Project description:We performed RNASeq and confocal imaging analysis to characterize the gene expression changes in the cornea after wounding that modulate sensory axon integrity. We show that by preserving the ability of axons to attach to one another and to corneal epithelial cells, mitomycin C enhances sensory nerve recovery after mechanical injury.
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:In this study, a quantitative proteomic technique based on isobaric tags for relative and absolute quantitation (iTRAQ) was used to compare the proteome of cultured sensory and motor nerve fibroblasts (Fbs). Among a total of 2597 overlapping proteins identified, we obtained 148 differentially expressed proteins, of which 116 proteins were significantly higher expressed in sensory Fbs, and 32 proteins were significantly higher expressed in motor Fbs. Western blot and qPCR analysis were applied to validate differentially expressed proteins. Functional categorization indicated that differentially expressed proteins were linked to a diverse array of biological processes , including regeneration, axon guidance, cytoskeleton organization, cell proliferation, cell migration, cell adhesion, and tissue remodeling, which might play a critical role in the specificity of peripheral nerve regeneration. Furthermore, following co-culture of motor neurons with motor or sensory Fbs , motor Fbs significantly enhanced neurite growth than sensory Fbs. These findings indicated that nerve Fbs expressed the distinct motor and sensory phenotypes involved in different patterns of protein expression, biological processes, and effects on neurons.
Project description:We performed the RNA-seq analysis to unravel the underlying mechanism of corneal nerve regeneration after treatment with our identified RvD6 isomer and RvD6 standard.
Project description:The cornea is the most innervated tissue in the human body. Myelinated axons upon inserting into the peripheral corneal stroma lose their myelin sheaths and continue into the central cornea wrapped by only nonmyelinating corneal SCs (nm-cSCs). This anatomical organization is believed to be important for central vision. Here we employed single-cell RNA sequencing (scRNA-seq), microscopy, and transgenics to characterize these nm-cSCs of the central cornea. Using principal component analysis, uniform manifold approximation and projection, and unsupervised hierarchal cell clustering of scRNA-seq data derived from central corneal cells of male rabbits, we successfully identified several clusters representing different corneal cell types, including a unique cell cluster representing nm-cSCs. To confirm protein expression of cSC genes, we performed cross-species validation, employing corneal whole mount immunostaining with confocal microscopy in mouse corneas. We expect that our results will advance the future study of nm-cSCs in applications of nerve repair, and provide a resource for the study of corneal sensory function.
Project description:We reported the gene expression analysis of different types of sensory neuron with peripheral nerve transection treatment on single cell level. We found substantial variation between myelinated large diameter neurons and small diameter nonpeptidergic nociceptors, in both terms of regeneration response genes regulation as well as fraction of cells respond to nerve injury.
Project description:Neurotrophic Keratopathy (NK),classified as an orphan disease (ORPHA137596), is a rare degenerative corneal disease characterized by epithelial instability and decreased corneal sensitivity caused by the damage to the corneal nerves. The administration of human recombinant nerve growth factor (rhNGF) eye drops, as a licensed-in-Europe specific medication for treatment of moderate and severe NK, has added promising perspectives to the management of this disorder by providing a valid alternative to the neurotization surgery. However, few studies have been conducted to the molecular mechanism underlying the response to the treatment. Here, we carried out tears proteomics to highlight the protein expression during pharmacological treatment of NK. Our data emphasized a proteome modulation duringrhNGF treatment related to an increase in DNA synthesis, an activation ofboth BDNF signaland IL6 receptor.Furthermore, the amount of neuronal Extracellular Vesicles EVs (CD171+)correlated with the EVs carrying IL6R (CD126+) togetherassociated to the inflammatory EVs (CD45+) in tears. Such scenario determined drug response, confirmed by an in vivo confocal microscopy analysis, showing an increase in length, density and number of nerve fiber branches during treatment. In summary, rhNGF treatment seems to determine an inflammatory micro-environment, mediated by functionalized EVs, defining the drug response by stimulating protein synthesis and fiber regeneration.
Project description:The miR-183/96/182 cluster (miR-183C) is specifically expressed in sensory neurons and immune cells and modulates corneal immune/inflammatory response to bacterial infection. To uncover the roles of miR-183C in corneal homeostasis through its regulation of sensory neurons of the trigeminal ganglia (TG) and innate myeloid cells, we created miR-183C conventional knockout (KO), and sensory nerve-specific (SNS-CKO) and myeloid cell-specific conditional knockout (MS-CKO) mice. We performed 3'RNA sequencing in the TG and corneas of these knockout mice and their wild type (WT)-control littermates. To study specific functions of miR-183C in corneal resident myeloid cells (CRMCs), we isolated Csf1r-EGFP+ CRMCs from conventional KO and MS-CKO and their WT control mice. By comparison of the gene expression profiles of the KO or CKO vs their corresponding WT mice, we identified a series of differentially expressed genes. Bioinformatic analyses uncovered tissue- and/or cell-type-specific target genes of miR-183C. Functional annotation of the target genes revealed functions of miR-183C in TG and CRMCs.
Project description:The goal of this study was to analyze global gene expression in FACS purified Nav1.8 lineage sensory neurons, which include nociceptor neurons that detect damaging/noxious stimuli, following peripheral inflammation by intraplantar injection of Complete Freund's Adjuvant (CFA) or Sciatic Nerve Injury (SNI) by nerve transection. Nav1.8 Trangsgenic TdTomato+ neurons were purified from Lumbar L4-L6 dorsal root ganglia (DRG) by flow cytometry from mice on the ipsilateral or contralateral sides, following Complete Freund's Adjuvant injection (day 1) or sciatic nerve transection (day 5). Neurons were then analyzed for transcriptional gene expression by microarray analysis.