Electroacupuncture alleviates postoperative pain through inhibiting neuroinflammation via stimulator of interferon genes/type-1 interferon pathway / 中西医结合学报

OBJECTIVE@#This work explores the impact of electroacupuncture (EA) on acute postoperative pain (APP) and the role of stimulator of interferon genes/type-1 interferon (STING/IFN-1) signaling pathway modulation in the analgesic effect of EA in APP rats.@*METHODS@#The APP rat model was initiated through abdominal surgery and the animals received two 30 min sessions of EA at bilateral ST36 (Zusanli) and SP6 (Sanyinjiao) acupoints. Mechanical, thermal and cold sensitivity tests were performed to measure the pain threshold, and electroencephalograms were recorded in the primary somatosensory cortex to identify the effects of EA treatment on APP. Western blotting and immunofluorescence were used to examine the expression and distribution of proteins in the STING/IFN-1 pathway as well as neuroinflammation. A STING inhibitor (C-176) was administered intrathecally to verify its role in EA.@*RESULTS@#APP rats displayed mechanical and thermal hypersensitivities compared to the control group (P < 0.05). APP significantly reduced the amplitude of θ, α and γ oscillations compared to their baseline values (P < 0.05). Interestingly, expression levels of proteins in the STING/IFN-1 pathway were downregulated after inducing APP (P < 0.05). Further, APP increased pro-inflammatory factors, including interleukin-6, tumor necrosis factor-α and inducible nitric oxide synthase, and downregulated anti-inflammatory factors, including interleukin-10 and arginase-1 (P < 0.05). EA effectively attenuated APP-induced painful hypersensitivities (P < 0.05) and restored the θ, α and γ power in APP rats (P < 0.05). Meanwhile, EA distinctly activated the STING/IFN-1 pathway and mitigated the neuroinflammatory response (P < 0.05). Furthermore, STING/IFN-1 was predominantly expressed in isolectin-B4- or calcitonin-gene-related-peptide-labeled dorsal root ganglion neurons and superficial laminae of the spinal dorsal horn. Inhibition of the STING/IFN-1 pathway by intrathecal injection of C-176 weakened the analgesic and anti-inflammatory effects of EA on APP (P < 0.05).@*CONCLUSION@#EA can generate robust analgesic and anti-inflammatory effects on APP, and these effects may be linked to activating the STING/IFN-1 pathway, suggesting that STING/IFN-1 may be a target for relieving APP. Please cite this article as: Ding YY, Xu F, Wang YF, Han LL, Huang SQ, Zhao S, Ma LL, Zhang TH, Zhao WJ, Chen XD. Electroacupuncture alleviates postoperative pain through inhibiting neuroinflammation via stimulator of interferon genes/type-1 interferon pathway. J Integr Med. 2023; 21(5): 496-508.

Inhibition of sodium current by carbamazepine in dorsal root ganglion neurons in vitro.

Carbamazepine (CBZ), one of the most commonly prescribed antiepileptic drug, is proposed to inhibit Na+ channel. In this study, we have investigated the effects of CBZ on Na+ current, evoked in cultured dorsal root ganglion (DRG) neurons from neonatal rats using whole cell patch clamp technique. In small DRG neurons (20–25 μm), Na+ current was obtained by blocking K+ and Ca2+ currents with appropriate ion replacement and channel blockers. Separation of the Na+ current components was achieved on the basis of response to the conditioning voltage. The CBZ depressed Na+ current in a dose-dependent manner. The maximal Na+ current was depressed at 300 μM of CBZ, where 94±5.1% of depression was observed. The depression of normalized current amplitude was found to be 72±13.2%, 84±10%, 85±7.1% and 95±5.2% at 10, 30, 100 and 300 μM of CBZ concentrations, respectively, at –20 mV test pulse, when compared with control. The depression of current amplitude was observed as 48±12.3%, 42±15.2%, 71±17.7% and 90±5.8% at 10, 30, 100 and 300 μM of CBZ concentration, respectively, at 0 mV voltage pulse. The depression of Na+ currents was found to be dose-dependant at –20 and –10 mV but not at 0 mV. It is concluded that the depression of Na+ currents by CBZ may be responsible for inhibiting the neurotransmitter release.

Ultrastructural description of rabies virus infection in cultured sensory neurons

Primary cultures were made from adult mouse spinal ganglia for depicting an ultrastructural description of rabies virus (RABV) infection in adult mouse sensory neuron cultures; they were infected with rabies virus for 24, 36, and 48 h. The monolayers were processed for transmission electron microscopy and immunochemistry studies at the end of each period. As previously reported, sensory neurons showed great susceptibility to infection by RABV; however, in none of the periods evaluated were assembled virions observed in the cytoplasm or seen to be associated with the cytoplasmic membrane. Instead, fibril matrices of aggregated ribonucleoprotein were detected in the cytoplasm. When infected culture lysate were inoculated into normal animals via intra-cerebral route it was observed that these animals developed clinical symptoms characteristic of infection and transmission electron microscopy revealed assembled virions in the cerebral cortex and other areas of the brain. Sensory neurons infected in vitro by RABV produced a large amount of unassembled viral ribonucleoprotein. However, this intracellular material was able to produce infection and virions on being intra-cerebrally inoculated. It can thus be suggested that the lack of intracellular assembly in sensory neurons forms part of an efficient dissemination strategy.

Effects of Intrathecally Administerd NaV1.8 Antisense Oligonucleotide on the Expression of Sodium Channel mRNA in Dorsal Root Ganglion / 华中科技大学学报（医学）（英德文版）

Neuropathic pain has been hypothesized to be the result of aberrant expression and function of sodium channels at the site of injury. To investigate the effects of NaV1.8 antisense oligonucleotide on the expression of sodium channel mRNA in dorsal root ganglion (DRG) neurons in chronic neuropathic pain. 24 Sprague-Dawley rats weighing 200-260 g were anesthetized with the in of sciatic nerve trunk by 4-0 chromic gut. The mechanical and thermal pain threshold were measured before operation and 1, 3, 5, 7, 9, 11, 13 days after operation. A PE-10 catheter was implanted in subarachnoid space at lumbar region. On the 7th postoperative day the animals were randomly divided into 4 groups. The drugs were injected intrathecally twice a day for 5 consecutive days in group 2-4. The animals were decapitated 14 days after the surgery. The L4-L6 DRG of the operated side was removed and crushed, and total RNA was extracted with Trizol reagent. The contralateral side was used as control. The change of NaV1.8 sodium channel transcripts was determined by RT-PCR. Pain threshold was significantly lowered after CCI as compared with that in control group and was elevated 3 days after antisense oligonucleotide injection. Sensory neuron specific TTX-R sodium channel NaV1.8 transcript was down-regulated after antisense oligonucleotide injection at the dosage of 45 μg as compared with that in CCI group (P＜0.01), and it was even greater at the dosage of 90 μg. The intrathecally injected NaV1.8 antisense oligonucleotide can reduce the mechanical allodynia and thermal hyperalgesia partially by downregulating the SNS transcript expression.

The Localization of Efferent and Afferent Neurons Innervating the Rat Thymus Using the Neural Tracers / 대한해부학회지

The localizations of efferent and afferent neurons were observed following injection of neural tracers, cholera toxin B subunit (CTB) and wheat germ agglutinin-horseradish peroxidase (WGA-HRP) into the rat thymus with ages. Thirty Sprague-Dawley rats were examined at 3 weeks, 5~6 and 20 months of age. After survival times of 48~96 hours following injection of neural tracers, the rats were perfused and their brain, spinal cord, sympathetic ganglia, dorsal root ganglia and vagal ganglia were frozen sectioned (40 mm). These sections were stained by CTB immunohistochemical and HRP histochemical staining methods, and observed with polarized dark and light microscope. The results were as follows: 1. WGA-HRP and CTB labeled parasympathetic neurons were bilaterally seen in the nucleus ambiguus and medullary reticular formation of medulla with all ages. 2. WGA-HRP labeled sympathetic neurons were bilaterally labeled in superior cervical ganglia, middle cervical ganglia, stellate ganglia and T4-8 sympathetic chain ganglia. The number of labeled sympathetic neurons was increased in the thymus at 20 months of age. According to the aging, sympathetic neuronal processes were more developed, and the nerve fibers were coarse and more branched. 3. WGA-HRP labeled sensory neurons were bilaterally observed within the vagal and C1-6 dorsal root ganglia. The number of labeled sensory neurons was decreased in the thymus at 20 months of age.

Localization of Sensory Neurons Innervating the Rat Intestine Using the Cholera Toxin B Subunit(CTB) and Wheat Germ Agglutinin-Horseradish Peroxidase(WGA-HRP) / 영남의대학술지

The local arrangement of sensory nerve cell bodies and nerve fibers in the brain stem, spinal ganglia and nodose ganglia were observed following injection of cholera toxin B subunit(CTB) and wheat germ agglutinin-horseradish peroxidase(WGA-HRP) into the rat intestine. The tracers were injected in the stomach(anterior and posterior portion), duodenum, jejunum, ileum, cecum, ascending colon or descending colon. After survival times of 48-96 hours, the rats were perfused and their brain, spinal and nodose ganglia were frozen sectioned(40microM). These sectiones were stained by CTB immunohistochemical and HRP histochemical staining methods and observed by dark and light microscopy. The results were as follows: 1. WGA-HRP labeled afferent terminal fields in the brain stem were seen in the stomach and cecum, and CTB labeled afferent terminal fields in the brain stem were seen in all parts of the intestine. 2. Afferent terminal fields innervating the intestine were heavily labeled bilaterally gelalinous part of nucleus of tractus solitarius(gelNTS), dorsomedial part of gelNTS, commissural part of NTS(comNTS), medial part of NTS(medNTS), wall of the fourth ventricle, ventral border of area postrema and comNTS in midline dorsal to the central canal. 3. WGA-HRP labeled sensory neurons were observed bilaterally within the spinal ganglia, and labeled sensory neurons innervating the stomach were observed in spinal ganglia T2-L1 and the most numerous in spinal ganglia T8-9. 4. Labeled sensory neurons innervating the duodenum were observed in spinal ganglia T6-L2 and labeled cell number were fewer than the other parts of the intestines. 5. Labeled sensory neurons innervating the jejunum were observed in spinal ganglia T6-L2 and the most numerous area in the spinal ganglia were T12 in left and T13 in right. 6. Labeled sensory neurons innervating the ileum were observed in spinal ganglia T6-L2 and the most numerous area in the spinal ganglia were T11 in left and L1 in right. 7. Labeled sensory neurons innervating the cecum were observed in spinal ganglia T7-L2 and the most numerous area in the spinal ganglia were T11 in left and T11-12 in right. 8. Labeled sensory neurons innervating the ascending colon were observed in spinal ganglia T7-L2 in left, and T9-L4 in right. The most numerous area in the spinal ganglia were T9 in left and T11 in right. 9. Labeled sensory neurons innervating the descending colon were observed in spinal ganglia T9-L2 in left, and T6-L2 in right. The most numerous area in the spinal ganglia were T13 in left and L1 in right. 10. WGA-HRP labeled sensory neurons were observed bilaterally within the nodose ganglia, and the most numerous labeled sensory neurons innervating the abdominal organs were observed in the stomach. 11. The number of labeled sensory neurons within the nodose ganglia innervating small and large intestines were fewer than that of labeled sensory neurons innervating stomach These results indicated that area of sensory neurons innervated all parts of intestines were bilaterally gelatinous part of nucleus tractus solitarius(gelNTS), dorsomedial part of gelNTS, commissural part of NTS(comNTS), medial part of NTS, wall of the fourth ventricle, ventral border of area postrema and com NTS in midline dorsal to the central canal within brain stem, spinal ganglia T2-L4, and nodose ganglia. Labeled sensory neurons innervating the intestines except the stomach were observed in spinal ganglia T6-L4. The most labeled sensory neurons from the small intestine to large intestine came from middle thoracic spinal ganglia to upper lumbar spinal ganglia.