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International audience; Background and aims: Apolipoprotein (apo) C1 is a 6.6 kDa protein associated with HDL and VLDL. ApoC1 alters triglyceride clearance, and it also favors cholesterol accumulation in HDL, especially by inhibiting CETP in human plasma. Apart from studies in mice, which lack CETP, the impact of apoC1 on atherosclerosis in animal models expressing CETP, like in humans, is not known. This study aimed at determining the net effect of human apoC1 on atherosclerosis in rabbits, a species with naturally high CETP activity but with endogenous apoC1 without CETP inhibitory potential.Methods: Rabbits expressing a human apoC1 transgene (HuApoC1Tg) were generated and displayed significant amounts of human apoC1 in plasma.Results: After cholesterol feeding, atherosclerosis lesions were significantly less extensive (-22%, p < 0.05) and HDL displayed a reduced ability to serve as CETP substrates (-25%, p < 0.05) in HuApoC1Tg rabbits than in WT littermates. It was associated with rises in plasma HDL cholesterol level and PON-1 activity, and a decrease in the plasma level of the lipid oxidation markers 12(S)-HODE and 8(S)HETE. In chow-fed animals, the level of HDL-cholesterol was also significantly higher in HuApoC1Tg than in WT animals (0.83 ± 0.11 versus 0.73 ± 0.11 mmol/L, respectively, p < 0.05), and it was associated with significantly lower CETP activity (cholesteryl ester transfer rate, -10%, p < 0.05; specific CETP activity, -14%, p < 0.05).Conclusions: Constitutive expression of fully functional human apoC1 in transgenic rabbit attenuates atherosclerosis. It was found to relate, at least in part, to the inhibition of plasma CETP activity and to alterations in plasma HDL.

International audience; Background : Bisphenol S is an endocrine disruptor exhibiting metabolic disturbances, especially following perinatal exposures. To date, no data are available on the obesogen effects of BPS in a mutligenerational issue.Objectives : We investigated obesogen effects of BPS in a multigenerational study by focusing on body weight, adipose tissue and plasma parameters in male and female mice.Methods : Pregnant C57BL6/J mice were exposed to BPS (1.5 μg/kg bw/day ie a human equivalent dose of 0.12 μg/kg bw/day) by drinking water from gestational day 0 to post natal day 21. All offsprings were fed with a high fat diet during 15 weeks. Body weight was monitored weekly and fat mass was measured before euthanasia. At euthanasia, blood glucose, insuline, triglyceride, cholesterol and no esterified fatty acid plasma levels were determined and gene expressions in visceral adipose tissue were assessed. F1 males and females were mated to obtain the F2 generation. Likewise, the F2 mice were cross-bred to obtain F3. The same analyses were performed.Results : In F1 BPS induced an overweight in male mice associated to lipolysis gene expressions upregulation. In F1 females, dyslipidemia was observed. In F2, BPS exposure was associated to an increase in body weight, fat and VAT masses in males and females. Several plasma parameters were increased but with a sex related pattern (blood glucose, triglycerides and cholesterol in males and NEFA in females). We observed a down-regulation in mRNA expression of gene involved in lipogenesis and in lipolysis for females but only in the lipogenesis for males. In F3, a decrease in VAT mass and an upregulation of lipogenesis gene expression occurred only in females.Conclusions : BPS perinatal exposure induced sex-dependent obesogen multigenerational effects, the F2 generation being the most impacted. Transgenerational disturbances persisted only in females.

Objective: Glucocorticoids (GC) are associated with increased cardiovascular morbidity despite increased HDL-C concentration. HDL-mediated cholesterol efflux, a major anti-atherogenic property of HDL particles, is negatively associated with CVD risk. We aimed to determine whether HDL-mediated cholesterol efflux was influenced by GC. Design: Prospective, observational study. Methods: Lipid parameters, HDL composition, HDL-mediated cholesterol efflux, cholesteryl ester transfer protein, phospholipid transfer protein and lecithin cholesterol acyl-transferase (LCAT) activities were determined in ten patients with giant cell arteritis before and 3 months after GC introduction and in seven control subjects. HDL concentration and composition, HDL-mediated cholesterol efflux and LCAT activity were determined in GC-treated mice. Results: In patients, HDL-C concentration was higher after than before treatment GC-treatment (P = 0.002), while HDL-mediated cholesterol efflux was decreased (P = 0.008) and negatively associated with the proportion of cholesteryl ester in HDL (P = 0.04), independently of CRP. As well, in mice, HDL-C level was increased after GC exposure (P = 0.04) and HDL-mediated cholesterol efflux decreased (P = 0.04). GC-treated patients had higher cholesteryl ester content in HDL, higher HDL2-to-HDL3 ratio and higher LCAT activity than before treatment (P = 0.008, P = 0.02 and P = 0.004, respectively). Conclusions: We report, for the first time, that in patients with giant cell arteritis and mice treated with GC, HDL-mediated cholesterol efflux was impaired by GC besides an increased HDL-C level. This impaired HDL functionality, possibly related to HDL enrichment in cholesteryl ester, could contribute to the increased CVD risk observed in GC-treated patients. Further studies are needed in larger populations, to further decipher the effect of GC on HDL.

OBJECTIVE An original device for exploring taste-guided reward behavior in rodents using a newly designed computer-controlled liquid delivery system equipped with "lickometers" is described. METHODS This octagonal shaped "gustometer" is composed of eight shutters that give random access during a few seconds to eight bottles delivering different liquid stimuli. This original design, which forces the animal to move for access to the drinking source, allows a simultaneous analysis of the licking behavior and motivation to drink. Determination of the sucrose licking behavior in diet-induced obese mice was used to validate this method because nutritional obesity disturbs the sweet taste perception in rodents. RESULTS A rise in sucrose response threshold and a decrease in the motivation to drink sweet solutions were found in mice fed the obesogenic diet. These data were highly reproducible among independent studies and corroborated the existence of functional links between diet-induced obesity and gustation in rodents. CONCLUSIONS The FRM-8 gustometer appears to be especially suitable for exploring determinants of behavioral outputs in response to oro-sensory stimuli in the mouse. It also provides substantial information on the taste-reward relationship, useful for better understanding the origin of gustatory efficiency or, conversely, dysfunction, as reported in nutritional obesity.

Obesity may not be consistently associated with metabolic disorders and mortality later in life, prompting exploration of the challenging concept of healthy obesity. Here, the consumption of a high-fat/high-sucrose (HF/HS) diet produces hyperglycaemia and hypercholesterolaemia, increases oxidative stress, increases endotoxaemia, expands adipose tissue (with enlarged adipocytes, enhanced macrophage infiltration and the accumulation of cholesterol and oxysterols), and reduces the median lifespan of obese mice. Despite the persistence of obesity, supplementation with a polyphenol-rich plant extract (PRPE) improves plasma lipid levels and endotoxaemia, prevents macrophage recruitment to adipose tissues, reduces adipose accumulation of cholesterol and cholesterol oxides, and extends the median lifespan. PRPE drives the normalization of the HF/HS-mediated functional enrichment of genes associated with immunity and inflammation (in particular the response to lipopolysaccharides). The long-term limitation of immune cell infiltration in adipose tissue by PRPE increases the lifespan through a mechanism independent of body weight and fat storage and constitutes the hallmark of a healthy adiposity trait.

International audience

Accepted for publication in Nuclear Instruments and Methods in Physics Research A; International audience; The level structure of nuclei offers a large amount and variety of information to improve our knowledge of the strong interaction and of mesoscopic quantum systems. Gamma spectroscopy is a powerful tool to perform such studies: modern gamma multi-detectors present increasing performances in terms of sensitivity and efficiency, allowing to extend ever more our ability to observe and characterize abundant nuclear states. For instance, the high-spin part of level schemes often reflects intriguing nuclear shape phenomena: this behaviour is unveiled by high-fold experimental data analysed through multi-coincidence spectra, in which long deexcitation cascades become observable. Determining the intensity of newly discovered transitions is important to characterize the nuclear structure and formation mechanism of the emitting levels. However, it is not trivial to relate the apparent intensity observed in multi-gated spectra to the actual transition intensity. In this work, we introduce the basis of a formalism affiliated with graph theory: we have obtained analytic expressions from which data-analysis methods can eventually be derived to recover this link in a rigorous way.

IF (4.042); International audience; ObjectiveAn original device for exploring taste‐guided reward behavior in rodents using a newly designed computer‐controlled liquid delivery system equipped with “lickometers” is described.MethodsThis octagonal shaped “gustometer” is composed of eight shutters that give random access during a few seconds to eight bottles delivering different liquid stimuli. This original design, which forces the animal to move for access to the drinking source, allows a simultaneous analysis of the licking behavior and motivation to drink. Determination of the sucrose licking behavior in diet‐induced obese mice was used to validate this method because nutritional obesity disturbs the sweet taste perception in rodents.ResultsA rise in sucrose response threshold and a decrease in the motivation to drink sweet solutions were found in mice fed the obesogenic diet. These data were highly reproducible among independent studies and corroborated the existence of functional links between diet‐induced obesity and gustation in rodents.ConclusionsThe FRM‐8 gustometer appears to be especially suitable for exploring determinants of behavioral outputs in response to oro‐sensory stimuli in the mouse. It also provides substantial information on the taste‐reward relationship, useful for better understanding the origin of gustatory efficiency or, conversely, dysfunction, as reported in nutritional obesity.

Obesity is a major public health problem. An in-depth knowledge of the molecular mechanisms of oro-sensory detection of dietary lipids may help fight it. Humans and rodents can detect fatty acids via lipido-receptors, such as CD36 and GPR120. We studied the implication of the MAPK pathways, in particular, ERK1/2, in the gustatory detection of fatty acids. Linoleic acid, a dietary fatty acid, induced via CD36 the phosphorylation of MEK1/2-ERK1/2-ETS-like transcription factor-1 cascade, which requires Fyn-Src kinase and lipid rafts in human taste bud cells (TBCs). ERK1/2 cascade was activated by Ca2+ signaling via opening of the calcium-homeostasis modulator-1 (CALHM1) channel. Furthermore, fatty acid–evoked Ca2+ signaling and ERK1/2 phosphorylation were decreased in both human TBCs after small interfering RNA knockdown of CALHM1 channel and in TBCs from Calhm1−/− mice. Targeted knockdown of ERK1/2 by small interfering RNA or PD0325901 (MEK1/2 inhibitor) in the tongue and genetic ablation of Erk1 or Calhm1 genes impaired preference for dietary fat in mice. Lingual inhibition of ERK1/2 in healthy volunteers also decreased orogustatory sensitivity for linoleic acid. Our data demonstrate that ERK1/2-MAPK cascade is regulated by the opening of CALHM1 Ca2+ channel in TBCs to modulate orogustatory detection of dietary lipids in mice and humans.—Subramaniam, S., Ozdener, M. H., Abdoul-Azize, S., Saito, K., Malik, B., Maquart, G., Hashimoto, T., Marambaud, P., Aribi, M., Tordoff, M. G., Besnard, P., Khan, N. A. ERK1/2 activation in human taste bud cells regulates fatty acid signaling and gustatory perception of fat in mice and humans.

International audience; Plasma phospholipid transfer protein (PLTP) increases the circulating levels of proatherogenic lipoproteins, accelerates blood coagulation, and modulates inflammation. The role of PLTP in the development of abdominal aortic aneurysm (AAA) was investigated by using either a combination of mechanical and elastase injury at one site of mouse aorta (elastase model) or continuous infusion of angiotensin II in hyperlipidemic ApoE-knockout mice (Ang II model). With the elastase model, complete PLTP deficiency was associated with a significantly lower incidence and a lesser degree of AAA expansion. With the Ang II model, findings were consistent with those in the elastase model, with a lower severity grade in PLTP-deficient mice, an intermediate phenotype in PLTP-deficient heterozygotes, and a blunted effect of the PLTP-deficient trait when restricted to bone marrow-derived immune cells. The protective effect of whole-body PLTP deficiency in AAA was illustrated further by a lesser degree of adventitia expansion, reduced elastin degradation, fewer recruited macrophages, and less smooth muscle cell depletion in PLTP-deficient than in wild-type mice, as evident from comparative microscopic analysis of aorta sections. Finally, cumulative evidence supports the association of PLTP deficiency with reduced expression and activity levels of matrix metalloproteinases, known to degrade elastin and collagen. We conclude that PLTP can play a significant role in the pathophysiology of AAA.