Muscle Wasting in Hemodialysis Patient

Muscle wasting is present in almost 50% of patients treated with chronic hemodialysis. It is associated with an increased risk of death (particularly from cardiovascular causes) and compromises quality of life (loss of autonomy and fatigue). The mechanisms leading to muscle wasting in chronic kidney disease have been the subject of several studies in animals. These have highlighted the role of the ubiquitin-proteasome system (UPS). Activation of UPS during chronic kidney disease is multifactorial. It is the result of resistance to the action of insulin/IGF1, metabolic acidosis, low grade prolonged inflammation and increased production of myostatin. To date few studies have been conducted in humans. The investigators want to identify blood markers related to muscle protein breakdown in patients undergoing hemodialysis. In parallel, the investigators want to adress the mechanisms involved in muscle proteolysis. In addition, the investigators want to identify the proteins degraded and the ubiquitination enzymes (E2/E3 couples) specifically involved in muscle loss during hemodialysis. Muscle biopsies and blood sample will beperformed during scheduled surgeries in healthy volunteers (negative control), cancer patients (positive control) or undergoing chronic hemodialysis. RNA seq analysis will be performed in blood samples and proteomic mass spectrometry analysis for establishing a specific profile between muscle and blood markers. A limited subset of blood markers common to cancer and hemodialysis atrophying muscles will be used for elaborating a chip dedicated to early detect an atrophying process. Thus, the investigators will first design a diagnostic tool for detecting non-invasively muscle protein breakdown before the onset of muscle atrophy. This will enable early and efficient nutritional counter-measures.