Phenotypic characterization of gastric sensory neurons in mice

2006 ◽  
Vol 291 (5) ◽  
pp. G987-G997 ◽  
Author(s):  
Klaus Bielefeldt ◽  
Fang Zhong ◽  
H. Richard Koerber ◽  
Brian M. Davis

Recent studies suggest that the capsaicin receptor [transient receptor potential vanilloid (TRPV)1] may play a role in visceral mechanosensation. To address the potential role of TRPV1 in vagal sensory neurons, we developed a new in vitro technique allowing us to determine TRPV1 expression directly in physiologically characterized gastric sensory neurons. Stomach, esophagus, and intact vagus nerve up to the central terminations were carefully dissected and placed in a perfusion chamber. Intracellular recordings were made from the soma of nodose neurons during mechanical stimulation of the stomach. Physiologically characterized neurons were labeled iontophoretically with neurobiotin and processed for immunohistochemical experiments. As shown by action potential responses triggered by stimulation of the upper thoracic vagus with a suction electrode, essentially all abdominal vagal afferents in mice conduct in the C-fiber range. Mechanosensitive gastric afferents encode stimulus intensities over a wide range without apparent saturation when punctate stimuli are used. Nine of 37 mechanosensitive vagal afferents expressed TRPV1 immunoreactivity, with 8 of the TRPV1-positive cells responding to stretch. A small number of mechanosensitive gastric vagal afferents express neurofilament heavy chains and did not respond to stretch. By maintaining the structural and functional integrity of vagal afferents up to the nodose ganglion, physiological and immunohistochemical properties of mechanosensory gastric sensory neurons can be studied in vitro. Using this novel technique, we identified TRPV1 immunoreactivity in only one-fourth of gastric mechanosensitive neurons, arguing against a major role of this ion channel in sensation of mechanical stimuli under physiological conditions.

2016 ◽  
Vol 311 (3) ◽  
pp. L664-L675 ◽  
Author(s):  
Clémence O. Henry ◽  
Emilie Dalloneau ◽  
Maria-Teresa Pérez-Berezo ◽  
Cristina Plata ◽  
Yongzheng Wu ◽  
...  

Cystic fibrosis (CF) is an inherited disease associated with chronic severe lung inflammation, leading to premature death. To develop innovative anti-inflammatory treatments, we need to characterize new cellular and molecular components contributing to the mechanisms of lung inflammation. Here, we focused on the potential role of “transient receptor potential vanilloid-4” (TRPV4), a nonselective calcium channel. We used both in vitro and in vivo approaches to demonstrate that TRPV4 expressed in airway epithelial cells triggers the secretion of major proinflammatory mediators such as chemokines and biologically active lipids, as well as a neutrophil recruitment in lung tissues. We characterized the contribution of cytosolic phospholipase A2, MAPKs, and NF-κB in TRPV4-dependent signaling. We also showed that 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acids, i.e., four natural lipid-based TRPV4 agonists, are present in expectorations of CF patients. Also, TRPV4-induced calcium mobilization and inflammatory responses were enhanced in cystic fibrosis transmembrane conductance regulator-deficient cellular and animal models, suggesting that TRPV4 is a promising target for the development of new anti-inflammatory treatments for diseases such as CF.


2019 ◽  
Author(s):  
Aisling Tynan ◽  
Téa Tsaava ◽  
Manojkumar Gunasekaran ◽  
Isabel Snee ◽  
Tak W. Mak ◽  
...  

AbstractMammals store memories in the nervous and immune systems. Sensory neurons have been implicated in enhancing neurological memory, but whether neurons participate during immunity to novel antigens is unknown. Here, mice rendered deficient in transient receptor potential vanilloid 1 (TRPV1)-expressing sensory neurons, termed “nociceptors,” fail to develop competent antibody responses to KLH and hapten-NP. Moreover, selective optogenetic stimulation of TRPV1 neurons during immunization significantly enhanced antibody responses to antigens. Thus, TRPV1 nociceptors mediate antibody responses to novel antigen, and stimulating TRPV1 nociceptors enhances antibody responses during immunization. This is the first genetic and selective functional evidence that nociceptors are required during immunization to produce antigen-specific antibodies.SummaryThe first genetic and selective functional evidence showing that TRPV1-expressing nociceptors are required for competent antibody responses to novel antigen, and stimulating TRPV1 nociceptors enhances antibody responses to novel antigen.


Cephalalgia ◽  
2011 ◽  
Vol 31 (16) ◽  
pp. 1595-1600 ◽  
Author(s):  
Xiaomei Wei ◽  
Rebecca M Edelmayer ◽  
Jin Yan ◽  
Gregory Dussor

Background: The mechanisms contributing to the pain of migraine are poorly understood although activation of afferent nociceptors in the trigeminovascular system has been proposed as a key event. Prior studies have shown that dural-afferent nociceptors are sensitive to both osmotic and mechanical stimuli. Based on the sensitivity to these stimuli we hypothesized that dural afferents express the osmo/mechano-sensitive channel transient receptor-potential vanilloid 4 (TRPV4). Methods: These studies used in vitro patch-clamp electrophysiology of trigeminal neurons retrogradely labeled from the dura to examine the functional expression of TRPV4. Additionally, we used a rat headache model in which facial/hind paw allodynia following dural stimulation is measured to determine whether activation of meningeal TRPV4 produces responses consistent with migraine. Results: These studies found that 56% and 49% of identified dural afferents generate currents in response to hypotonic solutions and 4α-PDD, respectively. The response to these stimuli indicates that dural afferents express TRPV4. Activation of meningeal TPRV4 using hypotonic solution or 4α-PDD in vivo resulted in both facial and hind paw allodynia that was blocked by the TRPV4 antagonist RN1734. Conclusion: These data indicate that activation of TRPV4 within the meninges produces afferent nociceptive signaling from the head that may contribute to migraine headache.


Cancers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 322 ◽  
Author(s):  
Giorgio Santoni ◽  
Consuelo Amantini

Recently, the finding of cancer stem cells in brain tumors has increased the possibilitiesfor advancing new therapeutic approaches with the aim to overcome the limits of current availabletreatments. In addition, a role for ion channels, particularly of TRP channels, in developing neuronsas well as in brain cancer development and progression have been demonstrated. Herein, we focuson the latest advancements in understanding the role of TRPV2, a Ca2+ permeable channel belongingto the TRPV subfamily in neurogenesis and gliomagenesis. TRPV2 has been found to be expressedin both neural progenitor cells and glioblastoma stem/progenitor-like cells (GSCs). In developingneurons, post-translational modifications of TRPV2 (e.g., phosphorylation by ERK2) are required tostimulate Ca2+ signaling and nerve growth factor-mediated neurite outgrowth. TRPV2overexpression also promotes GSC differentiation and reduces gliomagenesis in vitro and in vivo.In glioblastoma, TRPV2 inhibits survival and proliferation, and induces Fas/CD95-dependentapoptosis. Furthermore, by proteomic analysis, the identification of a TRPV2 interactome-basedsignature and its relation to glioblastoma progression/recurrence, high or low overall survival anddrug resistance strongly suggest an important role of the TRPV2 channel as a potential biomarkerin glioblastoma prognosis and therapy.


Sign in / Sign up

Export Citation Format

Share Document