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| 2. |
- Aldi, Silvia, et al.
(författare)
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Dual roles of heparanase in human carotid plaque calcification
- 2019
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Ingår i: Atherosclerosis. - : ELSEVIER IRELAND LTD. - 0021-9150 .- 1879-1484. ; 283, s. 127-136
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Tidskriftsartikel (refereegranskat)abstract
- Background and aims: Calcification is a hallmark of advanced atherosclerosis and an active process akin to bone remodeling. Heparanase (HPSE) is an endo-beta-glucuronidase, which cleaves glycosaminoglycan chains of heparan sulfate proteoglycans. The role of HPSE is controversial in osteogenesis and bone remodeling while it is unexplored in vascular calcification. Previously, we reported upregulation of HPSE in human carotid endarterectomies from symptomatic patients and showed correlation of HPSE expression with markers of inflammation and increased thrombogenicity. The present aim is to investigate HPSE expression in relation to genes associated with osteogenesis and osteolysis and the effect of elevated HPSE expression on calcification and osteolysis in vitro.Methods: Transcriptomic and immunohistochemical analyses were performed using the Biobank of Karolinska Endarterectomies (BiKE). In vitro calcification and osteolysis were analysed in human carotid smooth muscle cells overexpressing HPSE and bone marrow-derived osteoclasts from HPSE-transgenic mice respectively.Results: HPSE expression correlated primarily with genes coupled to osteoclast differentiation and function in human carotid atheromas. HPSE was expressed in osteoclast-like cells in atherosclerotic lesions, and HPSE-transgenic bone marrow-derived osteoclasts displayed a higher osteolytic activity compared to wild-type cells. Contrarily, human carotid SMCs with an elevated HPSE expression demonstrated markedly increased mineralization upon osteogenic differentiation.Conclusions: We suggest that HPSE may have dual functions in vascular calcification, depending on the stage of the disease and presence of inflammatory cells. While HPSE plausibly enhances mineralization and osteogenic differentiation of vascular smooth muscle cells, it is associated with inflammation-induced osteoclast differentiation and activity in advanced atherosclerotic plaques.
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| 3. |
- Corbascio, Matthias, et al.
(författare)
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Anti-lymphocyte function-associated antigen-1 monoclonal antibody inhibits CD40 ligand-independent immune responses and prevents chronic vasculopathy in CD40 ligand-deficient mice.
- 2002
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Ingår i: Transplantation. - 1534-6080. ; 74:1, s. 35-41
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Blockade of CD40 ligand (CD40L; CD154, gp39) is a potential treatment for autoimmune disease and allograft rejection. However, CD40L-/- mice are capable of mobilizing cellular immune responses to viral, parasitic, and intracellular bacterial infections as well as rejecting skin grafts with nearly the same efficiency as wild-type mice. CD40L-deficient mice (CD40L-/-) or wild-type mice treated with anti-CD40L develop chronic vasculopathy only 8 weeks after allogeneic heart transplantation. To overcome CD40L-independent immune responses, we used anti-lymphocyte function-associated antigen monoclonal antibody (LFA)-1, which has previously been shown to inhibit CD8+ immune responses. METHODS: We conducted mixed lymphocyte reactions, cytotoxicity assays, skin transplantation, and vascularized heterotopic heart transplantation in wild-type B6 and CD40L-deficient mice in the presence and absence of anti-LFA-1 to study the effects of anti-LFA-1 in the absence of CD40L signaling. RESULTS: Anti-LFA-1 inhibited proliferation of naïve CD40L-/- mixed leukocyte reactions and the lysis of donor targets by CD40L-/- cytotoxic T lymphocytes. Anti-LFA-1-treated CD40L-/- mice that received fully MHC-mismatched skin grafts showed significant prolongation of graft survival, with a median survival time of 55 days (mean 66 days) compared with 13 and 21 days in wild-type and CD40L-/- controls, respectively. CD40L-/- mice that received fully MHC-mismatched vascularized heart transplants treated with four doses of 200 microg of anti-LFA-1 at the time of transplantation did not develop any signs of chronic vasculopathy 150 days after transplantation. CONCLUSION: These results indicate that anti-LFA-1 can complement CD40L inhibition in the prevention of undesirable immune responses.
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| 4. |
- Corbascio, Matthias, et al.
(författare)
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CTLA4Ig combined with anti-LFA-1 prolongs cardiac allograft survival indefinitely.
- 2002
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Ingår i: Transplant Immunology. - 1878-5492. ; 10:1, s. 55-61
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Tidskriftsartikel (refereegranskat)abstract
- CTLA4Ig and anti-LFA-1 are members of a new generation of immunomodulatory drugs which inhibit important signaling pathways in T cell activation. Both substances target molecules which have pivitol functions in the activation of CD4+ and CD8+ T cells and have been theorized to have an interdependent relationship. These drugs have been used independently in various treatment regimens and have shown great promise in prolonging the survival of allografts. In order to test whether these substances have synergistic or potentiating effects when combined, we performed mixed lymphocyte reactions, skin transplantation and vascularised heterotopic heart transplantation in the Balb/c (H-2(d)) to C3H/HeJ (H-2(k)) strain combination. When anti-LFA-1 and CTLA4Ig were combined at low doses, there was a substantial inhibition of lymphocyte proliferation. When each drug was used as a mono-therapy in skin graft recipients, there was no significant effect on median graft survival (anti-LFA-1, 15 days; CTLA4Ig, 16 days) when compared to untreated controls (13 days), whereas a combination of anti-LFA-1 and CTLA4Ig extended graft survival significantly to 32 days. Untreated vascularised heart grafts rejected at a median of 8 days, CTLA4Ig-treated mice rejected at a median time of 79 days and anti-LFA-1-treated mice rejected at 43 days (n = 9). When CTLA4Ig and anti-LFA-1 were combined, all animals had functioning heart grafts at 100 days after transplantation. Histological analysis of combined-therapy hearts showed no signs or only minor changes associated with chronic rejection. In conclusion, these results indicate a synergistic effect of combining anti-LFA-1 with CTLA4Ig in inhibiting lymphocyte proliferation and prolonging the survival of fully MHC-mismatched allografts.
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| 5. |
- Grinnemo, Karl-Henrik, et al.
(författare)
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Immunomodulatory effects of interferon-gamma on human fetal cardiac mesenchymal stromal cells
- 2019
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Ingår i: Stem Cell Research & Therapy. - : BMC. - 1757-6512. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Background: Mesenchymal stromal cells (MSCs), due to their regenerative and immunomodulatory properties, are therapeutically used for diseases, including heart failure. As early gestational-phase embryonic tissues exhibit extraordinary regenerative potential, fetal MSCs exposed to inflammation offer a unique opportunity to evaluate molecular mechanisms underlying preferential healing, and investigate their inherent abilities to communicate with the immune system during development. The principal aim of this study was to evaluate the effects of interferon-gamma (IFN gamma) on the immunomodulatory effects of first-trimester human fetal cardiac (hfc)-MSCs.Methods: hfcMSCs (gestational week 8) were exposed to IFN gamma, with subsequent analysis of the whole transcriptome, based on RNA sequencing. Exploration of surface-expressed immunoregulatory mediators and modulation of T cell responses were performed by flow cytometry. Presence and activity of soluble mediators were assessed by ELISA or high-performance liquid chromatography.Results: Stimulation of hfcMSCs with IFN gamma revealed significant transcriptional changes, particularly in respect to the expression of genes belonging to antigen presentation pathways, cell cycle control, and interferon signaling. Expression of immunomodulatory genes and associated functional changes, including indoleamine 2,3-dioxygenase activity, and regulation of T cell activation and proliferation via programmed cell death protein (PD)-1 and its ligands PD-L1 and PD-L2, were significantly upregulated. These immunoregulatory molecules diminished rapidly upon withdrawal of inflammatory stimulus, indicating a high degree of plasticity by hfcMSCs.Conclusions: To our knowledge, this is the first study performing a systematic evaluation of inflammatory responses and immunoregulatory properties of first-trimester cardiac tissue. In summary, our study demonstrates the dynamic responsiveness of hfcMSCs to inflammatory stimuli. Further understanding as to the immunoregulatory properties of hfcMSCs may be of benefit in the development of novel stromal cell therapeutics for cardiovascular disease.
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| 6. |
- Malm, Helene, et al.
(författare)
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CTLA4ig induces long-term graft survival of allogeneic skin grafts and totally inhibits T-cell proliferation in LFA-1-deficient mice.
- 2002
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Ingår i: Transplantation. - 1534-6080. ; 73:2, s. 293-297
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: It was recently shown that some strains of mice are capable of rejecting transplants independently of B7 and CD40L signaling and that this rejection is mediated by CD8(+) T cells. LFA-1 is known to be important for CD8(+) T cell activation and cytotoxicity. Therefore, blockade of LFA-1 could be important in overcoming costimulation blockade, CD8(+) T-cell-mediated, resistant rejection. The purpose of this study was to define the effect of combined blockade of the LFA-1 and B7 costimulation pathways on the alloimmune response in mice. METHODS: Allogeneic skin transplantation was performed using BALB/c mice as donors and C57BL/6J wild-type or LFA-1-deficient (CD11a(-/-)) mice as recipients. CTLA4Ig or anti-LFA-1 was administered either as an induction or a prolonged therapy. Mixed lymphocyte reactions were conducted to study the effect of CTLA4Ig on T-cell proliferation in CD11a(-/-) mice. RESULTS AND CONCLUSIONS: Administration of CTLA4Ig completely inhibits CD11a(-/-) T-cell proliferation in response to alloantigens and significantly improved skin allograft survival in CD11a(-/-) mice. Prolonged treatment of wild-type recipient mice with CTLA4Ig and anti-LFA-1 increased median survival time to 45.5 days compared with 16 days after induction therapy, but it was not sufficient to induce indefinite allograft survival in this model.
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| 7. |
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| 8. |
- Perisic, L., et al.
(författare)
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Profiling of atherosclerotic lesions by gene and tissue microarrays reveals pcsk6 as a novel protease in unstable carotid atherosclerosis
- 2013
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Ingår i: Arteriosclerosis, Thrombosis and Vascular Biology. - 1079-5642 .- 1524-4636. ; 33:10, s. 2432-2443
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE - : Carotid plaque instability is a major cause of ischemic stroke, but detailed knowledge about underlying molecular pathways is still lacking. Here, we evaluated large-scale transcriptomic and protein expression profiling in a biobank of carotid endarterectomies followed by characterization of identified candidates, as a platform for discovery of novel proteins differentially regulated in unstable carotid lesions. APPROACH AND RESULTS - : Genes highly upregulated in symptomatic versus asymptomatic plaques were selected from Affymetrix microarray analyses (n=127 plaques), and tissue microarrays constructed from 34 lesions were assayed for 21 corresponding proteins by immunohistochemistry. Quantification of stainings demonstrated differential expression of CD36, CD137, and DOCK7 (P<0.05) in unstable versus stable lesions and the most significant upregulation of a proprotein convertase, PCSK6 (P<0.0001). Increased expression of PCSK6 in symptomatic lesions was verified by quantitative real-time polymerase chain reaction (n=233), and the protein was localized to smooth muscle α-actin positive cells and extracellular matrix of the fibrous cap by immunohistochemistry. PCSK6 expression positively correlated to genes associated with inflammation, matrix degradation, and mitogens in microarrays. Stimulation of human carotid smooth muscle cells in vitro with cytokines caused rapid induction of PCSK6 mRNA. CONCLUSIONS - : Using a combination of transcriptomic and tissue microarray profiling, we demonstrate a novel approach to identify proteins differentially expressed in unstable carotid atherosclerosis. The proprotein convertase PCSK6 was detected at increased levels in the fibrous cap of symptomatic carotid plaques, possibly associated with key processes in plaque rupture such as inflammation and extracellular matrix remodeling. Further studies are needed to clarify the role of PCSK6 in atherosclerosis.
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| 9. |
- Österholm, C., et al.
(författare)
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Increased expression of heparanase in symptomatic carotid atherosclerosis
- 2013
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Ingår i: Atherosclerosis. - : Elsevier BV. - 0021-9150 .- 1879-1484. ; 226:1, s. 67-73
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Proliferation of smooth muscle cells (SMCs) can stabilize atherosclerotic lesions but the molecular mechanisms that regulate this process in humans are largely unknown. We have previously shown that heparan sulfate proteoglycans (HSPGs), such as perlecan, regulate SMC growth in animal models by modulating heparin-binding mitogens. Since perlecan is expressed at low levels in human atherosclerosis, we speculated that the effect of heparan sulfate (HS) in human disease was rather influenced by HS degradation and investigated the expression of heparanase (HPSE) in human carotid endarterectomies. Methods and results: Gene expression analysis from 127 endarterectomies in the BiKE database revealed increased expression of HPSE in carotid plaques compared with normal arteries, and a further elevation in symptomatic lesions. Increased HPSE protein expression in symptomatic plaque tissue was verified by tissue microarrays. HPSE mRNA levels correlated positively with expression of inflammatory markers IL-18, RANTES and IL-1β, and also T-cell co-stimulatory molecules, such as B7.2, CD28, LFA-1 and 4-1BB. Previously reported single nucleotide polymorphisms within HPSE were associated with differential mRNA expression in plaques. Immunohistochemistry revealed that inflammatory cells were major producers of HPSE in plaque tissue. HPSE immunoreactivity was also observed in SMCs adjacent to the necrotic core and was co-localized to deposits of fibrin. Conclusions: This study demonstrates increased expression of HPSE in human atherosclerosis associated with inflammation, coagulation and plaque instability. Since HS can regulate SMC proliferation and influence plaque stability, the findings suggest that HPSE degradation of HS take part in the regulation of SMC function in human atherosclerosis.
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