Correction for Chaumorcel et al., "The Human Cytomegalovirus Protein TRS1 Inhibits Autophagy via Its Interaction with Beclin 1"

International audienceErratum for The human cytomegalovirus protein TRS1 inhibits autophagy via its interaction with Beclin 1. [J Virol. 2012

Disruption of the Phosphate Transporter Pit1 in Hepatocytes Improves Glucose Metabolism and Insulin Signaling by Modulating the USP7/IRS1 Interaction

International audienceThe liver plays a central role in whole-body lipid and glucose homeostasis. Increasing dietary fat intake results in increased hepatic fat deposition, which is associated with a risk for development of insulin resistance and type 2 diabetes. In this study, we demonstrate a role for the phosphate inorganic transporter 1 (PiT1/SLC20A1) in regulating metabolism. Specific knockout of Pit1 in hepatocytes significantly improved glucose tolerance and insulin sensitivity, enhanced insulin signaling, and decreased hepatic lipogenesis. We identified USP7 as a PiT1 binding partner and demonstrated that Pit1 deletion inhibited USP7/IRS1 dissociation upon insulin stimulation. This prevented IRS1 ubiquitination and its subsequent proteasomal degradation. As a consequence, delayed insulin negative feedback loop and sustained insulin signaling were observed. Moreover, PiT1-deficient mice were protected against high-fat-diet-induced obesity and diabetes. Our findings indicate that PiT1 has potential as a therapeutic target in the context of metabolic syndrome, obesity, and diabetes

Influence of metabolic syndrome and diabetes on progression of calcific aortic valve stenosis

Determinants of the progression of aortic stenosis (AS) remained unclear. Metabolic syndrome (MetS) and diabetes are suspected to play an active role but literature is scarce and results conflicting. We sought to assess their impact in an ongoing prospective cohort of asymptomatic patients with at least mild AS

SQSTM1/p62 regulates the expression of junctional proteins through epithelial-mesenchymal transition factors

<p>The epithelial to mesenchymal transition (EMT) is an essential process during development and during tumor progression. Here, we observed the accumulation of the selective autophagy receptor and signaling adaptor sequestosome-1 (SQSTM1/p62) during growth factor-induced EMT in immortalized and tumor-derived epithelial cell lines. Modulation of the p62 level regulated the expression of junctional proteins. This effect was dependent on the ubiquitin-associated domain of p62, which stabilized the TGFβ/Smad signaling co-activator Smad4 and the EMT transcription factor Twist. This study highlights a novel function of p62 in a major epithelial phenotypic alteration.</p

Haemodynamic and anatomic progression of aortic stenosis

Background : Aortic valve stenosis (AS) is a progressive disease, but the impact of baseline AS haemodynamic or anatomic severity on AS progression remains unclear. Methods : In 149 patients (104 mild AS, 36 moderate AS and 9 severe AS) enrolled in 2 ongoing prospective cohorts (COFRASA/GENERAC), we evaluated AS haemodynamic severity at baseline and yearly, thereafter, using echocardiography (mean pressure gradient (MPG)) and AS anatomic severity using CT (degree of aortic valve calcification (AVC)). Results : After a mean follow-up of 2.9±1.0 years, mean MGP increased from 22±11 to 30±16 mm Hg (+3±3 mm Hg/year), and mean AVC from 1108±891 to 1640±1251 AU (arbitrary units) (+188±176 AU/year). Progression of AS was strongly related to baseline haemodynamic severity (+2±3 mm Hg/year in mild AS, +4±3 mm Hg/year in moderate AS and +5±5 mm Hg/year in severe AS (p=0.01)), and baseline haemodynamic severity was an independent predictor of haemodynamic progression (p=0.0003). Annualised haemodynamic and anatomic progression rates were significantly correlated (r=0.55, p<0.0001), but AVC progression rate was also significantly associated with baseline haemodynamic severity (+141±133 AU/year in mild AS, +279±189 AU/year in moderate AS and +361±293 AU/year in severe AS, p<0.0001), and both baseline MPG and baseline AVC were independent determinants of AVC progression (p<0.0001). Conclusions : AS progressed faster with increasing haemodynamic or anatomic severity. Our results suggest that a medical strategy aimed at preventing AVC progression may be useful in all subsets of patients with AS including those with severe AS and support the recommended closer follow-up of patients with AS as AS severity increases

Impact of Fetuin-A on progression of calcific aortic valve stenosis - The COFRASA - GENERAC study

Aortic stenosis (AS) is an active disease, but the determinants of AS progression remain largely unknown. Low levels of Fetuin-A, a powerful inhibitor of ectopic calcification, have been linked to ectopic calcium tissue deposition but its role in AS progression has not been clearly evaluated