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Sample records for parabiosis

  1. Reanalysis of parabiosis of obesity mutants in the age of leptin.

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    Zeng, Wenwen; Lu, Yi-Hsueh; Lee, Jonah; Friedman, Jeffrey M

    2015-07-21

    In this study we set out to explain the differing effects of parabiosis with genetically diabetic (db) mice versus administration of recombinant leptin. Parabiosis of db mutant, which overexpress leptin, to wildtype (WT) or genetically obese (ob) mice has been reported to cause death by starvation, whereas leptin infusions do not produce lethality at any dose or mode of delivery tested. Leptin is not posttranslationally modified other than a single disulphide bond, raising the possibility that it might require additional factor(s) to exert the maximal appetite-suppressing effect. We reconfirmed the lethal effect of parabiosis of db mutant on WT mice and further showed that this lethality could not be rescued by administration of ghrelin or growth hormone. We then initiated a biochemical fractionation of a high-molecular-weight leptin complex from human plasma and identified clusterin as a major component of this leptin-containing complex. However, in contrast to previous reports, we failed to observe a leptin-potentiating effect of either exogenous or endogenous clusterin, and parabiosis of db clusterin(-/-) double-mutant to WT mice still caused lethality. Intriguingly, in parabiotic pairs of two WT mice, leptin infusion into one of the mice led to an enhanced starvation response during calorie restriction as evidenced by increased plasma ghrelin and growth-hormone levels. Moreover, leptin treatment resulted in death of the parabiotic pairs. These data suggest that the appetite suppression in WT mice after parabiosis to db mutants is the result of induced hyperleptinemia combined with the stress or other aspect(s) of the parabiosis procedure.

  2. HOY COMO AYER. PARABIOSIS Y SU COMBINACIÓN CON OTRAS TÉCNICAS PARA DESCUBRIR LOS SECRETOS DE LA SANGRE

    Directory of Open Access Journals (Sweden)

    Alfredo Jesús López Dávila

    2014-02-01

    Full Text Available López-Dávila, A. J. (2014. Hoy como ayer. Parabiosis y su combinación con otras técnicas para descubrir los secretos de la sangre. Pensar en Movimiento: Revista de Ciencias del Ejercicio y la Salud, 12 (1, 1-15. Este artículo repasa algunos descubrimientos importantes relacionados con la fisiología del ejercicio, los cuales han sido posibles gracias al modelo llamado parabiosis. La parabiosis es una preparación fisiológica experimental en la cual dos animales comparten una sola circulación sanguínea. Este método permite demostrar la existencia de factores circulantes en la sangre y el efecto que estos tienen sobre diferentes tejidos. Aunque esta técnica se ha practicado por más de 150 años, sigue siendo muy utilizada y sus alcances se han reforzado gracias al uso de los métodos modernos de la biología molecular como herramienta complementaria. Por medio de experimentos de parabiosis se ha demostrado que en la sangre de modelos animales circulan moléculas capaces –entre otras acciones- de: a regular la masa grasa corporal por medio de retrocontrol negativo, b reducir la hipertrofia cardiaca asociada a la disfunción diastólica que ocurre con el envejecimiento c inhibir la neurogénesis en el giro dentado del hipocampo y causar disfunciones cognitivas, d favorecer la remielinización de la médula espinal y e activar o inhibir la regeneración del músculo esquelético que se da luego de una lesión. El constante descubrimiento de factores que circulan en la sangre y sus efectos en diversos órganos abren nuevas preguntas acerca de los mecanismos moleculares y celulares que explican estos fenómenos y su posible aplicación en la salud del ser humano. La fisiología del ejercicio es una herramienta valiosa para hallar las respuestas.

  3. Accelerated aging versus rejuvenation of the immune system in heterochronic parabiosis.

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    Pishel, Iryna; Shytikov, Dmytro; Orlova, Tatiana; Peregudov, Alex; Artyuhov, Igor; Butenko, Gennadij

    2012-04-01

    The emergence of immune disorders in aging is explained by many factors, including thymus dysfunction, decrease in the proportion and function of naïve T cells, and so forth. There are several approaches to preventing these changes, such as thymus rejuvenation, stem cells recovery, modulation of hormone production, and others. Our investigations of heterochronic parabiosis have shown that benefits of a young immune system, e.g., actively working thymus and regular migration of young hematopoietic stem cells between parabiotic partners, appeared unable to restore the immune system of the old partner. At the same time, we have established a progressive immune impairment in the young heterochronic partners. The mechanism of age changes in the immune system in this model, which may lead to reduced life expectancy, has not been fully understood. The first age-related manifestation in the young partners observed 3 weeks after the surgery was a dramatic increase of CD8(+)44(+) cells population in the spleen. A detailed analysis of further changes revealed a progressive decline of most immunological functions observable for up to 3 months after the surgery. This article reviews possible mechanisms of induction of age-related changes in the immune system of young heterochronic partners. The data obtained suggest the existence of certain factors in the old organisms that trigger aging, thus preventing the rejuvenation process.

  4. Systemic Problems: A perspective on stem cell aging and rejuvenation.

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    Conboy, Irina M; Conboy, Michael J; Rebo, Justin

    2015-10-01

    This review provides balanced analysis of the advances in systemic regulation of young and old tissue stem cells and suggests strategies for accelerating development of therapies to broadly combat age-related tissue degenerative pathologies. Many highlighted recent reports on systemic tissue rejuvenation combine parabiosis with a "silver bullet" putatively responsible for the positive effects. Attempts to unify these papers reflect the excitement about this experimental approach and add value in reproducing previous work. At the same time, defined molecular approaches, which are "beyond parabiosis" for the rejuvenation of multiple old organs represent progress toward attenuating or even reversing human tissue aging.

  5. Incidences of types of cancer in irradiated parabiont rats

    International Nuclear Information System (INIS)

    Warren, S.; Chute, R.N.; Brown, C.E.; Gates, O.

    1982-01-01

    A total body dose of 1000 R X radiation to 1252 male and 1366 female NEDH rats protected by permanent parabiosis to an untreated partner yielded respective cancer incidences of 42.7 and 38.3% within mean life-spans slightly less than single controls. These incidences were significant at the 1% level of probability compared with lower rates in shielded partners as well as in over 600 control parabiont partners and 700 single controls in which both sexes were nearly equally represented. Significant cancer incidences were induced in skin and islet cells of males, soft supporting tissue, renal tubules, bone of males and females, and ovary. Parabiosis per se provided local conditions conducive to the development of sarcomas, possibly enhanced by radiation, in anastomosed tissue as well as systemic changes promoting the spontaneous development of lymphoma and leukemia in females and inhibiting that of mammary carcinoma in females and malignant pheochromocytoma in males. The effects in females were largely canceled by radiation. The function of dose and its modification by factors contingent to parabiosis are discussed in relation to reported data on rats of other strains exposed to sublethal or lethal total-body X-ray doses

  6. Young Blood Rejuvenates Old Bodies: A Call for Reflection when Moving from Mice to Men.

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    Hofmann, Bjørn

    2018-01-01

    Connecting the circulatory system of old and young mice (parabiosis) is documented to have rejuvenating effects on cells, tissues, organs, and functions. A wide range of benefits are envisioned. Blood-based rejuvenation can come to totally change population health and aging. The first blood rejuvenation studies on humans with Alzheimer's disease have started. It puts blood at the center of therapy and revitalizes the historical line of humoral pathology from Hippocrates and Harvey, creating a new type of 'bloodletting.' However, moving from mice to men requires careful consideration. Parabiosis actualizes well-known ethical challenges, such as just distribution of health care, avoiding disparities, and providing equal access to health care resources, as well as issues of human enhancement. However, it also poses new problems. Using internal substances in some persons as means to rejuvenate others calls for ethical reflection. New type of 'blood bonds' may result from the continuous demand for specific types of blood. Even if rejuvenating substances from blood may be artificially and cheaply produced and justly distributed, problems arise: survival may have to be balanced against reproduction, as reproductive age increases. Eternal youth and endless bliss have always been vital human dreams. Although parabiosis may bring us closer to the fountain of youth than ever, it is still too early to provide full-fledged assessments of its implications or to foresee how it will change health, aging, medicine, and society. However, in order to bring our reflective abilities on par with our technical skills, we need to start reflection now.

  7. Hemopoiesis recovery of irradiated rats conjugated with normo- and poly- cythemic animal by aortic anastomoses

    International Nuclear Information System (INIS)

    Baba, Yuji

    1980-01-01

    The experiment was designed to observe the possible relation between myelopoietic and erythropoietic activities of circulating nucleated cells. Wistar rats were lethally irradiated with 60 Co, 1000 r once. Two days after irradiation the bone marrow cells had faded completely. At this stage animals were conjugated with normocythemic or polycythemic rats by aortic anastomoses. After conjugation the aplastic bone marrow of the irradiated animal rapidly regained its hemopoietic activity in cases having normocythemic and polycythemic partners. Active erythropoiesis and myelopoiesis were found 96 h after parabiosis in those having normocythemic partners. In animals having polycythemic partners, however, erythropoiesis was successfully suppressed. An increase in lymphoid cell numbers was found in place of decreased erythroid cells, but there was no change in the myeloid cell proliferation rate. No hemopoietic precursor cells or immature cells were found in circulating blood all through the experimental period before and after parabiosis. The data suggest that circulating nucleated cells have marked erythropoietic activity. Erythropoietic cells may be somehow related to lymphoid cells independent of myelopoietic activity. (author)

  8. Homeostatic migration and distribution of innate immune cells in primary and secondary lymphoid organs with ageing.

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    Nikolich-Žugich, J; Davies, J S

    2017-03-01

    Ageing of the innate and adaptive immune system, collectively termed immune senescence, is a complex process. One method to understand the components of ageing involves dissociating the effects of ageing on the cells of the immune system, on the microenvironment in lymphoid organs and tissues where immune cells reside and on the circulating factors that interact with both immune cells and their microenvironment. Heterochronic parabiosis, a surgical union of two organisms of disparate ages, is ideal for this type of study, as it has the power to dissociate the age of the cell and the age of the microenvironment into which the cell resides or is migrating. So far, however, it has been used sparingly to study immune ageing. Here we review the limited literature on homeostatic innate immune cell trafficking in ageing in the absence of chronic inflammation. We also review our own recent data on trafficking of innate immune subsets between primary and secondary lymphoid organs in heterochronic parabiosis. We found no systemic bias in retention or acceptance of neutrophils, macrophages, dendritic cells or natural killer cells with ageing in primary and secondary lymphoid organs. We conclude that these four innate immune cell types migrate to and populate lymphoid organs (peripheral lymph nodes, spleen and bone marrow), regardless of their own age and of the age of lymphoid organs. © 2017 British Society for Immunology.

  9. Irradiation inhibits the regeneration of aneurogenic limbs

    International Nuclear Information System (INIS)

    Wallace, H.; Maden, M.

    1976-01-01

    The developing arms of axolotl larvae from the 2-digit stage onward and the aneurogenic arms of surgically denervated larvae maintained in parabiosis are able to regenerate after amputation. Such regeneration is uniformly inhibited by local irradiation of the arm, whether innervated or not. This demonstration refutes a recent hypothesis that x-rays interfere with a special activity of nerves required for regeneration, and supports the earlier concept that x-rays act directly on those cells which must proliferate to form the regenerated tissues

  10. The majority of lymphocytes in the bone marrow. Thymus and extrathymic T cells in the liver are generated in situ from their own preexisting precursors

    International Nuclear Information System (INIS)

    Shimizu, Takao; Sugahara, Satoshi; Oya, Hiroshi; Maruyama, Satoshi; Minagawa, Masahiro; Bannai, Makoto; Hatakeyama, Katsuyoshi; Abo, Toru

    1999-01-01

    Parabiotic pairs of B6.Ly5.1 and B6.Ly5.2 mice were used to investigate how lymphocytes in various organs and various lymphocyte subsets mixed with partner cells. The origin of partner cells was determined by using anti-Ly5.1 mAb in conjunction with immunofluorescence tests. Parabiosis was also produced after the irradiation of B6.Ly5.2 mice at various doses to prepare an immunosuppressive partner. Irrespective of irradiation, lymphocytes and other hematopoietic cells in the bone marrow and lymphocytes in the thymus showed a low mixture of partner cells in comparison with those of all other organs tested. On the other hand, lymphocytes in the blood, spleen, and lymph nodes became a half-and-half mixture of their own cells and partner cell by 14 days after parabiosis. Among lymphocyte subsets, intermediate CD3 cells (i.e., CD3 int cells) and NKT cells (i.e., NK1.1 + subset of CD3 int cells) in the liver also showed a low mixture of partner cells. The present results raise the possibility that lymphocytes in the bone marrow and thymus, and extrathymic T cells in the liver might be in situ generated from their own preexisting precursor cells. Another observation was that, after irradiation, partner cells showed accelerated mixture even if they showed a low mixture under non-irradiated conditions. However, only lymphocyte subsets with the same phenotype as those of preexisting cells entered the corresponding sites. (author)

  11. Role of marrow architecture and stromal cells in the recovery process of aplastic marrow of lethally irradiated rats parabiosed with healthy litter mates

    International Nuclear Information System (INIS)

    Hayashi, K.; Kagawa, K.; Awai, M.; Irino, S.

    1986-01-01

    Bone marrow aplasia was induced in rats by whole body lethal irradiation (1,000 rads by x-ray), and rats died of irradiation injury within 7 days. Correlative studies at light (LM), transmission (TEM) and scanning electron microscopy (SEM) demonstrated swelling of endothelial and reticular cells and hemorrhage due to detachment of sinus endothelial cells on days 1 and 2. With time, structural recovery occurred without hemopoietic recovery. Reticular cells developed small intracytoplasmic lipid droplets on days 3 and 4. This resulted in fatty aplastic marrow within 7 days. On the other hand, in the marrow of irradiated rats parabiosed with healthy mates by aortic anastomosis, hemopoiesis was initiated by adhesion of nucleated blood cells to fine cytoplasmic pseudopods of fat-stored cells on days 1 and 2 after parabiosis. On days 3 to 5, reticular cells with large lipid droplets and fine pseudopods increased, then hemopoietic foci became clear and extensive. On day 8 after parabiosis, the aplastic bone marrow recovered completely both its structure and hemopoietic activity. Thus, hemopoietic recovery in lethally irradiated marrow begins with recovery of vascular endothelial cells, re-establishment of sinusoidal structure, and morphological and functional recoveries of reticular cells from fat-storage cells by releasing intracytoplasmic lipid droplets. Marrow stromal cells, namely reticular, fat-storage and fibroblastoid cells, share a common cellular origin, and regain their structure and function when fat-storage cells and fibroid cells are placed in contact with hemopoietic precursor cells

  12. Therapeutic potential of systemic brain rejuvenation strategies for neurodegenerative disease [version 1; referees: 3 approved

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    Alana M. Horowitz

    2017-08-01

    Full Text Available Neurodegenerative diseases are a devastating group of conditions that cause progressive loss of neuronal integrity, affecting cognitive and motor functioning in an ever-increasing number of older individuals. Attempts to slow neurodegenerative disease advancement have met with little success in the clinic; however, a new therapeutic approach may stem from classic interventions, such as caloric restriction, exercise, and parabiosis. For decades, researchers have reported that these systemic-level manipulations can promote major functional changes that extend organismal lifespan and healthspan. Only recently, however, have the functional effects of these interventions on the brain begun to be appreciated at a molecular and cellular level. The potential to counteract the effects of aging in the brain, in effect rejuvenating the aged brain, could offer broad therapeutic potential to combat dementia-related neurodegenerative disease in the elderly. In particular, results from heterochronic parabiosis and young plasma administration studies indicate that pro-aging and rejuvenating factors exist in the circulation that can independently promote or reverse age-related phenotypes. The recent demonstration that human umbilical cord blood similarly functions to rejuvenate the aged brain further advances this work to clinical translation. In this review, we focus on these blood-based rejuvenation strategies and their capacity to delay age-related molecular and functional decline in the aging brain. We discuss new findings that extend the beneficial effects of young blood to neurodegenerative disease models. Lastly, we explore the translational potential of blood-based interventions, highlighting current clinical trials aimed at addressing therapeutic applications for the treatment of dementia-related neurodegenerative disease in humans.

  13. The majority of lymphocytes in the bone marrow. Thymus and extrathymic T cells in the liver are generated in situ from their own preexisting precursors

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    Shimizu, Takao; Sugahara, Satoshi; Oya, Hiroshi; Maruyama, Satoshi; Minagawa, Masahiro; Bannai, Makoto; Hatakeyama, Katsuyoshi; Abo, Toru [Niigata Univ. (Japan). School of Medicine

    1999-06-01

    Parabiotic pairs of B6.Ly5.1 and B6.Ly5.2 mice were used to investigate how lymphocytes in various organs and various lymphocyte subsets mixed with partner cells. The origin of partner cells was determined by using anti-Ly5.1 mAb in conjunction with immunofluorescence tests. Parabiosis was also produced after the irradiation of B6.Ly5.2 mice at various doses to prepare an immunosuppressive partner. Irrespective of irradiation, lymphocytes and other hematopoietic cells in the bone marrow and lymphocytes in the thymus showed a low mixture of partner cells in comparison with those of all other organs tested. On the other hand, lymphocytes in the blood, spleen, and lymph nodes became a half-and-half mixture of their own cells and partner cell by 14 days after parabiosis. Among lymphocyte subsets, intermediate CD3 cells (i.e., CD3{sup int} cells) and NKT cells (i.e., NK1.1{sup +} subset of CD3{sup int} cells) in the liver also showed a low mixture of partner cells. The present results raise the possibility that lymphocytes in the bone marrow and thymus, and extrathymic T cells in the liver might be in situ generated from their own preexisting precursor cells. Another observation was that, after irradiation, partner cells showed accelerated mixture even if they showed a low mixture under non-irradiated conditions. However, only lymphocyte subsets with the same phenotype as those of preexisting cells entered the corresponding sites. (author)

  14. Turnover of circulating hematopoietic stem cells

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    Dorie, M J; Maloney, M A; Patt, H M

    1979-10-01

    Short-term parabiosis of male and female CBA/CaJ mice was used to investigate the turnover of circulating hematopoietic stem cells. The change and subsequent disappearance of donor stem cells were monitored by spleen colony assay and chromosome analysis of individual colonies. The results revealed an exponential disappearance of pluripotent stem cells from blood with a characteristic half time of 1.7 h. Blood-borne stem cells were shown to be equilibrated with a subpopulation of marrow stem cells exhibiting a disappearance half time of 9.5 h. Splenectomy did not change the apparent rate of stem cell removal from the blood.

  15. The Acid-Secreting Parietal Cell as an Endocrine Source of Sonic Hedgehog During Gastric Repair

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    Engevik, Amy C.; Feng, Rui; Yang, Li

    2013-01-01

    Sonic Hedgehog (Shh) has been shown to regulate wound healing in various tissues. Despite its known function in tissue regeneration, the role of Shh secreted from the gastric epithelium during tissue repair in the stomach remains unknown. Here we tested the hypothesis that Shh secreted from the acid-secreting parietal cell is a fundamental circulating factor that drives gastric repair. A mouse model expressing a parietal cell-specific deletion of Shh (PC-ShhKO) was generated using animals bearing loxP sites flanking exon 2 of the Shh gene (Shhflx/flx) and mice expressing a Cre transgene under the control of the H+,K+-ATPase β-subunit promoter. Shhflx/flx, the H+,K+-ATPase β-subunit promoter, and C57BL/6 mice served as controls. Ulcers were induced via acetic acid injury. At 1, 2, 3, 4, 5, and 7 days after the ulcer induction, gastric tissue and blood samples were collected. Parabiosis experiments were used to establish the effect of circulating Shh on ulcer repair. Control mice exhibited an increased expression of Shh in the gastric tissue and plasma that correlated with the repair of injury within 7 days after surgery. PC-ShhKO mice showed a loss of ulcer repair and reduced Shh tissue and plasma concentrations. In a parabiosis experiment whereby a control mouse was paired with a PC-ShhKO littermate and both animals subjected to gastric injury, a significant increase in the circulating Shh was measured in both parabionts. Elevated circulating Shh concentrations correlated with the repair of gastric ulcers in the PC-ShhKO parabionts. Therefore, the acid-secreting parietal cell within the stomach acts as an endocrine source of Shh during repair. PMID:24092639

  16. Local fibroblast proliferation but not influx is responsible for synovial hyperplasia in a murine model of rheumatoid arthritis

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    Matsuo, Yusuke; Mizoguchi, Fumitaka; Saito, Tetsuya [Department of Rheumatology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519 (Japan); Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST) Program, Sanbancho, Chiyoda-ku, Tokyo, 102-0075 (Japan); Kawahata, Kimito [Department of Rheumatology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519 (Japan); Ueha, Satoshi; Matsushima, Kouji [Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST) Program, Sanbancho, Chiyoda-ku, Tokyo, 102-0075 (Japan); Department of Molecular Preventive Medicine, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 (Japan); Inagaki, Yutaka [Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST) Program, Sanbancho, Chiyoda-ku, Tokyo, 102-0075 (Japan); Center for Matrix Biology and Medicine, Graduate School of Medicine and the Institute of Medical Sciences, Tokai University, 143 Shimo-kasuya, Isehara, Kanagawa, 259-1193 (Japan); Miyasaka, Nobuyuki [Department of Rheumatology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519 (Japan); Kohsaka, Hitoshi, E-mail: kohsaka.rheu@tmd.ac.jp [Department of Rheumatology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519 (Japan); Japan Science and Technology Agency (JST), Core Research for Evolutional Science and Technology (CREST) Program, Sanbancho, Chiyoda-ku, Tokyo, 102-0075 (Japan)

    2016-02-12

    Synovial fibroblasts play crucial roles in inflammation and joint destruction in rheumatoid arthritis (RA). How they accumulate in the RA joints remains unclear. This study was conducted to discern whether cellular influx from the outside of the joints and local proliferation are responsible for synovial fibroblast accumulation in an animal model of RA. We found that synovial fibroblasts were identified as GFP+ cells using collagen type I alpha 2 (Col1a2)-GFP transgenic reporter mice. Then, bone marrow transplantation and parabiosis techniques were utilized to study the cellular influx. Irradiated wild-type mice were transplanted with bone marrow from Col1a2-GFP mice. Col1a2-GFP and wild-type mice were conjoined for parabiosis. The transplanted mice and the parabionts were subjected to collagen antibody-induced arthritis (CAIA). We found no GFP+ cells in the hyperplastic synovial tissues from the transplanted mice with CAIA and from the wild-type parabionts with CAIA. Furthermore, normal and CAIA synovial tissues from Col1a2-GFP mice and from fluorescent ubiquitination-based cell cycle indicator (Fucci) transgenic mice, in which cells in S/G{sub 2}/M phases of the cell cycle express Azami-Green, were studied for Ki67, a cellular proliferation marker, and vimentin, a fibroblast marker, expression. The percentages of Ki67+/GFP+ and Azami-Green+/vimentin+ cells in the CAIA synovial tissues were higher than those in the untreated synovial tissues (34% vs. 0.40% and 19% vs. 0.26%, respectively). These findings indicate that local fibroblast proliferation but not cellular influx is responsible for the synovial hyperplasia in CAIA. Suppression of proliferation of the local synovial fibroblasts should be a promising treatment for RA. - Highlights: • We studied how synovial fibroblasts accumulate in joints in a murine model of RA. • Bone marrow-derived cells did not accumulate in arthritic joints. • Synovial fibroblasts did not accumulate in arthritic joints via

  17. Liver-derived systemic factors drive β-cell hyperplasia in insulin resistant states

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    El Ouaamari, Abdelfattah; Kawamori, Dan; Dirice, Ercument; Liew, Chong Wee; Shadrach, Jennifer L.; Hu, Jiang; Katsuta, Hitoshi; Hollister-Lock, Jennifer; Qian, Weijun; Wagers, Amy J.; Kulkarni, Rohit N.

    2013-02-21

    Integrative organ cross-talk regulates key aspects of energy homeostasis and its dysregulation may underlie metabolic disorders such as obesity and diabetes. To test the hypothesis that cross-talk between the liver and pancreatic islets modulates β-cell growth in response to insulin resistance, we used the Liver-specific Insulin Receptor Knockout (LIRKO) mouse, a unique model that exhibits dramatic islet hyperplasia. Using complementary in vivo parabiosis and transplantation assays, and in vitro islet culture approaches, we demonstrate that humoral, non-neural, non-cell autonomous factor(s) induce β-cell proliferation in LIRKO mice. Furthermore, we report that a hepatocyte-derived factor(s) stimulates mouse and human β-cell proliferation in ex vivo assays, independent of ambient glucose and insulin levels. These data implicate the liver as a critical source of β-cell growth factors in insulin resistant states.

  18. TRANSFORMAÇÕES DO CORPO: Era parabiose

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    Keline da Costa Brito

    2016-07-01

    Full Text Available O presente trabalho tem como objetivo analisar as transformações que o corpo vem sofrendo decorrente da visão mecanicista que se tem dele, alterando, além de sua dimensão biológica, a subjetividade do indivíduo e suas relações com o meio, resultante da adaptação das biotecnologias ao corpo. Partiremos da abordagem Heideggeriana de preocupar-nos diante do uso tecnológico sobre o próprio indivíduo, e simultaneamente usaremos as análises foucaultiana sobre a rentabilidade do corpo político. Isso fez com que se incida sobre ele um discurso normativo como o tipo de alimento, os exercícios, além do uso de medicamentos e próteses para ampliar o poder dos corpos. Concomitantemente usa-se a engenharia genética possibilitando alternativas de um corpo aperfeiçoado pelo uso de artefatos biotecnológicos que almejam estender a forma natural humana, ou seja, uma parabiose. O Biopoder se realiza cotidianamente, e atua de várias formas através dos mecanismos de poder, estes potencializaram o controle da vida, sem que para isso use força física para impor seu controle. O que pode ser fantástico para a evolução humana, também pode tornar-se algo sem precedente. Portanto, o corpo se tornou um empreendimento a ser administrado, no qual, sem percebermos, vai sendo transformado e “aperfeiçoado”, resultando em uma quimera para a filosofia. Palavras-chave: Corpo; Subjetividade; Controle; Biotecnologia. BODY TRANSFORMATION: Period parabiosis ABSTRACT This paper aims to analyze the changes that the body has suffered due to the mechanistic view that has him changing, and its biological dimension, the subjectivity of the individual and their relationship with the environment, resulting from the adaptation of biotechnology to body. We start from the Heideggerian approach to concern ourselves on the technological use of the individual, and at the same time we will use the Foucault's analysis of the profitability of the body politic. This

  19. Opportunities for systematic change in the academic research library: elements of the post-digital library

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    James G Neal

    2012-03-01

    Full Text Available This paper, based on a talk delivered at the University of Leeds on 19 April 2011, seeks to outline a series of important trends that are influencing the roles and responsibilities of the academic research library, and a program of radical collaboration that would enable deeper integration of resources and a more systemic approach to the critical collection and service challenges. The academic research library must sustain its core responsibilities, albeit in an increasingly digitized, networked and mobile condition, enrich fundamental relationships with its user communities, and assume powerful new roles in support of learning and scholarship. New measures of quality, impact, productivity, innovation and leadership must be advanced. The paper suggests that the evolution of the academic library will focus more on an evolving period of polygamy, parabiosis and particularism, as we think beyond the transition to electronic and more about a post-digital context.

  20. Bone marrow-derived cells in the population of spinal microglia after peripheral nerve injury

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    Tashima, Ryoichi; Mikuriya, Satsuki; Tomiyama, Daisuke; Shiratori-Hayashi, Miho; Yamashita, Tomohiro; Kohro, Yuta; Tozaki-Saitoh, Hidetoshi; Inoue, Kazuhide; Tsuda, Makoto

    2016-01-01

    Accumulating evidence indicates that peripheral nerve injury (PNI) activates spinal microglia that are necessary for neuropathic pain. Recent studies using bone marrow (BM) chimeric mice have reported that after PNI, circulating BM-derived cells infiltrate into the spinal cord and differentiate into microglia-like cells. This raises the possibility that the population of spinal microglia after PNI may be heterogeneous. However, the infiltration of BM cells in the spinal cord remains controversial because of experimental adverse effects of strong irradiation used for generating BM chimeric mice. In this study, we evaluated the PNI-induced spinal infiltration of BM-derived cells not only by irradiation-induced myeloablation with various conditioning regimens, but also by parabiosis and mice with genetically labelled microglia, models without irradiation and BM transplantation. Results obtained from these independent approaches provide compelling evidence indicating little contribution of circulating BM-derived cells to the population of spinal microglia after PNI. PMID:27005516

  1. Tet2 Rescues Age-Related Regenerative Decline and Enhances Cognitive Function in the Adult Mouse Brain

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    Geraldine Gontier

    2018-02-01

    Full Text Available Restoring adult stem cell function provides an exciting approach for rejuvenating the aging brain. However, molecular mechanisms mediating neurogenic rejuvenation remain elusive. Here we report that the enzyme ten eleven translocation methylcytosine dioxygenase 2 (Tet2, which catalyzes the production of 5-hydroxymethylcytosine (5hmC, rescues age-related decline in adult neurogenesis and enhances cognition in mice. We detected a decrease in Tet2 expression and 5hmC levels in the aged hippocampus associated with adult neurogenesis. Mimicking an aged condition in young adults by abrogating Tet2 expression within the hippocampal neurogenic niche, or adult neural stem cells, decreased neurogenesis and impaired learning and memory. In a heterochronic parabiosis rejuvenation model, hippocampal Tet2 expression was restored. Overexpressing Tet2 in the hippocampal neurogenic niche of mature adults increased 5hmC associated with neurogenic processes, offset the precipitous age-related decline in neurogenesis, and enhanced learning and memory. Our data identify Tet2 as a key molecular mediator of neurogenic rejuvenation.

  2. Participation of bone marrow stromal cells in hemopoietic recovery of rats irradiated and then parabiosed with a non-irradiated litter mate, 2. Scanning and transmission electron microscopic observations

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    Kagawa, Koichi; Hayashi, Keiki; Awai, Michiyasu

    1986-07-01

    A light microscopical study on the recovery process after lethal irradiation and parabiosis has been made. Electron microscopically, in the bone marrow of lethally irradiated rats, hemorrhage occurred due to detachment of sinus endothelial cells. Afterwards, reticulum cells with small intracytoplasmic lipid droplets appeared. On day 3, these cells were rapidly replaced by the reticulum cells with large lipid droplets, and resulted in fatty marrow within 7 days. Spindle-shaped fibroblastoid reticulum cells were also observed. In the bone marrow of lethally irradiated rats parabiosed with non-treated litter mates, hemopoiesis was initiated by adhesion of nucleated blood cells to intricated fine cytoplasmic pseudopods of fat-storage cells. On days 3 to 5, in parallel with progressive hemopoietic recovery, fibroblastoid and reticulum cells with large lipid droplets decreased whereas those with small droplets increased. On day 8, reticulum cells with lipid droplets were seldom seen, and hemopoietic distribution became the same as normal. These results suggested that bone marrow stromal cells, namely reticulum, fat-storage, and fibroblastoid cells share a common cellular origin, and also that they regain their structure and function when fat-storage cells were placed in contact with hemopoietic precursor cells.

  3. Radiation carcinogenesis. Progress report IV, 15 March 1976--15 May 1977

    International Nuclear Information System (INIS)

    Warren, S.; Gates, O.

    1977-01-01

    The series of parabiont and irradiated rats has been completed, the lesions diagnosed and the data pertinent to tumors computerized and partly analyzed. The same series yielded 74 percent incidence of cataract in the irradiated partner following a whole-body dose of 1000 R with 0.2 percent in the shielded partner and also in controls. There was no abscopal effect. Other structures of the eye beside the lens, particularly the retina, showed extensive radiation damage. Parabiosis increased the incidence rate of leukemia from one percent in control single rats to five percent. Irradiation of one partner decreased the rate to 2.5 percent. Similar effects were noted for solid lymphoid tumors. A pilot study of prostatic cancer in irradiated parabiont rats demonstrated a tenfold increase in incidence. Experimental protocols bearing on cocarcinogenesis have been initiated in mice and rats, using radiation, asbestos and chemical carcinogens, but no results have been as yet obtained. We have obtained additional evidence suggesting the importance of prolactin as a cocarcinogen with radiation for induction of mammary tumors in the rat and are continuing our collaborative study of hormonal aasays in the blood of parabiont rats

  4. Radiation carcinogenesis. Progress report III, 15 March 1975--15 March 1976

    International Nuclear Information System (INIS)

    Warren, S.; Gates, O.

    1976-03-01

    The attention of forensic pathologists has been drawn to the criteria essential for the recognition of radiation death or injury in the hope that such cases will be better recognized and that some false claims of radiation damage might be prevented at the local level. The results of experiments on parabiont rats, one of which had been irradiated with 1000 R of 250 kVp x-ray, the other shielded, are reviewed. With controls and related special studies the total is over 3000 pairs equally divided as to sex. Much information on the relative sensitivity of different tissues and organs to tumor induction is available and is being statistically analyzed. These experiments have provided further evidence of the effectiveness of parabiosis in assuring survival after 1000 R x-radiation and have enabled us to learn of the types of problems that might be expected in the way of late effects in heavily irradiated individuals should they be enabled by effective therapy to survive the acute phases of the radiation syndrome. Additional evidence has been brought out that carcinogenesis in some hormonally dependent tissues and organs is not so much a direct effect of radiation as it is a summation of this effect and of alterations caused by changes in hormonal balance brought about by the radiation

  5. Radiation carcinogenesis. Progress report VI, 16 May 1978--15 May 1979

    International Nuclear Information System (INIS)

    Warren, S.; Gates, O.

    1979-01-01

    Asbestos fibers, Canadian and Rhodesian chrysotile, have induced mesotheliomas and pleural plaques in mice and rats. The pathogenesis of the lesions is being studied. Proliferation of the adrenal cortical A cells is accelerated in time and enhanced in extent by ionizing radiation in female RAP mice. The development of cortical tumors was significantly correlated with extensive A cell proliferation. Whole-body protracted doses, above 500 rads, were followed by a 9% tumor incidence. Endocrine neoplasia in mice appears related to functional ties between several endocrines particularly adrenal, ovary, and pituitary. A study of the spontaneous benign and malignant tumors ocurring in control NEDH rats has provided background for the tumorigenic effects of radiation and also of altered hormonal internal milieu. Begin tumors have been produced by radiation in a wide variety of tissues for the first time, providing data as to the relative responsiveness in benign tumor production of various tissues to a dose of 1000 rads. The hormonal changes secondary to parabiosis and hemi-irradiation of the pair are important. A radiation-induced functioning pheochromocytoma causing hypertension and death has been found widely useful by investigators. A radiation-induced malignant insulinoma has also been widely used, and insulin-producing DNA from it has served in the hands of others through genetic engineering to provide an insulin-producing strain of the bacillus E. coli

  6. Radiation carcinogenesis. Progress report V, 16 May 1977--15 May 1978

    International Nuclear Information System (INIS)

    Warren, S.; Gates, O.

    1978-01-01

    Experiments are underway on the cocarcinogenic effects of asbestos and carcinogenic hydrocarbons using rats and mice as test objects. None of the protocols of these experiments have as yet been completed. The study of tumorigenesis in irradiated parabiont rats has been completed. Study of the benign tumors indicates that radiation is an effective neoplastic stimulus for only a limited number of organs and tissues, chiefly ovary, adrenal, mammary tissue, islands of Langerhans, and liver. In general the benign tumors did not seriously affect health, and in only a very few animals did they become malignant. The incidence of malignant tumors in the parabiont series has been tabulated and analyzed. Parabiosis alone appears to increase the incidence of leukemia and solid lymphoid tumors in NEDH rats. Our study of radiation tumorigenesis in the adrenal cortest in the mouse has been completed. The cortex is highly resistant to tumor induction by irradiation. Cortical tumorigenesis is strongly influenced by changes in pituitary and ovarian hormones. Proliferation of capsular ''A'' cells appears to be an important early factor in carcinogenesis. Hormonal imbalance continues to be an important factor in tumorigenesis in the parabiont pairs. If each of a pair of parabiont rats is irradiated sequentially at intervals, 30 days after a lethal dose of radiation is enough to permit the irradiated rat to support its partner through a like dose as effectively as would an unirradiated animal. The transplantable radiation-induced functioning pheochromocytoma and insulinoma of rats continue to be valuable research tools

  7. Evidence against a systemic humoral factor controlling the intestinal compensatory response following X-irradiation

    International Nuclear Information System (INIS)

    Sharp, J.G.; Osborne, J.W.; Iowa Univ., Iowa City

    1981-01-01

    The investigation was devised to determine whether changes noted in the unirradiated duodenum and colon of single rats after X-irradiation of only the exteriorized rat jejunum and ileum are mediated by a systemic humoral factor. Littermate Holtzman male rats were joined in parabiosis and one month later, the temporarily exteriorized jejunum and ileum of one member was exposed to 1.000 R of 250 kVp X-irradiation. Two days after X-irradiation, and 1, 12 and 24 h after 1 μCi/g bodyweight 3 H-thymidine was injected i.p. rats were sacrificed and appropriate tissues removed. Single rats which had the exteriorized jejunum and ileum irradiated were studied from 1-3 days after irradiation. Crypt cell migration rates were determined employing autoradiography. Tritium content and columnar cell migration rate in duodenum and colon of unirradiated rats compared to irradiated rats indicated that irradiation of one member of the pair had no effect on tritium incorporation or epithelial cell migration in the duodenum or colon of the unirradiated partner. Epithelial cell proliferation and crypt cell migration were increased in unirradiated duodenum and colon of single intestine-irradiated rats. Essentially the same changes were seen in the irradiated member of a parabiotic pair, but none of these changes were noted in the unirradiated member. The absence of stimulation in the unirradiated parabiont suggests that either a systemic humoral factor is not present after X-irradiation or is not present in sufficient concentration to be detected by these methods. (orig./MG)

  8. Fusion between Intestinal epithelial cells and macrophages in a cancer context results in nuclear reprogramming.

    Science.gov (United States)

    Powell, Anne E; Anderson, Eric C; Davies, Paige S; Silk, Alain D; Pelz, Carl; Impey, Soren; Wong, Melissa H

    2011-02-15

    The most deadly phase in cancer progression is attributed to the inappropriate acquisition of molecular machinery leading to metastatic transformation and spread of disease to distant organs. Although it is appreciated that metastasis involves epithelial-mesenchymal interplay, the underlying mechanism defining this process is poorly understood. Specifically, how cancer cells evade immune surveillance and gain the ability to navigate the circulatory system remains a focus. One possible mechanism underlying metastatic conversion is fusion between blood-derived immune cells and cancer cells. While this notion is a century old, in vivo evidence that cell fusion occurs within tumors and imparts genetic or physiologic changes remains controversial. We have previously demonstrated in vivo cell fusion between blood cells and intestinal epithelial cells in an injury setting. Here, we hypothesize that immune cells, such as macrophages, fuse with tumor cells imparting metastatic capabilities by transferring their cellular identity. We used parabiosis to introduce fluorescent-labeled bone marrow-derived cells to mice with intestinal tumors, finding that fusion between circulating blood-derived cells and tumor epithelium occurs during the natural course of tumorigenesis. Moreover, we identify the macrophage as a key cellular partner for this process. Interestingly, cell fusion hybrids retain a transcriptome identity characteristic of both parental derivatives, while also expressing a unique subset of transcripts. Our data supports the novel possibility that tumorigenic cell fusion may impart physical behavior attributed to migratory macrophages, including navigation of circulation and immune evasion. As such, cell fusion may represent a promising novel mechanism underlying the metastatic conversion of cancer cells. ©2011 AACR.

  9. Regulatory T cells and skeletal muscle regeneration.

    Science.gov (United States)

    Schiaffino, Stefano; Pereira, Marcelo G; Ciciliot, Stefano; Rovere-Querini, Patrizia

    2017-02-01

    Skeletal muscle regeneration results from the activation and differentiation of myogenic stem cells, called satellite cells, located beneath the basal lamina of the muscle fibers. Inflammatory and immune cells have a crucial role in the regeneration process. Acute muscle injury causes an immediate transient wave of neutrophils followed by a more persistent infiltration of M1 (proinflammatory) and M2 (anti-inflammatory/proregenerative) macrophages. New studies show that injured muscle is also infiltrated by a specialized population of regulatory T (Treg) cells, which control both the inflammatory response, by promoting the M1-to-M2 switch, and the activation of satellite cells. Treg cells accumulate in injured muscle in response to specific cytokines, such as IL-33, and promote muscle growth by releasing growth factors, such as amphiregulin. Muscle repair during aging is impaired due to reduced number of Treg cells and can be enhanced by IL-33 supplementation. Migration of Treg cells could also contribute to explain the effect of heterochronic parabiosis, whereby muscle regeneration of aged mice can be improved by a parabiotically linked young partners. In mdx dystrophin-deficient mice, a model of human Duchenne muscular dystrophy, muscle injury, and inflammation is mitigated by expansion of the Treg-cell population but exacerbated by Treg-cell depletion. These findings support the notion that immunological mechanisms are not only essential in the response to pathogenic microbes and tumor cells but also have a wider homeostatic role in tissue repair, and open new perspectives for boosting muscle growth in chronic muscle disease and during aging. © 2016 Federation of European Biochemical Societies.

  10. Gastritis promotes an activated bone marrow-derived mesenchymal stem cell with a phenotype reminiscent of a cancer-promoting cell.

    Science.gov (United States)

    Donnelly, Jessica M; Engevik, Amy C; Engevik, Melinda; Schumacher, Michael A; Xiao, Chang; Yang, Li; Worrell, Roger T; Zavros, Yana

    2014-03-01

    Bone marrow-derived mesenchymal stem cells (BM-MSCs) promote gastric cancer in response to gastritis. In culture, BM-MSCs are prone to mutation with continued passage but it is unknown whether a similar process occurs in vivo in response to gastritis. The purpose of this study was to identify the role of chronic gastritis in the transformation of BM-MSCs leading to an activated cancer-promoting phenotype. Age matched C57BL/6 (BL/6) and gastrin deficient (GKO) mice were used for isolation of stomach, serum and mesenchymal stem cells (MSCs) at 3 and 6 months of age. MSC activation was assessed by growth curve analysis, fluorescence-activated cell sorting and xenograft assays. To allow for the isolation of bone marrow-derived stromal cells and assay in response to chronic gastritis, IRG/Vav-1(Cre) mice that expressed both enhanced green fluorescent protein-expressing hematopoietic cells and red fluorescent protein-expressing stromal cells were generated. In a parabiosis experiment, IRG/Vav-1(Cre) mice were paired to either an uninfected Vav-1(Cre) littermate or a BL/6 mouse inoculated with Helicobacter pylori. GKO mice displayed severe atrophic gastritis accompanied by elevated gastric tissue and circulating transforming growth factor beta (TGFβ) by 3 months of age. Compared to BM-MSCs isolated from uninflamed BL/6 mice, BM-MSCs isolated from GKO mice displayed an increased proliferative rate and elevated phosphorylated-Smad3 suggesting active TGFβ signaling. In xenograft assays, mice injected with BM-MSCs from 6-month-old GKO animals displayed tumor growth. RFP+ stromal cells were rapidly recruited to the gastric mucosa of H. pylori parabionts and exhibited changes in gene expression. Gastritis promotes the in vivo activation of BM-MSCs to a phenotype reminiscent of a cancer-promoting cell.

  11. T-helper 17 and interleukin-17-producing lymphoid tissue inducer-like cells make different contributions to colitis in mice.

    Science.gov (United States)

    Ono, Yuichi; Kanai, Takanori; Sujino, Tomohisa; Nemoto, Yasuhiro; Kanai, Yasumasa; Mikami, Yohei; Hayashi, Atsushi; Matsumoto, Atsuhiro; Takaishi, Hiromasa; Ogata, Haruhiko; Matsuoka, Katsuyoshi; Hisamatsu, Tadakazu; Watanabe, Mamoru; Hibi, Toshifumi

    2012-11-01

    T helper (Th) 17 cells that express the retinoid-related orphan receptor (ROR) γt contribute to the development of colitis in mice, yet are found in normal and inflamed intestine. We investigated their development and functions in intestines of mice. We analyzed intestinal Th17 cells in healthy and inflamed intestinal tissues of mice. We analyzed expression of lymphotoxin (LT)α by Th17 cells and lymphoid tissue inducer-like cells. LTα(-/-) and RORγt(-/-) mice had significantly lower percentages of naturally occurring Th17 cells in the small intestine than wild-type mice. Numbers of CD3(-)CD4(+/-)interleukin-7Rα(+)c-kit(+)CCR6(+)NKp46(-) lymphoid tissue inducer-like cells that produce interleukin-17A were increased in LTα(-/-) and LTα(-/-) × recombination activating gene (RAG)-2(-/-) mice, compared with wild-type mice, but were absent from RORγt(-/-) mice. Parabiosis of wild-type and LTα(-/-) mice and bone marrow transplant experiments revealed that LTα-dependent gut-associated lymphoid tissue structures are required for generation of naturally occurring Th17 cells. However, when wild-type or LTα(-/-) CD4(+)CD45RB(high) T cells were transferred to RAG-2(-/-) or LTα(-/-)×RAG-2(-/-) mice, all groups, irrespective of the presence or absence of LTα on the donor or recipient cells, developed colitis and generated Th1, Th17, and Th17/Th1 cells. RAG-2(-/-) mice that received a second round of transplantation, with colitogenic but not naturally occurring Th17 cells, developed intestinal inflammation. The presence of naturally occurring Th17 cells in the colons of mice inhibited development of colitis after transfer of CD4(+)CD45RB(high) T cells and increased the numbers of Foxp3(+) cells derived from CD4(+)CD45RB(high) T cells. Gut-associated lymphoid tissue structures are required to generate naturally occurring Th17 cells that have regulatory activities in normal intestines of mice, but not for colitogenic Th17 and Th17/Th1 cells during inflammation