Rivaroxaban attenuates thrombosis by targeting the NF-κB signaling pathway in a rat model of deep venous thrombus

Diagnostic and prognostic potential of long non-coding RNA NORAD in patients with acute deep vein thrombosis and its role in endothelial cell function

BACKGROUND

Deep venous thrombosis (DVT) is the common clinical cardiovascular disease, and easily develops into post-thrombotic syndrome (PTS). The study aimed to examine the clinical value of long non-coding RNA NORAD gene in the development of DVT and PTS. In vitro, the underlying mechanism was explored.

METHODS

Serum levels of lncRNA NORAD gene in 85 DVT cases and 85 healthy individuals were tested. The role of lncRNA NORAD gene in human umbilical vein endothelial cells (HUVECs) proliferation, migration and inflammation was examined. The candidate downstream target gene was predicted via bioinformatic analysis. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were done for the function annotation and pathway enrichment.

RESULTS

LncRNA NORAD gene was at high expression in the serum of DVT patients, it can distinguish DVT patients from healthy controls with the area under the curve of 0.919. Elevated expression of lncRNA NORAD gene in PTS patients was detected, DVT cases with high expression of lncRNA NORAD gene were more susceptible to PTS. LncRNA NORAD gene knockdown promoted HUVECs' proliferation, migration while suppressing cell apoptosis and inflammation. MiR-93-5p served as a target of lncRNA NORAD gene, and its overexpression reversed the role of lncRNA NORAD gene in the biological function of HUVECs. The target genes of miR-93-5p were enriched in HIF-1 signaling, TGF-beta signaling and PI3K-Akt signaling, protein-protein interaction (PPI) network indicated STAT3, MAPK1 to be the key targets.

CONCLUSIONS

Upregulation of expression of lncRNA NORAD gene was a potential diagnostic biomarker for DVT and related to the development of PTS. LncRNA NORAD/miR-93-5p axis was involved in the progress of DVT through regulating endothelial cell function.

CREB1 Silencing Protects Against Inflammatory Response in Rats with Deep Vein Thrombosis Through Reducing RPL9 Expression and Blocking NF-κB Signaling

Apoptosis and inflammation of vascular endothelial cells (VECs) are the most important causes of deep vein thrombosis (DVT). cAMP response element binding protein 1 (CREB1) encodes a transcription factor that binds as a homodimer to the cAMP-responsive element and can promote inflammation. CREB1 is found to be upregulated in the plasma of patients with venous thromboembolism. However, the biological functions of CREB1 in DVT remain unknown. We evaluated the effect of CREB1 in a rat model of inferior vena cava (IVA) stenosis-induced DVT. IVC stenosis resulted in stable thrombus, inflammatory response and CREB1 upregulation, whereas CREB1 knockdown inhibited thrombus and inflammation in DVT rats. In vitro analysis showed that CREB1 knockdown inhibited VEC apoptosis. Mechanistically, CREB1 knockdown reduced Ribosomal protein L9 (RPL9) expression and blocked the NF-κB pathway. Therefore, CREB1 may become a potential therapeutic target of DVT prevention.

Neutrophil extracellular traps mediate deep vein thrombosis: from mechanism to therapy

Deep venous thrombosis (DVT) is a part of venous thromboembolism (VTE) that clinically manifests as swelling and pain in the lower limbs. The most serious clinical complication of DVT is pulmonary embolism (PE), which has a high mortality rate. To date, its underlying mechanisms are not fully understood, and patients usually present with clinical symptoms only after the formation of the thrombus. Thus, it is essential to understand the underlying mechanisms of deep vein thrombosis for an early diagnosis and treatment of DVT. In recent years, many studies have concluded that Neutrophil Extracellular Traps (NETs) are closely associated with DVT. These are released by neutrophils and, in addition to trapping pathogens, can mediate the formation of deep vein thrombi, thereby blocking blood vessels and leading to the development of disease. Therefore, this paper describes the occurrence and development of NETs and discusses the mechanism of action of NETs on deep vein thrombosis. It aims to provide a direction for improved diagnosis and treatment of deep vein thrombosis in the near future.

Expression and role of interleukin-1β and associated biomarkers in deep vein thrombosis

Lower extremity deep vein thrombosis (DVT) is a common peripheral vascular disease, in which inflammation plays an important role. The aim of the present study was to investigate the expression and role of inflammatory factors in DVT. A rat model of venous thrombosis of the lower extremities was established through venous ligation surgery. The rats were examined at 2, 8, 24, 48 and 72 h after the induction of inferior venous stenosis and compared with control and sham surgery groups. The serum levels of interleukin-1β (IL-1β), tissue factor (TF) and xanthine oxidase (XOD) were measured using ELISAs. The morphology of the DVT tissue was observed by hematoxylin and eosin staining. Circulating endothelial cells (CECs) in peripheral blood were counted by flow cytometry. Reverse transcription-quantitative PCR and western blotting were used to detect mRNA and protein expression, respectively. The serum levels of IL-1β, TF and XOD exhibited no significant differences between the control and sham surgery groups. However, those in the rat model of DVT presented an upward trend from 2 to 24 h and peaked at 24 h, with a significant difference from the respective levels in the control and sham surgery groups. The histopathological analysis revealed the presence of red and mixed thrombi in the rats 2-48 h following the induction of inferior venous stenosis group with inflammatory cell infiltration in the vascular wall. Thrombus formation was evident after 72 h. While significant difference was observed in the number of CECs in the peripheral blood between the control and sham surgery groups, the number of peripheral blood CECs in the rats with inferior venous stenosis group increased from 8 to 72 h, with significant differences among these groups. The mRNA levels of IL-1β, TF, XOD and NF-κB in the tissues peaked at 24 h, with significant differences compared with those in the control and sham surgery groups. In addition, the protein expression level of NF-κB increased from 2 to 72 h. In conclusion, these results suggest that the high expression of IL-1β, TF, XOD and NF-κB may promote thrombus formation.

The associations between THBD c.1418C>T polymorphism and lower extremity deep vein thrombosis or endothelial progenitor cell

BACKGROUND

Studies have shown that the thrombomodulin gene (THBD) c.1418C>T polymorphism is associated with a variety of cardiovascular diseases. However, the study of THBD c.1418C>T polymorphism in deep vein thrombosis (DVT) is rare. This study aimed to reveal the correlation between the THBD c.1418C>T mutation and the occurrence of DVT, and to reveal partial molecular mechanism of endothelial progenitor cells (EPCs) participating in the onset of DVT.

METHODS

Whole blood samples of patients with lower extremity DVT (n = 100) and normal volunteers (n = 100) were collected to analyze the distribution of genotype of THBD c.1418C>T polymorphism using PCR and DNA sequencing. The pCMV6-entry vectors containing wild-type (WT) or mutated THBD cDNA (p. Ala473Val) were transfected into bone marrow derived EPCs. And the successful transfection of recombinant THBD and the stable expression of p. Ala473Val variant were determined by ELISA, respectively. Wound healing assay and Transwell migration assay were used to determine the migration ability of EPCs, and the cell angiogenesis ability was determined by tube formation assay. Western blotting was used to detect the expression level of related proteins.

RESULTS

The frequencies of CC, CT and TT genotypes were 56%, 36%, 8% in patients with lower extremity DVT and 72%, 25%, 3% in controls group, respectively, and THBD c.1418C>T polymorphism was related with increased risk of DVT, especially in women. High level of p. Ala473Val variant inhibited the EPCs migration, the p. Ala473Val variant significantly decreased the activation of protein C and the expressions of VEGFRs and MMP1, MMP2, MMP3. Furthermore, p. Ala473Val variant also weaken the angiogenesis of EPCs and decreased the expression level of VE-cadherin, Flk-1, eNOS, and TIE-2.

CONCLUSIONS

THBD c.1418C>T polymorphism is related with the lower extremity DVT, this may partially because of the inhibition of migration and angiogenesis of EPCs.

Transcriptomic Profiling of Femoral Veins in Deep Vein Thrombosis in a Porcine Model

Deep vein thrombosis (DVT) is a severe disease affecting the human venous system, accompanied by high morbidity and mortality rates caused by early and late complications. The study aimed at analyzing the changes in the transcriptome of the femoral vein caused by DVT in the porcine model based on the formation of the thrombus in vivo. The study was performed on 11 castrated male pigs: A thrombus was formed in each left femoral vein in six animals; the remaining five served as a control group. Total RNA was isolated from the left femoral veins of the experimental and control animals. High-throughput RNA sequencing was used to analyze the global changes in the transcriptome of veins with induced DVT. Applied multistep bioinformatics revealed 1474 differentially expressed genes (DEGs): 1019 upregulated and 455 downregulated. Functional Gene Ontology annotated 1220 of DEGs into 225 biological processes, 30 molecular functions and 40 cellular components categories. KEGG analysis disclosed TNF, NF-κB and apoptosis pathways’ overexpression in DVT samples. A thorough analysis of the detected DEGs indicated that a dysregulated inflammatory response and disturbed balance between clotting and anti-clotting factors play a crucial role in the process of DVT.

A New Experimental Porcine Model of Venous Thromboembolism

Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a severe disease affecting the human venous system, accompanied by high morbidity and mortality rates. The aim of the study was to establish a new porcine VTE model based on the formation of the thrombus in vivo. The study was performed on 10 castrated male pigs: thrombus was formed in each closed femoral vein and then successfully released from the right femoral vein into the circulation of animals. In six pigs PE was confirmed via both computed tomography pulmonary angiography and an autopsy. Our research presents a novel experimental porcine model of VTE that involves inducing DVT and PE in the same animal in vivo, making it suitable for advanced clinical research and testing of future therapies.

Cotinine inhibits TLR4/NF-κB signaling pathway and improves deep vein thrombosis in rats

Background: The present study was designed to explore the regulatory mechanisms and influences of cotinine on deep vein thrombosis (DVT) in rats via the toll-like receptor 4/nuclear factor κ binding (TLR-4/NF-κB) pathway. Methods: In this experimental study, 30 SD rats were randomly assigned to control group, sham operation group, model group, cotinine (10 μg/kg) group, and model + cotinine (10 μg/kg) group. The thromboxane B2 (TXB2), 6-keto-PGF_1α, plasminogen activator inhibitor (PAI), tissue plasminogen activator (t-PA), TLR4, NF-κB, and p65 mRNA and protein expression and tissue changes were analyzed by ELISA, Hematoxylin–Eosin (HE) staining, RT-PCR, and Western blot. Results: There was no significant difference between the control and sham operation groups (P>0.05). The model and cotinine groups showed significantly higher mRNA and protein levels of TXB2, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), PAI, TLR-4, and NF-κB, and significantly lower levels of 6-keto-PGF_1α and t-PA than the control and sham operation groups (P<0.05), and the model + cotinine group showed significantly higher mRNA and protein levels of TXB2, IL-6 and TNF-α, PAI, TLR-4, and NF-κB and significantly lower levels of 6-keto-PGF_1α and t-PA than the model group (P<0.05). Conclusion: Cotinine can aggravate thrombus and inflammation in rats with DVT, and the mechanism may be associated with the activation of the TLR-4/NF-κB inflammatory signaling pathway.

Prothrombotic effects of high uric acid in mice via activation of MEF2C-dependent NF-κB pathway by upregulating let-7c

Serum uric acid is reportedly associated with thrombosis development. However, still unclear is the mechanism of high uric acid in thrombosis with the involvement of let-7c. In an aim to fill this void, we conducted this study by treating mice and human umbilical vein endothelial cells with high uric acid. Analysis indicated that let-7c was upregulated in hyperuricemia patients as well as in mice and human umbilical vein endothelial cells treated with high uric acid. Furthermore, high uric acid inhibited myocyte enhancer factor-2C, but activated nuclear factor-kappa B pathway in human umbilical vein endothelial cells. Then the targeting relationship between let-7c and myocyte enhancer factor-2C was verified. On the one hand, high uric acid shortened activated partial thromboplastin time and prothrombin time of mice and declined tissue plasminogen activator level. Additionally, the treatment prolonged thrombin time and elevated the levels of thrombosis related molecules or proteins such as Fibrinogen and D-dimer. Nevertheless, these alternations could be reversed by inhibition of let-7c and nuclear factor-kappa B pathway or overexpressing myocyte enhancer factor-2C. To sum up, our results uncovered the pro-thrombotic effect of high uric acid in mice by activating myocyte enhancer factor-2C-dependent nuclear factor-kappa B pathway via let-7c upregulation.

Role of NF-κB in Platelet Function

Platelets are megakaryocyte-derived fragments lacking nuclei and prepped to maintain primary hemostasis by initiating blood clots on injured vascular endothelia. Pathologically, platelets undergo the same physiological processes of activation, secretion, and aggregation yet with such pronouncedness that they orchestrate and make headway the progression of atherothrombotic diseases not only through clot formation but also via forcing a pro-inflammatory state. Indeed, nuclear factor-κB (NF-κB) is largely implicated in atherosclerosis and its pathological complication in atherothrombotic diseases due to its transcriptional role in maintaining pro-survival and pro-inflammatory states in vascular and blood cells. On the other hand, we know little on the functions of platelet NF-κB, which seems to function in other non-genomic ways to modulate atherothrombosis. Therein, this review will resemble a rich portfolio for NF-κB in platelets, specifically showing its implications at the levels of platelet survival and function. We will also share the knowledge thus far on the effects of active ingredients on NF-κB in general, as an extrapolative method to highlight the potential therapeutic targeting of NF-κB in coronary diseases. Finally, we will unzip a new horizon on a possible extra-platelet role of platelet NF-κB, which will better expand our knowledge on the etiology and pathophysiology of atherothrombosis.

Protective effect of rivaroxaban on arteriosclerosis obliterans in rats through modulation of the toll-like receptor 4/NF-κB signaling pathway

The aim of the present study was to explore the pharmacological role of rivaroxaban in rats with arteriosclerosis obliterans (ASO) and the potential mechanism of its action. A total of 60 adult male Sprague Dawley (weighing 210–250 g) were randomly assigned into either the sham group, model group or Riv group. Rats in the sham group were fed a normal diet, whereas those in model group and Riv group were fed a high-fat diet for 8 weeks. After establishment of the ASO model, rats in the Riv group were intragastrically administered 10 mg/kg rivaroxaban, whereas those in the sham group and the model group were administrated with the same volume of 0.9% saline for 4 weeks. At the end of animal procedures, a blood sample and the femoral artery of the rats were harvested. The results of the present study revealed that rats in the model group presented with an irregularly narrowed femoral artery lumen, disordered endothelial cells, internal elastic plates and smooth muscle cells. By comparison, the arterial wall structure and stenosis of the femoral artery of rats in Riv group recovered and all the pathological changes were alleviated after rivaroxaban treatment. Levels of total cholesterol, triglycerides and low-density lipoproteins decreased, whereas the level of high-density lipoproteins increased in the Riv group compared with the model group. Rivaroxaban treatment significantly reduced serum levels of interleukin-1, tumor necrosis factor-α and monocyte chemoattractant protein-1 (MCP-1), and increased the serum level of transforming growth factor-β (TGF-β). Rats in the Riv group had reduced expression of toll-like receptor 4 (TLR4), NF-κB and MCP-1, and increased expression of TGF-β in femoral artery tissues compared with the model group. Therefore rivaroxaban may have exerted its anti-atherosclerotic effects by regulating the expression of genes in the TLR4/NF-κB signaling pathway and the activation of the downstream molecules.

New experimental animal model of intracardiac thrombus created with epicardial echocardiographic guidance

BACKGROUND

Models of intracardiac thrombus are very difficult to establish and have rarely been reported. We designed and established a new, inexpensive, practical animal model for intracardiac thrombus created with epicardial echocardiographic guidance.

METHODS

Male New Zealand white rabbits weighing 2 to 3.9 kg (3.10±0.58 kg) were used in this study. Cylindrical thrombi were created in plastic tubing and then aspirated with saline into a syringe. The thrombus in saline suspension was then slowly injected into a heart chamber and confirmed with echocardiography, including two-dimensional and contrast-enhanced ultrasound.

RESULTS

Intracardiac thrombi were created successfully in the left ventricle, right ventricle, and left and right atrial appendages. The average preparation time was about 3 hours. There were no significant differences among the four heart chambers in the success rate of thrombus model creation. Thrombi embolized to the pulmonary artery after failure of the right heart model. After failure of the left heart model, emboli were found in the carotid artery, renal artery, and truncus coeliacus. In two cases thrombi extended from the left ventricular apex into the aorta and in one case the thrombus extended from the left atrial appendage to the left atrium; there was no such extension from the other chambers. The rabbits' vital signs remained stable after establishment of the model, with no significant changes in heart structure or function.

CONCLUSIONS

This new method of creating an intracardiac thrombus model in rabbits showed initial success.