WorldWideScience

Sample records for cell niche myofibroblast

  1. Hepatic stem cell niches

    OpenAIRE

    Kordes, Claus; Häussinger, Dieter

    2013-01-01

    Stem cell niches are special microenvironments that maintain stem cells and control their behavior to ensure tissue homeostasis and regeneration throughout life. The liver has a high regenerative capacity that involves stem/progenitor cells when the proliferation of hepatocytes is impaired. In recent years progress has been made in the identification of potential hepatic stem cell niches. There is evidence that hepatic progenitor cells can originate from niches in the canals...

  2. Artificial Stem Cell Niches

    OpenAIRE

    Lutolf, Matthias P.; Blau, Helen M.

    2009-01-01

    Stem cells are characterized by their dual ability to reproduce themselves (self-renew) and specialize (differentiate), yielding a plethora of daughter cells that maintain and regenerate tissues. In contrast to their embryonic counterparts, adult stem cells retain their unique functions only if they are in intimate contact with an instructive microenvironment, termed stem cell niche. In these niches, stem cells integrate a complex array of molecular signals that, in concert with induced cell-...

  3. Tenascins in stem cell niches.

    Science.gov (United States)

    Chiquet-Ehrismann, Ruth; Orend, Gertraud; Chiquet, Matthias; Tucker, Richard P; Midwood, Kim S

    2014-07-01

    Tenascins are extracellular matrix proteins with distinct spatial and temporal expression during development, tissue homeostasis and disease. Based on their expression patterns and knockout phenotypes an important role of tenascins in tissue formation, cell adhesion modulation, regulation of proliferation and differentiation has been demonstrated. All of these features are of importance in stem cell niches where a precise regulation of growth versus differentiation has to be guaranteed. In this review we summarize the expression and possible functions of tenascins in neural, epithelial and osteogenic stem cell niches during normal development and organ turnover, in the hematopoietic and pro-inflammatory niche as well as in the metastatic niche during cancer progression. PMID:24472737

  4. Myofibroblastic Conversion and Regeneration of Mesothelial Cells in Peritoneal and Liver Fibrosis.

    Science.gov (United States)

    Lua, Ingrid; Li, Yuchang; Pappoe, Lamioko S; Asahina, Kinji

    2015-12-01

    Mesothelial cells (MCs) form a single epithelial layer and line the surface of body cavities and internal organs. Patients who undergo peritoneal dialysis often develop peritoneal fibrosis that is characterized by the accumulation of myofibroblasts in connective tissue. Although MCs are believed to be the source of myofibroblasts, their contribution has remained obscure. We determined the contribution of peritoneal MCs to myofibroblasts in chlorhexidine gluconate (CG)-induced fibrosis compared with that of phenotypic changes of liver MCs. CG injections resulted in disappearance of MCs from the body wall and the accumulation of myofibroblasts in the connective tissue. Conditional linage tracing with Wilms tumor 1 (Wt1)-CreERT2 and Rosa26 reporter mice found that 17% of myofibroblasts were derived from MCs in peritoneal fibrosis. Conditional deletion of transforming growth factor-β type II receptor in Wt1(+) MCs substantially reduced peritoneal fibrosis. The CG treatment also induced myofibroblastic conversion of MCs in the liver. Lineage tracing with Mesp1-Cre mice revealed that Mesp1(+) mesoderm gave rise to liver MCs but not peritoneal MCs. During recovery from peritoneal fibrosis, peritoneal MCs, but not liver MCs, contribute to the regeneration of the peritoneal mesothelium, indicating an inherent difference between parietal and visceral MCs. In conclusion, MCs partially contribute to myofibroblasts in peritoneal and liver fibrosis, and protection of the MC layer leads to reduced development of fibrous tissue. PMID:26598235

  5. Adhesion in the stem cell niche: biological roles and regulation

    OpenAIRE

    Chen, Shuyi; Lewallen, Michelle; Xie, Ting

    2013-01-01

    Stem cell self-renewal is tightly controlled by the concerted action of stem cell-intrinsic factors and signals within the niche. Niche signals often function within a short range, allowing cells in the niche to self-renew while their daughters outside the niche differentiate. Thus, in order for stem cells to continuously self-renew, they are often anchored in the niche via adhesion molecules. In addition to niche anchoring, however, recent studies have revealed other important roles for adhe...

  6. Bone Marrow Vascular Niche: Home for Hematopoietic Stem Cells

    OpenAIRE

    Ningning He; Lu Zhang; Jian Cui; Zongjin Li

    2014-01-01

    Though discovered later than osteoblastic niche, vascular niche has been regarded as an alternative indispensable niche operating regulation on hematopoietic stem cells (HSCs). As significant progresses gained on this type niche, it is gradually clear that the main work of vascular niche is undertaking to support hematopoiesis. However, compared to what have been defined in the mechanisms through which the osteoblastic niche regulates hematopoiesis, we know less in vascular niche. In this rev...

  7. The Cell as the First Niche Construction

    Directory of Open Access Journals (Sweden)

    John S. Torday

    2016-04-01

    Full Text Available Niche construction nominally describes how organisms can form their own environments, increasing their capacity to adapt to their surroundings. It is hypothesized that the formation of the first cell as ‘internal’ Niche Construction was the foundation for life, and that subsequent niche constructions were iterative exaptations of that event. The first instantation of niche construction has been faithfully adhered to by returning to the unicellular state, suggesting that the life cycle is zygote to zygote, not adult to adult as is commonly held. The consequent interactions between niche construction and epigenetic inheritance provide a highly robust, interactive, mechanistic way of thinking about evolution being determined by initial conditions rather than merely by chance mutation and selection. This novel perspective offers an opportunity to reappraise the processes involved in evolution mechanistically, allowing for scientifically testable hypotheses rather than relying on metaphors, dogma, teleology and tautology.

  8. The Cell as the First Niche Construction.

    Science.gov (United States)

    Torday, John S

    2016-01-01

    Niche construction nominally describes how organisms can form their own environments, increasing their capacity to adapt to their surroundings. It is hypothesized that the formation of the first cell as 'internal' Niche Construction was the foundation for life, and that subsequent niche constructions were iterative exaptations of that event. The first instantation of niche construction has been faithfully adhered to by returning to the unicellular state, suggesting that the life cycle is zygote to zygote, not adult to adult as is commonly held. The consequent interactions between niche construction and epigenetic inheritance provide a highly robust, interactive, mechanistic way of thinking about evolution being determined by initial conditions rather than merely by chance mutation and selection. This novel perspective offers an opportunity to reappraise the processes involved in evolution mechanistically, allowing for scientifically testable hypotheses rather than relying on metaphors, dogma, teleology and tautology. PMID:27136594

  9. The FOXD1 lineage of kidney perivascular cells and myofibroblasts: functions and responses to injury

    Science.gov (United States)

    Gomez, Ivan G; Duffield, Jeremy S

    2014-01-01

    Recent studies have identified a poorly appreciated yet extensive population of perivascular mesenchymal cells in the kidney, which are derived from metanephric mesenchyme progenitor cells during nephrogenesis at which time they express the transcription factor FOXD1. Some studies have called these resident fibroblasts, whereas others have called them pericytes. Regardless of nomenclature, many are partially integrated into the capillary basement membrane and contribute in important ways to the homeostasis of peritubular capillaries. Fate-mapping studies using conditional CreER recombinase-mediated tracing of discrete cell cohorts have identified these pericytes and resident fibroblasts as the major precursor population of interstitial myofibroblasts in animal models of kidney disease. Here, we will review the evidence that they are the major population of myofibroblast precursors, highlight some critical functions in homeostasis, and focus on the cell signaling pathways that are important to their differentiation into, and persistence as myofibroblasts. PMID:26312147

  10. Niche construction game cancer cells play

    Science.gov (United States)

    Bergman, Aviv; Gligorijevic, Bojana

    2015-10-01

    Niche construction concept was originally defined in evolutionary biology as the continuous interplay between natural selection via environmental conditions and the modification of these conditions by the organism itself. Processes unraveling during cancer metastasis include construction of niches, which cancer cells use towards more efficient survival, transport into new environments and preparation of the remote sites for their arrival. Many elegant experiments were done lately illustrating, for example, the premetastatic niche construction, but there is practically no mathematical modeling done which would apply the niche construction framework. To create models useful for understanding niche construction role in cancer progression, we argue that a) genetic, b) phenotypic and c) ecological levels are to be included. While the model proposed here is phenomenological in its current form, it can be converted into a predictive outcome model via experimental measurement of the model parameters. Here we give an overview of an experimentally formulated problem in cancer metastasis and propose how niche construction framework can be utilized and broadened to model it. Other life science disciplines, such as host-parasite coevolution, may also benefit from niche construction framework adaptation, to satisfy growing need for theoretical considerations of data collected by experimental biology.

  11. Acute myelogenous leukemia cells with the MLL-ELL translocation convert morphologically and functionally into adherent myofibroblasts

    International Nuclear Information System (INIS)

    Bone marrow-myofibroblasts, a major component of bone marrow-stroma, are reported to originate from hematopoietic stem cells. We show in this paper that non-adherent leukemia blasts can change into myofibroblasts. When myeloblasts from two cases of acute myelogenous leukemia with a fusion product comprising mixed lineage leukemia and RNA polymerase II elongation factor, were cultured long term, their morphology changed to that of myofibroblasts with similar molecular characteristics to the parental myeloblasts. The original leukemia blasts, when cultured on the leukemia blast-derived myofibroblasts, grew extensively. Leukemia blasts can create their own microenvironment for proliferation.

  12. Tubular engraftment and myofibroblast differentiation of recipient-derived cells after experimental kidney transplantation

    NARCIS (Netherlands)

    Broekema, Martine; Harmsen, Martin C.; Koerts, Jasper A.; Van Kooten, Theo G.; Navis, Gerjan; Van Luyn, Marja J. A.; Popa, Eliane R.

    2007-01-01

    Background. In human renal allografts, recipient-derived cells engrafted in various kidney substructures, have been detected in the long term after transplantation. Here we investigated tubular engraftment and myofibroblast differentiation of recipient-derived cells at short term after experimental

  13. A reverse Warburg metabolism in oral squamous cell carcinoma is not dependent upon myofibroblasts

    DEFF Research Database (Denmark)

    Jensen, David Hebbelstrup; Therkildsen, Marianne Hamilton; Dabelsteen, Erik

    2015-01-01

    expression of MCT-4 have been shown to have prognostic importance, primarily in patients with breast cancer. However, this phenomenon has only scarcely been described in oral squamous cell carcinoma (OSCC). Given the prognostic importance of myofibroblasts in OSCC, we also examined a potential relationship...... cancer observed as a lack of stromal caveolin-1 (CAV-1) and an increased expression of monocarboxylate transporter 4 (MCT-4) in the tumour stroma, with a concomitant increase in the expression of monocarboxylate transporter 1 (MCT-1) in the epithelial, tumour compartment. The lack of CAV-1 and increased...... between the expression of MCT-4 and the presence of myofibroblasts....

  14. Cancer exosomes trigger mesenchymal stem cell differentiation into pro-angiogenic and pro-invasive myofibroblasts.

    Science.gov (United States)

    Chowdhury, Ridwana; Webber, Jason P; Gurney, Mark; Mason, Malcolm D; Tabi, Zsuzsanna; Clayton, Aled

    2015-01-20

    Stromal fibroblasts become altered in response to solid cancers, to exhibit myofibroblastic characteristics, with disease promoting influence. Infiltrating mesenchymal stem cells (MSC) may contribute towards these changes, but the factors secreted by cancer cells that impact MSC differentiation are poorly understood. We investigated the role of nano-metre sized vesicles (exosomes), secreted by prostate cancer cells, on the differentiation of bone-marrow MSC (BM-MSC), and the subsequent functional consequences of such changes. Purified exosomes impaired classical adipogenic differentiation, skewing differentiation towards alpha-smooth muscle actin (αSMA) positive myofibroblastic cells. A single exosomes treatment generated myofibroblasts secreting high levels of VEGF-A, HGF and matrix regulating factors (MMP-1, -3 and -13). Differentiated MSC had pro-angiogenic functions and enhanced tumour proliferation and invasivity assessed in a 3D co-culture model. Differentiation was dependent on exosomal-TGFβ, but soluble TGFβ at matched dose could not generate the same phenotype. Exosomes present in the cancer cell secretome were the principal factors driving this phenotype. Prostate cancer exosomes dominantly dictate a programme of MSC differentiation generating myofibroblasts with functional properties consistent with disease promotion. PMID:25596732

  15. Do laser and led phototherapies influence mast cells and myofibroblasts to produce collagen?

    Science.gov (United States)

    De Castro, Isabele Cardoso Vieira; Rocha, Clarissa Araújo Gurgel; Gomes Henriques, Aguida Cristina; Cavalcanti de Sousa, Ana Paula; Lisboa, Márcio Vieira; Sotero, Drielli da Rocha; Pinheiro, Antônio Luiz Barbosa; Cury, Patrícia Ramos; Santos, Jean Nunes Dos

    2014-07-01

    Laser and LED phototherapies accelerate tissue repair. Mast cells induce the proliferation of fibroblasts and the development of local fibrosis. Increased numbers of myofibroblasts and mast cells are frequently found together in a normal wound repair, suggesting that mediators produced by the mast cells could play a role in the regulation of myofibroblast differentiation and function. The aim of this study was to analyze the involvement of mast cells on the synthesis of collagen and their influence on myofibroblast differentiation in the late phase of tissue repair on wounds treated with LLLT (λ 660 nm, 10 J/cm(2), 40 mW, 252 s) or LED (λ 630 ± 10 nm, 10 J/cm(2), 115 mW, 87 s). A 1 × 1-cm surgical wound was created on the dorsum of 30 rats divided into three groups of ten animals each: control, laser, and LED. The animals of each group were irradiated and sacrificed 7 and 14 days after injury. The statistical analysis was performed using the Mann-Whitney and Spearman correlation tests. Laser light improved the collagen deposition rate along the time points (p = 0.22), but when compared to the control groups during the periods studied, the number of mast cells decreased significantly (p ≤ 0.05). With respect to myofibroblasts, the results showed a trend to their reduction. No statistical significances were observed for LED light according to the parameters used in this study. It is concluded that the mast cell and myofibroblast population might participate in the collagen formation of irradiated wounds particularly in relation to laser phototherapy. PMID:24554451

  16. Ultraporous nanofeatured PCL-PEO microfibrous scaffolds enhance cell infiltration, colonization and myofibroblastic differentiation

    Science.gov (United States)

    Li, Yan-Fang; Gregersen, Hans; Nygaard, Jens Vinge; Cheng, Weilu; Yu, Ying; Huang, Yudong; Dong, Mingdong; Besenbacher, Flemming; Chen, Menglin

    2015-09-01

    In the field of tissue engineering, integration of micro-porosity, nano-topogaphical features and weattability into one three-dimensional (3D) scaffold remains a challenge. The extracellular matrix (ECM) mimicking feature of electrospun fibers endows them wide applications in tissue engineering. However, the tight-packing of electrospun submicron fibers hinder cell infiltration and further colonization. In this study, we fabricated hydrophilic, micro-porous scaffolds with nano-topographical cues by one-step electrospinning, and investigated NIH3T3 fibroblasts cell infiltration, colonization and myofibroblastic differentiation. The hierarchical porosity enhanced cell infiltration and proliferation significantly. Besides, the nano-topography influenced the cell actin distribution and cell morphology that stimulated myofibroblastic differentiation in a drastically different manner from that of traditional solid, smooth electrospun fibers, which may hold great potential in reconstructing tissues that require strong contractile forces.In the field of tissue engineering, integration of micro-porosity, nano-topogaphical features and weattability into one three-dimensional (3D) scaffold remains a challenge. The extracellular matrix (ECM) mimicking feature of electrospun fibers endows them wide applications in tissue engineering. However, the tight-packing of electrospun submicron fibers hinder cell infiltration and further colonization. In this study, we fabricated hydrophilic, micro-porous scaffolds with nano-topographical cues by one-step electrospinning, and investigated NIH3T3 fibroblasts cell infiltration, colonization and myofibroblastic differentiation. The hierarchical porosity enhanced cell infiltration and proliferation significantly. Besides, the nano-topography influenced the cell actin distribution and cell morphology that stimulated myofibroblastic differentiation in a drastically different manner from that of traditional solid, smooth electrospun fibers

  17. Mimicking Stem Cell Niches to Increase Stem Cell Expansion

    OpenAIRE

    Dellatore, Shara M.; Garcia, A. Sofia; Miller, William M.

    2008-01-01

    Niches regulate lineage-specific stem cell self-renewal vs. differentiation in vivo and are comprised of supportive cells and extracellular matrix components arranged in a 3-dimensional topography of controlled stiffness in the presence of oxygen and growth factor gradients. Mimicking stem cell niches in a defined manner will facilitate production of the large numbers of stem cells needed to realize the promise of regenerative medicine and gene therapy. Progress has been made in mimicking com...

  18. Myofibroblasts are distinguished from activated skin fibroblasts by the expression of AOC3 and other associated markers.

    Science.gov (United States)

    Hsia, Lin-Ting; Ashley, Neil; Ouaret, Djamila; Wang, Lai Mun; Wilding, Jennifer; Bodmer, Walter F

    2016-04-12

    Pericryptal myofibroblasts in the colon and rectum play an important role in regulating the normal colorectal stem cell niche and facilitating tumor progression. Myofibroblasts previously have been distinguished from normal fibroblasts mostly by the expression of α smooth muscle actin (αSMA). We now have identified AOC3 (amine oxidase, copper containing 3), a surface monoamine oxidase, as a new marker of myofibroblasts by showing that it is the target protein of the myofibroblast-reacting mAb PR2D3. The normal and tumor tissue distribution and the cell line reactivity of AOC3 match that expected for myofibroblasts. We have shown that the surface expression of AOC3 is sensitive to digestion by trypsin and collagenase and that anti-AOC3 antibodies can be used for FACS sorting of myofibroblasts obtained by nonenzymatic procedures. Whole-genome microarray mRNA-expression profiles of myofibroblasts and skin fibroblasts revealed four additional genes that are significantly differentially expressed in these two cell types: NKX2-3 and LRRC17 in myofibroblasts and SHOX2 and TBX5 in skin fibroblasts. TGFβ substantially down-regulated AOC3 expression in myofibroblasts but in skin fibroblasts it dramatically increased the expression of αSMA. A knockdown of NKX2-3 in myofibroblasts caused a decrease of myofibroblast-related gene expression and increased expression of the fibroblast-associated gene SHOX2, suggesting that NKX2-3 is a key mediator for maintaining myofibroblast characteristics. Our results show that colorectal myofibroblasts, as defined by the expression of AOC3, NKX2-3, and other markers, are a distinctly different cell type from TGFβ-activated fibroblasts. PMID:27036009

  19. Fibroblast-myofibroblast transition is differentially regulated by bronchial epithelial cells from asthmatic children

    OpenAIRE

    Reeves, Stephen R; Kolstad, Tessa; Lien, Tin-Yu; Herrington-Shaner, Sarah; Debley, Jason S.

    2015-01-01

    Background Airway remodeling is a proposed mechanism that underlies the persistent loss of lung function associated with childhood asthma. Previous studies have demonstrated that human lung fibroblasts (HLFs) co-cultured with primary human bronchial epithelial cells (BECs) from asthmatic children exhibit greater expression of extracellular matrix (ECM) components compared to co-culture with BECs derived from healthy children. Myofibroblasts represent a population of differentiated fibroblasts...

  20. Niche

    OpenAIRE

    O'Donovan, Danielle

    2001-01-01

    Capital of middle niche/sedilia of south nave wall, moulding from top down comprises: chamfer, fillet, hollow, stiff-leaf foliage, bell, necking roll-and-fillet. Here again Early English characteristics are manifest but the niche may date from the later middle ages.

  1. A stem cell niche dominance theorem

    Directory of Open Access Journals (Sweden)

    Shibata Darryl K

    2011-01-01

    Full Text Available Abstract Background Multilevelness is a defining characteristic of complex systems. For example, in the intestinal tissue the epithelial lining is organized into crypts that are maintained by a niche of stem cells. The behavior of the system 'as a whole' is considered to emerge from the functioning and interactions of its parts. What we are seeking here is a conceptual framework to demonstrate how the "fate" of intestinal crypts is an emergent property that inherently arises from the complex yet robust underlying biology of stem cells. Results We establish a conceptual framework in which to formalize cross-level principles in the context of tissue organization. To this end we provide a definition for stemness, which is the propensity of a cell lineage to contribute to a tissue fate. We do not consider stemness a property of a cell but link it to the process in which a cell lineage contributes towards tissue (malfunction. We furthermore show that the only logically feasible relationship between the stemness of cell lineages and the emergent fate of their tissue, which satisfies the given criteria, is one of dominance from a particular lineage. Conclusions The dominance theorem, conceived and proven in this paper, provides support for the concepts of niche succession and monoclonal conversion in intestinal crypts as bottom-up relations, while crypt fission is postulated to be a top-down principle.

  2. Cutaneous amelanotic signet-ring cell malignant melanoma with interspersed myofibroblastic differentiation in a young cat.

    Science.gov (United States)

    Hirz, Manuela; Herden, Christiane

    2016-07-01

    The diagnosis of malignant melanoma can be difficult because these tumors can be amelanotic and may contain diverse variants and divergent differentiations, of which the signet-ring cell subtype is very rare and has only been described in humans, dogs, cats, and a hamster. We describe herein histopathologic and immunohistochemical approaches taken to diagnose a case of signet-ring cell malignant melanoma with myofibroblastic differentiation in a cat. A tumor within the abdominal skin of a 2-year-old cat was composed of signet-ring cells and irregularly interwoven streams of spindle cells. Both neoplastic cell types were periodic-acid-Schiff, Fontana, and Sudan black B negative. Signet-ring cells strongly expressed vimentin and S100 protein. Spindle cells strongly expressed vimentin and smooth muscle actin; some cells expressed S100, moderately neuron-specific enolase, and others variably actin and desmin. A few round cells expressed melan A, and a few plump spindle cells expressed melan A and PNL2, confirming the diagnosis of amelanotic signet-ring cell malignant melanoma with myofibroblastic differentiation in a cat. Differential diagnoses were excluded, including signet-ring cell forms of adenocarcinomas, lymphomas, liposarcomas, leiomyosarcomas, squamous cell carcinomas, basal cell carcinomas, and adnexal tumors. PMID:27154314

  3. Bone Marrow Vascular Niche: Home for Hematopoietic Stem Cells

    Directory of Open Access Journals (Sweden)

    Ningning He

    2014-01-01

    Full Text Available Though discovered later than osteoblastic niche, vascular niche has been regarded as an alternative indispensable niche operating regulation on hematopoietic stem cells (HSCs. As significant progresses gained on this type niche, it is gradually clear that the main work of vascular niche is undertaking to support hematopoiesis. However, compared to what have been defined in the mechanisms through which the osteoblastic niche regulates hematopoiesis, we know less in vascular niche. In this review, based on research data hitherto we will focus on component foundation and various functions of vascular niche that guarantee the normal hematopoiesis process within bone marrow microenvironments. And the possible pathways raised by various research results through which this environment undergoes its function will be discussed as well.

  4. Niche-modulated and niche-modulating genes in bone marrow cells

    International Nuclear Information System (INIS)

    Bone marrow (BM) cells depend on their niche for growth and survival. However, the genes modulated by niche stimuli have not been discriminated yet. For this purpose, we investigated BM aspirations from patients with various hematological malignancies. Each aspirate was fractionated, and the various samples were fixed at different time points and analyzed by microarray. Identification of niche-modulated genes relied on sustained change in expression following loss of niche regulation. Compared with the reference (‘authentic') samples, which were fixed immediately following aspiration, the BM samples fixed after longer stay out-of-niche acquired numerous changes in gene-expression profile (GEP). The overall genes modulated included a common subset of functionally diverse genes displaying prompt and sustained ‘switch' in expression irrespective of the tumor type. Interestingly, the ‘switch' in GEP was reversible and turned ‘off-and-on' again in culture conditions, resuming cell–cell–matrix contact versus respread into suspension, respectively. Moreover, the resuming of contact prolonged the survival of tumor cells out-of-niche, and the regression of the ‘contactless switch' was followed by induction of a new set of genes, this time mainly encoding extracellular proteins including angiogenic factors and extracellular matrix proteins. Our data set, being unique in authentic expression design, uncovered niche-modulated and niche-modulating genes capable of controlling homing, expansion and angiogenesis

  5. Human embryonic stem cells create their own niche

    Institute of Scientific and Technical Information of China (English)

    Ying Jin

    2007-01-01

    @@ Experimental evidence demonstrates that the ability of stem cells to self-renew and to differentiate into different types of mature cells depends on both their intrinsic genetic programs and external control from their microenvironment or niche. The concept of stem cell niche was first proposed by Schofield in 1978 to describe a microenvironment that supports stem cells in a mammalian hematopoietic system [ 1 ].

  6. Multipotent properties of myofibroblast cells derived from human placenta

    OpenAIRE

    Strakova, Zuzana; Livak, Mark; Krezalek, Monika; Ihnatovych, Ivanna

    2008-01-01

    Human uterine fibroblasts (HuF) isolated from the maternal part (decidua parietalis) of a term placenta provide a useful model of in vitro cell differentiation into decidual cells (decidualization), critical for successful pregnancy. After isolation, the cells adhere to plastic and have either a small round or spindle-shaped morphology which later changes into a flattened pattern in culture. HuF robustly proliferate in culture until passage 20 and form colonies when plated at low densities. T...

  7. Niche

    OpenAIRE

    O'Donovan, Danielle

    2001-01-01

    Arch and hood moulding of westernmost niche of south nave wall. Arch moulding from inner surface comprises: chamfer, flat surface, hollow, roll-and-fillet, roll, hollow, chamfer, flat surface of wall. The hood, from outside face to inner comprises: roll-and-fillet, hollow, chamfer. The style of this moulding can best be described as debased Early English. The roll-and-fillet is particularly deformed.

  8. Chronic Myelogenous Leukemia Cells Contribute to the Stromal Myofibroblasts in Leukemic NOD/SCID Mouse In Vivo

    Directory of Open Access Journals (Sweden)

    Ryosuke Shirasaki

    2012-01-01

    Full Text Available We recently reported that chronic myelogenous leukemia (CML cells converted into myofibroblasts to create a microenvironment for proliferation of CML cells in vitro. To analyze a biological contribution of CML-derived myofibroblasts in vivo, we observed the characters of leukemic nonobese diabetes/severe combined immunodeficiency (NOD/SCID mouse. Bone marrow nonadherent mononuclear cells as well as human CD45-positive cells obtained from CML patients were injected to the irradiated NOD/SCID mice. When the chimeric BCR-ABL transcript was demonstrated in blood, human CML cells were detected in NOD/SCID murine bone marrow. And CML-derived myofibroblasts composed with the bone marrow-stroma, which produced significant amounts of human vascular endothelial growth factor A. When the parental CML cells were cultured with myofibroblasts separated from CML cell-engrafted NOD/SCID murine bone marrow, CML cells proliferated significantly. These observations indicate that CML cells make an adequate microenvironment for their own proliferation in vivo.

  9. Myofibroblasts in Fibrotic Kidneys

    Science.gov (United States)

    Nakagawa, Naoki; Duffield, Jeremy S

    2013-01-01

    Fibrosis of the kidney glomerulus and interstitium are characteristic features of almost all chronic kidney diseases. Fibrosis is tightly associated with destruction of capillaries, inflammation, and epithelial injury which progresses to loss of nephrons, and replacement of kidney parenchyma with scar tissue. Understanding the origins and nature of the cells known as myofibroblasts that make scar tissue is central to development of new therapeutics for kidney disease. Whereas many cell lineages in the body have become defined by well-established markers, myofibroblasts have been much harder to identify with certainty. Recent insights from genetic fate mapping and the use of dynamic reporting of cells that make fibrillar collagen in mice have identified with greater clarity the major population of myofibroblasts and their precursors in the kidney. This review will explore the nature of these cells in health and disease of the kidney to underst and their central role in the pathogenesis of kidney disease. PMID:24187654

  10. Stem cell autotomy and niche interaction in different systems

    OpenAIRE

    Dorn, David C.; Dorn, August

    2015-01-01

    The best known cases of cell autotomy are the formation of erythrocytes and thrombocytes (platelets) from progenitor cells that reside in special niches. Recently, autotomy of stem cells and its enigmatic interaction with the niche has been reported from male germline stem cells (GSCs) in several insect species. First described in lepidopterans, the silkmoth, followed by the gipsy moth and consecutively in hemipterans, foremost the milkweed bug. In both, moths and the milkweed bug, GSCs form ...

  11. Stem cell autotomy and niche interaction in different systems.

    Science.gov (United States)

    Dorn, David C; Dorn, August

    2015-07-26

    The best known cases of cell autotomy are the formation of erythrocytes and thrombocytes (platelets) from progenitor cells that reside in special niches. Recently, autotomy of stem cells and its enigmatic interaction with the niche has been reported from male germline stem cells (GSCs) in several insect species. First described in lepidopterans, the silkmoth, followed by the gipsy moth and consecutively in hemipterans, foremost the milkweed bug. In both, moths and the milkweed bug, GSCs form finger-like projections toward the niche, the apical cells (homologs of the hub cells in Drosophila). Whereas in the milkweed bug the projection terminals remain at the surface of the niche cells, in the gipsy moth they protrude deeply into the singular niche cell. In both cases, the projections undergo serial retrograde fragmentation with progressing signs of autophagy. In the gipsy moth, the autotomized vesicles are phagocytized and digested by the niche cell. In the milkweed bug the autotomized vesicles accumulate at the niche surface and disintegrate. Autotomy and sprouting of new projections appears to occur continuously. The significance of the GSC-niche interactions, however, remains enigmatic. Our concept on the signaling relationship between stem cell-niche in general and GSC and niche (hub cells and cyst stem cells) in particular has been greatly shaped by Drosophila melanogaster. In comparing the interactions of GSCs with their niche in Drosophila with those in species exhibiting GSC autotomy it is obvious that additional or alternative modes of stem cell-niche communication exist. Thus, essential signaling pathways, including niche-stem cell adhesion (E-cadherin) and the direction of asymmetrical GSC division - as they were found in Drosophila - can hardly be translated into the systems where GSC autotomy was reported. It is shown here that the serial autotomy of GSC projections shows remarkable similarities with Wallerian axonal destruction, developmental axon

  12. Stem cell autotomy and niche interaction in differentsystems

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    The best known cases of cell autotomy are theformation of erythrocytes and thrombocytes (platelets)from progenitor cells that reside in special niches.Recently, autotomy of stem cells and its enigmaticinteraction with the niche has been reported from malegermline stem cells (GSCs) in several insect species.First described in lepidopterans, the silkmoth, followedby the gipsy moth and consecutively in hemipterans,foremost the milkweed bug. In both, moths and themilkweed bug, GSCs form finger-like projectionstoward the niche, the apical cells (homologs of thehub cells in Drosophila). Whereas in the milkweedbug the projection terminals remain at the surfaceof the niche cells, in the gipsy moth they protrudedeeply into the singular niche cell. In both cases, theprojections undergo serial retrograde fragmentationwith progressing signs of autophagy. In the gipsy moth,the autotomized vesicles are phagocytized and digestedby the niche cell. In the milkweed bug the autotomizedvesicles accumulate at the niche surface and disintegrate.Autotomy and sprouting of new projectionsappears to occur continuously. The significance of theGSC-niche interactions, however, remains enigmatic.Our concept on the signaling relationship betweenstem cell-niche in general and GSC and niche (hubcells and cyst stem cells) in particular has been greatlyshaped by Drosophila melanogaster. In comparingthe interactions of GSCs with their niche in Drosophilawith those in species exhibiting GSC autotomy itis obvious that additional or alternative modes ofstem cell-niche communication exist. Thus, essentialsignaling pathways, including niche-stem cell adhesion(E-cadherin) and the direction of asymmetrical GSCdivision - as they were found in Drosophila - can hardlybe translated into the systems where GSC autotomy was reported. It is shown here that the serial autotomyof GSC projections shows remarkable similarities withWallerian axonal destruction, developmental axonpruning and dying

  13. Stochastic dynamics of interacting haematopoietic stem cell niche lineages.

    Directory of Open Access Journals (Sweden)

    Tamás Székely

    2014-09-01

    Full Text Available Since we still know very little about stem cells in their natural environment, it is useful to explore their dynamics through modelling and simulation, as well as experimentally. Most models of stem cell systems are based on deterministic differential equations that ignore the natural heterogeneity of stem cell populations. This is not appropriate at the level of individual cells and niches, when randomness is more likely to affect dynamics. In this paper, we introduce a fast stochastic method for simulating a metapopulation of stem cell niche lineages, that is, many sub-populations that together form a heterogeneous metapopulation, over time. By selecting the common limiting timestep, our method ensures that the entire metapopulation is simulated synchronously. This is important, as it allows us to introduce interactions between separate niche lineages, which would otherwise be impossible. We expand our method to enable the coupling of many lineages into niche groups, where differentiated cells are pooled within each niche group. Using this method, we explore the dynamics of the haematopoietic system from a demand control system perspective. We find that coupling together niche lineages allows the organism to regulate blood cell numbers as closely as possible to the homeostatic optimum. Furthermore, coupled lineages respond better than uncoupled ones to random perturbations, here the loss of some myeloid cells. This could imply that it is advantageous for an organism to connect together its niche lineages into groups. Our results suggest that a potential fruitful empirical direction will be to understand how stem cell descendants communicate with the niche and how cancer may arise as a result of a failure of such communication.

  14. Inflammatory myofibroblastic tumor

    Directory of Open Access Journals (Sweden)

    Sangeeta Palaskar

    2011-01-01

    Full Text Available Inflammatory myofibroblastic tumor is an uncommon lesion of unknown cause. It encompasses a spectrum of myofibroblastic proliferation along with varying amount of inflammatory infiltrate. A number of terms have been applied to the lesion, namely, inflammatory pseudotumor, fibrous xanthoma, plasma cell granuloma, pseudosarcoma, lymphoid hamartoma, myxoid hamartoma, inflammatory myofibrohistiocytic proliferation, benign myofibroblatoma, and most recently, inflammatory myofibroblastic tumor. The diverse nomenclature is mostly descriptive and reflects the uncertainty regarding true biologic nature of these lesions. Recently, the concept of this lesion being reactive has been challenged based on the clinical demonstration of recurrences and metastasis and cytogenetic evidence of acquired clonal chromosomal abnormalities. We hereby report a case of inflammatory pseudotumor and review its inflammatory versus neoplastic behavior.

  15. Three-Dimensional Polydopamine Functionalized Coiled Microfibrous Scaffolds Enhance Human Mesenchymal Stem Cells Colonization and Mild Myofibroblastic Differentiation.

    Science.gov (United States)

    Taskin, Mehmet Berat; Xu, Ruodan; Gregersen, Hans; Nygaard, Jens Vinge; Besenbacher, Flemming; Chen, Menglin

    2016-06-29

    Electrospinning has been widely applied for tissue engineering due to its versatility of fabricating extracellular matrix (ECM) mimicking fibrillar scaffolds. Yet there are still challenges such as that these two-dimensional (2D) tightly packed, hydrophobic fibers often hinder cell infiltration and cell-scaffold integration. In this study, polycaprolactone (PCL) was electrospun into a grounded coagulation bath collector, resulting in 3D coiled microfibers with in situ surface functionalization with hydrophilic, catecholic polydopamine (pDA). The 3D scaffolds showed biocompatibility and were well-integrated with human bone marrow derived human mesenchymal stem cells (hMSCs), with significantly higher cell penetration depth compared to that of the 2D PCL microfibers from traditional electrospinning. Further differentiation of human mesenchymal stem cells (hMSCs) into fibroblast phenotype in vitro indicates that, compared to the stiff, tightly packed, 2D scaffolds which aggravated myofibroblasts related activities, such as upregulated gene and protein expression of α-smooth muscle actin (α-SMA), 3D scaffolds induced milder myofibroblastic differentiation. The flexible 3D fibers further allowed contraction with the well-integrated, mechanically active myofibroblasts, monitored under live-cell imaging, whereas the stiff 2D scaffolds restricted that. PMID:27265317

  16. Looking for the elusive lung stem cell niche.

    Science.gov (United States)

    Banerjee, Ena Ray

    2014-01-01

    This discourse contains three perspectives on various aspects of Stem Cell Biology and tools available to study and translate into Regenerative Medicine. The lung incessantly faces onslaught of the environment, constantly undergoes oxidative stress, and is an important organ of detoxification. In degenerative diseases and inflammation, the lung undergoes irreversible remodeling that is difficult to therapeutically address and/or transplant a dying tissue. The other difficulty is to study its development and regenerative aspects to best address the aforementioned problems. This perspective therefore addresses- firstly, review of types of stem cells, their pathway of action and models in invertebrate organisms vis-a-vis microenvironment and its dynamics; secondly, stem cells in higher organisms and niche; and lastly data and inference on a novel approach to study stem cell destruction patterns in an injury model and information on putative lung stem cell niche. Stem cells are cryptic cells known to retain certain primitive characteristics making them akin to ancient cells of invertebrates, developmental stages in invertebrates and vertebrates and pliant cells of complex creatures like mammals that demonstrate stimulus-specific behavious, whether to clonally propagate or to remain well protected and hidden within specialized niches, or mobilize and differentiate into mature functionally operative cells to house-keep, repair injury or make new tissues. In lung fibrosis, alveolar epithelium degenerates progressively. In keeping with the goal of regenerative medicine, various models and assays to evaluate long and short term identity of stem cells and their niches is the subject of this perspective. We also report identification and characterization of functional lung stem cells to clarify how stem cell niches counteract this degenerative process. Inferences drawn from this injury model of lung degeneration using a short term assay by tracking side population cells and a

  17. Mouse Incisor Stem Cell Niche and Myb Transcription Factors

    Czech Academy of Sciences Publication Activity Database

    Švandová, Eva; Veselá, Barbora; Šmarda, J.; Hampl, A.; Radlanski, R.J.; Matalová, Eva

    2015-01-01

    Roč. 44, č. 5 (2015), s. 338-344. ISSN 0340-2096 R&D Projects: GA ČR GAP304/11/1418; GA ČR GCP302/12/J059 Institutional support: RVO:67985904 Keywords : c-Myb * stem cell niches Subject RIV: EA - Cell Biology Impact factor: 0.672, year: 2014

  18. Myofibroblasts in Fibrotic Kidneys

    OpenAIRE

    Nakagawa, Naoki; Duffield, Jeremy S.

    2013-01-01

    Fibrosis of the kidney glomerulus and interstitium are characteristic features of almost all chronic kidney diseases. Fibrosis is tightly associated with destruction of capillaries, inflammation, and epithelial injury which progresses to loss of nephrons, and replacement of kidney parenchyma with scar tissue. Understanding the origins and nature of the cells known as myofibroblasts that make scar tissue is central to development of new therapeutics for kidney disease. Whereas many cell lineag...

  19. Engineering stem cell niches in bioreactors

    OpenAIRE

    2013-01-01

    Stem cells, including embryonic stem cells, induced pluripotent stem cells, mesenchymal stem cells and amniotic fluid stem cells have the potential to be expanded and differentiated into various cell types in the body. Efficient differentiation of stem cells with the desired tissue-specific function is critical for stem cell-based cell therapy, tissue engineering, drug discovery and disease modeling. Bioreactors provide a great platform to regulate the stem cell microenvironment, known as “ni...

  20. Maintenance of Stem Cell Niche Integrity by a Novel Activator of Integrin Signaling.

    OpenAIRE

    Joo Yeun Lee; Chen, Jessica Y.; Jillian L Shaw; Chang, Karen T.

    2016-01-01

    Stem cells depend critically on the surrounding microenvironment, or niche, for their maintenance and self-renewal. While much is known about how the niche regulates stem cell self-renewal and differentiation, mechanisms for how the niche is maintained over time are not well understood. At the apical tip of the Drosophila testes, germline stem cells (GSCs) and somatic stem cells share a common niche formed by hub cells. Here we demonstrate that a novel protein named Shriveled (Shv) is necessa...

  1. The hematopoietic stem cell and its niche: a comparative view.

    Science.gov (United States)

    Martinez-Agosto, Julian A; Mikkola, Hanna K A; Hartenstein, Volker; Banerjee, Utpal

    2007-12-01

    Stem cells have been identified as a source of virtually all highly differentiated cells that are replenished during the lifetime of an animal. The critical balance between stem and differentiated cell populations is crucial for the long-term maintenance of functional tissue types. Stem cells maintain this balance by choosing one of several alternate fates: self-renewal, commitment to differentiate, and senescence or cell death. These characteristics comprise the core criteria by which these cells are usually defined. The self-renewal property is important, as it allows for extended production of the corresponding differentiated cells throughout the life span of the animal. A microenvironment that is supportive of stem cells is commonly referred to as a stem cell niche. In this review, we first present some general concepts regarding stem cells and their niches, comparing stem cells of many different kinds from diverse organisms, and in the second part, we compare specific aspects of hematopoiesis and the niches that support hematopoiesis in Drosophila, zebrafish and mouse. PMID:18056420

  2. A new image of the hematopoietic stem cell vascular niche

    OpenAIRE

    Silberstein, Leslie E.; Lin, Charles P.

    2013-01-01

    The microenvironment within the bone marrow that maintains hematopoietic stem cell (HSC) quiescence is the subject of intense study. In a recent Nature paper, Kunisaki et al combine imaging techniques and computational modeling to define a novel arteriolar niche for quiescent HSCs within the bone marrow.

  3. Conjunctival polyploid cells and donor-derived myofibroblasts in ocular GvHD.

    Science.gov (United States)

    Hallberg, D; Stenberg, K; Hanson, C; Stenevi, U; Brune, M

    2016-05-01

    After allogeneic hematopoietic stem cell transplantation (allo-SCT), ocular GvHD is a common complication, typical symptoms being dry eye syndrome with features of fibrosis. In this study, we have identified and quantified two cell types-myofibroblasts (MFB) and polyploid (PP) cells-in the conjunctival surface of allo-SCT patients (pts) and have explored their kinetics and association with local and systemic GvHD. Results are compared with control groups of (a) pretransplant samples from allo-SCT patients, (b) recipients of autologous transplantation (auto-SCT) and (c) healthy controls. Imprint cytologies were obtained by pressing the conjunctival surface with a sterile, non-abrasive cellulose acetate filter (Millipore). After retraction, typically a monolayer of the outermost cells of the epithelium were retrieved. MFB were identified by immunofluorescent (IF) staining for alpha-smooth muscle protein. PP cells were detected by aberrant chromosome content analyzed via X/Y-FISH (X/Y fluorescence in situ hybridization). In female pts with a male donor (MF group), donor genotype were identified by sex chromosome detection using FISH methodology. IF and FISH methods were applied in situ on the same filter, and amounts of MFB and PP cells are expressed as the percentage of all cells on the filter. In all, 70 samples from 46 pts were obtained 1-122 months after allo-SCT. The total MFB density (MFB(TOT)) was higher in allo-SCT pts compared with healthy individuals and auto-SCT pts and increased by time after transplantation (PXY)), whereas recipient-derived MFB (MFB(XX)) did not vary over time. Clinical ocular GvHD correlated with MFB(XY)/MFB(TOT) ratio (P=0.034), whereas no association between MFB(TOT) or MFB(XY) systemic GvHD was observed. In the MF group (n=25), both MFB(XY) and MFB(XX) were detected on 28 of the 37 imprints (76%). In pts >36 months post transplant, on 11/12 imprints, a median of 9.4% (1.4-39%) MFB(XY) and 3.6% (0-11%) MFB(XX) was found. In one

  4. Simulation of proliferation and differentiation of cells in a stem-cell niche

    Science.gov (United States)

    Zhdanov, Vladimir P.

    2008-10-01

    Stem-cell niches represent microscopic compartments formed of environmental cells that nurture stem cells and enable them to maintain tissue homeostasis. The spatio-temporal kinetics of proliferation and differentiation of cells in such niches depend on the specifics of the niche structure and on adhesion and communication between cells and may also be influenced by spatial constraints on cell division. We propose a generic lattice model, taking all these factors into account, and systematically illustrate their role. The model is motivated by the experimental data available for the niches located in the subventricular zone of adult mammalian brain. The general conclusions drawn from our Monte Carlo simulations are applicable to other niches as well. One of our main findings is that the kinetics under consideration are highly stochastic due to a relatively small number of cells proliferating and differentiating in a niche and the autocatalytic character of the symmetric cell division. In particular, the kinetics exhibit huge stochastic bursts especially if the adhesion between cells is taken into account. In addition, the results obtained show that despite the small number of cells present in stem-cell niches, their arrangement can be predetermined to appreciable extent provided that the adhesion of different cells is different so that they tend to segregate.

  5. Niche interactions in epidermal stem cells

    Institute of Scientific and Technical Information of China (English)

    Hye-Ryung Choi; Sang-Young Byun; Soon-Hyo Kwon; Kyoung-Chan Park

    2015-01-01

    Within the epidermis and dermis of the skin, cellssecrete and are surrounded by the extracellular matrix(ECM), which provides structural and biochemicalsupport. The ECM of the epidermis is the basementmembrane, and collagen and other dermal componentsconstitute the ECM of the dermis. There is significantvariation in the composition of the ECM of the epidermisand dermis, which can affect "cell to cell" and "cellto ECM" interactions. These interactions, in turn, caninfluence biological responses, aging, and woundhealing; abnormal ECM signaling likely contributes toskin diseases. Thus, strategies for manipulating cell-ECM interactions are critical for treating wounds and avariety of skin diseases. Many of these strategies focuson epidermal stem cells, which reside in a unique nichein which the ECM is the most important component;interactions between the ECM and epidermal stemcells play a major role in regulating stem cell fate. Asthey constitute a major portion of the ECM, it is likelythat integrins and type Ⅳ collagens are important instem cell regulation and maintenance. In this review,we highlight recent research-including our previouswork-exploring the role that the ECM and its associatedcomponents play in shaping the epidermal stem cellniche.

  6. Three-Dimensional Gastrointestinal Organoid Culture in Combination with Nerves or Fibroblasts: A Method to Characterize the Gastrointestinal Stem Cell Niche.

    Science.gov (United States)

    Pastuła, Agnieszka; Middelhoff, Moritz; Brandtner, Anna; Tobiasch, Moritz; Höhl, Bettina; Nuber, Andreas H; Demir, Ihsan Ekin; Neupert, Steffi; Kollmann, Patrick; Mazzuoli-Weber, Gemma; Quante, Michael

    2016-01-01

    The gastrointestinal epithelium is characterized by a high turnover of cells and intestinal stem cells predominantly reside at the bottom of crypts and their progeny serve to maintain normal intestinal homeostasis. Accumulating evidence demonstrates the pivotal role of a niche surrounding intestinal stem cells in crypts, which consists of cellular and soluble components and creates an environment constantly influencing the fate of stem cells. Here we describe different 3D culture systems to culture gastrointestinal epithelium that should enable us to study the stem cell niche in vitro in the future: organoid culture and multilayered systems such as organotypic cell culture and culture of intestinal tissue fragments ex vivo. These methods mimic the in vivo situation in vitro by creating 3D culture conditions that reflect the physiological situation of intestinal crypts. Modifications of the composition of the culture media as well as coculturing epithelial organoids with previously described cellular components such as myofibroblasts, collagen, and neurons show the impact of the methods applied to investigate niche interactions in vitro. We further present a novel method to isolate labeled nerves from the enteric nervous system using Dclk1-CreGFP mice. PMID:26697073

  7. Three-Dimensional Gastrointestinal Organoid Culture in Combination with Nerves or Fibroblasts: A Method to Characterize the Gastrointestinal Stem Cell Niche

    Directory of Open Access Journals (Sweden)

    Agnieszka Pastuła

    2016-01-01

    Full Text Available The gastrointestinal epithelium is characterized by a high turnover of cells and intestinal stem cells predominantly reside at the bottom of crypts and their progeny serve to maintain normal intestinal homeostasis. Accumulating evidence demonstrates the pivotal role of a niche surrounding intestinal stem cells in crypts, which consists of cellular and soluble components and creates an environment constantly influencing the fate of stem cells. Here we describe different 3D culture systems to culture gastrointestinal epithelium that should enable us to study the stem cell niche in vitro in the future: organoid culture and multilayered systems such as organotypic cell culture and culture of intestinal tissue fragments ex vivo. These methods mimic the in vivo situation in vitro by creating 3D culture conditions that reflect the physiological situation of intestinal crypts. Modifications of the composition of the culture media as well as coculturing epithelial organoids with previously described cellular components such as myofibroblasts, collagen, and neurons show the impact of the methods applied to investigate niche interactions in vitro. We further present a novel method to isolate labeled nerves from the enteric nervous system using Dclk1-CreGFP mice.

  8. Protein Profiling of Isolated Leukocytes, Myofibroblasts, Epithelial, Basal, and Endothelial Cells from Normal, Hyperplastic, Cancerous, and Inflammatory Human Prostate Tissues

    Directory of Open Access Journals (Sweden)

    Zahraa I. Khamis, Kenneth A. Iczkowski, Ziad J. Sahab, Qing-Xiang Amy Sang

    2010-01-01

    Full Text Available In situ neoplastic prostate cells are not lethal unless they become invasive and metastatic. For cells to become invasive, the prostate gland must undergo degradation of the basement membrane and disruption of the basal cell layer underneath the luminal epithelia. Although the roles of proteinases in breaking down the basement membrane have been well-studied, little is known about the factors that induce basal cell layer disruption, degeneration, and its eventual disappearance in invasive cancer. It is hypothesized that microenvironmental factors may affect the degradation of the basal cell layer, which if protected may prevent tumor progression and invasion. In this study, we have revealed differential protein expression patterns between epithelial and stromal cells isolated from different prostate pathologies and identified several important epithelial and stromal proteins that may contribute to inflammation and malignant transformation of human benign prostate tissues to cancerous tissues using matrix-assisted laser desorption ionization time-of-flight mass spectrometry and proteomics methods. Cellular retinoic acid-binding protein 2 was downregulated in basal cells of benign prsotate. Caspase-1 and interleukin-18 receptor 1 were highly expressed in leukocytes of prostate cancer. Proto-oncogene Wnt-3 was downregulated in endothelial cells of prostatitis tissue and tyrosine phosphatase non receptor type 1 was only found in normal and benign endothelial cells. Poly ADP-ribose polymerase 14 was downregulated in myofibroblasts of prostatitis tissue. Interestingly, integrin alpha-6 was upregulated in epithelial cells but not detected in myofibroblasts of prostate cancer. Further validation of these proteins may generate new strategies for the prevention of basal cell layer disruption and subsequent cancer invasion.

  9. The bone marrow stem cell niche grows up: mesenchymal stem cells and macrophages move in (Review)

    OpenAIRE

    Ehninger, A; Trumpp, A

    2011-01-01

    Stem cell niches are defined as the cellular and molecular microenvironments that regulate stem cell function together with stem cell autonomous mechanisms. This includes control of the balance between quiescence, self-renewal, and differentiation, as well as the engagement of specific programs in response to stress. In mammals, the best understood niche is that harboring bone marrow hematopoietic stem cells (HSCs). Recent studies have expanded the number of cell types contributing to the HSC...

  10. A stromal cell niche for human and mouse type 3 innate lymphoid cells

    OpenAIRE

    Hoorweg, Kerim; Narang, Priyanka; Li, Zhi; Thuery, Anne; Papazian, Natalie; Withers, David R; Coles, Mark C.; Cupedo, Tom

    2015-01-01

    Adaptive immunity critically depends on the functional compartmentalization of secondary lymphoid organs. Mesenchymal stromal cells create and maintain specialized niches that support survival, activation and expansion of T and B cells, and integrated analysis of lymphocytes and their niche has been instrumental in understanding adaptive immunity. Lymphoid organs are also home to type 3 innate lymphoid cells (ILC3), innate effector cells essential for barrier immunity. However, a specialized ...

  11. Enabling stem cell therapies through synthetic stem cell–niche engineering

    OpenAIRE

    Peerani, Raheem; Zandstra, Peter W.

    2010-01-01

    Enabling stem cell–targeted therapies requires an understanding of how to create local microenvironments (niches) that stimulate endogenous stem cells or serve as a platform to receive and guide the integration of transplanted stem cells and their derivatives. In vivo, the stem cell niche is a complex and dynamic unit. Although components of the in vivo niche continue to be described for many stem cell systems, how these components interact to modulate stem cell fate is only beginning to be u...

  12. Implications of irradiating the subventricular zone stem cell niche

    Directory of Open Access Journals (Sweden)

    Vivian Capilla-Gonzalez

    2016-03-01

    Full Text Available Radiation therapy is a standard treatment for brain tumor patients. However, it comes with side effects, such as neurological deficits. While likely multi-factorial, the effect may in part be associated with the impact of radiation on the neurogenic niches. In the adult mammalian brain, the neurogenic niches are localized in the subventricular zone (SVZ of the lateral ventricles and the dentate gyrus of the hippocampus, where the neural stem cells (NSCs reside. Several reports showed that radiation produces a drastic decrease in the proliferative capacity of these regions, which is related to functional decline. In particular, radiation to the SVZ led to a reduced long-term olfactory memory and a reduced capacity to respond to brain damage in animal models, as well as compromised tumor outcomes in patients. By contrast, other studies in humans suggested that increased radiation dose to the SVZ may be associated with longer progression-free survival in patients with high-grade glioma. In this review, we summarize the cellular and functional effects of irradiating the SVZ niche. In particular, we review the pros and cons of using radiation during brain tumor treatment, discussing the complex relationship between radiation dose to the SVZ and both tumor control and toxicity.

  13. Niche appropriation by Drosophila intestinal stem cell tumours.

    Science.gov (United States)

    Patel, Parthive H; Dutta, Devanjali; Edgar, Bruce A

    2015-09-01

    Mutations that inhibit differentiation in stem cell lineages are a common early step in cancer development, but precisely how a loss of differentiation initiates tumorigenesis is unclear. We investigated Drosophila intestinal stem cell (ISC) tumours generated by suppressing Notch (N) signalling, which blocks differentiation. Notch-defective ISCs require stress-induced divisions for tumour initiation and an autocrine EGFR ligand, Spitz, during early tumour growth. On achieving a critical mass these tumours displace surrounding enterocytes, competing with them for basement membrane space and causing their detachment, extrusion and apoptosis. This loss of epithelial integrity induces JNK and Yki/YAP activity in enterocytes and, consequently, their expression of stress-dependent cytokines (Upd2, Upd3). These paracrine signals, normally used within the stem cell niche to trigger regeneration, propel tumour growth without the need for secondary mutations in growth signalling pathways. The appropriation of niche signalling by differentiation-defective stem cells may be a common mechanism of early tumorigenesis. PMID:26237646

  14. Cigarette Smoke Alters the Hematopoietic Stem Cell Niche

    Directory of Open Access Journals (Sweden)

    Robert W. Siggins

    2014-02-01

    Full Text Available Effects of tobacco smoke on hematologic derangements have received little attention. This study employed a mouse model of cigarette smoke exposure to explore the effects on bone marrow niche function. While lung cancer is the most widely studied consequence of tobacco smoke exposure, other malignancies, including leukemia, are associated with tobacco smoke exposure. Animals received cigarette smoke exposure for 6 h/day, 5 days/week for 9 months. Results reveal that the hematopoietic stem and progenitor cell (HSPC pool size is reduced by cigarette smoke exposure. We next examined the effect of cigarette smoke exposure on one supporting cell type of the niche, the mesenchymal stromal cells (MSCs. Smoke exposure decreased the number of MSCs. Transplantation of naïve HSPCs into irradiated mice with cigarette smoke exposure yielded fewer numbers of engrafted HSPCs. This result suggests that smoke-exposed mice possess dysfunctional niches, resulting in abnormal hematopoiesis. Co-culture experiments using MSCs isolated from control or cigarette smoke-exposed mice with naïve HSPCs in vitro showed that MSCs from cigarette smoke-exposed mice generated marked expansion of naïve HSPCs. These data show that cigarette smoke exposure decreases in vivo MSC and HSC number and also increases pro-proliferative gene expression by cigarette smoke-exposed MSCs, which may stimulate HSPC expansion. These results of this investigation are clinically relevant to both bone marrow donors with a history of smoking and bone marrow transplant (BMT recipients with a history of smoking.

  15. NACA deficiency reveals the crucial role of somite-derived stromal cells in haematopoietic niche formation.

    Science.gov (United States)

    Murayama, Emi; Sarris, Milka; Redd, Michael; Le Guyader, Dorothée; Vivier, Catherine; Horsley, Wyatt; Trede, Nikolaus; Herbomel, Philippe

    2015-01-01

    The ontogeny of haematopoietic niches in vertebrates is essentially unknown. Here we show that the stromal cells of the caudal haematopoietic tissue (CHT), the first niche where definitive haematopoietic stem/progenitor cells (HSPCs) home in zebrafish development, derive from the caudal somites through an epithelial-mesenchymal transition (EMT). The resulting stromal cell progenitors accompany the formation of the caudal vein sinusoids, the other main component of the CHT niche, and mature into reticular cells lining and interconnecting sinusoids. We characterize a zebrafish mutant defective in definitive haematopoiesis due to a deficiency in the nascent polypeptide-associated complex alpha subunit (NACA). We demonstrate that the defect resides not in HSPCs but in the CHT niche. NACA-deficient stromal cell progenitors initially develop normally together with the sinusoids, and HSPCs home to the resulting niche, but stromal cell maturation is compromised, leading to a niche that is unable to support HSPC maintenance, expansion and differentiation. PMID:26411530

  16. Multipotent somatic stem cells contribute to the stem cell niche in the Drosophila testis.

    Science.gov (United States)

    Voog, Justin; D'Alterio, Cecilia; Jones, D Leanne

    2008-08-28

    Adult stem cells reside in specialized microenvironments, or niches, that have an important role in regulating stem cell behaviour. Therefore, tight control of niche number, size and function is necessary to ensure the proper balance between stem cells and progenitor cells available for tissue homeostasis and wound repair. The stem cell niche in the Drosophila male gonad is located at the tip of the testis where germline and somatic stem cells surround the apical hub, a cluster of approximately 10-15 somatic cells that is required for stem cell self-renewal and maintenance. Here we show that somatic stem cells in the Drosophila testis contribute to both the apical hub and the somatic cyst cell lineage. The Drosophila orthologue of epithelial cadherin (DE-cadherin) is required for somatic stem cell maintenance and, consequently, the apical hub. Furthermore, our data indicate that the transcriptional repressor escargot regulates the ability of somatic cells to assume and/or maintain hub cell identity. These data highlight the dynamic relationship between stem cells and the niche and provide insight into genetic programmes that regulate niche size and function to support normal tissue homeostasis and organ regeneration throughout life. PMID:18641633

  17. Lymphatic endothelial cells are a replicative niche for Mycobacterium tuberculosis

    Science.gov (United States)

    Lerner, Thomas R.; de Souza Carvalho-Wodarz, Cristiane; Repnik, Urska; Russell, Matthew R.G.; Borel, Sophie; Diedrich, Collin R.; Rohde, Manfred; Wainwright, Helen; Collinson, Lucy M.; Wilkinson, Robert J.; Griffiths, Gareth; Gutierrez, Maximiliano G.

    2016-01-01

    In extrapulmonary tuberculosis, the most common site of infection is within the lymphatic system, and there is growing recognition that lymphatic endothelial cells (LECs) are involved in immune function. Here, we identified LECs, which line the lymphatic vessels, as a niche for Mycobacterium tuberculosis in the lymph nodes of patients with tuberculosis. In cultured primary human LECs (hLECs), we determined that M. tuberculosis replicates both in the cytosol and within autophagosomes, but the bacteria failed to replicate when the virulence locus RD1 was deleted. Activation by IFN-γ induced a cell-autonomous response in hLECs via autophagy and NO production that restricted M. tuberculosis growth. Thus, depending on the activation status of LECs, autophagy can both promote and restrict replication. Together, these findings reveal a previously unrecognized role for hLECs and autophagy in tuberculosis pathogenesis and suggest that hLECs are a potential niche for M. tuberculosis that allows establishment of persistent infection in lymph nodes. PMID:26901813

  18. Lymphatic endothelial cells are a replicative niche for Mycobacterium tuberculosis.

    Science.gov (United States)

    Lerner, Thomas R; de Souza Carvalho-Wodarz, Cristiane; Repnik, Urska; Russell, Matthew R G; Borel, Sophie; Diedrich, Collin R; Rohde, Manfred; Wainwright, Helen; Collinson, Lucy M; Wilkinson, Robert J; Griffiths, Gareth; Gutierrez, Maximiliano G

    2016-03-01

    In extrapulmonary tuberculosis, the most common site of infection is within the lymphatic system, and there is growing recognition that lymphatic endothelial cells (LECs) are involved in immune function. Here, we identified LECs, which line the lymphatic vessels, as a niche for Mycobacterium tuberculosis in the lymph nodes of patients with tuberculosis. In cultured primary human LECs (hLECs), we determined that M. tuberculosis replicates both in the cytosol and within autophagosomes, but the bacteria failed to replicate when the virulence locus RD1 was deleted. Activation by IFN-γ induced a cell-autonomous response in hLECs via autophagy and NO production that restricted M. tuberculosis growth. Thus, depending on the activation status of LECs, autophagy can both promote and restrict replication. Together, these findings reveal a previously unrecognized role for hLECs and autophagy in tuberculosis pathogenesis and suggest that hLECs are a potential niche for M. tuberculosis that allows establishment of persistent infection in lymph nodes. PMID:26901813

  19. Mouse Incisor Stem Cell Niche and Myb Transcription Factors.

    Science.gov (United States)

    Svandova, E; Vesela, B; Smarda, J; Hampl, A; Radlanski, R J; Matalova, E

    2015-10-01

    Dental hard tissues are formed particularly by odontoblasts (dentin) and ameloblasts (enamel). Whereas the reparation of dentin is often observed, enamel does not regenerate in most species. However, in mouse incisor, a population of somatic stem cells in the cervical loop is responsible for the incisor regeneration. Understanding of the specificities of these cells is therefore of an interest in basic research as well as regenerative therapies. The Myb transcription factors are involved in essential cellular processes. B-Myb is often linked to the stem cell phenotype, and c-Myb expression marks undifferentiated and proliferating cells such as the stem cells. In the presented study, temporo-spatial expression of B-Myb and c-Myb proteins was correlated with localisation of putative somatic stem cells in the mouse incisor cervical loop by immunohistochemistry. B-Myb expression was localised mostly in the zone of transit-amplifying cells, and c-Myb was found in the inner enamel epithelium, the surrounding mesenchyme and in differentiated cells. Taken together, neither B-Myb nor c-Myb was exclusively present or abundant in the area of the incisor stem cell niche. Their distribution, however, supports recently reported novel functions of c-Myb in differentiation of hard tissue cells. PMID:25182175

  20. Fibroblasts and myofibroblasts in wound healing

    Directory of Open Access Journals (Sweden)

    Darby IA

    2014-11-01

    Full Text Available Ian A Darby,1 Betty Laverdet,2 Frédéric Bonté3, Alexis Desmoulière2 1School of Medical Sciences, RMIT University, Melbourne, VIC, Australia; 2Department of Physiology and EA 6309, FR 3503, Faculties of Medicine and Pharmacy, University of Limoges, Limoges, France; 3LVMH Recherche, Saint Jean de Braye, France Abstract: (Myofibroblasts are key players for maintaining skin homeostasis and for orchestrating physiological tissue repair. (Myofibroblasts are embedded in a sophisticated extracellular matrix (ECM that they secrete, and a complex and interactive dialogue exists between (myofibroblasts and their microenvironment. In addition to the secretion of the ECM, (myofibroblasts, by secreting matrix metalloproteinases and tissue inhibitors of metalloproteinases, are able to remodel this ECM. (Myofibroblasts and their microenvironment form an evolving network during tissue repair, with reciprocal actions leading to cell differentiation, proliferation, quiescence, or apoptosis, and actions on growth factor bioavailability by binding, sequestration, and activation. In addition, the (myofibroblast phenotype is regulated by mechanical stresses to which they are subjected and thus by mechanical signaling. In pathological situations (excessive scarring or fibrosis, or during aging, this dialogue between the (myofibroblasts and their microenvironment may be altered or disrupted, leading to repair defects or to injuries with damaged and/or cosmetic skin alterations such as wrinkle development. The intimate dialogue between the (myofibroblasts and their microenvironment therefore represents a fascinating domain that must be better understood in order not only to characterize new therapeutic targets and drugs able to prevent or treat pathological developments but also to interfere with skin alterations observed during normal aging or premature aging induced by a deleterious environment. Keywords: myofibroblast, fibroblast, α-smooth muscle actin

  1. Not all renal stem cell niches are the same: anatomy of an evolution

    Directory of Open Access Journals (Sweden)

    Clara Gerosa

    2016-08-01

    Full Text Available The renal stem cell niche represents the most important structure of the developing kidney, responsible for nephrogenesis. Recently, some Authors have reported, at ultrastructural level, a previously unknown complexity of the architecture of renal stem cell niche in experimental models. This study was aimed at studying, at histological level, the anatomy of renal stem cell niches in the human fetal kidney. To this end, ten fetal kidneys, whose gestational ages ranged from 11 up to 24 weeks, were studied. H&E-stained sections were observed at high power. The study of the anatomy of renal stem cell niches in the human kidney revealed a previously unreported complexity: some niches appeared as a roundish arrangement of mesenchymal cells; others showed the initial phases of induction by ureteric buds; in other niches the process of mesenchymal epithelial transition was more evident; finally, in other stem cell niches the first signs of nephron origin were detectable. These findings suggest the existence of niches with different anatomy in the same kidney, indicating different stages of evolution even in adjacent niches. All stem cell niches were in strict contact with the capsular cells, suggesting a major role of the renal capsule in nephrogenesis. Finally, our study confirms the existence of a strict contact between the bud tip cells and the surrounding mesenchyme in the human developing kidney, giving a morphological support to the theory of intercellular channels allowing the passage of transcription factors from the epithelial to the mesenchymal stem/progenitors cells.Proceedings of the 2nd International Course on Perinatal Pathology (part of the 11th International Workshop on Neonatology · October 26th-31st, 2015 · Cagliari (Italy · October 31st, 2015 · Stem cells: present and future Guest Editors: Gavino Faa, Vassilios Fanos, Antonio Giordano

  2. The myofibroblast in wound healing and fibrosis: answered and unanswered questions [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Marie-Luce Bochaton-Piallat

    2016-04-01

    Full Text Available The discovery of the myofibroblast has allowed definition of the cell responsible for wound contraction and for the development of fibrotic changes. This review summarizes the main features of the myofibroblast and the mechanisms of myofibroblast generation. Myofibroblasts originate from a variety of cells according to the organ and the type of lesion. The mechanisms of myofibroblast contraction, which appear clearly different to those of smooth muscle cell contraction, are described. Finally, we summarize the possible strategies in order to reduce myofibroblast activities and thus influence several pathologies, such as hypertrophic scars and organ fibrosis.

  3. Does primary myelofibrosis involve a defective stem cell niche? From concept to evidence

    DEFF Research Database (Denmark)

    Lataillade, J.J.; Pierre-Louis, O.; Uzan, G.;

    2008-01-01

    Primary myelofibrosis (PMF) is the rarest and the most severe Philadelphia-negative chronic myeloproliferative syndrome. By associating a clonal proliferation and a mobilization of hematopoietic stem cells from bone marrow to spleen with profound alterations of the stroma, PMF is a remarkable model...... in which deregulation of the stem cell niche is of utmost importance for the disease development. This paper reviews key data suggesting that an imbalance between endosteal and vascular niches participates in the development of clonal stem cell proliferation. Mechanisms by which bone marrow niches...... are altered with ensuing mobilization and homing of neoplastic hematopoietic stem cells in new or reinitialized niches in the spleen and liver are examined. Differences between signals delivered by both endosteal and vascular niches in the bone marrow and spleen of patients as well as the responsiveness...

  4. NFIB is a governor of epithelial–melanocyte stem cell behaviour in a shared niche

    OpenAIRE

    Chang, Chiung-Ying; Pasolli, H. Amalia; Giannopoulou, Eugenia G.; Guasch, Géraldine; Gronostajski, Richard M; Elemento, Olivier; Fuchs, Elaine

    2013-01-01

    Adult stem cells reside in specialized niches where they receive environmental cues to maintain tissue homeostasis. In mammals, the stem cell niche within hair follicles is home to epithelial hair follicle stem cells and melanocyte stem cells, which sustain cyclical bouts of hair regeneration and pigmentation1–4. To generate pigmented hairs, synchrony is achieved such that upon initiation of a new hair cycle, stem cells of each type activate lineage commitment2,5. Dissecting the inter-stem-ce...

  5. Establishment of a long-term three-dimensional primary culture of mouse glandular stomach epithelial cells within the stem cell niche

    International Nuclear Information System (INIS)

    Highlights: ► We established a 3D culture system to allow long-term culture of stomach cells. ► In this culture system, gastric epithelial cells grew for about 3 months. ► The cultured cells differentiated into multi-units of the stomach. ► This culture method should be useful for elucidating the cause of gastric diseases. -- Abstract: Compared to the small intestine and colon, little is known about stem cells in the stomach because of a lack of specific stem cell markers and an in vitro system that allows long-term culture. Here we describe a long-term three-dimensional (3D) primary gastric culture system within the stem cell niche. Glandular stomach cells from neonatal mice cultured in collagen gel yielded expanding sphere-like structures for 3 months. The wall of the gastrospheres consisted of a highly polarized epithelial monolayer with an outer lining of myofibroblasts. The epithelial cells showed a tall columnar cell shape, basal round nuclei, and mucus-filled cytoplasm as well as expression of MUC5AC, indicating differentiation into gastric surface mucous cells. These cells demonstrated the features of fully differentiated gastric surface mucous cells such as microvilli, junctional complexes, and glycogen and secretory granules. Fewer than 1% of cultured epithelial cells differentiated into enteroendocrine cells. Active proliferation of the epithelial cells and many apoptotic cells in the inner lumen revealed the rapid cell turnover in gastrospheres in vitro. This method enables us to investigate the role of signaling between cell–cell and epithelial–mesenchymal interactions in an environment that is extremely similar to the in vivo environment

  6. Establishment of a long-term three-dimensional primary culture of mouse glandular stomach epithelial cells within the stem cell niche

    Energy Technology Data Exchange (ETDEWEB)

    Katano, Takahito [Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601 (Japan); Ootani, Akifumi [Department of Gastroenterology and GI Endoscopy Center, Shin-Kokura Hospital, Federation of National Public Service Personnel Mutual Aid Associations, 1-3-1 Kanada, Kokurakita-ku, Kitakyushu 803-0816 (Japan); Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501 (Japan); Mizoshita, Tsutomu, E-mail: tmizoshi@med.nagoya-cu.ac.jp [Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601 (Japan); Tanida, Satoshi; Tsukamoto, Hironobu; Ozeki, Keiji; Ebi, Masahide; Mori, Yoshinori; Kataoka, Hiromi; Kamiya, Takeshi [Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601 (Japan); Toda, Shuji [Department of Pathology and Microbiology, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501 (Japan); Joh, Takashi [Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601 (Japan)

    2013-03-22

    Highlights: ► We established a 3D culture system to allow long-term culture of stomach cells. ► In this culture system, gastric epithelial cells grew for about 3 months. ► The cultured cells differentiated into multi-units of the stomach. ► This culture method should be useful for elucidating the cause of gastric diseases. -- Abstract: Compared to the small intestine and colon, little is known about stem cells in the stomach because of a lack of specific stem cell markers and an in vitro system that allows long-term culture. Here we describe a long-term three-dimensional (3D) primary gastric culture system within the stem cell niche. Glandular stomach cells from neonatal mice cultured in collagen gel yielded expanding sphere-like structures for 3 months. The wall of the gastrospheres consisted of a highly polarized epithelial monolayer with an outer lining of myofibroblasts. The epithelial cells showed a tall columnar cell shape, basal round nuclei, and mucus-filled cytoplasm as well as expression of MUC5AC, indicating differentiation into gastric surface mucous cells. These cells demonstrated the features of fully differentiated gastric surface mucous cells such as microvilli, junctional complexes, and glycogen and secretory granules. Fewer than 1% of cultured epithelial cells differentiated into enteroendocrine cells. Active proliferation of the epithelial cells and many apoptotic cells in the inner lumen revealed the rapid cell turnover in gastrospheres in vitro. This method enables us to investigate the role of signaling between cell–cell and epithelial–mesenchymal interactions in an environment that is extremely similar to the in vivo environment.

  7. Optimization of Femtosecond Laser Polymerized Structural Niches to Control Mesenchymal Stromal Cell Fate in Culture

    Directory of Open Access Journals (Sweden)

    Manuela T. Raimondi

    2014-06-01

    Full Text Available We applied two-photon polymerization to fabricate 3D synthetic niches arranged in complex patterns to study the effect of mechano-topological parameters on morphology, renewal and differentiation of rat mesenchymal stromal cells. Niches were formed in a photoresist with low auto-fluorescence, which enabled the clear visualization of the fluorescence emission of the markers used for biological diagnostics within the internal niche structure. The niches were structurally stable in culture up to three weeks. At three weeks of expansion in the niches, cell density increased by almost 10-fold and was 67% greater than in monolayer culture. Evidence of lineage commitment was observed in monolayer culture surrounding the structural niches, and within cell aggregates, but not inside the niches. Thus, structural niches were able not only to direct stem cell homing and colony formation, but also to guide aggregate formation, providing increased surface-to-volume ratios and space for stem cells to adhere and renew, respectively.

  8. Tissue engineering a surrogate niche for metastatic cancer cells.

    Science.gov (United States)

    Seib, F Philipp; Berry, Janice E; Shiozawa, Yusuke; Taichman, Russell S; Kaplan, David L

    2015-05-01

    In breast and prostate cancer patients, the bone marrow is a preferred site of metastasis. We hypothesized that we could use tissue-engineering strategies to lure metastasizing cancer cells to tissue-engineered bone marrow. First, we generated highly porous 3D silk scaffolds that were biocompatible and amenable to bone morphogenetic protein 2 functionalization. Control and functionalized silk scaffolds were subcutaneously implanted in mice and bone marrow development was followed. Only functionalized scaffolds developed cancellous bone and red bone marrow, which appeared as early as two weeks post-implantation and further developed over the 16-week study period. This tissue-engineered bone marrow microenvironment could be readily manipulated in situ to understand the biology of bone metastasis. To test the ability of functionalized scaffolds to serve as a surrogate niche for metastasis, human breast cancer cells were injected into the mammary fat pads of mice. The treatment of animals with scaffolds had no significant effect on primary tumor growth. However, extensive metastasis was observed in functionalized scaffolds, and the highest levels for scaffolds that were in situ manipulated with receptor activator of nuclear factor kappa-B ligand (RANKL). We also applied this tissue-engineered bone marrow model in a prostate cancer and experimental metastasis setting. In summary, we were able to use tissue-engineered bone marrow to serve as a target or "trap" for metastasizing cancer cells. PMID:25771021

  9. Hematopoietic stem cell arrival triggers dynamic remodeling of the perivascular niche.

    Science.gov (United States)

    Tamplin, Owen J; Durand, Ellen M; Carr, Logan A; Childs, Sarah J; Hagedorn, Elliott J; Li, Pulin; Yzaguirre, Amanda D; Speck, Nancy A; Zon, Leonard I

    2015-01-15

    Hematopoietic stem and progenitor cells (HSPCs) can reconstitute and sustain the entire blood system. We generated a highly specific transgenic reporter of HSPCs in zebrafish. This allowed us to perform high-resolution live imaging on endogenous HSPCs not currently possible in mammalian bone marrow. Using this system, we have uncovered distinct interactions between single HSPCs and their niche. When an HSPC arrives in the perivascular niche, a group of endothelial cells remodel to form a surrounding pocket. This structure appears conserved in mouse fetal liver. Correlative light and electron microscopy revealed that endothelial cells surround a single HSPC attached to a single mesenchymal stromal cell. Live imaging showed that mesenchymal stromal cells anchor HSPCs and orient their divisions. A chemical genetic screen found that the compound lycorine promotes HSPC-niche interactions during development and ultimately expands the stem cell pool into adulthood. Our studies provide evidence for dynamic niche interactions upon stem cell colonization. PAPERFLICK: PMID:25594182

  10. Interactions between structural and chemical biomimetism in synthetic stem cell niches

    International Nuclear Information System (INIS)

    Advancements in understanding stem cell functions and differentiation are of key importance for the clinical success of stem-cell-based therapies. 3D structural niches fabricated by two-photon polymerization are a powerful platform for controlling stem cell growth and differentiation. In this paper, we investigate the possibility of further controlling stem cell fate by tuning the mechanical properties of such niches through coating with thin layers of biomimetic hyaluronan-based and gelatin-based hydrogels. We first assess the biocompatibility of chemical coatings and then study the interactions between structural and chemical biomimetism on the response of MSCs in terms of proliferation and differentiation. We observed a clear effect of the hydrogel coating on otherwise identical 3D scaffolds. In particular, in gelatin-coated niches we observed a stronger metabolic activity and commitment toward the osteo-chondral lineage with respect to hyaluronan-coated niches. Conversely, a reduction in the homing effect was observed in all the coated niches, especially in gelatin-coated niches. This study demonstrates the feasibility of controlling independently different mechanical cues, in bioengineered stem cell niches, i.e. the 3D scaffold geometry and the surface stiffness. This will allow, on the one hand, understanding their specific role in stem cell proliferation and differentiation and, on the other hand, finely tuning their synergistic effect. (paper)

  11. Escargot Restricts Niche Cell to Stem Cell Conversion in the Drosophila Testis

    Directory of Open Access Journals (Sweden)

    Justin Voog

    2014-05-01

    Full Text Available Stem cells reside within specialized microenvironments, or niches, that control many aspects of stem cell behavior. Somatic hub cells in the Drosophila testis regulate the behavior of cyst stem cells (CySCs and germline stem cells (GSCs and are a primary component of the testis stem cell niche. The shutoff (shof mutation, characterized by premature loss of GSCs and CySCs, was mapped to a locus encoding the evolutionarily conserved transcription factor Escargot (Esg. Hub cells depleted of Esg acquire CySC characteristics and differentiate as cyst cells, resulting in complete loss of hub cells and eventually CySCs and GSCs, similar to the shof mutant phenotype. We identified Esg-interacting proteins and demonstrate an interaction between Esg and the corepressor C-terminal binding protein (CtBP, which was also required for maintenance of hub cell fate. Our results indicate that niche cells can acquire stem cell properties upon removal of a single transcription factor in vivo.

  12. Escargot restricts niche cell to stem cell conversion in the Drosophila testis.

    Science.gov (United States)

    Voog, Justin; Sandall, Sharsti L; Hime, Gary R; Resende, Luís Pedro F; Loza-Coll, Mariano; Aslanian, Aaron; Yates, John R; Hunter, Tony; Fuller, Margaret T; Jones, D Leanne

    2014-05-01

    Stem cells reside within specialized microenvironments, or niches, that control many aspects of stem cell behavior. Somatic hub cells in the Drosophila testis regulate the behavior of cyst stem cells (CySCs) and germline stem cells (GSCs) and are a primary component of the testis stem cell niche. The shutoff (shof) mutation, characterized by premature loss of GSCs and CySCs, was mapped to a locus encoding the evolutionarily conserved transcription factor Escargot (Esg). Hub cells depleted of Esg acquire CySC characteristics and differentiate as cyst cells, resulting in complete loss of hub cells and eventually CySCs and GSCs, similar to the shof mutant phenotype. We identified Esg-interacting proteins and demonstrate an interaction between Esg and the corepressor C-terminal binding protein (CtBP), which was also required for maintenance of hub cell fate. Our results indicate that niche cells can acquire stem cell properties upon removal of a single transcription factor in vivo. PMID:24794442

  13. A causal relation between bioluminescence and oxygen to quantify the cell niche

    OpenAIRE

    Lambrechts, Dennis; Roeffaers, Maarten; Goossens, Karel; Hofkens, Johan; Vande Velde, Greetje; Van de Putte, Tom; Schrooten, Jan; Van Oosterwyck, Hans

    2014-01-01

    Bioluminescence imaging assays have become a widely integrated technique to quantify effectiveness of cell-based therapies by monitoring fate and survival of transplanted cells. To date these assays are still largely qualitative and often erroneous due to the complexity and dynamics of local micro-environments (niches) in which the cells reside. Here, we report, using a combined experimental and computational approach, on oxygen that besides being a critical niche component responsible for ce...

  14. Mesenchymal and haematopoietic stem cells form a unique bone marrow niche

    OpenAIRE

    Méndez-Ferrer, Simón; Michurina, Tatyana V.; Ferraro, Francesca; Amin R Mazloom; MacArthur, Ben D; Lira, Sergio A.; Scadden, David T.; Ma’ayan, Avi; Enikolopov, Grigori N.; Frenette, Paul S.

    2010-01-01

    The cellular constituents forming the haematopoietic stem cell (HSC) niche in the bone marrow are unclear, with studies implicating osteoblasts, endothelial and perivascular cells. Here we demonstrate that mesenchymal stem cells (MSCs), identified using nestin expression, constitute an essential HSC niche component. Nestin+ MSCs contain all the bone-marrow colony-forming-unit fibroblastic activity and can be propagated as non-adherent ‘mesenspheres’ that can self-renew and expand in serial tr...

  15. The Hippo Pathway Regulates Homeostatic Growth of Stem Cell Niche Precursors in the Drosophila Ovary

    OpenAIRE

    Sarikaya, Didem P.; Extavour, Cassandra G.

    2015-01-01

    The Hippo pathway regulates organ size, stem cell proliferation and tumorigenesis in adult organs. Whether the Hippo pathway influences establishment of stem cell niche size to accommodate changes in organ size, however, has received little attention. Here, we ask whether Hippo signaling influences the number of stem cell niches that are established during development of the Drosophila larval ovary, and whether it interacts with the same or different effector signaling pathways in different c...

  16. Mobilization of hematopoietic stem cells from the bone marrow niche to the blood compartment

    OpenAIRE

    Hoggatt, Jonathan; Pelus, Louis M.

    2011-01-01

    The vast majority of hematopoietic stem cells (HSCs) reside in specialized niches within the bone marrow during steady state, maintaining lifelong blood cell production. A small number of HSCs normally traffic throughout the body; however, exogenous stimuli can enhance their release from the niche and entry into the peripheral circulation. This process, termed mobilization, has become the primary means to acquire a stem cell graft for hematopoietic transplant at most transplant centers. Curre...

  17. Paracrine Molecules of Mesenchymal Stem Cells for Hematopoietic Stem Cell Niche

    OpenAIRE

    Tian Li; Yaojiong Wu

    2011-01-01

    Hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs) are both adult stem cells residing in the bone marrow. MSCs interact with HSCs, they stimulate and enhance the proliferation of HSCs by secreting regulatory molecules and cytokines, providing a specialized microenvironment for controlling the process of hematopoiesis. In this paper we discuss how MSCs contribute to HSC niche, maintain the stemness and proliferation of HSCs, and support HSC transplantation.

  18. Are neural crest stem cells the missing link between hematopoietic and neurogenic niches?

    Directory of Open Access Journals (Sweden)

    Virginie Neirinckx

    2015-06-01

    Full Text Available Hematopoietic niches are defined as cellular and molecular microenvironments that regulate hematopoietic stem cell (HSC function together with stem cell autonomous mechanisms. Many different cell types have been characterized as contributors to the formation of HSC niches, such as osteoblasts, endothelial cells, Schwann cells, and mesenchymal progenitors. These mesenchymal progenitors have themselves been classified as CXC chemokine ligand (CXCL12-abundant reticular (CAR cells, stem cell factor expressing cells, or nestin-positive mesenchymal stem cells (MSCs, which have been recently identified as neural crest-derived cells (NCSCs. Together, these cells are spatially associated with HSCs and believed to provide appropriate microenvironments for HSC self-renewal, differentiation, mobilization and hibernation both by cell-to-cell contact and soluble factors. Interestingly, it appears that regulatory pathways governing the hematopoietic niche homeostasis are operating in the neurogenic niche as well. Therefore, this review paper aims to compare both the regulation of hematopoietic and neurogenic niches, in order to highlight the role of NCSCs and nervous system components in the development and the regulation of the hematopoietic system.

  19. Are neural crest stem cells the missing link between hematopoietic and neurogenic niches?

    Science.gov (United States)

    Coste, Cécile; Neirinckx, Virginie; Gothot, André; Wislet, Sabine; Rogister, Bernard

    2015-01-01

    Hematopoietic niches are defined as cellular and molecular microenvironments that regulate hematopoietic stem cell (HSC) function together with stem cell autonomous mechanisms. Many different cell types have been characterized as contributors to the formation of HSC niches, such as osteoblasts, endothelial cells, Schwann cells, and mesenchymal progenitors. These mesenchymal progenitors have themselves been classified as CXC chemokine ligand (CXCL) 12-abundant reticular (CAR) cells, stem cell factor expressing cells, or nestin-positive mesenchymal stem cells (MSCs), which have been recently identified as neural crest-derived cells (NCSCs). Together, these cells are spatially associated with HSCs and believed to provide appropriate microenvironments for HSC self-renewal, differentiation, mobilization and hibernation both by cell-cell contact and soluble factors. Interestingly, it appears that regulatory pathways governing the hematopoietic niche homeostasis are operating in the neurogenic niche as well. Therefore, this review paper aims to compare both the regulation of hematopoietic and neurogenic niches, in order to highlight the role of NCSCs and nervous system components in the development and the regulation of the hematopoietic system. PMID:26136659

  20. Brain micro-ecologies: neural stem cell niches in the adult mammalian brain

    OpenAIRE

    Riquelme, Patricio A; Drapeau, Elodie; Doetsch, Fiona

    2007-01-01

    Neurogenesis persists in two germinal regions in the adult mammalian brain, the subventricular zone of the lateral ventricles and the subgranular zone in the hippocampal formation. Within these two neurogenic niches, specialized astrocytes are neural stem cells, capable of self-renewing and generating neurons and glia. Cues within the niche, from cell–cell interactions to diffusible factors, are spatially and temporally coordinated to regulate proliferation and neurogenesis, ultimately affect...

  1. Finding missing interactions of the Arabidopsis thaliana root stem cell niche gene regulatory network

    Directory of Open Access Journals (Sweden)

    Eugenio eAzpeitia

    2013-04-01

    Full Text Available AbstractOver the last few decades, the Arabidopsis thaliana root stem cell niche has become a model system for the study of plant development and the stem cell niche. Currently, many of the molecular mechanisms involved in root stem cell niche maintenance and development have been described. A few years ago, we published a gene regulatory network model integrating this information. This model suggested that there were missing components or interactions. Upon updating the model, the observed stable gene configurations of the root stem cell niche could not be recovered, indicating that there are additional missing components or interactions in the model. In fact, due to the lack of experimental data, gene regulatory networks inferred from published data are usually incomplete. However, predicting the location and nature of the missing data is a not trivial task. Here, we propose a set of procedures for detecting and predicting missing interactions in Boolean networks. We used these procedures to predict putative missing interactions in the A. thaliana root stem cell niche network model. Using our approach, we identified three necessary interactions to recover the reported gene activation configurations that have been experimentally uncovered for the different cell types within the root stem cell niche: 1 a regulation of PHABULOSA to restrict its expression domain to the vascular cells, 2 a self-regulation of WOX5, possibly by an indirect mechanism through the auxin signalling pathway and 3 a positive regulation of JACKDAW by MAGPIE. The procedures proposed here greatly reduce the number of possible Boolean functions that are biologically meaningful and experimentally testable and that do not contradict previous data. We believe that these procedures can be used on any Boolean network. However, because the procedures were designed for the specific case of the root stem cell niche, formal demonstrations of the procedures should be shown in future

  2. The FOXD1 lineage of kidney perivascular cells and myofibroblasts: functions and responses to injury

    OpenAIRE

    Gomez, Ivan G.; Duffield, Jeremy S.

    2014-01-01

    Recent studies have identified a poorly appreciated yet extensive population of perivascular mesenchymal cells in the kidney, which are derived from metanephric mesenchyme progenitor cells during nephrogenesis at which time they express the transcription factor FOXD1. Some studies have called these resident fibroblasts, whereas others have called them pericytes. Regardless of nomenclature, many are partially integrated into the capillary basement membrane and contribute in important ways to t...

  3. Miofibroblastos e sua relação com o carcinoma de células escamosas oral Myofibroblasts and their relationship with oral squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Priscilla Suassuna Carneiro Lúcio

    2013-02-01

    Full Text Available Os miofibroblastos são células especializadas que exibem um fenótipo híbrido, com características de fibroblastos e células musculares lisas. Devido sua habilidade contrátil e capacidade de síntese de componentes da matriz extracelular, citocinas, proteases e fatores pró-angiogênicos, os miofibroblastos têm sido implicados na patogênese de doenças fibrocontráteis e na progressão de diversos tumores, incluindo o carcinoma de células escamosas (CCE oral. OBJETIVO: Fazer uma revisão da literatura sobre a origem dos miofibroblastos, seus principais aspectos morfofisiológicos e imuno-histoquímicos, assim como discutir sua relação com o CCE oral. MÉTODO: Realizou-se uma busca eletrônica na base de dados PubMed, selecionando os principais artigos da literatura em língua inglesa relacionados ao tema, publicados entre janeiro de 1991 e dezembro de 2011. CONCLUSÃO: Os miofibroblastos representam um componente importante do estroma de CCE orais, embora não estejam presentes em todos os casos desta neoplasia. A presença abundante destas células pode estar associada com a recorrência local da doença e diminuição da sobrevida dos pacientes. No entanto, em virtude do número relativamente limitado de estudos sobre o assunto, pesquisas ainda são necessárias para esclarecer os mecanismos moleculares pelos quais os miofibroblastos são capazes de influenciar no comportamento biológico do CCE oral.Myofibroblasts are hybrid-phenotype differentiated cells in between fibroblasts and smooth muscle cells. Due to their contractile features and ability to synthesize extracellular matrix components, cytokines, proteases, and proangiogenic factors, myofibroblasts have been implicated in the pathogenesis of fibrocontractive diseases and in the progression of many tumors, including oral squamous cell carcinoma (SCC. OBJECTIVE: To perform a literature review on the origin of myofibroblasts, their main morpho-physiological and

  4. Inflammatory myofibroblastic tumor of the urinary bladder

    OpenAIRE

    Yagnik Vipul; Chadha Amit; Chaudhari Sanjay; Patel Keyuri

    2010-01-01

    Inflammatory myofibroblastic tumor (IMT) of bladder is an uncommon benign tumor of bladder, which is of unknown neoplastic potential, characterized by spindle cell proliferation with characteristic fibroinflammatory and pseudosarcomatous appearance. Essential criteria for the diagnosis of IMT are: spindle myoepithelial cell proliferation and lymphocytic infiltrate. Complete surgical resection is the treatment of choice.

  5. Identification of hepatic niche harboring human acute lymphoblastic leukemic cells via the SDF-1/CXCR4 axis.

    Directory of Open Access Journals (Sweden)

    Itaru Kato

    Full Text Available In acute lymphoblastic leukemia (ALL patients, the bone marrow niche is widely known to be an important element of treatment response and relapse. Furthermore, a characteristic liver pathology observed in ALL patients implies that the hepatic microenvironment provides an extramedullary niche for leukemic cells. However, it remains unclear whether the liver actually provides a specific niche. The mechanism underlying this pathology is also poorly understood. Here, to answer these questions, we reconstituted the histopathology of leukemic liver by using patients-derived primary ALL cells into NOD/SCID/Yc (null mice. The liver pathology in this model was similar to that observed in the patients. By using this model, we clearly demonstrated that bile duct epithelial cells form a hepatic niche that supports infiltration and proliferation of ALL cells in the liver. Furthermore, we showed that functions of the niche are maintained by the SDF-1/CXCR4 axis, proposing a novel therapeutic approach targeting the extramedullary niche by inhibition of the SDF-1/CXCR4 axis. In conclusion, we demonstrated that the liver dissemination of leukemia is not due to nonselective infiltration, but rather systematic invasion and proliferation of leukemic cells in hepatic niche. Although the contribution of SDF-1/CXCR4 axis is reported in some cancer cells or leukemic niches such as bone marrow, we demonstrated that this axis works even in the extramedullary niche of leukemic cells. Our findings form the basis for therapeutic approaches that target the extramedullary niche by inhibiting the SDF-1/CXCR4 axis.

  6. NFIB is a governor of epithelial-melanocyte stem cell behaviour in a shared niche.

    Science.gov (United States)

    Chang, Chiung-Ying; Pasolli, H Amalia; Giannopoulou, Eugenia G; Guasch, Géraldine; Gronostajski, Richard M; Elemento, Olivier; Fuchs, Elaine

    2013-03-01

    Adult stem cells reside in specialized niches where they receive environmental cues to maintain tissue homeostasis. In mammals, the stem cell niche within hair follicles is home to epithelial hair follicle stem cells and melanocyte stem cells, which sustain cyclical bouts of hair regeneration and pigmentation. To generate pigmented hairs, synchrony is achieved such that upon initiation of a new hair cycle, stem cells of each type activate lineage commitment. Dissecting the inter-stem-cell crosstalk governing this intricate coordination has been difficult, because mutations affecting one lineage often affect the other. Here we identify transcription factor NFIB as an unanticipated coordinator of stem cell behaviour. Hair follicle stem-cell-specific conditional targeting of Nfib in mice uncouples stem cell synchrony. Remarkably, this happens not by perturbing hair cycle and follicle architecture, but rather by promoting melanocyte stem cell proliferation and differentiation. The early production of melanin is restricted to melanocyte stem cells at the niche base. Melanocyte stem cells more distant from the dermal papilla are unscathed, thereby preventing hair greying typical of melanocyte stem cell differentiation mutants. Furthermore, we pinpoint KIT-ligand as a dermal papilla signal promoting melanocyte stem cell differentiation. Additionally, through chromatin-immunoprecipitation with high-throughput-sequencing and transcriptional profiling, we identify endothelin 2 (Edn2) as an NFIB target aberrantly activated in NFIB-deficient hair follicle stem cells. Ectopically induced Edn2 recapitulates NFIB-deficient phenotypes in wild-type mice. Conversely, endothelin receptor antagonists and/or KIT blocking antibodies prevent precocious melanocyte stem cell differentiation in the NFIB-deficient niche. Our findings reveal how melanocyte and hair follicle stem cell behaviours maintain reliance upon cooperative factors within the niche, and how this can be uncoupled in

  7. Culture Model of Rat Portal Myofibroblasts.

    Science.gov (United States)

    El Mourabit, Haquima; Loeuillard, Emilien; Lemoinne, Sara; Cadoret, Axelle; Housset, Chantal

    2016-01-01

    Myofibroblasts are matrix-producing cells with contractile properties, usually characterized by de novo expression of alpha-smooth muscle actin, that arise in fibrotic diseases. Hepatic stellate cells (HSCs), known as perisinusoidal cells containing auto-fluorescent vitamin A, are the major although not exclusive source of myofibroblasts in the injured liver. Portal myofibroblasts (PMFs) have been defined as liver myofibroblasts derived from cells that are distinct from HSCs and located in the portal tract. Here, we describe the protocol we have established to obtain rat PMFs in culture. In this method, the biliary tree is (i) separated from the liver parenchyma by in situ enzymatic perfusion of the liver, (ii) minced and further digested in vitro, until bile duct segments are isolated by sequential filtration. Bile duct isolates free of HSC contaminants, form small cell clusters, which initially comprise a large majority of epithelial cells. In culture conditions (fetal bovine serum) that provide a growth advantage to mesenchymal cells over epithelial cells, the epithelial cells die and detach from the substrate, while spindle-shaped cells outgrow from the periphery of the cell clusters, as shown by video-microscopy. These cells are highly proliferative and after 4-5 days, the culture is composed exclusively of fully differentiated myofibroblasts, which express alpha-smooth muscle actin and collagen 1, and secrete abundant collagen. We found no evidence for epithelial-mesenchymal transition, i.e., no co-expression of alpha-smooth muscle actin and cytokeratin at any stage, while cytokeratin becomes undetectable in the confluent cells. PMFs obtained by this method express the genes that were previously reported to be overexpressed in non-HSC or portal fibroblast-derived liver myofibroblasts as compared to HSC-derived myofibroblasts, including the most discriminant, collagen 15, fibulin 2, and Thy-1. After one passage, PMFs retain the same phenotypic features as in

  8. Culture Model of Rat Portal Myofibroblasts

    Science.gov (United States)

    El Mourabit, Haquima; Loeuillard, Emilien; Lemoinne, Sara; Cadoret, Axelle; Housset, Chantal

    2016-01-01

    Myofibroblasts are matrix-producing cells with contractile properties, usually characterized by de novo expression of alpha-smooth muscle actin, that arise in fibrotic diseases. Hepatic stellate cells (HSCs), known as perisinusoidal cells containing auto-fluorescent vitamin A, are the major although not exclusive source of myofibroblasts in the injured liver. Portal myofibroblasts (PMFs) have been defined as liver myofibroblasts derived from cells that are distinct from HSCs and located in the portal tract. Here, we describe the protocol we have established to obtain rat PMFs in culture. In this method, the biliary tree is (i) separated from the liver parenchyma by in situ enzymatic perfusion of the liver, (ii) minced and further digested in vitro, until bile duct segments are isolated by sequential filtration. Bile duct isolates free of HSC contaminants, form small cell clusters, which initially comprise a large majority of epithelial cells. In culture conditions (fetal bovine serum) that provide a growth advantage to mesenchymal cells over epithelial cells, the epithelial cells die and detach from the substrate, while spindle-shaped cells outgrow from the periphery of the cell clusters, as shown by video-microscopy. These cells are highly proliferative and after 4–5 days, the culture is composed exclusively of fully differentiated myofibroblasts, which express alpha-smooth muscle actin and collagen 1, and secrete abundant collagen. We found no evidence for epithelial-mesenchymal transition, i.e., no co-expression of alpha-smooth muscle actin and cytokeratin at any stage, while cytokeratin becomes undetectable in the confluent cells. PMFs obtained by this method express the genes that were previously reported to be overexpressed in non-HSC or portal fibroblast-derived liver myofibroblasts as compared to HSC-derived myofibroblasts, including the most discriminant, collagen 15, fibulin 2, and Thy-1. After one passage, PMFs retain the same phenotypic features as in

  9. Prostate cancer cells metastasize to the hematopoietic stem cell niche in bone

    Institute of Scientific and Technical Information of China (English)

    Evan T Keller

    2011-01-01

    @@ The majority of men with advanced prostate cancer develop bone metastases as opposed to metastases at other sites.1 It has been unclear why prostate cancer selectively metastasizes to and proliferates in bone.Recently, Shiozawa et al.Delineated a mechanism that may account for the establishment of prostate cancer in bone.2 Specifically, they identified that prostate cancer cells compete with hematopoietic stem cells (HSC) for the osteoblast in the HSC niche of the bone.Defining the mechanisms through which prostate cancer cells establish themselves in bone is critical towards developing effective therapeutic strategies to prevent or target bone metastases.

  10. An epidermis-driven mechanism positions and scales stem cell niches in plants

    Science.gov (United States)

    Gruel, Jérémy; Landrein, Benoit; Tarr, Paul; Schuster, Christoph; Refahi, Yassin; Sampathkumar, Arun; Hamant, Olivier; Meyerowitz, Elliot M.; Jönsson, Henrik

    2016-01-01

    How molecular patterning scales to organ size is highly debated in developmental biology. We explore this question for the characteristic gene expression domains of the plant stem cell niche residing in the shoot apical meristem. We show that a combination of signals originating from the epidermal cell layer can correctly pattern the key gene expression domains and notably leads to adaptive scaling of these domains to the size of the tissue. Using live imaging, we experimentally confirm this prediction. The identified mechanism is also sufficient to explain de novo stem cell niches in emerging flowers. Our findings suggest that the deformation of the tissue transposes meristem geometry into an instructive scaling and positional input for the apical plant stem cell niche.

  11. An epidermis-driven mechanism positions and scales stem cell niches in plants.

    Science.gov (United States)

    Gruel, Jérémy; Landrein, Benoit; Tarr, Paul; Schuster, Christoph; Refahi, Yassin; Sampathkumar, Arun; Hamant, Olivier; Meyerowitz, Elliot M; Jönsson, Henrik

    2016-01-01

    How molecular patterning scales to organ size is highly debated in developmental biology. We explore this question for the characteristic gene expression domains of the plant stem cell niche residing in the shoot apical meristem. We show that a combination of signals originating from the epidermal cell layer can correctly pattern the key gene expression domains and notably leads to adaptive scaling of these domains to the size of the tissue. Using live imaging, we experimentally confirm this prediction. The identified mechanism is also sufficient to explain de novo stem cell niches in emerging flowers. Our findings suggest that the deformation of the tissue transposes meristem geometry into an instructive scaling and positional input for the apical plant stem cell niche. PMID:27152324

  12. Myofibroblastic cell activation and neovascularization predict native liver survival and development of esophageal varices in biliary atresia

    Science.gov (United States)

    Suominen, Janne S; Lampela, Hanna; Heikkilä, Päivi; Lohi, Jouko; Jalanko, Hannu; Pakarinen, Mikko P

    2014-01-01

    myofibroblastic cell activation, fibrogenesis and neovascularization are enhanced in BA, progress with increasing PE age and relate to native liver survival and development of esophageal varices. PMID:24696612

  13. Redox and Metabolic Regulation of Stem/Progenitor Cells and Their Niche

    OpenAIRE

    Ushio-Fukai, Masuko; Rehman, Jalees

    2014-01-01

    Stem cells are defined as cells that have the capacity to self-renew and exhibit multipotency or pluripotency, whereas progenitor cells are committed to selected lineages but retain their self-renewal capacity. The stem or progenitor cell niche refers to the microenvironment of the regenerative cells in the bone marrow (BM) or other tissues such as the heart. It can regulate self-renewal, differentiation, migration, and proliferation of regenerative stem/progenitor cells. The precise regulato...

  14. Inhibition of the K+ channel K(Ca3.1 reduces TGF-β1-induced premature senescence, myofibroblast phenotype transition and proliferation of mesangial cells.

    Directory of Open Access Journals (Sweden)

    Rong-Guo Fu

    Full Text Available OBJECTIVE: K(Ca3.1 channel participates in many important cellular functions. This study planned to investigate the potential involvement of K(Ca3.1 channel in premature senescence, myofibroblast phenotype transition and proliferation of mesangial cells. METHODS & MATERIALS: Rat mesangial cells were cultured together with TGF-β1 (2 ng/ml and TGF-β1 (2 ng/ml + TRAM-34 (16 nM separately for specified times from 0 min to 60 min. The cells without treatment served as controls. The location of K(Ca3.1 channels in mesangial cells was determined with Confocal laser microscope, the cell cycle of mesangial cells was assessed with flow cytometry, the protein and mRNA expression of K(Ca3.1, α-smooth muscle actin (α-SMA and fibroblast-specific protein-1 (FSP-1 were detected with Western blot and RT-PCR. One-way analysis of variance (ANOVA and Student-Newman-Keuls-q test (SNK-q were used to do statistical analysis. Statistical significance was considered at P<0.05. RESULTS: Kca3.1 channels were located in the cell membranes and/or in the cytoplasm of mesangial cells. The percentage of cells in G0-G1 phase and the expression of K(ca3.1, α-SMA and FSP-1 were elevated under the induction of TGF-β1 when compared to the control and decreased under the induction of TGF-β1+TRAM-34 when compared to the TGF-β1 induced (P<0.05 or P<0.01. CONCLUSION: Targeted disruption of K(Ca3.1 inhibits TGF-β1-induced premature aging, myofibroblast-like phenotype transdifferentiation and proliferation of mesangial cells.

  15. Classic and novel stem cell niches in brain homeostasis and repair.

    Science.gov (United States)

    Lin, Ruihe; Iacovitti, Lorraine

    2015-12-01

    Neural stem cells (NSCs) critical for the continued production of new neurons and glia are sequestered in distinct areas of the brain called stem cell niches. Until recently, only two forebrain sites, the subventricular zone (SVZ) of the anterolateral ventricle and the subgranular zone (SGZ) of the hippocampus, have been recognized adult stem cell niches (Alvarez-Buylla and Lim, 2004; Doetsch et al., 1999a, 1999b; Doetsch, 2003a, 2003b; Lie et al., 2004; Ming and Song, 2005). Nonetheless, the last decade has been witness to a growing literature suggesting that in fact the adult brain contains stem cell niches along the entire extent of the ventricular system. These niches are capable of widespread neurogenesis and gliogenesis, particularly after injury (Barnabé-Heider et al., 2010; Carlén et al., 2009; Decimo et al., 2012; Lin et al., 2015; Lindvall and Kokaia, 2008; Robins et al., 2013) or other inductive stimuli (Bennett et al., 2009; Cunningham et al., 2012; Decimo et al., 2011; Kokoeva et al., 2007, 2005; Lee et al., 2012a, 2012b; Migaud et al., 2010; Pencea et al., 2001b; Sanin et al., 2013; Suh et al., 2007; Sundholm-Peters et al., 2004; Xu et al., 2005; Zhang et al., 2007). This review focuses on the role of these novel and classic brain niches in maintaining adult neurogenesis and gliogenesis in response to normal physiological and injury-related pathological cues. This article is part of a Special Issue entitled SI: Neuroprotection. PMID:25931262

  16. Characterization of multiciliated ependymal cells that emerge in the neurogenic niche of the aged zebrafish brain.

    Science.gov (United States)

    Ogino, Takashi; Sawada, Masato; Takase, Hiroshi; Nakai, Chiemi; Herranz-Pérez, Vicente; Cebrián-Silla, Arantxa; Kaneko, Naoko; García-Verdugo, José Manuel; Sawamoto, Kazunobu

    2016-10-15

    In mammals, ventricular walls of the developing brain maintain a neurogenic niche, in which radial glial cells act as neural stem cells (NSCs) and generate new neurons in the embryo. In the adult brain, the neurogenic niche is maintained in the ventricular-subventricular zone (V-SVZ) of the lateral wall of lateral ventricles and the hippocampal dentate gyrus. In the neonatal V-SVZ, radial glial cells transform into astrocytic postnatal NSCs and multiciliated ependymal cells. On the other hand, in zebrafish, radial glial cells continue to cover the surface of the adult telencephalic ventricle and maintain a higher neurogenic potential in the adult brain. However, the cell composition of the neurogenic niche of the aged zebrafish brain has not been investigated. Here we show that multiciliated ependymal cells emerge in the neurogenic niche of the aged zebrafish telencephalon. These multiciliated cells appear predominantly in the dorsal part of the ventral telencephalic ventricular zone, which also contains clusters of migrating new neurons. Scanning electron microscopy and live imaging analyses indicated that these multiple cilia beat coordinately and generate constant fluid flow within the ventral telencephalic ventricle. Analysis of the cell composition by transmission electron microscopy revealed that the neurogenic niche in the aged zebrafish contains different types of cells, with ultrastructures similar to those of ependymal cells, transit-amplifying cells, and migrating new neurons in postnatal mice. These data suggest that the transformation capacity of radial glial cells is conserved but that its timing is different between fish and mice. J. Comp. Neurol. 524:2982-2992, 2016. © 2016 Wiley Periodicals, Inc. PMID:26991819

  17. Notch signaling mediates the age-associated decrease in adhesion of germline stem cells to the niche.

    Directory of Open Access Journals (Sweden)

    Chen-Yuan Tseng

    2014-12-01

    Full Text Available Stem cells have an innate ability to occupy their stem cell niche, which in turn, is optimized to house stem cells. Organ aging is associated with reduced stem cell occupancy in the niche, but the mechanisms involved are poorly understood. Here, we report that Notch signaling is increased with age in Drosophila female germline stem cells (GSCs, and this results in their removal from the niche. Clonal analysis revealed that GSCs with low levels of Notch signaling exhibit increased adhesiveness to the niche, thereby out-competing their neighbors with higher levels of Notch; adhesiveness is altered through regulation of E-cadherin expression. Experimental enhancement of Notch signaling in GSCs hastens their age-dependent loss from the niche, and such loss is at least partially mediated by Sex lethal. However, disruption of Notch signaling in GSCs does not delay GSC loss during aging, and nor does it affect BMP signaling, which promotes self-renewal of GSCs. Finally, we show that in contrast to GSCs, Notch activation in the niche (which maintains niche integrity, and thus mediates GSC retention is reduced with age, indicating that Notch signaling regulates GSC niche occupancy both intrinsically and extrinsically. Our findings expose a novel role of Notch signaling in controlling GSC-niche adhesion in response to aging, and are also of relevance to metastatic cancer cells, in which Notch signaling suppresses cell adhesion.

  18. Notch signaling mediates the age-associated decrease in adhesion of germline stem cells to the niche.

    Science.gov (United States)

    Tseng, Chen-Yuan; Kao, Shih-Han; Wan, Chih-Ling; Cho, Yueh; Tung, Shu-Yun; Hsu, Hwei-Jan

    2014-12-01

    Stem cells have an innate ability to occupy their stem cell niche, which in turn, is optimized to house stem cells. Organ aging is associated with reduced stem cell occupancy in the niche, but the mechanisms involved are poorly understood. Here, we report that Notch signaling is increased with age in Drosophila female germline stem cells (GSCs), and this results in their removal from the niche. Clonal analysis revealed that GSCs with low levels of Notch signaling exhibit increased adhesiveness to the niche, thereby out-competing their neighbors with higher levels of Notch; adhesiveness is altered through regulation of E-cadherin expression. Experimental enhancement of Notch signaling in GSCs hastens their age-dependent loss from the niche, and such loss is at least partially mediated by Sex lethal. However, disruption of Notch signaling in GSCs does not delay GSC loss during aging, and nor does it affect BMP signaling, which promotes self-renewal of GSCs. Finally, we show that in contrast to GSCs, Notch activation in the niche (which maintains niche integrity, and thus mediates GSC retention) is reduced with age, indicating that Notch signaling regulates GSC niche occupancy both intrinsically and extrinsically. Our findings expose a novel role of Notch signaling in controlling GSC-niche adhesion in response to aging, and are also of relevance to metastatic cancer cells, in which Notch signaling suppresses cell adhesion. PMID:25521289

  19. The canine hepatic progenitor cell niche : molecular characterisation in health and disease

    NARCIS (Netherlands)

    Kruitwagen, H S; Spee, B; Viebahn, C S; Venema, H B; Penning, L C; Grinwis, G C M; Favier, R P; van den Ingh, T S G A M; Rothuizen, J; Schotanus, B A

    2014-01-01

    Hepatic progenitor cells (HPCs) are an adult stem cell compartment in the liver that contributes to liver regeneration when replication of mature hepatocytes is insufficient. In this study, laser microdissection was used to isolate HPC niches from the livers of healthy dogs and dogs with lobular dis

  20. Reversible neural stem cell niche dysfunction in a model of multiple sclerosis

    DEFF Research Database (Denmark)

    Rasmussen, Stine; Imitola, Jaime; Ayuso-Sacido, Angel;

    2011-01-01

    OBJECTIVE: The subventricular zone (SVZ) of the brain constitutes a niche for neural stem and progenitor cells that can initiate repair after central nervous system (CNS) injury. In a relapsing-remitting model of experimental autoimmune encephalomyelitis (EAE), the neural stem cells (NSCs) become...

  1. The mechanical environment modulates intracellular calcium oscillation activities of myofibroblasts.

    Directory of Open Access Journals (Sweden)

    Charles Godbout

    Full Text Available Myofibroblast contraction is fundamental in the excessive tissue remodeling that is characteristic of fibrotic tissue contractures. Tissue remodeling during development of fibrosis leads to gradually increasing stiffness of the extracellular matrix. We propose that this increased stiffness positively feeds back on the contractile activities of myofibroblasts. We have previously shown that cycles of contraction directly correlate with periodic intracellular calcium oscillations in cultured myofibroblasts. We analyze cytosolic calcium dynamics using fluorescent calcium indicators to evaluate the possible impact of mechanical stress on myofibroblast contractile activity. To modulate extracellular mechanics, we seeded primary rat subcutaneous myofibroblasts on silicone substrates and into collagen gels of different elastic modulus. We modulated cell stress by cell growth on differently adhesive culture substrates, by restricting cell spreading area on micro-printed adhesive islands, and depolymerizing actin with Cytochalasin D. In general, calcium oscillation frequencies in myofibroblasts increased with increasing mechanical challenge. These results provide new insight on how changing mechanical conditions for myofibroblasts are encoded in calcium oscillations and possibly explain how reparative cells adapt their contractile behavior to the stresses occurring in normal and pathological tissue repair.

  2. The Drosophila BCL6 homolog ken and barbie promotes somatic stem cell self-renewal in the testis niche

    OpenAIRE

    Issigonis, Melanie; Matunis, Erika

    2012-01-01

    Stem cells sustain tissue regeneration by their remarkable ability to replenish the stem cell pool and to generate differentiating progeny. Signals from local microenvironments, or niches, control stem cell behavior. In the Drosophila testis, a group of somatic support cells called the hub creates a stem cell niche by locally activating the Janus Kinase-Signal Transducer and Activator of Transcription (JAK-STAT) pathway in two adjacent types of stem cells: germline stem cells (GSCs) and somat...

  3. Mesenchymal morphogenesis of embryonic stem cells dynamically modulates the biophysical microtissue niche

    OpenAIRE

    Kinney, Melissa A.; Rabbia Saeed; McDevitt, Todd C.

    2014-01-01

    Stem cell fate and function are dynamically modulated by the interdependent relationships between biochemical and biophysical signals constituting the local 3D microenvironment. While approaches to recapitulate the stem cell niche have been explored for directing stem cell differentiation, a quantitative relationship between embryonic stem cell (ESC) morphogenesis and intrinsic biophysical cues within three-dimensional microtissues has not been established. In this study, we demonstrate that ...

  4. Intestinal subepithelial myofibroblasts support in vitro and in vivo growth of human small intestinal epithelium.

    Directory of Open Access Journals (Sweden)

    Nicholas Lahar

    Full Text Available The intestinal crypt-niche interaction is thought to be essential to the function, maintenance, and proliferation of progenitor stem cells found at the bases of intestinal crypts. These stem cells are constantly renewing the intestinal epithelium by sending differentiated cells from the base of the crypts of Lieberkühn to the villus tips where they slough off into the intestinal lumen. The intestinal niche consists of various cell types, extracellular matrix, and growth factors and surrounds the intestinal progenitor cells. There have recently been advances in the understanding of the interactions that regulate the behavior of the intestinal epithelium and there is great interest in methods for isolating and expanding viable intestinal epithelium. However, there is no method to maintain primary human small intestinal epithelium in culture over a prolonged period of time. Similarly no method has been published that describes isolation and support of human intestinal epithelium in an in vivo model. We describe a technique to isolate and maintain human small intestinal epithelium in vitro from surgical specimens. We also describe a novel method to maintain human intestinal epithelium subcutaneously in a mouse model for a prolonged period of time. Our methods require various growth factors and the intimate interaction between intestinal sub-epithelial myofibroblasts (ISEMFs and the intestinal epithelial cells to support the epithelial in vitro and in vivo growth. Absence of these myofibroblasts precluded successful maintenance of epithelial cell formation and proliferation beyond just a few days, even in the presence of supportive growth factors. We believe that the methods described here can be used to explore the molecular basis of human intestinal stem cell support, maintenance, and growth.

  5. Fibroblasts and Myofibroblasts in Wound Healing: Force Generation and Measurement

    OpenAIRE

    Li, Bin; Wang, James H-C

    2009-01-01

    Fibroblasts are one of the most abundant cell types in connective tissues. These cells are responsible for tissue homeostasis under normal physiological conditions. When tissues are injured, fibroblasts become activated and differentiate into myofibroblasts, which generate large contractions and actively produce extracellular matrix (ECM) proteins to facilitate wound closure. Both fibroblasts and myofibroblasts play a critical role in wound healing by generating traction and contractile force...

  6. Myofibroblastic tumor associated to superior vena cava syndrome

    International Nuclear Information System (INIS)

    Inflammatory myofibroblastic tumor (IMT) is an uncommon pathological entity of unknown cause, composed of differentiated myofibroblastic cells accompanied by plasma cells, lymphocytes and eosinophils, which involve extrapulmonary and pulmonary tissues. IMT has an unpredictable clinical course, rarely undergoes malignant transformation. Local invasion and involvement of the mediastinum and hiliar structures are unusual manifestations; however; we reports a case of superior vena cava syndrome and IMT

  7. The role of the bi-compartmental stem cell niche in delaying cancer

    Science.gov (United States)

    Shahriyari, Leili; Komarova, Natalia L.

    2015-10-01

    In recent years, by using modern imaging techniques, scientists have found evidence of collaboration between different types of stem cells (SCs), and proposed a bi-compartmental organization of the SC niche. Here we create a class of stochastic models to simulate the dynamics of such a heterogeneous SC niche. We consider two SC groups: the border compartment, S1, is in direct contact with transit-amplifying (TA) cells, and the central compartment, S2, is hierarchically upstream from S1. The S1 SCs differentiate or divide asymmetrically when the tissue needs TA cells. Both groups proliferate when the tissue requires SCs (thus maintaining homeostasis). There is an influx of S2 cells into the border compartment, either by migration, or by proliferation. We examine this model in the context of double-hit mutant generation, which is a rate-limiting step in the development of many cancers. We discover that this type of a cooperative pattern in the stem niche with two compartments leads to a significantly smaller rate of double-hit mutant production compared with a homogeneous, one-compartmental SC niche. Furthermore, the minimum probability of double-hit mutant generation corresponds to purely symmetric division of SCs, consistent with the literature. Finally, the optimal architecture (which minimizes the rate of double-hit mutant production) requires a large proliferation rate of S1 cells along with a small, but non-zero, proliferation rate of S2 cells. This result is remarkably similar to the niche structure described recently by several authors, where one of the two SC compartments was found more actively engaged in tissue homeostasis and turnover, while the other was characterized by higher levels of quiescence (but contributed strongly to injury recovery). Both numerical and analytical results are presented.

  8. Wnt-inhibitory factor 1 dysregulation of the bone marrow niche exhausts hematopoietic stem cells

    OpenAIRE

    Schaniel, Christoph; Sirabella, Dario; Qiu, Jiajing; Niu, Xiaohong; Lemischka, Ihor R.; Moore, Kateri A.

    2011-01-01

    The role of Wnt signaling in hematopoietic stem cell fate decisions remains controversial. We elected to dysregulate Wnt signaling from the perspective of the stem cell niche by expressing the pan Wnt inhibitor, Wnt inhibitory factor 1 (Wif1), specifically in osteoblasts. Here we report that osteoblastic Wif1 overexpression disrupts stem cell quiescence, leading to a loss of self-renewal potential. Primitive stem and progenitor populations were more proliferative and elevated in bone marrow a...

  9. Keeping stem cells under control: New insights into the mechanisms that limit niche-stem cell signaling within the reproductive system.

    Science.gov (United States)

    Inaba, Mayu; Yamashita, Yukiko M; Buszczak, Michael

    2016-08-01

    Adult stem cells reside in specialized microenvironments, called niches, that maintain stem cells in an undifferentiated and self-renewing state. Defining and understanding the mechanisms that restrict niche signaling exclusively to stem cells is crucial to determine how stem cells undergo self-renewal while their progeny, often located just one cell diameter away from the niche, differentiate. Despite extensive studies on the signaling pathways that operate within stem cells and their niches, how this segregation occurs remains elusive. Here we review recent progress on the characterization of niche-stem cell interactions, with a focus on emerging mechanisms that spatially restrict niche signaling. Mol. Reprod. Dev. 83: 675-683, 2016 © 2016 Wiley Periodicals, Inc. PMID:27434704

  10. The canine hepatic progenitor cell niche: molecular characterisation in health and disease.

    Science.gov (United States)

    Kruitwagen, H S; Spee, B; Viebahn, C S; Venema, H B; Penning, L C; Grinwis, G C M; Favier, R P; van den Ingh, T S G A M; Rothuizen, J; Schotanus, B A

    2014-09-01

    Hepatic progenitor cells (HPCs) are an adult stem cell compartment in the liver that contributes to liver regeneration when replication of mature hepatocytes is insufficient. In this study, laser microdissection was used to isolate HPC niches from the livers of healthy dogs and dogs with lobular dissecting hepatitis (LDH), in which HPCs are massively activated. Gene expression of HPC, hepatocyte and biliary markers was determined by quantitative reverse transcriptase PCR. Expression and localisation of selected markers were further studied at the protein level by immunohistochemistry and immunofluorescent double staining in samples of normal liver and liver from dogs with LDH, acute and chronic hepatitis, and extrahepatic cholestasis. Activated HPC niches had higher gene expression of the hepatic progenitor markers OPN, FN14, CD29, CD44, CD133, LIF, LIFR and BMI1 compared to HPCs from normal liver. There was lower expression of albumin, but activated HPC niches were positive for the biliary markers SOX9, HNF1β and keratin 19 by immunohistochemistry and immunofluorescence. Laminin, activated stellate cells and macrophages are abundant extracellular matrix and cellular components of the canine HPC niche. This study demonstrates that the molecular and cellular characteristics of canine HPCs are similar to rodent and human HPCs, and that canine HPCs are distinctively activated in different types of liver disease. PMID:24923752

  11. Pleiotrophin Regulates the Retention and Self-Renewal of Hematopoietic Stem Cells in the Bone Marrow Vascular Niche

    Directory of Open Access Journals (Sweden)

    Heather A. Himburg

    2012-10-01

    Full Text Available The mechanisms through which the bone marrow (BM microenvironment regulates hematopoietic stem cell (HSC fate remain incompletely understood. We examined the role of the heparin-binding growth factor pleiotrophin (PTN in regulating HSC function in the niche. PTN−/− mice displayed significantly decreased BM HSC content and impaired hematopoietic regeneration following myelosuppression. Conversely, mice lacking protein tyrosine phosphatase receptor zeta, which is inactivated by PTN, displayed significantly increased BM HSC content. Transplant studies revealed that PTN action was not HSC autonomous, but rather was mediated by the BM microenvironment. Interestingly, PTN was differentially expressed and secreted by BM sinusoidal endothelial cells within the vascular niche. Furthermore, systemic administration of anti-PTN antibody in mice substantially impaired both the homing of hematopoietic progenitor cells to the niche and the retention of BM HSCs in the niche. PTN is a secreted component of the BM vascular niche that regulates HSC self-renewal and retention in vivo.

  12. Perlecan is required for FGF-2 signaling in the neural stem cell niche

    Directory of Open Access Journals (Sweden)

    Aurelien Kerever

    2014-03-01

    Full Text Available In the adult subventricular zone (neurogenic niche, neural stem cells double-positive for two markers of subsets of neural stem cells in the adult central nervous system, glial fibrillary acidic protein and CD133, lie in proximity to fractones and to blood vessel basement membranes, which contain the heparan sulfate proteoglycan perlecan. Here, we demonstrate that perlecan deficiency reduces the number of both GFAP/CD133-positive neural stem cells in the subventricular zone and new neurons integrating into the olfactory bulb. We also show that FGF-2 treatment induces the expression of cyclin D2 through the activation of the Akt and Erk1/2 pathways and promotes neurosphere formation in vitro. However, in the absence of perlecan, FGF-2 fails to promote neurosphere formation. These results suggest that perlecan is a component of the neurogenic niche that regulates FGF-2 signaling and acts by promoting neural stem cell self-renewal and neurogenesis.

  13. The Glandular Stem/Progenitor Cell Niche in Airway Development and Repair

    OpenAIRE

    Liu, Xiaoming; Engelhardt, John F.

    2008-01-01

    Airway submucosal glands (SMGs) are major secretory structures that lie beneath the epithelium of the cartilaginous airway. These glands are believed to play important roles in normal lung function and airway innate immunity by secreting antibacterial factors, mucus, and fluid into the airway lumen. Recent studies have suggested that SMGs may additionally serve as a protective niche for adult epithelial stem/progenitor cells of the proximal airways. As in the case of other adult stem cell nic...

  14. Mesenchymal stem cells: a perspective from in vitro cultures to in vivo migration and niches

    Directory of Open Access Journals (Sweden)

    A Augello

    2010-09-01

    Full Text Available Mesenchymal Stromal Progenitor/Stem Cells (MSCs are a rare population of non-hematopoietic stromal cells, present in the bone marrow and most connective tissues of the body. They are capable of differentiation into mesenchymal tissues such as bone, cartilage, adipose tissue and muscle. In the absence of specific markers, MSCs have been defined following isolation and culture expansion, by their expression of various molecules including CD90, CD105 and CD73 and absence of markers like CD34, CD45, and CD14. MSCs have extensive proliferative ability in culture in an uncommitted state while retaining their multilineage differentiation potential, which make them attractive candidates for biological cell-based tissue repair approaches. However, their identity in their tissues of origin is not clear and the niches in which they reside are not defined. This review addresses the current state of MSC research including the differentiation potency of culture expanded MSCs, expression of chemokines and their receptors in MSCs – both relevant issues for the advocated use of MSCs for tissue repair and their systemic delivery to the affected tissues. It also reviews current knowledge of MSC niches in their native tissues, addressing the relationship with pericytes. Finally, it provides a scientific basis for the requirement of a thorough characterisation of the endogenous MSC niches within their native tissues in vivo. The knowledge of MSC niches will instruct development of innovative therapeutic measures such as producing pharmacological substances that target endogenous MSCs and their niches in order to activate and guide intrinsic repair and to improve disease outcomes.

  15. Engineering of the Embryonic and Adult Stem Cell Niches

    OpenAIRE

    Hosseinkhani, Mohsen; Shirazi, Reza; Rajaei, Farzad; Mahmoudi, Masoud; Mohammadi, Navid; Abbasi, Mahnaz

    2013-01-01

    Context Stem cells have the potential to generate a renewable source of cells for regenerative medicine due to their ability to self-renew and differentiate to various functional cell types of the adult organism. The extracellular microenvironment plays a pivotal role in controlling stem cell fate responses. Therefore, identification of appropriate environmental stimuli that supports cellular proliferation and lineage-specific differentiation is critical for the clinical application of the st...

  16. The origin of interstitial myofibroblasts in chronic kidney disease

    OpenAIRE

    Grgic, Ivica; Duffield, Jeremy S.; Humphreys, Benjamin D.

    2011-01-01

    Chronic kidney diseases (CKD), independent of their primary cause, lead to progressive, irreversible loss of functional renal parenchyma. Renal pathology in CKD is characterized by tubulointerstitial fibrosis with excessive matrix deposition produced by myofibroblasts. Because blocking the formation of these scar-forming cells represents a logical therapeutic target for patients with progressive fibrotic kidney disease, the origin of renal myofibroblasts is a subject of intense investigation....

  17. Modulation of TGFβ1-Dependent Myofibroblast Differentiation by Hyaluronan

    OpenAIRE

    Webber, Jason; Jenkins, Robert H.; Meran, Soma; Phillips, Aled; Steadman, Robert

    2009-01-01

    Myofibroblasts are contractile cells that are characterized by the expression of α-smooth muscle actin and mediate the closure of wounds and the formation of collagen-rich scars. Their presence in organs such as lungs, liver, and kidney has long been established as a marker of progressive fibrosis. The transforming growth factor beta1-driven differentiation of fibroblasts is a major source of myofibroblasts, and recent data have shown that hyaluronan is a major modulator of this process. This...

  18. Endothelial Progenitor Cell Dysfunction in Myelodysplastic Syndromes: Possible Contribution of a Defective Vascular Niche to Myelodysplasia

    Directory of Open Access Journals (Sweden)

    Luciana Teofili

    2015-05-01

    Full Text Available We set a model to replicate the vascular bone marrow niche by using endothelial colony forming cells (ECFCs, and we used it to explore the vascular niche function in patients with low-risk myelodysplastic syndromes (MDS. Overall, we investigated 56 patients and we observed higher levels of ECFCs in MDS than in healthy controls; moreover, MDS ECFCs were found variably hypermethylated for p15INK4b DAPK1, CDH1, or SOCS1. MDS ECFCs exhibited a marked adhesive capacity to normal mononuclear cells. When normal CD34+ cells were co-cultured with MDS ECFCs, they generated significant lower amounts of CD11b+ and CD41+ cells than in co-culture with normal ECFCs. At gene expression profile, several genes involved in cell adhesion were upregulated in MDS ECFCs, while several members of the Wingless and int (Wnt pathways were underexpressed. Furthermore, at miRNA expression profile, MDS ECFCs hypo-expressed various miRNAs involved in Wnt pathway regulation. The addition of Wnt3A reduced the expression of intercellular cell adhesion molecule-1 on MDS ECFCs and restored the defective expression of markers of differentiation. Overall, our data demonstrate that in low-risk MDS, ECFCs exhibit various primary abnormalities, including putative MDS signatures, and suggest the possible contribution of the vascular niche dysfunction to myelodysplasia.

  19. Stem Cell Niche, the Microenvironment and Immunological Crosstalk

    Institute of Scientific and Technical Information of China (English)

    Law Sujata; S. Chaudhuri

    2008-01-01

    The concept of stem cells, their physiological existence, the intricate anatomical localization, the known and the unknown functions, and their exclusive utility for the purpose of regenerative medicine, are all now encompassed within an emergent question, 'how compatible these cells are immunologically?'Indeed, the medical aspects of stem cells are dependent on a large number of queries based on the basic properties of the cells. It has greatly been emphasized to probe into the basic research on stem cells before any successful therapeutic attempts are made. One of the intricate aspects of the adult stem cells is its immunological behavior in relation to the microenvironmental associates, the stromal ceils in the presence of a suitable target.

  20. Myofibroblastic sarcomas: a clinicopathological study of 20 cases

    Institute of Scientific and Technical Information of China (English)

    MENG Guo-zhao; ZHANG Hong-ying; BU Hong; ZHANG Xian-liang; PANG Zong-guo; KE Qi; LIU Xi; YANG Guo

    2007-01-01

    Background Myofibroblastic sarcoma was used to be a controversial neoplasm. This study investigated the clinicopathological features of 20 cases of myofibroblastic sarcoma arising in different locations.Methods The paraffin-embedded tissue samples from 20 cases of patients with myofibroblastic sarcoma were stained immunohistochemically, and 5 cases examined by electron microscopy. Student's t test was used to analyze the difference of Ki-67 labeling index between grade 1 and grade 2 myofibroblastic sarcomas.Results Histologically, the tumors were composed of slender spindle cells with eosinophilic cytoplasm, and fusiform,tapering, wavy, or plump ovoid; vesicular nuclei and a small central eosinophilic nucleoli. Immunohistochemically, the tumor cells expressed smooth muscle actin (18/20), muscle specific actin (16/20), fibronectin (20/20) and desmin (2/20).Ultrastructurally, the tumor cells revealed abundant rough endoplasmic reticulum and longitudinally arranged fine filaments with focal densities in the cytoplasm. A clinical follow-up of 19 patients showed that 2 cases experienced local recurrence and distant metastasis 6 months to 4 years after the initial operation. Nine cases recurred locally 17 to 46 months after the initial excision, and 9 cases were alive with no evidence of disease.Conclusions Myofibroblastic sarcomas, which exhibit diverse histological appearance, can easily be misdiagnosed as benign tumors. Myofibroblastic sarcomas are local destructive lesions with frequent recurrence, and may metastase distantly.

  1. Inflammatory myofibroblastic tumor of perineal soft tissue : a case report

    International Nuclear Information System (INIS)

    Inflammatory myofibroblastic tumor is a rare benign condition of unknown etiology, and it may simulate malignancy. It is composed of myofibroblast, plasma cells and histiocytes and is found in lung, the liver, orbit, skin, mesentery, retroperitoneum and maxillary sinus. We report a case of inflammatory myofibroblastic tumor of perineal subcutaneous fat in a 35-year-old woman who complained of a palpable mass. Ultrasonography revealed a well-marginated lobulated hypoechoic lesion with peripheral poorly-defined hyperechoic stands in the subcutaneous fat of the right perineum. The lesion demonstrated low signal intensity on T1-weighted images and of heterogenous high signal intensity on T2-weighted images, compared with surrounding muscle. After intravenous injection of gadolinium, it showed clear homogeneous enhancement but poorly-defined adjacent strands. The final histologic diagnosis was inflammatory myofibroblastic tumor

  2. Inflammatory myofibroblastic tumor of perineal soft tissue : a case report

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jong Myeong; Kim, Kyu Soon; Kwon, Soon Tae; Kim, Jong Chul; Song, Kyu Sang [Chungnam National Univ. Hospital, Taejeon (Korea, Republic of)

    2001-10-01

    Inflammatory myofibroblastic tumor is a rare benign condition of unknown etiology, and it may simulate malignancy. It is composed of myofibroblast, plasma cells and histiocytes and is found in lung, the liver, orbit, skin, mesentery, retroperitoneum and maxillary sinus. We report a case of inflammatory myofibroblastic tumor of perineal subcutaneous fat in a 35-year-old woman who complained of a palpable mass. Ultrasonography revealed a well-marginated lobulated hypoechoic lesion with peripheral poorly-defined hyperechoic stands in the subcutaneous fat of the right perineum. The lesion demonstrated low signal intensity on T1-weighted images and of heterogenous high signal intensity on T2-weighted images, compared with surrounding muscle. After intravenous injection of gadolinium, it showed clear homogeneous enhancement but poorly-defined adjacent strands. The final histologic diagnosis was inflammatory myofibroblastic tumor.

  3. TRAPping telomerase within the intestinal stem cell niche

    OpenAIRE

    Pech, Matthew F.; Artandi, Steven E.

    2011-01-01

    Recent work from Hans Clevers' lab reveals high telomerase activity and telomere length in dividing LGR5-positive intestinal stem cells. They further report random chromosome segregation and thus challenge the ‘immortal strand' hypothesis at least for this stem cell population.

  4. Red wine polyphenolics reduce the expression of inflammation markers in human colon-derived CCD-18Co myofibroblast cells: potential role of microRNA-126.

    Science.gov (United States)

    Angel-Morales, Gabriela; Noratto, Giuliana; Mertens-Talcott, Susanne

    2012-07-01

    Chronic intestinal inflammation is an established risk factor for colon cancer. Polyphenolic compounds from fruit and vegetables have been shown to have anti-inflammatory properties in several cell lines and tissues. However, their anti-inflammatory mechanisms, involving microRNAs in the regulation of inflammation, have not been extensively investigated. The goal of this research was to assess the chemopreventive potential of polyphenolics extracted from red wine made with Lenoir grapes (Vitis aestivalis hybrid) in human colon-derived CCD-18Co myofibroblasts cells, and to assess the potential involvement of microRNA-126 (miR-126) in the underlying mechanisms. The results show that the polyphenolic red wine extract (WE) decreased mRNA expression of lipopolysaccharide (LPS)-induced inflammatory mediators NF-kB, ICAM-1, VCAM-1, and PECAM-1 by 1.95-, 1.98-, 1.52-, and 1.84-fold respectively, in a dose dependent manner (0-100 μg of gallic acid equivalent (GAE) mL(-1)) down to 0.80-, 0.79-, 0.66-, and 0.68-fold in DMSO-treated control cells not challenged with LPS, respectively. Correspondingly, miR-126, which has a target region within the 3'-UTR of VCAM-1 mRNA, was increased 2.79-fold by the WE at 100 μg GAE mL(-1). The potential role of miR-126 was confirmed by transfecting cells with a specific miR-126-antagomir, as-miR-126. Transfection with as-miR-126 down-regulated miR-126 to 0.71-fold in the control cells and up-regulated mRNA levels of NF-kB, ICAM-1, VCAM-1, and PECAM-1 to 1.80-, 1.49-, 2.30-, and 1.95-fold of controls, respectively. WE at 100 μg GAE mL(-1) partially reversed the effects of the as-miR-126 to 1.02-, 1.01-, 1.04-, and 1.05-fold, for mRNA levels of NF-kB, ICAM-1, VCAM-1, and PECAM-1 respectively. This indicates the potential role of miR-126 in the anti-inflammatory properties of polyphenolics from red wine in CCD-18Co myofibroblasts cells. PMID:22572890

  5. Stem cell decisions: a twist of fate or a niche market?

    Science.gov (United States)

    Januschke, Jens; Näthke, Inke

    2014-10-01

    Establishing and maintaining cell fate in the right place at the right time is a key requirement for normal tissue maintenance. Stem cells are at the core of this process. Understanding how stem cells balance self-renewal and production of differentiating cells is key for understanding the defects that underpin many diseases. Both, external cues from the environment and cell intrinsic mechanisms can control the outcome of stem cell division. The role of the orientation of stem cell division has emerged as an important mechanism for specifying cell fate decisions. Although, the alignment of cell divisions can dependent on spatial cues from the environment, maintaining stemness is not always linked to positioning of stem cells in a particular microenvironment or `niche'. Alternate mechanisms that could contribute to cellular memory include differential segregation of centrosomes in asymmetrically dividing cells. PMID:24613913

  6. Aldosterone induces myofibroblast EGF secretion to regulate epithelial colonic permeability.

    Science.gov (United States)

    Miró, Lluïsa; Pérez-Bosque, Anna; Maijó, Mònica; Amat, Concepció; Naftalin, Richard J; Moretó, Miquel

    2013-05-01

    In vivo studies show that raised aldosterone (Aldo) during low-Na adaptation regulates the growth of pericryptal myofibroblasts and reduces the permeability of the colonic epithelium. The aim of this study was to reproduce in vitro the in vivo condition of increased Aldo using human CCD-18Co myofibroblasts and T84 colonic epithelial cells to measure myofibroblast and epithelial proliferation and the expression of intercellular junction proteins. Proliferation was quantified by measuring 5-bromo-2'-deoxyuridine incorporation. The myofibroblast expression of EGF, VEGFa, and transforming growth factor-β1 (TGF-β1) was measured by real-time PCR and the expression of junctional complex proteins by Western blot. Aldo stimulated the proliferation of myofibroblasts by 70% (P < 0.05) and increased EGF mRNA expression by 30% (P < 0.05) without affecting VEGFa and TGF-β1. EGF concentration in the incubation medium increased by 30% (P < 0.05) 24 h after Aldo addition, and these effects were prevented by the addition of spironolactone. Myofibroblast proliferation in response to Aldo was mediated by EGF receptor (EGFR) and involved both MAPKK and phosphatidylinositol 3-kinase pathways. When T84 cells were incubated with medium from myofibroblasts stimulated with Aldo (conditioned medium), the expression of β-catenin and claudin IV was increased by 30% (P < 0.05) and proliferation by 40% (P < 0.05). T84 proliferation decreased when α-EGF, or the EGFR antagonist AG1478, was present. Results in vivo indicate that rats fed a low-salt diet showed an increased expression of EGF and EGFR in the colonic mucosa. These results support the view that changes in colonic permeability during low-Na adaptation are mediated by the EGF secreted by myofibroblasts in response to raised Aldo. PMID:23467299

  7. Chronic hypoxia inhibits MMP-2 activation and cellular invasion in human cardiac myofibroblasts

    OpenAIRE

    Riches, Kirsten; Morley, Michael E.; Turner, Neil A; O'Regan, David J; Ball, Stephen G; Peers, Chris; Porter, Karen E

    2009-01-01

    Cardiac myofibroblasts are pivotal to adaptive remodelling after myocardial infarction (MI). These normally quiescent cells invade and proliferate as a wound healing response, facilitated by activation of matrix metalloproteinases, particularly MMP-2. Following MI these reparative events occur under chronically hypoxic conditions yet the mechanisms by which hypoxia might modulate MMP-2 activation and cardiac myofibroblast invasion have not been investigated. Human cardiac myofibroblasts cultu...

  8. Polyphenolic extracts from cowpea (Vigna unguiculata) protect colonic myofibroblasts (CCD18Co cells) from lipopolysaccharide (LPS)-induced inflammation--modulation of microRNA 126.

    Science.gov (United States)

    Ojwang, Leonnard O; Banerjee, Nivedita; Noratto, Giuliana D; Angel-Morales, Gabriela; Hachibamba, Twambo; Awika, Joseph M; Mertens-Talcott, Susanne U

    2015-01-01

    Cowpea (Vigna unguiculata) is a drought tolerant crop with several agronomic advantages over other legumes. This study evaluated varieties from four major cowpea phenotypes (black, red, light brown and white) containing different phenolic profiles for their anti-inflammatory property on non-malignant colonic myofibroblasts (CCD18Co) cells challenged with an endotoxin (lipopolysaccharide, LPS). Intracellular reactive oxygen species (ROS) assay on the LPS-stimulated cells revealed antioxidative potential of black and red cowpea varieties. Real-time qRT-PCR analysis in LPS-stimulated cells revealed down-regulation of proinflammatory cytokines (IL-8, TNF-α, VCAM-1), transcription factor NF-κB and modulation of microRNA-126 (specific post-transcriptional regulator of VCAM-1) by cowpea polyphenolics. The ability of cowpea polyphenols to modulate miR-126 signaling and its target gene VCAM-1 were studied in LPS-stimulated endothelial cells transfected with a specific inhibitor of miR-126, and treated with 10 mg GAE/L black cowpea extract where the extract in part reversed the effect of the miR-126 inhibitor. This suggests that cowpea may exert their anti-inflammatory activities at least in part through induction of miR-126 that then down-regulate VCAM-1 mRNA and protein expressions. Overall, Cowpea therefore is promising as an anti-inflammatory dietary component. PMID:25300227

  9. Stroke increases neural stem cells and angiogenesis in the neurogenic niche of the adult mouse.

    Directory of Open Access Journals (Sweden)

    Rui Lan Zhang

    Full Text Available The unique cellular and vascular architecture of the adult ventricular-subventricular zone (V/SVZ neurogenic niche plays an important role in regulating neural stem cell function. However, the in vivo identification of neural stem cells and their relationship to blood vessels within this niche in response to stroke remain largely unknown. Using whole-mount preparation of the lateral ventricle wall, we examined the architecture of neural stem cells and blood vessels in the V/SVZ of adult mouse over the course of 3 months after onset of focal cerebral ischemia. Stroke substantially increased the number of glial fibrillary acidic protein (GFAP positive neural stem cells that are in contact with the cerebrospinal fluid (CSF via their apical processes at the center of pinwheel structures formed by ependymal cells residing in the lateral ventricle. Long basal processes of these cells extended to blood vessels beneath the ependymal layer. Moreover, stroke increased V/SVZ endothelial cell proliferation from 2% in non-ischemic mice to 12 and 15% at 7 and 14 days after stroke, respectively. Vascular volume in the V/SVZ was augmented from 3% of the total volume prior to stroke to 6% at 90 days after stroke. Stroke-increased angiogenesis was closely associated with neuroblasts that expanded to nearly encompass the entire lateral ventricular wall in the V/SVZ. These data indicate that stroke induces long-term alterations of the neural stem cell and vascular architecture of the adult V/SVZ neurogenic niche. These post-stroke structural changes may provide insight into neural stem cell mediation of stroke-induced neurogenesis through the interaction of neural stem cells with proteins in the CSF and their sub-ependymal neurovascular interaction.

  10. Lung epithelial stem cells and their niches: Fgf10 takes center stage.

    Science.gov (United States)

    Volckaert, Thomas; De Langhe, Stijn

    2014-01-01

    Throughout life adult animals crucially depend on stem cell populations to maintain and repair their tissues to ensure life-long organ function. Stem cells are characterized by their capacity to extensively self-renew and give rise to one or more differentiated cell types. These powerful stem cell properties are key to meet the changing demand for tissue replacement during normal lung homeostasis and regeneration after lung injury. Great strides have been made over the last few years to identify and characterize lung epithelial stem cells as well as their lineage relationships. Unfortunately, knowledge on what regulates the behavior and fate specification of lung epithelial stem cells is still limited, but involves communication with their microenvironment or niche, a local tissue environment that hosts and influences the behaviors or characteristics of stem cells and that comprises other cell types and extracellular matrix. As such, an intimate and dynamic epithelial-mesenchymal cross-talk, which is also essential during lung development, is required for normal homeostasis and to mount an appropriate regenerative response after lung injury. Fibroblast growth factor 10 (Fgf10) signaling in particular seems to be a well-conserved signaling pathway governing epithelial-mesenchymal interactions during lung development as well as between different adult lung epithelial stem cells and their niches. On the other hand, disruption of these reciprocal interactions leads to a dysfunctional epithelial stem cell-niche unit, which may culminate in chronic lung diseases such as chronic obstructive pulmonary disease (COPD), chronic asthma and idiopathic pulmonary fibrosis (IPF). PMID:24891877

  11. Rampant infections of bone marrow stem cell niches as triggers for spondyloarthropathies and rheumatoid arthritis.

    Science.gov (United States)

    Berthelot, Jean-Marie; Sibilia, Jean

    2016-01-01

    Tropheryma Whipplei can induce rheumatism mimicking SpA or RA, but even more rampant bacterial/viral infections in epiphyseal bones could also contribute to the onset of RA and SpA. Indeed, as bone marrow stem cell niches are enriched in Tregs and myeloid derived suppressor cells, these areas are favourable for the persistence of quiescent viruses and/or dormant bacteria. This review focuses on the possibility that such silent infections of bone marrow stem cell niches might contribute to the pathogenesis of SpA and RA, at least during their onset. Some infections can affect the bone marrow mesenchymal stem cells, which can transmit these pathogens to their progeny. Transient but repeated revivals of viruses or dormant bacteria could promote the conversion of marrow regulatory T cells into effector phenotypes, leading to autoimmunity in the epiphyseal bone marrow, entheses and adjacent synovium. This scenario would also fit the flares of rheumatic disorders and explain why some joints or enthuses can be severely involved whereas their neighbours remain intact. The efficiency of anti-TNF drugs does not rule out a role of persistent infections in SpA and RA. These drugs do not affect chlamydial clearance, or the reactivation of latent Salmonella enterica serovar Typhimurium in mice or Epstein-Barr virus in humans. Anti-TNF might even prevent, rather than foster, the revival of dormant bacteria and viruses in marrow stem cell niches. Indeed, anti-TNF enhance the maturation of the immunosuppressive immature myeloid cells around stem cells into dendritic cells and macrophages, thus restoring immune responses in these areas. PMID:26886813

  12. Reciprocal interactions between endothelial cells and macrophages in angiogenic vascular niches

    International Nuclear Information System (INIS)

    The ability of macrophages to promote vascular growth has been associated with the secretion and local delivery of classic proangiogenic factors (e.g., VEGF-A and proteases). More recently, a series of studies have also revealed that physical contact of macrophages with growing blood vessels coordinates vascular fusion of emerging sprouts. Interestingly, the interactions between macrophages and vascular endothelial cells (ECs) appear to be bidirectional, such that activated ECs also support the expansion and differentiation of proangiogenic macrophages from myeloid progenitors. Here, we discuss recent findings suggesting that dynamic angiogenic vascular niches might also exist in vivo, e.g. in tumors, where sprouting blood vessels and immature myeloid cells like monocytes engage in heterotypic interactions that are required for angiogenesis. Finally, we provide an account of emerging mechanisms of cell-to-cell communication that rely on secreted microvesicles, such as exosomes, which can offer a vehicle for the rapid exchange of molecules and genetic information between macrophages and ECs engaged in angiogenesis. -- Highlights: • Macrophages promote angiogenesis by secreting proangiogenic factors. • Macrophages modulate angiogenesis via cell-to-cell contacts with endothelial cells. • Endothelial cells promote the differentiation of proangiogenic macrophages. • Macrophages and endothelial cells may cooperate to form angiogenic vascular niches

  13. Reciprocal interactions between endothelial cells and macrophages in angiogenic vascular niches

    Energy Technology Data Exchange (ETDEWEB)

    Baer, Caroline; Squadrito, Mario Leonardo [The Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL), 1015 Lausanne (Switzerland); Iruela-Arispe, M. Luisa, E-mail: arispe@mcdb.ucla.edu [The Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL), 1015 Lausanne (Switzerland); Department of Molecular, Cell and Developmental Biology and Molecular Biology Institute, University of California, Los Angeles 90095, CA (United States); De Palma, Michele, E-mail: michele.depalma@epfl.ch [The Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL), 1015 Lausanne (Switzerland)

    2013-07-01

    The ability of macrophages to promote vascular growth has been associated with the secretion and local delivery of classic proangiogenic factors (e.g., VEGF-A and proteases). More recently, a series of studies have also revealed that physical contact of macrophages with growing blood vessels coordinates vascular fusion of emerging sprouts. Interestingly, the interactions between macrophages and vascular endothelial cells (ECs) appear to be bidirectional, such that activated ECs also support the expansion and differentiation of proangiogenic macrophages from myeloid progenitors. Here, we discuss recent findings suggesting that dynamic angiogenic vascular niches might also exist in vivo, e.g. in tumors, where sprouting blood vessels and immature myeloid cells like monocytes engage in heterotypic interactions that are required for angiogenesis. Finally, we provide an account of emerging mechanisms of cell-to-cell communication that rely on secreted microvesicles, such as exosomes, which can offer a vehicle for the rapid exchange of molecules and genetic information between macrophages and ECs engaged in angiogenesis. -- Highlights: • Macrophages promote angiogenesis by secreting proangiogenic factors. • Macrophages modulate angiogenesis via cell-to-cell contacts with endothelial cells. • Endothelial cells promote the differentiation of proangiogenic macrophages. • Macrophages and endothelial cells may cooperate to form angiogenic vascular niches.

  14. Rab8a vesicles regulate Wnt ligand delivery and Paneth cell maturation at the intestinal stem cell niche.

    Science.gov (United States)

    Das, Soumyashree; Yu, Shiyan; Sakamori, Ryotaro; Vedula, Pavan; Feng, Qiang; Flores, Juan; Hoffman, Andrew; Fu, Jiang; Stypulkowski, Ewa; Rodriguez, Alexis; Dobrowolski, Radek; Harada, Akihiro; Hsu, Wei; Bonder, Edward M; Verzi, Michael P; Gao, Nan

    2015-06-15

    Communication between stem and niche supporting cells maintains the homeostasis of adult tissues. Wnt signaling is a crucial regulator of the stem cell niche, but the mechanism that governs Wnt ligand delivery in this compartment has not been fully investigated. We identified that Wnt secretion is partly dependent on Rab8a-mediated anterograde transport of Gpr177 (wntless), a Wnt-specific transmembrane transporter. Gpr177 binds to Rab8a, depletion of which compromises Gpr177 traffic, thereby weakening the secretion of multiple Wnts. Analyses of generic Wnt/β-catenin targets in Rab8a knockout mouse intestinal crypts indicate reduced signaling activities; maturation of Paneth cells - a Wnt-dependent cell type - is severely affected. Rab8a knockout crypts show an expansion of Lgr5(+) and Hopx(+) cells in vivo. However, in vitro, the knockout enteroids exhibit significantly weakened growth that can be partly restored by exogenous Wnts or Gsk3β inhibitors. Immunogold labeling and surface protein isolation identified decreased plasma membrane localization of Gpr177 in Rab8a knockout Paneth cells and fibroblasts. Upon stimulation by exogenous Wnts, Rab8a-deficient cells show ligand-induced Lrp6 phosphorylation and transcriptional reporter activation. Rab8a thus controls Wnt delivery in producing cells and is crucial for Paneth cell maturation. Our data highlight the profound tissue plasticity that occurs in response to stress induced by depletion of a stem cell niche signal. PMID:26015543

  15. 肿瘤干细胞niche与肿瘤%Cancer stem cell niche and cancer

    Institute of Scientific and Technical Information of China (English)

    张海谱

    2010-01-01

    Cancer stem cell (CSC) is the source of tumor development and metastasis, and may become the target of cancer therapy in the future. Niche refers to a micro-environment that makes up the basis of stem cell existence. Niche is involved in tumor development by regulating the growth and changes of CSC. It is also closely related to tumor migration and metastasis. Eradicating CSC through modifying niche may be a new therapeutic strategy for curing cancer.%肿瘤干细胞(CSC)是肿瘤发生、发展、转移的根源,是未来肿瘤治疗的靶标.niche指一种微环境,是干细胞存在的基础.niche通过调控CSC的生长变化而参与肿瘤的发生发展,与肿瘤转移迁徙也密切相关,通过影响niche而根除CSC治愈肿瘤是一种新的治疗肿瘤的策略.

  16. Cancer Microenvironment: What Can We Learn from the Stem Cell Niche

    Directory of Open Access Journals (Sweden)

    Lukas Lacina

    2015-10-01

    Full Text Available Epidermal stem cells (ESCs are crucial for maintenance and self- renewal of skin epithelium and also for regular hair cycling. Their role in wound healing is also indispensable. ESCs reside in a defined outer root sheath portion of hair follicle—also known as the bulge region. ECS are also found between basal cells of the interfollicular epidermis or mucous membranes. The non-epithelial elements such as mesenchymal stem cell-like elements of dermis or surrounding adipose tissue can also contribute to this niche formation. Cancer stem cells (CSCs participate in formation of common epithelial malignant diseases such as basal cell or squamous cell carcinoma. In this review article, we focus on the role of cancer microenvironment with emphasis on the effect of cancer-associated fibroblasts (CAFs. This model reflects various biological aspects of interaction between cancer cell and CAFs with multiple parallels to interaction of normal epidermal stem cells and their niche. The complexity of intercellular interactions within tumor stroma is depicted on example of malignant melanoma, where keratinocytes also contribute the microenvironmental landscape during early phase of tumor progression. Interactions seen in normal bulge region can therefore be an important source of information for proper understanding to melanoma. The therapeutic consequences of targeting of microenvironment in anticancer therapy and for improved wound healing are included to article.

  17. Cancer Microenvironment: What Can We Learn from the Stem Cell Niche.

    Science.gov (United States)

    Lacina, Lukas; Plzak, Jan; Kodet, Ondrej; Szabo, Pavol; Chovanec, Martin; Dvorankova, Barbora; Smetana, Karel

    2015-01-01

    Epidermal stem cells (ESCs) are crucial for maintenance and self- renewal of skin epithelium and also for regular hair cycling. Their role in wound healing is also indispensable. ESCs reside in a defined outer root sheath portion of hair follicle-also known as the bulge region. ECS are also found between basal cells of the interfollicular epidermis or mucous membranes. The non-epithelial elements such as mesenchymal stem cell-like elements of dermis or surrounding adipose tissue can also contribute to this niche formation. Cancer stem cells (CSCs) participate in formation of common epithelial malignant diseases such as basal cell or squamous cell carcinoma. In this review article, we focus on the role of cancer microenvironment with emphasis on the effect of cancer-associated fibroblasts (CAFs). This model reflects various biological aspects of interaction between cancer cell and CAFs with multiple parallels to interaction of normal epidermal stem cells and their niche. The complexity of intercellular interactions within tumor stroma is depicted on example of malignant melanoma, where keratinocytes also contribute the microenvironmental landscape during early phase of tumor progression. Interactions seen in normal bulge region can therefore be an important source of information for proper understanding to melanoma. The therapeutic consequences of targeting of microenvironment in anticancer therapy and for improved wound healing are included to article. PMID:26473842

  18. Osteoblastic and Vascular Endothelial Niches, Their Control on Normal Hematopoietic Stem Cells, and Their Consequences on the Development of Leukemia

    Directory of Open Access Journals (Sweden)

    Bella S. Guerrouahen

    2011-01-01

    Full Text Available Stem cell self-renewal is regulated by intrinsic mechanisms and extrinsic signals mediated via specialized microenvironments called “niches.” The best-characterized stem cell is the hematopoietic stem cell (HSC. Self-renewal and differentiation ability of HSC are regulated by two major elements: endosteal and vascular regulatory elements. The osteoblastic niche localized at the inner surface of the bone cavity might serve as a reservoir for long-term HSC storage in a quiescent state. Whereas the vascular niche, which consists of sinusoidal endothelial cell lining blood vessel, provides an environment for short-term HSC proliferation and differentiation. Both niches act together to maintain hematopoietic homeostasis. In this paper, we provide some principles applying to the hematopoietic niches, which will be useful in the study and understanding of other stem cell niches. We will discuss altered microenvironment signaling leading to myeloid lineage disease. And finally, we will review some data on the development of acute myeloid leukemia from a subpopulation called leukemia-initiating cells (LIC, and we will discuss on the emerging evidences supporting the influence of the microenvironment on chemotherapy resistance.

  19. Regulation of hematopoiesis and the hematopoietic stem cell niche by Wnt signaling pathways

    Institute of Scientific and Technical Information of China (English)

    Michael J Nemeth; David M Bodine

    2007-01-01

    Hematopoietic stem cells (HSCs) are a rare population of cells that are responsible for life-long generation of blood cells of all lineages. In order to maintain their numbers, HSCs must establish a balance between the opposing cell fates of self-renewal (in which the ability to function as HSCs is retained) and initiation of hematopoietic differentiation. Multiple signaling pathways have been implicated in the regulation of HSC cell fate. One such set of pathways are those activated by the Wnt family of ligands. Wnt signaling pathways play a crucial role during embryogenesis and deregulation of these pathways has been implicated in the formation of solid tumors. Wnt signaling also plays a role in the regulation of stem cells from multiple tissues, such as embryonic, epidermal, and intestinal stem cells. However, the function of Wnt signaling in HSC biology is still controversial. In this review, we will discuss the basic characteristics of the adult HSC and its regulatory microenvironment, the "niche", focusing on the regulation of the HSC and its niche by the Wnt signaling pathways.

  20. Osteogenic and neurogenic stem cells in their own place: unraveling differences and similarities between niches

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    Wanda Lattanzi

    2015-11-01

    Full Text Available Although therapeutic use of stem cells is already available in some tissues (cornea, blood, skin, in most organs we are far from reaching the translational goal of regenerative medicine. In the nervous system, due to intrinsic features which make it refractory to regeneration/repair,it is very hard to obtainfunctionally-integrated regenerative outcomes, evenstarting from its own stem cells(the neural stem cells; NSCs. Besides NSCs, mesenchymal stem cells (MSCs have also been proposed for therapeutic purposes in neurological diseases. Yet, direct (regenerative and indirect (bystander effects are often confused, as are MSCs and bone marrow-derived (stromal, osteogenic stem cells (BMSCs, whoseplasticity isactually overestimated (i.e. trans-differentiation along non-mesodermal lineages, including neural fates.In order to better understand failure in the "regenerative" use of stem cells for neurological disorders,it could be helpful to understand how NSCs and BMSCs have adapted to their respective organ niches. In this perspective, here the adult osteogenic and neurogenic niches are considered and compared within their in vivo environment.

  1. Parabronchial smooth muscle constitutes an airway epithelial stem cell niche in the mouse lung after injury.

    Science.gov (United States)

    Volckaert, Thomas; Dill, Erik; Campbell, Alice; Tiozzo, Caterina; Majka, Susan; Bellusci, Saverio; De Langhe, Stijn P

    2011-11-01

    During lung development, parabronchial SMC (PSMC) progenitors in the distal mesenchyme secrete fibroblast growth factor 10 (Fgf10), which acts on distal epithelial progenitors to promote their proliferation. β-catenin signaling within PSMC progenitors is essential for their maintenance, proliferation, and expression of Fgf10. Here, we report that this Wnt/Fgf10 embryonic signaling cascade is reactivated in mature PSMCs after naphthalene-induced injury to airway epithelium. Furthermore, we found that this paracrine Fgf10 action was essential for activating surviving variant Clara cells (the cells in the airway epithelium from which replacement epithelial cells originate) located at the bronchoalveolar duct junctions and adjacent to neuroendocrine bodies. After naphthalene injury, PSMCs secreted Fgf10 to activate Notch signaling and induce Snai1 expression in surviving variant Clara cells, which subsequently underwent a transient epithelial to mesenchymal transition to initiate the repair process. Epithelial Snai1 expression was important for regeneration after injury. We have therefore identified PSMCs as a stem cell niche for the variant Clara cells in the lung and established that paracrine Fgf10 signaling from the niche is critical for epithelial repair after naphthalene injury. These findings also have implications for understanding the misregulation of lung repair in asthma and cancer. PMID:21985786

  2. Stem Cell Interaction with Somatic Niche May Hold the Key to Fertility Restoration in Cancer Patients

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    Deepa Bhartiya

    2012-01-01

    Full Text Available The spontaneous return of fertility after bone marrow transplantation or heterotopic grafting of cryopreserved ovarian cortical tissue has surprised many, and a possible link with stem cells has been proposed. We have reviewed the available literature on ovarian stem cells in adult mammalian ovaries and presented a model that proposes that the ovary harbors two distinct populations of stem cells, namely, pluripotent, quiescent, very small embryonic-like stem cells (VSELs, and slightly larger “progenitor” ovarian germ stem cells (OGSCs. Besides compromising the somatic niche, oncotherapy destroys OGSCs since, like tumor cells, they are actively dividing; however VSELs persist since they are relatively quiescent. BMT or transplanted ovarian cortical tissue may help rejuvenate the ovarian niche, which possibly supports differentiation of persisting VSELs resulting in neo-oogenesis and follicular development responsible for successful pregnancies. Postnatal oogenesis in mammalian ovary from VSELs may be exploited for fertility restoration in cancer survivors including those who were earlier deprived of gametes and/or gonadal tissue cryopreservation options.

  3. The myofibroblast, multiple origins for major roles in normal and pathological tissue repair

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    Micallef Ludovic

    2012-06-01

    Full Text Available Abstract Myofibroblasts differentiate, invade and repair injured tissues by secreting and organizing the extracellular matrix and by developing contractile forces. When tissues are damaged, tissue homeostasis must be re-established, and repair mechanisms have to rapidly provide harmonious mechanical tissue organization, a process essentially supported by (myofibroblasts. Under physiological conditions, the secretory and contractile activities of myofibroblasts are terminated when the repair is complete (scar formation but the functionality of the tissue is only rarely perfectly restored. At the end of the normal repair process, myofibroblasts disappear by apoptosis but in pathological situations, myofibroblasts likely remain leading to excessive scarring. Myofibroblasts originate from different precursor cells, the major contribution being from local recruitment of connective tissue fibroblasts. However, local mesenchymal stem cells, bone marrow-derived mesenchymal stem cells and cells derived from an epithelial-mesenchymal transition process, may represent alternative sources of myofibroblasts when local fibroblasts are not able to satisfy the requirement for these cells during repair. These diverse cell types probably contribute to the appearance of myofibroblast subpopulations which show specific biological properties and which are important to understand in order to develop new therapeutic strategies for treatment of fibrotic and scarring diseases.

  4. Tenascin-C is required for normal Wnt/β-catenin signaling in the whisker follicle stem cell niche.

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    Hendaoui, Ismaïl; Tucker, Richard P; Zingg, Dominik; Bichet, Sandrine; Schittny, Johannes; Chiquet-Ehrismann, Ruth

    2014-11-01

    Whisker follicles have multiple stem cell niches, including epidermal stem cells in the bulge as well as neural crest-derived stem cells and mast cell progenitors in the trabecular region. The neural crest-derived stem cells are a pool of melanocyte precursors. Previously, we found that the extracellular matrix glycoproteins tenascin-C and tenascin-W are expressed near CD34-positive cells in the trabecular stem cell niche of mouse whisker follicles. Here, we analyzed whiskers from tenascin-C knockout mice and found intrafollicular adipocytes and supernumerary mast cells. As Wnt/β-catenin signaling promotes melanogenesis and suppresses the differentiation of adipocytes and mast cells, we analyzed β-catenin subcellular localization in the trabecular niche. We found cytoplasmic and nuclear β-catenin in wild-type mice reflecting active Wnt/β-catenin signaling, whereas β-catenin in tenascin-C knockout mice was mostly cell membrane-associated and thus transcriptionally inactive. Furthermore, cells expressing the Wnt/β-catenin target gene cyclin D1 were enriched in the CD34-positive niches of wild-type compared to tenascin-C knockout mice. We then tested the effects of tenascins on this signaling pathway. We found that tenascin-C and tenascin-W can be co-precipitated with Wnt3a. In vitro, substrate bound tenascins promoted β-catenin-mediated transcription in the presence of Wnt3a, presumably due to the sequestration and concentration of Wnt3a near the cell surface. We conclude that the presence of tenascin-C in whiskers assures active Wnt/β-catenin signaling in the niche thereby maintaining the stem cell pool and suppressing aberrant differentiation, while in the knockout mice with reduced Wnt/β-catenin signaling, stem cells from the trabecular niche can differentiate into ectopic adipocytes and mast cells. PMID:25196097

  5. Mesenchymal morphogenesis of embryonic stem cells dynamically modulates the biophysical microtissue niche

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    Kinney, Melissa A.; Saeed, Rabbia; McDevitt, Todd C.

    2014-01-01

    Stem cell fate and function are dynamically modulated by the interdependent relationships between biochemical and biophysical signals constituting the local 3D microenvironment. While approaches to recapitulate the stem cell niche have been explored for directing stem cell differentiation, a quantitative relationship between embryonic stem cell (ESC) morphogenesis and intrinsic biophysical cues within three-dimensional microtissues has not been established. In this study, we demonstrate that mesenchymal embryonic microtissues induced by BMP4 exhibited increased stiffness and viscosity accompanying differentiation, with cytoskeletal tension significantly contributing to multicellular stiffness. Perturbation of the cytoskeleton during ESC differentiation led to modulation of the biomechanical and gene expression profiles, with the resulting cell phenotype and biophysical properties being highly correlated by multivariate analyses. Together, this study elucidates the dynamics of biophysical and biochemical signatures within embryonic microenvironments, with broad implications for monitoring tissue dynamics, modeling pathophysiological and embryonic morphogenesis and directing stem cell patterning and differentiation. PMID:24598818

  6. Niche-dependent development of functional neuronal networks from embryonic stem cell-derived neural populations

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    Siebler Mario

    2009-08-01

    Full Text Available Abstract Background The present work was performed to investigate the ability of two different embryonic stem (ES cell-derived neural precursor populations to generate functional neuronal networks in vitro. The first ES cell-derived neural precursor population was cultivated as free-floating neural aggregates which are known to form a developmental niche comprising different types of neural cells, including neural precursor cells (NPCs, progenitor cells and even further matured cells. This niche provides by itself a variety of different growth factors and extracellular matrix proteins that influence the proliferation and differentiation of neural precursor and progenitor cells. The second population was cultivated adherently in monolayer cultures to control most stringently the extracellular environment. This population comprises highly homogeneous NPCs which are supposed to represent an attractive way to provide well-defined neuronal progeny. However, the ability of these different ES cell-derived immature neural cell populations to generate functional neuronal networks has not been assessed so far. Results While both precursor populations were shown to differentiate into sufficient quantities of mature NeuN+ neurons that also express GABA or vesicular-glutamate-transporter-2 (vGlut2, only aggregate-derived neuronal populations exhibited a synchronously oscillating network activity 2–4 weeks after initiating the differentiation as detected by the microelectrode array technology. Neurons derived from homogeneous NPCs within monolayer cultures did merely show uncorrelated spiking activity even when differentiated for up to 12 weeks. We demonstrated that these neurons exhibited sparsely ramified neurites and an embryonic vGlut2 distribution suggesting an inhibited terminal neuronal maturation. In comparison, neurons derived from heterogeneous populations within neural aggregates appeared as fully mature with a dense neurite network and punctuated

  7. Mesenchymal Cells of the Intestinal Lamina Propria

    Science.gov (United States)

    Powell, D.W.; Pinchuk, I.V.; Saada, J.I.; Chen, Xin; Mifflin, R.C.

    2013-01-01

    The mesenchymal elements of the intestinal lamina propria reviewed here are the myofibroblasts, fibroblasts, mural cells (pericytes) of the vasculature, bone marrow–derived stromal stem cells, smooth muscle of the muscularis mucosae, and smooth muscle surrounding the lymphatic lacteals. These cells share similar marker molecules, origins, and coordinated biological functions previously ascribed solely to subepithelial myofibroblasts. We review the functional anatomy of intestinal mesenchymal cells and describe what is known about their origin in the embryo and their replacement in adults. As part of their putative role in intestinal mucosal morphogenesis, we consider the intestinal stem cell niche. Lastly, we review emerging information about myofibroblasts as nonprofessional immune cells that may be important as an alarm system for the gut and as a participant in peripheral immune tolerance. PMID:21054163

  8. Notch signaling pathway and glioma stem cell niche%Notch信号通路与脑胶质瘤干细胞的niche

    Institute of Scientific and Technical Information of China (English)

    林才厚; 郑宗清; 邱献新; 林志雄

    2013-01-01

    A small fraction of tumor stem cells exist in glioma and play a key role in the tumorigenesis and propagation of glioma.They have a close relationship with their niche that offers structural and functional support.In glioma niche,vascular endothelial cells can provide Notch ligands for cancer stem cells to activate Notch signaling pathway and contact with other signaling pathways,maintaining the tumor stem cell self-renewal and increasing resistance of brain tumor stem cells to radiotherapy.Therefore,Notch signaling pathway is considered to be a new therapeutic target of glioma.%研究表明极少数量肿瘤干细胞存在于脑胶质瘤中,但在其发生发展中起关键作用.脑胶质瘤干细胞与为其提供结构和功能支持的血管niche关系密切.在脑胶质瘤niche中,血管内皮细胞可以提供Notch配体给肿瘤干细胞,激活Notch信号通路,并与其他信号通路构成串话,维持肿瘤干细胞的自我更新,增加脑肿瘤干细胞对放疗的抵抗性.因此,Notch信号通路被认为是脑胶质瘤新的治疗靶点.

  9. Cell organisation in the colonic crypt: a theoretical comparison of the pedigree and niche concepts.

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    Richard C van der Wath

    Full Text Available The intestinal mucosa is a monolayer of rapidly self-renewing epithelial cells which is not only responsible for absorption of water and nutrients into the bloodstream but also acts as a protective barrier against harmful microbes entering the body. New functional epithelial cells are produced from stem cells, and their proliferating progeny. These stem cells are found within millions of crypts (tubular pits spaced along the intestinal tract. The entire intestinal epithelium is replaced every 2-3 days in mice (3-5 days in humans and hence cell production, differentiation, migration and turnover need to be tightly regulated. Malfunctions in this regulation are strongly linked to inflammatory bowel diseases and to the formation of adenomas and ultimately cancerous tumours. Despite a great deal of biological experimentation and observation, precisely how colonic crypts are regulated to produce mature colonocytes remains unclear. To assist in understanding how cell organisation in crypts is achieved, two very different conceptual models of cell behaviour are developed here, referred to as the 'pedigree' and the 'niche' models. The pedigree model proposes that crypt cells are largely preprogrammed and receive minimal prompting from the environment as they move through a routine of cell differentiation and proliferation to become mature colonocytes. The niche model proposes that crypt cells are primarily influenced by the local microenvironments along the crypt, and that predetermined cell behaviour plays a negligible role in their development. In this paper we present a computational model of colonic crypts in the mouse, which enables a comparison of the quality and controllability of mature coloncyte production by crypts operating under these two contrasting conceptual models of crypt regulation.

  10. Limited niche availability suppresses murine intrathymic dendritic-cell development from noncommitted progenitors.

    Science.gov (United States)

    Łyszkiewicz, Marcin; Ziętara, Natalia; Föhse, Lisa; Puchałka, Jacek; Diestelhorst, Jana; Witzlau, Katrin; Prinz, Immo; Schambach, Axel; Krueger, Andreas

    2015-01-15

    The origins of dendritic cells (DCs) and other myeloid cells in the thymus have remained controversial. In this study, we assessed developmental relationships between thymic dendritic cells and thymocytes, employing retrovirus-based cellular barcoding and reporter mice, as well as intrathymic transfers coupled with DC depletion. We demonstrated that a subset of early T-lineage progenitors expressed CX3CR1, a bona fide marker for DC progenitors. However, intrathymic transfers into nonmanipulated mice, as well as retroviral barcoding, indicated that thymic dendritic cells and thymocytes were largely of distinct developmental origin. In contrast, intrathymic transfers after in vivo depletion of DCs resulted in intrathymic development of non-T-lineage cells. In conclusion, our data support a model in which the adoption of T-lineage fate by noncommitted progenitors at steady state is enforced by signals from the thymic microenvironment unless niches promoting alternative lineage fates become available. PMID:25411428

  11. Chick embryo xenograft model reveals a novel perineural niche for human adipose-derived stromal cells

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    Ingrid R. Cordeiro

    2015-09-01

    Full Text Available Human adipose-derived stromal cells (hADSC are a heterogeneous cell population that contains adult multipotent stem cells. Although it is well established that hADSC have skeletal potential in vivo in adult organisms, in vitro assays suggest further differentiation capacity, such as into glia. Thus, we propose that grafting hADSC into the embryo can provide them with a much more instructive microenvironment, allowing the human cells to adopt diverse fates or niches. Here, hADSC spheroids were grafted into either the presumptive presomitic mesoderm or the first branchial arch (BA1 regions of chick embryos. Cells were identified without previous manipulations via human-specific Alu probes, which allows efficient long-term tracing of heterogeneous primary cultures. When grafted into the trunk, in contrast to previous studies, hADSC were not found in chondrogenic or osteogenic territories up to E8. Surprisingly, 82.5% of the hADSC were associated with HNK1+ tissues, such as peripheral nerves. Human skin fibroblasts showed a smaller tropism for nerves. In line with other studies, hADSC also adopted perivascular locations. When grafted into the presumptive BA1, 74.6% of the cells were in the outflow tract, the final goal of cardiac neural crest cells, and were also associated with peripheral nerves. This is the first study showing that hADSC could adopt a perineural niche in vivo and were able to recognize cues for neural crest cell migration of the host. Therefore, we propose that xenografts of human cells into chick embryos can reveal novel behaviors of heterogeneous cell populations, such as response to migration cues.

  12. Anti-inflammatory activity of polyphenolics from açai (Euterpe oleracea Martius) in intestinal myofibroblasts CCD-18Co cells.

    Science.gov (United States)

    Dias, Manoela Maciel dos Santos; Martino, Hércia Stampini Duarte; Noratto, Giuliana; Roque-Andrade, Andrea; Stringheta, Paulo César; Talcott, Stephen; Ramos, Afonso Mota; Mertens-Talcott, Susanne U

    2015-10-01

    The demand for tropical fruits high in polyphenolics including açai (Euterpe oleracea Mart.) has been increasing based on ascribed health benefits and antioxidant properties. This study evaluated the anti-inflammatory activities of açai polyphenolics in human colon myofibroblastic CCD-18Co cells to investigate the suppression of reactive oxygen species (ROS), and mRNA and protein expression of inflammatory proteins. Non-cytotoxic concentrations of açai extract, 1-5 mg gallic acid equivalent L(-1), were selected. The generation of ROS was induced by lipopolysaccharide (LPS) and açai extract partially reversed this effect to 0.53-fold of the LPS-control. Açai extract (5 mg GAE L(-1)) down-regulated LPS-induced mRNA-expression of tumor necrosis factor alpha, TNF-α (to 0.42-fold), cyclooxygenase 2, COX-2 (to 0.61-fold), toll-like receptor-4, TLR-4 (to 0.52-fold), TNF receptor-associated factor 6, TRAF-6 (to 0.64-fold), nuclear factor kappa-B, NF-κB (to 0.76-fold), vascular cell adhesion molecule 1, VCAM-1 (to 0.71-fold) and intercellular adhesion molecule 1, ICAM-1 (to 0.68-fold). The protein levels of COX-2, TLR-4, p-NF-κB and ICAM-1 were induced by LPS and the açai extract partially reversed this effect in a dose-dependent manner. These results suggest the anti-inflammatory effect of açai polyphenolic extract in intestinal cells are at least in part mediated through the inhibition of ROS and the expression of TLR-4 and NF-κB. Results indicate the potential for açai polyphenolics in the prevention of intestinal inflammation. PMID:26243669

  13. SOX9: a stem cell transcriptional regulator of secreted niche signaling factors.

    Science.gov (United States)

    Kadaja, Meelis; Keyes, Brice E; Lin, Mingyan; Pasolli, H Amalia; Genander, Maria; Polak, Lisa; Stokes, Nicole; Zheng, Deyou; Fuchs, Elaine

    2014-02-15

    Hair follicles (HFs) undergo cyclical periods of growth, which are fueled by stem cells (SCs) at the base of the resting follicle. HF-SC formation occurs during HF development and requires transcription factor SOX9. Whether and how SOX9 functions in HF-SC maintenance remain unknown. By conditionally targeting Sox9 in adult HF-SCs, we show that SOX9 is essential for maintaining them. SOX9-deficient HF-SCs still transition from quiescence to proliferation and launch the subsequent hair cycle. However, once activated, bulge HF-SCs begin to differentiate into epidermal cells, which naturally lack SOX9. In addition, as HF-SC numbers dwindle, outer root sheath production is not sustained, and HF downgrowth arrests prematurely. Probing the mechanism, we used RNA sequencing (RNA-seq) to identify SOX9-dependent transcriptional changes and chromatin immunoprecipitation (ChIP) and deep sequencing (ChIP-seq) to identify SOX9-bound genes in HF-SCs. Intriguingly, a large cohort of SOX9-sensitive targets encode extracellular factors, most notably enhancers of Activin/pSMAD2 signaling. Moreover, compromising Activin signaling recapitulates SOX9-dependent defects, and Activin partially rescues them. Overall, our findings reveal roles for SOX9 in regulating adult HF-SC maintenance and suppressing epidermal differentiation in the niche. In addition, our studies expose a role for SCs in coordinating their own behavior in part through non-cell-autonomous signaling within the niche. PMID:24532713

  14. Breast Cancer Cell Colonization of the Human Bone Marrow Adipose Tissue Niche

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    Zach S. Templeton

    2015-12-01

    Full Text Available BACKGROUND/OBJECTIVES: Bone is a preferred site of breast cancer metastasis, suggesting the presence of tissue-specific features that attract and promote the outgrowth of breast cancer cells. We sought to identify parameters of human bone tissue associated with breast cancer cell osteotropism and colonization in the metastatic niche. METHODS: Migration and colonization patterns of MDA-MB-231-fLuc-EGFP (luciferase-enhanced green fluorescence protein and MCF-7-fLuc-EGFP breast cancer cells were studied in co-culture with cancellous bone tissue fragments isolated from 14 hip arthroplasties. Breast cancer cell migration into tissues and toward tissue-conditioned medium was measured in Transwell migration chambers using bioluminescence imaging and analyzed as a function of secreted factors measured by multiplex immunoassay. Patterns of breast cancer cell colonization were evaluated with fluorescence microscopy and immunohistochemistry. RESULTS: Enhanced MDA-MB-231-fLuc-EGFP breast cancer cell migration to bone-conditioned versus control medium was observed in 12/14 specimens (P = .0014 and correlated significantly with increasing levels of the adipokines/cytokines leptin (P = .006 and IL-1β (P = .001 in univariate and multivariate regression analyses. Fluorescence microscopy and immunohistochemistry of fragments underscored the extreme adiposity of adult human bone tissues and revealed extensive breast cancer cell colonization within the marrow adipose tissue compartment. CONCLUSIONS: Our results show that breast cancer cells migrate to human bone tissue-conditioned medium in association with increasing levels of leptin and IL-1β, and colonize the bone marrow adipose tissue compartment of cultured fragments. Bone marrow adipose tissue and its molecular signals may be important but understudied components of the breast cancer metastatic niche.

  15. Bone marrow niche-mediated survival of leukemia stem cells in acute myeloid leukemia: Yin and Yang

    Science.gov (United States)

    Zhou, Hong-Sheng; Carter, Bing Z.; Andreeff, Michael

    2016-01-01

    Acute myeloid leukemia (AML) is characterized by the accumulation of circulating immature blasts that exhibit uncontrolled growth, lack the ability to undergo normal differentiation, and have decreased sensitivity to apoptosis. Accumulating evidence shows the bone marrow (BM) niche is critical to the maintenance and retention of hematopoietic stem cells (HSC), including leukemia stem cells (LSC), and an increasing number of studies have demonstrated that crosstalk between LSC and the stromal cells associated with this niche greatly influences leukemia initiation, progression, and response to therapy. Undeniably, stromal cells in the BM niche provide a sanctuary in which LSC can acquire a drug-resistant phenotype and thereby evade chemotherapy-induced death. Yin and Yang, the ancient Chinese philosophical concept, vividly portrays the intricate and dynamic interactions between LSC and the BM niche. In fact, LSC-induced microenvironmental reprogramming contributes significantly to leukemogenesis. Thus, identifying the critical signaling pathways involved in these interactions will contribute to target optimization and combinatorial drug treatment strategies to overcome acquired drug resistance and prevent relapse following therapy. In this review, we describe some of the critical signaling pathways mediating BM niche-LSC interaction, including SDF1/CXCL12, Wnt/β-catenin, VCAM/VLA-4/NF-κB, CD44, and hypoxia as a newly-recognized physical determinant of resistance, and outline therapeutic strategies for overcoming these resistance factors.

  16. The molecular signature of therapeutic mesenchymal stem cells exposes the architecture of the hematopoietic stem cell niche synapse

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    Mancardi Gianluigi

    2007-03-01

    Full Text Available Abstract Background The hematopoietic stem cells (HSCs niche of the bone marrow is comprised of HSCs, osteoblasts, endothelial cells and a stromal component of non-hematopoietic multipotent cells of mesenchymal origin named "mesenchymal stem cells" (MSCs. Results Here we studied the global transcriptional profile of murine MSCs with immuno-therapeutic potential and compared it with that of 486 publicly available microarray datasets from 12 other mouse tissues or cell types. Principal component analysis and hierarchical clustering identified a unique pattern of gene expression capable of distinctively classifying MSCs from other tissues and cells. We then performed an analysis aimed to identify absolute and relative abundance of transcripts in all cell types. We found that the set of transcripts uniquely expressed by MSCs is enriched in transcription factors and components of the Wnt signaling pathway. The analysis of differentially expressed genes also identified a set of genes specifically involved in the HSC niche and is complemented by functional studies that confirm the findings. Interestingly, some of these genes play a role in the maintenance of HSCs in a quiescent state supporting their survival and preventing them from proliferating and differentiating. We also show that MSCs modulate T cell functions in vitro and, upon in vivo administration, ameliorate experimental autoimmune encephalomyelitis (EAE. Conclusion Altogether, these findings provide novel and important insights on the mechanisms of T cell function regulation by MSCs and help to cement the rationale for their application in the treatment of autoimmune diseases.

  17. Drosophila Follicle Stem Cells are regulated by proliferation and niche adhesion as well as mitochondria and ROS

    OpenAIRE

    Wang, Zhu A.; Huang, Jianhua; Kalderon, Daniel

    2012-01-01

    The mechanisms underlying adult stem cell behavior are likely to be diverse and have not yet been investigated systematically. Here we conducted an unbiased genetic screen using Drosophila ovarian follicle stem cells (FSCs) to probe essential functions regulating self-renewal of epithelial stem cells. Surprisingly, we find that niche adhesion emerge as the most commonly affected essential stem cell property, and that proliferation is critical for stem cell maintenance. We also find that PI3K ...

  18. Immobilized WNT Proteins Act as a Stem Cell Niche for Tissue Engineering

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    Molly Lowndes

    2016-07-01

    Full Text Available The timing, location, and level of WNT signaling are highly regulated during embryonic development and for the maintenance of adult tissues. Consequently the ability to provide a defined and directed source of WNT proteins is crucial to fully understand its role in tissue development and to mimic its activity in vitro. Here we describe a one-step immobilization technique to covalently bind WNT3A proteins as a basal surface with easy storage and long-lasting activity. We show that this platform is able to maintain adult and embryonic stem cells while also being adaptable for 3D systems. Therefore, this platform could be used for recapitulating specific stem cell niches with the goal of improving tissue engineering.

  19. Potential Therapies by Stem Cell-Derived Exosomes in CNS Diseases: Focusing on the Neurogenic Niche

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    Alejandro Luarte

    2016-01-01

    Full Text Available Neurodegenerative disorders are one of the leading causes of death and disability and one of the biggest burdens on health care systems. Novel approaches using various types of stem cells have been proposed to treat common neurodegenerative disorders such as Alzheimer’s Disease, Parkinson’s Disease, or stroke. Moreover, as the secretome of these cells appears to be of greater benefit compared to the cells themselves, the extracellular components responsible for its therapeutic benefit have been explored. Stem cells, as well as most cells, release extracellular vesicles such as exosomes, which are nanovesicles able to target specific cell types and thus to modify their function by delivering proteins, lipids, and nucleic acids. Exosomes have recently been tested in vivo and in vitro as therapeutic conveyors for the treatment of diseases. As such, they could be engineered to target specific populations of cells within the CNS. Considering the fact that many degenerative brain diseases have an impact on adult neurogenesis, we discuss how the modulation of the adult neurogenic niches may be a therapeutic target of stem cell-derived exosomes. These novel approaches should be examined in cellular and animal models to provide better, more effective, and specific therapeutic tools in the future.

  20. Potential Therapies by Stem Cell-Derived Exosomes in CNS Diseases: Focusing on the Neurogenic Niche

    Science.gov (United States)

    Luarte, Alejandro; Bátiz, Luis Federico; Wyneken, Ursula; Lafourcade, Carlos

    2016-01-01

    Neurodegenerative disorders are one of the leading causes of death and disability and one of the biggest burdens on health care systems. Novel approaches using various types of stem cells have been proposed to treat common neurodegenerative disorders such as Alzheimer's Disease, Parkinson's Disease, or stroke. Moreover, as the secretome of these cells appears to be of greater benefit compared to the cells themselves, the extracellular components responsible for its therapeutic benefit have been explored. Stem cells, as well as most cells, release extracellular vesicles such as exosomes, which are nanovesicles able to target specific cell types and thus to modify their function by delivering proteins, lipids, and nucleic acids. Exosomes have recently been tested in vivo and in vitro as therapeutic conveyors for the treatment of diseases. As such, they could be engineered to target specific populations of cells within the CNS. Considering the fact that many degenerative brain diseases have an impact on adult neurogenesis, we discuss how the modulation of the adult neurogenic niches may be a therapeutic target of stem cell-derived exosomes. These novel approaches should be examined in cellular and animal models to provide better, more effective, and specific therapeutic tools in the future. PMID:27195011

  1. NOTCH1 signaling promotes human T-cell acute lymphoblastic leukemia initiating cell regeneration in supportive niches.

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    Wenxue Ma

    Full Text Available BACKGROUND: Leukemia initiating cells (LIC contribute to therapeutic resistance through acquisition of mutations in signaling pathways, such as NOTCH1, that promote self-renewal and survival within supportive niches. Activating mutations in NOTCH1 occur commonly in T cell acute lymphoblastic leukemia (T-ALL and have been implicated in therapeutic resistance. However, the cell type and context specific consequences of NOTCH1 activation, its role in human LIC regeneration, and sensitivity to NOTCH1 inhibition in hematopoietic microenvironments had not been elucidated. METHODOLOGY AND PRINCIPAL FINDINGS: We established humanized bioluminescent T-ALL LIC mouse models transplanted with pediatric T-ALL samples that were sequenced for NOTCH1 and other common T-ALL mutations. In this study, CD34(+ cells from NOTCH1(Mutated T-ALL samples had higher leukemic engraftment and serial transplantation capacity than NOTCH1(Wild-type CD34(+ cells in hematopoietic niches, suggesting that self-renewing LIC were enriched within the NOTCH1(Mutated CD34(+ fraction. Humanized NOTCH1 monoclonal antibody treatment reduced LIC survival and self-renewal in NOTCH1(Mutated T-ALL LIC-engrafted mice and resulted in depletion of CD34(+CD2(+CD7(+ cells that harbor serial transplantation capacity. CONCLUSIONS: These results reveal a functional hierarchy within the LIC population based on NOTCH1 activation, which renders LIC susceptible to targeted NOTCH1 inhibition and highlights the utility of NOTCH1 antibody targeting as a key component of malignant stem cell eradication strategies.

  2. Hyaluronan Controls the Deposition of Fibronectin and Collagen and Modulates TGF-β1 Induction of Lung Myofibroblasts

    OpenAIRE

    Evanko, Stephen P.; Potter-Perigo, Susan; Petty, Loreen J.; Workman, Gail A.; Wight, Thomas N.

    2014-01-01

    The contribution of hyaluronan-dependent pericellular matrix to TGF-β1-driven induction and maintenance of myofibroblasts is not understood. Hyaluronan is an extracellular matrix (ECM) glycosaminoglycan important in cell adhesion, proliferation and migration, and is implicated in myofibroblast formation and maintenance. Reduced turnover of hyaluronan has been linked to differentiation of myofibroblasts and potentiation of lung fibrosis. Fibronectin is a fibril forming adhesive glycoprotein th...

  3. Monocytes increase human cardiac myofibroblast-mediated extracellular matrix remodeling through TGF-β1.

    Science.gov (United States)

    Mewhort, Holly E M; Lipon, Brodie D; Svystonyuk, Daniyil A; Teng, Guoqi; Guzzardi, David G; Silva, Claudia; Yong, V Wee; Fedak, Paul W M

    2016-03-15

    Following myocardial infarction (MI), cardiac myofibroblasts remodel the extracellular matrix (ECM), preventing mechanical complications. However, prolonged myofibroblast activity leads to dysregulation of the ECM, maladaptive remodeling, fibrosis, and heart failure (HF). Chronic inflammation is believed to drive persistent myofibroblast activity; however, the mechanisms are unclear. We assessed the influence of peripheral blood monocytes on human cardiac myofibroblast activity in a three-dimensional (3D) ECM microenvironment. Human cardiac myofibroblasts isolated from surgical biopsies of the right atrium and left ventricle were seeded into 3D collagen matrices. Peripheral blood monocytes were isolated from healthy human donors and cocultured with myofibroblasts. Monocytes increased myofibroblast activity measured by collagen gel contraction (baseline: 57.6 ± 5.9% vs. coculture: 65.2 ± 7.1% contraction; P < 0.01) and increased local ECM remodeling quantified by confocal microscopy. Under coculture conditions that allow indirect cellular interaction via paracrine factors but prevent direct cell-cell contact, monocytes had minimal effects on myofibroblast activity (17.9 ± 11.1% vs. 6.4 ± 7.0% increase, respectively; P < 0.01). When cells were cultured under direct contact conditions, multiplex analysis of the coculture media revealed an increase in the paracrine factors TGF-β1 and matrix metalloproteinase 9 compared with baseline (122.9 ± 10.1 pg/ml and 3,496.0 ± 190.4 pg/ml, respectively, vs. 21.5 ± 16.3 pg/ml and 183.3 ± 43.9 pg/ml; P < 0.001). TGF-β blockade abolished the monocyte-induced increase in cardiac myofibroblast activity. These data suggest that direct cell-cell interaction between monocytes and cardiac myofibroblasts stimulates TGF-β-mediated myofibroblast activity and increases remodeling of local matrix. Peripheral blood monocyte interaction with human cardiac myofibroblasts stimulates myofibroblast activity through release of TGF-β1

  4. WOX5 Suppresses CYCLIN D Activity to Establish Quiescence at the Center of the Root Stem Cell Niche

    OpenAIRE

    Forzani, C.; Aichinger, E.; Willemsen, V; Murray, J. A.

    2014-01-01

    In Arabidopsis, stem cells maintain the provision of new cells for root growth. They surround a group of slowly dividing cells named the quiescent center (QC), and, together, they form the stem cell niche (SCN). The QC acts as the signaling center of the SCN, repressing differentiation of the surrounding stem cells [1] and providing a pool of cells able to replace damaged stem cells [2, 3]. Maintenance of the stem cells depends on the transcription factor WUSCHEL-RELATED HOMEOBOX 5 (WOX5), wh...

  5. WOX5 Suppresses CYCLIN D Activity to Establish Quiescence at the Center of the Root Stem Cell Niche

    OpenAIRE

    Forzani, Celine; Aichinger, Ernst; Sornay, Emily; Willemsen, Viola; Laux, Thomas; Dewitte, Walter; Murray, James A.H.

    2014-01-01

    Summary In Arabidopsis, stem cells maintain the provision of new cells for root growth. They surround a group of slowly dividing cells named the quiescent center (QC), and, together, they form the stem cell niche (SCN). The QC acts as the signaling center of the SCN, repressing differentiation of the surrounding stem cells [1] and providing a pool of cells able to replace damaged stem cells [2, 3]. Maintenance of the stem cells depends on the transcription factor WUSCHEL-RELATED HOMEOBOX 5 (W...

  6. Signaling Networks among Stem Cell Precursors, Transit-Amplifying Progenitors, and their Niche in Developing Hair Follicles.

    Science.gov (United States)

    Rezza, Amélie; Wang, Zichen; Sennett, Rachel; Qiao, Wenlian; Wang, Dongmei; Heitman, Nicholas; Mok, Ka Wai; Clavel, Carlos; Yi, Rui; Zandstra, Peter; Ma'ayan, Avi; Rendl, Michael

    2016-03-29

    The hair follicle (HF) is a complex miniorgan that serves as an ideal model system to study stem cell (SC) interactions with the niche during growth and regeneration. Dermal papilla (DP) cells are required for SC activation during the adult hair cycle, but signal exchange between niche and SC precursors/transit-amplifying cell (TAC) progenitors that regulates HF morphogenetic growth is largely unknown. Here we use six transgenic reporters to isolate 14 major skin and HF cell populations. With next-generation RNA sequencing, we characterize their transcriptomes and define unique molecular signatures. SC precursors, TACs, and the DP niche express a plethora of ligands and receptors. Signaling interaction network analysis reveals a bird's-eye view of pathways implicated in epithelial-mesenchymal interactions. Using a systematic tissue-wide approach, this work provides a comprehensive platform, linked to an interactive online database, to identify and further explore the SC/TAC/niche crosstalk regulating HF growth. PMID:27009580

  7. Genetic lineage tracing defines myofibroblast origin and function in the injured heart.

    Science.gov (United States)

    Kanisicak, Onur; Khalil, Hadi; Ivey, Malina J; Karch, Jason; Maliken, Bryan D; Correll, Robert N; Brody, Matthew J; J Lin, Suh-Chin; Aronow, Bruce J; Tallquist, Michelle D; Molkentin, Jeffery D

    2016-01-01

    Cardiac fibroblasts convert to myofibroblasts with injury to mediate healing after acute myocardial infarction (MI) and to mediate long-standing fibrosis with chronic disease. Myofibroblasts remain a poorly defined cell type in terms of their origins and functional effects in vivo. Here we generate Postn (periostin) gene-targeted mice containing a tamoxifen-inducible Cre for cellular lineage-tracing analysis. This Postn allele identifies essentially all myofibroblasts within the heart and multiple other tissues. Lineage tracing with four additional Cre-expressing mouse lines shows that periostin-expressing myofibroblasts in the heart derive from tissue-resident fibroblasts of the Tcf21 lineage, but not endothelial, immune/myeloid or smooth muscle cells. Deletion of periostin(+) myofibroblasts reduces collagen production and scar formation after MI. Periostin-traced myofibroblasts also revert back to a less-activated state upon injury resolution. Our results define the myofibroblast as a periostin-expressing cell type necessary for adaptive healing and fibrosis in the heart, which arises from Tcf21(+) tissue-resident fibroblasts. PMID:27447449

  8. Differentiation of tumour-promoting stromal myofibroblasts by cancer exosomes.

    Science.gov (United States)

    Webber, J P; Spary, L K; Sanders, A J; Chowdhury, R; Jiang, W G; Steadman, R; Wymant, J; Jones, A T; Kynaston, H; Mason, M D; Tabi, Z; Clayton, A

    2015-01-15

    Activation of myofibroblast rich stroma is a rate-limiting step essential for cancer progression. The responsible factors are not fully understood, but TGFβ1 is probably critical. A proportion of TGFβ1 is associated with extracellular nano-vesicles termed exosomes, secreted by carcinoma cells, and the relative importance of soluble and vesicular TGFβ in stromal activation is presented. Prostate cancer exosomes triggered TGFβ1-dependent fibroblast differentiation, to a distinctive myofibroblast phenotype resembling stromal cells isolated from cancerous prostate tissue; supporting angiogenesis in vitro and accelerating tumour growth in vivo. Myofibroblasts generated using soluble TGFβ1 were not pro-angiogenic or tumour-promoting. Cleaving heparan sulphate side chains from the exosome surface had no impact on TGFβ levels yet attenuated SMAD-dependent signalling and myofibroblastic differentiation. Eliminating exosomes from the cancer cell secretome, targeting Rab27a, abolished differentiation and lead to failure in stroma-assisted tumour growth in vivo. Exosomal TGFβ1 is therefore required for the formation of tumour-promoting stroma. PMID:24441045

  9. Identification of a novel agrin-dependent pathway in cell signaling and adhesion within the erythroid niche.

    Science.gov (United States)

    Anselmo, A; Lauranzano, E; Soldani, C; Ploia, C; Angioni, R; D'amico, G; Sarukhan, A; Mazzon, C; Viola, A

    2016-08-01

    Establishment of cell-cell adhesion is crucial in embryonic development as well as within the stem cell niches of an adult. Adhesion between macrophages and erythroblasts is required for the formation of erythroblastic islands, specialized niches where erythroblasts proliferate and differentiate to produce red blood cells throughout life. The Eph family is the largest known family of receptor tyrosine kinases (RTKs) and controls cell adhesion, migration, invasion and morphology by modulating integrin and adhesion molecule activity and by modifying the actin cytoskeleton. Here, we identify the proteoglycan agrin as a novel regulator of Eph receptor signaling and characterize a novel mechanism controlling cell-cell adhesion and red cell development within the erythroid niche. We demonstrate that agrin induces clustering and activation of EphB1 receptors on developing erythroblasts, leading to the activation of α5β1 integrins. In agreement, agrin knockout mice display severe anemia owing to defective adhesion to macrophages and impaired maturation of erythroid cells. These results position agrin-EphB1 as a novel key signaling couple regulating cell adhesion and erythropoiesis. PMID:26990660

  10. Thymic regulatory T cell niche size is dictated by limiting interleukin 2 from antigen-bearing dendritic cells and feedback competition

    OpenAIRE

    Weist, Brian M.; Kurd, Nadia; Boussier, Jeremy; Chan, Shiao Wei; Robey, Ellen A.

    2015-01-01

    Thymic regulatory T (Treg) cell production requires interleukin 2 (IL-2) and agonist TCR ligands, and is controlled by competition for a limited developmental niche, but the thymic sources of IL-2 and the factors that limit access to the niche are poorly understood. Here we show that IL-2 produced by antigen-bearing dendritic cells plays a key role in Treg cell development, and that existing Treg cells limit new Treg cell development by competing for IL-2. . Our data suggest that antigen-pres...

  11. Eosinophils and megakaryocytes support the early growth of murine MOPC315 myeloma cells in their bone marrow niches.

    Directory of Open Access Journals (Sweden)

    David Wong

    Full Text Available Multiple myeloma is a bone marrow plasma cell tumor which is supported by the external growth factors APRIL and IL-6, among others. Recently, we identified eosinophils and megakaryocytes to be functional components of the micro-environmental niches of benign bone marrow plasma cells and to be important local sources of these cytokines. Here, we investigated whether eosinophils and megakaryocytes also support the growth of tumor plasma cells in the MOPC315.BM model for multiple myeloma. As it was shown for benign plasma cells and multiple myeloma cells, IL-6 and APRIL also supported MOPC315.BM cell growth in vitro, IL-5 had no effect. Depletion of eosinophils in vivo by IL-5 blockade led to a reduction of the early myeloma load. Consistent with this, myeloma growth in early stages was retarded in eosinophil-deficient ΔdblGATA-1 mice. Late myeloma stages were unaffected, possibly due to megakaryocytes compensating for the loss of eosinophils, since megakaryocytes were found to be in contact with myeloma cells in vivo and supported myeloma growth in vitro. We conclude that eosinophils and megakaryocytes in the niches for benign bone marrow plasma cells support the growth of malignant plasma cells. Further investigations are required to test whether perturbation of these niches represents a potential strategy for the treatment of multiple myeloma.

  12. Chronic expression of Ski induces apoptosis and represses autophagy in cardiac myofibroblasts.

    Science.gov (United States)

    Zeglinski, Matthew R; Davies, Jared J L; Ghavami, Saeid; Rattan, Sunil G; Halayko, Andrew J; Dixon, Ian M C

    2016-06-01

    Inappropriate cardiac interstitial remodeling is mediated by activated phenoconverted myofibroblasts. The synthesis of matrix proteins by these cells is triggered by both chemical and mechanical stimuli. Ski is a repressor of TGFβ1/Smad signaling and has been described as possessing anti-fibrotic properties within the myocardium. We hypothesized that overexpression of Ski in myofibroblasts will induce an apoptotic response, which may either be supported or opposed by autophagic flux. We used primary myofibroblasts (activated fibroblasts) which were sourced from whole heart preparations that were only passaged once. We found that overexpression of Ski results in distinct morphological and biochemical changes within primary cardiac myofibroblasts associated with apoptosis. Ski treatment was associated with the expression of pro-apoptotic factors such as Bax, caspase-7, and -9. Our results indicate that Ski triggers a pro-death mechanism in primary rat cardiac myofibroblasts that is mediated through the intrinsic apoptotic pathway. Myofibroblast survival is prolonged by an autophagic response, as the dataset indicate that apoptosis is hastened when autophagy is inhibited. We suggest that the apoptotic death response of myofibroblasts is working in parallel with the previously observed anti-fibrotic properties of Ski within this cell type. As myofibroblasts are the sole mediators of matrix expansion in heart failure, we suggest that Ski, or a putative Ski-mimetic, may induce graded apoptosis in myofibroblasts within the failing heart and may be a novel therapeutic approach towards controlling cardiac fibrosis. Future studies are needed to examine the potential effects of Ski overexpression on other cell types in the heart. PMID:27039037

  13. Single-cell and coupled GRN models of cell patterning in the Arabidopsis thaliana root stem cell niche

    Directory of Open Access Journals (Sweden)

    Alvarez-Buylla Elena R

    2010-10-01

    Full Text Available Abstract Background Recent experimental work has uncovered some of the genetic components required to maintain the Arabidopsis thaliana root stem cell niche (SCN and its structure. Two main pathways are involved. One pathway depends on the genes SHORTROOT and SCARECROW and the other depends on the PLETHORA genes, which have been proposed to constitute the auxin readouts. Recent evidence suggests that a regulatory circuit, composed of WOX5 and CLE40, also contributes to the SCN maintenance. Yet, we still do not understand how the niche is dynamically maintained and patterned or if the uncovered molecular components are sufficient to recover the observed gene expression configurations that characterize the cell types within the root SCN. Mathematical and computational tools have proven useful in understanding the dynamics of cell differentiation. Hence, to further explore root SCN patterning, we integrated available experimental data into dynamic Gene Regulatory Network (GRN models and addressed if these are sufficient to attain observed gene expression configurations in the root SCN in a robust and autonomous manner. Results We found that an SCN GRN model based only on experimental data did not reproduce the configurations observed within the root SCN. We developed several alternative GRN models that recover these expected stable gene configurations. Such models incorporate a few additional components and interactions in addition to those that have been uncovered. The recovered configurations are stable to perturbations, and the models are able to recover the observed gene expression profiles of almost all the mutants described so far. However, the robustness of the postulated GRNs is not as high as that of other previously studied networks. Conclusions These models are the first published approximations for a dynamic mechanism of the A. thaliana root SCN cellular pattering. Our model is useful to formally show that the data now available are not

  14. Purinergic signalling in a latent stem cell niche of the rat spinal cord.

    Science.gov (United States)

    Marichal, Nicolás; Fabbiani, Gabriela; Trujillo-Cenóz, Omar; Russo, Raúl E

    2016-06-01

    The ependyma of the spinal cord harbours stem cells which are activated by traumatic spinal cord injury. Progenitor-like cells in the central canal (CC) are organized in spatial domains. The cells lining the lateral aspects combine characteristics of ependymocytes and radial glia (RG) whereas in the dorsal and ventral poles, CC-contacting cells have the morphological phenotype of RG and display complex electrophysiological phenotypes. The signals that may affect these progenitors are little understood. Because ATP is massively released after spinal cord injury, we hypothesized that purinergic signalling plays a part in this spinal stem cell niche. We combined immunohistochemistry, in vitro patch-clamp whole-cell recordings and Ca(2+) imaging to explore the effects of purinergic agonists on ependymal progenitor-like cells in the neonatal (P1-P6) rat spinal cord. Prolonged focal application of a high concentration of ATP (1 mM) induced a slow inward current. Equimolar concentrations of BzATP generated larger currents that reversed close to 0 mV, had a linear current-voltage relationship and were blocked by Brilliant Blue G, suggesting the presence of functional P2X7 receptors. Immunohistochemistry showed that P2X7 receptors were expressed around the CC and the processes of RG. BzATP also generated Ca(2+) waves in RG that were triggered by Ca(2+) influx and propagated via Ca(2+) release from internal stores through activation of ryanodine receptors. We speculate that the intracellular Ca(2+) signalling triggered by P2X7 receptor activation may be an epigenetic mechanism to modulate the behaviour of progenitors in response to ATP released after injury. PMID:26988236

  15. Identification of the Niche and Phenotype of the First Human Hematopoietic Stem Cells

    Directory of Open Access Journals (Sweden)

    Andrejs Ivanovs

    2014-04-01

    Full Text Available In various vertebrate species, the dorsal aorta (Ao is the site of specification of adult hematopoietic stem cells (HSCs. It has been observed that the upregulation of essential hematopoietic transcription factors and the formation of specific intra-aortic hematopoietic cell clusters occur predominantly in the ventral domain of the Ao (AoV. In the mouse, the first HSCs emerge in the AoV. Here, we demonstrate that in the human embryo the first definitive HSCs also emerge asymmetrically and are localized to the AoV, which thus identifies a functional niche for developing human HSCs. Using magnetic cell separation and xenotransplantations, we show that the first human HSCs are CD34+VE-cadherin+CD45+C-KIT+THY-1+Endoglin+RUNX1+CD38−/loCD45RA−. This population harbors practically all committed hematopoietic progenitors and is underrepresented in the dorsal domain of the Ao (AoD and urogenital ridges (UGRs. The present study provides a foundation for analysis of molecular mechanisms underpinning embryonic specification of human HSCs.

  16. FGF7 supports hematopoietic stem and progenitor cells and niche-dependent myeloblastoma cells via autocrine action on bone marrow stromal cells in vitro

    International Nuclear Information System (INIS)

    Highlights: •FGF7 is downregulated in MED1-deficient mesenchymal cells. •FGF7 produced by mesenchymal stromal cells is a novel hematopoietic niche molecule. •FGF7 supports hematopoietic progenitor cells and niche-dependent leukemia cells. •FGF7 activates FGFR2IIIb of bone marrow stromal cells in an autocrine manner. •FGF7 indirectly acts on hematopoietic cells lacking FGFR2IIIb via stromal cells. -- Abstract: FGF1 and FGF2 support hematopoietic stem and progenitor cells (HSPCs) under stress conditions. In this study, we show that fibroblast growth factor (FGF7) may be a novel niche factor for HSPC support and leukemic growth. FGF7 expression was attenuated in mouse embryonic fibroblasts (MEFs) deficient for the MED1 subunit of the Mediator transcriptional coregulator complex. When normal mouse bone marrow (BM) cells were cocultured with Med1+/+ MEFs or BM stromal cells in the presence of anti-FGF7 antibody, the growth of BM cells and the number of long-time culture-initiating cells (LTC-ICs) decreased significantly. Anti-FGF7 antibody also attenuated the proliferation and cobblestone formation of MB1 stromal cell-dependent myeloblastoma cells. The addition of recombinant FGF7 to the coculture of BM cells and Med1−/− MEFs increased BM cells and LTC-ICs. FGF7 and its cognate receptor, FGFR2IIIb, were undetectable in BM cells, but MEFs and BM stromal cells expressed both. FGF7 activated downstream targets of FGFR2IIIb in Med1+/+ and Med1−/− MEFs and BM stromal cells. Taken together, we propose that FGF7 supports HSPCs and leukemia-initiating cells indirectly via FGFR2IIIb expressed on stromal cells

  17. FGF7 supports hematopoietic stem and progenitor cells and niche-dependent myeloblastoma cells via autocrine action on bone marrow stromal cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Ishino, Ruri; Minami, Kaori; Tanaka, Satowa [Laboratory of Hematology, Division of Medical Biophysics, Kobe University Graduate School of Health Sciences, 7-10-2 Tomogaoka, Suma-ku, Kobe 654-0142 (Japan); Nagai, Mami [Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 159-8555 (Japan); Matsui, Keiji; Hasegawa, Natsumi [Laboratory of Hematology, Division of Medical Biophysics, Kobe University Graduate School of Health Sciences, 7-10-2 Tomogaoka, Suma-ku, Kobe 654-0142 (Japan); Roeder, Robert G. [Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065 (United States); Asano, Shigetaka [Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 159-8555 (Japan); Ito, Mitsuhiro, E-mail: itomi@med.kobe-u.ac.jp [Laboratory of Hematology, Division of Medical Biophysics, Kobe University Graduate School of Health Sciences, 7-10-2 Tomogaoka, Suma-ku, Kobe 654-0142 (Japan); Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065 (United States); Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 159-8555 (Japan); Department of Family and Community Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 654-0142 (Japan)

    2013-10-11

    Highlights: •FGF7 is downregulated in MED1-deficient mesenchymal cells. •FGF7 produced by mesenchymal stromal cells is a novel hematopoietic niche molecule. •FGF7 supports hematopoietic progenitor cells and niche-dependent leukemia cells. •FGF7 activates FGFR2IIIb of bone marrow stromal cells in an autocrine manner. •FGF7 indirectly acts on hematopoietic cells lacking FGFR2IIIb via stromal cells. -- Abstract: FGF1 and FGF2 support hematopoietic stem and progenitor cells (HSPCs) under stress conditions. In this study, we show that fibroblast growth factor (FGF7) may be a novel niche factor for HSPC support and leukemic growth. FGF7 expression was attenuated in mouse embryonic fibroblasts (MEFs) deficient for the MED1 subunit of the Mediator transcriptional coregulator complex. When normal mouse bone marrow (BM) cells were cocultured with Med1{sup +/+} MEFs or BM stromal cells in the presence of anti-FGF7 antibody, the growth of BM cells and the number of long-time culture-initiating cells (LTC-ICs) decreased significantly. Anti-FGF7 antibody also attenuated the proliferation and cobblestone formation of MB1 stromal cell-dependent myeloblastoma cells. The addition of recombinant FGF7 to the coculture of BM cells and Med1{sup −/−} MEFs increased BM cells and LTC-ICs. FGF7 and its cognate receptor, FGFR2IIIb, were undetectable in BM cells, but MEFs and BM stromal cells expressed both. FGF7 activated downstream targets of FGFR2IIIb in Med1{sup +/+} and Med1{sup −/−} MEFs and BM stromal cells. Taken together, we propose that FGF7 supports HSPCs and leukemia-initiating cells indirectly via FGFR2IIIb expressed on stromal cells.

  18. Hematopoietic Stem Cell Activity Is Regulated by Pten Phosphorylation Through a Niche-Dependent Mechanism.

    Science.gov (United States)

    Li, Jing; Zhang, Jun; Tang, Minghui; Xin, Junping; Xu, Yan; Volk, Andrew; Hao, Caiqin; Hu, Chenglong; Sun, Jiewen; Wei, Wei; Cao, Quichan; Breslin, Peter; Zhang, Jiwang

    2016-08-01

    The phosphorylated form of Pten (p-Pten) is highly expressed in >70% of acute myeloid leukemia samples. However, the role of p-Pten in normal and abnormal hematopoiesis has not been studied. We found that Pten protein levels are comparable among long-term (LT) hematopoietic stem cells (HSCs), short-term (ST) HSCs, and multipotent progenitors (MPPs); however, the levels of p-Pten are elevated during the HSC-to-MPP transition. To study whether p-Pten is involved in regulating self-renewal and differentiation in HSCs, we compared the effects of overexpression of p-Pten and nonphosphorylated Pten (non-p-Pten) on the hematopoietic reconstitutive capacity (HRC) of HSCs. We found that overexpression of non-p-Pten enhances the LT-HRC of HSCs, whereas overexpression of p-Pten promotes myeloid differentiation and compromises the LT-HRC of HSCs. Such phosphorylation-regulated Pten functioning is mediated by repressing the cell:cell contact-induced activation of Fak/p38 signaling independent of Pten's lipid phosphatase activity because both p-Pten and non-p-Pten have comparable activity in repressing PI3K/Akt signaling. Our studies suggest that, in addition to repressing PI3K/Akt/mTor signaling, non-p-Pten maintains HSCs in bone marrow niches via a cell-contact inhibitory mechanism by inhibiting Fak/p38 signaling-mediated proliferation and differentiation. In contrast, p-Pten promotes the proliferation and differentiation of HSCs by enhancing the cell contact-dependent activation of Src/Fak/p38 signaling. Stem Cells 2016;34:2130-2144. PMID:27096933

  19. Transcriptome comparison of distinct osteolineage subsets in the hematopoietic stem cell niche using a triple fluorescent transgenic mouse model.

    Science.gov (United States)

    Yu, Vionnie W C; Lymperi, Stefania; Ferraro, Francesca; Scadden, David T

    2015-09-01

    The bone marrow niche is recognized as a central player in maintaining and regulating the behavior of hematopoietic stem and progenitor cells. Specific gain-of and loss-of function experiments perturbing a range of osteolineage cells or their secreted proteins had been shown to affect stem cell maintenance (Calvi et al, 2003 [1]; Stier et al., 2005 [2]; Zhang et al., 2003 [3]; Nilsson et al., 2005 [4]; Greenbaum et al., 2013 [5]) and engraftment (Adam et al., 2006, 2009 [6,7]). We used specific in vivo cell deletion approaches to dissect the niche cell-parenchymal cell dependency in a complex bone marrow microenvironment. Endogenous deletion of osteocalcin-expressing (Ocn(+)) cells led to a loss of T immune cells (Yu et al., 2015 [8]. Ocn(+) cells express the Notch ligand DLL4 to communicate with T-competent progenitors, and thereby ensuring T precursor production and expression of chemotactic molecules on their cell surface for subsequent thymic seeding. In contrast, depletion of osterix-expressing (Osx(+)) osteoprogenitors led to reduced B immune cells. These distinct hematopoietic phenotypes suggest specific pairing of mesenchymal niche cells and parenchymal hematopoietic cells in the bone marrow to create unique functional units to support hematopoiesis. Here, we present the global gene expression profiles of these osteolineage subtypes utilizing a triple fluorescent transgenic mouse model (OsxCre(+);Rosa-mCh(+);Ocn:Topaz(+)) that labels Osx(+) cells red, Ocn(+) cells green, and Osx(+) Ocn(+) cells yellow. This system allows isolation of distinct osteolineage subsets within the same animal by flow cytometry. Array data that have been described in our study [8] are also publically available from NCBI Gene Expression Omnibus (GEO) with the accession number GSE66042. Differences in gene expression may correlate with functional difference in supporting hematopoiesis. PMID:26484277

  20. Inflammatory Myofibroblastic Tumor Presenting as a Pancreatic Mass: A Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Raimondo M

    2004-09-01

    Full Text Available CONTEXT: Inflammatory myofibroblastic tumor is a distinctive lesion of unknown etiology. It has generally been considered a rare benign pseudosarcomatous lesion of admixed inflammatory infiltrates with myofibroblastic spindle cells. Although original case descriptions focused on the pulmonary system, it is now recognized that virtually any anatomic location can be involved. However, an inflammatory myofibroblastic tumor located in the pancreas is rare. CASE REPORT: We report a case of an asymptomatic 70-year-old Caucasian man with a 3.8 cm inflammatory myofibroblastic tumor located in the tail of the pancreas which was discovered incidentally on a computed tomography scan of the abdomen. Endoscopic ultrasonography with fine needle aspiration was negative for malignancy. However, because of worrisome radiographic features, a distal pancreatectomy with splenectomy was performed. The pathology revealed an inflammatory myofibroblastic tumor with focal extension into the peripancreatic soft tissues, but with negative surgical margins. The patient has been followed for 10 months without evidence of recurrence. CONCLUSIONS: To date, there have been only 25 cases of inflammatory myofibroblastic tumor located in the pancreas reported in the English language scientific literature. Even with multimodal pre-surgical investigation, it can be extremely difficult to differentiate inflammatory myofibroblastic tumor from pancreatic malignancies. Most cases require surgical exploration and complete resection to obtain an accurate diagnosis. A review of published case reports is also presented.

  1. One size does not fit all: developing a cell-specific niche for in vitro study of cell behavior.

    Science.gov (United States)

    Marinkovic, Milos; Block, Travis J; Rakian, Rubie; Li, Qihong; Wang, Exing; Reilly, Matthew A; Dean, David D; Chen, Xiao-Dong

    2016-01-01

    For more than 100years, cells and tissues have been studied in vitro using glass and plastic surfaces. Over the last 10-20years, a great body of research has shown that cells are acutely sensitive to their local environment (extracellular matrix, ECM) which contains both chemical and physical cues that influence cell behavior. These observations suggest that modern cell culture systems, using tissue culture polystyrene (TCP) surfaces, may fail to reproduce authentic cell behavior in vitro, resulting in "artificial outcomes." In the current study, we use bone marrow (BM)- and adipose (AD)-derived stromal cells to prepare BM-ECM and AD-ECM, which are decellularized after synthesis by the cells, to mimic the cellular niche for each of these tissues. Each ECM was characterized for its ability to affect BM- and AD-mesenchymal stem cell (MSC) proliferation, as well as proliferation of three cancer cell lines (HeLa, MCF-7, and MDA-MB-231), modulate cell spreading, and direct differentiation relative to standard TCP surfaces. We found that both ECMs promoted the proliferation of MSCs, but that this effect was enhanced when the tissue-origin of the cells matched that of the ECM (i.e. BM-ECM promoted the proliferation of BM-MSCs over AD-MSCs, and vice versa). Moreover, BM- and AD-ECM were shown to preferentially direct MSC differentiation towards either osteogenic or adipogenic lineage, respectively, suggesting that the effects of the ECM were tissue-specific. Further, each ECM influenced cell morphology (i.e. circularity), irrespective of the origin of the MSCs, lending more support to the idea that effects were tissue specific. Interestingly, unlike MSCs, these ECMs did not promote the proliferation of the cancer cells. In an effort to further understand how these three culture substrates influence cell behavior, we evaluated the chemical (protein composition) and physical properties (architecture and mechanical) of the two ECMs. While many structural proteins (e

  2. The Drosophila BCL6 homolog Ken and Barbie promotes somatic stem cell self-renewal in the testis niche.

    Science.gov (United States)

    Issigonis, Melanie; Matunis, Erika

    2012-08-15

    Stem cells sustain tissue regeneration by their remarkable ability to replenish the stem cell pool and to generate differentiating progeny. Signals from local microenvironments, or niches, control stem cell behavior. In the Drosophila testis, a group of somatic support cells called the hub creates a stem cell niche by locally activating the Janus Kinase-Signal Transducer and Activator of Transcription (JAK-STAT) pathway in two adjacent types of stem cells: germline stem cells (GSCs) and somatic cyst stem cells (CySCs). Here, we find that ken and barbie (ken) is autonomously required for the self-renewal of CySCs but not GSCs. Furthermore, Ken misexpression in the CySC lineage induces the cell-autonomous self-renewal of somatic cells as well as the nonautonomous self-renewal of germ cells outside the niche. Thus, Ken, like Stat92E and its targets ZFH1 (Leatherman and Dinardo, 2008) and Chinmo (Flaherty et al., 2010), is necessary and sufficient for CySC renewal. However, ken is not a JAK-STAT target in the testis, but instead acts in parallel to Stat92E to ensure CySC self-renewal. Ken represses a subset of Stat92E targets in the embryo (Arbouzova et al., 2006) suggesting that Ken maintains CySCs by repressing differentiation factors. In support of this hypothesis, we find that the global JAK-STAT inhibitor Protein tyrosine phosphatase 61F (Ptp61F) is a JAK-STAT target in the testis that is repressed by Ken. Together, our work demonstrates that Ken has an important role in the inhibition of CySC differentiation. Studies of ken may inform our understanding of its vertebrate orthologue B-Cell Lymphoma 6 (BCL6) and how misregulation of this oncogene leads to human lymphomas. PMID:22580161

  3. Pediatric Fibroblastic and Myofibroblastic Tumors: A Pictorial Review.

    Science.gov (United States)

    Sargar, Kiran M; Sheybani, Elizabeth F; Shenoy, Archana; Aranake-Chrisinger, John; Khanna, Geetika

    2016-01-01

    Pediatric fibroblastic and myofibroblastic tumors are a relatively common group of soft-tissue proliferations that are associated with a wide spectrum of clinical behavior. These tumors have been divided into the following categories on the basis of their biologic behavior: benign (eg, myositis ossificans, myofibroma, fibromatosis colli), intermediate-locally aggressive (eg, lipofibromatosis, desmoid fibroma), intermediate-rarely metastasizing (eg, inflammatory myofibroblastic tumors, infantile fibrosarcoma, low-grade myofibroblastic sarcoma), and malignant (eg, fibromyxoid sarcoma, adult fibrosarcoma). Imaging has a key role in the evaluation of lesion origin, extent, and involvement with adjacent structures, and in the treatment management and postresection surveillance of these tumors. The imaging findings of these tumors are often nonspecific. However, certain imaging features, such as low or intermediate signal intensity on T2-weighted magnetic resonance images and extension along fascial planes, support the diagnosis of a fibroblastic or myofibroblastic tumor. In addition, certain tumors have characteristic imaging findings (eg, multiple subcutaneous or intramuscular lesions in infantile myofibromatosis, plaquelike growth pattern of Gardner fibroma, presence of adipose tissue in lipofibromatosis) or characteristic clinical manifestations (eg, great toe malformations in fibrodysplasia ossificans fibroma, neonatal torticollis in fibromatosis colli) that suggest the correct diagnosis. Knowledge of the syndrome associations of some of these tumors-for example, the association between familial adenomatous polyposis syndrome and both Gardner fibroma and desmoid fibromatosis, and that between nevoid basal cell carcinoma syndrome and cardiac fibroma-further facilitate a diagnosis. The recognition of key imaging findings can help guide treatment management and help avoid unnecessary intervention in cases of benign lesions such as myositis ossificans and fibromatosis

  4. Myofibroblasts and colonic anastomosis healing in Wistar rats

    Directory of Open Access Journals (Sweden)

    Vasiliadou Kalliopi

    2011-03-01

    Full Text Available Abstract Background The myofibroblasts play a central role in wound healing throughout the body. The process of wound healing in the colon was evaluated with emphasis on the role of myofibroblasts. Methods One hundred male Wistar rats weighing 274 ± 9.1 g (mean age: 3.5 months were used. A left colonic segment was transected and the colon was re-anastomosed. Animals were randomly divided into two groups. The first group experimental animals (n = 50 were sacrificed on postoperative day 3, while the second group rats (n = 50 were sacrificed on postoperative day 7. Healing of colonic anastomosis was studied in terms of anastomotic bursting pressure, as well as myofibroblastic reaction and expression of α-smooth muscle actin (α-SMA, adhesion formation, inflammatory reaction and neovascularization. Results The mean anastomotic bursting pressure increased from 20.6 ± 3.5 mmHg on the 3rd postoperative day to 148.8 ± 9.6 Hg on the 7th postoperative day. Adhesion formation was increased on the 7th day, as compared to the 3rd day. In addition, the myofibroblastic reaction was more profound on the 7th postoperative day in comparison with the 3rd postoperative day. The staining intensity for α-SMA was progressive from the 3rd to the 7th postoperative day. On the 7th day the α-SMA staining in the myofibroblats reached the level of muscular layer cells. Conclusions Our study emphasizes the pivotal role of myofibroblasts in the process of colonic anastomosis healing. The findings provide an explanation for the reduction in the incidence of wound dehiscence after the 7th postoperative day.

  5. c-Kit-mediated functional positioning of stem cells to their niches is essential for maintenance and regeneration of adult hematopoiesis.

    Directory of Open Access Journals (Sweden)

    Yuki Kimura

    Full Text Available The mechanism by which hematopoietic stem and progenitor cells (HSPCs through interaction with their niches maintain and reconstitute adult hematopoietic cells is unknown. To functionally and genetically track localization of HSPCs with their niches, we employed novel mutant loxPs, lox66 and lox71 and Cre-recombinase technology to conditionally delete c-Kit in adult mice, while simultaneously enabling GFP expression in the c-Kit-deficient cells. Conditional deletion of c-Kit resulted in hematopoietic failure and splenic atrophy both at steady state and after marrow ablation leading to the demise of the treated adult mice. Within the marrow, the c-Kit-expressing GFP(+ cells were positioned to Kit ligand (KL-expressing niche cells. This c-Kit-mediated cellular adhesion was essential for long-term maintenance and expansion of HSPCs. These results lay the foundation for delivering KL within specific niches to maintain and restore hematopoiesis.

  6. The types of hepatic myofibroblasts contributing to liver fibrosis of different etiologies.

    Directory of Open Access Journals (Sweden)

    JunXu

    2014-07-01

    Full Text Available Liver fibrosis results from dysregulation of normal wound healing, inflammation, activation of myofibroblasts and deposition of extracellular matrix (ECM. Chronic liver injury causes death of hepatocytes and formation of apoptotic bodies, which in turn, release factors that recruit inflammatory cells (neutrophils, monocytes, macrophages, and lymphocytes to the injured liver. Hepatic macrophages (Kupffer cells produce TGF1 and other inflammatory cytokines that activate Collagen Type I producing myofibroblasts, which are not present in the normal liver. Secretion of TGF1 and activation of myofibroblasts play a critical role in the pathogenesis of liver fibrosis of different etiologies. Although the composition of fibrogenic myofibroblasts varies dependent on etiology of liver injury, liver resident Hepatic Stellate Cells (HSCs and Portal Fibroblasts (PFs are the major source of myofibroblasts in fibrotic liver in both experimental models of liver fibrosis and in patients with liver disease. Several studies have demonstrated that hepatic fibrosis can reverse upon cessation of liver injury. Regression of liver fibrosis is accompanied by the disappearance of fibrogenic myofibroblasts followed by resorption of the fibrous scar. Myofibroblasts either apoptose or inactivate into a quiescent-like state (e.g. stop collagen production and partially restore expression of lypogenic genes. Resolution of liver fibrosis is associated with recruitment of macrophages that secrete matrix-degrading enzymes (matrix metalloproteinase, collagenases and are responsible for fibrosis resolution. However, prolonged/repeated liver injury may cause irreversible crosslinking of ECM and formation of uncleavable collagen fibers. Advanced fibrosis progresses to cirrhosis and hepatocellular carcinoma (HCC. The current review will summarize the role and contribution of different cell types to populations of fibrogenic myofibroblasts in fibrotic liver.

  7. Vascular dysfunction by myofibroblast activation in patients with idiopathic pulmonary fibrosis and prognostic significance

    OpenAIRE

    Parra, E.R.; Falzoni, R.; V.L. Capelozzi

    2012-01-01

    In this study, we demonstrated the importance of telomerase protein expression and determined the relationships among telomerase, endothelin-1 (ET-1) and myofibroblasts during early and late remodeling of parenchymal and vascular areas in usual interstitial pneumonia (UIP) using 27 surgical lung biopsies from patients with idiopathic pulmonary fibrosis (IPF). Telomerase+, myofibroblasts α-SMA+, smooth muscle cells caldesmon+, endothelium ET-1+ cellularity, and fibrosis severity were eval...

  8. Tenascin C upregulates IL-6 expression in Human Cardiac Myofibroblasts via Toll-Like Receptor 4

    OpenAIRE

    Midwood, KS; Maqbool, A; Spary, EJ; Manfield, IW; Ruhmann, M; Zuliani-Alvarez, L; Gamboa-Esteves, FO; Porter, KE; Drinkhill, MJ; Turner, NA

    2016-01-01

    AIM: To investigate the effect of Tenascin-C (TNC) on the expression of pro-inflammatory cytokines and matrix metalloproteinases in human cardiac myofibroblasts. METHODS: Cardiac myofibroblasts (CMF) were isolated and cultured from patients undergoing coronary artery bypass grafting. Cultured cells were treated with either TNC (0.1 µM, 24 h) or a recombinant protein corresponding to different domains of the TNC protein; fibrinogen-like globe (FBG) and fibronectin type III-like repeats (TN...

  9. Anaplasic lymphoma kinase positive inflammatory myofibroblastic tumour with renal pelvic calculus: a case report

    OpenAIRE

    Elfatemi, Hinde; Laila, Chbani; Znati, Kaoutar; Tazi, Mohamed Fadl; Ahallal, Youness; Tazi, Elmehdi; Farih, Moulay Hassan; Amarti, Afaf

    2009-01-01

    Inflammatory myofibroblastic tumour is a distinctive mesenchymal neoplasm, composed of a variable admixture of myofibroblastic spindle-shaped and inflammatory cells which were originally described in the lung, as a nonneoplastic lesion and designated as an inflammatory pseudotumour. The lack of certainty of the IMTs pathogenesis is reflected in the large number of terms which have been attributed to this lesion. Recent genetic and molecular studies of IMTs have showed chromosomal abnormalitie...

  10. Correlation between systolic function and presence of myofibroblasts in doxorubicin-induced cardiomyopathy

    OpenAIRE

    Fábio Nelson Gava; Sheila Nogueira Saraiva da Silva; Fernando Azadinho Rosa; Edna Mireya Gómez Ortiz; Bruno Cristian Rodrigues; Márcio de Barros Bandarra; Rosemeri de Oliveira Vasconcelos; Aparecido Antonio Camacho

    2016-01-01

    ABSTRACT: Cardiotoxicity induced by doroxubicin generates systolic disfunction and myocardial remodeling with presence of myofibroblasts. These cells are thought to be attracted to the injured heart to avoid the development of congestive heart failure. The objective of this study was to evaluate the systolic dysfunction generated by doxorubicin through Doppler echocardiography, and its correlation with the presence of myofibroblasts in the myocardium. Twenty-five New Zealand White rabbits wer...

  11. The dermal papilla: an instructive niche for epithelial stem and progenitor cells in development and regeneration of the hair follicle.

    Science.gov (United States)

    Morgan, Bruce A

    2014-07-01

    The dermal papilla (DP) of the hair follicle is both a chemical and physical niche for epithelial progenitor cells that regenerate the cycling portion of the hair follicle and generate the hair shaft. Here, we review experiments that revealed the importance of the DP in regulating the characteristics of the hair shaft and frequency of hair follicle regeneration. More recent work showed that the size of this niche is dynamic and actively regulated and reduction in DP cell number per follicle is sufficient to cause hair thinning and loss. The formation of the DP during follicle neogenesis provides a context to contemplate the mechanisms that maintain DP size and the potential to exploit these processes for hair preservation or restoration. PMID:24985131

  12. Lichen planopilaris is characterized by immune privilege collapse of the hair follicle's epithelial stem cell niche.

    Science.gov (United States)

    Harries, Matthew J; Meyer, Katja; Chaudhry, Iskander; E Kloepper, Jennifer; Poblet, Enrique; Griffiths, Christopher Em; Paus, Ralf

    2013-10-01

    Lichen planopilaris (LPP) is a chronic inflammatory disease of unknown pathogenesis that leads to permanent hair loss. Whilst destruction of epithelial hair follicle stem cells (eHFSCs) that reside in an immunologically protected niche of the HF epithelium, the bulge, is a likely key event in LPP pathogenesis, this remains to be demonstrated. We have tested the hypotheses that bulge immune privilege (IP) collapse and inflammation-induced eHFSC death are key components in the pathogenesis of LPP. Biopsies of lesional and non-lesional scalp skin from adult LPP patients (n = 42) were analysed by quantitative (immuno)histomorphometry, real-time quantitative polymerase chain reaction (qRT-PCR), laser capture microdissection and microarray analysis, or skin organ culture. At both the protein and transcriptional level, lesional LPP HFs showed evidence for bulge IP collapse (ie increased expression of MHC class I and II, β2microglobulin; reduced TGFβ2 and CD200 expression). This was accompanied by a Th1-biased cytotoxic T cell response (ie increased CD8(+) GranzymeB(+) T cells and CD123(+) plasmacytoid dendritic cells, with increased CXCR3 expression) and increased expression of interferon-inducible chemokines (CXCL9/10/11). Interestingly, lesional LPP eHFSCs showed both increased proliferation and apoptosis in situ. Microarray analysis revealed a loss of eHFSC signatures and increased expression of T cell activation/binding markers in active LPP, while bulge PPARγ transcription was unaltered compared to non-lesional LPP HFs. In organ culture of non-lesional LPP skin, interferon-γ (IFNγ) induced bulge IP collapse. LPP is an excellent model disease for studying and preventing immune destruction of human epithelial stem cells in situ. These novel findings raise the possibility that LPP represents an autoimmune disease in whose pathogenesis IFNγ-induced bulge IP collapse plays an important role. Therapeutically, bulge IP protection/restoration may help to better manage

  13. 干细胞niche与肿瘤的发生发展%Stem cell niche in genesis and development of cancer

    Institute of Scientific and Technical Information of China (English)

    赵璇; 冉宇靓

    2009-01-01

    干细胞niche是干细胞生存的微环境,在维持干细胞自我更新和分化过程中起着极为关键的作用.肿瘤干细胞在功能异常的niche中生存,控制着肿瘤的发生,适当的niche环境可以促进肿瘤的生长转移.改变特异的niche可以抑制、影响肿瘤的多种恶性表型.%Stem cell niche is the microenvironment in which stem cells reside,and it is essential for stem cells self-renewal and differentiation. Tumor stem cells which live in abnormal niche control tumor genesis,and appropriate niche can promote tumor growth and metastasis. Altering unique niche can suppress and affect malignant phenotypes of tumor.

  14. Gastrospheres of human gastric mucosa cells: an in vitro model of stromal and epithelial stem cell niche reconstruction.

    Science.gov (United States)

    Santos, Carlos A N; Andrade, Leonardo R; Costa, Márcia H M; Souza, Heitor S P; Granjeiro, José M; Takiya, Christina M; Borojevic, Radovan; Nasciutti, Luiz E

    2016-08-01

    The molecular characterization of mechanisms involved in the gastrointestinal tract disorders needs an in vitro 3D culture model able to mimic the in vivo gastric microenvironment. Herein, we propose a 3D coculture system where gastric epithelial and stromal cells are grown together building spherical and solid structures using the NASA bioreactor - cell culture system (RCCS), a bioreactor. Epithelial and stromal cells from human antral gastric mucosa were isolated from endoscopic gastric biopsies. Thereafter, these cells were mechanically and enzymatically dispersed by treatment with dispase and collagenase, respectively. Using specific culture procedures, these cells formed 3D structures by using a RCCS, named "gastrospheres". Briefly, gastrospheres were obtained by initial seeding of 2.5x10⁴ cells/well in 96 well culture plates. At 24 h after their formation, they were transferred into RCCS, and maintained for 7, 14, 21, and 28 days. The gastrospheres were morphologically characterized by immunocytochemisty to evaluate extracellular matrix (ECM), and by electron microscopy. These analysis of gastrospheres revealed that the epithelial cells were cytokeratin (CK) and lectin reactive and were arranged in the outer layer; stromal cells presented long cytoplasmic processes and were localized inside the gastrosphere. They were vimentin (VIM) and α-smooth muscle actin (α-SMA) positive and expressed ECM components such as laminin (LN), fibronectin (FN), and type IV collagen (CIV). Electron microscopy revealed groups of cohesive gastric cells surrounded by complex stromal structures, with multiple microvilli, and tight cellular junctions interspersed with extracellular matrix fibrils and fibers. The presence of some nestin-positive cells was observed in the inner region of the gastrospheres, suggesting an intermediary localization between epithelial and stromal cells. Altogether, our data suggest that in vitro gastrospheres recapitulate the in vivo gastric niche

  15. Cancer Stem Cells Converted from Pluripotent Stem Cells and the Cancerous Niche

    OpenAIRE

    Kasai, T; Chen, L.; Mizutani, AZ; Kudoh, T.; Murakami, H; Fu, L.; Seno, M

    2014-01-01

    Nowadays, the cancer stem cells are considered to be significantly responsible for growth, metastasis, invasion and recurrence of all cancer. Cancer stem cells are typically characterized by continuous proliferation and self-renewal as well as by differentiation potential, while stem cells are considered to differentiate into tissue- specific phenotype of mature cells under the influence of micro-environment. Cancer stem cells should be traced to the stem cells under the influence of a micro-...

  16. The Hemopoietic Stem Cell Niche Versus the Microenvironment of the Multiple Myeloma-Tumor Initiating Cell

    OpenAIRE

    Zipori, Dov

    2010-01-01

    Multiple myeloma cells are reminiscent of hemopoietic stem cells in their strict dependence upon the bone marrow microenvironment. However, from all other points of view, multiple myeloma cells differ markedly from stem cells. The cells possess a mature phenotype and secrete antibodies, and have thus made the whole journey to maturity, while maintaining a tumor phenotype. Not much credence was given to the possibility that the bulk of plasma-like multiple myeloma tumor cells is generated from...

  17. Expression of histone deacetylase 3 instructs alveolar type I cell differentiation by regulating a Wnt signaling niche in the lung.

    Science.gov (United States)

    Wang, Xiaoru; Wang, Yi; Snitow, Melinda E; Stewart, Kathleen M; Li, Shanru; Lu, MinMin; Morrisey, Edward E

    2016-06-15

    The commitment and differentiation of the alveolar type I (AT1) cell lineage is a critical step for the formation of distal lung saccules, which are the primitive alveolar units required for postnatal respiration. How AT1 cells arise from the distal lung epithelial progenitor cells prior to birth and whether this process depends on a developmental niche instructed by mesenchymal cells is poorly understood. We show that mice lacking histone deacetylase 3 specifically in the developing lung mesenchyme display lung hypoplasia including decreased mesenchymal proliferation and a severe impairment of AT1 cell differentiation. This is correlated with a decrease in Wnt/β-catenin signaling in the lung epithelium. We demonstrate that inhibition of Wnt signaling causes defective AT1 cell lineage differentiation ex vivo. Importantly, systemic activation of Wnt signaling at specific stages of lung development can partially rescue the AT1 cell differentiation defect in vivo. These studies show that histone deacetylase 3 expression generates an important developmental niche in the lung mesenchyme through regulation of Wnt signaling, which is required for proper AT1 cell differentiation and lung sacculation. PMID:27141870

  18. Tumor-like stem cells derived from human keloid are governed by the inflammatory niche driven by IL-17/IL-6 axis.

    Directory of Open Access Journals (Sweden)

    Qunzhou Zhang

    Full Text Available BACKGROUND: Alterations in the stem cell niche are likely to contribute to tumorigenesis; however, the concept of niche promoted benign tumor growth remains to be explored. Here we use keloid, an exuberant fibroproliferative dermal growth unique to human skin, as a model to characterize benign tumor-like stem cells and delineate the role of their "pathological" niche in the development of the benign tumor. METHODS AND FINDINGS: Subclonal assay, flow cytometric and multipotent differentiation analyses demonstrate that keloid contains a new population of stem cells, named keloid derived precursor cells (KPCs, which exhibit clonogenicity, self-renewal, distinct embryonic and mesenchymal stem cell surface markers, and multipotent differentiation. KPCs display elevated telomerase activity and an inherently upregulated proliferation capability as compared to their peripheral normal skin counterparts. A robust elevation of IL-6 and IL-17 expression in keloid is confirmed by cytokine array, western blot and ELISA analyses. The altered biological functions are tightly regulated by the inflammatory niche mediated by an autocrine/paracrine cytokine IL-17/IL-6 axis. Utilizing KPCs transplanted subcutaneously in immunocompromised mice we generate for the first time a human keloid-like tumor model that is driven by the in vivo inflammatory niche and allows testing of the anti-tumor therapeutic effect of antibodies targeting distinct niche components, specifically IL-6 and IL-17. CONCLUSIONS/SIGNIFICANCE: These findings support our hypothesis that the altered niche in keloids, predominantly inflammatory, contributes to the acquirement of a benign tumor-like stem cell phenotype of KPCs characterized by the uncontrolled self-renewal and increased proliferation, supporting the rationale for in vivo modification of the "pathological" stem cell niche as a novel therapy for keloid and other mesenchymal benign tumors.

  19. Stromal-cell and cancer-cell exosomes leading the metastatic exodus for the promised niche

    OpenAIRE

    Hoffman, Robert M.

    2013-01-01

    Exosomes are thought to play an important role in metastasis. Luga and colleagues have described the production of exosomes by stromal cells such as cancer-associated fibroblasts that are taken up by breast cancer cells and are then loaded with Wnt 11, which is associated with stimulation of the invasiveness and metastasis of the breast cancer cells. Previous studies have shown that exosomes produced by breast cancer cells are taken up by stromal fibroblasts and other stromal cells, suggestin...

  20. Molecular Targets of Chromatin Repressive Mark H3K9me3 in Primate Progenitor Cells within Adult Neurogenic Niches

    Directory of Open Access Journals (Sweden)

    Michael R Foret

    2014-07-01

    Full Text Available Histone 3 Lysine 9 (H3K9 methylation is known to be associated with pericentric heterochromatin and important in genomic stability. In this study, we show that trimethylation at H3K9 (H3K9me3 is enriched in an adult neural stem cell niche- the subventricular zone (SVZ on the walls of the lateral ventricle in both rodent and non-human primate baboon brain. Previous studies have shown that there is significant correlation between baboon and human regarding genomic similarity and brain structure, suggesting that findings in baboon are relevant to human. To understand the function of H3K9me3 in this adult neurogenic niche, we performed genome-wide analyses using ChIP-Seq (chromatin immunoprecipitation and deep-sequencing and RNA-Seq for in vivo SVZ cells purified from baboon brain. Through integrated analyses of ChIP-Seq and RNA-Seq, we found that H3K9me3-enriched genes associated with cellular maintenance, post-transcriptional and translational modifications, signaling pathways, and DNA replication are expressed, while genes involved in axon/neuron, hepatic stellate cell, or immune-response activation are not expressed. As neurogenesis progresses in the adult SVZ, cell fate restriction is essential to direct proper lineage commitment. Our findings highlight that H3K9me3 repression in undifferentiated SVZ cells is engaged in the maintenance of cell type integrity, implicating a role for H3K9me3 as an epigenetic mechanism to control cell fate transition within this adult germinal niche.

  1. Dabigatran, a direct thrombin inhibitor, blocks differentiation of normal fibroblasts to a myofibroblast phenotype and demonstrates anti-fibrotic effects on scleroderma lung fibroblasts

    OpenAIRE

    Bogatkevich, Galina S.; Ludwicka-Bradley, Anna; Silver, Richard M.

    2009-01-01

    Myofibroblasts are the principal mesenchymal cells responsible for tissue remodeling, collagen deposition, and the restrictive nature of lung parenchyma associated with pulmonary fibrosis. We previously reported that thrombin activates protease-activated receptor (PAR)-1 thereby inducing normal lung fibroblasts to differentiate to a myofibroblast phenotype resembling scleroderma lung myofibroblasts. Here we demonstrate that the thrombin inhibitor dabigatran inhibits in a dose-dependant manner...

  2. Simvastatin induces apoptosis by a Rho-dependent mechanism in cultured cardiac fibroblasts and myofibroblasts

    International Nuclear Information System (INIS)

    Several clinical trials have shown the beneficial effects of statins in the prevention of coronary heart disease. Additionally, statins promote apoptosis in vascular smooth muscle cells, in renal tubular epithelial cells and also in a variety of cell lines; yet, the effects of statins on cardiac fibroblast and myofibroblast, primarily responsible for cardiac tissue healing are almost unknown. Here, we investigated the effects of simvastatin on cardiac fibroblast and myofibroblast viability and studied the molecular cell death mechanism triggered by simvastatin in both cell types. Methods: Rat neonatal cardiac fibroblasts and myofibroblasts were treated with simvastatin (0.1-10 μM) up to 72 h. Cell viability and apoptosis were evaluated by trypan blue exclusion method and by flow cytometry, respectively. Caspase-3 activation and Rho protein levels and activity were also determined by Western blot and pull-down assay, respectively. Results: Simvastatin induces caspase-dependent apoptosis of cardiac fibroblasts and myofibroblasts in a concentration- and time-dependent manner, with greater effects on fibroblasts than myofibroblasts. These effects were prevented by mevalonate, farnesylpyrophosphate and geranylgeranylpyrophosphate, but not squalene. These last results suggest that apoptosis was dependent on small GTPases of the Rho family rather than Ras. Conclusion: Simvastatin triggered apoptosis of cardiac fibroblasts and myofibroblasts by a mechanism independent of cholesterol synthesis, but dependent of isoprenilation of Rho protein. Additionally, cardiac fibroblasts were more susceptible to simvastatin-induced apoptosis than cardiac myofibroblasts. Thus simvastatin could avoid adverse cardiac remodeling leading to a less fibrotic repair of the damaged tissues. - Research Highlights: → Simvastatin decreases CF and CMF viability independent of cholesterol synthesis. → Simvastatin induces CF and CMF apoptosis in a caspase-dependent manner being CMF more resistant

  3. Molecular biological characteristics of the recruitment of hematopoietic stem cells from bone marrow niche in chronic myeloid leukemia

    OpenAIRE

    Zhu, Biao; Zhang, Jianbo; Chen, Jiao; Li, Chenglong; Wang, Xiaodong

    2015-01-01

    Chronic myeloid leukemia (CML) can be contextualized as a disease of unregulated self-renewal of stem cells which exist in a quiescent state and are instructed to differentiate and mobilize to circulation under pathologic circumstances leading to tumor invasion and metastasis. Here we found that matrix metalloproteinase-9 (MMP-9), induced by TGF-β1, upregulated s-KitL and s-ICAM-1, permitting the transfer of c-kit+ hematopoietic stem cells (HSCs) from the quiescent to proliferative niche in C...

  4. Transition from non-renewable to renewable energy sources: fuel cells in Antarctica as an economically attractive niche

    International Nuclear Information System (INIS)

    There is a growing amount of evidence that indicates that fuel cells might be commercially attractive in several market niches in Latin America; however, political approval of demonstration projects has been elusive. In this paper, the results of an economic study carried out on the assumption of introducing an environmentally friendly fuel, such as methanol, for feeding fuel cell systems for electricity generation and heat production in the six bases that Argentina has in Antarctica are reported. It is seen that, in this particular case, there is a net cost benefit, even if the assets resulting from diminishing pollution in Antarctica are not taken into account. (Author)

  5. Niche-induced cell death and epithelial phagocytosis regulate hair follicle stem cell pool.

    Science.gov (United States)

    Mesa, Kailin R; Rompolas, Panteleimon; Zito, Giovanni; Myung, Peggy; Sun, Thomas Y; Brown, Samara; Gonzalez, David G; Blagoev, Krastan B; Haberman, Ann M; Greco, Valentina

    2015-06-01

    Tissue homeostasis is achieved through a balance of cell production (growth) and elimination (regression). In contrast to tissue growth, the cells and molecular signals required for tissue regression remain unknown. To investigate physiological tissue regression, we use the mouse hair follicle, which cycles stereotypically between phases of growth and regression while maintaining a pool of stem cells to perpetuate tissue regeneration. Here we show by intravital microscopy in live mice that the regression phase eliminates the majority of the epithelial cells by two distinct mechanisms: terminal differentiation of suprabasal cells and a spatial gradient of apoptosis of basal cells. Furthermore, we demonstrate that basal epithelial cells collectively act as phagocytes to clear dying epithelial neighbours. Through cellular and genetic ablation we show that epithelial cell death is extrinsically induced through transforming growth factor (TGF)-β activation and mesenchymal crosstalk. Strikingly, our data show that regression acts to reduce the stem cell pool, as inhibition of regression results in excess basal epithelial cells with regenerative abilities. This study identifies the cellular behaviours and molecular mechanisms of regression that counterbalance growth to maintain tissue homeostasis. PMID:25849774

  6. Niche induced cell death and epithelial phagocytosis regulate hair follicle stem cell pool

    Science.gov (United States)

    Mesa, Kailin R.; Rompolas, Panteleimon; Zito, Giovanni; Myung, Peggy; Sun, Thomas Yang; Brown, Samara; Gonzalez, David; Blagoev, Krastan B.; Haberman, Ann M.; Greco, Valentina

    2015-01-01

    Summary Tissue homeostasis is achieved through a balance of cell production (growth) and elimination (regression)1,2. Contrary to tissue growth, the cells and molecular signals required for tissue regression remain unknown. To investigate physiological tissue regression, we use the mouse hair follicle, which cycles stereotypically between phases of growth and regression while maintaining a pool of stem cells to perpetuate tissue regeneration3. Here we show by intravital microscopy in live mice4–6 that the regression phase eliminates the majority of the epithelial cells by two distinct mechanisms: terminal differentiation of suprabasal cells and a spatial gradient of apoptosis of basal cells. Furthermore, we demonstrate that basal epithelial cells collectively act as phagocytes to clear dying epithelial neighbors. Through cellular and genetic ablation we show that epithelial cell death is extrinsically induced through TGFβ activation and mesenchymal crosstalk. Strikingly, our data show that regression acts to reduce the stem cell pool as inhibition of regression results in excess basal epithelial cells with regenerative abilities. This study identifies the cellular behaviors and molecular mechanisms of regression that counterbalance growth to maintain tissue homeostasis. PMID:25849774

  7. Mesenchymal Stem/Stromal Cells Derived From a Reproductive Tissue Niche Under Oxidative Stress Have High Aldehyde Dehydrogenase Activity.

    Science.gov (United States)

    Kusuma, Gina D; Abumaree, Mohamed H; Pertile, Mark D; Perkins, Anthony V; Brennecke, Shaun P; Kalionis, Bill

    2016-06-01

    The use of mesenchymal stem/stromal cells (MSC) in regenerative medicine often requires MSC to function in environments of high oxidative stress. Human pregnancy is a condition where the mother's tissues, and in particular her circulatory system, are exposed to increased levels of oxidative stress. MSC in the maternal decidua basalis (DMSC) are in a vascular niche, and thus would be exposed to oxidative stress products in the maternal circulation. Aldehyde dehydrogenases (ALDH) are a large family of enzymes which detoxify aldehydes and thereby protect stem cells against oxidative damage. A subpopulation of MSC express high levels of ALDH (ALDH(br)) and these are more potent in repairing and regenerating tissues. DMSC was compared with chorionic villous MSC (CMSC) derived from the human placenta. CMSC reside in vascular niche and are exposed to the fetal circulation, which is in lower oxidative state. We screened an ALDH isozyme cDNA array and determined that relative to CMSC, DMSC expressed high levels of ALDH1 family members, predominantly ALDH1A1. Immunocytochemistry gave qualitative confirmation at the protein level. Immunofluorescence detected ALDH1 immunoreactivity in the DMSC and CMSC vascular niche. The percentage of ALDH(br) cells was calculated by Aldefluor assay and DMSC showed a significantly higher percentage of ALDH(br) cells than CMSC. Finally, flow sorted ALDH(br) cells were functionally potent in colony forming unit assays. DMSC, which are derived from pregnancy tissues that are naturally exposed to high levels of oxidative stress, may be better candidates for regenerative therapies where MSC must function in high oxidative stress environments. PMID:26880140

  8. The stem cell niche: tissue physiology at a single cell level

    OpenAIRE

    Hoggatt, Jonathan; Scadden, David T.

    2012-01-01

    Stem cells are the critical unit affecting tissue maintenance, regeneration, and repair, with particular relevance to the tissues with high cell turnover. Stem cell regulation accommodates the conflicting needs of prompt responsiveness to injury and long-term preservation through quiescence. They are, in essence, the fundamental unit by which a tissue handles changing physiologic needs throughout the lifetime of the organism. As such, they are the focal point of dynamic tissue function, and t...

  9. CT features of inflammatory myofibroblastic tumor in children

    International Nuclear Information System (INIS)

    Objective: To investigate the CT features of inflammatory myofibroblastic tumor in children. Methods: Eighteen patients with inflammatory myofibroblastic tumor proven by surgery and pathology were examined with plain and contrast medium enhancement CT scan. Results: Of 18 cases, 16 had isolated lesions located at lung (n=4), mesentery (n=3), kidney (n=2) and trachea (n=1), left main bronchus (n=1), right thoracic cavity (n=1), peritoneum cavity (n=1), pancreas (n=1), left thigh (n=1), prostate (n=1), superclavicle soft t tissue (n=1), bladder (n=1). The other 2 cases were with multiple lesions on omentum and mesentery, and in intraperitoneal and side of split of right hepatic lobe, respectively. The CT findings of 18 cases included 16 solid mass with calcifications in 3 of them, and 2 solid-cystic mass. After contrast enhancement, moderate or marked homogeneous or heterogeneous enhancement were shown in all the solid parts of tumor on dynamic CT. Mass can compress surround great vessel and tube-like structure. On pathological examination, the tumor was mainly composed of spindle- shaped fibrous cells and inflammatory cells, and the immunohistochemically staining for SMA was observed positively. Conclusion: CT can provide specific information for diagnosis of inflammatory myofibroblastic tumor, yet definite diagnosis relies on pathology. (authors)

  10. Bovine mammary stem cells: Transcriptome profiling and the stem cell niche

    Science.gov (United States)

    Identification and transcriptome analysis of mammary stem cells (MaSC) are important steps toward understanding the molecular basis of mammary epithelial growth, homeostasis and tissue repair. Our objective was to evaluate the molecular profiles of four categories of cells within the bovine mammary ...

  11. Artificial Niches for Stromal Stem Cells as a Potential Instrument for the Design of the Surface of Biomimetic Osteogenic Materials

    Science.gov (United States)

    Khlusov, I. A.; Khlusova, M. Yu.; Pichugin, V. F.; Sharkeev, Yu. P.; Legostaeva, E. V.

    2014-02-01

    A relationship between the topography of rough calcium phosphate surfaces having osteogenic niche-reliefs and the electrostatic potential of these surfaces as a possible instrument to control stromal stem cells has been investigated. The in vitro culture of human lung prenatal stromal cells on nanostructured/ultrafine-grained VT1.0 titanium alloy plates with bilateral rough calcium phosphate (CaP) microarc coating was used. It was established that the amplitude of the electret CaP surface potential linearly increased with increasing area of valleys (sockets), and the negative charge is formed on the socket surface. The area of alkaline phosphatase staining (the marker of osteoblast maturation and differentiation) of adherent CD34- CD44+ cells increases linearly with increasing area of artificial microterritory (socket) of the CaP surface occupied with each cell. The negative electret potential in valleys (sockets) of microarc CaP coatings can be the physical mechanism mediating the influence of the surface topography on osteogenic maturation and differentiation of cells in vitro. This mechanism can be called "niche-potential" and can be used as an instrument for biomimetic modification of smooth CaP surfaces to strengthen their integration with the bone tissue.

  12. Inflammatory myofibroblastic tumour of maxilla

    Directory of Open Access Journals (Sweden)

    Deshingkar S

    2007-01-01

    Full Text Available Inflammatory myofibroblastic tumour (IMT is a biologically controversial entity that was originally described as non-neoplastic lesion in the lungs and designated initially as inflammatory pseudotumour. The lesion has recently been recognized to occur at various sites but rarely affects head and neck region. Controversies still exist regarding its reactive versus neoplastic nature. The lesion has a potential for recurrence, persistent local growth, progression to frank sarcoma and metastasis. Hence IMT can best be regarded as a low-grade sarcoma. A case of a 30-year-old female with swelling in the right maxilla and associated ophthalmic manifestations is discussed here. Contribution of immunohistochemistry for diagnosis of IMT is emphasized. Additional cytogenetic studies of this highly enigmatic and minimally studied tumour are warranted.

  13. Progenitor cell niches in the human pancreatic duct system and associated pancreatic duct glands: an anatomical and immunophenotyping study.

    Science.gov (United States)

    Carpino, Guido; Renzi, Anastasia; Cardinale, Vincenzo; Franchitto, Antonio; Onori, Paolo; Overi, Diletta; Rossi, Massimo; Berloco, Pasquale Bartolomeo; Alvaro, Domenico; Reid, Lola M; Gaudio, Eugenio

    2016-03-01

    Pancreatic duct glands (PDGs) are tubule-alveolar glands associated with the pancreatic duct system and can be considered the anatomical counterpart of peribiliary glands (PBGs) found within the biliary tree. Recently, we demonstrated that endodermal precursor niches exist fetally and postnatally and are composed functionally of stem cells and progenitors within PBGs and of committed progenitors within PDGs. Here we have characterized more extensively the anatomy of human PDGs as novel niches containing cells with multiple phenotypes of committed progenitors. Human pancreata (n = 15) were obtained from cadaveric adult donors. Specimens were processed for histology, immunohistochemistry and immunofluorescence. PDGs were found in the walls of larger pancreatic ducts (diameters > 300 μm) and constituted nearly 4% of the duct wall area. All of the cells identified were negative for nuclear expression of Oct4, a pluripotency gene, and so are presumably committed progenitors and not stem cells. In the main pancreatic duct and in large interlobular ducts, Sox9(+) cells represented 5-30% of the cells within PDGs and were located primarily at the bottom of PDGs, whereas rare and scattered Sox9(+) cells were present within the surface epithelium. The expression of PCNA, a marker of cell proliferation, paralleled the distribution of Sox9 expression. Sox9(+) PDG cells proved to be Pdx1(+) /Ngn3(+/-) /Oct4A(-) . Nearly 10% of PDG cells were positive for insulin or glucagon. Intercalated ducts contained Sox9(+) /Pdx1(+) /Ngn3(+) cells, a phenotype that is presumptive of committed endocrine progenitors. Some intercalated ducts appeared in continuity with clusters of insulin-positive cells organized in small pancreatic islet-like structures. In summary, PDGs represent niches of a population of Sox9(+) cells exhibiting a pattern of phenotypic traits implicating a radial axis of maturation from the bottoms of the PDGs to the surface of pancreatic ducts. Our results complete the

  14. Regulation of human umbilical cord blood-derived multi-potent stem cells by autogenic osteoclast-based niche-like structure

    International Nuclear Information System (INIS)

    Stem cell niches provide the micro-environment for the development of stem cells. Under our culturing regimen, a kind of osteoclast-centralized structure supports the proliferation of MSCs, derived from human cord blood, once they reside on osteoclasts. MSCs in this structure expressed Oct4 which is a marker of embryonic stem cells. Floating daughter cells of MSCs colony showed abilities to differentiate into osteocyte, adipocyte, and neuronal progenitor cells. Compared with the easy senescence of MSCs without this niche-like structure in vitro, these results suggested that osteoclasts might play an important role the development and maintenance of Umbilical cord blood (UCB)-derived MSCs and might provide a means to expand UCB-MSCs in vitro, more easily, through a stem cell niche-like structure

  15. Tomb niche

    OpenAIRE

    O'Donovan, Danielle

    2004-01-01

    Capital frieze running along jamb of tomb niche. Moulding from the top down comprises: chamfer, frontal fillet, angle-fillet, fillet, angle-fillet, flat surface, angle-fillet, fillet, flat surface. The lower secion can be read as a stepped rebate.

  16. c-Myb in incisor stem cell niches and in differentiation of odontogenic cells

    Czech Academy of Sciences Publication Activity Database

    Matalová, Eva; Lungová, Vlasta; Buchtová, Marcela; Švandová, Eva; Šmarda, J.

    Warwick: BSCB, 2012. 93-94. [British Society for Developmental Biology, Bristish Society for Cell Biology and Japanese Society of Developmental Biologists Joint Spring Meeting. 15.04.2012-18.04.2012, Warwick] R&D Projects: GA ČR GCP302/12/J059; GA ČR GAP304/11/1418 Institutional support: RVO:67985904 Keywords : c-Myb Subject RIV: EA - Cell Biology

  17. A Synthetic Polymer Scaffold Reveals the Self-Maintenance Strategies of Rat Glioma Stem Cells by Organization of the Advantageous Niche.

    Science.gov (United States)

    Tabu, Kouichi; Muramatsu, Nozomi; Mangani, Christian; Wu, Mei; Zhang, Rong; Kimura, Taichi; Terashima, Kazuo; Bizen, Norihisa; Kimura, Ryosuke; Wang, Wenqian; Murota, Yoshitaka; Kokubu, Yasuhiro; Nobuhisa, Ikuo; Kagawa, Tetsushi; Kitabayashi, Issay; Bradley, Mark; Taga, Tetsuya

    2016-05-01

    Cancer stem cells (CSCs) are believed to be maintained within a microenvironmental niche. Here we used polymer microarrays for the rapid and efficient identification of glioma CSC (GSC) niche mimicries and identified a urethane-based synthetic polymer, upon which two groups of niche components, namely extracellular matrices (ECMs) and iron are revealed. In cultures, side population (SP) cells, defined as GSCs in the rat C6 glioma cell line, are more efficiently sustained in the presence of their differentiated progenies expressing higher levels of ECMs and transferrin, while in xenografts, ECMs are supplied by the vascular endothelial cells (VECs), including SP cell-derived ones with distinctively greater ability to retain xenobiotics than host VECs. Iron is stored in tumor infiltrating host macrophages (Mφs), whose protumoral activity is potently enhanced by SP cell-secreted soluble factor(s). Finally, coexpression of ECM-, iron-, and Mφ-related genes is found to be predictive of glioma patients' outcome. Our polymer-based approach reveals the intrinsic capacities of GSCs, to adapt the environment to organize a self-advantageous microenvironment niche, for their maintenance and expansion, which redefines the current concept of anti-CSC niche therapy and has the potential to accelerate cancer therapy development. Stem Cells 2016;34:1151-1162. PMID:26822103

  18. Development of the Fetal Bone Marrow Niche and Regulation of HSC Quiescence and Homing Ability by Emerging Osteolineage Cells

    Directory of Open Access Journals (Sweden)

    Süleyman Coşkun

    2014-10-01

    Full Text Available Hematopoietic stem cells (HSCs reside within a specialized niche where interactions with vasculature, osteoblasts, and stromal components regulate their self-renewal and differentiation. Little is known about bone marrow niche formation or the role of its cellular components in HSC development; therefore, we established the timing of murine fetal long bone vascularization and ossification relative to the onset of HSC activity. Adult-repopulating HSCs emerged at embryonic day 16.5 (E16.5, coincident with marrow vascularization, and were contained within the c-Kit+Sca-1+Lin− (KSL population. We used Osterix-null (Osx−/− mice that form vascularized marrow but lack osteolineage cells to dissect the role(s of these cellular components in HSC development. Osx−/− fetal bone marrow cells formed multilineage colonies in vitro but were hyperproliferative and failed to home to and/or engraft transplant recipients. Thus, in developing bone marrow, the vasculature can sustain multilineage progenitors, but interactions with osteolineage cells are needed to regulate long-term HSC proliferation and potential.

  19. Cancer exosomes trigger fibroblast to myofibroblast differentiation.

    Science.gov (United States)

    Webber, Jason; Steadman, Robert; Mason, Malcolm D; Tabi, Zsuzsanna; Clayton, Aled

    2010-12-01

    There is a growing interest in the cell-cell communication roles in cancer mediated by secreted vesicles termed exosomes. In this study, we examined whether exosomes produced by cancer cells could transmit information to normal stromal fibroblasts and trigger a cellular response. We found that some cancer-derived exosomes could trigger elevated α-smooth muscle actin expression and other changes consistent with the process of fibroblast differentiation into myofibroblasts. We show that TGF-β is expressed at the exosome surface in association with the transmembrane proteoglycan betaglycan. Although existing in a latent state, this complex was fully functional in eliciting SMAD-dependent signaling. Inhibiting either signaling or betaglycan expression attenuated differentiation. While the kinetics and overall magnitude of the response were similar to that achieved with soluble TGF-β, we identified important qualitative differences unique to the exosomal route of TGF-β delivery, as exemplified by a significant elevation in fibroblast FGF2 production. This hitherto unknown trigger for instigating cellular differentiation in a distinctive manner has major implications for mechanisms underlying cancer-recruited stroma, fibrotic diseases, and wound-healing responses. PMID:21098712

  20. Fibrocytes contribute to the myofibroblast population in wounded skin and originate from the bone marrow

    International Nuclear Information System (INIS)

    Myofibroblasts play a key role in wound closure but their origin is poorly understood. To investigate whether fibrocytes contribute to myofibroblast population, we examined the phenotype of fibrocytes and myofibroblasts present in the wounded skin of BALB/c mice. During wound healing, there was a marked increase in the number of cells expressing the myofibroblast marker α-smooth muscle actin in the granulation tissue. Between 4 and 7 days post-wounding, more than 50% of these cells also expressed the CD13 antigen. CD13+/collagen I+ fibrocytes could be isolated at an early stage of the healing process from digested fragments of wounded tissue by fluorescence-activated cell sorting. Like authentic fibrocytes, these cells were also CD45+/CD34+/CD14-. Between 4 and 7 days post-injury, 61.4% of the isolated fibrocytes were found to express α-smooth muscle actin gene and protein. We repeated similar experiments in female mice that had received a male whole bone marrow transplant after total body irradiation. By in situ hybridization, we identified the Y chromosome in the nuclei of the majority of fibrocytes isolated from the wounded tissue of these animals. Our data indicate that circulating fibrocytes contribute to the myofibroblast population in the wounded skin and that they originate from the bone marrow

  1. Inflammatory myofibroblastic tumor appendix with concomitant mucosal dysplasia, simulating pseudomyxoma on preoperative aspiration cytology

    Directory of Open Access Journals (Sweden)

    Kaushik Majumdar

    2012-01-01

    Full Text Available Inflammatory myofibroblastic tumor (IMT has been described as a pseudosarcomatous proliferation of spindled myofibroblasts admixed with lymphoplasmacytic cells. The various terminologies like inflammatory pseudotumor, plasma cell granuloma, and inflammatory myofibrohistiocytic proliferation, used to describe this entity, highlight the controversial etiopathogenesis of this relatively indolent neoplasm. IMT has now been described in different anatomic locations. However, cases occurring in the gastrointestinal tract are rare with very few cases described in the appendix. We present a case of inflammatory myofibroblastic tumor appendix with mucosal dysplasia in a 41-year-old male, presenting with abdominal pain and lump in the right iliac fossa. Aspiration cytology yielded few atypical epithelial cells and spindle cells in a mucinous background, suggesting the possibility of pseudomyxoma peritonei. Awareness of IMT appendix with rare presence of mucosal dysplasia may help in preventing overzealous resection, especially in situations that on preoperative evaluation may suggest malignancy.

  2. Role of scleraxis in mechanical stretch-mediated regulation of cardiac myofibroblast phenotype.

    Science.gov (United States)

    Roche, Patricia L; Nagalingam, Raghu S; Bagchi, Rushita A; Aroutiounova, Nina; Belisle, Breanna M J; Wigle, Jeffrey T; Czubryt, Michael P

    2016-08-01

    The phenotype conversion of fibroblasts to myofibroblasts plays a key role in the pathogenesis of cardiac fibrosis. Numerous triggers of this conversion process have been identified, including plating of cells on solid substrates, cytokines such as transforming growth factor-β, and mechanical stretch; however, the underlying mechanisms remain incompletely defined. Recent studies from our laboratory revealed that the transcription factor scleraxis is a key regulator of cardiac fibroblast phenotype and extracellular matrix expression. Here we report that mechanical stretch induces type I collagen expression and morphological changes indicative of cardiac myofibroblast conversion, as well as scleraxis expression via activation of the scleraxis promoter. Scleraxis causes phenotypic changes similar to stretch, and the effect of stretch is attenuated in scleraxis null cells. Scleraxis was also sufficient to upregulate expression of vinculin and F-actin, to induce stress fiber and focal adhesion formation, and to attenuate both cell migration and proliferation, further evidence of scleraxis-mediated regulation of fibroblast to myofibroblast conversion. Together, these data confirm that scleraxis is sufficient to promote the myofibroblast phenotype and is a required effector of stretch-mediated conversion. Scleraxis may thus represent a potential target for the development of novel antifibrotic therapies aimed at inhibiting myofibroblast formation. PMID:27357547

  3. A comparative pan-genome perspective of niche-adaptable cell-surface protein phenotypes in Lactobacillus rhamnosus.

    Directory of Open Access Journals (Sweden)

    Ravi Kant

    Full Text Available Lactobacillus rhamnosus is a ubiquitously adaptable Gram-positive bacterium and as a typical commensal can be recovered from various microbe-accessible bodily orifices and cavities. Then again, other isolates are food-borne, with some of these having been long associated with naturally fermented cheeses and yogurts. Additionally, because of perceived health benefits to humans and animals, numerous L. rhamnosus strains have been selected for use as so-called probiotics and are often taken in the form of dietary supplements and functional foods. At the genome level, it is anticipated that certain genetic variances will have provided the niche-related phenotypes that augment the flexible adaptiveness of this species, thus enabling its strains to grow and survive in their respective host environments. For this present study, we considered it functionally informative to examine and catalogue the genotype-phenotype variation existing at the cell surface between different L. rhamnosus strains, with the presumption that this might be relatable to habitat preferences and ecological adaptability. Here, we conducted a pan-genomic study involving 13 genomes from L. rhamnosus isolates with various origins. In using a benchmark strain (gut-adapted L. rhamnosus GG for our pan-genome comparison, we had focused our efforts on a detailed examination and description of gene products for certain functionally relevant surface-exposed proteins, each of which in effect might also play a part in niche adaptability among the other strains. Perhaps most significantly of the surface protein loci we had analyzed, it would appear that the spaCBA operon (known to encode SpaCBA-called pili having a mucoadhesive phenotype is a genomic rarity and an uncommon occurrence in L. rhamnosus. However, for any of the so-piliated L. rhamnosus strains, they will likely possess an increased niche-specific fitness, which functionally might presumably be manifested by a protracted transient

  4. A Comparative Pan-Genome Perspective of Niche-Adaptable Cell-Surface Protein Phenotypes in Lactobacillus rhamnosus

    Science.gov (United States)

    Kant, Ravi; Sigvart-Mattila, Pia; Paulin, Lars; Mecklin, Jukka-Pekka; Saarela, Maria; Palva, Airi; von Ossowski, Ingemar

    2014-01-01

    Lactobacillus rhamnosus is a ubiquitously adaptable Gram-positive bacterium and as a typical commensal can be recovered from various microbe-accessible bodily orifices and cavities. Then again, other isolates are food-borne, with some of these having been long associated with naturally fermented cheeses and yogurts. Additionally, because of perceived health benefits to humans and animals, numerous L. rhamnosus strains have been selected for use as so-called probiotics and are often taken in the form of dietary supplements and functional foods. At the genome level, it is anticipated that certain genetic variances will have provided the niche-related phenotypes that augment the flexible adaptiveness of this species, thus enabling its strains to grow and survive in their respective host environments. For this present study, we considered it functionally informative to examine and catalogue the genotype-phenotype variation existing at the cell surface between different L. rhamnosus strains, with the presumption that this might be relatable to habitat preferences and ecological adaptability. Here, we conducted a pan-genomic study involving 13 genomes from L. rhamnosus isolates with various origins. In using a benchmark strain (gut-adapted L. rhamnosus GG) for our pan-genome comparison, we had focused our efforts on a detailed examination and description of gene products for certain functionally relevant surface-exposed proteins, each of which in effect might also play a part in niche adaptability among the other strains. Perhaps most significantly of the surface protein loci we had analyzed, it would appear that the spaCBA operon (known to encode SpaCBA-called pili having a mucoadhesive phenotype) is a genomic rarity and an uncommon occurrence in L. rhamnosus. However, for any of the so-piliated L. rhamnosus strains, they will likely possess an increased niche-specific fitness, which functionally might presumably be manifested by a protracted transient colonization of

  5. Bioengineered fibrin-based niche to direct outgrowth of circulating progenitors into neuron-like cells for potential use in cellular therapy

    Science.gov (United States)

    Tara, S.; Krishnan, Lissy K.

    2015-06-01

    Objective. Autologous cells are considered to be the best choice for use in transplantation therapy. However, the challenges and risks associated with the harvest of transplantable autologous cells limit their successful therapeutic application. The current study explores the possibility of isolating neural progenitor cells from circulating multipotent adult progenitor cells for potential use in cell-based and patient-specific therapy for neurological diseases. Approach. To enable the selection of neural progenitor cells from human peripheral blood mononuclear cells, and to support their lineage maintenance, the composition of a fibrin-based niche was optimized. Morphological examination and specific marker analysis were carried out, employing a qualitative/quantitative polymerase chain reaction followed by immunocytochemistry to: (i) characterize neural progenitor cells in culture; (ii) monitor proliferation/survival; and (iii) track their differentiation status. Main results. The presence of neural progenitors in circulation was confirmed by the presence of nestin+ cells at the commencement of the culture. The isolation, proliferation and differentiation of circulating neural progenitors to neuron-like cells were directed by the engineered niche. Neural cell isolation to near homogeneity was confirmed by the expression of β-III tubulin in ∼95% of cells, whereas microtubule associated protein-2 expression confirmed their ability to differentiate. The concentration of potassium chloride in the niche was found to favour neuron-like cell lengthening, cell-cell contact, and expressions of synaptophysin and tyrosine hydroxylase. Significance. The purpose of this research was to find out if peripheral blood could serve as a potential source of neural progenitors for cell based therapy. The study established that neural progenitors could be selectively isolated from peripheral blood mononuclear cells using a biomimetic niche. The selected cells could multiply and

  6. Illustration of extensive extracellular matrix at the epithelial-mesenchymal interface within the renal stem/progenitor cell niche

    Directory of Open Access Journals (Sweden)

    Minuth Will W

    2012-09-01

    Full Text Available Abstract Background Stem/progenitor cells are promising candidates to treat diseased renal parenchyma. However, implanted stem/progenitor cells are exposed to a harmful atmosphere of degenerating parenchyma. To minimize hampering effects after an implantation investigations are in progress to administer these cells within an artificial polyester interstitum supporting survival. Learning from nature the renal stem/progenitor cell niche appears as a valuable model. At this site epithelial stem/progenitor cells within the collecting duct ampulla face mesenchymal stem/progenitor cells. Both cell types do not have close contact but are separated by a wide interstitium. Methods To analyze extracellular matrix in this particular interstitium, special contrasting for transmission electron microscopy was performed. Kidneys of neonatal rabbits were fixed in solutions containing glutaraldehyde (GA or in combination with cupromeronic blue, ruthenium red and tannic acid. Results GA revealed a basal lamina at the ampulla and a bright but inconspicuously looking interstitial space. In contrast, GA containing cupromeronic blue exhibits numerous proteoglycan braces lining from the ampulla towards the interstitial space. GA containing ruthenium red or tannic acid demonstrates clouds of extracellular matrix protruding from the basal lamina of the ampulla to the surface of mesenchymal stem/progenitor cells. Conclusions The actual data show that the interstitium between epithelial and mesenchymal stem/progenitor cells contains much more and up to date unknown extracellular matrix than earlier observed by classical GA fixation.

  7. Imaging of childhood inflammatory myofibroblastic tumor

    Energy Technology Data Exchange (ETDEWEB)

    Oguz, Berna; Ozcan, Hatice Nursun; Omay, Burak; Ozgen, Burce; Haliloglu, Mithat [Division of Pediatric Radiology, Hacettepe University Faculty of Medicine, Department of Radiology, Altindag / Sihhiye, Ankara (Turkey)

    2015-10-15

    Inflammatory myofibroblastic tumor is a rare benign neoplasm and most commonly involves the lung but occurs in extrapulmonary locations. To present imaging findings in inflammatory myofibroblastic tumors in children based on a single-centre experience. We retrospectively reviewed CT and MRI findings of children diagnosed with inflammatory myofibroblastic tumor in a single institution. We identified 15 children (range: 1-17 years) with inflammatory myofibroblastic tumor. The tumor was localized to the lung (n = 5), mediastinum (n = 3), trachea (n = 1), bronchus (n = 1), abdomen (n = 2) and orbit (n = 3). All the extraorbital tumors were solid masses with homogeneous or heterogeneous enhancement. Four lung tumors and one posterior mediastinal tumor contained calcification. Local recurrence following surgical removal occurred in two children with invasion of the esophagus and of the left atrium in one. Localized masses were seen in all children with orbital tumour. Two of these had episcleritis and perineuritis; one had episcleritis, tendonitis, perineuritis, myositis and dacryoadenitis. The locations and imaging features of inflammatory myofibroblastic tumors are variable. (orig.)

  8. Management of anaplastic lymphoma kinase positive orbito-conjunctival inflammatory myofibroblastic tumor with crizotinib.

    Science.gov (United States)

    Kiratli, Hayyam; Uzun, Salih; Varan, Ali; Akyüz, Canan; Orhan, Diclehan

    2016-06-01

    Inflammatory myofibroblastic tumor (IMT) is a distinct mesenchymal neoplasm of myofibroblastic spindle cells associated with an inflammatory infiltrate formed by lymphocytes, eosinophils, and plasma cells in a myxoid or collagenous stroma. This tumor has a predilection for children and young adults and most commonly occurs in the lungs, retroperitoneum, abdomen, and pelvis. Ocular and orbital involvement is exceedingly rare. We describe a case of IMT in a 7-year-old girl involving the cornea, conjunctiva, and the anterior orbit treated with crizotinib, resulting in complete tumor remission. PMID:27312965

  9. Mesenteric inflammatory myofibroblastic tumor: MRI and CT imaging correlated to anatomical pathology.

    Science.gov (United States)

    Kirchgesner, Th; Danse, E; Sempoux, Ch; Annet, L; Dragean, Ch Anca; Trefois, P; Abbes Orabi, N; Kartheuser, A

    2014-01-01

    Inflammatory myofibroblastic tumor (IMT) is a rare tumor, classified by WHO of intermediate biological potential with tendency for local recurrence and small risk for distant metastasis. Histologically IMT is a mixture of inflamma- tory cells and myofibroblastic spindle cells proliferation. To our knowledge there is no MRI description of mesenteric IMT in the literature. We would like to emphasize the correlation between medical imaging and anatomical pathology based on our experience of a mesenteric IMT in a 28-year-old patient. PMID:25597213

  10. 干细胞niche与心肌细胞分化的调控机制研究%Regulatory Mechanism of Niche on Stem Cells Differentiation to Cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    余细勇

    2011-01-01

    Stem cells are the special cells of self-renewal and differentiation potential. Recent studies found that the biological behaviors of stem cells are highly dependent on their microenvironment (niche). There are two roles of niche on stem cells: the direct effects between cell contacts, and the indirect effects such as matrix and cytokines which involve in several signal transduction pathways and their cross-talks. Here, we mainly describe the effects of bone marrow niche on mesenchymal stem cells (SMC), and the regulatory mechanisms of MSC differentiation into myocardial cells.%干细胞是一类具有自我更新和多向分化潜能的特殊细胞.研究发现,干细胞的生物学行为高度依赖于其所处的微环境(niche).Niche对干细胞的作用分为细胞与细胞之间的直接作用和基质及众多细胞因子对干细胞的间接作用,涉及多条信号转导通路及其相互作用.本文主要介绍骨髓干细胞的niche对间充质干细胞(MSC)的调控,并探讨MSC向心肌细胞分化的调控机制.

  11. Hic-5 Promotes the Hypertrophic Scar Myofibroblast Phenotype by Regulating the TGF-β1 Autocrine Loop

    OpenAIRE

    Dabiri, Ganary; Tumbarello, David A.; Turner, Christopher E.; Water, Livingston Van De

    2008-01-01

    Following severe traumatic or thermal injury to the dermis, hypertrophic scars (HTS) often develop in humans. These scar fibroblasts (HTSF) retain the myofibroblast phenotype persistently, rather than transiently as in acute wounds. These pathogenic myofibroblasts constitutively express smooth muscle cell α-actin (SMAA), deposit an excessive amount of extracellular matrix (ECM) proteins, are highly contractile, and stably display large focal adhesions. Increasing evidence supports a mechanism...

  12. Bleomycin-Treated Chimeric Thy1-Deficient Mice with Thy1-Deficient Myofibroblasts and Thy-Positive Lymphocytes Resolve Inflammation without Affecting the Fibrotic Response

    Directory of Open Access Journals (Sweden)

    Pazit Y. Cohen

    2015-01-01

    Full Text Available Lung fibrosis is characterized by abnormal accumulation of fibroblasts in the interstitium of the alveolar space. Two populations of myofibroblasts, distinguished by Thy1 expression, are detected in human and murine lungs. Accumulation of Thy1-negative (Thy1− myofibroblasts was shown in the lungs of humans with idiopathic pulmonary fibrosis (IPF and of bleomycin-treated mice. We aimed to identify genetic changes in lung myofibroblasts following Thy1 crosslinking and assess the impact of specific lung myofibroblast Thy1-deficiency, in vivo, in bleomycin-injured mouse lungs. Thy1 increased in mouse lung lymphocytes following bleomycin injury but decreased in myofibroblasts when fibrosis was at the highest point (14 days, as assessed by immunohistochemistry. Using gene chip analysis, we detected that myofibroblast Thy1 crosslinking mediates downregulation of genes promoting cell proliferation, survival, and differentiation, and reduces production of extracellular matrix (ECM components, while concurrently mediating the upregulation of genes known to foster inflammation and immunological functions. Chimeric Thy1-deficient mice with Thy1+ lymphocytes and Thy1− myofibroblasts showed fibrosis similar to wild-type mice and an increased number of CD4/CD25 regulatory T cells, with a concomitant decrease in inflammation. Lung myofibroblasts downregulate Thy1 expression to increase their proliferation but to diminish the in vivo inflammatory milieu. Inflammation is not essential for evolution of fibrosis as was previously stated.

  13. Inflammatory myofibroblastic tumor : A case report

    International Nuclear Information System (INIS)

    The inflammatory myofibroblastic tumor (inflammatory pseudotumor) is a rarely occurring soft tissue lesion of unknown etiology. It can be of any location, but commonly it is found in lungs. It has been considered as a nonneoplastic reactive inflammatory lesion, but nowadays, confusion and dispute about its character is increasing due to its high recurrence rate and metastasis. We present a patient who had been diagnosed with an inflammatory pseudotumor in the right maxilla area, 1 year before visiting our hospital. After that, her pain and swelling did not resolved and she visit our hospital. On radiographic examination, aggressively infiltrative growth of the lesion with destruction of adjacent bony structure was noted. We found unusual aggressiveness of the inflammatory myofibroblastic tumor of the head and neck region. Because the typical behavior of the inflammatory myofibroblastic tumor is not defined yet, we recommend the surgical excision of the lesion and close follow-up

  14. The role of myofibroblasts in the development of osteoradionecrosis in a newly established rabbit model.

    Science.gov (United States)

    Zong, Chunlin; Cai, Bolei; Wen, Xinxin; Alam, Syed; Chen, Yuanli; Guo, Yuxuan; Liu, Yanpu; Tian, Lei

    2016-06-01

    This study aimed to establish a proper animal model of osteoradionecrosis of jaws (ORNJ) and to observe preliminarily the characteristics of myofibroblasts, the key effector cell of fibrosis, in ORNJ. Rabbit mandibles were irradiated at three different doses based on a human equivalent radiation schedule, and examined by gross manifestation, single-photon emission computed tomography (SPECT), micro-computed tomography, sequential fluorochrome labeling, and histology. Immunohistochemistry staining of α-SMA was applied to detect the existence of myofibroblasts. The exposed necrotic bone, which is the main indication of ORNJ, started to be observed at all rabbits at 9 Gy. With the radiation dose increasing, the microarchitecture of the irradiated mandibles was more destroyed, the metabolism and mineralization of the irradiated mandibles diminished, the osteocytes number decreased, and more mature bones were substituted by fibrosis in the irradiated mandibles. In addition, as the radiation dose increased, the myofibroblast number increased and collected around the separated sequestrum, which indicated that myofibroblasts might relate to the pathogenesis of ORNJ. In summary, a clinically translational ORNJ model was successfully established in our study, and the role of myofibroblasts in the pathogenesis of ORNJ is described for the first time. PMID:27150352

  15. Microcavity arrays as an in vitro model system of the bone marrow niche for hematopoietic stem cells.

    Science.gov (United States)

    Wuchter, Patrick; Saffrich, Rainer; Giselbrecht, Stefan; Nies, Cordula; Lorig, Hanna; Kolb, Stephanie; Ho, Anthony D; Gottwald, Eric

    2016-06-01

    In previous studies human mesenchymal stromal cells (MSCs) maintained the "stemness" of human hematopoietic progenitor cells (HPCs) through direct cell-cell contact in two-dimensional co-culture systems. We establish a three-dimensional (3D) co-culture system based on a custom-made chip, the 3(D)-KITChip, as an in vitro model system of the human hematopoietic stem cell niche. This array of up to 625 microcavities, with 300 μm size in each orientation, was inserted into a microfluidic bioreactor. The microcavities of the 3(D)-KITChip were inoculated with human bone marrow MSCs together with umbilical cord blood HPCs. MSCs used the microcavities as a scaffold to build a complex 3D mesh. HPCs were distributed three-dimensionally inside this MSC network and formed ß-catenin- and N-cadherin-based intercellular junctions to the surrounding MSCs. Using RT(2)-PCR and western blots, we demonstrate that a proportion of HPCs maintained the expression of CD34 throughout a culture period of 14 days. In colony-forming unit assays, the hematopoietic stem cell plasticity remained similar after 14 days of bioreactor co-culture, whereas monolayer co-cultures showed increasing signs of HPC differentiation and loss of stemness. These data support the notion that the 3D microenvironment created within the microcavity array preserves vital stem cell functions of HPCs more efficiently than conventional co-culture systems. PMID:26829941

  16. Special Morphological Features at the Interface of the Renal Stem/Progenitor Cell Niche Force to Reinvestigate Transport of Morphogens During Nephron Induction

    OpenAIRE

    Minuth, Will W.; Denk, Lucia

    2016-01-01

    Abstract Formation of a nephron depends on reciprocal signaling of different morphogens between epithelial and mesenchymal cells within the renal stem/progenitor cell niche. Previously, it has been surmised that a close proximity exists between both involved cell types and that morphogens are transported between them by diffusion. However, actual morphological data illustrate that mesenchymal and epithelial stem/progenitor cell bodies are separated by a striking interface. Special fixation of...

  17. The participation of the Na+-Ca2+ exchanger in primary cardiac myofibroblast migration, contraction, and proliferation.

    Science.gov (United States)

    Raizman, Joshua E; Komljenovic, Jelena; Chang, Rose; Deng, Cicie; Bedosky, Kristen M; Rattan, Sunil G; Cunnington, Ryan H; Freed, Darren H; Dixon, Ian M C

    2007-11-01

    Cardiac ventricular myofibroblast motility, proliferation, and contraction contribute to post-myocardial infarct wound healing, infarct scar formation, and remodeling of the ventricle remote to the site of infarction. The Na+-Ca2+ exchanger (NCX1) is involved in altered calcium handling in cardiac myocytes during cardiac remodeling associated with heart failure, however, its role in cardiac myofibroblast cell function is unexplored. In this study we investigated the involvement of NCX1 as well as the role of non-selective-cation channels (NSCC) in cardiac myofibroblast cell function in vitro. Immunofluorescence and Western blots revealed that P1 cells upregulate alpha-smooth muscle actin (alphaSMA) and embryonic smooth muscle myosin heavy chain (SMemb) expression. NCX1 mRNA and proteins as well as Ca(v)1.2a protein are also expressed in P1 myofibroblasts. Myofibroblast motility in the presence of 50 ng/ml PDGF-BB was blocked with AG1296. Myofibroblast motility, contraction, and proliferation were sensitive to KB-R7943, a specific NCX1 reverse-mode inhibitor. In contrast, only proliferation and contraction, but not motility were sensitive to nifedipine, while gadolinium (NSCC blocker) was only associated with decreased motility. ML-7 treatment was associated with inhibition of the chemotactic response and contraction. Thus cardiac myofibroblast chemotaxis, contraction, and proliferation were sensitive to different pharmacologic treatments suggesting that regulation of transplasmalemmal calcium movements may be important in growth factor receptor-mediated processes. NCX1 may represent an important moiety in suppression of myofibroblast functions. PMID:17541957

  18. bantam miRNA is important for Drosophila blood cell homeostasis and a regulator of proliferation in the hematopoietic progenitor niche

    International Nuclear Information System (INIS)

    Highlights: • bantam miRNA is endogenously expressed in the hematopoietic progenitor niche. • bantam is necessary and sufficient to induce cellular proliferation in the PSC. • bantam is upstream of the Insulin Receptor signaling pathway. • A model for positive regulation of hematopoietic niche growth is proposed. - Abstract: The Drosophila hematopoietic system is utilized in this study to gain novel insights into the process of growth control of the hematopoietic progenitor niche in blood development. The niche microenvironment is an essential component controlling the balance between progenitor populations and differentiated, mature blood cells and has been shown to lead to hematopoietic malignancies in humans when misregulated. MicroRNAs are one class of regulators associated with blood malignancies; however, there remains a relative paucity of information about the role of miRNAs in the niche. Here we demonstrate that bantam miRNA is endogenously active in the Drosophila hematopoietic progenitor niche, the posterior signaling center (PSC), and functions in the primary hematopoietic organ, the lymph gland, as a positive regulator of growth. Loss of bantam leads to a significant reduction in the PSC and overall lymph gland size, as well as a loss of the progenitor population and correlative premature differentiation of mature hemocytes. Interestingly, in addition to being essential for proper lymph gland development, we have determined bantam to be a novel upstream component of the insulin signaling cascade in the PSC and have unveiled dMyc as one factor central to bantam activity. These important findings identify bantam as a new hematopoietic regulator, place it in an evolutionarily conserved signaling pathway, present one way in which it is regulated, and provide a mechanism through which it facilitates cellular proliferation in the hematopoietic niche

  19. bantam miRNA is important for Drosophila blood cell homeostasis and a regulator of proliferation in the hematopoietic progenitor niche

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Victoria; Tokusumi, Tsuyoshi; Tokusumi, Yumiko; Schulz, Robert A., E-mail: rschulz@nd.edu

    2014-10-24

    Highlights: • bantam miRNA is endogenously expressed in the hematopoietic progenitor niche. • bantam is necessary and sufficient to induce cellular proliferation in the PSC. • bantam is upstream of the Insulin Receptor signaling pathway. • A model for positive regulation of hematopoietic niche growth is proposed. - Abstract: The Drosophila hematopoietic system is utilized in this study to gain novel insights into the process of growth control of the hematopoietic progenitor niche in blood development. The niche microenvironment is an essential component controlling the balance between progenitor populations and differentiated, mature blood cells and has been shown to lead to hematopoietic malignancies in humans when misregulated. MicroRNAs are one class of regulators associated with blood malignancies; however, there remains a relative paucity of information about the role of miRNAs in the niche. Here we demonstrate that bantam miRNA is endogenously active in the Drosophila hematopoietic progenitor niche, the posterior signaling center (PSC), and functions in the primary hematopoietic organ, the lymph gland, as a positive regulator of growth. Loss of bantam leads to a significant reduction in the PSC and overall lymph gland size, as well as a loss of the progenitor population and correlative premature differentiation of mature hemocytes. Interestingly, in addition to being essential for proper lymph gland development, we have determined bantam to be a novel upstream component of the insulin signaling cascade in the PSC and have unveiled dMyc as one factor central to bantam activity. These important findings identify bantam as a new hematopoietic regulator, place it in an evolutionarily conserved signaling pathway, present one way in which it is regulated, and provide a mechanism through which it facilitates cellular proliferation in the hematopoietic niche.

  20. Ischemic preconditioning protects against gap junctional uncoupling in cardiac myofibroblasts.

    Science.gov (United States)

    Sundset, Rune; Cooper, Marie; Mikalsen, Svein-Ole; Ytrehus, Kirsti

    2004-01-01

    Ischemic preconditioning increases the heart's tolerance to a subsequent longer ischemic period. The purpose of this study was to investigate the role of gap junction communication in simulated preconditioning in cultured neonatal rat cardiac myofibroblasts. Gap junctional intercellular communication was assessed by Lucifer yellow dye transfer. Preconditioning preserved intercellular coupling after prolonged ischemia. An initial reduction in coupling in response to the preconditioning stimulus was also observed. This may protect neighboring cells from damaging substances produced during subsequent regional ischemia in vivo, and may preserve gap junctional communication required for enhanced functional recovery during subsequent reperfusion. PMID:16247851

  1. EPAC expression and function in cardiac fibroblasts and myofibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Olmedo, Ivonne; Muñoz, Claudia; Guzmán, Nancy; Catalán, Mabel; Vivar, Raúl; Ayala, Pedro; Humeres, Claudio; Aránguiz, Pablo [Departamento de Química Farmacológica y Toxicológica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile (Chile); García, Lorena [Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile (Chile); Velarde, Victoria [Departamento de Ciencias Fisiológicas, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile (Chile); Díaz-Araya, Guillermo, E-mail: gadiaz@ciq.uchile.cl [Departamento de Química Farmacológica y Toxicológica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile (Chile)

    2013-10-15

    In the heart, cardiac fibroblasts (CF) and cardiac myofibroblasts (CMF) are the main cells responsible for wound healing after cardiac insult. Exchange protein activated by cAMP (EPAC) is a downstream effector of cAMP, and it has been not completely studied on CF. Moreover, in CMF, which are the main cells responsible for cardiac healing, EPAC expression and function are unknown. We evaluated in both CF and CMF the effect of transforming growth factor β1 (TGF-β1) on EPAC-1 expression. We also studied the EPAC involvement on collagen synthesis, adhesion, migration and collagen gel contraction. Method: Rat neonatal CF and CMF were treated with TGF-β1 at different times and concentrations. EPAC-1 protein levels and Rap1 activation were measured by western blot and pull down assay respectively. EPAC cellular functions were determined by adhesion, migration and collagen gel contraction assay; and collagen expression was determined by western blot. Results: TGF-β1 through Smad and JNK significantly reduced EPAC-1 expression in CF, while in CMF this cytokine increased EPAC-1 expression through ERK1/2, JNK, p38, AKT and Smad3. EPAC activation was able to induce higher Rap1-GTP levels in CMF than in CF. EPAC and PKA, both cAMP effectors, promoted CF and CMF adhesion on fibronectin, as well as CF migration; however, this effect was not observed in CMF. EPAC but not PKA activation mediated collagen gel contraction in CF, while in CMF both PKA and EPAC mediated collagen gel contraction. Finally, the EPAC and PKA activation reduced collagen synthesis in CF and CMF. Conclusion: TGF-β1 differentially regulates the expression of EPAC in CF and CMF; and EPAC regulates differentially CF and CMF functions associated with cardiac remodeling. - Highlights: • TGF-β1 regulates EPAC-1 expression in cardiac fibroblast and myofibroblast. • Rap-1GTP levels are higher in cardiac myofibroblast than fibroblast. • EPAC-1 controls adhesion, migration and collagen synthesis in cardiac

  2. EPAC expression and function in cardiac fibroblasts and myofibroblasts

    International Nuclear Information System (INIS)

    In the heart, cardiac fibroblasts (CF) and cardiac myofibroblasts (CMF) are the main cells responsible for wound healing after cardiac insult. Exchange protein activated by cAMP (EPAC) is a downstream effector of cAMP, and it has been not completely studied on CF. Moreover, in CMF, which are the main cells responsible for cardiac healing, EPAC expression and function are unknown. We evaluated in both CF and CMF the effect of transforming growth factor β1 (TGF-β1) on EPAC-1 expression. We also studied the EPAC involvement on collagen synthesis, adhesion, migration and collagen gel contraction. Method: Rat neonatal CF and CMF were treated with TGF-β1 at different times and concentrations. EPAC-1 protein levels and Rap1 activation were measured by western blot and pull down assay respectively. EPAC cellular functions were determined by adhesion, migration and collagen gel contraction assay; and collagen expression was determined by western blot. Results: TGF-β1 through Smad and JNK significantly reduced EPAC-1 expression in CF, while in CMF this cytokine increased EPAC-1 expression through ERK1/2, JNK, p38, AKT and Smad3. EPAC activation was able to induce higher Rap1-GTP levels in CMF than in CF. EPAC and PKA, both cAMP effectors, promoted CF and CMF adhesion on fibronectin, as well as CF migration; however, this effect was not observed in CMF. EPAC but not PKA activation mediated collagen gel contraction in CF, while in CMF both PKA and EPAC mediated collagen gel contraction. Finally, the EPAC and PKA activation reduced collagen synthesis in CF and CMF. Conclusion: TGF-β1 differentially regulates the expression of EPAC in CF and CMF; and EPAC regulates differentially CF and CMF functions associated with cardiac remodeling. - Highlights: • TGF-β1 regulates EPAC-1 expression in cardiac fibroblast and myofibroblast. • Rap-1GTP levels are higher in cardiac myofibroblast than fibroblast. • EPAC-1 controls adhesion, migration and collagen synthesis in cardiac

  3. Revisiting the Role of the Myofibroblast in Socket Surgery: An Immunohistochemical Study

    Science.gov (United States)

    Abdulhafez, Mohamed H.; Fouad, Yousef A.; Rashed, Hazem O.; Osman, Wesam M.

    2016-01-01

    Purpose: To determine the impact of a single injection of various anti-inflammatory, antimitotic, and antiangiogenic agents on the cell count of myofibroblasts in an eviscerated socket. Methods: One eye from 15 skeletally mature New Zealand white rabbits was eviscerated, and the rabbits were divided into 5 groups. Each group of 3 rabbits received a 0.1 ml subconjunctival injection of a different agent. Group I received bevacizumab 25 mg/ml, group II received triamcinolone 40 mg/ml, group III received 5-fluorouracil 50 mg/ml, group IV received mitomycin-C 0.4 mg/ml, while group V was the control group and received no injections. The animals were euthanized 19 days after evisceration and conjunctival samples were submitted for histopathological examination. Monoclonal α-smooth muscle actin antibody was applied, and the mean of 5 readings of the number of myofibroblasts was recorded in each slide. Results: The mean count of myofibroblasts was highest for the control group and all groups achieved a statistically significant reduction in myofibroblast count compared with the control group. Sorting the means showed that Group IV (mitomycin-C) achieved the lowest mean value (p = 0.000006) followed by triamcinolone (p = 0.00048), while group I (bevacizumab) achieved the least reduction in myofibroblast count (p = 0.00148). Conclusion: Until newer antimyofibroblast medications and antibodies are commercially available, a single injection of mitomycin-C or triamcinolone during surgery achieves the highest mean reduction of myofibroblast count. PMID:26079106

  4. Niche-independent symmetrical self-renewal of a mammalian tissue stem cell.

    Directory of Open Access Journals (Sweden)

    Luciano Conti

    2005-09-01

    Full Text Available Pluripotent mouse embryonic stem (ES cells multiply in simple monoculture by symmetrical divisions. In vivo, however, stem cells are generally thought to depend on specialised cellular microenvironments and to undergo predominantly asymmetric divisions. Ex vivo expansion of pure populations of tissue stem cells has proven elusive. Neural progenitor cells are propagated in combination with differentiating progeny in floating clusters called neurospheres. The proportion of stem cells in neurospheres is low, however, and they cannot be directly observed or interrogated. Here we demonstrate that the complex neurosphere environment is dispensable for stem cell maintenance, and that the combination of fibroblast growth factor 2 (FGF-2 and epidermal growth factor (EGF is sufficient for derivation and continuous expansion by symmetrical division of pure cultures of neural stem (NS cells. NS cells were derived first from mouse ES cells. Neural lineage induction was followed by growth factor addition in basal culture media. In the presence of only EGF and FGF-2, resulting NS cells proliferate continuously, are diploid, and clonogenic. After prolonged expansion, they remain able to differentiate efficiently into neurons and astrocytes in vitro and upon transplantation into the adult brain. Colonies generated from single NS cells all produce neurons upon growth factor withdrawal. NS cells uniformly express morphological, cell biological, and molecular features of radial glia, developmental precursors of neurons and glia. Consistent with this profile, adherent NS cell lines can readily be established from foetal mouse brain. Similar NS cells can be generated from human ES cells and human foetal brain. The extrinsic factors EGF plus FGF-2 are sufficient to sustain pure symmetrical self-renewing divisions of NS cells. The resultant cultures constitute the first known example of tissue-specific stem cells that can be propagated without accompanying

  5. Advance of study on cancer stem cell niche%肿瘤干细胞niche的研究进展

    Institute of Scientific and Technical Information of China (English)

    徐皓; 林志雄

    2010-01-01

    Cancer stem cell niche provides a relatively stable microenvironment for cancer stem cell (CSC)existence,proliferation and differentiation.This microenvironment consists of kinds of cells,stroma and cytokines, etc. Within it , CSC can resist chemoradiotherapy. It has been shown that destruction of the microen vironment can significantly enhance the effect of chemoradiotherapy and improve prognosis of cancer patients.%肿瘤干细胞niche为肿瘤干细胞生存以及增殖分化提供了相对稳定的微环境,这一微环境由各种细胞、基质以及多种细胞因子等构成.在这一微环境中,肿瘤干细胞能够耐受放化疗.文献报道,破坏这种微环境能显著增强放化疗效果,从而改善肿瘤患者的预后.

  6. Direct Measurements of Human Colon Crypt Stem Cell Niche Genetic Fidelity: The Role of Chance in Non-Darwinian Mutation Selection

    Directory of Open Access Journals (Sweden)

    Haeyoun eKang

    2013-10-01

    Full Text Available Perfect human stem cell genetic fidelity would prevent aging and cancer. However, perfection would be difficult to achieve, and aging is universal and cancers common. A hypothesis is that because mutations are inevitable over a human lifetime, downstream mechanisms have evolved to manage the deleterious effects of beneficial and lethal mutations. In the colon, a crypt stem cell architecture reduces the number of mitotic cells at risk for mutation accumulation, and multiple niche stem cells ensure that a lethal mutation within any single stem cell does not lead to crypt death. In addition, the architecture of the colon crypt stem cell niche may harness probability or chance to randomly discard many beneficial mutations that might lead to cancer. An analysis of somatic chromosome copy number alterations (CNAs reveals a lack of perfect fidelity in individual normal human crypts, with age-related increases and higher frequencies in ulcerative colitis, a proliferative, inflammatory disease. The age-related increase in somatic CNAs appears consistent with relatively normal replication error and cell division rates. Surprisingly, and similar to point mutations in cancer genomes, the types of crypt mutations were more consistent with random fixation rather than selection. In theory, a simple non-Darwinian way to nullify selection is to reduce the size of the reproducing population. Fates are more determined by chance rather than selection in very small populations, and therefore selection may be minimized within small crypt niches. The desired effect is that many beneficial mutations that might lead to cancer are randomly lost by drift rather than fixed by selection. The subdivision of the colon into multiple very small stem cell niches may trade Darwinian evolution for non-Darwinian somatic cell evolution, capitulating to aging but reducing cancer risks.

  7. Vascular-derived TGF-β increases in the stem cell niche and perturbs neuro-genesis during aging and following irradiation in the adult mouse brain

    International Nuclear Information System (INIS)

    Neuro-genesis decreases during aging and following cranial radiotherapy, causing a progressive cognitive decline that is currently untreatable. However, functional neural stem cells remained present in the sub-ventricular zone of high dose irradiated and aged mouse brains. We therefore investigated whether alterations in the neurogenic niches are perhaps responsible for the neuro-genesis decline. This hypothesis was supported by the absence of proliferation of neural stem cells that were engrafted into the vascular niches of irradiated host brains. Moreover, we observed a marked increase in TGF-β1 production by endothelial cells in the stem cell niche in both middle-aged and irradiated mice. In co-cultures, irradiated brain endothelial cells induced the apoptosis of neural stem/progenitor cells via TGF-β/Smad3 signalling. Strikingly, the blockade of TGF-β signalling in vivo using a neutralizing antibody or the selective inhibitor SB-505124 significantly improved neuro-genesis in aged and irradiated mice, prevented apoptosis and increased the proliferation of neural stem/progenitor cells. These findings suggest that anti-TGF-β-based therapy may be used for future interventions to prevent neurogenic collapse following radiotherapy or during aging. (authors)

  8. Lung Myofibroblasts Are Characterized by Down-Regulated Cyclooxygenase-2 and Its Main Metabolite, Prostaglandin E2

    Science.gov (United States)

    Gabasa, Marta; Royo, Dolores; Molina-Molina, Maria; Roca-Ferrer, Jordi; Pujols, Laura; Picado, Cesar

    2013-01-01

    Background Prostaglandin E2 (PGE2), the main metabolite of cyclooxygenase (COX), is a well-known anti-fibrotic agent. Moreover, myofibroblasts expressing α-smooth muscle actin (α-SMA), fibroblast expansion and epithelial-mesenchymal transition (EMT) are critical to the pathogenesis of idiopathic pulmonary fibrosis (IPF). Our aim was to investigate the expression of COX-2 and PGE2 in human lung myofibroblasts and establish whether fibroblast-myofibroblast transition (FMT) and EMT are associated with COX-2 and PGE2 down-regulation. Methods Fibroblasts obtained from IPF patients (n = 6) and patients undergoing spontaneous pneumothorax (control, n = 6) and alveolar epithelial cell line A549 were incubated with TGF-β1 and FMT and EMT markers were evaluated. COX-2 and α-SMA expression, PGE2 secretion and cell proliferation were measured after IL-1β and PGE2 incubation. Results Myofibroblasts from both control and IPF fibroblast cultures stimulated with IL-1β showed no COX-2 expression. IPF fibroblasts showed increased myofibroblast population and reduced COX-2 expression in response to IL-1β. TGF-β1 increased the number of myofibroblasts in a time-dependent manner. In contrast, TGF-β1 induced slight COX-2 expression at 4 h (without increase in myofibroblasts) and 24 h, but not at 72 h. Both IPF and control cultures incubated with TGF-β1 for 72 h showed diminished COX-2 induction, PGE2 secretion and α-SMA expression after IL-1β addition. The latter decreased proliferation in fibroblasts but not in myofibroblasts. A549 cells incubated with TGF-β1 for 72 h showed down-regulated COX-2 expression and low basal PGE2 secretion in response to IL-1β. Immuno-histochemical analysis of IPF lung tissue showed no COX-2 immuno-reactivity in myofibroblast foci. Conclusions Myofibroblasts are associated with COX-2 down-regulation and reduced PGE2 production, which could be crucial in IPF development and progression. PMID:23755232

  9. Stem Cell Interaction with Somatic Niche May Hold the Key to Fertility Restoration in Cancer Patients

    OpenAIRE

    Deepa Bhartiya; Kalpana Sriraman; Seema Parte

    2012-01-01

    The spontaneous return of fertility after bone marrow transplantation or heterotopic grafting of cryopreserved ovarian cortical tissue has surprised many, and a possible link with stem cells has been proposed. We have reviewed the available literature on ovarian stem cells in adult mammalian ovaries and presented a model that proposes that the ovary harbors two distinct populations of stem cells, namely, pluripotent, quiescent, very small embryonic-like stem cells (VSELs), and slightly larger...

  10. Periodontal ligament stem cell niche and periodontal tissue regeneration%牙周膜干细胞巢与牙周组织再生

    Institute of Scientific and Technical Information of China (English)

    孙静

    2011-01-01

    牙周膜干细胞巢是牙周膜干细胞周围的微环境,由干细胞周围的支持细胞、黏附分子和基质组成,其在牙周组织的发育、牙周病的发生与发展以及牙周组织再生等方面具有重要的作用。本文将从影响巢结构稳定的因素及其在牙周组织再生中的作用等方面作一综述。%Periodontal ligament stem cell niche is the micro-environment surrounding of the periodontal stem cells, containing the supporting cells of stem cells, adhesion molecules and matrix composition. It is maybe more reasonable to make the periodontal stem cells and their niche to be a whole functional subject during physiologic and pathologic processes. We will review the factors that related to periodontal ligament stem cell niche especially in the process of periodontal tissue regeneration.

  11. Kinetic modeling reveals a common death niche for newly formed and mature B cells.

    Directory of Open Access Journals (Sweden)

    Gitit Shahaf

    Full Text Available BACKGROUND: B lymphocytes are subject to elimination following strong BCR ligation in the absence of appropriate second signals, and this mechanism mediates substantial cell losses during late differentiation steps in the bone marrow and periphery. Mature B cells may also be eliminated through this mechanism as well as through normal turnover, but the population containing mature cells destined for elimination has not been identified. Herein, we asked whether the transitional 3 (T3 subset, which contains most newly formed cells undergoing anergic death, could also include mature B cells destined for elimination. METHODOLOGY/PRINCIPAL FINDINGS: To interrogate this hypothesis and its implications, we applied mathematical models to previously generated in vivo labeling data. Our analyses reveal that the death rate of T3 B cells is far higher than the death rates of all other splenic B cell subpopulations. Further, the model, in which the T3 pool includes both newly formed and mature primary B cells destined for apoptotic death, shows that this cell loss may account for nearly all mature B cell turnover. CONCLUSIONS/SIGNIFICANCE: This finding has implications for the mechanism of normal mature B cell turnover.

  12. Synergistic role of three dimensional niche and hypoxia on conservation of cancer stem cell phenotype.

    Science.gov (United States)

    Gorgun, Cansu; Ozturk, Sukru; Gokalp, Sevtap; Vatansever, Seda; Gurhan, S Ismet Deliloglu; Urkmez, Aylin Sendemir

    2016-09-01

    Hypoxia is a pathalogical condition in which tissues are deprived of adequate oxygen supply. The hypoxia effect on tumors has a critically important role on maintenance of cancer stem cell phenotype. The aim of this study is to investigate the effects of hypoxia on cancer stem cells on three dimensional (3D) in vitro culture models. Osteosarcoma stem cells characterized by CD133 surface protein were isolated from osteosarcoma cell line (SaOS-2) by magnetic-activated cell sorting (MACS) technique. Isolated CD133(+) and CD133(-) cells were cultivated under hypoxic (1% O2) and normoxic conditions (21% O2) for 3 days. For the 3D model, bacterial cellulose scaffold was used as the culture substrate. 3D morphologies of cells were examined by scanning electron microscopy (SEM); RT-PCR and immunocytochemistry staining were used to demonstrate conservation of the cancer stem cell phenotype in 3D environment under hypoxic conditions. Cell viability was shown by MTT assay on 3. and 7. culture days. This study is seen as an introduction to develop a 3D hypoxic cancer stem cell based tumor model to study CSC behavior and tumor genesis in vitro. PMID:26718870

  13. Histamine inhibits differentiation of skin fibroblasts into myofibroblasts.

    Science.gov (United States)

    Lin, Lin; Yamagata, Kaoru; Nakayamada, Shingo; Sawamukai, Norifumi; Yamaoka, Kunihiro; Sakata, Kei; Nakano, Kazuhisa; Tanaka, Yoshiya

    2015-07-31

    Histamine and TGF-β, major mediators secreted by mast cells, are involved in skin inflammation and play critical roles in the pathogenesis of systemic sclerosis. However, the roles of signaling mechanisms in the development of skin fibrosis remain largely unclear. Here we show that histamine suppressed the expression of α smooth muscle actin (αSMA), a marker of myofibroblasts, induced by TGF-β1 in skin fibroblasts. Histamine H1-receptor (H1R), but not H2-receptor (H2R) or H4-receptor (H4R), was expressed on skin fibroblasts at both mRNA and protein levels. Interestingly, an H1R antagonist, but not H2R or H4R antagonists, antagonized the histamine-mediated suppression of αSMA expression by TGF-β1. Correspondingly, phosphorylated Smad2 was detected after treatment with TGF-β1, whereas the addition of histamine inhibited this phosphorylation. Taken together, histamine-H1R decreased TGF-β1-mediated Smad2 phosphorylation and inhibited differentiation of skin fibroblasts into myofibroblasts. PMID:26036574

  14. Hypoxic remodelling of Ca{sup 2+} stores does not alter human cardiac myofibroblast invasion

    Energy Technology Data Exchange (ETDEWEB)

    Riches, K.; Hettiarachchi, N.T.; Porter, K.E. [Leeds Institute for Genetics, Health and Therapeutics, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT (United Kingdom); Peers, C., E-mail: c.s.peers@leeds.ac.uk [Leeds Institute for Genetics, Health and Therapeutics, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2010-12-17

    Research highlights: {yields} Bradykinin promotes migration and proliferation of myofibroblasts. {yields} Such activity is Ca{sup 2+}-dependent and occurs under hypoxic conditions. {yields} Hypoxia increased myofibroblast Ca{sup 2+} stores but not influx evoked by bradykinin. {yields} Myofibroblast migration and proliferation was unaffected by hypoxia. -- Abstract: Cardiac fibroblasts are the most abundant cell type in the heart, and play a key role in the maintenance and repair of the myocardium following damage such as myocardial infarction by transforming into a cardiac myofibroblast (CMF) phenotype. Repair occurs through controlled proliferation and migration, which are Ca{sup 2+} dependent processes, and often requires the cells to operate within a hypoxic environment. Angiotensin converting enzyme (ACE) inhibitors reduce infarct size through the promotion of bradykinin (BK) stability. Although CMF express BK receptors, their activity under the reduced O{sub 2} conditions that occur following infarct are entirely unexplored. Using Fura-2 microfluorimetry on primary human CMF, we found that hypoxia significantly increased the mobilisation of Ca{sup 2+} from intracellular stores in response to BK whilst capacitative Ca{sup 2+} entry (CCE) remained unchanged. The enhanced store mobilisation was due to a striking increase in CMF intracellular Ca{sup 2+}-store content under hypoxic conditions. However, BK-induced CMF migration or proliferation was not affected following hypoxic exposure, suggesting that Ca{sup 2+} influx rather than mobilisation is of primary importance in CMF migration and proliferation.

  15. Stem Cell Niche is Partially Lost during Follicular Plucking: A Preliminary Pilot Study

    OpenAIRE

    Kumar, Anil; Gupta, Somesh; Mohanty, Sujata; Bhargava, Balram; Airan, Balram

    2013-01-01

    Background: Clinical hair transplant studies have revealed that follicular unit extraction (FUE) is superior in terms of stable hair growth in comparison to follicular plucking (FP). Various reasons have been cited for this clinical outcome. FUE and FP are employed to obtain the hair follicle units for hair transplant and recently for cell based therapies in vitiligo. However, there is no scientific data available on the comparison of stem cell fraction in the cell suspension obtained by FUE ...

  16. Cancer Microenvironment: What Can We Learn from the Stem Cell Niche

    OpenAIRE

    Lukas Lacina; Jan Plzak; Ondrej Kodet; Pavol Szabo; Martin Chovanec; Barbora Dvorankova; Karel Smetana Jr.

    2015-01-01

    Epidermal stem cells (ESCs) are crucial for maintenance and self- renewal of skin epithelium and also for regular hair cycling. Their role in wound healing is also indispensable. ESCs reside in a defined outer root sheath portion of hair follicle—also known as the bulge region. ECS are also found between basal cells of the interfollicular epidermis or mucous membranes. The non-epithelial elements such as mesenchymal stem cell-like elements of dermis or surrounding adipose tissue can also cont...

  17. Potential Therapies by Stem Cell-Derived Exosomes in CNS Diseases: Focusing on the Neurogenic Niche

    OpenAIRE

    Luarte, Alejandro; Bátiz, Luis Federico; Wyneken, Ursula; Lafourcade, Carlos

    2016-01-01

    Neurodegenerative disorders are one of the leading causes of death and disability and one of the biggest burdens on health care systems. Novel approaches using various types of stem cells have been proposed to treat common neurodegenerative disorders such as Alzheimer's Disease, Parkinson's Disease, or stroke. Moreover, as the secretome of these cells appears to be of greater benefit compared to the cells themselves, the extracellular components responsible for its therapeutic benefit have be...

  18. Potential Therapies by Stem Cell-Derived Exosomes in CNS Diseases: Focusing on the Neurogenic Niche

    OpenAIRE

    Luarte, Alejandro; Bátiz, Luis Federico; Wyneken, Ursula; Lafourcade, Carlos

    2016-01-01

    Neurodegenerative disorders are one of the leading causes of death and disability and one of the biggest burdens on health care systems. Novel approaches using various types of stem cells have been proposed to treat common neurodegenerative disorders such as Alzheimer’s Disease, Parkinson’s Disease, or stroke. Moreover, as the secretome of these cells appears to be of greater benefit compared to the cells themselves, the extracellular components responsible for its therapeutic benefit have be...

  19. Decidualization induces a secretome switch in perivascular niche cells of the human endometrium.

    Science.gov (United States)

    Murakami, Keisuke; Lee, Yie Hou; Lucas, Emma S; Chan, Yi-Wah; Durairaj, Ruban Peter; Takeda, Satoru; Moore, Jonathan D; Tan, Bee K; Quenby, Siobhan; Chan, Jerry K Y; Gargett, Caroline E; Brosens, Jan J

    2014-11-01

    The endometrial perivascular microenvironment is rich in mesenchymal stem-like cells that express type 1 integral membrane protein Sushi domain containing 2 (SUSD2) but the role of these cells in the decidual transformation of this tissue in pregnancy is unknown. We used an antibody directed against SUSD2 (W5C5) to isolate perivascular (W5C5(+)) and nonperivascular (W5C5(-)) fibroblasts from mid-luteal biopsies. We show that SUSD2 expression, and hence the ratio of W5C5(+):W5C5(-) cells, changes in culture depending on cell-cell contact and activation of the Notch signaling pathway. RNA sequencing revealed that cultures derived from W5C5(+) progenitor cells remain phenotypically distinct by the enrichment of novel and established endometrial perivascular signature genes. In an undifferentiated state, W5C5(+)-derived cells produced lower levels of various chemokines and inflammatory modulators when compared with their W5C5(-) counterparts. This divergence in secretomes was switched and became more pronounced upon decidualization, which transformed perivascular W5C5(+) cells into the dominant source of a range of chemokines and cytokines, including leukemia inhibitory factor and chemokine (C-C motif) ligand 7. Our findings suggest that the decidual response is spatially organized at the embryo-maternal interface with differentiating perivascular cells establishing distinct cytokine and chemokine profiles that could potentially direct trophoblast toward maternal vessels and govern local immune responses in pregnancy. PMID:25116707

  20. Regulation of microRNA expression in the neuronal stem cell niches during aging of the short-lived annual fish Nothobranchius furzeri.

    Directory of Open Access Journals (Sweden)

    Mario Baumgart

    2014-02-01

    Full Text Available In the last decade, our group has intensively studied the annual fish Nothobranchius furzeri as a new experimental model in Biology specifically applied to aging research. We previously studied adult neuronal stem cells of N. furzeri in vivo and we demonstrated an age-dependent decay in adult neurogenesis. More recently we identified and quantified the expression of miRNAs in the brain of N. furzeri and we detected 165 conserved miRNAs and found that brain aging in Nothobranchius furzeri is associated with coherent up-regulation of well-known tumor suppressor miRNAs, as well as down-regulation of well-known onco miRNAs - In the present work we we characterized the expression of miR-15a, miR-20a and microRNA cluster 17~92 in the principal neurogenetic niches of the brain of young and old subjects of Nothobranchius furzeri, by using in situ hybridization techniques, together with PCNA immuno-staining for a simultaneous visualization of the neuronal progenitors - We found that: 1 the expression of miR-15a is higher in the brain of old subjects and concentrates mainly in the principal neurogenetic niches of telencephalon and optic tectum, 2 the expression of miR-20a is higher in the brain of young subjects, but more widespread to the areas surrounding the neurogenic niches, 3 finally, the expression of the microRNA cluster 17~92 is higher in the brain of young subjects, concentrated mainly in the principal neurogenic niches of telencephalon and cerebellum, and with reduced intensity in the optic tectum. Taken together, our data show that these microRNAs, originally identified in whole-brain analysis, are specifically regulated in the stem cell niche during aging.

  1. A coculture model mimicking the intestinal mucosa reveals a regulatory role for myofibroblasts in immune-mediated barrier disruption.

    Science.gov (United States)

    Willemsen, L E M; Schreurs, C C H M; Kroes, H; Spillenaar Bilgen, E J; Van Deventer, S J H; Van Tol, E A F

    2002-10-01

    The pathogenesis of Crohn's disease involves a mucosal inflammatory response affecting the barrier function of the gut. Myofibroblasts directly underlining the intestinal epithelium may have a regulatory role in immune-mediated barrier disruption. A coculture system of T84 epithelial and CCD-18Co myofibroblasts was established in order to mimic the in situ spatial interactions between these cell types and to evaluate their role in barrier: integrity. Lamina propria mononuclear cells (LPMC) were introduced in co- and monocultures. Effects of immune cells on barrier integrity was determined by measuring resistance and permeability for macromolecules. Introduction of LPMC in both culture systems caused a time-dependent decrease in barrier integrity. This was found to be less pronounced in cocultures indicating a regulatory role for mesenchymal cells. The effects were also found to depend on the route of LPMC stimulation. Additional analyses suggested that the regulatory role of myofibroblasts in barrier integrity involves production of growth factors. PMID:12395905

  2. Suppression of autophagy by extracellular vesicles promotes myofibroblast differentiation in COPD pathogenesis

    Directory of Open Access Journals (Sweden)

    Yu Fujita

    2015-11-01

    Full Text Available Extracellular vesicles (EVs, such as exosomes and microvesicles, encapsulate proteins and microRNAs (miRNAs as new modulators of both intercellular crosstalk and disease pathogenesis. The composition of EVs is modified by various triggers to maintain physiological homeostasis. In response to cigarette smoke exposure, the lungs develop emphysema, myofibroblast accumulation and airway remodelling, which contribute to chronic obstructive pulmonary disease (COPD. However, the lung disease pathogenesis through modified EVs in stress physiology is not understood. Here, we investigated an EV-mediated intercellular communication mechanism between primary human bronchial epithelial cells (HBECs and lung fibroblasts (LFs and discovered that cigarette smoke extract (CSE-induced HBEC-derived EVs promote myofibroblast differentiation in LFs. Thorough evaluations of the modified EVs and COPD lung samples showed that cigarette smoke induced relative upregulation of cellular and EV miR-210 expression of bronchial epithelial cells. Using co-culture assays, we showed that HBEC-derived EV miR-210 promotes myofibroblast differentiation in LFs. Surprisingly, we found that miR-210 directly regulates autophagy processes via targeting ATG7, and expression levels of miR-210 are inversely correlated with ATG7 expression in LFs. Importantly, autophagy induction was significantly decreased in LFs from COPD patients, and silencing ATG7 in LFs led to myofibroblast differentiation. These findings demonstrate that CSE triggers the modification of EV components and identify bronchial epithelial cell-derived miR-210 as a paracrine autophagy mediator of myofibroblast differentiation that has potential as a therapeutic target for COPD. Our findings show that stressor exposure changes EV compositions as emerging factors, potentially controlling pathological disorders such as airway remodelling in COPD.

  3. Inflammatory Myofibroblastic Tumor: A Rarely Seen Submucosal Lesion of the Stomach

    OpenAIRE

    Deniz Arslan; Şeyda Gündüz; Deniz Tural; Mükremin Uysal; Ali Murat Tatlı; Cumhur İbrahim Başsorgun; Gülsüm Özlem Elpek; Hasan Şenol Coşkun; Hakan Şat Bozcuk; Burhan Savaş

    2013-01-01

    Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal benign tumor which is generally seen in children and in young adults. It is especially located in the lungs. In histopathological examination, neoplastic fusiform cells originating from a subtype of accessory immune system cells which are called fibroblastic reticulum cells are seen (Kouichi and Youichirou, 2008). Although IMT is histopathologically benign, imaging methods show its tendency for local recurrence and invasion. In m...

  4. Market survey of fuel cells in Mexico: Niche for low power portable systems

    Science.gov (United States)

    Ramírez-Salgado, Joel; Domínguez-Aguilar, Marco A.

    This work provides an overview of the potential market in Mexico for portable electronic devices to be potentially powered by direct methanol fuel cells. An extrapolation method based on data published in Mexico and abroad served to complete this market survey. A review of electronics consumption set the basis for the future forecast and technology assimilation. The potential market for fuel cells for mobile phones in Mexico will be around 5.5 billion USD by 2013, considering a cost of 41 USD per cell in a market of 135 million mobile phones. Likewise, the market for notebook computers, PDAs and other electronic devices will likely grow in the future, with a combined consumption of fuel cell technology equivalent to 1.6 billion USD by 2014.

  5. GABA's Control of Stem and Cancer Cell Proliferation in Adult Neural and Peripheral Niches

    OpenAIRE

    Young, Stephanie Z.; Bordey, Angélique

    2009-01-01

    Aside from traditional neurotransmission and regulation of secretion, γ-amino butyric acid (GABA) through GABAA receptors negatively regulates proliferation of pluripotent and neural stem cells in embryonic and adult tissue. There has also been evidence that GABAergic signaling and its control over proliferation is not only limited to the nervous system, but is widespread through peripheral organs containing adult stem cells. GABA has emerged as a tumor signaling molecule in the periphery tha...

  6. A primary inflammatory myofibroblastic tumor of the scapula in a child: imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Inarejos Clemente, Emilio J.; Riaza Martin, Lucia [University of Barcelona, Hospital Sant Joan de Deu, Barcelona (Spain); Esplugues de Llobregat, Barcelona (Spain); Vilanova, Joan C. [University of Girona, Clinica Girona, Hospital Sta. Caterina, Girona (Spain); Guirao-Marin, Sara [CETIR Clinica Girona-ERESA, Girona (Spain)

    2015-05-01

    Inflammatory myofibroblastic tumor (IMT) is an uncommon tumor characterized by inflammatory cell infiltration and differentiated myofibroblastic spindle cells. IMT was first described in the lung and retroperitoneum. Occurrence in bone has been well described in the maxilla and occasionally in the long bones in the adult population. We present a unique case of IMT arising primarily from the scapula in an 8-year-old patient, not described previously in the pediatric or adult literature. Imaging demonstrated an ill-defined and aggressive osteolytic lesion with cortical bone destruction associated with an important soft tissue component that extended into the adjacent muscles. Histologically, the tumor was composed of spindle and polygonal cells distributed in an inflammatory background with different proportions of plasma cells, lymphocytes, eosinophils and neutrophils. The absence of cellular atypia helped to differentiate this entity from malignant spindle cell tumors, and imaging could differentiate the tumor from the nontumoral inflammatory reaction. (orig.)

  7. A primary inflammatory myofibroblastic tumor of the scapula in a child: imaging findings

    International Nuclear Information System (INIS)

    Inflammatory myofibroblastic tumor (IMT) is an uncommon tumor characterized by inflammatory cell infiltration and differentiated myofibroblastic spindle cells. IMT was first described in the lung and retroperitoneum. Occurrence in bone has been well described in the maxilla and occasionally in the long bones in the adult population. We present a unique case of IMT arising primarily from the scapula in an 8-year-old patient, not described previously in the pediatric or adult literature. Imaging demonstrated an ill-defined and aggressive osteolytic lesion with cortical bone destruction associated with an important soft tissue component that extended into the adjacent muscles. Histologically, the tumor was composed of spindle and polygonal cells distributed in an inflammatory background with different proportions of plasma cells, lymphocytes, eosinophils and neutrophils. The absence of cellular atypia helped to differentiate this entity from malignant spindle cell tumors, and imaging could differentiate the tumor from the nontumoral inflammatory reaction. (orig.)

  8. The niche-derived glial cell line-derived neurotrophic factor (GDNF induces migration of mouse spermatogonial stem/progenitor cells.

    Directory of Open Access Journals (Sweden)

    Lisa Dovere

    Full Text Available In mammals, the biological activity of the stem/progenitor compartment sustains production of mature gametes through spermatogenesis. Spermatogonial stem cells and their progeny belong to the class of undifferentiated spermatogonia, a germ cell population found on the basal membrane of the seminiferous tubules. A large body of evidence has demonstrated that glial cell line-derived neurotrophic factor (GDNF, a Sertoli-derived factor, is essential for in vivo and in vitro stem cell self-renewal. However, the mechanisms underlying this activity are not completely understood. In this study, we show that GDNF induces dose-dependent directional migration of freshly selected undifferentiated spermatogonia, as well as germline stem cells in culture, using a Boyden chamber assay. GDNF-induced migration is dependent on the expression of the GDNF co-receptor GFRA1, as shown by migration assays performed on parental and GFRA1-transduced GC-1 spermatogonial cell lines. We found that the actin regulatory protein vasodilator-stimulated phosphoprotein (VASP is specifically expressed in undifferentiated spermatogonia. VASP belongs to the ENA/VASP family of proteins implicated in actin-dependent processes, such as fibroblast migration, axon guidance, and cell adhesion. In intact seminiferous tubules and germline stem cell cultures, GDNF treatment up-regulates VASP in a dose-dependent fashion. These data identify a novel role for the niche-derived factor GDNF, and they suggest that GDNF may impinge on the stem/progenitor compartment, affecting the actin cytoskeleton and cell migration.

  9. Evolving insights on metabolism, autophagy and epigenetics in liver myofibroblasts

    Directory of Open Access Journals (Sweden)

    Zeribe Chike Nwosu

    2016-06-01

    Full Text Available Liver myofibroblasts (MFB are crucial mediators of extracellular matrix (ECM deposition in liver fibrosis. They arise mainly from hepatic stellate cells (HSCs upon a process termed activation. To a lesser extent, and depending on the cause of liver damage, portal fibroblasts, mesothelial cells and fibrocytes may also contribute to the MFB population. Targeting MFB to reduce liver fibrosis is currently an area of intense research. Unfortunately, a clog in the wheel of antifibrotic therapies is the fact that although MFB are known to mediate scar formation, and participate in liver inflammatory response, many of their molecular portraits are currently unknown. In this review, we discuss recent understanding of MFB in health and diseases, focusing specifically on three evolving research fields: metabolism, autophagy and epigenetics. We have emphasized on therapeutic prospects where applicable and mentioned techniques for use in MFB studies. Subsequently, we highlighted uncharted territories in MFB research to help direct future efforts aimed at bridging gaps in current knowledge.

  10. The Legionella pneumophila replication vacuole: making a cosy niche inside host cells.

    Science.gov (United States)

    Isberg, Ralph R; O'Connor, Tamara J; Heidtman, Matthew

    2009-01-01

    The pathogenesis of Legionella pneumophila is derived from its growth within lung macrophages after aerosols are inhaled from contaminated water sources. Interest in this bacterium stems from its ability to manipulate host cell vesicular-trafficking pathways and establish a membrane-bound replication vacuole, making it a model for intravacuolar pathogens. Establishment of the replication compartment requires a specialized translocation system that transports a large cadre of protein substrates across the vacuolar membrane. These substrates regulate vesicle traffic and survival pathways in the host cell. This Review focuses on the strategies that L. pneumophila uses to establish intracellular growth and evaluates why this microorganism has accumulated an unprecedented number of translocated substrates that are targeted at host cells. PMID:19011659

  11. HOXB4 can enhance the differentiation of embryonic stem cells by modulating the hematopoietic niche

    DEFF Research Database (Denmark)

    Jackson, Melany; Axton, Richard A; Taylor, A Helen; Wilson, Julie A; Gordon-Keylock, Sabrina A M; Kokkaliaris, Konstantinos D; Brickman, Joshua M; Schulz, Herbert; Hummel, Oliver; Hubner, Norbert; Forrester, Lesley M

    2012-01-01

    Hematopoietic differentiation of embryonic stem cells (ESCs) in vitro has been used as a model to study early hematopoietic development, and it is well documented that hematopoietic differentiation can be enhanced by overexpression of HOXB4. HOXB4 is expressed in hematopoietic progenitor cells...... ESCs. To test our hypothesis, we developed a conditionally activated HOXB4 expression system using the mutant estrogen receptor (ER(T2)) and showed that a pulse of HOXB4 prior to HPC emergence in differentiating ESCs led to an increase in hematopoietic differentiation. Expression profiling revealed an...

  12. S100A4-neutralizing antibody suppresses spontaneous tumor progression, pre-metastatic niche formation and alters T-cell polarization balance

    DEFF Research Database (Denmark)

    Grum-Schwensen, Birgitte; Klingelhöfer, Jörg; Beck, Mette;

    2015-01-01

    the mode of action of 6B12, a S100A4 neutralizing antibody. METHODS: The therapeutic effect of the 6B12 antibody was evaluated in two different mouse models. First, in a model of spontaneous breast cancer we assessed the dynamics of tumor growth and metastasis. Second, in a model of metastatic niche...... the metastatic spread of tumor cells is the S100A4 protein. S100A4 is known as an inducer of inflammatory processes and has been shown to attract T-cells to the primary tumor and to the pre-metastatic niche. The present study aims to examine the immunomodulatory role of S100A4 in vivo and in vitro and assess...... formation we determined the expression of metastatic niche markers. The levels of cytokine expression were assessed using antibody as well as PCR arrays and the results confirmed by qRT-PCR and ELISA. T-cell phenotyping and in vitro differentiation analyses were performed by flow cytometry. RESULTS: We show...

  13. IL-1β stimulation of CCD-18co myofibroblasts enhances repair of epithelial monolayers through Wnt-5a.

    Science.gov (United States)

    Raymond, Meera; Marchbank, Tania; Moyer, Mary P; Playford, Raymond J; Sanderson, Ian R; Kruidenier, Laurens

    2012-12-01

    Subepithelial myofibroblasts are involved in the initiation and coordination of intestinal epithelial repair, but the molecular signaling pathways are largely unknown. The cellular adaptations that occur during repair range from dedifferentiation and migration to proliferation and redifferentiation, in a way that is strongly reminiscent of normal crypt-to-villus epithelial maturation. We therefore hypothesized that Wnt/β-catenin signaling may have a pivotal role in intestinal epithelial wound repair. We used the established scratch wound method in Caco-2 cells and in nontransformed NCM460 cells to monitor the effects of IL-1β-stimulated colonic myofibroblasts (CCD-18co) on intestinal epithelial repair, with immunoblotting and immunodepletion to examine the conditioned media. Conditioned media from IL-1β-stimulated, but not -untreated, myofibroblasts increased Caco-2 wound closure twofold over 24 h. IL-1β-stimulated myofibroblasts downregulated the differentiation marker sucrase-isomaltase in the Caco-2 cells, whereas the proliferation marker c-myc was upregulated. Array expression profiling identified Wnt-5a as the Wnt-related gene that was most upregulated (28-fold) by IL-1β stimulation of CCDs. Recombinant Wnt-5a enhanced proliferation of Caco-2 and NCM460 cells. In scratch assays, it increased migration of the leading edge in both cell lines. Wnt-5a immunodepletion of the IL-1β-CCD conditioned media abrogated the ability to enhance the repair. Wnt-5a often acts through a noncanonical signal transduction pathway. Further experiments supported this pathway in epithelial wound healing: IL-1β-CCD-mediated repair was not affected by the addition of the canonical Wnt antagonist Dickkopf-1. Furthermore, media from stimulated myofibroblasts (but not Wnt-5a-depleted media) increased c-jun in Caco-2 cell nuclear extracts. Myofibroblast-mediated noncanonical Wnt-5a signaling is therefore important in the dedifferentiation and migration stages of epithelial wound

  14. 脊髓神经干细胞Niche的研究进展%Research progress in spinal cord neural stem cell Niche

    Institute of Scientific and Technical Information of China (English)

    廖法学; 张辉; 尹宗生

    2012-01-01

    BACKGROUND: Spinal cord injury is a common orthopedic disease. A lot of work has been done to focus on neural stem cells for treating spinal cord injury. The effect of spinal cord neural stem cell Niche on neural stem cells has become a gradually increasing research area.OBJECTIVE: To summarize the related research progress in spinal cord neural stem cell Niche.METHODS: A computer-based online search of Pubmed (1980-01/2011-11) and CNKI (2003-01/2011-11) was performed for articles in English and Chinese respectively with the keywords "neural stem cells, niche/microenvironment, spinal cord". In addition, manual search was performed.RESULTS AND CONCLUSION: A total of 483 articles were obtained, and finally 31 articles were included. The Niche provides a relatively stable microenvironment for survival, self-renewal and differentiation of spinal cord neural stem cells. After spinal cord injury, the change of Niche plays an important impact on the fate of spinal cord neural stem cells. Understanding the research progress of spinal cord neural stem cell Niche would provide a theoretical basis for treatment of spinal cord injury using neural stem cells.%背景:脊髓损伤是临床上常见的骨科疾病,大量工作聚焦于神经干细胞治疗脊髓损伤的研究上,脊髓神经干细胞Niche对神经干细胞的作用成为了新的热点.目的:综述脊髓神经干细胞Niche的相关研究进展.方法:应用计算机检索PubMed 1980-01/2011-11期间的相关文章,检索词为"neural stem cells,niche/microenvironment,spinal cord",并限定文章语言种类为English.同时计算机检索中国期刊全文数据库2003-01/2011-11 期间的相关文章,检索词为"神经干细胞,微环境,脊髓损伤",并限定文章语言种类为中文.此外还手工查阅相关专著数部.结果与结论:共检索到文献483篇,最终纳入31 篇.脊髓神经干细胞Niche为脊髓神经干细胞生存、自我更新以及分化提供了相对稳定的微环境,脊髓

  15. Biological properties of spermatogonial stem cell niches%精原干细胞微环境的生物学特性

    Institute of Scientific and Technical Information of China (English)

    李玲玲; 刘洋; 金波

    2012-01-01

    成体干细胞的自我更新和分化与其微环境关系密切.精原干细胞(spermatogonial stem cells,SSCs)是体内自然状态下唯一能将遗传信息传至子代的成体干细胞.探讨SSCs更新和分化的调控机制有助于精子发生机理的阐明,并为探究其他成体干细胞增殖分化的调节机制提供依据.因此,SSCs系统为成体干细胞微环境研究提供了理想模型.资料表明,SSCs的更新和分化受其微环境的调控.基于本室的工作,参考最新文献,本文主要从SSCs微环境的基本特性、构成及其产生的各种调控因子等角度,评述了SSCs微环境的生物学特性及其与SSCs更新和分化间的关系,以期为本领域研究及其他成体干细胞相关研究提供借鉴.%The self-renewal and differentiation of adult stem cells are closely related to their niches. Naturally, spermatogonial stem cells (SSCs) are the only adult stem cells in the body, which can transfer genetic information into the offspring. An insight into the modulation of the self-renewal and differentiation of SSCs can help elucidate the mechanisms of spermatogenesis and investigate the proliferation and differentiation of other adult stem cells. Therefore, the SSC system provides an ideal model for researches on the adult stem cell niche. More and more evidence indicates that the self-renewal and differentiation of SSCs are regulated by their niches. Based on our previous work and other related findings recently reported, this article presents an overview on the biological properties of SSC niches and their relationship with the self-renewal and differentiation of SSCs, focusing on the basic properties and components of SSC niches and various regulatory factors they produce.

  16. Cytometry by time-of-flight shows combinatorial cytokine expression and virus-specific cell niches within a continuum of CD8+ T cell phenotypes.

    Science.gov (United States)

    Newell, Evan W; Sigal, Natalia; Bendall, Sean C; Nolan, Garry P; Davis, Mark M

    2012-01-27

    Cytotoxic CD8(+) T lymphocytes directly kill infected or aberrant cells and secrete proinflammatory cytokines. By using metal-labeled probes and mass spectrometric analysis (cytometry by time-of-flight, or CyTOF) of human CD8(+) T cells, we analyzed the expression of many more proteins than previously possible with fluorescent labels, including surface markers, cytokines, and antigen specificity with modified peptide-MHC tetramers. With 3-dimensional principal component analysis (3D-PCA) to display phenotypic diversity, we observed a relatively uniform pattern of variation in all subjects tested, highlighting the interrelatedness of previously described subsets and the continuous nature of CD8(+) T cell differentiation. These data also showed much greater complexity in the CD8(+) T cell compartment than previously appreciated, including a nearly combinatorial pattern of cytokine expression, with distinct niches occupied by virus-specific cells. This large degree of functional diversity even between cells with the same specificity gives CD8(+) T cells a remarkable degree of flexibility in responding to pathogens. PMID:22265676

  17. Rat alveolar myofibroblasts acquire alpha-smooth muscle actin expression during bleomycin-induced pulmonary fibrosis.

    OpenAIRE

    Vyalov, S. L.; Gabbiani, G.; Kapanci, Y.

    1993-01-01

    The majority of fibroblasts in alveolar septa are characterized by the presence of cytoplasmic bundles of microfilaments that contain cytoplasmic actin isoforms; these cells have been named contractile interstitial cells or V-type myofibroblasts. In the rat, they express desmin as intermediate filament protein. In this study, we explored the possibility that modulation and replication of such septal fibroblasts result in the appearance of alpha-smooth muscle (alpha-SM) actin-positive myofibro...

  18. Metabolic diversity and ecological niches of Achromatium populations revealed with single-cell genomic sequencing

    Directory of Open Access Journals (Sweden)

    Muammar eMansor

    2015-08-01

    Full Text Available Large, sulfur-cycling, calcite-precipitating bacteria in the genus Achromatium represent a significant proportion of bacterial communities near sediment-water interfaces throughout the world. Our understanding of their potentially crucial roles in calcium, carbon, sulfur, nitrogen, and iron cycling is limited because they have not been cultured or sequenced using environmental genomics approaches to date. We utilized single-cell genomic sequencing to obtain one incomplete and two nearly complete draft genomes for Achromatium collected at Warm Mineral Springs, FL. Based on 16S rRNA gene sequences, the three cells represent distinct and relatively distant Achromatium populations (91-92% identity. The draft genomes encode key genes involved in sulfur and hydrogen oxidation; oxygen, nitrogen and polysulfide respiration; carbon and nitrogen fixation; organic carbon assimilation and storage; chemotaxis; twitching motility; antibiotic resistance; and membrane transport. Known genes for iron and manganese energy metabolism were not detected. The presence of pyrophosphatase and vacuolar (V-type ATPases, which are generally rare in bacterial genomes, suggests a role for these enzymes in calcium transport, proton pumping, and/or energy generation in the membranes of calcite-containing inclusions.

  19. Cardiac Niche Influences the Direct Reprogramming of Canine Fibroblasts into Cardiomyocyte-Like Cells

    Directory of Open Access Journals (Sweden)

    Giacomo Palazzolo

    2016-01-01

    Full Text Available The Duchenne and Becker muscular dystrophies are caused by mutation of dystrophin gene and primarily affect skeletal and cardiac muscles. Cardiac involvement in dystrophic GRMD dogs has been demonstrated by electrocardiographic studies with the onset of a progressive cardiomyopathy similar to the cardiac disease in DMD patients. In this respect, GRMD is a useful model to explore cardiac and skeletal muscle pathogenesis and for developing new therapeutic protocols. Here we describe a protocol to convert GRMD canine fibroblasts isolated from heart and skin into induced cardiac-like myocytes (ciCLMs. We used a mix of transcription factors (GATA4, HAND2, TBX5, and MEF2C, known to be able to differentiate mouse and human somatic cells into ciCLMs. Exogenous gene expression was obtained using four lentiviral vectors carrying transcription factor genes and different resistance genes. Our data demonstrate a direct switch from fibroblast into ciCLMs with no activation of early cardiac genes. ciCLMs were unable to contract spontaneously, suggesting, differently from mouse and human cells, an incomplete differentiation process. However, when transplanted in neonatal hearts of SCID/Beige mice, ciCLMs participate in cardiac myogenesis.

  20. Intranasally administered mesenchymal stem cells promote a regenerative niche for repair of neonatal ischemic brain injury.

    Science.gov (United States)

    Donega, Vanessa; Nijboer, Cora H; van Tilborg, Geralda; Dijkhuizen, Rick M; Kavelaars, Annemieke; Heijnen, Cobi J

    2014-11-01

    Previous work from our group has shown that intranasal MSC-treatment decreases lesion volume and improves motor and cognitive behavior after hypoxic-ischemic (HI) brain damage in neonatal mice. Our aim was to determine the kinetics of MSC migration after intranasal administration, and the early effects of MSCs on neurogenic processes and gliosis at the lesion site. HI brain injury was induced in 9-day-old mice and MSCs were administered intranasally at 10days post-HI. The kinetics of MSC migration were investigated by immunofluorescence and MRI analysis. BDNF and NGF gene expression was determined by qPCR analysis following MSC co-culture with HI brain extract. Nestin, Doublecortin, NeuN, GFAP, Iba-1 and M1/M2 phenotypic expression was assessed over time. MRI and immunohistochemistry analyses showed that MSCs reach the lesion site already within 2h after intranasal administration. At 12h after administration the number of MSCs at the lesion site peaks and decreases significantly at 72h. The number of DCX(+) cells increased 1 to 3days after MSC administration in the SVZ. At the lesion, GFAP(+)/nestin(+) and DCX(+) expression increased 3 to 5days after MSC-treatment. The number of NeuN(+) cells increased within 5days, leading to a dramatic regeneration of the somatosensory cortex and hippocampus at 18days after intranasal MSC administration. Interestingly, MSCs expressed significantly more BDNF gene when exposed to HI brain extract in vitro. Furthermore, MSC-treatment resulted in the resolution of the glial scar surrounding the lesion, represented by a decrease in reactive astrocytes and microglia and polarization of microglia towards the M2 phenotype. In view of the current lack of therapeutic strategies, we propose that intranasal MSC administration is a powerful therapeutic option through its functional repair of the lesion represented by regeneration of the cortical and hippocampal structure and decrease of gliosis. PMID:24945601

  1. The molecular signature of the stroma response in prostate cancer-induced osteoblastic bone metastasis highlights expansion of hematopoietic and prostate epithelial stem cell niches.

    Science.gov (United States)

    Özdemir, Berna C; Hensel, Janine; Secondini, Chiara; Wetterwald, Antoinette; Schwaninger, Ruth; Fleischmann, Achim; Raffelsberger, Wolfgang; Poch, Olivier; Delorenzi, Mauro; Temanni, Ramzi; Mills, Ian G; van der Pluijm, Gabri; Thalmann, George N; Cecchini, Marco G

    2014-01-01

    The reciprocal interaction between cancer cells and the tissue-specific stroma is critical for primary and metastatic tumor growth progression. Prostate cancer cells colonize preferentially bone (osteotropism), where they alter the physiological balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption, and elicit prevalently an osteoblastic response (osteoinduction). The molecular cues provided by osteoblasts for the survival and growth of bone metastatic prostate cancer cells are largely unknown. We exploited the sufficient divergence between human and mouse RNA sequences together with redefinition of highly species-specific gene arrays by computer-aided and experimental exclusion of cross-hybridizing oligonucleotide probes. This strategy allowed the dissection of the stroma (mouse) from the cancer cell (human) transcriptome in bone metastasis xenograft models of human osteoinductive prostate cancer cells (VCaP and C4-2B). As a result, we generated the osteoblastic bone metastasis-associated stroma transcriptome (OB-BMST). Subtraction of genes shared by inflammation, wound healing and desmoplastic responses, and by the tissue type-independent stroma responses to a variety of non-osteotropic and osteotropic primary cancers generated a curated gene signature ("Core" OB-BMST) putatively representing the bone marrow/bone-specific stroma response to prostate cancer-induced, osteoblastic bone metastasis. The expression pattern of three representative Core OB-BMST genes (PTN, EPHA3 and FSCN1) seems to confirm the bone specificity of this response. A robust induction of genes involved in osteogenesis and angiogenesis dominates both the OB-BMST and Core OB-BMST. This translates in an amplification of hematopoietic and, remarkably, prostate epithelial stem cell niche components that may function as a self-reinforcing bone metastatic niche providing a growth support specific for osteoinductive prostate cancer cells. The induction of this

  2. Inflammatory myofibroblastic tumor of the lung in pregnancy mimicking carcinoid tumor

    Directory of Open Access Journals (Sweden)

    Venkata Nagarjuna Maturu

    2016-01-01

    Full Text Available Inflammatory myofibroblastic tumors (IMT are uncommon neoplasms of the lung in adults. They constitute less than 1% of all lung neoplasms and usually present as parenchymal masses. Diagnosis requires a high index of suspicion. They are characterized by spindle-shaped tumor cells (fibroblasts/myofibroblasts in a background of lymphoplasmacytic infiltrate. About 50% of the tumors harbor an ALK gene rearrangement. They have to be differentiated from inflammatory pseudotumors (IPT, which show increased number of IgG4 plasma cells on immunostaining and are negative for anaplastic lymphoma kinase (ALK protein. Herein, we present a case of a 28-year old female who presented with hemoptysis and was diagnosed with an IMT of lung in the first trimester of pregnancy. We have not only reviewed the occurrence of IMT during pregnancy but also discuss the management options for IMT during pregnancy.

  3. Comparative study of chronic kidney disease in dogs and cats: induction of myofibroblasts.

    Science.gov (United States)

    Yabuki, A; Mitani, S; Fujiki, M; Misumi, K; Endo, Y; Miyoshi, N; Yamato, O

    2010-04-01

    We investigated the kidneys of dogs and cats to clarify whether renal myofibroblasts induction is associated with the severity of chronic kidney disease (CKD). Immunohistochemical expression of myofibroblast markers, alpha-smooth muscle actin (SMA) and vimentin, were evaluated quantitatively. The degrees of glomerulosclerosis, glomerular hypertrophy, interstitial cell infiltration, and interstitial fibrosis were also evaluated quantitatively. The plasma creatinine (pCre) concentrations correlated with glomerulosclerosis, cell infiltration, and fibrosis in dogs, and only with fibrosis in cats. The alpha-SMA expression correlated with pCre, glomerulosclerosis, cell infiltration, and fibrosis in dogs, and with pCre and fibrosis in cats. Tubular vimentin expression correlated with fibrosis in cats, but not in dogs. Interstitial vimentin expression correlated with pCre, glomerulosclerosis, cell infiltration, and fibrosis in dogs, but only with pCre in cats. In conclusion, it was suggested that the severity of CKD in dogs and cats was mediated by different pathways associated with myofibroblasts expression. PMID:19822338

  4. Agressive inflammatory myofibroblastic tumor of the liver with underlying schistosomiasis:A case report

    Institute of Scientific and Technical Information of China (English)

    Vera; Lucia; Pannain; Juliana; Vial; Passos; Ariovaldo; da; Rocha; Filho; Cristiane; Villela-Nogueira; Adriana; Caroli-Bottino

    2010-01-01

    Inflammatory myofibroblastic tumor(IMT)occurs infrequently in the liver.It is controversial whether it represents a low grade mesenchymal neoplasm or a reactive inflammatory lesion.Local recurrence and metastasis are rare and some tumors are associated with infectious agents.We report on a case of a large and partially resected IMT with local recurrence and diaphragm and kidney infiltration detected on routine surveillance two years later.Histologically,the tumor showed spindle cells without atypia,mitosis ...

  5. Myofibroblast expression in airways and alveoli is affected by smoking and COPD

    OpenAIRE

    Karvonen, Henna M; Lehtonen, Siri T.; Harju, Terttu; Sormunen, Raija T.; Lappi-Blanco, Elisa; Mäkinen, Johanna M.; Laitakari, Kirsi; Johnson, Shirley; Kaarteenaho, Riitta L

    2013-01-01

    Background Chronic obstructive pulmonary disease (COPD) is characterized by structural changes in alveoli and airways. Our aim was to analyse the numbers of alpha-smooth muscle actin (α-SMA) positive cells, as a marker of myofibroblasts, in different lung compartments in non-smokers and smokers with normal lung function or COPD. Methods α-SMA, tenascin-C (Tn-C) and EDA-fibronectin in alveolar level and airways were assayed by immunohistochemistry and quantified by image analysis. Immunohistoc...

  6. Myofibroblasts in proliferative diabetic retinopathy can originate from infiltrating fibrocytes and through endothelial-to-mesenchymal transition (EndoMT).

    Science.gov (United States)

    Abu El-Asrar, Ahmed M; De Hertogh, Gert; van den Eynde, Kathleen; Alam, Kaiser; Van Raemdonck, Katrien; Opdenakker, Ghislain; Van Damme, Jo; Geboes, Karel; Struyf, Sofie

    2015-03-01

    Myofibroblasts expressing α-smooth muscle actin (α-SMA) are the key cellular mediator of fibrosis. Fibrovascular epiretinal membranes from patients with proliferative diabetic retinopathy (PDR) are characterized by the accumulation of a large number of myofibroblasts. We explored the hypothesis that proliferating endothelial cells via endothelial-to-mesenchymal transition (EndoMT) and/or bone marrow-derived circulating fibrocytes contribute to the myofibroblast population present in PDR epiretinal membranes. Epiretinal membranes from 14 patients with PDR were studied by immunohistochemistry. All membranes contained neovessels expressing the endothelial cell marker CD31. CD31(+) endothelial cells co-expressed the fibroblast/myofibroblast markers fibroblast-specific protein-1 (FSP-1) and α-SMA, indicative for the occurrence of endoMT. In the stroma, cells expressing FSP-1, α-SMA, the leukocyte common antigen CD45, and the myelomonocytic marker CD11b were detected. Double labeling showed co-localization of CD45 with FSP-1 and α-SMA and co-localization of CD11b with α-SMA and matrix metalloproteinase-9, demonstrating the presence of infiltrating fibrocytes. In addition, we investigated the phenotypic changes that take place in human retinal microvascular endothelial cells following exposure to transforming growth factor-β1 (TGF-β1), connective tissue growth factor (CTGF) and the proinflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Retinal microvascular endothelial cells changed morphology upon cytokine exposure, lost the expression of endothelial cell markers (endothelial nitric oxide synthase and vascular endothelial-cadherin) and started to express mesenchymal markers (calponin, snail, transgelin and FSP-1). These results suggest that endothelial cells as well as circulating fibrocytes may differentiate into myofibroblasts in the diabetic eye and contribute to pathologic fibrosis in PDR. PMID:25637870

  7. Research Progress of Spermatogonial Stem Cells Niche%精原干细胞niche的研究进展

    Institute of Scientific and Technical Information of China (English)

    李靳; 彭奔; 刘苗苗; 邓丽丽; 张长城

    2015-01-01

    精原干细胞(spermatogonial stem cells,SSCs)是指睾丸内位于曲精细管基膜上既能自我更新维持自身适量恒定,又能定向分化产生精母细胞的一类原始精原细胞.随着干细胞深入的研究,人们发现了一种控制着干细胞可塑性与命运的微环境,此微环境被称为干细胞niche,干细胞niche由niche细胞、细胞外基质、细胞因子等构成.精原干细胞niche是由黏附因子、生长因子、支持细胞、间质细胞以及小管周肌肉细胞组成.大量的研究表明支持细胞在睾丸中是主要的成体细胞,通过分泌可溶性的因子来影响精原干细胞niche的结构与功能,同时支持细胞还能够间接的影响其他的成体细胞.随着年龄的增长使得精原干细胞niche的功能下降.精原干细胞数量以及精原干细胞niche为我们研究组织特异性干细胞生物学以及保持再生组织平衡提供了很宝贵的线索,精原干细胞对于保持组织的自我更新具有很重要的作用,并且受到人们大量的关注,然而精原干细胞niche也起到很重要的作用,它为治疗一些疾病提供新途径.本文将综述精原干细胞niche及其变化对精原干细胞功能调节的相关研究进展.

  8. A highly enriched niche of precursor cells with neuronal and glial potential within the hair follicle dermal papilla of adult skin.

    Science.gov (United States)

    Hunt, David P J; Morris, Paul N; Sterling, Jane; Anderson, Jane A; Joannides, Alexis; Jahoda, Colin; Compston, Alastair; Chandran, Siddharthan

    2008-01-01

    Skin-derived precursor cells (SKPs) are multipotent neural crest-related stem cells that grow as self-renewing spheres and are capable of generating neurons and myelinating glial cells. SKPs are of clinical interest because they are accessible and potentially autologous. However, although spheres can be readily isolated from embryonic and neonatal skin, SKP frequency falls away sharply in adulthood, and primary sphere generation from adult human skin is more problematic. In addition, the culture-initiating cell population is undefined and heterogeneous, limiting experimental studies addressing important aspects of these cells such as the behavior of endogenous precursors in vivo and the molecular mechanisms of neural generation. Using a combined fate-mapping and microdissection approach, we identified and characterized a highly enriched niche of neural crest-derived sphere-forming cells within the dermal papilla of the hair follicle of adult skin. We demonstrated that the dermal papilla of the rodent vibrissal follicle is 1,000-fold enriched for sphere-forming neural crest-derived cells compared with whole facial skin. These "papillaspheres" share a phenotypic and developmental profile similar to that of SKPs, can be readily expanded in vitro, and are able to generate both neuronal and glial cells in response to appropriate cues. We demonstrate that papillaspheres can be efficiently generated and expanded from adult human facial skin by microdissection of a single hair follicle. This strategy of targeting a highly enriched niche of sphere-forming cells provides a novel and efficient method for generating neuronal and glial cells from an accessible adult somatic source that is both defined and minimally invasive. PMID:17901404

  9. Irradiation of the potential cancer stem cell niches in the adult brain improves progression-free survival of patients with malignant glioma

    International Nuclear Information System (INIS)

    Glioblastoma is the most common brain tumor in adults. The mechanisms leading to glioblastoma are not well understood but animal studies support that inactivation of tumor suppressor genes in neural stem cells (NSC) is required and sufficient to induce glial cancers. This suggests that the NSC niches in the brain may harbor cancer stem cells (CSCs), Thus providing novel therapy targets. We hypothesize that higher radiation doses to these NSC niches improve patient survival by eradicating CSCs. 55 adult patients with Grade 3 or Grade 4 glial cancer treated with radiotherapy at UCLA between February of 2003 and May of 2009 were included in this retrospective study. Using radiation planning software and patient radiological records, the SVZ and SGL were reconstructed for each of these patients and dosimetry data for these structures was calculated. Using Kaplan-Meier analysis we show that patients whose bilateral subventricular zone (SVZ) received greater than the median SVZ dose (= 43 Gy) had a significant improvement in progression-free survival if compared to patients who received less than the median dose (15.0 vs 7.2 months PFS; P = 0.028). Furthermore, a mean dose >43 Gy to the bilateral SVZ yielded a hazard ratio of 0.73 (P = 0.019). Importantly, similarly analyzing total prescription dose failed to illustrate a statistically significant impact. Our study leads us to hypothesize that in glioma targeted radiotherapy of the stem cell niches in the adult brain could yield significant benefits over radiotherapy of the primary tumor mass alone and that damage caused by smaller fractions of radiation maybe less efficiently detected by the DNA repair mechanisms in CSCs

  10. Primary Tumor-Secreted Lymphangiogenic Factors Induce Pre-Metastatic Lymphvascular Niche Formation at Sentinel Lymph Nodes in Oral Squamous Cell Carcinoma

    OpenAIRE

    Wakisaka, Naohiro; Hasegawa, Yasuhisa; Yoshimoto, Seiichi; Miura, Kouki; Shiotani, Akihiro; Yokoyama, Junkichi; Sugasawa, Masashi; Moriyama-Kita, Makiko; Endo, Kazuhira; Yoshizaki, Tomokazu

    2015-01-01

    Objectives The objectives of this study were to evaluate the formation of lymphvascular niches in lymph nodes of patients with oral squamous cell carcinoma (OSCC), and investigate the roles of lymphangiogenic and angiogenic factors, such as vascular endothelial growth factor (VEGF)-A, VEGF-C, and VEGF-D, expressed in the primary tumors. Materials and Methods Forty-four patients with previously untreated clinically late T2 or T3 OSCC of cN0 were evaluated for primary tumors and 166 sentinel ly...

  11. The endoderm specifies the mesodermal niche for the germline in Drosophila via Delta-Notch signaling

    OpenAIRE

    Okegbe, Tishina C.; DiNardo, Stephen

    2011-01-01

    Interactions between niche cells and stem cells are vital for proper control over stem cell self-renewal and differentiation. However, there are few tissues where the initial establishment of a niche has been studied. The Drosophila testis houses two stem cell populations, which each lie adjacent to somatic niche cells. Although these niche cells sustain spermatogenesis throughout life, it is not understood how their fate is established. Here, we show that Notch signaling is necessary to spec...

  12. Congenital peribronchial myofibroblastic tumor: Case report and review of literature

    OpenAIRE

    Jolanta Jedrzkiewicz; Eric Scaife; Bo Hong; Sarah South; Mouied Alashari

    2015-01-01

    Congenital peribronchial myofibroblastic tumor (CPMT) is a rare entity recognized in the WHO classification of pulmonary neoplasms. According to available literature, it is a benign tumor with a high mortality rate exceeding 50%. It is partially attributed to polyhydramnios, hydrops, prematurity, respiratory distress or adverse surgical outcomes due to intraoperative bleeding. Herein we present a case of congenital peribronchial myofibroblastic tumor in a premature male infant who was born at...

  13. Exosomes from bulk and stem cells from human prostate cancer have a differential microRNA content that contributes cooperatively over local and pre-metastatic niche

    Science.gov (United States)

    Sánchez, Catherine A.; Andahur, Eliana I.; Valenzuela, Rodrigo; Castellón, Enrique A.; Fullá, Juan A.; Ramos, Christian G.; Triviño, Juan C.

    2016-01-01

    The different prostate cancer (PCa) cell populations (bulk and cancer stem cells, CSCs) release exosomes that contain miRNAs that could modify the local or premetastatic niche. The analysis of the differential expression of miRNAs in exosomes allows evaluating the differential biological effect of both populations on the niche, and the identification of potential biomarkers and therapeutic targets. Five PCa primary cell cultures were established to originate bulk and CSCs cultures. From them, exosomes were purified by precipitation for miRNAs extraction to perform a comparative profile of miRNAs by next generation sequencing in an Illumina platform. 1839 miRNAs were identified in the exosomes. Of these 990 were known miRNAs, from which only 19 were significantly differentially expressed: 6 were overexpressed in CSCs and 13 in bulk cells exosomes. miR-100-5p and miR-21-5p were the most abundant miRNAs. Bioinformatics analysis indicated that differentially expressed miRNAs are highly related with PCa carcinogenesis, fibroblast proliferation, differentiation and migration, and angiogenesis. Besides, miRNAs from bulk cells affects osteoblast differentiation. Later, their effect was evaluated in normal prostate fibroblasts (WPMY-1) where transfection with miR-100-5p, miR-21-5p and miR-139-5p increased the expression of metalloproteinases (MMPs) -2, -9 and -13 and RANKL and fibroblast migration. The higher effect was achieved with miR21 transfection. As conclusion, miRNAs have a differential pattern between PCa bulk and CSCs exosomes that act collaboratively in PCa progression and metastasis. The most abundant miRNAs in PCa exosomes are interesting potential biomarkers and therapeutic targets. PMID:26675257

  14. Reduced myofibroblast differentiation on femtosecond laser treated 316LS stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Oberringer, Martin [Department of Trauma, Hand and Reconstructive Surgery, Saarland University, Homburg (Germany); Akman, Erhan [Laser Technologies Research and Application Center (LATARUM), Kocaeli University, Yenikoey/Kocaeli (Turkey); Lee, Juseok [CVD/Biosurfaces Division, INM - Leibniz Institute for New Materials, Saarbruecken (Germany); Metzger, Wolfgang [Department of Trauma, Hand and Reconstructive Surgery, Saarland University, Homburg (Germany); Akkan, Cagri Kaan [CVD/Biosurfaces Division, INM - Leibniz Institute for New Materials, Saarbruecken (Germany); Kacar, Elif [Laser Technologies Research and Application Center (LATARUM), Kocaeli University, Yenikoey/Kocaeli (Turkey); Demir, Arif [Laser Technologies Research and Application Center (LATARUM), Kocaeli University, Yenikoey/Kocaeli (Turkey); BEAM Ar-Ge Optic, Laser and Spectroscopy, KOU Technopark, Kocaeli, 41275 (Turkey); Abdul-Khaliq, Hashim [Clinic for Pediatric Cardiology, Saarland University Hospital, Homburg (Germany); Puetz, Norbert; Wennemuth, Gunther [Department of Anatomy and Cell Biology, Saarland University, Homburg (Germany); Pohlemann, Tim [Department of Trauma, Hand and Reconstructive Surgery, Saarland University, Homburg (Germany); Veith, Michael [CVD/Biosurfaces Division, INM - Leibniz Institute for New Materials, Saarbruecken (Germany); Aktas, Cenk, E-mail: cenk.aktas@inm-gmbh.de [CVD/Biosurfaces Division, INM - Leibniz Institute for New Materials, Saarbruecken (Germany)

    2013-03-01

    In-stent restenosis is a common complication after stent surgery which leads to a dangerous wall narrowing of a blood vessel. Laser assisted patterning is one of the effective methods to modify the stent surface to control cell-surface interactions which play a major role in the restenosis. In this current study, 316LS stainless steel substrates are structured by focusing a femtosecond laser beam down to a spot size of 50 {mu}m. By altering the laser induced spot density three distinct surfaces (low density (LD), medium density (MD) and high density (HD)) were prepared. While such surfaces are composed of primary microstructures, due to fast melting and re-solidification by ultra-short laser pulses, nanofeatures are also observed as secondary structures. Following a detailed surface characterization (chemical and physical properties of the surface), we used a well-established co-culture assay of human microvascular endothelial cells and human fibroblasts to check the cell compatibility of the prepared surfaces. The surfaces were analyzed in terms of cell adherence, proliferation, cell morphology and the differentiation of the fibroblast into the myofibroblast, which is a process indicating a general fibrotic shift within a certain tissue. It is observed that myofibroblast proliferation decreases significantly on laser treated samples in comparison to non-treated ones. On the other hand endothelial cell proliferation is not affected by the surface topography which is composed of micro- and nanostructures. Such surfaces may be used to modify stent surfaces for prevention or at least reduction of restenosis. - Highlights: Black-Right-Pointing-Pointer Reduced myofibroblast proliferation by micro- and nanotopography Black-Right-Pointing-Pointer Ultra-hydrophobic surfaces by femtosecond laser structuring Black-Right-Pointing-Pointer Micro- and nanostructuring of stainless steel surfaces by a femtosecond laser.

  15. Distinct miRNA profiles in normal and gastric cancer myofibroblasts and significance in Wnt signaling.

    Science.gov (United States)

    Wang, Liyi; Steele, Islay; Kumar, Jothi Dinesh; Dimaline, Rod; Jithesh, Puthen V; Tiszlavicz, Laszlo; Reisz, Zita; Dockray, Graham J; Varro, Andrea

    2016-05-01

    Stromal cells influence epithelial function in both health and disease. Myofibroblasts are abundant stromal cells that influence the cellular microenvironment by release of extracellular matrix (ECM) proteins, growth factors, proteases, cytokines, and chemokines. Cancer-associated myofibroblasts (CAMs) differ from adjacent tissue (ATMs) and normal tissue myofibroblasts (NTMs), but the basis of this is incompletely understood. We report now the differential expression of miRNAs in gastric cancer CAMs. MicroRNA arrays identified differences in the miRNA profile in gastric and esophageal NTMs and in CAMs from stomach compared with NTMs. miR-181d was upregulated in gastric CAMs. Analysis of differentially regulated miRNAs indicated an involvement in Wnt signaling. Examination of a microarray data set then identified Wnt5a as the only consistently upregulated Wnt ligand in gastric CAMs. Wnt5a stimulated miR-181d expression, and knockdown of miR-181d inhibited Wnt5a stimulation of CAM proliferation and migration. Analysis of miR-181d targets suggested a role in chemotaxis. Conditioned medium from CAMs stimulated gastric cancer cell (AGS) migration more than that from ATMs, and miR-181d knockdown reduced the effect of CAM-CM on AGS cell migration but had no effect on AGS cell responses to ATM conditioned media. The data suggest that dysregulation of miRNA expression in gastric CAMs, secondary to Wnt5a signaling, accounts at least in part for the effect of CAMs in promoting cancer cell migration. PMID:26939869

  16. Inflammatory Myofibroblastic Tumor Mimicking Apical Periodontitis.

    Science.gov (United States)

    Adachi, Makoto; Kiho, Kazuki; Sekine, Genta; Ohta, Takahisa; Matsubara, Makoto; Yoshida, Takakazu; Katsumata, Akitoshi; Tanuma, Jun-ichi; Sumitomo, Shinichiro

    2015-12-01

    Inflammatory myofibroblastic tumors (IMTs) are rare. IMTs of the head and neck occur in all age groups, from neonates to old age, with the highest incidence occurring in childhood and early adulthood. An IMT has been defined as a histologically distinctive lesion of uncertain behavior. This article describes an unusual case of IMT mimicking apical periodontitis in the mandible of a 42-year-old man. At first presentation, the patient showed spontaneous pain and percussion pain at teeth #28 to 30, which continued after initial endodontic treatment. Panoramic radiography revealed a radiolucent lesion at the site. Cone-beam computed tomographic imaging showed osteolytic lesions, suggesting an aggressive neoplasm requiring incisional biopsy. Histopathological examination indicated an IMT. The lesion was removed en bloc under general anesthesia, and the patient manifested no clinical evidence of recurrence for 24 months. Lesions of nonendodontic origin should be included in the differential diagnosis of apical periodontitis. Every available diagnostic tool should be used to confirm the diagnosis. Cone-beam computed tomographic imaging is very helpful for differential diagnosis in IMTs mimicking apical periodontitis. PMID:26602450

  17. Inflammatory Myofibroblastic Tumor of the Right Atrium

    Directory of Open Access Journals (Sweden)

    Neerod K. Jha

    2010-01-01

    Full Text Available Cardiac inflammatory myofibroblastic tumor (IMT is a rare entity and is associated with distinct clinical, pathological and molecular features. The clinical behavior, natural history, biological potential, management and prognosis of such tumors are unclear. We present herewith an adolescent girl who presented with similar entity involving the junction of the right atrium and the inferior vena cava (IVC in association with thrombocytosis and IVC thrombosis leading to obstruction of blood flow. Diagnostic tools included imaging and immuno-histopathology studies. Surgical management included resection of the tumor and thrombo-embolectomy of the IVC under cardiopulmonary bypass. This case is unique due to association of complete obstruction of IVC caused by the strategic location of the tumor, thrombosis of vena cava and association of thrombocytosis. These features have not been reported yet in relation to the cardiac IMT. This report will help in better understanding and management of similar cases in terms of planning cannulation of femoral veins or application of total hypothermic circulatory arrest during cardiopulmonary bypass and prompt us to look for recurrence or metastasis during follow up using echocardiography and laboratory investigations. The possibility of IMT should be kept in the differential diagnosis of cardiac tumors especially in children and adolescents.

  18. Lactic Acid is Elevated in Idiopathic Pulmonary Fibrosis and Induces Myofibroblast Differentiation Via pH-Dependent Activation of Transforming Growth Factor-β

    Energy Technology Data Exchange (ETDEWEB)

    Kottman, R. M.; Kulkarni, Ajit A.; Smolnycki, Katie A.; Lyda, Elizabeth; Dahanayake, Thinesh; Salibi, Rami; Honnons, Sylvie; Jones, Carolyn; Isern, Nancy G.; Hu, Jian Z.; Nathan, Steven D.; Grant, Geraldine; Phipps, Richard P.; Sime, Patricia J.

    2012-10-15

    Rationale: Idiopathic pulmonary fibrosis (IPF) is a complex disease for which the pathogenesis is poorly understood. In this study, we identified lactic acid as a metabolite that is elevated in the lung tissue of patients with IPF. Objectives: This study examines the effect of lactic acid on myofibroblast differentiation and pulmonary fibrosis. Methods:We used metabolomic analysis to examine cellular metabolism in lung tissuefrom patients with IPFanddeterminedthe effects of lactic acid and lactate dehydrogenase-5 (LDH5) overexpression on myofibroblast differentiation and transforming growth factor (TGF)-b activation in vitro. Measurements and Main Results: Lactic acid concentrations from healthy and IPF lung tissue were determined by nuclear magnetic resonance spectroscopy; a-smooth muscle actin, calponin, and LDH5 expression were assessed by Western blot of cell culture lysates. Lactic acid and LDH5 were significantly elevated in IPF lung tissue compared with controls. Physiologic concentrations of lactic acid induced myofibroblast differentiation via activation of TGF-b. TGF-b induced expression of LDH5 via hypoxia-inducible factor 1a (HIF1a). Importantly, overexpression of both HIF1a and LDH5 in human lung fibroblasts induced myofibroblast differentiation and synergized with low dose TGF-b to induce differentiation. Furthermore, inhibition of both HIF1a and LDH5 inhibited TGF-b–induced myofibroblast differentiation. Conclusions: We have identified the metabolite lactic acid as an important mediator of myofibroblast differentiation via a pHdependent activation of TGF-b. We propose that the metabolic milieu of the lung, and potentially other tissues, is an important driving force behind myofibroblast differentiation and potentially the initiation and progression of fibrotic disorders.

  19. Sulfur nutrient availability regulates root elongation by affecting root indole-3-acetic acid levels and the stem cell niche

    Institute of Scientific and Technical Information of China (English)

    Qing Zhao; Yu Wu; Lei Gao; Jun Ma; Chuan-You Li; Cheng-Bin Xiang

    2014-01-01

    Sulfur is an essential macronutrient for plants with numerous biological functions. However, the influence of sulfur nutrient availability on the regulation of root development remains largely unknown. Here, we report the response of Arabidopsis thaliana L. root development and growth to different levels of sulfate, demonstrating that low sulfate levels promote the primary root elongation. By using various reporter lines, we examined in vivo IAA level and distribution, cel division, and root meristem in response to different sulfate levels. Meanwhile the dynamic changes of in vivo cysteine, glutathione, and IAA levels were measured. Root cysteine, glutathione, and IAA levels are positively correlated with external sulfate levels in the physiological range, which eventual y affect root system architecture. Low sulfate levels also downregulate the genes involved in auxin biosynthesis and transport, and elevate the accumulation of PLT1 and PLT2. This study suggests that sulfate level affects the primary root elongation by regulating the endogenous auxin level and root stem cel niche maintenance.

  20. Reduced myofibroblast differentiation on femtosecond laser treated 316LS stainless steel

    International Nuclear Information System (INIS)

    In-stent restenosis is a common complication after stent surgery which leads to a dangerous wall narrowing of a blood vessel. Laser assisted patterning is one of the effective methods to modify the stent surface to control cell–surface interactions which play a major role in the restenosis. In this current study, 316LS stainless steel substrates are structured by focusing a femtosecond laser beam down to a spot size of 50 μm. By altering the laser induced spot density three distinct surfaces (low density (LD), medium density (MD) and high density (HD)) were prepared. While such surfaces are composed of primary microstructures, due to fast melting and re-solidification by ultra-short laser pulses, nanofeatures are also observed as secondary structures. Following a detailed surface characterization (chemical and physical properties of the surface), we used a well-established co-culture assay of human microvascular endothelial cells and human fibroblasts to check the cell compatibility of the prepared surfaces. The surfaces were analyzed in terms of cell adherence, proliferation, cell morphology and the differentiation of the fibroblast into the myofibroblast, which is a process indicating a general fibrotic shift within a certain tissue. It is observed that myofibroblast proliferation decreases significantly on laser treated samples in comparison to non-treated ones. On the other hand endothelial cell proliferation is not affected by the surface topography which is composed of micro- and nanostructures. Such surfaces may be used to modify stent surfaces for prevention or at least reduction of restenosis. - Highlights: ► Reduced myofibroblast proliferation by micro- and nanotopography ► Ultra-hydrophobic surfaces by femtosecond laser structuring ► Micro- and nanostructuring of stainless steel surfaces by a femtosecond laser.

  1. From blood to brain: the neurogenic niche of the crayfish brain.

    Science.gov (United States)

    Hartenstein, Volker

    2014-08-11

    Adult neurogenic niches are present in both vertebrates and invertebrates. Where do stem cells populating these niches originate, and what are the mechanisms maintaining their self-renewal? In this issue of Developmental Cell, Benton et al. (2014) show that in crayfish, hemolymph-derived cells enter a neurogenic niche to replenish neural progenitors. PMID:25117680

  2. Niche Applications of Irreversible Electroporation.

    Science.gov (United States)

    Bhatia, Shivank S; Arya, Rahul; Narayanan, Govindarajan

    2015-09-01

    Irreversible electroporation (IRE) induces cell death by exposing it to high-voltage, low-energy DC current pulses. The mechanism of cell death and healing is a departure from the other existing technologies such as radiofrequency ablation, microwave ablation, and cryoablation. These thermal ablative technologies have several applications in oncology but have limitations that have also been established. IRE has shown promise to overcome some of these limitations and has enabled the use of an ablative technology in treating lesions close to the bile ducts and vasculature and in organs such as the pancreas. This review highlights some of the niche applications of IRE and the data so far. PMID:26365547

  3. CARD-024, a vitamin D analog, attenuates the pro-fibrotic response to substrate stiffness in colonic myofibroblasts.

    Science.gov (United States)

    Johnson, Laura A; Sauder, Kay L; Rodansky, Eva S; Simpson, Robert U; Higgins, Peter D R

    2012-08-01

    Intestinal fibrosis is one of the major complications of Crohn's disease (CD) for which there are no effective pharmacological therapies. Vitamin D deficiency is common in CD, though it is not known whether this is a contributing factor to fibrosis, or simply a consequence of the disease itself. In CD, fibrosis is mediated mainly by activated intestinal myofibroblasts during remodeling of extracellular matrix in response to wound healing. We investigated the effects of CARD-024 (1-alpha-hydroxyvitamin D5), a vitamin D analog with minimal hypercalcemic effects, on the pro-fibrotic response of intestinal myofibroblasts to two fibrogenic stimuli: TGFβ stimulation and culture on a physiologically stiff matrix. TGFβ stimulated a fibrogenic phenotype in Ccd-18co colonic myofibroblasts, characterized by an increase in actin stress fibers and mature focal adhesions, and increased αSMA protein expression, while CARD-024 repressed αSMA protein expression in a dose-dependent manner. Culture of colonic myofibroblasts on physiological high stiffness substrates induced morphological changes with increased actin stress fibers and focal adhesion staining, induction of αSMA protein expression, FAK phosphorylation, induction of fibrogenic genes, and repression of COX-2 and IL-1β. CARD-024 treatment repressed the stiffness-induced morphological features including stellate cell morphology and the maturation of focal adhesions. CARD-024 repressed the stiffness-mediated induction of αSMA protein expression, FAK phosphorylation, and MLCK and ET-1 gene expression. In addition, CARD-024 partially stimulated members of the COX-2/IL-1β inflammatory pathway. In summary, CARD-024 attenuated the pro-fibrotic response of colonic myofibroblasts to high matrix stiffness, suggesting that vitamin D analogs such as CARD-024 may ameliorate intestinal fibrosis. PMID:22542712

  4. Special Morphological Features at the Interface of the Renal Stem/Progenitor Cell Niche Force to Reinvestigate Transport of Morphogens During Nephron Induction.

    Science.gov (United States)

    Minuth, Will W; Denk, Lucia

    2016-01-01

    Formation of a nephron depends on reciprocal signaling of different morphogens between epithelial and mesenchymal cells within the renal stem/progenitor cell niche. Previously, it has been surmised that a close proximity exists between both involved cell types and that morphogens are transported between them by diffusion. However, actual morphological data illustrate that mesenchymal and epithelial stem/progenitor cell bodies are separated by a striking interface. Special fixation of specimens by glutaraldehyde (GA) solution including cupromeronic blue, ruthenium red, or tannic acid for electron microscopy depicts that the interface is not void but filled in extended areas by textured extracellular matrix. Surprisingly, projections of mesenchymal cells cross the interface to contact epithelial cells. At those sites the plasma membranes of a mesenchymal and an epithelial cell are connected via tunneling nanotubes. Regarding detected morphological features in combination with involved morphogens, their transport cannot longer be explained solely by diffusion. Instead, it has to be sorted according to biophysical properties of morphogens and to detected environment. Thus, the new working hypothesis is that morphogens with good solubility such as glial cell line-derived neurotrophic factor (GDNF) or fibroblast growth factors (FGFs) are transported by diffusion. Morphogens with minor solubility such as bone morphogenetic proteins (BMPs) are secreted and stored for delivery on demand in illustrated extracellular matrix. In contrast, morphogens with poor solubility such as Wnts are transported in mesenchymal cell projections along the plasma membrane or via illustrated tunneling nanotubes. However, the presence of an intercellular route between mesenchymal and epithelial stem/progenitor cells by tunneling nanotubes also makes it possible that all morphogens are transported this way. PMID:26862472

  5. Myofibroblasts and colonic anastomosis healing in Wistar rats

    OpenAIRE

    Vasiliadou Kalliopi; Hytiroglou Prodromos; Apostolidis Stylianos; Basdanis George; Anthimidis Georgios; Efthimiadis Christoforos; Kosmidis Christophoros; Prousalidis John; Fahantidis Epameinondas

    2011-01-01

    Abstract Background The myofibroblasts play a central role in wound healing throughout the body. The process of wound healing in the colon was evaluated with emphasis on the role of myofibroblasts. Methods One hundred male Wistar rats weighing 274 ± 9.1 g (mean age: 3.5 months) were used. A left colonic segment was transected and the colon was re-anastomosed. Animals were randomly divided into two groups. The first group experimental animals (n = 50) were sacrificed on postoperative day 3, wh...

  6. The oncometabolite R-2-hydroxyglutarate activates NF-κB-dependent tumor-promoting stromal niche for acute myeloid leukemia cells.

    Science.gov (United States)

    Chen, Jing-Yi; Lai, You-Syuan; Tsai, Hui-Jen; Kuo, Cheng-Chin; Yen, B Linju; Yeh, Su-Peng; Sun, H Sunny; Hung, Wen-Chun

    2016-01-01

    Mutations of isocitrate dehydrogenase 1 (IDH1) and IDH2 in acute myeloid leukemia (AML) cells produce the oncometabolite R-2-hydroxyglutarate (R-2HG) to induce epigenetic alteration and block hematopoietic differentiation. However, the effect of R-2HG released by IDH-mutated AML cells on the bone marrow microenvironment is unclear. Here, we report that R-2HG induces IκB kinase-independent activation of NF-κB in bone marrow stromal cells. R-2HG acts via a reactive oxygen species/extracellular signal-regulated kinase (ERK)-dependent pathway to phosphorylate NF-κB on the Thr254 residue. This phosphorylation enhances the interaction of NF-κB and the peptidyl-prolyl cis-trans isomerase PIN1 and increases the protein stability and transcriptional activity of NF-κB. As a consequence, R-2HG enhances NF-κB-dependent expression of cytokines including IL-6, IL-8 and complement 5a to stimulate proliferation of AML cells. In addition, R-2HG also upregulates vascular endothelial adhesion molecule 1 and CXCR4 in stromal cells to enhance the contact between AML and stromal cells and attenuates chemotherapy-induced apoptosis. More importantly, we validated the R-2HG-activated gene signature in the primary bone marrow stromal cells isolated from IDH-mutated AML patients. Collectively, our results suggest that AML cell-derived R-2HG may be helpful for the establishment of a supportive bone marrow stromal niche to promote AML progression via paracrine stimulation. PMID:27577048

  7. A niche for neutrality.

    Science.gov (United States)

    Adler, Peter B; Hillerislambers, Janneke; Levine, Jonathan M

    2007-02-01

    Ecologists now recognize that controversy over the relative importance of niches and neutrality cannot be resolved by analyzing species abundance patterns. Here, we use classical coexistence theory to reframe the debate in terms of stabilizing mechanisms (niches) and fitness equivalence (neutrality). The neutral model is a special case where stabilizing mechanisms are absent and species have equivalent fitness. Instead of asking whether niches or neutral processes structure communities, we advocate determining the degree to which observed diversity reflects strong stabilizing mechanisms overcoming large fitness differences or weak stabilization operating on species of similar fitness. To answer this question, we propose combining data on per capita growth rates with models to: (i) quantify the strength of stabilizing processes; (ii) quantify fitness inequality and compare it with stabilization; and (iii) manipulate frequency dependence in growth to test the consequences of stabilization and fitness equivalence for coexistence. PMID:17257097

  8. ADP-ribosylation of actins in fibroblasts and myofibroblasts by botulinum C2 toxin: Influence on microfilament morphology and migratory behavior

    DEFF Research Database (Denmark)

    Rønnov-Jessen, Lone; Petersen, Ole William

    1996-01-01

    botulinum C2 toxin. The substrate for C2 toxin is globular actin, which upon ribosylation cannot incorporate into microfilaments. The pattern of actin ADP-ribosylation in (myo)fibroblasts in the presence of [32P]NAD was analyzed by isoelectric focusing, fluorography and immunoblotting. The influence of C2...... toxin on microfilaments in intact cells was further assessed by immunofluorescence, and motility was measured in a mass migration assay and by computerized video time-lapse microscopy. We show here that C2 toxin specifically ribosylates - and -actin in both fibroblasts and myofibroblasts. Whereas...

  9. Symplesiomorphies in the WUSCHEL clade suggest that the last common ancestor of seed plants contained at least four independent stem cell niches.

    Science.gov (United States)

    Nardmann, Judith; Werr, Wolfgang

    2013-09-01

    Evolutionary studies addressing plant architecture have uncovered several significant dichotomies between lower and higher land plant radiations, which are based on differences in meristem histology and function. Here, we assess the establishment of different stem cell niches during land plant evolution based on genes of the stem cell-promoting WUSCHEL (WUS) clade of the WOX (WUSCHEL-related homeobox) gene family. WOX gene orthology was addressed by phylogenetic analyses of full-length WOX protein sequences and cellular expression pattern studies indicate process homology. Gene amplifications in the WUS clade were present in the last common ancestor (LCA) of extant gymnosperms and angiosperms. Whereas the evolution of complex multicellular shoot and root meristems relates to members in the WUS/WOX5 sub-branch, the evolution of marginal and plate meristems or the vascular cambium is associated with gene duplications that gave rise to WOX3 and WOX4, respectively. A fourth WUS clade member, WOX2, was apparently recruited for apical cell fate specification during early embryogenesis. The evolution and functional interplay of WOX3 and WOX4 possibly promoted a novel mode of leaf development, and evolutionary adaptations in their activities have contributed to the great diversity in shape and architecture of leaves in seed plants. PMID:23721178

  10. Effects of 300 mT static magnetic field on IL-6 secretion in normal human colon myofibroblasts.

    Science.gov (United States)

    Gruchlik, Arkadiusz; Wilczok, Adam; Chodurek, Ewa; Polechoński, Władysław; Wolny, Daniel; Dzierzewicz, Zofia

    2012-01-01

    Intestinal subepithelial myofibroblasts play crucial role in the growth and development of the intestine. Colitis, small bowel injury, gastric ulcer disease and inflammatory bowel disease (IBD) accompany the increase of number of activated myofibroblasts. In the last few years, the increasing production of electromagnetic (EMF) and static magnetic fields (SMF), due to the expanding use of electronic devices in everyday life, has led to a number of studies on the effects of these fields on living organisms. EMF therapy, because of its anti-inflammatory properties, may be used in medicine in IBD treatment. This mechanism has not been elucidated yet. In the present work normal human colon myofibroblasts CCD-18Co were exposed to SMF with a flux density of 300 mT. After 24 h incubation TNF-alpha-dependent IL-6 secretion was determined with ELISA kit (RandD Systems).The influence of magnetic field and its effect on cell proliferation were determined with TOX-2 (In Vitro Toxicology Assay Kit XTT Based, TOX-2, Sigma) and CyQUANT NF cell proliferation assay kit (Molecular Probes). It was shown that SMF inhibited TNF-alpha-dependent IL-6 secretion. The observed effects were statistically significant and depended on the time of incubation. Moreover, SMF triggered cell proliferation whereas it did not alter cell viability. IL-6 belongs to pro-inflammatory cytokines family and plays a crucial role in IBD. Inhibition of IL-6 secretion by SMF and lack of its cytotoxic effect seem to be advantageous whilst SMF is implicated in the treatment of inflammatory diseases associated by increase in number of activated myofibroblasts. PMID:23285697

  11. The prostate cancer bone marrow niche: more than just ‘fertile soil'

    OpenAIRE

    Pedersen, Elisabeth A; Shiozawa, Yusuke; Kenneth J. Pienta; Taichman, Russell S.

    2012-01-01

    The hematopoietic stem cell (HSC) niche in the bone marrow has been studied extensively over the past few decades, yet the bone marrow microenvironment that supports the growth of metastatic prostate cancer (PCa) has only been recently considered to be a specialized ‘niche' as well. New evidence supports the fact that disseminated tumor cells (DTCs) of PCa actually target the HSC niche, displace the occupant HSCs and take up residence in the pre-existing niche space. This review describes som...

  12. Diagnosing and Treating Inflammatory Myofibroblastic Tumor of the Bladder

    Directory of Open Access Journals (Sweden)

    Ridwan Alam

    2016-01-01

    Full Text Available Inflammatory myofibroblastic tumor (IMT is an uncommon condition that is rarely encountered in the urinary tract. In this report, we present a case of IMT of the bladder in a woman with multiple previous pelvic surgeries. We further review the relevant literature to highlight this rare but important clinical presentation.

  13. Vascular dysfunction by myofibroblast activation in patients with idiopathic pulmonary fibrosis and prognostic significance

    Directory of Open Access Journals (Sweden)

    E.R. Parra

    2012-07-01

    Full Text Available In this study, we demonstrated the importance of telomerase protein expression and determined the relationships among telomerase, endothelin-1 (ET-1 and myofibroblasts during early and late remodeling of parenchymal and vascular areas in usual interstitial pneumonia (UIP using 27 surgical lung biopsies from patients with idiopathic pulmonary fibrosis (IPF. Telomerase+, myofibroblasts α-SMA+, smooth muscle cells caldesmon+, endothelium ET-1+ cellularity, and fibrosis severity were evaluated in 30 fields covering normal lung parenchyma, minimal fibrosis (fibroblastic foci, severe (mural fibrosis, and vascular areas of UIP by the point-counting technique and a semiquantitative score. The impact of these markers was determined in pulmonary functional tests and follow-up until death from IPF. Telomerase and ET-1 expression was significantly increased in normal and vascular areas compared to areas of fibroblast foci. Telomerase and ET-1 expression was inversely correlated with minimal fibrosis in areas of fibroblast foci and directly associated with severe fibrosis in vascular areas. Telomerase activity in minimal fibrosis areas was directly associated with diffusing capacity of the lung for oxygen/alveolar volume and ET-1 expression and indirectly associated with diffusing capacity of the lungs for carbon monoxide and severe fibrosis in vascular areas. Cox proportional hazards regression revealed a low risk of death for females with minimal fibrosis displaying high telomerase and ET-1 expression in normal areas. Vascular dysfunction by telomerase/ET-1 expression was found earlier than vascular remodeling by myofibroblast activation in UIP with impact on IPF evolution, suggesting that strategies aimed at preventing the effect of these mediators may have a greater impact on patient outcome.

  14. NTPDase2 and Purinergic Signaling Control Progenitor Cell Proliferation in Neurogenic Niches of the Adult Mouse Brain

    OpenAIRE

    Gampe, Kristine; Stefani, Jennifer; Hammer, Klaus; Brendel, Peter; Pötzsch, Alexandra; Enikolopov, Grigori; Enjyoji, Keiichi; Acker-Palmer, Amparo; Robson, Simon C.; Zimmermann, Herbert

    2015-01-01

    Nerve cells are continuously generated from stem cells in the adult mammalian subventricular zone (SVZ) and hippocampal dentate gyrus. We have previously noted that stem/progenitor cells in the SVZ and the subgranular layer (SGL) of the dentate gyrus express high levels of plasma membrane-bound nucleoside triphosphate diphosphohydrolase 2 (NTPDase2), an ectoenzyme that hydrolyzes extracellular nucleoside di- and triphosphates. We inferred that deletion of NTPDase2 would increase local extrace...

  15. The nonsense-mediated RNA decay pathway is disrupted in inflammatory myofibroblastic tumors.

    Science.gov (United States)

    Lu, JingWei; Plank, Terra-Dawn; Su, Fang; Shi, XiuJuan; Liu, Chen; Ji, Yuan; Li, ShuaiJun; Huynh, Andrew; Shi, Chao; Zhu, Bo; Yang, Guang; Wu, YanMing; Wilkinson, Miles F; Lu, YanJun

    2016-08-01

    Inflammatory myofibroblastic tumors (IMTs) are characterized by myofibroblast proliferation and an inflammatory cell infiltrate. Little is known about the molecular pathways that precipitate IMT formation. Here, we report the identification of somatic mutations in UPF1, a gene that encodes an essential component of the nonsense-mediated RNA decay (NMD) pathway, in 13 of 15 pulmonary IMT samples. The majority of mutations occurred in a specific region of UPF1 and triggered UPF1 alternative splicing. Several mRNA targets of the NMD pathway were upregulated in IMT samples, indicating that the UPF1 mutations led to reduced NMD magnitude. These upregulated NMD targets included NIK mRNA, which encodes a potent activator of NF-κB. In human lung cells, UPF1 depletion increased expression of chemokine-encoding genes in a NIK-dependent manner. Elevated chemokines and IgE class switching events were observed in IMT samples, consistent with NIK upregulation in these tumors. Together, these results support a model in which UPF1 mutations downregulate NMD, leading to NIK-dependent NF-κB induction, which contributes to the immune infiltration that is characteristic of IMTs. The molecular link between the NMD pathway and IMTs has implications for the diagnosis and treatment of these tumors. PMID:27348585

  16. An Unusual Case of Systemic Inflammatory Myofibroblastic Tumor with Successful Treatment with ALK-Inhibitor

    Directory of Open Access Journals (Sweden)

    Sanjivini V. Jacob

    2014-01-01

    Full Text Available Systemic inflammatory myofibroblastic tumor is an exceedingly rare entity. A 45-year-old Hispanic female presented with a 6-month history of left-sided thigh pain, low back pain, and generalized weakness. PET/CT scan revealed abnormal activity in the liver, adrenal gland, and pancreas. MRI of the abdomen demonstrated two 6-7 cm masses in the liver. MRI of the lumbar spine demonstrated lesions in the L2 to L4 spinous processes, paraspinal muscles, and subcutaneous tissues, as well as an 8 mm enhancing intradural lesion at T11, all thought to be metastatic disease. A biopsy of the liver showed portal tract expansion by a spindle cell proliferation rich in inflammation. Tumor cells showed immunoreactivity for smooth muscle actin and anaplastic lymphoma kinase 1 (ALK1. Tissue from the L5 vertebra showed a process histologically identical to that seen in the liver. FISH analysis of these lesions demonstrated an ALK (2p23 gene rearrangement. The patient was successfully treated with an ALK-inhibitor, Crizotinib, and is now in complete remission. We present the first reported case, to our knowledge, of inflammatory myofibroblastic tumor with systemic manifestations and ALK translocation. This case is a prime example of how personalized medicine has vastly improved patient care through the use of molecular-targeted therapy.

  17. Physical, Spatial, and Molecular Aspects of Extracellular Matrix of In Vivo Niches and Artificial Scaffolds Relevant to Stem Cells Research.

    Science.gov (United States)

    Akhmanova, Maria; Osidak, Egor; Domogatsky, Sergey; Rodin, Sergey; Domogatskaya, Anna

    2015-01-01

    Extracellular matrix can influence stem cell choices, such as self-renewal, quiescence, migration, proliferation, phenotype maintenance, differentiation, or apoptosis. Three aspects of extracellular matrix were extensively studied during the last decade: physical properties, spatial presentation of adhesive epitopes, and molecular complexity. Over 15 different parameters have been shown to influence stem cell choices. Physical aspects include stiffness (or elasticity), viscoelasticity, pore size, porosity, amplitude and frequency of static and dynamic deformations applied to the matrix. Spatial aspects include scaffold dimensionality (2D or 3D) and thickness; cell polarity; area, shape, and microscale topography of cell adhesion surface; epitope concentration, epitope clustering characteristics (number of epitopes per cluster, spacing between epitopes within cluster, spacing between separate clusters, cluster patterns, and level of disorder in epitope arrangement), and nanotopography. Biochemical characteristics of natural extracellular matrix molecules regard diversity and structural complexity of matrix molecules, affinity and specificity of epitope interaction with cell receptors, role of non-affinity domains, complexity of supramolecular organization, and co-signaling by growth factors or matrix epitopes. Synergy between several matrix aspects enables stem cells to retain their function in vivo and may be a key to generation of long-term, robust, and effective in vitro stem cell culture systems. PMID:26351461

  18. Physical, Spatial, and Molecular Aspects of Extracellular Matrix of In Vivo Niches and Artificial Scaffolds Relevant to Stem Cells Research

    Directory of Open Access Journals (Sweden)

    Maria Akhmanova

    2015-01-01

    Full Text Available Extracellular matrix can influence stem cell choices, such as self-renewal, quiescence, migration, proliferation, phenotype maintenance, differentiation, or apoptosis. Three aspects of extracellular matrix were extensively studied during the last decade: physical properties, spatial presentation of adhesive epitopes, and molecular complexity. Over 15 different parameters have been shown to influence stem cell choices. Physical aspects include stiffness (or elasticity, viscoelasticity, pore size, porosity, amplitude and frequency of static and dynamic deformations applied to the matrix. Spatial aspects include scaffold dimensionality (2D or 3D and thickness; cell polarity; area, shape, and microscale topography of cell adhesion surface; epitope concentration, epitope clustering characteristics (number of epitopes per cluster, spacing between epitopes within cluster, spacing between separate clusters, cluster patterns, and level of disorder in epitope arrangement, and nanotopography. Biochemical characteristics of natural extracellular matrix molecules regard diversity and structural complexity of matrix molecules, affinity and specificity of epitope interaction with cell receptors, role of non-affinity domains, complexity of supramolecular organization, and co-signaling by growth factors or matrix epitopes. Synergy between several matrix aspects enables stem cells to retain their function in vivo and may be a key to generation of long-term, robust, and effective in vitro stem cell culture systems.

  19. The PD-1 Axis Enforces an Anatomical Segregation of CTL Activity that Creates Tumor Niches after Allogeneic Hematopoietic Stem Cell Transplantation.

    Science.gov (United States)

    Michonneau, David; Sagoo, Pervinder; Breart, Béatrice; Garcia, Zacarias; Celli, Susanna; Bousso, Philippe

    2016-01-19

    Allogeneic hematopoietic stem cell transplantation (allo-HSCT), a curative treatment for hematologic malignancies, relies on donor cytotoxic T lymphocyte (CTL)-mediated graft-versus-leukemia (GVL) effect. Major complications of HSCT are graft-versus-host disease (GVHD) that targets specific tissues and tumor relapses. However, the mechanisms dictating the anatomical features of GVHD and GVL remain unclear. Here, we show that after HSCT, CTLs exhibited different killing activity in distinct tissues, being highest in the liver and lowest in lymph nodes. Differences were imposed by the microenvironment, partly through differential PD-1 ligand expression, which was strongly elevated in lymph nodes. Two-photon imaging revealed that PD-1 blockade restored CTL sensitivity to antigen and killing in lymph nodes. Weak CTL activity in lymph nodes promoted local tumor escape but could be reversed by anti-PD-1 treatment. Our results uncover a mechanism generating an anatomical segregation of CTL activity that might dictate sites of GVHD and create niches for tumor escape. PMID:26795248

  20. The Long Non-coding RNA HIF1A-AS2 Facilitates the Maintenance of Mesenchymal Glioblastoma Stem-like Cells in Hypoxic Niches

    Directory of Open Access Journals (Sweden)

    Marco Mineo

    2016-06-01

    Full Text Available Long non-coding RNAs (lncRNAs have an undefined role in the pathobiology of glioblastoma multiforme (GBM. These tumors are genetically and phenotypically heterogeneous with transcriptome subtype-specific GBM stem-like cells (GSCs that adapt to the brain tumor microenvironment, including hypoxic niches. We identified hypoxia-inducible factor 1 alpha-antisense RNA 2 (HIF1A-AS2 as a subtype-specific hypoxia-inducible lncRNA, upregulated in mesenchymal GSCs. Its deregulation affects GSC growth, self-renewal, and hypoxia-dependent molecular reprogramming. Among the HIF1A-AS2 interactome, IGF2BP2 and DHX9 were identified as direct partners. This association was needed for maintenance of expression of their target gene, HMGA1. Downregulation of HIF1A-AS2 led to delayed growth of mesenchymal GSC tumors, survival benefits, and impaired expression of HMGA1 in vivo. Our data demonstrate that HIF1A-AS2 contributes to GSCs’ speciation and adaptation to hypoxia within the tumor microenvironment, acting directly through its interactome and targets and indirectly by modulating responses to hypoxic stress depending on the subtype-specific genetic context.

  1. Niching as a Macrostructural Procedure*

    Directory of Open Access Journals (Sweden)

    Rufus H. Gouws

    2011-10-01

    Full Text Available

    Abstract: Niching is a macrostructural procedure of textual condensation which results in different dictionary articles being clustered into one textblock as subarticles headed by sublemmata. This article offers an identification and critical discussion of different types of niching. Examples from dictionaries are used to examine problems which dictionary users experience as a result of the application of niching. The emphasis is on problems regarding the search route of users via the outer access structure of dictionaries. A distinction is made between single niching and multiple niching. Different aspects of multiple niching receive attention, e.g. the use of remote and exclusively remote multiple niching. The focus is also on an increased degree of textual condensation resulting from these procedures as well as problems in the domain of the access structure. Attention is drawn to the influence of the inclusion of homonym pairs on the application of multiple niching. Problems arising from an inconsistent application of multiple niching are identified and solutions are suggested for these problems in order to enhance the quality of the lexicographic practice. It is shown that a user-driven dictionary would rather opt for the application of procedures of single niching and first level nesting instead of multiple niching.

    Keywords: EXCLUSIVELY REMOTE MULTIPLE NICHING, FIRST LEVEL NESTING, HETEROGENEOUS NICHING, HOMOGENEOUS NICHING, HYBRID NICHING, MULTIPLE NICHING, NESTING, NICHING, PARTIAL ARTICLE STRETCH, REMOTE NICHING, SINGLE NICHING, TEXTUAL CONDENSATION

    Opsomming: Nisting as 'n makrostrukturele prosedure. Nisting is 'n makrostrukturele teksverdigtingsprosedure waardeur woordeboekartikels in een teksblok as subartikels met sublemmata gegroepeer word. Hierdie artikel bevat 'n beskrywing en kritiese bespreking van verskillende tipes nisting. Aan die hand van woordeboekvoorbeelde word probleme wat gebruikers met die toepassing

  2. Transforming Growth Factor-β1 Induces Transdifferentiation of Fibroblasts into Myofibroblasts in Hypoxic Pulmonary Vascular Remodeling

    Institute of Scientific and Technical Information of China (English)

    Yong-Liang JIANG; Ai-Guo DAI; Qi-Fang LI; Rui-Cheng HU

    2006-01-01

    The muscularization of non-muscular pulmonary arterioles is animportant pathological feature of hypoxic pulmonary vascular remodeling. However, the origin of the cells involved in this process is still not well understood. The present study was undertaken to test the hypothesis that transforming growth factor-β 1 (TGF-β 1) can induce transdifferentiation of fibroblasts into myofibroblasts, which might play a key role in the muscularization of non-muscular pulmonary arterioles. It was found that mean pulmonary arterial pressure increased significantly after 7 d of hypoxia. Pulmonary artery remodeling index and right ventricular hypertrophy became evident after 14 d of hypoxia. The distribution of nonmuscular, partially muscular, and muscular vessels was significantly different after 7 d of hypoxia. Immunocytochemistry results demonstrated that the expression of α-smooth muscle actin was increased in intra-acinar pulmonary arteries with increasing hypoxic time. TGF-β1 mRNA expression in pulmonary arterial walls was increased significantly after 14 d of hypoxia, but showed no obvious changes after 3 or 7 d of hypoxia. In pulmonary tunica adventitia and tunica media, TGF-β1 protein staining was poorly positive in control rats, but was markedly enhanced after 3 d of hypoxia, reaching its peak after 7 d of hypoxia. The myofibroblast phenotype was confirmed by electron microscopy, which revealed microfilaments and a well-developed rough endoplasmic reticulum. Taken together, our results suggested that TGF-β1 induces transdifferentiation of fibroblasts into myofibroblasts, which is important in hypoxic pulmonary vascular remodeling.

  3. Inflammatory Myofibroblastic Tumor: A Rarely Seen Submucosal Lesion of the Stomach

    Directory of Open Access Journals (Sweden)

    Deniz Arslan

    2013-01-01

    Full Text Available Inflammatory myofibroblastic tumor (IMT is a rare mesenchymal benign tumor which is generally seen in children and in young adults. It is especially located in the lungs. In histopathological examination, neoplastic fusiform cells originating from a subtype of accessory immune system cells which are called fibroblastic reticulum cells are seen (Kouichi and Youichirou, 2008. Although IMT is histopathologically benign, imaging methods show its tendency for local recurrence and invasion. In most of the cases, it may not be possible to make a distinction whether it is malign or benign. Complete surgical resection is the most important treatment method. In this study, we have discussed the findings of our case having a gastric submucosal located IMT in light of the current literatures.

  4. Inflammatory Myofibroblastic Tumor: A Rarely Seen Submucosal Lesion of the Stomach

    Science.gov (United States)

    Arslan, Deniz; Gündüz, Şeyda; Tural, Deniz; Uysal, Mükremin; Tatlı, Ali Murat; Başsorgun, Cumhur İbrahim; Elpek, Gülsüm Özlem; Coşkun, Hasan Şenol; Bozcuk, Hakan Şat; Savaş, Burhan

    2013-01-01

    Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal benign tumor which is generally seen in children and in young adults. It is especially located in the lungs. In histopathological examination, neoplastic fusiform cells originating from a subtype of accessory immune system cells which are called fibroblastic reticulum cells are seen (Kouichi and Youichirou, 2008). Although IMT is histopathologically benign, imaging methods show its tendency for local recurrence and invasion. In most of the cases, it may not be possible to make a distinction whether it is malign or benign. Complete surgical resection is the most important treatment method. In this study, we have discussed the findings of our case having a gastric submucosal located IMT in light of the current literatures. PMID:23573435

  5. Adipose-derived stem cells from lean and obese humans show depot specific differences in their stem cell markers, exosome contents and senescence: role of protein kinase C delta (PKCδ) in adipose stem cell niche

    Science.gov (United States)

    Patel, Rekha S.; Carter, Gay; El Bassit, Ghattas; Patel, Achintya A.; Cooper, Denise R.; Murr, Michel

    2016-01-01

    Background Adipose-derived stem cells (ASC) and its exosomes are gaining utmost importance in the field of regenerative medicine. The ASCs tested for their potential in wound healing are predominantly derived from the subcutaneous depot of lean donors. However, it is important to characterize the ASC derived from different adipose depots as these depots have clinically distinct roles. Methods We characterized the ASC derived from subcutaneous and omental depots from a lean donor (sc-ASCn and om-ASCn) and compared it to the ASC derived from an obese donor (sc-ASCo and om-ASCo) using flow cytometry and real time qPCR. Results We show that stem cell markers Oct4, Sal4, Sox15, KLF4 and BMI1 have distinct expression patterns in each ASC. We evaluated the secretome of the ASC and characterized their secreted exosomes. We show long noncoding RNAs (lncRNAs) are secreted by ASC and their expression varied between the ASC’s derived from different depots. Protein kinase C delta (PKCδ) regulates the mitogenic signals in stem cells. We evaluated the effect of silencing PKCδ in sc-ASCn, om-ASCn, sc-ASCo and om-ASCo. Using β-galactosidase staining, we evaluated the percentage of senescent cells in sc-ASCn, om-ASCn, sc-ASCo and om-ASCo. Our results also indicated that silencing PKCδ increases the percentage of senescent cells. Conclusions Our case-specific study demonstrates a role of PKCδ in maintaining the adipose stem cell niche and importantly demonstrates depot-specific differences in adipose stem cells and their exosome content. PMID:27358894

  6. Paneth Cell-Rich Regions Separated by a Cluster of Lgr5+ Cells Initiate Crypt Fission in the Intestinal Stem Cell Niche.

    Science.gov (United States)

    Langlands, Alistair J; Almet, Axel A; Appleton, Paul L; Newton, Ian P; Osborne, James M; Näthke, Inke S

    2016-06-01

    The crypts of the intestinal epithelium house the stem cells that ensure the continual renewal of the epithelial cells that line the intestinal tract. Crypt number increases by a process called crypt fission, the division of a single crypt into two daughter crypts. Fission drives normal tissue growth and maintenance. Correspondingly, it becomes less frequent in adulthood. Importantly, fission is reactivated to drive adenoma growth. The mechanisms governing fission are poorly understood. However, only by knowing how normal fission operates can cancer-associated changes be elucidated. We studied normal fission in tissue in three dimensions using high-resolution imaging and used intestinal organoids to identify underlying mechanisms. We discovered that both the number and relative position of Paneth cells and Lgr5+ cells are important for fission. Furthermore, the higher stiffness and increased adhesion of Paneth cells are involved in determining the site of fission. Formation of a cluster of Lgr5+ cells between at least two Paneth-cell-rich domains establishes the site for the upward invagination that initiates fission. PMID:27348469

  7. Inflammatory Myofibroblastic t umor: A Benign Lesion with Malignant Behavior

    Directory of Open Access Journals (Sweden)

    Harishchandra Rai

    2015-07-01

    Full Text Available Inflammatory myofibroblastic tumors (IMTs comprise a rare group of lesions. Till date, fewer than 30 cases have been described in the paranasal sinuses. The purpose of this article is to report a case of I MT in maxillary sinus which is very rare and to highlight on its clinical and histological features. We present a case of IMT in a 46-year-old female patient who presented with pain and oroantral communication few weeks after the extraction of a molar tooth. Computed tomography scan report revealed a soft tissue lesion in the right maxilla with posterola teral bone destruction. Inflammatory myofibroblastic tumors may show neoplastic features, such as persistent local growth, recurrence, and metastasis, but the overall prognosis of the lesion is excellent. Most recurrences will occur within 1 year of initial surgery, with only a few reports of late recu r - rences. Follow-up should be at regular intervals during the first few years.

  8. Congenital peribronchial myofibroblastic tumor: Case report and review of literature

    Directory of Open Access Journals (Sweden)

    Jolanta Jedrzkiewicz

    2015-04-01

    Full Text Available Congenital peribronchial myofibroblastic tumor (CPMT is a rare entity recognized in the WHO classification of pulmonary neoplasms. According to available literature, it is a benign tumor with a high mortality rate exceeding 50%. It is partially attributed to polyhydramnios, hydrops, prematurity, respiratory distress or adverse surgical outcomes due to intraoperative bleeding. Herein we present a case of congenital peribronchial myofibroblastic tumor in a premature male infant who was born at 31 weeks gestation due to polyhydramnios and premature rupture of membranes. Soon after birth, he required intubation due to worsening respiratory distress. Imaging demonstrated a large right chest mass causing mediastinal shift. Surgical intervention was attempted, which was challenging due to intraoperative bleeding and tumor retraction. The patient expired soon after the surgery. Hence, in this report we would like to share our experience with this difficult diagnosis and treatment of this rare tumor.

  9. Inflammatory myofibroblastic tumors of the head and nec

    OpenAIRE

    Tao, Jiang; Zhou, Min-Li; ZHOU, SHUI-HONG

    2015-01-01

    Inflammatory myofibroblastic tumors (IMT) rarely affect the head and neck region. IMTs of the head and neck regions account for 14-18% of extra-pulmonary IMTs. Most commonly, they are located in the region of the orbits and upper airways, and less often at other sites. In the present study, we reviewed the English-language literature regarding the etiology, clinical features, diagnosis, treatment, and prognosis of IMTs of the head and neck.

  10. tPA Protects Renal Interstitial Fibroblasts and Myofibroblasts from Apoptosis

    OpenAIRE

    Hu, Kebin; Lin, Ling; Tan, Xiaoyue; Yang, Junwei; Bu, Guojun; Mars, Wendy M.; Liu, Youhua

    2008-01-01

    Activation and expansion of interstitial fibroblasts and myofibroblasts play an essential role in the evolution of renal fibrosis. After obstructive injury, mice lacking tissue-type plasminogen activator (tPA) have fewer myofibroblasts and less interstitial fibrosis than wild-type controls. This suggests that tPA controls the size of the fibroblast/myofibroblast population in vivo, and this study sought to determine the underlying mechanism. In vitro, tPA inhibited staurosporine or H2O2-induc...

  11. Astaxanthin prevents pulmonary fibrosis by promoting myofibroblast apoptosis dependent on Drp1-mediated mitochondrial fission

    OpenAIRE

    Zhang, Jinjin; Xu, Pan; Wang, Youlei; Wang, Meirong; Li, Hongbo; Lin, Shengcui; Mao, Cuiping; Wang, Bingsi; Song, Xiaodong; LV, CHANGJUN

    2015-01-01

    Promotion of myofibroblast apoptosis is a potential therapeutic strategy for pulmonary fibrosis. This study investigated the antifibrotic effect of astaxanthin on the promotion of myofibroblast apoptosis based on dynamin-related protein-1 (Drp1)-mediated mitochondrial fission in vivo and in vitro. Results showed that astaxanthin can inhibit lung parenchymal distortion and collagen deposition, as well as promote myofibroblast apoptosis. Astaxanthin demonstrated pro-apoptotic function in myofib...

  12. The Fluctuation Niche in Plants

    International Nuclear Information System (INIS)

    Classical approaches to niche in coexisting plants have undervalued temporal fluctuations. We propose that fluctuation niche is an important dimension of the total niche and interacts with habitat and life-history niches to provide a better understanding of the multidimensional niche space where ecological interactions occur. To scale a fluctuation niche, it is necessary to relate environmental constrictions or species performance not only to the absolute values of the usual environmental and eco physiological variables but also to their variances or other measures of variability. We use Mediterranean plant communities as examples, because they present characteristic large seasonal and inter annual fluctuations in water and nutrient availabilities, along an episodic-constant gradient, and because the plant responses include a number of syndromes coupled to this gradient.

  13. Towards an anti-fibrotic therapy for scleroderma: targeting myofibroblast differentiation and recruitment

    Directory of Open Access Journals (Sweden)

    Leask Andrew

    2010-05-01

    Full Text Available Abstract Background In response to normal tissue injury, fibroblasts migrate into the wound where they synthesize and remodel new extracellular matrix. The fibroblast responsible for this process is called the myofibroblast, which expresses the highly contractile protein α-smooth muscle actin (α-SMA. In normal tissue repair, the myofibroblast disappears. Conversely, abnormal myofibroblast persistence is a key feature of fibrotic dieases, including scleroderma (systemic sclerosis, SSc. Myofibroblasts can be derived from differentiation of local resident fibroblasts or by recruitment of microvascular pericytes. Clinical problem addressed Controlling myofibroblast differentiation and persistence is crucial for developing anti-fibrotic therapies targeting SSc. Basic science advances Insights have been recently generated into how the proteins transforming growth factor β (TGFβ, endothelin-1 (ET-1, connective tissue growth factor (CCN2/CTGF and platelet derived growth factor (PDGF contribute to myofibroblast differentiation and pericyte recruitment in general and to the persistent myofibroblast phenotype of lesional SSc fibroblast, specifically. Relevance to clinical care This minireview summarizes recent findings pertinent to the origin of myofibroblasts in SSc and how this knowledge might be used to control the fibrosis in this disease. Conclusions TGFβ, ET-1, CCN2 and PDGF are likely to cooperate in driving tissue repair and fibrogenic responses in fibroblasts. TGFβ, ET-1 and CCN2 appear to contribute to myofibroblast differentiation; PDGF appears to be involved with pericyte recruitment. Thus, different therapeutic strategies may exist for targeting the multisystem fibrotic disorder SSc.

  14. Niching as a Macrostructural Procedure*

    OpenAIRE

    Rufus H Gouws

    2011-01-01

    Abstract: Niching is a macrostructural procedure of textual condensation which results in different dictionary articles being clustered into one textblock as subarticles headed by sublemmata. This article offers an identification and critical discussion of different types of niching. Examples from dictionaries are used to examine problems which dictionary users experience as a result of the application of niching. The emphasis is on problems regarding the search route of users via th...

  15. Primary Tumor-Secreted Lymphangiogenic Factors Induce Pre-Metastatic Lymphvascular Niche Formation at Sentinel Lymph Nodes in Oral Squamous Cell Carcinoma.

    Directory of Open Access Journals (Sweden)

    Naohiro Wakisaka

    Full Text Available The objectives of this study were to evaluate the formation of lymphvascular niches in lymph nodes of patients with oral squamous cell carcinoma (OSCC, and investigate the roles of lymphangiogenic and angiogenic factors, such as vascular endothelial growth factor (VEGF-A, VEGF-C, and VEGF-D, expressed in the primary tumors.Forty-four patients with previously untreated clinically late T2 or T3 OSCC of cN0 were evaluated for primary tumors and 166 sentinel lymph nodes (SLNs. Primary tumors were immunohistochemically analyzed for expressions of VEGFs. Densities of lymphatic vessels (LVDpodoplanin and high endothelial venules (HEVD in the SLNs were also calculated using antibodies for each marker, podoplanin and MECA-79, respectively.In 25 patients, all lymph nodes were metastasis-negative, whereas, in 19 patients, metastasis was positive for at least one lymph node (either at SLN, non-SLN, or nodal recurrence. From the analyses of 140 SLNs without metastasis, LVDpodoplanin in 50 SLNs of metastasis-positive cases was significantly higher than that in 90 SLNs of metastasis-negative cases (p = 0.0025. HEVD was not associated with lymph node metastasis. The patients with VEGF-A-High or VEGF-D-High tumors had significantly higher LVDpodoplanin than patients with their Low counterparts (p = 0.0233 and p = 0.0209, respectively. In cases with lymph node metastasis, the VEGF-D-expression score was significantly higher than in those without lymph node metastasis (p = 0.0006.These results suggest that lymph node lymphangiogenesis occurs before metastasis in OSCC. VEGF-A and VEGF-D play critical roles in this process. VEGF-D is a potential predictive marker of positive lymph node metastasis in cN0 patients.

  16. Circumbinary Habitability Niches

    CERN Document Server

    Mason, Paul A; Cuartas-Restrepo, Pablo A; Clark, Joni M

    2014-01-01

    Binaries could provide the best niches for life in the galaxy. Though counterintuitive, this assertion follows directly from stellar tidal interaction theory and the evolution of lower mass stars. There is strong evidence that chromospheric activity of rapidly rotating young stars may be high enough to cause mass loss from atmospheres of potentially habitable planets. The removal of atmospheric water is most critical. Tidal breaking in binaries could help reduce magnetic dynamo action and thereby chromospheric activity in favor of life. We call this the Binary Habitability Mechanism (BHM), that we suggest allows for water retention at levels comparable to or better than Earth. We discuss novel advantages that life may exploit, in these cases, and suggest that life may even thrive on some circumbinary planets. We find that while many binaries do not benefit from BHM, high quality niches do exist for various combinations of stars between 0.55 and 1.0 solar masses. For a given pair of stellar masses, BHM operate...

  17. The prostate cancer bone marrow niche: more than just ‘fertile soil’

    Institute of Scientific and Technical Information of China (English)

    Elisabeth A Pedersen; Yusuke Shiozawa; Kenneth J Pienta; Russell S Taichman

    2012-01-01

    The hematopoietic stem cell (HSC) niche in the bone marrow has been studied extensively over the past few decades,yet the bone marrow micmenvironment that supports the growth of metastatic prostate cancer (PCa) has only been recently considered to be a specialized ‘niche' as well.New evidence supports the fact that disseminated tumor cells (DTCs) of PCa actually target the HSC niche,displace the occupant HSCs and take up residence in the pre-existing niche space.This review describes some of the evidence and mechanisms by which DTCs act as molecular parasites of the HSC niche.Furthermore,the interactions between DTCs,HSCs and the niche may provide new targets for niche-directed therapy,as well as insight into the perplexing clinical manifestations of metastatic PCa disease.

  18. Transforming growth factor-β1 induces intestinal myofibroblast differentiation and modulates their migration

    Institute of Scientific and Technical Information of China (English)

    Julia Brenmoehl; Sandra Nicole Miller; Claudia Hofmann; Daniela Vogl; Werner Falk; Jürgen Scholmerich; Gerhard Rogler

    2009-01-01

    AIM:To investigate the effects of transforming growth factor β1 (TGF-β1) on the differentiation of colonic lamina propria fibroblasts (CLPF) into myofibroblasts in vitro. METHODS:Primary CLPF cultures were incubated with TGF-β1 and analyzed for production of α-smooth muscle actin (α-SMA), fibronectin (FN) and FN isoforms. Migration assays were performed in a modified 48-well Boyden chamber. Levels of total and phosphorylated focal adhesion kinase (FAK) in CLPF were analyzed after induction of migration. RESULTS:Incubation of CLPF with TGF-β1 for 2 d did not change α-SMA levels, while TGF-β1 treatment for 6 d significantly increased α-SMA production. Short term incubation (6 h) with TGF-β1 enhanced CLPF migration, while long term treatment (6 d) of CLPF with TGF-β1 reduced migration to 15%-37% compared to untreated cells. FN and FN isoform mRNA expression were increased after short term incubation with TGF-β1 (2 d) in contrast to long term incubation with TGF-β1 for 6 d. After induction of migration, TGF-β1-preincubated CLPF showed higher amounts of FN and its isoforms and lower levels of total and phosphorylated FAK than untreated cells. CONCLUSION:Long term incubation of CLPF with TGF-β1 induced differentiation into myofibroblasts with enhanced α-SMA, reduced migratory potential and FAK phosphorylation, and increased FN production. In contrast, short term contact (6 h) of fibroblasts with TGF-β1 induced a dose-dependent increase of cell migration and FAK phosphorylation without induction of α-SMA production.

  19. Radiological and histopathological features of hepatic inflammatory myofibroblastic tumour: Analysis of 10 cases

    International Nuclear Information System (INIS)

    Aim: To evaluate the radiological and histopathological features of hepatic inflammatory myofibroblastic tumours (IMTs), and improve the understanding of this tumour. Materials and methods: A retrospective analysis of radiological and histopathological features of 10 cases of IMT was carried out from May 2003 to September 2011 at the Second Xiangya Hospital of Central South University. Results: Ten cases (five male and five female patients; age range 4–68 years) were enrolled. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed that the lesions were regular, hypodense or hypointense (T1WI) masses with well-defined borders (n = 8) or ill-defined borders (n = 2). The maximum diameter ranged from 3.1–13.4 cm (mean = 6 cm). The masses showed homogeneous (n = 8) or inhomogeneous (n = 2) density. Contrast-enhanced CT and MRI showed the lesions were mildly, irregularly enhanced (n = 7) or not enhanced (n = 2) in the arterial phase and markedly enhanced in the portal venous phase or delayed phase. Hepatic arteriography revealed that the lesions were hypovascular and had a well-defined border. One patient had lung metastasis with obvious arterial phase enhancement. None of the patients had a history of hepatitis, cirrhosis, or enlarged lymph nodes. Pathology showed that the gross appearance of the tumours was smooth. The tumour cells comprised spindle-shaped fibroblast and myofibroblast cells with abundant inflammatory cells. Immunohistochemistry showed that most were positive for vimentin, smooth muscle actin (SMA), and CD68, but negative for CD34, anaplastic lymphoma kinase (ALK), S-100, and CD117. Conclusion: Radiological features of IMT have some characteristics of an intermediate-grade malignant tumour. However, imaging alone cannot be used to diagnose IMT. Therefore, histopathological examination is necessary for confirmation

  20. Short chain fatty acids stimulate epithelial mucin 2 expression through differential effects on prostaglandin E(1) and E(2) production by intestinal myofibroblasts

    OpenAIRE

    Willemsen, L.E.; Koetsier, M A; Deventer, van, S.J.H.; Tol, van, M.J.

    2003-01-01

    Background: The mucus layer protects the gastrointestinal mucosa from mechanical, chemical, and microbial challenge. Mucin 2 (MUC-2) is the most prominent mucin secreted by intestinal epithelial cells. There is accumulating evidence that subepithelial myofibroblasts regulate intestinal epithelial cell function and are an important source of prostaglandins (PG). PG enhance mucin secretion and are key players in mucoprotection. The role of bacterial fermentation products in these processes dese...

  1. Monument og niche

    DEFF Research Database (Denmark)

    Juel-Christiansen, Carsten

    2009-01-01

    Introduktion til og uddrag af bogen: Monument og niche : den ny bys arkitektur / af Carsten Juel-Christiansen, 1985......Introduktion til og uddrag af bogen: Monument og niche : den ny bys arkitektur / af Carsten Juel-Christiansen, 1985...

  2. Stem Cell Niche and Its Roles in Proliferation and Differentiation of Stem Cells%干细胞niche及其在干细胞增殖分化中的作用

    Institute of Scientific and Technical Information of China (English)

    宋远会; 宋关斌

    2009-01-01

    干细胞(Stem cells)是一类具有自我更新和多向分化潜能的特殊细胞.在特定的条件下,干细胞可以增殖并分化为多种类型的细胞,但干细胞的增殖、分化行为高度依赖于其所处的生长小生态环境,即干细胞niche.干细胞与其niche之间通过相互的"时空对话"(Spatiotemporal dialog)实现自我更新和分化的平衡调控.本文对几种不同类型的niche及其与干细胞的相互关系做一简要介绍.

  3. Mesenteric inflammatory myofibroblastic tumors in an elder patient with early recurrence: A case report

    Institute of Scientific and Technical Information of China (English)

    Sheng-Shih Chen; Shiuh-Inn Liu; King-Tong Mok; Being-Whey Wang; Ming-Hsin Yeh; Yu-Chia Chen; I-Shu Chen

    2007-01-01

    Inflammatory myofibroblastic tumor (IMT) of the alimentary tract often occurs in children or young adults,but may occur at any age. Symptoms are nonspecific and depend on the location of the tumor. The most often involved sites are small bowel mesentery especially the distal ileum, mesotransverse colon, or great omentum. Recurrence appears to be more frequent in the extrapulmonary lesion. Herein we demonstrate a 63-year-old male patient with mesenteric IMT, with an early recurrence after his first operation. We should be aware that if the tumor is larger than 8 cm, multinodular,omental, with ill-defined margin, with pathologically atypia, or ganglion-like cells, a close surveillence after primary surgery with image study might be necessary to detect the tumor recurrence early. Tumor recurrence may be asymptomatic, and it may act like a malignant tumor with a poor prognosis.

  4. GLP-2 stimulates colonic growth via KGF, released by subepithelial myofibroblasts with GLP-2 receptors

    DEFF Research Database (Denmark)

    Ørskov, Cathrine; Hartmann, Bolette; Poulsen, Steen Seier;

    2005-01-01

    BACKGROUND: Glucagon-like peptide-2 is thought to act as a growth factor for the gut, but the localization of the GLP-2 receptor and mechanism of action on epithelial growth is unclear. METHODS AND RESULTS: We found glucagon-like peptide-2 (GLP-2) receptors mainly on subepithelial myofibroblasts in...... rat, mouse, marmoset and human small and large intestine by immunohistochemistry and in situ hybridisation. By double labelling we found that these GLP-2 receptor immunoreactive cells also produce smooth muscle actin and keratinocyte growth factor (KGF). By subcutaneous infusion of either GLP-2 alone......, GLP-2 plus KGF antibody, KGF antibody alone or saline in mice, we found that KGF antibody abolished the growth promoting effect of GLP-2 in the large intestine, but not in the small intestine. CONCLUSIONS: Our findings suggest that GLP-2 in the gut acts by activating receptors on the subepithelial...

  5. Inflammatory myofibroblastic tumor of the bladder in a child: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Araujo Filho, Jose de Arimateia Batista, E-mail: ariaraujocg@hotmail.com [Radiology and Imaging Diagnosis, Instituto do Coracao (InCor) - Universidade de Sao Paulo (HC-FMUSP), Sao Paulo, SP (Brazil); Martines, Joao Augusto dos Santos; Martines, Brenda Margatho Ramos [Imaging Unit of Hospital Universitario - Universidade de Sao Paulo (HU-USP), Sao Paulo, SP (Brazil); Cavalcanti, Marcella Santos [Pathology, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo (HC-FMUSP), Sao Paulo, SP (Brazil); Cerri, Giovanni Guido; Castro, Claudio Campi de [Department of Radiology, Faculdade de Medicina da Universidade de Sao Paulo (FMUSP), Sao Paulo, SP (Brazil)

    2012-07-15

    Inflammatory myofibroblastic tumors rarely affect the urinary tract or children, and frequently mimic malignancy on imaging studies. According to the recent literature, only 35 cases of such bladder tumors in children have been reported. The authors present the case of a child with a bladder myofibroblastic tumor with favorable progression following complete surgical resection. (author)

  6. The niche of envy

    DEFF Research Database (Denmark)

    Quintanilla, Laura; Jensen de López, Kristine M.

    2013-01-01

    .g., socio-cultural, psychological, and anthropological research. Finally, in the third section, we introduce a cross-cultural and developmental view of how envy is embodied. We briefly address and offer a critique of Klein’s psychoanalytic view and present recent results from our cross-cultural studies of......Envy is the religion of the mediocre. It comforts them, it responds to the worries that gnaw at them and finally it rots their souls, allowing them to justify their meanings and their greed until they believe these to be virtues.—Carlos Ruiz Zafón “The niche of envy” is a cross-disciplinary attempt...... to capture and understand the complex and self-conscious emotion of envy as unfolded within social relationships and cultural settings. One of our main interests concerns how children come to understand envy in ontogenesis. Accordingly, we review existing theoretical approaches to understanding envy...

  7. Exosomes as novel regulators of adult neurogenic niches

    Directory of Open Access Journals (Sweden)

    Luis Federico Batiz

    2016-01-01

    Full Text Available Adult neurogenesis has been convincingly demonstrated in two regions of the mammalian brain: the sub-granular zone (SGZ of the dentate gyrus (DG in the hippocampus, and the sub-ventricular zone (SVZ of the lateral ventricles. SGZ newborn neurons are destined to the granular cell layer of the DG, while new neurons from the SVZ neurons migrate rostrally into the olfactory bulb. The process of adult neurogenesis persists throughout life and is supported by a pool of neural stem cells (NSCs, which reside in a unique and specialized microenvironment known as neurogenic niche. Neurogenic niches are structured by a complex organization of different cell types, including the NSC-neuron lineage, glial cells and vascular cells. Thus, cell-to-cell communication plays a key role in the dynamic modulation of homeostasis and plasticity of the adult neurogenic process. Specific cell-cell contacts and extracellular signals originated locally provide the necessary support and regulate the balance between self-renewal and differentiation of NSCs. Furthermore, extracellular signals originated at distant locations, including other brain regions or systemic organs, may reach the niche through the cerebrospinal fluid or the vasculature and influence its nature. The role of several secreted molecules, such as cytokines, growth factors, neurotransmitters, and hormones, in the biology of adult NSCs, has been systematically addressed. Interestingly, in addition to these well-recognized signals, a novel type of intercellular messengers has been identified recently: the extracellular vesicles (EVs. EVs, and particularly exosomes, are implicated in the transfer of mRNAs, microRNAs (miRNAs, proteins and lipids between cells and thus are able to modify the function of recipient cells. Exosomes appear to play a significant role in different stem cell niches such as the mesenchymal stem cell niche, cancer stem cell niche and pre-metastatic niche; however, their roles in adult

  8. Pelvic inflammatory myofibroblastic tumor mimicking a rectal cancer

    Directory of Open Access Journals (Sweden)

    Lídia Roque-Ramos

    2016-01-01

    Full Text Available We report a case of a 50-year-old woman who presented to the emergency department with large bowel obstruction and anemia. The initial imaging study suggested an inoperable rectal tumor with involvement of surrounding structures. In this paper, we discuss the diagnostic work-up of this patient with a diagnosis of pelvic/perirectal inflammatory myofibroblastic tumor (IMT. IMT is a rare tumor with intermediate malignant potential that frequently mimics clinical and imaging features of malignancy. Additionally, to the best of our knowledge, this is the first case of a pelvic IMT that regressed without surgical excision.

  9. Medical therapy of maxillary sinus inflammatory myofibroblastic tumors.

    Science.gov (United States)

    Kim, Jong Seung; Hong, Ki Hwan; Kim, June Sun; Song, Jong Hoon

    2016-01-01

    Inflammatory myofibroblastic tumor (IMT) in the maxillary sinus is a diagnostic challenge. As IMT has various names, it has various findings in magnetic resonance image. Although destructive pattern in computed tomography and hypermetabolism in PET CT suggest malignancy, it is debatable whether it is a tumor or inflammatory lesion. Treatment of IMT usually includes surgery. However, IMT can be dealt with medical treatment according to histologic type and localization. We report a rare case of IMT in the maxillary sinus which is controlled by medical therapy. PMID:27038822

  10. Flavonol-rich fractions of yaupon holly leaves (Ilex vomitoria, Aquifoliaceae) induce microRNA-146a and have anti-inflammatory and chemopreventive effects in intestinal myofibroblast CCD-18Co cells.

    Science.gov (United States)

    Noratto, Giuliana D; Kim, Youngmok; Talcott, Stephen T; Mertens-Talcott, Susanne U

    2011-06-01

    Polyphenolics extracted from yaupon holly (Ilex vomitoria, Aquifoliaceae) (YH) leaves were investigated in human colon cells for their chemopreventive and anti-inflammatory activities. An activity-guided fractionation allowed the selection of YH flavonol-rich fraction due to its preferential inhibition of HT-29 colon cancer viability over the normal CCD-18Co colon cells. Quercetin and kaempferol 3-rutinosides, main components identified in this fraction, protected CCD-18Co cells against reactive oxidative species (ROS) in part due to increased activity of antioxidant enzymes. In addition, up-regulation of microRNA-146a (miR-146a) known as a negative regulator of pro-inflammatory NF-κB activation was the underlying molecular mechanism that protected CCD-18Co from inflammation. PMID:21262328

  11. The myofibroblast markers α-SM actin and β-actin are differentially expressed in 2 and 3-D culture models of fibrotic and normal skin.

    Science.gov (United States)

    Vozenin, M C; Lefaix, J L; Ridi, R; Biard, D S; Daburon, F; Martin, M

    1998-01-01

    To characterize the differences between fibrotic myofibroblasts and normal fibroblasts, we studied two differentiation markers: α-smooth muscle (SM) actin, a specific marker of myofibroblast differentiation, and β-actin, which is overexpressed in the fibrotic tissue. Experiments were performed on fibroblasts isolated from normal pig skin and on subcutaneous myofibroblasts isolated from pig radiation-induced fibrosis. Three culture models were used: cells in monolayers, equivalent dermis, consisting of fibroblasts embedded into a matrix composed of type I collagen, and in vitro reconstituted skin, in which the matrix and containing life fibroblasts were overlaid with keratinocytes. Samples were studied using immunofluorescence and western-blotting. In monolayers cultures, both fibrosis and normal cells expressed α-SM actin. Furthermore, similar amounts of β-actin protein were found. In these conditions, the resulting alterations in the phenotypes of cells made comparison of cultured fibrotic and normal cells irrelevant. Under the two 3-D culture models, normal fibroblasts no longer expressed α-SM actin. They expressed β-actin at the basal level. Moreover, the fibrotic myofibroblasts in both 3-D models retained their differentiation features, expressing α-SM actin and overexpressing β-actin. We found that this normalization was mainly related to the genomic programmation acquired by the cells in the tissue. Cellular motility and microenvironment were also involved, whereas cellular proliferation was not a major factor. Consequently, both three-dimensional models allowed the study of radiation-induced fibrosis in vitro, provided good extrapolations to in vivo conditions and avoided certain of culture artefacts. PMID:22359004

  12. Chylous Ascites in a Patient with Inflammatory Myofibroblastic Tumor

    Directory of Open Access Journals (Sweden)

    Sascha Dietrich

    2009-08-01

    Full Text Available Background: We present the case of a 64-year-old patient who presented to his primary care physician with fatigue, worsening shortness of breath, abdominal discomfort and a rapidly growing abdominal girth, although he had lost 5 kg of weight within 3 months. He had a history of untreated hypertension, compensated renal insufficiency and COPD. Despite weight loss and fatigue, the patient did not experience any other constitutional symptoms such as fever, night sweats or loss of appetite. Investigations: Physical examination, blood tests, CT scan of the abdomen, MRI scan of the abdomen, fine needle biopsy, excisional biopsy, Video Capsule Endoscopy, histology, PET scan. Diagnosis: Inflammatory myofibroblastic tumor, chylous ascites, chyloperitoneum. Management: Systemic chemotherapy, total parenteral nutrition and octreotide therapy. Conclusion: We describe the case of a patient in whom two extremely rare phenomena are present in combination: the diagnosis of an inflammatory myofibroblastic tumor and chylous ascites. While the tumor could be stabilized by different regimens of chemotherapy, the chyloperitoneum was treated with parenteral nutrition and subcutaneous octreotide injections, which resulted in a significant reduction of the amount of chylous ascites drained during regular paracentesis.

  13. Roles of myofibroblasts and notch and hedgehog signaling pathways in the formation of intrahepatic bile duct lesions in polycystic kidney rats.

    Science.gov (United States)

    Furubo, Shinichi; Sato, Yasunori; Harada, Kenichi; Nakanuma, Yasuni

    2013-01-01

    Polycystic kidney (PCK) rats, an animal model of Caroli's disease, show a dilatation of intrahepatic bile ducts (IHBD) called "ductal plate malformation." Mesenchymal cells and the Notch and Hedgehog signaling pathways in portal tracts are reportedly involved in the normal development of IHBD, although there have been no studies on the roles of these signaling pathways in PCK rats. We immunohistochemically examined the expression of the molecules related to these signaling pathways in portal tracts. All molecules related to these signaling pathways expressed in portal tracts in Sprague Dawley (SD) rats (control) were also expressed in PCK rats. Mesenchymal cells (myofibroblasts) were frequently found in the connective tissue of portal tracts of 20 embryonic-day-old (E20D), 1-day-old (1D), and 1-week-old (1W) SD and PCK rats and were abundant in PCK rats. Interestingly, myofibroblasts almost disappeared at in both strains of 3W rats. Jagged1 was expressed in mesenchymal cells in portal tracts and was abundant in PCK rats. Double immunostaining showed that Jagged1-positive cells were myofibroblasts. Notch2 and HES1 were expressed in cholangiocytes of the bile ducts of both rats. Sonic Hedgehog was similarly expressed in the bile ducts of both rats. A well-balanced and time-sequential expression of the Notch and Hedgehog family in portal tracts might be essential for the normal development of IHBD in E20D to 1W SD rats, and an imbalanced interaction of these molecules, particularly increased Jagged1 expression in periductal and periportal myofibroblasts and Notch2 expressed in cholangiocytes, may be involved in the formation of bile duct lesions in PCK rats. PMID:23331119

  14. The pitfalls of niche marketing.

    Science.gov (United States)

    Raynor, M E

    1992-01-01

    Corporate marketers have jumped on the micromarketing bandwagon, but many have discovered that the path to profits contains a number of potholes. This article details three companies' niche marketing mistakes; the author suggests how to avoid them. PMID:10117142

  15. Phylogenetic comparative approaches for studying niche conservatism

    OpenAIRE

    COOPER, NATALIE; Jetz, Walter; Freckleton, Rob P.

    2010-01-01

    Analyses of phylogenetic niche conservatism (PNC) are becoming increasingly common. However, each analysis makes subtly different assumptions about the evolutionary mechanism that generates patterns of niche conservatism. To understand PNC, analyses should be conducted with reference to a clear underlying model, using appropriate methods. Here, we outline five macroevolutionary models that may underlie patterns of PNC (drift, niche retention, phylogenetic inertia, niche filling ? shifti...

  16. Exosomes as Novel Regulators of Adult Neurogenic Niches

    Science.gov (United States)

    Bátiz, Luis Federico; Castro, Maite A.; Burgos, Patricia V.; Velásquez, Zahady D.; Muñoz, Rosa I.; Lafourcade, Carlos A.; Troncoso-Escudero, Paulina; Wyneken, Ursula

    2016-01-01

    Adult neurogenesis has been convincingly demonstrated in two regions of the mammalian brain: the sub-granular zone (SGZ) of the dentate gyrus (DG) in the hippocampus, and the sub-ventricular zone (SVZ) of the lateral ventricles (LV). SGZ newborn neurons are destined to the granular cell layer (GCL) of the DG, while new neurons from the SVZ neurons migrate rostrally into the olfactory bulb (OB). The process of adult neurogenesis persists throughout life and is supported by a pool of neural stem cells (NSCs), which reside in a unique and specialized microenvironment known as “neurogenic niche”. Neurogenic niches are structured by a complex organization of different cell types, including the NSC-neuron lineage, glial cells and vascular cells. Thus, cell-to-cell communication plays a key role in the dynamic modulation of homeostasis and plasticity of the adult neurogenic process. Specific cell-cell contacts and extracellular signals originated locally provide the necessary support and regulate the balance between self-renewal and differentiation of NSCs. Furthermore, extracellular signals originated at distant locations, including other brain regions or systemic organs, may reach the niche through the cerebrospinal fluid (CSF) or the vasculature and influence its nature. The role of several secreted molecules, such as cytokines, growth factors, neurotransmitters, and hormones, in the biology of adult NSCs, has been systematically addressed. Interestingly, in addition to these well-recognized signals, a novel type of intercellular messengers has been identified recently: the extracellular vesicles (EVs). EVs, and particularly exosomes, are implicated in the transfer of mRNAs, microRNAs (miRNAs), proteins and lipids between cells and thus are able to modify the function of recipient cells. Exosomes appear to play a significant role in different stem cell niches such as the mesenchymal stem cell niche, cancer stem cell niche and pre-metastatic niche; however, their

  17. Ecological niche of plant pathogens

    OpenAIRE

    Ecaterina Fodor

    2011-01-01

    Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in ni...

  18. [Mechanism of tanshinone II A in inhibiting transformation of aortic valvular myofibroblast to osteoblast-like phenotype].

    Science.gov (United States)

    Shen, Ying-nian; Hu, Wei-lin; Chen, Zheng-ping; Cai, Li; Li, Yong-sheng

    2015-09-01

    Aortic valve calcification (AVC) is a pathological process correlated with multiple disease causes and actively regulated by cardiac valve cells. In this study, porcine aortic valve myofibroblasts cultured in vitro were treated with 50 μg z L(-1) of pathological factor tumor necrosis factor α (TNF-α). Tanshinone II A (TSN) with the concentration of 50 mg x L(-1) and TNF-α were combined in incubating cells for 72 h (3 d) and 120 h (5 d). The Western blotting and Real-time PCR were adopted to detect the changes in smooth muscle α actin (α-SMA), bone morphogenetic protein 2 ( BMP2), alkaline phosphatase (ALP) in cells, and expressions of key effect proteins GSK-3β and β-catenin on Wnt/β-catenin signal pathway. According to the findings, TNF-α can significantly increase the expression of myofibroblasts α-SMA and add the transformation activity to them, with nearly no expression of BMP2, ALP and mRNA in the control group and the TSN group but significant increase in their expressions in the TNF-α group (P AVC. Tanshinone II A can have a preventive effect in AVC by activating GSK-3β proteins and regulating signal transduction of Wnt/β-catenin signal pathway. PMID:26983213

  19. Myofibroblastic sarcoma of the base of tongue. Case report and review of the literature

    International Nuclear Information System (INIS)

    Background: Mesenchymal malignancies with myofibroblastic differentiation exhibit a spectrum from low-grade myofibroblastic sarcoma mimicking fibromatosis to pleomorphic high-grade sarcoma. Low-grade myofibroblastic sarcoma shows a wide anatomic distribution with a predilection for the head-and-neck region; however, intermediate- and high-grade myofibroblastic sarcomas in this localization are exceptional. Case Report: A 56-year-old woman with intermediate-grade myofibroblastic sarcoma of the base of tongue is presented. She was treated with surgical excision, but computed tomography proved local residual tumor. Reexcision and chemotherapy were refused by the patient. Irradiation was given to a total dose of 66 Gy. Result: 50 months after completion of radiotherapy, the patient is in good health without any evidence of disease. According to the review of the literature, base of tongue as the primary site of myofibroblastic sarcoma has not been published so far. Conclusion: Similarly to the low-grade form, intermediate- and high-grade myofibroblastic sarcomas may also occur in the head-and-neck region. In case of incomplete excision, radiotherapy may be an effective treatment. (orig.)

  20. Niche modelling of salt marsh plant species

    International Nuclear Information System (INIS)

    This study sought to extend the niche model of Spartina anglica to other salt marsh species, and to include tidal submergence in the models. The method used and preliminary data analysis are described. Tidal level and submergence niche models are examined, and niche width, niche overlap and species interaction are considered. Tidal level models and submergence niche models are compared for the 5 most common species. (UK)

  1. Hypothesis: The metastatic niche theory can elucidate infantile hemangioma development

    OpenAIRE

    Mihm, Martin C.; Nelson, J Stuart

    2010-01-01

    Recent advances in the understanding of the metastatic phenomenon in cancer have led to the description of a metastatic niche. This concept describes a site prepared for the tumor cells in areas frequently associated with metastasis for the individual tumor studied. This niche is a “soil” that allows for the tumor cell or “seed” to lodge and grow. Certain aspects of the biology of infantile hemangioma cells suggest a relationship to the placenta as a possible site of origin for the hemangioma...

  2. Cytometry by Time-of-Flight Shows Combinatorial Cytokine Expression and Virus-Specific Cell Niches within a Continuum of CD8+ T Cell Phenotypes

    OpenAIRE

    Newell, Evan W; Sigal, Natalia; Bendall, Sean C.; Garry P Nolan; Davis, Mark M.

    2012-01-01

    Cytotoxic CD8+ T lymphocytes directly kill infected or aberrant cells and secrete proinflammatory cytokines. By using metal-labeled probes and mass spectrometric analysis (cytometry by time-of-flight, or CyTOF) of human CD8+ T cells, we analyzed the expression of many more proteins than previously possible with fluorescent labels, including surface markers, cytokines, and antigen specificity with modified peptide-MHC tetramers. With 3-dimensional principal component analysis (3D-PCA) to displ...

  3. Cardiac inflammatory myofibroblastic tumor: does it recur after complete surgical resection in an adult?

    Directory of Open Access Journals (Sweden)

    Yang Xuedong

    2012-05-01

    Full Text Available Abstract Inflammatory myofibroblastic tumor is currently considered to be a low-grade neoplasm, and it rarely involves the heart. We reported a rare case of a 59-year-old female who received cardiac surgery for complete resection of inflammatory myofibroblastic tumor in the left atrium. Five months after surgery, the patient presented with acute cardiogenic pulmonary edema and subsequent sudden death due to a left atrial tumor which protruded into the left ventricle through mitral annulus during diastole. The recurrence of inflammatory myofibroblastic tumor in the left atrium was strongly suggested clinically.

  4. Radio-induced superficial fibrosis: investigation of the activation mechanisms of the myo-fibroblast and characterization of the cicatricial epidermis

    International Nuclear Information System (INIS)

    Whereas radio-induced cutaneous fibrosis is one of the frequent after-effects of accidental and therapeutic irradiations, this research thesis addresses the mechanisms which govern the activation of the myo-fibroblast. After some results obtained on cells from a radio-induced fibrosis on swine cells, the author proposes a signalling alteration as a mechanism. In a model a reconstructed skin, the author shows that myo-fibroblasts are a direct target of Superoxide Dismutase (SOD), and respond to this anti-fibrosis agent by a phenotype reversion. She reports the molecular characterization of epidermis of fibro-necrosis human lesions induced by an accidental or therapeutic irradiation. This leads to a better understanding of the role of the myo-fibroblast during the development and regression of fibrosis. Besides, the author shows that an alteration of the epidermis adjacent to dermis is developing in parallel with the fibrosis process. This suggests an active contribution of keratinocytes during the development of this radio-induced after-effect

  5. Fibrocytes and the tissue niche in lung repair.

    Science.gov (United States)

    Andersson-Sjöland, Annika; Nihlberg, Kristian; Eriksson, Leif; Bjermer, Leif; Westergren-Thorsson, Gunilla

    2011-01-01

    Human fibrocytes are bone marrow-derived mesenchymal progenitor cells that express a variety of markers related to leukocytes, hematopoietic stem cells and a diverse set of fibroblast phenotypes. Fibrocytes can be recruited from the circulation to the tissue where they further can differentiate and proliferate into various mesenchymal cell types depending on the tissue niche. This local tissue niche is important because it modulates the fibrocytes and coordinates their role in tissue behaviour and repair. However, plasticity of a niche may be co-opted in chronic airway diseases such as asthma, idiopathic pulmonary fibrosis and obliterative bronchiolitis. This review will therefore focus on a possible role of fibrocytes in pathological tissue repair processes in those diseases. PMID:21658209

  6. Fibrocytes and the tissue niche in lung repair

    Directory of Open Access Journals (Sweden)

    Bjermer Leif

    2011-06-01

    Full Text Available Abstract Human fibrocytes are bone marrow-derived mesenchymal progenitor cells that express a variety of markers related to leukocytes, hematopoietic stem cells and a diverse set of fibroblast phenotypes. Fibrocytes can be recruited from the circulation to the tissue where they further can differentiate and proliferate into various mesenchymal cell types depending on the tissue niche. This local tissue niche is important because it modulates the fibrocytes and coordinates their role in tissue behaviour and repair. However, plasticity of a niche may be co-opted in chronic airway diseases such as asthma, idiopathic pulmonary fibrosis and obliterative bronchiolitis. This review will therefore focus on a possible role of fibrocytes in pathological tissue repair processes in those diseases.

  7. Mist1 Expressing Gastric Stem Cells Maintain the Normal and Neoplastic Gastric Epithelium and Are Supported by a Perivascular Stem Cell Niche

    Czech Academy of Sciences Publication Activity Database

    Hayakawa, Y.; Ariyama, H.; Stančíková, Jitka; Sakitani, S.; Asfaha, S.; Renz, B.W.; Dubeykovskaya, Z.A.; Shibata, W.; Wang, H.S.; Westphalen, C.B.; Chen, X.W.; Takemoto, Y.; Kim, W.; Khurana, S.S.; Tailor, Y.; Nagar, K.; Tomita, H.; Hara, A.; Sepulveda, A.R.; Setlik, W.; Gershon, M.D.; Saha, S.; Ding, L.; Shen, Z.L.; Fox, J.G.; Friedman, R.A.; Konieczny, S.F.; Worthley, D.; Kořínek, Vladimír; Wang, T.C.

    2015-01-01

    Roč. 28, č. 6 (2015), s. 800-814. ISSN 1535-6108 R&D Projects: GA ČR GAP305/11/1780; GA ČR(CZ) GA14-33952S Institutional support: RVO:68378050 Keywords : Innate lymphoid-cells * Intraepithelial neoplasia * Maintenance Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 23.523, year: 2014

  8. Shedding light on inflammatory pseudotumor in children: spotlight on inflammatory myofibroblastic tumor

    International Nuclear Information System (INIS)

    Inflammatory pseudotumor is a generic term used to designate a heterogeneous group of inflammatory mass-forming lesions histologically characterized by myofibroblastic proliferation with chronic inflammatory infiltrate. Inflammatory pseudotumor is multifactorial in etiology and generally benign, but it is often mistaken for malignancy given its aggressive appearance. It can occur throughout the body and is seen in all age groups. Inflammatory pseudotumor has been described in the literature by many organ-specific names, resulting in confusion. Recently within this generic category of inflammatory pseudotumor, inflammatory myofibroblastic tumor has emerged as a distinct entity and is now recognized as a fibroblastic/myofibroblastic neoplasm with intermediate biological potential and occurring mostly in children. We present interesting pediatric cases of inflammatory myofibroblastic tumors given this entity's tendency to occur in children. Familiarity and knowledge of the imaging features of inflammatory pseudotumor can help in making an accurate diagnosis, thereby avoiding unnecessary radical surgery. (orig.)

  9. Shedding light on inflammatory pseudotumor in children: spotlight on inflammatory myofibroblastic tumor

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Lillian M.; Kao, Simon C.S.; Moritani, Toshio; Clark, Eve; Ishigami, Kousei; Sato, Yutaka [University of Iowa Hospitals and Clinics, Department of Radiology, Carver College of Medicine, Iowa City, IA (United States); McCarville, M.B. [St. Jude Children' s Research Hospital, Department of Radiology, Memphis, TN (United States); Kirby, Patricia [University of Iowa Hospitals and Clinics, Department of Pathology, Carver College of Medicine, Iowa City, IA (United States); Bahrami, Armita [St. Jude Children' s Research Hospital, Department of Pathology, Memphis, TN (United States)

    2015-11-15

    Inflammatory pseudotumor is a generic term used to designate a heterogeneous group of inflammatory mass-forming lesions histologically characterized by myofibroblastic proliferation with chronic inflammatory infiltrate. Inflammatory pseudotumor is multifactorial in etiology and generally benign, but it is often mistaken for malignancy given its aggressive appearance. It can occur throughout the body and is seen in all age groups. Inflammatory pseudotumor has been described in the literature by many organ-specific names, resulting in confusion. Recently within this generic category of inflammatory pseudotumor, inflammatory myofibroblastic tumor has emerged as a distinct entity and is now recognized as a fibroblastic/myofibroblastic neoplasm with intermediate biological potential and occurring mostly in children. We present interesting pediatric cases of inflammatory myofibroblastic tumors given this entity's tendency to occur in children. Familiarity and knowledge of the imaging features of inflammatory pseudotumor can help in making an accurate diagnosis, thereby avoiding unnecessary radical surgery. (orig.)

  10. Fibroblast growth factor-2 regulates human cardiac myofibroblast-mediated extracellular matrix remodeling

    OpenAIRE

    Svystonyuk, Daniyil A; Ngu, Janet MC; Mewhort, Holly EM; Lipon, Brodie D; Teng, Guoqi; Guzzardi, David G; Malik, Getanshu; Belke, Darrell D.; Fedak, Paul WM

    2015-01-01

    Background Tissue fibrosis and chamber remodeling is a hallmark of the failing heart and the final common pathway for heart failure of diverse etiologies. Sustained elevation of pro-fibrotic cytokine transforming growth factor-beta1 (TGFβ1) induces cardiac myofibroblast-mediated fibrosis and progressive structural tissue remodeling. Objectives We examined the effects of low molecular weight fibroblast growth factor (LMW-FGF-2) on human cardiac myofibroblast-mediated extracellular matrix (ECM)...

  11. Regulation of Myofibroblast Differentiation by Poly(ADP-Ribose) Polymerase 1

    OpenAIRE

    Hu, Biao; Wu, Zhe; Hergert, Polla; Henke, Craig A.; Bitterman, Peter B.; Phan, Sem H.

    2013-01-01

    Poly(ADP-ribosyl)ation (PARylation) is a post-translational protein modification effected by enzymes belonging to the poly(ADP-ribose) polymerase (PARP) superfamily, mainly by PARP-1. The key acceptors of poly(ADP-ribose) include PARP-1 itself, histones, DNA repair proteins, and transcription factors. Because many of these factors are involved in the regulation of myofibroblast differentiation, we examined the role of PARylation on myofibroblast differentiation. Overexpression of PARP-1 with ...

  12. Ecological niche of plant pathogens

    Directory of Open Access Journals (Sweden)

    Ecaterina Fodor

    2011-02-01

    Full Text Available Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in niche modeling of disease spread, but few attempts were made to construct a theoretical frame for the ecological niche of pathogens. The paper is a review of the knowledge accumulated during last decades in the niche theory of pathogens and proposes an ecological approach in research. It quest for new control methods in what concerns forest plant pathogens, with a special emphasis on fungi like organisms of the genus Phytophthora. Species of Phytophthora are the most successful plant pathogens of the moment, affecting forest and agricultural systems worldwide, many of them being invasive alien organisms in many ecosystems. The hyperspace of their ecological niche is defined by hosts, environment and human interference, as main axes. To select most important variables within the hyperspace, is important for the understanding of the complex role of pathogens in the ecosystems as well as for control programs. Biotic relationships within ecosystem of host-pathogen couple are depicted by ecological network and specific metrics attached to this. The star shaped network is characterized by few high degree nodes, by short path lengths and relatively low connectivity, premises for a rapid disturbance spread.

  13. Ecological niche of plant pathogens

    Directory of Open Access Journals (Sweden)

    Ecaterina Fodor

    2011-06-01

    Full Text Available Disease ecology is a new approach to the understanding of the spread and dynamics of pathogens in natural and man-made environments. Defining and describing the ecological niche of the pathogens is one of the major tasks for ecological theory, as well as for practitioners preoccupied with the control and forecasting of established and emerging diseases. Niche theory has been periodically revised, not including in an explicit way the pathogens. However, many progresses have been achieved in niche modeling of disease spread, but few attempts were made to construct a theoretical frame for the ecological niche of pathogens. The paper is a review of the knowledge accumulated during last decades in the niche theory of pathogens and proposes an ecological approach in research. It quest for new control methods in what concerns forest plant pathogens, with a special emphasis on fungi like organisms of the genus Phytophthora. Species of Phytophthora are the most successful plant pathogens of the moment, affecting forest and agricultural systems worldwide, many of them being invasive alien organisms in many ecosystems. The hyperspace of their ecological niche is defined by hosts, environment and human interference, as main axes. To select most important variables within the hyperspace, is important the understanding of the complex role of pathogens in the ecosystems as well as for control programs. Biotic relationships within ecosystem of host-pathogen couple are depicted by ecological network and specific metrics attached to this. The star shaped network is characterized by few high degree nodes, by short path lengths and relatively low connectivity, premises for a rapid disturbance spread. 

  14. Macrophages Contribute to the Spermatogonial Niche in the Adult Testis

    Directory of Open Access Journals (Sweden)

    Tony DeFalco

    2015-08-01

    Full Text Available The testis produces sperm throughout the male reproductive lifespan by balancing self-renewal and differentiation of spermatogonial stem cells (SSCs. Part of the SSC niche is thought to lie outside the seminiferous tubules of the testis; however, specific interstitial components of the niche that regulate spermatogonial divisions and differentiation remain undefined. We identified distinct populations of testicular macrophages, one of which lies on the surface of seminiferous tubules, in close apposition to areas of tubules enriched for undifferentiated spermatogonia. These macrophages express spermatogonial proliferation- and differentiation-inducing factors, such as colony-stimulating factor 1 (CSF1 and enzymes involved in retinoic acid (RA biosynthesis. We show that transient depletion of macrophages leads to a disruption in spermatogonial differentiation. These findings reveal an unexpected role for macrophages in the spermatogonial niche in the testis and raise the possibility that macrophages play previously unappreciated roles in stem/progenitor cell regulation in other tissues.

  15. A NICHE FOR ISOTOPIC ECOLOGY

    Science.gov (United States)

    Fifty years ago, GE Hutchinson defined the ecological niche as a hypervolume in n-dimensional space with environmental variables as axes. Ecologists have recently developed renewed interest in the concept, and technological advances now allow us to use stable isotope analyses to ...

  16. The niche construction perspective: a critical appraisal

    OpenAIRE

    Scott-Phillips, Thomas C.; Laland, Kevin N.; Shuker, David M.; Dickins, Thomas E.; West, Stuart A.

    2014-01-01

    Niche construction refers to the activities of organisms that bring about changes in their environments, many of which are evolutionarily and ecologically consequential. Advocates of niche construction theory (NCT) believe that standard evolutionary theory fails to recognize the full importance of niche construction, and consequently propose a novel view of evolution, in which niche construction and its legacy over time (ecological inheritance) are described as evolutionary processes, equival...

  17. The niche construction perspective: a critical appraisal.

    OpenAIRE

    Scott-Phillips, Thomas C.; Laland, Kevin N.; Shuker, David M.; Dickins, Thomas E.; West, Stuart A.

    2014-01-01

    Niche construction refers to the activities of organisms that bring about changes in their environments, many of which are evolutionarily and ecologically consequential. Advocates of niche construction theory (NCT) believe that standard evolutionary theory fails to recognize the full importance of niche construction, and consequently propose a novel view of evolution, in which niche construction and its legacy over time (ecological inheritance) are described as evolutionary processes, equival...

  18. Maxillary Sinus Inflammatory Myofibroblastic Tumors: A Review and Case Report

    Directory of Open Access Journals (Sweden)

    Chase C. Hansen

    2015-01-01

    Full Text Available An inflammatory myofibroblastic tumor (IMT is an immunohistochemically diverse entity demonstrating neoplastic and nonneoplastic qualities. Although IMTs can arise in any area of the body, lesions arising in certain sites, namely, the nasal cavity, paranasal sinuses, and pterygopalatine fossa, demonstrate a heightened neoplastic and invasive potential. Despite case specific complete tumor regression and disease remission in response to pharmacotherapeutics, a subset of IMTs remain resistant to all forms of therapy. We present such a case, a 34-year-old female patient, with a highly resistant, maxillary sinus IMT. Her refractory, ALK-1 negative IMT has not responded well to novel therapies reported in current literature. This case suggests the role of zonal expressivity within a single lesion as a probable mechanism for its highly resistant nature and should promote determination of each IMT’s cytogenetic profile to provide more effective targeted therapy. Paper includes a literature review of all maxillary sinus IMTs from 1985 to 2014 along with their immunohistochemical staining, treatments, and outcomes.

  19. Targeting the molecular and cellular interactions of the bone marrow niche in immunologic disease.

    Science.gov (United States)

    Brozowski, Jaime M; Billard, Matthew J; Tarrant, Teresa K

    2014-02-01

    Recent investigations have expanded our knowledge of the regulatory bone marrow (BM) niche, which is critical in maintaining and directing hematopoietic stem cell (HSC) self-renewal and differentiation. Osteoblasts, mesenchymal stem cells (MSCs), and CXCL12-abundant reticular (CAR) cells are niche components in close association with HSCs and have been more clearly defined in immune cell function and homeostasis. Importantly, cellular inhabitants of the BM niche signal through G protein-coupled surface receptors (GPCRs) for various appropriate immune functions. In this article, recent literature on BM niche inhabitants (HSCs, osteoblasts, MSCs, CAR cells) and their GPCR mechanistic interactions are reviewed for better understanding of the BM cells involved in immune development, immunologic disease, and current immune reconstitution therapies. PMID:24408534

  20. Microengineered in vitro model of cardiac fibrosis through modulating myofibroblast mechanotransduction.

    Science.gov (United States)

    Zhao, Hui; Li, Xiaokang; Zhao, Shan; Zeng, Yang; Zhao, Long; Ding, Haiyan; Sun, Wei; Du, Yanan

    2014-12-01

    Cardiac fibrosis greatly impairs normal heart function post infarction and there is no effective anti-fibrotic drug developed at present. The current therapies for cardiac infarction mainly take effect by eliminating occlusion in coronary artery by thrombolysis drugs, vascular stent grafting or heart bypass operation, which are capable to provide sufficient blood flow for intact myocardium yet showed subtle efficacy in ameliorating fibrosis condition. The advances of in vitro cell/tissue models open new avenues for drug assessment due to the low cost, good controllability and availability as well as the convenience for operation as compared to the animal models. To our knowledge, no proper biomimetic in vitro cardiac fibrosis model has been reported yet. Here we engineered an in vitro cardiac fibrosis model using heart-derived fibroblasts, and the fibrogenesis was recapitulated by patterning the substrate rigidity which mimicked the mechanical heterogeneity of myocardium post-infarction. Various biomarkers for cardiac fibrosis were assayed to validate the biomimicry of the engineered platform. Subsequent addition of Rho-associated protein kinase (ROCK) pathway inhibitor reduced the ratio of myofibroblasts, indicating the feasibility of applying this platform in screening anti-fibrosis drugs. PMID:25378063

  1. Microengineered in vitro model of cardiac fibrosis through modulating myofibroblast mechanotransduction

    International Nuclear Information System (INIS)

    Cardiac fibrosis greatly impairs normal heart function post infarction and there is no effective anti-fibrotic drug developed at present. The current therapies for cardiac infarction mainly take effect by eliminating occlusion in coronary artery by thrombolysis drugs, vascular stent grafting or heart bypass operation, which are capable to provide sufficient blood flow for intact myocardium yet showed subtle efficacy in ameliorating fibrosis condition. The advances of in vitro cell/tissue models open new avenues for drug assessment due to the low cost, good controllability and availability as well as the convenience for operation as compared to the animal models. To our knowledge, no proper biomimetic in vitro cardiac fibrosis model has been reported yet. Here we engineered an in vitro cardiac fibrosis model using heart-derived fibroblasts, and the fibrogenesis was recapitulated by patterning the substrate rigidity which mimicked the mechanical heterogeneity of myocardium post-infarction. Various biomarkers for cardiac fibrosis were assayed to validate the biomimicry of the engineered platform. Subsequent addition of Rho-associated protein kinase (ROCK) pathway inhibitor reduced the ratio of myofibroblasts, indicating the feasibility of applying this platform in screening anti-fibrosis drugs. (paper)

  2. Niche energy markets in rural areas

    International Nuclear Information System (INIS)

    The objective of this project is the development of a standard methodology for integrating non-food crops in rural areas with niche energy markets. This has involved a number of steps including (i) identification of 3 niche markets for energy crops which are of common interest to the partners, (ii) application of the standard costing methodology to investigate these three niche markets and (iii) comparison of the results from this work in three workshops (one for each market). Three tightly defined niche markets were identified; these were chosen following an examination of the national energy marekts in each of the partners countries (Ireland, Germany, Netherlands, UK, Greece and Portugal). This paper gives an overview of the national energy markets which were examined. The three niche markets are introduced and the reasons for their selection given. The application of the methodology to each of the niche markets is presented along with the conclusions of the partners regarding the niche markets. (Author)

  3. Evolution of climate niches in European mammals?

    Science.gov (United States)

    Dormann, Carsten F; Gruber, Bernd; Winter, Marten; Herrmann, Dirk

    2010-04-23

    Our ability to predict consequences of climate change is severely impaired by the lack of knowledge on the ability of species to adapt to changing environmental conditions. We used distribution data for 140 mammal species in Europe, together with data on climate, land cover and topography, to derive a statistical description of their realized climate niche. We then compared climate niche overlap of pairs of species, selected on the basis of phylogenetic information. In contrast to expectations, related species were not similar in their climate niche. Rather, even species pairs that had a common ancestor less than 1 Ma already display very high climate niche distances. We interpret our finding as a strong interspecific competitive constraint on the realized niche, rather than a rapid evolution of the fundamental niche. If correct, our results imply a very limited usefulness of climate niche models for the prediction of future mammal distributions. PMID:19828492

  4. Soft tissue fibroblasts from well healing and chronic human wounds show different rates of myofibroblasts in vitro.

    Science.gov (United States)

    Schwarz, Florian; Jennewein, Martina; Bubel, Monika; Holstein, Joerg H; Pohlemann, Tim; Oberringer, Martin

    2013-02-01

    Due to an increasing life expectancy in western countries, chronic wound treatment will be an emerging challenge in the next decades. Because therapies are improving slowly appropriate diagnostic tools enabling the early prediction of the healing success remain to be developed. We used a well-established in vitro assay in combination with the analysis of 27 cytokines to discriminate between fibroblasts from chronic (n = 6) and well healing (n = 8) human wounds. Proliferation and migration of the cells as well as their response to hypoxia and their behaviour in co-culture with microvascular endothelial cells were analyzed. Myofibroblast differentiation, a time-limited essential process of regular wound healing, was also quantified. Besides weaker proliferation and migration significantly higher rates of myofibroblasts were detected in chronic wounds. With respect to the cytokine release, there was a clear trend within the group of chronic wound fibroblasts, which were releasing interferon-γ, monocyte chemotactic protein-1, granulocyte-macrophage colony stimulating factor and basic fibroblast growth factor in higher amounts than fibroblasts from healing wounds. Although the overall response of both groups of fibroblasts to hypoxia and to the contact with endothelial cells was similar, especially chronic wound fibroblasts seemed to benefit from the endothelial interaction during hypoxia and displayed better migration characteristics. The study shows (1) that the assay can identify specific features of fibroblasts derived from different human wounds and (2) that wound fibroblasts are varying in their response to the chosen parameters. Thus, current therapeutic approaches and individual healing prediction might benefit from this assay. PMID:23065295

  5. Redox Signaling as a Therapeutic Target to Inhibit Myofibroblast Activation in Degenerative Fibrotic Disease

    Directory of Open Access Journals (Sweden)

    Natalie Sampson

    2014-01-01

    Full Text Available Degenerative fibrotic diseases encompass numerous systemic and organ-specific disorders. Despite their associated significant morbidity and mortality, there is currently no effective antifibrotic treatment. Fibrosis is characterized by the development and persistence of myofibroblasts, whose unregulated deposition of extracellular matrix components disrupts signaling cascades and normal tissue architecture leading to organ failure and death. The profibrotic cytokine transforming growth factor beta (TGFβ is considered the foremost inducer of fibrosis, driving myofibroblast differentiation in diverse tissues. This review summarizes recent in vitro and in vivo data demonstrating that TGFβ-induced myofibroblast differentiation is driven by a prooxidant shift in redox homeostasis. Elevated NADPH oxidase 4 (NOX4-derived hydrogen peroxide (H2O2 supported by concomitant decreases in nitric oxide (NO signaling and reactive oxygen species scavengers are central factors in the molecular pathogenesis of fibrosis in numerous tissues and organs. Moreover, complex interplay between NOX4-derived H2O2 and NO signaling regulates myofibroblast differentiation. Restoring redox homeostasis via antioxidants or NOX4 inactivation as well as by enhancing NO signaling via activation of soluble guanylyl cyclases or inhibition of phosphodiesterases can inhibit and reverse myofibroblast differentiation. Thus, dysregulated redox signaling represents a potential therapeutic target for the treatment of wide variety of different degenerative fibrotic disorders.

  6. Childhood Fibroblastic and Myofibroblastic Tumors: A Multicenter Documentation and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Ayper KAÇAR

    2012-01-01

    Full Text Available Objective: In this study, we aimed to give a documentation of 37 cases of childhood fibroblastic/myofibroblastic tumors retrieved from the archives of 6 reference centers in Ankara along with a comprehensive review on the subject.Material and Method: A retrospective archive search was carried out for the period between 2006-2010 in 6 reference centers in Ankara covering patients with ages ranging between 0-18 years. All the tumors categorized under fibroblastic and myofibroblastic group according to World Health Organization criteria were collected.Results: The study comprised 407 soft tissue tumors in total. Fibroblastic/myofibroblastic tumors constituted 9,1 % (37 cases of these tumors. According to histopathology; 16 cases were categorized as fibromatosis, 8 cases as inflammatory myofibroblastic tumor, 6 cases as infantile fibrous hamartoma, 3 cases as nodular fasciitis and 2 cases as infantile myofibroblastic tumor/myofibromatosis and 1 case as cranial fasciitis. The only malignant case was an infantile fibrosarcoma.Conclusion: Infantile fibrosarcoma was lower than reported series and a male predominance was noted. The low incidence of newly described entities as well suggests that these tumors may have been unrecognized.

  7. Niche market analysis: healthy nutrition

    OpenAIRE

    Chlivényiová, Eva

    2012-01-01

    The purpose of this Master's Thesis is to consider preferences of the consumers on the market of healthy nutrition and trends on this market. The Thesis analyzes if the niche on the market of healthy nutrition really exists and tries to predict future development of the healthy nutrition through the found out facts. The topic of this Master's Thesis was chosen because healthy lifestyle represents a hot topic for many discussions. This Thesis includes theoretical and analytical parts. Importan...

  8. Antiapoptotic McI-1 is critical for the survival and niche-filling capacity of Foxp3+ regulatory T cells

    OpenAIRE

    Pierson, W.; Cauwe, B.; Policheni, A; Schlenner, SM; Franckaert, D; Berges, J; Humblet-Baron, S.; Schönefeldt, S; Herold, MJ; Hildeman, D; Strasser, A; Bouillet, P; Lu, LF; Matthys, P; Freitas, AA

    2013-01-01

    Foxp3+ regulatory T (T reg) cells are a crucial immunosuppressive population of CD4+ T cells, yet the homeostatic processes and survival programs that maintain the T reg cell pool are poorly understood. Here we report that peripheral T reg cells markedly alter their proliferative and apoptotic rates to rapidly restore numerical deficit through an interleukin 2-dependent and costimulation-dependent process. By contrast, excess T reg cells are removed by attrition, dependent on the Bim-initiate...

  9. p62 Is Required for Stem Cell/Progenitor Retention through Inhibition of IKK/NF-κB/Ccl4 Signaling at the Bone Marrow Macrophage-Osteoblast Niche

    Directory of Open Access Journals (Sweden)

    Kyung Hee Chang

    2014-12-01

    Full Text Available In the bone marrow (BM, hematopoietic progenitors (HPs reside in specific anatomical niches near osteoblasts (Obs, macrophages (MΦs, and other cells forming the BM microenvironment. A connection between immunosurveillance and traffic of HP has been demonstrated, but the regulatory signals that instruct the immune regulation of HP circulation are unknown. We discovered that the BM microenvironment deficiency of p62, an autophagy regulator and signal organizer, results in loss of autophagic repression of macrophage contact-dependent activation of Ob NF-κB signaling. Consequently, Ob p62-deficient mice lose bone, Ob Ccl4 expression, and HP chemotaxis toward Cxcl12, resulting in egress of short-term hematopoietic stem cells and myeloid progenitors. Finally, Ccl4 expression and myeloid progenitor egress are reversed by deficiency of the p62 PB1-binding partner Nbr1. A functional “MΦ-Ob niche” is required for myeloid progenitor/short-term stem cell retention, in which Ob p62 is required to maintain NF-κB signaling repression, osteogenesis, and BM progenitor retention.

  10. Wnt/β-catenin signaling in bone marrow niche.

    Science.gov (United States)

    Ahmadzadeh, Ahmad; Norozi, Fatemeh; Shahrabi, Saeid; Shahjahani, Mohammad; Saki, Najmaldin

    2016-02-01

    The bone marrow (BM) niche is a specific physiological environment for hematopoietic and non-hematopoietic stem cells (HSCs). Several signaling pathways (including Wnt/β-catenin) regulate various aspects of stem cell growth, function and death in the BM niche. In addition, the canonical Wnt pathway is crucial for directing self-renewal and differentiation as important mechanisms in many types of stem cells. We review the role of the Wnt/β-catenin pathway in the BM niche and its importance in stem cells. Relevant literature was identified by a PubMed search (1997-2014) of English-language literature by using the following keywords: BM niche, Wnt/β-catenin signaling, osteoblast, osteoclast and bone disease. The Wnt/β-catenin pathway regulates the stability of the β-catenin proto-oncogene. The stabilized β-catenin then translocates to the nucleus, forming a β-catenin-TCF/LEF complex regulating the transcription of specific target genes. Stem cells require β-catenin to mediate their response to Wnt signaling for maintenance and transition from the pluripotent state during embryogenesis. In adult stem cells, Wnt signaling functions at various hierarchical levels to contribute to the specification of the diverse tissues. Aberrant Wnt/β-catenin signaling and its downstream transcriptional regulators are observed in several malignant stem cells and human cancers. Because Wnt signaling can maintain stem cells and cancer cells, the ability to modulate the Wnt pathway either positively or negatively may be of therapeutic relevance. The controlled activation of Wnt signaling might allow us to enhance stem and progenitor cell activity when regeneration is needed. PMID:26475718

  11. Dermatan sulfate reduces monocyte chemoattractant protein 1 and TGF-β production, as well as macrophage recruitment and myofibroblast accumulation in mice with unilateral ureteral obstruction

    Directory of Open Access Journals (Sweden)

    C.L.R. Belmiro

    2011-07-01

    Full Text Available Selectins play an essential role in most inflammatory reactions, mediating the initial leukocyte-rolling event on activated endothelium. Heparin and dermatan sulfate (DS bind and block P- and L-selectin function in vitro. Recently, we reported that subcutaneous administration of DS inhibits colon inflammation in rats by reducing macrophage and T-cell recruitment and macrophage activation. In the present study, we examined the effect of porcine intestinal mucosa DS on renal inflammation and fibrosis in mice after unilateral ureteral obstruction (UUO. Twenty-four adult male Swiss mice weighing 20-25 g were divided into 4 groups: group C (N = 6 was not subjected to any surgical manipulation; group SH (N = 6 was subjected to surgical manipulation but without ureter ligation; group UUO (N = 6 was subjected to unilateral ureteral obstruction and received no treatment; group UUO plus DS (N = 6 was subjected to UUO and received DS (4 mg/kg subcutaneously daily for 14 days. An immunoblot study was also performed for TGF-β. Collagen (stained area ~3700 µm², MCP-1 (stained area ~1700 µm², TGF-β (stained area ~13% of total area, macrophage (number of cells ~40, and myofibroblast (stained area ~1900 µm² levels were significantly (P < 0.05 higher in the UUO group compared to control. DS treatment significantly (P < 0.05 reduced the content of collagen (stained area ~700 µm², MCP-1 (stained area ~160 µm² and TGF-β (stained area ~5% of total area, in addition to myofibroblast (stained area ~190 µm² and macrophage (number of cells ~32 accumulation in the obstructed kidney. Overall, these results indicate that DS attenuates kidney inflammation by reducing macrophage recruitment, myofibroblast population and fibrosis in mice submitted to UUO.

  12. c-MYB in the mouse incisor and hair follicle stem cell niches and surrounding tissues - correlation with proliferation and apoptosis

    Czech Academy of Sciences Publication Activity Database

    Veselá, Barbora; Švandová, Eva; Šmarda, J.; Hampl, A.; Matalová, Eva

    Lipsko : German Society for Stem Cell Research, 2012. 113-114. [Annual Congress of theGerman Society for Stem Cell Research /7./. 29.11.2012-30.11.2012, Lipsko] R&D Projects: GA ČR GAP304/11/1418 Institutional support: RVO:67985904 Keywords : apoptosis Subject RIV: EA - Cell Biology

  13. Increased fibroblast telomerase expression precedes myofibroblast α-smooth muscle actin expression in idiopathic pulmonary fibrosis

    Directory of Open Access Journals (Sweden)

    Daniel Reis Waisberg

    2012-09-01

    Full Text Available OBJECTIVE: This study sought to identify the relationship between fibroblast telomerase expression, myofibroblasts, and telomerase-mediated regulatory signals in idiopathic pulmonary fibrosis. METHODS: Thirty-four surgical lung biopsies, which had been obtained from patients with idiopathic pulmonary fibrosis and histologically classified as usual interstitial pneumonia, were examined. Immunohistochemistry was used to evaluate fibroblast telomerase expression, myofibroblast α-smooth muscle actin expression and the tissue expression of inter leu kin-4, transforming growth factor-β, and basic fibroblast growth factor. The point-counting technique was used to quantify the expression of these markers in unaffected, collapsed, mural fibrosis, and honeycombing areas. The results were correlated to patient survival. RESULTS: Fibroblast telomerase expression and basic fibroblast growth factor tissue expression were higher in collapsed areas, whereas myofibroblast expression and interleukine-4 tissue expression were higher in areas of mural fibrosis. Transforming growth factor-β expression was higher in collapsed, mural fibrosis and honeycombing areas in comparison to unaffected areas. Positive correlations were found between basic fibroblast growth factor tissue expression and fibroblast telomerase expression and between interleukin-4 tissue expression and myofibroblast α-smooth muscle actin expression. Negative correlations were observed between interleukin-4 expression and basic fibroblast growth factor tissue expression in areas of mural fibrosis. Myofibroblast α-smooth muscle actin expression and interleukin-4 tissue expression in areas of mural fibrosis were negatively associated with patient survival. CONCLUSION: Fibroblast telomerase expression is higher in areas of early remodeling in lung tissues demonstrating typical interstitial pneumonia, whereas myofibroblast α-smooth muscle actin expression predominates in areas of late remodeling

  14. Congenital peribronchial myofibroblastic tumor: prenatal imaging clues to differentiate from other fetal chest lesions

    Energy Technology Data Exchange (ETDEWEB)

    Calvo-Garcia, Maria A.; Bitters, Constance; Kline-Fath, Beth M. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, MLC 5031, Cincinnati, OH (United States); Lim, Foong-Yen [Cincinnati Children' s Hospital Medical Center, Department of Pediatric Surgery and Fetal Care Center of Cincinnati, Cincinnati, OH (United States); Stanek, Jerzy [Cincinnati Children' s Hospital Medical Center, Department of Pathology, Cincinnati, OH (United States)

    2014-04-15

    We present a prenatal case of congenital peribronchial myofibroblastic tumor referred as a congenital pulmonary airway malformation (CPAM) with hydrops and polyhydramnios at 30 weeks' gestational age. US and fetal MRI findings did not fit with the referral diagnosis, raising the possibility of intrinsic lung tumor. Fetal hydrops worsened and the baby was successfully delivered by ex utero intrapartum treatment (EXIT) to resection at 31 weeks' gestational age. To the best of our knowledge, this is a unique case of congenital peribronchial myofibroblastic tumor that underwent comprehensive prenatal evaluation and EXIT procedure with good outcome. (orig.)

  15. Congenital peribronchial myofibroblastic tumor: prenatal imaging clues to differentiate from other fetal chest lesions

    International Nuclear Information System (INIS)

    We present a prenatal case of congenital peribronchial myofibroblastic tumor referred as a congenital pulmonary airway malformation (CPAM) with hydrops and polyhydramnios at 30 weeks' gestational age. US and fetal MRI findings did not fit with the referral diagnosis, raising the possibility of intrinsic lung tumor. Fetal hydrops worsened and the baby was successfully delivered by ex utero intrapartum treatment (EXIT) to resection at 31 weeks' gestational age. To the best of our knowledge, this is a unique case of congenital peribronchial myofibroblastic tumor that underwent comprehensive prenatal evaluation and EXIT procedure with good outcome. (orig.)

  16. Inflammatory myofibroblastic tumour of the liver in a child: CT and MR findings

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Bo Yoon; Kim, Woo Sun; Cheon, Jung-Eun; Kim, In-One; Yeon, Kyung Mo [Department of Radiology, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-744 (Korea); Institute of Radiation Medicine, SNUMRC (Seoul National University Medical Research Center), Seoul (Korea); Clinical Research Institute, Seoul National University Hospital, Seoul (Korea); Kim, Chong Jai [Department of Pathology, Seoul National University College of Medicine, Seoul (Korea)

    2003-01-01

    Inflammatory myofibroblastic tumour of the liver is a rare disease in children and is characterized by an inflammatory mass of uncertain aetiology which simulates a true neoplasm, often resulting in a diagnostic dilemma. We report a pathologically proven case of inflammatory myofibroblastic tumour of the liver in a 14-month-old boy with jaundice. CT and MRI showed an ill-defined, homogeneously enhancing mass located in the hilar portion of the liver with biliary obstruction. He underwent percutaneous transhepatic biliary drainage to relieve obstructive jaundice, followed by lobectomy and, finally, liver transplantation. (orig.)

  17. Spatial distributions of niche-constructing populations

    Directory of Open Access Journals (Sweden)

    Xiaozhuo Han

    2015-12-01

    Full Text Available Niche construction theory regards organisms not only as the object of natural selection but also an active subject that can change their own selective pressure through eco-evolutionary feedbacks. Through reviewing the existing works on the theoretical models of niche construction, here we present the progress made on how niche construction influences genetic structure of spatially structured populations and the spatial-temporal dynamics of metapopulations, with special focuses on mathematical models and simulation methods. The majority of results confirmed that niche construction can significantly alter the evolutionary trajectories of structured populations. Organism-environmental interactions induced by niche construction can have profound influence on the dynamics, competition and diversity of metapopulations. It can affect fine-scale spatially distribution of species and spatial heterogeneity of the environment. We further propose a few research directions with potentials, such as applying adaptive dynamics or spatial game theory to explore the effect of niche construction on phenotypic evolution and diversification.

  18. Exploring dynamics and strategies of niche protection

    OpenAIRE

    Boon, W.P.C.; Moors, Ellen H M; Meijer, Albert J.

    2014-01-01

    This paper focuses on the processes and strategies of advocates and opponents in creating, maintaining and/or contesting the protective spaces in which 'urgently needed' but 'risky' pharmaceutical innovations are managed. Drawing on transition literature and recent work on niche protection, this paper adds to the conceptualisation and empirical grounding of niche protection by studying the dynamics of protection, in particular the different phases of niche development. Moreover, the links bet...

  19. Human niche construction in interdisciplinary focus

    OpenAIRE

    Kendal, Jeremy; Tehrani, Jamshid J.; Odling-Smee, John

    2011-01-01

    Niche construction is an endogenous causal process in evolution, reciprocal to the causal process of natural selection. It works by adding ecological inheritance, comprising the inheritance of natural selection pressures previously modified by niche construction, to genetic inheritance in evolution. Human niche construction modifies selection pressures in environments in ways that affect both human evolution, and the evolution of other species. Human ecological inheritance is exceptionally po...

  20. Tenascin C upregulates interleukin-6 expression in human cardiac myofibroblasts via toll-like receptor 4

    Science.gov (United States)

    Maqbool, Azhar; Spary, Emma J; Manfield, Iain W; Ruhmann, Michaela; Zuliani-Alvarez, Lorena; Gamboa-Esteves, Filomena O; Porter, Karen E; Drinkhill, Mark J; Midwood, Kim S; Turner, Neil A

    2016-01-01

    AIM: To investigate the effect of Tenascin C (TNC) on the expression of pro-inflammatory cytokines and matrix metalloproteinases in human cardiac myofibroblasts (CMF). METHODS: CMF were isolated and cultured from patients undergoing coronary artery bypass grafting. Cultured cells were treated with either TNC (0.1 μmol/L, 24 h) or a recombinant protein corresponding to different domains of the TNC protein; fibrinogen-like globe (FBG) and fibronectin type III-like repeats (TNIII 5-7) (both 1 μmol/L, 24 h). The expression of the pro-inflammatory cytokines; interleukin (IL)-6, IL-1β, TNFα and the matrix metalloproteinases; MMPs (MMP1, 2, 3, 9, 10, MT1-MMP) was assessed using real time RT-PCR and western blot analysis. RESULTS: TNC increased both IL-6 and MMP3 (P < 0.01) mRNA levels in cultured human CMF but had no significant effect on the other markers studied. The increase in IL-6 mRNA expression was mirrored by an increase in protein secretion as assessed by enzyme-linked immunosorbant assay (P < 0.01). Treating CMF with the recombinant protein FBG increased IL-6 mRNA and protein (P < 0.01) whereas the recombinant protein TNIII 5-7 had no effect. Neither FBG nor TNIII 5-7 had any significant effect on MMP3 expression. The expression of toll-like receptor 4 (TLR4) in human CMF was confirmed by real time RT-PCR, western blot and immunohistochemistry. Pre-incubation of cells with TLR4 neutralising antisera attenuated the effect of both TNC and FBG on IL-6 mRNA and protein expression. CONCLUSION: TNC up-regulates IL-6 expression in human CMF, an effect mediated through the FBG domain of TNC and via the TLR4 receptor. PMID:27231521

  1. Modelling the regenerative niche: a major challenge in biomaterials research.

    Science.gov (United States)

    Kirkpatrick, C James

    2015-12-01

    By definition, biomaterials are developed for clinical application. In the field of regenerative medicine their principal function is to play a significant, and, if possible, an instructive role in tissue healing. In the last analysis the latter involves targeting the 'regenerative niche'. The present paper will address the problem of simulating this niche in the laboratory and adopts a life science approach involving the harnessing of heterotypic cellular communication to achieve this, that is, the ability of cells of different types to mutually influence cellular functions. Thus, co-culture systems using human cells are the methodological focus and will concern four exemplary fields of regeneration, namely, bone, soft tissue, lower respiratory tract and airway regeneration. The working hypothesis underlying this approach is that in vitro models of higher complexity will be more clinically relevant than simple monolayer cultures of transformed cell lines in testing innovative strategies with biomaterials for regeneration. PMID:26816650

  2. Structural ECM components in the premetastatic and metastatic niche.

    Science.gov (United States)

    Høye, Anette M; Erler, Janine T

    2016-06-01

    The aim of this review is to give an overview of the extracellular matrix (ECM) components that are important for creating structural changes in the premetastatic and metastatic niche. The successful arrival and survival of cancer cells that have left the primary tumor and colonized distant sites depends on the new microenvironment they encounter. The primary tumor itself releases factors into the circulation that travel to distant organs and then initiate structural changes, both non-enzymatic and enzymatic, to create a favorable niche for the disseminating tumor cells. Therapeutic strategies aimed at targeting cell-ECM interactions may well be one of the best viable approaches to combat metastasis and thus improve patient care. PMID:27053524

  3. Niche-tracking migrants and niche-switching residents: evolution of climatic niches in New World warblers (Parulidae).

    Science.gov (United States)

    Gómez, Camila; Tenorio, Elkin A; Montoya, Paola; Cadena, Carlos Daniel

    2016-02-10

    Differences in life-history traits between tropical and temperate lineages are often attributed to differences in their climatic niche dynamics. For example, the more frequent appearance of migratory behaviour in temperate-breeding species than in species originally breeding in the tropics is believed to have resulted partly from tropical climatic stability and niche conservatism constraining tropical species from shifting their ranges. However, little is known about the patterns and processes underlying climatic niche evolution in migrant and resident animals. We evaluated the evolution of overlap in climatic niches between seasons and its relationship to migratory behaviour in the Parulidae, a family of New World passerine birds. We used ordination methods to measure seasonal niche overlap and niche breadth of 54 resident and 49 migrant species and used phylogenetic comparative methods to assess patterns of climatic niche evolution. We found that despite travelling thousands of kilometres, migrants tracked climatic conditions across the year to a greater extent than tropical residents. Migrant species had wider niches than resident species, although residents as a group occupied a wider climatic space and niches of migrants and residents overlapped extensively. Neither breeding latitude nor migratory distance explained variation among species in climatic niche overlap between seasons. Our findings support the notion that tropical species have narrower niches than temperate-breeders, but does not necessarily constrain their ability to shift or expand their geographical ranges and become migratory. Overall, the tropics may have been historically less likely to experience the suite of components that generate strong selection pressures for the evolution of migratory behaviour. PMID:26865303

  4. Stitch the niche - a practical philosophy and visual schematic for the niche concept

    NARCIS (Netherlands)

    McInerny, Greg J.; Etienne, Rampal S.

    2012-01-01

    By over-focusing on precise definitions, ecology has produced a confused idea of the niche concept. This, our second paper, develops a practical philosophy for the niche that approaches the concept at the correct level of abstraction. We deconstruct the niche into effect and response components and

  5. Ditch the niche - is the niche a useful concept in ecology or species distribution modelling?

    NARCIS (Netherlands)

    McInerny, Greg J.; Etienne, Rampal S.

    2012-01-01

    In this first of three papers we examine the use of niche concepts in ecology and especially in species distribution modelling (SDM). This paper deliberately focuses on the lack of clarity found in the term niche. Because its meanings are so diverse, the term niche tends to create confusion and requ

  6. Mapping of potential neurogenic niche in the human temporal lobe

    Directory of Open Access Journals (Sweden)

    Adriano Barreto Nogueira

    2014-10-01

    Full Text Available The subgranular zone (SGZ of the dentate gyrus and the subventricular zone (SVZ are known neurogenic niches in adult mammals. Nonetheless, the existence of neurogenic niches in adult humans is controversial. We hypothesized that mapping neurogenic niches in the human temporal lobe could clarify this issue. Neurogenic niches and neurogenesis were investigated in 28 temporal lobes via immunostaining for nestin and doublecortin (DCX, respectively. Nestin was observed in a continuous layer formed by the SVZ, the subpial zone of the medial temporal lobe and the SGZ, terminating in the subiculum. In the subiculum, remarkable DCX expression was observed through the principal efferent pathway of the hippocampus to the fimbria. A possible explanation for the results is that the SVZ, the subpial zone of the medial temporal lobe and the SGZ form a unit containing neural stem cells that differentiate into neurons in the subiculum. Curiously, the area previously identified as the human rostral migratory stream may in truth be the fornix, which contains axons that originate in the subiculum. This study suggests that neurogenesis may occur in an orchestrated manner in a broad area of the human temporal lobe.

  7. WOX5–IAA17 feedback circuit-mediated cellular auxin response is crucial for the patterning of root stem cell niches in Arabidopsis

    OpenAIRE

    Tian, Huiyu; Wabnik, Krzysztof; Niu, Tiantian; Li, Hanbing; Yu, Qianqian; Pollmann, Stephan; Vanneste, Steffen; Govaerts, Willy; Rolčík, Jakub; Geisler, Markus; Friml, Jiří; Ding, Zhaojun

    2014-01-01

    In plants, the patterning of stem cell-enriched meristems requires a graded auxin response maximum that emerges from the concerted action of polar auxin transport, auxin biosynthesis, auxin metabolism, and cellular auxin response machinery. However, mechanisms underlying this auxin response maximum-mediated root stem cell maintenance are not fully understood. Here, we present unexpected evidence that WUSCHEL-RELATED HOMEOBOX 5 (WOX5) transcription factor modulates expression of auxin biosynth...

  8. Cytoarchitecture and Ultrastructure of Neural Stem Cell Niches and Neurogenic Complexes Maintaining Adult Neurogenesis in the Olfactory Midbrain of Spiny Lobsters, Panulirus argus

    OpenAIRE

    Schmidt, Manfred; Derby, Charles D.

    2011-01-01

    New interneurons are continuously generated in small proliferation zones within neuronal somata clusters in the olfactory deutocerebrum of adult decapod crustaceans. Each proliferation zone is connected to a clump of cells containing one neural stem cell (i.e., adult neuroblast), thus forming a “neurogenic complex.” Here we provide a detailed analysis of the cytoarchitecture of neurogenic complexes in adult spiny lobsters, Panulirus argus, based on transmission electron microscopy and labelin...

  9. Fractal heterogeneity in minimal matrix models of scars modulates stiff-niche stem-cell responses via nuclear exit of a mechanorepressor

    Science.gov (United States)

    Dingal, P. C. Dave P.; Bradshaw, Andrew M.; Cho, Sangkyun; Raab, Matthew; Buxboim, Amnon; Swift, Joe; Discher, Dennis E.

    2015-09-01

    Scarring is a long-lasting problem in higher animals, and reductionist approaches could aid in developing treatments. Here, we show that copolymerization of collagen I with polyacrylamide produces minimal matrix models of scars (MMMS), in which fractal-fibre bundles segregate heterogeneously to the hydrogel subsurface. Matrix stiffens locally--as in scars--while allowing separate control over adhesive-ligand density. The MMMS elicits scar-like phenotypes from mesenchymal stem cells (MSCs): cells spread and polarize quickly, increasing nucleoskeletal lamin-A yet expressing the `scar marker' smooth muscle actin (SMA) more slowly. Surprisingly, expression responses to MMMS exhibit less cell-to-cell noise than homogeneously stiff gels. Such differences from bulk-average responses arise because a strong SMA repressor, NKX2.5, slowly exits the nucleus on rigid matrices. NKX2.5 overexpression overrides rigid phenotypes, inhibiting SMA and cell spreading, whereas cytoplasm-localized NKX2.5 mutants degrade in well-spread cells. MSCs thus form a `mechanical memory' of rigidity by progressively suppressing NKX2.5, thereby elevating SMA in a scar-like state.

  10. Myofibroblast Expression in Skin Wounds Is Enhanced by Collagen III Suppression

    Directory of Open Access Journals (Sweden)

    Mohammed M. Al-Qattan

    2015-01-01

    Full Text Available Generally speaking, the excessive expression of myofibroblasts is associated with excessive collagen production. One exception is seen in patients and animal models of Ehlers-Danlos syndrome type IV in which the COL3A1 gene mutation results in reduced collagen III but with concurrent increased myofibroblast expression. This paradox has not been examined with the use of external drugs/modalities to prevent hypertrophic scars. In this paper, we injected the rabbit ear wound model of hypertrophic scarring with two doses of a protein called nAG, which is known to reduce collagen expression and to suppress hypertrophic scarring in that animal model. The higher nAG dose was associated with significantly less collagen III expression and concurrent higher degree of myofibroblast expression. We concluded that collagen III content of the extracellular matrix may have a direct or an indirect effect on myofibroblast differentiation. However, further research is required to investigate the pathogenesis of this paradoxical phenomenon.

  11. Molecular analysis of the TGF-beta controlled gene expression program in chicken embryo dermal myofibroblasts

    Czech Academy of Sciences Publication Activity Database

    Kosla, Jan; Dvořák, Michal; Čermák, Vladimír

    2013-01-01

    Roč. 513, č. 1 (2013), s. 90-100. ISSN 0378-1119 R&D Projects: GA AV ČR KAN200520801 Institutional support: RVO:68378050 Keywords : microarray * myofibroblastic phenotype * inhibition of TGF-beta signaling Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.082, year: 2013

  12. Effective myofibroblast dedifferentiation by concomitant inhibition of TGF-beta signaling and perturbation of MAPK signaling

    Czech Academy of Sciences Publication Activity Database

    Kosla, Jan; Dvořáková, Marta; Dvořák, Michal; Čermák, Vladimír

    2013-01-01

    Roč. 92, č. 12 (2013), s. 363-373. ISSN 0171-9335 R&D Projects: GA AV ČR KAN200520801 Institutional support: RVO:68378050 Keywords : PDGFB * Ha-Ras(G12V) * EGR4 * TGF-beta * Myofibroblast * FOXG1 * Microarrays Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.699, year: 2013

  13. Inhibition of PI3K prevents the proliferation and differentiation of human lung fibroblasts into myofibroblasts: the role of class I P110 isoforms.

    Directory of Open Access Journals (Sweden)

    Enrico Conte

    Full Text Available Idiopathic pulmonary fibrosis (IPF is a progressive fibroproliferative disease characterized by an accumulation of fibroblasts and myofibroblasts in the alveolar wall. Even though the pathogenesis of this fatal disorder remains unclear, transforming growth factor-β (TGF-β-induced differentiation and proliferation of myofibroblasts is recognized as a primary event. The molecular pathways involved in TGF-β signalling are generally Smad-dependent yet Smad-independent pathways, including phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt, have been recently proposed. In this research we established ex-vivo cultures of human lung fibroblasts and we investigated the role of the PI3K/Akt pathway in two critical stages of the fibrotic process induced by TGF-β: fibroblast proliferation and differentiation into myofibroblasts. Here we show that the pan-inhibitor of PI3Ks LY294002 is able to abrogate the TGF-β-induced increase in cell proliferation, in α- smooth muscle actin expression and in collagen production besides inhibiting Akt phosphorylation, thus demonstrating the centrality of the PI3K/Akt pathway in lung fibroblast proliferation and differentiation. Moreover, for the first time we show that PI3K p110δ and p110γ are functionally expressed in human lung fibroblasts, in addition to the ubiquitously expressed p110α and β. Finally, results obtained with both selective inhibitors and gene knocking-down experiments demonstrate a major role of p110γ and p110α in both TGF-β-induced fibroblast proliferation and differentiation. This finding suggests that specific PI3K isoforms can be pharmacological targets in IPF.

  14. Target Article with Commentaries: Developmental Niche Construction

    Science.gov (United States)

    Flynn, Emma G.; Laland, Kevin N.; Kendal, Rachel L.; Kendal, Jeremy R.

    2013-01-01

    Niche construction is the modification of components of the environment through an organism's activities. Humans modify their environments mainly through ontogenetic and cultural processes, and it is this reliance on learning, plasticity and culture that lends human niche construction a special potency. In this paper we aim to facilitate…

  15. EUBrazilOpenBio - Niche modelling services

    OpenAIRE

    Rebello, Vinod; De Giovanni, Renato; Candela, Leonardo

    2012-01-01

    This report concerns Ecological Niche Modelling - also known as environmental niche modelling - as used in the EUBrazilOpenBio Project to provide, through the aggregation of various computational and data technologies, a coherent and integrated research environment to be used by scientists and external applications, particularly from the area of biodiversity.

  16. Prostanoid induces premetastatic niche in regional lymph nodes

    OpenAIRE

    Ogawa, Fumihiro; AMANO, HIDEKI; Eshima, Koji; Ito, Yoshiya; Matsui, Yoshio; Hosono, Kanako; Kitasato, Hidero; Iyoda, Akira; Iwabuchi, Kazuya; Kumagai, Yuji; Satoh, Yukitoshi; Narumiya, Shuh; Majima, Masataka

    2014-01-01

    The lymphatic system is an important route for cancer dissemination, and lymph node metastasis (LNM) serves as a critical prognostic determinant in cancer patients. We investigated the contribution of COX-2–derived prostaglandin E2 (PGE2) in the formation of a premetastatic niche and LNM. A murine model of Lewis lung carcinoma (LLC) cell metastasis revealed that COX-2 is expressed in DCs from the early stage in the lymph node subcapsular regions, and COX-2 inhibition markedly suppressed media...

  17. Niche-specific cognitive strategies

    DEFF Research Database (Denmark)

    Hulgard, K.; Ratcliffe, J. M.

    2014-01-01

    that bats made their decisions based on information acquired through echolocation. Previous studies have shown that bat species that eat mainly nectar and fruit rely heavily on spatial memory, reflecting the relative consistency of distribution of fruit and nectar compared with insects. Our results......Related species with different diets are predicted to rely on different cognitive strategies: those best suited for locating available and appropriate foods. Here we tested two predictions of the niche-specific cognitive strategies hypothesis in bats, which suggests that predatory species should...... rely more on object memory than on spatial memory for finding food and that the opposite is true of frugivorous and nectivorous species. Specifically, we predicted that: (1) predatory bats would readily learn to associate shapes with palatable prey and (2) once bats had made such associations, these...

  18. In vitro evaluation of the cytotoxicity and modulation of mechanisms associated with inflammation induced by perfluorooctanesulfonate and perfluorooctanoic acid in human colon myofibroblasts CCD-18Co.

    Science.gov (United States)

    Giménez-Bastida, Juan Antonio; Surma, Magdalena; Zieliński, Henryk

    2015-10-01

    Perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) are the most notable members of an emerging class of persistent organic pollutants (POPs), poly- and perfluoroalkyl acids (PFASs). In this study, the CCD-18Co myofibroblasts were selected as a cell model to investigate the cytotoxic effects of PFOS and PFOA. The aim was to perform an in vitro evaluation of the ability of these compounds to induce cytotoxicity and modulate mechanisms associated with inflammation as measured by (i) colon fibroblasts viability, (ii) colon fibroblasts proliferation, and (iii) IL-6 production. The data provided in this study suggest that PFOS and PFOA can have cytotoxic potential and modulate processes associated with intestinal inflammation such as myofibroblasts proliferation and IL-6 production at concentrations similar to those detected in vivo. Our results also highlight the influence of culture serum concentration in cytotoxic in vitro studies, which should be considered in future toxicity studies involving PFOS and PFOA. The results contribute to a better knowledge of the effects of PFOS and PFOA in human cells, a phenomenon still not fully examined. PMID:26142696

  19. WOX5-1AA17 Feedback Circuit-Mediated CellularAuxin Response Is Crucial for the Patterning ofRoot Stem Cell Niches in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    In plants, the patterning of stem cell-enriched meristems requires a graded auxin response maximum thatemerges from the concerted action of polar auxin transport, auxin biosynthesis, auxin metabolism, and cellular auxinresponse machinery. However, mechanisms underlying this auxin response maximum-mediated root stem cell mainte-nance are not fully understood. Here, we present unexpected evidence that WUSCHEL-RELATED HOMEOBOX 5 (WOX5)transcription factor modulates expression of auxin biosynthetic genes in the quiescent center (QC) of the root and thusprovides a robust mechanism for the maintenance of auxin response maximum in the root tip. This WOX5 action is bal-anced through the activity of indole-3-acetic acid 17 (IAA17) auxin response repressor. Our combined genetic, cell biol-ogy, and computational modeling studies revealed a previously uncharacterized feedback loop linking WOX5-mediatedauxin production to IAA17-dependent repression of auxin responses. This WOX5-1AA17 feedback circuit further assuresthe maintenance of auxin response maximum in the root tip and thereby contributes to the maintenance of distal stemcell (DSC) populations. Our experimental studies and in silico computer simulations both demonstrate that the WOX5-iAA17 feedback circuit is essential for the maintenance of auxin gradient in the root tip and the auxin-mediated root DSCdifferentiation.

  20. Regulation of microRNA expression in the neuronal stem cell niches during aging of the short-lived annual fish Nothobranchius furzeri.

    OpenAIRE

    Mario Baumgart; Alessandro Cellerino

    2014-01-01

    In the last decade, our group has intensively studied the annual fish Nothobranchius furzeri as a new experimental model in Biology specifically applied to aging research. We previously studied adult neuronal stem cells of N. furzeri in vivo and we demonstrated an age-dependent decay in adult neurogenesis. More recently we identified and quantified the expression of miRNAs in the brain of N. furzeri and we detected 165 conserved miRNAs and found that brain aging in Nothobranchius furzeri is a...

  1. Physiological and pathological role of local and immigrating colonic stem cells

    Institute of Scientific and Technical Information of China (English)

    Ferenc Sipos; Gábor Valcz; Béla Molnár

    2012-01-01

    The latest avenue of research is revealing the existence of and role for the colonic stem cells in the physiological renewal of the mucosa and in pathological circumstances where they have both positive and negative effects. In the case of human colon, different levels of stem cell compartments exist. First, the crypt epithelial stem cells, which have a role in the normal crypt epithelial cell dynamics and in colorectal carcinogenesis. Close to the crypts, the second layer of stem cells can be found; the local subepithelial stem cell niche, including the pericryptic subepithelial myofibroblasts that regulate the epithelial cell differentiation and have a crucial role in cancer progression and chronic inflammation-related fibrosis. The third level of stem cell compartment is the immigrating bone-marrow-derived stem cells, which have an important role in wound healing after severe mucosal inflammation, but are also involved in cancer invasion. This paper focuses on stem cell biology in the context of physiological and pathological processes in the human colon.

  2. The IκB kinase inhibitor ACHP strongly attenuates TGFβ1‐induced myofibroblast formation and collagen synthesis

    OpenAIRE

    Mia, Masum M.; Bank, Ruud A.

    2015-01-01

    Abstract Excessive accumulation of a collagen‐rich extracellular matrix (ECM) by myofibroblasts is a characteristic feature of fibrosis, a pathological state leading to serious organ dysfunction. Transforming growth factor beta1 (TGFβ1) is a strong inducer of myofibroblast formation and subsequent collagen production. Currently, there are no remedies for the treatment of fibrosis. Activation of the nuclear factor kappa B (NF‐κB) pathway by phosphorylating IκB with the enzyme IκB kinase (IKK) ...

  3. The United States pork niche market phenomenon.

    Science.gov (United States)

    Honeyman, M S; Pirog, R S; Huber, G H; Lammers, P J; Hermann, J R

    2006-08-01

    After the broad industrialization of the US pork industry, there has been a development of niche markets for export and domestic pork; that is, there is a pork niche market phenomenon. The US pork niche market phenomenon is characterized, and 2 of the major markets are explained in detail. With the Midwest's tradition of a diversified family-based agriculture and record low hog prices of the late 1990s, the conditions were conducive for this phenomenon to develop. Pork niche markets utilize various sales methods including Internet sales, local abattoir sales, direct marketing, farmer networks, and targeting to organized groups. In 2003, there were approximately 35 to 40 active pork niche marketing efforts in Iowa. The Berkshire breed is an example of a swine breed that has had a recent resurgence because of niche markets. Berkshire pork is known for tenderness and excellent quality. Berkshire registrations have increased 4-fold in the last 10 yr. One of the larger niche marketers of "natural pork" is Niman Ranch Pork, which has more than 400 farmer-producers and processes about 2,500 pigs weekly. Many US consumers of pork are interested in issues concerning the environment, food safety, pig welfare, and pig farm ownership and structure. These consumers may be willing to pay more for pork from farmers who are also concerned about these issues. Small- and medium-sized swine farmers are active in pork niche markets. Niche markets claim product differentiation by superior or unique product quality and social attributes. Quality attributes include certain swine breeds, and meat quality, freshness, taste or flavor, and tenderness. Social or credence attributes often are claimed and include freedom from antibiotics and growth promotants; local family farm production; natural, organic, outdoor, or bedded rearing; humane rearing; known origin; environmentally friendly production; and the absence of animal by-products in the feed. Niche pork markets and alternative swine

  4. Platelets drive smooth muscle metaplasia and fibrogenesis in endometriosis through epithelial-mesenchymal transition and fibroblast-to-myofibroblast transdifferentiation.

    Science.gov (United States)

    Zhang, Qi; Duan, Jie; Liu, Xishi; Guo, Sun-Wei

    2016-06-15

    Smooth muscle metaplasia (SMM) and fibrotic tissues are frequently seen in endometriotic lesions, yet the mechanisms underlying their formation are poorly understood. In this study, we investigated the roles of activated platelets in driving epithelial-mesenchymal transition (EMT) and fibroblast-to-myofibroblast transdifferentiation (FMT) in endometriosis. Through in vitro experimentations, we found that activated platelets, through the release of TGF-β1 and the induction of TGF-β/Smad signaling pathway, promoted EMT and FMT in endometriosis, resulting in increased cell contractility, collagen production, and ultimately to fibrosis. TGF-β blockade reversed these processes. Prolonged exposure of endometriotic stromal cells to activated platelets induced increased expression of α-SMA as well as markers of differentiated smooth muscle cells. Consequently, endometriotic lesions and their microenvironment contain all the necessary molecular machinery to promote SMM and fibrogenesis. Our results suggest that endometriotic lesions are wounds that undergo repeated injury and healing, highlighting the importance of platelets in the development of endometriosis. PMID:26992563

  5. CD133 identifies perivascular niches in grade II-IV astrocytomas

    DEFF Research Database (Denmark)

    Christensen, Karina; Schrøder, Henrik; Kristensen, Bjarne

    2008-01-01

    expression of CD133 in paraffin sections was analysed using morphometry. In all grades, CD133 was expressed on tumour and endothelial cells. Tumour cells were found in perivascular niches, as dispersed single cells and in pseudopalisade formations around necrosis. There was no correlation between the mean...

  6. Niching method using clustering crowding

    Institute of Scientific and Technical Information of China (English)

    GUO Guan-qi; GUI Wei-hua; WU Min; YU Shou-yi

    2005-01-01

    This study analyzes drift phenomena of deterministic crowding and probabilistic crowding by using equivalence class model and expectation proportion equations. It is proved that the replacement errors of deterministic crowding cause the population converging to a single individual, thus resulting in premature stagnation or losing optional optima. And probabilistic crowding can maintain equilibrium multiple subpopulations as the population size is adequate large. An improved niching method using clustering crowding is proposed. By analyzing topology of fitness landscape using hill valley function and extending the search space for similarity analysis, clustering crowding determines the locality of search space more accurately, thus greatly decreasing replacement errors of crowding. The integration of deterministic and probabilistic replacement increases the capacity of both parallel local hill climbing and maintaining multiple subpopulations. The experimental results optimizing various multimodal functions show that,the performances of clustering crowding, such as the number of effective peaks maintained, average peak ratio and global optimum ratio are uniformly superior to those of the evolutionary algorithms using fitness sharing, simple deterministic crowding and probabilistic crowding.

  7. CROSS DRIFT ALCOVE/NICHE UTILITIES ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    S. Goodin

    1999-07-08

    The purpose of this analysis is to provide the design basis and general arrangement requirements of the non-potable water, waste water, compressed air and ventilation (post excavation) utilities required in support of the Cross Drift alcoves and niches.

  8. Ecological niches of open ocean phytoplankton taxa

    DEFF Research Database (Denmark)

    Brun, Philipp Georg; Vogt, Meike; Payne, Mark;

    2015-01-01

    We characterize the realized ecological niches of 133 phytoplankton taxa in the open ocean based on observations from the MAREDAT initiative and a statistical species distribution model (MaxEnt). The models find that the physical conditions (mixed layer depth, temperature, light) govern large...... conditions in the open ocean. Our estimates of the realized niches roughly match the predictions of Reynolds' C-S-R model for the global ocean, namely that taxa classified as nutrient stress tolerant have niches at lower nutrient and higher irradiance conditions than light stress tolerant taxa. Yet......-scale patterns in phytoplankton biogeography over nutrient availability. Strongest differences in the realized niche centers were found between diatoms and coccolithophores. Diatoms (87 species) occur in habitats with significantly lower temperatures, light intensity and salinity, with deeper mixed layers...

  9. Niche models tell half the story

    DEFF Research Database (Denmark)

    Swab, Rebecca Marie; Regan, Helen M.; Keith, David A.;

    2012-01-01

    Aim  While niche models are typically used to assess the vulnerability of species to climate change, they have been criticized for their limited assessment of threats other than climate change. We attempt to evaluate this limitation by combining niche models with life-history models to investigate...... processes might interact. Location  Australian sclerophyll woodland and heathland. Methods  The study species is Leucopogon setiger, an obligate seeding fire-prone shrub. A spatially explicit stochastic matrix model was constructed for this species and linked with a dynamic niche model and fire risk...... providing a greater understanding of the impacts of global change than would be gained by niche models alone. Further investigations of this type could elucidate how particular bioecological factors can affect certain types of species under global change....

  10. CROSS DRIFT ALCOVE/NICHE UTILITIES ANALYSIS

    International Nuclear Information System (INIS)

    The purpose of this analysis is to provide the design basis and general arrangement requirements of the non-potable water, waste water, compressed air and ventilation (post excavation) utilities required in support of the Cross Drift alcoves and niches

  11. Inflammatory myofibroblastic bladder tumor in a patient with wolf-hirschhorn syndrome.

    Science.gov (United States)

    Marte, Antonio; Indolfi, Paolo; Ficociello, Carmine; Russo, Daniela; Oreste, Matilde; Bottigliero, Gaetano; Gualdiero, Giovanna; Barone, Ciro; Vigliar, Elena; Indolfi, Cristiana; Casale, Fiorina

    2013-01-01

    Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm described in several tissues and organs including genitourinary system, lung, head, and neck. The etiology of IMT is contentious, and whether it is a postinflammatory process or a true neoplasm remains controversial. To our knowledge, we report the first reported case of IMT of urinary bladder in a pediatric patient with Wolf-Hirschhorn (WHS). We also review the literature about patients with associated neoplasia. PMID:24024066

  12. Lithium Attenuates TGF-β1-Induced Fibroblasts to Myofibroblasts Transition in Bronchial Fibroblasts Derived from Asthmatic Patients

    Directory of Open Access Journals (Sweden)

    Marta Michalik

    2012-01-01

    Full Text Available Bronchial asthma is a chronic disorder accompanied by phenotypic transitions of bronchial epithelial cells, smooth muscle cells, and fibroblasts. Human bronchial fibroblasts (HBFs derived from patients with diagnosed asthma display predestination towards TGF-β-induced phenotypic switches. Since the interference between TGF-β and GSK-3β signaling contributes to pathophysiology of chronic lung diseases, we investigated the effect of lithium, a nonspecific GSK-3β inhibitor, on TGF-β1-induced fibroblast to myofibroblast transition (FMT in HBF and found that the inhibition of GSK-3β attenuates TGF-β1-induced FMT in HBF populations derived from asthmatic but not healthy donors. Cytoplasmically sequestrated β-catenin, abundant in TGF-β1/LiCl-stimulated asthmatic HBFs, most likely interacts with and inhibits the nuclear accumulation and signal transduction of Smad proteins. These data indicate that the specific cellular context determines FMT-related responses of HBFs to factors interfering with the TGF-β signaling pathway. They may also provide a mechanistic explanation for epidemiological data revealing coincidental remission of asthmatic syndromes and their recurrence upon the discontinuation of lithium therapy in certain psychiatric diseases.

  13. Inflammatory myofibroblastic tumor causing unexplained anemia in a toddler: a case report

    Directory of Open Access Journals (Sweden)

    Jameel Abdullah

    2011-02-01

    Full Text Available Abstract Introduction Inflammatory myofibroblastic tumor is a very rare benign tumor in children that mimics malignant tumors in its aggressiveness locally and by the possibility of recurrence after surgical resection, and causing anemia of chronic disease, which is a decrease in hemoglobin 1 to 2 g/dL below normal level in a patient with chronic illness. Case presentation A 32-month-old boy from Libya presented with microcytic hypochromic anemia. He had been treated in three countries and five centers without response to medical therapy. He was investigated at our center and found to have a mass in the colon causing intermittent intussusception and bleeding. He was treated surgically, and his condition improved dramatically. The pathology report proved a diagnosis of inflammatory myofibroblastic tumor. Conclusion We report a case of an unusual tumor of the gastrointestinal tract causing chronic anemia not responding to medical treatment, and discuss the characteristics of inflammatory myofibroblastic tumor. In our case, we stress the involvement of a multidisciplinary team in treating such a patient who presents with common symptoms and signs but in whom there has been no response to any of the measures and treatment protocols.

  14. Unusual case of pancreatic inflammatory myofibroblastic tumor associated with spontaneous splenic rupture

    Directory of Open Access Journals (Sweden)

    Hassan Fadi K

    2010-11-01

    Full Text Available Abstract Background Spontaneous splenic rupture considered a relatively rare but life threatening. The three commonest causes of spontaneous splenic rupture are malignant hematological diseases, viral infections and local inflammatory and neoplastic disorders. We describe a unique and unusual case of inflammatory myofibroblastic tumor of the tail of pancreas presented with massively enlarged spleen and spontaneous splenic rupture. Case presentation A 19 years old male patient with no significant past medical history presented to emergency room with abdominal pain and fatigue. Massively enlarged spleen was detected. Hypotension and rapid reduction of hemoglobin level necessitated urgent laparatomy. About 1.75 liters of blood were found in abdominal cavity. A large tumor arising from the tail of pancreas and local rupture of an enlarged spleen adjacent to the tumor were detected. Distal pancreatectomy and splenectomy were performed. To our knowledge, we report the first case of massively enlarged spleen that was complicated with spontaneous splenic rupture as a result of splenic congestion due to mechanical obstruction caused by an inflammatory myofibroblastic tumor of the tail of pancreas. A review of the literature is also presented. Conclusion Inflammatory myofibroblastic tumor of the tail of pancreas should be included in the differential diagnosis of the etiological causes of massively enlarged spleen and spontaneous splenic rupture.

  15. Counteracting effect of TRPC1-associated Ca2+ influx on TNF-α-induced COX-2-dependent prostaglandin E2 production in human colonic myofibroblasts.

    Science.gov (United States)

    Hai, Lin; Kawarabayashi, Yasuhiro; Imai, Yuko; Honda, Akira; Inoue, Ryuji

    2011-08-01

    TNF-α-NF-κB signaling plays a central role in inflammation, apoptosis, and neoplasia. One major consequence of this signaling in the gut is increased production of prostaglandin E(2) (PGE(2)) via cyclooxygenase-2 (COX-2) induction in myofibroblasts, which has been reported to be dependent on Ca(2+). In this study, we explored a potential role of canonical transient receptor potential (TRPC) proteins in this Ca(2+)-mediated signaling using a human colonic myofibroblast cell line CCD-18Co. In CCD-18Co cell, treatment with TNF-α greatly enhanced Ca(2+) influx induced by store depletion along with increased cell-surface expression of TRPC1 protein (but not of the other TRPC isoforms) and induction of a Gd(3+)-sensitive nonselective cationic conductance. Selective inhibition of TRPC1 expression by small interfering RNA (siRNA) or functionally effective TRPC1 antibody targeting the near-pore region of TRPC1 (T1E3) antagonized the enhancement of store-dependent Ca(2+) influx by TNF-α, whereas potentiated TNF-α induced PGE(2) production. Overexpression of TRPC1 in CCD-18Co produced opposite consequences. Inhibitors of NF-κB (curcumin, SN-50) attenuated TNF-α-induced enhancement of TRPC1 expression, store-dependent Ca(2+) influx, and COX-2-dependent PGE(2) production. In contrast, inhibition of calcineurin-nuclear factor of activated T-cell proteins (NFAT) signaling by FK506 or NFAT Activation Inhibitor III enhanced the PGE(2) production without affecting TRPC1 expression and the Ca(2+) influx. Finally, the suppression of store-dependent Ca(2+) influx by T1E3 antibody or siRNA knockdown significantly facilitated TNF-α-induced NF-κB nuclear translocation. In aggregate, these results strongly suggest that, in colonic myofibroblasts, NF-κB and NFAT serve as important positive and negative transcriptional regulators of TNF-α-induced COX-2-dependent PGE(2) production, respectively, at the downstream of TRPC1-associated Ca(2+) influx. PMID:21546578

  16. Epigenetic regulation of stemness maintenance in theneurogenic niches

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    In the adult mouse brain, the subventricular zonelining the lateral ventricles and the subgranular zonein the dentate gyrus of the hippocampus are twozones that contain neural stem cells (NSCs) withthe capacity to give rise to neurons and glia duringthe entire life of the animal. Spatial and temporalregulation of gene expression in the NSCs populationis established and maintained by the coordinatedinteraction between transcription factors and epigeneticregulators which control stem cell fate. Epigenetic mechanismsare heritable alterations in genome functionthat do not involve changes in DNA sequence itself butthat modulate gene expression, acting as mediatorsbetween the environment and the genome. At themolecular level, those epigenetic mechanisms comprisechemical modifications of DNA such as methylation,hydroxymethylation and histone modifications neededfor the maintenance of NSC identity. Genomic imprintingis another normal epigenetic process leading to parentalspecificexpression of a gene, known to be implicatedin the control of gene dosage in the neurogenic niches.The generation of induced pluripotent stem cells fromNSCs by expression of defined transcription factors,provide key insights into fundamental principles ofstem cell biology. Epigenetic modifications can alsooccur during reprogramming of NSCs to pluripotencyand a better understanding of this process will helpto elucidate the mechanisms required for stem cellmaintenance. This review takes advantage of recentstudies from the epigenetic field to report knowledgeregarding the mechanisms of stemness maintenance ofneural stem cells in the neurogenic niches.

  17. Why do niches develop in Caesarean uterine scars? Hypotheses on the aetiology of niche development

    Science.gov (United States)

    Vervoort, A.J.M.W.; Uittenbogaard, L.B.; Hehenkamp, W.J.K.; Brölmann, H.A.M.; Mol, B.W.J.; Huirne, J.A.F.

    2015-01-01

    Caesarean section (CS) results in the occurrence of the phenomenon ‘niche’. A ‘niche’ describes the presence of a hypoechoic area within the myometrium of the lower uterine segment, reflecting a discontinuation of the myometrium at the site of a previous CS. Using gel or saline instillation sonohysterography, a niche is identified in the scar in more than half of the women who had had a CS, most with the uterus closed in one single layer, without closure of the peritoneum. An incompletely healed scar is a long-term complication of the CS and is associated with more gynaecological symptoms than is commonly acknowledged. Approximately 30% of women with a niche report spotting at 6–12 months after their CS. Other reported symptoms in women with a niche are dysmenorrhoea, chronic pelvic pain and dyspareunia. Given the association between a niche and gynaecological symptoms, obstetric complications and potentially with subfertility, it is important to elucidate the aetiology of niche development after CS in order to develop preventive strategies. Based on current published data and our observations during sonographic, hysteroscopic and laparoscopic evaluations of niches we postulate some hypotheses on niche development. Possible factors that could play a role in niche development include a very low incision through cervical tissue, inadequate suturing technique during closure of the uterine scar, surgical interventions that increase adhesion formation or patient-related factors that impair wound healing or increase inflammation or adhesion formation. PMID:26409016

  18. Telocytes Contribute as Cell Progenitors and Differentiation Inductors in Tissue Regeneration.

    Science.gov (United States)

    Vannucchi, Maria-Giuliana; Bani, Daniele; Faussone-Pellegrini, Maria-Simonetta

    2016-01-01

    According to recent literature data, a peculiar connective tissue cell, called telocyte (TC), is present in almost all organs. Furthermore, TC subtypes, often coexisting in the same organ, but having different immunohistochemical and ultrastructural characteristics, have been demonstrated. Characteristically, TC, by connecting to each other and/or with other cell types, build three-dimensional networks. In the latter case they form a mixed network. TC, therefore, may be part of an integrated system to maintain tissue/organ function. Several roles have been proposed for the TC some of which support the importance of these cells in the differentiation and regenerative processes. Indeed, TC might behave as inductors/regulators of differentiation during morphogenesis due to their ability to release molecular signals and to construct the scaffold necessary for the parenchymal organization. In the adulthood, TC may be considered mesenchymal stromal cells able to differentiate in different cell types, such as the interstitial cells of Cajal, the resident myofibroblasts and the fibroblasts. Furthermore, the TC might be essential for the survival, proliferation, differentiation, maturation and guidance of the parenchymal stem cells located in the niches of several organs and, eventually, stimulate and sustain the regenerative processes. PMID:26018235

  19. Classification and comparison of niche services for developing strategy of medical tourism in Asian countries.

    Science.gov (United States)

    Chen, Hung-chi; Kuo, Hsin-chih; Chung, Kuo-Piao; Chang, Sophia; Su, Syi; Yang, Ming-chin

    2010-01-01

    , and (3) banned procedures that are not allowed legally in home countries of foreign patients, such as stem cell therapy. In establishing a niche service, a high-quality, nonmedical segment should be integrated as well. PMID:20718315

  20. Keratocyte apoptosis and not myofibroblast differentiation mark the graft/host interface at early time-points post-DSAEK in a cat model.

    Directory of Open Access Journals (Sweden)

    Adam J Weis

    Full Text Available PURPOSE: To evaluate myofibroblast differentiation as an etiology of haze at the graft-host interface in a cat model of Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK. METHODS: DSAEK was performed on 10 eyes of 5 adult domestic short-hair cats. In vivo corneal imaging with slit lamp, confocal, and optical coherence tomography (OCT were performed twice weekly. Cats were sacrificed and corneas harvested 4 hours, and 2, 4, 6, and 9 days post-DSAEK. Corneal sections were stained with the TUNEL method and immunohistochemistry was performed for α-smooth muscle actin (α-SMA and fibronectin with DAPI counterstain. RESULTS: At all in vivo imaging time-points, corneal OCT revealed an increase in backscatter of light and confocal imaging revealed an acellular zone at the graft-host interface. At all post-mortem time-points, immunohistochemistry revealed a complete absence of α-SMA staining at the graft-host interface. At 4 hours, extracellular fibronectin staining was identified along the graft-host interface and both fibronectin and TUNEL assay were positive within adjacent cells extending into the host stroma. By day 2, fibronectin and TUNEL staining diminished and a distinct acellular zone was present in the region of previously TUNEL-positive cells. CONCLUSIONS: OCT imaging consistently showed increased reflectivity at the graft-host interface in cat corneas in the days post-DSAEK. This was not associated with myofibroblast differentiation at the graft-host interface, but rather with apoptosis and the development of a subsequent acellular zone. The roles of extracellular matrix changes and keratocyte cell death and repopulation should be investigated further as potential contributors to the interface optical changes.

  1. Fibroblastic and myofibroblastic tumors of the head and neck: Comprehensive imaging-based review with pathologic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Hourani, Roula, E-mail: rh64@aub.edu.lb [Department of Diagnostic Radiology, American University of Beirut Medical Center, Beirut (Lebanon); Taslakian, Bedros, E-mail: bt05@aub.edu.lb [Department of Diagnostic Radiology, American University of Beirut Medical Center, Beirut (Lebanon); Shabb, Nina S., E-mail: ns04@aub.edu.lb [Department of Pathology and Laboratory Medicine, American University of Beirut Medical Center, Beirut (Lebanon); Nassar, Lara, E-mail: ln07@aub.edu.lb [Department of Diagnostic Radiology, American University of Beirut Medical Center, Beirut (Lebanon); Hourani, Mukbil H., E-mail: mh17@aub.edu.lb [Department of Diagnostic Radiology, American University of Beirut Medical Center, Beirut (Lebanon); Moukarbel, Roger, E-mail: rm17@aub.edu.lb [Department of Otolaryngology – Head and Neck Surgery, American University of Beirut Medical Center, Beirut (Lebanon); Sabri, Alain, E-mail: as71@aub.edu.lb [Department of Otolaryngology – Head and Neck Surgery, American University of Beirut Medical Center, Beirut (Lebanon); Rizk, Toni, E-mail: tonirisk@hotmail.com [Department of Neurosurgery, Hôtel-Dieu de France, Saint-Joseph University, Beirut (Lebanon)

    2015-02-15

    Highlights: • Almost all fibroblastic tumors are evaluated with non-invasive imaging. • Radiologists should be familiar with the imaging appearance of fibroblastic tumors. • Most appropriate initial examination when fibromatosis coli suspected is ultrasound. • Most common location of ossifying fibromas is the tooth-bearing regions. - Abstract: Fibroblastic and myofibroblastic tumors of the head and neck are a heterogeneous group of disorders characterized by the proliferation of fibroblasts, myofibroblasts, or both. These tumors may be further subclassified on the basis of their behavior as benign, intermediate with malignant potential, or malignant. There are different types of fibroblastic and myofibroblastic tumors that can involve the head and neck including desmoid-type fibromatosis, solitary fibrous tumor, myofibroma/myofibromatosis, nodular fasciitis, nasopharyngeal angiofibroma, fibrosarcoma, dermatofibrosarcoma protuberans, fibromatosis coli, inflammatory myofibroblastic tumor, ossifying fibroma, fibrous histiocytoma, nodular fasciitis, fibromyxoma, hyaline fibromatosis and fibrous hamartoma. Although the imaging characteristics of fibroblastic and myofibroblastic tumors of the head and neck are nonspecific, imaging plays a pivotal role in the noninvasive diagnosis and characterization of these tumors, providing information about the constitution of tumors, their extension and invasion of adjacent structures. Correlation with the clinical history may help limit the differential diagnosis and radiologists should be familiar with the imaging appearance of these tumors to reach an accurate diagnosis.

  2. Doctoral education in a successful ecological niche

    DEFF Research Database (Denmark)

    Christensen, Mette Krogh; Lund, Ole

    2014-01-01

    Scholarly communities are dependent on and often measured by their ability to attract and develop doctoral students. Recent literature suggests that most scholarly communities entail ecological niches in which the doctoral students learn the codes and practices of research. In this article, we...... explore the microclimate in an ecological niche of doctoral education. Based on a theoretical definition of microclimate as the emotional atmosphere that ties group members together and affects their actions, we conducted a case study that aimed to describe the key features of the microclimate in a...... successful ecological niche of doctoral education, and the ways in which the microclimate support the doctoral students’ learning. The methods we applied in the case study were based on short-term ethnographic fieldwork. The results reveal four key features of the emotional atmosphere in the microclimate...

  3. Niche Formation in the Mashup Ecosystem

    Directory of Open Access Journals (Sweden)

    Michael Weiss

    2013-05-01

    Full Text Available Mashups enable end-users to "mix and match" data and services available on the web to create applications. Their creation is supported by a complex ecosystem of i data providers who offer open APIs to users, ii users who combine APIs into mashups, and iii platforms, such as the ProgrammableWeb or Mashape, that facilitate the construction and publication of mashups. In this article, we argue that the evolution of the mashup ecosystem can be explained in terms of ecosystem niches anchored around hub or keystone APIs. The members of a niche are focused on an area of specialization (e.g., mapping applications and contribute their knowledge to the value proposition of the ecosystem as a whole. To demonstrate the formation of niches in the mashup ecosystem, we model groups of related mashups as species, and we reconstruct the evolution of mashup species through phylogenetic analysis.

  4. A practioner's view on Strategic Niche Management

    International Nuclear Information System (INIS)

    Strategic Niche Management (SNM) is a tool to support the societal introduction of radical sustainable innovations. However, it has been mainly used in retrospective to analyse historical case studies. This report discusses SNM from a practioner's perspective with the main aim to articulate questions that should be addressed for translating SNM from an ex-post to an ex-ante tool. The main conclusion is that an SNM tool should focus on the level of 'niches' rather than single projects, i.e. SNM should aim to support (program) managers who aim at orchestrating the interaction between multiple experiments

  5. The Probabilistic Niche Model Reveals the Niche Structure and Role of Body Size in a Complex Food Web

    OpenAIRE

    Richard J Williams; Ananthi Anandanadesan; Drew Purves

    2010-01-01

    The niche model has been widely used to model the structure of complex food webs, and yet the ecological meaning of the single niche dimension has not been explored. In the niche model, each species has three traits, niche position, diet position and feeding range. Here, a new probabilistic niche model, which allows the maximum likelihood set of trait values to be estimated for each species, is applied to the food web of the Benguela fishery. We also developed the allometric niche model, in w...

  6. Dental mesenchymal stem cells

    OpenAIRE

    Kaukua, Nina

    2014-01-01

    Mesenchymal stem cells have been found in various tissues and act as source for renewal and repair. The mouse incisor tooth continuously grows throughout life, implicating that there are stem cell niches constantly contributing with cells. The composition of these stem cell niches is not fully understood. Here, we show that Schwann cells on the peripheral nerves in the close proximity to the incisor tooth constitute a stem cell niche. Transgenic mouse models were used to label ...

  7. The probabilistic niche model reveals the niche structure and role of body size in a complex food web.

    Directory of Open Access Journals (Sweden)

    Richard J Williams

    Full Text Available The niche model has been widely used to model the structure of complex food webs, and yet the ecological meaning of the single niche dimension has not been explored. In the niche model, each species has three traits, niche position, diet position and feeding range. Here, a new probabilistic niche model, which allows the maximum likelihood set of trait values to be estimated for each species, is applied to the food web of the Benguela fishery. We also developed the allometric niche model, in which body size is used as the niche dimension. About 80% of the links in the empirical data are predicted by the probabilistic niche model, a significant improvement over recent models. As in the niche model, species are uniformly distributed on the niche axis. Feeding ranges are exponentially distributed, but diet positions are not uniformly distributed below the predator. Species traits are strongly correlated with body size, but the allometric niche model performs significantly worse than the probabilistic niche model. The best-fit parameter set provides a significantly better model of the structure of the Benguela food web than was previously available. The methodology allows the identification of a number of taxa that stand out as outliers either in the model's poor performance at predicting their predators or prey or in their parameter values. While important, body size alone does not explain the structure of the one-dimensional niche.

  8. Huge pelvi-abdominal malignant inflammatory myofibroblastic tumor with rapid recurrence in a 14-year-old boy

    Institute of Scientific and Technical Information of China (English)

    Chia-Hsun; Lu; Hsuan-Ying; Huang; Han-Koo; Chen; Jiin-Haur; Chuang; Shu-Hang; Ng; Sheung-Fat; Ko

    2010-01-01

    Inflammatory myofibroblastic tumor(IMT) is an uncommon benign neoplasm with locally aggressive behavior but malignant change is rare.We report an unusual case of pelvic-abdominal inflammatory myofibroblastic tumor with malignant transformation in a 14-year-old boy presenting with abdominal pain and 9 kg body weight loss in one month.Computed tomography revealed a huge pelvi-abdominal mass(30 cm),possibly originating from the pelvic extraperitoneal space,protruding into the abdomen leading to upward displace...

  9. An emerging niche market opportunity. Part I.

    Science.gov (United States)

    Pulaski, M J

    1997-01-01

    Society is split between a desire for access to quality health care and a reluctance, by some, to pay for it. Looking at this cost/access dichotomy historically enables one to recognize an emerging niche market--discriminating, affluent consumers willing to pay for better health care. PMID:10169123

  10. Development of a laboratory niche Web site.

    Science.gov (United States)

    Dimenstein, Izak B; Dimenstein, Simon I

    2013-10-01

    This technical note presents the development of a methodological laboratory niche Web site. The "Grossing Technology in Surgical Pathology" (www.grossing-technology.com) Web site is used as an example. Although common steps in creation of most Web sites are followed, there are particular requirements for structuring the template's menu on methodological laboratory Web sites. The "nested doll principle," in which one object is placed inside another, most adequately describes the methodological approach to laboratory Web site design. Fragmentation in presenting the Web site's material highlights the discrete parts of the laboratory procedure. An optimally minimal triad of components can be recommended for the creation of a laboratory niche Web site: a main set of media, a blog, and an ancillary component (host, contact, and links). The inclusion of a blog makes the Web site a dynamic forum for professional communication. By forming links and portals, cloud computing opens opportunities for connecting a niche Web site with other Web sites and professional organizations. As an additional source of information exchange, methodological laboratory niche Web sites are destined to parallel both traditional and new forms, such as books, journals, seminars, webinars, and internal educational materials. PMID:23769601

  11. Shifting Niches for Community Structure Detection

    DEFF Research Database (Denmark)

    Grappiolo, Corrado; Togelius, Julian; Yannakakis, Georgios N.

    2013-01-01

    in complete networks, this approach seems to scale badly due to solutions with the wrong number of communities dominating the population. The new algorithm is based on a niching model, where separate compartments of the population contain candidate solutions with different numbers of communities. We...

  12. ECRB ALCOVE AND NICHE GROUND SUPPORT ANALYSIS

    International Nuclear Information System (INIS)

    The purpose of the analysis is to provide design bases for Enhanced Characterization of the Repository Block (ECRB) alcove and niche ground support drawings. The objective is to evaluate the ESF Alcove Ground Support Analysis (Ref 5.1) to determine if the calculations technically bound the ECRB alcoves and to address specific differences in the conditions and constraints

  13. Adult Neurogenesis: Ultrastructure of a Neurogenic Niche and Neurovascular Relationships

    OpenAIRE

    Paula Grazielle Chaves da Silva; Jeanne L Benton; Beltz, Barbara S.; Silvana Allodi

    2012-01-01

    The first-generation precursors producing adult-born neurons in the crayfish (Procambarus clarkii) brain reside in a specialized niche located on the ventral surface of the brain. In the present work, we have explored the organization and ultrastructure of this neurogenic niche, using light-level, confocal and electron microscopic approaches. Our goals were to define characteristics of the niche microenvironment, examine the morphological relationships between the niche and the vasculature an...

  14. The influence of the pre-metastatic niche on breast cancer metastasis.

    Science.gov (United States)

    Ursini-Siegel, Josie; Siegel, Peter M

    2016-09-28

    The emergence of metastatic disease constitutes a significant life-threatening development during cancer progression. To date, intensive efforts have been focused on understanding the intrinsic properties that confer malignant potential to cancer cells, as well as the role of the primary tumour microenvironment in promoting cancer metastasis. Beyond events occurring at the primary site, the metastatic cascade is composed of numerous barriers that must be overcome in order for disseminating cancer cells to form distal metastases. The most formidable of these is the ability of cancer cells to seed and grow in a completely foreign microenvironment. Interestingly, solid malignancies often display a particular tropism for specific tissue sites. For example, breast patients with metastatic disease will often develop bone, lung, liver or brain metastases. This mini-review will explore aspects of pre-existing and induced metastatic niches and focus on how the unique composition and function of diverse niche components, within common sites of breast cancer metastasis, enable the survival and growth of disseminated cancer cells. These common supportive functions of the niche are provided by a complex array of stromal components and molecular mechanisms that are, in part, reflective of the tissue in which the metastases arise. Finally, the metastatic niche is a dynamic structure that is continually altered and sculpted by the cancer cells during progression of the metastatic lesion. PMID:26577808

  15. St. Mary's Collegiate Church, Youghal, north choir wall, tomb niche, base of niche

    OpenAIRE

    O'Donovan, Danielle

    2005-01-01

    Base of tomb niche opening, moulding from top down comprises: roll, roll, bell, roll, roll, bell, curved plinth. Very unusual Perpendicular style base, other examples can be found at Strade, Sligo Dominican, Balintubber.

  16. Functional traits, convergent evolution, and periodic tables of niches.

    Science.gov (United States)

    Winemiller, Kirk O; Fitzgerald, Daniel B; Bower, Luke M; Pianka, Eric R

    2015-08-01

    Ecology is often said to lack general theories sufficiently predictive for applications. Here, we examine the concept of a periodic table of niches and feasibility of niche classification schemes from functional trait and performance data. Niche differences and their influence on ecological patterns and processes could be revealed effectively by first performing data reduction/ordination analyses separately on matrices of trait and performance data compiled according to logical associations with five basic niche 'dimensions', or aspects: habitat, life history, trophic, defence and metabolic. Resultant patterns then are integrated to produce interpretable niche gradients, ordinations and classifications. Degree of scheme periodicity would depend on degrees of niche conservatism and convergence causing species clustering across multiple niche dimensions. We analysed a sample data set containing trait and performance data to contrast two approaches for producing niche schemes: species ordination within niche gradient space, and niche categorisation according to trait-value thresholds. Creation of niche schemes useful for advancing ecological knowledge and its applications will depend on research that produces functional trait and performance datasets directly related to niche dimensions along with criteria for data standardisation and quality. As larger databases are compiled, opportunities will emerge to explore new methods for data reduction, ordination and classification. PMID:26096695

  17. Role of Intestinal Myofibroblasts in HIV-Associated Intestinal Collagen Deposition and Immune Reconstitution following Combination Antiretroviral Therapy

    Science.gov (United States)

    Asmuth, David M; Pinchuk, Irina V; Wu, Jian; Vargas, Gracie; Chen, Xiaoli; Mann, Surinder; Albanese, Anthony; Ma, Zhong-Min; Saroufeem, Ramez; Melcher, Gregory P; Troia-Cancio, Paolo; Torok, Natalie J; Miller, Christopher J; Powell, Don W.

    2015-01-01

    Objective To investigate the potential role of mucosal intestinal myofibroblasts (IMFs) in HIV and associated fibrosis in GALT. Design Profibrotic changes within the secondary lymphoid organs and mucosa has been implicated in failed immune reconstitution following effective cART. Microbial translocation is believed to be sustaining these systemic inflammatory pathways. IMFs are non-professional antigen-presenting cells with both immunoregulatory and mesenchymal functions that are ideally positioned to respond to translocating microbial antigen. Methods Duodenal biopsies obtained from patients naïve to cART underwent trichrome staining and examined for TGF-β expression. Combined immunostaining and second harmonic generation-analysis was used to determine IMF activation and collagen deposition. Confocal microscopy was performed to examine for IMF activation and TLR4 expression. Finally, primary IMF cultures were stimulated with LPS to demonstrate expression of inflammatory biomarkers. Results The expression of the fibrosis-promoting molecule, TGF-β1, is significantly increased in duodenal biopsies from HIV patients naïve to cART and negatively correlated with subsequent peripheral CD4 recovery. The TGFβ1 increases coincided with an increase in collagen deposition in duodenal mucosa in tissue area adjacent to IMFs. We also observed that IMFs expressed TLR4 and had an activated phenotype since they were positive for fibroblast activation protein. Finally, stimulation of IMFs from HIV patients with TLR4 resulted in significantly increased expression of profibrotic molecules, TGF-β1 and IL-6. Conclusions Our data support the hypothesis that activated IMFs may be among the major cells contributing to the profibrotic changes and thus, the establishment and maintenance of systemic inflammation interfering with immune reconstitution in HIV patients. PMID:25784439

  18. Identificação do nicho de progenitores mesenquimais no fígado de embriões e fetos caninos: uma fonte de células-tronco para terapia celular Identification of mesenchymal progenitor niches from liver of embryo and fetuses of canines: a source of stem cells for cell therapy

    Directory of Open Access Journals (Sweden)

    Daniele S. Martins

    2012-12-01

    potential. This organ during the fetal period in mammals acts as a transient hematopoietic niche, being the main organ responsible for hematopoiesis in the fetus, and contribute to the formation of permanent niche in the adult bone marrow, thus can be considered a niche for mesenchymal stem cells (MSC and parents. However, little is known about the location of these cells in FF, so the present study aims to identify the niche of mesenchymal progenitors in FF and dogs in order to contribute to the techniques of cell isolation and extraction. Together was performed to verify the expression of the transcription factor Oct-3/4 of the protein and DNA polymerase delta (PCNA. For the analysis of five embryos were used and 11 canine fetuses with gestational ages ranging from 25-60 days. The results elucidated from 25 days of gestation showed the FF is bulky and composed of all the typical structures, among them the portal triad, bile ducts and hepatic artery branches. With 30 days of gestation were identified the first requirements of mesenchymal progenitors (MP at 60 days while the niches were completely formed with location similar to adult liver (AL. However, cells immunoreactives for Oct-3/4 were not identified, therefore, point out that the FL is a source of PM, presenting as an alternative for therapeutic purposes as well as for studying the developmental biology of MSC and parents.

  19. Relationship between ultrasound elastography and myofibroblast distribution in breast cancer and its clinical significance.

    Science.gov (United States)

    Hao, Yi; Guo, Xia; Ma, Binlin; Zhu, Lin; Liu, Lisha

    2016-01-01

    The study investigated the relationship between ultrasound elastography (USE) scoring and myofibroblast distribution with expression features of α-SMA +/CD34- in patients of Uyghur and Han ethnicities with breast masses in Xinjiang, China. The data was used to evaluate its clinical significance in the early diagnosis of breast cancer. A total of 300 patients with breast masses were included in the study, which involved conventional sonography and USE, with histopathologic diagnosis as the reference standard. Myofibroblast distribution was investigated by detecting the expression levels of α-SMA and CD34 in lesions using immunohistochemistry and real-time PCR. Out of 300 lesions, 185 were histologically malignant and 115 benign. The mean elasticity score for malignant lesions was significantly higher than for benign lesions. The expression level of α-SMA was elevated while the expression level of CD34 was lower in malignancies, compared with benign lesions. The expression of α-SMA was positively associated with the USE scores, while a negative relationship was observed between CD34 expression and USE scoring. The combination of USE and molecular diagnosis provides a promising modality for the early diagnosis and evaluation of the risks in particular types of breast cancer. PMID:26846996

  20. Inflammatory myofibroblastic tumor successfully treated with chemotherapy and nonsteroidals: A case report

    Institute of Scientific and Technical Information of China (English)

    Yun-Lu Tao; Zhen-Jun Wang; Jia-Gang Han; Ping Wei

    2012-01-01

    Inflammatory myofibroblastic tumor (IMT) occurring at retroperitoneal sites has rarely been reported.We report the case of a previously well 14-year-old girl with no history of abdominal disease whose past medical history and family tumor history were unremarkable.She complained of intermittent abdominal pain for one month.An abdominal mass was found on physical examination and abdominal contrast-enhanced computed tomography (CT) showed a hypodense soft mass,the size and location of which suggested a well delineated retroperitoneal tumor surrounding the superior mesenteric vessels measuring 3.3 cm x 4.5 cm x 4.5 cm with enlarged lymph nodes.The patient underwent an exploratory laparotomy followed by biopsy and was subsequently diagnosed with retroperitoneal IMT.She was successfully treated with postoperative chemotherapy and oral diclofenac sodium.Following completion of therapy the mass was no longer palpable and no longer visible on CT scanning.The use of methotrexate and cisplatin for aggressive myofibroblastic tumors is also reviewed.

  1. Study of the Logistics Enterprise Development Path based on Niche Theory

    Institute of Scientific and Technical Information of China (English)

    Sun Wenxia

    2013-01-01

    This paper refers evolutionary ecology of niche theory,analyzes logistics enterprises niche,as well as niche overlapping,niche separation,niche compression,niche expansionetc.And on this basis,this paper proposes,the development path of the logistics enterprise “co-operation,with in the horizontal,external vertical cooperation”,hoping advancing further of logisticsenterprises.

  2. Time-dependent Appearances of Myofibroblasts during the Re-pair of Contused Skeletal Muscle in Rat and Its Application for Wound Age Determination

    Institute of Scientific and Technical Information of China (English)

    YU Tian-shui; GUAN Da-wei; CHANG Lin; WANG Xu; ZHAO Rui; ZHANG Hai-dong; BAI Ru-feng

    2015-01-01

    Objective To research the relation between the time-dependent appearances of myofibroblasts during the repair of contused skeletal muscle in rat and wound age determination. Methods A total of 35 SD male rats were divided into the control and six injured groups according to wound age as fol-lows: 12 h, 1 d, 5 d, 7 d, 10 d and 14 d after injury. The appearances of myofibroblasts were detected by HE staining, immunohistochemistry and confocal laser scanning microscopy. Masson’s trichrome staining was utilized to examine collagen accumulation in the contused areas. Results Immunohistochemical stain-ing showed that α-SMA+ myofibroblasts were initially observed at 5 d post-injury. The average ratio of myofibroblasts was highest at 14 d post-injury, with all samples, ratios more than 50%. In the other five groups, the average of α-SMA positive ratios were less than 50%. The collagen stained areas in the contused zones, concomitant with myofibroblast appearance, were increasingly augmented along with ad-vances of posttraumatic interval. Conclusion The immunohistochemical detection of myofibroblasts can be applied to wound age determination. The myofibroblasts might be involved in collagen deposition during the repair of contused skeletal muscle in rat.

  3. PAR1-dependent and independent increases in COX-2 and PGE2 in human colonic myofibroblasts stimulated by thrombin.

    Science.gov (United States)

    Seymour, Michelle L; Zaidi, Nosheen F; Hollenberg, Morley D; MacNaughton, Wallace K

    2003-05-01

    Subepithelial myofibroblast-derived prostaglandin E(2) (PGE(2)) regulates epithelial chloride secretion in the intestine. Thrombin is elevated in inflammatory conditions of the bowel. Therefore, we sought to determine a role for thrombin in regulating PGE(2) synthesis by colonic myofibroblasts. Incubation of cultured CCD-18Co colonic myofibroblasts with thrombin, the proteinase-activated receptor 1 (PAR(1))-activating peptide (Cit-NH(2)), and peptides corresponding to 2 noncatalytic regions of thrombin (TP367 and TP508) for 18 h increased both cyclooxygenase (COX)-2 expression (immunocytochemistry) and PGE(2) synthesis (enzyme immunoassay). Inhibition of thrombin by D-Phe-Pro-Arg-chloromethylketone (PPACK) did not significantly reduce PGE(2) synthesis, which remained elevated compared with control. We also investigated the basic fibroblast growth factor (bFGF) dependence of thrombin-induced PGE(2) elevations. Recombinant human bFGF concentration dependently increased PGE(2) synthesis, and a bFGF neutralizing antibody inhibited PGE(2) synthesis induced by TP367 and TP508 (approximately 40%) and by thrombin (approximately 20%) (but not Cit-NH(2)). Thrombin, therefore, upregulates COX-2-derived PGE(2) synthesis by both catalytic cleavage of PAR(1) and bFGF-dependent noncatalytic activity. This presents a novel mechanism by which intestinal myofibroblasts might regulate epithelial chloride secretion. PMID:12505789

  4. LA NICHE ÉCOLOGIQUE: CONCEPTS, MODÈLES, APPLICATIONS

    OpenAIRE

    Pocheville, Arnaud

    2010-01-01

    Cette thèse est une enquête sur le concept de niche et quelques grands cadres théoriques qui y sont apparentés: la théorie de la niche et la théorie neutraliste en écologie, la théorie de la construction de niche en biologie évolutive, et la niche des cellules souches en écologie intra-organisme. Le premier chapitre retrace l'histoire du concept de niche et confronte la théorie de la niche à une théorie concurrente, la théorie neutraliste. Le concept de niche apparaît comme devant être un exp...

  5. Creatures of Norms as Uncanny Niche Constructors

    Czech Academy of Sciences Publication Activity Database

    Peregrin, Jaroslav

    London: College Publications, 2011 - (Hříbek, T.; Hvorecký, J.), s. 189-190. (Texts in Philosophy. 15). ISBN 978-1-84890-043-1. [Knowledge, Value, Evolution . Praha (CZ), 23.11.2009-25.11.2009] R&D Projects: GA ČR(CZ) GAP401/10/0146 Institutional research plan: CEZ:AV0Z90090514 Keywords : evolution * rules * gene-culture coevolution * virtual niches Subject RIV: AA - Philosophy ; Religion

  6. Mammalian niche conservation through deep time.

    Directory of Open Access Journals (Sweden)

    Larisa R G DeSantis

    Full Text Available Climate change alters species distributions, causing plants and animals to move north or to higher elevations with current warming. Bioclimatic models predict species distributions based on extant realized niches and assume niche conservation. Here, we evaluate if proxies for niches (i.e., range areas are conserved at the family level through deep time, from the Eocene to the Pleistocene. We analyze the occurrence of all mammalian families in the continental USA, calculating range area, percent range area occupied, range area rank, and range polygon centroids during each epoch. Percent range area occupied significantly increases from the Oligocene to the Miocene and again from the Pliocene to the Pleistocene; however, mammalian families maintain statistical concordance between rank orders across time. Families with greater taxonomic diversity occupy a greater percent of available range area during each epoch and net changes in taxonomic diversity are significantly positively related to changes in percent range area occupied from the Eocene to the Pleistocene. Furthermore, gains and losses in generic and species diversity are remarkably consistent with ~2.3 species gained per generic increase. Centroids demonstrate southeastern shifts from the Eocene through the Pleistocene that may correspond to major environmental events and/or climate changes during the Cenozoic. These results demonstrate range conservation at the family level and support the idea that niche conservation at higher taxonomic levels operates over deep time and may be controlled by life history traits. Furthermore, families containing megafauna and/or terminal Pleistocene extinction victims do not incur significantly greater declines in range area rank than families containing only smaller taxa and/or only survivors, from the Pliocene to Pleistocene. Collectively, these data evince the resilience of families to climate and/or environmental change in deep time, the absence of

  7. BMP signaling in the nephron progenitor niche

    OpenAIRE

    Oxburgh, Leif; Brown, Aaron C.; Fetting, Jennifer; Hill, Beth

    2011-01-01

    Bone morphogenic proteins (BMPs) play diverse roles in embryonic kidney development, regulating essential aspects of both ureteric bud and nephron development. In this review, we provide an overview of reported expression patterns and functions of BMP signaling components within the nephrogenic zone or nephron progenitor niche of the developing kidney. Reported in situ hybridization results are relatively challenging to interpret and sometimes conflicting. Comparing these with high-resolution...

  8. Sustainability of Human Ecological Niche Construction

    OpenAIRE

    Forest Isbell; Michel Loreau

    2014-01-01

    Humans influence and depend on natural systems worldwide, creating complex societal-ecological feedbacks that make it difficult to assess the long-term sustainability of contemporary human activities. We use ecological niche theory to consider the short-term (transient) and long-term (equilibrium) effects of improvements in health, agriculture, or efficiency on the abundances of humans, our plant and animal resources, and our natural enemies. We also consider special cases of our model where ...

  9. The IκB kinase inhibitor ACHP strongly attenuates TGFβ1-induced myofibroblast formation and collagen synthesis.

    Science.gov (United States)

    Mia, Masum M; Bank, Ruud A

    2015-12-01

    Excessive accumulation of a collagen-rich extracellular matrix (ECM) by myofibroblasts is a characteristic feature of fibrosis, a pathological state leading to serious organ dysfunction. Transforming growth factor beta1 (TGFβ1) is a strong inducer of myofibroblast formation and subsequent collagen production. Currently, there are no remedies for the treatment of fibrosis. Activation of the nuclear factor kappa B (NF-κB) pathway by phosphorylating IκB with the enzyme IκB kinase (IKK) plays a major role in the induction of fibrosis. ACHP {2-Amino-6-[2-(cyclopropylmethoxy)-6-hydroxyphenyl]-4-(4-piperidinyl)-3 pyridinecarbonitrile}, a selective inhibitor of IKK, prohibits the activation of the NF-κB pathway. It is not known whether ACHP has potential anti-fibrotic properties. Using adult human dermal and lung fibroblasts we have investigated whether ACHP has the ability to inhibit the TGFβ1-induced transition of fibroblasts into myofibroblasts and its excessive synthesis of ECM. The presence of ACHP strongly suppressed the induction of the myofibroblast markers alpha-smooth muscle actin (αSMA) and SM22α, as well as the deposition of the ECM components collagen type I and fibronectin. Furthermore, post-treatment with ACHP partly reversed the expression of αSMA and collagen type I production. Finally, ACHP suppressed the expression of the three collagen-modifying enzymes lysyl hydroxylase (PLOD1, PLOD2 and PLOD3) in dermal fibroblasts, but did not do so in lung fibroblasts. We conclude that the IKK inhibitor ACHP has potent antifibrotic properties, and that the NF-κB pathway plays an important role in myofibroblast biology. PMID:26337045

  10. Identification of a Developmental Gene Expression Signature, Including HOX Genes, for the Normal Human Colonic Crypt Stem Cell Niche: Overexpression of the Signature Parallels Stem Cell Overpopulation During Colon Tumorigenesis

    OpenAIRE

    Bhatlekar, Seema; Addya, Sankar; Salunek, Moreh; Orr, Christopher R.; Surrey, Saul; McKenzie, Steven; Fields, Jeremy Z.; Boman, Bruce M

    2013-01-01

    Our goal was to identify a unique gene expression signature for human colonic stem cells (SCs). Accordingly, we determined the gene expression pattern for a known SC-enriched region—the crypt bottom. Colonic crypts and isolated crypt subsections (top, middle, and bottom) were purified from fresh, normal, human, surgical specimens. We then used an innovative strategy that used two-color microarrays (∼18,500 genes) to compare gene expression in the crypt bottom with expression in the other cryp...

  11. Neutral biogeography and the evolution of climatic niches.

    Science.gov (United States)

    Boucher, Florian C; Thuiller, Wilfried; Davies, T Jonathan; Lavergne, Sébastien

    2014-05-01

    Recent debate on whether climatic niches are conserved through time has focused on how phylogenetic niche conservatism can be measured by deviations from a Brownian motion model of evolutionary change. However, there has been no evaluation of this methodological approach. In particular, the fact that climatic niches are usually obtained from distribution data and are thus heavily influenced by biogeographic factors has largely been overlooked. Our main objective here was to test whether patterns of climatic niche evolution that are frequently observed might arise from neutral dynamics rather than from adaptive scenarios. We developed a model inspired by neutral biodiversity theory, where individuals disperse, compete, and undergo speciation independently of climate. We then sampled the climatic niches of species according to their geographic position and showed that even when species evolve independently of climate, their niches can nonetheless exhibit evolutionary patterns strongly differing from Brownian motion. Indeed, climatic niche evolution is better captured by a model of punctuated evolution with constraints due to landscape boundaries, two features that are traditionally interpreted as evidence for selective processes acting on the niche. We therefore suggest that deviation from Brownian motion alone should not be used as evidence for phylogenetic niche conservatism but that information on phenotypic traits directly linked to physiology is required to demonstrate that climatic niches have been conserved through time. PMID:24739191

  12. Bronchoscopic resection of endobronchial inflammatory myofibroblastic tumor: A case report and systematic review of the literature

    Directory of Open Access Journals (Sweden)

    Animesh Ray

    2014-01-01

    Full Text Available Inflammatory myofibroblastic tumour (IMT is a rare tumour affecting the tracheo-bronchial tree in the adult population. The clinical presentation of this tumour is diverse and diagnosis can be definitively clinched by histopathological examination. Treatment of this tumour usually requires surgical resection with bronchoscopic resection being described in few cases. We describe a 32 year old male presenting with hemoptysis who was diagnosed to have IMT. Resection of the tumour was done with the help of rigid bronchoscopy. Post-resection, hemoptysis stopped and no recurrence of tumour was noted on subsequent follow-up. We also present a systematic review of literature of all the cases of tracheo-bronchial IMT treated with bronchoscopic resection and conclude it to be a useful alternative to surgery in such cases.

  13. A rare tumor of trachea: Inflammatory myofibroblastic tumor diagnosis and endoscopic treatment

    Directory of Open Access Journals (Sweden)

    Mehmet Akif Özgül

    2014-01-01

    Full Text Available Inflammatory myofibroblastic tumors (IMTs are rare childhood neoplasms, with benign clinical course. Although etiology of IMTs are not clear, recent studies have reported that IMT is a true neoplasm rather than a reactive or inflammatory lesion. IMTs are rarely seen in adults and tracheal involvement is also rare both in adults and also in children. We describe a 16-year old female patient who was misdiagnosed and treated as asthma in another center for a few months and presented with acute respiratory distress due to upper airway obstruction. Computerized tomography (CT of the chest and rigid bronchoscopy revealed a mass lesion that was nearly totally obliterating tracheal lumen. Bronchoscopic resection was performed under general anesthesia and the final pathological diagnosis was tracheal IMT.

  14. Regulation of Hematopoietic Stem Cells by Bone Marrow Stromal Cells

    OpenAIRE

    Anthony, Bryan; Link, Daniel C.

    2013-01-01

    Hematopoietic stem cells (HSCs) reside in specialized microenvironments (niches) in the bone marrow. The stem cell niche is thought to provide signals that support key HSC properties, including self-renewal capacity and long-term multilineage repopulation ability. The stromal cells that comprise the stem cell niche and the signals that they generate that support HSC function are the subjects of intense investigation. Here we review the complex and diverse stromal cell populations that reside ...

  15. Claregalway Franciscan Friary, north chancel wall, tomb niche, jamb

    OpenAIRE

    O'Donovan, Danielle

    2001-01-01

    Jamb of tomb niche, larger rolls topped by capitals and bases. Moulding from inner face comprises: large roll, hollow, roll, hollow, roll, hollow, large roll, hollow, roll, hollow, roll - this roll runs into the flat wall surface. Few of these western tomb niches have separate straight jambs with shafts provided with capitals and bases - this occurs more in fourteenth-century work like that at Kilmallock Dominican Priory, suggesting that this niche at Claregalway may be similar in date to tha...

  16. Can Niche Agriculturalists Take Notes from the Craft Beer Industry?

    OpenAIRE

    Woolverton, Andrea E.; Parcell, Joseph L.

    2008-01-01

    This industry-level case study focuses on the growth cycles of craft brewing, a niche industry. The research case is defined as the craft beer industry evolution including the surrounding institutional and consumer environments. The research goal is to provide insight for niche agriculturalists by examining the case of the successful niche craft beer industry. First, the environment surrounding craft beer reemergence is analyzed. We examine the current state of the craft beer industry with a ...

  17. Evidence of climatic niche shift during biological invasion

    OpenAIRE

    Broennimann, Olivier; Urs A Treier; Müller-Schärer, Heinz; Thuiller, W.; Peterson, A. T.; Guisan, Antoine

    2007-01-01

    Niche-based models calibrated in the native range by relating species observations to climatic variables are commonly used to predict the potential spatial extent of species’ invasion. This climate matching approach relies on the assumption that invasive species conserve their climatic niche in the invaded ranges. We test this assumption by analysing the climatic niche spaces of Spotted Knapweed in western North America and Europe. We show with robust cross-continental data that a shift of th...

  18. Socs36E Controls Niche Competition by Repressing MAPK Signaling in the Drosophila Testis.

    Directory of Open Access Journals (Sweden)

    Marc Amoyel

    2016-01-01

    Full Text Available The Drosophila testis is a well-established system for studying stem cell self-renewal and competition. In this tissue, the niche supports two stem cell populations, germ line stem cells (GSCs, which give rise to sperm, and somatic stem cells called cyst stem cells (CySCs, which support GSCs and their descendants. It has been established that CySCs compete with each other and with GSCs for niche access, and mutations have been identified that confer increased competitiveness to CySCs, resulting in the mutant stem cell and its descendants outcompeting wild type resident stem cells. Socs36E, which encodes a negative feedback inhibitor of the JAK/STAT pathway, was the first identified regulator of niche competition. The competitive behavior of Socs36E mutant CySCs was attributed to increased JAK/STAT signaling. Here we show that competitive behavior of Socs36E mutant CySCs is due in large part to unbridled Mitogen-Activated Protein Kinase (MAPK signaling. In Socs36E mutant clones, MAPK activity is elevated. Furthermore, we find that clonal upregulation of MAPK in CySCs leads to their outcompetition of wild type CySCs and of GSCs, recapitulating the Socs36E mutant phenotype. Indeed, when MAPK activity is removed from Socs36E mutant clones, they lose their competitiveness but maintain self-renewal, presumably due to increased JAK/STAT signaling in these cells. Consistently, loss of JAK/STAT activity in Socs36E mutant clones severely impairs their self-renewal. Thus, our results enable the genetic separation of two essential processes that occur in stem cells. While some niche signals specify the intrinsic property of self-renewal, which is absolutely required in all stem cells for niche residence, additional signals control the ability of stem cells to compete with their neighbors. Socs36E is node through which these processes are linked, demonstrating that negative feedback inhibition integrates multiple aspects of stem cell behavior.

  19. Niche Genetic Algorithm with Accurate Optimization Performance

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-hua; YAN De-kun

    2005-01-01

    Based on crowding mechanism, a novel niche genetic algorithm was proposed which can record evolutionary direction dynamically during evolution. After evolution, the solutions's precision can be greatly improved by means of the local searching along the recorded direction. Simulation shows that this algorithm can not only keep population diversity but also find accurate solutions. Although using this method has to take more time compared with the standard GA, it is really worth applying to some cases that have to meet a demand for high solution precision.

  20. Erythroblastic Islands: Specialized Mircoenvironmental Niches forErythropoiesis

    Energy Technology Data Exchange (ETDEWEB)

    Chasis, Joel Anne

    2006-01-06

    This review focuses on current understanding of molecular mechanisms operating within erythroblastic islands including cell-cell adhesion, regulatory feedback, and central macrophage function. RECENT FINDINGS: Erythroblasts express a variety of adhesion molecules and recently two interactions have been identified that appear to be critical for island integrity. Erythroblast macrophage protein, expressed on erythroblasts and macrophages, mediates cell-cell attachments via homophilic binding. Erythroblast intercellular adhesion molecule-4 links erythroblasts to macrophages through interaction with macrophage alphav integrin. In intercellular adhesion molecule-4 knockout mice, erythroblastic islands are markedly reduced, whereas the erythroblast macrophage protein null phenotype is severely anemic and embryonic lethal. Retinoblastoma tumor suppressor (Rb) protein stimulates macrophage differentiation by counteracting inhibition of Id2 on PU.1, a transcription factor that is a crucial regulator of macrophage differentiation. Rb-deficient macrophages do not bind Rb null erythroblasts and the Rb null phenotype is anemic and embryonic lethal. Lastly, extruded nuclei rapidly expose phosphatidylserine on their surface, providing a recognition signal similar to apoptotic cells. SUMMARY: Although understanding of molecular mechanisms operating within islands is at an early stage, tantalizing evidence suggests that erythroblastic islands are specialized niches where intercellular interactions in concert with cytokines play critical roles in regulating erythropoiesis.

  1. Market niche analysis in the casino gaming industry.

    Science.gov (United States)

    Dandurand, L

    1990-03-01

    This article discusses the nature of market niche analysis in the casino gaming industry. It presents four approaches for conducting market niche analysis. An an example of one approach, the Las Vegas Visitor Profile Study is used to identify a premium niche in the Las Vegas Slot Target Market. A detailed examination of the premium niche profile provides a description of the typical premium slot player. The description of the typical premium player leads to hypotheses regarding needs (the unique preference set) of the premium player. An analysis of the unique preference set suggests an appropriate enhanced marketing program. PMID:24242795

  2. Ecological niche transferability using invasive species as a case study.

    Directory of Open Access Journals (Sweden)

    Miguel Fernández

    Full Text Available Species distribution modeling is widely applied to predict invasive species distributions and species range shifts under climate change. Accurate predictions depend upon meeting the assumption that ecological niches are conserved, i.e., spatially or temporally transferable. Here we present a multi-taxon comparative analysis of niche conservatism using biological invasion events well documented in natural history museum collections. Our goal is to assess spatial transferability of the climatic niche of a range of noxious terrestrial invasive species using two complementary approaches. First we compare species' native versus invasive ranges in environmental space using two distinct methods, Principal Components Analysis and Mahalanobis distance. Second we compare species' native versus invaded ranges in geographic space as estimated using the species distribution modeling technique Maxent and the comparative index Hellinger's I. We find that species exhibit a range of responses, from almost complete transferability, in which the invaded niches completely overlap with the native niches, to a complete dissociation between native and invaded ranges. Intermediate responses included expansion of dimension attributable to either temperature or precipitation derived variables, as well as niche expansion in multiple dimensions. We conclude that the ecological niche in the native range is generally a poor predictor of invaded range and, by analogy, the ecological niche may be a poor predictor of range shifts under climate change. We suggest that assessing dimensions of niche transferability prior to standard species distribution modeling may improve the understanding of species' dynamics in the invaded range.

  3. Ecological niche transferability using invasive species as a case study.

    Science.gov (United States)

    Fernández, Miguel; Hamilton, Healy

    2015-01-01

    Species distribution modeling is widely applied to predict invasive species distributions and species range shifts under climate change. Accurate predictions depend upon meeting the assumption that ecological niches are conserved, i.e., spatially or temporally transferable. Here we present a multi-taxon comparative analysis of niche conservatism using biological invasion events well documented in natural history museum collections. Our goal is to assess spatial transferability of the climatic niche of a range of noxious terrestrial invasive species using two complementary approaches. First we compare species' native versus invasive ranges in environmental space using two distinct methods, Principal Components Analysis and Mahalanobis distance. Second we compare species' native versus invaded ranges in geographic space as estimated using the species distribution modeling technique Maxent and the comparative index Hellinger's I. We find that species exhibit a range of responses, from almost complete transferability, in which the invaded niches completely overlap with the native niches, to a complete dissociation between native and invaded ranges. Intermediate responses included expansion of dimension attributable to either temperature or precipitation derived variables, as well as niche expansion in multiple dimensions. We conclude that the ecological niche in the native range is generally a poor predictor of invaded range and, by analogy, the ecological niche may be a poor predictor of range shifts under climate change. We suggest that assessing dimensions of niche transferability prior to standard species distribution modeling may improve the understanding of species' dynamics in the invaded range. PMID:25785858

  4. 肺转移瘤的转移前微环境与转移微环境%Pre-metastatic Niche and Metastatic Niche of Metastatic Lung Tumors

    Institute of Scientific and Technical Information of China (English)

    郑燕

    2011-01-01

    一个多世纪前Paget就肿瘤器官特异性转移现象提出了“种子与土壤”学说.时下研究热点集中在一些特殊因子介导的靶器官环境改造,肿瘤细胞归巢行为.有动物实验证实肺转移瘤形成前,肺部已发生大量炎症因子聚集.宿主靶器官的改变影响转移瘤形成的每一个步骤.Bethan Psaila与David Lyden针对这一土壤变化过程提出转移前微环境(pre-metastatic niche)及转移微环境(metastatic niche)假说,指出土壤的变化是转移瘤形成的保障.该假说提出后迅速引起肿瘤研究界轰动.研究这一系列细胞分子生物学的改变,有助于阐明肿瘤转移这一复杂的过程,为转移干预带来新的思路.%Steven Paget's "seed and soil" hypothesis for metastasis was a pivotal milestone in the study of malignant disease. Current views of cancer metastasis have centered on the intrinsic factors mediating preparation of the target organ and regulating the cell autonomous homing of tumor cells to the metastatic site. Many inflammatory cytokines in the lung provide an assembly platform for metastatic lesions, as shown by in vivo experimental models. New findings suggest that host cells within the target microenviroment play a key role in influencing each step of metastatic progression. Bethan Psaila and David Lyden have proposed a pre-metastatic niche and metastatic niche model to delineate the interactions of malignant cells with their microenvironment at the metastatic site. The niche model suggests that a suitably conducive microenvironment is essential in order for tumor cells to engraft and proliferate at secondary sites. It has quickly become the most influential hypothesis. Focusing on the cellular and molecular events in cancer dissemination and selectivity will likely lead to new approaches to explain the events and to prevent metastasis at each step.

  5. Embryonic regulation of the mouse erythropoietic niche and its clinical application.

    Science.gov (United States)

    Sugiyama, Daisuke; Tanaka, Yuka; Yumine, Ayako; Kojima, Naoko

    2016-07-01

    Erythropoiesis has classically been described as occurring in two waves: first primitive and then definitive erythropoiesis. In the mouse embryo, definitive erythropoiesis begins in the yolk sac and then shifts to the liver, spleen, and bone marrow. The fetal liver serves as the primary organ for erythroid cell expansion and maturation at mid-gestation and its mechanisms have been well investigated with special attention to niche cells expressing cytokines such as SCF, TPO and IGF2. Previously, our group reported that DLK1(+) hepatoblasts support fetal liver hematopoiesis, particularly erythropoiesis, through EPO, SCF and matrix secretion. Loss of DLK1(+) hepatoblasts in Map2k4(-/-) mouse embryos resulted in decreased numbers of hematopoietic cells in the fetal liver. When sorted DLK1(+) hepatoblasts were further analyzed by microarray, several genes encoding proteinases and peptidases were highly expressed in DLK1(+) hepatoblasts. Based on the hypothesis that high molecular weight proteins are digested into small peptides that may regulate hematopoiesis, we screened out peptides, and identified KS-13 (PCT/JP2010/067011). Both KS-13 and modified KS-13, known as SL-13R, proliferate and increase the number of hematopoietic stem/progenitors from human cord blood cells in vitro. We hereby present our findings on the extrinsic regulation of embryonic erythropoiesis with special attention to niche cells, identification of niche-derived peptides, and implications for future hematotherapy. PMID:27498742

  6. Climatic niche at physiological and macroecological scales: The thermal tolerance-geographical range interface and niche dimensionality

    OpenAIRE

    Gouveia, S. F.; Hortal, Joaquín; Tejedo, Miguel; Duarte, Helder; Cassemiro, F. A. S.; Navas, C. A.; J. A. F. Diniz-filho

    2014-01-01

    Aim: Under the Hutchinsonian concept of the realized niche, biotic interactions and dispersal limitation may prevent species from fully occupying areas that they could tolerate physiologically. This can hamper the translation of physiological limits into climatically defined range limits and distorts inferences of evolutionary changes of the adaptive limits (i.e. niche conservatism). In contrast, heritable physiological limits should conform more closely to the position of the niche in the cl...

  7. Symbiosis catalyses niche expansion and diversification.

    Science.gov (United States)

    Joy, Jeffrey B

    2013-04-01

    Interactions between species are important catalysts of the evolutionary processes that generate the remarkable diversity of life. Symbioses, conspicuous and inherently interesting forms of species interaction, are pervasive throughout the tree of life. However, nearly all studies of the impact of species interactions on diversification have concentrated on competition and predation leaving unclear the importance of symbiotic interaction. Here, I show that, as predicted by evolutionary theories of symbiosis and diversification, multiple origins of a key innovation, symbiosis between gall-inducing insects and fungi, catalysed both expansion in resource use (niche expansion) and diversification. Symbiotic lineages have undergone a more than sevenfold expansion in the range of host-plant taxa they use relative to lineages without such fungal symbionts, as defined by the genetic distance between host plants. Furthermore, symbiotic gall-inducing insects are more than 17 times as diverse as their non-symbiotic relatives. These results demonstrate that the evolution of symbiotic interaction leads to niche expansion, which in turn catalyses diversification. PMID:23390106

  8. ABCG2pos lung mesenchymal stem cells are a novel pericyte subpopulation that contributes to fibrotic remodeling

    OpenAIRE

    Marriott, Shennea; Baskir, Rubin S.; Gaskill, Christa; Menon, Swapna; Carrier, Erica J.; Williams, Janice; Talati, Megha; Helm, Karen; Alford, Catherine E.; Kropski, Jonathan A.; Loyd, James; Wheeler, Lisa; Johnson, Joyce; Austin, Eric; Nozik-Grayck, Eva

    2014-01-01

    Genesis of myofibroblasts is obligatory for the development of pathology in many adult lung diseases. Adult lung tissue contains a population of perivascular ABCG2pos mesenchymal stem cells (MSC) that are precursors of myofibroblasts and distinct from NG2 pericytes. We hypothesized that these MSC participate in deleterious remodeling associated with pulmonary fibrosis (PF) and associated hypertension (PH). To test this hypothesis, resident lung MSC were quantified in lung samples from control...

  9. Teachers Unions in Turbulent Times: Maintaining Their Niche

    Science.gov (United States)

    Young, Tamara V.

    2011-01-01

    Drawing on niche theory, I describe the resource dimensions that compose teachers unions' niche and explain how aspects of the current political landscape buttress or undermine teachers unions' realization of those resources. I also discuss teachers unions' strategies to oppose any threats that undermine the realization of the resource arrays that…

  10. Using specialty advertising in a niche marketing plan.

    Science.gov (United States)

    Schwisow, C R

    1992-01-01

    While niche marketing is not a new strategy, an increasing number of competitors are pursuing the same niches, resulting in stiff competition within the health care industry, writes C. Ronald Schwisow. This means marketers need to be resourceful to maximize their communications efforts. One such approach is specialty advertising. PMID:10118999

  11. Competition in a technological niche: the cars of the future

    NARCIS (Netherlands)

    Bakker, S.; Lente, H. van; Engels, R.

    2012-01-01

    The notion of ‘niche’has proved to be useful to account for the emergence of radical innovations. Most studies, however, deal with the development of single emerging technologies. In this paper we address the competition between multiple niche technologies.Within the niche of the ‘car of the future’

  12. Melanosomes foster a tumour niche by activating CAFs.

    Science.gov (United States)

    García-Silva, Susana; Peinado, Héctor

    2016-08-30

    Extracellular vesicles, such as exosomes, are important effectors in the formation of tumour-fostering niches. Pigmented melanosomes are now shown to have a relevant role in establishing a tumour niche in primary melanoma by reprogramming dermal fibroblasts into cancer-associated fibroblasts through the transfer of miR-211. PMID:27571736

  13. Phylogenetic signals in the climatic niches of the world's amphibians

    DEFF Research Database (Denmark)

    Hof, Christian; Rahbek, Carsten; Araújo, Miguel B.

    2010-01-01

    The question of whether closely related species share similar ecological requirements has attracted increasing attention, because of its importance for understanding global diversity gradients and the impacts of climate change on species distributions. In fact, the assumption that related species...... are also ecologically similar has often been made, although the prevalence of such a phylogenetic signal in ecological niches remains heavily debated. Here, we provide a global analysis of phylogenetic niche relatedness for the world's amphibians. In particular, we assess which proportion of the...... variance in the realised climatic niches is explained on higher taxonomic levels, and whether the climatic niches of species within a given taxonomic group are more similar than between taxonomic groups. We found evidence for phylogenetic signals in realised climatic niches although the strength of the...

  14. Evidence of climatic niche shift during biological invasion

    DEFF Research Database (Denmark)

    Broennimann, O.; Treier, Urs; Müller-Schärer, H.;

    2007-01-01

    Niche-based models calibrated in the native range by relating species observations to climatic variables are commonly used to predict the potential spatial extent of species' invasion. This climate matching approach relies on the assumption that invasive species conserve their climatic niche...... evidence that an invasive species can occupy climatically distinct niche spaces following its introduction into a new area. The models fail to predict the current invaded distribution, but correctly predict areas of introduction. Climate matching is thus a useful approach to identify areas at risk...... in the invaded ranges. We test this assumption by analysing the climatic niche spaces of Spotted Knapweed in western North America and Europe. We show with robust cross-continental data that a shift of the observed climatic niche occurred between native and non-native ranges, providing the first empirical...

  15. Evidence of climatic niche shift during biological invasion.

    Science.gov (United States)

    Broennimann, O; Treier, U A; Müller-Schärer, H; Thuiller, W; Peterson, A T; Guisan, A

    2007-08-01

    Niche-based models calibrated in the native range by relating species observations to climatic variables are commonly used to predict the potential spatial extent of species' invasion. This climate matching approach relies on the assumption that invasive species conserve their climatic niche in the invaded ranges. We test this assumption by analysing the climatic niche spaces of Spotted Knapweed in western North America and Europe. We show with robust cross-continental data that a shift of the observed climatic niche occurred between native and non-native ranges, providing the first empirical evidence that an invasive species can occupy climatically distinct niche spaces following its introduction into a new area. The models fail to predict the current invaded distribution, but correctly predict areas of introduction. Climate matching is thus a useful approach to identify areas at risk of introduction and establishment of newly or not-yet-introduced neophytes, but may not predict the full extent of invasions. PMID:17594425

  16. A Mechanistic Niche Model for Measuring Species' Distributional Responses to Seasonal Temperature Gradients

    OpenAIRE

    Monahan, William B.

    2009-01-01

    Niche theory is central to understanding how species respond geographically to climate change. It defines a species' realized niche in a biological community, its fundamental niche as determined by physiology, and its potential niche--the fundamental niche in a given environment or geographic space. However, most predictions of the effects of climate change on species' distributions are limited to correlative models of the realized niche, which assume that species are in distributional equili...

  17. Targeting of the pulmonary capillary vascular niche promotes lung alveolar repair and ameliorates fibrosis

    OpenAIRE

    Cao, Zhongwei; Lis, Raphael; Ginsberg, Michael; Chavez, Deebly; Shido, Koji; Rabbany, Sina Y.; Fong, Guo-Hua; Sakmar, Thomas P.; Rafii, Shahin; Ding, Bi-Sen

    2016-01-01

    Although the lung can undergo self-repair after injury, fibrosis in chronically injured or diseased lungs can occur at the expense of regeneration. Here we study how a hematopoietic-vascular niche regulates alveolar repair and lung fibrosis. Using intratracheal injection of bleomycin or hydrochloric acid in mice, we show that repetitive lung injury activates pulmonary capillary endothelial cells (PCECs) and perivascular macrophages, impeding alveolar repair and promoting fibrosis. Whereas the...

  18. Sexual Niche Segregation and Gender-Specific Individual Specialisation in a Highly Dimorphic Marine Mammal

    OpenAIRE

    Laëtitia Kernaléguen; Yves Cherel; Knox, Travis C.; Baylis, Alastair M M; John P Y Arnould

    2015-01-01

    While sexual segregation is expected in highly dimorphic species, the local environment is a major factor driving the degree of resource partitioning within a population. Sexual and individual niche segregation was investigated in the Australian fur seal (Arctocephalus pusillus doriferus), which is a benthic foraging species restricted to the shallow continental shelf region of south-eastern Australia. Tracking data and the isotopic values of plasma, red blood cells and whiskers were combined...

  19. Life history, cognition and the evolution of complex foraging niches.

    Science.gov (United States)

    Schuppli, Caroline; Graber, Sereina M; Isler, Karin; van Schaik, Carel P

    2016-03-01

    Animal species that live in complex foraging niches have, in general, improved access to energy-rich and seasonally stable food sources. Because human food procurement is uniquely complex, we ask here which conditions may have allowed species to evolve into such complex foraging niches, and also how niche complexity is related to relative brain size. To do so, we divided niche complexity into a knowledge-learning and a motor-learning dimension. Using a sample of 78 primate and 65 carnivoran species, we found that two life-history features are consistently correlated with complex niches: slow, conservative development or provisioning of offspring over extended periods of time. Both act to buffer low energy yields during periods of learning, and may thus act as limiting factors for the evolution of complex niches. Our results further showed that the knowledge and motor dimensions of niche complexity were correlated with pace of development in primates only, and with the length of provisioning in only carnivorans. Accordingly, in primates, but not carnivorans, living in a complex foraging niche requires enhanced cognitive abilities, i.e., a large brain. The patterns in these two groups of mammals show that selection favors evolution into complex niches (in either the knowledge or motor dimension) in species that either develop more slowly or provision their young for an extended period of time. These findings help to explain how humans constructed by far the most complex niche: our ancestors managed to combine slow development (as in other primates) with systematic provisioning of immatures and even adults (as in carnivorans). This study also provides strong support for the importance of ecological factors in brain size evolution. PMID:26989019

  20. Diet and trophic niche of Lithobates catesbeianus (Amphibia: Anura

    Directory of Open Access Journals (Sweden)

    Peterson T. Leivas

    2012-10-01

    Full Text Available Lithobates catesbeianus (Shaw, 1802 is an invasive anuran introduced in Brazil that is associated with the displacement and the decline of populations of native species worldwide. There is evidence that biological invasions are facilitated by certain attributes of the invading species, for instance niche breath, and that invasive species have a broader ecological niche with respect to native ones. We designed a study to ascertain the temporal, ontogenetic, and sex differences in the niche dynamics of the American bullfrog. We sampled monthly from June 2008 to May 2009 in the state of Paraná, southern Brazil. For each individual, we gathered biometric and stomach content data. We then estimated the niche breath of the juveniles and adults, and compared it between the sexes. A total of 104 females and 77 males were sampled. Lithobates catesbeianus has a generalist diet, preying upon invertebrates and vertebrates. Even though the diet of the studied population varied seasonally, it did not differ between the sexes nor did it respond to biometric variables. Niche breadth was more restricted in the winter than in the autumn. The trophic niche of juveniles and adults did not overlap much when compared with the trophic niche overlap between males and females. Adult males and females had a considerable niche overlap, but females had a broader trophic niche than males in the winter and in the spring. These niche characteristics point to an opportunistic predation strategy that may have facilitated the process of invasion and establishment of this species in the study area.