RNA-seq of Wister Rat blood serum to investigate small non-coding RNAs in serum as biomarkers of tendon injury
Ontology highlight
ABSTRACT: 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:Peripheral afferent neurons terminate at the surfaces of tendons, yet their role after injury beyond nociceptive functions remain unclear. Using transgenic animal models, sensory neurons were found to sprout after Achilles tendon injury in domains of Nerve growth factor (NGF) expression. Conditional deletion of Ngf in either myeloid or mesenchymal cell types led to tendon repair defects – findings phenocopied by inactivation of TrkA (Tropomyosin receptor kinase A) using a knockin mouse model. We sought to identify the signals modulated with neural TrkA inhibition. A combination of single cell and spatial transcriptomic analysis was performed on the Achilles injury site of TrkAF592A animals and compared them to TrkAWT.
Project description:Peripheral afferent neurons terminate at the surfaces of tendons, yet their role after injury beyond nociceptive functions remain unclear. Using transgenic animal models, sensory neurons were found to sprout after Achilles tendon injury in domains of Nerve growth factor (NGF) expression. Conditional deletion of Ngf in either myeloid or mesenchymal cell types led to tendon repair defects – findings phenocopied by inactivation of TrkA (Tropomyosin receptor kinase A) using a knockin mouse model. We sought to identify the signals modulated with neural TrkA inhibition. A combination of single cell and spatial transcriptomic analysis was performed on the Achilles injury site of TrkA^F592A animals and compared them to TrkA^WT.
Project description:Achilles tendinopathy is often thought to be a consequence of overuse of the Cells within the Achilles tendon of healthy rats undergo a series of changes following physiologic levels of mechanical stimulation after running, and we further explored the transcriptome changes in Achilles tendon cells during post-exercise recovery. Our current experiment reveals RNA-seq analysis of the transcriptome of the rat Achilles tendon after 12 hours of rest following running.
Project description:The Achilles tendon is the thickest tendon in the human body, and Achilles tendinopathy is its most prevalent disorder, often considered a consequence of overuse. While disruption to the collagen fibers represents a significant manifestation of Achilles tendinopathy, strikingly little is known about the mechanisms by which healthy tendon accumulates damage in vivo.As existing studies of tendon biomechanics and mechanobiology predominantly relied on in vitro or ex vivo experiments on isolated tissues, it is still largely unknown whether and how disruptions occur to the collagen molecules in healthy Achilles tendons following physiological activities. We reported the first RNA-seq analysis reflecting transcriptome changes in healthy rat Achilles tendons following running, providing a resource for future investigations in tendon mechanobiology and sports medicine.
Project description:Our study reveals up-regulation of the TAK1 pathway when compared with the uninjured hindlimb in our model of trauma-induced heterotopic ossification (tHO) consisting of hindlimb Achilles’ tendon transection with dorsal burn injury.
Project description:Healing process after connective tissues (CT) injury is complex but important as CT are critical for human moving, and patient outcome of CT injured patients is protracted with high individual variation. Specific markers which could be used for healing prognosis will be great help to monitor patient outcome, and furtherly improve target treatment and patient recovery. Although several common factors like age, gender and body mass index (BMI) were reported to predict ATR healing outcome [references], more specific markers which can be used as predictors of patient outcome after ATR are still lacking. Several biomarkers have been reported to associate with tendon healing, and indicated their relationship with patient outcome(1-4). These results highlight the potential of protein expression detection and analysis for tendon study in general and healing outcome prognosis in particular. Collagen type I (Col1a1) is the main component of Achilles tendon and plays vital role in tendon healing via involving in collagen fibrils production among tendon fibroblasts(5). Higher production of Col1a1 is associated with faster tendon repair(6), previous study on animal model reported the increased Col1a1 synthesis can exert a positive effect on tendon healing[?]. Thus, functional proteins with high impact on Col1a1 can be used not only to improve tendon healing, also can be as targets for healing improvement and outcome prediction. The proteome file of Achilles tendon which is important to increase understanding of tendon healing and help to identify accurate outcome-related biomarkers is however lagged behind. The identification of proteomic profile of Achilles tendon is very much limited in number of proteins and sample size(7-9), and is even few on human. Recent improvement in proteomic assay based on mass spectrometry (MS) made it possible to assemble the proteomic landscape of human tissues(10, 11) with high quality and sensitivity. To characterize the proteomic components in human Achilles tendon, we utilized biopsies from ATR patients with both good and poor 1-year healing outcome. A validated platform including quantitative MS and clinical database was used to identify proteomic landscape and potential bio-predictors of clinical outcome. Our study may provide a more comprehensive landscape of proteins for human Achilles tendon, as well as specific biomarkers which can be used for long term outcome prognosis after ATR.
Project description:To investigate which mRNA and miRNA are involved in Dicer KO mouse tendon hypoplasticity, we performed RNA-seq and small RNA-seq using RNA from Achilles tendon of Cont (Dicer f/f), Scx HT (ScxCre/+ Knock In:Dicer +/+) and Dicer KO (ScxCre/+ Knock In:Dicer f/f) mice at 4 weeks of age. Achilles tendon from 4-week-old female mice was harvested, RNA was isolated using an RNA extraction kit. RNA libraries were generated and sequenced by K. K. DNAFORM (Tokyo, Japan). The libraries were sequenced by Illumina HISEQ4000 using Illumina provided protocol. Differential gene expression was analyzed with R Bioconductor DESeq2. We found that a large portion of tendon-fibroblast characteristic genes was downregulated in Dicer KO mice Achilles tendon compared to Cont and Scx HT.
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:Tendon is a highly aligned connective tissue, in which the macro-structure consists of collagen-rich fascicles surrounded by interfascicular matrix (IFM). In a series of recent studies in equine tissue, we have demonstrated specialisation of tendon composition, structure and mechanics to achieve the tendon’s functional requirements, specifically reporting extensive specialisation of the IFM region in the energy storing superficial digital flexor tendon. We have also demonstrated loss of functional specialisms with ageing, leading to a hypothesised new paradigm for tendinopathy, focused on the importance of the IFM. However, to date, there have been no studies focused on structure-function specialisation or the IFM in functionally distinct human tendons. Here, we compare the positional anterior tibialis tendon and energy storing Achilles tendon, performing a detailed analysis of the composition and mechanical properties of both fascicle and IFM regions, to test the hypothesis that the IFM in the energy storing Achilles tendon has specialised composition and mechanical properties, and that these specialisations are lost with ageing. We demonstrate that the IFM is specialised in the energy storing Achilles tendon, with greater elasticity and fatigue resistance than in the positional anterior tibialis tendon. While there were few age-related alterations in mechanics, we did identify age-related alterations in the IFM proteome of the Achilles tendon specifically, which is predicted to be regulated by TGF-beta signalling and may be responsible for the trend towards decreased fatigue resistance observed in the Achilles IFM with ageing.
Project description:We have compared the gene expression profile of rat Achilles tendon-derived stem cells in post-natal tendon development. Rat tendon stem/progenitor cells (TSPCs) were isolated at different stages of post-natal development: TSPCs-1d, TSPCs-7d and TSPCs-56d.