The interdependent relationship between the nitric oxide signaling pathway and primary cilia in pulse electromagnetic field-stimulated osteoblastic differentiation

Clavicle fracture and triathlon performance: a case report

BACKGROUND

Collarbone fracture is a common injury, particularly among athletes involved in contact sports and participating in endurance activities. Conventional treatment requires surgery and postoperative immobilization, resulting in an average return-to-sport timeframe of approximately 13 weeks. This case challenges the established treatment protocols, aiming to expedite recovery and enable a quicker resumption of high-intensity athletic activities.

CASE PRESENTATION

A 24-year-old Caucasian athlete completed a Half-Ironman Triathlon (70.3) merely three weeks post-collarbone fracture. Utilizing Extracorporeal Magneto-Transduction Therapy (EMTT) alongside surgical intervention, the patient achieved accelerated healing and remarkable performance outcomes without encountering any adverse effects.

CONCLUSIONS

The integration of EMTT into the treatment paradigm for bone fractures alters the traditional understanding of recovery timelines and rehabilitation strategies. This case highlights the potential benefits of electromagnetic wave therapy in expediting the healing process and enabling athletes to resume high-level sports activities at an earlier stage.

Pulsed Electromagnetic Fields Induce Skeletal Muscle Cell Repair by Sustaining the Expression of Proteins Involved in the Response to Cellular Damage and Oxidative Stress

Pulsed electromagnetic fields (PEMF) are employed as a non-invasive medicinal therapy, especially in the orthopedic field to stimulate bone regeneration. However, the effect of PEMF on skeletal muscle cells (SkMC) has been understudied. Here, we studied the potentiality of 1.5 mT PEMF to stimulate early regeneration of human SkMC. We showed that human SkMC stimulated with 1.5 mT PEMF for four hours repeated for two days can stimulate cell proliferation without inducing cell apoptosis or significant impairment of the metabolic activity. Interestingly, when we simulated physical damage of the muscle tissue by a scratch, we found that the same PEMF treatment can speed up the regenerative process, inducing a more complete cell migration to close the scratch and wound healing. Moreover, we investigated the molecular pattern induced by PEMF among 26 stress-related cell proteins. We found that the expression of 10 proteins increased after two consecutive days of PEMF stimulation for 4 h, and most of them were involved in response processes to oxidative stress. Among these proteins, we found that heat shock protein 70 (HSP70), which can promote muscle recovery, inhibits apoptosis and decreases inflammation in skeletal muscle, together with thioredoxin, paraoxonase, and superoxide dismutase (SOD2), which can also promote skeletal muscle regeneration following injury. Altogether, these data support the possibility of using PEMF to increase SkMC regeneration and, for the first time, suggest a possible molecular mechanism, which consists of sustaining the expression of antioxidant enzymes to control the important inflammatory and oxidative process occurring following muscle damage.

Simulated microgravity-induced oxidative stress and loss of osteogenic potential of osteoblasts can be prevented by protection of primary cilia

Oxidative stress has been considered to be closely related to spaceflight-induced bone loss; however, mechanism is elusive and there are no effective countermeasures. Using cultured rat calvarial osteoblasts exposed to microgravity simulated by a random positioning machine, this study addressed the hypotheses that microgravity-induced shortening of primary cilia leads to oxidative stress and that primary cilium protection prevents oxidative stress and osteogenesis loss. Microgravity was found to induce oxidative stress (as represented by increased levels of reactive oxygen species (ROS) and malondialdehyde production, and decreased activities of antioxidant enzymes), which was perfectly replicated in osteoblasts growing in NG with abrogated primary cilia (created by transfection of an interfering RNA), suggesting the possibility that shortening of primary cilia leads to oxidative stress. Oxidative stress was accompanied by mitochondrial dysfunction (represented by increased mitochondrial ROS and decreased mitochondrial membrane potential) and intracellular Ca2+ overload, and the latter was found to be caused by increased activity of Ca2+ channel transient receptor potential vanilloid 4 (TRPV4), as also evidenced by TRPV4 agonist GSK1016790A-elicited Ca2+ influx. Supplementation of HC-067047, a specific antagonist of TRPV4, attenuated microgravity-induced mitochondrial dysfunction, oxidative stress, and osteogenesis loss. Although TRPV4 was found localized in primary cilia and expressed at low levels in NG, microgravity-induced shortening of primary cilia led to increased TRPV4 levels and Ca2+ influx. When primary cilia were protected by miR-129-3p overexpression or supplementation with a natural flavonoid moslosooflavone, microgravity-induced increased TRPV4 expression, mitochondrial dysfunction, oxidative stress, and osteogenesis loss were all prevented. Our data revealed a new mechanism that primary cilia function as a controller for TRPV4 expression. Microgravity-induced injury on primary cilia leads to increased expression and overactive channel of TRPV4, causing intracellular Ca2+ overload and oxidative stress, and primary cilium protection could be an effective countermeasure against microgravity-induced oxidative stress and loss of osteogenic potential of osteoblasts.

Recent advances in primary cilia in bone metabolism

Primary cilia are microtubule-based organelles that are widespread on the cell surface and play a key role in tissue development and homeostasis by sensing and transducing various signaling pathways. The process of intraflagellar transport (IFT), which is propelled by kinesin and dynein motors, plays a crucial role in the formation and functionality of cilia. Abnormalities in the cilia or ciliary transport system often cause a range of clinical conditions collectively known as ciliopathies, which include polydactyly, short ribs, scoliosis, thoracic stenosis and many abnormalities in the bones and cartilage. In this review, we summarize recent findings on the role of primary cilia and ciliary transport systems in bone development, we describe the role of cilia in bone formation, cartilage development and bone resorption, and we summarize advances in the study of primary cilia in fracture healing. In addition, the recent discovery of crosstalk between integrins and primary cilia provides new insights into how primary cilia affect bone.

The Possible Role of Electrical Stimulation in Osteoporosis: A Narrative Review

Osteoporosis is mainly a geriatric disease with a high incidence, and the resulting spinal fractures and hip fractures cause great harm to patients. Anti-osteoporosis drugs are the main treatment for osteoporosis currently, but these drugs have potential clinical limitations and side effects, so the development of new therapies is of great significance to patients with osteoporosis. Electrical stimulation therapy mainly includes pulsed electromagnetic fields (PEMF), direct current (DC), and capacitive coupling (CC). Meanwhile, electrical stimulation therapy is clinically convenient without side effects. In recent years, many researchers have explored the use of electrical stimulation therapy for osteoporosis. Based on this, the role of electrical stimulation therapy in osteoporosis was summarized. In the future, electrical stimulation might become a new treatment for osteoporosis.