Project description:To shed light on the early processes of immune response to peripheral nerve injury, we first used genome-wide transcriptional profiling and bioinformatics (Ingenuity, NextBio) pathway analyses of the proximal (P; regenerating) and distal (D; degenerating) nerve stumps at day 1 in the sciatic nerve axotomy model in rats. We identified a number of specific immunomodulatory genes and pathways that were regulated shortly post-injury in both the P and D segments, including all members of the interleukin (IL), chemokine, tumor necrosis factor (TNF), matrix metalloproteinase (MMP), toll-like receptor (TLR), tissue inhibitor of metalloproteinase (TIMP), ion channel and myosin families. Immunomodulatory calcium-binding S100A8 and S100A9 were the top up-regulated genes in both the D and P segments. In cultured Schwann cells stimulated with the purified S100A8/A9 heterodimer we recorded a high level of similarity of the activated genes and pathways with that of the injured nerve, especially in the activation of the chemokine and cytokine gene networks that support agranulocyte and granulocyte chemotaxis, adhesion, transmigration and rolling signaling pathways. We also confirmed activation of multiple cell death related gene networks supporting TNFR1, natural killer cell receptor and death receptor apoptosis signaling in the D stump, and the gluconeogenesis/glycolysis and cytoskeletal motility signaling in the P stump, corroborated by activation of ERK, PI3K and JNK kinase pathways. As compared to the D segment, multiple additional pathways were more efficiently upregulated in the P stump, including the IL-6 and -17, MMP-9, calcium, activated agranulocyte, leukocyte rolling and glutathione-mediated detoxification signaling pathways. These data suggest that shortly after nerve injury, upregulation of S100A8/A9 is responsible for the expression and release of chemokines and cytokines by Schwann cells, necessary to generate the initial chemotactic gradient and guide the hematogenous immune cells into the injury site. Gene expression profiling of total RNAs extracted from injured and non-injured rat sciatic nerves, and primary rat Schwann cells stimulated with S100A8/A9 proteins
Project description:Tumor-associated macrophages enhance the malignant phenotypes of esophageal squamous cell carcinoma (ESCC) cells. We have previously identified several factors associated with ESCC progression using an indirect co-culture assay between ESCC cells and macrophages. Here, we newly established a direct co-culture assay between ESCC cells and macrophages which is closer to the actual cancer microenvironment than an indirect co-culture assay. To investigate the gene expression changes by co-culture with macrophages, we performed cDNA microarray analysis between mono-cultured and co-cultured ESCC cells with macrophages. We found that the expression of S100 calcium binding protein A8 and A9 (S100A8 and S100A9) was enhanced in co-cultured ESCC cells with macrophages. S100A8 and S100A9 commonly exist stable and function as a heterodimer (S100A8/A9). S100A8/A9 is widely known as an inflammation marker. It also contributes to the enhancement of malignant phenotypes in several cancers. S100A8/A9 enhances the migration and invasion of ESCC cells by activating Akt and p38 MAPK signaling pathways. The higher expression levels of S100A8/A9 were associated with poor prognosis in ESCC patients. These results suggest that S100A8/A9 contributes to the progression of ESCC.
Project description:To shed light on the early processes of immune response to peripheral nerve injury, we first used genome-wide transcriptional profiling and bioinformatics (Ingenuity, NextBio) pathway analyses of the proximal (P; regenerating) and distal (D; degenerating) nerve stumps at day 1 in the sciatic nerve axotomy model in rats. We identified a number of specific immunomodulatory genes and pathways that were regulated shortly post-injury in both the P and D segments, including all members of the interleukin (IL), chemokine, tumor necrosis factor (TNF), matrix metalloproteinase (MMP), toll-like receptor (TLR), tissue inhibitor of metalloproteinase (TIMP), ion channel and myosin families. Immunomodulatory calcium-binding S100A8 and S100A9 were the top up-regulated genes in both the D and P segments. In cultured Schwann cells stimulated with the purified S100A8/A9 heterodimer we recorded a high level of similarity of the activated genes and pathways with that of the injured nerve, especially in the activation of the chemokine and cytokine gene networks that support agranulocyte and granulocyte chemotaxis, adhesion, transmigration and rolling signaling pathways. We also confirmed activation of multiple cell death related gene networks supporting TNFR1, natural killer cell receptor and death receptor apoptosis signaling in the D stump, and the gluconeogenesis/glycolysis and cytoskeletal motility signaling in the P stump, corroborated by activation of ERK, PI3K and JNK kinase pathways. As compared to the D segment, multiple additional pathways were more efficiently upregulated in the P stump, including the IL-6 and -17, MMP-9, calcium, activated agranulocyte, leukocyte rolling and glutathione-mediated detoxification signaling pathways. These data suggest that shortly after nerve injury, upregulation of S100A8/A9 is responsible for the expression and release of chemokines and cytokines by Schwann cells, necessary to generate the initial chemotactic gradient and guide the hematogenous immune cells into the injury site.
Project description:The pathophysiology of traumatic brain injury (TBI) requires further characterization to fully elucidate changes in molecular pathways. Cerebrospinal fluid (CSF) provides a rich repository of brain-associated proteins that may be affected by TBI. Here, we implemented high-resolution mass spectrometry to evaluate changes to the CSF proteome after severe TBI. 91 CSF samples were analyzed with mass spectrometry, collected from 16 patients with severe TBI (mean 32 yrs; 81% male) on day 0, 1, 2, 4, 7 and/or 10 post-injury (8-16 samples/timepoint) and compared to CSF obtained from 11 non-injured controls. We quantified 1152 proteins with mass spectrometry, of which approximately 80% were associated with CSF. 1083 proteins were differentially regulated after TBI compared to control samples. The most highly-upregulated proteins at each timepoint included neutrophil elastase, myeloperoxidase, cathepsin G, matrix metalloproteinase-8, and S100 calcium-binding proteins A8, A9 and A12—all proteins involved in neutrophil activation, recruitment, and degranulation. Pathway enrichment analysis confirmed the robust upregulation of proteins associated with innate immune responses. Conversely, downregulated pathways included those involved in nervous system development, and several proteins not previously identified after TBI such as testican-1 and latrophilin-1. We also identified 7 proteins (GM2A, Calsyntenin 1, FAT2, GANAB, Lumican, NPTX1, SFRP2) positively associated with an unfavorable outcome at 6 months post-injury. These findings highlight the robust innate immune response that occurs after severe TBI, supporting future studies to target neutrophil-related processes. In addition, the novel proteins we identified to be differentially regulated by severe TBI warrant further investigation as potential biomarkers or therapeutic targets.
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:Peripheral nerve repair and functional recovery depend on the rate of nerve regeneration and the quality of target reinnervation. It is important to fully understand the cellular and molecular basis underlying the specificity of peripheral nerve regeneration, which means the achieving of respective correct pathfinding and accurate target reinnervation for regrowing motor and sensory axons. In this study, a quantitative proteomic technique, based on isobaric tags for relative and absolute quantitation (iTRAQ) was used to profile the protein expression pattern between single motor and sensory nerves at 14 days after peripheral nerve transection. Among a total of 1259 proteins identified, 176 proteins showed the differential expressions between injured motor and sensory nerves. Quantitative real-time RT-PCR and Western blot analysis were applied to validate the proteomic data on representative differentially expressed proteins. Functional categorization indicated that differentially expressed proteins were linked to a diverse array of molecular functions, including axonogenesis, response to axon injury, tissue remodeling, axon ensheathment, cell proliferation and adhesion, vesicle-mediated transport, response to oxidative stress, internal signal cascade, and macromolecular complex assembly, which might play an essential role in peripheral motor and sensory nerve regeneration. Overall, we hope that the proteomic database obtained in this study could serve as a solid foundation for the comprehensive investigation of differentially expressed proteins between injured motor and sensory nerves and for the mechanism elucidation of the specificity of peripheral nerve regeneration.
Project description:Proteomic analysis of injured human peripheral nerves, particularly focusing on events occurring in the proximal and distal nerve ends, remains relatively underexplored. This study aimed to investigate the molecular patterns underlying a digital nerve injury, concentrating on differences in protein expression between the proximal and distal nerve ends. A total of 26 human injured digital nerve samples (24 men; 2 women; median age 47 [30-66] years), harvested during primary nerve repair within 48 hours post-injury from proximal and distal nerve ends, were analyzed using mass spectrometry. A total of 3914 proteins were identified, with 127 proteins showing significant differences in abundance between the proximal and the distal nerve ends. The downregulation of proteins in the distal nerve end was associated with synaptic transmission, autophagy, neurotransmitter regulation, cell adhesion and migration. Conversely, proteins upregulated in the distal nerve end were implicated in cellular stress response, neuromuscular junction stability and muscle contraction, neuronal excitability and neurotransmitter release, synaptic vesicle recycling and axon guidance and angiogenesis. Investigation of proteins, with functional annotations analysis, in proximal and the distal ends of human injured digital nerves, revealed dynamic cellular responses aimed at promoting tissue degeneration and restoration, while suppressing non-essential processes.
Project description:Although genome-wide association studies, animal models, and cell culture systems have yielded important insights into the pathogenesis of neovascular age-related macular degeneration (nAMD), the underlying molecular pathways remain ill defined. Recent studies have deciphered the transcriptional profile of choroidal neovascularisation (CNV) of body donor eyes and were thus limited by the time span from death to preservation and the associated rapid 5'-RNA degradation. In this study, CNVs were therefore formalin-fixed immediately after surgical extraction from patients with nAMD and analyzed using a 3’ RNA sequencing approach called Massive Analysis of cDNA Ends (MACE). Age-matched formalin-fixed paraffin-embedded (FFPE) RPE-choroidal specimens obtained from the macular region of enucleated eyes with ciliary body melanoma served as controls. Transcriptome profiles were generated and disease-associated gene signatures were identified using statistical and bioinformatic methods. Calprotectin (S100A8/A9) protein expression was investigated by immunohistochemistry and ELISA.We identified 158 differentially-expressed genes (DEG) that were significantly increased in CNV compared to control tissue. Gene ontology enrichment analysis demonstrated that these DEG contributed to biological processes, such as Blood Vessel Development, Extracellular Structure Organization, Response to Wounding and several immune-related terms. The S100 calcium-binding protein A8 (S100A8) and S100A9 emerged among the top DEG, as confirmed by immunohistochemistry on CNV tissue and protein analysis of vitreous samples from nAMD patients and controls. This study provides a high-resolution RNA-sequencing-based transcriptional signature of choroidal neovascular membranes in AMD patients and reveals S100A8/A9 as a novel biomarker and promising target for AMD-directed therapeutics and diagnostics.