An obesogenic diet increases atherosclerosis through promoting microbiota dysbiosis-induced gut lymphocyte trafficking into the periphery.

Although high-fat diet (HFD)-induced gut microbiota dysbiosis is known to affect atherosclerosis, the underlying mechanisms remain to be fully explored. Here, we show that the progression of atherosclerosis depends on a gut microbiota shaped by an HFD but not a high-cholesterol (HC) diet and, more particularly, on low fiber (LF) intake. Mechanistically, gut lymphoid cells impacted by HFD- or LF-induced microbiota dysbiosis highly proliferate in mesenteric lymph nodes (MLNs) and migrate from MLNs to the periphery, which fuels T cell accumulation within atherosclerotic plaques. This is associated with the induction of mucosal addressin cell adhesion molecule 1 (MAdCAM-1) within plaques and the presence of enterotropic lymphocytes expressing ß7 integrin. MLN resection or lymphocyte deficiency abrogates the pro-atherogenic effects of a microbiota shaped by LF. Our study shows a pathological link between a diet-shaped microbiota, gut immune cells, and atherosclerosis, suggesting that a diet-modulated microbiome might be a suitable therapeutic target to prevent atherosclerosis.

In vitro Raman imaging of human macrophages: Impact of eicosapentaenoic acid on the hydrolysis of cholesterol esters in lipid droplets.

Atherosclerosis - a cardiovascular disease and the primary cause of morbidity and mortality in industrialized countries - is linked to the existence of atherosclerotic plaques characterized by cholesterol-laden macrophages called foam cells. In these cells, cholesterol esters associated with triglycerides form lipid droplets (LD). The only way to remove this excess cholesterol is to promote free cholesterol efflux from macrophages to specific acceptors. It has been shown recently that eicosapentaenoic acid (EPA) reduces efflux on cholesterol-loaded THP-1 macrophages in vitro due to decreased cholesterol esters hydrolysis. These in vitro observations could reflect EPA's difficulty in facilitating in vivo the antiatherogenic process of cholesterol efflux within advanced atherosclerotic plaques. This work aims to study in vitro the impact of EPA on cholesterol esters hydrolysis in the LD of human THP-1 macrophages using vibrational Raman microspectroscopy. For this, we used deuterated EPA and recorded spectral images at the cell scale after different hydrolysis times. RESULTS: showed that EPA is involved in forming triglycerides and phospholipids of LD. Hydrolysis kinetics slowed down after 24 h, triglycerides increased, and the intensity of the characteristic bands linked to deuteration decreased. The size of LD without hydrolysis (H0) is higher than that after 24 h (H1) or 48 h (H2) of hydrolysis. The size decrease is sharper when going from H0 to H1 than from H1 to H2. Principal component analysis illustrated data' projection according to the cellular compartment, the hydrolysis time, and the supplementation of the medium.

Association of Lipoprotein(a) Levels With Incidence of Major Adverse Limb Events.

Importance: High lipoprotein(a) (Lp[a]) levels are involved in the development of cardiovascular events, particularly in myocardial infarction, stroke, and peripheral artery disease. Studies assessing the Lp(a) levels associated with adverse lower-limb events are lacking. Objective: To assess the association between Lp(a) levels and incidence of major adverse limb events in unselected hospitalized patients. Design, Setting, and Participants: This large retrospective monocentric cohort study was conducted from January 1, 2000, to December 31, 2020. Data were derived from the clinical information system of the Hôpital Européen Georges-Pompidou, a Paris-based university hospital. Patients who underwent at least 1 Lp(a) measurement at the center during the study period were included. Patients who had no follow-up data or who had the first Lp(a) measurement after the study outcome had occurred were excluded. Data analyses were performed from May 2021 to January 2022. Main Outcomes and Measures: The primary outcome was the first inpatient major adverse limb event, defined as a major amputation, peripheral endovascular revascularization, or peripheral surgical revascularization, during follow-up. Secondary outcomes included individual components of the primary outcome. Lipoprotein(a) levels were categorized as follows: normal (<50 mg/dL), high (50 to <134 mg/dL), and very high (≥134 mg/dL); to convert Lp(a) values to milligrams per liter, multiply by 0.1. Results: A total of 16 513 patients (median [IQR] age, 58.2 [49.0-66.7] years; 9774 men [59.2%]) were included in the cohort. The median (IQR) Lp(a) level was 24 (10.0-60.0) mg/dL. The 1-year incidence of major adverse limb event was 2.44% in the overall population and 4.54% among patients with very high Lp(a) levels. High (adjusted accelerated failure time [AFT] exponential estimate: 0.43; 95% CI, 0.24-0.78; Benjamini-Hochberg-corrected P = .01) and very high (adjusted AFT exponential estimate: 0.17; 95% CI, 0.07-0.40; Benjamini-Hochberg-corrected P < .001) Lp(a) levels were independently associated with an increased risk of major adverse limb event. Conclusions and Relevance: Results of this study showed that higher Lp(a) levels were independently associated with an increased risk of a major adverse limb event in hospitalized patients. The Lp(a) measurement needs to be taken into account to improve lower-limb vascular risk assessment.

Homocysteine Metabolism Pathway Is Involved in the Control of Glucose Homeostasis: A Cystathionine Beta Synthase Deficiency Study in Mouse.

Cystathionine beta synthase (CBS) catalyzes the first step of the transsulfuration pathway from homocysteine to cystathionine, and its deficiency leads to hyperhomocysteinemia (HHcy) in humans and rodents. To date, scarce information is available about the HHcy effect on insulin secretion, and the link between CBS activity and the setting of type 2 diabetes is still unknown. We aimed to decipher the consequences of an inborn defect in CBS on glucose homeostasis in mice. We used a mouse model heterozygous for CBS (CBS+/-) that presented a mild HHcy. Other groups were supplemented with methionine in drinking water to increase the mild to intermediate HHcy, and were submitted to a high-fat diet (HFD). We measured the food intake, body weight gain, body composition, glucose homeostasis, plasma homocysteine level, and CBS activity. We evidenced a defect in the stimulated insulin secretion in CBS+/- mice with mild and intermediate HHcy, while mice with intermediate HHcy under HFD presented an improvement in insulin sensitivity that compensated for the decreased insulin secretion and permitted them to maintain a glucose tolerance similar to the CBS+/+ mice. Islets isolated from CBS+/- mice maintained their ability to respond to the elevated glucose levels, and we showed that a lower parasympathetic tone could, at least in part, be responsible for the insulin secretion defect. Our results emphasize the important role of Hcy metabolic enzymes in insulin secretion and overall glucose homeostasis.

Gemcitabine lipid prodrug nanoparticles: Switching the lipid moiety and changing the fate in the bloodstream.

A simple approach to achieve a lipoprotein (LP)-mediated drug delivery is to trigger the spontaneous drug insertion into endogenous lipoproteins in the bloodstream, by means of its chemical modification. Nanoparticles (NPs) made of the squalene-gemcitabine (SQGem) conjugate were found to have a high affinity for plasma lipoproteins while free gemcitabine did not, suggesting a key role of the lipid moiety in this event. Whether the drug conjugation to cholesterol, one of the major lipoprotein-transported lipids, could also promote an analogous interaction was a matter of question. NPs made of the cholesterol-gemcitabine conjugate (CholGem) have been herein thoroughly investigated for their blood distribution profile both in vitro and in vivo. Unexpectedly, contrarily to SQGem, no trace of the CholGem prodrug could be found in the lipoprotein fractions, nor was it interacting with albumin. The investigation of isolated NPs and NPs/LPs physical mixtures provided a further insight into the lack of interaction of CholGem NPs with LPs. Although essential for allowing the self-assembly of the prodrug into nanoparticles, the lipid moiety may not be sufficient to elicit interaction of the conjugated drug with plasma lipoproteins but the whole NP physicochemical features must be carefully considered.

Eicosapentaenoic acid membrane incorporation stimulates ABCA1-mediated cholesterol efflux from human THP-1 macrophages.

A high intake in polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) (C20:5 n-3), is cardioprotective. Dietary PUFAs incorporate into membrane phospholipids, which may modify the function of membrane proteins. We investigated the consequences of the membrane incorporation of several PUFAs on the key antiatherogenic ABCA1-mediated cholesterol efflux pathway. Human THP-1 macrophages were incubated with EPA, arachidonic acid (AA) (C20:4 n-6) or docosahexaenoic acid (DHA) (C22:6 n-3) for a long time to mimic a chronic exposure. EPA 70 µM, but not AA 50 µM or DHA 15 µM, increased ABCA1-mediated cholesterol efflux to apolipoprotein (apo) AI by 28% without altering aqueous diffusion. No variation in ABCA1 expression or localization was observed after EPA treatment. EPA incorporation did not affect the phenotype of THP-1 macrophages. The membrane phospholipids composition of EPA cells displayed higher levels of both EPA and its elongation product docosapentaenoic acid, which was associated with drastic lower levels of AA. Treatment by EPA increased the ATPase activity of the transporter, likely through a PKA-dependent mechanism. Eicosanoids were not involved in the stimulated ABCA1-mediated cholesterol efflux from EPA-enriched macrophages. In addition, EPA supplementation increased the apo AI binding capacity from macrophages by 38%. Moreover, the increased apo AI binding in EPA-enriched macrophages can be competed. In conclusion, EPA membrane incorporation increased ABCA1 functionality in cholesterol-normal human THP-1 macrophages, likely through a combination of different mechanisms. This beneficial in vitro effect may partly contribute to the cardioprotective effect of a diet enriched with EPA highlighted by several recent clinical trials.

Aldosterone-Related Myocardial Extracellular Matrix Expansion in Hypertension in Humans: A Proof-of-Concept Study by Cardiac Magnetic Resonance.

OBJECTIVES: This study sought to assess the respective effects of aldosterone and blood pressure (BP) levels on myocardial fibrosis in humans. BACKGROUND: Experimentally, aldosterone promotes left ventricular (LV) hypertrophy, and interstitial myocardial fibrosis in the presence of high salt intake. METHODS: The study included 20 patients with primary aldosteronism (PA) (high aldosterone and high BP), 20 patients with essential hypertension (HTN) (average aldosterone and high BP), 20 patients with secondary aldosteronism due to Bartter/Gitelman (BG) syndrome (high aldosterone and normal BP), and 20 healthy subjects (HS) (normal aldosterone and normal BP). Participants in each group were of similar age and sex distributions, and asymptomatic. Cardiac magnetic resonance including cine and T1 mapping was performed blind to the study group to quantify global LV mass index, as well as intracellular mass index and extracellular mass index considered as a measure of myocardial fibrosis in vivo. RESULTS: Median plasma aldosterone concentration was as follows: PA = 709 pmol/l (interquartile range [IQR]: 430 to 918 pmol/l); HTN = 197 pmol/l (IQR: 121 to 345 pmol/l); BG = 297 pmol/l (IQR: 180 to 428 pmol/l); and HS = 105 pmol/l (IQR: 85 to 227 pmol/l). Systolic BP was as follows: PA = 147 ± 15 mm Hg; HTN = 133 ± 19 mm Hg; BG = 116 ± 9 mm Hg; and HS = 117 ± 12 mm Hg. LV end-diastolic volume showed underloading in BG and overloading in patients with PA (63 ± 13 ml/m2 vs. 82 ± 15 ml/m2; p < 0.0001). Intracellular mass index increased with BP across groups (BG: 36 [IQR: 29 to 41]; HS: 40 [IQR: 36 to 46]; HTN: 51 [IQR: 42 to 54]; PA: 50 [IQR: 46 to 67]; p < 0.0001). Extracellular mass index was similar in BG, HS, and HTN (16 [IQR: 12 to 20]; 15 [IQR: 11 to 18]; and 14 [IQR: 12 to 17], respectively) but 30% higher in PA (21 [IQR: 18 to 29]; p < 0.0001) remaining significant after adjustment for mean BP. CONCLUSIONS: Only primary pathological aldosterone excess combined with high BP increased both extracellular myocardial matrix and intracellular mass. Secondary aldosterone excess with normal BP did not affect extracellular myocardial matrix. (Study of Myocardial Interstitial Fibrosis in Hyperaldosteronism; NCT02938910).

Molecular Rescue of Dyrk1A Overexpression Alterations in Mice with Fontup® Dietary Supplement: Role of Green Tea Catechins.

Epigallocatechin gallate (EGCG) is an inhibitor of DYRK1A, a serine/threonine kinase considered to be a major contributor of cognitive dysfunctions in Down syndrome (DS). Two clinical trials in adult patients with DS have shown the safety and efficacy to improve cognitive phenotypes using commercial green tea extract containing EGCG (45% content). In the present study, we performed a preclinical study using FontUp®, a new nutritional supplement with a chocolate taste specifically formulated for the nutritional needs of patients with DS and enriched with a standardized amount of EGCG in young mice overexpressing Dyrk1A (TgBACDyrk1A). This preparation is differential with previous one used, because its green tea extract has been purified to up 94% EGCG of total catechins. We analyzed the in vitro effect of green tea catechins not only for EGCG, but for others residually contained in FontUp®, on DYRK1A kinase activity. Like EGCG, epicatechin gallate was a noncompetitive inhibitor against ATP, molecular docking computations confirming these results. Oral FontUp® normalized brain and plasma biomarkers deregulated in TgBACDyrk1A, without negative effect on liver and cardiac functions. We compared the bioavailability of EGCG in plasma and brain of mice and have demonstrated that EGCG had well crossed the blood-brain barrier.

Contrasting effects of membrane enrichment with polyunsaturated fatty acids on phospholipid composition and cholesterol efflux from cholesterol-loaded J774 mouse or primary human macrophages.

A high consumption of polyunsaturated fatty acids (PUFAs), particularly n-3 PUFAs, is atheroprotective. PUFAs incorporation into membrane phospholipids alters the functionality of membrane proteins. We studied the consequences of the in vitro supplementation of several PUFAs on the FA profiles and on ABCA1-dependent cholesterol efflux capacities from cholesterol-loaded macrophages. Arachidonic acid (AA, C20:4 n-6) and, to a lesser extent, eicosapentaenoic acid (EPA, C20:5 n-3), dose-dependently impaired cholesterol efflux from cholesterol-loaded J774 mouse macrophages without alterations in ABCA1 expression, whereas docosahexaenoic acid (DHA, C22:6 n-3) had no impact. AA cells exhibited higher proportions of arachidonic acid and adrenic acid (C22:4 n-6), its elongation product. EPA cells exhibited slightly higher proportions of EPA associated with much higher proportions of docosapentaenoic acid (C22:5 n-3), its elongation product and with lower proportions of AA. Conversely, both EPA and DHA and, to a lesser extent, AA decreased cholesterol efflux from cholesterol-loaded primary human macrophages (HMDM). The differences observed in FA profiles after PUFA supplementations were different from those observed for the J774 cells. In conclusion, we are the first to report that AA and EPA, but not DHA, have deleterious effects on the cardioprotective ABCA1 cholesterol efflux pathway from J774 foam cells. Moreover, the membrane incorporation of PUFAs does not have the same impact on cholesterol efflux from murine (J774) or human (HMDM) cholesterol-loaded macrophages. This finding emphasizes the key role of the cellular model in cholesterol efflux studies and may partly explain the heterogeneous literature data on the impact of PUFAs on cholesterol efflux.

Deciphering the Link Between Hyperhomocysteinemia and Ceramide Metabolism in Alzheimer-Type Neurodegeneration.

Aging is one of the strongest risk factor for Alzheimer's disease (AD). However, several data suggest that dyslipidemia can either contribute or serve as co-factors in AD appearance. AD could be examined as a metabolic disorder mediated by peripheral insulin resistance. Insulin resistance is associated with dyslipidemia, which results in increased hepatic ceramide generation. Hepatic steatosis induces pro-inflammatory cytokine activation which is mediated by the increased ceramides production. Ceramides levels increased in cells due to perturbation in sphingolipid metabolism and upregulated expression of enzymes involved in ceramide synthesis. Cytotoxic ceramides and related molecules generated in liver promote insulin resistance, traffic through the circulation due to injury or cell death caused by local liver inflammation, and because of their hydrophobic nature, they can cross the blood-brain barrier and thereby exert neurotoxic responses as reducing insulin signaling and increasing pro-inflammatory cytokines. These abnormalities propagate a cascade of neurodegeneration associated with oxidative stress and ceramide generation, which potentiate brain insulin resistance, apoptosis, myelin degeneration, and neuro-inflammation. Therefore, excess of toxic lipids generated in liver can cause neurodegeneration. Elevated homocysteine level is also a risk factor for AD pathology and is narrowly associated with metabolic diseases and non-alcoholic fatty liver disease. The existence of a homocysteine/ceramides signaling pathway suggests that homocysteine toxicity could be partly mediated by intracellular ceramide accumulation due to stimulation of ceramide synthase. In this article, we briefly examined the role of homocysteine and ceramide metabolism linking metabolic diseases and non-alcoholic fatty liver disease to AD. We therefore analyzed the expression of mainly enzymes implicated in ceramide and sphingolipid metabolism and demonstrated deregulation of de novo ceramide biosynthesis and S1P metabolism in liver and brain of hyperhomocysteinemic mice.

Investigation of lipid modifications in J774 macrophages by vibrational spectroscopies after eicosapentaenoic acid membrane incorporation in unloaded and cholesterol-loaded cells.

Atherosclerosis is an inflammatory disease of the arterial wall caused by the formation of an atheroma plaque in the vessel wall. The uptake of modified LDL lipoproteins by sub-endothelial macrophages induces the latter's transformation into foam cells, which is the key step of atheroma plaque formation. The modifications of neutral lipids caused by foam cells formation are marked by the appearance of lipid droplets. Polyunsaturated fatty acids (PUFAs) incorporation into membrane phospholipids (PL) modifies their composition, which may influence membrane protein functions. The incorporation of eicosapentaenoic acid (EPA) reduces the anti-atherogenic ABCA1 (ATP Binding Cassette transporter A1) pathway and induces PLs modifications. In order to study lipids directly in the cell environment, a comparative study is conducted by vibrational spectroscopies on murine macrophages J774, loaded or not with cholesterol, which were enriched or not with eicosapentaenoic acid (EPA). The study enabled to identify changes in the spectral signature after cells enrichment with fatty acid (FA) relying only on chemometric analysis without deuterium labelling. Results highlighted spectral changes in the regions attributed to lipids associated to triglycerides, phospholipids and cholesterol in both Raman and IR.

What can millions of laboratory test results tell us about the temporal aspect of data quality? Study of data spanning 17 years in a clinical data warehouse.

OBJECTIVE: To identify common temporal evolution profiles in biological data and propose a semi-automated method to these patterns in a clinical data warehouse (CDW). MATERIALS AND METHODS: We leveraged the CDW of the European Hospital Georges Pompidou and tracked the evolution of 192 biological parameters over a period of 17 years (for 445,000 + patients, and 131 million laboratory test results). RESULTS: We identified three common profiles of evolution: discretization, breakpoints, and trends. We developed computational and statistical methods to identify these profiles in the CDW. Overall, of the 192 observed biological parameters (87,814,136 values), 135 presented at least one evolution. We identified breakpoints in 30 distinct parameters, discretizations in 32, and trends in 79. DISCUSSION AND CONCLUSION: our method allowed the identification of several temporal events in the data. Considering the distribution over time of these events, we identified probable causes for the observed profiles: instruments or software upgrades and changes in computation formulas. We evaluated the potential impact for data reuse. Finally, we formulated recommendations to enable safe use and sharing of biological data collection to limit the impact of data evolution in retrospective and federated studies (e.g. the annotation of laboratory parameters presenting breakpoints or trends).

LPS-Induced Inflammation Abolishes the Effect of DYRK1A on IkB Stability in the Brain of Mice.

Down syndrome is characterized by premature aging and dementia with neurological features that mimic those found in Alzheimer's disease. This pathology in Down syndrome could be related to inflammation, which plays a role in other neurodegenerative diseases. We previously found a link between the NFkB pathway, long considered a prototypical proinflammatory signaling pathway, and the dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A). DYRK1A is associated with early onset of Alzheimer's disease in Down syndrome patients. Here, we sought to determine the role of DYRK1A on regulation of the NFkB pathway in the mouse brain. We found that over-expression of Dyrk1A (on a C57BL/6J background) stabilizes IκBα protein levels by inhibition of calpain activity and increases cytoplasmic p65 sequestration in the mouse brain. In contrast, Dyrk1A-deficient mice (on a CD1 background) have decreased IκBα protein levels with an increased calpain activity and decreased cytoplasmic p65 sequestration in the brain. Taken together, our results demonstrate a role of DYRK1A in regulation of the NFkB pathway. However, decreased IκBα and DYRK1A protein levels associated with an increased calpain activity were found in the brains of mice over-expressing Dyrk1A after lipopolysaccharide treatment. Although inflammation induced by lipopolysaccharide treatment has a positive effect on calpastatin and a negative effect on DYRK1A protein level, a positive effect on microglial activation is maintained in the brains of mice over-expressing Dyrk1A.

Homocysteine-lowering gene therapy rescues signaling pathways in brain of mice with intermediate hyperhomocysteinemia.

Hyperhomocysteinemia due to cystathionine beta synthase (CBS) deficiency is associated with diverse cognitive dysfunction. Considering the role of the serine/threonine kinase DYRK1A, not only in developmental defects with life-long structural and functional consequences, but also in multiple neurodegenerative diseases, its protein expression and kinase activity has been analyzed in brain of heterozygous CBS deficient mice and found to be increased. We previously demonstrated that specific liver treatment with an adenovirus expressing Dyrk1A normalizes hepatic DYRK1A level and decreases hyperhomocysteinemia in mice with moderate to intermediate hyperhomocysteinemia. We here use a hepatocyte-specific recombinant adeno-associated viral (AAV) serotype 8-mediated DYRK1A gene therapy (AAV2/8-DYRK1A) to analyze the effect of hepatic Dyrk1A gene transfer on some altered molecular mechanisms in brain of mice with intermediate hyperhomocysteinemia. Our selective hepatic treatment alleviates altered DYRK1A protein level and signaling pathways in brain of mice, the MAPK/ERK and PI3K/Akt pathways initiated by receptor tyrosine kinase, the BDNF dependent TrkB pathway, and NFkB pathway. These results demonstrate the positive effect of AAV2/8-DYRK1A gene transfer on neuropathological and inflammatory processes in brain of mice with intermediate hyperhomocysteinemia.

Role of myocardial collagen degradation and fibrosis in right ventricle dysfunction in transposition of the great arteries after atrial switch.

BACKGROUND: Heart failure is a serious event in patients with transposition of the great arteries (D-TGA) after atrial redirection surgery. We aimed to determine the association between myocardial fibrosis and systolic and diastolic systemic right ventricle (sRV) dysfunction. METHODS: Diastolic and systolic function of sRV was prospectively assessed using echocardiography and cardiac magnetic resonance imaging (CMR) in 48 patients with atrially switched D-TGA and 26 healthy subjects. Diastolic function of the subaortic ventricle was assessed by echocardiography Doppler and DTI. In CMR, ejection fraction of sRV and wall stress defined as the product of the systolic blood pressure and volume/mass ratio were assessed. Fibrosis extent within sRV myocardium was evaluated using gadolinium-enhanced magnetic resonance and serum collagen turnover biomarkers. RESULTS: Late gadolinium enhancement (LGE) was found in 35% of D-TGA patients, and the collagen degradation biomarker pro-MMP1:TIMP1 ratio was significantly increased in D-TGA patients compared to healthy subjects (1.0 × 10-2vs. 2.5 × 10-2, p = 0.04). Increase in sRV wall stress was significantly associated with LGE (p = 0.01) and pro-MMP1:TIMP1 ratio (r = 0.77, p < 0.01). After adjustment for age, sex, BMI, blood pressure and cardiac treatment, pro-MMP1:TIMP1 ratio was the strongest determinant of sRVEF (R2 = 0.85, p < 0.01). Pro-MMP1:TIMP1 ratio was also significantly correlated with the early diastolic filling parameter E/E' (r = 0.53, p = 0.02), but this was not anymore the case after adjustment. CONCLUSIONS: Diastolic and systolic sRV dysfunction is related to myocardial collagen degradation and fibrosis. Research in medical therapies that reduce systemic sRV afterload and limit collagen degradation is warranted in this setting.

Reduced endothelial thioredoxin-interacting protein protects arteries from damage induced by metabolic stress in vivo.

Although thioredoxin-interacting protein (TXNIP) is involved in a variety of biologic functions, the contribution of endothelial TXNIP has not been well defined. To investigate the endothelial function of TXNIP, we generated a TXNIP knockout mouse on the Cdh5-cre background (TXNIPfl/fl cdh5cre). Control (TXNIPfl/fl) and TXNIPfl/fl cdh5cre mice were fed a high protein-low carbohydrate (HP-LC) diet for 3 mo to induce metabolic stress. We found that TXNIPfl/fl and TXNIPfl/fl cdh5cre mice on an HP-LC diet displayed impaired glucose tolerance and dyslipidemia concretizing the metabolic stress induced. We evaluated the impact of this metabolic stress on mice with reduced endothelial TXNIP expression with regard to arterial structure and function. TXNIPfl/fl cdh5cre mice on an HP-LC diet exhibited less endothelial dysfunction than littermate mice on an HP-LC diet. These mice were protected from decreased aortic medial cell content, impaired aortic distensibility, and increased plasminogen activator inhibitor 1 secretion. This protective effect came with lower oxidative stress and lower inflammation, with a reduced NLRP3 inflammasome expression, leading to a decrease in cleaved IL-1ß. We also show the major role of TXNIP in inflammation with a knockdown model, using a TXNIP-specific, small interfering RNA included in a lipoplex. These findings demonstrate a key role for endothelial TXNIP in arterial impairments induced by metabolic stress, making endothelial TXNIP a potential therapeutic target.-Bedarida, T., Domingues, A., Baron, S., Ferreira, C., Vibert, F., Cottart, C.-H., Paul, J.-L., Escriou, V., Bigey, P., Gaussem, P., Leguillier, T., Nivet-Antoine, V. Reduced endothelial thioredoxin-interacting protein protects arteries from damage induced by metabolic stress in vivo.

Blood lipid tests in 2017.

Strong epidemiological evidence supports a causal relationship between dyslipidemia and atherosclerotic cardio-vascular disease, which remains the leading cause of death and morbidity worldwide. A lipid profile (total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides) is recommended at the initial evaluation for the assessment of the cardio-vascular risk. A commentary of the lipid profile for the clinician and mostly for the patient should be stated on the lab report. Quantifying the cardio-vascular risk using the SCORE (systematic coronary risk estimation) system, as recommended by the Haute autorité de santé (HAS), is the starting point to establish therapeutic goals and treatment strategies. It may be important to emphasize therapeutic goals in lipid reports in order to better monitor lipid profiles at appropriate intervals to assess compliance and therapeutic efficacy for patients on lipid lowering therapy.

Eicosapentaenoic acid membrane incorporation impairs cholesterol efflux from cholesterol-loaded human macrophages by reducing the cholesteryl ester mobilization from lipid droplets.

A diet containing a high n-3/n-6 polyunsaturated fatty acids (PUFA) ratio has cardioprotective properties. PUFAs incorporation into membranes influences the function of membrane proteins. We investigated the impact of the membrane incorporation of PUFAs, especially eicosapentaenoic acid (EPA) (C20:5 n-3), on the anti-atherogenic cholesterol efflux pathways. We used cholesteryl esters (CE)-loaded human monocyte-derived macrophages (HMDM) to mimic foam cells exposed to the FAs for a long period of time to ensure their incorporation into cellular membranes. Phospholipid fraction of EPA cells exhibited high levels of EPA and its elongation product docosapentaenoic acid (DPA) (C22:5 n-3), which was associated with a decreased level of arachidonic acid (AA) (C20:4 n-6). EPA 70µM reduced ABCA1-mediated cholesterol efflux to apolipoprotein (apo) AI by 30% without any alteration in ABCA1 expression. The other tested PUFAs, DPA, docosahexaenoic acid (DHA) (C22:6 n-3), and AA, were also able to reduce ABCA1 functionality while the monounsaturated oleic FA slightly decreased efflux and the saturated palmitic FA had no impact. Moreover, EPA also reduced cholesterol efflux to HDL mediated by the Cla-1 and ABCG1 pathways. EPA incorporation did not hinder efflux in free cholesterol-loaded HMDM and did not promote esterification of cholesterol. Conversely, EPA reduced the neutral hydrolysis of cytoplasmic CE by 24%. The reduced CE hydrolysis was likely attributed to the increase in cellular TG contents and/or the decrease in apo E secretion after EPA treatment. In conclusion, EPA membrane incorporation reduces cholesterol efflux in human foam cells by reducing the cholesteryl ester mobilization from lipid droplets.

Conjugation of squalene to gemcitabine as unique approach exploiting endogenous lipoproteins for drug delivery.

Once introduced in the organism, the interaction of nanoparticles with various biomolecules strongly impacts their fate. Here we show that nanoparticles made of the squalene derivative of gemcitabine (SQGem) interact with lipoproteins (LPs), indirectly enabling the targeting of cancer cells with high LP receptors expression. In vitro and in vivo experiments reveal preeminent affinity of the squalene-gemcitabine bioconjugates towards LP particles with the highest cholesterol content and in silico simulations further display their incorporation into the hydrophobic core of LPs. To the best of our knowledge, the use of squalene to induce drug insertion into LPs for indirect cancer cell targeting is a novel concept in drug delivery. Interestingly, not only SQGem but also other squalene derivatives interact similarly with lipoproteins while such interaction is not observed with liposomes. The conjugation to squalene represents a versatile platform that would enable efficient drug delivery by simply exploiting endogenous lipoproteins.

Effect of lyophilized prune extract on hyperhomocysteinemia in mice.

Altered homocysteine metabolism defined as hyperhomocysteinemia is implicated as pathogenic factor in several cardiovascular diseases and atherosclerosis. The purpose of this study was to investigate the efficacy of prune extract, a good source of phenolic antioxidants, on lowering plasma homocysteine level in male hyperhomocysteinemic mice from average weight of 28 g. The administration of lyophilized prune extract was carried out by intraperitoneal injection one day preceding and one hour before sacrifice of mice. Prune extract decreased significantly plasma homocysteine level, correlated with an increased activity of S-adenosylhomocysteine (SAH) hydrolase and NAD(P)H: quinone oxydoreductase-1 activities. Our results suggest a beneficial effect of prune extract on hyperhomocysteinemia with reduction of homocysteine level by its conversion on to SAH by S-adenosylhomocysteine hydrolase, which is activated by NAD+, a by-product of NAD(P)H: quinone oxydo reductase-1.