Involvement of the endogenous hydrogen sulfide/Ca_v3.2 T‐type Ca²⁺ channel pathway in cystitis‐related bladder pain in mice

Abstract

BACKGROUND AND PURPOSEHydrogen sulfide (H2S), generated by enzymes such as cystathionine-g-lyase (CSE) from L-cysteine, facilitates pain signals by activating the Cav3.2 T-type Ca 2+ channels. Here, we assessed the involvement of the CSE/H2S/Cav3.2 pathway in cystitis-related bladder pain. EXPERIMENTAL APPROACHCystitis was induced by i.p. administration of cyclophosphamide in mice. Bladder pain-like nociceptive behaviour was observed and referred hyperalgesia was evaluated using von Frey filaments. Phosphorylation of ERK in the spinal dorsal horn was determined immunohistochemically following intravesical administration of NaHS, an H2S donor. KEY RESULTSCyclophosphamide caused cystitis-related symptoms including increased bladder weight, accompanied by nociceptive changes (bladder pain-like nociceptive behaviour and referred hyperalgesia). Pretreatment with DL-propargylglycine, an inhibitor of CSE, abolished the nociceptive changes and partly prevented the increased bladder weight. CSE protein in the bladder was markedly up-regulated during development of cystitis. Mibefradil or NNC 55-0396, blockers of T-type Ca 2+ channels, administered after the symptoms of cystitis appeared, reversed the nociceptive changes. Further, silencing of Cav3.2 protein by repeated intrathecal administration of mouse Cav3.2-targeting antisense oligodeoxynucleotides also significantly attenuated the nociceptive changes, but not the increased bladder weight. Finally, the number of cells staining positive for phospho-ERK was increased in the superficial layer of the L6 spinal cord after intravesical administration of NaHS, an effect inhibited by NNC 55-0396. CONCLUSION AND IMPLICATIONSEndogenous H2S, generated by up-regulated CSE, caused bladder pain and referred hyperalgesia through the activation of Cav3.2 channels, one of the T-type Ca 2+ channels, in mice with cyclophosphamide-induced cystitis. Abbreviations

T-type Calcium Channels: Functional Regulation and Implication in Pain Signaling

“…The impact of Ca v 3.2 on colonic pain signaling is supported by a recent report from an independent group showing involvement of Ca v 3.2 in butyrate-induced colonic hypersensitivity to colorectal distention in the rat, a model for irritable bowel syndrome (IBS) (38). Similarly, activation/sensitization of Ca v 3.2 by endogenous H 2 S formed by CSE plays critical roles in pancreatic pain accompanying cerulein-induced pancreatitis (8) and in bladder pain accompanying cyclophosphamide-induced cystitis (39). Interestingly, in these pancreatic and bladder pain models, CSE protein is upregulated in the pancreatic and bladder tissues, respectively (8,40).…”

“…Interestingly, in these pancreatic and bladder pain models, CSE protein is upregulated in the pancreatic and bladder tissues, respectively (8,40). Upregulation of Ca v 3.2 protein is also detectable in the DRG in the latter model (39). Collectively, Ca v 3.2 regulated by endogenous H 2 S may serve as a novel therapeutic target for treatment of various types of visceral pain.…”

Hydrogen sulfide induces hypersensitivity of rat capsaicin-sensitive lung vagal neurons: role of TRPA1 receptors

“…For example, the suppression of sustained potassium channel currents has been suggested to be responsible for the NaHS-induced sensitization of rat trigeminal ganglion neurons innervating the temporomandibular joints (11). It has been shown that the Ca v 3.2 T-type Ca 2ϩ channels involves the somatic hyperalgesia induced by the intraplantar injection of NaHS (28,33) and also contributes to the bladder hyperalgesia induced by the intraperitoneal injection of cyclophosphamide (29). Moreover, a recent study concluded that the activation of voltage-gated sodium channels by endogenous H 2 S is vital to the sensitization of colonic dorsal root ganglion neurons induced by heterotypic intermittent stress (44).…”

Endogenous Hydrogen Sulfide Enhances Cell Proliferation of Human Gastric Cancer AGS Cells

“…Primary antibodies used in the present study were: rabbit anti-CSE polyclonal antibody (Sigma-Genosys/Sigma-Aldrich) against a peptide corresponding to the amino acid sequence, (C)80GGTNRYFRR89V, in rat CSE, 14) mouse CBS monoclonal antibody (clone 3E1; Abnova Co., Taipei, Taiwan) and rabbit anti-glyceraldehyde-3-phosphate dehydrogenase (GAPDH) polyclonal antibody (sc-25778; Santa Cruz Biotechnol., Santa Cruz, CA, U.S.A.). We used the polyclonal antibody against rat CSE in the present study, because we have accumulated evidence that this antibody specifically recognizes not only rat and mouse CSE, 15,16) but also human CSE. 17) On the other hand, we used the monoclonal antibody against human CBS, the specificity of which was confirmed in our recent study.…”