bims-ciryme 2024-05-05 papers

Cell Stem Cell. 2024 Apr 27. pii: S1934-5909(24)00140-1. [Epub ahead of print]

The epidermal circadian clock integrates and subverts brain signals to guarantee skin homeostasis.

In mammals, the circadian clock network drives daily rhythms of tissue-specific homeostasis. To dissect daily inter-tissue communication, we constructed a mouse minimal clock network comprising only two nodes: the peripheral epidermal clock and the central brain clock. By transcriptomic and functional characterization of this isolated connection, we identified a gatekeeping function of the peripheral tissue clock with respect to systemic inputs. The epidermal clock concurrently integrates and subverts brain signals to ensure timely execution of epidermal daily physiology. Timely cell-cycle termination in the epidermal stem cell compartment depends upon incorporation of clock-driven signals originating from the brain. In contrast, the epidermal clock corrects or outcompetes potentially disruptive feeding-related signals to ensure the optimal timing of DNA replication. Together, we present an approach for cataloging the systemic dependencies of daily temporal organization in a tissue and identify an essential gate-keeping function of peripheral circadian clocks that guarantees tissue homeostasis.

Keywords: aging; circadian; homeostasis; peripheral clocks; stem cells; systemic communication

DOI: https://doi.org/10.1016/j.stem.2024.04.013

Commun Integr Biol. 2024 ;17(1): 2341050

A single incidental dark pulse during daytime attenuated food anticipatory behavior.

Khaviya Balaji, S K Tahajjul Taufique, Melody Shen, David E Ehichioya, Sofia Farah, Shin Yamazaki.

Using an open-source operant feeding device (FED3), we measured food-seeking nose poking behavior in mice. When the mice were exposed to 4 h restricted feeding at night, all mice exhibited robust food anticipatory nose poking starting ~4 h before scheduled mealtime. When the light-dark cycle was advanced by 6 h, mice exhibited two distinct bouts of anticipatory poking, one corresponding to actual mealtime which continued at the same time of day, and one corresponding to predicted mealtime which shifted parallel with the light-dark cycle. Likewise, two similar bouts of food-seeking behavior appeared when the light-dark cycle was delayed for 9 h. These data suggest that food anticipatory behavior is encoded to a circadian oscillator that entrains to the light-dark cycle. Two weeks after advancing the light-dark cycle, mice incidentally received a 3.5 h dark pulse in the middle of the day. This single dark pulse had a negligible effect on running wheel behavior but caused a temporary attenuation of both food anticipatory poking and pellet intake. These results suggest that the circadian oscillator controlling food anticipatory poking is sensitive to light disruption and that proper food anticipation is critical for sufficient food intake during temporally restricted feeding.

Keywords: Circadian rhythm; extra-SCN pacemaker; food anticipation; food seeking behavior; light entrainment; non-canonical circadian oscillator; operant; reward

DOI: https://doi.org/10.1080/19420889.2024.2341050

Science. 2024 May 03. 384(6695): 563-572

Brain-muscle communication prevents muscle aging by maintaining daily physiology.

Arun Kumar, Mireia Vaca-Dempere, Thomas Mortimer, Oleg Deryagin, Jacob G Smith, Paul Petrus, Kevin B Koronowski, Carolina M Greco, Jessica Segalés, Eva Andrés, Vera Lukesova, Valentina M Zinna, Patrick-Simon Welz, Antonio L Serrano, Eusebio Perdiguero, Paolo Sassone-Corsi, Salvador Aznar Benitah, Pura Muñoz-Cánoves.

A molecular clock network is crucial for daily physiology and maintaining organismal health. We examined the interactions and importance of intratissue clock networks in muscle tissue maintenance. In arrhythmic mice showing premature aging, we created a basic clock module involving a central and a peripheral (muscle) clock. Reconstituting the brain-muscle clock network is sufficient to preserve fundamental daily homeostatic functions and prevent premature muscle aging. However, achieving whole muscle physiology requires contributions from other peripheral clocks. Mechanistically, the muscle peripheral clock acts as a gatekeeper, selectively suppressing detrimental signals from the central clock while integrating important muscle homeostatic functions. Our research reveals the interplay between the central and peripheral clocks in daily muscle function and underscores the impact of eating patterns on these interactions.

DOI: https://doi.org/10.1126/science.adj8533