Project description:To investigate the mechanism of electrical stimulation in the repair of spinal cord injury, we established a rat model of spinal cord injury. Then, we used RNA-SEQ data obtained from ES treatment and 6 different rat models of spinal cord injury for gene expression profile analysis.
Project description:Background: Niemann-Pick disease type A (NPDA), a disease caused by mutations in acid sphingomyelinase (ASM), involves severe neurodegeneration and early death. Intracellular lipid accumulation and plasma membrane alterations are implicated in the pathology. ASM is also linked to the mechanism of plasma membrane repair, so we investigated the impact of ASM deficiency in skeletal muscle, a tissue that undergoes frequent cycles of injury and repair in vivo. Methods: Utilizing the NPDA/B mouse model ASM−/− and wild type (WT) littermates, we performed excitation- contraction coupling/Ca2+ mobilization and sarcolemma injury/repair assays with isolated flexor digitorum brevis fibers, proteomic analyses with quadriceps femoris, flexor digitorum brevis, and tibialis posterior muscle and in vivo tests of the contractile force (maximal isometric torque) of the quadriceps femoris muscle before and after eccentric contraction-induced muscle injury. Results: ASM−/− flexor digitorum brevis fibers showed impaired excitation-contraction coupling compared to WT, a defect expressed as reduced tetanic [Ca2+]i in response to electrical stimulation and early failure in sustaining [Ca2+]i during repeated tetanic contractions. When injured mechanically by needle passage, ASM−/− flexor digitorum brevis fibers showed susceptibility to injury similar to WT, but a reduced ability to reseal the sarcolemma. Proteomic analyses revealed changes in a small group of skeletal muscle proteins as a consequence of ASM deficiency, with downregulation of calsequestrin occurring in the three different muscles analyzed. In vivo, the loss in maximal isometric torque of WT quadriceps femoris was similar immediately after and 2 min after injury. The loss in ASM−/− mice immediately after injury was similar to WT, but was markedly larger at 2 min after injury. Conclusions: Skeletal muscle fibers from ASM−/− mice have an impairment in intracellular Ca2+ handling that results in reduced Ca2+ mobilization and a more rapid decline in peak Ca2+ transients during repeated contraction-relaxation cycles. Isolated fibers show reduced ability to repair damage to the sarcolemma, and this is associated with an exaggerated deficit in force during recovery from an in vivo eccentric contraction- induced muscle injury. Our findings uncover the possibility that skeletal muscle functional defects may play a role in the pathology of NPDA/B disease.
Project description:Schwann cell (Büngner) repair cells play a critical role in orchestrating nerve repair after injury, but the reprogramming process that generates them is poorly understood. We present the first combined whole genome coding and non-coding RNA and CpG methylation study after nerve injury. We show that genes involved in epithelial to mesenchymal transition are enriched in repair cells and we identify long non-coding RNAs in Schwann cells. We demonstrate that the AP-1 transcription factor c-Jun regulates the expression of certain micro RNAs in repair cells, in particular miR-21 and miR-34. Surprisingly, changes in CpG methylation are limited in injury, unlike development, and restricted to specific locations, such as enhancer regions of novel Schwann cell specific genes, such as Nedd4l, and near to local enrichment of AP-1 motifs. These epigenetic changes significantly broaden our understanding of Schwann cell reprogramming in peripheral nervous system tissue repair. To identify epigenetic regulators underlying successful nerve regeneration we generated RNA-Seq, small-RNA-Seq and whole genome bisulfite sequencing libraries for uninjured nerve versus three and/or seven day post nerve transection sciatic nerves of adult C57BL/6J mice crush.
Project description:The extracellular niche is a key regulator of tissue morphogenesis and repair, however, its composition is currently not well characterized. Quantitative mass spectrometry resolved the dynamics of 8366 proteins from total tissue and bronchioalveolar lavage fluid in the consecutive phases of repair upon bleomycin induced lung injury. Joint analysis of proteome and transcriptome revealed posttranscriptional events during tissue remodeling. We developed a quantitative detergent solubility profiling method (QDSP), which enabled comprehensive characterization of the extracellular matrix and its interactions with secreted proteins, and showed the drastically altered association of morphogens, such as basement membrane netrins, to the insoluble matrix upon injury. We discovered several ECM proteins, including Emilin-2 and Collagen-XXVIII, as constituents of the provisional repair matrix. Our space and time resolved proteomics identified a host of tissue repair factor candidates with potential to promote the early events of progenitor cell mobilization or late events of repair pathways including the resolution of fibrosis.
Project description:To better understand the pathogenesis of AKI-to-CKD transition and specifically the mechanism of kidney atrophy, we compared the kidney response to an identical time of ischemic injury between mice subjected to unilateral ischemia/reperfusion (U-IRI) to induce atrophy and those subjected to unilateral IRI with contralateral nephrectomy (IRI/CL-NX) to induce adaptive repair. We performed single cell RNA-sequencing (scRNA-seq) analyses on day 14 after injury to identify major cell types in the kidney and the differential transcriptional response between the models in each cell type.
Project description:Lactoferrin (LF) is an iron-binding multifunctional cationic glycoprotein secreted by exocrine glands and neutrophils in mammals. In this study, we created a mouse model of lipopolysaccharide (LPS)-induced acute lung injury and explored the anti-inflammatory effect and mechanism of bovine lactoferrin (bLF) in acute lung injury using the RNA sequencing (RNA-seq) technology and transcriptome analysis.