title: IL-6 and IGF-1 Signaling Within and Between Muscle and Bone: How Important is the mTOR Pathway for Bone Metabolism?
abstract: Insulin-like growth factor 1 (IGF-1) and interleukin 6 (IL-6) play an important role in the adaptation of both muscle and bone to mechanical stimuli. Here, we provide an overview of the functions of IL-6 and IGF-1 in bone and muscle metabolism, and the intracellular signaling pathways that are well known to mediate these functions. In particular, we discuss the Akt/mammalian target of rapamycin (mTOR) pathway which in skeletal muscle is known for its key role in regulating the rate of mRNA translation (protein synthesis). Since the role of the mTOR pathway in bone is explored to a much lesser extent, we discuss what is known about this pathway in bone and the potential role of this pathway in bone remodeling. We will also discuss the possible ways of influencing IGF-1 or IL-6 signaling by osteocytes and the clinical implications of pharmacological or nutritional modulation of the Akt/mTOR pathway.
authors.affiliation: Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands, a.bakker@acta.nl.
authors.forename: Astrid D
authors.initials: AD
authors.lastname: Bakker
authors.forename: Richard T
authors.initials: RT
authors.lastname: Jaspers
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000818:Animals; D001696:Biomechanical Phenomena / Q000502:physiology; D001842:Bone and Bones / Q000378:metabolism*; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000502:physiology*; D015850:Interleukin-6 / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D051057:Proto-Oncogene Proteins c-akt / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D013314:Stress, Mechanical; D058570:TOR Serine-Threonine Kinases / Q000502:physiology*
chemical_list: D015850:Interleukin-6; D007334:Insulin-Like Growth Factor I; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases