Professor Louis Cheung, Director of the Musculoskeletal Research Laboratory at CUHK, began his academic career by focusing on osteoporotic fracture healing. However, his work with aging patients revealed another significant, under-explored problem. As he noted,

“After more than a decade of work in this area, I recognize that sarcopenia is another critical but under-explored geriatric issue among the hip fracture patients.”

This insight prompted a strategic shift, and his research now primarily targets sarcopenia—the age-related loss of muscle mass and strength affecting up to 40% of older adults. Utilizing advanced technology, his team is investigating the condition’s pathogenesis by zeroing in on the degeneration of the neuromuscular junction (NMJ), aiming to develop new interventions to preserve and regenerate NMJs and combat muscle aging.

Louis Cheung, PhD

Professor and Director
Musculoskeletal Research Laboratory
Department of Orthopaedics and Traumatology
Prince of Wales Hospital
The Chinese University of Hong Kong

To effectively fight age-related muscle loss, Dr. Can Cui, a postdoctoral fellow in Professor Louis Cheung’s lab, explains how they employ a powerful array of techniques focused on the neuromuscular junction.

“One key tool is single-fiber electromyography, SFEMG, which helps us detect early signs of neuromuscular transmission issues such as increased jitter and impulse block, which are indicators of NMJ dysfunction.”

Crucially, they have also developed an optimized ex-vivo electrophysiological protocol using the Aurora Scientific 1200A system to quantitively assess both NMJ and skeletal muscle function, which analyzes everything from tetanic force measurements to fatigue. Furthermore, the team utilizes molecular biology techniques (immunostaining, qPCR, Western blotting) to evaluate relevant proteins and gene expressions. All these diagnostic tools are essential for testing potential interventions in aged mouse models to explore their potential in reversing NMJ degeneration and muscle atrophy.

Can Cui, PhD

Postdoctoral Fellow
Musculoskeletal Research Laboratory
Department of Orthopaedics and Traumatology
Prince of Wales Hospital
The Chinese University of Hong Kong

The Aurora 1200A system has proven to be a game-changer for Professor Cheung’s lab, revolutionizing how they study NMJ function. Its primary advantage is the dual stimulation capability, which is vital for accurately distinguishing between problems that originate within the muscle and those specific to the NMJ itself, achieved through both direct muscle and indirect nerve stimulation.

The specialized stimulating probe, co-designed by Dr. Cui, facilitates precise sciatic nerve stimulation. By establishing optimal and consistent parameters, along with nerve preservation techniques, the lab ensures reproducible results. The system then calculates crucial quantitative metrics, such as neural transmission failure and intratetanic fatigue. This level of detail allows the researchers to detect early NMJ deficits in aging models and evaluate the therapeutic efficacy of interventions with unprecedented high fidelity, effectively bridging the gap between structural observation and functional outcomes.

Looking forward, Professor Louis Cheung’s team is focused on supporting the clinical translation of their promising interventions. A critical next step once preclinical results are mature is initating clinical trials, which necessitates adapting their sophisticated assessment tools from animal models to human subjects.

“For the future human trials, we are establishing a single fiber EMG, the electromyography protocol, in our laboratory to evaluate the NMJ functions in sarcopenia patients. This will be a critical step towards bridging our bench to bedside effort.”

In addition, the team is expanding its scope to osteosarcopenia, an emerging condition combining muscle loss with bone issues, which significantly elevates the risk of fractures. They hypothesize that NMJ function may be more severely impaired in these patients, paving the way for targeted treatments. Recognizing that conventional approaches (exercise and diet) may not feasible for all elderly patients, the lab will continue to explore novel pharmacological strategies, always keeping their ultimate goal of improving the quality of life for aging populations at the forefront.