[Endoplasmic reticulum stress promotes the apoptosis of testicular germ cells in hyperlipidemic rats].

OBJECTIVE: To investigate the role of endoplasmic reticulum stress in the apoptosis of testicular germ cells in hyperlipidemic rats. METHODS: We randomly assigned 42 four-week-old male Wistar rats into a normal control group (n = 12) and a high-fat group (n = 30) to be fed on a normal diet and a high-fat diet, respectively, for 10 weeks. Then we measured the concentrations of triglyceride (TG) and total cholesterol (TC) in the serum using an automatic biochemistry analyzer, detected the apoptosis of testicular germ cells by TUNEL staining, and determined the protein and mRNA expressions of GRP78 and. caspase-12 in the testis tissue by immunohistochemistry and RT-PCR, respectively. RESULTS: The concentrations of TG and TC were significantly increased in the animals of the high-fat group ([3.00 ± 0.92] and [3.04 ± 0.39] mmol/L) as compared with the control rats ([1.43 ± 0.41] and [1.55 ± 0.23] mmol/L) (P < 0.01), and so was the apoptosis index of the testicular germ cells ([37.17 ± 2.74]% vs [5.16 ± 0.81]%, P < 0.01). The high-fat group, in comparison with the control, also showed remarkably upregulated protein and mRNA expressions of GRP78 (0.32 ± 0.03 and 0.86 ± 0.05 vs 0.19 ± 0.01 and 0.37 ± 0.03, P < 0.01) and caspase-12 (0.34 ± 0.02 and 0.87 ± 0.01 vs 0.12 ± 0.01 and 0.34 ± 0.03, P < 0.01) in the testis tissue. CONCLUSION: The apoptosis of testicular germ cells is increased in hyperlipidemic rats, which may be attributed to endoplasmic reticulum stress.

New coumarin derivatives: design, synthesis and use as inhibitors of hMAO.

A series new 2H-chromene-3-carboxamides (4a-4i) and S-2H-chromene-3-carbothioates (5j-5t) were synthesized and evaluated as monoamine oxidase A and B inhibitors. Among them, compound 5k (IC50=0.21µM, IC50 iproniazid=7.65µM) showed the most activity and higher MAO-B selectivity (189.2-fold vs 1-fold) with respect to the MAO-A isoform. The need to clarify at a 3D level some important molecular aspects of discussed SAR, we undertaked a number of docking simulations to better assess. The steric effect was analyzed interms of both posing and scoring by investigating the nature of the binding interactions. The docking results of active compound 5k with hMAO-B complex indicated that conserved residue ILE 199 was important for ligand binding via Sigma-Pi interaction.

Effects of gibberellic acid, kinetin and indole butyric acid mixture on sorghum salinity tolerance and grain yield in saline-alkali coastal zone.

The development and utilization of coastal saline-alkali lands hold significant importance in mitigating the shortage of cultivated land resources in China, enhancing the agro-ecological environment in coastal saline and alkaline areas, and ensuring national food security. We set up both pot and field trials (randomized block design) at Xinxiang experimental station of Institute of Crop Science, Chinese Academy of Agricultural Sciences (ICS-CAAS) and Dongying Yellow River Delta Modern Agricultural Research Base in Shandong Province in 2021 and 2022, respectively. The experimental materials, Jiliang 1 and Jiliang 2, underwent seed dressing with GKI composites at concentrations of 2.5 and 5 mL·kg-1. These composites, which contained the main components of gibberellin, kinetin, and indole butyric acid, were denoted as GKI2.5 and GKI5.0, respectively. The control plots (CK) received water seed dressing. The aim was to assess the regulatory effects of GKI on salt tolerance and grain sorghum yield. Compared to CK, the GKI2.5 and GKI5.0 seed dressing treatments significantly enhanced the growth and development of the two grain sorghum varieties, increased antioxidant enzyme activity and soluble protein content of sorghum leaves, while reducing leaf malondialdehyde content. Moreover, the GKI treatments increased leaf net photosynthetic rate. Under field conditions, yields of Jiliang 1 and Jiliang 2 were enhanced by an average of 17.1% and 19.1%, respectively. In conclusion, GKI seed dressing treatment effectively promoted the growth and development of sorghum under salt stress. It enhanced the antioxidant and osmoregulatory capacities of leaves, reduced the level of membrane lipid peroxidation, and improved net photosynthetic rate of leaves, which together improved the salt tolerance and sorghum yield.

Screening and identification of key microRNAs and regulatory pathways associated with the renal fibrosis process.

Renal fibrosis (RF) is a chronic and fatal disease related to the gradual deterioration of kidney function. MicroRNAs (miRNAs) play a key role in cellular functions and several of them related to the pathogenesis of RF have been identified, although the underlying mechanisms are unclear. In order to explore the miRNAs involved in RF progression, we established a model in rats by the unilateral ureteral ligation method. The animals were randomly divided into the control group, and the 2 week, 4 week and 6 week model groups. The indices of renal function were measured using routine biochemical assays. The differentially expressed miRNAs (DE-miRNAs) between the sham-operated and modelled rats were screened, and their putative target genes were identified using the miRanda software and functionally annotated by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The expression of transforming growth factor ß1 (TGF-ß1), Smad3 and Smad7 was confirmed by RT-PCR. Compared to the sham-operated group, the model groups showed a decrease in SOD activity, along with the increased renal coefficient, and higher MDA, HYP, Scr, BUN and ALB levels. In addition, TGF-ß1, Smad3 and Smad7 were also upregulated in the RF groups. We identified 274 known and 11 novel DE-miRNAs in the 2 week, 114 known and 6 novel DE-miRNAs in the 4 week, and 41 known and 1 novel DE-miRNAs in the 6 week model groups. The putative target genes of these DE-miRNAs were enriched in metabolic processes, apoptosis, pyrimidine metabolism, and TNF and VEGF signalling pathways. Based on our findings, we surmise that miR-146a-3p, miR-148a-3p, miR-130a-5p, miR-362-3p and miR-122-5p are likely to be involved in the occurrence and development of RF, and miR-122-5p may play an inhibitory role. The underlying mechanisms need further investigation.

Y-shaped shunt for the treatment of Dandy-Walker malformation combined with giant arachnoid cysts: A case report.

BACKGROUND: Dandy-Walker malformation (DWM) was first reported in 1914. In this case report, a pediatric case was complicated with giant and isolated arachnoid cysts in the right cerebellar hemisphere along with the typical DWM. CASE SUMMARY: The patient was at 20 mo old boy, with the complaint of staggering for more than 2 mo. He was admitted to the hospital due to high intracranial pressure and staggering. At admission, the patient had typical manifestations of high intracranial pressure, including vomiting, poor appetite and feeding difficulty. Physical examination revealed increased head circumference, closed anterior fontanelle, unstable standing, staggering, leaning right while walking and ataxia. After admission, he was diagnosed with DWM accompanied by giant isolated arachnoid cysts in the posterior fossa. He underwent Y-shaped three-way valve repair for treating differential pressure between the supratentorial hydrocephalus and the subtentorial arachnoid cysts at once. The child recovered well after the surgery. CONCLUSION: In this case, supratentorial and subtentorial shunts were placed, which solved the problem of differential pressure between the supratentorial and subtentorial parts simultaneously. This provides useful information regarding treatment exploration in this rare disease.

Laboratory signatures differentiate the tolerance to hypothermic circulatory arrest in acute type A aortic dissection surgery.

OBJECTIVES: Our goal was to investigate whether laboratory signatures on admission could be used to identify risk stratification and different tolerance to hypothermic circulatory arrest in acute type A aortic dissection surgery. METHODS: Patients from 10 Chinese hospitals participating in the Additive Anti-inflammatory Action for Aortopathy & Arteriopathy (5A) study were randomly divided into derivation and validation cohorts at a ratio of 7:3 to develop and validate a simple risk score model using preoperative variables associated with in-hospital mortality using multivariable logistic regression. The performance of the model was assessed using the area under the receiver operating characteristic curve. Subgroup analyses were performed to investigate whether the laboratory signature-based risk stratification could differentiate the tolerance to hypothermic circulatory arrest. RESULTS: There were 1443 patients and 954 patients in the derivation and validation cohorts, respectively. Multivariable analysis showed the associations of older age, larger body mass index, lower platelet-neutrophile ratio, higher lymphocyte-monocyte ratio, higher D-dimer, lower fibrinogen and lower estimated glomerular filtration rate with in-hospital death, incorporated to develop a simple risk model (5A laboratory risk score), with an area under the receiver operating characteristic of 0.736 (95% confidence interval 0.700-0.771) and 0.715 (95% CI 0.681-0.750) in the derivation and validation cohorts, respectively. Patients at low risk were more tolerant to hypothermic circulatory arrest than those at middle to high risk in terms of in-hospital mortality [odds ratio 1.814 (0.222-14.846); odds ratio 1.824 (1.137-2.926) (P = 0.996)]. CONCLUSIONS: The 5A laboratory-based risk score model reflecting inflammatory, immune, coagulation and metabolic pathways provided adequate discrimination performances in in-hospital mortality prediction, which contributed to differentiating the tolerance to hypothermic circulatory arrest in acute type A aortic dissection surgery.Clinical Trials. gov number NCT04918108.

Synthesis of 1,5-benzothiazepine derivatives bearing 2-phenoxy-quinoline moiety via 1,3-diplolar cycloaddition reaction.

A series of 1,5-benzothiazepine derivatives were synthesized by the reaction of 1,5-benzothiazepine containing 2-phenoxy-quinoline with benzohydroximinoyl chlorides and hydrazonoyl chlorides at room temperature. The structures of these novel compounds were confirmed by spectrum, elemental, and X-ray crystallographic analysis.

Chromous carbonates containing a square-grid layer of {Cr2(CO3)4}n4n- based on a dichromium(II,II) paddlewheel core.

Polymeric coordination compounds based on Cr2n+ paddle-wheel building blocks with non-carboxylate O,O-donor ligands chelating and bridging the Cr-Cr centers have been underexplored hitherto. This paper reports the synthesis and crystal structure of a new homo-valent chromium(ii,ii) compound, Na3HCr2(CO3)4·10H2O (1). It has a two-dimensional structure in which the paddlewheel chromium(ii,ii) units of Cr2(CO3)44- are cross-linked through the carbonate groups. The layers are stacked along the [100] direction, and Na ions fill the intra and interlayer spaces with a neighboring layer distance of about 11.3 Å. The investigation of the primary magnetic properties and theoretical studies with density functional theory (DFT) reveal the partial paramagnetic properties of compound 1 arising from the Boltzmann distribution between a ground state σ2π4δ2 with S = 0 and a low-lying excited state σ2π4δδ* with S = 1 for the Cr2(ii,ii) dimer. According to Raman spectra measurements combined with theoretical calculations, the two Raman bands in the small-wavenumber region at 335 and 297 cm-1 were assigned to the vibration of the Cr-O bonds and the band at 371 cm-1 was assigned to the stretching of the Cr-Cr quadruple bond.

Natural deep eutectic solvents as tailored and sustainable media for the extraction of five compounds from compound liquorice tablets and their comparison with conventional organic solvents.

An efficient and environmentally friendly ultrasound-assisted (UAE) natural deep eutectic solvent (NADES) extraction method was applied for the extraction of five bioactive compounds (liquiritin, isoliquiritin, liquiritigenin, glycyrrhizic acid and isoliquiritigenin) from compound liquorice tablets (CPLTs), and the antioxidant activities of these compounds were evaluated. In this study, eighteen different NADES systems based on either two or three components were tested and a 1,4-butanediol-levulinic acid system (1 : 3 molar ratio) was selected as a topgallant solvent for maximizing analyte extraction yields. Various extraction parameters, such as water content, liquid/solid ratio, extraction time and temperature, were systematically optimized by single-factor and response surface methodology (RSM) experiments. The results indicated that the optimum extraction conditions for the analytes featured a water content of 17%, a liquid/solid ratio of 42 mL g-1 and an extraction time of 30 min. The extracted amounts of liquiritin, isoliquiritin, liquiritigenin, glycyrrhizic acid and isoliquiritigenin reached 5.60, 3.17, 1.27, 74.62 and 1.34 mg g-1, respectively, under optimized conditions, which were much higher than those extracted using conventional organic solvents. In addition, antioxidant tests revealed that the NADES extracts showed higher DPPH and hydroxyl radical-scavenging capacity than the conventional solvent extracts used for comparison. This study provides a suitable approach for efficiently extracting the bioactive compounds of CPLTs. Meanwhile, NADESs can be extended to other natural products as green extraction media.

Effects of basic application of chlorocholine chloride combined with nitrogen fertilizer on nitrogen use of summer maize in North China Plain.

To clarify the effects of combined applications of chlorocholine chloride (CCC) and nitrogen fertilizer (CN) on nitrogen metabolism and nitrogen use efficiency of summer maize, we conducted a field experiment in Xinxiang experimental station of Chinese Academy of Agricultural Sciences in 2018 and 2019, with four nitrogen application rates (0, 62.5, 125 and 187.5 kg·hm-2), and two maize varieties of Jingnongke 728 (JNK728) and Zhongdan 909 (ZD909). The results showed that across the two years CN-CCC increased maize yield by 7.7% and 5.0% under the nitrogen application rates of 62.5 kg·hm-2 and 125 kg·hm-2, respectively. CN-CCC increased the contents of nitrate reductase, glutamine synthetase, glutamate synthetase and soluble protein, and finally promoted nitrogen metabolism. Under the low and middle nitrogen application conditions (62.5 kg·hm-2 and 125 kg·hm-2), plant nitrogen content of JNK728 and ZD909 increased by 17.6% and 30.3%, grain nitrogen content increased by 10.3% and 17.4%, nitrogen partial productivity, agronomic efficiency of applied nitrogen, recovery efficiency of applied nitrogen, nitrogen use efficiency increased by 10.0%, 15.7%, 23.3%, 24.8% and 5.7%, 15.0%, 49.9%, 71.7%, respectively. In conclusion, appropriate basic application of CN-CCC could enhance nitrogen metabolism, increase nitrogen use efficiency and grain yield of summer maize. Our results showed that CCC combined basic nitrogen application of 125 kg·hm-2 had the best effect.

Effect of self-assembly on fluorescence in magnetic multiphase flows and its application on the novel detection for COVID-19.

In the present study, the magnetic field induced self-assembly processes of magnetic microparticles in an aqueous liquid (the pure magnetic fluid) and nonmagnetic microparticles in ferrofluid (the inverse magnetic fluid) are experimentally investigated. The microparticles are formed into chain-like microstructures in both the pure magnetic fluid and the inverse magnetic fluid by applying the external magnetic field. The fluorescence parameters of these self-assembled chain-like microstructures are measured and compared to those without the effect of magnetic field. It is found that the fluorescence in the pure magnetic fluid is weakened, because the scattering and illuminating areas are reduced in the microstructures. On the contrary, the fluorescence in the inverse magnetic fluid is enhanced, because more fluorescent nonmagnetic microparticles are enriched and become detectable under the effect of the magnetic dipole force and the magnetic levitational force, and their unnecessary scattering can be absorbed by the surrounding ferrofluid. The average enhancement of the fluorescence area ratio in the inverse magnetic fluid with 3 µm nonmagnetic microparticles reaches 112.92%. The present work shows that the inverse magnetic fluid has advantages such as low cost, no scattering effect, stable fluorescence intensity, and relatively low magnetic resistance. In the end, a prototype design for the novel detection of coronavirus disease 2019 based on the magnetic field induced self-assembly in the inverse magnetic fluid is proposed, which could support the epidemic prevention and control.

The lncRNA EGFR-AS1 is linked to migration, invasion and apoptosis in glioma cells by targeting miR-133b/RACK1.

Glioblastoma multiforme (GBM) is the most common in situ neoplasms in central nervous system (CNS). However, the pathogenesis of GBM is poorly understood. Long noncoding RNAs (lncRNAs) have been implicated in GBM progression. In this study, we attempted to identify the biological role of the EGFR-AS1 in glioma cells and tissues, as well as reveal the molecular mechanism associated. The results indicated that lnc-EGFR-AS1 expression was increased in glioma cells and tissues. EGFR-AS1 knockdown suppressed proliferation, migration and invasion of glioma cells, but induced apoptosis. Additionally, lnc-EGFR-AS1 functioned as a sponge for miR-133b. Promoting lnc-EGFR-AS1 expression significantly reduced miR-133b expression. Furthermore, miR-133b could target the 3'-untranslated region (3'-UTR) of RACK1 and reduced its expression levels. What's more, lnc-EGFR-AS1 knockdown reduced RACK1 expression partly through enhancing miR-133b expression. In vivo experiments confirmed the anti-tumorigenesis capability of EGFR-AS1 knockdown. These findings elucidated that EGFR-AS1 accelerated cell proliferation, migration, invasion and prevented apoptosis in glioma cells by regulating miR-133b/RACK1, providing new insights for the diagnosis and molecular therapy of GBM.

Treadmill training improves neurological deficits and suppresses neuronal apoptosis in cerebral ischemic stroke rats.

Rehabilitation training is believed to be beneficial to patients with stroke, but its molecular mechanism is still unclear. Rat models of cerebral ischemic stroke were established by middle cerebral artery occlusion/reperfusion, and then received treadmill training of different intensities, twice a day for 30 minutes for 1 week. Low-intensity training was conducted at 5 m/min, with a 10-minute running, 10-minute rest, and 10-minute running cycle. In the moderate-intensity training, the intensity gradually increased from 5 m/min to 10 m/min in 5 minutes, with the same rest cycle as above. In high-intensity training, the intensity gradually increased from 5 m/min to 25 m/min in 5 minutes, with the same rest cycle as above. The Bederson scale was used to evaluate the improvement of motor function. Infarct volume was detected using 2,3,5-triphenyltetrazolium chloride staining. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining was applied to detect the apoptosis of nerve cells in brain tissue. Western blot assay was employed to analyze the activation of cyclic adenosine monophosphate (cAMP)/protein kinase A and Akt/glycogen synthase kinase-3ß signaling pathways in rat brain tissue. All training intensities reduced the neurological deficit score, infarct volume, and apoptosis in nerve cells in brain tissue of stroke rats. Training intensities activated the cAMP/protein kinase A and Akt/glycogen synthase kinase-3 beta signaling pathways. This activation was more obvious with higher training intensities. These changes were reversed by intracerebroventricular injection of protein kinase A inhibitor Rp-cAMP. Our findings indicate that the neuroprotective effect of rehabilitation training is achieved via activation of the cAMP/protein kinase A and Akt/glycogen synthase kinase-3 beta signaling pathways. This study was approved by the Ethics Committee of Animal Experimentation in Shanghai No. 8 People's Hospital, China.

Involvement of serotonin 2A receptors in the analgesic effect of tramadol in mono-arthritic rats.

The analgesic effects of tramadol are considered to be mediated by both the opioid system and the serotonergic system. This study investigated the involvement of a subtype of serotonin receptors, 5-hydroxytryptamine (5-HT)2A receptor, in the analgesic effect of tramadol. The intraperitoneal (i.p.) injection of tramadol reduced the paw withdrawal latency (PWL) to radiant heat testing in mono-arthritic rats. The antagonistic effect of i.p. ketanserin (a 5-HT2A receptor antagonist) on tramadol analgesia was observed. The expression of the 5-HT2A receptor mRNA in the nucleus of raphe magnus (NRM), ventrolateral periaqueductal gray (vlPAG) and spinal dorsal horn of mono-arthritic rats after a ten-day treatment with tramadol was measured with in situ hybridization. Either single injections or 10 days of tramadol treatment dose-dependently elevated PWL of arthritic rats while ketanserin could partially antagonize the tramadol analgesic effect. Expression of the 5-HT2A receptor mRNA in NRM, ipsilateral vlPAG, and the ipsilateral spinal dorsal horn of arthritic rats was significantly increased after tramadol treatment. These results suggest that 5-HT2A receptors are involved in the analgesic effect of tramadol. This study provides evidence for involvement of 5-HT2A receptors in the tramadol analgesia of inflammatory pain. The increase in this receptor mRNA in the chronic study may contribute to the sustaining effect of tramadol long-term treatments in clinical practice.

2D Photonic Crystal Hydrogel Sensor for Tear Glucose Monitoring.

Photonic crystal (PC) materials have huge potentials as sensors for noninvasive and real-time monitoring glucose in tears. We developed a glucose-sensitive PC material based on monolayered colloidal crystals (MCCs). Polystyrene nanoparticles were first self-assembled into a highly ordered MCC, and this two-dimensional (2D) template was then coated by a 4-boronobenzaldehyde-functionalized poly(vinyl alcohol) hydrogel. Such a sensor efficiently diffracts visible light, whose structural color could change from red through yellow to green, as the glucose concentration altered from 0 to 20 mM, covering both tears' and bloods' physiological ranges. The sensor also represents a rapid response within 180 s at each titration of glucose, combining the characteristics of high accuracy and sensitivity in detecting the glucose concentration in tears, and this intelligent sensing material presents certain possibility for the frontier point-of-care glucose monitoring.

Down-regulation of GFRalpha-1 expression by antisense oligodeoxynucleotide aggravates thermal hyperalgesia in a rat model of neuropathic pain.

Glial cell line-derived neurotrophic factor (GDNF) has been hypothesized to play an important role in the modulation of nociceptive signals especially during neuropathic pain. The present study examined the expression of GDNF and GFRalpha-1 (the high-affinity receptor of GDNF) in dorsal root ganglions (DRG) in a rat model of neuropathic pain induced by chronic constriction injury (CCI) to the sciatic nerve. In order to address the role of GDNF and GFRalpha-1 in neuropathic pain, antisense oligodeoxynucleotide (ODN) specifically against GFRalpha-1 was intrathecally administered to result in down-regulation of GFRalpha-1 expression. The results showed that both the protein and mRNA levels of GDNF and GFRalpha-1 were significantly increased after CCI, while the thermal hyperalgesia of neuropathic pain rats could be significantly aggravated by antisense ODN treatment, but not by normal saline (NS) or mismatch ODN treatment. The present study demonstrated that endogenous GDNF and GFRalpha-1 might play an anti-hyperalgesic role in neuropathic pain of rats. In addition, we found a down-regulation of somatostatin (SOM) in DRG and spinal dorsal horn after expression of GFRalpha-1 was knocked down, which suggested the possible relationship between the anti-hyperalgesic effect of GDNF and GFRalpha-1 on neuropathic pain and endogenous SOM.

Stage-dependent analgesia of electro-acupuncture in a mouse model of cutaneous cancer pain.

Acupuncture is one of the most effective alternative medical treatments in pain management with the advantages of simple application, low cost and minimal side effects. However its scientific evidence and laws of action are not very clear in cancer pain relieving. The aim of this study was to examine the immediate and therapeutic anti-hyperalgesic effect of electro-acupuncture (EA) on a mouse model of cutaneous cancer pain. B16-BL6 melanoma cells were inoculated into the plantar region of unilateral hind paw and the thermal hyperalgesia was measured by using radiant heat test and hot plate test. C57BL/6 mice showed moderate and marked hyperalgesia during days 8-12 and from day 14 after the orthotopic inoculation of B16-BL6 melanoma cells into the hind paw. Single EA on day 8 after inoculation showed significant analgesic effect immediately after the treatment, the analgesic effect reached its maximum within 15-30min and declined to its minimum at 50min after EA treatment. Single EA treatment on day 20 showed no significant analgesic effect; Repeated EA treatments (started from day 8, once every other day) showed therapeutic analgesic effect, while it showed no therapeutic effect when started from day 16, a relatively late stage of this cancer pain model. The results demonstrated that EA had anti-hyperalgesic effect on early stage of cutaneous cancer pain but not on late stage. These results indicated a tight correlation of EA anti-hyperalgesic effects with the time window of cancer pain.

Down-regulation of GFRalpha-1 expression by antisense oligodeoxynucleotide attenuates electroacupuncture analgesia on heat hyperalgesia in a rat model of neuropathic pain.

Glial cell line-derived neurotrophic factor (GDNF) has been proved to play an important role in the modulation of nociceptive transmission especially during neuropathic pain. It was reported that electroacupuncture (EA) had potent analgesic effect on neuropathic pain and our previous studies indicated that EA could activate endogenous GDNF signaling system (GDNF and its receptor GFRalpha-1) in dorsal root ganglions (DRGs) of neuropathic pain rats. In order to investigate whether GDNF signaling system was involved in EA analgesia on neuropathic pain, which was induced by chronic constriction injury (CCI) of the sciatic nerve in rats, antisense oligodeoxynucleotide (ODN) specifically against GFRalpha-1 was used in the present study to result in down-regulation of GFRalpha-1 expression. The results showed that: (1) cumulative EA had potent analgesic effect on neuropathic pain in rats; (2) the expression of GFRalpha-1 in DRGs was down-regulated by intrathecal delivery of antisense ODN, but not by normal saline (NS) or mismatch ODN; (3) EA analgesia was significantly attenuated by antisense ODN treatment. The present study demonstrated that endogenous GDNF signaling system was involved in EA analgesia on neuropathic pain in rats, which would deepen our realization of the mechanism of EA analgesia.

Expression of ORL1 mRNA in some brain nuclei in neuropathic pain rats.

The present study was designed to investigate changes of opioid receptor like 1 receptor (ORL(1), NOP) mRNA expression in some pain-related brain nuclei of neuropathic pain rats using in situ hybridization technique. Nociceptin/orphanin FQ (N/OFQ), the endogenous ligand of ORL(1), plays an important role in neuropathic pain through its receptor. There are ORL(1) mRNA expression in the nucleus of raphe magnus (NRM), ventrolateral periaqueductal gray (vlPAG) and dorsal raphe nucleus (DRN) of rat mesencephalon. In the sciatic nerve chronic constriction injury (CCI)-induced neuropathic pain model, a significant increase of ORL(1) mRNA expression was observed in these three regions on the 7th day after operation, and the changes lasted for 2 weeks. The result indicated that ORL(1) synthesis was increased in NRM, vlPAG and DRN of neuropathic pain rats, suggesting that ORL(1) was involved in nociceptive transmission of neuropathic pain.

Changes of expression of glial cell line-derived neurotrophic factor and its receptor in dorsal root ganglions and spinal dorsal horn during electroacupuncture treatment in neuropathic pain rats.

Injury to the nervous system occasionally leads to intense and persistent neuropathic pain, which is resistant to conventional analgesic methods. It was reported that electroacupuncture (EA) had potent analgesic effect on neuropathic pain by activating various endogenous transmitters such as the opioid peptides. Glial cell line-derived neurotrophic factor (GDNF) has been hypothesized to play an important role in modulation of nociceptive signals especially during neuropathic pain state. Using immunohistochemistry, Western blot, and RT-PCR analysis techniques, the present study observed the effects of EA on the expression of GDNF and GDNF family receptor alpha-1 (GFRalpha-1, the high-affinity receptor of GDNF) in neuropathic pain rats. The results showed that both protein and mRNA levels of GDNF and GFRalpha-1 in the dorsal root ganglions (DRG), as well as GDNF protein in the spinal dorsal horn, were significantly increased after chronic constriction injury (CCI) of the rats' sciatic nerve and could be further enhanced by EA treatment. The present data demonstrated that EA could activate endogenous GDNF and GFRalpha-1 system of neuropathic pain rats and this might underlie the effectiveness of EA in the treatment of neuropathic pain.