Project description:The recent characterization of functional brown adipose tissue in adult humans has opened new perspectives for regulation of energy expenditure with respect to obesity and diabetes. Furthermore, dietary recommendations have taken into account the insufficient dietary intake of ω3 PUFAs and the concomitant excessive intake of ω6 PUFA associated with the occurrence of overweight/obesity. We aimed to study whether ω3 PUFAs could play a role in the recruitment and function of energy-dissipating brown/brite adipocytes. We show that ω3 PUFA supplementation has a beneficial effect on the thermogenic function of adipocytes. In vivo, a low dietary ω6:ω3 ratio improved the thermogenic response of brown and white adipose tissues to β3-adrenergic stimulation. This effect was recapitulated in vitro by PUFA treatment of hMADS adipocytes. We pinpointed the ω6-derived eicosanoid prostaglandin (PG)F2α as the molecular origin because the effects were mimicked with a specific PGF2α receptor agonist. PGF2α level in hMADS adipocytes was reduced in response to ω3 PUFA supplementation. The recruitment of thermogenic adipocytes is influenced by the local quantity of individual oxylipins, which is controlled by the ω6:ω3 ratio of available lipids. In human nutrition, energy homeostasis may thus benefit from the implementation of a more balanced dietary ω6:ω3 ratio.
Project description:Myopathies are chronic degenerative pathologies that induce the deterioration of the structure and function of skeletal muscle. So far a definitive therapy has not yet been developed and the main aim of myopathy treatment is to slow the progression of the disease. Current nonpharmacological therapies include rehabilitation, ventilator assistance, and nutritional supplements, all of which aim to delay the onset of the disease and relieve its symptoms. Besides an adequate diet, nutritional supplements could play an important role in the treatment of myopathic patients. Here we review the most recent in vitro and in vivo studies investigating the role supplementation with creatine, L-carnitine, and ω3 PUFAs plays in myopathy treatment. Our results suggest that these dietary supplements could have beneficial effects; nevertheless continued studies are required before they could be recommended as a routine treatment in muscle diseases.
Project description:The effect of marine-derived omega-3 polyunsaturated fatty acids (n-3 PUFA) on long-term outcome in renal transplant recipients (RTR) remains unclear. We investigated whether marine-derived n-3 PUFA intake is associated with all-cause and cardiovascular (CV) mortality in RTR. Intake of eicosapentaenoic acid plus docosahexaenoic acid (EPA-DHA) was assessed using a validated Food Frequency Questionnaire. Cox regression analyses were performed to evaluate the associations of EPA-DHA intake with all-cause and CV mortality. We included 627 RTR (age 53 ± 13 years). EPA-DHA intake was 102 (42-215) mg/day. During median follow-up of 5.4 years, 130 (21%) RTR died, with 52 (8.3%) due to CV causes. EPA-DHA intake was associated with lower risk of all-cause mortality (Hazard Ratio (HR) 0.85; 95% confidence interval (95% CI) 0.75-0.97). Age (p= 0.03) and smoking status (p = 0.01) significantly modified this association, with lower risk of all-cause and CV mortality particularly in older (HR 0.75, 95% CI 0.61-0.92; HR 0.68, 95% CI 0.48-0.95) and non-smoking RTR (HR 0.80, 95% CI 0.68-0.93; HR 0.74, 95% CI 0.56-0.98). In conclusion, marine-derived n-3 PUFA intake is inversely associated with risk of all-cause and CV mortality in RTR. The strongest associations were present in subgroups of patients, which adds further evidence to the plea for EPA-DHA supplementation, particularly in elderly and non-smoking RTR.
Project description:Omega-3 long chain polyunsaturated fatty acids (ω3 LC-PUFAs) such as eicosapentaenoic acid (EPA; 20:5ω3) and docosahexaenoic acid (DHA; 22:6ω3) are important fatty acids for human health. These ω3 LC-PUFAs are produced from their ω3 precursors by a set of desaturases and elongases involved in the biosynthesis pathway and are also converted from ω6 LC-PUFA by omega-3 desaturases (ω3Ds). Here, we have investigated eight ω3-desaturases obtained from a cyanobacterium, plants, fungi and a lower animal species for their activities and compared their specificities for various C18, C20 and C22 ω6 PUFA substrates by transiently expressing them in Nicotiana benthamiana leaves. Our results showed hitherto unreported activity of many of the ω3Ds on ω6 LC-PUFA substrates leading to their conversion to ω3 LC-PUFAs. This discovery could be important in the engineering of EPA and DHA in heterologous hosts.
Project description:Mycophenolic acid (MPA), an immunosuppressive drug widely used in kidney transplantation, has been suggested to have anti-fibrotic effects. To analyze at a genomic level these effects, we prospectively studied a group of stable kidney transplant recipients (n=35) on cyclosporine (CyA) and azathioprine treatment. Twenty patients were converted from azathioprine to MPA (MPA group) and 15 patients continued on azathioprine (AZA group). RNA was extracted by peripheral blood mononuclear cells at baseline and 3 months thereafter. Genomic analysis, performed on 5 randomly-selected MPA patients, revealed that 17 genes discriminated the transcriptomic profile after conversion. Neutral endopeptidase (NEP), an enzyme degrading angiotensin-II, was the most significant up-regulated gene. NEP expression level was inversely correlated to proteinuria at baseline and after conversion. Immunohistochemistry on graft biopsy of 33 independent patients demonstrated higher glomerular and tubular NEP protein expression in CyA+MPA (n=13) compared to CyA+AZA (n=12) and CyA alone (n=8). Glomerular NEP levels were inversely correlated to proteinuria and glomerulosclerosis. Tubular NEP expression was inversely correlated to interstitial fibrosis. Incubation of proximal tubular cells with MPA led to a dose- and time-dependent increase of NEP gene expression. The direct influence of MPA on NEP expression may suggest a novel therapeutic effect of this drug.
Project description:Mycophenolic acid (MPA), an immunosuppressive drug widely used in kidney transplantation, has been suggested to have anti-fibrotic effects. To analyze at a genomic level these effects, we prospectively studied a group of stable kidney transplant recipients (n=35) on cyclosporine (CyA) and azathioprine treatment. Twenty patients were converted from azathioprine to MPA (MPA group) and 15 patients continued on azathioprine (AZA group). RNA was extracted by peripheral blood mononuclear cells at baseline and 3 months thereafter. Genomic analysis, performed on 5 randomly-selected MPA patients, revealed that 17 genes discriminated the transcriptomic profile after conversion. Neutral endopeptidase (NEP), an enzyme degrading angiotensin-II, was the most significant up-regulated gene. NEP expression level was inversely correlated to proteinuria at baseline and after conversion. Immunohistochemistry on graft biopsy of 33 independent patients demonstrated higher glomerular and tubular NEP protein expression in CyA+MPA (n=13) compared to CyA+AZA (n=12) and CyA alone (n=8). Glomerular NEP levels were inversely correlated to proteinuria and glomerulosclerosis. Tubular NEP expression was inversely correlated to interstitial fibrosis. Incubation of proximal tubular cells with MPA led to a dose- and time-dependent increase of NEP gene expression. The direct influence of MPA on NEP expression may suggest a novel therapeutic effect of this drug. For microarray analysis, we studied 5 randomly selected patients included in the training group. Patients included in this group were, at the time of enrollment (T0), on standard maintenance immunosuppression with Cyclosporine (Neoral, Novartis, Basel, mean±SD of daily dose: 160.1±37.1mg), prednisone (5 mg daily) and Azathioprine (50 mg daily). Twenty patients, at T0, were switched from Azathioprine to EC-MPS (Myfortic, Novartis, Basel, 720 mg bid) for their need of allopurinol therapy (EC-MPS group). However, to avoid confounding factors, allopurinol treatment did not start until the end of our study (3 months). For the microarray analysis, we randomly selected 5 patients from the EC-MPS group. PBMC both at T0 and at T1 (3 months after the switching of the therapy) were immediately isolated from 20 ml of whole blood by Ficoll–Hypaque (Flow Laboratories, Irvine, UK) density gradient centrifugation. Total RNA was extracted by RNeasy mini kit (QIAGEN Inc., Valencia, CA) according the manufacturer’s instructions. Total RNA was processed and hybridized to the Affymetrix GeneChips Human Genome U133 Array Set HG-U133A (Affymetrix)(Affymetrix, Santa Clara, CA)
Project description:ObjectiveRegulation of angiogenesis is critical for many diseases. Specifically, pathological retinal neovascularization, a major cause of blindness, is suppressed with dietary ω3-long-chain polyunsaturated fatty acids (ω3LCPUFAs) through antiangiogenic metabolites of cyclooxygenase and lipoxygenase. Cytochrome P450 epoxygenases (CYP2C8) also metabolize LCPUFAs, producing bioactive epoxides, which are inactivated by soluble epoxide hydrolase (sEH) to transdihydrodiols. The effect of these enzymes and their metabolites on neovascularization is unknown.Approach and resultsThe mouse model of oxygen-induced retinopathy was used to investigate retinal neovascularization. We found that CYP2C (localized in wild-type monocytes/macrophages) is upregulated in oxygen-induced retinopathy, whereas sEH is suppressed, resulting in an increased retinal epoxide:diol ratio. With a ω3LCPUFA-enriched diet, retinal neovascularization increases in Tie2-driven human-CYP2C8-overexpressing mice (Tie2-CYP2C8-Tg), associated with increased plasma 19,20-epoxydocosapentaenoic acid and retinal epoxide:diol ratio. 19,20-Epoxydocosapentaenoic acids and the epoxide:diol ratio are decreased with overexpression of sEH (Tie2-sEH-Tg). Overexpression of CYP2C8 or sEH in mice does not change normal retinal vascular development compared with their wild-type littermate controls. The proangiogenic role in retina of CYP2C8 with both ω3LCPUFA and ω6LCPUFA and antiangiogenic role of sEH in ω3LCPUFA metabolism were corroborated in aortic ring assays.ConclusionsOur results suggest that CYP2C ω3LCPUFA metabolites promote retinal pathological angiogenesis. CYP2C8 is part of a novel lipid metabolic pathway influencing retinal neovascularization.