Project description:Here we compare the gene expression profiles of two distict, fluorescently identified neuronal populations, the motor neruons (MN) and the decending commissural interneurons (dCIN) of the neonatal rat spinal cord isolated with laser microdissection. These two populations participate in the neuronal networks in the spinal cord where they have destinct functions in shaping (dCINs) and transferring the output to the muscles (MNs) during locomotion. We wished to determine how the functinal differences in these nerurons are manifested at the gene expression level. Keywords: Cell type comparison.
Project description:Summary: Spinal cord injury (SCI) is a damage to the spinal cord induced by trauma or disease resulting in a loss of mobility or feeling. SCI is characterized by a primary mechanical injury followed by a secondary injury in which several molecular events are altered in the spinal cord often resulting in loss of neuronal function. Analysis of the areas directly (spinal cord) and indirectly (raphe and sensorimotor cortex) affected by injury will help understanding mechanisms of SCI. Hypothesis: Areas of the brain primarily affected by spinal cord injury are the Raphe and the Sensorimotor cortex thus gene expression profiling these two areas might contribute understanding the mechanisms of spinal cord injury. Specific Aim: The project aims at finding significantly altered genes in the Raphe and Sensorimotor cortex following an induced moderate spinal cord injury in T9.
Project description:Here we compare the gene expression profiles of two distict, fluorescently identified neuronal populations, the motor neruons (MN) and the decending commissural interneurons (dCIN) of the neonatal rat spinal cord isolated with laser microdissection. These two populations participate in the neuronal networks in the spinal cord where they have destinct functions in shaping (dCINs) and transferring the output to the muscles (MNs) during locomotion. We wished to determine how the functinal differences in these nerurons are manifested at the gene expression level. Experiment Overall Design: Neurons were retrogradely labelled with rhodamine through application of the tracer to cut axons followed by incubation in oxygenated Ringer solution. Spinal cord were then snap frozen, cryosectioned and fluorescent single cells were laser dissected into a collector tube to a total of ca. 50-200 cells pr sample. RNA was then extracted, two round amplified and hybridized to Affymatrix RNU-34 chips. 22 samples were hybridized onto chips, 7 MNs, 7 CINS and 8 MIX.
Project description:Neonatal spinal cord tissues exhibit remarkable regenerative capabilities compared to adult tissues following injury. Although some cellular signaling pathways involved in the process have been identified, the specific role of extracellular matrix (ECM) responsible for neonatal spinal cord regeneration has remained elusive. Here we revealed that early developmental spinal cord contained a higher abundance of ECM proteins associated with neural development and axon growth but fewer inhibitory proteoglycans compared to adult spinal cord. Decellularized spinal cord ECM from neonatal (DNSCM) and adult (DASCM) rabbits preserve the major difference of native spinal cord tissues in both stages. Compared to DASCM, DNSCM promoted proliferation, migration, and neuronal differentiation of neural progenitor cells (NPCs), as well as facilitated the long-distance axonal outgrowth and axon regeneration of spinal cord organoids. Pleiotrophin (PTN) and Tenascin (TNC) in DNSCM were identified as contributors to the remarkable neural regeneration ability. Furthermore, DNSCM demonstrated superior performance when used as a delivery vehicle for NPCs and organoids in rats with spinal cord injury (SCI). It suggests that ECM cues derived from different development stage might contribute to the distinct regeneration ability of spinal cord.
Project description:Knee osteoarthritis (KOA), as a degenerative multifactorial disease, affects the quality of life and mental health of patients, and also brings a huge socioeconomic burden. Treating synovitis have shown promise as anti-inflammatory therapeutics in mitigating OA symptoms and disease progression. Here, by analysing synovial single-cell sequencing (scRNA-seq) data from KOA, we found that synovial fibroblasts (FLS) in OA synovium showed a distinct pro-inflammatory phenotype. We collected synovial tissue from patients with clinical OA as well as from healthy donors, and histological examination was consistent with findings in scRNA-seq. Inspired by recent cross-tissue fibroblast lineage studies, we identified by sequencing that healthy FLS in synovial tissues share transcriptome-level similarities with dermal fibroblasts (DFb). Subsequently, we revealed the local as well as systemic distribution of intra-articular injected DFbs by constructing/extracting two types of rat fibroblasts (luciferase DFbs as well as GFP DFbs). The results demonstrate that DFbs can be locally retained in the synovium for up to three weeks following targeted engrafting on it. And intra-articular injection does not result in DFbs migration to vital organs or the occurrence of histological changes in these organs. A rat model of KOA was constructed by anterior cruciate ligament transection (ACLT) in order to study the therapeutic effect of DFbs on KOA. After injection, the rats showed improvement in painful gait. In addition, histological as well as imaging results showed reduced synovitis and improvement in articular cartilage. Finally we verified the protective effect of DFbs on cytokine-stimulated chondrocytes in a co-culture system.