Proceedings of The Physiological Society

Europhysiology 2018 (London, UK) (2018) Proc Physiol Soc 41, C046

Oral Communications

Differing effects of younger and older human plasma on C2C12 myocytes in vitro

I. Kalampouka1, A. van Bekhoven2,1, B. T. Elliott1

1. University of Westminster, London, Please Select, United Kingdom. 2. Engineering & Applied Sciences, Hogeschool Rotterdam, Rotterdam, Netherlands.

  • Ex vivo plasma from older individuals reduces myocyte potential in vitro. A) Scratch injury recovery (% of baseline). B) representative scratch images. C) Myotubes diameter at 4, 24 and 48 hours post stimulation. C) correlation between plasma FLRG in vivo (pg.mL-1) and myotube diameter change (48 hours) in vitro.

Ageing is associated with a reduction of physiological function including muscle mass and strength. Endocrine factors such as myostatin, activin A, growth and differentiation factor 11 (GDF-11) and their inhibitory peptides influence muscle mass in health and disease. We hypothesised that myocytes cultured in plasma from older and younger individuals would show an ageing effect. Participants provided written, informed consent prior to participation. C2C12 myoblasts were stimulated with media conditioned with 5% plasma from healthy male participants (younger [n = 6, 18 - 35 years of age]; older [n = 6, > 57 years of age]). Plasma myostatin (total and free), follistatin-like binding protein (FLRG), GDF-11 and activin A were quantified by enzyme-linked immunosorbent assay, and all results are given as mean [SE]. FLRG and activin A were elevated in older individuals (FLG 4731.6 [522.5] vs 9915.8 [975.1] pg.mL-1; activin A 215.9 [20.2] vs 291.6 [21.0] pg.mL-1), whilst myostatin (free and total) and GDF-11 were not. Myoblasts in vitro showed no difference in proliferation rate between group, however scratch closure was greater in younger vs older plasma stimulated myoblasts (78.2 [2.2] % vs 87.2 [2.7] % of baseline scratch diameter, respectively). Myotube diameters were larger in cells stimulated with younger plasma than with older at 24 and 48 hours, but not at 4 hours. A significant negative correlation was noted between in vivo plasma FLRG concentration and in vitro myotube diameter 48 hours following plasma stimulation (r2 = 0.392, p = 0.030). Here we show that myoblasts and myotubes cultured in media conditioned with plasma from younger or older individuals show an ageing effect, and further this effect moderately correlates with circulating FLRG concentration in vivo. The effect of ageing on muscle function may not be innate to the tissue, but involve a general endocrine environment change. Further work is needed to examine the effect of increased FLRG concentration on muscle function in ageing populations.

Where applicable, experiments conform with Society ethical requirements