Long Non-Coding RNA and mRNA Profiles in the Spinal Cord of Rats with Resiniferatoxin-Induced Neuropathic Pain.

Purpose: The ultrapotent transient receptor potential vanilloid 1 (TRPV1) agonist resiniferatoxin (RTX) induces small-fiber sensory neuropathy, which has been widely used model of postherpetic neuralgia to study mechanisms of neuropathic pain and new analgesics. The long non-coding RNA (lncRNA) and mRNA expression profiles in spinal dorsal horn tissues of rats six weeks after RTX injection to identify new RNAs related to neuropathic pain. Methods: Microarray technology was applied to determine lncRNA expressions in spinal dorsal horn samples of adult rats 6 weeks after treatment with RTX or vehicle. The lncNA/mRNA co-expression network was constructed, and differential expression patterns of lncRNA and mRNA in RTX-treated rats were identified. Differential expressions of lncRNAs and mRNAs between RTX-treated samples and control samples were examined by RT-qPCR. Results: Microarray analyses showed that 745 mRNA and 139 lncRNAs were upregulated, whereas 590 mRNA and 140 lncRNAs were downregulated in spinal dorsal horn tissues after RTX exposure. TargetScan was used to predict mRNA targets for these lncRNAs, which showed that the transcripts with multiple predicted target sites were related to neurologically important pathways. In addition, differential expressions of lncRNA (ENSRNOG00000022535, ENSRNOG00000042027, NR_027478, NR_030675) and Apobec3b mRNA in spinal cord tissue samples were validated, which confirmed the microarray data. The association between NR_030675 and Apobec3b levels was confirmed, which may be related to neuropathic pain. Conclusion: Our study reveals lncRNA and mRNA of molecule targets that are enriched in the spinal cord dorsal horn and provides new information for further investigation on the mechanisms and therapeutics of neuropathic pain.

[Stimulating Frequency-dependent Analgesic Effect of Electroacupuncture via Down-regulating Expression of VEGF in Dorsal Horns of Lumbar Spinal Cord in Post Herpetic Neuralgia Rats].

OBJECTIVE: To observe the effect of different frequencies of electroacupuncture (EA) stimulation on pain threshold (PT) and expression of vascular endothelial growth factor (VEGF) in dorsal horns (DHs) of the lumbar spinal cord in resiniferatoxin (RTX)-induced post-herpetic neuralgia (PHN) rats, so as to reveal its mechanism in alleviating PHN. METHODS: Male SD rats were randomized into control, model, 2 Hz-EA, 15 Hz-EA, 100 Hz-EA and sham EA groups (n=16 in each). The PHN model was induced by a single intraperitoneal injection of RTX (250 µg/kg), and rats of the control group received intraperitoneal injection of the same dose of vehicle (10% Tween 80, 10% alcohol and 0.9% NaCl). Rats of EA treatment groups received EA stimulation (2 Hz, 15 Hz or 100 Hz, 1 mA) at the left "Huantiao" (GB 30) and "Yanglingquan" (GB 34) for 30 min, once every other day for 35 days, starting from 1 week after RTX injection. For sham control, acupuncture needles were inserted ipsilaterally into GB 30 and GB 34 for 30 min without electrical stimulation or manual needle manipulation. The mechanical allodynia was quantified with Von Frey filaments. The expression of mRNA and protein of VEGF in the DHs of lumbar spinal cord 4-6 segments (sampled under light microscope) was detected by quantitative polymerase chain reaction (qPCR) and Western blot, respectively. RESULTS: A single RTX injection gradually induced tactile allodynia (significant reduction of the mechanical PT) within 3 weeks relevant to the control group (P<0.01). EA applied to GB 30 and GB 34 at 2 Hz and 15 Hz, but not 100 Hz, significantly decreased the tactile allodynia after the treatment (2 Hz from 2 weeks on and 15 Hz from 3 weeks on) in RTX-treated rats (P<0.05). RTX administration increased the mRNA and protein expression of VEGF in the lumbar spinal cord compared with the control group (P<0. 05). Moreover, 2 Hz, but not 15 Hz and 100 Hz EA significantly reduced VEGF mRNA and protein expression(P<0.05). The expression of both VEGF mRNA and protein was negatively correlated with mechanical PT in RTX-induced PHN rats. CONCLUSION: EA at 2 Hz can significantly reduce VEGF expression in the lumbar spinal cord DHs of PHN rats, which is possibly in part related to its effect in alleviating the mechanical allodynia. Our study suggests that 2 Hz EA is the best stimulation frequency for relieving PHN.

[Therapeutic effects of acupoint injection at cervical Jiaji points and effects on ET and CGRP in the patient of ischemic stroke].

OBJECTIVE: To observe effects of point injection at cervical Jiaji points on endothelin (ET) and calcitonin gene related peptide (CGRP) in the patient of ischemic stroke (IS). METHODS: Seventy cases of IS were randomly divided into a treatment group of 35 cases and a control group of 35 cases. The treatment group were treated with acupoint injection at cervical Jiaji points and routine acupuncture, and the control group only with routine acupuncture. Two weeks constituted one course with an interval of one day between courses. After two courses and 4 courses, changes of ET and CGRP were detected, and after 4 courses, their clinical therapeutic effects were evaluated. RESULTS: Acupoint injection at cervical Jiaji points could significantly decrease ET and increase CGRP level; the cured and markedly effective rate was 88.6% in the treatment group and 68.6% in the control group with a significant difference between the two groups (P < 0.05). CONCLUSION: Acupoint injection at cervical Jiaji points has a very good clinical therapeutic effect and can improve ET and CGRP levels in the patient of IS.