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:We have undertaken a screen of mouse limb tendon cells in order to identify molecular pathways involved in tendon development. Mouse limb tendon cells were isolated based on Scleraxis (Scx) expression at different stages of development: E11.5, E12.5 and E14.5 Microarray comparisons were carried out between tendon progenitor and differentiated stages. Forelimbs from E11.5, E12.5 and E14.5 Scx-GFP embryos were collected and dissociated with trypsin to obtain cell suspensions. Scx-positive tendon cells were isolated by FACS. RNA was extracted and Fragmented biotin-labelled cRNA samples were hybridized on Affymetrix Gene Chip Mouse Genome 430 2.0 arrays.
Project description:We report RNA sequencing data from the plantaris tendons of adult male mice in the C57Bl/6 background that either have the IGF1 receptor (IGF1R) present in their tendons (Scx:IGF1R+) or mice in which IGF1R has been deleted in tenocytes expressing scleraxis (Scx:IGF1R-). Mice were created by crossing ScxCreERT2 mice with IGF1R flox/flox mice. Mice were treated with tamoxifen for 5 days to induce recombination at the IGF1R allele, and then subjected to a synergist ablation procedure in which the Achilles tendon is removed, resulting in compensatory growth of the plantaris tendon. Mice were analyzed either 7 or 14 days after synergist ablation. Control mice that did not undergo tamoxifen treatment or synergist ablation were also studied.
Project description:Despite their important roles in the musculoskeletal system, tendon and ligaments are much less studied comparing to bone, cartilage and muscle. The lack of knowledge in tendon biology severely hinders the understanding of the etiologies of tendon related diseases and development of efficient clinical treatments. In mouse, Scx gene, encoding a Twist family bHLH transcription factor, is expressed in progenitors of all tendons and ligaments, as well as in mature tenocytes. Previous studies show that inactivation of Scx gene results in absence or severe hypoplastia of force transmitting tendons, with muscle anchoring tendons and ligaments are less affected. Here we report a set of ChIPseq data from E13.5 forelimbs of novel Scx-2xFlag tagged mice in which a Scx-Flag fusion protein is expressed recapitulating endogenous Scx expression, and a set of RNAseq data of Scx-GFP positive cells from E13.5 Scx wildtype, E15.5 Scx wildtype and homozygous mutant forelimbs. Using RNAseq and ChIPseq assays, we identify several genes exhibiting Scx-dependent tendon expression druing differentiation, with Scx binding peaks located within their promoter/enhancer regions. Thus these genes may play critical roles in mediating Scx regulated tendon cell differentiation. Our results provide new insights in the mechanisms of tendon development.
Project description:We report RNA sequencing data from the plantaris tendons of adult male mice in the C57Bl/6 background that either have the scleraxis gene (Scx+) or mice in which scleraxis has been deleted using CreERT2 driven from the Rosa26 locus (Scx-). Mice in which scleraxis was deleted were created by crossing scleraxis-floxed mice with Rosa26-CreERT2 mice. Rosa26-CreERT2 mice that did not have a floxed scleraxis allele served as controls. Mice were treated with tamoxifen for 5 days to induce recombination at the scleraxis locus, and then subjected to a synergist ablation procedure in which the Achilles tendon is removed, resulting in compensatory growth of the plantaris tendon. Mice were analyzed either 7 or 14 days after synergist ablation. Control mice that did not undergo tamoxifen treatment or synergist ablation were also studied (NOC).
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.