Jiari Lin

Effect of tetramethylpyrazine on DRG neuron P2X3 receptor involved in transmitting pain after burn.

UNLABELLED A burn is a severe injury, and the resulting pain can be very significant. Currently, opioids are the primary method of pain management, but these drugs have side effects; thus, it is of prime focus to research the mechanisms of pain formation and analgesic drugs. OBJECTIVE To investigate the effects of tetramethylpyrazine (TMP) on burn pain mediated by the P2X3 receptor. METHODS First-degree and superficial second-degree burn models were used. The mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were measured, and P2X3 receptor expression on nerve terminals in burn-injured skin were detected by immunohistochemistry. The effects of TMP on the P2X receptor agonist-activated currents in freshly isolated burn-injured rat dorsal root ganglion (DRG) neurons were studied by whole-cell patch-clamp technique. MAIN RESULTS One hour following the procedure, MWT and TWL in first and second-degree paw-burns with normal saline (NS) treatment were lower than those in the unburned control group and lasted for 24 or 96 h, respectively (p<0.01). After 24 h, MWT and TWL in the first-degree paw-burn with TMP treatment were significantly increased as compared with NS treatment; no difference was found when compared to the unburned control group. MWT and TWL in the second-degree paw-burn in the TMP treatment group were significantly increased at 48 h compared to NS treatment. No difference was found with the values for the unburned control group after 72 h. On day 3 after the burn, P2X3-receptor expression in the nerve terminal in the burn-injured skin of the first- and second-degree dorsal burns in the NS treatment group was higher than those in other groups (p<0.05). After treatment with TMP, P2X3-receptor expression of the nerve terminal in the first- and second-degree dorsal burns of the TMP treatment group was significantly decreased. ATP-activated currents (IATP) on the DRG neurons of the second-degree dorsal burn in the NS treatment group were markedly higher than those in the second-degree dorsal burns in the TMP treatment group and the unburned control group (p<0.05); there were no significant differences between the second-degree dorsal burn in the TMP treatment group and the unburned control group (p>0.05). CONCLUSION TMP alleviates nociceptive transmission of burn-injury pain mediated by the P2X3 receptor.

Effect of sodium ferulate on the hyperalgesia mediated by P2X3 receptor in the neuropathic pain rats

Neuropathic pain is usually persistent and there is no effective treatment. Activation of P2X(3) receptor subtype in primary sensory neurons is involved in neuropathic pain. Sodium ferulate (SF) is an active principle from Chinese herbal medicine and has anti-inflammatory activities. This study observed the effects of SF on the hyperalgesia mediated by P2X(3) receptor of rats after chronic constriction injury (CCI). Mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were measured and the expression of P2X(3) receptor immunoreactivity and protein in dorsal root ganglion (DRG) neurons was analyzed by immunohistochemistry and western blotting. In CCI rats treated with SF, the MWT and TWL were increased compared with CCI rats treated with normal saline. The expression of P2X(3) receptor in DRG neurons was increased after CCI. In CCI rats treated with SF, the up-regulated expression of P2X(3) receptor in DRG neurons was reduced. SF may reduce the thermal and mechanical hyperalgesia in CCI rat model by decreasing the pain transmitted by primary afferant neurons mediated by P2X(3) receptor during the chronic neuropathic pain injury.

Expressions of P2X2 and P2X3 receptors in rat nodose neurons after myocardial ischemia injury

The role of ATP is as a functional neurotransmitter and local intercellular signaling molecule. The nodose neurons express both P2X(2) and P2X(3) subunits in their plasma membrane. This study wants to observe the expression of P2X(2) receptor and the expression relationship between P2X(2) and P2X(3) in nodose neurons after myocardial ischemic injury. The expressions of P2X(3) immunoreactivity, mRNA and protein were analyzed by immunohistochemistry, in situ hybridization and western blotting. P2X(2) and P2X(3) immunoreactivity, mRNA expression had been increased after myocardial ischemia in nodose neurons. Myocardial ischemia enhanced P2X(2) and P2X(3) protein level in nodose ganglia after myocardial ischemia. P2X(2) receptor in nodose neurons participated in the transmission of cardiac pain. The changes of P2X(2) and P2X(3) immunoreactivities, mRNA and protein that occurred following myocardial ischemic injury in the nodose ganglia showed that a correlation existed between P2X(2) and P2X(3) expression. It suggests that P2X(2) receptor subtype in company with P2X(3) receptor subtype plays the important role in cardiac vagal sensory nociceptors with a sensitivity to ATP.The role of ATP is as a functional neurotransmitter and local intercellular signaling molecule. The nodose neurons express both P2X(2) and P2X(3) subunits in their plasma membrane. This study wants to observe the expression of P2X(2) receptor and the expression relationship between P2X(2) and P2X(3) in nodose neurons after myocardial ischemic injury. The expressions of P2X(3) immunoreactivity, mRNA and protein were analyzed by immunohistochemistry, in situ hybridization and western blotting. P2X(2) and P2X(3) immunoreactivity, mRNA expression had been increased after myocardial ischemia in nodose neurons. Myocardial ischemia enhanced P2X(2) and P2X(3) protein level in nodose ganglia after myocardial ischemia. P2X(2) receptor in nodose neurons participated in the transmission of cardiac pain. The changes of P2X(2) and P2X(3) immunoreactivities, mRNA and protein that occurred following myocardial ischemic injury in the nodose ganglia showed that a correlation existed between P2X(2) and P2X(3) expression. It suggests that P2X(2) receptor subtype in company with P2X(3) receptor subtype plays the important role in cardiac vagal sensory nociceptors with a sensitivity to ATP.

Role of sodium ferulate in the nociceptive sensory facilitation of neuropathic pain injury mediated by P2X3 receptor

Neuropathic pain usually is persistent and no effective treatment. ATP plays an important role in the initiation of pain. P2X(3) receptors are localized in the dorsal root ganglion (DRG) neurons and activated by extracellular ATP. Sodium ferulate (SF) is an active principle from Chinese herbal medicine and has anti-inflammatory activities. This study observed the effects of SF on the nociceptive facilitation of the primary sensory afferent after chronic constriction injury (CCI) mediated by P2X(3) receptor. In this study, the content of ATP in DRG neurons was measured by high-performance liquid chromatography (HPLC). P2X(3) agonist-activated currents in DRG neurons was recorded by the whole-cell patch-clamp skill. The expression of P2X(3) mRNA in DRG neurons was analyzed by in situ hybridization. The ATP content of DRG was increased after CCI. In CCI rats treated with SF, the content of ATP in DRG neurons was reduced. SF decreased the increment of P2X(3) agonist-activated currents and P2X(3) mRNA expression in DRG neurons during CCI. SF may inhibit the initiation of pain and primary afferent sensitization mediated by P2X(3) receptor during CCI.

Effect of puerarin on P2X3 receptor involved in hyperalgesia after burn injury in the rat.

The study investigated the effects of puerarin on P2X(3) receptor involved in hyperalgesia after burn injury in the rat. Superficial second degree burn injury models were adopted. Mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were measured and the P2X(3) receptor expressions in dorsal root ganglion (DRG) from burn injury models rats were detected by immunohistochemistry, in situ hybridization, RT-PCR and western blot. MWL and TWL in untreated superficial second paw burn rats were reduced. MWL and TWL of puerarin-treated superficial second paw burn rats showed significant increase compared with untreated superficial second paw burn rats. Puerarin can decrease the hyperalgesia after burn injury. At day 3 post-burn, the expressions of P2X(3) protein and mRNA in DRG neurons in untreated superficial second degree back burn group were increased significantly compared with sham back burn group, puerarin-treated back unburned control group, blank back control group, while in puerarin-treated superficial second degree back burn group, the P2X(3) protein and mRNA expressions were decreased markedly. There is no significant difference in sham back burn group, puerarin-treated back unburned control group, blank back control group. Therefore, puerarin may reduce the nociceptive transmission of burn injury pain mediated by P2X(3) receptor and alleviate P2X(3) receptor involved in hyperalgesia after burn injury in the rats.

A genome-wide association study combining pathway analysis for typical sporadic amyotrophic lateral sclerosis in Chinese Han populations

Sporadic amyotrophic lateral sclerosis (sALS) is a severe neurodegenerative disease that causes progressive motor neuron death. Although the etiology of sALS remains unknown, genetic variants are thought to predispose individuals to the disease. Several recent genome-wide association studies have identified a number of loci that increase sALS susceptibility, but these only explain a small proportion of the disease. To extend the current genetic evidence and to identify novel candidates of sALS, we performed a pooling genome-wide association study by 859,311 autosomal single-nucleotide polymorphisms of IlluminaHumanOmniZhongHua-8 combining pathway analysis in 250 typical sALS cases precluding age, clinical course, and phenotype interference and 250 control subjects from Chinese Han populations (CHP). The results revealed that 8 novel loci of 1p34.3, 3p21.1, 3p22.2, 10p15.2, 22q12.1, 3q13.11, 11q25, 12q24.33, and 5 previously reported loci of CNTN4 (kgp11325216), ATXN1 (kgp8327591), C9orf72 (kgp6016770), ITPR2 (kgp3041552), and SOD1 (kgp10760302) were associated with sALS from CHP. Furthermore, the pathway analysis based on the Gene Set Analysis Toolkit V2 showed that 10 top pathways were strongly associated with sALS from CHP, and among them, the 7 most potentially candidate pathways were phosphatidylinositol signaling system, Wnt signaling pathway, axon guidance, MAPK signaling pathway, neurotrophin signaling pathway, arachidonic acid metabolism, and T-cell receptor signaling pathway, a total of 39 significantly associate genes in 7 candidate pathways was suggested to involve in the pathogenesis of sALS from CHP. In conclusion, our results revealed several new loci and pathways related to sALS from CHP and extend the association evidence for partial loci, genes, and pathways, which were previously identified in other populations. Thus, our data provided new clues for exploring the pathogenesis of sALS.

P2X2/3 receptor activity of rat nodose ganglion neurons contributing to myocardial ischemic nociceptive signaling

Myocardial ischemia causes the production of a variety of chemical substances, which act on the cardiac afferent nerve to cause pain. Myocardial damage can affect cardiac vagal afferent activity. Survivors of myocardial infarction are often left with impaired activity of cardiac vagal sensory fibres. The nodose ganglia (NG) are lower ganglia of cardiac vagus nerve, which are chiefly visceral afferent in the sensation of heart. ATP as a possible damage signal may activate nociceptive sensory neurons. Activation of P2X(3), P2X(2/3) receptors by endogenous ATP contributes to the development of hyperalgesia. The present results have shown that the sensitivity of P2X(2/3) receptor in nodose ganglion neurons was increased after myocardial ischemic injury under electrophysiological observation. The inhibitive role of P2X(2/3) antagonist A-317491 on ATP-activated currents in myocardial ischemic rats was significantly increased, compared with that in control group at the same concentration of A-317491. The staining of P2X(2) and P2X(3) receptors in myocardial ischemic injury group appeared to be more intense than those in naive rats and myocardial ischemic rats treated with A-317491 with immunofluorescence double labeling methods. Therefore, the activity of P2X(2/3) receptors in NG neurons was involved in the transmission of myocardial ischemic nociceptive signal.

A Pooling Genome-Wide Association Study Combining a Pathway Analysis for Typical Sporadic Parkinson's Disease in the Han Population of Chinese Mainland.

Genome-wide association studies (GWAS) on sporadic Parkinson’s disease (sPD) are mainly conducted in European and American populations at present, and the Han populations of Chinese mainland (HPCM) almost have not been studied yet. Here, we conducted a pooling GWAS combining a pathway analysis with 862,198 autosomal single nucleotide polymorphisms of IlluminaHumanOmniZhongHua-8 in 250 sPD and 250 controls from HPCM precluded toxicant exposure, age, and heavy coffee drinking habit interference. We revealed that among the 22 potential loci implicated, PRDM2/KIAA1026 (kgp8090149), TSG1/MANEA (kgp154172), PDE10A (kgp8130520), MDGA2 (rs9323124), ATPBD4/LOC100288892 (kgp11333367), ZFP64/TSHZ2 (kgp4156164), PAQR3/ARD1B (kgp9482779), FLJ23172/FNDC3B (kgp760898), C18orf1 (kgp348599), FLJ43860/NCRNA00051 (kgp4105983), CYP1B1/C2orf58 (kgp11353523), WNT9A/LOC728728 (rs849898), ANXA1/LOC100130911 (rs10746953), FLJ35379/LOC100132423 (kgp9550589), PLEKHN1 (kgp7172368), DMRT2/SMARCA2 (kgp10769919), ZNF396/INO80C (rs1362858), C3orf67/LOC339902 (rs6783485), LOC285194/IGSF11 (rs1879553), FGF10/MRPS30 (rs13153459), BARX1/PTPDC1 (kgp6542803), and COL5 A2 (rs11186), the peak significance was at the kgp4105983 of FLJ43860 gene in chromosome 8, the first top strongest associated locus with sPD was PRDM2 (kgp8090149) in chromosome 1, and the 24 pathways including 100 significantly associated genes were strongly associated with sPD from HPCM. The 40 genes were shared by at least two pathways. The most possible associated pathways with sPD were axon guidance, ECM-receptor interaction, neuroactive ligand-receptor interaction, tight junction, focal adhesion, gap junction, long-term depression, drug metabolism-cytochrome P450, adherens junction, endocytosis, and protein digestion and absorption. Our results indicated that these loci, pathways, and their related genes might be involved in the pathogenesis of sPD from HPCM and provided some novel evidences for further searching the genetic pathogenesis of sPD.

Sterol regulatory element binding protein 1 and its target gene networks: Sterol regulatory element binding protein 1 and its target gene networks

Sterol regulatory element binding protein 1 (SREBP-1) is one of the important nuclear transcription factors. SREBP-1 can maintain lipids dynamic equilibrium by regulating the expression of enzymes required for synthesis of endogenous cholesterol, fatty acids, triglycerides and phospholipids. Anomalies of SREBP-1 and its target genes can cause a series of metabolic diseases such as insulin resistance, type Ⅱ diabetes, heart dysfunction, vascular complications and hepatic steatosis. In these years, the development of high-throughput technologies has greatly expanded our knowledge about SREBP-1 target genes and the pattern of transcriptional regulation. Here we reviewed recent research progress of SREBP-1, with a focus on the protein structure, activation process, DNA binding sites and target genes. Most importantly, we showed the transcriptional regulatory networks based on omics datasets, which will contribute to a better understanding of the role of SREBP-1 in lipid metabolism and provide new clues for the treatment of lipid metabolism disorders.

Gene2DGE: a Perl package for gene model renewal with digital gene expression data.

For transcriptome analysis, it is critical to precisely define all the transcripts across the whole genome. More and more digital gene expression (DGE) scannings have indicated the presence of huge amount of novel transcripts in addition to the known gene models. However, almost all these studies still depend crucially on existing annotation. Here, we present Gene2DGE, a Perl software package for gene model renewal with DGE data. We applied Gene2DGE to the mouse blastomere transcriptome, and defined 98,532 read-enriched regions (RERs) by read clustering supported by more than four reads for each base pair. Taking advantage of this ab initio method, we refined 2,104 exonic regions (4% of a total of 48,501 annotated transcribed regions) with remarkable extension into un-annotated regions (>50 bp). For 5% of uniquely mapped reads falling within intron regions, we identified 13,291 additional possible exons. As a result, we renewed 4,788 gene models, which account for 39% of a total of 12,277 transcribed genes. Furthermore, we identified 12,613 intergenic RERs, suggesting the possible presence of novel genes outside the existing gene models. In this study, therefore, we have developed a suitable tool for renewal of known gene models by ab initio prediction in transcriptome dissection. The Gene2DGE package is freely available at http://bighapmap.big.ac.cn/.