Rat Model Of Venous Thrombosis Research Articles

ET1 acts as a potential plasma biomarker and therapeutic target in deep venous thrombosis rat model.

Deep venous thrombosis (DVT) is the third leading cause of death in cardiovascular disease, following heart attacks and strokes. Early diagnosis and intervention are crucial for effective DVT therapy. We aim to investigate whether endothelin-1 (ET-1) could serve as an early diagnostic marker or a potential therapeutic target in a DVT rat model. CCK8 assay, invasion assay, and flow cytometry were used to detect the proliferation, migration and apoptosis of HUVECs, respectively. Elisa assay was used to detect ET-1 and coagulation factor VII in cell supernatant and rat?s plasma. Western blot was used to detect antioxidant signaling protein. Inferior vena cava stenosis was used to construct the DVT rat model. Lentivirus mediated overexpression of ET-1 in HUVECs impaired the cell proliferation and migration, increased cell apoptosis, inhibited the antioxidant signaling pathway proteins expression (e.g., NQO1, GCLC, Nrf-2), and upregulated coagulation factor VII. Furthermore, overexpression of ET-1 further impaired antioxidant signaling pathway protein in response to H2O2 treatment. However, lentivirus mediated ET-1 knockdown and BQ123 (an ET-1 inhibitor), showed the opposite results with ET-1 overexpression. We then established a DVT rat model by inferior vena cava stenosis. The stenosis induced early expression of ET-1 and coagulation factor VII in plasma at day 1 and restore their level at day 10. BQ123 could downregulate the coagulation factor VII to ameliorate the stenosis effects. Our findings suggest that ET-1 might serve as an early diagnostic marker for DVT rat model and a potential therapeutic target for treating DVT.

Increased Antithrombotic Properties of Unfractionated Heparin in Rats Following Oral Administration of Multiple Doses and Its Correlation with Endothelial Heparin Concentration

In a rat model of venous thrombosis, a single oral dose of 7.5mg kg-1 of Unfractionated Heparin (UFH) lowers thrombosis by 50%. Since clinical long-term use is necessary, our goals were to investigate the antithrombotic effects of repeated oral UFH administration. Rats were given three doses of 7.5mg kg-1 every 12, 24, 48, and 72 hours apart—as well as three or fifteen doses of 1 mg kg—1 every 48 hours—by oral gavage of cow lung UFH. The final dosage was injecting 10% formalin in methanol into the jugular vein right after thrombus start. Four hours later, the vessel was checked for thrombosis. Heparin levels in endothelium and tissue as well as plasma anticoagulant activity were assessed. As 3×7.5 When heparin (mg kg-1) was administered, the incidence of thrombosis was notably lower during 48-hour dosing intervals than with a single dose. Endothelial heparin concentration and thrombotic incidence were negatively correlated, while anticoagulant activity was not. Treatment with three doses of 1mg kg-1 every 48 hours resulted in a thrombotic incidence comparable to that of a single dosage. The total thrombotic incidence after 15 doses was comparable to that following s.c. treatment and was lower than that of 3 doses. Oral UFH delivery resulted in increased antithrombotic activity and antithrombotic effects that were comparable to those of s.c. administration. Heparin’s antithrombotic effect on endothelium was linked to it.

Bone marrow-derived mesenchymal stem cells accelerate angiogenesis in pregnant experimentally induced deep venous thrombosis rat model via up-regulation of pro-angiogenic secretogranin II.

The present study investigated whether bone marrow-derived mesenchymal stem cells (BMMSCs) facilitate angiogenesis and improve outcomes of pregnancy with obstetric deep venous thrombosis (DVT) and explored the underlying mechanism. A pregnant DVT rat model was established using a "stenosis" method on the lower segment of the inferior vena cava (IVC). The extent of vascularization in thrombosed IVC was examined by immunohistochemistry. In addition, the effect of BMMSCs on DVT pregnancy outcomes was evaluated. We also characterized the effect of BMMSC-derived conditioned medium (BM-CM) on the impaired human umbilical vein endothelial cells (HUVECs). Thereafter, transcriptome sequencing was employed to identify the differentially expressed genes in thrombosed IVC tissues of DVT and DVT plus BMMSCs (thrice) groups. Lastly, the candidate gene's role in the promotion of angiogenesis was demonstrated in vitro and in vivo. The DVT model was successfully established using IVC stenosis. The injection of three consecutive BMMSC doses into pregnant SD rats with DVT was demonstrated to be the most effective treatment, which significantly reduced the length and weight of the thrombus, induced the highest level of angiogenesis, and ameliorated the embryo absorption rate. In vitro, BM-CM efficiently increased the abilities of impaired endothelial cells to proliferate, migrate, invade, and form vessel-like tubes, while inhibiting their apoptosis. Transcriptome sequencing revealed that BMMSCs induced a prominent upregulation of a variety of pro-angiogenic genes, including secretogranin II (SCG2). When SCG2 expression was knocked down by lentivirus, the BMMSCs' and BM-CM-induced pro-angiogenic effects on pregnant DVT rats and HUVECs were markedly attenuated. In conclusion, the study results suggest that BMMSCs enhance angiogenesis via up-regulation of SCG2, providing an effective alternative regenerative agent and novel target for the therapy of obstetric DVT.

Impact of repeated intravenous infusions of umbilical cord-derived versus bone marrow-derived mesenchymal stem cells on angiogenesis in a pregnant experimentally induced deep venous thrombosis rat model.

Deep venous thrombosis (DVT) therapy during pregnancy warrants special consideration for the woman and the fetus. This study aimed to evaluate the impact of umbilical cord-derived mesenchymal stem cells (UC-MSCs) and bone marrow-derived mesenchymal stem cells (BM-MSCs) in terms of pro-angiogenic capacity and amelioration of pregnancy outcomes. The pregnant DVT rat model was successfully established by the "stenosis" method. Three consecutive injections of both UC-MSCs and BM-MSCs improved angiogenesis and ameliorated the embryo absorption rate in pregnant SD rats with DVT, in which UC-MSCs promoted angiogenesis more significantly. Furthermore, the levels of serum vascular endothelial growth factor-A (VEGF-A) and epidermal growth factor (EGF) were significantly higher in the UC-MSC group compared to those of the BM-MSC group. Thereafter, differentially expressed genes (DEGs) in thrombosed inferior vena cava tissues in the UC-MSC and BM-MSC groups were identified using transcriptome sequencing and further assessed by RT-qPCR and western blotting. The bioinformatics analysis indicated that the enriched DEG terms occurred in the cytokine activity, and the DEG pathways were significantly enriched in the cytokine-cytokine receptor interaction. In addition, both the mRNA and protein levels of angiogenic genes and their receptors, including VEGF-A, VEGF receptor-1, EGF, and EGF receptor, were significantly higher in the UC-MSC group. In conclusion, the BM-MSCs and UC-MSCs both significantly stimulate angiogenesis and ameliorate the embryo absorption rate in pregnant SD rats with DVT, but the difference in cytokine secretion causes UC-MSCs to have more potent angiogenic effects than BM-MSCs.

Novel pH-responsive and mucoadhesive chitosan-based nanoparticles for oral delivery of low molecular weight heparin with enhanced bioavailability and anticoagulant effect

Low molecular weight heparin (LMWH) shows great anticoagulant effect for prevention and treatment of deep venous thrombosis. However, its oral administration is seriously hindered by multiple obstacles. In this study, a pH-responsive delivery system was developed to protect LMWH from gastrointestinal tract degradation and facilitate its absorption across gastrointestinal mucosa. The LMWH-loaded nanoparticles (pH-TCS/O-CMCS@LMWH) were prepared by ionic-crosslinking reaction between positive-charged amino groups of thiolated chitosan (TCS) as well as o-carboxymethyl chitosan (O-CMCS) and oppositely charged HP55. As a result, the prepared nanoparticles proved to spherical shape with an average size of 332 nm, high encapsulation efficiency of 96.6% and drug-loading content of 12.04 IU/mg. The proposed pH-TCS/O-CMCS@LMWH also showed good colloidal stability, potential mucoadhesive effect and desirable pH-responsive drug release behavior, which decreased pre-mature LMWH release in acidic environment but increase its targeted release in intestine environment. After oral administration, the pH-TCS/O-CMCS@LMWH shown enhanced bioavailability and significant antithrombotic effect in a rat model of venous thrombosis. In conclusion, pH-TCS/O-CMCS nanoparticles can be successfully hold great promising for oral administration of LMWH and potential treatment for thrombosis.

A novel severe cerebral venous thrombosis rat model based on semi-ligation combined with ferric chloride and thrombin.

An applicable cerebral venous sinus thrombosis (CVST) model is imperative for exploring its pathophysiology. We established a novel severe CVST model using semi-ligation, ferric chloride, and thrombin. A total of 138 male Sprague-Dawley rats were randomly divided into semi-ligation (n=75) and non-semi-ligation (n=63) groups. A sham group (n=46) was also included. We compared short-term and long-term neurological and cognitive dysfunction, mortality rates, thrombus load, venous infarction volume, the blood-brain barrier permeability, brain water content, and microglia activation among the three groups. Thrombi involving multiple venous sinuses appeared in all semi-ligation rats within 2 days postoperatively. Compared with the non-semi-ligation group, short-term and long-term neurological dysfunction were more severe (p< 0.05), and thrombus weight, venous infarction volumes, and microglia activation were more significant (p< 0.05) in the semi-ligation group. Further, the cognitive function of the semi-ligation group significantly decreased (p< 0.05) on postoperative day 21. Cumulative mortality rates between the semi-ligation and non-semi-ligation groups did not differ significantly. Semi-ligation combined with ferric chloride and thrombin can produce a severe CVST model with multiple venous sinus involvement, which is suitable for short- and long-term neurological and cognitive dysfunction assessment.

MARTX toxin of Vibrio vulnificus induces RBC phosphatidylserine exposure that can contribute to thrombosis

V. vulnificus-infected patients suffer from hemolytic anemia and circulatory lesions, often accompanied by venous thrombosis. However, the pathophysiological mechanism of venous thrombosis associated with V. vulnificus infection remains largely unknown. Herein, V. vulnificus infection at the sub-hemolytic level induced shape change of human red blood cells (RBCs) accompanied by phosphatidylserine exposure, and microvesicle generation, leading to the procoagulant activation of RBCs and ultimately, acquisition of prothrombotic activity. Of note, V. vulnificus exposed to RBCs substantially upregulated the rtxA gene encoding multifunctional autoprocessing repeats-in-toxin (MARTX) toxin. Mutant studies showed that V. vulnificus-induced RBC procoagulant activity was due to the pore forming region of the MARTX toxin causing intracellular Ca2+ influx in RBCs. In a rat venous thrombosis model triggered by tissue factor and stasis, the V. vulnificus wild type increased thrombosis while the ΔrtxA mutant failed to increase thrombosis, confirming that V. vulnificus induces thrombosis through the procoagulant activation of RBCs via the mediation of the MARTX toxin.

Thrombolytic Effect of Nattokinase and Its Mechanism

Objective: Exploring the anti-thrombotic effect and mechanism of nattokinase in vitro and vivo. Methods: The thrombolytic effect of NK on old thrombus was studied by blood clot lysis method in vitro, the rat carotid artery thrombosis model induced by ferric chloride and the rat venous thrombosis model induced by inferior vena cava ligation method were used to study the thrombolytic effect of NK in vivo. TXB2, 6-k, PGE2, t-PA, \begin{document}$\cdot {\rm{O}}_2^- $\end{document} , ·OH, XOD and other indicators were detected to explore the antithrombotic mechanism of NK. Results: Nattokinase could significantly dissolve old thrombus (P \begin{document}$\cdot {\rm{O}}_2^- $\end{document} , ·OH and XOD. The values of TXB2, PEG2, \begin{document}$\cdot {\rm{O}}_2^- $\end{document} , ·OH and XOD were increased significantly, while the values of 6-K-PGF1 α and t-PA were decreased significantly. Conclusion : NK had strong thrombolytic activity in vivo and vitro, and had effect on fresh thrombus and old thrombus. NK could inhibit thrombosis by inhibiting platelet aggregation, reduce oxidative damage and reducing the level of coagulation factors. NK could also play a direct thrombolytic role by stimulating the production of t-PA, dissolving fibrin, and might play an indirect thrombolytic role by inhibiting the production of PAI-1.

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.

MiR-150 regulates endothelial progenitor cell differentiation via Akt and promotes thrombus resolution

BackgroundDeep venous thrombosis (DVT) constitutes a major global disease burden. Endothelial progenitor cells (EPCs) have been described in association with recanalization of venous thrombus. Furthermore, emerging evidence suggests microRNAs are involved in this progression. The goal of this study was to investigate the influence of miR-150 on the behavior of EPCs and its potential contribution in venous thrombosis resolution.MethodsWe isolated and cultured EPCs from healthy adults. Next, early EPCs or endothelial colony-forming cells (ECFCs or late EPCs) were transfected with miR-150 agomir and antagomir. Gene expression profiles, proliferation, cytokine secretion, and angiogenic capacity of early EPCs and ECFCs were examined. The effects of miR-150 on c-Myb expression and Akt/FOXO1 signaling were also evaluated. Furthermore, a rat model of venous thrombosis was constructed to determine the in vivo function of EPCs.ResultsOur results showed that miR-150 overexpression in early EPCs significantly promoted differentiation to ECFCs and contributed to proliferation and tube formation. However, suppression of miR-150 in late EPCs inhibited proliferation and tube formation. Moreover, we identified that this progression is regulated by inhibition of c-Myb and activation of the Akt/FOXO1 pathway. Our findings also showed that miR-150 led to the enhanced resolution ability of EPCs in a rat venous thrombosis model.ConclusionsIn this study, we present a novel mechanism of miRNA-mediated regulation of EPCs and Akt activation in thrombus resolution.

Resveratrol Induces Endothelial Progenitor Cells Angiogenesis via MiR-542-3p by Targeting Angiopoietin-2 and Involves in Recanalization of Venous Thrombosis.

BackgroundEndothelial progenitor cells (EPCs) play an important role in therapeutic angiogenesis. Besides, resveratrol (RSV) exerts many pharmacological functions in regulation of cell function. Furthermore, microRNAs (miRNAs) have been considered to be of great significance in biological process. In this study, we aimed to investigate the effect of RSV on EPCs and its potential mechanism that involved in recanalization of venous thrombosis.Material/MethodsEPCs were treated with RSV, and angiogenic functions was evaluated by tube formation and migration assays. miR-542-3p expression level in EPCs was assessed and exogenously modified. Bioinformatic analysis was applied to detect the potential target of miR-542-3p. Effects of RSV treatment in vivo venous thrombosis rat model were evaluated.ResultsRSV enhanced angiogenic function of EPCs and decreased expression of miR-542-3p. Dual luciferase reporter gene and western blot results confirmed angiopoietin-2 (ANGPT2) was a direct target of miR-542-3p. It was found that inhibition of miR-542-3p contributed to angiogenesis of EPCs and elevated ANGPT2 protein level. Finally, in a rat model of venous thrombosis, RSV-treated EPCs promoted recanalization of thrombi.ConclusionsWe demonstrated that RSV can contribute to progenitor cells angiogenesis via miR-542-3p by targeting ANGPT2, subsequently enhanced recanalization of thrombi.

MiR-21 induces endothelial progenitor cells proliferation and angiogenesis via targeting FASLG and is a potential prognostic marker in deep venous thrombosis

BackgroundDeep venous thrombosis (DVT) of lower extremities is a common thrombotic disease, occurring either in isolation or as a complication of other diseases or procedures. MiR-21 is one of important microRNAs which play critical role in various cellular function. This study aim to determine the effect of miR-21 on endothelial progenitor cells (EPCs) and its role in predicting prognosis of DVT.MethodsEPCs was isolated from DVT models and control subjects. miR-21 expression was confirmed by RT-PCR. Potential target mRNA was predicted by bioinformatics analysis. EPCs biological functions were examined by CCK-8 and tube formation assay. Besides, miR-21 expression was determined in DVT patients to investigate the correlation between miR-21 expression and prognosis of DVT. Cox proportional hazard regression analyses were also performed to reveal the risk factors associated with prognosis.ResultsHere, we found miR-21 was downregulated in EPCs of DVT model rats. Increased miR-21 expression promoted proliferation and angiogenesis of EPCs. Moreover, we demonstrated that FASLG was a target of miR-21 and revealed that FASLG knockdown inhibited function of EPCs. Upregulation of miR-21 led to thrombus resolution in a rat model of venous thrombosis. In addition, lower expression level of miR-21 in DVT patients was associated with an increase of recurrent DVT and post thrombotic syndrome (PTS). Furthermore, Cox proportional hazard regression analyses demonstrated miR-21 expression level as an independent predictor of recurrence of DVT.ConclusionsOur data revealed a role of miR-21 in regulating biological function of EPCs and could be a predictor for recurrent DVT or PTS.

A Direct Oral Anticoagulant Edoxaban Enhanced Fibrinolysis Via Inhibition of Thrombin-Activatable Fibrinolysis Inhibitor Activation and Enhancement of Plasmin Generation in Human Plasma

Introduction: Direct oral anticoagulants are as effective as vitamin K antagonists for the treatment of venous thromboembolism and are associated with less bleeding. We have reported that a direct oral factor Xa inhibitor edoxaban exerts a thrombus resolution effect in a rat model of venous thrombosis and enhances tissue plasminogen activator (t-PA)-induced clot lysis in human plasma. However, the mechanism underlying the thrombus resolution effect and fibrinolysis enhancement by edoxaban remains to be determined.Purposes: To evaluate the effect of edoxaban on plasmin generation during clot lysis in human plasma in vitro. To determine the role of thrombin-activatable fibrinolysis inhibitor (TAFI) in the enhancement of fibrinolysis by edoxaban.Methods: Pooled human normal plasma or TAFI-deficient plasma (both containing 180 ng/mL t-PA and 0.1 nM thrombomodulin) was mixed with edoxaban, an activated TAFI (TAFIa) inhibitor (a fibrinolysis enhancer) potato tuber carboxypeptidase inhibitor (PCI), or vehicle. Clot was induced by adding 2.5 pM tissue factor and 4 µM phospholipids. To monitor the clot formation and lysis, the absorbance of plasma at 405 nm was measured every 30 sec. Clot lysis time was defined as the interval between the time of the midpoint of the clear to maximum turbidity transition and the midpoint of the maximum turbidity to clear transition. Plasmin-α2 antiplasmin complex (PAP) concentration was measured by ELISA as an indicator of plasmin generation.Results: In normal plasma, PCI accelerated clot lysis and increased plasma PAP concentration. There was a correlation between plasma PAP concentration and percent of clot lysis, indicating that plasma PAP concentration is an appropriate marker of fibrinolysis. Edoxaban at clinically relevant concentrations (75, 150, and 300 ng/mL) significantly shortened clot lysis time and elevated plasma PAP concentration. The additive combined effect of edoxaban and PCI was observed. In TAFI-deficient plasma, clot lysis time was shortened and plasma PAP concentration increased compared with normal plasma. In these samples, the effects of edoxaban and PCI on clot lysis and plasma PAP concentration were markedly diminished as compared with normal plasma.Conclusions: Edoxaban at clinically relevant concentrations enhanced t-PA-induced clot lysis with increasing plasma PAP concentration in human plasma. The effects of edoxaban on clot lysis and plasmin generation were diminished in TAFI-deficient plasma. A TAFIa inhibitor PCI exerted similar effects. These data suggest that edoxaban enhanced fibrinolysis via inhibition of TAFI activation and enhancement of plasmin generation. DisclosuresMorishima:Daiichi Sankyo Co., Ltd.: Employment. Honda:Daiichi Sankyo Co., Ltd.: Employment. Furugohri:Daiichi Sankyo Co., Ltd.: Employment.

Anti-thrombotic activity of isolated β-sitosterol from roots of Hemidesmus indicus Linn in rat model

Thrombosis is the basic pathophysiological procedure, brings about majority strokes and heart attacks which are serious causes of death all over the world. The present work was aimed to study the anti-thrombotic activity of isolated compound β-sitosterol (BS) from roots of herb Anantamul (Hemidesmus indicus Linn). A number of engrossing biomedical properties have been attributed to BS. Anti-thrombotic activity was evaluated by in-vitro analysis of different experimental paradigm i.e. Free radical scavenging activity, Clot lysis assay, Malondialdehyde (MDA) production in blood platelets and in-vivo models such as Rat arterio-venous shunt silk thread model, Rat venous thrombosis model, Carrageenan induced thrombosis. The statistical results obtained from the experimental models inferred that isolated BS imputed to its anti-thrombotic activity due to the anti-oxidant property, clot lysis property, inhibition of lipid peroxidation in platelet, inhibition of platelet lysis and effect on coagulation cascade.

The effect of Diosmin on the blood proteome in a rat model of venous thrombosis

Diosmin is the aglycone moiety of diosmetin (3′,5,7 trihydroxy-4′methoxy radicals flavonoids), a naturally occurring flavone glycoside, whose antithrombotic effect was studied in rats. This study was designed to find the protein changes of venous thrombosis in Wistar rats comparing conditions with and without Diosmin treatment by two-dimensional gel electrophoresis (2-DE), and investigate the effect of a crucial protein known as CEP350 on human vascular endothelial cell growth.Through prior chromatographic purification with macroporous absorption resin (AB-8) and polyamide, Diosmin was isolated from Galium verum L. by solvent extraction, then purified to 98% purity using HPLC. Wistar rats were divided into control group, model group, and prevention group. And their venous thrombosis tissue segments were dissected and prepared for histopathological examination and detection of plasma protein C (PC). Next, proteomic analysis was performed with the samples. Low-abundance proteins of the three groups were separated by two-dimensional gel electrophoresis (2-DE). 2-DE analysis revealed that 191 protein spots were differentially expressed among those three groups. For protein identification, we selected six spots to use matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) detection, and then do the homology search in NCBI database. Considering characteristics of these proteins, we proposed CEP350 is related to spindle assembly. Furthermore, we used Lipofectamine 2000 to transfect HUVECs with CEP350 siRNA and evaluated the extent of silencing using real time–polymerase chain reaction (RT-PCR). Cells were stained for immunofluorescence with tubulin-tracker red, and structural changes were analyzed using laser scanning confocal microscope.We concluded that CEP350 depletion decreased microtubule stability. Dosmin could modulate the assemble of spindle from unevenly distributing and protect body from varicose veins by regulating CEP350.

Edoxaban improves venous thrombosis via increasing hydrogen sulfide and homocysteine in rat model.

Anticoagulant therapy is prescribed to millions of patients worldwide for the prevention and treatment of venous thrombosis. Evidence has indicated that edoxaban is a potential drug of oral anticoagulant in the acute treatment of venous thromboembolism. Hydrogen sulfide and homocysteine plasma concentration are indicators of cardiovascular and neurovascular disease risk factors that have attracted considerable attention for regulation of vascular health and homeostasis. However, the molecular mechanism of edoxaban‑mediated differences of hydrogen sulfide and homocysteine has not been investigated in the progression of venous thrombosis. In the present study, the authors analyzed the phosphoinositide 3‑kinase (PI3K)/protein kinase B (AKT) signaling pathway in the vein endothelial cells and expression levels of hydrogen sulfide and homocysteine. Homocysteine‑hydrogen sulfide metabolism through transsulfuration and that transsulfuration capacity and hydrogen sulfide availability have been investigated both invitro and invivo following treatment with edoxaban. Matrix metalloproteinase (MMP) activation and cystathionine β‑synthase (CBS) and cystathionine γ‑lyase (CGL) levels were studied in a cell model and rat model of vein thrombosis prior and post treatment of edoxaban. The therapeutic effects of edoxaban for rats with vein thrombosis were determined by clinical diagnose scores. The results demonstrated that edoxaban increased expression levels of hydrogen sulfide and homocysteine in microvascular endothelial cells. It was observed that the transsulfuration enzymes, CBS and CGL levels were upregulated in murine microvascular endothelial cells. The MMP‑9 expression level and activity and homocysteine‑hydrogen sulfide metabolism were increased in murine microvascular endothelial cells following edoxaban treatment. In addition, CBS and CGL activities were upregulated in murine microvascular endothelial cells and a rat model of venous thrombosis following treatment with edoxaban. Furthermore, it was observed that edoxaban increased PI3K and AKT expression both invitro and invivo. In addition, edoxaban significantly improved endothelial injury and inhibited thrombosis factors expression in rat model of venous thrombosis. In conclusion, these findings suggested that edoxaban can improve venous thrombosis by decreasing hydrogen sulfide and homocysteine through the PI3K/AKT signaling pathway.

Design, synthesis and antithrombotic evaluation of novel non-peptide thrombin inhibitors

Ten derivatives of 4-((1,2,3,4-tetrahydrobenzo[4,5]imidazo[1,2-a]pyrazin-1-yl)methyl)benzimida-mide (I-1∼I-2, II-1∼II-8) were designed, synthesized and evaluated for their inhibitory effect on human thrombin. Compound II-7 (IC50=82.8nM), which showed the strongest thrombin inhibitory activity among the tested compounds, was chosen as the lead compound, and ten carbamate derivatives (II-9a∼II-13a, II-9b∼II-12b, II-14) were prepared and evaluated for their anticoagulant activity. The results indicate that most of the tested compounds exhibit a certain degree of inhibitory effect on thrombin-induced platelet aggregation, among which compounds II-11a (IC50=8.16μM) and II-14 (IC50=1.95μM) show better anti-platelet aggregation activity than the others. The in vivo experimental results in rat venous thrombosis model also demonstrate compounds II-11a and II-14 can significantly reduce thrombosis in a dose-response manner. It is worth pointing out that the enhanced potency of compound II-14 may be the synergetic effect of 2-hydroxymethyl-3,5,6-trimethylpyrazine (HTMP) and II-7 which are generated by hydrolysis in vivo.

Development of PEG-PLGA based Intravenous Low Molecular Weight Heparin (LMWH) Nanoparticles Intended to Treat Venous Thrombosis.

Anticoagulant therapy is effective in the treatment of DVT. In this regard, LMWH demonstrated significant promise. It is widely used clinically. The goal of this study was to prepare and evaluate intravenous sustained release stealth nanoparticles encapsulating LMWH using PLGA (polylactidecoglycolide) and different grades of PEG (poly ethylene glycols). The nanoparticles were prepared using w/o/w solvent evaporation technique. Prepared nanoparticles were evaluated for particle size, encapsulation efficiency, in-vitro drug release, anti-thrombotic activity in venous thrombosis rat model, estimation of aPTT, tissue bio-distribution studies and stability. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) studies confirmed the formation of smooth spherical particles. FTIR study reveals successful coating of PEG on the nanoparticles. DSC and XRD results demonstrated that drug changed its physical form in the formulation. The encapsulation efficiency was 63-74%. In vitro drug release was 57-75% for 48 hrs. Macrophage uptake of LMWH with pegylated nanoparticles was less compared to conventional PLGA nanoparticles. In vivo drug release was sustained for 48hrs; Optimized formulation exhibited good enhancement in pharmacokinetic parameters when compared to free drug solution. In vivo sustained release was also demonstrated with antithrombotic activity as well aPTT activity. Optimized formulation demonstrated significant stability, excellent antithrombotic activity in venous thrombosis rat model, improved aPTT levels when compared to free drug solution. An effective stealth LMWH nanoparticle formulation to treat venous thrombosis was successfully developed using w/o/w solvent evaporation technique.

Exploiting the antithrombotic effect of the (pro)thrombin inhibitor bothrojaracin

Bothrojaracin is a 27 kDa C-type lectin-like protein from Bothrops jararaca snake venom. It behaves as a potent thrombin inhibitor upon high-affinity binding to thrombin exosites. Bothrojaracin also forms a stable complex with prothrombin that can be detected in human plasma. Formation of the zymogen-inhibitor complex severely decreases prothrombin activation and contributes to the anticoagulant activity of bothrojaracin. In the present study, we employed two rodent models to evaluate the antithrombotic effect of bothrojaracin in vivo: stasis-induced thrombosis and thrombin-induced pulmonary thromboembolism. It was observed that bothrojaracin interacts with rat prothrombin in plasma. Ex-vivo assays showed stable complex formation even after 24 h of a single bothrojaracin dose. As a result, bothrojaracin showed significant antithrombotic activity in a rat venous thrombosis model elicited by thromboplastin combined with stasis. The antithrombotic activity of bothrojaracin (1 mg/kg) persisted for up to 24 h and it was associated with moderate bleeding as assessed by a tail transection method. Formation of bothrojaracin-prothrombin complex has been also observed following intravenous administration of the inhibitor into mice. As a result, bothrojaracin effectively protected mice from thrombin-induced fatal thromboembolism. We conclude that bothrojaracin is a potent antithrombotic agent in vivo and may serve as a prototype for the development of new zymogen-directed drugs that could result in prolonged half-life and possible decreased hemorrhagic risk.

Upregulation of miR-483-3p contributes to endothelial progenitor cells dysfunction in deep vein thrombosis patients via SRF.

BackgroundEndothelial progenitor cells (EPCs) contribute to recanalization of deep vein thrombosis (DVT). This study aimed to detect miRNA expression profiles in EPCs from patients with DVT and characterize the role of miRNA in EPCs dysfunction.MethodsEPCs was isolated from DVT patients and control subjects, and miRNA expression profiles were compared to screen differential miRNAs. The candidate miRNAs were confirmed by RT-PCR analysis. The targets of miRNA were identified by bioinformatics analyses, luciferase reporter assay and gene expression analyses. The apoptosis, migration and tube formation of EPCs were examined by flow cytometry, transwell assay and matrigel tube formation assay. A rat model of venous thrombosis was established as in vivo model.ResultsWe identified miR-483-3p as a candidate miRNA upregulated in EPCs from DVT patients. By using miR-483-3p agomir and antagomir, we demonstrated that miR-483-3p decreased the migration and tube formation while increased the apoptosis of EPCs. Moreover, we identified serum response factor (SRF) as the target of miR-483-3p, and showed that SRF knockdown decreased the migration and tube formation while increased the apoptosis of EPCs. In addition, miR-483-3p inhibition led to enhanced ability of homing and thrombus resolution of EPCs in rat model of venous thrombosis.ConclusionsmiR-483-3p is upregulated in EPCs from DVT patients, and it targets SRF to decrease EPCs migration and tube formation and increase apoptosis in vitro, while decrease EPCs homing and thrombus resolution in vivo. MiR-483-3p is a potential therapeutic target in DVT treatment.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-016-0775-2) contains supplementary material, which is available to authorized users.