The Impact of Physical Exercise on microRNAs in Hemodialysis Patients.

ABSTRACT Physical inactivity is considered a significant risk factor for mortality and morbidity in chronic hemodialysis (HD) patients. Therefore, physical exercise (PE) is recommended for treating HD patients. Although the beneficial effects of physical activity in HD patients are well described in the literature, the underlying physiological mechanisms are not yet fully known. Recently, microRNAs (miRNAs) have emerged as potential mediators of the therapeutic effects of PE in healthy individuals. MiRNAs are short, single-stranded, non coding RNAs involved in regulating gene expression. Specifically, miRNAs selectively bind to specific mRNAs within cells by forming the RNA-induced silencing complex (RISC), reducing gene expression. MiRNAs can be secreted from cells in free form or enclosed within exosomes or extracellular vesicles. They can be detected in various body fluids, including serum (circulating miRNAs), facilitating the study of their diverse expression. Currently, no data are available on the impact of PE on the expression of miRNAs involved in osteogenic differentiation, a key mechanism in the development of vascular calcification, in HD patients. Therefore, we designed a longitudinal observational case-control study to evaluate primarily the expression of circulating miRNAs, such as miR-9 and miR-30b and secondarily, the expression of molecules modulated by miRNAs, like Sirt1, p21 and p53, on Mesenchymal Osteogenic cells and HEK293 cells in HD patients participating in a 3-month extra-dialytic exercise program.