Prevention of neuropathic pain in an animal model of spare nerve injury following oral immunization with recombinant adenovirus serotype 5-mediated NR2B gene transfer

Abstract

Spinal N-methyl-D-aspartate receptor 2B subunit (NR2B)-increased expression plays an important role in the facilitation and maintenance of the persistent pain state due to peripheral nerve injury. A vaccination strategy to reduce the expression of brain protein is feasible and may have therapeutic potential for neurological disorders. Thus, we investigated the effect of oral immunization with recombinant adenovirus serotype 5-mediated NR2B gene transfer (rAd5/NR2B) for the modulation of neuropathic pain. After peroral administration of the rAd5/NR2B vaccine, transgene NR2B expression persisted for at least a week and was associated with the induction of high serum titers of NR2B-specific antibodies. Following the occurrence of mechanical allodynia due to peripheral nerve injury, NR2B-specific antibodies could pass the blood-brain barrier, transport and subsequently bind to the spinal NR2B protein. The humoral immunoresponse results in the strong antiallodynia in the spared nerve injury animal model. These data proved the feasibility of oral immunization with rAd5/NR2B for the prevention of neuropathic pain.

NR2B phosphorylation at tyrosine 1472 in spinal dorsal horn contributed to N‐methyl‐D‐aspartate‐induced pain hypersensitivity in mice

“…Spinal administration of NMDAR antagonists attenuates tissue or nerve injury‐induced pain hypersensitivity, suggesting the critical role of NMDARs in central sensitization (Tan et al,2005, 2010; Wang et al,2007; Qu et al,2009; Wu and Zhuo,2009). A large body of evidence has indicated that direct injection of NMDA onto the spinal dorsal horn of intact animals is also able to elicit mechanical allodynia and thermal hyperalgesia (Sato et al,2003; Shimoyama et al,2005).…”

“…Under physiological conditions, non‐NMDA subtype glutamate receptors, including AMPA and kainate receptors (Li et al,1999; Yoshimura and Jessell,1990), have been indicated to mediate the majority of fast excitatory glutamatergic synaptic transmission onto the dorsal horn neurons, whereas the contribution of NMDARs to physiological pain is dispensable because of their voltage‐dependent Mg 2+ blocking property at resting membrane potential (Yoshimura and Jessell,1990). After peripheral tissue or nerve injury, NMDA receptors, especially NR2BR, undergo a long‐lasting increase in their functions and play a critical role in pathological pain (Tan et al,2005; Wu et al,2005; Iwata et al,2007; Wang et al,2007). However, the molecular mechanisms underlying the prolonged NR2BR hyperactivity are not fully understood as yet.…”

PI3K/Akt Pathway: A Potential Therapeutic Target for Chronic Pain

“…An increasing number of studies have demonstrated that many factors can contribute to the development of neuropathic pain, such as inflammation [57], and changes in neurotransmission [58,59]. Neuropathic pain appears in many anomalous situations, including spinal cord injury [60], diabetes, peripheral nerve injury [61,62] and in some inflammatory conditions [24,41,63,64]. A growing body of evidence has shown that activation of the PI3K/Akt pathway in the spinal cord contributes to hyperalgesia in many neuropathic models [46].…”

Neuropathic pain and temporal expression of preprodynorphin, protein kinase C and N-methyl-d-aspartate receptor subunits after spinal cord injury

“…NR1 is essential for NMDAR activity and interaction with NR2A and NR2B subunits confers functional variability. In particular, blocking the activity of NR2B subunit with antagonists [29], vaccination strategies [33] or small interfering RNAs [28] prevents the development of neuropathic pain. Recently, morphine exposure [19] and diabetes [31] have been shown to induce an up-regulation of NMDAR subunits within the spinal dorsal horn, contributing No changes in PKC␥ mRNA levels of expression were detected in the dorsal spinal cord 1 or 14 days after spinal hemisection but a significant increase in PKC␥ transcripts was observed 28 days after the lesion (*p < 0.05 vs. CTL and other time-points).…”