Biology subjects

Procaccia, S.

Publications and source records attributed to Procaccia, S..

4 recordsLinked to original sources

bioRxiv2025

Circadian-Related Dynamics of the Endocannabinoid System in Male Mouse Brain

Endocannabinoids (eCBs) and related lipids play crucial roles in brain function, including the regulation of circadian rhythms and sleep. To comprehensively map these molecules, we employed liquid chromatography high-resolution tandem mass spectrometry (LC/HRMS/MS) to quantify 78 lipids across 14 families in seven brain areas of male mice at four time points throughout the day (every six hours), and during sleep initiation. We found that most eCBs from the fatty acids (FAs) family, particularly arachidonic acid (AA), were highly abundant in the mouse brain in all brain areas and during the circadian rhythm. High eCBs abundance was shown in deeper brain areas, while temporal differences using the Cosinor analysis revealed 26 eCBs behaving in a circadian rhythm response, with linolenic acid (LnA) being the only lipid to show rhythmicity across all brain areas. Sleep initiation (ZT1) was associated with increased N-acylphosphatidylethanolamine phospholipase D (NAPE-PLD) activity and N-acylethanolamide (NAE) levels in the cortex and hippocampus, while wake extension (WEx) altered 2-monoacylglycerol (2-MAG) metabolism and increased cannabinoid receptor 1 (CB1) expression. These findings provide a detailed lipidomic map of eCBs and related lipids in the male mouse brain, highlighting their area-specific distribution, circadian regulation, and involvement in sleep/wake transitions. Given the link between sleep disruption and neurodegeneration, future studies should investigate whether the observed eCB dysregulation contributes to sleep disturbances in these conditions, and if targeting these pathways offers novel therapeutic strategies. Significant StatementThis comprehensive study provides a high-dimensional map of eCBs and related lipids in the male mouse brain, revealing intricate spatial and temporal dynamics highlighting the role of these lipids in regulating fundamental physiological processes such as circadian rhythm and sleep.

neuroscience↗

bioRxiv2023

Cannabinoid Combination Targets NOTCH1-Mutated T-ALL Through the Integrated Stress Response Pathway

In T-cell acute lymphoblastic leukemia (T-ALL) more than 50% of cases display autoactivation of Notch1 signaling, leading to oncogenic transformation. We have previously identified a specific chemovar of Cannabis that induces apoptosis by preventing Notch1 maturation in leukemia cells. Here, we isolated three cannabinoids from this chemovar that synergistically mimic the effects of the whole extract. Two were previously known, Cannabidiol (CBD) and Cannabidivarin (CBDV); whereas the third cannabinoid, which we termed 331-18A, was identified and fully characterized in this study. We demonstrated that these cannabinoids act through Cannabinoid receptor type 2 and TRPV1 to activate the integrated stress response pathway by depleting intracellular Ca2+. This is followed by increased mRNA and protein expression of ATF4, CHOP and CHAC1, which is hindered by inhibiting the upstream initiation factor eIF2. The increased abundance of CHAC1 prevents Notch1 maturation, thereby reducing the levels of the active Notch1 intracellular domain, and consequently decreasing cell viability and increasing apoptosis. Treatment with the three isolated molecules resulted in reduced tumor size and weight in-vivo and slowed leukemia progression in mice models. Altogether, this study elucidated the mechanism of action of three distinct cannabinoids in modulating the Notch1 pathway, and constitutes an important step in the establishment of a new therapy for treating NOTCH1-mutated diseases and cancers such as T-ALL.

cancer biology↗

bioRxiv2023

Multi-omic lineage tracing predicts the transcriptional, epigenetic and genetic determinants of cancer evolution

Cancer is a highly heterogeneous disease, where phenotypically distinct subpopulations coexist and could be primed to different fates. Both genetic and epigenetic factors may drive cancer evolution, however little is known about whether and how such a process is pre-encoded in cancer clones. Using single-cell multi-omic lineage tracing and phenotypic assays, we investigate the predictive features of either tumour initiation or drug tolerance within the same cancer population. Clones primed to tumour initiation in vivo display two distinct transcriptional states at the baseline. Remarkably, these states share a distinctive DNA accessibility profile, highlighting an epigenetic basis for tumour initiation. The drug tolerant niche is also largely pre-encoded, but only partially overlaps the tumour-initiating one and evolves following two genetically and transcriptionally distinct trajectories. Our study highlights coexisting genetic, epigenetic and transcriptional determinants of cancer evolution, unravelling the molecular complexity of pre-encoded tumour phenotypes.

genomics↗

bioRxiv2020

Translation and codon usage regulate Argonaute slicer activity to trigger small RNA biogenesis

In the Caenorhabditis elegans germline, thousands of mRNAs are concomitantly expressed with antisense 22G-RNAs, which are loaded into the Argonaute CSR-1. Despite their essential functions for animal fertility and embryonic development, how CSR-1 22G-RNAs are produced remains unknown. Here, we show that CSR-1 slicer activity is primarily involved in triggering the synthesis of small RNAs on the coding sequences of germline mRNAs and post-transcriptionally regulates a fraction of targets. CSR-1-cleaved mRNAs prime the RNA-dependent RNA polymerase, EGO-1, to synthesize 22G-RNAs in phase with ribosome translation in the cytoplasm, in contrast to other 22G-RNAs mostly synthesized in germ granules. Moreover, codon optimality and efficient translation antagonize CSR-1 slicing and 22G-RNAs biogenesis. We propose that codon usage differences encoded into mRNA sequences might be a conserved strategy in eukaryotes to regulate small RNA biogenesis and Argonaute targeting.

molecular biology↗