Comparison of α-Tocopherol, α-Tocopherol Acetate, and α-Tocopheryl Polyethylene Glycol Succinate 1000 Absorption by Caco-2 TC7 Intestinal Cells

(1) Background: vitamin E is often supplemented in the form of tocopherol acetate, but it has poor bioavailability and can fail to correct blood tocopherol concentrations in some patients with severe cholestasis. In this context, α-tocopheryl polyethylene glycol succinate 1000 (TPGS) has been of value, but very little is known about the mechanisms of its absorption. The aim of our work was to evaluate the mechanisms of absorption/secretion of TPGS compared to tocopherol acetate (TAC) and α-tocopherol by human enterocyte-like Caco-2 TC7 cells. (2) Methods: two weeks post-confluence Caco-2 cells were incubated with tocopherol- or TAC- or TPGS-rich mixed micelles up to 24 h and, following lipid extraction, TAC and tocopherol amounts were measured by high performance liquid chromatography (HPLC) in apical, cellular, and basolateral compartments. (3) Results: at equivalent concentrations of tocopherol in the apical side, the amounts of tocopherol secreted at the basolateral pole of Caco-2 cells are (i) significantly greater when the tocopherol is in the free form in the micelles; (ii) intermediate when it is in the TAC form in the micelles (p < 0.001); and (iii) significantly lower with the TPGS form (p < 0.0001). Interestingly, our results show, for the first time, that Caco-2 cells secrete one or more esterified forms of the vitamin contained in TPGS at the basolateral side

Absorption of vitamin E in patients with genetic hypocholesterolemia

Les hypocholestérolémies génétiques représentent un ensemble de pathologies héréditaires du métabolisme caractérisées par une hypocholestérolémie inférieure au 5ème percentile pour l'âge et le sexe. Elles sont majoritairement dues à un défaut d'assemblage et de sécrétion des lipoprotéines entraînant, dès la période néonatale, une malabsorption des lipides et des vitamines liposolubles. Les conséquences à long terme peuvent être dramatiques (complications ophtalmologiques et neurologiques graves) si un traitement par vitamines liposolubles, en particulier vitamine E à fortes doses, n'est pas instauré rapidement. Pour ces raisons, l'étude clinique princeps a comparé une formulation de vitamine E rendue hydrosoluble (tocofersolan) à l'acétate de tocophérol liposoluble et traditionnellement utilisé en thérapeutique chez ces patients. En parallèle, un travail sur modèle cellulaire Caco2, nous a permis d'étudier les mécanismes d'absorption/sécrétion de ces deux formulations de vitamine E afin de mieux appréhender les mécanismes mis en jeu. Deux études méthodologiques ont été menées en amont de cette étude clinique. La première visait à vérifier la stabilité des échantillons dans les conditions de transport imposées par l'étude princeps. Par ailleurs, les concentrations effondrées de lipoprotéines chez ces patients rendent difficile l'évaluation du statut en vitamine E par les simples dosages plasmatiques. Aussi, la seconde étude avait pour but d'établir les valeurs usuelles pour les concentrations en vitamine E dans les globules rouges et le tissu adipeux chez l'enfant sain comme outil d'aide au suivi des patients atteints d'hypocholestérolémie génétique. Grâce aux valeurs de référence établies dans ce travail, l'analyse de la vitamine E dans les globules rouges et le tissu adipeux permet de proposer une vue plus globale du statut en vitamine E chez ces patientsAbetalipoproteinemia (ABL) and chylomicron retention disease (CMRD) are rare recessive forms of hypobetalipoproteinemia characterized by an intestinal lipid malabsorption and a severe vitamin E deficiency leading to disabling neuro-ophtalmologic sequelae. Oral a- tocopherol supplementation with high doses has to be initiated as early as possible to prevent or halt progression of complications. The main aim of our work was to investigate the interest of tocofersolan, a water-soluble derivative of RRR-α-tocopherol, compared to a-tocopherol acetate in ABL and CMRD. In parallel, we investigated the mechanisms of absorption / secretion of tocofersolan and a- tocopheryl acetate on Caco2 cells for a better understanding of the mechanisms of their therapeutic efficacy. Two methodological studies were conducted prior to this clinical study. Firstly, we studied the stability of commonly measured vitamins and carotenoids in whole blood in the conditions of transport imposed by the clinical study. Secondly, we established the reference intervals for vitamin E concentrations in red blood cells and adipose tissue in healthy child as a tool to monitore treatment of children with ABL and CMRD with vitamin E. Indeed, the very reduced lipoprotein concentrations in these patients make difficult the assesment of vitamin E status based on plasma a-tocopherol concentrations. The references values established in this work allows us to propose a more comprehensive view of the vitamin E status in these patient

Validation multicentrique du dosage de la transferrine désialylée (CDT) par les méthodes %CDT TIA® et Tina Quant %CDT®

LILLE2-BU Santé-Recherche (593502101) / SudocSudocFranceF

Overview of the in vitro stability of commonly measured vitamins and carotenoids in whole blood

Background The pre-analytical stabilities of vitamins A, E, K, B1, B2, B6, B12, C, carotenoids and folates in whole blood were studied. The aim of this work was to provide clear and workable pre-analytical procedures specifying optimal delay before freezing for laboratories which perform themselves such analyses or which receive and transfer such specimens to referral laboratories.Methods The stability of vitamins was studied in whole blood at room temperature after light exposure up to 24h (vitamin C), 48h (vitamins A, E, B1, B2, B6 and carotenoids) and 72h (vitamins K, B12, red blood cell (RBC) and serum folates). Vitamin C stability after baseline acidification was analysed up to 48h. Changes observed were compared to a clinical cut-off defined as total change limit based on a combination of analytical performance and within-subject variation.Results Clinically and statistically significant changes occurred only in vitamins C (-22.5%), B6 (+9.9%) and serum folates (-16.8%) concentrations after 6, 24 and 48h, respectively. Vitamins A, E, K, B1, B2, B12, RBC folates and carotenoids showed good stability up to 48 or 72h. Vitamin C in acidified serum conserved at room temperature appeared unstable. The optimal condition for acidified vitamin C conservation was at less than -20?.Conclusion The majority of vitamins remain stable for up to 48h. Vitamin C quantification requires serum acidification followed by freezing as soon as possible. Freezing, respectively, within 12h and 24h for determination of plasma vitamin B6 and serum folates concentrations is recommended

Validation of Knock-Out Caco-2 TC7 Cells as Models of Enterocytes of Patients with Familial Genetic Hypobetalipoproteinemias

International audienceAbetalipoproteinemia (FHBL-SD1) and chylomicron retention disease (FHBL-SD3) are rare recessive disorders of lipoprotein metabolism due to mutations in MTTP and SAR1B genes, respectively, which lead to defective chylomicron formation and secretion. This results in lipid and fat-soluble vitamin malabsorption, which induces severe neuro-ophthalmic complications. Currently, treatment combines a low-fat diet with high-dose vitamin A and E supplementation but still fails in normalizing serum vitamin E levels and providing complete ophthalmic protection. To explore these persistent complications, we developed two knock-out cell models of FHBL-SD1 and FHBL-SD3 using the CRISPR/Cas9 technique in Caco-2/TC7 cells. DNA sequencing, RNA quantification and Western blotting confirmed the introduction of mutations with protein knock-out in four clones associated with i) impaired lipid droplet formation and ii) defective triglyceride (−57.0 ± 2.6% to −83.9 ± 1.6%) and cholesterol (−35.3 ± 4.4% to −60.6 ± 3.5%) secretion. A significant decrease in α-tocopherol secretion was also observed in these clones (−41.5 ± 3.7% to −97.2 ± 2.8%), even with the pharmaceutical forms of vitamin E: tocopherol-acetate and tocofersolan (α-tocopheryl polyethylene glycol succinate 1000). MTTP silencing led to a more severe phenotype than SAR1B silencing, which is consistent with clinical observations. Our cellular models thus provide an efficient tool to experiment with therapeutic strategies and will allow progress in understanding the mechanisms involved in lipid metabolism

Association between Peripheral Leptin and Adiponectin Levels and Cognitive Decline in Patients with Neurocognitive Disorders \textgreater= 65 Years

Background: There is evidence that adipokines have roles in brain functioning and cognitive decline. Objective: Assess the role of leptin and adiponectin levels in predicting changes in neuro-cognitive disorders (NCD). Methods: The study included 205 patients over 65 years of age presenting for a one-day hospitalization for current assessment of cognitive function. Peripheral blood leptin and adiponectin levels were measured at admission. Demographic variables, body mass index (BMI), and history of hypertension were also recorded. Cognitive function was assessed by the MiniMental State Examination (MMSE) at admission and at later scheduled visits over a median follow-up period of 14.5 months. Conventional univariate comparisons were made between diagnosis groups (Alzheimer's disease (AD), mild NCD, vascular/mixed dementia). Changes in MMSE scores over time were examined with regard to the above variables using a linear mixed model. Results: The mean BMI was significantly lower (by 2 kg/m(2) , p = 0.01) in patients with AD than in patients with either mildNCD or vascular/mixed dementia. Leptin levels were significantly higher (p = 0.043) and adiponectin levels significantly lower (p = 0.045) in patients with mild-NCD than in patients with major-NCD (AD or vascular/mixed dementia). However, the mixed model suggested no influence of the baseline levels of these two biomarkers on the course of cognitive decline. Conclusion: The present study confirms the associations between leptin and adiponectin and AD or AD-related disorders but did not confirm that these peptides may be used as predictive biomarkers of cognitive decline

Accuracies of serum and fecal S100 proteins (calprotectin and calgranulin C) to predict the response to TNF antagonists in patients with Crohn's disease

International audienceBACKGROUND: Calprotectin and S100A12 (calgranulin C) are markers of gut inflammation. The aim was to compare the usefulness of serum and fecal calprotectin (fCal) and S100A12 in assessing the response to anti-TNF and in predicting relapse under maintenance therapy in Crohn's diseases (CD). METHODS: Thirty-two consecutive patients with CD were treated with adalimumab or infliximab. All received an induction regimen followed by maintenance therapy with infliximab 5 mg/kg every 8 weeks or adalimumab 40 mg every other week and provided at week 0 and 14 fecal and blood samples for determination serum CRP, serum and fecal calprotectin and S100A12 levels. RESULTS: Clinical remission at week 14 (responders) was achieved in 21 patients and among them, 12 were still in steroid-free clinical remission at week 52. Median serum S100A12 and fCal concentrations significantly drop only in responders from week 0 to week 14 after induction, whereas serum calprotectin and fecal S100A12 levels failed to differ significantly. Fecal calprotectin levels at week 14 had the highest discriminant validity to predict clinical remission within 1 year after induction (area under the curve = 0.87) followed by fecal, serum S100A12, and serum calprotectin (area under the ROC curve = 0.70, 0.70, and 0.68, respectively). A cutoff of 82 mug/g for fCal at week 14 had a sensitivity and specificity of 93% and 75%, respectively, to predict clinical remission within 1 year of therapy. CONCLUSIONS: Serum S100A12 level and fCal are reliable markers associated with response to induction therapy with anti-TNF. Fecal calprotectin was the best for predicting clinical remission in CD under maintenance therapy

FGF19 and muscle architecture in older patients

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ROS Production and Distribution: A New Paradigm to Explain the Differential Effects of X-ray and Carbon Ion Irradiation on Cancer Stem Cell Migration and Invasion

Although conventional radiotherapy promotes the migration/invasion of cancer stem cells (CSCs) under normoxia, carbon ion (C-ion) irradiation actually decreases these processes. Unraveling the mechanisms of this discrepancy, particularly under the hypoxic conditions that pertain in niches where CSCs are preferentially localized, would provide a better understanding of the origins of metastases. Invasion/migration, proteins involved in epithelial-to-mesenchymal transition (EMT), and expression of MMP-2 and HIF-1α were quantified in the CSC subpopulations of two head-and-neck squamous cell carcinoma (HNSCC) cell lines irradiated with X-rays or C-ions. X-rays triggered HNSCC-CSC migration/invasion under normoxia, however this effect was significantly attenuated under hypoxia. C-ions induced fewer of these processes in both oxygenation conditions. The differential response to C-ions was associated with a lack of HIF-1α stabilization, MMP-2 expression, or activation of kinases of the main EMT signaling pathways. Furthermore, we demonstrated a major role of reactive oxygen species (ROS) in the triggering of invasion/migration in response to X-rays. Monte-Carlo simulations demonstrated that HO● radicals are quantitatively higher after C-ions than after X-rays, however they are very differently distributed within cells. We postulate that the uniform distribution of ROS after X-rays induces the mechanisms leading to invasion/migration, which ROS concentrated in C-ion tracks are unable to trigger