Biology subjects

Piomelli, D.

Publications and source records attributed to Piomelli, D..

10 recordsLinked to original sources

bioRxiv2026

Glycosylation of anandamide and other bioactive N-acylethanolamines in mammalian cells and tissues

N-acylethanolamines (NAEs), including the endocannabinoid anandamide, are bioactive fatty acid amides that are normally hydrolyzed by fatty acid amide hydrolase (FAAH) or N-acyl acid amidohydrolase (NAAA). Strikingly, when canonical NAE degradation is blocked, NAE levels do not increase indefinitely but instead reach a plateau. This apparent metabolic ceiling suggests that additional, underexplored pathways contribute to NAE homeostasis. Identifying these pathways is essential to determine whether NAEs are converted into inactive metabolites or products with distinct biological properties. Here, we identify NAE glycosylation as a metabolic pathway that links endocannabinoid-related lipid metabolism to glycosphingolipid turnover. We synthesized glycosylated NAEs and their isotope-encoded standards and developed targeted LC-MS/MS assays to monitor their enzymatic processing and quantify their abundance in mouse and human cells, tissues, and plasma. We show that non-lysosomal glucosylceramidase GBA2 transfers glucose or galactose to anandamide, N-oleoylethanolamine and N-palmitoylethanolamine, and lysosomal glucosylceramidase GCase hydrolyses {beta}-Glycosylated-NAEs ({beta}-Glyco-NAE) back to their parent NAEs. {beta}-Glyco-NAEs occur endogenously in macrophages and neuronal cells, increase when canonical NAE degradation is impaired, and accumulate in human samples with GCase deficiency, including Gaucher disease and GBA1-associated Parkinsons disease. {beta}-Glyco-NAEs do not engage the cannabinoid receptors, TRPV1, or PPAR, and potentiate inflammatory cytokine release, including IL6 and TNF, from microglia. Based on these findings, we pose that GBA2-dependent NAE glycosylation may constitute an overflow lipid-remodeling pathway that connects NAE metabolism to lysosomal dysfunction, inflammation and neurodegeneration.

biochemistry↗

bioRxiv2026

Metabolic reallocation in spinal cord oligodendrocytes drives chronic pain via neuronal β-amyloid production

Peripheral injury reprograms metabolism in spinal cord oligodendrocytes, initiating a molecular cascade that drives chronic pain via neuronal {beta}-amyloid (A{beta}) release. After injury, mouse spinal oligodendrocytes downregulate myelin protein synthesis and upregulate lipid biosynthesis--but reroute lipids toward neuroplastic remodeling and away from myelin maintenance. This metabolic reallocation disrupts myelin integrity and axonal function, causing neuronal accumulation of amyloid precursor protein, enhanced expression of its processing {beta}-secretase BACE1, and local release of A{beta} peptides. Blocking A{beta} production or clearing A{beta} deposits stops the transition to pain chronicity. Deleting the lysosomal lipid hydrolase NAAA in oligodendrocytes prevents both injury-induced A{beta} production and chronic pain development. The findings identify an unexpected mechanistic link between chronic pain and Alzheimers-like neurodegeneration, positioning A{beta} as a target for therapeutic intervention.

neuroscience↗

bioRxiv2025

Metabolic reprogramming in the spinal cord drives the transition to pain chronicity

Acute injuries can progress into painful states that endure long after healing. The mechanisms underlying this transition remain unclear, but metabolic adaptations to the bioenergy demands imposed by injury are plausible contributors. Here we show that peripheral injury activates AKT/mTORC1 in afferent segments of the mouse spinal cord, redirecting local core metabolism toward biomass production while simultaneously suppressing autophagy-mediated biomass reclamation. This metabolic shift supports neuroplasticity, but creates a resource bottleneck that depletes critical spinal cord nutrients. Preventing this depletion with a modified diet normalizes biomass generation and autophagy and halts the transition to chronic pain. This effect, observed across multiple pain models, requires activation of the nutrient sensors, sirtuin-1 and AMPK, as well as restoration of autophagy. The findings identify metabolic reprogramming and consequent autophagy suppression as key drivers of the progression to pain chronicity and highlight nutritional and pharmacological interventions that could prevent this progression after surgery or other physical traumas.

neuroscience↗

bioRxiv2022

A preclinical model of THC edibles that produces high-dose cannabimimetic responses

No preclinical experimental approach enables the study of voluntary oral consumption of high-concentration {Delta}9-tetrahydrocannabinol (THC) and its intoxicating effects, mainly owing to the aversive response of rodents to THC that limits intake. Here we developed a palatable THC formulation and an optimized access paradigm in mice to drive voluntary consumption. THC was formulated in chocolate gelatin (THC-E-gel). Adult male and female mice were allowed ad libitum access for 1 and 2 h. Cannabimimetic responses (hypolocomotion, analgesia, and hypothermia) were measured following access. Levels of THC and its metabolites were measured in blood and brain tissue. Acute acoustic startle responses were measured to investigate THC-induced psychotomimetic behavior. When allowed access for 2 h to THC-E-gel on the second day of a three-day exposure paradigm, adult mice consumed up to {approx}30 mg/kg over 2 h which resulted in robust cannabimimetic behavioral responses (hypolocomotion, analgesia and hypothermia). Consumption of the same gelatin decreased on the following 3rd day of exposure. Pharmacokinetic analysis show that THC-E-gel consumption led to parallel accumulation of THC and its psychoactive metabolite, 11-OH-THC, in brain, a profile that contrasts with the known rapid decline in brain 11-OH-THC levels following THC intraperitoneal (i.p.) injections. THC-E-gel consumption increased the acoustic startle response in males but not in females, demonstrating a sex-dependent effect of consumption. Thus, while voluntary consumption of THC-E-gel triggered equivalent cannabimimetic responses in male and female mice, it potentiated acoustic startle responses preferentially in males. We build a dose-prediction model that included cannabimimetic behavioral responses elicited by i.p. versus THC-E-gel to test the accuracy and generalizability of this experimental approach and found that it closely predicted the measured acoustic startle results in males and females. In summary, THC-E-gel offers a robust preclinical experimental approach to study cannabimimetic responses triggered by voluntary consumption in mice, including sex-dependent psychotomimetic responses.

animal behavior and cognition↗

bioRxiv2022

Microglia Depletion Selectively Eliminates a Singular Form of Hippocampal Long Term Potentiation

There has been considerable recent interest in the possibility that microglia contribute to synaptic plasticity and some forms of learning. We report here that elimination of the cells in young adult male mice with a 7-12 day treatment with an antagonist (PLX5622) of the colony stimulating factor 1 receptor causes a profound but highly selective impairment to long-term potentiation (LTP) expressed by lateral perforant path (LPP) synapses with the dentate gyrus. Input/output functions and frequency facilitation to repetitive stimulation were not measurably affected. Direct infusion of PLX5622 into slices from naiive mice did not reduce the magnitude of LPP-LTP. Microglial depletion had no detectable effect on LTP in either the medial perforant path input to the dentate gyrus or the Schaffer-commissural projections between fields CA3 and CA1. We conclude that microglia discretely regulate the unusual form of LTP expressed by the LPP and thus exert region-specific effects on circuit function within hippocampus.

neuroscience↗

bioRxiv2022

ADOLESCENT EXPOSURE TO LOW-DOSE THC DISRUPTS ENERGY BALANCE AND ADIPOSE ORGAN HOMEOSTASIS IN ADULTHOOD

One of cannabis most iconic effects is the stimulation of hedonic high-calorie eating - the munchies - yet habitual cannabis users are on average leaner than non-users. We asked whether this unexpected phenotype might result from lasting changes in energy balance established during adolescence, when habitual use of the drug often begins. We found that daily low-dose administration of cannabis intoxicating constituent, {Delta}9-tetrahydrocannabinol (THC), to adolescent mice causes an adult metabolic phenotype characterized by reduced fat mass, increased lean mass and utilization of fat as fuel, partial resistance to diet-induced obesity and dyslipidemia, and enhanced thermogenesis. Multi-omics analyses revealed that this phenotype is associated with multiple molecular anomalies in the adipose organ, which include ectopic overexpression of muscle-associated proteins and heightened anabolic processing. Thus, adolescent exposure to THC may promote an enduring pseudo-lean state that superficially resembles healthy leanness but might in fact be rooted in adipose organ dysfunction.

pharmacology and toxicology↗

bioRxiv2022

Targeting NAAA counters dopamine neuron loss and symptom progression in mouse models of Parkinson's disease

The lysosomal cysteine hydrolase N-acylethanolamine acid amidase (NAAA) deactivates the lipidderived mediator palmitoylethanolamide (PEA), an endogenous PPAR- agonist that is critically involved in the control of inflammation and nociception. In this study, we asked whether NAAA-regulated PEA signaling might contribute to the pathogenesis of Parkinsons disease (PD), a neurodegenerative disorder characterized by progressive loss of nigrostriatal dopamine neurons. Analyses of postmortem brain cortex and premortem blood-derived exosomes found elevated levels of NAAA expression in persons with PD compared to age-matched controls. Furthermore, in vitro experiments showed that the dopaminergic neurotoxins, 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), enhanced NAAA expression and lowered PEA content in human SH-SY5Y cells. A similar effect was observed in dopamine neurons and, subsequently, in microglia following 6-OHDA injection in mice. Importantly, deletion of the Naaa gene or pharmacological inhibition of NAAA activity markedly attenuated both dopamine neuron death and parkinsonian symptoms in mice treated with 6-OHDA or MPTP. The results identify NAAA-regulated PEA signaling as a control node for dopaminergic neuron survival and a potential target for therapeutic intervention in PD.

pharmacology and toxicology↗

bioRxiv2022

N-acylethanolamine acid amide hydrolase is a novel target for drugs against SARS-CoV-2 and Zika virus

Several compounds have been tested against SARS-CoV-2; at present, COVID-19 treatments decrease the deleterious inflammatory response and acute lung injury. However, the best therapeutic response would be expected by combining anti-inflammatory properties, while concomitantly blocking viral replication. These combined effects should drastically reduce both infection rate and severe complications induced by novel SARS-CoV-2 variants. Therefore, we explored the antiviral potency of a class of anti-inflammatory compounds that inhibit the N-Acylethanolamine acid amidase (NAAA). This enzyme catalyzes the hydrolysis of palmitoylethanolamide (PEA), a bioactive lipid that mediates anti-inflammatory and analgesic activity through the activation of peroxisome proliferator receptor- (PPAR-). Similarly, this pathway is likely to be a significant target to impede viral replication since PPAR- activation leads to dismantling of lipid droplets, where viral replication of Flaviviruses and Coronaviruses occurs. Here, we show that either genetic or pharmacological inhibition of the NAAA enzyme leads to five-fold reduction in the replication of both SARS-CoV-2 and ZIKV in various cell lines. Once NAAA enzyme is blocked, both ZIKV and SARS CoV-2 replication decrease, which parallels a sudden five-fold decrease in virion release. These effects induced by NAAA inhibition occurs concomitantly with stimulation of autophagy during infection. Remarkably, parallel antiviral and anti-inflammatory effects of NAAA antagonism were confirmed in ex-vivo experiments, within SARS-CoV-2 infected human PBMC cells, in which both viral genomes and TNF- production drop by ~60%. It is known that macrophages contribute to viral spread, excessive inflammation and macrophage activation syndrome that NAAA inhibitors might prevent, reducing the macrophage-induced acute respiratory distress syndrome and subsequent death of COVID-19 patients.

microbiology↗

bioRxiv2019

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↗

bioRxiv2018

Elevated plasma ceramide levels in post-menopausal women

Circulating ceramide levels are abnormally elevated in age-dependent pathologies such as cardiovascular diseases, obesity and Alzheimers disease. Nevertheless, the potential impact of age on plasma ceramide levels has not yet been systematically examined. In the present study, we quantified a focused panel of plasma ceramides and dihydroceramides in a cohort of 164 subjects (84 women) 19 to 80 years of age. After adjusting for potential confounders, multivariable linear regression analysis revealed a positive association between age and ceramide (d18:1/24:0) ({beta} (SE) = 5.67 (2.38); p = .0198) and ceramide (d18:1/24:1) ({beta} (SE) = 2.88 (.61); p < .001) in women, and between age and ceramide (d18:1/24:1) in men ({beta} (SE) = 1.86 (.77); p = .0179). In women of all ages, but not men, plasma ceramide (d18:1/24:1) was negatively correlated with plasma estradiol (r = -0.294; p = .007). Finally, in vitro experiments in human cancer cells expressing estrogen receptors showed that incubation with estradiol (10 nM, 24 h) significantly decreased ceramide accumulation. Together, the results suggest that aging is associated with an increase in circulating ceramide levels, which in post-menopausal women may be at least partially dependent on lower estradiol levels.

biochemistry↗