Publications by authors named "Thibault Barouillet"

Atherosclerotic cardiovascular diseases are the most frequent cause of death worldwide. The clinical complications of atherosclerosis are closely linked to the haematopoietic and immune systems, which maintain homeostatic functions and vital processes in the body. The nodes linking metabolism and inflammation are receiving increasing attention because they are inextricably linked to inflammatory manifestations of non-communicable diseases, including atherosclerosis.

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Metabolic dysregulation, including perturbed glutamine-glutamate homeostasis, is common among patients with cardiovascular diseases, but the underlying mechanisms remain largely unknown. Using the human MESA cohort, here we show that plasma glutamine-glutamate ratio is an independent risk factor for carotid plaque progression. Mice deficient in glutaminase-2 (Gls2), the enzyme that mediates hepatic glutaminolysis, developed accelerated atherosclerosis and susceptibility to catastrophic cardiac events, while Gls2 overexpression partially protected from disease progression.

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The prevalence of diabetes steadily increases worldwide mirroring the prevalence of obesity. Endoplasmic reticulum (ER) stress is activated in diabetes and contributes to β-cell dysfunction and apoptosis through the activation of a terminal unfolded protein response (UPR). Our results uncover a new role for Bax Inhibitor-One (BI-1), a negative regulator of inositol-requiring enzyme 1 (IRE1α) in preserving β-cell health against terminal UPR-induced apoptosis and pyroptosis in the context of supraphysiological loads of insulin production.

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Metastatic uveal melanomas are highly resistant to all existing treatments. To address this critical issue, we performed a kinome-wide CRISPR-Cas9 knockout screen, which revealed the LKB1-SIK2 module in restraining uveal melanoma tumorigenesis. Functionally, LKB1 loss enhances proliferation and survival through SIK2 inhibition and upregulation of the sodium/calcium (Na /Ca ) exchanger SLC8A1.

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Cholesterol efflux pathways could be exploited in tumor biology to unravel cancer vulnerabilities. A mouse model of lung-tumor-bearing KRAS mutation with specific disruption of cholesterol efflux pathways in epithelial progenitor cells promoted tumor growth. Defective cholesterol efflux in epithelial progenitor cells governed their transcriptional landscape to support their expansion and create a pro-tolerogenic tumor microenvironment (TME).

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Macrophages are pivotal in the initiation and development of atherosclerotic cardiovascular diseases. Recent studies have reinforced the importance of mitochondria in metabolic and signaling pathways to maintain macrophage effector functions. In this review, we discuss the past and emerging roles of macrophage mitochondria metabolic diversity in atherosclerosis and the potential avenue as biomarker.

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Rationale: Macrophages face a substantial amount of cholesterol after the ingestion of apoptotic cells, and the LIPA (lysosomal acid lipase) has a major role in hydrolyzing cholesteryl esters in the endocytic compartment.

Objective: Here, we directly investigated the role of LIPA-mediated clearance of apoptotic cells both in vitro and in vivo.

Methods And Results: We show that LIPA inhibition causes a defective efferocytic response because of impaired generation of 25-hydroxycholesterol and 27-hydroxycholesterol.

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This paper reports: (i) the facile synthesis of a cysteine synthon incorporating both a fluorescent group and a triphenylphosphonium derivative (TBTP) via the formation of a disulphide bond, which can subsequently undergo facile intracellular scission, (ii) the direct conjugation of this synthon to a non-permeable drug, (a cyclic PNA (peptide nucleic acid)-based compound has been chosen as a model), and (iii) that this conjugation enables the efficient homogenous delivery of the otherwise non-permeable cyclic PNA into the cytoplasm of cells, as demonstrated by fluorescence microscopy. Our results indicate that this fluorescent-labelled cysteine-TBTP synthon can provide a very useful tool for exploring the cellular uptake of a large range of molecules of biological interest, containing only a single reactive function. The preparation of an activated TBTP derivative is also described and this procedure could be widely used to introduce a TBTP cation to any thio-containing molecule.

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A cyclic hexameric PNA-based compound labeled with fluorescein has been prepared following the liquid phase FPB strategy. Its cellular uptake, without and with electroporation, has been investigated by fluorescence microscopy.

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