Rebecca Ferrisi

Neutrophil migration involves a dynamic balance of chemoattractant and inhibitory signals. We previously identified hepoxilin A ₃ (HxA ₃ ) as a potent chemoattractant that directs neutrophil migration across intestinal epithelia and showed that endocannabinoids can suppress migration through the cannabinoid 2 receptor (CB ₂ R). Here, we reveal that HxA ₃ uses the transient receptor potential vanilloid type 2 (TRPV2) cation channel to promote transmigration, a process finely tuned by physical TRPV2-CB ₂ R interaction. In resting neutrophils, surface-localized CB ₂ R responding to endocannabinoids suppresses migration, while a small fraction of TRPV2 at the plasma membrane “senses” HxA ₃ . HxA ₃ drives the movement of an intracellular “storage” pool of TRPV2 to the leading edge of migration where physical interaction with CB ₂ R establishes cell surface receptor complexes to direct neutrophil migration. Postactivation, TRPV2 is shunted toward degradation, while CB ₂ R is both replaced and recycled to the plasma membrane to establish a coordinated system capable of maintaining directional fidelity to HxA ₃ gradients. These findings uncover a previously unrecognized layer of neutrophil trafficking regulation.

Background: Positron emission tomography (PET) is a molecular imaging technique that exploits the β⁺ decay of selected radionuclides to enable non-invasive in vivo investigation of biochemical and physiological processes, including early and subclinical disease alterations. Radiotracers are designed to bind specific molecular targets with high affinity and selectivity. Among the targets to which PET devotes increasing attention are G protein-coupled receptors (GPCRs)—the largest class of transmembrane receptors—which orchestrate a wide spectrum of biological outcomes and are widely implicated in human disease. Objectives: This review analyzes patents published between 2020 and 2025 focusing on GPCR-targeted PET radiotracers, highlighting design strategies, radionuclide selection, and translational perspectives across oncology, central nervous system (CNS) disorders, and inflammatory diseases. Results: Patent activity shows that most GPCR-targeted PET tracers are derived from validated ligands adapted for imaging while preserving affinity and selectivity. Oncology patents mainly favor peptide-based or modular metal–chelator platforms enabling radionuclide flexibility and theranostic extension, whereas CNS tracers rely on drug-like small molecules optimized under strict ADME and blood–brain barrier constraints. Increasing emphasis on non-orthosteric, function-sensitive, and dual-targeting approaches reflects a shift toward interrogating GPCR signaling states, while inflammatory indications remain comparatively underrepresented despite clear biological foundations. Conclusions: Current patent trends consolidate GPCR-targeted PET tracers as well-established diagnostic tools while progressively expanding their clinical utility, both as platforms supporting translational research—informing mechanistic insight and drug development—and as components of emerging theranostic strategies across multiple disease areas.

Background: Positron emission tomography (PET) is a molecular imaging technique that exploits the β+ decay of selected radionuclides to enable non-invasive in vivo investigation of biochemical and physiological processes, including early and subclinical disease alterations. Radiotracers are designed to bind specific molecular targets with high affinity and selectivity. Among the targets to which PET devotes increasing attention are G protein-coupled receptors (GPCRs)—the largest class of transmembrane receptors—which orchestrate a wide spectrum of biological outcomes and are widely implicated in human disease. Objectives: This review analyzes patents published between 2020 and 2025 focusing on GPCR-targeted PET radiotracers, highlighting design strategies, radionuclide selection, and translational perspectives across oncology, central nervous system (CNS) disorders, and inflammatory diseases. Results: Patent activity shows that most GPCR-targeted PET tracers are derived from validated ligands adapted for imaging while preserving affinity and selectivity. Oncology patents mainly favor peptide-based or modular metal–chelator platforms enabling radionuclide flexibility and theranostic extension, whereas CNS tracers rely on drug-like small molecules optimized under strict ADME and blood–brain barrier constraints. Increasing emphasis on non-orthosteric, function-sensitive, and dual-targeting approaches reflects a shift toward interrogating GPCR signaling states, while inflammatory indications remain comparatively underrepresented despite clear biological foundations. Conclusions: Current patent trends consolidate GPCR-targeted PET tracers as well-established diagnostic tools while progressively expanding their clinical utility, both as platforms supporting translational research—informing mechanistic insight and drug development—and as components of emerging theranostic strategies across multiple disease areas.

Carnosine (CAR), an endogenous histidine-containing dipeptide, exhibits antioxidant and anti-inflammatory activity in various experimental models; however, its molecular mechanism of action remains poorly understood. Here, we demonstrate that the Michael adduct between CAR and 4-hydroxy-2-nonenal (HNE), which has been detected in previous studies in both in vitro and in vivo settings, mediates its bioactivity, particularly its antioxidant and anti-inflammatory responses, through Nrf2 activation. The CAR–HNE adduct was synthesized and its physicochemical, metabolic, and biological properties were evaluated. CAR–HNE exhibited high stability in biological matrices and retained the ability to transfer HNE to thiol nucleophiles at a slow rate under physiologically relevant conditions, consistent with electrophile-mediated Nrf2 activation. This kinetic behavior limits the cytotoxicity typically associated with free HNE while preserving the redox signaling capacity. CAR–HNE induced dose-dependent Nrf2 activation and NF-κB inhibition in cell-based assays without the hormetic toxicity observed for free HNE. Mechanistically, CAR–HNE may act as a redox-tunable electrophilic reservoir, restoring nucleophilic tone and modulating redox-sensitive transcription factors. In vivo, CAR–HNE attenuated DSS-induced colitis more effectively than equimolar doses of either carnosine or HNE alone. Proteomic analyses revealed modulation of canonical Nrf2-dependent antioxidant pathways. Our findings suggest a conceptual shift in carnosine biology: rather than acting as a classical antioxidant or carbonyl quencher, carnosine functions as a precursor of redox-active electrophilic adducts that transduce anti-inflammatory and antioxidant responses via controlled RCS signaling.

A B S T R A C TBitopic ligands represent a powerful strategy to modulate G protein-coupled receptors by simultaneously engaging orthosteric and allosteric binding sites. In this study, we designed and synthesized two series of dequalinium-based hybrid ligands targeting muscarinic acetylcholine receptors (mAChRs), in which a dequalinium fragment was linked through polymethylene spacers of variable length either to the orthosteric superagonist iperoxo (Deq-X-Iper, 5a–c) or to a molecular portion of the allosteric inverse agonist W84 (Deq-X-W84, 6a–c).Equilibrium and kinetic binding studies at human mAChR subtypes (hM1–hM5) revealed good to high affinity for all compounds and a consistent bitopic mode of action, supported by a spacer-length-dependent enhancement of both orthosteric and allosteric interactions. Functional assays showed that Deq-X-W84 derivatives act as unselective muscarinic antagonists, whereas Deq-X-Iper ligands behave as agonists. Notably, the latter displayed probe-dependent negative allosteric modulation of acetylcholine-induced ERK1/2 phosphorylation at the hM4 receptor, revealing an unexpected functional profile.Docking and molecular dynamics simulations provided a structural rationale for these findings, highlighting stable dualsteric binding poses and linker-dependent optimization of receptor contacts. Overall, these results demonstrate that dequalinium-based bitopic ligands can encode distinct functional outcomes at muscarinic receptors, offering new insights into the design of ligands with tailored signaling profiles.

In the pressing quest of novel treatments for chronic pain, α7 nAChR silent agonists show efficacy as anti-inflammatory modulators and represent a promising strategy. Recent findings reveal that a sulfonium ion can replace the quaternary ammonium nitrogen as an alternative pharmacophore for nAChR silent activation. This study reports the design, synthesis, and electrophysiological evaluation of a new series of sulfonium-based derivatives inspired by the archetypal silent agonist NS6740. Our findings identify NSS-9 as a novel sulfonium α7 silent agonist that effectively alleviates inflammatory pain in a mouse model, highlighting it as a lead compound for further optimization. These results provide insights into the potential of the sulfonium group as a chemotype interacting with the α7 binding site, making it a valuable scaffold for novel α7 silent agonists. Additionally, sulfonium compounds were tested on α9 nAChR, also involved in the cholinergic anti-inflammatory system, identifying one partial agonist and two antagonists.

The design of dualsteric/bitopic receptor ligands as compounds capable of simultaneously interacting with both the orthosteric and an allosteric binding site has gained importance to achieve enhanced receptor specificity and minimize off-target effects. In this work, we reported the synthesis and biological evaluation of a new series of compounds, namely, the RF series, obtained by chemically combining the CB1R ago-positive allosteric modulators (PAM) GAT211 with the cannabinoid receptors (CBRs) orthosteric agonist FM6b. Therefore, RF compounds were designed as dualsteric/bitopic ligands for hCB1R with the aim of obtaining stronger hCB1R agonists or ago-PAMs, with improved receptor subtype selectivity and reduction of central side effects. Unexpectedly, in vitro assays on hCB1R indicated RF compounds were inverse agonists/antagonists, exhibiting different profiles compared to those of parent compounds FM6b and GAT211 and, furthermore, two compounds behaved as hCB2R PAMs. The unpredictable change in the function of these new ligands suggests that the function of cannabinoids is not simply predicted.

Neurodegenerative diseases (NDDs) are progressive multifactorial disorders of the nervous system sharing common pathogenic features, including intracellular misfolded protein aggregation, mitochondrial deficit, and inflammation. Taking into consideration the multifaceted nature of NDDs, development of multitarget-directed ligands (MTDLs) has evolved as an attractive therapeutic strategy. Compounds that target the cannabinoid receptor type II (CB2R) are rapidly emerging as novel effective MTDLs against common NDDs, such as Alzheimer’s disease (AD). We recently developed the first CB2R bitopic/dualsteric ligand, namely FD22a, which revealed the ability to induce neuroprotection with fewer side effects. To explore the potential of FD22a as a multitarget drug for the treatment of NDDs, we investigated here its ability to prevent the toxic effect of β-amyloid (Aβ_25–35 peptide) on human cellular models of neurodegeneration, such as microglia (HMC3) and glioblastoma (U87-MG) cell lines. Our results displayed that FD22a efficiently prevented Aβ_25–35 cytotoxic and proinflammatory effects in both cell lines and counteracted β-amyloid-induced depression of autophagy in U87-MG cells. Notably, a quantitative proteomic analysis of U87-MG cells revealed that FD22a was able to potently stimulate the autophagy–lysosomal pathway (ALP) by activating its master transcriptional regulator TFEB, ultimately increasing the potential of this novel CB2R bitopic/dualsteric ligand as a multitarget drug for the treatment of NDDs.

Alzheimer’s disease (AD) is characterized by massive neuronal death, brain atrophy, and loss of neurons and synapses, which all lead to a progressive cognitive decline. Neuroinflammation has been recently identified as one of the main causes of AD progression, and microglia cells are considered to have a central role in this process. Growing evidence suggests that cannabinoids may be used as preventive treatment for AD. An altered expression of the endocannabinoids (eCBs) and their receptors (CBRs) is reported in several neurodegenerative disorders, including AD. Moreover, the modulation of CBRs demonstrated neuroprotective effects in reducing aggregated protein deposition, suggesting the therapeutic potential of natural and synthetic CBR ligands in the treatment of neurodegenerative proteinopathies. Here, we review the current knowledge regarding the involvement of CBRs in the modulation of microglia activation phenotypes, highlighting the role of neuroinflammation in the pathogenesis of neurodegenerative diseases, like AD. We also provide an overview of recently developed candidate drugs targeting CBRs that may afford a new innovative strategy for the treatment and management of AD.

The endocannabinoid and orexin systems share many biological functions, including wakefulness, stress response, reward processing, and mood. While these systems work against one another with respect to arousal, chronic stress-induced downregulation of both systems often leads to anhedonia or the inability to experience pleasure from natural rewards. In the current study, a 24 h restraint stress test (24 h RST) reduced sucrose preference in adult male and female C57BL/6 mice. Prior to the stressor, subsets of mice were intraperitoneally administered cannabinoid and orexin receptor agonists, antagonists, and combinations of these drugs. Restraint mice that received the cannabinoid receptor type 1 (CB1R) antagonist SR141716A, orexin receptor type 2 (OX2R) agonist YNT-185, and the combination of SR141716A and YNT-185, exhibited less anhedonia compared to vehicle/control mice. Thus, the 24 h RST likely decreased orexin signaling, which was then restored by YNT-185. Receptor colocalization analysis throughout mesocorticolimbic brain regions revealed increased CB1R-OX1R colocalization from SR141716A and YNT-185 treatments. Although a previous study from our group showed additive cataleptic effects between CP55,940 and the dual orexin receptor antagonist (TCS-1102), the opposite combination of pharmacological agents proved additive for sucrose preference. Taken together, these results reveal more of the complex interactions between the endocannabinoid and orexin systems.