Fast, non-eccentrically loaded exercise worsens tendinopathic healing responses in a murine model.

Objective: To advance the understanding of how alterations in exercise speed and grade (flat vs 17° incline or decline) affect the quality of tendon healing, and to determine if a biomarker relationship exists between serum levels of a ColX breakdown product (CXM) and animals exposed to treadmill running protocols.

Animals: 35 male mice (C57BL/6J), 8 weeks of age.

Procedures: Mice were preconditioned on a treadmill for 14 days.

Corrigendum: Gene therapy approaches for equine osteoarthritis.

[This corrects the article DOI: 10.3389/fvets.2022.

Gene therapy approaches for equine osteoarthritis.

With an intrinsically low ability for self-repair, articular cartilage injuries often progress to cartilage loss and joint degeneration resulting in osteoarthritis (OA). Osteoarthritis and the associated articular cartilage changes can be debilitating, resulting in lameness and functional disability both in human and equine patients. While articular cartilage damage plays a central role in the pathogenesis of OA, the contribution of other joint tissues to the pathogenesis of OA has increasingly been recognized thus prompting a whole organ approach for therapeutic strategies.

Surface topography as a tool to detect early changes in a posttraumatic equine model of osteoarthritis.

The equine model of posttraumatic osteoarthritis (OA) mimics certain aspects of the naturally occurring disease, both in horses and humans. The objective of this study was to assess articular cartilage degeneration in a posttraumatic OA model using the established macroscopic and microscopic scoring systems and compare them with a novel surface topography analysis. OA was induced in the carpal joint of 15 (n = 15) mixed breed horses.

Effect of Skeletal Paracrine Signals on the Proliferation of Interzone Cells.

Objective: Articular cartilage in mammals has limited intrinsic capacity to repair structural defects, a fact that contributes to the chronic and progressive nature of osteoarthritis. In contrast, Mexican axolotl salamanders have demonstrated the remarkable ability to spontaneously and completely repair large joint cartilage lesions, a healing process that involves interzone cells in the intraarticular space. Furthermore, interzone tissue transplanted into skeletal defects in the axolotl salamander demonstrates a multi-differentiation potential.

Chondrogenic differentiation potential of adult and fetal equine cell types.

Objective: To determine the chondrogenic potential of cells derived from interzone tissue, the normal progenitor of articular cartilage during fetal development, compared to that of adult bone marrow-derived and adipose-derived mesenchymal cell isolates. The objective of this study was to compare the chondrogenic potential of fetal musculoskeletal progenitor cells to adult cell types, which are currently used therapeutically to facilitate joint cartilage repair in equine clinical practice. The hypothesis tested was that cells derived from interzone tissue have a chondrogenic potential that exceeds that of adult bone marrow-derived and adipose-derived mesenchymal cell isolates.

Changes in the appendicular skeleton during metamorphosis in the axolotl salamander (Ambystoma mexicanum).

Axolotl salamanders (Ambystoma mexicanum) remain aquatic in their natural state, during which biomechanical forces on their diarthrodial limb joints are likely reduced relative to salamanders living on land. However, even as sexually mature adults, these amphibians can be induced to metamorphose into a weight-bearing terrestrial stage by environmental stress or the exogenous administration of thyroxine hormone. In some respects, this aquatic to terrestrial transition of axolotl salamanders through metamorphosis may model developmental and changing biomechanical skeletal forces in mammals during the prenatal to postnatal transition at birth and in the early postnatal period.

Pathological effects of processed bovine pericardial scaffolds--a comparative in vivo evaluation.

The objective of the present study was to assess the biocompatibility and regenerative potential of decellularized bovine pericardial scaffold in comparison with glutaraldehyde-treated and fresh bovine pericardial implants using short-term intramuscular implantation testing in a rat model. The inflammatory and immune responses were assessed using histopathological examination, special stains for connective tissue, histomorphometric evaluation, and immunohistochemistry. The decellularized pericardium showed an active tissue remodeling response with complete cellular invasion, minimum connective tissue encapsulation, extensive fibrovascular tissue formation, and collagen deposition.