Oxidative Stress and Thrombosis during Aging: The Roles of Oxidative Stress in RBCs in Venous Thrombosis

miR-2467-3p/ABLIM1 Axis Mediates the Formation and Progression of Deep Vein Thrombosis by Regulating Inflammation and Oxidative Stress

Deep vein thrombosis (DVT) is a common postoperative complication of orthopaedic surgery with a complex pathogenesis mechanism. The effect of the miR-2467-3p/acting-binding LIM protein 1 (ABLIM1) axis on thrombus formation and human vascular endothelial cells (HUVECs) progression was evaluated aiming to identify a novel potential biomarker of DVT. DVT rat models were established by inferior vena cava stenosis. The expression of the miR-2467-3p/ABLIM1 axis was analyzed by PCR. HUVECs were induced with oxidative low-density lipoprotein (ox-LDL). Cell growth and motility were assessed by cell counting kit 8 (CCK8) and Transwell assay. The inflammation and oxidative stress were estimated by proinflammatory cytokines and generation of MDA and reactive oxygen species (ROS). ABLIM1 was downregulated in DVT rats. Overexpressing ABLIM1 could suppress the formation of thrombosis and alleviate inflammation and oxidative stress. In HUVECs, ox-LDL induced significantly increased miR-2467-3p and decreased ABLIM1, and miR-2467-3p could negatively regulate ABLIM1. The knockdown of miR-2467-3p could alleviate the inhibited cell growth and motility by ox-LDL, and the inflammation and oxidative stress were also attenuated. While silencing could reverse the effect of miR-2467-3p on ox-LDL-induced HUVECs. The miR-2467-3p/ABLIM1 axis regulates the occurrence and development of DVT through modulating HUVECs inflammation and oxidative stress.

Network pharmacology analysis and experimental verification of the antithrombotic active compounds of trichosanthis pericarpium (Gualoupi) in treating coronary heart disease

ETHNOPHARMACOLOGICAL RELEVANCE

Trichosanthis pericarpium (TP; Gualoupi, pericarps of Trichosanthes kirilowii Maxim) has been used in traditional Chinese medicine (TCM) to reduce heat, resolve phlegm, promote Qi, and clear chest congestion. It is also an essential herbal ingredient in the "Gualou Xiebai" formula first recorded by Zhang Zhongjing (from the Eastern Han Dynasty) in the famous TCM classic "Jin-Guì-Yào-Lüe" for treating chest impediments. According to its traditional description, Gualou Xiebai is indicated for symptoms of chest impediments, which correspond to coronary heart diseases (CHD).

AIM OF THE STUDY

This study aimed to identify the antithrombotic compounds in Gualoupi for the treatment of CHD.

MATERIALS AND METHODS

A CHD rat model was established with a combination of high-fat diet and isoproterenol hydrochloride (ISO) administration via subcutaneous multi-point injection in the back of the neck. This model was used to evaluate the antithrombotic effect of two mainstream cultivars of TP ("HaiShi GuaLou" and "WanLou") by analyzing the main components and their effects. Network pharmacology, molecular docking-based studies, and a zebrafish (Danio rerio) thrombosis model induced by phenylhydrazine was used to validate the antithrombosis components of TP.

RESULTS

TP significantly reduced the body weight of the CHD rats, improved myocardial ischemia, and reduced collagen deposition and fibrosis around the infarcted tissue. It reduced thrombosis in a dose-dependent manner and significantly reduced inflammation and oxidative stress damage. Cynaroside, isoquercitrin, rutin, citrulline, and arginine were identified as candidate active TP compounds with antithrombotic effects. The key potential targets of TP in thrombosis treatment were initially identified by molecular docking-based analysis, which showed that the candidate active compounds have a strong binding affinity to the potential targets (protein kinase C alpha type [PKCα], protein kinase C beta type [PKCβ], von Willebrand factor [vWF], and prostaglandin-endoperoxide synthase 1 [PTGS1], fibrinogen alpha [Fga], fibrinogen beta [Fgb], fibrinogen gamma [Fgg], coagulation factor II [F2], and coagulation factor VII [F7]). In addition, the candidate active compounds reduced thrombosis, improved oxidative stress damage, and down-regulated the expression of thrombosis-related genes (PKCα, PKCβ, vWF, PTGS1, Fga, Fgb, Fgg, F2, and F7) in the zebrafish model.

CONCLUSION

Cynaroside, isoquercitrin, rutin, citrulline, and arginine were identified as the active antithrombotic compounds of TP used to treat CHD. Mechanistically, the active compounds were found to be involved in oxidative stress injury, platelet activation pathway, and complement and coagulation cascade pathways.

Uvaol alleviates oxidative stress induced human umbilical vein endothelial cell injury by suppressing mitogen-activated protein kinase signaling pathway

Deep venous thrombosis (DVT) is a potentially life-threatening disorder with high morbidity. Uvaol is a natural pentacyclic triterpene possessing multiple pharmacological activities. Nevertheless, the role of uvaol in DVT is unclarified. Human umbilical vein endothelial cells (HUVECs) were treated with hydrogen peroxide (H 2 O 2 ) to mimic DVT in vitro . CCK-8 assay and flow cytometry were utilized for measuring cell viability and apoptosis, respectively. Levels of the cell injury marker, thrombosis-associated factors, inflammatory cytokines, and oxidative stress-related markers were examined by commercial assay kits. Western blotting was used for evaluating the expression of mitogen-activated protein kinase (MAPK) signaling-associated proteins. Uvaol treatment attenuated H 2 O 2 -induced HUVEC apoptosis and injury. Uvaol reduced the expression of pro-thrombotic factors and inflammatory cytokines and attenuated oxidative stress in H 2 O 2 -stimulated HUVECs. Uvaol inhibited MAPK signaling pathway in H 2 O 2 -stimulated HUVECs. Activating MAPK signaling reversed uvaol-mediated protective effects on H 2 O 2 -treated HUVECs. Uvaol treatment alleviates H 2 O 2 -induced HUVEC injury, apoptosis, and oxidative stress by inactivating MAPK signaling.

Notoginsenoside Fc alleviates oxidized low-density lipoprotein-induced endothelial cell dysfunction and upregulates PPAR-γ in vitro

BACKGROUND

Deep venous thrombosis (DVT) is a prevalent vascular disease and a major cause of morbidity and mortality worldwide. Notoginsenoside Fc (NFc) is a protopanaxadiol-type saponin that has been shown to have beneficial effects on several disorders. However, its function in DVT is unclear.

METHODS

Human umbilical vein endothelial cells (HUVECs) were treated with oxidized low-density lipoprotein (ox-LDL) to mimic DVT in vitro and treated with NFc to investigate its functions. CCK-8 assay was utilized for measuring cell viability. Western blotting was used for detecting protein levels of proinflammatory cytokines, apoptosis-related markers, and peroxisome proliferator-activated receptor-γ (PPAR-γ). Flow cytometry was performed for cell apoptosis detection. Levels of oxidative stress-related markers were examined by the DCFH-DA method and ELISA. RT-qPCR was utilized for the measurement of PPAR-γ mRNA level.

RESULTS

NFc increased the viability and suppressed inflammation, apoptosis, and oxidative stress in ox-LDL-treated HUVECs. NFc treatment induced upregulation of PPAR-γ in HUVECs.

CONCLUSION

NFc mitigates ox-LDL-induced dysfunction of HUVECs.

Oxidative Status, Iron Plasma Levels in Venous Thrombosis Patients

Exaggerated clot induces venous thrombosis (VTE); oxidative stress (OxS) can to be postulated as additional risk factor. This study evaluates firstly OxS by measuring surrogate biomarkers (malondialdehyde-MDA, 4-hydroxinonenal-4-HNE, superoxide desmutase enzyme (SOD)), secondly the iron (Fe) plasma level and thirdly the hepcidin protein (Hep) level in patients with VTE. A case control study was performed enrolling twenty hospitalized patients and an equal number of healthy individuals. In VTE patients, the following results were found. The MDA was 8.38 ± 0.5 µM/L, the 4-HNE measured 2.75 ± 0.03 µM/L and the SOD was 0.025 ± 0.01 U/mL. The I was 73.10 ± 10 µg/dL and the He was 4.77 ± 0.52 ng/mL. In the control group, the MDA measured 5.5 ± 0.6 µM/L, the 4-HNE 2.24 ± 0.021 µM/L and the SOD 0.08 ± 0.12 U/mL. The Hep was 2.1 ± 0.55 ng/mL and the Fe was 88.2 ± 9.19 µg/dL. Differences were statistically significant. Results suggest that in VTE there is activated OxS, Fe deregulation and over-production of Hep. Fe deregulation induces OxS, leading both to inflammation in the clot activator and stimulation of the pro-thrombotic status. The study highlights OxS and Fe and their regulation as intriguing indicators for risk of VTE.

A perspective on exogenous redox regulation mediated by transfused RBCs subject to the storage lesion

Granted with a potent ability to interact with and tolerate oxidative stressors, RBCs scavenge most reactive oxygen and nitrogen species (RONS) generated in circulation. This essential non-canonical function, however, renders RBCs susceptible to damage when vascular RONS are generated in excess, making vascular redox imbalance a common etiology of anemia, and thus a common indication for transfusion. This accentuates the relevance of impairments in redox metabolism during hypothermic storage, as the exposure to chronic oxidative stressors upon transfusion could be exceedingly deleterious to stored RBCs. Herein, we review the prominent mechanisms of the hypothermic storage lesion that alter the ability of RBCs to scavenge exogenous RONS as well as the associated clinical relevance.

Homozygous MTHFR C677T carriers develop idiopathic portal vein thrombosis 20 years earlier than wild type

The aim of this study was to evaluate the impact of methylene tetrahydrofolate reductase (MTHFR) rs1801133 (C→T667 transition) on age at first idiopathic portal vein thrombosis (PVT) and to identify clinical and/or laboratory variables influencing age at first PVT, including plasma homocysteine and the prothrombin rs1799963 PT (G→A transition at position 20210) (PT) mutation. A retrospective cross-sectional cohort, including 15 MTHFR TT, 32 MTHFR TC and 22 MTHFR CC idiopathic PVT participants contributing demographics, age at PVT, plasma concentrations of homocysteine and of natural anticoagulants. MTHFR TT carriers presented with a lower age at PVT than heterozygous or wild-type genotypes (31 ± 8 vs. 48 ± 15 vs. 52 ± 13 years, P  = 0.001) and were more likely to have a plasma HC concentration above the cut-off (73.3 vs. 32 vs. 50%, P  = 0.04). MTHFR TT and protein C predicted age at PVT ( P  < 0.0001 and P  = 0.06); MTHFR TT predicted plasma homocysteine ( P  = 0.05). In the MTHFR TT group, plasma homocysteine inversely related to protein C ( P  = 0.03). Plasma homocysteine predicted the extent of PVT ( P  = 0.03). Compound MTHFR TT + PT GA did not lower age at first PVT compared to MTHFR TT alone (35 ± 9 vs. 30 ± 8 years). MTHFR TT is associated with a 20-year earlier PVT presentation than heterozygous and wild-type MTHFR genotypes. The inverse relation between plasma homocysteine and protein C contributes to the prematurity of PVT in the MTHFR TT group, whereas plasma homocysteine contributes to the extent of PVT. The recent exclusion of MTHFR genotyping from the thrombophilia screen needs revisiting in this setting.

Association and Pathways between Dietary Manganese Intake and Incident Venous Thromboembolism

BACKGROUND

 The association between dietary manganese (Mn) intake and the risk of venous thromboembolism (VTE) remains unknown. We aimed to investigate the associations of dietary Mn intake with incident VTE, and the underlying mediating roles of obesity markers (body mass index [BMI] and waist circumference), hemorheological parameters (red cell distribution width [RDW], platelet count [PLT], and mean platelet volume [MPV]), and inflammatory biomarkers (C-reactive protein [CRP] and white blood cell count [WBC]) in this association.

METHODS

 A total of 202,507 adults from the UK Biobank with complete dietary data and without VTE at baseline were included. Dietary information was collected by the online 24-hour diet recall questionnaires (Oxford WebQ). The primary outcome was incident VTE, a composite of incident deep vein thrombosis (DVT) and pulmonary embolism (PE).

RESULTS

 During a median follow-up of 11.6 years, 4,750 participants developed incident VTE. Overall, there were significantly inverse relationships of dietary Mn intake with incident VTE (per 1 mg/day increment; adjusted hazard ratio [HR]: 0.92; 95% confidence interval [CI]: 0.90-0.95), incident DVT (per 1 mg/day increment; adjusted HR: 0.93; 95% CI: 0. 90-0.96), and incident PE (per 1 mg/day increment; adjusted HR: 0.91; 95% CI: 0.88-0.95). BMI, waist circumference, RDW, CRP, and WBC significantly mediated the association between dietary Mn intake and incident VTE, with the mediated proportions of 36.0, 36.5, 4.2, 4.3, and 1.6%, respectively. However, MPV and PLT did not significantly mediate the association.

CONCLUSION

 Our study shows that dietary Mn intake was inversely associated with incident VTE. The inverse association was mainly mediated by obesity, followed by inflammatory biomarkers and RDW. Our findings are just hypothesis-generating, and further confirmation of our findings in more studies is essential.

Redox regulation of platelet function and thrombosis

Platelets are well-known players in several cardiovascular diseases such as atherosclerosis and venous thrombosis. There is increasing evidence demonstrating that reactive oxygen species (ROS) are generated within activated platelets. Nicotinamide adenine dinucleotide phosphate oxidase (NOX) is a major source of ROS generation in platelets. Ligand binding to platelet receptor glycoprotein (GP) VI stimulates intracellular ROS generation consisting of a spleen tyrosine kinase-independent production involving NOX activation and a following spleen tyrosine kinase-dependent generation. In addition to GPVI, stimulation of platelet thrombin receptors (protease-activated receptors [PARs]) can also trigger NOX-derived ROS production. Our recent study found that mitochondria-derived ROS production can be induced by engagement of thrombin receptors but not by GPVI, indicating that mitochondria are another source of PAR-dependent ROS generation apart from NOX. However, mitochondria are not involved in GPVI-dependent ROS generation. Once generated, the intracellular ROS are also involved in modulating platelet function and thrombus formation; therefore, the site-specific targeting of ROS production or clearance of excess ROS within platelets is a potential intervention and treatment option for thrombotic events. In this review, we will summarize the signaling pathways involving regulation of platelet ROS production and their role in platelet function and thrombosis, with a focus on GPVI- and PAR-dependent platelet responses.

A systematic review of thromboembolic complications and outcomes in hospitalised COVID-19 patients

Thromboembolic (TE) complications [myocardial infarction (MI), stroke, deep vein thrombosis (DVT), and pulmonary embolism (PE)] are common causes of mortality in hospitalised COVID-19 patients. Therefore, this review was undertaken to explore the incidence of TE complications and mortality associated with TE complications in hospitalised COVID-19 patients from different studies. A literature search was performed using ScienceDirect and PubMed databases using the MeSH term search strategy of "COVID-19", "thromboembolic complication", "venous thromboembolism", "arterial thromboembolism", "deep vein thrombosis", "pulmonary embolism", "myocardial infarction", "stroke", and "mortality". There were 33 studies included in this review. Studies have revealed that COVID-19 patients tend to develop venous thromboembolism (PE:1.0-40.0% and DVT:0.4-84%) compared to arterial thromboembolism (stroke:0.5-15.2% and MI:0.8-8.7%). Lastly, the all-cause mortality of COVID-19 patients ranged from 4.8 to 63%, whereas the incidence of mortality associated with TE complications was between 5% and 48%. A wide range of incidences of TE complications and mortality associated with TE complications can be seen among hospitalized COVID-19 patients. Therefore, every patient should be assessed for the risk of thromboembolic complications and provided with an appropriate thromboprophylaxis management plan tailored to their individual needs.

Tea Consumption, Milk or Sweeteners Addition, Genetic Variation in Caffeine Metabolism, and Incident Venous Thromboembolism

OBJECTIVE

 The association between tea consumption and venous thromboembolism (VTE) remains unknown. We aimed to evaluate the association between tea consumption with different additives (milk and/or sweeteners) and incident VTE, and the modifying effects of genetic variation in caffeine metabolism on the association.

METHODS

 A total of 190,189 participants with complete dietary information and free of VTE at baseline in the UK Biobank were included. The primary outcome was incident VTE, including incident deep vein thrombosis and pulmonary embolism.

RESULTS

 During a median follow-up of 12.1 years, 4,485 (2.4%) participants developed incident VTE. Compared with non-tea drinkers, tea drinkers who added neither milk nor sweeteners (hazard ratio [HR]: 0.85; 95% confidence interval [95% CI]: 0.76-0.94), only milk (HR: 0.86; 95% CI: 0.80-0.93), and both milk and sweeteners to their tea (HR: 0.90; 95% CI: 0.81-0.99) had a lower risk of VTE, while those who added only sweeteners to their tea did not (HR: 0.94; 95% CI: 0.75-1.17). Moreover, there was an L-shaped relationship between tea consumption and incident VTE among tea drinkers who added neither milk nor sweeteners, only milk, and both milk and sweeteners to their tea, respectively. However, a nonsignificant association was found among tea drinkers who added only sweeteners to their tea. Genetic variation in caffeine metabolism did not significantly modify the association (p-interaction = 0.659).

CONCLUSION

 Drinking unsweetened tea, with or without added milk, was associated with a lower risk of VTE. However, there was no significant association between drinking tea with sweeteners and incident VTE.

Endothelial PTP1B Deletion Promotes VWF Exocytosis and Venous Thromboinflammation

BACKGROUND

Endothelial activation promotes the release of procoagulant extracellular vesicles and inflammatory mediators from specialized storage granules. Endothelial membrane exocytosis is controlled by phosphorylation. We hypothesized that the absence of PTP1B (protein tyrosine phosphatase 1B) in endothelial cells promotes venous thromboinflammation by triggering endothelial membrane fusion and exocytosis.

METHODS

Mice with inducible endothelial deletion of PTP1B (End.PTP1B-KO) underwent inferior vena cava ligation to induce stenosis and venous thrombosis. Primary endothelial cells from transgenic mice and human umbilical vein endothelial cells were used for mechanistic studies.

RESULTS

Vascular ultrasound and histology showed significantly larger venous thrombi containing higher numbers of Ly6G (lymphocyte antigen 6 family member G)-positive neutrophils in mice with endothelial PTP1B deletion, and intravital microscopy confirmed the more pronounced neutrophil recruitment following inferior vena cava ligation. RT2 PCR profiler array and immunocytochemistry analysis revealed increased endothelial activation and adhesion molecule expression in primary End.PTP1B-KO endothelial cells, including CD62P (P-selectin) and VWF (von Willebrand factor). Pretreatment with the NF-κB (nuclear factor kappa B) kinase inhibitor BAY11-7082, antibodies neutralizing CD162 (P-selectin glycoprotein ligand-1) or VWF, or arginylglycylaspartic acid integrin-blocking peptides abolished the neutrophil adhesion to End.PTP1B-KO endothelial cells in vitro. Circulating levels of annexin V+ procoagulant endothelial CD62E+ (E-selectin) and neutrophil (Ly6G+) extracellular vesicles were also elevated in End.PTP1B-KO mice after inferior vena cava ligation. Higher plasma MPO (myeloperoxidase) and Cit-H3 (citrullinated histone-3) levels and neutrophil elastase activity indicated neutrophil activation and extracellular trap formation. Infusion of End.PTP1B-KO extracellular vesicles into C57BL/6J wild-type mice most prominently enhanced the recruitment of endogenous neutrophils, and this response was blunted in VWF-deficient mice or by VWF-blocking antibodies. Reduced PTP1B binding and tyrosine dephosphorylation of SNAP23 (synaptosome-associated protein 23) resulting in increased VWF exocytosis and neutrophil adhesion were identified as mechanisms, all of which could be restored by NF-κB kinase inhibition using BAY11-7082.

CONCLUSIONS

Our findings show that endothelial PTP1B deletion promotes venous thromboinflammation by enhancing SNAP23 phosphorylation, endothelial VWF exocytosis, and neutrophil recruitment.

Genetic correlations, shared risk genes and immunity landscapes between COVID-19 and venous thromboembolism: evidence from GWAS and bulk transcriptome data

BACKGROUND

Patients with coronavirus disease 2019 (COVID-19) were vulnerable to venous thromboembolism (VTE), which further increases the risk of unfavorable outcomes. However, neither genetic correlations nor shared genes underlying COVID-19 and VTE are well understood.

OBJECTIVE

This study aimed to characterize genetic correlations and common pathogenic mechanisms between COVID-19 and VTE.

METHODS

We used linkage disequilibrium score (LDSC) regression and Mendelian Randomization (MR) analysis to investigate the genetic associations and causal effects between COVID-19 and VTE, respectively. Then, the COVID-19 and VTE-related datasets were obtained from the Gene Expression Omnibus (GEO) database and analyzed by bioinformatics and systems biology approaches with R software, including weighted gene co-expression network analysis (WGCNA), enrichment analysis, and single-cell transcriptome sequencing analysis. The miRNA-genes and transcription factor (TF)-genes interaction networks were conducted by NetworkAnalyst. We performed the secondary analysis of the ATAC-seq and Chip-seq datasets to address the epigenetic-regulating relationship of the shared genes.

RESULTS

This study demonstrated positive correlations between VTE and COVID-19 by LDSC and bidirectional MR analysis. A total of 26 potential shared genes were discovered from the COVID-19 dataset (GSE196822) and the VTE dataset (GSE19151), with 19 genes showing positive associations and 7 genes exhibiting negative associations with these diseases. After incorporating two additional datasets, GSE164805 (COVID-19) and GSE48000 (VTE), two hub genes TP53I3 and SLPI were identified and showed up-regulation and diagnostic capabilities in both illnesses. Furthermore, this study illustrated the landscapes of immune processes in COVID-19 and VTE, revealing the downregulation in effector memory CD8+ T cells and activated B cells. The single-cell sequencing analysis suggested that the hub genes were predominantly expressed in the monocytes of COVID-19 patients at high levels. Additionally, we identified common regulators of hub genes, including five miRNAs (miR-1-3p, miR-203a-3p, miR-210-3p, miR-603, and miR-124-3p) and one transcription factor (RELA).

CONCLUSIONS

Collectively, our results highlighted the significant correlations between COVID-19 and VTE and pinpointed TP53I3 and SLPI as hub genes that potentially link the severity of both conditions. The hub genes and their common regulators might present an opportunity for the simultaneous treatment of these two diseases.

Targeting Cysteine Oxidation in Thrombotic Disorders

Oxidative stress increases the risk for clinically significant thrombotic events, yet the mechanisms by which oxidants become prothrombotic are unclear. In this review, we provide an overview of cysteine reactivity and oxidation. We then highlight recent findings on cysteine oxidation events in oxidative stress-related thrombosis. Special emphasis is on the signaling pathway induced by a platelet membrane protein, CD36, in dyslipidemia, and by protein disulfide isomerase (PDI), a member of the thiol oxidoreductase family of proteins. Antioxidative and chemical biology approaches to target cysteine are discussed. Lastly, the knowledge gaps in the field are highlighted as they relate to understanding how oxidative cysteine modification might be targeted to limit thrombosis.

Age and outcomes following personalized antiplatelet therapy in chronic coronary syndrome patients: a post hoc analysis of the randomized PATH-PCI trial

It is particularly important to establish more effective and safer antiplatelet treatment strategies according to age. The present subanalysis of the PATH-PCI trial was to determine the safety and efficacy of any dual-antiplatelet therapy (DAPT) strategy in different age groups. We randomized 2285 chronic coronary syndrome (CCS) patients undergoing percutaneous coronary intervention (PCI) into a standard group or a personalized group from December 2016 to February 2018. The personalized group received personalized antiplatelet therapy (PAT) based on a novel platelet function test (PFT). The standard group received standard antiplatelet therapy (SAT). Then, all patients were divided according to age (under the age of 65 years and aged 65 years or over) to investigate the association and interaction of age on clinical outcomes at 180 days. In the patients under the age of 65 years, the incidence of NACEs was decreased in the personalized group compared to the standard group (5.1% vs. 8.8%, HR: 0.603, 95% CI: 0.409-0.888, P = .010). The rates of MACCEs (3.3% vs. 7.7%, HR: 0.450, 95% CI: 0.285-0.712, P = .001), MACEs (2.2% vs. 5.4%, HR: 0.423, 95% CI: 0.243-0.738, P = .002) also decreased. We did not find a significant difference in bleeding between the groups. In the patients aged 65 years or over, no difference in the primary endpoint was found (4.9% vs. 4.2%, P = .702), and comparable rates of survival were observed with the two strategies (all Ps > 0.05). The present study shows that PAT according to PFT was comparable to SAT at the 180-day follow-up for both ischemic and bleeding endpoints in CCS patients aged 65 years or over who underwent PCI. In patients under the age of 65 years, PAT can reduce ischemic events but does not increase bleeding, and it is an effective and safe treatment strategy. It may be necessary for young CCS patients after PCI to undergo PAT early after PCI.

Predictive value of admission red cell distribution width-to-platelet ratio for 30-day death in patients with spontaneous intracerebral hemorrhage: an analysis of the MIMIC database

Aim

Prognostic assessment plays an important role in the effective management of patients with spontaneous intracerebral hemorrhage (ICH). The study aimed to investigate whether elevated red cell distribution width-to-platelet ratio (RPR) at admission was related to 30-day death in patients with spontaneous intracerebral hemorrhage (ICH).

Methods

This retrospective cohort study included 2,823 adult patients with ICH from the Multiparameter Intelligent Monitoring in Intensive Care (MIMIC) III and IV databases between 2001 and 2019. The Cox proportional hazard model was utilized to evaluate the relationship between RPR levels and 30-day death risk. The area under receiver-operating characteristic curve (AUC) was used to assess the predictive ability of RPR for 30-day death in patients with ICH.

Results

At the end of the 30-day follow-up, 799 (28.30%) patients died, and the median RPR level was 0.066 (0.053, 0.087). After adjusting for confounders, the tertile 3 of RPR levels [hazard ratio (HR) = 1.37, 95% confidence interval (CI): 1.15-1.64] were associated with a higher risk of 30-day death in patients with ICH compared with tertile 1. In the stratified analyses, elevated RPR levels were found to be associated with an increased risk of 30-day death in patients aged <65 years (HR = 1.77, 95%CI: 1.29-2.43), aged ≥65 years (HR = 1.30, 95%CI: 1.05-1.61), with Glasgow Coma Score (GCS) <14 (HR = 1.65, 95%CI: 1.27-2.14), with Charlson comorbidity index (CCI) ≥4 (HR = 1.45, 95%CI: 1.17-1.80), with (HR = 1.66, 95%CI: 1.13-2.43) or without sepsis (HR = 1.32, 95%CI: 1.08-1.61), and female patients (HR = 1.75, 95%CI: 1.35-2.26) but not in male patients (P = 0.139) and patients with GCS ≥14 (P = 0.058) or CCI <4 (P = 0.188). The AUC for RPR to predict 30-day death in patients with ICH was 0.795 (95%CI: 0.763-0.828) in the testing set, indicating a good predictive ability.

Conclusion

Elevated RPR levels were correlated with an increased risk of 30-day death in patients with ICH, and RPP levels showed good predictive ability for 30-day death.

The Impact of COVID-19 on Cellular Factors Influencing Red Blood Cell Aggregation Examined in Dextran: Possible Causes and Consequences

Several studies have indicated that COVID-19 can lead to alterations in blood rheology, including an increase in red blood cell aggregation. The precise mechanisms behind this phenomenon are not yet fully comprehended. The latest findings suggest that erythrocyte aggregation significantly influences microcirculation, causes the formation of blood clots in blood vessels, and even damages the endothelial glycocalyx, leading to endothelial dysfunction. The focus of this research lies in investigating the cellular factors influencing these changes in aggregation and discussing potential causes and implications in the context of COVID-19 pathophysiology. For this purpose, the aggregation of erythrocytes in a group of 52 patients with COVID-19 pneumonia was examined in a 70 kDa Dextran solution, which eliminates the influence of plasma factors. Using image analysis, the velocities and sizes of the formed aggregates were investigated, determining their porosity. This study showed that the process of erythrocyte aggregation in COVID-19 patients, independent of plasma factors, leads to the formation of more compact, denser, three-dimensional aggregates. These aggregates may be less likely to disperse under circulatory shear stress, increasing the risk of thrombotic events. This study also suggests that cellular aggregation factors can be responsible for the thrombotic disorders observed long after infection, even when plasma factors have normalized. The results and subsequent broad discussion presented in this study can contribute to a better understanding of the potential complications associated with increased erythrocyte aggregation.

Coagulation Dysfunctions in Non-Alcoholic Fatty Liver Disease-Oxidative Stress and Inflammation Relevance

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases. Its incidence is progressively rising and it is possibly becoming a worldwide epidemic. NAFLD encompasses a spectrum of diseases accounting for the chronic accumulation of fat within the hepatocytes due to various causes, excluding excessive alcohol consumption. In this study, we aimed to focus on finding evidence regarding the implications of oxidative stress and inflammatory processes that form the multifaceted pathophysiological tableau in relation to thrombotic events that co-occur in NAFLD and associated chronic liver diseases. Recent evidence on the pathophysiology of NAFLD suggests that a complex pattern of multidirectional components, such as prooxidative, proinflammatory, and prothrombotic components, better explains the multiple factors that promote the mechanisms underlying the fatty acid excess and subsequent processes. As there is extensive evidence on the multi-component nature of NAFLD pathophysiology, further studies could address the complex interactions that underlie the development and progression of the disease. Therefore, this study aimed to describe possible pathophysiological mechanisms connecting the molecular impairments with the various clinical manifestations, focusing especially on the interactions among oxidative stress, inflammation, and coagulation dysfunctions. Thus, we described the possible bidirectional modulation among coagulation homeostasis, oxidative stress, and inflammation that occurs in the various stages of NAFLD.

Short-term beetroot juice supplementation improves muscle speed and power but does not reduce blood pressure or oxidative stress in 65-79 y old men and women

We have previously demonstrated that acute ingestion of inorganic nitrate (NO3-)-rich beetroot juice (BRJ), a source of nitric oxide (NO) via the NO3- → nitrite (NO2-) → NO pathway, can improve muscle speed and power in older individuals. It is not known, however, whether this effect is maintained or perhaps even enhanced with repeated ingestion, or if tolerance develops as with organic nitrates, e.g., nitroglycerin. Using a double-blind, placebo-controlled, crossover design, we therefore studied 16 community-dwelling older (age 71 ± 5 y) individuals after both acute and short-term (i.e., daily for 2 wk) BRJ supplementation. Blood samples were drawn and blood pressure was measured periodically during each ∼3 h experiment, with muscle function determined using isokinetic dynamometry. Acute ingestion of BRJ containing 18.2 ± 6.2 mmol of NO3- increased plasma NO3- and NO2- concentrations 23 ± 11 and 2.7 ± 2.1-fold over placebo, respectively. This was accompanied by 5 ± 11% and 7 ± 13% increases in maximal knee extensor speed (Vmax) and power (Pmax), respectively. After daily supplementation for 2 wk, BRJ ingestion elevated NO3- and NO2- levels 24 ± 12 and 3.3 ± 4.0-fold, respectively, whereas Vmax and Pmax were 7 ± 9% and 9 ± 11% higher than baseline. No changes were observed in blood pressure or in plasma markers of oxidative stress with either acute or short-term NO3- supplementation. We conclude that both acute and short-term dietary NO3- supplementation result in similar improvements in muscle function in older individuals. The magnitudes of these improvements are sufficient to offset the decline resulting from a decade or more of aging and are therefore likely to be clinically significant.

TXNIP activates NLRP3/IL-1β and participate in inflammatory response and oxidative stress to promote deep venous thrombosis

Increasing evidence indicates that deep venous thrombosis (DVT) is a common peripheral vascular disease. This study aims to investigate the mechanisms of thioredoxin-interacting protein (TXNIP) and nod-like receptor protein 3 (NLRP3) inflammasome in deep venous thrombosis (DVT). A total of 66 Sprague-Dawley (SD) rats were employed to conduct DVT model. DVT rat was treated with silenced TXNIP (si-TXNIP) lentivirus and MCC950 (a NLRP3 inhibitor). The thrombosis weight and weight/length ratio, tissue factor, inflammatory factors, superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) were measured. Hematoxylin-eosin (H&E) staining was used to investigate the pathological change. Western blotting was used to determine the protein expression level. The expression level of thioredoxin (TRx) was suppressed, whereas TXNIP and NLRP3 were elevated in DVT rat. Si-TXNIP or MCC950 could reduce the thrombosis weight and weight/length ratio, ameliorate the pathological change, and decrease inflammatory reaction. Mechanistically, si-TXNIP or MCC950 inhibited the expression levels of TXNIP, NLRP3, and interleukin (IL)-1β while elevating the TRx level, thereby suppressing the DVT. Our study indicated that si-TXNIP or MCC950 injection rescued the injury of vein induced by DVT. The possible mechanisms connected with the inhibition of TXNIP and NLRP3. TXNIP is a possible therapeutic target for DVT.

A Review of the Relationship between the Immune Response, Inflammation, Oxidative Stress, and the Pathogenesis of Sickle Cell Anaemia

Sickle cell anaemia (SCD) is a life-threatening haematological disorder which is predominant in sub-Saharan Africa and is triggered by a genetic mutation of the β-chain haemoglobin gene resulting in the substitution of glutamic acid with valine. This mutation leads to the production of an abnormal haemoglobin molecule called haemoglobin S (HbS). When deoxygenated, haemoglobin S (HbS) polymerises and results in a sickle-shaped red blood cell which is rigid and has a significantly shortened life span. Various reports have shown a strong link between oxidative stress, inflammation, the immune response, and the pathogenesis of sickle cell disease. The consequence of these processes leads to the development of vasculopathy (disease of the blood vessels) and several other complications. The role of the immune system, particularly the innate immune system, in the pathogenesis of SCD has become increasingly clear in recent years of research; however, little is known about the roles of the adaptive immune system in this disease. This review examines the interaction between the immune system, inflammation, oxidative stress, blood transfusion, and their effects on the pathogenesis of sickle cell anaemia.

Antioxidant role of methionine-containing intra- and extracellular proteins

Significant evidence suggests that reversible oxidation of methionine residues provides a mechanism capable of scavenging reactive species, thus creating a cycle with catalytic efficiency to counteract or mitigate deleterious effects of ROS on other functionally important amino acid residues. Because of the absence of MSRs in the blood plasma, oxidation of methionines in extracellular proteins is effectively irreversible and, therefore, the ability of methionines to serve as interceptors of oxidant molecules without impairment of the structure and function of plasma proteins is still debatable. This review presents data on the oxidative modification of both intracellular and extracellular proteins that differ drastically in their spatial structures and functions indicating that the proteins contain antioxidant methionines/the oxidation of which does not affect (or has a minor effect) on their functional properties. The functional consequences of methionine oxidation in proteins have been mainly identified from studies in vitro and, to a very limited extent, in vivo. Hence, much of the functioning of plasma proteins constantly subjected to oxidative stress remains unclear and requires further research to understand the evolutionary role of methionine oxidation in proteins for the maintenance of homeostasis and risk factors affecting the development of ROS-related pathologies. Data presented in this review contribute to increased evidence of antioxidant role of surface-exposed methionines and can be useful for understanding a possible mechanism that supports or impairs structure-function relationships of proteins subjected to oxidative stress.

Antioxidant Properties of Oral Antithrombotic Therapies in Atherosclerotic Disease and Atrial Fibrillation

The thrombosis-related diseases are one of the leading causes of illness and death in the general population, and despite significant improvements in long-term survival due to remarkable advances in pharmacologic therapy, they continue to pose a tremendous burden on healthcare systems. The oxidative stress plays a role of pivotal importance in thrombosis pathophysiology. The anticoagulant and antiplatelet drugs commonly used in the management of thrombosis-related diseases show several pleiotropic effects, beyond the antithrombotic effects. The present review aims to describe the current evidence about the antioxidant effects of the oral antithrombotic therapies in patients with atherosclerotic disease and atrial fibrillation.

Association of gamma-glutamyl transferase variability with risk of venous thrombosis

Gamma-glutamyl transferase (GGT) is a biomarker of inflammation, and is known to be associated with stroke and atrial fibrillation. Venous thromboembolism (VT), a not uncommon thrombotic disorder, shares similar mechanisms with other thrombotic disorders including these stroke and atrial fibrillation. Given these associations, we intended to investigate the potential association between variability in GGT and VT. The study included data from the National Health Insurance Service-Health Screening Cohort, comprising 1,085,105 participants with health examinations 3 or more times from 2003 to 2008. Variability indexes were the coefficient of variation, standard deviation, and variability independent of the mean. The occurrence of venous thromboembolism (VT) was defined with more than one claim of the following ICD-10 codes: deep VT (I80.2-80.3), pulmonary thromboembolism (I26), intraabdominal venous thrombosis (I81, I82.2, I82.3), or other VT (I82.8, I82.9). To determine the relationship of quartiles of GGT with incident VT risk, Kaplan-Meier survival curve and logrank test were used. Cox's proportional hazard regression was used to investigate the risk of VT occurrence by GGT quartile (Q1-Q4). A total of 1,085,105 subjects were incorporated in the analysis, and the average follow-up was 12.4 years (interquartile range 12.2-12.6). VT occurred in 11,769 (1.08%) patients. The GGT level was measured 5,707,768 times in this stud. Multivariable analysis showed that GGT variability were positively associated with the occurrence of VT. Compared to the Q1, the Q4 showed an adjusted HR of 1.15 (95% CI 1.09-1.21, p < 0.001) when using coefficient of variation, 1.24 (95% CI 1.17-1.31, p < 0.001) when using standard deviation, and 1.10 (95% CI 1.05-1.16, p < 0.001) when using variability independent of the mean. Increased variability of GGT may be related to an increased risk of VT. Maintaining a stable GGT level would be beneficial in reducing the risk of VT.

Insight into the transcription factors regulating Ischemic Stroke and Glioma in Response to Shared Stimuli

Cerebral ischemic stroke and glioma are the two leading causes of patient mortality globally. Despite physiological variations, 1 in 10 people who have an ischemic stroke go on to develop brain cancer, most notably gliomas. In addition, glioma treatments have also been shown to increase the risk of ischemic strokes. Stroke occurs more frequently in cancer patients than in the general population, according to traditional literature. Unbelievably, these events share multiple pathways, but the precise mechanism underlying their co-occurrence remains unknown. Transcription factors (TFs), the main components of gene expression programmes, finally determine the fate of cells and homeostasis. Both ischemic stroke and glioma exhibit aberrant expression of a large number of TFs, which are strongly linked to the pathophysiology and progression of both diseases. The precise genomic binding locations of TFs and how TF binding ultimately relates to transcriptional regulation remain elusive despite a strong interest in understanding how TFs regulate gene expression in both stroke and glioma. As a result, the importance of continuing efforts to understand TF-mediated gene regulation is highlighted in this review, along with some of the primary shared events in stroke and glioma.

Keap1-Nrf2 Heterodimer: A Therapeutic Target to Ameliorate Sickle Cell Disease

Sickle cell disease (SCD) is a monogenic inheritable disease characterized by severe anemia, increased hemolysis, and recurrent, painful vaso-occlusive crises due to the polymerization of hemoglobin S (HbS)-generated oxidative stress. Up until now, only four drugs are approved for SCD in the US. However, each of these drugs affects only a limited array of SCD pathologies. Importantly, curative therapies, such as gene therapy, or hematopoietic stem cell transplantation are not available for every patient because of their high costs, availability of donor matching, and their serious adverse effects. Therefore, there is an unmet medical need for novel therapeutic strategies that target broader SCD sequelae. SCD phenotypic severity can be alleviated by increasing fetal hemoglobin (HbF) expression. This results in the inhibition of HbS polymerization and thus sickling, and a reduction in oxidative stress. The efficacy of HbF is due to its ability to dilute HbS levels below the threshold required for polymerization and to influence HbS polymer stability in RBCs. Nuclear factor-E2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein-1 (Keap1)-complex signaling is one of the most important cytoprotective signaling controlling oxidative stress. Nrf2 is present in most organs and, after dissociation from Keap1, it accumulates in the cytoplasm, then translocates to the nucleus where it binds to the antioxidant response element (ARE) sequences and increases the expression of various cytoprotective antioxidant genes. Keeping this in mind, various researchers have proposed a role of multiple agents, more importantly tert-Butylhydroquinone (tBHQ), curcumin, etc., (having electrophilic properties) in inhibiting keap1 activity, so that Nrf2 can translocate to the nucleus to activate the gamma globin gene, thus maintaining alpha-hemoglobin-stabilizing protein (AHSP) and HbF levels. This leads to reduced oxidative stress, consequently minimizing SCD-associated complications. In this review, we will discuss the role of the Keap-1–Nrf2 complex in hemoglobinopathies, especially in SCD, and how this complex might represent a better target for more effective treatment options.

Selenium, Stroke, and Infection: A Threefold Relationship; Where Do We Stand and Where Do We Go?

Stroke is currently the second most common cause of death worldwide and a major cause of serious long-term morbidity. Selenium is a trace element with pleotropic effects on human health. Selenium deficiency has been associated with a prothrombotic state and poor immune response, particularly during infection. Our aim was to synthesize current evidence on the tripartite interrelationship between selenium levels, stroke, and infection. Although evidence is contradictory, most studies support the association between lower serum selenium levels and stroke risk and outcomes. Conversely, limited evidence on the role of selenium supplementation in stroke indicates a potentially beneficial effect of selenium. Notably, the relationship between stroke risk and selenium levels is bimodal rather than linear, with higher levels of serum selenium linked to disturbances of glucose metabolism and high blood pressure, morbidities which are, in turn, substrates for stroke. Another such substrate is an infection, albeit forming a bidirectional relationship with both stroke and the consequences of impaired selenium metabolism. Perturbed selenium homeostasis leads to impaired immune fitness and antioxidant capacity, which both favor infection and inflammation; specific pathogens may also contend with the host for transcriptional control of the selenoproteome, adding a feed-forward loop to this described process. Broader consequences of infection such as endothelial dysfunction, hypercoagulation, and emergent cardiac dysfunction both provide stroke substrates and further feed-forward feedback to the consequences of deficient selenium metabolism. In this review, we provide a synthesis and interpretation of these outlined complex interrelationships that link selenium, stroke, and infection and attempt to decipher their potential impact on human health and disease. Selenium and the unique properties of its proteome could provide both biomarkers and treatment options in patients with stroke, infection, or both.

Association of telomere length and mitochondrial DNA copy number, two biomarkers of biological aging, with the risk of venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is the third most common cardiovascular disease and occurs in all age groups, albeit the risk increases considerably with age. Previous research indicates mitochondrial dysfunction and telomere shortening in cardiovascular aging. However, in the context of VTE this has not been investigated in detail.

AIM

We aimed to explore biomarkers reflecting biological aging (i.e. human mitochondrial DNA copy number (mtDNA) and telomere length) and their association with VTE.

METHODS

mtDNA and telomere length were measured in a case-control study of 116 patients with a history of VTE and 128 age- and sex-matched healthy individuals from isolated blood using a qPCR-based assay kit. Cases had at least one unprovoked VTE event and were enrolled no earlier than 3 months after the last VTE event.

RESULTS

The mtDNA copy number was significantly lower in VTE cases compared to controls (median [IQR]: 663 per diploid cells [78.75-2204.5] vs. 2832 per diploid cells [724-4350]; p < 0.001). After adjustment for age, sex, BMI, and smoking, mtDNA copy number was independently associated with VTE risk (odds ratio per increase in 400 mtDNA per diploid cell: 0.889, 95%CI 0.834-0.947). mtDNA copy numbers were significantly different between women and men (2375 [455-3737] women vs. 893 [152-3154] men; p < 0.001). The analysis of telomere length showed no significant difference between patients and healthy controls.

CONCLUSION

Lower mtDNA levels were found in patients with VTE compared to controls, indicating an association of biological aging with risk of VTE.

Hemoglobin is an oxygen-dependent glutathione buffer adapting the intracellular reduced glutathione levels to oxygen availability

Fast changes in environmental oxygen availability translate into shifts in mitochondrial free radical production. An increase in intraerythrocytic reduced glutathione (GSH) during deoxygenation would support the detoxification of exogenous oxidants released into the circulation from hypoxic peripheral tissues. Although reported, the mechanism behind this acute oxygen-dependent regulation of GSH in red blood cells remains unknown. This study explores the role of hemoglobin (Hb) in the oxygen-dependent modulation of GSH levels in red blood cells. We have demonstrated that a decrease in Hb O₂ saturation to 50% or less observed in healthy humans while at high altitude, or in red blood cell suspensions results in rising of the intraerythrocytic GSH level that is proportional to the reduction in Hb O₂ saturation. This effect was not caused by the stimulation of GSH de novo synthesis or its release during deglutathionylation of Hb's cysteines. Using isothermal titration calorimetry and in silico modeling, we observed the non-covalent binding of four molecules of GSH to oxy-Hb and the release of two of them upon deoxygenation. Localization of the GSH binding sites within the Hb molecule was identified. Oxygen-dependent binding of GSH to oxy-Hb and its release upon deoxygenation occurred reciprocally to the binding and release of 2,3-bisphosphoglycerate. Furthermore, noncovalent binding of GSH to Hb moderately increased Hb oxygen affinity. Taken together, our findings have identified an adaptive mechanism by which red blood cells may provide an advanced antioxidant defense to respond to oxidative challenges immediately upon deoxygenation.

The Potential Role of Antioxidants in the Treatment of Peripheral Arterial Disease: A Systematic Review

Peripheral arterial disease (PAD) has a worldwide prevalence and is a significant cause of cardiovascular morbidity and mortality. Due to its high prevalence and higher rates of ischemic cardiovascular and lower-extremity events, its treatment is essential. Increased levels of oxidative stress cause disease. This review aimed to evaluate different studies of antioxidant treatments for PAD patients. A systematic search for relevant studies was performed on the PubMed, SCOPUS, and ScienceDirect databases, and 18 studies fulfilled the inclusion criteria. In total, 16.6% of the studies used natural antioxidants, and 83.3% used synthetic antioxidants. The reviewed studies show that natural antioxidants were completely effective in treating PAD, and synthetic antioxidants showed effective results in only 53% of the studies. A less-than-optimal pro-oxidant-antioxidant balance does not improve the symptoms of PAD. In conclusion, antioxidants in their natural forms are more effective for PAD patients, and ensuring the optimal pro-oxidant-antioxidant balance is an effective method for managing treatment with antioxidants.

Update on Findings about Sudden Sensorineural Hearing Loss and Insight into Its Pathogenesis

Sudden sensorineural hearing loss (SSNHL) is routinely encountered and is one of the most common emergent diseases in otolaryngology clinics. However, the etiology of SSNHL remains unclear. Due to the inaccessibility of the living human inner ear for biopsy, studies investigating the etiology of SSNHL have been performed by analyzing data obtained from examinations using peripheral blood or imaging. We updated the findings obtained from serological, magnetic resonance imaging, genetic, and viral examinations to reveal the etiology of SSNHL. Regarding viral examination, we focused on sensorineural hearing loss associated with coronavirus disease (COVID-19) because the number of correlated reports has been increasing after the outbreak. The updated findings revealed the following three possible mechanisms underlying the development of SSNHL: thrombosis and resulting vascular obstruction in the cochlea, asymptomatic viral infection and resulting damage to the cochlea, and cochlear inflammation and resulting damage to the cochlea. Thrombosis and viral infection are predominant, and cochlear inflammation can be secondarily induced through viral infection or even thrombosis. The findings about sensorineural hearing loss associated with COVID-19 supported the possibility that asymptomatic viral infection is one of the etiologies of SSNHL, and the virus can infect inner ear tissues and directly damage them.

Platelet-Neutrophil Interaction and Thromboinflammation in Diabetes: Considerations for Novel Therapeutic Approaches

Thromboinflammation has become a topic of key interest in cardiovascular disease and the prevention of diabetes complications because of the interplay between thrombosis and inflammation in diabetes. Specifically, the significant risk of vascular thrombotic disease in diabetes highlights the need for new and better therapeutic targets to help manage and prevent vascular thrombo-occlusive disease in this condition. Similarly, the prominent role of inflammation in diabetes has sparked interest in anti-inflammatory agents to better prevent and control vascular disease. Investigations on the effects of anticoagulation and antiplatelet interventions in patients with diabetes and cardiovascular disease show a potential role for these agents in decreasing morbidity and mortality. Neutrophils and platelets are key players in inflammation and wound-healing response, respectively. The interaction between neutrophils and platelets is thought to be an important driver of thromboinflammation. Therefore, this review describes the mechanisms involved in platelet-neutrophil interactions that contribute to the development or exacerbation of thromboinflammation in the context of diabetes and its associated comorbidities. The effects observed by the antithrombotic/antidiabetic treatments and physical activity/dietary interventions on attenuating thromboinflammation are discussed. These data suggest that mechanisms involved in platelet-neutrophil interaction, platelet activation/aggregation, and the recruitment of neutrophils have a promising potential to become therapeutic targets to decrease thromboinflammation in patients with diabetes.

Amine-modified nanoplastics promote the procoagulant activation of isolated human red blood cells and thrombus formation in rats

Background

Microplastics (MPs) and nanoplastics (NPs) formed from decomposed plastic are increasing environmental threats. Although MPs and NPs exposed through various routes enter the systemic circulation, the potential toxicity of those is largely unknown. We investigated whether polystyrene NPs (PS-NPs) promote the coagulation activity of red blood cells (RBCs).

Results

We tested several types of PS-NPs using human RBCs and found that amine-modified 100 nm PS-NPs were the most potent. We measured the uptake of PS-NPs using flow cytometry and confocal microscopy. Electron microscopy revealed morphological changes of RBCs by PS-NPs. PS-NPs induced the externalization of phosphatidylserine, generation of microvesicles in RBCs, and perturbations in the intracellular microenvironment. PS-NPs increased the activity of scramblases responsible for phospholipid translocation in RBCs. PS-NPs modulated the functional interaction to adjacent tissues and coagulation cascade, enhancing RBC adhesion and thrombin generation. Our observations in human RBCs were consistent with those in isolated rat RBCs, showing no inter-species differences. In rat venous thrombosis models, the intravenous administration of PS-NPs enhanced thrombus formation.

Conclusion

Amine-modified PS-NPs induce the prothrombotic activation of RBCs causing thrombus formation. We believe that our study will contribute to understanding the potential toxicity of amine-modified polystyrene particles in blood cells and cardiovascular systems.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12989-022-00500-y.

Development of Risk Prediction Model for Muscular Calf Vein Thrombosis with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Purpose

This study aims to establish a risk prediction model for muscular calf vein thrombosis (MCVT) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

Methods

The research sample consisted of 248 patients with AECOPD and all of them underwent vascular ultrasounds of both lower limbs in this retrospective study. Univariate analysis and multivariate logistic regression analysis were conducted on factors with significant group differences to screen for the independent risk factors of MCVT. A nomogram to predict the risk of MCVT was constructed and validated with bootstrap resampling.

Results

According to the exclusion criteria, 240 patients were included for analysis, divided into the MCVT group (n = 81) and the non-MCVT group (n = 159). Multivariate logistic regression analyses showed that hypertension, elevated MPV, reduced albumin (ALB), elevated D-dimer and bed rest ≥3 days were independent risk factors for MCVT in AECOPD. A nomogram model for predicting AECOPD with MCVT was established based on them. The area under the curve (AUC) of receiver operating characteristic (ROC) curve for the prediction model and the simplified Wells score was 0.784 (95% CI: 0.722–0.847) and 0.659 (95% CI: 0.583–0.735), respectively. The cut-off value and Youden index of prediction model were 0.248 and 0.454, respectively. At the same time, the sensitivity, specificity, positive predictive value, and negative predictive value of the prediction model were 85.9%, 59.5%, 84.6%, and 77.4%, respectively. The sensitivity and specificity of the simplified Wells score were 67.9% and 56.3%, respectively. Validation by the use of bootstrap resampling revealed optimal discrimination and calibration, and the decision analysis curve (DAC) suggested that this prediction model involved high clinical practicability.

Conclusion

We developed a nomogram that can predict the risk of MCVT for AECOPD patients. This model has the potential to assist clinicians in making treatment recommendations and formulating corresponding prevention measures.

Recent Developments in the Understanding of Immunity, Pathogenesis and Management of COVID-19

Coronaviruses represent a diverse family of enveloped positive-sense single stranded RNA viruses. COVID-19, caused by Severe Acute Respiratory Syndrome Coronavirus-2, is a highly contagious respiratory disease transmissible mainly via close contact and respiratory droplets which can result in severe, life-threatening respiratory pathologies. It is understood that glutathione, a naturally occurring antioxidant known for its role in immune response and cellular detoxification, is the target of various proinflammatory cytokines and transcription factors resulting in the infection, replication, and production of reactive oxygen species. This leads to more severe symptoms of COVID-19 and increased susceptibility to other illnesses such as tuberculosis. The emergence of vaccines against COVID-19, usage of monoclonal antibodies as treatments for infection, and implementation of pharmaceutical drugs have been effective methods for preventing and treating symptoms. However, with the mutating nature of the virus, other treatment modalities have been in research. With its role in antiviral defense and immune response, glutathione has been heavily explored in regard to COVID-19. Glutathione has demonstrated protective effects on inflammation and downregulation of reactive oxygen species, thereby resulting in less severe symptoms of COVID-19 infection and warranting the discussion of glutathione as a treatment mechanism.

Mahmoud E, Elansary HO, Sannaningaiah D. Effect of Biofunctional Green Synthesized MgO-Nanoparticles on Oxidative-Stress-Induced Tissue Damage and Thrombosis

The present study describes the green biofunctional synthesis of magnesium oxide (MgO) nanoparticles using the aqueous Tarenna asiatica fruit extract. The characterization of Tarenna asiatica fruit extract MgO nanoparticles (TAFEMgO NPs) was achieved by X-ray powder diffraction, UV-Vis spectroscopy, FTIR, TEM, SEM, and energy-dispersive X-ray diffraction. TAFEMgO NPs scavenged the DPPH free radicals with an IC50 value of 55.95 μg/μL, and it was highly significant compared to the standard. To authenticate the observed antioxidant potential of TAFEMgO NPs, oxidative stress was induced in red blood cells (RBC) using sodium nitrite (NaNO₂). Interestingly, TAFEMgO NPs ameliorated the RBC damage from oxidative stress by significantly restoring the stress parameters, such as the protein carbonyl content (PCC), lipid peroxidation (LPO), total thiol (TT), super-oxide dismutase (SOD), and catalase (CAT). Furthermore, oxidative stress was induced in-vivo in Sprague Dawley female rats using diclofenac (DFC). TAFEMgO NPs normalized the stress parameters in-vivo and minimized the oxidative damage in tissues. Most importantly, TAFEMgO NPs restored the function and architecture of the damaged livers, kidneys, and small intestines by regulating biochemical parameters. TAFEMgO NPs exhibited an anticoagulant effect by increasing the clotting time from 193 s in the control to 885 s in the platelet rich plasma. TAFEMgO NPs prolonged the formation of the clot process in the activated partial thromboplastin time and the prothrombin time, suggest the effective involvement in both intrinsic and extrinsic clotting pathways of the blood coagulation cascade. TAFEMgO NPs inhibited adenosine di-phosphate (ADP)-induced platelet aggregation. TAFEMgO NPs did not show hemolytic, hemorrhagic, and edema-inducing properties at the tested concentration of 100 mg/kgbody weight, suggesting its non-toxic property. In conclusion, TAFEMgO NPs mitigates the sodium nitrite (NaNO₂)- and diclofenac (DFC)-induced stress due to oxidative damage in both in vitro and in vivo experimental models.

Epigallocatechin-3-gallate exerts protective effect on epithelial function via PI3K/AKT signaling in thrombosis

BACKGROUND

Venous thrombosis (VT) is one of the most frequent cardiovascular diseases, which seriously endangers people's health. Recently, the protective role of epigallocatechin-3-gallate (EGCG) against multiple cardiovascular diseases has been well studied. Nevertheless, whether EGCG is implicated in the progression of VT is still unclear.

METHODS

Rat models of VT were established by inferior vena cava (IVC) ligation. Histological characterization of the IVC tissues was examined by hematoxylin-eosin (H&E) staining. TUNEL assay was utilized to detect cell apoptosis in IVC tissues. The concentrations of the oxidative stress biomarkers, malondialdehyde (MDA) and superoxide dismutase (SOD), were estimated by corresponding kits. In addition, the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-8 in rat plasma were estimated by ELISA. Further, the expression levels of apoptosis markers (Bax, Bcl-2, and Cleaved-caspase 3) as well as key molecules p-PI3K and p-AKT in phosphoinositide 3-kinase (PI3K)/AKT signaling pathway were assessed by western blot.

RESULTS

Compared to the sham group, the model group showed obvious thrombus formation in IVC tissues, while the EGCG treatment significantly repressed thrombosis. EGCG inhibited cell apoptosis in IVC tissues of VT rat models. The decreased SOD concentration and increased MDA concentration in the plasma of VT rats were reversed by EGCG treatment. Additionally, the elevated levels of TNF-α, IL-6 and IL-8 in the plasma of VT rats can be partially reduced by the treatment of EGCG. Finally, we also found that EGCG reduced the levels of phosphorylated (p)-PI3K and p-AKT in IVC tissues of VT rat models, indicating that the hyperactivation of the PI3K/AKT signaling pathway was inhibited by EGCG.

CONCLUSION

This study proves that EGCG alleviates thrombosis, cell apoptosis, inflammatory response, and oxidative stress injury in VT by inactivating PI3K/AKT signaling pathway.

Pb-Induced Eryptosis May Provoke Thrombosis Prior to Hemolysis

Lead (Pb) is a common metal, which can be toxic to the human body via the pollution of water or food, and can cause anemia and other diseases. However, what happens before hemolysis and anemia caused by Pb poisoning is unclear. Here, we demonstrated Pb can cause procoagulant activity of erythroid cells leading to thrombosis before hemolysis. In freshly isolated human erythroid cells, we observed that Pb resulted in hemolysis in both concentration- and time-dependent manners, but that no lysis occurred in Pb-exposed erythroid cells (≤20 μM for 1 h). Pb treatment did not cause shape changes at up to 0.5 h incubation but at 1 h incubation echinocyte and echino-spherocyte shape changes were observed, indicating that Pb can exaggerate a concentration- and time-dependent trend of shape changes in erythroid cells. After Pb treatment, ROS-independent eryptosis was shown with no increase of reactive oxygen species (ROS), but with an increase of [Ca2+]i and caspase 3 activity. With a thrombosis mouse model, we observed increased thrombus by Pb treatment (0 or 25 mg/kg). In brief, prior to hemolysis, we demonstrated Pb can cause ROS-independent but [Ca2+]i-dependent eryptosis, which might provoke thrombosis.

NonFreezable Preservation of Human Red Blood Cells at -8 °C

Red blood cell (RBC) preservation is very important in human health. The RBCs are usually preserved at 4 ± 2 °C without freezing or at a very low temperature (-80 °C or liquid nitrogen) with deep freezing. Herein, non freezable preservation of RBCs at a subzero temperature is reported to prolong the preservation time compared with that at 4 ± 2 °C. By adding glycerol and poly(ethylene glycol) (PEG) (average number molecular weight 400, PEG-400) into the preservation solution, the freezing point is decreased and the hemolysis is kept low. The cell metabolism of stored RBCs at -8 °C is reduced, and the shelf life of RBCs extends up to at least 70 days. At the end of preservation, the pH decreases a little bit to demonstrate the low metabolic rate of RBCs stored at subzero temperatures. After quick washing, the RBC survival rate is ca. 95%. The adenosine triphosphate, 2,3-diphosphoglycerate, and cell deformation ability of the washed RBCs are maintained at a high level, while the malondialdehyde is relatively low, which verifies the high quality of RBCs stored at this condition.

Migraine in Patients Undergoing PFO Closure

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Patients experiencing MHA-PFO on aspirin are characterized by a marked thrombin generation capacity sustained by an elevated number of platelets and MVs expressing a functionally active tissue factor.

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MHA-PFO patients are also characterized by an altered oxidative stress status, ie, increased platelet ROS production and blood GSSG/GSH ratio.

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This prothrombotic condition fully reverts upon PFO closure and is associated with 100% migraine remission.

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MHA-PFO plasma and GSSG, added to blood of healthy subjects, mirrored the in vivo platelet activation and this effect is blunted by N-acetylcysteine, thus supporting the etiopathogenetic role of oxidative stress in this clinical setting.

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Aspirin had little effect on the platelet prothrombotic phenotype that was better controlled by P2Y₁₂ antagonist.

The association between migraine and patent foramen ovale (PFO) has been documented. We aimed to investigate platelet activation, prothrombotic phenotype, and oxidative stress status of migraineurs with PFO on 100 mg/day aspirin, before and 6 months after PFO closure. Data show that, before PFO closure, expression of the classical platelet activation markers is comparable in patients and aspirin-treated healthy subjects. Conversely, MHA-PFO patients display an increased prothrombotic phenotype (higher tissue factor^pos platelets and microvesicles and thrombin-generation potential), sustained by an altered oxidative stress status. This phenotype, which is more controlled by P2Y₁₂-blockade than by aspirin, reverted after PFO closure together with a complete migraine remission. (pLatelEts And MigRaine iN patEnt foRamen Ovale [LEARNER]; NCT03521193)

Development and In Vitro Whole Blood Hemocompatibility Screening of Endothelium-Mimetic Multifunctional Coatings

Multifunctional antithrombotic surface modifications for blood-contacting medical devices have emerged as a solution for foreign surface-mediated coagulation disturbance. Herein, we have developed and evaluated an endothelium-inspired strategy to reduce the thrombogenicity of medical plastics by imparting nitric oxide (NO) elution and heparin immobilization on the material surface. This dual-action approach (NO+Hep) was applied to polyethylene terephthalate (PET) blood incubation vials and compared to isolated modifications. Vials were characterized to evaluate NO surface flux as well as heparin density and activity. Hemocompatibility was assessed in vitro using whole blood from human donors. Compared to unmodified surfaces, blood incubated in the NO+Hep vials exhibited reduced platelet aggregation (15% decrease AUC, p = 0.040) and prolonged plasma clotting times (aPTT = 147% increase, p < 0.0001, prothrombin time = 5% increase, p = 0.0002). Prolongation of thromboelastography reaction time and elevated antifactor Xa levels in blood from NO+Hep versus PET vials suggests some heparin leaching from the vial surface, confirmed by post-blood incubation heparin density assessment. Results suggest NO+Hep surface modification is a promising approach for blood-contacting plastics; however, careful tuning of NO flux and heparin stabilization are essential and require assessment using human blood as performed here.

Implication of COVID-19 on Erythrocytes Functionality: Red Blood Cell Biochemical Implications and Morpho-Functional Aspects

Several diseases (such as diabetes, cancer, and neurodegenerative disorders) affect the morpho-functional aspects of red blood cells, sometimes altering their normal metabolism. In this review, the hematological changes are evaluated, with particular focus on the morphology and metabolic aspects of erythrocytes. Changes in the functionality of such cells may, in fact, help provide important information about disease severity and progression. The viral infection causes significant damage to the blood cells that are altered in size, rigidity, and distribution width. Lower levels of hemoglobin and anemia have been reported in several studies, and an alteration in the concentration of antioxidant enzymes has been shown to promote a dangerous state of oxidative stress in red blood cells. Patients with severe COVID-19 showed an increase in hematological changes, indicating a progressive worsening as COVID-19 severity progressed. Therefore, monitored hematological alterations in patients with COVID-19 may play an important role in the management of the disease and prevent the risk of a severe course of the disease. Finally, monitored changes in erythrocytes and blood, in general, may be one of the causes of the condition known as Long COVID.

Hydrogen Gas Inhalation Prevents Erythrocyte Aggregation and Promotes Leukocyte Phagocytosis Together with Increases in Serum Antioxidant Activity

Hydrogen gas inhalation has not yet been elucidated to improve blood behaviors or antioxidant activity in blood. In the present study, the PEM (proton-exchange-membrane)-/platinum-plated electrode-equipped electrolyzer was examined as a hydrogen gas inhaler, which was estimated to supply 3% hydrogen as rapidly as post-operating 10–15 min, together with continuous 30 min retention of 20.8% oxygen being nearly equal to atmospheric oxygen contents. The 40 min inhalation of 3% hydrogen gas and thereafter 60 min rest were shown to enhance the antioxidant ability in human serum, as evaluated by ORAC (oxygen radical absorbing capacity)-based fluorometry, although scarcely enhanced for air dummy inhalation. Unexpectedly, antioxidant ability was 2.50-fold more enhanced for post-inhalational 0–60 min rest than during 40 min inhalation. Oxidative stress-suffering erythrocytes formed a rosary-chain-like aggregation composed of 3–6 cells, together with loss of a single hollow/biconcave-discoid structure in the cell central-part being necessary for erythrocyte passing through capillary vessels, both of which were prevented by 3% hydrogen gas inhalation. Hydrogen gas inhalation increased the intracellular foreign bodies, being distinguished from vacuole/cyst, in leucocytes, suggesting the hydrogen-activated leukocyte phagocytosis-associated events. Thus, 3%-hydrogen gas inhalation is suggested to potentially improve both the erythrocyte rheological/morphologic behaviors and the leucocyte phagocytosis-associated activity, concurrently with the enhanced antioxidant ability in blood.

Recent advances in the protective role of metallic nanoparticles in red blood cells

The interaction of nanoparticles with the biological system has increased with the increasing popularity of nanomedicines. Red blood cells (RBCs) are very sensitive, and abundant cells in the blood. They are highly prone to oxidative damage due to constant interaction with oxygen itself, foreign particles in the blood, and the lack of repair mechanism. The cell membrane of RBCs undergoes lipid peroxidation, protein oxidation, and heme degradation which results in altered membrane permeability, changes in the morphology, and functioning of RBCs. The nanoparticles induce oxidative stress, hemolysis, morphological changes, membrane deformability, and alterations in hemoglobin structure in RBCs. In this review, the effects of metallic nanoparticles and their modifications on the physiology, and life span of RBCs are discussed. The detailed analysis of the antioxidant enzymes-like activity of metal nanoparticles is expected to highlight the beneficial use of these metal nanoparticles in RBCs against oxidative stress and the development of new biosafe nanodrugs.

Angiotensin II-induced erythrocyte senescence contributes to oxidative stress

Oxidative stress may be an important cause of erythrocyte senescence. Angiotensin II (Ang II) has recently been shown to promote vascular cell senescence. However, its effects on erythrocytes remain unclear. This study aims to investigate the role of Ang II in regulating erythrocyte lifespan through oxidative stress. Experiments were performed in C57/BL6J mice infused with Ang II (1500 ng/kg per minute) or saline for 7 days. Following Ang II infusion, we found that Ang II increased erythrocyte number, hemoglobin and red blood cell distribution width (RDW). These differences were accompanied by a decrease in glutathione (GSH) and an increase in malondialdehyde (MDA) concentration. In vitro, after 24 hours of Ang II treatment, erythrocytes showed reduced surface expression of CD47 and increased phosphatidylserine exposure. In parallel, Ang II reduced the levels of antioxidant enzymes, including Cu/ZnSOD, catalase, and peroxidase 2 (PRDX2). These effects were reversed by the addition of the antioxidant N-acetyl-L-cysteine or the Ang II type 1 receptor (AT1) blocker losartan. In addition, Ang II treatment increased pro-inflammatory oxylipin, including hydroxyeicosatetraenoic acids (HETEs) and dihydroxyoctadecenoic acids (DiHOMEs) in the erythrocyte membranes. Collectively, Ang II induced erythrocyte senescence and susceptibility to eryptosis, partially due to enhanced oxidative stress.

Life-long sports engagement enhances adult erythrocyte adenylate energetics

Regular physical activity reduces age-related metabolic and functional decline. The energy stored in adenine nucleotides (ATP, ADP, and AMP) is essential to enable multiple vital functions of erythrocytes and body tissues. Our study aimed to predict the rate of age-related changes in erythrocyte adenylate energetics in athletes and untrained controls. The erythrocyte concentration of adenylates was measured in 68 elite endurance runners (EN, 20–81 years), 58 elite sprinters (SP, 21–90 years), and 62 untrained individuals (CO, 20–68 years). Resting concentrations of ATP, total adenine nucleotide pool, and ADP/AMP ratio were lowest in the CO group and highest in the SP group. The concentration of erythrocyte ADP and AMP was lowest in the EN group and highest in the CO group. In all studied groups, we found a significant increase in the concentration of most erythrocyte adenylate metabolites with age. For ADP and AMP, the trend was also significant but decreasing. Our study strongly suggests that lifelong sports and physical activity participation supports erythrocyte energetics preservation. Although the direction and the predicted rates of change are similar regardless of the training status, the concentrations of particular metabolites are more advantageous in highly trained athletes than in less active controls. Of the two analyzed types of physical training, sprint-oriented training seems to be more efficient in enhancing erythrocyte metabolism throughout adulthood and old age than endurance training.

Of mitochondrion and COVID-19

COVID-19, a pandemic disease caused by a viral infection, is associated with a high mortality rate. Most of the signs and symptoms, e.g. cytokine storm, electrolytes imbalances, thromboembolism, etc., are related to mitochondrial dysfunction. Therefore, targeting mitochondrion will represent a more rational treatment of COVID-19. The current work outlines how COVID-19's signs and symptoms are related to the mitochondrion. Proper understanding of the underlying causes might enhance the opportunity to treat COVID-19.

Coagulation and Aging: Implications for the Anesthesiologist

Purpose of Review

This narrative review focuses on aging-related modifications in coagulation resulting in increased thromboembolic and hemorrhagic risk of the elderly. We further discuss the current evidence and emerging data relating the perioperative treatment of elderly patients with antithrombotic therapy.

Recent Findings

Relevant changes in all elements of the Virchow’s triad can be found with aging. Increased blood stasis due to immobility, progressive endothelial dysfunction with altered microcirculation, elevated concentrations of several coagulation factors, and increased platelet reactivity all lead to a procoagulant state. Elderly people are, therefore, commonly treated with oral anticoagulation and antiplatelet drugs. This antithrombotic therapy might be essentially causative for their increased bleeding risk.

Summary

Elderly patients are at increased risk for thromboembolism due to changes in the hemostatic system in combination with frailty and multimorbidity. Both the thromboembolic due to aging and bleeding risk due to antithrombotic therapy need special attention in the elderly surgical patients.

Hypercoagulable State in COPD-A Comprehensive Literature Review

Chronic Obstructive Pulmonary Disease (COPD) is a chronic inflammatory disease with multisystemic manifestations. Studies either held on stable disease patients or during exacerbations have demonstrated that COPD is strongly related to venous thromboembolism and cardiovascular events. The aim of the present review of the literature was to provide an in-depth overview regarding the alterations of coagulation factors and prothrombotic changes generated in patients with stable COPD and during COPD exacerbations.