Search bioRxiv⌕ Search

Biology subjects

Contreras, R. E.

Publications and source records attributed to Contreras, R. E..

2 recordsLinked to original sources

Solution-phase indexing by kinetic confinement enables rapid, simple, and instrument-free single cell transcriptional profiling

Existing tools for single cell genomics require complex physical frameworks for the indexing of cellular nucleic acids, including proprietary instrumentation, droplet emulsions, and laborious combinatorial indexing schemes. The complexity and cost of these tools significantly constrains the use of single cell technologies across basic and translational research. Here, we describe an instrument-free method that uses novel, bifunctional indexing reagents to deliver index sequences directly to single cells followed by a biophysical process known as Kinetic Confinement to perform high-fidelity indexing of target molecules across thousands of single cells simultaneously in single-tube, solution-phase reactions. Kinetic Confinement enables simple, fast, and flexible single cell experiments, and allows straightforward scaling to very large sample numbers. We anticipate that assays based on Kinetic Confinement will significantly expand the scope, use, and impact of single cell analysis across fundamental and applied research, as well as within therapeutic development and ultimately applied clinical diagnostics.

genomics↗

Coupling of oxytocin and cholecystokinin pathways in the hypothalamus is required for gut-to-brain homeostatic feeding control

Oxytocin-expressing paraventricular hypothalamic neurons (PVNOT neurons) integrate afferent signals from the gut including cholecystokinin (CCK) to adjust whole-body energy homeostasis. However, the molecular underpinnings by which PVNOT neurons orchestrate gut-to-brain feeding control remain unclear. Here, we show that mice undergoing selective ablation of PVNOT neurons fail to reduce food intake in response to CCK and develop hyperphagic obesity on chow diet. Notably, exposing wildtype mice to a high-fat/high-sugar (HFHS) diet recapitulates this insensitivity towards CCK, which is linked to diet-induced transcriptional and electrophysiological aberrations specifically in PVNOT neurons. Restoring OT pathways in DIO mice via chemogenetics or polypharmacology sufficiently re-establishes CCKs anorexigenic effects. Lastly, by single-cell profiling, we identify a specialized PVNOT neuronal subpopulation with increased {kappa}-opioid signaling under HFHS diet, which restrains their CCK-evoked activation. In sum, we here document a novel (patho)mechanism by which PVNOT signaling uncouples a gut-brain satiation pathway under obesogenic conditions.

neuroscience↗