Anion exchanger 3 in dorsal root ganglion contributes to nerve injury-induced chronic mechanical allodynia and thermal hyperalgesia

2018 ◽  
Vol 70 (3) ◽  
pp. 374-382 ◽  
Author(s):  
Marian J. Pérez-Rodríguez ◽  
Isabel Velazquez-Lagunas ◽  
Alejandro Pluma-Pluma ◽  
Paulino Barragán-Iglesias ◽  
Vinicio Granados-Soto
2020 ◽  
Author(s):  
Cunjin Wang ◽  
Yuchen Pan ◽  
Wenwen Zhang ◽  
Ying Chen ◽  
Chuhan Li ◽  
...  

Background The transcriptional repressor positive regulatory domain I–binding factor 1 (PRDM1) is expressed in adult mouse dorsal root ganglion and regulates the formation and function of peripheral sensory neurons. The authors hypothesized that PRDM1 in the dorsal root ganglion may contribute to peripheral nerve injury–induced nociception regulation and that its mechanism may involve Kv4.3 channel transcriptional repression. Methods Nociception was induced in C57BL/6 mice by applying chronic constriction injury, complete Freund’s adjuvant, or capsaicin plantar injection. Nociceptive response was evaluated by mechanical allodynia, thermal hyperalgesia, cold hyperalgesia, or gait analysis. The role of PRDM1 was evaluated by injection of Prdm1 knockdown and overexpression adeno-associated viruses. The interaction of PRDM1 at the Kv4.3 (Kcnd3) promoter was evaluated by chromatin immunoprecipitation assay. Excitability of dorsal root ganglion neurons was evaluated by whole cell patch clamp recordings, and calcium signaling in spinal dorsal horn neurons was evaluated by in vivo two-photon imaging. Results Peripheral nerve injury increased PRDM1 expression in the dorsal root ganglion, which reduced the activity of the Kv4.3 promoter and repressed Kv4.3 channel expression (injured vs. uninjured; all P < 0.001). Knockdown of PRDM1 rescued Kv4.3 expression, reduced the high excitability of injured dorsal root ganglion neurons, and alleviated peripheral nerve injury–induced nociception (short hairpin RNA vs. Scram; all P < 0.05). In contrast, PRDM1 overexpression in naive mouse dorsal root ganglion neurons diminished Kv4.3 channel expression and induced hyperalgesia (PRDM1 overexpression vs. control, mean ± SD; n = 13; all P < 0.0001) as evaluated by mechanical allodynia (0.6 ± 0.3 vs. 1.2 ± 0.2 g), thermal hyperalgesia (5.2 ± 1.3 vs. 9.8 ± 1.7 s), and cold hyperalgesia (3.4 ± 0.5 vs. 5.3 ± 0.6 s). Finally, PRDM1 downregulation in naive mice reduced the calcium signaling response of spinal dorsal horn neurons to thermal stimulation. Conclusions PRDM1 contributes to peripheral nerve injury–induced nociception by repressing Kv4.3 channel expression in injured dorsal root ganglion neurons. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Guiqin Zhu ◽  
Yanbin Dong ◽  
Xueming He ◽  
Ping Zhao ◽  
Aixing Yang ◽  
...  

Radiotherapy is one of the major clinical approaches for treatment of bone cancer pain. Activation of cAMP-PKA signaling pathway plays important roles in bone cancer pain. Here, we examined the effects of radiotherapy on bone cancer pain and accompanying abnormal activation of cAMP-PKA signaling. Female Sprague-Dawley rats were used and received tumor cell implantation (TCI) in rat tibia (TCI cancer pain model). Some of the rats that previously received TCI treatment were treated with X-ray radiation (radiotherapy). Thermal hyperalgesia and mechanical allodynia were measured and used for evaluating level of pain caused by TCI treatment. PKA mRNA expression in dorsal root ganglion (DRG) was detected by RT-PCR. Concentrations of cAMP, IL-1β, and TNF-αas well as PKA activity in DRG and the spinal cord were measured by ELISA. The results showed that radiotherapy significantly suppressed TCI-induced thermal hyperalgesia and mechanical allodynia. The level of PKA mRNA in DRG, cAMP concentration and PKA activity in DRG and in the spinal cord, and concentrations of IL-1βand TNF-αin the spinal cord were significantly reduced by radiotherapy. In addition, radiotherapy also reduced TCI-induced bone loss. These findings suggest that radiotherapy may suppress bone cancer pain through inhibition of activation of cAMP-PKA signaling pathway in DRG and the spinal cord.


2008 ◽  
Vol 108 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Xiaoping Gu ◽  
Liling Yang ◽  
Shuxing Wang ◽  
Backil Sung ◽  
Grewo Lim ◽  
...  

Background Radicular pain is a common and debilitating clinical pain condition. To date, the mechanisms of radicular pain remain unclear, partly because of the lack of suitable preclinical models. The authors report a modified rat model of radicular pain that could mimic a subset of clinical radicular pain conditions induced by the soft tissue compression on dorsal root ganglion. Methods A rat model of radicular pain was produced by infiltrating the L5 intervertebral foramen with 60 microl of a hemostatic matrix (SURGIFLO; Johnson & Johnson, Somerville, NJ) resulting in chronic compression of lumbar dorsal root ganglion. Thermal hyperalgesia and mechanical allodynia were measured with or without epidural treatment with triamcinolone. Western blot was used to assess the expression of the NR1 subunit of the N-methyl-D-aspartate receptor and inhibitory factor kappabeta-alpha, an inflammatory marker, within the affected L5 dorsal root ganglion and spinal cord dorsal horn. Results Chronic compression of lumbar dorsal root ganglion resulted in: (1) persistent mechanical allodynia and thermal hyperalgesia up to 4 or 5 postoperative weeks and (2) up-regulation of the N-methyl-D-aspartate receptor and inhibitory factor kappabeta-alpha within the ipsilateral L5 dorsal root ganglion and spinal cord dorsal horn. Epidural administration of triamcinolone (6.25-100 microg) on postoperative day 3 dose-dependently attenuated both thermal hyperalgesia and mechanical allodynia in rats with chronic compression of lumbar dorsal root ganglion. Conclusion The data suggest that this modified rat model of chronic compression of lumbar dorsal root ganglion may be a useful tool to explore the mechanisms as well as new therapeutic options of radicular pain.


2009 ◽  
Vol 110 (2) ◽  
pp. 387-400 ◽  
Author(s):  
Xue-Song Song ◽  
Zhi-Jiang Huang ◽  
Xue-Jun Song

Background B vitamins can effectively attenuate inflammatory and neuropathic pain in experimental animals, while their efficacy in treating clinical pain syndromes remains unclear. To understand possible mechanisms underlying B vitamin-induced analgesia and provide further evidence that may support the clinical utility of B vitamins in chronic pain treatment, this study investigated effects of thiamine (B1) on the excitability and Na currents of dorsal root ganglion (DRG) neurons that have been altered by nerve injury. Methods Nerve injury was mimicked by chronic compression of DRG in rats. Neuropathic pain was evidenced by the presence of thermal hyperalgesia. Intracellular and patch-clamp recordings were made in vitro from intact and dissociated DRG neurons, respectively. Results (1) In vivo intraperitoneal administration of B1 (66 mg/kg/day, 10-14 doses) significantly inhibited DRG compression-induced neural hyperexcitability, in addition to suppressing thermal hyperalgesia. (2) In vitro perfusion of B1 (0.1, 1 and 10 mM) resulted in a dose-dependent inhibition of DRG neuron hyperexcitability. In addition, the DRG neurons exhibited size-dependent sensitivity to B1 treatment, i.e., the small and the medium-sized neurons, compared to the large neurons, were significantly more sensitive. (3) Both in vitro (1 mM) and in vivo application of B1 significantly reversed DRG compression-induced down-regulation of tetrodotoxin-resistant but not tetrodotoxin-sensitive Na current density in the small neurons. B1 at 1 mM also reversed the compression-induced hyperpolarizing shift of the inactivation curve of the tetrodotoxin-resistant currents and the upregulated ramp currents in small DRG neurons. Conclusion Thiamine can reduce hyperexcitability and lessen alterations of Na currents in injured DRG neurons, in addition to suppressing thermal hyperalgesia.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Qun Wang ◽  
Yanyuan Sun ◽  
Yingna Ren ◽  
Yandong Gao ◽  
Li Tian ◽  
...  

Matrix metalloproteinases (MMPs) are widely implicated in inflammation and tissue remodeling associated with various neurodegenerative diseases and play an important role in nociception and allodynia. Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) plays a key regulatory role for MMP activities. However, the role of EMMPRIN in the development of neuropathic pain is not clear. Western blotting, real-time quantitative RT-PCR (qRT-PCR), and immunofluorescence were performed to determine the changes of messenger RNA and protein of EMMPRIN/OX47 and their cellular localization in the rat dorsal root ganglion (DRG) after nerve injury. Paw withdrawal threshold test was examined to evaluate the pain behavior in spinal nerve ligation (SNL) model. The lentivirus containing OX47 shRNA was injected into the DRG one day before SNL. The expression level of both mRNA and protein of OX47 was markedly upregulated in ipsilateral DRG after SNL. OX47 was mainly expressed in the extracellular matrix of DRG. Administration of shRNA targeted against OX47 in vivo remarkably attenuated mechanical allodynia induced by SNL. In conclusion, peripheral nerve injury induced upregulation of OX47 in the extracellular matrix of DRG. RNA interference against OX47 significantly suppressed the expression of OX47 mRNA and the development of mechanical allodynia. The altered expression of OX47 may contribute to the development of neuropathic pain after nerve injury.


2020 ◽  
Vol 18 (10) ◽  
pp. 791-797
Author(s):  
Qiong Xiang ◽  
Jing-Jing Li ◽  
Chun-Yan Li ◽  
Rong-Bo Tian ◽  
Xian-Hui Li

Background: Our previous study has indicated that somatostatin potently inhibits neuropathic pain through the activation of its type 2 receptor (SSTR2) in mouse dorsal root ganglion and spinal cord. However, the underlying mechanism of this activation has not been elucidated clearly Objective: The aim of this study is to perform the pharmacological studies on the basis of sciatic nerve-pinch mice model and explore the underlying mechanism involving SSTR2. Methods: On the basis of a sciatic nerve-pinch injury model, we aimed at comparing the painful behavior and dorsal root ganglion neurons neurochemical changes after the SSTR2 antibody (anti- SSTR2;5μl,1μg/ml) administration in the mouse. Results: After pinch nerve injury, we found that the mechanical hyperalgesia and severely painful behavior (autotomy) were detected after the application of SSTR2 antibody (anti-SSTR2; 5μl, 1μg/ml) on the pinch-injured nerve. The up-regulated phosphorylated ERK (p-ERK) expression and the apoptotic marker (i.e., Bax) were significantly decreased in DRGs after anti-SSTR2 treatment. Conclusion: The current data suggested that inhibitory changes in proteins from the apoptotic pathway in anti-SSTR2-treated groups might be taking place to overcome the protein deficits caused by SSTR2 antibody and supported the new therapeutic intervention with SSTR2 antagonist for neuronal degeneration following nerve injury.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Xueru Xu ◽  
Shaoxiong Fu ◽  
Xiaomei Shi ◽  
Rongguo Liu

Background. Pulsed radiofrequency (PRF) on the dorsal root ganglion (DRG) has been applied to alleviate neuropathic pain effectively, yet the mechanisms underlying pain reduction owing to this treatment are not clarified completely. The activated microglia, brain-derived neurotrophic factor (BDNF), phosphatidylinositol 3-kinase (PI3K), and phosphorylated extracellular signal-regulated kinase (p-ERK) in the spinal cord were demonstrated to be involved in developing neuropathic pain. Also, it has been just known that PRF on DRG inhibits the microglial activation in nerve injury rats. Here, we aim to investigate whether PRF treatment could regulate the levels of BDNF, PI3K, and p-ERK in the spinal cord of rats with spared nerve injury (SNI) via suppressing the spinal microglia activation to ease neuropathic pain. Methods. The rats with SNI were intrathecally treated with minocycline (specific microglia inhibitor) or same volume of dimethyl sulfoxide once daily, beginning from 1 h before nerve transection to 7 days. PRF was applied adjacent to the L4-L5 DRG of rats with SNI at 45 V for 6 min on the seventh postoperative day, whereas the free-PRF rats were treated without PRF. The withdrawal thresholds were studied, and the spinal levels of ionized calcium-binding adapter molecule 1 (Iba1), BDNF, PI3K, and p-ERK were calculated by western blot analysis, reverse transcription-polymerase chain reaction, and immunofluorescence. Results. The paw withdrawal mechanical threshold and paw withdrawal thermal latency decreased in the ipsilateral hind paws after SNI, and the spinal levels of Iba1, BDNF, PI3K, and p-ERK increased on day 21 after SNI compared with baseline (P<0.01). An intrathecal injection of minocycline led to the reversal of SNI-induced allodynia and increase in levels of Iba1, BDNF, PI3K, and p-ERK. Withdrawal thresholds recovered partially after a single PRF treatment for 14 days, and SNI-induced microglia hyperactivity, BDNF upregulation, and PI3K and ERK phosphorylation in the spinal cord reduced on D14 due to the PRF procedure. Conclusion. Microglial BDNF, PI3K, and p-ERK in the spinal cord are suppressed by the therapy of PRF on DRG to ease SNI-induced neuropathic pain in rats.


2010 ◽  
Vol 68 ◽  
pp. e159
Author(s):  
Takashi Hirai ◽  
Mitsuhiro Enomoto ◽  
Madoka Ukegawa ◽  
Shinichi Sotome ◽  
Yoshiaki Wakabayashi ◽  
...  

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