Project description:Expression profiling of L4 and L5 Dorsal Root Ganglion (DRG) in the spinal nerve ligation model of neuropathic pain. The goal of the study was to identify genes involved in neuropathic pain This series of samples comprises of contralateral and ipsilateral L4 and L5 DRG tissue collected 4 weeks after rats underwent a L5 spinal nerve ligation (SNL) or a sham operation with no L5 spinal nerve ligation. This defines 8 groups (i) contralateral L4 DRG from the sham cohort (n=5), (ii) ipsilateral L4 DRG from sham cohort (n=5), (iii) contralateral L4 DRG from SNL cohort (n=5), (iv) ipsilateral L4 DRG from the SNL chort (n=5), (v) contralateral L5 DRG from the sham cohort (n=5), (vi) ipsilateral L5 DRG from sham cohort (n=5), (vii) contralateral L5 DRG from SNL cohort (n=5), (viii) ipsilateral L5 DRG from the SNL cohort (n=5)
Project description:The study pursued dual goals: To advance mRNA-seq bioinformatics towards unbiased transcriptome capture and to demonstrate its potential for discovery in neuroscience by applying the approach to an in vivo model of neurological disease. We found that 12.4% of known genes were induced and 7% were suppressed in the dysfunctional (but anatomically intact) L4 dorsal root ganglion (DRG) 2 weeks after L5 spinal Nerve Ligation (SNL). A new algorithm for agnostic mapping of pre-mRNA splice junctions (SJ) achieved a precision of 97%. mRNA-seq of L4 DRG 2 weeks and 2 months after L5 spinal nerve ligation. CONTROL and SNL were used to identify differential gene expression between chronic pain and standard conditions in Rattus norvegicus. CONTROL and SNL and PILOT were used to perform 'agnostic splice site discovery' in the nervous system transcriptome in Rattus norvegicus
Project description:Two out-bred rat selection lines were separated to produce different hypersensitivity phenotypes following nerve injury. These lines were termed High Pain and Low Pain (HP or LP). Each sub-strain was either subject to a Sham surgery or a Spinal Nerve Ligation (SNL) surgery to the L4 and L5 spinal nerves. Three days following surgery L4/L5 Dorsal Root Ganglia (DRG) were dissected from these animals. For the rat line separation protocol see: Devor M, Raber P (1990) Heritability of symptoms in an experimental model of neuropathic pain. Pain 42:51-67. 12 Hybridizations, 3 per condition; Sham HP DRG; 3 day SNL HP DRG; Sham LP DRG; 3 day SNL LP DRG.
Project description:Purpose: Nerve injury-induced hyperactivity of primary sensory neurons in the dorsal root ganglion (DRG) contributes critically to chronic pain development, but its underlying mechanisms remain incompletely understood. Chronic neuropathic pain has a clear epigenetic component, however, most studies so far have focused on histone modifications. We determined changes of DNA methylation in the rat DRG, spinal cord, and prefrontal cortex after spinal nerve ligation (SNL).
Project description:Purpose: Nerve injury-induced hyperactivity of primary sensory neurons in the dorsal root ganglion (DRG) contributes critically to chronic pain development, but its underlying mechanisms remain incompletely understood. Chronic neuropathic pain has a clear epigenetic component, however, most studies so far have focused on histone modifications. We determined changes of DNA methylation in the rat DRG, spinal cord, and prefrontal cortex after spinal nerve ligation (SNL).
Project description:AIM: We performed RNA-sequencing experiments seeking genes whose expression changed due to nerve injury. In addition, we wanted to test whether inhibition of the methyl transferase G9a/GLP, that methylates H3K9me2, could reverse those expression changes due to nerve ligation. G9a/GLP methylase was pharmacologically inhibited using UNC0638. METHOD: We generated cDNA libraries from RNA purified from DRGs obtained from Sham operated (4), SNL (4), and SNL plus UNC0638 (3) rats. We sequenced the cDNA libraries generating single end 50 bp reads on the illumina HiSeq 2500 platform. Sequencing reads were aligned to the rat genome rn4 using TopHat RESULTS: We were able to map 16876 genes, from which 2035 changed their expression values at least two fold when we compared SNL to Sham operated (pâ?¤ 0.01). There were 1205 upregulated and 832 down-regulated genes. Next, we focused on genes whose expression was either up or down-regulated 2 fold due to nerve ligation, and the values would be normalized to control level after G9a/GLP inhibito (UNC0638)r treatment. We identified 639 genes in our data set that behave this way We generated cDNA libraries from RNA purified from DRGs obtained from Sham operated (4), SNL (4), and SNL plus UNC0638 (3) rats. We sequenced the cDNA libraries generating single end 50 bp reads on the illumina HiSeq 2500 platform. Sequencing reads were aligned to the rat genome rn4 using TopHat
Project description:Two out-bred rat selection lines were separated to produce different hypersensitivity phenotypes following nerve injury. These lines were termed High Pain and Low Pain (HP or LP). Each sub-strain was either subject to a Sham surgery or a Spinal Nerve Ligation (SNL) surgery to the L4 and L5 spinal nerves. Three days following surgery L4/L5 Dorsal Root Ganglia (DRG) were dissected from these animals. For the rat line separation protocol see: Devor M, Raber P (1990) Heritability of symptoms in an experimental model of neuropathic pain. Pain 42:51-67.
Project description:Neuroinflammatory and neuroimmune mechanisms, as exemplified by infiltrating immune cells and activation of resident endothelial/glial cells, respectively, are known to be involved in the establishment and maintenance of chronic pain. An immune system pathway that may be involved in the activation of both immune and glial cells is complement. The complement pathway is made up of a large number of distinct plasma proteins which react with one another to opsonize pathogens and induce a series of inflammatory responses to help fight infection. Cleaved products and complexes produced by complement activation are responsible for a range of effects including mediation of immune infiltration, activation of phagocytes, opsonization/lysis of pathogens and injured cells, and production of vasoactive amines such as histamine and serotonin. Gene-expression microarray-analysis was performed on the rat spinal nerve ligation (SNL) model of neuropathic pain Experiment Overall Design: For gene expression analysis, rats from five experimental groups were sacrificed 19â??21 days after surgery: (1)Naïve+ vehicle; (2) Naïve + GPN; (3) sham + vehicle; (4) SNL + vehicle; (5) SNL + GPN. Tissue was collected from whole brain, hemisected spinal cord, mid thigh sciatic nerve, and L4, L5 and L6 dorsal root ganglia (DRG), both ipsilateral(ipsi) and contralateral (contra) to the injury. In addition,â??â??organ recitalâ??â?? tissues were harvested from naı ¨ve animals: adrenal,aorta, fetal brain, kidney, liver, quadriceps muscle, spleen,submaxillary gland, and testis and 15 other tissues.For each experimental group and tissue, samples rapidly frozen on dry ice were separated into two pools(Pool 1 and Pool 2), consisting of half or 4-6 animals each.Pool 1 total RNA was subjected to standard methods on Affymetrix GeneChip Arrays using rat U34 A, B, and C.
Project description:AIM: We performed RNA-sequencing experiments seeking genes whose expression changed due to nerve injury. In addition, we wanted to test whether inhibition of the methyl transferase G9a/GLP, that methylates H3K9me2, could reverse those expression changes due to nerve ligation. G9a/GLP methylase was pharmacologically inhibited using UNC0638. METHOD: We generated cDNA libraries from RNA purified from DRGs obtained from Sham operated (4), SNL (4), and SNL plus UNC0638 (3) rats. We sequenced the cDNA libraries generating single end 50 bp reads on the illumina HiSeq 2500 platform. Sequencing reads were aligned to the rat genome rn4 using TopHat RESULTS: We were able to map 16876 genes, from which 2035 changed their expression values at least two fold when we compared SNL to Sham operated (p≤ 0.01). There were 1205 upregulated and 832 down-regulated genes. Next, we focused on genes whose expression was either up or down-regulated 2 fold due to nerve ligation, and the values would be normalized to control level after G9a/GLP inhibito (UNC0638)r treatment. We identified 639 genes in our data set that behave this way