Altered dynamics of lipid metabolism in muscle cells from patients with idiopathic inflammatory myopathy is ameliorated by 6 months of training

Abstract

Regular exercise improves muscle functional capacity and clinical state of patients with idiopathic inflammatory myopathy (IIM). r In our study, we used an in vitro model of human primary muscle cell cultures, derived from IIM patients before and after a 6-month intensive supervised training intervention to assess the impact of disease and exercise on lipid metabolism dynamics. r We provide evidence that muscle cells from IIM patients display altered dynamics of lipid metabolism and impaired adaptive response to saturated fatty acid load compared to healthy controls. r A 6-month intensive supervised exercise training intervention in patients with IIM mitigated disease effects in their cultured muscle cells, improving or normalizing their capacity to handle lipids. r These findings highlight the putative role of intrinsic metabolic defects of skeletal muscle in the pathogenesis of IIM and the positive impact of exercise, maintained in vitro by yet unknown epigenetic mechanisms.

The effect of a 24-week training focused on activities of daily living, muscle strengthening, and stability in idiopathic inflammatory myopathies: a monocentric controlled study with follow-up

“…However, our findings on stability, basal metabolism, and muscle fitness need to be interpreted with caution due to the borderline significant changes observed only after the first 12 weeks of our ADLRSp, probably due to an initiation effect, and thus deserve evaluation and confirmation in further studies. To conclude our observations, our recently published in vitro study on skeletal muscle cells [60], derived from the muscle biopsy samples of our IIM volunteers from the IG at baseline and after the 24week ADLRSp, might shed some light on the possible mechanism underlying the observed functional improvements in our study. Based on these in vitro data, our ADLRSp improved or normalized intrinsic metabolic defects represented by altered dynamics of lipid metabolism and impaired adaptive response to saturated fatty acid load [60].…”

“…To conclude our observations, our recently published in vitro study on skeletal muscle cells [60], derived from the muscle biopsy samples of our IIM volunteers from the IG at baseline and after the 24week ADLRSp, might shed some light on the possible mechanism underlying the observed functional improvements in our study. Based on these in vitro data, our ADLRSp improved or normalized intrinsic metabolic defects represented by altered dynamics of lipid metabolism and impaired adaptive response to saturated fatty acid load [60].…”

Epigenetic imprinting of human skeletal muscle cells: From metabolic diseases to myopathy

“…In this issue of The Journal of Physiology, Nemec et al (2021) (Bourlier et al 2013). Interestingly, chronic palmitate treatment for 3 days revealed training-induced molecular changes of lipid metabolism proteins such as mitochondrial respiratory complex proteins, 5 -AMP protein kinase and adipose triglyceride lipase.…”

“…In this issue of The Journal of Physiology , Nemec et al . (2021) show that 6 months’ supervised training improves muscle functional capacity and the clinical state of IIM patients. Training included 1 h per week of activities of daily living and 1 h of strength training with three series of 10–15 repetitions at 50–70% of 1 repetition maximum.…”

“…measured by elevated palmitate oxidation rate, in primary myotubes of IIM patients cultured before and at the end of the 6 months’ training programme (Nemec et al . 2021). This finding agrees with previous studies showing that training‐induced metabolic adaptations are retained in vitro in cultured human myotubes (Bourlier et al .…”