii, Yukie; Furukawa, Takako; Matsumoto, Hiroki; Yoshimoto, Mitsuyoshi; Kiyono, Yasushi; Zhang, Ming-Rong; Fujibayashi, Yasuhisa; Saga, Tsuneo

    2016-06-28

    (64)Cu-diacetyl-bis (N(4)-methylthiosemicarbazone) ((64)Cu-ATSM) is a potential theranostic agent targeting the over-reduced state under hypoxia within tumors. Recent clinical Cu-ATSM positron emission tomography studies have revealed a correlation between uptake and poor prognosis; however, the reason is unclear. Here, using a human colon carcinoma HT-29 model, we demonstrated that the intratumoral (64)Cu-ATSM high-uptake regions exhibited malignant characteristics, such as upregulated DNA repair and elevated %CD133(+) cancer stem-like cells. Based on this evidence, we developed a strategy to enhance the efficacy of (64)Cu-ATSM internal radiotherapy (IRT) by inhibiting DNA repair with a nucleic acid (NA) antimetabolite. The results of the analyses showed upregulation of pathways related to DNA repair along with NA incorporation (bromodeoxyuridine uptake) and elevation of %CD133(+) cells in (64)Cu-ATSM high-uptake regions. In an in vivo(64)Cu-ATSM treatment study, co-administration of an NA antimetabolite and (64)Cu-ATSM synergistically inhibited tumor growth, with little toxicity, and effectively reduced %CD133(+) cells. (64)Cu-ATSM therapy targeted malignant tumor regions with activated DNA repair and high concentrations of CD133(+) cells in the HT-29 model. NA antimetabolite co-administration can be an effective approach to enhance the therapeutic effect of (64)Cu-ATSM IRT.

  16. Sublethal and potentially lethal damage repair on thermal neutron capture therapy

    SciTech Connect

    Utsumi, H.; Ichihashi, M.; Kobayashi, T.; Elkind, M.M. )

    1989-07-01

    Tonicity shock or caffeine postirradiation treatment makes evident fast-type potentially lethal damage (PLD). Caffeine expresses fast-type PLD more efficiently than tonicity shock in X-irradiated B-16 mouse melanoma cells, compared with V79 Chinese hamster cells. The survival curves of thermal neutrons for either V79 or B-16 cells exhibit no shoulder. Neither V79 nor B-16 cells show the sublethal damage (SLD) repair of thermal neutrons. Caffeine-sensitive fast-type PLD repairs exist in X-irradiated B-16 cells, as well as V79 cells. The fast-type PLD repair of B-16 cells exposed to thermal neutrons alone is rather less than that of X-irradiated cells. Furthermore, an extremely low level of fast-type PLD repair of B-16 cells with 10B1-paraboronophenylalanine (BPA) preincubation (20 hours) followed by thermal neutron irradiation indicated that 10B(n,alpha)7Li reaction effectively eradicates actively growing melanoma cells. The plateau-phase B-16 cells are well able to repair the slow-type PLD of X-rays. However, cells can not repair the slow-type PLD induced by thermal neutron irradiation with or without 10B1-BPA preincubation. These results suggest that thermal neutron capture therapy can effectively kill radioresistant melanoma cells in both proliferating and quiescent phases.

  17. Gene repair and transposon-mediated gene therapy.

    PubMed

    Richardson, Paul D; Augustin, Lance B; Kren, Betsy T; Steer, Clifford J

    2002-01-01

    The main strategy of gene therapy has traditionally been focused on gene augmentation. This approach typically involves the introduction of an expression system designed to express a specific protein in the transfected cell. Both the basic and clinical sciences have generated enough information to suggest that gene therapy would eventually alter the fundamental practice of modern medicine. However, despite progress in the field, widespread clinical applications and success have not been achieved. The myriad deficiencies associated with gene augmentation have resulted in the development of alternative approaches to treat inherited and acquired genetic disorders. One, derived primarily from the pioneering work of homologous recombination, is gene repair. Simply stated, the process involves targeting the mutation in situ for gene correction and a return to normal gene function. Site-specific genetic repair has many advantages over augmentation although it too is associated with significant limitations. This review outlines the advantages and disadvantages of gene correction. In particular, we discuss technologies based on chimeric RNA/DNA oligonucleotides, single-stranded and triplex-forming oligonucleotides, and small fragment homologous replacement. While each of these approaches is different, they all share a number of common characteristics, including the need for efficient delivery of nucleic acids to the nucleus. In addition, we review the potential application of a novel and exciting nonviral gene augmentation strategy--the Sleeping Beauty transposon system.

  18. Targeted gene repair: the ups and downs of a promising gene therapy approach.

    PubMed

    de Semir, David; Aran, Josep M

    2006-08-01

    As a novel form of molecular medicine based on direct actions over the genes, targeted gene repair has raised consideration recently above classical gene therapy strategies based on genetic augmentation or complementation. Targeted gene repair relies on the local induction of the cell's endogenous DNA repair mechanisms to attain a therapeutic gene conversion event within the genome of the diseased cell. Successful repair has been achieved both in vitro and in vivo with a variety of corrective molecules ranging from oligonucleotides (chimeraplasts, modified single-stranded oligonucleotides, triplex-forming oligonucleotides), to small DNA fragments (small fragment homologous replacement (SFHR)), and even viral vectors (AAV-based). However, controversy on the consistency and lack of reproducibility of early experiments regarding frequencies and persistence of targeted gene repair, particularly for chimeraplasty, has flecked the field. Nevertheless, several hurdles such as inefficient nuclear uptake of the corrective molecules, and misleading assessment of targeted repair frequencies have been identified and are being addressed. One of the key bottlenecks for exploiting the overall potential of the different targeted gene repair modalities is the lack of a detailed knowledge of their mechanisms of action at the molecular level. Several studies are now focusing on the assessment of the specific repair pathway(s) involved (homologous recombination, mismatch repair, etc.), devising additional strategies to increase their activity (using chemotherapeutic drugs, chimeric nucleases, etc.), and assessing the influence of the cell cycle in the regulation of the repair process. Until therapeutic correction frequencies for single gene disorders are reached both in cellular and animal models, precision and undesired side effects of this promising gene therapy approach will not be thoroughly evaluated.

  19. Nanotechnology in cancer therapy: targeting the inhibition of key DNA repair pathways.

    PubMed

    Aziz, K; Nowsheen, S; Georgakilas, A G

    2010-10-01

    Cancer therapy has been changing over the decades as we move away from the administration of broad spectrum cytotoxic drugs and towards the use of therapy targeted for each tumor type. After the induction of DNA damage through chemotherapeutic agents, tumor cells can survive due to their proficient DNA repair pathways, some of which are dysregulated in cancer. Latest improvements in nanotechnology and drug discovery has led to the discovery of some very unique, highly specific and innovative drugs as inhibitors of various DNA repair pathways like base excision repair and double strand break repair. In this review we look at the efficacy and potency of these small chemical molecules to target the processing of DNA damage induced by standard therapeutic agents. Emphasis is given to those drugs currently under clinical trials. We also discuss the future directions of using this nanotechnology to increase the therapeutic ratio in cancer treatment.

  20. Repair of furocoumarin adducts in mammalian cells

    SciTech Connect

    Zolan, M.E.; Smith, C.A.; Hanawalt, P.C.

    1984-12-01

    DNA repair was studied in cultured mammalian cells treated with the furocoumarins 8-methoxypsoralen (8-MOP), aminomethyl trioxsalen, or angelicin and irradiated with near UV light. The amount of DNA cross-linked by 8-MOP in normal human cells decreased by about one-half in 24 hours after treatment; no decrease was observed in xeroderma pigmentosum cells, group A. At present, it is not known to what extent this decrease represents complete repair events at the sites of cross-links. Furocoumarin adducts elicited excision repair in normal human and monkey cells but not in xeroderma pigmentosum group A cells. This excision repair resembled in several aspects that elicited by pyrimidine dimers, formed in DNA by irradiation with 254-nm UV light; however, it appeared that for at least 8-MOP and aminomethyl trioxsalen, removal of adducts was not as efficient as was the removal of pyrimidine dimers. A comparison was also made of repair in the 172-base-pair repetitive alpha-DNA component of monkey cells to repair in the bulk of the genome. Although repair elicited by pyrimidine dimers in alpha-DNA was the same as in the bulk DNA, that following treatment of cells with either aminomethyl trioxsalen or angelicin and near UV was markedly deficient in alpha-DNA. This deficiency reflected the removal of fewer adducts from alpha-DNA after the same initial adduct frequencies. These results could mean that each furocoumarin may produce several structurally distinct adducts to DNA in cells and that the capacity of cellular repair systems to remove these various adducts may vary greatly.

  1. Repair of radiation damage in mammalian cells

    SciTech Connect

    Setlow, R.B.

    1981-01-01

    The responses, such as survival, mutation, and carcinogenesis, of mammalian cells and tissues to radiation are dependent not only on the magnitude of the damage to macromolecular structures - DNA, RNA, protein, and membranes - but on the rates of macromolecular syntheses of cells relative to the half-lives of the damages. Cells possess a number of mechanisms for repairing damage to DNA. If the repair systems are rapid and error free, cells can tolerate much larger doses than if repair is slow or error prone. It is important to understand the effects of radiation and the repair of radiation damage because there exist reasonable amounts of epidemiological data that permits the construction of dose-response curves for humans. The shapes of such curves or the magnitude of the response will depend on repair. Radiation damage is emphasized because: (a) radiation dosimetry, with all its uncertainties for populations, is excellent compared to chemical dosimetry; (b) a number of cancer-prone diseases are known in which there are defects in DNA repair and radiation results in more chromosomal damage in cells from such individuals than in cells from normal individuals; (c) in some cases, specific radiation products in DNA have been correlated with biological effects, and (d) many chemical effects seem to mimic radiation effects. A further reason for emphasizing damage to DNA is the wealth of experimental evidence indicating that damages to DNA can be initiating events in carcinogenesis.

  2. The stem cell secretome and its role in brain repair.

    PubMed

    Drago, Denise; Cossetti, Chiara; Iraci, Nunzio; Gaude, Edoardo; Musco, Giovanna; Bachi, Angela; Pluchino, Stefano

    2013-12-01

    Compelling evidence exists that non-haematopoietic stem cells, including mesenchymal (MSCs) and neural/progenitor stem cells (NPCs), exert a substantial beneficial and therapeutic effect after transplantation in experimental central nervous system (CNS) disease models through the secretion of immune modulatory or neurotrophic paracrine factors. This paracrine hypothesis has inspired an alternative outlook on the use of stem cells in regenerative neurology. In this paradigm, significant repair of the injured brain may be achieved by injecting the biologics secreted by stem cells (secretome), rather than implanting stem cells themselves for direct cell replacement. The stem cell secretome (SCS) includes cytokines, chemokines and growth factors, and has gained increasing attention in recent years because of its multiple implications for the repair, restoration or regeneration of injured tissues. Thanks to recent improvements in SCS profiling and manipulation, investigators are now inspired to harness the SCS as a novel alternative therapeutic option that might ensure more efficient outcomes than current stem cell-based therapies for CNS repair. This review discusses the most recent identification of MSC- and NPC-secreted factors, including those that are trafficked within extracellular membrane vesicles (EVs), and reflects on their potential effects on brain repair. It also examines some of the most convincing advances in molecular profiling that have enabled mapping of the SCS.

  3. The stem cell secretome and its role in brain repair

    PubMed Central

    Drago, Denise; Cossetti, Chiara; Iraci, Nunzio; Gaude, Edoardo; Musco, Giovanna; Bachi, Angela; Pluchino, Stefano

    2014-01-01

    Compelling evidence exists that non-haematopoietic stem cells, including mesenchymal (MSCs) and neural/progenitor stem cells (NPCs), exert a substantial beneficial and therapeutic effect after transplantation in experimental central nervous system (CNS) disease models through the secretion of immune modulatory or neurotrophic paracrine factors. This paracrine hypothesis has inspired an alternative outlook on the use of stem cells in regenerative neurology. In this paradigm, significant repair of the injured brain may be achieved by injecting the biologics secreted by stem cells (secretome), rather than implanting stem cells themselves for direct cell replacement. The stem cell secretome (SCS) includes cytokines, chemokines and growth factors, and has gained increasing attention in recent years because of its multiple implications for the repair, restoration or regeneration of injured tissues. Thanks to recent improvements in SCS profiling and manipulation, investigators are now inspired to harness the SCS as a novel alternative therapeutic option that might ensure more efficient outcomes than current stem cell-based therapies for CNS repair. This review discusses the most recent identification of MSC- and NPC-secreted factors, including those that are trafficked within extracellular membrane vesicles (EVs), and reflects on their potential effects on brain repair. It also examines some of the most convincing advances in molecular profiling that have enabled mapping of the SCS. PMID:23827856

  4. Induced pluripotent stem cells in cartilage repair

    PubMed Central

    Lietman, Steven A

    2016-01-01

    Articular cartilage repair techniques are challenging. Human embryonic stem cells and induced pluripotent stem cells (iPSCs) theoretically provide an unlimited number of specialized cells which could be used in articular cartilage repair. However thus far chondrocytes from iPSCs have been created primarily by viral transfection and with the use of cocultured feeder cells. In addition chondrocytes derived from iPSCs have usually been formed in condensed cell bodies (resembling embryoid bodies) that then require dissolution with consequent substantial loss of cell viability and phenotype. All of these current techniques used to derive chondrocytes from iPSCs are problematic but solutions to these problems are on the horizon. These solutions will make iPSCs a viable alternative for articular cartilage repair in the near future. PMID:27004161

  5. Attenuated DNA damage repair delays therapy-related myeloid neoplasms in a mouse model

    PubMed Central

    Tong, Kit I; Ota, Kazushige; Komuro, Akiyoshi; Ueda, Takeshi; Ito, Akihiko; Anne Koch, C; Okada, Hitoshi

    2016-01-01

    Therapy-related cancers are potentially fatal late life complications for patients who received radio- or chemotherapy. So far, the mouse model showing reduction or delay of these diseases has not been described. We found that the disruption of Aplf in mice moderately attenuated DNA damage repair and, unexpectedly, impeded myeloid neoplasms after exposure to ionizing radiation (IR). Irradiated mutant mice showed higher rates of p53-dependent cell death, fewer chromosomal translocations, and a delay in malignancy-induce;/– mice. Depletion of APLF in non-tumorigenic human cells also markedly reduced the risk of radiation-induced chromosomal aberrations. We therefore conclude that proficient DNA damage repair may promote chromosomal aberrations in normal tissues after irradiation and induce malignant evolution, thus illustrating the potential benefit in sensitizing p53 function by manipulating DNA repair efficiency in cancer patients undergoing genotoxic therapies. PMID:27711078

  6. Mechanical injury and repair of cells

    NASA Technical Reports Server (NTRS)

    Miyake, Katsuya; McNeil, Paul L.

    2003-01-01

    OBJECTIVE: To concisely review the field of cell plasma membrane disruption (torn cell surface) and repair. MAIN POINTS: Plasma membrane disruption is a common form of cell injury under physiologic conditions, after trauma, in certain muscular dystrophies, and during certain forms of clinical intervention. Rapid repair of a disruption is essential to cell survival and involves a complex and active cell response that includes membrane fusion and cytoskeletal activation. Tissues, such as cardiac and skeletal muscle, adapt to a disruption injury by hypertrophying. Cells adapt by increasing the efficiency of their resealing response. CONCLUSION: Plasma membrane disruption is an important cellular event in both health and disease. The disruption repair mechanism is now well understood at the cellular level, but much remains to be learned at the molecular level. Cell and tissue level adaptational responses to the disruption either prevent its further occurrence or facilitate future repairs. Therapeutically useful drugs might result if, using this accumulating knowledge, chemical agents can be developed that can enhance repair or adaptive responses.

  7. Mesenchymal stem cells for bone repair and metabolic bone diseases.

    PubMed

    Undale, Anita H; Westendorf, Jennifer J; Yaszemski, Michael J; Khosla, Sundeep

    2009-10-01

    Human mesenchymal stem cells offer a potential alternative to embryonic stem cells in clinical applications. The ability of these cells to self-renew and differentiate into multiple tissues, including bone, cartilage, fat, and other tissues of mesenchymal origin, makes them an attractive candidate for clinical applications. Patients who experience fracture nonunion and metabolic bone diseases, such as osteogenesis imperfecta and hypophosphatasia, have benefited from human mesenchymal stem cell therapy. Because of their ability to modulate immune responses, allogeneic transplant of these cells may be feasible without a substantial risk of immune rejection. The field of regenerative medicine is still facing considerable challenges; however, with the progress achieved thus far, the promise of stem cell therapy as a viable option for fracture nonunion and metabolic bone diseases is closer to reality. In this review, we update the biology and clinical applicability of human mesenchymal stem cells for bone repair and metabolic bone diseases.

  8. Mesenchymal Stem Cells for Bone Repair and Metabolic Bone Diseases

    PubMed Central

    Undale, Anita H.; Westendorf, Jennifer J.; Yaszemski, Michael J.; Khosla, Sundeep

    2009-01-01

    Human mesenchymal stem cells offer a potential alternative to embryonic stem cells in clinical applications. The ability of these cells to self-renew and differentiate into multiple tissues, including bone, cartilage, fat, and other tissues of mesenchymal origin, makes them an attractive candidate for clinical applications. Patients who experience fracture nonunion and metabolic bone diseases, such as osteogenesis imperfecta and hypophosphatasia, have benefited from human mesenchymal stem cell therapy. Because of their ability to modulate immune responses, allogeneic transplant of these cells may be feasible without a substantial risk of immune rejection. The field of regenerative medicine is still facing considerable challenges; however, with the progress achieved thus far, the promise of stem cell therapy as a viable option for fracture nonunion and metabolic bone diseases is closer to reality. In this review, we update the biology and clinical applicability of human mesenchymal stem cells for bone repair and metabolic bone diseases. PMID:19797778

  9. Stem cell therapy without the cells

    PubMed Central

    Maguire, Greg

    2013-01-01

    As an example of the burgeoning importance of stem cell therapy, this past month the California Institute for Regenerative Medicine (CIRM) has approved $70 million to create a new network of stem cell clinical trial centers. Much work in the last decade has been devoted to developing the use of autologous and allogeneic adult stem cell transplants to treat a number of conditions, including heart attack, dementia, wounds, and immune system-related diseases. The standard model teaches us that adult stem cells exists throughout most of the body and provide a means to regenerate and repair most tissues through replication and differentiation. Although we have often witnessed the medical cart placed in front of the scientific horse in the development of stem cell therapies outside of academic circles, great strides have been made, such as the use of purified stem cells1 instead of whole bone marrow transplants in cancer patients, where physicians avoid re-injecting the patients with their own cancer cells.2 We most often think of stem cell therapy acting to regenerate tissue through replication and then differentiation, but recent studies point to the dramatic effects adult stem cells exert in the repair of various tissues through the release of paracrine and autocrine substances, and not simply through differentiation. Indeed, up to 80% of the therapeutic effect of adult stem cells has been shown to be through paracrine mediated actions.3 That is, the collected types of molecules released by the stem cells, called the secretome, or stem cell released molecules (SRM), number in the 100s, including proteins, microRNA, growth factors, antioxidants, proteasomes, and exosomes, and target a multitude of biological pathways through paracrine actions. The composition of the different molecule types in SRM is state dependent, and varies with cell type and conditions such as age and environment. PMID:24567776

  10. Stem cell death and survival in heart regeneration and repair

    PubMed Central

    Kalvelyte, Audrone; Stulpinas, Aurimas; de Carvalho, Katherine Athayde Teixeira; Guarita-Souza, Luiz Cesar; Foldes, Gabor

    2016-01-01

    Cardiovascular diseases are major causes of mortality and morbidity. Cardiomyocyte apoptosis disrupts cardiac function and leads to cardiac decompensation and terminal heart failure. Delineating the regulatory signaling pathways that orchestrate cell survival in the heart has significant therapeutic implications. Cardiac tissue has limited capacity to regenerate and repair. Stem cell therapy is a successful approach for repairing and regenerating ischemic cardiac tissue; however, transplanted cells display very high death percentage, a problem that affects success of tissue regeneration. Stem cells display multipotency or pluripotency and undergo self-renewal, however these events are negatively influenced by upregulation of cell death machinery that induces the significant decrease in survival and differentiation signals upon cardiovascular injury. While efforts to identify cell types and molecular pathways that promote cardiac tissue regeneration have been productive, studies that focus on blocking the extensive cell death after transplantation are limited. The control of cell death includes multiple networks rather than one crucial pathway, which underlies the challenge of identifying the interaction between various cellular and biochemical components. This review is aimed at exploiting the molecular mechanisms by which stem cells resist death signals to develop into mature and healthy cardiac cells. Specifically, we focus on a number of factors that control death and survival of stem cells upon transplantation and ultimately affect cardiac regeneration. We also discuss potential survival enhancing strategies and how they could be meaningful in the design of targeted therapies that improve cardiac function. PMID:26687129

  11. Stem cells for brain repair in neonatal hypoxia-ischemia.

    PubMed

    Chicha, L; Smith, T; Guzman, R

    2014-01-01

    Neonatal hypoxic-ischemic insults are a significant cause of pediatric encephalopathy, developmental delays, and spastic cerebral palsy. Although the developing brain's plasticity allows for remarkable self-repair, severe disruption of normal myelination and cortical development upon neonatal brain injury are likely to generate life-persisting sensory-motor and cognitive deficits in the growing child. Currently, no treatments are available that can address the long-term consequences. Thus, regenerative medicine appears as a promising avenue to help restore normal developmental processes in affected infants. Stem cell therapy has proven effective in promoting functional recovery in animal models of neonatal hypoxic-ischemic injury and therefore represents a hopeful therapy for this unmet medical condition. Neural stem cells derived from pluripotent stem cells or fetal tissues as well as umbilical cord blood and mesenchymal stem cells have all shown initial success in improving functional outcomes. However, much still remains to be understood about how those stem cells can safely be administered to infants and what their repair mechanisms in the brain are. In this review, we discuss updated research into pathophysiological mechanisms of neonatal brain injury, the types of stem cell therapies currently being tested in this context, and the potential mechanisms through which exogenous stem cells might interact with and influence the developing brain.

  12. CFTR protein repair therapy in cystic fibrosis.

    PubMed

    Quintana-Gallego, Esther; Delgado-Pecellín, Isabel; Calero Acuña, Carmen

    2014-04-01

    Cystic fibrosis is a single gene, autosomal recessive disorder, in which more than 1,900 mutations grouped into 6 classes have been described. It is an example a disease that could be well placed to benefit from personalised medicine. There are currently 2 very different approaches that aim to correct the basic defect: gene therapy, aimed at correcting the genetic alteration, and therapy aimed at correcting the defect in the CFTR protein. The latter is beginning to show promising results, with several molecules under development. Ataluren (PTC124) is a molecule designed to make the ribosomes become less sensitive to the premature stop codons responsible for class i mutations. Lumacaftor (VX-809) is a CFTR corrector directed at class ii mutations, among which Phe508del is the most frequent, with encouraging results. Ivacaftor (VX-770) is a potentiator, the only one marketed to date, which has shown good efficacy for the class iii mutation Gly551Asp in children over the age of 6 and adults. These drugs, or a combination of them, are currently undergoing various clinical trials for other less common genetic mutations. In the last 5 years, CFTR has been designated as a therapeutic target. Ivacaftor is the first drug to treat the basic defect in cystic fibrosis, but only provides a response in a small number of patients. New drugs capable of restoring the CFTR protein damaged by the most common mutations are required.

  13. Role of neural precursor cells in promoting repair following stroke

    PubMed Central

    Dibajnia, Pooya; Morshead, Cindi M

    2013-01-01

    Stem cell-based therapies for the treatment of stroke have received considerable attention. Two broad approaches to stem cell-based therapies have been taken: the transplantation of exogenous stem cells, and the activation of endogenous neural stem and progenitor cells (together termed neural precursors). Studies examining the transplantation of exogenous cells have demonstrated that neural stem and progenitor cells lead to the most clinically promising results. Endogenous activation of neural precursors has also been explored based on the fact that resident precursor cells have the inherent capacity to proliferate, migrate and differentiate into mature neurons in the uninjured adult brain. Studies have revealed that these neural precursor cell behaviours can be activated following stroke, whereby neural precursors will expand in number, migrate to the infarct site and differentiate into neurons. However, this innate response is insufficient to lead to functional recovery, making it necessary to enhance the activation of endogenous precursors to promote tissue repair and functional recovery. Herein we will discuss the current state of the stem cell-based approaches with a focus on endogenous repair to treat the stroke injured brain. PMID:23064725

  14. Gene therapy and peripheral nerve repair: a perspective

    PubMed Central

    Hoyng, Stefan A.; de Winter, Fred; Tannemaat, Martijn R.; Blits, Bas; Malessy, Martijn J. A.; Verhaagen, Joost

    2015-01-01

    Clinical phase I/II studies have demonstrated the safety of gene therapy for a variety of central nervous system disorders, including Canavan’s, Parkinson’s (PD) and Alzheimer’s disease (AD), retinal diseases and pain. The majority of gene therapy studies in the CNS have used adeno-associated viral vectors (AAV) and the first AAV-based therapeutic, a vector encoding lipoprotein lipase, is now marketed in Europe under the name Glybera. These remarkable advances may become relevant to translational research on gene therapy to promote peripheral nervous system (PNS) repair. This short review first summarizes the results of gene therapy in animal models for peripheral nerve repair. Secondly, we identify key areas of future research in the domain of PNS-gene therapy. Finally, a perspective is provided on the path to clinical translation of PNS-gene therapy for traumatic nerve injuries. In the latter section we discuss the route and mode of delivery of the vector to human patients, the efficacy and safety of the vector, and the choice of the patient population for a first possible proof-of-concept clinical study. PMID:26236188

  15. Gene therapy and peripheral nerve repair: a perspective.

    PubMed

    Hoyng, Stefan A; de Winter, Fred; Tannemaat, Martijn R; Blits, Bas; Malessy, Martijn J A; Verhaagen, Joost

    2015-01-01

    Clinical phase I/II studies have demonstrated the safety of gene therapy for a variety of central nervous system disorders, including Canavan's, Parkinson's (PD) and Alzheimer's disease (AD), retinal diseases and pain. The majority of gene therapy studies in the CNS have used adeno-associated viral vectors (AAV) and the first AAV-based therapeutic, a vector encoding lipoprotein lipase, is now marketed in Europe under the name Glybera. These remarkable advances may become relevant to translational research on gene therapy to promote peripheral nervous system (PNS) repair. This short review first summarizes the results of gene therapy in animal models for peripheral nerve repair. Secondly, we identify key areas of future research in the domain of PNS-gene therapy. Finally, a perspective is provided on the path to clinical translation of PNS-gene therapy for traumatic nerve injuries. In the latter section we discuss the route and mode of delivery of the vector to human patients, the efficacy and safety of the vector, and the choice of the patient population for a first possible proof-of-concept clinical study.

  16. Use of stem cells and growth factors in rotator cuff tendon repair.

    PubMed

    Akyol, Engin; Hindocha, Sandip; Khan, Wasim S

    2015-01-01

    In this review, we analysed the role of stem cell and growth factor therapy on rotator cuff tendon repair. The injury to the rotator cuff tendons can be sustained in numerous ways and generally causes significant pain and disability to the affected individual. Following surgical repair of ruptured rotator cuff tendons re-rupture rates can be as high as 20-60%. In order to augment this repair process and to decrease the re-rupture rates tissue engineering methods can be used. These include the use of stem cells and growth factors. Mesenchymal stem cells are stem cells which can differentiate into a variety of connective tissue cell types and can therefore be utilised in repairing tendons. So far there has only been one human study using stem cells in rotator cuff tendon repair. This study has produced a positive result but consisted of only 14 patients and lacks a control group for comparison. Similar work has also been done using growth factors. Both individual and combination growth factor therapy have been used to improve rotator cuff tendon repair. However, the results so far have been disappointing with growth factors. For the purpose of future studies better techniques should be explored with regards to the delivery of stem cells and growth factors as well as the possibility of combining growth factor and stem cell therapy to improve repair rates.

  17. Cell therapy for wound healing.

    PubMed

    You, Hi-Jin; Han, Seung-Kyu

    2014-03-01

    In covering wounds, efforts should include utilization of the safest and least invasive methods with goals of achieving optimal functional and cosmetic outcome. The recent development of advanced wound healing technology has triggered the use of cells to improve wound healing conditions. The purpose of this review is to provide information on clinically available cell-based treatment options for healing of acute and chronic wounds. Compared with a variety of conventional methods, such as skin grafts and local flaps, the cell therapy technique is simple, less time-consuming, and reduces the surgical burden for patients in the repair of acute wounds. Cell therapy has also been developed for chronic wound healing. By transplanting cells with an excellent wound healing capacity profile to chronic wounds, in which wound healing cannot be achieved successfully, attempts are made to convert the wound bed into the environment where maximum wound healing can be achieved. Fibroblasts, keratinocytes, adipose-derived stromal vascular fraction cells, bone marrow stem cells, and platelets have been used for wound healing in clinical practice. Some formulations are commercially available. To establish the cell therapy as a standard treatment, however, further research is needed.

  18. Stem Cells for Neurovascular Repair in Stroke

    PubMed Central

    Shinozuka, Kazutaka; Dailey, Travis; Tajiri, Naoki; Ishikawa, Hiroto; Kim, Dae Won; Pabon, Mibel; Acosta, Sandra; Kaneko, Yuji; Borlongan, Cesar V

    2013-01-01

    Stem cells exert therapeutic effects against ischemic stroke via transplantation of exogenous stem cells or stimulation of endogenous stem cells within the neurogenic niches of subventricular zone and subgranular zone, or recruited from the bone marrow through peripheral circulation. In this paper, we review the different sources of stem cells that have been tested in animal models of stroke. In addition, we discuss specific mechanisms of action, in particular neurovascular repair by endothelial progenitor cells, as key translational research for advancing the clinical applications of stem cells for ischemic stroke. PMID:24077523

  19. Exploiting the homologous recombination DNA repair network for targeted cancer therapy.

    PubMed

    Peng, Guang; Lin, Shiaw-Yih

    2011-02-10

    Genomic instability is a characteristic of cancer cells. In order to maintain genomic integrity, cells have evolved a complex DNA repair system to detect, signal and repair a diversity of DNA lesions. Homologous recombination (HR)-mediated DNA repair represents an error-free repair mechanism to maintain genomic integrity and ensure high-fidelity transmission of genetic information. Deficiencies in HR repair are of tremendous importance in the etiology of human cancers and at the same time offer great opportunities for designing targeted therapeutic strategies. The increase in the number of proteins identified as being involved in HR repair has dramatically shifted our concept of the proteins involved in this process: traditionally viewed as existing in a linear and simple pathway, today they are viewed as existing in a dynamic and interconnected network. Moreover, exploration of the targets within this network that can be modulated by small molecule drugs has led to the discovery of many effective kinase inhibitors, such as ATM, ATR, DNA-PK, CHK1, and CHK2 inhibitors. In preclinical studies, these inhibitors have been shown to sensitize cancer cells to chemotherapy and radiation therapy. The most exciting discovery in the field of HR repair is the identification of the synthetic lethality relationship between poly (ADP-ribose) polymerase (PARP) inhibitors and HR deficiency. The promises of clinical applications of PARP inhibitors and the concept of synthetic lethality also bring challenges into focus. Future research directions in the area of HR repair include determining how to identify the patients most likely to benefit from PARP inhibitors and developing strategies to overcome resistance to PARP inhibitors.

  20. Skin appendage-derived stem cells: cell biology and potential for wound repair.

    PubMed

    Xie, Jiangfan; Yao, Bin; Han, Yutong; Huang, Sha; Fu, Xiaobing

    2016-01-01

    Stem cells residing in the epidermis and skin appendages are imperative for skin homeostasis and regeneration. These stem cells also participate in the repair of the epidermis after injuries, inducing restoration of tissue integrity and function of damaged tissue. Unlike epidermis-derived stem cells, comprehensive knowledge about skin appendage-derived stem cells remains limited. In this review, we summarize the current knowledge of skin appendage-derived stem cells, including their fundamental characteristics, their preferentially expressed biomarkers, and their potential contribution involved in wound repair. Finally, we will also discuss current strategies, future applications, and limitations of these stem cells, attempting to provide some perspectives on optimizing the available therapy in cutaneous repair and regeneration.

  1. Stem cells from deciduous tooth repair mandibular defect in swine.

    PubMed

    Zheng, Y; Liu, Y; Zhang, C M; Zhang, H Y; Li, W H; Shi, S; Le, A D; Wang, S L

    2009-03-01

    Stem cells from human exfoliated deciduous teeth have been identified as a new post-natal stem cell population with multipotential differentiation capabilities, including regeneration of mineralized tissues in vivo. To examine the efficacy of utilizing these stem cells in regenerating orofacial bone defects, we isolated stem cells from miniature pig deciduous teeth and engrafted the critical-size bone defects generated in swine mandible models. Our results indicated that stem cells from miniature pig deciduous teeth, an autologous and easily accessible stem cell source, were able to engraft and regenerate bone to repair critical-size mandibular defects at 6 months post-surgical reconstruction. This pre-clinical study in a large-animal model, specifically swine, allows for testing of a stem cells/scaffold construct in the restoration of orofacial skeletal defects and provides rapid translation of stem-cell-based therapy in orofacial reconstruction in human clinical trials.

  2. DNA repair in murine embryonic stem cells and differentiated cells

    SciTech Connect

    Tichy, Elisia D. Stambrook, Peter J.

    2008-06-10

    Embryonic stem (ES) cells are rapidly proliferating, self-renewing cells that have the capacity to differentiate into all three germ layers to form the embryo proper. Since these cells are critical for embryo formation, they must have robust prophylactic mechanisms to ensure that their genomic integrity is preserved. Indeed, several studies have suggested that ES cells are hypersensitive to DNA damaging agents and readily undergo apoptosis to eliminate damaged cells from the population. Other evidence suggests that DNA damage can cause premature differentiation in these cells. Several laboratories have also begun to investigate the role of DNA repair in the maintenance of ES cell genomic integrity. It does appear that ES cells differ in their capacity to repair damaged DNA compared to differentiated cells. This minireview focuses on repair mechanisms ES cells may use to help preserve genomic integrity and compares available data regarding these mechanisms with those utilized by differentiated cells.

  3. Image-guided therapies for myocardial repair: concepts and practical implementation.

    PubMed

    Bengel, Frank M; George, Richard T; Schuleri, Karl H; Lardo, Albert C; Wollert, Kai C

    2013-08-01

    Cell- and molecule-based therapeutic strategies to support wound healing and regeneration after myocardial infarction (MI) are under development. These emerging therapies aim at sustained preservation of ventricular function by enhancing tissue repair after myocardial ischaemia and reperfusion. Such therapies will benefit from guidance with regard to timing, regional targeting, suitable candidate selection, and effectiveness monitoring. Such guidance is effectively obtained by non-invasive tomographic imaging. Infarct size, tissue characteristics, muscle mass, and chamber geometry can be determined by magnetic resonance imaging and computed tomography. Radionuclide imaging can be used for the tracking of therapeutic agents and for the interrogation of molecular mechanisms such as inflammation, angiogenesis, and extracellular matrix activation. This review article portrays the hypothesis that an integrated approach with an early implementation of structural and molecular tomographic imaging in the development of novel therapies will provide a framework for achieving the goal of improved tissue repair after MI.

  4. Progesterone-Based Therapy Protects Against Influenza by Promoting Lung Repair and Recovery in Females

    PubMed Central

    Vermillion, Meghan S.; Robinson, Dionne P.; Pekosz, Andrew; Mitzner, Wayne

    2016-01-01

    Over 100 million women use progesterone therapies worldwide. Despite having immunomodulatory and repair properties, their effects on the outcome of viral diseases outside of the reproductive tract have not been evaluated. Administration of exogenous progesterone (at concentrations that mimic the luteal phase) to progesterone-depleted adult female mice conferred protection from both lethal and sublethal influenza A virus (IAV) infection. Progesterone treatment altered the inflammatory environment of the lungs, but had no effects on viral load. Progesterone treatment promoted faster recovery by increasing TGF-β, IL-6, IL-22, numbers of regulatory Th17 cells expressing CD39, and cellular proliferation, reducing protein leakage into the airway, improving pulmonary function, and upregulating the epidermal growth factor amphiregulin (AREG) in the lungs. Administration of rAREG to progesterone-depleted females promoted pulmonary repair and improved the outcome of IAV infection. Progesterone-treatment of AREG-deficient females could not restore protection, indicating that progesterone-mediated induction of AREG caused repair in the lungs and accelerated recovery from IAV infection. Repair and production of AREG by damaged respiratory epithelial cell cultures in vitro was increased by progesterone. Our results illustrate that progesterone is a critical host factor mediating production of AREG by epithelial cells and pulmonary tissue repair following infection, which has important implications for women’s health. PMID:27631986

  5. Stem cells and cardiac repair: a critical analysis.

    PubMed

    Dinsmore, Jonathan H; Dib, Nabil

    2008-03-01

    Utilizing stem cells to repair the damaged heart has seen an intense amount of activity over the last 5 years or so. There are currently multiple clinical studies in progress to test the efficacy of various different cell therapy approaches for the repair of damaged myocardium that were only just beginning to be tested in preclinical animal studies a few years earlier. This rapid transition from preclinical to clinical testing is striking and is not typical of the customary timeframe for the progress of a therapy from bench-to-bedside. Doubtless, there will be many more trials to follow in the upcoming years. With the plethora of trials and cell alternatives, there has come not only great enthusiasm for the potential of the therapy, but also great confusion about what has been achieved. Cell therapy has the potential to do what no drug can: regenerate and replace damaged tissue with healthy tissue. Drugs may be effective at slowing the progression of heart failure, but none can stop or reverse the process. However, tissue repair is not a simple process, although the idea on its surface is quite simple. Understanding cells, the signals that they respond to, and the keys to appropriate survival and tissue formation are orders of magnitude more complicated than understanding the pathways targeted by most drugs. Drugs and their metabolites can be monitored, quantified, and their effects correlated to circulating levels in the body. Not so for most cell therapies. It is quite difficult to measure cell survival except through ex vivo techniques like histological analysis of the target organ. This makes the emphasis on preclinical research all the more important because it is only in the animal studies that research has the opportunity to readily harvest the target tissues and perform the detailed analyses of what has happened with the cells. This need for detailed and usually time-intensive research in animal studies stands in contrast to the rapidity with which

  6. Transcatheter Mitral Valve Repair Therapies: Evolution, Status and Challenges.

    PubMed

    Espiritu, Daniella; Onohara, Daisuke; Kalra, Kanika; Sarin, Eric L; Padala, Muralidhar

    2017-02-01

    Mitral regurgitation is a common cardiac valve lesion, developing from primary lesions of the mitral valve or secondary to cardiomyopathies. Moderate or higher severity of mitral regurgitation imposes significant volume overload on the left ventricle, causing permanent structural and functional deterioration of the myocardium and heart failure. Timely correction of regurgitation is essential to preserve cardiac function, but surgical mitral valve repair is often delayed due to the risks of open heart surgery. Since correction of mitral regurgitation can provide symptomatic relief and halt progressive cardiac dysfunction, transcatheter mitral valve repair technologies are emerging as alternative therapies. In this approach, the mitral valve is repaired either with sutures or implants that are delivered to the native valve on catheters introduced into the cardiovascular system under image guidance, through small vascular or ventricular ports. Several transcatheter mitral valve technologies are in development, but limited clinical success has been achieved. In this review, we present a historical perspective of mitral valve repair, review the transcatheter technologies emerging from surgical concepts, the challenges they face in achieving successful clinical application, and the increasing rigor of safety and durability standards for new transcatheter valve technologies.

  7. Nonclinical safety strategies for stem cell therapies

    SciTech Connect

    Sharpe, Michaela E.; Morton, Daniel; Rossi, Annamaria

    2012-08-01

    Recent breakthroughs in stem cell biology, especially the development of the induced pluripotent stem cell techniques, have generated tremendous enthusiasm and efforts to explore the therapeutic potential of stem cells in regenerative medicine. Stem cell therapies are being considered for the treatment of degenerative diseases, inflammatory conditions, cancer and repair of damaged tissue. The safety of a stem cell therapy depends on many factors including the type of cell therapy, the differentiation status and proliferation capacity of the cells, the route of administration, the intended clinical location, long term survival of the product and/or engraftment, the need for repeated administration, the disease to be treated and the age of the population. Understanding the product profile of the intended therapy is crucial to the development of the nonclinical safety study design.

  8. Mononuclear cells and vascular repair in HHT.

    PubMed

    Dingenouts, Calinda K E; Goumans, Marie-José; Bakker, Wineke

    2015-01-01

    Hereditary hemorrhagic telangiectasia (HHT) or Rendu-Osler-Weber disease is a rare genetic vascular disorder known for its endothelial dysplasia causing arteriovenous malformations and severe bleedings. HHT-1 and HHT-2 are the most prevalent variants and are caused by heterozygous mutations in endoglin and activin receptor-like kinase 1, respectively. An undervalued aspect of the disease is that HHT patients experience persistent inflammation. Although endothelial and mural cells have been the main research focus trying to unravel the mechanism behind the disease, wound healing is a process with a delicate balance between inflammatory and vascular cells. Inflammatory cells are part of the mononuclear cells (MNCs) fraction, and can, next to eliciting an immune response, also have angiogenic potential. This biphasic effect of MNC can hold a promising mechanism to further elucidate treatment strategies for HHT patients. Before MNC are able to contribute to repair, they need to home to and retain in ischemic and damaged tissue. Directed migration (homing) of MNCs following tissue damage is regulated by the stromal cell derived factor 1 (SDF1). MNCs that express the C-X-C chemokine receptor 4 (CXCR4) migrate toward the tightly regulated gradient of SDF1. This directed migration of monocytes and lymphocytes can be inhibited by dipeptidyl peptidase 4 (DPP4). Interestingly, MNC of HHT patients express elevated levels of DPP4 and show impaired homing toward damaged tissue. Impaired homing capacity of the MNCs might therefore contribute to the impaired angiogenesis and tissue repair observed in HHT patients. This review summarizes recent studies regarding the role of MNCs in the etiology of HHT and vascular repair, and evaluates the efficacy of DPP4 inhibition in tissue integrity and repair.

  9. Stem cells and exosomes in cardiac repair.

    PubMed

    Singla, Dinender K

    2016-04-01

    Cardiac diseases currently lead in the number of deaths per year, giving rise an interest in transplanting embryonic and adult stem cells as a means to improve damaged tissue from conditions such as myocardial infarction and coronary artery disease. After testing these cells as a treatment option in both animal and human models, it is believed that these cells improve the damaged tissue primarily through the release of autocrine and paracrine factors. Major concerns such as teratoma formation, immune response, difficulty harvesting cells, and limited cell proliferation and differentiation, hinder the routine use of these cells as a treatment option in the clinic. The advent of stem cell-derived exosomes circumvent those concerns, while still providing the growth factors, miRNA, and additional cell protective factors that aid in repairing and regenerating the damaged tissue. These exosomes have been found to be anti-apoptotic, anti-fibrotic, pro-angiogenic, as well as enhance cardiac differentiation, all of which are key to repairing damaged tissue. As such, stem cell derived exosomes are considered to be a potential new and novel approach in the treatment of various cardiac diseases.

  10. Biodistribution of LV-TSTA transduced rat bone marrow cells used for "ex-vivo" regional gene therapy for bone repair.

    PubMed

    Alaee, Farhang; Bartholomae, Cynthia; Sugiyama, Osamu; Virk, Mandeep S; Drissi, Hicham; Wu, Qian; Schmidt, Manfred; Lieberman, Jay R

    2015-01-01

    "Ex vivo" regional gene therapy using lentiviral (LV) vectors to over-express bone morphogenetic protein 2 (BMP-2) is an effective way to enhance bone healing in animal models. Here, we evaluated two different "ex vivo" approaches using either "same day" rat bone marrow cells (SDRBMCs) or cultured rat bone marrow cells (C-RBMCs), both transduced with a LV based two-step transcriptional activation system overexpressing GFP (LV-TSTA-EGFP), to assess the fate of the transduced cells and the safety of this approach. The transduced cells were implanted in femoral defects of syngeneic rats. Animals were sacrificed at 4, 14, 28 and 56 days after surgery (n=5 per group). Viral copies were detectable in the defect site of SD-RBMC group and gradually declined at 8w (5 log decrease compared to 4d). In the C-RBMC animals, there was a 2-4 log decline in the viral copy numbers at 2w and 4w, but at 8w there was a relative rise (about 100 fold) in the number of the viral vectors in the defect site of 4 (out of 5) animals compared to the previous time points. For both gene transfer approaches, the pattern of tissue distribution was non-specific and no histological abnormalities were noted in either group. In summary, we demonstrated that the LV-TSTA transduced cells remain in the defect site for at least 56 days, though the numbers decreased over time. There were no consistent findings of viral copies in internal organs which is encouraging with respect to the development of this strategy for use in humans.

  11. The Challenge and the Promise of Bone Marrow Cells for Human Cartilage Repair.

    PubMed

    Chu, Constance R

    2015-04-01

    The cartilage repair potential of bone marrow-derived stem cells has been well described. Harnessing this potential for human articular cartilage repair remains challenging. Accessing bone marrow repair cells through marrow stimulation techniques such as microfracture is readily achieved with generally good but inconsistent results. Animal and human studies show feasibility for ex vivo processing of bone marrow to isolate, concentrate, and culture mesenchymal stem cells. Nevertheless, it has been difficult to show consistent and clinically meaningful improvement using bone marrow cell preparations above what has been achieved with microfracture. Consequently, microfracture continues to be the simplest and most commonly used method to enhance repair of focal articular cartilage defects. Emerging preclinical work in the equine model suggests a role for enhancing marrow-stimulation techniques through the use of natural scaffolds such as autologous platelet enriched fibrin as well as optimization of joint biology through localized gene therapy to support cartilage repair. In contrast to joint replacement where inert materials of known mechanical properties are used, host biology determines the relative success, failure, and durability of cartilage repair. As such, development of personalized strategies to improve the quality and durability of bone marrow cell-based articular cartilage repair represent exciting new areas of inquiry. Continued advances in stem cell biology, scaffold technologies, and methods to delineate and enhance host biology, both systemically and within the joint, hold promise for harnessing the full power of bone marrow cells to facilitate cartilage repair and regeneration.

  12. DNA repair genes of mammalian cells

    SciTech Connect

    Thompson, L.H.; Brookman, K.W.; Salazar, E.P.; Fuscoe, J.C.; Weber, C.A.

    1985-09-27

    In the CHO cell line various mutations affecting DNA repair have been obtained. Mutants that belong to five genetic complementation groups for UV sensitivity and resemble the cells from individuals having the cancer-prone genetic disorder xeroderma pigmentosum were previously identified. Each mutant is defective in the incision step of nucleotide excision repair and hypersensitive to bulky DNA lesions. A sixth genetic complementation group for UV sensitivity has now been identified with UV27-1. These UV mutants can be divided into two subgroups; only Groups 2 and 4 are extremely sensitive to mitomycin C and other DNA cross-linking agents. The clear-cut phenotypes of the CHO mutants have allowed us to construct hybrid cells by fusion with human lymphocytes and thereby identify which human chromosomes carry genes that correct the CHO mutations. The first two mutants analyzed, UV20 (excision-repair deficient; UV Group 2) and EM9, which has very high SCE, are both corrected by chromosome 19. 46 refs., 3 figs.

  13. Intraoperative Stem Cell Therapy

    PubMed Central

    Coelho, Mónica Beato; Cabral, Joaquim M.S.; Karp, Jeffrey M.

    2013-01-01

    Stem cells hold significant promise for regeneration of tissue defects and disease-modifying therapies. Although numerous promising stem cell approaches are advancing in clinical trials, intraoperative stem cell therapies offer more immediate hope by integrating an autologous cell source with a well-established surgical intervention in a single procedure. Herein, the major developments in intraoperative stem cell approaches, from in vivo models to clinical studies, are reviewed, and the potential regenerative mechanisms and the roles of different cell populations in the regeneration process are discussed. Although intraoperative stem cell therapies have been shown to be safe and effective for several indications, there are still critical challenges to be tackled prior to adoption into the standard surgical armamentarium. PMID:22809140

  14. The role of DNA repair in the pluripotency and differentiation of human stem cells.

    PubMed

    Rocha, Clarissa Ribeiro Reily; Lerner, Leticia Koch; Okamoto, Oswaldo Keith; Marchetto, Maria Carolina; Menck, Carlos Frederico Martins

    2013-01-01

    All living cells utilize intricate DNA repair mechanisms to address numerous types of DNA lesions and to preserve genomic integrity, and pluripotent stem cells have specific needs due to their remarkable ability of self-renewal and differentiation into different functional cell types. Not surprisingly, human stem cells possess a highly efficient DNA repair network that becomes less efficient upon differentiation. Moreover, these cells also have an anaerobic metabolism, which reduces the mitochondria number and the likelihood of oxidative stress, which is highly related to genomic instability. If DNA lesions are not repaired, human stem cells easily undergo senescence, cell death or differentiation, as part of their DNA damage response, avoiding the propagation of stem cells carrying mutations and genomic alterations. Interestingly, cancer stem cells and typical stem cells share not only the differentiation potential but also their capacity to respond to DNA damage, with important implications for cancer therapy using genotoxic agents. On the other hand, the preservation of the adult stem cell pool, and the ability of cells to deal with DNA damage, is essential for normal development, reducing processes of neurodegeneration and premature aging, as one can observe on clinical phenotypes of many human genetic diseases with defects in DNA repair processes. Finally, several recent findings suggest that DNA repair also plays a fundamental role in maintaining the pluripotency and differentiation potential of embryonic stem cells, as well as that of induced pluripotent stem (iPS) cells. DNA repair processes also seem to be necessary for the reprogramming of human cells when iPS cells are produced. Thus, the understanding of how cultured pluripotent stem cells ensure the genetic stability are highly relevant for their safe therapeutic application, at the same time that cellular therapy is a hope for DNA repair deficient patients.

  15. Stem/progenitor cells: a potential source of retina-specific cells for retinal repair.

    PubMed

    Bi, Yong-Yan; Feng, Dong-Fu; Pan, Dong-Chao

    2009-11-01

    Retinal injury generally results in permanent visual disturbance or even blindness. Any effort to restore vision in such condition would require replacement of the highly specialized retinal cells. Stem/progenitor cells have been proposed as a potential source of new retina-specific cells to replace those lost due to retina injury. Evidence to date suggests that continued development of stem cell therapies may ultimately lead to viable treatment options for retina injury. A wide range of stem/progenitor cells from various sources is currently being investigated for the treatment of retinal injury. This article reviews the recent achievements about stem/progenitor cell source for retinal repair.

  16. Cell Therapy in Dermatology

    PubMed Central

    Petrof, Gabriela; Abdul-Wahab, Alya; McGrath, John A.

    2014-01-01

    Harnessing the regenerative capacity of keratinocytes and fibroblasts from human skin has created new opportunities to develop cell-based therapies for patients. Cultured cells and bioengineered skin products are being used to treat patients with inherited and acquired skin disorders associated with defective skin, and further clinical trials of new products are in progress. The capacity of extracutaneous sources of cells such as bone marrow is also being investigated for its plasticity in regenerating skin, and new strategies, such as the derivation of inducible pluripotent stem cells, also hold great promise for future cell therapies in dermatology. This article reviews some of the preclinical and clinical studies and future directions relating to cell therapy in dermatology, particularly for inherited skin diseases associated with fragile skin and poor wound healing. PMID:24890834

  17. Induced DNA repair pathway in mammalian cells

    SciTech Connect

    Overberg, R.

    1985-01-01

    The survival of cultured rat kangaroo cells (PtK-2) and human xeroderma pigmentosum cells incubated with 5 ..mu..M cycloheximide subsequent to ultraviolet irradiation is lower than that of cells incubated without cycloheximide. The drop in survival is considerably larger than that produced by incubation of unirradiated cells with cycloheximide. The phenomenon was also observed when PtK-2 cells were incubated with emetine, another protein synthesis inhibitor, or with 5,6-dichloro-1-..beta..-D-ribofuranosylbenzimidazole, a RNA synthesis inhibitor. PtK cells which received a preliminary UV treatment followed by an incubation period without cycloheximide and then a second irradiation and 24 hour incubation with cycloheximide, survived the effects of the second irradiation better than cells which were incubated in the presence of cycloheximide after the first and second UV irradiation. The application of cycloheximide for 24 hours after UV irradiation of PtK cells resulted in one-half as many 6-thioguanine resistant cells as compared to the number of 6-thioguanine resistant cells found when cycloheximide was not used. These experiments indicate that a UV-inducible cycloheximide-sensitive DNA repair pathway is present in PtK and xeroderma pigmentosum cells, which is error-prone in PtK cells.

  18. Hematopoietic Stem Cells Therapies.

    PubMed

    Chivu-Economescu, Mihaela; Rubach, Martin

    2017-01-01

    Stem cell-based therapies are recognized as a new way to treat various diseases and injuries, with a wide range of health benefits. The goal is to heal or replace diseased or destroyed organs or body parts with healthy new cells provided by stem cell transplantation. The current practical form of stem cell therapy is the hematopoietic stem cells transplant applied for the treatment of hematological disorders. There are over 2100 clinical studies in progress concerning hematopoietic stem cell therapies. All of them are using hematopoietic stem cells to treat various diseases like: cancers, leukemia, lymphoma, cardiac failure, neural disorders, auto-immune diseases, immunodeficiency, metabolic or genetic disorders. Several challenges are to be addressed prior to developing and applying large scale cell therapies: 1) to explain and control the mechanisms of differentiation and development toward a specific cell type needed to treat the disease, 2) to obtain a sufficient number of desired cell type for transplantation, 3) to overcome the immune rejection and 4) to show that transplanted cells fulfill their normal functions in vivo after transplants.

  19. Adult stem cells for cardiac repair: a choice between skeletal myoblasts and bone marrow stem cells.

    PubMed

    Ye, Lei; Haider, Husnain Kh; Sim, Eugene K W

    2006-01-01

    The real promise of a stem cell-based approach for cardiac regeneration and repair lies in the promotion of myogenesis and angiogenesis at the site of the cell graft to achieve both structural and functional benefits. Despite all of the progress and promise in this field, many unanswered questions remain; the answers to these questions will provide the much-needed breakthrough to harness the real benefits of cell therapy for the heart in the clinical perspective. One of the major issues is the choice of donor cell type for transplantation. Multiple cell types with varying potentials have been assessed for their ability to repopulate the infarcted myocardium; however, only the adult stem cells, that is, skeletal myoblasts (SkM) and bone marrow-derived stem cells (BMC), have been translated from the laboratory bench to clinical use. Which of these two cell types will provide the best option for clinical application in heart cell therapy remains arguable. With results pouring in from the long-term follow-ups of previously conducted phase I clinical studies, and with the onset of phase II clinical trials involving larger population of patients, transplantation of stem cells as a sole therapy without an adjunct conventional revascularization procedure will provide a deeper insight into the effectiveness of this approach. The present article discusses the pros and cons of using SkM and BMC individually or in combination for cardiac repair, and critically analyzes the progress made with each cell type.

  20. Nanoparticle-based monitoring of cell therapy

    NASA Astrophysics Data System (ADS)

    Xu, Chenjie; Mu, Luye; Roes, Isaac; Miranda-Nieves, David; Nahrendorf, Matthias; Ankrum, James A.; Zhao, Weian; Karp, Jeffrey M.

    2011-12-01

    Exogenous cell therapy aims to replace/repair diseased or dysfunctional cells and promises to revolutionize medicine by restoring tissue and organ function. To develop effective cell therapy, the location, distribution and long-term persistence of transplanted cells must be evaluated. Nanoparticle (NP) based imaging technologies have the potential to track transplanted cells non-invasively. Here we summarize the most recent advances in NP-based cell tracking with emphasis on (1) the design criteria for cell tracking NPs, (2) protocols for cell labeling, (3) a comparison of available imaging modalities and their corresponding contrast agents, (4) a summary of preclinical studies on NP-based cell tracking and finally (5) perspectives and future directions.

  1. Stem Cells for Augmenting Tendon Repair

    PubMed Central

    Gulotta, Lawrence V.; Chaudhury, Salma; Wiznia, Daniel

    2012-01-01

    Tendon healing is fraught with complications such as reruptures and adhesion formation due to the formation of scar tissue at the injury site as opposed to the regeneration of native tissue. Stem cells are an attractive option in developing cell-based therapies to improve tendon healing. However, several questions remain to be answered before stem cells can be used clinically. Specifically, the type of stem cell, the amount of cells, and the proper combination of growth factors or mechanical stimuli to induce differentiation all remain to be seen. This paper outlines the current literature on the use of stem cells for tendon augmentation. PMID:22190960

  2. Functional Polymorphisms of Base Excision Repair Genes XRCC1 and APEX1 Predict Risk of Radiation Pneumonitis in Patients With Non-Small Cell Lung Cancer Treated With Definitive Radiation Therapy

    SciTech Connect

    Yin Ming; Liao Zhongxing; Liu Zhensheng; Wang, Li-E; Gomez, Daniel; Komaki, Ritsuko; Wei Qingyi

    2011-11-01

    Purpose: To explore whether functional single nucleotide polymorphisms (SNPs) of base-excision repair genes are predictors of radiation treatment-related pneumonitis (RP), we investigated associations between functional SNPs of ADPRT, APEX1, and XRCC1 and RP development. Methods and Materials: We genotyped SNPs of ADPRT (rs1136410 [V762A]), XRCC1 (rs1799782 [R194W], rs25489 [R280H], and rs25487 [Q399R]), and APEX1 (rs1130409 [D148E]) in 165 patients with non-small cell lung cancer (NSCLC) who received definitive chemoradiation therapy. Results were assessed by both Logistic and Cox regression models for RP risk. Kaplan-Meier curves were generated for the cumulative RP probability by the genotypes. Results: We found that SNPs of XRCC1 Q399R and APEX1 D148E each had a significant effect on the development of Grade {>=}2 RP (XRCC1: AA vs. GG, adjusted hazard ratio [HR] = 0.48, 95% confidence interval [CI], 0.24-0.97; APEX1: GG vs. TT, adjusted HR = 3.61, 95% CI, 1.64-7.93) in an allele-dose response manner (Trend tests: p = 0.040 and 0.001, respectively). The number of the combined protective XRCC1 A and APEX1 T alleles (from 0 to 4) also showed a significant trend of predicting RP risk (p = 0.001). Conclusions: SNPs of the base-excision repair genes may be biomarkers for susceptibility to RP. Larger prospective studies are needed to validate our findings.

  3. New design of nucleotide excision repair (NER) inhibitors for combination cancer therapy.

    PubMed

    Gentile, Francesco; Tuszynski, Jack A; Barakat, Khaled H

    2016-04-01

    Many cancer chemotherapy agents act by targeting the DNA of cancer cells, causing substantial damage within their genome and causing them to undergo apoptosis. An effective DNA repair pathway in cancer cells can act in a reverse way by removing these drug-induced DNA lesions, allowing cancer cells to survive, grow and proliferate. In this context, DNA repair inhibitors opened a new avenue in cancer treatment, by blocking the DNA repair mechanisms from removing the chemotherapy-mediated DNA damage. In particular, the nucleotide excision repair (NER) involves more than thirty protein-protein interactions and removes DNA adducts caused by platinum-based chemotherapy. The excision repair cross-complementation group 1 (ERCC1)-xeroderma pigmentosum, complementation group A (XPA) protein (XPA-ERCC1) complex seems to be one of the most promising targets in this pathway. ERCC1 is over expressed in cancer cells and the only known cellular function so far for XPA is to recruit ERCC1 to the damaged point. Here, we build upon our recent advances in identifying inhibitors for this interaction and continue our efforts to rationally design more effective and potent regulators for the NER pathway. We employed in silico drug design techniques to: (1) identify compounds similar to the recently discovered inhibitors, but more effective at inhibiting the XPA-ERCC1 interactions, and (2) identify different scaffolds to develop novel lead compounds. Two known inhibitor structures have been used as starting points for two ligand/structure-hybrid virtual screening approaches. The findings described here form a milestone in discovering novel inhibitors for the NER pathway aiming at improving the efficacy of current platinum-based therapy, by modulating the XPA-ERCC1 interaction.

  4. Anti-Muscarinic Adjunct Therapy Accelerates Functional Human Oligodendrocyte Repair

    PubMed Central

    Abiraman, Kavitha; Pol, Suyog U.; O'Bara, Melanie A.; Chen, Guang-Di; Khaku, Zainab M.; Wang, Jing; Thorn, David; Vedia, Bansi H.; Ekwegbalu, Ezinne C.; Li, Jun-Xu; Salvi, Richard J.

    2015-01-01

    Therapeutic repair of myelin disorders may be limited by the relatively slow rate of human oligodendrocyte differentiation. To identify appropriate pharmacological targets with which to accelerate differentiation of human oligodendrocyte progenitors (hOPCs) directly, we used CD140a/O4-based FACS of human forebrain and microarray to hOPC-specific receptors. Among these, we identified CHRM3, a M3R muscarinic acetylcholine receptor, as being restricted to oligodendrocyte-biased CD140a+O4+ cells. Muscarinic agonist treatment of hOPCs resulted in a specific and dose-dependent blockade of oligodendrocyte commitment. Conversely, when hOPCs were cocultured with human neurons, M3R antagonist treatment stimulated oligodendrocytic differentiation. Systemic treatment with solifenacin, an FDA-approved muscarinic receptor antagonist, increased oligodendrocyte differentiation of transplanted hOPCs in hypomyelinated shiverer/rag2 brain. Importantly, solifenacin treatment of engrafted animals reduced auditory brainstem response interpeak latency, indicative of increased conduction velocity and thereby enhanced functional repair. Therefore, solifenacin and other selective muscarinic antagonists represent new adjunct approaches to accelerate repair by engrafted human progenitors. PMID:25716865

  5. Inhibition of Topoisomerase (DNA) I (TOP1): DNA Damage Repair and Anticancer Therapy

    PubMed Central

    Xu, Yang; Her, Chengtao

    2015-01-01

    Most chemotherapy regimens contain at least one DNA-damaging agent that preferentially affects the growth of cancer cells. This strategy takes advantage of the differences in cell proliferation between normal and cancer cells. Chemotherapeutic drugs are usually designed to target rapid-dividing cells because sustained proliferation is a common feature of cancer [1,2]. Rapid DNA replication is essential for highly proliferative cells, thus blocking of DNA replication will create numerous mutations and/or chromosome rearrangements—ultimately triggering cell death [3]. Along these lines, DNA topoisomerase inhibitors are of great interest because they help to maintain strand breaks generated by topoisomerases during replication. In this article, we discuss the characteristics of topoisomerase (DNA) I (TOP1) and its inhibitors, as well as the underlying DNA repair pathways and the use of TOP1 inhibitors in cancer therapy. PMID:26287259

  6. [Advance of neurogenic erectile dysfunction therapy by stem cells].

    PubMed

    Shen, Han-Jian; Zhu, Guang-You

    2010-06-01

    Neurogenic erectile dysfunction (NED) commonly results from erectile nerve damage. Recent researches have focused on the preclinical study of stem cell-based therapies targeted at repairing and protecting nervi erigentes. In this paper, researches of NESCs, MDSCs, ASCs and MSCs in NED are reviewed. Early studies have demonstrated that stem cells and gene modified stem cells were effective to the therapy of ED, even likely to cure ED. Stem cells are expected to be applied in the clinical therapy of NED. Stem cells as a new therapy technique will bring up a new challenge in forensic clinical medicine.

  7. TRIM72 modulates caveolar endocytosis in repair of lung cells.

    PubMed

    Nagre, Nagaraja; Wang, Shaohua; Kellett, Thomas; Kanagasabai, Ragu; Deng, Jing; Nishi, Miyuki; Shilo, Konstantin; Oeckler, Richard A; Yalowich, Jack C; Takeshima, Hiroshi; Christman, John; Hubmayr, Rolf D; Zhao, Xiaoli

    2016-03-01

    Alveolar epithelial and endothelial cell injury is a major feature of the acute respiratory distress syndrome, in particular when in conjunction with ventilation therapies. Previously we showed [Kim SC, Kellett T, Wang S, Nishi M, Nagre N, Zhou B, Flodby P, Shilo K, Ghadiali SN, Takeshima H, Hubmayr RD, Zhao X. Am J Physiol Lung Cell Mol Physiol 307: L449-L459, 2014.] that tripartite motif protein 72 (TRIM72) is essential for amending alveolar epithelial cell injury. Here, we posit that TRIM72 improves cellular integrity through its interaction with caveolin 1 (Cav1). Our data show that, in primary type I alveolar epithelial cells, lack of TRIM72 led to significant reduction of Cav1 at the plasma membrane, accompanied by marked attenuation of caveolar endocytosis. Meanwhile, lentivirus-mediated overexpression of TRIM72 selectively increases caveolar endocytosis in rat lung epithelial cells, suggesting a functional association between these two. Further coimmunoprecipitation assays show that deletion of either functional domain of TRIM72, i.e., RING, B-box, coiled-coil, or PRY-SPRY, abolishes the physical interaction between TRIM72 and Cav1, suggesting that all theoretical domains of TRIM72 are required to forge a strong interaction between these two molecules. Moreover, in vivo studies showed that injurious ventilation-induced lung cell death was significantly increased in knockout (KO) TRIM72(KO) and Cav1(KO) lungs compared with wild-type controls and was particularly pronounced in double KO mutants. Apoptosis was accompanied by accentuation of gross lung injury manifestations in the TRIM72(KO) and Cav1(KO) mice. Our data show that TRIM72 directly and indirectly modulates caveolar endocytosis, an essential process involved in repair of lung epithelial cells through removal of plasma membrane wounds. Given TRIM72's role in endomembrane trafficking and cell repair, we consider this molecule an attractive therapeutic target for patients with injured lungs.

  8. DNA damage induced by boron neutron capture therapy is partially repaired by DNA ligase IV.

    PubMed

    Kondo, Natsuko; Sakurai, Yoshinori; Hirota, Yuki; Tanaka, Hiroki; Watanabe, Tsubasa; Nakagawa, Yosuke; Narabayashi, Masaru; Kinashi, Yuko; Miyatake, Shin-ichi; Hasegawa, Masatoshi; Suzuki, Minoru; Masunaga, Shin-ichiro; Ohnishi, Takeo; Ono, Koji

    2016-03-01

    Boron neutron capture therapy (BNCT) is a particle radiation therapy that involves the use of a thermal or epithermal neutron beam in combination with a boron ((10)B)-containing compound that specifically accumulates in tumor. (10)B captures neutrons and the resultant fission reaction produces an alpha ((4)He) particle and a recoiled lithium nucleus ((7)Li). These particles have the characteristics of high linear energy transfer (LET) radiation and therefore have marked biological effects. High-LET radiation is a potent inducer of DNA damage, specifically of DNA double-strand breaks (DSBs). The aim of the present study was to clarify the role of DNA ligase IV, a key player in the non-homologous end-joining repair pathway, in the repair of BNCT-induced DSBs. We analyzed the cellular sensitivity of the mouse embryonic fibroblast cell lines Lig4-/- p53-/- and Lig4+/+ p53-/- to irradiation using a thermal neutron beam in the presence or absence of (10)B-para-boronophenylalanine (BPA). The Lig4-/- p53-/- cell line had a higher sensitivity than the Lig4+/+ p53-/-cell line to irradiation with the beam alone or the beam in combination with BPA. In BNCT (with BPA), both cell lines exhibited a reduction of the 50 % survival dose (D 50) by a factor of 1.4 compared with gamma-ray and neutron mixed beam (without BPA). Although it was found that (10)B uptake was higher in the Lig4+/+ p53-/- than in the Lig4-/- p53-/- cell line, the latter showed higher sensitivity than the former, even when compared at an equivalent (10)B concentration. These results indicate that BNCT-induced DNA damage is partially repaired using DNA ligase IV.

  9. Isolating human DNA repair genes using rodent-cell mutants

    SciTech Connect

    Thompson, L.H.; Weber, C.A.; Brookman, K.W.; Salazar, E.P.; Stewart, S.A.; Mitchell, D.L.

    1987-03-23

    The DNA repair systems of rodent and human cells appear to be at least as complex genetically as those in lower eukaryotes and bacteria. The use of mutant lines of rodent cells as a means of identifying human repair genes by functional complementation offers a new approach toward studying the role of repair in mutagenesis and carcinogenesis. In each of six cases examined using hybrid cells, specific human chromosomes have been identified that correct CHO cell mutations affecting repair of damage from uv or ionizing radiations. This finding suggests that both the repair genes and proteins may be virtually interchangeable between rodent and human cells. Using cosmid vectors, human repair genes that map to chromosome 19 have cloned as functional sequences: ERCC2 and XRCC1. ERCC1 was found to have homology with the yeast excision repair gene RAD10. Transformants of repair-deficient cell lines carrying the corresponding human gene show efficient correction of repair capacity by all criteria examined. 39 refs., 1 fig., 1 tab.

  10. Stem cell repair of physeal cartilage.

    PubMed

    Ahn, Jae I; Terry Canale, S; Butler, Stephanie D; Hasty, Karen A

    2004-11-01

    To evaluate the ability of cultured mesenchymal stem cells (MSC) to repair physeal defects, MSC-matrix constructs with 5% gelatin (group A), 10% gelatin/Gelfoam (Pharmacia, Peapack, NJ) (group B), and MSC grown in the presence of TGF-beta3 with Gelfoam (group C) were implanted in proximal tibial physeal defects created in 20 immature rabbits. Control groups (untreated partial defect and partial defect treated with Gelfoam) showed bony bar formation with varus deformities of 30 degrees and 28 degrees, respectively. Group A had an average 23 degrees varus deformity with bony bridge formation, and group B had mild varus angulation (average 14 degrees) of the proximal tibia. In group C, there was no significant varus deformity (average 9 degrees), and histologic examination showed that some of the columnation areas interspersed with chondrocytes were irregularly arranged in the matrix. These findings suggest that repair of physeal defects can be enhanced by the implantation of MSC cultured with TGF-beta3.

  11. Bone marrow cells repair cigarette smoke-induced emphysema in rats.

    PubMed

    Huh, Jin Won; Kim, Sun-Yong; Lee, Ji Hyun; Lee, Jin-Seok; Van Ta, Quang; Kim, Mijung; Oh, Yeon-Mok; Lee, Yun-Song; Lee, Sang-Do

    2011-09-01

    The therapeutic potential of stem cells in chronic obstructive pulmonary disease is not well known although stem cell therapy is effective in models of other pulmonary diseases. We tested the capacities of bone marrow cells (BMCs), mesenchymal stem cells (MSCs), and conditioned media of MSCs (MSC-CM) to repair cigarette smoke-induced emphysema. Inbred female Lewis rats were exposed to cigarette smoke for 6 mo and then received BMCs, MSCs, or MSC-CM from male Lewis rats. For 2 mo after injection, the BMC treatment gradually alleviated the cigarette smoke-induced emphysema and restored the increased mean linear intercept. The BMC treatment significantly increased cell proliferation and the number of small pulmonary vessels, reduced apoptotic cell death, attenuated the mean pulmonary arterial pressure, and inhibited muscularization in small pulmonary vessels. However, only a few male donor cells were detected from 1 day to 1 mo after BMC administration. The MSCs and cell-free MSC-CM also induced the repair of emphysema and increased the number of small pulmonary vessels. Our data show that BMC, MSCs, and MSC-CM treatment repaired cigarette smoke-induced emphysema. The repair activity of these treatments is consistent with a paracrine effect rather than stem cell engraftment because most of the donor cells disappeared and because cell-free MSC-CM also induced the repair.

  12. [Immunological cell therapy].

    PubMed

    Shibata, Masahiko; Gonda, Kenji; Kumamoto, Kensuke; Takenoshita, Seiichi

    2014-01-01

    Recently there is a great advance in anti-colorectal cancer treatment. Several molecular targeting agents, mostly are antibody drugs, are playing an important role. It has recently been proven that new approaches using antibody to immunological checkpoints are effective against certain types of cancer. This is one of the reasons why cancer immunotherapy is now focused in the clinics. In this chapter, several effective immunotherapy against cancer are shown and discussed. Among several types of cancer immunotherapy, immunological cell therapy including lymphokine activated killer (LAK) cell, cytotoxic T lymphocytes (CTL), gamma delta T cell and dendritic cell therapies are reviewed. Major mechanisms that disturb cancer immunotherapy such as escape mechanisms are also discussed.

  13. Influence of calorie reduction on DNA repair capacity of human peripheral blood mononuclear cells.

    PubMed

    Matt, Katja; Burger, Katharina; Gebhard, Daniel; Bergemann, Jörg

    2016-03-01

    Caloric restrictive feeding prolongs the lifespan of a variety of model organisms like rodents and invertebrates. It has been shown that caloric restriction reduces age-related as well as overall-mortality, reduces oxidative stress and influences DNA repair ability positively. There are numerous studies underlining this, but fewer studies involving humans exist. To contribute to a better understanding of the correlation of calorie reduction and DNA repair in humans, we adapted the host cell reactivation assay to an application with human peripheral blood mononuclear cells. Furthermore, we used this reliable and reproducible assay to research the influence of a special kind of calorie reduction, namely F. X. Mayr therapy, on DNA repair capacity. We found a positive effect in all persons with low pre-existing DNA repair capacity. In individuals with normal pre-existing DNA repair capacity, no effect on DNA repair capacity was detectable. Decline of DNA repair, accumulation of oxidative DNA damages, mitochondrial dysfunction, telomere shortening as well as caloric intake are widely thought to contribute to aging. With regard to that, our results can be considered as a strong indication that calorie reduction may support DNA repair processes and thus contribute to a healthier aging.

  14. DNA repair and radiation sensitivity in mammalian cells

    SciTech Connect

    Chen, D.J.C.; Stackhouse, M. ); Chen, D.S. . Dept. of Radiation Oncology)

    1993-01-01

    Ionizing radiation induces various types of damage in mammalian cells including DNA single-strand breaks, DNA double-strand breaks (DSB), DNA-protein cross links, and altered DNA bases. Although human cells can repair many of these lesions there is little detailed knowledge of the nature of the genes and the encoded enzymes that control these repair processes. We report here on the cellular and genetic analyses of DNA double-strand break repair deficient mammalian cells. It has been well established that the DNA double-strand break is one of the major lesions induced by ionizing radiation. Utilizing rodent repair-deficient mutant, we have shown that the genes responsible for DNA double-strand break repair are also responsible for the cellular expression of radiation sensitivity. The molecular genetic analysis of DSB repair in rodent/human hybrid cells indicate that at least 6 different genes in mammalian cells are responsible for the repair of radiation-induced DNA double-strand breaks. Mapping and the prospect of cloning of human radiation repair genes are reviewed. Understanding the molecular and genetic basis of radiation sensitivity and DNA repair in man will provide a rational foundation to predict the individual risk associated with radiation exposure and to prevent radiation-induced genetic damage in the human population.

  15. DNA repair and radiation sensitivity in mammalian cells

    SciTech Connect

    Chen, D.J.C.; Stackhouse, M.; Chen, D.S.

    1993-02-01

    Ionizing radiation induces various types of damage in mammalian cells including DNA single-strand breaks, DNA double-strand breaks (DSB), DNA-protein cross links, and altered DNA bases. Although human cells can repair many of these lesions there is little detailed knowledge of the nature of the genes and the encoded enzymes that control these repair processes. We report here on the cellular and genetic analyses of DNA double-strand break repair deficient mammalian cells. It has been well established that the DNA double-strand break is one of the major lesions induced by ionizing radiation. Utilizing rodent repair-deficient mutant, we have shown that the genes responsible for DNA double-strand break repair are also responsible for the cellular expression of radiation sensitivity. The molecular genetic analysis of DSB repair in rodent/human hybrid cells indicate that at least 6 different genes in mammalian cells are responsible for the repair of radiation-induced DNA double-strand breaks. Mapping and the prospect of cloning of human radiation repair genes are reviewed. Understanding the molecular and genetic basis of radiation sensitivity and DNA repair in man will provide a rational foundation to predict the individual risk associated with radiation exposure and to prevent radiation-induced genetic damage in the human population.

  16. A peek into the possible future of management of articular cartilage injuries: gene therapy and scaffolds for cartilage repair.

    PubMed

    Kim, Hubert T; Zaffagnini, Stefano; Mizuno, Shuichi; Abelow, Stephen; Safran, Marc R

    2006-10-01

    Two rapidly progressing areas of research will likely contribute to cartilage repair procedures in the foreseeable future: gene therapy and synthetic scaffolds. Gene therapy refers to the transfer of new genetic information to cells that contribute to the cartilage repair process. This approach allows for manipulation of cartilage repair at the cellular and molecular level. Scaffolds are the core technology for the next generation of autologous cartilage implantation procedures in which synthetic matrices are used in conjunction with chondrocytes. This approach can be improved further using bioreactor technologies to enhance the production of extracellular matrix proteins by chondrocytes seeded onto a scaffold. The resulting "neo-cartilage implant" matures within the bioreactor, and can then be used to fill cartilage defects.

  17. DNA damage and gene therapy of xeroderma pigmentosum, a human DNA repair-deficient disease.

    PubMed

    Dupuy, Aurélie; Sarasin, Alain

    2015-06-01

    Xeroderma pigmentosum (XP) is a genetic disease characterized by hypersensitivity to ultra-violet and a very high risk of skin cancer induction on exposed body sites. This syndrome is caused by germinal mutations on nucleotide excision repair genes. No cure is available for these patients except a complete protection from all types of UV radiations. We reviewed the various techniques to complement or to correct the genetic defect in XP cells. We, particularly, developed the correction of XP-C skin cells using the fidelity of the homologous recombination pathway during repair of double-strand break (DSB) in the presence of XPC wild type sequences. We used engineered nucleases (meganuclease or TALE nuclease) to induce a DSB located at 90 bp of the mutation to be corrected. Expression of specific TALE nuclease in the presence of a repair matrix containing a long stretch of homologous wild type XPC sequences allowed us a successful gene correction of the original TG deletion found in numerous North African XP patients. Some engineered nucleases are sensitive to epigenetic modifications, such as cytosine methylation. In case of methylated sequences to be corrected, modified nucleases or demethylation of the whole genome should be envisaged. Overall, we showed that specifically-designed TALE-nuclease allowed us to correct a 2 bp deletion in the XPC gene leading to patient's cells proficient for DNA repair and showing normal UV-sensitivity. The corrected gene is still in the same position in the human genome and under the regulation of its physiological promoter. This result is a first step toward gene therapy in XP patients.

  18. Adoptive cell therapy for sarcoma

    PubMed Central

    Mata, Melinda; Gottschalk, Stephen

    2015-01-01

    Current therapy for sarcomas, though effective in treating local disease, is often ineffective for patients with recurrent or metastatic disease. To improve outcomes, novel approaches are needed and cell therapy has the potential to meet this need since it does not rely on the cytotoxic mechanisms of conventional therapies. The recent successes of T-cell therapies for hematological malignancies have led to renewed interest in exploring cell therapies for solid tumors such as sarcomas. In this review, we will discuss current cell therapies for sarcoma with special emphasis on genetic approaches to improve the effector function of adoptively transferred cells. PMID:25572477

  19. Adipose, Bone Marrow and Synovial Joint-Derived Mesenchymal Stem Cells for Cartilage Repair

    PubMed Central

    Fellows, Christopher R.; Matta, Csaba; Zakany, Roza; Khan, Ilyas M.; Mobasheri, Ali

    2016-01-01

    Current cell-based repair strategies have proven unsuccessful for treating cartilage defects and osteoarthritic lesions, consequently advances in innovative therapeutics are required and mesenchymal stem cell-based (MSC) therapies are an expanding area of investigation. MSCs are capable of differentiating into multiple cell lineages and exerting paracrine effects. Due to their easy isolation, expansion, and low immunogenicity, MSCs are an attractive option for regenerative medicine for joint repair. Recent studies have identified several MSC tissue reservoirs including in adipose tissue, bone marrow, cartilage, periosteum, and muscle. MSCs isolated from these discrete tissue niches exhibit distinct biological activities, and have enhanced regenerative potentials for different tissue types. Each MSC type has advantages and disadvantages for cartilage repair and their use in a clinical setting is a balance between expediency and effectiveness. In this review we explore the challenges associated with cartilage repair and regeneration using MSC-based cell therapies and provide an overview of phenotype, biological activities, and functional properties for each MSC population. This paper also specifically explores the therapeutic potential of each type of MSC, particularly focusing on which cells are capable of producing stratified hyaline-like articular cartilage regeneration. Finally we highlight areas for future investigation. Given that patients present with a variety of problems it is unlikely that cartilage regeneration will be a simple “one size fits all,” but more likely an array of solutions that need to be applied systematically to achieve regeneration of a biomechanically competent repair tissue. PMID:28066501

  20. Repair of atrial septal defect with Eisenmenger syndrome after long-term sildenafil therapy.

    PubMed

    Kim, Young-Hwue; Yu, Jeong Jin; Yun, Tae-Jin; Lee, Yonghee; Kim, Yong Beom; Choi, Hyung Soon; Jhang, Won Kyoung; Shin, Hong Ju; Park, Jeong-Jun; Seo, Dong-Man; Ko, Jae-Kon; Park, In-Sook

    2010-05-01

    We report a woman with atrial septal defect and severe pulmonary hypertension with 25.0 Wood unit.m(2) of indexed total pulmonary vascular resistance. She underwent successful corrective repair of atrial septal defect after 2 years of treatment with sildenafil, and has been monitored for 4 years after repair. This case supports a "treat and repair" approach using advanced pulmonary vasodilator therapy in selected patients with inoperable severe pulmonary hypertension associated with atrial septal defect.

  1. [Progress in researches on stem cell therapy for erectile dysfunction].

    PubMed

    Jiang, Yuan-bin; Gou, Xin

    2009-10-01

    Erectile dysfunction (ED) commonly results from endothelial dysfunction and erectile nerve damage. Recent researches have focused on the preclinical studies of stem cell-based therapies targeted at repairing penile endothelium and protecting erectile nerves. Early studies showed that stem cell- or gene-modified stem cell-based therapies may have enduring efficacy and eventually lead to a cure for ED. Such stem cells as embryonic, mesenchymal, muscle-derived and adipose-derived ones and endothelial progenitor cells all have differentiation potentials and obvious advantages in protecting and repairing both nervi erigentes and corpus cavernosum vascular endothelial cells. Stem cell-based therapies promise to be an effective approach to human erectile dysfunction.

  2. Germline mutations in DNA repair genes may predict neoadjuvant therapy response in triple negative breast patients.

    PubMed

    Spugnesi, Laura; Gabriele, Michele; Scarpitta, Rosa; Tancredi, Mariella; Maresca, Luisa; Gambino, Gaetana; Collavoli, Anita; Aretini, Paolo; Bertolini, Ilaria; Salvadori, Barbara; Landucci, Elisabetta; Fontana, Andrea; Rossetti, Elena; Roncella, Manuela; Naccarato, Giuseppe Antonio; Caligo, Maria Adelaide

    2016-12-01

    Triple negative breast cancers (TNBCs) represent about 15-20% of all breast cancer cases and are characterized by a complex molecular heterogeneity. Some TNBCs exhibit clinical and pathological properties similar to BRCA-mutated tumors, without actually bearing a mutation in BRCA genes. This "BRCAness" phenotype may be explained by germline mutations in other genes involved in DNA repair. Although respond to chemotherapy with alkylating agents, they have a high risk of recurrence and progression. Some studies have shown the efficacy of neoadjuvant therapy in TNBC patients with DNA repair defects, but proper biomarkers of DNA repair deficiency are still needed. Here, we investigated if mutations in DNA repair genes may be correlated with anthracyclines/taxanes neoadjuvant therapy response. DNA from 19 TNBC patients undergoing neoadjuvant therapy were subjected to next generation sequencing of a panel of 24 genes in DNA repair and breast cancer predisposition. In this study, 5 of 19 patients (26%) carried a pathogenic mutation in BRCA1, PALB2, RAD51C and two patients carried a probable pathogenic missense variant. Moreover, VUS (Variants of Unknown Significance) in other genes, predicted to be deleterious by in silico tools, were detected in five patients. Germline mutations in DNA repair genes were found to be associated with the group of TNBC patients who responded to therapy. We conclude that a subgroup of TNBC patients have defects in DNA repair genes, other than BRCA1, and such patients respond favourably to neoadjuvant anthracyclines/taxanes therapy. © 2016 Wiley Periodicals, Inc.

  3. Lacrimal Gland Repair Using Progenitor Cells.

    PubMed

    Gromova, Anastasia; Voronov, Dmitry A; Yoshida, Miya; Thotakura, Suharika; Meech, Robyn; Dartt, Darlene A; Makarenkova, Helen P

    2017-01-01

    In humans, the lacrimal gland (LG) is the primary contributor to the aqueous layer of the tear film. Production of tears in insufficient quantity or of inadequate quality may lead to aqueous-deficiency dry eye (ADDE). Currently there is no cure for ADDE. The development of strategies to reliably isolate LG stem/progenitor cells from the LG tissue brings great promise for the design of cell replacement therapies for patients with ADDE. We analyzed the therapeutic potential of epithelial progenitor cells (EPCPs) isolated from adult wild-type mouse LGs by transplanting them into the LGs of TSP -1(-/-) mice, which represent a novel mouse model for ADDE. TSP-1(-/-) mice are normal at birth but progressively develop a chronic form of ocular surface disease, characterized by deterioration, inflammation, and secretory dysfunction of the lacrimal gland. Our study shows that, among c-kit-positive epithelial cell adhesion molecule (EpCAM(+) ) populations sorted from mouse LGs, the c-kit(+) dim/EpCAM(+) /Sca1 (-) /CD34 (-) /CD45 (-) cells have the hallmarks of an epithelial cell progenitor population. Isolated EPCPs express pluripotency factors and markers of the epithelial cell lineage Runx1 and EpCAM, and they form acini and ducts when grown in reaggregated three-dimensional cultures. Moreover, when transplanted into injured or "diseased" LGs, they engraft into acinar and ductal compartments. EPCP-injected TSP-1(-/-) LGs showed reduction of cell infiltration, differentiation of the donor EPCPs within secretory acini, and substantial improvement in LG structural integrity and function. This study provides the first evidence for the effective use of adult EPCP cell transplantation to rescue LG dysfunction in a model system. Stem Cells Translational Medicine 2017;6:88-98.

  4. Lacrimal Gland Repair Using Progenitor Cells.

    PubMed

    Gromova, Anastasia; Voronov, Dmitry A; Yoshida, Miya; Thotakura, Suharika; Meech, Robyn; Dartt, Darlene A; Makarenkova, Helen P

    2016-08-15

    : In humans, the lacrimal gland (LG) is the primary contributor to the aqueous layer of the tear film. Production of tears in insufficient quantity or of inadequate quality may lead to aqueous-deficiency dry eye (ADDE). Currently there is no cure for ADDE. The development of strategies to reliably isolate LG stem/progenitor cells from the LG tissue brings great promise for the design of cell replacement therapies for patients with ADDE. We analyzed the therapeutic potential of epithelial progenitor cells (EPCPs) isolated from adult wild-type mouse LGs by transplanting them into the LGs of TSP-1(-/-) mice, which represent a novel mouse model for ADDE. TSP-1(-/-) mice are normal at birth but progressively develop a chronic form of ocular surface disease, characterized by deterioration, inflammation, and secretory dysfunction of the lacrimal gland. Our study shows that, among c-kit-positive epithelial cell adhesion molecule (EpCAM(+)) populations sorted from mouse LGs, the c-kit(+)dim/EpCAM(+)/Sca1(-)/CD34(-)/CD45(-) cells have the hallmarks of an epithelial cell progenitor population. Isolated EPCPs express pluripotency factors and markers of the epithelial cell lineage Runx1 and EpCAM, and they form acini and ducts when grown in reaggregated three-dimensional cultures. Moreover, when transplanted into injured or "diseased" LGs, they engraft into acinar and ductal compartments. EPCP-injected TSP-1(-/-) LGs showed reduction of cell infiltration, differentiation of the donor EPCPs within secretory acini, and substantial improvement in LG structural integrity and function. This study provides the first evidence for the effective use of adult EPCP cell transplantation to rescue LG dysfunction in a model system.

  5. Scarring, stem cells, scaffolds and skin repair.

    PubMed

    Markeson, Daniel; Pleat, Jonathon M; Sharpe, Justin R; Harris, Adrian L; Seifalian, Alexander M; Watt, Suzanne M

    2015-06-01

    The treatment of full thickness skin loss, which can be extensive in the case of large burns, continues to represent a challenging clinical entity. This is due to an on-going inability to produce a suitable tissue engineered substrate that can satisfactorily replicate the epidermal and dermal in vivo niches to fulfil both aesthetic and functional demands. The current gold standard treatment of autologous skin grafting is inadequate because of poor textural durability, scarring and associated contracture, and because of a paucity of donor sites in larger burns. Tissue engineering has seen exponential growth in recent years with a number of 'off-the-shelf' dermal and epidermal substitutes now available. Each has its own limitations. In this review, we examine normal wound repair in relation to stem/progenitor cells that are intimately involved in this process within the dermal niche. Endothelial precursors, in particular, are examined closely and their phenotype, morphology and enrichment from multiple sources are described in an attempt to provide some clarity regarding the controversy surrounding their classification and role in vasculogenesis. We also review the role of the next generation of cellularized scaffolds and smart biomaterials that attempt to improve the revascularisation of artificial grafts, the rate of wound healing and the final cosmetic and functional outcome.

  6. The repair Schwann cell and its function in regenerating nerves

    PubMed Central

    Mirsky, R.

    2016-01-01

    Abstract Nerve injury triggers the conversion of myelin and non‐myelin (Remak) Schwann cells to a cell phenotype specialized to promote repair. Distal to damage, these repair Schwann cells provide the necessary signals and spatial cues for the survival of injured neurons, axonal regeneration and target reinnervation. The conversion to repair Schwann cells involves de‐differentiation together with alternative differentiation, or activation, a combination that is typical of cell type conversions often referred to as (direct or lineage) reprogramming. Thus, injury‐induced Schwann cell reprogramming involves down‐regulation of myelin genes combined with activation of a set of repair‐supportive features, including up‐regulation of trophic factors, elevation of cytokines as part of the innate immune response, myelin clearance by activation of myelin autophagy in Schwann cells and macrophage recruitment, and the formation of regeneration tracks, Bungner's bands, for directing axons to their targets. This repair programme is controlled transcriptionally by mechanisms involving the transcription factor c‐Jun, which is rapidly up‐regulated in Schwann cells after injury. In the absence of c‐Jun, damage results in the formation of a dysfunctional repair cell, neuronal death and failure of functional recovery. c‐Jun, although not required for Schwann cell development, is therefore central to the reprogramming of myelin and non‐myelin (Remak) Schwann cells to repair cells after injury. In future, the signalling that specifies this cell requires further analysis so that pharmacological tools that boost and maintain the repair Schwann cell phenotype can be developed. PMID:26864683

  7. DNA repair in microgravity: studies on bacteria and mammalian cells in the experiments REPAIR and KINETICS.

    PubMed

    Horneck, G; Rettberg, P; Baumstark-Khan, C; Rink, H; Kozubek, S; Schäfer, M; Schmitz, C

    1996-06-27

    The impact of microgravity on cellular repair processes was tested in the space experiments REPAIR and KINETICS, which were performed during the IML-2 mission in the Biorack of ESA: (a) survival of spores of Bacillus subtilis HA101 after UV-irradiation (up to 340 J m-2) in the experiment REPAIR; (b) in the experiment KINETICS the kinetics of DNA repair in three different test systems: rejoining of X-ray-induced DNA strand breaks (B1) in cells of Escherichia coli B/r (120 Gy) and (B2) in human fibroblasts (5 and 10 Gy) as well as (B3) induction of the SOS response after gamma-irradiation (300 Gy) of cells of Escherichia coli PQ37. Cells were irradiated prior to the space mission and were kept in a non-metabolic state (metabolically inactive spores of B. subtilis on membrane filters, frozen cells of E. coli and human fibroblasts) until incubation in orbit. Germination and growth of B. subtilis were initiated by humidification, E. coli and fibroblasts were thawed up and incubated at 37 degrees C for defined repair periods (up to 4.5 h), thereafter they were frozen again for laboratory analysis. Relevant controls were performed in-flight (1 x g reference centrifuge) and on ground (1 x g and 1.4 x g) The results show no significant differences between the microgravity samples and the corresponding controls neither in the survival curves nor in the kinetics of DNA strand break rejoining and induction of the SOS response (proven by Student's t-test, 2 P = 0.05). These observations provide evidence that in the microgravity environment cells are able to repair radiation-induced DNA damage close to normality. The results suggest that a disturbance of cellular repair processes in the microgravity environment might not be the explanation for the reported synergism of radiation and microgravity.

  8. Satellite Cells Contribution to Exercise Mediated Muscle Hypertrophy and Repair

    PubMed Central

    Bazgir, Behzad; Fathi, Rouhollah; Rezazadeh Valojerdi, Mojtaba; Mozdziak, Paul; Asgari, Alireza

    2017-01-01

    Satellite cells (SCs) are the most abundant skeletal muscle stem cells. They are widely recognized for their contributions to maintenance of muscle mass, regeneration and hypertrophy during the human life span. These cells are good candidates for cell therapy due to their self-renewal capabilities and presence in an undifferentiated form. Presently, a significant gap exists between our knowledge of SCs behavior and their application as a means for human skeletal muscle tissue repair and regeneration. Both physiological and pathological stimuli potentially affect SCs activation, proliferation, and terminal differentiation the former category being the focus of this article. Activation of SCs occurs following exercise, post-training micro-injuries, and electrical stimulation. Exercise, as a potent and natural stimulus, is at the center of numerous studies on SC activation and relevant fields. According to research, different exercise modalities end with various effects. This review article attempts to picture the state of the art of the SCs life span and their engagement in muscle regeneration and hypertrophy in exercise. PMID:28042532

  9. Perspectives on the combination of radiotherapy and targeted therapy with DNA repair inhibitors in the treatment of pancreatic cancer

    PubMed Central

    Yang, Shih-Hung; Kuo, Ting-Chun; Wu, Hsu; Guo, Jhe-Cyuan; Hsu, Chiun; Hsu, Chih-Hung; Tien, Yu-Wen; Yeh, Kun-Huei; Cheng, Ann-Lii; Kuo, Sung-Hsin

    2016-01-01

    Pancreatic cancer is highly lethal. Current research that combines radiation with targeted therapy may dramatically improve prognosis. Cancerous cells are characterized by unstable genomes and activation of DNA repair pathways, which are indicated by increased phosphorylation of numerous factors, including H2AX, ATM, ATR, Chk1, Chk2, DNA-PKcs, Rad51, and Ku70/Ku80 heterodimers. Radiotherapy causes DNA damage. Cancer cells can be made more sensitive to the effects of radiation (radiosensitization) through inhibition of DNA repair pathways. The synergistic effects, of two or more combined non-lethal treatments, led to co-administration of chemotherapy and radiosensitization in BRCA-defective cells and patients, with promising results. ATM/Chk2 and ATR/Chk1 pathways are principal regulators of cell cycle arrest, following DNA double-strand or single-strand breaks. DNA double-stranded breaks activate DNA-dependent protein kinase, catalytic subunit (DNA-PKcs). It forms a holoenzyme with Ku70/Ku80 heterodimers, called DNA-PK, which catalyzes the joining of nonhomologous ends. This is the primary repair pathway utilized in human cells after exposure to ionizing radiation. Radiosensitization, induced by inhibitors of ATM, ATR, Chk1, Chk2, Wee1, PP2A, or DNA-PK, has been demonstrated in preclinical pancreatic cancer studies. Clinical trials are underway. Development of agents that inhibit DNA repair pathways to be clinically used in combination with radiotherapy is warranted for the treatment of pancreatic cancer. PMID:27621574

  10. Single stem cell gene therapy for genetic skin disease.

    PubMed

    Larsimont, Jean-Christophe; Blanpain, Cédric

    2015-04-01

    Stem cell gene therapy followed by transplantation into damaged regions of the skin has been successfully used to treat genetic skin blistering disorder. Usually, many stem cells are virally transduced to obtain a sufficient number of genetically corrected cells required for successful transplantation, as genetic insertion in every stem cell cannot be precisely defined. In this issue of EMBO Molecular Medicine, Droz-Georget Lathion et al developed a new strategy for ex vivo single cell gene therapy that allows extensive genomic and functional characterization of the genetically repaired individual cells before they can be used in clinical settings.

  11. Mesenchymal stem cells in kidney inflammation and repair.

    PubMed

    Wise, Andrea F; Ricardo, Sharon D

    2012-01-01

    Mesenchymal stem cells are a heterogeneous population of fibroblast-like stromal cells that have been isolated from the bone marrow and a number of organs and tissues including the kidney. They have multipotent and self-renewing properties and can differentiate into cells of the mesodermal lineage. Following their administration in vivo, mesenchymal stem cells migrate to damaged kidney tissue where they produce an array of anti-inflammatory cytokines and chemokines that can alter the course of injury. Mesenchymal stem cells are thought to elicit repair through paracrine and/or endocrine mechanisms that modulate the immune response resulting in tissue repair and cellular replacement. This review will discuss the features of mesenchymal stem cells and the factors they release that protect against kidney injury; the mechanisms of homing and engraftment to sites of inflammation; and further elucidate the immunomodulatory effect of mesenchymal stem cells and their ability to alter macrophage phenotype in a setting of kidney damage and repair.

  12. PERIPHERAL NERVE REGENERATION: CELL THERAPY AND NEUROTROPHIC FACTORS

    PubMed Central

    Sebben, Alessandra Deise; Lichtenfels, Martina; da Silva, Jefferson Luis Braga

    2015-01-01

    Peripheral nerve trauma results in functional loss in the innervated organ, and recovery without surgical intervention is rare. Many surgical techniques can be used for nerve repair. Among these, the tubulization technique can be highlighted: this allows regenerative factors to be introduced into the chamber. Cell therapy and tissue engineering have arisen as an alternative for stimulating and aiding peripheral nerve regeneration. Therefore, the aim of this review was to provide a survey and analysis on the results from experimental and clinical studies that used cell therapy and tissue engineering as tools for optimizing the regeneration process. The articles used came from the LILACS, Medline and SciELO scientific databases. Articles on the use of stem cells, Schwann cells, growth factors, collagen, laminin and platelet-rich plasma for peripheral nerve repair were summarized over the course of the review. Based on these studies, it could be concluded that the use of stem cells derived from different sources presents promising results relating to nerve regeneration, because these cells have a capacity for neuronal differentiation, thus demonstrating effective functional results. The use of tubes containing bioactive elements with controlled release also optimizes the nerve repair, thus promoting greater myelination and axonal growth of peripheral nerves. Another promising treatment is the use of platelet-rich plasma, which not only releases growth factors that are important in nerve repair, but also serves as a carrier for exogenous factors, thereby stimulating the proliferation of specific cells for peripheral nerve repair. PMID:27027067

  13. Cartilage repair with autogenic perichondrium cell and polylactic acid grafts.

    PubMed

    Dounchis, J S; Bae, W C; Chen, A C; Sah, R L; Coutts, R D; Amiel, D

    2000-08-01

    The repair of articular cartilage injuries remains a challenge, with many of the current therapeutic strategies based on the grafting or recruitment of chondrogenic tissues or cells. This 1-year study compared the repair of a 3.7-mm diameter by 3-mm deep osteochondral defect in the medial femoral condyle of 24 New Zealand White rabbits; the defect was obtained using an autogenic perichondrium cell polylactic acid composite graft with a contralateral control in which the osteochondral defect remained empty. To elucidate the effect of host immune responses on the repair process after perichondrium cell transplantation, the results of the autogenic perichondrium cell polylactic acid graft group were compared with those obtained in the authors' previous 1-year study of allogenic perichondrium cell polylactic acid composite grafts implanted in a similar model. One year after surgery, the repair site underwent gross inspection and histologic, histomorphometric, biochemical, and biomechanical analyses. The autogenic perichondrium cell polylactic acid graft group (92%) and the control group in which the osteochondral defect remained empty (88%) resulted in a high percentage of grossly acceptable repairs. The autogenic grafts appeared to augment the intrinsic healing capacity of the animals (as compared with the animals in the No Implant Group). The autogenic perichondrium cell polylactic and grafts improved the histologic appearance and percentage of Type II collagen of the cartilaginous repair tissue. Compared with allogenic grafts, the autogenic grafts had better reconstitution of the subchondral bone. However, the results of this experimental model suggest a suboptimal concentration of glycosaminoglycans in the neocartilage matrix, a depressed surface of the repair tissue, a histologic appearance that was not equivalent to that of normal articular cartilage, and reduced biomechanical properties for the repair tissue. The future application of growth factors to this

  14. Cyclosporin in cell therapy for cardiac regeneration.

    PubMed

    Jansen Of Lorkeers, S J; Hart, E; Tang, X L; Chamuleau, M E D; Doevendans, P A; Bolli, R; Chamuleau, S A J

    2014-07-01

    Stem cell therapy is a promising strategy in promoting cardiac repair in the setting of ischemic heart disease. Clinical and preclinical studies have shown that cell therapy improves cardiac function. Whether autologous or allogeneic cells should be used, and the need for immunosuppression in non-autologous settings, is a matter of debate. Cyclosporin A (CsA) is frequently used in preclinical trials to reduce cell rejection after non-autologous cell therapy. The direct effect of CsA on the function and survival of stem cells is unclear. Furthermore, the appropriate daily dosage of CsA in animal models has not been established. In this review, we discuss the pros and cons of the use of CsA on an array of stem cells both in vitro and in vivo. Furthermore, we present a small collection of data put forth by our group supporting the efficacy and safety of a specific daily CsA dosage in a pig model.

  15. Gene, stem cell, and future therapies for orphan diseases.

    PubMed

    Phillips, M Ian

    2012-08-01

    There are an estimated 7,000 "orphan diseases," but treatments are currently available for only about 5% of them. Recent progress in the advanced platforms of gene therapy, stem cell therapy, gene modification, and gene correction offers possibilities for new therapies and cures for rare diseases. Many rare diseases are genetic in origin, and gene therapy is being successfully applied to treat them. Human stem cell therapy, apart from bone marrow transplants, is still experimental. Genetic modification of stem cells can make stem cell-based products more effective. Autologous induced pluripotent stem (iPS) cells, when combined with new classes of artificial nucleases, have great potential in the ex vivo repair of specific mutated DNA sequences (zinc-finger proteins and transactivator-like effector nucleases). Patient-specific iPS cells can be corrected and transplanted back into the patient. Stem cells secrete paracrine factors that could become new therapeutic tools in the treatment of orphan diseases. Gene therapy and stem cell therapy with DNA repair are promising approaches to the treatment of rare, intractable diseases.

  16. Brain necrosis after fractionated radiation therapy: Is the halftime for repair longer than we thought?

    SciTech Connect

    Bender, Edward T.

    2012-11-15

    Purpose: To derive a radiobiological model that enables the estimation of brain necrosis and spinal cord myelopathy rates for a variety of fractionation schemes, and to compare repair effects between brain and spinal cord. Methods: Sigmoidal dose response relationships for brain radiation necrosis and spinal cord myelopathy are derived from clinical data using nonlinear regression. Three different repair models are considered and the repair halftimes are included as regression parameters. Results: For radiation necrosis, a repair halftime of 38.1 (range 6.9-76) h is found with monoexponential repair, while for spinal cord myelopathy, a repair halftime of 4.1 (range 0-8) h is found. The best-fit alpha beta ratio is 0.96 (range 0.24-1.73)Conclusions: A radiobiological model that includes repair corrections can describe the clinical data for a variety of fraction sizes, fractionation schedules, and total doses. Modeling suggests a relatively long repair halftime for brain necrosis. This study suggests that the repair halftime for late radiation effects in the brain may be longer than is currently thought. If confirmed in future studies, this may lead to a re-evaluation of radiation fractionation schedules for some CNS diseases, particularly for those diseases where fractionated stereotactic radiation therapy is used.

  17. Stem cell transplantation therapy for multifaceted therapeutic benefits after stroke.

    PubMed

    Wei, Ling; Wei, Zheng Z; Jiang, Michael Qize; Mohamad, Osama; Yu, Shan Ping

    2017-03-18

    One of the exciting advances in modern medicine and life science is cell-based neurovascular regeneration of damaged brain tissues and repair of neuronal structures. The progress in stem cell biology and creation of adult induced pluripotent stem (iPS) cells has significantly improved basic and pre-clinical research in disease mechanisms and generated enthusiasm for potential applications in the treatment of central nervous system (CNS) diseases including stroke. Endogenous neural stem cells and cultured stem cells are capable of self-renewal and give rise to virtually all types of cells essential for the makeup of neuronal structures. Meanwhile, stem cells and neural progenitor cells are well-known for their potential for trophic support after transplantation into the ischemic brain. Thus, stem cell-based therapies provide an attractive future for protecting and repairing damaged brain tissues after injury and in various disease states. Moreover, basic research on naïve and differentiated stem cells including iPS cells has markedly improved our understanding of cellular and molecular mechanisms of neurological disorders, and provides a platform for the discovery of novel drug targets. The latest advances indicate that combinatorial approaches using cell based therapy with additional treatments such as protective reagents, preconditioning strategies and rehabilitation therapy can significantly improve therapeutic benefits. In this review, we will discuss the characteristics of cell therapy in different ischemic models and the application of stem cells and progenitor cells as regenerative medicine for the treatment of stroke.

  18. Concise review: limbal epithelial stem cell therapy: controversies and challenges.

    PubMed

    O'Callaghan, Anna R; Daniels, Julie T

    2011-12-01

    Limbal epithelial stem cells (LESCs) are a population of stem cells responsible for maintenance and repair of the corneal surface. Injury and disease can result in a deficiency of these stem cells, the vision affecting condition called limbal stem cell deficiency (LSCD) in which the cornea becomes opaque, vascularized, and inflamed. Cultured LESC therapy was first described in 1997;29:19231932-19231932.and LESCs cultured from either patients or donors have been used to successfully treat LSCD. In this review, some of the challenges and controversies associated with cultured LESC therapy will be discussed including alternative stem cell sources.

  19. Cell therapy of pseudarthrosis

    PubMed Central

    Bastos Filho, Ricardo; Lermontov, Simone; Borojevic, Radovan; Schott, Paulo Cezar; Gameiro, Vinicius Schott; Granjeiro, José Mauro

    2012-01-01

    Objective To assess the safety and efficiency of cell therapy for pseudarthrosis. Implant of the bone marrow aspirate was compared to mononuclear cells purified extemporaneously using the Sepax® equipment. Methods Six patients with nonunion of the tibia or femur were treated. Four received a percutaneous infusion of autologous bone marrow aspirated from the iliac crest, and two received autologous bone marrow mononuclear cells separated from the aspirate with the Sepax®. The primary fixation method was unchanged, and the nonunion focus was not exposed. Physical examination and radiographies were performed 2, 4 and 6 months after the treatment by the same physician. After consolidation of the fracture the satisfaction of the patients was estimated using the adapted QALY scale. Results No complications occurred as a result of the referred procedures. Bone consolidation was obtained in all cases within 3 to 24 weeks. The degree of patient satisfaction before and after bone consolidation was assessed, with the average value increasing from two to nine (p=0.0156). Conclusion We conclude that the proposed method is effective and safe for the treatment of nonunion of long bones regardless of the stabilization method used. Level of Evidence II, Prospective Comparative Study PMID:24453616

  20. Discovery of Novel Small Molecules that Activate Satellite Cell Proliferation and Enhance Repair of Damaged Muscle.

    PubMed

    Billin, Andrew N; Bantscheff, Marcus; Drewes, Gerard; Ghidelli-Disse, Sonja; Holt, Jason A; Kramer, Henning F; McDougal, Alan J; Smalley, Terry L; Wells, Carrow I; Zuercher, William J; Henke, Brad R

    2016-02-19

    Skeletal muscle progenitor stem cells (referred to as satellite cells) represent the primary pool of stem cells in adult skeletal muscle responsible for the generation of new skeletal muscle in response to injury. Satellite cells derived from aged muscle display a significant reduction in regenerative capacity to form functional muscle. This decrease in functional recovery has been attributed to a decrease in proliferative capacity of satellite cells. Hence, agents that enhance the proliferative abilities of satellite cells may hold promise as therapies for a variety of pathological settings, including repair of injured muscle and age- or disease-associated muscle wasting. Through phenotypic screening of isolated murine satellite cells, we identified a series of 2,4-diaminopyrimidines (e.g., 2) that increased satellite cell proliferation. Importantly, compound 2 was effective in accelerating repair of damaged skeletal muscle in an in vivo mouse model of skeletal muscle injury. While these compounds were originally prepared as c-Jun N-terminal kinase 1 (JNK-1) inhibitors, structure-activity analyses indicated JNK-1 inhibition does not correlate with satellite cell activity. Screening against a broad panel of kinases did not result in identification of an obvious molecular target, so we conducted cell-based proteomics experiments in an attempt to identify the molecular target(s) responsible for the potentiation of the satellite cell proliferation. These data provide the foundation for future efforts to design improved small molecules as potential therapeutics for muscle repair and regeneration.

  1. Effects of Lubricant and Autologous Bone Marrow Stromal Cell Augmentation on Immobilized Flexor Tendon Repairs

    PubMed Central

    Zhao, Chunfeng; Ozasa, Yasuhiro; Shimura, Haruhiko; Reisdorf, Ramona L.; Thoreson, Andrew R.; Jay, Gregory; Moran, Steven L.; An, Kai-Nan; Amadio, Peter C.

    2016-01-01

    The purpose of the study was to test a novel treatment that carbodiimide-derivatized-hyaluronic acid-lubricin (cd-HA-lubricin) combined cell-based therapy in an immobilized flexor tendon repair in a canine model. Seventy-eight flexor tendons from 39 dogs were transected. One tendon was treated with cd-HA-lubricin plus an interpositional graft of 8 × 105 BMSCs and GDF-5. The other tendon was repaired without treatment. After 21 day of immobilization, 19 dogs were sacrificed; the remaining 20 dogs underwent a 21-day rehabilitation protocol before euthanasia. The work of flexion, tendon gliding resistance, and adhesion score in treated tendons were significantly less than the untreated tendons (p < 0.05). The failure strength of the untreated tendons was higher than the treated tendons at 21 and 42 days (p < 0.05). However, there is no significant difference in stiffness between two groups at day 42. Histologic analysis of treated tendons showed a smooth surface and viable transplanted cells 42 days after the repair, whereas untreated tendons showed severe adhesion formation around the repair site. The combination of lubricant and cell treatment resulted in significantly improved digit function, reduced adhesion formation. This novel treatment can address the unmet needs of patients who are unable to commence an early mobilization protocol after flexor tendon repair. PMID:26177854

  2. Human spermatagonial stem cells: a novel therapeutic hope for cardiac regeneration and repair?

    PubMed

    Guan, Kaomei; Cheng, I-Fen; Baazm, Maryam

    2012-01-01

    Although the identification and characterization of human spermatogonial stem cells was reported nearly 50 years ago, great progress has been made only in the last few years. Spermatogonial stem cells attract a great deal of researchers' attention because of their unique characteristics, including the ability to be converted spontaneously into pluripotent germline stem cells with embryonic stem cell-like properties. Pluripotent stem cells are able to differentiate into any desired cell type in the body; therefore, they are the most promising cell source for organ regeneration. The advantages of pluripotent germline stem cells over other stem cells are that they maintain a high degree of DNA integrity and can resolve some ethical and immunological problems related to human embryonic stem cells. In this article we address the origin, characteristics and pluripotency of spermatogonial stem cells. Their contribution to stem cell-based organ regeneration therapy with special emphasis on cardiac regeneration and repair in the future is also discussed.

  3. Cell therapy for the degenerating intervertebral disc.

    PubMed

    Tong, Wei; Lu, Zhouyu; Qin, Ling; Mauck, Robert L; Smith, Harvey E; Smith, Lachlan J; Malhotra, Neil R; Heyworth, Martin F; Caldera, Franklin; Enomoto-Iwamoto, Motomi; Zhang, Yejia

    2017-03-01

    Spinal conditions related to intervertebral disc (IVD) degeneration cost billions of dollars in the US annually. Despite the prevalence and soaring cost, there is no specific treatment that restores the physiological function of the diseased IVD. Thus, it is vital to develop new treatment strategies to repair the degenerating IVD. Persons with IVD degeneration without back pain or radicular leg pain often do not require any intervention. Only patients with severe back pain related to the IVD degeneration or biomechanical instability are likely candidates for cell therapy. The IVD progressively degenerates with age in humans, and strategies to repair the IVD depend on the stage of degeneration. Cell therapy and cell-based gene therapy aim to address moderate disc degeneration; advanced stage disease may require surgery. Studies involving autologous, allogeneic, and xenogeneic cells have all shown good survival of these cells in the IVD, confirming that the disc niche is an immunologically privileged site, permitting long-term survival of transplanted cells. All of the animal studies reviewed here reported some improvement in disc structure, and 2 studies showed attenuation of local inflammation. Among the 50 studies reviewed, 25 used some type of scaffold, and cell leakage is a consistently noted problem, though some studies showed reduced cell leakage. Hydrogel scaffolds may prevent cell leakage and provide biomechanical support until cells can become established matrix producers. However, these gels need to be optimized to prevent this leakage. Many animal models have been leveraged in this research space. Rabbit is the most frequently used model (28 of 50), followed by rat, pig, and dog. Sheep and goat IVDs resemble those of humans in size and in the absence of notochordal cells. Despite this advantage, there were only 2 sheep and 1 goat studies of 50 studies in this cohort. It is also unclear if a study in large animals is needed before clinical trials since

  4. Embryonic stem cells in cardiac repair and regeneration.

    PubMed

    Singla, Dinender K

    2009-08-01

    Cell transplantation is a subject of fast-growing research with a potential of a therapeutic approach for the treatment of heart diseases. Clinical applications require preparation of large number of donor cells. Stem cell studies published to date demonstrate that scientists have not reached the general consensus to use an optimal cell type for better cardiac repair and regeneration. We used embryonic stem (ES) cells and their released factors for cardiac repair and regeneration. The major concern of cardiac regeneration with stem cells includes engraftment, differentiation, and teratoma formation after ES cell transplantation. Our current knowledge of ES cell transplantation in the heart is very limited. This review discusses the use of various growth factors to enhance ES cells engraftment and differentiation, as well as the issue of teratoma formation.

  5. DNA repair mechanisms in dividing and non-dividing cells.

    PubMed

    Iyama, Teruaki; Wilson, David M

    2013-08-01

    DNA damage created by endogenous or exogenous genotoxic agents can exist in multiple forms, and if allowed to persist, can promote genome instability and directly lead to various human diseases, particularly cancer, neurological abnormalities, immunodeficiency and premature aging. To avoid such deleterious outcomes, cells have evolved an array of DNA repair pathways, which carry out what is typically a multiple-step process to resolve specific DNA lesions and maintain genome integrity. To fully appreciate the biological contributions of the different DNA repair systems, one must keep in mind the cellular context within which they operate. For example, the human body is composed of non-dividing and dividing cell types, including, in the brain, neurons and glial cells. We describe herein the molecular mechanisms of the different DNA repair pathways, and review their roles in non-dividing and dividing cells, with an eye toward how these pathways may regulate the development of neurological disease.

  6. DNA repair mechanisms in dividing and non-dividing cells

    PubMed Central

    Iyama, Teruaki; Wilson, David M.

    2013-01-01

    DNA damage created by endogenous or exogenous genotoxic agents can exist in multiple forms, and if allowed to persist, can promote genome instability and directly lead to various human diseases, particularly cancer, neurological abnormalities, immunodeficiency and premature aging. To avoid such deleterious outcomes, cells have evolved an array of DNA repair pathways, which carry out what is typically a multiple-step process to resolve specific DNA lesions and maintain genome integrity. To fully appreciate the biological contributions of the different DNA repair systems, one must keep in mind the cellular context within they operate. For example, the human body is composed of non-dividing and dividing cell types, including, in the brain, neurons and glial cells. We describe herein the molecular mechanisms of the different DNA repair pathways, and review their roles in non-dividing and dividing cells, with an eye towards how these pathways may regulate the development of neurological disease. PMID:23684800

  7. Harmine suppresses homologous recombination repair and inhibits proliferation of hepatoma cells

    PubMed Central

    Zhang, Lei; Zhang, Fan; Zhang, Wenjun; Chen, Lu; Gao, Neng; Men, Yulong; Xu, Xiaojun; Jiang, Ying

    2015-01-01

    To avoid cell cycle arrest or apoptosis, rapidly proliferating cancer cells have to promote DNA double strand break (DSB) repair to fix replication stress induced DSBs. Therefore, developing drugs blocking homologous recombination (HR) and nonhomologous end joining (NHEJ) – 2 major DSB repair pathways – holds great potential for cancer therapy. Over the last few decades, much attention has been paid to explore drugs targeting DSB repair pathways for cancer therapy. Here, using 2 well-established reporters for analyzing HR and NHEJ efficiency, we found that both HR and NHEJ are elevated in hepatoma cell lines Hep3B and HuH7 compared with normal liver cell lines Chang liver and QSG-7701. Our further study found that Harmine, a natural compound, negatively regulates HR but not NHEJ by interfering Rad51 recruitment, resulting in severe cytotoxicity in hepatoma cells. Furthermore, NHEJ inhibitor Nu7441 markedly sensitizes Hep3B cells to the anti-proliferative effects of Harmine. Taken together, our study suggested that Harmine holds great promise as an oncologic drug and combination of Harmine with a NHEJ inhibitor might be an effective strategy for anti-cancer treatment. PMID:26382920

  8. Suppressed expression of non-DSB repair genes inhibits gamma-radiation-induced cytogenetic repair and cell cycle arrest.

    PubMed

    Zhang, Ye; Rohde, Larry H; Emami, Kamal; Hammond, Dianne; Casey, Rachael; Mehta, Satish K; Jeevarajan, Antony S; Pierson, Duane L; Wu, Honglu

    2008-11-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in double-strand break (DSB) repair, and its impact on cytogenetic responses has not been well studied. The purpose of this study is to identify new roles of IR inducible genes in regulating DSB repair and cell cycle progression. In this study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by small interfering RNA in human fibroblast cells. Frequency of micronuclei (MN) formation and chromosome aberrations were measured to determine efficiency of cytogenetic repair, especially DSB repair. In response to IR, the formation of MN was significantly increased by suppressed expression of five genes: Ku70 (DSB repair pathway), XPA (nucleotide excision repair pathway), RPA1 (mismatch repair pathway), RAD17 and RBBP8 (cell cycle control). Knocked-down expression of four genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Moreover, decreased XPA, p21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Nine of these eleven genes, whose knock-down expression affected cytogenetic repair, were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate IR-induced biological consequences. Furthermore, eight non-DBS repair genes showed involvement in regulating DSB repair, indicating that

  9. Cartilage repair using human embryonic stem cell-derived chondroprogenitors.

    PubMed

    Cheng, Aixin; Kapacee, Zoher; Peng, Jiang; Lu, Shibi; Lucas, Robert J; Hardingham, Timothy E; Kimber, Susan J

    2014-11-01

    In initial work, we developed a 14-day culture protocol under potential GMP, chemically defined conditions to generate chondroprogenitors from human embryonic stem cells (hESCs). The present study was undertaken to investigate the cartilage repair capacity of these cells. The chondrogenic protocol was optimized and validated with gene expression profiling. The protocol was also applied successfully to two lines of induced pluripotent stem cells (iPSCs). Chondrogenic cells derived from hESCs were encapsulated in fibrin gel and implanted in osteochondral defects in the patella groove of nude rats, and cartilage repair was evaluated by histomorphology and immunocytochemistry. Genes associated with chondrogenesis were upregulated during the protocol, and pluripotency-related genes were downregulated. Aggregation of chondrogenic cells was accompanied by high expression of SOX9 and strong staining with Safranin O. Culture with PluriSln1 was lethal for hESCs but was tolerated by hESC chondrogenic cells, and no OCT4-positive cells were detected in hESC chondrogenic cells. iPSCs were also shown to generate chondroprogenitors in this protocol. Repaired tissue in the defect area implanted with hESC-derived chondrogenic cells was stained for collagen II with little collagen I, but negligible collagen II was observed in the fibrin-only controls. Viable human cells were detected in the repair tissue at 12 weeks. The results show that chondrogenic cells derived from hESCs, using a chemically defined culture system, when implanted in focal defects were able to promote cartilage repair. This is a first step in evaluating these cells for clinical application for the treatment of cartilage lesions.

  10. Tripartite meeting in gene and cell therapy, 2008: Irish Society for Gene and Cell Therapy, British Society for Gene Therapy, and International Society for Cell and Gene Therapy of Cancer.

    PubMed

    Guinn, Barbara; Casey, Garrett; Collins, Sara; O'Brien, Tim; Alexander, M Yvonne; Tangney, Mark

    2008-10-01

    The second annual meeting of the Irish Society for Gene and Cell Therapy was held in Cork, Ireland on May 15 and 16, 2008 (http://crr.ucc.ie/isgct/). The meeting was jointly organized with the British Society for Gene Therapy and the International Society for Cell and Gene Therapy of Cancer. Because of the location of the conference and the co-organization of this meeting with the British and International Gene Therapy societies, the meeting enjoyed a range of talks from some of the major leaders in the field. Particularly notable were the talented molecular and cell biologists from Ireland who have contributed cutting edge science to the field of gene therapy. Topics including cardiovascular disease, repair of single-gene disorders, and cancer gene therapy were discussed with presentations ranging from basic research to translation into the clinic. Here we describe some of the most exciting presentations and their potential impact on imminent clinical gene therapy trials.

  11. Stem Cell Therapy for the Inner Ear

    PubMed Central

    Okano, Takayuki

    2012-01-01

    In vertebrates, perception of sound, motion, and balance is mediated through mechanosensory hair cells located within the inner ear. In mammals, hair cells are only generated during a short period of embryonic development. As a result, loss of hair cells as a consequence of injury, disease, or genetic mutation, leads to permanent sensory deficits. At present, cochlear implantation is the only option for profound hearing loss. However, outcomes are still variable and even the best implant cannot provide the acuity of a biological ear. The recent emergence of stem cell technology has the potential to open new approaches for hair cell regeneration. The goal of this review is to summarize the current state of inner ear stem cell research from a viewpoint of its clinical application for inner ear disorders to illustrate how complementary studies have the potential to promote and refine stem cell therapies for inner ear diseases. The review initially discusses our current understanding of the genetic pathways that regulate hair cell formation from inner ear progenitors during normal development. Subsequent sections discuss the possible use of endogenous inner ear stem cells to induce repair as well as the initial studies aimed at transplanting stem cells into the ear. PMID:22514095

  12. Molecular Imaging in Stem Cell Therapy for Spinal Cord Injury

    PubMed Central

    Tian, Mei; Zhang, Hong

    2014-01-01

    Spinal cord injury (SCI) is a serious disease of the center nervous system (CNS). It is a devastating injury with sudden loss of motor, sensory, and autonomic function distal to the level of trauma and produces great personal and societal costs. Currently, there are no remarkable effective therapies for the treatment of SCI. Compared to traditional treatment methods, stem cell transplantation therapy holds potential for repair and functional plasticity after SCI. However, the mechanism of stem cell therapy for SCI remains largely unknown and obscure partly due to the lack of efficient stem cell trafficking methods. Molecular imaging technology including positron emission tomography (PET), magnetic resonance imaging (MRI), optical imaging (i.e., bioluminescence imaging (BLI)) gives the hope to complete the knowledge concerning basic stem cell biology survival, migration, differentiation, and integration in real time when transplanted into damaged spinal cord. In this paper, we mainly review the molecular imaging technology in stem cell therapy for SCI. PMID:24701583

  13. The potential therapeutic use of stem cells in cartilage repair.

    PubMed

    Perera, Jonathan R; Jaiswal, Parag K; Khan, Wasim S

    2012-03-01

    As our population demographics change, osteoarthritis and cartilage defects are becoming more prevalent. The discovery of stems cells and their ability for indefinite regeneration has revolutionised the way cartilage problems are viewed. Tissue engineering has been shown to be the ideal way of repairing articular cartilage lesions, i.e. back to native tissue. Cartilage is an ideal tissue engineering target as it is avascular, aneural and alymphatic. The two main types of stem cells being investigated in chondrogenesis are embryological and mesenchymal stem cells. Research into embryological stem cells has been surrounded by controversy because of ethical, religious and social concerns. We discuss the use of embryological and mesenchymal stem cells in cartilage repair and the various factors involved in the differentiation into chondrocytes. We also discuss commonly used mesenchymal stem cell markers and their limitations.

  14. Embryonic versus mesenchymal stem cells in cartilage repair.

    PubMed

    Perera, Jonathan R; Jaiswal, Parag K; Khan, Wasim S; Adesida, Adetola

    2012-01-01

    As our population changes osteoarthritis and cartilage defects are becoming more prevalent. The discovery of stems cells and their ability for indefinite regeneration has revolutionised the way cartilage problems are viewed. Tissue engineering has been shown to be the ideal way of repairing articular cartilage lesions, i.e. back to native tissue. The two main types of stem cells being investigated in chondrogenesis are embryological and mesenchymal stem cells. Research into embryological stem cells has been surrounded by controversy because of tumour formation and damaging embryos during the harvest of cells. We discuss the use of embryological and mesenchymal stem cells in cartilage repair and the various factors involved in the differentiation into chondrocytes.

  15. Strategies to Optimize Adult Stem Cell Therapy for Tissue Regeneration.

    PubMed

    Liu, Shan; Zhou, Jingli; Zhang, Xuan; Liu, Yang; Chen, Jin; Hu, Bo; Song, Jinlin; Zhang, Yuanyuan

    2016-06-21

    Stem cell therapy aims to replace damaged or aged cells with healthy functioning cells in congenital defects, tissue injuries, autoimmune disorders, and neurogenic degenerative diseases. Among various types of stem cells, adult stem cells (i.e., tissue-specific stem cells) commit to becoming the functional cells from their tissue of origin. These cells are the most commonly used in cell-based therapy since they do not confer risk of teratomas, do not require fetal stem cell maneuvers and thus are free of ethical concerns, and they confer low immunogenicity (even if allogenous). The goal of this review is to summarize the current state of the art and advances in using stem cell therapy for tissue repair in solid organs. Here we address key factors in cell preparation, such as the source of adult stem cells, optimal cell types for implantation (universal mesenchymal stem cells vs. tissue-specific stem cells, or induced vs. non-induced stem cells), early or late passages of stem cells, stem cells with endogenous or exogenous growth factors, preconditioning of stem cells (hypoxia, growth factors, or conditioned medium), using various controlled release systems to deliver growth factors with hydrogels or microspheres to provide apposite interactions of stem cells and their niche. We also review several approaches of cell delivery that affect the outcomes of cell therapy, including the appropriate routes of cell administration (systemic, intravenous, or intraperitoneal vs. local administration), timing for cell therapy (immediate vs. a few days after injury), single injection of a large number of cells vs. multiple smaller injections, a single site for injection vs. multiple sites and use of rodents vs. larger animal models. Future directions of stem cell-based therapies are also discussed to guide potential clinical applications.

  16. Strategies to Optimize Adult Stem Cell Therapy for Tissue Regeneration

    PubMed Central

    Liu, Shan; Zhou, Jingli; Zhang, Xuan; Liu, Yang; Chen, Jin; Hu, Bo; Song, Jinlin; Zhang, Yuanyuan

    2016-01-01

    Stem cell therapy aims to replace damaged or aged cells with healthy functioning cells in congenital defects, tissue injuries, autoimmune disorders, and neurogenic degenerative diseases. Among various types of stem cells, adult stem cells (i.e., tissue-specific stem cells) commit to becoming the functional cells from their tissue of origin. These cells are the most commonly used in cell-based therapy since they do not confer risk of teratomas, do not require fetal stem cell maneuvers and thus are free of ethical concerns, and they confer low immunogenicity (even if allogenous). The goal of this review is to summarize the current state of the art and advances in using stem cell therapy for tissue repair in solid organs. Here we address key factors in cell preparation, such as the source of adult stem cells, optimal cell types for implantation (universal mesenchymal stem cells vs. tissue-specific stem cells, or induced vs. non-induced stem cells), early or late passages of stem cells, stem cells with endogenous or exogenous growth factors, preconditioning of stem cells (hypoxia, growth factors, or conditioned medium), using various controlled release systems to deliver growth factors with hydrogels or microspheres to provide apposite interactions of stem cells and their niche. We also review several approaches of cell delivery that affect the outcomes of cell therapy, including the appropriate routes of cell administration (systemic, intravenous, or intraperitoneal vs. local administration), timing for cell therapy (immediate vs. a few days after injury), single injection of a large number of cells vs. multiple smaller injections, a single site for injection vs. multiple sites and use of rodents vs. larger animal models. Future directions of stem cell-based therapies are also discussed to guide potential clinical applications. PMID:27338364

  17. Mesenchymal stem cell-loaded cardiac patch promotes epicardial activation and repair of the infarcted myocardium.

    PubMed

    Wang, Qiang-Li; Wang, Hai-Jie; Li, Zhi-Hua; Wang, Yong-Li; Wu, Xue-Ping; Tan, Yu-Zhen

    2017-02-28

    Cardiac patch is considered a promising strategy for enhancing stem cell therapy of myocardial infarction (MI). However, the underlying mechanisms for cardiac patch repairing infarcted myocardium remain unclear. In this study, we investigated the mechanisms of PCL/gelatin patch loaded with MSCs on activating endogenous cardiac repair. PCL/gelatin patch was fabricated by electrospun. The patch enhanced the survival of the seeded MSCs and their HIF-1α, Tβ4, VEGF and SDF-1 expression and decreased CXCL14 expression in hypoxic and serum-deprived conditions. In murine MI models, the survival and distribution of the engrafted MSCs and the activation of the epicardium were examined, respectively. At 4 weeks after transplantation of the cell patch, the cardiac functions were significantly improved. The engrafted MSCs migrated across the epicardium and into the myocardium. Tendency of HIF-1α, Tβ4, VEGF, SDF-1 and CXCL14 expression in the infarcted myocardium was similar with expression in vitro. The epicardium was activated and epicardial-derived cells (EPDCs) migrated into deep tissue. The EPDCs differentiated into endothelial cells and smooth muscle cells, and some of EPDCs showed to have differentiated into cardiomyocytes. Density of blood and lymphatic capillaries increased significantly. More c-kit(+) cells were recruited into the infarcted myocardium after transplantation of the cell patch. The results suggest that epicardial transplantation of the cell patch promotes repair of the infarcted myocardium and improves cardiac functions by enhancing the survival of the transplanted cells, accelerating locality paracrine, and then activating the epicardium and recruiting endogenous c-kit(+) cells. Epicardial transplantation of the cell patch may be applied as a novel effective MI therapy.

  18. Compression therapy promotes proliferative repair during rat Achilles tendon immobilization.

    PubMed

    Schizas, Nikos; Li, Jian; Andersson, Therese; Fahlgren, Anna; Aspenberg, Per; Ahmed, Mahmood; Ackermann, Paul W

    2010-07-01

    Achilles tendon ruptures are treated with an initial period of immobilization, which obstructs the healing process partly by a reduction of blood circulation. Intermittent pneumatic compression (IPC) has been proposed to enhance tendon repair by stimulation of blood flow. We hypothesized that daily IPC treatment can counteract the deficits caused by 2 weeks of immobilization post tendon rupture. Forty-eight Sprague-Dawley SD) rats, all subjected to blunt Achilles tendon transection, were divided in three equal groups. Group A was allowed free cage activity, whereas groups B-C were immobilized at the operated hindleg. Group C received daily IPC treatment. Two weeks postrupture the rats were euthanatized and the tendons analyzed with tensile testing and histological assessments of collagen organization and collagen III-LI occurrence. Immobilization significantly reduced maximum force, energy uptake, stiffness, tendon length, transverse area, stress, organized collagen diameter and collagen III-LI occurrence by respectively 80, 75, 77, 22, 47, 65, 49, and 83% compared to free mobilization. IPC treatment improved maximum force 65%, energy 168%, organized collagen diameter 50%, tendon length 25%, and collagen III-LI occurrence 150% compared to immobilization only. The results confirm that immobilization impairs healing after tendon rupture and furthermore demonstrate that IPC-treatment can enhance proliferative tendon repair by counteracting biomechanical and morphological deficits caused by immobilization.

  19. [Inner ear cell therapy for hereditary deafness with multipotent stem cells].

    PubMed

    Kamiya, Kazusaku; Ikeda, Katsuhisa

    2011-12-01

    Congenital deafness affects about 1 in 1000 children and the half of them have genetic background such as connexin26 gene mutation. The strategy to rescue such hereditary deafness has not been developed yet. Inner ear cell therapy for hereditary deafness has been studied using some laboratory animals and multipotent stem cells, although the successful reports for the hearing recovery accompanied with supplementation of the normal functional cells followed by tissue repair and recovery of the cellular/molecular functions have been still few. To succeed in hearing recovery by inner ear cell therapy, appropriate cell type, surgical approach and the stem cell homing system to the niche are thought to be required.

  20. Medicinal Leech Therapy for Glans Penis Congestion After Primary Bladder Exstrophy-Epispadias Repair in an Infant: A Case Report.

    PubMed

    Wagenheim, Gavin N; Au, Jason; Gargollo, Patricio C

    2016-01-01

    Many postoperative complications have been reported after repair of classic bladder exstrophy. We present a case of medicinal leech therapy for glans penis congestion following exstrophy repair in an infant. A 2-week-old male with classic bladder exstrophy underwent complete primary repair. On postoperative day 1, he developed rapidly worsening glans penis venous congestion. Medicinal leech therapy was instituted with antibiotics and blood transfusions to maintain a hematocrit >30%. After 24 hours, venous congestion improved and therapy was discontinued. The patient's remaining hospital course was uncomplicated. Medicinal leeches are an effective therapy to relieve glans penis venous congestion.

  1. Stem cells of the suture mesenchyme in craniofacial bone development, repair and regeneration

    PubMed Central

    Maruyama, Takamitsu; Jeong, Jaeim; Sheu, Tzong-Jen; Hsu, Wei

    2016-01-01

    The suture mesenchyme serves as a growth centre for calvarial morphogenesis and has been postulated to act as the niche for skeletal stem cells. Aberrant gene regulation causes suture dysmorphogenesis resulting in craniosynostosis, one of the most common craniofacial deformities. Owing to various limitations, especially the lack of suture stem cell isolation, reconstruction of large craniofacial bone defects remains highly challenging. Here we provide the first evidence for an Axin2-expressing stem cell population with long-term self-renewing, clonal expanding and differentiating abilities during calvarial development and homeostastic maintenance. These cells, which reside in the suture midline, contribute directly to injury repair and skeletal regeneration in a cell autonomous fashion. Our findings demonstrate their true identity as skeletal stem cells with innate capacities to replace the damaged skeleton in cell-based therapy, and permit further elucidation of the stem cell-mediated craniofacial skeletogenesis, leading to revealing the complex nature of congenital disease and regenerative medicine. PMID:26830436

  2. Pituitary cell differentiation from stem cells and other cells: toward restorative therapy for hypopituitarism?

    PubMed

    Willems, Christophe; Vankelecom, Hugo

    2014-01-01

    The pituitary gland, key regulator of our endocrine system, produces multiple hormones that steer essential physiological processes. Hence, deficient pituitary function (hypopituitarism) leads to severe disorders. Hypopituitarism can be caused by defective embryonic development, or by damage through tumor growth/resection and traumatic brain injury. Lifelong hormone replacement is needed but associated with significant side effects. It would be more desirable to restore pituitary tissue and function. Recently, we showed that the adult (mouse) pituitary holds regenerative capacity in which local stem cells are involved. Repair of deficient pituitary may therefore be achieved by activating these resident stem cells. Alternatively, pituitary dysfunction may be mended by cell (replacement) therapy. The hormonal cells to be transplanted could be obtained by (trans-)differentiating various kinds of stem cells or other cells. Here, we summarize the studies on pituitary cell regeneration and on (trans-)differentiation toward hormonal cells, and speculate on restorative therapies for pituitary deficiency.

  3. [Cell therapy for Parkinson disease].

    PubMed

    Muramatsu, Shin-ichi

    2009-11-01

    Advances in the field of stem cell research have raised hopes of creating novel cell replacement therapies for Parkinson disease (PD), although double-blinded clinical trials have met with controversial success in patients implanted with fetal midbrain tissue and autopsy results have shown that some of the grafted fetal neurons displayed pathological changes typical of PD. Dopaminergic neurons have been efficiently derived from stem cells using various methods, and beneficial effects after transplantation have been demonstrated in animal models of PD. Some obstacles remain to be overcome before stem cell therapy can be routinely and safely used to treat PD in humans. A widely used prodrug/suicide gene therapy would be applied to stem cells to reduce risk of tumor formation. Since grafts were transplanted ectopically into the striatum instead of the substantia nigra in most current protocols, surviving dopaminergic neurons would not have to be the same subtype as the nigral cells. If the main mechanism underlying any functional recovery achieved by cell therapies is restoration of dopaminergic neurotransmission, then viral vector-mediated gene delivery of dopamine-synthesizing enzymes represents a more straightforward approach. Future targets for cell therapy should include some types of Parkinsonism with degeneration of striatal neurons.

  4. Cardiac progenitor cells and bone marrow-derived very small embryonic-like stem cells for cardiac repair after myocardial infarction.

    PubMed

    Tang, Xian-Liang; Rokosh, D Gregg; Guo, Yiru; Bolli, Roberto

    2010-03-01

    Heart failure after myocardial infarction (MI) continues to be the most prevalent cause of morbidity and mortality worldwide. Although pharmaceutical agents and interventional strategies have contributed greatly to therapy, new and superior treatment modalities are urgently needed given the overall disease burden. Stem cell-based therapy is potentially a promising strategy to lead to cardiac repair after MI. An array of cell types has been explored in this respect, including skeletal myoblasts, bone marrow (BM)-derived stem cells, embryonic stem cells, and more recently, cardiac progenitor cells (CPCs). Recently studies have obtained evidence that transplantation of CPCs or BM-derived very small embryonic-like stem cells can improve cardiac function and alleviate cardiac remodeling, supporting the potential therapeutic utility of these cells for cardiac repair. This report summarizes the current data from those studies and discusses the potential implication of these cells in developing clinically-relevant stem cell-based therapeutic strategies for cardiac regeneration.

  5. Functional repair of p53 mutation in colorectal cancer cells using trans-splicing.

    PubMed

    He, Xingxing; Liao, Jiazhi; Liu, Fang; Yan, Junwei; Yan, Jingjun; Shang, Haitao; Dou, Qian; Chang, Ying; Lin, Jusheng; Song, Yuhu

    2015-02-10

    Mutation in the p53 gene is arguably the most frequent type of gene-specific alterations in human cancers. Current p53-based gene therapy contains the administration of wt-p53 or the suppression of mutant p53 expression in p53-defective cancer cells. . We hypothesized that trans-splicing could be exploited as a tool for the correction of mutant p53 transcripts in p53-mutated human colorectal cancer (CRC) cells. In this study, the plasmids encoding p53 pre-trans-splicing molecules (PTM) were transfected into human CRC cells carrying p53 mutation. The plasmids carrying p53-PTM repaired mutant p53 transcripts in p53-mutated CRC cells, which resulted in a reduction in mutant p53 transcripts and an induction of wt-p53 simultaneously. Intratumoral administration of adenovirus vectors carrying p53 trans-splicing cassettes suppressed the growth of tumor xenografts. Repair of mutant p53 transcripts by trans-splicing induced cell-cycle arrest and apoptosis in p53-defective colorectal cancer cells in vitro and in vivo. In conclusion, the present study demonstrated for the first time that trans-splicing was exploited as a strategy for the repair of mutant p53 transcripts, which revealed that trans-splicing would be developed as a new therapeutic approach for human colorectal cancers carrying p53 mutation.

  6. Signaling factors in stem cell-mediated repair of infarcted myocardium.

    PubMed

    Vandervelde, S; van Luyn, M J A; Tio, R A; Harmsen, M C

    2005-08-01

    Myocardial infarction leads to scar formation and subsequent reduced cardiac performance. The ultimate therapy after myocardial infarction would pursue stem cell-based regeneration. The aim of stem cell-mediated cardiac repair embodies restoration of cardiac function by regeneration of healthy myocardial tissue, which is accomplished by neo-angiogenesis and cardiogenesis. A major reservoir of adult autologous stem cells distal from the heart is the bone marrow. Adequate regulation of signaling between the bone marrow, the peripheral circulation and the infarcted myocardium is important in orchestrating the process of mobilization, homing, incorporation, survival, proliferation and differentiation of stem cells, that leads to myocardial regeneration. In this review, we discuss key signaling factors, including cytokines, chemokines and growth factors, which are involved in orchestrating the stem cell driven repair process. We focus on signaling factors known for their mobilizing and chemotactic abilities (SDF-1, G-CSF, SCF, IL-8, VEGF), signaling factors that are expressed after myocardial infarction involved in the patho-physiological healing process (TNF-alpha, IL-8, IL-10, HIF-1alpha, VEGF, G-CSF) and signaling factors that are involved in cardiogenesis and neo-angiogenesis (VEGF, EPO, TGF-beta, HGF, HIF-1alpha, IL-8). The future therapeutic application and capacity of secreted factors to modulate tissue repair after myocardial infarction relies on the intrinsic potency of factors and on the optimal localization and timing of a combination of signaling factors to stimulate stem cells in their niche to regenerate the infarcted heart.

  7. Bone marrow-derived cells homing for self-repair of periodontal tissues: a histological characterization and expression analysis.

    PubMed

    Wang, Yan; Zhou, Lili; Li, Chen; Xie, Han; Lu, Yuwang; Wu, Ying; Liu, Hongwei

    2015-01-01

    Periodontitis, a disease leads to the formation of periodontal defect, can result in tooth loss if left untreated. The therapies to repair/regenerate periodontal tissues have attracted lots of attention these years. Bone marrow-derived cells (BMDCs), a group of cells containing heterogeneous stem/progenitor cells, are capable of homing to injured tissues and participating in tissue repair/regeneration. The amplification of autologous BMDCs' potential in homing for self-repair/regeneration, therefore, might be considered as an alternative therapy except for traditional cell transplantation. However, the knowledge of the BMDCs' homing and participation in periodontal repair/regeneration is still known little. For the purpose of directly observing BMDCs' involvement in periodontal repair, chimeric mouse models were established to make their bone marrow cells reconstituted with cells expressing green enhanced fluorescence protein (EGFP) in this study. One month after bone marrow transplantation, periodontal defects were made on the mesial side of bilateral maxillary first molars in chimeric mice. The green fluorescence protein-positive (GFP+) BMDCS in periodontal defect regions were examined by bioluminescent imaging and immunofluorescence staining. GFP+ BMDCs were found to aggregate in the periodontal defect regions and emerge in newly-formed bones or fibers. Some of them also co-expressed markers of fibroblasts, osteoblasts or vascular endothelial cells. These results indicated that BMDCs might contribute to the formation of new fibers, bones and blood vessels during periodontal repair. In conclusion, we speculated that autologous BMDCs were capable of negotiating into the surgical sites created by periodontal operation and participating in tissue repair.

  8. Bone marrow-derived cells homing for self-repair of periodontal tissues: a histological characterization and expression analysis

    PubMed Central

    Wang, Yan; Zhou, Lili; Li, Chen; Xie, Han; Lu, Yuwang; Wu, Ying; Liu, Hongwei

    2015-01-01

    Periodontitis, a disease leads to the formation of periodontal defect, can result in tooth loss if left untreated. The therapies to repair/regenerate periodontal tissues have attracted lots of attention these years. Bone marrow-derived cells (BMDCs), a group of cells containing heterogeneous stem/progenitor cells, are capable of homing to injured tissues and participating in tissue repair/regeneration. The amplification of autologous BMDCs’ potential in homing for self-repair/regeneration, therefore, might be considered as an alternative therapy except for traditional cell transplantation. However, the knowledge of the BMDCs’ homing and participation in periodontal repair/regeneration is still known little. For the purpose of directly observing BMDCs’ involvement in periodontal repair, chimeric mouse models were established to make their bone marrow cells reconstituted with cells expressing green enhanced fluorescence protein (EGFP) in this study. One month after bone marrow transplantation, periodontal defects were made on the mesial side of bilateral maxillary first molars in chimeric mice. The green fluorescence protein-positive (GFP+) BMDCS in periodontal defect regions were examined by bioluminescent imaging and immunofluorescence staining. GFP+ BMDCs were found to aggregate in the periodontal defect regions and emerge in newly-formed bones or fibers. Some of them also co-expressed markers of fibroblasts, osteoblasts or vascular endothelial cells. These results indicated that BMDCs might contribute to the formation of new fibers, bones and blood vessels during periodontal repair. In conclusion, we speculated that autologous BMDCs were capable of negotiating into the surgical sites created by periodontal operation and participating in tissue repair. PMID:26722424

  9. Cancer Stem Cells: Repair Gone Awry?

    PubMed Central

    Rangwala, Fatima; Omenetti, Alessia; Diehl, Anna Mae

    2011-01-01

    Because cell turnover occurs in all adult organs, stem/progenitor cells within the stem-cell niche of each tissue must be appropriately mobilized and differentiated to maintain normal organ structure and function. Tissue injury increases the demands on this process, and thus may unmask defective regulation of pathways, such as Hedgehog (Hh), that modulate progenitor cell fate. Hh pathway dysregulation has been demonstrated in many types of cancer, including pancreatic and liver cancers, in which defective Hh signaling has been linked to outgrowth of Hh-responsive cancer stem-initiating cells and stromal elements. Hence, the Hh pathway might be a therapeutic target in such tumors. PMID:21188169

  10. Immunological barriers to stem-cell based cardiac repair.

    PubMed

    Karabekian, Zaruhi; Posnack, Nikki Gillum; Sarvazyan, Narine

    2011-06-01

    Repair of damaged myocardium with pluripotent stem cell derived cardiomyocytes is becoming increasingly more feasible. Developments in stem cell research emphasize the need to address the foreseeable problem of immune rejection following transplantation. Pluripotent stem cell (PSC) derived cardiomyocytes have unique immune characteristics, some of which are not advantageous for transplantation. Here we review the possible mechanisms of PSC-derived cardiomyocytes rejection, summarize the current knowledge pertaining to immunogenicity of such cells and describe the existing controversies. Myocardial graft rejection can be reduced by modifying PSCs prior to their differentiation into cardiomyocytes. Overall, this approach facilitates the development of universal donor stem cells suitable for the regeneration of many different tissue types.

  11. [Stem cell therapy: an update].

    PubMed

    Coulombel, Laure

    2009-03-01

    Medicine will be faced with a major challenge in coming years, namely how to treat for tissue dysfunction due to disease and aging There are two basic options: drug therapy and cell therapy. Stem cells have been the subject of intense speculation and controversy for several years, as they open up radically new therapeutic possibilities. Classical drugs can only smoothen consequences of tissue dysfunction, whereas cell therapy has the potential to restore tissue function by providing fresh cells. Cell therapy is totally different from organ transplantation, which can only benefit a limited number of patients. The use of the generic term "stem cells" to designate a whole variety of cell types that are present throughout life, is a source of confusion and ambiguity. It will take years of cognitive research to unravel the molecular mechanisms that govern a stem cell's multi- or totipotent status before we can fully exploit this therapeutic tool to the full. The younger a stem cell the greater its potential and, probably, the more durable its benefits, but the use of embryonic stem cells raises ethical issues. The redundancy or equivalence of diferent categories of cells is another source of controversy, yet researchers must be able to study stem cells in all their diversity, as complementary rather than competitive alternatives, in an acceptable ethical and regulatory environment. We briefly describe the three types of stem cells: pluripotent embryonic stem cells, fetal and adult stem cells, and pluripotent reprogrammed adult somatic cells. Only the former two categories have physiological functions: the first gives rise to tissues and organs while the second maintains tissue function during adulthood

  12. The role of antioxidation and immunomodulation in postnatal multipotent stem cell-mediated cardiac repair.

    PubMed

    Saparov, Arman; Chen, Chien-Wen; Beckman, Sarah A; Wang, Yadong; Huard, Johnny

    2013-08-06

    Oxidative stress and inflammation play major roles in the pathogenesis of coronary heart disease including myocardial infarction (MI). The pathological progression following MI is very complex and involves a number of cell populations including cells localized within the heart, as well as cells recruited from the circulation and other tissues that participate in inflammatory and reparative processes. These cells, with their secretory factors, have pleiotropic effects that depend on the stage of inflammation and regeneration. Excessive inflammation leads to enlargement of the infarction site, pathological remodeling and eventually, heart dysfunction. Stem cell therapy represents a unique and innovative approach to ameliorate oxidative stress and inflammation caused by ischemic heart disease. Consequently, it is crucial to understand the crosstalk between stem cells and other cells involved in post-MI cardiac tissue repair, especially immune cells, in order to harness the beneficial effects of the immune response following MI and further improve stem cell-mediated cardiac regeneration. This paper reviews the recent findings on the role of antioxidation and immunomodulation in postnatal multipotent stem cell-mediated cardiac repair following ischemic heart disease, particularly acute MI and focuses specifically on mesenchymal, muscle and blood-vessel-derived stem cells due to their antioxidant and immunomodulatory properties.

  13. Rejuvenating Strategies for Stem Cell-Based Therapies in Aging.

    PubMed

    Neves, Joana; Sousa-Victor, Pedro; Jasper, Heinrich

    2017-02-02

    Recent advances in our understanding of tissue regeneration and the development of efficient approaches to induce and differentiate pluripotent stem cells for cell replacement therapies promise exciting avenues for treating degenerative age-related diseases. However, clinical studies and insights from model organisms have identified major roadblocks that normal aging processes impose on tissue regeneration. These new insights suggest that specific targeting of environmental niche components, including growth factors, ECM, and immune cells, and intrinsic stem cell properties that are affected by aging will be critical for the development of new strategies to improve stem cell function and optimize tissue repair processes.

  14. HORSE SPECIES SYMPOSIUM: Use of mesenchymal stem cells in fracture repair in horses.

    PubMed

    Govoni, K E

    2015-03-01

    Equine bone fractures are often catastrophic, potentially fatal, and costly to repair. Traditional methods of healing fractures have limited success, long recovery periods, and a high rate of reinjury. Current research in the equine industry has demonstrated that stem cell therapy is a promising novel therapy to improve fracture healing and reduce the incidence of reinjury; however, reports of success in horses have been variable and limited. Stem cells can be derived from embryonic, fetal, and adult tissue. Based on the ease of collection, opportunity for autologous cells, and proven success in other models, adipose- or bone marrow-derived mesenchymal stem cells (MSC) are often used in equine therapies. Methods for isolation, proliferation, and differentiation of MSC are well established in rodent and human models but are not well characterized in horses. There is recent evidence that equine bone marrow MSC are able to proliferate in culture for several passages in the presence of autologous and fetal bovine serum, which is important for expansion of cells. Mesenchymal stem cells have the capacity to differentiate into osteoblasts, the bone forming cells, and this complex process is regulated by a number of transcription factors including runt-related transcription factor 2 (Runx2) and osterix (Osx). However, it has not been well established if equine MSC are regulated in a similar manner. The data presented in this review support the view that equine bone marrow MSC are regulated by the same transcription factors that control the differentiation of rodent and human MSC into osteoblasts. Although stem cell therapy is promising in equine bone repair, additional research is needed to identify optimal methods for reintroduction and potential manipulations to improve their ability to form new bone.

  15. Efficacy of Low Level Laser Therapy After Hand Flexor Tendon Repair

    NASA Astrophysics Data System (ADS)

    Ayad, K. E.; El Gohary, H. M.; Abd Elrahman, M.; Abd El Mejeed, S. F.; Bekheet, A. B.

    2009-09-01

    Flexor tendon injury is a common problem requiring suturing repair followed by early postoperative mobilization. Muscle atrophy, joint stiffness, osteoarthritis, infection, skin necrosis, ulceration of joint cartilage and tendocutaneous adhesion are familiar complications produced by prolonged immobilization of surgically repaired tendon ruptures. The purpose of this study was to clarify the importance of low level laser therapy after hand flexor tendon repair in zone II. Thirty patients aging between 20 and 40 years were divided into two groups. Patients in group A (n = 15) received a conventional therapeutic exercise program while patients in group B (n = 15) received low level laser therapy combined with the same therapeutic exercise program. The results showed a statistically significant increase in total active motion of the proximal and distal interphalangeal joints as well as maximum hand grip strength at three weeks and three months postoperative, but improvement was more significant in group B. It was concluded that the combination of low level laser therapy and early therapeutic exercises was more effective than therapeutic exercises alone in improving total active motion of proximal and distal interphalangeal joints and hand grip strength after hand flexor tendon repair.

  16. Efficacy of Low Level Laser Therapy After Hand Flexor Tendon Repair

    SciTech Connect

    Ayad, K. E.; Abd El Mejeed, S. F.; El Gohary, H. M.; Abd Elrahman, M.; Bekheet, A. B.

    2009-09-27

    Flexor tendon injury is a common problem requiring suturing repair followed by early postoperative mobilization. Muscle atrophy, joint stiffness, osteoarthritis, infection, skin necrosis, ulceration of joint cartilage and tendocutaneous adhesion are familiar complications produced by prolonged immobilization of surgically repaired tendon ruptures. The purpose of this study was to clarify the importance of low level laser therapy after hand flexor tendon repair in zone II. Thirty patients aging between 20 and 40 years were divided into two groups. Patients in group A (n = 15) received a conventional therapeutic exercise program while patients in group B (n = 15) received low level laser therapy combined with the same therapeutic exercise program. The results showed a statistically significant increase in total active motion of the proximal and distal interphalangeal joints as well as maximum hand grip strength at three weeks and three months postoperative, but improvement was more significant in group B. It was concluded that the combination of low level laser therapy and early therapeutic exercises was more effective than therapeutic exercises alone in improving total active motion of proximal and distal interphalangeal joints and hand grip strength after hand flexor tendon repair.

  17. Identification of Novel Radiosensitizers in a High-Throughput, Cell-Based Screen for DSB Repair Inhibitors

    PubMed Central

    Goglia, Alexander G.; Delsite, Robert; Luz, Antonio N.; Shahbazian, David; Salem, Ahmed F.; Sundaram, Ranjini K.; Chiaravalli, Jeanne; Hendrikx, Petrus J.; Wilshire, Jennifer A.; Jasin, Maria; Kluger, Harriet; Glickman, J. Fraser; Powell, Simon N.; Bindra, Ranjit S.

    2014-01-01

    Most cancer therapies involve a component of treatment which inflicts DNA damage in tumor cells, such as double-strand breaks (DSBs), which are considered the most serious threat to genomic integrity. Complex systems have evolved to repair these lesions, and successful DSB repair is essential for tumor cell survival after exposure to ionizing radiation (IR) and other DNA damaging agents. As such, inhibition of DNA repair is a potentially efficacious strategy for chemo- and radio-sensitization. Homologous recombination (HR) and nonhomologous end-joining (NHEJ) represent the two major pathways by DSBs are repaired in mammalian cells. Here, we report the design and execution of a high-throughput, cell-based small molecule screen for novel DSB repair inhibitors. We miniaturized our recently developed dual NHEJ and HR reporter system into a 384-well plate-based format and interrogated a diverse library of 20,000 compounds for molecules which selectively modulate NHEJ and HR repair in tumor cells. We identified a collection of novel hits which potently inhibit DSB repair, and we have validated their functional activity in comprehensive panel of orthogonal secondary assays. A selection of these inhibitors were found to radiosensitize cancer cell lines in vitro, which suggests they may be useful as novel chemo- and radio-sensitizers. Surprisingly, we identified several FDA-approved drugs, including the calcium channel blocker, mibefradil dihydrochloride, which demonstrated activity as DSB repair inhibitors and radiosensitizers. These findings suggest the possibility for repurposing them as tumor cell radiosensitizers in the future. Accordingly, we recently initiated a Phase I clinical trial testing mibefradil as glioma radiosensitizer. PMID:25512618

  18. Identification of novel radiosensitizers in a high-throughput, cell-based screen for DSB repair inhibitors.

    PubMed

    Goglia, Alexander G; Delsite, Robert; Luz, Antonio N; Shahbazian, David; Salem, Ahmed F; Sundaram, Ranjini K; Chiaravalli, Jeanne; Hendrikx, Petrus J; Wilshire, Jennifer A; Jasin, Maria; Kluger, Harriet M; Glickman, J Fraser; Powell, Simon N; Bindra, Ranjit S

    2015-02-01

    Most cancer therapies involve a component of treatment that inflicts DNA damage in tumor cells, such as double-strand breaks (DSBs), which are considered the most serious threat to genomic integrity. Complex systems have evolved to repair these lesions, and successful DSB repair is essential for tumor cell survival after exposure to ionizing radiation (IR) and other DNA-damaging agents. As such, inhibition of DNA repair is a potentially efficacious strategy for chemo- and radiosensitization. Homologous recombination (HR) and nonhomologous end-joining (NHEJ) represent the two major pathways by which DSBs are repaired in mammalian cells. Here, we report the design and execution of a high-throughput, cell-based small molecule screen for novel DSB repair inhibitors. We miniaturized our recently developed dual NHEJ and HR reporter system into a 384-well plate-based format and interrogated a diverse library of 20,000 compounds for molecules that selectively modulate NHEJ and HR repair in tumor cells. We identified a collection of novel hits that potently inhibit DSB repair, and we have validated their functional activity in a comprehensive panel of orthogonal secondary assays. A selection of these inhibitors was found to radiosensitize cancer cell lines in vitro, which suggests that they may be useful as novel chemo- and radio sensitizers. Surprisingly, we identified several FDA-approved drugs, including the calcium channel blocker mibefradil dihydrochloride, that demonstrated activity as DSB repair inhibitors and radiosensitizers. These findings suggest the possibility for repurposing them as tumor cell radiosensitizers in the future. Accordingly, we recently initiated a phase I clinical trial testing mibefradil as a glioma radiosensitizer.

  19. Potential of adult neural stem cells in stroke therapy.

    PubMed

    Andres, Robert H; Choi, Raymond; Steinberg, Gary K; Guzman, Raphael

    2008-11-01

    Despite state-of-the-art therapy, clinical outcome after stroke remains poor, with many patients left permanently disabled and dependent on care. Stem cell therapy has evolved as a promising new therapeutic avenue for the treatment of stroke in experimental studies, and recent clinical trials have proven its feasibility and safety in patients. Replacement of damaged cells and restoration of function can be accomplished by transplantation of different cell types, such as embryonic, fetal or adult stem cells, human fetal tissue and genetically engineered cell lines. Adult neural stem cells offer the advantage of avoiding the ethical problems associated with embryonic or fetal stem cells and can be harvested as autologous grafts from the individual patients. Furthermore, stimulation of endogenous adult stem cell-mediated repair mechanisms in the brain might offer new avenues for stroke therapy without the necessity of transplantation. However, important scientific issues need to be addressed to advance our understanding of the molecular mechanisms underlying the critical steps in cell-based repair to allow the introduction of these experimental techniques into clinical practice. This review describes up-to-date experimental concepts using adult neural stem cells for the treatment of stroke.

  20. Muscle repair and regeneration: stem cells, scaffolds, and the contributions of skeletal muscle to amphibian limb regeneration.

    PubMed

    Milner, Derek J; Cameron, Jo Ann

    2013-01-01

    Skeletal muscle possesses a robust innate capability for repair of tissue damage. Natural repair of muscle damage is a stepwise process that requires the coordinated activity of a number of cell types, including infiltrating macrophages, resident myogenic and non-myogenic stem cells, and connective tissue fibroblasts. Despite the proficiency of this intrinsic repair capability, severe injuries that result in significant loss of muscle tissue overwhelm the innate repair process and require intervention if muscle function is to be restored. Recent advances in stem cell biology, regenerative medicine, and materials science have led to attempts at developing tissue engineering-based methods for repairing severe muscle defects. Muscle tissue also plays a role in the ability of tailed amphibians to regenerate amputated limbs through epimorphic regeneration. Muscle contributes adult stem cells to the amphibian regeneration blastema, but it can also contribute blastemal cells through the dedifferentiation of multinucleate myofibers into mononuclear precursors. This fascinating plasticity and its contributions to limb regeneration have prompted researchers to investigate the potential for mammalian muscle to undergo dedifferentiation. Several works have shown that mammalian myotubes can be fragmented into mononuclear cells and induced to re-enter the cell cycle, but mature myofibers are resistant to fragmentation. However, recent works suggest that there may be a path to inducing fragmentation of mature myofibers into proliferative multipotent cells with the potential for use in muscle tissue engineering and regenerative therapies.

  1. MOVING STEM CELLS TO THE CLINIC: POTENTIAL AND LIMITATIONS FOR BRAIN REPAIR

    PubMed Central

    Steinbeck, Julius A.

    2015-01-01

    Summary Stem cell-based therapies hold considerable promise for many currently devastating neurological disorders. Substantial progress has been made in the derivation of disease-relevant human donor cell populations. Behavioral data in relevant animal models of disease have demonstrated therapeutic efficacy for several cell-based approaches. Consequently, GMP grade cell products are currently being developed for first in human clinical trials in select disorders. Despite the therapeutic promise, the presumed mechanism of action of donor cell populations often remains insufficiently validated. It depends greatly on the properties of the transplanted cell type and the underlying host pathology. Several new technologies have become available to probe mechanisms of action in real time and to manipulate in vivo cell function and integration to enhance therapeutic efficacy. Results from such studies generate crucial insight into the nature of brain repair that can be achieved today and push the boundaries of what may be possible in the future. PMID:25856494

  2. Activation of Type II Cells into Regenerative Stem Cell Antigen-1+ Cells during Alveolar Repair

    PubMed Central

    Kumar, Varsha Suresh; Zhang, Wei; Rehman, Jalees; Malik, Asrar B.

    2015-01-01

    The alveolar epithelium is composed of two cell types: type I cells comprise 95% of the gas exchange surface area, whereas type II cells secrete surfactant, while retaining the ability to convert into type I cells to induce alveolar repair. Using lineage-tracing analyses in the mouse model of Pseudomonas aeruginosa–induced lung injury, we identified a population of stem cell antigen (Sca)-1–expressing type II cells with progenitor cell properties that mediate alveolar repair. These cells were shown to be distinct from previously reported Sca-1–expressing bronchioalveolar stem cells. Microarray and Wnt reporter studies showed that surfactant protein (Sp)-C+Sca-1+ cells expressed Wnt signaling pathway genes, and inhibiting Wnt/β-catenin signaling prevented the regenerative function of Sp-C+Sca-1+ cells in vitro. Thus, P. aeruginosa–mediated lung injury induces the generation of a Sca-1+ subset of type II cells. The progenitor phenotype of the Sp-C+Sca-1+ cells that mediates alveolar epithelial repair might involve Wnt signaling. PMID:25474582

  3. Role of Mesenchymal Stem Cells in Dermal Repair in Burns and Diabetic Wounds.

    PubMed

    Maranda, Eric L; Rodriguez-Menocal, Luis; Badiavas, Evangelos V

    2017-01-01

    In this review we explore stem cell function in wounds that are resistant to healing, such as burn injuries and diabetic wounds. Diabetic ulcers are of interest due to their remarkable resistance to heal; severe thermal burns are addressed due to critical need for effective therapies for the prevention shock and improvement in scarring. Cell-based therapy utilizing mesenchymal stem cells (MSCs), also known as mesenchymal stromal cells, are currently being investigated as a therapeutic avenue for both chronic diabetic ulcers and severe thermal burns. The clinical utility of stem cells, in particular MSCs, in caring for these types of injuries is primarily based on repairing and replacing cellular substrates, attenuation of inflammation, increasing angiogenesis, and enhancing migration of reparative cells. MSCs are sought after due to their unique ability to initiate different wound-healing programs, depending on the environmental milieu. Thus, this review aims to highlight the properties of MSCs, including their characterization, immunogenicity, and function in the context of dermal repair and regeneration in severe burns and diabetic wounds. Additionally, relevant clinical and pre-clinical studies illustrating the impact of allogeneic and autologous sources of MSCs on therapeutic efficacy are reviewed. Insight into the properties of MSCs and the dramatic host-to-MSC interactions within these pathological states may lead to the development of effective strategies for improving outcomes in impaired wounds.

  4. Airway epithelial cell wound repair mediated by alpha-dystroglycan.

    PubMed

    White, S R; Wojcik, K R; Gruenert, D; Sun, S; Dorscheid, D R

    2001-02-01

    Dystroglycans (DGs) bind laminin matrix proteins in skeletal and cardiac muscle and are expressed in other nonmuscle tissues. However, their expression in airway epithelial cells has not been demonstrated. We examined expression of DGs in the human airway epithelial cell line 1HAEo(-), and in human primary airway epithelial cells. Expression of the common gene for alpha- and beta-DG was demonstrated by reverse transcriptase/ polymerase chain reaction in 1HAEo(-) cells. Protein expression of beta-DG was demonstrated by both Western blot and flow cytometry in cultured cells. Localization of alpha-DG, using both a monoclonal antibody and the alpha-DG binding lectin wheat-germ agglutinin (WGA), was to the cell membrane and nucleus. We then examined the function of DGs in modulating wound repair over laminin matrix. Blocking alpha-DG binding to laminin in 1HAEo(-) monolayers using either glycosyaminoglycans or WGA attenuated cell migration and spreading after mechanical injury. alpha-DG was not expressed in epithelial cells at the wound edge immediately after wound creation, but localized to the cell membrane in these cells within 12 h of injury. These data demonstrate the presence of DGs in airway epithelium. alpha-DG is dynamically expressed and serves as a lectin to bind laminin during airway epithelial cell repair.

  5. Cell Therapy for Cardiovascular Regeneration

    PubMed Central

    2013-01-01

    A great numbers of cardiovascular disease patients all over the world are suffering in the poor outcomes. Under this situation, cardiac regeneration therapy to reorganize the postnatal heart that is defined as a terminal differentiated-organ is a very important theme and mission for human beings. However, the temporary success of several clinical trials using usual cell types with uncertain cell numbers has provided the transient effect of cell therapy to these patients. We therefore should redevelop the evidence of cell-based cardiovascular regeneration therapy, focusing on targets (disease, patient’s status, cardiac function), materials (cells, cytokines, genes), and methodology (transplantation route, implantation technology, tissue engineering). Meanwhile, establishment of the induced pluripotent stem (iPS) cells is an extremely innovative technology which should be proposed as embryonic stem (ES) cellularization of post natal somatic cells, and this application have also showed the milestones of the direct conversion to reconstruct cardiomyocyte from the various somatic cells, which does not need the acquisition of the re-pluripotency. This review discusses the new advance in cardiovascular regeneration therapy from cardiac regeneration to cardiac re-organization, which is involved in recent progress of on-going clinical trials, basic research in cardiovascular regeneration, and the possibility of tissue engineering technology. PMID:23825492

  6. Variation of Mesenchymal Cells in Polylactic Acid Scaffold in an Osteochondral Repair Model

    PubMed Central

    Oshima, Yasushi; Harwood, Frederick L.; Coutts, Richard D.; Kubo, Toshikazu

    2009-01-01

    Objective To achieve osteochondral regeneration utilizing transplantation of cartilage-lineage cells and adequate scaffolds, it is essential to characterize the behavior of transplanted cells in the repair process. The objectives of this study were to elucidate the survival of mesenchymal cells (MCs). In a polylactic acid (PLA) scaffold and assess the possibility of MC/PLA constructs for osteochondral repair. Design Bone marrow from mature male rabbits was cultured for 2 weeks, and fibroblast-like MCs, which contain mesenchymal stem cells (MSCs), were obtained. A cell/scaffold construct was prepared with one million MCs and a biodegradable PLA core using a rotator device. One week after culturing, the construct was transplanted into an osteochondral defect in the medial femoral condyle of female rabbits and the healing process examined histologically. To examine the survivability of transplanted MCs, the male-derived sex-determining region Y (SRY) gene was assessed as a marker of MCs in the defect by polymerase chain reaction (PCR). Results In the groups of defects without any treatment, and the transplantation of PLA without cells, the defects were not repaired with hyaline cartilage. The cartilaginous matrix by safranin O staining and type II collagen by immunohistochemical staining were recognized, however the PLA matrix was still present in the defects at 24 weeks after transplantation of the construct. During the time passage, transplanted MCs numbers decreased from 7.8 × 105 at 1 week, to 3.5 × 105 at 4 weeks, and to 3.8 × 104 at 12 weeks. Transplanted MCs were not detectable at 24 weeks. Conclusions MCs contribute to the osteochondral repair expressing the cartilaginous matrix, however the number of MCs were decreasing with time (i.e. 24 weeks). These results could be essential for achieving cartilage regeneration by cell transplantation strategies with growth factors and/or gene therapy. PMID:19231922

  7. Hydrogels and Cell Based Therapies in Spinal Cord Injury Regeneration

    PubMed Central

    Assunção-Silva, Rita C.; Gomes, Eduardo D.; Silva, Nuno A.; Salgado, António J.

    2015-01-01

    Spinal cord injury (SCI) is a central nervous system- (CNS-) related disorder for which there is yet no successful treatment. Within the past several years, cell-based therapies have been explored for SCI repair, including the use of pluripotent human stem cells, and a number of adult-derived stem and mature cells such as mesenchymal stem cells, olfactory ensheathing cells, and Schwann cells. Although promising, cell transplantation is often overturned by the poor cell survival in the treatment of spinal cord injuries. Alternatively, the therapeutic role of different cells has been used in tissue engineering approaches by engrafting cells with biomaterials. The latter have the advantages of physically mimicking the CNS tissue, while promoting a more permissive environment for cell survival, growth, and differentiation. The roles of both cell- and biomaterial-based therapies as single therapeutic approaches for SCI repair will be discussed in this review. Moreover, as the multifactorial inhibitory environment of a SCI suggests that combinatorial approaches would be more effective, the importance of using biomaterials as cell carriers will be herein highlighted, as well as the recent advances and achievements of these promising tools for neural tissue regeneration. PMID:26124844

  8. The endomembrane requirement for cell surface repair

    NASA Technical Reports Server (NTRS)

    McNeil, Paul L.; Miyake, Katsuya; Vogel, Steven S.

    2003-01-01

    The capacity to reseal a plasma membrane disruption rapidly is required for cell survival in many physiological environments. Intracellular membrane (endomembrane) is thought to play a central role in the rapid resealing response. We here directly compare the resealing response of a cell that lacks endomembrane, the red blood cell, with that of several nucleated cells possessing an abundant endomembrane compartment. RBC membrane disruptions inflicted by a mode-locked Ti:sapphire laser, even those initially smaller than hemoglobin, failed to reseal rapidly. By contrast, much larger laser-induced disruptions made in sea urchin eggs, fibroblasts, and neurons exhibited rapid, Ca(2+)-dependent resealing. We conclude that rapid resealing is not mediated by simple physiochemical mechanisms; endomembrane is required.

  9. DNA repair and cytotoxic drugs: the potential role of RAD51 in clinical outcome of non-small-cell lung cancer patients.

    PubMed

    Nogueira, Augusto; Assis, Joana; Catarino, Raquel; Medeiros, Rui

    2013-04-01

    Many of the cytotoxic drugs used in the treatment of non-small-cell lung carcinoma patients can interfere with DNA activity and the definition of an individual DNA repair profile could be a key strategy to achieve better response to chemotherapeutic treatment. Although DNA repair mechanisms are important factors in the prevention of carcinogenesis, these molecular pathways are also involved in therapy response. RAD51 is a crucial element in DNA repair by homologous recombination and has been shown to interfere with the prognosis of patients treated with chemoradiotherapy. There is increasing evidence that genetic polymorphisms in repair enzymes can influence DNA repair capacity and, consequently, affect chemotherapy efficacy. We conducted this review to show the possible influence of the RAD51 genetic variants in damage repair capacity and treatment response in non-small-cell lung carcinoma patients.

  10. Cell Therapy in Joint Disorders

    PubMed Central

    Counsel, Peter D.; Bates, Daniel; Boyd, Richard; Connell, David A.

    2015-01-01

    Context: Articular cartilage possesses poor natural healing mechanisms, and a variety of non-cell-based and cell-based treatments aim to promote regeneration of hyaline cartilage. Data Sources: A review of the literature to December 2013 using PubMed with search criteria including the keywords stem cell, cell therapy, cell transplantation, cartilage, chondral, and chondrogenic. Study Selection: Forty-five articles were identified that employed local mesenchymal stem cell (MSC) therapy for joint disorders in humans. Nine comparative studies were identified, consisting of 3 randomized trials, 5 cohort studies, and 1 case-control study. Study Type: Clinical review. Level of Evidence: Level 4. Data Extraction: Studies were assessed for stem cell source, method of implantation, comparison groups, and concurrent surgical techniques. Results: Two studies comparing MSC treatment to autologous chondrocyte implantation found similar efficacy. Three studies reported clinical benefits with intra-articular MSC injection over non-MSC controls for cases undergoing debridement with or without marrow stimulation, although a randomized study found no significant clinical difference at 2-year follow-up but reported better 18-month magnetic resonance imaging and histologic scores in the MSC group. No human studies have compared intra-articular MSC therapy to non-MSC techniques for osteoarthritis in the absence of surgery. Conclusion: Mesenchymal stem cell–based therapies appear safe and effective for joint disorders in large animal preclinical models. Evidence for use in humans, particularly, comparison with more established treatments such as autologous chondrocyte implantation and microfracture, is limited. PMID:25553210

  11. Cell memory-based therapy

    PubMed Central

    Anjamrooz, Seyed Hadi

    2015-01-01

    Current cell therapies, despite all of the progress in this field, still faces major ethical, technical and regulatory hurdles. Because these issues possibly stem from the current, restricted, stereotypical view of cell ultrastructure and function, we must think radically about the nature of the cell. In this regard, the author's theory of the cell memory disc offers ‘memory-based therapy’, which, with the help of immune system rejuvenation, nervous system control and microparticle-based biodrugs, may have substantial therapeutic potential. In addition to its potential value in the study and prevention of premature cell aging, age-related diseases and cell death, memory therapy may improve the treatment of diseases that are currently limited by genetic disorders, risk of tumour formation and the availability and immunocompatibility of tissue transplants. PMID:26256679

  12. Transcatheter mitral valve repair therapies for primary and secondary mitral regurgitation.

    PubMed

    Al Amri, Ibtihal; van der Kley, Frank; Schalij, Martin J; Ajmone Marsan, Nina; Delgado, Victoria

    2015-03-01

    Mitral regurgitation is one of the most prevalent valvular heart diseases and its prevalence is related to population aging. Elderly patients with age-associated co-morbidities have an increased risk for conventional mitral valve surgery. Transcatheter mitral valve repair has emerged as a feasible and safe alternative in patients with contraindications for surgery or high operative risk. Several transcatheter mitral repair technologies have been developed during the last decade. While the development of some devices was abandoned due to suboptimal results, others demonstrated to be safe and effective and have been included in current practice guidelines. Not all technologies are suitable for all mitral anatomies and regurgitation mechanisms. Therefore, accurate evaluation of mitral valve anatomy and function are pivotal to the success of these therapies. Cardiac imaging plays a central role in selecting patients, guiding the procedure and evaluating the durability of the repair at follow-up.

  13. Cardiac repair in a mouse model of acute myocardial infarction with trophoblast stem cells

    PubMed Central

    Li, Guannan; Chen, Jianzhou; Zhang, Xinlin; He, Guixin; Tan, Wei; Wu, Han; Li, Ran; Chen, Yuhan; Gu, Rong; Xie, Jun; Xu, Biao

    2017-01-01

    Various stem cells have been explored for the purpose of cardiac repair. However, any individual stem cell population has not been considered as the ideal source. Recently, trophoblast stem cells (TSCs), a newly described stem cell type, have demonstrated extensive plasticity. The present study evaluated the therapeutic effect of TSCs transplantation for heart regeneration in a mouse model of myocardial infarction (MI) and made a direct comparison with the most commonly used mesenchymal stem cells (MSCs). Transplantation of TSCs and MSCs led to a remarkably improved cardiac function in contrast with the PBS control, but only the TSCs exhibited the potential of differentiation into cardiomyocytes in vivo. In addition, a significantly high proliferation level of both transplanted stem cells and resident cardiomyocytes was observed in the TSCs group. These findings primary revealed the therapeutic potential of TSCs in transplantation therapy for MI. PMID:28295048

  14. Mesenchymal stem cell secretome and regenerative therapy after cancer.

    PubMed

    Zimmerlin, Ludovic; Park, Tea Soon; Zambidis, Elias T; Donnenberg, Vera S; Donnenberg, Albert D

    2013-12-01

    Cancer treatment generally relies on tumor ablative techniques that can lead to major functional or disfiguring defects. These post-therapy impairments require the development of safe regenerative therapy strategies during cancer remission. Many current tissue repair approaches exploit paracrine (immunomodulatory, pro-angiogenic, anti-apoptotic and pro-survival effects) or restoring (functional or structural tissue repair) properties of mesenchymal stem/stromal cells (MSC). Yet, a major concern in the application of regenerative therapies during cancer remission remains the possible triggering of cancer recurrence. Tumor relapse implies the persistence of rare subsets of tumor-initiating cancer cells which can escape anti-cancer therapies and lie dormant in specific niches awaiting reactivation via unknown stimuli. Many of the components required for successful regenerative therapy (revascularization, immunosuppression, cellular homing, tissue growth promotion) are also critical for tumor progression and metastasis. While bi-directional crosstalk between tumorigenic cells (especially aggressive cancer cell lines) and MSC (including tumor stroma-resident populations) has been demonstrated in a variety of cancers, the effects of local or systemic MSC delivery for regenerative purposes on persisting cancer cells during remission remain controversial. Both pro- and anti-tumorigenic effects of MSC have been reported in the literature. Our own data using breast cancer clinical isolates have suggested that dormant-like tumor-initiating cells do not respond to MSC signals, unlike actively dividing cancer cells which benefited from the presence of supportive MSC. The secretome of MSC isolated from various tissues may partially diverge, but it includes a core of cytokines (i.e. CCL2, CCL5, IL-6, TGFβ, VEGF), which have been implicated in tumor growth and/or metastasis. This article reviews published models for studying interactions between MSC and cancer cells with a focus

  15. Cell specificity in DNA binding and repair of chemical carcinogens.

    PubMed Central

    Swenberg, J A; Rickert, D E; Baranyi, B L; Goodman, J I

    1983-01-01

    Many animal models for organ specific neoplasia have been developed and used to study the pathogenesis of cancer. Morphologic studies have usually concentrated on the response of target cells, whereas biochemical investigations have usually employed whole organ homogenates. Since hepatocytes comprise nearly 90% of the liver's mass and 70-80% of its DNA, alterations in DNA replication, covalent binding and DNA repair of nonparenchymal cells are usually obscured when whole organ homogenates are used. By utilizing cell separation methods, we have been able to demonstrate differences between hepatocyte and nonparenchymal cell replication. DNA damage and repair following exposure to a variety of hepatocarcinogen. Differences in removal of simple O6-alkylguanine and DNA replication correlate with cell specific carcinogenesis of simply alkylating agents. For several other procarcinogens, including 2-acetylaminofluorene and dinitroluene, cell specificity appears to reside primarily in the differential metabolic competence of hepatocytes and nonparenchymal cells. This results in greater covalent binding of the carcinogen to hepatocyte DNA, although the DNA adducts are removed at a similar rate in both cell types. Images FIGURE 1. PMID:6832089

  16. Platelet-rich plasma, an adjuvant biological therapy to assist peripheral nerve repair

    PubMed Central

    Sánchez, Mikel; Garate, Ane; Delgado, Diego; Padilla, Sabino

    2017-01-01

    Therapies such as direct tension-free microsurgical repair or transplantation of a nerve autograft, are nowadays used to treat traumatic peripheral nerve injuries (PNI), focused on the enhancement of the intrinsic regenerative potential of injured axons. However, these therapies fail to recreate the suitable cellular and molecular microenvironment of peripheral nerve repair and in some cases, the functional recovery of nerve injuries is incomplete. Thus, new biomedical engineering strategies based on tissue engineering approaches through molecular intervention and scaffolding offer promising outcomes on the field. In this sense, evidence is accumulating in both, preclinical and clinical settings, indicating that platelet-rich plasma products, and fibrin scaffold obtained from this technology, hold an important therapeutic potential as a neuroprotective, neurogenic and neuroinflammatory therapeutic modulator system, as well as enhancing the sensory and motor functional nerve muscle unit recovery. PMID:28250739

  17. Myelin repair and functional recovery mediated by neural cell transplantation in a mouse model of multiple sclerosis

    PubMed Central

    Bai, Lianhua; Hecker, Jordan; Kerstetter, Amber; Miller, Robert H.

    2014-01-01

    Cellular therapies are becoming a major focus for the treatment of demyelinating diseases such as multiple sclerosis (MS), therefore it is important to identify the most effective cell types that promote myelin repair. Several components contribute to the relative benefits of specific cell types including the overall efficacy of the cell therapy, the reproducibility of treatment, the mechanisms of action of distinct cell types and the ease of isolation and generation of therapeutic populations. A range of distinct cell populations promote functional recovery in animal models of MS including neural stem cells and mesenchymal stem cells derived from different tissues. Each of these cell populations has advantages and disadvantages and likely works through distinct mechanisms. The relevance of such mechanisms to myelin repair in the adult central nervous system is unclear since the therapeutic cells are generally derived from developing animals. Here we describe the isolation and characterization of a population of neural cells from the adult spinal cord that are characterized by the expression of the cell surface glycoprotein NG2. In functional studies, injection of adult NG2+ cells into mice with ongoing MOG35-55-induced experimental autoimmune encephalomyelitis (EAE) enhanced remyelination in the CNS while the number of CD3+ T cells in areas of spinal cord demyelination was reduced approximately three-fold. In vivo studies indicated that in EAE, NG2+ cells stimulated endogenous repair while in vitro they responded to signals in areas of induced inflammation by differentiating into oligodendrocytes. These results suggested that adult NG2+ cells represent a useful cell population for promoting neural repair in a variety of different conditions including demyelinating diseases such as MS. PMID:23471865

  18. Targeting DNA repair and the cell cycle in glioblastoma.

    PubMed

    Alexander, Brian M; Pinnell, Nancy; Wen, Patrick Y; D'Andrea, Alan

    2012-05-01

    Glioblastoma is a disease with poor outcomes despite standard therapy. Specific targeting of the DNA damage response is a strategy that is becoming increasingly employed in oncology and has intriguing potential for improving outcomes in glioblastoma. DNA damage targeting has implications for improving current therapy as well as the potential to leverage inherent differences in glioblastoma cells to widen the therapeutic window.

  19. Cell Therapy Regulation in Taiwan.

    PubMed

    Chen, Yuan-Chuan; Cheng, Hwei-Fang; Yeh, Ming-Kung

    2017-03-13

    Cell therapy is not only a novel medical practice but also a medicinal product [cell therapy product (CTP)]. More and more CTPs are being approved for marketing globally because of the rapid development of biomedicine in cell culture, preservation, and preparation. However, regulation is the most important criterion for the development of CTPs. Regulations must be flexible to expedite the process of marketing for new CTPs. Recently, the Taiwan Food and Drug Administration (TFDA) updated the related regulations such as regulation of development, current regulatory framework and process, and the application and evaluation processes. When the quality of CTPs has been improved significantly, their safety and efficacy are further ensured. The treatment protocol, a new design for adaptive licensing to current clinical practice, is a rapid process for patients with life-threatening diseases or serious conditions for which there are no suitable drugs, medical devices, or other therapeutic methods available. The hospital can submit the treatment protocol to apply for cell therapy as a medical practice, which may result in easier and faster cell therapy development, and personalized treatment for individual patients will evolve quickly.

  20. Role of biomechanics on intervertebral disc degeneration and regenerative therapies: What needs repairing in the disc and what are promising biomaterials for its repair?

    PubMed Central

    Iatridis, James C.; Nicoll, Steven B.; Michalek, Arthur J.; Walter, Benjamin A.; Gupta, Michelle S.

    2013-01-01

    Background Context Degeneration and injuries of the intervertebral disc result in large alterations in biomechanical behaviors. Repair strategies using biomaterials can be optimized based on biomechanical and biological requirements. Purpose To review current literature on 1) effects of degeneration, simulated degeneration, and injury on biomechanics of the intervertebral disc with special attention paid to needle puncture injuries which are a pathway for diagnostics and regenerative therapies; and 2) promising biomaterials for disc repair with a focus on how those biomaterials may promote biomechanical repair. Study Design/Setting A narrative review to evaluate the role of biomechanics on disc degeneration and regenerative therapies with a focus on what biomechanical properties need to be repaired and how to evaluate and accomplish such repairs using biomaterials. Model systems for screening of such repair strategies are also briefly described. Methods Papers were selected from two main Pubmed searches using keywords: intervertebral AND biomechanics (1823 articles) and intervertebral AND biomaterials (361 articles). Additional keywords (injury, needle puncture, nucleus pressurization, biomaterials, hydrogel, sealant, tissue engineering) were used to narrow articles to the topics most relevant to this review. Results Degeneration and acute disc injuries have the capacity to influence nucleus pulposus pressurization and annulus fibrosus integrity, which are necessary for effective disc function, and therefore, require repair. Needle injection injuries are of particular clinical relevance with potential to influence disc biomechanics, cellularity, and metabolism, yet these effects are localized or small, and more research is required to evaluate and reduce potential clinical morbidity using such techniques. NP replacement strategies, such as hydrogels, are required to restore NP pressurization or lost volume. AF repair strategies, including crosslinked hydrogels

  1. Cell therapy in kidney disease: cautious optimism... but optimism nonetheless.

    PubMed

    Zenovich, Andrey G; Taylor, Doris A

    2007-06-01

    The recently discovered therapeutic potential of stem or progenitor cells has initiated development of novel treatments in a number of diseases-treatments that could not only improve patients' quality of life, but also halt or even prevent disease progression. Hypertension; fluctuations in glycemia, electrolytes, nutrient levels, and circulating volume; and frequent infections and the associated inflammation all greatly impair the endothelium in patients undergoing peritoneal dialysis. As our understanding of the regulatory function of the endothelium advances, focus is increasingly being placed on endothelial repair in acute and chronic renal failure and after renal transplantation. The potential of progenitor cells to repair damaged endothelium and to reduce inflammation in patients with renal failure remains unexamined; however, a successful cell therapy could reduce morbidity and mortality in kidney disease. Important contributions have been made in identifying progenitor cell populations in the kidney, and further investigations into the relationships of these cells with the pathophysiology of the disease are underway. As the kidney disease field prepares for the first human trials of progenitor cell therapies, we deemed it important to review representative original research, and to share our perspectives and lessons learned from clinical trials of progenitor cell-based therapies that have commenced in patients with cardiovascular disease.

  2. Advances in stem cell therapy for cardiovascular disease (Review)

    PubMed Central

    SUN, RONGRONG; LI, XIANCHI; LIU, MIN; ZENG, YI; CHEN, SHUANG; ZHANG, PEYING

    2016-01-01

    Cardiovascular disease constitutes the primary cause of mortality and morbidity worldwide, and represents a group of disorders associated with the loss of cardiac function. Despite considerable advances in the understanding of the pathologic mechanisms of the disease, the majority of the currently available therapies remain at best palliative, since the problem of cardiac tissue loss has not yet been addressed. Indeed, few therapeutic approaches offer direct tissue repair and regeneration, whereas the majority of treatment options aim to limit scar formation and adverse remodeling, while improving myocardial function. Of all the existing therapeutic approaches, the problem of cardiac tissue loss is addressed uniquely by heart transplantation. Nevertheless, alternative options, particularly stem cell therapy, has emerged as a novel and promising approach. This approach involves the transplantation of healthy and functional cells to promote the renewal of damaged cells and repair injured tissue. Bone marrow precursor cells were the first cell type used in clinical studies, and subsequently, preclinical and clinical investigations have been extended to the use of various populations of stem cells. This review addresses the present state of research as regards stem cell therapy for cardiovascular disease. PMID:27220939

  3. Glial differentiation of human inferior turbinate-derived stem cells: a new source of cells for nerve repair.

    PubMed

    Li, Yang; Sheng, Ying; Liang, JianMin; Ren, XiaoYong; Cheng, Yan

    2017-03-22

    Schwann cell (SC) transplantation as a cell-based therapy can enhance peripheral and central nerve repair experimentally, but it is limited by donor site morbidity for clinical application. We investigated whether human turbinate-derived mesenchymal stem cells (hTMSCs) isolated from discarded inferior turbinate during surgery can differentiate into functional SC-like cells. hTMSCs expressed mesenchymal cell surface markers CD29, CD44, CD90, and CD105 and did not express neural crest markers P75 and Nestin. After monolayer culture in predifferentiation medium and transdifferentiation medium with a mixture of glial growth factors and chemical regents for 14 days, the differentiated hTMSCs exhibited a spindle-like morphology similar to that of SCs. RT-PCR, immunocytochemical staining, and western blotting analysis indicated that SC-like cells expressed the glial markers S100β, P75, and glial fibrillary acidic protein at the gene and protein level. Compared with hTMSCs, differentiated hTMSCs secreted more neurotrophins, and significantly enhanced the neurite length when cocultured with dorsal root ganglia neuronal cells. Our data indicated that hTMSCs can differentiate into functional SC-like cells and have the ability to facilitate the neurite growth of dorsal root ganglia neuronal cells in vitro, representing a promising source of cells for nerve repair.

  4. Cell therapy for autoimmune diseases

    PubMed Central

    Dazzi, Francesco; van Laar, Jacob M; Cope, Andrew; Tyndall, Alan

    2007-01-01

    Cell therapy, pioneered for the treatment of malignancies in the form of bone marrow transplantation, has subsequently been tested and successfully employed in autoimmune diseases. Autologous haemopoietic stem cell transplantation (HSCT) has become a curative option for conditions with very poor prognosis such as severe forms of scleroderma, multiple sclerosis, and lupus, in which targeted therapies have little or no effect. The refinement of the conditioning regimens has virtually eliminated transplant-related mortality, thus making HSCT a relatively safe choice. Although HSCT remains a nonspecific approach, the knowledge gained in this field has led to the identification of new avenues. In fact, it has become evident that the therapeutic efficacy of HSCT cannot merely be the consequence of a high-dose immuno-suppression, but rather the result of a resetting of the abnormal immune regulation underlying autoimmune conditions. The identification of professional and nonprofessional immunosuppressive cells and their biological properties is generating a huge interest for their clinical exploitation. Regulatory T cells, found abnormal in several autoimmune diseases, have been proposed as central to achieve long-term remissions. Mesenchymal stem cells of bone marrow origin have more recently been shown not only to be able to differentiate into multiple tissues, but also to exert a potent antiproliferative effect that results in the inhibition of immune responses and prolonged survival of haemopoietic stem cells. All of these potential resources clearly need to be investigated at the preclinical level but support a great deal of enthusiasm for cell therapy of autoimmune diseases. PMID:17367542

  5. The role of BRCA1 in homologous recombination repair in response to replication stress: significance in tumorigenesis and cancer therapy

    PubMed Central

    2013-01-01

    Germ line mutations in breast cancer gene 1 (BRCA1) predispose women to breast and ovarian cancers. Although BRCA1 is involved in many important biological processes, the function of BRCA1 in homologous recombination (HR) mediated repair is considered one of the major mechanisms contributing to its tumor suppression activity, and the cause of hypersensitivity to poly(ADP-ribose) polymerase (PARP) inhibitors when BRCA1 is defective. Mounting evidence suggests that the mechanism of repairing DNA double strand breaks (DSBs) by HR is different than the mechanism operating when DNA replication is blocked. Although BRCA1 has been recognized as a central component in HR, the precise role of BRCA1 in HR, particularly under replication stress, has remained largely unknown. Given the fact that DNA lesions caused by replication blockages are the primary substrates for HR in mitotic cells, functional analysis of BRCA1 in HR repair in the context of replication stress should benefit our understanding of the molecular mechanisms underlying tumorigenesis associated with BRCA1 deficiencies, as well as the development of therapeutic approaches for cancer patients carrying BRCA1 mutations or reduced BRCA1 expression. This review focuses on the current advances in this setting and also discusses the significance in tumorigenesis and cancer therapy. PMID:23388117

  6. Electrical Stimulation Elicits Neural Stem Cells Activation: New Perspectives in CNS Repair

    PubMed Central

    Huang, Yanhua; Li, YeE; Chen, Jian; Zhou, Hongxing; Tan, Sheng

    2015-01-01

    Researchers are enthusiastically concerned about neural stem cell (NSC) therapy in a wide array of diseases, including stroke, neurodegenerative disease, spinal cord injury, and depression. Although enormous evidences have demonstrated that neurobehavioral improvement may benefit from NSC-supporting regeneration in animal models, approaches to endogenous and transplanted NSCs are blocked by hurdles of migration, proliferation, maturation, and integration of NSCs. Electrical stimulation (ES) may be a selective non-drug approach for mobilizing NSCs in the central nervous system. This technique is suitable for clinical application, because it is well established and its potential complications are manageable. Here, we provide a comprehensive review of the emerging positive role of different electrical cues in regulating NSC biology in vitro and in vivo, as well as biomaterial-based and chemical stimulation of NSCs. In the future, ES combined with stem cell therapy or other cues probably becomes an approach for promoting brain repair. PMID:26539102

  7. Morphologic changes in basal cells during repair of tracheal epithelium.

    PubMed Central

    Wang, C. Z.; Evans, M. J.; Cox, R. A.; Burke, A. S.; Zhu, Q.; Herndon, D. N.; Barrow, R. E.

    1992-01-01

    Basal cells are differentiated with respect to junctional adhesion mechanisms and play a role in attachment of columnar epithelium to the basal lamina. Although much is known about nonciliated and ciliated cell differentiation during the repair process after injury, little is known about the basal cell. We studied the morphology of basal cells and quantitated junctional adhesion structures during repair of tracheal epithelium exposed to toxic cotton smoke. Ten adult ewes were given a smoke injury to a portion of the upper cervical trachea and were killed at 4, 6, 8, 10, and 18 days after injury for morphometric studies. At 4 days, there was a stratified reparative epithelium over the basal lamina, which was two to four cells in depth. The basal cells were identified by their hemidesmosome (HD) attachment to the basal lamina. Basal cells were about 69% larger than controls and flattened rather than columnar. The amount of HD attachment was 192% greater than controls. In contrast, volume density of cytokeratin filaments had decreased about 47%. Basal cells had returned to normal numbers and size and a columnar shape by day 18. The amount of desmosome (D) and HD attachment and volume density of cytokeratins had also reached control levels by day 18. These data indicate that morphology of basal cells changes during the initial stages of reparative regeneration but returns to normal by 18 days. Morphologic changes appear to reflect changes in size of the cell associated with cell division rather than differentiation of recently divided basal cells. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:1381564

  8. DSB repair model for mammalian cells in early S and G1 phases of the cell cycle: application to damage induced by ionizing radiation of different quality.

    PubMed

    Taleei, Reza; Girard, Peter M; Nikjoo, Hooshang

    2015-02-01

    The purpose of this work is to test the hypothesis that kinetics of double strand breaks (DSB) repair is governed by complexity of DSB. To test the hypothesis we used our recent published mechanistic mathematical model of DSB repair for DSB induced by selected protons, deuterons, and helium ions of different energies representing radiations of different qualities. In light of recent advances in experimental and computational techniques, the most appropriate method to study cellular responses in radiation therapy, and exposures to low doses of ionizing radiations is using mechanistic approaches. To this end, we proposed a 'bottom-up' approach to study cellular response that starts with the DNA damage. Monte Carlo track structure method was employed to simulate initial damage induced in the genomic DNA by direct and indirect effects. Among the different types of DNA damage, DSB are known to be induced in simple and complex forms. The DSB repair model in G1 and early S phases of the cell cycle was employed to calculate the repair kinetics. The model considers the repair of simple and complex DSB, and the DSB produced in the heterochromatin. The inverse sampling method was used to calculate the repair kinetics for each individual DSB. The overall repair kinetics for 500 DSB induced by single tracks of the radiation under test were compared with experimental results. The results show that the model is capable of predicting the repair kinetics for the DSB induced by radiations of different qualities within an accepted range of uncertainty.

  9. Non-DBS DNA Repair Genes Regulate Radiation-induced Cytogenetic Damage Repair and Cell Cycle Progression

    NASA Technical Reports Server (NTRS)

    Zhang, Ye; Rohde, Larry H.; Emami, Kamal; Casey, Rachael; Wu, Honglu

    2008-01-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in DSB repair, and its impact on cytogenetic responses has not been systematically studied. In the present study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by transfection with small interfering RNA in human fibroblast cells. The purpose of this study is to identify new roles of these selected genes on regulating DSB repair and cell cycle progression , as measured in the micronuclei formation and chromosome aberration. In response to IR, the formation of MN was significantly increased by suppressed expression of 5 genes: Ku70 in the DSB repair pathway, XPA in the NER pathway, RPA1 in the MMR pathway, and RAD17 and RBBP8 in cell cycle control. Knocked-down expression of 4 genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Furthermore, loss of XPA, P21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Most of the 11 genes that affected cytogenetic responses are not known to have clear roles influencing DBS repair. Nine of these 11 genes were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate the biological consequences after IR.

  10. Virus integration and genome influence in approaches to stem cell based therapy for andro-urology.

    PubMed

    Li, Longkun; Zhang, Deying; Li, Peng; Damaser, Margot; Zhang, Yuanyuan

    2015-03-01

    Despite the potential of stem cells in cell-based therapy, major limitations such as cell retention, ingrowth, and trans-differentiation after implantation remain. One technique for genetic modification of cells for tissue repair is the introduction of specific genes using molecular biology techniques, such as virus integration, to provide a gene that adds new functions to enhance cellular function, and to secrete trophic factors for recruiting resident cells to participate in tissue repair. Stem cells can be labeled to track cell survival, migration, and lineage. Increasing evidence demonstrates that cell therapy and gene therapy in combination remarkably improve differentiation of implanted mesenchymal stromal cells (MSCs), revascularization, and innervation in genitourinary tissues, especially to treat urinary incontinence, erectile dysfunction, lower urinary tract reconstruction, and renal failure. This review discusses the benefits, safety, side effects, and alternatives for using genetically modified MSCs in tissue regeneration in andro-urology.

  11. Virus Integration and Genome Influence in Approaches to Stem Cell Based Therapy for Andro-Urology

    PubMed Central

    Li, Longkun; Zhang, Deying; Li, Peng; Damaser, Margot; Zhang, Yuanyuan

    2014-01-01

    Despite the potential of stem cells in cell-based therapy, major limitations such as cell retention, ingrowth, and trans-differentiation after implantation remain. One technique for genetic modification of cells for tissue repair is the introduction of specific genes using molecular biology techniques, such as virus integration, to provide a gene that adds new functions to enhance cellular function, and to secrete trophic factors for recruiting resident cells to participate in tissue repair. Stem cells can be labelled to track cell survival, migration, and lineage. Increasing evidence demonstrates that cell therapy and gene therapy in combination remarkably improve myogenic differentiation of implanted mesenchymal stromal cells (MSCs), revascularization, and innervation in genitourinary tissues, especially to treat urinary incontinence, erectile dysfunction, lower urinary tract reconstruction, and renal failure. This review discusses the benefits, safety, side effects, and alternatives for using genetically modified MSCs in tissue regeneration in andro-urology. PMID:25453258

  12. Cell death, remodeling, and repair in chronic obstructive pulmonary disease?

    PubMed

    Henson, Peter M; Vandivier, R William; Douglas, Ivor S

    2006-11-01

    Apoptotic cells can be detected in the parenchyma and airways of patients with chronic obstructive pulmonary disease (COPD) in greater numbers than seen in normal lungs or those from smokers without COPD. Implications include more apoptosis and/or decreased clearance of apoptotic cells. Both epithelial and endothelial cells become apoptotic. What role does the apoptosis play in the emphysema or small airway alterations seen in COPD? In simple terms, loss of cells by apoptosis would be expected to accompany, or perhaps initiate, the overall tissue destruction normally believed responsible. Indeed, direct induction of apoptosis in pulmonary endothelial or epithelial cells in rodents is accompanied by emphysematous changes. On the other hand, apoptotic cells are normally removed from tissues rapidly with minimal tissue response, to be followed by cell replacement to maintain homeostasis. The presence of detectable apoptotic cells, therefore, may imply defects in these clearance mechanisms, and, in keeping with this hypothesis, there is increasing evidence for such defects in patients with COPD. Mice with abnormalities in apoptotic cell removal also tend to develop spontaneous "emphysema." A reconciling hypothesis is that recognition of apoptotic cells not only leads to removal but also, normally, to signals for cell replacement. If this latter response is lacking in COPD-susceptible smokers, defects in normal alveolar or small airway repair could significantly contribute to the structural disruption. The concept puts emphasis on defective repair as well as initial injury (i.e., persistent alteration of dynamic tissue homeostasis, as a key contributor to COPD), with, it is hoped, additional approaches for mitigation.

  13. Frequency of intrachromosomal homologous recombination induced by UV radiation in normally repairing and excision repair-deficient human cells

    SciTech Connect

    Tsujimura, T.; Maher, V.M.; McCormick, J.J. ); Godwin, A.R.; Liskay, R.M. )

    1990-02-01

    To investigate the role of DNA damage and nucleotide excision repair in intrachromosomal homologous recombination, a plasmid containing duplicated copies of the gene coding for hygromycin resistance was introduced into the genome of a repair-proficient human cell line, KMST-6, and two repair-deficient lines, XP2OS(SV) from xeroderma pigmentosum complementation group A and XP2YO(SV) from complementation group F. Neither hygromycin-resistance gene codes for a functional enzyme because each contains an insertion/deletion mutation at a unique site, but recombination between the two defective genes can yield hygromycin-resistant cells. The rates of spontaneous recombination in normal and xeroderma pigmentosum cell strains containing the recombination substrate were found to be similar. The frequency of UV-induced recombination was determined for three of these cell strains. At low doses, the group A cell strain and the group F cell strain showed a significant increase in frequency of recombinants. The repair-proficient cell strain required 10-to 20-fold higher doses of UV to exhibit comparable increases in frequency of recombinants. These results suggest that unexcised DNA damage, rather than the excision repair process per se, stimulates such recombination.

  14. Next Generation Mesenchymal Stem Cell (MSC)–Based Cartilage Repair Using Scaffold-Free Tissue Engineered Constructs Generated with Synovial Mesenchymal Stem Cells

    PubMed Central

    Shimomura, Kazunori; Ando, Wataru; Moriguchi, Yu; Sugita, Norihiko; Yasui, Yukihiko; Koizumi, Kota; Fujie, Hiromichi; Hart, David A.; Yoshikawa, Hideki

    2015-01-01

    Because of its limited healing capacity, treatments for articular cartilage injuries are still challenging. Since the first report by Brittberg, autologous chondrocyte implantation has been extensively studied. Recently, as an alternative for chondrocyte-based therapy, mesenchymal stem cell–based therapy has received considerable research attention because of the relative ease in handling for tissue harvest, and subsequent cell expansion and differentiation. This review summarizes latest development of stem cell therapies in cartilage repair with special attention to scaffold-free approaches. PMID:27340513

  15. Regenerative medicine for the kidney: renotropic factors, renal stem/progenitor cells, and stem cell therapy.

    PubMed

    Maeshima, Akito; Nakasatomi, Masao; Nojima, Yoshihisa

    2014-01-01

    The kidney has the capacity for regeneration and repair after a variety of insults. Over the past few decades, factors that promote repair of the injured kidney have been extensively investigated. By using kidney injury animal models, the role of intrinsic and extrinsic growth factors, transcription factors, and extracellular matrix in this process has been examined. The identification of renal stem cells in the adult kidney as well as in the embryonic kidney is an active area of research. Cell populations expressing putative stem cell markers or possessing stem cell properties have been found in the tubules, interstitium, and glomeruli of the normal kidney. Cell therapies with bone marrow-derived hematopoietic stem cells, mesenchymal stem cells, endothelial progenitor cells, and amniotic fluid-derived stem cells have been highly effective for the treatment of acute or chronic renal failure in animals. Embryonic stem cells and induced pluripotent stem cells are also utilized for the construction of artificial kidneys or renal components. In this review, we highlight the advances in regenerative medicine for the kidney from the perspective of renotropic factors, renal stem/progenitor cells, and stem cell therapies and discuss the issues to be solved to realize regenerative therapy for kidney diseases in humans.

  16. Repairing skeletal muscle: regenerative potential of skeletal muscle stem cells

    PubMed Central

    Tedesco, Francesco Saverio; Dellavalle, Arianna; Diaz-Manera, Jordi; Messina, Graziella; Cossu, Giulio

    2010-01-01

    Skeletal muscle damaged by injury or by degenerative diseases such as muscular dystrophy is able to regenerate new muscle fibers. Regeneration mainly depends upon satellite cells, myogenic progenitors localized between the basal lamina and the muscle fiber membrane. However, other cell types outside the basal lamina, such as pericytes, also have myogenic potency. Here, we discuss the main properties of satellite cells and other myogenic progenitors as well as recent efforts to obtain myogenic cells from pluripotent stem cells for patient-tailored cell therapy. Clinical trials utilizing these cells to treat muscular dystrophies, heart failure, and stress urinary incontinence are also briefly outlined. PMID:20051632

  17. Subchondral pre-solidified chitosan/blood implants elicit reproducible early osteochondral wound-repair responses including neutrophil and stromal cell chemotaxis, bone resorption and repair, enhanced repair tissue integration and delayed matrix deposition

    PubMed Central

    2013-01-01

    Background In this study we evaluated a novel approach to guide the bone marrow-driven articular cartilage repair response in skeletally aged rabbits. We hypothesized that dispersed chitosan particles implanted close to the bone marrow degrade in situ in a molecular mass-dependent manner, and attract more stromal cells to the site in aged rabbits compared to the blood clot in untreated controls. Methods Three microdrill hole defects, 1.4 mm diameter and 2 mm deep, were created in both knee trochlea of 30 month-old New Zealand White rabbits. Each of 3 isotonic chitosan solutions (150, 40, 10 kDa, 80% degree of deaceylation, with fluorescent chitosan tracer) was mixed with autologous rabbit whole blood, clotted with Tissue Factor to form cylindrical implants, and press-fit in drill holes in the left knee while contralateral holes received Tissue Factor or no treatment. At day 1 or day 21 post-operative, defects were analyzed by micro-computed tomography, histomorphometry and stereology for bone and soft tissue repair. Results All 3 implants filled the top of defects at day 1 and were partly degraded in situ at 21 days post-operative. All implants attracted neutrophils, osteoclasts and abundant bone marrow-derived stromal cells, stimulated bone resorption followed by new woven bone repair (bone remodeling) and promoted repair tissue-bone integration. 150 kDa chitosan implant was less degraded, and elicited more apoptotic neutrophils and bone resorption than 10 kDa chitosan implant. Drilled controls elicited a poorly integrated fibrous or fibrocartilaginous tissue. Conclusions Pre-solidified implants elicit stromal cells and vigorous bone plate remodeling through a phase involving neutrophil chemotaxis. Pre-solidified chitosan implants are tunable by molecular mass, and could be beneficial for augmented marrow stimulation therapy if the recruited stromal cells can progress to bone and cartilage repair. PMID:23324433

  18. Regulation of DNA repair in serum-stimulated xeroderma pigmentosum cells

    SciTech Connect

    Gupta, P.K.; Sirover, M.A.

    1984-10-01

    The regulation of DNA repair during serum stimulation of quiescent cells was examined in normal human cells, in fibroblasts from three xeroderma pigmentosum complementation groups (A, C, and D), in xeroderma pigmentosum variant cells, and in ataxia telangiectasia cells. The regulation of nucleotide excision repair was examined by exposing cells to ultraviolet irradiation at discrete intervals after cell stimulation. Similarly, base excision repair was quantitated after exposure to methylmethane sulfonate. WI-38 normal human diploid fibroblasts, xeroderma pigmentosum variant cells, as well as ataxia telangiectasia cells enhanced their capacity for both nucleotide excision repair and for base excision repair prior to their enhancement of DNA synthesis. Further, in each cell strain, the base excision repair enzyme uracil DNA glycosylase was increased prior to the induction of DNA polymerase using the identical cells to quantitate each activity. In contrast, each of the three xeroderma complementation groups that were examined failed to increase their capacity for nucleotide excision repair above basal levels at any interval examined. This result was observed using either unscheduled DNA synthesis in the presence of 10 mM hydroxyurea or using repair replication in the absence of hydroxyurea to quantitate DNA repair. However, each of the three complementation groups normally regulated the enhancement of base excision repair after methylmethane sulfonate exposure and each induced the uracil DNA glycosylase prior to DNA synthesis. 62 references, 3 figures, 2 tables.

  19. Schwann cell transplantation for spinal cord injury repair: its significant therapeutic potential and prospectus.

    PubMed

    Kanno, Haruo; Pearse, Damien D; Ozawa, Hiroshi; Itoi, Eiji; Bunge, Mary Bartlett

    2015-01-01

    Transplantation of Schwann cells (SCs) is a promising therapeutic strategy for spinal cord repair. The introduction of SCs into the injured spinal cord has been shown to reduce tissue loss, promote axonal regeneration, and facilitate myelination of axons for improved sensorimotor function. The pathology of spinal cord injury (SCI) comprises multiple processes characterized by extensive cell death, development of a milieu inhibitory to growth, and glial scar formation, which together limits axonal regeneration. Many studies have suggested that significant functional recovery following SCI will not be possible with a single therapeutic strategy. The use of additional approaches with SC transplantation may be needed for successful axonal regeneration and sufficient functional recovery after SCI. An example of such a combination strategy with SC transplantation has been the complementary administration of neuroprotective agents/growth factors, which improves the effect of SCs after SCI. Suspension of SCs in bioactive matrices can also enhance transplanted SC survival and increase their capacity for supporting axonal regeneration in the injured spinal cord. Inhibition of glial scar formation produces a more permissive interface between the SC transplant and host spinal cord for axonal growth. Co-transplantation of SCs and other types of cells such as olfactory ensheathing cells, bone marrow mesenchymal stromal cells, and neural stem cells can be a more effective therapy than transplantation of SCs alone following SCI. This article reviews some of the evidence supporting the combination of SC transplantation with additional strategies for SCI repair and presents a prospectus for achieving better outcomes for persons with SCI.

  20. Adult stem cells in neural repair: Current options, limitations and perspectives.

    PubMed

    Mariano, Eric Domingos; Teixeira, Manoel Jacobsen; Marie, Suely Kazue Nagahashi; Lepski, Guilherme

    2015-03-26

    Stem cells represent a promising step for the future of regenerative medicine. As they are able to differentiate into any cell type, tissue or organ, these cells are great candidates for treatments against the worst diseases that defy doctors and researchers around the world. Stem cells can be divided into three main groups: (1) embryonic stem cells; (2) fetal stem cells; and (3) adult stem cells. In terms of their capacity for proliferation, stem cells are also classified as totipotent, pluripotent or multipotent. Adult stem cells, also known as somatic cells, are found in various regions of the adult organism, such as bone marrow, skin, eyes, viscera and brain. They can differentiate into unipotent cells of the residing tissue, generally for the purpose of repair. These cells represent an excellent choice in regenerative medicine, every patient can be a donor of adult stem cells to provide a more customized and efficient therapy against various diseases, in other words, they allow the opportunity of autologous transplantation. But in order to start clinical trials and achieve great results, we need to understand how these cells interact with the host tissue, how they can manipulate or be manipulated by the microenvironment where they will be transplanted and for how long they can maintain their multipotent state to provide a full regeneration.

  1. The role of microvesicles derived from mesenchymal stem cells in tissue regeneration; a dream for tendon repair?

    PubMed Central

    Tetta, Ciro; Consiglio, Anna Lange; Bruno, Stefania; Tetta, Emanuele; Gatti, Emanuele; Dobreva, Miryana; Cremonesi, Fausto; Camussi, Giovanni

    2012-01-01

    Summary Tendon injuries represent even today a challenge as repair may be exceedingly slow and incomplete. Regenerative medicine and stem cell technology have shown to be of great promise. Here, we will review the current knowledge on the mechanisms of the regenerative potential of mesenchymal stem cells (MSCs) obtained from different sources (bone marrow, fat, cord blood, placenta). More specifically, we will devote attention to the current use of MSCs that have been used experimentally and in limited numbers of clinical cases for the surgical treatment of subchondral-bone cysts, bone-fracture repair and cartilage repair. Based on the recently emerging role in regenerative mechanisms of soluble factors and of extracellular vesicles, we will discuss the potential of non-cellular therapies in horse tendon injuries. PMID:23738299

  2. Pluripotent Stem Cell Derived Cardiomyocytes for Cardiac Repair

    PubMed Central

    Lundy, Scott D.; Gantz, Jay A.; Pagan, Chelsea M.; Filice, Dominic; Laflamme, Michael A.

    2014-01-01

    Opinion Statement The adult mammalian heart has limited capacity for generation, so a major injury such as a myocardial infarction results in the permanent loss of up to one billion cardiomyocytes. The field of cardiac cell therapy aims to replace these lost contractile units with de novo cardiomyocytes to restore lost systolic function and prevent progression to heart failure. Arguably the ideal cell for this application is the human cardiomyocyte itself, which can electromechanically couple with host myocardium and contribute active systolic force. Pluripotent stem cells from both human embryonic or induced pluripotent lineages are attractive sources for cardiomyocytes, and preclinical investigation of these cells is in progress. Recent work has focused on efficient generation and purification of cardiomyocytes, tissue engineering efforts, and examining the consequences of cell transplantation from mechanical, vascular, and electrical standpoints. Here we discuss historical and contemporary aspects of pluripotent stem cell-based cardiac cell therapy, with an emphasis on recent preclinical studies with translational goals. PMID:24838687

  3. Studying the organization of DNA repair by single-cell and single-molecule imaging

    PubMed Central

    Uphoff, Stephan; Kapanidis, Achillefs N.

    2014-01-01

    DNA repair safeguards the genome against a diversity of DNA damaging agents. Although the mechanisms of many repair proteins have been examined separately in vitro, far less is known about the coordinated function of the whole repair machinery in vivo. Furthermore, single-cell studies indicate that DNA damage responses generate substantial variation in repair activities across cells. This review focuses on fluorescence imaging methods that offer a quantitative description of DNA repair in single cells by measuring protein concentrations, diffusion characteristics, localizations, interactions, and enzymatic rates. Emerging single-molecule and super-resolution microscopy methods now permit direct visualization of individual proteins and DNA repair events in vivo. We expect much can be learned about the organization of DNA repair by linking cell heterogeneity to mechanistic observations at the molecular level. PMID:24629485

  4. uv excision-repair gene transfer in Chinese hamster ovary (CHO) cells

    SciTech Connect

    MacInnes, M.A.; Bingham, J.M.; Strniste, G.F.; Thompson, L.H.

    1983-01-01

    uvc-sensitive mutants of CHO cells provide a model system for molecular studies of DNA repair. We present our recent results which show that these mutants are competent recipients for plasmid marker gene transfer and incorporation of a putative CHO repair gene. The applicability and advantages of this system for interspecies human repair gene identification are discussed.

  5. Cell-based therapy for traumatic brain injury.

    PubMed

    Gennai, S; Monsel, A; Hao, Q; Liu, J; Gudapati, V; Barbier, E L; Lee, J W

    2015-08-01

    Traumatic brain injury is a major economic burden to hospitals in terms of emergency department visits, hospitalizations, and utilization of intensive care units. Current guidelines for the management of severe traumatic brain injuries are primarily supportive, with an emphasis on surveillance (i.e. intracranial pressure) and preventive measures to reduce morbidity and mortality. There are no direct effective therapies available. Over the last fifteen years, pre-clinical studies in regenerative medicine utilizing cell-based therapy have generated enthusiasm as a possible treatment option for traumatic brain injury. In these studies, stem cells and progenitor cells were shown to migrate into the injured brain and proliferate, exerting protective effects through possible cell replacement, gene and protein transfer, and release of anti-inflammatory and growth factors. In this work, we reviewed the pathophysiological mechanisms of traumatic brain injury, the biological rationale for using stem cells and progenitor cells, and the results of clinical trials using cell-based therapy for traumatic brain injury. Although the benefits of cell-based therapy have been clearly demonstrated in pre-clinical studies, some questions remain regarding the biological mechanisms of repair and safety, dose, route and timing of cell delivery, which ultimately will determine its optimal clinical use.

  6. Angiogenic activity mediates bone repair from human pluripotent stem cell-derived osteogenic cells

    PubMed Central

    Zou, Li; Chen, Qingshan; Quanbeck, Zachary; Bechtold, Joan E.; Kaufman, Dan S.

    2016-01-01

    Human pluripotent stem cells provide a standardized resource for bone repair. However, criteria to determine which exogenous cells best heal orthopedic injuries remain poorly defined. We evaluated osteogenic progenitor cells derived from both human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs). Phenotypic and genotypic analyses demonstrated that these hESCs/hiPSCs are similar in their osteogenic differentiation efficiency and they generate osteogenic cells comparable to osteogenic cells derived from mesenchymal stromal cells (BM-MSCs). However, expression of angiogenic factors, such as vascular endothelial growth factor and basic fibroblast growth factor in these osteogenic progenitor cells are markedly different, suggesting distinct pro-angiogenic potential of these stem cell derivatives. Studies to repair a femur non-union fracture demonstrate only osteogenic progenitor cells with higher pro-angiogenic potential significantly enhance bone repair in vivo. Together, these studies highlight a key role of pro-angiogenic potential of transplanted osteogenic cells for effective cell-mediated bone repair. PMID:26980556

  7. Dystrophin gene replacement and gene repair therapy for Duchenne muscular dystrophy in 2016.

    PubMed

    Duan, Dongsheng

    2016-03-04

    After years of relentless efforts, gene therapy has now begun to deliver its therapeutic promise in several diseases. A number of gene therapy products have received regulatory approval in Europe and Asia. Duchenne muscular dystrophy (DMD) is an X-linked inherited lethal muscle disease. It is caused by mutations in the dystrophin gene. Replacing and/or repair the mutated dystrophin gene holds great promises to treated DMD at the genetic level. Last several years have evidenced significant developments in preclinical experimentations in murine and canine models of DMD. There has been a strong interest in moving these promising findings to clinical trials. In light of rapid progress in this field, the Parent Project Muscular Dystrophy (PPMD) recently interviewed me on the current status of DMD gene therapy. Here I summarized the interview with PPMD.

  8. Dystrophin Gene Replacement and Gene Repair Therapy for Duchenne Muscular Dystrophy in 2016: An Interview.

    PubMed

    Duan, Dongsheng

    2016-03-01

    After years of relentless efforts, gene therapy has now begun to deliver its therapeutic promise in several diseases. A number of gene therapy products have received regulatory approval in Europe and Asia. Duchenne muscular dystrophy (DMD) is an X-linked inherited lethal muscle disease. It is caused by mutations in the dystrophin gene. Replacing and/or repairing the mutated dystrophin gene holds great promises to treated DMD at the genetic level. Last several years have evidenced significant developments in preclinical experimentations in murine and canine models of DMD. There has been a strong interest in moving these promising findings to clinical trials. In light of rapid progress in this field, the Parent Project Muscular Dystrophy (PPMD) recently interviewed me on the current status of DMD gene therapy and readiness for clinical trials. Here I summarized the interview with PPMD.

  9. Dystrophin Gene Replacement and Gene Repair Therapy for Duchenne Muscular Dystrophy in 2016: An Interview

    PubMed Central

    Duan, Dongsheng

    2016-01-01

    After years of relentless efforts, gene therapy has now begun to deliver its therapeutic promise in several diseases. A number of gene therapy products have received regulatory approval in Europe and Asia. Duchenne muscular dystrophy (DMD) is an X-linked inherited lethal muscle disease. It is caused by mutations in the dystrophin gene. Replacing and/or repairing the mutated dystrophin gene holds great promises to treated DMD at the genetic level. Last several years have evidenced significant developments in preclinical experimentations in murine and canine models of DMD. There has been a strong interest in moving these promising findings to clinical trials. In light of rapid progress in this field, the Parent Project Muscular Dystrophy (PPMD) recently interviewed me on the current status of DMD gene therapy and readiness for clinical trials. Here I summarized the interview with PPMD. PMID:27003751

  10. The prognostic and predictive value of excision repair cross-complementation group 1 (ERCC1) protein in 1288 patients with head and neck squamous cell carcinoma treated with platinum-based therapy: a meta-analysis.

    PubMed

    Bišof, Vesna; Zajc Petranović, Matea; Rakušić, Zoran; Samardžić, Kristina Ruža; Juretić, Antonio

    2016-09-01

    Excision repair cross-complementation group 1 (ERCC1) protein has been extensively investigated as a prognostic and predictive factor for platinum-based treatment in head and neck squamous cell carcinoma (HNSCC) but with inconsistent results. We performed the present meta-analysis to better elucidate this issue in advanced HNSCC. A literature search was conducted using the PubMed and Web of Science databases. The inclusion criteria were head and neck cancer patients with platinum-based treatment and evaluation of the correlation between ERCC1 expression and clinical outcomes [objective response rate (ORR), progression-free survival (PFS), and overall survival (OS), both unadjusted and adjusted estimates]. In high vs. low pooled analyses, high ERCC1 expression was associated with unfavorable OS [hazard ratio (HR) = 1.95, 95 % confidence interval (CI) 1.18-3.21, p = 0.009], PFS (HR = 2.39, 95 % CI 1.74-3.28, p = 0.000) and ORR (odds ratio = 0.48, 95 % CI 0.23-0.98, p = 0.044). In the subgroup analysis of adjusted OS estimates, ERCC1 was a predictor of shorter survival in Asians (HR = 3.13, 95 % CI 2.09-4.70, p = 0.000) and Caucasians (HR = 2.02, 95 % CI 1.32-3.07, p = 0.001) but of longer survival in South Americans (HR = 0.17, 95 % CI 0.07-0.40, p = 0.000). Immunohistochemistry proved to be of predictive value irrespective of used antibody (p = 0.009). In the stratified analysis according to the tumor site, ERCC1 expression was associated with OS in nasopharyngeal cancer (HR = 2.72, 95 % CI 1.79-4.13, p = 0.000). ERCC1 has a potential to become predictive and prognostic factor enabling treatment tailoring in HNSCC patients.

  11. Embryonic Wound Healing: A Primer for Engineering Novel Therapies for Tissue Repair

    PubMed Central

    Degen, Katherine E.; Gourdie, Robert G.

    2014-01-01

    Scar is the default tissue repair used by the body in response to most injuries–a response that occurs in wounds ranging in seriousness from minor skin cuts to complete severance of the spinal cord. By contrast, before the third trimester of pregnancy embryonic mammals tend to heal without scarring due to a variety of mechanisms and factors that are uniquely in operation during development in utero. The goal of tissue engineering is to develop safe and clinically effective biological substitutes that restore, maintain, or improve tissue function in patients. This review provides a comparative overview of wound healing during development and maturation and seeks to provide a perspective on just how much the embryo may be able teach us in the engineering of new therapies for tissue repair. PMID:23109321

  12. American Society of Gene & Cell Therapy

    MedlinePlus

    ... Join ASGCT! Job Bank Donate Media The American Society of Gene & Cell Therapy The American Society of Gene & Cell Therapy is the primary professional membership organization for gene and cell therapy. The Society's members are scientists, physicians, patient advocates, and other ...

  13. [Cell therapy for type I diabete].

    PubMed

    Sokolova, I B

    2009-01-01

    Cell therapy is a modern and promising approach to type I diabetes mellitus treatment. Nowadays a wide range of cells is used in laboratory experiments and clinical studies, including allogeneic and xenogeneic cells of Langergance islets, bone marrow cells, haematopoietic stem cells, mesenchymal stem cells, and cord blood stem cells. Any type of the cells named could correct the status of the patients to a certain extent. However, full recovery after cell therapy has not been achieved yet.

  14. Transplanted human embryonic stem cells as biological 'catalysts' for tissue repair and regeneration.

    PubMed

    Heng, Boon Chin; Liu, Hua; Cao, Tong

    2005-01-01

    Human embryonic stem cells have tremendous potential in the newly emerging field of regenerative medicine. Recently, it was demonstrated that the rescue of lethal cardiac defects in Id knockout mutant mouse embryos was not due to the transplanted cells giving rise to functional new tissues within the defective embryonic heart. Instead, there is indirect evidence that the observed therapeutic effect was due to various secreted factors emanating from the transplanted cells. This therefore, introduces the exciting prospect of utilizing human embryonic stem cells as biological 'catalysts' to promote tissue repair and regeneration in transplantation therapy. However, the immunological barrier against allogenic transplantation, as well as the teratogenic potential of human embryonic stem cells poses major technical challenges. A possible strategy to overcome the immunological barrier may be to impose a temporary regimen of immunosuppressive drugs followed by their gradual withdrawal, once adequate tissue regeneration has been achieved. Other more novel alternatives include the use of microencapsulation to block interaction with the transplant recipient's immune system, and co-transplantation with bone marrow-derived mesenchymal stem cells, which have been demonstrated to possess immuno-suppressive properties. The teratogenic potential of human embryonic stem cells could possibly be alleviated by directing the differentiation of these cells to specific lineages prior to transplantation, or through mitotic inactivation (gamma irradiation or mitomycin C exposure). Co-transplantation with autologous adult stem cells may represent a novel strategy to further enhance the 'catalytic' effects of human embryonic stem cells. The various factors secreted by human embryonic stem cells could then have a concentrated localized effect on relatively large numbers of co-transplanted autologous adult stem cells, which may in turn lead to enhanced repair and regeneration of the damaged

  15. Lung Basal Stem Cells Rapidly Repair DNA Damage Using the Error-Prone Nonhomologous End-Joining Pathway

    PubMed Central

    Weeden, Clare E.; Chen, Yunshun; Ma, Stephen B.; Hu, Yifang; Ramm, Georg; Sutherland, Kate D.; Smyth, Gordon K.

    2017-01-01

    Lung squamous cell carcinoma (SqCC), the second most common subtype of lung cancer, is strongly associated with tobacco smoking and exhibits genomic instability. The cellular origins and molecular processes that contribute to SqCC formation are largely unexplored. Here we show that human basal stem cells (BSCs) isolated from heavy smokers proliferate extensively, whereas their alveolar progenitor cell counterparts have limited colony-forming capacity. We demonstrate that this difference arises in part because of the ability of BSCs to repair their DNA more efficiently than alveolar cells following ionizing radiation or chemical-induced DNA damage. Analysis of mice harbouring a mutation in the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a key enzyme in DNA damage repair by nonhomologous end joining (NHEJ), indicated that BSCs preferentially repair their DNA by this error-prone process. Interestingly, polyploidy, a phenomenon associated with genetically unstable cells, was only observed in the human BSC subset. Expression signature analysis indicated that BSCs are the likely cells of origin of human SqCC and that high levels of NHEJ genes in SqCC are correlated with increasing genomic instability. Hence, our results favour a model in which heavy smoking promotes proliferation of BSCs, and their predilection for error-prone NHEJ could lead to the high mutagenic burden that culminates in SqCC. Targeting DNA repair processes may therefore have a role in the prevention and therapy of SqCC. PMID:28125611

  16. Carriers in Cell-Based Therapies for Neurological Disorders

    PubMed Central

    Wong, Francisca S. Y.; Chan, Barbara P.; Lo, Amy C. Y.

    2014-01-01

    There is a pressing need for long-term neuroprotective and neuroregenerative therapies to promote full function recovery of injuries in the human nervous system resulting from trauma, stroke or degenerative diseases. Although cell-based therapies are promising in supporting repair and regeneration, direct introduction to the injury site is plagued by problems such as low transplanted cell survival rate, limited graft integration, immunorejection, and tumor formation. Neural tissue engineering offers an integrative and multifaceted approach to tackle these complex neurological disorders. Synergistic therapeutic effects can be obtained from combining customized biomaterial scaffolds with cell-based therapies. Current scaffold-facilitated cell transplantation strategies aim to achieve structural and functional rescue via offering a three-dimensional permissive and instructive environment for sustainable neuroactive factor production for prolonged periods and/or cell replacement at the target site. In this review, we intend to highlight important considerations in biomaterial selection and to review major biodegradable or non-biodegradable scaffolds used for cell transplantation to the central and peripheral nervous system in preclinical and clinical trials. Expanded knowledge in biomaterial properties and their prolonged interaction with transplanted and host cells have greatly expanded the possibilities for designing suitable carrier systems and the potential of cell therapies in the nervous system. PMID:24933636

  17. Enhanced infarct myocardium repair mediated by thermosensitive copolymer hydrogel-based stem cell transplantation

    PubMed Central

    Xia, Yu; Zhu, Kai; Lai, Hao; Lang, Meidong; Xiao, Yan; Lian, Sheng

    2015-01-01

    Mesenchymal stem cell (MSC) transplantation by intramyocardial injection has been proposed as a promising therapy strategy for cardiac repair after myocardium infarction. However, low retention and survival of grafted MSCs hinder its further application. In this study, copolymer with N-isopropylacrylamide/acrylic acid/2-hydroxylethyl methacrylate-poly(ɛ-caprolactone) ratio of 88:9.6:2.4 was bioconjugated with type I collagen to construct a novel injectable thermosensitive hydrogel. The injectable and biocompatible hydrogel-mediated MSC transplantation could enhance the grafted cell survival in the myocardium, which contributed to the increased neovascularization, decreased interstitial fibrosis, and ultimately improved heart function to a significantly greater degree than regular MSC transplantation. We suggest that this novel hydrogel has the potential for future stem cell transplantation. PMID:25432986

  18. Enhanced infarct myocardium repair mediated by thermosensitive copolymer hydrogel-based stem cell transplantation.

    PubMed

    Xia, Yu; Zhu, Kai; Lai, Hao; Lang, Meidong; Xiao, Yan; Lian, Sheng; Guo, Changfa; Wang, Chunsheng

    2015-05-01

    Mesenchymal stem cell (MSC) transplantation by intramyocardial injection has been proposed as a promising therapy strategy for cardiac repair after myocardium infarction. However, low retention and survival of grafted MSCs hinder its further application. In this study, copolymer with N-isopropylacrylamide/acrylic acid/2-hydroxylethyl methacrylate-poly(ɛ-caprolactone) ratio of 88:9.6:2.4 was bioconjugated with type I collagen to construct a novel injectable thermosensitive hydrogel. The injectable and biocompatible hydrogel-mediated MSC transplantation could enhance the grafted cell survival in the myocardium, which contributed to the increased neovascularization, decreased interstitial fibrosis, and ultimately improved heart function to a significantly greater degree than regular MSC transplantation. We suggest that this novel hydrogel has the potential for future stem cell transplantation.

  19. Novel therapies in small cell lung cancer

    PubMed Central

    Induru, Raghava; Jalal, Shadia I.

    2015-01-01

    Small cell lung cancer (SCLC) is an aggressive neuroendocrine tumor of the lung with a tendency to metastasize widely early in the course of the disease. The VA staging system classifies the disease into limited stage (LS) which is confined to one hemithorax and can be included into one radiation field or extensive stage (ES) which extends beyond one hemithorax. Current standard of care is concurrent chemoradiation for LS disease and chemotherapy alone for ES disease. Only a quarter of patients with LS disease will be cured with current standard treatments and majority of the patients ultimately succumb to their disease. A very complex genetic landscape of SCLC accounts for its resistance to conventional therapy and a high recurrence rate, however, at the same time this complexity can form the basis for effective targeted therapy for the disease. In recent years, several different therapeutic strategies and targeted agents have been under investigation for their potential role in SCLC. Several of them including EGFR TKIs, BCR-ABL TKIs, mTOR inhibitors, and VEGF inhibitors have been unsuccessful in showing a survival advantage in this disease. Several others including DNA repair inhibitors, cellular developmental pathway inhibitors, antibody drug conjugates (ADCs), as well as immune therapy with vaccines, immunomodulators, and immune checkpoint inhibitors are being tested. So far, none of these agents are approved for use in SCLC and the majority are in phase I/II clinical trials, with immune checkpoint inhibitors being the most promising therapeutic strategy. In this article, we will discuss these novel therapeutic agents and currently available data in SCLC. PMID:26629422

  20. Minimally Invasive Repair of Pectus Carinatum in Patients Unsuited to Bracing Therapy

    PubMed Central

    Suh, Jee-Won; Joo, Seok; Lee, Geun Dong; Haam, Seok Jin; Lee, Sungsoo

    2016-01-01

    Background We used an Abramson technique for minimally invasive repair of pectus carinatum in patients who preferred surgery to brace therapy, had been unsuccessfully treated via brace therapy, or were unsuitable for brace therapy because of a rigid chest wall. Methods Between July 2011 and May 2015, 16 patients with pectus carinatum underwent minimally invasive surgery. Results The mean age of the patients was 24.35±13.20 years (range, 14–57 years), and all patients were male. The percentage of excellent aesthetic results, as rated by the patients, was 37.5%, and the percentage of good results was 56.25%. The preoperative and postoperative Haller Index values were 2.01±0.19 (range, 1.60–2.31), and 2.22±0.19 (range, 1.87–2.50), respectively (p-value=0.01), and the median hospital stay was 7.09±2.91 days (range, 5–15 days). Only one patient experienced postoperative complications. Conclusion Minimally invasive repair is effective for the treatment of pectus carinatum, even in adult patients. PMID:27066432

  1. Sweat gland regeneration after burn injury: is stem cell therapy a new hope?

    PubMed

    Zhang, Cuiping; Chen, Yan; Fu, Xiaobing

    2015-05-01

    Stem cells are the seeds of tissue repair and regeneration and a promising source for novel therapies. The skin of patients with an extensive deep burn injury is repaired by a hypertrophic scar without regeneration of sweat glands and therefore loses the function of perspiration. Stem cell therapy provides the possibility of sweat gland regeneration. In particular, recent studies have reported the reprogramming of mesenchymal stromal cells into sweat gland-like (SGL) cells. We present an overview of recent researches into sweat gland regeneration with stem cells. Difficulties of sweat gland regeneration after deep burns have been elaborated. The advantage and disadvantage of several stem cell types in sweat gland regeneration have been discussed. Additionally, the possible mechanisms for reprogramming stem cells to SGL cells are summarized. A brief discussion on clinical application of stem cell-derived SGL cells is also presented. This review may possibly provide some implications for sweat gland regeneration.

  2. Cell and biomolecule delivery for tissue repair and regeneration in the central nervous system.

    PubMed

    Elliott Donaghue, Irja; Tam, Roger; Sefton, Michael V; Shoichet, Molly S

    2014-09-28

    Tissue engineering frequently involves cells and scaffolds to replace damaged or diseased tissue. It originated, in part, as a means of effecting the delivery of biomolecules such as insulin or neurotrophic factors, given that cells are constitutive producers of such therapeutic agents. Thus cell delivery is intrinsic to tissue engineering. Controlled release of biomolecules is also an important tool for enabling cell delivery since the biomolecules can enable cell engraftment, modulate inflammatory response or otherwise benefit the behavior of the delivered cells. We describe advances in cell and biomolecule delivery for tissue regeneration, with emphasis on the central nervous system (CNS). In the first section, the focus is on encapsulated cell therapy. In the second section, the focus is on biomolecule delivery in polymeric nano/microspheres and hydrogels for the nerve regeneration and endogenous cell stimulation. In the third section, the focus is on combination strategies of neural stem/progenitor cell or mesenchymal stem cell and biomolecule delivery for tissue regeneration and repair. In each section, the challenges and potential solutions associated with delivery to the CNS are highlighted.

  3. Low-level laser therapy on bone repair: is there any effect outside the irradiated field?

    PubMed

    Batista, Jonas Dantas; Sargenti-Neto, Sérgio; Dechichi, Paula; Rocha, Flaviana Soares; Pagnoncelli, Rogério Miranda

    2015-07-01

    The biological effects of local therapy with laser on bone repair have been well demonstrated; however, this possible effect on bone repair outside the irradiated field has not been evaluated. The aim of this study was to investigate the effect of low-level laser therapy (LLLT) (λ = 830 nm) on repair of surgical bone defects outside the irradiated field, in rats. Sixty Wistar rats were submitted to osteotomy on the left femur and randomly separated into four groups (n = 15): group I, control, bone defect only; group II, laser applied on the right femur (distant dose); group III, laser applied locally on the bone defect and also on the right femur (local and distant doses); and group IV, laser applied locally on the left femur (local dose). Laser groups received applications within a 48-h interval in one point per session of density energy (DE) = 210 J/cm(2), P = 50 mW, t = 120 s, and beam diameter of 0.028 cm. Five animals of each group were euthanized 7, 15, and 21 days after surgery. Histologic analysis in all groups showed new bone formation in the region of interest (ROI) at 7 days. After 15 days, bone remodeling with a decrease of bone neoformation in the marrow area was observed in all groups. After 21 days, advanced bone remodeling with new bone mostly located in the cortical area was observed. The histomorphometric analysis showed at 7 days a significant increase of bone formation in groups III and IV compared to groups I and II. At days 15 and 21, histomorphometric analysis showed no significant differences between them. Laser therapy presented a positive local biostimulative effect in the early stage of bone healing, but the LLLT effect was not observed a long distance from the evaluated area.

  4. The endoperoxide ascaridol shows strong differential cytotoxicity in nucleotide excision repair-deficient cells

    SciTech Connect

    Abbasi, Rashda; Efferth, Thomas; Kuhmann, Christine; Opatz, Till; Hao, Xiaojiang; Popanda, Odilia; Schmezer, Peter

    2012-03-15

    Targeting synthetic lethality in DNA repair pathways has become a promising anti-cancer strategy. However little is known about such interactions with regard to the nucleotide excision repair (NER) pathway. Therefore, cell lines with a defect in the NER genes ERCC6 or XPC and their normal counterparts were screened with 53 chemically defined phytochemicals isolated from plants used in traditional Chinese medicine for differential cytotoxic effects. The screening revealed 12 drugs that killed NER-deficient cells more efficiently than proficient cells. Five drugs were further analyzed for IC{sub 50} values, effects on cell cycle distribution, and induction of DNA damage. Ascaridol was the most effective compound with a difference of > 1000-fold in resistance between normal and NER-deficient cells (IC{sub 50} values for cells with deficiency in ERCC6: 0.15 μM, XPC: 0.18 μM, and normal cells: > 180 μM). NER-deficiency combined with ascaridol treatment led to G2/M-phase arrest, an increased percentage of subG1 cells, and a substantially higher DNA damage induction. These results were confirmed in a second set of NER-deficient and -proficient cell lines with isogenic background. Finally, ascaridol was characterized for its ability to generate oxidative DNA damage. The drug led to a dose-dependent increase in intracellular levels of reactive oxygen species at cytotoxic concentrations, but only NER-deficient cells showed a strongly induced amount of 8-oxodG sites. In summary, ascaridol is a cytotoxic and DNA-damaging compound which generates intracellular reactive oxidative intermediates and which selectively affects NER-deficient cells. This could provide a new therapeutic option to treat cancer cells with mutations in NER genes. -- Highlights: ► Thousand-fold higher Ascaridol activity in NER-deficient versus proficient cells. ► Impaired repair of Ascaridol-induced oxidative DNA damage in NER-deficient cells. ► Selective activity of Ascaridol opens new therapy

  5. Current stem cell delivery methods for myocardial repair.

    PubMed

    Sheng, Calvin C; Zhou, Li; Hao, Jijun

    2013-01-01

    Heart failure commonly results from an irreparable damage due to cardiovascular diseases (CVDs), the leading cause of morbidity and mortality in the United States. In recent years, the rapid advancements in stem cell research have garnered much praise for paving the way to novel therapies in reversing myocardial injuries. Cell types currently investigated for cellular delivery include embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and adult stem cell lineages such as skeletal myoblasts, bone-marrow-derived stem cells (BMSCs), mesenchymal stem cells (MSCs), and cardiac stem cells (CSCs). To engraft these cells into patients' damaged myocardium, a variety of approaches (intramyocardial, transendocardial, transcoronary, venous, intravenous, intracoronary artery and retrograde venous administrations and bioengineered tissue transplantation) have been developed and explored. In this paper, we will discuss the pros and cons of these delivery modalities, the current state of their therapeutic potentials, and a multifaceted evaluation of their reported clinical feasibility, safety, and efficacy. While the issues of optimal delivery approach, the best progenitor stem cell type, the most effective dose, and timing of administration remain to be addressed, we are highly optimistic that stem cell therapy will provide a clinically viable option for myocardial regeneration.

  6. Current focus of stem cell application in retinal repair

    PubMed Central

    Alonso-Alonso, María L; Srivastava, Girish K

    2015-01-01

    The relevance of retinal diseases, both in society’s economy and in the quality of people’s life who suffer with them, has made stem cell therapy an interesting topic for research. Embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs) and adipose derived mesenchymal stem cells (ADMSCs) are the focus in current endeavors as a source of different retinal cells, such as photoreceptors and retinal pigment epithelial cells. The aim is to apply them for cell replacement as an option for treating retinal diseases which so far are untreatable in their advanced stage. ESCs, despite the great potential for differentiation, have the dangerous risk of teratoma formation as well as ethical issues, which must be resolved before starting a clinical trial. iPSCs, like ESCs, are able to differentiate in to several types of retinal cells. However, the process to get them for personalized cell therapy has a high cost in terms of time and money. Researchers are working to resolve this since iPSCs seem to be a realistic option for treating retinal diseases. ADMSCs have the advantage that the procedures to obtain them are easier. Despite advancements in stem cell application, there are still several challenges that need to be overcome before transferring the research results to clinical application. This paper reviews recent research achievements of the applications of these three types of stem cells as well as clinical trials currently based on them. PMID:25914770

  7. Targeted DNA methylation by homology-directed repair in mammalian cells. Transcription reshapes methylation on the repaired gene.

    PubMed

    Morano, Annalisa; Angrisano, Tiziana; Russo, Giusi; Landi, Rosaria; Pezone, Antonio; Bartollino, Silvia; Zuchegna, Candida; Babbio, Federica; Bonapace, Ian Marc; Allen, Brittany; Muller, Mark T; Chiariotti, Lorenzo; Gottesman, Max E; Porcellini, Antonio; Avvedimento, Enrico V

    2014-01-01

    We report that homology-directed repair of a DNA double-strand break within a single copy Green Fluorescent Protein (GFP) gene in HeLa cells alters the methylation pattern at the site of recombination. DNA methyl transferase (DNMT)1, DNMT3a and two proteins that regulate methylation, Np95 and GADD45A, are recruited to the site of repair and are responsible for selective methylation of the promoter-distal segment of the repaired DNA. The initial methylation pattern of the locus is modified in a transcription-dependent fashion during the 15-20 days following repair, at which time no further changes in the methylation pattern occur. The variation in DNA modification generates stable clones with wide ranges of GFP expression. Collectively, our data indicate that somatic DNA methylation follows homologous repair and is subjected to remodeling by local transcription in a discrete time window during and after the damage. We propose that DNA methylation of repaired genes represents a DNA damage code and is source of variation of gene expression.

  8. Preventing over-resection by DNA2 helicase/nuclease suppresses repair defects in Fanconi anemia cells.

    PubMed

    Karanja, Kenneth K; Lee, Eu Han; Hendrickson, Eric A; Campbell, Judith L

    2014-01-01

    FANCD2 is required for the repair of DNA damage by the FA (Fanconi anemia) pathway, and, consequently, FANCD2-deficient cells are sensitive to compounds such as cisplatin and formaldehyde that induce DNA:DNA and DNA:protein crosslinks, respectively. The DNA2 helicase/nuclease is required for RNA/DNA flap removal from Okazaki fragments during DNA replication and for the resection of DSBs (double-strand breaks) during HDR (homology-directed repair) of replication stress-induced damage. A knockdown of DNA2 renders normal cells as sensitive to cisplatin (in the absence of EXO1) and to formaldehyde (even in the presence of EXO1) as FANCD2(-/-) cells. Surprisingly, however, the depletion of DNA2 in FANCD2-deficient cells rescues the sensitivity of FANCD2(-/-) cells to cisplatin and formaldehyde. We previously showed that the resection activity of DNA2 acts downstream of FANCD2 to insure HDR of the DSBs arising when replication forks encounter ICL (interstrand crosslink) damage. The suppression of FANCD2(-/-) by DNA2 knockdowns suggests that DNA2 and FANCD2 also have antagonistic roles: in the absence of FANCD2, DNA2 somehow corrupts repair. To demonstrate that DNA2 is deleterious to crosslink repair, we used psoralen-induced ICL damage to trigger the repair of a site-specific crosslink in a GFP reporter and observed that "over-resection" can account for reduced repair. Our work demonstrates that excessive resection can lead to genome instability and shows that strict regulatory processes have evolved to inhibit resection nucleases. The suppression of FANCD2(-/-) phenotypes by DNA2 depletion may have implications for FA therapies and for the use of ICL-inducing agents in chemotherapy.

  9. Preventing over-resection by DNA2 helicase/nuclease suppresses repair defects in Fanconi anemia cells

    PubMed Central

    Karanja, Kenneth K; Lee, Eu Han; Hendrickson, Eric A; Campbell, Judith L

    2014-01-01

    FANCD2 is required for the repair of DNA damage by the FA (Fanconi anemia) pathway, and, consequently, FANCD2-deficient cells are sensitive to compounds such as cisplatin and formaldehyde that induce DNA:DNA and DNA:protein crosslinks, respectively. The DNA2 helicase/nuclease is required for RNA/DNA flap removal from Okazaki fragments during DNA replication and for the resection of DSBs (double-strand breaks) during HDR (homology-directed repair) of replication stress-induced damage. A knockdown of DNA2 renders normal cells as sensitive to cisplatin (in the absence of EXO1) and to formaldehyde (even in the presence of EXO1) as FANCD2−/− cells. Surprisingly, however, the depletion of DNA2 in FANCD2-deficient cells rescues the sensitivity of FANCD2−/− cells to cisplatin and formaldehyde. We previously showed that the resection activity of DNA2 acts downstream of FANCD2 to insure HDR of the DSBs arising when replication forks encounter ICL (interstrand crosslink) damage. The suppression of FANCD2−/− by DNA2 knockdowns suggests that DNA2 and FANCD2 also have antagonistic roles: in the absence of FANCD2, DNA2 somehow corrupts repair. To demonstrate that DNA2 is deleterious to crosslink repair, we used psoralen-induced ICL damage to trigger the repair of a site-specific crosslink in a GFP reporter and observed that “over-resection” can account for reduced repair. Our work demonstrates that excessive resection can lead to genome instability and shows that strict regulatory processes have evolved to inhibit resection nucleases. The suppression of FANCD2−/− phenotypes by DNA2 depletion may have implications for FA therapies and for the use of ICL-inducing agents in chemotherapy. PMID:24626199

  10. A sensitive test for the detection of specific DSB repair defects in primary cells from breast cancer specimens.

    PubMed

    Keimling, Marlen; Kaur, Jatinder; Bagadi, Sarangadhara Appala Raju; Kreienberg, Rolf; Wiesmüller, Lisa; Ralhan, Ranju

    2008-08-01

    Increasing evidence indicates that breast cancer pathogenesis is linked with DNA double-strand break (DSB) repair dysfunction. This conclusion is based on advances in the study of functions of breast cancer susceptibility genes such as BRCA1 and BRCA2, on the identification of breast cancer-associated changes regarding the genetics, expression, and localization of multiple DSB repair factors, and on observations indicating enhanced radiation-induced chromosomal damage in cells from predisposed individuals and sporadic breast cancer patients. In this pilot study, we describe a sensitive method for the analysis of DSB repair functions in mammary carcinomas. Using this method we firstly document alterations in pathway-specific DSB repair activities in primary cells originating from familial as well as sporadic breast cancer. In particular, we identified increases in the mutagenic nonhomologous end joining and single-strand annealing mechanisms in sporadic breast cancers with wild-type BRCA1 and BRCA2, and, thus, similar phenotypes to tumors with mutant alleles of BRCA1 and BRCA2. This suggests that detection of error-prone DSB repair activities may be useful to extend the limits of genotypic characterization of high-risk susceptibility genes. This method may, therefore, serve as a marker for breast cancer risk assessment and, even more importantly, for the prediction of responsiveness to targeted therapies such as to inhibitors of poly(ADP-ribose)polymerase (PARP1).

  11. Stem cell directed gene therapy.

    PubMed

    Engel, B C; Kohn, D B

    1999-05-01

    A potential therapeutic approach to HIV-1 infection is the genetic modification of cells of a patient to make them resistant to HIV-1. Hematopoietic stem cells are an attractive target for gene therapy of AIDS because of their ability to generate a broad repertoire of mature T lymphocytes, as well as the monocytic cells (macrophages, dendritic cells and microglia) which are also involved in HIV-1 pathogenesis. A number of synthetic "anti-HIV-1 genes" have been developed which inhibit HIV-1 replication. However, current methods for gene transfer into human hematopoietic stem cells, using retroviral vectors derived from the Moloney murine leukemia virus, have been minimally effective. Clinical trials performed to date in which hematopoietic cells from HIV-1-positive patients have been transduced with retroviral vectors and then reinfused have produced low to undetectable levels of gene-containing peripheral blood leukocytes. New vector delivery systems, such as lentiviral vectors, need to be developed to ensure efficient gene transfer and persistent transgene expression to provide life-long resistance to the cells targeted by HIV-1.

  12. Non-homologous DNA end joining repair in normal and leukemic cells depends on the substrate ends.

    PubMed

    Pastwa, Elzbieta; Poplawski, Tomasz; Czechowska, Agnieszka; Malinowski, Mariusz; Blasiak, Janusz

    2005-01-01

    Double-strand breaks (DSBs) are the most serious DNA damage which, if unrepaired or misrepaired, may lead to cell death, genomic instability or cancer transformation. In human cells they can be repaired mainly by non-homologous DNA end joining (NHEJ). The efficacy of NHEJ pathway was examined in normal human lymphocytes and K562 myeloid leukemic cells expressing the BCR/ABL oncogenic tyrosine kinase activity and lacking p53 tumor suppressor protein. In our studies we employed a simple and rapid in vitro DSB end joining assay based on fluorescent detection of repair products. Normal and cancer cells were able to repair DNA damage caused by restriction endonucleases, but the efficiency of the end joining was dependent on the type of cells and the structure of DNA ends. K562 cells displayed decreased NHEJ activity in comparison to normal cells for 5' complementary DNA overhang. For blunt-ended DNA there was no significant difference in end joining activity. Both kinds of cells were found about 10-fold more efficient for joining DNA substrates with compatible 5' overhangs than those with blunt ends. Our recent findings have shown that stimulation of DNA repair could be involved in the drug resistance of BCR/ABL-positive cells in anticancer therapy. For the first time the role of STI571 was investigated, a specific inhibitor of BCR/ABL oncogenic protein approved for leukemia treatment in the NHEJ pathway. Surprisingly, STI571 did not change the response of BCR/ABL-positive K562 cells in terms of NHEJ for both complementary and blunt ends. Our results suggest that the various responses of the cells to DNA damage via NHEJ can be correlated with the differences in the genetic constitution of human normal and cancer cells. However, the role of NHEJ in anticancer drug resistance in BCR/ABL-positive cells is questionable.

  13. Biological significance of domain-oriented DNA repair in xeroderma pigmentosum cells

    SciTech Connect

    Kantor, G.J.; Elking, C.F.

    1988-02-15

    The patterns (domain oriented versus a random location) and amounts of DNA excision repair, determined by standard density gradient techniques and sedimentation properties of partially repaired and UV-endonuclease-digested DNA in alkaline sucrose gradients, are reported for UV (254 nm)-irradiated nondividing xeroderma pigmentosum complementation group C or A (XP-C, XP-A) and normal cells. Repair synthesis in relatively UV-resistant XP-C (XP4RO) cells is domain oriented and limited (10% of normal values) while it is randomly located and not as limited in more sensitive XP-A (XP8LO) cells. Thus, greater UV resistance is associated with a very limited but domain-oriented pattern of repair. In XP-C cells, both total and domain-oriented repair syntheses, while limited, increase with UV dose and plateau at about 15-20 J/m2, as observed for normal cells. We suggest that repair in XP-C is limited at the lower UV doses (less than 15-20 J/m2) by substrate levels in specific chromatin domains and not by availability of essential enzymes for domain-oriented repair. In contrast, the XP-A strain XP8LO exhibits normal repair activities for doses up to 5 J/m2 and limited repair at higher doses, indicating that repair occurs through normal pathways that are limited by reduced availability of an essential enzyme.

  14. Effect of low-level laser therapy on repair of the bone compromised by radiotherapy.

    PubMed

    Batista, Jonas D; Zanetta-Barbosa, Darceny; Cardoso, Sérgio V; Dechichi, Paula; Rocha, Flaviana S; Pagnoncelli, Rogério M

    2014-11-01

    Radiotherapy (RDT) is commonly used for cancer treatment, but high doses of ionizing radiation can directly affect healthy tissues. Positive biological effects of low-level laser therapy (LLLT) on bone repair have been demonstrated; however, this effect on surgical defects of bone previously compromised by radiotherapy has not been evaluated. The aim of this study was to investigate the influence of LLLT (λ = 830 nm) in femur repair after ionizing radiation. Twenty Wistar rats were divided into four groups: control group (GC, n = 5) creation of bone defects (BDs) only; laser group (GL), with BD and LLLT (n = 5); radiotherapy group (GR), submitted to RDT and BD (n = 5); and radiotherapy and laser group (GRL), submitted to RDT, BD, and LLLT (n = 5). GL and GRL received punctual laser application (DE = 210 J/cm(2), P = 50 mW, t = 120 s, and beam diameter of 0.04 cm(2)) immediately after surgery, with 48-h interval during 7 days. Animals were euthanized at 7 days after surgery, and bone sections were evaluated morphometrically with conventional microscopy. Bone repair was only observed in nonirradiated bone, with significant improvement in GL in comparison to GC. GR and GRL did not present any bone neoformation. The result demonstrated a positive local biostimulative effect of LLLT in normal bone. However, LLLT was not able to revert the bone metabolic damage due to ionizing radiation.

  15. Biologicals and Fetal Cell Therapy for Wound and Scar Management

    PubMed Central

    Hirt-Burri, Nathalie; Ramelet, Albert-Adrien; Raffoul, Wassim; de Buys Roessingh, Anthony; Scaletta, Corinne; Pioletti, Dominique; Applegate, Lee Ann

    2011-01-01

    Few biopharmaceutical preparations developed from biologicals are available for tissue regeneration and scar management. When developing biological treatments with cellular therapy, selection of cell types and establishment of consistent cell banks are crucial steps in whole-cell bioprocessing. Various cell types have been used in treatment of wounds to reduce scar to date including autolog and allogenic skin cells, platelets, placenta, and amniotic extracts. Experience with fetal cells show that they may provide an interesting cell choice due to facility of outscaling and known properties for wound healing without scar. Differential gene profiling has helped to point to potential indicators of repair which include cell adhesion, extracellular matrix, cytokines, growth factors, and development. Safety has been evidenced in Phase I and II clinical fetal cell use for burn and wound treatments with different cell delivery systems. We present herein that fetal cells present technical and therapeutic advantages compared to other cell types for effective cell-based therapy for wound and scar management. PMID:22363853

  16. DNA Repair in Human Cells Exposed to Combinations of Carcinogenic Agents

    SciTech Connect

    Setlow, R. B.; Ahmed, F. E.

    1980-01-01

    Normal human and XP2 fibroblasts were treated with UV plus UV-mimetic chemicals. The UV dose used was sufficient to saturate the UV excision repair system. Excision repair after combined treatments was estimated by unscheduled DNA synthesis, BrdUrd photolysis, and the loss of sites sensitive to a UV specific endonuclease. Since the repair of damage from UV and its mimetics is coordinately controlled we expected that there would be similar rate-limiting steps in the repair of UV and chemical damage and that after a combined treatment the total amount of repair would be the same as from UV or the chemicals separately. The expectation was not fulfilled. In normal cells repair after a combined treatment was additive whereas in XP cells repair after a combined treatment was usually less than after either agent separately. The chemicals tested were AAAF, DMBA-epoxide, 4NQO, and ICR-170.

  17. Regulation of DNA repair in serum-stimulated xeroderma pigmentosum cells

    PubMed Central

    1984-01-01

    The regulation of DNA repair during serum stimulation of quiescent cells was examined in normal human cells, in fibroblasts from three xeroderma pigmentosum complementation groups (A, C, and D), in xeroderma pigmentosum variant cells, and in ataxia telangiectasia cells. The regulation of nucleotide excision repair was examined by exposing cells to ultraviolet irradiation at discrete intervals after cell stimulation. Similarly, base excision repair was quantitated after exposure to methylmethane sulfonate. WI-38 normal human diploid fibroblasts, xeroderma pigmentosum variant cells, as well as ataxia telangiectasia cells enhanced their capacity for both nucleotide excision repair and for base excision repair prior to their enhancement of DNA synthesis. Further, in each cell strain, the base excision repair enzyme uracil DNA glycosylase was increased prior to the induction of DNA polymerase using the identical cells to quantitate each activity. In contrast, each of the three xeroderma complementation groups that were examined failed to increase their capacity for nucleotide excision repair above basal levels at any interval examined. This result was observed using either unscheduled DNA synthesis in the presence of 10 mM hydroxyurea or using repair replication in the absence of hydroxyurea to quantitate DNA repair. However, each of the three complementation groups normally regulated the enhancement of base excision repair after methylmethane sulfonate exposure and each induced the uracil DNA glycosylase prior to DNA synthesis. These results suggest that there may be a relationship between the sensitivity of xeroderma pigmentosum cells from each complementation group to specific DNA damaging agents and their inability to regulate nucleotide excision repair during cell stimulation. PMID:6480691

  18. Loss of CtIP disturbs homologous recombination repair and sensitizes breast cancer cells to PARP inhibitors.

    PubMed

    Wang, Junhui; Ding, Qianshan; Fujimori, Hiroaki; Motegi, Akira; Miki, Yoshio; Masutani, Mitsuko

    2016-02-16

    Breast cancer is one of the leading causes of death worldwide, and therefore, new and improved approaches for the treatment of breast cancer are desperately needed. CtIP (RBBP8) is a multifunctional protein that is involved in various cellular functions, including transcription, DNA replication, DNA repair and the G1 and G2 cell cycle checkpoints. CtIP plays an important role in homologous recombination repair by interacting with tumor suppressor protein BRCA1. Here, we analyzed the expression profile of CtIP by data mining using published microarray data sets. We found that CtIP expression is frequently decreased in breast cancer patients, and the patient group with low-expressing CtIP mRNA is associated with a significantly lower survival rate. The knockdown of CtIP in breast cancer MCF7 cells reduced Rad51 foci numbers and enhanced f H2AX foci formation after f-irradiation, suggesting that deficiency of CtIP decreases homologous recombination repair and delays DNA double strand break repair. To explore the effect of CtIP on PARP inhibitor therapy for breast cancer, CtIP-depleted MCF7 cells were treated with PARP inhibitor olaparib (AZD2281) or veliparib (ABT-888). As in BRCA mutated cells, PARP inhibitors showed cytotoxicity to CtIP-depleted cells by preventing cells from repairing DNA damage, leading to decreased cell viability. Further, a xenograft tumor model in mice with MCF7 cells demonstrated significantly increased sensitivity towards PARP inhibition under CtIP deficiency. In summary, this study shows that low level of CtIP expression is associated with poor prognosis in breast cancer, and provides a rationale for establishing CtIP expression as a biomarker of PARP inhibitor response, and consequently offers novel therapeutic options for a significant subset of patients.

  19. [Cell transplant and regenerative stem cell therapy].

    PubMed

    Prosper, F

    2008-01-01

    The derivation of the first human embryonic stem cell lines as well as the notion of the unexpected plasticity and potential of the adult stem cells has significantly impacted the biomedical research. Many of the tissues long believe to lack any regenerative capacity has demonstrated otherwise. Patients alike physicians expectations for treatment of incurable diseases have also fuelled this field and in occasions have led to unrealistic expectations. In the next pages I review some of the tissue specific stem cells that have been used either in preclinical models or even in clinical research. Despite the effort of numerous investigators, more questions that answers remain in the field of cell therapy and only careful and independent -not biased- research will allow us to translate some of this findings into clinical application.

  20. Repair, regenerative and supportive therapies of the annulus fibrosus: achievements and challenges

    PubMed Central

    Bron, Johannes Leendert; Helder, Marco N.; Meisel, Hans-Jorg; Van Royen, Barend J.

    2008-01-01

    Lumbar discectomy is a very effective therapy for neurological decompression in patients suffering from sciatica due to hernia nuclei pulposus. However, high recurrence rates and persisting post-operative low back pain in these patients require serious attention. In the past decade, tissue engineering strategies have been developed mainly targeted to the regeneration of the nucleus pulposus (NP) of the intervertebral disc. Accompanying techniques that deal with the damaged annulus fibrous are now increasingly recognised as mandatory in order to prevent re-herniation to increase the potential of NP repair and to confine NP replacement therapies. In the current review, the requirements, achievements and challenges in this quickly emerging field of research are discussed. PMID:19104850

  1. Stem cells, cell therapies, and bioengineering in lung biology and diseases. Comprehensive review of the recent literature 2010-2012.

    PubMed

    Weiss, Daniel J

    2013-10-01

    A conference, "Stem Cells and Cell Therapies in Lung Biology and Lung Diseases," was held July 25 to 28, 2011 at the University of Vermont to review the current understanding of the role of stem and progenitor cells in lung repair after injury and to review the current status of cell therapy and ex vivo bioengineering approaches for lung diseases. These are rapidly expanding areas of study that provide further insight into and challenge traditional views of mechanisms of lung repair after injury and pathogenesis of several lung diseases. The goals of the conference were to summarize the current state of the field, to discuss and debate current controversies, and to identify future research directions and opportunities for basic and translational research in cell-based therapies for lung diseases. The goal of this article, which accompanies the formal conference report, is to provide a comprehensive review of the published literature in lung regenerative medicine from the last conference report through December 2012.

  2. Mesenchymal Stem Cells and Articular Cartilage Repair: Clinical Studies and Future Direction

    PubMed Central

    Punwar, Shahid; Khan, Wasim S

    2011-01-01

    Cartilage is frequently injured but shows little capacity for repair. Current treatment options include the use of procedures that stimulate repair through the stimulation of subchondral bone marrow and result in the formation of fibrocartilage. There is considerable interest in the use of cell-based treatment strategies and there are limited studies describing the use of mesenchymal stem cells for cartilage repair with promising early results. This paper reviews the current treatment strategies for articular cartilage, describes use of mesenchymal stem cells for articular cartilage repair along with the results of clinical studies, and describes the future direction that these strategies are likely to take. PMID:21886696

  3. Hematopoietic myeloid cell differentiation diminishes nucleotide excision repair.

    PubMed

    Aoki, Yuki; Sato, Ayako; Mizutani, Shuki; Takagi, Masatoshi

    2014-09-01

    Myeloid cell differentiation is the process by which stem cells develop into mature monocytes or granulocytes. This process is achieved by the sequential activation of variety of genes. Disruption of this process can result in immunodeficiency, bone marrow failure syndrome, or leukemia. Acute promyelocytic leukemia (APL) is characterized by the t(15;17) translocation and can be treated by a combination of all-trans retinoic acid (ATRA) and anthracycline. This treatment can induce leukemic cell differentiation, leading to extremely high remission rates. XAB2, a molecule involved in nucleotide excision repair (NER), is downregulated during granulocyte differentiation and shows reduced expression in NB4 APL-derived cells in vitro. Differentiation of APL by ATRA treatment reduced XAB2 expression levels in vivo. These observations suggest that cellular differentiation is associated with reduced NER activity and provides new insights into combined differentiation induction. NB4 cells were more susceptible than the immature myeloid leukemic cell lines, Kasumi-3 and Kasumi-1, to the DNA interstrand crosslinking agent cisplatin.

  4. DNA repair and replication links to pluripotency and differentiation capacity of pig iPS cells

    PubMed Central

    Song, Lipu; Fan, Anran; Zhang, Sheng; Wang, Jianyu; Fan, Nana; Liu, Na; Ye, Xiaoying; Fu, Haifeng; Zhou, Zhongcheng; Wang, Yong; Wei, Hong; Liu, Zhonghua; Li, Ziyi; Lai, Liangxue; Wang, Xumin; Liu, Lin

    2017-01-01

    Pigs are proposed to be suitable large animal models for test of the efficacy and safety of induced pluripotent stem cells (iPSCs) for stem cell therapy, but authentic pig ES/iPS cell lines with germline competence are rarely produced. The pathways or signaling underlying the defective competent pig iPSCs remain poorly understood. By improving induction conditions using various small chemicals, we generated pig iPSCs that exhibited high pluripotency and differentiation capacity that can contribute to chimeras. However, their potency was reduced with increasing passages by teratoma formation test, and correlated with declined expression levels of Rex1, an important marker for naïve state. By RNA-sequencing analysis, genes related to WNT signaling were upregulated and MAPK signaling and TGFβ pathways downregulated in pig iPSCs compared to fibroblasts, but they were abnormally expressed during passages. Notably, pathways involving in DNA repair and replication were upregulated at early passage, but downregulated in iPSCs during prolonged passage in cluster with fibroblasts. Our data suggests that reduced DNA repair and replication capacity links to the instability of pig iPSCs. Targeting these pathways may facilitate generation of truly pluripotent pig iPSCs, with implication in translational studies. PMID:28253351

  5. Adoptive Cell Therapies for Glioblastoma

    PubMed Central

    Bielamowicz, Kevin; Khawja, Shumaila; Ahmed, Nabil

    2013-01-01

    Glioblastoma (GBM) is the most common and most aggressive primary brain malignancy and, as it stands, is virtually incurable. With the current standard of care, maximum feasible surgical resection followed by radical radiotherapy and adjuvant temozolomide, survival rates are at a median of 14.6 months from diagnosis in molecularly unselected patients (1). Collectively, the current knowledge suggests that the continued tumor growth and survival is in part due to failure to mount an effective immune response. While this tolerance is subtended by the tumor being utterly “self,” it is to a great extent due to local and systemic immune compromise mediated by the tumor. Different cell modalities including lymphokine-activated killer cells, natural killer cells, cytotoxic T lymphocytes, and transgenic chimeric antigen receptor or αβ T cell receptor grafted T cells are being explored to recover and or redirect the specificity of the cellular arm of the immune system toward the tumor complex. Promising phase I/II trials of such modalities have shown early indications of potential efficacy while maintaining a favorable toxicity profile. Efficacy will need to be formally tested in phase II/III clinical trials. Given the high morbidity and mortality of GBM, it is imperative to further investigate and possibly integrate such novel cell-based therapies into the current standards-of-care and herein we collectively assess and critique the state-of-the-knowledge pertaining to these efforts. PMID:24273748

  6. Exon 32 Skipping of Dysferlin Rescues Membrane Repair in Patients’ Cells

    PubMed Central

    Barthélémy, Florian; Blouin, Cédric; Wein, Nicolas; Mouly, Vincent; Courrier, Sébastien; Dionnet, Eugénie; Kergourlay, Virginie; Mathieu, Yves; Garcia, Luis; Butler-Browne, Gillian; Lamaze, Christophe; Lévy, Nicolas; Krahn, Martin; Bartoli, Marc

    2015-01-01

    Abstract Dysferlinopathies are a family of disabling muscular dystrophies with LGMD2B and Miyoshi myopathy as the main phenotypes. They are associated with molecular defects in DYSF, which encodes dysferlin, a key player in sarcolemmal homeostasis. Previous investigations have suggested that exon skipping may be a promising therapy for a subset of patients with dysferlinopathies. Such an approach aims to rescue functional proteins when targeting modular proteins and specific tissues. We sought to evaluate the dysferlin functional recovery following exon 32 skipping in the cells of affected patients. Exon skipping efficacy was characterized at several levels by use of in vitro myotube formation assays and quantitative membrane repair and recovery tests. Data obtained from these assessments confirmed that dysferlin function is rescued by quasi-dysferlin expression in treated patient cells, supporting the case for a therapeutic antisense-based trial in a subset of dysferlin-deficient patients. PMID:27858744

  7. The sulfated polysaccharide fucoidan rescues senescence of endothelial colony-forming cells for ischemic repair.

    PubMed

    Lee, Jun Hee; Lee, Sang Hun; Choi, Sung Hyun; Asahara, Takayuki; Kwon, Sang-Mo

    2015-06-01

    The efficacy of cell therapy using endothelial colony-forming cells (ECFCs) in the treatment of ischemia is limited by the replicative senescence of isolated ECFCs in vitro. Such senescence must therefore be overcome in order for such cell therapies to be clinically applicable. This study aimed to investigate the potential of sulfated polysaccharide fucoidan to rescue ECFCs from cellular senescence and to improve in vivo vascular repair by ECFCs. Fucoidan-preconditioning of senescent ECFCs was shown by flow cytometry to restore the expression of functional ECFC surface markers (CD34, c-Kit, VEGFR2, and CXCR4) and stimulate the in vitro tube formation capacity of ECFCs. Fucoidan also promoted the expression of cell cycle-associated proteins (cyclin E, Cdk2, cyclin D1, and Cdk4) in senescent ECFCs, significantly reversed cellular senescence, and increased the proliferation of ECFCs via the FAK, Akt, and ERK signaling pathways. Fucoidan was found to enhance the survival, proliferation, incorporation, and endothelial differentiation of senescent ECFCs transplanted in ischemic tissues in a murine hind limb ischemia model. Moreover, ECFC-induced functional recovery and limb salvage were markedly improved by fucoidan pretreatment of ECFCs. To our knowledge, the findings of our study are the first to demonstrate that fucoidan enhances the neovasculogenic potential of ECFCs by rescuing them from replicative cellular senescence. Pretreatment of ECFCs with fucoidan may thus provide a novel strategy for the application of senescent stem cells to therapeutic neovascularization.

  8. [Controversies in the therapy of rotator cuff tears. Operative or nonoperative treatment, open or arthroscopic repair?].

    PubMed

    Lorbach, O

    2016-02-01

    Rotator cuff tears are a common cause of shoulder pain that may lead to severe impairment of shoulder function with significant limitation of the quality of life. Furthermore, they are associated with high direct and indirect costs.Conservative therapy and various surgical procedures for rotator cuff repair are all possible treatment options. Therefore, the correct treatment for a symptomatic rotator cuff tear is important.The conservative therapy may be considered as an alternative treatment option for a symptomatic rotator cuff tear in patients with small or incomplete tears with no fatty atrophy or tendon retraction, with only slight pain, and in older patients with few functional demands. Surgical treatment is recommended after failed conservative treatment lasting 3-6 months, with the corresponding psychological strain. Moreover, surgical treatment should be considered as a primary treatment option for a symptomatic rotator cuff tear in young patients with high functional demands, patients with a high level of physical strain in their jobs, large tears, and tears where there is already significant muscle atrophy or tendon retraction.Arthroscopic treatment is considered to be the gold standard because of the better cosmetic results and treatment of concomitant pathological conditions, the lower levels of postoperative pain, the potentially lower risk of shoulder stiffness, and more focused adhesiolysis. However, arthroscopy does not improve clinical results. Because of the current financial situation, however, open rotator cuff repair is still a viable alternative.

  9. Bisdemethoxycurcumin induces DNA damage and inhibits DNA repair associated protein expressions in NCI-H460 human lung cancer cells.

    PubMed

    Yu, Chien-Chih; Yang, Su-Tso; Huang, Wen-Wen; Peng, Shu-Fen; Huang, An-Cheng; Tang, Nou-Ying; Liu, Hsin-Chung; Yang, Mei-Due; Lai, Kuang-Chi; Chung, Jing-Gung

    2015-08-30

    Nonsmall cell lung carcinoma (NSCLC) is a devastating primary lung tumor resistant to conventional therapies. Bisdemethoxycurcumin (BDMC) is one of curcumin derivate from Turmeric and has been shown to induce NSCLC cell death. Although there is one report to show BDMC induced DNA double strand breaks, however, no available information to show BDMC induced DNA damage action with inhibited DNA repair protein in lung cancer cells in detail. In this study, we tested BDMC-induced DNA damage and condensation in NCI-H460 cells by using Comet assay and DAPI staining examinations, respectively and we found BDMC induced DNA damage and condension. Western blotting was used to examine the effects of BDMC on protein expression associated with DNA damage and repair and results indicated that BDMC suppressed the protein levels associated with DNA damage and repair, such as 14-3-3σ (an important checkpoint keeper of DDR), O6-methylguanine-DNA methyltransferase, DNA repair proteins breast cancer 1, early onset, mediator of DNA damage checkpoint 1 but activate phosphorylated p53 and p-H2A.X (phospho Ser140) in NCI-H460 cells. Confocal laser systems microscopy was used for examining the protein translocation and results show that BDMC increased the translocation of p-p53 and p-H2A.X (phospho Ser140) from cytosol to nuclei in NCI-H460 cells. In conclusion, BDMC induced DNA damage and condension and affect DNA repair proteins in NCI-H460 cells in vitro. © 2015 Wiley Periodicals, Inc. Environ Toxicol, 2015.

  10. Progenitor Cells for Arterial Repair: Incremental Advancements towards Therapeutic Reality

    PubMed Central

    Simard, Trevor; Jung, Richard G.; Motazedian, Pouya; Di Santo, Pietro; Ramirez, F. Daniel; Russo, Juan J.; Labinaz, Alisha; Yousef, Altayyeb; Anantharam, Brijesh; Pourdjabbar, Ali

    2017-01-01

    Coronary revascularization remains the standard treatment for obstructive coronary artery disease and can be accomplished by either percutaneous coronary intervention (PCI) or coronary artery bypass graft surgery. Considerable advances have rendered PCI the most common form of revascularization and improved clinical outcomes. However, numerous challenges to modern PCI remain, namely, in-stent restenosis and stent thrombosis, underscoring the importance of understanding the vessel wall response to injury to identify targets for intervention. Among recent promising discoveries, endothelial progenitor cells (EPCs) have garnered considerable interest given an increasing appreciation of their role in vascular homeostasis and their ability to promote vascular repair after stent placement. Circulating EPC numbers have been inversely correlated with cardiovascular risk, while administration of EPCs in humans has demonstrated improved clinical outcomes. Despite these encouraging results, however, advancing EPCs as a therapeutic modality has been hampered by a fundamental roadblock: what constitutes an EPC? We review current definitions and sources of EPCs as well as the proposed mechanisms of EPC-mediated vascular repair. Additionally, we discuss the current state of EPCs as therapeutic agents, focusing on endogenous augmentation and transplantation. PMID:28232850

  11. Pluripotent Stem Cell Derived Cardiac Cells for Myocardial Repair.

    PubMed

    Zhu, Wuqiang; Gao, Ling; Zhang, Jianyi

    2017-02-03

    Human induced pluripotent stem cells (hiPSCs) must be fully differentiated into specific cell types before administration, but conventional protocols for differentiating hiPSCs into cardiomyocytes (hiPSC-CMs), endothelial cells (hiPSC-ECs), and smooth muscle cells (SMCs) are often limited by low yield, purity, and/or poor phenotypic stability. Here, we present novel protocols for generating hiPSC-CMs, -ECs, and -SMCs that are substantially more efficient than conventional methods, as well as a method for combining cell injection with a cytokine-containing patch created over the site of administration. The patch improves both the retention of the injected cells, by sealing the needle track to prevent the cells from being squeezed out of the myocardium, and cell survival, by releasing insulin-like growth factor (IGF) over an extended period. In a swine model of myocardial ischemia-reperfusion injury, the rate of engraftment was more than two-fold greater when the cells were administered with the cytokine-containing patch comparing to the cells without patch, and treatment with both the cells and the patch, but not with the cells alone, was associated with significant improvements in cardiac function and infarct size.

  12. Biphasic nanofibrous constructs with seeded cell layers for osteochondral repair.

    PubMed

    Jin, Guang-Zhen; Kim, Jung-Ju; Park, Jeong-Hui; Seo, Seog-Jin; Kim, Joong-Hyun; Lee, Eun-Jung; Kim, Hae-Won

    2014-11-01

    Biphasic scaffolds have gained increasing attention for the regeneration of osteochondral interfacial tissue because they are expected to effectively define the interfacial structure of tissue that comprises stratified cartilage with a degree of calcification. Here, we propose a biphasic nanofiber construct made of poly(lactide-co-caprolactone) (PLCL) and its mineralized form (mPLCL) populated with cells. Primary rat articular chondrocytes (ACs) and bone marrow-derived mesenchymal stem cells (MSCs) were cultured on the layers of bare PLCL and mPLCL nanofibers, respectively, for 7 days, and the biphasic cell-nanofiber construct was investigated at 4 weeks after implantation into nude mice. Before implantation, the ACs and MSCs grown on each layer of PLCL and mPLCL nanofibers exhibited phenotypes typical of chondrocytes and osteoblasts, respectively, under proper culture conditions, as analyzed by electron microscopy, histological staining, cell growth kinetics, and real-time polymerase chain reaction. The biphasic constructs also showed the development of a possible formation of cartilage and bone tissue in vivo. Results demonstrated that the cell-laden biphasic nanofiber constructs may be useful for the repair of osteochondral interfacial tissue structure.

  13. Fibrin patch-based insulin-like growth factor-1 gene-modified stem cell transplantation repairs ischemic myocardium

    PubMed Central

    Li, Jun; Zhu, Kai; Yang, Shan; Wang, Yulin; Guo, Changfa; Yin, Kanhua; Wang, Chunsheng

    2015-01-01

    Bone marrow mesenchymal stem cells (BMSCs), tissue-engineered cardiac patch, and therapeutic gene have all been proposed as promising therapy strategies for cardiac repair after myocardial infarction. In our study, BMSCs were modified with insulin-like growth factor-1 (IGF-1) gene, loaded into a fibrin patch, and then transplanted into a porcine model of ischemia/reperfusion (I/R) myocardium injury. The results demonstrated that IGF-1 gene overexpression could promote proliferation of endothelial cells and cardiomyocyte-like differentiation of BMSCs in vitro. Four weeks after transplantation of fibrin patch loaded with gene-modified BMSCs, IGF-1 overexpression could successfully promote angiogenesis, inhibit remodeling, increase grafted cell survival and reduce apoptosis. In conclusion, the integrated strategy, which combined fibrin patch with IGF-1 gene modified BMSCs, could promote the histological cardiac repair for a clinically relevant porcine model of I/R myocardium injury. PMID:25767192

  14. Excision repair in xeroderma pigmentosum group C cells is regulated differently in transformed cells and primary fibroblasts

    SciTech Connect

    Cleaver, J.E.

    1988-10-14

    Excision repair in xeroderma pigmentosum group C cells occurs at about 20-30% of normal levels. In confluent fibroblasts a unique characteristic of this low repair is that it is clustered, representing very efficient repair in a small region of the genome. In SV40-transformed fibroblasts and Epstein-Barr virus-transformed lymphocytes of complementation group C, however, excision repair is randomly distributed. This may be a consequence of the high rate of proliferation of both of these cell types, because random repair is also observed in rapidly proliferating group C fibroblasts. The distribution of sites that can be mended in group C cells, therefore, varies according to the transformed and proliferative state of the cells, demonstrating that transformed cells do not always exhibit repair characteristics identical to those of primary fibroblasts.

  15. Poly-3-hydroxybutyrate strips seeded with regenerative cells are effective promoters of peripheral nerve repair.

    PubMed

    Schaakxs, Dominique; Kalbermatten, Daniel F; Pralong, Etienne; Raffoul, Wassim; Wiberg, Mikael; Kingham, Paul J

    2017-03-01

    Peripheral nerve injuries are often associated with loss of nerve tissue and require a graft to bridge the gap. Autologous nerve grafts are still the 'gold standard' in reconstructive surgery but have several disadvantages, such as sacrifice of a functional nerve, neuroma formation and loss of sensation at the donor site. Bioengineered grafts represent a promising approach to address this problem. In this study, poly-3-hydroxybutyrate (PHB) strips were used to bridge a 10 mm rat sciatic nerve gap and their effects on long-term (12 weeks) nerve regeneration were compared. PHB strips were seeded with different cell types, either primary Schwann cells (SCs) or SC-like differentiated adipose-derived stem cells (dASCs) suspended in a fibrin glue matrix. The control group was PHB and fibrin matrix without cells. Functional and morphological properties of the regenerated nerve were assessed using walking track analysis, EMGs, muscle weight ratios and muscle and nerve histology. The animals treated with PHB strips seeded with SCs or dASCs showed significantly better functional ability than the control group. This correlated with less muscle atrophy and greater axon myelination in the cell groups. These findings suggest that the PHB strip seeded with cells provides a beneficial environment for nerve regeneration. Furthermore, dASCs, which are abundant and easily accessible, constitute an attractive cell source for future applications of cell therapy for the clinical repair of traumatic nerve injuries. Copyright © 2015 John Wiley & Sons, Ltd.

  16. XB130 promotes bronchioalveolar stem cell and Club cell proliferation in airway epithelial repair and regeneration

    PubMed Central

    Toba, Hiroaki; Wang, Yingchun; Bai, Xiaohui; Zamel, Ricardo; Cho, Hae-Ra; Liu, Hongmei; Lira, Alonso; Keshavjee, Shaf; Liu, Mingyao

    2015-01-01

    Proliferation of bronchioalveolar stem cells (BASCs) is essential for epithelial repair. XB130 is a novel adaptor protein involved in the regulation of epithelial cell survival, proliferation and migration through the PI3K/Akt pathway. To determine the role of XB130 in airway epithelial injury repair and regeneration, a naphthalene-induced airway epithelial injury model was used with XB130 knockout (KO) mice and their wild type (WT) littermates. In XB130 KO mice, at days 7 and 14, small airway epithelium repair was significantly delayed with fewer number of Club cells (previously called Clara cells). CCSP (Club cell secreted protein) mRNA expression was also significantly lower in KO mice at day 7. At day 5, there were significantly fewer proliferative epithelial cells in the KO group, and the number of BASCs significantly increased in WT mice but not in KO mice. At day 7, phosphorylation of Akt, GSK-3β, and the p85α subunit of PI3K was observed in airway epithelial cells in WT mice, but to a much lesser extent in KO mice. Microarray data also suggest that PI3K/Akt-related signals were regulated differently in KO and WT mice. An inhibitory mechanism for cell proliferation and cell cycle progression was suggested in KO mice. XB130 is involved in bronchioalveolar stem cell and Club cell proliferation, likely through the PI3K/Akt/GSK-3β pathway. PMID:26360608

  17. Stem cell therapy for the treatment of myocardial infarction.

    PubMed

    Dauwe, D F; Janssens, S P

    2011-10-01

    Despite timely reperfusion and subsequent optimal postinfarct pharmacotherapy and device-based treatment, the outcome in patients with severe myocardial infarction remains unfavourable. Myocardial salvage is incomplete, resulting in adverse left ventricular remodeling with concomitant morbidity and mortality. The combined risk of recurrent myocardial infarction, death or readmission for heart failure amounts to 25 % within the first year, highlighting the need for additional treatment strategies. Recent and rapidly evolving insights in cardiac biology, recognizing endogenous repair capabilities of the adult human heart, paved the path towards progenitor or stem cell based cardiac protection and repair strategies following ischemic injury. We critically report on the major randomized controlled clinical trials published so far concerning intracoronary transfer of autologous bone marrow cells in the setting of acute myocardial infarction. Moreover, underlying mechanisms, practical aspects, remaining questions and future challenges are highlighted. Taken together, these trials confirm the safety and feasibility of intracoronary progenitor cell transfer in the setting of myocardial infarction. Efficacy data suggests its potential to improve left ventricular function recovery beyond current state of the art therapy, but results are mixed, modest at best and do not support true cardiomyogenesis. Hence, due to its complexity, costs and remaining uncertainties, it is still too early to implement progenitor cell therapy in its current form in standard treatment strategies for ischemic heart disease. Future studies on strategies for cardiomyocyte regeneration in combination with myocardial protection are needed.

  18. Nucleosome rearrangement in human cells following short patch repair of DNA damaged by bleomycin

    SciTech Connect

    Sidik, K.; Smerdon, M.J. )

    1990-08-14

    We have examined the structure of newly repaired regions of chromatin in intact and permeabilized human cells following exposure to bleomycin (BLM). The average repair patch size (in permeabilized cells) was six to nine bases, following doses of 1-25 micrograms/mL BLM, and greater than 80% of the total repair synthesis was resistant to aphidicolin. In both intact and permeabilized cells, nascent repair patches were initially very sensitive to staphylococcal nuclease, analogous to repair induced by long patch agents, and are nearly absent from isolated nucleosome core DNA. Unlike long patch repair, however, the loss of nuclease sensitivity during subsequent chase periods was very slow in intact cells, or in permeabilized cells treated with a low dose of BLM (1 microgram/mL), and was abolished by treatment with hydroxyurea (HU) or aphidicolin (APC). The rate of repair patch ligation did not correlate with this slow rate of chromatin rearrangement since greater than 95% of the patches were ligated within 6 h after incorporation (even in the presence of HU or APC). In permeabilized cells, repair patches induced by either 5 or 25 micrograms/mL BLM, where significant levels of strand breaks occur in compact regions of chromatin, lost the enhanced nuclease sensitivity at a rate similar to that observed following long patch repair. This rapid rate of rearrangement was not affected by APC. These results indicate that short patch repair in linker regions of nucleosomes, and/or open regions of chromatin, involves much less nucleosome rearrangement than long patch repair or short patch repair in condensed chromatin domains.

  19. The Effect of Continuous Sedation Therapy on Immunomodulation, Plasma Levels of Antioxidants, and Indicators of Tissue Repair in Post-Burn Sepsis Patients.

    PubMed

    Chen, Li; Meng, Ke; Su, Wei; Fu, Yanjie

    2015-11-01

    Our objective was to investigate the effect of continuous therapeutic sedation on the immune response, plasma levels of antioxidants, and tissue repair indicators in burn-induced sepsis patients. A total of 104 burn-induced sepsis patients hospitalized during March, 2008 to March, 2013 were selected for the study and randomly divided into the experimental and control groups, each with 53 cases. All of these patients received conventional treatment and the patients in the experimental group were given an additional therapy of continuous sedation. The number of T lymphocytes, plasma levels of tissue repair indicators, and antioxidants were measured before and after the treatment. Continuous midazolam treatment induced a significant increase in plasma levels of gelsolin, heat shock protein 70, nitric oxide, superoxide dismutase, and tumor necrosis factor-alpha (p < 0.05). Likewise, the relative counts of CD3(+), CD4(+), CD8(+) T lymphocytes, T cells exhibiting HLA-DR and CD4(+)/CD8(+) ratio were significantly increased in the patients treated with midazolam. No adverse reaction including respiratory depression, midazolam resistance, or withdrawal syndrome was observed. Continuous sedation therapy was found to enhance immune response, increase the plasma levels of antioxidants, and tissue protective/repair mediators in burn-induced sepsis patients. This therapy caused no adverse reaction or over-inhibition of the oxidative stress suggesting its effectiveness in improving the prognosis without the risk of safety.

  20. Bone marrow-derived stem cell therapy for metastatic brain cancers.

    PubMed

    Kaneko, Yuji; Tajiri, Naoki; Staples, Meaghan; Reyes, Stephanny; Lozano, Diego; Sanberg, Paul R; Freeman, Thomas B; van Loveren, Harry; Kim, Seung U; Borlongan, Cesar V

    2015-01-01

    We propose that stem cell therapy may be a potent treatment for metastatic melanoma in the brain. Here we discuss the key role of a leaky blood-brain barrier (BBB) that accompanies the development of brain metastases. We review the need to characterize the immunological and inflammatory responses associated with tumor-derived BBB damage in order to reveal the contribution of this brain pathological alteration to the formation and growth of brain metastatic cancers. Next, we discuss the potential repair of the BBB and attenuation of brain metastasis through transplantation of bone marrow-derived mesenchymal stem cells with the endothelial progenitor cell phenotype. In particular, we review the need for evaluation of the efficacy of stem cell therapy in repairing a disrupted BBB in an effort to reduce neuroinflammation, eventually attenuating brain metastatic cancers. The demonstration of BBB repair through augmented angiogenesis and vasculogenesis will be critical to establishing the potential of stem cell therapy for the treatment/prevention of metastatic brain tumors. The overarching hypothesis we advanced here is that BBB breakdown is closely associated with brain metastatic cancers of melanoma, exacerbating the inflammatory response of the brain during metastasis, and ultimately worsening the outcome of metastatic brain cancers. Abrogating this leaky BBB-mediated inflammation via stem cell therapy represents a paradigm-shifting approach to treating brain cancer. This review article discusses the pros and cons of cell therapy for melanoma brain metastases.

  1. Targeting Prostate Cancer Stem Cells with Alpha-Particle Therapy.

    PubMed

    Ceder, Jens; Elgqvist, Jörgen

    2016-01-01

    Modern molecular and radiopharmaceutical development has brought the promise of tumor-selective delivery of antibody-drug conjugates to tumor cells for the diagnosis and treatment of primary and disseminated tumor disease. The classical mode of discourse regarding targeted therapy has been that the antigen targeted must be highly and homogenously expressed in the tumor cell population, and at the same time exhibit low expression in healthy tissue. However, there is increasing evidence that the reason cancer patients are not cured by current protocols is that there exist subpopulations of cancer cells that are resistant to conventional therapy including radioresistance and that these cells express other target antigens than the bulk of the tumor cells. These types of cells are often referred to as cancer stem cells (CSCs). The CSCs are tumorigenic and have the ability to give rise to all types of cells found in a cancerous disease through the processes of self-renewal and differentiation. If the CSCs are not eradicated, the cancer is likely to recur after therapy. Due to some of the characteristics of alpha particles, such as short path length and high density of energy depositions per distance traveled in tissue, they are especially well suited for use in targeted therapies against microscopic cancerous disease. The characteristics of alpha particles further make it possible to minimize the irradiation of non-targeted surrounding healthy tissue, but most importantly, make it possible to deliver high-absorbed doses locally and therefore eradicating small tumor cell clusters on the submillimeter level, or even single tumor cells. When alpha particles pass through a cell, they cause severe damage to the cell membrane, cytoplasm, and nucleus, including double-strand breaks of DNA that are very difficult to repair for the cell. This means that very few hits to a cell by alpha particles are needed in order to cause cell death, enabling killing of cells, such as CSCs

  2. Targeting Prostate Cancer Stem Cells with Alpha-Particle Therapy

    PubMed Central

    Ceder, Jens; Elgqvist, Jörgen

    2017-01-01

    Modern molecular and radiopharmaceutical development has brought the promise of tumor-selective delivery of antibody–drug conjugates to tumor cells for the diagnosis and treatment of primary and disseminated tumor disease. The classical mode of discourse regarding targeted therapy has been that the antigen targeted must be highly and homogenously expressed in the tumor cell population, and at the same time exhibit low expression in healthy tissue. However, there is increasing evidence that the reason cancer patients are not cured by current protocols is that there exist subpopulations of cancer cells that are resistant to conventional therapy including radioresistance and that these cells express other target antigens than the bulk of the tumor cells. These types of cells are often referred to as cancer stem cells (CSCs). The CSCs are tumorigenic and have the ability to give rise to all types of cells found in a cancerous disease through the processes of self-renewal and differentiation. If the CSCs are not eradicated, the cancer is likely to recur after therapy. Due to some of the characteristics of alpha particles, such as short path length and high density of energy depositions per distance traveled in tissue, they are especially well suited for use in targeted therapies against microscopic cancerous disease. The characteristics of alpha particles further make it possible to minimize the irradiation of non-targeted surrounding healthy tissue, but most importantly, make it possible to deliver high-absorbed doses locally and therefore eradicating small tumor cell clusters on the submillimeter level, or even single tumor cells. When alpha particles pass through a cell, they cause severe damage to the cell membrane, cytoplasm, and nucleus, including double-strand breaks of DNA that are very difficult to repair for the cell. This means that very few hits to a cell by alpha particles are needed in order to cause cell death, enabling killing of cells, such as CSCs

  3. Repair of gamma-ray-induced DNA base damage in xeroderma pigmentosum cells

    SciTech Connect

    Fornace, A.J. Jr.; Dobson, P.P.; Kinsella, T.J.

    1986-04-01

    The repair of DNA damage produced by /sup 137/Cs gamma irradiation was measured with a preparation from Micrococcus luteus containing DNA damage-specific endonucleases in combination with alkaline elution. The frequency of these endonuclease sensitive sites (ESS) was determined after 54 or 110 Gy of oxic irradiation in normal and xeroderma pigmentosum (XP) fibroblasts from complementation groups A, C, D, and G. Repair was rapid in all cell strains with greater than 50% repair after 1.5 h of repair incubation. At later repair times, 12-17 h, more ESS remained in XP than in normal cells. The frequency of excess ESS in XP cells was approximately 0.04 per 10(9) Da of DNA per Gy which was equivalent to 10% of the initial ESS produced. The removal of ESS was comparable in XP cells with normal radiosensitivity and XP3BR cells which have been reported to be moderately radiosensitive.

  4. Genetic repair of mutations in plant cell-free extracts directed by specific chimeric oligonucleotides.

    PubMed

    Rice, M C; May, G D; Kipp, P B; Parekh, H; Kmiec, E B

    2000-06-01

    Chimeric oligonucleotides are synthetic molecules comprised of RNA and DNA bases assembled in a double hairpin conformation. These molecules have been shown to direct gene conversion events in mammalian cells and animals through a process involving at least one protein from the DNA mismatch repair pathway. The mechanism of action for gene repair in mammalian cells has been partially elucidated through the use of a cell-free extract system. Recent experiments have expanded the utility of chimeric oligonucleotides to plants and have demonstrated genotypic and phenotypic conversion, as well as Mendelian transmission. Although these experiments showed correction of point and frameshift mutations, the biochemical and mechanistic aspects of the process were not addressed. In this paper, we describe the establishment of cell-free extract systems from maize (Zea mays), banana (Musa acuminata cv Rasthali), and tobacco (Nicotiana tabacum). Using a genetic readout system in bacteria and chimeric oligonucleotides designed to direct the conversion of mutations in antibiotic-resistant genes, we demonstrate gene repair of point and frameshift mutations. Whereas extracts from banana and maize catalyzed repair of mutations in a precise fashion, cell-free extracts prepared from tobacco exhibited either partial repair or non-targeted nucleotide conversion. In addition, an all-DNA hairpin molecule also mediated repair albeit in an imprecise fashion in all cell-free extracts tested. This system enables the mechanistic study of gene repair in plants and may facilitate the identification of DNA repair proteins operating in plant cells.

  5. The developing role of Neuregulin1 in cardiac regenerative stem cell therapy.

    PubMed

    P Blomberg, Christopher; Lee, Juyong; P Morgan, James

    2014-01-01

    Myocardial infarction, heart failure, and chronic ischemic heart disease account for the majority of the cardiovascular burden. The current treatment strategies focus on limiting the progression of disease and preserving cardiac myocardium. The goal of stem cell therapy, on the other hand, is to reverse or replace damaged cardiac tissue. Over the past two decades many studies have been conducted to understand stem cell performance, survival, and the potential for cardiac repair. Neuregulin1, an epidermal growth factor family member, promotes embryonic stem cell differentiation into the cardiac lineage and improves survival in bone marrow-derived mesenchymal stem cell and embryonic endothelial progenitor cells. Current clinical trials are actively pursuing Neuregulin1's therapeutic potential in the areas of heart failure and cardiac ischemia. It is the intent of this paper to review the current knowledge of Neuregulin1 in stem cell biology and discuss the potential of using Neuregulin1 to improve stem cell therapy for cardiac repair.

  6. Photodynamic therapy for basal cell carcinoma.

    PubMed

    Fargnoli, Maria Concetta; Peris, Ketty

    2015-11-01

    Topical photodynamic therapy is an effective and safe noninvasive treatment for low-risk basal cell carcinoma, with the advantage of an excellent cosmetic outcome. Efficacy of photodynamic therapy in basal cell carcinoma is supported by substantial research and clinical trials. In this article, we review the procedure, indications and clinical evidences for the use of photodynamic therapy in the treatment of basal cell carcinoma.

  7. The role of DNA damage repair in aging of adult stem cells.

    PubMed

    Kenyon, Jonathan; Gerson, Stanton L

    2007-01-01

    DNA repair maintains genomic stability and the loss of DNA repair capacity results in genetic instability that may lead to a decline of cellular function. Adult stem cells are extremely important in the long-term maintenance of tissues throughout life. They regenerate and renew tissues in response to damage and replace senescent terminally differentiated cells that no longer function. Oxidative stress, toxic byproducts, reduced mitochondrial function and external exposures all damage DNA through base modification or mis-incorporation and result in DNA damage. As in most cells, this damage may limit the survival of the stem cell population affecting tissue regeneration and even longevity. This review examines the hypothesis that an age-related loss of DNA damage repair pathways poses a significant threat to stem cell survival and longevity. Normal stem cells appear to have strict control of gene expression and DNA replication whereas stem cells with loss of DNA repair may have altered patterns of proliferation, quiescence and differentiation. Furthermore, stem cells with loss of DNA repair may be susceptible to malignant transformation either directly or through the emergence of cancer-prone stem cells. Human diseases and animal models of loss of DNA repair provide longitudinal analysis of DNA repair processes in stem cell populations and may provide links to the physiology of aging.

  8. Characterization of rat very small embryonic-like stem cells and cardiac repair after cell transplantation for myocardial infarction.

    PubMed

    Wu, Jin-Hong; Wang, Hai-Jie; Tan, Yu-Zhen; Li, Zhi-Hua

    2012-05-20

    Stem cell therapy is a promising therapeutic strategy for treating myocardial infarction (MI). However, it is necessary to identify ideal adult stem cells for transplantation and explore mechanisms of the transplanted cells in improving cardiac functions after MI. In this study, a population of embryonic-like stem cells (ELSCs) was isolated from rat bone marrow. The cells express pluripotent stem cell transcriptional factors and present high proliferative activity on mouse embryonic fibroblast feeder. ELSCs retain clonal expansion and may form embryoid-like bodies in soft agarose containing leukemia inhibitory factor and basic fibroblast growth factor. The cells of the embryoid-like bodies can differentiate into the cells from 3 germ layers. Under induction, the cells can differentiate into cardiomyocytes and endothelial cells. In MI models of female rats, the transplantation of preinduced ELSCs of male rats reduce scar area and improve cardiac function significantly. Comparing with marrow-derived mesenchymal stem cells and ELSCs without induction, effects of the preinduced ELSCs on myocardial repair and improvement of cardiac function are greater. Survival of the transplanted cells in the peri-infarcted and infarcted regions was examined by fluorescence in situ hybridization. Y chromosome-positive cells may differentiate toward cardiomyocytes and express cTnT and Cx43. Cx43 expression was observed at conjunction of Y chromosome-positive cells and recipient cardiomyocytes. Some Y chromosome-positive cells express CD31 and incorporate into the microvessels in the infarcted tissue. These results suggest that a population of ELSCs resides in rat bone marrow and display similar biological characteristics of ESCs. ELSCs can differentiate into cardiomyocytes and endothelial cells and contribute to cardiomyogenesis and angiogenesis in vivo. Cardiac function after MI may be significantly improved with transplantation of the preinduced ELSCs. Therefore, ELSCs are novel seed

  9. Topoisomerase degradation, DSB repair, p53 and IAPs in cancer cell resistance to camptothecin-like topoisomerase I inhibitors.

    PubMed

    Tomicic, Maja T; Kaina, Bernd

    2013-01-01

    Topoisomerase I (TOP1) inhibitors applied in cancer therapy such as topotecan and irinotecan are derivatives of the natural alkaloid camptothecin (CPT). The mechanism of CPT poisoning of TOP1 rests on inhibition of the re-ligation function of the enzyme resulting in the stabilization of the TOP1-cleavable complex. In the presence of CPTs this enzyme-DNA complex impairs transcription and DNA replication, resulting in fork stalling and the formation of DNA double-strand breaks (DSB) in proliferating cells. As with most chemotherapeutics, intrinsic and acquired drug resistance represents a hurdle that limits the success of CPT therapy. Preclinical data indicate that resistance to CPT-based drugs might be caused by factors such as (a) poor drug accumulation in the tumor, (b) high rate of drug efflux, (c) mutations in TOP1 leading to failure in CPT docking, or (d) altered signaling triggered by the drug-TOP1-DNA complex, (e) expression of DNA repair proteins, and (f) failure to activate cell death pathways. This review will focus on the issues (d-f). We discuss degradation of TOP1 as part of the repair pathway in the processing of TOP1 associated DNA damage, give a summary of proteins involved in repair of CPT-induced replication mediated DSB, and highlight the role of p53 and inhibitors of apoptosis proteins (IAPs), particularly XIAP and survivin, in cancer cell resistance to CPT-like chemotherapeutics.

  10. A biophysical model of cell evolution after cytotoxic treatments: Damage, repair and cell response.

    PubMed

    Tomezak, M; Abbadie, C; Lartigau, E; Cleri, F

    2016-01-21

    We present a theoretical agent-based model of cell evolution under the action of cytotoxic treatments, such as radiotherapy or chemotherapy. The major features of cell cycle and proliferation, cell damage and repair, and chemical diffusion are included. Cell evolution is based on a discrete Markov chain, with cells stepping along a sequence of discrete internal states from 'normal' to 'inactive'. Probabilistic laws are introduced for each type of event a cell can undergo during its life: duplication, arrest, senescence, damage, reparation, or death. We adjust the model parameters on a series of cell irradiation experiments, carried out in a clinical LINAC, in which the damage and repair kinetics of single- and double-strand breaks are followed. Two showcase applications of the model are then presented. In the first one, we reconstruct the cell survival curves from a number of published low- and high-dose irradiation experiments. We reobtain a very good description of the data without assuming the well-known linear-quadratic model, but instead including a variable DSB repair probability. The repair capability of the model spontaneously saturates to an exponential decay at increasingly high doses. As a second test, we attempt to simulate the two extreme possibilities of the so-called 'bystander' effect in radiotherapy: the 'local' effect versus a 'global' effect, respectively activated by the short-range or long-range diffusion of some factor, presumably secreted by the irradiated cells. Even with an oversimplified simulation, we could demonstrate a sizeable difference in the proliferation rate of non-irradiated cells, the proliferation acceleration being much larger for the global than the local effect, for relatively small fractions of irradiated cells in the colony.

  11. Nucleotide excision repair in rat male germ cells: low level of repair in intact cells contrasts with high dual incision activity in vitro.

    PubMed

    Jansen, J; Olsen, A K; Wiger, R; Naegeli, H; de Boer, P; van Der Hoeven, F; Holme, J A; Brunborg, G; Mullenders, L

    2001-04-15

    The acquisition of genotoxin-induced mutations in the mammalian germline is detrimental to the stable transfer of genomic information. In somatic cells, nucleotide excision repair (NER) is a major pathway to counteract the mutagenic effects of DNA damage. Two NER subpathways have been identified, global genome repair (GGR) and transcription-coupled repair (TCR). In contrast to somatic cells, little is known regarding the expression of these pathways in germ cells. To address this basic question, we have studied NER in rat spermatogenic cells in crude cell suspension, in enriched cell stages and within seminiferous tubules after exposure to UV or N-acetoxy-2-acetylaminofluorene. Surprisingly, repair in spermatogenic cells was inefficient in the genome overall and in transcriptionally active genes indicating non-functional GGR and TCR. In contrast, extracts from early/mid pachytene cells displayed dual incision activity in vitro as high as extracts from somatic cells, demonstrating that the proteins involved in incision are present and functional in premeiotic cells. However, incision activities of extracts from diplotene cells and round spermatids were low, indicating a stage-dependent expression of incision activity. We hypothesize that sequestering of NER proteins by mispaired regions in DNA involved in synapsis and recombination may underlie the lack of NER activity in premeiotic cells.

  12. Polymeric scaffolds as stem cell carriers in bone repair.

    PubMed

    Rossi, Filippo; Santoro, Marco; Perale, Giuseppe

    2015-10-01

    Although bone has a high potential to regenerate itself after damage and injury, the efficacious repair of large bone defects resulting from resection, trauma or non-union fractures still requires the implantation of bone grafts. Materials science, in conjunction with biotechnology, can satisfy these needs by developing artificial bones, synthetic substitutes and organ implants. In particular, recent advances in polymer science have provided several innovations, underlying the increasing importance of macromolecules in this field. To address the increasing need for improved bone substitutes, tissue engineering seeks to create synthetic, three-dimensional scaffolds made from polymeric materials, incorporating stem cells and growth factors, to induce new bone tissue formation. Polymeric materials have shown a great affinity for cell transplantation and differentiation and, moreover, their structure can be tuned in order to maintain an adequate mechanical resistance and contemporarily be fully bioresorbable. This review emphasizes recent progress in polymer science that allows relaible polymeric scaffolds to be synthesized for stem cell growth in bone regeneration.

  13. Mesenchymal stem cell therapy for injured growth plate.

    PubMed

    Shukrimi, Awang B; Afizah, Mohd H; Schmitt, Jacqueline F; Hui, James H P

    2013-01-01

    The growth plate has a limited self-healing capacity. Fractures sustained to the growth plate of young children could cause growth disturbances like angular deformity or growth arrest. Established therapies for injured physis only address related complications. Mesenchymal stem cells (MSCs) are multipotent cells which are capable of differentiating into various cells of the musculoskeletal system. Various MSC types have been tested for physeal regeneration, through in vivo lapine, porcine and ovine models, for the duration of 4-16 weeks. The created defect sizes ranged from 7-50% of the growth plate area, to simulate clinically-encountered cases. In vitro models have also been investigated, as a means to screen potential treatments. The effects of MSCs gathered from these models have revealed its function in the prevention of bone bridge formation, with the subsequent development of organized physeal repair tissue. Possible influential factors like the number of implanted MSCs, preconditioned state, growth factors, chondrocyte-MSC interaction and scaffolds are discussed. Possible further studies to optimize physeal repair based on MSC therapy in articular cartilage are also included.

  14. Radiation damage and repair in cells and cell components. Radiation-induced repair. Progress report, 1981-1982

    SciTech Connect

    Not Available

    1982-01-01

    Progress in research on the description and interpretation of radiation-induced repair in cells is reported. It has been found that for the p-recA data induction seems to follow a model of fractional site occupancy rather than being all-or-none. Other areas investigated include: (1) the induction of the RecA-gene product; (2) the effect of uv-phage lambda infection on Rec-A protein synthesis; (3) induced uv radioresistance; (4) cold-shock effects; (5) lambda-prophage induction by x-rays and uv; (6) photoreactivation of uv-induced dimers; and (7) a comparative study of S.O.S. phenomena in various strains of E. coli. (ACR)

  15. A novel strategy to enhance mesenchymal stem cell migration capacity and promote tissue repair in an injury specific fashion.

    PubMed

    Xinaris, C; Morigi, M; Benedetti, V; Imberti, B; Fabricio, A S; Squarcina, E; Benigni, A; Gagliardini, E; Remuzzi, G

    2013-01-01

    Mesenchymal stem cells (MSCs) of bone marrow origin appear to be an attractive candidate for cell-based therapies. However, the major barrier to the effective implementation of MSC-based therapies is the lack of specific homing of exogenously infused cells and overall the inability to drive them to the diseased or damaged tissue. In order to circumvent these limitations, we developed a preconditioning strategy to optimize MSC migration efficiency and potentiate their beneficial effect at the site of injury. Initially, we screened different molecules by using an in vitro injury-migration setting, and subsequently, we evaluated the effectiveness of the different strategies in mice with acute kidney injury (AKI). Our results showed that preconditioning of MSCs with IGF-1 before infusion improved cell migration capacity and restored normal renal function after AKI. The present study demonstrates that promoting migration of MSCs could increase their therapeutic potential and indicates a new therapeutic paradigm for organ repair.

  16. Nucleotide Excision Repair and Vitamin D--Relevance for Skin Cancer Therapy.

    PubMed

    Pawlowska, Elzbieta; Wysokinski, Daniel; Blasiak, Janusz

    2016-04-06

    Ultraviolet (UV) radiation is involved in almost all skin cancer cases, but on the other hand, it stimulates the production of pre-vitamin D3, whose active metabolite, 1,25-dihydroxyvitamin D3 (1,25VD3), plays important physiological functions on binding with its receptor (vitamin D receptor, VDR). UV-induced DNA damages in the form of cyclobutane pyrimidine dimers or (6-4)-pyrimidine-pyrimidone photoproducts are frequently found in skin cancer and its precursors. Therefore, removing these lesions is essential for the prevention of skin cancer. As UV-induced DNA damages are repaired by nucleotide excision repair (NER), the interaction of 1,25VD3 with NER components can be important for skin cancer transformation. Several studies show that 1,25VD3 protects DNA against damage induced by UV, but the exact mechanism of this protection is not completely clear. 1,25VD3 was also shown to affect cell cycle regulation and apoptosis in several signaling pathways, so it can be considered as a potential modulator of the cellular DNA damage response, which is crucial for mutagenesis and cancer transformation. 1,25VD3 was shown to affect DNA repair and potentially NER through decreasing nitrosylation of DNA repair enzymes by NO overproduction by UV, but other mechanisms of the interaction between 1,25VD3 and NER machinery also are suggested. Therefore, the array of NER gene functioning could be analyzed and an appropriate amount of 1.25VD3 could be recommended to decrease UV-induced DNA damage important for skin cancer transformation.

  17. Nucleotide Excision Repair and Vitamin D—Relevance for Skin Cancer Therapy

    PubMed Central

    Pawlowska, Elzbieta; Wysokinski, Daniel; Blasiak, Janusz

    2016-01-01

    Ultraviolet (UV) radiation is involved in almost all skin cancer cases, but on the other hand, it stimulates the production of pre-vitamin D3, whose active metabolite, 1,25-dihydroxyvitamin D3 (1,25VD3), plays important physiological functions on binding with its receptor (vitamin D receptor, VDR). UV-induced DNA damages in the form of cyclobutane pyrimidine dimers or (6-4)-pyrimidine-pyrimidone photoproducts are frequently found in skin cancer and its precursors. Therefore, removing these lesions is essential for the prevention of skin cancer. As UV-induced DNA damages are repaired by nucleotide excision repair (NER), the interaction of 1,25VD3 with NER components can be important for skin cancer transformation. Several studies show that 1,25VD3 protects DNA against damage induced by UV, but the exact mechanism of this protection is not completely clear. 1,25VD3 was also shown to affect cell cycle regulation and apoptosis in several signaling pathways, so it can be considered as a potential modulator of the cellular DNA damage response, which is crucial for mutagenesis and cancer transformation. 1,25VD3 was shown to affect DNA repair and potentially NER through decreasing nitrosylation of DNA repair enzymes by NO overproduction by UV, but other mechanisms of the interaction between 1,25VD3 and NER machinery also are suggested. Therefore, the array of NER gene functioning could be analyzed and an appropriate amount of 1.25VD3 could be recommended to decrease UV-induced DNA damage important for skin cancer transformation. PMID:27058533

  18. Cell Therapy and Tissue Engineering from and toward the Uterus.

    PubMed

    Cervelló, Irene; Santamaría, Xavier; Miyazaki, Kaoru; Maruyama, Tetsuo; Simón, Carlos

    2015-09-01

    Regenerative medicine offers the potential for replacement or repair of different types of cells within damaged tissues or the tissues themselves, typically through cell therapy or tissue engineering. Stem cells are critical to these approaches; indeed, the involvement of bone marrow in the differentiation of stem cells to nonhematopoietic cells is well demonstrated. Further, the contribution of bone marrow-derived stem cells in promoting neoangiogenesis has been demonstrated not only in animal models, but also in human clinical trials with an excellent safety profile. Recent evidence indicates that the endometrium is a tissue with the potential for regeneration through such approaches. The presence of donor cells in the endometrium of women receiving bone marrow transplantation suggests a hematopoietic source with the ability to renew this tissue. Here we describe the role of cell therapy with bone marrow-derived stem cells in treating endometrial dysfunction in Asherman syndrome and/or endometrial atrophy in human and murine models. Additionally, the emerging field of tissue engineering has recently been applied in the reproductive tissues-beyond the endometrium-with elegant studies involving humans and animal models.

  19. DNA excision repair in cell extracts from human cell lines exhibiting hypersensitivity to DNA-damaging agents

    SciTech Connect

    Hansson, J.; Keyse, S.M.; Lindahl, T.; Wood, R.D. )

    1991-07-01

    Whole cell extracts from human lymphoid cell lines can perform in vitro DNA repair synthesis in plasmids damaged by agents including UV or cis-diamminedichloroplatinum(II) (cis-DDP). Extracts from xeroderma pigmentosum (XP) cells are defective in repair synthesis. We have now studied in vitro DNA repair synthesis using extracts from lymphoblastoid cell lines representing four human hereditary syndromes with increased sensitivity to DNA-damaging agents. Extracts of cell lines from individuals with the sunlight-sensitive disorders dysplastic nevus syndrome or Cockayne's syndrome (complementation groups A and B) showed normal DNA repair synthesis in plasmids with UV photoproducts. This is consistent with in vivo measurements of the overall DNA repair capacity in such cell lines. A number of extracts were prepared from two cell lines representing the variant form of XP (XP-V). Half of the extracts prepared showed normal levels of in vitro DNA repair synthesis in plasmids containing UV lesions, but the remainder of the extracts from the same cell lines showed deficient repair synthesis, suggesting the possibility of an unusually labile excision repair protein in XP-V. Fanconi's anemia (FA) cells show cellular hypersensitivity to cross-linking agents including cis-DDP. Extracts from cell lines belonging to two different complementation groups of FA showed normal DNA repair synthesis in plasmids containing cis-DDP or UV adducts. Thus, there does not appear to be an overall excision repair defect in FA, but the data do not exclude a defect in the repair of interstrand DNA cross-links.

  20. Cell Therapies in Cardiomyopathy: Current Status of Clinical Trials

    PubMed Central

    Wang, Richard

    2017-01-01

    Because the human heart has limited potential for regeneration, the loss of cardiomyocytes during cardiac myopathy and ischaemic injury can result in heart failure and death. Stem cell therapy has emerged as a promising strategy for the treatment of dead myocardium, directly or indirectly, and seems to offer functional benefits to patients. The ideal candidate donor cell for myocardial reconstitution is a stem-like cell that can be easily obtained, has a robust proliferation capacity and a low risk of tumour formation and immune rejection, differentiates into functionally normal cardiomyocytes, and is suitable for minimally invasive clinical transplantation. The ultimate goal of cardiac repair is to regenerate functionally viable myocardium after myocardial infarction (MI) to prevent or heal heart failure. This review provides a comprehensive overview of treatment with stem-like cells in preclinical and clinical studies to assess the feasibility and efficacy of this novel therapeutic strategy in ischaemic cardiomyopathy. PMID:28194324

  1. Stem cell therapy for Parkinson's disease.

    PubMed

    Takahashi, Jun

    2007-06-01

    The aim of stem cell therapy for Parkinson's disease is to reconstruct nigro-striatal neuronal pathways using endogenous neural stem/precursor cells or grafted dopaminergic neurons. As an alternative, transplantation of stem cell-derived dopaminergic neurons into the striatum has been attempted, with the aim of stimulating local synapse formation and/or release of dopamine and cytokines from grafted cells. Candidate stem cells include neural stem/precursor cells, embryonic stem cells and other stem/precursor cells. Among these, embryonic stem cells are pluripotent cells that proliferate extensively, making them a good potential donor source for transplantation. However, tumor formation and ethical issues present major problems for embryonic stem cell therapy. This review describes the current status of stem cell therapy for Parkinson's disease, as well as future research approaches from a clinical perspective.

  2. Enzyme plus light therapy to repair DNA damage in ultraviolet-B-irradiated human skin

    PubMed Central

    Stege, Helger; Roza, Len; Vink, Arie A.; Grewe, Markus; Ruzicka, Thomas; Grether-Beck, Susanne; Krutmann, Jean

    2000-01-01

    Ultraviolet-B (UVB) (290–320 nm) radiation-induced cyclobutane pyrimidine dimers within the DNA of epidermal cells are detrimental to human health by causing mutations and immunosuppressive effects that presumably contribute to photocarcinogenesis. Conventional photoprotection by sunscreens is exclusively prophylactic in nature and of no value once DNA damage has occurred. In this paper, we have therefore assessed whether it is possible to repair UVB radiation-induced DNA damage through topical application of the DNA-repair enzyme photolyase, derived from Anacystis nidulans, that specifically converts cyclobutane dimers into their original DNA structure after exposure to photoreactivating light. When a dose of UVB radiation sufficient to induce erythema was administered to the skin of healthy subjects, significant numbers of dimers were formed within epidermal cells. Topical application of photolyase-containing liposomes to UVB-irradiated skin and subsequent exposure to photoreactivating light decreased the number of UVB radiation-induced dimers by 40–45%. No reduction was observed if the liposomes were not filled with photolyase or if photoreactivating exposure preceded the application of filled liposomes. The UVB dose administered resulted in suppression of intercellular adhesion molecule-1 (ICAM-1), a molecule required for immunity and inflammatory events in the epidermis. In addition, in subjects hypersensitive to nickel sulfate, elicitation of the hypersensitivity reaction in irradiated skin areas was prevented. Photolyase-induced dimer repair completely prevented these UVB radiation-induced immunosuppressive effects as well as erythema and sunburn-cell formation. These studies demonstrate that topical application of photolyase is effective in dimer reversal and thereby leads to immunoprotection. PMID:10660687

  3. Melatonin sensitizes human breast cancer cells to ionizing radiation by downregulating proteins involved in double-strand DNA break repair.

    PubMed

    Alonso-González, Carolina; González, Alicia; Martínez-Campa, Carlos; Gómez-Arozamena, José; Cos, Samuel

    2015-03-01

    Radiation and adjuvant endocrine therapy are nowadays considered a standard treatment option after surgery in breast cancer. Melatonin exerts oncostatic actions on human breast cancer cells. In the current study, we investigated the effects of a combination of radiotherapy and melatonin on human breast cancer cells. Melatonin (1 mm, 10 μm and 1 nm) significantly inhibited the proliferation of MCF-7 cells. Radiation alone inhibited the MCF-7 cell proliferation in a dose-dependent manner. Pretreatment of breast cancer cells with melatonin 1 wk before radiation led to a significantly greater decrease of MCF-7 cell proliferation compared with radiation alone. Melatonin pretreatment before radiation also decreased G2 -M phase arrest compared with irradiation alone, with a higher percentage of cells in the G0 -G1 phase and a lower percentage of cells in S phase. Radiation alone diminished RAD51 and DNA-protein kinase (PKcs) mRNA expression, two main proteins involved in double-strand DNA break repair. Treatment with melatonin for 7 days before radiation led to a significantly greater decrease in RAD51 and DNA-PKcs mRNA expression compared with radiation alone. Our findings suggest that melatonin pretreatment before radiation sensitizes breast cancer cells to the ionizing effects of radiation by decreasing cell proliferation, inducing cell cycle arrest and downregulating proteins involved in double-strand DNA break repair. These findings may have implications for designing clinical trials using melatonin and radiotherapy.

  4. Stem cells in the hair follicle bulge contribute to wound repair but not to homeostasis of the epidermis.

    PubMed

    Ito, Mayumi; Liu, Yaping; Yang, Zaixin; Nguyen, Jane; Liang, Fan; Morris, Rebecca J; Cotsarelis, George

    2005-12-01

    The discovery of long-lived epithelial stem cells in the bulge region of the hair follicle led to the hypothesis that epidermal renewal and epidermal repair after wounding both depend on these cells. To determine whether bulge cells are necessary for epidermal renewal, here we have ablated these cells by targeting them with a suicide gene encoding herpes simplex virus thymidine kinase (HSV-TK) using a Keratin 1-15 (Krt1-15) promoter. We show that ablation leads to complete loss of hair follicles but survival of the epidermis. Through fate-mapping experiments, we find that stem cells in the hair follicle bulge do not normally contribute cells to the epidermis which is organized into epidermal proliferative units, as previously predicted. After epidermal injury, however, cells from the bulge are recruited into the epidermis and migrate in a linear manner toward the center of the wound, ultimately forming a marked radial pattern. Notably, although the bulge-derived cells acquire an epidermal phenotype, most are eliminated from the epidermis over several weeks, indicating that bulge stem cells respond rapidly to epidermal wounding by generating short-lived 'transient amplifying' cells responsible for acute wound repair. Our findings have implications for both gene therapy and developing treatments for wounds because it will be necessary to consider epidermal and hair follicle stem cells as distinct populations.

  5. Effects of low-level laser therapy on skeletal muscle repair: a systematic review.

    PubMed

    Alves, Agnelo Neves; Fernandes, Kristianne Porta Santos; Deana, Alessandro Melo; Bussadori, Sandra Kalil; Mesquita-Ferrari, Raquel Agnelli

    2014-12-01

    A review of the literature was performed to demonstrate the most current applicability of low-level laser therapy (LLLT) for the treatment of skeletal muscle injuries, addressing different lasers, irradiation parameters, and treatment results in animal models. Searches were performed in the PubMed/MEDLINE, SCOPUS, and SPIE Digital Library databases for studies published from January 2006 to August 2013 on the use of LLLT for the repair of skeletal muscle in any animal model. All selected articles were critically appraised by two independent raters. Seventeen of the 36 original articles on LLLT and muscle injuries met the inclusion criteria and were critically evaluated. The main effects of LLLT were a reduction in the inflammatory process, the modulation of growth factors and myogenic regulatory factors, and increased angiogenesis. The studies analyzed demonstrate the positive effects of LLLT on the muscle repair process, which are dependent on irradiation and treatment parameters. The findings suggest that LLLT is an excellent therapeutic resource for the treatment of skeletal muscle injuries in the short-term.

  6. Inhibition of DNA replication and repair by anthralin or danthron in cultured human cells

    SciTech Connect

    Clark, J.M.; Hanawalt, P.C.

    1982-07-01

    The comparative effects of the tumor promoter anthralin and its analog, danthron, on semiconservative DNA replication and DNA repair synthesis were studied in cultured human cells. Bromodeoxyuridine was used as density label together with /sup 3/H-thymidine to distinguish replication from repair synthesis in isopycnic CsCl gradients. Anthralin at 1.1 microgram inhibited replication in T98G cells by 50%. In cells treated with 0.4 or 1.3 microM anthralin and additive effect was observed on the inhibition of replication by ultraviolet light (254 nm). In cells irradiated with 20 J/m2, 2.3 microM anthralin was required to inhibit repair synthesis by 50%. Thus there was no selective inhibitory effect of anthralin on repair synthesis. Danthron exhibited no detectable effect on either semiconservative replication or repair synthesis at concentrations below about 5.0 microM. Neither compound stimulated repair synthesis in the absence of ultraviolet irradiation. Thus, anthralin and danthron do not appear to react with DNA to form adducts that are subject to excision repair. Although both compounds appear to intercalate into supercoiled DNA in vitro to a limited extent, the degree of unwinding introduced by the respective drugs does not correlate with their relative effects on DNA synthesis in vivo. Therefore the inhibitory effect of anthralin on DNA replication and repair synthesis in T98G cells does not appear to result from the direct interaction of the drug with DNA.

  7. Cell resistance to the Cytolethal Distending Toxin involves an association of DNA repair mechanisms

    PubMed Central

    Bezine, Elisabeth; Malaisé, Yann; Loeuillet, Aurore; Chevalier, Marianne; Boutet-Robinet, Elisa; Salles, Bernard; Mirey, Gladys; Vignard, Julien

    2016-01-01

    The Cytolethal Distending Toxin (CDT), produced by many bacteria, has been associated with various diseases including cancer. CDT induces DNA double-strand breaks (DSBs), leading to cell death or mutagenesis if misrepaired. At low doses of CDT, other DNA lesions precede replication-dependent DSB formation, implying that non-DSB repair mechanisms may contribute to CDT cell resistance. To address this question, we developed a proliferation assay using human cell lines specifically depleted in each of the main DNA repair pathways. Here, we validate the involvement of the two major DSB repair mechanisms, Homologous Recombination and Non Homologous End Joining, in the management of CDT-induced lesions. We show that impairment of single-strand break repair (SSBR), but not nucleotide excision repair, sensitizes cells to CDT, and we explore the interplay of SSBR with the DSB repair mechanisms. Finally, we document the role of the replicative stress response and demonstrate the involvement of the Fanconi Anemia repair pathway in response to CDT. In conclusion, our work indicates that cellular survival to CDT-induced DNA damage involves different repair pathways, in particular SSBR. This reinforces a model where CDT-related genotoxicity primarily involves SSBs rather than DSBs, underlining the importance of cell proliferation during CDT intoxication and pathogenicity. PMID:27775089

  8. Deficient repair of chemical adducts in alpha DNA of monkey cells

    SciTech Connect

    Zolan, M.E.; Cortopassi, G.A.; Smith, C.A.; Hanawalt, P.C.

    1982-03-01

    Researchers have examined excision repair of DNA damage in the highly repeated alpha DNA sequence of cultured African green monkey cells. Irradiation of cells with 254 nm ultraviolet light resulted in the same frequency of pyrimidine dimers in alpha DNA and the bulk of the DNA. The rate and extent of pyrimidine dimer removal, as judged by measurement of repair synthesis, was also similar for alpha DNA and bulk DNA. In cells treated with furocoumarins and long-wave-length ultraviolet light, however, repair synthesis in alpha DNA was only 30% of that in bulk DNA, although it followed the same time course. Researchers found that this reduced repair was not caused by different initial amounts of furocoumarin damage or by different sizes of repair patches, as researchers found these to be similar in the two DNA species. Direct quantification demonstrated that fewer furocoumarin adducts were removed from alpha DNA than from bulk DNA. In cells treated with another chemical DNA-damaging agent, N-acetoxy-2-acetylaminofluorene, repair synthesis in alpha DNA was 60% of that in bulk DNA. These results show that the repair of different kinds of DNA damage can be affected to different extents by some property of this tandemly repeated heterochromatic DNA. To our knowledge, this is the first demonstration in primate cells of differential repair of cellular DNA sequences.

  9. Perspectives of gene therapy in stem cell tissue engineering.

    PubMed

    Goessler, Ulrich Reinhart; Riedel, Katrin; Hormann, Karl; Riedel, Frank

    2006-01-01

    Tissue engineering is an interdisciplinary field that applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain or improve tissue function. It is hoped that forming tissue de novo will overcome many problems in plastic surgery associated with such areas as wound healing and the immunogenicity of transplanted tissue that lead to dysfunctional repair. Gene therapy is the science of the transfer of genetic material into individuals for therapeutic purposes by altering cellular function or structure at the molecular level. Recently, tissue engineering has been used in conjunction with gene therapy as a hybrid approach. This combination of stem-cell-based tissue engineering with gene therapy has the potential to provide regenerative tissue cells within an environment of optimal regulatory protein expression and would have many benefits in various areas such as the transplantation of skin, cartilage or bone. The aim of this review is to outline tissue engineering and possible applications of gene therapy in the field of biomedical engineering as well as basic principles of gene therapy, vectors and gene delivery.

  10. Oligonucleotide-mediated gene repair at DNA level: the potential applications for gene therapy.

    PubMed

    Liu, Chang-Mei; Liu, De-Pei; Liang, Chih-Chuan

    2002-10-01

    Mutations in gene sequence can cause many genetic disorders, and researchers have attempted to develop treatments or cures at the DNA level for these diseases. Several strategies including triple-helix-forming oligonucleotides (TFOs), chimeric RNA/DNA oligonucleotide (RDO), and short single-stranded oligodeoxynucleotide (ODN) have been used to correct the dysfunctional genes in situ in the chromosome. Experimental data from cells and animal models suggest that all these strategies can repair the mutations in situ at DNA level. More effective structures of oligonucleotide, efficient delivery systems, and gene correction efficiency should be improved. Development of these strategies holds great potentials for treatments of genetic defects and other disorders.

  11. Epidermal Permeability Barrier Defects and Barrier Repair Therapy in Atopic Dermatitis

    PubMed Central

    Lee, Hae-Jin

    2014-01-01

    Atopic dermatitis (AD) is a multifactorial inflammatory skin disease perpetuated by gene-environmental interactions and which is characterized by genetic barrier defects and allergic inflammation. Recent studies demonstrate an important role for the epidermal permeability barrier in AD that is closely related to chronic immune activation in the skin during systemic allergic reactions. Moreover, acquired stressors (e.g., Staphylococcus aureus infection) to the skin barrier may also initiate inflammation in AD. Many studies involving patients with AD revealed that defective skin barriers combined with abnormal immune responses might contribute to the pathophysiology of AD, supporting the outside-inside hypothesis. In this review, we discuss the recent advances in human and animal models, focusing on the defects of the epidermal permeability barrier, its immunologic role and barrier repair therapy in AD. PMID:24991450

  12. Biomarkers for immune therapy in colorectal cancer: mismatch-repair deficiency and others

    PubMed Central

    Bupathi, Manojkumar

    2016-01-01

    Colorectal cancer (CRC) is a heterogeneous disease for which the treatment backbone has primarily been cytotoxic chemotherapy. With better understanding of the involved molecular mechanisms, it is now known that there are a number of epigenetic and genetic events, which are involved in CRC pathogenesis. Specific biomarkers have been identified which can be used to determine the clinical outcome of patients beyond tumor staging and predict for treatment efficacy. Molecular testing is now routinely performed to select for patients that will benefit the most from targeted agents and immunotherapy. In addition to KRAS, NRAS, and BRAF mutation (MT), analysis of DNA mismatch repair (MMR) status, tumor infiltrating lymphocytes, and checkpoint protein expression may be helpful to determine whether patients are eligible for certain therapies. The focus of this article is to discuss present and upcoming biomarkers for immunotherapy in CRC. PMID:27747085

  13. Stem cells and cell therapies in lung biology and lung diseases.

    PubMed

    Weiss, Daniel J; Bertoncello, Ivan; Borok, Zea; Kim, Carla; Panoskaltsis-Mortari, Angela; Reynolds, Susan; Rojas, Mauricio; Stripp, Barry; Warburton, David; Prockop, Darwin J

    2011-06-01

    The University of Vermont College of Medicine and the Vermont Lung Center, with support of the National Heart, Lung, and Blood Institute (NHLBI), the Alpha-1 Foundation, the American Thoracic Society, the Emory Center for Respiratory Health,the Lymphangioleiomyomatosis (LAM) Treatment Alliance,and the Pulmonary Fibrosis Foundation, convened a workshop,‘‘Stem Cells and Cell Therapies in Lung Biology and Lung Diseases,’’ held July 26-29, 2009 at the University of Vermont,to review the current understanding of the role of stem and progenitor cells in lung repair after injury and to review the current status of cell therapy approaches for lung diseases. These are rapidly expanding areas of study that provide further insight into and challenge traditional views of the mechanisms of lung repair after injury and pathogenesis of several lung diseases. The goals of the conference were to summarize the current state of the field, discuss and debate current controversies, and identify future research directions and opportunities for both basic and translational research in cell-based therapies for lung diseases.

  14. DNA repair in cells sensitive and resistant to cis-diamminedichloroplatinum(II): Host cell reactivation of damaged plasmid DNA

    SciTech Connect

    Sheibani, N.; Jennerwein, M.M.; Eastman, A. )

    1989-04-04

    cis-Diamminedichloroplatinum(II) (cis-DDP) has a broad clinical application as an effective anticancer drug. However, development of resistance to the cytotoxic effects is a limiting factor. In an attempt to understand the mechanism of resistance, the authors have employed a host cell reactivation assay of DNA repair using a cis-DDP-damaged plasmid vector. The efficiency of DNA repair was assayed by measuring the activity of an enzyme coded for by the plasmid vector. The plasmid expression vector pRSV cat contains the bacterial gene coding for chloramphenicol acetyltransferase (CAT) in a configuration which permits expression in mammalian cells. The plasmid was transfected into repair-proficient and -deficient Chinese hamster ovary cells, and CAT activity was subsequently measured in cell lysates. In the repair-deficient cells, one cis-DDP adduct per cat gene was sufficient to eliminate expression. An equivalent inhibition of CAT expression in the repair-proficient cells did not occur until about 8 times the amount of damage was introduced into the plasmid. These results implicate DNA intrastrand cross-links as the lesions responsible for the inhibition of CAT expression. This assay was used to investigate the potential role of DNA repair in mediating cis-DDP resistance in murine leukemia L1210 cells. The assay readily detects the presence or absence of repair and confirms that these resistant L1210 cells have an enhanced capacity for repair of cis-DDP-induced intrastrand cross-links.

  15. The Effect of Exercise on the Early Stages of Mesenchymal Stromal Cell-Induced Cartilage Repair in a Rat Osteochondral Defect Model

    PubMed Central

    Yamaguchi, Shoki; Aoyama, Tomoki; Ito, Akira; Nagai, Momoko; Iijima, Hirotaka; Tajino, Junichi; Zhang, Xiangkai; Kiyan, Wataru; Kuroki, Hiroshi

    2016-01-01

    The repair of articular cartilage is challenging owing to the restriction in the ability of articular cartilage to repair itself. Therefore, cell supplementation therapy is possible cartilage repair method. However, few studies have verified the efficacy and safety of cell supplementation therapy. The current study assessed the effect of exercise on early the phase of cartilage repair following cell supplementation utilizing mesenchymal stromal cell (MSC) intra-articular injection. An osteochondral defect was created on the femoral grooves bilaterally of Wistar rats. Mesenchymal stromal cells that were obtained from male Wistar rats were cultured in monolayer. After 4 weeks, MSCs were injected into the right knee joint and the rats were randomized into an exercise or no-exercise intervention group. The femurs were divided as follows: C group (no exercise without MSC injection); E group (exercise without MSC injection); M group (no exercise with MSC injection); and ME group (exercise with MSC injection). At 2, 4, and 8 weeks after the injection, the femurs were sectioned and histologically graded using the Wakitani cartilage repair scoring system. At 2 weeks after the injection, the total histological scores of the M and ME groups improved significantly compared with those of the C group. Four weeks after the injection, the scores of both the M and ME groups improved significantly. Additionally, the scores in the ME group showed a significant improvement compared to those in the M group. The improvement in the scores of the E, M, and ME groups at 8 weeks were not significantly different. The findings indicate that exercise may enhance cartilage repair after an MSC intra-articular injection. This study highlights the importance of exercise following cell transplantation therapy. PMID:26968036

  16. Macrophages: supportive cells for tissue repair and regeneration.

    PubMed

    Chazaud, Bénédicte

    2014-03-01

    Macrophages, and more broadly inflammation, have been considered for a long time as bad markers of tissue homeostasis. However, if it is indisputable that macrophages are associated with many diseases in a deleterious way, new roles have emerged, showing beneficial properties of macrophages during tissue repair and regeneration. This discrepancy is likely due to the high plasticity of macrophages, which may exhibit a wide range of phenotypes and functions depending on their environment. Therefore, regardless of their role in immunity, macrophages play a myriad of roles in the maintenance and recovery of tissue homeostasis. They take a major part in the resolution of inflammation. They also exert various effects of parenchymal cells, including stem and progenitor cell, of which they regulate the fate. In the present review, few examples from various tissues are presented to illustrate that, beyond their specific properties in a given tissue, common features have been described that sustain a role of macrophages in the recovery and maintenance of tissue homeostasis.

  17. How cancer cells hijack DNA double-strand break repair pathways to gain genomic instability.

    PubMed

    Jeggo, Penny A; Löbrich, Markus

    2015-10-01

    DNA DSBs (double-strand breaks) are a significant threat to the viability of a normal cell, since they can result in loss of genetic material if mitosis or replication is attempted in their presence. Consequently, evolutionary pressure has resulted in multiple pathways and responses to enable DSBs to be repaired efficiently and faithfully. Cancer cells, which are under pressure to gain genomic instability, have a striking ability to avoid the elegant mechanisms by which normal cells maintain genomic stability. Current models suggest that, in normal cells, DSB repair occurs in a hierarchical manner that promotes rapid and efficient rejoining first, with the utilization of additional steps or pathways of diminished accuracy if rejoining is unsuccessful or delayed. In the present review, we evaluate the fidelity of DSB repair pathways and discuss how cancer cells promote the utilization of less accurate processes. Homologous recombination serves to promote accuracy and stability during replication, providing a battlefield for cancer to gain instability. Non-homologous end-joining, a major DSB repair pathway in mammalian cells, usually operates with high fidelity and only switches to less faithful modes if timely repair fails. The transition step is finely tuned and provides another point of attack during tumour progression. In addition to DSB repair, a DSB signalling response activates processes such as cell cycle checkpoint arrest, which enhance the possibility of accurate DSB repair. We consider the ways by which cancers modify and hijack these processes to gain genomic instability.

  18. Gene and Cell Therapy for Heart Failure

    PubMed Central

    2009-01-01

    Abstract Cardiac gene and cell therapy have both entered clinical trials aimed at ameliorating ventricular dysfunction in patients with chronic congestive heart failure. The transduction of myocardial cells with viral constructs encoding a specific cardiomyocyte Ca2+ pump in the sarcoplasmic reticulum (SR), SRCa2+-ATPase has been shown to correct deficient Ca2+ handling in cardiomyocytes and improvements in contractility in preclinical studies, thus leading to the first clinical trial of gene therapy for heart failure. In cell therapy, it is not clear whether beneficial effects are cell-type specific and how improvements in contractility are brought about. Despite these uncertainties, a number of clinical trials are under way, supported by safety and efficacy data from trials of cell therapy in the setting of myocardial infarction. Safety concerns for gene therapy center on inflammatory and immune responses triggered by viral constructs, and for cell therapy with myoblast cells, the major concern is increased incidence of ventricular arrhythmia after cell transplantation. Principles and mechanisms of action of gene and cell therapy for heart failure are discussed, together with the potential influence of reactive oxygen species on the efficacy of these treatments and the status of myocardial-delivery techniques for viral constructs and cells. Antioxid. Redox Signal. 11, 2025–2042. PMID:19416058

  19. Improve T Cell Therapy in Neuroblastoma

    DTIC Science & Technology

    2014-07-01

    AD_________________ Award Number: W81XWH-10-1-0425 TITLE: Improve T Cell Therapy in Neuroblastoma ...2014 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Improve T Cell Therapy in Neuroblastoma 5b. GRANT NUMBER W81XWH-10-1-0425 5c. PROGRAM...AVAILABILITY STATEMENT Approved for Public Release; Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Neuroblastoma (NB) is

  20. Differential Expression of DNA Double-Strand Break Repair Proteins in Breast Cells

    DTIC Science & Technology

    2002-07-01

    DNA-PK in human breast tissues by immuno-histochemistry and extended these studies to two other components of the NHEJ repair pathway, XRCC4 and DNA ... ligase IV, as well as other DNA repair components including NBS 1 and MRE11. In contrast to the original report, 90% of the epithelial cells in normal

  1. Differential Expression of DNA Double-Strand Break Repair Proteins in Breast Cells

    DTIC Science & Technology

    2003-07-01

    DNA-PK in human breast tissues by immuno-histochemistry and extended these studies to two other components of the NHEJ repair pathway, XRCC4 and DNA ... ligase IV, as well as other DNA repair components including NBSl and MRE11. In contrast to the original report, 90% of the epithelial cells in normal

  2. Using Arabidopsis cell extracts to monitor repair of DNA base damage in vitro.

    PubMed

    Córdoba-Cañero, Dolores; Roldán-Arjona, Teresa; Ariza, Rafael R

    2012-01-01

    Base excision repair (BER) is a major pathway for the removal of endogenous and exogenous DNA damage. This repair mechanism is initiated by DNA glycosylases that excise the altered base, and continues through alternative routes that culminate in DNA resynthesis and ligation. In contrast to the information available for microbes and animals, our knowledge about this important DNA repair pathway in plants is very limited, partially due to a lack of biochemical approaches. Here we describe an in vitro assay to monitor BER in cell-free extracts from the model plant Arabidopsis thaliana. The assay uses labeled DNA substrates containing a single damaged base within a restriction site, and allows detection of fully repaired molecules as well as DNA repair intermediates. The method is easily applied to measure the repair activity of purified proteins and can be successfully used in combination with the extensive array of biological resources available for Arabidopsis.

  3. Chemical genetics and its potential in cardiac stem cell therapy.

    PubMed

    Vieira, Joaquim M; Riley, Paul R

    2013-05-01

    Over the last decade or so, intensive research in cardiac stem cell biology has led to significant discoveries towards a potential therapy for cardiovascular disease; the main cause of morbidity and mortality in humans. The major goal within the field of cardiovascular regenerative medicine is to replace lost or damaged cardiac muscle and coronaries following ischaemic disease. At present, de novo cardiomyocytes can be generated either in vitro, for cell transplantation or disease modelling using directed differentiation of embryonic stem cells or induced pluripotent stem cells, or in vivo via direct reprogramming of resident adult cardiac fibroblast or ectopic stimulation of resident cardiac stem or progenitor cells. A major bottleneck with all of these approaches is the low efficiency of cardiomyocyte differentiation alongside their relative functional immaturity. Chemical genetics, and the application of phenotypic screening with small molecule libraries, represent a means to enhance understanding of the molecular pathways controlling cardiovascular cell differentiation and, moreover, offer the potential for discovery of new drugs to invoke heart repair and regeneration. Here, we review the potential of chemical genetics in cardiac stem cell therapy, highlighting not only the major contributions to the field so far, but also the future challenges.

  4. 3D printed complex tissue construct using stem cell-laden decellularized extracellular matrix bioinks for cardiac repair.

    PubMed

    Jang, Jinah; Park, Hun-Jun; Kim, Seok-Won; Kim, Heejin; Park, Ju Young; Na, Soo Jin; Kim, Hyeon Ji; Park, Moon Nyeo; Choi, Seung Hyun; Park, Sun Hwa; Kim, Sung Won; Kwon, Sang-Mo; Kim, Pum-Joon; Cho, Dong-Woo

    2017-01-01

    Stem cell therapy is a promising therapeutic method for the treatment of ischemic heart diseases; however, some challenges prohibit the efficacy after cell delivery due to hostile microenvironment of the injured myocardium. 3D printed pre-vascularized stem cell patch can enhance the therapeutic efficacy for cardiac repair through promotion of rapid vascularization after patch transplantation. In this study, stem cell-laden decellularized extracellular matrix bioinks are used in 3D printing of pre-vascularized and functional multi-material structures. The printed structure composed of spatial patterning of dual stem cells improves cell-to-cell interactions and differentiation capability and promotes functionality for tissue regeneration. The developed stem cell patch promoted strong vascularization and tissue matrix formation in vivo. The patterned patch exhibited enhanced cardiac functions, reduced cardiac hypertrophy and fibrosis, increased migration from patch to the infarct area, neo-muscle and capillary formation along with improvements in cardiac functions. Therefore, pre-vascularized stem cell patch provides cardiac niche-like microenvironment, resulting in beneficial effects on cardiac repair.

  5. Expression of potentially lethal damage in Chinese hamster cells exposed to hematoporphyrin derivative photodynamic therapy.

    PubMed

    Gomer, C J; Rucker, N; Ferrario, A; Murphree, A L

    1986-07-01

    Experiments were performed to determine whether the expression and/or repair of potentially lethal damage could be observed in mammalian cells exposed to hemataporphyrin derivative (HPD) photodynamic therapy (PDT). Photodynamic therapy was combined with posttreatment protocols known to inhibit the repair of potentially lethal damage in cells treated with X-rays, ultraviolet radiation, or alkylating agents. Potentiation of lethal damage from photodynamic therapy was induced by hypothermia (4 degrees C) following short (1 h) or extended (16 h) HPD incubation conditions. Caffeine potentiated the lethal effects of PDT only when cells were incubated with HPD for extended time periods. However, 3-aminobenzamide had no effect on the cytotoxic actions of PDT following either short or extended HPD incubations. Recovery from potentially lethal damage expressed by posttreatment hypothermia was complete within 1 h, while recovery from potentially lethal damage expressed by posttreatment caffeine required time periods of up to 24 h. The lack of effect of 3-aminobenzamide on expression of potentially lethal damage following photodynamic therapy may be related to direct inhibition of adenosine diphosphoribose transferase by photodynamic therapy. These results indicate that the expression and repair of potentially lethal damage can be observed in cells treated with PDT and will vary as a function of porphyrin incubation conditions.

  6. Lung capillary injury and repair in left heart disease: a new target for therapy?

    PubMed

    Azarbar, Sayena; Dupuis, Jocelyn

    2014-07-01

    The lungs are the primary organs affected in LHD (left heart disease). Increased left atrial pressure leads to pulmonary alveolar-capillary stress failure, resulting in cycles of alveolar wall injury and repair. The reparative process causes the proliferation of MYFs (myofibroblasts) with fibrosis and extracellular matrix deposition, resulting in thickening of the alveolar wall. Although the resultant reduction in vascular permeability is initially protective against pulmonary oedema, the process becomes maladaptive causing a restrictive lung syndrome with impaired gas exchange. This pathological process may also contribute to PH (pulmonary hypertension) due to LHD. Few clinical trials have specifically evaluated lung structural remodelling and the effect of related therapies in LHD. Currently approved treatment for chronic HF (heart failure) may have direct beneficial effects on lung structural remodelling. In the future, novel therapies specifically targeting the remodelling processes may potentially be utilized. In the present review, we summarize data supporting the clinical importance and pathophysiological mechanisms of lung structural remodelling in LHD and propose that this pathophysiological process should be explored further in pre-clinical studies and future therapeutic trials.

  7. Light-emitting diode therapy increases collagen deposition during the repair process of skeletal muscle.

    PubMed

    de Melo, Claudia Aparecida Viana; Alves, Agnelo Neves; Terena, Stella Maris Lins; Fernandes, Kristianne Porta Santos; Nunes, Fábio Daumas; da Silva, Daniela de Fátima Teixeira; Bussadori, Sandra Kalil; Deana, Alessandro Melo; Mesquita-Ferrari, Raquel Agnelli

    2016-04-01

    This study analyzed the effects of light-emitting diode (LED) therapy on the morphology of muscle tissue as well as collagen remodeling and matrix metalloproteinase 2 (MMP-2) activity in the skeletal muscle of rats following acute injury. Wistar rats were divided into four groups: (1) control, (2) sham, (3) untreated cryoinjury, and (4) cryoinjury treated with LED. Cryoinjury was induced by two applications of a metal probe cooled in liquid nitrogen directly onto the belly of the tibialis anterior muscle. For treatment, the LED equipment (wavelength 850 nm, output power 30 mW, and total energy 3.2 J) was used daily. The study periods were 1, 3, and 7 days after cryoinjury. Morphological aspects were evaluated through hematoxylin-eosin staining. The amount of collagen fibers was evaluated using Picro Sirius Red staining under polarized light. The gelatinase activity of MMP-2 was evaluated using zymography. The results showed significant reductions in inflammatory infiltrate after 3 days and an increased number of immature muscle fibers after 7 days. Furthermore, treatment induced a reduction in the gelatinolytic activity of MMP-2 after 1, 3, and 7 days in comparison to the untreated injury groups and increased the collagen deposition after 3 and 7 days in the treated groups. LED therapy at 850 nm induced a significant reduction in inflammation, decreased MMP-2 activity, and increased the amount of immature muscle and collagen fibers during the muscle repair process following acute injury.

  8. Treating hearing disorders with cell and gene therapy

    NASA Astrophysics Data System (ADS)

    Gillespie, Lisa N.; Richardson, Rachael T.; Nayagam, Bryony A.; Wise, Andrew K.

    2014-12-01

    Hearing loss is an increasing problem for a substantial number of people and, with an aging population, the incidence and severity of hearing loss will become more significant over time. There are very few therapies currently available to treat hearing loss, and so the development of new therapeutic strategies for hearing impaired individuals is of paramount importance to address this unmet clinical need. Most forms of hearing loss are progressive in nature and therefore an opportunity exists to develop novel therapeutic approaches to slow or halt hearing loss progression, or even repair or replace lost hearing function. Numerous emerging technologies have potential as therapeutic options. This paper details the potential of cell- and gene-based therapies to provide therapeutic agents to protect sensory and neural cells from various insults known to cause hearing loss; explores the potential of replacing lost sensory and nerve cells using gene and stem cell therapy; and describes the considerations for clinical translation and the challenges that need to be overcome.

  9. Adoptive cell transfer therapy for malignant gliomas.

    PubMed

    Ishikawa, Eiichi; Takano, Shingo; Ohno, Tadao; Tsuboi, Koji

    2012-01-01

    To date, various adoptive immunotherapies have been attempted for treatment of malignant gliomas using nonspecific and/or specific effector cells. Since the late 1980s, with the development of rIL-2, the efficacy of lymphokine-activated killer (LAK) cell therapy with or without rIL-2 for malignant gliomas had been tested with some modifications in therapeutic protocols. With advancements in technology, ex vivo expanded tumor specific cytotoxic T-lymphocytes (CTL) or those lineages were used in clinical trials with higher tumor response rates. In addition, combinations of those adoptive cell transfer using LAK cells, CTLs or natural killer (NK) cells with autologous tumor vaccine (ATV) therapy were attempted. Also, a strategy of high-dose (or lymphodepleting) chemotherapy followed by adoptive cell transfer has been drawing attentions recently. The most important role of these clinical studies using cell therapy was to prove that these ex vivo expanded effector cells could kill tumor cells in vivo. Although recent clinical results could demonstrate radiologic tumor shrinkage in a number of cases, cell transfer therapy alone has been utilized less frequently, because of the high cost of ex vivo cell expansion, the short duration of antitumor activity in vivo, and the recent shift of interest to vaccine immunotherapy. Nevertheless, NK cell therapy using specific feeder cells or allergenic NK cell lines have potentials to be a good choice of treatment because of easy ex vivo expansion and their efficacy especially when combined with vaccine therapy as they are complementary to each other. Also, further studies are expected to clarify the efficacy of the high-dose chemotherapy followed by a large scale cell transfer therapy as a new therapeutic strategy for malignant gliomas.

  10. Early sensory re-education of the hand after peripheral nerve repair based on mirror therapy: a randomized controlled trial

    PubMed Central

    Paula, Mayara H.; Barbosa, Rafael I.; Marcolino, Alexandre M.; Elui, Valéria M. C.; Rosén, Birgitta; Fonseca, Marisa C. R.

    2016-01-01

    BACKGROUND: Mirror therapy has been used as an alternative stimulus to feed the somatosensory cortex in an attempt to preserve hand cortical representation with better functional results. OBJECTIVE: To analyze the short-term functional outcome of an early re-education program using mirror therapy compared to a late classic sensory program for hand nerve repair. METHOD: This is a randomized controlled trial. We assessed 20 patients with median and ulnar nerve and flexor tendon repair using the Rosen Score combined with the DASH questionnaire. The early phase group using mirror therapy began on the first postoperative week and lasted 5 months. The control group received classic sensory re-education when the protective sensation threshold was restored. All participants received a patient education booklet and were submitted to the modified Duran protocol for flexor tendon repair. The assessments were performed by the same investigator blinded to the allocated treatment. Mann-Whitney Test and Effect Size using Cohen's d score were used for inter-group comparisons at 3 and 6 months after intervention. RESULTS: The primary outcome (Rosen score) values for the Mirror Therapy group and classic therapy control group after 3 and 6 months were 1.68 (SD=0.5); 1.96 (SD=0.56) and 1.65 (SD=0.52); 1.51 (SD=0.62), respectively. No between-group differences were observed. CONCLUSION: Although some clinical improvement was observed, mirror therapy was not shown to be more effective than late sensory re-education in an intermediate phase of nerve repair in the hand. Replication is needed to confirm these findings. PMID:26786080

  11. Th2 cells are essential for modulation of vascular repair by allogeneic endothelial cells

    PubMed Central

    Methe, Heiko; Nanasato, Mamoru; Spognardi, Anna-Maria; Groothuis, Adam; Edelman, Elazer R.

    2009-01-01

    Background Endothelial cells (EC) embedded within three-dimensional matrices (MEEC) when placed in the vascular adventitia control lumenal inflammation and intimal hyperplasia. Matrix-embedding alters endothelial immunogenicity in vitro. T helper (Th) driven host immunity is a major impediment for of allogeneic grafts. We therefore aimed to identify if modulation of T helper balance would affect immune compatibility and endothelial regulation of vascular repair in vivo. Methods Pigs (n=4/group) underwent balloon injury of both carotid arteries and were left alone (group 1) or received perivascular implants of porcine MEEC (group 2), a 12 days course of cyclosporine A (CsA) (group 3), or a combination of MEEC and CsA (group 4). Host immune reactivity (EC-specific antibodies, activation of splenocytes) was analyzed after 28 and 90 days in 2 pigs/group respectively. Results MEEC treatment alone induced formation of EC-specific IgG1-antibodies (41±6 mean fluorescence intensity (MFI)) and differentiation of host splenocytes into Th2, but not Th1, cytokine-producing cells (IL-4: 242±102, IL-10: 273±114 number of spots). Concomitant CsA-therapy reduced the frequency of IgG1-antibodies (25±2 MFI; p<0.02) and Th2-cytokine producing splenocytes upon MEEC treatment (IL-4: 157±19, IL-10: 124±26 number of spots; p< 0.05). MEEC significantly inhibited luminal occlusion 28 and 90 days after balloon injury compared to untreated controls (12±7 vs. 68±14%; p<0.001) but to a lesser extent in the face of immunomodulation with concomitant CsA-treatment (34±13%; p<0.02 vs. group 2). Conclusions MEEC do not induce a significant Th1-driven immune response expected from alloimplants, but do enhance differentiation of splenocytes into Th2-cytokine producing cells. Reduction in this Th2 response reduces the vasoregulatory effects of allogeneic EC after injury. PMID:20036161

  12. Self assembling bioactive materials for cell adhesion in tissue repair

    NASA Astrophysics Data System (ADS)

    Hwang, Julia J.

    This work involved the study of biodegradable and biocompatible materials that have the potential to modify tissue engineering scaffolds through self assembly, generating multiple layers that deliver bioactivity. Diblock biomaterials containing cholesteryl moieties and oligomers of lactic acid units were found to form single crystals when precipitated from hot ethanol and smectic liquid crystalline phases when cast as a film. Cell culture experiments on these films with 3T3 and 3T6 fibroblasts indicated that these ordered materials form surfaces with specific chemistries that favored cell adhesion, spreading, and proliferation suggesting the potential of mediating human tissue repair. The author believes the cholesteryl moieties found on the surface play a key role in determining cell behavior. Cholesteryl-(L-lactic acid) diblock molecules were then functionalized with moieties including vitamin Bx, cholesterol, and the anti-inflammatory drug indomethacin. An unstable activated ester between indomethacin and the diblock molecule resulted in the release of indomethacin into the culture medium which inhibited the proliferation of 3T3 fibroblasts. Finally, a series of molecules were designed to incorporate dendrons based on amino acids at the termini of the diblock structures. It was determined that lysine, a basic amino acid, covalently coupled to cholesteryl-(L-lactic acid) can promote cell adhesion and spreading while negatively charged and zwitterionic 2nd generation dendrons based on aspartic acid do not. Incorporation of the well known arginine-glycine-aspartic acid (RGD) sequence, which is found in many adhesive proteins, to the dendrons imparted integrin-mediated cell adhesion as evidenced by the formation of stress fibers. We also explored the capacity of integrin receptors to bind to ligands that are not the linear form of RGD, but have R, G, and D spatially positioned to mimic the linear RGD environments. For this purpose, the arms of the 2 nd generation

  13. Global Manufacturing of CAR T Cell Therapy.

    PubMed

    Levine, Bruce L; Miskin, James; Wonnacott, Keith; Keir, Christopher

    2017-03-17

    Immunotherapy using chimeric antigen receptor-modified T cells has demonstrated high response rates in patients with B cell malignancies, and chimeric antigen receptor T cell therapy is now being investigated in several hematologic and solid tumor types. Chimeric antigen receptor T cells are generated by removing T cells from a patient's blood and engineering the cells to express the chimeric antigen receptor, which reprograms the T cells to target tumor cells. As chimeric antigen receptor T cell therapy moves into later-phase clinical trials and becomes an option for more patients, compliance of the chimeric antigen receptor T cell manufacturing process with global regulatory requirements becomes a topic for extensive discussion. Additionally, the challenges of taking a chimeric antigen receptor T cell manufacturing process from a single institution to a large-scale multi-site manufacturing center must be addressed. We have anticipated such concerns in our experience with the CD19 chimeric antigen receptor T cell therapy CTL019. In this review, we discuss steps involved in the cell processing of the technology, including the use of an optimal vector for consistent cell processing, along with addressing the challenges of expanding chimeric antigen receptor T cell therapy to a global patient population.

  14. Angiogenic Mechanisms of Human CD34(+) Stem Cell Exosomes in the Repair of Ischemic Hindlimb.

    PubMed

    Mathiyalagan, Prabhu; Liang, Yaxuan; Kim, David; Misener, Sol; Thorne, Tina; Kamide, Christine; Klyachko, Ekaterina; Losordo, Douglas W; Hajjar, Roger J; Sahoo, Susmita

    2017-03-15

    Rationale: Paracrine secretions appear to mediate therapeutic effects of human CD34(+) stem cells locally transplanted in patients with myocardial and critical limb ischemia as well as in animal models. Earlier, we had discovered that paracrine secretion from human CD34(+) cells contains pro-angiogenic, membrane-bound nano-vesicles called exosomes (CD34Exo). Objective: Here, we investigated the mechanisms of CD34Exo-mediated ischemic tissue repair and therapeutic angiogenesis by studying their miRNA content and uptake. Methods and Results: When injected into mouse ischemic hindlimb tissue, CD34Exo, but not the CD34exo-depleted conditioned media, mimicked the beneficial activity of their parent cells by improving ischemic limb perfusion, capillary density, motor function and their amputation. CD34Exo were found to be enriched with pro-angiogenic miRNAs such as miR-126-3p. Knocking down miR-126-3p from CD34exo abolished their angiogenic activity and beneficial function both in vitro and in vivo. Interestingly, injection of CD34Exo increased miR-126-3p levels in mouse ischemic limb, but did not affect the endogenous synthesis of miR-126-3p suggesting a direct transfer of stable and functional exosomal miR-126-3p. miR-126-3p enhanced angiogenesis by suppressing the expression of its known target, SPRED1; simultaneously modulating the expression of genes involved in angiogenic pathways such as VEGF, ANG1, ANG2, MMP9, TSP1 etc. Interestingly, CD34Exo, when treated to ischemic hindlimbs, were most efficiently internalized by endothelial cells relative to smooth muscle cells and fibroblasts demonstrating a direct role of stem cell-derived exosomes on mouse endothelium at the cellular level. Conclusions: Collectively, our results have demonstrated a novel mechanism by which cell-free CD34Exo mediates ischemic tissue repair via beneficial angiogenesis. Exosome-shuttled angiomiRs may signify amplification of stem cell function and may explain the angiogenic and therapeutic

  15. DSB (Im)mobility and DNA repair compartmentalization in mammalian cells.

    PubMed

    Lemaître, Charlène; Soutoglou, Evi

    2015-02-13

    Chromosomal translocations are considered as causal in approximately 20% of cancers. Therefore, understanding their mechanisms of formation is crucial in the prevention of carcinogenesis. The first step of translocation formation is the concomitant occurrence of double-strand DNA breaks (DSBs) in two different chromosomes. DSBs can be repaired by different repair mechanisms, including error-free homologous recombination (HR), potentially error-prone non-homologous end joining (NHEJ) and the highly mutagenic alternative end joining (alt-EJ) pathways. Regulation of DNA repair pathway choice is crucial to avoid genomic instability. In yeast, DSBs are mobile and can scan the entire nucleus to be repaired in specialized DNA repair centers or if they are persistent, in order to associate with the nuclear pores or the nuclear envelope where they can be repaired by specialized repair pathways. DSB mobility is limited in mammals; therefore, raising the question of whether the position at which a DSB occurs influences its repair. Here, we review the recent literature addressing this question. We first present the reports describing the extent of DSB mobility in mammalian cells. In a second part, we discuss the consequences of non-random gene positioning on chromosomal translocations formation. In the third part, we discuss the mobility of heterochromatic DSBs in light of our recent data on DSB repair at the nuclear lamina, and finally, we show that DSB repair compartmentalization at the nuclear periphery is conserved from yeast to mammals, further pointing to a role for gene positioning in the outcome of DSB repair. When regarded as a whole, the different studies reviewed here demonstrate the importance of nuclear architecture on DSB repair and reveal gene positioning as an important parameter in the study of tumorigenesis.

  16. Current Biosafety Considerations in Stem Cell Therapy

    PubMed Central

    Mousavinejad, Masoumeh; Andrews, Peter W.; Shoraki, Elham Kargar

    2016-01-01

    Stem cells can be valuable model systems for drug discovery and modelling human diseases as well as to investigate cellular interactions and molecular events in the early stages of development. Controlling the differentiation of stem cells into specific germ layers provides a potential source of highly specialized cells for therapeutic applications. In recent years, finding individual properties of stem cells such as their ultimate self-renewal capacity and the generation of particular cell lines by differentiation under specific culture conditions underpins the development of regenerative therapies. These futures make stem cells a leading candidate to treat a wide range of diseases. Nevertheless, as with all novel treatments, safety issues are one of the barriers that should be overcome to guarantee the quality of a patient’s life after stem cell therapy. Many studies have pointed to a large gap in our knowledge about the therapeutic applications of these cells. This gap clearly shows the importance of biosafety concerns for the current status of cell-based therapies, even more than their therapeutic efficacy. Currently, scientists report that tumorigenicity and immunogenicity are the two most important associated cell-based therapy risks. In principle, intrinsic factors such as cell characteristics and extrinsic elements introduced by manufacturing of stem cells can result in tumor formation and immunological reactions after stem cell transplantation. Therapeutic research shows there are many biological questions regarding safety issues of stem cell clinical applications. Stem cell therapy is a rapidly advancing field that needs to focus more on finding a comprehensive technology for assessing risk. A variety of risk factors (from intrinsic to extrinsic) should be considered for safe clinical stem cell therapies. PMID:27540533

  17. ATM prevents DSB formation by coordinating SSB repair and cell cycle progression.

    PubMed

    Khoronenkova, Svetlana V; Dianov, Grigory L

    2015-03-31

    DNA single-strand breaks (SSBs) arise as a consequence of spontaneous DNA instability and are also formed as DNA repair intermediates. Their repair is critical because they otherwise terminate gene transcription and generate toxic DNA double-strand breaks (DSBs) on replication. To prevent the formation of DSBs, SSB repair must be completed before DNA replication. To accomplish this, cells should be able to detect unrepaired SSBs, and then delay cell cycle progression to allow more time for repair; however, to date there is no evidence supporting the coordination of SSB repair and replication in human cells. Here we report that ataxia-telangiectasia mutated kinase (ATM) plays a major role in restricting the replication of SSB-containing DNA and thus prevents DSB formation. We show that ATM is activated by SSBs and coordinates their repair with DNA replication. SSB-mediated ATM activation is followed by a G1 cell cycle delay that allows more time for repair and thus prevents the replication of damaged DNA and DSB accrual. These findings establish an unanticipated role for ATM in the signaling of DNA SSBs and provide important insight into the molecular defects leading to genetic instability in patients with ataxia-telangiectasia.

  18. Stem cells: are we ready for therapy?

    PubMed

    Schroeder, Insa S

    2014-01-01

    Cell therapy as a replacement for diseased or destroyed endogenous cells is a major component of regenerative medicine. Various types of stem cells are or will be used in clinical settings as autologous or allogeneic products. In this chapter, the progress that has been made to translate basic stem cell research into pharmaceutical manufacturing processes will be reviewed. Even if in public perception, embryonic stem (ES) cells and more recently induced pluripotent stem (iPS) cells dominate the field of regenerative medicine and will be discussed in great detail, it is the adult stem cells that are used for decades as therapeutics. Hence, these cells will be compared to ES and iPS cells. Finally, special emphasis will be placed on the scientific, technical, and economic challenges of developing stem cell-based in vitro model systems and cell therapies that can be commercialized.

  19. Fibroblast growth factor type 2 signaling is critical for DNA repair in human keratinocyte stem cells.

    PubMed

    Harfouche, Ghida; Vaigot, Pierre; Rachidi, Walid; Rigaud, Odile; Moratille, Sandra; Marie, Mélanie; Lemaitre, Gilles; Fortunel, Nicolas O; Martin, Michèle T

    2010-09-01

    Tissue stem cells must be endowed with superior maintenance and repair systems to ensure genomic stability over multiple generations, which would be less necessary in more differentiated cells. We previously reported that human keratinocyte stem cells were more resistant to ionizing radiation toxicity than their direct progeny, the keratinocyte progenitor cells. In the present study we addressed the mechanisms underlying this difference. Investigations of DNA repair showed that both single and double DNA strand breaks were repaired more rapidly and more efficiently in stem cells than in progenitors. As cell signaling is a key regulatory step in the management of DNA damage, a gene profiling study was performed. Data revealed that several genes of the fibroblast growth factor type 2 (FGF2) signaling pathway were induced by DNA damage in stem cells and not in progenitors. Furthermore, an increased content of the FGF2 protein was found in irradiated stem cells, both for the secreted and the cellular forms of the protein. To examine the role of endogenous FGF2 in DNA repair, stem cells were exposed to FGF2 pathway inhibitors. Blocking the FGF2 receptor (FGF receptor 1) or the kinase (Ras-mitogen-activated protein kinase 1) resulted in a inhibition of single and double DNA strand-break repair in the keratinocyte stem cells. Moreover, supplementing the progenitor cells with exogenous FGF2 activated their DNA repair. We propose that, apart from its well-known role as a strong mitogen and prosurvival factor, FGF2 helps to maintain genomic integrity in stem cells by activating stress-induced DNA repair.

  20. A novel cell death gene acts to repair patterning defects in Drosophila melanogaster.

    PubMed

    Tanaka, Kentaro M; Takahashi, Aya; Fuse, Naoyuki; Takano-Shimizu-Kouno, Toshiyuki

    2014-06-01

    Cell death is a mechanism utilized by organisms to eliminate excess cells during development. Here, we describe a novel regulator of caspase-independent cell death, Mabiki (Mabi), that is involved in the repair of the head patterning defects caused by extra copies of bicoid in Drosophila melanogaster. Mabiki functions together with caspase-dependent cell death mechanisms to provide robustness during development.

  1. Recent progress with the DNA repair mutants of Chinese hamster ovary cells

    SciTech Connect

    Thompson, L.H.; Salazar, E.P.; Brookman, K.W.; Collins, C.C.; Stewart, S.A.; Busch, D.B.; Weber, C.A.

    1986-04-02

    Repair deficient mutants of Chinese hamster ovary (CHO) cells are being used to identify human genes that correct the repair defects and to study mechanisms of DNA repair and mutagenesis. Five independent tertiary DNA transformants were obtained from the EM9 mutant. In these clones a human DNA sequence was identified that correlated with the resistance of the cells to CldUrd. After Eco RI digestion, Southern transfer, and hybridization of transformant DNAs with the BLUR-8 Alu family sequence, a common fragment of 25 to 30 kb was present. 37 refs., 4 figs., 3 tabs.

  2. Ultraviolet light-resistant primary transfectants of xeroderma pigmentosum cells are also DNA repair-proficient

    SciTech Connect

    Stark, M.; Naiman, T.; Canaani, D. )

    1989-08-15

    In a previous work, an immortal xeroderma pigmentosum cell line belonging to complementation group C was complemented to a UV-resistant phenotype by transfection with a human cDNA clone library. We now report that the primary transformants selected for UV-resistance also acquired normal levels of DNA repair. This was assessed both by measurement of UV-induced ({sup 3}H)thymidine incorporation and by equilibrium sedimentation analysis of repair-DNA synthesis. Therefore, the transduced DNA element which confers normal UV-resistance also corrects the excision repair defect of the xeroderma pigmentosum group C cell line.

  3. Modeling the induced mutation process in bacterial cells with defects in excision repair system

    NASA Astrophysics Data System (ADS)

    Bugay, A. N.; Vasilyeva, M. A.; Krasavin, E. A.; Parkhomenko, A. Yu.

    2015-12-01

    A mathematical model of the UV-induced mutation process in Escherichia coli cells with defects in the uvrA and polA genes has been developed. The model describes in detail the reaction kinetics for the excision repair system. The number of mismatches as a result of translesion synthesis is calculated for both wild-type and mutant cells. The effect of temporal modulation of the number of single-stranded DNA during postreplication repair has been predicted. A comparison of effectiveness of different repair systems has been conducted.

  4. Cell Therapy Products in Menopausal Medicine

    PubMed Central

    Choi, Hye Ji; Kim, Tae-Hee; Kim, Jun-Mo; Lee, Arum; Song, Hyeon Jin; Park, Yoo Jin

    2016-01-01

    The incidence of postmenopausal diseases increases with the age of women. In this review, we introduce cell therapy products, a new treatment for postmenopausal osteoporosis, which often occurs in postmenopausal women. We also figure out the trends of research on cell therapy products and emphasize the necessity and importance of this research for researchers and postmenopausal women. Finally, we suggest the direction for improvement of postmenopausal osteoporosis and research on cell therapy products. We investigated which medication have been used so far. We also examined the development and technical problems of technologies that are currently in use. PMID:27617240

  5. Platelets in tissue repair: control of apoptosis and interactions with regenerative cells.

    PubMed

    Gawaz, Meinrad; Vogel, Sebastian

    2013-10-10

    Besides mediating primary hemostasis and thrombosis, platelets play a critical role in tissue repair and regeneration. They regulate fundamental mechanisms involved in the healing process including cellular migration, proliferation, and angiogenesis. Control of apoptosis/cell survival and interaction with progenitor cells, which are clinically relevant but poorly understood aspects of platelets in tissue repair, will be highlighted in this review. Gaining deeper insight into the less well-characterized molecular mechanisms is necessary to develop new therapeutic platelet-based options.

  6. Tumor Cell Death Mediated by Peptides That Recognize Branched Intermediates of DNA Replication and Repair

    PubMed Central

    Dey, Mamon; Segall, Anca M.

    2013-01-01

    Effective treatments for cancer are still needed, both for cancers that do not respond well to current therapeutics and for cancers that become resistant to available treatments. Herein we investigated the effect of a structure-selective d-amino acid peptide wrwycr that binds replication fork mimics and Holliday Junction (HJs) intermediates of homologous recombination (HR) in vitro, and inhibits their resolution by HJ-processing enzymes. We predicted that treating cells with HJ-binding compounds would lead to accumulation of DNA damage. As cells repair endogenous or exogenous DNA damage, collapsed replication forks and HJ intermediates will accumulate and serve as targets for the HJ-binding peptides. Inhibiting junction resolution will lead to further accumulation of DNA breaks, eventually resulting in amplification of the damage and causing cell death. Both peptide wrwycr and the related wrwyrggrywrw entered cancer cells and reduced cell survival in a dose- and time-dependent manner. Early markers for DNA damage, γH2AX foci and 53BP1 foci, increased with dose and/or time exposure to the peptides. DNA breaks persisted at least 48 h, and both checkpoint proteins Chk1 and Chk2 were activated. The passage of the cells from S to G2/M was blocked even after 72 h. Apoptosis, however, was not induced in either HeLa or PC3 cells. Based on colony-forming assays, about 35% peptide-induced cytotoxicity was irreversible. Finally, sublethal doses of peptide wrwycr (50–100 µM) in conjunction with sublethal doses of several DNA damaging agents (etoposide, doxorubicin, and HU) reduced cell survival at least additively and sometimes synergistically. Taken together, the results suggest that the peptides merit further investigation as proof-of-principle molecules for a new class of anti-cancer therapeutics, in particular in combination with other DNA damaging therapies. PMID:24244353

  7. Quality cell therapy manufacturing by design.

    PubMed

    Lipsitz, Yonatan Y; Timmins, Nicholas E; Zandstra, Peter W

    2016-04-01

    Transplantation of live cells as therapeutic agents is poised to offer new treatment options for a wide range of acute and chronic diseases. However, the biological complexity of cells has hampered the translation of laboratory-scale experiments into industrial processes for reliable, cost-effective manufacturing of cell-based therapies. We argue here that a solution to this challenge is to design cell manufacturing processes according to quality-by-design (QbD) principles. QbD integrates scientific knowledge and risk analysis into manufacturing process development and is already being adopted by the biopharmaceutical industry. Many opportunities to incorporate QbD into cell therapy manufacturing exist, although further technology development is required for full implementation. Linking measurable molecular and cellular characteristics of a cell population to final product quality through QbD is a crucial step in realizing the potential for cell therapies to transform healthcare.

  8. Biochemical DSB-repair model for mammalian cells in G1 and early S phases of the cell cycle.

    PubMed

    Taleei, Reza; Nikjoo, Hooshang

    2013-08-30

    The paper presents a model of double strand breaks (DSB) repair in G1 and early S phases of the cell cycle. The model is based on a plethora of published information on biochemical modification of DSB induced by ionizing radiation. So far, three main DSB repair pathways have been identified, including nonhomologous end-joining (NHEJ), homologous recombination (HR), and microhomology-mediated end-joining (MMEJ). During G1 and early S phases of the cell cycle, NHEJ and MMEJ repair pathways are activated dependent on the type of double strand breaks. Simple DSB are a substrate for NHEJ, while complex DSB and DSB in heterochromatin require further end processing. Repair of all DSB start with NHEJ presynaptic processes, and depending on the type of DSB pursue simple ligation, further end processing prior to ligation, or resection. Using law of mass action the model is translated into a mathematical formalism. The solution of the formalism provides the step by step and overall repair kinetics. The overall repair kinetics are compared with the published experimental measurements. Our calculations are in agreement with the experimental results and show that the complex types of DSBs are repaired with slow repair kinetics. The G1 and early S phase model could be employed to predict the kinetics of DSB repair for damage induced by high LET radiation.

  9. Repair of potentially lethal radiation damage in human squamous carcinoma cells after chronic hypoxia

    SciTech Connect

    Kwok, Tim Tak; Sutherland, R.M. )

    1994-05-15

    The purpose of this study was to examine the repair of radiation-induced potentially lethal damage in A431 and CaSki cells after chronic hypoxia. Cells in exponential phase are subjected to hypoxia (<10 ppm oxygen) for up to 12 h and then are allowed to reoxygenate in air for up to 4 h. Cells are then irradiated with [gamma] rays. Cell survivals are measured by clonogenic assay immediately and at different times after irradiation. Compared to aerobic controls, an increase in the level of potentially lethal damage repair (PLDR) is demonstrated in A431 cells reoxygenated for 10 min after >4 h of hypoxia. The repair returned to aerobic control level by 3 h of reoxygenation. PLDR of A431 cells reached maximum at about 9 h after irradiation in cells reoxygenated for 10 min after hypoxia. However, the repair is maximum at 6 h in cells reoxygenated for 3 h after hypoxia and in aerobic cells not previously exposed to hypoxia. Reoxygenation after chronic hypoxia did not affect the PLDR capacity and repair kinetics of CaSki cells. The results suggest that radiosensitization by reoxygenation after chronic hypoxia is not related to inhibition of PLDR. 14 refs., 3 figs.

  10. Defective bone repair in mast cell-deficient Cpa3Cre/+ mice

    PubMed Central

    Chan, Daniel; Samberg, Robert; Abou-Rjeili, Mira; Wong, Timothy H.; Li, Ailian; Feyerabend, Thorsten B.; Rodewald, Hans-Reimer; Henderson, Janet E.; Martineau, Paul A.

    2017-01-01

    In the adult skeleton, cells of the immune system interact with those of the skeleton during all phases of bone repair to influence the outcome. Mast cells are immune cells best known for their pathologic role in allergy, and may be involved in chronic inflammatory and fibrotic disorders. Potential roles for mast cells in tissue homeostasis, vascularization and repair remain enigmatic. Previous studies in combined mast cell- and Kit-deficient KitW-sh/W-sh mice (KitW-sh) implicated mast cells in bone repair but KitW-sh mice suffer from additional Kit-dependent hematopoietic and non- hematopoietic deficiencies that could have confounded the outcome. The goal of the current study was to compare bone repair in normal wild type (WT) and Cpa3Cre/+ mice, which lack mast cells in the absence of any other hematopoietic or non- hematopoietic deficiencies. Repair of a femoral window defect was characterized using micro CT imaging and histological analyses from the early inflammatory phase, through soft and hard callus formation, and finally the remodeling phase. The data indicate 1) mast cells appear in healing bone of WT mice but not Cpa3Cre/+ mice, beginning 14 days after surgery; 2) re-vascularization of repair tissue and deposition of mineralized bone was delayed and dis-organised in Cpa3Cre/+ mice compared with WT mice; 3) the defects in Cpa3Cre/+ mice were associated with little change in anabolic activity and biphasic alterations in osteoclast and macrophage activity. The outcome at 56 days postoperative was complete bridging of the defect in most WT mice and fibrous mal-union in most Cpa3Cre/+ mice. The results indicate that mast cells promote bone healing, possibly by recruiting vascular endothelial cells during the inflammatory phase and coordinating anabolic and catabolic activity during tissue remodeling. Taken together the data indicate that mast cells have a positive impact on bone repair. PMID:28350850

  11. Cell Therapy in Ischemic Heart Disease: Interventions That Modulate Cardiac Regeneration

    PubMed Central

    Schaun, Maximiliano I.; Eibel, Bruna; Kristocheck, Melissa; Sausen, Grasiele; Machado, Luana; Koche, Andreia; Markoski, Melissa M.

    2016-01-01

    The incidence of severe ischemic heart disease caused by coronary obstruction has progressively increased. Alternative forms of treatment have been studied in an attempt to regenerate myocardial tissue, induce angiogenesis, and improve clinical conditions. In this context, cell therapy has emerged as a promising alternative using cells with regenerative potential, focusing on the release of paracrine and autocrine factors that contribute to cell survival, angiogenesis, and tissue remodeling. Evidence of the safety, feasibility, and potential effectiveness of cell therapy has emerged from several clinical trials using different lineages of adult stem cells. The clinical benefit, however, is not yet well established. In this review, we discuss the therapeutic potential of cell therapy in terms of regenerative and angiogenic capacity after myocardial ischemia. In addition, we addressed nonpharmacological interventions that may influence this therapeutic practice, such as diet and physical training. This review brings together current data on pharmacological and nonpharmacological approaches to improve cell homing and cardiac repair. PMID:26880938

  12. Percutaneous Mitral Valve Repair in Mitral Regurgitation Reduces Cell-Free Hemoglobin and Improves Endothelial Function

    PubMed Central

    Rammos, Christos; Zeus, Tobias; Balzer, Jan; Kubatz, Laura; Hendgen-Cotta, Ulrike B.; Veulemans, Verena; Hellhammer, Katharina; Totzeck, Matthias; Luedike, Peter; Kelm, Malte; Rassaf, Tienush

    2016-01-01

    Background and Objective Endothelial dysfunction is predictive for cardiovascular events and may be caused by decreased bioavailability of nitric oxide (NO). NO is scavenged by cell-free hemoglobin with reduction of bioavailable NO up to 70% subsequently deteriorating vascular function. While patients with mitral regurgitation (MR) suffer from an impaired prognosis, mechanisms relating to coexistent vascular dysfunctions have not been described yet. Therapy of MR using a percutaneous mitral valve repair (PMVR) approach has been shown to lead to significant clinical benefits. We here sought to investigate the role of endothelial function in MR and the potential impact of PMVR. Methods and Results Twenty-seven patients with moderate-to-severe MR treated with the MitraClip® device were enrolled in an open-label single-center observational study. Patients underwent clinical assessment, conventional echocardiography, and determination of endothelial function by measuring flow-mediated dilation (FMD) of the brachial artery using high-resolution ultrasound at baseline and at 3-month follow-up. Patients with MR demonstrated decompartmentalized hemoglobin and reduced endothelial function (cell-free plasma hemoglobin in heme 28.9±3.8 μM, FMD 3.9±0.9%). Three months post-procedure, PMVR improved ejection fraction (from 41±3% to 46±3%, p = 0.03) and NYHA functional class (from 3.0±0.1 to 1.9±1.7, p<0.001). PMVR was associated with a decrease in cell free plasma hemoglobin (22.3±2.4 μM, p = 0.02) and improved endothelial functions (FMD 4.8±1.0%, p<0.0001). Conclusion We demonstrate here that plasma from patients with MR contains significant amounts of cell-free hemoglobin, which is accompanied by endothelial dysfunction. PMVR therapy is associated with an improved hemoglobin decompartmentalization and vascular function. PMID:26986059

  13. Urokinase plasminogen activator released by alveolar epithelial cells modulates alveolar epithelial repair in vitro.

    PubMed

    Van Leer, Coretta; Stutz, Monika; Haeberli, André; Geiser, Thomas

    2005-12-01

    Intra-alveolar fibrin is formed following lung injury and inflammation and may contribute to the development of pulmonary fibrosis. Fibrin turnover is altered in patients with pulmonary fibrosis, resulting in intra-alveolar fibrin accumulation, mainly due to decreased fibrinolysis. Alveolar type II epithelial cells (AEC) repair the injured alveolar epithelium by migrating over the provisional fibrin matrix. We hypothesized that repairing alveolar epithelial cells modulate the underlying fibrin matrix by release of fibrinolytic activity, and that the degree of fibrinolysis modulates alveolar epithelial repair on fibrin. To test this hypothesis we studied alveolar epithelial wound repair in vitro using a modified epithelial wound repair model with human A549 alveolar epithelial cells cultured on a fibrin matrix. In presence of the inflammatory cytokine interleukin-1beta, wounds increase by 800% in 24 hours mainly due to detachment of the cells, whereas in serum-free medium wound areas decreases by 22.4 +/- 5.2% (p < 0.01). Increased levels of D-dimer, FDP and uPA in the cell supernatant of IL-1beta-stimulated A549 epithelial cells indicate activation of fibrinolysis by activation of the plasmin system. In presence of low concentrations of fibrinolysis inhibitors, including specific blocking anti-uPA antibodies, alveolar epithelial repair in vitro was improved, whereas in presence of high concentrations of fibrinolysis inhibitors, a decrease was observed mainly due to decreased spreading and migration of cells. These findings suggest the existence of a fibrinolytic optimum at which alveolar epithelial repair in vitro is most efficient. In conclusion, uPA released by AEC alters alveolar epithelial repair in vitro by modulating the underlying fibrin matrix.

  14. Challenges for heart disease stem cell therapy

    PubMed Central

    Hoover-Plow, Jane; Gong, Yanqing

    2012-01-01

    Cardiovascular diseases (CVDs) are the leading cause of death worldwide. The use of stem cells to improve recovery of the injured heart after myocardial infarction (MI) is an important emerging therapeutic strategy. However, recent reviews of clinical trials of stem cell therapy for MI and ischemic heart disease recovery report that less than half of the trials found only small improvements in cardiac function. In clinical trials, bone marrow, peripheral blood, or umbilical cord blood cells were used as the source of stem cells delivered by intracoronary infusion. Some trials administered only a stem cell mobilizing agent that recruits endogenous sources of stem cells. Important challenges to improve the effectiveness of stem cell therapy for CVD include: (1) improved identification, recruitment, and expansion of autologous stem cells; (2) identification of mobilizing and homing agents that increase recruitment; and (3) development of strategies to improve stem cell survival and engraftment of both endogenous and exogenous sources of stem cells. This review is an overview of stem cell therapy for CVD and discusses the challenges these three areas present for maximum optimization of the efficacy of stem cell therapy for heart disease, and new strategies in progress. PMID:22399855

  15. Aurora-A controls cancer cell radio- and chemoresistance via ATM/Chk2-mediated DNA repair networks.

    PubMed

    Sun, Huizhen; Wang, Yan; Wang, Ziliang; Meng, Jiao; Qi, Zihao; Yang, Gong

    2014-05-01

    High expression of Aurora kinase A (Aurora-A) has been found to confer cancer cell radio- and chemoresistance, however, the underlying mechanism is unclear. In this study, by using Aurora-A cDNA/shRNA or the specific inhibitor VX680, we show that Aurora-A upregulates cell proliferation, cell cycle progression, and anchorage-independent growth to enhance cell resistance to cisplatin and X-ray irradiation through dysregulation of DNA damage repair networks. Mechanistic studies showed that Aurora-A promoted the expression of ATM/Chk2, but suppressed the expression of BRCA1/2, ATR/Chk1, p53, pp53 (Ser15), H2AX, γH2AX (Ser319), and RAD51. Aurora-A inhibited the focus formation of γH2AX in response to ionizing irradiation. Treatment of cells overexpressing Aurora-A and ATM/Chk2 with the ATM specific inhibitor KU-55933 increased the cell sensitivity to cisplatin and irradiation through increasing the phosphorylation of p53 at Ser15 and inhibiting the expression of Chk2, γH2AX (Ser319), and RAD51. Further study revealed that BRCA1/2 counteracted the function of Aurora-A to suppress the expression of ATM/Chk2, but to activate the expression of ATR/Chk1, pp53, γH2AX, and RAD51, leading to the enhanced cell sensitivity to irradiation and cisplatin, which was also supported by the results from animal assays. Thus, our data provide strong evidences that Aurora-A and BRCA1/2 inversely control the sensitivity of cancer cells to radio- and chemotherapy through the ATM/Chk2-mediated DNA repair networks, indicating that the DNA repair molecules including ATM/Chk2 may be considered for the targeted therapy against cancers with overexpression of Aurora-A.

  16. Repair synthesis by human cell extracts in DNA damaged by cis- and trans-diamminedichloroplatinum(II).

    PubMed Central

    Hansson, J; Wood, R D

    1989-01-01

    DNA damage was induced in closed circular plasmid DNA by treatment with cis- or trans-diamminedichloroplatinum(II). These plasmids were used as substrates in reactions to give quantitative measurements of DNA repair synthesis mediated by cell free extracts from human lymphoid cell lines. Adducts induced by both drugs stimulated repair synthesis in a dose dependent manner by an ATP-requiring process. Measurements by an isopycnic gradient sedimentation method gave an upper limit for the average patch sizes in this in vitro system of around 140 nucleotides. It was estimated that up to 3% of the drug adducts induce the synthesis of a repair patch. The repair synthesis is due to repair of a small fraction of frequent drug adducts, rather than extensive repair of a rare subclass of lesions. Nonspecific DNA synthesis in undamaged plasmids, caused by exonucleolytic degradation and resynthesis, was reduced by repeated purification of intact circular forms. An extract made from cells belonging to xeroderma pigmentosum complementation group A was deficient in repair synthesis in response to the presence of cis- or trans-diamminedichloroplatinum(II) adducts in DNA. Images PMID:2554251

  17. Multiple mechanisms contribute to double-strand break repair at rereplication forks in Drosophila follicle cells

    PubMed Central

    Alexander, Jessica L.; Beagan, Kelly; Orr-Weaver, Terry L.; McVey, Mitch

    2016-01-01

    Rereplication generates double-strand breaks (DSBs) at sites of fork collisions and causes genomic damage, including repeat instability and chromosomal aberrations. However, the primary mechanism used to repair rereplication DSBs varies across different experimental systems. In Drosophila follicle cells, developmentally regulated rereplication is used to amplify six genomic regions, two of which contain genes encoding eggshell proteins. We have exploited this system to test the roles of several DSB repair pathways during rereplication, using fork progression as a readout for DSB repair efficiency. Here we show that a null mutation in the microhomology-mediated end-joining (MMEJ) component, polymerase θ/mutagen-sensitive 308 (mus308), exhibits a sporadic thin eggshell phenotype and reduced chorion gene expression. Unlike other thin eggshell mutants, mus308 displays normal origin firing but reduced fork progression at two regions of rereplication. We also find that MMEJ compensates for loss of nonhomologous end joining to repair rereplication DSBs in a site-specific manner. Conversely, we show that fork progression is enhanced in the absence of both Drosophila Rad51 homologs, spindle-A and spindle-B, revealing homologous recombination is active and actually impairs fork movement during follicle cell rereplication. These results demonstrate that several DSB repair pathways are used during rereplication in the follicle cells and their contribution to productive fork progression is influenced by genomic position and repair pathway competition. Furthermore, our findings illustrate that specific rereplication DSB repair pathways can have major effects on cellular physiology, dependent upon genomic context. PMID:27849606

  18. Perspectives on stem cell-based elastic matrix regenerative therapies for abdominal aortic aneurysms.

    PubMed

    Bashur, Chris A; Rao, Raj R; Ramamurthi, Anand

    2013-06-01

    Abdominal aortic aneurysms (AAAs) are potentially fatal conditions that are characterized by decreased flexibility of the aortic wall due to proteolytic loss of the structural matrix. This leads to their gradual weakening and ultimate rupture. Drug-based inhibition of proteolytic enzymes may provide a nonsurgical treatment alternative for growing AAAs, although it might at best be sufficient to slow their growth. Regenerative repair of disrupted elastic matrix is required if regression of AAAs to a healthy state is to be achieved. Terminally differentiated adult and diseased vascular cells are poorly capable of affecting such regenerative repair. In this context, stem cells and their smooth muscle cell-like derivatives may represent alternate cell sources for regenerative AAA cell therapies. This article examines the pros and cons of using different autologous stem cell sources for AAA therapy, the requirements they must fulfill to provide therapeutic benefit, and the current progress toward characterizing the cells' ability to synthesize elastin, assemble elastic matrix structures, and influence the regenerative potential of diseased vascular cell types. The article also provides a detailed perspective on the limitations, uncertainties, and challenges that will need to be overcome or circumvented to translate current strategies for stem cell use into clinically viable AAA therapies. These therapies will provide a much needed nonsurgical treatment option for the rapidly growing, high-risk, and vulnerable elderly demographic.

  19. Survival of UV-irradiated mammalian cells correlates with efficient DNA repair in an essential gene

    SciTech Connect

    Bohr, V.A.; Okumoto, D.S.; Hanawalt, P.C.

    1986-06-01

    The survival of UV-irradiated mammalian cells is not necessarily correlated with their overall capacity to carry out DNA repair. Human cells typically remove 80% of the pyrimidine dimers produced by a UV dose of 5 J/m2 within 24 hr. In contrast, a Chinese hamster ovary (CHO) cell line survives UV irradiation equally well while removing only 15% of the dimers. Using a newly developed technique to measure dimer frequencies in single-copy specific sequences, we find that the CHO cells remove 70% of the dimers from the essential dihydrofolate reductase (DHFR) gene but only 20% from sequences located 30 kilobases or more upstream from the 5' end of the gene in a 24-hr period. Repair-deficient human cells from xeroderma pigmentosum complementation group C (XPC) are similar to the CHO cells in overall repair levels, but they are extremely sensitive to killing by UV irradiation. In the XPC cells, we find little or no repair in the DHFR gene; in contrast, in normal human fibroblasts and epidermal keratinocytes, greater than 80% of the dimers induced in the gene by 20 J/m2 are removed in 24 hr. Since the CHO and normal human cells exhibit similar UV resistance, much higher than that of XPC cells, our findings suggest a correlation between efficient repair of essential genes and resistance to DNA-damaging agents such as UV light.

  20. Electrical stimulation enhances cell migration and integrative repair in the meniscus

    NASA Astrophysics Data System (ADS)

    Yuan, Xiaoning; Arkonac, Derya E.; Chao, Pen-Hsiu Grace; Vunjak-Novakovic, Gordana

    2014-01-01

    Electrical signals have been applied towards the repair of articular tissues in the laboratory and clinical settings for over seventy years. We focus on healing of the meniscus, a tissue essential to knee function with limited innate repair potential, which has been largely unexplored in the context of electrical stimulation. Here we demonstrate for the first time that electrical stimulation enhances meniscus cell migration and integrative tissue repair. We optimize pulsatile direct current electrical stimulation parameters on cells at the micro-scale, and apply these to healing of full-thickness defects in explants at the macro-scale. We report increased expression of the adenosine A2b receptor in meniscus cells after stimulation at the micro- and macro-scale, and propose a role for A2bR in meniscus electrotransduction. Taken together, these findings advance our understanding of the effects of electrical signals and their mechanisms of action, and contribute to developing electrotherapeutic strategies for meniscus repair.

  1. Interindividual variation with respect to DNA repair in human cells

    SciTech Connect

    Leonard, R.C.; Leonard, J.C.; Bender, M.A.; Wieland, J.; Setlow, R.B.

    1989-01-01

    Ecogenetics is the study of genetically determined differences among individuals in their susceptibility to the actions of physical, chemical, and biological agents in the environment. An individual's most basic level of response to these environmental agents may be the ability to repair physical and chemical damage to DNA. We have been engaged in a survey of DNA-repair measurements in a healthy working population in order to determine the extent of the population variability in these endpoints and to assess the value of these screening protocols in identifying individuals who are at the extremes of the distribution. In addition, we are measuring intraindividual variation over time, as well as the correlations between measurements of different repair systems. The endpoints that we have chosen to use are cytogenetic responses (SCE's and micronucleus formation) and DNA excision repair (unscheduled DNA synthesis and removal of O{sup 6} guanine methylation) in human peripheral lymphocytes exposed to 254 nm ultraviolet light, x-rays, the bifunctional alkylating agent mitomycin C, or the monofunctional alkylating agent N-methyl-N-nitro-nitrosoguanidine (MNNG). These four test mutagens produce spectra of DNA lesions eliciting different types of DNA repair. 3 refs., 1 tab.

  2. Harnessing the immunomodulatory and tissue repair properties of mesenchymal stem cells to restore β cell function

    PubMed Central

    Davis, Nicolynn E; Hamilton, Diana; Fontaine, Magali J

    2013-01-01

    Islet cell transplantation has therapeutic potential to cure type 1 diabetes (T1D), which is characterized by autoimmune-mediated destruction of insulin-producing β cells. However, current success rates are limited by long-term decline in islet graft function resulting partially from poor revascularization and immune destruction. MSCs have the potential to enhance islet transplantation and prevent disease progression by a multifaceted approach. MSCs have been shown to be effective at inhibiting inflammatory-mediated immune responses and at promoting tissue regeneration. The immunomodulatory and tissue repairing properties of MSCs may benefit β cell regeneration in the context of T1D. This review will elucidate how MSCs can minimize β cell damage by providing survival signals and simultaneously modulate the immune response by inhibiting activation and proliferation of several immune cell types. In addition, MSCs can enhance islet graft revascularization, maintaining long-term β cell viability and function. PMID:22869154

  3. Hematopoietic Stem Cell Expansion and Gene Therapy

    PubMed Central

    Watts, Korashon Lynn; Adair, Jennifer; Kiem, Hans-Peter

    2012-01-01

    Hematopoietic stem cell (HSC) gene therapy remains a highly attractive treatment option for many disorders including hematologic conditions, immunodeficiencies including HIV/AIDS, and other genetic disorders like lysosomal storage diseases, among others. In this review, we discuss the successes, side effects, and limitations of current gene therapy protocols. In addition, we describe the opportunities presented by implementing ex vivo expansion of gene-modified HSCs, as well as summarize the most promising ex vivo expansion techniques currently available. We conclude by discussing how some of the current limitations of HSC gene therapy could be overcome by combining novel HSC expansion strategies with gene therapy. PMID:21999373

  4. [Magnetic nanoparticles as tools for cell therapy].

    PubMed

    Wilhelm, Claire; Gazeau, Florence

    2012-01-01

    Labelling living cells with magnetic nanoparticles creates opportunities for numerous biomedical applications such as Magnetic Resonance Imaging (MRI) cell tracking, cell manipulation, cell patterning for tissue engineering and magnetically-assisted cell delivery. The unique advantage of magnetic-based methods is to activate or monitor cell behavior by a remote stimulus, the magnetic field. Cell labelling methods using superparamagnetic nanoparticles have been widely developed, showing no adverse effect on cell proliferation and functionalities while conferring magnetic properties to various cell types. This paper first describes how cells can become responsive to magnetic field by safely internalizing magnetic nanoparticles. We next show how magnetic cells can be detected by MRI, giving the opportunity for non-invasive in vivo monitoring of cell migration. We exemplify the fact that MRI cell tracking has become a method of choice to follow the fate of administrated cells in cell therapy assay, whether the cells are grafted locally or administrated in the circulation. Finally we give different examples of magnetic manipulation of cells and their applications to regenerative medicine. Magnetic cell manipulation are forecasted to be more and more developed, in order to improve tissue engineering technique and assist cell-based therapies. Owing to the clinical approval of iron-oxide nanoparticles as MRI contrast agent, there is no major obstacle in the translation to human clinics of the magnetic methods summarized in this paper.

  5. Gene and cell therapy for children — New medicines, new challenges?☆

    PubMed Central

    Buckland, Karen F.; Bobby Gaspar, H.

    2014-01-01

    The range of possible gene and cell therapy applications is expanding at an extremely rapid rate and advanced therapy medicinal products (ATMPs) are currently the hottest topic in novel medicines, particularly for inherited diseases. Paediatric patients stand to gain enormously from these novel therapies as it now seems plausible to develop a gene or cell therapy for a vast number of inherited diseases. There are a wide variety of potential gene and cell therapies in various stages of development. Patients who received first gene therapy treatments for primary immune deficiencies (PIDs) are reaching 10 and 15 years post-treatment, with robust and sustained immune recovery. Cell therapy clinical trials are underway for a variety of tissues including corneal, retinal and muscle repair and islet cell transplantation. Various cell therapy approaches are also being trialled to enhance the safety of bone marrow transplants, which should improve survival rates in childhood cancers and PIDs. Progress in genetic engineering of lymphocyte populations to target and kill cancerous cells is also described. If successful these ATMPs may enhance or replace the existing chemo-ablative therapy for several paediatric cancers. Emerging applications of gene therapy now include skin and neurological disorders such as epidermolysis bullosa, epilepsy and leukodystrophy. Gene therapy trials for haemophilia, muscular dystrophy and a range of metabolic disorders are underway. There is a vast array of potential advanced therapy medicinal products (ATMPs), and these are likely to be more cost effective than existing medicines. However, the first clinical trials have not been without setbacks and some of the key adverse events are discussed. Furthermore, the arrival of this novel class of therapies brings many new challenges for the healthcare industry. We present a summary of the key non-clinical factors required for successful delivery of these potential treatments. Technological advances

  6. Gene and cell therapy for children--new medicines, new challenges?

    PubMed

    Buckland, Karen F; Bobby Gaspar, H

    2014-06-01

    The range of possible gene and cell therapy applications is expanding at an extremely rapid rate and advanced therapy medicinal products (ATMPs) are currently the hottest topic in novel medicines, particularly for inherited diseases. Paediatric patients stand to gain enormously from these novel therapies as it now seems plausible to develop a gene or cell therapy for a vast number of inherited diseases. There are a wide variety of potential gene and cell therapies in various stages of development. Patients who received first gene therapy treatments for primary immune deficiencies (PIDs) are reaching 10 and 15 years post-treatment, with robust and sustained immune recovery. Cell therapy clinical trials are underway for a variety of tissues including corneal, retinal and muscle repair and islet cell transplantation. Various cell therapy approaches are also being trialled to enhance the safety of bone marrow transplants, which should improve survival rates in childhood cancers and PIDs. Progress in genetic engineering of lymphocyte populations to target and kill cancerous cells is also described. If successful these ATMPs may enhance or replace the existing chemo-ablative therapy for several paediatric cancers. Emerging applications of gene therapy now include skin and neurological disorders such as epidermolysis bullosa, epilepsy and leukodystrophy. Gene therapy trials for haemophilia, muscular dystrophy and a range of metabolic disorders are underway. There is a vast array of potential advanced therapy medicinal products (ATMPs), and these are likely to be more cost effective than existing medicines. However, the first clinical trials have not been without setbacks and some of the key adverse events are discussed. Furthermore, the arrival of this novel class of therapies brings many new challenges for the healthcare industry. We present a summary of the key non-clinical factors required for successful delivery of these potential treatments. Technological advances

  7. Essential Roles of Dopamine and Serotonin in Tooth Repair: Functional Interplay Between Odontogenic Stem Cells and Platelets.

    PubMed

    Baudry, Anne; Alleaume-Butaux, Aurélie; Dimitrova-Nakov, Sasha; Goldberg, Michel; Schneider, Benoît; Launay, Jean-Marie; Kellermann, Odile

    2015-08-01

    Characterizing stem cell intrinsic functions is an ongoing challenge for cell therapies. Here, we report that two independent A4 and H8 stem cell lines isolated from mouse molar pulp display the overall functions of bioaminergic cells. Both clones produce neurotrophins and synthesize, catabolize, store, and transport serotonin (5-hydroxytryptamine [5-HT]) and dopamine (DA). They express 5-HT1D,2B,7 and D1,3 autoreceptors, which render pulpal stem cells competent to respond to circulating 5-HT and DA. We show that injury-activated platelets are the source of systemic 5-HT and DA necessary for dental repair since natural dentin reparation is impaired in two rat models with monoamine storage-deficient blood platelets. Moreover, selective inhibition of either D1, D3, 5-HT2B, or 5-HT7 receptor within the pulp of wild-type rat molars after lesion alters the reparative process. Altogether our data argue that 5-HT and DA coreleased by pulp injury-activated platelets are critical for stem cell-mediated dental repair through 5-HT and DA receptor signalings.

  8. Novel Cell and Gene Therapies for HIV

    PubMed Central

    Hoxie, James A.; June, Carl H.

    2012-01-01

    Highly active antiretroviral therapy dramatically improves survival in HIV-infected patients. However, persistence of HIV in reservoirs has necessitated lifelong treatment that can be complicated by cumulative toxicities, incomplete immune restoration, and the emergence of drug-resistant escape mutants. Cell and gene therapies offer the promise of preventing progressive HIV infection by interfering with HIV replication in the absence of chronic antiviral therapy. Individuals homozygous for a deletion in the CCR5 gene (CCR5Δ32) are largely resistant to infection from R5-topic HIV-1 strains, which are most commonly transmitted. A recent report that an HIV-infected patient with relapsed acute myelogenous leukemia was effectively cured from HIV infection after transplantation of hematopoietic stem/progenitor cells (HSC) from a CCR5Δ32 homozygous donor has generated renewed interest in developing treatment strategies that target viral reservoirs and generate HIV resistance in a patient’s own cells. Although the development of cell-based and gene transfer therapies has been slow, progress in a number of areas is evident. Advances in the fields of gene-targeting strategies, T-cell-based approaches, and HSCs have been encouraging, and a series of ongoing and planned trials to establish proof of concept for strategies that could lead to successful cell and gene therapies for HIV are under way. The eventual goal of these studies is to eliminate latent viral reservoirs and the need for lifelong antiretroviral therapy. PMID:23028130

  9. Enhancement of DNA repair capacity of mammalian cells by carcinogen treatment

    SciTech Connect

    Protic, M.; Roilides, E.; Levine, A.S.; Dixon, K.

    1988-07-01

    To determine whether DNA excision repair is enhanced in mammalian cells in response to DNA damage, as it is in bacteria as part of the SOS response, we used an expression vector-host cell reactivation assay to measure cellular DNA repair capacity. When UV-damaged chloramphenicol acetyltransferase (CAT) vector DNA was introduced into monkey cells (CV-1), the level of CAT activity was inversely related to the UV fluence due to inhibition of CAT gene expression by UV photoproducts. When CV-1 cells were treated with either UV radiation or mitomycin C, 24-48 h before transfection, CAT expression from the UV-irradiated plasmid was increased. This increase also occurred in a line of normal human cells, but not in repair-deficient human xeroderma pigmentosum cells. We confirmed that this increase in CAT expression was due to repair, and not to production of damage-free templates by recombination; the frequency of generation of supF+ recombinants after transfection with UV-irradiated pZ189 vectors carrying different point mutations in the supF gene did not significantly increase in carcinogen-treated CV-1 cells. From these results we conclude that carcinogen treatment enhances the excision-repair capacity of normal mammalian cells.

  10. Plastic fantastic: Schwann cells and repair of the peripheral nervous system.

    PubMed

    Kim, Haesun A; Mindos, Thomas; Parkinson, David B

    2013-08-01

    Repair in the peripheral nervous system (PNS) depends upon the plasticity of the myelinating cells, Schwann cells, and their ability to dedifferentiate, direct axonal regrowth, remyelinate, and allow functional recovery. The ability of such an exquisitely specialized myelinating cell to revert to an immature dedifferentiated cell that can direct repair is remarkable, making Schwann cells one of the very few regenerative cell types in our bodies. However, the idea that the PNS always repairs after injury, in contrast to the central nervous system, is not true. Repair in patients after nerve trauma can be incredibly variable, depending on the site and type of injury, and only a relatively small number of axons may fully regrow and reinnervate their targets. Recent research has shown that it is an active process that drives Schwann cells back to an immature state after injury and that this requires activity of the p38 and extracellular-regulated kinase 1/2 mitogen-activated protein kinases, as well as the transcription factor cJun. Analysis of the events after peripheral nerve transection has shown how signaling from nerve fibroblasts forms Schwann cells into cords in the newly generated nerve bridge, via Sox2 induction, to allow the regenerating axons to cross the gap. Understanding these pathways and identifying additional mechanisms involved in these processes raises the possibility of both boosting repair after PNS trauma and even, possibly, blocking the inappropriate demyelination seen in some disorders of the peripheral nervous system.

  11. In Vitro Expansion of Bone Marrow Derived Mesenchymal Stem Cells Alters DNA Double Strand Break Repair of Etoposide Induced DNA Damage

    PubMed Central

    Hare, Ian; Gencheva, Marieta; Evans, Rebecca; Fortney, James; Piktel, Debbie; Vos, Jeffrey A.; Howell, David; Gibson, Laura F.

    2016-01-01

    Mesenchymal stem cells (MSCs) are of interest for use in diverse cellular therapies. Ex vivo expansion of MSCs intended for transplantation must result in generation of cells that maintain fidelity of critical functions. Previous investigations have identified genetic and phenotypic alterations of MSCs with in vitro passage, but little is known regarding how culturing influences the ability of MSCs to repair double strand DNA breaks (DSBs), the most severe of DNA lesions. To investigate the response to DSB stress with passage in vitro, primary human MSCs were exposed to etoposide (VP16) at various passages with subsequent evaluation of cellular damage responses and DNA repair. Passage number did not affect susceptibility to VP16 or the incidence and repair kinetics of DSBs. Nonhomologous end joining (NHEJ) transcripts showed little alteration with VP16 exposure or passage; however, homologous recombination (HR) transcripts were reduced following VP16 exposure with this decrease amplified as MSCs were passaged in vitro. Functional evaluations of NHEJ and HR showed that MSCs were unable to activate NHEJ repair following VP16 stress in cells after successive passage. These results indicate that ex vivo expansion of MSCs alters their ability to perform DSB repair, a necessary function for cells intended for transplantation. PMID:26880992

  12. In Vitro Expansion of Bone Marrow Derived Mesenchymal Stem Cells Alters DNA Double Strand Break Repair of Etoposide Induced DNA Damage.

    PubMed

    Hare, Ian; Gencheva, Marieta; Evans, Rebecca; Fortney, James; Piktel, Debbie; Vos, Jeffrey A; Howell, David; Gibson, Laura F

    2016-01-01

    Mesenchymal stem cells (MSCs) are of interest for use in diverse cellular therapies. Ex vivo expansion of MSCs intended for transplantation must result in generation of cells that maintain fidelity of critical functions. Previous investigations have identified genetic and phenotypic alterations of MSCs with in vitro passage, but little is known regarding how culturing influences the ability of MSCs to repair double strand DNA breaks (DSBs), the most severe of DNA lesions. To investigate the response to DSB stress with passage in vitro, primary human MSCs were exposed to etoposide (VP16) at various passages with subsequent evaluation of cellular damage responses and DNA repair. Passage number did not affect susceptibility to VP16 or the incidence and repair kinetics of DSBs. Nonhomologous end joining (NHEJ) transcripts showed little alteration with VP16 exposure or passage; however, homologous recombination (HR) transcripts were reduced following VP16 exposure with this decrease amplified as MSCs were passaged in vitro. Functional evaluations of NHEJ and HR showed that MSCs were unable to activate NHEJ repair following VP16 stress in cells after successive passage. These results indicate that ex vivo expansion of MSCs alters their ability to perform DSB repair, a necessary function for cells intended for transplantation.

  13. Intrinsic repair protects cells from pore-forming toxins by microvesicle shedding.

    PubMed

    Romero, Matthew; Keyel, Michelle; Shi, Guilan; Bhattacharjee, Pushpak; Roth, Robyn; Heuser, John E; Keyel, Peter A

    2017-02-10

    Pore-forming toxins (PFTs) are used by both the immune system and by pathogens to disrupt cell membranes. Cells attempt to repair this disruption in various ways, but the exact mechanism(s) that cells use are not fully understood, nor agreed upon. Current models for membrane repair include (1) patch formation (e.g., fusion of internal vesicles with plasma membrane defects), (2) endocytosis of the pores, and (3) shedding of the pores by blebbing from the cell membrane. In this study, we sought to determine the specific mechanism(s) that cells use to resist three different cholesterol-dependent PFTs: Streptolysin O, Perfringolysin O, and Intermedilysin. We found that all three toxins were shed from cells by blebbing from the cell membrane on extracellular microvesicles (MVs). Unique among the cells studied, we found that macrophages were 10 times more resistant to the toxins, yet they shed significantly smaller vesicles than the other cells. To examine the mechanism of shedding, we tested whether toxins with engineered defects in pore formation or oligomerization were shed. We found that oligomerization was necessary and sufficient for membrane shedding, suggesting that calcium influx and patch formation were not required for shedding. However, pore formation enhanced shedding, suggesting that calcium influx and patch formation enhance repair. In contrast, monomeric toxins were endocytosed. These data indicate that cells use two interrelated mechanisms of membrane repair: lipid-dependent MV shedding, which we term 'intrinsic repair', and patch formation by intracellular organelles. Endocytosis may act after membrane repair is complete by removing inactivated and monomeric toxins from the cell surface.Cell Death and Differentiation advance online publication, 10 February 2017; doi:10.1038/cdd.2017.11.

  14. Improving Cell Engraftment in Cardiac Stem Cell Therapy

    PubMed Central

    Xie, Xiaoyun

    2016-01-01

    Myocardial infarction (MI) affects millions of people worldwide. MI causes massive cardiac cell death and heart function decrease. However, heart tissue cannot effectively regenerate by itself. While stem cell therapy has been considered an effective approach for regeneration, the efficacy of cardiac stem cell therapy remains low due to inferior cell engraftment in the infarcted region. This is mainly a result of low cell retention in the tissue and poor cell survival under ischemic, immune rejection and inflammatory conditions. Various approaches have been explored to improve cell engraftment: increase of cell retention using biomaterials as cell carriers; augmentation of cell survival under ischemic conditions by preconditioning cells, genetic modification of cells, and controlled release of growth factors and oxygen; and enhancement of cell survival by protecting cells from excessive inflammation and immune surveillance. In this paper, we review current progress, advantages, disadvantages, and potential solutions of these approaches. PMID:26783405

  15. Mitochondria mediate cell membrane repair and contribute to Duchenne muscular dystrophy

    PubMed Central

    Vila, Maria C; Rayavarapu, Sree; Hogarth, Marshall W; Van der Meulen, Jack H; Horn, Adam; Defour, Aurelia; Takeda, Shin'ichi; Brown, Kristy J; Hathout, Yetrib; Nagaraju, Kanneboyina; Jaiswal, Jyoti K

    2017-01-01

    Dystrophin deficiency is the genetic basis for Duchenne muscular dystrophy (DMD), but the cellular basis of progressive myofiber death in DMD is not fully understood. Using two dystrophin-deficient mdx mouse models, we find that the mitochondrial dysfunction is among the earliest cellular deficits of mdx muscles. Mitochondria in dystrophic myofibers also respond poorly to sarcolemmal injury. These mitochondrial deficits reduce the ability of dystrophic muscle cell membranes to repair and are associated with a compensatory increase in dysferlin-mediated membrane repair proteins. Dysferlin deficit in mdx mice further compromises myofiber cell membrane repair and enhances the muscle pathology at an asymptomatic age for dysferlin-deficient mice. Restoring partial dystrophin expression by exon skipping improves mitochondrial function and offers potential to improve myofiber repair. These findings identify that mitochondrial deficit in muscular dystrophy compromises the repair of injured myofibers and show that this repair mechanism is distinct from and complimentary to the dysferlin-mediated repair of injured myofibers. PMID:27834955

  16. Pluripotent Stem Cells and Gene Therapy

    PubMed Central

    Simara, Pavel; Motl, Jason A.; Kaufman, Dan S.

    2013-01-01

    Human pluripotent stem cells represent an accessible cell source for novel cell-based clinical research and therapies. With the realization of induced pluripotent stem cells (iPSCs), it is possible to produce almost any desired cell type from any patient's cells. Current developments in gene modification methods have opened the possibility for creating genetically corrected human iPSCs for certain genetic diseases that could be used later in autologous transplantation. Promising preclinical studies have demonstrated correction of disease-causing mutations in a number of hematological, neuronal and muscular disorders. This review aims to summarize these recent advances with a focus on iPSC generation techniques, as well as gene modification methods. We will then further discuss some of the main obstacles remaining to be overcome before successful application of human pluripotent stem cell-based therapy arrives in the clinic and what the future of stem cell research may look like. PMID:23353080

  17. Translational research of adult stem cell therapy.

    PubMed

    Suzuki, Gen

    2015-11-26

    Congestive heart failure (CHF) secondary to chronic coronary artery disease is a major cause of morbidity and mortality world-wide. Its prevalence is increasing despite advances in medical and device therapies. Cell based therapies generating new cardiomyocytes and vessels have emerged as a promising treatment to reverse functional deterioration and prevent the progression to CHF. Functional efficacy of progenitor cells isolated from the bone marrow and the heart have been evaluated in preclinical large animal models. Furthermore, several clinical trials using autologous and allogeneic stem cells and progenitor cells have demonstrated their safety in humans yet their clinical relevance is inconclusive. This review will discuss the clinical therapeutic applications of three specific adult stem cells that have shown particularly promising regenerative effects in preclinical studies, bone marrow derived mesenchymal stem cell, heart derived cardiosphere-derived cell and cardiac stem cell. We will also discuss future therapeutic approaches.

  18. Inactivation of ultraviolet repair in normal and xeroderma pigmentosum cells by methyl methanesulfonate

    SciTech Connect

    Cleaver, J.E.

    1982-03-01

    Excision repair of ultraviolet damage in the DNA of normal and xeroderma pigmentosum (Groups C, D, and variant) cells was inactivated by exposure of cells to methyl methanesulfonate immediately before irradiation independent of the presence of 0 to 10% fetal calf serum. The inactivation could be represented by a semilog relationship between the amount of repair and methyl methanesulfonate concentration up to approximately 5 mM. The inactivation can be considered to occur as the result of alkylation of a large (about 10(6) daltons) repair enzyme complex, and the dose required to reduce repair to 37% for most cells types was between 4 and 7 mM. No consistent, large difference in sensitivity to methyl methanesulfonate was found in any xeroderma pigmentosum complementation group compared to normal cells, implying that reduced repair in these groups may be caused by small inherited changes in the amino acid composition (i.e., point mutations or small deletions) rather than by losses of major components of the repair enzyme complex.

  19. Impaired repair of ionizing radiation-induced DNA damage in Cockayne syndrome cells.

    PubMed

    Cramers, Patricia; Verhoeven, Esther E; Filon, A Ronald; Rockx, Davy A P; Santos, Susy J; van der Leer, Anneke A; Kleinjans, Jos C S; van Zeeland, Albert A; Mullenders, Leon H F

    2011-04-01

    Cockayne syndrome (CS) cells are defective in transcription-coupled repair (TCR) and sensitive to oxidizing agents, including ionizing radiation. We examined the hypothesis that TCR plays a role in ionizing radiation-induced oxidative DNA damage repair or alternatively that CS plays a role in transcription elongation after irradiation. Irradiation with doses up to 100 Gy did not inhibit RNA polymerase II-dependent transcription in normal and CS-B fibroblasts. In contrast, RNA polymerase I-dependent transcription was severely inhibited at 5 Gy in normal cells, indicating different mechanisms of transcription response to X rays. The frequency of radiation-induced base damage was 2 × 10(-7) lesions/base/Gy, implying that 150 Gy is required to induce one lesion/30-kb transcription unit; no TCR of X-ray-induced base damage in the p53 gene was observed. Therefore, it is highly unlikely that defective TCR underlies the sensitivity of CS to ionizing radiation. Overall genome repair levels of radiation-induced DNA damage measured by repair replication were significantly reduced in CS-A and CS-B cells. Taken together, the results do not provide evidence for a key role of TCR in repair of radiation-induced oxidative damages in human cells; rather, impaired repair of oxidative lesions throughout the genome may contribute to the CS phenotype.

  20. Human fetal chromaffin cells: a potential tool for cell pain therapy.

    PubMed

    Jozan, Suzanne; Aziza, Jacqueline; Châtelin, Sophie; Evra, Corinne; Courtade-Saïdi, Monique; Parant, Olivier; Sol, Jean Christophe; Zhou, Huafang; Lazorthes, Yves

    2007-06-01

    Transplantation of adrenal medulla cells has been proposed in the treatment of various conditions. Indeed, these cells possess a bipotentiality: neural and neuroendocrine, which could be exploited for brain repair or pain therapy. In a previous study, we characterized these human cells in vitro over 7-10 gestational weeks (GW) [Zhou, H., Aziza, J., Sol, J.C., Courtade-Saidi, M., Chatelin, S., Evra, C., Parant, O., Lazorthes, Y., and Jozan, S., 2006. Cell therapy of pain: Characterization of human fetal chromaffin cells at early adrenal medulla development. Exp. Neurol. 198, 370-381]. We report here our results on the extension to 23 GW. This developmental period can be split into three stages. During the first stage (7-10 GW), we observed in situ that extra-adrenal surrounding cells display the same morphology and phenotype as the intra-adrenal chromaffin cells. We also found that the intra-adrenal chromaffin cells could be committed in vitro towards an adrenergic phenotype using differentiating agents. During the second stage (11 to 15-16 GW), two types of cells (Type 1 and Type 2 cells) were identified morphologically both inside and outside the gland. Interestingly, we noted that the Type 2 cells stem from the Type 1 cells. However, during this developmental period only the intra-adrenal Type 2 cells will evolve towards an adrenergic phenotype. In the third stage (17-23 GW), we observed the ultimate location of the medulla gland. Both the in situ results and the in vitro experiments indicate that particular procedures need to be implemented prior transplantation of chromaffin cells. First, in order to obtain a large number of immature chromaffin cells, they must be isolated from the intra and extra-adrenal gland and should then be committed towards an adrenergic phenotype in vitro for subsequent use in pain therapy. This strategy is under investigation in our laboratory.

  1. Cell-based therapy in ischemic stroke

    PubMed Central

    2009-01-01

    Cell-based therapy for stroke represents a third wave of therapeutics for stroke and one focused on restorative processes with a longer time window of opportunity than neuroprotective therapies. An early time window, within the first week after stroke, is an opportunity for intravenously delivered bone-marrow and perinatally-derived cells that can home to areas of tissue injury and target brain remodeling. Allogeneic cells will likely be the most scalable and commercially viable product. Later time windows, months after stroke, may be opportunities for intracerebral transplantation of neuronally-differentiated cell types. An integrated approach of cell-based therapy with early phase clinical trials and continued pre-clinical work with focus on mechanisms of action is needed. PMID:18671663

  2. Statin therapy and the expression of genes that regulate calcium homeostasis and membrane repair in skeletal muscle.

    PubMed

    Draeger, Annette; Sanchez-Freire, Verónica; Monastyrskaya, Katia; Hoppeler, Hans; Mueller, Matthias; Breil, Fabio; Mohaupt, Markus G; Babiychuk, Eduard B

    2010-07-01

    In skeletal muscle of patients with clinically diagnosed statin-associated myopathy, discrete signs of structural damage predominantly localize to the T-tubular region and are suggestive of a calcium leak. The impact of statins on skeletal muscle of non-myopathic patients is not known. We analyzed the expression of selected genes implicated in the molecular regulation of calcium and membrane repair, in lipid homeostasis, myocyte remodeling and mitochondrial function. Microscopic and gene expression analyses were performed using validated TaqMan custom arrays on skeletal muscle biopsies of 72 age-matched subjects who were receiving statin therapy (n = 38), who had discontinued therapy due to statin-associated myopathy (n = 14), and who had never undergone statin treatment (n = 20). In skeletal muscle, obtained from statin-treated, non-myopathic patients, statins caused extensive changes in the expression of genes of the calcium regulatory and the membrane repair machinery, whereas the expression of genes responsible for mitochondrial function or myocyte remodeling was unaffected. Discontinuation of treatment due to myopathic symptoms led to a normalization of gene expression levels, the genes encoding the ryanodine receptor 3, calpain 3, and dystrophin being the most notable exceptions. Hence, even in clinically asymptomatic (non-myopathic) patients, statin therapy leads to an upregulation in the expression of genes that are concerned with skeletal muscle regulation and membrane repair.

  3. Matrix immobilization enhances the tissue repair activity of growth factor gene therapy vectors.

    PubMed

    Doukas, J; Chandler, L A; Gonzalez, A M; Gu, D; Hoganson, D K; Ma, C; Nguyen, T; Printz, M A; Nesbit, M; Herlyn, M; Crombleholme, T M; Aukerman, S L; Sosnowski, B A; Pierce, G F

    2001-05-01

    Although growth factor proteins display potent tissue repair activities, difficulty in sustaining localized therapeutic concentrations limits their therapeutic activity. We reasoned that enhanced histogenesis might be achieved by combining growth factor genes with biocompatible matrices capable of immobilizing vectors at delivery sites. When delivered to subcutaneously implanted sponges, a platelet-derived growth factor B-encoding adenovirus (AdPDGF-B) formulated in a collagen matrix enhanced granulation tissue deposition 3- to 4-fold (p < or = 0.0002), whereas vectors encoding fibroblast growth factor 2 or vascular endothelial growth factor promoted primarily angiogenic responses. By day 8 posttreatment of ischemic excisional wounds, collagen-formulated AdPDGF-B enhanced granulation tissue and epithelial areas up to 13- and 6-fold (p < 0.009), respectively, and wound closure up to 2-fold (p < 0.05). At longer times, complete healing without excessive scar formation was achieved. Collagen matrices were shown to retain both vector and transgene products within delivery sites, enabling the transduction and stimulation of infiltrating repair cells. Quantitative PCR and RT-PCR demonstrated both vector DNA and transgene mRNA within wound beds as late as 28 days posttreatment. By contrast, aqueous formulations allowed vector seepage from application sites, leading to PDGF-induced hyperplasia in surrounding tissues but not wound beds. Finally, repeated applications of PDGF-BB protein were required for neotissue induction approaching equivalence to a single application of collagen-immobilized AdPDGF-B, confirming the utility of this gene transfer approach. Overall, these studies demonstrate that immobilizing matrices enable the controlled delivery and activity of tissue promoting genes for the effective regeneration of injured tissues.

  4. Genetic characterization of cells of homocystinuria patients with disrupted DNA repair system

    SciTech Connect

    Sinel'shchikova, T.A.; L'vova, G.N.; Shoniya, N.N.; Zasukhina, G.D.

    1986-08-01

    Fibroblasts obtained from biopsy material and lymphocytes of patients with homocystinuria were investigated for repair activity according to the following criteria: rejoined DNA breaks, induced by 4-nitroquinoline-1-oxide and ..gamma..-radiation; indices of reactivation and induced mutagenesis of smallpox vaccine virus treated with these mutagens. In lymphocytes a defect of DNA repair was observed according to all criteria investigated. During passage of fibroblast cultures, inhibition of repair activity of cells was preserved according to ..gamma..-type. Increase in the number of spontaneous and ..gamma..-induced mutations of virus was noted according to degree of passage of fibroblasts.

  5. Repair and replication of DNA in hereditary (bilateral) retinoblastoma cells after X-irradiation

    SciTech Connect

    Cleaver, J.E.; Char, D.; Charles, W.C.; Rand, N.

    1982-04-01

    Fibroblasts from patients with hereditary retinoblastoma reportedly exhibit increased sensitivity to killing by X-rays. Although some human syndromes with similar or greater hypersensitivity to DNA-damaging agents (e.g., X-rays, ultraviolet light, and chemical carcinogens), such as xeroderma pigmentosum, are deficient in DNA repair, most do not have such clearly demonstrable defects in repair. Retinoblastoma cells appear to be normal in repairing single-strand breaks and performing repair replication after X-irradiation and also in synthesizing poly(adenosine diphosphoribose). Semiconservative DNA replication in these cells, however, is slightly more resistant than normal after X-irradiation, suggesting that continued replication of damaged parental DNA could contribute to the pathogenesis of the disease. This effect is small, however, and may be a consequence rather than a cause of the fundamental enzymatic abnormality in retinoblastoma that causes the tumorigenesis.

  6. Cell transcriptional state alters genomic patterns of DNA double-strand break repair in human astrocytes.

    PubMed

    Yong, Raymund L; Yang, Chunzhang; Lu, Jie; Wang, Huaien; Schlaff, Cody D; Tandle, Anita; Graves, Christian A; Elkahloun, Abdel G; Chen, Xiaoyuan; Zhuang, Zhengping; Lonser, Russell R

    2014-12-17

    The misrepair of DNA double-strand breaks in close spatial proximity within the nucleus can result in chromosomal rearrangements that are important in the pathogenesis of haematopoietic and solid malignancies. It is unknown why certain epigenetic states, such as those found in stem or progenitor cells, appear to facilitate neoplastic transformation. Here we show that altering the transcriptional state of human astrocytes alters patterns of DNA damage repair from ionizing radiation at a gene locus-specific and genome-wide level. Astrocytes induced into a reactive state exhibit increased DNA repair, compared with non-reactive cells, in actively transcribed chromatin after irradiation. In mapping these repair sites, we identify misrepair events and repair hotspots that are unique to each state. The precise characterization of genomic regions susceptible to mutation in specific transcriptional states provides new opportunities for addressing clonal evolution in solid cancers, in particular those where double-strand break induction is a cornerstone of clinical intervention.

  7. Cell therapy in bone healing disorders

    PubMed Central

    Jäger, Marcus; Hernigou, Philippe; Zilkens, Christoph; Herten, Monika; Li, Xinning; Fischer, Johannes; Krauspe, Rüdiger

    2010-01-01

    In addition to osteosynthetic stabilizing techniques and autologous bone transplantations, so-called orthobiologics play an increasing role in the treatment of bone healing disorders. Besides the use of various growth factors, more and more new data suggest that cell-based therapies promote local bone regeneration. For ethical and biological reasons, clinical application of progenitor cells on the musculoskeletal system is limited to autologous, postpartum stem cells. Intraoperative one-step treatment with autologous progenitor cells, in particular, delivered promising results in preliminary clinical studies. This article provides an overview of the rationale for, and characteristics of the clinical application of cell-based therapy to treat osseous defects based on a review of existing literature and our own experience with more than 100 patients. Most clinical trials report successful bone regeneration after the application of mixed cell populations from bone marrow. The autologous application of human bone marrow cells which are not expanded ex vivo has medico-legal advantages. However, there is a lack of prospective randomized studies including controls for cell therapy for bone defects. Autologous bone marrow cell therapy seems to be a promising treatment option which may reduce the amount of bone grafting in future. PMID:21808710

  8. Stem cell delivery in tissue-specific hydrogel enabled meniscal repair in an orthotopic rat model.

    PubMed

    Yuan, Xiaoning; Wei, Yiyong; Villasante, Aránzazu; Ng, Johnathan J D; Arkonac, Derya E; Chao, Pen-Hsiu Grace; Vunjak-Novakovic, Gordana

    2017-04-04

    Interest in non-invasive injectable therapies has rapidly risen due to their excellent safety profile and ease of use in clinical settings. Injectable hydrogels can be derived from the extracellular matrix (ECM) of specific tissues to provide a biomimetic environment for cell delivery and enable seamless regeneration of tissue defects. We investigated the in situ delivery of human mesenchymal stem cells (hMSCs) in decellularized meniscus ECM hydrogel to a meniscal defect in a nude rat model. First, decellularized meniscus ECM hydrogel retained tissue-specific proteoglycans and collagens, and significantly upregulated expression of fibrochondrogenic markers by hMSCs versus collagen hydrogel alone in vitro. The meniscus ECM hydrogel in turn supported delivery of hMSCs for integrative repair of a full-thickness defect model in meniscal explants after in vitro culture and in vivo subcutaneous implantation. When applied to an orthotopic model of meniscal injury in nude rat, hMSCs in meniscus ECM hydrogel were retained out to eight weeks post-injection, contributing to tissue regeneration and protection from joint space narrowing, pathologic mineralization, and osteoarthritis development, as evidenced by macroscopic and microscopic image analysis. Based on these findings, we propose the use of tissue-specific meniscus ECM-derived hydrogel for the delivery of therapeutic hMSCs to treat meniscal injury.

  9. Triple-helix formation induces recombination in mammalian cells via a nucleotide excision repair-dependent pathway.

    PubMed

    Faruqi, A F; Datta, H J; Carroll, D; Seidman, M M; Glazer, P M

    2000-02-01

    The ability to stimulate recombination in a site-specific manner in mammalian cells may provide a useful tool for gene knockout and a valuable strategy for gene therapy. We previously demonstrated that psoralen adducts targeted by triple-helix-forming oligonucleotides (TFOs) could induce recombination between tandem repeats of a supF reporter gene in a simian virus 40 vector in monkey COS cells. Based on work showing that triple helices, even in the absence of associated psoralen adducts, are able to provoke DNA repair and cause mutations, we asked whether intermolecular triplexes could stimulate recombination. Here, we report that triple-helix formation itself is capable of promoting recombination and that this effect is dependent on a functional nucleotide excision repair (NER) pathway. Transfection of COS cells carrying the dual supF vector with a purine-rich TFO, AG30, designed to bind as a third strand to a region between the two mutant supF genes yielded recombinants at a frequency of 0.37%, fivefold above background, whereas a scrambled sequence control oligomer was ineffective. In human cells deficient in the NER factor XPA, the ability of AG30 to induce recombination was eliminated, but it was restored in a corrected subline expressing the XPA cDNA. In comparison, the ability of triplex-directed psoralen cross-links to induce recombination was only partially reduced in XPA-deficient cells, suggesting that NER is not the only pathway that can metabolize targeted psoralen photoadducts into recombinagenic intermediates. Interestingly, the triplex-induced recombination was unaffected in cells deficient in DNA mismatch repair, challenging our previous model of a heteroduplex intermediate and supporting a model based on end joining. This work demonstrates that oligonucleotide-mediated triplex formation can be recombinagenic, providing the basis for a potential strategy to direct genome modification by using high-affinity DNA binding ligands.

  10. Differential Expression of DNA Double-Strand Break Repair Proteins in Breast Cells

    DTIC Science & Technology

    2001-07-01

    resting breast tissues from 10 different patients express both components of DNA-PK, DNAPKcs and Ku. These tissues also expressed XRCC4, DNA Ligase IV...DNA-PK in human breast tissues by immuno-histochemistry and extended these studies to two other components of the NHEJ repair pathway, XRCC4 and DNA ... ligase IV, as well as three other DNA repair components NBS1, MRE11, and PCNA. In contrast to the original report, 90% of the epithelial cells in normal

  11. Suppression of DNA-dependent protein kinase sensitize cells to radiation without affecting DSB repair.

    PubMed

    Gustafsson, Ann-Sofie; Abramenkovs, Andris; Stenerlöw, Bo

    2014-11-01

    Efficient and correct repair of DNA double-strand break (DSB) is critical for cell survival. Defects in the DNA repair may lead to cell death, genomic instability and development of cancer. The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) is an essential component of the non-homologous end joining (NHEJ) which is the major DSB repair pathway in mammalian cells. In the present study, by using siRNA against DNA-PKcs in four human cell lines, we examined how low levels of DNA-PKcs affected cellular response to ionizing radiation. Decrease of DNA-PKcs levels by 80-95%, induced by siRNA treatment, lead to extreme radiosensitivity, similar to that seen in cells completely lacking DNA-PKcs and low levels of DNA-PKcs promoted cell accumulation in G2/M phase after irradiation and blocked progression of mitosis. Surprisingly, low levels of DNA-PKcs did not affect the repair capacity and the removal of 53BP1 or γ-H2AX foci and rejoining of DSB appeared normal. This was in strong contrast to cells completely lacking DNA-PKcs and cells treated with the DNA-PKcs inhibitor NU7441, in which DSB repair were severely compromised. This suggests that there are different mechanisms by which loss of DNA-PKcs functions can sensitize cells to ionizing radiation. Further, foci of phosphorylated DNA-PKcs (T2609 and S2056) co-localized with DSB and this was independent of the amount of DNA-PKcs but foci of DNA-PKcs was only seen in siRNA-treated cells. Our study emphasizes on the critical role of DNA-PKcs for maintaining survival after radiation exposure which is uncoupled from its essential function in DSB repair. This could have implications for the development of therapeutic strategies aiming to radiosensitize tumors by affecting the DNA-PKcs function.

  12. Dendritic cell therapy for oncology roundtable conference

    PubMed Central

    2011-01-01

    2-3 September 2010, Brussels, Belgium The Dendritic Cell Therapy for Oncology Roundtable Conference was organized by Reliable Cancer Therapies and moderated by Prof. Dr. Steven De Vleeschouwer. The organizer, Reliable Cancer Therapies, is a Swiss non-profit organization that provides information on evidence-based cancer treatments and funding for the development of a selection of promising cancer therapies. In order to be able to give valuable information about dendritic cell (DC) therapy to patients and physicians, the organizing committee felt it necessary to organize this conference to get an up-to-date status of the academic DC therapy field, collect ideas to guide patients towards clinical trials and to induce cross-fertilization for protocol optimization. In total, 31 experts participated to an in-depth discussion about the status and the future development path for dendritic cell vaccines. The conference started with general presentations about cancer immunotherapy, followed by comprehensive overview presentations about the progress in DC vaccine development achieved by each speaker. At the end of the meeting, a thorough general discussion focused on key questions about what is needed to improve DC vaccines. This report does not cover all presentations, but aims to highlight selected points of interest, particularly relating to possible limitations and potential approaches to improvement of DC therapies specifically, and also immunotherapeutic interventions in general terms. PMID:21226916

  13. Alternative Cell Sources to Adult Hepatocytes for Hepatic Cell Therapy.

    PubMed

    Pareja, Eugenia; Gómez-Lechón, María José; Tolosa, Laia

    2017-01-01

    Adult hepatocyte transplantation is limited by scarce availability of suitable donor liver tissue for hepatocyte isolation. New cell-based therapies are being developed to supplement whole-organ liver transplantation, to reduce the waiting-list mortality rate, and to obtain more sustained and significant metabolic correction. Fetal livers and unsuitable neonatal livers for organ transplantation have been proposed as potential useful sources of hepatic cells for cell therapy. However, the major challenge is to use alternative cell sources for transplantation that can be derived from reproducible methods. Different types of stem cells with hepatic differentiation potential are eligible for generating large numbers of functional hepatocytes for liver cell therapy to treat degenerative disorders, inborn hepatic metabolic diseases, and organ failure. Clinical trials are designed to fully establish the safety profile of such therapies and to define target patient groups and standardized protocols.

  14. Immuno-modification of enhancing stem cells targeting for myocardial repair.

    PubMed

    Yu, Jiashing; Wu, Yuan-Kun; Gu, Yiping; Fang, Qizhi; Sievers, Richard; Ding, Chun-Hua; Olgin, Jeffrey E; Lee, Randall J

    2015-07-01

    Despite the controversy in mechanism, rodent and clinical studies have demonstrated beneficial effects of stem/progenitor cell therapy after myocardial infarction (MI). In a rat ischaemic reperfusion MI model, we investigated the effects of immunomodification of CD 34(+) cells on heart function and myocardial conduction. Bispecific antibody (BiAb), consisting of an anti-myosin light chain antibody and anti-CD45 antibody, injected intravenously was used to direct human CD34(+) cells to injured myocardium. Results were compared to echocardiography guided intramyocardial (IM) injection of CD34(+) cells and PBS injected intravenously. Treatment was administered 2 days post MI. Echocardiography was performed at 5 weeks and 3 months which demonstrated LV dilatation prevention and fractional shortening improvement in both the BiAb and IM injection approaches, with BiAb achieving better results. Histological analyses demonstrated a decrease in infarct size and increase in arteriogenesis in both BiAb and IM injection. Electrophysiological properties were studied 5 weeks after treatments by optical mapping. Conduction velocity (CV), action potential duration (APD) and rise time were significantly altered in the MI area. The BiAb treated group demonstrated a more normalized activation pattern of conduction and normalization of CV at shorter pacing cycle lengths. The ventricular tachycardia inducibility was lowest in the BiAb treatment group. Intravenous administration of BiAb offers an effective means of stem cell delivery for myocardial repair post-acute MI. Such non-invasive approach was shown to offer a distinct advantage to more invasive direct IM delivery.

  15. Infrastructure development for human cell therapy translation.

    PubMed

    Dietz, A B; Padley, D J; Gastineau, D A

    2007-09-01

    The common conception of a drug is that of a chemical with defined medicinal effect. However, cells used as drugs remain critical to patient care. Cell therapy's origins began with the realization that complex tissues such as blood can retain function when transplanted to the patient. More complex transplantation followed, culminating with the understanding that transplantation of some tissues such as bone marrow may act medicinally. Administration of cells with an intended therapeutic effect is a hallmark of cellular therapy. While cells have been used as drugs for decades, testing a specific therapeutic effect of cells has begun clinical testing relatively recently. Lessons learned during the establishment of blood banking (including the importance of quality control, process control, sterility, and product tracking) are key components in the assurance of the safety and potency of cell therapy preparations. As more academic medical centers and private companies move toward exploiting the full potential of cells as drugs, needs arise for the development of the infrastructure necessary to support these investigations. Careful consideration of the design of the structure used to manufacture is important in terms of the significant capital outlay involved and the facility's role in achieving regulatory compliance. This development perspective describes the regulatory environment surrounding the infrastructure support for cell therapy and practical aspects for design consideration with particular focus on those activities associated with early clinical trials.

  16. Adiponectinemia controls pro-angiogenic cell therapy.

    PubMed

    Eren, Philippe; Camus, Stéphane; Matrone, Gianfranco; Ebrahimian, Téni G; François, Delphine; Tedgui, Alain; Sébastien Silvestre, Jean; Blanc-Brude, Olivier P

    2009-11-01

    Angiogenic cell therapy with the transplantation of endothelial progenitor cells (EPC) or bone marrow mononuclear cells (BM-MNC) receives considerable attention as an approach to revascularize ischemic tissues. Adiponectin is a circulating hormone produced by the apM1 gene in adipocytes. Adiponectin modulates lipid metabolism and obesity, and it was recently found to promote physiological angiogenesis in response to ischemia. Patients with multiple cardiovascular disease risk factors or myocardial infarction may benefit from progenitor cell therapy, but they display depressed adiponectinemia. We hypothesized that adiponectin stimulation of transplanted cells is critical for their pro-angiogenic function. We aimed to establish whether adiponectinemia in the cell donor or in the cell recipient determines the success of pro-angiogenic cell therapy. In vitro, we found that conditioned media derived from wild-type adipocytes (adipo-CM) or purified adiponectin strongly enhanced BM-MNC survival and proliferation and stimulated EPC differentiation, whereas adipo-CM from apM1-/- adipocytes was one-half less effective. On the other hand, wild-type and apM1-/- BM-MNC displayed similar resistance to apoptosis and proliferation rates. In vivo, wild-type, and apM1-/- BM-MNC induced similar angiogenic reactions in wild-type ischemic hindlimbs. In contrast, wild-type BM-MNC had much diminished effects in apM1-/- ischemic hindlimbs. We concluded that adiponectin enhances BM-MNC survival and proliferation, and adiponectinemia in the cell therapy recipient is essential for the pro-angiogenic benefits of cell therapy. These observations imply that progenitor cell transplantation might only induce angiogenesis in patients with high adiponectinemia.

  17. Advanced cell therapies for articular cartilage regeneration.

    PubMed

    Madeira, Catarina; Santhagunam, Aruna; Salgueiro, João B; Cabral, Joaquim M S

    2015-01-01

    Advanced cell-based therapies are promising approaches for stimulating full regeneration of cartilage lesions. In addition to a few commercially available medicinal products, several clinical and preclinical studies are ongoing worldwide. In preclinical settings, high-quality cartilage tissue has been produced using combination strategies involving stem or progenitor cells, biomaterials, and biomolecules to generate a construct for implantation at the lesion site. Cell numbers and mechanical stimulation of the constructs are not commonly considered, but are important parameters to be evaluated in forthcoming clinical studies. We review current clinical and preclinical studies for advanced therapy cartilage regeneration and evaluate the progress of the field.

  18. Stimulating endogenous cardiac repair

    PubMed Central

    Finan, Amanda; Richard, Sylvain

    2015-01-01

    The healthy adult heart has a low turnover of cardiac myocytes. The renewal capacity, however, is augmented after cardiac injury. Participants in cardiac regeneration include cardiac myocytes themselves, cardiac progenitor cells, and peripheral stem cells, particularly from the bone marrow compartment. Cardiac progenitor cells and bone marrow stem cells are augmented after cardiac injury, migrate to the myocardium, and support regeneration. Depletion studies of these populations have demonstrated their necessary role in cardiac repair. However, the potential of these cells to completely regenerate the heart is limited. Efforts are now being focused on ways to augment these natural pathways to improve cardiac healing, primarily after ischemic injury but in other cardiac pathologies as well. Cell and gene therapy or pharmacological interventions are proposed mechanisms. Cell therapy has demonstrated modest results and has passed into clinical trials. However, the beneficial effects of cell therapy have primarily been their ability to produce paracrine effects on the cardiac tissue and recruit endogenous stem cell populations as opposed to direct cardiac regeneration. Gene therapy efforts have focused on prolonging or reactivating natural signaling pathways. Positive results have been demonstrated to activate the endogenous stem cell populations and are currently being tested in clinical trials. A potential new avenue may be to refine pharmacological treatments that are currently in place in the clinic. Evidence is mounting that drugs such as statins or beta blockers may alter endogenous stem cell activity. Understanding the effects of these drugs on stem cell repair while keeping in mind their primary function may strike a balance in myocardial healing. To maximize endogenous cardiac regeneration, a combination of these approaches could ameliorate the overall repair process to incorporate the participation of multiple cellular players. PMID:26484341

  19. An official American Thoracic Society workshop report: stem cells and cell therapies in lung biology and diseases.

    PubMed

    Weiss, Daniel J; Chambers, Daniel; Giangreco, Adam; Keating, Armand; Kotton, Darrell; Lelkes, Peter I; Wagner, Darcy E; Prockop, Darwin J

    2015-04-01

    The University of Vermont College of Medicine and the Vermont Lung Center, in collaboration with the NHLBI, Alpha-1 Foundation, American Thoracic Society, European Respiratory Society, International Society for Cell Therapy, and the Pulmonary Fibrosis Foundation, convened a workshop, "Stem Cells and Cell Therapies in Lung Biology and Lung Diseases," held July 29 to August 1, 2013 at the University of Vermont. The conference objectives were to review the current understanding of the role of stem and progenitor cells in lung repair after injury and to review the current status of cell therapy and ex vivo bioengineering approaches for lung diseases. These are all rapidly expanding areas of study that both provide further insight into and challenge traditional views of mechanisms of lung repair after injury and pathogenesis of several lung diseases. The goals of the conference were to summarize the current state of the field, discuss and debate current controversies, and identify future research directions and opportunities for both basic and translational research in cell-based therapies for lung diseases. This conference was a follow-up to four previous biennial conferences held at the University of Vermont in 2005, 2007, 2009, and 2011. Each of those conferences, also sponsored by the National Institutes of Health, American Thoracic Society, and Respiratory Disease Foundations, has been important in helping guide research and funding priorities. The major conference recommendations are summarized at the end of the report and highlight both the significant progress and major challenges in these rapidly progressing fields.

  20. Gene therapy progress and prospects: stem cell plasticity.

    PubMed

    Kashofer, K; Bonnet, D

    2005-08-01

    With the identification of stem cell plasticity several years ago, multiple reports raised hopes that tissue repair by stem cell transplantation could be within reach in the near future. Krause et al reported that a single purified hematopoietic stem cell not only repopulated the bone marrow of a host animal, but also integrated into unrelated tissues. Lagasse et al demonstrated that in a genetic model of liver disease, purified hematopoietic stem cells can give rise to hepatocytes and rescue fatal liver damage. More recent work by Jiang et al demonstrated that cultured cells can retain their stem cell potential. There are a number of possible mechanisms that could explain these phenomena, and recent experiments have raised controversy about which mechanism is prevalent. One possibility is transdifferentiation of a committed cell directly into another cell type as a response to environmental cues. Transdifferentiation has been shown mainly in vitro, but some in vivo data also support this mechanism. Direct transdifferentiation would clinically be limited by the number of cells that can be introduced into an organ without removal of resident cells. If bone marrow cells could on the other hand give rise to stem cells of another tissue, then they could in theory repopulate whole organs from a few starting cells. This model of dedifferentiation is consistent with recent data from animal models. Genetic analysis of cells of donor origin in vivo and in vitro has brought to light another possible mechanism. The fusion of host and donor cells can give rise to mature tissue cells without trans- or dedifferentiation. The resulting heterokaryons are able to cure a lethal genetic defect and do not seem to be prone to give rise to cancer. All these models will clinically face the problem of accessibility of healthy primary cells for transplantation. This underlines the importance of the recent identification of a population of mesenchymal stem cells (MSCs) with stem cell

  1. Differential repair of DNA damage in specific nucleotide sequences in monkey cells.

    PubMed Central

    Leadon, S A

    1986-01-01

    An immunological method was developed that isolates DNA fragments containing bromouracil in repair patches from unrepaired DNA using a monoclonal antibody that recognizes bromouracil. Cultured monkey cells were exposed to either UV light or the activated carcinogen aflatoxin B1 and excision repair of damage in DNA fragments containing the integrated and transcribed E. coli gpt gene was compared to that in the genome overall. A more rapid repair, of both UV and AFB1 damage was observed in the DNA fragments containing the E. coli gpt genes. The more efficient repair of UV damage was not due to a difference in the initial level of pyrimidine dimers as determined with a specific UV endonuclease. Consistent with previous observations using different methodology, repair of UV damage in the alpha sequences was found to occur at the same rate as that in the genome overall, while repair of AFB1 damage was deficient in alpha DNA. The preferential repair of damage in the gpt gene may be related to the functional state of the sequence and/or to alterations produced in the chromatin conformation by the integration of plasmid sequences carrying the gene. Images PMID:3786142

  2. Proteomic identification of hair cell repair proteins in the model sea anemone Nematostella vectensis.

    PubMed

    Tang, Pei-Ciao; Watson, Glen M

    2015-09-01

    Sea anemones have an extraordinary capability to repair damaged hair bundles, even after severe trauma. A group of secreted proteins, named repair proteins (RPs), found in mucus covering sea anemones significantly assists the repair of damaged hair bundle mechanoreceptors both in the sea anemone Haliplanella luciae and the blind cavefish Astyanax hubbsi. The polypeptide constituents of RPs must be identified in order to gain insight into the molecular mechanisms by which repair of hair bundles is accomplished. In this study, several polypeptides of RPs were isolated from mucus using blue native PAGE and then sequenced using LC-MS/MS. Thirty-seven known polypeptides were identified, including Hsp70s, as well as many polypeptide subunits of the 20S proteasome. Other identified polypeptides included those involved in cellular stress responses, protein folding, and protein degradation. Specific inhibitors of Hsp70s and the 20S proteasome were employed in experiments to test their involvement in hair bundle repair. The results of those experiments suggested that repair requires biologically active Hsp70s and 20S proteasomes. A model is proposed that considers the function of extracellular Hsp70s and 20S proteasomes in the repair of damaged hair cells.

  3. Wound repair and proliferation of bronchial epithelial cells enhanced by bombesin receptor subtype 3 activation.

    PubMed

    Tan, Yu-Rong; Qi, Ming-Ming; Qin, Xiao-Qun; Xiang, Yang; Li, Xiang; Wang, Yue; Qu, Fei; Liu, Hui-Jun; Zhang, Jian-Song

    2006-07-01

    The present study was designed to investigate the role of bombesin receptor subtype 3 (BRS-3) in airway wound repair. The results showed that: (1) There was few expression of BRS-3 mRNA in the control group. In contrast, the expression of BRS-3 mRNA was gradually increased in the early 2 days, and peaked on the fourth day, and then decreased in the ozone-stressed AHR animal. BRS-3 mRNA was distributed in the ciliated columnar epithelium, monolayer columnar epithelium cells, scattered mesenchymal cells and Type II alveolar cells; (2) The wound repair and proliferation of bronchial epithelial cells (BECs) were accelerated in a concentration-dependent manner by BRS-3 activation with P3513, which could be inhibited by PKA inhibitor H89. The study demostrated that activation of BRS-3 may play an important role in wound repair of AHR.

  4. Genetically corrected iPSCs as cell therapy for recessive dystrophic epidermolysis bullosa.

    PubMed

    Wenzel, Daniel; Bayerl, Jonathan; Nyström, Alexander; Bruckner-Tuderman, Leena; Meixner, Arabella; Penninger, Josef M

    2014-11-26

    Recessive dystrophic epidermolysis bullosa (RDEB) is caused by mutations in the gene encoding type VII collagen, resulting in fragile skin and mucous membranes that blister easily in response to mechanical stress. Induced pluripotent stem cells (iPSCs) carry the potential to fundamentally change cell-based therapies for human diseases, in particular for RDEB, for which no effective treatments are available. To provide proof of principle on the applicability of iPSCs for the treatment of RDEB, we developed iPSCs from type VII collagen (Col7a1) mutant mice that exhibited skin fragility and blistering resembling human RDEB. Genetically repaired iPSCs could be differentiated into functional fibroblasts that reexpressed and secreted type VII collagen. Corrected iPSC-derived fibroblasts did not form tumors in vivo and could be traced up to 16 weeks after intradermal injection. Moreover, iPSC-based cell therapy resulted in faithful and long-term restoration of type VII collagen deposition at the epidermal-dermal junction of Col7a1 mutant mice. Intradermal injection of genetically repaired iPSC-derived fibroblasts restored the mechanical resistance to skin blistering in mice with RDEB, suggesting that RDEB skin could be effectively and safely repaired using iPSC-based cell therapy.

  5. Translational aspects of cardiac cell therapy

    PubMed Central

    Chen, Cheng-Han; Sereti, Konstantina-Ioanna; Wu, Benjamin M; Ardehali, Reza

    2015-01-01

    Cell therapy has been intensely studied for over a decade as a potential treatment for ischaemic heart disease. While initial trials using skeletal myoblasts, bone marrow cells and peripheral blood stem cells showed promise in improving cardiac function, benefits were found to be short-lived likely related to limited survival and engraftment of the delivered cells. The discovery of putative cardiac ‘progenitor’ cells as well as the creation of induced pluripotent stem cells has led to the delivery of cells potentially capable of electromechanical integration into existing tissue. An alternative strategy involving either direct reprogramming of endogenous cardiac fibroblasts or stimulation of resident cardiomyocytes to regenerate new myocytes can potentially overcome the limitations of exogenous cell delivery. Complimentary approaches utilizing combination cell therapy and bioengineering techniques may be necessary to provide the proper milieu for clinically significant regeneration. Clinical trials employing bone marrow cells, mesenchymal stem cells and cardiac progenitor cells have demonstrated safety of catheter based cell delivery, with suggestion of limited improvement in ventricular function and reduction in infarct size. Ongoing trials are investigating potential benefits to outcome such as morbidity and mortality. These and future trials will clarify the optimal cell types and delivery conditions for therapeutic effect. PMID:26119413

  6. Cell therapy for diabetes mellitus: an opportunity for stem cells?

    PubMed

    Soria, B; Bedoya, F J; Tejedo, J R; Hmadcha, A; Ruiz-Salmerón, R; Lim, S; Martin, F

    2008-01-01

    Diabetes is a chronic disease characterized by a deficit in beta cell mass and a failure of glucose homeostasis. Both circumstances result in a variety of severe complications and an overall shortened life expectancy. Thus, diabetes represents an attractive candidate for cell therapy. Reversal of diabetes can be achieved through pancreas and islet transplantation, but shortage of donor organs has prompted an intensive search for alternative sources of beta cells. This achievement has stimulated the search for appropriate stem cell sources. Both embryonic and adult stem cells have been used to generate surrogate beta cells or otherwise restore beta cell functioning. In this regard, several studies have reported the generation of insulin-secreting cells from embryonic and adult stem cells that normalized blood glucose values when transplanted into diabetic animal models. Due to beta cell complexity, insulin-producing cells generated from stem cells do not possess all beta cell attributes. This indicates the need for further development of methods for differentiation and selection of completely functional beta cells. While these problems are overcome, diabetic patients may benefit from therapeutic strategies based on autologous stem cell therapies addressing late diabetic complications. In this article, we discuss the recent progress in the generation of insulin-producing cells from embryonic and adult stem cells, together with the challenges for the clinical use of diabetes stem cell therapy.

  7. Cell-based therapies for regenerating bone

    PubMed Central

    GOODMAN, S. B.

    2013-01-01

    Cellular therapies to replenish bone lost due to acquired conditions such as trauma, infection, tumor, periprosthetic osteolysis and other etiologies have become widespread. Traditional, open, surgical bone grafting techniques have given way to newer cellular therapies that are potentially less invasive and have a lower complication rate and faster recovery time. These new technologies include bone marrow harvesting with concentration of osteoprogenitor cells with/without cell culture, scaffolds which are both osteoconductive and osteoinductive, attempts to facilitate mesenchymal stem cell and osteoprogenitor cell homing both locally and systemically, genetic engineering of specialized stem cells, and the use of potentially immune-privileged fetal and other types of stem cells. Some of these techniques have already been introduced into the orthopaedic clinic, whereas others are still in the pre-clinical testing phase. Given the limited supply of autologous graft, these new techniques will have a dramatic impact on bone regeneration in the future. PMID:24436510

  8. Regeneration of the retina: toward stem cell therapy for degenerative retinal diseases.

    PubMed

    Jeon, Sohee; Oh, Il-Hoan

    2015-04-01

    Degenerative retinal diseases affect millions of people worldwide, which can lead to the loss of vision. However, therapeutic approaches that can reverse this process are limited. Recent efforts have allowed the possibility of the stem cell-based regeneration of retinal cells and repair of injured retinal tissues. Although the direct differentiation of pluripotent stem cells into terminally differentiated photoreceptor cells comprises one approach, a series of studies revealed the intrinsic regenerative potential of the retina using endogenous retinal stem cells. Muller glial cells, ciliary pigment epithelial cells, and retinal pigment epithelial cells are candidates for such retinal stem cells that can differentiate into multiple types of retinal cells and be integrated into injured or developing retina. In this review, we explore our current understanding of the cellular identity of these candidate retinal stem cells and their therapeutic potential for cell therapy against degenerative retinal diseases.

  9. Mesenchymal stem cells stimulate intestinal stem cells to repair radiation-induced intestinal injury

    PubMed Central

    Gong, Wei; Guo, Mengzheng; Han, Zhibo; Wang, Yan; Yang, Ping; Xu, Chang; Wang, Qin; Du, Liqing; Li, Qian; Zhao, Hui; Fan, Feiyue; Liu, Qiang

    2016-01-01

    The loss of stem cells residing in the base of the intestinal crypt has a key role in radiation-induced intestinal injury. In particular, Lgr5+ intestinal stem cells (ISCs) are indispensable for intestinal regeneration following exposure to radiation. Mesenchymal stem cells (MSCs) have previously been shown to improve intestinal epithelial repair in a mouse model of radiation injury, and, therefore, it was hypothesized that this protective effect is related to Lgr5+ ISCs. In this study, it was found that, following exposure to radiation, transplantation of MSCs improved the survival of the mice, ameliorated intestinal injury and increased the number of regenerating crypts. Furthermore, there was a significant increase in Lgr5+ ISCs and their daughter cells, including Ki67+ transient amplifying cells, Vil1+ enterocytes and lysozyme+ Paneth cells, in response to treatment with MSCs. Crypts isolated from mice treated with MSCs formed a higher number of and larger enteroids than those from the PBS group. MSC transplantation also reduced the number of apoptotic cells within the small intestine at 6 h post-radiation. Interestingly, Wnt3a and active β-catenin protein levels were increased in the small intestines of MSC-treated mice. In addition, intravenous delivery of recombinant mouse Wnt3a after radiation reduced damage in the small intestine and was radioprotective, although not to the same degree as MSC treatment. Our results show that MSCs support the growth of endogenous Lgr5+ ISCs, thus promoting repair of the small intestine following exposure to radiation. The molecular mechanism of action mediating this was found to be related to increased activation of the Wnt/β-catenin signaling pathway. PMID:27685631

  10. Melatonin as a promising agent of regulating stem cell biology and its application in disease therapy.

    PubMed

    Zhang, Shuo; Chen, Simon; Li, Yuan; Liu, Yu

    2017-03-01

    Stem cells have emerged as an important approach to repair and regenerate damaged tissues or organs and show great therapeutic potential in a variety of diseases. However, the low survival of engrafted stem cells still remains a major challenge for stem cell therapy. As a major hormone from the pineal gland, melatonin has been shown to play an important role in regulating the physiological and pathological functions of stem cells, such as promoting proliferation, migration and differentiation. Thus, melatonin combined with stem cell transplantation displayed promising application potential in neurodegenerative diseases, liver cirrhosis, wound healing, myocardial infarction, kidney ischemia injury, osteoporosis, etc. It exerts its physiological and pathological functions through its anti-oxidant, anti-inflammatory, anti-apoptosis and anti-ageing properties. Here, we summarize recent advances on exploring the biological role of melatonin in stem cells, and discuss its potential applications in stem cell-based therapy.

  11. An Official American Thoracic Society Workshop Report 2015. Stem Cells and Cell Therapies in Lung Biology and Diseases.

    PubMed

    Wagner, Darcy E; Cardoso, Wellington V; Gilpin, Sarah E; Majka, Susan; Ott, Harald; Randell, Scott H; Thébaud, Bernard; Waddell, Thomas; Weiss, Daniel J

    2016-08-01

    The University of Vermont College of Medicine, in collaboration with the NHLBI, Alpha-1 Foundation, American Thoracic Society, Cystic Fibrosis Foundation, European Respiratory Society, International Society for Cellular Therapy, and the Pulmonary Fibrosis Foundation, convened a workshop, "Stem Cells and Cell Therapies in Lung Biology and Lung Diseases," held July 27 to 30, 2015, at the University of Vermont. The conference objectives were to review the current understanding of the role of stem and progenitor cells in lung repair after injury and to review the current status of cell therapy and ex vivo bioengineering approaches for lung diseases. These are all rapidly expanding areas of study that both provide further insight into and challenge traditional views of mechanisms of lung repair after injury and pathogenesis of several lung diseases. The goals of the conference were to summarize the current state of the field, discuss and debate current controversies, and identify future research directions and opportunities for both basic and translational research in cell-based therapies for lung diseases. This 10th anniversary conference was a follow up to five previous biennial conferences held at the University of Vermont in 2005, 2007, 2009, 2011, and 2013. Each of those conferences, also sponsored by the National Institutes of Health, American Thoracic Society, and respiratory disease foundations, has been important in helping guide research and funding priorities. The major conference recommendations are summarized at the end of the report and highlight both the significant progress and major challenges in these rapidly progressing fields.

  12. Potential benefits and limitations of utilizing chondroprogenitors in cell-based cartilage therapy.

    PubMed

    Jayasuriya, Chathuraka T; Chen, Qian

    2015-01-01

    Chondroprogenitor cells are a subpopulation of multipotent progenitors that are primed for chondrogenesis. They are believed to have the biological repertoire to be ideal for cell-based cartilage therapy. In addition to summarizing recent advances in chondroprogenitor cell characterization, this review discusses the projected pros and cons of utilizing chondroprogenitors in regenerative medicine and compares them with that of pre-existing methods, including autologous chondrocyte implantation (ACI) and the utilization of bone marrow derived mesenchymal stem cells (MSCs) for the purpose of cartilage tissue repair.

  13. Efficiency of Cell Therapy in Liver Cirrhosis.

    PubMed

    Shevela, E Ya; Starostina, N M; Pal'tsev, A I; Shipunov, M V; Zheltova, O I; Meledina, I V; Khvan, L A; Leplina, O Yu; Ostanin, A A; Chernykh, E R; Kozlov, V A

    2016-02-01

    We studied safety and clinical efficacy of transplantation of autologous bone marrow cell in complex therapy of 158 patients with chronic hepatitis and cirrhosis of the liver. The efficiency of cell therapy was assessed in 12 months after single injection of the cells. The positive response (alleviation of liver cirrhosis or stabilization of the pathological process) was observed in 70% cases. The efficacy of therapy correlated with the severity and etiology of the disease and was maximum in patients with Child-Pugh class A (in 82.5% cases) and class B liver cirrhosis (in 79% cases); in patients with class C liver cirrhosis, the positive response was achieved in 42.5% cases. In 39 patients, ultrasonic examination performed in 3 years after transplantation revealed no focal lesions or ectopic ossification foci.

  14. Repair of ionizing radiation DNA base damage in ataxia-telangiectasia cells

    SciTech Connect

    Fornace, A.J. Jr.; Kinsella, T.J.; Dobson, P.P.; Mitchell, J.B.

    1986-04-01

    Micrococcus luteus endonuclease sensitive sites were measured by alkaline elution in normal human and ataxia-telangiectasia (AT) fibroblasts after ionizing radiation. Due to the sensitivity of this assay, repair of base damage after 3 to 6 kilorads has been measured after oxic or hypoxic radiation. With 5.5 kilorads of oxic radiation, more than 50% of the base damage was removed after 1.5 h of repair incubation in all cells, including exr+ and exr- AT cells, and approximately 75% was removed by 4 h. After 3 or 4.5 kilorads of hypoxic X-irradiation, repair was equivalent in normal and exr- AT cells. This study included three exr- AT strains which have been reported to be deficient in the removal of gamma-ray base damage at higher doses. Since these strains repaired ionizing radiation base damage normally at lower doses, which are more relevant to survival, it is concluded that the X-ray hypersensitivity of AT cells is probably not related to the repair of base damage.

  15. Ultraviolet irradiation of monkey cells enhances the repair of DNA adducts in alpha DNA

    SciTech Connect

    Leadon, S.A.; Hanawalt, P.C.

    1984-11-01

    Excision repair of bulky adducts in alpha DNA of African green monkey cells has previously been shown to be deficient relative to that in the overall genome. We have found that u.v. irradiation of these cells results in the enhanced removal of both aflatoxin B1 (AFB1) and acetylaminofluorene (AAF) adducts from the alpha DNA sequences without affecting repair in the bulk of the DNA. The degree of enhanced removal of AFB1 is dependent upon the u.v. dose and the time interval between irradiation and AFB1 treatment. The u.v. enhancement is not inhibited by cycloheximide. Exposure of the cells to dimethylsulfate or gamma-rays does not affect AFB1 adduct repair. The formation and removal of N-acetoxy-2-acetylaminofluorene (NA-AAF) adducts from alpha and bulk DNA was studied in detail. A higher initial level of the acetylated C8 adduct of guanine was found in alpha DNA than in bulk DNA. Although both the acetylated and deacetylated C8 adducts were removed from the two DNA species, the level of repair was significantly greater in the bulk DNA. Irradiation of cells with u.v. prior to treatment with NA-AAF enhanced the removal of both adducts from alpha DNA with little or no effect on repair in bulk DNA. We conclude that the presence of u.v. photoproducts or some intermediate in their processing alters the chromatin structure of alpha DNA thereby rendering bulky adducts accessible to repair enzymes. In addition, the differential formation and repair of AAF adducts in alpha DNA compared with that in the bulk of the genome supports the hypothesis of an altered chromatin structure for alpha domains.

  16. Nanotechnology for mesenchymal stem cell therapies.

    PubMed

    Corradetti, Bruna; Ferrari, Mauro

    2016-10-28

    Mesenchymal stem cells (MSC) display great proliferative, differentiative, chemotactic, and immune-modulatory properties required to promote tissue repair. Several clinical trials based on the use of MSC are currently underway for therapeutic purposes. The aim of this article is to examine the current trends and potential impact of nanotechnology in MSC-driven regenerative medicine. Nanoparticle-based approaches are used as powerful carrier systems for the targeted delivery of bioactive molecules to ensure MSC long-term maintenance in vitro and to enhance their regenerative potential. Nanostructured materials have been developed to recapitulate the stem cell niche within a tissue and to instruct MSC toward the creation of regeneration-permissive environment. Finally, the capability of MSC to migrate toward the site of injury/inflammation has allowed for the development of diagnostic imaging systems able to monitor transplanted stem cell bio-distribution, toxicity, and therapeutic effectiveness.

  17. Secretion of IL-13 by airway epithelial cells enhances epithelial repair via HB-EGF.

    PubMed

    Allahverdian, Sima; Harada, Norihiro; Singhera, Gurpreet K; Knight, Darryl A; Dorscheid, Delbert R

    2008-02-01

    Inappropriate repair after injury to the epithelium generates persistent activation, which may contribute to airway remodeling. In the present study we hypothesized that IL-13 is a normal mediator of airway epithelial repair. Mechanical injury of confluent airway epithelial cell (AEC) monolayers induced expression and release of IL-13 in a time-dependent manner coordinate with repair. Neutralizing of IL-13 secreted from injured epithelial cells by shIL-13Ralpha2.FC significantly reduced epithelial repair. Moreover, exogenous IL-13 enhanced epithelial repair and induced epidermal growth factor receptor (EGFR) phosphorylation. We examined secretion of two EGFR ligands, epidermal growth factor (EGF) and heparin-binding EGF (HB-EGF), after mechanical injury. Our data showed a sequential release of the EGF and HB-EGF by AEC after injury. Interestingly, we found that IL-13 induces HB-EGF, but not EGF, synthesis and release from AEC. IL-13-induced EGFR phosphorylation and the IL-13-reparative effect on AEC are mediated via HB-EGF. Finally, we demonstrated that inhibition of EGFR tyrosine kinase activity by tyrphostin AG1478 increases IL-13 release after injury, suggesting negative feedback between EGFR and IL-13 during repair. Our data, for the first time, showed that IL-13 plays an important role in epithelial repair, and that its effect is mediated through the autocrine release of HB-EGF and activation of EGFR. Dysregulation of EGFR phosphorylation may contribute to a persistent repair phenotype and chronically increased IL-13 release, and in turn result in airway remodeling.

  18. Peripheral Nerve Injury: Stem Cell Therapy and Peripheral Nerve Transfer

    PubMed Central

    Sullivan, Robert; Dailey, Travis; Duncan, Kelsey; Abel, Naomi; Borlongan, Cesario V.

    2016-01-01

    Peripheral nerve injury can lead to great morbidity in those afflicted, ranging from sensory loss, motor loss, chronic pain, or a combination of deficits. Over time, research has investigated neuronal molecular mechanisms implicated in nerve damage, classified nerve injury, and developed surgical techniques for treatment. Despite these advancements, full functional recovery remains less than ideal. In this review, we discuss historical aspects of peripheral nerve injury and introduce nerve transfer as a therapeutic option, as well as an adjunct therapy to transplantation of Schwann cells and their stem cell derivatives for repair of the damaged nerve. This review furthermore, will provide an elaborated discussion on the sources of Schwann cells, including sites to harvest their progenitor and stem cell lines. This reflects the accessibility to an additional, concurrent treatment approach with nerve transfers that, predicated on related research, may increase the efficacy of the current approach. We then discuss the experimental and clinical investigations of both Schwann cells and nerve transfer that are underway. Lastly, we provide the necessary consideration that these two lines of therapeutic approaches should not be exclusive, but conversely, should be pursued as a combined modality given their mutual role in peripheral nerve regeneration. PMID:27983642

  19. Repair-deficient xeroderma pigmentosum cells made UV light resistant by fusion with X-ray-inactivated Chinese hamster cells

    SciTech Connect

    Karentz, D.; Cleaver, J.E.

    1986-10-01

    Xeroderma pigmentosum (XP) is an autosomal recessive human disease, characterized by an extreme sensitivity to sunlight, caused by the inability of cells to repair UV light-induced damage to DNA. Cell fusion was used to transfer fragments of Chinese hamster ovary (CHO) chromosomes into XP cells. The hybrid cells exhibited UV resistance and DNA repair characteristics comparable to those expressed by CHO cells, and their DNA had greater homology with CHO DNA than did the DNA from XP cells. Control experiments consisted of fusion of irradiated and unirradiated XP cells and repeated exposure of unfused XP cells to UV doses used for hybrid selection. These treatments did not result in an increase in UV resistance, repair capability, or homology with CHO DNA. The hybrid cell lines do not, therefore, appear to be XP revertants. The establishment of these stable hybrid cell lines is an initial step toward identifying and cloning CHO DNA repair genes that complement the XP defect in human cells. The method should also be applicable to cloning genes for other diseases, such as ataxia-telangiectasia and Fanconi's anemia.

  20. The role of DNA repair on cell killing by charged particles

    NASA Astrophysics Data System (ADS)

    Eguchi-Kasai, K.; Murakami, M.; Itsukaichi, H.; Fukutsu, K.; Kanai, T.; Furusawa, Y.; Sato, K.; Ohara, H.; Yatagai, F.

    It can be noted that it is not simple double strand breaks (dsb) but the non-reparable breaks that are associated with high biological effectiveness in the cell killing effect for high LET radiation. Here, we have examined the effectiveness of fast neutrons and low (initial energy = 12 MeV/u) or high (135 MeV/u) energy charged particles on cell death in 19 mammalian cell lines including radiosensitive mutants. Some of the radiosensitive lines were deficient in DNA dsb repair such as LX830, M10, V3, and L5178Y-S cells and showed lower values of relative biological effectiveness (RBE) for fast neutrons if compared with their parent cell lines. The other lines of human ataxia-telangiectasia fibroblasts, irs 1, irs 2, irs 3 and irs1SF cells, which were also radiosensitive but known as proficient in dsb repair, showed moderate RBEs. Dsb repair deficient mutants showed low RBE values for heavy ions. These experimental findings suggest that the DNA repair system does not play a major role against the attack of high linear energy transfer (LET) radiations. Therefore, we hypothesize that a main cause of cell death induced by high LET radiations is due to non-reparable dsb, which are produced at a higher rate compared to low LET radiations.

  1. ACE2/Ang-(1-7)/Mas axis stimulates vascular repair-relevant functions of CD34+ cells.

    PubMed

    Singh, Neha; Joshi, Shrinidh; Guo, Lirong; Baker, Matthew B; Li, Yan; Castellano, Ronald K; Raizada, Mohan K; Jarajapu, Yagna P R

    2015-11-15

    CD34(+) stem/progenitor cells have been identified as a promising cell population for the autologous cell-based therapies in patients with cardiovascular disease. The counter-regulatory axes of renin angiotensin system, angiotensin converting enzyme (ACE)/Ang II/angiotensin type 1 (AT1) receptor and ACE2/Ang-(1-7)/Mas receptor, play an important role in the cardiovascular repair. This study evaluated the expression and vascular repair-relevant functions of these two pathways in human CD34(+) cells. CD34(+) cells were isolated from peripheral blood mononuclear cells (MNCs), obtained from healthy volunteers. Expression of ACE, ACE2, AT1, and angiotensin type 2 and Mas receptors were determined. Effects of Ang II, Ang-(1-7), Norleu(3)-Ang-(1-7), and ACE2 activators, xanthenone (XNT) and diminazene aceturate (DIZE) on proliferation, migration, and adhesion of CD34(+) cells were evaluated. ACE2 and Mas were relatively highly expressed in CD34(+) cells compared with MNCs. Ang-(1-7) or its analog, Norleu(3)-Ang-(1-7), stimulated proliferation of CD34(+) cells that was associated with decrease in phosphatase and tensin homologue deleted on chromosome 10 levels and was inhibited by triciribin, an AKT inhibitor. Migration of CD34(+) cells was enhanced by Ang-(1-7) or Norleu(3)-Ang-(1-7) that was decreased by a Rho-kinase inhibitor, Y-27632. In the presence of Ang II, XNT or DIZE enhanced proliferation and migration that were blocked by DX-600, an ACE2 inhibitor. Treatment of MNCs with Ang II, before the isolation of CD34(+) cells, attenuated the proliferation and migration to stromal derived factor-1α. This attenuation was reversed by apocynin, an NADPH oxidase inhibitor. Adhesion of MNCs or CD34(+) cells to fibronectin was enhanced by Ang II and was unaffected by Ang-(1-7). This study suggests that ACE2/Ang-(1-7)/Mas pathway stimulates functions of CD34(+) cells that are cardiovascular protective, whereas Ang II attenuates these functions by acting on MNCs. These findings

  2. Repair of DNA-protein cross-links in an excision repair-deficient human cell line and its simian virus 40-transformed derivative

    SciTech Connect

    Gantt, R.; Taylor, W.G.; Camalier, R.F.; Stephens, E.V.

    1984-05-01

    DNA-protein cross-links are induced in mammalian cells by X-rays, ultraviolet light, fluorescent light, and numerous chemical carcinogens. Others have shown that these cross-links are repaired by normal cells but that excision repair-deficient xeroderma pigmentosum (XP) Group A cells, XP12BE, are deficient in repair of these bulky adducts. This paper compares the DNA-protein cross-link repair competency of another XP Group A strain, XP20S, with its more rapidly proliferating simian virus 40-transformed derivative line and with normal human skin fibroblasts. DNA-protein cross-links were induced with 20 microM transplatinum(II)diamminedichloride and assayed by the membrane alkaline elution procedure of Kohn. Treated and untreated cells are lysed on a polycarbonate membrane filter, and the coelution rates of the DNA at pH 12.2 are compared; DNA-protein cross-links retard elution of DNA. The repair competency of XP20S cells for trans-platinum(II)diamminedichloride-induced DNA-protein cross-links was similar to that of XP12BE cells, but the competency of the simian virus 40-transformed XP20S cells was nearly equal to that of normal human skin fibroblasts. These results suggest that either cell cycling compensates for the genetic deficiency present in the nucleotide excision process of XP Group A cells or that a process other than nucleotide excision can repair these lesions; this process requires cell cycling or activation by the virus.

  3. Inflammation and the Intestinal Barrier: Leukocyte–Epithelial Cell Interactions, Cell Junction Remodeling, and Mucosal Repair

    PubMed Central

    Luissint, Anny-Claude; Parkos, Charles A.; Nusrat, Asma

    2017-01-01

    The intestinal tract is lined by a single layer of columnar epithelial cells that forms a dynamic, permeable barrier allowing for selective absorption of nutrients, while restricting access to pathogens and food-borne antigens. Precise regulation of epithelial barrier function is therefore required for maintaining mucosal homeostasis and depends, in part, on barrier-forming elements within the epithelium and a balance between pro- and anti-inflammatory factors in the mucosa. Pathologic states, such as inflammatory bowel disease, are associated with a leaky epithelial barrier, resulting in excessive exposure to microbial antigens, recruitment of leukocytes, release of soluble mediators, and ultimately mucosal damage. An inflammatory microenvironment affects epithelial barrier properties and mucosal homeostasis by altering the structure and function of epithelial intercellular junctions through direct and indirect mechanisms. We review our current understanding of complex interactions between the intestinal epithelium and immune cells, with a focus on pathologic mucosal inflammation and mechanisms of epithelial repair. We discuss leukocyte–epithelial interactions, as well as inflammatory mediators that affect the epithelial barrier and mucosal repair. Increased knowledge of communication networks between the epithelium and immune system will lead to tissue-specific strategies for treating pathologic intestinal inflammation. PMID:27436072

  4. Germline Stem Cell Gene PIWIL2 Mediates DNA Repair through Relaxation of Chromatin

    PubMed Central

    Yin, De-Tao; Wang, Qien; Chen, Li; Liu, Meng-Yao; Han, Chunhua; Yan, Qingtao; Shen, Rulong; He, Gang; Duan, Wenrui; Li, Jian-Jian; Wani, Altaf; Gao, Jian-Xin

    2011-01-01

    DNA damage response (DDR) is an intrinsic barrier of cell to tumorigenesis initiated by genotoxic agents. However, the mechanisms underlying the DDR are not completely understood despite of extensive investigation. Recently, we have reported that ectopic expression of germline stem cell gene PIWIL2 is associated with tumor stem cell development, although the underlying mechanisms are largely unknown. Here we show that PIWIL2 is required for the repair of DNA-damage induced by various types of genotoxic agents. Upon ultraviolet (UV) irradiation, silenced PIWIL2 gene in normal human fibroblasts was transiently activated after treatment with UV light. This activation was associated with DNA repair, because Piwil2-deficienct mouse embryonic fibroblasts (mili-/- MEFs) were defective in cyclobutane pyrimidine dimers (CPD) repair after UV treatment. As a result, the UV-treated mili-/- MEFs were more susceptible to apoptosis, as characterized by increased levels of DNA damage-associated apoptotic proteins, such as active caspase-3, cleaved Poly (ADP-ribose) polymerase (PARP) and Bik. The impaired DNA repair in the mili-/- MEFs was associated with the reductions of histone H3 acetylation and chromatin relaxation, although the DDR pathway downstream chromatin relaxation appeared not to be directly affected by Piwil2. Moreover, guanine–guanine (Pt-[GG]) and double strand break (DSB) repair were also defective in the mili-/- MEFs treated by genotoxic chemicals Cisplatin and ionizing radiation (IR), respectively. The results indicate that Piwil2 can mediate DNA repair through an axis of Piwil2 → histone acetylation → chromatin relaxation upstream DDR pathways. The findings reveal a new role for Piwil2 in DNA repair and suggest that Piwil2 may act as a gatekeeper against DNA damage-mediated tumorigenesis. PMID:22110608

  5. Role of ATP in UV-induced DNA excision repair in human cells

    SciTech Connect

    Dresler, S.L.

    1986-05-01

    In permeable human fibroblasts, UV-induced DNA excision repair is dependent on ATP, with a K/sub m/ of approximately 1 mM. Omission of ATP from the reaction mix completely inhibits damage-specific incision of DNA, but has little effect on repair patch synthesis proceeding from previously incised sites. UV-induced excision repair in permeable xeroderma pigmentosum (XP) cells complemented with T4 UV endonuclease is also totally dependent on ATP. Because the T4 enzyme is not ATP-dependent, ATP must be required for an endogenous activity other than the incision of damaged DNA. Alkaline elution reveals that, in the absence of ATP, T4 UV endonuclease does incise the DNA of permeable UV-irradiated XP cells, but that the incision rate is stimulated approximately 2-fold by the addition of ATP. This 2-fold stimulation of incision can not, however, be responsible for the absolute ATP dependence of excision repair in UV endonuclease-complemented XP cells. Apparently, although T4 UV endonuclease can incise damaged nuclear DNA in the absence of ATP, the incised sites must also be altered in an ATP-dependent reaction before subsequent steps of the repair process can proceed. This conclusion, coupled with the fact that ATP stimulates incision of damaged nuclear DNA by T4 UV endonuclease and is absolutely required for incision of damaged nuclear DNA by the endogenous human UV endonuclease, suggests that an important function of the early ATP-dependent step in UV-induced excision repair is to make damaged sites in DNA accessible to repair enzymes.

  6. Studying nucleotide excision repair of mammalian DNA in a cell-free system

    SciTech Connect

    Wood, R.D.

    1994-12-31

    During nucleotide excision repair, a multiprotein system locates a lesion in DNA and catalyzes enzymatic cleavage of the altered strand. The damaged oligonucleotide and the incision proteins are then displaced, DNA synthesis proceeds to form a short patch using the nonmodified strand as a template, and repair is completed by a DNA ligase. Many gene products participate in these reactions, the best known of which correspond to the seven genetic complementation groups XP-A to XP-G of the disease xeroderma pigmentosum (XP). Cells representing any of these XP groups appear to exhibit, to varying degrees, defects in the first steps of nucleotide excision repair. Individuals affected with XP are hypersensitive to sunlight; most have a predisposition to skin cancer, and some patients show severe neurological abnormalities. In addition to XP, other UV-sensitive mutants of mammalian cells are providing insight into nucleotide excision repair. Of particular interest are mutants isolated from the rodent cells, which have been assigned to 11 different complementation groups. Human genes that can correct the repair defects of rodent mutants in these complementation groups are denoted. ERCC (excision repair cross-complementing) genes are are referred to by number, ERCC1 to ERCC11. Some of these genes are proving to be equivalent to particular XP-complementing genes, while others are distinct. The process of nucleotide excision repair is evolutionarily conserved in eukaryotes, and functional homologues of many of the ERCC and XP genes have been identified in other organisms; studies in yeast are proving to be particularly informative.

  7. The less-often-traveled surface of stem cells: caveolin-1 and caveolae in stem cells, tissue repair and regeneration

    PubMed Central

    2013-01-01

    Stem cells are an important resource for tissue repair and regeneration. While a great deal of attention has focused on derivation and molecular regulation of stem cells, relatively little research has focused on how the subcellular structure and composition of the cell membrane influences stem cell activities such as proliferation, differentiation and homing. Caveolae are specialized membrane lipid rafts coated with caveolin scaffolding proteins, which can regulate cholesterol transport and the activity of cell signaling receptors and their downstream effectors. Caveolin-1 is involved in the regulation of many cellular processes, including growth, control of mitochondrial antioxidant levels, migration and senescence. These activities are of relevance to stem cell biology, and in this review evidence for caveolin-1 involvement in stem cell biology is summarized. Altered stem and progenitor cell populations in caveolin-1 null mice suggest that caveolin-1 can regulate stem cell proliferation, and in vitro studies with isolated stem cells suggest that caveolin-1 regulates stem cell differentiation. The available evidence leads us to hypothesize that caveolin-1 expression may stabilize the differentiated and undifferentiated stem cell phenotype, and transient downregulation of caveolin-1 expression may be required for transition between the two. Such regulation would probably be critical in regenerative applications of adult stem cells and during tissue regeneration. We also review here the temporal changes in caveolin-1 expression reported during tissue repair. Delayed muscle regeneration in transgenic mice overexpressing caveolin-1 as well as compromised cardiac, brain and liver tissue repair and delayed wound healing in caveolin-1 null mice suggest that caveolin-1 plays an important role in tissue repair, but that this role may be negative or positive depending on the tissue type and the nature of the repair process. Finally, we also discuss how caveolin-1

  8. NOTCH1 is required for regeneration of Clara cells during repair of airway injury.

    PubMed

    Xing, Yiming; Li, Aimin; Borok, Zea; Li, Changgong; Minoo, Parviz

    2012-05-01

    The airways of the mammalian lung are lined with highly specialized epithelial cell types that are the targets of airborne toxicants and injury. Notch signaling plays an important role in the ontogeny of airway epithelial cells, but its contributions to recruitment, expansion or differentiation of resident progenitor/stem cells, and repair and re-establishment of the normal composition of airway epithelium following injury have not been addressed. In this study, the role of a specific Notch receptor, Notch1, was investigated by targeted inactivation in the embryonic lung epithelium using the epithelial-specific Gata5-Cre driver line. Notch1-deficient mice are viable without discernible defects in pulmonary epithelial cell-fate determination and differentiation. However, in an experimental model of airway injury, activity of Notch1 is found to be required for normal repair of the airway epithelium. Absence of Notch1 reduced the ability of a population of cells distinguished by expression of PGP9.5, otherwise a marker of pulmonary neuroendocrine cells, which appears to serve as a reservoir for regeneration of Clara cells. Hairy/enhancer of split-5 (Hes5) and paired-box-containing gene 6 (Pax6) were found to be downstream targets of Notch1. Both Hes5 and Pax6 expressions were significantly increased in association with Clara cell regeneration in wild-type lungs. Ablation of Notch1 reduced Hes5 and Pax6 and inhibited airway epithelial repair. Thus, although dispensable in developmental ontogeny of airway epithelial cells, normal activity of Notch1 is required for repair of the airway epithelium. The signaling pathway by which Notch1 regulates the repair process includes stimulation of Hes5 and Pax6 gene expression.

  9. Improving Cell-Based Therapies by Nanomodification

    PubMed Central

    Chen, Wei; Fu, Liwu; Chen, Xiaoyuan

    2015-01-01

    Cell-based therapies are emerging as a promising approach for various diseases. Their therapeutic efficacy depends on rational control and regulation of the functions and behaviors of cells during their treatment. Different from conventional regulatory strategy by chemical adjuvant or genetic engineering, which is restricted by limited synergistic regulatory efficiency or uncertain safety problems, a novel approach based on nanoscale artificial materials can be applied to modify living cells to endow them with novel functions and unique properties. Inspired by the natural “nano shell” and “nano compass” structures, cell nanomodification can be developed through both external and internal pathways. In this review, some novel cell surface engineering and intracellular nanoconjugation strategies are summarized. Their potential applications are also discussed, including cell protection, cell labeling, targeted delivery and in situ regulation. It is believed that these novel cell-material complexes can have great potentials for biomedical applications. PMID:26423238

  10. Development and application of compact and on-chip electron linear accelerators for dynamic tracking cancer therapy and DNA damage/repair analysis

    NASA Astrophysics Data System (ADS)

    Uesaka, M.; Demachi, K.; Fujiwara, T.; Dobashi, K.; Fujisawa, H.; Chhatkuli, R. B.; Tsuda, A.; Tanaka, S.; Matsumura, Y.; Otsuki, S.; Kusano, J.; Yamamoto, M.; Nakamura, N.; Tanabe, E.; Koyama, K.; Yoshida, M.; Fujimori, R.; Yasui, A.

    2015-06-01

    We are developing compact electron linear accelerators (hereafter linac) with high RF (Radio Frequency) frequency (9.3 GHz, wavelength 32.3 mm) of X-band and applying to medicine and non-destructive testing. Especially, potable 950 keV and 3.95 MeV linac X-ray sources have been developed for on-site transmission testing at several industrial plants and civil infrastructures including bridges. 6 MeV linac have been made for pinpoint X-ray dynamic tracking cancer therapy. The length of the accelerating tube is ∼600 mm. The electron beam size at the X-ray target is less than 1 mm and X-ray spot size at the cancer is less than 3 mm. Several hardware and software are under construction for dynamic tracking therapy for moving lung cancer. Moreover, as an ultimate compact linac, we are designing and manufacturing a laser dielectric linac of ∼1 MeV with Yr fiber laser (283 THz, wavelength 1.06 pm). Since the wavelength is 1.06 μm, the length of one accelerating strcture is tens pm and the electron beam size is in sub-micro meter. Since the sizes of cell and nuclear are about 10 and 1 μm, respectively, we plan to use this “On-chip” linac for radiation-induced DNA damage/repair analysis. We are thinking a system where DNA in a nucleus of cell is hit by ∼1 μm electron or X-ray beam and observe its repair by proteins and enzymes in live cells in-situ.

  11. Biological therapies in nonsmall cell lung cancer.

    PubMed

    Zugazagoitia, Jon; Molina-Pinelo, Sonia; Lopez-Rios, Fernando; Paz-Ares, Luis

    2017-03-01

    Biological therapies have improved survival outcomes of advanced-stage nonsmall cell lung cancer (NSCLC). Genotype-directed therapies have changed treatment paradigms of patients with EGFR-mutant and ALK/ROS1-rearranged lung adenocarcinomas, and the list of druggable targets with demonstrated clinical actionability (BRAF, MET, RET, NTRK1 and HER2) continues to expand. Furthermore, we have incrementally understood the mechanisms of cancer immune evasion and foresee ways to effectively circumvent them, particularly at the immune checkpoint level. Drugs targeting the tumour immune-evasive PD-1 pathway have demonstrated remarkable treatment benefits in this disease, with a non-negligible fraction of patients potentially receiving long-term survival benefits. Herein, we briefly discuss the role of various medical disciplines in the management of advanced-stage NSCLC and review the most relevant biological therapies for this disease, with particular emphasis in genotype-directed therapies and immune checkpoint inhibitors.

  12. Stem cell biology and cell transplantation therapy in the retina.

    PubMed

    Osakada, Fumitaka; Hirami, Yasuhiko; Takahashi, Masayo

    2010-01-01

    Embryonic stem (ES) cells, which are derived from the inner cell mass of mammalian blastocyst stage embryos, have the ability to differentiate into any cell type in the body and to grow indefinitely while maintaining pluripotency. During development, cells undergo progressive and irreversible differentiation into specialized adult cell types. Remarkably, in spite of this restriction in potential, adult somatic cells can be reprogrammed and returned to the naive state of pluripotency found in the early embryo simply by forcing expression of a defined set of transcription factors. These induced pluripotent stem (iPS) cells are molecularly and functionally equivalent to ES cells and provide powerful in vitro models for development, disease, and drug screening, as well as material for cell replacement therapy. Since functional impairment results from cell loss in most central nervous system (CNS) diseases, recovery of lost cells is an important treatment strategy. Although adult neurogenesis occurs in restricted regions, the CNS has poor potential for regeneration to compensate for cell loss. Thus, cell transplantation into damaged or diseased CNS tissues is a promising approach to treating various neurodegenerative disorders. Transplantation of photoreceptors or retinal pigment epithelium cells derived from human ES cells can restore some visual function. Patient-specific iPS cells may lead to customized cell therapy. However, regeneration of retinal function will require a detailed understanding of eye development, visual system circuitry, and retinal degeneration pathology. Here, we review the current progress in retinal regeneration, focusing on the therapeutic potential of pluripotent stem cells.

  13. Stem cell therapy: facts and fiction.

    PubMed

    Spits, C

    2012-01-01

    This opinion paper is a brief overview of the current state of the translation of stem cell therapy from the bench to the clinic. The hype generated by the great medical potential of stem cells has lead to hundreds of clinics worldwide claiming to have the cure for every imaginable condition. This fraudulent practice is far from the reality of scientists and bona fide companies. Much effort is put into addressing all the hurdles we have been encountering for the safe use of stem cells in therapy. By now, a significant number of clinical trials are booking very exciting progress, opening a realistic path to the use of these amazing cells in regenerative medicine.

  14. Stem cell therapy for diabetes mellitus

    PubMed Central

    Voltarelli, Júlio C; Couri, Carlos E B; Oliveira, Maria C; Moraes, Daniela A; Stracieri, Ana B P L; Pieroni, Fabiano; Barros, George M N; Malmegrim, Kelen C R; Simões, Belinda P; Leal, Angela M O; Foss, Milton C

    2011-01-01

    In this review, we present (1) a brief discussion of hematopoietic stem cell transplantation (HSCT) for severe and refractory autoimmune diseases (AIDs) from its beginning in 1996 through recently initiated prospective randomized clinical trials; (2) an update (up to July 2009) of clinical and laboratory outcomes of 23 patients with newly diagnosed type 1 diabetes mellitus (T1DM), who underwent autologous HSCT at the Bone Marrow Transplantation Unit of the Ribeirão Preto Medical School, University of São Paulo, Brazil; (3) a discussion of possible mechanisms of action of HSCT in AIDs, including preliminary laboratory data obtained from our patients; and (4) a discussion of future perspectives of stem cell therapy for T1DM and type 2 DM, including the use of stem cell sources other than adult bone marrow and the combination of cell therapy with regenerative compounds. PMID:25018908

  15. How we make cell therapy in Italy

    PubMed Central

    Montemurro, Tiziana; Viganò, Mariele; Budelli, Silvia; Montelatici, Elisa; Lavazza, Cristiana; Marino, Luigi; Parazzi, Valentina; Lazzari, Lorenza; Giordano, Rosaria

    2015-01-01

    In the 21st century scenario, new therapeutic tools are needed to take up the social and medical challenge posed by the more and more frequent degenerative disorders and by the aging of population. The recent category of advanced therapy medicinal products has been created to comprise cellular, gene therapy, and tissue engineered products, as a new class of drugs. Their manufacture requires the same pharmaceutical framework as for conventional drugs and this means that industrial, large-scale manufacturing process has to be adapted to the peculiar characteristics of cell-containing products. Our hospital took up the challenge of this new path in the early 2000s; and herein we describe the approach we followed to set up a pharmaceutical-grade facility in a public hospital context, with the aim to share the solutions we found to make cell therapy compliant with the requirements for the production and the quality control of a high-standard medicinal product. PMID:26316716

  16. Enhanced Genotoxicity of Silver Nanoparticles in DNA Repair Deficient Mammalian Cells

    PubMed Central

    Lim, Hui Kheng; Asharani, P. V.; Hande, M. Prakash

    2012-01-01

    Silver nanoparticles (Ag-np) have been used in medicine and commercially due to their anti-microbial properties. Therapeutic potentials of these nanoparticles are being explored extensively despite the lack of information on their mechanism of action at molecular and cellular level. Here, we have investigated the DNA damage response and repair following Ag-np treatment in mammalian cells. Studies have shown that Ag-np exerts genotoxicity through double-strand breaks (DSBs). DNA-PKcs, the catalytic subunit of DNA dependent protein kinase, is an important caretaker of the genome which is known to be the main player mediating Non-homologous End-Joining (NHEJ) repair pathway. We hypothesize that DNA-PKcs is responsible for the repair of Ag-np induced DNA damage. In vitro studies have been carried out to investigate both cytotoxicity and genotoxicity induced by Ag-np in normal human cells, DNA-PKcs proficient, and deficient mammalian cells. Chemical inhibition of DNA-PKcs activity with NU7026, an ATP-competitive inhibitor of DNA-PKcs, has been performed to further validate the role of DNA-PKcs in this model. Our results suggest that Ag-np induced more prominent dose-dependent decrease in cell viability in DNA-PKcs deficient or inhibited cells. The deficiency or inhibition of DNA-PKcs renders the cells with higher susceptibility to DNA damage and genome instability which in turn contributed to greater cell cycle arrest/cell death. These findings support the fact that DNA-PKcs is involved in the repair of Ag-np induced genotoxicity and NHEJ repair pathway and DNA-PKcs particularly is activated to safeguard the genome upon Ag-np exposure. PMID:22707954

  17. Enhanced genotoxicity of silver nanoparticles in DNA repair deficient Mammalian cells.

    PubMed

    Lim, Hui Kheng; Asharani, P V; Hande, M Prakash

    2012-01-01

    Silver nanoparticles (Ag-np) have been used in medicine and commercially due to their anti-microbial properties. Therapeutic potentials of these nanoparticles are being explored extensively despite the lack of information on their mechanism of action at molecular and cellular level. Here, we have investigated the DNA damage response and repair following Ag-np treatment in mammalian cells. Studies have shown that Ag-np exerts genotoxicity through double-strand breaks (DSBs). DNA-PKcs, the catalytic subunit of DNA dependent protein kinase, is an important caretaker of the genome which is known to be the main player mediating Non-homologous End-Joining (NHEJ) repair pathway. We hypothesize that DNA-PKcs is responsible for the repair of Ag-np induced DNA damage. In vitro studies have been carried out to investigate both cytotoxicity and genotoxicity induced by Ag-np in normal human cells, DNA-PKcs proficient, and deficient mammalian cells. Chemical inhibition of DNA-PKcs activity with NU7026, an ATP-competitive inhibitor of DNA-PKcs, has been performed to further validate the role of DNA-PKcs in this model. Our results suggest that Ag-np induced more prominent dose-dependent decrease in cell viability in DNA-PKcs deficient or inhibited cells. The deficiency or inhibition of DNA-PKcs renders the cells with higher susceptibility to DNA damage and genome instability which in turn contributed to greater cell cycle arrest/cell death. These findings support the fact that DNA-PKcs is involved in the repair of Ag-np induced genotoxicity and NHEJ repair pathway and DNA-PKcs particularly is activated to safeguard the genome upon Ag-np exposure.

  18. Progressive Muscle Cell Delivery as a Solution for Volumetric Muscle Defect Repair

    PubMed Central

    Kim, Ji Hyun; Ko, In Kap; Atala, Anthony; Yoo, James J.

    2016-01-01

    Reconstructing functional volumetric tissue in vivo following implantation remains a critical challenge facing cell-based approaches. Several pre-vascularization approaches have been developed to increase cell viability following implantation. Structural and functional restoration was achieved in a preclinical rodent tissue defect; however, the approach used in this model fails to repair larger (>mm) defects as observed in a clinical setting. We propose an effective cell delivery system utilizing appropriate vascularization at the site of cell implantation that results in volumetric and functional tissue reconstruction. Our method of multiple cell injections in a progressive manner yielded improved cell survival and formed volumetric muscle tissues in an ectopic muscle site. In addition, this strategy supported the reconstruction of functional skeletal muscle tissue in a rodent volumetric muscle loss injury model. Results from our study suggest that our method may be used to repair volumetric tissue defects by overcoming diffusion limitations and facilitating adequate vascularization. PMID:27924941

  19. Presentation of a novel model of chitosan- polyethylene oxide-nanohydroxyapatite nanofibers together with bone marrow stromal cells to repair and improve minor bone defects

    PubMed Central

    Emamgholi, Asgar; Rahimi, Mohsen; Kaka, Gholamreza; Sadraie, Seyed Homayoon; Najafi, Saleh

    2015-01-01

    Objective(s): Various methods for repairing bone defects are presented. Cell therapy is one of these methods. Bone marrow stromal cells (BMSCs) seem to be suitable for this purpose. On the other hand, lots of biomaterials are used to improve and repair the defect in the body, so in this study we tried to produce a similar structure to the bone by the chitosan and hydroxyapatite. Materials and Methods: In this study, the solution of chitosan-nanohydroxyapatite-polyethylene oxide (PEO) Nanofibers was produced by electrospinning method, and then the BMSCs were cultured on this solution. A piece of chitosan-nanohydroxyapatite Nanofibers with BMSCs was placed in a hole with the diameter of 1 mm at the distal epiphysis of the rat femur. Then the biomechanical and radiographic studies were performed. Results: Biomechanical testing results showed that bone strength was significantly higher in the Nanofiber/BMSCs group in comparison with control group. Also the bone strength in nanofiber/BMSCs group was significant, but in nanofiber group was nearly significant. Radiographic studies also showed that the average amount of callus formation (radio opacity) in nanofiber and control group was not significantly different. The callus formation in nanofiber/BMSCs group was increased compared to the control group, and it was not significant in the nanofiber group. Conclusion: Since chitosan-nanohydroxyapatite nanofibers with BMSCs increases the rate of bone repair, the obtained cell-nanoscaffold shell can be used in tissue engineering and cell therapy, especially for bone defects. PMID:26523221

  20. Human amniotic epithelial cells combined with silk fibroin scaffold in the repair of spinal cord injury

    PubMed Central

    Wang, Ting-gang; Xu, Jie; Zhu, Ai-hua; Lu, Hua; Miao, Zong-ning; Zhao, Peng; Hui, Guo-zhen; Wu, Wei-jiang

    2016-01-01

    Treatment and functional reconstruction after central nervous system injury is a major medical and social challenge. An increasing number of researchers are attempting to use neural stem cells combined with artificial scaffold materials, such as fibroin, for nerve repair. However, such approaches are challenged by ethical and practical issues. Amniotic tissue, a clinical waste product, is abundant, and amniotic epithelial cells are pluripotent, have low immunogenicity, and are not the subject of ethical debate. We hypothesized that amniotic epithelial cells combined with silk fibroin scaffolds would be conducive to the repair of spinal cord injury. To test this, we isolated and cultured amniotic epithelial cells, and constructed complexes of these cells and silk fibroin scaffolds. Implantation of the cell-scaffold complex into a rat model of spinal cord injury resulted in a smaller glial scar in the damaged cord tissue than in model rats that received a blank scaffold, or amniotic epithelial cells alone. In addition to a milder local immunological reaction, the rats showed less inflammatory cell infiltration at the transplant site, milder host-versus-graft reaction, and a marked improvement in motor function. These findings confirm that the transplantation of amniotic epithelial cells combined with silk fibroin scaffold can promote the repair of spinal cord injury. Silk fibroin scaffold can provide a good nerve regeneration microenvironment for amniotic epithelial cells. PMID:27904501

  1. New Advanced Technologies in Stem Cell Therapy

    DTIC Science & Technology

    2014-11-01

    Pittsburgh, PA, USA. 8Stem Cell and Regenerative Medicine Center, Cellular and Molecular Arrhythmia Research Program, Department of Medicine, School...function and reduce ventricular arrhythmias (145). Preclinical studies are beginning to test PSC cell therapy in large-animal models of heart dis- ease...been ob- served (148). However, a transient increase in ventricular arrhythmias has occurred, raising a potential safety concern. Transplantation of hu

  2. [Research for cell therapy by induced pluripotent stem cell].

    PubMed

    Sakurai, Hidetoshi; Yamanaka, Shinya

    2011-12-01

    Induced pluripotent stem (iPS) cells, which are generated from somatic cells, are expected to be a hopeful source for cell therapy to treat intractable diseases due to its unlimited proliferation potential, differentiation potentials and the capability of autotransplantation characteristics. In this review, we have summarized the extension of iPS cell researches into cell therapy and the new researches associated with iPS cell technology. However, transplantation of iPS cell-derived tissue is considered to have a risk of tumorigenesis which is one of the major hurdles of using pluripotent stem cell in clinical application. This review is also focused on new strategies for reducing a risk of tumorigenesis.

  3. Identification of Drugs that Regulate Dermal Stem Cells and Enhance Skin Repair.

    PubMed

    Naska, Sibel; Yuzwa, Scott A; Johnston, Adam P W; Paul, Smitha; Smith, Kristen M; Paris, Maryline; Sefton, Michael V; Datti, Alessandro; Miller, Freda D; Kaplan, David R

    2016-01-12

    Here, we asked whether we could identify pharmacological agents that enhance endogenous stem cell function to promote skin repair, focusing on skin-derived precursors (SKPs), a dermal precursor cell population. Libraries of compounds already used in humans were screened for their ability to enhance the self-renewal of human and rodent SKPs. We identified and validated five such compounds, and showed that two of them, alprostadil and trimebutine maleate, enhanced the repair of full thickness skin wounds in middle-aged mice. Moreover, SKPs isolated from drug-treated skin displayed long-term increases in self-renewal when cultured in basal growth medium without drugs. Both alprostadil and trimebutine maleate likely mediated increases in SKP self-renewal by moderate hyperactivation of the MEK-ERK pathway. These findings identify candidates for potential clinical use in human skin repair, and provide support for the idea that pharmacological activation of endogenous tissue precursors represents a viable therapeutic strategy.

  4. Cellular therapy for sickle cell disease.

    PubMed

    Abraham, Allistair; Jacobsohn, David A; Bollard, Catherine M

    2016-11-01

    Sickle cell disease (SCD) is a monogenic red cell disorder affecting more than 300 000 annual births worldwide and leading to significant organ toxicity and premature mortality. Although chronic therapies such as hydroxyurea have improved outcomes, more durable therapeutic and curative options are still being investigated. Newer understanding of the disease has implicated invariant natural killer T cells as a critical immune profile that potentiates SCD. Hence, targeting this cell population may offer a new approach to disease management. Hematopoietic stem cell transplant is a curative option for patients with SCD, but the under-representation of minorities on the unrelated donor registry means that this is not a feasible option for more than 75% of patients. Work in this area has therefore focused on increasing the donor pool and decreasing transplant-related toxicities to make this a treatment option for the majority of patients with SCD. This review focuses on the currently available cell and gene therapies for patients with SCD and acknowledges that newer gene-editing approaches to improve gene therapy efficiency and safety are the next wave of potentially curative approaches.

  5. Stem cell route to neuromuscular therapies.

    PubMed

    Partridge, Terence A

    2003-02-01

    As applied to skeletal muscle, stem cell therapy is a reincarnation of myoblast transfer therapy that has resulted from recent advances in the cell biology of skeletal muscle. Both strategies envisage the reconstruction of damaged muscle from its precursors, but stem cell therapy employs precursors that are earlier in the developmental hierarchy. It is founded on demonstrations of apparently multipotential cells in a wide variety of tissues that can assume, among others, a myogenic phenotype. The main demonstrated advantage of such cells is that they are capable of colonizing many tissues, including skeletal and cardiac muscle via the blood vascular system, thereby providing the potential for a body-wide distribution of myogenic progenitors. From a practical viewpoint, the chief disadvantage is that such colonization has been many orders of magnitude too inefficient to be useful. Proposals for overcoming this drawback are the subject of much speculation but, so far, relatively little experimentation. This review attempts to give some perspective to the status of the stem cell as a therapeutic instrument for neuromuscular disease and to identify issues that need to be addressed for application of this technology.

  6. Stem cell therapy in the management of shoulder rotator cuff disorders.

    PubMed

    Valencia Mora, Maria; Ruiz Ibán, Miguel A; Díaz Heredia, Jorge; Barco Laakso, Raul; Cuéllar, Ricardo; García Arranz, Mariano

    2015-05-26

    Rotator cuff tears are frequent shoulder problems that are usually dealt with surgical repair. Despite improved surgical techniques, the tendon-to-bone healing rate is unsatisfactory due to difficulties in restoring the delicate transitional tissue between bone and tendon. It is essential to understand the molecular mechanisms that determine this failure. The study of the molecular environment during embryogenesis and during normal healing after injury is key in devising strategies to get a successful repair. Mesenchymal stem cells (MSC) can differentiate into different mesodermal tissues and have a strong paracrine, anti-inflammatory, immunoregulatory and angiogenic potential. Stem cell therapy is thus a potentially effective therapy to enhance rotator cuff healing. Promising results have been reported with the use of autologous MSC of different origins in animal studies: they have shown to have better healing properties, increasing the amount of fibrocartilage formation and improving the orientation of fibrocartilage fibers with less immunologic response and reduced lymphocyte infiltration. All these changes lead to an increase in biomechanical strength. However, animal research is still inconclusive and more experimental studies are needed before human application. Future directions include expanded stem cell therapy in combination with growth factors or different scaffolds as well as new stem cell types and gene therapy.

  7. Stem cell therapy in the management of shoulder rotator cuff disorders

    PubMed Central

    Mora, Maria Valencia; Ibán, Miguel A Ruiz; Heredia, Jorge Díaz; Laakso, Raul Barco; Cuéllar, Ricardo; Arranz, Mariano García

    2015-01-01

    Rotator cuff tears are frequent shoulder problems that are usually dealt with surgical repair. Despite improved surgical techniques, the tendon-to-bone healing rate is unsatisfactory due to difficulties in restoring the delicate transitional tissue between bone and tendon. It is essential to understand the molecular mechanisms that determine this failure. The study of the molecular environment during embryogenesis and during normal healing after injury is key in devising strategies to get a successful repair. Mesenchymal stem cells (MSC) can differentiate into different mesodermal tissues and have a strong paracrine, anti-inflammatory, immunoregulatory and angiogenic potential. Stem cell therapy is thus a potentially effective therapy to enhance rotator cuff healing. Promising results have been reported with the use of autologous MSC of different origins in animal studies: they have shown to have better healing properties, increasing the amount of fibrocartilage formation and improving the orientation of fibrocartilage fibers with less immunologic response and reduced lymphocyte infiltration. All these changes lead to an increase in biomechanical strength. However, animal research is still inconclusive and more experimental studies are needed before human application. Future directions include expanded stem cell therapy in combination with growth factors or different scaffolds as well as new stem cell types and gene therapy. PMID:26029341

  8. The cell-cycle checkpoint kinase Chk1 is required for mammalian homologous recombination repair.

    PubMed

    Sørensen, Claus Storgaard; Hansen, Lasse Tengbjerg; Dziegielewski, Jaroslaw; Syljuåsen, Randi G; Lundin, Cecilia; Bartek, Jiri; Helleday, Thomas

    2005-02-01

    The essential checkpoint kinase Chk1 is required for cell-cycle delays after DNA damage or blocked DNA replication. However, it is unclear whether Chk1 is involved in the repair of damaged DNA. Here we establish that Chk1 is a key regulator of genome maintenance by the homologous recombination repair (HRR) system. Abrogation of Chk1 function with small interfering RNA or chemical antagonists inhibits HRR, leading to persistent unrepaired DNA double-strand breaks (DSBs) and cell death after replication inhibition with hydroxyurea or DNA-damage caused by camptothecin. After hydroxyurea treatment, the essential recombination repair protein RAD51 is recruited to DNA repair foci performing a vital role in correct HRR. We demonstrate that Chk1 interacts with RAD51, and that RAD51 is phosphorylated on Thr 309 in a Chk1-dependent manner. Consistent with a functional interplay between Chk1 and RAD51, Chk1-depleted cells failed to form RAD51 nuclear foci after exposure to hydroxyurea, and cells expressing a phosphorylation-deficient mutant RAD51(T309A) were hypersensitive to hydroxyurea. These results highlight a crucial role for the Chk1 signalling pathway in protecting cells against lethal DNA lesions through regulation of HRR.

  9. Stem Cell Therapies in Retinal Disorders

    PubMed Central

    Garg, Aakriti; Yang, Jin; Lee, Winston; Tsang, Stephen H.

    2017-01-01

    Stem cell therapy has long been considered a promising mode of treatment for retinal conditions. While human embryonic stem cells (ESCs) have provided the precedent for regenerative medicine, the development of induced pluripotent stem cells (iPSCs) revolutionized this field. iPSCs allow for the development of many types of retinal cells, including those of the retinal pigment epithelium, photoreceptors, and ganglion cells, and can model polygenic diseases such as age-related macular degeneration. Cellular programming and reprogramming technology is especially useful in retinal diseases, as it allows for the study of living cells that have genetic variants that are specific to patients’ diseases. Since iPSCs are a self-renewing resource, scientists can experiment with an unlimited number of pluripotent cells to perfect the process of targeted differentiation, transplantation, and more, for personalized medicine. Challenges in the use of stem cells are present from the scientific, ethical, and political realms. These include transplant complications leading to anatomically incorrect placement, concern for tumorigenesis, and incomplete targeting of differentiation leading to contamination by different types of cells. Despite these limitations, human ESCs and iPSCs specific to individual patients can revolutionize the study of retinal disease and may be effective therapies for conditions currently considered incurable. PMID:28157165

  10. Stem cells engineering for cell-based therapy.

    PubMed

    Taupin, Philippe

    2007-09-01

    Stem cells carry the promise to cure a broad range of diseases and injuries, from diabetes, heart and muscular diseases, to neurological diseases, disorders and injuries. Significant progresses have been made in stem cell research over the past decade; the derivation of embryonic stem cells (ESCs) from human tissues, the development of cloning technology by somatic cell nuclear transfer (SCNT) and the confirmation that neurogenesis occurs in the adult mammalian brain and that neural stem cells (NSCs) reside in the adult central nervous system (CNS), including that of humans. Despite these advances, there may be decades before stem cell research will translate into therapy. Stem cell research is also subject to ethical and political debates, controversies and legislation, which slow its progress. Cell engineering has proven successful in bringing genetic research to therapy. In this review, I will review, in two examples, how investigators are applying cell engineering to stem cell biology to circumvent stem cells' ethical and political constraints and bolster stem cell research and therapy.

  11. TOPICAL REVIEW: Stem cells engineering for cell-based therapy

    NASA Astrophysics Data System (ADS)

    Taupin, Philippe

    2007-09-01

    Stem cells carry the promise to cure a broad range of diseases and injuries, from diabetes, heart and muscular diseases, to neurological diseases, disorders and injuries. Significant progresses have been made in stem cell research over the past decade; the derivation of embryonic stem cells (ESCs) from human tissues, the development of cloning technology by somatic cell nuclear transfer (SCNT) and the confirmation that neurogenesis occurs in the adult mammalian brain and that neural stem cells (NSCs) reside in the adult central nervous system (CNS), including that of humans. Despite these advances, there may be decades before stem cell research will translate into therapy. Stem cell research is also subject to ethical and political debates, controversies and legislation, which slow its progress. Cell engineering has proven successful in bringing genetic research to therapy. In this review, I will review, in two examples, how investigators are applying cell engineering to stem cell biology to circumvent stem cells' ethical and political constraints and bolster stem cell research and therapy.

  12. Transplantation of bone marrow derived cells promotes pancreatic islet repair in diabetic mice

    SciTech Connect

    Gao Xiaodong; Song Lujun; Shen Kuntang; Wang Hongshan; Niu Weixin Qin Xinyu

    2008-06-20

    The transplantation of bone marrow (BM) derived cells to initiate pancreatic regeneration is an attractive but as-yet unrealized strategy. Presently, BM derived cells from green fluorescent protein transgenic mice were transplanted into diabetic mice. Repair of diabetic islets was evidenced by reduction of hyperglycemia, increase in number of islets, and altered pancreatic histology. Cells in the pancreata of recipient mice co-expressed BrdU and insulin. Double staining revealed {beta} cells were in the process of proliferation. BrdU{sup +} insulin{sup -} PDX-1{sup +} cells, Ngn3{sup +} cells and insulin{sup +} glucagon{sup +} cells, which showed stem cells, were also found during {beta}-cell regeneration. The majority of transplanted cells were mobilized to the islet and ductal regions. In recipient pancreas, transplanted cells simultaneously expressed CD34 but did not express insulin, PDX-1, Ngn3, Nkx2.2, Nkx6.1, Pax4, Pax6, and CD45. It is concluded that BM derived cells especially CD34{sup +} cells can promote repair of pancreatic islets. Moreover, both proliferation of {beta} cells and differentiation of pancreatic stem cells contribute to the regeneration of {beta} cells.

  13. Transplantation of bone marrow derived cells promotes pancreatic islet repair in diabetic mice.

    PubMed

    Gao, Xiaodong; Song, Lujun; Shen, Kuntang; Wang, Hongshan; Niu, Weixin; Qin, Xinyu

    2008-06-20

    The transplantation of bone marrow (BM) derived cells to initiate pancreatic regeneration is an attractive but as-yet unrealized strategy. Presently, BM derived cells from green fluorescent protein transgenic mice were transplanted into diabetic mice. Repair of diabetic islets was evidenced by reduction of hyperglycemia, increase in number of islets, and altered pancreatic histology. Cells in the pancreata of recipient mice co-expressed BrdU and insulin. Double staining revealed beta cells were in the process of proliferation. BrdU(+) insulin(-) PDX-1(+) cells, Ngn3(+) cells and insulin(+) glucagon(+) cells, which showed stem cells, were also found during beta-cell regeneration. The majority of transplanted cells were mobilized to the islet and ductal regions. In recipient pancreas, transplanted cells simultaneously expressed CD34 but did not express insulin, PDX-1, Ngn3, Nkx2.2, Nkx6.1, Pax4, Pax6, and CD45. It is concluded that BM derived cells especially CD34(+) cells can promote repair of pancreatic islets. Moreover, both proliferation of beta cells and differentiation of pancreatic stem cells contribute to the regeneration of beta cells.

  14. Normal and defective repair of damaged DNA in human cells: a sensitive assay utilizing the photolysis of bromodeoxyuridine.

    PubMed

    Regan, J D; Setlow, R B; Ley, R D

    1971-04-01

    A new technique has been developed for studying the extent of repair of UV-radiation damage to DNA in human cells. It is easy to use, has excellent sensitivity, and provides rapid quantitative estimates of repair. UV-irradiated cells whose DNA has been previously labeled with a radioisotope are grown after irradiation in non-radioactive bromodeoxyuridine, which is incorporated at the breaks induced by repair enzymes. After a period of growth in the thymidine analog the cells are exposed to a large flux of 313 nm radiation and then lysed on top of an alkaline sucrose gradient. Bromodeoxyuridine-containing sections of the DNA are thus selectively photolysed. Sedimentation in the alkaline gradient reveals the average molecular weight of disrupted segments and gives a measure of the number of breaks induced by repair enzymes over the whole period allowed for repair. The large change in average molecular weight observed upon exposure of normal repairing cells to 313 nm radiation is not observed in the repair-deficient cells from patients with xeroderma pigmentosum. The quantitative aspects of this assay for repair and its sensitivity should make it applicable to the study of repair induced by agents other than UV radiation.

  15. Effect of polyamine depletion on DNA damage and repair following UV irradiation of HeLa cells.

    PubMed

    Snyder, R D; Sunkara, P S

    1990-09-01

    Treatment of HeLa cells with the polyamine biosynthesis inhibitors, methylglyoxal bis(guanylhydrazone) (MGBG), difluoromethylornithine (DFMO) or a combination of the two, resulted in reduction in cellular polyamine levels. Analysis of UV light-induced DNA damage and repair in these polyamine depleted cells revealed distinct differences in the repair process relative to that seen in cells possessing a normal polyamine complement. Initial yield of thymine dimers and rate of removal of these lesions from cellular DNA appeared normal in polyamine-depleted cells. However, depleted cells exhibited retarded sealing of DNA strand breaks resulting from cellular repair processes, reduced repair synthesis and an increased sensitivity to UV killing. Incision at damaged sites was not affected since ara-C repair-dependent breaks accumulated in a normal fashion. Molecular analysis of inhibited repair sites by exonuclease III and T4 DNA ligase probes suggest that the strand interruptions consist of gaps rather than ligatable nicks, consistent with an interpretation of the repair defect being at the gap-filling stage rather than the ligation step. Observed patterns of differential polyamine depletion by DFMO and MGBG, and partial reversal of repair inhibition by polyamine supplementation, suggests that polyamine depletion per se, rather than some secondary effect of inhibitor treatment, is responsible for the inhibition of repair.

  16. [SOS response of DNA repair and genetic cell instability under hypoxic conditions].

    PubMed

    Vasil'eva, S V; Strel'tsova, D A

    2011-01-01

    The SOS DNA repair pathway is induced in E. coli as a multifunctional cell response to a wide variety of signals: UV, X or gamma-irradiation, mitomycin C or nalidixic acid treatment, thymine starvation, etc. Triggering of the system can be used as a general and early sign of DNA damage. Additionally, the SOS-response is known to be an "error-prone" DNA repair pathway and one of the sources of genetic instability. Hypoxic conditions are established to be the major factor of genetic instability as well. In this paper we for the first time studied the SOS DNA repair response under hypoxic conditions induced by the well known aerobic SOS-inducers. The SOS DNA repair response was examined as a reaction of E. coli PQ37 [sfiA::lacZ] cells to UVC, NO-donating agents and 4NQO. Here we provide evidence that those agents were able to induce the SOS DNA repair response in E. coli at anaerobic growth conditions. The process does not depend on the transcriptional activity of the universal protein of E. col anaerobic growth Fnr [4Fe-4S]2+ or can not be referred to as an indicator of genetic instability in hypoxic conditions.

  17. Kin17 facilitates multiple double-strand break repair pathways that govern B cell class switching

    PubMed Central

    Le, Michael X.; Haddad, Dania; Ling, Alexanda K.; Li, Conglei; So, Clare C.; Chopra, Amit; Hu, Rui; Angulo, Jaime F.; Moffat, Jason; Martin, Alberto

    2016-01-01

    Class switch recombination (CSR) in B cells requires the timely repair of DNA double-stranded breaks (DSBs) that result from lesions produced by activation-induced cytidine deaminase (AID). Through a genome-wide RNAi screen, we identified Kin17 as a gene potentially involved in the maintenance of CSR in murine B cells. In this study, we confirm a critical role for Kin17 in CSR independent of AID activity. Furthermore, we make evident that DSBs generated by AID or ionizing radiation require Kin17 for efficient repair and resolution. Our report shows that reduced Kin17 results in an elevated deletion frequency following AID mutational activity in the switch region. In addition, deficiency in Kin17 affects the functionality of multiple DSB repair pathways, namely homologous recombination, non-homologous end-joining, and alternative end-joining. This report demonstrates the importance of Kin17 as a critical factor that acts prior to the repair phase of DSB repair and is of bona fide importance for CSR. PMID:27853268

  18. Cancer stem cells, cancer cell plasticity and radiation therapy.

    PubMed

    Vlashi, Erina; Pajonk, Frank

    2015-04-01

    Since the first prospective identification of cancer stem cells in solid cancers the cancer stem cell hypothesis has reemerged as a research topic of increasing interest. It postulates that solid cancers are organized hierarchically with a small number of cancer stem cells driving tumor growth, repopulation after injury and metastasis. They give rise to differentiated progeny, which lack these features. The model predicts that for any therapy to provide cure, all cancer stem cells have to be eliminated while the survival of differentiated progeny is less critical. In this review we discuss recent reports challenging the idea of a unidirectional differentiation of cancer cells. These reports provide evidence supporting the idea that non-stem cancer cells exhibit a remarkable degree of plasticity that allows them to re-acquire cancer stem cell traits, especially in the context of radiation therapy. We summarize conditions under which differentiation is reversed and discuss the current knowledge of the underlying mechanisms.

  19. Evaluation of dental pulp repair using low level laser therapy (688 nm and 785 nm) morphologic study in capuchin monkeys

    NASA Astrophysics Data System (ADS)

    Pretel, H.; Oliveira, J. A.; Lizarelli, R. F. Z.; Ramalho, L. T. O.

    2009-02-01

    The aim of this study was to evaluate the hypothesis that low-level laser therapy (LLLT) 688 nm and 785 nm accelerate dentin barrier formation and repair process after traumatic pulp exposure. The sample consisted of 45 premolars of capuchin monkeys (Cebus apella) with pulp exposure Class V cavities. All premolars were treated with calcium hydroxide (Ca(OH)2), divided in groups of 15 teeth each, and analyzed on 7th, 25th, and 60th day. Group GI - only Ca(OH)2, GII - laser 688 nm, and GIII - laser 785 nm. Laser beam was used in single and punctual dose with the parameters: continuous, 688 nm and 785 nm wavelength, tip's area of 0.00785 cm2, power 50 mW, application time 20 s, dose 255 J/cm2, energy 2 J. Teeth were capped with Ca(OH)2, Ca(OH)2 cement and restored with amalgam. All groups presented pulp repair. On 25th day the thickness of the formed dentin barrier was different between the groups GI and GII (p < 0.05) and between groups GI and GIII (p < 0.01). On 60th day there was difference between GI and GIII (p < 0.01). It may be concluded that, LLLT 688 nm and 785 nm accelerated dentin barrier formation and consequently pulp repair process, with best results using infrared laser 785 nm.

  20. Stem Cells, Cell Therapies, and Bioengineering in Lung Biology and Diseases. Comprehensive Review of the Recent Literature 2010–2012

    PubMed Central

    2013-01-01

    A conference, “Stem Cells and Cell Therapies in Lung Biology and Lung Diseases,” was held July 25 to 28, 2011 at the University of Vermont to review the current understanding of the role of stem and progenitor cells in lung repair after injury and to review the current status of cell therapy and ex vivo bioengineering approaches for lung diseases. These are rapidly expanding areas of study that provide further insight into and challenge traditional views of mechanisms of lung repair after injury and pathogenesis of several lung diseases. The goals of the conference were to summarize the current state of the field, to discuss and debate current controversies, and to identify future research directions and opportunities for basic and translational research in cell-based therapies for lung diseases. The goal of this article, which accompanies the formal conference report, is to provide a comprehensive review of the published literature in lung regenerative medicine from the last conference report through December 2012. PMID:23869446

  1. Cell therapy worldwide: an incipient revolution.

    PubMed

    Rao, Mahendra; Mason, Chris; Solomon, Susan

    2015-01-01

    The regenerative medicine field is large, diverse and active worldwide. A variety of different organizational and product models have been successful, and pioneering entrepreneurs have shown both what can work and, critically, what does not. Evolving regulations, novel funding mechanisms combined with new technological breakthroughs are keeping the field in a state of flux. The field struggles to cope with the lack of infrastructure and investment, it nevertheless has evolved from its roots in human stem cell therapy and tissue and organ transplants to a field composed of a variety of products from multiple cell sources with approval for use in numerous countries. Currently, tens of thousands of patients have been treated with some kind of cell therapy.

  2. Genetic engineering of mesenchymal stem cells and its application in human disease therapy.

    PubMed

    Hodgkinson, Conrad P; Gomez, José A; Mirotsou, Maria; Dzau, Victor J

    2010-11-01

    The use of stem cells for tissue regeneration and repair is advancing both at the bench and bedside. Stem cells isolated from bone marrow are currently being tested for their therapeutic potential in a variety of clinical conditions including cardiovascular injury, kidney failure, cancer, and neurological and bone disorders. Despite the advantages, stem cell therapy is still limited by low survival, engraftment, and homing to damage area as well as inefficiencies in differentiating into fully functional tissues. Genetic engineering of mesenchymal stem cells is being explored as a means to circumvent some of these problems. This review presents the current understanding of the use of genetically engineered mesenchymal stem cells in human disease therapy with emphasis on genetic modifications aimed to improve survival, homing, angiogenesis, and heart function after myocardial infarction. Advancements in other disease areas are also discussed.

  3. Recent Progress in Endothelial Progenitor Cell Culture Systems: Potential for Stroke Therapy

    PubMed Central

    TAKIZAWA, Shunya; NAGATA, Eiichiro; NAKAYAMA, Taira; MASUDA, Haruchika; ASAHARA, Takayuki

    2016-01-01

    Endothelial progenitor cells (EPCs) participate in endothelial repair and angiogenesis due to their abilities to differentiate into endothelial cells and to secrete protective cytokines and growth factors. Consequently, there is considerable interest in cell therapy with EPCs isolated from peripheral blood to treat various ischemic injuries. Quality and quantity-controlled culture systems to obtain mononuclear cells enriched in EPCs with well-defined angiogenic and anti-inflammatory phenotypes have recently been developed, and increasing evidence from animal models and clinical trials supports the idea that transplantation of EPCs contributes to the regenerative process in ischemic organs and is effective for the therapy of ischemic cerebral injury. Here, we briefly describe the general characteristics of EPCs, and we review recent developments in culture systems and applications of EPCs and EPC-enriched cell populations to treat ischemic stroke. PMID:27041632

  4. Mesenchymal Stem Cells engineered for Cancer