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Small-molecule metabolism has been extensively studied in the past decades, notably driven by the development of new pharmaceutical ingredients. The understanding of metabolism is critical to the anticipation of reactive metabolite formation in vivo that is often associated with toxicity. Electrochemistry has been proposed to simulate the oxidoreductive metabolism reaction catalyzed by cytochrome P450, a family of microsomal enzymes strongly involved in xenobiotic metabolism. The implementation of an electrochemical cell online with mass spectrometry allows for the fast formation and identification of the reaction end products. This study discusses the ability of the synthetic electrochemical approach to simulate a complex lactamization reaction that involves the formation of reactive metabolites. Aristolochic acid I was used as a model molecule to evaluate the ability of electrochemical simulation to generate nitroso, hydroxylamine, N-hydroxylactam, lactam, and nitrenium ion metabolites.

BackgroundMost adipokines are up-regulated with obesity and promote metabolic dysfunction, while few, like adiponectin, are down-regulated during adipose tissue expansion and probably protect against obesity-related disorders. High adiponectin is linked to low inflammation and insulin sensitivity. Similarly, apolipoprotein M (apoM) was recently identified as an adipokine for which the expression in adipose tissue is positively associated with metabolic health. Our aim was to compare circulating levels of apoM to those of adiponectin in overweight and obese individuals with respect to metabolic parameters and insulin sensitivity.MethodsAdiponectin and apoM were measured in a cross-sectional study including 169 overweight men and in a surgery-induced weight loss program including 13 obese patients of both sexes who underwent sleeve gastrectomy. Correlations between the homeostasis model assessment of insulin resistance (HOMA-IR) index, bioclinical parameters, adiponectin and apoM levels, and lifestyle habits were assessed using Spearman correlation coefficients. Multiple regression analyses of HOMA-IR were performed.ResultsIn overweight men, plasma adiponectin and apoM were lower in participants with diabetes. The apoM level did not correlate with that of adiponectin and was higher in individuals with dyslipidemia. Similar to adiponectin, apoM was negatively associated with HOMA-IR (r = −0.29), hs-CRP (r = −0.28) and HDL markers (HDL-C, r = 0.32; apoA-I, r = 0.32). Unlike adiponectin, apoM did not correlate with triglyceride levels but was positively associated with LDL markers (LDL-C, r = 0.27; apoB100, r = 0.20) and negatively with fat mass (r = −0.26) and age (r = −0.25). In multiple regression models, apoM was the only negative determinant of HOMA-IR, while adiponectin did not contribute to HOMA-IR variability. Accordingly, while sleeve gastrectomy improved insulin sensitivity, change in HOMA-IR at one year of follow-up was strongly negatively associated with change in the level of circulating apoM (r = -0.71) but not with change in the adiponectin level.ConclusionsBoth circulating apoM and adiponectin are negatively correlated with bioclinical variables associated with obesity, inflammation, and insulin resistance. Unexpectedly, apoM, but not adiponectin, was a negative determinant of HOMA-IR. We identified for the first time circulating apoM as a novel biomarker of insulin sensitivity.

Introduction: Obesity is associated with impaired learning, but the mechanisms underlying this cognitive dysfunction are poorly understood. Moreover, whether obesity-induced learning deficits show sexual dimorphism remains controversial. Females are believed to be protected from cognitive decline by oestrogens. These hormones enhance the expression of tryptophan hydroxylase 2, the rate-limiting enzyme in the transformation of tryptophan (Trp) into serotonin which plays a significant role in learning and memory. However, several learning-regulating compounds also arise from Trp metabolism through the kynurenine pathway (KP), including kynurenic acid (KA), xanthurenic acid (XA), and NAD+. The present study aimed to determine the involvement of the KP of Trp metabolism in the regulation of learning in control and obese female rats. Methods: The learning capabilities of control and obese rats were evaluated using the novel object recognition test. Trp and Trp-derived metabolites were quantified in the hippocampus and frontal cortex by ultra-performance liquid chromatography-tandem mass spectrometry. Results: Control rats in proestrus/oestrous performed better than their control mates in metestrus/dioestrus. Likewise, while control and obese rats in dioestrus/metestrus did not show differences in learning, obese rats in proestrus/oestrous displayed decreased memory capacity along with decreased Trp concentration and reduced KA, XA, and NAD+ production in the hippocampus. These neurochemical alterations were associated with impaired expression of mRNAs coding for key enzymes of the KP. Conclusion: The results presented here indicate that the deleterious effects of obesity on learning are closely related to the oestrous cycle and associated with an impairment of the KP of Trp metabolism.

SummaryGlioblastoma (GBM) are currently associated with a dismal prognosis due to therapeutic resistance. Within the diverse tumor subpopulations, Glioblastoma Stem-like Cells (GSC) have been involved in GBM recurrence. In our study, we demonstrated that these tumor cells can be identified through singular mitochondrial alternative metabolisms. Combining state-of-the-art metabolic studies and the development of a straightforward tumoroid model recapitulating key features of primary GBM cultures, we uncovered a significant use of α-ketoglutarate reductive carboxylation and pyruvate carboxylation in tumoroid GBM cells, catalyzed respectively by isocitrate dehydrogenase and pyruvate carboxylase enzymes. We demonstrated that these singular metabolic features are shared by GBM cells from the mesenchymal subtype and radiation-escaping cells, also involved in recurrence. Finally, we demonstrated that pyruvate carboxylation is required for GBM cell survival in hypoxic niches where glutamine is restricted. Thus, besides providing a new way to identify GSC, our study also opens new therapeutic strategy to limit GBM recurrence.

Background: NAFLD affects nearly 25% of the global population. Cardiovascular disease (CVD) is the most common cause of death among patients with NAFLD, in line with highly prevalent dyslipidemia in this population. Increased plasma triglyceride (TG)-rich lipoprotein (TRL) concentrations, an important risk factor for CVD, are closely linked with hepatic TG content. Therefore, it is of great interest to identify regulatory mechanisms of hepatic TRL production and remnant uptake in the setting of hepatic steatosis. Approach and Results: To identify liver-regulated pathways linking intrahepatic and plasma TG metabolism, we performed transcriptomic analysis of liver biopsies from two independent cohorts of obese patients. Hepatic encoding apolipoprotein F (APOF) expression showed the fourth-strongest negatively correlation with hepatic steatosis and the strongest negative correlation with plasma TG levels. The effects of adenoviral-mediated human ApoF (hApoF) overexpression on plasma and hepatic TG were assessed in C57BL6/J mice. Surprisingly, hApoF overexpression increased both hepatic very low density lipoprotein (VLDL)-TG secretion and hepatic lipoprotein remnant clearance, associated a similar to 25% reduction in plasma TG levels. Conversely, reducing endogenous ApoF expression reduced VLDL secretion in vivo, and reduced hepatocyte VLDL uptake by similar to 15% in vitro. Transcriptomic analysis of APOF-overexpressing mouse livers revealed a gene signature related to enhanced ApoB-lipoprotein clearance, including increased expression of Ldlr and Lrp1, among others. Conclusion: These data reveal a previously undescribed role for ApoF in the control of plasma and hepatic lipoprotein metabolism by favoring VLDL-TG secretion and hepatic lipoprotein remnant particle clearance.

Background: Mitochondrial dysfunction is associated with the development of type 2 diabetes (T2D). It is thus of clinical relevance to identify plasma biomarkers of mitochondrial dysfunction associated with the risk of T2D.ATPase inhibitory factor 1 (IF1) endogenously inhibits mitochondrial ATP synthase activity. Here, we analyzed association of the plasma IF1 level with markers of glucose homeostasis and with the conversion to new-onset diabetes (NOD) in individuals with prediabetes.Methods: In the IT-DIAB prospective study, the plasma level of IF1 was measured at baseline in 307 participants with prediabetes, defined as a moderately elevated fasting plasma glucose, i.e., 110–125 mg/dL (6.0–7.0 mmol/L). The primary outcome was the incidence of NOD, defined as the first fasting plasma glucose value ≥ 1.26 g/L (7.0 mmol/L) within five years of follow-up. Cross-sectional analysis of the IF1 level was also done in two independent interventional studies. Correlations between plasma IF1 and metabolic parameters at baseline were assessed by Spearman’s correlation coefficients, and the association with the risk of NOD was determined using Cox proportional‐hazards models.Results: In IT-DIAB, the mean IF1 plasma level was lower in participants who developed NOD than in those who did not (537 ± 248 versus 621 ± 313 ng/mL, p=0.01). The plasma IF1 level negatively correlated with clinical variables associated with obesity and insulin resistance, including the BMI (r = -0.20, p=0.0005) and HOMA-IR (r = -0.37, pConclusion: We identified for the first time the mitochondrial-related biomarker IF1 as being associated with the risk of T2D. As a biomarker, circulating IF1 can be considered to be a surrogate of mitochondrial energetics. IF1 can potentially be used to select patients for clinical trials of therapeutics that target mitochondrial function.

Lipoprotein(a) (Lp(a)) is a low-density lipoprotein-like particle containing apolipoprotein(a) (apo(a)) that increases the risk of atherosclerotic cardiovascular disease (ASCVD) in familial hypercholesterolemia (FH). Postprandial redistribution of apo(a) protein from Lp(a) to triglyceride-rich lipoproteins (TRLs) may also increase the atherogenicity of TRL particles. Omega-3 fatty acid (ω3FA) supplementation improves postprandial TRL metabolism in FH subjects. However, its effect on postprandial apo(a) metabolism has yet to be investigated.We carried out an 8-week open-label, randomized, crossover trial to test the effect of ω3FA supplementation (4 g/day) on postprandial apo(a) responses in FH patients following ingestion of an oral fat load. Postprandial plasma total and TRL-apo(a) concentrations were measured by liquid chromatography with tandem mass spectrometry, and the corresponding areas under the curve (AUCs) (0-10h) were determined using the trapezium rule.Compared with no ω3FA treatment, ω3FA supplementation significantly lowered the concentrations of postprandial TRL-apo(a) at 0.5 (-17.9%), 1 (-18.7%), 2 (-32.6%), and 3 h (-19.2%) (P＜0.05 for all). Postprandial TRL-apo(a) AUC was significantly reduced with ω3FA by 14.8% (P＜0.05). By contrast, ω3FA had no significant effect on the total AUCs of apo(a), apoC-III, and apoE (P＞0.05 for all). The decrease in postprandial TRL-apo(a) AUC was significantly associated with changes in the AUC of triglycerides (r=0.600; P ＜0.01) and apoB-48 (r=0.616; P＜0.01).Supplementation with ω3FA reduces postprandial TRL-apo(a) response to a fat meal in FH patients; this novel metabolic effect of ω3FA may have implications on decreasing the risk of ASCVD in patients with FH, especially in those with elevated plasma triglyceride and Lp(a) concentrations. However, the clinical implications of these metabolic findings require further evaluation in outcome or surrogate endpoint trials.

Maternal stress during pregnancy results in increased risk of developing psychiatric disorders in the offspring including anxiety, depression, schizophrenia, and autism. However, the mechanisms underlying this disease susceptibility remain largely to be determined. In this study, the involvement of the serotonin (5-HT) and kynurenine (KYN) pathways of tryptophan metabolism on the behavioral deficits induced by maternal stress during the late phase of gestation in mice was investigated. Adult offspring born to control or restraint-stressed dams were exposed to the elevated plus-maze and tail suspension tests. Metabolites of the KYN and 5-HT pathways were measured in the hippocampus and brainstem by ultra-performance liquid chromatography tandem mass spectrometry. Female, but not male, prenatally stressed (PNS) offspring displayed a depressive-like phenotype, mainly when in proestrus/diestrus, along with reduced hippocampal 5-HT levels and high 5-HT turnover rate in the hippocampus and brainstem. In contrast, male PNS mice showed enhanced anxiety-like behaviors and higher hippocampal and brainstem quinolinic acid levels compared to male offspring born to nonstressed dams. These results indicate that maternal stress affects the behavior and brain metabolism of tryptophan in the offspring in a sex-dependent manner and suggest that alterations in both the 5-HT and KYN pathways may underlie the emotional dysfunctions observed in individuals exposed to stress during in utero development.

International audience; Apolipoproteins govern lipoprotein metabolism and are promising biomarkers of metabolic and cardiovascular diseases. Unlike immunoassays, MS enables the quantification and phenotyping of multiple apolipoproteins. Hence, here, we aimed to develop a LC-MS/MS assay that can simultaneously quantitate 18 human apolipoproteins [A-I, A-II, A-IV, A-V, B48, B100, C-I, C-II, C-III, C-IV, D, E, F, H, J, L1, M, and (a)] and determined apoE, apoL1, and apo(a) phenotypes in human plasma and serum samples. The plasma and serum apolipoproteins were trypsin digested through an optimized procedure and peptides were extracted and analyzed by LC-MS/MS. The method was validated according to standard guidelines in samples spiked with known peptide amounts. The LC-MS/MS results were compared with those obtained with other techniques, and reproducibility, dilution effects, and stabilities were also assessed. Peptide markers were successfully selected for targeted apolipoprotein quantification and phenotyping. After optimization, the assay was validated for linearity, lower limits of quantification, accuracy (biases: -14.8% to 12.1%), intra-assay variability [coefficients of variation (CVs): 1.5-14.2%], and inter-assay repeatability (CVs: 4.1-14.3%). Bland-Altman plots indicated no major statistically significant differences between LC-MS/MS and other techniques. The LC-MS/MS results were reproducible over five repeated experiments (CVs: 1.8-13.7%), and we identified marked differences among the plasma and serum samples. The LC-MS/MS assay developed here is rapid, requires only small sampling volumes, and incurs reasonable costs, thus making it amenable for a wide range of studies of apolipoprotein metabolism. We also highlight how this assay can be implemented in laboratories.

International audience; Background: The benefits of parathyroidectomy on cardiovascular risk in primary hyperparathyroidism (PHPT) are controversial. This monocentric, observational, prospective study aimed to assess the effects of parathyroidectomy on glucose and lipid metabolism in classic or mild PHPT.Methods: Patients who underwent parathyroidectomy for classic (calcemia >2.85 mmol/L) or mild PHPT (calcemia ≤2.85 mmol/L) between 2016 and 2019 were included. A metabolic assessment was performed before and 1 year after parathyroidectomy. Patients with a history of diabetes were excluded.Results: Nineteen patients had classic and 120 had mild PHPT. Ninety-five percent were normocalcemic 6 months after surgery. Fasting plasma glucose and insulin levels decreased after parathyroidectomy in patients with mild PHPT (p < 0.001). HOMA-IR decreased after surgery in the overall population (p < 0.001), while plasma adiponectin concentrations increased in patients with both classic (p = 0.005) and mild PHPT (p < 0.001). Plasma triglyceride levels decreased significantly only in patients with classic PHPT (p = 0.021). Plasma PCSK9 levels decreased in patients with mild PHPT (p < 0.001).Conclusions: Parathyroidectomy for PHPT improves insulin resistance and decreases plasma triglyceride levels in classic PHPT and plasma PCSK9 levels in mild PHPT. Further studies are needed to better characterize the consequences of such metabolic risk factors' improvements on cardiovascular events.

Plasma lipids are carried within lipoproteins with various apolipoprotein content. This study evaluates the interest of measuring the apolipoproteins of circulating lipoproteins in breast cancer. Patients with early-stage breast cancer (n = 140) were included. Tumors differed by the expression of estrogen and progesterone receptor (HR− and HR+ for negative and positive expression) and the proliferation marker Ki-67 (≤20% or ≥30%). Apolipoprotein concentrations were determined in plasma, HDL and non-HDL fractions, and results are given in mg/dL, median (25th–75th). Patients did not differ in their plasma and lipoprotein lipid concentrations. HDL apoC-I and non-HDL apoC-II were reduced (1.34 (1.02–1.80) vs. 1.61 (1.32–2.04), p = 0.04; 0.31 (0.18–0.65) vs. 0.63 (0.39–1.02), p = 0.01; respectively), in RH-/high Ki-67 patients in comparison to RH-/low Ki-67 patients, while plasma apoD and HDL apoD were higher (3.24 (2.99–4.16) vs. 3.07 (2.39–3.51), p = 0.04; 2.74 (2.36–3.35) vs. 2.45 (2.01–2.99), p = 0.04; respectively). When RH+/high Ki-67 patients were compared with RH+/low Ki-67 patients, HDL apoC-I and HDL apoC-III were higher (1.56 (1.20–1.95) vs. 1.35 (1.10–1.62), p = 0.02; 2.80 (2.42–3.64) vs. 2.38 (1.69–2.96), p = 0.02; respectively). The distribution of exchangeable apolipoproteins, such as apoC-I, apoC-II, apoC-III, apoD, between lipoproteins is linked to the severity of breast cancer.

Objective: Gestational hypercholesterolemia concomitantly with a highly oxidative environment is associated with higher atherosclerosis in human and animal offspring. This work aimed to determine whether perinatal administration of a C-phycocyanin concentrate, a powerful antioxidant, can protect against atherosclerosis development in genetically hypercholesterolemic mice in adult life. Approach and Results: C-Phycocyanin was administered during gestation solely or gestation and lactation to apolipoprotein E-deficient mice. Male and female offspring were studied until 25 weeks old. Progenies born to supplemented mothers displayed significantly less atherosclerotic root lesions than control group in all groups excepted in male supplemented during gestation and lactation. Female born to supplemented mothers had a greater gallbladder total bile acid pool, lower secondary hydrophobic bile acid levels such as lithocholic acid, associated with less plasma trimethylamine N -oxide at 16 weeks old compared with control mice. Regarding male born to C-Phycocyanin administrated mothers, they expressed a higher high-density lipoprotein cholesterol level, more soluble bile acids such as β-muricholic acids, and a decreased plasma trimethylamine at 16 weeks old. Liver reduced-to-oxidized glutathione ratio were increased and liver gene expression of superoxide dismutase and glutathione peroxidase were significantly decreased in male born to gestational supplemented mothers. No difference in the composition of cecal microbiota was found between groups, regardless of sex. Conclusions: Our findings suggest a protective effect of perinatal antioxidant administration on atherosclerosis development in apolipoprotein E-deficient mice involving sex-specific mechanisms.

Background The identification of circulating biomarkers associated with the risk of type 2 diabetes (T2D) is useful for improving the current prevention strategies in the most at-risk patients. Here, we aimed to investigate the association of plasma apolipoprotein concentrations in prediabetes subjects with the incidence of new-onset T2D during follow-up. Methods In the IT-DIAB prospective study, 307 participants with impaired fasting glucose levels (fasting plasma glucose [FPG]: 110–125 mg/dL) were followed yearly for 5 years. The onset of T2D was defined as a first FPG value ≥ 126 mg/dL during follow-up. Apolipoprotein (apo)A-I, A-II, A-IV, B100, C-I, C-II, C-III, C-IV, D, E, F, H, J, L1, M, and (a) plasma concentrations were determined by mass spectrometry. Correlations between apolipoproteins and metabolic parameters at baseline were assessed by Spearman’s coefficients. Kaplan–Meier curves were drawn using a ternary approach based on terciles and incident T2D. The association between plasma apolipoproteins concentrations and the incidence of T2D was determined using Cox proportional-hazards models. Results During a median follow-up of 5-year, 115 participants (37.5%) developed T2D. After adjustment for age, sex, body mass index, FPG, HbA1c, and statin use, the plasma levels of apoC-I, apoC-II, apoC-III, apoE, apoF, apoH, apoJ, and apoL1 were positively associated with a high risk for T2D. After further adjustment for plasma triglycerides, only apoE (1 SD natural-log-transformed hazard ratio: 1.28 [95% confidence interval: 1.06; 1.54]; p = 0.010), apoF (1.22 [1.01; 1.48]; p = 0.037), apoJ (1.24 [1.03; 1.49]; p = 0.024), and apoL1 (1.26 [1.05; 1.52]; p = 0.014) remained significantly associated with the onset of T2D. Kaplan–Meier survival curves also showed that the lower third of plasma apoE levels (p = 0.002) compared to the middle and upper thirds. Conclusions The plasma apoE levels are positively associated with the risk of T2D in prediabetes subjects, independently of traditional risk factors. The possible associations of apoF, apoJ, and apoL1 with T2D risk also pave the way for further investigations. Trial registration This trial was registered at clinicaltrials.gov as NCT01218061 and NCT01432509

Bariatric surgery improves obesity-related comorbidities. Methylarginines are biomarkers of cardiometabolic risk, liver steatosis, and insulin resistance. Here, we aimed to investigate methylarginines in obese patients undergoing bariatric surgery and compared them to age- and sex-matched healthy subjects. Thirty-one obese patients who underwent bariatric surgery and 31 healthy individuals were used for this retrospective study. The basal serum methylarginine levels were determined in the healthy individuals and the obese patients, before surgery and 6 and 12 months after surgery, by mass spectrometry. Compared with the healthy individuals, the obese patients displayed elevated monomethylarginine (mean change: +95%, p &lt, 0.001), asymmetric-dimethylarginine (+105%, p &lt, 0.001), symmetric-dimethylarginine (+25%, p = 0.003), and dimethylguanidino valerate (+32%, p = 0.008) concentrations. Bariatric surgery durably reduced the body mass index by 28% (12 months, 95%CI: 24–33, p = 0.002) and improved plasma lipids, insulin resistance, and liver function. Bariatric surgery reduced the serum levels of monomethylarginine and asymmetric-dimethylarginine by 12% (95%CI: 6–17) and 36% (95%CI: 27–45) (12 months, p = 0.003), respectively, but not symmetric-dimethylarginine or dimethylguanidino valerate. The monomethylarginine and asymmetric-dimethylarginine concentrations were strongly correlated with markers of dyslipidemia, insulin resistance, and a fatty liver. Serum dimethylguanidino valerate was primarily correlated with glycemia and renal function, whereas serum symmetric-dimethylarginine was almost exclusively associated with renal function. In conclusion, the monomethylarginine and asymmetric-dimethylarginine levels are efficiently decreased by bariatric surgery, leading to a reduced atherogenic profile in obese patients. Methylarginines follow different metabolic patterns, which could help for the stratification of cardiometabolic disorders in obese patients.

New methods for chemo-selective modifications of peptides and native proteins are important in chemical biology and for the development of therapeutic conjugates. Less abundant and uncharged amino-acid residues are interesting targets to form less heterogeneous conjugates and preserve biological functions. Phenylurazole (PhUr), N-methylphenylurazole (NMePhUr) and N-methylluminol (NMeLum) derivatives were described as tyrosine (Y) anchors after chemical or enzymatic oxidations. Recently, we developed the first electrochemical Y-bioconjugation method coined eY-click to activate PhUr in biocompatible media. In this work, we assessed the limitations, benefits and relative efficiencies of eY-click conjugations performed with a set of PhUr, NMePhUr and NMeLum derivatives. Results evidenced a high efficiency of NMeLum that showed a complete Y-chemoselectivity on polypeptides and biologically relevant proteins after soft electrochemical activation. Side reactions on nucleophilic or heteroaromatic amino-acids such as lysine or tryptophan were never observed during mass spectrometry analysis. Myoglobine, bovine serum albumin, a plant mannosidase, glucose oxidase and the therapeutically relevant antibody trastuzumab were efficiently labelled with a fluorescent probe in a two-step approach combining eY-click and strain-promoted azide–alkyne cyclization (SPAAC). The proteins conserved their structural integrity as observed by circular dichroism and the trastuzumab conjugate showed a similar binding affinity for the natural HER2 ligand as shown by bio-layer interferometry. Compared to our previously described protocol with PhUr, eY-click with NMeLum species showed faster reaction kinetics, higher (complete) Y-chemoselectivity and reactivity, and offers the interesting possibility of the double tagging of solvent-exposed Y., We assessed the relative efficiencies of tyrosine anchors in the electrochemical conjugation of peptides and proteins. Luminol derivatives showed faster reaction kinetics, complete tyrosine-chemoselectivity, and possible double modification.

International audience; Background and aims: Proprotein Convertase Subtilisin Kexin Type 9 (PCSK9) is an endogenous inhibitor of the LDL receptor (LDLR). Mendelian randomization studies suggest that PCSK9 deficiency increases diabetes risk, but the underlying mechanisms remain unknown. The aim of our study was to investigate whether PCSK9 or its inhibition may modulate beta cell function.Methods: We assessed PCSK9 and insulin colocalization in human pancreatic sections by epifluorescent and confocal microscopy. We also investigated the expression and the function of PCSK9 in the human EndoC-8H1 beta cell line, by ELISA and flow cytometry, respectively. PCSK9 was inhibited with Alirocumab or siRNA. LDLR expression and LDL uptake were assessed by flow cytometry.Results: PCSK9 was expressed and secreted from beta cells isolated from human pancreas as well as from EndoC-8H1 cells. PCSK9 secretion was enhanced by statin treatment. Recombinant PCSK9 decreased LDLR abundance at the surface of these cells, an effect abrogated by Alirocumab. Alirocumab as well as PCSK9 silencing increased LDLR expression at the surface of EndoC-8H1 cells. Neither exogenous PCSK9, nor Alirocumab, nor PCSK9 silencing significantly altered glucose-stimulated insulin secretion (GSIS) from these cells. High-low density lipoproteins (LDL) concentrations decreased GSIS, but the addition of PCSK9 or its inhibition did not modulate this phenomenon.Conclusions: While PCSK9 regulates LDLR abundance in beta cells, inhibition of exogenous or endogenous PCSK9 does not appear to significantly impact insulin secretion. This is reassuring for the safety of PCSK9 inhibitors in terms of beta cell function.

AIMS Lipoprotein (a) [Lp(a)] is a lipoprotein species causatively associated with atherosclerosis. Unlike statins, PCSK9 inhibitors (PCSK9i) reduce Lp(a), but this reduction is highly variable. Levels of Lp(a) are chiefly governed by the size of its signature protein, apolipoprotein (a) [apo(a)]. Whether this parameter determines some of the reduction in Lp(a) induced by PCSK9i remains unknown. We aimed to investigate if the Lp(a) lowering efficacy of PCSK9i is modulated by the size of apo(a), which is genetically determined by the variable number of KIV domains present on that protein. METHODS AND RESULTS The levels of Lp(a) and the size of apo(a) were assessed in plasma samples from 268 patients before and after treatment with PCSK9i. Patients were recruited at the Outpatient Lipid Clinic of the Charite Hospital (Berlin) between 2015 and 2020. They were hypercholesterolemic at very high CVD risk with LDL-cholesterol levels above therapeutic targets despite maximally tolerated lipid-lowering therapy. Patients received either Alirocumab (75 or 150 mg) or Evolocumab (140 mg) every 2 weeks. Apo(a), apoB100, and apoE concentrations as well as apoE major isoforms were determined by liquid chromatography high-resolution mass spectrometry. Apo(a) isoforms sizes were determined by Western Blot. PCSK9i sharply reduced LDL-cholesterol (-57%), apoB100 (-47%) and Lp(a) (-36%). There was a positive correlation between the size of apo(a) and the relative reduction in Lp(a) induced by PCSK9i (r = 0.363, p = 0.0001). The strength of this association remained unaltered after adjustment for baseline Lp(a) levels and all other potential confounding factors. In patients with two detectable apo(a) isoforms, there was also a positive correlation between the size of apo(a) and the reduction in Lp(a), separately for the smaller (r = 0.350, p = 0.0001) and larger (r = 0.324, p = 0.0003) isoforms. The relative contribution of the larger isoform to the total concentration of apo(a) was reduced from 29% to 15% (p

The lipid profile has not been fully investigated in individuals with peripheral artery disease (PAD). We aimed to evaluate the relationship between plasma concentrations of lipoproteins and the prevalence of lower-limb PAD at baseline and its incidence during follow-up in people with type 2 diabetes. Plasma concentrations of total cholesterol, HDL-cholesterol, triacylglycerol and apolipoprotein (Apo) A-I, ApoA-II, ApoB-100 and Apo(a) were measured at baseline using colorimetric or MS methods in the SURDIAGENE cohort. Total cholesterol/HDL-cholesterol ratio, non-HDL-cholesterol and LDL-cholesterol were estimated using computation formulas. Logistic and Cox proportional hazard regression models were fitted to estimate OR or HR, with related 95% CI, for baseline prevalence or incidence of major PAD (lower-limb amputation or requirement of revascularisation) during follow-up by increasing lipoprotein tertiles, after adjustment for key confounders. Among 1468 participants (women 42%, mean ± SD age 65 ± 11 years, duration of diabetes 14 ± 10 years at baseline), 129 (8.8%) had a baseline history of major PAD. Major PAD was less prevalent at baseline in the highest (vs lowest) tertile of HDL-cholesterol (OR 0.42 [95% CI 0.26, 0.71], p = 0.001) and ApoA-I (OR 0.39 [95% CI 0.23, 0.67], p = 0.0007), and more frequent in the highest tertile of total cholesterol/HDL-cholesterol ratio (OR 1.95 [95% CI 1.18, 3.24], p = 0.01). Among 1339 participants without a history of PAD at baseline, incident PAD occurred in 97 (7.2%) during a median (25th–75th percentile) duration of follow-up of 7.1 (4.4–10.7) years, corresponding to 9685 person-years and an incidence rate of 9.8 (95% CI 8.0, 12.0) per 1000 person-years. The risk of incident PAD was lower in the top (vs bottom) tertile of HDL-cholesterol (HR 0.54 [95% CI 0.30, 0.95], p = 0.03) or ApoA-I (HR 0.50 [95% CI 0.28, 0.86], p = 0.01) and higher in the top tertile of total cholesterol/HDL-cholesterol ratio (HR 2.81 [95% CI 1.61, 5.04], p = 0.0002) and non-HDL-cholesterol (HR 1.80 [95% CI 1.06, 3.12], p = 0.03). We reported independent associations between HDL-cholesterol, ApoA-I, total cholesterol/HDL-cholesterol ratio or non-HDL-cholesterol and the prevalence or the incidence of major PAD in people with type 2 diabetes. Our findings provide a picture of lipoprotein profile in people with type 2 diabetes.

International audience; Proprotein convertase subtilisin/kexin type 9 (PCSK9) promotes lysosomal degradation of the LDL receptor and is a key regulator of cholesterol metabolism. After the liver, the small intestine is the second organ that highly expresses PCSK9. However, the small intestine's ability to secrete PCSK9 remains a matter of debate. While liver-specific PCSK9-deficient mice present no PCSK9 in systemic blood, human intestinal Caco-2 cells can actively secrete PCSK9. This raises the possibility for active intestinal secretion via the portal blood. Here, we aimed to determine whether enterocytes can secrete PCSK9 using in vitro, ex vivo, and in vivo approaches. We first observed that PCSK9 secretion from Caco-2 cells was biphasic and dependent on Caco-2 maturation status. Transcriptional analysis suggested that this transient reduction in PCSK9 secretion might be due to loss of SREBP2-mediated transcription of PCSK9. Consistently, PCSK9 secretion was not detected ex vivo in human or mouse intestinal biopsies mounted in Ussing chambers. Finally, direct comparison of systemic versus portal blood PCSK9 concentrations in WT or liver-specific PCSK9-deficient mice confirmed the inability of the small intestine to secrete PCSK9 into the portal compartment. Altogether, our data demonstrate that mature enterocytes do not secrete PCSK9 and reinforce the central role of the liver in the regulation of the concentration of circulating PCSK9 and consequently of cellular LDL receptors.

International audience; ATPase inhibitory factor 1 (IF1) is a 9.5 kDa protein that binds to mitochondrial and plasma membrane ATP synthase and selectively inhibits ATP hydrolysis. Recently, IF1 was identified in systemic circulation in humans. IF1 appeared as an independent determinant of HDL-cholesterol with lower levels in coronary heart disease (CHD) patients. Moreover, IF1 was also found to negatively associate with mortality in these patients, supporting the notion that circulating IF1 could be a promising biomarker of cardiovascular disease. However, in previous studies, IF1 was quantified by a non-standardized competitive enzyme-linked immunosorbent assay (ELISA). Herein, we have validated a liquid chromatography-tandem mass spectrometry method (LC-MS/MS) enabling the accurate quantification of IF1 in human plasma. Plasma IF1 was trypsin-digested through an optimized procedure before LC-MS/MS analysis. The method was successfully validated over 4 independent experiments into the range of 100-1500 ng/mL. Intraand inter-assay variation coefficients had never exceeded 14.2% and accuracy ranged between 95% and 102% for the selected EAGGAFGK peptide marker. Subsequently, the results of the LC-MS/MS method were compared with those obtained using ELISA in 204 individuals from the GENES study. We found that IF1 plasma levels obtained using both techniques were strongly correlated (r = 0.89, p < 0.0001), while the Bland-Altman plot did not indicate any major statistically significant differences. To clinically validate LC-MS/MS, we confirmed the positive correlation between IF1 plasma levels and HDL-cholesterol (r = 0.38, p < 0.0001). Besides, we found lower IF1 plasma levels in CHD patients compared to controls (431 +/- 132 ng/mL and 555 +/- 173 ng/mL, respectively; p < 0.0001). Hence, it can be concluded that the presented LC-MS/MS analytical method provides a highly specific strategy for IF1 quantification in human plasma and could be proposed as a reference method.

The aim of this study was to compare the kinetics of apolipoprotein (apo)A-I during fed and fasted states in humans, and to determine to what extent the intestine contributes to apoA-I production. A stable isotope study was conducted to determine the kinetics of apoA-I in preβ1 high-density lipoprotein (HDL) and α-HDL. Six healthy male subjects received a constant intravenous infusion of 2H3-leucine for 14 h. Subjects in the fed group also received small hourly meals. Blood samples were collected hourly during tracer infusion and then daily for 4 days. Tracer enrichments were measured by mass spectrometry and then fitted to a compartmental model using asymptotic plateau of very-low-density lipoprotein (VLDL) apoB100 and triglyceride-rich lipoprotein (TRL) apoB48 as estimates of hepatic and intestinal precursor pools, respectively. The clearance rate of preβ1-HDL-apoA-I was lower in fed individuals compared with fasted subjects (p 1-HDL. Total apoA-I synthesis was not significantly increased in fed subjects. Hepatic production was not significantly different between the fed group (17.17 ± 2.75 mg/kg/day) and the fasted group (18.67 ± 1.69 mg/kg/day). Increase in intestinal apoA-I secretion in fed subjects was 2.20 ± 0.61 mg/kg/day. The HDL-apoA-I kinetics were similar in the fasted and fed groups, with 13% of the total apoA-I originating from the intestine with feeding.

The lipid profile has not been fully investigated in individuals with peripheral artery disease (PAD). We aimed to evaluate the relationship between plasma concentrations of lipoproteins and the prevalence of lower-limb PAD at baseline and its incidence during follow-up in people with type 2 diabetes.Plasma concentrations of total cholesterol, HDL-cholesterol, triacylglycerol and apolipoprotein (Apo) A-I, ApoA-II, ApoB-100 and Apo(a) were measured at baseline using colorimetric or MS methods in the SURDIAGENE cohort. Total cholesterol/HDL-cholesterol ratio, non-HDL-cholesterol and LDL-cholesterol were estimated using computation formulas. Logistic and Cox proportional hazard regression models were fitted to estimate OR or HR, with related 95% CI, for baseline prevalence or incidence of major PAD (lower-limb amputation or requirement of revascularisation) during follow-up by increasing lipoprotein tertiles, after adjustment for key confounders.Among 1468 participants (women 42%, mean ± SD age 65 ± 11 years, duration of diabetes 14 ± 10 years at baseline), 129 (8.8%) had a baseline history of major PAD. Major PAD was less prevalent at baseline in the highest (vs lowest) tertile of HDL-cholesterol (OR 0.42 [95% CI 0.26, 0.71], p = 0.001) and ApoA-I (OR 0.39 [95% CI 0.23, 0.67], p = 0.0007), and more frequent in the highest tertile of total cholesterol/HDL-cholesterol ratio (OR 1.95 [95% CI 1.18, 3.24], p = 0.01). Among 1339 participants without a history of PAD at baseline, incident PAD occurred in 97 (7.2%) during a median (25th-75th percentile) duration of follow-up of 7.1 (4.4-10.7) years, corresponding to 9685 person-years and an incidence rate of 9.8 (95% CI 8.0, 12.0) per 1000 person-years. The risk of incident PAD was lower in the top (vs bottom) tertile of HDL-cholesterol (HR 0.54 [95% CI 0.30, 0.95], p = 0.03) or ApoA-I (HR 0.50 [95% CI 0.28, 0.86], p = 0.01) and higher in the top tertile of total cholesterol/HDL-cholesterol ratio (HR 2.81 [95% CI 1.61, 5.04], p = 0.0002) and non-HDL-cholesterol (HR 1.80 [95% CI 1.06, 3.12], p = 0.03).We reported independent associations between HDL-cholesterol, ApoA-I, total cholesterol/HDL-cholesterol ratio or non-HDL-cholesterol and the prevalence or the incidence of major PAD in people with type 2 diabetes. Our findings provide a picture of lipoprotein profile in people with type 2 diabetes. Graphical abstract.

International audience; Lipoprotein(a) (Lp[a]) is the most common genetically inherited risk factor for cardiovascular disease. Many aspects of Lp(a) metabolism remain unknown. We assessed the uptake of fluorescent Lp(a) in primary human lymphocytes as well as Lp(a) hepatic capture in a mouse model in which endogenous hepatocytes have been ablated and replaced with human ones. Modulation of LDLR expression with the PCSK9 inhibitor alirocumab did not alter the cellular or the hepatic uptake of Lp(a), demonstrating that the LDL receptor is not a major route for Lp(a) plasma clearance. These results have clinical implications because they underpin why statins are not efficient at reducing Lp(a). (C) 2020 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation.

International audience; The actual protective mechanisms underlying cardioprotection with remote ischemic conditioning (RIC) remain unclear. Recent data suggest that RIC induces kynurenine (KYN) and kynurenic acid synthesis, two metabolites derived from tryptophan (TRP), yet a causal relation between TRP pathway and RIC remains to be established. We sought to study the impact of RIC on the levels of TRP and its main metabolites within tissues, and to assess whether blocking kynurenine (KYN) synthesis from TRP would inhibit RIC-induced cardioprotection. In rats exposed to 40-min coronary occlusion and 2-h reperfusion, infarct size was significantly smaller in RIC-treated animals (35.7 ± 3.0% vs. 46.5 ± 2.2%, p = 0.01). This protection was lost in rats that received 1-methyl-tryptophan (1-MT) pretreatment, an inhibitor of KYN synthesis from TRP (infarct size = 46.2 ± 5.0%). Levels of TRP and nine compounds spanning its metabolism through the serotonin and KYN pathways were measured by reversed-phase liquid chromatography–tandem mass spectrometry in the liver, heart, and limb skeletal muscle, either exposed or not to RIC. In the liver, RIC induced a significant increase in xanthurenic acid, nicotinic acid, and TRP. Likewise, RIC increased NAD-dependent deacetylase sirtuin activity in the liver. Pretreatment with 1-MT suppressed the RIC-induced increases in NAD-dependent deacetylase sirtuin activity. Altogether, these findings indicate that RIC mechanism is dependent on TRP–KYN pathway activation.

Objective: To clarify the association between PCSK9 (proprotein convertase subtilisin/kexin type 9) and Lp(a) (lipoprotein [a]), we studied Lp(a) kinetics in patients with loss-of-function and gain-of-function PCSK9 mutations and in patients in whom extended-release niacin reduced Lp(a) and PCSK9 concentrations. Approach and Results: Six healthy controls, 9 heterozygous patients with familial hypercholesterolemia (5 with low-density lipoprotein receptor [ LDLR ] mutations and 4 with PCSK9 gain-of-function mutations) and 3 patients with heterozygous dominant-negative PCSK9 loss-of-function mutations were included in the preliminary study. Eight patients were enrolled in a second study assessing the effects of 2 g/day extended-release niacin. Apolipoprotein kinetics in VLDL (very-low-density lipoprotein), LDL (low-density lipoprotein), and Lp(a) were studied using stable isotope techniques. Plasma Lp(a) concentrations were increased in PCSK9 -gain-of-function and familial hypercholesterolemia- LDLR groups compared with controls and PCSK9 -loss-of-function groups (14±12 versus 5±4 mg/dL; P =0.04), but no change was observed in Lp(a) fractional catabolic rate. Subjects with PCSK9 -loss-of-function mutations displayed reduced apoE (apolipoprotein E) concentrations associated with a VLDL-apoE absolute production rate reduction. Lp(a) and VLDL-apoE absolute production rates were correlated ( r =0.50; P r =0.96; P r =0.83; P =0.015). In contrast, PCSK9 reduction (−35%; P =0.008) was only correlated with that of VLDL-apoE absolute production rate ( r =0.79; P =0.028). Conclusions: VLDL-apoE production could determine Lp(a) production and/or assembly. As PCSK9 inhibitors reduce plasma apoE and Lp(a) concentrations, apoE could be the link between PCSK9 and Lp(a).

In addition to be a primary risk factor for type 2 diabetes and cardiovascular disease, obesity is associated with learning disabilities. Here we examined whether a dysregulation of the kynurenine pathway (KP) of tryptophan (Trp) metabolism might underlie the learning deficits exhibited by obese individuals. The KP is initiated by the enzymatic conversion of Trp into kynurenine (KYN) by indoleamine 2,3-dioxygenase (IDO). KYN is further converted to several signaling molecules including quinolinic acid (QA) which has a negative impact on learning. Wistar rats were fed either standard chow or made obese by exposure to a free choice high-fat high-sugar (fcHFHS) diet. Their learning capacities were evaluated using a combination of the novel object recognition and the novel object location tasks, and the concentrations of Trp and KYN-derived metabolites in several brain regions determined by ultra-performance liquid chromatography-tandem mass spectrometry. Male, but not female, obese rats exhibited reduced learning capacity characterized by impaired encoding along with increased hippocampal concentrations of QA, Xanthurenic acid (XA), Nicotinamide (Nam), and oxidized Nicotinamide Adenine Dinucleotide (NAD+). In contrast, no differences were detected in the serum levels of Trp or KP metabolites. Moreover, obesity enhanced the expression in the hippocampus and frontal cortex of kynurenine monooxygenase (KMO), an enzyme involved in the production of QA from kynurenine. QA stimulates the glutamatergic system and its increased production leads to cognitive impairment. These results suggest that the deleterious effects of obesity on cognition are sex dependent and that altered KP metabolism might contribute to obesity-associated learning disabilities.

Objective Even though trimethylamine N-oxide (TMAO) has been demonstrated to interfere with atherosclerosis and diabetes pathophysiology, the association between TMAO and major adverse cardiovascular events (MACE) has not been specifically established in type 2 diabetes (T2D). Research Design and Methods We examined the association of plasma TMAO concentrations with MACE and all-cause mortality in a single-center prospective cohort of consecutively recruited patients with T2D. Results The study population consisted in 1463 SURDIENE participants (58% men), aged 65 ± 10 years. TMAO concentrations were significantly associated with diabetes duration, renal function, high-density lipoprotein cholesterol, soluble tumor necrosis factor receptor 1 (sTNFR1) concentrations (R2 = 0.27) and were significantly higher in patients on metformin, even after adjustment for estimated glomerular filtration rate (eGFR): 6.7 (8.5) vs 8.5 (13.6) µmol/L, respectively (PeGFR-adjusted = 0.0207). During follow-up (median duration [interquartile range], 85 [75] months), 403 MACE and 538 deaths were registered. MACE-free survival and all-cause mortality were significantly associated with the quartile distribution of TMAO concentrations, patients with the highest TMAO levels displaying the greatest risk of outcomes (P Conclusions We revealed an association between higher TMAO concentrations and increased risk of MACE and all-cause mortality, thereby opening some avenues on the role of dysbiosis in cardiovascular risk, in T2D patients.

Therapeutic antibodies targeting proprotein convertase subtilisin kexin type 9 (PCSK9) (e.g. alirocumab) lower low-density lipoprotein cholesterol (LDL-C) and lipoprotein (a) [Lp(a)] levels in clinical trials. We recently showed that PCSK9 enhances apolipoprotein(a) [apo(a)] secretion from primary human hepatocytes but does not affect Lp(a) cellular uptake. Here, we aimed to determine how PCSK9 neutralization modulates Lp(a) levels in vivo. Six nonhuman primates (NHP) were treated with alirocumab or a control antibody (IgG1) in a crossover protocol. After the lowering of lipids reached steady state, NHP received an intravenous injection of [2H3]-leucine, and blood samples were collected sequentially over 48 h. Enrichment of apolipoproteins in [2H3]-leucine was assessed by liquid chromatography–tandem mass spectrometry (LC–MS/MS). Kinetic parameters were calculated using numerical models with the SAAMII software. Compared with IgG1, alirocumab significantly reduced total cholesterol (TC) (−28%), LDL-C (−67%), Lp(a) (−56%), apolipoprotein B100 (apoB100) (−53%), and apo(a) (−53%). Alirocumab significantly increased the fractional catabolic rate of apoB100 (+29%) but not that of apo(a). Conversely, alirocumab sharply and significantly reduced the production rate (PR) of apo(a) (−42%), but not significantly that of apoB100, compared with IgG1, respectively. In line with the observations made in human hepatocytes, the present kinetic study establishes that PCSK9 neutralization with alirocumab efficiently reduces circulating apoB100 and apo(a) levels by distinct mechanisms: apoB primarily by enhancing its catabolism and apo(a) primarily by lowering its production.

Introduction et but de l’etude Selon le CIRC, plus de 10 % des cancers seraient lies a une alimentation desequilibree et un surpoids. La localisation mammaire est la plus frequente chez la femme et concerne chaque annee, en France, pres de 50 000 patientes. Notre etude a pour objectif de clarifier le role des acides gras omega 3 sur la severite de la pathologie mammaire, selon la nature des lipoproteines qui les transportent. Materiel et methodes L’etude a ete realisee chez des patientes atteintes de pathologie mammaire cancereuse (n = 100, CRB-Tumorotheque -ICO) se differenciant par leur index de proliferation (KI67 30 % ou Prolif + ). Les caracteristiques clinicobiologiques des patientes ont ete collectees. Apolipoproteines et acides gras omega3 seriques ont ete quantifies par LC-MS/MS apres separation des lipoproteines contenant l’apo B (LpB) ou ne la contenant pas (LpA). Les criteres principaux de l’etude ont fait l’objet d’une analyse univariee par regression logistique sur les 2 groupes de patientes, exprimes en mediane [25e–75e], OR [5e–95e]. Resultats et analyse statistique Les patientes sont majoritairement atteintes de Carcinome Infiltrant de Type Non Specifique ou CITNS (98 %), le groupe Prolif- etant significativement plus âge (63,8 ans [43–79] vs 55,4 ans [27–82]; p Conclusion Les taux seriques d’EPA des lipoparticules contenant l’apolipoproteine B (VLDL et LDL) varient selon la severite de la pathologie cancereuse mammaire avec des taux plus eleves dans les situations les moins pejoratives. Cette etude preliminaire suggere donc un effet protecteur specifique de certains AG omega3 transportes par des lipoparticules specifiques. Une confirmation de ces observations cliniques est envisagee a travers une approche mecanistique in vitro.

International audience; Background/objectives Maternal obesity is associated with increased risk of obesity and other symptoms of the metabolic syndrome in the offspring. Nevertheless, the molecular mechanisms and cellular factors underlying this enhanced disease susceptibility remain to be determined. Here, we aimed at identifying changes in plasma lipids in offspring of obese mothers that might underpin, and serve as early biomarkers of, their enhanced metabolic disease risk. Subjects/methods We performed a longitudinal lipidomic profiling in plasma samples from normal weight, overweight, and obese pregnant women and their children that participated in the Prenatal Omega-3 Fatty Acid Supplementation, Growth, and Development trial conducted in Mexico. At recruitment women were aged between 18 and 35 years and in week 18–22 of pregnancy. Blood samples were collected at term delivery by venipuncture from mothers and from the umbilical cord of their newborns and from the same infants at 4 years old under non-fasting conditions. Lipidomic profiling was done using ultra-performance liquid chromatography high-resolution mass spectrometry. Results Analysis of the lipidomic data showed that overweight and obese mothers exhibited a significant reduction in the total abundance of ceramides (Cer) in plasma, mainly of Cer (d18:1/20:0), Cer (d18:1/22:0), Cer (d18:1/23:0), and Cer (d18:1/24:0), compared with mothers of normal body weight. This reduction was confirmed by the direct quantification of these and other ceramide species. Similar quantitative differences in the plasma concentration of Cer (d18:1/22:0), Cer (d18:1/23:0), and Cer (d18:1/24:0), were also found between 4-year-old children of overweight and obese mothers compared with children of mothers of normal body weight. Noteworthy, children exhibited equal daily amounts of energy and food intake independently of the BMI of their mothers. Conclusions Maternal obesity results in long-lasting changes in plasma ceramides in the offspring suggesting that these lipids might be used as early predictors of metabolic disease risk due to maternal obesity.

International audience; There are 3 isoforms of apolipoprotein E (apo E) in humans (ε2, ε3, and ε4). They differ by single amino acid substitutions that variably affect their affinity for the low-density lipoprotein receptor (LDLR) and for the LDLR-related protein (LRP1), with ε2 having the weakest binding to these receptors (1). The plasma levels of lipoprotein(a) [Lp(a)], a highly atherogenic LDL-like lipoprotein species, are influenced by the polymorphism of apo E, with ε2/ε2 and ε4/ε4 carriers presenting with the lowest and highest Lp(a) plasma concentrations, respectively (1).

Non-alcoholic steatohepatitis (NASH) is characterized by an excess of lipids and oxidative stress in the liver. Spirulina was reported to possess hypolipemic and antioxidative effects and might counteract NASH development. C57Bl/6J mice were fed a western diet (WD) during 25 weeks with or without spirulina liquid extract (SLE) at 2 different doses (WDS1 and WDS2 groups) in drinking water. Liver histology, inflammation, and oxidative stress were assessed as well as glucose tolerance status, lipid metabolism, and gallbladder bile acid profile. WDS2 gained significantly less weight than WD. Liver weight-to-body weight ratio and plasma alanine aminotransferase were significantly lower in WDS2 mice. A reduced liver fibrosis and NF&kappa, Bp65 protein expression were measured in the supplemented group as a lower accumulation of superoxide anion, nitric oxide, and thiobarbituric reactive substances. WDS2 mice showed also a preserved glucose tolerance, a strong decrease of plasma cholesterol, and a significant increase of gallbladder ursodeoxycholic acid and &beta, muricholic acid. Our findings demonstrate a protective effect of SLE against WD induced NASH that is related to less inflammation and oxidative stress, a preserved glucose tolerance, and less hepatotoxic bile acid profile.