Time: Thursday, 19/June/2025: 11:40am - 12:30pm Session Chair: Dewi van Harskamp |
Location: 5161.0151 Bernoulliborg, Nijenborgh 9, 9747 AG Groningen |
Keynote: Post-prandial protein handling: You are what you just ate.
Maastricht University, Netherlands, The
Skeletal muscle protein is constantly being synthesized and broken down, with a turnover rate of about 1-2% per day. The rate of skeletal muscle protein synthesis is regulated by two main metabolic stimuli, food intake and physical activity. Food intake, or more specifically protein ingestion, directly elevates muscle protein synthesis rates. The dietary protein derived essential amino acids act as signaling molecules activating anabolic pathways and provide precursors for muscle protein synthesis. Ingestion of a meal-like amount of dietary protein elevates muscle protein synthesis rates for several hours, providing evidence that ‘you are what you just ate’. When food is ingested after a bout of physical activity the post-prandial muscle protein synthetic response is augmented, with higher muscle protein synthesis rates sustained over a more prolonged period of time. In other words, when you ingest protein following a bout of physical activity ‘you become even more of what you just ate’. In contrast, when protein is ingested following a period of inactivity the post-prandial muscle protein synthetic response is blunted, coined anabolic resistance. Therefore, disuse makes you ‘become less of what you just ate’. These concepts play a key role in the prevention and management of muscle loss in both health and disease.
Development of a GC-C-IRMS Method for Quantitative and Isotopic Analysis of Fatty Acids in Breast Cancer Patient Samples
1Université Claude Bernard Lyon 1, CNRS, ISA, UMR 5280, 5 rue de la Doua, F-69100 Villeurbanne, France; 2CEISAM UMR CNRS 6230, Nantes Université, Nantes, France; 3Nutrition, croissance et cancer UMR 1069, Inserm, Université de Tours, France
The discovery of biomarkers is essential for the development of novel methods for early diagnosis, prognosis, and therapeutic strategies. Building on our patented results, isotopomic analysis—a technique that determines high-throughput isotopic profiles or signatures from global, intra-, or inter-molecular measurements in natural or enriched abundance—shows great promise for identifying new biomarkers.
This study aims to develop a novel method for the quantitative and ¹³C isotopic analysis of fatty acids in biological samples from breast cancer patients, using gas chromatography coupled with isotope ratio mass spectrometry (GC-C-IRMS). Unlike conventional methods, the proposed approach eliminates the derivatization of fatty acids into methyl esters, reducing the consumption of polluting solvents and avoiding the introduction of exogenous carbon, which could alter ¹³C values. Lipids are extracted from biological samples, such as serum or adjacent/tumor tissues, followed by saponification to obtain free fatty acids, which are then analyzed by GC-C-IRMS.
This method simultaneously quantifies fatty acids in the biological matrix and determines their ¹³C isotopic compositions (δ¹³C). Fatty acids, including myristic acid (C14:0), palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), palmitoleic acid (C16:1), and linoleic acid (C18:2), were identified, quantified, and characterized isotopically across various biological matrices. Analytical validation parameters demonstrated the specificity, linearity, precision, accuracy, and robustness of the method in standard mixtures and biological samples.
The method was applied to adjacent, cancerous tissues and serum from breast cancer patients. Several breast cancer families were compared (HER2-, HER2+, triple positive, triple negative and in situ) and revealed differences in the concentration and isotopic composition of the analyzed fatty acids.
The GC-C-IRMS analytical method provides a reliable and efficient approach for identifying specific biomarkers, offering potential diagnostic, prognostic, and therapeutic applications in breast cancer management.