Electrical pulse stimulation of primary human skeletal muscle cells

Electrical pulse stimulation (EPS) is an in vitro method of inducing contractions in cultured skeletal muscle cells of human and animal origin. Motor neuron activation of muscle fibres can be replaced by applying EPS on differentiated skeletal muscle cells (myotubes) in culture [1,2]. Here we describe two protocols for EPS of human myotubes in 6-well plates: acute, highfrequency (single bipolar pulses of 2 ms, 100 Hz for 200 ms every 5th sec for 5-60 min, 10-30 V) and chronic, low-frequency (single bipolar pulses of 2 ms, 1 Hz 10-30 V for 48 h) at the end of a 7 days long differentiation

Methods for proteomics-based analysis of the human muscle secretome using an in vitro exercise model.

Over the last decade, the skeletal muscle as a secretory organ has gained importance. A growing number of peptides is described which are produced and released by the muscle fibers and work in an autocrine, paracrine, and endocrine fashion. The contraction-induced secretion of these myokines is considered to contribute to the health promoting effects of exercise. To gain further insights into the molecular processes that occur during contraction, an in vitro exercise model, electric pulse stimulation (EPS), was established. Recent publications show that this model is suitable to electrostimulate human skeletal muscle cells and thus mimic muscle contraction in vitro. Here, we provide a detailed protocol for the proteomics-based analysis of the human muscle secretome, starting with the cultivation of human myotubes and ending with sample preparation for targeted and untargeted proteome analysis of the cell culture supernatant. This workflow should allow for deeper insights into the complex nature of the muscle secretome and the identification of new myokines which might help to understand the cross talk of the working muscle with different organs and the beneficial effects of exercise

Exercise benefits in cardiovascular disease : beyond attenuation of traditional risk factors

Despite strong scientific evidence supporting the benefits of regular exercise for the prevention and management of cardiovascular disease (CVD), physical inactivity is highly prevalent worldwide. In addition to merely changing well-known risk factors for systemic CVD, regular exercise can also improve cardiovascular health through non-traditional mechanisms. Understanding the pathways through which exercise influences different physiological systems is important and might yield new therapeutic strategies to target pathophysiological mechanisms in CVD. This Review includes a critical discussion of how regular exercise can have antiatherogenic effects in the vasculature, improve autonomic balance (thereby reducing the risk of malignant arrhythmias), and induce cardioprotection against ischaemia–reperfusion injury, independent of effects on traditional CVD risk factors. This Review also describes how exercise promotes a healthy anti-inflammatory milieu (largely through the release of muscle-derived myokines), stimulates myocardial regeneration, and ameliorates age-related loss of muscle mass and strength, a frequently overlooked non-traditional CVD risk factor. Finally, we discuss how the benefits of exercise might also occur via promotion of a healthy gut microbiota. We argue, therefore, that a holistic view of all body systems is necessary and useful when analysing the role of exercise in cardiovascular health