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Sökning: WFRF:(Friman Tomas)

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1.
  • Kelkka, Tiina, et al. (författare)
  • Mice Lacking NCF1 Exhibit Reduced Growth of Implanted Melanoma and Carcinoma Tumors
  • 2013
  • Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:12, s. e84148-
  • Tidskriftsartikel (refereegranskat)abstract
    • The NADPH oxidase 2 (NOX2) complex is a professional producer of reactive oxygen species (ROS) and is mainly expressed in phagocytes. While the activity of the NOX2 complex is essential for immunity against pathogens and protection against autoimmunity, its role in the development of malignant tumors remains unclear. We compared wild type and Ncf1(m1J) mutated mice, which lack functional NOX2 complex, in four different tumor models. Ncf1(m1J) mutated mice developed significantly smaller tumors in two melanoma models in which B16 melanoma cells expressing a hematopoietic growth factor FLT3L or luciferase reporter were used. Ncf1(m1J) mutated mice developed significantly fewer Lewis Lung Carcinoma (LLC) tumors, but the tumors that did develop, grew at a pace that was similar to the wild type mice. In the spontaneously arising prostate carcinoma model (TRAMP), tumor growth was not affected. The lack of ROS-mediated protection against tumor growth was associated with increased production of immunity-associated cytokines. A significant increase in Th2 associated cytokines was observed in the LLC model. Our present data show that ROS regulate rejection of the antigenic B16-luc and LLC tumors, whereas the data do not support a role for ROS in growth of intrinsically generated tumors.
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2.
  • Ahrén, Dag, et al. (författare)
  • Comparison of gene expression in trap cells and vegetative hyphae of the nematophagous fungus Monacrosporium haptotylum
  • 2005
  • Ingår i: Microbiology. - : Microbiology Society. - 1465-2080 .- 1350-0872. ; 151:3, s. 789-803
  • Tidskriftsartikel (refereegranskat)abstract
    • Nematode-trapping fungi enter the parasitic stage by developing specific morphological structures called traps. The global patterns of gene expression in traps and mycelium of the fungus Monacrosporium haptotylum were compared. The trap of this fungus is a unicellular spherical structure called the knob, which develops on the apex of a hyphal branch. RNA was isolated from knobs and mycelium and hybridized to a cDNA array containing probes of 2822 EST clones of M. haptotylum. Despite the fact that the knobs and mycelium were grown in the same medium, there were substantial differences in the patterns of genes expressed in the two cell types. In total, 23(.)3% (657 of 2822) of the putative genes were differentially expressed in knobs versus mycelium. Several of these genes displayed sequence similarities to genes known to be involved in regulating morphogenesis and cell polarity in fungi. Among them were several putative homologues for small GTPases, such as rho1, rac1 and ras1, and a rho GDP dissociation inhibitor (rdi1). Several homologues to genes involved in stress response, protein synthesis and protein degradation, transcription, and carbon metabolism were also differentially expressed. In the last category, a glycogen phosphorylase (gph1) gene homologue, one of the most upregulated genes in the knobs as compared to mycelium, was characterized. A number of the genes that were clifferentially expressed in trap cells are also known to be regulated during the development of infection structures in plant-pathogenic fungi. Among them, a gas1 (mas3) gene homologue (designated gks1), which is specifically expressed in appressoria of the rice blast fungus, was characterized.
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3.
  • Einarsdottir, Sigrun, et al. (författare)
  • Deficiency of SARS-CoV-2 T-cell responses after vaccination in long-term allo-HSCT survivors translates into abated humoral immunity.
  • 2022
  • Ingår i: Blood advances. - : American Society of Hematology. - 2473-9537 .- 2473-9529. ; 6:9, s. 2723-2730
  • Tidskriftsartikel (refereegranskat)abstract
    • Recipients of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for hematological diseases are at risk of severe disease and death from COVID-19. To determine the safety and immunogenicity of BNT162b2 and mRNA-1273 COVID-19 vaccines, samples from 50 infection-naive allo-HSCT recipients (median, 92 months from transplantation, range, 7-340 months) and 39 healthy controls were analyzed for serum immunoglobulin G (IgG) against the receptor binding domain (RBD) within spike 1 (S1) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; anti-RBD-S1 IgG) and for SARS-CoV-2-specific T-cell immunity, reflected by induction of T-cell-derived interferon-γ in whole blood stimulated ex vivo with 15-mer SI-spanning peptides with 11 amino acid overlapS1-spanning peptides. The rate of seroconversion was not significantly lower in allo-transplanted patients than in controls with 24% (12/50) and 6% (3/50) of patients remaining seronegative after the first and second vaccination, respectively. However, 58% of transplanted patients lacked T-cell responses against S1 peptides after 1 vaccination compared with 19% of controls (odds ratio [OR] 0.17; P = .009, Fisher's exact test) with a similar trend after the second vaccination where 28% of patients were devoid of detectable specific T-cell immunity, compared with 6% of controls (OR 0.18; P = .02, Fisher's exact test). Importantly, lack of T-cell reactivity to S1 peptides after vaccination heralded substandard levels (<100 BAU/mL) of anti-RBD-S1 IgG 5 to 6 months after the second vaccine dose (OR 8.2; P = .007, Fisher's exact test). We conclude that although allo-HSCT recipients achieve serum anti-RBD-S1 IgG against SARS-CoV-2 after 2 vaccinations, a deficiency of SARS-CoV-2-specific T-cell immunity may subsequently translate into insufficient humoral responses.
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4.
  • Einarsdottir, Sigrun, et al. (författare)
  • Vaccination against tick-borne encephalitis (TBE) after autologous and allogeneic stem cell transplantation
  • 2021
  • Ingår i: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 39:7, s. 1035-1038
  • Tidskriftsartikel (refereegranskat)abstract
    • Introduction: Our aim was to assess response and side effects of 4 doses of TBE vaccine to patients (pts) after allo- and autologous stem cell transplantation (SCT). PATIENTS: Included were 104 pts with leukaemia, myeloma and lymphoma, median age 61 yrs. METHODS: Vaccine (FSME-Immun (R)) was given at 9, 10, 12, and 21 months post-transplant. Serum samples were obtained before and after vaccinations. Healthy controls (n = 27) received 3 vaccinations. Assessments of TBE specific IgG antibodies were performed by Enzygnost anti-TBE ELISA test (Siemens, Sweden). Results: Antibody levels (>12 U/mL; "seropositivity") were seen in 77% and 80% of pts after allo- and autoSCT; IgG levels; 89 vs 94 U/mL. Ongoing chronic GvHD and immunosuppression (n = 29) was associated with sero-negativity in the last sample (p = 0.007). All controls (n = 27) developed protective antibody levels. Conclusions: TBE vaccination was safe, and 4 doses starting 9 months post-SCT, induced seropositivity in a vast majority of pts. (C) 2021 Elsevier Ltd. All rights reserved.
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5.
  • Emanuelsson, Ida, et al. (författare)
  • Vitamin D Analogues Tacalcitol and Calcipotriol Inhibit Proliferation and Migration of T98G Human Glioblastoma Cells
  • 2018
  • Ingår i: Neuroscience. - : John Wiley & Sons. - 0306-4522 .- 1873-7544.
  • Tidskriftsartikel (refereegranskat)abstract
    • The active form of vitamin D (1,25-dihydroxyvitamin D) acts as a steroid hormone and binds to the vitamin D receptor. This receptor is expressed in most cell types including cells in the central nervous system (CNS). Vitamin D has several functions in the body including effects on brain development, neuroprotection and immunological regulation. It has been shown that vitamin D has antiproliferative activities in different cancer cell lines. Tacalcitol and calcipotriol are synthetic analogues of 1,25-dihydroxyvitamin D with reduced effect on calcium metabolism. The aim of this study was to analyse the effects of tacalcitol and calcipotriol on cell viability, proliferation and migration in the human glioblastoma cell line T98G. Glioblastoma is the most lethal type of primary tumours in the CNS. Both analogues decreased cell viability and/or growth, dose-dependently, in concentrations between 1 nM and 10 M. Manual counting indicated suppressive effects by the vitamin D analogues on proliferation. Treatment with tacalcitol strongly suppressed thymidine incorporation, indicating that the vitamin D analogues mainly inhibit proliferation. Also, effects on cell migration were measured with wound-healing assay. Both calcipotriol and tacalcitol reduced the migration rate of T98G cells compared to vehicle-treated cells. However, they had no effect on caspase-3 and -7 activities, suggesting that their mechanism of action does not involve induction of apoptosis. The current results indicate that the vitamin D analogues tacalcitol and calcipotriol strongly reduce proliferation and migration of human glioblastoma T98G cells, suggesting a potential role for this type of compounds in treatment of brain cancer.
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6.
  • Fekete, Csaba, et al. (författare)
  • Paralysis of nematodes: shifts in the transcriptome of the nematode-trapping fungus Monacrosporium haptotylum during infection of Caenorhabditis elegans
  • 2008
  • Ingår i: Environmental Microbiology. - : Wiley. - 1462-2920 .- 1462-2912. ; 10:2, s. 364-375
  • Tidskriftsartikel (refereegranskat)abstract
    • The transcriptional response in the parasitic fungus Monacrosporium haptotylum and its nematode host Caenorhabditis elegans were analyzed during infection using cDNA microarrays. The array contained 2,684 fungal and 372 worm gene reporters. Dramatic shifts occurred in the transcriptome of M. haptotylum during the different stages of the infection. An initial transcriptional response was recorded after 1h of infection when the traps adhered to the cuticle, but before immobilization of the captured nematodes. Among the differentially expressed genes were two serine proteases (spr1 and spr2), and several homologues to genes known to be regulated in other pathogenic fungi. After 4 hours, when approximately 40 % of the nematodes were paralyzed, we identified an up-regulated cluster of 372 fungal genes which were not regulated during the other phases of the infection. This cohort contained a large proportion (79%) of genes that appear to be specific for M. haptotylum and closely related species. These genes were of two different classes; those translating into presumably functional peptides and those with no apparent protein coding potential (noncoding RNAs). Among the infection-induced C. elegans genes were those encoding antimicrobial peptides, protease inhibitors and lectins.
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7.
  • Friman, Tomas, 1980- (författare)
  • Extracellular Matrix and Connective Tissue Cells of the Tumor Microenvironment
  • 2010
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • In addition to malignant cells, solid tumors comprise supporting stromal tissue that consists of extra cellular matrix (ECM), connective tissue cells, inflammatory cells and blood vessels. The stromal compartment and the malignant cells together shape the tumor microenvironment that in turn determines tumor progression and efficacy of anti-tumor treatments. In this thesis, studies that investigate the roles of different kinds of interactions between tumor cells and stromal cells were undertaken. Further, growth factors that have important roles in interactions between tumor cells and stromal cells were investigated in a non-tumor environment. Tumor cells were found to modulate the response to the platelet derived growth factor  (PDGF) by microvascular pericytes, a cell type found in the vasculature of solid tumors. The importance of this growth factor in biology of tumors has earlier been shown, but here it was shown that PDGF also modulate the ECM phenotype of solid tumors. The ECM of tumors treated with an inhibitor of PDGF receptor (PDGFR) signaling induced a less fibrotic collagen scaffold, which could explain how PDGFR inhibition in earlier reports lowered tumor interstitial fluid pressure (IFP). Lowering the normally high IFP in tumors increases efficacy of chemotherapy. The integrin αVβ3 is activated downstream of PDGF-B in acute inflammations, and this integrin is important for raising IFP in loose connective tissue in such conditions. However, in tumors we found that lack of the β3 subunit lead to an increased IFP, which were attributed to a more fibrotic ECM phenotype. In addition to PDGF-B, transforming growth factor β (TGFβ) is an important growth factor in the biology of tumors. These two growth factors were separately overexpressed in mouse skin and they both induced an inflammatory response. Expressed in a tumor free context, they evoked a response that was in many ways reminiscent of what can be observed in the tumor microenvironment. This thesis contributes further understanding of how the complex tumor microenvironment affects the phenotype of solid tumors.
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8.
  • Friman, Tomas, et al. (författare)
  • Increased Fibrosis and Interstitial Fluid Pressure in Two Different Types of Syngeneic Murine Carcinoma Grown in Integrin β3-Subunit Deficient Mice
  • 2012
  • Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:3, s. e34082-
  • Tidskriftsartikel (refereegranskat)abstract
    • Stroma properties affect carcinoma physiology and direct malignant cell development. Here we present data showing that alpha(V)beta(3) expressed by stromal cells is involved in the control of interstitial fluid pressure (IFP), extracellular volume (ECV) and collagen scaffold architecture in experimental murine carcinoma. IFP was elevated and ECV lowered in syngeneic CT26 colon and LM3 mammary carcinomas grown in integrin beta(3)-deficient compared to wild-type BALB/ c mice. Integrin beta(3)-deficiency had no effect on carcinoma growth rate or on vascular morphology and function. Analyses by electron microscopy of carcinomas from integrin beta(3)-deficient mice revealed a coarser and denser collagen network compared to carcinomas in wild-type littermates. Collagen fibers were built from heterogeneous and thicker collagen fibrils in carcinomas from integrin beta(3)-deficient mice. The fibrotic extracellular matrix (ECM) did not correlate with increased macrophage infiltration in integrin beta(3)-deficient mice bearing CT26 tumors, indicating that the fibrotic phenotype was not mediated by increased inflammation. In conclusion, we report that integrin beta(3)-deficiency in tumor stroma led to an elevated IFP and lowered ECV that correlated with a more fibrotic ECM, underlining the role of the collagen network for carcinoma physiology.
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11.
  • Hamnerius, Yngve, 1950, et al. (författare)
  • Evaluating exposure from electric fields in a high voltage switchyard according to the EU directive
  • 2019
  • Ingår i: Journal of Radiological Protection. - : IOP Publishing. - 1361-6498 .- 0952-4746. ; 39:1, s. 150-160
  • Tidskriftsartikel (refereegranskat)abstract
    • An assessment according to Directive 2013/35/EU of exposure in a 400 kV switchyard has been performed. Part of the body was exposed to electric field strength above the high action level. We therefore performed simulations of the electric fields induced in the body to assess these accoding to the exposure limit values (ELVs). The simulations show that as long as the body is not grounded nor touching any grounded metallic objects, worker exposure is compliant with the directive. When grounded metallic objects are touched with hand or foot the ELV are exceeded. The ELV is exceeded already at very low contact currents (2-3 mu A) in the finger. If not appropriate measures are taken, this would lead to a severe limitation of the work tasks that can be performed in switchyards.
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12.
  • Karén, Jakob, 1973-, et al. (författare)
  • Defining the pericyte to fibroblast lineage
  • Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
    • In the present study placental tissues were characterized in vivo with regards to markers expressed on pericytes, fibroblasts and collagen type I synthesis. Microvascular fragments (MVFs) isolated from human placentas had a phenotypical marker profile consistent with microvessels in situ. Cells emerging from MVFs from placenta express a marker profile consistent with a pericyte phenotype. Temporal studies identified three optimal time points (T0, T1 and T2) subsequent to the onset of cells emerging from MVFs for further analysis with regards to divergence in marker expression profiles. T0, T1 and T2 time points contained a population of cells with a cellular phenotype consistent with mesenchymal stem/progenitor cells, activated microvascular pericytes and mature connective tissue cells. Three discernable subpopulations of cells were identified i.e. Stro-1+/CD146+/podoplanin-, Stro-1-/CD146+/podoplanin- and Stro-1-/CD146-/podoplanin+ cells. Flow cytometry analysis allowed for the Stro-1-/CD146+/podoplanin- and Stro-1-/CD146-/podplanin+ cell populations to be further divided into 2 subgroups based on the expression of desmin, αSMA and TE-7. Five steps in the differentiation process from mesenchymal stem/progenitor cell to collagen type I producing fibroblast and the order by which they progressed could be defined by re-diversification studies i.e. ability of one population of cells to give rise to the other population of cells. Two in vivo experimental systems, TPA induced inflammation and excisional cutaneous wound healing were analyzed for the existence of slow cycling cells. The in vivo evidence shows that microvascular pericytes constitute a reservoir of stem/progenitor cells for pro-fibrotic connective tissue cells. This study presents novel evidence for a connective tissue cell lineage originating from a undifferentiated mesenchymal vessel associated cell population that via pericytes differentiate into pro-fibrotic fibroblasts.
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13.
  • Karén, Jakob, 1973-, et al. (författare)
  • Effects of the HDAC inhibitor valproic acid on human pericytes in vitro
  • Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
    • Microvasculare pericytes are of key importance in neoformation of blood vessels, in stabilization of newly formed vessels as well as maintenance of angiostasis in resting tissues. In the present study the effects of the HDAC inhibitor VPA on pericyte proliferation, migration and differentiation was investigated. Furthermore, expression of genes known to be involved in different aspects of angiogenesis were investigated in primary pericyte cultures as well as the effects of VPA on the expression of these set of genes using quantative PCR arrays. The results show that HDAC inhibition leads to inhibition of pericyte proliferation and migration as well as pericyte differentiation into collagen type I producing fibroblasts. Furthermore, HDAC inhibition promoted expression of mRNAs of genes involved in vessel stabilization/maturation in human microvascular pericytes. The present study suggests that VPAs effect on angiogenesis via microvascular pericytes is through vessel stabilization.
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14.
  • Karén, Jakob, et al. (författare)
  • Effects of the histone deacetylase inhibitor valproic Acid on human pericytes in vitro
  • 2011
  • Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:9, s. e24954-
  • Tidskriftsartikel (refereegranskat)abstract
    • Microvascular pericytes are of key importance in neoformation of blood vessels, in stabilization of newly formed vessels as well as maintenance of angiostasis in resting tissues. Furthermore, pericytes are capable of differentiating into pro-fibrotic collagen type I producing fibroblasts. The present study investigates the effects of the histone deacetylase (HDAC) inhibitor valproic acid (VPA) on pericyte proliferation, cell viability, migration and differentiation. The results show that HDAC inhibition through exposure of pericytes to VPA in vitro causes the inhibition of pericyte proliferation and migration with no effect on cell viability. Pericyte exposure to the potent HDAC inhibitor Trichostatin A caused similar effects on pericyte proliferation, migration and cell viability. HDAC inhibition also inhibited pericyte differentiation into collagen type I producing fibroblasts. Given the importance of pericytes in blood vessel biology a qPCR array focusing on the expression of mRNAs coding for proteins that regulate angiogenesis was performed. The results showed that HDAC inhibition promoted transcription of genes involved in vessel stabilization/maturation in human microvascular pericytes. The present in vitro study demonstrates that VPA influences several aspects of microvascular pericyte biology and suggests an alternative mechanism by which HDAC inhibition affects blood vessels. The results raise the possibility that HDAC inhibition inhibits angiogenesis partly through promoting a pericyte phenotype associated with stabilization/maturation of blood vessels.
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15.
  • Olof Olsson, P., et al. (författare)
  • Inhibition of integrin αvβ6 changes fibril thickness of stromal collagen in experimental carcinomas
  • 2018
  • Ingår i: Cell Communication and Signaling. - : Springer Science and Business Media LLC. - 1478-811X. ; 16:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Chemotherapeutic efficacy can be improved by targeting the structure and function of the extracellular matrix (ECM) in the carcinomal stroma. This can be accomplished by e.g. inhibiting TGF-β1 and -β3 or treating with Imatinib, which results in scarcer collagen fibril structure in xenografted human KAT-4/HT29 (KAT-4) colon adenocarcinoma. Methods: The potential role of αVβ6 integrin-mediated activation of latent TGF-β was studied in cultured KAT-4 and Capan-2 human ductal pancreatic carcinoma cells as well as in xenograft carcinoma generated by these cells. The monoclonal αVβ6 integrin-specific monoclonal antibody 3G9 was used to inhibit the αVβ6 integrin activity. Results: Both KAT-4 and Capan-2 cells expressed the αVβ6 integrin but only KAT-4 cells could utilize this integrin to activate latent TGF-β in vitro. Only when Capan-2 cells were co-cultured with human F99 fibroblasts was the integrin activation mechanism triggered, suggesting a more complex, fibroblast-dependent, activation pathway. In nude mice, a 10-day treatment with 3G9 reduced collagen fibril thickness and interstitial fluid pressure in KAT-4 but not in the more desmoplastic Capan-2 tumors that, to achieve a similar effect, required a prolonged 3G9 treatment. In contrast, a 10-day direct inhibition of TGF-β1 and -β3 reduced collagen fibril thickness in both tumor models. Conclusion: Our data demonstrate that the αVβ6-directed activation of latent TGF-β plays a pivotal role in modulating the stromal collagen network in carcinoma, but that the sensitivity to αVβ6 inhibition depends on the simultaneous presence of alternative paths for latent TGF-β activation and the extent of desmoplasia.
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16.
  • Olsson, Olof, et al. (författare)
  • The Tyrosine Kinase Inhibitor Imatinib Augments Extracellular Fluid Exchange and Reduces Average Collagen Fibril Diameter in Experimental Carcinoma
  • 2016
  • Ingår i: Molecular Cancer Therapeutics. - 1535-7163 .- 1538-8514. ; 15:10, s. 2455-2464
  • Tidskriftsartikel (refereegranskat)abstract
    • A typical obstacle to cancer therapy is the limited distribution of low molecular weight anticancer drugs within the carcinoma tissue. In experimental carcinoma, imatinib (STI571) increases efficacy of synchronized chemotherapy, reduces tumor interstitial fluid pressure, and increases interstitial fluid volume. STI571 also increases the water-perfusable fraction in metastases from human colorectal adenocarcinomas. Because the mechanism(s) behind these effects have not been fully elucidated, we investigated the hypothesis that STI571 alters specific properties of the stromal extracellular matrix. We analyzed STI571-treated human colorectal KAT-4/HT-29 experimental carcinomas, known to have a well-developed stromal compartment, for solute exchange and glycosaminoglycan content, as well as collagen content, structure, and synthesis. MRI of STI571-treated KAT-4/HT-29 experimental carcinomas showed a significantly increased efficacy in dynamic exchanges of solutes between tumor interstitium and blood. This effect was paralleled by a distinct change of the stromal collagen network architecture, manifested by a decreased average collagen fibril diameter, and increased collagen turnover. The glycosaminoglycan content was unchanged. Furthermore, the apparent effects on the stromal cellular composition were limited to a reduction in an NG2-positive stromal cell population. The current data support the hypothesis that the collagen network architecture influences the dynamic exchanges of solutes between blood and carcinoma tissue. It is conceivable that STI571 reprograms distinct nonvascular stromal cells to produce a looser extracellular matrix, ultimately improving transport characteristics for traditional chemotherapeutic agents.
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17.
  • Olsson, P. Olof, et al. (författare)
  • Inhibition of integrin alpha(V)beta(6) changes fibril thickness of stromal collagen in experimental carcinomas
  • 2018
  • Ingår i: Cell Communication and Signaling. - : BMC. - 1478-811X. ; 16
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Chemotherapeutic efficacy can be improved by targeting the structure and function of the extracellular matrix (ECM) in the carcinomal stroma. This can be accomplished by e.g. inhibiting TGF beta 1 and -beta 3 or treating with Imatinib, which results in scarcer collagen fibril structure in xenografted human KAT-4/HT29 (KAT-4) colon adenocarcinoma.Methods: The potential role of a(v)beta(6) integrin-mediated activation of latent TGF-beta was studied in cultured KAT-4 and Capan-2 human ductal pancreatic carcinoma cells as well as in xenograft carcinoma generated by these cells. The monoclonal a(v)beta(6) integrin-speafic monoclonal antibody 3G9 was used to inhibit the a(v)beta(6) integrin activity.Results: Both KAT-4 and Capan-2 cells expressed the a(v)beta(6) integrin but only KAT-4 cells could utilize this integrin to activate latent TGF-beta in vitro. Only when Capan-2 cells were co-cultured with human F99 fibroblasts was the integrin activation mechanism triggered, suggesting a more complex, fibroblast-dependent, activation pathway. In nude mice, a 10-day treatment with 3G9 reduced collagen fibril thickness and interstitial fluid pressure in KAT-4 but not in the more desmoplastic Capan-2 tumors that, to achieve a similar effect, required a prolonged 3G9 treatment. In contrast, a 10-day direct inhibition of TGF-beta 1 and -beta 3 reduced collagen fibril thickness in both tumor models.Conclusion: Our data demonstrate that the a(v)beta(6)-directed activation of latent TGF-beta plays a pivotal role in modulating the stromal collagen network in carcinoma, but that the sensitivity to a(v)beta(6) inhibition depends on the simultaneous presence of alternative paths for latent TGF-beta activation and the extent of desmoplasia.
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18.
  • Rodriguez, Alejandro, et al. (författare)
  • Phenotypical differences in connective tissue cells emerging from microvascular pericytes in response to over-expression of PDGF-B and TGF-beta in normal skin in vivo
  • 2013
  • Ingår i: American Journal of Pathology. - : Elsevier BV. - 0002-9440 .- 1525-2191. ; 182:6, s. 2132-2146
  • Tidskriftsartikel (refereegranskat)abstract
    • Fibrosis is a deleterious consequence of chronic inflammation in a number of human pathological states ultimately leading to, if not perturbed to organ dysfunction and failure. Two key processes in fibrosis are activation of blood vessels and connective tissue cells leading to excess deposition of ECM components; collagen type I being the most abundant. In the present study the effects of two growth factors known to be important in the fibrotic process, namely PDGF-B and TGF-β1, were studied. Adenoviral vectors engineered to express PDGF-B or TGF-β1 were introduced into mouse skin thereby inducing a transient over-expression of either growth factor. After 3, 7 and 14 days post injection, tissues were harvested and morphology and protein expression were examined on plastic embedded 1 µm thick sections and by immunohistochemistry on frozen sections, respectively. Over-expression of both TGF-β1 and PDGF-B lead to a fibrotic response consisting of a marked macrophage influx as well as an expansion of the connective tissue cell population. In both conditions the latter originated from microvascular pericytes. The resulting phenotype of the emerging connective tissue cell population differed between PDGF-B and TGF-β1 treated skin.  In tissues over expressing PDGF-B but not TGF-β1 the fibrotic process was partially reversible. Both growth factors were able to initiate, but neither were able to sustain the process of angiogenesis, which lead to vascular regression. PDGF-B but not TGF-β1 was able to stimulate but not maintain a distinct form of angiogenesis i.e. glomeruloid body formation. In conclusion, over-expression of PDGF-B and TGF-β1 in normal skin resulted in the emergence of connective tissue cells differing in their phenotype, originating in both cases from a common cell namely the microvascular pericyte. Therefore the vasculature and the fibrotic process are linked in a previously unrecognized way.
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19.
  • Santoro, V., et al. (författare)
  • HighNESS conceptual design report: Volume I
  • 2024
  • Ingår i: Journal of Neutron Research. - 1023-8166 .- 1477-2655. ; 25:3-4, s. 85-314
  • Tidskriftsartikel (refereegranskat)abstract
    • The European Spallation Source, currently under construction in Lund, Sweden, is a multidisciplinary international laboratory. Once completed to full specifications, it will operate the world’s most powerful pulsed neutron source. Supported by a 3 million Euro Research and Innovation Action within the EU Horizon 2020 program, a design study (HighNESS) has been completed to develop a second neutron source located below the spallation target. Compared to the first source, designed for high cold and thermal brightness, the new source has been optimized to deliver higher intensity, and a shift to longer wavelengths in the spectral regions of cold (CN, 2–20 Å), very cold (VCN, 10–120 Å), and ultracold (UCN, >500 Å) neutrons. The second source comprises a large liquid deuterium moderator designed to produce CN and support secondary VCN and UCN sources. Various options have been explored in the proposed designs, aiming for world-leading performance in neutronics. These designs will enable the development of several new instrument concepts and facilitate the implementation of a high-sensitivity neutron-antineutron oscillation experiment (NNBAR). This document serves as the Conceptual Design Report for the HighNESS project, representing its final deliverable.
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20.
  • Sedigh, Amir (författare)
  • Management of Ischemia and Brain Death-Associated Injuries in Porcine Kidney Grafts
  • 2014
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Organs from deceased donors after brain death (BD) remain the major source of organs for transplantation. The catastrophic event of BD and the inevitable consequences of ischemia reperfusion injury (IRI) are linked to impaired graft quality and transplantation outcome. The aim of this thesis was to create a BD model in pigs to assess early effects on IRI in kidneys preserved with an oxygenated solution and to evaluate the protective effects of coating the renal vessel walls with a heparin conjugate during hypothermic machine perfusion (HMP).Brain death was achieved by raising the intracranial pressure (ICP) through stepwise increasing the volume of an epidurally placed balloon to the point of exceeding the mean arterial pressure (MAP) creating a negative cerebral perfusion pressure (CPP). This reproducible, clinically relevant experimental model makes evaluation of potential targeted methods to protect the organs possible. Kidneys retrieved from brain-dead pigs were preserved either in an oxygenated emulsion composed of 75% histidine-tryptophan-ketoglutarate (HTK) and 25% perfluorohexyloctane F6H8 or HTK alone. After 18h of cold storage the kidneys were transplanted into allogeneic pigs. F6H8 was associated with replenishment of adenosine triphosphate and lower gene expression of hypoxia inducible factor (HIF)-1a, vascular endothelial growth factor (VEGF), interleukin (IL)-1α and tumour necrosis factor (TNF)-α. F6H8 reduced early IRI at both the cellular and molecular level.Kidneys from BD pigs were evaluated for the feasibility of coating the vessel walls with the heparin conjugate CHC (Corline Systems AB, Uppsala, Sweden) to restore glycocalyx. Porcine kidneys were preserved by HMP for 20h with 50 mg biotinylated CHC added to the perfusion solution. CHC was detected on the inner surface of the kidney vessels by immunofluorescence, and its uptake in kidneys was confirmed by reduced content in the perfusate. An ex vivo normothermic perfusion circuit was developed to assess kidney function. Perfusion with CHC during HMP was associated with lower creatinine levels, increased urine volume and reduced tubular injury. Modifying renal vessels walls using CHC during HMP improved early graft function. Preservation with the oxygenated F6H8 solution or CHC could be used to improve graft quality and ameliorate IRI in kidneys retrieved from deceased donors.
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21.
  • Sundberg, Christian, et al. (författare)
  • Two different PDGF beta-receptor cohorts in human pericytes mediate distinct biological endpoints
  • 2009
  • Ingår i: American Journal of Pathology. - : Elsevier BV. - 0002-9440 .- 1525-2191. ; 175:1, s. 171-189
  • Tidskriftsartikel (refereegranskat)abstract
    • How activation of a specific growth factor receptor selectively results in either cell proliferation or cytoskeletal reorganization is of central importance to the field of pathophysiology. In this study, we report on a novel mechanism that explains how this process is accomplished. Our current investigation demonstrates that soluble platelet derived growth factor- (PDGF)-BB activates a cohort of PDGF-beta receptors primarily confined to the lipid raft component of the cell membrane, specifically caveolae. In contrast, cell-bound PDGF-BB delivered via cell-cell contact results in activation and the subsequent up-regulation of a cohort of PDGF beta-receptors primarily confined to the non-lipid raft component of the cell membrane. Individual activation of these two receptor cohorts results in distinct biological endpoints, cytoskeletal reorganization or cell proliferation. Mechanistically, our evidence suggests that PDGF-BB-bearing cells preferentially stimulate the non-lipid raft receptor cohort through interleukin 1beta-mediated inhibition of the lipid raft cohort of receptors, leaving the non-raft receptor cohort operational and preferentially stimulated. In human skin injected with PDGF-BB and in tissue reparative processes PDGF beta-receptors colocalize with the caveolae/lipid raft marker caveolin-1. In contrast, in human skin injected with PDGF-BB-bearing tumor cells and in colorectal adenocarcinoma, activated PDGF beta-receptors do not colocalize with caveolin-1. Thus, growth factor receptors are segregated into specific cell membrane compartments that are preferentially activated through different mechanisms of ligand delivery, resulting in distinct biological endpoints.
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