Platelet-rich plasma-derived exosomes boost mesenchymal stem cells to promote peripheral nerve regeneration.

Peripheral nerve injury (PNI) remains a severe clinical problem with debilitating consequences. Mesenchymal stem cell (MSC)-based therapy is promising, but the problems of poor engraftment and insufficient neurotrophic effects need to be overcome. Herein, we isolated platelet-rich plasma-derived exosomes (PRP-Exos), which contain abundant bioactive molecules, and investigated their potential to increase the regenerative capacity of MSCs. We observed that PRP-Exos significantly increased MSC proliferation, viability, and mobility, decreased MSC apoptosis under stress, maintained MSC stemness, and attenuated MSC senescence. In vivo, PRP-Exo-treated MSCs (pExo-MSCs) exhibited an increased retention rate and heightened therapeutic efficacy, as indicated by increased axonal regeneration, remyelination, and recovery of neurological function in a PNI model. In vitro, pExo-MSCs coculture promoted Schwann cell proliferation and dorsal root ganglion axon growth. Moreover, the increased neurotrophic behaviour of pExo-MSCs was mediated by trophic factors, particularly glia-derived neurotrophic factor (GDNF), and PRP-Exos activated the PI3K/Akt signalling pathway in MSCs, leading to the observed phenotypes. These findings demonstrate that PRP-Exos may be novel agents for increasing the ability of MSCs to promote neural repair and regeneration in patients with PNI.

Intervention of muscle-building and antifrailty exercise combined with Baduanjin for frailty of different functional levels: study protocol for a randomised controlled trial.

INTRODUCTION: Frailty has been currently considered as a multidimensional concept, including physical, cognitive and social frailty. Frailty has also been associated with a range of adverse events, which might increase the risks of disability, falls, fractures, delirium and death. Increasing evidence has shown that multicomponent exercise training can improve physical and cognitive function, delay or reverse frailty. However, there is still a lack of exercise intervention programmes for the frail older adults in China. This trial aims to investigate the effects of the muscle-building and antifrailty exercise combined with Baduanjin on the physical function of frail older adults, as well as the effectiveness and safety of the intervention. METHODS AND ANALYSIS: This study is a prospective randomised controlled trial. A total of 192 patients, aged 70 years or older, who are diagnosed as prefrailty or frailty based on the Fried criteria will be included. Prior written and informed consent will be obtained from every subject. These subjects will be randomly assigned to the exercise intervention group (n=96) and the control group (n=96). The exercise intervention group will undergo different exercise programmes for different levels of physical function. They will perform the muscle-building and antifrailty exercise three times per week for 30-60 min for 24 weeks. The control group will implement health education on frailty and maintain the old lifestyle without any intervention.The primary outcomes include the change in frailty and functional capacity, assessed according to the Fried Scale and the Short Physical Performance Battery. Secondary outcomes include the changes in body composition, Activities of daily living, Mini-Mental State Examination, The Geriatric Depression Scale-15 and the haematological indicators. ETHICS STATEMENT: The study has been approved by the Medical Ethics Committee of the PLA General Hospital (approval no.: S2022-600-02). TRIAL REGISTRATION NUMBER: ChiCTR2300070535.

Prevalence of sarcopenia under different diagnostic criteria and the changes in muscle mass, muscle strength, and physical function with age in Chinese old adults.

BACKGROUND: At present, there are several diagnostic criteria of sarcopenia were used in China, and the diagnostic criteria were not unified. This study aims to investigate the consistency between the latest sarcopenia diagnostic criteria Asian Working Group for Sarcopenia(AWGS 2019) and other common diagnostic criteria. The changes of muscle mass, muscle strength and physical function with age and their effects on the diagnosis of sarcopenia were also analyzed. METHODS: A total of 1009 men aged ≥60 years were enrolled from multiple communities. Skeletal muscle mass index, grip strength and 6 m gait speed were measured. The consistency of AWGS 2019 with other diagnostic criteria was analyzed and the trends of these three indicators were observed. The differences of muscle mass, muscle strength and function among different diagnostic criteria and age groups were evaluated. In addition, the change trends of these three indicators with age were observed. RESULTS: According to AWGS 2019 diagnostic criteria, the incidence of sarcopenia in male aged 60-69 years, 70-79 years and over 80 years was 1.5%, 9.6% and 33.1%, respectively. AWGS 2019 was highly consistent with other diagnostic criteria (Kappa = 0.66-0.80, P < 0.01), except the Foundation for the National Institutes of Health(FNIH) (Kappa = 0.32, P < 0.01). When AWGSA2019 diagnostic criteria are applied, the prevalence of decreased muscle strength (39.1%) and physical function (46.4%) was significantly higher than that of low muscle mass (35.9%) in the men over 80 years old. Muscle strength (P < 0.01) and function (P < 0.01) decreased at the same rate with age, both of which were more significant than muscle mass (P < 0.01). CONCLUSION: AWGS 2019 was highly consistent with other criteria. Maintaining muscle mass should be the focus of attention before age 80, while improving muscle strength and function should be focused after age 80 to prevent disability.