Corticotropin-releasing factor mediates bone cancer induced pain through neuronal activation in rat spinal cord

Abstract Background The underlying mechanism of chronic pain involves the plasticity in synaptic receptors and neurotransmitters. This study aimed to investigate potential roles of neuroligins (NLs) within the spinal dorsal horn of rats in a newly established bone cancer pain (BCP) model. Methods Using our rat BCP model, we assessed pain hypersensitivity over time. Quantitative real-time polymerase chain reaction and Western blot analysis were performed to investigate NL expression, and NLs were overexpressed in the rat spinal cord using lentiviral vectors. Immunofluorescence staining and whole-cell patch-clamp recordings were deployed to investigate the role of NLs in the development of BCP. Results We observed reduced expression levels of NL1 and NL2, but not NL3, within the rat spinal cord, which were found to be associated with and essential for the development of BCP in our model. Accordingly, NL1 or NL2 overexpression in the spinal cord alleviated mechanical hypersensitivity of rats. Electrophysiological experiments indicated that NL1 and NL2 are involved in BCP via regulating γ-aminobutyric acid-ergic interneuronal synapses and the activity of glutamatergic interneuronal synapses, respectively. Conclusions Our observations unravel the role of NLs in cancer-related chronic pain and further suggest that inhibitory mechanisms are central features of BCP in the spinal dorsal horn. These results provide a new perspective and basis for subsequent studies elucidating the onset and progression of BCP.

Download Full-text

Functional and anatomical characterization of corticotropin-releasing factor receptor subtypes of the rat spinal cord involved in somatic pain relief

10.21203/rs.3.rs-290650/v1 ◽

2021 ◽

Author(s):

Shaaban Mousa ◽

Mohammed Shaqura ◽

Baled Khalefa ◽

Li Li ◽

Mohammed Al-madol ◽

...

Keyword(s):

Spinal Cord ◽

Western Blot ◽

Opioid Receptor ◽

Radioligand Binding ◽

Corticotropin Releasing Factor ◽

Receptor Subtypes ◽

Inhibitory Interneurons ◽

Rat Spinal Cord ◽

Somatic Pain ◽

Antinociceptive Effects

Abstract Corticotropin-releasing factor (CRF) orchestrates our body’s response to stressful stimuli. Pain is often stressful and counterbalanced by activation of CRF receptors along the nociceptive pathway, although the involvement of the CRF receptors of subtypes 1 and/or 2 (CRF-R1 and CRF-R2, respectively) in CRF-induced analgesia remains controversial. This study aimed to examine CRF-R1 and CRF-R2 expression within spinal cord of rats with Freund’s complete adjuvant-induced hindpaw inflammation using reverse transcriptase polymerase chain reaction, Western blot, radioligand binding, and immunofluorescence confocal analysis, Western blot, immunohistochemistry, and radioligand binding. Moreover, paw pressure algesiometry examined antinociceptive effects of intrathecal (i.t.) CRF and their possible antagonism through CRF-R1 and/or CRF-R2 selective antagonists as well as opioid receptor antagonist naloxone. Our results demonstrated mainly CRF-R2 mRNA, protein, binding sites and immunoreactivity in dorsal horn of rat spinal cord. In parallel, i.t. CRF as well as CRF-R2 agonists elicited potent antinociceptive effects which are dose-dependent and antagonized exclusively by i.t. CRF-R2 (K41498), but not CRF-R1 (NBI35965) antagonist. Moreover, i.t. CRF elicited inhibition of somatic pain that was dose-dependently reversed by the opioid antagonist naloxone. Consistently, double immunofluorescence confocal microscopy showed CRF-R2 on enkephalin (ENK) containing inhibitory interneurons in close opposition of incoming, mu-opioid receptor-immunoreactive nociceptive neurons but not on pre- nor on postsynaptic sensory neurons of the spinal cord. Taken together, these findings suggest that i.t. CRF or CRF-R2 agonist inhibits inflammatory somatic pain which occurs most predominantly through CRF-R2 receptors located on spinal enkephalinergic inhibitory interneurons resulting in endogenous opioid-mediated pain inhibition.

Download Full-text

Oxytocin ameliorates bone cancer pain by suppressing toll-like receptor 4 and proinflammatory cytokines in rat spinal cord

Journal of Neurogenetics ◽

10.1080/01677063.2019.1711077 ◽

2020 ◽

Vol 34 (2) ◽

pp. 216-222

Author(s):

Xiaping Mou ◽

Ji Fang ◽

An Yang ◽

Gang Du

Keyword(s):

Spinal Cord ◽

Cancer Pain ◽

Proinflammatory Cytokines ◽

Bone Cancer ◽

Bone Cancer Pain ◽

Toll Like Receptor ◽

Rat Spinal Cord ◽

Toll Like Receptor 4

Download Full-text

Capsaicin Depletes Corticotropin-Releasing Factor-Like Immunoreactive Neurons in the Rat Spinal Cord and Medulla oblongata

Neuroendocrinology ◽

10.1159/000123942 ◽

1984 ◽

Vol 38 (6) ◽

pp. 514-517 ◽

Cited By ~ 46

Author(s):

Gerhard Skofitsch ◽

Geoffrey S. Hamill ◽

David M. Jacobowitz

Keyword(s):

Spinal Cord ◽

Medulla Oblongata ◽

Corticotropin Releasing Factor ◽

Rat Spinal Cord

Download Full-text

Immunocytochemical localization of corticotropin releasing factor (CRF) in the rat spinal cord

Brain Research ◽

10.1016/0006-8993(83)91001-6 ◽

1983 ◽

Vol 275 (2) ◽

pp. 373-377 ◽

Cited By ~ 102

Author(s):

I. Merchenthaler ◽

M.A. Hynes ◽

S. Vigh ◽

A.V. Shally ◽

P. Petrusz

Keyword(s):

Spinal Cord ◽

Corticotropin Releasing Factor ◽

Immunocytochemical Localization ◽

Rat Spinal Cord

Download Full-text

Effects of corticotropin-releasing factor on plasticity of optically recorded neuronal activity in the substantia gelatinosa of rat spinal cord slices

Pain ◽

10.1016/j.pain.2003.08.004 ◽

2003 ◽

Vol 106 (1) ◽

pp. 197-207 ◽

Cited By ~ 12

Author(s):

Hiroshi Ikeda ◽

Kei Kusudo ◽

Pan-Dong Ryu ◽

Kazuyuki Murase

Keyword(s):

Spinal Cord ◽

Neuronal Activity ◽

Corticotropin Releasing Factor ◽

Substantia Gelatinosa ◽

Rat Spinal Cord

Download Full-text

Functional and anatomical characterization of corticotropin-releasing factor receptor subtypes of the rat spinal cord involved in somatic pain relief

10.21203/rs.3.rs-268281/v1 ◽

2021 ◽

Author(s):

Shaaban A. Mousa ◽

Mohammed Shaqura ◽

Baled Khalefa ◽

Li Li ◽

Mohammed Al-madol ◽

...

Keyword(s):

Spinal Cord ◽

Western Blot ◽

Opioid Receptor ◽

Radioligand Binding ◽

Corticotropin Releasing Factor ◽

Receptor Subtypes ◽

Inhibitory Interneurons ◽

Rat Spinal Cord ◽

Somatic Pain ◽

Antinociceptive Effects

Abstract Background: Corticotropin-releasing factor (CRF) orchestrates our body’s response to stressful stimuli. Pain is often stressful and counterbalanced by activation of CRF receptors along the nociceptive pathway, although the involvement of the CRF receptors of subtypes 1 and/or 2 (CRF-R1 and CRF-R2, respectively) in CRF-induced analgesia remains controversial.Methods: This study aimed to examine CRF-R1 and CRF-R2 expression within spinal cord of rats with Freund’s complete adjuvant-induced hindpaw inflammation using reverse transcriptase polymerase chain reaction, Western blot, radioligand binding, and immunofluorescence confocal analysis, Western blot, immunohistochemistry, and radioligand binding. Moreover, paw pressure algesiometry examined antinociceptive effects of intrathecal (i.t.) CRF and their possible antagonism through CRF-R1 and/or CRF-R2 selective antagonists as well as opioid receptor antagonist naloxone.Results: Our results demonstrated mainly CRF-R2 mRNA, protein, binding sites and immunoreactivity in dorsal horn of rat spinal cord. In parallel, i.t. low, systemically inactive doses of CRF as well as CRF-R2 agonists elicited potent antinociceptive effects which are dose-dependent and antagonized exclusively by i.t. CRF-R2 (K41498), but not CRF-R1 (NBI35965) antagonist. Moreover, i.t. CRF elicited inhibition of somatic pain that was dose-dependently reversed by the opioid antagonist naloxone. Consistently, double immunofluorescence confocal microscopy showed CRF-R2 on enkephalin (ENK) containing inhibitory interneurons in close opposition of incoming, mu-opioid receptor-immunoreactive nociceptive neurons but not on pre- nor on postsynaptic sensory neurons of the spinal cord.Conclusion: Taken together, these findings suggest that i.t. CRF or CRF-R2 agonist inhibits inflammatory somatic pain which occurs most predominantly through CRF-R2 receptors located on spinal enkephalinergic inhibitory interneurons resulting in endogenous opioid-mediated pain inhibition.

Download Full-text