Biology subjects

Silvestri, C.

Publications and source records attributed to Silvestri, C..

3 recordsLinked to original sources

bioRxiv2026

Circadian disruption alters hepatic calcium hemostasis, endocannabinoidome and mitochondria through N -docosahexaenoyl ethanolamide-GPR110 signaling

Circadian rhythm disruption is associated with metabolic and inflammatory disorders; however, the mechanisms linking circadian dysfunction to endocannabinoidome (eCBome) signaling and mitochondrial metabolism remain unclear. In our previous in vivo study, constant light exposure altered hepatic eCBome profiles, reduced N-acylethanolamines (NAEs), increased monoacylglycerols (MAGs), and elevated inflammatory cytokines. Here, we investigated the underlying mechanisms using CRISPR/Cas9-generated BMAL1 knockout (KO) HepG2 cells as an in vitro model of circadian alteration. The BMAL1 KO model showed broad lipid remodeling characterized by increased fatty acids, prostaglandins, and MAGs together with reduced NAEs and enhanced lipid accumulation. These changes were accompanied by increased inflammatory signaling and cytokine production. Among the assessed genes, GPR110 was significantly altered in mice exposed to constant light (in vivo study) and BMAL1 KO model and emerged as a potential mediator linking circadian signaling to mitochondrial function. BMAL1 KO cells also exhibited significantly increased calcium (Ca{superscript 2}+) levels in mitochondria and the endoplasmic reticulum (ER), along with attenuation of mitochondrial and glycolytic ATP production. BMAL1KO did not abolish the rhythmicity of NAEs level over 24 hours from medium deprivation and read ministration except for N-docosahexaenoyl-ethanolamide (DHEA). Further, experiments showed that DHEA acts through GPR110 and suppress inflammatory lipid-associated pathways, enhances ATP production, and increases mitochondrial and ER Ca{superscript 2}+ accumulation and inflammatory signaling. Together, these mitochondrial Ca{superscript 2}+ signaling, and inflammation in hepatocytes, highlighting DHEA-GPR110 signaling as a potential regulator of hepatic metabolic homeostasis. HighlightsCircadian disruption increases hepatic monoacylglycerols and decreases N-acylethanolamines. Circadian disruption decreases ATP production and enhances mitochondrial and endoplasmic reticulum Ca{superscript 2}+ levels in hepatocytes DHEA-GPR110 signaling regulates hepatocytes mitochondrial Ca{superscript 2}+ dynamics and ATP production GPR110-mediated Ca{superscript 2}+ signaling significantly alters hepatocytes glycolysis and glycolytic ATP production

Cell Biology↗

bioRxiv2025

Circadian Disruption Elicits Sex-Specific Gut Microbiota, Endocannabinoidome and Lipid Mediator Responses

Circadian disruption is a pervasive environmental stressor that increases susceptibility to metabolic and inflammatory diseases, yet sex-specific adaptive strategies remain poorly understood. Here, we show that constant light (LL) exposure alters gut microbial communities and triggers sex- and tissue-specific host adaptations in the endocannabinoidome and other bioactive lipids. Using 16S rRNA sequencing, short chain fatty acid (SCFA) quantification, LC-MS/MS lipidomics, and cytokine profiling, we identified divergent coping strategies across brain, metabolic and intestinal tissues and reproductive organs. In females, LL induced microbial restructuring, with enrichment of Rikenellaceae, Butyricicoccaceae, and Alistipes, but these changes were uncoupled from short-chain fatty acids (SCFA) output. Also, they engaged N-acylethanolamine (NAE)-driven endocannabinoidome signaling in the brain (AEA, DHEA, OEA, PEA, SEA), accompanied by omega-6 prostaglandin upregulation and increased cytokines (IL-5, IFN-{gamma}, MIP-2). The 2-monoacyl glycerols (2-MAGs) increased selectively in liver and skeletal muscle, reflecting tissue-specific lipid remodeling. In males, microbial shifts were limited (e.g., Ruminococcaceae depletion, Tuzzerella enrichment), yet LL triggered robust metabolic adaptation resulting in elevated SCFA levels (isobutyric, butyric, isovaleric, valeric acids) in faeces and elevation of several DHA-derived bioactive lipids in different intestinal tissues Few alterations in brain bioactive lipids were found, while several 2-MAGs were elevated skeletal muscles and testes. In contrast, several oxylipins were decreased within subcutaneous but not other adipose tissue depots. Together, the data shows that changes in bioactive lipid levels in response to circadian rhythm disruption are organ- and sex-specific as are alterations in microbiota populations, positioning sex as a key determinant of responses to circadian stress.

biochemistry↗

bioRxiv2020

Gene Deletion Studies Reveal A Critical Role For Prostamide/Prostaglandin F2α Synthase In Prostamide F2α Formation

Prostamide/prostaglandin F synthase (PM/PGFS) is an enzyme with very narrow substrate specificity and is dedicated to the biosynthesis of prostamide and prostaglandin F2. The importance of this enzyme, relative to the aldoketoreductase (AKR) series, in providing functional tissue prostamide F2 levels was determined by creating a line of PM/PGFS gene deleted mice. Deletion of the gene encoding PM/PGFS (fam213b) was accomplished by a two exon disruption. Prostamide F2 levels in WT and PM/PGFS KO mice were determined by LC/MS/MS. Intraocular pressure was measured by tonometry and outflow facility was measured by the iPerfusion method in enucleated mouse eyes. Deletion of fam213b had no observed effect on behavior, appetite, or fertility. Intraocular pressure was significantly elevated by approximately 4 mmHg in PM/PGFS KO mice compared to littermate WT mice. No effect on pressure dependent outflow facility occurred, which is consistent with the typically reported prostanoid effect of increasing outflow through the unconventional pathway. The elevation of intraocular pressure caused by deletion of the gene encoding the PM/PGFS enzyme likely results from a diversion of the endoperoxide precursor pathway to provide increased levels of those prostanoids that raise intraocular pressure, namely prostaglandin D2 (PGD2), thromboxane A2 (TxA2). It follows that PM/PGFS may serve an important regulatory role in the eye by providing PGF2 and prostamide F2 to constrain the influence of those prostanoids that raise intraocular pressure.

pharmacology and toxicology↗