Plasminogen activator inhibitor-1 (PAI-1): a key factor linking fibrinolysis and age-related subclinical and clinical conditions

PAI-1 Overexpression in Valvular Interstitial Cells Contributes to Hypofibrinolysis in Aortic Stenosis

Aortic stenosis (AS) is associated with hypofibrinolysis, but its mechanism is poorly understood. We investigated whether LDL cholesterol affects plasminogen activator inhibitor 1 (PAI-1) expression, which may contribute to hypofibrinolysis in AS. Stenotic valves were obtained from 75 severe AS patients during valve replacement to assess lipids accumulation, together with PAI-1 and nuclear factor-κB (NF-κB) expression. Five control valves from autopsy healthy individuals served as controls. The expression of PAI-1 in valve interstitial cells (VICs) after LDL stimulation was assessed at protein and mRNA levels. PAI-1 activity inhibitor (TM5275) and NF-κB inhibitor (BAY 11-7082) were used to suppress PAI-1 activity or NF-κB pathway. Clot lysis time (CLT) was performed to assess fibrinolytic capacity in VICs cultures. Solely AS valves showed PAI-1 expression, the amount of which was correlated with lipid accumulation and AS severity and co-expressed with NF-κB. In vitro VICs showed abundant PAI-1 expression. LDL stimulation increased PAI-1 levels in VICs supernatants and prolonged CLT. PAI-1 activity inhibition shortened CLT, while NF-κB inhibition decreased PAI-1 and SERPINE1 expression in VICs, its level in supernatants and shortened CLT. In severe AS, valvular PAI-1 overexpression driven by lipids accumulation contributes to hypofibrinolysis and AS severity.

Testing strategies used in the diagnosis of rare inherited bleeding disorders

INTRODUCTION

Rare Bleeding Disorders have a low population prevalence and may not be recognized by most clinicians. In addition, knowledge gaps of the indicated laboratory tests and their availability add to the potential for delayed diagnosis or misdiagnosis. The lack of widely available commercial, regulatory body approved esoteric tests limit them to reference laboratories, thus limiting easy access for patients.

AREAS COVERED

A literature search of Pubmed, Medline, Embase and review of international society guidelines was performed. Additional references from published articles were reviewed. A patient-centered approach to recognition and evaluation of RBD is discussed.

EXPERT OPINION

Recognition of RBD relies on obtaining a detailed patient personal and family hemostatic history. Inquiry into a history of involvement of other organ systems is important and if present should lead to suspicion of an inherited platelet disorder or a variant of Ehlers Danlos Syndrome. Multiple factors contribute to the complexity of development of efficient algorithms for diagnostic testing. Limitations in diagnostic sensitivity and specificity of screening tests, diagnostic tests, and esoteric tests further compound the complexity of establishing a diagnosis. Educational efforts focusing on clinician awareness of RBDs and available testing options are vital for optimal management of such patients.

Endotheliopathy in Acute COVID-19 and Long COVID

The pulmonary endothelium is a highly regulated organ that performs a wide range of functions under physiological and pathological conditions. Since endothelial dysfunction has been demonstrated to play a direct role in sepsis and acute respiratory distress syndrome, its role in COVID-19 has also been extensively investigated. Indeed, apart from the COVID-19-associated coagulopathy biomarkers, new biomarkers were recognised early during the pandemic, including markers of endothelial cell activation or injury. We systematically searched the literature up to 10 March 2023 for studies examining the association between acute and long COVID-19 severity and outcomes and endothelial biomarkers.

Influenza A(H1N1)pdm09 Virus Aggravates Pathology of Blood Vessels in Wistar Rats with Premorbid Acute Cardiomyopathy

Influenza virus can infect the vascular endothelium and cause endothelial dysfunction. Persons at higher risk for severe influenza are patients with acute and chronic cardiovascular disorders; however, the mechanism of influenza-induced cardiovascular system alteration remains not fully understood. The aim of the study was to assess the functional activity of mesenteric blood vessels of Wistar rats with premorbid acute cardiomyopathy infected with Influenza A(H1N1)pdm09 virus. For this, we determined (1) the vasomotor activity of mesenteric blood vessels of Wistar rats using wire myography, (2) the level of expression of three endothelial factors: endothelial nitric oxide synthase (eNOS), plasminogen activator inhibitor-1 (PAI-1), and tissue plasminogen activator (tPA) in the endothelium of mesenteric blood vessels using immunohistochemistry, and (3) the concentration of PAI-1 and tPA in the blood plasma using ELISA. Acute cardiomyopathy in animals was induced by doxorubicin (DOX) following infection with rat-adapted Influenza A(H1N1)pdm09 virus. The functional activity of mesenteric blood vessels was analyzed at 24 and 96 h post infection (hpi). Thus, the maximal response of mesenteric arteries to both vasoconstrictor and vasodilator at 24 and 96 hpi was significantly decreased compared with control. Expression of eNOS in the mesenteric vascular endothelium was modulated at 24 and 96 hpi. PAI-1 expression increased 3.47-fold at 96 hpi, while the concentration of PAI-1 in the blood plasma increased 6.43-fold at 24 hpi compared with control. The tPA concentration in plasma was also modulated at 24 hpi and 96 hpi. The obtained data indicate that influenza A(H1N1)pdm09 virus aggravates the course of premorbid acute cardiomyopathy in Wistar rats, causing pronounced dysregulation of endothelial factor expression and vasomotor activity impairment of mesenteric arteries.

Pathophysiological, immunogenetic, anatomopathological profile of thrombophilia in pregnancy

Thrombophilic states have been associated with early and/or late pregnancy loss and possibly other severe obstetrical complications. Pregnancy-induced hypercoagulability, increased stasis, and the consequences of inherited and acquired thrombophilia are just a few of the factors that contribute to the development of thrombosis in pregnancy. In this review, we illustrate the impact that these factors have on the development of thrombophilia during pregnancy. We also explore how thrombophilia impact pregnancy outcomes. Next, we discuss how human leukocyte antigen G plays a part in thrombophilia during pregnancy by regulating cytokine release to prevent trophoblastic cell invasion and maintain local immunotolerance constant. Human leukocyte antigen class E is briefly explored with thrombophilia in pregnancy. Regarding the anatomopathologic aspect, we describe the different histopathological lesions of the placenta found in women with thrombophilia.

Soluble components from mesenchymal stromal cell processing exert anti-inflammatory effects and facilitate ischemic muscle regeneration

BACKGROUND AIMS

Skeletal muscle regeneration after severe damage is reliant on local stem cell proliferation and differentiation, processes that are tightly regulated by macrophages. Peripheral artery disease is a globally prevalent cardiovascular disease affecting millions of people. Progression of the disease leads to intermittent claudication, subsequent critical limb ischemia and muscle injury. Tissue-derived and ex vivo-expanded mesenchymal stromal cells (MSCs) for skeletal muscle regeneration have been studied, but pre-clinical and clinical results have not been consistent. As a result, the potential therapeutic efficacy and associated repair mechanisms of MSCs remain unclear. Numerous studies have demonstrated the vulnerability of delivered MSCs, with a precipitous drop in cell viability upon transplantation. This has prompted investigation into the therapeutic benefit of apoptotic cells, microvesicles, exosomes and soluble signals that are released upon cell death.

METHODS

In this study, we characterized various components produced by MSCs after cell death induction under different conditions. We discovered anti-inflammatory and pro-regenerative effects produced by cell components following a freeze and thaw (F&T) process on macrophage polarization in vitro. We further investigated the underlying mechanisms of macrophage polarization by those components resulting from severe cell death induction.

RESULTS

We found potent therapeutic effects from F&T-induced cell debris are dependent on the externalization of phosphatidylserine on the plasma membrane. In contrast, effects from the supernatant of F&T-induced cell death primarily depends on the released protein content. We then applied the F&T-induced cell supernatant to an animal model of peripheral artery disease to treat muscle injury caused by severe ischemia. Treatment with the F&T supernatant but not the vulnerable MSCs resulted in significantly improved recovery of muscle function, blood flow and morphology and inflammation resolution in the affected muscles 2 weeks after injury.

CONCLUSIONS

This study validates the therapeutic potential of F&T-induced supernatant obviating the need for a viable population from vulnerable MSCs to treat injury, thus providing a roadmap for cell-free therapeutic approaches for tissue regeneration.

COVID-19 and Pulmonary Angiogenesis: The Possible Role of Hypoxia and Hyperinflammation in the Overexpression of Proteins Involved in Alveolar Vascular Dysfunction

COVID-19 has been considered a vascular disease, and inflammation, intravascular coagulation, and consequent thrombosis may be associated with endothelial dysfunction. These changes, in addition to hypoxia, may be responsible for pathological angiogenesis. This research investigated the impact of COVID-19 on vascular function by analyzing post-mortem lung samples from 24 COVID-19 patients, 10 H1N1pdm09 patients, and 11 controls. We evaluated, through the immunohistochemistry technique, the tissue immunoexpressions of biomarkers involved in endothelial dysfunction, microthrombosis, and angiogenesis (ICAM-1, ANGPT-2, and IL-6, IL-1β, vWF, PAI-1, CTNNB-1, GJA-1, VEGF, VEGFR-1, NF-kB, TNF-α and HIF-1α), along with the histopathological presence of microthrombosis, endothelial activation, and vascular layer hypertrophy. Clinical data from patients were also observed. The results showed that COVID-19 was associated with increased immunoexpression of biomarkers involved in endothelial dysfunction, microthrombosis, and angiogenesis compared to the H1N1 and CONTROL groups. Microthrombosis and vascular layer hypertrophy were found to be more prevalent in COVID-19 patients. This study concluded that immunothrombosis and angiogenesis might play a key role in COVID-19 progression and outcome, particularly in patients who die from the disease.

Fibrinolysis: an illustrated review

In response to vessel injury (or other pathological conditions), the hemostatic process is activated, resulting in a fibrous, cellular-rich structure commonly referred to as a blood clot. Succeeding the clot's function in wound healing, it must be resolved. This illustrated review focuses on fibrinolysis-the degradation of blood clots or thrombi. Fibrin is the main mechanical and structural component of a blood clot, which encases the cellular components of the clot, including platelets and red blood cells. Fibrinolysis is the proteolytic degradation of the fibrin network that results in the release of the cellular components into the bloodstream. In the case of thrombosis, fibrinolysis is required for restoration of blood flow, which is accomplished clinically through exogenously delivered lytic factors in a process called external lysis. Fibrinolysis is regulated by plasminogen activators (tissue-type and urokinase-type) that convert plasminogen into plasmin to initiate fiber lysis and lytic inhibitors that impede this lysis (plasminogen activator inhibitors, alpha 2-antiplasmin, and thrombin activatable fibrinolysis inhibitor). Furthermore, the network structure has been shown to regulate lysis: thinner fibers and coarser clots lyse faster than thicker fibers and finer clots. Clot contraction, a result of platelets pulling on fibers, results in densely packed red blood cells (polyhedrocytes), reduced permeability to fibrinolytic factors, and increased fiber tension. Extensive research in the field has allowed for critical advancements leading to improved thrombolytic agents. In this review, we summarize the state of the field, highlight gaps in knowledge, and propose future research questions.

The Variants in ADIPOQ are Associated with Maternal Circulating Adipokine Profile in Gestational Diabetes Mellitus

Background

Gestational diabetes mellitus (GDM) is the most common association with hyperglycemia and glucose intolerance during pregnancy. The adipokines play an important to control insulin secretion and glucose. This study aimed to investigate the association between maternal circulating adipokine levels and ADIPOQ gene polymorphism among pregnant women subjects with GDM and normal glucose tolerance (NGT).

Methods

Participants including 229 normal pregnant women and 197 GDM pregnant women were enrolled from 2015 to 2018 at Siriraj hospital. Serum adipokine levels including adiponectin, adipsin/factor D, NGAL/Lipocalin-2, total PAI-1, and resistin were measured by immunoassay. ADIPOQ variations were investigated including -11377C/G (rs266729), +45T/G (rs2241766), and +276G/T (rs1501299).

Results

Serum adiponectin concentration was also significantly decreased among the GDM who had aged less than 35 years old whereas adipsin levels were significantly lower among the GDM who had aged more than 35 years old. Also, adiponectin and total PAI-1 levels were significantly lower among the GDM who had a BMI of less than 30 kg/m². The G allele frequency of ADIPOQ +45T/G was significantly different between GDM and controls (p = 0.03). ADIPOQ +45T/G was associated with an increased risk of GDM (odds ratio [OR]: 1.554; 95% confidence interval [CI]: 1.010-2.390; p=0.045). The -11377C/G was affected by the level of adiponectin (p = 0.04). The C allele of -11377C/G SNP declined serum adiponectin levels and may be a risk factor for GDM.

Conclusion

This study revealed that genetics play important roles in circulating adipokines among pregnant women. ADIPOQ polymorphisms had significant associations with adiponectin levels in GDM patients.

Biomechanical forces and signals operating in the ovary during folliculogenesis and their dysregulation: implications for fertility

BACKGROUND

Folliculogenesis occurs in the highly dynamic environment of the ovary. Follicle cyclic recruitment, neo-angiogenesis, spatial displacement, follicle atresia and ovulation stand out as major events resulting from the interplay between mechanical forces and molecular signals. Morphological and functional changes to the growing follicle and to the surrounding tissue are required to produce oocytes capable of supporting preimplantation development to the blastocyst stage.

OBJECTIVE AND RATIONALE

This review will summarize the ovarian morphological and functional context that contributes to follicle recruitment, growth and ovulation, as well as to the acquisition of oocyte developmental competence. We will describe the changes occurring during folliculogenesis to the ovarian extracellular matrix (ECM) and to the vasculature, their influence on the mechanical properties of the ovarian tissue, and, in turn, their influence on the regulation of signal transduction. Also, we will outline how their dysregulation might be associated with pathologies such as polycystic ovary syndrome (PCOS), endometriosis or premature ovarian insufficiency (POI). Finally, for each of these three pathologies, we will highlight therapeutic strategies attempting to correct the altered biomechanical context in order to restore fertility.

SEARCH METHODS

For each area discussed, a systematic bibliographical search was performed, without temporal limits, using PubMed Central, Web of Science and Scopus search engines employing the keywords extracellular matrix, mechanobiology, biomechanics, vasculature, angiogenesis or signalling pathway in combination with: ovary, oogenesis, oocyte, folliculogenesis, ovarian follicle, theca, granulosa, cumulus, follicular fluid, corpus luteum, meiosis, oocyte developmental competence, preimplantation, polycystic ovary syndrome, premature ovarian insufficiency or endometriosis.

OUTCOMES

Through search engines queries, we yielded a total of 37 368 papers that were further selected based on our focus on mammals and, specifically, on rodents, bovine, equine, ovine, primates and human, and also were trimmed around each specific topic of the review. After the elimination of duplicates, this selection process resulted in 628 papers, of which 287 were cited in the manuscript. Among these, 89.2% were published in the past 22 years, while the remaining 8.0%, 2.4% or 0.3% were published during the 1990s, 1980s or before, respectively. During folliculogenesis, changes occur to the ovarian ECM composition and organization that, together with vasculature modelling around the growing follicle, are aimed to sustain its recruitment and growth, and the maturation of the enclosed oocyte. These events define the scenario in which mechanical forces are key to the regulation of cascades of molecular signals. Alterations to this context determine impaired folliculogenesis and decreased oocyte developmental potential, as observed in pathological conditions which are causes of infertility, such as PCOS, endometriosis or POI.

WIDER IMPLICATIONS

The knowledge of these mechanisms and the rules that govern them lay a sound basis to explain how follicles recruitment and growth are modulated, and stimulate insights to develop, in clinical practice, strategies to improve follicular recruitment and oocyte competence, particularly for pathologies like PCOS, endometriosis and POI.

Benefits of Tranexamic Acid in Total Knee Arthroplasty: A Classification and Regression Tree Analysis in Function of Instrumentation, BMI, and Gender

Tranexamic acid (TXA) is an antifibrinolytic drug that reduces blood loss in patients that undergo Total knee arthroplasty (TKA). Few studies compare its effect on conventional instrumentation (CI) versus patient-specific instrumentation (PSI). The main objective of this study was to understand analytically how TXA usage in both instrumentations influenced blood loss in TKA differently and see if the differences seen could be explained by the patient's body mass index (BMI) and gender. This nonrandomized retrospective study sample consisted of 688 TKA procedures performed on patients who had symptomatic arthrosis resistant to conservative treatment. Descriptive analysis was used to evaluate blood loss using hemoglobin (Hb) mean values and mean variation (%). The Classification and Regression Tree (CRT) method was applied to understand how the independent variables affected the dependent variable. Comparing patients submitted to the same instrumentation, where some received TXA and others did not, patients that received TXA had lower blood loss. Comparing patients who underwent TKA with different instrumentations and without the use of TXA, it was found that patients who underwent TKA with PSI had lower blood loss than those who underwent TKA with CI. However, when these same instruments were compared again, but associated with the use of TXA, the opposite was true with patients undergoing TKA with PSI showing greater blood loss than patients undergoing TKA with CI. TXA usage in TKA is significantly beneficial in minimizing blood loss and regardless of instrumentation. When using TXA, the lowest blood loss was obtained in patients with higher BMI and submitted to TKA with CI. This is most likely explained by the synergistic antifibrotic effect of TXA with adipokines, such as plasminogen activator inhibitor-1 (PAI-1), found in the femoral bone marrow which is perforated using CI. If, however, TXA wasn't used, the lowest blood loss was obtained in patients submitted to TKA with PSI.

Adipokines from white adipose tissue in regulation of whole body energy homeostasis

Diseases originating from altered energy homeostasis including obesity, and type 2 diabetes are rapidly increasing worldwide. Research in the last few decades on animal models and humans demonstrates that the white adipose tissue (WAT) is critical for energy balance and more than just an energy storage site. WAT orchestrates the whole-body metabolism through inter-organ crosstalk primarily mediated by cytokines named "Adipokines". The adipokines influence metabolism and fuel selection of the skeletal muscle and liver thereby fine-tuning the load on WAT itself in physiological conditions like starvation, exercise and cold. In addition, adipokine secretion is influenced by various pathological conditions like obesity, inflammation and diabetes. In this review, we have surveyed the current state of knowledge on important adipokines and their significance in regulating energy balance and metabolic diseases. Furthermore, we have summarized the interplay of pro-inflammatory and anti-inflammatory adipokines in the modulation of pathological conditions.

"Super" SERPINs-A stabilizing force against fibrinolysis in thromboinflammatory conditions

The superfamily of serine protease inhibitors (SERPINs) are a class of inhibitors that utilise a dynamic conformational change to trap and inhibit their target enzymes. Their powerful nature lends itself well to regulation of complex physiological enzymatic cascades, such as the haemostatic, inflammatory and complement pathways. The SERPINs α2-antiplasmin, plasminogen-activator inhibitor-1, plasminogen-activator inhibitor-2, protease nexin-1, and C1-inhibitor play crucial inhibitory roles in regulation of the fibrinolytic system and inflammation. Elevated levels of these SERPINs are associated with increased risk of thrombotic complications, obesity, type 2 diabetes, and hypertension. Conversely, deficiencies of these SERPINs have been linked to hyperfibrinolysis with bleeding and angioedema. In recent years SERPINs have been implicated in the modulation of the immune response and various thromboinflammatory conditions, such as sepsis and COVID-19. Here, we highlight the current understanding of the physiological role of SERPINs in haemostasis and inflammatory disease progression, with emphasis on the fibrinolytic pathway, and how this becomes dysregulated during disease. Finally, we consider the role of these SERPINs as potential biomarkers of disease progression and therapeutic targets for thromboinflammatory diseases.

Circadian rhythm of plasminogen activator inhibitor-1 and cardiovascular complications in type 2 diabetes

Cardiovascular complications are a common death cause in type 2 diabetes patients, as they are often combined. Plasminogen-activator Inhibitor 1 (PAI-1) participates in the development and progression of cardiovascular complications in diabetes. Insulin resistance increases PAI-1 production, and high PAI-1 levels lead to an environment conducive to thrombosis and earlier and more severe vascular disease. Current evidence also suggests that PAI-1 has a rhythmic profile of circadian fluctuations and acrophase in the morning within a single day, which might explain the high morning incidence of cardiovascular events. Thus, PAI-1 is a possible drug target. Although several PAI-1 inhibitors have been developed, none have yet been allowed for clinical use. Research on rhythm has also led to the concept of "chronotherapy", a rhythm-based drug regimen expected to improve the treatment of cardiovascular complications in diabetic patients. Herein, we searched several databases and reviewed relevant articles to describe the circadian rhythm characteristics and endogenous molecular mechanisms of PAI-1, its relationship with insulin resistance, the causes of cardiovascular complications caused by PAI-1, and the current development of PAI-1 inhibitors. We also summarized the possibility of using the circadian rhythm of PAI-1 to treat cardiovascular complications in diabetic patients.

Plasminogen activator inhibitor-1 levels as an indicator of severity and mortality for COVID-19

OBJECTIVE

Coronavirus disease-19 (COVID-19) is a multisystemic disease that can cause severe illness and mortality by exacerbating symptoms such as thrombosis, fibrinolysis, and inflammation. Plasminogen activator inhibitor-1 (PAI-1) plays an important role in regulating fibrinolysis and may cause thrombotic events to develop. The goal of this study is to examine the relationship between PAI-1 levels and disease severity and mortality in relation to COVID-19.

METHODS

A total of 71 hospitalized patients were diagnosed with COVID-19 using real time-polymerase chain reaction tests. Each patient underwent chest computerized tomography (CT). Data from an additional 20 volunteers without COVID-19 were included in this single-center study. Each patient's PAI-1 data were collected at admission, and the CT severity score (CT-SS) was then calculated for each patient.

RESULTS

The patients were categorized into the control group (n=20), the survivor group (n=47), and the non-survivor group (n=24). In the non-survivor group, the mean age was 75.3±13.8, which is higher than in the survivor group (61.7±16.9) and in the control group (59.5±11.2), (p=0.001). When the PAI-1 levels were compared between each group, the non-survivor group showed the highest levels, followed by the survivor group and then the control group (p<0.001). Logistic regression analysis revealed that age, PAI-1, and disease severity independently predicted COVID-19 mortality rates. In this study, it was observed that PAI-1 levels with >10.2 ng/mL had 83% sensitivity and an 83% specificity rate when used to predict mortality after COVID-19. Then, patients were divided into severe (n=33) and non-severe (n=38) groups according to disease severity levels. The PAI-1 levels found were higher in the severe group (p<0.001) than in the non-severe group. In the regression analysis that followed, high sensitive troponin I and PAI-1 were found to indicate disease severity levels. The CT-SS was estimated as significantly higher in the non-survivor group compared to the survivor group (p<0.001). When comparing CT-SS between the severe group and the non-severe group, this was significantly higher in the severe group (p<0.001). In addition, a strong statistically significant positive correlation was found between CT-SS and PAI-1 levels (r: 0.838, p<0.001).

CONCLUSION

Anticipating poor clinical outcomes in relation to COVID-19 is crucial. This study showed that PAI-1 levels could independently predict disease severity and mortality rates for patients with COVID-19.

Role of Oxidative Stress in Peyronie's Disease: Biochemical Evidence and Experiences of Treatment with Antioxidants

BACKGROUND

Peyronie's disease (PD) is a chronic inflammatory condition affecting adult males, involving the tunica albuginea of the corpora cavernosa of the penis. PD is frequently associated with penile pain, erectile dysfunction, and a secondary anxious-depressive state. The etiology of PD has not yet been completely elucidated, but local injury is generally recognized to be a triggering factor. It has also been widely proven that oxidative stress is an essential, decisive component in all inflammatory processes, whether acute or chronic. Current conservative medical treatment comprises oral substances, penile injections, and physical therapy.

AIM

This article intends to show how antioxidant therapy is able to interfere with the pathogenetic mechanisms of the disease.

METHOD

This article consists of a synthetic narrative review of the current scientific literature on antioxidant therapy for this disease.

RESULTS

The good results of the antioxidant treatment described above also prove that the doses used were adequate and the concentrations of the substances employed did not exceed the threshold at which they might have interacted negatively with the mechanisms of the redox regulation of tissue.

CONCLUSIONS

We believe new, randomized, controlled studies are needed to confirm the efficacy of treatment with antioxidants. However, we consider the experiences of antioxidant treatment which can already be found in the literature useful for the clinical practice of urologists in the treatment of this chronic inflammatory disease.

Epigenetic aging in Williams syndrome

BACKGROUND

Williams syndrome (WS) is a rare genetic disorder caused by a microdeletion at the 7q11.23 region and is characterized by diverse symptoms encompassing physical and cognitive features. WS was reported to be associated to altered DNA methylation (DNAm) patterns. However, due to the limited information from long-term studies, it remains unclear whether WS accelerates aging. Genome-wide DNAm profiles can serve as "epigenetic clocks" to help estimate biological aging along with age-related markers, such as plasma proteins and telomere length.

METHODS

We investigated GrimAge, DNAm-based telomere length (DNAmTL), and other epigenetic clocks in blood samples of 32 patients with WS and 32 healthy controls.

RESULTS

We observed a significant acceleration in GrimAge, DNAmTL, and other epigenetic clocks in patients with WS as compared with those of controls. In addition, several GrimAge components, such as adrenomedullin, growth differentiation factor-15, leptin and plasminogen activator inhibitor-1, were altered in patients with WS.

CONCLUSIONS

This study provides novel evidence supporting the hypothesis that WS may be associated to accelerated biological aging. A better understanding of the overall underlying biological effects of WS can provide new foundations for improved patient care; thus, long-term follow-up studies are still warranted.

Plasma biomarkers associated with survival and thrombosis in hospitalized COVID-19 patients

Severe coronavirus disease-19 (COVID-19) has been associated with fibrin-mediated hypercoagulability and thromboembolic complications. To evaluate potential biomarkers of coagulopathy and disease severity in COVID-19, we measured plasma levels of eight biomarkers potentially associated with coagulation, fibrinolysis, and platelet function in 43 controls and 63 COVID-19 patients, including 47 patients admitted to the intensive care unit (ICU) and 16 non-ICU patients. COVID-19 patients showed significantly elevated levels of fibrinogen, tissue plasminogen activator (t-PA), and its inhibitor plasminogen activation inhibitor 1 (PAI-1), as well as ST2 (the receptor for interleukin-33) and von Willebrand factor (vWF) compared to the control group. We found that higher levels of t-PA, ST2, and vWF at the time of admission were associated with lower survival rates, and that thrombotic events were more frequent in patients with initial higher levels of vWF. These results support a predictive role of specific biomarkers such as t-PA and vWF in the pathophysiology of COVID-19. The data provide support for the case that hypercoagulability in COVID-19 is fibrin-mediated, but also highlights the important role that vWF may play in the genesis of thromboses in the pathophysiology of COVID-19. Interventions designed to enhance fibrinolysis might prove to be useful adjuncts in the treatment of coagulopathy in a subset of COVID-19 patients.

Self-reported dietary omega-3 polyunsaturated fatty acids are associated with adipose tissue markers and glucose metabolism in apparently healthy subjects

BACKGROUND

Plasminogen activator inhibitor 1 (PAI-1) and resistin are associated with dysfunctional adipose tissue (AT)-related metabolic complications. The role of dietary eicosapentaenoic (EPA) and docosahexaenoic (DHA) fatty acids in this relationship is unknown.

AIM

To investigate the association of EPA and DHA with PAI-1 and resistin, as well as the role of this association on the glucose metabolism of apparently healthy subjects.

SUBJECTS AND METHODS

Thirty-six healthy individuals were included. Validated food frequency questionnaires were used to analyse dietary habits. Inflammatory and glucose metabolism markers were quantified. Subcutaneous AT samples were obtained, and adipocyte number, area, and macrophage content were assessed.

RESULTS

In 36 subjects aged 56 ± 8 years and with a body mass index of 26 ± 4 kg/m², _logEPA, and _logDHA showed significant association with _logresistin and a marginal association with PAI-1. Adipocyte number, area, and _lognumber of macrophages per adipocyte significantly correlated with PAI-1 but not with _logresistin. Although _logEPA and _logDHA were independently associated with _loginsulin, _loginsulin resistance, and C-Peptide, the addition of _logresistin, but not of PAI-1, into the multivariable model, abolished the associations.

CONCLUSIONS

EPA and DHA could modulate glucose metabolism across AT functional states. Our data indicate that this association is independent of other metabolic risk factors.

Diurnal Oscillations of Fibrinolytic Parameters in Patients with Acute Myocardial Infarction and Their Relation to Platelet Reactivity: Preliminary Insights

There is limited information about diurnal changes in fibrinolysis parameters after acute myocardial infarction (AMI) and their relationship with on-treatment platelet reactivity. The aim of this study was to assess tissue plasminogen activator (t-PA), plasminogen activator inhibitor type-1 (PAI-1), α2-antiplasmin (α2-AP) activity, and plasmin-antiplasmin (PAP) complexes in 30 AMI patients taking dual antiplatelet therapy (DAPT), i.e., acetylsalicylic acid and clopidogrel. Fibrinolytic parameters were assessed at four time points (6 a.m., 10 a.m., 2 p.m., and 7 p.m.) on the third day after AMI using immunoenzymatic methods. Moreover, platelet reactivity was measured using multiple-electrode aggregometry, to assess potential differences in fibrinolytic parameters in low/high on-aspirin platelet reactivity and low/high on-clopidogrel platelet reactivity subgroups of patients. We detected significant diurnal oscillations in t-PA and PAI-1 levels in the whole study group. However, PAP complexes and α2-AP activity were similar at the analyzed time points. Our study reveals a potential impact of DAPT on the time course of fibrinolytic parameters, especially regarding clopidogrel. We suggest the presence of diurnal variations in t-PA and PAI-1 concentrations in AMI patients, with the highest levels midmorning, regardless of platelet reactivity. Significantly elevated levels of PAI-1 during the evening hours in clopidogrel-resistant patients may increase the risk of thrombosis.

LDR-adapted liver-derived cytokines have potential to induce atherosclerosis

PURPOSE

Atherosclerosis is a lipid-driven chronic inflammatory disease that causes cardiovascular diseases (CVD). The association between radiation and atherosclerosis has already been demonstrated; however, the effects of low-dose radiation (LDR) exposure on atherosclerosis have not been reported. Our study aims to propose that LDR may cause atherosclerosis phenotypes by the upregulation of plasminogen activator inhibitor-1 (PAI-1) and downregulation of androgen receptor (AR), which are cytokines secreted from the liver.

METHODS

Low-density lipoprotein (LDL) receptor deficient (Ldlr^-/-) mice were irradiated at 50 mGy, 100 mGy, and 1000 mGy. LDR irradiated Ldlr^-/- mice serum was analyzed by cytokine array and proteomics with silver staining. Oil Red O staining and BODIPY staining were performed to determine lipid accumulation in Human umbilical vein endothelial cells (HUVECs). Foam cell formation and monocyte recruitment were assessed through co-culture system with HUVECs and THP-1 cells.

RESULTS

After irradiation with LDR (100 mGy) the mice showed atherosclerotic phenotypes and through analysis results, we selected regulated cytokines, PAI-1 and AR, and found that these were changed in the liver. LDR-regulated cytokines have the potential to be transported to endothelial cells and induce lipid accumulation, inflammation of monocytes, increased oxidized low-density lipoprotein (oxLDL) and foam cells formation, that were series of phenotypes lead to plaque formation in endothelial cells and induces atherosclerosis. As a further aspect of this study, testosterone undecanoate (TU) was found to pharmacologically inhibit a series of atherosclerotic phenotypes exhibited by LDR. This study suggests a role for PAI-1 and AR in regulating the development of atherosclerosis after LDR exposure. Targeting PAI-1 and AR could serve as an attractive strategy for the management of atherosclerosis following LDR exposure.

Influenza A(H1N1)pdm09 Virus Alters Expression of Endothelial Factors in Pulmonary Vascular Endothelium in Rats

Influenza virus infection may cause endothelial activation and dysfunction. However, it is still not known to what extent the influenza virus can dysregulate the expression of various endothelial proteins. The aim of the study is to identify the level of expression of endothelial nitric oxide synthase (eNOS), plasminogen activator inhibitor-1 (PAI-1), and tissue plasminogen activator (tPA) in the pulmonary vascular endothelium, as well as the concentration of PAI-1 and tPA in the blood plasma in Wistar rats. Animals were intranasally infected with rat-adapted influenza A(H1N1)pdm09 virus. The expression of eNOS, PAI-1 and tPA in the pulmonary vascular endothelium was determined by immunohistochemistry; the concentration of PAI-1 and tPA was analyzed by ELISA at 24 and 96 h post infection (hpi). Thus, the expression of eNOS in the pulmonary vascular endothelium decreased by 1.9-fold at 24 hpi and increased by 2-fold at 96 hpi. The expression of PAI-1 in the pulmonary vascular endothelium increased by 5.23-fold and 6.54-fold at 24 and 96 hpi, respectively. The concentration of PAI-1 in the blood plasma of the rats decreased by 3.84-fold at 96 hpi, but not at 24 hpi. The expression of tPA in the pulmonary vascular endothelium was increased 2.2-fold at 96 hpi. The obtained data indicate the development of endothelial dysfunction that is characterized by the dysregulation of endothelial protein expression in non-lethal and clinically non-severe experimental influenza virus infection.

The Impact of Insulin Resistance on Loss of Lung Function and Response to Treatment in Asthma

Rationale: The role of obesity-associated insulin resistance (IR) in airflow limitation in asthma is uncertain. Objectives: Using data in the Severe Asthma Research Program 3 (SARP-3), we evaluated relationships between homeostatic measure of IR (HOMA-IR), lung function (cross-sectional and longitudinal analyses), and treatment responses to bronchodilators and corticosteroids. Methods: HOMA-IR values were categorized as without (<3.0), moderate (3.0-5.0), or severe (>5.0). Lung function included FEV1 and FVC measured before and after treatment with inhaled albuterol and intramuscular triamcinolone acetonide and yearly for 5 years. Measurements and Main Results: Among 307 participants in SARP-3, 170 (55%) were obese and 140 (46%) had IR. Compared with patients without IR, those with IR had significantly lower values for FEV1 and FVC, and these lower values were not attributable to obesity effects. Compared with patients without IR, those with IR had lower FEV1 responses to β-adrenergic agonists and systemic corticosteroids. The annualized decline in FEV1 was significantly greater in patients with moderate IR (-41 ml/year) and severe IR (-32 ml/year,) than in patients without IR (-13 ml/year, P < 0.001 for both comparisons). Conclusions: IR is common in asthma and is associated with lower lung function, accelerated loss of lung function, and suboptimal lung function responses to bronchodilator and corticosteroid treatments. Clinical trials in patients with asthma and IR are needed to determine if improving IR might also improve lung function.

The Role of Selected Serpins in Gastrointestinal (GI) Malignancies

Gastrointestinal (GI) cancers, which are a diverse group of malignant diseases, represent a major healthcare problem around the world. Due to the lack of specific symptoms in the early stages as well as insufficient diagnostic possibilities, these malignancies occupy the leading position in the causes of death worldwide. The currently available tests have too many limitations to be part of routine diagnostics. Therefore, new potential biomarkers that could be used as diagnostic and prognostic factors for these cancers are still being sought. Among the proteins that might fit this role are serpins, which are serine protease inhibitors. Although the serpins themselves have been known for many years, they have recently become the centre of attention for many authors, especially due to the fact that a number of proteins in this family are involved in many stages of neoplasia formation, from angiogenesis through tumour growth to progression. Therefore, the aim of this review is to present the current knowledge about the significance of serpins in GI malignancies, especially their involvement in the development and progression of oesophageal, gastric, pancreatic and colorectal cancers. This review summarises and confirms the important roles of selected serpins in the pathogenesis of various GI cancers and also points to their promising roles as therapeutic targets. However, due to the relatively nonspecific nature of serpins, future research should be carried out to elucidate the mechanisms involved in tumour pathogenesis in more detail.

Dysregulated Hemostasis and Immunothrombosis in Cerebral Cavernous Malformations

Cerebral cavernous malformation (CCM) is a neurovascular disease that affects 0.5% of the general population. For a long time, CCM research focused on genetic mutations, endothelial junctions and proliferation, but recently, transcriptome and proteome studies have revealed that the hemostatic system and neuroinflammation play a crucial role in the development and severity of cavernomas, with some of these publications coming from our group. The aim of this review is to give an overview of the latest molecular insights into the interaction between CCM-deficient endothelial cells with blood components and the neurovascular unit. Specifically, we underscore how endothelial dysfunction can result in dysregulated hemostasis, bleeding, hypoxia and neurological symptoms. We conducted a thorough review of the literature and found a field that is increasingly poised to regard CCM as a hemostatic disease, which may have implications for therapy.

The severity and duration of Hypoglycemia affect platelet-derived protein responses in Caucasians

Objective

Severe hypoglycemia is associated with increased cardiovascular death risk, and platelet responses to hypoglycemia (hypo) have been described. However, the impact of deep transient hypo (deep-hypo) versus prolonged milder hypo (mild-hypo) on platelet response is unclear.

Research Design and methods

Two hypo studies were compared; firstly, mild-hypo in 18-subjects (10 type-2-diabetes (T2D), 8 controls), blood glucose to 2.8mmoL/L (50 mg/dL) for 1-hour; secondly deep-hypo in 46-subjects (23 T2D, 23 controls), blood glucose to < 2.2mmoL/L (< 40 mg/dL) transiently. Platelet-related protein (PRP) responses from baseline to after 1-hour of hypo (mild-hypo) or at deep-hypo were compared, and at 24-hours post-hypo. Slow Off-rate Modified Aptamer (SOMA)-scan plasma protein measurement was used to determine PRP changes for 13 PRPs.

Results

In controls, from baseline to hypo, differences were seen for four PRPs, three showing increased %change in deep-hypo (Plasminogen activator inhibitor-1(PAI-1), CD40 ligand (CD40LG) and Protein-S), one showing increased %change in mild-hypo (von Willebrand factor (vWF)); at 24-hours in controls, %change for Protein-S remained increased in deep-hypo, whilst % change for vWF and plasminogen were increased in mild-hypo. In T2D, from baseline to hypo, differences were seen for 4 PRPs, three showing increased %change in deep-hypo (PAI-1, platelet glycoprotein VI and Tissue factor), one showing increased %change in mild-hypo (CD40LG); at 24-hours in T2D, %change for CD40LG remained increased, together with vWF, in deep-hypo.

Conclusion

Both mild-hypo and deep-hypo showed marked PRP changes that continued up to 24-hours, showing that both the severity and duration of hypoglycemia are likely important and that any degree of hypoglycemia may be detrimental for increased cardiovascular risk events through PRP changes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01639-w.

Platelets, Macrophages, and Thromboinflammation in Chagas Disease

Chagas disease (CD) is a major health problem in the Americas and an emerging health problem in Europe and other nonendemic countries. Several studies have documented persistence of the protozoan parasite Trypanosoma cruzi, and oxidative and inflammatory stress are major pathogenic factor. Mural and cardiac thrombi, cardiac arrhythmias, and cardiomyopathy are major clinical features of CD. During T. cruzi infection, parasite-released factors induce endothelial dysfunction along with platelet (PLT) and immune-cell activation. PLTs have a fundamental role in maintaining hemostasis and preventing bleeding after vascular injury. Excessive activation of PLTs and coagulation cascade can result in thrombosis and thromboembolic events, which are recognized to occur in seropositive individuals in early stages of CD when clinically symptomatic heart disease is not apparent. Several host and parasite factors have been identified to signal hypercoagulability and increase the risk of ischemic stroke in early phases of CD. Further, PLT interaction with immune cells and their role in host defense against pathogens and inflammatory processes have only recently been recognized and evolving. In the context of parasitic diseases, PLTs function in directly responding to T. cruzi infection, and PLT interactions with immune cells in shaping the proinflammatory or immunoregulatory function of monocytes, macrophages, and neutrophils remains elusive. How T. cruzi infection alters systemic microenvironment conditions to influence PLT and immune-cell interactions is not understood. In this review, we discuss the current literature, and extrapolate the mechanistic situations to explain how PLT and innate immune cell (especially monocytes and macrophages) interactions might be sustaining hypercoagulability and thromboinflammation in chronic CD.

Allopurinol and valproic acid improve cardiac triglyceride and Na+-K+-ATPase activity independent of circulating aldosterone in female rats with glucose intolerance

Context: Studies have shown that cardiac triglyceride accumulation and impaired Na⁺-K⁺-ATPase activity are linked to diabetes- related cardiovascular disease, particularly in women.Objectives: We hypothesised that allopurinol (ALL) and valproic acid (VPA) treatment would improve cardiac triglyceride and Na⁺-K⁺-ATPase activity independent of circulating aldosterone in Combined Oral Contraceptive (COC)-induced dysglycemiaMaterials and methods: Rats received COC (1.0 μg ethinylestradiol and 5.0 μg levonorgestrel; po) with or without ALL (1 mg; po) and VPA (20 mg; po) for 6 weeks.Results: COC-treatment led to impaired glucose tolerance, accumulated abdominal fat, dyslipidemia, elevated plasma MDA, PAI-1 and aldosterone levels and also reduced plasma nitric oxide bioavailability and cardiac Na⁺-K⁺-ATPase activity. However, either ALL or VPA treatment ameliorated these alterations comparably independent of elevated aldosterone levelDiscussion and conclusion: Our results suggest that either ALL or VPA would improve cardiac TG and Na⁺-K⁺-ATPase activity comparably in COC-treated rats, regardless of circulating aldosterone level.

Disengaging the COVID-19 Clutch as a Discerning Eye Over the Inflammatory Circuit During SARS-CoV-2 Infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes the cytokine release syndrome (CRS) and leads to multiorgan dysfunction. Mitochondrial dynamics are fundamental to protect against environmental insults, but they are highly susceptible to viral infections. Defective mitochondria are potential sources of reactive oxygen species (ROS). Infection with SARS-CoV-2 damages mitochondria, alters autophagy, reduces nitric oxide (NO), and increases both nicotinamide adenine dinucleotide phosphate oxidases (NOX) and ROS. Patients with coronavirus disease 2019 (COVID-19) exhibited activated toll-like receptors (TLRs) and the Nucleotide-binding and oligomerization domain (NOD-), leucine-rich repeat (LRR-), pyrin domain-containing protein 3 (NLRP3) inflammasome. The activation of TLRs and NLRP3 by SARS-CoV-2 induces interleukin 6 (IL-6), IL-1β, IL-18, and lactate dehydrogenase (LDH). Herein, we outline the inflammatory circuit of COVID-19 and what occurs behind the scene, the interplay of NOX/ROS and their role in hypoxia and thrombosis, and the important role of ROS scavengers to reduce COVID-19-related inflammation.

Plasminogen activator inhibitor 1 and gestational diabetes: the causal relationship

Plasminogen activator inhibitor 1 (PAI-1) also known as serpin E1 or endothelial plasminogen activator inhibitor, is produced from endothelial cells and adipose tissue. PAI-1 inhibits tissue plasminogen activator (tPA) and urokinase (uPA) preventing activation of plasminogen and fibrinolysis. Gestational diabetes mellitus (GDM) is defined as glucose intolerance and hyperglycemia during pregnancy. The underlying mechanism of GDM is due to the reduction of insulin secretion or the development of insulin resistance (IR). Normal PAI-1 is a crucial mediator for maintaining pregnancy, though aberrantly high PAI-1 promotes inflammation and thrombosis with increased risk of pregnancy loss. Increasing PAI-1 level had been shown to be an early feature of cardio-metabolic derangement in women with GDM. As well, GDM is regarded as an independent predictor for increasing PAI-1 levels compared to normal pregnancy. Taken together, GDM seems to be the causal factor in the increase of PAI-1 via induction of IR, hyperglycemia and hypertriglyceridemia. In conclusion, GDM triggers expression and release of PAI-1 which linked with GDM severity due to exaggerated pro-inflammatory and inflammatory cytokines with the development of IR. High PAI-1 levels in GDM may induce hypofibrinolysis and thrombotic complications.

Profiles of Plasminogen Activator Inhibitor-1 Levels in Healthcare Workers with Latent Tuberculosis and Non-Latent Tuberculosis Infections (Healthy Control)

Background: Mycobacterium tuberculosis infection causes the release of proinflammatory cytokines; interleukin IL-1, IL-6, and IL-8, as well as tumor necrosis factor (TNF-α), affecting hemostasis, namely an increase in procoagulation activity, a decrease in anticoagulant factors, and suppression of the fibrinolytic system that causes hypercoagulable states. Methods: This is a cross-sectional study that involves 80 healthcare workers. The study was conducted in two academic medical centers that were part of the healthcare system of Makassar city, South Sulawesi province, Indonesia, from September to October 2021. PAI-1 levels were measured using the enzyme-linked immunosorbent assay technique. The statistical test results were significant if the p values were <0.05. Results: Although there was no statistically significant difference (P > 0.05) in PAI-1 levels, PAI-1 level among participants in the LTBI group was found to be lower (4.9 ng/mL) than in the healthy control group (6.0 ng/mL). In addition, participants in the LTBI group with a history of being infected (9.6 ng/mL) with the COVID-19 had higher PAI-1 levels than those who had never been infected (2.3 ng/mL), which is statistically significant (P = 0.004). Although there was no statistically significant difference (P > 0.05) in PAI-1 levels among participants in the healthy control group, those with a history of being infected (6.7 ng/mL) demonstrated higher PAI-1 levels than those who had never been infected (4.8 ng/mL). Conclusions: PAI-1 levels were lower in LTBI participants than in healthy control participants, which potentially is due to more participants in the healthy control group having a history of COVID-19 infection.

Cerebral microvascular complications associated with SARS-CoV-2 infection: How did it occur and how should it be treated?

Cerebral microvascular disease has been reported as a central feature of the neurological disorders in patients with SARS-CoV-2 infection that may be associated with an increased risk of ischemic stroke. The main pathomechanism in the development of cerebrovascular injury due to SARS-CoV-2 infection can be a consequence of endothelial cell dysfunction as a structural part of the blood-brain barrier (BBB), which may be accompanied by increased inflammatory response and thrombocytopenia along with blood coagulation disorders. In this review, we described the properties of the BBB, the neurotropism behavior of SARS-CoV-2, and the possible mechanisms of damage to the CNS microvascular upon SARS-CoV-2 infection.

Endothelin-1 Stimulates PAI-1 Protein Expression via Dual Transactivation Pathway Dependent ROCK and Phosphorylation of Smad2L

<strong>Objective:</strong> In addition to the carboxy region, Smad2 transcription factor can be phosphorylated in the linker region as<br />well. Phosphorylation of Smad2 linker region (Smad2L) promotes the expression of plasminogen activator inhibitor type<br />1 (PAI-1) which leads to cardiovascular disorders such as atherosclerosis. The purpose of this study was to evaluate the role of dual transactivation of EGF and TGF-β receptors in phosphorylation of Smad2L and protein expression of PAI-1 induced by endothelin-1 (ET-1) in bovine aortic endothelial cells (BAECs). In addition, as an intermediary of G protein-coupled receptor (GPCR) signaling, the functions of ROCK and PLC were investigated in dual transactivation pathways.<br /><strong>Materials and Methods:</strong> The experimental study is an in vitro study performed on BAECs. Proteins were investigated<br />by western blotting using protein-specific antibodies against phospho-Smad2 linker region residues (Ser245/250/255),<br />phospho-Smad2 carboxy residues (465/467), ERK1/(Thr202/Thr204), and PAI-1.<br /><strong>Results:</strong> TGF (2 ng/ml), EGF (100 ng/ml) and ET-1 (100 nM) induced the phosphorylation of Smad2L. This response was<br />blocked in the presence of AG1478 (EGFR antagonists), SB431542 (TGFR inhibitor), and Y27632 (Rho-associated protein kinase (ROCK antagonist). Moreover, ET-1-increased protein expression of PAI-1 was decreased in the presence of bosentan (ET receptor inhibitor), AG1478, SB431542, and Y27632.<br /><strong>Conclusion:</strong> The results indicated that ET-1 increases the phosphorylation of Smad2L and protein expression of PAI-1<br />via induced the transactivation pathways of EGFR and TGFR. This study is the first attempt to scrutinize the significant role of ROCK in the protein expression of PAI-1.

The Association of Acute Phase Proteins in Stress and Inflammation-Induced T2D

Acute phase proteins (APPs), such as plasminogen activator inhibitor-1 (PAI-1), serum amyloid A (SAA), and C-reactive protein (CRP), are elevated in type-2 diabetes (T2D) and are routinely used as biomarkers for this disease. These APPs are regulated by the peripheral mediators of stress (i.e., endogenous glucocorticoids (GCs)) and inflammation (i.e., pro-inflammatory cytokines), with both implicated in the development of insulin resistance, the main risk factor for the development of T2D. In this review we propose that APPs, PAI-1, SAA, and CRP, could be the causative rather than only a correlative link between the physiological elements of risk (stress and inflammation) and the development of insulin resistance.

Endothelial Cells and the Cerebral Circulation

Endothelial cells form the innermost layer of all blood vessels and are the only vascular component that remains throughout all vascular segments. The cerebral vasculature has several unique properties not found in the peripheral circulation; this requires that the cerebral endothelium be considered as a unique entity. Cerebral endothelial cells perform several functions vital for brain health. The cerebral vasculature is responsible for protecting the brain from external threats carried in the blood. The endothelial cells are central to this requirement as they form the basis of the blood-brain barrier. The endothelium also regulates fibrinolysis, thrombosis, platelet activation, vascular permeability, metabolism, catabolism, inflammation, and white cell trafficking. Endothelial cells regulate the changes in vascular structure caused by angiogenesis and artery remodeling. Further, the endothelium contributes to vascular tone, allowing proper perfusion of the brain which has high energy demands and no energy stores. In this article, we discuss the basic anatomy and physiology of the cerebral endothelium. Where appropriate, we discuss the detrimental effects of high blood pressure on the cerebral endothelium and the contribution of cerebrovascular disease endothelial dysfunction and dementia. © 2022 American Physiological Society. Compr Physiol 12:3449-3508, 2022.

A Vicious Cycle: In Severe and Critically Ill COVID-19 Patients

The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, is one of the fastest-evolving viral diseases that has instigated a worldwide pandemic. Severe inflammatory syndrome and venous thrombosis are commonly noted in COVID-19 patients with severe and critical illness, contributing to the poor prognosis. Interleukin (IL)-6, a major complex inflammatory cytokine, is an independent factor in predicting the severity of COVID-19 disease in patients. IL-6 and tumor necrosis factor (TNF)-α participate in COVID-19-induced cytokine storm, causing endothelial cell damage and upregulation of plasminogen activator inhibitor-1 (PAI-1) levels. In addition, IL-6 and PAI-1 form a vicious cycle of inflammation and thrombosis, which may contribute to the poor prognosis of patients with severe COVID-19. Targeted inhibition of IL-6 and PAI-1 signal transduction appears to improve treatment outcomes in severely and critically ill COVID-19 patients suffering from cytokine storms and venous thrombosis. Motivated by studies highlighting the relationship between inflammatory cytokines and thrombosis in viral immunology, we provide an overview of the immunothrombosis and immunoinflammation vicious loop between IL-6 and PAI-1. Our goal is that understanding this ferocious circle will benefit critically ill patients with COVID-19 worldwide.

Age-Related Increase of Collagen/Fibrin Deposition and High PAI-1 Production in Human Nasal Polyps

Objective: Our previous studies showed an age-related increased prevalence of nasal polyps (NP) and reduced production of S100A8/9 in elderly patients with chronic rhinosinusitis with NP (CRSwNP). In this study, we investigated an unbiased age-related gene expression profile in CRSwNP subjects and healthy controls, and further identified the differences in their tissue remodeling. Methods: Microarrays using NP and uncinate tissues from health controls (elderly, age ≥65 vs. non-elderly, age 18-49) were performed, and differentially regulated genes were analyzed. Quantitative real-time PCR (qPCR), Immunostaining, Periodic acid-Schiff (PAS), trichrome staining, Western blot, and ELISA were performed for further investigation. Results: Microarrays identified differentially expressed genes according to disease and age; 278 in NP vs. controls, 75 in non-elderly NP vs. non-elderly controls, and 32 in elderly NP vs. elderly controls. qPCR confirmed that the PLAT gene was downregulated and the SERPINB2 gene upregulated in NP vs. controls. The serous glandular cell-derived antimicrobial protein/peptide-related genes such as BPIFB3, BPIFB2, LPO, and MUC7 were remarkably reduced in NP, regardless of age. SERPINE1 gene (plasminogen activator inhibitor-1, PAI-1) expression was significantly increased in elderly NP versus elderly controls. IHC and western blot confirmed significantly decreased production of MUC7 and LPO in NP versus controls. There was a trend of age-related reduction of submucosal gland cells in normal controls. Trichrome and immunofluorescence staining demonstrated an age-related increase of collagen and fibrin deposition in NP, consistent with increased PAI-1 production. Conclusion: This study demonstrated age-related differential glandular remodeling patterns and fibrosis in NP and normal controls. PAI-1 expression was significantly increased in elderly NP versus elderly controls, suggesting PAI-1 as a potential treatment target in elderly NP.

Cardiovascular Biomarkers: Lessons of the Past and Prospects for the Future

Cardiovascular diseases (CVDs) are a major healthcare burden on the population worldwide. Early detection of this disease is important in prevention and treatment to minimise morbidity and mortality. Biomarkers are a critical tool to either diagnose, screen, or provide prognostic information for pathological conditions. This review discusses the historical cardiac biomarkers used to detect these conditions, discussing their application and their limitations. Identification of new biomarkers have since replaced these and are now in use in routine clinical practice, but still do not detect all disease. Future cardiac biomarkers are showing promise in early studies, but further studies are required to show their value in improving detection of CVD above the current biomarkers. Additionally, the analytical platforms that would allow them to be adopted in healthcare are yet to be established. There is also the need to identify whether these biomarkers can be used for diagnostic, prognostic, or screening purposes, which will impact their implementation in routine clinical practice.

PAI-1: A Major Player in the Vascular Dysfunction in Obstructive Sleep Apnea?

Obstructive sleep apnea is a chronic and prevalent condition that is associated with endothelial dysfunction, atherosclerosis, and imposes excess overall cardiovascular risk and mortality. Despite its high prevalence and the susceptibility of CVD patients to OSA-mediated stressors, OSA is still under-recognized and untreated in cardiovascular practice. Moreover, conventional OSA treatments have yielded either controversial or disappointing results in terms of protection against CVD, prompting the need for the identification of additional mechanisms and associated adjuvant therapies. Plasminogen activator inhibitor-1 (PAI-1), the primary inhibitor of tissue-type plasminogen activator (tPA) and urinary-type plasminogen activator (uPA), is a key regulator of fibrinolysis and cell migration. Indeed, elevated PAI-1 expression is associated with major cardiovascular adverse events that have been attributed to its antifibrinolytic activity. However, extensive evidence indicates that PAI-1 can induce endothelial dysfunction and atherosclerosis through complex interactions within the vasculature in an antifibrinolytic-independent matter. Elevated PAI-1 levels have been reported in OSA patients. However, the impact of PAI-1 on OSA-induced CVD has not been addressed to date. Here, we provide a comprehensive review on the mechanisms by which OSA and its most detrimental perturbation, intermittent hypoxia (IH), can enhance the transcription of PAI-1. We also propose causal pathways by which PAI-1 can promote atherosclerosis in OSA, thereby identifying PAI-1 as a potential therapeutic target in OSA-induced CVD.

Gene expression of fibrinolytic markers in coronary thrombi

BACKGROUND

The fibrinolytic system plays an important role in coronary artery atherothrombosis, and especially circulating plasminogen-activator inhibitor (PAI) type 1 (PAI-1) associates with increased mortality, infarct size and heart failure in patients with myocardial infarction (MI). In a cross-sectional study, we aimed to study whether genes encoding tissue plasminogen activator (tPA), urinary-type plasminogen activator (uPA), PAI-1 and PAI-2 are expressed in coronary thrombi from acute ST-elevation MI (STEMI) patients. Any relations to myocardial injury measured by peak troponin T, time from symptom onset to Percutaneous Coronary Intervention (PCI), and to different cell types present in the thrombi were also explored.

METHODS

Intracoronary thrombi were aspirated from 33 STEMI patients treated with primary PCI. The thrombi were snap-frozen for gene expression analyses, relatively quantified by RT PCR. Peripheral blood samples were drawn. Correlations were performed by Spearmans rho.

RESULTS

The genes were present in 74-94% of the thrombi. Median peak troponin T was 3434 μ/L and median ischemic time 152 min. There were no significant correlations between the measured genes and troponin T, or ischemic time. Genes encoding tPA, u-PA, PAI-1 and PAI-2 all correlated significantly to the presence of monocytes/macrophages (CD68) in the thrombi (p = 0.028, p < 0.001, p = 0.003, p < 0.001). PAI-1 and PAI-2 also correlated to endothelial cells (CD31) (p = 0.002, p = 0.016). uPA associated with neutrophil granulocytes (CD 66b) (p = 0.019).

CONCLUSION

Genes encoding tPA, uPA, PAI-1 and PAI-2 were highly expressed in human coronary thrombi from STEMI patients, indicating fibrinolytic regulators playing active roles in the thrombi, although not related to myocardial injury. All markers related to the presence of monocytes/macrophages, indicating connection to local inflammatory cells.

TRIAL REGISTRATION

The study is registered at clinicaltrials.gov with identification number NCT02746822 .

SERPINE1 rs6092 Variant Is Related to Plasma Coagulation Proteins in Patients with Severe COVID-19 from a Tertiary Care Hospital

An impaired coagulation process has been described in patients with severe or critical coronavirus disease (COVID-19). Nevertheless, the implication of coagulation-related genes has not been explored. We aimed to evaluate the impact of F5 rs6025 and SERPINE1 rs6092 on invasive mechanical ventilation (IMV) requirement and the levels of coagulation proteins among patients with severe COVID-19. Four-hundred fifty-five patients with severe COVID-19 were genotyped using TaqMan assays. Coagulation-related proteins (P-Selectin, D-dimer, P-selectin glycoprotein ligand-1, tissue plasminogen activator [tPA], plasminogen activator inhibitor-1, and Factor IX) were assessed by cytometric bead arrays in one- and two-time determinations. Accordingly, SERPINE1 rs6092, P-Selectin (GG 385 pg/mL vs. AG+AA 632 pg/mL, p = 0.0037), and tPA (GG 1858 pg/mL vs. AG+AA 2546 pg/mL, p = 0.0284) levels were different. Patients carrying the CT F5-rs6025 genotype exhibited lower levels of factor IX (CC 17,136 pg/mL vs. CT 10,247 pg/mL, p = 0.0355). Coagulation proteins were also different among IMV patients than non-IMV. PSGL-1 levels were significantly increased in the late stage of COVID-19 (>10 days). The frequencies of F5 rs6025 and SERPINE1 rs6092 variants were not different among IMV and non-IMV. The SERPINE1 rs6092 variant is related to the impaired coagulation process in patients with COVID-19 severe.

Effect of washed versus unwashed red blood cells on transfusion-related immune responses in preterm newborns

Objectives

Transfusion with washed packed red blood cells (PRBCs) may be associated with reduced transfusion‐related pro‐inflammatory cytokine production. This may be because of alterations in recipient immune responses.

Methods

This randomised trial evaluated the effect of transfusion with washed compared with unwashed PRBCs on pro‐inflammatory cytokines and endothelial activation in 154 preterm newborns born before 29 weeks’ gestation. Changes in plasma cytokines and measures of endothelial activation in recipient blood were analysed after each of the first three transfusions.

Results

By the third transfusion, infants receiving unwashed blood had an increase in IL‐17A (P = 0.04) and TNF (P = 0.007), whereas infants receiving washed blood had reductions in IL‐17A (P = 0.013), TNF (P = 0.048), IL‐6 (P = 0.001), IL‐8 (P = 0.037), IL‐12 (P = 0.001) and IFN‐γ (P = 0.001). The magnitude of the post‐transfusion increase in cytokines did not change between the first and third transfusions in the unwashed group but decreased in the washed group for IL‐12 (P = 0.001), IL‐17A (P = 0.01) and TNF (P = 0.03), with the difference between the groups reaching significance by the third transfusion (P < 0.001 for each cytokine).

Conclusion

The pro‐inflammatory immune response to transfusion in preterm infants can be modified when PRBCs are washed prior to transfusion. Further studies are required to determine whether the use of washed PRBCs for neonatal transfusion translates into reduced morbidity and mortality.

Genetic Polymorphisms in a Familial Hypercholesterolemia Population from North-Eastern Europe

(1) Background: Familial hypercholesterolemia (FH) is one of the most prevalent inherited metabolic disorders. The purpose of the study was to investigate the role in cardiovascular disease (CVD) of PAI-1, ACE, ApoB-100, MTHFR A1298C, and C677T. (2) Methods: From a group of 1499 patients, we included 52 patients diagnosed with FH phenotype and 17 patients in a control group. (3) Results: Most of the FH patients had multiple comorbidities compared to the control group, such as atherosclerosis (48.1% vs. 17.6%), atherosclerotic cardiovascular disease (ASCVD 32.7% vs. 11.8%), and metabolic syndrome (MetS, 40.4% vs. 11.8%). In total, 66.7% of the FH patients had PAI-1 4G/5G genotype and MetS. Between 4G/5G and 4G/4G, a statistically significant difference was observed (p = 0.013). FH patients with ApoB R3500Q polymorphism were correlated with ASCVD (p = 0.031). Both MTHFR C677T and A1298C polymorphisms had a significant correlation with gender, alcohol consumption, and smoking status. ACE polymorphism was associated with ATS in FH patients, statistically significant differences being observed between heterozygous and homozygous D genotype (p = 0.036) as well as between heterozygous and homozygous I genotype (p = 0.021). (4) Conclusions: A link between these polymorphisms was demonstrated in the FH group for ATS, ASCVD, and MetS.

Novel prognostic determinants of COVID-19-related mortality: A pilot study on severely-ill patients in Russia

COVID-19 pandemic has posed a severe healthcare challenge calling for an integrated approach in determining the clues for early non-invasive diagnostics of the potentially severe cases and efficient patient stratification. Here we analyze the clinical, laboratory and CT scan characteristics associated with high risk of COVID-19-related death outcome in the cohort of severely-ill patients in Russia. The data obtained reveal that elevated dead lymphocyte counts, decreased early apoptotic lymphocytes, decreased CD14+/HLA-Dr+ monocytes, increased expression of JNK in PBMCs, elevated IL-17 and decreased PAI-1 serum levels are associated with a high risk of COVID-19-related mortality thus suggesting them to be new prognostic factors. This set of determinants could be used as early predictors of potentially severe course of COVID-19 for trials of prevention or timely treatment.

Plasminogen activator inhibitor-1 mediate downregulation of adiponectin in type 2 diabetes patients with metabolic syndrome

•

Both Adiponectin and PAI-1 levels are associated with the Metabolic abnormalities.

•

This study demonstrates that subjects with MetS have low adiponectin and higher PAI-1 levels compare to non-MetS.

•

Higher PAI-1 levels are associated with higher odds of risk and prevalence of MetS.

•

Pharmacological targeting of PAI-1 is necessary for MetS management.

Introduction

Metabolic syndrome (MetS) is a multifactorial disease characterized by metabolic abnormalities. Plasminogen activator inhibitor-1(PAI-1) is a key factor of the fibrinolysis its expression is elevated in insulin resistance, obesity, and MetS. In addition, an adiponectin produced by adipocytes is also key factor in MetS. This study aimed to investigate the relationship between PAI-1, adiponectin levels in MetS.

Patients and Methods

A total of 379 subjects were analyse in this cross-sectional study. MetS was defined by NCEP ATP-III criteria. Anthropometric, fasting blood glucose, HbA1c, total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, PAI-1, and adiponectin were measured.

Results

PAI-1 levels were higher in MetS compared with non-MetS. In addition, adiponectin levels were significantly lower in MetS compared to non-MetS. Furthermore, increased level of PAI-1 corresponds with increase in prevalence of MetS. PAI-1 levels were significantly associated with MetS (OR = 2.51, CI = 1.23 – 5.14; p = 0.039).

Conclusion

PAI-1 increases the risk of MetS. PAI-1 and adiponectin regulation is useful in assesing the presence and severity of MetS. Further pharmacological targeting of PAI-1 studies are necessary for MetS management.

Characteristic of cardiovascular status and intracardiac hemodynamics in patients with multiple myeloma before the start of antitumor therapy

AIM

assessment of risk factors, cardiovascular status and intracardiac hemodynamics in patients with multiple myeloma before the start of specific antitumor therapy. Materials and methods: The study included 2 equal groups of patients: the first group - 25 patients with a newly diagnosed diagnosis of multiple myeloma (MM), the comparison group - 25 patients with proven cardiovascular diseases (CVD) (hypertension (HD) and coronary heart disease (CHD)). All patients included in the study underwent standard laboratory diagnostics, instrumental research methods (ECG, Echo-KG, 24-hour Holter monitoring); proven CVD risk factors were also evaluated. Results: When comparing the two groups, it was reliably shown that the state of CVD in patients with MM is comparable to that in patients with proven CVD. In patients from the main group, were revealed significant positive correlations of average strength between indicators of systemic inflammation, the lipid spectrum and intracardiac hemodynamics: between the levels of CRP and triglycerides (r=0,415, p&lt;0,05); between the values of CRP and LDL (r=0,345, p=0,09); CRP and LA volume (r=0,434, p&lt;0,05); CRP and final diastolic volume (r=0,30, p&lt;0,05). At the beginning, a high risk of developing CV- events in patients with MM may be due to cardiac remodeling associated with the activity of systemic inflammation.

CONCLUSION

in view the use of potentially cardiovasculartoxicity drugs for the treatment of multiple myeloma, the assessment of the CV status and consultation with a cardiologist/cardiologist with the selection of the necessary therapy should be obligatory step before starting specific treatment.

Rapid Regression of Carotid Artery Stenosis Shortly after Intensive Medical Therapy

Carotid artery stenosis (CAS) is mainly caused by atherosclerosis. Intensive medical therapy is effective in preventing stroke in CAS. To date, there has been no published report of rapid regression of CAS. A woman with untreated hyperlipidemia visited our emergency room with left hemiparesis. She exhibited facial palsy, left hemiparesis, and dysarthria immediately after the visit. Brain magnetic resonance (MR) diffusion-weighted imaging confirmed acute infarction in the right middle cerebral artery (MCA) territory due to severe stenosis of the right internal carotid artery (ICA), which was revealed by MR angiography and carotid duplex ultrasonography. The patient started intensive statin therapy and dual antiplatelet agent therapy. Carotid artery stenting was not performed until hospitalization day 16 due to pleural effusion. On day 16, digital subtraction angiography was performed, and spontaneous regression of severe stenosis was observed. Only mild stenosis with ulcerative plaque was evident. The rapid CAS regression in this case may be caused by M2 macrophage polarization as a result of intensive statin therapy. This rapid regression may also result from reduced foam cell formation by statin and aspirin and thereby increased endogenous thrombolysis. Our patient demonstrated the efficacy of short-term intensive statin and aspirin therapy on atherosclerosis with untreated hyperlipidemia.

Review of evidence implicating the plasminogen activator system in blood-brain barrier dysfunction associated with Alzheimer's disease

Elucidating the pathogenic mechanisms of Alzheimer’s disease (AD) to identify therapeutic targets has been the focus of many decades of research. While deposition of extracellular amyloid-beta plaques and intraneuronal neurofibrillary tangles of hyperphosphorylated tau have historically been the two characteristic hallmarks of AD pathology, therapeutic strategies targeting these proteinopathies have not been successful in the clinics. Neuroinflammation has been gaining more attention as a therapeutic target because increasing evidence implicates neuroinflammation as a key factor in the early onset of AD disease progression. The peripheral immune response has emerged as an important contributor to the chronic neuroinflammation associated with AD pathophysiology. In this context, the plasminogen activator system (PAS), also referred to as the vasculature’s fibrinolytic system, is emerging as a potential factor in AD pathogenesis. Evolving evidence suggests that the PAS plays a role in linking chronic peripheral inflammatory conditions to neuroinflammation in the brain. While the PAS is better known for its peripheral functions, components of the PAS are expressed in the brain and have been demonstrated to alter neuroinflammation and blood-brain barrier (BBB) permeation. Here, we review plasmin-dependent and -independent mechanisms by which the PAS modulates the BBB in AD pathogenesis and discuss therapeutic implications of these observations.