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Biology subjects

Alexander, R.

Publications and source records attributed to Alexander, R..

2 recordsLinked to original sources

Simultaneous classification of neuroactive compounds in zebrafish

Neuroactive compounds are crucial tools in drug discovery and neuroscience, but it remains difficult to discover neuroactive compounds with new mechanisms of action. To address this need, researchers have developed mid-throughput phenotype-first approaches using zebrafish. This study introduces an open, non-commercial, and extensible hardware/software platform that captures and analyzes drugmodulated phenotypic responses larval zebrafish. We provide full specifications, computer-aided design (CAD) documents, and source code. Accompanying this study, we are also publicly depositing phenotypic data on 3.9 million animals and 34,000 compounds. The data include a high-replicate benchmark set on 14 compounds, a wellcontrolled reference set of 648 known neuroactive compounds, 20 specialized reference sets, a library of 1,520 FDA-approved drugs, 3 screening libraries. This open data resource is curated, structured, tied to extensive metadata, and available under a Creative Commons CC-BY license.

systems biology

Bmal1 integrates mitochondrial metabolism and macrophage activation

Metabolic pathways and inflammatory processes are under circadian regulation. While rhythmic immune cell recruitment is known to impact infection outcomes, whether the circadian clock modulates immunometabolism remains unclear. We find the molecular clock Bmal1 is induced by inflammatory stimulants, including Ifn-{gamma}/lipopolysaccharide (M1) and tumor conditioned medium, to maintain mitochondrial metabolism under these metabolically stressed conditions in mouse macrophages. Upon M1 stimulation, myeloid-specific Bmal1 knockout (M-BKO) renders macrophages unable to sustain mitochondrial function, enhancing succinate dehydrogenase (SDH)-mediated mitochondrial ROS production and Hif-1-dependent metabolic reprogramming and inflammatory damage. In tumor-associated macrophages, the aberrant Hif-1 activation and metabolic dysregulation by M-BKO contribute to an immunosuppressive tumor microenvironment. Consequently, M-BKO increases melanoma tumor burden, while administrating an SDH inhibitor dimethyl malonate suppresses tumor growth. Therefore, Bmal1 functions as a metabolic checkpoint integrating macrophage mitochondrial metabolism, redox homeostasis and effector functions. This Bmal1-Hif-1 regulatory loop may provide therapeutic opportunities for inflammatory diseases and immunotherapy.

cell biology