A murine model of large-scale bone regeneration reveals a selective requirement for Sonic Hedgehog.

Building and maintaining skeletal tissue requires the activity of skeletal stem and progenitor cells (SSPCs). Following injury, local pools of these SSPCs become active and coordinate to build new cartilage and bone tissues. While recent studies have identified specific markers for these SSPCs, how they become activated in different injury contexts is not well-understood.

Identification of the skeletal progenitor cells forming osteophytes in osteoarthritis.

Objectives: Osteophytes are highly prevalent in osteoarthritis (OA) and are associated with pain and functional disability. These pathological outgrowths of cartilage and bone typically form at the junction of articular cartilage, periosteum and synovium. The aim of this study was to identify the cells forming osteophytes in OA.

Skeletal stem cells: insights into maintaining and regenerating the skeleton.

Skeletal stem cells (SSCs) generate the progenitors needed for growth, maintenance and repair of the skeleton. Historically, SSCs have been defined as bone marrow-derived cells with inconsistent characteristics. However, recent tracking experiments have revealed the presence of SSCs not only within the bone marrow but also within the periosteum and growth plate reserve zone.

Sox9+ messenger cells orchestrate large-scale skeletal regeneration in the mammalian rib.

Unlabelled: Most bones in mammals display a limited capacity for natural large-scale repair. The ribs are a notable exception, yet the source of their remarkable regenerative ability remains unknown. Here, we identify a -expressing periosteal subpopulation that orchestrates large-scale regeneration of murine rib bones.

The use of commercially available adhesive tapes to preserve cartilage and bone tissue integrity during cryosectioning.

The use of fluorescent tags to monitor protein expression and to lineage-trace cells has become a standard complement to standard histological techniques in the fields of embryology, pathology and regenerative medicine. Unfortunately, traditional paraffin embedding protocols can substantially diminish or abolish the native emission signal of the fluorophore of interest. To preserve the fluorescent signal, an alternative is to use cryosectioning; however, this can often result in undesirable artefacts such as tearing or shattering - particularly for mineralized tissues such as bone and cartilage.

Increased redox-sensitive green fluorescent protein reduction potential in the endoplasmic reticulum following glutathione-mediated dimerization.

As the endoplasmic reticulum (ER) is the compartment where disulfide bridges in secreted and cell surface proteins are formed, the disturbance of its redox state has profound consequences, yet regulation of ER redox potential remains poorly understood. To monitor the ER redox state in live cells, several fluorescence-based sensors have been developed. However, these sensors have yielded results that are inconsistent with each other and with earlier non-fluorescence-based studies.