Antisense oligonucleotide targeting of thrombopoietin represents a novel platelet depletion method to assess the immunomodulatory role of platelets

2020 ◽  
Vol 18 (7) ◽  
pp. 1773-1782
Author(s):  
Tessa J. Barrett ◽  
Benjamin G. Wu ◽  
Alexey S. Revenko ◽  
A. Robert MacLeod ◽  
Leopoldo N. Segal ◽  
...  
Keyword(s):  
Antisense Oligonucleotide ◽  
Platelet Depletion

Suppression of the glutamate receptor delta 2 subunit produces a specific impairment in cerebellar long-term depression

1996 ◽  
Vol 76 (5) ◽  
pp. 3578-3583 ◽  
Author(s):  
A. Jeromin ◽  
R. L. Huganir ◽  
D. J. Linden
Keyword(s):  
Glutamate Receptor ◽  
Antisense Oligonucleotide ◽  
Metabotropic Glutamate Receptors ◽  
Metabotropic Glutamate Receptor ◽  
Calcium Influx ◽  
Long Term Depression ◽  
Metabotropic Glutamate ◽  
Flow Through

1. The role of the glutamate receptor subunit delta 2 in the induction of cerebellar long-term depression (LTD) was investigated by application of antisense oligonucleotides. The delta 2 subunit is selectively localized to Purkinje cells (PCs), with the highest levels being in the PC dendritic spines, where parallel fibers are received and where cerebellar LTD is expressed. 2. Immunocytochemical analysis of calbindin-positive PCs revealed that both the dendritic and somatic expression of delta 2 was reduced in antisense-but not in sense-treated cultures. An antisense oligonucleotide directed against the related subunit delta 1 did not affect the expression of delta 2 in PCs. 3. Cerebellar LTD may be reliably induced in a preparation of cultured embryonic cerebellar neurons from the mouse when parallel and climbing fiber stimulation are replaced by brief glutamate pulses and strong, direct depolarization of the PC, respectively. Application of an antisense oligonucleotide directed against delta 2 completely blocked the induction of LTD produced by glutamate/ depolarization conjunctive stimulation. A delta 2 sense oligonucleotide or an antisense oligonucleotide directed against the related delta 1 subunit had no effect. 4. The effect of the delta 2 antisense oligonucleotide was not related to attenuation of calcium influx via voltage-gated channels or calcium mobilization via metabotropic glutamate receptors, as assessed with fura-2 microfluorimetry. Current flow through alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-receptor-associated ion channels also appeared unaltered. All three of these processes have previously been shown to be required for cerebellar LTD induction. The observation that delta 2 is involved in a metabotropic-glutamate-receptor-independent signaling pathway that is required for LTD induction supports the view that delta 2 participates in the formation of a novel postsynaptic receptor complex.

Regulation of PAI-1 Concentration in Platelets by Systemic Administration of Antisense Oligonucleotides to Rats

2001 ◽  
Vol 85 (06) ◽  
pp. 1086-1089 ◽  
Author(s):  
Zofia Pawlowska ◽  
Ewa Chabielska ◽  
Anna Kobylanska ◽  
Anna Maciaszek ◽  
Maria Swiatkowska ◽  
...  
Keyword(s):  
Antisense Oligonucleotide ◽  
Antisense Oligonucleotides ◽  
Low Doses ◽  
Significant Delay ◽  
Occlusion Time ◽  
Antisense Approach ◽  
First Time ◽  
Pai 1 ◽  
Arterial Thrombolysis

SummaryIn this report we tested the effect of oligodeoxyribonucleotides antisense to PAI-1 mRNA administered into rats on PAI-1 concentration in platelets. Low doses of the antisense oligonucleotide (MPO-16R) reduced PAI-1 activity, both in rat blood plasma and platelet lysates by 20.5% and 28.7%, respectively. There was no change in platelet count after treatment with MPO-16R but treated platelets showed lower aggregability as compared with controls (37 ± 13% and 54 ± 12%, respectively). In an experimental model of rat arterial thrombosis, low doses of MPO-16R caused a significant delay in the occlusion time (31.8%). These data further support for the role of PAI-1 as a major determinant of arterial thrombolysis resistance and for the first time demonstrate the possibility of reduction of platelet PAI-1 concentration by antisense approach.

Platelets Protect From Lipopolysaccharide-Induced Lethal Endotoxemia by Inhibiting Macrophage-Dependent Inflammation Via the Cyclooxygenase 1 (COX1) Signaling Pathway

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 93-93
Author(s):  
Binggang Xiang ◽  
Guoying Zhang ◽  
Xiang-An Li ◽  
Andrew J. Morris ◽  
Alan Daugherty ◽  
...  
Keyword(s):  
Septic Shock ◽  
Platelet Transfusion ◽  
Conflicts Of Interest ◽  
Plasma Concentrations ◽  
Platelet Inhibition ◽  
Severe Thrombocytopenia ◽  
Wild Type ◽  
Activated Platelets ◽  
Platelet Depletion

Abstract Abstract 93 Sepsis is a tremendous burden for health-care systems. Patients with sepsis often have low platelet counts, and septic patients with severe thrombocytopenia have a poor prognosis and higher mortality. However, the role of platelets in the pathogenesis of sepsis has not been well elucidated. We investigated the role of platelets in septic shock using a mouse model of lipopolysaccharide (LPS)-induced endotoxemia. Depletion of platelets by intraperitoneal injection of a rat anti-mouse GPIb monoclonal antibody increased mortality and aggravated organ failure in endotoxemic mice as evident by increases in plasma aminotransferase (ALT), aspartate aminotransferase (AST), Lactate dehydrogenase (LDH), and Creatine kinase (CK) concentrations, while transfusion of platelets reduced mortality. Increases in mortality rate in thrombocytopenic mice by LPS challenge was not due to inflammatory hemorrhage, because there was no significantly hemorrhage observed in brains and lungs from mice pre-treated with either control IgG or the anti-GPIba antibody and blood RBC and Hb concentrations between IgG pre-treated mice and the anti-GPIba antibody pre-treated mice were similar. TNF-a, which is produced mainly by macrophages in vivo, plays critical roles in the development of disseminated intravascular coagulation, acute respiratory distress syndrome and shock in sepsis. Our data indicate that plasma concentrations of proinflammatory cytokines, TNF-a and IL-6, were markedly increased by platelet depletion and decreased by platelet transfusion in the mice challenged with LPS. Effects of platelet depletion on TNF-a production were eliminated in the mice that macrophages were pre-depleted. Furthermore, LPS- or thrombin-activated platelets or releasates from activated platelets inhibited TNF-a and IL-6 production in macrophages in vitro. Inhibition of TNF-a and IL-6 production in macrophages by activated platelets was prevented by pre-incubation of platelets with a COX1 inhibitor aspirin. Moreover, platelets from wild type mice but not COX1 deficient mice inhibited LPS-induced TNF-a and IL-6 production in macrophages. Transfusion of COX1 deficient platelets failed to protect against endotoxemia. Washed platelets from wild-type mice or platelet releasates from thrombin-activated wild-type mice inhibited LPS-induced TNF-a and IL-6 production in macrophages lacking TXA2 receptor, TP, suggesting that a metabolite other than TXA2 is responsible for platelet inhibition of macrophage function. We found that stimulation of platelets with thrombin or LPS induced PGE2 production and pre-incubation of macrophages with an antagonist of PGE2 receptor EP4 reversed platelet inhibition on TNF-a and IL-6 production in macrophages. Our results indicate that platelets protect against septic shock by inhibiting macrophage-dependent inflammatory response via the COX1/PGE2/EP4 dependent pathway. Thus, these findings demonstrate a previously unappreciated role for platelets in septic shock and suggest that platelet transfusion may be effective in treating septic patients. Disclosures: No relevant conflicts of interest to declare.

scholarly journals The Role of Structural Elements of the 5'-Terminal Region of p53 mRNA in Translation under Stress Conditions Assayed by the Antisense Oligonucleotide Approach

PLoS ONE ◽  
2015 ◽  
Vol 10 (10) ◽  
pp. e0141676 ◽  
Author(s):  
Agata Swiatkowska ◽  
Paulina Zydowicz ◽  
Agnieszka Gorska ◽  
Julia Suchacka ◽  
Mariola Dutkiewicz ◽  
...  
Keyword(s):  
Antisense Oligonucleotide ◽  
Terminal Region ◽  
Stress Conditions ◽  
Structural Elements ◽  
P53 Mrna

MiR-223 is dispensable for platelet production and function in mice

2013 ◽  
Vol 110 (12) ◽  
pp. 1207-1214 ◽  
Author(s):  
Xavier Loyer ◽  
Simon Leierseder ◽  
Tobias Petzold ◽  
Lin Zhang ◽  
Steffen Massberg ◽  
...  
Keyword(s):  
Platelet Adhesion ◽  
Cell Types ◽  
Surface Expression ◽  
Wild Type ◽  
Platelet Production ◽  
Multiple Cell ◽  
And Function ◽  
Deficient Mice ◽  
Platelet Depletion

SummaryMicroRNAs (miRNAs) are key physiological regulators in multiple cell types. Here, we assessed platelet production and function in mice deficient in miR-223, one of the most abundantly expressed miRNAs in platelets and megakaryocytes. We found platelet number, size, lifespan as well as surface expression of platelet adhesion receptors to be unchanged in miR-223-deficient mice. Likewise, loss of miR-223 did not affect platelet activation, adhesion and aggregation and also had no effect on bleeding times. Moreover, miR-223 null megakaryocytes developed normally and were capable to form pro-platelets. However, we detected a transient delay in the recovery of platelet numbers following antibody-induced platelet depletion in miR-223-deficient animals. This delay was not observed after transplantation of bone marrow from miR-223-deficient animals into wild-type recipients, indicating a non-cell-autonomous role of miR-223 for thrombopoiesis. Overall, our data indicate a surprisingly modest role of miR-223 in platelet production, while the function of platelets does not seem to depend on miR-223.

The Role of Recipient Platelets In the Prevention of Antibody-Mediated Transfusion Related Acute Lung Injury (TRALI)

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3351-3351
Author(s):  
Yuhan Chen ◽  
Michael Kim ◽  
Arata Tabuchi ◽  
Wolfgang M. Kuebler ◽  
Rukhsana Aslam ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Conflicts Of Interest ◽  
Scid Mice ◽  
Lung Damage ◽  
Cell Mediated Immunity ◽  
Shock Lung ◽  
Inflammatory Milieu ◽  
Platelet Depletion

Abstract Abstract 3351 Transfusion related acute lung injury (TRALI) is a serious complication of transfusion. The pathogenesis of TRALI is not fully understood but previous findings have suggested that platelet depletion can protect mice in a two-hit model of TRALI (Looney et al J Clin Invest 119:3450, 2009). To further understand the role of platelets in preventing antibody-mediated TRALI, two mouse models of immune thrombocytopenia (ITP) were utilized. In the passive ITP model, SCID mice were injected with a monoclonal anti-platelet antibody (MWReg30) intraperitoneally (ip, 18 h before TRALI induction) or intravenously (iv, 2 h before TRALI induction). In the active ITP model, SCID mice were transferred with splenocytes from anti-CD61 immune GPIIIa-knockout mice and thrombocytopenia occurred within 2 weeks post transfer (Chow et al Blood 115;1247, 2010). TRALI induction was performed by injecting the various thrombocytopenic SCID mice with a murine monoclonal MHC class I antibody (mAb, 34-1 -2s) iv and several parameters were observed for up to 2 h post antibody injection. In control, non-thrombocytopenic SCID mice, 34-1 -2s injection caused severe systemic shock as noted by reduced rectal temperatures which was associated with significant lung damage and mortality (45%) within 1 hour of 34-1 -2s infusion as previously shown (Fung et al. Blood DOI 10.1182/blood-2010-05-284570). In contrast, while SCID mice depleted of platelets by the passive ip route had systemic shock, lung damage and a 60% mortality rate, those mice made thrombocytopenic by the iv route were completely protected from mortality. On the other hand, in the active ITP model, where the induced thrombocytopenia is associated with a proinflammatory anti-platelet immune response, no mortality was observed in those mice made thrombocytopenic by antibody-mediated immune mechanisms whereas 80% of mice rendered thrombocytopenic by CD8+ T cell-mediated immunity were dead within 1 hr post 34-1 -2s infusion. These results suggest that thrombocytopenia in itself does not protect against antibody-mediated TRALI severity but the nature of the thrombocytopenia induction (e.g. acute passive iv infusion or active ITP immune transfer) is important. In fact, depending on the inflammatory milieu associated with the thrombocytopenia, platelets may actually increase the severity of TRALI. Disclosures: No relevant conflicts of interest to declare.

Platelet Sequestered Proteins Mediate Pre-Metastatic Communication Between Tumors and Bone

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1063-1063
Author(s):  
Bethany A. Kerr ◽  
Tatiana V. Byzova
Keyword(s):  
Bone Formation ◽  
Tumor Growth ◽  
Bone Remodeling ◽  
Primary Tumor ◽  
Conditional Knockout ◽  
Bone Microenvironment ◽  
Tumor Bearing ◽  
Tgf Β1 ◽  
Platelet Depletion

Abstract Tumors can be considered parasites that exploit the host’s resources in order to promote their own growth. Tumors secrete growth factors and cytokines (tumor secretome) which recruit platelets, blood vessels, and bone marrow-derived cells (BMDCs) to promote angiogenesis and tumor progression. We have recently demonstrated that distant tumor growth can stimulate bone formation and BMDC mobilization prior to metastasis. However, the mechanism of communication between the primary tumor and the bone microenvironment remains unknown. Signals from the tumor to the bone microenvironment are likely transmitted through the circulation; nevertheless, these signals need to be protected from degradation or utilization prior to reaching their target. We hypothesized that platelets could function as regulated storage compartments for the tumor secretome. Using a murine platelet depletion model during tumor growth, we assessed the role of platelets in BMDC homing and bone remodeling. We demonstrate that platelet depletion prevents BMDC mobilization and recruitment into tumors. Further, platelet depletion inhibited tumor-induced bone formation. To determine which tumor-derived proteins in platelets were responsible for changes in BMDC mobilization and bone remodeling, we analyzed the tumor secretome components and found that 77% of proteins are enriched within platelets over plasma, and that these proteins regulate BMDC mobilization and bone remodeling. In addition, we discovered that tumor-derived proteins, specifically transforming growth factor (TGF)-β1 and matrix metalloproteinases, sequestered within platelets could stimulate osteoblast differentiation and mineralization in vitro. We also found that thrombospondin (TSP)-1 levels are increased in the platelets of tumor-bearing mice. Finally, we assessed the role of the TSP-1/TGF-β1 signaling axis in tumor-induced bone formation and BMDC mobilization. Tumors in TSP-1 null mice were larger, however tumor-induced bone remodeling decreased. Interestingly, in tumor-bearing mice, high levels of TGF-β1 were being retained in the platelets due to a lack of TSP-1 to activate and release TGF-β1. To examine the role of platelet TGF-β1 in the process of tumor-induced bone remodeling, tumors were implanted in platelet-specific TGF-β1 conditional knockout mice and the changes in tumor size and the bone microenvironment were assessed. In summary, our data show that platelet sequestration and secretion of tumor-derived proteins represent a cellular mechanism mediating communication between the bone microenvironment and the primary tumor. Disclosures: No relevant conflicts of interest to declare.

Antisense inhibition of Na+/Ca2+ exchange during anoxia/reoxygenation in ventricular myocytes

2001 ◽  
Vol 281 (5) ◽  
pp. H2184-H2190 ◽  
Author(s):  
B. N. Eigel ◽  
R. W. Hadley
Keyword(s):  
Guinea Pig ◽  
Antisense Oligonucleotide ◽  
Ventricular Myocytes ◽  
Antisense Inhibition ◽  
Start Site ◽  
Intracellular Ca

This study investigated the role of the Na+/Ca2+ exchanger (NCX) in regulating cytosolic intracellular Ca2+concentration ([Ca2+]i) during anoxia/reoxygenation in guinea pig ventricular myocytes. The hypothesis that the NCX is the predominant mechanism mediating [Ca2+]i overload in this model was tested through inhibition of NCX expression by an antisense oligonucleotide. Immunocytochemistry revealed that this antisense oligonucleotide, directed at the area around the start site of the guinea pig NCX1, specifically reduced NCX expression in cultured adult myocytes by 90 ± 4%. Antisense treatment inhibited evoked NCX activity by 94 ± 3% and decreased the rise in [Ca2+]i during anoxia/reoxygenation by 95 ± 3%. These data suggest that NCX is the predominant mechanism mediating Ca2+ overload during anoxia/reoxygenation in guinea-pig ventricular myocytes.

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