Project description:Mechanical overload in the heart induces pathological remodeling that typcially leads to heart failure. We sought to build an in vitro model of heart failure by applying cyclic stretch to engineered isotropic (iso) and anisotropic (aniso) NRVM tissues. We used micoarrays to determine the effects of longitudinal and transvserse cyclic stretch on gene expression in engineered NRVM cardiac tissues. We found that cyclic stretch induced up-regulation of several known indicators of heart faliure, independent of the direction of stretch. NRVMs were seeded on silicone membranes coated with isotropic (iso) fibronectin (FN) or micropatterned with FN (aniso), cultured statically for 1h (t=0h), and stretched for increasing amount of time (t=6h, 24h, 96h) before RNA extraction and hybridization on Affymetrix microarrays. For aniso tissues, stretch was applied in either the longitudinal (long) or transverse (trans) direction. RNA was collected over six primary NRVM harvests and thus RNA was also extracted and analyzed from samples seeded for 1h (at t=0h) on iso FN to be used to normalize across cell harvests.
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.