Osteoporosis is highly prevalent in postmenopausal women, causing chronic pain, fractures, and limited mobility that burden individuals and society. While resistance exercise benefits bone health, its role in osteoporotic bone injury healing and underlying mechanisms remain unclear. This study aimed to explore the effects of 10-week weight-bearing ladder climbing exercise on ovariectomy (OVX)-induced osteoporosis and subsequent bone injury healing, and to investigate whether these effects are associated with the myostatin (MSTN) and Wnt/β-catenin pathways. Fifty-four 12-week-old female SD rats were randomized into Sham, OVX, and OVX + EX groups. Rats in the OVX and OVX + EX groups underwent ovariectomy to induce postmenopausal osteoporosis, and those in the OVX + EX group received 10-week weight-bearing ladder climbing. After the exercise intervention, 6 rats in each group were sacrificed; the remaining rats underwent femoral midshaft drilling to establish bone injury. The improvement in osteoporosis was evaluated via Micro-CT, biomechanical tests, RT-qPCR for mRNA detection, and Western blot for measuring protein levels of MSTN and Wnt/β-catenin pathway-related molecules at post-exercise and 21 days post-injury. Bone healing was reflected by the bone volume fraction at the bone injury site detected via Micro-CT at 10 and 21 days post-injury. This exercise significantly enhanced muscle strength and improved femoral bone mineral density (BMD), trabecular microstructure, and biomechanical properties in OVX rats. Meanwhile, the level of MSTN in the OVX + EX group was decreased, the expression of its downstream signaling pathways was inhibited, and the mRNA and protein expressions of Wnt/β-catenin were upregulated. Moreover, 21 days after exercise intervention, the biomechanical properties and bone microstructure of the OVX + EX group were still significantly superior to those of the OVX group, and the aforementioned molecular regulatory effect remained. In addition, pre-conducted exercise was able to promote increases in bone volume fraction at the bone injury site 10 and 21 days after drilling, which was conducive to bone injury healing. Ten-week weight-bearing ladder climbing ameliorates OVX-induced bone loss and promotes osteoporotic bone repair via regulating the MSTN/ActRIIB/Smad3 and Wnt/β-catenin pathways, providing evidence for exercise as a safe non-pharmacological intervention.

Objective: Insulin resistance (IR) is a complex and multifactorial disorder that contributes to type 2 diabetes and cardiovascular disease. MicroRNAs (miRNAs) play important roles in diverse developmental and disease processes. However, the molecular mechanisms of IR are unclear. This paper aims to explore the role of miRNA in regulating IR and to elucidate the mechanisms responsible for these effects. Methods: IR models were created by feeding a high-fat diet (HFD) to mice or stimulating 3T3-L1 cells with palmitate. Twelve weeks of HFD trigger weight gain, leading to lipid accumulation and insulin resistance in mice. The expression profiles of miRNAs in adipose tissues (AT) from the HFD-induced mouse models were analyzed. The relationship between miR-221-3p and SOCS1 was determined using dual luciferase reporter gene assays. Metabolic alterations in AT were investigated by real-time PCR and Western blot. Results: miR-221-3p was significantly increased in AT. HFD-induced disturbances in glucose homeostasis were aggravated by miR-221-3p upregulation. The inhibition of miR-221-3p promoted insulin sensitivity including reduced lipid accumulation and the disruption of glucose metabolism. Of note, the 3′-UTR of SOCS1 was found to be a direct target of miR-221-3p. The SOCS1 inhibitor attenuated miR-221-3p-induced increases in IRS-1 phosphorylation, AKT phosphorylation, and GLUT4. miR-221-3p was considered to be involved in the PI3K/AKT signaling pathway, thus leading to increased insulin sensitivity and decreased IR in HFD-fed mice and 3T3-L1 adipocytes. Conclusions: The miR-221-3p/SOCS1 axis in AT plays a pivotal role in the regulation of glucose metabolism, providing a novel target for treating IR and diabetes.

Background: Motor observation (MO) and concurrent observation and physical practice (MP) are two commonly used approaches during early motor skill acquisition. This study tests an integrated Action Observation Training-Neuroplasticity Theory (AOT-NPT) framework, hypothesizing that: (H1) MP will elicit stronger functional connectivity in frontoparietal networks compared to MO; (H2): transitioning from an easier to a more demanding motor task will be associated with changes in functional connectivity patterns, particularly in the MP condition; (H3): functional connectivity will demonstrate method-dependent relationships with behavioral performance, with MP expected to show stronger positive brain–behavior associations. Methods: A two-factor mixed design was employed. The between-subjects factor was learning methods (MO, MP), and the within-subjects factor was task difficulty (Easy, Medium). Mobile EEG recorded neural activity during 24-Style Tai Chi learning (MO vs. MP; easy vs. medium). Source-level connectivity analysis and video-based motor performance scoring were applied. Findings: Both EEG and behavioral data provided evidence that MP surpasses MO, as indicated by stronger source functional connectivity, better motor performance, and changes in functional connectivity during the transition from an easier to a more demanding task. Additionally, functional connectivity in MP was significantly positively correlated with motor performance. Contribution: The present findings support the neurobehavioral advantage of integrating physical practice into action observation during early closed motor skill learning. This validates the AOT-NPT framework and establishes a concurrent observation and physical practice model for closed motor skill pedagogy.

Studies show that athletes have better trust behaviors than ordinary college students, likely due to their long-term sports training. However, the impact of sports training may vary with the team-based nature of the sports. It's still unclear whether there are differences in interpersonal trust behaviors and neural mechanisms among athletes from different types of teams. This study compared the differences in these aspects between athletes from cooperative-competitive teams and those from competitive-cooperative teams. Our study recruited 48 athletes dyads. 24 dyads were from team sports (e.g., basketball, soccer) and were grouped into the cooperative-competitive group (cooperation group), since their training involved more cooperation than competition, including 12 male and 12 female dyads. The other 24 dyads, from individual sports (e.g., athletics, tennis), formed the competitive-cooperative group (competitive group), as their training was more competitive than cooperative, and also included 12 male and 12 female dyads. A two-factor experimental design was used. During trust-game tasks, interpersonal trust behaviors and prefrontal interpersonal neural synchronization (INS) changes were monitored in real time via functional Near-infrared Spectroscopy (fNIRS) hyperscanning. Behaviorally, the cooperation group showed more investment behaviors in trust games than the competition group. In brain data, during investment decisions, female athletes in the cooperation group had stronger left frontal lobe INS than those in the competition group. Also, in the competition group, female athletes showed stronger left dorsolateral prefrontal INS during investment decisions than male athletes. The study indicates that team type and sex significantly affect athletes' interpersonal trust behaviors, along with specific brain area INS changes. It offers a new angle for research on sports training and trust behavior, filling a gap in the field.