title: Sexual Dimorphism in a Reciprocal Interaction of Ryanodine and IP3Receptors in the Induction of Hyperalgesic Priming.
abstract: Hyperalgesic priming, a model of pain chronification in the rat, is mediated by ryanodine receptor-dependent calcium release. Although ryanodine induces priming in both sexes, females are 5 orders of magnitude more sensitive, by an estrogen receptor α (EsRα)-dependent mechanism. An inositol 1,4,5-triphosphate (IP3) receptor inhibitor prevented the induction of priming by ryanodine. For IP3induced priming, females were also more sensitive. IP3-induced priming was prevented by pretreatment with inhibitors of the sarcoendoplasmic reticulum calcium ATPase and ryanodine receptor. Antisense to EsRα prevented the induction of priming by low-dose IP3in females. The induction of priming by an EsRα agonist was ryanodine receptor-dependent and prevented by the IP3antagonist. Thus, an EsRα-dependent bidirectional interaction between endoplasmic reticulum IP3and ryanodine receptor-mediated calcium signaling is present in the induction of hyperalgesic priming, in females. In cultured male DRG neurons, IP3(100 μm) potentiated depolarization-induced transients produced by extracellular application of high-potassium solution (20 mm, K20), in nociceptors incubated with β-estradiol. This potentiation of depolarization-induced calcium transients was blocked by the IP3antagonist, and not observed in the absence of IP3IP3potentiation was also blocked by ryanodine receptor antagonist. The application of ryanodine (2 nm), instead of IP3, also potentiated K20-induced calcium transients in the presence of β-estradiol, in an IP3receptor-dependent manner. Our results point to an EsRα-dependent, reciprocal interaction between IP3and ryanodine receptors that contributes to sex differences in hyperalgesic priming.SIGNIFICANCE STATEMENTThe present study demonstrates a mechanism that plays a role in the marked sexual dimorphism observed in a model of the transition to chronic pain, hyperalgesic priming. This mechanism involves a reciprocal interaction between the endoplasmic reticulum receptors, IP3and ryanodine, in the induction of priming, regulated by estrogen receptor α in the nociceptor of female rats. The presence of this signaling pathway modulating the susceptibility of nociceptors to develop plasticity may contribute to our understanding of sex differences observed clinically in chronic pain syndromes.
authors.affiliation: Departments of Medicine and Oral Surgery, and Division of Neuroscience, University of California, San Francisco, San Francisco, California 94143.
authors.forename: Eugen V
authors.identifier: 0000-0003-0221-2237
authors.initials: EV
authors.lastname: Khomula
authors.affiliation: Departments of Medicine and Oral Surgery, and Division of Neuroscience, University of California, San Francisco, San Francisco, California 94143.
authors.forename: Luiz F
authors.initials: LF
authors.lastname: Ferrari
authors.affiliation: Departments of Medicine and Oral Surgery, and Division of Neuroscience, University of California, San Francisco, San Francisco, California 94143.
authors.forename: Dionéia
authors.identifier: 0000-0001-8379-2901
authors.initials: D
authors.lastname: Araldi
authors.affiliation: Departments of Medicine and Oral Surgery, and Division of Neuroscience, University of California, San Francisco, San Francisco, California 94143 Jon.Levine@ucsf.edu.
authors.forename: Jon D
authors.identifier: 0000-0003-0681-5545
authors.initials: JD
authors.lastname: Levine
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D015232:Dinoprostone / Q000009:adverse effects; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005727:Ganglia, Spinal / Q000166:cytology; D006930:Hyperalgesia / Q000139:chemically induced / Q000378:metabolism*; D015544:Inositol 1,4,5-Trisphosphate / Q000494:pharmacology; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000037:antagonists & inhibitors / Q000378:metabolism*; D047028:Macrocyclic Compounds / Q000494:pharmacology; D008297:Male; D020319:Oligodeoxyribonucleotides, Antisense / Q000494:pharmacology; D010080:Oxazoles / Q000494:pharmacology; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012433:Ryanodine / Q000009:adverse effects; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism*; D011984:Sensory Receptor Cells / Q000187:drug effects; D012727:Sex Characteristics; D019284:Thapsigargin / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D053496:Inositol 1,4,5-Trisphosphate Receptors; D047028:Macrocyclic Compounds; D020319:Oligodeoxyribonucleotides, Antisense; D010080:Oxazoles; D019837:Ryanodine Receptor Calcium Release Channel; C511704:xestospongin C; D012433:Ryanodine; D019284:Thapsigargin; D015544:Inositol 1,4,5-Trisphosphate; D015232:Dinoprostone
keywords: IP3 receptor; endoplasmic reticulum; hyperalgesia; hyperalgesic priming; nociceptor; ryanodine receptor