Biology subjects

De Siena, G.

Publications and source records attributed to De Siena, G..

4 recordsLinked to original sources

bioRxiv2026

Schwann cell p75NTR sustains persistent pain downstream to NGF through ROS-dependent TRPA1 signaling

Nerve growth factor (NGF) is a key mediator of pain through activation of the high-affinity tropomyosin receptor kinase A (TrkA) and the low-affinity neurotrophin receptor (p75NTR). Although neuronal TrkA signaling is well established, the contribution of non-neuronal cells to NGF- dependent pain remains unclear. Here, we show that NGF and its precursor proNGF engage distinct cellular mechanisms. Intraplantar NGF induced acute nociception, heat hyperalgesia, mechanical allodynia, and cold hypersensitivity, whereas cleavage-resistant proNGF selectively evoked mechanical allodynia and cold hypersensitivity. Pharmacological and cell-specific genetic approaches demonstrated that acute nociception and heat hyperalgesia require neuronal TrkA, whereas mechanical and cold hypersensitivity depend on p75NTR activation in Schwann cells. In Schwann cells, NGF and proNGF induced p75NTR-dependent calcium release, followed by TRPA1 activation, mitochondrial ROS production, and NOX1-dependent oxidative amplification. Inhibition of ROS or TRPA1, or Schwann cell-specific Trpa1 deletion, markedly reduced mechanical allodynia and cold hypersensitivity without affecting acute nociception or heat hyperalgesia. These findings identify a Schwann cell p75NTR-ROS-TRPA1 pathway sustaining persistent pain and highlight non-neuronal p75NTR signaling as a potential therapeutic target.

neuroscience↗

bioRxiv2026

Triptans reprogram Schwann cells to drive medication-overuse headache via β-glycan/TGF-β3 signaling

Medication-overuse headache (MOH) is one of the leading causes of chronic daily headache worldwide and arises from the repeated use of acute anti-migraine medications, including triptans. However, the cellular substrates and intracellular pathways driving this paradoxical chronification remain unknown. Here, using Schwann cell-selective silencing of the 5-HT1B/D receptor, we observed that acute triptan administration counteracts CGRP-induced, endosome-confined cAMP accumulation, preventing the development of periorbital mechanical allodynia in mice. In contrast, prolonged 5-HT1B/D activation in Schwann cells induces epigenetic and transcriptomic dysregulation associated with MOH in mice. Specifically, intronic hypermethylation-driven overexpression of BETAGLYCAN promotes activation of a non-canonical TGF-{beta}-dependent signaling cascade. The resulting TGF-{beta}3 upregulation establishes a feed-forward loop that sustains proalgesic paracrine communication between Schwann cells and primary sensory neurons. Analysis of plasma levels from patients with MOH confirmed elevated TGF-{beta}3 levels specifically associated with triptan-dependent MOH, supporting the translational relevance of these findings. Together, our data identify Schwann cell 5-HT1B/D signaling as a dual mediator of both the acute anti-migraine efficacy and the maladaptive mechanisms underlying MOH. These results provide a conceptual framework for strategies aimed at preserving the therapeutic benefits of triptans while limiting the adverse consequences of chronic administration. One Sentence SummarySchwann cell 5-HT1B/D receptor signaling mediates the dual effects of triptans by acutely inhibiting CGRP-driven nociceptive pathways while chronically promoting epigenetically driven TGF-{beta}3-dependent proalgesic signaling that causes medication-overuse headache.

pharmacology and toxicology↗

bioRxiv2026

Disentangling Schwann Cell and Neuronal TRPA1 Function in Mouse Models of Familial Episodic Pain Syndrome

Familial Episodic Pain Syndrome (FEPS) is a rare inherited disorder characterized by episodes of severe upper-body pain triggered by different stimuli including cold, stress, or fasting. A gain-of-function point mutation (N855S) in the Transient Receptor Potential Ankyrin 1 (TRPA1) ion channel has been identified in affected individuals, altering its biophysical properties, and leading to sustained nociceptive signaling. While TRPA1 is predominantly studied in sensory neurons, recent findings highlight its key modulatory role for Schwann cells in chronic pain. Here, we investigated the cell-specific contributions of mutant TRPA1 (TRPA1*) in FEPS by developing mouse models with TRPA1* selectively expressed in either Schwann cells or sensory neurons, using CRISPR-based and Cre-loxP strategies. Patch-clamp analyses confirmed that TRPA1* exhibits enhanced current responses to agonists compared to wild-type. Through behavioral assays we revealed that TRPA1* expressed in sensory neurons mediates acute nociception, while TRPA1* in Schwann cells drives mechanical allodynia in response to subthreshold doses of TRPA1 agonists and to physiological pain triggers commonly observed in FEPS patients, including fasting, cold exposure, and restraint stress. Pain responses were associated with the increase in reactive oxygen species (ROS) and accumulation of 4-hydroxynonenal (4-HNE) in TRPA1* sciatic nerves and these effects were reduced by a treatment with an antioxidant. We reveal distinct roles of neuronal and non-neuronal TRPA1 in pain and provide novel in vivo models to investigate the mechanisms of chronic pain in FEPS and related channelopathies. Overall, this study offers new insights into the development of targeted therapies for Schwann cell-TRPA1 to relieve pain in affected individuals.

genetics↗

bioRxiv2024

Targeting the Schwann Cell EP2/cAMP Nanodomain to Block Pain but not Inflammation

Analgesia by non-steroidal anti-inflammatory drugs (NSAIDs) is ascribed to inhibition of prostaglandin (PG) biosynthesis and ensuing inflammation. However, NSAIDs have life-threatening side effects, and inhibition of inflammation delays pain resolution. Decoupling the mechanisms underlying PG-evoked pain vs. protective inflammation would facilitate pain treatment. Herein, we reveal that selective silencing of the PGE2 EP2 receptor in Schwann cells via an adeno-associated viral vector abrogates the indomethacin-sensitive component of pain-like responses in mice elicited by inflammatory stimuli without affecting inflammation. In human Schwann cells and in mice, EP2 activation and optogenetic stimulation of adenylyl cyclase evokes a plasma membrane-compartmentalized cyclic adenosine monophosphate (cAMP) signal that, via A-kinase anchor protein-associated protein kinase A, sustains inflammatory pain-like responses, but does not delay their resolution. Thus, an unforeseen and druggable EP2 receptor in Schwann cells, via specific cAMP nanodomains, encodes PG-mediated persistent inflammatory pain but not protective inflammation.

pharmacology and toxicology↗