scholarly journals Pregabalin alleviates postherpetic neuralgia by downregulating spinal TRPV1 channel protein

2021 ◽  
Vol 20 (11) ◽  
pp. 2287-2292
Author(s):  
Zhenping Xiao ◽  
Mengjun Liao ◽  
Yunwu He ◽  
Yonglin Li ◽  
Wuzhou Yang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Dorsal Horn ◽  
Postherpetic Neuralgia ◽  
New Drugs ◽  
Spinal Cord Tissue ◽  
Sprague Dawley ◽  
Trpv1 Channel ◽  
Channel Protein ◽  
Tnf Α ◽  
Prefrontal Lobe

Purpose: To determine the mechanism involved in pregabalin-induced alleviation of postherpetic neuralgia in a rat model.Methods: Ninety-sixty healthy Sprague-Dawley (SD) rats were assigned to sham, model andpregabalin groups (32 rats per group). A model of postherpetic neuralgia (PN) was established. The expressions of IL-1β and TNF-α in spinal cord tissue were determined 7 days after administration of treatments. The proportions of fluorescence areas in astrocytes in the dorsal horn, prefrontal lobe and hippocampus, and level of spinal cord TRPV1 channel protein in each group were evaluated.Results: Relative to model rats, IL-1β and TNF-α in spinal cord of pregabalin rats were significantly reduced (p < 0.05). The areas of fluorescence in astrocytes in dorsal horn of spinal cord, prefrontal lobe and hippocampus of model group were significantly increased, relative to sham, but were decreased in rats in pregabalin group (p < 0.05).Conclusion: Pregabalin significantly alleviates postherpetic neuralgia via mechanisms which may be related to the inflammatory response of spinal dorsal horn and downregulation of TRPV1 channel protein expression. This finding may be useful in developing new drugs for alleviating postherpetic neuralgia.

scholarly journals Characterization of ultrasound-mediated delivery of trastuzumab to normal and pathologic spinal cord tissue

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Paige Smith ◽  
Natalia Ogrodnik ◽  
Janani Satkunarajah ◽  
Meaghan A. O’Reilly
Keyword(s):  
Drug Delivery ◽  
Spinal Cord ◽  
Focused Ultrasound ◽  
Healthy Tissue ◽  
Spinal Cord Tissue ◽  
Sprague Dawley ◽  
Intense Staining ◽  
Her2 Breast Cancer ◽  
Sprague Dawley Rats ◽  
Blood Spinal Cord Barrier

AbstractExtensive studies on focused ultrasound (FUS)-mediated drug delivery through the blood–brain barrier have been published, yet little work has been published on FUS-mediated drug delivery through the blood-spinal cord barrier (BSCB). This work aims to quantify the delivery of the monoclonal antibody trastuzumab to rat spinal cord tissue and characterize its distribution within a model of leptomeningeal metastases. 10 healthy Sprague–Dawley rats were treated with FUS + trastuzumab and sacrificed at 2-h or 24-h post-FUS. A human IgG ELISA (Abcam) was used to measure trastuzumab concentration and a 12 ± fivefold increase was seen in treated tissue over control tissue at 2 h versus no increase at 24 h. Three athymic nude rats were inoculated with MDA-MB-231-H2N HER2 + breast cancer cells between the meninges in the thoracic region of the spinal cord and treated with FUS + trastuzumab. Immunohistochemistry was performed to visualize trastuzumab delivery, and semi-quantitative analysis revealed similar or more intense staining in tumor tissue compared to healthy tissue suggesting a comparable or greater concentration of trastuzumab was achieved. FUS can increase the permeability of the BSCB, improving drug delivery to specifically targeted regions of healthy and pathologic tissue in the spinal cord. The achieved concentrations within the healthy tissue are comparable to those reported in the brain.

Elimination of rat spinal neurons expressing neurokinin 1 receptors reduces bladder overactivity and spinal c-fos expression induced by bladder irritation

2005 ◽  
Vol 288 (3) ◽  
pp. F466-F473 ◽  
Author(s):  
Satoshi Seki ◽  
Kristin A. Erickson ◽  
Masako Seki ◽  
Osamu Nishizawa ◽  
Yasuhiko Igawa ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Dorsal Horn ◽  
Intrathecal Administration ◽  
Superficial Layer ◽  
Sprague Dawley ◽  
Intrathecal Catheter ◽  
Micturition Reflex ◽  
Nociceptive Responses ◽  
Fos Expression ◽  
Neurokinin 1

Substance P (SP) binding to neurokinin 1 receptors (NK1R) in the spinal cord reportedly plays an important role in the micturition reflex as well as in nociceptive responses. We therefore investigated the effect of ablation of NK1R-expressing neurons in the spinal cord using saporin, a ribosome-inactivating protein, conjugated with [Sar9, Met (O2)11]SP, a specific ligand of NK1R (SSP-saporin), on the micturition reflex in rats. In female Sprague-Dawley rats, SSP-saporin (1.0 or 1.5 μM) or saporin (1.5 μM) only was injected through an intrathecal catheter implanted at the L6-S1 level of the spinal cord. Three weeks after intrathecal administration of SSP-saporin, NK1R immunoreactivity in lamina I of the spinal cord was significantly reduced, but cystometric parameters in awake rats were not altered. Instillation of capsaicin (15 μM) into the bladder of normal rats induced bladder overactivity. This response to capsaicin was significantly suppressed in SSP-saporin-treated animals. SSP-saporin treatment also decreased c- fos expression in the dorsal horn of the spinal cord induced by instillation of capsaicin into the bladder. These data indicate that NK1R-expressing neurons in the superficial layer of the dorsal horn play an important role in transmission of nociceptive afferent information from the bladder to induce bladder overactivity and spinal c- fos expression elicited by bladder irritation. Toxin-induced damage of NK1R-expressing neurons in the lumbosacral spinal cord may provide an effective modality for treating overactivity and/or nociceptive responses in the bladder without affecting normal micturition.

scholarly journals Dynamic effects of TNF-α on synaptic transmission in mice over time following sciatic nerve chronic constriction injury

2013 ◽  
Vol 110 (7) ◽  
pp. 1663-1671 ◽  
Author(s):  
Hongmei Zhang ◽  
Haijun Zhang ◽  
Patrick M. Dougherty
Keyword(s):  
Spinal Cord ◽  
Neuropathic Pain ◽  
Sciatic Nerve ◽  
Synaptic Transmission ◽  
Dorsal Horn ◽  
Nerve Injury ◽  
Chronic Constriction Injury ◽  
Synaptic Signaling ◽  
Tnf Α ◽  
Over Time

Nerve injury-induced central sensitization can manifest as an increase in excitatory synaptic transmission and/or as a decrease in inhibitory synaptic transmission in spinal dorsal horn neurons. Cytokines such as tumor necrosis factor-α (TNF-α) are induced in the spinal cord under various injury conditions and contribute to neuropathic pain. In this study we examined the effect of TNF-α in modulating excitatory and inhibitory synaptic input to spinal substantia gelatinosa (SG) neurons over time in mice following chronic constriction injury (CCI) of the sciatic nerve. Whole cell patch-clamp studies from SG neurons showed that TNF-α enhanced overall excitability of the spinal cord early in time following nerve injury 3 days after CCI compared with that in sham control mice. In contrast, the effects of TNF were blunted 14 days after CCI in nerve-injured mice compared with sham surgery mice. Immunohistochemical staining showed that the expression of TNF-α receptor 1 (TNFR1) was increased at 3 days but decreased at 14 days following CCI in the ipsilateral vs. the contralateral spinal cord dorsal horn. These results suggest that TNF-α acting at TNFR1 is important in the development of neuropathic pain by facilitating excitatory synaptic signaling in the acute phases after nerve injury but has a reduced effect on spinal neuron signaling in the later phases of nerve injury-induced pain. Failure of the facilatory effects of TNF-α on excitatory synaptic signaling in the dorsal horn to resolve following nerve injury may be an important component in the transition between acute and chronic pain conditions.

Effects of curcumin on acute spinal cord ischemia-reperfusion injury in rabbits

2014 ◽  
Vol 20 (4) ◽  
pp. 464-470 ◽  
Author(s):  
Gokhan Kurt ◽  
Zuhal Yildirim ◽  
Berker Cemil ◽  
Emrah Celtikci ◽  
Gulnur Take Kaplanoglu
Keyword(s):  
Spinal Cord ◽  
Reperfusion Injury ◽  
Sham Group ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Spinal Cord Ischemia ◽  
Histological Evaluation ◽  
Spinal Cord Tissue ◽  
Tnf Α ◽  
Nitrite Nitrate

Object The object of this study was to conduct a prospective, randomized, laboratory investigation of the neuroprotective effects of curcumin functionally, biochemically, and histologically in an experimental acute spinal cord ischemia-reperfusion injury on rabbits. Methods Eighteen rabbits were randomly assigned to 1 of 3 groups: the sham group, the ischemia-reperfusion group, or the curcumin group. Spinal cord ischemia was induced by applying an infrarenal aortic cross-clamp for 30 minutes. At 48 hours after ischemia, neurological function was evaluated with modified Tarlov criteria. Biochemical changes in the spinal cord and plasma were observed by measuring levels of malondialdehyde (MDA), advanced oxidation protein products (AOPP), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), nitrite/nitrate, and tumor necrosis factor-α (TNF-α). Histological changes were examined with H & E staining. Immunohistochemical staining with antibodies against caspase-3 was performed to evaluate cell apoptosis after ischemia. Results In the curcumin group, neurological outcome scores were statistically significantly better compared with the ischemia-reperfusion group. In the ischemia-reperfusion group, MDA, AOPP, and nitrite/nitrate levels were significantly elevated in the spinal cord tissue and the plasma by the induction of ischemia-reperfusion. The curcumin treatment significantly prevented the ischemia-reperfusion–induced elevation of nitrite/nitrate and TNF-α. In addition, the spinal cord tissue and the plasma SOD, GSH, and CAT levels were found to be preserved in the curcumin group and not statistically different from those of the sham group. Histological evaluation of the tissues also demonstrated a decrease in axonal damage, neuronal degeneration, and glial cell infiltration after curcumin administration. Conclusions Although further studies including different dose regimens and time intervals are required, curcumin could attenuate a spinal cord ischemia-reperfusion injury in rabbits via reducing oxidative products and proinflammatory cytokines, as well as increasing activities of antioxidant enzymes and preventing apoptotic cell death.

scholarly journals Genistein Loaded Nanofibers Protect Spinal Cord Tissue Following Experimental Injury in Rats

Biomedicines ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 96 ◽  
Author(s):  
Mohamed Ismail ◽  
Sara Ibrahim ◽  
Azza El-Amir ◽  
Amira EL-Rafei ◽  
Nageh Allam ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Spinal Cord ◽  
Drug Delivery System ◽  
Delivery System ◽  
Therapeutic Drug ◽  
Control Group ◽  
Spinal Cord Tissue ◽  
Injured Spinal Cord ◽  
Tnf Α ◽  
Cord Injury

Innovative drug-delivery systems offer a unique approach to effectively provide therapeutic drug dose over the needed time to achieve better tissue protection and enhanced recovery. The hypothesis of the current study was to test the antioxidant and anti-inflammatory effects of genistein and nanofibers on the spinal cord tissue following experimental spinal cord injury (SCI). Rats were treated post SCI with genistein that is loaded on chitosan/polyvinyl alcohol (CS/PVA) nanofibers as an implantable drug-delivery system. SCI caused marked oxidative damage and inflammation, as is evident by the reduction in the super oxide dismutase (SOD) activity and the level of interleukin-10 (IL-10) in injured spinal cord tissue, as well as the significant increase in the levels of nitric oxide (NO), malondialdehyde (MDA), and tumor necrosis factor-alpha (TNF-α). Treatment of rats post SCI with genistein and CS/PVA nanofibers improved most of the above-mentioned biochemical parameters and shifted them toward the control group values. Genistein induced an increase in the activity of SOD and the level of IL-10, while causing a decrease in NO, MDA, and TNF-α in injured spinal cord tissue. Genistein and CS/PVA nanofibers provide a novel combination for treating inflammatory nervous tissue conditions, especially when combined as an implantable drug-delivery system.

Intravenous Morphine Increases Release of Nitric Oxide From Spinal Cord by an α-Adrenergic and Cholinergic Mechanism

1997 ◽  
Vol 78 (4) ◽  
pp. 2072-2078 ◽  
Author(s):  
Zemin Xu ◽  
Chuanyao Tong ◽  
Hui-Lin Pan ◽  
Sergio E. Cerda ◽  
James C. Eisenach
Keyword(s):  
Nitric Oxide ◽  
Spinal Cord ◽  
Dorsal Horn ◽  
Cervical Spinal Cord ◽  
Intrathecal Injection ◽  
Spinal Cord Tissue ◽  
Cholinergic Mechanism ◽  
Adrenergic Antagonist ◽  
Opioid Administration ◽  
Intravenous Morphine

Xu, Zemin, Chuanyao Tong, Hui-Lin Pan, Sergio E. Cerda, and James C. Eisenach. Intravenous morphine increases release of nitric oxide from spinal cord by an α-adrenergic and cholinergic mechanism. J. Neurophysiol. 78: 2072–2078, 1997. Systemic opioids produce analgesia in part by activating bulbospinal noradrenergic pathways. Spinally released norepinephrine (NE) has been suggested to produce analgesia in part by stimulating α2-adrenoceptors on cholinergic spinal interneurons to release acetylcholine (ACh). We hypothesized that this spinally released ACh would stimulate synthesis of nitric oxide (NO), and that spinally released NO after intravenous (IV) opioid injection thus would depend on a cascade of noradrenergic and cholinergic receptor stimulation. To test these hypotheses, IV morphine was administered to anesthetized sheep, and neurotransmitters in dorsal horn interstitial fluid were measured by microdialysis. IV morphine increased NE and ACh in dorsal horn microdialysates, and these increases were inhibited by IV naloxone or cervical spinal cord transection. IV morphine also increased dorsal horn microdialysate concentrations of nitrite, a stable metabolite of NO. Increases in NE, ACh, and nitrite were antagonized by prior intrathecal injection of the α2-adrenergic antagonist idazoxan, the muscarinic antagonist atropine, or the NO synthase inhibitor N-methyl-l-arginine (NMLA). To examine the concentration-dependent effects of spinal adrenergic stimulation, isolated rat spinal cord tissue was perfused with the α2-adrenergic agonist clonidine. Clonidine increased nitrite in the spinal cord tissue perfusate, an effect blocked by coadministration of idazoxan, atropine, and NMLA. These data support a previously hypothesized cascade of spinally released NE and ACh after systemic opioid administration. These data also suggest that spinally released NO plays a role in the analgesic effects of systemic opioids. In addition, these data imply a positive feedback whereby spinally released nitric oxide increases NE release and that has not previously been described.

scholarly journals LncRNA KCNA2-AS regulates spinal astrocyte activation through STAT3 to affect postherpetic neuralgia

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Cunlong Kong ◽  
Jie Du ◽  
Huilian Bu ◽  
Chen Huang ◽  
Fuxing Xu ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Postherpetic Neuralgia ◽  
Spinal Cord Tissue ◽  
Astrocyte Activation ◽  
Signal Transducers ◽  
Varicella Zoster ◽  
Rna Immunoprecipitation ◽  
Transcription 3 ◽  
Phosphorylated Stat3

Abstract Objectives Postherpetic neuralgia (PHN) is the most common complication of herpes zoster, but the mechanism of PHN is still unclear. Activation of spinal astrocytes is involved in PHN. Our study aims to explore whether lncRNA KCNA2 antisense RNA (KCNA2-AS) regulates spinal astrocytes in PHN through signal transducers and activators of transcription 3 (STAT3). Methods Varicella zoster virus (VZV)-infected CV-1 cells were injected into rats to construct a PHN model. Primary spinal cord astrocytes were activated using S-Nitrosoglutathione (GSNO). Glial fibrillary acidic protein (GFAP; marker of astrocyte activation), phosphorylated STAT3 (pSTAT3), and KCNA2-AS were analyzed by immunofluorescence and RNA fluorescence in situ hybridization. RNA pull-down and RNA immunoprecipitation were used to detect binding of KCNA2-AS to pSTAT3. Results KCNA2-AS was highly expressed in the spinal cord tissue of PHN model rats, and was positively correlated with GFAP expression. GFAP was significantly increased in GSNO-induced cells, but the knockdown of KCNA2-AS reversed this result. Meanwhile, pSTAT3 was significantly increased in GSNO-induced cells, but knockdown of KCNA2-AS reduced pSTAT3 within the nucleus while the total pSTAT3 did not change significantly. pSTAT3 bound to KCNA2-AS and this binding increased with GSNO treatment. Furthermore, knockdown of KCNA2-AS in PHN model rats relieved mechanical allodynia. Conclusion Down-regulation of KCNA2-AS alleviates PHN partly by reducing the translocation of pSTAT3 cytoplasm to the nucleus and then inhibiting the activation of spinal astrocytes.

The thalidomide analgesic effect is associated with differential TNF-α receptor expression in the dorsal horn of the spinal cord as studied in a rat model of neuropathic pain

2012 ◽  
Vol 1450 ◽  
pp. 24-32 ◽  
Author(s):  
Pablo Andrade ◽  
Veerle Visser-Vandewalle ◽  
John S. Del Rosario ◽  
Marc A. Daemen ◽  
Wim A. Buurman ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Neuropathic Pain ◽  
Dorsal Horn ◽  
Rat Model ◽  
Analgesic Effect ◽  
Receptor Expression ◽  
Tnf Α

scholarly journals Mmu-miR-27a-5p Promotes the Polarization of Macrophages to the M2 Phenotype at the Site of Spinal Cord Injury in Mice

2021 ◽  
Author(s):  
Mingkun Yang ◽  
Xiaoqian Dang ◽  
Xu Zhang ◽  
Chuan Liu ◽  
Min He
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Function ◽  
Macrophage Polarization ◽  
Spinal Cord Tissue ◽  
Injured Spinal Cord ◽  
Arginase 1 ◽  
Tnf Α ◽  
Cord Injury ◽  
M2 Phenotype

Abstract BackgroundTo investigate the effect of mmu-miR-27a-5p on macrophage polarization in the injured spinal cord and the recovery of motor function after spinal cord injury (SCI) in mice.MethodsA total of 160 specific-pathogen-free male mice were randomly divided into sham, model, mmu-miR-27a-5p, mmu-miR-27a-5p-negative control (NC) groups, with 40 mice in each group. Hindlimb motor function was assessed using the Basso Mouse scale (BMS) before injury and at 1, 3, 7, and 14 days after surgery. Spinal cord tissue samples were obtained at 1, 3, 7, and 14 days after surgery, and macrophage polarization types were detected by using western blot analysis, immunofluorescence, flow cytometry and RT-qPCR.ResultsThe BMS score in the mmu-miR-27a-5p group was significantly higher than that in the model and mmu-miR-27a-5p-NC groups at 7 and 14 days after SCI (X2=26.45-57.62, P<0.05). No significant changes in the expression of M1 markers IL-1β, TNF-α and M2 markers IL-10, Arginase-1 at each time point in the sham group (P=0.96). The expression of IL-1β and TNF-α was significantly lower, while the expression of IL-10 and Arginase-1 were significantly higher in the mmu-miR-27a-5p group as compared to the model and mmu-miR-27a-5p-NC groups at 7 and 14 days after SCI (P<0.05).ConclusionAdministration of mmu-miR-27a-5p can promote the polarization of macrophages to the M2 phenotype in the injured spinal cord, and improve motor function recovery within 14 days after SCI in mice.

scholarly journals Biomehanicke karakteristike tkiva kicmene mozdine - osnov za razvoj modifikovane tehnike DREZ operacije

2004 ◽  
Vol 51 (4) ◽  
pp. 59-64
Author(s):  
M. Spaic ◽  
Dusan Mikicic ◽  
S. Ilic ◽  
I. Milosavljevic ◽  
S. Ivanovic ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Spinal Cord ◽  
Dorsal Horn ◽  
Cauda Equina ◽  
Spinal Cord Tissue ◽  
Management Problem ◽  
Tissue Elasticity ◽  
Neurogenic Pain ◽  
Size And Shape ◽  
Drez Lesion

Mechanical properties of the spinal cord tissue - biological basis for the development of the modality of the DREZ surgery lesioning technique Successful treatment of the chronic neurogenic pain of spinal cord and cauda equina injury origin remains a significant management problem. The mechanism of this pa-in phenomenon has been shown to be related to neurochemical changes that lead to the state of hypereactivity of the second order dorsal horn neurons. The DREZ surgery (Dorsal Root Entry Zone lesion), designed to destroy anatomy structures involved in pain generating thus interrupting the neurogenic pain mechanism, as a causative procedure in treating this chronic pain, has been performed by using different technical modalities: Radiofrequency (RF) coagulation technique, Laser, Ultrasound and Microsurgical DREZotomy technic. The purpose of the study was to assess the possibility for the establishment of the lesioning technique based on the natural difference in the mechanical properties between the white and gray cord substance. We experimentally determinate mechanical properties of the human cadaveric cord white versus gray tissue for the purpose of testing possibility of selective suction of the dorsal horn gray substance as a DREZ lesioning procedure. Based on the fact of the difference in tissue elasticity between white and gray cord substance we established a new and simple DREZ surgical lesioning technique that was tested on cadaver cord. For the purpose of testing and comparing the size and shape of the DREZ lesion achieved the DREZ surgery has been performed on cadaver cord by employing selective dorsal horn suction as a lesioning method. After the procedure cadaver cord underwent histological fixation and analysis of the DREZ lesions achieved. Our result revealed that the white cord substance with longitudinal fiber structure had four time higher dynamical viscosity than gray substance of local neuronal network structure (150 PaS versus 37,5 PaS) that provided possibility for the safe and selective suction of the gray substance of the dorsal horn. Technique includes incision of the dorsolateral sulcus according to Sindous Microsurgical DREZotomy technique than suction under visual control of the dorsal horn gray matter using sucker adopted from the lumbar puncture nidle. Operative experimental testing and hystological analysis confirmed expected size and shape of the DREZ lesion performed by dorsal horn suction as DREZ lesioning technique. The utility, selectivity and safety of this technique has been provided by the natural mechanical properties of the cord tissue itself. Application of the Dorsal horn suction as a DREZ lesioning in humans confirmed this technique as a safe and reliable DREZ lesioning method.

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