Effects of nanoparticle-encapsulated curcumin on HIV-gp120-associated neuropathic pain induced by the P2X3 receptor in dorsal root ganglia

• Published in: Brain research bulletin Vol. 135; pp. 53 - 61
• Main Authors: Zhao, Shanhong, Yang, Jinpu, Han, Xinyao, Gong, Yingxin, Rao, Shenqiang, Wu, Bing, Yi, Zhihua, Zou, Lifang, Jia, Tianyu, Li, Lin, Yuan, Huilong, Shi, Liran, Zhang, Chunping, Gao, Yun, Li, Guilin, Liu, Shuangmei, Xu, Hong, Liu, Hui, Liang, Shangdong
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.10.2017
• Subjects: Dorsal root ganglia; HIV-gp120-associated neuropathic pain; Nanoparticle-encapsulated curcumin; P2X3 receptor; Dorsal root ganglia; Nanoparticle-encapsulated curcumin; HIV-gp120-associated neuropathic pain; P2X3 receptor
• ISSN: 0361-9230; 1873-2747
• DOI: 10.1016/j.brainresbull.2017.09.011

•Upregulation of DRG P2X3 in HIV gp120-induced neuropathic pain.•Upregulated P2X3 was accompanied with elevated hyperalgesia.•Nano curcumin decreased gp120 upregulated P2X3 currents in DRG neurons.•Nano curcumin decreased gp120-induced hyperalgesia via decreasing P2X3. HIV-1 envelope glycoprotein (Glycoprotein 120, gp120) can directly stimulate primary sensory afferent neurons and cause chronic neuropathic pain. The P2X3 receptor in the dorsal root ganglia (DRG) is associated with the transmission of neuropathic pain. Curcumin isolated from the herb Curcuma rhizome has anti-inflammatory and anti-tumor effects. The water solubility, targeting and bioavailability of curcumin can be improved by nanoparticle encapsulation. In this study, we sought to explore the effects of nanoparticle-encapsulated curcumin (nano curcumin) on HIV-gp120-induced neuropathic pain mediated by the P2X3 receptor in DRG neurons. The results showed that mechanical and thermal hyperalgesia in rats treated with gp120 were increased compared to those in the control group. The expression levels of P2X3 mRNA and protein in rats treated with gp120 were higher than those in the control group. Nano curcumin treatment decreased mechanical hyperalgesia and thermal hyperalgesia and upregulated the expression levels of P2X3 mRNA and protein in rats treated with gp120. Nano curcumin treatment also reduced the ERK1/2 phosphorylation levels in gp120-treated rat DRG. In addition, P2X3 agonist α,β-methylene ATP (α,β-meATP)-induced currents in DRG neurons cultured with gp120 significantly decreased after co-treatment with nano curcumin. Therefore, nano curcumin treatment may inhibit P2X3 activation, decrease the sensitizing DRG primary afferents and relieve mechanical hyperalgesia and thermal hyperalgesia in gp120-treated rats.