Warburg effect characterizes the skeletal muscle in Fabry Disease: experimental evidence and clinical implications

<p>Skeletal muscle (SM) pain and fatigue are common in Fabry disease (FD), and strongly impact the patient&rsquo;s quality of life. Still, the SM in FD is poorly investigated. Although energetic alterations are reported in cells from FD patients, they have never been related to fatigue and pain. Given the pivotal relevance of energetics for SM health, we undertook the investigation of the SM. We consistently observed a reduced tolerance to aerobic activity and lactate accumulation in FD-humanized mouse model and patients. Accordingly, in sedentary mouse FD SM we detected an increase in fast/glycolytic-fibers, mirrored by an upregulation of glycolytic enzymes and glucose-transporters. In fibroblasts derived from FD patients, we confirmed a high glycolytic-rate and accordingly, metabolomic/lipidomic-analysis revealed that lipids are underutilized as energetic fuel in FD-patients. In the quest for a tentative mechanism, we explored analogies with genetic myopathies, that show altered expression of energetic metabolism. Specifically, we explored HIF-1 upregulation and found it increased in FD mice and patients. From a screening of miRNAs associated with metabolic stress, we found the significant upregulation of miR-17, which has been previously associated with HIF-1 up-regulation. A specific antagomir targeting miR-17 was able to inhibit HIF-1 accumulation and revert metabolic-remodeling in FD-cells. Our findings unveil an anaerobic glycolytic-switch under normoxia, known as Warburg Effect, which is induced by miR-17-mediated-upregulation of HIF-1. The miR-17/HIF-1 pathway can be a new therapeutic target in FD, and Exercise-testing and blood lactate may become a new diagnostic and monitoring-tool in FD.</p>