Spinal leptin contributes to the development of morphine antinociceptive tolerance by activating the STAT3-NMDA receptor pathway in rats

  • Authors:
    • Fen Hu
    • Yu Cui
    • Ruixian Guo
    • Jingfu Chen
    • Runming Guo
    • Ning Shen
    • Xiaoxiao Hua
    • Liqiu Mo
    • Jianqiang Feng
  • View Affiliations

  • Published online on: May 20, 2014     https://doi.org/10.3892/mmr.2014.2250
  • Pages: 923-930
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Abstract

Leptin, an adipokine synthesized mainly by non‑neuronal tissues, has been reported to contribute to the pathogenesis of neuropathic pain. It has been hypothesized that morphine tolerance and neuropathic pain share some common pathological mechanisms. The present study was designed to examine whether spinal leptin is implicated in the development of morphine antinociceptive tolerance, and whether spinal leptin induces the activation of signal transducer and activator of transcription 3 (STAT3) signaling pathway and the NR1 subunit of N‑methyl‑D‑aspartate (NMDA) receptor, in morphine antinociceptive tolerance in rats. The results demonstrated that intrathecal (i.t.) administration of a leptin antagonist (LA) prevented the development of morphine antinociceptive tolerance in rats. Further studies revealed that the levels of the spinal leptin and the leptin receptor (Ob‑R) were time‑dependently increased following chronic morphine treatment. Mechanistic examination indicated that chronic morphine triggered activation of the STAT3 pathway and an increase in the expression of the NR1 subunit of the NMDA receptor, which was ameliorated by i.t. administration of AG490 [a Janus kinase (JAK)‑STAT inhibitor]. The increased activation of STAT3 and the NR1 subunit was markedly attenuated by i.t. treatment with LA. In addition, the spinal administration of AG490 or MK‑801 (a non‑competitive NMDA receptor inhibitor) blocked the development of morphine antinociceptive tolerance. Taken together, these results have demonstrated, for the first time, to the best of our knowledge, that spinal leptin contributes to the development of morphine antinociceptive tolerance by activating the spinal STAT3‑NMDA receptor pathway.
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August-2014
Volume 10 Issue 2

Print ISSN: 1791-2997
Online ISSN:1791-3004

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Spandidos Publications style
Hu F, Cui Y, Guo R, Chen J, Guo R, Shen N, Hua X, Mo L and Feng J: Spinal leptin contributes to the development of morphine antinociceptive tolerance by activating the STAT3-NMDA receptor pathway in rats. Mol Med Rep 10: 923-930, 2014
APA
Hu, F., Cui, Y., Guo, R., Chen, J., Guo, R., Shen, N. ... Feng, J. (2014). Spinal leptin contributes to the development of morphine antinociceptive tolerance by activating the STAT3-NMDA receptor pathway in rats. Molecular Medicine Reports, 10, 923-930. https://doi.org/10.3892/mmr.2014.2250
MLA
Hu, F., Cui, Y., Guo, R., Chen, J., Guo, R., Shen, N., Hua, X., Mo, L., Feng, J."Spinal leptin contributes to the development of morphine antinociceptive tolerance by activating the STAT3-NMDA receptor pathway in rats". Molecular Medicine Reports 10.2 (2014): 923-930.
Chicago
Hu, F., Cui, Y., Guo, R., Chen, J., Guo, R., Shen, N., Hua, X., Mo, L., Feng, J."Spinal leptin contributes to the development of morphine antinociceptive tolerance by activating the STAT3-NMDA receptor pathway in rats". Molecular Medicine Reports 10, no. 2 (2014): 923-930. https://doi.org/10.3892/mmr.2014.2250