High Fat/High Glucose Diet Induces Metabolic Syndrome in an Experimental Rat Model.

Metabolic syndrome (MetS) is defined as a constellation of many metabolic disorders such as hypertension, impaired glucose tolerance, dyslipidemia and obesity, being this last disorder a key factor in the etiology of the syndrome. The widespread of MetS in actual society, mainly in developed countries, is becoming an important health problem and is increasing the need to develop new treatments against this pathology is increasing fast. The main objective of the present study was to evaluate the MetS-associated alterations developed in a new glucose diet-induced-obesity (DIO) rodent model. These alterations were also compared to those alterations developed in a fructose-DIO rodent model. Wistar rats were divided into four groups: Control (C), High-fat (HF), High-fat/high-fructose (HFF) and High-fat/high-glucose (HFG). The animals were fed ad libitum for 20 weeks. At the end of the study, HFG animals showed lower expression of energy expenditure genes when compared to the other DIO groups. Oxidative stress biomarkers such as MDA and mitochondrial RT-qPCR analyses showed an increase of oxidative damage together with mitochondrial dysfunction in HFG group. This group also showed increased insulin and glucose plasma levels, though HFF animals showed the greatest increase on these parameters. All DIO groups showed increased plasma levels of triglycerides. Altogether, our results indicated a better impact of glucose than fructose, when combined with a high-fat diet, to induce most of the alterations associated with MetS in rats. In addition, our research facilitates a new animal model to evaluate future treatments for MetS.post-print2242 K

Effect of long-term deficit irrigation on tomato and goji berry quality: from fruit composition to in vitro bioaccessibility of carotenoids

Drought is a persistent challenge for horticulture, affecting various aspects of fruit development and ultimately fruit quality, but the effect on nutritional value has been under-investigated. Here, fruit quality was studied on six tomato genotypes and one goji cultivar under deficit irrigation (DI), from fruit composition to in vitro bioaccessibility of carotenoids. For both species, DI concentrated most health-related metabolites in fresh fruit. On a dry mass basis, DI increased total phenolic and sugar concentration, but had a negative or insignificant impact on fruit ascorbic acid, organic acid, and alcohol-insoluble matter contents. DI also reduced total carotenoids content in tomato (−18.7% on average), especially β-carotene (−32%), but not in goji berry DW (+15.5% and +19.6%, respectively). DI reduced the overall in vitro bioaccessibility of carotenoids to varying degrees depending on the compound and plant species. Consequently, mixed micelles produced by digestion of fruits subjected to DI contained either the same or lesser quantities of carotenoids, even though fresh fruits could contain similar or higher quantities. Thus, DI effects on fruit composition were species and genotype dependent, but an increase in the metabolite concentration did not necessarily translate into greater bioaccessibility potentially due to interactions with the fruit matri

Beta-Carotene Reduces Body Adiposity of Mice via BCMO1

Evidence from cell culture studies indicates that β-carotene-(BC)-derived apocarotenoid signaling molecules can modulate the activities of nuclear receptors that regulate many aspects of adipocyte physiology. Two BC metabolizing enzymes, the BC-15,15′-oxygenase (Bcmo1) and the BC-9′,10′-oxygenase (Bcdo2) are expressed in adipocytes. Bcmo1 catalyzes the conversion of BC into retinaldehyde and Bcdo2 into β-10′-apocarotenal and β-ionone. Here we analyzed the impact of BC on body adiposity of mice. To genetically dissect the roles of Bcmo1 and Bcdo2 in this process, we used wild-type and Bcmo1-/- mice for this study. In wild-type mice, BC was converted into retinoids. In contrast, Bcmo1-/- mice showed increased expression of Bcdo2 in adipocytes and β-10′-apocarotenol accumulated as the major BC derivative. In wild-type mice, BC significantly reduced body adiposity (by 28%), leptinemia and adipocyte size. Genome wide microarray analysis of inguinal white adipose tissue revealed a generalized decrease of mRNA expression of peroxisome proliferator-activated receptor γ (PPARγ) target genes. Consistently, the expression of this key transcription factor for lipogenesis was significantly reduced both on the mRNA and protein levels. Despite β-10′-apocarotenoid production, this effect of BC was absent in Bcmo1-/- mice, demonstrating that it was dependent on the Bcmo1-mediated production of retinoids. Our study evidences an important role of BC for the control of body adiposity in mice and identifies Bcmo1 as critical molecular player for the regulation of PPARγ activity in adipocyte

Modulation of miRNA Expression by Dietary Polyphenols in apoE Deficient Mice: A New Mechanism of the Action of Polyphenols

Background: Polyphenols are the most abundant antioxidants in the human diet and are widespread constituents of fruits and beverages, such as tea, coffee or wine. Epidemiological, clinical and animal studies support a role of polyphenols in the prevention of various diseases, such as cardiovascular diseases, cancers or neurodegenerative diseases. Recent findings suggest that polyphenols could interact with cellular signaling cascades regulating the activity of transcription factors and consequently affecting the expression of genes. However, the impact of polyphenol on the expression of microRNA, small non-coding RNAs, has not yet been studied. The aim of this study was to investigate the impact of dietary supplementation with polyphenols at nutritional doses on miRNA expression in the livers of apolipoprotein E-deficient mice (apoE(-/-)) jointly with mRNA expression profiling. [br/] Methodology/Principal Findings: Using microarrays, we measured the global miRNA expression in the livers of wild-type (C57B6/J) mice or apoE(-/-) mice fed diets supplemented with one of nine different polyphenols or a control diet. This analysis revealed that knock-out of the apoE gene induced significant modulation in the expression of miRNA. Moreover, changes in miRNA expression were observed after polyphenol supplementation, and five miRNAs (mmu-miR-291b-5p, mmu-miR-296-5p, mmu-miR-30c-1*, mmu-miR-467b* and mmu-miR-374*) were identified as being commonly modulated by these polyphenols. We also observed that these polyphenols counteracted the modulation of miRNA expression induced by apoE mutation. Pathway analyses on these five miRNA-target genes revealed common pathways, some of which were also identified from a pathway analysis on mRNA profiles. [br/] Conclusion:This in vivo study demonstrated for the first time that polyphenols at nutritional doses modulate the expression of miRNA in the liver. Even if structurally different, all polyphenols induced a similar miRNA expression profile. Common pathways were identified from both miRNA-target and mRNA analysis, revealing cellular functions that could be regulated by polyphenols at both the miRNA and mRNA level

Vitamine E et physiologie du tissu adipeux

Vitamin E constitutes a family of eight molecules well-known for its antioxidant properties and its essentiality in fertility. Its ability to regulate gene expression is more and more described and could be a major actor of its biological activity. Adipose tissue which is the main store site of vitamin E within the body is also subjected to the regulatory effect of vitamin E. These regulations could strongly impact adipose tissue physiology

I-BABP et L-FABP, portrait croisé de deux protéines à la recherche de leur fonction

DIJON-BU Sciences Economie (212312102) / SudocSudocFranceF

Interrelationship between Vitamin D and Calcium in Obesity and Its Comorbid Conditions

International audienceObesity has been linked to vitamin D (VD) deficiency and low calcium (CAL) status. In the last decade, dietary supplementation of vitamin D and calcium (VD–CAL) have been extensively studied in animal experiments and human studies. However, the physiological mechanisms remain unknown as to whether the VD–CAL axis improves homeostasis and reduces biomarkers in regulating obesity and other metabolic diseases directly or indirectly. This review sought to investigate their connections. This topic was examined in scientific databases such as Web of Science, Scopus, and PubMed from 2011 to 2021, and 87 articles were generated for interpretation. Mechanistically, VD–CAL regulates from the organs to the blood, influencing insulin, lipids, hormone, cell, and inflammatory functions in obesity and its comorbidities, such as non-alcoholic fatty liver disease, cardiovascular disease, and type-2 diabetes mellitus. Nevertheless, previous research has not consistently shown that simultaneous VD–CAL supplementation affects weight loss or reduces fat content. This discrepancy may be influenced by population age and diversity, ethnicity, and geographical location, and also by degree of obesity and applied doses. Therefore, a larger prospective cohort and randomised trials are needed to determine the exact role of VD–CAL and their interrelationship

Le gène codant pour l’I-BABP est-il impliqué dans l’homéostasie du cholestérol ?

La réabsorption intestinale des acides biliaires joue un rôle prépondérant dans le maintien de l’homéostasie du cholestérol. En effet, la perte fécale des acides biliaires constitue une importante voie d’élimination physiologique du cholestérol. L’I-BABP (ileal bile acid-binding protein) est un polypeptide soluble largement exprimé dans les cellules absorbantes de l’intestin grêle distal, connues pour être le siège d’une réabsorption active extrêmement efficace des acides biliaires. Des résultats récents démontrent que l’expression du gène codant pour l’I-BABP est profondément influencée par les concentrations d’acides biliaires et de cholestérol. Cette régulation requiert l’intervention de facteurs de transcription (FXR, LXR, SREBP) dont on sait qu’ils jouent un rôle homéostatique crucial dans le métabolisme lipidique, en général, et dans celui du cholestérol, en particulier. Ces observations inédites suggèrent que l’expression du gène de l’I-BABP intervient dans le devenir des acides biliaires et du cholestérol à l’échelle de l’organisme

Recent insights into vitamin D, adipocyte, and adipose tissue biology

International audienc