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Congenital heart disease (CHD) can be complicated by pulmonary arterial hypertension (PAH). Cardiopulmonary bypass (CPB) for corrective surgery may cause endothelial dysfunction, involving endothelin-1 (ET-1), circulating endothelial cells (CECs), and endothelial progenitor cells (EPCs). These markers can gauge disease severity, but their levels in children’s peripheral blood still lack consensus for prognostic value. The aim of our study was to investigate changes in ET-1, cytokines, and the absolute numbers (Ɲ) of CECs and EPCs in children 24 h before and 48 h after CPB surgery to identify high-risk patients of complications. A cohort of 56 children was included: 41 cases with CHD-PAH (22 with high pulmonary flow and 19 with low pulmonary flow) and 15 control cases. We observed that Ɲ-CECs increased in both CHD groups and that Ɲ-EPCs decreased in the immediate post-surgical period, and there was a strong negative correlation between ET-1 and CEC before surgery, along with significant changes in ET-1, IL8, IL6, and CEC levels. Our findings support the understanding of endothelial cell precursors’ role in endogenous repair and contribute to knowledge about endothelial dysfunction in CHD.

Abstract The cell surface serine protease Transmembrane Protease 2 (TMPRSS2) is required to cleave the spike protein of SARS-CoV-2 for viral entry into cells. We determined whether negatively-charged heparin enhanced TMPRSS2 inhibition by alpha-1-antitrypsin (AAT). TMPRSS2 activity was determined in HEK293T cells overexpressing TMPRSS2. We quantified infection of primary human airway epithelial cells (hAEc) with human coronavirus 229E (HCoV-229E) by immunostaining for the nucleocapsid protein and by the plaque assay. Detailed molecular modeling was undertaken with the heparin–TMPRSS2–AAT ternary complex. Enoxaparin enhanced AAT inhibition of both TMPRSS2 activity and infection of hAEc with HCoV-229E. Underlying these findings, detailed molecular modeling revealed that: (i) the reactive center loop of AAT adopts an inhibitory-competent conformation compared with the crystal structure of TMPRSS2 bound to an exogenous (nafamostat) or endogenous (HAI-2) TMPRSS2 inhibitor and (ii) negatively-charged heparin bridges adjacent electropositive patches at the TMPRSS2–AAT interface, neutralizing otherwise repulsive forces. In conclusion, enoxaparin enhances AAT inhibition of both TMPRSS2 and coronavirus infection. Such host-directed therapy is less likely to be affected by SARS-CoV-2 mutations. Furthermore, given the known anti-inflammatory activities of both AAT and heparin, this form of treatment may target both the virus and the excessive inflammatory consequences of severe COVID-19.

Congenital heart disease (CHD) can be complicated by pulmonary arterial hypertension (PAH). Cardiopulmonary bypass (CPB) for corrective surgery may cause endothelial dysfunction, involving endothelin-1 (ET-1), circulating endothelial cells (CECs), and endothelial progenitor cells (EPCs). These markers can gauge disease severity, but their levels in children's peripheral blood still lack consensus for prognostic value. The aim of our study was to investigate changes in ET-1, cytokines, and the absolute numbers (Ɲ) of CECs and EPCs in children 24 h before and 48 h after CPB surgery to identify high-risk patients of complications. A cohort of 56 children was included: 41 cases with CHD-PAH (22 with high pulmonary flow and 19 with low pulmonary flow) and 15 control cases. We observed that Ɲ-CECs increased in both CHD groups and that Ɲ-EPCs decreased in the immediate post-surgical period, and there was a strong negative correlation between ET-1 and CEC before surgery, along with significant changes in ET-1, IL8, IL6, and CEC levels. Our findings support the understanding of endothelial cell precursors' role in endogenous repair and contribute to knowledge about endothelial dysfunction in CHD. [ABSTRACT FROM AUTHOR]

Background: Numerous polymorphisms in candidate genes coding for haemostatic system proteins have been proposed as risk factors for thrombosis. Methods: We performed a case-control study of consecutive ischaemic stroke survivors aged ≤45 years, treated at our neurology department from 2006 to 2014. Polymerase chain reaction–restriction fragment length polymorphism identified the following polymorphisms: Thr325Ile and Ala147Thr in TAFI, 4 G/5 G in PAI-1, PLA1/A2 in platelet glycoprotein IIb/IIIa, Glu298Asp in eNOS, and C677 T in 5,10-MTHFR. A multivariate logistic regression analysis was performed to evaluate the independent risk of stroke. Results: 204 cases and 204 age- and sex-matched controls were included in the study. Clinical and genetic variables associated with ischaemic stroke were hypertension (P = .03), tobacco use (P = .02), and the polymorphisms Glu298Asp (genotype: P = .001, allele frequency: P = .001) and C677 T (genotype: P = .01); the Ala147Thr, Thr325IIe, 4 G/5 G, and PLA1/A2 mutations were not associated with ischaemic stroke. The 298Asp (P = .03) and T (P = .01) alleles, hypertension (P = .03), tobacco use (P = .01) and family history of stroke (P = .04) were identified as independent risk factors. Conclusion: The polymorphisms Glu298Asp and C677T, affecting the eNOS and 5,10-MTHFR enzymes, respectively, and smoking, hypertension, and family history of stroke were associated with ischaemic stroke in young Mexican patients; this was not the case for the Thr325Ile, Ala147Thr, 4 G/5 G, and PLA1/A2 polymorphisms of the genes coding for fibrinolytic proteins and platelet receptors. Resumen: Introducción: Diversos polimorfismos en genes candidatos que codifican proteínas del sistema hemostático se han propuesto como factores de riesgo para el desarrollo de trombosis. Métodos: Casos y controles, sobrevivientes de enfermedad vascular cerebral (EVC) isquémico idiopático ≤ 45 años de edad del servicio de Neurología incluidos de manera consecutiva del 2006 al 2014. Por PCR-RFLP se identificaron los polimorfismos: Thr325Ile y Ala147Thr del gen de TAFI, 4 G/5 G del gen de PAI-1, PLA1/A2 del gen de la glicoproteína plaquetaria IIb/IIIa, Glu298Asp del gen de eNOS, y C677 T del gen de la 5,10 MTHFR. Se realizó un análisis multivariado de regresión logística para calcular el riesgo independiente de EVC. Resultados: 204 casos y 204 controles pareados por edad y sexo. Se asoció al polimorfismo Glu298Asp (genotipo p=0.001 y frecuencia alélica p=0.001), C677 T (genotipo p=0.01), hipertensión (p=0.03) y tabaquismo (p=0.02) con la presencia de EVC isquémico, no así para los polimorfismos Ala147Thr, Thr325IIe, 4 G/5 G, y PLA1/A2. Se identificó como factor de riesgo independiente al alelo 298Asp (p = 0.03), T (p = 0.01), hipertensión (p = 0.03), tabaquismo (p = 0.01) y AHFEAT (p = 0.04). Conclusiones: Los polimorfismos Glu298Asp y C677 T de los genes que codifican a la enzima eNOS y 5,10 MTHFR, tabaquismo, hipertensión y AHFEAT, se asociaron a la presencia de EVC isquémico en jóvenes mexicanos, no así el Thr325Ile, Ala147Thr, 4 G/5 G, PLA1/A2 en genes que codifican proteínas del sistema de fibrinólisis y receptores plaquetarios.

The antiphospholipid syndrome (APS), a systemic autoimmune disease characterized by a hypercoagulability associated to vascular thrombosis and/or obstetric morbidity, is caused by the presence of antiphospholipid antibodies such as lupus anticoagulant, anti-β-2-glycoprotein 1, and/or anticardiolipin antibodies. In the obstetrical APS, antiphospholipid antibodies induce the production of proinflammatory cytokines and tissue factor by placental tissues and recruited neutrophils. Moreover, antiphospholipid antibodies activate the complement system which, in turn, induces a positive feedback leading to recruitment of neutrophils as well as activation of the placenta. Activation of these cells triggers myometrial contractions and cervical ripening provoking the induction of labor. In thrombotic and obstetrical APS, antiphospholipid antibodies activate endothelial cells, platelets, and neutrophils and they may alter the multimeric pattern and concentration of von Willebrand factor, increase the concentration of thrombospondin 1, reduce the inactivation of factor XI by antithrombin, increase the activation of factor XII, and reduce the activity of tissue plasminogen activator with the subsequent production of plasmin. All these effects result in less permeable clots, denser, thinner, and with more branched fibrin fibers which are more difficult to lysate. As a consequence, thrombosis, the defining clinical criterion of APS, complicates the clinical course of the patient.

Background: Hyperhomocysteinemia, a thrombotic risk factor, may have several causes. Among the genetic causes of hyperhomocysteinemia, there are polymorphisms in the enzymes methylenetetrahydrofolate reductase (C677T) and cystathionine β-synthase (C699T, C1080T, and 844ins68). Although the frequency of hyperhomocysteinemia in our country is high, there is no evidence about the frequencies of these polymorphisms. Methods: We analyzed 80 healthy individuals from several regions in our country. We evaluated the fasting and post-oral methionine load plasma Hcy and the genotypes in order to obtain the allele frequencies of the polymorphisms C677T of methylenetetrahydrofolate reductase and C699T, C1080T, and 844ins68 of the cystathionine β-synthase. Results: No individual had deficiency of folic acid, vitamins B12, or B6, but 80% had post-oral methionine load hyperhomocysteinemia. We found a significant increase in the Hcy plasma concentration associated with age and gender. Only the polymorphism C1080T was significantly associated with hyperhomocysteinemia. Conclusion: There is an association between fasting and post-oral methionine load plasma Hcy concentrations with the allelic frequencies of the polymorphisms C669T, 844ins68, and C1080T of the cystathionine β-synthase and C667T of the methylenetetrahydrofolate reductase in healthy Mexican individuals. As compared with individuals with normal fasting or post-oral methionine load Hcy plasma levels, only C1080T was significantly associated with hyperhomocysteinemia.

Atherothrombosis is the cornerstone of cardiovascular diseases and the primary cause of death worldwide. Genetic contribution to disturbances in lipid metabolism, coagulation, inflammation and oxidative stress increase the susceptibility to its development and progression. Given its multifactorial nature, the multiloci studies have been proposed as potential predictors of susceptibility. A cross-sectional study was conducted to explore the contribution of nine genes involved in oxidative stress, inflammatory and thrombotic processes in 204 subjects with atherothrombosis matched by age and gender with a healthy group (n = 204). To evaluate the possibility of spurious associations owing to the Mexican population genetic heterogeneity as well as its ancestral origins, 300 unrelated mestizo individuals and 329 Native Americans were also included. ALOX5, LPA, MMP9 and TPO gene polymorphisms, as well as their multiallelic combinations, were twice to four times more frequent in those individuals with clinical manifestations of atherothrombosis than in the healthy group. Once adjusting for population stratification was done, these differences remained. Our results add further evidence on the contribution of ALOX5, LPA, MMP9 and TPO polymorphisms to atherothrombosis development in the middle-aged group, emphasizing the multiethnic studies in search of gene risk polymorphisms.

SARS-CoV-2 contains certain molecules that are related to the presence of immunothrombosis. Here, we review the pathogen and damage-associated molecular patterns. We also study the imbalance of different molecules participating in immunothrombosis, such as tissue factor, factors of the contact system, histones, and the role of cells, such as endothelial cells, platelets, and neutrophil extracellular traps. Regarding the pathogenetic mechanism, we discuss clinical trials, case-control studies, comparative and translational studies, and observational studies of regulatory or inhibitory molecules, more specifically, extracellular DNA and RNA, histones, sensors for RNA and DNA, as well as heparin and heparinoids. Overall, it appears that a network of cells and molecules identified in this axis is simultaneously but differentially affecting patients at different stages of COVID-19, and this is characterized by endothelial damage, microthrombosis, and inflammation.

Venous thromboembolic disease (VTD) is a public health problem. We recently reported that endothelial colony-forming cells (ECFCs) derived from endothelial cells (EC) (ECFC-ECs) from patients with VTD have a dysfunctional state. For this study, we proposed that a dysfunctional status of these cells generates a reduction of its proliferative ability, which is also associated with senescence and reactive oxygen species (ROS).Human mononuclear cells (MNCs) were obtained from peripheral blood from 40 healthy human volunteers (controls) and 50 patients with VTD matched by age (20-50 years) and sex to obtain ECFCs. We assayed their proliferative ability with plasma of patients and controls and supernatants of cultures from ECFC-ECs, senescence-associated β-galactosidase (SA-β-gal), ROS, and expression of ephrin-B2/Eph-B4 receptor. Compared with cells from controls, cells from VTD patients showed an 8-fold increase of ECFCs that emerged 1 week earlier, reduced proliferation at long term (39%) and, in passages 4 and 10, a highly senescent rate (30±1.05% vs. 91.3±15.07%, respectively) with an increase of ROS and impaired expression of ephrin-B2/Eph-4 genes. Proliferation potential of cells from VTD patients was reduced in endothelial medium [1.4±0.22 doubling population (DP)], control plasma (1.18±0.31 DP), or plasma from VTD patients (1.65±0.27 DP).As compared with controls, ECFC-ECs from individuals with VTD have higher oxidative stress, proliferation stress, cellular senescence, and low proliferative potential. These findings suggest that patients with a history of VTD are ECFC-ECs dysfunctional that could be associated to permanent risk for new thrombotic events.

Activated protein C (APC) is generated from the cleavage of protein C by thrombin coupled to thrombomodulinand, subsequently, is released as protein C activation peptide (papC). The aim of this study was toevaluate the effect of papC on human dermal microvascular endothelial cells (HMEC-1), activated with 5 ng//mL TNF-a. Flow cytometry showed that papC inhibited the expression of VCAM-1 and ICAM-1, after activationwith TNF-a. Similarly, RT-PCR analysis revealed that 2 and 4 pM papC inhibited the expression of VCAM-1and IL-8 mRNA in TNF-a-treated HMEC-1. In addition, the expression of endothelial nitric oxide synthase(eNOS) increased in HMEC-1 treated with papC, compared to those without treatment. Furthermore, Jurkatcell adhesion to HMEC-1 induced by TNF-a was significantly inhibited after the addition of papC, compared toHMEC-1 without papC (p = 0.03). Finally, a control peptide analog to papC showed no effect on the expressionof ICAM and VCAM on the surface of HMEC-1. In conclusion, our results suggest that papC exerts antiinflammatoryeffects on endothelial cells.Activated protein C (APC) is generated from the cleavage of protein C by thrombin coupled to thrombomodulinand, subsequently, is released as protein C activation peptide (papC). The aim of this study was toevaluate the effect of papC on human dermal microvascular endothelial cells (HMEC-1), activated with 5 ng//mL TNF-a. Flow cytometry showed that papC inhibited the expression of VCAM-1 and ICAM-1, after activationwith TNF-a. Similarly, RT-PCR analysis revealed that 2 and 4 pM papC inhibited the expression of VCAM-1and IL-8 mRNA in TNF-a-treated HMEC-1. In addition, the expression of endothelial nitric oxide synthase(eNOS) increased in HMEC-1 treated with papC, compared to those without treatment. Furthermore, Jurkatcell adhesion to HMEC-1 induced by TNF-a was significantly inhibited after the addition of papC, compared toHMEC-1 without papC (p = 0.03). Finally, a control peptide analog to papC showed no effect on the expressionof ICAM and VCAM on the surface of HMEC-1. In conclusion, our results suggest that papC exerts antiinflammatoryeffects on endothelial cells.