👤 Karly Zacharia

Increasing physical activity is recommended for secondary stroke prevention. Remote telehealth delivery of complex stroke interventions (e.g. exercise) offers potential to meet the challenges of accessible stroke care for all survivors. However, the feasibility of remotely evaluating recommended outcomes, such as device-measured physical activity via wearable technology, is unknown. Furthermore, the effectiveness of physical activity interventions aimed at improving long-term physical activity for people with stroke is unclear. To evaluate the feasibility of remote measurement of physical activity via a research grade wearable device in the ENAbLE Pilot trial and report the effect of the physical activity intervention on device- and self-report measure physical activity. Analyses of secondary outcomes from a randomised trial (ENAbLE Pilot ACTRN12620000189921) involving adults more than 3 months to 10 years post stroke or TIA who were able to walk independently (with or without aid). Physical activity was measured using the International Physical Activity Questionnaire (IPAQ; self-report measure) and activPAL physical activity device. Feasibility outcomes included proportion of the IPAQ collected, and proportion of activPAL devices returned and days of valid data. To assess the effect of the intervention on physical activity outcomes, we used descriptive statistics and linear mixed models. Nearly all self-report (99%) and over three quarters (80%) of device-based measurements were available for analyses. No statistically significant differences in device measured physical activity were identified between participants who received the physical activity intervention and those who did not at the 3- or 6-month timepoints. Participants who undertook the physical activity intervention were more active at 12-months than non-physical activity intervention participants (activPAL measured time spent in moderate to vigorous physical activity (MVPA) 0.31 95% CI [0.07 to 0.55] hours/day, light physical activity (LPA) 0.22 [0.05 to 0.39] hours/day and daily step count 2321 [578 to 4064] steps). No statistically significant differences between groups were identified in the type of physical activity undertaken (IPAQ data), except at 12-months, when walking activity was greater in physical activity intervention participants. Remote measurement of physical activity using a wearable device after stroke and via self-report is feasible. The piloted physical activity intervention shows potential to improve physical activity. Show less

Stem cells are defined by their ability to self-renew and differentiate, both shown in multiple studies to be regulated by metabolic processes. To decipher metabolic signatures of self-renewal in blastocyst-derived stem cells, we compared early differentiating embryonic stem cells (ESCs) and their extra-embryonic counterparts, trophoblast (T)SCs to their self-renewing counterparts. A metabolomics analysis pointed to the desaturation of fatty acyl chains as a metabolic signature of differentiating blastocyst-derived SCs via the upregulation of delta-6 desaturase (D6D; FADS2) and delta-5 desaturase (D5D; FADS1), key enzymes in the biosynthesis of polyunsaturated fatty acids (PUFAs). The inhibition of D6D or D5D by specific inhibitors or SiRNA retained stemness in ESCs and TSCs, and attenuated endoplasmic reticulum (ER) stress-related apoptosis. D6D inhibition in ESCs upregulated stearoyl-CoA desaturase-1 (Scd1), essential to maintain ER homeostasis. In TSCs, however, D6D inhibition downregulated Scd1. TSCs show higher Scd1 mRNA expression and high levels of monounsaturated fatty acyl chain products in comparison to ESCs. The addition of oleic acid, the product of Scd1 (essential for ESCs), to culture medium, was detrimental to TSCs. Interestingly, TSCs express a high molecular mass variant of Scd1 protein, hardly expressed by ESCs. Taken together, our data suggest that lipid desaturation is a metabolic regulator of the balance between differentiation and self-renewal of ESCs and TSCs. They point to lipid polydesaturation as a driver of differentiation in both cell types. Monounsaturated fatty acids (MUFAs), essential for ESCs are detrimental to TSCs. Show less