Interplay between inflammation and thrombosis in cardiovascular pathology

Update on the correlation between mitochondrial function and osteonecrosis of the femoral head osteocytes

Mitochondrial health is maintained in a steady state through mitochondrial dynamics and autophagy processes. Recent studies have identified healthy mitochondria as crucial regulators of cellular function and survival. This process involves adenosine triphosphate (ATP) synthesis by mitochondrial oxidative phosphorylation (OXPHOS), regulation of calcium metabolism and inflammatory responses, and intracellular oxidative stress management. In the skeletal system, they participate in the regulation of cellular behaviors and the responses of osteoblasts, osteoclasts, chondrocytes, and osteocytes to external stimuli. Indeed, mitochondrial damage or dysfunction occurs in the development of a few bone diseases. For example, mitochondrial damage may lead to an imbalance in osteoblasts and osteoclasts, resulting in osteoporosis, osteomalacia, or poor bone production, and chondrocyte death and inflammatory infiltration in osteoarthritis are the main causes of cartilage degeneration due to mitochondrial damage. However, the opposite exists for osteosarcoma, where overactive mitochondrial metabolism is able to accelerate the proliferation and migration of osteosarcoma cells, which is a major disease feature. Bone is a dynamic organ and osteocytes play a fundamental role in all regions of bone tissue and are involved in regulating bone integrity. This review examines the impact of mitochondrial physiological function on osteocyte health and summarizes the microscopic molecular mechanisms underlying its effects. It highlights that targeted therapies focusing on osteocyte mitochondria may be beneficial for osteocyte survival, providing a new insight for the diagnosis, prevention, and treatment of diseases associated with osteocyte death.

Rare case of left epididymo-orchitis complicated by pampiniform plexus thrombosis: A case report

Acute scrotal pain includes urgent conditions in urology, such as testicular torsion, testicular rupture, epididymo-orchitis, and abscess. However, varicocele (pampiniform plexus) thrombosis is considered to be a rare cause of such pain. We herein report a case of a 27-year-old male patient with a history of epididymo-orchitis, who complained of painful scrotal swelling. Ultrasonography showed left-side pampiniform plexus thrombosis. This case highlights a rare condition, which should be included in the differential diagnosis of acute scrotal pain, indicating the need for further studies to elucidate its pathophysiology and provide proper treatment for such cases.

Beyond the gut: Unraveling the multifaceted influence of microbiome on cardiovascular health

Cardiovascular disease is one of the leading causes of death worldwide. Even while receiving adequate pharmacological treatment for their hypertension, people are nonetheless at greater risk for cardiovascular disease. There is growing evidence that the gut microbiota may have major positive and negative effects on blood pressure and illnesses related with it as more study into this topic is conducted. Trimethylamine n-oxide (TMAO) and short-chain fatty acids (SCFA) are two major by-products of the gut microbiota. TMAO is involved in the formation of other coronary artery diseases, including atherosclerosis and hypertension, while SCFAs play an important role in controlling blood pressure. Numerous investigations have confirmed the established link between dietary salt intake and hypertension. Reducing sodium in the diet is linked to lower rates of cardiovascular disease morbidity and mortality as well as lower rates of blood pressure and hypertension. In both human and animal research, high salt diets increase local and systemic tissue inflammation and compromise gut architecture. Given that the gut microbiota constantly interacts with the immune system and is required for the correct maturation of immune cells, it is scientifically conceivable that it mediates the inflammatory response. This review highlights the therapeutic possibilities for focusing on intestinal microbiomes as well as the potential functions of the gut microbiota and its metabolites in the development of hypertension.

SARS-CoV-2 S1 protein induces IgG-mediated platelet activation and is prevented by 1.8-cineole

COVID-19 patients face an increased risk of thromboembolic complications, yet the exact pathophysiological role of platelets in the disease remains unclear. Considering the multifaceted nature of COVID-19 symptoms, including platelet hyperactivation and inflammation, the development of compounds that simultaneously target both represents a promising therapeutic strategy. The monoterpene 1.8-cineole (CNL-1976) is known for its anti-inflammatory and anti-aggregatory effects. Thus, understanding the mechanism behind platelet hyperactivation and the effect of 1.8-cineole during COVID-19 is crucial when aiming for a reduction of disease severity. In this study, we investigated the mechanism of platelet activation triggered by the SARS-CoV-2 S1 spike protein (S1). Utilizing S1-coupled beads, we discovered that platelet activation and aggregation were dependent on plasma components, particularly S1-specific IgG antibodies. The formation of immune complexes through IgG binding to S1 facilitated the crosslinking of the platelet expressed FcγRIIa receptor, initiating platelet activation and aggregation, as well as formation of platelet-leukocyte aggregates (PLAs). Importantly, treatment with 1.8-cineole significantly inhibited S1-bead-induced platelet activity and PLA formation. These findings strongly suggest that antibody-mediated platelet activation via FcγRIIa directly contributes to the well-recognized prothrombotic environment during COVID-19. Moreover, our data indicate that 1.8-cineole can serve as a potential therapeutic compound, alleviating platelet-driven thromboinflammatory complications associated with COVID-19 and post-acute sequelae of SARS-CoV-2 (PASC).

Formononetin attenuates myocardial ischemia/reperfusion injury by regulating neutrophil extracellular traps formation and platelet activation via platelet CD36

BACKGROUND

Prothrombotic and proinflammatory responses are crucial in the pathology of myocardial ischemia-reperfusion injury (MIRI). Platelets and neutrophil extracellular traps (NETs) are essential to linking inflammation with thrombosis. Formononetin (FMN), an isoflavone extracted from Astragalus membranaceus, has anti-inflammatory and anti-thrombotic effects and confers benefits on MIRI. However, the mechanisms of FMN against MIRI remain unclear.

PURPOSE

This study explored FMN's roles and mechanisms in modulating platelet activation and NETs formation to mitigate MIRI.

STUDY DESIGN AND METHODS

A rat model of MIRI by the left anterior descending coronary artery ligation was utilized to evaluate the role of FMN. 60 Sprague-Dawley male rats were randomly divided into 7 groups. Proteomics, flow cytometry, immunofluorescence, ELISA, and western blotting assays were performed to reveal the potential mechanisms of FMN. Neutrophils treated with platelet-rich plasma were applied to further explore the mechanisms of FMN in vitro.

RESULTS

We showed that FMN administration declined myocardial infarct size and improved cardiac function. Moreover, FMN significantly reduced MIRI-induced platelet activation including platelet aggregation, platelet adhesion, platelet granule secretion, and platelet-leukocyte aggregation without affecting tail bleeding time. Additionally, FMN inhibited microthrombus, platelet-neutrophil aggregation, and NETs formation in myocardial tissue. Mechanistically, FMN attenuated MIRI-induced CD36 expression and phosphorylation of ERK5 in platelets. Furthermore, up-regulation of CD36 content in vitro counteracted the potency of FMN to inhibit platelet activation and NETs formation.

CONCLUSION

FMN mitigates thrombosis and inflammation in MIRI by inhibiting platelet activation and NETs formation via the CD36 pathway. This research offers important insights for future studies on MIRI prevention.

2-Methoxybenzoic acid ameliorates arterial thrombosis via inhibiting carbon anhydrase activity in platelet

BACKGROUND

2-Methoxybenzoic acid (2MOA) is a natural compound with potential salicylate-like effects; however, its impact on arterial thrombosis remains unclear.

OBJECTIVES

This study aimed to investigate the effects of 2MOA on thrombogenesis and its underlying mechanisms.

METHODS

FeCl3-induced carotid artery injury and laser-induced cremaster artery injury thrombosis assays were used to explore the effect of 2MOA on thrombogenesis in vivo. Various ex vivo platelet function assays were conducted to evaluate the impacts of 2MOA on platelet activity. In addition, untargeted metabolomics analysis was performed to identify the alterations in intraplatelet metabolites following 2MOA treatment.

RESULTS

We found that 2MOA significantly ameliorated thrombosis in a dose-dependent manner, without affecting the normal hemostasis in C57BL/6J mice. 2MOA suppressed platelet reactivity as indicated by decreased spreading, retraction, and aggregation in both mouse and human platelets. Metabolomics analysis revealed significantly alterations in purine metabolism following 2MOA treatment, which increased cyclic guanosine monophosphate production in platelets. Mechanistically, 2MOA inhibited the activity of carbonic anhydrase, leading to elevated intraplatelet cGMP level, and subsequent suppression of cytosolic phospholipase A2 phosphorylation.

CONCLUSION

Our study illustrates that 2MOA efficaciously inhibits platelet reactivity and alleviates thrombogenesis via suppressing carbonic anhydrase activity, which should be a promising reagent in the prevention and treatment of arterial thrombotic events.

Microenvironment-responsive coating for vascular stents to regulate coagulation-inflammation interaction and promote vascular recovery

Early coagulation-inflammation interaction and late in-stent restenosis undermine the efficacy of vascular stents after implantation. Targeting the interplay between inflammation and coagulation, and smooth muscle cell (SMC) proliferation, we presented a microenvironment-responsive coating designed to regulate tissue responses and vascular regeneration throughout the remodeling process. Coagulation was inhibited by incorporating anticoagulant tirofiban into the coating. MMP9-responsive nanoparticles embedded in the coating released salvianolic acid A to modulate inflammatory cell behavior and inhibit SMC dysfunction. By effectively interfering with clotting and inflammation, the coating suppressed platelet-fibrin interaction and formation of platelet-monocyte aggregates, thereby mitigating adverse effects on reendothelialization. Its ability to influence SMC proliferation and migration resulted in reduced intimal hyperplasia. Coated stents were shown to significantly regulate tissue regeneration, improve the vascular environment and even reduced the lipid content in the narrowed atherosclerotic vessels in vivo. This direct approach enhanced the vascular tissue regeneration after stent implantation, and offered promising insights for optimizing vascular stent design.

Perioperative Hyper-coagulation and Thrombosis: Cost Analysis After Congenital Heart Surgery

Thrombosis, a major adverse event of congenital heart surgery, has been associated with poor outcomes. We hypothesized that in CHD patients undergoing cardiac surgery, increased perioperative use of pro-coagulant products may be associated with postoperative thrombosis in the setting of hyperfibrinogenemia, leading to greater hospital and blood product costs. Single-center retrospective study. Data from Boston Children's Hospital's electronic health record database was used in this study. All patients undergoing congenital heart surgery between 2015 and 2018 with postoperative fibrinogen levels above 400 mg/dl were reviewed. Of 334 patients with high plasma fibrinogen levels, 28 (8.4%) developed postoperative thrombosis (median age: one year, 59% male). In our cohort, 25 (7%) demonstrated evidence of baseline hypercoagulability by one or more panel test results. Thrombosis was associated with greater hospital and blood product costs, longer ventilation times, and longer hospital and ICU length of stays. Preoperative hypercoagulable state (odds ratio: 2.58, 95% CI [1.07, 9.99], p = 0.002), postoperative red blood cell transfusion (odds ratio: 1.007, 95% CI [1.000, 1.015], p = 0.04), and single ventricle physiology (univariate odds ratio: 2.94, 95% CI [1.09, 7.89], p = 0.03) were predictors of postoperative thrombosis. Preoperative hypercoagulable state and intraoperative platelet transfusion were predictors of hospital cost. Thrombosis was associated with worse in-hospital outcomes and higher costs. Preoperative hypercoagulable state and postoperative red blood cell transfusion were significant predictors of thrombosis. Risk prediction models that can guide thrombosis prevention are needed to improve outcomes of patients undergoing congenital heart surgery.

Platelet-activating cytokines potentially associated with MASLD-induced liver injury significantly decreased following CPAP therapy: A translational study using a fatty liver mouse model

BACKGROUND AND AIM

Patients with obstructive sleep apnea (OSA) and metabolic dysfunction associated steatotic liver disease (MASLD) frequently overlap due to the high prevalence of obesity. This translational study aimed to identify cytokines linking these conditions, beginning with an analysis of fatty liver in mice. Serum cytokine levels upregulated in the fatty liver mice were subsequently examined in human OSA serum samples.

METHODS

Mice were fed a high-fat diet to induce fatty liver. Liver proteins were analyzed using cytokine arrays. Serum samples from seventy (70) OSA patients (with 20 non-MASLD and 50 MASLD, pre- and 6-month post-continuous positive airway pressure [CPAP] therapy) were analyzed for the cytokines identified in the mouse experiment using enzyme-linked immunosorbent assays.

RESULTS

Four platelet-activation chemokines/cytokines (CCL5/RANTES, P-selectin, CXCL4/PF4, and CXCL5/LIX) were upregulated in mice with fatty liver. While serum levels of these factors were not significantly higher in MASLD-OSA compared to non-MASLD-OSA patients, their levels significantly decreased 6 months after the initiation of CPAP therapy, along with a reduction in mean platelet volume. CPAP compliance was significantly associated with a reduction in CCL5 levels. Additionally, a decrease in ALT levels following 6 months of CPAP therapy was significantly associated with CPAP compliance in MASLD-OSA patients.

CONCLUSIONS

While platelet-activation cytokines were not directly implicated in liver injury in MASLD-OSA patients, they decreased with CPAP therapy. CPAP compliance may play a key role in ALT reduction in MASLD-OSA patients independently of body weight changes. CCL5/RANTES may be indirectly associated with liver injury in MASLD-OSA, potentially induced through intermittent hypoxia.

The critical role of platelets in venous thromboembolism: Pathogenesis, clinical status, and emerging therapeutic strategies

Venous thromboembolism (VTE), encompassing deep vein thrombosis (DVT) and pulmonary embolism (PE), is a complex vascular disorder with high morbidity and mortality, driven by Virchow's Triad: blood stasis, hypercoagulability, and endothelial injury. VTE is now recognized as an inflammatory process involving multiple components. Platelets are involved in the process of VTE, contributing to thrombosis initiation, progression, resolution and recurrence through coagulation activation, and interactions with immune and endothelial cells. Anticoagulation remains the cornerstone of VTE treatment; however, antiplatelet agents like aspirin have demonstrated therapeutic potential, particularly following major orthopedic surgeries. Furthermore, emerging platelet-targeted therapies and biomarkers offer new opportunities for improving VTE diagnosis and treatment. This review explores the evolving role of platelets in VTE pathophysiology, assesses current antiplatelet strategies, and highlights novel therapeutic approaches. Advancing platelet research in VTE may lead to safer, more effective interventions, optimizing outcomes for patients with this life-threatening condition.

Platelets in vascular inflammation: fire-fighters or pyromaniacs?

PURPOSE OF REVIEW

In this review, we aim to highlight recent insights into the mechanisms through which platelets contribute to vascular inflammation. We will discuss how platelets interact with other cellular players in the vascular milieu, their role in shaping inflammatory responses, and the potential therapeutic implications of targeting platelet function in inflammatory vascular diseases.

RECENT FINDINGS

Platelets are essential components in the processes of hemostasis and thrombosis. Their role is now widely acknowledged as far more complex than merely acting as "band-aids" or helping to "clog a pipe". Platelets are now recognized as crucial mediators in inflammatory reactions, particularly in various diseases of the vasculature, where they contribute to the onset and progression of injury. Through their interactions with leukocytes, vascular cells, and by supporting the coagulation cascade, platelets are able to finely regulate the extent and intensity of vascular damage.

SUMMARY

Recent findings underscore the remarkable diversity and functionality of platelets in vascular diseases. Mechanistic studies in preclinical models reveal promising therapeutic opportunities, which require further validation before being translated into clinical practice.

Association of coagulation-related indicators with postoperative venous thromboembolism occurrence in patients with pituitary tumors

This study aimed to analyze risk factors for postoperative VTE in pituitary tumor resection patients, focusing on coagulation indicators and their predictive value. This study collected clinical data from 300 patients who underwent pituitary adenoma resection from January 2021 to August 2023 in the Department of Neurosurgery, the Second Clinical College of the Army Medical University, China. Logistic regression modeling was used to identify risk factors for VTE. Restricted cubic spline curves were used to characterize the dose-response relationship between coagulation-related indicators and the risk of venous thromboembolism. The area under the curve (AUC) was calculated using the receiver operating characteristic (ROC) curve to evaluate the predictive power of coagulation-related indicators. Multivariate analysis showed that D-dimer, platelet count and hemoglobin (Hb) were significant predictors of VTE with OR (95% CI) of 1.967 (1.441-2.808), 1.020 (1.013-1.029), and 0.952 (0.914-0.994), respectively. The AUCs for D-dimer, Platelet Count, and Hb were 0.708, 0.731, and 0.712, respectively. The AUC for combining the three coagulation indices was the largest, 0.838. The combined use of D-dimer, Hb, and platelet count can identify high-risk patients early, enabling timely implementation of antithrombotic strategies.

Micro/nanomotors for active inflammatory disease therapy

Inflammation is a carefully orchestrated response of the immune system to repair injured tissues and clear various damage factors. However, dysregulated inflammation can eventually contribute to the development and progression of various inflammatory diseases. Although anti-inflammatory drugs have demonstrated certain therapeutic efficacy in clinical settings, significant limitations still persist, highlighting the necessity for the development of improved approaches to address complex inflammatory conditions. Micro/nanomotors (MNMs) have shown significant promise for applications in the biomedical field due to their micro/nano-scale sizes and autonomous movement. Unlike traditional nanoparticles, which exhibit passive diffusion in biological fluids, MNMs can convert external energy into a driving force for self-propulsion. This capability not only enhances the tissue penetration depth and retention rates but also facilitates interaction with inflammatory lesions. Recent efforts have suggested that MNMs for inflammatory disease therapy could provide an efficient therapeutic effect. Herein, we mainly introduce the recent advances in inflammatory disease therapy based on MNMs. We conclude by discussing both the obstacles and potential opportunities for MNMs innovations in addressing inflammation.

Immunothrombolytic monocyte-neutrophil axes dominate the single-cell landscape of human thrombosis and correlate with thrombus resolution

Thrombotic diseases remain the major cause of death and disability worldwide, and the contribution of inflammation is increasingly recognized. Thromboinflammation has been identified as a key pathomechanism, but an unsupervised map of immune-cell states, trajectories, and intercommunication at a single-cell level has been lacking. Here, we reveal innate leukocyte substates with prominent thrombolytic properties by employing single-cell omics measures on human stroke thrombi. Using in vivo and in vitro thrombosis models, we propose a pro-resolving monocyte-neutrophil axis, combining two properties: (1) NR4A1hi non-classical monocytes acquire a thrombolytic and neutrophil-chemoattractive phenotype, and (2) blood neutrophils are thereby continuously recruited to established thrombi through CXCL8-CXCR1 and CXCR2 and adopt a hypoxia-induced thrombus-resolving urokinase receptor (PLAUR)+ phenotype. This immunothrombolytic axis results in thrombus resolution. Together, with this immune landscape of thrombosis, we provide a valuable resource and introduce the concept of "immunothrombolysis" with broad mechanistic and translational implications at the crossroad of inflammation and thrombosis.

Arterial and venous thrombosis in systemic and monogenic vasculitis

Systemic vasculitis, common forms of which include anti-neutrophil cytoplasmic antibody-associated small-vessel vasculitis, large-vessel vasculitis and Behçet syndrome, are frequently complicated by arterial or venous thrombotic events (AVTEs). Newly identified entities such as DADA2 (deficiency of adenosine deaminase 2) and VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome, which are driven by genetic mutations, also exhibit vasculitic features and are associated with a high risk of AVTEs. AVTEs in systemic vasculitis, including monogenic forms of vasculitis, are due to the complex interaction of inflammation and coagulation. New insights into the pathogenetic mechanisms implicate endothelial dysfunction, immune complex deposition and the interplay of pro-inflammatory cytokines with prothrombotic factors, which collectively promote thrombus formation. AVTEs impose a substantial disease burden, complicate diagnosis and negatively affect prognosis by increasing the risk of morbidity and mortality. Early diagnosis and treatment are crucial to prevent lasting damage. Management strategies should target both thrombosis and underlying inflammation. Antithrombotic therapies, including low-dose aspirin, or oral anticoagulants should be used on the basis of individual thrombotic risk assessment. Immunosuppressive therapy is the cornerstone of treatment for arterial and venous thrombosis, particularly in Behçet syndrome, in which vascular inflammation has a crucial role in thrombotic complications.

In situ protein corona-camouflaged supramolecular assemblies remodel thrombotic microenvironment for improved arterial homeostasis

Arterial thrombosis is commonly accompanied by poor recanalization and high recurrence, typically caused by a fibrinolysis-resistant microenvironment. We identify elevated levels of plasminogen activator inhibitor-1 (PAI-1) and, notably, its strong correlation with inflammation in arterial thrombosis. To address this, small molecular inhibitors of PAI-1 and inflammation are used as bioregulators to restore vascular homeostasis. We design a carrier-free supramolecular system based on the bioregulators-tuned self-assembly of a near-infrared thrombus probe, which preferentially forms protein corona in situ to enhance plasma stability. Under acidic conditions and increased shear stress, the supramolecular assemblies disintegrate, enabling site-specific cargo release. In vivo, the probe accumulates 22.8-fold more in the thrombotic than contralateral artery. Functionally, this nanomedicine improves outcomes in mice with carotid artery thrombosis and chronic cerebral ischemia. Mechanistically, it down-regulates NF-κB signaling, inhibits NETosis and glycolysis, and up-regulates cGMP-mediated signaling, thereby alleviating inflammation and promoting fibrinolysis. This study offers an innovative codelivery strategy using supramolecular assemblies to advance therapies for arterial thrombosis.

Recent Advances in Immunothrombosis and Thromboinflammation

Inflammation and thrombosis are traditionally considered two separate entities of acute host responses to barrier breaks. While inciting inflammatory responses is a prerequisite to fighting invading pathogens and subsequent restoration of tissue homeostasis, thrombus formation is a crucial step of the hemostatic response to prevent blood loss following vascular injury. Though originally designed to protect the host, excessive induction of either inflammatory signaling or thrombus formation and their reciprocal activation contribute to a plethora of disorders, including cardiovascular, autoimmune, and malignant diseases. In this state-of-the-art review, we summarize recent insights into the intricate interplay of inflammation and thrombosis. We focus on the protective aspects of immunothrombosis as well as evidence of detrimental sequelae of thromboinflammation, specifically regarding recent studies that elucidate its pathophysiology beyond coronavirus disease 2019 (COVID-19). We introduce recently identified molecular aspects of key cellular players like neutrophils, monocytes, and platelets that contribute to both immunothrombosis and thromboinflammation. Further, we describe the underlying mechanisms of activation involving circulating plasma proteins and immune complexes. We then illustrate how these factors skew the inflammatory state toward detrimental thromboinflammation across cardiovascular as well as septic and autoimmune inflammatory diseases. Finally, we discuss how the advent of new technologies and the integration with clinical data have been used to investigate the mechanisms and signaling cascades underlying immunothrombosis and thromboinflammation. This review highlights open questions that will need to be addressed by the field to translate our mechanistic understanding into clinically meaningful therapeutic targeting.

Immune cells and arrhythmias

Cardiac arrhythmias are a significant cause of morbidity and mortality worldwide. Emerging evidence has demonstrated that resident and infiltrating cardiac immune cells play direct, mechanistic roles in arrhythmia onset and progression. In this review, we provide a comprehensive summary and expert commentary on the role of each immune cell subtype in the pathogenesis of atrial and ventricular arrhythmias.

Platelet spleen tyrosine kinase is a key regulator of anti-PF4 antibody-induced immunothrombosis

ABSTRACT

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare but serious prothrombotic adverse event after vaccination with adenovector-based COVID-19 vaccines. Laboratory findings indicate that anti-platelet factor 4 (PF4) immunoglobulin G antibodies are the causing factor for the onset of thromboembolic events in VITT. However, molecular mechanisms of cellular interactions, signaling pathways and involvement of different cell types in VITT antibody-mediated thrombosis are not fully understood. Moreover, uncertainty exists regarding current treatment protocols because the sole anticoagulation was shown to be inefficient to prevent thrombosis progression in severe VITT cases. In this study, we demonstrate that platelet spleen tyrosine kinase (SYK) modulates anti-PF4 VITT-mediated thrombus formation in an ex vivo model of immunothrombosis. Our study showed that the selective inhibition of SYK can abrogate VITT antibody-driven procoagulant platelet formation, activation of plasmatic coagulation as well as platelet-leukocyte interplay. Most importantly, the specific inhibition of SYK in platelets but not in neutrophils prevented VITT antibody-induced multicellular thrombus formation, without perturbing the platelet function. Our findings indicate that the specific targeting of platelet SYK might be a promising therapeutic approach to prevent thrombotic complications in patients with antibody-mediated immunothrombosis.

Biosynthesis of a N-Acetylated Tricyclic Carbazole with Antithrombotic Activity

Tricyclic carbazoles are significant pharmacophores. Herein, heterologous expression of the carbazole-3,4-quinone (1) biosynthetic pathway in the chassis host Streptomyces albus J1074 yielded a previously chemosynthesized orthoquinone carbazole (2) and three new N-acetylated carbazoles (3-5). Their structures were established by a combination of HR-ESI-MS, NMR, and X-ray crystallographic analysis. Compound 2, the deaminated precursor of 4 and 5, was enzymatically synthesized, indicating the substrate tolerance of the key enzymes in the bacterial tricyclic-carbazole biosynthetic pathway. Mutagenetic analysis revealed an arylamine N-acetyltransferase homologous gene required for the production of compounds 3-5. Bioactivity analysis using the zebrafish model demonstrated that compound 5 has significant antithrombotic activity, potentially by downregulating the genes involved in the platelet activation and coagulation cascade. These findings expand the natural strategies for structural diversification of the tricyclic carbazole alkaloids.

Management of vision loss associated with complications of cosmetic filler injections

Injectable cosmetic fillers have dramatically risen in popularity in recent years. However, as the use of such fillers has become more common, there have been many reports of vision loss secondary to misplaced filler embolizing to the ophthalmic artery resulting in ocular ischemia. Currently, there are no randomized control trials or widely validated clinical guidelines that dictate how injectors should manage ischemic complications of filler embolism. This review aims to explain the possible mechanisms by which a cosmetic filler embolus can occlude the ophthalmic artery, describe the types of treatments that have been attempted thus far, and delineate possible a stroke-like protocol that can be implemented in order to restore perfusion and recover vision after such ischemic complications have occurred.

Okra polysaccharide mitigates carrageenan-induced thrombosis in mice by regulating inflammation and oxidative stress

Introduction

Thrombosis is a serious health hazard, which has been paid more and more attention.Okra polysaccharide (OP) is a biologically active substance extracted from okra which exhibits anti-inflammation and anti-oxidative properties. Nevertheless, the effect of OP on thrombosis is still unknown. In this study, we determined whether OP can suppress carrageenan-induced mice thrombosis and its involved mechanism.

Methods

Twenty-four BALB/c mice were assigned to four groups randomly (6 mice/group): Ctrl, Model, OP low lose (OP-L, 200 mg/kg body weight), and OP high lose (OP-H,400 mg/kg body weight) were administered via intragastric administration for 9 days. Tails were photographed before collecting for H&E and Masson staining. Liver and lung tissues were collected for H&E staining, RT-qPCR, Western blot and GSH content detection. Injury or dysfunction of endothelial cells (ECs) was assessed using RT-qPCR, Western blot and cell adhesion assays.

Results

OP can effectively improve carrageenan-induced thrombosis in tissues of mice (tail, liver, and lung) in vivo. In addition, OP inhibited inflammation by suppressing the toll-like receptor 4 (TLR4)/nuclear factor κB (NF-κB) pathway and reduced oxidative damage by elevating the level of GSH and antioxidant enzyme in liver and lung tissues. In vitro, OP inhibited thrombin-induced human platelet clots retraction, and decreased lipopolysaccharide (LPS)-activated adhesion of THP-1 monocytes to human umbilical vein endothelial cells(HUVECs) by suppressing intercellular adhesion molecule-1 (ICAM-1) level.

Discussion

In conclusion, OP can inhibit thrombosis in mouse model by regulating inflammation and oxidative stress, which suggest that OP could act as a potential functional food for prevention of thrombus.

Establishing a prediction model for lower extremity deep venous thrombosis in emergency inpatients in the post epidemic era

Objective

This study aimed to analyze the risk factors of lower extremity deep vein thrombosis (LEDVT) in emergency inpatients in the post-epidemic era, and to establish a prediction model for identifying high-risk patients of LEDVT.

Methods

Emergency inpatients admitted to our hospital from June 2022 to June 2023 were divided into two groups: the epidemic group and the post-epidemic group. The baseline characteristics, blood routine, liver and kidney function, blood coagulation function, and LE ultrasonography were compared between the two groups. Multivariate logistic analysis and receiver operating character (ROC) curve were used to establish and evaluate the effectiveness of a prediction model for LEDVT in the post-epidemic era.

Results

A total of 967 patients were analyzed, including 388 cases in the epidemic group and 579 cases in the post-epidemic group. The portion of LEDVT cases in the post-epidemic group (33.2%) was significantly higher than that in the epidemic group (26.8%, P = 0.036). Binary Logistic regression analysis showed that age, smoking history, drinking history and glycosylated hemoglobin (HBA1c) were independent risk factors for thrombosis. The prediction model was established as P = 0.863 × age + 0.978 × smoking history + 0.702 × drinking history + 0.104 × HBA1c - 2.439. The area under the ROC curve was 0.718.

Conclusion

The incidence of LEDVT in emergency inpatients in the post-epidemic era was significantly higher than that in the epidemic period. Age, smoking and drinking history, and glycosylated hemoglobin are at high risk for thrombosis.

Proteomic evaluation of the thrombosis-inflammation interplay in STEMI with MVO

BACKGROUND

Coronary microvascular obstruction (MVO) occurs in up to half of acute myocardial infarction patients receiving successful primary percutaneous coronary intervention (pPCI) and is associated with a much worse outcome. Whereas the fluid phase cross-talk between thrombosis and inflammation is well appreciated, the pathophysiological implication is still scant.

OBJECTIVES

This study sought to investigate the differentially expressed proteins and possible biological processes involved in MVO after pPCI in ST-segment elevation myocardial infarction (STEMI) patients based on thrombus proteomics.

METHODS

Aspirated thrombi and pPCI from 16 STEMI patients within 12 h of symptom onset were collected, including 8 MI with MVO (MVO+) and 8 MI without MVO (MVO-). 4D label-free proteomics was used to explore the differentially expressed proteins. Gene ontology enrichment analysis was performed using Metascape software and protein‒protein interaction analysis was performed using Cystoscope software. Afterward, the Connectivity Map database was used to select drug candidates for MVO treatment.

RESULTS

We identified a total of 471 proteins with expression changes greater than 1.5-fold at P < 0.05, of which 50 were significantly upregulated and 421 were downregulated in the MVO + group compared with the MVO- group. Gene ontology enrichment analysis of significant differentially expressed proteins revealed the central role of platelet activation and neutrophil degranulation processes in patients with MVO. The protein-protein interaction network also confirmed the significant interaction of inflammation and platelet activation, which may mediate the role of thrombus-inflammation in the pathogenesis of MVO. Drug screening revealed 4 drug candidates for MVO treatment: D-64,131, TC-1, SB-431,542 and alvespimycin.

CONCLUSIONS

Using the thrombus proteomic approach, we revealed the central role of the thrombus-inflammation interaction and potential drug candidates in STEMI with MVO. The findings from our study will contribute to the treatment of MVO in the future.

A mendelian randomization study on the association between 731 types of immune cells and 91 types of blood cells with venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is a grave medical condition characterized by the blockage of distant blood vessels due to blood clots or detached vessel wall fragments, leading to ischemia or necrosis of the affected tissues. With the recent introduction of immunothrombosis, the significance of immune cells in the process of thrombus formation has gained prominent attention. Complex cross-talk occurs between immune cells and blood cells during infection or inflammation, with immune cells actively participating in blood clot formation by promoting platelet recruitment and thrombin activation. Nevertheless, comprehensive studies on the genetic association between immune cells phenotypes and VTE remain scarce. This article employed Mendelian randomization (MR) to investigate the association between the incidence of VTE and a range of 731 immune cell types, along with 91 blood cell perturbation phenotypes, utilizing single nucleotide polymorphisms as instrumental variables.

METHODS

Through the utilization of publicly available genetic data, a two-sample bi-directional MR analysis was conducted. Sensitivity analyses included Cochran's Q test, MR-Egger intercept test, MR-pleiotropy residual sum and outlier (MR-PRESSO) and leave-one-out analysis. For significant associations, replication analysis was conducted using GWAS data from deep vein thrombosis (DVT) and pulmonary embolism (PE).

RESULTS

We firstly investigated the causal relationship between 731 immune cells and VTE risk. All the GWAS data were obtained from European populations and from men and women. The IVW analysis revealed that CD20 on naive-mature B cell, CD20 on IgD- CD38dim B cell, and CD20 on unswitched memory B cell may increase the risk of VTE (P < 0.05). CD28- CD8dim T cell %T cell, CD64 on monocyte and CD64 on CD14 + CD16- monocyte may be protective factors against DVT (P < 0.05). Then disturbed blood cells types as exposure were analyzed to examine its association with occurrence of VTE. Initial and replication analysis both revealed that environmental KCl-impacted red blood cells and butyric acid-impacted platelet accelerated incidence of VTE (P < 0.05), while colchicine -impacted eosinophil, KCl-impacted reticulocyte and Lipopolysaccharide (LPS) -impacted neutrophil reduced VTE risk (P < 0.05). Sensitivity analyses confirmed the robustness and reliability of these positive findings.

CONCLUSIONS

Our study presents evidence of a causal link between six immune cell phenotypes and VTE. Additionally, we have identified two types of blood cells that are associated with both VTE and DVT, and three types of blood cells that are relevant to both VTE and PE.

CLINICAL TRIAL NUMBER

Not applicable.

Aging platelets shift their hemostatic properties to inflammatory functions

ABSTRACT

Platelets are crucial players in hemostasis and thrombosis but also contribute to immune regulation and host defense, using different receptors, signaling pathways, and effector functions, respectively. Whether distinct subsets of platelets specialize in these diverse tasks is insufficiently understood. Here, we used a pulse-labeling method in Mus musculus models for tracking in vivo platelet aging and its functional implications. Using in vitro and in vivo assays, we reveal that young, reticulated platelets show heightened responses in the setting of clot formation, with corresponding, increased responses to agonists, adhesion, and retractile function. Unexpectedly, aged platelets lose their hemostatic proficiency but are more prone to react to inflammatory challenge: compared with reticulated platelets, this cohort was more likely to form platelet-leukocyte aggregates and showed increased adhesion to neutrophils in vitro, as well as enhanced bactericidal function. In vivo, this was reflected in increased pulmonary recruitment of aged platelets in an acute lung injury model. Proteomic analyses confirmed the upregulation of immune pathways in this cohort, including enhanced procoagulant function. In mouse models of prolonged platelet half-life, this resulted in increased pulmonary leukocyte infiltration and inflammation upon acute lung injury. Similarly, human platelet concentrates decreased their hemostatic function and elevated their putative immunomodulatory potential in vitro over time, and in a mouse model of platelet transfusion, aged platelet concentrates resulted in augmented inflammation. In summary, we show that platelets exhibit age-dependent phenotypic shifts, allowing them to fulfill their diverse tasks in the vasculature. Because functional alterations of aging platelets extend to platelet concentrates, this may hold important implications for transfusion medicine.

Stroke Prognosis: The Impact of Combined Thrombotic, Lipid, and Inflammatory Markers

AIM

D-dimer, lipoprotein (a) (Lp(a)), and high-sensitivity C-reactive protein (hs-CRP) are known predictors of vascular events; however, their impact on the stroke prognosis is unclear. This study used data from the Third China National Stroke Registry (CNSR-III) to assess their combined effect on functional disability and mortality after acute ischemic stroke (AIS).

METHODS

In total, 9,450 adult patients with AIS were enrolled between August 2015 and March 2018. Patients were categorized based on a cutoff value for D-dimer, Lp(a), and hs-CRP in the plasma. Adverse outcomes included poor functional outcomes (modified Rankin Scale (mRS score ≥ 3)) and one- year all-cause mortality. Logistic and multivariate Cox regression analyses were performed to investigate the relationship between individual and combined biomarkers and adverse outcomes.

RESULTS

Patients with elevated levels of all three biomarkers had the highest odds of functional disability (OR adjusted: 2.01; 95% CI (1.47-2.74); P＜0.001) and mortality (HR adjusted: 2.93; 95% CI (1.55-5.33); P＜0.001). The combined biomarkers improved the predictive accuracy for disability (C-statistic 0.80 vs.0.79, P＜0.001) and mortality (C-statistic 0.79 vs.0.78, P=0.01).

CONCLUSION

Elevated D-dimer, Lp(a), and hs-CRP levels together increase the risk of functional disability and mortality one-year post-AIS more than any single biomarker.

Checkpoint Inhibitors, CAR T Cells, and the Hemostatic System: What Do We Know So Far?

Immune checkpoint inhibitors (ICIs) and chimeric antigen receptor (CAR) T cells are novel therapeutic strategies that enhance anticancer immunity by activating or engineering cancer-targeting T cells. The resulting hyperinflammation carries several side effects, ranging from autoimmune-like symptoms to cytokine release syndrome (CRS), with potentially severe consequences. Recent findings indicate that ICIs increase the risk of venous and arterial thromboembolic adverse events. Patients with prior VTE might be at higher risk of developing new events under ICI while other risk factors vary across studies. So far, data on CAR T-linked coagulopathies are limited. Hypofibrinogenemia in the presence of CRS is the most commonly observed dysregulation of hemostatic parameters. A rare but particularly severe adverse event is the development of disseminated intravascular coagulation activation, which can occur in the setting of CRS and may be linked to immune effector cell-associated hemophagocytic lymphohistiocytosis. While the increasing number of studies on thromboembolic complications and coagulation alterations under ICIs and CAR T therapies are concerning, these results might be influenced by the retrospective study design and the heterogeneous patient populations. Importantly, numerous promising new T cell-based immunotherapies are currently under investigation for various cancers and are expected to become very prominent therapy options in the near future. Therefore, coagulopathies and thrombosis under T cell-directed immuno- and anti-cancer therapies is important. Our review provides an overview of the current understanding of ICI- and CAR T-associated thromboembolism. We discuss pathogenic mechanisms of inflammation-associated coagulation activation and explore potential biomarkers for VTE.

Mice with reduced protease-activated receptor 4 reactivity show decreased venous thrombosis and platelet procoagulant activity

BACKGROUND

Hypercoagulation and thrombin generation are major risk factors for venous thrombosis. Sustained thrombin signaling through protease-activated receptor (PAR) 4 promotes platelet activation, phosphatidylserine exposure, and subsequent thrombin generation. A single nucleotide polymorphism in PAR4 (rs2227376) changes proline to leucine extracellular loop 3, which decreases PAR4 reactivity and is associated with a lower risk for venous thromboembolism (VTE) in a genome wide association studies meta-analysis.

OBJECTIVES

The goal of this study was to determine the mechanism for the association of rs2227376 with a reduced risk of VTE using mice with a homologous mutation (PAR4-P322L).

METHODS

Venous thrombosis was examined using our recently generated PAR4-P322L mice in the inferior vena cava stasis and stenosis models. Coagulation and clot stability were measured using rotational thromboelastometry. Thrombin-generating potential was measured in platelet-rich plasma. Phosphatidylserine surface expression and platelet-neutrophil aggregates were analyzed using flow cytometry.

RESULTS

Mice heterozygous (PAR4P/L) or homozygous (PAR4L/L) at position 310 had reduced sizes of venous clots at 48 hours. PAR4P/L and PAR4L/L platelets had progressively decreased phosphatidylserine in response to thrombin and convulxin, in addition to decreased thrombin generation and decreased PAR4-mediated platelet-neutrophil aggregation.

CONCLUSION

The leucine allele in extracellular loop 3, PAR4-322L, leads to fewer procoagulant platelets, decreased endogenous thrombin potential, and reduced platelet-neutrophil aggregation. This decreased ability to generate thrombin and bind to neutrophils offers a mechanism for PAR4's role in VTE, highlighting a key role for PAR4 signaling.

Role of Thrombosis in Neurodegenerative Diseases: An Intricate Mechanism of Neurovascular Complications

Thrombosis, the formation of blood clots in arteries or veins, poses a significant health risk by disrupting the blood flow. It can potentially lead to major cardiovascular complications such as acute myocardial infarction or ischemic stroke (arterial thrombosis) and deep vein thrombosis or pulmonary embolism (venous thrombosis). Nevertheless, over the course of several decades, researchers have observed an association between different cardiovascular events and neurodegenerative diseases, which progressively harm and impair parts of the nervous system, particularly the brain. Furthermore, thrombotic complications have been identified in numerous clinical instances of neurodegenerative diseases, particularly Alzheimer's disease, Parkinson's disease, multiple sclerosis, and Huntington's disease. Substantial research indicates that endothelial dysfunction, vascular inflammation, coagulation abnormalities, and platelet hyperactivation are commonly observed in these conditions, collectively contributing to an increased risk of thrombosis. Thrombosis can, in turn, contribute to the onset, pathogenesis, and severity of these neurological disorders. Hence, this concise review comprehensively explores the correlation between cardiovascular diseases and neurodegenerative diseases, elucidating the cellular and molecular mechanisms of thrombosis in these neurodegenerative diseases. Additionally, a detailed discussion is provided on the commonly employed antithrombotic medications in the context of these neuronal diseases.

The concept of immunothrombosis in pancreas transplantation

Early failure of a pancreatic allograft due to complete thrombosis has an incidence of approximately 10% and is the main cause of comorbidity in pancreas transplantation. Although several risk factors have been identified, the exact mechanisms leading to this serious complication are still unclear. In this review, we define the roles of the individual components involved during sterile immunothrombosis-namely endothelial cells, platelets, and innate immune cells. Further, we review the published evidence linking the main risk factors for pancreatic thrombosis to cellular activation and vascular modifications. We also explore the unique features of the pancreas itself: the vessel endothelium, specific vascularization, and relationship to other organs-notably the spleen and adipose tissue. Finally, we summarize the therapeutic possibilities for the prevention of pancreatic thrombosis depending on the different mechanisms such as anticoagulation, anti-inflammatory molecules, endothelium protectors, antagonism of damage-associated molecular patterns, and use of machine perfusion.

Injection of ROS-Responsive Hydrogel Loaded with IL-1β-targeted nanobody for ameliorating myocardial infarction

The cardiac microenvironment profoundly restricts the efficacy of myocardial regeneration tactics for the treatment of myocardial infarction (MI). A prospective approach for MI therapeutics encompasses the combined strategy of scavenging reactive oxygen species (ROS) to alleviate oxidative stress injury and facilitating macrophage polarization towards the regenerative M2 phenotype. In this investigation, we fabricated a ROS-sensitive hydrogel engineered to deliver our previously engineered IL-1β-VHH for myocardial restoration. In mouse and rat models of myocardial infarction, the therapeutic gel was injected into the pericardial cavity, effectively disseminated over the heart surface, forming an in situ epicardial patch. The IL-1β-VHH released from the hydrogel exhibited penetrative potential into the myocardium. Our results imply that this infarct-targeting gel can adhere to the damaged cardiac tissue and augment the quantity of anti-IL-1β antibodies. Moreover, the anti-IL-1β hydrogel safeguards cardiomyocytes from apoptosis by neutralizing IL-1β and inducing M2-type polarization within the myocardial infarction regions, thereby facilitating therapeutic cardiac repair. Our results emphasize the effectiveness of this synergistic comprehensive treatment modality in the management of MI and showcase its considerable potential for promoting recovery in infarcted hearts.

Causal Relationships of Circulating Inflammatory Proteins and Portal Vein Thrombosis: A Mendelian Randomization Study

Portal vein thrombosis (PVT) is commonly encountered in patients with cirrhosis, challenging our understanding of its development, particularly the ambiguous contribution of inflammation. This study utilized Mendelian randomization (MR) to explore the causal impact of circulating inflammatory markers on PVT.Employing a two-sample MR framework, we merged genome-wide association study (GWAS) meta-analysis findings of 91 inflammation-associated proteins with independent PVT data from the FinnGen consortium's R10 release. A replication analysis was performed using a distinct GWAS dataset from the UK Biobank. Inverse variance weighting, MR-Egger regression, weighted median estimator, and Mendelian Randomization Pleiotropy RESidual Sum and Outlier were used for analysis, supplemented by multivariable MR (MVMR) to adjust for cirrhosis effects.Findings indicate a significant inverse association between the genetically inferred concentration of eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) and PVT risk, evidenced by an odds ratio (OR) of 0.37 (95% confidence interval [CI]: 0.21-0.67; p = 9.2 × 10-4; adjusted for multiple testing p = 0.084). This association was corroborated in the replication phase (OR = 0.39, 95% CI: 0.17-0.93; p = 0.03) and through MVMR analysis (OR = 0.34, 95% CI: 0.15-0.79; p = 0.012). Sensitivity analyses disclosed no evidence of heterogeneity or pleiotropy.Our investigation emphasizes the 4E-BP1 as a protective factor against PVT, underscoring its potential relevance in understanding PVT pathogenesis and its implications for diagnosis and therapy.

Association Between Systemic Immune-Inflammation Index and Outcomes of Acute Myocardial Infarction: A Systemic Review and Meta-Analysis

Objective: To assess the link between systemic immune-inflammation index (SII) and risk of major adverse cardiovascular events (MACE), contrast-induced nephropathy (CIN), and overall mortality in patients with acute myocardial infarction (AMI). Patients and Methods: Electronic search of PubMed, EMBASE, Web of Science, and Scopus databases was done for observational studies with the data on the association of SII and outcomes, such as MACE, and CIN in adult (≥18 y) patients with AMI. A random-effects model was used, and the pooled effect sizes were expressed as relative risk (RR) with corresponding 95% confidence intervals (CI). Subgroup analysis was conducted on the basis of the type of AMI (ST elevation myocardial infarction and non-ST elevation myocardial infarction), sample size (≥500 and <500), and study design. GRADE assessment was used to evaluate the certainty of the evidence. Results: The analysis included 23 studies. Most studies were conducted in China (n = 13), followed by Turkey (n = 10). Majority of the studies (n = 20) had a retrospective cohort design. Patients with high SII had increased risk of MACE (RR 2.95, 95% CI: 1.25, 6.99; n = 5, I2 = 97.5%), overall mortality (RR 2.59, 95% CI: 1.64, 4.07; n = 6, I2 = 58.0%), and CIN (RR 4.58, 95% CI: 3.44, 6.10; n = 4, I2 = 0.0%), compared with patients with lower SII. Egger's test detected publication bias for MACE (p = 0.047) and overall mortality (p = 0.012) but not for CIN. These associations remained valid in subgroup analysis. Conclusion: Findings suggest that higher SII in patients with AMI is associated with increased risks of MACE, CIN, and overall mortality. This underscores SII's potential as a prognostic marker in AMI.

Association of post-thrombotic syndrome with metabolic syndrome and inflammation - a systematic review

Introduction

Post-thrombotic syndrome (PTS) is a chronic complication of deep vein thrombosis (DVT). Given its impact on vascular health, understanding risk factors for the development of PTS, as well as conditions such as metabolic syndrome that may contribute to vascular inflammation, is crucial. Metabolic syndrome is a constellation of factors that increase cardiovascular disease risk, insulin resistance, diabetes mellitus (DM), and cerebrovascular disease. Despite the established connection between metabolic syndrome and venous thromboembolism (VTE), the association between metabolic syndrome and PTS has yet to be explored.

Methods

A literature search identified studies regarding PTS and metabolic syndrome and the individual components of metabolic syndrome. A specialist performed the search, and studies were identified through PubMed, Ovid Medline, and Cochrane in accordance with PRISMA guidelines. Search terms included "post-thrombotic syndrome" and "metabolic syndrome" as well as "obesity," "hyperglycemia," "hypertension," "dyslipidemia," and "insulin resistance." Two people independently screened articles and consolidated differences. Abstract-only studies, review articles, case studies, and conference abstracts were excluded. Case reports, literature reviews, and studies not discussing PTS were excluded. Prospective cohort, retrospective cohort, and case-control studies were included. All English-based studies that met inclusion criteria published before January 3rd, 2024, were included.

Results

281 articles were initially identified. After abstract and title screening, 16 articles underwent full-text review. Of the 16 articles that underwent review, nine were included in the final analysis. Among the selected articles, eight out of nine mentioned obesity as a risk factor for developing PTS, making it the most common component mentioned. Hypertension, diabetes mellitus, hyperlipidemia, and low high-density lipoprotein (HDL) followed in prevalence. There was no noted difference between inflammatory markers in patients with and without PTS.

Conclusion

Metabolic syndrome and its components, individually and in association with PTS, are not commonly examined. Eight articles examined the association of obesity with the development of PTS. This review identified a strong association between obesity, particularly abdominal or visceral obesity, and the development of PTS. While the association between PTS and VTE is established, further research is needed to identify the role of metabolic syndrome in the development of PTS.

Pharmacological effects and mechanism of Ilexsaponin A1 in modulating platelet function

ETHNOPHARMACOLOGICAL RELEVANCE

Ilex pubescens Hook. & Arn. is a traditional Chinese medicine for promoting blood circulation. Ilexsaponin A1 (IsA), a monomer of the compound, exhibits pro-angiogenic, anti-apoptotic and anti-inflammatory activities. Nevertheless, the pharmacological effects and specific mechanisms by which IsA affects platelets remain unknown.

AIM OF THE STUDY

This study aims to investigate the antiplatelet effects of IsA and the underlying molecular mechanisms.

MATERIALS AND METHODS

Platelet aggregation and ATP release were assessed using platelet aggregometry. Flow cytometry was employed to evaluate the exposure of P-selectin, integrin αⅡbβ3 activation and calcium mobilization. Fluorescence microscopy was applied to observe platelet spreading. Clot retraction was imaged by digital camera. Protein phosphorylation regulation of major signaling pathways in platelets was determined by immunoblotting analysis. Doppler flowmetry was used to investigate the in vivo effect of IsA on FeCl3-induced carotid artery injury model. Tail vein transection was used to measure bleeding time.

RESULTS

IsA dose-dependently inhibited platelet aggregation and ATP release induced by collagen, U46619, thrombin and ADP. It also suppressed thrombin-induced P-selectin exposure and PAC-1 binding. Furthermore, IsA inhibited intracellular Ca2+ mobilization and the inward flow of extracellular Ca2+. It also influenced integrin αⅡbβ3 outside-in signaling pathways, including the inhibition of platelet spreading, clot retraction and phosphorylation of outside-in signaling molecules. In addition, IsA suppressed the phosphorylation of Syk-PLCγ2, PI3K-Akt-GSK3β and MAPKs proteins, which are downstream effectors of the collagen and thrombin receptors.

CONCLUSION

IsA inhibited platelet function and thrombus formation. This has potential to be developed into a novel therapeutic agent for the treatment of thrombotic diseases.

Steroid Utilization for Pediatric Ventricular Assist Device-Associated Inflammation and Association With Outcomes

The impact of methylprednisolone (MP) on ventricular assist device (VAD)-associated inflammation in children and its association with outcomes remains unclear. We report this single-center retrospective study of children less than 21 years old supported with a VAD from February 2018 to December 2022. Methylprednisolone utilization, serial laboratory markers of hemolysis, inflammation, anticoagulation, and VAD adverse outcomes were analyzed. Sixty-eight patients (47% male, median age 3.2 years, 54% pulsatile flow) were included. Thirty-three patients (49%) received MP during VAD support, starting at a median 9 days post-implant (interquartile range [IQR]: 7-14), and for a median of 4 days (IQR: 3-5). Post-MP, there was a significant reduction in c-reactive protein (CRP) (12.4-3.2 mg/dl, p < 0.001) and fibrinogen (592-325 mg/dl, p < 0.001). Patients receiving MP had a higher daily rate of decline of fibrinogen (p = 0.024) and higher bivalirudin dose (p = 0.013) in the 2nd week post-implant. Methylprednisolone utilization was associated with higher proportion of stroke (p = 0.023), infection (p = 0.010), and pump thrombosis (p = 0.023). Methylprednisolone is used frequently during pediatric VAD support and reduces inflammatory markers. Infectious and thrombotic complications were more common in the cohort receiving MP, and larger studies are needed to investigate this further.

Endothelial dysfunction in the kidney transplant population: Current evidence and management strategies

The endothelium modulates vascular homeostasis owing to a variety of vasoconstrictors and vasodilators. Endothelial dysfunction (ED), characterized by impaired vasodilation, inflammation, and thrombosis, triggers future cardiovascular (CV) diseases. Chronic kidney disease, a state of chronic inflammation caused by oxidative stress, metabolic abnormalities, infection, and uremic toxins damages the endothelium. ED is also associated with a decline in estimated glomerular filtration rate. After kidney transplantation, endothelial functions undergo immediate but partial restoration, promising graft longevity and enhanced CV health. However, the anticipated CV outcomes do not happen due to various transplant-related and unrelated risk factors for ED, culminating in poor CV health and graft survival. ED in kidney transplant recipients is an under-recognized and poorly studied entity. CV diseases are the leading cause of death among kidney transplant candidates with functioning grafts. ED contributes to the pathogenesis of many of the CV diseases. Various biomarkers and vasoreactivity tests are available to study endothelial functions. With an increasing number of transplants happening every year, and improved graft rejection rates due to the availability of effective immunosuppressants, the focus has now shifted to endothelial protection for the prevention, early recognition, and treatment of CV diseases.

Design and Application of Antifouling Bio-Coatings

Antifouling coatings stand out as one of the highly efficient ways to mitigate surface contamination. Traditional antifouling coatings have a major drawback: they rely on highly toxic and environmentally hazardous compounds. These substances not only lead to ecological harm but also disrupt the natural equilibrium of ecosystems. Consequently, in recent years, eco-friendly antifouling bio-coatings have emerged. This review focuses on the mechanisms and processes underlying contaminant adhesion, laying a solid foundation for grasping the principles of antifouling coating design. It further elaborates on the general strategies for developing bio-based antifouling solutions, highlighting their potential across a wide array of applications. Finally, this review carefully analyzes the current challenges confronted by antifouling bio-coatings and puts forward future development directions. Through a comprehensive overview, we aim to expand the influence of bio-based antifouling technologies, promote the further application of bio-based antifouling coatings in marine antifouling and medical antifouling fields, and provide examples for the establishment of environmental protection policies.

Emerging Targets, Novel Directions, and Innovative Approaches in Thrombosis Therapy

In clinical practice, antiplatelet, anticoagulant and fibrinolytic drugs are the mainstay of thrombosis treatment, but their potential bleeding side effects limit their widespread use. Therefore, modifying these existing drugs or developing new therapies that mitigate bleeding risks while maintaining their efficacy and utilization is necessary. Since the critical role of platelets in thrombosis is closely related to their cell surface receptors, intracellular signaling pathways and metabolism, current research focuses on these three major classes of platelet targets to develop new antithrombotic drugs. The coagulation cascade has always been the main target of anticoagulant drugs, but since the role of molecules of the contact system is more critical in thrombosis than in hemostasis, molecules targeting the contact system, such as FXIa and FXIIa, have become the main direction of anticoagulant drug research at present. Moreover, since the inflammatory response has been found to be significantly associated with thrombosis in recent years, the development of drugs that target inflammatory pathways, such as inflammasome, has also become a hot topic. This article provides a detailed description of these targets or drug formulations that are currently being investigated, including their mode of action and antithrombotic efficiency, and also points out their existing shortcomings. Moreover, antithrombotic nanomedicines can achieve precise release of drugs, which can greatly improve the thrombolytic efficiency and reduce side effects. In conclusion, this review focuses on summarizing the current new targets and new methods of antithrombotic drug research, hoping to provide a little reference for future related research.

Physiological significance of antithrombin D-helix interaction with vascular GAGs

ABSTRACT

Antithrombin (AT) is an anticoagulant serpin involved in the regulation of proteolytic activities of coagulation proteases. AT also possesses a direct anti-inflammatory function. The anticoagulant function of AT is mediated through its reactive center loop-dependent inhibition of coagulation proteases, but anti-inflammatory function of AT is mediated via its D-helix-dependent interaction with vascular glycosaminoglycans (GAGs). In vitro assays have established that therapeutic heparins promote the anticoagulant function of AT by binding D-helix and activating the serpin, however, the contribution of vascular GAGs to D-helix-dependent anticoagulant function of AT has remained poorly understood in vivo. Here, we explored this question by using 2 AT mutants, (AT-4Mut), which exhibits neither affinity for heparin nor D-helix-dependent anti-inflammatory signaling but possesses normal protease-inhibitory function and an inactive signaling-selective AT mutant in which its P1-Arg425 is deleted (AT-R425del). In vivo properties of mutants were compared with wild-type AT (AT-WT) in a small interfering RNA (siRNA)-mediated AT-deficient mouse model. The siRNA knockdown efficiently reduced expression of AT and induced robust procoagulant and proinflammatory phenotypes in mice. Infusion of both AT-WT and AT-4Mut rescued the procoagulant phenotype of AT-deficient mice as evidenced by restoration of the plasma clotting time and inhibition of fibrin deposition. AT-WT also attenuated inflammation as evidenced by reduced VCAM-1 expression and leukocyte infiltration in the liver and lungs; however, AT-4Mut failed to attenuate inflammation. Interestingly, AT-R425del also effectively attenuated inflammation in AT-depleted mice. These results suggest that interaction of AT D-helix with vascular GAGs may primarily be responsible for anti-inflammatory signaling rather than protease-inhibitory function of the serpin.

Imaging of Thromboinflammation by Multispectral 19F MRI

The close interplay between thrombotic and immunologic processes plays an important physiological role in the immune defence after tissue injury and has the aim to reduce damage and to prevent the spread of invading pathogens. However, the uncontrolled or exaggerated activation of these processes can lead to pathological thromboinflammation. Thromboinflammation has been shown to worsen the outcome of cardiovascular, autoinflammatory, or even infectious diseases. Imaging of thromboinflammation is difficult because many clinically relevant imaging techniques can only visualize either inflammatory or thrombotic processes. One interesting option for the noninvasive imaging of thromboinflammation is multispectral 19F magnetic resonance imaging (MRI). Due to the large chemical shift range of the 19F atoms, it is possible to simultaneously visualize immune cells as well as thrombus components with specific 19F tracer that have individual spectral 19F signatures. Of note, the 19F signal can be easily quantified and a merging of the 19F datasets with the anatomical 1H MRI images enables precise anatomical localization. In this review, we briefly summarize the background of 19F MRI for inflammation imaging, active targeting approaches to visualize thrombi and specific immune cells, introduce studies about multispectral 19F MRI, and summarize one study that imaged thromboinflammation by multispectral 19F MRI.

Remnant cholesterol, lipid ratios, and the severity of coronary artery lesions: a retrospective cohort study in patients with coronary heart disease

Background

Emerging genetic and observational evidence indicates that remnant cholesterol (RC) is a significant residual risk factor for cardiovascular diseases. However, there is a relative paucity of evidence exploring the correlation among RC, lipid ratios, and atherosclerotic lesion severity. This study aimed to investigate the predictive value of RC and lipid ratios alone or in combination for the severity of coronary artery stenosis in patients with coronary heart disease (CHD).

Methods

The Gensini score was used to assess the severity of coronary atherosclerotic lesions. CHD patients were categorized into mild stenosis and moderate-to-severe stenosis groups. Logistic regression was used to evaluate the risk of a high Gensini score associated with RC and lipid ratios. Our study also examined the relationship between inconsistencies in RC and non-high-density lipoprotein cholesterol (non-HDL-C) levels and the severity of coronary artery stenosis. Receiver operating characteristic (ROC) curves were used to assess the predictive power of RC and lipid ratios alone or in combination for moderate to severe coronary artery lesions.

Results

Multivariate regression models suggested that RC was a strong predictor of moderate to severe coronary artery stenosis [odds ratio (OR): 5.44, P < 0.001]. When grouped by curve-fitting inflection points, the group with inconsistent high RC/low non-HDL-C, rather than the low RC/high non-HDL-C group, was associated with an increased risk of moderate to severe coronary stenosis compared with the consistent low RC group (OR: 2.72, P < 0.001). ROC curves showed that RC predicted an area under the curve (AUC) of 0.715 for coronary stenosis severity, improving the predictive efficacy of the combined predictors comprising lipid ratios (AUC: 0.723 vs. 0.703, P < 0.05).

Conclusions

RC and various lipid ratios [triglyceride/HDL-C, total cholesterol/HDL-C, low-density lipoprotein cholesterol/HDL-C, and apoloprotein (apo)B/apoA] correlated with the degree of coronary artery stenosis in patients with CHD, suggesting that RC has potential value as a biomarker reflecting the degree of coronary artery stenosis independent of the traditional risk factors and the levels of non-HDL-C. This could enhance the predictive efficacy based on the lipid ratio model and had better predictive value for moderate to severe coronary artery lesions.

Trained immunity causes myeloid cell hypercoagulability

The pathogenic basis for increased thrombotic risk in individuals with inflammatory diseases is poorly understood. Myeloid cell "trained immunity" describes persistent innate immune cell memory arising from prior exposure to an inflammatory stimulus, leading to an enhanced immune response to subsequent unrelated stimuli. We identify enhanced myeloid cell prothrombotic activity as a maladaptive consequence of trained immunity. Lipopolysaccharide (LPS) stimulation of macrophages trained previously with β-glucan or heme exhibited significantly enhanced procoagulant activity compared to macrophages stimulated with LPS alone, which was mediated by enhanced acid sphingomyelinase-mediated tissue factor decryption. Furthermore, splenic monocytes isolated from β-glucan-trained mice revealed enhanced procoagulant activity up to 4 weeks after β-glucan administration compared to monocytes from control mice over the same time period. Moreover, hematopoietic progenitor cells and bone marrow interstitial fluid from β-glucan-trained mice had enhanced procoagulant activity compared to control mice. Trained immunity and associated metabolic perturbations may therefore represent an opportunity for targeted intervention in immunothrombotic disease development.

Chromatin changes associated with neutrophil extracellular trap formation in whole blood reflect complex immune signaling

Background

Neutrophils are key players in innate immunity, forming neutrophil extracellular traps (NETs) to defend against infections. However, excess NET formation is implicated in inflammatory conditions such as sepsis and immunothrombosis. Studying NET formation in isolated neutrophils provides important mechanistic insights but does not reflect the complexity of immune interactions in whole blood, limiting our understanding of neutrophil responses.

Methods

This study investigates chromatin accessibility changes using Assay for Transposase-Accessible Chromatin with sequencing (ATAC-Seq) during phorbol 12-myristate 13-acetate (PMA) induced NET formation in whole blood. We compared chromatin accessibility patterns in neutrophils following PMA treatment in isolation and whole blood to assess the impact of other immune cells and signaling environment.

Results

Whole blood PMA stimulation elicited consistent chromatin accessibility changes across donors, demonstrating organized chromatin decondensation during NET formation. The chromatin response was characterized by increased accessibility in genomic regions enriched for immune-specific pathways, highlighting the role of immune cell interactions in NET formation. Differentially accessible regions (DARs) present following PMA induction in whole blood and isolated neutrophils showed greater association with NET-related and inflammatory transcription factors, while DARs specific to isolated neutrophils showed fewer relevant motifs. Pathway analysis indicated that whole blood responses involved more robust activation of immune-specific pathways, such as interleukin and cytokine signaling, compared to isolated neutrophils.

Conclusions

Our findings underscore the importance of studying NET formation within a whole blood environment to capture the complexity of neutrophil responses and immune cell interactions. This understanding is crucial for identifying effective therapeutic targets in NET-associated inflammatory diseases.

Angiotensin IV does not exert prothrombotic effects in vivo

Thrombosis and thromboembolism are serious clinical complications of cardiovascular diseases and are among the leading causes of mortality worldwide. Dysregulation of the renin-angiotensin system is associated with an increased incidence of thrombotic events. Angiotensin II (AngII) is known to enhance platelet aggregation, contributing to a prothrombotic state in patients. Important biological roles of other angiotensin peptides and their receptors have been shown, but their specific role in thrombus formation remains unclear. Recent evidence suggests a prothrombotic role of angiotensin IV (AngIV). To confirm the prothrombotic effects of AngIV and to further investigate AngIV-mediated mechanisms, we utilized osmotic minipumps to administer AngIV in mice continuously over 4 weeks. AngIV treatment did not induce thrombus formation in the heart, did not affect platelet numbers, and did not enhance platelet aggregation. HGF, c-MET, or PAI-1 expression levels in the heart were not affected by AngIV treatment in mice. Furthermore, we did not observe altered platelet aggregation of human platelets incubated with HGF. These findings indicate that AngIV does not regulate key prothrombotic mechanisms.

Glutamine synthetase accelerates re-endothelialization of vascular grafts by mitigating endothelial cell dysfunction in a rat model

Endothelial cell (EC) dysfunction within the aorta has long been recognized as a prominent contributor to the progression of atherosclerosis and the subsequent failure of vascular graft transplantation. However, the direct relationship between EC dysfunction and vascular remodeling remains to be investigated. In this study, we sought to address this knowledge gap by employing a strategy involving the release of glutamine synthetase (GS), which effectively activated endothelial metabolism and mitigates EC dysfunction. To achieve this, we developed GS-loaded small-diameter vascular grafts (GSVG) through the electrospinning technique, utilizing dual-component solutions consisting of photo-crosslinkable hyaluronic acid and polycaprolactone. Through an in vitro model of oxidized low-density lipoprotein-induced injury in human umbilical vein endothelial cells (HUVECs), we provided compelling evidence that the GSVG promoted the restoration of motility, angiogenic sprouting, and proliferation in dysfunctional HUVECs by enhancing cellular metabolism. Furthermore, the sequencing results indicated that these effects were mediated by miR-122-5p-related signaling pathways. Remarkably, the GSVG also exhibited regulatory capabilities in shifting vascular smooth muscle cells towards a contractile phenotype, mitigating inflammatory responses and thereby preventing vascular calcification. Finally, our data demonstrated that GS incorporation significantly enhanced re-endothelialization of vascular grafts in a ferric chloride-injured rat model. Collectively, our results offer insights into the promotion of re-endothelialization in vascular grafts by restoring dysfunctional ECs through the augmentation of cellular metabolism.

Myocardial Infarction Platelet Gene Expression Signatures in Women

Although platelets play a critical pathogenic role in myocardial infarction (MI), few studies have characterized the MI platelet transcriptome in the acute or chronic setting in women. We report that transcripts associated with the actin cytoskeleton, Rho family GTPases, mitochondrial dysfunction, and inflammatory signaling are enriched in platelets from MI patients in the acute setting (n = 40, MI; n = 38, control) and do not significantly change over time. Furthermore, 79 platelet genes chronically elevated or suppressed after MI are associated with future cardiovascular events in an independent high-risk cohort (n = 135). Compared with women with MI with nonobstructive coronary arteries, platelets from women with MI and obstructive coronary artery disease were enriched in neutrophil activation and proinflammatory signaling pathways driven by increased tumor necrosis factor (TNF)-α signaling. Hierarchic clustering of the MI transcriptomic profile identified 3 subgroups with distinctive biological pathways and MI correlates. Our data demonstrate that platelets from MI patients are phenotypically different from MI-naïve patients in the acute and chronic settings and reveal a platelet transcriptomic signature with distinct clinical features.

Thrombin receptor PAR4 cross-activates the tyrosine kinase c-met in atrial cardiomyocytes

Thrombin supports coagulation-independent inflammation via protease-activated receptors (PAR). PAR4 is specifically increased in obese human atria, correlating with NLRP3 inflammasome activation. PAR4-mediated NLRP3 inflammasome activation in atrial cardiomyocytes is not known, nor have signaling partners been identified. Thrombin transactivates the hepatocyte growth factor receptor in some cancer cells, so we examined PAR4/c-met cross-talk in atrial cardiomyocytes and its possible significance in obesity. Cardiomyocytes from right atrial appendages (RAA) of obese patients expressed more PAR1 and PAR4 compared to non-obese. In HL-1 atrial cardiomyocytes, thrombin induced caspase-1 auto-activation and IL-1β maturation; IL-1β secretion was evoked by PAR4-activating peptide (AP), but not PAR1-AP. PAR4-AP additionally increased phosphorylated CaMKII-Thr287, mTOR-Ser2481, and Akt-Ser473 while suppressing AMPK-Thr172 phosphorylation. Total kinase levels were largely unaltered. PAR4AP rapidly increased phosphorylated c-met in HL-1 cells and over time also transcriptionally upregulated c-met. The c-met inhibitor SGX-523 abrogated the effects of PAR4-AP on CaMKII/AKT/mTOR phosphorylation but did not affect PAR4-stimulated IL-1β production. Obese human RAA contained more IL-1β, phospho-c-met, and phospho-mTOR than non-obese RAA; CamKII phosphorylation was not modified. Atria from high-fat diet (HFD) versus chow-fed mice also contained more IL-1β, together with higher myeloperoxidase activity, Acta2 mRNA total and phosphorylated c-met; these increases were blunted in PAR4-/- HFD-fed mice. Thrombin cross-activates c-met via PAR4 in atrial cardiomyocytes. Transactivated c-met contributes partially to PAR4-mediated signaling, but NLRP3 inflammasome activation appears to be largely independent of c-met. Abundance of PAR4 and activated c-met increases with obesity, providing therapeutic targets for management of adiposity-driven AF.