scholarly journals Selective depletion of plasma prekallikrein or coagulation factor XII inhibits thrombosis in mice without increased risk of bleeding

Blood ◽  
2011 ◽  
Vol 118 (19) ◽  
pp. 5302-5311 ◽  
Author(s):  
Alexey S. Revenko ◽  
Dacao Gao ◽  
Jeff R. Crosby ◽  
Gourab Bhattacharjee ◽  
Chenguang Zhao ◽  
...  
Keyword(s):  
Ischemia Reperfusion Injury ◽  
Thrombus Formation ◽  
Ischemia Reperfusion ◽  
Coagulation Factor ◽  
Selective Reduction ◽  
Contact System ◽  
Factor Xii ◽  
Increased Risk ◽  
Cerebral Ischemia Reperfusion Injury

AbstractRecent studies indicate that the plasma contact system plays an important role in thrombosis, despite being dispensable for hemostasis. For example, mice deficient in coagulation factor XII (fXII) are protected from arterial thrombosis and cerebral ischemia-reperfusion injury. We demonstrate that selective reduction of prekallikrein (PKK), another member of the contact system, using antisense oligonucleotide (ASO) technology results in an antithrombotic phenotype in mice. The effects of PKK deficiency were compared with those of fXII deficiency produced by specific ASO-mediated reduction of fXII. Mice with reduced PKK had ∼ 3-fold higher plasma levels of fXII, and reduced levels of fXIIa-serpin complexes, consistent with fXII being a substrate for activated PKK in vivo. PKK or fXII deficiency reduced thrombus formation in both arterial and venous thrombosis models, without an apparent effect on hemostasis. The amount of reduction of PKK and fXII required to produce an antithrombotic effect differed between venous and arterial models, suggesting that these factors may regulate thrombus formation by distinct mechanisms. Our results support the concept that fXII and PKK play important and perhaps nonredundant roles in pathogenic thrombus propagation, and highlight a novel, specific and safe pharmaceutical approach to target these contact system proteases.

scholarly journals Coagulation factor XII in thrombosis and inflammation

Blood ◽  
2018 ◽  
Vol 131 (17) ◽  
pp. 1903-1909 ◽  
Author(s):  
Coen Maas ◽  
Thomas Renné
Keyword(s):  
Thrombus Formation ◽  
Coagulation Factor ◽  
Contact System ◽  
Inflammatory Disorder ◽  
Factor Xii ◽  
Kinin System ◽  
Disease States ◽  
Exciting Opportunity

Abstract Combinations of proinflammatory and procoagulant reactions are the unifying principle for a variety of disorders affecting the cardiovascular system. The factor XII–driven contact system starts coagulation and inflammatory mechanisms via the intrinsic pathway of coagulation and the bradykinin-producing kallikrein-kinin system, respectively. The biochemistry of the contact system in vitro is well understood; however, its in vivo functions are just beginning to emerge. Challenging the concept of the coagulation balance, targeting factor XII or its activator polyphosphate, provides protection from thromboembolic diseases without interfering with hemostasis. This suggests that the polyphosphate/factor XII axis contributes to thrombus formation while being dispensable for hemostatic processes. In contrast to deficiency in factor XII providing safe thromboprotection, excessive FXII activity is associated with the life-threatening inflammatory disorder hereditary angioedema. The current review summarizes recent findings of the polyphosphate/factor XII–driven contact system at the intersection of procoagulant and proinflammatory disease states. Elucidating the contact system offers the exciting opportunity to develop strategies for safe interference with both thrombotic and inflammatory disorders.

scholarly journals In vivo roles of factor XII

Blood ◽  
2012 ◽  
Vol 120 (22) ◽  
pp. 4296-4303 ◽  
Author(s):  
Thomas Renné ◽  
Alvin H. Schmaier ◽  
Katrin F. Nickel ◽  
Margareta Blombäck ◽  
Coen Maas
Keyword(s):  
Thrombus Formation ◽  
Coagulation Factor ◽  
Special Focus ◽  
Factor Xii ◽  
Excessive Bleeding ◽  
Charged Surfaces ◽  
Factor Xiia ◽  
Knockout Model

Abstract Coagulation factor XII (FXII, Hageman factor, EC = 3.4.21.38) is the zymogen of the serine protease, factor XIIa (FXIIa). FXII is converted to FXIIa through autoactivation induced by “contact” to charged surfaces. FXIIa is of crucial importance for fibrin formation in vitro, but deficiency in the protease is not associated with excessive bleeding. For decades, FXII was considered to have no function for coagulation in vivo. Our laboratory developed the first murine knockout model of FXII. Consistent with their human counterparts, FXII−/− mice have a normal hemostatic capacity. However, thrombus formation in FXII−/− mice is largely defective, and the animals are protected from experimental cerebral ischemia and pulmonary embolism. This murine model has created new interest in FXII because it raises the possibility for safe anticoagulation, which targets thrombosis without influence on hemostasis. We recently have identified platelet polyphosphate (an inorganic polymer) and mast cell heparin as in vivo FXII activators with implications on the initiation of thrombosis and edema during hypersensitivity reactions. Independent of its protease activity, FXII exerts mitogenic activity with implications for angiogenesis. The goal of this review is to summarize the in vivo functions of FXII, with special focus to its functions in thrombosis and vascular biology.

scholarly journals Targeted Delivery of Intranasally Administered Cyclovirobuxine D Liposomes to Brain for Treatment Cerebral Ischemia-Reperfusion Injury via Anti-oxidative Stress and Activating Autophagy

2022 ◽  
Author(s):  
Tuo Liu ◽  
Fang Yang ◽  
Xiangyi Lu ◽  
Chang Liu ◽  
Yang Yu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Viability ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Cerebral Ischemia Reperfusion ◽  
Protein Expressions ◽  
Cerebral Ischemia Reperfusion Injury ◽  
Ht22 Cell

Abstract The lack of effective therapy mandates development of treatment for cerebral ischemia-reperfusion injury (CIRI. The previous study suggested that Cyclovirobuxine D (CVBD) encapsulated in Angiopep-conjugated Polysorbate 80-Coated Liposomes showed a better brain targeting by intranasal administration. Therefore, this study focused on the protection and mechanism of CVBD brain-targeted liposomes in treating CIRI. In order to evaluate these, the CIRI rat model was induced by middle cerebral artery occlusion (MCAO)-reperfusion. Pharmacological evaluation was assessed in vivo by general indexs, neurobehavioral scores, triphenyl tetrazolium chloride (TTC) staining, histopathological staining (HE staining and Nissl staining), small animal magnetic resonance imaging, biochemical assay and Western blot. The results show that CVBD liposomes alleviated pathological damage of brain. Futhermore, the protective effect of CVBD liposomes on OGD/R-injured HT22 cell was investigated by cell fusion degree, cell proliferation curve and cell viability. OGD/R-injured HT22 cell was infected by mRFP-GFP-LC3 adenovirus. The autophagosome and autophagy flow were observed by laser confocal microscopy, and autophagy-related protein expressions (LC3, p62 and Beclin 1) were analyzed by Western blot. Meanwhile, the classic autophagy inhibitor, chloroquine, was used to explore the autophagy-regulated mechanism of CVBD brain-targeted liposomes in treating CIRI. In cell model of oxygen and glucose deprivation/re-oxygenation, CVBD liposomes increased cell viability and decreased ROS level. CVBD liposomes improved oxidative stress protein expressions and activated autophagy in vitro. Furthermore, CVBD liposomes reversed the decrease of cell viability, increase of ROS level, and reduction of protein expressions associated to anti-oxidative stress and autophagy induced by chloroquine. Collectively, CVBD liposomes inhibited CIRI via regulating oxidative stress and enhancing autophagy level in vivo and in vitro, showing a great potential in treating CIRI in clinic.

scholarly journals OM-MSCs Alleviate the Golgi Apparatus Stress Response following Cerebral Ischemia/Reperfusion Injury via the PEDF-PI3K/Akt/mTOR Signaling Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Jialin He ◽  
Jianyang Liu ◽  
Yan Huang ◽  
Xiangqi Tang ◽  
Han Xiao ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Stress Response ◽  
Cerebral Ischemia ◽  
Stress Responses ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Cerebral Ischemia Reperfusion ◽  
Cerebral Ischemia Reperfusion Injury

The mechanism of Golgi apparatus (GA) stress responses mediated by GOLPH3 has been widely studied in ischemic stroke, and the neuroprotection effect of olfactory mucosa mesenchymal stem cells (OM-MSCs) against cerebral ischemia/reperfusion injury (IRI) has been preliminarily presented. However, the exact role of OM-MSCs in the GA stress response following cerebral IRI remains to be elucidated. In the present study, we used an oxygen-glucose deprivation/reoxygenation (OGD/R) model and reversible middle cerebral artery occlusion (MCAO) model to simulate cerebral IRI in vitro and in vivo. Our results showed that the level of GOLPH3 protein, reactive oxygen species (ROS), and Ca2+ was upregulated, SPCA1 level was downregulated, and GA fragmentation was increased in ischemic stroke models, and OM-MSC treatment clearly ameliorated these GA stress responses in vitro and in vivo. Subsequently, the knockdown of PEDF in OM-MSCs using PEDF-specific siRNA further demonstrated that secretion of PEDF in OM-MSCs protected OGD/R-treated N2a cells and MCAO rats from GA stress response. Additionally, rescue experiment using specific pathway inhibitors suggested that OM-MSCs could promote the phosphorylation of the PI3K/Akt/mTOR pathway, thereby mitigating OGD/R-induced GA stress response and excessive autophagy. In conclusion, OM-MSCs minimized the GA stress response following cerebral IRI, at least partially, through the PEDF-PI3K/Akt/mTOR pathway.

scholarly journals Improvement of Cerebral Ischemia-Reperfusion Injury via Regulation of Apoptosis by Exosomes Derived from BDNF-Overexpressing HEK293

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Lizong Wang ◽  
Jinghan Jiang ◽  
Taofeng Zhou ◽  
Xiang Xue ◽  
Yongjun Cao
Keyword(s):  
Cerebral Ischemia ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Hek293 Cells ◽  
Neuroprotective Effects ◽  
In Vivo Experiments ◽  
Cerebral Ischemia Reperfusion ◽  
Cerebral Ischemia Reperfusion Injury ◽  
Induced Apoptosis

Brain-derived neurotrophic factor (BDNF) provides neuroprotective effects towards therapeutic cerebral ischemia-reperfusion (I/R) injury. This view has been proposed by more and more evidence. However, due to the lack of permeability of the blood-brain barrier (BBB) as well as the brief half-life in serum, clinical application is not widespread. To study the participation of exosomes containing BDNF in I/R, we isolated exosomes from BDNF-overexpressing HEK293. The protective outcomes of exosomes in hypoxia/reoxygenation (H/R) experiments were determined by the use of SY-5Y cells. Exosome-BDNF therapy restrained H/R-induced apoptosis by inhibition of the reducing levels of oxidative stress and calcium ions in the cells while maintaining stable levels of mitochondrial membrane potential in brain cells damaged by I/R. We then constructed a cerebral I/R injury model using SD rats to find the function of BDNF in exosome-mediated neuroprotection. The in vivo experiments conducted established that exosomes from BDNF-overexpressing HEK293 cells improved cerebral I/R injury by concealing neuronal apoptosis. Findings gained demonstrated that BDNF is a part of preventing cerebral I/R injury due to exosome mediation by regulating the cellular internal environment and inhibiting apoptosis.

Loss of Sema4D Signaling in Platelets Impairs the Formation and Stability of Arterial Thrombi In Vivo and Reduces Myocardial Infarct Size.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3631-3631 ◽  
Author(s):  
Li Zhu ◽  
Timothy J. Stalker ◽  
Tao Wang ◽  
Hong Jiang ◽  
Atushi Kumanogoh ◽  
...  
Keyword(s):  
Infarct Size ◽  
Platelet Function ◽  
Ischemia Reperfusion Injury ◽  
Thrombus Formation ◽  
Infarct Volume ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Myocardial Infarct Size ◽  
Cremaster Muscle

Abstract Contact-dependent signaling between platelets helps to promote thrombus growth and stability. One mechanism for contact-dependent signaling involves the binding of cell surface ligands to corresponding receptors on the surface of adjacent cells. In our efforts to identify novel participants in this process, we have recently reported that platelets express on their surface the semaphorin family member, sema4D, and its two known receptors, CD72 and plexin-B1 (Zhu, et al, PNAS, 2007). We have also shown that although their initial tail bleeding time is normal, platelets from sema4D(−/−) mice have a defect in collagen-induced signaling and platelet aggregation in vitro. In the present studies, we used matched sema4D(−/−) and wild type (WT) mice to examine the consequences of impaired sema4D signaling in models of platelet function in vivo. In the first model, irradiated Rose Bengal dye was used to produce an arteriolar injury in an exteriorized cremaster muscle. Platelets were identified with a fluorescent CD41 antibody and detected in real time using digital microscopy. The results showed that thrombus formation occurred in all of the mice that were tested, but while stable occlusion was observed in approximately half of the control mice, none of the sema4D(−/−) mice developed stable occlusions during the period of observation (p<0.02). Similarly, when a laser was used to produce a focal injury in cremaster muscle arterioles, both the initial rate of platelet accumulation and the peak extent of accumulation were approximately 50% lower in the sema4D(−/−) mice than in the matched controls. To test the contribution of sema4D to platelet responses in a larger artery, the right common carotid was injured by transient exposure to FeCl3 and changes in flow were measured using a Doppler probe. The results showed that the time to occlusion was 35% greater in the sema4D(−/−) mice than in controls (p<0.02). Furthermore, stable occlusion occurred in only 9 of 16 (56%) sema4D(−/−) mice Vs. 7 of 9 (78%) WT mice. Finally, myocardial infarct size was measured in an ischemia/reperfusion injury model 48 hrs after transient ligation of the left anterior descending coronary artery. Although infarction occurred in all cases, infarct volume was 56% smaller in the sema4D(−/−) mice than the matched controls (p<0.01). In summary, these results show that there is a substantial impairment of platelet function in vivo in mice that lack sema4D. This impairment was observed in both arterioles and arteries using several different methods to evoke platelet activation. When combined with our earlier observations, the results show that signaling by sema4D and its receptors provides a novel mechanism to promote thrombus growth and stability.

LncRNA MEG3 regulates microglial polarization through KLF4 to affect cerebral ischemia-reperfusion injury

2020 ◽  
Vol 129 (6) ◽  
pp. 1460-1467
Author(s):  
Tianhao Li ◽  
Yuru Luo ◽  
Peng Zhang ◽  
Shewei Guo ◽  
Hongwei Sun ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Noncoding Rna ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Microglial Polarization ◽  
In Vivo Experiments ◽  
Cerebral Ischemia Reperfusion ◽  
Cerebral Ischemia Reperfusion Injury

To study the role of long noncoding RNA (lncRNA) maternally expressed gene 3 (MEG3) in cerebral ischemia-reperfusion (I/R) injury, we clarified the mechanism by which lncRNA MEG3 regulates the secretion of inflammatory cytokines in microglia through in vitro and in vivo experiments. We discovered that inhibition of MEG3 could alleviate cerebral I/R injury via inhibiting M1 polarization and promoting M2 polarization through Krüppel-like factor 4 (KLF4), indicating an effective theoretical basis for potential therapeutic targets of cerebral I/R injury.

Sign in / Sign up

Export Citation Format

Share Document