title: Age related skeletal muscle atrophy and upregulation of autophagy in dogs.
abstract: Sarcopenia, the age related loss of muscle mass and strength, is a multifactorial condition that occurs in a variety of species and represents a major healthcare concern for older adults in human medicine. In veterinary medicine, skeletal muscle atrophy is often observed in dogs as they reach old age, but the process is not well understood. Autophagy is a mechanism for degradation and recycling of cellular constituents and is potentially involved in sarcopenia. The aim of the present study was to evaluate the expression of three markers of autophagy, Beclin 1, LC3 and p62, in muscle wasting of geriatric dogs, to establish whether the levels of autophagy change with increasing age. Muscle biopsies from 25 geriatric dogs were examined and compared with those from five healthy young dogs. Samples from older dogs, assessed by routine histology, histoenzymatic staining and immunohistochemistry, showed evidence of muscle atrophy, sarcoplasmic vacuolisation and mitochondrial alterations. Furthermore, in 80% of the muscle samples from the older dogs, marked intracytoplasmic staining for Beclin 1 and LC3 was observed. Significantly greater expression of LC3 II and Beclin 1, but lower expression of p62, was found by Western blotting, comparing muscle samples from old vs. young dogs. The results of the study suggest that enhanced autophagy might be one of the factors underlying muscle atrophy in dogs as they age.
authors.affiliation: Department of Veterinary Medicine and Animal Production, Laboratory of Comparative Neuromuscular Diseases, University of Naples Federico II, via Delpino 1, 80137 Napoli, Italy.
authors.forename: Teresa B
authors.initials: TB
authors.lastname: Pagano
authors.affiliation: Department of Anatomy and Neurobiology, Medical University of Gdansk, Debinki 1, 80-211 Gdansk, Poland.
authors.forename: Slawomir
authors.initials: S
authors.lastname: Wojcik
authors.affiliation: Department of Veterinary Medicine and Animal Production, Laboratory of Comparative Neuromuscular Diseases, University of Naples Federico II, via Delpino 1, 80137 Napoli, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Costagliola
authors.affiliation: Department of Veterinary Medicine and Animal Production, Laboratory of Comparative Neuromuscular Diseases, University of Naples Federico II, via Delpino 1, 80137 Napoli, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: De Biase
authors.affiliation: Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Iovino
authors.affiliation: Department of Veterinary Medicine and Animal Production, Laboratory of Comparative Neuromuscular Diseases, University of Naples Federico II, via Delpino 1, 80137 Napoli, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Iovane
authors.affiliation: Department of Veterinary Medicine and Animal Production, Laboratory of Comparative Neuromuscular Diseases, University of Naples Federico II, via Delpino 1, 80137 Napoli, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Russo
authors.affiliation: Department of Veterinary Medicine and Animal Production, Laboratory of Comparative Neuromuscular Diseases, University of Naples Federico II, via Delpino 1, 80137 Napoli, Italy.
authors.forename: Serenella
authors.initials: S
authors.lastname: Papparella
authors.affiliation: Department of Veterinary Medicine and Animal Production, Laboratory of Comparative Neuromuscular Diseases, University of Naples Federico II, via Delpino 1, 80137 Napoli, Italy. Electronic address: paciello@unina.it.
authors.forename: Orlando
authors.initials: O
authors.lastname: Paciello
mesh_terms: D000375:Aging; D000818:Animals; D001343:Autophagy / Q000502:physiology*; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D005260:Female; D008297:Male; D009133:Muscular Atrophy / Q000473:pathology / Q000662:veterinary*; D015854:Up-Regulation / Q000502:physiology*
keywords: Ageing; Autophagy; Canine; Muscle atrophy; Sarcopenia