Research Activities

The objective is to study the effects of diet on protein-energy metabolism and the functional capacities (contractile and metabolic) of skeletal muscle during aging. In addition to dietary protein intake, a central regulator of this metabolism, I am interested in the matrix environment, that is, the potentially permissive or inhibiting effects of nutrients accompanying dietary proteins. Indeed, until very recently, scientists considered that protein anabolism in the postprandial phase was regulated primarily by amino acids. New clinical and preclinical studies have nevertheless shown that, in addition to protein intake, other nutrients participate specifically, or in concert with amino acids, in the positive (vitamin D, oleate, omega-3 polyunsaturated fatty acids) or negative (palmitate) regulation of muscle protein anabolism. It should be noted that aging seems to be accompanied by a deregulation of muscle adaptation capacities to these signal nutrients, partly explaining the development of sarcopenia in the elderly. My current and future work therefore focuses on the quality of dietary proteins coupled with the action of nutrients regulating protein anabolism. They focus on food matrices favorable to muscle protein anabolism. In this context, even if the interest of animal products is recognized, a new place must be defined for products of plant origin considering their nutritional characteristics and their sustainability. Consequently, the interest of certain plant products rich in protein (legumes, cereals) and different processing methods (inclusion in pasta, in dairy products, etc.) on the maintenance of muscle mass and functions during aging is currently being evaluated.

Most notable publications

• Walrand S, Gryson C, Salles J, Giraudet C, Migné C, Bonhomme C, Le Ruyet P, Boirie Y. Fast-digestive protein supplement for ten days overcomes muscle anabolic resistance in healthy elderly men. Clin Nutr. 2015 May 8. In press.
• Gryson C, Ratel S, Rance M, Penando S, Bonhomme C, Le Ruyet P, Duclos M, Boirie Y, Walrand S. Four-month course of soluble milk proteins interacts with exercise to improve muscle strength and delay fatigue in elderly subjects. J Am Med Dir Assoc. 2014 Dec;15(12):958.e1-9.
• Tardif N, Salles J, Guillet C, Tordjman J, Reggio S, Landrier JF, Giraudet C, Patrac V, Bertrand-Michel J, Migne C, Collin ML, Chardigny JM, Boirie Y, Walrand S. Muscle ectopic fat deposition contributes to anabolic resistance in obese sarcopenic old rats through eIF2α activation. Aging Cell. 2014 Dec;13(6):1001-11.
• Walrand S, Short KR, Heemstra LA, Novak CM, Levine JA, Coenen-Schimke JM, Nair KS. Altered regulation of energy homeostasis in older rats in response to thyroid hormone administration. FASEB J. 2014 Mar;28(3):1499-510.
• Salles J, Chanet A, Giraudet C, Patrac V, Pierre P, Jourdan M, Luiking YC, Verlaan S, Migné C, Boirie Y, Walrand S. 1,25(OH)2-vitamin D3 enhances the stimulating effect of leucine and insulin on protein synthesis rate through Akt/PKB and mTOR mediated pathways in murine C2C12 skeletal myotubes. Mol Nutr Food Res. 2013 Dec;57(12):2137-46.
• Salles J, Tardif N, Landrier JF, Mothe-Satney I, Guillet C, Boue-Vaysse C, Combaret L, Giraudet C, Patrac V, Bertrand-Michel J, Denis P, Chardigny JM, Boirie Y, Walrand S. TNFα gene knockout differentially affects lipid deposition in liver and skeletal muscle of high-fat-diet mice. J Nutr Biochem. 2012 Dec;23(12):1685-93.

Other links

• https://www.linkedin.com/in/stephane-walrand-8b1b1936/
• ASMS