Effects of different intensities of strength and endurance training on some osteometabolic miRNAs, Runx2 and PPARγ in bone marrow of old male wistar rats

Abstract Bone tissue is known as a living dynamic and complex organ in response to physical activity and mechanical loading such as exercise training; thus, the purpose of this study was to determine the effect of different intensities of strength and endurance training on expression of some osteometabolic miRNAs and runt-related transcription factor 2 (Runx2) and peroxisome proliferator-activated receptor γ (PPARγ) in bone marrow of old male Wistar rats. To this end, a total number of 50 male Wistar rats (aged 23 months, 438.27 g) were obtained from Pasteur Institute of Iran. The rats were randomized into five groups (10 rats/per group) including moderate endurance training (MET), high-intensity endurance training (HET), moderateintensity resistance training (MRT), high-intensity resistance training (HRT), and control (CON). The four training groups completed 8 weeks of a training program, 5 days a week, according to the study protocol. To evaluate miR-133a, miR-103a, miR-204, and other adipogenic and osteogenic genes such as RUNX2 and PPARγ via real-time PCR, total RNA including mRNA and miRNA was isolated from the bone marrow. The statistical analysis was then performed using two-way analysis of variance (ANOVA). No significant differences in miR-133a (p = 0.197), miR-103a (p = 0.302), miR-204 (p = 0.539), RUNX2 (p = 0.960), and PPARγ (P = 0.872) were observed between the intervention groups and the control one. Furthermore, there were no significant differences in bone force (p = 0.641), fracture energy (p = 0.982), stress (p = 0.753), module (p = 0.147), and elongation (p = 0.292) variables between the intervention groups and the control group. Investigating molecular and cellular changes in the bone after such exercises in longer time could provide clearer results about the beneficial or harmful effects of these types of exercises in healthy and passive elderly people.

Bone Marrow · MiR-133a · Runx2 · Endurance and resistance training · PPARγ