2,2',4,4'-tetrabromodiphenyl ether (BDE-47) induces wide metabolic changes including attenuated mitochondrial function and enhanced glycolysis in PC12 cells.

Polybrominated diphenyl ethers (PBDEs) are extensively used as brominated flame retardants in various factory products. As environmental pollutants, the adverse effects of PBDEs on human health have been receiving considerable attention. However, the precise fundamental mechanisms of toxicity induced by PBDEs are still not fully understood. In this study, the mechanism of cytotoxicity induced by 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) was investigated by combining Seahorse XFp analysis and mass spectrometry-based metabolomics and flux approaches in PC12 cells, one of the most widely used neuron-like cell lines for investigating cytotoxic effects. The Seahorse results suggest that BDE-47 significantly attenuated mitochondrial respiration and enhanced glycolysis in PC12 cells. Additionally, metabolomics results revealed the reduction of TCA metabolites such as citrate, succinate, aconitate, malate, fumarate, and glutamate after BDE-47 exposure. Metabolic flux analysis showed that BDE-47 exposure reduced the oxidative metabolic capacity of mitochondria in PC12 cells. Furthermore, various altered metabolites were found in multiple metabolic pathways, especially in glycine-serine-threonine metabolism and glutathione metabolism. A total of 17 metabolic features were determined in order to distinguish potentially disturbed metabolite markers of BDE-47 exposure. Our findings provide possible biomarkers of cytotoxic effects induced by BDE-47 exposure, and elicit a deeper understanding of the intramolecular mechanisms that could be used in further studies to validate the potential neurotoxicity of PBDEs in vivo. Based on our results, therapeutic approaches targeting mitochondrial function and the glycolysis pathway may be a promising direction against PBDE exposure.

The (over)use of SMART goals for physical activity promotion: A narrative review and critique.

The SMART acronym (e.g., Specific, Measurable, Achievable, Realistic, Timebound) is a highly prominent strategy for setting physical activity goals. While it is intuitive, and its practical value has been recognised, the scientific underpinnings of the SMART acronym are less clear. Therefore, we aimed to narratively review and critically examine the scientific underpinnings of the SMART acronym and its application in physical activity promotion. Specifically, our review suggests that the SMART acronym: is not based on scientific theory; is not consistent with empirical evidence; does not consider what type of goal is set; is not applied consistently; is lacking detailed guidance; has redundancy in its criteria; is not being used as originally intended; and has a risk of potentially harmful effects. These issues are likely leading to sub-optimal outcomes, confusion, and inconsistency. Recommendations are provided to guide the field towards better practice and, ultimately, more effective goal setting interventions to help individuals become physically active.

Updating goal-setting theory in physical activity promotion: a critical conceptual review.

Goal-setting is a widely used and accepted strategy for promoting physical activity. Locke and Latham's goal-setting theory is the primary theoretical framework for setting goals in psychology and plays a prominent role in physical activity promotion. Recently, however, there have been calls to reconsider current goal-setting practice in this field. Therefore, we aimed to critically review and update the application of goal-setting theory in physical activity promotion, by examining core developments in this theory since 1990. Current practice relies on setting specific 'performance' goals as a means of increasing physical activity (e.g., 10,000 steps; national physical activity guidelines). This approach was initially consistent with key tenets of goal-setting theory. However, since 1990 this theory has evolved to differentiate between performance and learning goals. Both goal types are context-dependent and it is now recognised that, in some cases, performance goals can even be detrimental to the achievement of desired outcomes. Consequently, current practice may be theoretically appropriate for physically active individuals but a different approach (e.g., learning goals) may be preferable for inactive individuals who are new to physical activity (i.e., most of the population). We conclude by discussing implications for policy, research, and practice in goal-setting for physical activity promotion.