Platelet factors attenuate inflammation and rescue cognition in ageing.

Identifying therapeutics to delay, and potentially reverse, age-related cognitive decline is critical in light of the increased incidence of dementia-related disorders forecasted in the growing older population1. Here we show that platelet factors transfer the benefits of young blood to the ageing brain. Systemic exposure of aged male mice to a fraction of blood plasma from young mice containing platelets decreased neuroinflammation in the hippocampus at the transcriptional and cellular level and ameliorated hippocampal-dependent cognitive impairments. Circulating levels of the platelet-derived chemokine platelet factor 4 (PF4) (also known as CXCL4) were elevated in blood plasma preparations of young mice and humans relative to older individuals. Systemic administration of exogenous PF4 attenuated age-related hippocampal neuroinflammation, elicited synaptic-plasticity-related molecular changes and improved cognition in aged mice. We implicate decreased levels of circulating pro-ageing immune factors and restoration of the ageing peripheral immune system in the beneficial effects of systemic PF4 on the aged brain. Mechanistically, we identified CXCR3 as a chemokine receptor that, in part, mediates the cellular, molecular and cognitive benefits of systemic PF4 on the aged brain. Together, our data identify platelet-derived factors as potential therapeutic targets to abate inflammation and rescue cognition in old age.

Effect of a Home-based Walking Intervention on Cardiopulmonary Fitness and Quality of Life Among Men with Prostate Cancer on Active Surveillance: The Active Surveillance Exercise Randomized Controlled Trial.

BACKGROUND: Active surveillance (AS) is standard care for most men with low-risk prostate cancer (PC); yet, many men on AS eventually undergo curative therapy. Interventions to lower the risk of cancer progression and fear of recurrence among men on AS for PC are needed. OBJECTIVE: To determine the effect of aerobic exercise on cardiorespiratory fitness, body size, and quality of life (QOL) among men on AS for PC. DESIGN, SETTING, AND PARTICIPANTS: We conducted a 1:1 randomized controlled trial among 51 men with low-risk PC who elected AS. Participants were enrolled at the University of California, San Francisco. INTERVENTION: The 16-wk intervention included a home-based walking program with a nonlinear exercise prescription tailored to baseline fitness level, heart rate monitor, and weekly phone call with an exercise physiologist. Controls received printed materials. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Cardiorespiratory fitness was measured using VO2peak; secondary outcomes included change in body size, anxiety, and QOL. Analyses were based on intention to treat. RESULTS AND LIMITATIONS: Between 2016 and 2021, we randomized 51 men to intervention (n = 26) or control (n = 25). Follow-up was 88% (45/51), 85% (22/26) in the intervention and 92% (23/25) in the control group. At 16 wk, the intervention group had a higher mean VO2peak than the control group (31.9 ± 4.7 vs 27.2 ± 4.8 ml/kg/min; group × time effect p value: <0.001). Additionally, the intervention group reported less fear of PC recurrence and urinary obstruction/irritation, while controls reported more of these two QOL measures, from 0 to 16 wk (p = 0.04 and 0.03, respectively). Two participants discontinued the intervention, including one due to knee pain related to the study. CONCLUSIONS: A home-based walking program improved VO2peak and reduced urinary obstruction/irritation and fear of recurrence among men on AS for PC. PATIENT SUMMARY: Moderate to vigorous aerobic exercise improves fitness and quality of life among men on active surveillance for prostate cancer.