Endale, M. | bioRxiv Science

bioRxiv2021

Machine learning approaches to identify sleep genes

Genetics impacts sleep, yet, the molecular mechanisms underlying sleep regulation remain elusive. We built machine learning (ML) models to predict genes based on their similarity to known sleep genes. Using a manually curated list of 109 labeled sleep genes, we trained a prediction model on thousands of published datasets, representing circadian, immune, sleep deprivation, and many other processes. Our predictions fit with prior knowledge of sleep regulation and also identify several key genes/pathways to pursue in follow-up studies. We tested one of our findings, the NF-{kappa}B pathway, and showed that its genetic alteration affects sleep duration in mice. Our study highlights the power of ML to integrate prior knowledge and genome-wide data to study genetic regulation of sleep and other complex behaviors.

genomics↗

bioRxiv2020

NF-κB modifies the mammalian circadian clock through interaction with the core clock protein BMAL1

In mammals, the circadian clock coordinates various cell physiological processes, including the inflammatory response. Recent studies suggested a crosstalk between these two pathways. However, the mechanism of how inflammation affects the circadian clock is not well understood. Here, we investigated the role of the proinflammatory transcription factor NF-{kappa}B in regulating clock function. Using a combination of genetic and pharmacological approaches, we show that perturbation of the canonical NF-{kappa}B subunit RELA in the U2OS cellular model altered core clock gene expression. While RELA activation shortened period length and dampened amplitude in these cells, its inhibition lengthened period length and caused amplitude phenotypes. NF-{kappa}B perturbation also altered circadian rhythms in the master suprachiasmatic nucleus (SCN) clock and locomotor activity. We show that RELA, like the clock repressor CRY1, potently repressed the transcriptional activity of BMAL1/CLOCK at the circadian E-box cis-element. Biochemical and biophysical analysis showed that RELA competes with coactivator CBP/p300 for binding to the transactivation domain of BMAL1. This mechanism is further supported by chromatin immunoprecipitation analysis showing that the binding sites of RELA, BMAL1 and CLOCK converge on the E-boxes of clock genes. Taken together, these data support a significant role for NF-{kappa}B in directly regulating circadian clock function and highlight mutual regulation between the circadian and inflammatory pathways.

molecular biology↗