Paju 2014 Abstract MiP2014
|Characterization of the effects of pro-inflammatory cytokines on energy metabolism in human myoblasts.
Ageing is frequently associated with sarcopenia, which has been attributed to low grade inflammation, suppressed regenerative potential of muscle precursor cells and homeostatic changes in the niches of satellite cells of old persons [1,2]. The aim of this study was to investigate mitochondrial function in primary cell cultures, derived from biopsies taken from young and old individuals.
Primary muscle cell culture myoblasts, obtained from biopsies of vastus lateralis in young (19-29 y) and old (70-80 y) subjects, were purified with CD56 antibody microbeads on MACS and cultured in the presence of HGF. The cultures were stimulated with differentiation media supplement, insulin-transferrin-sodium selenite (ITS), for 6 days with one of cytokines IL1, IL6 or TNF-α. The function of respiratory complexes (OXPHOS) was assessed by high-resolution respirometry.
The myoblasts cultivated from old individuals differentiated into myotubes markedly slower than myoblasts from young individuals in ITS medium (P<0.0001). The effect of IL-6 depended on donor age, as its effect on myoblast differentiation decreased with age. Treatment of human myoblasts with TNF-α and IL-1β increased the proliferation and blocked differentiation in the presence of ITS. The inhibitory effect of TNF-α and IL-1β on myotubes formation was mediated by down-regulation of mRNA levels of myogenin and muscle-specific isoforms of CK (CKM and CKMT2). The data on mitochondrial respiration revealed that IL-1β caused a significant decrease in mitochondrial Complex I- and II-linked respiration, normalized on cell protein content both in the myotubes of old and young individuals. This action of IL1-β was not seen when the respiratory results were normalized on citrate synthase activity, revealing the role of a decrease in mitochondrial content in these cells. TNF-α, on the contrary, caused a significant increase in mitochondrial Complex I- and II-linked respiration, normalized on protein in myotubes of old and young subjects. This action of TNF-α remained significant when respiration was normalized on citrate synthase activity. The mode of action of these pro-inflammatory cytokines on OXPHOS of muscle cell cultures was the same in both groups, young and old persons.
Our data suggest that the myoblasts cultivated from biopsies of old individuals differentiate into myotubes slower than those from young individuals. The actions of pro-inflammatory cytokines on OXPHOS level of these cell cultures are different: IL-1β decreased, TNF-α stimulated but IL-6 exerted no alteration on OXPHOS activity, both in old or young individuals. The OXPHOS capacity in myogenic cell culture depends more on the mode of action of cytokine than the donor’s age.
• O2k-Network Lab: EE Tartu Paju K
Labels: MiParea: Respiration, Patients Pathology: Aging;senescence
Organism: Human Tissue;cell: Skeletal muscle Preparation: Permeabilized cells
Coupling state: OXPHOS Pathway: N, S HRR: Oxygraph-2k Event: C1, Oral MiP2014
Dep Pathophysiol, Inst Biomedicine Translational Medicine, Univ Tartu, Estonia. - [email protected]
References and acknowledgements
Supported by: EU-MYOAGE project FP7 223576 and by grants of Estonian Science Foundation No 7823 and 8736.
- Cevenini E, Monti D, Franceschi C (2013) Inflamm-ageing. Curr Opin Clin Nutr Metab Care 16:14-20.
- Beccafico S, Puglielli C, Pietrangelo T, Bellomo R, Fano G, Fulle S (2007) Age-dependent effects on functional aspects in human satellite cells. Ann NY Acad Sci 1100:345-52.