Increased atherosclerotic plaque in AOC3 knock-out in ApoE-/- mice and characterization of AOC3 in atherosclerotic human coronary arteries

IntroductionAmine oxidase copper containing 3 (AOC3) displays adhesion between leukocytes and endothelial cells and enzymatic functions. Given its controversial role in atherogenesis, we proposed to investigate the involvement of AOC3 in the formation of atherosclerotic plaques in ApoE(-/-)AOC3(-/-) mice and human coronary arteries. MethodsLesions, contractile markers, and AOC3 were studied in aortic tissues from 15- and 25-week-old mice and different stages of human coronary atherosclerotic arteries by immunohistochemistry (IHC) and/or western blot. Human VSMCs, treated or not with LJP1586, an AOC3 inhibitor, were used to measure differentiation markers by qPCR. AOC3 co-localization with specific cell markers was studied by using confocal microscopy in mice and human samples. ResultsAt 15 weeks old, the absence of AOC3 was associated with increased lesion size, alpha-SMA, and CD3 staining in the plaque independently of a cholesterol modification. At 25 weeks old, advanced plaques were larger with equivalent staining for alpha-SMA while CD3 increased in the media from ApoE(-/-)AOC3(-/-) mice. At both ages, the macrophage content of the lesion was not modified. Contractile markers decreased whereas MCP-1 appeared augmented only in the 15-week-old ApoE(-/-)AOC3. AOC3 is mainly expressed by mice and human VSMC is slightly expressed by endothelium but not by macrophages. ConclusionAOC3 knock-out increased atherosclerotic plaques at an early stage related to a VSMC dedifferentiation associated with a higher T cells recruitment in plaques explained by the MCP-1 augmentation. This suggests that AOC3 may have an important role in atherosclerosis independent of its canonical inflammatory effect. The dual role of AOC3 impacts therapeutic strategies using pharmacological regulators of SSAO activity

Chemical Library Screening and Structure-Function Relationship Studies Identify Bisacodyl as a Potent and Selective Cytotoxic Agent Towards Quiescent Human Glioblastoma Tumor Stem-Like Cells

Cancer stem-like cells reside in hypoxic and slightly acidic tumor niches. Such microenvironments favor more aggressive undifferentiated phenotypes and a slow growing "quiescent state" which preserves them from chemotherapeutic agents that essentially target proliferating cells. Our objective was to identify compounds active on glioblastoma stem-like cells, including under conditions that mimick those found in vivo within this most severe and incurable form of brain malignancy. We screened the Prestwick Library to identify cytotoxic compounds towards glioblastoma stem-like cells, either in a proliferating state or in more slow-growing "quiescent" phenotype resulting from non-renewal of the culture medium in vitro. Compound effects were assessed by ATP-level determination using a cell-based assay. Twenty active molecules belonging to different pharmacological classes have thus been identified. Among those, the stimulant laxative drug bisacodyl was the sole to inhibit in a potent and specific manner the survival of quiescent glioblastoma stem-like cells. Subsequent structure-function relationship studies led to identification of 4,4'-dihydroxydiphenyl-2-pyridyl-methane (DDPM), the deacetylated form of bisacodyl, as the pharmacophore. To our knowledge, bisacodyl is currently the only known compound targeting glioblastoma cancer stem-like cells in their quiescent, more resistant state. Due to its known non-toxicity in humans, bisacodyl appears as a new potential anti-tumor agent that may, in association with classical chemotherapeutic compounds, participate in tumor eradication

Altérations métaboliques associées au traitement par antidépresseurs et thymorégulateurs (caractérisation d'un effet original de la Carbamazépine sur le développement adipocytaire)

Contexte scientifique : Les troubles de l'humeur uni et bipolaires sont aujourd'hui un problème de santé publique de premier plan. La carbamazépine, utilisée depuis longtemps comme anti-épileptique, est également un traitement thymorégulateur d'utilisation courante avec néanmoins de nombreux effets secondaires métaboliques. La prise de poids modérée qu'elle engendre est généralement considérée comme un effet d'origine centrale. But de l'étude : Nous avons étudié un impact potentiel direct des antidépresseurs et des thymorégulateurs sur le métabolisme et le développement de la cellule adipeuse, et analysé les mécanismes impliqués. Matériels et Méthodes : Nous avons testé l'effet de la carbamazépine sur plusieurs modèles cellulaires adipocytaires murins blancs et bruns (3T3-L1, 3T3-F442A, T37i) et humains, au stade de préadipocytes en différenciation, mais également d'adipocytes matures. Résultats : La carbamazépine inhibe la différenciation adipocytaire et réduit l'accumulation de triglycérides dans les différentes lignées étudiées, de façon dose- et temps-dépendante. Cet effet inhibiteur de la carabamazepine est faiblement réversible, et est d'autant plus puissant qu'elle est ajoutée précocement au cours de l'adipogenèse. Il persiste de façon beaucoup plus discrète dans l'adipocyte mature. Il implique un contrôle négatif de l'expansion clonale des jeunes adipocytes, ainsi que des mécanismes transcriptionnels majeurs de l'adipogenèse, tel que l'expression du peroxisome proliferator-activated receptor-gamma (PPAR gamma) et de la CCAAT/enhancer binding protein-alpha (C/EBP-alpha). Conclusion : Nous avons démontré que la carbamazepine exerce in vitro un effet inhibiteur direct sur la différenciation adipocytaire et l'accumulation de triglycérides, qui semble s'opposer de façon surprenante à son effet in vivo sur la prise de poids.ROUEN-BU Médecine-Pharmacie (765402102) / SudocSudocFranceF

Expression, régulation et fonctions de la "semicarbazide-sensitive amine oxidase" (SSAO) dans le tissu adipeux et la paroi vasculaire

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Obésité, inflammation et insulinorésistance : quel rôle pour les adipokines ?

Le tissu adipeux est reconnu comme un organe endocrine qui joue un rôle dans la physiopathologie de l'inflammation. Il sécrète des hormones comme la leptine et l'adiponectine et d'autres molécules comme des cytokines et chimiokines rassemblées sous le terme d'adipokines. Celles-ci, sont produites par les adipocytes, mais aussi par les macrophages infiltrant le tissu adipeux. Elles participent à la genèse d'un état inflammatoire chronique de faible intensité et interviennent très vraisemblablement dans la physiopathologie des complications cardiovasculaires de l'obésité et de l'insulinorésistance

Semicarbazide-Sensitive Amine Oxidase in Vascular Smooth Muscle Cells

International audienceCultured vascular smooth muscle cells (VSMCs) derived from rat aortic media were used to examine semicarbazide-sensitive amine oxidase (SSAO) expression during their differentiation process. In a defined serum-free medium permissive for in vitro VSMC differentiation, there was a large increase in SSAO mRNA and protein levels and in the related enzyme activity during the course of cell culture. This pattern of expression was concomitant with that of some smooth muscle–specific mRNA markers of differentiation. mRNAs in differentiated cultured VSMCs were comparable to those detected in total aorta and media. Pharmacological properties of SSAO present in VSMCs were similar to enzyme activities previously described in the aortic wall. In this model, we also demonstrated that methylamine, a physiological substrate of SSAO, activated 2-deoxyglucose transport in a time- and dose-dependent manner. This methylamine effect was reproduced by other SSAO substrates and was prevented by the SSAO inhibitor semicarbazide. It was antagonized in the presence of catalase, suggesting that SSAO-activated glucose transport was mediated through H 2 O 2 production. In addition, methylamine promoted glucose transporter 1 accumulation at the cell surface. Thus, we demonstrate for the first time the differentiation-dependent expression of SSAO in VSMCs and its role in the regulation of VSMC glucose uptake

Effect of Monoclonal Antibody Blockade of Long Fragment Neurotensin on Weight Loss, Behavior, and Metabolic Traits After High-Fat Diet Induced Obesity

Background: Obesity is a major public health problem of our time as a risk factor for cardiometabolic disease and the available pharmacological tools needed to tackle the obesity pandemic are insufficient. Neurotensin (NTS) is a 13 amino acid peptide, which is derived from a larger precursor hormone called proneurotensin or Long Form NTS (LF NTS). NTS modulates neuro-transmitter release in the central system nervous, and facilitates intestinal fat absorption in the gastrointestinal tract. Mice lacking LF NTS are protected from high fat diet (HFD) induced obesity, hepatic steatosis and glucose intolerance. In humans, increased levels of LF NTS strongly and independently predict the development of obesity, diabetes mellitus, cardiovascular disease and mortality. With the perspective to develop therapeutic tools to neutralize LF NTS, we developed a monoclonal antibody, specifically inhibiting the function of the LF NTS (LF NTS mAb). This antibody was tested for the effects on body weight, metabolic parameters and behavior in mice made obese by high-fat diet. Methods: C57bl/6j mice were subjected to high-fat diet (HFD) until they reached an obesity state, then food was switched to chow. Mice were treated with either PBS (control therapy) or LF NTS mAb at the dose of 5 mg/kg once a week (i.v.). Mice weight, plasma biochemical analysis, fat and muscle size and distribution and behavioral tests were performed during the losing weight period and the stabilization period. Results: Obese mice treated with the LF NTS mAb lost weight significantly faster than the control treated group. LF NTS mAb treatment also resulted in smaller fat depots, increased fecal cholesterol excretion, reduced liver fat and larger muscle fiber size. Moreover, mice on active therapy were also less stressed, more curious and more active, providing a possible explanation to their weight loss. Conclusion: Our results demonstrate that in mice subjected to HFD-induced obesity, a blockade of LF NTS with a monoclonal antibody results in reduced body weight, adipocyte volume and increased muscle fiber size, possibly explained by beneficial effects on behavior. The underlying mechanisms as well as any future role of LF NTS mAb as an anti-obesity agent warrants further studies

Severe insomnia is associated with hypertriglyceridemia in women with major depression treated in psychiatry settings

International audienceBACKGROUND:Hypertriglyceridemia (HTG) is a cardiovascular risk factor. In the general population, elevated fasting triglyceridemia (TG) is associated with insomnia. Since insomnia is a core symptom of Major Depressive Episodes (MDE), we studied the association of severe insomnia with HTG in major depression.METHODS:We used the baseline data of the METADAP cohort, comprising 624 patients with a current MDE in a context of Major Depressive Disorder treated in psychiatry settings, without current alcohol use disorders. Patients were screened for severe insomnia, defined by a score of four or more on the three Hamilton Depression Rating Scale (HDRS) sleep items, and for HTG characterised by TG≥200mg/dL.RESULTS:Severe insomnia was observed in 335(54%) patients with a current MDE, of whom 234(70%) were women; 49(8%) patients had HTG, of whom 25(51%) were women. 69(11%) patients were treated with lipid-lowering drugs. Severe insomnia was associated with a higher frequency of HTG in the whole sample (9.9% vs 5.6%, p=0.046) and in the subgroup of women (9.0% vs 2.0%, p=0.002). Multivariate logistic regression analyses adjusted for age, education levels, BMI and total HDRS scores confirmed the association between severe insomnia and HTG in the whole sample (OR=2.02, 95%CI [1.00-4.08], p=0.05) as well as in the subgroup of women (OR=4.82, 95%CI [1.5-15.5], p=0.008). No association was shown in men.PERSPECTIVES:HTG should be systematically investigated in depressed patients with severe insomnia and particularly in women. Further studies are needed to explain the association we observed between severe insomnia and HTG

The association of ARRB1 polymorphisms with response to antidepressant treatment in depressed patients

International audienceIntroduction: β-arrestin 1, a protein encoded by ARRB1 involved in receptor signaling, is a potential biomarker for the response to antidepressant drug (ATD) treatment in depression. We examined ARRB1 genetic variants for their association with response following ATD treatment in METADAP, a cohort of 6-month ATD-treated depressed patients. Methods: Patients ( n = 388) were assessed at baseline (M0) and after 1 (M1), 3 (M3), and 6 months (M6) of treatment for Hamilton Depression Rating Scale (HDRS) changes, response, and remission. Whole-gene ARRB1 variants identified from high-throughput sequencing were separated by a minor allele frequency (MAF)≥5%. Frequent variants (i.e., MAF≥5%) annotated by RegulomeDB as likely affecting transcription factor binding were analyzed using mixed-effects models. Rare variants (i.e., MAF<5%) were analyzed using a variant set analysis. Results: The variant set analysis of rare variants was significant in explaining HDRS score changes ( T = 878.9; p = 0.0033) and remission ( T = -1974.1; p = 0.034). Rare variant counts were significant in explaining response ( p = 0.016), remission ( p = 0.022), and HDRS scores at M1 ( p = 0.0021) and M3 ( p =<0.001). rs553664 and rs536852 were significantly associated with the HDRS score (rs553664: p = 0.0055 | rs536852: p = 0.046) and remission (rs553664: p = 0.026 | rs536852: p = 0.012) through their interactions with time. At M6, significantly higher HDRS scores were observed in rs553664 AA homozygotes (13.98 ± 1.06) compared to AG heterozygotes (10.59 ± 0.86; p = 0.014) and in rs536852 GG homozygotes (14.88 ± 1.10) compared to AG heterozygotes (11.26 ± 0.95; p = 0.0061). Significantly lower remitter rates were observed in rs536852 GG homozygotes (8%, n = 56) compared to AG heterozygotes (42%, n = 105) at M6 ( p = 0.0018). Conclusion: Our results suggest ARRB1 variants may influence the response to ATD treatment in depressed patients. Further analysis of functional ARRB1 variants and rare variant burden in other populations would help corroborate our exploratory analysis. β-arrestin 1 and genetic variants of ARRB1 may be useful clinical biomarkers for clinical improvement following ATD treatment in depressed individuals. Clinical Trial Registration: clinicaltrials.gov ; identifier NCT0052638

Metabolomic profiles of 38 acylcarnitines in major depressive episodes before and after treatment

Abstract Background Major depression is associated with changes in plasma L-carnitine and acetyl-L-carnitine. But its association with acylcarnitines remains unclear. The aim of this study was to assess metabolomic profiles of 38 acylcarnitines in patients with major depression before and after treatment compared to healthy controls (HCs). Methods Metabolomic profiles of 38 plasma short-, medium-, and long-chain acylcarnitines were performed by liquid chromatography-mass spectrometry in 893 HCs from the VARIETE cohort and 460 depressed patients from the METADAP cohort before and after 6 months of antidepressant treatment. Results As compared to HCs, depressed patients had lower levels of medium- and long-chain acylcarnitines. After 6 months of treatment, increased levels of medium- and long-chain acyl-carnitines were observed that no longer differed from those of controls. Accordingly, several medium- and long-chain acylcarnitines were negatively correlated with depression severity. Conclusions These medium- and long-chain acylcarnitine dysregulations argue for mitochondrial dysfunction through fatty acid β -oxidation impairment during major depression