Search bioRxiv⌕ Search

Biology subjects

Cicalini, I.

Publications and source records attributed to Cicalini, I..

5 recordsLinked to original sources

Pyruvate promotes ciliogenesis bypassing IFT88 dependency and attenuates DSS-induced colitis

Primary cilia (PC) are important signaling rheostats, yet their biology in colon remains understudied. We previously reported that the presence of PC on colonic fibroblasts in mice (CF) modulates their susceptibility to colitis. Here, we demonstrate that extracellular pyruvate levels influence both ciliary length and ciliogenesis in CF. Pyruvate supplementation to CF enhanced tubulin and histone acetylation, with the latter promoting MAPK signaling and tubulin detyrosination within PC. MAPK-inhibition reduced tubulin detyrosination and shortened ciliary length, while inhibition of -tubulin acetylation specifically affected ciliogenesis. Col6a1cre-Ift88flx/flx mice, lacking ciliary Ift88 gene in Col6a1-expressing CF, displayed reduced ciliogenesis and increased susceptibility to DSS-induced colitis. Surprisingly, in primary CF cultures from these mice, pyruvate supplementation restored PC formation. Moreover, pyruvate administration via drinking water rescued PC formation in Col6a1cre-Ift88flx/flx mice and attenuated DSS-induced colitis. These findings identify pyruvate as a regulator of PC biology in CF and as a therapeutically relevant factor in colitis. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=172 HEIGHT=200 SRC="FIGDIR/small/694572v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@170091dorg.highwire.dtl.DTLVardef@66870corg.highwire.dtl.DTLVardef@12c5124org.highwire.dtl.DTLVardef@834660_HPS_FORMAT_FIGEXP M_FIG Pyruvate promotes ciliogenesis bypassing IFT88 dependency and attenuates DSS-induced colitis C_FIG

pathology↗

TTLL6-mediated Polyglutamylation of PurA Maintains Colonic Crypt Integrity

The tubulin tyrosine ligase-like (TTLL) family comprises enzymes catalyzing posttranslational modifications of tubulin, including glutamylation and glycylation. We previously described a critical role for the monoglycylase TTLL3 in colon. Here, we identified TTLL6 as the predominant polyglutamylase in the colon, specifically expressed in epithelial cells of distal and transverse segments. TTLL6 expression decreases during CRC progression, correlating with poor patient prognosis. Deletion of Ttll6 in mice resulted in elongated colonic crypts, expansion of stem and transit-amplifying compartments, and increased numbers of differentiated epithelial cells. Moreover, Ttll6-deficient mice showed an elevated susceptibility to chemically induced colon carcinogenesis. Notably, we identified the nucleic acid-binding protein PurA as a novel TTLL6 substrate with both proteins mutually required for nuclear localization. Consistently, both nuclear polyglutamylation and PurA were present in the bottom compartment of control colons, but reduced in Ttll6-deficient colons. These findings reveal a TTLL6-PurA axis being critical in maintaining colonic homeostasis.

cell biology↗

Metabolic resilience rules sex-specific pain recovery during hormonal aging: a multi-omics analysis of neuropathy in mice.

Biological aging and sex interact to shape systemic metabolism, yet their role in chronic pain resolution remains unexplored. We hypothesized that metabolic resilience -- the ability to flexibly switch fuel sources and maintain energy homeostasis -- rules successful recovery from nerve injury in a sex-dependent manner during aging. In 12-month-old male and female mice -- corresponding to the perimenopausal phase in females and the onset of hormonal decline in both sexes -- we induced sciatic nerve chronic constriction injury and performed multi-omics profiling during Wallerian degeneration, a phase known to trigger long-term neurobiological remodeling. Aging females exhibited early activation of fatty acid oxidation, increased resting energy expenditure, upregulation of mitochondrial redox enzymes and circulating progesterone and corticosterone. Proteomic and metabolomic analysis revealed pentose phosphate pathway enrichment and gluconeogenesis, supporting redox balance and metabolic flexibility. Conversely, males displayed persistent glycolytic reliance, long-chain acylcarnitine accumulation, suppression of adiponectin and PPAR{gamma}, indicating metabolic inflexibility. Longitudinal behavioral analysis revealed that aging females recovered earlier and more fully than aging males, reversing the pattern previously shown in our adult mouse study, where females developed persistent pain and males recovered rapidly. These patterns highlight a non-linear, sex-specific interaction between biological aging and injury response, where hormonal decline reprograms the metabolic trajectory and reshapes pain outcomes. Metabolic resilience governs sex-specific recovery following nerve injury by directing early systemic adaptations that precede and predict long-term pain trajectories. These results define mechanistically anchored, sex- and age-specific biomarkers, and propose preclinical targets for timely, personalized interventions in age-associated neuropathic pain.

neuroscience↗

Machine Learning-Based Drug Response Prediction Identifies Novel Therapeutic Candidates for Colorectal Cancer Cell Line KM-12

One major hurdle in the discovery of new drugs is the limited capacity of traditional screening methods to efficiently explore the immense space of drug candidates. To bypass this difficulty, computational approaches such as virtual screening (VS) have been developed supported by Machine Learning (ML) models to predict the activities of drug-like molecules on a given target. We developed a ML model for VS of a library of 25 million highly-diverse synthesis-on-demand molecules against the KM-12 colorectal cancer (CRC) cell line. By combining different biological readouts, we discovered compounds with a novel chemical scaffold, not yet described in the context of CRC, with either a prominent cytotoxic or cytostatic effect. This finding underpins the strength of our ML-guided VS protocol in discovering promising CRC drug leads triggering altered biological responses.

cancer biology↗

Inhibition of de novo ceramide biosynthesis affects aging phenotype in an in vitro model of neuronal senescence

Although aging is considered to be an unavoidable event, recent experimental evidence suggests that the process can be delayed, counteracted, if not completely interrupted. Aging is the primary risk factor for the onset and development of neurodegenerative conditions like Alzheimers disease, Parkinsons disease, and Amyotrophic Lateral Sclerosis. Intracellular calcium (Ca2+i) dyshomeostasis, mitochondrial dysfunction, oxidative stress, and lipid dysregulation are critical factors that contribute to senescence-related processes. Ceramides, a class of sphingolipids involved in a wide array of biological functions, are important mediators of cellular senescence, but their role in neuronal aging is still largely unexplored.\n\nIn this study, we investigated the effects of L-cycloserine (L-CS), an inhibitor of de novo ceramide biosynthesis, on the aging phenotype of cortical neurons that have been maintained in culture for 22 days, a setting employed as an in vitro model of cellular senescence. Our findings indicate that aged neurons display, when compared to control cultures, overt dysregulation of cytosolic and subcellular [Ca2+]i levels, mitochondrial dysfunction, increased reactive oxygen species generation, altered synaptic activity as well as the activation of neuronal death-related molecules. Treatment with L-CS (30 {micro}M) positively affected the senescent phenotype, a result accompanied by recovery of neuronal [Ca2+]i signaling, and reduction of mitochondrial dysfunction and reactive oxygen species generation.\n\nThe results suggest that the de novo ceramide biosynthesis may represent a critical intermediate in the molecular and functional cascade leading to neuronal senescence. Our findings also identify ceramide biosynthesis inhibitors as promising pharmacological tools to decrease age-related neuronal dysfunctions.

neuroscience↗