Antisense oligonucleotide for tissue factor inhibits hepatic ischemic reperfusion injury

Loss of RAR-α and RXR-α and enhanced caspase-3-dependent apoptosis in N-acetyl-p-aminophenol-induced liver injury in mice is tissue factor dependent

Tissue factor (TF) activates the coagulation system and has an important role in the pathogenesis of various diseases. Our previous study stated that retinoid receptors (RAR-α and RXR-α) are released as a lipid droplet in monocrotaline/ lipopolysaccharide-induced idiosyncratic liver toxicity in mice. Herein, the interdependence between the release of retinoid receptors RAR-α and RXR-α and TF in Nacetyl-p-aminophenol (APAP)-induced mice liver toxicity, is investigated. Serum alanine transaminase (ALT) level, platelet and white blood cells (WBCs) counts, protein expression of fibrin, TF, cyclin D1 and cleaved caspase-3 in liver tissues are analyzed. In addition, histopathological evaluation and survival study are also performed. The results indicate that using of TF-antisense (TF-AS) deoxyoligonucleotide (ODN) injection (6 mg/kg), to block TF protein synthesis, significantly restores the elevated level of ALT and WBCs and corrects thrombocytopenia in mice injected with APAP. TF-AS prevents the peri-central overexpression of liver TF, fibrin, cyclin D1 and cleaved caspase- 3. The release of RXR-α and RAR-α droplets, in APAP treated sections, is inhibited upon treatment with TF-AS. In conclusion, the above findings designate that the released RXR-α and RAR-α in APAP liver toxicity is TF dependent. Additionally, the enhancement of cyclin D1 to caspase-3-dependent apoptosis can be prevented by blocking of TF protein synthesis.

Antisense Tissue Factor Oligodeoxynucleotides Protected Diethyl Nitrosamine/Carbon Tetrachloride-Induced Liver Fibrosis Through Toll Like Receptor4-Tissue Factor-Protease Activated Receptor1 Pathway

Tissue factor (TF) is a blood coagulation factor that has several roles in many non-coagulant pathways involved in different pathological conditions such as angiogenesis, inflammation and fibrogenesis. Coagulation and inflammation are crosslinked with liver fibrosis where protease-activated receptor1 (PAR1) and toll-like receptor4 (TLR4) play a key role. Antisense oligodeoxynucleotides are strong modulators of gene expression. In the present study, antisense TF oligodeoxynucleotides (TFAS) was evaluated in treating liver fibrosis via suppression of TF gene expression. Liver fibrosis was induced in rats by a single administration of N-diethyl nitrosamine (DEN, 200 mg/kg; i. p.) followed by carbon tetrachloride (CCl4, 3 ml/kg; s. c.) once weekly for 6 weeks. Following fibrosis induction, liver TF expression was significantly upregulated along with liver enzymes activities and liver histopathological deterioration. Alpha smooth muscle actin (α-SMA) and transforming growth factor-1beta (TGF-1β) expression, tumor necrosis factor-alpha (TNF-α) and hydroxyproline content and collagen deposition were significantly elevated in the liver. Blocking of TF expression by TFAS injection (2.8 mg/kg; s. c.) once weekly for 6 weeks significantly restored liver enzymes activities and improved histopathological features along with decreasing the elevated α-SMA, TGF-1β, TNF-α, hydroxyproline and collagen. Moreover, TFAS decreased the expression of both PAR1 and TLR4 that were induced by liver fibrosis. In conclusion, we reported that blockage of TF expression by TFAS improved inflammatory and fibrotic changes associated with CCl4+DEN intoxication. In addition, we explored the potential crosslink between the TF, PAR1 and TLR4 in liver fibrogenesis. These findings offer a platform on which recovery from liver fibrosis could be mediated through targeting TF expression.

Carbon tetrachloride-induced liver injury in mice is tissue factor dependent

Tissue factor (TF) is a membranous glycoprotein that activates the coagulation system when blood vessels or tissues are damaged. TF was up-regulated in monocrotaline (MCT)/lipopolysaccharide (LPS) hepatotoxicity model. The present study aimed to test the hypothesis that TF-dependent fibrin deposition occurs in liver toxicity induced by CCl4 in mice. Pericentral deposition of TF and fibrin is induced after CCl4-induced liver toxicity. The toxicity was evaluated by determination of serum activities of ALT, AST and ALP as well as GSH content and histopathological changes. The results showed that injection of mice with TF-antisense deoxyoligonucleotide (TF-AS) prevented the accumulation of TF and fibrin in the hepatic tissues. Furthermore, it significantly restored blood biochemical parameters, GSH content and distorted histopathological features caused by CCl4. The current study demonstrates that TF activation is associated with CCl4-induced liver injury. Furthermore, administration of TF-AS successfully prevented this type of liver injury.

Tissue factor antisense deoxyoligonucleotide prevents monocrotaline/LPS hepatotoxicity in mice

Tissue factor (TF) is a membranous glycoprotein that functions as a receptor for coagulation factor VII/VIIa and activates the coagulation system when blood vessels or tissues are damaged. TF was upregulated in our monocrotaline (MCT)/lipopolysaccharide (LPS) hepatotoxicity model. We tested the hypothesis that TF-dependent fibrin deposition and lipid peroxidation in the form of oxidized low-density-lipoprotein (ox-LDL) accumulation contribute to liver inflammation induced by MCT/LPS in mice. In the present study, we blocked TF using antisense oligodeoxynucleotides against mouse TF (TF-ASO). TF-ASO (5.6 mg kg(-1) ) was given i.v. to ND4 male mice 30 min after administration of MCT (200 mg kg(-1) ) p.o. followed after 3.5 h by LPS i.p. (6 mg kg(-1) ). Blood alanine aminotransferase (ALT), TF, ox-LDL, platelets, hematocrit and keratinocyte-derived chemokine (KC) levels were evaluated in different treatment groups. Fibrin deposition and ox-LDL accumulation were also analyzed in the liver sections using immunofluorescent staining. The results showed that TF-ASO significantly restored blood ALT, hematocrit and KC levels, distorted after MCT/LPS co-treatment, as well as preventing the accumulation of ox-LDL and the deposition of fibrin in the liver tissues, and thereby inhibited liver injury caused by MCT/LPS. In a separate experiment, TF-ASO administration significantly prolonged animal survival. The current study demonstrates that TF is associated with MCT/LPS-induced liver injury. Administration of TF-ASO successfully prevented this type of liver injury.

Silencing of tissue factor by antisense deoxyoligonucleotide prevents monocrotaline/LPS renal injury in mice

Tissue factor (TF) is involved in monocrotaline (MCT)/lipopolysaccharide (LPS) hepatotoxicity. It is not known whether MCT/LPS can cause renal toxicity and whether TF is involved in this toxicity. Thus, the present study was undertaken to investigate the potential renal toxicity after MCT/LPS co-treatment and the involvement of TF in this toxicity. MCT was delivered to ND4 male mice (200 mg/kg) per os followed 4 h later by treatment with LPS ip (6 mg/kg) to investigate its effect on kidney. We injected TF antisense oligonucleotide (TF-AS) intravenously (i.v) in mice prior to LPS treatment, to block TF, and measured their blood urea nitrogen (BUN), creatinine (CRE), alkaline phosphatase (ALP), and potassium. In MCT/LPS co-treated group, fibrin was detected on the glomerular capillary lumina, distal tubules of renal cortex, and the necrotic tubules of renal medulla. An elevation of BUN, creatinine, and the BUN/creatinine ratio was seen in mice with MCT/LPS co-treatment, compared to animals receiving LPS or MCT alone. Simultaneously, an aggressive tubular necrosis was seen in the medullary tubules in the same group which may account for the oliguria observed in these animals. Fourfold inductions in the plasma TF level was detected at 10 h after MCT/LPS co-treatment which increased to 18-fold at 24 h. Increased blood level of leptin, interleukin-6 (IL-6) and downregulation of tubular chemokine (C-X-C motif) ligand 16 (CXCL16) are characteristic features in MCT/LPS co-treated animal. On the other hand, mice injected with TF-AS in the presence of MCT/LPS co-treatment showed no elevation of the blood BUN, creatinine, potassium, and normal levels of the proinflammatory molecules. TF-AS injection significantly prevented glomerular and tubular fibrin deposition, tubular necrosis, and improvement of the animal survivability. Renal toxicity involving TF can be prevented successfully by the use of TF-AS.

Role of the coagulation system in acetaminophen-induced hepatotoxicity in mice

Acetaminophen (N-acetyl-p-aminophenol [APAP]) is one of the leading causes of acute liver failure, and APAP hepatotoxicity is associated with coagulopathy in humans. We tested the hypothesis that activation of the coagulation system and downstream protease-activated receptor (PAR)-1 signaling contribute to APAP-induced liver injury. Fasted C57BL/J6 mice were treated with either saline or APAP (400 mg/kg intraperitoneally) and were euthanized 0.5-24 hours later. Hepatotoxicity and coagulation system activation occurred by 2 hours after administration of APAP. Treatment with APAP also caused a rapid and transient increase in liver procoagulant activity. In addition, significant deposition of fibrin was observed in the liver by 2 hours, and the concentration of plasminogen activator inhibitor-1 in plasma increased between 2 and 6 hours. Pretreatment with heparin attenuated the APAP-induced activation of the coagulation system and hepatocellular injury and diminished hepatic fibrin deposition at 6 hours. Loss of hepatocellular glutathione was similar in APAP-treated mice pretreated with saline or heparin, suggesting that heparin did not diminish bioactivation of APAP. In mice deficient in tissue factor, the principal cellular activator of coagulation, APAP-induced liver injury, activation of coagulation, and hepatic fibrin deposition were reduced at 6 hours. Formation of the tissue factor-factor VIIa complex leads to the generation of thrombin that can activate cells through cleavage of PAR-1. Mice lacking PAR-1 developed less injury and hepatic fibrin deposits at 6 hours in response to APAP than control mice.

CONCLUSION

Activation of the coagulation system and PAR-1 signaling contribute significantly to APAP-induced liver injury.

Tissue factor upregulation drives a thrombosis-inflammation circuit in relation to cardiovascular complications

The extrinsic coagulation is recognized as an 'inducible' signalling cascade resulting from tissue factor (TF) upregulation by exposure to clotting zymogen FVII upon inflammation or tissue injury. Following the substantial initiation, an array of proteolytic activation generates mediating signals (active serine proteases: FVIIa, FXa and FIIa) that lead to hypercoagulation with fibrin overproduction manifesting thrombosis. In addition, TF upregulation plays a central role in driving a thrombosis-inflammation circuit. Coagulant mediators (FVIIa, FXa and FIIa) and endproduct (fibrin) are proinflammatory, eliciting tissue necrosis factor, interleukins, adhesion molecules and many other intracellular signals in different cell types. Such resulting inflammation could ensure 'fibrin' thrombosis via feedback upregulation of TF. Alternatively, the resulting inflammation triggers platelet/leukocyte/polymononuclear cell activation thus contributing to 'cellular' thrombosis. TF is very vulnerable to upregulation resulting in hypercoagulability and subsequent thrombosis and inflammation, either of which presents cardiovascular risks. The prevention and intervention of TF hypercoagulability are of importance in cardioprotection. Blockade of inflammation reception and its intracellular signalling prevents TF expression from upregulation. Natural (activated protein C, tissue factor pathway inhibitor, or antithrombin III) or pharmacological anticoagulants readily offset the extrinsic hypercoagulation mainly through FVIIa, FXa or FIIa inhibition. Therefore, anticoagulants turn off the thrombosis-inflammation circuit, offering not only antithrombotic but anti-inflammatory significance in the prevention of cardiovascular complications.

Prospects of antisense oligodeoxynucleotides to alleviate renal ischaemia-reperfusion injury

Renal ischaemia-reperfusion (I/R) injury is a clinically significant problem and an invariable consequence of renal transplantation. The problem begins at the onset of acute tubular necrosis (ATN), when the transplantation takes a long ischaemic interval by using the cardiac arrest donor's kidney. In addition, the longer the ischaemic interval, the higher the incidence rate of ATN. It is clinically important that renal I/R injury is reduced. The antisense oligodeoxynucleotide (AS-ODN), developed as a therapy for intractable diseases at the gene level, has recently been established as an important method in examining specific gene functions. The authors have previously demonstrated that AS-ODN/tissue factor (TF) prevents renal I/R injury. This review discusses the efficacy of AS-ODN/TF and AS-ODN/intercellular adhesion molecule-1 as existing targets, and the potential of AS-ODN/nuclear factor-kappaB, AS-ODN/cyclooxygenase and AS-ODN/5-lipoxygenase as prospective targets.

Tissue factor and tumor: clinical and laboratory aspects

This review summarizes data demonstrating the role of TF in tumor development, metastasis and angiogenesis. TF is a transmembrane protein that is expressed constitutively in some kinds of extravascular cells and transiently in intravascular cells after stimulation with cytokines and growth factors. Originally TF was considered to have a function in the initiation of coagulation. In the last years it became evident that TF plays a role in physiological and pathological processes outside the hemostasis. Up-regulation of TF expression appears to be characteristic of tumor tissue. In a variety of human tumors it was shown by immunohistochemistry, that TF can be expressed in malignant cells as well as in tumor-infiltrating macrophages or endothelial cells. Such abnormal TF expression contributes to the angiogenic process by a shift in the balance between endogenous proangiogenic and antiangiogenic factors. Observations of a significant correlation between elevated TF expression with increased microvessel density and VEGF expression underline the TF involvement in tumor angiogenesis. Furthermore, TF expression influences also metastasis. The effect of TF on metastasis may result from its angiogenic effect, but also from the production of growth factors or adhesion proteins.

Tissue factor: (patho)physiology and cellular biology

The transmembrane glycoprotein tissue factor (TF) is the initiator of the coagulation cascade in vivo. When TF is exposed to blood, it forms a high-affinity complex with the coagulation factors factor VII/activated factor VIIa (FVII/VIIa), activating factor IX and factor X, and ultimately leading to the formation of an insoluble fibrin clot. TF plays an essential role in hemostasis by restraining hemorrhage after vessel wall injury. An overview of biological and physiological aspects of TF, covering aspects consequential for thrombosis and hemostasis such as TF cell biology and biochemistry, blood-borne (circulating) TF, TF associated with microparticles, TF encryption-decryption, and regulation of TF activity and expression is presented. However, the emerging role of TF in the pathogenesis of diseases such as sepsis, atherosclerosis, certain cancers and diseases characterized by pathological fibrin deposition such as disseminated intravascular coagulation and thrombosis, has directed attention to the development of novel inhibitors of tissue factor for use as antithrombotic drugs. The main advantage of inhibitors of the TF*FVIIa pathway is that such inhibitors have the potential of inhibiting the coagulation cascade at its earliest stage. Thus, such therapeutics exert minimal disturbance of systemic hemostasis since they act locally at the site of vascular injury.

Tissue factor antisense oligonucleotides prevent renal ischemia-reperfusion injury

BACKGROUND

Tissue factor (TF) expression is induced on macrophages and endothelial cells during the immune response. We designed an antisense (AS) phosphorothioate oligodeoxynucleotide (ODN) to specifically inhibit the expression of rat TF to study the effects of the AS ODN on renal ischemia-reperfusion injury in the rat.

METHOD

AS-1 ODN for TF was delivered intravenously to inhibit the expression of TF in endothelial cells. After 8 hr, the right kidney was harvested and the left renal artery and vein were clamped. The kidney was reperfused after 90 min of ischemia, and rats were killed at 0, 1.5, 5, 12, and 24 hr after reperfusion. TF expression was analyzed by immunohistochemical staining using monoclonal antibody.

RESULTS

In the untreated ischemic group, 0 of 20 rats survived beyond day 3. However, treatment with AS-1/TF led to 12 of 20 rats surviving beyond day 4. TF was detected on distal tubular epithelial cells, endothelial cells, and blood vessels but not on necrotic and proximal tubular epithelial cells. The necrotic area extended and encompassed nearly all of the ischemic kidney within 12 hr after reperfusion. The necrotic area and the grade of TF staining were more significantly reduced in the AS-1/TF-treated group than in the control group. Furthermore, fluorescein isothiocyanate-labeled AS-1/TF was significantly intense in tubular epithelial cells 8 hr after intravenous administration.

CONCLUSIONS

The results indicate that AS-1/TF inhibited the ischemia-reperfusion injury of the kidney. Microcirculatory incompetence resulting from microthrombus may cause the formation and development of necrosis.