Advancing Thrombosis Research: A Novel Device for Measuring Clot Permeability.

Thromboembolism, a global leading cause of mortality, needs accurate risk assessment for effective prophylaxis and treatment. Current stratification methods fall short in predicting thrombotic events, emphasizing the need for a deeper understanding of clot properties. Fibrin clot permeability, a crucial parameter in hypercoagulable states, impacts clot structure and resistance to lysis. Current clot permeability measurement limitations propel the need for standardized methods. Prior findings underscore the importance of clot permeability in various thrombotic conditions but call for improvements and more precise, repeatable, and standardized methods. Addressing these challenges, our study presents an upgraded, portable, and cost-effective system for measuring blood clot permeability, which utilizes a pressure-based approach that adheres to Darcy's law. By enhancing precision and sensitivity in discerning clot characteristics, this innovation provides a valuable tool for assessing thrombotic risk and associated pathological conditions. In this paper, the authors present a device that is able to automatically perform the permeability measurements on plasma or fibrinogen in vitro-induced clots on specific holders (filters). The proposed device has been tailored to distinguish clot permeability, with high precision and sensitivity, between healthy subjects and high cardiovascular-risk patients. The precise measure of clot permeability represents an excellent indicator of thrombotic risk, thus allowing the clinician, also on the basis of other anamnestic and laboratory data, to attribute a risk score to the subject. The proposed instrument was characterized by performing permeability measurements in plasma and purified fibrinogen clots derived from 17 Behcet patients and 15 sex- and age-matched controls. As expected, our results clearly indicate a significant difference in plasma clot permeability in Behcet patients with respect to controls (0.0533 ± 0.0199 d vs. 0.0976 ± 0.0160 d, p < 0.001). This difference was confirmed in the patient's vs. control fibrin clots (0.0487 ± 0.0170 d vs. 0.1167 ± 0.0487 d, p < 0.001). In conclusion, our study demonstrates the feasibility, efficacy, portability, and cost-effectiveness of a novel device for measuring clot permeability, allowing healthcare providers to better stratify thrombotic risk and tailor interventions, thereby improving patient outcomes and reducing healthcare costs, which could significantly improve the management of thromboembolic diseases.

Mediterranean Diet and Oxidative Stress: A Relationship with Pain Perception in Endometriosis.

BACKGROUND: Endometriosis is a chronic and inflammatory disease associated with pelvic pain. Dietary changes may be therapeutic for chronic inflammatory processes, reducing visceral input. The aim was to evaluate the role of dietary changes according to the Mediterranean Diet (MD) on pain perception in endometriosis and their relationship with oxidative stress. METHODS: in this prospective study, we included 35 endometriosis women. At baseline (T0) and after 3 (T1) and 6 (T2) months from the start of the diet, we investigated pain intensity with VAS (Visual Analogue Scale, from 0 to 10), vitamin profile, and oxidative stress. RESULTS: we found a significant increase in the diet score (p < 0.001). At T1, patients reduced pain in terms of dyspareunia (p = 0.04), non-menstrual pelvic pain (p = 0.06), dysuria (p = 0.04), and dyschezia (p < 0.001). Dyspareunia (p = 0.002) and dyschezia (p < 0.001) were further significantly reduced also at T2. We observed a significant positive correlation between lipid peroxidation and VAS non-menstrual pelvic pain and dysuria and a significant negative correlation between Oxygen radical absorbance capacity and VAS non-menstrual pain and dyschezia. CONCLUSIONS: our findings show a clear tendency toward a relationship between pain relief in endometriosis and MD. This appears promising to treat endometriosis-related symptoms and could be considered a new effective strategy for chronic pain management in the long term.

Serum Interleukin-36 α as a Candidate Biomarker to Distinguish Behçet's Syndrome and Psoriatic Arthritis.

Behçet's syndrome (BS) is a rare systemic vasculitis characterized by different clinical manifestations. As no specific laboratory tests exist, the diagnosis relies on clinical criteria, and the differential diagnosis with other inflammatory diseases can be challenging. Indeed, in a relatively small proportion of patients, BS symptoms include only mucocutaneous, articular, gastrointestinal, and non-typical ocular manifestations, which are frequently found also in psoriatic arthritis (PsA). We investigate the ability of serum interleukin (IL)-36α-a pro-inflammatory cytokine involved in cutaneous and articular inflammatory diseases-to differentiate BS from PsA. A cross-sectional study was performed on 90 patients with BS, 80 with PsA and 80 healthy controls. Significantly lower IL-36α concentrations were found in patients with BS as compared to PsA, although in both groups IL-36α was significantly increased compared to healthy controls. An empirical cut-off of 420.6 pg/mL displayed a specificity of 0.93, with a sensitivity of 0.70 (AUC 0.82) in discriminating PsA from BS. This cut-off displayed a good diagnostic performance also in BS patients lacking highly specific BS manifestations. Our results indicate that IL-36α might be involved in the pathogenesis of both BS and PsA, and might be a candidate biomarker to support the differential diagnosis of BS.

Erythrocyte oxidative stress and thrombosis.

Thrombosis is a common disorder with a relevant burden of morbidity and mortality worldwide, particularly among elderly patients. Growing evidence demonstrated a direct role of oxidative stress in thrombosis, with various cell types contributing to this process. Among them, erythrocytes produce high quantities of intracellular reactive oxygen species (ROS) by NADPH oxidase activation and haemoglobin autoxidation. Concomitantly, extracellular ROS released by other cells in the blood flow can be uptaken and accumulate within erythrocytes. This oxidative milieu can alter erythrocyte membrane structure, leading to an impaired erythrocyte function, and promoting erythrocytes lysis, binding to endothelial cells, activation of platelet and of coagulation factors, phosphatidylserine exposure and release of microvesicles. Moreover, these abnormal erythrocytes are able to adhere to the vessel wall, contributing to thrombin generation within the thrombus. This process results in accelerated haemolysis and in a hypercoagulable state, in which structurally impaired erythrocytes contribute to increase thrombus size, to reduce its permeability and susceptibility to lysis. However, the wide plethora of mechanisms by which oxidised erythrocytes contribute to thrombosis is not completely elucidated. This review discusses the main biochemical aspects linking erythrocytes, oxidative stress and thrombosis, addressing their potential implication for clinical and therapeutic management.

Neutrophil-mediated mechanisms of damage and in-vitro protective effect of colchicine in non-vascular Behçet's syndrome.

Behçet's syndrome (BS) is a systemic vasculitis with several clinical manifestations. Neutrophil hyperactivation mediates vascular BS pathogenesis, via both a massive reactive oxygen species (ROS) production and neutrophil extracellular traps (NETs) release. Here, we investigated neutrophil-mediated mechanisms of damage in non-vascular BS manifestations and explored the in-vitro effects of colchicine in counteracting these mechanisms. NETs and intracellular ROS production was assessed in blood samples from 80 BS patients (46 with active non-vascular BS, 34 with inactive disease) and 80 healthy controls. Moreover, isolated neutrophils were incubated for 1 h with an oxidating agent [2,2'-azobis (2-amidinopropane) dihydrochloride; 250 nM] and the ability of pure colchicine pretreatment (100 ng/ml) to counteract oxidation-induced damage was assessed. Patients with active non-vascular BS showed remarkably increased NET levels [21.2, interquartile range (IQR) = 18.3-25.9 mU/ml] compared to patients with inactive disease (16.8, IQR = 13.3-20.2 mU/ml) and to controls (7.1, IQR = 5.1-8.7 mU/ml, p < 0.001]. Also, intracellular ROS tended to increase in active BS, although not significantly. In active non-vascular BS, NETs correlated with neutrophil ROS production (p < 0.001) and were particularly increased in patients with active mucosal (p < 0.001), articular (p = 0.004) and gastrointestinal symptoms (p = 0.006). In isolated neutrophils, colchicine significantly reduced oxidation-induced NET production and cell apoptosis, although not via an anti-oxidant activity. Neutrophil-mediated mechanisms might be directly involved in non-vascular BS, and NETs, more than ROS, might drive the pathogenesis of mucosal, articular and intestinal manifestations. Colchicine might be effective in counteracting neutrophils-mediated damage in BS, although further studies are needed.

Post-translational modifications of fibrinogen: implications for clotting, fibrin structure and degradation.

Fibrinogen, a blood plasma protein with a key role in hemostasis and thrombosis, is highly susceptible to post-translational modifications (PTMs), that significantly influence clot formation, structure, and stability. These PTMs, which include acetylation, amidation, carbamylation, citrullination, dichlorination, glycation, glycosylation, guanidinylation, hydroxylation, homocysteinylation, malonylation, methylation, nitration, oxidation, phosphorylation and sulphation, can alter fibrinogen biochemical properties and affect its functional behavior in coagulation and fibrinolysis. Oxidation and nitration are notably associated with oxidative stress, impacting fibrin fiber formation and promoting the development of more compact and resistant fibrin networks. Glycosylation and glycation contribute to altered fibrinogen structural properties, often resulting in changes in fibrin clot density and susceptibility to lysis, particularly in metabolic disorders like diabetes. Acetylation and phosphorylation, influenced by medications such as aspirin, modulate clot architecture by affecting fiber thickness and clot permeability. Citrullination and homocysteinylation, although less studied, are linked to autoimmune conditions and cardiovascular diseases, respectively, affecting fibrin formation and stability. Understanding these modifications provides insights into the pathophysiology of thrombotic disorders and highlights potential therapeutic targets. This review comprehensively examines the current literature on fibrinogen PTMs, their specific sites, biochemical pathways, and their consequences on fibrin clot architecture, clot formation and clot lysis.

Oxidative stress-induced fibrinogen modifications in liver transplant recipients: unraveling a novel potential mechanism for cardiovascular risk.

Background: Cardiovascular events represent a major cause of non-graft-related death after liver transplant. Evidence suggest that chronic inflammation associated with a remarkable oxidative stress in the presence of endothelial dysfunction and procoagulant environment plays a major role in the promotion of thrombosis. However, the underlying molecular mechanisms are not completely understood. Objectives: In order to elucidate the mechanisms of posttransplant thrombosis, the aim of the present study was to investigate the role of oxidation-induced structural and functional fibrinogen modifications in liver transplant recipients. Methods: A case-control study was conducted on 40 clinically stable liver transplant recipients and 40 age-matched, sex-matched, and risk factor-matched controls. Leukocyte reactive oxygen species (ROS) production, lipid peroxidation, glutathione content, plasma antioxidant capacity, fibrinogen oxidation, and fibrinogen structural and functional features were compared between patients and controls. Results: Patients displayed enhanced leukocyte ROS production and an increased plasma lipid peroxidation with a reduced total antioxidant capacity compared with controls. This systemic oxidative stress was associated with fibrinogen oxidation with fibrinogen structural alterations. Thrombin-catalyzed fibrin polymerization and fibrin resistance to plasmin-induced lysis were significantly altered in patients compared with controls. Moreover, steatotic graft and smoking habit were associated with high fibrin degradation rate. Conclusion: ROS-induced fibrinogen structural changes might increase the risk of thrombosis in liver transplant recipients.

Atherosclerosis and Endometriosis: The Role of Diet and Oxidative Stress in a Gender-Specific Disorder.

Background: Accelerated atherosclerosis in patients with endometriosis has been hypothesised, and lifestyle improvement might control cardiovascular risk. We explored cardiometabolic markers and oxidative stress and evaluated the effects of the Mediterranean Diet (MD) in modulating these markers. Methods: In this prospective study, we included 35 women with endometriosis. At baseline (T0) and after 3 (T1) and 6 (T2) months from the start of the diet, we investigated cardiometabolic parameters, lifestyle and oxidative stress. Results: After a 3-month intervention with MD, we observed a significant reduction in total cholesterol (p = 0.01) and LDL-c (p = 0.003). We observed at T1 an increase in B12 and E vitamins, folate and zinc. After 6 months, zinc (p = 0.04) and folate (p = 0.08) increased in comparison to T0. A reduction in homocysteine from T0 to T1 (p = 0.01) was found. After 3 months, an increase in Rapid Assessment of Physical Activity tool 1 (RAPA) (p < 0.001) and RAPA 2 was observed (p = 0.009). We observed high levels of oxidative stress markers at baseline. After 6 months of MD, a significant improvement in lymphocyte Reactive Oxygen Species (ROS) (p < 0.001) and total antioxidant capacity was observed (p = 0.02). Conclusions: The improvement of lifestyle, and in particular the Mediterranean dietary intervention, allowed the improvement of the metabolic and oxidative profile and overall health-related quality of life.

ROS-driven structural and functional fibrinogen modifications are reverted by interleukin-6 inhibition in Giant Cell Arteritis.

BACKGROUND: Cranial and extra-cranial vascular events are among the major determinants of morbidity and mortality in Giant Cell Arteritis (GCA). Vascular events seem mostly of inflammatory nature, although the precise pathogenetic mechanisms are still unclear. We investigated the role of oxidation-induced structural and functional fibrinogen modifications in GCA. The effects of the anti-IL6R tocilizumab in counteracting these mechanisms were also assessed. MATERIALS AND METHODS: A cross-sectional study was conducted on 65 GCA patients and 65 matched controls. Leucocyte reactive oxygen species (ROS) production, redox state, and fibrinogen structural and functional features were compared between patients and controls. In 19 patients receiving tocilizumab, pre vs post treatment variations were assessed. RESULTS: GCA patients displayed enhanced blood lymphocyte, monocyte and neutrophil ROS production compared to controls, with an increased plasma lipid peroxidation and a reduced total antioxidant capacity. This oxidative impairment resulted in a sustained fibrinogen oxidation (i.e. dityrosine content 320 (204-410) vs 136 (120-176) Relative Fluorescence Units (RFU), p < 0.0001), with marked alterations in fibrinogen secondary and tertiary structure [intrinsic fluorescence: 134 (101-227) vs 400 (366-433) RFU, p < 0.001]. Structural alterations paralleled a remarkable fibrinogen functional impairment, with a reduced ability to polymerize into fibrin and a lower fibrin susceptibility to plasmin-induced lysis. In patients receiving tocilizumab, a significant improvement in redox status was observed, accompanied by a significant improvement in fibrinogen structural and functional features (p < 0.001). CONCLUSIONS: An impaired redox status accounts for structural and functional fibrinogen modifications in GCA, suggesting a potential role of tocilizumab for cardiovascular prevention in GCA.

Blood Leukocyte ROS Production Reflects Seminal Fluid Oxidative Stress and Spermatozoa Dysfunction in Idiopathic Infertile Men.

A large proportion of infertile men do not receive a clear diagnosis, being considered as idiopathic or unexplained cases due to infertility diagnosis based on standard semen parameters. Particularly in unexplained cases, the search for new indicators seems mandatory to provide specific information. In the etiopathogenesis of male infertility oxidative stress displays important roles by negatively affecting sperm quality and function. In this study, performed in a population of 34 idiopathic infertile men and in 52 age-matched controls, redox parameters were assessed in blood, leukocytes, spermatozoa, and seminal fluid and related to semen parameters. The main findings indicate that blood oxidative stress markers reflect seminal oxidative stress. Interestingly, blood leukocyte ROS production was significantly correlated to sperm ROS production and to semen parameters. Overall, these results suggest the potential employ of blood redox markers as a relevant and adjunctive tool for sperm quality evaluation aimed to preconception care.

SIRT1 and thrombosis.

Thrombosis is a major cause of morbidity and mortality worldwide, with a complex and multifactorial pathogenesis. Recent studies have shown that SIRT1, a member of the sirtuin family of NAD + -dependent deacetylases, plays a crucial role in regulating thrombosis, modulating key pathways including endothelial activation, platelet aggregation, and coagulation. Furthermore, SIRT1 displays anti-inflammatory activity both in vitro, in vivo and in clinical studies, particularly via the reduction of oxidative stress. On these bases, several studies have investigated the therapeutic potential of targeting SIRT1 for the prevention of thrombosis. This review provides a comprehensive and critical overview of the main preclinical and clinical studies and of the current understanding of the role of SIRT1 in thrombosis.

The Impact of Oxidative Stress in Male Infertility.

At present infertility is affecting about 15% of couples and male factor is responsible for almost 50% of infertility cases. Oxidative stress, due to enhanced Reactive Oxygen Species (ROS) production and/or decreased antioxidants, has been repeatedly suggested as a new emerging causative factor of this condition. However, the central roles exerted by ROS in sperm physiology cannot be neglected. On these bases, the present review is focused on illustrating both the role of ROS in male infertility and their main sources of production. Oxidative stress assessment, the clinical use of redox biomarkers and the treatment of oxidative stress-related male infertility are also discussed.

An Insight into Giant Cell Arteritis Pathogenesis: Evidence for Oxidative Stress and SIRT1 Downregulation.

Giant cell arteritis (GCA), medium and large vessel granulomatous vasculitis affecting the elderly, is characterized by a multitude of vascular complications, including venous thrombosis, myocardial infraction and stroke. The formation of granulomatous infiltrates and the enhanced accumulation of proinflammatory cytokines are typical features of this condition. The GCA pathogenesis remains largely unknown, but recent studies have suggested the involvement of oxidative stress, mainly sustained by an enhanced reactive oxygen species (ROS) production by immature neutrophils. On this basis, in the present study, we intended to evaluate, in GCA patients, the presence of systemic oxidative stress and possible alterations in the expression level of nuclear sirtuins, enzymes involved in the inhibition of inflammation and oxidative stress. Thirty GCA patients were included in the study and compared to 30 healthy controls in terms of leukocyte ROS production, oxidative stress and SIRT1 expression. Our results clearly indicated a significant increase (p < 0.05) both in the ROS levels in the leukocyte fractions and plasma oxidative stress markers (lipid peroxidation and total antioxidant capacity) in the GCA patients compared to the healthy controls. In PBMCs from the GCA patients, a significant decrease in SIRT1 expression (p < 0.05) but not in SIRT6 and SIRT7 expression was found. Taken together, our preliminary findings indicate that, in GCA patients, plasma oxidative stress is paralleled by a reduced SIRT1 expression in PBMC. Further studies are needed to highlight if and how these alterations contribute to GCA pathogenesis.

Super-Resolution Microscopy Reveals an Altered Fibrin Network in Cirrhosis: The Key Role of Oxidative Stress in Fibrinogen Structural Modifications.

Cirrhotic patients show a reduced synthesis of both pro- and anti-coagulant factors. Recent reports indicate that they are characterized by a higher risk of thrombotic rather than hemorrhagic complications, but the mechanisms conferring this risk are not fully elucidated. Oxidative-mediated fibrinogen modifications may explain, at least in part, a prothrombotic profile. The aim of the present pilot study was to investigate the alterations in fibrinogen structure and function in patients with cirrhosis of various severity and to correlate these findings with the mechanisms of thrombus formation. We assessed in plasma specific oxidative stress markers and measured oxidative modifications, functional and structural parameters in purified fibrinogen fractions obtained from cirrhotic patients and control subjects. We enrolled 15 cirrhotic patients (5 patients belonging to each of the three Child-Turcotte-Pugh classes) and 20 age- and sex-matched healthy controls. Plasma redox status, fibrinogen oxidative modifications, thrombin-catalyzed fibrin polymerization and fibrin resistance to plasmin-induced lysis were significantly altered in cirrhotic patients and were associated to disease severity. Importantly, clot structure obtained by stimulated emission depletion (STED) super-resolution microscopy indicated modifications in fiber diameter and in clot porosity in cirrhotic patients. Fibrin fiber diameter significantly decreased in cirrhotic patients when compared to controls, and this difference became more marked with disease progression. In parallel, fibrin pore size progressively decreased along with disease severity. In cirrhotic patients, fibrinogen clot analysis and oxidative-dependent changes reveal novel structural and functional fibrinogen modifications which may favor thrombotic complications in cirrhosis.

Stem-Cell-Derived Circulating Progenitors Dysfunction in Behçet's Syndrome Patients Correlates With Oxidative Stress.

Behçet's syndrome (BS) is a systemic vasculitis considered as the prototype of a systemic inflammation-induced thrombotic condition whose pathogenesis cannot be explained just by coagulation abnormalities. Circulating hematopoietic progenitor cells (CPC), a population of rare, pre-differentiated adult stem cells originating in the bone marrow and capable of both self-renewal and multi-lineage differentiation, are mobilized in response to vascular injury and play a key role in tissue repair. In cardiovascular and thrombotic diseases, low circulating CPC number and reduced CPC function have been observed. Oxidative stress may be one of the relevant culprits that account for the dysfunctional and numerically reduced CPC in these conditions. However, the detailed mechanisms underlying CPC number reduction are unknown. On this background, the present study was designed to evaluate for the first time the possible relationship between CPC dysfunction and oxidative stress in BS patients. In BS patients, we found signs of plasma oxidative stress and significantly lower CD34+/CD45-/dim and CD34+/CD45-/dim/CD133+ CPC levels. Importantly, in all the considered CPC subsets, significantly higher ROS levels with respect to controls were observed. Higher levels of caspase-3 activity in all the considered CPC population and a strong reduction in GSH content in CPC subpopulation from BS patients with respect to controls were also observed. Interestingly, in BS patients, ROS significantly correlated with CPC number and CPC caspase-3 activity and CPC GSH content significantly correlated with CPC number, in all CPC subsets. Collectively, these data demonstrate for the first time that CPC from BS patients show signs of oxidative stress and apoptosis and that a reduced CPC number is present in BS patients with respect to controls. Interestingly, we observed an inverse correlation between circulating CPC number and CPC ROS production, suggesting a possible toxic ROS effect on CPC in BS patients. The significant correlations between ROS production/GSH content and caspase-3 activity point out that oxidative stress can represent a determinant in the onset of apoptosis in CPC. These data support the hypothesis that oxidative-stress-mediated CPC dysfunctioning may counteract their vascular repair actions, thereby contributing to the pathogenesis and the progression of vascular disease in BS.