Proteasome activities in the rectus abdominis muscle of young and older individuals
- 11 March 2008
- journal article
- research article
- Published by Springer Science and Business Media LLC in Biogerontology
- Vol. 9 (4), 261-268
- https://doi.org/10.1007/s10522-008-9135-9
Abstract
Sarcopenia is one of the most striking effects of age, the causes and the pathogenic mechanisms being largely unknown. Unfortunately, there is limited information on the effect of aging on muscle protein breakdown in basal conditions. The present study aimed at investigating if skeletal muscle ubiquitn mRNA levels and proteasome activities vary with age in healthy individuals. Ub mRNA levels were measured by northern blot analysis whereas proteasome activities were determined by evaluating the cleavage of specific fluorogenic substrates in the rectus abdominis muscle of 14 healthy male individuals. Patients were divided in three groups according to the age: (1) 20–30 years (N = 3); (2) 31–64 years (N = 5); (3) ≥65 years (N = 6). Quantitation of the ubiquitin mRNA levels (expressed in arbitrary units) (mean (SD) showed no differences among the three groups of age (20–30 years: 1352 ± 441; 31–64 years: 1324 ± 439; ≥65 years: 884 ± 400; P = 0.33). The correlation between age and muscle ubiquitin mRNA levels was not statistically significant (r = −0.4, P = 0.26). The three proteasome activities, chymotrypsin-like (CTL), trypsin-like (TL) and peptidyl-gutamyl-peptidase (PGP), expressed as nkatal × 10−3/mg protein, were similar in the three groups of patients stratified according to the age. There was no correlation between age with either CTL (r = 0.22, P = 0.4), PGP (r = 0.002, P = 0.9), and TL (r = 0.28, P = 0.33) activities. In conclusion, the present study shows that the skeletal muscle proteasome activities do not differ with age in healthy male individuals.Keywords
This publication has 27 references indexed in Scilit:
- Atrophy-related ubiquitin ligases, atrogin-1 and MuRF1 are up-regulated in aged rat Tibialis Anterior muscleMechanisms of Ageing and Development, 2006
- Atrogin-1/MAFbx and MuRF1 Are Downregulated in Aging-Related Loss of Skeletal MuscleThe Journals of Gerontology: Series A, 2006
- Selective downregulation of ubiquitin conjugation cascade mRNA occurs in the senescent rat soleus muscleExperimental Gerontology, 2005
- Ubiquitin expression is up-regulated in human and rat skeletal muscles during agingArchives of Biochemistry and Biophysics, 2004
- Mechanisms of skeletal muscle depletion in wasting syndromes: role of ATP-ubiquitin-dependent proteolysisCurrent Opinion in Clinical Nutrition and Metabolic Care, 2003
- The relationship between skeletal muscle proteolysis and ubiquitin–proteasome proteolytic pathway in burned ratsBurns, 2002
- Increased muscle ubiquitin mRNA levels in gastric cancer patientsAmerican Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 2001
- Activation of Ca2+-dependent proteolysis in skeletal muscle and heart in cancer cachexiaBritish Journal of Cancer, 2001
- Changes in 20S proteasome activity during ageing of the LOU ratMolecular Biology Reports, 1999
- Isolated bovine retinal pigment epithelial cells express delayed rectifier type and M-type K+ currents.American Journal of Physiology-Cell Physiology, 1997