Platelets Endocytose Viral Particles and Are Activated via TLR (Toll-Like Receptor) Signaling.

OBJECTIVE: Thrombocytopenia is associated with many viral infections suggesting virions interact with and affect platelets. Consistently, viral particles are seen inside platelets, and platelet activation markers are detected in viremic patients. In this article, we sought mechanistic insights into these virion/platelet interactions by examining how platelets endocytose, traffic, and are activated by a model virion. Approach and Results: Using fluorescently tagged HIV-1 pseudovirions, 3-dimensional structured illumination microscopy, and transgenic mouse models, we probed the interactions between platelets and virions. Mouse platelets used known endocytic machinery, that is, dynamin, VAMP (vesicle-associated membrane protein)-3, and Arf6 (ADP-ribosylation factor 6), to take up and traffic HIV-1 pseudovirions. Endocytosed HIV-1 pseudovirions trafficked through early (Rab4+) and late endosomes (Rab7+), and then to an LC3+ (microtubule-associated protein 1A/1B-light chain 3) compartment. Incubation with virions induced IRAK4 (interleukin 1 receptor-associated kinase 4), Akt (protein kinase B), and IKK (IκB kinase) activation, granule secretion, and platelet-leukocyte aggregate formation. This activation required TLRs (Toll-like receptors) and MyD88 (myeloid differentiation primary response protein 88) but was less extensive and slower than activation with thrombin. In vivo, HIV-1 pseudovirions injection led to virion uptake and platelet activation, as measured by IKK activation, platelet-leukocyte aggregate formation, and mild thrombocytopenia. All were decreased in VAMP-3-/- and, megakaryocyte/platelet-specific, Arf6-/- mice. Similar platelet activation profiles (increased platelet-leukocyte aggregates, plasma platelet factor 4, and phospho-IκBα) were detected in newly diagnosed and antiretroviral therapy-controlled HIV-1+ patients. CONCLUSIONS: Collectively, our data provide mechanistic insights into the cell biology of how platelets endocytose and process virions. We propose a mechanism by which platelets sample the circulation and respond to potential pathogens that they take up.

A successful treatment of tadalafil in incontinentia pigmenti with pulmonary hypertension.

We describe a female infant with incontinentia pigmenti complicated by severe pulmonary arterial hypertension that was markedly improved by tadalafil administration. The infant was referred to our institution because of neonatal seizures and generalized skin rash at the age of 1 day. She was diagnosed with incontinentia pigmenti on skin biopsy findings. In addition to incontinentia pigmenti, she had pulmonary arterial hypertension without structural heart disease. The pulmonary hypertension rapidly worsened at the age of 2 months and was confirmed by cardiac catheterization. The pulmonary artery pressure was equal to systemic pressure but it decreased in response to nitric oxide inhalation. We, therefore, initiated treatment with tadalafil of 1 mg/kg/day. The follow-up cardiac catheterization performed at 9 months revealed dramatic improvement in the pulmonary artery pressure. An IKBKG mutation with deletion of exons 4-10 was detected in the blood of both the patient and her mother. Our experience indicates that tadalafil may be beneficial in treating pulmonary arterial hypertension associated with incontinentia pigmenti.

Increased Inflammatory Activity in Patients 3 Months after Myocardial Infarction with Nonobstructive Coronary Arteries.

BACKGROUND: Around 5%-10% of patients with myocardial infarction (MI) present with nonobstructive coronary arteries (MINOCA). We aimed to assess pathophysiological mechanisms in MINOCA by extensively evaluating cardiovascular biomarkers in the stable phase after an event, comparing MINOCA patients with cardiovascular healthy controls and MI patients with obstructive coronary artery disease (MI-CAD). METHODS: Ninety-one biomarkers were measured with a proximity extension assay 3 months after MI in 97 MINOCA patients, 97 age- and sex-matched MI-CAD patients, and 98 controls. Lasso analyses (penalized logistic regression models) and adjusted multiple linear regression models were used for statistical analyses. RESULTS: In the Lasso analysis (MINOCA vs MI-CAD), 8 biomarkers provided discriminatory value: P-selectin glycoprotein ligand 1, C-X-C motif chemokine 1, TNF-related activation-induced cytokine, and pappalysin-1 (PAPPA) with increasing probabilities of MINOCA, and tissue-type plasminogen activator, B-type natriuretic peptide, myeloperoxidase, and interleukin-1 receptor antagonist protein with increasing probabilities of MI-CAD. Comparing MINOCA vs controls, 7 biomarkers provided discriminatory value: N-terminal pro-B-type natriuretic peptide, renin, NF-κ-B essential modulator, PAPPA, interleukin-6, and soluble urokinase plasminogen activator surface receptor with increasing probabilities of MINOCA, and agouti-related protein with increasing probabilities of controls. Adjusted multiple linear regression analyses showed that group affiliation was associated with the concentrations of 7 of the 8 biomarkers in the comparison MINOCA vs MI-CAD and 5 of the 7 biomarkers in MINOCA vs controls. CONCLUSIONS: Three months after the MI, the biomarker concentrations indicated greater inflammatory activity in MINOCA patients than in both MI-CAD patients and healthy controls, and a varying degree of myocardial dysfunction among the 3 cohorts.

NF-κB1/IKKε Gene Expression and Clinical Activity in Patients With Rheumatoid Arthritis.

OBJECTIVE: Rheumatoid arthritis (RA) is a systemic and autoimmune disorder whose primary characteristic is the chronic inflammation of joints. The objective of this study was to evaluate whether there was an association between nuclear factor kappa beta1/IKK epsilon (NF-κB1/IKKε) gene expression and clinical activity in RA. METHODS: Sixty patients with RA were included in the study: 30 with clinical activity and 30 with clinical remission. NF-κB1/IKKε gene expression was performed by real-time quantitative polymerase chain reaction through relative quantification with Taqman probes. A ROC curve for NF-κB1 and IKKε was also constructed. RESULTS: There were significant differences in NF-κB1 and IKKε gene expression (P ≤ .001 and P ≤ .029, respectively) between RA patients with clinical activity and clinical remission. The multivariate lineal general model showed that the use of nonsteroidal anti-inflammatory drugs influenced the NF-κB1 (P = .046) and IKKε (P = .005) expression. The ROC curves for the event "clinical activity" showed the greater area under the curve for NF-κB1 (0.827, 95% CI 0.717-0.937), P ≤ .001. CONCLUSION: Although the use of NSAIDs influences the NF-κB1/IKKε pathway, the IKKε expression might be a useful laboratorial analysis to evaluate the RA clinical activity.

Expression of X-linked Toll-like receptor 4 signaling genes in female vs. male neonates.

BACKGROUND: Male neonates display poorer disease prognosis and outcomes compared with females. Immune genes which exhibit higher expression in umbilical cord blood (UCB) of females may contribute to the female immune advantage during infection and inflammation. The aim of this study was to quantify expression of Toll-like receptor (TLR) 4 signaling genes encoded on the X-chromosome in UCB from term female vs. male neonates. METHODS: UCB samples were collected from term neonates (n = 26) born by elective Caesarean section and whole blood was collected from adults (n = 20). Leukocyte RNA was isolated and used in quantitative PCR reactions for IκB kinase γ (IKKγ), Bruton's tyrosine kinase (BTK), and IL-1 receptor associated kinase (IRAK)1. IRAK1 protein was analyzed by Western blot and confocal microscopy. RESULTS: In neonates there was no significant difference in the relative expression of IKKγ or BTK mRNA between genders. IRAK1 gene and protein expression was significantly higher in female vs. male UCB, with increased cytosolic IRAK1 expression also evident in female UCB mononuclear cells. Adults had higher expression of all three genes compared with neonates. CONCLUSION: Increased expression of IRAK1 could be responsible, in part, for sex-specific responses to infection and subsequent immune advantage in female neonates.

The NF-kB regulates the SHP-1 expression in monocytes in congestive heart failure.

It has been shown that functional recovery of patients with acute congestive heart failure (ACHF) after treatment with conventional drugs (CD) is mediated by suppression of inflammation in peripheral blood mononuclear cells. Here, we analyzed gene expression profiles of monocytes from symptomatic ACHF patients (NYHA Class III-IV) before and after pharmacological treatment with CD. The treatment was associated with selective down-regulation of "TNFR signaling" and pro-inflammatory mediators CCL5, MIP-1α receptor, CD14, ITGAM, and significant up-regulation of "TNFR signaling" as evidenced by increase in anti-inflammatory factors including NF-kBIA, TNFAIP3 and SHP-1. In monocyte TNF-alpha-stimulated there is a down-regulation of the phosphatase SHP-1 which induces a significant activation of TAK-1/IKK/NF-kB signaling. These findings suggest that the therapeutic impact of CD treatment in symptomatic ACHF includes negative regulation of the NF-kB signaling in monocytes and the improvement of the SHP-1 activity.

An important role for A20-binding inhibitor of nuclear factor-kB-1 (ABIN1) in inflammation-mediated endothelial dysfunction: an in vivo study in ABIN1 (D485N) mice.

INTRODUCTION: The link between cardiovascular disease (CVD) and patients with chronic inflammation is not clearly understood. We examined a knock-in mouse expressing a poly-ubiquitin-binding-defective mutant of the protein ABIN1 (ABIN1(D485N)), which develops a systemic lupus erythematosus-like autoimmune disease because of the hyperactivation of IκB kinases (IκKs) and mitogen-activated protein kinases (MAPKs). These mice were used to determine the potential role of these signaling pathways in inflammation-mediated CVD development. METHODS: Laser Doppler imaging in combination with the iontophoresis of vasoactive chemicals were used to assess endothelium-dependent vasodilatation in vivo in ABIN1 (D485N)) mutant defective (n=29) and wild-type (WT) control (n=26) mice. Measurements were made at baseline, and animals were subdivided to receive either chow or a proatherogenic diet for 4 weeks, after which, follow-up assessments were made. Paired and unpaired t tests, and ANOVA with post hoc Bonferroni correction were used for statistical significance at P<0.05. RESULTS: Endothelium-dependent vasodilatation to acetylcholine was attenuated at 4 weeks in ABIN1(D485N)-chow-fed mice compared with age-matched WT-chow-fed mice (P<0.05). The magnitude of attenuation was similar to that observed in WT-cholesterol-fed animals (versus WT-chow, P<0.01). ABIN1(D485N)-cholesterol-fed mice had the poorest endothelium-dependent responses compared with other groups (P<0.001). ABIN1(D485N)-chow-fed mice had increased plasma interleukin-6 (IL-6) levels (versus WT-chow, P<0.001), and this was further elevated in ABIN1(D485N)-cholesterol-fed mice (versus ABIN1(D485N)-chow; P<0.05). IL-1α was significantly greater in all groups compared with WT-chow (P<0.01). ABIN1(D485N) mice showed significant cardiac hypertrophy (P<0.05). CONCLUSIONS: The ABIN(D485N) mice display endothelial dysfunction and cardiac hypertrophy, which is possibly mediated through IL-6 and, to a lesser degree, IL-1α. These results suggest that the ABIN1-mediated hyperactivation of IKKs and MAPKs might mediate chronic inflammation and CVD development.

Platelet IκB kinase-ß deficiency increases mouse arterial neointima formation via delayed glycoprotein Ibα shedding.

OBJECTIVE: On the luminal surface of injured arteries, platelet activation and leukocyte-platelet interactions are critical for the initiation and progression of arterial restenosis. The transcription factor nuclear factor-κB is a critical molecule in platelet activation. Here, we investigated the role of the platelet nuclear factor-κB pathway in forming arterial neointima after arterial injury. METHODS AND RESULTS: We performed carotid artery wire injuries in low-density lipoprotein receptor-deficient (LDLR(-/-)) mice with a platelet-specific deletion of IκB kinase-ß (IKKß) (IKKß(fl/fl)/PF4(cre)/LDLR(-/-)) and in control mice (IKKß(fl/fl)/LDLR(-/-)). The size of the arterial neointima was 61% larger in the IKKß(fl/fl)/PF4(cre)/LDLR(-/-) mice compared with the littermate control IKKß(fl/fl)/LDLR(-/-) mice. Compared with the control mice, the IKKß(fl/fl)/PF4(cre)/LDLR(-/-) mice exhibited more leukocyte adhesion at the injured area. The extent of glycoprotein Ibα shedding after platelet activation was compromised in the IKKß-deficient platelets. This effect was associated with a low level of the active form of A Disintegrin And Metalloproteinase 17, the key enzyme involved in mediating glycoprotein Ibα shedding in activated IKKß-deficient platelets. CONCLUSIONS: Platelet IKKß deficiency increases the formation of injury-induced arterial neointima formation. Thus, nuclear factor-κB-related inhibitors should be carefully evaluated for use in patients after an arterial intervention.

The postprandial inflammatory response after ingestion of heated oils in obese persons is reduced by the presence of phenol compounds.

SCOPE: Heating during the process of cooking alters the chemical properties of foods and may affect subsequent postprandial inflammation. We tested the effects of four meals rich in different oils subjected to heating on the postprandial inflammatory metabolism of peripheral blood mononuclear cells (PBMCs). METHODS AND RESULTS: Twenty obese participants received four breakfasts following a randomized crossover design, consisting of milk and muffins made with different oils (virgin olive oil (VOO), sunflower oil (SFO), and a mixture of seeds oil (SFO/canola oil) with added either dimethylpolysiloxane (SOD), or natural antioxidants from olive mill wastewater alperujo (phenols; SOP)), previously subjected to 20 heating cycles. Postprandial inflammatory status in PBMCs was assessed by the activation of nuclear NF-κB, the concentration in cytoplasm of the NF-κB inhibitor (IκB-α), the mRNA levels of NF-κB subunits and activators (p65, IKKß, and IKKα) and other inflammatory molecules (TNF-α, IL-1ß, IL-6, MIF, and JNK), and lipopolysaccharide (LPS) levels. VOO and SOP breakfasts reduced NF-κB activation, increased IκB-α, and decreased LPS plasma concentration. SFO increased IKKα, IKKß, p65, IL-1b, IL-6, MIF, and JNK mRNA levels, and plasma LPS. CONCLUSION: Oils rich in phenols, whether natural (VOO) or artificially added (SOP), reduce postprandial inflammation, compared with seed oil (sunflower).