Project description:Partial tendon-to-bone interface (TBI) injuries heal in a mechanically inferior manner and redevelop healthy uninjured tissue morphology. The origin of the cells involved in tendon-to-bone healing remains unknown. We employed a rigorous approach to evaluate if mouse skeletal stem cells (mSSC) play a role in tendon-to-bone healing after partial-injury. Using fluorescence-activated cell sorting we identified that found that they are present within the TBI. Using a TBI-injury rainbow lineage tracing mouse model, we demonstrated that injury-responsive cells within the TBI and calcaneus proliferate polyclonally following partial-tendon injury at the TBI. These injury-responsive clonal cells express skeletal marker SP7. We quantified the differences in mSCC frequency after TBI-injury and found that mSSC respond to injury with a higher frequency and have associated changes in gene expression, with the specific down-regulation of the TGFβ signaling pathway. Exogenous delivery of TGFβ after injury was found to reduce the mSSC response after injury. These findings suggest that mSSC may facilitate tendon-to-bone healing by downregulating TGFβ signaling within the mSSC niche.
Project description:scRNA and snATAC sequencing of cells harvested from the tendon injury site after a severe burn/tenotomy injury in Hoxa11 lineage traced mice allowed for differentation tracing of MSCs located in zeugopod after severe heterotopic ossification inducing injury. The use of immobilization also allowed us to determine the effects of limb immoblization on MSCs during aberrant wound healing.
Project description:Injury was induced in the left Achilles tendon by needle puncture. Rats were sacrificed 4 and 21 days post injury. Shams, in which the tendon was isolated but not punctured, were included as controls. Serum was collected post-mortem and RNAseq used to identify differentially expressed ncRNAs.
Project description:Little is understood about the roles of tendon cells during flexor tendon healing. To better understand tendon cell functions, the Scx-Cre mouse was crossed to the DTR mouse model to facilitate scleraxis lineage cell depletion prior to acute flexor tendon injury and repair. WT (cre-) and experimental (cre+) mice underwent complete transection and repair of the flexor digitorum longus tendon. Repaired tendons were harvested at 14 and 28 days post-repair for bulk RNA-Seq analysis to examine possible mechanisms driving differential healing due to Scx lineage cell depletion.
Project description:The rat tendon injury models were established and divided into three groups: normal control group, injury model group, and celecoxib + lactoferrin treatment group. Then, RNA sequencing and differential expression analysis were performed for samples from injury model group and celecoxib + lactoferrin treatment group on day 14. Next, autophagy/hypoxia/ferroptosis/pyroptosis-related genes retrieved from the corresponding databases and related literatures were downloaded to obtain the genes associated with autophagy/hypoxia/ferroptosis/pyroptosis. Subsequently, functional annotation, protein-protein interaction (PPI) network and transcriptional regulatory network construction for these genes were performed.
Project description:Self-renewal of tendons is rare since the vascular formation inside is extremely poor, thus reconstructive surgery using autologous tendons has been often taken place in the case of severe injury. However, the rate of re-injury after surgery is relatively high, and collection of autologous tendons leads muscle weakness which results in prolonged rehabilitation. Here, we introduce the induced pluripotent stem cells (iPSCs)-based technology aiming at developing a new therapeutic option after tendon injury. Firstly, we derived tenocytes from human iPSCs by recapitulating the normal progression of step-wise narrowing fate decisions in the vertebrate embryo. We used single-cell RNA sequencing to analyze the developmental trajectory of iPSCs-derived tenocytes. We then demonstrated that grafting iPSCs-tenocytes contributed to recovery of motor function after Achilles tendon injury in rat via engraftments and paracrine effects. The biomechanical strength of regenerated tendons recovered comparable to that of healthy tendons. We propose that the iPSCs-tenocytes will provide a novel therapeutic option in tendon injury.
Project description:We investigated calcaneal tendon extracellular matrix (ECM) remodeling after gastrocnemius muscle injury using a rat model. Wistar rats were randomly divided into four groups: control group (C; animals that were not exposed to muscle injury) and harvested at different time points post gastrocnemius muscle injury (3, 14 and 28 days) for gene expression analysis. qRT-PCR was performed using TaqMan Universal PCR Master Mix system (Applied Biosystems, CA, USA - Cat. 4304437).
Project description:We report the newly derived tendon like tissues from human iPSC. We depositted RNA sequencing data of human iPSC and derived MSC from human iPSC. We use these cells as materials to generae tenon-like tissues.
Project description:Intralesional mesenchymal stem cell (MSC) therapy has improved tissue architecture and reinjury rates in equine tendon injury; however, the mechanisms by which they promote repair are still being investigated. Therefore, the objectives of this study were to determine how the predominate pro-inflammatory cytokines present in a surgically induced model of equine tendon injury modulate MSC gene and protein expression.