Research Seeds

PDF Possible Contribution of Dietary Functional Food Ingredients to Fatigue-Resistant Myofiber Generation

【Supercategory:7. DESCENTE SPORTS SCIENCE Subcategory:7.39 Vol.39

 ABSTRACT

 Proportions of muscle fiber types are responsible for a variety of properties of skeletal muscle, including contractile, metabolic, and sensory (differential tasting-component contents and fat deposition). Therefore mechanisms that regulate these properties, and their manipulation are hot targets of research for human sports and health sciences and animal production. We recently found that resident myogenic stem satellite cells secrete semaphoring 3A (Sema3A) protein which exclusively impacts the formation of fatigue-resistant fibers (also called slow-twitch fibers) through a cell-membrane receptor (neuropilin2-plexinA3 complex) → myogenin/MEF2D/HDAC7 → slow-myosin signaling pathway5). Here we report that an 8-week intake of chlorogenic-acid rich materials (APP; polyphenol mixture prepared from unriped apples) in the diet, may stimulate theSema3A-dependent pathway concerned. Results demonstrated improvement of lower hind-limb muscle endurance based on increased proportions of fatigue-resistant myofibers (types IIa and I) by the 0.5% APP-feeding to young-adult rats. There was no significant difference in the animal body-phenotypes or locomotor activity shown as total moving distance in light and dark periods. The result indicates that the shift in myosin heavy chain (MyHC) isoforms from fast-to-slow did not include a bias due to greater exercise behavior by the treated rats. Notably, a subsequent in vitro study showed that supplementation of APP (500 ng/ml) or the major component chlorogenic acid (10ng/ml) also up-regulated the expression of slow MyHC and the up-stream signaling molecules, myogenin and MEF2D, in primary cultures of differentiating myoblasts. Other major polyphenols found in APP (procyanidin B1, B2, phloridzin, and catechin) in a range of 10-1000ng/ml did not induce these effects. Therefore, the present study highlights a possible contribution of dietary chlorogenic acid intake to antagonizing the Sema3A-signaling pathway responsible for fatigue-resistant fiber formation. The finding may help in developing a novel strategy for application in human sports and age-related health sciences.

DESCENTE SPORTS SCIENCE Vol.39/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE
Researcher Ryuichi Tatsumi, Wataru Mizunoya
University or institution Department of Animal and Marine Biological Sciences, Graduate School of Agriculture, Kyushu University

Keywords

myogenic stem satellite cell, skeletal muscle, fatigue-resistant fiber, dietary polyphenol, Sema3A