Gene expression signatures following nerve injury in a rat model (0d-14d)
ABSTRACT: We used microarrays to distinguish the gene expression differences among different time points after injury. We generated L4-6 dorsal root ganglia (DRG) tissues and proximal sciatic nerve (SN) tissues (0.5cm) at 0d, 1d, 4d, 7d and 14d after sciatic nerve resection.
Project description:We used microarrays to distinguish the gene expression differences among different time points after injury. We generated proximal sciatic nerve (SN) tissues (0.5cm) at 0h, 0.5h, 1h, 3h, 6h and 9h after sciatic nerve resection.
Project description:We applied Solexa sequencing technology to identify rat microRNA genes in proximal sciatic nerve following sciatic nerve resection. Using Solexa sequencing, computational analysis and Q-PCR verification, 93 novel miRNAs in rats were discovered and identified, of which 42 novel miRNAs were first reported in proximal sciatic nerve of rat and 51 novel miRNAs were produced at days 1, 4, 7 and 14 after sciatic nerve resection. These data provide an important resource relating to the role and regulation of miRNAs for future studies relating to peripheral nerve injury and regeneration. Keywords: Small RNA sequencing 18-30 nt small RNAs from proximal sciatic nerve of 30 Thirty Sprague-Dawley (SD) rats were sequenced at one Solexa lane
Project description:We used microarrays to distinguish the gene expression differences among different time points after injury We generated L4-6 dorsal root ganglia (DRG) tissues (0.5cm) at 0.5h, 3h, 6h and 9h after sciatic nerve resection
Project description:We applied Solexa sequencing technology to identify rat microRNA genes in dorsal root ganglia (DRGs) following sciatic nerve resection. Using Solexa sequencing, computational analysis and Q-PCR verification, 114 novel miRNAs in rats were discovered and identified, of which 52 novel miRNAs were first reported in rat DRGs and 62 novel miRNAs were produced at days 1, 4, 7 and 14 after sciatic nerve resection. These data provide an important resource relating to the role and regulation of miRNAs for future studies relating to peripheral nerve injury and regeneration. 18-30 nt small RNAs from 30 Thirty Sprague-Dawley (SD) rats were sequenced at one Solexa lane
Project description:ChIP-seq of H3K4me3 in rat peripheral nerve was used to identify transcription start sites associated with Schwann cell-expressed genes. The analysis was performed in injured and control nerve to identify injury-responsive changes in Schwann cells. H3K4me3 ChIP samples were prepared from rat sciatic nerve at 1 day post-transection using both the distal stump of the injured nerve and the contralateral (sham) nerve.
Project description:An insulating myelin sheath ensures saltatory conduction of mechanosensory A afferents. Myelin damage results in the electrical instability of A fibers and the ability to generate pain in response to light touch/pressure (mechanical allodynia). We have hypothesized and then established that the release of T cell epitopes of myelin basic protein (MBP) enables nociceptive circuitry in myelinated fibers. Thus, mass spectrometry analysis of the rat sciatic nerve proteome followed by bioinformatics examination of the datasets revealed a loss of MBP and activation of T-helper cell signaling in the nerves undergoing chronic constriction injury (CCI). Matrix metalloproteinase-9 (MMP-9) proteolysis resulted in the MBP digest peptides, including the MBP84-104 and MBP68-86 regions, which exhibit prominent immunogenic epitopes. Myelin-forming Schwann cells and paranodal areas accumulated MHCII, MMP-9 and the degraded MBP at the sciatic nerve injury site. Administration of the immunodominant MBP84-104 and MBP68-86 peptides but not of the control peptides in a naïve rat sciatic nerve produced robust mechanical allodynia. Allodynia was accompanied by the T cell infiltration and an increase in MHCII, IL-17A and TNF- levels at the nerve injection site and the segmental ganglia. The pro-nociceptive activity of the synthetic MBP84-104 diminished in athymic nude rats lacking T cells. SB-3CT, an antagonist of MMP-9, inhibited mechanical allodynia, neuroinflammation and spinal sensitization after CCI. Collectively, our novel data implicate, for the first time, MMP-mediated cleavage of MBP and the resulting MBP digest fragments as a major cause of neuropathic pain. Gene extression profiling of total RNAs extracted from rat sciatic nerves, dorsal root ganglion and spinal cords after MBP84-104 peptide injection
Project description:Remyelination is a key step in functional nerve regeneration performed by Schwann cells (SC). We have demonstrated that matrix metalloproteinase (MMP)-9 is a major regulator of signal transduction and phenotypic switching in SCs. Herein, genome-wide transcriptional profiling, followed by Ingenuity Pathway Analysis revealed the MMP-9 signaling network and its endogenous inhibitor, TIMP-1, among the top induced genes of the injured sciatic nerve, that co-distributed with MMP-9 in myelinating SCs and the paranodal/nodal areas of myelinated fibers. Homo- and heterodimers of the active and proMMP-9 were purified from injured nerves using gelatin-sepharose. MMP-9 gene deletion increased the number of immature, GFAP+ mSC and post-mitotic cell counts that correlate with shorter myelin internodes in remyelinated fibers lacking MMP-9. MMP-9 is essential to nodal clustering of voltage-gated Na+ (Nav) channels. MMP inhibitor therapy diminished the expression of Nav 1.7 and 1.8. These data established the essential role of MMP-9 in guiding SC differentiation toward myelin production and in molecular assembly of the myelin domains. Modification of Nav channels in myelinated fibers may thus provide an important therapeutic approach for a number of facilitates regeneration and attenuated neuropathic pain. Gene expression profiling of total RNAs extracted from murine sciatic nerves, dorsal root ganglion and spinal cords at day 1 and day 5 post injury.
Project description:To further development of our gene expression approach to biodosimetry, we have employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential to distinguish radiation dose across an exposure range relevant for medical decision-making in a radiological emergency. Human peripheral blood from healthy donors was irradiated ex vivo, and a 74-gene consensus signature was identified that distinguished between four radiation doses (0.5, 2, 5 and 8 Gy) and control samples. The same set of genes separated samples by exposure level at both six and 24 hours after treatment, with overlap evident only at the highest two doses (5 and 8 Gy). Expression of five genes (CDKN1A, FDXR, SESN1, BBC3 and PHPT1) from this signature was quantified in the same RNA samples by real-time PCR, confirming low variability between donors as well as the predicted radiation response pattern. Heat and shake stress induced gene expression in rat jejunum was measured with or without 3 days stressed (Control and S3d groups) The conditions of the treatment for rats were as follows: 35°C with a vibration of 0.1 × g for 3 days， 2 h/day in a temperature shake. each group had 3 sample replications, and each sample were mixed by 3 rats total RNA