Chronic gastrointestinal pain is a hallmark of most intestinal pathologies, yet effective treatments remain elusive given the complexity of the underlying mechanisms. Aiming to investigate the intestinal epithelium contribution to visceral pain modulation in dysbiosis context, we first demonstrated that intracolonic instillation of microbe-free fecal supernatants from mice with post-inflammatory dysbiosis induced by dextran sodium sulfate (FS^DSS) provokes visceral hypersensitivity in recipient mice. Epithelium involvement in the response to FS^DSS was analyzed through a novel in vitro approach comprising murine epithelial colon organoids and primary dorsal root ganglia (DRG) neurons. FS^DSS treatment induced growth and metabolic impairment in colon organoids, which revealed a dysbiosis-driven epithelial dysfunction. Notably, the combination of FS^DSS and conditioned medium from FS^DSS-treated colon organoids induced an increase in DRG neuron intrinsic excitability, along with greater immunoreactivity to c-Fos and calcitonin-gene related peptide, implicating an integrated role of both microbial and epithelial products in visceral sensitivity regulation. By investigating the underlying signaling, metabolomic analysis revealed reduced levels of short chain fatty acids in FS^DSS, such as butyrate, acetate, valerate, and propionate. Moreover, transcriptomic analysis of FS^DSS-treated colon organoids showed the dysregulated expression of several signaling factors by which intestinal epithelium may modulate sensory neuron excitability, including proteases, cytokines, neuromodulators, growth factors, and hormones. These findings provide novel insights into the role of gut epithelium in the modulation of sensory neuron excitability under dysbiosis conditions, emphasizing that targeting epithelial-neuronal signaling might represent a promising therapeutic strategy for visceral pain management.

Neuropathy development is a major dose-limiting side effect of anticancer treatments that significantly reduces patient’s quality of life. The inadequate pharmacological approaches for neuropathic pain management warrant the identification of novel therapeutic targets. Mitochondrial dysfunctions that lead to reactive oxygen species (ROS) increase, cytosolic Ca²⁺ imbalance, and lactate acidosis are implicated in neuropathic pain pathogenesis. It has been observed that in these deregulations, a pivotal role is played by the mitochondrial carbonic anhydrases (CA) VA and VB isoforms. Hence, preclinical studies should be conducted to assess the efficacy of two novel selenides bearing benzenesulfonamide moieties, named 5b and 5d, and able to inhibit CA VA and VB against paclitaxel-induced neurotoxicity in mice. Acute treatment with 5b and 5d (30–100 mg/kg, per os – p.o.) determined a dose-dependent and long-lasting anti-hyperalgesic effect in the Cold plate test. Further, repeated daily treatment for 15 days with 100 mg/kg of both compounds (starting the first day of paclitaxel injection) significantly prevented neuropathic pain development without the onset of tolerance to the anti-hyperalgesic effect. In both experiments, acetazolamide (AAZ, 100 mg/kg, p.o.) used as the reference drug was partially active. Moreover, ex vivo analysis demonstrated the efficacy of 5b and 5d repeated treatments in reducing the maladaptive plasticity that occurs to glia cells in the lumbar portion of the spinal cord and in improving mitochondrial functions in the brain and spinal cord that were strongly impaired by paclitaxel-repeated treatment. In this regard, 5b and 5d ameliorated the metabolic activity, as observed by the increase in citrate synthase activity, and preserved an optimal mitochondrial membrane potential (ΔΨ) value, which appeared depolarized in brains from paclitaxel-treated animals. In conclusion, 5b and 5d have therapeutic and protective effects against paclitaxel-induced neuropathy without tolerance development. Moreover, 5b and 5d reduced glial cell activation and mitochondrial dysfunction in the central nervous system, being a promising candidate for the management of neuropathic pain and neurotoxicity evoked by chemotherapeutic drugs.

Conus regius is a marine venomous mollusk of the Conus genus that captures its prey by injecting a rich cocktail of bioactive disulfide bond rich peptides called conotoxins. These peptides selectively target a broad range of ion channels, membrane receptors, transporters, and enzymes, making them valuable pharmacological tools and potential drug leads. C. regius-derived conotoxins are particularly attractive due to their marked potency and selectivity against specific nicotinic acetylcholine receptor subtypes, whose signalling is involved in pain, cognitive disorders, drug addiction, and cancer. However, the species-specific differences in sensitivity and the low stability and bioavailability of these conotoxins limit their clinical development as novel therapeutic agents for these disorders. Here, we give an overview of the main pharmacological features of the C. regius-derived conotoxins described so far, focusing on the molecular mechanisms underlying their potential therapeutic effects. Additionally, we describe adoptable chemical engineering solutions to improve their pharmacological properties for future potential clinical translation.

Persistent pain can be managed with opioids, but their use is limited by the onset of tolerance. Ultramicronized N-palmitoylethanolamine (PEA) in vivo delays morphine tolerance with mechanisms that are still unclear. Since glial cells are involved in opioid tolerance and mast cells (MCs) are pivotal targets of PEA, we hypothesized that a potential mechanism by which PEA delays opioid tolerance might depend on the control of the crosstalk between these cells. Morphine treatment (30 μM, 30 min) significantly increased MC degranulation of RBL-2H3 cells, which was prevented by pre-treatment with PEA (100 μM, 18 h), as evaluated by β-hexosaminidase assay and histamine quantification. The impact of RBL-2H3 secretome on glial cells was studied. Six-hour incubation of astrocytes with control RBL-2H3-conditioned medium, and even more so co-incubation with morphine, enhanced CCL2, IL-1β, IL-6, Serpina3n, EAAT2 and GFAP mRNA levels. The response was significantly prevented by the secretome from PEA pre-treated RBL-2H3, except for GFAP, which was further upregulated, suggesting a selective modulation of glial signaling. In conclusion, ultramicronized PEA down-modulated both morphine-induced MC degranulation and the expression of inflammatory and pain-related genes from astrocytes challenged with RBL-2H3 medium, suggesting that PEA may delay morphine tolerance, regulating MC-astrocyte crosstalk.

MicroRNA-22 (miR-22) plays a pivotal role in the regulation of metabolic processes and has emerged as a therapeutic target in metabolic disorders, including obesity, type 2 diabetes, and metabolic-associated liver diseases. While miR-22 exhibits context-dependent effects, promoting or inhibiting metabolic pathways depending on tissue and condition, current research highlights its therapeutic potential, particularly through inhibition strategies using chemically modified antisense oligonucleotides. This review examines the dual regulatory functions of miR-22 across key metabolic pathways, offering perspectives on its integration into next-generation diagnostic and therapeutic approaches while acknowledging the complexities of its roles in metabolic homeostasis.

Brassicaceae are natural sources of bioactive compounds able to promote gut health. Belonging to this plant family, Camelina sativa is an ancient oil crop rich in glucosinolates, polyunsaturated fatty acids, and antioxidants that is attracting renewed attention for its nutraceutical potential. This work aimed at investigating the therapeutic effects of a defatted seed meal (DSM) of Camelina sativa on the colon damage and the persistent visceral hypersensitivity associated with colitis in rats. Inflammation was induced by the intrarectal injection of 2,4-dinitrobenzenesulfonic acid (DNBS). The acute administration of Camelina sativa DSM (0.1–1 g kg⁻¹) showed a dose-dependent pain-relieving effect in DNBS-treated rats. The efficacy of the meal was slightly enhanced after bioactivation with myrosinase, which increased isothiocyanate availability, and drastically decreased by pre-treating the animals with the selective peroxisome proliferator-activated receptor alpha (PPAR α) receptor antagonist GW6471. Repeated treatments with Camelina sativa DSM (1 g kg⁻¹) meal counteracted the development, as well as the persistence, of visceral hyperalgesia in DNBS-treated animals by reducing the intestinal inflammatory damage and preventing enteric neuron damage. In conclusion, Camelina sativa meal might be employed as a nutraceutical tool to manage persistent abdominal pain in patients and to promote gut healing.