Establishment of Donor Chimerism Using Allogeneic Bone Marrow with AMP Cell Co-infusion

DTIC Science & Technology

2016-09-01

specific immunosuppression. Induction of tolerance to the CTA is the ideal solution. Combined mixed allogeneic chimerism induction and kidney ...transplantation has been shown to induce robust tolerance to the kidney allograft despite transient mixed chimerism in non-human primates and humans...solution. Mixed chimerism induction via hematopoietic cell transplantation (HCT) has been shown to facilitate tolerance induction to kidney allografts

Premise and promise of mesenchymal stem cell-based therapies in clinical vascularized composite allotransplantation.

PubMed

Schweizer, Riccardo; Gorantla, Vijay S; Plock, Jan A

2015-12-01

Over the past decade, clinical vascularized composite allotransplantation (VCA) has enabled functional and quality of life restoration in a wide range of indications secondary to devastating tissue loss. However, the spectre of toxicity and long-term complications of chronic immunosuppression has curtailed the momentum of VCA. This study summarizes the literature evidence behind successful mesenchymal stem cell (MSC)-based cell therapies highlighting their multipronged immunomodulatory, restorative and regenerative characteristics with special emphasis towards VCA applications. Experimental and clinical studies in solid organs and VCA have confirmed that MSCs facilitate immunosuppression-free allograft survival or tolerance, stimulate peripheral nerve regeneration, attenuate ischaemia-reperfusion injury, and improve tissue healing after surgery. It has been hypothesized that MSC-induced long-term operational tolerance in experimental VCA is mediated by induction of mixed donor-specific chimerism and regulatory T-cell mechanisms. All these characteristics of MSCs could thus help expand the scope and clinical feasibility of VCA. Cellular therapies, especially those focusing on MSCs, are emerging in solid organ transplantation including VCA. Although some clinical trials have begun to assess the effects of MSCs in solid organ transplantation, much scientific domain remains uncharted, especially for VCA.

Heart transplantation: challenges facing the field.

PubMed

Tonsho, Makoto; Michel, Sebastian; Ahmed, Zain; Alessandrini, Alessandro; Madsen, Joren C

2014-05-01

There has been significant progress in the field of heart transplantation over the last 45 years. The 1-yr survival rates following heart transplantation have improved from 30% in the 1970s to almost 90% in the 2000s. However, there has been little change in long-term outcomes. This is mainly due to chronic rejection, malignancy, and the detrimental side effects of chronic immunosuppression. In addition, over the last decade, new challenges have arisen such as increasingly complicated recipients and antibody-mediated rejection. Most, if not all, of these obstacles to long-term survival could be prevented or ameliorated by the induction of transplant tolerance wherein the recipient's immune system is persuaded not to mount a damaging immune response against donor antigens, thus eliminating the need for chronic immunosuppression. However, the heart, as opposed to other allografts like kidneys, appears to be a tolerance-resistant organ. Understanding why organs like kidneys and livers are prone to tolerance induction, whereas others like hearts and lungs are tolerance-resistant, could aid in our attempts to achieve long-term, immunosuppression-free survival in human heart transplant recipients. It could also advance the field of pig-to-human xenotransplantation, which, if successful, would eliminate the organ shortage problem. Of course, there are alternative futures to the field of heart transplantation that may include the application of total mechanical support, stem cells, or bioengineered whole organs. Which modality will be the first to reach the ultimate goal of achieving unlimited, long-term, circulatory support with minimal risk to longevity or lifestyle is unknown, but significant progress in being made in each of these areas.

Heart Transplantation: Challenges Facing the Field

PubMed Central

Tonsho, Makoto; Michel, Sebastian; Ahmed, Zain; Alessandrini, Alessandro; Madsen, Joren C.

2014-01-01

There has been significant progress in the field of heart transplantation over the last 45 years. The 1-yr survival rates following heart transplantation have improved from 30% in the 1970s to almost 90% in the 2000s. However, there has been little change in long-term outcomes. This is mainly due to chronic rejection, malignancy, and the detrimental side effects of chronic immunosuppression. In addition, over the last decade, new challenges have arisen such as increasingly complicated recipients and antibody-mediated rejection. Most, if not all, of these obstacles to long-term survival could be prevented or ameliorated by the induction of transplant tolerance wherein the recipient’s immune system is persuaded not to mount a damaging immune response against donor antigens, thus eliminating the need for chronic immunosuppression. However, the heart, as opposed to other allografts like kidneys, appears to be a tolerance-resistant organ. Understanding why organs like kidneys and livers are prone to tolerance induction, whereas others like hearts and lungs are tolerance-resistant, could aid in our attempts to achieve long-term, immunosuppression-free survival in human heart transplant recipients. It could also advance the field of pig-to-human xenotransplantation, which, if successful, would eliminate the organ shortage problem. Of course, there are alternative futures to the field of heart transplantation that may include the application of total mechanical support, stem cells, or bioengineered whole organs. Which modality will be the first to reach the ultimate goal of achieving unlimited, long-term, circulatory support with minimal risk to longevity or lifestyle is unknown, but significant progress in being made in each of these areas. PMID:24789875

Oral tolerance induction for human food allergy.

PubMed

Noh, Geunwoong; Lee, Jae Ho

2012-04-01

Food allergies are classified as IgE-mediated and non-IgE mediated type. The number of successful reports of immunotherapy, namely tolerance induction for food allergy (TIFA) are increasing, bringing hope for meaningful positive and radical treatment of food allergy. Therapeutic characteristics of the clinical course in TIFA for NFA are different from TIFA for IFA. Cytokines including IL-10, TGF-β and IFN-γ and regulatory cells such as Treg and Breg, are involved in immune tolerance. IFN-γ has been used for tolerance induction of food allergy as an immunomodulatory biologics. A definitive distinction between IgE-mediated and non-IgE-mediated food allergies is absolutely essential for diagnostic and therapeutic purposes. Original SOTI using IFN-γ is more effective then conventional SOTI without IFN-γ. Especially, IFN-γ is absolutely necessary for the tolerance induction of NFA. This review highlights and updates the advances in the conceptual immunological background and the clinical characteristics of oral tolerance induction for food allergy.

Regulatory dendritic cells: there is more than just immune activation.

PubMed

Schmidt, Susanne V; Nino-Castro, Andrea C; Schultze, Joachim L

2012-01-01

The immune system exists in a delicate equilibrium between inflammatory responses and tolerance. This unique feature allows the immune system to recognize and respond to potential threats in a controlled but normally limited fashion thereby preventing a destructive overreaction against healthy tissues. While the adaptive immune system was the major research focus concerning activation vs. tolerance in the immune system more recent findings suggest that cells of the innate immune system are important players in the decision between effective immunity and induction of tolerance or immune inhibition. Among immune cells of the innate immune system dendritic cells (DCs) have a special function linking innate immune functions with the induction of adaptive immunity. DCs are the primary professional antigen presenting cells (APCs) initiating adaptive immune responses. They belong to the hematopoietic system and arise from CD34(+) stem cells in the bone marrow. Particularly in the murine system two major subgroups of DCs, namely myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) can be distinguished. DCs are important mediators of innate and adaptive immunity mostly due to their remarkable capacity to present processed antigens via major histocompatibility complexes (MHC) to T cells and B cells in secondary lymphoid organs. A large body of literature has been accumulated during the last two decades describing which role DCs play during activation of T cell responses but also during the establishment and maintenance of central tolerance (Steinman et al., 2003). While the concept of peripheral tolerance has been clearly established during the last years, the role of different sets of DCs and their particular molecular mechanisms of immune deviation has not yet fully been appreciated. In this review we summarize accumulating evidence about the role of regulatory DCs in situations where the balance between tolerance and immunogenicity has been altered leading to pathologic conditions such as chronic inflammation or malignancies.

Regulatory dendritic cells: there is more than just immune activation

PubMed Central

Schmidt, Susanne V.; Nino-Castro, Andrea C.; Schultze, Joachim L.

2012-01-01

The immune system exists in a delicate equilibrium between inflammatory responses and tolerance. This unique feature allows the immune system to recognize and respond to potential threats in a controlled but normally limited fashion thereby preventing a destructive overreaction against healthy tissues. While the adaptive immune system was the major research focus concerning activation vs. tolerance in the immune system more recent findings suggest that cells of the innate immune system are important players in the decision between effective immunity and induction of tolerance or immune inhibition. Among immune cells of the innate immune system dendritic cells (DCs) have a special function linking innate immune functions with the induction of adaptive immunity. DCs are the primary professional antigen presenting cells (APCs) initiating adaptive immune responses. They belong to the hematopoietic system and arise from CD34+ stem cells in the bone marrow. Particularly in the murine system two major subgroups of DCs, namely myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) can be distinguished. DCs are important mediators of innate and adaptive immunity mostly due to their remarkable capacity to present processed antigens via major histocompatibility complexes (MHC) to T cells and B cells in secondary lymphoid organs. A large body of literature has been accumulated during the last two decades describing which role DCs play during activation of T cell responses but also during the establishment and maintenance of central tolerance (Steinman et al., 2003). While the concept of peripheral tolerance has been clearly established during the last years, the role of different sets of DCs and their particular molecular mechanisms of immune deviation has not yet fully been appreciated. In this review we summarize accumulating evidence about the role of regulatory DCs in situations where the balance between tolerance and immunogenicity has been altered leading to pathologic conditions such as chronic inflammation or malignancies. PMID:22969767

Safety and tolerability of allogeneic dendritic cell vaccination with induction of Wilms tumor 1-specific T cells in a pediatric donor and pediatric patient with relapsed leukemia: a case report and review of the literature.

PubMed

Saito, Shoji; Yanagisawa, Ryu; Yoshikawa, Kentaro; Higuchi, Yumiko; Koya, Terutsugu; Yoshizawa, Kiyoshi; Tanaka, Miyuki; Sakashita, Kazuo; Kobayashi, Takashi; Kurata, Takashi; Hirabayashi, Koichi; Nakazawa, Yozo; Shiohara, Masaaki; Yonemitsu, Yoshikazu; Okamoto, Masato; Sugiyama, Haruo; Koike, Kenichi; Shimodaira, Shigetaka

2015-03-01

A 15-year-old girl with acute lymphoblastic leukemia received allogeneic dendritic cell vaccination, pulsed with Wilms tumor 1 (WT1) peptide, after her third hematopoietic stem cell transplantation (HSCT). The vaccines were generated from the third HSCT donor, who was her younger sister, age 12 years. The patient received 14 vaccines and had no graft-versus-host disease or systemic adverse effect, aside from grade 2 skin reaction at the injection site. WT1-specific immune responses were detected after vaccination by both WT1-tetramer analysis and enzyme-linked immunosorbent spot assay. This strategy may be safe, tolerable and even feasible for patients with a relapse after HSCT. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Plasmacytoid dendritic cells: no longer an enigma and now key to transplant tolerance?

PubMed Central

Rogers, NM; Isenberg, JS; Thomson, AW

2014-01-01

Plasmacytoid (p) dendritic cells (DC) are a specialized subset of DC whose primary role was initially defined by the production of type I interferons in response to viral infection. They are now known to also possess a repertoire of functions capable of determining T cell fate and activation. Under homeostatic conditions, non-lymphoid tissue-resident pDC play a critical role in the regulation of mucosal immunity, as well as the development of central and peripheral tolerance. Although these cells display a number of characteristics that differ from conventional DC, particularly altered costimulatory molecule expression and poor allostimulatory capacity when interacting with T cells, this phenotype favors the generation of alloantigen-specific regulatory CD4+ or CD8+ T cells critical to the development of graft tolerance. In this minireview we discuss pDC ontogeny, functional biology and the emerging data that demonstrate the importance of pDC in the induction of tolerance, as well as recent studies that define mechanisms underlying pDC-mediated tolerance to both solid organ and hematopoietic stem cell transplantats. We also highlight their use in clinical settings and the potential of pDC both as targets and cellular therapeutic agents to improve the outcome of organ transplantation. PMID:23617754

Recent Progress in Cell Therapy in Solid Organ Transplantation

PubMed Central

Garakani, R.; Saidi, R. F.

2017-01-01

There has been ample of preclinical and animal studies showing efficacy and safety of using various cells, such as stem cells or T regulatory cells, after transplantation for tissue repair, immunosuppression or tolerance induction. However, there has been a significant progress recently using cell therapy in solid organ transplantation in small clinical trials. Recent results have been promising and using cell therapy in solid organ transplantation seems feasible and safe. However, there are more hurdles to overcome such as dose and timing of the infusions. Current studies mainly focused on live donor kidney transplantation. Expansion of current regimes to other organs and deceased donor transplantation would be crucial. PMID:28924460

Transplantation of Reprogrammed Autologous Stem Cells for Chronic Pain and Drug Abuse

DTIC Science & Technology

2016-07-01

from mesenchymal stem cells (MSCs) and to investigate the analgesic and anti- tolerance effects and the safety of CLCs in animal models. We have...had significant analgesic and robust anti-tolerance effects in both cellular and animal models. Our research has led to 5 poster presentations at...reprogramming, Pain management, Tolerance, Drug abuse, Cell cultures, Spinal transplantation of autologous stem cells, Animal behavioral tests 16. SECURITY

Induction of transplantation tolerance to fully mismatched cardiac allografts by T cell mediated delivery of alloantigen

PubMed Central

Tian, Chaorui; Yuan, Xueli; Jindra, Peter T.; Bagley, Jessamyn; Sayegh, Mohamed H.; Iacomini, John

2010-01-01

Induction of transplantation tolerance has the potential to allow for allograft acceptance without the need for life-long immunosuppression. Here we describe a novel approach that uses delivery of alloantigen by mature T cells to induce tolerance to fully allogeneic cardiac grafts. Adoptive transfer of mature alloantigen-expressing T cells into myeloablatively conditioned mice results in long-term acceptance of fully allogeneic heart transplants without evidence of chronic rejection. Since myeloablative conditioning is clinically undesirable we further demonstrated that adoptive transfer of mature alloantigen-expressing T cells alone into mice receiving non-myeloablative conditioning resulted in long-term acceptance of fully allogeneic heart allografts with minimal evidence of chronic rejection. Mechanistically, tolerance induction involved both deletion of donor-reactive host T cells and the development of regulatory T cells. Thus, delivery of alloantigen by mature T cells induces tolerance to fully allogeneic organ allografts in non-myeloablatively conditioned recipients, representing a novel approach for tolerance induction in transplantation. PMID:20452826

Stem hydraulic traits and leaf water-stress tolerance are co-ordinated with the leaf phenology of angiosperm trees in an Asian tropical dry karst forest

PubMed Central

Fu, Pei-Li; Jiang, Yan-Juan; Wang, Ai-Ying; Brodribb, Tim J.; Zhang, Jiao-Lin; Zhu, Shi-Dan; Cao, Kun-Fang

2012-01-01

Background and Aims The co-occurring of evergreen and deciduous angiosperm trees in Asian tropical dry forests on karst substrates suggests the existence of different water-use strategies among species. In this study it is hypothesized that the co-occurring evergreen and deciduous trees differ in stem hydraulic traits and leaf water relationships, and there will be correlated evolution in drought tolerance between leaves and stems. Methods A comparison was made of stem hydraulic conductivity, vulnerability curves, wood anatomy, leaf life span, leaf pressure–volume characteristics and photosynthetic capacity of six evergreen and six deciduous tree species co-occurring in a tropical dry karst forest in south-west China. The correlated evolution of leaf and stem traits was examined using both traditional and phylogenetic independent contrasts correlations. Key Results It was found that the deciduous trees had higher stem hydraulic efficiency, greater hydraulically weighted vessel diameter (Dh) and higher mass-based photosynthetic rate (Am); while the evergreen species had greater xylem-cavitation resistance, lower leaf turgor-loss point water potential (π0) and higher bulk modulus of elasticity. There were evolutionary correlations between leaf life span and stem hydraulic efficiency, Am, and dry season π0. Xylem-cavitation resistance was evolutionarily correlated with stem hydraulic efficiency, Dh, as well as dry season π0. Both wood density and leaf density were closely correlated with leaf water-stress tolerance and Am. Conclusions The results reveal the clear distinctions in stem hydraulic traits and leaf water-stress tolerance between the co-occurring evergreen and deciduous angiosperm trees in an Asian dry karst forest. A novel pattern was demonstrated linking leaf longevity with stem hydraulic efficiency and leaf water-stress tolerance. The results show the correlated evolution in drought tolerance between stems and leaves. PMID:22585930

Interspecific Potato Breeding Lines Display Differential Colonization Patterns and Induced Defense Responses after Ralstonia solanacearum Infection

PubMed Central

Ferreira, Virginia; Pianzzola, María J.; Vilaró, Francisco L.; Galván, Guillermo A.; Tondo, María L.; Rodriguez, María V.; Orellano, Elena G.; Valls, Marc; Siri, María I.

2017-01-01

Potato (Solanum tuberosum L.) is one of the main hosts of Ralstonia solanacearum, the causative agent of bacterial wilt. This plant pathogen bacteria produce asymptomatic latent infections that promote its global spread, hindering disease control. A potato breeding program is conducted in Uruguay based on the introgression of resistance from the wild native species S. commersonii Dun. Currently, several backcrosses were generated exploiting the high genetic variability of this wild species resulting in advanced interspecific breeding lines with different levels of bacterial wilt resistance. The overall aim of this work was to characterize the interaction of the improved potato germplasm with R. solanacearum. Potato clones with different responses to R. solanacearum were selected, and colonization, dissemination and multiplication patterns after infection were evaluated. A R. solanacearum strain belonging to the phylotype IIB-sequevar 1, with high aggressiveness on potato was genetically modified to constitutively generate fluorescence and luminescence from either the green fluorescence protein gene or lux operon. These reporter strains were used to allow a direct and precise visualization of fluorescent and luminescent cells in plant tissues by confocal microscopy and luminometry. Based on wilting scoring and detection of latent infections, the selected clones were classified as susceptible or tolerant, while no immune-like resistance response was identified. Typical wilting symptoms in susceptible plants were correlated with high concentrations of bacteria in roots and along the stems. Tolerant clones showed a colonization pattern restricted to roots and a limited number of xylem vessels only in the stem base. Results indicate that resistance in potato is achieved through restriction of bacterial invasion and multiplication inside plant tissues, particularly in stems. Tolerant plants were also characterized by induction of anatomical and biochemical changes after R. solanacearum infection, including hyperplasic activity of conductor tissue, tylose production, callose and lignin deposition, and accumulation of reactive oxygen species. This study highlights the potential of the identified tolerant interspecific potato clones as valuable genetic resources for potato-breeding programs and leads to a better understanding of resistance against R. solanacearum in potato. PMID:28894453

Oral tolerance in neonates: from basics to potential prevention of allergic disease.

PubMed

Verhasselt, V

2010-07-01

Oral tolerance refers to the observation that prior feeding of an antigen induces local and systemic immune tolerance to that antigen. Physiologically, this process is probably of central importance for preventing inflammatory responses to the numerous dietary and microbial antigens present in the gut. Defective oral tolerance can lead to gut inflammatory disease, food allergies, and celiac disease. In the last two cases, the diseases develop early in life, stressing the necessity of understanding how oral tolerance is set up in neonates. This article reviews the parameters that have been outlined in adult animal models as necessary for tolerance induction and assesses whether these factors operate in neonates. In addition, we highlight the factors that are specific for this period of life and discuss how they could have an impact on oral tolerance. We pay particular attention to maternal influence on early oral tolerance induction through breast-feeding and outline the major parameters that could be modified to optimize tolerance induction in early life and possibly prevent allergic diseases.

Breast milk immune complexes are potent inducers of oral tolerance in neonates and prevent asthma development.

PubMed

Mosconi, E; Rekima, A; Seitz-Polski, B; Kanda, A; Fleury, S; Tissandie, E; Monteiro, R; Dombrowicz, D D; Julia, V; Glaichenhaus, N; Verhasselt, V

2010-09-01

Allergic asthma is a chronic lung disease resulting from an inappropriate T helper (Th)-2 response to environmental antigens. Early tolerance induction is an attractive approach for primary prevention of asthma. Here, we found that breastfeeding by antigen-sensitized mothers exposed to antigen aerosols during lactation induced a robust and long-lasting antigen-specific protection from asthma. Protection was more profound and persistent than the one induced by antigen-exposed non-sensitized mothers. Milk from antigen-exposed sensitized mothers contained antigen-immunoglobulin (Ig) G immune complexes that were transferred to the newborn through the neonatal Fc receptor resulting in the induction of antigen-specific FoxP3(+) CD25(+) regulatory T cells. The induction of oral tolerance by milk immune complexes did not require the presence of transforming growth factor-beta in milk in contrast to tolerance induced by milk-borne free antigen. Furthermore, neither the presence of IgA in milk nor the expression of the inhibitory FcgammaRIIb in the newborn was required for tolerance induction. This study provides new insights on the mechanisms of tolerance induction in neonates and highlights that IgG immune complexes found in breast milk are potent inducers of oral tolerance. These observations may pave the way for the identification of key factors for primary prevention of immune-mediated diseases such as asthma.

Timing and Frequency of Sublethal Exposure Modifies the Induction and Retention of Increased Insecticide Tolerance in Wood Frogs (Lithobates sylvaticus).

PubMed

Jones, Devin K; Yates, Erika K; Mattes, Brian M; Hintz, William D; Schuler, Matthew S; Relyea, Rick A

2018-05-22

While the paradigm for increased tolerance to pesticides has been by selection on constitutive (naïve) traits, recent research has shown it can also occur through phenotypic plasticity. However, the time period in which induction can occur, the duration of induced tolerance, and the influence of multiple induction events remain unknown. We hypothesized that the induction of increased pesticide tolerance is limited to early sensitive periods, the magnitude of induced tolerance depends on the number of exposures, and the retention of induced tolerance depends on the time elapsed after an exposure and the number of exposures. To test these hypotheses, we exposed wood frog tadpoles to either a no-carbaryl control (water) or 0.5 mg/L carbaryl at four time periods, and later tested their tolerance to carbaryl using time-to-death assays. We discovered that tadpoles induced increased tolerance early and midway, but not late, in our experiment and their constitutive tolerance increased with age. We found no difference in the magnitude of induced tolerance following one or two exposures. Lastly, induced pesticide tolerance was reversed within 6 d, but was retained only when tadpoles experienced all four consecutive exposures. Phenotypic plasticity provides an immediate response for sensitive amphibian larvae to early pesticide exposures and reduces phenotypic mismatches in aquatic environments contaminated by agrochemicals. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

In situ induction of dendritic cell–based T cell tolerance in humanized mice and nonhuman primates

PubMed Central

Jung, Kyeong Cheon; Jeon, Yoon Kyung; Ban, Young Larn; Min, Hye Sook; Kim, Eun Ji; Kim, Ju Hyun; Kang, Byung Hyun; Bae, Youngmee; Yoon, Il-Hee; Kim, Yong-Hee; Lee, Jae-Il; Kim, Jung-Sik; Shin, Jun-Seop; Yang, Jaeseok; Kim, Sung Joo; Rostlund, Emily; Muller, William A.

2011-01-01

Induction of antigen-specific T cell tolerance would aid treatment of diverse immunological disorders and help prevent allograft rejection and graft versus host disease. In this study, we establish a method of inducing antigen-specific T cell tolerance in situ in diabetic humanized mice and Rhesus monkeys receiving porcine islet xenografts. Antigen-specific T cell tolerance is induced by administration of an antibody ligating a particular epitope on ICAM-1 (intercellular adhesion molecule 1). Antibody-mediated ligation of ICAM-1 on dendritic cells (DCs) led to the arrest of DCs in a semimature stage in vitro and in vivo. Ablation of DCs from mice completely abrogated anti–ICAM-1–induced antigen-specific T cell tolerance. T cell responses to unrelated antigens remained unaffected. In situ induction of DC-mediated T cell tolerance using this method may represent a potent therapeutic tool for preventing graft rejection. PMID:22025302

Enhancement of Oral Tolerance Induction in DO11.10 Mice by Lactobacillus gasseri OLL2809 via Increase of Effector Regulatory T Cells.

PubMed

Aoki-Yoshida, Ayako; Yamada, Kiyoshi; Hachimura, Satoshi; Sashihara, Toshihiro; Ikegami, Shuji; Shimizu, Makoto; Totsuka, Mamoru

2016-01-01

Food allergy is a serious problem for infants and young children. Induction of antigen-specific oral tolerance is one therapeutic strategy. Enhancement of oral tolerance induction by diet is a promising strategy to prevent food allergy in infants. Thus, in this study, we evaluate the effect of probiotic Lactobacillus gasseri OLL2809 (LG2809) on oral tolerance induction in a mouse model. The degree of oral tolerance induction was evaluated by measuring the proliferation and level of IL-2 production of splenic CD4+ T cells from DO11.10 mice fed ovalbumin (OVA) alone or OVA with LG2809. Oral administration of LG2809 significantly decreased the rate of proliferation and IL-2 production by CD4+ T cells from OVA-fed mice. LG2809 increased a ratio of CD4+ T-cell population, producing high levels of IL-10 and having strong suppressive activity. Moreover, LG2809 increased a ratio of plasmacytoid dendritic cells (pDCs) among the lamina propria (LP) in small intestine. When used as antigen presenting cells to naïve CD4+ T cells from DO11.10 mice, LP cells from BALB/c mice fed LG2809 induced higher IL-10 production and stronger suppressive activity than those from non-treated mice. These results suggest that oral administration of LG2809 increases the population of pDCs in the LP, resulting in the enhancement of oral tolerance induction by increasing the ratio of effector regulatory T cells. LG2809 could, therefore, act as a potent immunomodulator to prevent food allergies by promoting oral tolerance.

Tolerance to MHC class II disparate allografts through genetic modification of bone marrow

PubMed Central

Jindra, Peter T.; Tripathi, Sudipta; Tian, Chaorui; Iacomini, John; Bagley, Jessamyn

2012-01-01

Induction of molecular chimerism through genetic modification of bone marrow is a powerful tool for the induction of tolerance. Here we demonstrate for the first time that expression of an allogeneic MHC class II gene in autologous bone marrow cells, resulting in a state of molecular chimerism, induces tolerance to MHC class II mismatched skin grafts, a stringent test of transplant tolerance. Reconstitution of recipients with syngeneic bone marrow transduced with retrovirus encoding H-2I-Ab (I-Ab) resulted the long-term expression of the retroviral gene product on the surface of MHC class II-expressing bone marrow derived cell types. Mechanistically, tolerance was maintained by the presence of regulatory T cells, which prevented proliferation and cytokine production by alloreactive host T cells. Thus, the introduction of MHC class II genes into bone marrow derived cells through genetic engineering results in tolerance. These results have the potential to extend the clinical applicability of molecular chimerism for tolerance induction. PMID:22833118

Specialist Insect Herbivore and Light Availability Do Not Interact in the Evolution of an Invasive Plant

PubMed Central

Zhang, Ziyan; He, Kate S.; Li, Bo

2015-01-01

Release from specialist insect herbivores may allow invasive plants to evolve traits associated with decreased resistance and increased competitive ability. Given that there may be genetic trade-off between resistance and tolerance, invasive plants could also become more tolerant to herbivores. Although it is widely acknowledged that light availability affects tolerance to herbivores, little information is available for whether the effect of light availability on tolerance differ between the introduced and native populations. We conducted a common garden experiment in the introduced range of Alternanthera philoxeroides using ten invasive US and ten native Argentinean populations at two levels of light availability and in the presence or absence of a specialist stem-boring insect Agasicles hygrophila. Plant biomass (total and storage root biomass), two allocation traits (root/shoot ratio and branch intensity, branches biomass/main stem biomass) and two functional traits (specific stem length and specific leaf area), which are potentially associated with herbivore resistance and light capture, were measured. Overall, we found that A. philoxeroides from introduced ranges had comparable biomass and tolerance to specialist herbivores, lower branch intensity, lower specific stem length and specific leaf area. Moreover, introduced populations displayed higher shade tolerance of storage root biomass and lower plastic response to shading in specific stem length. Finally, light availability had no significant effect on evolution of tolerance to specialist herbivores of A. philoxeroides. Our results suggest that post-introduction evolution might have occurred in A. philoxeroides. While light availability did not influence the evolution of tolerance to specialist herbivores, increased shade tolerance and release from specialist insects might have contributed to the successful invasion of A. philoxeroides. PMID:26407176

Long-Term Tolerance Towards Haploidentical Vascularized Composite Allograft Transplantation in a Canine Model Using Bone Marrow or Mobilized Stem Cells

PubMed Central

Chang, Jeff; Graves, Scott S.; Butts-Miwongtum, Tiffany; Sale, George E.; Storb, Rainer; Mathes, David W.

2017-01-01

Background The development of safe and reliable protocols for the transplantation of the face and hands may be accomplished with animal modeling of transplantation of vascularized composite allografts (VCA). Previously, we demonstrated that tolerance to a VCA could be achieved after canine recipients were simultaneously given marrow from a dog leukocyte antigen (DLA) identical donor. In the present study, we extend those findings across a DLA mismatched barrier. Methods Eight Recipient dogs received total body irradiation (4.5 cGy), hematopoietic cell transplantation (HCT), either marrow (n=4) or granulocyte-colony stimulating factor (G-CSF) mobilized peripheral blood stem cells (n=4), and a VCA transplant from the HCT donor. Post grafting immunosuppression consisted of mycophenolate mofetil (28 days) and cyclosporine (35 days). Results In 4 dogs receiving bone marrow, 1 accepted both its marrow transplant and demonstrated long-term tolerance to the donor VCA (>52 weeks). Three dogs rejected both their marrow transplants and VCA at 5–7 weeks posttransplant. Dogs receiving mobilized stem cells all accepted their stem cell transplant and became tolerant to the VCA. However, 3 dogs developed graft-versus-host disease (GVHD) while 1 dog rejected its stem cell graft by week 15 but exhibited long-term tolerance towards its VCA (>90 weeks). Conclusion The data suggest that simultaneous transplantation of mobilized stem cells and a VCA is feasible and leads to tolerance towards the VCA in a haploidentical setting. However, there is a higher rate of donor stem cell engraftment compared to marrow HCT and an increase in the incidence of GVHD. PMID:27861292

Feasibility, toxicity and response of upfront metaiodobenzylguanidine therapy therapy followed by German Pediatric Oncology Group Neuroblastoma 2004 protocol in newly diagnosed stage 4 neuroblastoma patients.

PubMed

Kraal, K C J M; Bleeker, G M; van Eck-Smit, B L F; van Eijkelenburg, N K A; Berthold, F; van Noesel, M M; Caron, H N; Tytgat, G A M

2017-05-01

Radiolabelled meta-iodobenzylguanidine (MIBG) is an effective option in treatment of neuroblastoma (NBL) tumours. We studied feasibility, toxicity and efficacy of upfront 131 I-MIBG and induction treatment in stage 4 NBL patients. Retrospective, multi-centre (AMC and EMC) pilot regimen (1/1/2005-2011). Newly diagnosed stage 4 NBL patients, were treated with 2 courses of 131 I-MIBG, GPOH 2004 NBL protocol, myeloablative therapy (MAT) and autologous stem cell rescue (ASCT). 131 I-MIBG was administered in a fixed dose. Response rate (RR) was defined as complete remission, very good partial response and partial response. Thirty-two patients, (median age [range] 2.9 [0-11.4] years), 21 received 131 I-MIBG therapy, 11 did not because of: MIBG non-avid (N = 5) and poor clinical condition (N = 6). In 95% of eligible patients 131 I-MIBG treatment was feasible within 2 weeks from diagnosis. Interval between chemotherapy courses was 25 days ( 131 I-MIBG group) versus 22 days (chemotherapy group). No stem cell support was needed after 131 I-MIBG therapy. Stem cell harvest in both groups was feasible, neutrophil recovery was comparable, but platelet recovery post MAT, ASCT was slower for 131 I-MIBG-treated patients. RR post 131 I-MIBG was 38%, post MAT + ASCT was 71% ( 131 I-MIBG group), 36% (chemotherapy group) and overall 59%. Induction therapy with 131 I-MIBG before the HR GPOH NB 2004 protocol is feasible, tolerable and effective in newly diagnosed stage 4 NBL patients. 131 I-MIBG upfront therapy induces early responses. Copyright © 2017 Elsevier Ltd. All rights reserved.

Wnt and Notch Pathways Have Interrelated Opposing Roles on Prostate Progenitor Cell Proliferation and Differentiation

PubMed Central

Shahi, Payam; Seethammagari, Mamatha R.; Valdez, Joseph M.; Xin, Li; Spencer, David M.

2011-01-01

Tissue stem cells are capable of both self-renewal and differentiation to maintain a constant stem cell population and give rise to the plurality of cells within a tissue. Wnt signaling has been previously identified as a key mediator for the maintenance of tissue stem cells; however, possible cross-regulation with other developmentally critical signaling pathways involved in adult tissue homeostasis, such as Notch, is not well understood. By using an in vitro prostate stem cell colony (“prostasphere”) formation assay and in vivo prostate reconstitution experiments, we demonstrate that Wnt pathway induction on Sca-1+ CD49f+ basal/stem cells (B/SCs) promotes expansion of the basal epithelial compartment with noticeable increases in “triple positive” (cytokeratin [CK] 5+, CK8+, p63+) prostate progenitor cells, concomitant with upregulation of known Wnt target genes involved in cell-cycle induction. Moreover, Wnt induction affects expression of epithelial-to-mesenchymal transition signature genes, suggesting a possible mechanism for priming B/SC to act as potential tumor-initiating cells. Interestingly, induction of Wnt signaling in B/SCs results in downregulation of Notch1 transcripts, consistent with its postulated antiproliferative role in prostate cells. In contrast, induction of Notch signaling in prostate progenitors inhibits their proliferation and disrupts prostasphere formation. In vivo prostate reconstitution assays further demonstrate that induction of Notch in B/SCs disrupts proper acini formation in cells expressing the activated Notch1 allele, Notch-1 intracellular domain. These data emphasize the importance of Wnt/Notch cross-regulation in adult stem cell biology and suggest that Wnt signaling controls the proliferation and/or maintenance of epithelial progenitors via modulation of Notch signaling. PMID:21308863

Interleukin-10 Gene-Modified Dendritic Cell-Induced Type 1 Regulatory T Cells Induce Transplant-Tolerance and Impede Graft Versus Host Disease After Allogeneic Stem Cell Transplantation.

PubMed

Wan, Jiangbo; Huang, Fang; Hao, Siguo; Hu, Weiwei; Liu, Chuanxu; Zhang, Wenhao; Deng, Xiaohui; Chen, Linjun; Ma, Liyuan; Tao, Rong

2017-01-01

Tr1 cells can induce peripheral tolerance to self- and foreign antigens, and have been developed as a therapeutic tool for the induction of tolerance to transplanted tissue. We explored the feasibility of generating Tr1 cells by using IL-10 gene-modified recipient DCs (DCLV-IL-10) to stimulate donor naive CD4+ T cells. We also investigated some biological properties of Tr1 cells. DCLV-IL-10 were generated through DCs transduced with a lentivirus vector carrying the IL-10 gene, and Tr1 cells were produced by using DCLV-IL-10 to stimulate naive CD4+ T cells. The effects of Tr1 cells on T-cell proliferation and the occurrence of graft versus host disease (GVHD) following allogeneic stem-cell transplantation (allo-HSCT) were investigated. The DCLV-IL-10-induced Tr1 cells co-expressed LAG-3 and CD49b. Moreover, they also expressed CD4, CD25, and IL-10, but not Foxp3, and secreted significantly higher levels of IL-10 (1,729.36 ± 185.79 pg/mL; P < 0.001) and INF-γ (1,524.48 ± 168.65 pg/mL; P < 0.01) than the control T cells upon the stimulation by allogeneic DCs. Tr1 cells markedly suppressed T-lymphocyte proliferation and the mixed lymphocytic response (MLR) in vitro. The mice used in the allo-HSCT model had longer survival times and lower clinical and pathological GVHD scores than the control mice. IL-10 gene-modified DC-induced Tr1 cells may be used as a potent cellular therapy for the prevention of GVHD after allo-HSCT. © 2017 The Author(s). Published by S. Karger AG, Basel.

Comparison of inhibition of N2 fixation and ureide accumulation under water deficit in four common bean genotypes of contrasting drought tolerance

PubMed Central

Coleto, I.; Pineda, M.; Rodiño, A. P.; De Ron, A. M.; Alamillo, J. M.

2014-01-01

Background and Aims Drought is the principal constraint on world production of legume crops. There is considerable variability among genotypes in sensitivity of nitrogen fixation to drought, which has been related to accumulation of ureides in soybean. The aim of this study was to search for genotypic differences in drought sensitivity and ureide accumulation in common bean (Phaseolus vulgaris) germplasm that may be useful in the improvement of tolerance to water deficit in common bean. Methods Changes in response to water deficit of nitrogen fixation rates, ureide content and the expression and activity of key enzymes for ureide metabolism were measured in four P. vulgaris genotypes differing in drought tolerance. Key Results A variable degree of drought-induced nitrogen fixation inhibition was found among the bean genotypes. In addition to inhibition of nitrogen fixation, there was accumulation of ureides in stems and leaves of sensitive and tolerant genotypes, although this was higher in the leaves of the most sensitive ones. In contrast, there was no accumulation of ureides in the nodules or roots of stressed plants. In addition, the level of ureides in the most sensitive genotype increased after inhibition of nitrogen fixation, suggesting that ureides originate in vegetative tissues as a response to water stress, probably mediated by the induction of allantoinase. Conclusions Variability of drought-induced inhibition of nitrogen fixation among the P. vulgaris genotypes was accompanied by subsequent accumulation of ureides in stems and leaves, but not in nodules. The results indicate that shoot ureide accumulation after prolonged exposure to drought could not be the cause of inhibition of nitrogen fixation, as has been suggested in soybean. Instead, ureides seem to be produced as part of a general response to stress, and therefore higher accumulation might correspond to higher sensitivity to the stressful conditions. PMID:24638821

Comparison of inhibition of N2 fixation and ureide accumulation under water deficit in four common bean genotypes of contrasting drought tolerance.

PubMed

Coleto, I; Pineda, M; Rodiño, A P; De Ron, A M; Alamillo, J M

2014-05-01

Drought is the principal constraint on world production of legume crops. There is considerable variability among genotypes in sensitivity of nitrogen fixation to drought, which has been related to accumulation of ureides in soybean. The aim of this study was to search for genotypic differences in drought sensitivity and ureide accumulation in common bean (Phaseolus vulgaris) germplasm that may be useful in the improvement of tolerance to water deficit in common bean. Changes in response to water deficit of nitrogen fixation rates, ureide content and the expression and activity of key enzymes for ureide metabolism were measured in four P. vulgaris genotypes differing in drought tolerance. A variable degree of drought-induced nitrogen fixation inhibition was found among the bean genotypes. In addition to inhibition of nitrogen fixation, there was accumulation of ureides in stems and leaves of sensitive and tolerant genotypes, although this was higher in the leaves of the most sensitive ones. In contrast, there was no accumulation of ureides in the nodules or roots of stressed plants. In addition, the level of ureides in the most sensitive genotype increased after inhibition of nitrogen fixation, suggesting that ureides originate in vegetative tissues as a response to water stress, probably mediated by the induction of allantoinase. Variability of drought-induced inhibition of nitrogen fixation among the P. vulgaris genotypes was accompanied by subsequent accumulation of ureides in stems and leaves, but not in nodules. The results indicate that shoot ureide accumulation after prolonged exposure to drought could not be the cause of inhibition of nitrogen fixation, as has been suggested in soybean. Instead, ureides seem to be produced as part of a general response to stress, and therefore higher accumulation might correspond to higher sensitivity to the stressful conditions.

An improved fault-tolerant control scheme for PWM inverter-fed induction motor-based EVs.

PubMed

Tabbache, Bekheïra; Benbouzid, Mohamed; Kheloui, Abdelaziz; Bourgeot, Jean-Matthieu; Mamoune, Abdeslam

2013-11-01

This paper proposes an improved fault-tolerant control scheme for PWM inverter-fed induction motor-based electric vehicles. The proposed strategy deals with power switch (IGBTs) failures mitigation within a reconfigurable induction motor control. To increase the vehicle powertrain reliability regarding IGBT open-circuit failures, 4-wire and 4-leg PWM inverter topologies are investigated and their performances discussed in a vehicle context. The proposed fault-tolerant topologies require only minimum hardware modifications to the conventional off-the-shelf six-switch three-phase drive, mitigating the IGBTs failures by specific inverter control. Indeed, the two topologies exploit the induction motor neutral accessibility for fault-tolerant purposes. The 4-wire topology uses then classical hysteresis controllers to account for the IGBT failures. The 4-leg topology, meanwhile, uses a specific 3D space vector PWM to handle vehicle requirements in terms of size (DC bus capacitors) and cost (IGBTs number). Experiments on an induction motor drive and simulations on an electric vehicle are carried-out using a European urban driving cycle to show that the proposed fault-tolerant control approach is effective and provides a simple configuration with high performance in terms of speed and torque responses. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Heat Tolerance Induction of the Indian Meal Moth (Lepidoptera: Pyralidae) Is Accompanied by Upregulation of Heat Shock Proteins and Polyols.

PubMed

Kim, Minhyun; Lee, Seunghee; Chun, Yong Shik; Na, Jahyun; Kwon, Hyeok; Kim, Wook; Kim, Yonggyun

2017-08-01

The Indian meal moth, Plodia interpunctella, causes massive damage to stored grains and processed foods. Heat treatment has been widely used to control insect pests infesting stored grains. However, heat treatment may result in unsatisfactory control owing to heat tolerance of target insects. This study quantified the heat tolerance and analyzed its induction in P. interpunctella. Susceptibility of P. interpunctella to different high temperatures was assessed in all developmental stages. Heat treatment at 44 °C for 1 h caused significant mortalities to all developmental stages, with late-instar larvae exhibiting the highest tolerance. However, the survivorship to heat treatment was significantly increased by pre-exposure to 37 °C for 30 min. The induction of heat tolerance was accompanied by upregulation of two heat shock proteins of Hsc70 and Hsp90. Trehalose and glycerol concentrations in the hemolymph also increased after pre-exposure to 37 °C for 30 min. RNA interference (RNAi) by specific double-stranded RNAs effectively suppressed the inducible expressions of both Hsc70 and Hsp90 in response to 37 °C for 30 min. Either RNAi of Hsc70 or Hsp90 significantly impaired the heat tolerance induction of P. interpunctella. These results suggest that the induction of heat tolerance in P. interpunctella involves the upregulation of these heat shock proteins and hemolymph polyol levels. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Prenatal tolerance induction: relationship between cell dose, marrow T-cells, chimerism, and tolerance.

PubMed

Chen, Jeng-Chang; Chang, Ming-Ling; Huang, Shiu-Feng; Chang, Pei-Yeh; Muench, Marcus O; Fu, Ren-Huei; Ou, Liang-Shiou; Kuo, Ming-Ling

2008-01-01

It was reported that the dose of self-antigens can determine the consequence of deletional tolerance and donor T cells are critical for tolerance induction in mixed chimeras. This study aimed at assessing the effect of cell doses and marrow T cells on engraftment and tolerance induction after prenatal bone marrow transplantation. Intraperitoneal cell transplantation was performed in FVB/N (H-2K(q)) mice at gestational day 14 with escalating doses of adult C57BL/6 (H-2K(b)) marrows. Peripheral chimerism was examined postnatally by flow cytometry and tolerance was tested by skin transplantation. Transplantation of light-density marrow cells showed a dose response. High-level chimerism emerged with a threshold dose of 5.0 x 10(6) and host leukocytes could be nearly replaced at a dose of 7.5-10.0 x 10(6). High-dose transplants conferred a steady long-lasting donor-specific tolerance but were accompanied by >50% incidence of graft-versus-host disease. Depletion of marrow T cells lessened graft-versus-host disease to the detriment of engraftment. With low-level chimerism, tolerance was a graded phenomenon dependent upon the level of chimerism. Durable chimerism within 6 months required a threshold of > or = 2% chimerism at 1 month of age and predicted a 50% chance of long-term tolerance, whereas transient chimerism (<2%) only caused hyporesponsiveness to the donor. Tolerance induction did not succeed without peripheral chimerism even if a large amount of injected donor cells persisted in the peritoneum. Neither did an increase in cell doses or donor T-cell contents benefit skin graft survivals unless it had substantially improved peripheral chimerism. Thus, peripheral chimerism level can be a simple and straightforward test to predict the degree of prenatal immune tolerance.

Local Tacrolimus (FK506) Delivery for Prevention of Acute Rejection in the Nonhuman Primate Delayed Mixed Chimerism Vascularized Composite Allograft Tolerance Induction Protocol

DTIC Science & Technology

2016-10-01

Chimerism Vascularized Composite Allograft Tolerance Induction Protocol PRINCIPAL INVESTIGATORS: Dr. Curtis L. Cetrulo CONTRACTING ORGANIZATION...Tacrolimus (FK506) Delivery for Prevention of Acute Rejection in the Nonhuman Primate Delayed Mixed Chimerism Vascularized Composite Allograft Tolerance...tacrolimus, FK506, vascularized composite allografts , immune rejection, preclinical, transplant, nonhuman primate model, degradable polymer, tyrosine

Tolerance of Loblolly Pines to Fusiform Rust

Treesearch

Charles H. Walkinshaw; James P. Barnett

1995-01-01

Loblolly pines (Pinus taeda L.) that were 8 to 17 yr old tolerated one to three fusiform rust (Cronartium quercuum [Berk.] Miyabe ex Shirai f. sp. fusiforme) galls in their stems.Families with four or more galls in their stems lost 2.5% or more of the trees by age 17.In living trees with less than four stem galls, diameter growth was comparable to...

Neurogenic differentiation of dental pulp stem cells to neuron-like cells in dopaminergic and motor neuronal inductive media.

PubMed

Chang, Chia-Chieh; Chang, Kai-Chun; Tsai, Shang-Jye; Chang, Hao-Hueng; Lin, Chun-Pin

2014-12-01

Dental pulp stem cells (DPSCs) have been proposed as a promising source of stem cells in nerve regeneration due to their close embryonic origin and ease of harvest. The aim of this study was to evaluate the efficacy of dopaminergic and motor neuronal inductive media on transdifferentiation of human DPSCs (hDPSCs) into neuron-like cells. Isolation, cultivation, and identification of hDPSCs were performed with morphological analyses and flow cytometry. The proliferation potential of DPSCs was evaluated with an XTT [(2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide)] assay. Media for the induction of dopaminergic and spinal motor neuronal differentiation were prepared. The efficacy of neural induction was evaluated by detecting the expression of neuron cell-specific cell markers in DPSCs by immunocytochemistry and quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). In the XTT assay, there was a 2.6- or 2-fold decrease in DPSCs cultured in dopaminergic or motor neuronal inductive media, respectively. The proportions of βIII-tubulin (βIII-tub), glial fibrillary acidic protein (GFAP), and oligodendrocyte (O1)-positive cells were significantly higher in DPSCs cultured in both neuronal inductive media compared with those cultured in control media. Furthermore, hDPSC-derived dopaminergic and spinal motor neuron cells after induction expressed a higher density of neuron cell markers than those before induction. These findings suggest that in response to the neuronal inductive stimuli, a greater proportion of DPSCs stop proliferation and acquire a phenotype resembling mature neurons. Such neural crest-derived adult DPSCs may provide an alternative stem cell source for therapy-based treatments of neuronal disorders and injury. Copyright © 2014. Published by Elsevier B.V.

Establishment of donor Chimerism Using Allogeneic Bone Marrow with AMP Cell Co-infusion

DTIC Science & Technology

2017-09-01

the ideal solution. Combined mixed allogeneic chimerism induction and kidney transplantation has been shown to induce robust tolerance to the kidney ...induction to kidney allografts in non-human primates and humans despite the transience of donor chimerism. However, evidence indicates that durable mixed...chimerism may be required for tolerance induction to tissues or organs other than kidney . Amnion-derived multipotent progenitor (AMP) cells possess

Heme Oxygenase-1 Induction and Organic Nitrate Therapy: Beneficial Effects on Endothelial Dysfunction, Nitrate Tolerance, and Vascular Oxidative Stress

PubMed Central

Daiber, Andreas; Oelze, Matthias; Wenzel, Philip; Bollmann, Franziska; Pautz, Andrea; Kleinert, Hartmut

2012-01-01

Organic nitrates are a group of very effective anti-ischemic drugs. They are used for the treatment of patients with stable angina, acute myocardial infarction, and chronic congestive heart failure. A major therapeutic limitation inherent to organic nitrates is the development of tolerance, which occurs during chronic treatment with these agents, and this phenomenon is largely based on induction of oxidative stress with subsequent endothelial dysfunction. We therefore speculated that induction of heme oxygenase-1 (HO-1) could be an efficient strategy to overcome nitrate tolerance and the associated side effects. Indeed, we found that hemin cotreatment prevented the development of nitrate tolerance and vascular oxidative stress in response to chronic nitroglycerin therapy. Vice versa, pentaerithrityl tetranitrate (PETN), a nitrate that was previously reported to be devoid of adverse side effects, displayed tolerance and oxidative stress when the HO-1 pathway was blocked pharmacologically or genetically by using HO-1+/– mice. Recently, we identified activation of Nrf2 and HuR as a principle mechanism of HO-1 induction by PETN. With the present paper, we present and discuss our recent and previous findings on the role of HO-1 for the prevention of nitroglycerin-induced nitrate tolerance and for the beneficial effects of PETN therapy. PMID:22506100

Effect of Salt Stress on Growth, Na+ Accumulation and Proline Metabolism in Potato (Solanum tuberosum) Cultivars

PubMed Central

Jaarsma, Rinse; de Vries, Rozemarijn S. M.; de Boer, Albertus H.

2013-01-01

Potato (Solanum tuberosum) is a major crop world-wide and the productivity of currently used cultivars is strongly reduced at high soil salt levels. We compared the response of six potato cultivars to increased root NaCl concentrations. Cuttings were grown hydroponically and treated with 0 mM, 60 mM and 180 mM NaCl for one week. Growth reduction on salt was strongest for the cultivars Mozart and Mona Lisa with a severe senescence response at 180 mM NaCl and Mozart barely survived the treatment. The cultivars Desiree and Russett Burbank were more tolerant showing no senescence after salt treatment. A clear difference in Na+ homeostasis was observed between sensitive and tolerant cultivars. The salt sensitive cultivar Mozart combined low Na+ levels in root and stem with the highest leaf Na+ concentration of all cultivars, resulting in a high Na+ shoot distribution index (SDI) for Mozart as compared to Desiree. Overall, a positive correlation between salt tolerance and stem Na+ accumulation was found and the SDI for Na+ points to a role of stem Na+ accumulation in tolerance. In stem tissue, Mozart accumulated more H2O2 and less proline compared to the tolerant cultivars. Analysis of the expression of proline biosynthesis genes in Mozart and Desiree showed a clear reduction in proline dehydrogenase (PDH) expression in both cultivars and an increase in pyrroline-5-carboxylate synthetase 1 (P5CS1) gene expression in Desiree, but not in Mozart. Taken together, current day commercial cultivars show promising differences in salt tolerance and the results suggest that mechanisms of tolerance reside in the capacity of Na+ accumulation in stem tissue, resulting in reduced Na+ transport to the leaves. PMID:23533673

Successful liver allografts in mice by combination with allogeneic bone marrow transplantation.

PubMed Central

Nakamura, T; Good, R A; Yasumizu, R; Inoue, S; Oo, M M; Hamashima, Y; Ikehara, S

1986-01-01

Successful liver allografts were established by combination with allogeneic bone marrow transplantation. When liver tissue of BALB/c (H-2d) or C57BL/6J (H-2b) mice was minced and grafted under the kidney capsules of C3H/HeN (H-2k) mice, it was rejected. However, when C3H/HeN mice were irradiated and reconstituted with T-cell-depleted BALB/c or BALB/c nu/nu bone marrow cells, or with fetal liver cells of BALB/c mice, they accepted both donor (stem-cell)-type (BALB/c) and host (thymus)-type (C3H/HeN) liver tissue. Assays for both mixed-lymphocyte reaction and induction of cytotoxic T lymphocytes revealed that the newly developed T cells were tolerant of both donor (stem-cell)-type and host (thymus)-type major histocompatibility complex determinants. We propose that liver allografts combined with bone marrow transplantation should be considered as a viable therapy for patients with liver disease such as liver cirrhosis and hepatoma. Images PMID:3520575

Acute tolerance to spinally administered morphine compares mechanistically with chronically induced morphine tolerance.

PubMed

Fairbanks, C A; Wilcox, G L

1997-09-01

The mechanistic similarity between acutely and chronically induced morphine tolerance has been previously proposed but remains largely unexplored. Our experiments examined the modulation of acutely induced tolerance to spinally administered morphine by agonists that affect the N-methyl-D-aspartate receptor and nitric oxide synthase systems. Antinociception was detected via the hot water (52.5 degrees C) tail flick test in mice. Intrathecal pretreatment with morphine (40 nmol) produced a 9.6-fold rightward shift in the morphine dose-response curve. This shift confirmed the induction of acute spinal morphine tolerance. Intrathecal copretreatment with the receptor antagonists (competitive and noncompetitive, respectively) dizolcipine (MK801, 3 nmol) or LY235959 (4 pmol) and morphine [40 nmol, intrathecally (i.t.)] attenuated acute tolerance to morphine measured 8 hr later. A 60-min pretreatment of 7-nitroindazole (6 nmol, i.t.), a selective neuronal NOS inhibitor, followed by administration of morphine (40 nmol, i.t.) blocked the induction of morphine tolerance. Intrathecal copretreatment with morphine (40 nmol, i.t.) and agmatine (4 nmol, i.t.), an imidazoline, receptor agonist and putative nitric oxide synthase inhibitor, almost completely abolished acute spinal morphine tolerance. The results of these experiments agree with previous reports using models of chronically induced morphine tolerance. This evidence supports the proposal that the mechanisms responsible for acute morphine tolerance parallel those underlying chronic morphine tolerance. This study attests to the powerful predictive value of acute induction as a model for morphine tolerance.

Immunochemical, ultrastructural and electrophysiological investigations of bone-derived stem cells in the course of neuronal differentiation.

PubMed

Wenisch, Sabine; Trinkaus, Katja; Hild, Anne; Hose, Dirk; Heiss, Christian; Alt, Volker; Klisch, Christopher; Meissl, Hilmar; Schnettler, Reinhard

2006-06-01

Numerous reports have highlighted the use of mesenchymal stem cells (MSC) for tissue engineering because of the capacity of the cells to differentiate along the osteogenic, chondrogenic or adipogenic pathway. As MSC also display neuronal morphologies under appropriate culture conditions, the differentiation capacity of stem cells seems to be more complex than initially thought, but it requires careful characterization of the cells. This is especially the case because recently it has been suggested that neuronal differentiation of stem cells is only an artifact. Here, we investigate the sequence of ultrastructural changes of bone-derived stem cells during neuronal induction and compare these data with immunocytochemical and electrophysiological properties of the cells. For further comparative analyses, stem cells were incubated with non-neurologically inducing stressors. The stem cells were harvested from human osseous debris and were characterized morphologically, immunocytochemically and by using FACS. After 6 h of neuronal induction, the cells had assumed neuronal morphologies and expressed neuron-specific enolase, beta-III-tubulin, neurofilament-H and HNK-1, while only a subpopulation expressed CD15 and synaptophysin. However, electrical signaling could not be detected, neither spontaneously nor after electrical stimulation. Nevertheless, transmission electron microscopy revealed cellular features of neuritogenesis and synaptogenesis in the course of neuronal induction and suggested that the cells have features similar to those observed in immature neurons. Based upon the results, it can be concluded that neuronal induction had initiated the early steps of neuronal differentiation, while exposure of the cells to non-neurological stressors had caused necrotic alterations.

Induction of Oral Tolerance with Transgenic Plants Expressing Antigens for Prevention/Treatment of Autoimmune, Allergic and Inflammatory Diseases.

PubMed

Ma, Shengwu; Liao, Yu-Cai; Jevnikar, Anthony M

2015-01-01

The prevalence and incidence of autoimmune and allergic diseases have increased dramatically over the last several decades, especially in the developed world. The treatment of autoimmune and allergic diseases is typically with the use of non-specific immunosuppressive agents that compromise the integrity of the host immune system and therefore, increase the risk of infections. Antigenspecific immunotherapy by reinstating immunological tolerance towards self antigens without compromising immune functions is a much desired goal for the treatment of autoimmune and allergic diseases. Mucosal administration of antigen is a long-recognized method of inducing antigen-specific immune tolerance known as oral tolerance, which is viewed as having promising potential in the treatment of autoimmune and allergic diseases. Plant-based expression and delivery of recombinant antigens provide a promising new platform to induce oral tolerance, having considerable advantages including reduced cost and increased safety. Indeed, in recent years the use of tolerogenic plants for oral tolerance induction has attracted increasing attention, and considerable progress has been made. This review summarizes recent advances in using plants to deliver tolerogens for induction of oral tolerance in the treatment of autoimmune, allergic and inflammatory diseases.

Efforts to enhance blood stem cell engraftment: Recent insights from zebrafish hematopoiesis

PubMed Central

Perlin, Julie R.; Robertson, Anne L.

2017-01-01

Hematopoietic stem cell transplantation (HSCT) is an important therapy for patients with a variety of hematological malignancies. HSCT would be greatly improved if patient-specific hematopoietic stem cells (HSCs) could be generated from induced pluripotent stem cells in vitro. There is an incomplete understanding of the genes and signals involved in HSC induction, migration, maintenance, and niche engraftment. Recent studies in zebrafish have revealed novel genes that are required for HSC induction and niche regulation of HSC homeostasis. Manipulation of these signaling pathways and cell types may improve HSC bioengineering, which could significantly advance critical, lifesaving HSCT therapies. PMID:28830909

Induction of insulin-producing cells from human pancreatic progenitor cells.

PubMed

Noguchi, H; Naziruddin, B; Shimoda, M; Fujita, Y; Chujo, D; Takita, M; Peng, H; Sugimoto, K; Itoh, T; Tamura, Y; Olsen, G S; Kobayashi, N; Onaca, N; Hayashi, S; Levy, M F; Matsumoto, S

2010-01-01

We previously established a mouse pancreatic stem cell line without genetic manipulation. In this study, we sought to identify and isolate human pancreatic stem/progenitor cells. We also tested whether growth factors and protein transduction of pancreatic and duodenal homeobox factor-1 (PDX-1) and BETA2/NeuroD into human pancreatic stem/progenitor cells induced insulin or pancreas-related gene expressions. Human pancreata from brain-dead donors were used for islet isolation with the standard Ricordi technique modified by the Edmonton protocol. The cells from a duct-rich population were cultured in several media, based on those designed for mouse pancreatic or for human embryonic stem cells. To induce cell differentiation, cells were cultured for 2 weeks with exendin-4, nicotinamide, keratinocyte growth factor, PDX-1 protein, or BETA2/NeuroD protein. The cells in serum-free media showed morphologies similar to a mouse pancreatic stem cell line, while the cells in the medium for human embryonic stem cells formed fibroblast-like morphologies. The nucleus/cytoplasm ratios of the cells in each culture medium decreased during the culture. The cells stopped dividing after 30 days, suggesting that they had entered senescence. The cells treated with induction medium differentiated into insulin-producing cells, expressing pancreas-related genes. Duplications of cells from a duct-rich population were limited. Induction therapy with several growth factors and transduction proteins might provide a potential new strategy for induction of transplantable insulin-producing cells. Copyright 2010 Elsevier Inc. All rights reserved.

Tolerance and immunity in mice infected with herpes simplex virus: studies on the mechanism of tolerance to delayed-type hypersensitivity.

PubMed

Nash, A A; Phelan, J; Gell, P G; Wildy, P

1981-06-01

Tolerance to delayed-type hypersensitivity is produced in mice following an intravenous injection of herpes simplex virus. This form of tolerance is produced early on, following simultaneous injections of virus subcutaneously and intravenously, and is long lasting (greater than 100 days). The early tolerance mechanism is resistant to high doses of cyclophosphamide and is not transferable by serum or spleen cells taken after 7 days. However, spleen cells taken at 14 days onwards inhibit the induction of delayed hypersensitivity when transferred to normal syngeneic recipients. These cells are T lymphocytes and are specific for the herpes type used in the induction.

Tolerance and immunity in mice infected with herpes simplex virus: studies on the mechanism of tolerance to delayed-type hypersensitivity.

PubMed Central

Nash, A A; Phelan, J; Gell, P G; Wildy, P

1981-01-01

Tolerance to delayed-type hypersensitivity is produced in mice following an intravenous injection of herpes simplex virus. This form of tolerance is produced early on, following simultaneous injections of virus subcutaneously and intravenously, and is long lasting (greater than 100 days). The early tolerance mechanism is resistant to high doses of cyclophosphamide and is not transferable by serum or spleen cells taken after 7 days. However, spleen cells taken at 14 days onwards inhibit the induction of delayed hypersensitivity when transferred to normal syngeneic recipients. These cells are T lymphocytes and are specific for the herpes type used in the induction. PMID:6265348

Alloreactive Regulatory T Cells Allow the Generation of Mixed Chimerism and Transplant Tolerance.

PubMed

Ruiz, Paulina; Maldonado, Paula; Hidalgo, Yessia; Sauma, Daniela; Rosemblatt, Mario; Bono, Maria Rosa

2015-01-01

The induction of donor-specific transplant tolerance is one of the main goals of modern immunology. Establishment of a mixed chimerism state in the transplant recipient has proven to be a suitable strategy for the induction of long-term allograft tolerance; however, current experimental recipient preconditioning protocols have many side effects, and are not feasible for use in future therapies. In order to improve the current mixed chimerism induction protocols, we developed a non-myeloablative bone-marrow transplant (NM-BMT) protocol using retinoic acid (RA)-induced alloantigen-specific Tregs, clinically available immunosuppressive drugs, and lower doses of irradiation. We demonstrate that RA-induced alloantigen-specific Tregs in addition to a NM-BMT protocol generates stable mixed chimerism and induces tolerance to allogeneic secondary skin allografts in mice. Therefore, the establishment of mixed chimerism through the use of donor-specific Tregs rather than non-specific immunosuppression could have a potential use in organ transplantation.

Induction of neonatal tolerance to GFP-labeled karyocytes in C57/B6 mice.

PubMed

Dovhyi, Roman; Pishel, Iryna; Butenko, Gennadij; Skivka, Larysa

2017-08-01

Green fluorescent protein is widely used in biological studies including parabiosis models for visualization of cellular structures and cells. However, the growing number of the data is available regarding immunogenicity of this protein, which can interfere with its use in in vivo experiments. In this study, we attempted to induce neonatal immunological tolerance to GFP-labeled karyocytes by intraperitoneal injections of B6.GFP mouse splenocytes to newborn C57/B6 mice. GFP + skin graft integrity was evaluated under UV light at 6weeks after skin grafting. GFP + skin transplants survived up to 6weeks after grafting in all animals that undergone neonatal tolerance induction, whereas all skin grafts were rejected in control naïve mice within first two weeks. Thus, current protocol is suitable for induction of immune tolerance against GFP-labeled karyocytes. Copyright © 2017 Elsevier B.V. All rights reserved.

Hematopoietic cell differentiation from embryonic and induced pluripotent stem cells

PubMed Central

2013-01-01

Pluripotent stem cells, both embryonic stem cells and induced pluripotent stem cells, are undifferentiated cells that can self-renew and potentially differentiate into all hematopoietic lineages, such as hematopoietic stem cells (HSCs), hematopoietic progenitor cells and mature hematopoietic cells in the presence of a suitable culture system. Establishment of pluripotent stem cells provides a comprehensive model to study early hematopoietic development and has emerged as a powerful research tool to explore regenerative medicine. Nowadays, HSC transplantation and hematopoietic cell transfusion have successfully cured some patients, especially in malignant hematological diseases. Owing to a shortage of donors and a limited number of the cells, hematopoietic cell induction from pluripotent stem cells has been regarded as an alternative source of HSCs and mature hematopoietic cells for intended therapeutic purposes. Pluripotent stem cells are therefore extensively utilized to facilitate better understanding in hematopoietic development by recapitulating embryonic development in vivo, in which efficient strategies can be easily designed and deployed for the generation of hematopoietic lineages in vitro. We hereby review the current progress of hematopoietic cell induction from embryonic stem/induced pluripotent stem cells. PMID:23796405

Food allergen selective thermal processing regimens may change oral tolerance in infancy.

PubMed

Kosti, R I; Triga, M; Tsabouri, S; Priftis, K N

2013-01-01

Food allergy can be considered a failure in the induction of oral tolerance. Recently, great interest has been focused on understanding the mechanisms and the contributing factors of oral tolerance development, hoping for new definitive interventions in the prevention and treatment of food allergy. Given that food processing may modify the properties and the nature of dietary proteins, several food processing methods could affect the allergenicity of these proteins and consequently may favour oral tolerance induction to food allergic children. Indeed, effective thermal food processing regimens of altering food proteins to reduce allergenicity have been recently reported in the literature. This article is mainly focused on the effect of selective thermal processing regimens on the main infant allergenic foods, with a potential clinical relevance on their allergenicity and therefore on oral tolerance induction. In the light of recent findings, the acquisition of tolerance in younger age and consequently the ability of young children to "outgrow" food allergy could be achieved through the application of selective thermal processing regimens on certain allergenic foods. Therefore, the ability of processed foods to circumvent clinical disease and at the same time to have an impact on the immune system and facilitate tolerance induction could be invaluable as a component of a successful therapeutic strategy. The opening in the new avenues of research in the use of processed foods in clinical practice for the amelioration of the impact on the quality of life of patients and possibly in food allergy prevention is warranted. Copyright © 2012 SEICAP. Published by Elsevier Espana. All rights reserved.

40 CFR 180.556 - Pymetrozine; tolerances for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances... these raw agricultural commodities. Commodity Parts per million Asparagus 0.04 Brassica, head and stem...

40 CFR 180.556 - Pymetrozine; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances... these raw agricultural commodities. Commodity Parts per million Asparagus 0.04 Brassica, head and stem...

Isolation of ABA-responsive mutants in allohexaploid bread wheat (Triticum aestivum L.): Drawing connections to grain dormancy, preharvest sprouting, and drought tolerance

USDA-ARS?s Scientific Manuscript database

This paper describes the isolation of Wheat ABA-responsive mutants (Warm) in Chinese spring background of allohexaploid Triticum aestivum. The plant hormone abscisic acid (ABA) is required for the induction of seed dormancy, the induction of stomatal closure and drought tolerance, and is associated...

Depletion of CD8 Memory T Cells for Induction of Tolerance of a Previously Transplanted Kidney Allograft

PubMed Central

Koyama, I.; Nadazdin, O.; Boskovic, S.; Ochiai, T.; Smith, R. N.; Sykes, M.; Sogawa, H.; Murakami, T.; Strom, T. B.; Colvin, R. B.; Sachs, D. H.; Benichou, G.; Cosimi, A. B.; Kawai, T.

2013-01-01

Heterologous immunologic memory has been considered a potent barrier to tolerance induction in primates. Induction of such tolerance for a previously transplanted organ may be more difficult, because specific memory cells can be induced and activated by a transplanted organ. In the current study, we attempted to induce tolerance to a previously transplanted kidney allograft in nonhuman primates. The conditioning regimen consisted of low dose total body irradiation, thymic irradiation, antithymocyte globulin, and anti- CD154 antibody followed by a brief course of a calcineurin inhibitor. This regimen had been shown to induce mixed chimerism and allograft tolerance when kidney transplantation (KTx) and donor bone marrow transplantation (DBMT) were simultaneously performed. However, the same regimen failed to induce mixed chimerism when delayed DBMT was performed after KTx. We found that significant levels of memory T cells remained after conditioning, despite effective depletion of naïve T cells. By adding humanized anti-CD8 monoclonal antibody (cM-T807), CD8 memory T cells were effectively depleted and these recipients successfully achieved mixed chimerism and tolerance. The current studies provide ‘proof of principle’ that the mixed chimerism approach can induce renal allograft tolerance, even late after organ transplantation if memory T-cell function is adequately controlled. PMID:17286617

Induction of transplantation tolerance by combining non-myeloablative conditioning with delivery of alloantigen by T cells

PubMed Central

Tian, Chaorui; Yuan, Xueli; Bagley, Jessamyn; Blazar, Bruce R.; Sayegh, Mohamed H.; Iacomini, John

2008-01-01

The observation that bone marrow derived hematopoietic cells are potent inducers of tolerance has generated interest in trying to establish transplantation tolerance by inducing a state of hematopoietic chimerism through allogeneic bone marrow transplantation. However, this approach is associated with serious complications that limit its utility for tolerance induction. Here we describe the development of a novel approach that allows for tolerance induction without the need for an allogeneic bone marrow transplant by combining non-myeloablative host conditioning with delivery of donor alloantigen by adoptively transferred T cells. CBA/Ca mice were administered 2.5Gy whole body irradiation (WBI). The following day the mice received Kb disparate T cells from MHC class I transgenic CBK donor mice, as well as rapamycin on days 0–13 and anti-CD40L monoclonal antibody on days 0–5, 8,11 and 14 relative to T cell transfer. Mice treated using this approach were rendered specifically tolerant to CBK skin allografts through a mechanism involving central and peripheral deletion of alloreactive T cells. These data suggest robust tolerance can be established without the need for bone marrow transplantation using clinically relevant non-myeloablative conditioning combined with antigen delivery by T cells. PMID:18280792

PD-1 signalling in CD4+ T cells restrains their clonal expansion to an immunogenic stimulus, but is not critically required for peptide-induced tolerance

PubMed Central

Konkel, Joanne E; Frommer, Friederike; Leech, Melanie D; Yagita, Hideo; Waisman, Ari; Anderton, Stephen M

2010-01-01

The ultimate outcome of T-cell recognition of peptide–major histocompatibility complex (MHC) complexes is determined by the molecular context in which antigen presentation is provided. The paradigm is that, after exposure to peptides presented by steady-state dendritic cells (DCs), inhibitory signals dominate, leading to the deletion and/or functional inactivation of antigen-reactive T cells. This has been utilized in a variety of models providing peptide antigen in soluble form in the absence of adjuvant. A co-inhibitory molecule of considerable current interest is PD-1. Here we show that there is the opportunity for the PD-1/PD-L1 interaction to function in inhibiting the T-cell response during tolerance induction. Using traceable CD4+ T-cell receptor (TCR) transgenic cells, together with a blocking antibody to disrupt PD-1 signalling, we explored the roles of PD-1 in the induction of tolerance versus a productive immune response. Intact PD-1 signalling played a role in limiting the extent of CD4+ T-cell accumulation in response to an immunogenic stimulus. However, PD-1 signalling was not required for either the induction, or the maintenance, of peptide-induced tolerance; a conclusion underlined by successful tolerance induction in TCR transgenic cells genetically deficient for PD-1. These observations contrast with the reported requirement for PD-1 signals in CD8+ T-cell tolerance. PMID:20113370

Hemopoietic Response to Low Dose-Rates of Ionizing Radiation Shows Stem Cell Tolerance and Adaptation

PubMed Central

Fliedner, Theodor M.; Graessle, Dieter H.; Meineke, Viktor; Feinendegen, Ludwig E.

2012-01-01

Chronic exposure of mammals to low dose-rates of ionizing radiation affects proliferating cell systems as a function of both dose-rate and the total dose accumulated. The lower the dose-rate the higher needs to be the total dose for a deterministic effect, i.e., tissue reaction to appear. Stem cells provide for proliferating, maturing and functional cells. Stem cells usually are particularly radiosensitive and damage to them may propagate to cause failure of functional cells. The paper revisits 1) medical histories with emphasis on the hemopoietic system of the victims of ten accidental chronic radiation exposures, 2) published hematological findings of long-term chronically gamma-irradiated rodents, and 3) such findings in dogs chronically exposed in large life-span studies. The data are consistent with the hypothesis that hemopoietic stem and early progenitor cells have the capacity to tolerate and adapt to being repetitively hit by energy deposition events. The data are compatible with the “injured stem cell hypothesis”, stating that radiation–injured stem cells, depending on dose-rate, may continue to deliver clones of functional cells that maintain homeostasis of hemopoiesis throughout life. Further studies perhaps on separated hemopoietic stem cells may unravel the molecular-biology mechanisms causing radiation tolerance and adaptation. PMID:23304110

Quantitative analysis of antigen for the induction of tolerance in carcinoembryonic antigen transgenic mice.

PubMed Central

Hasegawa, T; Isobe, K; Nakashima, I; Shimokata, K

1992-01-01

In order to analyse the amounts of antigen in the thymus for the induction of tolerance, several carcinoembryonic antigen (CEA) transgenic lines were established which expressed human CEA antigen with different amounts. The chimeric KSN nude mice transplanted with the thymus of the B601 line (in which CEA mRNA and CEA protein could be detected in various tissues) to kidney capsule showed tolerance to human CEA. On the other hand, the chimeric KSN nude mice transplanted with the thymus of the B602 or BC60 line (in which neither CEA mRNA nor CEA protein could be detected by Northern blot analysis and flow cytometry analysis) or normal C57BL/6 (B6) did not develop the tolerance to human CEA. However, the chimeric KSN nude mice transplanted simultaneously with thymus of the B6 and spleen of the B601 line became tolerant to human CEA antigen. In the case of systemic immunization with cells which had CEA antigen, the B601 line was tolerant to human CEA. Surprisingly, the B602 and BC60 lines were also tolerant to CEA molecule. These results indicate that not only the antigen present in the thymus but also the antigen which flows from the peripheral organs to the thymus may be necessary for the induction of CEA tolerance. Images Figure 1 PMID:1493931

Is the Quantification of Antigen-Specific Basophil Activation a Useful Tool for Monitoring Oral Tolerance Induction in Children With Egg Allergy?

PubMed

Gamboa, P M; Garcia-Lirio, E; Gonzalez, C; Gonzalez, A; Martinez-Aranguren R M; Sanz María, L

2016-01-01

To assess modifications in baseline specific IgE- and anti-IgE- and antigen-specific-mediated basophil activation in egg-allergic children. The values were compared before and after the children completed specific oral tolerance induction (SOTI) with egg. We studied 28 egg-allergic children who completed SOTI with egg. The basophil activation test and specific IgE determinations with egg white, ovalbumin, and ovomucoid were performed in all 28 children. A decrease in antigen-specific activation with egg white, ovalbumin, and ovomucoid was observed only at the 2 lowest concentrations used (5 and 0.05 ng/mL). Baseline activation was higher in patients with multiple food allergies and in those who developed anaphylaxis during SOTI; this activation decreased in both groups after completion of SOTI. A significant decrease was also observed in specific IgE values for egg white, ovalbumin, and ovomucoid after tolerance induction. Food tolerance induction is a specific process for each food that can be mediated by immunologic changes such as a decrease in specific IgE values and in specific and spontaneous basophil activation.

High-dose cytarabine as salvage therapy for relapsed or refractory acute myeloid leukemia--is more better or more of the same?

PubMed

Wolach, Ofir; Itchaki, Gilad; Bar-Natan, Michal; Yeshurun, Moshe; Ram, Ron; Herscovici, Corina; Shpilberg, Ofer; Douer, Dan; Tallman, Martin S; Raanani, Pia

2016-03-01

Cytarabine is the backbone of most chemotherapeutic regimens for acute myeloid leukemia (AML), yet the optimal dose for salvage therapy of refractory or relapsed AML (RR-AML) has not been established. Very high dose single-agent cytarabine at 36 g/m(2) (ARA-36) was previously shown to be effective and tolerable in RR-AML. In this retrospective analysis, we aim to describe the toxicity and efficacy of ARA-36 as salvage therapy for patients with AML who are primary refractory to intensive daunorubicin-containing induction or those relapsing after allogeneic stem cell transplant (alloSCT). Fifteen patients, median age 53 years, were included in the analysis. Six patients were treated for induction failure, one had resistant APL, and eight relapsed after alloSCT. Complete remission was achieved in 60% of patients. Surviving patients were followed for a median of 8.5 months. One-year overall survival was 54% (95% CI 30%-86%), and relapse rate from remission (n = 9) was 56%. Grade III/IV pulmonary, infectious, ocular and gastrointestinal toxicities occurred in 26%, 20%, 20% and 20% of patients respectively. Salvage therapy with ARA-36 regimen for RR-AML has considerable efficacy with manageable toxicity in patients with induction failure or post-transplant relapse. Overall survival in these high-risk patients still remains poor. Copyright © 2015 John Wiley & Sons, Ltd.

Metabolic and enzymatic changes associated with carbon mobilization, utilization and replenishment triggered in grain amaranth (Amaranthus cruentus) in response to partial defoliation by mechanical injury or insect herbivory

PubMed Central

2012-01-01

Background Amaranthus cruentus and A. hypochondriacus are crop plants grown for grain production in subtropical countries. Recently, the generation of large-scale transcriptomic data opened the possibility to study representative genes of primary metabolism to gain a better understanding of the biochemical mechanisms underlying tolerance to defoliation in these species. A multi-level approach was followed involving gene expression analysis, enzyme activity and metabolite measurements. Results Defoliation by insect herbivory (HD) or mechanical damage (MD) led to a rapid and transient reduction of non-structural carbohydrates (NSC) in all tissues examined. This correlated with a short-term induction of foliar sucrolytic activity, differential gene expression of a vacuolar invertase and its inhibitor, and induction of a sucrose transporter gene. Leaf starch in defoliated plants correlated negatively with amylolytic activity and expression of a β-amylase-1 gene and positively with a soluble starch synthase gene. Fatty-acid accumulation in roots coincided with a high expression of a phosphoenolpyruvate/phosphate transporter gene. In all tissues there was a long-term replenishment of most metabolite pools, which allowed damaged plants to maintain unaltered growth and grain yield. Promoter analysis of ADP-glucose pyrophosphorylase and vacuolar invertase genes indicated the presence of cis-regulatory elements that supported their responsiveness to defoliation. HD and MD had differential effects on transcripts, enzyme activities and metabolites. However, the correlation between transcript abundance and enzymatic activities was very limited. A better correlation was found between enzymes, metabolite levels and growth and reproductive parameters. Conclusions It is concluded that a rapid reduction of NSC reserves in leaves, stems and roots followed by their long-term recovery underlies tolerance to defoliation in grain amaranth. This requires the coordinate action of genes/enzymes that are differentially affected by the way leaf damage is performed. Defoliation tolerance in grain is a complex process that can’t be fully explained at the transcriptomic level only. PMID:22966837

40 CFR 180.291 - Pentachloronitrobenzene; tolerance for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances... per million Bean 0.1 Brassica, head and stem, subgroup 5A 0.1 Cotton, undelinted seed 0.1 Garlic, bulb...

40 CFR 180.291 - Pentachloronitrobenzene; tolerance for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances... per million Bean 0.1 Brassica, head and stem, subgroup 5A 0.1 Cotton, undelinted seed 0.1 Garlic, bulb...

Specific oral tolerance induction in childhood.

PubMed

Peters, Rachel L; Dang, Thanh D; Allen, Katrina J

2016-12-01

Food allergy continues to be a significant public health concern for which there are no approved treatments and management strategies primarily include allergen avoidance and pharmacological measures for accidental exposures. Food allergy is thought to result from either a failure to establish oral tolerance or the breakdown of existing oral tolerance, and therefore, experimental preventative and treatment strategies are now aimed at inducing specific oral tolerance. This may occur in infancy prior to the development of food allergy through the optimal timing of dietary exposure (primary oral tolerance induction) or as a treatment for established food allergy through oral immunotherapy (secondary oral tolerance induction). Trials examining the effectiveness of early dietary allergen exposure to prevent food allergy have yielded promising results for peanut allergy but not so for other allergens, although the results of several trials are yet to be published. Although infant feeding guidelines no longer advise to avoid allergenic foods and exposure to food allergens orally is an important step in inducing food tolerance by the immune system, evidence regarding the optimal timing, dose and form of these foods into the infant's diet is lacking. Likewise, oral immunotherapy trials appear promising for inducing desensitization; however, the long-term efficacy in achieving sustained desensitization and optimal protocols to achieve this is unknown. More research is needed in this emerging field. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[Osteogenic potential of bone marrow mesenchymal stem cells from ovariectomied osteoporotic rat].

PubMed

Li, Dong-ju; Ge, Dong-xia; Wu, Wen-chao; Wu, Jiang; Li, Liang

2005-05-01

To investigate the difference of osteogenic potential of bone marrow mesenchymal stem cells (MSCs) between healthy rats and osteoporotic rats. We established the animal model of osteoporosis by performing ovariectom on the 3-month-old female Sprague-Dawley rats. Bone marrow mesenchymal stem cells(MSCs) were isolated from the rats of control group and of ovariectomized (ovx) group by means of the density-gradient centrifugation method, and the 3rd-4th passage MSCs were used in all the experiments. The experiments comprised 4 groups: (1) Marrow mesenchymal stem cells control group (MSCs control group); (2) Marrow mesenchymal stem cells ovx group (MSCs ovx group); (3) Osteogenesis induction control group (OSI control group); (4) Osteogenesis induction ovx group (OSI ovx group). Cell cycle and proliferation index (PI) of MSCs were detected by flow cytometry. The expression of alkaline phosphatase (ALP) was detected by dynamics method with substrate of phosphoric acid para-Nitro benzene. The levels of osteocalcin were detected with the isotope labelling method. (1) PI of MSCs was lower in MSCs ovx group than in MSCs control group. (2) The expression of alkaline phosphatase (ALP) was much higher in OSI control group than in the MSCs control group; the expression of alkaline phosphatase (ALP) was much higher in the OSI control group than in OSI ovx group after 7-day and 14-day osteogenic induction. (3) The level of osteocalcin was much higher in the OSI control group than in the MSCs control group after 14-day, 21-day, 28-day osteogenic induction. The level of osteocalcin was much higher in the OSI control group than in the OSI ovx group. Both the proliferative potential and the osteogenic potential of bone marrow mesenchymal stem cells (MSCs) from the ovariectomized osteoporotic rat are decreased.

Induction of endoplasmic reticulum stress under endotoxin tolerance increases inflammatory responses and decreases Pseudomonas aeruginosa pneumonia.

PubMed

Kim, Sena; Joe, Yeonsoo; Park, Se-Ung; Jeong, Sun Oh; Kim, Jin-Kyung; Park, Seong Hoon; Pae, Hyun-Ock; Surh, Young-Joon; Shin, Jaekyoon; Chung, Hun Taeg

2018-06-20

Endotoxin tolerance develops in the late phase of sepsis to protect cells from an early hyperinflammatory response. Nonetheless, because it induces an immunosuppressive environment, patients with sepsis in its late phase are affected by secondary infections, particularly bacterial pneumonia. Here, we showed that induction of endoplasmic reticulum (ER) stress leads to activation of glycogen synthase kinase 3β (GSK-3β) and X-box-binding protein 1 (XBP-1) in an inositol-requiring enzyme 1α (IRE1α)-mediated manner, which in turn restores the inflammatory response in endotoxin-tolerant macrophages. Animal and in vitro models of endotoxin tolerance were studied along with a model of LPS-induced endotoxin tolerance and a model of cecal ligation and puncture (CLP)-induced endotoxin tolerance. To detect the suppressed inflammatory response during endotoxin tolerance, inflammatory-cytokine expression levels were measured by quantitative real-time PCR and an ELISA. Our research revealed that induction of ER stress alleviated lung injury in a septic host infected with Pseudomonas aeruginosa via the activation of GSK-3β and XBP-1 in an IRE1α-mediated manner. Consequently, in the lungs of the septic host infected with P. aeruginosa, symptoms of pneumonia improved and the infecting bacteria were cleared. Thus, for septic patients, determination of immune status may guide the selection of appropriate immunomodulation, and ER stress can be a novel therapeutic strategy restoring the immune response in patients with endotoxin tolerance. ©2018 Society for Leukocyte Biology.

Dual specific oral tolerance induction using interferon gamma for IgE-mediated anaphylactic food allergy and the dissociation of local skin allergy and systemic oral allergy: tolerance or desensitization?

PubMed

Noh, G; Jang, E H

2014-01-01

Specific oral tolerance induction (SOTI) for IgE-mediated food allergy (IFA) can be successfully achieved using interfero gamma (classic SOTI). In this study, a tolerable dose was introduced during tolerance induction with interferon gamma (dual SOTI), and its effectiveness was evaluated. The study population comprised 25 IFA patients. Blood samples were taken for analysis, including complete blood count with differential counts of eosinophils, serum total IgE levels, and specific IgE for allergenic foods. Skin prick tests were conducted with the allergens. Oral food challenges were performed to diagnose IFA. Ten patients received dual SOTI, 5 received classic SOTI, 5 received SOTI without interferon gamma (original SOTI), and 5 were not treated (controls). Patients treated with dual SOTI and classic SOTI using interferon gamma became tolerant to the allergenic food. The tolerable dose was introduced successfully in dual SOTI. It was difficult to proceed with the same dosing protocol used for classic SOTI in cases treated with original SOTI. Following dual SOTI, the systemic reaction to oral intake subsided, but the local skin reaction to contact with the allergenic food persisted. Dual SOTI is an improved protocol for SOTI using interferon gamma for IFA.The local skin reaction and systemic reaction to oral intake were dissociated following dual SOTI. In cases of food allergy, tolerance appears to result from desensitization to allergens.

40 CFR 180.498 - Sulfentrazone; tolerances for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances... Parts per million Asparagus 0.15 Bean, lima, succulent 0.15 Brassica, head and stem, subgroup 5A 0.20... pesticide under section 18 emergency exemptions granted by EPA. Compliance with the tolerance levels...

Laminins affect T cell trafficking and allograft fate

PubMed Central

Warren, Kristi J.; Iwami, Daiki; Harris, Donald G.; Bromberg, Jonathan S.; Burrell, Bryna E.

2014-01-01

Lymph nodes (LNs) are integral sites for the generation of immune tolerance, migration of CD4+ T cells, and induction of Tregs. Despite the importance of LNs in regulation of inflammatory responses, the LN-specific factors that regulate T cell migration and the precise LN structural domains in which differentiation occurs remain undefined. Using intravital and fluorescent microscopy, we found that alloreactive T cells traffic distinctly into the tolerant LN and colocalize in exclusive regions with alloantigen-presenting cells, a process required for Treg induction. Extracellular matrix proteins, including those of the laminin family, formed regions within the LN that were permissive for colocalization of alloantigen-presenting cells, alloreactive T cells, and Tregs. We identified unique expression patterns of laminin proteins in high endothelial venule basement membranes and the cortical ridge that correlated with alloantigen-specific immunity or immune tolerance. The ratio of laminin α4 to laminin α5 was greater in domains within tolerant LNs, compared with immune LNs, and blocking laminin α4 function or inducing laminin α5 overexpression disrupted T cell and DC localization and transmigration through tolerant LNs. Furthermore, reducing α4 laminin circumvented tolerance induction and induced cardiac allograft inflammation and rejection in murine models. This work identifies laminins as potential targets for immune modulation. PMID:24691446

Differentiation of Human Dental Stem Cells Reveal a Role for microRNA-218

PubMed Central

Gay, Isabel; Cavender, Adriana; Peto, David; Sun, Zhao; Speer, Aline; Cao, Huojun; Amendt, Brad A.

2013-01-01

Background Regeneration of the lost periodontium is the ultimate goal of periodontal therapy. Advances in tissue engineering have demonstrated the multilineage potential and plasticity of adult stem cells located in the periodontal apparatus. However, it remains unclear how epigenetic mechanisms controlling signals determine tissue specification and cell lineage decisions. To date, no data is available on micro-RNAs (miRNAs) activity behind human-derived dental stem cells. Methods In this study, we isolated periodontal ligament stem cells (PDLSCs), dental pulp stem cells (DPSCs), and gingival stem cells (GSCs) from extracted third molars; human bone marrow stem cells (BMSCs) were used as a positive control. The expression of OCT4A and NANOG was confirmed in these undifferentiated cells. All cells were cultured under osteogenic inductive conditions and RUNX2 expression was analyzed as a marker of mineralized tissue differentiation. A miRNA expression profile was obtained at baseline and after osteogenic induction in all cell types. Results RUNX2 expression demonstrated the successful osteogenic induction of all cell types, which was confirmed by alizarin red stain. The analysis of 765 miRNAs demonstrated a shift in miRNA expression occurred in all four stem cell types, including a decrease in hsa-mir-218 across all differentiated cell populations. Hsa-mir-218 targets RUNX2 and decreases RUNX2 expression in undifferentiated human dental stem cells (DSCs). DSC mineralized tissue type differentiation is associated with a decrease in hsa-mir-218 expression. Conclusions These data reveal a miRNA regulated pathway for the differentiation of human DSCs and a select network of human microRNAs that control DSC osteogenic differentiation. PMID:23662917

IL-6 inhibits upregulation of membrane-bound TGF-beta 1 on CD4+ T cells and blocking IL-6 enhances oral tolerance

PubMed Central

Kuhn, Chantal; Rezende, Rafael Machado; M'Hamdi, Hanane; da Cunha, Andre Pires; Weiner, Howard L.

2016-01-01

Oral administration of antigen induces regulatory T cells that express latent membrane-bound TGF-beta (LAP) and that have been shown to play an important role in the induction of oral tolerance. We developed an in vitro model to study modulation of LAP+ on CD4+ T cells. The combination of anti-CD3 mAb, anti-CD28 mAb and recombinant IL-2 induced expression of LAP on naïve CD4+ T cells, independent of FoxP3 or exogenous TGF-β. In vitro generated CD4+LAP+FoxP3− T cells were suppressive in vitro, inhibiting proliferation of naïve CD4+ T cells and IL-17A secretion by Th17 cells. Assessing the impact of different cytokines and neutralizing antibodies against cytokines we found that LAP induction was decreased in the presence of IL-6 and IL-21, and to a lesser extent by IL-4 and TNFα. IL-6 abrogated the in vitro induction of CD4+LAP+ T cells by STAT3 dependent inhibition of Lrrc32 (GARP), the adapter protein that tethers TGF-beta to the membrane. Oral tolerance induction was enhanced in mice lacking expression of IL-6R by CD4+ T cells and by treatment of wild-type mice with neutralizing anti-IL-6 mAb. These results suggest that pro-inflammatory cytokines interfere with oral tolerance induction and that blocking the IL-6 pathway is a potential strategy for enhancing oral tolerance in the setting of autoimmune and inflammatory diseases. PMID:28039301

IL-6 Inhibits Upregulation of Membrane-Bound TGF-β 1 on CD4+ T Cells and Blocking IL-6 Enhances Oral Tolerance.

PubMed

Kuhn, Chantal; Rezende, Rafael Machado; M'Hamdi, Hanane; da Cunha, Andre Pires; Weiner, Howard L

2017-02-01

Oral administration of Ag induces regulatory T cells that express latent membrane-bound TGF-β (latency-associated peptide [LAP]) and have been shown to play an important role in the induction of oral tolerance. We developed an in vitro model to study modulation of LAP + on CD4 + T cells. The combination of anti-CD3 mAb, anti-CD28 mAb, and recombinant IL-2 induced expression of LAP on naive CD4 + T cells, independent of Foxp3 or exogenous TGF-β. In vitro generated CD4 + LAP + Foxp3 - T cells were suppressive in vitro, inhibiting proliferation of naive CD4 + T cells and IL-17A secretion by Th17 cells. Assessing the impact of different cytokines and neutralizing Abs against cytokines, we found that LAP induction was decreased in the presence of IL-6 and IL-21, and to a lesser extent by IL-4 and TNF-α. IL-6 abrogated the in vitro induction of CD4 + LAP + T cells by STAT3-dependent inhibition of Lrrc32 (glycoprotein A repetitions predominant [GARP]), the adapter protein that tethers TGF-β to the membrane. Oral tolerance induction was enhanced in mice lacking expression of IL-6R by CD4 + T cells and by treatment of wild-type mice with neutralizing anti-IL-6 mAb. These results suggest that proinflammatory cytokines interfere with oral tolerance induction and that blocking the IL-6 pathway is a potential strategy for enhancing oral tolerance in the setting of autoimmune and inflammatory diseases. Copyright © 2017 by The American Association of Immunologists, Inc.

Heart grafts tolerized through third-party multipotent adult progenitor cells can be retransplanted to secondary hosts with no immunosuppression.

PubMed

Eggenhofer, Elke; Popp, Felix C; Mendicino, Michael; Silber, Paula; Van't Hof, Wouter; Renner, Philipp; Hoogduijn, Martin J; Pinxteren, Jef; van Rooijen, Nico; Geissler, Edward K; Deans, Robert; Schlitt, Hans J; Dahlke, Marc H

2013-08-01

Multipotent adult progenitor cells (MAPCs) are an adherent stem cell population that belongs to the mesenchymal-type progenitor cell family. Although MAPCs are emerging as candidate agents for immunomodulation after solid organ transplantation, their value requires further validation in a clinically relevant cell therapy model using an organ donor- and organ recipient-independent, third-party cell product. We report that stable allograft survival can be achieved following third-party MAPC infusion in a rat model of fully allogeneic, heterotopic heart transplantation. Furthermore, long-term accepted heart grafts recovered from MAPC-treated animals can be successfully retransplanted to naïve animals without additional immunosuppression. This prolongation of MAPC-mediated allograft acceptance depends upon a myeloid cell population since depletion of macrophages by clodronate abrogates the tolerogenic MAPC effect. We also show that MAPC-mediated allograft acceptance differs mechanistically from drug-induced tolerance regarding marker gene expression, T regulatory cell induction, retransplantability, and macrophage dependence. MAPC-based immunomodulation represents a promising pathway for clinical immunotherapy that has led us to initiate a phase I clinical trial for testing safety and feasibility of third-party MAPC therapy after liver transplantation.

Solid-stemmed spring wheat cultivars give better androgenic response than hollow-stemmed cultivars in anther culture.

PubMed

Weigt, Dorota; Kiel, Angelika; Nawracała, Jerzy; Pluta, Mateusz; Łacka, Agnieszka

2016-01-01

Solid-stemmed spring wheat cultivars ( Triticum aestivum L.) are resistant to the stem sawfly ( Cephus cinctus Nort.) and lodging. Anthers of 24 spring wheat cultivars with varying content of pith in the stem were used in the experiment. All were classified into three groups: solid, medium-solid and hollow stems. There was considerable influence of the cultivar on callus formation and green plant regeneration. The highest efficiency of green plant regeneration (24%) was observed for the solid-stemmed AC Abbey cultivar. There was no regeneration from the explants of four cultivars: CLTR 7027, Alentejano, Marquis and Bombona. Principal component analysis showed no differences between the cases under observation (callus induction and green plant regeneration) in their response to pre-treatment temperatures (4 and 8°C). The examination of the effects of various auxin types in the induction medium on callus formation and green plant regeneration revealed that the strongest stimulation of these processes was observed in the C17 medium with 2,4-D and dicamba. The efficiency of callus formation and green plant regeneration was greater in solid-stemmed cultivars than in hollow-stemmed cultivars.

The Role of Epithelial-Mesenchymal Transition in the Formation of Normal and Neoplastic Mammary Epithelial Stem Cells

DTIC Science & Technology

2011-09-01

separating stem cell and non- stem cell populations of normal and breast cancer cells and identified EMT transcription factors most likely involved in... stem cell biology. Preliminary results directly demonstrate that transient induction of EMT increases the number of mammary epithelial stem cells...EMT and entrance into a stem - cell state. The outcome of these experiments holds important implications for the mechanisms controlling the formation of

Xylem structure of four grape varieties and 12 alternative hosts to the xylem-limited bacterium Xylella fastidious

PubMed Central

Chatelet, David S.; Wistrom, Christina M.; Purcell, Alexander H.; Rost, Thomas L.; Matthews, Mark A.

2011-01-01

Background and Aims The bacterium Xylella fastidiosa (Xf), responsible for Pierce's disease (PD) of grapevine, colonizes the xylem conduits of vines, ultimately killing the plant. However, Vitis vinifera grapevine varieties differ in their susceptibility to Xf and numerous other plant species tolerate Xf populations without showing symptoms. The aim of this study was to examine the xylem structure of grapevines with different susceptibilities to Xf infection, as well as the xylem structure of non-grape plant species that support or limit movement of Xf to determine if anatomical differences might explain some of the differences in susceptibility to Xf. Methods Air and paint were introduced into leaves and stems to examine the connectivity between stem and leaves and the length distribution of their vessels. Leaf petiole and stem anatomies were studied to determine the basis for the free or restricted movement of Xf into the plant. Key Results There were no obvious differences in stem or petiole vascular anatomy among the grape varieties examined, nor among the other plant species that would explain differences in resistance to Xf. Among grape varieties, the more tolerant ‘Sylvaner’ had smaller stem vessel diameters and 20 % more parenchyma rays than the other three varieties. Alternative hosts supporting Xf movement had slightly longer open xylem conduits within leaves, and more connection between stem and leaves, when compared with alternative hosts that limit Xf movement. Conclusions Stem–leaf connectivity via open xylem conduits and vessel length is not responsible for differences in PD tolerance among grape varieties, or for limiting bacterial movement in the tolerant plant species. However, it was found that tolerant host plants had narrower vessels and more parenchyma rays, possibly restricting bacterial movement at the level of the vessels. The implications of xylem structure and connectivity for the means and regulation of bacterial movement are discussed. PMID:21546428

Contrasting submergence tolerance in two species of stem-succulent halophytes is not determined by differences in stem internal oxygen dynamics.

PubMed

Konnerup, Dennis; Moir-Barnetson, Louis; Pedersen, Ole; Veneklaas, Erik J; Colmer, Timothy D

2015-02-01

Many stem-succulent halophytes experience regular or episodic flooding events, which may compromise gas exchange and reduce survival rates. This study assesses submergence tolerance, gas exchange and tissue oxygen (O2) status of two stem-succulent halophytes with different stem diameters and from different elevations of an inland marsh. Responses to complete submergence in terms of stem internal O2 dynamics, photosynthesis and respiration were studied for the two halophytic stem-succulents Tecticornia auriculata and T. medusa. Plants were submerged in a glasshouse experiment for 3, 6 and 12 d and O2 levels within stems were measured with microelectrodes. Photosynthesis by stems in air after de-submergence was also measured. Tecticornia medusa showed 100 % survival in all submergence durations whereas T. auriculata did not survive longer than 6 d of submergence. O2 profiles and time traces showed that when submerged in water at air-equilibrium, the thicker stems of T. medusa were severely hypoxic (close to anoxic) when in darkness, whereas the smaller diameter stems of T. auriculata were moderately hypoxic. During light periods, underwater photosynthesis increased the internal O2 concentrations in the succulent stems of both species. Stems of T. auriculata temporally retained a gas film when first submerged, whereas T. medusa did not. The lower O2 in T. medusa than in T. auriculata when submerged in darkness was largely attributed to a less permeable epidermis. The submergence sensitivity of T. auriculata was associated with swelling and rupturing of the succulent stem tissues, which did not occur in T. medusa. The higher submergence tolerance of T. medusa was not associated with better internal aeration of stems. Rather, this species has poor internal aeration of the succulent stems due to its less permeable epidermis; the low epidermal permeability might be related to resistance to swelling of succulent stem tissues when submerged. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

TOOTH (The Open study Of dental pulp stem cell Therapy in Humans): Study protocol for evaluating safety and feasibility of autologous human adult dental pulp stem cell therapy in patients with chronic disability after stroke.

PubMed

Nagpal, Anjali; Kremer, Karlea L; Hamilton-Bruce, Monica A; Kaidonis, Xenia; Milton, Austin G; Levi, Christopher; Shi, Songtao; Carey, Leeanne; Hillier, Susan; Rose, Miranda; Zacest, Andrew; Takhar, Parabjit; Koblar, Simon A

2016-07-01

Stroke represents a significant global disease burden. As of 2015, there is no chemical or biological therapy proven to actively enhance neurological recovery during the chronic phase post-stroke. Globally, cell-based therapy in stroke is at the stage of clinical translation and may improve neurological function through various mechanisms such as neural replacement, neuroprotection, angiogenesis, immuno-modulation, and neuroplasticity. Preclinical evidence in a rodent model of middle cerebral artery ischemic stroke as reported in four independent studies indicates improvement in neurobehavioral function with adult human dental pulp stem cell therapy. Human adult dental pulp stem cells present an exciting potential therapeutic option for improving post-stroke disability. TOOTH (The Open study Of dental pulp stem cell Therapy in Humans) will investigate the use of autologous stem cell therapy for stroke survivors with chronic disability, with the following objectives: (a) determine the maximum tolerable dose of autologous dental pulp stem cell therapy; (b) define that dental pulp stem cell therapy at the maximum tolerable dose is safe and feasible in chronic stroke; and (c) estimate the parameters of efficacy required to design a future Phase 2/3 clinical trial. TOOTH is a Phase 1, open-label, single-blinded clinical trial with a pragmatic design that comprises three stages: Stage 1 will involve the selection of 27 participants with middle cerebral artery ischemic stroke and the commencement of autologous dental pulp stem cell isolation, growth, and testing in sequential cohorts (n = 3). Stage 2 will involve the transplantation of dental pulp stem cell in each cohort of participants with an ascending dose and subsequent observation for a 6-month period for any dental pulp stem cell-related adverse events. Stage 3 will investigate the neurosurgical intervention of the maximum tolerable dose of autologous dental pulp stem cell followed by 9 weeks of intensive task-specific rehabilitation. Advanced magnetic resonance and positron emission tomography neuro-imaging, and clinical assessment will be employed to probe any change afforded by stem cell therapy in combination with rehabilitation. Nine participants will step-wise progress in Stage 2 to a dose of up to 10 million dental pulp stem cell, employing a cumulative 3 + 3 statistical design with low starting stem cell dose and subsequent dose escalation, assuming that an acceptable probability of dose-limiting complications is between 1 in 6 (17%) and 1 in 3 (33%) of patients. In Stage 3, another 18 participants will receive an intracranial injection with the maximum tolerable dose of dental pulp stem cell. The primary outcomes to be measured are safety and feasibility of intracranial administration of autologous human adult DPSC in patients with chronic stroke and determination of the maximum tolerable dose in human subjects. Secondary outcomes include estimation of the measures of effectiveness required to design a future Phase 2/3 clinical trial. © 2016 World Stroke Organization.

The PAWS and STEM reliability analysis programs

NASA Technical Reports Server (NTRS)

Butler, Ricky W.; Stevenson, Philip H.

1988-01-01

The PAWS and STEM programs are new design/validation tools. These programs provide a flexible, user-friendly, language-based interface for the input of Markov models describing the behavior of fault-tolerant computer systems. These programs produce exact solutions of the probability of system failure and provide a conservative estimate of the number of significant digits in the solution. PAWS uses a Pade approximation as a solution technique; STEM uses a Taylor series as a solution technique. Both programs have the capability to solve numerically stiff models. PAWS and STEM possess complementary properties with regard to their input space; and, an additional strength of these programs is that they accept input compatible with the SURE program. If used in conjunction with SURE, PAWS and STEM provide a powerful suite of programs to analyze the reliability of fault-tolerant computer systems.

Buprenorphine dose induction in non-opioid-tolerant pre-release prisoners.

PubMed

Vocci, Frank J; Schwartz, Robert P; Wilson, Monique E; Gordon, Michael S; Kinlock, Timothy W; Fitzgerald, Terrence T; O'Grady, Kevin E; Jaffe, Jerome H

2015-11-01

In a previously reported randomized controlled trial, formerly opioid-dependent prisoners were more likely to enter community drug abuse treatment when they were inducted in prison onto buprenorphine/naloxone (hereafter called buprenorphine) than when they received counseling without buprenorphine in prison (47.5% vs. 33.7%, p=0.012) (Gordon et al., 2014). In this communication we report on the results of the induction schedule and the adverse event profile seen in pre-release prisoners inducted onto buprenorphine. This paper examines the dose induction procedure, a comparison of the proposed versus actual doses given per week, and side effects reported for 104 adult participants who were randomized to buprenorphine treatment in prison. Self-reported side effects were analyzed using generalized estimated equations to determine changes over time in side effects. Study participants were inducted onto buprenorphine at a rate faster than the induction schedule. Of the 104 (72 males, 32 females) buprenorphine recipients, 64 (37 males, 27 females) remained on medication at release from prison. Nine participants (8.6%) discontinued buprenorphine because of unpleasant opioid side effects. There were no serious adverse events reported during the in-prison phase of the study. Constipation was the most frequent symptom reported (69 percent). Our findings suggest that buprenorphine administered to non-opioid-tolerant adults should be started at a lower, individualized dose than customarily used for adults actively using opioids, and that non-opioid-tolerant pre-release prisoners can be successfully inducted onto therapeutic doses prior to release. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Defined three-dimensional culture conditions mediate efficient induction of definitive endoderm lineage from human umbilical cord Wharton's jelly mesenchymal stem cells.

PubMed

Al Madhoun, Ashraf; Ali, Hamad; AlKandari, Sarah; Atizado, Valerie Lopez; Akhter, Nadeem; Al-Mulla, Fahd; Atari, Maher

2016-11-16

Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) are gaining increasing interest as an alternative source of stem cells for regenerative medicine applications. Definitive endoderm (DE) specification is a prerequisite for the development of vital organs such as liver and pancreas. Hence, efficient induction of the DE lineage from stem cells is crucial for subsequent generation of clinically relevant cell types. Here we present a defined 3D differentiation protocol of WJ-MSCs into DE cells. WJ-MSCs were cultured in suspension to generate spheroids, about 1500 cells each, for 7 days. The serum-free differentiation media contained specific growth factors, cytokines, and small molecules that specifically regulate signaling pathways including sonic hedgehog, bone morphogenetic protein, Activin/Wnt, and Notch. We obtained more than 85 % DE cells as shown with FACS analysis using antibodies directed against the DE marker CXCR4. In addition, biochemical and molecular analysis of bona-fide DE markers revealed a time-course induction of Sox17, CXCR4, and FoxA2. Focused PCR-based array also indicated a specific induction into the DE lineage. In this study, we report an efficient serum-free protocol to differentiate WJ-MSCs into DE cells utilizing 3D spheroid formation. Our approach might aid in the development of new protocols to obtain DE-derivative lineages including liver-like and pancreatic insulin-producing cells.

Role of Maternal Dietary Peanut Exposure in Development of Food Allergy and Oral Tolerance.

PubMed

Järvinen, Kirsi M; Westfall, Jennifer; De Jesus, Magdia; Mantis, Nicholas J; Carroll, Jessica A; Metzger, Dennis W; Sampson, Hugh A; Berin, M Cecilia

2015-01-01

The impact of maternal ingestion of peanut during pregnancy and lactation on an offspring's risk for peanut allergy is under debate. To investigate the influence of maternal dietary peanut exposure and breast milk on an offspring's allergy risk. Preconceptionally peanut-exposed C3H/HeJ females were either fed or not fed peanut during pregnancy and lactation. The offsprings' responses to peanut sensitization or oral tolerance induction by feeding antigen prior to immunization were assessed. We also assessed the impact of immune murine milk on tolerance induction pre- or post-weaning. For antigen uptake studies, mice were gavaged with fluorescent peanut in the presence or absence of immune murine milk; Peyer's patches were harvested for immunostaining. Preconceptional peanut exposure resulted in the production of varying levels of maternal antibodies in serum (and breast milk), which were transferred to the offspring. Despite this, maternal peanut exposure either preconceptionally or during pregnancy and lactation, when compared to no maternal exposure, had no impact on peanut allergy. When offspring were fed peanut directly, dose-dependent tolerance induction, unaltered by maternal feeding of peanut, was seen. Although peanut uptake into the gut-associated lymphoid tissues was enhanced by immune milk as compared to naïve milk, tolerance induction was not affected by the co-administration of immune milk either pre- or post-weaning. Maternal peanut exposure during pregnancy and lactation has no impact on the development of peanut allergy in the offspring. Tolerance to peanut can be induced early, even pre-weaning, by giving moderate amounts of peanut directly to the infant, and this is neither enhanced nor impaired by concurrent exposure to immune milk.

Foxp3 Expression is Required for the Induction of Therapeutic Tissue Tolerance1

PubMed Central

Regateiro, Frederico S.; Chen, Ye; Kendal, Adrian R.; Hilbrands, Robert; Adams, Elizabeth; Cobbold, Stephen P.; Ma, Jianbo; Andersen, Kristian G.; Betz, Alexander G.; Zhang, Mindy; Madhiwalla, Shruti; Roberts, Bruce; Waldmann, Herman; Nolan, Kathleen F.; Howie, Duncan

2012-01-01

CD4+Foxp3+ Treg are essential for immune homeostasis and maintenance of self-tolerance. They are produced in the thymus and also generated de novo in the periphery in a TGFβ dependent manner. Foxp3+ Treg are also required to achieve tolerance to transplanted tissues when induced by co receptor or co stimulation blockade. Using TCR transgenic mice to avoid issues of autoimmune pathology, we show that Foxp3 expression is both necessary and sufficient for tissue tolerance by coreceptor blockade. Moreover, the known need in tolerance induction for TGFβ signalling to T cells can wholly be explained by its role in induction of Foxp3, as such signalling proved dispensable for the suppressive process. We analysed the relative contribution of TGFβ and Foxp3 to the transcriptome of TGFβ-induced Treg and showed that TGFβ elicited a large set of down-regulated signature genes. The number of genes uniquely modulated due to the influence of Foxp3 alone was surprisingly limited. Thus, despite the large genetic influence of TGFβ exposure on iTreg, the crucial Foxp3-influenced signature independent of TGFβ is small. Retroviral mediated conditional nuclear expression of Foxp3 proved sufficient to confer transplant-suppressive potency on CD4+ T cells, and was lost once nuclear Foxp3 expression was extinguished. These data support a dual role for TGFβ and Foxp3 in induced tolerance, where TGFβ stimulates Foxp3 expression, whose sustained expression is then associated with acquisition of tolerance. PMID:22988034

Aminoethyl nitrate – the novel super nitrate?

PubMed Central

Bauersachs, Johann

2009-01-01

Long-term use of most organic nitrates is limited by development of tolerance, induction of oxidative stress and endothelial dysfunction. In this issue of the BJP, Schuhmacher et al. characterized a novel class of organic nitrates with amino moieties (aminoalkyl nitrates). Aminoethyl nitrate was identified as a novel organic mononitrate with high potency but devoid of induction of mitochondrial oxidative stress. Cross-tolerance to nitroglycerin or the endothelium-dependent agonist acetylcholine after in vivo treatment was not observed. Like all nitrates, aminoethyl nitrate induced vasorelaxation by activation of soluble guanylate cyclase. Thus, in contrast to the prevailing view, high potency in an organic nitrate is not necessarily accompanied by induction of oxidative stress or endothelial dysfunction. This work from Daiber's group is an important step forward in the understanding of nitrate bioactivation, tolerance phenomena and towards the development of better organic nitrates for clinical use. PMID:19732062

[Embryonic stem cells - a scientific by-product of the assisted reproduction technology?].

PubMed

Sterthaus, Oliver; Zhang, Hong; De Geyter, Christian

2009-12-01

The differentiation potential of embryonic stem (ES) cells seems to be higher when compared to adult stem cells, which mainly differentiate into certain tissue types only. ES cells have the potential to play an important role in regenerative medicine as demonstrated with murine ES cells. However, with human embryonic stem cells (hESC) several obstacles still have to be overcome, when these are to be used in clinical applications. The expansion of hESC, safety issues as well as the immune-tolerance after transplantation are all problems that still have to be solved. Since 2005 the derivation of hESC lines from super-numerous embryos has become permitted in Switzerland, albeit under strictly restrictive guidelines. In 2008 the Basler hESC laboratory was successful in derivating the first hESC line with a normal chromosome complement in Switzerland (CHES2). Now, new applications allow the personalized establishment of immune-tolerant stem cells, which lead to the replacement of therapeutic cloning by induced pluripotent stem cells (iPS).

Stem carbohydrate dynamics and expression of genes involved in fructan accumulation and remobilization during grain growth in wheat (Triticum aestivum L.) genotypes with contrasting tolerance to water stress.

PubMed

Yáñez, Alejandra; Tapia, Gerardo; Guerra, Fernando; Del Pozo, Alejandro

2017-01-01

The genetic and physiological mechanisms underlying the relationship between water-soluble carbohydrates (WSC) and water stress tolerance are scarcely known. This study aimed to evaluate the main WSC in stems, and the expression of genes involved in fructan metabolism in wheat genotypes growing in a glasshouse with water stress (WS; 50% field capacity from heading) and full irrigation (FI; 100% field capacity). Eight wheat genotypes (five tolerant and three susceptible to water stress) were evaluated initially (experiment 1) and the two most contrasting genotypes in terms of WSC accumulation were evaluated in a subsequent experiment (experiment 2). Maximum accumulation of WSC occurred 10-20 days after anthesis. Under WS, the stress-tolerant genotype exhibited higher concentrations of WSC, glucose, fructose and fructan in the stems, compared to FI. In addition, the stress-tolerant genotype exhibited higher up-regulation of the fructan 1-fructosyltransferase B (1-FFTB) and fructan 1-exohydrolase w2 (1-FEHw2) genes, whereas the susceptible cultivar presented an up-regulation of the fructan 6-fructosyltransferase (6-SFT) and fructan 1-exohydrolase w3 (1-FEHw3) genes. Our results indicated clear differences in the pattern of WSC accumulation and the expression of genes regulating fructan metabolism between the tolerant and susceptible genotypes under WS.

Stem carbohydrate dynamics and expression of genes involved in fructan accumulation and remobilization during grain growth in wheat (Triticum aestivum L.) genotypes with contrasting tolerance to water stress

PubMed Central

Yáñez, Alejandra; Tapia, Gerardo; Guerra, Fernando

2017-01-01

The genetic and physiological mechanisms underlying the relationship between water-soluble carbohydrates (WSC) and water stress tolerance are scarcely known. This study aimed to evaluate the main WSC in stems, and the expression of genes involved in fructan metabolism in wheat genotypes growing in a glasshouse with water stress (WS; 50% field capacity from heading) and full irrigation (FI; 100% field capacity). Eight wheat genotypes (five tolerant and three susceptible to water stress) were evaluated initially (experiment 1) and the two most contrasting genotypes in terms of WSC accumulation were evaluated in a subsequent experiment (experiment 2). Maximum accumulation of WSC occurred 10–20 days after anthesis. Under WS, the stress-tolerant genotype exhibited higher concentrations of WSC, glucose, fructose and fructan in the stems, compared to FI. In addition, the stress-tolerant genotype exhibited higher up-regulation of the fructan 1-fructosyltransferase B (1-FFTB) and fructan 1-exohydrolase w2 (1-FEHw2) genes, whereas the susceptible cultivar presented an up-regulation of the fructan 6-fructosyltransferase (6-SFT) and fructan 1-exohydrolase w3 (1-FEHw3) genes. Our results indicated clear differences in the pattern of WSC accumulation and the expression of genes regulating fructan metabolism between the tolerant and susceptible genotypes under WS. PMID:28552955

SMAD4 is Involved in the Development of Endotoxin Tolerance in Microglia.

PubMed

Liu, Xiaorong; Qin, Yongwei; Dai, Aihua; Zhang, Yu; Xue, Huaqing; Ni, Haidan; Han, Lijian; Zhu, Liang; Yuan, Debin; Tao, Tao; Cao, Maohong

2016-07-01

Initial exposure of macrophages to LPS induces hyporesponsiveness to a second challenge with LPS, a phenomenon termed LPS tolerance. Smad4 plays important roles in the induction of LPS tolerance. However, the function of Smad4 in microglia remains unknown. Here we show that expression of Smad4 was highly up-regulated in LPS-tolerized mouse cerebral cortex. Smad4 was mostly colocalized with microglia, rarely with neurons. Using a microglia cell line, BV2, we find that LPS activates endogenous Smad4, inducing its migration into the nucleus and increasing its expression. Smad4 significantly suppressed TLR-triggered production of proinflammatory cytokines (IL-6), increased anti-inflammatory cytokine in LPS-tolerized microglia. Moreover, IL-6 concentrations in culture supernatants after second LPS challenge are higher in SMAD4 small interfering RNA (siRNA) BV2 cells than control siRNA BV2 cells, indicating failure to induce tolerance in absence of Smad4 signaling. In our study, we conclude that both in vivo and in vitro, Smad4 signaling is required for maximal induction of endotoxin tolerance.

Cross-induction of detoxification genes by environmental xenobiotics and insecticides in the mosquito Aedes aegypti: impact on larval tolerance to chemical insecticides.

PubMed

Poupardin, Rodolphe; Reynaud, Stéphane; Strode, Clare; Ranson, Hilary; Vontas, John; David, Jean-Philippe

2008-05-01

The effect of exposure of Aedes aegypti larvae to sub-lethal doses of the pyrethroid insecticide permethrin, the organophosphate temephos, the herbicide atrazine, the polycyclic aromatic hydrocarbon fluoranthene and the heavy metal copper on their subsequent tolerance to insecticides, detoxification enzyme activities and expression of detoxification genes was investigated. Bioassays revealed a moderate increase in larval tolerance to permethrin following exposure to fluoranthene and copper while larval tolerance to temephos increased moderately after exposure to atrazine, copper and permethrin. Cytochrome P450 monooxygenases activities were induced in larvae exposed to permethrin, fluoranthene and copper while glutathione S-transferase activities were induced after exposure to fluoranthene and repressed after exposure to copper. Microarray screening of the expression patterns of all detoxification genes following exposure to each xenobiotic with the Aedes Detox Chip identified multiple genes induced by xenobiotics and insecticides. Further expression studies using real-time quantitative PCR confirmed the induction of multiple CYP genes and one carboxylesterase gene by insecticides and xenobiotics. Overall, this study reveals the potential of xenobiotics found in polluted mosquito breeding sites to affect their tolerance to insecticides, possibly through the cross-induction of particular detoxification genes. Molecular mechanisms involved and impact on mosquito control strategies are discussed.

Teacher Preparation in Science, Technology, Engineering, and Mathematics Instruction

ERIC Educational Resources Information Center

DeBiase, Kirstie

2016-01-01

The purpose of this qualitative case study was to gain a better understanding of how induction programs might effectively support STEM K-8 teacher preparation. American schools are not producing competent STEM graduates prepared to meet employment demands. Over the next decade, STEM employment opportunities are expected to increase twice as fast…

Mixed chimerism and split tolerance

PubMed Central

Al-Adra, David P.

2011-01-01

Establishing hematopoietic mixed chimerism can lead to donor-specific tolerance to transplanted organs and may eliminate the need for long-term immunosuppressive therapy, while also preventing chronic rejection. In this review, we discuss central and peripheral mechanisms of chimerism induced tolerance. However, even in the long-lasting presence of a donor organ or donor hematopoietic cells, some allogeneic tissues from the same donor can be rejected; a phenomenon known as split tolerance. With the current goal of creating mixed chimeras using clinically feasible amounts of donor bone marrow and with minimal conditioning, split tolerance may become more prevalent and its mechanisms need to be explored. Some predisposing factors that may increase the likelihood of split tolerance are immunogenicity of the graft, certain donor-recipient combinations, prior sensitization, location and type of graft and minimal conditioning chimerism induction protocols. Additionally, split tolerance may occur due to a differential susceptibility of various types of tissues to rejection. The mechanisms involved in a tissue’s differential susceptibility to rejection include the presence of polymorphic tissue-specific antigens and variable sensitivity to indirect pathway effector mechanisms. Finally, we review the clinical attempts at allograft tolerance through the induction of chimerism; studies that are revealing the complex relationship between chimerism and tolerance. This relationship often displays split tolerance, and further research into its mechanisms is warranted. PMID:22509425

BIOMARKERS OF OPERATIONAL TOLERANCE IN SOLID ORGAN TRANSPLANTATION

PubMed Central

Heidt, Sebastiaan; Wood, Kathryn J.

2012-01-01

Introduction Long-term immunosuppressive therapy represents a huge burden on transplant recipients, but currently cannot be omitted. Improving long-term transplant outcome by immunosuppressive drug withdrawal may be achieved in patients who have developed (partial) immunological unresponsiveness towards their graft, either spontaneously or through tolerance induction. Reliable biomarkers are essential to define such immunological unresponsiveness and will facilitate controlled immunosuppressive drug weaning as well as provide surrogate end-points for tolerance induction trials. Areas covered Tolerance biomarkers have been defined for both liver and kidney transplantation and can accurately identify operationally tolerant transplant recipients retrospectively. These two tolerance fingerprints are remarkably different, indicating the involvement of distinct mechanisms. Limited data suggest that tolerance biomarkers can be detected in immunosuppressed transplant recipients. Whether these patients can safely have their immunosuppressive drugs withdrawn needs to be established. Expert opinion Mechanistic interpretation of the kidney transplant tolerance biomarker profile dominated by B cell markers remains a challenge in light of experimental evidence suggesting the pivotal involvement of regulatory T cells. Therefore, defining animal models that resemble human transplant tolerance is crucial in understanding the underlying mechanisms. Additionally, to ensure patient safety while monitoring for tolerance, it is essential to develop biomarkers to non-invasively detect early signs of rejection as well. PMID:22988481

Differentiation of PDX1 gene-modified human umbilical cord mesenchymal stem cells into insulin-producing cells in vitro.

PubMed

He, Dongmei; Wang, Juan; Gao, Yangjun; Zhang, Yuan

2011-12-01

Mesenchymal stem cells (MSCs) have significant advantages over other stem cell types, and greater potential for immediate clinical application. MSCs would be an interesting cellular source for treatment of type 1 diabetes. In this study, MSCs from human umbilical cord were differentiated into functional insulin-producing cells in vitro by introduction of the pancreatic and duodenal homeobox factor 1 (PDX1) and in the presence of induction factors. The expressions of cell surface antigens were detected by flow cytometry. After induction in an adipogenic medium or an osteogenic medium, the cells were observed by Oil Red O staining and alkaline phosphatase staining. Recombinant adenovirus carrying the PDX1 gene was constructed and MSCs were infected by the recombinant adenovirus, then treated with several inducing factors for differentiation into islet β-like cells. The expression of the genes and protein related to islet β-cells was detected by immunocytochemistry, RT-PCR and Western blot analysis. Insulin and C-peptide secretion were assayed. Our results show that the morphology and immunophenotype of MSCs from human umbilical cord were similar to those present in human bone marrow. The MSCs could be induced to differentiate into osteocytes and adipocytes. After induction by recombined adenovirus vector with induction factors, MSCs were aggregated and presented islet-like bodies. Dithizone staining of these cells was positive. The genes' expression related to islet β-cells was found. After induction, insulin and C-peptide secretion in the supernatant were significantly increased. In conclusion, our results demonstrated that PDX1 gene-modified human umbilical cord mesenchymal stem cells could be differentiated into insulin-producing cells in vitro.

Chondrogenesis of Embryonic Stem Cell-Derived Mesenchymal Stem Cells Induced by TGFβ1 and BMP7 Through Increased TGFβ Receptor Expression and Endogenous TGFβ1 Production.

PubMed

Lee, Patrick T; Li, Wan-Ju

2017-01-01

For decades stem cells have proven to be invaluable to the study of tissue development. More recently, mesenchymal stem cells (MSCs) derived from embryonic stem cells (ESCs) (ESC-MSCs) have emerged as a cell source with great potential for the future of biomedical research due to their enhanced proliferative capability compared to adult tissue-derived MSCs and effectiveness of musculoskeletal lineage-specific cell differentiation compared to ESCs. We have previously compared the properties and differentiation potential of ESC-MSCs to bone marrow-derived MSCs. In this study, we evaluated the potential of TGFβ1 and BMP7 to induce chondrogenic differentiation of ESC-MSCs compared to that of TGFβ1 alone and further investigated the cellular phenotype and intracellular signaling in response to these induction conditions. Our results showed that the expression of cartilage-associated markers in ESC-MSCs induced by the TGFβ1 and BMP7 combination was increased compared to induction with TGFβ1 alone. The TGFβ1 and BMP7 combination upregulated the expression of TGFβ receptor and the production of endogenous TGFβs compared to TGFβ1 induction. The growth factor combination also increasingly activated both of the TGF and BMP signaling pathways, and inhibition of the signaling pathways led to reduced chondrogenesis of ESC-MSCs. Our findings suggest that by adding BMP7 to TGFβ1-supplemented induction medium, ESC-MSC chondrogenesis is upregulated through increased production of endogenous TGFβ and activities of TGFβ and BMP signaling. J. Cell. Biochem. 118: 172-181, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Stem cell senescence drives age-attenuated induction of pituitary tumours in mouse models of paediatric craniopharyngioma.

PubMed

Mario Gonzalez-Meljem, Jose; Haston, Scott; Carreno, Gabriela; Apps, John R; Pozzi, Sara; Stache, Christina; Kaushal, Grace; Virasami, Alex; Panousopoulos, Leonidas; Neda Mousavy-Gharavy, Seyedeh; Guerrero, Ana; Rashid, Mamunur; Jani, Nital; Goding, Colin R; Jacques, Thomas S; Adams, David J; Gil, Jesus; Andoniadou, Cynthia L; Martinez-Barbera, Juan Pedro

2017-11-28

Senescent cells may promote tumour progression through the activation of a senescence-associated secretory phenotype (SASP), whether these cells are capable of initiating tumourigenesis in vivo is not known. Expression of oncogenic β-catenin in Sox2+ young adult pituitary stem cells leads to formation of clusters of stem cells and induction of tumours resembling human adamantinomatous craniopharyngioma (ACP), derived from Sox2- cells in a paracrine manner. Here, we uncover the mechanisms underlying this paracrine tumourigenesis. We show that expression of oncogenic β-catenin in Hesx1+ embryonic precursors also results in stem cell clusters and paracrine tumours. We reveal that human and mouse clusters are analogous and share a common signature of senescence and SASP. Finally, we show that mice with reduced senescence and SASP responses exhibit decreased tumour-inducing potential. Together, we provide evidence that senescence and a stem cell-associated SASP drive cell transformation and tumour initiation in vivo in an age-dependent fashion.

Isolation of adipose derived stem cells and their induction to a chondrogenic phenotype

PubMed Central

Estes, Bradley T.; Diekman, Brian O.; Gimble, Jeffrey M.; Guilak, Farshid

2011-01-01

Summary The ability to isolate, expand, and differentiate adult stem cells into a chondrogenic lineage is an important step in the development of tissue engineering approaches for cartilage repair or regeneration for the treatment of joint injury or osteoarthritis, or for application in plastic or reconstructive surgery. Adipose-derived stem cells (ASCs) provide an abundant and easily accessible source of adult stem cells for use in such regenerative approaches. This protocol describes the isolation of ASCs from liposuction aspirate, as well as cell culture conditions for growth factor based induction of ASCs into chondrocyte-like cells. These methods are similar to those used for bone marrow mesenchymal stem cells but distinct due to the unique properties of ASCs. Investigators can expect consistent ASC differentiation, allowing for slight variation due to donor and serum lot effects. Approximately 10–12 weeks are needed for ASC isolation and the characterization of chondrocyte-like cells, which is also described. PMID:20595958

Maternal alloantibodies induce a postnatal immune response that limits engraftment following in utero hematopoietic cell transplantation in mice

PubMed Central

Merianos, Demetri J.; Tiblad, Eleonor; Santore, Matthew T.; Todorow, Carlyn A.; Laje, Pablo; Endo, Masayuki; Zoltick, Philip W.; Flake, Alan W.

2009-01-01

The lack of fetal immune responses to foreign antigens, i.e., fetal immunologic tolerance, is the most compelling rationale for prenatal stem cell and gene therapy. However, the frequency of engraftment following in utero hematopoietic cell transplantation (IUHCT) in the murine model is reduced in allogeneic, compared with congenic, recipients. This observation supports the existence of an immune barrier to fetal transplantation and challenges the classic assumptions of fetal tolerance. Here, we present evidence that supports the presence of an adaptive immune response in murine recipients of IUHCT that failed to maintain engraftment. However, when IUHCT recipients were fostered by surrogate mothers, they all maintained long-term chimerism. Furthermore, we have demonstrated that the cells responsible for rejection of the graft were recipient in origin. Our observations suggest a mechanism by which IUHCT-dependent sensitization of the maternal immune system and the subsequent transmission of maternal alloantibodies to pups through breast milk induces a postnatal adaptive immune response in the recipient, which, in turn, results in the ablation of engraftment after IUHCT. Finally, we showed that non-fostered pups that maintained their chimerism had higher levels of Tregs as well as a more suppressive Treg phenotype than their non-chimeric, non-fostered siblings. This study resolves the apparent contradiction of induction of an adaptive immune response in the pre-immune fetus and confirms the potential of actively acquired tolerance to facilitate prenatal therapeutic applications. PMID:19652363

Online induction heating for determination of isotope composition of woody stem water with laser spectrometry: A methods assessment

USGS Publications Warehouse

Lazarus, Brynne E.; Germino, Matthew; Vander Veen, Jessica L.

2016-01-01

Application of stable isotopes of water to studies of plant–soil interactions often requires a substantial preparatory step of extracting water from samples without fractionating isotopes. Online heating is an emerging approach for this need, but is relatively untested and major questions of how to best deliver standards and assess interference by organics have not been evaluated. We examined these issues in our application of measuring woody stem xylem of sagebrush using a Picarro laser spectrometer with online induction heating. We determined (1) effects of cryogenic compared to induction-heating extraction, (2) effects of delivery of standards on filter media compared to on woody stem sections, and (3) spectral interference from organic compounds for these approaches (and developed a technique to do so). Our results suggest that matching sample and standard media improves accuracy, but that isotopic values differ with the extraction method in ways that are not due to spectral interference from organics.

New markers for tracking endoderm induction and hepatocyte differentiation from human pluripotent stem cells

PubMed Central

Holtzinger, Audrey; Streeter, Philip R.; Sarangi, Farida; Hillborn, Scott; Niapour, Maryam; Ogawa, Shinichiro; Keller, Gordon

2015-01-01

The efficient generation of hepatocytes from human pluripotent stem cells (hPSCs) requires the induction of a proper endoderm population, broadly characterized by the expression of the cell surface marker CXCR4. Strategies to identify and isolate endoderm subpopulations predisposed to the liver fate do not exist. In this study, we generated mouse monoclonal antibodies against human embryonic stem cell-derived definitive endoderm with the goal of identifying cell surface markers that can be used to track the development of this germ layer and its specification to a hepatic fate. Through this approach, we identified two endoderm-specific antibodies, HDE1 and HDE2, which stain different stages of endoderm development and distinct derivative cell types. HDE1 marks a definitive endoderm population with high hepatic potential, whereas staining of HDE2 tracks with developing hepatocyte progenitors and hepatocytes. When used in combination, the staining patterns of these antibodies enable one to optimize endoderm induction and hepatic specification from any hPSC line. PMID:26493401

Cardiogenic programming of human pluripotent stem cells by dose-controlled activation of EOMES.

PubMed

Pfeiffer, Martin J; Quaranta, Roberto; Piccini, Ilaria; Fell, Jakob; Rao, Jyoti; Röpke, Albrecht; Seebohm, Guiscard; Greber, Boris

2018-01-30

Master cell fate determinants are thought to induce specific cell lineages in gastrulation by orchestrating entire gene programs. The T-box transcription factor EOMES (eomesodermin) is crucially required for the development of the heart-yet it is equally important for endoderm specification suggesting that it may act in a context-dependent manner. Here, we define an unrecognized interplay between EOMES and the WNT signaling pathway in controlling cardiac induction by using loss and gain-of-function approaches in human embryonic stem cells. Dose-dependent EOMES induction alone can fully replace a cocktail of signaling molecules otherwise essential for the specification of cardiogenic mesoderm. Highly efficient cardiomyocyte programming by EOMES mechanistically involves autocrine activation of canonical WNT signaling via the WNT3 ligand, which necessitates a shutdown of this axis at a subsequent stage. Our findings provide insights into human germ layer induction and bear biotechnological potential for the robust production of cardiomyocytes from engineered stem cells.

Patient quality of life following induction of oral immunotherapy for food allergy.

PubMed

Epstein Rigbi, Na'ama; Katz, Yitzhak; Goldberg, Michael R; Levy, Michael B; Nachshon, Liat; Elizur, Arnon

2016-05-01

Patient quality of life improves following successful completion of oral immunotherapy (OIT), but the process itself might have undesirable effects. We aimed to evaluate patient quality of life following OIT initial induction. The Hebrew version of the Food Allergy Quality of Life Questionnaire-Parental Form (FAQLQ-PF) was validated and administered to the parents of children following the first week of OIT for food allergy (n = 119). Patient demographics and clinical history as well as the course of initial induction week were reviewed. Pre-OIT severity of food allergy, defined as severity of reactions due to accidental exposure to the allergenic food (anaphylactic reactions, p = 0.017; epinephrine use, p = 0.049; emergency room referrals p = 0.003; and hospital admissions, p = 0.015) and a lower number of tolerated doses during initial induction, reflective of a lower maximal tolerated dose for the different allergens (p = 0.011) were associated with worse total FAQLQ-PF scores. The number of tolerated doses during induction and pre-OIT emergency room referrals remained significantly associated with worse total score of the FAQLQ-PF on multivariate analysis (p = 0.016 and p = 0.005, respectively). The correlation between the number of tolerated doses and quality of life scores was moderate-strong primarily in children aged 6-12 years (Total score, r = -0.41, p = 0.001; Emotional Impact r = -0.42, p = 0.001; Food Anxiety, r = -0.38, p = 0.002; Social and Dietary Limitations, r = -0.33, p = 0.009). Pre-OIT reaction severity affects quality of life in both preschool and school-aged food-allergic children. In contrast, a lower maximal tolerated dose during OIT induction is associated with worse indices of quality of life primarily in children aged 6-12 years. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Induction of differentiation of human embryonic stem cells into functional hair-cell-like cells in the absence of stromal cells.

PubMed

Ding, Jie; Tang, Zihua; Chen, Jiarong; Shi, Haosong; Chen, Jianling; Wang, Cuicui; Zhang, Cui; Li, Liang; Chen, Ping; Wang, Jinfu

2016-12-01

Sensorineural hearing loss and vestibular dysfunction have become the most common forms of sensory defects. Stem cell-based therapeutic strategies for curing hearing loss are being developed. Several attempts to develop hair cells by using chicken utricle stromal cells as feeder cells have resulted in phenotypic conversion of stem cells into inner ear hair-cell-like cells. Here, we induced the differentiation of human embryonic stem cells (hESCs) into otic epithelial progenitors (OEPs), and further induced the differentiation of OEPs into hair-cell-like cells using different substrates. Our results showed that OEPs cultured on the chicken utricle stromal cells with the induction medium could differentiate into hair-cell-like cells with stereociliary bundles. Co-culture with stromal cells, however, may be problematic for subsequent examination of the induced hair-cell-like cells. In order to avoid the interference from stromal cells, we cultured OEPs on laminin with different induction media and examined the effects of the induction medium on the differentiation potentials of OEPs into hair-cell-like cells. The results revealed that the culture of OEPs on laminin with the conditioned medium from chicken utricle stromal cells supplemented with EGF and all-trans retinoic acid (RA) could promote the organization of cells into epithelial clusters displaying hair-cell-like cells with stereociliary bundles. These cells also displayed the expected electrophysiological properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

Directed induction of functional motor neuron-like cells from genetically engineered human mesenchymal stem cells.

PubMed

Park, Hwan-Woo; Cho, Jung-Sun; Park, Chul-Kyu; Jung, Sung Jun; Park, Chang-Hwan; Lee, Shin-Jae; Oh, Seog Bae; Park, Young-Seok; Chang, Mi-Sook

2012-01-01

Cell replacement using stem cells is a promising therapeutic approach to treat degenerative motor neuron (MN) disorders, such as amyotrophic lateral sclerosis and spinal cord injury. Human bone marrow-derived mesenchymal stem cells (hMSCs) are a desirable cell source for autologous cell replacement therapy to treat nervous system injury due to their plasticity, low immunogenicity, and a lower risk of tumor formation than embryonic stem cells. However, hMSCs are inefficient with regards to differentiating into MN-like cells. To solve this limitation, we genetically engineered hMSCs to express MN-associated transcription factors, Olig2 and Hb9, and then treat the hMSCs expressing Olig2 and Hb9 with optimal MN induction medium (MNIM). This method of induction led to higher expression (>30% of total cells) of MN markers. Electrophysiological data revealed that the induced hMSCs had the excitable properties of neurons and were able to form functional connections with muscle fibers in vitro. Furthermore, when the induced hMSCs were transplanted into an injured organotypic rat spinal cord slice culture, an ex vivo model of spinal cord injury, they exhibited characteristics of MNs. The data strongly suggest that induced Olig2/Hb9-expressing hMSCs were clearly reprogrammed and directed toward a MN-like lineage. We propose that methods to induce Olig2 and Hb9, followed by further induction with MNIM have therapeutic potential for autologous cell replacement therapy to treat degenerative MN disorders.

Freezing resistance in Patagonian woody shrubs: the role of cell wall elasticity and stem vessel size.

PubMed

Zhang, Yong-Jiang; Bucci, Sandra J; Arias, Nadia S; Scholz, Fabian G; Hao, Guang-You; Cao, Kun-Fang; Goldstein, Guillermo

2016-08-01

Freezing resistance through avoidance or tolerance of extracellular ice nucleation is important for plant survival in habitats with frequent subzero temperatures. However, the role of cell walls in leaf freezing resistance and the coordination between leaf and stem physiological processes under subzero temperatures are not well understood. We studied leaf and stem responses to freezing temperatures, leaf and stem supercooling, leaf bulk elastic modulus and stem xylem vessel size of six Patagonian shrub species from two sites (plateau and low elevation sites) with different elevation and minimum temperatures. Ice seeding was initiated in the stem and quickly spread to leaves, but two species from the plateau site had barriers against rapid spread of ice. Shrubs with xylem vessels smaller in diameter had greater stem supercooling capacity, i.e., ice nucleated at lower subzero temperatures. Only one species with the lowest ice nucleation temperature among all species studied exhibited freezing avoidance by substantial supercooling, while the rest were able to tolerate extracellular freezing from -11.3 to -20 °C. Leaves of species with more rigid cell walls (higher bulk elastic modulus) could survive freezing to lower subzero temperatures, suggesting that rigid cell walls potentially reduce the degree of physical injury to cell membranes during the extracellular freezing and/or thaw processes. In conclusion, our results reveal the temporal-spatial ice spreading pattern (from stem to leaves) in Patagonian shrubs, and indicate the role of xylem vessel size in determining supercooling capacity and the role of cell wall elasticity in determining leaf tolerance of extracellular ice formation. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Fault tolerant vector control of induction motor drive

NASA Astrophysics Data System (ADS)

Odnokopylov, G.; Bragin, A.

2014-10-01

For electric composed of technical objects hazardous industries, such as nuclear, military, chemical, etc. an urgent task is to increase their resiliency and survivability. The construction principle of vector control system fault-tolerant asynchronous electric. Displaying recovery efficiency three-phase induction motor drive in emergency mode using two-phase vector control system. The process of formation of a simulation model of the asynchronous electric unbalance in emergency mode. When modeling used coordinate transformation, providing emergency operation electric unbalance work. The results of modeling transient phase loss motor stator. During a power failure phase induction motor cannot save circular rotating field in the air gap of the motor and ensure the restoration of its efficiency at rated torque and speed.

The therapeutic potential of cell identity reprogramming for the treatment of aging-related neurodegenerative disorders

PubMed Central

Smith, Derek K.; He, Miao; Zhang, Chun-Li; Zheng, Jialin C.

2018-01-01

Neural cell identity reprogramming strategies aim to treat age-related neurodegenerative disorders with newly induced neurons that regenerate neural architecture and functional circuits in vivo. The isolation and neural differentiation of pluripotent embryonic stem cells provided the first in vitro models of human neurodegenerative disease. Investigation into the molecular mechanisms underlying stem cell pluripotency revealed that somatic cells could be reprogrammed to induced pluripotent stem cells (iPSCs) and these cells could be used to model Alzheimer disease, amyotrophic lateral sclerosis, Huntington disease, and Parkinson disease. Additional neural precursor and direct transdifferentiation strategies further enabled the induction of diverse neural linages and neuron subtypes both in vitro and in vivo. In this review, we highlight neural induction strategies that utilize stem cells, iPSCs, and lineage reprogramming to model or treat age-related neurodegenerative diseases, as well as, the clinical challenges related to neural transplantation and in vivo reprogramming strategies. PMID:26844759

TUNING IMMUNE TOLERANCE WITH VASOACTIVE INTESTINAL PEPTIDE: A NEW THERAPEUTIC APPROACH FOR IMMUNE DISORDERS

PubMed Central

POZO, DAVID; GONZALEZ-REY, ELENA; CHORNY, ALEJO; ANDERSON, PER; VARELA, NIEVES; DELGADO, MARIO

2007-01-01

The induction of immune tolerance is essential for the maintenance of immune homeostasis and to limit the occurrence of exacerbated inflammatory and autoimmune conditions. Multiple mechanisms act together to ensure self-tolerance, including central clonal deletion, cytokine deviation and induction of regulatory T cells. Identifying the factors that regulate these processes is crucial for the development of new therapies of autoimmune diseases and transplantation. The vasoactive intestinal peptide (VIP) is a well-characterized endogenous anti-inflammatory neuropeptide with therapeutic potential for a variety of immune disorders. Here we examine the latest research findings, which indicate that VIP participates in maintaining immune tolerance in two distinct ways: by regulating the balance between pro-inflammatory and anti-inflammatory factors, and by inducing the emergence of regulatory T cells with suppressive activity against autoreactive T-cell effectors. PMID:17521775

Metronomic chemotherapy prevents therapy-induced stromal activation and induction of tumor-initiating cells

PubMed Central

Chan, Tze-Sian; Pai, Vincent C.; Tan, Kok-Tong; Yen, Chia-Jui; Hsu, Shu-Ching; Chen, Wei-Yu; Shan, Yan-Shen; Lee, Michael T.; Chu, Jui-Mei

2016-01-01

Although traditional chemotherapy kills a fraction of tumor cells, it also activates the stroma and can promote the growth and survival of residual cancer cells to foster tumor recurrence and metastasis. Accordingly, overcoming the host response induced by chemotherapy could substantially improve therapeutic outcome and patient survival. In this study, resistance to treatment and metastasis has been attributed to expansion of stem-like tumor-initiating cells (TICs). Molecular analysis of the tumor stroma in neoadjuvant chemotherapy–treated human desmoplastic cancers and orthotopic tumor xenografts revealed that traditional maximum-tolerated dose chemotherapy, regardless of the agents used, induces persistent STAT-1 and NF-κB activity in carcinoma-associated fibroblasts. This induction results in the expression and secretion of ELR motif–positive (ELR+) chemokines, which signal through CXCR-2 on carcinoma cells to trigger their phenotypic conversion into TICs and promote their invasive behaviors, leading to paradoxical tumor aggression after therapy. In contrast, the same overall dose administered as a low-dose metronomic chemotherapy regimen largely prevented therapy-induced stromal ELR+ chemokine paracrine signaling, thus enhancing treatment response and extending survival of mice carrying desmoplastic cancers. These experiments illustrate the importance of stroma in cancer therapy and how its impact on treatment resistance could be tempered by altering the dosing schedule of systemic chemotherapy. PMID:27881732

Whole-brain radiotherapy or autologous stem-cell transplantation as consolidation strategies after high-dose methotrexate-based chemoimmunotherapy in patients with primary CNS lymphoma: results of the second randomisation of the International Extranodal Lymphoma Study Group-32 phase 2 trial.

PubMed

Ferreri, Andrés J M; Cwynarski, Kate; Pulczynski, Elisa; Fox, Christopher P; Schorb, Elisabeth; La Rosée, Paul; Binder, Mascha; Fabbri, Alberto; Torri, Valter; Minacapelli, Eleonora; Falautano, Monica; Ilariucci, Fiorella; Ambrosetti, Achille; Roth, Alexander; Hemmaway, Claire; Johnson, Peter; Linton, Kim M; Pukrop, Tobias; Sønderskov Gørløv, Jette; Balzarotti, Monica; Hess, Georg; Keller, Ulrich; Stilgenbauer, Stephan; Panse, Jens; Tucci, Alessandra; Orsucci, Lorella; Pisani, Francesco; Levis, Alessandro; Krause, Stefan W; Schmoll, Hans J; Hertenstein, Bernd; Rummel, Mathias; Smith, Jeffery; Pfreundschuh, Michael; Cabras, Giuseppina; Angrilli, Francesco; Ponzoni, Maurilio; Deckert, Martina; Politi, Letterio S; Finke, Jürgen; Reni, Michele; Cavalli, Franco; Zucca, Emanuele; Illerhaus, Gerald

2017-11-01

The International Extranodal Lymphoma Study Group-32 (IELSG32) trial is an international randomised phase 2 study that addresses two key clinical questions in the treatment of patients with newly diagnosed primary CNS lymphoma. Results of the first randomisation have demonstrated that methotrexate, cytarabine, thiotepa, and rituximab (called the MATRix regimen) is the induction combination associated with significantly better outcome compared with the other induction combinations tested. Here, we report the results of the second randomisation that addresses the efficacy of myeloablative chemotherapy supported by autologous stem-cell transplantation (ASCT), as an alternative to whole-brain radiotherapy (WBRT), as consolidation after high-dose-methotrexate-based chemoimmunotherapy. HIV-negative patients (aged 18-70 years) with newly diagnosed primary CNS lymphoma and an Eastern Cooperative Oncology Group performance status of 0-3 were randomly assigned to receive four courses of methotrexate 3·5 g/m 2 on day 1 plus cytarabine 2 g/m 2 twice daily on days 2 and 3 (group A); or the same combination plus two doses of rituximab 375 mg/m 2 on days -5 and 0 (group B); or the same methotrexate-cytarabine-rituximab combination plus thiotepa 30 mg/m 2 on day 4 (group C), with the three groups repeating treatment every 3 weeks. Patients with responsive or stable disease after induction treatment, with adequate autologous peripheral blood stem-cell collection, and without persistent iatrogenic side-effects, were eligible for the second randomisation between WBRT (photons of 4-10 MeV; five fractions per week; fraction size 180 cGy; started within 4 weeks from the last induction course; group D) and carmustine-thiotepa conditioned ASCT (carmustine 400 mg/m 2 on day -6, and thiotepa 5 mg/kg every 12 h on days -5 and -4, followed by reinfusion of autologous peripheral blood stem cells; group E). A permuted block randomised design was adopted for both randomisations, and a computer-generated randomisation list was used within each stratum. No masking after assignment to intervention was adopted. The primary endpoint was 2-year progression-free survival, with induction group and response to induction chemotherapy as stratification parameters. Analyses were done on a modified intention-to-treat basis. This study is registered with ClinicalTrials.gov, number NCT01011920. Between Feb 19, 2010, and Aug 27, 2014, 227 patients were recruited from 53 centres in five countries. 219 of 227 enrolled patients were assessable. Of the 122 patients eligible for the second randomisation, 118 patients were randomly assigned to WBRT or ASCT (59 patients per group) and constitute the study population. WBRT and ASCT were both effective, and achieved the predetermined efficacy threshold of at least 40 progression-free survivors at 2 years among the first 52 patients in both groups D and E. There were no significant differences in 2-year progression-free survival between WBRT and ASCT: 80% (95% CI 70-90) in group D and 69% (59-79) in group E (hazard ratio 1·50, 95% CI 0·83-2·71; p=0·17). Both consolidation therapies were well tolerated. Grade 4 non-haematological toxicity was uncommon; as expected, haematological toxicity was more common in patients treated with ASCT than in those who received WBRT. Two toxic deaths (infections) were recorded, both in patients who received ASCT. WBRT and ASCT are both feasible and effective as consolidation therapies after high-dose methotrexate-based chemoimmunotherapy in patients aged 70 years or younger with primary CNS lymphoma. The risks and implications of cognitive impairment after WBRT should be considered at the time of therapeutic decision. Agenzia Italiana del Farmaco, Cancer Research UK, Oncosuisse, and Swiss National Science Foundation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Treating relapsed or refractory Philadelphia chromosome-negative acute lymphoblastic leukemia: liposome-encapsulated vincristine

PubMed Central

Davis, Tyler; Farag, Sherif S

2013-01-01

Acute lymphoblastic leukemia (ALL) remains a disease with poor outcomes in adults. While induction chemotherapy achieves a complete remission in almost 90% of patients, the majority will relapse and die of their disease. Relapsed ALL is associated with a high reinduction mortality and chemotherapy resistance, with allogeneic hematopoietic stem cell transplantation offering the only therapy with curative potential. However, there is no efficacious and well tolerated standard regimen accepted as a “bridge” to allogeneic stem cell transplantation or as definitive treatment for patients who are not transplant candidates. Vincristine is an active drug in patients with ALL, but its dose intensity is limited by neurotoxicity, and its full potential as an anticancer drug is thus not realized. Encapsulation of vincristine into sphingomyelin and cholesterol nanoparticle liposomes facilitates dose-intensification and densification to enhanced target tissues with reduced potential for toxicity. Vincristine sulfate liposome injection (VSLI) is associated with significant responses in clinically advanced ALL, and has recently been approved by the US Food and Drug Administration for treatment of relapsed and clinically advanced Philadelphia chromosome-negative ALL. This review provides an overview of the preclinical and clinical studies leading to the approval of VSLI for the treatment of relapsed and refractory ALL, and suggests potential areas of future clinical development. PMID:24072970

Regulatory mechanism of protein metabolic pathway during the differentiation process of chicken male germ cell.

PubMed

Li, Dong; Zuo, Qisheng; Lian, Chao; Zhang, Lei; Shi, Qingqing; Zhang, Zhentao; Wang, Yingjie; Ahmed, Mahmoud F; Tang, Beibei; Xiao, Tianrong; Zhang, Yani; Li, Bichun

2015-08-01

We explored the regulatory mechanism of protein metabolism during the differentiation process of chicken male germ cells and provide a basis for improving the induction system of embryonic stem cell differentiation to male germ cells in vitro. We sequenced the transcriptome of embryonic stem cells, primordial germ cells, and spermatogonial stem cells with RNA sequencing (RNA-Seq), bioinformatics analysis methods, and detection of the key genes by quantitative reverse transcription PCR (qRT-PCR). Finally, we found 16 amino acid metabolic pathways enriched in the biological metabolism during the differentiation process of embryonic stem cells to primordial germ cells and 15 amino acid metabolic pathways enriched in the differentiation stage of primordial germ cells to spermatogonial stem cells. We found three pathways, arginine-proline metabolic pathway, tyrosine metabolic pathway, and tryptophan metabolic pathway, significantly enriched in the whole differentiation process of embryonic stem cells to spermatogonial stem cells. Moreover, for these three pathways, we screened key genes such as NOS2, ADC, FAH, and IDO. qRT-PCR results showed that the expression trend of these genes were the same to RNA-Seq. Our findings showed that the three pathways and these key genes play an important role in the differentiation process of embryonic stem cells to male germ cells. These results provide basic information for improving the induction system of embryonic stem cell differentiation to male germ cells in vitro.

The correlations and sequence of plant stomatal, hydraulic, and wilting responses to drought

PubMed Central

Bartlett, Megan K.; Klein, Tamir; Jansen, Steven; Choat, Brendan; Sack, Lawren

2016-01-01

Climate change is expected to exacerbate drought for many plants, making drought tolerance a key driver of species and ecosystem responses. Plant drought tolerance is determined by multiple traits, but the relationships among traits, either within individual plants or across species, have not been evaluated for general patterns across plant diversity. We synthesized the published data for stomatal closure, wilting, declines in hydraulic conductivity in the leaves, stems, and roots, and plant mortality for 262 woody angiosperm and 48 gymnosperm species. We evaluated the correlations among the drought tolerance traits across species, and the general sequence of water potential thresholds for these traits within individual plants. The trait correlations across species provide a framework for predicting plant responses to a wide range of water stress from one or two sampled traits, increasing the ability to rapidly characterize drought tolerance across diverse species. Analyzing these correlations also identified correlations among the leaf and stem hydraulic traits and the wilting point, or turgor loss point, beyond those expected from shared ancestry or independent associations with water stress alone. Further, on average, the angiosperm species generally exhibited a sequence of drought tolerance traits that is expected to limit severe tissue damage during drought, such as wilting and substantial stem embolism. This synthesis of the relationships among the drought tolerance traits provides crucial, empirically supported insight into representing variation in multiple traits in models of plant and ecosystem responses to drought. PMID:27807136

The correlations and sequence of plant stomatal, hydraulic, and wilting responses to drought.

PubMed

Bartlett, Megan K; Klein, Tamir; Jansen, Steven; Choat, Brendan; Sack, Lawren

2016-11-15

Climate change is expected to exacerbate drought for many plants, making drought tolerance a key driver of species and ecosystem responses. Plant drought tolerance is determined by multiple traits, but the relationships among traits, either within individual plants or across species, have not been evaluated for general patterns across plant diversity. We synthesized the published data for stomatal closure, wilting, declines in hydraulic conductivity in the leaves, stems, and roots, and plant mortality for 262 woody angiosperm and 48 gymnosperm species. We evaluated the correlations among the drought tolerance traits across species, and the general sequence of water potential thresholds for these traits within individual plants. The trait correlations across species provide a framework for predicting plant responses to a wide range of water stress from one or two sampled traits, increasing the ability to rapidly characterize drought tolerance across diverse species. Analyzing these correlations also identified correlations among the leaf and stem hydraulic traits and the wilting point, or turgor loss point, beyond those expected from shared ancestry or independent associations with water stress alone. Further, on average, the angiosperm species generally exhibited a sequence of drought tolerance traits that is expected to limit severe tissue damage during drought, such as wilting and substantial stem embolism. This synthesis of the relationships among the drought tolerance traits provides crucial, empirically supported insight into representing variation in multiple traits in models of plant and ecosystem responses to drought.

Kidney Versus Islet Allograft Survival After Induction of Mixed Chimerism With Combined Donor Bone Marrow Transplantation.

PubMed

Oura, Tetsu; Ko, Dicken S C; Boskovic, Svjetlan; O'Neil, John J; Chipashvili, Vaja; Koulmanda, Maria; Hotta, Kiyohiko; Kawai, Kento; Nadazdin, Ognjenka; Smith, R Neal; Cosimi, A B; Kawai, Tatsuo

2016-01-01

We have previously reported successful induction of transient mixed chimerism and long-term acceptance of renal allografts in MHC mismatched nonhuman primates. In this study, we attempted to extend this tolerance induction approach to islet allografts. A total of eight recipients underwent MHC mismatched combined islet and bone marrow (BM) transplantation after induction of diabetes by streptozotocin. Three recipients were treated after a nonmyeloablative conditioning regimen that included low-dose total body and thymic irradiation, horse Atgam (ATG), six doses of anti-CD154 monoclonal antibody (mAb), and a 1-month course of cyclosporine (CyA) (Islet A). In Islet B, anti-CD8 mAb was administered in place of CyA. In Islet C, two recipients were treated with Islet B, but without ATG. The results were compared with previously reported results of eight cynomolgus monkeys that received combined kidney and BM transplantation (Kidney A) following the same conditioning regimen used in Islet A. The majority of kidney/BM recipients achieved long-term renal allograft survival after induction of transient chimerism. However, prolonged islet survival was not achieved in similarly conditioned islet/BM recipients (Islet A), despite induction of comparable levels of chimerism. In order to rule out islet allograft loss due to CyA toxicity, three recipients were treated with anti-CD8 mAb in place of CyA. Although these recipients developed significantly superior mixed chimerism and more prolonged islet allograft survival (61, 103, and 113 days), islet function was lost soon after the disappearance of chimerism. In Islet C recipients, neither prolonged chimerism nor islet survival was observed (30 and 40 days). Significant improvement of mixed chimerism induction and islet allograft survival were achieved with a CyA-free regimen that included anti-CD8 mAb. However, unlike the kidney allograft, islet allograft tolerance was not induced with transient chimerism. Induction of more durable mixed chimerism may be necessary for induction of islet allograft tolerance.

Induction of tolerance towards TNP entails down-regulation of an autoimmune attack.

PubMed Central

Zöller, M; Andrighetto, G

1988-01-01

In order to follow the process of induction and maintainance of tolerance, BALB/c mice were tolerized by free hapten, and effector and regulatory cell interactions were analysed by limiting-dilution (LD) cultures. Injection of trinitrobenzenesulphonic acid (TNBS) resulted, predominantly, in the activation and expansion of self-reactive cytotoxic T cells (CTL), which were observed transiently at frequencies comparable to allo-specific CTL. In addition, self-reactive helper T cells (Th) were activated and expanded in tolerized mice. TNP-specific reactivity was difficult to evaluate, since cytotoxic activity against haptenized self followed the pattern of self-reactivity throughout the test period. But in LD cultures determining proliferation, two populations of Th responding to TNP-self were observed, while only one Th population could be detected in response to self. Expansion/activation of Th and CTL precursors (CTLp) was followed by activation of suppressor T cells (Ts). The suppressor population could be divided into two subpopulations, one interfering with Th, the second interacting directly with CTL (veto cells). The results indicate that during the induction of tolerance, animals pass through an autoimmune attack, with expansion and activation of self-reactive clones (CTL, Th). The final status of non-responsiveness towards TNP is not due to the deletion of effector or regulatory cells, but results from the establishment of a steady state of dominance of self-reactive and TNP-self-reactive suppression. PMID:2965095

Indoleamine 2,3-dioxygenase-dependent tryptophan metabolites contribute to tolerance induction during allergen immunotherapy in a mouse model.

PubMed

Taher, Yousef A; Piavaux, Benoit J A; Gras, Reneé; van Esch, Betty C A M; Hofman, Gerard A; Bloksma, Nanne; Henricks, Paul A J; van Oosterhout, Antoon J M

2008-04-01

The tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase (IDO) has been implicated in immune suppression and tolerance induction. We examined (1) whether IDO activity is required during tolerance induction by allergen immunotherapy or for the subsequent suppressive effects on asthma manifestations and (2) whether tryptophan depletion or generation of its downstream metabolites is involved. Ovalbumin (OVA)-sensitized and OVA-challenged BALB/c mice that display increased airway responsiveness to methacholine, serum OVA-specific IgE levels, bronchoalveolar eosinophilia, and TH2 cytokine levels were used as a model of allergic asthma. Sensitized mice received subcutaneous optimal (1 mg) or suboptimal (100 microg) OVA immunotherapy. Inhibition of IDO by 1-methyl-DL-tryptophan during immunotherapy, but not during inhalation challenge, partially reversed the suppressive effects of immunotherapy on airway eosinophilia and TH2 cytokine levels, whereas airway hyperresponsiveness and serum OVA-specific IgE levels remained suppressed. Administration of tryptophan during immunotherapy failed to abrogate its beneficial effects toward allergic airway inflammation. Interestingly, administration of tryptophan or its metabolites, kynurenine, 3-hydroxykynurenine, and xanthurenic acid, but not 3-hydroxyanthranilinic acid, quinolinic acid, and kynurenic acid, during suboptimal immunotherapy potentiated the reduction of eosinophilia. These effects coincided with reduced TH2 cytokine levels in bronchoalveolar lavage fluid, but no effects on IgE levels were detected. During immunotherapy, the tryptophan metabolites kynurenine, 3-hydroxykynurenine, and xanthurenic acid generated through IDO contribute to tolerance induction regarding TH2-dependent allergic airway inflammation.

Differentiation and Behavior of Dental Pulp Stem Cells in Hydrogel Scaffolds of Various Stiffnesses

NASA Astrophysics Data System (ADS)

Bhatnagar, Divya; Jurukovski, Vladimir; Rafailovich, Miriam; Simon, Marcia

2011-03-01

Dental Pulp Stem Cells (DPSCs) are known to differentiate in bone, dentine, or nerve tissue through different environment signals. This work investigates whether differentiation could occur in the absence of chemical induction and through mechanical stimuli only. For this study, we chose enzymatically cross-linked gelatin hydrogels as our substrates. Rheological studies carried out by oscillatory shear rheometry indicated that the modulus of the hardest hydrogel was of the order of 8kPa where as the medium and the softest hydrogel had modulus of the order of 1kPa and 100Pa respectively. DPSC were then plated on all three substrates and cultured with and without dexamethasone induction media. After 21 days of incubation, SEM analysis indicated that the cells cultured in the induction media produced biomineralized deposits on hard, medium as well as soft hydrogels. On the other hand, the cells cultured without the induction media also produced large amounts of biomineralized deposits.The modulus of the cells was also measured using AFM. En mass cell migration was also studied to determine the average velocity of migration of DPSCs. We also investigated whether stem cells that are induced to differentiate by their scaffold environment would continue to differentiate and biomineralize when removed from the inducing scaffold.

The Chondrogenic Induction Potential for Bone Marrow-Derived Stem Cells between Autologous Platelet-Rich Plasma and Common Chondrogenic Induction Agents: A Preliminary Comparative Study.

PubMed

Wang, Shan-Zheng; Chang, Qing; Kong, Xiang-Fei; Wang, Chen

2015-01-01

The interests in platelet-rich plasma (PRP) and their application in stem cell therapy have contributed to a better understanding of the basic biology of the prochondrogenesis effect on bone marrow-derived stem cells (BMSCs). We aimed at comparing the effect of autologous PRP with common chondrogenic induction agents (CCIAs) on the chondrogenic differentiation of BMSCs. Rabbit BMSCs were isolated and characterized by flow cytometry and differentiated towards adipocytes and osteoblasts. The chondrogenic response of BMSCs to autologous PRP and CCIAs which included transforming growth factor-β1 (TGF-β1), dexamethasone (DEX), and vitamin C (Vc) was examined by cell pellet culture. The isolated BMSCs after two passages highly expressed CD29 and CD44 but minimally expressed CD45. The osteogenic and adipogenic differentiation potentials of the isolated BMSCs were also confirmed. Compared with common CCIAs, autologous PRP significantly upregulated the chondrogenic related gene expression, including Col-2, AGC, and Sox-9. Osteogenic related gene expression, including Col-1 and OCN, was not of statistical significance between these two groups. Thus, our data shows that, compared with common chondrogenic induction agents, autologous PRP can be more effective in promoting the chondrogenesis of BMSCs.

Hanging drop culture enhances differentiation of human adipose-derived stem cells into anterior neuroectodermal cells using small molecules.

PubMed

Amirpour, Noushin; Razavi, Shahnaz; Esfandiari, Ebrahim; Hashemibeni, Batoul; Kazemi, Mohammad; Salehi, Hossein

2017-06-01

Inspired by in vivo developmental process, several studies were conducted to design a protocol for differentiating of mesenchymal stem cells into neural cells in vitro. Human adipose-derived stem cells (hADSCs) as mesenchymal stem cells are a promising source for this purpose. At current study, we applied a defined neural induction medium by using small molecules for direct differentiation of hADSCs into anterior neuroectodermal cells. Anterior neuroectodermal differentiation of hADSCs was performed by hanging drop and monolayer protocols. At these methods, three small molecules were used to suppress the BMP, Nodal, and Wnt signaling pathways in order to obtain anterior neuroectodermal (eye field) cells from hADSCs. After two and three weeks of induction, the differentiated cells with neural morphology expressed anterior neuroectodermal markers such as OTX2, SIX3, β-TUB III and PAX6. The protein expression of such markers was confirmed by real time, RT-PCR and immunocytochemistry methods According to our data, it seems that the hanging drop method is a proper approach for neuroectodermal induction of hADSCs. Considering wide availability and immunosuppressive properties of hADSCs, these cells may open a way for autologous cell therapy of neurodegenerative disorders. Copyright © 2017 ISDN. Published by Elsevier Ltd. All rights reserved.

Successful treatment of post-transplant relapsed acute myeloid leukemia with FLT3 internal tandem duplication using the combination of induction chemotherapy, donor lymphocyte infusion, sorafenib and azacitidine. Report of three cases

PubMed Central

Campregher, Paulo Vidal; de Mattos, Vinicius Renan Pinto; Salvino, Marco Aurélio; Santos, Fabio Pires de Souza; Hamerschlak, Nelson

2017-01-01

ABSTRACT Acute myeloid leukemia is a hematopoietic stem cell neoplastic disease associated with high morbidity and mortality. The presence of FLT3 internal tandem duplication mutations leads to high rates of relapse and decreased overall survival. Patients with FLT3 internal tandem duplication are normally treated with hematopoietic stem cell transplantation in first complete remission. Nevertheless, the incidence of post-transplant relapse is considerable in this group of patients, and the management of this clinical condition is challenging. The report describes the outcomes of patients with FLT3 internal tandem duplication positive acute myeloid leukemia who relapsed after allogeneic hematopoietic stem cell transplantation and were treated with the combination of re-induction chemotherapy, donor lymphocyte infusion, sorafenib and azacitidine. Three cases are described and all patients achieved prolonged complete remission with the combined therapy. The combination of induction chemotherapy followed by donor lymphocyte infusion, and the maintenance with azacitidine and sorafenib can be effective approaches in the treatment of post-hematopoietic stem cell transplant and relapsed FLT3 internal tandem duplication positive acute myeloid leukemia patients. This strategy should be further explored in the context of clinical trials. PMID:28746590

Some Ethical Concerns About Human Induced Pluripotent Stem Cells.

PubMed

Zheng, Yue Liang

2016-10-01

Human induced pluripotent stem cells can be obtained from somatic cells, and their derivation does not require destruction of embryos, thus avoiding ethical problems arising from the destruction of human embryos. This type of stem cell may provide an important tool for stem cell therapy, but it also results in some ethical concerns. It is likely that abnormal reprogramming occurs in the induction of human induced pluripotent stem cells, and that the stem cells generate tumors in the process of stem cell therapy. Human induced pluripotent stem cells should not be used to clone human beings, to produce human germ cells, nor to make human embryos. Informed consent should be obtained from patients in stem cell therapy.

40 CFR 180.641 - Spirotetramat; tolerances for residues.

Code of Federal Regulations, 2013 CFR

2013-07-01

... growing, except strawberry, subgroup 13-07H 0.30 Black sapote 0.60 Brassica, head and stem, subgroup 5A 2... strawberry. (2) Tolerances are also established for residues of the insecticide spirotetramat, including its...

The Immunogenicity and Immune Tolerance of Pluripotent Stem Cell Derivatives

PubMed Central

Liu, Xin; Li, Wenjuan; Fu, Xuemei; Xu, Yang

2017-01-01

Human embryonic stem cells (hESCs) can undergo unlimited self-renewal and differentiate into all cell types in human body, and therefore hold great potential for cell therapy of currently incurable diseases including neural degenerative diseases, heart failure, and macular degeneration. This potential is further underscored by the promising safety and efficacy data from the ongoing clinical trials of hESC-based therapy of macular degeneration. However, one main challenge for the clinical application of hESC-based therapy is the allogeneic immune rejection of hESC-derived cells by the recipient. The breakthrough of the technology to generate autologous-induced pluripotent stem cells (iPSCs) by nuclear reprogramming of patient’s somatic cells raised the possibility that autologous iPSC-derived cells can be transplanted into the patients without the concern of immune rejection. However, accumulating data indicate that certain iPSC-derived cells can be immunogenic. In addition, the genomic instability associated with iPSCs raises additional safety concern to use iPSC-derived cells in human cell therapy. In this review, we will discuss the mechanism underlying the immunogenicity of the pluripotent stem cells and recent progress in developing immune tolerance strategies of human pluripotent stem cell (hPSC)-derived allografts. The successful development of safe and effective immune tolerance strategy will greatly facilitate the clinical development of hPSC-based cell therapy. PMID:28626459

[Tolerance in transplantation: potential contribution of haematopoietic transplantation and cell therapy].

PubMed

Kleinclauss, François; Bittard, Hugues; Perruche, Sylvain; de Carvalho-Bittencourt, Marcello; Chalopin, Jean-Marc; Hervé, Patrick; Tiberghien, Pierre; Saas, Philippe

2003-12-01

The ultimate objective of organ transplantation is to obtain a state of tolerance, i.e. long-term acceptance of the graft without immunosuppressive therapy in order to limit the complications of these treatments (viral infections, tumours, etc.). The various immunological mechanisms allowing a state of tolerance will be described in this review. Among these various experimental strategies, combined bone marrow (or haematopoietic stem cell) transplantation and organ transplantation, made possible by the development of non-myeloablative or less intensive conditioning, appears to be one of the most promising lines of research. This approach leads to colonization of the recipient by donor cells. This state is described as "macro-chimerism" and achieves a real state of central tolerance in relation to an organ derived from the bone marrow donor. We have shown recently that intravenous injection of apoptotic cells in combination with allogeneic bone marrow cells increases the success rate of bone marrow transplantation. In a model of combined bone marrow/solid organ transplantation, these apoptotic cells induce tolerance limited to the donor's bone marrow cell antigens without inducing auto-immunization. We therefore propose a new approach to cell-based therapy (using the immunomodulating properties of apoptotic cells) to promote the success of haematopoietic stem cell transplantation. This approach can be particularly useful in combined haematopoietic stem cell and organ transplantation in order to induce a state of macro-chimerism.

Salinomycin overcomes ABC transporter-mediated multidrug and apoptosis resistance in human leukemia stem cell-like KG-1a cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fuchs, Dominik; Institute of Immunology, University of Heidelberg, Im Neuenheimer Feld 305, D-69120 Heidelberg; Daniel, Volker

2010-04-16

Leukemia stem cells are known to exhibit multidrug resistance by expression of ATP-binding cassette (ABC) transporters which constitute transmembrane proteins capable of exporting a wide variety of chemotherapeutic drugs from the cytosol. We show here that human promyeloblastic leukemia KG-1a cells exposed to the histone deacetylase inhibitor phenylbutyrate resemble many characteristics of leukemia stem cells, including expression of functional ABC transporters such as P-glycoprotein, BCRP and MRP8. Consequently, KG-1a cells display resistance to the induction of apoptosis by various chemotherapeutic drugs. Resistance to apoptosis induction by chemotherapeutic drugs can be reversed by cyclosporine A, which effectively inhibits the activity ofmore » P-glycoprotein and BCRP, thus demonstrating ABC transporter-mediated drug resistance in KG-1a cells. However, KG-1a are highly sensitive to apoptosis induction by salinomycin, a polyether ionophore antibiotic that has recently been shown to kill human breast cancer stem cell-like cells and to induce apoptosis in human cancer cells displaying multiple mechanisms of drug and apoptosis resistance. Whereas KG-1a cells can be adapted to proliferate in the presence of apoptosis-inducing concentrations of bortezomib and doxorubicin, salinomycin does not permit long-term adaptation of the cells to apoptosis-inducing concentrations. Thus, salinomycin should be regarded as a novel and effective agent for the elimination of leukemia stem cells and other tumor cells exhibiting ABC transporter-mediated multidrug resistance.« less

T-cell receptor revision: friend or foe?

PubMed

Hale, J Scott; Fink, Pamela J

2010-04-01

T-cell receptor (TCR) revision is a process of tolerance induction by which peripheral T cells lose surface expression of an autoreactive TCR, reinduce expression of the recombinase machinery, rearrange genes encoding extrathymically generated TCRs for antigen, and express these new receptors on the cell surface. We discuss the evidence for this controversial tolerance mechanism below. Despite the apparent heresy of post-thymic gene rearrangement, we argue here that TCR revision follows the rules obeyed by maturing thymocytes undergoing gene recombination. Expression of the recombinase is carefully controlled both spatially and temporally, and may be initiated by loss of signals through surface TCRs. The resulting TCR repertoire is characterized by its diversity, self major histocompatibility complex restriction, self tolerance, and ability to mount productive immune responses specific for foreign antigens. Hence, TCR revision is a carefully regulated process of tolerance induction that can contribute to the protection of the individual against invading pathogens while preserving the integrity of self tissue.

Nanotechnology versus stem cell engineering: in vitro comparison of neurite inductive potentials.

PubMed

Morano, Michela; Wrobel, Sandra; Fregnan, Federica; Ziv-Polat, Ofra; Shahar, Abraham; Ratzka, Andreas; Grothe, Claudia; Geuna, Stefano; Haastert-Talini, Kirsten

2014-01-01

Innovative nerve conduits for peripheral nerve reconstruction are needed in order to specifically support peripheral nerve regeneration (PNR) whenever nerve autotransplantation is not an option. Specific support of PNR could be achieved by neurotrophic factor delivery within the nerve conduits via nanotechnology or stem cell engineering and transplantation. Here, we comparatively investigated the bioactivity of selected neurotrophic factors conjugated to iron oxide nanoparticles (np-NTFs) and of bone marrow-derived stem cells genetically engineered to overexpress those neurotrophic factors (NTF-BMSCs). The neurite outgrowth inductive activity was monitored in culture systems of adult and neonatal rat sensory dorsal root ganglion neurons as well as in the cell line from rat pheochromocytoma (PC-12) cell sympathetic culture model system. We demonstrate that np-NTFs reliably support numeric neurite outgrowth in all utilized culture models. In some aspects, especially with regard to their long-term bioactivity, np-NTFs are even superior to free NTFs. Engineered NTF-BMSCs proved to be less effective in induction of sensory neurite outgrowth but demonstrated an increased bioactivity in the PC-12 cell culture system. In contrast, primary nontransfected BMSCs were as effective as np-NTFs in sensory neurite induction and demonstrated an impairment of neuronal differentiation in the PC-12 cell system. Our results evidence that nanotechnology as used in our setup is superior over stem cell engineering when it comes to in vitro models for PNR. Furthermore, np-NTFs can easily be suspended in regenerative hydrogel matrix and could be delivered that way to nerve conduits for future in vivo studies and medical application.

The clinical course of anesthetic induction in lung transplant recipients with pulmonary complications after hematopoietic stem cell transplantation.

PubMed

Mizota, Toshiyuki; Matsukawa, Shino; Fukagawa, Hiroshi; Daijo, Hiroki; Tanaka, Tomoharu; Chen, Fengshi; Date, Hiroshi; Fukuda, Kazuhiko

2015-08-01

We examined the clinical course of anesthetic induction in lung transplant recipients with pulmonary complications after hematopoietic stem cell transplantation (post-HSCT), focusing on ventilatory management. We aimed to determine the incidence of oxygen desaturation during anesthetic induction and severe respiratory acidosis after anesthetic induction in post-HSCT lung transplant recipients, and to explore factors associated with their development. Nineteen consecutive patients who underwent lung transplantation post-HSCT at Kyoto University Hospital (Japan) were retrospectively studied. Data regarding patient characteristics, preoperative examination, and clinical course during anesthetic induction were analyzed. The incidence of oxygen desaturation (SpO2 < 90 %) during anesthetic induction and severe respiratory acidosis (pH < 7.2) after anesthetic induction were 21.1 and 26.3 %, respectively. Reduced dynamic compliance (Cdyn) during mechanical ventilation was significantly associated with oxygen desaturation during anesthetic induction (p = 0.01), as well as severe respiratory acidosis after anesthetic induction (p = 0.01). The preoperative partial pressure of carbon dioxide in arterial blood (PaCO2; r = -0.743, p = 0.002) and body mass index (BMI; r = 0.61, p = 0.021) significantly correlated with Cdyn, and multivariate analysis revealed that both PaCO2 and BMI were independently associated with Cdyn. Oxygen desaturation during anesthetic induction and severe respiratory acidosis after anesthetic induction frequently occur in post-HSCT lung transplant recipients. Low Cdyn may, at least partially, explain oxygen desaturation during anesthetic induction and severe respiratory acidosis after anesthetic induction. Moreover, preoperative hypercapnia and low BMI were predictive of low Cdyn.

Physicochemical Control of Adult Stem Cell Differentiation: Shedding Light on Potential Molecular Mechanisms

DTIC Science & Technology

2010-01-01

stem - cell -based biomedical and therapeutic applications, including tissue engineering, requires an understanding of the cell-cell and cell-environment interactions. To this end, recent efforts have been focused on the manipulation of adult stem cell differentiation using inductive soluble factors, designing suitable mechanical environments, and applying noninvasive physical forces. Although each of these different approaches has been successfully applied to regulate stem cell differentiation, it would be of great interest and

Spectroscopic signature of mouse embryonic stem cell-derived hepatocytes using synchrotron Fourier transform infrared microspectroscopy

NASA Astrophysics Data System (ADS)

Thumanu, Kanjana; Tanthanuch, Waraporn; Ye, Danna; Sangmalee, Anawat; Lorthongpanich, Chanchao; Parnpai, Rangsun; Heraud, Philip

2011-05-01

Stem cell-based therapy for liver regeneration has been proposed to overcome the persistent shortage in the supply of suitable donor organs. A requirement for this to succeed is to find a rapid method to detect functional hepatocytes, differentiated from embryonic stem cells. We propose Fourier transform infrared (FTIR) microspectroscopy as a versatile method to identify the early and last stages of the differentiation process leading to the formation of hepatocytes. Using synchrotron-FTIR microspectroscopy, the means of identifying hepatocytes at the single-cell level is possible and explored. Principal component analysis and subsequent partial least-squares (PLS) discriminant analysis is applied to distinguish endoderm induction from hepatic progenitor cells and matured hepatocyte-like cells. The data are well modeled by PLS with endoderm induction, hepatic progenitor cells, and mature hepatocyte-like cells able to be discriminated with very high sensitivity and specificity. This method provides a practical tool to monitor endoderm induction and has the potential to be applied for quality control of cell differentiation leading to hepatocyte formation.

Differentiation and upregulation of heat shock protein 70 induced by a subset of histone deacetylase inhibitors in mouse and human embryonic stem cells.

PubMed

Park, Jeong-A; Kim, Young-Eun; Seok, Hyun-Jeong; Park, Woo-Youn; Kwon, Hyung-Joo; Lee, Younghee

2011-03-01

Inhibiting histone deacetylase (HDAC) activity modulates the epigenetic status of cells, resulting in an alteration of gene expression and cellular function. Here, we investigated the effects of HDAC inhibitors on mouse embryonic stem (ES) cells. The HDAC inhibitors trichostatin A, suberoylanilide hydroxamic acid, sodium butyrate, and valproic acid induced early differentiation of mouse ES cells and triggered induction of heatshock protein (HSP)70. In contrast, class III HDAC inhibitors failed to induce differentiation or HSP70 expression. Transcriptional upregulation of HSP70 was confirmed by mRNA expression analysis, an inhibitor study, and chromatin immunoprecipitation. HSP70 induction was dependent on the SAPK/ JNK, p38, and PI3K/Akt pathways. Differentiation and induction of HSP70 by a subset of HDAC inhibitors was also examined in human ES cells, which suggests that the phenomenon generally occurs in ES cells. A better understanding of the effects of HDAC inhibitors may give more insight into their application in stem cell biology.

40 CFR 180.641 - Spirotetramat; tolerances for residues.

Code of Federal Regulations, 2014 CFR

2014-07-01

... growing, except strawberry, subgroup 13-07H 0.30 Black sapote 0.60 Brassica, head and stem, subgroup 5A 2.... registrations for cotton or strawberry. (2) Tolerances are also established for residues of the insecticide...

The Kraken Wakes: induced EMT as a driver of tumour aggression and poor outcome.

PubMed

Redfern, Andrew D; Spalding, Lisa J; Thompson, Erik W

2018-06-08

Epithelial mesenchymal transition (EMT) describes the shift of cells from an epithelial form to a contact independent, migratory, mesenchymal form. In cancer the change is linked to invasion and metastasis. Tumour conditions, including hypoxia, acidosis and a range of treatments can trigger EMT, which is implicated in the subsequent development of resistance to those same treatments. Consequently, the degree to which EMT occurs may underpin the entire course of tumour progression and treatment response in a patient. In this review we look past the protective effect of EMT against the initial treatment, to the role of the mesenchymal state, once triggered, in promoting disease growth, spread and future treatment insensitivity. In patients a correlation was found between the propensity of a treatment to induce EMT and failure of that treatment to provide a survival benefit, implicating EMT induction in accelerated tumour progression after treatment cessation. Looking to the mechanisms driving this detrimental effect; increased proliferation, suppressed apoptosis, stem cell induction, augmented angiogenesis, enhanced metastatic dissemination, and immune tolerance, can all result from treatment-induced EMT and could worsen outcome. Evidence also suggests EMT induction with earlier therapies attenuates benefits of later treatments. Looking beyond epithelial tumours, de-differentiation also has therapy-attenuating effects and reversal thereof may yield similar rewards. A range of potential therapies are in development that may address the diverse mechanisms and molecular control systems involved in EMT-induced accelerated progression. Considering the broad reaching effects of mesenchymal shift identified, successful deployment of such treatments could substantially improve patient outcomes.

A systematic review on the role of environmental toxicants in stem cells aging.

PubMed

Hodjat, Mahshid; Rezvanfar, Mohammad Amin; Abdollahi, Mohammad

2015-12-01

Stem cells are an important target for environmental toxicants. As they are the main source for replenishing of organs in the body, any changes in their normal function could affect the regenerative potential of organs, leading to the appearance of age-related disease and acceleration of the aging process. Environmental toxicants could exert their adverse effect on stem cell function via multiple cellular and molecular mechanisms, resulting in changes in the stem cell differentiation fate and cell transformation, and reduced self-renewal capacity, as well as induction of stress-induced cellular senescence. The present review focuses on the effect of environmental toxicants on stem cell function associated with the aging process. We categorized environmental toxicants according to their preferred molecular mechanism of action on stem cells, including changes in genomic, epigenomic, and proteomic levels and enhancing oxidative stress. Pesticides, tobacco smoke, radiation and heavy metals are well-studied toxicants that cause stem cell dysfunction via induction of oxidative stress. Transgenerational epigenetic changes are the most important effects of a variety of toxicants on germ cells and embryos that are heritable and could affect health in the next several generations. A better understanding of the underlying mechanisms of toxicant-induced stem cell aging will help us to develop therapeutic intervention strategies against environmental aging. Meanwhile, more efforts are required to find the direct in vivo relationship between adverse effect of environmental toxicants and stem cell aging, leading to organismal aging. Copyright © 2015 Elsevier Ltd. All rights reserved.

Clinical-Grade Human Multipotent Adult Progenitor Cells Block CD8+ Cytotoxic T Lymphocytes

PubMed Central

Dekimpe, Emily; Van Woensel, Matthias; Roobrouck, Valerie D.; Bullens, Dominique M.; Pinxteren, Jef; Verfaillie, Catherine M.; Van Gool, Stefaan W.

2016-01-01

MultiStem cells are clinical-grade multipotent adult bone marrow-derived progenitor cells (MAPCs), with extensive replication potential and broader differentiation capacity compared with mesenchymal stem cells. Human MAPCs suppress T-cell proliferation induced by alloantigens and mutually interact with allogeneic natural killer cells. In this study, the interaction between MultiStem and CD8+ cytotoxic T lymphocytes (CTLs) was addressed for the first time. In an in vitro setting, the immunogenicity of MultiStem, the susceptibility of MultiStem toward CTL-mediated lysis, and its effects on CTL function were investigated. MultiStem was nonimmunogenic for alloreactive CTL induction and was—even after major histocompatibility complex class I upregulation—insensitive to alloantigen-specific CTL-mediated lysis. Furthermore, MultiStem reduced CTL proliferation and significantly decreased perforin expression during the T-cell activation phase. As a consequence, MultiStem dose-dependently impaired the induction of CTL function. These effects of MultiStem were mediated predominantly through contact-dependent mechanisms. Moreover, MultiStem cells considerably influenced the expression of T-cell activation markers CD25, CD69, and human leukocyte antigen-DR. The MultiStem-induced CD8−CD69+ T-cell population displayed a suppressive effect on the induction of CTL function during a subsequent mixed-lymphocyte culture. Finally, the killer activity of activated antigen-specific CTLs during their cytolytic effector phase was also diminished in the presence of MultiStem. This study confirms that these clinical-grade MAPCs are an immune-modulating population that inhibits CTL activation and effector responses and are, consequently, a highly valuable cell population for adoptive immunosuppressive therapy in diseases where damage is induced by CTLs. Significance Because multipotent adult progenitor cells (MAPCs) are among the noteworthy adult mesenchymal stem cell populations for immune therapy and have the advantage over mesenchymal stem cells (MSCs) of large-scale manufacturing and banking potential and thus prompt availability, it is important to understand how MAPCs interact with immune cells to validate their widespread therapeutic applicability. Cytotoxic immune effector cells play a crucial role in immune homeostasis and in the pathogenesis of some autoimmune diseases. This study assessed for the first time the in vitro influence of a clinical-grade human MAPC product (MultiStem) on the cytotoxic function of CD8+ T cells (CTLs) by evaluating the immunogenicity of MAPCs and the susceptibility of MAPCs toward CTL-mediated lysis and by analyzing the mechanism of MAPC-mediated modulation of CTL functionality. These results may represent a highly relevant contribution to the current knowledge and, in combination with the results of future phase II/III trials using MultiStem, could lead to an intriguing continuation of stem cell-based research for immunotherapy. PMID:27465071

Clinical-Grade Human Multipotent Adult Progenitor Cells Block CD8+ Cytotoxic T Lymphocytes.

PubMed

Plessers, Jeroen; Dekimpe, Emily; Van Woensel, Matthias; Roobrouck, Valerie D; Bullens, Dominique M; Pinxteren, Jef; Verfaillie, Catherine M; Van Gool, Stefaan W

2016-12-01

: MultiStem cells are clinical-grade multipotent adult bone marrow-derived progenitor cells (MAPCs), with extensive replication potential and broader differentiation capacity compared with mesenchymal stem cells. Human MAPCs suppress T-cell proliferation induced by alloantigens and mutually interact with allogeneic natural killer cells. In this study, the interaction between MultiStem and CD8 + cytotoxic T lymphocytes (CTLs) was addressed for the first time. In an in vitro setting, the immunogenicity of MultiStem, the susceptibility of MultiStem toward CTL-mediated lysis, and its effects on CTL function were investigated. MultiStem was nonimmunogenic for alloreactive CTL induction and was-even after major histocompatibility complex class I upregulation-insensitive to alloantigen-specific CTL-mediated lysis. Furthermore, MultiStem reduced CTL proliferation and significantly decreased perforin expression during the T-cell activation phase. As a consequence, MultiStem dose-dependently impaired the induction of CTL function. These effects of MultiStem were mediated predominantly through contact-dependent mechanisms. Moreover, MultiStem cells considerably influenced the expression of T-cell activation markers CD25, CD69, and human leukocyte antigen-DR. The MultiStem-induced CD8 - CD69 + T-cell population displayed a suppressive effect on the induction of CTL function during a subsequent mixed-lymphocyte culture. Finally, the killer activity of activated antigen-specific CTLs during their cytolytic effector phase was also diminished in the presence of MultiStem. This study confirms that these clinical-grade MAPCs are an immune-modulating population that inhibits CTL activation and effector responses and are, consequently, a highly valuable cell population for adoptive immunosuppressive therapy in diseases where damage is induced by CTLs. Because multipotent adult progenitor cells (MAPCs) are among the noteworthy adult mesenchymal stem cell populations for immune therapy and have the advantage over mesenchymal stem cells (MSCs) of large-scale manufacturing and banking potential and thus prompt availability, it is important to understand how MAPCs interact with immune cells to validate their widespread therapeutic applicability. Cytotoxic immune effector cells play a crucial role in immune homeostasis and in the pathogenesis of some autoimmune diseases. This study assessed for the first time the in vitro influence of a clinical-grade human MAPC product (MultiStem) on the cytotoxic function of CD8 + T cells (CTLs) by evaluating the immunogenicity of MAPCs and the susceptibility of MAPCs toward CTL-mediated lysis and by analyzing the mechanism of MAPC-mediated modulation of CTL functionality. These results may represent a highly relevant contribution to the current knowledge and, in combination with the results of future phase II/III trials using MultiStem, could lead to an intriguing continuation of stem cell-based research for immunotherapy. ©AlphaMed Press.

A miRNA181a/NFAT5 axis links impaired T cell tolerance induction with autoimmune type 1 diabetes

PubMed Central

Serr, Isabelle; Scherm, Martin G.; Zahm, Adam M.; Schug, Jonathan; Flynn, Victoria K.; Hippich, Markus; Kälin, Stefanie; Becker, Maike; Achenbach, Peter; Nikolaev, Alexei; Gerlach, Katharina; Liebsch, Nicole; Loretz, Brigitta; Lehr, Claus-Michael; Kirchner, Benedikt; Spornraft, Melanie; Haase, Bettina; Segars, James; Küper, Christoph; Palmisano, Ralf; Waisman, Ari; Willis, Richard A.; Kim, Wan-Uk; Weigmann, Benno; Kaestner, Klaus H.; Ziegler, Anette-Gabriele; Daniel, Carolin

2018-01-01

Molecular checkpoints that trigger the onset of islet autoimmunity or progression to human type 1 diabetes (T1D) are incompletely understood. Using T cells from children at an early stage of islet autoimmunity without clinical T1D, we find that a microRNA181a (miRNA181a)–mediated increase in signal strength of stimulation and costimulation links nuclear factor of activated T cells 5 (NFAT5) with impaired tolerance induction and autoimmune activation. We show that enhancing miRNA181a activity increases NFAT5 expression while inhibiting FOXP3+ regulatory T cell (Treg) induction in vitro. Accordingly, Treg induction is improved using T cells from NFAT5 knockout (NFAT5ko) animals, whereas altering miRNA181a activity does not affect Treg induction in NFAT5ko T cells. Moreover, high costimulatory signals result in phosphoinositide 3-kinase (PI3K)–mediated NFAT5, which interferes with FoxP3+ Treg induction. Blocking miRNA181a or NFAT5 increases Treg induction in murine and humanized models and reduces murine islet autoimmunity in vivo. These findings suggest targeting miRNA181a and/or NFAT5 signaling for the development of innovative personalized medicines to limit islet autoimmunity. PMID:29298866

Stem cells in kidney regeneration.

PubMed

Yokote, Shinya; Yokoo, Takashi

2012-01-01

Currently many efforts are being made to apply regenerative medicine to kidney diseases using several types of stem/progenitor cells, such as mesenchymal stem cells, renal stem/progenitor cells, embryonic stem cells and induced pluripotent stem cells. Stem cells have the ability to repair injured organs and ameliorate damaged function. The strategy for kidney tissue repair is the recruitment of stem cells and soluble reparative factors to the kidney to elicit tissue repair and the induction of dedifferentiation of resident renal cells. On the other hand, where renal structure is totally disrupted, absolute kidney organ regeneration is needed to rebuild a whole functional kidney. In this review, we describe current advances in stem cell research for kidney tissue repair and de novo organ regeneration.

The usefulness of three-dimensional cell culture in induction of cancer stem cells from esophageal squamous cell carcinoma cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujiwara, Daisuke; Kato, Kazunori, E-mail: kzkatou@juntendo.ac.jp; Department of Atopy Research Center, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421

2013-05-17

Highlights: •Spheroids were created from esophageal carcinoma cells using NanoCulture® Plates. •The proportion of strongly ALDH-positive cells increased in 3-D culture. •Expression of cancer stem cell-related genes was enhanced in 3-D culture. •CA-9 expression was enhanced, suggesting hypoxia had been induced in 3-D culture. •Drug resistance was increased. 3-D culture is useful for inducing cancer stem cells. -- Abstract: In recent years, research on resistance to chemotherapy and radiotherapy in cancer treatment has come under the spotlight, and researchers have also begun investigating the relationship between resistance and cancer stem cells. Cancer stem cells are assumed to be present inmore » esophageal cancer, but experimental methods for identification and culture of these cells have not yet been established. To solve this problem, we created spheroids using a NanoCulture® Plate (NCP) for 3-dimensional (3-D) cell culture, which was designed as a means for experimentally reproducing the 3-D structures found in the body. We investigated the potential for induction of cancer stem cells from esophageal cancer cells. Using flow cytometry we analyzed the expression of surface antigen markers CD44, CD133, CD338 (ABCG2), CD318 (CDCP1), and CD326 (EpCAM), which are known cancer stem cell markers. None of these surface antigen markers showed enhanced expression in 3-D cultured cells. We then analyzed aldehyde dehydrogenase (ALDH) enzymatic activity using the ALDEFLUOR reagent, which can identify immature cells such as stem cells and precursor cells. 3-D-cultured cells were strongly positive for ALDH enzyme activity. We also analyzed the expression of the stem cell-related genes Sox-2, Nanog, Oct3/4, and Lin28 using RT-PCR. Expression of Sox-2, Nanog, and Lin28 was enhanced. Analysis of expression of the hypoxic surface antigen marker carbonic anhydrase-9 (CA-9), which is an indicator of cancer stem cell induction and maintenance, revealed that CA-9 expression was enhanced, suggesting that hypoxia had been induced. Comparison of cancer drug resistance using cisplatin and doxorubicin in 3-D-cultured esophageal cancer cells showed that cancer drug resistance had increased. These results indicate that 3-D culture of esophageal squamous cell carcinoma lines is a useful method for inducing cancer stem cells.« less

The therapeutic potential of cell identity reprogramming for the treatment of aging-related neurodegenerative disorders.

PubMed

Smith, Derek K; He, Miao; Zhang, Chun-Li; Zheng, Jialin C

2017-10-01

Neural cell identity reprogramming strategies aim to treat age-related neurodegenerative disorders with newly induced neurons that regenerate neural architecture and functional circuits in vivo. The isolation and neural differentiation of pluripotent embryonic stem cells provided the first in vitro models of human neurodegenerative disease. Investigation into the molecular mechanisms underlying stem cell pluripotency revealed that somatic cells could be reprogrammed to induced pluripotent stem cells (iPSCs) and these cells could be used to model Alzheimer disease, amyotrophic lateral sclerosis, Huntington disease, and Parkinson disease. Additional neural precursor and direct transdifferentiation strategies further enabled the induction of diverse neural linages and neuron subtypes both in vitro and in vivo. In this review, we highlight neural induction strategies that utilize stem cells, iPSCs, and lineage reprogramming to model or treat age-related neurodegenerative diseases, as well as, the clinical challenges related to neural transplantation and in vivo reprogramming strategies. Copyright © 2016. Published by Elsevier Ltd.

Orphan nuclear receptor TLX recruits histone deacetylases to repress transcription and regulate neural stem cell proliferation.

PubMed

Sun, Guoqiang; Yu, Ruth T; Evans, Ronald M; Shi, Yanhong

2007-09-25

TLX is a transcription factor that is essential for neural stem cell proliferation and self-renewal. However, the molecular mechanism of TLX-mediated neural stem cell proliferation and self-renewal is largely unknown. We show here that TLX recruits histone deacetylases (HDACs) to its downstream target genes to repress their transcription, which in turn regulates neural stem cell proliferation. TLX interacts with HDAC3 and HDAC5 in neural stem cells. The HDAC5-interaction domain was mapped to TLX residues 359-385, which contains a conserved nuclear receptor-coregulator interaction motif IXXLL. Both HDAC3 and HDAC5 have been shown to be recruited to the promoters of TLX target genes along with TLX in neural stem cells. Recruitment of HDACs led to transcriptional repression of TLX target genes, the cyclin-dependent kinase inhibitor, p21(CIP1/WAF1)(p21), and the tumor suppressor gene, pten. Either inhibition of HDAC activity or knockdown of HDAC expression led to marked induction of p21 and pten gene expression and dramatically reduced neural stem cell proliferation, suggesting that the TLX-interacting HDACs play an important role in neural stem cell proliferation. Moreover, expression of a TLX peptide containing the minimal HDAC5 interaction domain disrupted the TLX-HDAC5 interaction. Disruption of this interaction led to significant induction of p21 and pten gene expression and to dramatic inhibition of neural stem cell proliferation. Taken together, these findings demonstrate a mechanism for neural stem cell proliferation through transcriptional repression of p21 and pten gene expression by TLX-HDAC interactions.

Heme oxygenase-1, carbon monoxide, and bilirubin induce tolerance in recipients toward islet allografts by modulating T regulatory cells.

PubMed

Lee, Soo Sun; Gao, Wenda; Mazzola, Silvia; Thomas, Michael N; Csizmadia, Eva; Otterbein, Leo E; Bach, Fritz H; Wang, Hongjun

2007-11-01

Heme oxygenase-1 (HO-1) induction in, or carbon monoxide (CO), or bilirubin administration to, donors and/or recipients frequently lead to long-term survival (>100 days) of DBA/2 islets into B6AF1 recipients. We tested here whether similar treatments show value in a stronger immunogenetic combination, i.e., BALB/c to C57BL/6, and attempted to elucidate the mechanism accounting for tolerance. Induction of HO-1, administering CO or bilirubin to the donor, the islets or the recipient, prolonged islet allograft survival to different extents. Combining all the above treatments (the "combined" protocol) led to survival for >100 days and antigen-specific tolerance to 60% of the transplanted grafts. A high level of forkhead box P3 (Foxp3) and transforming growth factor beta (TGF-beta) expression was detected in the long-term surviving grafts. With the combined protocol, significantly more T regulatory cells (Tregs) were observed surrounding islets 7 days following transplantation. No prolongation of graft survival was observed using the combined protocol when CD4+ CD25+ T cells were predepleted from the recipients before transplantation. In conclusion, our combined protocol led to long-term survival and tolerance to islets in the BALB/c to C57BL/6 combination by promoting Foxp3+ Tregs; these cells played a critical role in the induction and maintenance of tolerance in the recipient.

How much older are Appalachian oaks below-ground than above-ground?

Treesearch

Daniel J. Heggenstaller; Eric K. Zenner; Patrick H. Brose; Jerilynn E. Peck

2012-01-01

Young oaks (Quercus spp.) are known to invest more in early root growth than shoot growth, enabling seedlings to tolerate stem die-back and resprouting. The resulting disparity in age between above- and below-ground tissues has been previously demonstrated for seedling-sized stems, but not for successful canopy-ascending trees. We compared the age of stem cross...

Assessment of tolerance induction by Origanum vulgare L. essential oil or carvacrol in Pseudomonas aeruginosa cultivated in a meat-based broth and in a meat model.

PubMed

da Silva Luz, Isabelle; Gomes-Neto, Nelson Justino; Magnani, Marciane; de Souza, Evandro Leite

2015-12-01

This study assessed the efficacy of Origanum vulgare L. essential oil (OVEO) and carvacrol in inhibiting the growth of Pseudomonas aeruginosa ATCC 9027, as well as the development of direct tolerance and cross-tolerance when this bacterium was challenged with sublethal amounts of these substances in a meat-based broth and in a meat model. OVEO and carvacrol at their minimum inhibitory concentrations (MICs), 1/2 MIC and 1/4 MIC decreased the viable cell counts of P. aeruginosa in meat-based broth. Direct tolerance or cross-tolerance was not induced after exposure of the assayed bacterial strain to sublethal amounts of OVEO or carvacrol in meat-based broth and in an artificially contaminated ground beef. Bacterial cells progressively subcultured in meat-based broth with increasing amounts of the tested substances survived up to the MIC of OVEO and to 1/2 MIC of carvacrol. The results reveal a lack of induction of tolerance in P. aeruginosa by exposure to OVEO or carvacrol in meat-based broth and in a meat model. © The Author(s) 2014.

Simultaneous induction of jasmonic acid and disease-responsive genes signifies tolerance of American elm to Dutch elm disease

PubMed Central

Sherif , S. M.; Shukla, M. R.; Murch, S. J.; Bernier, L.; Saxena, P. K.

2016-01-01

Dutch elm disease (DED), caused by three fungal species in the genus Ophiostoma, is the most devastating disease of both native European and North American elm trees. Although many tolerant cultivars have been identified and released, the tolerance mechanisms are not well understood and true resistance has not yet been achieved. Here we show that the expression of disease-responsive genes in reactions leading to tolerance or susceptibility is significantly differentiated within the first 144 hours post-inoculation (hpi). Analysis of the levels of endogenous plant defense molecules such as jasmonic acid (JA) and salicylic acid (SA) in tolerant and susceptible American elm saplings suggested SA and methyl-jasmonate as potential defense response elicitors, which was further confirmed by field observations. However, the tolerant phenotype can be best characterized by a concurrent induction of JA and disease-responsive genes at 96 hpi. Molecular investigations indicated that the expression of fungal genes (i.e. cerato ulmin) was also modulated by endogenous SA and JA and this response was unique among aggressive and non-aggressive fungal strains. The present study not only provides better understanding of tolerance mechanisms to DED, but also represents a first, verified template for examining simultaneous transcriptomic changes during American elm-fungus interactions. PMID:26902398

New approaches to the prevention of organ allograft rejection and tolerance induction.

PubMed

Bagley, Jessamyn; Tian, Chaorui; Iacomini, John

2007-07-15

The therapeutic use of organ allograft transplantation is dependent on the discovery and clinical application of immunologic strategies to blunt the immune response and prevent graft rejection. It was the discovery of powerful immunotherapeutics such as cyclosporine A and rapamycin that has allowed for the widespread use of organ transplantation to treat organ failure. However, despite the attainment of impressive survival rates 1 year after organ transplantation, a significant number of organ allografts are lost to immune-mediated chronic rejection. Furthermore, significant morbidity and mortality can be associated with the use of currently available immunosuppressive regimens. Thus, the development of novel approaches to prevent of organ allograft rejection remains extremely important. Here we discuss two promising and novel avenues of research. First, the discovery and characterization of naturally occurring immune inhibitory signals have led to recent research aimed at exploiting these pathways to induce peripheral tolerance to alloantigen. Furthermore, we discuss new approaches to the induction of donor-specific tolerance by induction of molecular chimerism and the transfer of alloantigen-expressing mature T cells.

Comparison of 2D and 3D neural induction methods for the generation of neural progenitor cells from human induced pluripotent stem cells.

PubMed

Chandrasekaran, Abinaya; Avci, Hasan X; Ochalek, Anna; Rösingh, Lone N; Molnár, Kinga; László, Lajos; Bellák, Tamás; Téglási, Annamária; Pesti, Krisztina; Mike, Arpad; Phanthong, Phetcharat; Bíró, Orsolya; Hall, Vanessa; Kitiyanant, Narisorn; Krause, Karl-Heinz; Kobolák, Julianna; Dinnyés, András

2017-12-01

Neural progenitor cells (NPCs) from human induced pluripotent stem cells (hiPSCs) are frequently induced using 3D culture methodologies however, it is unknown whether spheroid-based (3D) neural induction is actually superior to monolayer (2D) neural induction. Our aim was to compare the efficiency of 2D induction with 3D induction method in their ability to generate NPCs, and subsequently neurons and astrocytes. Neural differentiation was analysed at the protein level qualitatively by immunocytochemistry and quantitatively by flow cytometry for NPC (SOX1, PAX6, NESTIN), neuronal (MAP2, TUBB3), cortical layer (TBR1, CUX1) and glial markers (SOX9, GFAP, AQP4). Electron microscopy demonstrated that both methods resulted in morphologically similar neural rosettes. However, quantification of NPCs derived from 3D neural induction exhibited an increase in the number of PAX6/NESTIN double positive cells and the derived neurons exhibited longer neurites. In contrast, 2D neural induction resulted in more SOX1 positive cells. While 2D monolayer induction resulted in slightly less mature neurons, at an early stage of differentiation, the patch clamp analysis failed to reveal any significant differences between the electrophysiological properties between the two induction methods. In conclusion, 3D neural induction increases the yield of PAX6 + /NESTIN + cells and gives rise to neurons with longer neurites, which might be an advantage for the production of forebrain cortical neurons, highlighting the potential of 3D neural induction, independent of iPSCs' genetic background. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Induction of dopaminergic neurons from human Wharton's jelly mesenchymal stem cell by forskolin.

PubMed

Paldino, Emanuela; Cenciarelli, Carlo; Giampaolo, Adele; Milazzo, Luisa; Pescatori, Mario; Hassan, Hamisa Jane; Casalbore, Patrizia

2014-02-01

The purpose of this study was to investigate the Wharton's jelly mesenchymal stem cells differentiation ability toward neuronal fate. Human Wharton's jelly mesenchymal stem cells (hWJMSC) have been isolated from human umbilical cord of full-term births and characterized by flow cytometry analysis for their stem mesenchymal properties through specific surface markers expression (CD73, CD90, and CD105). hWJMSC mesodermal lineage differentiation ability and karyotype analysis were assessed. The trans-differentiation of hWJMSC into neural lineage was investigated in presence of forskolin, an agent known to increase the intracellular levels of cAMP. A molecular profile of differentiated hWJMSC was performed by microarray technology which revealed 1,532 statistically significant modulated genes respect to control cells. Most of these genes are mainly involved in functional neuronal signaling pathways and part of them are specifically required for the neuronal dopaminergic induction. The acquisition of the dopaminergic phenotype was evaluated via immunocytochemistry and Western blot analysis revealed the significant induction of Nurr1, NeuroD1, and TH proteins expression in forskolin-induced hWJMSC. Moreover, the treatment with forskolin promoted, in hWJMSC, a strong upregulation of the neurotrophin Trk receptors related to the high release of brain-derived neurotrophic factor. Taken together these findings show that hWJMSC may be represent an optimal therapeutic strategy for neurological diseases. © 2013 Wiley Periodicals, Inc.

Induction of human embryonic and induced pluripotent stem cells into urothelium.

PubMed

Osborn, Stephanie L; Thangappan, Ravikumar; Luria, Ayala; Lee, Justin H; Nolta, Jan; Kurzrock, Eric A

2014-05-01

In vitro generation of human urothelium from stem cells would be a major advancement in the regenerative medicine field, providing alternate nonurologic and/or nonautologous tissue sources for bladder grafts. Such a model would also help decipher the mechanisms of urothelial differentiation and would facilitate investigation of deviated differentiation of normal progenitors into urothelial cancer stem cells, perhaps elucidating areas of intervention for improved treatments. Thus far, in vitro derivation of urothelium from human embryonic stem cells (hESCs) or human induced pluripotent stem (hiPS) cells has not been reported. The goal of this work was to develop an efficient in vitro protocol for the induction of hESCs into urothelium through an intermediary definitive endoderm step and free of matrices and cell contact. During directed differentiation in a urothelial-specific medium ("Uromedium"), hESCs produced up to 60% urothelium, as determined by uroplakin expression; subsequent propagation selected for 90% urothelium. Alteration of the epithelial and mesenchymal cell signaling contribution through noncell contact coculture or conditioned media did not enhance the production of urothelium. Temporospatial evaluation of transcription factors known to be involved in urothelial specification showed association of IRF1, GET1, and GATA4 with uroplakin expression. Additional hESC and hiPS cell lines could also be induced into urothelium using this in vitro system. These results demonstrate that derivation and propagation of urothelium from hESCs and hiPS cells can be efficiently accomplished in vitro in the absence of matrices, cell contact, or adult cell signaling and that the induction process appears to mimic normal differentiation.

Induction of Human Embryonic and Induced Pluripotent Stem Cells Into Urothelium

PubMed Central

Osborn, Stephanie L.; Thangappan, Ravikumar; Luria, Ayala; Lee, Justin H.; Nolta, Jan

2014-01-01

In vitro generation of human urothelium from stem cells would be a major advancement in the regenerative medicine field, providing alternate nonurologic and/or nonautologous tissue sources for bladder grafts. Such a model would also help decipher the mechanisms of urothelial differentiation and would facilitate investigation of deviated differentiation of normal progenitors into urothelial cancer stem cells, perhaps elucidating areas of intervention for improved treatments. Thus far, in vitro derivation of urothelium from human embryonic stem cells (hESCs) or human induced pluripotent stem (hiPS) cells has not been reported. The goal of this work was to develop an efficient in vitro protocol for the induction of hESCs into urothelium through an intermediary definitive endoderm step and free of matrices and cell contact. During directed differentiation in a urothelial-specific medium (“Uromedium”), hESCs produced up to 60% urothelium, as determined by uroplakin expression; subsequent propagation selected for 90% urothelium. Alteration of the epithelial and mesenchymal cell signaling contribution through noncell contact coculture or conditioned media did not enhance the production of urothelium. Temporospatial evaluation of transcription factors known to be involved in urothelial specification showed association of IRF1, GET1, and GATA4 with uroplakin expression. Additional hESC and hiPS cell lines could also be induced into urothelium using this in vitro system. These results demonstrate that derivation and propagation of urothelium from hESCs and hiPS cells can be efficiently accomplished in vitro in the absence of matrices, cell contact, or adult cell signaling and that the induction process appears to mimic normal differentiation. PMID:24657961

Overcoming the response plateau in multiple myeloma: a novel bortezomib-based strategy for secondary induction and high-yield CD34+ stem cell mobilization.

PubMed

Niesvizky, Ruben; Mark, Tomer M; Ward, Maureen; Jayabalan, David S; Pearse, Roger N; Manco, Megan; Stern, Jessica; Christos, Paul J; Mathews, Lena; Shore, Tsiporah B; Zafar, Faiza; Pekle, Karen; Xiang, Zhaoying; Ely, Scott; Skerret, Donna; Chen-Kiang, Selina; Coleman, Morton; Lane, Maureen E

2013-03-15

This phase II study evaluated bortezomib-based secondary induction and stem cell mobilization in 38 transplant-eligible patients with myeloma who had an incomplete and stalled response to, or had relapsed after, previous immunomodulatory drug-based induction. Patients received up to six 21-day cycles of bortezomib plus dexamethasone, with added liposomal doxorubicin for patients not achieving partial response or better by cycle 2 or very good partial response or better (≥VGPR) by cycle 4 (DoVeD), followed by bortezomib, high-dose cyclophosphamide, and filgrastim mobilization. Gene expression/signaling pathway analyses were conducted in purified CD34+ cells after bortezomib-based mobilization and compared against patients who received only filgrastim ± cyclophosphamide. Plasma samples were similarly analyzed for quantification of associated protein markers. The response rate to DoVeD relative to the pre-DoVeD baseline was 61%, including 39% ≥ VGPR. Deeper responses were achieved in 10 of 27 patients who received bortezomib-based mobilization; postmobilization response rate was 96%, including 48% ≥ VGPR, relative to the pre-DoVeD baseline. Median CD34+ cell yield was 23.2 × 10(6) cells/kg (median of 1 apheresis session). After a median follow-up of 46.6 months, median progression-free survival was 47.1 months from DoVeD initiation; 5-year overall survival rate was 76.4%. Grade ≥ 3 adverse events included thrombocytopenia (13%), hand-foot syndrome (11%), peripheral neuropathy (8%), and neutropenia (5%). Bortezomib-based mobilization was associated with modulated expression of genes involved in stem cell migration. Bortezomib-based secondary induction and mobilization could represent an alternative strategy for elimination of tumor burden in immunomodulatory drug-resistant patients that does not impact stem cell yield.

Multiscale reconstruction of a synthetic biomimetic micro-niche for enhancing and monitoring the differentiation of stem cells.

PubMed

Li, Rui; Li, Jinming; Xu, Jianbin; Hong Wong, Dexter Siu; Chen, Xiaoyu; Yuan, Weihao; Bian, Liming

2018-05-04

Stem cells reside in a three-dimensional (3D) niche microenvironment, which provides specific cues, including cell-matrix interactions and soluble factors, that are essential to the differentiation of stem cells in vivo. Herein we demonstrate a general approach to the synthetic reconstruction of 3D biomimetic niche environment of stem cells by the multiscale combination of macroscopic porous hydrogels and a nanoscale upconversion nanoparticles (UCNP)-based nanocomplex. The porous biopolymeric hydrogels emulate the spongy bone microstructure and provide 3D environment conducive to the differentiation of seeded stem cells. The UCNP-based nanocomplex (Pur-UCNP-peptide-FITC), which is stably encapsulated in the porous hydrogels, emulates the repertoire of inductive factors in bone matrix by maintaining localized long-term delivery of inductive small molecules. The nanocomplex also generates biomarker-specific reporting emissions that correlate with the extent and stage of differentiation of the stem cells in synthetic niche, thereby allowing long-term tracking of stem cell fate in a non-contact, non-destructive, and potentially high-throughput manner in living cultures. To the best of our knowledge, this is first demonstration of synthetic niche reconstruction. The modular nature of this synthetic niche platform allows various parameters to be easily tuned to accommodate a variety of fundamental studies of dynamic cellular events under controlled settings. Copyright © 2018 Elsevier Ltd. All rights reserved.

Kidney versus Islet Allograft Survival after Induction of Mixed Chimerism with Combined Donor Bone Marrow Transplantation

PubMed Central

Oura, Tetsu; Ko, Dicken S.C.; Boskovic, Svjetlan; O'Neil, John J.; Chipashvili, Vaja; Koulmanda, Maria; Hotta, Kiyohiko; Kawai, Kento; Nadazdin, Ognjenka; Smith, R. Neal; Cosimi, A. B.; Kawai, Tatsuo

2016-01-01

Background We have previously reported successful induction of transient mixed chimerism and long-term acceptance of renal allografts in MHC-mismatched nonhuman primates. In this study, we attempted to extend this tolerance induction approach to islet allografts. Methods A total of eight recipients underwent MHC mismatched combined islet and bone marrow (BM) transplantation after induction of diabetes by streptozotocin. Three recipients were treated after a nonmyeloablative conditioning regimen that includes low dose total body and thymic irradiation, horse ATG (Atgam), six doses of anti-CD154 monoclonal antibody (mAb) and a one month course of cyclosporine (CyA) (Islet-A). In Islet-B, anti-CD8 mAb was administered in place of CyA. In Islet-C, two recipients were treated with Islet-B but without Atgam. The results were compared with previously reported results of eight cynomolgus monkeys that received combined kidney and bone marrow transplantation (Kidney-A) following the same conditioning regimen used in Islet-A. Results The majority of Kidney/BM recipients achieved long-term renal allograft survival after induction of transient chimerism. However, prolonged islet survival was not achieved in similarly conditioned Islet/BM recipients (Islet-A), despite induction of comparable levels of chimerism. In order to rule out islet allograft loss due to calcineurin inhibitor (CNI) toxicity, three recipients were treated with anti-CD8 mAb in place of CNI. Although these recipients developed significantly superior mixed chimerism and more prolonged islet allograft survival (61, 103, and 113 days), islet function was lost soon after the disappearance of chimerism. In Islet-C recipients, neither prolonged chimerism nor islet survival was observed (30 and 40 days). Conclusion Significant improvement of mixed chimerism induction and islet allograft survival were achieved with a CNI-free regimen that includes anti-CD8 mAb. However, unlike the kidney allograft, islet allograft tolerance was not induced with transient chimerism. Induction of more durable mixed chimerism may be necessary for induction of islet allograft tolerance. PMID:26337731

Misalignment tolerable coil structure for biomedical applications with wireless power transfer.

PubMed

Chow, Jeff P W; Chen, Nan; Chung, Henry S H; Chan, Leanne L H

2013-01-01

Coil-misalignment is one of the major hurdles for inductively coupled wireless power transfer in applications like retinal prosthesis. Weak magnetic flux linkage due to coil misalignments would significantly impair the power efficiency. A novel receiver configuration with high misalignment tolerance is presented in this paper. The proposed receiver is composed of two receiver coils placed orthogonally, so as to reduce the variation of mutual inductance between transmitting and receiving coils under misalignment conditions. Three different receiver coil structures are analyzed and compared using the same length of wire. Theoretical predictions have been confirmed with measurement results.

Efficient induction of dopaminergic neuron differentiation from induced pluripotent stem cells reveals impaired mitophagy in PARK2 neurons.

PubMed

Suzuki, Sadafumi; Akamatsu, Wado; Kisa, Fumihiko; Sone, Takefumi; Ishikawa, Kei-Ichi; Kuzumaki, Naoko; Katayama, Hiroyuki; Miyawaki, Atsushi; Hattori, Nobutaka; Okano, Hideyuki

2017-01-29

Patient-specific induced pluripotent stem cells (iPSCs) show promise for use as tools for in vitro modeling of Parkinson's disease. We sought to improve the efficiency of dopaminergic (DA) neuron induction from iPSCs by the using surface markers expressed in DA progenitors to increase the significance of the phenotypic analysis. By sorting for a CD184 high /CD44 - fraction during neural differentiation, we obtained a population of cells that were enriched in DA neuron precursor cells and achieved higher differentiation efficiencies than those obtained through the same protocol without sorting. This high efficiency method of DA neuronal induction enabled reliable detection of reactive oxygen species (ROS) accumulation and vulnerable phenotypes in PARK2 iPSCs-derived DA neurons. We additionally established a quantitative system using the mt-mKeima reporter system to monitor mitophagy in which mitochondria fuse with lysosomes and, by combining this system with the method of DA neuronal induction described above, determined that mitophagy is impaired in PARK2 neurons. These findings suggest that the efficiency of DA neuron induction is important for the precise detection of cellular phenotypes in modeling Parkinson's disease. Copyright © 2016. Published by Elsevier Inc.

Change in the Content of Immunoproteasomes and Macrophages in Rat Liver At the Induction of Donor-Specific Tolerance.

PubMed

Karpova, Ya D; Ustichenko, V D; Alabedal'karim, N M; Stepanova, A A; Lyupina, Yu V; Boguslavski, K I; Bozhok, G A; Sharova, N P

2017-01-01

Induction of donor specific tolerance (DST) by the introduction of donor cells into a recipient's portal vein is one of the approaches used to solve the problem of transplant engraftment. However, the mechanism of DST development remains unclear to this moment. In the present work, we first studied the change in the content of immunoproteasomes and macrophages of the liver at early stages of the development of allospecific portal tolerance in rats by Western blotting and flow cytofluorimetry. On the basis of the data obtained, we can conclude that the induction of DST is an active process characterized by two phases during which the level of the proteasome immune subunits LMP2 and LMP7 in liver mononuclear cells, including Kupffer cells, and the number of Kupffer cells change. The first phase lasts up to 5 days after the beginning of DST induction; the second phase - from 5 to 14 days. In both phases, the level of the subunits LMP2 and LMP7 in the total pool of mononuclear cells and Kupffer cells increases, with maximum values on days 1 and 7. In addition, the total number of Kupffer cells increases in both phases with a shift in several days. The most noticeable changes take place in the second phase. The third day is characterized by a lower content of mononuclear cells expressing immunoproteasomes compared to the control value in native animals. Presumably, at this time point a "window of opportunity" appears for subsequent filling of an empty niche with cells of different subpopulations and, depending on this fact, the development of tolerance or rejection. The results obtained raise the new tasks of finding ways to influence the cellular composition in the liver and the expression of immunoproteasomes on the third day after the beginning of DST induction to block the development of rejection.

I-SceI-mediated double-strand break does not increase the frequency of homologous recombination at the Dct locus in mouse embryonic stem cells.

PubMed

Fenina, Myriam; Simon-Chazottes, Dominique; Vandormael-Pournin, Sandrine; Soueid, Jihane; Langa, Francina; Cohen-Tannoudji, Michel; Bernard, Bruno A; Panthier, Jean-Jacques

2012-01-01

Targeted induction of double-strand breaks (DSBs) at natural endogenous loci was shown to increase the rate of gene replacement by homologous recombination in mouse embryonic stem cells. The gene encoding dopachrome tautomerase (Dct) is specifically expressed in melanocytes and their precursors. To construct a genetic tool allowing the replacement of Dct gene by any gene of interest, we generated an embryonic stem cell line carrying the recognition site for the yeast I-SceI meganuclease embedded in the Dct genomic segment. The embryonic stem cell line was electroporated with an I-SceI expression plasmid, and a template for the DSB-repair process that carried sequence homologies to the Dct target. The I-SceI meganuclease was indeed able to introduce a DSB at the Dct locus in live embryonic stem cells. However, the level of gene targeting was not improved by the DSB induction, indicating a limited capacity of I-SceI to mediate homologous recombination at the Dct locus. These data suggest that homologous recombination by meganuclease-induced DSB may be locus dependent in mammalian cells.

Recent thymic emigrants are tolerized in the absence of inflammation

PubMed Central

Friesen, Travis J.; Ji, Qingyong

2016-01-01

T cell development requires a period of postthymic maturation. Why this is the case has remained a mystery, particularly given the rigors of intrathymic developmental checkpoints, successfully traversed by only ∼5% of thymocytes. We now show that the first few weeks of T cell residence in the lymphoid periphery define a period of heightened susceptibility to tolerance induction to tissue-restricted antigens (TRAs), the outcome of which depends on the context in which recent thymic emigrants (RTEs) encounter antigen. After encounter with TRAs in the absence of inflammation, RTEs exhibited defects in proliferation, diminished cytokine production, elevated expression of anergy-associated genes, and diminished diabetogenicity. These properties were mirrored in vitro by enhanced RTE susceptibility to regulatory T cell–mediated suppression. In the presence of inflammation, RTEs and mature T cells were, in contrast, equally capable of inducing diabetes, proliferating, and producing cytokines. Thus, recirculating RTEs encounter TRAs during a transitional developmental stage that facilitates tolerance induction, but inflammation converts antigen-exposed, tolerance-prone RTEs into competent effector cells. PMID:27139493

T-cell receptor revision: friend or foe?

PubMed Central

Hale, J Scott; Fink, Pamela J

2010-01-01

T-cell receptor (TCR) revision is a process of tolerance induction by which peripheral T cells lose surface expression of an autoreactive TCR, reinduce expression of the recombinase machinery, rearrange genes encoding extrathymically generated TCRs for antigen, and express these new receptors on the cell surface. We discuss the evidence for this controversial tolerance mechanism below. Despite the apparent heresy of post-thymic gene rearrangement, we argue here that TCR revision follows the rules obeyed by maturing thymocytes undergoing gene recombination. Expression of the recombinase is carefully controlled both spatially and temporally, and may be initiated by loss of signals through surface TCRs. The resulting TCR repertoire is characterized by its diversity, self major histocompatibility complex restriction, self tolerance, and ability to mount productive immune responses specific for foreign antigens. Hence, TCR revision is a carefully regulated process of tolerance induction that can contribute to the protection of the individual against invading pathogens while preserving the integrity of self tissue. PMID:20201984

Physiological response of glandular-haired alfalfa to potato leafhopper (Hemiptera: Cicadellidae) injury.

PubMed

Lamp, W O; Alexander, L C; Nguyen, M

2007-02-01

Plant tolerance to herbivory is a key approach for managing pests. In alfalfa, Medicago sativa, the potato leafhopper, Empoasca fabae, is a major pest as a result of the cascade of plant responses to piercing-sucking injury. To identify tolerance to its injury based on alfalfa physiology, experiments were conducted in the field and greenhouse. In our comparison of the response of field-grown alfalfa cultivars to standardized leafhopper densities, net photosynthesis and transpiration rates of 'Geneva' leaves were reduced by 18 and 21%, respectively, by leafhopper presence compared with a rate change of <1% of resistant 'EverGreen' leaves. Under greenhouse conditions, alfalfa clones varied in their level of gas exchange (net photosynthesis and transpiration) and stem elongation responses to leafhopper injury. For example, in the comparison of seven clones, net photosynthesis declined an average of 40.7% with leafhopper injury, although individual clones varied from 26.6 to 74.3% reduction. Internode elongation after 2 d was 60.3% less on injured stems compared with healthy stems, but again, the individual clones varied from 17.3 to 91.9%. In a time-course study of selected clones, clones varied in their level of injury just after and 3 d after insect removal. Gas exchange responses of all clones recovered by 7 d after cessation of injury. In a choice test, leafhoppers spent similar amounts of time on the susceptible clone and the most tolerant clone; however, their precise feeding behaviors were not measured. Thus, the variable response of clones to injury may be either true physiological tolerance or antixenosis from a change in feeding behavior. This study showed putative tolerance to leafhopper injury among alfalfa genotypes, suggesting that tolerance could be the basis for crop protection in alfalfa from potato leafhopper injury.

Diabetes Is Reversed in a Murine Model by Marginal Mass Syngeneic Islet Transplantation Using a Subcutaneous Cell Pouch Device.

PubMed

Pepper, Andrew R; Pawlick, Rena; Gala-Lopez, Boris; MacGillivary, Amanda; Mazzuca, Delfina M; White, David J G; Toleikis, Philip M; Shapiro, A M James

2015-11-01

Islet transplantation is a successful β-cell replacement therapy for selected patients with type 1 diabetes mellitus. Although high rates of early insulin independence are achieved routinely, long-term function wanes over time. Intraportal transplantation is associated with procedural risks, requires multiple donors, and does not afford routine biopsy. Stem cell technologies may require potential for retrievability, and graft removal by hepatectomy is impractical. There is a clear clinical need for an alternative, optimized transplantation site. The subcutaneous space is a potential substitute, but transplantation of islets into this site has routinely failed to reverse diabetes. However, an implanted device, which becomes prevascularized before transplantation, may alter this equation. Syngeneic mouse islets were transplanted subcutaneously within Sernova Corp's Cell Pouch (CP). All recipients were preimplanted with CPs 4 weeks before diabetes induction and transplantation. After transplantation, recipients were monitored for glycemic control and glucose tolerance. Mouse islets transplanted into the CP routinely restored glycemic control with modest delay and responded well to glucose challenge, comparable to renal subcapsular islet grafts, despite a marginal islet dose, and normoglycemia was maintained until graft explantation. In contrast, islets transplanted subcutaneously alone failed to engraft. Islets within CPs stained positively for insulin, glucagon, and microvessels. The CP is biocompatible, forms an environment suitable for islet engraftment, and offers a potential alternative to the intraportal site for islet and future stem cell therapies.

Non-senescent Hydra tolerates severe disturbances in the nuclear lamina.

PubMed

Klimovich, Alexander; Rehm, Arvid; Wittlieb, Jörg; Herbst, Eva-Maria; Benavente, Ricardo; Bosch, Thomas C G

2018-05-10

The cnidarian Hydra is known for its unlimited lifespan and non-senescence, due to the indefinite self-renewal capacity of its stem cells. While proteins of the Lamin family are recognized as critical factors affecting senescence and longevity in human and mice, their putative role in the extreme longevity and non-senescence in long-living animals remains unknown. Here we analyze the role of a single lamin protein in non-senescence of Hydra . We demonstrate that proliferation of stem cells in Hydra is robust against the disturbance of Lamin expression and localization. While Lamin is indispensable for Hydra , the stem cells tolerate overexpression, downregulation and mislocalization of Lamin, and disturbances in the nuclear envelope structure. This extraordinary robustness may underlie the indefinite self-renewal capacity of stem cells and the non-senescence of Hydra . A relatively low complexity of the nuclear envelope architecture in basal Metazoa might allow for their extreme lifespans, while an increasing complexity of the nuclear architecture in bilaterians resulted in restricted lifespans.

Non-senescent Hydra tolerates severe disturbances in the nuclear lamina

PubMed Central

Rehm, Arvid; Wittlieb, Jörg; Herbst, Eva-Maria; Benavente, Ricardo

2018-01-01

The cnidarian Hydra is known for its unlimited lifespan and non-senescence, due to the indefinite self-renewal capacity of its stem cells. While proteins of the Lamin family are recognized as critical factors affecting senescence and longevity in human and mice, their putative role in the extreme longevity and non-senescence in long-living animals remains unknown. Here we analyze the role of a single lamin protein in non-senescence of Hydra. We demonstrate that proliferation of stem cells in Hydra is robust against the disturbance of Lamin expression and localization. While Lamin is indispensable for Hydra, the stem cells tolerate overexpression, downregulation and mislocalization of Lamin, and disturbances in the nuclear envelope structure. This extraordinary robustness may underlie the indefinite self-renewal capacity of stem cells and the non-senescence of Hydra. A relatively low complexity of the nuclear envelope architecture in basal Metazoa might allow for their extreme lifespans, while an increasing complexity of the nuclear architecture in bilaterians resulted in restricted lifespans. PMID:29754147

Gene expression analysis of human adipose tissue-derived stem cells during the initial steps of in vitro osteogenesis.

PubMed

Robert, Anny Waloski; Angulski, Addeli Bez Batti; Spangenberg, Lucia; Shigunov, Patrícia; Pereira, Isabela Tiemy; Bettes, Paulo Sergio Loiacono; Naya, Hugo; Correa, Alejandro; Dallagiovanna, Bruno; Stimamiglio, Marco Augusto

2018-03-16

Mesenchymal stem cells (MSCs) have been widely studied with regard to their potential use in cell therapy protocols and regenerative medicine. However, a better comprehension about the factors and molecular mechanisms driving cell differentiation is now mandatory to improve our chance to manipulate MSC behavior and to benefit future applications. In this work, we aimed to study gene regulatory networks at an early step of osteogenic differentiation. Therefore, we analyzed both the total mRNA and the mRNA fraction associated with polysomes on human adipose tissue-derived stem cells (hASCs) at 24 h of osteogenesis induction. The RNA-seq results evidenced that hASC fate is not compromised with osteogenesis at this time and that 21 days of continuous cell culture stimuli are necessary for full osteogenic differentiation of hASCs. Furthermore, early stages of osteogenesis induction involved gene regulation that was linked to the management of cell behavior in culture, such as the control of cell adhesion and proliferation. In conclusion, although discrete initial gene regulation related to osteogenesis occur, the first 24 h of induction is not sufficient to trigger and drive in vitro osteogenic differentiation of hASCs.

Orphan nuclear receptor TLX recruits histone deacetylases to repress transcription and regulate neural stem cell proliferation

PubMed Central

Sun, GuoQiang; Yu, Ruth T.; Evans, Ronald M.; Shi, Yanhong

2007-01-01

TLX is a transcription factor that is essential for neural stem cell proliferation and self-renewal. However, the molecular mechanism of TLX-mediated neural stem cell proliferation and self-renewal is largely unknown. We show here that TLX recruits histone deacetylases (HDACs) to its downstream target genes to repress their transcription, which in turn regulates neural stem cell proliferation. TLX interacts with HDAC3 and HDAC5 in neural stem cells. The HDAC5-interaction domain was mapped to TLX residues 359–385, which contains a conserved nuclear receptor–coregulator interaction motif IXXLL. Both HDAC3 and HDAC5 have been shown to be recruited to the promoters of TLX target genes along with TLX in neural stem cells. Recruitment of HDACs led to transcriptional repression of TLX target genes, the cyclin-dependent kinase inhibitor, p21CIP1/WAF1(p21), and the tumor suppressor gene, pten. Either inhibition of HDAC activity or knockdown of HDAC expression led to marked induction of p21 and pten gene expression and dramatically reduced neural stem cell proliferation, suggesting that the TLX-interacting HDACs play an important role in neural stem cell proliferation. Moreover, expression of a TLX peptide containing the minimal HDAC5 interaction domain disrupted the TLX–HDAC5 interaction. Disruption of this interaction led to significant induction of p21 and pten gene expression and to dramatic inhibition of neural stem cell proliferation. Taken together, these findings demonstrate a mechanism for neural stem cell proliferation through transcriptional repression of p21 and pten gene expression by TLX–HDAC interactions. PMID:17873065

Immunomodulatory Effects of Mixed Hematopoietic Chimerism: Immune Tolerance in Canine Model of Lung Transplantation

PubMed Central

Nash;, Richard A.; Yunosov;, Murad; Abrams;, Kraig; Hwang;, Billanna; Castilla-Llorente;, Cristina; Chen;, Peter; Farivar;, Alexander S.; Georges;, George E.; Hackman;, Robert C.; Lamm;, Wayne J.E.; Lesnikova;, Marina; Ochs;, Hans D.; Randolph-Habecker;, Julie; Ziegler;, Stephen F.; Storb;, Rainer; Storer;, Barry; Madtes;, David K.; Glenny;, Robb; Mulligan, Michael S.

2010-01-01

Long-term survival after lung transplantation is limited by acute and chronic graft rejection. Induction of immune tolerance by first establishing mixed hematopoietic chimerism (MC) is a promising strategy to improve outcomes. In a preclinical canine model, stable MC was established in recipients after reduced-intensity conditioning and hematopoietic cell transplantation from a DLA-identical donor. Delayed lung transplantation was performed from the stem cell donor without pharmacological immunosuppression. Lung graft survival without loss of function was prolonged in chimeric (n=5) vs. nonchimeric (n=7) recipients (p≤0.05, Fisher’s test). There were histological changes consistent with low grade rejection in 3/5 of the lung grafts in chimeric recipients at ≥1 year. Chimeric recipients after lung transplantation had a normal immune response to a T-dependent antigen. Compared to normal dogs, there were significant increases of CD4+INFγ+, CD4+IL-4+ and CD8+ INFγ+ T-cell subsets in the blood (p <0.0001 for each of the 3 T-cell subsets). Markers for regulatory T-cell subsets including foxP3, IL10 and TGFβ were also increased in CD3+ T cells from the blood and peripheral tissues of chimeric recipients after lung transplantation. Establishing MC is immunomodulatory and observed changes were consistent with activation of both the effector and regulatory immune response. PMID:19422333

Human Stem Cells Can Differentiate in Post-implantation Mouse Embryos.

PubMed

Tam, Patrick P L

2016-01-07

The potency of human pluripotent stem cells (hPSCs) to differentiate into germ layer derivatives is conventionally assessed by teratoma induction and in vitro differentiation. In this issue of Cell Stem Cell, Mascetti and Pedersen (2016) demonstrate that the human-mouse post-implantation chimera offers an efficient avenue to test the germ layer differentiation potential of hPSCs in mouse embryos ex vivo. Copyright © 2016 Elsevier Inc. All rights reserved.

Induction of tolerance and prolongation of islet allograft survival by syngeneic hematopoietic stem cell transplantation in mice.

PubMed

Yang, Shi-feng; Xue, Wu-jun; Lu, Wan-hong; Xie, Li-yi; Yin, Ai-ping; Zheng, Jin; Sun, Ji-ping; Li, Yang

2015-10-01

Syngeneic or autologous hematopoietic stem cells transplantation (HSCT) has been proposed to treat autoimmune diseases because of its immunosuppressive and immunomodulatory effects, which can also contribute to posttransplant antirejection therapy. In this study, we explored the tolerogenic effect of syngeneic HSCT on prolonging islet allograft survival. C57BL/6 mice received syngeneic HSCT plus preconditioning with sublethal irradiation. Then islets of BALB/c mice were transplanted into the renal subcapsular of C57BL/6 mice after chemically induced into diabetes. HSCT mice exhibited improved islet allograft survival and increased serum insulin compared to control mice. Islet allografts of HSCT mice displayed lower level lymphocyte infiltration and stronger insulin staining than control mice. T cells of HSCT mice proliferated poorly in response to allogeneic splenocytes compared to control mice. Mice appeared reversed interferon-γ (IFN-γ)/interleukin-4 (IL-4) ratio to a Th2 immune deviation after syngeneic HSCT. The percentage of CD8(+) T cells was lower, while percentage of CD4(+)CD25(+)Foxp3(+) T regulatory cells (Tregs) was higher in HSCT mice than control mice. HSCT mice showed higher percentage of CTLA-4(+) T cells and expression of CTLA-4 mRNA than control mice. Targeting of CTLA-4 by intraperitoneal injection of anti-CTLA-4 mAb abrogated the effect of syngeneic HSCT on prolonging islet allograft survival, inhibiting activity of T cells in response to alloantigen, promoting Th1 to Th2 immune deviation and up regulating CD4(+)CD25(+)Foxp3(+) Tregs. Syngeneic HSCT plus preconditioning of sublethal irradiation induces tolerance and improves islet allograft survival in fully mismatched mice model. Th1 to Th2 immune deviation, increased CD4(+)CD25(+)Foxp3(+) Tregs and up-regulation of CTLA-4 maybe contribute to the tolerogenic effect induced by syngeneic HSCT. Copyright © 2015 Elsevier B.V. All rights reserved.

Simple Signaling Molecules for Inductive Bone Regenerative Engineering

PubMed Central

Nelson, Stephen J.; Deng, Meng; Sethuraman, Swaminathan; Doty, Stephen B.; Lo, Kevin W. H.; Khan, Yusuf M.; Laurencin, Cato T.

2014-01-01

With greater than 500,000 orthopaedic procedures performed in the United States each year requiring a bone graft, the development of novel graft materials is necessary. We report that some porous polymer/ceramic composite scaffolds possess intrinsic osteoinductivity as shown through their capacity to induce in vivo host osteoid mineralization and in vitro stem cell osteogenesis making them attractive synthetic bone graft substitutes. It was discovered that certain low crystallinity ceramics partially dissociate into simple signaling molecules (i.e., calcium and phosphate ions) that induce stem cells to endogenously produce their own osteoinductive proteins. Review of the literature has uncovered a variety of simple signaling molecules (i.e., gases, ions, and redox reagents) capable of inducing other desirable stem cell differentiation through endogenous growth factor production. Inductive simple signaling molecules, which we have termed inducerons, represent a paradigm shift in the field of regenerative engineering where they can be utilized in place of recombinant protein growth factors. PMID:25019622

DR5 as a reporter system to study auxin response in Populus.

PubMed

Chen, Yiru; Yordanov, Yordan S; Ma, Cathleen; Strauss, Steven; Busov, Victor B

2013-03-01

KEY MESSAGE : Auxin responsive promoter DR5 reporter system is functional in Populus to monitor auxin response in tissues including leaves, roots, and stems. We described the behavior of the DR5::GUS reporter system in stably transformed Populus plants. We found several similarities with Arabidopsis, including sensitivity to native and synthetic auxins, rapid induction after treatment in a variety of tissues, and maximal responses in root tissues. There were also several important differences from Arabidopsis, including slower time to maximum response and lower induction amplitude. Young leaves and stem sections below the apex showed much higher DR5 activity than did older leaves and stems undergoing secondary growth. DR5 activity was highest in cortex, suggesting high levels of auxin concentration and/or sensitivity in this tissue. Our study shows that the DR5 reporter system is a sensitive and facile system for monitoring auxin responses and distribution at cellular resolution in poplar.

Activation of p38 MAPK participates in brain ischemic tolerance induced by limb ischemic preconditioning by up-regulating HSP 70.

PubMed

Sun, Xiao-Cai; Xian, Xiao-Hui; Li, Wen-Bin; Li, Li; Yan, Cai-Zhen; Li, Qing-Jun; Zhang, Min

2010-08-01

This study investigates whether activation of p38 MAPK by the up-regulation of HSP 70 participates in the induction of brain ischemic tolerance by limb ischemic preconditioning (LIP). Western blot and immunohistochemical assays indicated that p38 MAPK activation occurred earlier than HSP 70 induction in the CA1 region of the hippocampus after LIP. P-p38 MAPK expression was up-regulated at 6h and reached its peak 12h after LIP, while HSP 70 expression was not significantly increased until 1 day and peaked 2 days after LIP. Neuropathological evaluation by thionin staining showed that quercetin (4 ml/kg, 50mg/kg, intraperitoneal injection), an inhibitor of HSP 70, blocked the protective effect of LIP against delayed neuronal death that is normally induced by lethal brain ischemic insult, indicating that HSP 70 participates in the induction of brain ischemic tolerance by LIP. Furthermore, SB 203580, an inhibitor of HSP 70, inhibited HSP 70 activation in the CA1 region of the hippocampus induced by LIP either with or without the presence of subsequent brain ischemic insult. Based on the above results, it can be concluded that activation of p38 MAPK participates in the brain ischemic tolerance induced by LIP at least partly by the up-regulation of HSP 70 expression. (c) 2010 Elsevier Inc. All rights reserved.

[A pharmacological study of chlorphenesin carbamate. Tolerance to chlorphenesin carbamate (author's transl)].

PubMed

Sasajima, M; Aihara, H; Akiyama, F; Tsuchida, K; Otomo, S

1977-04-01

Tolerance to chlorphenesin carbamate (CPC) was investigated from the viewpoints of action of CPC, serum free CPC concentration, the activity of UDP-glucuronyltransferase and the content of cytochrome P-450. CPC was administered once daily for 7 or 14 days. In mice, the hypnotic action of hexobarbital injected 24 hours after the last administration of CPC and the motor incoordinating action of CPC significantly decreased on the 7th day, but slightly recovered on the 14th day. Serum free CPC concentration also decreased on the 7th day, but recovered on the 14th day. A significant relationship between the motor incoordinating action of CPC and serum free CPC concentration was observed. Therefore, the recovery of CPC effect on the 14th day was considered to be due to the recovery from the induction of drug-metabolizing enzymes. On the other hand, in rats, the weekly alteration of the motor incoordinating action of CPC was similar to that observed in mice. Serum free CPC concentration on the 7th and 14th days was lower than that on the 1st day, and enzyme induction was observed during CPC administration. Notwithstanding the low level of serum free CPC concentration, the recovery of CPC effect was observed on the 14th day and such was considered to be due to habituation to the rotarod. In mice and rats, it was demonstrated that the intensity of CPC effect was dependent on serum free CPC concentration to the extent that enzyme induction played an important role in the development of tolerance. From these results, the tolerance to CPC is attributed to induction of drug-metabolizing enzymes in liver microsomes.

Adipose-derived mesenchymal stem cells and regenerative medicine.

PubMed

Konno, Masamitsu; Hamabe, Atsushi; Hasegawa, Shinichiro; Ogawa, Hisataka; Fukusumi, Takahito; Nishikawa, Shimpei; Ohta, Katsuya; Kano, Yoshihiro; Ozaki, Miyuki; Noguchi, Yuko; Sakai, Daisuke; Kudoh, Toshihiro; Kawamoto, Koichi; Eguchi, Hidetoshi; Satoh, Taroh; Tanemura, Masahiro; Nagano, Hiroaki; Doki, Yuichiro; Mori, Masaki; Ishii, Hideshi

2013-04-01

Adipose tissue-derived mesenchymal stem cells (ADSCs) are multipotent and can differentiate into various cell types, including osteocytes, adipocytes, neural cells, vascular endothelial cells, cardiomyocytes, pancreatic β-cells, and hepatocytes. Compared with the extraction of other stem cells such as bone marrow-derived mesenchymal stem cells (BMSCs), that of ADSCs requires minimally invasive techniques. In the field of regenerative medicine, the use of autologous cells is preferable to embryonic stem cells or induced pluripotent stem cells. Therefore, ADSCs are a useful resource for drug screening and regenerative medicine. Here we present the methods and mechanisms underlying the induction of multilineage cells from ADSCs. © 2013 The Authors Development, Growth & Differentiation © 2013 Japanese Society of Developmental Biologists.

Becoming less tolerant with age: sugar maple, shade, and ontogeny.

PubMed

Sendall, Kerrie M; Lusk, Christopher H; Reich, Peter B

2015-12-01

Although shade tolerance is often assumed to be a fixed trait, recent work suggests ontogenetic changes in the light requirements of tree species. We determined the influence of gas exchange, biomass distribution, and self-shading on ontogenetic variation in the instantaneous aboveground carbon balance of Acer saccharum. We quantified the aboveground biomass distributions of 18 juveniles varying in height and growing in low light in a temperate forest understory in Minnesota, USA. Gas exchange rates of leaf and stem tissues were measured, and the crown architecture of each individual was quantified. The YPLANT program was used to estimate the self-shaded fraction of each crown and to model net leaf-level carbon gain. Leaf respiration and photosynthesis per gram of leaf tissue increased with plant size. In contrast, stem respiration rates per gram of stem tissue declined, reflecting a shift in the distribution of stem diameter sizes from smaller (with higher respiration) to larger diameter classes. However, these trends were outweighed by ontogenetic increases in self-shading (which reduces the net photosynthesis realized) and stem mass fraction (which increases the proportion of purely respiratory tissue) in terms of influence on net carbon exchange. As a result, net carbon gain per gram of aboveground plant tissue declined with increasing plant size, and the instantaneous aboveground light compensation point increased. When estimates of root respiration were included to model whole-plant carbon gain and light compensation points, relationships with plant size were even more pronounced. Our findings show how an interplay of gas exchange, self-shading, and biomass distribution shapes ontogenetic changes in shade tolerance.

Increased Susceptibility to Allergic Asthma with the Impairment of Respiratory Tolerance Caused by Psychological Stress.

PubMed

Kawano, Tasuku; Ouchi, Ryusuke; Ishigaki, Takahiro; Masuda, Chiaki; Miyasaka, Tomomitsu; Ohkawara, Yuichi; Ohta, Nobuo; Takayanagi, Motoaki; Takahashi, Tomoko; Ohno, Isao

2018-06-06

Bronchial asthma is characterized by type 2 T helper (Th2) cell inflammation, essentially due to a breakdown of immune tolerance to harmless environmental allergens. Etiologically, experiences of psychological stress can be associated with a heightened prevalence of asthma. However, the mechanisms underlying stress-related asthma development are unclear. In this study, we examined whether psychological stress increases susceptibility to allergic asthma by downregulating immune tolerance. Female BALB/c mice were sensitized with ovalbumin/alum, followed by ovalbumin inhalation. Ovalbumin inhalation induced immune tolerance before sensitization occurred. Some mice were exposed to restraint stress during tolerance induction or sensitization. Asthma development was evaluated by airway responsiveness, inflammation, cytokine expression, and IgE synthesis. Sensitization was evaluated by measuring proliferation and cytokine production by splenocytes. The effects of stress exposure on the numbers and functions of dendritic cells and regulatory T (Treg) cells in bronchial lymph nodes and spleens were evaluated. To investigate the role of endogenous glucocorticoid in inhibiting immune tolerance after stress exposure, we examined the effects of (i) a glucocorticoid-receptor antagonist administered prior to stress exposure, and (ii) exogenous gluco-corticoid (instead of stress exposure). Asthmatic responses and Th2-biased sensitization, which were suppressed in tolerized mice, re-emerged in tolerized mice stressed during tolerance induction in association with decreased tolerogenic dendritic and Treg cell numbers. The effects of stress exposure on tolerized mice were abolished by administering a glucocorticoid-receptor antagonist and reproduced by administering exogenous glucocorticoid without stress. Our findings suggested that psychological stress can potentially increase allergic asthma susceptibility by inhibiting immune tolerance. © 2018 S. Karger AG, Basel.

Markers of tolerance development to food allergens.

PubMed

Ponce, M; Diesner, S C; Szépfalusi, Z; Eiwegger, T

2016-10-01

IgE-mediated reactions to food allergens are the most common cause of anaphylaxis in childhood. Although allergies to cow's milk, egg, or soy proteins, in contrast to peanut and tree nut allergens, resolve within the first 6 years of life in up to 60% due to natural tolerance development, this process is not well understood. At present, there is no cure or treatment for food allergy that would result in an induction of tolerance to the symptom-eliciting food. Avoidance, providing an emergency plan and education, is the standard of treatment. Oral immunotherapeutic approaches have been proven reasonable efficacy; however, they are associated with high rates of side-effects and low numbers of patients achieving tolerance. Nevertheless, mechanisms that take place during oral immunotherapy may help to understand tolerance development. On the basis of these therapeutic interventions, events like loss of basophil activation and induction of regulatory lymphocyte subsets and of blocking antibodies have been described. Their functional importance at a clinical level, however, remains to be investigated in detail. Consequently, there is eminent need to understand the process of tolerance development to food allergens and define biomarkers to develop and monitor new treatment strategies for food allergy. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Dendritic cells in oral tolerance in the gut.

PubMed

Rescigno, Maria

2011-09-01

Oral tolerance is a process that allows generation of systemic unresponsiveness to food antigens. Hence if the same antigen is introduced systemically even under immunogenic conditions it does not induce immune responsiveness. Dendritic cells (DCs) have been identified as essential players in this process. DCs in the gut are located in a strategic position as they can interact directly with luminal antigens or indirectly after their transcytosis across epithelial cells. DCs can then migrate to associated lymphoid tissues to induce tolerance. Antigen presenting cells in the gut are specialized in function and have divided their labour so that there are cells capable to migrate to the draining mesenteric lymph node for induction of T regulatory cells, while other subsets are resident and are required to enforce tolerance locally in the gut after food antigen exposure. In this review, I shall summarize the characteristics of antigen presenting cells in the gut and their involvement in oral tolerance induction. In addition, I will also emphasize that tolerance to food allergens may be contributed by plasmacytoid DCs in the liver that participate to the elimination or anergy of allergen-specific CD8 T cells. Hence specialized functions are associated to different subsets of antigen presenting cells and different organs. © 2011 Blackwell Publishing Ltd.

Induction of abiotic stress tolerance in plants by endophytic microbes.

PubMed

Lata, R; Chowdhury, S; Gond, S K; White, J F

2018-04-01

Endophytes are micro-organisms including bacteria and fungi that survive within healthy plant tissues and promote plant growth under stress. This review focuses on the potential of endophytic microbes that induce abiotic stress tolerance in plants. How endophytes promote plant growth under stressful conditions, like drought and heat, high salinity and poor nutrient availability will be discussed. The molecular mechanisms for increasing stress tolerance in plants by endophytes include induction of plant stress genes as well as biomolecules like reactive oxygen species scavengers. This review may help in the development of biotechnological applications of endophytic microbes in plant growth promotion and crop improvement under abiotic stress conditions. Increasing human populations demand more crop yield for food security while crop production is adversely affected by abiotic stresses like drought, salinity and high temperature. Development of stress tolerance in plants is a strategy to cope with the negative effects of adverse environmental conditions. Endophytes are well recognized for plant growth promotion and production of natural compounds. The property of endophytes to induce stress tolerance in plants can be applied to increase crop yields. With this review, we intend to promote application of endophytes in biotechnology and genetic engineering for the development of stress-tolerant plants. © 2018 The Society for Applied Microbiology.

Zeatin and Thidiazuron Induced Embryogenic Calli From In Vitro Leaf and Stem of Jojoba (Simmondsia chinensis).

PubMed

El-Ashry, Amal Abd El-Latif; Gabr, Ahmed Mohamed Magdy; Bekheet, Shawky Abd El-Hamid

2017-01-01

Jojoba is a promising industrial plant, which recommended with pharmaceutical benefits. The present study was conducted to stimulate embryogenic calli formation from jojoba using zeatin and thidiazuron (TDZ), as well as determination of the antioxidant activity of proliferated calli. For callus induction, leaf and stem explants derived from in vitro grown shootlets, were cultured on Murashige and Skoog (MS) medium with different combinations of 0.5 mg L-1 benzyl adenine (BA) or kinetin with 2,4-Dichlorophenoxyacetic acid (2,4-D), Naphthalene acetic acid (NAA) and picloram at 0.5 or 1mg L-1. To stimulate embryogenic calli, friable callus were transferred to woody plant medium (WPM) supplemented with different concentrations of zeatin or TDZ. Antioxidant activity of different treatments was determined using hexane or petroleum ether extraction. Data was analyzed as mean±standard deviation (SD). The MS medium supplemented with 0.5 mg L-1 BA+0.5 or 1 mg L-1 picloram was the best treatment to obtain friable calli from both explants types. WPM medium supplemented with 2 mg L-1 zeatin gave the highest percentage of embryogenic calli derived from leaf explants. While the highest percentage of embryogenic calli derived from stem explants was registered using 1 or 4 mg L-1 TDZ containing medium. Embryogenic calli originated from leaves explants on 1.5 mg L-1 zeatin showed promising activity of antioxidant with hexane extraction. However, embryogenic calli originated from stem explants on 1 mg L-1 TDZ showed the highest antioxidant activity with petroleum ether extraction. TDZ has promising effect on embryogenic callus induction from stem explants. While, zeatin has promising effect on embryogenic callus induction from leaf explants.

Functional high-resolution time-course expression analysis of human embryonic stem cells undergoing cardiac induction.

PubMed

Piccini, Ilaria; Araúzo-Bravo, Marcos; Seebohm, Guiscard; Greber, Boris

2016-12-01

Cardiac induction of human embryonic stem cells (hESCs) is a process bearing increasing medical relevance, yet it is poorly understood from a developmental biology perspective. Anticipated technological progress in deriving stably expandable cardiac precursor cells or in advancing cardiac subtype specification protocols will likely require deeper insights into this fascinating system. Recent improvements in controlling hESC differentiation now enable a near-homogeneous induction of the cardiac lineage. This is based on an optimized initial stimulation of mesoderm-inducing signaling pathways such as Activin and/or FGF, BMP, and WNT, followed by WNT inhibition as a secondary requirement. Here, we describe a comprehensive data set based on varying hESC differentiation conditions in a systematic manner and recording high-resolution differentiation time-courses analyzed by genome-wide expression profiling (GEO accession number GSE67154). As a baseline, hESCs were differentiated into cardiomyocytes under optimal conditions. Moreover, in additional time-series, individual signaling factors were withdrawn from the initial stimulation cocktail to reveal their specific roles via comparison to the standard condition. Hence, this data set presents a rich resource for hypothesis generation in studying human cardiac induction, as we reveal numbers of known as well as uncharacterized genes prominently marking distinct intermediate stages in the process. These data will also be useful for identifying putative cardiac master regulators in the human system as well as for characterizing expandable cardiac stem cells.

Pancreatic differentiation of Pdx1-GFP reporter mouse induced pluripotent stem cells.

PubMed

Porciuncula, Angelo; Kumar, Anujith; Rodriguez, Saray; Atari, Maher; Araña, Miriam; Martin, Franz; Soria, Bernat; Prosper, Felipe; Verfaillie, Catherine; Barajas, Miguel

2016-12-01

Efficient induction of defined lineages in pluripotent stem cells constitutes the determinant step for the generation of therapeutically relevant replacement cells to potentially treat a wide range of diseases, including diabetes. Pancreatic differentiation has remained an important challenge in large part because of the need to differentiate uncommitted pluripotent stem cells into highly specialized hormone-secreting cells, which has been shown to require a developmentally informed step-by-step induction procedure. Here, in the framework of using induced pluripotent stem cells (iPSCs) to generate pancreatic cells for pancreatic diseases, we have generated and characterized iPSCs from Pdx1-GFP transgenic mice. The use of a GFP reporter knocked into the endogenous Pdx1 promoter allowed us to monitor pancreatic induction based on the expression of Pdx1, a pancreatic master transcription factor, and to isolate a pure Pdx1-GFP + population for downstream applications. Differentiated cultures timely expressed markers specific to each stage and end-stage progenies acquired a rather immature beta-cell phenotype, characterized by polyhormonal expression even among cells highly expressing the Pdx1-GFP reporter. Our findings highlight the utility of employing a fluorescent protein reporter under the control of a master developmental gene in order to devise novel differentiation protocols for relevant cell types for degenerative diseases such as pancreatic beta cells for diabetes. Copyright © 2016 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

Intra-osseous injection of donor mesenchymal stem cell (MSC) into the bone marrow in living donor kidney transplantation; a pilot study.

PubMed

Lee, Hyunah; Park, Jae Berm; Lee, Sanghoon; Baek, Soyoung; Kim, HyunSoo; Kim, Sung Joo

2013-04-11

Mesenchymal stem cells (MSCs) are multi-potent non-hematopoietic progenitor cells possessing an immune-regulatory function, with suppression of proliferation of activated lymphocytes. In this study, adult living donor kidney transplantation (LDKT) recipients were given MSCs derived from the donor bone marrow to evaluate the safety and the feasibility of immunological changes related to the intra-osseous injection of MSC into the bone marrow. MSCs were derived from negative HLA cross-match donors. Donor bone marrow was harvested 5 weeks prior to KT. At the time of transplantation, 1 x 106 cell/kg of donor MSC was directly injected into the bone marrow of the recipient's right iliac bone. Patients' clinical outcomes, presence of mixed chimerism by short tandem repeat polymerase chain reaction, analysis of plasma FoxP3 mRNA and cytokine level, and mixed lymphocyte reaction (MLR) were performed. Seven patients enrolled in this study and received donor MSC injections simultaneously with LDKT. The median age of recipients was 36 years (32 ~ 48). The number of HLA mismatches was 3 or less in 5 and more than 3 in 2. No local complications or adverse events such as hypersensitivity occurred during or after the injection of donor MSC. There was no graft failure, but the biopsy-proven acute rejections were observed in 3 recipients during the follow-up period controlled well with steroid pulse therapy (SPT). The last serum creatinine was a median of 1.23 mg/dL (0.83 ~ 2.07). Mixed chimerism was not detected in the peripheral blood of the recipients at 1 and 8 week of post-transplantation. Donor-specific lymphocyte or T cell proliferation and Treg priming responses were observed in some patients. Plasma level of IL-10, a known mediator of MSC-induced immune suppression, increased in the patients with Treg induction. Donor MSC injection into the iliac bone at the time of KT was feasible and safe. A possible correlation was observed between the induction of inhibitory immune responses and the clinical outcome in the MSC-kidney transplanted patients. Further research will be performed to evaluate the efficacy of MSC injection for the induction of mixed chimerism and subsequent immune tolerance in KT.

Generation of functional hepatocyte-like cells from human deciduous periodontal ligament stem cells.

PubMed

Vasanthan, Punitha; Jayaraman, Pukana; Kunasekaran, Wijenthiran; Lawrence, Anthony; Gnanasegaran, Nareshwaran; Govindasamy, Vijayendran; Musa, Sabri; Kasim, Noor Hayaty Abu

2016-08-01

Human deciduous periodontal ligament stem cells have been introduced for as an easily accessible source of stem cells from dental origin. Although recent studies have revealed the ability of these stem cells in multipotential attribute, their efficiency of hepatic lineage differentiation has not been addressed so far. The aim of this study is to investigate hepatic lineage fate competence of periodontal ligament stem cells through direct media induction. Differentiation of periodontal ligament stem cells into hepatocyte-like cells was conducted by the exposure of two phase media induction. First phase was performed in the presence of hepatocyte growth factors to induce a definitive endoderm formation. In the subsequent phase, the cells were treated with oncostatin M and dexamethosone followed by insulin and transferrin to generate hepatocyte-like cells. Hepatic-related characters of the generated hepatocyte-like cells were determined at both mRNA and protein level followed by functional assays. Foremost changes observed in the generation of hepatocyte-like cells were the morphological features in which these cells were transformed from fibroblastic shape to polygonal shape. Temporal expression of hepatic markers ranging from early endodermal up to late markers were detected in the hepatocyte-like cells. Crucial hepatic markers such as glycogen storage, albumin, and urea secretion were also shown. These findings exhibited the ability of periodontal ligament stem cells of dental origin to be directed into hepatic lineage fate. These cells can be regarded as an alternative autologous source in the usage of stem cell-based treatment for liver diseases.

Generation of functional hepatocyte-like cells from human deciduous periodontal ligament stem cells

NASA Astrophysics Data System (ADS)

Vasanthan, Punitha; Jayaraman, Pukana; Kunasekaran, Wijenthiran; Lawrence, Anthony; Gnanasegaran, Nareshwaran; Govindasamy, Vijayendran; Musa, Sabri; Kasim, Noor Hayaty Abu

2016-08-01

Human deciduous periodontal ligament stem cells have been introduced for as an easily accessible source of stem cells from dental origin. Although recent studies have revealed the ability of these stem cells in multipotential attribute, their efficiency of hepatic lineage differentiation has not been addressed so far. The aim of this study is to investigate hepatic lineage fate competence of periodontal ligament stem cells through direct media induction. Differentiation of periodontal ligament stem cells into hepatocyte-like cells was conducted by the exposure of two phase media induction. First phase was performed in the presence of hepatocyte growth factors to induce a definitive endoderm formation. In the subsequent phase, the cells were treated with oncostatin M and dexamethosone followed by insulin and transferrin to generate hepatocyte-like cells. Hepatic-related characters of the generated hepatocyte-like cells were determined at both mRNA and protein level followed by functional assays. Foremost changes observed in the generation of hepatocyte-like cells were the morphological features in which these cells were transformed from fibroblastic shape to polygonal shape. Temporal expression of hepatic markers ranging from early endodermal up to late markers were detected in the hepatocyte-like cells. Crucial hepatic markers such as glycogen storage, albumin, and urea secretion were also shown. These findings exhibited the ability of periodontal ligament stem cells of dental origin to be directed into hepatic lineage fate. These cells can be regarded as an alternative autologous source in the usage of stem cell-based treatment for liver diseases.

Women’s G Tolerance

DTIC Science & Technology

1986-08-01

for the groups matched by age (70 pairs), weight sickness, uncomfortable feelings of distension in arms (26 pairs), and act~vity status (84 pairs...mass-spring-damper) s ,stem Straining G tolerance, being dpendent on skeletal having a resonant frequency above about I Hz. As muscular strength and...of the women’s G tolerance stud\\ scclic variations in muscular strength and endurance. was below 0.1 Hz (11), the production of any significant

NIR calibration of soluble stem carbohydrates for predicting drought tolerance in spring wheat

USDA-ARS?s Scientific Manuscript database

Soluble stem carbohydrates are a component of drought response in wheat (Triticum aestivum L.) and other grasses. Near-infrared spectroscopy (NIR) can rapidly assay for soluble carbohydrates indirectly, but this requires a statistical model for calibration. The objectives of this study were: (i) to ...

Arsenate tolerance mechanism of Oenothera odorata from a mine population involves the induction of phytochelatins in roots.

PubMed

Kim, Dae-Yeon; Park, Hyun; Lee, Sang-Hwan; Koo, Namin; Kim, Jeong-Gyu

2009-04-01

We investigated the arsenate tolerance mechanisms of Oenothera odorata by comparing two populations [i.e., one population from the mine site (MP) and the other population from an uncontaminated site (UP)] via the exposure of hydroponic solution containing arsenate (i.e., 0-50 microM). The MP plants were significantly more tolerant to arsenate than UP plants. The UP plants accumulated more As in their shoots and roots than did the MP plants. The UP plants translocated up to 21 microg g(-1) of As into shoots, whereas MP plants translocated less As (up to 4.5 microg g(-1)) to shoots over all treatments. The results of lipid peroxidation indicated that MP plants were less damaged by oxidative stress than were UP plants. Phytochelatin (PC) content correlated linearly with root As concentration in the MP (i.e., [PCs](root)=1.69x[As](root), r(2)=0.945) and UP (i.e., [PCs](root)=0.89x[As](root), r(2)=0.979) plants. This relationship means that increased PC to As ratio may be associated with increased tolerance. Our results suggest that PC induction in roots plays a critical role in As tolerance of O. odorata.

Induction of tolerance to poison ivy urushiol in the guinea pig by epicutaneous application of the structural analog 5-methyl-3-n-pentadecylcatechol.

PubMed

Stampf, J L; Benezra, C; Byers, V; Castagnoli, N

1986-05-01

Previous studies have established that epicutaneous application of 5-methyl-3-n-pentadecylcatechol (5-Me-PDC), a synthetic analog of a poison ivy urushiol component, leads to immune tolerance to 3-n-pentadecylcatechol (PDC) in mice. The induction of tolerance by 5-Me-PDC may be mediated by a protein conjugate formed via selective reaction of thiol nucleophiles present on the carrier macromolecule with the corresponding o-quinone derived from the parent catechol. In order to examine further the tolerogenic properties of 5-Me-PDC, we have extended our studies to the guinea pig, the generally accepted experimental species for the study of contact allergy. The results have established that specific immune tolerance to poison ivy urushiol is induced following 2 epicutaneous applications of the PDC analog. Furthermore, we were able to show that the treated animals remained tolerant for at least 6 weeks, a period of time comparable to that observed following the intravenous administration of the O,O-bis-acetyl derivative of PDC. The data point to the possibility of developing a therapeutically effective topical tolerogen for poison ivy contact dermatitis.

Role of abscisic acid in strigolactone-induced salt stress tolerance in arbuscular mycorrhizal Sesbania cannabina seedlings.

PubMed

Ren, Cheng-Gang; Kong, Cun-Cui; Xie, Zhi-Hong

2018-05-03

Strigolactones (SLs) are considered to be a novel class of phytohormone involved in plant defense responses. Currently, their relationships with other plant hormones, such as abscisic acid (ABA), during responses to salinity stress are largely unknown. In this study, the relationship between SL and ABA during the induction of H 2 O 2 - mediated tolerance to salt stress were studied in arbuscular mycorrhizal (AM) Sesbania cannabina seedlings. The SL levels increased after ABA treatments and decreased when ABA biosynthesis was inhibited in AM plants. Additionally, the expression levels of SL-biosynthesis genes in AM plants increased following treatments with exogenous ABA and H 2 O 2 . Furthermore, ABA-induced SL production was blocked by a pre-treatment with dimethylthiourea, which scavenges H 2 O 2 . In contrast, ABA production was unaffected by dimethylthiourea. Abscisic acid induced only partial and transient increases in the salt tolerance of TIS108 (a SL synthesis inhibitor) treated AM plants, whereas SL induced considerable and prolonged increases in salt tolerance after a pre-treatment with tungstate. These results strongly suggest that ABA is regulating the induction of salt tolerance by SL in AM S. cannabina seedlings.

Induction of lactation in the intended mother of a surrogate pregnancy: case report.

PubMed

Biervliet, F P; Maguiness, S D; Hay, D M; Killick, S R; Atkin, S L

2001-03-01

A case of a successful induction of lactation in a commissioning mother of a surrogate pregnancy is reported. Induction of lactation was achieved with oral metoclopramide which was well tolerated. Alternative methods to induce lactation are reviewed. The advantages of breast-feeding and the relative ease with which lactation can be induced after a surrogate pregnancy would suggest that this could be offered to all commissioning mothers.

Secretome of Differentiated PC12 Cells Enhances Neuronal Differentiation in Human Mesenchymal Stem Cells Via NGF-Like Mechanism.

PubMed

Srivastava, A; Singh, S; Pandey, A; Kumar, D; Rajpurohit, C S; Khanna, V K; Pant, A B

2018-03-12

The secretome-mediated responses over cellular physiology are well documented. Stem cells have been ruling the field of secretomics and its role in regenerative medicine since the past few years. However, the mechanistic aspects of secretome-mediated responses and the role of other cells in this area remain somewhat elusive. Here, we investigate the effects of secretome-enriched conditioned medium (CM) of neuronally differentiated PC12 cells on the neuronal differentiation of human mesenchymal stem cells (hMSCs). The exposure to CM at a ratio of 1:1 (CM: conditioned medium of PC12 cells) led to neuronal induction in hMSCs. This neuronal induction was compared with a parallel group of cells exposed to nerve growth factor (NGF). There was a marked increase in neurite length and expression of neuronal markers (β-III tubulin, neurofilament-M (NF-M), synaptophysin, NeuN in exposed hMSCs). Experimental group co-exposed to NGF and CM showed an additive response via MAPK signaling and directed the cells particularly towards cholinergic lineage. The ability of CM to enhance the neuronal properties of stem cells could aid in their rapid differentiation into neuronal subtypes in case of stem cell transplantation for neuronal injuries, thus broadening the scope of non-stem cell-based applications in the area of secretomics.

A mechanistic framework for noncell autonomous stem cell induction in Arabidopsis.

PubMed

Daum, Gabor; Medzihradszky, Anna; Suzaki, Takuya; Lohmann, Jan U

2014-10-07

Cell-cell communication is essential for multicellular development and, consequently, evolution has brought about an array of distinct mechanisms serving this purpose. Consistently, induction and maintenance of stem cell fate by noncell autonomous signals is a feature shared by many organisms and may depend on secreted factors, direct cell-cell contact, matrix interactions, or a combination of these mechanisms. Although many basic cellular processes are well conserved between animals and plants, cell-to-cell signaling is one function where substantial diversity has arisen between the two kingdoms of life. One of the most striking differences is the presence of cytoplasmic bridges, called plasmodesmata, which facilitate the exchange of molecules between neighboring plant cells and provide a unique route for cell-cell communication in the plant lineage. Here, we provide evidence that the stem cell inducing transcription factor WUSCHEL (WUS), expressed in the niche, moves to the stem cells via plasmodesmata in a highly regulated fashion and that this movement is required for WUS function and, thus, stem cell activity in Arabidopsis thaliana. We show that cell context-independent mobility is encoded in the WUS protein sequence and mediated by multiple domains. Finally, we demonstrate that parts of the protein that restrict movement are required for WUS homodimerization, suggesting that formation of WUS dimers might contribute to the regulation of apical stem cell activity.

Cell-Based Therapies in Vascularized Composite Allotransplantation.

PubMed

Vyas, Krishna S; Mohan, Anita T; Morrison, Shane D; Tran, Duy C; Mardini, Samir

2018-06-26

 Dendritic cells (DCs) are bone marrow-derived, professional antigen-presenting cells with tolerogenic function. The ability of DCs to regulate alloantigen-specific T cell responses and to promote tolerance has aligned them ideally for a role in vascularized composite allotransplantation (VCA). In this study, we summarize the current evidence for DC therapies for tolerance induction to alleviate the requirement for chronic immunosuppression.  A comprehensive and structured review of manuscripts published on VCA was performed using the MEDLINE and PubMed databases. All eligible studies published from the year 2000 to 2017 were included in the final results.  Nineteen original preclinical and clinical studies that employed cell therapy for VCA were included in this review. In vivo DC therapy was found to direct the alloimmune response toward either transplant rejection or tolerance in VCA models. While injection of mature DCs rapidly increases T-cell activity in humans and promotes transplant rejection, the injection of immature DCs acts as an immunosuppressant and inhibits T-cell activity. In addition to immature DCs, mesenchymal stem cells were also found to have a positive effect on allotransplantation of solid organs and bone marrow via cytokine expression which decreases the alloreactive effector lymphocytes and increases CD4+/CD25+/FoxP3 Tregs. Despite the promising findings, the efficacy of cell-based therapies varies greatly across studies, partly due to different methods of cell isolation and purification techniques, source, route and timing of administration, and combination immunosuppressive therapy.  Additional research is needed to evaluate the efficacy and safety of DC and other cell-based therapeutic measures in human allotransplant recipients. Future direction will focus on the development of novel methods to reduce immunosuppression and develop more individualized management, as well as the clinical application of basic research in the mechanisms of immunologic tolerance. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

D.b.h./crown diameter relationships in mixed Appalachian hardwood stands

Treesearch

Neil I. Lamson; Neil I. Lamson

1987-01-01

Linear regression formulae for predicting crown diameter as a function of stem diameter are presented for nine species found in 50- to 80-year-old mixed hardwood stands in north-central West Virginia. Generally, crown diameter was closely related to tolerance; more tolerant species had larger crowns.

Differentiation of Mesenchymal Stem Cells Derived from Pancreatic Islets and Bone Marrow into Islet-Like Cell Phenotype

PubMed Central

Zanini, Cristina; Bruno, Stefania; Mandili, Giorgia; Baci, Denisa; Cerutti, Francesco; Cenacchi, Giovanna; Izzi, Leo; Camussi, Giovanni; Forni, Marco

2011-01-01

Background Regarding regenerative medicine for diabetes, accessible sources of Mesenchymal Stem Cells (MSCs) for induction of insular beta cell differentiation may be as important as mastering the differentiation process itself. Methodology/Principal Findings In the present work, stem cells from pancreatic islets (human islet-mesenchymal stem cells, HI-MSCs) and from human bone marrow (bone marrow mesenchymal stem cells, BM-MSCs) were cultured in custom-made serum-free medium, using suitable conditions in order to induce differentiation into Islet-like Cells (ILCs). HI-MSCs and BM-MSCs were positive for the MSC markers CD105, CD73, CD90, CD29. Following this induction, HI-MSC and BM-MSC formed evident islet-like structures in the culture flasks. To investigate functional modifications after induction to ILCs, ultrastructural analysis and immunofluorescence were performed. PDX1 (pancreatic duodenal homeobox gene-1), insulin, C peptide and Glut-2 were detected in HI-ILCs whereas BM-ILCs only expressed Glut-2 and insulin. Insulin was also detected in the culture medium following glucose stimulation, confirming an initial differentiation that resulted in glucose-sensitive endocrine secretion. In order to identify proteins that were modified following differentiation from basal MSC (HI-MSCs and BM-MSCs) to their HI-ILCs and BM-ILCs counterparts, proteomic analysis was performed. Three new proteins (APOA1, ATL2 and SODM) were present in both ILC types, while other detected proteins were verified to be unique to the single individual differentiated cells lines. Hierarchical analysis underscored the limited similarities between HI-MSCs and BM-MSCs after induction of differentiation, and the persistence of relevant differences related to cells of different origin. Conclusions/Significance Proteomic analysis highlighted differences in the MSCs according to site of origin, reflecting spontaneous differentiation and commitment. A more detailed understanding of protein assets may provide insights required to master the differentiation process of HI-MSCs to functional beta cells based only upon culture conditioning. These findings may open new strategies for the clinical use of BM-MSCs in diabetes. PMID:22194812

Therapeutic Effect of Human Adipose Tissue-Derived Mesenchymal Stem Cells in Experimental Corneal Failure Due to Limbal Stem Cell Niche Damage.

PubMed

Galindo, Sara; Herreras, José M; López-Paniagua, Marina; Rey, Esther; de la Mata, Ana; Plata-Cordero, María; Calonge, Margarita; Nieto-Miguel, Teresa

2017-10-01

Limbal stem cells are responsible for the continuous renewal of the corneal epithelium. The destruction or dysfunction of these stem cells or their niche induces limbal stem cell deficiency (LSCD) leading to visual loss, chronic pain, and inflammation of the ocular surface. To restore the ocular surface in cases of bilateral LSCD, an extraocular source of stem cells is needed to avoid dependence on allogeneic limbal stem cells that are difficult to obtain, isolate, and culture. The aim of this work was to test the tolerance and the efficacy of human adipose tissue-derived mesenchymal stem cells (hAT-MSCs) to regenerate the ocular surface in two experimental models of LSCD that closely resemble different severity grades of the human pathology. hAT-MSCs transplanted to the ocular surface of the partial and total LSCD models developed in rabbits were well tolerated, migrated to inflamed tissues, reduced inflammation, and restrained the evolution of corneal neovascularization and corneal opacity. The expression profile of the corneal epithelial cell markers CK3 and E-cadherin, and the limbal epithelial cell markers CK15 and p63 was lost in the LSCD models, but was partially recovered after hAT-MSC transplantation. For the first time, we demonstrated that hAT-MSCs improve corneal and limbal epithelial phenotypes in animal LSCD models. These results support the potential use of hAT-MSCs as a novel treatment of ocular surface failure due to LSCD. hAT-MSCs represent an available, non-immunogenic source of stem cells that may provide therapeutic benefits in addition to reduce health care expenses. Stem Cells 2017;35:2160-2174. © 2017 AlphaMed Press.

The biological effect of prolonged radiation and ways of selecting new anti-radiation drugs effective in this kind of radiation injury

NASA Technical Reports Server (NTRS)

Rogozkin, V. D.; Chertkov, K. S.; Nikolov, I.

1974-01-01

The basic characteristics of prolonged radiation - increased tolerance of radiation injury - are attributed to cellular kinetics; as dose rate is reduced, the population rate is not disturbed, particularly that of stem cells which makes it possible for the organism to tolerate higher radiation loads. It is concluded that this effect makes approved radio protectors, whose effect contains an established cytostatic component, unsuitable for prolonged radiation. It is better to correct the stem pool formation process by either accelerating the proliferation of cells or limiting the effect of stimuli causing cells to lose colony forming properties.

Effects of microgravity modeled by large gradient high magnetic field on the osteogenic initiation of human mesenchymal stem cells.

PubMed

Shi, Dongyan; Meng, Rui; Deng, Wanglong; Ding, Wenchao; Zheng, Qiang; Yuan, Wenji; Liu, Liyue; Zong, Chen; Shang, Peng; Wang, Jinfu

2010-12-01

Microgravity (MG) leads to a decrease in osteogenic potential of human bone marrow-derived mesenchymal stem cells (hMSCs). In the present study, we used large gradient high magnetic field (LGHMF) produced by a superconducting magnet to model MG (LGHMF-MG) and analyzed the effects of LGHMF-MG on survival, cytoskeleton and osteogenic potential of hMSCs. Results showed that the LGHMF-MG treatment for 6 h disrupted the cytoskeleton of hMSCs, and the LGHMF-MG treatment for 24 h led to cell death. LGHMF-MG treatments for 6 h in early stages of osteogenic induction (the pre-treatment before osteogenic induction, the beginning-treatment in the beginning-stage of osteogenic induction and the middle-treatment in the middle-stage of osteogenic induction) resulted in suppression on osteogenesis of hMSCs. The suppression intensity was reduced gradually as the treatment stage of LGHMF-MG was postponed. The LGHMF-MG treatment for 6 h in the ending-stage of osteogenic induction (the ending-treatment) had no obvious effect on osteogenesis of hMSCs. These results indicated that LGHMF-MG should affect the initiation of osteogenesis. Finally, the possible mechanism for the inhibition effect of LGHMF-MG on osteogenesis of hMSCs is discussed.

The evolving roles of memory immune cells in transplantation

PubMed Central

Chen, Wenhao; Ghobrial, Rafik M.; Li, Xian C.

2015-01-01

Memory cells are the products of immune responses but also exert significant impact on subsequent immunity and immune tolerance, thus placing them in a unique position in transplant research. Memory cells are heterogeneous, including not only memory T cells but also memory B cells and innate memory cells. Memory cells are a critical component of protective immunity against invading pathogens, especially in immunosuppressed patients, but they also mediate graft loss and tolerance resistance. Recent studies suggest that some memory cells unexpectedly act as regulatory cells, promoting rather than hindering transplant survival. This functional diversity makes therapeutic targeting of memory cells a challenging task in transplantation. In this article we highlight recent advances in our understanding of memory cells, focusing on diversity of memory cells and mechanisms involved in their induction and functions. We also provide a broad overview on the challenges and opportunities in targeting memory cells in the induction of transplant tolerance. PMID:26102615

Regeneration of Solanum nigrum by somatic embryogenesis, involving frog egg-like body, a novel structure.

PubMed

Xu, Kedong; Chang, Yunxia; Liu, Kun; Wang, Feige; Liu, Zhongyuan; Zhang, Ting; Li, Tong; Zhang, Yi; Zhang, Fuli; Zhang, Ju; Wang, Yan; Niu, Wei; Jia, Shuzhao; Xie, Hengchang; Tan, Guangxuan; Li, Chengwei

2014-01-01

A new protocol was established for the regeneration of Solanum nigrum by frog egg-like bodies (FELBs), which are novel somatic embryogenesis (SE) structures induced from the root, stem, and leaf explants. The root, stem, and leaf explants (93.33%, 85.10%, and 100.00%, respectively) were induced to form special embryonic calli on Murashige and Skoog (MS) medium containing 1.0 mg/L 2,4-dichlorophenoxyacetic acid, under dark condition. Further, special embryonic calli from the root, stem, and leaf explants (86.97%, 83.30%, and 99.47%, respectively) were developed into FELBs. Plantlets of FELBs from the three explants were induced in vitro on MS medium supplemented with 5.0 mg/L 6-benzylaminopurine and 0.1 mg/L gibberellic acid, and 100.00% plantlet induction rates were noted. However, plantlet induction in vivo on MS medium supplemented with 20 mg/L thidiazuron showed rates of 38.63%, 15.63%, and 61.30% for the root, stem, and leaf explants, respectively, which were lower than those of the in vitro culture. Morphological and histological analyses of FELBs at different development stages revealed that they are a novel type of SE structure that developed from the mesophyll (leaf) or cortex (stem and root) cells of S. nigrum.

Methoxyphenyl chalcone sensitizes aggressive epithelial cancer to cisplatin through apoptosis induction and cancer stem cell eradication.

PubMed

Su, Yu-Kai; Huang, Wen-Chien; Lee, Wei-Hwa; Bamodu, Oluwaseun Adebayo; Zucha, Muhammad Ary; Astuti, Indwiani; Suwito, Heri; Yeh, Chi-Tai; Lin, Chien-Min

2017-05-01

Current standard chemotherapy for late stage ovarian cancer is found unsuccessful due to relapse after completing the regimens. After completing platinum-based chemotherapy, 70% of patients develop relapse and resistance. Recent evidence proves ovarian cancer stem cells as the source of resistance. Therefore, treatment strategy to target both cancer stem cells and normal stem cells is essential. In this study, we developed a novel chalcone derivative as novel drug candidate for ovarian cancer treatment. We found that methoxyphenyl chalcone was effective to eliminate ovarian cancer cells when given either as monotherapy or in combination with cisplatin. We found that cell viability of ovarian cancer cells was decreased through apoptosis induction. Dephosphorylation of Bcl2-associated agonist of cell death protein was increased after methoxyphenyl chalcone treatment that led to activation of caspases. Interestingly, this drug also worked as a G2/M checkpoint modulator with alternative ways of DNA damage signal-evoking potential that might work to increase response after cisplatin treatment. In addition, methoxyphenyl chalcone was able to suppress autophagic flux and stemness regulator in ovarian spheroids that decreased their survival. Therefore, combination of methoxyphenyl chalcone and cisplatin showed synergistic effects. Taken together, we believe that our novel compound is a promising novel therapeutic agent for effective clinical treatment of ovarian cancer.

Effects of plant size, temperature, and light intensity on flowering of Phalaenopsis hybrids in Mediterranean greenhouses.

PubMed

Paradiso, Roberta; De Pascale, Stefania

2014-01-01

Mediterranean greenhouses for cultivation of Phalaenopsis orchids reproduce the warm, humid, and shaded environment of tropical underbrush. Heating represents the highest production cost, due to the high thermal requirements and the long unproductive phase of juvenility, in which plants attain the critical size for flowering. Our researches aimed to investigate the effect of plant size, temperature, and light intensity, during the phase of flower induction, on flowering of modern genotypes selected for Mediterranean greenhouses. Three experiments were carried out to compare (i) plant size: reduced size versus size considered optimal for flowering (hybrids "Sogo Yukidian," "Chain Xen Diamond," and "Pinlong"); (ii) temperature: moderate reduction of temperature versus standard thermal regime (hybrid "Premium"); (iii) light intensity: supplemental lighting versus reference light intensity (hybrid "Premium"). The premature exposure of plants to the inductive treatment delayed the beginning of flowering and reduced the flower stem quality, in all the tested hybrids. In "Premium," the lower temperature did not affect flowering earliness and commercial quality of flower stems compared to the standard regime, whereas it promoted stem branching. In the same hybrid, supplemental lighting anticipated flowering and promoted the emission of the second stem and the stem branching, compared to the reference light regime.

NANOG priming before full reprogramming may generate germ cell tumours.

PubMed

Grad, I; Hibaoui, Y; Jaconi, M; Chicha, L; Bergström-Tengzelius, R; Sailani, M R; Pelte, M F; Dahoun, S; Mitsiadis, T A; Töhönen, V; Bouillaguet, S; Antonarakis, S E; Kere, J; Zucchelli, M; Hovatta, O; Feki, A

2011-11-09

Reprogramming somatic cells into a pluripotent state brings patient-tailored, ethical controversy-free cellular therapy closer to reality. However, stem cells and cancer cells share many common characteristics; therefore, it is crucial to be able to discriminate between them. We generated two induced pluripotent stem cell (iPSC) lines, with NANOG pre-transduction followed by OCT3/4, SOX2, and LIN28 overexpression. One of the cell lines, CHiPS W, showed normal pluripotent stem cell characteristics, while the other, CHiPS A, though expressing pluripotency markers, failed to differentiate and gave rise to germ cell-like tumours in vivo. Comparative genomic hybridisation analysis of the generated iPS lines revealed that they were genetically more stable than human embryonic stem cell counterparts. This analysis proved to be predictive for the differentiation potential of analysed cells. Moreover, the CHiPS A line expressed a lower ratio of p53/p21 when compared to CHiPS W. NANOG pre-induction followed by OCT3/4, SOX2, MYC, and KLF4 induction resulted in the same tumour-inducing phenotype. These results underline the importance of a re-examination of the role of NANOG during reprogramming. Moreover, this reprogramming method may provide insights into primordial cell tumour formation and cancer stem cell transformation.

Multicenter phase II study of weekly docetaxel, cisplatin, and S-1 (TPS) induction chemotherapy for locally advanced squamous cell cancer of the head and neck.

PubMed

Bae, Woo Kyun; Hwang, Jun Eul; Shim, Hyun Jeong; Cho, Sang Hee; Lee, Ki Hyeong; Han, Hye Suk; Song, Eun-Kee; Yun, Hwan Jung; Cho, In Sung; Lee, Joon Kyoo; Lim, Sang-Chul; Chung, Woong-Ki; Chung, Ik-Joo

2013-03-06

The purpose of this study was to evaluate the efficacy and tolerability of weekly docetaxel, cisplatin, and S-1 (weekly TPS) as induction chemotherapy for patients with locally advanced head and neck squamous cell carcinoma (HNSCC). A total of 35 patients with previously untreated, locally advanced HNSCC were enrolled. Seven patients (20%) were diagnosed with stage III HNSCC and 28 patients (80%) were diagnosed with stage IV. Induction treatment included 30 mg/m(2) docetaxel on day 1 and 8, 60 mg/m(2) cisplatin on day 1, and 70 mg/m(2) S-1 on days 1 to 14. The regimen was repeated every 21 days. After three courses of induction chemotherapy, patients received concurrent chemoradiotherapy. Among the 35 patients, 30 (85.7%) completed induction chemotherapy. The response to induction chemotherapy was as follows: nine patients (25.7%) achieved a complete response (CR) and the overall response rate (ORR) was 85.7%. Grades 3-4 toxicity during induction therapy included neutropenia (28.5%), neutropenic fever (8.5%), and diarrhea (17.1%). After completion of concurrent chemoradiotherapy, the CR rate was 62.8% and the partial response (PR) was 22.8%. Estimates of progression-free and overall survival at 2 years were 73.2% and 79.3%, respectively. Weekly TPS is a promising regimen that is well-tolerated, causes minimal myelosuppression and is effective as an outpatient regimen for locally advanced HNSCC. ClinicalTrials.gov: NCT01645748.

Blastocyst-like structures generated solely from stem cells.

PubMed

Rivron, Nicolas C; Frias-Aldeguer, Javier; Vrij, Erik J; Boisset, Jean-Charles; Korving, Jeroen; Vivié, Judith; Truckenmüller, Roman K; van Oudenaarden, Alexander; van Blitterswijk, Clemens A; Geijsen, Niels

2018-05-01

The blastocyst (the early mammalian embryo) forms all embryonic and extra-embryonic tissues, including the placenta. It consists of a spherical thin-walled layer, known as the trophectoderm, that surrounds a fluid-filled cavity sheltering the embryonic cells 1 . From mouse blastocysts, it is possible to derive both trophoblast 2 and embryonic stem-cell lines 3 , which are in vitro analogues of the trophectoderm and embryonic compartments, respectively. Here we report that trophoblast and embryonic stem cells cooperate in vitro to form structures that morphologically and transcriptionally resemble embryonic day 3.5 blastocysts, termed blastoids. Like blastocysts, blastoids form from inductive signals that originate from the inner embryonic cells and drive the development of the outer trophectoderm. The nature and function of these signals have been largely unexplored. Genetically and physically uncoupling the embryonic and trophectoderm compartments, along with single-cell transcriptomics, reveals the extensive inventory of embryonic inductions. We specifically show that the embryonic cells maintain trophoblast proliferation and self-renewal, while fine-tuning trophoblast epithelial morphogenesis in part via a BMP4/Nodal-KLF6 axis. Although blastoids do not support the development of bona fide embryos, we demonstrate that embryonic inductions are crucial to form a trophectoderm state that robustly implants and triggers decidualization in utero. Thus, at this stage, the nascent embryo fuels trophectoderm development and implantation.

Ectopical expression of FABP4 gene can induce bovine muscle-derived stem cells adipogenesis.

PubMed

Zhang, Le; Zhao, Yanfang; Ning, Yue; Wang, Hongbao; Zan, Linsen

2017-01-08

Fatty acid binding protein 4 (FABP4) plays a key role in Fatty acid catabolism in mammals. Findings from our previous studies have indicated that FABP4 neither affect the differentiation of bovine preadipocytes nor does it change the expression of upstream genes. To investigate whether ectopically expressed FABP4 can induces Muscle-Derived Stem Cells (MDSCs) lipid synthesis and understand the regulatory mechanism behind it. In this study, adenoviruses infection is achieved to ectopically expressed FABP4 in bovine MDSCs, RNA-seq analyses at the very early stages of induction were performed to reveal gene expression level changes during MDSCs transdifferentiation. Results showed FABP4 can induce bovine Muscle-Derived Stem Cells transdifferentiation into adipocyte-like cells, 23 genes' expression levels changed after 24 h inducing although there is no significant change in cell phenotypes. Along with induction time, more differently expressed genes (256 genes changes after 48 h induction) were screened out. These genes should be at the downstream of signal pathways and be regulated by the 23 genes identified before. Our findings may provide a unique new model for studying the molecular control of cattle cross-talk between adipose and skeletal muscle. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Tolerance induction after specific immunotherapy with pollen allergoids adjuvanted by monophosphoryl lipid A in children

PubMed Central

Rosewich, M; Schulze, J; Eickmeier, O; Telles, T; Rose, M A; Schubert, R; Zielen, S

2010-01-01

Specific immunotherapy (SIT) is a well-established and clinically effective treatment for allergic diseases. A pollen allergoid formulated with the T helper type 1 (Th1)-inducing adjuvant monophosphoryl lipid A (MPL) facilitates short-term SIT. Little is known about mechanisms of tolerance induction in this setting. In a prospective study, 34 patients allergic to grass pollen (25 male, nine female, median age 10·2 years) received a total of 44 SIT courses (20 in the first, 24 in the second) with MPL-adjuvanted pollen allergoids. Immunogenicity was measured by levels of specific immunoglobulin G (IgGgrass) and IgG4grass by antibody blocking properties on basophil activation, and by induction of CD4+, CD25+ and forkhead box P3 (FoxP3+) regulatory T cells (Treg). Specific IgG and IgG4 levels increased only slightly in the first year of SIT. In the second year these changes reached significance (P < 0·0001). In keeping with these findings, we were able to show an increase of Treg cells and a decreased release of leukotrienes after the second year of treatment. In the first year of treatment we found little evidence for immunological changes. A significant antibody induction was seen only after the second course of SIT. Short-course immunotherapy with pollen allergoids formulated with the Th1-inducing adjuvant MPL needs at least two courses to establish tolerance. PMID:20345983

Tolerance induction after specific immunotherapy with pollen allergoids adjuvanted by monophosphoryl lipid A in children.

PubMed

Rosewich, M; Schulze, J; Eickmeier, O; Telles, T; Rose, M A; Schubert, R; Zielen, S

2010-06-01

Specific immunotherapy (SIT) is a well-established and clinically effective treatment for allergic diseases. A pollen allergoid formulated with the T helper type 1 (Th1)-inducing adjuvant monophosphoryl lipid A (MPL) facilitates short-term SIT. Little is known about mechanisms of tolerance induction in this setting. In a prospective study, 34 patients allergic to grass pollen (25 male, nine female, median age 10.2 years) received a total of 44 SIT courses (20 in the first, 24 in the second) with MPL-adjuvanted pollen allergoids. Immunogenicity was measured by levels of specific immunoglobulin G (IgG(grass)) and IgG4(grass) by antibody blocking properties on basophil activation, and by induction of CD4(+), CD25(+) and forkhead box P3 (FoxP3(+)) regulatory T cells (T(reg)). Specific IgG and IgG4 levels increased only slightly in the first year of SIT. In the second year these changes reached significance (P < 0.0001). In keeping with these findings, we were able to show an increase of T(reg) cells and a decreased release of leukotrienes after the second year of treatment. In the first year of treatment we found little evidence for immunological changes. A significant antibody induction was seen only after the second course of SIT. Short-course immunotherapy with pollen allergoids formulated with the Th1-inducing adjuvant MPL needs at least two courses to establish tolerance.

The GARP/Latent TGF-β1 complex on Treg cells modulates the induction of peripherally derived Treg cells during oral tolerance.

PubMed

Edwards, Justin P; Hand, Timothy W; Morais da Fonseca, Denise; Glass, Deborah D; Belkaid, Yasmine; Shevach, Ethan M

2016-06-01

Treg cells can secrete latent TGF-β1 (LTGF-β1), but can also utilize an alternative pathway for transport and expression of LTGF-β1 on the cell surface in which LTGF-β1 is coupled to a distinct LTGF-β binding protein termed glycoprotein A repetitions predominant (GARP)/LRRC32. The function of the GARP/LTGF-β1 complex has remained elusive. Here, we examine in vivo the roles of GARP and TGF-β1 in the induction of oral tolerance. When Foxp3(-) OT-II T cells were transferred to wild-type recipient mice followed by OVA feeding, the conversion of Foxp3(-) to Foxp3(+) OT-II cells was dependent on recipient Treg cells. Neutralization of IL-2 in the recipient mice also abrogated this conversion. The GARP/LTGF-β1 complex on recipient Treg cells, but not dendritic cell-derived TGF-β1, was required for efficient induction of Foxp3(+) T cells and for the suppression of delayed hypersensitivity. Expression of the integrin αvβ8 by Treg cells (or T cells) in the recipients was dispensable for induction of Foxp3 expression. Transient depletion of the bacterial flora enhanced the development of oral tolerance by expanding Treg cells with enhanced expression of the GARP/LTGF-β1 complex. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Recent thymic emigrants are tolerized in the absence of inflammation.

PubMed

Friesen, Travis J; Ji, Qingyong; Fink, Pamela J

2016-05-30

T cell development requires a period of postthymic maturation. Why this is the case has remained a mystery, particularly given the rigors of intrathymic developmental checkpoints, successfully traversed by only ∼5% of thymocytes. We now show that the first few weeks of T cell residence in the lymphoid periphery define a period of heightened susceptibility to tolerance induction to tissue-restricted antigens (TRAs), the outcome of which depends on the context in which recent thymic emigrants (RTEs) encounter antigen. After encounter with TRAs in the absence of inflammation, RTEs exhibited defects in proliferation, diminished cytokine production, elevated expression of anergy-associated genes, and diminished diabetogenicity. These properties were mirrored in vitro by enhanced RTE susceptibility to regulatory T cell-mediated suppression. In the presence of inflammation, RTEs and mature T cells were, in contrast, equally capable of inducing diabetes, proliferating, and producing cytokines. Thus, recirculating RTEs encounter TRAs during a transitional developmental stage that facilitates tolerance induction, but inflammation converts antigen-exposed, tolerance-prone RTEs into competent effector cells. © 2016 Friesen et al.

Role of Abscisic Acid in the Induction of Freezing Tolerance in Brassica napus Suspension-Cultured Cells 1

PubMed Central

Johnson-Flanagan, Anne M.; Huiwen, Zhong; Thiagarajah, Mohan R.; Saini, Hargurdeep S.

1991-01-01

Brassica napus suspension-cultured cells could be hardened in 6 days at 25°C by the addition of mefluidide or ABA to the culture medium. Cells treated with mefluidide (10 milligrams per liter) or ABA (50 micromolar) attained an LT50 of −17.5°C or −18°C, respectively, while the LT50 for the comparable nonhardened control (sucrose) was −10°C. The increased freezing tolerance of mefluidide-treated cells was paralleled by a 4- to 23-fold increase in ABA, as measured by gas-liquid chromatography using electron capture detection. Application of 1 milligram per liter of fluridone, an inhibitor of abscisic acid biosynthesis, prevented the mefluidide-induced increase in freezing tolerance and the accumulation of ABA. Both these inhibitory effects of fluridone were overridden by 50 micromolar ABA in the culture medium. On the basis of these results, we concluded that increased ABA levels are important for the induction of freezing tolerance in suspension-cultured cells. PMID:16668089

Immune tolerance induction in patients with haemophilia a and inhibitors: effectiveness and cost analysis in an European Cohort (The ITER Study).

PubMed

Rocino, A; Cortesi, P A; Scalone, L; Mantovani, L G; Crea, R; Gringeri, A

2016-01-01

Although immune tolerance induction (ITI) is considered the first choice treatment to eradicate inhibitors in haemophilia A patients, little is known about outcomes determinants and cost magnitude. A retrospective, multicentre study was conducted to assess the relationship between ITI outcome, clinical and treatment characteristics and cost of ITI treatment in haemophilia A patients. Data from 12 months before inhibitor diagnosis to 12 months after ITI completion were collected. Treatment cost was calculated in the third-party perspective and expressed as mean € per patient-month. Cox regression models were used to identify predictors of better outcome and the time taken to achieve tolerance. Seventy-one patients, aged 0.4-41 years (median: 3.8 years) at ITI start, were enrolled. Undetectable inhibitor was achieved in 84.5% of patients and inhibitor eradication with normal factor VIII (FVIII) pharmacokinetics in 74.2%. Median time to successful tolerance was 10.7 months (range 2.0-90.0 months). Peak inhibitor level on ITI was a significant predictor of ITI success. Breakthrough bleeding event incidence during ITI was associated with time to success. The mean cost of treatment for the time period between inhibitor diagnosis and ITI start was €3188 per patient-month (92.1% for bypassing agents), and €60 078 during ITI (76.8% for FVIII use in ITI). Immune tolerance induction in this patient cohort was successful in 84.5% of patients with a mean cost of €60 000 per patient-month. This high cost is dwarfed by comparison with the prospect of lifelong care of an inhibitor patient, in addition to gains in life expectancy and health-related quality of life. © 2015 John Wiley & Sons Ltd.

MHC-mismatched mixed chimerism restores peripheral tolerance of noncross-reactive autoreactive T cells in NOD mice

PubMed Central

Zhang, Mingfeng; Racine, Jeremy J.; Lin, Qing; Liu, Yuqing; Tang, Shanshan; Qin, Qi; Qi, Tong; Riggs, Arthur D.; Zeng, Defu

2018-01-01

Autoimmune type 1 diabetes (T1D) and other autoimmune diseases are associated with particular MHC haplotypes and expansion of autoreactive T cells. Induction of MHC-mismatched but not -matched mixed chimerism by hematopoietic cell transplantation effectively reverses autoimmunity in diabetic nonobese diabetic (NOD) mice, even those with established diabetes. As expected, MHC-mismatched mixed chimerism mediates deletion in the thymus of host-type autoreactive T cells that have T-cell receptor (TCR) recognizing (cross-reacting with) donor-type antigen presenting cells (APCs), which have come to reside in the thymus. However, how MHC-mismatched mixed chimerism tolerizes host autoreactive T cells that recognize only self-MHC–peptide complexes remains unknown. Here, using NOD.Rag1−/−.BDC2.5 or NOD.Rag1−/−.BDC12-4.1 mice that have only noncross-reactive transgenic autoreactive T cells, we show that induction of MHC-mismatched but not -matched mixed chimerism restores immune tolerance of peripheral noncross-reactive autoreactive T cells. MHC-mismatched mixed chimerism results in increased percentages of both donor- and host-type Foxp3+ Treg cells and up-regulated expression of programmed death-ligand 1 (PD-L1) by host-type plasmacytoid dendritic cells (pDCs). Furthermore, adoptive transfer experiments showed that engraftment of donor-type dendritic cells (DCs) and expansion of donor-type Treg cells are required for tolerizing the noncross-reactive autoreactive T cells in the periphery, which are in association with up-regulation of host-type DC expression of PD-L1 and increased percentage of host-type Treg cells. Thus, induction of MHC-mismatched mixed chimerism may establish a peripheral tolerogenic DC and Treg network that actively tolerizes autoreactive T cells, even those with no TCR recognition of the donor APCs. PMID:29463744

Induction of metallothionein in chick embryos as a mechanism of tolerance to platinum group metal exposure.

PubMed

Gagnon, Zofia E; Patel, Amit

2007-02-15

Recent data show that platinum group metals (PGMs), primarily platinum (Pt), palladium (Pd) and rhodium (Rd), from automobile catalytic converters are being deposited in the environment. We investigated the PGM neurotoxicity and tolerance mechanism by induction of metallothionein (MT) in developing chick embryos. Chick embryos were injected on the 7th and 14th days of incubation with different concentrations of Pt and mixture of Pt, Pd and Rh (PGM mix) solutions. It is documented that induction of MT by zinc (Zn+2) protects against metal and non-metal hepatotoxicity. In this study the MT induction was examined through pretreatment of the two highest Pt(IV) exposure levels with exogenous Zn2+ on the 4th and 11th days of incubation. SDS-PAGE assay and digital image system were used to identify and quantify MT in homogenized brain and liver tissues. Quantitative analysis revealed an increase of MT in the 5 ppm Pt exposure as compared to controls. The 10 ppm Pt treatment was a lethal dose for exposed embryos. There was increased mortality at the 1.0 PGM mix level. The interaction of Pt, Pd and Rh in the mixture seems to favor metal accumulation and MT induction in the liver but not the brain. Pretreatment with exogenous Zn2+ increased chick survival. These results indicate that induction of MT plays a protective role against PGM toxicity. Metal analysis using atomic absorption spectrometer in graphite furnace mode (GFAAS) revealed PGM accumulation in chick embryo liver and brain tissues proportional to exposure concentration. Our results may imply that MT has an important role as a tolerance mechanism against PGM toxicity. The presence of Pt(IV) in brain tissue suggests that the undeveloped blood-brain barrier is permeable to PGMs. This raises concerns regarding the implication of these metals on neural injury.

A myo-inositol-1-phosphate synthase gene, IbMIPS1, enhances salt and drought tolerance and stem nematode resistance in transgenic sweet potato.

PubMed

Zhai, Hong; Wang, Feibing; Si, Zengzhi; Huo, Jinxi; Xing, Lei; An, Yanyan; He, Shaozhen; Liu, Qingchang

2016-02-01

Myo-inositol-1-phosphate synthase (MIPS) is a key rate limiting enzyme in myo-inositol biosynthesis. The MIPS gene has been shown to improve tolerance to abiotic stresses in several plant species. However, its role in resistance to biotic stresses has not been reported. In this study, we found that expression of the sweet potato IbMIPS1 gene was induced by NaCl, polyethylene glycol (PEG), abscisic acid (ABA) and stem nematodes. Its overexpression significantly enhanced stem nematode resistance as well as salt and drought tolerance in transgenic sweet potato under field conditions. Transcriptome and real-time quantitative PCR analyses showed that overexpression of IbMIPS1 up-regulated the genes involved in inositol biosynthesis, phosphatidylinositol (PI) and ABA signalling pathways, stress responses, photosynthesis and ROS-scavenging system under salt, drought and stem nematode stresses. Inositol, inositol-1,4,5-trisphosphate (IP3 ), phosphatidic acid (PA), Ca(2+) , ABA, K(+) , proline and trehalose content was significantly increased, whereas malonaldehyde (MDA), Na(+) and H2 O2 content was significantly decreased in the transgenic plants under salt and drought stresses. After stem nematode infection, the significant increase of inositol, IP3 , PA, Ca(2+) , ABA, callose and lignin content and significant reduction of MDA content were found, and a rapid increase of H2 O2 levels was observed, peaked at 1 to 2 days and thereafter declined in the transgenic plants. This study indicates that the IbMIPS1 gene has the potential to be used to improve the resistance to biotic and abiotic stresses in plants. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Overcoming the response plateau in multiple myeloma: A novel bortezomib-based strategy for secondary induction and high-yield CD34+ stem cell mobilization

PubMed Central

Niesvizky, Ruben; Mark, Tomer M.; Ward, Maureen; Jayabalan, David S.; Pearse, Roger N.; Manco, Megan; Stern, Jessica; Christos, Paul J.; Mathews, Lena; Shore, Tsiporah B.; Zafar, Faiza; Pekle, Karen; Xiang, Zhaoying; Ely, Scott; Skerret, Donna; Chen-Kiang, Selina; Coleman, Morton; Lane, Maureen E.

2014-01-01

Purpose This phase 2 study evaluated bortezomib-based secondary induction and stem cell mobilization in 38 transplant-eligible myeloma patients who had an incomplete and stalled response to, or had relapsed after, previous immunomodulatory drug-based induction. Experimental design Patients received up to six 21-day cycles of bortezomib plus dexamethasone, with added liposomal doxorubicin for patients not achieving partial response or better by cycle 2 or very good partial response or better (≥VGPR) by cycle 4 (DoVeD), followed by bortezomib, high-dose cyclophosphamide, and filgrastim mobilization. Gene expression/signaling pathway analyses were conducted in purified CD34+ cells post-bortezomib-based mobilization and compared against patients who received only filgrastim ± cyclophosphamide. Plasma samples were similarly analyzed for quantification of associated protein markers. Results The response rate to DoVeD relative to the pre-DoVeD baseline was 61%, including 39% ≥VGPR. Deeper responses were achieved in 10 of 27 patients who received bortezomib-based mobilization; post-mobilization response rate was 96%, including 48% ≥VGPR, relative to the pre-DoVeD baseline. Median CD34+ cell yield was 23.2 × 106 cells/kg (median of 1 apheresis session). After a median follow-up of 46.6 months, median progression-free survival was 47.1 months from DoVeD initiation;5-year overall survival rate was 76.4%. Grade ≥3 adverse events included thrombocytopenia (13%), hand-foot syndrome (11%), peripheral neuropathy (8%), and neutropenia (5%). Bortezomib-based mobilization was associated with modulated expression of genes involved in stem cell migration. Conclusion Bortezomib-based secondary induction and mobilization could represent an alternative strategy for elimination of tumor burden in immunomodulatory drug-resistant patients that does not impact stem cell yield. PMID:23357980

Tolerance and immunity in mice infected with herpes simplex virus: simultaneous induction of protective immunity and tolerance to delayed-type hypersensitivity.

PubMed

Nash, A A; Gell, P G; Wildy, P

1981-05-01

Unresponsiveness to delayed type hypersensitivity was induced in mice following an intravenous injection of herpes simplex virus. The principal tolerogens used were thymidine kinase-deficient virus mutants which grow poorly in vivo; u.v.-inactivated and to a lesser extent formalin-inactivated virus were also tolerogenic. The tolerance induced was specific for the virus type. Despite the tolerance to delayed hypersensitivity, anti-viral immunity is present as determined by the rapid inactivation of infectious virus. The mechanism of tolerance to herpes virus and the importance of these observations for the pathogenesis of viral disease is discussed.

Tolerance and immunity in mice infected with herpes simplex virus: simultaneous induction of protective immunity and tolerance to delayed-type hypersensitivity.

PubMed Central

Nash, A A; Gell, P G; Wildy, P

1981-01-01

Unresponsiveness to delayed type hypersensitivity was induced in mice following an intravenous injection of herpes simplex virus. The principal tolerogens used were thymidine kinase-deficient virus mutants which grow poorly in vivo; u.v.-inactivated and to a lesser extent formalin-inactivated virus were also tolerogenic. The tolerance induced was specific for the virus type. Despite the tolerance to delayed hypersensitivity, anti-viral immunity is present as determined by the rapid inactivation of infectious virus. The mechanism of tolerance to herpes virus and the importance of these observations for the pathogenesis of viral disease is discussed. PMID:7251047

40 CFR 180.493 - Dimethomorph; tolerances for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

... grapes grown for raisin production. (b) Section 18 emergency exemptions. [Reserved] (c) Tolerances with... stem, subgroup 5A 2.0 Brassica, leafy greens, subgroup 5B 20.0 Ginseng 0.90 Grape, raisin 1 6.0 Hop... or on the following commodities: Commodity Parts per million Bean, lima, succulent 0.60 Grape 3.5 (d...

From Zero Tolerance to a Culture of Care

ERIC Educational Resources Information Center

Cassidy, Wanda

2005-01-01

Zero tolerance policies stem from the culture of fear that pervades many schools today--fear of violence, bullying, and unruly behaviour. The code of conduct is clearly spelled out and if students disobey, the retribution is swift--usually suspension or expulsion. The rules are designed to apply equally to everyone, irrespective of age, gender,…

Involvement of dendritic cells in allograft rejection new implications of dendritic cell-endothelial cell interactions.

PubMed

Schlichting, C L; Schareck, W D; Kofler, S; Weis, M

2007-04-01

For almost half a century immunologists have tried to tear down the MHC barrier, which separates two unrelated individuals during transplantation. Latest experimental data suggest that a breakthrough in vitro is imminent. Dendritic cells (DCs), which activate naïve allo-reactive T-cells (TCs), play a central role in the establishment of allo-antigen-specific immunity. Allograft solid organ rejection is initiated at the foreign endothelial cell (EC) layer, which forms an immunogenic barrier for migrating DCs. Thus, DC/EC interactions might play a crucial role in antigen-specific allograft rejection. Organ rejection is mediated by host allo-reactive TCs, which are activated by donor DCs (direct activation) or host DCs (indirect activation). Direct allo-antigen presentation by regulatory dendritic cells (DCreg) can play an instructive role towards tolerance induction. Several groups established that, DCregs, if transplanted beforehand, enter host thymus, spleen, or bone marrow where they might eventually establish allo-antigen-specific tolerance. A fundamental aspect of DC function is migration throughout the entire organism. After solid organ transplantation, host DCs bind to ECs, invade allograft tissues, and finally transmigrate into lymphoid vessels and secondary lymphoid organs, where they present allo-antigens to naïve host TCs. Recent data suggest that in vitro manipulated DCregs may mediate allo-transplantation tolerance induction. However, the fundamental mechanisms on how such DCregs cause host TCs in the periphery towards tolerance remain unclear. One very promising experimental concept is the simultaneous manipulation of DC direct and indirect TC activation/suppression, towards donor antigen-specific allo-transplantation tolerance. The allo-antigen-specific long-term tolerance induction mediated by DCreg pre-transplantation (with simultaneous short-term immunosuppression) has become reproducible in the laboratory animal setting. Despite the shortcomings of laboratory animal studies, strong promises are deriving from these studies for clinical kidney, heart, and liver transplantation.

Stem water transport and freeze-thaw xylem embolism in conifers and angiosperms in a Tasmanian treeline heath.

PubMed

Feild, Taylor S; Brodribb, Tim

2001-05-01

The effect of freezing on stem xylem hydraulic conductivity and leaf chlorophyll a fluorescence was measured in 12 tree and shrub species from a treeline heath in Tasmania, Australia. Reduction in stem hydraulic conductivity after a single freeze-thaw cycle was minimal in conifers and the vessel-less angiosperm species Tasmannia lanceolata (Winteraceae), whereas mean loss of conductivity in vessel-forming angiosperms fell in the range 17-83%. A positive linear relationship was observed between percentage loss of hydraulic conductivity by freeze-thaw and the average conduit diameter across all 12 species. This supports the hypothesis that large-diameter vascular conduits have a greater likelihood of freeze-thaw cavitation because larger bubbles are produced, which are more likely to expand under tension. Leaf frost tolerances, as measured by a 50% loss of maximum PSII quantum yield, varied from -6 to -13°C, indicating that these species were more frost-sensitive than plants from northern hemisphere temperate forest and treeline communities. There was no evidence of a relationship between frost tolerance of leaves and the resilience of stem water transport to freezing, suggesting that low temperature survival and the resistance of stem water transport to freezing are independently evolving traits. The results of this study bear on the ecological importance of stem freezing in the southern hemisphere treeline zones.

Antigen-Conjugated Human IgE Induces Antigen-Specific T Cell Tolerance in a Humanized Mouse Model

PubMed Central

Baravalle, Günther; Greer, Alexandra M.; LaFlam, Taylor N.; Shin, Jeoung-Sook

2015-01-01

Dendritic cells (DCs) play an important role in immune homeostasis through their ability to present Ags at steady state and mediate T cell tolerance. This characteristic renders DCs an attractive therapeutic target for the induction of tolerance against auto-antigens or allergens. Accordingly, Ag-conjugated DC–specific Abs have been proposed to be an excellent vehicle to deliver Ags to DCs for presentation and tolerance induction. However, this approach requires laborious reagent generation procedures and entails unpredictable side effects resulting from Ab-induced crosslinking of DC surface molecules. In this study, we examined whether IgE, a high-affinity, non–cross-linking natural ligand of FcεRI, could be used to target Ags to DCs and to induce Ag-specific T cell tolerance. We found that Ag-conjugated human IgE Fc domain (Fcε) effectively delivered Ags to DCs and enhanced Ag presentation by 1000- to 2500-fold in human FcεRIα-transgenic mice. Importantly, this presentation resulted in a systemic deletion of Ag-specific T cells and prevented these mice from developing delayed-type hypersensitivity, which is critically dependent on Ag-specific T cell immunity. Thus, targeting FcεRI on DCs via Ag-Fcε fusion protein may serve an alternative method to induce Ag-specific T cell tolerance in humans. PMID:24610015

Molecular insight in gastric cancer induction: an overview of cancer stemness genes.

PubMed

Akhavan-Niaki, Haleh; Samadani, Ali Akbar

2014-04-01

Gastric cancer is one of the most outgoing human cancers in the world. Two main functional types were described: Intestinal adenocarcinoma and diffuse one. The most important purpose of this review is to analyze and investigate the main genetic factors involved in tumorogenesis of stomach and the molecular mechanism of their expression regulation alongside with the importance of cancer stem cells and their relationship with gastric cancer. It is evident that proper diagnosis of molecular case of cancer may lead to absolute treatment and at least reduction in the disease severity. However, stemness factors such as Sox2, Oct3/4, and Nanog were related with induced pluripotent stem cells, proposing a correlation between these stemness factors and cancer stem cells. Moreover, aberrant induction by Helicobacter pylori of the intestinal-specific homeobox transcription factors, CDX1 and CDX2, also plays an important role in this modification. There are some genes which are directly activated by CDX1 in gastric cancer and distinguished stemness-related reprogramming factors like SALL4 and KLF5. Correspondingly, we also aimed to present the main important epigenetic changes such as DNA methylation, histone modification, and chromatin modeling of stemness genes in disease development. Remarkably, a better understanding of molecular bases of cancer may lead to novel diagnostic, therapeutic, and preventive approaches by some genetic and epigenetic changes such as gene amplifications, gene silencing by DNA methylation, losses of imprinting, LOH, and mutations. Consequently, genome-wide searches of gene expression are widely important for surveying the proper mechanisms of cancer emergence and development. Conspicuously, this review explains an outline of the molecular mechanism and new approaches in gastric cancer.

A moderate decrease in temperature induces COR15a expression through the CBF signaling cascade and enhances freezing tolerance.

PubMed

Wang, Yi; Hua, Jian

2009-10-01

Temperature has a profound effect on plant growth and development. However, the molecular mechanisms underlying this regulation are not well understood. In particular, how moderate temperature variations are perceived and transduced inside the plant cells remains obscure. In this study, we analyzed transcriptional responses to a moderate decrease in temperature (cooling) in Arabidopsis thaliana. The cooling response involves a weaker and more transient induction of cold-induced genes, such as COR15a, than cold response. This induction probably accounts for the increase in freezing tolerance by cooling acclimation. Cooling also induces some defense response genes, and their induction, but not that of COR15a, requires the salicylic acid signaling pathway. Analysis of the regulation of COR15a reveals that cooling induction is mediated through the same C repeat/dehydration-responsive (CRT/DRE) element as cold induction. Furthermore, we identified a role for CBF1 and CBF4 in transducing signals of moderate decreases in temperature. It appears that variants of the CBF signaling cascade are utilized in cold and cooling responses, and a moderate decrease in temperature may invoke an adaptive response to prepare plants to cope with a more drastic decrease in temperature.

In vitro effects of two silicate-based materials, Biodentine and BioRoot RCS, on dental pulp stem cells in models of reactionary and reparative dentinogenesis

PubMed Central

Loison-Robert, Ludwig Stanislas; Berbar, Tsouria; Isaac, Juliane; Berdal, Ariane; Simon, Stéphane

2018-01-01

Background Calcium silicate-based cements are biomaterials with calcium oxide and carbonate filler additives. Their properties are close to those of dentin, making them useful in restorative dentistry and endodontics. The aim of this study was to evaluate the in vitro biological effects of two such calcium silicate cements, Biodentine (BD) and Bioroot (BR), on dental stem cells in both direct and indirect contact models. The two models used aimed to mimic reparative dentin formation (direct contact) and reactionary dentin formation (indirect contact). An original aspect of this study is the use of an interposed thin agarose gel layer to assess the effects of diffusible components from the materials. Results The two biomaterials were compared and did not modify dental pulp stem cell (DPSC) proliferation. BD and BR showed no significant cytotoxicity, although some cell death occurred in direct contact. No apoptosis or inflammation induction was detected. A striking increase of mineralization induction was observed in the presence of BD and BR, and this effect was greater in direct contact. Surprisingly, biomineralization occurred even in the absence of mineralization medium. This differentiation was accompanied by expression of odontoblast-associated genes. Exposure by indirect contact did not stimulate the induction to such a level. Conclusion These two biomaterials both seem to be bioactive and biocompatible, preserving DPSC proliferation, migration and adhesion. The observed strong mineralization induction through direct contact highlights the potential of these biomaterials for clinical application in dentin-pulp complex regeneration. PMID:29370163

Stem cell facelift: between reality and fiction.

PubMed

Atiyeh, Bishara S; Ibrahim, Amir E; Saad, Dibo A

2013-03-01

Stem cells are "big business" throughout medical technology, and their potential application in cosmetic procedures is no exception. One of the latest nonsurgical facial treatments (and new catchphrases) in plastic surgery is the "stem cell facelift." It is evident from the currently available scientific literature that the use of stem cell therapy for facial rejuvenation is limited to the theoretical induction of skin tightening and can in no way be equated to a facelift. In fact, what is advertised and promoted as a new and original technique of stem cell facelifting is mostly stem cell-enriched lipofilling. Despite encouraging data suggesting that adult stem cells hold promise for future applications, the data from clinical evidence available today do not substantiate the marketing and promotional claims being made to patients. To claim that the "stem cell facelift" is a complete facial rejuvenation procedure surgery is unethical.

Embolism and mechanical resistances play a key role in dehydration tolerance of a perennial grass Dactylis glomerata L.

PubMed

Volaire, Florence; Lens, Frederic; Cochard, Hervé; Xu, Hueng; Chacon-Doria, Larissa; Bristiel, Pauline; Balachowski, Jennifer; Rowe, Nick; Violle, Cyrille; Picon-Cochard, Catherine

2018-05-17

More intense droughts under climate change threaten species resilience. Hydraulic strategies determine drought survival in woody plants but have been hardly studied in herbaceous species. We explored the intraspecific variability of hydraulic and morphological traits as indicators of dehydration tolerance in a perennial grass, cocksfoot (Dactylis glomerata), which has a large biogeographical distribution in Europe. Twelve populations of cocksfoot originating from Mediterranean, Temperate and Northern European areas were grown in a controlled environment in pots. Dehydration tolerance, leaf and stem anatomical traits and xylem pressure associated with 88 or 50 % loss of xylem conductance (P88, P50) were measured. Across the 12 populations of cocksfoot, P50 ranged from -3.06 to - 6.36 MPa, while P88 ranged from -5.06 to -11.6 MPa. This large intraspecific variability of embolism thresholds corresponded with the biogeographical distribution and some key traits of the populations. In particular, P88 was correlated with dehydration tolerance (r = -0.79). The dehydration-sensitive Temperate populations exhibited the highest P88 (-6.1 MPa). The most dehydration-tolerant Mediterranean populations had the greatest leaf dry matter content and leaf fracture toughness, and the lowest P88 (-10.4 MPa). The Northern populations displayed intermediate trait values, potentially attributable to frost resistance. The thickness of metaxylem vessel walls in stems was highly correlated with P50 (r = -0.92), but no trade-off with stem lignification was observed. The relevance of the linkage between hydraulic and stomatal traits is discussed for drought survival in perennial grasses. Compared with woody species, the large intraspecific variability in dehydration tolerance and embolism resistance within cocksfoot has consequences for its sensitivity to climate change. To better understand adaptive strategies of herbaceous species to increasing drought and frost requires further exploration of the role of hydraulic and mechanical traits using a larger inter- and intraspecific range of species.

Tolerance to Acetaminophen Hepatotoxicity in the Mouse Model of Autoprotection is Associated with Induction of Flavin-containing Monooxygenase-3 (FMO3) in Hepatocytes

EPA Science Inventory

Acetaminophen (APAP) pretreatment with a low hepatotoxic dose in mice results in resistance to a second, higher dose of APAP (APAP autoprotection). Recent microarray work by our group showed a drastic induction of liver flavin containing monooxygenase-3 (Fmo3) mRNA expression in...

Catechins activate muscle stem cells by Myf5 induction and stimulate muscle regeneration.

PubMed

Kim, A Rum; Kim, Kyung Min; Byun, Mi Ran; Hwang, Jun-Ha; Park, Jung Il; Oh, Ho Taek; Kim, Hyo Kyeong; Jeong, Mi Gyeong; Hwang, Eun Sook; Hong, Jeong-Ho

2017-07-22

Muscle weakness is one of the most common symptoms in aged individuals and increases risk of mortality. Thus, maintenance of muscle mass is important for inhibiting aging. In this study, we investigated the effect of catechins, polyphenol compounds in green tea, on muscle regeneration. We found that (-)-epicatechin gallate (ECG) and (-)-epigallocatechin-3-gallate (EGCG) activate satellite cells by induction of Myf5 transcription factors. For satellite cell activation, Akt kinase was significantly induced after ECG treatment and ECG-induced satellite cell activation was blocked in the presence of Akt inhibitor. ECG also promotes myogenic differentiation through the induction of myogenic markers, including Myogenin and Muscle creatine kinase (MCK), in satellite and C2C12 myoblast cells. Finally, EGCG administration to mice significantly increased muscle fiber size for regeneration. Taken together, the results suggest that catechins stimulate muscle stem cell activation and differentiation for muscle regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

Gene silencing efficiency and INF-β induction effects of splicing miRNA 155-based artificial miRNA with pre-miRNA stem-loop structures.

PubMed

Sin, Onsam; Mabiala, Prudence; Liu, Ye; Sun, Ying; Hu, Tao; Liu, Qingzhen; Guo, Deyin

2012-02-01

Artificial microRNA (miRNA) expression vectors have been developed and used for RNA interference. The secondary structure of artificial miRNA is important for RNA interference efficacy. We designed two groups of six artificial splicing miRNA 155-based miRNAs (SM155-based miRNAs) with the same target in the coding region or 3' UTR of a target gene and studied their RNA silencing efficiency and interferon β (IFN-β) induction effects. SM155-based miRNA with a mismatch at the +1 position and a bulge at the +11, +12 positions in a miRNA precursor stem-loop structure showed the highest gene silencing efficiency and lowest IFN-β induction effect (increased IFN-β mRNA level by 10% in both target cases), regardless of the specificity of the target sequence, suggesting that pSM155-based miRNA with this design could be a valuable miRNA expression vector.

Vascular Cell Induction Culture System Using Arabidopsis Leaves (VISUAL) Reveals the Sequential Differentiation of Sieve Element-Like Cells.

PubMed

Kondo, Yuki; Nurani, Alif Meem; Saito, Chieko; Ichihashi, Yasunori; Saito, Masato; Yamazaki, Kyoko; Mitsuda, Nobutaka; Ohme-Takagi, Masaru; Fukuda, Hiroo

2016-06-01

Cell differentiation is a complex process involving multiple steps, from initial cell fate specification to final differentiation. Procambial/cambial cells, which act as vascular stem cells, differentiate into both xylem and phloem cells during vascular development. Recent studies have identified regulatory cascades for xylem differentiation. However, the molecular mechanism underlying phloem differentiation is largely unexplored due to technical challenges. Here, we established an ectopic induction system for phloem differentiation named Vascular Cell Induction Culture System Using Arabidopsis Leaves (VISUAL). Our results verified similarities between VISUAL-induced Arabidopsis thaliana phloem cells and in vivo sieve elements. We performed network analysis using transcriptome data with VISUAL to dissect the processes underlying phloem differentiation, eventually identifying a factor involved in the regulation of the master transcription factor gene APL Thus, our culture system opens up new avenues not only for genetic studies of phloem differentiation, but also for future investigations of multidirectional differentiation from vascular stem cells. © 2016 American Society of Plant Biologists. All rights reserved.

Dental Pulp Stem Cell-Derived, Scaffold-Free Constructs for Bone Regeneration.

PubMed

Tatsuhiro, Fukushima; Seiko, Tatehara; Yusuke, Takebe; Reiko, Tokuyama-Toda; Kazuhito, Satomura

2018-06-22

In the present study, a scaffold-free tissue construct was developed as an approach for the regeneration of tissue defects, which produced good outcomes. We fabricated a scaffold-free tissue construct from human dental pulp stem cells (hDPSCs construct), and examined the characteristics of the construct. For its fabrication, basal sheets prepared by 4-week hDPSCs culturing were subjected to 1-week three-dimensional culture, with or without osteogenic induction, whereas hDPSC sheets (control) were fabricated by 1-week culturing of basal sheets on monolayer culture. The hDPSC constructs formed a spherical structure and calcified matrix that are absent in the control. The expression levels for bone-related genes in the hDPSC constructs were significantly upregulated compared with those in the control. Moreover, the hDPSC constructs with osteogenic induction had a higher degree of calcified matrix formation, and higher expression levels for bone-related genes, than those for the hDPSC constructs without osteogenic induction. These results suggest that the hDPSC constructs with osteogenic induction are composed of cells and extracellular and calcified matrices, and that they can be a possible scaffold-free material for bone regeneration.

The use of human tumour cell lines in the discovery of new cancer chemotherapeutic drugs.

PubMed

Baguley, Bruce C; Marshall, Elaine S

2008-02-01

Human tumour cell lines have played a major role in anticancer drug discovery, but cell lines may model only some aspects of tumour behaviour in cancer patients. Growing evidence supports a theory that stem cells with self-renewing properties sustain tumours. This review considers the extent to which a deeper understanding of the origin and properties of tumour cell lines might lead to new strategies for anticancer drug discovery. Recent literature on normal and tumour stem cells is reviewed and placed in the context of a discussion on the derivation and properties of tumour cell lines. Early-passage cell lines may model the more rapidly proliferating cells in human tumours and, thus, retain some of the properties of tumour stem cells. The effects of anticancer drugs on cell lines should be considered not only with regards to the induction of apoptosis, but also to the induction of senescence or other pathways that lead to host immune and inflammatory responses.

Recent Advances towards the Clinical Application of Stem Cells for Retinal Regeneration

PubMed Central

Becker, Silke; Jayaram, Hari; Limb, G. Astrid

2012-01-01

Retinal degenerative diseases constitute a major cause of irreversible blindness in the world. Stem cell-based therapies offer hope for these patients at risk of or suffering from blindness due to the deterioration of the neural retina. Various sources of stem cells are currently being investigated, ranging from human embryonic stem cells to adult-derived induced pluripotent stem cells as well as human Müller stem cells, with the first clinical trials to investigate the safety and tolerability of human embryonic stem cell-derived retinal pigment epithelium cells having recently commenced. This review aims to summarize the latest advances in the development of stem cell strategies for the replacement of retinal neurons and their supportive cells, the retinal pigment epithelium (RPE) affected by retinal degenerative conditions. Particular emphasis will be given to the advances in stem cell transplantation and the challenges associated with their translation into clinical practice. PMID:24710533

Stepwise differentiation of pluripotent stem cells into osteoblasts using four small molecules under serum-free and feeder-free conditions.

PubMed

Kanke, Kosuke; Masaki, Hideki; Saito, Taku; Komiyama, Yuske; Hojo, Hironori; Nakauchi, Hiromitsu; Lichtler, Alexander C; Takato, Tsuyoshi; Chung, Ung-Il; Ohba, Shinsuke

2014-06-03

Pluripotent stem cells are a promising tool for mechanistic studies of tissue development, drug screening, and cell-based therapies. Here, we report an effective and mass-producing strategy for the stepwise differentiation of mouse embryonic stem cells (mESCs) and mouse and human induced pluripotent stem cells (miPSCs and hiPSCs, respectively) into osteoblasts using four small molecules (CHIR99021 [CHIR], cyclopamine [Cyc], smoothened agonist [SAG], and a helioxanthin-derivative 4-(4-methoxyphenyl)pyrido[4',3':4,5]thieno[2,3-b]pyridine-2-carboxamide [TH]) under serum-free and feeder-free conditions. The strategy, which consists of mesoderm induction, osteoblast induction, and osteoblast maturation phases, significantly induced expressions of osteoblast-related genes and proteins in mESCs, miPSCs, and hiPSCs. In addition, when mESCs defective in runt-related transcription factor 2 (Runx2), a master regulator of osteogenesis, were cultured by the strategy, they molecularly recapitulated osteoblast phenotypes of Runx2 null mice. The present strategy will be a platform for biological and pathological studies of osteoblast development, screening of bone-augmentation drugs, and skeletal regeneration.

Induction of human umbilical Wharton's jelly-derived mesenchymal stem cells toward motor neuron-like cells.

PubMed

Bagher, Zohreh; Ebrahimi-Barough, Somayeh; Azami, Mahmoud; Mirzadeh, Hamid; Soleimani, Mansooreh; Ai, Jafar; Nourani, Mohammad Reza; Joghataei, Mohammad Taghi

2015-10-01

The most important property of stem cells from different sources is the capacity to differentiate into various cells and tissue types. However, problems including contamination, normal karyotype, and ethical issues cause many limitations in obtaining and using these cells from different sources. The cells in Wharton's jelly region of umbilical cord represent a pool source of primitive cells with properties of mesenchymal stem cells (MSCs). The aim of this study was to determine the potential of human Wharton's jelly-derived mesenchymal stem cells (WJMSCs) for differentiation to motor neuron cells. WJMSCs were induced to differentiate into motor neuron-like cells by using different signaling molecules and neurotrophic factors in vitro. Differentiated neurons were then characterized for expression of motor neuron markers including nestin, PAX6, NF-H, Islet 1, HB9, and choline acetyl transferase (ChAT) by quantitative reverse transcription PCR and immunocytochemistry. Our results showed that differentiated WJMSCs could significantly express motor neuron biomarkers in RNA and protein levels 15 d post induction. These results suggested that WJMSCs can differentiate to motor neuron-like cells and might provide a potential source in cell therapy for neurodegenerative disease.

Enhancement of neuronal differentiation by using small molecules modulating Nodal/Smad, Wnt/β-catenin, and FGF signaling.

PubMed

Song, Yonghee; Lee, Somyung; Jho, Eek-Hoon

2018-06-08

Pluripotent embryonic stem cells are one of the best modalities for the disease treatment due to their potential for self-renewal and differentiation into various cell types. Induction of stem cell differentiation into specific cell lineages has been investigated for decades, especially in vitro neuronal differentiation of embryonic stem cells. However, in vitro differentiation methods do not yield sufficient amounts of neurons for use in the therapeutic treatment of neurological disorders. Here, we provide an improved neuronal differentiation method based on a combination of small regulatory molecules for specific signaling pathways (FGF4 for FGF signaling, SB431542 for Nodal/Smad signaling, and XAV939 and BIO for Wnt signaling) in N2B27 media. We found that FGF4 was required for neural induction, SB431542 accelerated neural precursor differentiation, and treatment with XAV939 and BIO at different periods enhanced neuronal differentiation. These optimized neuronal differentiation conditions may allow a greater neuron cell yield within a shorter time than current methods and be the basis for treatment of neurological dysfunction using stem cells. Copyright © 2018. Published by Elsevier Inc.

Mechanical stretch endows mesenchymal stem cells stronger angiogenic and anti-apoptotic capacities via NFκB activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Zhuoli; Gan, Xueqi; Fan, Hongyi

Mesenchymal stem cells (MSCs) have been broadly used for tissue regeneration and repair due to their broad differentiation potential and potent paracrine properties such as angiogenic capacity. Strategies to increase their survival rate after transplantation and the angiogenic ability are of priority for the utility of MSCs. In this study, we found that mechanical stretch (10% extension, 30 cycles/min cyclic stretch) preconditioning increase the angiogenic capacity via VEGFA induction. In addition, mechanical stretch also increases the survival rate of mesenchymal stem cells under nutrients deprivation. Consistent with the increase VEGFA expression and resistance to apoptosis, nuclear localization of NFκB activity p65more » increased upon mechanical stretch. Inhibition of NFκB activity by BAY 11-708 blocks the pro-angiogenesis and anti-apoptosis function of mechanical stretch. Taken together, our findings here raise the possibility that mechanical stretch preconditioning might enhance the therapeutic efficacy of mesenchymal stem cells. - Highlights: • Mechanical stretch increases the angiogenic capacity via VEGFA induction in MSCs. • Mechanical stretch increases the survival rate of MSCs under nutrients deprivation. • Mechanical stretch manipulates MSCs via the activation of NFκB.« less

CD95/Fas Increases Stemness in Cancer Cells by Inducing a STAT1-Dependent Type I Interferon Response.

PubMed

Qadir, Abdul S; Ceppi, Paolo; Brockway, Sonia; Law, Calvin; Mu, Liang; Khodarev, Nikolai N; Kim, Jung; Zhao, Jonathan C; Putzbach, William; Murmann, Andrea E; Chen, Zhuo; Chen, Wenjing; Liu, Xia; Salomon, Arthur R; Liu, Huiping; Weichselbaum, Ralph R; Yu, Jindan; Peter, Marcus E

2017-03-07

Stimulation of CD95/Fas drives and maintains cancer stem cells (CSCs). We now report that this involves activation of signal transducer and activator of transcription 1 (STAT1) and induction of STAT1-regulated genes and that this process is inhibited by active caspases. STAT1 is enriched in CSCs in cancer cell lines, patient-derived human breast cancer, and CD95 high -expressing glioblastoma neurospheres. CD95 stimulation of cancer cells induced secretion of type I interferons (IFNs) that bind to type I IFN receptors, resulting in activation of Janus-activated kinases, activation of STAT1, and induction of a number of STAT1-regulated genes that are part of a gene signature recently linked to therapy resistance in five primary human cancers. Consequently, we identified type I IFNs as drivers of cancer stemness. Knockdown or knockout of STAT1 resulted in a strongly reduced ability of CD95L or type I IFN to increase cancer stemness. This identifies STAT1 as a key regulator of the CSC-inducing activity of CD95. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Apelin: an endogenous peptide essential for cardiomyogenic differentiation of mesenchymal stem cells via activating extracellular signal-regulated kinase 1/2 and 5.

PubMed

Wang, Li; Zhu, Zhi-Ming; Zhang, Ning-Kun; Fang, Zhi-Rong; Xu, Xiao-Hong; Zheng, Nan; Gao, Lian-Ru

2016-05-01

Growing evidence has shown that apelin/APJ system functions as a critical mediator of cardiac development as well as cardiovascular function. Here, we investigated the role of apelin in the cardiomyogenic differentiation of mesenchymal stem cells derived from Wharton's jelly of human umbilical cord in vitro. In this research, we used RNA interference methodology and gene transfection technique to regulate the expression of apelin in Wharton's jelly-derived mesenchymal stem cells and induced cells with a effective cardiac differentiation protocol including 5-azacytidine and bFGF. Four weeks after induction, induced cells assumed a stick-like morphology and myotube-like structures except apelin-silenced cells and the control group. The silencing expression of apelin in Wharton's jelly-derived mesenchymal stem cells decreased the expression of several critical cardiac progenitor transcription factors (Mesp1, Mef2c, NKX2.5) and cardiac phenotypes (cardiac α-actin, β-MHC, cTnT, and connexin-43). Meanwhile, endogenous compensation of apelin contributed to differentiating into cells with characteristics of cardiomyocytes in vitro. Further experiment showed that exogenous apelin peptide rescued the cardiomyogenic differentiation of apelin-silenced mesenchymal stem cells in the early stage (1-4 days) of induction. Remarkably, our experiment indicated that apelin up-regulated cardiac specific genes in Wharton's jelly-derived mesenchymal stem cells via activating extracellular signal-regulated kinase (ERK) 1/2 and 5. © 2016 International Federation for Cell Biology.

Generation of Mesenchymal-Like Stem Cells From Urine in Pediatric Patients.

PubMed

He, W; Zhu, W; Cao, Q; Shen, Y; Zhou, Q; Yu, P; Liu, X; Ma, J; Li, Y; Hong, K

2016-01-01

Mesenchymal stem cells (MSCs) have been widely used for regenerative medicine. Traditionally, the procedures of MSC isolation are usually invasive and time-consuming. Urine is merely a body waste, and recent studies have suggested that urine represents an alternative source of stem cells. We, therefore, determined whether the possibility of isolating mesenchymal-like stem cells was practical from human urine. A total of 16 urine samples were collected from pediatric patients. Urine-derived cells were isolated, expanded, and identified for specific cell surface markers using flow cytometry. Cell morphology was observed by microscopy. Osteogenic and adipogenic differentiation potential were determinded by culturing cells in specific induction medium, and assessed by alkaline phosphatase and oil red O stainings, respectively. Clones were established and passaged successfully from primary cultures of urine cells. Cultured urine-derived cells at passage 3 were fusiform and arranged with certain directionality. Urine-derived cells at passage 5 displayed expressions of cell surface markers (CD29, CD105, CD166, CD90, and CD13). There was no expression of the general hematopoietic cell markers (CD45, CD34, and HLA-DR). Under in vitro induction conditions, urine-derived cells at passage 5 were able to differentiate into osteoblasts, but not adipocytes. Urine may be a noninvasive source for mesenchymal-like stem cells. These cells could potentially provide a new source of autologous stem cells for regenerative medicine and cell therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

High-temperature responses of North American cacti

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, S.D.; Didden-Zopfy, B.; Nobel, P.S.

1984-04-01

High-temperature tolerances of 14 species of North American cacti were investigated. A reduction in the proportion of chlorenchyma cells taking up a vital stain (neutral red) and reduced nocturnal acid accumulation were used as indicators of high-temperature damage. All species tolerated relatively high tissue temperatures, the mean maximum tolerance being 64/sup 0/C, with an absolute maximum of 69/sup 0/ for two species of ferocactus. Such tissue tolerances to high temperature may be unsurpassed in vascular plants. Morphological features can affect tissue temperatures. Specifically, thin-stemmed species such as the cylindropuntias attain lower maximum temperatures under identical microclimatic conditions than do moremore » massive species; they also tend to be less tolerant of high-temperature stress. Stem diameter changes of three species of columnar ceriod cacti along a Sonoran Desert latitudinal transect were previously attributed to adaptation to progressively colder temperatures northward. Such changes can also be interpreted as a morphological adaptation to high temperatures, particularly in the southern Sonoran Desert. Interspecific differences in high-temperature tolerance may account for distributional differences among other species. Acclimation of high-temperature tolerances in response to increasing day/night air temperatures was observed in all 14 species, especially at higher growh temperatures. From 40/sup 0/ day/30/sup 0/ night to 50/sup 0//40/sup 0/, the tolerable tissue temperatures increased an average of 6/sup 0/. Half-times for the acclimation shifts were 1-3d. Although cacti attain extremely high tissue temperatures in desert habitats, tolerance of high temperatures and pronounced acclimation potential allow them to occur in some of the hottest habitats in North America.« less

5-Azacitidine Monotherapy Followed by Related Haploidentical Hematopoietic Stem Cell Transplantation Achieves Durable Remission in a Pediatric Patient With Acute Undifferentiated Leukemia Refractory to High-Dose Chemotherapy.

PubMed

Polishchuk, Veronika; Khazal, Sajad; Berulava, Giorgi; Roth, Michael; Mahadeo, Kris M

2016-06-01

Patients with acute leukemias of undifferentiated lineage (AUL) generally have guarded prognosis. Here, we describe the first reported pediatric patient with AUL refractory to high-dose chemotherapy who achieved clinical remission with ALL maintenance therapy and 5-azacitidine. His induction remission was followed by consolidation with reduced toxicity haploidentical hematopoietic stem cell transplant (HSCT). At 9 months post-HSCT, the patient is alive and in remission. This combination therapy of remission induction with ALL maintenance therapy and 5-azacitidine and consolidation with reduced toxicity haploidentical HSCT is novel and promising for patients who lack conventional donors and are not candidates for myeloablative therapy. © 2016 Wiley Periodicals, Inc.

Assisted of electromagnetic fields in glucose production from cassava stems

NASA Astrophysics Data System (ADS)

Lismeri, Lia; Haryati, Sri; Djoni Bustan, M.; Darni, Yuli

2018-03-01

Decrease in fossil fuel reserves that led to high price has become major problem in many countries around the world. To acquire the sustainability of energy reserves, the renewable energies obtained from plant biomass will therefore have to play an increasing role in fulfilling energy demand throughout the century. Renewable energy source must be explored by innovative techniques which is safe to the environment and low in energy consumptions. This research conducted to produce glucose from cassava stems assisted by electromagnetic field inductions process. The parameters used in this research were pretreatment solvent, concentration, temperature and electrical currents. The electromagnetic field inductions could be applied to increase glucose productivity with the maximum yield of glucose was 47.43%.

Diabetes Is Reversed in a Murine Model by Marginal Mass Syngeneic Islet Transplantation Using a Subcutaneous Cell Pouch Device

PubMed Central

Pepper, Andrew R.; Pawlick, Rena; Gala-Lopez, Boris; MacGillivary, Amanda; Mazzuca, Delfina M.; White, David J. G.; Toleikis, Philip M.; Shapiro, A. M. James

2015-01-01

Background Islet transplantation is a successful β-cell replacement therapy for selected patients with type 1 diabetes mellitus. Although high rates of early insulin independence are achieved routinely, long-term function wanes over time. Intraportal transplantation is associated with procedural risks, requires multiple donors, and does not afford routine biopsy. Stem cell technologies may require potential for retrievability, and graft removal by hepatectomy is impractical. There is a clear clinical need for an alternative, optimized transplantation site. The subcutaneous space is a potential substitute, but transplantation of islets into this site has routinely failed to reverse diabetes. However, an implanted device, which becomes prevascularized before transplantation, may alter this equation. Methods Syngeneic mouse islets were transplanted subcutaneously within Sernova Corp's Cell Pouch (CP). All recipients were preimplanted with CPs 4 weeks before diabetes induction and transplantation. After transplantation, recipients were monitored for glycemic control and glucose tolerance. Results Mouse islets transplanted into the CP routinely restored glycemic control with modest delay and responded well to glucose challenge, comparable to renal subcapsular islet grafts, despite a marginal islet dose, and normoglycemia was maintained until graft explantation. In contrast, islets transplanted subcutaneously alone failed to engraft. Islets within CPs stained positively for insulin, glucagon, and microvessels. Conclusions The CP is biocompatible, forms an environment suitable for islet engraftment, and offers a potential alternative to the intraportal site for islet and future stem cell therapies. PMID:26308506

A Safety and Tolerability Study of CDX-301 With or Without Plerixafor for Stem Cell Mobilization in Matched Related Allogeneic Donor/Recipient Sibling Transplant Pairs

ClinicalTrials.gov

2017-04-06

For Donors; Related Donors Giving Peripheral Blood Stem Cells (PBSC) to a Sibling; For Recipients; Acute Myelogenous Leukemia (AML); Acute Lymphoblastic Leukemia (ALL); Myelodysplastic Syndrome (MDS); Chronic Myelogenous Leukemia (CML); Non-Hodgkins Lymphoma (NHL); Hodgkins Disease (HD); Chronic Lymphocytic Leukemia (CLL)

Harnessing the Foreign Body Reaction in Marginal Mass Device-less Subcutaneous Islet Transplantation in Mice.

PubMed

Pepper, Andrew R; Pawlick, Rena; Bruni, Antonio; Gala-Lopez, Boris; Wink, John; Rafiei, Yasmin; Bral, Mariusz; Abualhassan, Nasser; Shapiro, A M James

2016-07-01

Islet transplantation is a successful β-cell replacement therapy for selected patients with type 1 diabetes mellitus. However, despite early insulin independence, long-term graft attrition gradually reverts recipients to exogenous insulin dependency. Undoubtedly, as insulin producing stem cell therapies progress, a transplant site that is retrievable is desirable. This prerequisite is currently incompatible with intrahepatic islet transplantation. Herein, we evaluate the functional capacity of a prevascularized subcutaneous site to accommodate marginal islet mass transplantation in mice. Syngeneic mouse islets (150) were transplanted either under the kidney capsule (KC), into a prevascularized subcutaneous device-less (DL) site, or into the unmodified subcutaneous (SC) tissue. The DL site was created 4 weeks before diabetes induction and islet transplantation through the transient placement of a 5-Fr vascular catheter. Recipient mice were monitored for glycemic control and intraperitoneal glucose tolerance. A marginal islet mass transplanted into the DL site routinely reversed diabetes (n = 13 of 18) whereas all SC islet recipients failed to restore glycemic control (n = 0 of 10, P < 0.01, log-rank). As anticipated, nearly all islet-KC mice (n = 15 of 16) became euglycemic posttransplant. The DL recipients' glucose profiles were comparable to KC islet grafts, postintrapertioneal glucose tolerance testing, whereas SC recipients remained hyperglycemic postglucose challenge. All normoglycemic mice maintained graft function for 100 days until graft retrieval. DL and KC islet grafts stained positively for insulin, microvessels, and a collagen scaffold. The device-less prevascularized approach supports marginal mass islet engraftment in mice.

Cytokinin response factor 4 (CRF4) is induced by cold and involved in freezing tolerance.

PubMed

Zwack, Paul J; Compton, Margaret A; Adams, Cami I; Rashotte, Aaron M

2016-03-01

Cytokinin response factor 4 (CRF4) shows a short-term induction by cold (4 °C) that appears to play a role in non-acclimated freezing tolerance as seen in mutant and overexpression lines. Responses to abiotic stresses, such as cold stress, are critical to plant growth and optimal production. Examination of Arabidopsis cytokinin response factors (CRFs) showed transcriptional induction after exposure to cold (4 °C). In particular, CRF4 was strongly induced in both root and shoot tissues. As CRF4 is one of several CRFs not transcriptionally regulated by cytokinin, we further investigated its response to cold. Peak CRF4 induction occurred 6 h post cold exposure, after which expression was maintained at moderately elevated levels during extended cold and subsequent treatment recovery. Examination of CRF4 mutant and overexpression lines under standard (non-cold) conditions revealed little difference from WT. One exception was a small, but significant increase in primary root growth of overexpression plants (CRF4OX). Under cold conditions, the only phenotype observed was a reduction in the rate of germination of CRF4OX seeds. The pattern of CRF4 expression along with the lack of strong phenotype at 4 °C led us to hypothesize that cold induction of CRF4 could play a role in short-term cold acclimation leading to increased freeze tolerance. Examination of CRF4OX and crf4 plants exposed to freezing temperatures revealed mutants lacking expression of CRF4 were more sensitive to freezing, while CRF4OXs with increased levels CRF4 levels were more tolerant. Altered transcript expression of CBF and COR15a cold signaling pathway genes in crf4 mutant and overexpression lines suggest that CRF4 may be potentially connected to this pathway. Overall this indicates that CRF4 plays an important role in both cold response and freezing stress.

Impact of induction regimen and stem cell transplantation on outcomes in double-hit lymphoma: a multicenter retrospective analysis.

PubMed

Petrich, Adam M; Gandhi, Mitul; Jovanovic, Borko; Castillo, Jorge J; Rajguru, Saurabh; Yang, David T; Shah, Khushboo A; Whyman, Jeremy D; Lansigan, Frederick; Hernandez-Ilizaliturri, Francisco J; Lee, Lisa X; Barta, Stefan K; Melinamani, Shruthi; Karmali, Reem; Adeimy, Camille; Smith, Scott; Dalal, Neil; Nabhan, Chadi; Peace, David; Vose, Julie; Evens, Andrew M; Shah, Namrata; Fenske, Timothy S; Zelenetz, Andrew D; Landsburg, Daniel J; Howlett, Christina; Mato, Anthony; Jaglal, Michael; Chavez, Julio C; Tsai, Judy P; Reddy, Nishitha; Li, Shaoying; Handler, Caitlin; Flowers, Christopher R; Cohen, Jonathon B; Blum, Kristie A; Song, Kevin; Sun, Haowei Linda; Press, Oliver; Cassaday, Ryan; Jaso, Jesse; Medeiros, L Jeffrey; Sohani, Aliyah R; Abramson, Jeremy S

2014-10-09

Patients with double-hit lymphoma (DHL), which is characterized by rearrangements of MYC and either BCL2 or BCL6, face poor prognoses. We conducted a retrospective multicenter study of the impact of baseline clinical factors, induction therapy, and stem cell transplant (SCT) on the outcomes of 311 patients with previously untreated DHL. At median follow-up of 23 months, the median progression-free survival (PFS) and overall survival (OS) rates among all patients were 10.9 and 21.9 months, respectively. Forty percent of patients remain disease-free and 49% remain alive at 2 years. Intensive induction was associated with improved PFS, but not OS, and SCT was not associated with improved OS among patients achieving first complete remission (P = .14). By multivariate analysis, advanced stage, central nervous system involvement, leukocytosis, and LDH >3 times the upper limit of normal were associated with higher risk of death. Correcting for these, intensive induction was associated with improved OS. We developed a novel risk score for DHL, which divides patients into high-, intermediate-, and low-risk groups. In conclusion, a subset of DHL patients may be cured, and some patients may benefit from intensive induction. Further investigations into the roles of SCT and novel agents are needed. © 2014 by The American Society of Hematology.

Effect of alterations in metabolic rate on the duration of tolerance in neonatally injected animals.

PubMed

St Rose, J E; Murray, G W; Howe, S A

1976-01-01

Exposure to low environmental temperature caused a decrease in the half-life of human albumin (HA) in rabbits injected with 20 mg HA at birth, and a twofold increase in the proportion of animals which lost their tolerance by 150 days of age. Administration of thyroxin produced an even greater effect with respect to tolerance loss. Simlar mechanisms may be involved in the effects of cold exposure and thyroxin administration on tolerance duration. One possible mecahnism is that the duration of tolerance is dependent upon the metabolic half-life of the tolerance-inducing antigen. An alternative mechanism could be a cold- or thyroxin-induced enhancement of the recruitment of immunologically competent cells from an undifferentiated population of stem cells.

Promotion of stem cell proliferation by vegetable peptone.

PubMed

Lee, J; Lee, J; Hwang, H; Jung, E; Huh, S; Hyun, J; Park, D

2009-10-01

Technical limitations and evolution of therapeutic applications for cell culture-derived products have accelerated elimination of animal-derived constituents from such products to minimize inadvertent introduction of microbial contaminants, such as fungi, bacteria or viruses. The study described here was conducted to investigate the proliferative effect of vegetable peptone on adult stem cells in the absence of serum, and its possible mechanisms of action. Cell viability and proliferation were determined using the MTT assay and Click-iT EdU flow cytometry, respectively. In addition, changes in expression of cytokine genes were analysed using MILLIPLEX human cytokine enzyme-linked immunosorbent assay kit. Viability of cord blood-derived mesenchymal stem cells (CB-MSC) and adipose tissue-derived stem cells (ADSC) increased significantly when treated with the peptone. In addition, median value of the group treated with peptone shifted to the right when compared to the untreated control group. Furthermore, quantitative analysis of the cytokines revealed that production of vascular endothelial growth factor (VEGF), transforming growth factor-beta1 (TGF-beta1), and interleukin-6 (IL-6) increased significantly in response to treatment with our vegetable peptone in both CB-MSCs and ADSCs. Our findings revealed that the vegetable peptone promotes proliferation of CB-MSCs and ADSCs. In addition, results of this study suggest that induction of stem cell proliferation by vegetable peptone is likely to be related to its induction of VEGF, TGF-beta1, and IL-6 expression.

Generation of H1 PAX6WT/EGFP reporter cells to purify PAX6 positive neural stem/progenitor cells.

PubMed

Wu, Wei; Liu, Juli; Su, Zhenghui; Li, Zhonghao; Ma, Ning; Huang, Ke; Zhou, Tiancheng; Wang, Linli

2018-08-25

Neural conversion from human pluripotent cells (hPSCs) is a potential therapy to neurological disease in the future. However, this is still limited by efficiency and stability of existed protocols used for neural induction from hPSCs. To overcome this obstacle, we developed a reporter system to screen PAX6 + neural progenitor/stem cells using transcription activator like effector nuclease (TALEN). We found that knock-in 2 A-EGFP cassette into PAX6 exon of human embryonic stem cells H1 with TALEN-based homology recombination could establish PAX6 WT/EGFP H1 reporter cell line fast and efficiently. This reporter cell line could differentiate into PAX6 and EGFP double positive neural progenitor/stem cells (NPCs/NSCs) after neural induction. Those PAX6 WT/EGFP NPCs could be purified, expanded and specified to post-mitotic neurons in vitro efficiently. With this reporter cell line, we also screened out 1 NPC-specific microRNA, hsa-miR-99a-5p, and 3 ESCs-enriched miRNAs, hsa-miR-302c-5p, hsa-miR-512-3p and hsa-miR-518 b. In conclusion, the TALEN-based neural stem cell screening system is safe and efficient and could help researcher to acquire adequate and pure neural progenitor cells for further application. Copyright © 2018 Elsevier Inc. All rights reserved.

Lead accumulation and tolerance of Moso bamboo (Phyllostachys pubescens) seedlings: applications of phytoremediation*

PubMed Central

Liu, Dan; Li, Song; Islam, Ejazul; Chen, Jun-ren; Wu, Jia-sen; Ye, Zheng-qian; Peng, Dan-li; Yan, Wen-bo; Lu, Kou-ping

2015-01-01

A hydroponics experiment was aimed at identifying the lead (Pb) tolerance and phytoremediation potential of Moso bamboo (Phyllostachys pubescens) seedlings grown under different Pb treatments. Experimental results indicated that at the highest Pb concentration (400 μmol/L), the growth of bamboo seedlings was inhibited and Pb concentrations in leaves, stems, and roots reached the maximum of 148.8, 482.2, and 4282.8 mg/kg, respectively. Scanning electron microscopy revealed that the excessive Pb caused decreased stomatal opening, formation of abundant inclusions in roots, and just a few inclusions in stems. The ultrastructural analysis using transmission electron microscopy revealed that the addition of excessive Pb caused abnormally shaped chloroplasts, disappearance of endoplasmic reticulum, shrinkage of nucleus and nucleolus, and loss of thylakoid membranes. Although ultrastructural analysis revealed some internal damage, even the plants exposed to 400 μmol/L Pb survived and no visual Pb toxicity symptoms such as necrosis and chlorosis were observed in these plants. Even at the highest Pb treatment, no significant difference was observed for the dry weight of stem compared with controls. It is suggested that use of Moso bamboo as an experimental material provides a new perspective for remediation of heavy metal contaminated soil owing to its high metal tolerance and greater biomass. PMID:25644467

Suppression of HLA Expression by Lentivirus-mediated Gene Transfer of siRNA Cassettes and In Vivo Chemoselection to Enhance Hematopoietic Stem Cell Transplantation

PubMed Central

Hacke, Katrin; Falahati, Rustom; Flebbe-Rehwaldt, Linda; Kasahara, Noriyuki; Gaensler, Karin M. L.

2010-01-01

Current approaches for hematopoietic stem cell (HSC) and organ transplantation are limited by donor and host-mediated immune responses to allo-antigens. Application of these therapies is limited by the toxicity of preparative and post-transplant immunosuppressive regimens and a shortage of appropriate HLA-matched donors. We have been exploring two complementary approaches for genetically modifying donor cells that achieve long-term suppression of cellular proteins that elicit host immune responses to mismatched donor antigens, and provide a selective advantage to genetically engineered donor cells after transplantation. The first approach is based on recent advances that make feasible targeted down-regulation of HLA expression. Suppression of HLA expression could help to overcome limitations imposed by extensive HLA polymorphisms that restrict the availability of suitable donors. Accordingly, we have recently investigated whether knockdown of HLA by RNA interference (RNAi) enables allogeneic cells to evade immune recognition. For efficient and stable delivery of short hairpin-type RNAi constructs (shRNA), we employed lentivirus-based gene transfer vectors that integrate into genomic DNA, thereby permanently modifying transduced donor cells. Lentivirus-mediated delivery of shRNA targeting pan-Class I and allele-specific HLA achieved efficient and dose-dependent reduction in surface expression of HLA in human cells, and enhanced resistance to allo-reactive T lymphocyte-mediated cytotoxicity, while avoiding non-MHC restricted killing. Complementary strategies for genetic engineering of HSC that would provide a selective advantage for transplanted donor cells and enable successful engraftment with less toxic preparative and immunosuppressive regimens would increase the numbers of individuals to whom HLA suppression therapy could be offered. Our second strategy is to provide a mechanism for in vivo selection of genetically modified HSC and other donor cells. We have uniquely combined transplantation during the neonatal period, when tolerance may be more readily achieved, with a positive selection strategy for in vivo amplification of drug-resistant donor HSC. This model system enables the evaluation of mechanisms of tolerance induction to neo-antigens, and allogeneic stem cells during immune ontogeny. HSC are transduced ex vivo by lentivirus-mediated gene transfer of P140K-O6-methylguanine-methyltransferase (MGMTP140K). The MGMTP140K DNA repair enzyme confers resistance to benzylguanine, an inhibitor of endogenous MGMT, and to chloroethylating agents such as BCNU. In vivo chemoselection enables enrichment of donor cells at the stem cell level. Using complementary approaches of in vivo chemoselection and RNAi-induced silencing of HLA expression may enable the generation of histocompatibility-enhanced, and eventually, perhaps “universally” compatible cellular grafts. PMID:19048410

Melatonin induction and its role in high light stress tolerance in Arabidopsis thaliana.

PubMed

Lee, Hyoung Yool; Back, Kyoungwhan

2018-05-16

In plants, melatonin is a potent bioactive molecule involved in the response against various biotic and abiotic stresses. However, little is known of its defensive role against high light (HL) stress. In this study, we found that melatonin was transiently induced in response to HL stress in Arabidopsis thaliana with a simultaneous increase in the expression of melatonin biosynthetic genes, including serotonin N-acetyltransferase1 (SNAT1). Transient induction of melatonin was also observed in the flu mutant, a singlet oxygen ( 1 O 2 )-producing mutant, upon light exposure, suggestive of melatonin induction by chloroplastidic 1 O 2 against HL stress. An Arabidopsis snat1 mutant was devoid of melatonin induction upon HL stress, resulting in high susceptibility to HL stress. Exogenous melatonin treatment mitigated damage caused by HL stress in the snat1 mutant by reducing O 2 - production and increasing the expression of various ROS-responsive genes. In analogy, an Arabidopsis SNAT1-overexpressing line showed increased tolerance of HL stress concomitant with a reduction in malondialdehyde and ion leakage. A complementation line expressing an Arabidopsis SNAT1 genomic fragment in the snat1 mutant completely restored HL stress susceptibility in the snat1 mutant to levels comparable to that of wild-type Col-0 plants. The results of the analysis of several Arabidopsis genetic lines reveal for the first time at the genetic level that melatonin is involved in conferring HL stress tolerance in plants. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Limited hair cell induction from human induced pluripotent stem cells using a simple stepwise method.

PubMed

Ohnishi, Hiroe; Skerleva, Desislava; Kitajiri, Shin-ichiro; Sakamoto, Tatsunori; Yamamoto, Norio; Ito, Juichi; Nakagawa, Takayuki

2015-07-10

Disease-specific induced pluripotent stem cells (iPS) cells are expected to contribute to exploring useful tools for studying the pathophysiology of inner ear diseases and to drug discovery for treating inner ear diseases. For this purpose, stable induction methods for the differentiation of human iPS cells into inner ear hair cells are required. In the present study, we examined the efficacy of a simple induction method for inducing the differentiation of human iPS cells into hair cells. The induction of inner ear hair cell-like cells was performed using a stepwise method mimicking inner ear development. Human iPS cells were sequentially transformed into the preplacodal ectoderm, otic placode, and hair cell-like cells. As a first step, preplacodal ectoderm induction, human iPS cells were seeded on a Matrigel-coated plate and cultured in a serum free N2/B27 medium for 8 days according to a previous study that demonstrated spontaneous differentiation of human ES cells into the preplacodal ectoderm. As the second step, the cells after preplacodal ectoderm induction were treated with basic fibroblast growth factor (bFGF) for induction of differentiation into otic-placode-like cells for 15 days. As the final step, cultured cells were incubated in a serum free medium containing Matrigel for 48 days. After preplacodal ectoderm induction, over 90% of cultured cells expressed the genes that express in preplacodal ectoderm. By culture with bFGF, otic placode marker-positive cells were obtained, although their number was limited. Further 48-day culture in serum free media resulted in the induction of hair cell-like cells, which expressed a hair cell marker and had stereocilia bundle-like constructions on their apical surface. Our results indicate that hair cell-like cells are induced from human iPS cells using a simple stepwise method with only bFGF, without the use of xenogeneic cells. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Induction of Phytoalexins in Seabrook Sea Island, Pima S-7 and Pima S-6 Cottons after Inoculation with Fusarium oxysporum f. sp. vasinfectum Race-4

USDA-ARS?s Scientific Manuscript database

In 2002, a strain of Fusarium oxysporum f. sp. vasinfectum was found in California cotton fields and identified as race 4. Stem inoculations with isolates of the California strain (CA Fov-4) do not elicit symptoms in controlled-environmental chamber experiments, while stem inoculations with Fov rac...

Time-Dependent Effect of Encapsulating Alginate Hydrogel on Neurogenic Potential

PubMed Central

Razavi, Shahnaz; Khosravizadeh, Zahra; Bahramian, Hamid; Kazemi, Mohammad

2015-01-01

Objective Due to the restricted potential of neural stem cells for regeneration of central nervous system (CNS) after injury, providing an alternative source for neural stem cells is essential. Adipose derived stem cells (ADSCs) are multipotent cells with properties suitable for tissue engineering. In addition, alginate hydrogel is a biocompatible polysaccharide polymer that has been used to encapsulate many types of cells. The aim of this study was to assess the proliferation rate and level of expression of neural markers; NESTIN, glial fibrillary acidic protein (GFAP) and microtubule-associated protein 2 (MAP2) in encapsulated human ADSCs (hADSCs) 10 and14 days after neural induction. Materials and Methods In this experimental study, ADSCs isolated from human were cultured in neural induction media and seeded into alginate hydrogel. The rate of proliferation and differentiation of encapsulated cells were evaluated by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) assay, immunocytoflourescent and realtime reverse transcriptase polymerase chain reaction (RT-PCR) analyzes 10 and 14 days after induction. Results The rate of proliferation of encapsulated cells was not significantly changed with time passage. The expression of NESTIN and GFAP significantly decreased on day 14 relative to day 10 (P<0.001) but MAP2 expression was increased. Conclusion Alginate hydrogel can promote the neural differentiation of encapsulated hADSCs with time passage. PMID:26199909

Induction of quiescence (G0) in bone marrow stromal stem cells enhances their stem cell characteristics.

PubMed

Rumman, Mohammad; Majumder, Abhijit; Harkness, Linda; Venugopal, Balu; Vinay, M B; Pillai, Malini S; Kassem, Moustapha; Dhawan, Jyotsna

2018-05-17

Several studies have suggested that bone marrow stromal steam cells (BMSC) exist in a quiescent state (G0) within the in vivo niche; however, an explicit analysis of the biology of G0 state-BMSC has not been reported. We hypothesized that induction of G0 in BMSC might enhance their stem cell properties. Thus, we induced quiescence in BMSC in vitro by (a) suspension culture in a viscous medium or (b) culture on soft polyacrylamide substrate; and examined their molecular and functional phenotype. Induction of G0 was confirmed by bromo-deoxyuridine (BrdU) labelling and analysis of cell cycle gene expression. Upon reactivation and re-entry into cell cycle, G0 state-BMSC exhibited enhanced clonogenic self-renewal, preferential differentiation into osteoblastic rather than adipocytic cells and increased ectopic bone formation when implanted subcutaneously in vivo in immune-deficient mice, compared to asynchronous proliferating (pre-G0) BMSC. Global gene expression profiling revealed reprogramming of the transcriptome during G0 state including significant alterations in relevant pathways and expression of secreted factors, suggesting altered autocrine and paracrine signaling by G0 state-BMSC and a possible mechanism for enhanced bone formation. G0 state-BMSC might provide a clinically relevant model for understanding the in vivo biology of BMSC. Copyright © 2018. Published by Elsevier B.V.

Endocrine disrupting chemicals affect the adipogenic differentiation of mesenchymal stem cells in distinct ontogenetic windows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biemann, Ronald, E-mail: ronald.biemann@medizin.uni-halle.de; Navarrete Santos, Anne; Navarrete Santos, Alexander

Highlights: Black-Right-Pointing-Pointer Endocrine disrupting chemicals affect adipogenesis in mesenchymal stem cells (MSC). Black-Right-Pointing-Pointer The adipogenic impact depends strongly on the window of exposure. Black-Right-Pointing-Pointer Bisphenol A reduces the potential of MSC to differentiate into adipocytes. Black-Right-Pointing-Pointer DEHP and TBT trigger the adipogenic differentiation of mesenchymal stem cells. Black-Right-Pointing-Pointer BPA, DEHP and TBT did not affect adipogenesis in embryonic stem cells. -- Abstract: Endocrine disrupting chemicals (EDC) like bisphenol A (BPA), bis(2-ethylhexyl)phthalate (DEHP) and tributyltin (TBT) are ubiquitously present in the environment and in human tissues. They bind to nuclear hormone receptors and affect cellular and developmental processes. In this study,more » we show that BPA, DEHP and TBT affect the adipogenic differentiation of murine mesenchymal stem cells (MSC, C3H/10T1/2) in a concentration-, stage- and compound-specific manner. C3H/10T1/2 cells and embryonic stem cells (CGR8) were exposed to BPA, DEHP or TBT at different stages of cell determination and differentiation (undifferentiated growth, adipogenic induction and terminal adipogenic differentiation). The final amount of differentiated adipocytes, cellular triglyceride content and mRNA expression of adipogenic marker genes (adiponectin, FABP4, PPAR{gamma}2, LPL) were quantified and compared with corresponding unexposed cells. BPA (10 {mu}M) decreased subsequent adipogenic differentiation of MSC, when cells were exposed during undifferentiated growth. In contrast, DEHP (100 {mu}M) during the hormonal induction period, and TBT (100 nM) in all investigated stages, enhanced adipogenesis. Importantly, exposure of undifferentiated murine embryonic stem cells did not show any effect of the investigated EDC on subsequent adipogenic differentiation.« less

Specific oral tolerance induction with raw hen's egg in children with very severe egg allergy: a randomized controlled trial.

PubMed

Dello Iacono, Iride; Tripodi, Salvatore; Calvani, Mauro; Panetta, Valentina; Verga, Maria Carmela; Miceli Sopo, Stefano

2013-02-01

Treatment of severe egg allergy is avoidance of hen's egg (HE) and carrying self-injectable epinephrine. Specific oral tolerance induction (SOTI) seems a promising alternative treatment. However, some aspects of SOTI are still considered experimental. We evaluated the efficacy and safety of an original 6-month SOTI protocol in children with very severe HE allergy using raw HE emulsion. Twenty children (age range: 5-11 yr) were randomized equally into a SOTI treatment group and a control group. The treatment group started SOTI and underwent a second challenge 6 months later. Control children were kept on an egg-free diet for 6 months and then underwent a second challenge. After 6 months, 9/10 children of the SOTI group (90%) achieved partial tolerance (at least 10 ml, but <40 ml of raw HE emulsion, in a single dose) and 1 (10%) was able to tolerate only 5 ml (no tolerance). After 6 months, nine control children tested positive to the second challenge at a dose ≤0.9 ml of raw HE emulsion, and one reacted to 1.8 ml (SOTI vs. control group p<0.0001). All children in the SOTI group had side effects, but no child had a grade 5 reaction according to the Sampson grading. Six months of SOTI with raw HE emulsion resulted in partial tolerance, with regular intake, in a significant percentage of children with severe egg allergy. © 2012 John Wiley & Sons A/S.

Early and progressive insulin resistance in young, non-obese cancer survivors treated with hematopoietic stem cell transplantation.

PubMed

Bizzarri, Carla; Pinto, Rita M; Ciccone, Sara; Brescia, Letizia P; Locatelli, Franco; Cappa, Marco

2015-09-01

It is unclear whether there is a causative relationship between the development of metabolic syndrome (MS) and increased risk of early cardiovascular morbidity in patients receiving hematopoietic stem cell transplantation (HSCT) during childhood. Early identification of risk factors associated with insulin resistance, MS, and abnormal glucose tolerance during childhood or adolescence in these patients could represent a useful tool for preventing cardiovascular disorders. In a single-center, prospective, descriptive, cross-sectional study, we studied 45 survivors of hematological malignancies (age: 13.9 ± 4.8 years) treated with HSCT before the age of 18 years and 90 matched healthy controls. We collected clinical, imaging, and laboratory data including oral glucose tolerance test (OGTT). 7/45 patients (15.6%) showed abnormal glucose tolerance at OGTT, 1/45 (2.2%) was obese, and none fulfilled the criteria for MS. A waist/height ratio >0.5 was associated with patients with abnormal glucose tolerance (85.7% of cases), compared to patients with normal glucose tolerance (42.1%) and controls (23.3%). In patients with abnormal glucose tolerance, use of total body irradiation (TBI) as conditioning regimen was more common, and time elapsed from HSCT was longer. Patients treated with HSCT may develop insulin resistance early after transplantation. They do not show overt obesity, but have redistribution of fat tissue with central fat accumulation. The main factors associated with increased metabolic risk are TBI and time from HSCT. Evaluation of MS and glucose tolerance should be part of hormonal follow-up, which should be routinely proposed to these patients. © 2015 Wiley Periodicals, Inc.

Cadmium (Cd) Localization in Tissues of Cotton (Gossypium hirsutum L.), and Its Phytoremediation Potential for Cd-Contaminated Soils.

PubMed

Chen, Zhifan; Zhao, Ye; Fan, Lidong; Xing, Liteng; Yang, Yujie

2015-12-01

Phytoremediation using economically valuable, large biomass, non-edible plants is a promising method for metal-contaminated soils. This study investigated cotton's tolerance for Cd and remediation potential through analyzing Cd bioaccumulation and localization in plant organs under different soil Cd levels. Results showed cotton presents good tolerance when soil Cd concentration ≤20.26 mg kg(-1). Cotton had good Cd accumulation ability under low soil Cd levels (<1.26 mg kg(-1)), with a TF value (the ratio of Cd concentration in stem to root) above 1. Energy dispersive X-ray microanalysis indicated cotton leaf transpiration played a key role in extracting soil Cd, while roots and stems were the main compartments of Cd storage. Cd complexation to other organic constituents in root and stem cell sap could be a primary detoxifying strategy. Therefore, cotton is a potential candidate for phytoremediation of Cd-contaminated soils.

Transplantation of neurons derived from human iPS cells cultured on collagen matrix into guinea-pig cochleae.

PubMed

Ishikawa, Masaaki; Ohnishi, Hiroe; Skerleva, Desislava; Sakamoto, Tatsunori; Yamamoto, Norio; Hotta, Akitsu; Ito, Juichi; Nakagawa, Takayuki

2017-06-01

The present study examined the efficacy of a neural induction method for human induced pluripotent stem (iPS) cells to eliminate undifferentiated cells and to determine the feasibility of transplanting neurally induced cells into guinea-pig cochleae for replacement of spiral ganglion neurons (SGNs). A stepwise method for differentiation of human iPS cells into neurons was used. First, a neural induction method was established on Matrigel-coated plates; characteristics of cell populations at each differentiation step were assessed. Second, neural stem cells were differentiated into neurons on a three-dimensional (3D) collagen matrix, using the same protocol of culture on Matrigel-coated plates; neuron subtypes in differentiated cells on a 3D collagen matrix were examined. Then, human iPS cell-derived neurons cultured on a 3D collagen matrix were transplanted into intact guinea-pig cochleae, followed by histological analysis. In vitro analyses revealed successful induction of neural stem cells from human iPS cells, with no retention of undifferentiated cells expressing OCT3/4. After the neural differentiation of neural stem cells, approximately 70% of cells expressed a neuronal marker, 90% of which were positive for vesicular glutamate transporter 1 (VGLUT1). The expression pattern of neuron subtypes in differentiated cells on a 3D collagen matrix was identical to that of the differentiated cells on Matrigel-coated plates. In addition, the survival of transplant-derived neurons was achieved when inflammatory responses were appropriately controlled. Our preparation method for human iPS cell-derived neurons efficiently eliminated undifferentiated cells and contributed to the settlement of transplant-derived neurons expressing VGLUT1 in guinea-pig cochleae. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Morphological Analysis of Live Undifferentiated Cells Derived from Induced Pluripotent Stem Cells.

PubMed

Osawa, Yukihiko; Miyamoto, Tomoyuki; Ohno, Setsuyo; Ohno, Eiji

2018-01-01

Induced pluripotent stem (iPS) cells possess pluripotency and self-renewal ability. Therefore, iPS cells are expected to be useful in regenerative medicine. However, iPS cells form malignant immature teratomas after transplantation into animals, even after differentiation induction. It has been suggested that undifferentiated cells expressing Nanog that remain after differentiation induction are responsible for teratoma formation. Various methods of removing these undifferentiated cells have therefore been investigated, but few methods involve morphological approaches, which may induce less cell damage. In addition, for cells derived from iPS cells to be applied in regenerative medicine, they must be alive. However, detailed morphological analysis of live undifferentiated cells has not been performed. For the above reasons, we assessed the morphological features of live undifferentiated cells remaining after differentiation induction as a basic investigation into the clinical application of iPS cells. As a result, live undifferentiated cells remaining after differentiation induction exhibited a round or oval cytoplasm about 12 μm in diameter and a nucleus. They exhibited nucleo-cytoplasmic (N/C) ratio of about 60% and eccentric nuclei, and they possessed partially granule-like structures in the cytoplasm and prominent nucleoli. Although they were similar to iPS cells, they were smaller than live iPS cells. Furthermore, very small cells were present among undifferentiated cells after differentiation induction. These results suggest that the removal of undifferentiated cells may be possible using the morphological features of live iPS cells and undifferentiated cells after differentiation induction. In addition, this study supports safe regenerative medicine using iPS cells.

Tumor-associated mesenchymal stem-like cells provide extracellular signaling cue for invasiveness of glioblastoma cells

PubMed Central

Yoo, Ki-Chun; Lee, Ji-Hyun; Kim, In-Gyu; Kim, Min-Jung; Chang, Jong Hee; Kang, Seok-Gu; Lee, Su-Jae

2017-01-01

Hyaluronic acid (HA) is abundant in tumor microenvironment and closely associated with invasiveness of glioblastoma (GBM) cells. However, the cellular mechanism underlying HA-rich microenvironment in GBM remains unexplored. Here, we show that tumor-associated mesenchymal stem-like cells (tMSLCs) contribute to abundance of hyaluronic acid (HA) in tumor microenvironment through HA synthase-2 (HAS2) induction, and thereby enhances invasiveness of GBM cells. In an autocrine manner, C5a secreted by tMSLCs activated ERK MAPK for HAS2 induction in tMSLCs. Importantly, HA acted as a signaling ligand of its cognate receptor RHAMM for intracellular signaling activation underlying invasiveness of GBM cells. Taken together, our study suggests that tMSLCs contribute to HA-rich proinvasive ECM microenvironment in GBM. PMID:27903965

Mesenchymal-epithelial interactions during hair follicle morphogenesis and cycling

PubMed Central

Sennett, Rachel; Rendl, Michael

2012-01-01

Embryonic hair follicle induction and formation are regulated by mesenchymal-epithelial interactions between specialized dermal cells and epidermal stem cells that switch to a hair fate. Similarly, during postnatal hair growth, communication between mesenchymal dermal papilla cells and surrounding epithelial matrix cells coordinates hair shaft production. Adult hair follicle regeneration in the hair cycle again is thought to be controlled by activating signals originating from the mesenchymal compartment and acting on hair follicle stem cells. Although many signaling pathways are implicated in hair follicle formation and growth, the precise nature, timing, and intersection of these inductive and regulatory signals remains elusive. The goal of this review is to summarize our current understanding and to discuss recent new insights into mesenchymal-epithelial interactions during hair follicle morphogenesis and cycling. PMID:22960356

Postdoctoral Fellow | Center for Cancer Research

Cancer.gov

Seeking highly motivated postdoctoral fellows to study the biology of graft-versus-host disease and mechanisms of its prevention and tolerance induction after allogeneic hematopoietic cell transplantation.

Laterally confined growth of cells induces nuclear reprogramming in the absence of exogenous biochemical factors.

PubMed

Roy, Bibhas; Venkatachalapathy, Saradha; Ratna, Prasuna; Wang, Yejun; Jokhun, Doorgesh Sharma; Nagarajan, Mallika; Shivashankar, G V

2018-05-22

Cells in tissues undergo transdifferentiation programs when stimulated by specific mechanical and biochemical signals. While seminal studies have demonstrated that exogenous biochemical factors can reprogram somatic cells into pluripotent stem cells, the critical roles played by mechanical signals in such reprogramming process have not been well documented. In this paper, we show that laterally confined growth of fibroblasts on micropatterned substrates induces nuclear reprogramming with high efficiency in the absence of any exogenous reprogramming factors. We provide compelling evidence on the induction of stem cell-like properties using alkaline phosphatase assays and expression of pluripotent markers. Early onset of reprogramming was accompanied with enhanced nuclear dynamics and changes in chromosome intermingling degrees, potentially facilitating rewiring of the genome. Time-lapse analysis of promoter occupancy by immunoprecipitation of H3K9Ac chromatin fragments revealed that epithelial, proliferative, and reprogramming gene promoters were progressively acetylated, while mesenchymal promoters were deacetylated by 10 days. Consistently, RNA sequencing analysis showed a systematic progression from mesenchymal to stem cell transcriptome, highlighting pathways involving mechanisms underlying nuclear reprogramming. We then demonstrated that these mechanically reprogrammed cells could be maintained as stem cells and can be redifferentiated into multiple lineages with high efficiency. Importantly, we also demonstrate the induction of cancer stemness properties in MCF7 cells grown in such laterally confined conditions. Collectively, our results highlight an important generic property of somatic cells that, when grown in laterally confined conditions, acquire stemness. Such mechanical reprogramming of somatic cells demonstrated here has important implications in tissue regeneration and disease models. Copyright © 2018 the Author(s). Published by PNAS.

Upper gastrointestinal carcinogenesis: H. pylori and stem cell cross-talk.

PubMed

Pilpilidis, Ioannis; Kountouras, Jannis; Zavos, Christos; Katsinelos, Panagiotis

2011-04-01

Chronic inflammation of the gastric epithelium has been associated with the pathogenesis of gastric cancer, as it was postulated by Corea's model of gastric carcinogenesis. Helicobacter pylori (Hp) regulates this inflammatory process and promotes gastric carcinogenesis through induction of gene mutations and protein modulation. Recent data raise the cancer stem cell hypothesis, which implies a central role of multipotent cancer cells in oncogenesis of various solid tumors. This review provides a synopsis of gastric cancer initiation and promotion through Hp and stem cell signaling pathways. The expanding research field of Hp-related cancer stem cell biology may offer novel implications for future treatment of upper gastrointestinal cancer. Copyright © 2011 Elsevier Inc. All rights reserved.

Induction of pluripotent stem cells from fibroblast cultures.

PubMed

Takahashi, Kazutoshi; Okita, Keisuke; Nakagawa, Masato; Yamanaka, Shinya

2007-01-01

Clinical application of embryonic stem (ES) cells faces difficulties regarding use of embryos, as well as tissue rejection after implantation. One way to circumvent these issues is to generate pluripotent stem cells directly from somatic cells. Somatic cells can be reprogrammed to an embryonic-like state by the injection of a nucleus into an enucleated oocyte or by fusion with ES cells. However, little is known about the mechanisms underlying these processes. We have recently shown that the combination of four transcription factors can generate ES-like pluripotent stem cells directly from mouse fibroblast cultures. The cells, named induced pluripotent stem (iPS) cells, can be differentiated into three germ layers and committed to chimeric mice. Here we describe detailed methods and tips for the generation of iPS cells.

Directing the osteoblastic and chondrocytic differentiations of mesenchymal stem cells: matrix vs. induction media

PubMed Central

He, Jing; Guo, Jianglong; Jiang, Bo; Yao, Ruijuan; Wu, Yao

2017-01-01

Abstract While both induction culture media and matrix have been reported to regulate the stem cell fate, little is known about which factor plays a more decisive role in directing the MSC differentiation lineage as well as the underlying mechanisms. To this aim, we seeded MSCs on HA-collagen and HA-synthetic hydrogel matrixes, which had demonstrated highly different potentials toward osteoblastic and chondrocytic differentiation lineages, respectively, and cultured them with osteogenic, chondrogenic and normal culture media, respectively. A systematic comparison has been carried out on the effects of induction media and matrix on MSC adhesion, cytoskeleton organization, proliferation, and in particular differentiation into the osteoblastic and chondrocytic lineages. The results demonstrated that the matrix selection had a much more profound effect on directing the differentiation lineage than the induction media did. The strong modulation effect on the transcription activities might be the critical factor contributing to the above observations in our study, where canonical Wnt-β-Catenin signal pathway was directly involved in the matrix-driven osteoblastic differentiation. Such findings not only provide a critical insight on natural cellular events leading to the osteoblastic and chondrocytic differentiations, but also have important implications in biomaterial design for tissue engineering applications. PMID:29026640

Activation of PAF-synthesizing enzymes in rat brain stem slices after LTP induction in the medial vestibular nuclei.

PubMed

Francescangeli, Ermelinda; Grassi, Silvarosa; Pettorossi, Vito E; Goracci, Gianfrancesco

2002-11-01

LysoPAF acetyltransferase (lysoPAF-AT) and PAF-synthesizing phosphocholinetransferase (PAF-PCT) are the two enzymes which catalyze the final reactions for the synthesis of PAF. Their activities, assayed in the homogenate of rat brain stem slices and under their optimal conditions, increased 5 min after high frequency stimulation of vestibular afferents, inducing LTP in the medial vestibular nuclei. The activity of phosphatidylcholine-synthesizing phosphocholinetransferase, was not affected. Sixty minutes from the induction of LTP, PAF-PCT activity, but not that of lysoPAF-AT, was still significantly higher with respect to 5 min test stimulated control. We used AP-5 to verify whether this increase was strictly dependent upon LTP induction, which requires NMDA receptor activation. In AP-5 treated slices, lysoPAF-acetyltransferase and PAF-synthesizing phosphocholinetransferase activities increased, but they were reduced after high frequency stimulation under AP-5. In conclusion, we have demonstrated that the activities of PAF-synthesizing enzymes are activated soon after the induction of LTP and that this effect is linked to the activation of NMDA-receptors. We suggest that the enzyme activation by AP-5, preventing LTP, might be due to glutamate enhancement but, in neurons showing LTP and under normal conditions, the activation of potentiation mechanisms is critical for the enhancement of enzyme activities.

Cholinergic and dopaminergic neuronal differentiation of human adipose tissue derived mesenchymal stem cells.

PubMed

Marei, Hany El Sayed; El-Gamal, Aya; Althani, Asma; Afifi, Nahla; Abd-Elmaksoud, Ahmed; Farag, Amany; Cenciarelli, Carlo; Thomas, Caceci; Anwarul, Hasan

2018-02-01

Mesenchymal stem cells (MSCs) are multipotent cells that can differentiate into various cell types such as cartilage, bone, and fat cells. Recent studies have shown that induction of MSCs in vitro by growth factors including epidermal growth factor (EGF) and fibroblast growth factor (FGF2) causes them to differentiate into neural like cells. These cultures also express ChAT, a cholinergic marker; and TH, a dopaminergic marker for neural cells. To establish a protocol with maximum differentiation potential, we examined MSCs under three experimental culture conditions using neural induction media containing FGF2, EGF, BMP-9, retinoic acid, and heparin. Adipose-derived MSCs were extracted and expanded in vitro for 3 passages after reaching >80% confluency, for a total duration of 9 days. Cells were then characterized by flow cytometry for CD markers as CD44 positive and CD45 negative. MSCs were then treated with neural induction media and were characterized by morphological changes and Q-PCR. Differentiated MSCs expressed markers for immature and mature neurons; β Tubulin III (TUBB3) and MAP2, respectively, showing the neural potential of these cells to differentiate into functional neurons. Improved protocols for MSCs induction will facilitate and ensure the reproducibility and standard production of MSCs for therapeutic applications in neurodegenerative diseases. © 2017 Wiley Periodicals, Inc.

Hyperspectral imaging to identify salt-tolerant wheat lines

NASA Astrophysics Data System (ADS)

Moghimi, Ali; Yang, Ce; Miller, Marisa E.; Kianian, Shahryar; Marchetto, Peter

2017-05-01

In order to address the worldwide growing demand for food, agriculture is facing certain challenges and limitations. One of the important threats limiting crop productivity is salinity. Identifying salt tolerate varieties is crucial to mitigate the negative effects of this abiotic stress in agricultural production systems. Traditional measurement methods of this stress, such as biomass retention, are labor intensive, environmentally influenced, and often poorly correlated to salinity stress alone. In this study, hyperspectral imaging, as a non-destructive and rapid method, was utilized to expedite the process of identifying relatively the most salt tolerant line among four wheat lines including Triticum aestivum var. Kharchia, T. aestivum var. Chinese Spring, (Ae. columnaris) T. aestivum var. Chinese Spring, and (Ae. speltoides) T. aestivum var. Chinese Spring. To examine the possibility of early detection of a salt tolerant line, image acquisition was started one day after stress induction and continued on three, seven, and 12 days after adding salt. Simplex volume maximization (SiVM) method was deployed to detect superior wheat lines in response to salt stress. The results of analyzing images taken as soon as one day after salt induction revealed that Kharchia and (columnaris)Chinese Spring are the most tolerant wheat lines, while (speltoides) Chinese Spring was a moderately susceptible, and Chinese Spring was a relatively susceptible line to salt stress. These results were confirmed with the measuring biomass performed several weeks later.

PD-L1–Driven Tolerance Protects Neurogenin3-Induced Islet Neogenesis to Reverse Established Type 1 Diabetes in NOD Mice

PubMed Central

Li, Rongying; Lee, Jeongkyung; Kim, Mi-sun; Liu, Victoria; Moulik, Mousumi; Li, Haiyan; Yi, Qing; Xie, Aini; Chen, Wenhao; Yang, Lina; Li, Yimin; Tsai, Tsung Huang; Oka, Kazuhiro

2015-01-01

A breakdown in self-tolerance underlies autoimmune destruction of β-cells and type 1 diabetes. A cure by restoring β-cell mass is limited by the availability of transplantable β-cells and the need for chronic immunosuppression. Evidence indicates that inhibiting costimulation through the PD-1/PD-L1 pathway is central to immune tolerance. We therefore tested whether induction of islet neogenesis in the liver, protected by PD-L1–driven tolerance, reverses diabetes in NOD mice. We demonstrated a robust induction of neo-islets in the liver of diabetic NOD mice by gene transfer of Neurogenin3, the islet-defining factor, along with betacellulin, an islet growth factor. These neo-islets expressed all the major pancreatic hormones and transcription factors. However, an enduring restoration of glucose-stimulated insulin secretion and euglycemia occurs only when tolerance is also induced by the targeted overexpression of PD-L1 in the neo-islets, which results in inhibition of proliferation and increased apoptosis of infiltrating CD4+ T cells. Further analysis revealed an inhibition of cytokine production from lymphocytes isolated from the liver but not from the spleen of treated mice, indicating that treatment did not result in generalized immunosuppression. This treatment strategy leads to persistence of functional neo-islets that resist autoimmune destruction and consequently an enduring reversal of diabetes in NOD mice. PMID:25332429

Label-free nonlinear optical microscopy detects early markers for osteogenic differentiation of human stem cells.

PubMed

Hofemeier, Arne D; Hachmeister, Henning; Pilger, Christian; Schürmann, Matthias; Greiner, Johannes F W; Nolte, Lena; Sudhoff, Holger; Kaltschmidt, Christian; Huser, Thomas; Kaltschmidt, Barbara

2016-05-26

Tissue engineering by stem cell differentiation is a novel treatment option for bone regeneration. Most approaches for the detection of osteogenic differentiation are invasive or destructive and not compatible with live cell analysis. Here, non-destructive and label-free approaches of Raman spectroscopy, coherent anti-Stokes Raman scattering (CARS) and second harmonic generation (SHG) microscopy were used to detect and image osteogenic differentiation of human neural crest-derived inferior turbinate stem cells (ITSCs). Combined CARS and SHG microscopy was able to detect markers of osteogenesis within 14 days after osteogenic induction. This process increased during continued differentiation. Furthermore, Raman spectroscopy showed significant increases of the PO4(3-) symmetric stretch vibrations at 959 cm(-1) assigned to calcium hydroxyapatite between days 14 and 21. Additionally, CARS microscopy was able to image calcium hydroxyapatite deposits within 14 days following osteogenic induction, which was confirmed by Alizarin Red-Staining and RT- PCR. Taken together, the multimodal label-free analysis methods Raman spectroscopy, CARS and SHG microscopy can monitor osteogenic differentiation of adult human stem cells into osteoblasts with high sensitivity and spatial resolution in three dimensions. Our findings suggest a great potential of these optical detection methods for clinical applications including in vivo observation of bone tissue-implant-interfaces or disease diagnosis.

Label-free nonlinear optical microscopy detects early markers for osteogenic differentiation of human stem cells

NASA Astrophysics Data System (ADS)

Hofemeier, Arne D.; Hachmeister, Henning; Pilger, Christian; Schürmann, Matthias; Greiner, Johannes F. W.; Nolte, Lena; Sudhoff, Holger; Kaltschmidt, Christian; Huser, Thomas; Kaltschmidt, Barbara

2016-05-01

Tissue engineering by stem cell differentiation is a novel treatment option for bone regeneration. Most approaches for the detection of osteogenic differentiation are invasive or destructive and not compatible with live cell analysis. Here, non-destructive and label-free approaches of Raman spectroscopy, coherent anti-Stokes Raman scattering (CARS) and second harmonic generation (SHG) microscopy were used to detect and image osteogenic differentiation of human neural crest-derived inferior turbinate stem cells (ITSCs). Combined CARS and SHG microscopy was able to detect markers of osteogenesis within 14 days after osteogenic induction. This process increased during continued differentiation. Furthermore, Raman spectroscopy showed significant increases of the PO43- symmetric stretch vibrations at 959 cm-1 assigned to calcium hydroxyapatite between days 14 and 21. Additionally, CARS microscopy was able to image calcium hydroxyapatite deposits within 14 days following osteogenic induction, which was confirmed by Alizarin Red-Staining and RT- PCR. Taken together, the multimodal label-free analysis methods Raman spectroscopy, CARS and SHG microscopy can monitor osteogenic differentiation of adult human stem cells into osteoblasts with high sensitivity and spatial resolution in three dimensions. Our findings suggest a great potential of these optical detection methods for clinical applications including in vivo observation of bone tissue-implant-interfaces or disease diagnosis.

Label-free nonlinear optical microscopy detects early markers for osteogenic differentiation of human stem cells

PubMed Central

Hofemeier, Arne D.; Hachmeister, Henning; Pilger, Christian; Schürmann, Matthias; Greiner, Johannes F. W.; Nolte, Lena; Sudhoff, Holger; Kaltschmidt, Christian; Huser, Thomas; Kaltschmidt, Barbara

2016-01-01

Tissue engineering by stem cell differentiation is a novel treatment option for bone regeneration. Most approaches for the detection of osteogenic differentiation are invasive or destructive and not compatible with live cell analysis. Here, non-destructive and label-free approaches of Raman spectroscopy, coherent anti-Stokes Raman scattering (CARS) and second harmonic generation (SHG) microscopy were used to detect and image osteogenic differentiation of human neural crest-derived inferior turbinate stem cells (ITSCs). Combined CARS and SHG microscopy was able to detect markers of osteogenesis within 14 days after osteogenic induction. This process increased during continued differentiation. Furthermore, Raman spectroscopy showed significant increases of the PO43− symmetric stretch vibrations at 959 cm−1 assigned to calcium hydroxyapatite between days 14 and 21. Additionally, CARS microscopy was able to image calcium hydroxyapatite deposits within 14 days following osteogenic induction, which was confirmed by Alizarin Red-Staining and RT- PCR. Taken together, the multimodal label-free analysis methods Raman spectroscopy, CARS and SHG microscopy can monitor osteogenic differentiation of adult human stem cells into osteoblasts with high sensitivity and spatial resolution in three dimensions. Our findings suggest a great potential of these optical detection methods for clinical applications including in vivo observation of bone tissue–implant-interfaces or disease diagnosis. PMID:27225821

Electronic hybridisation implications for the damage-tolerance of thin film metallic glasses

PubMed Central

Schnabel, Volker; Jaya, B. Nagamani; Köhler, Mathias; Music, Denis; Kirchlechner, Christoph; Dehm, Gerhard; Raabe, Dierk; Schneider, Jochen M.

2016-01-01

A paramount challenge in materials science is to design damage-tolerant glasses. Poisson’s ratio is commonly used as a criterion to gauge the brittle-ductile transition in glasses. However, our data, as well as results in the literature, are in conflict with the concept of Poisson’s ratio serving as a universal parameter for fracture energy. Here, we identify the electronic structure fingerprint associated with damage tolerance in thin film metallic glasses. Our correlative theoretical and experimental data reveal that the fraction of bonds stemming from hybridised states compared to the overall bonding can be associated with damage tolerance in thin film metallic glasses. PMID:27819318

Electronic hybridisation implications for the damage-tolerance of thin film metallic glasses.

PubMed

Schnabel, Volker; Jaya, B Nagamani; Köhler, Mathias; Music, Denis; Kirchlechner, Christoph; Dehm, Gerhard; Raabe, Dierk; Schneider, Jochen M

2016-11-07

A paramount challenge in materials science is to design damage-tolerant glasses. Poisson's ratio is commonly used as a criterion to gauge the brittle-ductile transition in glasses. However, our data, as well as results in the literature, are in conflict with the concept of Poisson's ratio serving as a universal parameter for fracture energy. Here, we identify the electronic structure fingerprint associated with damage tolerance in thin film metallic glasses. Our correlative theoretical and experimental data reveal that the fraction of bonds stemming from hybridised states compared to the overall bonding can be associated with damage tolerance in thin film metallic glasses.

Low cost industrial production of coagulation factor IX bioencapsulated in lettuce cells for oral tolerance induction in hemophilia B

PubMed Central

Su, Jin; Zhu, Liqing; Sherman, Alexandra; Wang, Xiaomei; Lin, Shina; Kamesh, Aditya; Norikane, Joey H.; Streatfield, Stephen J.; Herzog, Roland W.; Daniell, Henry

2015-01-01

Antibodies (inhibitors) developed by hemophilia B patients against coagulation factor IX (FIX) are challenging to eliminate because of anaphylaxis or nephrotic syndrome after continued infusion. To address this urgent unmet medical need, FIX fused with a transmucosal carrier (CTB) was produced in a commercial lettuce (Simpson Elite) cultivar using species specific chloroplast vectors regulated by endogenous psbA sequences. CTB-FIX (~1mg/g) in lyophilized cells was stable with proper folding, disulfide bonds and pentamer assembly when stored ~2 years at ambient temperature. Feeding lettuce cells to hemophilia B mice delivered CTB-FIX efficiently to the gut immune system, induced LAP+ regulatory T cells and suppressed inhibitor/IgE formation and anaphylaxis against FIX. Lyophilized cells enabled 10-fold dose escalation studies and successful induction of oral tolerance was observed in all tested doses. Induction of tolerance in such a broad dose range should enable oral delivery to patients of different age groups and diverse genetic background. Using Fraunhofer cGMP hydroponic system, ~870 kg fresh or 43.5 kg dry weight can be harvested per 1000 ft2 per annum yielding 24,000–36,000 doses for 20-kg pediatric patients, enabling first commercial development of an oral drug, addressing prohibitively expensive purification, cold storage/transportation and short shelf life of current protein drugs. PMID:26302233

Isolation, expansion, and differentiation of goat adipose-derived stem cells.

PubMed

Ren, Yu; Wu, Haiqing; Zhou, Xueyuan; Wen, Jianxun; Jin, Muzi; Cang, Ming; Guo, Xudong; Wang, Qinglian; Liu, Dongjun; Ma, Yuzhen

2012-08-01

A goat adipose-derived stem cell (ADSC) line was established and compared to a rat line. Goat ADSC cells had normal diploidy after subculture. Proliferation of goat ADSCs was faster than rat cells in the same conditions. Both rat and goat ADSCs stained positively for vimentin, CD49d, CD44 and CD13, but stained negatively for CD34 and CD106. Bone nodules were apparent, and alizarin staining was positive after osteogenic induction. Cells expressing osteocalcin were positive by alkaline phosphatase (ALP) staining. After osteogenic induction, ossification nodules of goat ADSCs were larger than in rats, with dense ALP staining. Adipogenic induction resulting in lipid droplets and peroxisome proliferator-activated receptor (PPARγ2) expression were observed. Cartilage lacunae were formed and COL2A1 was expressed. More cartilage lacunae with better morphology were seen following differentiation of goat ADSC's using the hang-drop method. For goat ADSCs, results with both adherent-induced and hanging-drop induced cultures were better than for three-dimensional cultures. Copyright © 2012. Published by Elsevier India Pvt Ltd.

Human reaming debris: a source of multipotent stem cells.

PubMed

Wenisch, Sabine; Trinkaus, Katja; Hild, Anne; Hose, Dirk; Herde, Katja; Heiss, Christian; Kilian, Olaf; Alt, Volker; Schnettler, Reinhard

2005-01-01

The biological characteristics of human reaming debris (HRD) generated in the course of surgical treatment of long bone diaphyseal fractures and nonunions are still a matter of dispute. Therefore, the objective of the present investigation has been to characterize the intrinsic properties of human reaming debris in vitro. Samples of reaming debris harvested from 12 patients with closed diaphyseal fractures were examined ultrastucturally and were cultured under standard conditions. After a lag phase of 4-7 days, cells started to grow out from small bone fragments and established a confluent monolayer within 20-22 days. The cells were characterized according to morphology, proliferation capacity, cell surface antigen profile, and differentiation repertoire. The results reveal that human reaming debris is a source of multipotent stem cells which are able to grow and proliferate in vitro. The cells differentiate along the osteogenic pathway after induction and can be directed toward a neuronal phenotype, as has been shown morphologically and by the expression of neuronal markers after DMSO induction. These findings have prompted interest in the use of reaming debris-derived stem cells in cell and bone replacement therapies.

Sonic hedgehog protein promotes proliferation and chondrogenic differentiation of bone marrow-derived mesenchymal stem cells in vitro.

PubMed

Warzecha, Jörg; Göttig, Stephan; Brüning, Christian; Lindhorst, Elmar; Arabmothlagh, Mohammad; Kurth, Andreas

2006-10-01

Sonic hedgehog (Shh) protein is known to be an important signaling protein in early embryonic development. Also, Shh is involved in the induction of early cartilaginous differentiation of mesenchymal cells in the limb and in the spine. The impact of Shh on adult stem cells, human bone marrow-derived mesenchymal stem cells (MSCs), was tested. The MSCs were treated either with recombinant Sonic hedgehog protein (r-Shh) or with transforming growth factor-beta 1 (TGF-beta(1)) as a positive control in vitro for 3 weeks. The effects on cartilaginous differentiation and proliferation were assayed. MSCs when treated with either Shh or TGF-beta(1) showed expression of cartilage markers aggrecan, Sox9, CEP-68, and collagen type II and X within 3 weeks. Only r-Shh-treated cells showed a very strong cell proliferation and much higher BrdU incorporation in cell assay systems. These are the first data that indicate an important role of Shh for the induction of cartilage production by MSCs in vitro.

A stable and reproducible human blood-brain barrier model derived from hematopoietic stem cells.

PubMed

Cecchelli, Romeo; Aday, Sezin; Sevin, Emmanuel; Almeida, Catarina; Culot, Maxime; Dehouck, Lucie; Coisne, Caroline; Engelhardt, Britta; Dehouck, Marie-Pierre; Ferreira, Lino

2014-01-01

The human blood brain barrier (BBB) is a selective barrier formed by human brain endothelial cells (hBECs), which is important to ensure adequate neuronal function and protect the central nervous system (CNS) from disease. The development of human in vitro BBB models is thus of utmost importance for drug discovery programs related to CNS diseases. Here, we describe a method to generate a human BBB model using cord blood-derived hematopoietic stem cells. The cells were initially differentiated into ECs followed by the induction of BBB properties by co-culture with pericytes. The brain-like endothelial cells (BLECs) express tight junctions and transporters typically observed in brain endothelium and maintain expression of most in vivo BBB properties for at least 20 days. The model is very reproducible since it can be generated from stem cells isolated from different donors and in different laboratories, and could be used to predict CNS distribution of compounds in human. Finally, we provide evidence that Wnt/β-catenin signaling pathway mediates in part the BBB inductive properties of pericytes.

Differential Response to Soil Salinity in Endangered Key Tree Cactus: Implications for Survival in a Changing Climate

PubMed Central

Goodman, Joie; Maschinski, Joyce; Hughes, Phillip; McAuliffe, Joe; Roncal, Julissa; Powell, Devon; Sternberg, Leonel O'reilly

2012-01-01

Understanding reasons for biodiversity loss is essential for developing conservation and management strategies and is becoming increasingly urgent with climate change. Growing at elevations <1.4 m in the Florida Keys, USA, the endangered Key tree cactus (Pilosocereus robinii) experienced 84 percent loss of total stems from 1994 to 2007. The most severe losses of 99 and 88 percent stems occurred in the largest populations in the Lower Keys, where nine storms with high wind velocities and storm surges, occurred during this period. In contrast, three populations had substantial stem proliferation. To evaluate possible mortality factors related to changes in climate or forest structure, we examined habitat variables: soil salinity, elevation, canopy cover, and habitat structure near 16 dying or dead and 18 living plants growing in the Lower Keys. Soil salinity and elevation were the preliminary factors that discriminated live and dead plants. Soil salinity was 1.5 times greater, but elevation was 12 cm higher near dead plants than near live plants. However, distribution-wide stem loss was not significantly related to salinity or elevation. Controlled salinity trials indicated that salt tolerance to levels above 40 mM NaCl was related to maternal origin. Salt sensitive plants from the Lower Keys had less stem growth, lower root:shoot ratios, lower potassium: sodium ratios and lower recovery rate, but higher δ 13C than a salt tolerant lineage of unknown origin. Unraveling the genetic structure of salt tolerant and salt sensitive lineages in the Florida Keys will require further genetic tests. Worldwide rare species restricted to fragmented, low-elevation island habitats, with little or no connection to higher ground will face challenges from climate change-related factors. These great conservation challenges will require traditional conservation actions and possibly managed relocation that must be informed by studies such as these. PMID:22403670

Differential response to soil salinity in endangered key tree cactus: implications for survival in a changing climate.

PubMed

Goodman, Joie; Maschinski, Joyce; Hughes, Phillip; McAuliffe, Joe; Roncal, Julissa; Powell, Devon; Sternberg, Leonel O'reilly

2012-01-01

Understanding reasons for biodiversity loss is essential for developing conservation and management strategies and is becoming increasingly urgent with climate change. Growing at elevations <1.4 m in the Florida Keys, USA, the endangered Key tree cactus (Pilosocereus robinii) experienced 84 percent loss of total stems from 1994 to 2007. The most severe losses of 99 and 88 percent stems occurred in the largest populations in the Lower Keys, where nine storms with high wind velocities and storm surges, occurred during this period. In contrast, three populations had substantial stem proliferation. To evaluate possible mortality factors related to changes in climate or forest structure, we examined habitat variables: soil salinity, elevation, canopy cover, and habitat structure near 16 dying or dead and 18 living plants growing in the Lower Keys. Soil salinity and elevation were the preliminary factors that discriminated live and dead plants. Soil salinity was 1.5 times greater, but elevation was 12 cm higher near dead plants than near live plants. However, distribution-wide stem loss was not significantly related to salinity or elevation. Controlled salinity trials indicated that salt tolerance to levels above 40 mM NaCl was related to maternal origin. Salt sensitive plants from the Lower Keys had less stem growth, lower root:shoot ratios, lower potassium: sodium ratios and lower recovery rate, but higher δ (13)C than a salt tolerant lineage of unknown origin. Unraveling the genetic structure of salt tolerant and salt sensitive lineages in the Florida Keys will require further genetic tests. Worldwide rare species restricted to fragmented, low-elevation island habitats, with little or no connection to higher ground will face challenges from climate change-related factors. These great conservation challenges will require traditional conservation actions and possibly managed relocation that must be informed by studies such as these.

The epithelial-mesenchymal transition generates cells with properties of stem cells.

PubMed

Mani, Sendurai A; Guo, Wenjun; Liao, Mai-Jing; Eaton, Elinor Ng; Ayyanan, Ayyakkannu; Zhou, Alicia Y; Brooks, Mary; Reinhard, Ferenc; Zhang, Cheng Cheng; Shipitsin, Michail; Campbell, Lauren L; Polyak, Kornelia; Brisken, Cathrin; Yang, Jing; Weinberg, Robert A

2008-05-16

The epithelial-mesenchymal transition (EMT) is a key developmental program that is often activated during cancer invasion and metastasis. We here report that the induction of an EMT in immortalized human mammary epithelial cells (HMLEs) results in the acquisition of mesenchymal traits and in the expression of stem-cell markers. Furthermore, we show that those cells have an increased ability to form mammospheres, a property associated with mammary epithelial stem cells. Independent of this, stem cell-like cells isolated from HMLE cultures form mammospheres and express markers similar to those of HMLEs that have undergone an EMT. Moreover, stem-like cells isolated either from mouse or human mammary glands or mammary carcinomas express EMT markers. Finally, transformed human mammary epithelial cells that have undergone an EMT form mammospheres, soft agar colonies, and tumors more efficiently. These findings illustrate a direct link between the EMT and the gain of epithelial stem cell properties.

Generation and characterization of human iPSC line generated from mesenchymal stem cells derived from adipose tissue.

PubMed

Zapata-Linares, Natalia; Rodriguez, Saray; Mazo, Manuel; Abizanda, Gloria; Andreu, Enrique J; Barajas, Miguel; Prosper, Felipe; Rodriguez-Madoz, Juan R

2016-01-01

In this work, mesenchymal stem cells derived from adipose tissue (ADSCs) were used for the generation of the human-induced pluripotent stem cell line G15.AO. Cell reprogramming was performed using retroviral vectors containing the Yamanaka factors, and the generated G15.AO hiPSC line showed normal karyotype, silencing of the exogenous reprogramming factors, induction of the typical pluripotency-associated markers, alkaline phosphatase enzymatic activity, and in vivo and in vitro differentiation ability to the three germ layers. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Haematopoietic stem cell transplantation as first-line treatment in myeloma: a global perspective of current concepts and future possibilities

PubMed Central

Mactier, Catriona Elizabeth; Islam, Md Serajul

2012-01-01

Stem cell transplantation forms an integral part of the treatment for multiple myeloma. This paper reviews the current role of transplantation and the progress that has been made in order to optimize the success of this therapy. Effective induction chemotherapy is important and a combination regimen incorporating the novel agent bortezomib is now favorable. Adequate induction is a crucial adjunct to stem cell transplantation and in some cases may potentially postpone the need for transplant. Different conditioning agents prior to transplantation have been explored: high-dose melphalan is most commonly used and bortezomib is a promising additional agent. There is no well-defined superior transplantation protocol but single or tandem autologous stem cell transplantations are those most commonly used, with allogeneic transplantation only used in clinical trials. The appropriate timing of transplantation in the treatment plan is a matter of debate. Consolidation and maintenance chemotherapies, particularly thalidomide and bortezomib, aim to improve and prolong disease response to transplantation and delay recurrence. Prognostic factors for the outcome of stem cell transplant in myeloma have been highlighted. Despite good responses to chemotherapy and transplantation, the problem of disease recurrence persists. Thus, there is still much room for improvement. Treatments which harness the graft-versus-myeloma effect may offer a potential cure for this disease. Trials of novel agents are underway, including targeted therapies for specific antigens such as vaccines and monoclonal antibodies. PMID:25992212

Myostatin acts as an autocrine/paracrine negative regulator in myoblast differentiation from human induced pluripotent stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Fei; Kishida, Tsunao; Ejima, Akika

Highlights: ► iPS-derived cells express myostatin and its receptor upon myoblast differentiation. ► Myostatin inhibits myoblast differentiation by inhibiting MyoD and Myo5a induction. ► Silencing of myostatin promotes differentiation of human iPS cells into myoblasts. -- Abstract: Myostatin, also known as growth differentiation factor (GDF-8), regulates proliferation of muscle satellite cells, and suppresses differentiation of myoblasts into myotubes via down-regulation of key myogenic differentiation factors including MyoD. Recent advances in stem cell biology have enabled generation of myoblasts from pluripotent stem cells, but it remains to be clarified whether myostatin is also involved in regulation of artificial differentiation of myoblastsmore » from pluripotent stem cells. Here we show that the human induced pluripotent stem (iPS) cell-derived cells that were induced to differentiate into myoblasts expressed myostatin and its receptor during the differentiation. An addition of recombinant human myostatin (rhMyostatin) suppressed induction of MyoD and Myo5a, resulting in significant suppression of myoblast differentiation. The rhMyostatin treatment also inhibited proliferation of the cells at a later phase of differentiation. RNAi-mediated silencing of myostatin promoted differentiation of human iPS-derived embryoid body (EB) cells into myoblasts. These results strongly suggest that myostatin plays an important role in regulation of myoblast differentiation from iPS cells of human origin. The present findings also have significant implications for potential regenerative medicine for muscular diseases.« less

Transcriptional Analysis of Fracture Healing and the Induction of Embryonic Stem Cell–Related Genes

PubMed Central

Bais, Manish; McLean, Jody; Sebastiani, Paola; Young, Megan; Wigner, Nathan; Smith, Temple; Kotton, Darrell N.; Einhorn, Thomas A.; Gerstenfeld, Louis C.

2009-01-01

Fractures are among the most common human traumas. Fracture healing represents a unique temporarily definable post-natal process in which to study the complex interactions of multiple molecular events that regulate endochondral skeletal tissue formation. Because of the regenerative nature of fracture healing, it is hypothesized that large numbers of post-natal stem cells are recruited and contribute to formation of the multiple cell lineages that contribute to this process. Bayesian modeling was used to generate the temporal profiles of the transcriptome during fracture healing. The temporal relationships between ontologies that are associated with various biologic, metabolic, and regulatory pathways were identified and related to developmental processes associated with skeletogenesis, vasculogenesis, and neurogenesis. The complement of all the expressed BMPs, Wnts, FGFs, and their receptors were related to the subsets of transcription factors that were concurrently expressed during fracture healing. We further defined during fracture healing the temporal patterns of expression for 174 of the 193 genes known to be associated with human genetic skeletal disorders. In order to identify the common regulatory features that might be present in stem cells that are recruited during fracture healing to other types of stem cells, we queried the transcriptome of fracture healing against that seen in embryonic stem cells (ESCs) and mesenchymal stem cells (MSCs). Approximately 300 known genes that are preferentially expressed in ESCs and ∼350 of the known genes that are preferentially expressed in MSCs showed induction during fracture healing. Nanog, one of the central epigenetic regulators associated with ESC stem cell maintenance, was shown to be associated in multiple forms or bone repair as well as MSC differentiation. In summary, these data present the first temporal analysis of the transcriptome of an endochondral bone formation process that takes place during fracture healing. They show that neurogenesis as well as vasculogenesis are predominant components of skeletal tissue formation and suggest common pathways are shared between post-natal stem cells and those seen in ESCs. PMID:19415118

Curcumin inhibits cancer stem cell phenotypes in ex vivo models of colorectal liver metastases, and is clinically safe and tolerable in combination with FOLFOX chemotherapy

PubMed Central

James, Mark I.; Iwuji, Chinenye; Irving, Glen; Karmokar, Ankur; Higgins, Jennifer A.; Griffin-Teal, Nicola; Thomas, Anne; Greaves, Peter; Cai, Hong; Patel, Samita R.; Morgan, Bruno; Dennison, Ashley; Metcalfe, Matthew; Garcea, Giuseppe; Lloyd, David M.; Berry, David P.; Steward, William P.; Howells, Lynne M.; Brown, Karen

2015-01-01

In vitro and pre-clinical studies have suggested that addition of the diet-derived agent curcumin may provide a suitable adjunct to enhance efficacy of chemotherapy in models of colorectal cancer. However, the majority of evidence for this currently derives from established cell lines. Here, we utilised patient-derived colorectal liver metastases (CRLM) to assess whether curcumin may provide added benefit over 5-fluorouracil (5-FU) and oxaliplatin (FOLFOX) in cancer stem cell (CSC) models. Combination of curcumin with FOLFOX chemotherapy was then assessed clinically in a phase I dose escalation study. Curcumin alone and in combination significantly reduced spheroid number in CRLM CSC models, and decreased the number of cells with high aldehyde dehydrogenase activity (ALDHhigh/CD133−). Addition of curcumin to oxaliplatin/5-FU enhanced anti-proliferative and pro-apoptotic effects in a proportion of patient-derived explants, whilst reducing expression of stem cell-associated markers ALDH and CD133. The phase I dose escalation study revealed curcumin to be a safe and tolerable adjunct to FOLFOX chemotherapy in patients with CRLM (n = 12) at doses up to 2 grams daily. Curcumin may provide added benefit in subsets of patients when administered with FOLFOX, and is a well-tolerated chemotherapy adjunct. PMID:25979230

Epigenomics and bolting tolerance in sugar beet genotypes.

PubMed

Hébrard, Claire; Peterson, Daniel G; Willems, Glenda; Delaunay, Alain; Jesson, Béline; Lefèbvre, Marc; Barnes, Steve; Maury, Stéphane

2016-01-01

In sugar beet (Beta vulgaris altissima), bolting tolerance is an essential agronomic trait reflecting the bolting response of genotypes after vernalization. Genes involved in induction of sugar beet bolting have now been identified, and evidence suggests that epigenetic factors are involved in their control. Indeed, the time course and amplitude of DNA methylation variations in the shoot apical meristem have been shown to be critical in inducing sugar beet bolting, and a few functional targets of DNA methylation during vernalization have been identified. However, molecular mechanisms controlling bolting tolerance levels among genotypes are still poorly understood. Here, gene expression and DNA methylation profiles were compared in shoot apical meristems of three bolting-resistant and three bolting-sensitive genotypes after vernalization. Using Cot fractionation followed by 454 sequencing of the isolated low-copy DNA, 6231 contigs were obtained that were used along with public sugar beet DNA sequences to design custom Agilent microarrays for expression (56k) and methylation (244k) analyses. A total of 169 differentially expressed genes and 111 differentially methylated regions were identified between resistant and sensitive vernalized genotypes. Fourteen sequences were both differentially expressed and differentially methylated, with a negative correlation between their methylation and expression levels. Genes involved in cold perception, phytohormone signalling, and flowering induction were over-represented and collectively represent an integrative gene network from environmental perception to bolting induction. Altogether, the data suggest that the genotype-dependent control of DNA methylation and expression of an integrative gene network participate in bolting tolerance in sugar beet, opening up perspectives for crop improvement. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Continuous subcutaneous insulin infusion allows tolerance induction and diabetes treatment in a type 1 diabetic child with insulin allergy.

PubMed

Hasselmann, C; Pecquet, C; Bismuth, E; Raverdy, C; Sola-Gazagnes, A; Lobut, J-B; Carel, J-C; Tubiana-Rufi, N

2013-04-01

Insulin allergy is a rare but serious and challenging condition in patients with type 1 diabetes (T1D). This is a case report of an 8-year-old boy with T1D and an allergy to insulin. Three months after being diagnosed with T1D, the patient developed progressive skin reactions to insulin, characterized by small 1.5-cm pruritic wheals at injection sites that persisted for several days. Seven months after diagnosis, he experienced two episodes of generalized urticaria with systemic symptoms that were seen within a few seconds of insulin injection. Examination revealed lipoatrophy of the thighs. Intradermal skin tests were positive for protamine, glargine and lispro. The patient was started on a continuous subcutaneous insulin infusion (CSII) tolerance induction protocol, consisting of a very low basal rate that was progressively increased, with the first bolus given under medical supervision, and was well tolerated for 4 months. After this period of time, the skin wheals reappeared, localized to the infusion sites, but without urticaria or any other generalized reactions. Intradermal skin tests were repeated and were again positive. Serum insulin-specific IgE measured 30 months after the first allergic reactions were positive. After 3 years, pump therapy is ongoing and blood glucose control has remained relatively good (HbA1c 7.6%). In T1D children with insulin allergy, CSII can successfully be used to both induce insulin tolerance and allow diabetes insulin therapy, although insulin desensitization cannot always be fully achieved. The induction protocol was easily manageable partly due to the "honeymoon" period that the patient was still in, but it should nonetheless be used even when the patient has higher insulin requirements. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Recombinant Lactococcus lactis can make the difference in antigen-specific immune tolerance induction, the Type 1 Diabetes case

PubMed Central

2014-01-01

Especially in western civilizations, immune diseases that are driven by innocuous (auto- or allo-) antigens are gradually evolving to become pandemic threats. A particularly poignant example is type 1 diabetes, where young children are confronted with the perspective and consequences of total pancreatic β-cell destruction. Along these disquieting observations we find ourselves equipped with impressively accumulating molecular immunological knowledge on the ins and outs of these pathologies. Often, however, it is difficult to translate this wealth into efficacious medicines. The molecular understanding, the concept of oral tolerance induction, the benefit of using recombinant Lactococcus lactis therein and recent openings towards their clinical use may well enable turning all colors to their appropriate fields on this Rubik's cube. PMID:25185797

Somatic embryogenesis and plant regeneration in Carica papaya L. tissue culture derived from root explants.

PubMed

Chen, M H; Wang, P J; Maeda, E

1987-10-01

The regeneration potential of shoot tip, stem, leaf, cotyledon and root explants of two papaya cultivars (Carica papaya cv. 'Solo' and cv. 'Sunrise') were studed. Callus induction of these two cultivars of papaya showed that the shoot tips and stems are most suitable for forming callus, while leaves, cotyledons and roots are comparatively difficult to induce callus. Callus induction also varied with the varities. Somatic embryogenesis was obtained from 3-month-old root cultures. A medium containing half strength of MS inorganic salts, 160 mg/l adenine sulfate, 1.0 mg/1 NAA, 0.5 mg/1 kinetin and 1.0 mg/1 GA3 was optimal for embryogenesis. The callus maintained high regenerative capacity after two years of culture on this medium. Plants derived from somatic embryos were obtained under green-house conditions.

Maintenance and induction of murine embryonic stem cell differentiation using E-cadherin-Fc substrata without colony formation

NASA Astrophysics Data System (ADS)

Meng, Qing-Yuan; Akaike, Toshihiro

2013-03-01

Induced embryonic stem (ES) cells are expected to be promising cell resources for the observation of the cell behaviors in developmental biology as well as the implantation in cell treatments in human diseases. A recombinant E-cadherin substratum was developed as a cell recognizable substratum to maintain the ES cells' self-renewal and pluripotency at single cell level. Furthermore, the generation of various cell lineages in different germ layers, including hepatic or neural cells, was achieved on the chimeric protein layer precisely and effectively. The induction and isolation of specific cell population was carried out with the enhancing effect of other artificial extracellular matrices (ECMs) in enzyme-free process. The murine ES cell-derived cells showed highly morphological similarities and functional expressions to matured hepatocytes or neural progenitor cells.

Modulation between high- and low-frequency transcutaneous electric nerve stimulation delays the development of analgesic tolerance in arthritic rats.

PubMed

Desantana, Josimari M; Santana-Filho, Valter J; Sluka, Kathleen A

2008-04-01

To investigate whether repeated administration of modulating frequency transcutaneous electric nerve stimulation (TENS) prevents development of analgesic tolerance. Knee joint inflammation (3% carrageenan and kaolin) was induced in rats. Either mixed or alternating frequency was administered daily (20min) for 2 weeks to the inflamed knee under light halothane anesthesia (1%-2%). Laboratory. Adult male Sprague-Dawley rats (N=36). Mixed- (4Hz and 100Hz) or alternating- (4Hz on 1 day; 100Hz on the next day) frequency TENS at sensory intensity and 100micros pulse duration. Paw and joint withdrawal thresholds to mechanical stimuli were assessed before induction of inflammation, and before and after daily application of TENS. The reduced paw and joint withdrawal thresholds that occur 24 hours after the induction of inflammation were significantly reversed by the first administration of TENS when compared with sham treatment or to the condition before TENS treatment, which was observed through day 9. By the tenth day, repeated daily administration of either mixed- or alternating-frequency TENS did not reverse the decreased paw and joint withdrawal thresholds. These data suggest that repeated administration of modulating frequency TENS leads to a development of opioid tolerance. However, this tolerance effect is delayed by approximately 5 days compared with administration of low- or high-frequency TENS independently. Clinically, we can infer that a treatment schedule of repeated daily TENS administration will result in a tolerance effect. Moreover, modulating low and high frequency TENS seems to produce a better analgesic effect and tolerance is slower to develop.

Modulation of liver tolerance by conventional and nonconventional antigen-presenting cells and regulatory immune cells

PubMed Central

Horst, Andrea Kristina; Neumann, Katrin; Diehl, Linda; Tiegs, Gisa

2016-01-01

The liver is a tolerogenic organ with exquisite mechanisms of immune regulation that ensure upkeep of local and systemic immune tolerance to self and foreign antigens, but that is also able to mount effective immune responses against pathogens. The immune privilege of liver allografts was recognized first in pigs in spite of major histo-compatibility complex mismatch, and termed the “liver tolerance effect”. Furthermore, liver transplants are spontaneously accepted with only low-dose immunosuppression, and induce tolerance for non-hepatic co-transplanted allografts of the same donor. Although this immunotolerogenic environment is favorable in the setting of organ transplantation, it is detrimental in chronic infectious liver diseases like hepatitis B or C, malaria, schistosomiasis or tumorigenesis, leading to pathogen persistence and weak anti-tumor effects. The liver is a primary site of T-cell activation, but it elicits poor or incomplete activation of T cells, leading to their abortive activation, exhaustion, suppression of their effector function and early death. This is exploited by pathogens and can impair pathogen control and clearance or allow tumor growth. Hepatic priming of T cells is mediated by a number of local conventional and nonconventional antigen-presenting cells (APCs), which promote tolerance by immune deviation, induction of T-cell anergy or apoptosis, and generating and expanding regulatory T cells. This review will focus on the communication between classical and nonclassical APCs and lymphocytes in the liver in tolerance induction and will discuss recent insights into the role of innate lymphocytes in this process. PMID:27041638

In Vitro Differentiation and Propagation of Urothelium from Pluripotent Stem Cell Lines.

PubMed

Osborn, Stephanie L; Kurzrock, Eric A

2018-01-01

Bioengineering of bladder tissue, particularly for those patients who have advanced bladder disease, requires a source of urothelium that is healthy, capable of significant proliferation in vitro and immunologically tolerated upon transplant. As pluripotent stem cells have the potential to fulfill such criteria, they provide a critical cell source from which urothelium might be derived in vitro and used clinically. Herein, we describe the in vitro differentiation of urothelium from the H9 human embryonic stem cell (hESC) line through the definitive endoderm (DE) phase via selective culture techniques. The protocol can be used to derive urothelium from other hESCs or human-induced pluripotent stem cells.

Differential expression of ion transporters and aquaporins in leaves may contribute to different salt tolerance in Malus species.

PubMed

Liu, Changhai; Li, Chao; Liang, Dong; Wei, Zhiwei; Zhou, Shasha; Wang, Rongchao; Ma, Fengwang

2012-09-01

Maintaining ion and water homeostasis in plants is an important defense strategy against salinity stress. Divergence in ion homeostasis between the salt-tolerant Malus hupehensis Rehd. and salt-sensitive Malus prunifolia 'yingyehaitang' was studied to understand their mechanisms for tolerance. Compared with the control on Day 15, plants of those two genotypes under high-salinity treatment had less K(+) in the leaves, stems, and roots. Contents were higher in the roots but lower in the leaves of M. hupehensis while levels in the stems were similar to those from M. prunifolia. For both genotypes, the sodium content increased after salinity treatment in all tissue types. However, the leaves from M. hupehensis had less Na(+) and maintained a lower Na(+)/K(+) ratio. To understand the basis for these differences, we studied the ion transporters and regulation of aquaporin transcripts in the leaves. Transcript levels for both MdHKT1 and MdSOS1 were higher in M. hupehensis, implying that this species had better capacity to exclude sodium so that less Na(+) occurred in the leaves but more in the stems. M. hupehensis also had a greater amount of MdNHX1 transcripts, which could have assisted in sequestering excess Na(+) into the vacuoles and sustaining a better cellular environment. A relatively higher level of aquaporin transcript was also found in M. hupehensis, suggesting that those plants were more capable of maintaining a better leaf water status and diluting excess ions effectively under high-salinity conditions. Therefore, these tested transporters may play important roles in determining how salinity tolerance is conferred in Malus species. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Conditional induction of Math1 specifies embryonic stem cells to cerebellar granule neuron lineage and promotes differentiation into mature granule neurons.

PubMed

Srivastava, Rupali; Kumar, Manoj; Peineau, Stéphane; Csaba, Zsolt; Mani, Shyamala; Gressens, Pierre; El Ghouzzi, Vincent

2013-04-01

Directing differentiation of embryonic stem cells (ESCs) to specific neuronal subtype is critical for modeling disease pathology in vitro. An attractive means of action would be to combine regulatory differentiation factors and extrinsic inductive signals added to the culture medium. In this study, we have generated mature cerebellar granule neurons by combining a temporally controlled transient expression of Math1, a master gene in granule neuron differentiation, with inductive extrinsic factors involved in cerebellar development. Using a Tetracyclin-On transactivation system, we overexpressed Math1 at various stages of ESCs differentiation and found that the yield of progenitors was considerably increased when Math1 was induced during embryonic body stage. Math1 triggered expression of Mbh1 and Mbh2, two target genes directly involved in granule neuron precursor formation and strong expression of early cerebellar territory markers En1 and NeuroD1. Three weeks after induction, we observed a decrease in the number of glial cells and an increase in that of neurons albeit still immature. Combining Math1 induction with extrinsic factors specifically increased the number of neurons that expressed Pde1c, Zic1, and GABAα6R characteristic of mature granule neurons, formed "T-shaped" axons typical of granule neurons, and generated synaptic contacts and action potentials in vitro. Finally, in vivo implantation of Math1-induced progenitors into young adult mice resulted in cell migration and settling of newly generated neurons in the cerebellum. These results show that conditional induction of Math1 drives ESCs toward the cerebellar fate and indicate that acting on both intrinsic and extrinsic factors is a powerful means to modulate ESCs differentiation and maturation into a specific neuronal lineage. Copyright © 2012 AlphaMed Press.

Intersection of transfer cells with phloem biology—broad evolutionary trends, function, and induction

PubMed Central

Andriunas, Felicity A.; Zhang, Hui-Ming; Xia, Xue; Patrick, John W.; Offler, Christina E.

2013-01-01

Transfer cells (TCs) are ubiquitous throughout the plant kingdom. Their unique ingrowth wall labyrinths, supporting a plasma membrane enriched in transporter proteins, provides these cells with an enhanced membrane transport capacity for resources. In certain plant species, TCs have been shown to function to facilitate phloem loading and/or unloading at cellular sites of intense resource exchange between symplasmic/apoplasmic compartments. Within the phloem, the key cellular locations of TCs are leaf minor veins of collection phloem and stem nodes of transport phloem. In these locations, companion and phloem parenchyma cells trans-differentiate to a TC morphology consistent with facilitating loading and re-distribution of resources, respectively. At a species level, occurrence of TCs is significantly higher in transport than in collection phloem. TCs are absent from release phloem, but occur within post-sieve element unloading pathways and particularly at interfaces between generations of developing Angiosperm seeds. Experimental accessibility of seed TCs has provided opportunities to investigate their inductive signaling, regulation of ingrowth wall formation and membrane transport function. This review uses this information base to explore current knowledge of phloem transport function and inductive signaling for phloem-associated TCs. The functional role of collection phloem and seed TCs is supported by definitive evidence, but no such information is available for stem node TCs that present an almost intractable experimental challenge. There is an emerging understanding of inductive signals and signaling pathways responsible for initiating trans-differentiation to a TC morphology in developing seeds. However, scant information is available to comment on a potential role for inductive signals (auxin, ethylene and reactive oxygen species) that induce seed TCs, in regulating induction of phloem-associated TCs. Biotic phloem invaders have been used as a model to speculate on involvement of these signals. PMID:23847631

The protective effect of rapid cold-hardening develops more quickly in frozen versus supercooled larvae of the Antarctic midge, Belgica antarctica.

PubMed

Kawarasaki, Yuta; Teets, Nicholas M; Denlinger, David L; Lee, Richard E

2013-10-15

During the austral summer, larvae of the terrestrial midge Belgica antarctica (Diptera: Chironomidae) experience highly variable and often unpredictable thermal conditions. In addition to remaining freeze tolerant year-round, larvae are capable of swiftly increasing their cold tolerance through the rapid cold-hardening (RCH) response. The present study compared the induction of RCH in frozen versus supercooled larvae. At the same induction temperature, RCH occurred more rapidly and conferred a greater level of cryoprotection in frozen versus supercooled larvae. Furthermore, RCH in frozen larvae could be induced at temperatures as low as -12°C, which is the lowest temperature reported to induce RCH. Remarkably, as little as 15 min at -5°C significantly enhanced larval cold tolerance. Not only is protection from RCH acquired swiftly, but it is also quickly lost after thawing for 2 h at 2°C. Because the primary difference between frozen and supercooled larvae is cellular dehydration caused by freeze concentration of body fluids, we also compared the effects of acclimation in dehydrated versus frozen larvae. Because slow dehydration without chilling significantly increased larval survival to a subsequent cold exposure, we hypothesize that cellular dehydration caused by freeze concentration promotes the rapid acquisition of cold tolerance in frozen larvae.

Chlorophyll Fluorescence as a Possible Tool for Salinity Tolerance Screening in Barley (Hordeum vulgare L.).

PubMed Central

Belkhodja, R.; Morales, F.; Abadia, A.; Gomez-Aparisi, J.; Abadia, J.

1994-01-01

The application of chlorophyll fluorescence measurements to screening barley (Hordeum vulgare L.) genotypes for salinity tolerance has been investigated. Excised barley leaves were cut under water and incubated with the cut end immersed in water or in a 100-mM NaCl solution, either in the dark or in high light. Changes in rapid fluorescence kinetics occurred in excised barley leaves exposed to the saline solution only when the incubation was carried out in the presence of high light. Fluorescence changes consisted of decreases in the variable to maximum fluorescence ratio and in increases in the relative proportion of variable fluorescence leading to point I in the Kautsky fluorescence induction curve. These relative increases in fluorescence at point I appeared to arise from a delayed plastoquinone reoxidation in the dark, since they disappeared after short, far-red illumination, which is known to excite photosystem I preferentially. We show that a significant correlation existed between some fluorescence parameters, measured after a combined salt and high-light treatment, and other independent measurements of salinity tolerance. These results suggest that chlorophyll fluorescence, and especially the relative fluorescence at point I in the Kautsky fluorescence induction curve, could be used for the screening of barley genotypes for salinity tolerance. PMID:12232117

Epithelial Cell Rests of Malassez Contain Unique Stem Cell Populations Capable of Undergoing Epithelial–Mesenchymal Transition

PubMed Central

Xiong, Jimin; Mrozik, Krzysztof; Gronthos, Stan

2012-01-01

The epithelial cell rests of Malassez (ERM) are odontogenic epithelial cells located within the periodontal ligament matrix. While their function is unknown, they may support tissue homeostasis and maintain periodontal ligament space or even contribute to periodontal regeneration. We investigated the notion that ERM contain a subpopulation of stem cells that could undergo epithelial–mesenchymal transition and differentiate into mesenchymal stem-like cells with multilineage potential. For this purpose, ERM collected from ovine incisors were subjected to different inductive conditions in vitro, previously developed for the characterization of bone marrow mesenchymal stromal/stem cells (BMSC). We found that ex vivo-expanded ERM expressed both epithelial (cytokeratin-8, E-cadherin, and epithelial membrane protein-1) and BMSC markers (CD44, CD29, and heat shock protein-90β). Integrin α6/CD49f could be used for the enrichment of clonogenic cell clusters [colony-forming units-epithelial cells (CFU-Epi)]. Integrin α6/CD49f-positive-selected epithelial cells demonstrated over 50- and 7-fold greater CFU-Epi than integrin α6/CD49f-negative cells and unfractionated cells, respectively. Importantly, ERM demonstrated stem cell-like properties in their differentiation capacity to form bone, fat, cartilage, and neural cells in vitro. When transplanted into immunocompromised mice, ERM generated bone, cementum-like and Sharpey's fiber-like structures. Additionally, gene expression studies showed that osteogenic induction of ERM triggered an epithelial–mesenchymal transition. In conclusion, ERM are unusual cells that display the morphological and phenotypic characteristics of ectoderm-derived epithelial cells; however, they also have the capacity to differentiate into a mesenchymal phenotype and thus represent a unique stem cell population within the periodontal ligament. PMID:22122577

Immunotherapy with myeloid cells for tolerance induction

PubMed Central

Rodriguez-García, Mercedes; Boros, Peter; Bromberg, Jonathan S.; Ochando, Jordi C.

2013-01-01

Purpose of review Understanding the interplay between myeloid dendritic cells and T cells under tolerogenic conditions, and whether their interactions induce the development of antigen-specific regulatory T cells (Tregs) is critical to uncover the mechanisms involved in the induction of indefinite allograft survival. Recent findings Myeloid dendritic cell–T-cell interactions are seminal events that determine the outcome of the immune response, and multiple in-vitro protocols suggest the generation of tolerogenic myeloid dendritic cells that modulate T-cell responses, and determine the outcome of the immune response to an allograft following adoptive transfer. We believe that identifying specific conditions that lead to the generation of tolerogenic myeloid dendritic cells and Tregs are critical for the manipulation the immune response towards the development of transplantation tolerance. Summary We summarize recent findings regarding specific culture conditions that generate tolerogenic myeloid dendritic cells that induce T-cell hyporesponsiveness and Treg development, and represents a novel immunotherapeutic approach to promote the induction of indefinite graft survival prolongation. The interpretations presented here illustrate that different mechanisms govern the generation tolerogenic myeloid dendritic cells, and we discuss the concomitant therapeutic implications. PMID:20616727

Identification of Regulatory T Cells in Tolerated Allografts

PubMed Central

Graca, Luis; Cobbold, Stephen P.; Waldmann, Herman

2002-01-01

Induction of transplantation tolerance with certain therapeutic nondepleting monoclonal antibodies can lead to a robust state of peripheral “dominant” tolerance. Regulatory CD4+ T cells, which mediate this form of “dominant” tolerance, can be isolated from spleens of tolerant animals. To determine whether there were any extra-lymphoid sites that might harbor regulatory T cells we sought their presence in tolerated skin allografts and in normal skin. When tolerated skin grafts are retransplanted onto T cell–depleted hosts, graft-infiltrating T cells exit the graft and recolonize the new host. These colonizing T cells can be shown to contain members with regulatory function, as they can prevent nontolerant lymphocytes from rejecting fresh skin allografts, without hindrance of rejection of third party skin. Our results suggest that T cell suppression of graft rejection is an active process that operates beyond secondary lymphoid tissue, and involves the persistent presence of regulatory T cells at the site of the tolerated transplant. PMID:12070291

Effect of physical training in cool and hot environments on +Gz acceleration tolerance in women

NASA Technical Reports Server (NTRS)

Brock, P. J.; Sciaraffa, D.; Greenleaf, J. E.

1982-01-01

Acceleration tolerance, plasma volume, and maximal oxygen uptake were measured in 15 healthy women before and after submaximal isotonic exercise training periods in cool and hot environments. The women were divided on the basis of age, maximal oxygen uptake, and +Gz tolerance into three groups: a group that exercised in heat (40.6 C), a group that exercised at a lower temperature (18.7 C), and a sedentary control group that functioned in the cool environment. There was no significant change in the +Gz tolerance in any group after training, and terminal heart rates were similar within each group. It is concluded that induction of moderate acclimation responses without increases in sweat rate or resting plasma volume has no influence on +Gz acceleration tolerance in women.

Stem CO2 efflux in six co-occurring tree species: underlying factors and ecological implications.

PubMed

Rodríguez-Calcerrada, Jesús; López, Rosana; Salomón, Roberto; Gordaliza, Guillermo G; Valbuena-Carabaña, María; Oleksyn, Jacek; Gil, Luis

2015-06-01

Stem respiration plays a role in species coexistence and forest dynamics. Here we examined the intra- and inter-specific variability of stem CO2 efflux (E) in dominant and suppressed trees of six deciduous species in a mixed forest stand: Fagus sylvatica L., Quercus petraea [Matt.] Liebl, Quercus pyrenaica Willd., Prunus avium L., Sorbus aucuparia L. and Crataegus monogyna Jacq. We conducted measurements in late autumn. Within species, dominants had higher E per unit stem surface area (Es ) mainly because sapwood depth was higher than in suppressed trees. Across species, however, differences in Es corresponded with differences in the proportion of living parenchyma in sapwood and concentration of non-structural carbohydrates (NSC). Across species, Es was strongly and NSC marginally positively related with an index of drought tolerance, suggesting that slow growth of drought-tolerant trees is related to higher NSC concentration and Es . We conclude that, during the leafless period, E is indicative of maintenance respiration and is related with some ecological characteristics of the species, such as drought resistance; that sapwood depth is the main factor explaining variability in Es within species; and that the proportion of NSC in the sapwood is the main factor behind variability in Es among species. © 2014 John Wiley & Sons Ltd.

Ruminative and mindful self-focused attention in borderline personality disorder.

PubMed

Sauer, Shannon E; Baer, Ruth A

2012-10-01

The current study investigated the short-term effects of mindful and ruminative forms of self-focused attention on a behavioral measure of distress tolerance in individuals with borderline personality disorder (BPD) who had completed an angry mood induction. Participants included 40 individuals who met criteria for BPD and were currently involved in mental health treatment. Each completed an individual 1-hr session. Following an angry mood induction, each participant was randomly assigned to engage in ruminative or mindful self-focus for several minutes. All participants then completed the computerized Paced Auditory Serial Addition Test (PASAT-C), a behavioral measure of willingness to tolerate distress in the service of goal-directed behavior. The mindfulness group persisted significantly longer than the rumination group on the distress tolerance task and reported significantly lower levels of anger following the self-focus period. Results are consistent with previous studies in suggesting that distinct forms of self-focused attention have distinct outcomes and that, for people with BPD, mindful self-observation is an adaptive alternative to rumination when feeling angry. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

Innovative Approaches for Immune Tolerance to Factor VIII in the Treatment of Hemophilia A

PubMed Central

Sherman, Alexandra; Biswas, Moanaro; Herzog, Roland W.

2017-01-01

Hemophilia A (coagulation factor VIII deficiency) is a debilitating genetic disorder that is primarily treated with intravenous replacement therapy. Despite a variety of factor VIII protein formulations available, the risk of developing anti-dug antibodies (“inhibitors”) remains. Overall, 20–30% of patients with severe disease develop inhibitors. Current clinical immune tolerance induction protocols to eliminate inhibitors are not effective in all patients, and there are no prophylactic protocols to prevent the immune response. New experimental therapies, such as gene and cell therapies, show promising results in pre-clinical studies in animal models of hemophilia. Examples include hepatic gene transfer with viral vectors, genetically engineered regulatory T cells (Treg), in vivo Treg induction using immune modulatory drugs, and maternal antigen transfer. Furthermore, an oral tolerance protocol is being developed based on transgenic lettuce plants, which suppressed inhibitor formation in hemophilic mice and dogs. Hopefully, some of these innovative approaches will reduce the risk of and/or more effectively eliminate inhibitor formation in future treatment of hemophilia A. PMID:29225598

Notes on the Problems of the Transplantation of Kidneys in Dogs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Puza, A.; Drahovsky, V.; Neubauer, E.

1963-01-01

In a group of 29 mongrel dogs kidney homotransplantation was performed. In five dogs an autograft was performed to check the suitability of the surgical technique. In the remaining 24 dogs kidney homografts were carried out, Five dogs served as controls; in these animals the functioning of the homografted kidney stopped after 8 days on the average, In 12 animals an attempt at the induction of immunological tolerance by exsanguinotransfusion, whole-body irradiation and 6-MP-administration was made. Induction of immunological tolerance by total exsanguinotransfusion immediately after birth may render possible a successful homograft even in adult life. The transplanted organ thenmore » exhibits a permanent take and takes over the function of the recipient's removed kidneys. One dog is alive with its single kidney homograft after almost two years. 6-MP administration may lead to such a degree of induced tolerance that the function of a kidney homograft is prolonged by a factor of two to three. Whole-body irradiation within a range of 400 rad (Co 60 source) does not significantly prolong homograft survival.« less

Mechanisms Underlying Tolerance after Long-Term Benzodiazepine Use: A Future for Subtype-Selective GABAA Receptor Modulators?

PubMed Central

Vinkers, Christiaan H.; Olivier, Berend

2012-01-01

Despite decades of basic and clinical research, our understanding of how benzodiazepines tend to lose their efficacy over time (tolerance) is at least incomplete. In appears that tolerance develops relatively quickly for the sedative and anticonvulsant actions of benzodiazepines, whereas tolerance to anxiolytic and amnesic effects probably does not develop at all. In light of this evidence, we review the current evidence for the neuroadaptive mechanisms underlying benzodiazepine tolerance, including changes of (i) the GABAA receptor (subunit expression and receptor coupling), (ii) intracellular changes stemming from transcriptional and neurotrophic factors, (iii) ionotropic glutamate receptors, (iv) other neurotransmitters (serotonin, dopamine, and acetylcholine systems), and (v) the neurosteroid system. From the large variance in the studies, it appears that either different (simultaneous) tolerance mechanisms occur depending on the benzodiazepine effect, or that the tolerance-inducing mechanism depends on the activated GABAA receptor subtypes. Importantly, there is no convincing evidence that tolerance occurs with α subunit subtype-selective compounds acting at the benzodiazepine site. PMID:22536226

The art of fault-tolerant system reliability modeling

NASA Technical Reports Server (NTRS)

Butler, Ricky W.; Johnson, Sally C.

1990-01-01

A step-by-step tutorial of the methods and tools used for the reliability analysis of fault-tolerant systems is presented. Emphasis is on the representation of architectural features in mathematical models. Details of the mathematical solution of complex reliability models are not presented. Instead the use of several recently developed computer programs--SURE, ASSIST, STEM, PAWS--which automate the generation and solution of these models is described.

Desiccation tolerance of five tropical seedlings in Panama. Relationship to a field assessment of drought performance

Treesearch

Melvin T. Tyree; Bettina M.J. Engelbrecht; Gustavo Vargas; Thomas A. Kursar

2003-01-01

Studies of the desiccation tolerance of the seedlings of five tropical trees were made on potted plants growing in a greenhouse. Pots were watered to field capacity and then dehydrated for 3 to 9 weeks to reach various visual wilting stages, from slightly wilted to dead. Saturated root hydraulic conductance was measured with a high-pressure flowmeter, and whole-stem...

78 FR 37468 - Cyproconazole; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-21

..., and single-cell necrosis. For both subchronic and chronic durations, hepatotoxicity was observed in... = 1X..... LOAEL = 3.2 mg/kg/day based on liver effects (P450 induction in females and histopathology...

Emerging Importance of Phytochemicals in Regulation of Stem Cells Fate via Signaling Pathways.

PubMed

Dadashpour, Mehdi; Pilehvar-Soltanahmadi, Younes; Zarghami, Nosratollah; Firouzi-Amandi, Akram; Pourhassan-Moghaddam, Mohammad; Nouri, Mohammad

2017-11-01

To reach ideal therapeutic potential of stem cells for regenerative medicine purposes, it is essential to retain their self-renewal and differentiation capacities. Currently, biological factors are extensively used for stemness maintaining and differentiation induction of stem cells. However, low stability, high cost, complicated production process, and risks associated with viral/endotoxin infection hamper the widespread use of biological factors in the stem cell biology. Moreover, regarding the modulation of several signaling cascades, which lead to a distinct fate, phytochemicals are preferable in the stem cells biology because of their efficiency. Considering the issues related to the application of biological factors and potential advantages of phytochemicals in stem cell engineering, there is a considerable increasing trend in studies associated with the application of novel alternative molecules in the stem cell biology. In support of this statement, we aimed to highlight the various effects of phytochemicals on signaling cascades involved in commitment of stem cells. Hence, in this review, the current trends in the phytochemicals-based modulation of stem cell fate have been addressed. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Comparative transcriptome analysis of differentially expressed genes in foxtail millet (Setaria italica L.) during dehydration stress.

PubMed

Lata, Charu; Sahu, Pranav Pankaj; Prasad, Manoj

2010-03-19

Dehydration stress is one of the most important abiotic stresses that adversely influence crop growth and productivity. With the aim to understand the molecular mechanisms underlying dehydration stress tolerance in foxtail millet (Setaria italica L.), a drought tolerant crop, we examined its transcriptome changes at two time points (early and late) of dehydration stress. Two suppression subtractive hybridization (SSH) forward libraries were constructed from 21-day old seedlings of tolerant cv. Prasad at 0.5 and 6h PEG-induced dehydration stress. A total of 327 unique ESTs were identified from both libraries and were classified into 11 different categories according to their putative functions. The plant response against dehydration stress was complex, representing major transcripts involved in metabolism, stress, signaling, transcription regulation, translation and proteolysis. By Reverse Northern (RN) technique we identified the differential expression pattern of 327 transcripts, 86 (about 26%) of which showed > or = 1.7-fold induction. Further the obtained results were validated by quantitative real-time PCR (qRT-PCR) to have a comparative expression profiling of randomly chosen 9 up-regulated transcripts (> or =2.5 fold induction) between cv. Prasad (tolerant) and cv. Lepakshi (sensitive) upon dehydration stress. These transcripts showed a differential expression pattern in both cultivars at different time points of stress treatment as analyzed by qRT-PCR. The possible relationship of the identified transcripts with dehydration tolerance mechanism is discussed. Copyright 2010 Elsevier Inc. All rights reserved.

Biomarkers of tolerance: searching for the hidden phenotype.

PubMed

Perucha, Esperanza; Rebollo-Mesa, Irene; Sagoo, Pervinder; Hernandez-Fuentes, Maria P

2011-08-01

Induction of transplantation tolerance remains the ideal long-term clinical and logistic solution to the current challenges facing the management of renal allograft recipients. In this review, we describe the recent studies and advances made in identifying biomarkers of renal transplant tolerance, from study inceptions, to the lessons learned and their implications for current and future studies with the same goal. With the age of biomarker discovery entering a new dimension of high-throughput technologies, here we also review the current approaches, developments, and pitfalls faced in the subsequent statistical analysis required to identify valid biomarker candidates.

Mitochondrial Dynamics Impacts Stem Cell Identity and Fate Decisions by Regulating a Nuclear Transcriptional Program.

PubMed

Khacho, Mireille; Clark, Alysen; Svoboda, Devon S; Azzi, Joelle; MacLaurin, Jason G; Meghaizel, Cynthia; Sesaki, Hiromi; Lagace, Diane C; Germain, Marc; Harper, Mary-Ellen; Park, David S; Slack, Ruth S

2016-08-04

Regulated mechanisms of stem cell maintenance are key to preventing stem cell depletion and aging. While mitochondrial morphology plays a fundamental role in tissue development and homeostasis, its role in stem cells remains unknown. Here, we uncover that mitochondrial dynamics regulates stem cell identity, self-renewal, and fate decisions by orchestrating a transcriptional program. Manipulation of mitochondrial structure, through OPA1 or MFN1/2 deletion, impaired neural stem cell (NSC) self-renewal, with consequent age-dependent depletion, neurogenesis defects, and cognitive impairments. Gene expression profiling revealed ectopic expression of the Notch self-renewal inhibitor Botch and premature induction of transcription factors that promote differentiation. Changes in mitochondrial dynamics regulate stem cell fate decisions by driving a physiological reactive oxygen species (ROS)-mediated process, which triggers a dual program to suppress self-renewal and promote differentiation via NRF2-mediated retrograde signaling. These findings reveal mitochondrial dynamics as an upstream regulator of essential mechanisms governing stem cell self-renewal and fate decisions through transcriptional programming. Copyright © 2016 Elsevier Inc. All rights reserved.

Natural genetic variation of freezing tolerance in Arabidopsis.

PubMed

Hannah, Matthew A; Wiese, Dana; Freund, Susanne; Fiehn, Oliver; Heyer, Arnd G; Hincha, Dirk K

2006-09-01

Low temperature is a primary determinant of plant growth and survival. Using accessions of Arabidopsis (Arabidopsis thaliana) originating from Scandinavia to the Cape Verde Islands, we show that freezing tolerance of natural accessions correlates with habitat winter temperatures, identifying low temperature as an important selective pressure for Arabidopsis. Combined metabolite and transcript profiling show that during cold exposure, global changes of transcripts, but not of metabolites, correlate with the ability of Arabidopsis to cold acclimate. There are, however, metabolites and transcripts, including several transcription factors, that correlate with freezing tolerance, indicating regulatory pathways that may be of primary importance for this trait. These data identify that enhanced freezing tolerance is associated with the down-regulation of photosynthesis and hormonal responses and the induction of flavonoid metabolism, provide evidence for naturally increased nonacclimated freezing tolerance due to the constitutive activation of the C-repeat binding factors pathway, and identify candidate transcriptional regulators that correlate with freezing tolerance.

Variation in sulfide tolerance of photosystem II in phylogenetically diverse cyanobacteria from sulfidic habitats

NASA Technical Reports Server (NTRS)

Miller, Scott R.; Bebout, Brad M.

2004-01-01

Physiological and molecular phylogenetic approaches were used to investigate variation among 12 cyanobacterial strains in their tolerance of sulfide, an inhibitor of oxygenic photosynthesis. Cyanobacteria from sulfidic habitats were found to be phylogenetically diverse and exhibited an approximately 50-fold variation in photosystem II performance in the presence of sulfide. Whereas the degree of tolerance was positively correlated with sulfide levels in the environment, a strain's phenotype could not be predicted from the tolerance of its closest relatives. These observations suggest that sulfide tolerance is a dynamic trait primarily shaped by environmental variation. Despite differences in absolute tolerance, similarities among strains in the effects of sulfide on chlorophyll fluorescence induction indicated a common mode of toxicity. Based on similarities with treatments known to disrupt the oxygen-evolving complex, it was concluded that sulfide toxicity resulted from inhibition of the donor side of photosystem II.

Deciphering the role of the phenylpropanoid metabolism in the tolerance of Capsicum annuum L. to Verticillium dahliae Kleb.

PubMed

Novo, Marta; Silvar, Cristina; Merino, Fuencisla; Martínez-Cortés, Teresa; Lu, Fachuang; Ralph, John; Pomar, Federico

2017-05-01

Verticillium dahliae is an economically relevant soilborne pathogen that causes vascular wilt in several crops, including pepper (Capsicum annuum). Fungal infection is usually visualized as a vascular browning, likely due to the onset of phenylpropanoid metabolism, which also seems to play a crucial role in the tolerance of some pepper varieties. In the current work, the potential function of distinct phenylpropanoid derivatives (suberin, lignin and phenolic compounds) in the pepper tolerance response against V. dahliae, was investigated. Histochemical and biochemical analyses ruled out suberin as a key player in the pepper-fungus interaction. However, changes observed in lignin composition and higher deposition of bound phenolics in infected stems seemed to contribute to the reinforcement of cell walls and the impairment of V. dahliae colonization. Most importantly, this is the first time that the accumulation of the hydroxycinnamic acid amide N-feruloyltyramine was reported in pepper stems in response to a vascular fungus. Fungitoxic activity for that hydroxycinnamate-tyramine conjugate was demonstrated as well. Copyright © 2017 Elsevier B.V. All rights reserved.

Volatile-Mediated Effects Predominate in Paraburkholderia phytofirmans Growth Promotion and Salt Stress Tolerance of Arabidopsis thaliana

PubMed Central

Ledger, Thomas; Rojas, Sandy; Timmermann, Tania; Pinedo, Ignacio; Poupin, María J.; Garrido, Tatiana; Richter, Pablo; Tamayo, Javier

2016-01-01

Abiotic stress has a growing impact on plant growth and agricultural activity worldwide. Specific plant growth promoting rhizobacteria have been reported to stimulate growth and tolerance to abiotic stress in plants, and molecular mechanisms like phytohormone synthesis and 1-aminocyclopropane-1-carboxylate deamination are usual candidates proposed to mediate these bacterial effects. Paraburkholderia phytofirmans PsJN is able to promote growth of several plant hosts, and improve their tolerance to chilling, drought and salinity. This work investigated bacterial determinants involved in PsJN stimulation of growth and salinity tolerance in Arabidopsis thaliana, showing bacteria enable plants to survive long-term salinity treatment, accumulating less sodium within leaf tissues relative to non-inoculated controls. Inactivation of specific bacterial genes encoding ACC deaminase, auxin catabolism, N-acyl-homoserine-lactone production, and flagellin synthesis showed these functions have little influence on bacterial induction of salinity tolerance. Volatile organic compound emission from strain PsJN was shown to reproduce the effects of direct bacterial inoculation of roots, increasing plant growth rate and tolerance to salinity evaluated both in vitro and in soil. Furthermore, early exposure to VOCs from P. phytofirmans was sufficient to stimulate long-term effects observed in Arabidopsis growth in the presence and absence of salinity. Organic compounds were analyzed in the headspace of PsJN cultures, showing production of 2-undecanone, 7-hexanol, 3-methylbutanol and dimethyl disulfide. Exposure of A. thaliana to different quantities of these molecules showed that they are able to influence growth in a wide range of added amounts. Exposure to a blend of the first three compounds was found to mimic the effects of PsJN on both general growth promotion and salinity tolerance. To our knowledge, this is the first report on volatile compound-mediated induction of plant abiotic stress tolerance by a Paraburkholderia species. PMID:27909432

Function of FEZF1 during early neural differentiation of human embryonic stem cells.

PubMed

Liu, Xin; Su, Pei; Lu, Lisha; Feng, Zicen; Wang, Hongtao; Zhou, Jiaxi

2018-01-01

The understanding of the mechanism underlying human neural development has been hampered due to lack of a cellular system and complicated ethical issues. Human embryonic stem cells (hESCs) provide an invaluable model for dissecting human development because of unlimited self-renewal and the capacity to differentiate into nearly all cell types in the human body. In this study, using a chemical defined neural induction protocol and molecular profiling, we identified Fez family zinc finger 1 (FEZF1) as a potential regulator of early human neural development. FEZF1 is rapidly up-regulated during neural differentiation in hESCs and expressed before PAX6, a well-established marker of early human neural induction. We generated FEZF1-knockout H1 hESC lines using CRISPR-CAS9 technology and found that depletion of FEZF1 abrogates neural differentiation of hESCs. Moreover, loss of FEZF1 impairs the pluripotency exit of hESCs during neural specification, which partially explains the neural induction defect caused by FEZF1 deletion. However, enforced expression of FEZF1 itself fails to drive neural differentiation in hESCs, suggesting that FEZF1 is necessary but not sufficient for neural differentiation from hESCs. Taken together, our findings identify one of the earliest regulators expressed upon neural induction and provide insight into early neural development in human.

Xenogeneic human umbilical cord-derived mesenchymal stem cells reduce mortality in rats with acute respiratory distress syndrome complicated by sepsis

PubMed Central

Wallace, Christopher Glenn; Sung, Pei-Hsun; Sheu, Jiunn-Jye; Chung, Sheng-Ying; Chen, Yung-Lung; Lu, Hung-I; Ko, Sheung-Fat; Sun, Cheuk-Kwan; Chiang, Hsin-Ju; Chang, Hsueh-Wen; Lee, Mel S.; Yip, Hon-Kan

2017-01-01

This study tested the hypothesis that xenogeneic human umbilical cord-derived mesenchymal stem cell (HUCDMSC) therapy would improve survival rates in rats with acute respiratory distress-syndrome (ARDS, induction by 48 h inhalation of 100% oxygen) and sepsis-syndrome (SS, induction by cecal-ligation and puncture) (ARDS-SS). Adult-male Sprague-Dawley rats were categorized into group 1 (sham-controls), group 2 (ARDS-SS), group 3 [ARDS-SS+HUCDMSC (1.2 ×106 cells administered 1 h after SS-induction)], and group 4 [ARDS-SS+HUCDMSC (1.2 ×106 cells administered 24 h after SS-induction)]. The mortality rate was higher in groups 2 and 4 than in groups 1 and 3 (all p<0.0001). The blood pressure after 28 h was lower in groups 2, 3 and 4 (p<0.0001) than in group 1. Albumin levels and percentages of inflammatory cells in broncho-alveolar lavage fluid, and the percentages of inflammatory and immune cells in circulation, were lowest in group 1, highest in group 2, and higher in group 3 than group 4 (all p<0.0001). The percentages of inflammatory cells in ascites and kidney parenchyma showed identical patterns, as did kidney injury scores (all p<0.0001). EarlyHUCDMSC therapy reduced rodent mortality after induced ARDS-SS. PMID:28484089

Xenogeneic human umbilical cord-derived mesenchymal stem cells reduce mortality in rats with acute respiratory distress syndrome complicated by sepsis.

PubMed

Lee, Fan-Yen; Chen, Kuan-Hung; Wallace, Christopher Glenn; Sung, Pei-Hsun; Sheu, Jiunn-Jye; Chung, Sheng-Ying; Chen, Yung-Lung; Lu, Hung-I; Ko, Sheung-Fat; Sun, Cheuk-Kwan; Chiang, Hsin-Ju; Chang, Hsueh-Wen; Lee, Mel S; Yip, Hon-Kan

2017-07-11

This study tested the hypothesis that xenogeneic human umbilical cord-derived mesenchymal stem cell (HUCDMSC) therapy would improve survival rates in rats with acute respiratory distress-syndrome (ARDS, induction by 48 h inhalation of 100% oxygen) and sepsis-syndrome (SS, induction by cecal-ligation and puncture) (ARDS-SS). Adult-male Sprague-Dawley rats were categorized into group 1 (sham-controls), group 2 (ARDS-SS), group 3 [ARDS-SS+HUCDMSC (1.2 ×106 cells administered 1 h after SS-induction)], and group 4 [ARDS-SS+HUCDMSC (1.2 ×106 cells administered 24 h after SS-induction)]. The mortality rate was higher in groups 2 and 4 than in groups 1 and 3 (all p<0.0001). The blood pressure after 28 h was lower in groups 2, 3 and 4 (p<0.0001) than in group 1. Albumin levels and percentages of inflammatory cells in broncho-alveolar lavage fluid, and the percentages of inflammatory and immune cells in circulation, were lowest in group 1, highest in group 2, and higher in group 3 than group 4 (all p<0.0001). The percentages of inflammatory cells in ascites and kidney parenchyma showed identical patterns, as did kidney injury scores (all p<0.0001). EarlyHUCDMSC therapy reduced rodent mortality after induced ARDS-SS.

Influence of Dietary Experience on the Induction of Preference of Adult Moths and Larvae for a New Olfactory Cue

PubMed Central

Petit, Christophe; Le Ru, Bruno; Dupas, Stéphane; Frérot, Brigitte; Ahuya, Peter; Kaiser-Arnauld, Laure; Harry, Myriam; Calatayud, Paul-André

2015-01-01

In Lepidoptera, host plant selection is first conditioned by oviposition site preference of adult females followed by feeding site preference of larvae. Dietary experience to plant volatile cues can induce larval and adult host plant preference. We investigated how the parent’s and self-experience induce host preference in adult females and larvae of three lepidopteran stem borer species with different host plant ranges, namely the polyphagous Sesamia nonagrioides, the oligophagous Busseola fusca and the monophagous Busseola nairobica, and whether this induction can be linked to a neurophysiological phenotypic plasticity. The three species were conditioned to artificial diet enriched with vanillin from the neonate larvae to the adult stage during two generations. Thereafter, two-choice tests on both larvae and adults using a Y-tube olfactometer and electrophysiological (electroantennography [EAG] recordings) experiments on adults were carried out. In the polyphagous species, the induction of preference for a new olfactory cue (vanillin) by females and 3rd instar larvae was determined by parents’ and self-experiences, without any modification of the sensitivity of the females antennae. No preference induction was found in the oligophagous and monophagous species. Our results suggest that lepidopteran stem borers may acquire preferences for new olfactory cues from the larval to the adult stage as described by Hopkins’ host selection principle (HHSP), neo-Hopkins’ principle, and the concept of ‘chemical legacy.’ PMID:26288070

Tolerance in Nonhuman Primates by Delayed Mixed Chimerism

DTIC Science & Technology

2017-12-01

person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control ...induction of mixed chimerism in a non -human primate (NHP) model. This approach, in contrast to protocols which have already reached clinical trials...principle of delayed induction of mixed chimerism in a non -human primate (NHP) model. This approach, in contrast to protocols which have already reached

An inductance Fourier decomposition-based current-hysteresis control strategy for switched reluctance motors

NASA Astrophysics Data System (ADS)

Hua, Wei; Qi, Ji; Jia, Meng

2017-05-01

Switched reluctance machines (SRMs) have attracted extensive attentions due to the inherent advantages, including simple and robust structure, low cost, excellent fault-tolerance and wide speed range, etc. However, one of the bottlenecks limiting the SRMs for further applications is its unfavorable torque ripple, and consequently noise and vibration due to the unique doubly-salient structure and pulse-current-based power supply method. In this paper, an inductance Fourier decomposition-based current-hysteresis-control (IFD-CHC) strategy is proposed to reduce torque ripple of SRMs. After obtaining a nonlinear inductance-current-position model based Fourier decomposition, reference currents can be calculated by reference torque and the derived inductance model. Both the simulations and experimental results confirm the effectiveness of the proposed strategy.

Adult Stem Cell-Based Enhancement of Nerve Conduit for Peripheral Nerve Repair

DTIC Science & Technology

2017-10-01

neurotrophically activated cell types and conditioned media (via RT-PCR and ELISA of neurotrophic factors), followed by cell storage Specific objective 9...Mesenchymal Progenitor Cells (NI-MiMPCs) and Mesenchymal Stem Cells (MSCs), quantified via ELISA . MiMPCs and MSCs were cultured in neurotrophic induction...LIF, (E) osteonectin, and (F) clusterin. All ELISA results are expressed in pg/ml or ng/ml produced per million cells. Medium taken from NI-MiMPC

Changes of neural markers expression during late neurogenic differentiation of human adipose-derived stem cells

PubMed Central

Razavi, Shahnaz; Khosravizadeh, Zahra; Bahramian, Hamid; Kazemi, Mohammad

2015-01-01

Background: Different studies have been done to obtain sufficient number of neural cells for treatment of neurodegenerative diseases, spinal cord, and traumatic brain injury because neural stem cells are limited in central nerves system. Recently, several studies have shown that adipose-derived stem cells (ADSCs) are the appropriate source of multipotent stem cells. Furthermore, these cells are found in large quantities. The aim of this study was an assessment of proliferation and potential of neurogenic differentiation of ADSCs with passing time. Materials and Methods: Neurosphere formation was used for neural induction in isolated human ADSCs (hADSCs). The rate of proliferation was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and potential of neural differentiation of induced hADSCs was evaluated by immunocytochemical and real-time reverse transcription polymerase chain reaction analysis after 10 and 14 days post-induction. Results: The rate of proliferation of induced hADSCs increased after 14 days while the expression of nestin, glial fibrillary acidic protein, and microtubule-associated protein 2 was decreased with passing time during neurogenic differentiation. Conclusion: These findings showed that the proliferation of induced cells increased with passing time, but in early neurogenic differentiation of hADSCs, neural expression was higher than late of differentiation. Thus, using of induced cells in early differentiation may be suggested for in vivo application. PMID:26605238

Purmorphamine as a Shh Signaling Activator Small Molecule Promotes Motor Neuron Differentiation of Mesenchymal Stem Cells Cultured on Nanofibrous PCL Scaffold.

PubMed

Bahrami, Naghmeh; Bayat, Mohammad; Mohamadnia, Abdolreza; Khakbiz, Mehrdad; Yazdankhah, Meysam; Ai, Jafar; Ebrahimi-Barough, Somayeh

2017-09-01

There is variety of stem cell sources but problems in ethical issues, contamination, and normal karyotype cause many limitations in obtaining and using these cells. The cells in Wharton's jelly region of umbilical cord are abundant and available stem cells with low immunological incompatibility, which could be considered for cell replacement therapy. Small molecules have been presented as less expensive biologically active compounds that can regulate different developmental process. Purmorphamine (PMA) is a small molecule that, according to some studies, possesses certain differentiation effects. In this study, we investigated the effect of the PMA on Wharton's jelly mesenchymal stem cell (WJ-MSC) differentiation into motor neuronal lineages instead of sonic hedgehog (Shh) on PCL scaffold. After exposing to induction media for 15 days, the cells were characterized for expression of motor neuron markers including PAX6, NF-H, Islet1, HB9, and choline acetyl transferase (ChAT) by quantitative reverse transcription (PCR) and immunocytochemistry. Our results demonstrated that induced WJ-MSCs with PMA could significantly express motor neuron markers in RNA and protein levels 15 days post induction. These results suggested that WJ-MSCs can differentiate to motor neuron-like cells with PMA on PCL scaffold and might provide a potential source in cell therapy for nervous system.

SHBG Is an Important Factor in Stemness Induction of Cells by DHT In Vitro and Associated with Poor Clinical Features of Prostate Carcinomas

PubMed Central

Ma, Yuanyuan; Liang, Dongming; Liu, Jian; Wen, Jian-Guo; Servoll, Einar; Waaler, Gudmund; Sæter, Thorstein; Axcrona, Karol; Vlatkovic, Ljiljana; Axcrona, Ulrika; Paus, Elisabeth; Yang, Yue; Zhang, Zhiqian; Kvalheim, Gunnar; Nesland, Jahn M.; Suo, Zhenhe

2013-01-01

Androgen plays a vital role in prostate cancer development. However, it is not clear whether androgens influence stem-like properties of prostate cancer, a feature important for prostate cancer progression. In this study, we show that upon DHT treatment in vitro, prostate cancer cell lines LNCaP and PC-3 were revealed with higher clonogenic potential and higher expression levels of stemness related factors CD44, CD90, Oct3/4 and Nanog. Moreover, sex hormone binding globulin (SHBG) was also simultaneously upregulated in these cells. When the SHBG gene was blocked by SHBG siRNA knock-down, the induction of Oct3/4, Nanog, CD44 and CD90 by DHT was also correspondingly blocked in these cells. Immunohistochemical evaluation of clinical samples disclosed weakly positive, and areas negative for SHBG expression in the benign prostate tissues, while most of the prostate carcinomas were strongly positive for SHBG. In addition, higher levels of SHBG expression were significantly associated with higher Gleason score, more seminal vesicle invasions and lymph node metastases. Collectively, our results show a role of SHBG in upregulating stemness of prostate cancer cells upon DHT exposure in vitro, and SHBG expression in prostate cancer samples is significantly associated with poor clinicopathological features, indicating a role of SHBG in prostate cancer progression. PMID:23936228

A Double-Blind, Double-Dummy, Flexible-Design Randomized Multicenter Trial: Early Safety of Single- Versus Divided-Dose Rabbit Anti-Thymocyte Globulin Induction in Renal Transplantation.

PubMed

Stevens, R B; Wrenshall, L E; Miles, C D; Farney, A C; Jie, T; Sandoz, J P; Rigley, T H; Osama Gaber, A

2016-06-01

A previous nonblinded, randomized, single-center renal transplantation trial of single-dose rabbit anti-thymocyte globulin induction (SD-rATG) showed improved efficacy compared with conventional divided-dose (DD-rATG) administration. The present multicenter, double-blind/double-dummy STAT trial (Single dose vs. Traditional Administration of Thymoglobulin) evaluated SD-rATG versus DD-rATG induction for noninferiority in early (7-day) safety and tolerability. Ninety-five patients (randomized 1:1) received 6 mg/kg SD-rATG or 1.5 mg/kg/dose DD-rATG, with tacrolimus-mycophenolate maintenance immunosuppression. The primary end point was a composite of fever, hypoxia, hypotension, cardiac complications, and delayed graft function. Secondary end points included 12-month patient survival, graft survival, and rejection. Target enrollment was 165 patients with an interim analysis scheduled after 80 patients. Interim analysis showed primary end point noninferiority of SD-rATG induction (p = 0.6), and a conditional probability of <1.73% of continued enrollment producing a significant difference (futility analysis), leading to early trial termination. Final analysis (95 patients) showed no differences in occurrence of primary end point events (p = 0.58) or patients with no, one, or more than one event (p = 0.81), or rejection, graft, or patient survival (p = 0.78, 0.47, and 0.35, respectively). In this rigorously blinded trial in adult renal transplantation, we have shown SD-rATG induction to be noninferior to DD-rATG induction in early tolerability and equivalent in 12-month safety. (Clinical Trials.gov #NCT00906204.). © Copyright 2016 The Authors. American Journal of Transplantation published by Wiley Periodicals, Inc. on behalf of the American Society of Transplantation and the American Society of Transplant Surgeons.

Mantle Cell Lymphoma International Prognostic Index but Not Pretransplantation Induction Regimen Predicts Survival for Patients With Mantle-Cell Lymphoma Receiving High-Dose Therapy and Autologous Stem-Cell Transplantation

PubMed Central

Budde, Lihua E.; Guthrie, Katherine A.; Till, Brian G.; Press, Oliver W.; Chauncey, Thomas R.; Pagel, John M.; Petersdorf, Steven H.; Bensinger, William I.; Holmberg, Leona A.; Shustov, Andrei R.; Green, Damian J.; Maloney, David G.; Gopal, Ajay K.

2011-01-01

Purpose High-dose therapy (HDT) and autologous stem-cell transplantation (ASCT) are frequently used in an attempt to improve outcome in patients with mantle-cell lymphoma (MCL); however, the importance of intensive induction regimens before transplantation is unknown. Patients and Methods To address this question, we evaluated baseline characteristics, time to treatment, induction regimen, disease status at the time of transplantation, and MIPI score at diagnosis and their associations with survival in 118 consecutive patients with MCL who received HDT and ASCT at our centers. Results The MIPI was independently associated with survival after transplantation in all 118 patients (hazard ratio [HR], 3.5; P < .001) and in the 85 patients who underwent ASCT as initial consolidation (HR, 7.2; P < .001). Overall survival rates were 93%, 60%, and 32% at 2.5 years from ASCT for all patients with low-, intermediate-, and high-risk MIPI, respectively. Low-risk MIPI scores were more common in the intensive induction group than the standard induction group in all patients (64% v 46%, respectively; P = .03) and in the initial consolidation group (66% v 45%, respectively; P = .03). After adjustment for the MIPI, an intensive induction regimen was not associated with improved survival after transplantation in all patients (HR, 0.5; P = .10), the initial consolidation group (HR, 1.1; P = .86), or patients ≤ 60 years old (HR, 0.6; P = .50). Observation of more than 3 months before initiating therapy did not yield inferior survival (HR, 2.1; P = .12) after adjustment for the MIPI in patients receiving ASCT. Conclusion An intensive induction regimen before HDT and ASCT was not associated with improved survival after adjusting for differences in MIPI scores at diagnosis. PMID:21730271

Oxygation enhances growth, gas exchange and salt tolerance of vegetable soybean and cotton in a saline vertisol.

PubMed

Bhattarai, Surya P; Midmore, David J

2009-07-01

Impacts of salinity become severe when the soil is deficient in oxygen. Oxygation (using aerated water for subsurface drip irrigation of crop) could minimize the impact of salinity on plants under oxygen-limiting soil environments. Pot experiments were conducted to evaluate the effects of oxygation (12% air volume/volume of water) on vegetable soybean (moderately salt tolerant) and cotton (salt tolerant) in a salinized vertisol at 2, 8, 14, 20 dS/m EC(e). In vegetable soybean, oxygation increased above ground biomass yield and water use efficiency (WUE) by 13% and 22%, respectively, compared with the control. Higher yield with oxygation was accompanied by greater plant height and stem diameter and reduced specific leaf area and leaf Na+ and Cl- concentrations. In cotton, oxygation increased lint yield and WUE by 18% and 16%, respectively, compared with the control, and was accompanied by greater canopy light interception, plant height and stem diameter. Oxygation also led to a greater rate of photosynthesis, higher relative water content in the leaf, reduced crop water stress index and lower leaf water potential. It did not, however, affect leaf Na+ or Cl- concentration. Oxygation invariably increased, whereas salinity reduced the K+ : Na+ ratio in the leaves of both species. Oxygation improved yield and WUE performance of salt tolerant and moderately tolerant crops under saline soil environments, and this may have a significant impact for irrigated agriculture where saline soils pose constraints to crop production.

Low cost industrial production of coagulation factor IX bioencapsulated in lettuce cells for oral tolerance induction in hemophilia B.

PubMed

Su, Jin; Zhu, Liqing; Sherman, Alexandra; Wang, Xiaomei; Lin, Shina; Kamesh, Aditya; Norikane, Joey H; Streatfield, Stephen J; Herzog, Roland W; Daniell, Henry

2015-11-01

Antibodies (inhibitors) developed by hemophilia B patients against coagulation factor IX (FIX) are challenging to eliminate because of anaphylaxis or nephrotic syndrome after continued infusion. To address this urgent unmet medical need, FIX fused with a transmucosal carrier (CTB) was produced in a commercial lettuce (Simpson Elite) cultivar using species specific chloroplast vectors regulated by endogenous psbA sequences. CTB-FIX (∼1 mg/g) in lyophilized cells was stable with proper folding, disulfide bonds and pentamer assembly when stored ∼2 years at ambient temperature. Feeding lettuce cells to hemophilia B mice delivered CTB-FIX efficiently to the gut immune system, induced LAP(+) regulatory T cells and suppressed inhibitor/IgE formation and anaphylaxis against FIX. Lyophilized cells enabled 10-fold dose escalation studies and successful induction of oral tolerance was observed in all tested doses. Induction of tolerance in such a broad dose range should enable oral delivery to patients of different age groups and diverse genetic background. Using Fraunhofer cGMP hydroponic system, ∼870 kg fresh or 43.5 kg dry weight can be harvested per 1000 ft(2) per annum yielding 24,000-36,000 doses for 20-kg pediatric patients, enabling first commercial development of an oral drug, addressing prohibitively expensive purification, cold storage/transportation and short shelf life of current protein drugs. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Multicenter analysis of treatment outcomes in adult patients with lymphoblastic lymphoma who received hyper-CVAD induction followed by hematopoietic stem cell transplantation.

PubMed

Jeong, Seong Hyun; Moon, Joon Ho; Kim, Jin Seok; Yang, Deok-Hwan; Park, Yong; Cho, Seok Goo; Kwak, Jae-Yong; Eom, Hyeon Seok; Won, Jong Ho; Hong, Jun Shik; Oh, Sung Yong; Lee, Ho Sup; Kim, Seok Jin

2015-04-01

The hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (hyper-CVAD) regimen has been widely used for lymphoblastic lymphoma (LBL) as a primary treatment. However, there is few data about its treatment outcome in Asian patients. Thus, we conducted this study to evaluate the efficacy of hyper-CVAD induction and stem cell transplantation (SCT) consolidation in LBL patients. The treatment responses of 49 patients treated with the hyper-CVAD regimen were retrospectively analyzed in 13 institutions. Given 24 patients who responded to hyper-CVAD underwent consolidation treatment with SCT, overall survival (OS) and progression-free survival (PFS) of patients who received SCT were compared with patients who did not. The overall response rate was 79 %: 73 % (36/49) complete responses, 6 % (3/49) partial responses, and 4 % (2/49) induction deaths. The major limitation for the delivery of the planned hyper-CVAD cycles was hematological toxicity. Among 39 responders, 24 patients underwent autologous (n = 16) and allogeneic SCT (n = 8) consolidation. Their 3-year OS and PFS rates were 76 and 78 %, respectively, and there was no difference in survival outcomes between autologous and allogeneic SCT. However, 15 patients without SCT consolidation showed poorer PFS even though they all achieved complete response. Thus, only seven patients maintained their response at the time of analysis. In conclusion, the hyper-CVAD regimen is effective for remission induction in LBL, and SCT consolidation after hyper-CVAD induction produced better clinical outcomes than did continuation of hyper-CVAD.

Fatty acid is a potential agent for bone tissue induction: In vitro and in vivo approach.

PubMed

Cardoso, Guinea Bc; Chacon, Erivelto; Chacon, Priscila Gl; Bordeaux-Rego, Pedro; Duarte, Adriana Ss; Saad, Sara T Olalla; Zavaglia, Cecilia Ac; Cunha, Marcelo R

2017-12-01

Our hypothesis was to investigate the fatty acid potential as a bone induction factor. In vitro and in vivo studies were performed to evaluate this approach. Oleic acid was used in a 0.5 wt.% concentration. Polycaprolactone was used as the polymeric matrix by combining solvent-casting and particulate-leaching techniques, with a final porosity of 70 wt.%, investigated by SEM images. Contact angle measurements were produced to investigate the influence of oleic acid on polycaprolactone chains. Cell culture was performed using adipocyte-derived stem cells to evaluate biocompatibility and bioactivity properties. In addition, in vivo studies were performed to evaluate the induction potential of oleic acid addition. Adipocyte-derived stem cells were used to provide differentiation after 21 days of culture. Likewise, information were obtained with in vivo data and cellular invagination was observed on both scaffolds (polycaprolactone and polycaprolactone /oleic acid); interestingly, the scaffold with oleic acid addition demonstrated that cellular migrations are not related to the surrounding tissue, indicating bioactive potential. Our hypothesis is that fatty acid may be used as a potential induction factor for bone tissue engineering. The study's findings indicate oleic acid as a possible agent for bone induction, according to data on cell differentiation, proliferation, and migration. Impact statement The biomaterial combined in this study on bone regeneration is innovative and shows promising results in the treatment of bone lesions. Polycaprolactone (PCL) and oleic acid have been studied separately. In this research, we combined biomaterials to assess the stimulus and the speed of bone healing.

Transplantation Tolerance through Hematopoietic Chimerism: Progress and Challenges for Clinical Translation

PubMed Central

Mahr, Benedikt; Granofszky, Nicolas; Muckenhuber, Moritz; Wekerle, Thomas

2017-01-01

The perception that transplantation of hematopoietic stem cells can confer tolerance to any tissue or organ from the same donor is widely accepted but it has not yet become a treatment option in clinical routine. The reasons for this are multifaceted but can generally be classified into safety and efficacy concerns that also became evident from the results of the first clinical pilot trials. In comparison to standard immunosuppressive therapies, the infection risk associated with the cytotoxic pre-conditioning necessary to allow allogeneic bone marrow engraftment and the risk of developing graft-vs.-host disease (GVHD) constitute the most prohibitive hurdles. However, several approaches have recently been developed at the experimental level to reduce or even overcome the necessity for cytoreductive conditioning, such as costimulation blockade, pro-apoptotic drugs, or Treg therapy. But even in the absence of any hazardous pretreatment, the recipients are exposed to the risk of developing GVHD as long as non-tolerant donor T cells are present. Total lymphoid irradiation and enriching the stem cell graft with facilitating cells emerged as potential strategies to reduce this peril. On the other hand, the long-lasting survival of kidney allografts, seen with transient chimerism in some clinical series, questions the need for durable chimerism for robust tolerance. From a safety point of view, loss of chimerism would indeed be favorable as it eliminates the risk of GVHD, but also complicates the assessment of tolerance. Therefore, other biomarkers are warranted to monitor tolerance and to identify those patients who can safely be weaned off immunosuppression. In addition to these safety concerns, the limited efficacy of the current pilot trials with approximately 40–60% patients becoming tolerant remains an important issue that needs to be resolved. Overall, the road ahead to clinical routine may still be rocky but the first successful long-term patients and progress in pre-clinical research provide encouraging evidence that deliberately inducing tolerance through hematopoietic chimerism might eventually make it from dream to reality. PMID:29312303

Expression of Small Heat-Shock Proteins at Low Temperatures1

PubMed Central

Sabehat, Adnan; Lurie, Susan; Weiss, David

1998-01-01

We previously reported that short exposure of tomato (Lycopersicon esculentum L.) fruits to high temperature protects them from chilling injury. To study the involvement of heat-shock proteins (HSPs) in the acquisition of low-temperature tolerance, we cloned two heat-shock-induced genes that are also expressed at low temperatures. The cloned cDNAs belong to the small HSP group. Sequence analyses of the clones showed perfect homology to the tomato-ripening gene tom66 and to the tomato chloroplastic HSP21 gene tom111. The expression of both genes was induced by high temperature in fruits, flowers, leaves, and stems, but not by low or ambient temperatures or by other stresses such as drought and anaerobic conditions. When the heated fruits were transferred to low temperature, tom66 and tom111 mRNA levels first decreased but were then reinduced. Induction was not observed in nonheated fruits at low temperature. Immunodetection of tom111-encoded protein indicated that this protein is present at low temperatures in the heated fruits. The results of this study show that the expression of tom66 and tom111 is correlated with protection against some, but not all, symptoms of chilling injury. PMID:9625718

An existentialist view on mortality salience effects: personal hardiness, death-thought accessibility, and cultural worldview defence.

PubMed

Florian, V; Mikulincer, M; Hirschberger, G

2001-09-01

Two studies examined the possible moderating role of hardiness on reactions to mortality salience inductions. A sample of 240 Israeli undergraduate students completed a hardiness scale, were exposed to a mortality salience or control induction, and then either rated the severity and punishment of 10 social transgressions (Study 1, N = 120) or performed a word-stem completion task, which tapped the accessibility of death-related thoughts (Study 2, N = 120). Results indicated that a mortality salience induction led to more severe judgments of social transgressions as well as to more severe punishments than a control induction only among participants scoring low in the hardiness scale. However, a mortality salience induction led to a higher cognitive accessibility of death-related thoughts than a control condition regardless of participants' hardiness scores. The discussion emphasizes the importance of considering inner resources when examining reactions to mortality reminders.

Substrate micropatterns produced by polymer demixing regulate focal adhesions, actin anisotropy, and lineage differentiation of stem cells.

PubMed

Vega, Sebastián L; Arvind, Varun; Mishra, Prakhar; Kohn, Joachim; Sanjeeva Murthy, N; Moghe, Prabhas V

2018-06-12

Stem cells are adherent cells whose multipotency and differentiation can be regulated by numerous microenvironmental signals including soluble growth factors and surface topography. This study describes a simple method for creating distinct micropatterns via microphase separation resulting from polymer demixing of poly(desaminotyrosyl-tyrosine carbonate) (PDTEC) and polystyrene (PS). Substrates with co-continuous (ribbons) or discontinuous (islands and pits) PDTEC regions were obtained by varying the ratio of PDTEC and sacrificial PS. Human mesenchymal stem cells (MSCs) cultured on co-continuous PDTEC substrates for 3 days in bipotential adipogenic/osteogenic (AD/OS) induction medium showed no change in cell morphology but exhibited increased anisotropic cytoskeletal organization and larger focal adhesions when compared to MSCs cultured on discontinuous micropatterns. After 14 days in bipotential AD/OS induction medium, MSCs cultured on co-continuous micropatterns exhibited increased expression of osteogenic markers, whereas MSCs on discontinuous PDTEC substrates showed a low expression of adipogenic and osteogenic differentiation markers. Substrates with graded micropatterns were able to reproduce the influence of local underlying topography on MSC differentiation, thus demonstrating their potential for high throughput analysis. This work presents polymer demixing as a simple, non-lithographic technique to produce a wide range of micropatterns on surfaces with complex geometries to influence cellular and tissue regenerative responses. Gaining a better understanding of how engineered microenvironments influence stem cell differentiation is integral to increasing the use of stem cells and materials in a wide range of tissue engineering applications. In this study, we show the range of topography obtained by polymer demixing is sufficient for investigating how surface topography affects stem cell morphology and differentiation. Our findings show that co-continuous topographies favor early (3-day) cytoskeletal anisotropy and focal adhesion maturation as well as long-term (14-day) expression of osteogenic differentiation markers. Taken together, this study presents a simple approach to pattern topographies that induce divergent responses in stem cell morphology and differentiation. Copyright © 2018. Published by Elsevier Ltd.

Epigenetic stress responses induce muscle stem-cell ageing by Hoxa9 developmental signals.

PubMed

Schwörer, Simon; Becker, Friedrich; Feller, Christian; Baig, Ali H; Köber, Ute; Henze, Henriette; Kraus, Johann M; Xin, Beibei; Lechel, André; Lipka, Daniel B; Varghese, Christy S; Schmidt, Manuel; Rohs, Remo; Aebersold, Ruedi; Medina, Kay L; Kestler, Hans A; Neri, Francesco; von Maltzahn, Julia; Tümpel, Stefan; Rudolph, K Lenhard

2016-12-15

The functionality of stem cells declines during ageing, and this decline contributes to ageing-associated impairments in tissue regeneration and function. Alterations in developmental pathways have been associated with declines in stem-cell function during ageing, but the nature of this process remains poorly understood. Hox genes are key regulators of stem cells and tissue patterning during embryogenesis with an unknown role in ageing. Here we show that the epigenetic stress response in muscle stem cells (also known as satellite cells) differs between aged and young mice. The alteration includes aberrant global and site-specific induction of active chromatin marks in activated satellite cells from aged mice, resulting in the specific induction of Hoxa9 but not other Hox genes. Hoxa9 in turn activates several developmental pathways and represents a decisive factor that separates satellite cell gene expression in aged mice from that in young mice. The activated pathways include most of the currently known inhibitors of satellite cell function in ageing muscle, including Wnt, TGFβ, JAK/STAT and senescence signalling. Inhibition of aberrant chromatin activation or deletion of Hoxa9 improves satellite cell function and muscle regeneration in aged mice, whereas overexpression of Hoxa9 mimics ageing-associated defects in satellite cells from young mice, which can be rescued by the inhibition of Hoxa9-targeted developmental pathways. Together, these data delineate an altered epigenetic stress response in activated satellite cells from aged mice, which limits satellite cell function and muscle regeneration by Hoxa9-dependent activation of developmental pathways.

Efficient generation of induced pluripotent stem cells from human bone marrow mesenchymal stem cells.

PubMed

Yulin, X; Lizhen, L; Lifei, Z; Shan, F; Ru, L; Kaimin, H; Huang, H

2012-01-01

Ectopic expression of defined sets of genetic factors can reprogramme somatic cells to induced pluripotent stem cells (iPSCs) that closely resemble embryonic stem cells. However, the low reprogramming efficiency is a significant handicap for mechanistic studies and potential clinical application. In this study, we used human bone marrow-derived mesenchymal stem cells (hBMMSCs) as target cells for reprogramming and investigated efficient iPSC generation from hBMMSCs using the compounds of p53 siRNA, valproic acid (VPA) and vitamin C (Vc) with four transcription factors OCT4, SOX2, KLF4, and c-MYC (compound induction system). The synergetic mechanism of the compounds was studied. Our results showed that the compound induction system could efficiently reprogramme hBMMSCs to iPSCs. hBMMSC-derived iPSC populations expressed pluripotent markers and had multi-potential to differentiate into three germ layer-derived cells. p53 siRNA, VPA and Vc had a synergetic effect on cell reprogramming and the combinatorial use of these substances greatly improved the efficiency of iPSC generation by suppressing the expression of p53, decreasing cell apoptosis, up-regulating the expression of the pluripotent gene OCT4 and modifying the cell cycle. Therefore, our study highlights a straightforward method for improving the speed and efficiency of iPSC generation and provides versatile tools for investigating early developmental processes such as haemopoiesis and relevant diseases. In addition, this study provides a paradigm for the combinatorial use of genetic factors and molecules to improve the efficiency of iPSC generation.

Glucose metabolite glyoxal induces senescence in telomerase-immortalized human mesenchymal stem cells

PubMed Central

2012-01-01

Background Various by-products of the cellular metabolism, such as reactive carbonyl species (RCS) are potentially harmful to cells and tissues, and play a role in many physiological and pathological processes. Among various RCS is the highly reactive dicarbonyl glyoxal (GO), which is a natural physiological metabolite produced by the auto-oxidation of glucose, and can form covalent adducts known as advanced glycation endproducts (AGE). We have previously reported that GO accelerates ageing and causes premature senescence in normal human skin fibroblasts. Results Using a bone marrow-derived telomerase-immortalised mesenchymal stem cell line hMSC-TERT we have observed that an exposure of cells to 0.75 mM and 1 mM GO induces irreversible cellular senescence within 3 days. Induction of senescence in hMSC-TERT was demonstrated by a variety of markers, including characteristic cell morphology and enlargement, vacuolisation, multinucleation, induction of senescence associated β-galactosidase, cell cycle arrest, and increased levels of a cell cycle inhibitor p16. These changes were accompanied by increased extent of DNA breaks as measured by the comet assay, and increased levels of the AGE product, carboxymethyl-lysine (CML). Furthermore, the in vitro differentiation potential of hMSC-TERT to become functional osteoblasts was highly reduced in GO-treated stem cells, as determined by alkaline phosphatase (ALP) activity and mineralized matrix (MM) formation. Conclusions The results of our study imply that an imbalanced glucose metabolism can reduce the functioning ability of stem cells in vivo both during ageing and during stem cell-based therapeutic interventions. PMID:22424056

Seedling growth and biomass allocation in relation to leaf habit and shade tolerance among 10 temperate tree species.

PubMed

Modrzyński, Jerzy; Chmura, Daniel J; Tjoelker, Mark G

2015-08-01

Initial growth of germinated seeds is an important life history stage, critical for establishment and succession in forests. Important questions remain regarding the differences among species in early growth potential arising from shade tolerance. In addition, the role of leaf habit in shaping relationships underlying shade tolerance-related differences in seedling growth remains unresolved. In this study we examined variation in morphological and physiological traits among seedlings of 10 forest tree species of the European temperate zone varying in shade tolerance and leaf habit (broadleaved winter-deciduous species vs needle-leaved conifers) during a 10-week period. Seeds were germinated and grown in a controlled environment simulating an intermediate forest understory light environment to resolve species differences in initial growth and biomass allocation. In the high-resource experimental conditions during the study, seedlings increased biomass allocation to roots at the cost of leaf biomass independent of shade tolerance and leaf habit. Strong correlations between relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf area (SLA) and leaf mass fraction (LMF) indicate that physiology and biomass allocation were equally important determinants of RGR as plant structure and leaf morphology among these species. Our findings highlight the importance of seed mass- and seed size-related root morphology (specific root length-SRL) for shade tolerance during early ontogeny. Leaf and plant morphology (SLA, LAR) were more successful in explaining variation among species due to leaf habit than shade tolerance. In both broadleaves and conifers, shade-tolerant species had lower SRL and greater allocation of biomass to stems (stem mass fraction). Light-seeded shade-intolerant species with greater SRL had greater RGR in both leaf habit groups. However, the greatest plant mass was accumulated in the group of heavy-seeded shade-tolerant broadleaves. The results of our study suggest that the combinations of plant attributes enhancing growth under high light vary with shade tolerance, but differ between leaf habit groups. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Tolerance of Erythrocytes in Poultry: Induction and Specificity

PubMed Central

Mitchison, N. A.

1962-01-01

Measurement of the rate of elimination of 51Cr-labelled erythrocytes provides a reliable test of immunity in fowls. Chickens can be rendered tolerant of homologous and turkey erythrocytes, as judged by this test, by receiving a series of transfusions of irradiated blood. The series were arranged so that foreign cells remained present in the circulation from the time of hatching. Tolerance induced by this treatment is generally incomplete, but can last indefinitely. In some chickens the manifestation of tolerance of turkey erythrocytes is delayed, probably because of passive transmission of antibody from the dam. Chickens old enough to react against small transfusions of homologous blood can still be rendered tolerant by massive transfusions. Tolerance of the erythrocytes from an individual donor extends only slightly to those from other donors. Tolerance acquired in this way, through transfusion of irradiated blood, stands in contrast to the more stable and complete tolerance that can be acquired through administration of viable cells. Viable cells, on the other hand, provide a less sensitive test, for birds which tolerate skin homografts often eliminate rapidly erythrocytes from the same donor. PMID:14474652

Stem biomass, C and N partitioning and growth efficiency of mature pedigreed black spruce on both a wet and a dry site.

Treesearch

John Major; Kurt Johnsen; Debra Barsi; Moira Campbell; John Malcolm

2013-01-01

Worldwide, efforts to manage atmospheric CO2 are being explored both by reducing emissions and by sequestering more carbon (C). Stem biomass, C, and nitrogen (N) parameters were measured in plots of first-generation (F1), 32-year-old black spruce (Picea mariana (Mill.) B.S.P.) from four full-sib families studied previously for drought tolerance and differential...

Targeting Midbodies in Ovarian Cancer Stem Cells as a Therapeutic Strategy

DTIC Science & Technology

2014-12-01

BRCA1, BRCA1, breast cancer 1 gene. MT, microtubules. 3. OVERALL PROJECT SUMMARY: Summarize the progress during appropriate reporting period...Biological and molecular heterogeneity of breast cancers correlates with their cancer stem cell content. Cell. 2010; 140:62–73. [PubMed: 20074520] 40. Pardal...cells and contributes to the tolerance to nutrient deprivation. Cancer Res. 2007; 67:9677–84. [PubMed: 17942897] 47. Sarkar S, et al. A rational

Daily chlorhexidine bathing does not increase skin toxicity after remission induction or stem cell transplantation.

PubMed

Deeren, Dries; Dewulf, Evelyne; Verfaillie, Lydie

2016-12-01

A recent multicenter study demonstrated that bathing with chlorhexidine reduces the transmission of resistant organisms and the risk of hospital-acquired bloodstream infections in ICUs. We wanted to confirm the feasibility of this strategy in a cohort of patients in a typical intensive haematology unit. Patients treated with remission induction chemotherapy, autologous or allogeneic stem cell transplantation received daily chlorhexidine bathing. To avoid deshydratation of skin, we used prophylactic application of hydrating lotion, replaced by corticosteroid cream in case of skin toxicity of chemotherapy or conditioning. We studied 15 consecutive admissions of 12 patients. Daily chlorhexidine bathing never needed to be interrupted, even though 53% of patients were treated with intravenous cytarabine. Patients were satisfied with the skin treatment and reported few unwanted effects. Daily chlorhexidine bathing was feasible in our intensive haematology unit in all patients and did not increase skin toxicity, even when treated with IV cytarabine.

Effect of airway clearance techniques on the efficacy of the sputum induction procedure.

PubMed

Elkins, M R; Lane, T; Goldberg, H; Pagliuso, J; Garske, L A; Hector, E; Marchetto, L; Alison, J A; Bye, P T P

2005-11-01

Sputum induction is used in the early identification of tuberculosis (TB) and pneumocystis infections of the lung. Although manual physiotherapy techniques to clear the airways are often incorporated in the sputum induction procedure, their efficacy in this setting is unknown. This randomised, crossover trial enrolled adults referred for sputum induction for suspected TB and pneumocystis infections of the lung. All participants underwent two sputum induction procedures, inhaling 3% saline via ultrasonic nebuliser. During one randomly allocated procedure, airway clearance techniques (chest wall percussion, vibration, huffing) were incorporated. In total, 59 participants completed the trial. The airway clearance techniques had no significant effect on how the test was tolerated, the volume expectorated or the quality of the sample obtained (assessed by the presence of alveolar macrophages). The techniques did not significantly affect how often the test identified a suspected organism, nor the sensitivity or specificity of sputum induction. In conclusion, the study was unable to demonstrate any effect of airway clearance techniques on the sputum induction procedure. The results provide some justification for not including airway clearance techniques as part of the sputum induction procedure.

Neural stem cells induce the formation of their physical niche during organogenesis

PubMed Central

Riebesehl, Bea F; Ambrosio, Elizabeth M; Stolper, Julian S; Lischik, Colin Q; Dross, Nicolas

2017-01-01

Most organs rely on stem cells to maintain homeostasis during post-embryonic life. Typically, stem cells of independent lineages work coordinately within mature organs to ensure proper ratios of cell types. Little is known, however, on how these different stem cells locate to forming organs during development. Here we show that neuromasts of the posterior lateral line in medaka are composed of two independent life-long lineages with different embryonic origins. Clonal analysis and 4D imaging revealed a hierarchical organisation with instructing and responding roles: an inner, neural lineage induces the formation of an outer, border cell lineage (nBC) from the skin epithelium. Our results demonstrate that the neural lineage is necessary and sufficient to generate nBCs highlighting self-organisation principles at the level of the entire embryo. We hypothesise that induction of surrounding tissues plays a major role during the establishment of vertebrate stem cell niches. PMID:28950935

Updated follow-up of a tolerance protocol in HLA-identical renal transplant pairs given donor hematopoietic stem cells.

PubMed

Leventhal, Joseph R; Miller, Joshua; Mathew, James M; Kurian, Sunil; Tambur, Anat R; Friedewald, John; Charrette, Jane; Abecassis, Michael M

2018-05-01

Kidney transplant recipients given donor hematopoietic stem cells from their HLA-identical living related donors have now been followed between 5 and 9½ years post-operatively. Recipients who were designated as tolerant (Tol) have remained so since the last report when the 5 year (biopsy associated) milestone was reached. There has been 1 mortality of a Tol patient, unrelated to the study protocol, while 5 (of 15) have remained Tol between 7 and 8½ years post-operatively. There has been continuing elevated T-regulatory (CD4 + CD25 High CD127 - FOXP3 + ) cells in PBMC previously reported on. Ten year renal transplant biopsies are tentatively planned. Copyright © 2018 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Use of Bone Marrow-Derived Mesenchymal Stem Cells in Improving Thioacetamide Induced Liver Fibrosis in Rats

NASA Astrophysics Data System (ADS)

Mansour, Fatma A. A.; Shaheed, Iman; Hassan, Nabiha R. A.

Liver fibrosis, is one of big problems usually ends with cirrhosis which considered a life threatening disease as the only way of treatment is the liver transplantation, this study aimed to find a new way for fibrosis treatment by the use of bone marrow isolated Mesenchymal stem cells (MSCs). Thioacetamide (TAA) was used for fibrosis induction in male Sprague Dawely (SD) rats which divided into two random groups: group infused with TAA for fibrosis induction and group as control negative group. MSCs were isolated from bone marrow of twenty five (4-5) weeks male SD rats, and labeled with fluorescent material (PKH26) to confirm the homing of cells. After fibrosis induction, rats were divided into four subgroups to study the effect of MSCs injection in fibrosis treatment. After 4 weeks from MSCs administration, all rats were sacrificed. Liver tissue were collected for histopathological and immunohistopathological studies. In comparison with control groups, the treated groups with MSCs showed improvement in the amount of deposited collagen which decreased compared to control positive group. So MSCs can be used to replace liver transplantation in the treatment of fibrosis.

Haemopoietic cell renewal in radiation fields

NASA Astrophysics Data System (ADS)

Fliedner, T. M.; Nothdurft, W.; Tibken, B.; Hofer, E.; Weiss, M.; Kindler, H.

1994-10-01

Space flight activities are inevitably associated with a chronic exposure of astronauts to a complex mixture of ionising radiation. Although no acute radiation consequences are to be expected as a rule, the possibility of Solar Particle Events (SPE) associated with relatively high doses of radiation (1 or more Gray) cannot be excluded. It is the responsibility of physicians in charge of the health of astronauts to evaluate before, during and after space flight activities the functional status of haemopoietic cell renewal. Chronic low level exposure of dogs indicate that daily gamma-exposure doses below about 2 cGy are tolerated for several years as far as blood cell concentrations are concerned. However, the stem cell pool may be severely affected. The maintenance of sufficient blood cell counts is possible only through increased cell production to compensate for the radiation inflicted excess cell loss. This behaviour of haemopoietic cell renewal during chronic low level exposure can be simulated by bioengineering models of granulocytopoiesis. It is possible to define a ``turbulence region'' for cell loss rates, below which an prolonged adaptation to increased radiation fields can be expected to be tolerated. On the basis of these experimental results, it is recommended to develop new biological indicators to monitor haemopoietic cell renewal at the level of the stem cell pool using blood stem cells in addition to the determination of cytokine concentrations in the serum (and other novel approaches). To prepare for unexpected haemopoietic effects during prolonged space missions, research should be increased to modify the radiation sensitivity of haemopoietic stem cells (for instance by the application of certain regulatory molecules). In addition, a ``blood stem cell bank'' might be established for the autologous storage of stem cells and for use in space activities keeping them in a radiation protected container.

Immunological self-tolerance: Lessons from mathematical modeling

NASA Astrophysics Data System (ADS)

Carneiro, Jorge; Paixao, Tiago; Milutinovic, Dejan; Sousa, Joao; Leon, Kalet; Gardner, Rui; Faro, Jose

2005-12-01

One of the fundamental properties of the immune system is its capacity to avoid autoimmune diseases. The mechanism underlying this process, known as self-tolerance, is hitherto unresolved but seems to involve the control of clonal expansion of autoreactive lymphocytes. This article reviews mathematical modeling of self-tolerance, addressing two specific hypotheses. The first hypothesis posits that self-tolerance is mediated by tuning of activation thresholds, which makes autoreactive T lymphocytes reversibly "anergic" and unable to proliferate. The second hypothesis posits that the proliferation of autoreactive T lymphocytes is instead controlled by specific regulatory T lymphocytes. Models representing the population dynamics of autoreactive T lymphocytes according to these two hypotheses were derived. For each model we identified how cell density affects tolerance, and predicted the corresponding phase spaces and bifurcations. We show that the simple induction of proliferative anergy, as modeled here, has a density dependence that is only partially compatible with adoptive transfers of tolerance, and that the models of tolerance mediated by specific regulatory T cells are closer to the observations.

Lymphocytes from orally tolerized mice display enhanced susceptibility to death by apoptosis when cultured in the absence of antigen in vitro.

PubMed Central

Garside, P.; Steel, M.; Worthey, E. A.; Kewin, P. J.; Howie, S. E.; Harrison, D. J.; Bishop, D.; Mowat, A. M.

1996-01-01

The mechanism responsible for the induction of immunological tolerance by oral administration of soluble antigen remains unclear. Here we show that, when cultured in vitro in the absence of antigen, lymphocytes from mice tolerized with a single feed of 25 mg of ovalbumin display an enhanced mortality in comparison with cells from immunized control animals. This increased cell death affects both CD4+ and CD8+ T-lymphocyte subsets, and morphological and flow cytometric analyses suggest that it occurs via apoptosis. All of the changes associated with the propensity of tolerant cells to die by apoptosis in vitro are reduced by the inclusion of the tolerizing antigen in the cultures. These results suggest that tolerance to dietary proteins is accompanied by functional changes in T lymphocytes that render them susceptible to apoptosis. This mechanism may underlie the profound and permanent tolerance to food antigens found under physiological conditions and may provide a useful basis for immunotherapy. Images Figure 3 PMID:8952532

Plant body weight-induced secondary growth in Arabidopsis and its transcription phenotype revealed by whole-transcriptome profiling.

PubMed

Ko, Jae-Heung; Han, Kyung-Hwan; Park, Sunchung; Yang, Jaemo

2004-06-01

Wood is an important raw material and environmentally cost-effective renewable source of energy. However, the molecular biology of wood formation (i.e. secondary growth) is surprisingly understudied. A novel experimental system was employed to study the molecular regulation of secondary xylem formation in Arabidopsis. First, we demonstrate that the weight carried by the stem is a primary signal for the induction of cambium differentiation and the plant hormone, auxin, is a downstream carrier of the signal for this process. We used Arabidopsis whole-transcriptome (23 K) GeneChip analysis to examine gene expression profile changes in the inflorescent stems treated for wood formation by cultural manipulation or artificial weight application. Many of the genes up-regulated in wood-forming stems had auxin responsive cis-acting elements in their promoter region, indicating auxin-mediated regulation of secondary growth. We identified 700 genes that were differentially expressed during the transition from primary growth to secondary growth. More than 40% of the genes that were up-regulated (>5x) were associated with signal transduction and transcriptional regulation. Biological significance of these regulatory genes is discussed in light of the induction and development of secondary xylem.

The Induction Effect of Am80 and TSA on ESC Differentiation via Regulation of Stra8 in Chicken.

PubMed

Zhang, Yani; Zuo, Qisheng; Liu, Zhiyong; Li, Dong; Tang, Beibei; Xiao, Tian-Rong; Lian, Chao; Wang, Yingjie; Jin, Kai; Wang, Yilin; Zhang, Wenhui; Li, Bichun

2015-01-01

Stra8 encodes stimulated by retinoic acid gene 8, a protein that is important for initiation of meiosis in mammals and birds. This study was aimed at identifying the active control area of chicken STRA8 gene core promoter, to screen optimum inducers of the STRA8 gene, thus to enhance the differentiation of embryonic stem cells (ESCs) into spermatogonial stem cells. Fragments of chicken STRA8 gene promoter were cloned into fluorescent reporter plasmids and transfected into DF-1 cells. Then Dual-Luciferase® Reporter Assay System was used to identify the activity of the STRA8 gene under different inducers. Our studies showed that the promoter fragment -1055 bp to +54 bp of Suqin chicken Stra8 revealed the strongest activity. The dual-luciferase® reporter showed that Tamibarotene (Am80) and TrichostatinA (TSA) could significantly enhance STRA8 transcription. The in vitro inductive culture of chicken ESCs demonstrated that spermatogonial stem cells (SSC)-like cells appeared and Integrinβ1 protein was expressed on day 10, indicating that Am80 and TSA can promote ESCs differentiation into SSCs via regulation of Stra8.

The Induction Effect of Am80 and TSA on ESC Differentiation via Regulation of Stra8 in Chicken

PubMed Central

Zhang, Yani; Zuo, Qisheng; Liu, Zhiyong; Li, Dong; Tang, Beibei; Xiao, Tian-rong; Lian, Chao; Wang, Yingjie; Jin, Kai; Wang, Yilin; Zhang, Wenhui; Li, Bichun

2015-01-01

Stra8 encodes stimulated by retinoic acid gene 8, a protein that is important for initiation of meiosis in mammals and birds. This study was aimed at identifying the active control area of chicken STRA8 gene core promoter, to screen optimum inducers of the STRA8 gene, thus to enhance the differentiation of embryonic stem cells (ESCs) into spermatogonial stem cells. Fragments of chicken STRA8 gene promoter were cloned into fluorescent reporter plasmids and transfected into DF-1 cells. Then Dual-Luciferase® Reporter Assay System was used to identify the activity of the STRA8 gene under different inducers. Our studies showed that the promoter fragment −1055 bp to +54 bp of Suqin chicken Stra8 revealed the strongest activity. The dual-luciferase® reporter showed that Tamibarotene (Am80) and TrichostatinA (TSA) could significantly enhance STRA8 transcription. The in vitro inductive culture of chicken ESCs demonstrated that spermatogonial stem cells (SSC)-like cells appeared and Integrinβ1 protein was expressed on day 10, indicating that Am80 and TSA can promote ESCs differentiation into SSCs via regulation of Stra8. PMID:26606052

Nanoparticle-antagomiR based targeting of miR-31 to induce osterix and osteocalcin expression in mesenchymal stem cells.

PubMed

McCully, Mark; Conde, João; V Baptista, Pedro; Mullin, Margaret; Dalby, Matthew J; Berry, Catherine C

2018-01-01

Mesenchymal stem cells are multipotent adult stem cells capable of generating bone, cartilage and fat, and are thus currently being exploited for regenerative medicine. When considering osteogenesis, developments have been made with regards to chemical induction (e.g. differentiation media) and physical induction (e.g. material stiffness, nanotopography), targeting established early transcription factors or regulators such as runx2 or bone morphogenic proteins and promoting increased numbers of cells committing to osteo-specific differentiation. Recent research highlighted the involvement of microRNAs in lineage commitment and terminal differentiation. Herein, gold nanoparticles that confer stability to short single stranded RNAs were used to deliver MiR-31 antagomiRs to both pre-osteoblastic cells and primary human MSCs in vitro. Results showed that blocking miR-31 led to an increase in osterix protein in both cell types at day 7, with an increase in osteocalcin at day 21, suggesting MSC osteogenesis. In addition, it was noted that antagomiR sequence direction was important, with the 5 prime reading direction proving more effective than the 3 prime. This study highlights the potential that miRNA antagomiR-tagged nanoparticles offer as novel therapeutics in regenerative medicine.

Modulation Between High- and Low-Frequency Transcutaneous Electric Nerve Stimulation Delays the Development of Analgesic Tolerance in Arthritic Rats

PubMed Central

DeSantana, Josimari M.; Santana-Filho, Valter J.; Sluka, Kathleen A.

2009-01-01

Objective To investigate whether repeated administration of modulating frequency transcutaneous electric nerve stimulation (TENS) prevents development of analgesic tolerance. Design Knee joint inflammation (3% carrageenan and kaolin) was induced in rats. Either mixed or alternating frequency was administered daily (20min) for 2 weeks to the inflamed knee under light halothane anesthesia (1%–2%). Setting Laboratory. Animals Adult male Sprague-Dawley rats (N=36). Intervention Mixed- (4Hz and 100Hz) or alternating- (4Hz on 1 day; 100Hz on the next day) frequency TENS at sensory intensity and 100μs pulse duration. Main Outcome Measures Paw and joint withdrawal thresholds to mechanical stimuli were assessed before induction of inflammation, and before and after daily application of TENS. Results The reduced paw and joint withdrawal thresholds that occur 24 hours after the induction of inflammation were significantly reversed by the first administration of TENS when compared with sham treatment or to the condition before TENS treatment, which was observed through day 9. By the tenth day, repeated daily administration of either mixed- or alternating-frequency TENS did not reverse the decreased paw and joint withdrawal thresholds. Conclusions These data suggest that repeated administration of modulating frequency TENS leads to a development of opioid tolerance. However, this tolerance effect is delayed by approximately 5 days compared with administration of low- or high-frequency TENS independently. Clinically, we can infer that a treatment schedule of repeated daily TENS administration will result in a tolerance effect. Moreover, modulating low and high frequency TENS seems to produce a better analgesic effect and tolerance is slower to develop. PMID:18374009

Analysis of drought-tolerant sugar beet (Beta vulgaris L.) mutants induced with gamma radiation using SDS-PAGE and ISSR markers.

PubMed

Sen, Ayse; Alikamanoglu, Sema

2012-01-01

Drought is one of the major environmental stresses which greatly affect the plant growth and productivity. In the present study, various doses (0-75Gy) of gamma rays were applied to investigate the effect of radiation on shoot tip explants. It was observed that the regeneration rates and plant fresh weights decreased significantly with an increase in radiation dose. The optimal irradiation doses for mutation induction were determined at 15 and 20Gy. Afterwards, the induction of somatic mutation in sugar beet (Beta vulgaris L.) was investigated by irradiation of shoot tips with 15 and 20Gy gamma rays. Irradiated shoot tips were sub-cultured and M(1)V(1)-M(1)V(3) generations were obtained. Mutants tolerant to drought stress were selected on MS medium, supplemented with 10 and 20gl(-1) PEG6000. Of the M(1)V(3) plantlets, drought-tolerant mutants were selected. Leaf soluble proteins obtained from the control and drought-tolerant mutants were analyzed by SDS-PAGE. A total of 22 protein bands were determined and 2 of them were observed to be drought-tolerant mutants except the control. Polymorphism was also detected among the control and drought-tolerant mutants by DNA fingerprinting using ISSR markers. A total of 106 PCR fragments were amplified with 19 ISSR primers and 91 of them were polymorphic. The dendrograms were separated into two main clusters. First cluster included M8 mutant plant, which was applied 20Gy gamma radiation and regenerated on selective culture media containing 10gl(-1) PEG6000 concentration, and the second cluster was further divided into five sub-clusters. Copyright © 2012 Elsevier B.V. All rights reserved.

Photoperiodic regulation of the C-repeat binding factor (CBF) cold acclimation pathway and freezing tolerance in Arabidopsis thaliana.

PubMed

Lee, Chin-Mei; Thomashow, Michael F

2012-09-11

The CBF (C-repeat binding factor) pathway has a major role in plant cold acclimation, the process whereby certain plants increase in freezing tolerance in response to low nonfreezing temperatures. In Arabidopsis thaliana, the pathway is characterized by rapid cold induction of CBF1, CBF2, and CBF3, which encode transcriptional activators, followed by induction of CBF-targeted genes that impart freezing tolerance. At warm temperatures, CBF transcript levels are low, but oscillate due to circadian regulation with peak expression occurring at 8 h after dawn (zeitgeber time 8; ZT8). Here, we establish that the CBF pathway is also regulated by photoperiod at warm temperatures. At ZT8, CBF transcript levels in short-day (SD; 8-h photoperiod) plants were three- to fivefold higher than in long-day plants (LD; 16-h photoperiod). Moreover, the freezing tolerance of SD plants was greater than that of LD plants. Genetic analysis indicated that phytochrome B (PHYB) and two phytochrome-interacting factors, PIF4 and PIF7, act to down-regulate the CBF pathway and freezing tolerance under LD conditions. Down-regulation of the CBF pathway in LD plants correlated with higher PIF4 and PIF7 transcript levels and greater stability of the PIF4 and PIF7 proteins under LD conditions. Our results indicate that during the warm LD growing season, the CBF pathway is actively repressed by PHYB, PIF4, and PIF7, thus mitigating allocation of energy and nutrient resources toward unneeded frost protection. This repression is relieved by shortening day length resulting in up-regulation of the CBF pathway and increased freezing tolerance in preparation for coming cold temperatures.

Photoperiodic regulation of the C-repeat binding factor (CBF) cold acclimation pathway and freezing tolerance in Arabidopsis thaliana

PubMed Central

Lee, Chin-Mei; Thomashow, Michael F.

2012-01-01

The CBF (C-repeat binding factor) pathway has a major role in plant cold acclimation, the process whereby certain plants increase in freezing tolerance in response to low nonfreezing temperatures. In Arabidopsis thaliana, the pathway is characterized by rapid cold induction of CBF1, CBF2, and CBF3, which encode transcriptional activators, followed by induction of CBF-targeted genes that impart freezing tolerance. At warm temperatures, CBF transcript levels are low, but oscillate due to circadian regulation with peak expression occurring at 8 h after dawn (zeitgeber time 8; ZT8). Here, we establish that the CBF pathway is also regulated by photoperiod at warm temperatures. At ZT8, CBF transcript levels in short-day (SD; 8-h photoperiod) plants were three- to fivefold higher than in long-day plants (LD; 16-h photoperiod). Moreover, the freezing tolerance of SD plants was greater than that of LD plants. Genetic analysis indicated that phytochrome B (PHYB) and two phytochrome-interacting factors, PIF4 and PIF7, act to down-regulate the CBF pathway and freezing tolerance under LD conditions. Down-regulation of the CBF pathway in LD plants correlated with higher PIF4 and PIF7 transcript levels and greater stability of the PIF4 and PIF7 proteins under LD conditions. Our results indicate that during the warm LD growing season, the CBF pathway is actively repressed by PHYB, PIF4, and PIF7, thus mitigating allocation of energy and nutrient resources toward unneeded frost protection. This repression is relieved by shortening day length resulting in up-regulation of the CBF pathway and increased freezing tolerance in preparation for coming cold temperatures. PMID:22927419

Successful reversal of streptozotocin-induced diabetes with stable allogeneic islet function in a preclinical model of type 1 diabetes.

PubMed

Thomas, J M; Contreras, J L; Smyth, C A; Lobashevsky, A; Jenkins, S; Hubbard, W J; Eckhoff, D E; Stavrou, S; Neville, D M; Thomas, F T

2001-06-01

The recent focus on islet transplantation as primary therapy for type 1 diabetes has heightened interest in the reversal of type 1 diabetes in preclinical models using minimal immunosuppression. Here, we demonstrated in a preclinical rhesus model a consistent reversal of all measured glycemic patterns of streptozotocin-induced type 1 diabetes. The model used single-donor islet transplantation with induction of operational tolerance. The term "operational tolerance" is used to indicate durable survival of single-donor major histocompatibility complex (MHC)-mismatched islet allografts without maintenance immunosuppressive therapy and without rejection or loss of functional islet mass or insulin secretory reserve. In this operational tolerance model, all immunosuppression was discontinued after day 14 posttransplant, and recipients recovered with excellent health. The operational tolerance induction protocol combined peritransplant anti-CD3 immunotoxin to deplete T-cells and 15-deoxyspergualin to arrest proinflammatory cytokine production and maturation of dendritic cells. T-cell deficiency was specific but temporary, in that T-cell-dependent responses in long-term survivors recovered to normal, and there was no evidence of increased susceptibility to infection. Anti-donor mixed lymphocyte reaction responses were positive in the long-term survivors, but all showed clear evidence of systemic T-helper 2 deviation, suggesting that an immunoregulatory rather than a deletional process underlies this operational tolerance model. This study provides the first evidence that operational tolerance can protect MHC nonhuman primate islets from rejection as well as loss of functional islet mass. Such an approach has potential to optimize individual recipient recovery from diabetes as well as permitting more widespread islet transplantation with the limited supply of donor islets.

[A comparative study on inducing non-homologous mesenchymal stem cells to differentiate into neural stem cells using non-homologous cerebrospinal fluid].

PubMed

Ren, Chao; Liu, Xiaoyun; Wan, Meirong; Geng, Deqin; Ge, Wei; Li, Jinmei; Zhang, Weiwei

2013-12-01

In order to set up a base for stem cells to be widely used in clinical medicine, we tried to optimize, in this study, the technique that induces human mesenchymal stem cells (hMSCs) to differentiate into neural stem cells by using cerebrospinal fluid (CSF) from the different groups. After the induction, presence of neural stem cells was confirmed with microscope observation, flow cytometry analysis, immunohistochemistry and fluorescent immunohistochemistry. At the same time, we also compared and analysed the data of the number of stem cells when it totally met the requirements for clinical treatment and the days required. At last, we confirmed that hMSCs could be induced to differentiate into neural stem cells, and that the number of cells totally met the requirements for clinical treatment. But there were some differences both in the number of cells and the days required. Among the groups, the group that marrow mesenchymal stem cells from patients own induced by CSF from healthy volunteers used the shortest time and the quantity of the cells was significantly higher than those of the others.

Mammalian genes induce partially reprogrammed pluripotent stem cells in non-mammalian vertebrate and invertebrate species

PubMed Central

Rosselló, Ricardo Antonio; Chen, Chun-Chun; Dai, Rui; Howard, Jason T; Hochgeschwender, Ute; Jarvis, Erich D

2013-01-01

Cells are fundamental units of life, but little is known about evolution of cell states. Induced pluripotent stem cells (iPSCs) are once differentiated cells that have been re-programmed to an embryonic stem cell-like state, providing a powerful platform for biology and medicine. However, they have been limited to a few mammalian species. Here we found that a set of four mammalian transcription factor genes used to generate iPSCs in mouse and humans can induce a partially reprogrammed pluripotent stem cell (PRPSCs) state in vertebrate and invertebrate model organisms, in mammals, birds, fish, and fly, which span 550 million years from a common ancestor. These findings are one of the first to show cross-lineage stem cell-like induction, and to generate pluripotent-like cells for several of these species with in vivo chimeras. We suggest that the stem-cell state may be highly conserved across a wide phylogenetic range. DOI: http://dx.doi.org/10.7554/eLife.00036.001 PMID:24015354

Factors enhancing the migration and the homing of mesenchymal stem cells in experimentally induced cardiotoxicity in rats.

PubMed

A Soliman, Nabil; Abd-Allah, Somia H; Hussein, Samia; Alaa Eldeen, Muhammad

2017-03-01

Doxorubicin is an effective anti-neoplastic drug but its use is limited by its cardiotoxicity. Administration of mesenchymal stem cells (MSCs) for the management of cardiotoxicity was with poor myocardial homing capacity. With the aim of developing novel techniques to improve the migration of MSCs, we tested whether valproate and electric fields (EFs) direct the migration of MSCs towards the damaged myocardium. The study included five groups of female albino rats. The first group included 10 healthy rats as normal control group. The remaining 40 female rats received doxorubicin for induction of acute cardiotoxicity. Four rats were sacrificed for histopathological confirmation of cardiotoxicity. The remaining rats were equally divided into subsequent four groups. The second group included nine rats that did not receive further treatment (positive control group). The third group included nine rats which received intravenous bone marrow derived mesenchymal stem cells (BM-MSCs) after cardiotoxicity induction. The fourth group included nine rats which received BM-MSCs plus sodium valporate after cardiotoxicity induction. The fifth group included nine rats which received BM-MSCs plus sodium valporate after cardiotoxicity induction and were exposed to an electrical stimulation (ES). Blood samples were taken from all groups at the end of the study to estimate creatine kinase-MB (CK-MB), aspartate transaminase (AST) and lactate dehydrogenase (LDH). Heart tissues from all rats were used for RNA extraction for assessment of sry gene expression. Homing was tested by PKH26 fluorescence in myocardial tissue sections and by sry gene expression. The best biochemical and histopathological improvement in cardiotoxicity was demonstrated in group 5 (rats that received ES and valporate with MSCs). We concluded that EFs and sodium valproate enhance homing ability of MSCs towards the damaged myocardium in doxorubicin induced carditoxicity model. © 2017 IUBMB Life, 69(3):162-169, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

Cyclophosphamide, thalidomide, and dexamethasone as induction therapy for newly diagnosed multiple myeloma patients destined for autologous stem-cell transplantation: MRC Myeloma IX randomized trial results

PubMed Central

Morgan, Gareth J.; Davies, Faith E.; Gregory, Walter M.; Bell, Sue E.; Szubert, Alexander J.; Navarro Coy, Nuria; Cook, Gordon; Feyler, Sylvia; Johnson, Peter R.E.; Rudin, Claudius; Drayson, Mark T.; Owen, Roger G.; Ross, Fiona M.; Russell, Nigel H.; Jackson, Graham H.; Child, J. Anthony

2012-01-01

Background Thalidomide is active in multiple myeloma and is associated with minimal myelosuppression, making it a good candidate for induction therapy prior to high-dose therapy with autologous stem-cell transplantation. Design and Methods Oral cyclophosphamide, thalidomide, and dexamethasone was compared with infusional cyclophosphamide, vincristine, doxorubicin, and dexamethasone in patients with newly diagnosed multiple myeloma. Results The post-induction overall response rate (≥ partial response) for the intent-to-treat population was significantly higher with cyclophosphamide-thalidomide-dexamethasone (n=555) versus cyclophosphamide-vincristine-doxorubicin-dexamethasone (n=556); 82.5% versus 71.2%; odds ratio 1.91; 95% confidence interval 1.44–2.55; P<0.0001. The complete response rates were 13.0% with cyclophosphamide-thalidomide-dexamethasone and 8.1% with cyclophos-phamide-vincristine-doxorubicin-dexamethasone (P=0.0083), with this differential response being maintained in patients who received autologous stem-cell transplantation (post-transplant complete response 50.0% versus 37.2%, respectively; P=0.00052). Cyclophosphamide-thalidomide-dexamethasone was non-inferior to cyclophosphamide-vincristine-doxorubicin-dexamethasone for progression-free and overall survival, and there was a trend toward a late survival benefit with cyclophosphamide-thalidomide-dexamethasone in responders. A trend toward an overall survival advantage for cyclophosphamide-thalidomide-dexamethasone over cyclophosphamide-vincristine-doxorubicin-dexamethasone was also observed in a subgroup of patients with favorable interphase fluorescence in situ hybridization. Compared with cyclophosphamide-vincristine-doxorubicin-dexamethasone, cyclophosphamide-thalidomide-dexamethasone was associated with more constipation and somnolence, but a lower incidence of cytopenias. Conclusions The cyclophosphamide-thalidomide-dexamethasone regimen showed improved response rates and was not inferior in terms of survival outcomes to the standard infusional regimen of cyclophosphamide-vincristine-doxorubicin-dexamethasone. Based on its oral administration and the reduced incidence of infection and cytopenia, cyclophosphamide-thalidomide-dexa-methasone may be considered an effective induction therapy option for patients with newly diagnosed multiple myeloma. (ISRCTN: 68454111) PMID:22058209

Differentiation of human umbilical cord mesenchymal stem cells into dermal fibroblasts in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Yanfu; Chai, Jiake, E-mail: cjk304@126.com; Sun, Tianjun

2011-10-07

Highlights: {yields} Mesenchymal stem cells (MSCs) are potential seed cells for tissue-engineered skin. {yields} Tissue-derived umbilical cord MSCs (UCMSCs) can readily be isolated in vitro. {yields} We induce UCMSCs to differentiate into dermal fibroblasts via conditioned medium. {yields} Collagen type I and collagen type III mRNA level was higher in differentiated cells. {yields} UCMSCs-derived fibroblast-like cells strongly express fibroblast-specific protein. -- Abstract: Tissue-derived umbilical cord mesenchymal stem cells (UCMSCs) can be readily obtained, avoid ethical or moral constraints, and show excellent pluripotency and proliferation potential. UCMSCs are considered to be a promising source of stem cells in regenerative medicine. Inmore » this study, we collected newborn umbilical cord tissue under sterile conditions and isolated UCMSCs through a tissue attachment method. UCMSC cell surface markers were examined using flow cytometry. On the third passage, UCMSCs were induced to differentiate into dermal fibroblasts in conditioned induction media. The induction results were detected using immunofluorescence with a fibroblast-specific monoclonal antibody and real time PCR for type I and type III collagen. UCMSCs exhibited a fibroblast-like morphology and reached 90% confluency 14 to 18 days after primary culture. Cultured UCMSCs showed strong positive staining for CD73, CD29, CD44, CD105, and HLA-I, but not CD34, CD45, CD31, or HLA-DR. After differentiation, immunostaining for collagen type I, type III, fibroblast-specific protein, vimentin, and desmin were all strongly positive in induced cells, and staining was weak or negative in non-induced cells; total transcript production of collagen type I and collagen type III mRNA was higher in induced cells than in non-induced cells. These results demonstrate that UCMSCs can be induced to differentiate into fibroblasts with conditioned induction media and, in turn, could be used as seed cells for tissue-engineered dermis.« less

Improved osteogenesis and upregulated immunogenicity in human placenta-derived mesenchymal stem cells primed with osteogenic induction medium.

PubMed

Fu, Xuejie; Yang, Huilin; Zhang, Hui; Wang, Guichao; Liu, Ke; Gu, Qiaoli; Tao, Yunxia; Chen, Guangcun; Jiang, Xiaohua; Li, Gang; Gu, Yanzheng; Shi, Qin

2016-09-20

Mesenchymal stem cells (MSCs) are widely used in cell-based therapy owing to their multilineage potential and low immunogenicity. However, low differentiation efficiency and unpredictable immunogenicity of allogeneic MSCs in vivo limit their success in therapeutic treatment. Herein, we evaluated the differentiation potential and immunogenicity of human placenta-derived MSCs manipulated with osteogenic priming and dedifferentiation process. MSCs from human placentas were subjected to osteogenic induction and then cultivated in osteogenic factor-free media; the obtained cell population was termed dedifferentiated mesenchymal stem cells (De-MSCs). De-MSCs were induced into osteo-, chondro- and adipo-differentiation in vitro. Cell proliferation was quantified by a Cell-Counting Kit-8 or tritiated thymidine ([(3)H]-TdR) incorporation. Meanwhile, the osteogenesis of De-MSCs in vivo was assayed by real-time PCR and histological staining. The expressions of stem cell markers and co-stimulatory molecules on De-MSCs and lymphocytes from primed BALB/c mouse with De-MSCs were determined by flow cytometry. De-MSCs exhibited some properties similar to MSCs including multiple differentiation potential and hypoimmunogenicity. Upon re-osteogenic induction, De-MSCs exhibited higher differentiation capability than MSCs both in vitro and in vivo. Of note, De-MSCs had upregulated immunogenicity in association with their osteogenesis, reflected by the alternated expressions of co-stimulatory molecules on the surface and decreased suppression on T cell activation. Functionally, De-MSC-derived osteoblasts could prime lymphocytes of peripheral blood and spleen in BALB/c mice in vivo. These data are of great significance for the potential application of De-MSCs as an alternative resource for regenerative medicine and tissue engineering. In order to avoid being rejected by the host during allogeneic De-MSC therapy, we suggest that immune intervention should be considered to boost the immune acceptance and integration because of the upregulated immunogenicity of De-MSCs with redifferentiation in clinical applications.

Synchrotron-Based Techniques Shed Light on Mechanisms of Plant Sensitivity and Tolerance to High Manganese in the Root Environment.

PubMed

Blamey, F Pax C; Hernandez-Soriano, Maria C; Cheng, Miaomiao; Tang, Caixian; Paterson, David J; Lombi, Enzo; Wang, Wei Hong; Scheckel, Kirk G; Kopittke, Peter M

2015-11-01

Plant species differ in response to high available manganese (Mn), but the mechanisms of sensitivity and tolerance are poorly understood. In solution culture, greater than or equal to 30 µm Mn decreased the growth of soybean (Glycine max), but white lupin (Lupinus albus), narrow-leafed lupin (Lupin angustifolius), and sunflower (Helianthus annuus) grew well at 100 µm Mn. Differences in species' tolerance to high Mn could not be explained simply by differences in root, stem, or leaf Mn status, being 8.6, 17.1, 6.8, and 9.5 mmol kg(-1) leaf fresh mass at 100 µm Mn. Furthermore, x-ray absorption near edge structure analyses identified the predominance of Mn(II), bound mostly to malate or citrate, in roots and stems of all four species. Rather, differences in tolerance were due to variations in Mn distribution and speciation within leaves. In Mn-sensitive soybean, in situ analysis of fresh leaves using x-ray fluorescence microscopy combined with x-ray absorption near edge structure showed high Mn in the veins, and manganite [Mn(III)] accumulated in necrotic lesions apparently through low Mn sequestration in vacuoles or other vesicles. In the two lupin species, most Mn accumulated in vacuoles as either soluble Mn(II) malate or citrate. In sunflower, Mn was sequestered as manganite at the base of nonglandular trichomes. Hence, tolerance to high Mn was ascribed to effective sinks for Mn in leaves, as Mn(II) within vacuoles or through oxidation of Mn(II) to Mn(III) in trichomes. These two mechanisms prevented Mn accumulation in the cytoplasm and apoplast, thereby ensuring tolerance to high Mn in the root environment. © 2015 American Society of Plant Biologists. All Rights Reserved.

Synchrotron-Based Techniques Shed Light on Mechanisms of Plant Sensitivity and Tolerance to High Manganese in the Root Environment1[OPEN

PubMed Central

Blamey, F. Pax C.; Hernandez-Soriano, Maria C.; Cheng, Miaomiao; Tang, Caixian; Paterson, David J.; Lombi, Enzo; Wang, Wei Hong; Scheckel, Kirk G.; Kopittke, Peter M.

2015-01-01

Plant species differ in response to high available manganese (Mn), but the mechanisms of sensitivity and tolerance are poorly understood. In solution culture, greater than or equal to 30 µm Mn decreased the growth of soybean (Glycine max), but white lupin (Lupinus albus), narrow-leafed lupin (Lupin angustifolius), and sunflower (Helianthus annuus) grew well at 100 µm Mn. Differences in species’ tolerance to high Mn could not be explained simply by differences in root, stem, or leaf Mn status, being 8.6, 17.1, 6.8, and 9.5 mmol kg–1 leaf fresh mass at 100 µm Mn. Furthermore, x-ray absorption near edge structure analyses identified the predominance of Mn(II), bound mostly to malate or citrate, in roots and stems of all four species. Rather, differences in tolerance were due to variations in Mn distribution and speciation within leaves. In Mn-sensitive soybean, in situ analysis of fresh leaves using x-ray fluorescence microscopy combined with x-ray absorption near edge structure showed high Mn in the veins, and manganite [Mn(III)] accumulated in necrotic lesions apparently through low Mn sequestration in vacuoles or other vesicles. In the two lupin species, most Mn accumulated in vacuoles as either soluble Mn(II) malate or citrate. In sunflower, Mn was sequestered as manganite at the base of nonglandular trichomes. Hence, tolerance to high Mn was ascribed to effective sinks for Mn in leaves, as Mn(II) within vacuoles or through oxidation of Mn(II) to Mn(III) in trichomes. These two mechanisms prevented Mn accumulation in the cytoplasm and apoplast, thereby ensuring tolerance to high Mn in the root environment. PMID:26395840

Formation of Stomach Tissue by Organoid Culture Using Mouse Embryonic Stem Cells.

PubMed

Noguchi, Taka-Aki K; Kurisaki, Akira

2017-01-01

In this chapter, we describe a method for the induction of stomach organoids from mouse embryonic stem (ES) cells. We used an embryoid body-based differentiation method to induce gastric primordial epithelium covered with mesenchyme and further differentiate it in Matrigel by 3D culture. The differentiated organoid contains both corpus- and antrum-specific mature gastric tissue cells. This protocol may be useful for a variety of studies in developmental biology and disease modeling of the stomach.

Directing Stem Cell Differentiation via Electrochemical Reversible Switching between Nanotubes and Nanotips of Polypyrrole Array.

PubMed

Wei, Yan; Mo, Xiaoju; Zhang, Pengchao; Li, Yingying; Liao, Jingwen; Li, Yongjun; Zhang, Jinxing; Ning, Chengyun; Wang, Shutao; Deng, Xuliang; Jiang, Lei

2017-06-27

Control of stem cell behaviors at solid biointerfaces is critical for stem-cell-based regeneration and generally achieved by engineering chemical composition, topography, and stiffness. However, the influence of dynamic stimuli at the nanoscale from solid biointerfaces on stem cell fate remains unclear. Herein, we show that electrochemical switching of a polypyrrole (Ppy) array between nanotubes and nanotips can alter surface adhesion, which can strongly influence mechanotransduction activation and guide differentiation of mesenchymal stem cells (MSCs). The Ppy array, prepared via template-free electrochemical polymerization, can be reversibly switched between highly adhesive hydrophobic nanotubes and poorly adhesive hydrophilic nanotips through an electrochemical oxidation/reduction process, resulting in dynamic attachment and detachment to MSCs at the nanoscale. Multicyclic attachment/detachment of the Ppy array to MSCs can activate intracellular mechanotransduction and osteogenic differentiation independent of surface stiffness and chemical induction. This smart surface, permitting transduction of nanoscaled dynamic physical inputs into biological outputs, provides an alternative to classical cell culture substrates for regulating stem cell fate commitment. This study represents a general strategy to explore nanoscaled interactions between stem cells and stimuli-responsive surfaces.

Expansion of Multipotent Stem Cells from the Adult Human Brain

PubMed Central

Murrell, Wayne; Palmero, Emily; Bianco, John; Stangeland, Biljana; Joel, Mrinal; Paulson, Linda; Thiede, Bernd; Grieg, Zanina; Ramsnes, Ingunn; Skjellegrind, Håvard K.; Nygård, Ståle; Brandal, Petter; Sandberg, Cecilie; Vik-Mo, Einar; Palmero, Sheryl; Langmoen, Iver A.

2013-01-01

The discovery of stem cells in the adult human brain has revealed new possible scenarios for treatment of the sick or injured brain. Both clinical use of and preclinical research on human adult neural stem cells have, however, been seriously hampered by the fact that it has been impossible to passage these cells more than a very few times and with little expansion of cell numbers. Having explored a number of alternative culturing conditions we here present an efficient method for the establishment and propagation of human brain stem cells from whatever brain tissue samples we have tried. We describe virtually unlimited expansion of an authentic stem cell phenotype. Pluripotency proteins Sox2 and Oct4 are expressed without artificial induction. For the first time multipotency of adult human brain-derived stem cells is demonstrated beyond tissue boundaries. We characterize these cells in detail in vitro including microarray and proteomic approaches. Whilst clarification of these cells’ behavior is ongoing, results so far portend well for the future repair of tissues by transplantation of an adult patient’s own-derived stem cells. PMID:23967194

Genetically induced cell death in bulge stem cells reveals their redundancy for hair and epidermal regeneration.

PubMed

Driskell, Iwona; Oeztuerk-Winder, Feride; Humphreys, Peter; Frye, Michaela

2015-03-01

Adult mammalian epidermis contains multiple stem cell populations in which quiescent and more proliferative stem and progenitor populations coexist. However, the precise interrelation of these populations in homeostasis remains unclear. Here, we blocked the contribution of quiescent keratin 19 (K19)-expressing bulge stem cells to hair follicle formation through genetic ablation of the essential histone methyltransferase Setd8 that is required for the maintenance of adult skin. Deletion of Setd8 eliminated the contribution of bulge cells to hair follicle regeneration through inhibition of cell division and induction of cell death, but the growth and morphology of hair follicles were unaffected. Furthermore, ablation of Setd8 in the hair follicle bulge blocked the contribution of K19-postive stem cells to wounded epidermis, but the wound healing process was unaltered. Our data indicate that quiescent bulge stem cells are dispensable for hair follicle regeneration and epidermal injury in the short term and support the hypothesis that quiescent and cycling stem cell populations are equipotent. © 2014 AlphaMed Press.

Muscle Stem Cells Undergo Extensive Clonal Drift during Tissue Growth via Meox1-Mediated Induction of G2 Cell-Cycle Arrest.

PubMed

Nguyen, Phong Dang; Gurevich, David Baruch; Sonntag, Carmen; Hersey, Lucy; Alaei, Sara; Nim, Hieu Tri; Siegel, Ashley; Hall, Thomas Edward; Rossello, Fernando Jaime; Boyd, Sarah Elizabeth; Polo, Jose Maria; Currie, Peter David

2017-07-06

Organ growth requires a careful balance between stem cell self-renewal and lineage commitment to ensure proper tissue expansion. The cellular and molecular mechanisms that mediate this balance are unresolved in most organs, including skeletal muscle. Here we identify a long-lived stem cell pool that mediates growth of the zebrafish myotome. This population exhibits extensive clonal drift, shifting from random deployment of stem cells during development to reliance on a small number of dominant clones to fuel the vast majority of muscle growth. This clonal drift requires Meox1, a homeobox protein that directly inhibits the cell-cycle checkpoint gene ccnb1. Meox1 initiates G 2 cell-cycle arrest within muscle stem cells, and disrupting this G 2 arrest causes premature lineage commitment and the resulting defects in muscle growth. These findings reveal that distinct regulatory mechanisms orchestrate stem cell dynamics during organ growth, beyond the G 0 /G 1 cell-cycle inhibition traditionally associated with maintaining tissue-resident stem cells. Copyright © 2017. Published by Elsevier Inc.

Attenuated microglial activation mediates tolerance to the neurotoxic effects of methamphetamine.

PubMed

Thomas, David M; Kuhn, Donald M

2005-02-01

Methamphetamine causes persistent damage to dopamine nerve endings of the striatum. Repeated, intermittent treatment of mice with low doses of methamphetamine leads to the development of tolerance to its neurotoxic effects. The mechanisms underlying tolerance are not understood but clearly involve more than alterations in drug bioavailability or reductions in the hyperthermia caused by methamphetamine. Microglia have been implicated recently as mediators of methamphetamine-induced neurotoxicity. The purpose of the present studies was to determine if a tolerance regimen of methamphetamine would attenuate the microglial response to a neurotoxic challenge. Mice treated with a low-dose methamphetamine tolerance regimen showed minor reductions in striatal dopamine content and low levels of microglial activation. When the tolerance regimen preceded a neurotoxic challenge of methamphetamine, the depletion of dopamine normally seen was significantly attenuated. The microglial activation that occurs after a toxic methamphetamine challenge was blunted likewise. Despite the induction of tolerance against drug-induced toxicity and microglial activation, a neurotoxic challenge with methamphetamine still caused hyperthermia. These results suggest that tolerance to methamphetamine neurotoxicity is associated with attenuated microglial activation and they further dissociate its neurotoxicity from drug-induced hyperthermia.

Heat Shock Proteins in Association with Heat Tolerance in Grasses

PubMed Central

Xu, Yan; Zhan, Chenyang; Huang, Bingru

2011-01-01

The grass family Poaceae includes annual species cultivated as major grain crops and perennial species cultivated as forage or turf grasses. Heat stress is a primary factor limiting growth and productivity of cool-season grass species and is becoming a more significant problem in the context of global warming. Plants have developed various mechanisms in heat-stress adaptation, including changes in protein metabolism such as the induction of heat shock proteins (HSPs). This paper summarizes the structure and function of major HSPs, recent research progress on the association of HSPs with grass tolerance to heat stress, and incorporation of HSPs in heat-tolerant grass breeding. PMID:22084689

Ecosystem Engineering by Plants on Wave-Exposed Intertidal Flats Is Governed by Relationships between Effect and Response Traits.

PubMed

Heuner, Maike; Silinski, Alexandra; Schoelynck, Jonas; Bouma, Tjeerd J; Puijalon, Sara; Troch, Peter; Fuchs, Elmar; Schröder, Boris; Schröder, Uwe; Meire, Patrick; Temmerman, Stijn

2015-01-01

In hydrodynamically stressful environments, some species--known as ecosystem engineers--are able to modify the environment for their own benefit. Little is known however, about the interaction between functional plant traits and ecosystem engineering. We studied the responses of Scirpus tabernaemontani and Scirpus maritimus to wave impact in full-scale flume experiments. Stem density and biomass were used to predict the ecosystem engineering effect of wave attenuation. Also the drag force on plants, their bending angle after wave impact and the stem biomechanical properties were quantified as both responses of stress experienced and effects on ecosystem engineering. We analyzed lignin, cellulose, and silica contents as traits likely effecting stress resistance (avoidance, tolerance). Stem density and biomass were strong predictors for wave attenuation, S. maritimus showing a higher effect than S. tabernaemontani. The drag force and drag force per wet frontal area both differed significantly between the species at shallow water depths (20 cm). At greater depths (35 cm), drag forces and bending angles were significantly higher for S. maritimus than for S. tabernaemontani. However, they do not differ in drag force per wet frontal area due to the larger plant surface of S. maritimus. Stem resistance to breaking and stem flexibility were significantly higher in S. tabernaemontani, having a higher cellulose concentration and a larger cross-section in its basal stem parts. S. maritimus had clearly more lignin and silica contents in the basal stem parts than S. tabernaemontani. We concluded that the effect of biomass seems more relevant for the engineering effect of emergent macrophytes with leaves than species morphology: S. tabernaemontani has avoiding traits with minor effects on wave attenuation; S. maritimus has tolerating traits with larger effects. This implies that ecosystem engineering effects are directly linked with traits affecting species stress resistance and responding to stress experienced.

Ecosystem Engineering by Plants on Wave-Exposed Intertidal Flats Is Governed by Relationships between Effect and Response Traits

PubMed Central

Schoelynck, Jonas; Bouma, Tjeerd J.; Puijalon, Sara; Troch, Peter; Fuchs, Elmar; Schröder, Boris; Schröder, Uwe; Meire, Patrick; Temmerman, Stijn

2015-01-01

In hydrodynamically stressful environments, some species—known as ecosystem engineers—are able to modify the environment for their own benefit. Little is known however, about the interaction between functional plant traits and ecosystem engineering. We studied the responses of Scirpus tabernaemontani and Scirpus maritimus to wave impact in full-scale flume experiments. Stem density and biomass were used to predict the ecosystem engineering effect of wave attenuation. Also the drag force on plants, their bending angle after wave impact and the stem biomechanical properties were quantified as both responses of stress experienced and effects on ecosystem engineering. We analyzed lignin, cellulose, and silica contents as traits likely effecting stress resistance (avoidance, tolerance). Stem density and biomass were strong predictors for wave attenuation, S. maritimus showing a higher effect than S. tabernaemontani. The drag force and drag force per wet frontal area both differed significantly between the species at shallow water depths (20 cm). At greater depths (35 cm), drag forces and bending angles were significantly higher for S. maritimus than for S. tabernaemontani. However, they do not differ in drag force per wet frontal area due to the larger plant surface of S. maritimus. Stem resistance to breaking and stem flexibility were significantly higher in S. tabernaemontani, having a higher cellulose concentration and a larger cross-section in its basal stem parts. S. maritimus had clearly more lignin and silica contents in the basal stem parts than S. tabernaemontani. We concluded that the effect of biomass seems more relevant for the engineering effect of emergent macrophytes with leaves than species morphology: S. tabernaemontani has avoiding traits with minor effects on wave attenuation; S. maritimus has tolerating traits with larger effects. This implies that ecosystem engineering effects are directly linked with traits affecting species stress resistance and responding to stress experienced. PMID:26367004

Chronic free-choice drinking in crossed high alcohol preferring mice leads to sustained blood ethanol levels and metabolic tolerance without evidence of liver damage.

PubMed

Matson, Liana; Liangpunsakul, Suthat; Crabb, David; Buckingham, Amy; Ross, Ruth Ann; Halcomb, Meredith; Grahame, Nicholas

2013-02-01

Crossed high alcohol preferring (cHAP) mice were selectively bred from a cross of the HAP1 × HAP2 replicate lines, and we demonstrate blood ethanol concentrations (BECs) during free-choice drinking that are reminiscent of those observed in alcohol-dependent humans. Therefore, this line may provide an unprecedented opportunity to learn about the consequences of excessive voluntary ethanol (EtOH) consumption, including metabolic tolerance and liver pathology. Cytochrome p450 2E1 (CYP2E1) induction plays a prominent role in driving both metabolic tolerance and EtOH-induced liver injury. In this report, we sought to characterize cHAP drinking by assessing whether pharmacologically relevant BEC levels are sustained throughout the active portion of the light-dark cycle. Given that cHAP intakes and BECs are similar to those observed in mice given an EtOH liquid diet, we assessed whether free-choice exposure results in metabolic tolerance, hepatic enzyme induction, and hepatic steatosis. In experiment 1, blood samples were taken across the dark portion of a 12:12 light-dark cycle to examine the pattern of EtOH accumulation in these mice. In experiments 1 and 2, mice were injected with EtOH following 3 to 4 weeks of access to water or 10% EtOH and water, and blood samples were taken to assess metabolic tolerance. In experiment 3, 24 mice had 4 weeks of access to 10% EtOH and water or water alone, followed by necropsy and hepatological assessment. In experiment 1, cHAP mice mean BEC values exceeded 80 mg/dl at all sampling points and approached 200 mg/dl during the middle of the dark cycle. In experiments 1 and 2, EtOH-exposed mice metabolized EtOH faster than EtOH-naïve mice, demonstrating metabolic tolerance (p < 0.05). In experiment 3, EtOH-drinking mice showed greater expression of hepatic CYP2E1 than water controls, consistent with the development of metabolic tolerance (p < 0.05). EtOH access altered neither hepatic histology nor levels of alcohol dehydrogenase and aldehyde dehydrogenase. These results demonstrate that excessive intake by cHAP mice results in sustained BECs throughout the active period, leading to the development of metabolic tolerance and evidence of CYP2E1 induction. Together, these results provide additional support for the cHAP mice as a highly translational rodent model of alcoholism. Copyright © 2012 by the Research Society on Alcoholism.

Heavy metals in aromatic spices by inductively coupled plasma-mass spectrometry.

PubMed

Bua, Daniel Giuseppe; Annuario, Giovanni; Albergamo, Ambrogina; Cicero, Nicola; Dugo, Giacomo

2016-09-01

Objective of this study was to determine the content of Cd, Hg, As and Pb in common spices traded in the Italian market, using inductively coupled plasma-mass spectrometry (ICP-MS). The results were compared with the maximum limits established by the national Legislative Decree (LD) no. 107 implementing the Council Directive 88/388/EEC and by international organisations, such as Food and Agriculture Organization (FAO) and World Health Organization (WHO). Food safety for spices was assessed considering the tolerable weekly intake (TWI) and the provisional tolerable weekly intake (PTWI), respectively, for Cd and Hg and the 95% lower confidence limit of the benchmark dose of 1% extra risk (BMDL01) for As and Pb. Investigated elements in all samples were within the maximum limits as set by the national and international normative institutions. Nevertheless, the heavy metal content of some spices exceeded the PTWI, TWI and BMDL01, which needs attention when considering consumer's health.

Longitudinal Studies of a B Cell Derived Signature of Tolerance in Renal Transplant Recipients

PubMed Central

Newell, Kenneth A.; Asare, Adam; Sanz, Ignacio; Wei, Chungwen; Rosenberg, Alexander; Gao, Zhong; Kanaparthi, Sai; Asare, Smita; Lim, Noha; Stahly, Michael; Howell, Michael; Knechtle, Stuart; Kirk, Allan; Marks, William H.; Kawai, Tatsuo; Spitzer, Thomas; Tolkoff-Rubin, Nina; Sykes, Megan; Sachs, David H.; Cosimi, A. Benedict; Burlingham, William J.; Phippard, Deborah; Turka, Laurence A.

2016-01-01

Biomarkers of transplant tolerance would enhance the safety and feasibility of clinical tolerance trials and potentially facilitate management of patients receiving immunosuppression. To this end, we examined blood from spontaneously tolerant renal transplant recipients and patients enrolled in two interventional tolerance trials using flow cytometry and gene expression profiling. Using a previously reported tolerant cohort as well as newly identified tolerant patients we confirmed our previous finding that tolerance was associated with increased expression of B cell-associated genes relative to immunosuppressed patients. This was not accounted for merely by an increase in total B cell numbers, but was associated with the increased frequencies of transitional and naïve B cells. Moreover, serial measurements of gene expression demonstrated that this pattern persisted over several years although patients receiving immunosuppression also displayed an increase in the two most dominant tolerance-related B cell genes, IGKV1D-13 and IGLL-1, over time. Importantly, patients rendered tolerant via induction of transient mixed chimerism, and those weaned to minimal immunosuppression, showed similar increases in IGKV1D-13 as did spontaneously tolerant individuals. Collectively, these findings support the notion that alterations in B cells may be a common theme for tolerant kidney transplant recipients, and a useful monitoring tool in prospective trials. PMID:26461968

A multifaceted assessment of emotional tolerance and intensity in hoarding.

PubMed

Timpano, Kiara R; Shaw, Ashley M; Cougle, Jesse R; Fitch, Kristin E

2014-09-01

Hoarding is characterized by emotionally reinforced saving behaviors, which often combine with excessive acquisition to give rise to clutter, distress, and impairment. Despite the central role emotional processes are thought to play in hoarding, very little research has directly examined this topic. There is suggestive evidence linking hoarding with several facets of emotional intolerance and avoidance, though one key limitation of this past research has been the exclusive reliance on self-report questionnaires. The aim of the current study was to conduct a multimethod investigation of the relationship between hoarding and perceptions of, and cognitions about, negative emotional states. A large unselected sample of nonclinical young adults (N=213) completed questionnaires, behavioral tasks, and a series of negative mood inductions to assess distress tolerance (DT), appraisals of negative emotions, and emotional intensity and tolerance. Hoarding symptoms were associated with lowered tolerance of negative emotions, as well as perceiving negative emotions as more threatening. Individuals high in hoarding symptoms also experienced more intense emotions during the mood inductions than individuals low in hoarding symptoms, though there was no association with poorer performance on a behavioral index of DT. Across measures, hoarding was consistently associated with experiencing negative emotions more intensely and reporting lower tolerance of them. This relationship was particularly pronounced for the difficulty discarding and acquiring facets of hoarding. Our results offer initial support for the important role of emotional processes in the cognitive-behavioral model of hoarding. A better understanding of emotional dysfunction may play a crucial role in developing more effective treatments for hoarding. Copyright © 2014. Published by Elsevier Ltd.

Competition of tolerant strategies in the spatial public goods game

NASA Astrophysics Data System (ADS)

Szolnoki, Attila; Perc, Matjaž

2016-08-01

Tolerance implies enduring trying circumstances with a fair and objective attitude. To determine whether evolutionary advantages might be stemming from diverse levels of tolerance in a population, we study a spatial public goods game, where in addition to cooperators, defectors, and loners, tolerant players are also present. Depending on the number of defectors within a group, a tolerant player can either cooperate in or abstain from a particular instance of the game. We show that the diversity of tolerance can give rise to synergistic effects, wherein players with a different threshold in terms of the tolerated number of defectors in a group compete most effectively against defection and default abstinence. Such synergistic associations can stabilise states of full cooperation where otherwise defection would dominate. We observe complex pattern formation that gives rise to an intricate phase diagram, where invisible yet stable strategy alliances require outmost care lest they are overlooked. Our results highlight the delicate importance of diversity and tolerance for the provisioning of public goods, and they reveal fascinating subtleties of the spatiotemporal dynamics that is due to the competition of subsystem solutions in structured populations.

Genetic variability in sublethal tolerance to mixtures of cadmium and zinc in clones of Daphnia magna Straus.

PubMed

Barata, Carlos; Markich, Scott J; Baird, Donald J; Taylor, Graeme; Soares, Amadeu M V M

2002-10-02

To date, studies on genetic variability in the tolerance of aquatic biota to chemicals have focused on exposure to single chemicals. In the field, metals occur as elemental mixtures, and thus it is essential to study whether the genetic consequences of exposure to such mixtures differs from response to single chemicals. This study determined the feeding responses of three Daphnia magna Straus clones exposed to Cd and Zn, both individually and as mixtures. Tolerance to mixtures of Cd and Zn was expressed as the proportional feeding depression of D. magna to Cd at increasing zinc concentrations. A quantitative genetic analysis revealed that genotype and genotype x environmental factors governed population responses to mixtures of both metals. More specifically, genetic variation in tolerance to sublethal levels of Cd decreased at those Zn concentrations where there were no effects on feeding, and increased again at Zn concentrations that affected feeding. The existence of genotype x environmental interactions indicated that the genetic consequences of exposing D. magna to mixtures of Cd and Zn cannot be predicted from the animals' response to single metals alone. Therefore, current ecological risk assessment methodologies for predicting the effects of chemical mixtures may wish to incorporate the concept of genetic variability. Furthermore, exposure to low and moderate concentrations of Zn increased the sublethal tolerance to Cd. This induction of tolerance to Cd by Zn was also observed for D. magna fed algae pre-loaded with both metals. Furthermore, in only one clone, physiological acclimatization to zinc also induced tolerance to cadmium. These results suggest that the feeding responses of D. magna may be related to gut poisoning induced by the release of metals from algae under low pH conditions. In particular, both induction of metallothionein synthesis by Zn and competition between Zn and Cd ions for uptake at target sites on the gut wall may be involved in determining sublethal responses to mixtures of both metals.

Semi-dwarfism and lodging tolerance in tef (Eragrostis tef) is linked to a mutation in the α-Tubulin 1 gene

PubMed Central

Jöst, Moritz; Esfeld, Korinna; Burian, Agata; Cannarozzi, Gina; Chanyalew, Solomon; Kuhlemeier, Cris; Assefa, Kebebew; Tadele, Zerihun

2015-01-01

Genetic improvement of native crops is a new and promising strategy to combat hunger in the developing world. Tef is the major staple food crop for approximately 50 million people in Ethiopia. As an indigenous cereal, it is well adapted to diverse climatic and soil conditions; however, its productivity is extremely low mainly due to susceptibility to lodging. Tef has a tall and weak stem, liable to lodge (or fall over), which is aggravated by wind, rain, or application of nitrogen fertilizer. To circumvent this problem, the first semi-dwarf lodging-tolerant tef line, called kegne, was developed from an ethyl methanesulphonate (EMS)-mutagenized population. The response of kegne to microtubule-depolymerizing and -stabilizing drugs, as well as subsequent gene sequencing and segregation analysis, suggests that a defect in the α-Tubulin gene is functionally and genetically tightly linked to the kegne phenotype. In diploid species such as rice, homozygous mutations in α-Tubulin genes result in extreme dwarfism and weak stems. In the allotetraploid tef, only one homeologue is mutated, and the presence of the second intact α-Tubulin gene copy confers the agriculturally beneficial semi-dwarf and lodging-tolerant phenotype. Introgression of kegne into locally adapted and popular tef cultivars in Ethiopia will increase the lodging tolerance in the tef germplasm and, as a result, will improve the productivity of this valuable crop. PMID:25399019

Transcription factor-mediated reprogramming toward hematopoietic stem cells

PubMed Central

Ebina, Wataru; Rossi, Derrick J

2015-01-01

De novo generation of human hematopoietic stem cells (HSCs) from renewable cell types has been a long sought-after but elusive goal in regenerative medicine. Paralleling efforts to guide pluripotent stem cell differentiation by manipulating developmental cues, substantial progress has been made recently toward HSC generation via combinatorial transcription factor (TF)-mediated fate conversion, a paradigm established by Yamanaka's induction of pluripotency in somatic cells by mere four TFs. This review will integrate the recently reported strategies to directly convert a variety of starting cell types toward HSCs in the context of hematopoietic transcriptional regulation and discuss how these findings could be further developed toward the ultimate generation of therapeutic human HSCs. PMID:25712209

Isolation, characterization, and differentiation of stem cells for cartilage regeneration.

PubMed

Beane, Olivia S; Darling, Eric M

2012-10-01

The goal of tissue engineering is to create a functional replacement for tissues damaged by injury or disease. In many cases, impaired tissues cannot provide viable cells, leading to the investigation of stem cells as a possible alternative. Cartilage, in particular, may benefit from the use of stem cells since the tissue has low cellularity and cannot effectively repair itself. To address this need, researchers are investigating the chondrogenic capabilities of several multipotent stem cell sources, including adult and extra-embryonic mesenchymal stem cells (MSCs), embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs). Comparative studies indicate that each cell type has advantages and disadvantages, and while direct comparisons are difficult to make, published data suggest some sources may be more promising for cartilage regeneration than others. In this review, we identify current approaches for isolating and chondrogenically differentiating MSCs from bone marrow, fat, synovium, muscle, and peripheral blood, as well as cells from extra-embryonic tissues, ESCs, and iPSCs. Additionally, we assess chondrogenic induction with growth factors, identifying standard cocktails used for each stem cell type. Cell-only (pellet) and scaffold-based studies are also included, as is a discussion of in vivo results.

Contribution of Hepatic Retinaldehyde Dehydrogenase Induction to Impairment of Glucose Metabolism by High-Fat Diet Feeding in C57BL/6J Mice.

PubMed

Xu, Jiong; Zhang, Mian; Zhang, Xiangping; Yang, Hanyu; Sun, Binbin; Wang, Zhongjian; Zhou, Yaqian; Wang, Shuting; Liu, Xiaodong; Liu, Li

2018-05-12

Obesity and insulin resistance are associated with overexpression of retinaldehyde dehydrogenase 1 (RALDH1). We aimed to investigate the roles of hepatic RALDH1 induction in glucose metabolism impairment using mice fed with high-fat diet (HFD). Mice were fed with HFD for 8 weeks and treated with RALDH inhibitor citral for another 4 weeks. Oral glucose tolerance test (OGTT), pyruvate tolerance test (PTT) and insulin tolerance test (ITT) were operated. Expressions of Phosphoenolpyruvate carboxykinase 1 (PCK1), glucokinase (GCK) and RALDH1 were measured. Therapeutic effects of citral were also conducted in diabetic rats. Effects of retinaldehyde on PCK1 and GCK expressions were examined in rat primary hepatocytes and HepG2 cells. The results showed that HFD mice were characterized by hyperlipidaemia and insulin resistance, accompanied by significantly increased RALDH1 activity and expression. Citral (10 and 50 mg/kg) ameliorated HFD-induced hyperlipidaemia and insulin resistance, as evidenced by the improved fasting glucose, insulin levels and lipid profiles. OGTT and PTT demonstrated that citral reversed HFD-induced glucose disposal impairment and glucose production enhancement. Citral also reversed the increased PCK1 expression and decreased GCK expression by HFD. Citral therapeutic effects were reconfirmed in diabetic rats. In vitro data indicated that retinaldehyde had the strongest PCK1 induction in primary hepatocytes of diabetic rats compared with HFD rats and control rats, in line with the increased RALDH1 expression. Citral reversed the retinaldehyde-induced PCK1 expression in primary rat hepatocytes and HepG2 cells. In conclusion, RALDH1 induction impaired glucose metabolism partly via modulating PCK1 and GCK expression. Citral improved glucose metabolism through inhibiting RALDH activity. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Hyperglycemic Stress Impairs the Stemness Capacity of Kidney Stem Cells in Rats.

PubMed

Yang, Guang; Jia, Yali; Li, Chunlin; Cheng, Qingli; Yue, Wen; Pei, Xuetao

2015-01-01

The incidence of acute kidney injury in patients with diabetes is significantly higher than that of patients without diabetes, and may be associated with the poor stemness capacity of kidney stem cells (KSCs) and limited recovery of injured renal tubules. To investigate the effects of hyperglycemic stress on KSC stemness, KSCs were isolated from the rat renal papilla and analyzed for their self-renewal and differentiation abilities. Our results showed that isolated KSCs expressed the mesenchymal stem cell markers N-cadherin, Nestin, CD133, CD29, CD90, and CD73. Moreover, KSCs co-cultured with hypoxia-injured renal tubular epithelial cell (RTECs) induced the expression of the mature epithelial cell marker CK18, suggesting that the KSCs could differentiate into RTECs in vitro. However, KSC proliferation, differentiation ability and tolerance to hypoxia were decreased in high-glucose cultures. Taken together, these results suggest the high-glucose microenvironment can damage the reparative ability of KSCs. It may result in a decreased of recovery capability of renal tubules from injury.

Immunotherapy of allergic contact dermatitis.

PubMed

Spiewak, Radoslaw

2011-08-01

The term 'immunotherapy' refers to treating diseases by inducing, enhancing or suppressing immune responses. As allergy is an excessive, detrimental immune reaction to otherwise harmless environmental substances, immunotherapy of allergic disease is aimed at the induction of tolerance toward sensitizing antigens. This article focuses on the historical developments, present state and future outlook for immunotherapy with haptens as a therapeutic modality for allergic contact dermatitis. Inspired by the effectiveness of immunotherapy in respiratory allergies, attempts were undertaken at curing allergic contact dermatitis by means of controlled administration of the sensitizing haptens. Animal and human experiments confirmed that tolerance to haptens can be induced most effectively when the induction of tolerance precedes attempted sensitization. In real life, however, therapy is sought by people who are already sensitized and an effective reversal of hypersensitivity seems more difficult to achieve. Decades of research on Rhus hypersensitivity led to a conclusion that immunotherapy can suppress Rhus dermatitis, however, only to a limited degree, for a short period of time, and at a high risk of side effects, which makes this method therapeutically unprofitable. Methodological problems with most available studies of immunotherapy of contact allergy to nickel make any definite conclusions impossible at this stage.

Induction of cross-tolerance between protective effect of morphine and nicotine in 6-hydroxydopamine-induce neurotoxicity in SH-SY5Y human dopaminergic neuroblastoma cells.

PubMed

Elyasi, Leila; Eftekhar-Vaghefi, Seyed Hassan; Asadi-Shekaaria, Majid; Esmaeili-Mahani, Saeed

2018-06-27

Parkinson's disease is a progressive neurodegenerative disease characterized by progressive and selective death of dopaminergic neurons. It has been reported that nicotine and morphine have protective roles during neuronal damage in Parkinson's disease. In addition, the induction of cross-tolerance between their biological effects has been shown in numerous reports. Here, we investigated the effects of nicotine and morphine on 6-OHDA-induced neurotoxicity in human neuroblastoma SH-SY5Y cell line as an in vitro model of Parkinson's disease. Cell damage was induced by 150 μM 6-OHDA and the cells viability was examined by MTT assay. Intracellular reactive oxygen species, calcium level and mitochondrial membrane potential were determined by fluorescence spectrophotometer method. Biochemical markers of apoptosis were also evaluated by immunoblotting. The data showed that morphine and nicotine prevent 6-OHDA- induced cell damage and apoptosis. However, the protective effects of nicotine were not observed in chronic morphine-pretreated cells. Morphine had no protective effects in chronic nicotine-incubated cells. A cross-tolerance between protective effects of morphine and nicotine was occurred in 6-OHDA-induced SH-SY5Y cell toxicity.

Spaceflight impairs antigen-specific tolerance induction in vivo and increases inflammatory cytokines.

PubMed

Chang, Tammy T; Spurlock, Sandra M; Candelario, Tara Lynne T; Grenon, S Marlene; Hughes-Fulford, Millie

2015-10-01

The health risks of a dysregulated immune response during spaceflight are important to understand as plans emerge for humans to embark on long-term space travel to Mars. In this first-of-its-kind study, we used adoptive transfer of T-cell receptor transgenic OT-II CD4 T cells to track an in vivo antigen-specific immune response that was induced during the course of spaceflight. Experimental mice destined for spaceflight and mice that remained on the ground received transferred OT-II cells and cognate peptide stimulation with ovalbumin (OVA) 323-339 plus the inflammatory adjuvant, monophosphoryl lipid A. Control mice in both flight and ground cohorts received monophosphoryl lipid A alone without additional OVA stimulation. Numbers of OT-II cells in flight mice treated with OVA were significantly increased by 2-fold compared with ground mice treated with OVA, suggesting that tolerance induction was impaired by spaceflight. Production of proinflammatory cytokines were significantly increased in flight compared with ground mice, including a 5-fold increase in IFN-γ and a 10-fold increase in IL-17. This study is the first to show that immune tolerance may be impaired in spaceflight, leading to excessive inflammatory responses. © FASEB.

Brief exposures of human body lice to sub-lethal amounts of ivermectin over transcribes detoxification genes involved in tolerance

PubMed Central

Yoon, K. S.; Strycharz, J. P.; Baek, J. H.; Sun, W.; Kim, J.H.; Kang, J.S.; Pittendrigh, B. R.; Lee, S. H.; Clark, J. M.

2011-01-01

Transcriptional profiling results, using our non-invasive induction assay [short exposure intervals (2–5 h) to sub-lethal amounts of insecticides (

Tolerating dissimilar other when primed with death: neural evidence of self-control engaged by interdependent people in Japan.

PubMed

Yanagisawa, Kuniaki; Kashima, Emiko S; Moriya, Hiroki; Masui, Keita; Furutani, Kaichiro; Yoshida, Hiroshi; Ura, Mitsuhiro; Nomura, Michio

2017-06-01

Mortality salience (MS) has been shown to lead to derogation of others with dissimilar worldviews, yet recent research has shown that Asian-Americans who presumably adopt an interdependent self-construal (SC) tend to reveal greater tolerance after MS induction. In the present study, we demonstrated that Japanese individuals who are high on interdependent SC indeed show greater tolerance toward worldview-threatening other in the MS (vs control) condition, thus replicating the prior research. Extending this research, we also found that interdependent people's tolerance toward worldview-threatening other was mediated by increased activity in the right ventrolateral prefrontal cortex in the MS condition. These data suggested that when exposed to death-related stimuli, highly interdependent individuals may spontaneously activate their neural self-control system which may serve to increase tolerance toward others. © The Author (2017). Published by Oxford University Press.

Tandem High-Dose Chemotherapy and Autologous Stem Cell Transplantation for Atypical Teratoid/Rhabdoid Tumor

PubMed Central

Sung, Ki Woong; Lim, Do Hoon; Yi, Eun Sang; Choi, Young Bae; Lee, Ji Won; Yoo, Keon Hee; Koo, Hong Hoe; Kim, Ji Hye; Suh, Yeon-Lim; Joung, Yoo Sook; Shin, Hyung Jin

2016-01-01

Purpose We prospectively evaluated the effectiveness of tandem high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT) in improving the survival of patients with atypical teratoid/rhabdoid tumors while reducing the risks of late adverse effects from radiotherapy (RT). Materials and Methods For young children (< 3 years old), tandem HDCT/auto-SCT was administered after six cycles of induction chemotherapy. RT was deferred until after 3 years of age unless the tumor showed relapse or progression. For older patients (> 3 years old), RT including reduced-dose craniospinal RT (23.4 or 30.6 Gy) was administered either after two cycles of induction chemotherapy or after surgery, and tandem HDCT/auto-SCT was administered after six cycles of induction chemotherapy. Results A total of 13 patients (five young and eight older) were enrolled from November 2004 to June 2012. Eight patients, including all five young patients, had metastatic disease at diagnosis. Six patients (four young and two older) experienced progression before initiation of RT, and seven were able to proceed to HDCT/auto-SCT without progression during induction treatment. Three of six patients who experienced progression during induction treatment underwent HDCT/auto-SCT as salvage treatment. All five young patients died from disease progression. However, four of the eight older patients remain progression-freewith a median follow-up period of 64 months (range, 39 to 108 months). Treatment-related late toxicities were acceptable. Conclusion The required dose of craniospinal RT might be reduced in older patients if the intensity of chemotherapy is increased. However, early administration of RT should be considered to prevent early progression in young patients. PMID:27034140

Hematopoietic stem cell injury induced by ionizing radiation.

PubMed

Shao, Lijian; Luo, Yi; Zhou, Daohong

2014-03-20

Exposure to ionizing radiation (IR) as the result of nuclear accidents or terrorist attacks is a significant threat and a major medical concern. Hematopoietic stem cell (HSC) injury is the primary cause of death after accidental or intentional exposure to a moderate or high dose of IR. Protecting HSCs from IR should be a primary goal in the development of novel medical countermeasures against radiation. Significant progress has been made in our understanding of the mechanisms by which IR causes HSC damage. The mechanisms include (i) induction of HSC apoptosis via the p53-Puma pathway; (ii) promotion of HSC differentiation via the activation of the G-CSF/Stat3/BATF-dependent differentiation checkpoint; (iii) induction of HSC senescence via the ROS-p38 pathway; and (iv) damage to the HSC niche. Induction of apoptosis in HSCs and hematopoietic progenitor cells is primarily responsible for IR-induced acute bone marrow (BM) injury. Long-term BM suppression caused by IR is mainly attributable to the induction of HSC senescence. However, the promotion of HSC differentiation and damage to the HSC niche can contribute to both the acute and long-term effects of IR on the hematopoietic system. In this review, we have summarized a number of recent findings that provide new insights into the mechanisms whereby IR damages HSCs. These findings will provide new opportunities for developing a mechanism-based strategy to prevent and/or mitigate IR-induced BM suppression. Antioxid.

Impact of induction treatment before autologous stem cell transplantation on long-term outcome in patients with newly diagnosed multiple myeloma.

PubMed

Gassiot, Susanna; Motlló, Cristina; Llombart, Inuska; Morgades, Mireia; González, Yolanda; Garcia-Caro, Montse; Ribera, Josep-Maria; Oriol, Albert

2017-06-01

Clinical trials for patients with multiple myeloma (MM) using novel agent (NA)-based regimens before autologous stem cell transplantation (SCT) have shown improvement in response rates and progression-free survival (PFS); however they have failed to identify a significant overall survival (OS) benefit. The aim of this study was to analyze the potential impact of initial induction on the feasibility and outcome of subsequent treatment lines in a real clinical practice setting. Patients with consecutive MM <70 years of age diagnosed between 1999 and 2009 were prospectively registered and classified as having received conventional chemotherapy induction regimens with new agents available at relapse (CC cohort, 89 patients) or as treated with NAs upfront (NA cohort, 65 patients). Patients in the NA cohort demonstrated a superior median PFS (2.8 years vs 1.6 years, P=.03) and also a median PFS from diagnosis to second progression (5.2 years vs 2.7 years, P=.003). After a median follow-up of 7 years, clear differences in OS were observed (7.97 years in NA cohort compared to 3.35 years in CC cohort, P<.001). New agent-based first-line induction treatments provide benefits in both PFS and beyond that point, contributing to a significant improvement in OS. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

40 CFR 180.603 - Dinotefuran; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the table below: Commodity Parts per million Brassica, head and stem, subgroup 5A 1.4 Brassica, leafy... Vegetable, fruiting, group 8 0.7 Vegetable, cucurbit, group 9 0.5 Vegetable, leafy, except Brassica, group 4...

Design-based online teacher professional development to introduce integration of STEM in Pakistan

NASA Astrophysics Data System (ADS)

Anwar, Tasneem

In today's global society where innovations spread rapidly, the escalating focus on science, technology, engineering and mathematics (STEM) has quickly intensified in the United States, East Asia and much of Western Europe. Our ever-changing, increasingly global society faces many multidisciplinary problems, and many of the solutions require the integration of multiple science, technology, engineering, and mathematics (STEM) concepts. Thus, there is a critical need to explore the integration of STEM subjects in international education contexts. This dissertation study examined the exploration of integration of STEM in the unique context of Pakistan. This study used three-phase design-based methodological framework derived from McKenney and Reeves (2012) to explore the development of a STEM focused online teacher professional development (oTPD-STEM) and to identify the design features that facilitate teacher learning. The oTPD-STEM program was designed to facilitate eight Pakistani elementary school teachers' exploration of the new idea of STEM integration through both practical and theoretical considerations. This design-based study employed inductive analysis (Strauss and Corbin, 1998) to analyze multiple data sources of interviews, STEM perception responses, reflective learning team conversations, pre-post surveys and artifacts produced in oTPD-STEM. Findings of this study are presented as: (1) design-based decisions for oTPD-STEM, and (2) evolution in understanding of STEM by sharing participant teachers' STEM model for Pakistani context. This study advocates for the potential of school-wide oTPD for interdisciplinary collaboration through support for learner-centered practices.

Pyramiding transgenes for multiple resistance in rice against bacterial blight, yellow stem borer and sheath blight.

PubMed

Datta, K; Baisakh, N; Thet, K Maung; Tu, J; Datta, S K

2002-12-01

Here we describe the development of transgene-pyramided stable elite rice lines resistant to disease and insect pests by conventional crossing of two transgenic parental lines transformed independently with different genes. The Xa21 gene (resistance to bacterial blight), the Bt fusion gene (for insect resistance) and the chitinase gene (for tolerance of sheath blight) were combined in a single rice line by reciprocal crossing of two transgenic homozygous IR72 lines. F4 plant lines carrying all the genes of interest stably were identified using molecular methods. The identified lines, when exposed to infection caused by Xanthomonas oryzae pv oryzae, showed resistance to bacterial blight. Neonate larval mortality rates of yellow stem borer ( Scirpophaga incertulas) in an insect bioassay of the same identified lines were 100%. The identified line pyramided with different genes to protect against yield loss showed high tolerance of sheath blight disease caused by Rhizoctonia solani.

Clinical implications of basic science discoveries: induced pluripotent stem cell therapy in transplantation--a potential role for immunologic tolerance.

PubMed

Wertheim, J A; Leventhal, J R

2015-04-01

Induced pluripotent stem cells (iPSCs) hold the potential for future development of genetically identical tissues from almost any mature cell lineage. For clinical applications in cell therapy and transplantation, it may provide a means to one-day restore dysfunctional or damaged tissue without the need for immunosuppression. A recent study by de Almeida et al published in the journal Nature Communications indicates that iPSCs may indeed elicit an immune response that evolves as cells differentiate toward maturity to induce a state of tolerance within a recipient animal. If these early findings hold true, it suggests a possible explanation for self-recognition of mature cells derived from iPSCs for use in future therapeutic interventions in transplantation such as cellular therapy or tissue engineering. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.

Cell-Penetrating Peptide as a Means of Directing the Differentiation of Induced-Pluripotent Stem Cells.

PubMed

Kaitsuka, Taku; Tomizawa, Kazuhito

2015-11-06

Protein transduction using cell-penetrating peptides (CPPs) is useful for the delivery of large protein molecules, including some transcription factors. This method is safer than gene transfection methods with a viral vector because there is no risk of genomic integration of the exogenous DNA. Recently, this method was reported as a means for the induction of induced pluripotent stem (iPS) cells, directing the differentiation into specific cell types and supporting gene editing/correction. Furthermore, we developed a direct differentiation method to obtain a pancreatic lineage from mouse and human pluripotent stem cells via the protein transduction of three transcription factors, Pdx1, NeuroD, and MafA. Here, we discuss the possibility of using CPPs as a means of directing the differentiation of iPS cells and other stem cell technologies.

Neoplastic Bone Marrow Niche: Hematopoietic and Mesenchymal Stem Cells

PubMed Central

Saki, Najmaldin; Abroun, Saeid; Farshdousti Hagh, Majid; Asgharei, Farahnaz

2011-01-01

The neoplastic niche comprises complex interactions between multiple cell types and molecules requiring cell-cell signaling as well as local secretion. These niches are important for both the maintenance of cancer stem cells and the induction of neoplastic cells survival and proliferation. Each niche contains a population of tumor stem cells supported by a closely associated vascular bed comprising mesenchyme-derived cells and extracellular matrix. Targeting cancer stem cells and neoplastic niche may provide new therapies to eradicate tumors. Much progress has been very recently made in the understanding of the cellular and molecular interactions in the microenvironment of neoplastic niches. This review article provides an overview of the neoplastic niches in the bone marrow. In addition to highlighting recent advances in the field, we will also discuss components of the niche and their signaling pathways. PMID:23508881

Induction of vascular endothelial phenotype and cellular proliferation from human cord blood stem cells cultured in simulated microgravity

NASA Astrophysics Data System (ADS)

Chiu, Brian; Z-M Wan, Jim; Abley, Doris; Akabutu, John

2005-05-01

Recent studies have demonstrated that stem cells derived from adult hematopoietic tissues are capable of trans-differentiation into non-hematopoietic cells, and that the culture in microgravity ( μg) may modulate the proliferation and differentiation. We investigated the application of μg to human umbilical cord blood stem cells (CBSC) in the induction of vascular endothelial phenotype expression and cellular proliferation. CD34+ mononuclear cells were isolated from waste human umbilical cord blood samples and cultured in simulated μg for 14 days. The cells were seeded in rotary wall vessels (RWV) with or without microcarrier beads (MCB) and vascular endothelial growth factor was added during culture. Controls consisted of culture in 1 G. The cell cultures in RWV were examined by inverted microscopy. Cell counts, endothelial cell and leukocyte markers performed by flow-cytometry and FACS scan were assayed at days 1, 4, 7 and at the termination of the experiments. Culture in RWV revealed significantly increased cellular proliferation with three-dimensional (3D) tissue-like aggregates. At day 4, CD34+ cells cultured in RWV bioreactor without MCB developed vascular tubular assemblies and exhibited endothelial phenotypic markers. These data suggest that CD34+ human umbilical cord blood progenitors are capable of trans-differentiation into vascular endothelial cell phenotype and assemble into 3D tissue structures. Culture of CBSC in simulated μg may be potentially beneficial in the fields of stem cell biology and somatic cell therapy.

Hypoxia-Mediated Epigenetic Regulation of Stemness in Brain Tumor Cells.

PubMed

Prasad, Pankaj; Mittal, Shivani Arora; Chongtham, Jonita; Mohanty, Sujata; Srivastava, Tapasya

2017-06-01

Activation of pluripotency regulatory circuit is an important event in solid tumor progression and the hypoxic microenvironment is known to enhance the stemness feature of some cells. The distinct population of cancer stem cells (CSCs)/tumor initiating cells exist in a niche and augment invasion, metastasis, and drug resistance. Previously, studies have reported global hypomethylation and site-specific aberrant methylation in gliomas along with other epigenetic modifications as important contributors to genomic instability during glioma progression. Here, we have demonstrated the role of hypoxia-mediated epigenetic modifications in regulating expression of core pluripotency factors, OCT4 and NANOG, in glioma cells. We observe hypoxia-mediated induction of demethylases, ten-eleven-translocation (TET) 1 and 3, but not TET2 in our cell-line model. Immunoprecipitation studies reveal active demethylation and direct binding of TET1 and 3 at the Oct4 and Nanog regulatory regions. Tet1 and 3 silencing assays further confirmed induction of the pluripotency pathway involving Oct4, Nanog, and Stat3, by these paralogues, although with varying degrees. Knockdown of Tet1 and Tet3 inhibited the formation of neurospheres in hypoxic conditions. We observed independent roles of TET1 and TET3 in differentially regulating pluripotency and differentiation associated genes in hypoxia. Overall, this study demonstrates an active demethylation in hypoxia by TET1 and 3 as a mechanism of Oct4 and Nanog overexpression thus contributing to the formation of CSCs in gliomas. Stem Cells 2017;35:1468-1478. © 2017 AlphaMed Press.

Isolation of canine mesenchymal stem cells from amniotic fluid and differentiation into hepatocyte-like cells.

PubMed

Choi, Seon-A; Choi, Hoon-Sung; Kim, Keun Jung; Lee, Dong-Soo; Lee, Ji Hey; Park, Jie Yeun; Kim, Eun Young; Li, Xiaoxia; Oh, Hyun-Yang; Lee, Dong-Seok; Kim, Min Kyu

2013-01-01

Recent findings have demonstrated that amniotic fluid cells are an interesting and potential source of mesenchymal stem cells (MSCs). In this study, we isolated MSCs from canine amniotic fluid and then characterized their multilineage differentiation ability. Canine amniotic fluid stem (cAFS) cells at passage 5 had a fibroblast-like morphology instead of forming colonies and were positive for pluripotent stem cell markers such as OCT4, NANOG, and SOX2. Flow cytometry analysis showed the expression of MSC surface markers CD44, CD29, and CD90 on the cAFS cells. In addition, these cells were cultured under conditions favorable for adipogenic, chondrogenic, and osteogenic induction. The results of this experiment confirmed the mesenchymal nature of cAFS cells and their multipotent potential. Interestingly, although the cells exhibited a fibroblast-like morphology after hepatogenic induction, reverse transcription-polymerase chain reaction revealed that the expression of several hepatic genes, such as albumin, tyrosine aminotransferase, and alpha-1 antiproteinase, increased following maturation and differentiation. These findings indicated that cAFS cells have functional properties similar to those of hepatocytes. Taken together, the results of our study demonstrated that cAFS cells with mesenchymal characteristics can be successfully isolated from canine amniotic fluid and possess functional properties characteristic of hepatocytes. The findings of our work suggest that cAFS cells have the potential to be a resource for cell-based therapies in a canine model of hepatic disease.

Immunosuppressive Mesenchymal Stromal Cells Derived from Human-Induced Pluripotent Stem Cells Induce Human Regulatory T Cells In Vitro and In Vivo

PubMed Central

Roux, Clémence; Saviane, Gaëlle; Pini, Jonathan; Belaïd, Nourhène; Dhib, Gihen; Voha, Christine; Ibáñez, Lidia; Boutin, Antoine; Mazure, Nathalie M.; Wakkach, Abdelilah; Blin-Wakkach, Claudine; Rouleau, Matthieu

2018-01-01

Despite mesenchymal stromal cells (MSCs) are considered as a promising source of cells to modulate immune functions on cells from innate and adaptive immune systems, their clinical use remains restricted (few number, limited in vitro expansion, absence of a full phenotypic characterization, few insights on their in vivo fate). Standardized MSCs derived in vitro from human-induced pluripotent stem (huIPS) cells, remediating part of these issues, are considered as well as a valuable tool for therapeutic approaches, but their functions remained to be fully characterized. We generated multipotent MSCs derived from huiPS cells (huiPS-MSCs), and focusing on their immunosuppressive activity, we showed that human T-cell activation in coculture with huiPS-MSCs was significantly reduced. We also observed the generation of functional CD4+ FoxP3+ regulatory T (Treg) cells. Further tested in vivo in a model of human T-cell expansion in immune-deficient NSG mice, huiPS-MSCs immunosuppressive activity prevented the circulation and the accumulation of activated human T cells. Intracytoplasmic labeling of cytokines produced by the recovered T cells showed reduced percentages of human-differentiated T cells producing Th1 inflammatory cytokines. By contrast, T cells producing IL-10 and FoxP3+-Treg cells, absent in non-treated animals, were detected in huiPS-MSCs treated mice. For the first time, these results highlight the immunosuppressive activity of the huiPS-MSCs on human T-cell stimulation with a concomitant generation of human Treg cells in vivo. They may favor the development of new tools and strategies based on the use of huiPS cells and their derivatives for the induction of immune tolerance. PMID:29422893

Immunosuppressive Mesenchymal Stromal Cells Derived from Human-Induced Pluripotent Stem Cells Induce Human Regulatory T Cells In Vitro and In Vivo.

PubMed

Roux, Clémence; Saviane, Gaëlle; Pini, Jonathan; Belaïd, Nourhène; Dhib, Gihen; Voha, Christine; Ibáñez, Lidia; Boutin, Antoine; Mazure, Nathalie M; Wakkach, Abdelilah; Blin-Wakkach, Claudine; Rouleau, Matthieu

2017-01-01

Despite mesenchymal stromal cells (MSCs) are considered as a promising source of cells to modulate immune functions on cells from innate and adaptive immune systems, their clinical use remains restricted (few number, limited in vitro expansion, absence of a full phenotypic characterization, few insights on their in vivo fate). Standardized MSCs derived in vitro from human-induced pluripotent stem (huIPS) cells, remediating part of these issues, are considered as well as a valuable tool for therapeutic approaches, but their functions remained to be fully characterized. We generated multipotent MSCs derived from huiPS cells (huiPS-MSCs), and focusing on their immunosuppressive activity, we showed that human T-cell activation in coculture with huiPS-MSCs was significantly reduced. We also observed the generation of functional CD4 + FoxP3 + regulatory T (Treg) cells. Further tested in vivo in a model of human T-cell expansion in immune-deficient NSG mice, huiPS-MSCs immunosuppressive activity prevented the circulation and the accumulation of activated human T cells. Intracytoplasmic labeling of cytokines produced by the recovered T cells showed reduced percentages of human-differentiated T cells producing Th1 inflammatory cytokines. By contrast, T cells producing IL-10 and FoxP3 + -Treg cells, absent in non-treated animals, were detected in huiPS-MSCs treated mice. For the first time, these results highlight the immunosuppressive activity of the huiPS-MSCs on human T-cell stimulation with a concomitant generation of human Treg cells in vivo . They may favor the development of new tools and strategies based on the use of huiPS cells and their derivatives for the induction of immune tolerance.

Consolidation therapy with low-dose thalidomide and prednisolone prolongs the survival of multiple myeloma patients undergoing a single autologous stem-cell transplantation procedure.

PubMed

Spencer, Andrew; Prince, H Miles; Roberts, Andrew W; Prosser, Ian W; Bradstock, Kenneth F; Coyle, Luke; Gill, Devinder S; Horvath, Noemi; Reynolds, John; Kennedy, Nola

2009-04-10

Thalidomide is effective in the treatment of newly diagnosed and relapsed/refractory multiple myeloma (MM). However, the role of thalidomide in the post-autologous stem cell transplantation (ASCT) context remains unclear. This study assessed whether the addition of thalidomide consolidation following ASCT would improve the durability of responses achieved and overall survival. Between January 2002 and March 2005, 269 patients with newly diagnosed MM who achieved disease stabilization or better with conventional induction chemotherapy received a single high-dose melphalan conditioned ASCT. Post-ASCT, 129 patients were randomly assigned to receive indefinite prednisolone maintenance therapy (control group) and 114 to receive the same in addition to 12 months of thalidomide consolidation (thalidomide group). The primary study end points were progression-free survival (PFS) and overall survival (OS). The secondary end point was tolerability. After a median follow-up of 3 years, the postrandomization 3-year PFS rates were 42% and 23% (P < .001; hazard ratio [HR], 0.5; 95% CI, 0.35 to 0.71) and the OS rates were 86% and 75% (P = .004; HR, 0.41; 95% CI, 0.22 to 0.76) in the thalidomide and control groups, respectively. There was no difference in survival between groups 12 months after disease progression (79% v 77%; P = .237). Neurological toxicities were more common in the thalidomide arm but there were no differences between arms for thromboembolic events. Consolidation therapy with 12 months of thalidomide combined with prednisolone prolongs survival when used after a single high-dose therapy supported ASCT in patients with newly diagnosed MM. Furthermore, thalidomide consolidation therapy did not adversely impact on survival in the subsequent salvage setting.

Rigid microenvironments promote cardiac differentiation of mouse and human embryonic stem cells

NASA Astrophysics Data System (ADS)

Arshi, Armin; Nakashima, Yasuhiro; Nakano, Haruko; Eaimkhong, Sarayoot; Evseenko, Denis; Reed, Jason; Stieg, Adam Z.; Gimzewski, James K.; Nakano, Atsushi

2013-04-01

While adult heart muscle is the least regenerative of tissues, embryonic cardiomyocytes are proliferative, with embryonic stem (ES) cells providing an endless reservoir. In addition to secreted factors and cell-cell interactions, the extracellular microenvironment has been shown to play an important role in stem cell lineage specification, and understanding how scaffold elasticity influences cardiac differentiation is crucial to cardiac tissue engineering. Though previous studies have analyzed the role of matrix elasticity on the function of differentiated cardiomyocytes, whether it affects the induction of cardiomyocytes from pluripotent stem cells is poorly understood. Here, we examine the role of matrix rigidity on cardiac differentiation using mouse and human ES cells. Culture on polydimethylsiloxane (PDMS) substrates of varied monomer-to-crosslinker ratios revealed that rigid extracellular matrices promote a higher yield of de novo cardiomyocytes from undifferentiated ES cells. Using a genetically modified ES system that allows us to purify differentiated cardiomyocytes by drug selection, we demonstrate that rigid environments induce higher cardiac troponin T expression, beating rate of foci, and expression ratio of adult α- to fetal β- myosin heavy chain in a purified cardiac population. M-mode and mechanical interferometry image analyses demonstrate that these ES-derived cardiomyocytes display functional maturity and synchronization of beating when co-cultured with neonatal cardiomyocytes harvested from a developing embryo. Together, these data identify matrix stiffness as an independent factor that instructs not only the maturation of already differentiated cardiomyocytes but also the induction and proliferation of cardiomyocytes from undifferentiated progenitors. Manipulation of the stiffness will help direct the production of functional cardiomyocytes en masse from stem cells for regenerative medicine purposes.

The CD8 T-cell response during tolerance induction in liver transplantation

PubMed Central

Wong, Yik Chun; McCaughan, Geoffrey W; Bowen, David G; Bertolino, Patrick

2016-01-01

Both experimental and clinical studies have shown that the liver possesses unique tolerogenic properties. Liver allografts can be spontaneously accepted across complete major histocompatibility mismatch in some animal models. In addition, some liver transplant patients can be successfully withdrawn from immunosuppressive medications, developing ‘operational tolerance'. Multiple mechanisms have been shown to be involved in inducing and maintaining alloimmune tolerance associated with liver transplantation. Here, we focus on CD8 T-cell tolerance in this setting. We first discuss how alloreactive cytotoxic T-cell responses are generated against allografts, before reviewing how the liver parenchyma, donor passenger leucocytes and the host immune system function together to attenuate alloreactive CD8 T-cell responses to promote the long-term survival of liver transplants. PMID:27867515

Stepwise renal lineage differentiation of mouse embryonic stem cells tracing in vivo development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishikawa, Masaki, E-mail: masakiwestriver@gmail.com; University of California at Los Angeles, David Geffen School of Medicine, Los Angeles, CA 91343; Yanagawa, Naomi

2012-01-13

Highlights: Black-Right-Pointing-Pointer We induced renal lineages from mESCs by following the in vivo developmental cues. Black-Right-Pointing-Pointer We induced nephrogenic intermediate mesoderm by stepwise addition of factors. Black-Right-Pointing-Pointer We induced two types of renal progenitor cells by reciprocal conditioned media. Black-Right-Pointing-Pointer We propose the potential role of CD24 for the enrichment of renal lineage cells. -- Abstract: The in vitro derivation of renal lineage progenitor cells is essential for renal cell therapy and regeneration. Despite extensive studies in the past, a protocol for renal lineage induction from embryonic stem cells remains unestablished. In this study, we aimed to induce renal lineagesmore » from mouse embryonic stem cells (mESC) by following in vivo developmental stages, i.e., the induction of mesoderm (Stage I), intermediate mesoderm (Stage II) and renal lineages (Stage III). For stage I induction, in accordance with known signaling pathways involved in mesoderm development in vivo, i.e., Nodal, bone morphogenic proteins (BMPs) and Wnt, we found that the sequential addition of three factors, i.e., Activin-A (A), a surrogate for Nodal signaling, during days 0-2, A plus BMP-4 (4) during days 2-4, and A4 plus lithium (L), a surrogate for Wnt signaling, during days 4-6, was most effective to induce the mesodermal marker, Brachyury. For stage II induction, the addition of retinoic acid (R) in the continuous presence of A4L during days 6-8 was most effective to induce nephrogenic intermediate mesodermal markers, such as Pax2 and Lim1. Under this condition, more than 30% of cells were stained positive for Pax2, and there was a concomitant decrease in the expression of non-mesodermal markers. For stage III induction, in resemblance to the reciprocal induction between ureteric bud (UB) and metanephric mesenchyme (MM) during kidney development, we found that the exposure to conditioned media derived from UB and MM cells was effective in inducing MM and UB markers, respectively. We also observed the emergence and gradual increase of cell populations expressing progenitor cell marker CD24 from Stage I to Stage III. These CD24{sup +} cells correlated with higher levels of expression of Brachyury at stage I, Pax2 and Lim1 at stage II and MM markers, such as WT1 and Cadherin 11, after exposure to UB-conditioned media at stage III. In conclusion, our results show that stepwise induction by tracing in vivo developmental stages was effective to generate renal lineage progenitor cells from mESC, and CD24 may serve as a useful surface marker for renal lineage cells at stage II and MM cells at stage III.« less

INDUCTION OF IMMUNOLOGIC TOLERANCE IN OLDER NEW ZEALAND MICE REPOPULATED WITH YOUNG SPLEEN, BONE MARROW, OR THYMUS

PubMed Central

Staples, Parker J.; Steinberg, Alfred D.; Talal, Norman

1970-01-01

Newborn, 7–9 day, and 16–18 day old NZB and B/W mice were, unlike older New Zealand mice, rendered tolerant to single doses of 8–10 mg of soluble BGG. After challenge, this tolerance was of short duration and escape occurred rapidly. Age-matched and similarly treated C3H, Balb/c and C57Bl mice did not escape from tolerance. Partial tolerance could be maintained by repeated injections of BGG. Biofiltration ruled out hyperphagocytosis as an explanation for this resistance to tolerance. Tolerance could be induced in older B/W mice if they were thymectomized, irradiated, and repopulated with young (12–15 day), but not old (2–3 month), spleen or bone marrow cells. Old bone marrow cells gave a non-tolerant response even when combined with young thymic grafts. Young bone marrow gave a tolerant response which was followed by the expected rapid escape only if a young thymus graft was also present. Escape was retarded if old thymus, or old irradiated thymus, was combined with young bone marrow. These results are best explained by abnormalities of both lymphoid precursors and thymic regulation. PMID:4192570

Cloning of a cystatin gene from sugar beet M14 that can enhance plant salt tolerance.

PubMed

Wang, Yuguang; Zhan, Yanan; Wu, Chuan; Gong, Shilong; Zhu, Ning; Chen, Sixue; Li, Haiying

2012-08-01

An open reading frame encoding a cysteine protease inhibitor, cystatin was isolated from the buds of sugar beet monosomic addition line M14 (BvM14) using 5'-/3'-RACE method. It encoded a polypeptide of 104 amino acids with conserved G and PW motifs, the consensus phytocystatin sequence LARFAV and the active site QVVAG. The protein showed significant homology to other plant cystatins. BvM14-cystatin was expressed ubiquitously in roots, stems, leaves and flower tissues with relatively high abundance in developing stems and roots. It was found to be localized in the nucleus, cytoplasm and plasma membrane. Recombinant BvM14-cystatin expressed in Escherichia coli was purified and it exhibited cysteine protease inhibitor activity. Salt-stress treatment induced BvM14-cystatin transcript levels in the M14 seedlings. Homozygous Arabidopsis plants over-expressing BvM14-cystatin showed enhanced salt tolerance. Taken together, these data improved understanding of the functions of BvM14-cystatin and highlighted the possibility of employing the cystatin in engineering plants for enhanced salt tolerance. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Non-Native Ambrosia Beetles as Opportunistic Exploiters of Living but Weakened Trees

PubMed Central

Ranger, Christopher M.; Schultz, Peter B.; Frank, Steven D.; Chong, Juang H.; Reding, Michael E.

2015-01-01

Exotic Xylosandrus spp. ambrosia beetles established in non-native habitats have been associated with sudden and extensive attacks on a diverse range of living trees, but factors driving their shift from dying/dead hosts to living and healthy ones are not well understood. We sought to characterize the role of host physiological condition on preference and colonization by two invaders, Xylosandrus germanus and Xylosandrus crassiusculus. When given free-choice under field conditions among flooded and non-flooded deciduous tree species of varying intolerance to flooding, beetles attacked flood-intolerant tree species over more tolerant species within 3 days of initiating flood stress. In particular, flood-intolerant flowering dogwood (Cornus florida) sustained more attacks than flood-tolerant species, including silver maple (Acer saccharinum) and swamp white oak (Quercus bicolor). Ethanol, a key host-derived attractant, was detected at higher concentrations 3 days after initiating flooding within stems of flood intolerant species compared to tolerant and non-flooded species. A positive correlation was also detected between ethanol concentrations in stem tissue and cumulative ambrosia beetle attacks. When adult X. germanus and X. crassiusculus were confined with no-choice to stems of flood-stressed and non-flooded C. florida, more ejected sawdust resulting from tunneling activity was associated with the flood-stressed trees. Furthermore, living foundresses, eggs, larvae, and pupae were only detected within galleries created in stems of flood-stressed trees. Despite a capability to attack diverse tree genera, X. germanus and X. crassiusculus efficiently distinguished among varying host qualities and preferentially targeted trees based on their intolerance of flood stress. Non-flooded trees were not preferred or successfully colonized. This study demonstrates the host-selection strategy exhibited by X. germanus and X. crassiusculus in non-native habitats involves detection of stress-induced ethanol emission and early colonization of living but weakened trees. PMID:26134522

Non-Native Ambrosia Beetles as Opportunistic Exploiters of Living but Weakened Trees.

PubMed

Ranger, Christopher M; Schultz, Peter B; Frank, Steven D; Chong, Juang H; Reding, Michael E

2015-01-01

Exotic Xylosandrus spp. ambrosia beetles established in non-native habitats have been associated with sudden and extensive attacks on a diverse range of living trees, but factors driving their shift from dying/dead hosts to living and healthy ones are not well understood. We sought to characterize the role of host physiological condition on preference and colonization by two invaders, Xylosandrus germanus and Xylosandrus crassiusculus. When given free-choice under field conditions among flooded and non-flooded deciduous tree species of varying intolerance to flooding, beetles attacked flood-intolerant tree species over more tolerant species within 3 days of initiating flood stress. In particular, flood-intolerant flowering dogwood (Cornus florida) sustained more attacks than flood-tolerant species, including silver maple (Acer saccharinum) and swamp white oak (Quercus bicolor). Ethanol, a key host-derived attractant, was detected at higher concentrations 3 days after initiating flooding within stems of flood intolerant species compared to tolerant and non-flooded species. A positive correlation was also detected between ethanol concentrations in stem tissue and cumulative ambrosia beetle attacks. When adult X. germanus and X. crassiusculus were confined with no-choice to stems of flood-stressed and non-flooded C. florida, more ejected sawdust resulting from tunneling activity was associated with the flood-stressed trees. Furthermore, living foundresses, eggs, larvae, and pupae were only detected within galleries created in stems of flood-stressed trees. Despite a capability to attack diverse tree genera, X. germanus and X. crassiusculus efficiently distinguished among varying host qualities and preferentially targeted trees based on their intolerance of flood stress. Non-flooded trees were not preferred or successfully colonized. This study demonstrates the host-selection strategy exhibited by X. germanus and X. crassiusculus in non-native habitats involves detection of stress-induced ethanol emission and early colonization of living but weakened trees.

Is There Any Reason to Prefer Cord Blood Instead of Adult Donors for Hematopoietic Stem Cell Transplants?

PubMed

Beksac, Meral

2015-01-01

As cord blood (CB) enables rapid access and tolerance to HLA mismatches, a number of unrelated CB transplants have reached 30,000. Such transplant activity has been the result of international accreditation programs maintaining highly qualified cord blood units (CBUs) reaching more than 600,000 CBUs stored worldwide. Efforts to increase stem cell content or engraftment rate of the graft by ex vivo expansion, modulation by molecules such as fucose, prostaglandin E2 derivative, complement CD26 inhibitors, or CXCR4/CXCL12 axis have been able to accelerate engraftment speed and rate. Furthermore, introduction of reduced intensity conditioning protocols, better HLA matching, and recognition of the importance of HLA-C have improved CB transplants success by decreasing transplant-related mortality. CB progenitor/stem cell content has been compared with adult stem cells revealing higher long-term repopulating capacity compared to bone marrow-mesenchymal stromal cells and lesser oncogenic potential than progenitor-induced stem cells. This chapter summarizes the advantages and disadvantages of CB compared to adult stem cells within the context of stem cell biology and transplantation.

Orchid flowers tolerance to gamma-radiation

NASA Astrophysics Data System (ADS)

Kikuchi, Olivia Kimiko

2000-03-01

Cut flowers are fresh goods that may be treated with fumigants such as methyl bromide to meet the needs of the quarantine requirements of importing countries. Irradiation is a non-chemical alternative to substitute the methyl bromide treatment of fresh products. In this research, different cut orchids were irradiated to examine their tolerance to gamma-rays. A 200 Gy dose did inhibit the Dendrobium palenopsis buds from opening, but did not cause visible damage to opened flowers. Doses of 800 and 1000 Gy were damaging because they provoked the flowers to drop from the stem. Cattleya irradiated with 750 Gy did not show any damage, and were therefore eligible for the radiation treatment. Cymbidium tolerated up to 300 Gy and above this dose dropped prematurely. On the other hand, Oncydium did not tolerate doses above 150 Gy.

Regulation of glutamine synthetase isoforms in two differentially drought-tolerant rice (Oryza sativa L.) cultivars under water deficit conditions.

PubMed

Singh, Kamal Krishna; Ghosh, Shilpi

2013-02-01

KEY MESSAGE : The regulation of GS isoforms by WD was organ specific. Two GS isoforms i.e. OsGS1;1 and OsGS2 were differentially regulated in IR-64 (drought-sensitive) and Khitish (drought-tolerant) cultivars of rice. Water deficit (WD) has adverse effect on rice (Oryza sativa L.) and acclimation requires essential reactions of primary metabolism to continue. Rice plants utilize ammonium as major nitrogen source, which is assimilated into glutamine by the reaction of Glutamine synthetase (GS, EC 6.3.1.2). Rice plants possess one gene (OsGS2) for chloroplastic GS2 and three genes (OsGS1;1, OsGS1;2 and OsGS1;3) for cytosolic GS1. Here, we report the effect of WD on regulation of GS isoforms in drought-sensitive (cv. IR-64) and drought-tolerant (cv. Khitish) rice cultivars. Under WD, total GS activity in root and leaf decreased significantly in IR-64 seedlings in comparison to Khitish seedlings. The reduced GS activity in IR-64 leaf was mainly due to decrease in GS2 activity, which correlated with decrease in corresponding transcript and polypeptide contents. GS1 transcript and polypeptide accumulated in leaf during WD, however, GS1 activity was maintained at a constant level. Total GS activity in stem of both the varieties was insensitive to WD. Among GS1 genes, OsGS1;1 expression was differently regulated by WD in the two rice varieties. Its transcript accumulated more abundantly in IR-64 leaf than in Khitish leaf. Following WD, OsGS1;1 mRNA level in stem and root tissues declined in IR-64 and enhanced in Khitish. A steady OsGS1;2 expression patterns were noted in leaf, stem and root of both the cultivars. Results suggest that OsGS2 and OsGS1;1 expression may contribute to drought tolerance of Khitish cultivar under WD conditions.

Rationale and design of the German-Speaking Myeloma Multicenter Group (GMMG) trial ReLApsE: a randomized, open, multicenter phase III trial of lenalidomide/dexamethasone versus lenalidomide/dexamethasone plus subsequent autologous stem cell transplantation and lenalidomide maintenance in patients with relapsed multiple myeloma.

PubMed

Baertsch, Marc-Andrea; Schlenzka, Jana; Mai, Elias K; Merz, Maximilian; Hillengaß, Jens; Raab, Marc S; Hose, Dirk; Wuchter, Patrick; Ho, Anthony D; Jauch, Anna; Hielscher, Thomas; Kunz, Christina; Luntz, Steffen; Klein, Stefan; Schmidt-Wolf, Ingo G H; Goerner, Martin; Schmidt-Hieber, Martin; Reimer, Peter; Graeven, Ullrich; Fenk, Roland; Salwender, Hans; Scheid, Christof; Nogai, Axel; Haenel, Mathias; Lindemann, Hans W; Martin, Hans; Noppeney, Richard; Weisel, Katja; Goldschmidt, Hartmut

2016-04-25

Despite novel therapeutic agents, most multiple myeloma (MM) patients eventually relapse. Two large phase III trials have shown significantly improved response rates (RR) of lenalidomide/dexamethasone compared with placebo/dexamethasone in relapsed MM (RMM) patients. These results have led to the approval of lenalidomide for RMM patients and lenalidomide/dexamethasone has since become a widely accepted second-line treatment. Furthermore, in RMM patients consolidation with high-dose chemotherapy plus autologous stem cell transplantation has been shown to significantly increase progression free survival (PFS) as compared to cyclophosphamide in a phase III trial. The randomized prospective ReLApsE trial is designed to evaluate PFS after lenalidomide/dexamethasone induction, high-dose chemotherapy consolidation plus autologous stem cell transplantation and lenalidomide maintenance compared with the well-established lenalidomide/dexamethasone regimen in RMM patients. ReLApsE is a randomized, open, multicenter phase III trial in a planned study population of 282 RMM patients. All patients receive three lenalidomide/dexamethasone cycles and--in absence of available stem cells from earlier harvesting--undergo peripheral blood stem cell mobilization and harvesting. Subsequently, patients in arm A continue on consecutive lenalidomide/dexamethasone cycles, patients in arm B undergo high dose chemotherapy plus autologous stem cell transplantation followed by lenalidomide maintenance until discontinuation criteria are met. Therapeutic response is evaluated after the 3(rd) (arm A + B) and the 5(th) lenalidomide/dexamethasone cycle (arm A) or 2 months after autologous stem cell transplantation (arm B) and every 3 months thereafter (arm A + B). After finishing the study treatment, patients are followed up for survival and subsequent myeloma therapies. The expected trial duration is 6.25 years from first patient in to last patient out. The primary endpoint is PFS, secondary endpoints include overall survival (OS), RR, time to best response and the influence of early versus late salvage high dose chemotherapy plus autologous stem cell transplantation on OS. This phase III trial is designed to evaluate whether high dose chemotherapy plus autologous stem cell transplantation and lenalidomide maintenance after lenalidomide/dexamethasone induction improves PFS compared with the well-established continued lenalidomide/dexamethasone regimen in RMM patients. ISRCTN16345835 (date of registration 2010-08-24).

Investigating the mincing method for isolation of adipose-derived stem cells from pregnant women fat.

PubMed

Li, Yuan-Sheng; Chen, Pao-Jen; Wu, Li-Wei; Chou, Pei-Wen; Sun, Li-Yi; Chiou, Tzyy-Wen

2018-02-01

The success of stem cell application in regenerative medicine, usually require a stable source of stem or progenitor cells. Fat tissue represents a good source of stem cells because it is rich in stem cells and there are fewer ethical issues related to the use of such stem cells, unlike embryonic stem cells. Therefore, there has been increased interest in adipose-derived stem cells (ADSCs) for tissue engineering applications. Here, we aim to provide an easy processing method for isolating adult stem cells from human adipose tissue harvested from the subcutaneous fat of the abdominal wall during gynecologic surgery. We used a homogenizer to mince fat and compared the results with those obtained from the traditional cut method involving a sterile scalpel and forceps. Our results showed that our method provides another stable and quality source of stem cells that could be used in cases with a large quantity of fat. Furthermore, we found that pregnancy adipose-derived stem cells (P-ADSCs) could be maintained in vitro for extended periods with a stable population doubling and low senescence levels. P-ADSCs could also differentiate in vitro into adipogenic, osteogenic, chondrogenic, and insulin-producing cells in the presence of lineage-specific induction factors. In conclusion, like human lipoaspirates, adipose tissues obtained from pregnant women contain multipotent cells with better proliferation and showed great promise for use in both stem cell banking studies as well as in stem cell therapy.

Erythroid differentiation of human induced pluripotent stem cells is independent of donor cell type of origin.

PubMed

Dorn, Isabel; Klich, Katharina; Arauzo-Bravo, Marcos J; Radstaak, Martina; Santourlidis, Simeon; Ghanjati, Foued; Radke, Teja F; Psathaki, Olympia E; Hargus, Gunnar; Kramer, Jan; Einhaus, Martin; Kim, Jeong Beom; Kögler, Gesine; Wernet, Peter; Schöler, Hans R; Schlenke, Peter; Zaehres, Holm

2015-01-01

Epigenetic memory in induced pluripotent stem cells, which is related to the somatic cell type of origin of the stem cells, might lead to variations in the differentiation capacities of the pluripotent stem cells. In this context, induced pluripotent stem cells from human CD34(+) hematopoietic stem cells might be more suitable for hematopoietic differentiation than the commonly used fibroblast-derived induced pluripotent stem cells. To investigate the influence of an epigenetic memory on the ex vivo expansion of induced pluripotent stem cells into erythroid cells, we compared induced pluripotent stem cells from human neural stem cells and human cord blood-derived CD34(+) hematopoietic stem cells and evaluated their potential for differentiation into hematopoietic progenitor and mature red blood cells. Although genome-wide DNA methylation profiling at all promoter regions demonstrates that the epigenetic memory of induced pluripotent stem cells is influenced by the somatic cell type of origin of the stem cells, we found a similar hematopoietic induction potential and erythroid differentiation pattern of induced pluripotent stem cells of different somatic cell origin. All human induced pluripotent stem cell lines showed terminal maturation into normoblasts and enucleated reticulocytes, producing predominantly fetal hemoglobin. Differences were only observed in the growth rate of erythroid cells, which was slightly higher in the induced pluripotent stem cells derived from CD34(+) hematopoietic stem cells. More detailed methylation analysis of the hematopoietic and erythroid promoters identified similar CpG methylation levels in the induced pluripotent stem cell lines derived from CD34(+) cells and those derived from neural stem cells, which confirms their comparable erythroid differentiation potential. Copyright© Ferrata Storti Foundation.

40 CFR 180.493 - Dimethomorph; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-propenyl]morpholine, in or on the following commodities: Commodity Parts per million Brassica, head and stem, subgroup 5A 2.0 Brassica, leafy greens, subgroup 5B 20.0 Ginseng 0.90 Grape, raisin 1 6.0 Hop...

Tolerance response of multidrug-resistant Salmonella enterica strains to habituation to Origanum vulgare L. essential oil

PubMed Central

Monte, Daniel F. M.; Tavares, Adassa G.; Albuquerque, Allan R.; Sampaio, Fábio C.; Oliveira, Tereza C. R. M.; Franco, Octavio L.; Souza, Evandro L.; Magnani, Marciane

2014-01-01

Multidrug-resistant Salmonella enterica isolates from human outbreaks or from poultry origin were investigated for their ability to develop direct-tolerance or cross-tolerance to sodium chloride, potassium chloride, lactic acid, acetic acid, and ciprofloxacin after habituation in subinhibitory amounts ( of the minimum inhibitory concentration – (MIC) and of the minimum inhibitory concentration – MIC) of Origanum vulgare L. essential oil (OVEO) at different time intervals. The habituation of S. enterica to OVEO did not induce direct-tolerance or cross-tolerance in the tested strains, as assessed by the modulation of MIC values. However, cells habituated to OVEO maintained or increased susceptibility to the tested antimicrobials agents, with up to fourfold double dilution decrease from previously determined MIC values. This study reports for the first time the non-inductive effect of OVEO on the acquisition of direct-tolerance or cross-tolerance in multidrug-resistant S. enterica strains to antimicrobial agents that are largely used in food preservation, as well as to CIP, the therapeutic drug of salmonellosis. PMID:25566231

Increase of chromium tolerance in Scenedesmus acutus after sulfur starvation: Chromium uptake and compartmentalization in two strains with different sensitivities to Cr(VI).

PubMed

Marieschi, M; Gorbi, G; Zanni, C; Sardella, A; Torelli, A

2015-10-01

In photosynthetic organisms sulfate constitutes the main sulfur source for the biosynthesis of GSH and its precursor Cys. Hence, sulfur availability can modulate the capacity to cope with environmental stresses, a phenomenon known as SIR/SED (Sulfur Induced Resistance or Sulfur Enhanced Defence). Since chromate may compete for sulfate transport into the cells, in this study chromium accumulation and tolerance were investigated in relation to sulfur availability in two strains of the unicellular green alga Scenedesmus acutus with different Cr-sensitivities. Paradoxically, sulfur deprivation has been demonstrated to induce a transient increase of Cr-tolerance in both strains. Sulfur deprivation is known to enhance the sulfate uptake/assimilation pathway leading to important consequences on Cr-tolerance: (i) reduced chromate uptake due to the induction of high affinity sulfate transporters (ii) higher production of cysteine and GSH which can play a role both through the formation of unsoluble complexes and their sequestration in inert compartments. To investigate the role of the above mentioned mechanisms, Cr accumulation in total cells and in different cell compartments (cell wall, membranes, soluble and miscellaneous fractions) was analyzed in both sulfur-starved and unstarved cells. Both strains mainly accumulated chromium in the soluble fraction, but the uptake was higher in the wild-type. In this type a short period of sulfur starvation before Cr(VI) treatment lowered chromium accumulation to the level observed in the unstarved Cr-tolerant strain, in which Cr uptake seems instead less influenced by S-starvation, since no significant decrease was observed. The increase in Cr-tolerance following S-starvation seems thus to rely on different mechanisms in the two strains, suggesting the induction of a mechanism constitutively active in the Cr-tolerant strain, maybe a high affinity sulfate transporter also in the wild-type. Changes observed in the cell wall and membrane fractions suggest a strong involvement of these compartments in Cr-tolerance increase following S-starvation. Copyright © 2015 Elsevier B.V. All rights reserved.

Induction of sensory neurons from neuroepithelial stem cells by the ISX9 small molecule

PubMed Central

Ali, Rouknuddin Qasim; Blomberg, Evelina; Falk, Anna; Ährlund-Richter, Lars; Ulfendahl, Mats

2016-01-01

Hearing impairment most often involves loss of sensory hair cells and auditory neurons. As this loss is permanent in humans, a cell therapy approach has been suggested to replace damaged cells. It is thus of interest to generate lineage restricted progenitor cells appropriate for cell based therapies. Human long-term self-renewing neuroepithelial stem (lt-NES) cell lines exhibit in vitro a developmental potency to differentiate into CNS neural lineages, and importantly lack this potency in vivo, i.e do not form teratomas. Small-molecules-driven differentiation is today an established route obtain specific cell derivatives from stem cells. In this study, we have investigated the effects of three small molecules SB431542, ISX9 and Metformin to direct differentiation of lt-NES cells into sensory neurons. Exposure of lt-NES cells to Metformin or SB431542 did not induce any marked induction of markers for sensory neurons. However, a four days exposure to the ISX9 small molecule resulted in reduced expression of NeuroD1 mRNA as well as enhanced mRNA levels of GATA3, a marker and important player in auditory neuron specification and development. Subsequent culture in the presence of the neurotrophic factors BDNF and NT3 for another seven days yielded a further increase of mRNA expression for GATA3. This regimen resulted in a frequency of up to 25-30% of cells staining positive for Brn3a/Tuj1. We conclude that an approach with ISX9 small molecule induction of lt-NES cells into auditory like neurons may thus be an attractive route for obtaining safe cell replacement therapy of sensorineural hearing loss. PMID:27335699

Induction of CaSR expression circumvents the molecular features of malignant CaSR null colon cancer cells.

PubMed

Singh, Navneet; Chakrabarty, Subhas

2013-11-15

We recently reported on the isolation and characterization of calcium sensing receptor (CaSR) null human colon cancer cells (Singh et al., Int J Cancer 2013; 132: 1996-2005). CaSR null cells possess a myriad of molecular features that are linked to a highly malignant and drug resistant phenotype of colon cancer. The CaSR null phenotype can be maintained in defined human embryonic stem cell culture medium. We now show that the CaSR null cells can be induced to differentiate in conventional culture medium, regained the expression of CaSR with a concurrent reversal of the cellular and molecular features associated with the null phenotype. These features include cellular morphology, expression of colon cancer stem cell markers, expression of survivin and thymidylate synthase and sensitivity to fluorouracil. Other features include the expression of epithelial mesenchymal transition linked molecules and transcription factors, oncogenic miRNAs and tumor suppressive molecule and miRNA. With the exception of cancer stem cell markers, the reversal of molecular features, upon the induction of CaSR expression, is directly linked to the expression and function of CaSR because blocking CaSR induction by shRNA circumvented such reversal. We further report that methylation and demethylation of the CaSR gene promoter underlie CaSR expression. Due to the malignant nature of the CaSR null cells, inclusion of the CaSR null phenotype in disease management may improve on the mortality of this disease. Because CaSR is a robust promoter of differentiation and mediates its action through diverse mechanisms and pathways, inactivation of CaSR may serve as a new paradigm in colon carcinogenesis. Copyright © 2013 UICC.

The mechanisms for lung cancer risk of PM2.5 : Induction of epithelial-mesenchymal transition and cancer stem cell properties in human non-small cell lung cancer cells.

PubMed

Wei, Hongying; Liang, Fan; Cheng, Wei; Zhou, Ren; Wu, Xiaomeng; Feng, Yan; Wang, Yan

2017-11-01

Fine particulate matter (PM 2.5 ) is a major component of air pollutions that are closely associated with increased risk of lung cancer. However, the role of PM 2.5 in the etiology of lung cancer is largely unknown. In this study, we performed acute (24 hours) and chronic (five passages) exposure models to investigate the carcinogenetic mechanisms of PM 2.5 by targeting the induction of epithelial-mesenchymal transition (EMT) and cancer stem cells (CSC) properties in human non-small cell lung cancer cell line A549. We found that both acute and chronic PM 2.5 exposure enhanced cell migration and invasion, decreased mRNA expression of epithelial markers and increased mRNA expression of mesenchymal markers. Chronic PM 2.5 exposure further induced notable EMT morphology and CSC properties, indicating the developing process of cell malignant behaviors from acute to chronic PM 2.5 exposure. CSC properties induced by chronic PM 2.5 exposure characterized with increased cell-surface markers (CD44, ABCG2), self-renewal genes (SOX2 and OCT4), side population cells and neoplastic capacity. Furthermore, the levels of three stemness-associated microRNAs, Let-7a, miR-16 and miR-34a, were found to be significantly downregulated by chronic PM 2.5 exposure, with microarray data analysis from TCGA database showing their lower expression in human lung adenocarcinoma tissues than that in the adjacent normal lung tissues. These data revealed that the induction of EMT and CSC properties were involved in the lung cancer risk of PM 2.5 , and implicated CSC properties and related microRNAs as possible biomarkers for carcinogenicity prediction of PM 2.5 . © 2017 Wiley Periodicals, Inc.

Induction of mice adult bone marrow mesenchymal stem cells into functional motor neuron-like cells.

PubMed

Abdullah, Rafal H; Yaseen, Nahi Y; Salih, Shahlaa M; Al-Juboory, Ahmad Adnan; Hassan, Ayman; Al-Shammari, Ahmed Majeed

2016-11-01

The differentiation of mesenchymal stem cells (MSC) into acetylcholine secreted motor neuron-like cells, followed by elongation of the cell axon, is a promising treatment for spinal cord injury and motor neuron cell dysfunction in mammals. Differentiation is induced through a pre-induction step using Beta- mercaptoethanol (BME) followed by four days of induction with retinoic acid and sonic hedgehog. This process results in a very efficient differentiation of BM-MSCs into motor neuron-like cells. Immunocytochemistry showed that these treated cells had specific motor neural markers: microtubule associated protein-2 and acetylcholine transferase. The ability of these cells to function as motor neuron cells was assessed by measuring acetylcholine levels in a culture media during differentiation. High-performance liquid chromatography (HPLC) showed that the differentiated cells were functional. Motor neuron axon elongation was then induced by adding different concentrations of a nerve growth factor (NGF) to the differentiation media. Using a collagen matrix to mimic the natural condition of neural cells in a three-dimensional model showed that the MSCs were successfully differentiated into motor neuron-like cells. This process can efficiently differentiate MSCs into functional motor neurons that can be used for autologous nervous system therapy and especially for treating spinal cord injuries. Copyright © 2016 Elsevier B.V. All rights reserved.

Molecular Imaging of Human Embryonic Stem Cells Stably Expressing Human PET Reporter Genes After Zinc Finger Nuclease-Mediated Genome Editing.

PubMed

Wolfs, Esther; Holvoet, Bryan; Ordovas, Laura; Breuls, Natacha; Helsen, Nicky; Schönberger, Matthias; Raitano, Susanna; Struys, Tom; Vanbilloen, Bert; Casteels, Cindy; Sampaolesi, Maurilio; Van Laere, Koen; Lambrichts, Ivo; Verfaillie, Catherine M; Deroose, Christophe M

2017-10-01

Molecular imaging is indispensable for determining the fate and persistence of engrafted stem cells. Standard strategies for transgene induction involve the use of viral vectors prone to silencing and insertional mutagenesis or the use of nonhuman genes. Methods: We used zinc finger nucleases to induce stable expression of human imaging reporter genes into the safe-harbor locus adeno-associated virus integration site 1 in human embryonic stem cells. Plasmids were generated carrying reporter genes for fluorescence, bioluminescence imaging, and human PET reporter genes. Results: In vitro assays confirmed their functionality, and embryonic stem cells retained differentiation capacity. Teratoma formation assays were performed, and tumors were imaged over time with PET and bioluminescence imaging. Conclusion: This study demonstrates the application of genome editing for targeted integration of human imaging reporter genes in human embryonic stem cells for long-term molecular imaging. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Signaling-Dependent Control of Apical Membrane Size and Self-Renewal in Rosette-Stage Human Neuroepithelial Stem Cells.

PubMed

Medelnik, Jan-Philip; Roensch, Kathleen; Okawa, Satoshi; Del Sol, Antonio; Chara, Osvaldo; Mchedlishvili, Levan; Tanaka, Elly M

2018-06-05

In the developing nervous system, neural stem cells are polarized and maintain an apical domain facing a central lumen. The presence of apical membrane is thought to have a profound influence on maintaining the stem cell state. With the onset of neurogenesis, cells lose their polarization, and the concomitant loss of the apical domain coincides with a loss of the stem cell identity. Little is known about the molecular signals controlling apical membrane size. Here, we use two neuroepithelial cell systems, one derived from regenerating axolotl spinal cord and the other from human embryonic stem cells, to identify a molecular signaling pathway initiated by lysophosphatidic acid that controls apical membrane size and consequently controls and maintains epithelial organization and lumen size in neuroepithelial rosettes. This apical domain size increase occurs independently of effects on proliferation and involves a serum response factor-dependent transcriptional induction of junctional and apical membrane components. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Phase I Trial Using Induction Ciplatin, Docetaxel, 5-FU and Erlotinib Followed by Cisplatin, Bevacizumab and Erlotinib With Concurrent Radiotherapy for Advanced Head and Neck Cancer.

PubMed

Ahn, Peter H; Machtay, Mitchell; Anne, Pramila R; Cognetti, David; Keane, William M; Wuthrick, Evan; Dicker, Adam P; Axelrod, Rita S

2018-05-01

Bevacizumab (avastin) and erlotinib (tarceva) had shown early clinical activity against head and neck cancer (HNC). We initiated a phase I trial of induction cisplatin, docetaxel, 5-fluorouracil and erlotinib (TPF-E) followed by cisplatin, bevacizumab and erlotinib (PA-E) with radiotherapy (XRT) for advanced HNC. The goal was to determine maximum tolerated erlotinib dose. Eligible patients had stage IVA or higher HNC with good performance status, hematologic, and renal reserve. Two cycles of induction TPF-E were administered. XRT was administered with concurrent weekly cisplatin and bevacizumab every 2 weeks. Initial erlotinib dose was 50 mg daily from start of induction chemotherapy until radiotherapy completion. Erlotinib dose escalations to 100 and 150 mg were planned. Thirteen patients with previously untreated locoregional disease (11 patients) or oligometastatic (2 patients) HNC were enrolled. Totally, 11 of 13 patients completed XRT as planned. Four of 8 patients in cohort 1 (erlotinib 50 mg), 3 of 4 patients in cohort 2 (100 mg), and 0 of 1 patients in cohort 3 (150 mg) completed the regimen. Two patients had significant gastrointestinal complications (bleeding and perforation), and 1 had dose-limiting diarrhea. Maximum tolerated dose was reached at 50 mg erlotinib. At median 23.4 months follow-up, 5 patients (38%) have no evidence of disease, and 2 (15%) have stable but measurable disease. Erlotinib in combination with induction TPF followed by erlotinib, cisplatin, and bevacizumab with XRT is active but toxic. Gastrointestinal toxicities partly caused high rates of study withdrawal. All doses studied in this protocol caused unexpected toxicities and we do not recommend advancement to phase II.

Repurposing phenformin for the targeting of glioma stem cells and the treatment of glioblastoma

PubMed Central

Jiang, Wei; Finniss, Susan; Cazacu, Simona; Xiang, Cunli; Brodie, Ziv; Mikkelsen, Tom; Poisson, Laila; Shackelford, David B.; Brodie, Chaya

2016-01-01

Glioblastoma (GBM) is the most aggressive primary brain tumor with poor prognosis. Here, we studied the effects of phenformin, a mitochondrial complex I inhibitor and more potent chemical analog of the diabetes drug metformin on the inhibition of cell growth and induction of apoptosis of glioma stem cells (GSCs) using both in vitro and in vivo models. Phenformin inhibited the self-renewal of GSCs, decreased the expression of stemness and mesenchymal markers and increased the expression of miR-124, 137 and let-7. Silencing of let-7 abrogated phenformin effects on the self-renewal of GSCs via a pathway associated with inhibition of H19 and HMGA2 expression. Moreover, we demonstrate that phenformin inhibited tumor growth and prolonged the overall survival of mice orthotopically transplanted with GSCs. Combined treatments of phenformin and temozolomide exerted an increased antitumor effect on GSCs in vitro and in vivo. In addition, dichloroacetate, an inhibitor of the glycolysis enzyme pyruvate dehydrogenase kinase, that decreases lactic acidosis induced by biguanides, enhanced phenformin effects on the induction of cell death in GSCs and prolonged the survival of xenograft-bearing mice. Our results demonstrate for the first time that phenformin targets GSCs and can be efficiently combined with current therapies for GBM treatment and GSC eradication. PMID:27486821

Pleiotrophin mediates hematopoietic regeneration via activation of RAS.

PubMed

Himburg, Heather A; Yan, Xiao; Doan, Phuong L; Quarmyne, Mamle; Micewicz, Eva; McBride, William; Chao, Nelson J; Slamon, Dennis J; Chute, John P

2014-11-01

Hematopoietic stem cells (HSCs) are highly susceptible to ionizing radiation-mediated death via induction of ROS, DNA double-strand breaks, and apoptotic pathways. The development of therapeutics capable of mitigating ionizing radiation-induced hematopoietic toxicity could benefit both victims of acute radiation sickness and patients undergoing hematopoietic cell transplantation. Unfortunately, therapies capable of accelerating hematopoietic reconstitution following lethal radiation exposure have remained elusive. Here, we found that systemic administration of pleiotrophin (PTN), a protein that is secreted by BM-derived endothelial cells, substantially increased the survival of mice following radiation exposure and after myeloablative BM transplantation. In both models, PTN increased survival by accelerating the recovery of BM hematopoietic stem and progenitor cells in vivo. PTN treatment promoted HSC regeneration via activation of the RAS pathway in mice that expressed protein tyrosine phosphatase receptor-zeta (PTPRZ), whereas PTN treatment did not induce RAS signaling in PTPRZ-deficient mice, suggesting that PTN-mediated activation of RAS was dependent upon signaling through PTPRZ. PTN strongly inhibited HSC cycling following irradiation, whereas RAS inhibition abrogated PTN-mediated induction of HSC quiescence, blocked PTN-mediated recovery of hematopoietic stem and progenitor cells, and abolished PTN-mediated survival of irradiated mice. These studies demonstrate the therapeutic potential of PTN to improve survival after myeloablation and suggest that PTN-mediated hematopoietic regeneration occurs in a RAS-dependent manner.

Repurposing phenformin for the targeting of glioma stem cells and the treatment of glioblastoma.

PubMed

Jiang, Wei; Finniss, Susan; Cazacu, Simona; Xiang, Cunli; Brodie, Ziv; Mikkelsen, Tom; Poisson, Laila; Shackelford, David B; Brodie, Chaya

2016-08-30

Glioblastoma (GBM) is the most aggressive primary brain tumor with poor prognosis. Here, we studied the effects of phenformin, a mitochondrial complex I inhibitor and more potent chemical analog of the diabetes drug metformin on the inhibition of cell growth and induction of apoptosis of glioma stem cells (GSCs) using both in vitro and in vivo models. Phenformin inhibited the self-renewal of GSCs, decreased the expression of stemness and mesenchymal markers and increased the expression of miR-124, 137 and let-7. Silencing of let-7 abrogated phenformin effects on the self-renewal of GSCs via a pathway associated with inhibition of H19 and HMGA2 expression. Moreover, we demonstrate that phenformin inhibited tumor growth and prolonged the overall survival of mice orthotopically transplanted with GSCs. Combined treatments of phenformin and temozolomide exerted an increased antitumor effect on GSCs in vitro and in vivo. In addition, dichloroacetate, an inhibitor of the glycolysis enzyme pyruvate dehydrogenase kinase, that decreases lactic acidosis induced by biguanides, enhanced phenformin effects on the induction of cell death in GSCs and prolonged the survival of xenograft-bearing mice. Our results demonstrate for the first time that phenformin targets GSCs and can be efficiently combined with current therapies for GBM treatment and GSC eradication.

A comparison of sputum induction methods: ultrasonic vs compressed-air nebulizer and hypertonic vs isotonic saline inhalation.

PubMed

Loh, L C; Eg, K P; Puspanathan, P; Tang, S P; Yip, K S; Vijayasingham, P; Thayaparan, T; Kumar, S

2004-03-01

Airway inflammation can be demonstrated by the modem method of sputum induction using ultrasonic nebulizer and hypertonic saline. We studied whether compressed-air nebulizer and isotonic saline which are commonly available and cost less, are as effective in inducing sputum in normal adult subjects as the above mentioned tools. Sixteen subjects underwent weekly sputum induction in the following manner: ultrasonic nebulizer (Medix Sonix 2000, Clement Clarke, UK) using hypertonic saline, ultrasonic nebulizer using isotonic saline, compressed-air nebulizer (BestNeb, Taiwan) using hypertonic saline, and compressed-air nebulizer using isotonic saline. Overall, the use of an ultrasonic nebulizer and hypertonic saline yielded significantly higher total sputum cell counts and a higher percentage of cell viability than compressed-air nebulizers and isotonic saline. With the latter, there was a trend towards squamous cell contaminations. The proportion of various sputum cell types was not significantly different between the groups, and the reproducibility in sputum macrophages and neutrophils was high (Intraclass correlation coefficient, r [95%CI]: 0.65 [0.30-0.91] and 0.58 [0.22-0.89], p < 0.001). Overall changes in median FEV, were small and comparable between all groups. Induction using ultrasonic nebulizers together with hypertonic saline was generally less well tolerated than compressed-air nebulizers and isotonic saline. We conclude that in normal subjects, although both nebulizers and saline types can induce sputum with reproducible cellular profile, ultrasonic nebulizers and hypertonic saline are more effective but less well tolerated.

Mesenteric lymph node stromal cell‐derived extracellular vesicles contribute to peripheral de novo induction of Foxp3+ regulatory T cells

PubMed Central

Pasztoi, Maria; Pezoldt, Joern; Beckstette, Michael; Lipps, Christoph; Wirth, Dagmar; Rohde, Manfred; Paloczi, Krisztina; Buzas, Edit Iren

2017-01-01

Abstract Intestinal regulatory T cells (Tregs) are fundamental in peripheral tolerance toward commensals and food‐borne antigens. Accordingly, gut‐draining mesenteric lymph nodes (mLNs) represent a site of efficient peripheral de novo Treg induction when compared to skin‐draining peripheral LNs (pLNs), and we had recently shown that LN stromal cells substantially contribute to this process. Here, we aimed to unravel the underlying molecular mechanisms and generated immortalized fibroblastic reticular cell lines (iFRCs) from mLNs and pLNs, allowing unlimited investigation of this rare stromal cell subset. In line with our previous findings, mLN‐iFRCs showed a higher Treg‐inducing capacity when compared to pLN‐iFRCs. RNA‐seq analysis focusing on secreted molecules revealed a more tolerogenic phenotype of mLN‐ as compared to pLN‐iFRCs. Remarkably, mLN‐iFRCs produced substantial numbers of microvesicles (MVs) that carried elevated levels of TGF‐β when compared to pLN‐iFRC‐derived MVs, and these novel players of intercellular communication were shown to be responsible for the tolerogenic properties of mLN‐iFRCs. Thus, stromal cells originating from mLNs contribute to peripheral tolerance by fostering de novo Treg induction using TGF‐β‐carrying MVs. This finding provides novel insights into the subcellular/molecular mechanisms of de novo Treg induction and might serve as promising tool for future therapeutic applications to treat inflammatory disorders. PMID:28833065

Study on suitable for regeneration system of genetic transformation of kiwifruit

NASA Astrophysics Data System (ADS)

Yuan, Yun Xiang

2011-02-01

The stems of Actinidia Qinmei were taken as explants and induced callus formation after having gained the aseptic seedling in primary culture successfully, and then the calli were placed on different combinations regeneration medium. The results showed that the induction medium added 1 mg/L 6-BA and 0.1 mg/L NAA was beneficial to the callus induction in dark culture condition. The suitable regeneration medium was MS containing 2.0 mg/L 6BA, 0.1 mg/L NAA and 3% (W/V) sucrose, it could improve obviously the frequency of regenerated shoots. This method separated the callus induction from shoot regeneration and obtained more callus to optimize the regenerated medium, and also was advantageous to Kiwifruit genetic transformation.

Controlling plant architecture by manipulation of gibberellic acid signalling in petunia

USDA-ARS?s Scientific Manuscript database

Gibberellic acid (GA), a plant hormone, regulates many crucial growth and developmental processes, including seed germination, leaf expansion, induction of flowering and stem elongation. A common problem in the production of ornamental potted plants is undesirably tall growth, so inhibitors of gibbe...

Hippo/YAP-mediated rigidity-dependent motor neuron differentiation of human pluripotent stem cells

NASA Astrophysics Data System (ADS)

Sun, Yubing; Yong, Koh Meng Aw; Villa-Diaz, Luis G.; Zhang, Xiaoli; Chen, Weiqiang; Philson, Renee; Weng, Shinuo; Xu, Haoxing; Krebsbach, Paul H.; Fu, Jianping

2014-06-01

Our understanding of the intrinsic mechanosensitive properties of human pluripotent stem cells (hPSCs), in particular the effects that the physical microenvironment has on their differentiation, remains elusive. Here, we show that neural induction and caudalization of hPSCs can be accelerated by using a synthetic microengineered substrate system consisting of poly(dimethylsiloxane) micropost arrays (PMAs) with tunable mechanical rigidities. The purity and yield of functional motor neurons derived from hPSCs within 23 days of culture using soft PMAs were improved more than fourfold and tenfold, respectively, compared with coverslips or rigid PMAs. Mechanistic studies revealed a multi-targeted mechanotransductive process involving Smad phosphorylation and nucleocytoplasmic shuttling, regulated by rigidity-dependent Hippo/YAP activities and actomyosin cytoskeleton integrity and contractility. Our findings suggest that substrate rigidity is an important biophysical cue influencing neural induction and subtype specification, and that microengineered substrates can thus serve as a promising platform for large-scale culture of hPSCs.

Elemental bioimaging by means of LA-ICP-OES: investigation of the calcium, sodium and potassium distribution in tobacco plant stems and leaf petioles.

PubMed

Thyssen, G M; Holtkamp, M; Kaulfürst-Soboll, H; Wehe, C A; Sperling, M; von Schaewen, A; Karst, U

2017-06-21

Laser ablation-inductively coupled plasma-optical emission spectroscopy (LA-ICP-OES) is presented as a valuable tool for elemental bioimaging of alkali and earth alkali elements in plants. Whereas LA-ICP-OES is commonly used for micro analysis of solid samples, laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) has advanced to the gold standard for bioimaging. However, especially for easily excitable and ubiquitous elements such as alkali and earth alkali elements, LA-ICP-OES holds some advantages regarding simultaneous detection, costs, contamination, and user-friendliness. This is demonstrated by determining the calcium, sodium and potassium distribution in tobacco plant stem and leaf petiole tissues. A quantification of the calcium contents in a concentration range up to 1000 μg g -1 using matrix-matched standards is presented as well. The method is directly compared to a LA-ICP-MS approach by analyzing parallel slices of the same samples.

Effect of autologous platelet-rich plasma on the chondrogenic differentiation of rabbit adipose-derived stem cells in vitro

PubMed Central

TANG, XIAO-BO; DONG, PEI-LONG; WANG, JIAN; ZHOU, HAI-YANG; ZHANG, HAI-XIANG; WANG, SHAN-ZHENG

2015-01-01

This study aimed to isolate rabbit adipose-derived stem cells (ADSCs) and explore the potential of platelet-rich plasma (PRP) in the chondrogenic differentiation of ADSCs, thereby potentially providing a new approach for the repair and regeneration of cartilage injury. Rabbit ADSCs were isolated and characterized by induction towards adipogenic, osteogenic and chondrogenic lineages in vitro. The isolated ADSCs were also cultured with or without 10% PRP. Immunofluorescence staining, toluidine blue staining and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were used to detect type II collagen (Col II) and aggrecan (AGC) expression. Col II immunofluorescence staining and toluidine blue staining indicated that following induction by autologous PRP, ADSCs manifested Col II and AGC expression. The expression of Col II and AGC mRNA was significantly upregulated in the PRP-treated cells when compared with that in control cells. Autologous PRP produced by laboratory centrifugation was able to promote the chondrogenic differentiation of rabbit ADSCs in vitro. PMID:26622340

Sam68 Allows Selective Targeting of Human Cancer Stem Cells.

PubMed

Benoit, Yannick D; Mitchell, Ryan R; Risueño, Ruth M; Orlando, Luca; Tanasijevic, Borko; Boyd, Allison L; Aslostovar, Lili; Salci, Kyle R; Shapovalova, Zoya; Russell, Jennifer; Eguchi, Masakatsu; Golubeva, Diana; Graham, Monica; Xenocostas, Anargyros; Trus, Michael R; Foley, Ronan; Leber, Brian; Collins, Tony J; Bhatia, Mickie

2017-07-20

Targeting of human cancer stem cells (CSCs) requires the identification of vulnerabilities unique to CSCs versus healthy resident stem cells (SCs). Unfortunately, dysregulated pathways that support transformed CSCs, such as Wnt/β-catenin signaling, are also critical regulators of healthy SCs. Using the ICG-001 and CWP family of small molecules, we reveal Sam68 as a previously unappreciated modulator of Wnt/β-catenin signaling within CSCs. Disruption of CBP-β-catenin interaction via ICG-001/CWP induces the formation of a Sam68-CBP complex in CSCs that alters Wnt signaling toward apoptosis and differentiation induction. Our study identifies Sam68 as a regulator of human CSC vulnerability. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

The homologous HD-Zip I transcription factors HaHB1 and AtHB13 confer cold tolerance via the induction of pathogenesis-related and glucanase proteins.

PubMed

Cabello, Julieta V; Arce, Agustín L; Chan, Raquel L

2012-01-01

Plants deal with cold temperatures via different signal transduction pathways. The HD-Zip I homologous transcription factors HaHB1 from sunflower and AtHB13 from Arabidopsis were identified as playing a key role in such cold response. The expression patterns of both genes were analyzed indicating an up-regulation by low temperatures. When these genes were constitutively expressed in Arabidopsis, the transgenic plants showed similar phenotypes including cell membrane stabilization under freezing treatments and cold tolerance. An exploratory transcriptomic analysis of HaHB1 transgenic plants indicated that several transcripts encoding glucanases and chitinases were induced. Moreover, under freezing conditions some proteins accumulated in HaHB1 plants apoplasts and these extracts exerted antifreeze activity in vitro. Three genes encoding two glucanases and a chitinase were overexpressed in Arabidopsis and these plants were able to tolerate freezing temperatures. All the obtained transgenic plants exhibited cell membrane stabilization after a short freezing treatment. Finally, HaHB1 and AtHB13 were used to transiently transform sunflower and soybean leading to the up-regulation of HaHB1/AtHB13-target homologues thus indicating the conservation of cold response pathways. We propose that HaHB1 and AtHB13 are involved in plant cold tolerance via the induction of proteins able to stabilize cell membranes and inhibit ice growth. © 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.

The dehydration stress of couch grass is associated with its lipid metabolism, the induction of transporters and the re-programming of development coordinated by ABA.

PubMed

Janská, Anna; Svoboda, Pavel; Spiwok, Vojtěch; Kučera, Ladislav; Ovesná, Jaroslava

2018-05-02

The wild relatives of crop species represent a potentially valuable source of novel genetic variation, particularly in the context of improving the crop's level of tolerance to abiotic stress. The mechanistic basis of these tolerances remains largely unexplored. Here, the focus was to characterize the transcriptomic response of the nodes (meristematic tissue) of couch grass (a relative of barley) to dehydration stress, and to compare it to that of the barley crown formed by both a drought tolerant and a drought sensitive barley cultivar. Many of the genes up-regulated in the nodes by the stress were homologs of genes known to be mediated by abscisic acid during the response to drought, or were linked to either development or lipid metabolism. Transporters also featured prominently, as did genes acting on root architecture. The resilience of the couch grass node arise from both their capacity to develop an altered, more effective root architecture, but also from their formation of a lipid barrier on their outer surface and their ability to modify both their lipid metabolism and transporter activity when challenged by dehydration stress. Our analysis revealed the nature of dehydration stress response in couch grass. We suggested the tolerance is associated with lipid metabolism, the induction of transporters and the re-programming of development coordinated by ABA. We also proved the applicability of barley microarray for couch grass stress-response analysis.

Natural variation reveals relationships between pre-stress carbohydrate nutritional status and subsequent responses to xenobiotic and oxidative stress in Arabidopsis thaliana.

PubMed

Ramel, Fanny; Sulmon, Cécile; Gouesbet, Gwenola; Couée, Ivan

2009-12-01

Soluble sugars are involved in responses to stress, and act as signalling molecules that activate specific or hormone cross-talk transduction pathways. Thus, exogenous sucrose treatment efficiently induces tolerance to the herbicide atrazine in Arabidopsis thaliana plantlets, at least partially through large-scale modifications of expression of stress-related genes. Availability of sugars in planta for stress responses is likely to depend on complex dynamics of soluble sugar accumulation, sucrose-starch partition and organ allocation. The question of potential relationships between endogenous sugar levels and stress responses to atrazine treatment was investigated through analysis of natural genetic accessions of A. thaliana. Parallel quantitative and statistical analysis of biochemical parameters and of stress-sensitive physiological traits was carried out on a set of 11 accessions. Important natural variation was found between accessions of A. thaliana in pre-stress shoot endogenous sugar levels and responses of plantlets to subsequent atrazine stress. Moreover, consistent trends and statistically significant correlations were detected between specific endogenous sugar parameters, such as the pre-stress end of day sucrose level in shoots, and physiological markers of atrazine tolerance. These significant relationships between endogenous carbohydrate metabolism and stress response therefore point to an important integration of carbon nutritional status and induction of stress tolerance in plants. The specific correlation between pre-stress sucrose level and greater atrazine tolerance may reflect adaptive mechanisms that link sucrose accumulation, photosynthesis-related stress and sucrose induction of stress defences.

A composite score associated with spontaneous operational tolerance in kidney transplant recipients.

PubMed

Danger, Richard; Chesneau, Mélanie; Paul, Chloé; Guérif, Pierrick; Durand, Maxim; Newell, Kenneth A; Kanaparthi, Sai; Turka, Laurence A; Soulillou, Jean-Paul; Houlgatte, Rémi; Giral, Magali; Ramstein, Gérard; Brouard, Sophie

2017-06-01

New challenges in renal transplantation include using biological information to devise a useful clinical test for discerning high- and low-risk patients for individual therapy and ascertaining the best combination and appropriate dosages of drugs. Based on a 20-gene signature from a microarray meta-analysis performed on 46 operationally tolerant patients and 266 renal transplant recipients with stable function, we applied the sparse Bolasso methodology to identify a minimal and robust combination of six genes and two demographic parameters associated with operational tolerance. This composite score of operational tolerance discriminated operationally tolerant patients with an area under the curve of 0.97 (95% confidence interval 0.94-1.00). The score was not influenced by immunosuppressive treatment, center of origin, donor type, or post-transplant lymphoproliferative disorder history of the patients. This composite score of operational tolerance was significantly associated with both de novo anti-HLA antibodies and tolerance loss. It was validated by quantitative polymerase chain reaction using independent samples and demonstrated specificity toward a model of tolerance induction. Thus, our score would allow clinicians to improve follow-up of patients, paving the way for individual therapy. Copyright © 2017 International Society of Nephrology. All rights reserved.

A composite score associated with spontaneous operational tolerance in kidney transplant recipients

PubMed Central

Danger, Richard; Chesneau, Mélanie; Paul, Chloé; Guérif, Pierrick; Durand, Maxim; Newell, Kenneth A; Kanaparthi, Sai; Turka, Laurence A; Soulillou, Jean-Paul; Houlgatte, Rémi; Giral, Magali; Ramstein, Gérard; Brouard, Sophie

2017-01-01

New challenges in renal transplantation include using biological information to devise a useful clinical test for discerning high- and low-risk patients for individual therapy and ascertaining the best combination and appropriate dosages of drugs. Based on a 20-gene signature from a microarray meta-analysis performed on 46 operationally tolerant patients and 266 renal transplanted recipients with stable function, we applied the sparse Bolasso methodology to identify a minimal and robust combination of six genes and two demographic parameters associated with operational tolerance. This composite score of operational tolerance discriminated operationally tolerant patients with an area under the curve of 0.97 (95% confidence interval 0.94–1.00). The score was not influenced by immunosuppressive treatment, center of origin, donor type, or post-transplant lymphoproliferative disorder history of the patients. This composite score of operational tolerance was significantly associated with both de novo anti-HLA antibodies and tolerance loss. It was validated by quantitative polymerase chain reaction using independent samples and demonstrated specificity toward a model of tolerance induction. Thus, our score would allow clinicians to improve follow-up of patients, paving the way for individual therapy. PMID:28242033

Changes in carbohydrate content and membrane stability of two ecotypes of Calamagrostis arundinacea growing at different elevations in the drawdown zone of the Three Gorges Reservoir.

PubMed

Lei, Shutong; Zeng, Bo; Yuan, Zhi; Su, Xiaolei

2014-01-01

The Three Gorges project has caused many ecosystem problems. Ecological restoration using readily-available plants is an effective way of mitigating environmental impacts. Two perennial submergence-tolerant ecotypes of Calamagrostis arundinacea were planted in an experimental field in the drawdown zone. Responses of the two plant ecotypes to flooding stress in the drawdown zone were unknown. Carbohydrate content and membrane stability, two key factors for survival of plants under flooding stress, of two ecotypes (designated "dwarf" and "green") of C. arundinacea growing at different elevations of the drawdown zone were investigated. Live stems (LS) and dead stems (DS) of the two plant ecotypes at eight elevations (175, 170, 162, 160, 158, 155, 152 m and 149 m) were sampled. Contents of soluble sugar, starch and malondialdehyde (MDA), as well as plasma membrane permeability of live stems were measured. The lowest elevations for survival of dwarf and green C. arundinacea were 160 m and 158 m, respectively. Soluble sugar content of live stems of both ecotypes decreased with elevation, with amounts from an elevation of 170 m being lower than from an elevation of 175 m. MDA content and plasma membrane permeability in live stems of green C. arundinacea did not increase with the decrease in elevation, while these measures in dwarf C. arundinacea from an elevation of 162 m were significantly higher than from an elevation of 175 m. Carbohydrate content, especially soluble sugar content, in both ecotypes was more sensitive to flooding stress than membrane stability. Green C. arundinacea had a higher tolerance to submergence than dwarf C. arundinacea, and thus green C. arundinacea can be planted at lower elevations than dwarf C. arundinacea.

40 CFR 180.532 - Cyprodinil; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... commodities: Commodity Parts per million Almond 0.02 Almond, hulls 8.0 Apple, wet pomace 0.15 Avocado 1.2 Bean, dry 0.6 Bean, succulent 0.6 Brassica, head and stem, subgroup 5A 1.0 Brassica, leafy greens, subgroup...

Histone Deacetylase Inhibitors in Cell Pluripotency, Differentiation, and Reprogramming

PubMed Central

Kretsovali, Androniki; Hadjimichael, Christiana; Charmpilas, Nikolaos

2012-01-01

Histone deacetylase inhibitors (HDACi) are small molecules that have important and pleiotropic effects on cell homeostasis. Under distinct developmental conditions, they can promote either self-renewal or differentiation of embryonic stem cells. In addition, they can promote directed differentiation of embryonic and tissue-specific stem cells along the neuronal, cardiomyocytic, and hepatic lineages. They have been used to facilitate embryo development following somatic cell nuclear transfer and induced pluripotent stem cell derivation by ectopic expression of pluripotency factors. In the latter method, these molecules not only increase effectiveness, but can also render the induction independent of the oncogenes c-Myc and Klf4. Here we review the molecular pathways that are involved in the functions of HDAC inhibitors on stem cell differentiation and reprogramming of somatic cells into pluripotency. Deciphering the mechanisms of HDAC inhibitor actions is very important to enable their exploitation for efficient and simple tissue regeneration therapies. PMID:22550500

Effect of concentrated growth factors on beagle periodontal ligament stem cells in vitro.

PubMed

Yu, Bohan; Wang, Zuolin

2014-01-01

Identifying a reliable and effective cytokine or growth factor group has been the focus of stem cell osteogenic induction studies. Concentrated growth factors (CGFs) as the novel generation of platelet concentrate products, appear to exhibit a superior clinical and biotechnological application potential, however, there are few studies that have demonstrated this effect. This study investigated the proliferation and differentiation of periodontal ligament stem cells (PDLSCs) co‑cultured with CGFs. The rate of proliferation was analyzed by cell counting and an MTT assay. Mineralization nodule counts, alkaline phosphatase activity detection, qPCR, western blot analysis and immunohistochemistry were used to analyze mineralization effects. The results showed that CGF significantly promoted the proliferation of PDLSCs, and exhibited a dose‑dependent effect on the activation and differentiation of the stem cells. The application of CGF on PDLSC proliferation and osteoinduction may offer numerous clinical and biotechnological application strategies.

Failure of transplantation tolerance induction by autologous regulatory T cells in the pig-to-non-human primate islet xenotransplantation model.

PubMed

Shin, Jun-Seop; Min, Byoung-Hoon; Kim, Jong-Min; Kim, Jung-Sik; Yoon, Il Hee; Kim, Hyun Je; Kim, Yong-Hee; Jang, Jae Yool; Kang, Hee Jung; Lim, Dong-Gyun; Ha, Jongwon; Kim, Sang-Joon; Park, Chung-Gyu

2016-07-01

Islet allotransplantation is a promising way to treat some type 1 diabetic (T1D) patients with frequent hypoglycemic unawareness, and islet xenotransplantation is emerging to overcome the problem of donor organ shortage. Our recent study showing reproducible long-term survival of porcine islets in non-human primates (NHPs) allows us to examine whether autologous regulatory T-cell (Treg) infusion at peri-transplantation period would induce transplantation tolerance in xenotransplantation setting. Two diabetic rhesus monkeys were transplanted with porcine islets from wild-type adult Seoul National University (SNU) miniature pigs with immunosuppression by anti-thymoglobulin (ATG), cobra venom factor, anti-CD154 monoclonal antibody (mAb), and sirolimus. CD4(+) CD25(high) CD127(low) autologous regulatory T cells from the recipients were isolated, ex vivo expanded, and infused at the peri-transplantation period. Blood glucose and porcine C-peptide from the recipients were measured up to 1000 days. Maintenance immunosuppressants including a CD40-CD154 blockade were deliberately discontinued to confirm whether transplantation tolerance was induced by adoptively transferred Tregs. After pig islet transplantation via portal vein, blood glucose levels of diabetic recipients became normalized and maintained over 6 months while in immunosuppressive maintenance with a CD40-CD154 blockade and sirolimus. However, the engrafted pig islets in the long-term period were fully rejected by activated immune cells, particularly T cells, when immunosuppressants were stopped, showing a failure of transplantation tolerance induction by autologous Tregs. Taken together, autologous Tregs infused at the peri-transplantation period failed to induce transplantation tolerance in pig-to-NHP islet xenotransplantation setting. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Enhanced expression of Rubisco activase splicing variants differentially affects Rubisco activity during low temperature treatment in Lolium perenne.

PubMed

Jurczyk, Barbara; Pociecha, Ewa; Grzesiak, Maciej; Kalita, Katarzyna; Rapacz, Marcin

2016-07-01

Alternative splicing of the Rubisco activase gene was shown to be a point for optimization of photosynthetic carbon assimilation. It can be expected to be a stress-regulated event that depends on plant freezing tolerance. The aim of the study was to examine the relationships among Rubisco activity, the expression of two Rubisco activase splicing variants and photoacclimation to low temperature. The experiment was performed on two Lolium perenne genotypes with contrasting levels of freezing tolerance. The study investigated the effect of pre-hardening (15°C) and cold acclimation (4°C) on net photosynthesis, photosystem II photochemical activity, Rubisco activity and the expression of two splicing variants of the Rubisco activase gene. The results showed an induction of Rubisco activity at both 15°C and 4°C only in a highly freezing-tolerant genotype. The enhanced Rubisco activity after pre-hardening corresponded to increased expression of the splicing variant representing the large isoform, while the increase in Rubisco activity during cold acclimation was due to the activation of both transcript variants. These boosts in Rubisco activity also corresponded to an activation of non-photochemical mechanism of photoacclimation induced at low temperature exclusively in the highly freezing-tolerant genotype. In conclusion, enhanced expression of Rubisco activase splicing variants caused an increase in Rubisco activity during pre-hardening and cold acclimation in the more freezing-tolerant Lolium perenne genotype. The induction of the transcript variant representing the large isoform may be an important element of increasing the carbon assimilation rate supporting the photochemical mechanism of photosynthetic acclimation to cold. Copyright © 2016 Elsevier GmbH. All rights reserved.

Genome-wide transcriptomic analysis of response to low temperature reveals candidate genes determining divergent cold-sensitivity of maize inbred lines.

PubMed

Sobkowiak, Alicja; Jończyk, Maciej; Jarochowska, Emilia; Biecek, Przemysław; Trzcinska-Danielewicz, Joanna; Leipner, Jörg; Fronk, Jan; Sowiński, Paweł

2014-06-01

Maize, despite being thermophyllic due to its tropical origin, demonstrates high intraspecific diversity in cold-tolerance. To search for molecular mechanisms of this diversity, transcriptomic response to cold was studied in two inbred lines of contrasting cold-tolerance. Microarray analysis was followed by extensive statistical elaboration of data, literature data mining, and gene ontology-based classification. The lines used had been bred earlier specifically for determination of QTLs for cold-performance of photosynthesis. This allowed direct comparison of present transcriptomic data with the earlier QTL mapping results. Cold-treated (14 h at 8/6 °C) maize seedlings of cold-tolerant ETH-DH7 and cold-sensitive ETH-DL3 lines at V3 stage showed strong, consistent response of the third leaf transcriptome: several thousand probes showed similar, statistically significant change in both lines, while only tens responded differently in the two lines. The most striking difference between the responses of the two lines to cold was the induction of expression of ca. twenty genes encoding membrane/cell wall proteins exclusively in the cold-tolerant ETH-DH7 line. The common response comprised mainly repression of numerous genes related to photosynthesis and induction of genes related to basic biological activity: transcription, regulation of gene expression, protein phosphorylation, cell wall organization. Among the genes showing differential response, several were close to the QTL regions identified in earlier studies with the same inbred lines and associated with biometrical, physiological or biochemical parameters. These transcripts, including two apparently non-protein-coding ones, are particularly attractive candidates for future studies on mechanisms determining divergent cold-tolerance of inbred maize lines.

IL-5 promotes induction of antigen-specific CD4+CD25+ T regulatory cells that suppress autoimmunity.

PubMed

Tran, Giang T; Hodgkinson, Suzanne J; Carter, Nicole M; Verma, Nirupama D; Plain, Karren M; Boyd, Rochelle; Robinson, Catherine M; Nomura, Masaru; Killingsworth, Murray; Hall, Bruce M

2012-05-10

Immune responses to foreign and self-Ags can be controlled by regulatory T cells (Tregs) expressing CD4 and IL-2Rα chain (CD25). Defects in Tregs lead to autoimmunity, whereas induction of Ag-specific CD4+CD25+ Tregs restores tolerance. Ag-specific CD4+CD25+ FOXP3+Tregs activated by the T helper type 2 (Th2) cytokine, IL-4, and specific alloantigen promote allograft tolerance. These Tregs expressed the specific IL-5Rα and in the presence of IL-5 proliferate to specific but not third-party Ag. These findings suggest that recombinant IL-5 (rIL-5) therapy may promote Ag-specific Tregs to mediate tolerance. This study showed normal CD4+CD25+ Tregs cultured with IL-4 and an autoantigen expressed Il-5rα. Treatment of experimental autoimmune neuritis with rIL-5 markedly reduced clinical paralysis, weight loss, demyelination, and infiltration of CD4+ (Th1 and Th17) CD8+ T cells and macrophages in nerves. Clinical improvement was associated with expansion of CD4+CD25+FOXP3+ Tregs that expressed Il-5rα and proliferated only to specific autoantigen that was enhanced by rIL-5. Depletion of CD25+ Tregs or blocking of IL-4 abolished the benefits of rIL-5. Thus, rIL-5 promoted Ag-specific Tregs, activated by autoantigen and IL-4, to control autoimmunity. These findings may explain how Th2 responses, especially to parasitic infestation, induce immune tolerance. rIL-5 therapy may be able to induce Ag-specific tolerance in autoimmunity.

Tolerance - One Transplant for Life

PubMed Central

Kawai, Tatsuo; Leventhal, Joseph; Madsen, Joren C.; Strober, Samuel; Turka, Laurence A.; Wood, Kathryn J.

2014-01-01

A recent TTS workshop was convened to address the question: “What do we need to have in place to make tolerance induction protocols a “standard of care” for organ transplant recipients over the next decade?” In a productive two day meeting there was wide-ranging discussion on a broad series of topics resulting in five consensus recommendations: (1) Establish a registry of results for patients enrolled in tolerance trials; (2) Establish standardized protocols for sample collection and storage; (3) Establish standardized biomarkers and assays; (4) Include children aged 12 and older in protocols that have been validated in adults; (5) a task force to engage third party payers in discussions of how to fund tolerance trials. Future planned workshops will focus on progress in implementing these recommendations and identifying other steps that the community needs to take. PMID:24926829

Stem-cell-activated organ following ultrasound exposure: better transplant option for organ transplantation.

PubMed

Wang, Sen; Li, Yu; Ji, Ying-Chang; Lin, Chang-Min; Man, Cheng; Zheng, Xiao-Xuan

2010-01-01

Although doctors try their best to protect transplants during surgery, there remain great challenges for the higher survival rate and less rejection of transplants after organ transplantation. Growing evidence indicates that the stem cells could function after injury rather than aging, implying that suitable injury may activate the stem cells of damaged organs. Furthermore, it has been revealed that stem cells can be used to induce tolerance in transplantation and the ultrasound has great biological effects on organs. Basing on these facts, we hypothesize that the stem cells within the transplants can be activated by ultrasound with high-frequency and medium-intensity. Therefore, the stem-cell-activated organs (SCAO) can be derived, and the SCAO will be better transplant option for organ transplantation. We postulate the ultrasound can change the molecular activity and/or quantity of the stem cells, the membrane permeability, the cell-cell junctions, and their surrounding microenvironments. As a result, the stem cells are activated, and the SCAO will acquire more regenerative capacity and less rejection. In the paper, we also discuss the process, methods and models for verifying the theory, and the consequences. We believe the theory may provide a practical method for the clinical application of the ultrasound and stem cells in organ transplantation.

Breaking tolerance to self, circulating natural killer cells expressing inhibitory KIR for non-self HLA exhibit effector function after T cell-depleted allogeneic hematopoietic cell transplantation.

PubMed

Yu, Junli; Venstrom, Jeffrey M; Liu, Xiao-Rong; Pring, James; Hasan, Reenat S; O'Reilly, Richard J; Hsu, Katharine C

2009-04-16

Alloreactive natural killer (NK) cells are an important influence on hematopoietic stem cell transplantation (HSCT) outcome. In HLA-mismatched HSCT, alloreactivity occurs when licensed donor NK cells expressing inhibitory killer Ig-like receptors (KIR) for donor MHC class I ligands recognize the lack of the class I ligands in the mismatched recipient ("missing self"). Studies in HLA-matched HSCT, however, have also demonstrated improved outcome in patients lacking class I ligands for donor inhibitory KIR ("missing ligand"), indicating that classically nonlicensed donor NK cells expressing KIR for non-self MHC class I ligands may exhibit functional competence in HSCT. We examined NK function in 16 recipients of T cell-depleted allografts from HLA-identical or KIR-ligand matched donors after myeloablative therapy. After HSCT, nonlicensed NK cells expressing inhibitory KIR for non-self class I exhibit robust intracellular IFN-gamma and cytotoxic response to target cells lacking cognate ligand, gradually becoming tolerized to self by day 100. These findings could not be correlated with cytokine environment or phenotypic markers of NK development, nor could they be attributed to non-KIR receptors such as CD94/NKG2A. These findings confirm that NK alloreactivity can occur in HLA-matched HSCT, where tolerance to self is either acquired by the stem cell-derived NK cell after exiting the bone marrow or where tolerance to self can be temporarily overcome.

Effects of Mulching Tolerant Plant Straw on Soil Surface on Growth and Cadmium Accumulation of Galinsoga parviflora

PubMed Central

Lin, Lijin; Liao, Ming’an; Ren, Yajun; Luo, Li; Zhang, Xiao; Yang, Daiyu; He, Jing

2014-01-01

Pot and field experiments were conducted to study the effects of mulching with straw of cadmium (Cd) tolerant plants (Ranunculus sieboldii, Mazus japonicus, Clinopodium confine and Plantago asiatica) on growth and Cd accumulation of Galinsoga parviflora in Cd-contaminated soil. In the pot experiment, mulching with M. japonicus straw increased the root biomass, stem biomass, leaf biomass, shoot biomass, plant height and activities of antioxidant enzymes (superoxide dismutase, peroxidase and catalase) of G. parviflora compared with the control, whereas mulching with straws of R. sieboldii, C. confine and P. asiatica decreased these parameters. Straws of the four Cd-tolerant plants increased the Cd content in roots of G. parviflora compared with the control. However, only straws of M. japonicus and P. asiatica increased the Cd content in shoots of G. parviflora, reduced the soil pH, and increased the soil exchangeable Cd concentration. Straw of M. japonicus increased the amount of Cd extraction in stems, leaves and shoots of G. parviflora by 21.11%, 29.43% and 24.22%, respectively, compared with the control, whereas straws of the other three Cd-tolerant plants decreased these parameters. In the field experiment, the M. japonicus straw also increased shoot biomass, Cd content in shoots, and amount of Cd extraction in shoots of G. parviflora compared with the control. Therefore, straw of M. japonicus can be used to improve the Cd extraction ability of G. parviflora from Cd-contaminated soil. PMID:25490210

Deciphering adverse effects of heavy metals on diverse wheat germplasm on irrigation with urban wastewater of mixed municipal-industrial origin.

PubMed

Ali, Zeshan; Mujeeb-Kazi, Abdul; Quraishi, Umar Masood; Malik, Riffat Naseem

2018-04-25

The current study provides one of the first attempts to identify tolerant, moderately sensitive, and highly sensitive wheat genotypes on the basis of heavy metal accumulation, biochemical attributes, and human health risk assessments on urban wastewater (UW) irrigation. Mean heavy metals (Fe, Co, Ni, Cu, Zn, Pb, Cd, Cr, Mn) and macro-nutrients (Na, K, Ca, Mg) levels increased in the roots, stem, and grains of studied genotypes. Except K (stem > root > grain), all metals were accumulated in highest concentrations in roots followed by stem and grains. Principal component analyses (PCA) identified three groups of UW-irrigated genotypes which were confirmed by hierarchical agglomerative cluster analyses (HACA). Wheat genotypes with the lowest metal accumulation were regarded as tolerant, whereas those with maximum accumulation were considered highly sensitive. Tolerant genotypes showed the lowest hazard quotient for heavy metals, i.e., Co, Mn, Cd, Cu, Fe, Pb, and Cr, and hazard index (HI) values (adults, 2.04; children, 2.27) than moderately and highly sensitive genotypes. Higher health risks (HI) associated with moderate (adults 2.26; children 2.53) and highly sensitive (adults 2.52; children 2.82) genotypes revealed maximum uptake of heavy metals. The heatmap showed higher mean biochemical levels of chlorophyll, carotenoids, membrane stability index (MSI%), sugars, proteins, proline, superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in tolerant genotypes than remaining genotypes. With the lowest metal accumulation and advanced biochemical mechanisms to cope with the adverse effects of heavy metals in their plant bodies, tolerant genotypes present a better option for cultivation in areas receiving UW or similar type of wastewater.

[Experimental study of glioma stem cell-mediated immune tolerance in tumor microenvironment].

PubMed

Xie, T; Ma, J W; Liu, B; Dong, J; Huang, Q

2017-11-23

Objective: To investigate the tumor microenvironment of immune tolerance induced by glioma stem cells (GSC). Methods: Human GSC SU3 cells transfected with red fluorescent protein (SU3-RFP) gene were implanted into the brain, subcutis (armpit and foot), liver and abdominal cavity of transgenic green fluorescence protein (GFP) nude mice to establish RFP(+) /GFP(+) dual fluorescence solid tumor model. The re-cultured cells derived from implanted tumor tissues, SU3-RFP cells co-cultured with peritoneal fluid of transgenic GFP nude mice and malignant ascites of tumor-bearing mice were observed by fluorescence microscopy and real-time video image tracing to analyze the microenvironment of immune tolerance mediated by RFP(+) /GFP(+) implanted tumor. Results: Dual fluorescence labeled frozen section showed that all of cells in the tumor microenvironment were GFP(+) , while the pressed tissue-patch showed that the tumor blood vessels exhibited a RFP(+) /GFP(+) double-positioning yellow. In the GFP single fluorescence labeled tumor tissue, all of cells in the microenvironment were green, including tumor edge, necrotic foci and blood vessel. Among them, CD68(+) , F4/80(+) , CD11c(+) , CD11b(+) and CD80(+) cells were observed. In the dual fluorescence labeled co-cultured cells, the phagocytosis and fusion between green host cells and red tumor cells were also observed, and these fusion cells might transfer to the malignant dendritic cells and macrophages. Conclusions: The tumor microenvironment of immune tolerance induced by GSC is not affected by the tissue types of tumor-inoculated sites, and the immune tolerance mediated by inflammatory cells is associated with the inducible malignant transformation, which may be driven by cell fusion.

Hematopoietic Stem Cell Injury Induced by Ionizing Radiation

PubMed Central

Shao, Lijian; Luo, Yi

2014-01-01

Abstract Significance: Exposure to ionizing radiation (IR) as the result of nuclear accidents or terrorist attacks is a significant threat and a major medical concern. Hematopoietic stem cell (HSC) injury is the primary cause of death after accidental or intentional exposure to a moderate or high dose of IR. Protecting HSCs from IR should be a primary goal in the development of novel medical countermeasures against radiation. Recent Advances: Significant progress has been made in our understanding of the mechanisms by which IR causes HSC damage. The mechanisms include (i) induction of HSC apoptosis via the p53-Puma pathway; (ii) promotion of HSC differentiation via the activation of the G-CSF/Stat3/BATF-dependent differentiation checkpoint; (iii) induction of HSC senescence via the ROS-p38 pathway; and (iv) damage to the HSC niche. Critical Issues: Induction of apoptosis in HSCs and hematopoietic progenitor cells is primarily responsible for IR-induced acute bone marrow (BM) injury. Long-term BM suppression caused by IR is mainly attributable to the induction of HSC senescence. However, the promotion of HSC differentiation and damage to the HSC niche can contribute to both the acute and long-term effects of IR on the hematopoietic system. Future Directions: In this review, we have summarized a number of recent findings that provide new insights into the mechanisms whereby IR damages HSCs. These findings will provide new opportunities for developing a mechanism-based strategy to prevent and/or mitigate IR-induced BM suppression. Antioxid. Redox Signal. 20, 1447–1462. PMID:24124731

Breaking tolerance in transgenic mice expressing the human TSH receptor A-subunit: thyroiditis, epitope spreading and adjuvant as a 'double edged sword'.

PubMed

McLachlan, Sandra M; Aliesky, Holly A; Chen, Chun-Rong; Chong, Gao; Rapoport, Basil

2012-01-01

Transgenic mice with the human thyrotropin-receptor (TSHR) A-subunit targeted to the thyroid are tolerant of the transgene. In transgenics that express low A-subunit levels (Lo-expressors), regulatory T cell (Treg) depletion using anti-CD25 before immunization with adenovirus encoding the A-subunit (A-sub-Ad) breaks tolerance, inducing extensive thyroid lymphocytic infiltration, thyroid damage and antibody spreading to other thyroid proteins. In contrast, no thyroiditis develops in Hi-expressor transgenics or wild-type mice. Our present goal was to determine if thyroiditis could be induced in Hi-expressor transgenics using a more potent immunization protocol: Treg depletion, priming with Complete Freund's Adjuvant (CFA) + A-subunit protein and further Treg depletions before two boosts with A-sub-Ad. As controls, anti-CD25 treated Hi- and Lo-expressors and wild-type mice were primed with CFA+ mouse thyroglobulin (Tg) or CFA alone before A-sub-Ad boosting. Thyroiditis developed after CFA+A-subunit protein or Tg and A-sub-Ad boosting in Lo-expressor transgenics but Hi- expressors (and wild-type mice) were resistant to thyroiditis induction. Importantly, in Lo-expressors, thyroiditis was associated with the development of antibodies to the mouse TSHR downstream of the A-subunit. Unexpectedly, we observed that the effect of bacterial products on the immune system is a "double-edged sword". On the one hand, priming with CFA (mycobacteria emulsified in oil) plus A-subunit protein broke tolerance to the A-subunit in Hi-expressor transgenics leading to high TSHR antibody levels. On the other hand, prior treatment with CFA in the absence of A-subunit protein inhibited responses to subsequent immunization with A-sub-Ad. Consequently, adjuvant activity arising in vivo after bacterial infections combined with a protein autoantigen can break self-tolerance but in the absence of the autoantigen, adjuvant activity can inhibit the induction of immunity to autoantigens (like the TSHR) displaying strong self-tolerance.

Breaking Tolerance in Transgenic Mice Expressing the Human TSH Receptor A-Subunit: Thyroiditis, Epitope Spreading and Adjuvant as a ‘Double Edged Sword’

PubMed Central

McLachlan, Sandra M.; Aliesky, Holly A.; Chen, Chun-Rong; Chong, Gao; Rapoport, Basil

2012-01-01

Transgenic mice with the human thyrotropin-receptor (TSHR) A-subunit targeted to the thyroid are tolerant of the transgene. In transgenics that express low A-subunit levels (Lo-expressors), regulatory T cell (Treg) depletion using anti-CD25 before immunization with adenovirus encoding the A-subunit (A-sub-Ad) breaks tolerance, inducing extensive thyroid lymphocytic infiltration, thyroid damage and antibody spreading to other thyroid proteins. In contrast, no thyroiditis develops in Hi-expressor transgenics or wild-type mice. Our present goal was to determine if thyroiditis could be induced in Hi-expressor transgenics using a more potent immunization protocol: Treg depletion, priming with Complete Freund's Adjuvant (CFA) + A-subunit protein and further Treg depletions before two boosts with A-sub-Ad. As controls, anti-CD25 treated Hi- and Lo-expressors and wild-type mice were primed with CFA+ mouse thyroglobulin (Tg) or CFA alone before A-sub-Ad boosting. Thyroiditis developed after CFA+A-subunit protein or Tg and A-sub-Ad boosting in Lo-expressor transgenics but Hi- expressors (and wild-type mice) were resistant to thyroiditis induction. Importantly, in Lo-expressors, thyroiditis was associated with the development of antibodies to the mouse TSHR downstream of the A-subunit. Unexpectedly, we observed that the effect of bacterial products on the immune system is a “double-edged sword”. On the one hand, priming with CFA (mycobacteria emulsified in oil) plus A-subunit protein broke tolerance to the A-subunit in Hi-expressor transgenics leading to high TSHR antibody levels. On the other hand, prior treatment with CFA in the absence of A-subunit protein inhibited responses to subsequent immunization with A-sub-Ad. Consequently, adjuvant activity arising in vivo after bacterial infections combined with a protein autoantigen can break self-tolerance but in the absence of the autoantigen, adjuvant activity can inhibit the induction of immunity to autoantigens (like the TSHR) displaying strong self-tolerance. PMID:22970131

Previous Ingestion of Lactococcus lactis by Ethanol-Treated Mice Preserves Antigen Presentation Hierarchy in the Gut and Oral Tolerance Susceptibility.

PubMed

Alvarenga, Débora M; Perez, Denise A; Gomes-Santos, Ana C; Miyoshi, Anderson; Azevedo, Vasco; Coelho-Dos-Reis, Jordana G A; Martins-Filho, Olindo A; Faria, Ana Maria C; Cara, Denise C; Andrade, Marileia C

2015-08-01

Ethanol (EtOH) consumption is able to disturb the ovalbumin (OVA)-oral tolerance induction by interfering on the function of antigen presenting cells (APC), down-regulating dendritic cells (DCs) and macrophages and up-regulating B-lymphocytes and their function, which results in an overall allergic-type immune status. In this study, the potential of a priori administration of Lactococcus lactis (LL) in avoiding loss of oral tolerance in EtOH-treated mice was investigated. Female C57BL/6 mice received, by oral route, ad libitum wild-type (WT) LL or heat-shock protein producer (Hsp65) LL for 4 consecutive days. Seven days later, mice were submitted to short-term high-dose EtOH treatment. After 24 hours, stomach, intestine, spleen, mesenteric lymph nodes (mLN) specimens were collected for biomarkers analysis. Following EtOH-treatment protocol, a group of animals underwent single-gavage OVA-tolerance protocol and sera samples collected for antibody analysis. The ingestion of WT LL or Hsp65 LL is able to restore oral tolerance to OVA in EtOH-treated mice, by reducing local and systemic allergic outcomes such as gastric mast cells and gut-interleukin-4, as well as serum IgE. WT LL treatment prevents the decrease of mLN regulatory T cells induced by the EtOH treatment. Moreover, LL treatment preserves APC hierarchy and antigen presentation commitment in EtOH-treated mice, with conserved DC and macrophage activity over B lymphocytes in mLN and preserved macrophage activity over DC and B-cell subsets in the spleen. The present findings suggest that a priori ingestion of LL preserves essential mechanisms associated with oral tolerance induction that are disturbed by EtOH ingestion. Maintenance of mucosal homeostasis by preserving APC hierarchy and antigen presentation commitment could be associated with T-regulatory subset activities in the gastrointestinal tract. Copyright © 2015 by the Research Society on Alcoholism.

A Retrospective, Multicenter Study of the Tolerance of Induction Chemotherapy With Docetaxel, Cisplatin, and 5-Fluorouracil Followed by Radiotherapy With Concomitant Cetuximab in 46 Cases of Squamous Cell Carcinoma of the Head and Neck

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buiret, Guillaume, E-mail: guillaume.buiret@laposte.ne; Service de biostatistique, Hospices Civils de Lyon, Lyon; Combe, Claire

2010-06-01

Purpose: To investigate, in a multicenter study, the tolerance of induction chemotherapy (ICT) and external radiotherapy (ERT) with concomitant cetuximab in the treatment of patients with squamous cell carcinoma of the head and neck (SCCHN). Patients and Methods: Clinical data from 46 patients with Stage III or IV nonmetastatic SCCHN who received docetaxel, cisplatin, and 5-fluorouracil as ICT, followed by ERT with concomitant cetuximab, were retrospectively analyzed. Clinical safety (weight, allergy, mucositis, and dermatitis) and paraclinical safety (levels of hemoglobin, polynuclear neutrophils, and creatinine clearance) were studied. The primary objective was the proportion of patients who completed the protocol. Results:more » The percentage of patients completing ICT was 73.9%, ERT 93.5%, and cetuximab 69.6%. Induction chemotherapy was better tolerated than that previously reported. The rates of temporary suspensions of radiation (39.1%, mean duration of 13 days) and hospitalization (26.1%) during ERT with concomitant cetuximab were high. Weight loss during treatment (21.4% of patients lost >10% of their body weight), radiodermatitis, and radiomucositis were the main causes of temporary suspension of treatment, although Grade 4 dermatitis was not experienced. There were no allergic reactions to cetuximab. Conclusion: The completed protocol rate for SCCHN patients receiving ICT and ERT with concomitant cetuximab is high and the toxicity acceptable. Future improvements to protocol will be possible through early action and systematic implementation of nutritional support coupled with antibiotic treatment upon the first signs of radiodermatitis. These data could be useful for prospective studies on the safety and efficacy of this protocol.« less

Evaluating Study Withdrawal Among Biologics and Immunomodulators in Treating Ulcerative Colitis: A Meta-analysis of Controlled Clinical Trials.

PubMed

Shah, Eric D; Siegel, Corey A; Chong, Kelly; Melmed, Gil Y

2016-04-01

We conducted a systematic review and meta-analysis to evaluate the efficacy and adverse event (AE)-associated tolerability of treatment with immunomodulators and biologics in ulcerative colitis clinical trials. We performed a literature search of PubMed and the Cochrane databases to identify randomized placebo-controlled trials of immunomodulators and biologics. Tolerability was defined through study withdrawal due to AEs and efficacy through clinical response in induction trials and clinical remission in maintenance trials. We performed meta-analyses using a random-effects model to determine relative risks (RRs) of efficacy and study withdrawal. Number needed to treat (NNT) and number needed to stop (NNS) were determined. The ratio of NNS/NNT was calculated, with a higher ratio indicating a greater number of patients in remission for every AE study discontinuation. We examined 13 single-agent trials representing biologics (infliximab, adalimumab, golimumab, and vedolizumab) and immunomodulators (tacrolimus and azathioprine). Induction therapy did not result in excess study withdrawal with immunomodulators (RR = 0.9, 95% CI 0.1-12.0) or biologics (RR = 0.7, 95% CI 0.3-1.8), therefore the NNS/NNT ratio could not be assessed because of high tolerability. Maintenance immunomodulator therapy resulted in a NNS of 14 (RR = 2.8, 95% CI 0.7-10.5) and NNS/NNT ratio of 2.4 in 2 trials. Biologics did not result in excess study withdrawal in maintenance (RR = 0.7, 95% CI 0.3-1.7) or combined induction-and-maintenance (RR = 0.6, 95% CI 0.4-1.0) trials. Biologics were not associated with a higher RR of study withdrawal due to AE than placebo. There were insufficient data to compare these results with immunomodulators.

Protective Cellular Immunity Against Influenza Virus Induced by Plasmid Inoculation of Newborn Mice

PubMed Central

Bot, Adrian; Bot, Simona; García-Sastre, Adolfo

1998-01-01

Neonate organisms display an intrinsic disability to mount effective immune responses to infectious agents or conventional vaccines. Whereas low. doses of antigens trigger a suboptimal response, higher doses are frequently associated with tolerance induction. We investigated the ability of a plasmid-expressing nucleoprotein of influenza virus to prime a specific cellular immune response when administered to newborn mice. We found that persistent exposure to antigen following plasmid inoculation of neonates leads to a vigorous priming of specific CTLs rather than tolerance induction. The CTLs were cross-reactive against multiple strains of type A influenza viruses and produced IFNγ but no IL-4. The immunity triggered by plasmid inoculation of neonates was protective in terms of pulmonary virus clearance as well as survival rate following lethal challenge with influenza virus. Whereas the persistence of the plasmid at the site of injection was readily demonstrable in adult mice at 3 months after inoculation, mice immunized as newborns displayed no plasmid at 3 months and very little at 1 month after injection. Thus, DNA-based immunization of neonates may prove an effective and safe vaccination strategy for induction of cellular immunity against microbes that cause serious infectious diseases in the early period of life. PMID:9851359

Effect of stem water content on sap flow from dormant maple and butternut stems: induction of sap flow in butternut.

PubMed

Johnson, R W; Tyree, M T

1992-10-01

Sap flow from excised maple stems collected over the winter (1986/87) was correlated with stem water content. Stem water content was high in the fall (>0.80) and decreased rapidly during 2 weeks of continuous freezing temperatures in late winter (<0.60). Exudation of sap from stem segments subjected to freeze/thaw cycles was small (<10 mL/kg) in the fall, but substantial exudation (45-50 mL/kg) occurred following the decline in water content. These observations are consistent with Milburn's and O'Malley's models (J.A. Milburn, P.E.R. O'Malley [1984] Can J Bot 62: 2101-2106; P.E.R. O'Malley, J.A. Milburn [1983] Can J Bot 61:3100-3106) of sap absorption into gas-filled fibers during freezing. Exudation volume was increased 200 to 300% in maple stems originally at high water content (>0.80) after perfusion with sucrose and dehydration at -12 degrees C. Sap flow was also induced in butternut stem segments after the same treatment. Thus, sap flow may not be unique to maples. Sap flow could not be increased in stem segments dehydrated at 4 degrees C. Migration of water molecules from small ice crystals in fibers to larger crystals in vessels while stems were frozen may account for increase exudation after dehydration at -12 degrees C. This would result in preferential dehydration of fibers and a distribution of gas and sap favorable for stem-based sap flow.

The Effect of Recombinant Tyrosine Hydroxylase Expression on the Neurogenic Differentiation Potency of Mesenchymal Stem Cells

PubMed Central

Duruksu, Gokhan; Karaoz, Erdal

2018-01-01

Objective Tyrosine hydroxylase (TH) is a rate-limiting enzyme in dopamine synthesis, making the enhancement of its activity a target for ensuring sufficient dopamine levels. Rat bone marrow mesenchymal stem cells (rBM-MSCs) are known to synthesize TH after differentiating into neuronal cells through chemical induction, but the effect of its ectopic expression on these cells has not yet been determined. This study investigated the effects of ectopic recombinant TH expression on the stemness characteristics of rBM-MSCs. Methods After cloning, a cell line with stable TH expression was maintained, and the proliferation, the gene expression profile, and differentiation potential of rBM-MSCs were analyzed. Analysis of the cells showed an increment in the proliferation rate that could be reversed by the neutralization of TH. Results The constitutive expression of TH in rBM-MSCs was successfully implemented, without significantly affecting their osteogenic and adipogenic differentiation potential. TH expression improved the expression of other neuronal markers, such as glial fibrillary acidic protein, β-tubulin, nestin, and c-Fos, confirming the neurogenic differentiation capacity of the stem cells. The expression of brain-derived neurotrophic factor (BDNF) and ciliary neurotrophic factor (CNTF) significantly increased after the chemical induction of neurogenic differentiation. Conclusion In this study, the expression of recombinant TH improved the neuroprotective effect of MSCs by upregulating the expression of BDNF and CNTF. Although the neuronal markers were upregulated, the expression of recombinant TH alone in rBM-MSCs was not sufficient for MSCs to differentiate into neurogenic cell lines. PMID:29656620