title: Angiotensin II: role in skeletal muscle atrophy.
abstract: Skeletal muscle, the main protein reservoir in the body, is a tissue that exhibits high plasticity when exposed to changes. Muscle proteins can be mobilized into free amino acids when skeletal muscle wasting occurs, a process called skeletal muscle atrophy. This wasting is an important systemic or local manifestation under disuse conditions (e.g., bed rest or immobilization), in starvation, in older adults, and in several diseases. The molecular mechanisms involved in muscle wasting imply the activation of specific signaling pathways which ultimately manage muscle responses to modulate biological events such as increases in protein catabolism, oxidative stress, and cell death by apoptosis. Many factors have been involved in the generation and maintenance of atrophy in skeletal muscle, among them angiotensin II (Ang-II), the main peptide of renin-angiotensin system (RAS). Together with Ang-II, the angiotensin-converting enzyme (ACE) and the Ang-II receptor type 1 (AT-1 receptor) are expressed in skeletal muscle, forming an important local axis that can regulate its function. In many of the conditions that lead to muscle wasting, there is an impairment of RAS in a global or local fashion. At this point, there are several pieces of evidence that suggest the participation of Ang-II, ACE, and AT-1 receptor in the generation of skeletal muscle atrophy. Interestingly, the Ang-II participation in muscle atrophy is strongly ligated to the regulation of hypertrophic activity of factors such as insulin-like growth factor 1 (IGF-1). In this article, we reviewed the current state of Ang-II and RAS function on skeletal muscle wasting and its possible use as a therapeutic target to improve skeletal muscle function under atrophic conditions.
authors.affiliation: Laboratorio de Biología y Fisiopatología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas & Facultad de Medicina, Universidad Andres Bello, Santiago, Chile. Av. Republica 239, Postal Code 8370146, Santiago, Chile. claudio.cabello@unab.cl
authors.forename: Claudio
authors.initials: C
authors.lastname: Cabello-Verrugio
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Córdova
authors.forename: José Diego
authors.initials: JD
authors.lastname: Salas
mesh_terms: D000804:Angiotensin II / Q000378:metabolism*; D000818:Animals; D006801:Humans; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism*; D009133:Muscular Atrophy / Q000378:metabolism* / Q000473:pathology / Q000517:prevention & control; D011945:Receptors, Angiotensin / Q000378:metabolism; D012084:Renin-Angiotensin System / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D011945:Receptors, Angiotensin; D000804:Angiotensin II