title: Sarcopenia--The search for emerging biomarkers.
abstract: Sarcopenia, an age-related decline in skeletal muscle mass and function, dramatically affects the life quality of elder people. In view of increasing life expectancy, sarcopenia renders a heavy burden on the health care system. However, although there is a consensus that sarcopenia is a multifactorial syndrome, its etiology, underlying mechanisms, and even definition remain poorly delineated, thus, preventing development of a precise treatment strategy. The main aim of our review is to critically analyze potential sarcopenia biomarkers in light of the molecular mechanisms of their involvement in sarcopenia pathogenesis. Normal muscle mass and function maintenance are proposed to be dependent on the dynamic balance between the positive regulators of muscle growth such as bone morphogenetic proteins (BMPs), brain-derived neurotrophic factor (BDNF), follistatin (FST) and irisin, and negative regulators including TGFβ, myostatin, activins A and B, and growth and differentiation factor-15 (GDF-15). We hypothesize that the shift in this balance to muscle growth inhibitors, along with increased expression of the C- terminal agrin fragment (CAF) associated with age-dependent neuromuscular junction (NMJ) dysfunction, as well as skeletal muscle-specific troponin T (sTnT), a key component of contractile machinery, is a main mechanism underlying sarcopenia pathogenesis. Thus, this review proposes and emphasizes that these molecules are the emerging sarcopenia biomarkers.
authors.affiliation: Human Population Biology Research Unit, Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kalinkovich
authors.affiliation: Human Population Biology Research Unit, Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel. Electronic address: gregl@post.tau.ac.il.
authors.forename: Gregory
authors.initials: G
authors.lastname: Livshits
mesh_terms: D028341:Activins / Q000378:metabolism*; D000375:Aging / Q000502:physiology*; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism*; D055436:Growth Differentiation Factor 15 / Q000378:metabolism*; D006801:Humans; D055435:Myostatin / Q000378:metabolism*; D055948:Sarcopenia / Q000209:etiology / Q000378:metabolism
chemical_list: D015415:Biomarkers; D019208:Brain-Derived Neurotrophic Factor; D055436:Growth Differentiation Factor 15; D055435:Myostatin; D028341:Activins
keywords: Biomarker; Inflamm-aging; Muscle mass deterioration; Neuromuscular junction; Sarcopenia