Dataset Information

Single cell RNA sequencing of the limb myotendionous junction

ABSTRACT: Vertebrate muscles and tendons are derived from distinct embryonic origins yet they must interact in order to facilitate muscle contraction and body movements. How robust muscle tendon junctions (MTJs) form to be able to withstand contraction forces is still not understood. Using techniques at a single cell resolution we reexamined the classical view of distinct identities for the tissues composing the musculoskeletal system. We identified fibroblasts that have switched on a myogenic program and demonstrate these dual identity cells fuse into the developing muscle fibers along the MTJs facilitating the introduction of fibroblast-specific transcripts into the elongating myofibers. We suggest this mechanism resulting in a hybrid muscle fiber, primarily along the fiber tips, enables a smooth transition from muscle fiber characteristics towards tendon features essential for forming robust MTJs. We propose that dual characteristics of junctional cells could be a common mechanism for generating stable interactions between tissues throughout the musculoskeletal system.

ORGANISM(S): Mus musculus

PROVIDER: GSE168153 | GEO | 2021/03/04

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Skeletal muscle atrophy is a consequence of many diseases, environmental insults, inactivity, age and injury. Atrophy is characterized by active degradation and removal of contractile proteins and a reduction in fiber size. Animal models have been extensively used to identify pathways leading to atrophic conditions. Here we have used genome-wide expression profiling analysis and quantitative PCR to identify the molecular changes that occur in two clinically relevant animal mouse models of muscle atrophy, hindlimb casting and Achilles tendon laceration (tenotomy). Gastrocnemius muscle samples were collected 2, 7 and 14 days after insult. The total amount of muscle loss as measured by wet weight and muscle fiber size was equivalent between models, although tenotomy resulted in a more rapid induction of muscle atrophy. Furthermore, tentomy resulted in the regulation of significantly more mRNA transcripts then casting. Analysis of the regulated genes and pathways suggest that the mechanism of atrophy is distinct between these models. The degradation following casting appears ubiquitin-proteasome-mediated while degradation following tenotomy appears lysosomal and matrix-metalloproteinase (MMP)-mediated. This data suggests that there are multiple mechanisms leading to muscle atrophy and that specific therapeutic agents may be necessary to combat the atrophy seen under different conditions. Muscle atrophy was induced through two methods; unloading induced by tendon laceration (Tenotomy) and immobilization induced by hindlimb casting (Casting). For the tenotomy, eight week old male C57/B6 mice were anesthetized by ether inhalation and subsequent intramuscular injection of ketamine-xylazine (0.1 ml/g). The right Achilles tendon just proximal to the calcaneus was severed with a sterile scalpel. The mice were allowed to recover and move freely about their cage. An additional cohort of animals was sham operated (Sham) which involved isolation and manipulation of the Achilles tendon without laceration. For the casting, the right hindlimbs of eight week old male C57Bl/6 mice were immobilized through casting. After 2, 7 or 14 days, animals were sacrificed and the left and right gastrocnemius muscles were carefully removed, flash frozen in liquid nitrogen, and stored at -80°C for further processing. The left untreated legs served as controls. A group of naïve animals that received no treatment or manipulation was included as an additional control. Each group consisted of between 5 and 10 samples for a total of 111 individual samples.

Dataset Information

Single cell RNA sequencing of the limb myotendionous junction

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure