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Leibowitz, B. D.

Publications and source records attributed to Leibowitz, B. D..

2 recordsLinked to original sources

Short-Term Performance Assay Identifies Functional Benefits and Early Toxicity of Longevity Interventions in Mice

Mouse lifespan studies are slow and costly, limiting the number of interventions that have demonstrated robust anti-aging effects. This highlights the need for rapid early-stage screening tools capable of assessing both efficacy and potential side effects. Here, we present a short-term performance assay designed to rapidly profile functional benefits and early toxicity of longevity interventions in mice. Over an 8-week period, mice received one of five candidate anti-aging treatments: 17-estradiol, rapamycin + Smer28, berberine + resveratrol, sildenafil and pinealon. The protocol longitudinally monitored body weight and temperature, and food intake, alongside post-treatment assessments of grip strength, locomotor activity, Y-maze cognition, social behavior, and hematological and urinary parameters. The screen revealed compound-specific phenotypes: 17-estradiol induced significant weight loss, increased grip strength, and dorsal alopecia, consistent with metabolic remodeling. Sildenafil reduced basal body temperature and preserved locomotor activity. Berberine + resveratrol decreased food intake and fasting glucose without major changes in physical performance, resembling caloric restriction-like metabolic effects. Rapamycin + Smer28 modestly improved strength and sociability but induced anemia in 2 of 5 mice, indicating potential dose-dependent toxicity. Pinealon showed a trend toward improved working memory without detectable adverse effects. This multi-parametric approach enables discover healthspan extending interventions facilitating prioritization and dose refinement before committing to full lifespan studies. Finally, to our knowledge, this represents the first comprehensive preclinical aging study in mice fully funded through tokenized decentralized science (DeSci), demonstrating how community-governed, on-chain funding can support resource-intensive in vivo research.

pharmacology and toxicology↗

Engineered Feedback Employing Natural Hypoxia-Responsive Factors Enhances Synthetic Hypoxia Biosensors

DNA-based hypoxia biosensors conditionally express a gene of interest when a cell is in a state of inadequate oxygen supply, which is a feature of several acute and chronic diseases. These biosensors can be deployed in engineered cells to study or treat disease. Although the central mediators of hypoxia responsiveness have been characterized, the dynamics of this response are generally less understood, and there is no general approach to modulate hypoxia biosensors to tune their performance to meet application-specific needs. To address the need for high-performing hypoxia biosensors, we investigated strategies to enhance biosensor performance by identifying minimal promoter choices and positive feedback circuits that both achieved low background and amplified hypoxia-induced gene expression. To generate insight into the mechanisms by which feedback drives differential performance, we developed an explanatory mathematical model. Our analysis suggests a previously unreported dual regulatory mechanism that was necessary to explain the full set of experimental observations and that provides new insights into regulatory dynamics in chronic hypoxia. This study exemplifies the potential of using synthetic gene circuits to perturb natural systems in a manner that uniquely enables the elucidation of novel facets of natural regulation.

synthetic biology↗