Aortic stenting in the growing sheep causes aortic endothelial dysfunction but not hypertension: Clinical implications for coarctation repair

Stent implantation is the treatment of choice for adolescents and adults with aortic coarctation (CoAo). Despite excellent short-term results, 20%-40% of the patients develop arterial hypertension later in life, which was attributed to inappropriate response of the aortic baroreceptors to increased stiffness of the ascending aorta (ASAO), either congenital or induced by CoAo repair. In particular, it has been hypothesized that stent itself may cause or sustain hypertension. Therefore, we aimed to study the hemodynamic and structural impact following stent implantation in the normal aorta of a growing animal

Coherent phonons and the interplay between charge density wave and Mott phases in 1<i>T</i>-TaSe₂

1$T$-TaSe$_{2}$ is host to coexisting strongly-correlated phases including charge density waves (CDWs) and an unusual Mott transition at low temperature. Here, we investigate coherent phonon oscillations in 1$T$-TaSe$_{2}$ using a combination of time- and angle-resolved photoemission spectroscopy (TR-ARPES) and time-resolved reflectivity (TRR). Perturbation by a femtosecond laser pulse triggers a modulation of the valence band binding energy at the $\Gamma$-point, related to the Mott gap, that is consistent with the in-plane CDW amplitude mode frequency. By contrast, TRR measurements show a modulation of the differential reflectivity comprised of multiple frequencies belonging to the distorted CDW lattice modes. Comparison of the temperature dependence of coherent and spontaneous phonons across the CDW transition shows that the amplitude mode intensity is more easily suppressed during perturbation of the CDW state by the optical excitation compared to other modes. Our results clearly identify the relationship of the in-plane CDW amplitude mode with the Mott phase in 1$T$-TaSe$_{2}$ and highlight the importance of lattice degrees of freedom.Comment: 7 pages, 4 figures, supplemental materia

Daclatasvir plasma level and resistance selection in HIV patients with hepatitis C virus cirrhosis treated with daclatasvir, sofosbuvir, and ribavirin

ObjectivesEffective treatment with direct-acting antiviral drugs against hepatitis C virus (HCV) is a medical need in cirrhotic HIV–HCV co-infected patients.MethodsThis study investigated the plasma levels of daclatasvir (DCV) and ribavirin (RBV) in HIV–HCV co-infected subjects treated with DCV, sofosbuvir, and RBV. Drug concentrations were quantified using validated high-performance liquid chromatography methods with ultraviolet detection. The HCV non-structural protein 5A and non-structural protein 5B coding regions were analyzed by population-based sequencing.ResultsDCV was dosed at week 4 and at week 8 of treatment, and RBV at week 8. One patient had the lowest DCV level, corresponding to 32.7% of the overall median value of the other patients at week 4 and about 40% at week 8. The Y93H variant was detected in this subject at weeks 8, 16, and 20 of treatment, but not before treatment or at day 2, and the patient experienced virological failure. Another subject with the Y93H variant at baseline and appropriate DCV levels had HCV RNA <12 IU/ml at week 12 and undetectable at week 16.ConclusionsSub-optimal DCV drug levels allow the selection of resistance-associated variants and fail to contribute to antiviral activity. No definite reason for the low DCV level was found. Quantifying the drug is suggested in difficult-to-treat patients

Effetto delle microparticelle endoteliali sulla funzionalità endoteliale: ruolo di miR-126 e di GLP-1R

Introduction: Microparticles are membrane vesicles shed from the plasma membrane of endothelial cells generated in physiological and pathological conditions. Recent studies have shown that EMP may represent important transporters for cytokines, proteins and microRNA. The aim of this study was to investigate, in endothelial cells, the effect of microparticles (EMP) from HCAEC exposed to normal-glucose condition or to high-glucose con-dition (iEMP) on miR-126 expression, on cell proliferation and migration. Methods: EMP were generated from HCAEC exposed to basal medium without growth supplements for 24 h. Microparticles derived from glucose-trated HCAEC were defined as “injured” EMP (iEMP). HCAEC were in-cubated with EMP or iEMP for 24 h. Microarray analysis was performed by TaqMan microRNA Array. miR-126 expression was determined by qPCR Real-Time, SPRED-1 and GLP-1R protein expression by Western Blot. Cell proliferation was measured using xCELLigence system (Roche) and cell migration by Scratch Assay. Results: EMP promote cell proliferation and migration by delivering func-tional miR-126 into recipient cells. This leads to downregulation of target protein SPRED-1, a negative modulator of Ras/ERK pathway. iEMP, which contain a lower amount of miR-126 in comparison to EMP, reduce cell pro-liferation by repressing GLP-1R protein expression and by decreasing ERK pathway activation. Conclusion: This study demonstrates for the first time that endothelial func-tion may be improved by EMP through a release of miR-126 but not in the presence of iEMP. Therefore, EMP may represent a new opportunity to transfer a desired biological message into target cells as therapeutic tool in cardiovascular diseases.Introduzione: Le microparticelle (EMP) sono piccole vescicole liberate dalla superficie di membrana di cellule endoteliali in condizioni sia fisiolo-giche che patologiche. Recenti studi hanno messo in evidenza che le EMP rappresentano trasportatori di microRNA capaci di modulare la funzionalità endoteliale con meccanismi non ancora definiti. E’ noto che l’attività proli-ferativa delle cellule endoteliali viene regolata da recettori “accoppiati alla proteina G”, come il recettore GLP-1 (GLP1R).Obiettivo di questo studio è stato di verificare l’effetto delle microparticelle ottenute da cellule cresciute in condizioni di glucosio normale (EMP) o in condizioni di elevato glucosio (iEMP) sull’espressione di miR-126, sulla proliferazione e sulla migrazione cellulare e sulla espressione di GLP1R nelle cellule endoteliali. Metodi: Le EMP sono state generate incubando cellule endoteliali umane (HCAEC) per 24h in terreno privo di supplementi di crescita. Le iEMP sono state ottenute pre-stimolando le cellule con elevata concentrazione di gluco-sio (30mM) per 72h. In seguito, le cellule HCAEC sono state incubate con le EMP o con le iEMP per 24h. L’analisi di microarray è stata eseguita me-diante TaqMan® microRNA Array. L’espressione genica di miR-126 è stata determinata mediante qPCR Real Time e l’espressione proteica di GLP1R mediante Western Blot. L’effetto proliferativo di EMP, iEMP è stato valuta-to mediante xCELLigence System (Roche) e la migrazione mediante Scratch Assay. Risultati: Le EMP favoriscono la proliferazione e la migrazione cellulare mediante il trasferimento di miR-126; miR-126 riduce l’espressione di SPRED-1, proteina che regola negativamente la proliferazione cellulare attraverso l'inibizione della via Ras/ERK chinasi; le iEMP invece, hanno un ridotto contenuto di miR-126, attenuano la proliferazione e la migrazione delle cellule endoteliali; è ipotizzabile che tale meccanismo sia dovuto alla riduzione dell’espressione proteica del recettore GLP-1R. La riduzione dell’espressione di GLP-1R indotta da iEMP inibisce l’attivazione di ERK 1/2, direttamente coinvolta nella regolazione della proliferazione cellulare endoteliale. Conclusione: Questo studio dimostra per la prima volta che i microRNA presenti nelle microparticelle possono agire da mediatori di comunica-zione intercellulare in quanto possono essere trasferiti all’interno di cel-lule target per modularne diverse attività metaboliche, come la prolifera-zione e migrazione cellulare

G-Protein \u3b23-Subunit Gene C825T Polymorphism and Cardiovascular Risk: An Updated Review

Hypertension is a common disorder of multifactorial origin that constitutes a major risk factor for cardiovascular events such as stroke and myocardial infarction. The subunits of the heterotrimeric G proteins are attractive candidate gene products for susceptibility to hypertension, obesity and insulin resistance syndrome. A polymorphism (825C/T) in exon 10 of the GNB3 gene, encoding for the G\u3b23 subunit, has been described. The 825T allele is associated with alternative splicing of the gene and formation of a truncated but functionally active \u3b23 subunit. Many studies have investigated whether carriers of the 825T allele are at increased risk for hypertension, obesity, insulin-resistance and left ventricular hypertrophy with apparently conflicting results. The present review demonstrates that GNB3 825T allele is a useful genetic marker for better defining the risk profile of hypertensive patients, as it is associated with increased risk of stroke and myocardial infarction in longitudinal studies in Caucasians

Sirtuin 1 stabilization by HuR represses TNF-\u3b1 and glucose induced E-Selectin release and endothelial cell adhesiveness in vitro. Relevance to human metabolic syndrome.

Chronic inflammation and hyperglycemia, typical features of metabolic diseases, trigger endothelial damage and release of E-selectin, a marker of endothelial activation.Herein, we investigated molecular pathways involved in the regulation of endothelial cell activation induced by TNF-\u3b1 and high glucose. In cultured HUVECs, we studied the role of HuR, an ELAV family RNA-binding protein, and SIRT1 on E-Selectin release and cell adhesion at different glucose concentrations. HuR expression and binding to SIRT1 were also analysed ex-vivo in peripheral mononuclear cells (PBMCs) of subjects with and without metabolic syndrome (MS), by immunoprecipitation of the ribonucleoprotein complex. We found that SIRT1 overexpression prevented TNF\u3b1- and high glucose-dependent NF-kB-p65 acetylation, E-Selectin promoter activity, E-Selectin release and adhesion of THP-1 cells to HUVECs. The same was mimicked by HuR overexpression, which binds and stabilizes SIRT1 mRNA. Importantly, in PBMCs of individuals with the MS compared to those without, SIRT1 expression was lower, and the ability of HuR to bind SIRT1 mRNA was significantly reduced, while plasma E-selectin was increased. We conclude that post-transcriptional stabilization of SIRT1 by HuR represses inflammation- and hyperglycemia-induced E-Selectin release and endothelial cell activation. Therefore, increasing SIRT1 expression represents a strategy to counter the accelerated vascular disease in metabolic disorders

PAR-4/Ca2+-calpain pathway activation stimulates platelet-derived microparticles in hyperglycemic type 2 diabetes.

Abstract Background: Patients with type 2 diabetes (T2DM) have a prothrombotic state that needs to be fully clarifed; microparticles (MPs) have emerged as mediators and markers of this condition. Thus, we investigate, in vivo, in T2DM either with good (HbA1c 647.0%; GGC) or poor (HbA1c>7.0%; PGC) glycemic control, the circulating levels of MPs, and in vitro, the molecular pathways involved in the release of MPs from platelets (PMP) and tested their pro-infammatory efects on THP-1 transformed macrophages. Methods: In 59 T2DM, and 23 control subjects with normal glucose tolerance (NGT), circulating levels of CD62E+, CD62P+, CD142+, CD45+ MPs were determined by fow cytometry, while plasma levels of ICAM-1, VCAM-1, IL-6 by ELISA. In vitro, PMP release and activation of isolated platelets from GGC and PGC were investigated, along with their efect on IL-6 secretion in THP-1 transformed macrophages. Results: We found that MPs CD62P+ (PMP) and CD142+ (tissue factor-bearing MP) were signifcantly higher in PGC T2DM than GGC T2DM and NGT. Among MPs, PMP were also correlated with HbA1c and IL-6. In vitro, we showed that acute thrombin exposure stimulated a signifcantly higher PMP release in PGC T2DM than GGC T2DM through a more robust activation of PAR-4 receptor than PAR-1 receptor. Treatment with PAR-4 agonist induced an increased release of PMP in PGC with a Ca2+-calpain dependent mechanism since this efect was blunted by calpain inhibitor. Finally, the uptake of PMP derived from PAR-4 treated PGC platelets into THP-1 transformed macrophages promoted a marked increase of IL-6 release compared to PMP derived from GGC through the activation of the NF-kB pathway. Conclusions: These results identify PAR-4 as a mediator of platelet activation, microparticle release, and infammation, in poorly controlled T2D

Metformin improves putative longevity effectors in peripheral mononuclear cells from subjects with prediabetes. A randomized controlled trial.

Background and aims: Prediabetes increases cardiovascular risk and is associated with excess mortality. In preclinical models, metformin has been shown to exert anti-ageing effects. In this study, we sought to assess whether metformin modulates putative effector longevity programs in prediabetic subjects. Methods and results: In a randomized, single-blind, placebo-controlled trial, 38 prediabetic subjects received metformin (1500 mg/day) or placebo for 2 months. At baseline and after treatment, we collected anthropometric and metabolic parameters. Gene and protein levels of SIRT1, mTOR, p53, p66Shc, SIRT1 activity, AMPK activation, telomere length, and SIRT1 promoter chromatin accessibility were determined in peripheral blood mononuclear cells (PBMCs). Plasma N-glycans, non-invasive surrogate markers of ageing, were also analysed. Compared to baseline, metformin significantly improved metabolic parameters and insulin sensitivity, increased SIRT1 gene/protein expression and SIRT1 promoter chromatin accessibility, elevated mTOR gene expression with concomitant reduction in p70S6K phosphorylation in subjects' PBMCs, and modified the plasma N-glycan profile. Compared to placebo, metformin increased SIRT1 protein expression and reduced p70S6K phosphorylation (a proxy of mTOR activity). Plasma N-glycans were also favourably modified by metformin compared to placebo. Conclusion: In individuals with prediabetes, metformin ameliorated effector pathways that have been shown to regulate longevity in animal model