Kindlin-3 in platelets and myeloid cells differentially regulates deep vein thrombosis in mice

Comparison of different machine learning classification models for predicting deep vein thrombosis in lower extremity fractures

Deep vein thrombosis (DVT) is a common complication in patients with lower extremity fractures. Once it occurs, it will seriously affect the quality of life and postoperative recovery of patients. Therefore, early prediction and prevention of DVT can effectively improve the prognosis of patients. This study constructed different machine learning models to explore their effectiveness in predicting DVT. Five prediction models were applied to the study, including Extreme Gradient Boosting (XGBoost) model, Logistic Regression (LR) model, RandomForest (RF) model, Multilayer Perceptron (MLP) model, and Support Vector Machine (SVM) model. Afterwards, the performance of the obtained prediction models was evaluated by area under the curve (AUC), accuracy, sensitivity, specificity, F1 score, and Kappa. The prediction performances of the models based on machine learning are as follows: XGBoost model (AUC = 0.979, accuracy = 0.931), LR model (AUC = 0.821, accuracy = 0.758), RF model (AUC = 0.970, accuracy = 0.921), MLP model (AUC = 0.830, accuracy = 0.756), SVM model (AUC = 0.713, accuracy = 0.661). On our data set, the XGBoost model has the best performance. However, the model still needs external verification research before clinical application.

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.

The role of neutrophils in chorioamnionitis

Chorioamnionitis, commonly referred to as intrauterine infection or inflammation, is pathologically defined by neutrophil infiltration and inflammation at the maternal-fetal interface. Chorioamnionitis is the common complication during late pregnancy, which lead to a series of serious consequences, such as preterm labor, preterm premature rupture of the fetal membranes, and fetal inflammatory response syndrome. During infection, a large number of neutrophils migrate to the chorio-decidua in response to chemokines. Although neutrophils, a crucial part of innate immune cells, have strong anti-inflammatory properties, over-activating them can harm the body while also eliminating pathogens. This review concentrated on the latest studies on chorioamnionitis-related consequences as well as the function and malfunction of neutrophils. The release of neutrophil extracellular traps, production of reactive oxygen species, and degranulation from neutrophils during intrauterine infection, as well as their pathological roles in complications related to chorioamnionitis, were discussed in detail, offering fresh perspectives on the treatment of chorioamnionitis.

Circulating LPS from gut microbiota leverages stenosis-induced deep vein thrombosis in mice

OBJECTIVE AND DESIGN

An accumulating body of evidence has shown that gut microbiota is involved in regulating inflammation; however, it remains undetermined if and how gut microbiota plays an important role in modulating deep venous thrombosis (DVT), which is an inflammation-involved thrombotic event.

SUBJECTS

Mice under different treatments were used in this study.

METHODS AND TREATMENT

We induced stenosis DVT in mice by partially ligating the inferior vena cava. Mice were treated with antibiotics, prebiotics, probiotics, or inflammatory reagents to modulate inflammatory states, and their effects on the levels of circulating LPS and DVT were examined.

RESULTS

Antibiotic-treated mice or germ-free mice exhibited compromised DVT. Treatment of mice with either prebiotics or probiotics effectively suppressed DVT, which was accompanied with the downregulation of circulating LPS. Restoration of circulating LPS in these mice with a low dose of LPS was able to restore DVT. LPS-induced DVT was blocked by a TLR4 antagonist. By performing proteomic analysis, we identified TSP1 as one of the downstream effectors of circulating LPS in DVT.

CONCLUSION

These results suggest that gut microbiota may play a nonnegligible role in modulating DVT by leveraging the levels of LPS in circulation, thus shedding light on the development of gut microbiota-based strategies for preventing and treating DVT.

Role of neutrophil extracellular traps in inflammatory evolution in severe acute pancreatitis

ABSTRACT

Severe acute pancreatitis (SAP) is a life-threatening acute abdominal disease with two peaks of death: the first in the early stage, characterized by systemic inflammatory response-associated organ failure; and the second in the late stage, characterized by infectious complications. Neutrophils are the main immune cells participating in the whole process of SAP. In addition to the traditional recognition of neutrophils as the origination of chemokine and cytokine cascades or phagocytosis and degranulation of pathogens, neutrophil extracellular traps (NETs) also play an important roles in inflammatory reactions. We reviewed the role of NETs in the occurrence and development of SAP and its fatal complications, including multiple organs injury, infected pancreatic necrosis, and thrombosis. This review provides novel insights into the involvement of NETs throughout the entire process of SAP, showing that targeting NETs might be a promising strategy in SAP treatment. However, precision therapeutic options targeting NETs in different situations require further investigation.

Immunothrombosis and the Role of Platelets in Venous Thromboembolic Diseases

Venous thromboembolism (VTE) is the third leading cardiovascular cause of death and is conventionally treated with anticoagulants that directly antagonize coagulation. However, recent data have demonstrated that also platelets play a crucial role in VTE pathophysiology. In the current review, we outline how platelets are involved during all stages of experimental venous thrombosis. Platelets mediate initiation of the disease by attaching to the vessel wall upon which they mediate leukocyte recruitment. This process is referred to as immunothrombosis, and within this novel concept inflammatory cells such as leukocytes and platelets directly drive the progression of VTE. In addition to their involvement in immunothrombosis, activated platelets can directly drive venous thrombosis by supporting coagulation and secreting procoagulant factors. Furthermore, fibrinolysis and vessel resolution are (partly) mediated by platelets. Finally, we summarize how conventional antiplatelet therapy can prevent experimental venous thrombosis and impacts (recurrent) VTE in humans.

The combination of danhong injection plus tissue plasminogen activator ameliorates mouse tail thrombosis-induced by κ-carrageenan

BACKGROUND

After thrombosis, t-PA thrombolysis is the first choice, but the use of t-PA can easily lead to hemorrhagic injury and neurotoxicity. The combination of Danhong injection (DHI) and tissue plasminogen activator (t-PA) therapy may be a new strategy to find high-efficiency anti-thrombosis and low bleeding risk. However, nothing is about the effect of DHI plus t-PA on platelet activation.

PURPOSE

The present research was to explore the optimal dose of DHI and t-PA in vivo and mechanisms involved with the treatment of combining DHI and t-PA for thrombotic disease and determined whether DHI plus t-PA affects thrombotic processes related to platelet activation.

METHODS

Mice were induced by administering κ-carrageenan intraperitoneally, the ratio of different doses of DHI and t-PA in vivo, and the optimal dose effects on platelet aggregation, platelet adhesion, thrombosis formation, and platelet activation were determined. The effects of the αIIbβ3 signaling pathway were analyzed in mice.

RESULTS

In vitro, DHI (62% v/v), t-PA (1 mg/ml), and DHI + t-PA (62% v/v + 1 mg/ml) decreased rat platelet aggregation and adhesion, with a stronger effect from the combination as compared to t-PA monotherapy. In vivo, injections of κ-carrageenan were used to induce BALB/c mice. The optimal dose of DHI, t-PA, and DHI + t-PA is 12 ml/kg, 10 mg/kg, and 12 ml/kg + 7.5 mg/kg. The administration of DHI (12 ml/kg), t-PA (10 mg/kg), and DHI + t-PA (12 ml/kg + 7.5 mg/kg) decreased thrombi in mouse tissue vessels. Furthermore, the reduction of thrombosis formation by DHI, t-PA, and DHI + t-PA was related to lower collagen deposition, and lowered expressions of collagen I, matrix metalloproteinase 2 (MMP-2), and metalloproteinase 9 (MMP-9) in mouse tails, with increased efficacy in combination as compared to t-PA alone. The anti-thrombosis actions of DHI, t-PA, and their combination regulated the expression of CD41, purinergic receptor (P2Y₁₂), guanine nucleotide-binding protein G (q) subunit alpha (GNAQ), phosphatidylinositol phospholipase c beta (PLCβ), Ras-related protein 1 (Rap1), RIAM, talin1, fibrinogen alpha chain (FG), kindlin-3, and RAS guany1-releasing protein 1 (RasGRP1).

CONCLUSIONS

Based on expression, the mechanism responsible for thrombosis may be attributed to platelet activation via the αIIbβ3 signaling pathway. Combination therapy with DHI and t-PA exerted potent thrombolytic effects. Thus, our data can be used as a foundation for further clinical studies examining the efficacy of traditional Chinese medicines for the treatment of thrombosis.

Platelets in the NETworks interweaving inflammation and thrombosis

Platelets are well characterized for their indispensable role in primary hemostasis to control hemorrhage. Research over the past years has provided a substantial body of evidence demonstrating that platelets also participate in host innate immunity. The surface expression of pattern recognition receptors, such as TLR2 and TLR4, provides platelets with the ability to sense bacterial products in their environment. Platelet α-granules contain microbicidal proteins, chemokines and growth factors, which upon release may directly engage pathogens and/or contribute to inflammatory signaling. Additionally, platelet interactions with neutrophils enhance neutrophil activation and are often crucial to induce a sufficient immune response. In particular, platelets can activate neutrophils to form neutrophil extracellular traps (NETs). This specific neutrophil effector function is characterized by neutrophils expelling chromatin fibres decorated with histones and antimicrobial proteins into the extracellular space where they serve to trap and kill pathogens. Until now, the mechanisms and signaling pathways between platelets and neutrophils inducing NET formation are still not fully characterized. NETs were also detected in thrombotic lesions in several disease backgrounds, pointing towards a role as an interface between neutrophils, platelets and thrombosis, also known as immunothrombosis. The negatively charged DNA within NETs provides a procoagulant surface, and in particular NET-derived proteins may directly activate platelets. In light of the current COVID-19 pandemic, the topic of immunothrombosis has become more relevant than ever, as a majority of COVID-19 patients display thrombi in the lung capillaries and other vascular beds. Furthermore, NETs can be found in the lung and other tissues and are associated with an increased mortality. Here, virus infiltration may lead to a cytokine storm that potently activates neutrophils and leads to massive neutrophil infiltration into the lung and NET formation. The resulting NETs presumably activate platelets and coagulation factors, further contributing to the subsequent emergence of microthrombi in pulmonary capillaries. In this review, we will discuss the interplay between platelets and NETs and the potential of this alliance to influence the course of inflammatory diseases. A better understanding of the underlying molecular mechanisms and the identification of treatment targets is of utmost importance to increase patients’ survival and improve the clinical outcome.

Blockage of PD-L1 by FERMT3-mediated Wnt/β-catenin signaling regulates chemoresistance and immune evasion of colorectal cancer cells

Colorectal cancer (CRC) constitutes a major public health problem due to the high rate of morbidity and mortality. Chemotherapy and immunotherapy are the major and promising strategies for cancer patients including CRC; nevertheless, chemoresistance and immune escape limit the final efficacy of above approaches. FERMT3 has been proved to exert the critical role in immune system and contradictive effects on cancer progression. In this study, bioinformatics database analysis and clinical specimen detection both corroborated the down-regulation of FERMT3 in CRC tissues and cells. Of interest, overexpression of FERMT3 suppressed CRC cell invasion and sensitized cells to 5-fluorouracil (5-FU) by reducing cell viability and increasing cell apoptosis and caspase-3 activity. Noticeably, FERMT3 up-regulation enhanced natural killer (NK) cells activation by increasing secretions of IFN-γ and TNF-α when NK cells were co-cultured with CRC cells. Importantly, up-regulation of FERMT3 promoted NK cell-mediated killing of CRC cells. Mechanically, FERMT3 inhibited the aberrant activation of Wnt/β-catenin signaling and the subsequent PD-L1 expression in CRC cells. Moreover, targeting PD-L1 suppressed CRC cell invasion, 5-FU resistance and NK cells-mediated tumor killing. Additionally, reactivating the Wnt/β-catenin signaling with a specific WNT agonist CAS 853220-52-7 overturned the efficacy of FERMT3 overexpression against CRC cell invasion, 5-FU chemoresistance and cell susceptibility to NK cell-mediated cytotoxicity. Thus, the current findings substantiate that FERMT3 elevation may attenuate CRC cell chemoresistance and NK cell-mediated immune response to tumor cells by inhibiting Wnt/β-catenin-PD-L1 signaling. Therefore, FERMT3 elevation may be a promising therapeutic approach to overcome chemoresistance and immune evasion in CRC. This article is protected by copyright. All rights reserved.

Endothelial Dysfunction Induced by Extracellular Neutrophil Traps Plays Important Role in the Occurrence and Treatment of Extracellular Neutrophil Traps-Related Disease

Many articles have demonstrated that extracellular neutrophil traps (NETs) are often described as part of the antibacterial function. However, since the components of NETs are non-specific, excessive NETs usually cause inflammation and tissue damage. Endothelial dysfunction (ED) caused by NETs is the major focus of tissue damage, which is highly related to many inflammatory diseases. Therefore, this review summarizes the latest advances in the primary and secondary mechanisms between NETs and ED regarding inflammation as a mediator. Moreover, the detailed molecular mechanisms with emphasis on the disadvantages from NETs are elaborated: NETs can use its own enzymes, release particles as damage-associated molecular patterns (DAMPs) and activate the complement system to interact with endothelial cells (ECs), drive ECs damage and eventually aggravate inflammation. In view of the role of NETs-induced ED in different diseases, we also discussed possible molecular mechanisms and the treatments of NETs-related diseases.

Mesenchymal stem cell treatment improves outcome of COVID-19 patients via multiple immunomodulatory mechanisms

The infusion of coronavirus disease 2019 (COVID-19) patients with mesenchymal stem cells (MSCs) potentially improves clinical symptoms, but the underlying mechanism remains unclear. We conducted a randomized, single-blind, placebo-controlled (29 patients/group) phase II clinical trial to validate previous findings and explore the potential mechanisms. Patients treated with umbilical cord-derived MSCs exhibited a shorter hospital stay (P = 0.0198) and less time required for symptoms remission (P = 0.0194) than those who received placebo. Based on chest images, both severe and critical patients treated with MSCs showed improvement by day 7 (P = 0.0099) and day 21 (P = 0.0084). MSC-treated patients had fewer adverse events. MSC infusion reduced the levels of C-reactive protein, proinflammatory cytokines, and neutrophil extracellular traps (NETs) and promoted the maintenance of SARS-CoV-2-specific antibodies. To explore how MSCs modulate the immune system, we employed single-cell RNA sequencing analysis on peripheral blood. Our analysis identified a novel subpopulation of VNN2⁺ hematopoietic stem/progenitor-like (HSPC-like) cells expressing CSF3R and PTPRE that were mobilized following MSC infusion. Genes encoding chemotaxis factors - CX3CR1 and L-selectin - were upregulated in various immune cells. MSC treatment also regulated B cell subsets and increased the expression of costimulatory CD28 in T cells in vivo and in vitro. In addition, an in vivo mouse study confirmed that MSCs suppressed NET release and reduced venous thrombosis by upregulating kindlin-3 signaling. Together, our results underscore the role of MSCs in improving COVID-19 patient outcomes via maintenance of immune homeostasis.

FXII regulates the formation of deep vein thrombosis via the PI3K/AKT signaling pathway in mice

Deep vein thrombosis (DVT) is a common peripheral vascular disease, which may result in pulmonary embolism and is accompanied by endothelial injury. However, the pathogenesis of DVT remains unclear. Coagulation factor XII (FXII), as an important coagulation factor, has been reported to be closely associated with thrombosis. However, the association between FXII protein and DVT formation is not yet fully understood. The present study examined the effects of FXII protein on DVT formation and aimed to reveal the underlying mechanism. In the present study, histological characterization of the femoral vein tissue was examined by hematoxylin and eosin staining. The damage to the femoral vein tissue was examined by TUNEL assay. Superoxide dismutase (SOD) and malondialdehyde (MDA) concentrations were examined using ELISA. Tumor necrosis factor (TNF)‑α, interleukin (IL)‑6, IL‑8 and phosphoinositide 3‑kinase (PI3K)/AKT signaling were determined by ELISA, immunohistochemical staining and western blot analysis. The results demonstrated that thrombosis, FXII protein, cell apoptosis and the SOD concentrations were decreased, while the MDA concentrations were increased in mice with DVT compared with the control or sham groups. TNF‑α, IL‑6, IL‑8 and PI3K/AKT signaling was also upregulated in the mice with DVT. Furthermore, the knockdown of FXII significantly upregulated the SOD concentrations and downregulated thrombosis and cell apoptosis, as well as the MDA concentrations in mice with DVT. The knockdown of FXII also significantly downregulated the protein expression of TNF‑α, IL‑6 and IL‑8, and the activation of PI3K/AKT signaling. Additionally, LY294002 pre‑treatment markedly downregulated thrombosis and cell apoptosis and the MDA content, whereas it upregulated the SOD concentrations in mice with DVT. LY294002 pre‑treatment also significantly downregulated the TNF‑α, IL‑6 and IL‑8 protein levels. Taken together, the present study demonstrates that FXII protein promotes DVT via the activation of PI3K/AKT signaling by inducing an inflammatory response. Targeting FXII protein may thus prove to be a potential approach for the treatment of DVT.

Review: The Emerging Role of Neutrophil Extracellular Traps in Sepsis and Sepsis-Associated Thrombosis

Patients with sepsis commonly suffer from coagulation dysfunction and lead to the formation of thrombus. During the development of sepsis, neutrophils migrate from the circulating blood to infected tissues and mediate the formation of neutrophil extracellular traps (NETs) that kill pathogens. However, the overactivation of neutrophils can promote the formation of immunothrombosis and even cause disseminated intravascular coagulation (DIC), which damages microcirculation. The outcome of sepsis depends on early recognition and intervention, so clinical evaluation of NETs function may be a valuable biomarker for early diagnosis of sepsis. The interaction of NETs with platelets, complement, and endothelium mediates the formation of immunothrombosis in sepsis. Inhibiting the formation of NETs is also considered to be one of the potential treatments for sepsis. In this review, we will discuss the key role of neutrophils and NETs in sepsis and septic thrombosis, in order to reveal new mechanisms for thrombosis treatment of sepsis.